US006096692A United States Patent (19) 11 Patent Number: 6,096,692 Hagihara et al. (45) Date of Patent: Aug. 1, 2000

54 SYNTHETIC LUBRICATING OIL 4,851,144 7/1989 McGraw et al.. 5,395,544 3/1995 Hagihara et al...... 252/68 75 Inventors: Toshiya Hagihara, Izumisano; Shoji 5,523,010 6/1996 Sorensen et al...... 508/307 Nakagawa, Wakayama; Yuichiro 5,575,944 11/1996 Sawada et al.. Kobayashi, Wakayama; Hiroyasu 5,720,895 2/1998 Nakagawa et al...... 252/68 Togashi, Wakayama; Koji Taira, FOREIGN PATENT DOCUMENTS Wakayama; Akimitsu Sakai, Wakayama, all of Japan 0696564. 2/1996 European Pat. Off.. 2003067 8/1970 Germany. 73 Assignee: Kao Corporation, Tokyo, Japan 59-25892 2/1984 Japan. 4320498 11/1992 Japan. 21 Appl. No.: 08/776,751 657243 3/1994 Japan. 22 PCT Filed: Feb. 27, 1995 OTHER PUBLICATIONS 86 PCT No.: PCT/JP95/00304 Chemical Abstracts, vol. 77, No. 9, Abstract No. 61237u (XP-002097541), Jun. 29, 1990. S371 Date: Feb. 13, 1996 Primary Examiner Jacqueline V. Howard S 102(e) Date: Feb. 13, 1996 Attorney, Agent, or Firm-Birch, Stewart, Kolasch & Birch, LLP 87 PCT Pub. No.: WO96/06839 57 ABSTRACT PCT Pub. Date: Mar. 7, 1996 The present invention relates to a Synthetic lubricating oil 30 Foreign Application Priority Data comprising cyclic ketals or cyclic acetals obtained by a Aug. 29, 1994 JP Japan ...... 6-228616 reaction between one or more polyhydric alcohols having an Oct. 31, 1994 JP Japan ...... 6-292431 even number of hydroxyl groups of not less than 4 and not more than 10 and one or more Specific carbonyl compounds, 51) Int. Cl." ...... C10M 105/18; CO7D 317/18 or one or more ketals or acetals which are reactive deriva 52 U.S. Cl...... 508/307; 549/372; 252/68 tives of Said carbonyl compounds, a working fluid compo 58 Field of Search ...... 508/307; 252/67, Sition for a refrigerating machine comprising a hydrofluo 252/68; 549/372 rocarbon and a refrigeration oil containing the cyclic ketals or cyclic acetals; and novel compounds of the above cyclic 56) References Cited acetals and a production method thereof. The present inven U.S. PATENT DOCUMENTS tion provides a Synthetic lubricating oil which shows a good thermal Stability, a good oxidation resistance, no carboxylic 1,934,309 11/1933 Hoover ...... 549/372 acid formation due to hydrolysis and a low hygroscopicity 3,714.202 1/1973 Nakaguchi et al. . ... 549/372 and is inexpensive as well. Also, a working fluid composi 3,725,438 4/1973 Barone et al...... 549/372 tion for a refrigerating machine which shows a good insu

3,741,986 6/1973 Hartmann ...... 549/372 3,900,411 8/1975 Andress, Jr...... 508/307 lating property, favorable hygroscopicity, and no carboxylic 3,910,845 10/1975 Coon ...... 508/307 acid formation due to hydrolysis as well as being inexpen 4,076,727 2/1978 Zey et al...... 252/68 Sive can be provided. 4,659,809 4/1987 Matsumura. 4,755,316 7/1988 Magid et al.. 7 Claims, No Drawings 6,096,692 1 2 SYNTHETIC LUBRICATING OL romethane (HFC32), and pentafluoroethane (HFC125), have been developed as substitutes for CFC12 or HCFC22. This application is a 371 of PCT/JP95/00304 filed Feb. However, since the polarity of hydrofluorocarbons is 27, 1995. higher than that of CFC12 or HCFC22, the use of conven tional lubricating oils, Such as naphthene mineral oils, TECHNICAL FIELD poly-C-olefins and alkylbenzenes, causes two-phase Separa The present invention relates to a Synthetic lubricating oil tion of the working fluid at low temperatures. This is due to using, as a base oil, cyclic ketals or cyclic acetals having a poor compatibility between the conventional lubricating oils particular structure, and also to a working fluid composition and the hydrofluorocarbons. Two-phase Separation hampers for a refrigerating machine which uses the Synthetic lubri oil return, which in turn interferes with heat transfer due to cating oil. deposition of a thick oil film around the condenser and evaporator used as heat eXchangers. It can also cause Sig The present invention further relates to cyclic acetals nificant failures, Such as poor lubrication and foaming upon which are useful as polar oils, organic Solvents, lubricants, Starting operation. Therefore, the conventional refrigeration Synthetic lubricating oils, or refrigeration oils, or as inter 15 oils cannot be used as refrigeration oils under these new mediates in the production of Surfactants, organic Solvents, refrigerant atmospheres. With this being the Situation, lubri polar oils, Synthetic lubricating oils, refrigeration oils, etc., cating oils with good compatibility with hydrofluorocarbons and to a method for producing the cyclic acetals. have been Sought. BACKGROUND ART As for lubricity, CFC12 and HCFC22 generate hydrogen chloride upon its partial decomposition. The hydrogen chlo With lengthened intervals of oil changes, need of energy ride thus formed reacts with the friction Surface to form a Saving, use of high performance machines, and down-sizing coating of chlorides, thereby improving the lubricity. On the of machines, demand for the performance of lubricating oils other hand, hydrofluorocarbons containing no chlorine has become Severe. In particular, lubricating oils with a high atoms are not expected to have Such an effect; therefore, the thermal Stability and a high oxidation resistivity have been 25 refrigeration oils used in combination with hydrofluorocar Strongly Sought. In the Situation where there has been bons are required to have a further excellent lubricity when increasing public concern about global environmental compared to the conventional refrigeration oils. pollution, Such as depletion of OZone layer caused by freon, In addition, the refrigeration oils used in combination the earth warming due to exceSS carbon dioxide and with hydrofluorocarbons have to have good thermal stability methane, destruction of forests by Sulfur dioxide and NO in in the presence of hydrofluorocarbons. exhaust fumes, and pollution of Soil and lakes due to Moreover, in the compression-type refrigerating chemical leakage, environmental protective measures have machines for electric refrigerators and air conditioners, Since been strongly sought also in the field of lubricating oils. organic materials are used for motor components Such as In order to meet the requirements for high thermal Sta insulators and enameled wires, the working fluid comprising bility and oxidation resistivity, ethers, Such as polyalkylene 35 a hydrofluorocarbon and a refrigeration oil is required to glycols, and esters, Such as aliphatic diesters and hindered have no adverse effects on the organic materials and also esters, have been developed and used for engine oils, have a good insulating property. hydraulic oils, grease base oils, gear oils, rolling oils, precision instrument oils, etc. AS refrigeration oils which can be used in combination 40 with hydrofluorocarbons Such as 1,1,1,2-tetrafluoroethane However, ethers, Such as polyalkylene glycols, have a (HFC134a), polyalkylene glycol compounds are disclosed in higher polarity than conventionally used mineral oils to U.S. Pat. No. 4,755,316 (Japanese Patent Unexamined cause the following drawbacks: (1) high hygroscopicity, and Application No. 2-502385), Japanese Patent Laid-Open No. (2) insolubility of additives which are conventionally used 3-14894 (European Patent No. 377122), and Japanese Patent for lubricating oils. An ether Synthesized from an alkyl 45 Laid-Open No. 2-182780 (WO90/05172). halide and a polyol, which has a lower polarity than poly Since polyalkylene glycol compounds have a higher alkylene glycols, is described in Japanese Patent Examined polarity than naphthene mineral oils, their compatibility Publication No. 1-29240. This ether also has a problem that with HFC 134a at low temperatures is certainly good. a trace of residual halogen in the ether product may impair However, polyalkylene glycol compounds have a problem to thermal stability and oxidation resistivity. 50 cause phase Separation as the temperature increases, as EsterS also are not free from drawbacks. That is, carboxy mentioned in U.S. Pat. No. 4,755,316. There are also several lic acid formed by hydrolysis of esters erodes metals, and other problems about polyalkylene glycol compounds. A esters tend to impair the effects of oilineSS improvers and poor insulating property is one of the problems. Due to this extreme pressure additives, though esters have a merit to Significant problem, polyalkylene glycol compounds cannot reduce friction because they are well adsorbed onto metals. 55 be used for refrigerating devices of electric refrigerators and Thus, Synthetic lubricating oils with adequately low air conditioners where a motor is incorporated in a com polarity, high thermal Stability, high oxidation resistivity, no preSSor. Therefore, applications of polyalkylene glycol com formation of carboxylic acids due to hydrolysis and low pounds are proposed for car air conditioners where their hygroscopicity are in high demand. poor insulating property does not cause any problems. High Recently, the use of dichlorodifluoromethane (CFC12) for 60 hygroscopicity is another significant problem of polyalky refrigerators and car air conditioners is restricted, and will be lene glycol compounds. Water absorbed by the compounds legally banned at the end of 1995 in order to protect the causes thermal instability in the presence of HFC134a and ozone layer from the viewpoint of the environment of the hydrolysis of organic materials. Such as PET films. Insulating earth, and also the use of chlorodifluoromethane (HCFC22) property can be improved and hygroscopicity is decreased for room air conditioners is about to be legally regulated. 65 by reducing the number of ether bonds per unit weight of Thus, hydrofluorocarbons which do not destroy the ozone polyalkylene glycol compounds, but the compatibility with layer, such as 1,1,1,2-tetrafluoroethane (HFC 134a), difluo hydrofluorocarbons becomes poor. Thus, ether compounds 6,096,692 3 4 like polyalkylene glycol compounds cannot have both good acetals for a working fluid composition for a refrigerating compatibility with hydrofluorocarbons and good insulating machine. In the former publication, it is disclosed that ketals property/decreased hygroscopicity at the same time. or acetals prepared from monohydric or dihydric alcohols In order to solve the above problems of polyalkylene and ketones or aldehydes are used in combination with a glycol compounds, Such as poor insulating property and Synthetic lubricating oil of ester or polyalkylene glycol type. high hygroscopicity, ester compounds and carbonate com In the latter publication, ester or carbonate derivatives of pounds have been developed. For example, the following glycerol, trimethylolethane, trimethylolpropane and compounds are disclosed as refrigeration oils which can be pentaerythritol, which have ketal or acetal groups in the used in combination with 1,1,1,2-tetrafluoroethane molecules, are disclosed. The acetals and ketals disclosed in (HFC134a): mixed oils of polyalkylene glycol compounds the former publication have drawbacks of Small molecular and ester oils are disclosed in U.S. Pat. No. 4,851,144 weight and low boiling and flashing points. The acetals and (corresponding to Japanese Patent Laid-Open No. ketals disclosed in the latter publication have drawbacks of 2-276894) and Japanese Patent Laid-Open No. 2-158693; high cost because their production has two or more reaction ester oils are disclosed in Japanese Patent Unexamined StepS. Some acetals or ketals in the latter publication also Application No. 3-505602 (WO90/12849) and Japanese 15 have a drawback of difficulty in producing them at high Patent Laid-Open Nos. 3-128991, 3-128992, 3-88892, and purity. Also, acetals and ketals disclosed in the latter pub 3-179091; and carbonate oils are disclosed in Japanese lication have 2 or more ether bonds in a molecule, resulting Patent Laid-Open Nos. 2-132178 and 3-149295, and Euro in unsatisfactory improvement of insulating property. pean Patent No. 421,298. The refrigerant-oil Systems developed So far have Some Ester compounds and carbonate compounds show good problems as mentioned above. The hydrofluorocarbon compatibility with hydrofluorocarbons and high thermal polyalkylene glycol oil system has problems in hygroscop Stability in the presence of hydrofluorocarbons. Also, these icity and insulating property; and the hydrofluorocarbon compounds have markedly better insulating properties and ester oil system and the hydrofluorocarbon-carbonate oil much lower hygroscopicity than polyalkylene glycol com System have problems of poor resistance against hydrolysis. pounds. However, compared with the conventional CFC12 25 Both of these Systems are unsatisfactory as a working fluid mineral oil working fluid System, both freon and oil tend to composition for a refrigerating machine, because they have have a high polarity in the hydrofluorocarbon-ester oil higher hygroscopicity as compared with the conventional System or hydrofluorocarbon-carbonate oil system, and the CFC12-mineral oil system and cause thermal instability, Systems become highly hygroscopic. Therefore, esters tend deterioration of organic materials, and corrosion and wear of to be hydrolyzed to form carboxylic acids, and the formed metals. Polyvinyl ether compounds show a molecular carboxylic acids may in turn erode metals and cause to wear weight distribution, and therefore partially contain mol down the metals. Also, in the case of using a carbonate oil, ecules with high molecular weights, which cause to lower there arises a problem that a non-condensable carbon diox the compatibility with hydrofluorocarbons. Polyvinyl ether ide gas is generated owing to hydrolysis of the carbonate oil compounds also have drawbacks of limited availability of to cause low refrigerating capacity. 35 the Starting materials and high cost. Ketals and acetals In particular, in the case of room air conditioners, it is reported So far have drawbacks of low molecular weight and common practice to fill an air conditioner with a refrigerant high cost. upon installation. Therefore, unlike refrigerating machines It is common practice to form cyclic acetals by using for which filling of refrigerant is carried out in a factory, it acetone as a ketone for the purpose of protection in the field is almost impossible to prevent a working fluid of room air 40 of Sugar and polyol Synthesis. Recently, 1,3-dioxolan Syn conditioners from being contaminated with water. thesized from formaldehyde and ethylene glycol is on the Therefore, there has been a concern about the reliability of market as an organic Solvent. the hydrofluoro carbon-e Ster oil System and As for cyclic acetals formed from sorbitol and hydrofluorocarbon-carbonate oil System, when these SyS 45 benzaldehyde, dibenzylideneSorbitol is known as a gelling tems are used in room air conditioners. agent. Also, cyclic acetals for med from an unsaturated WO93/24435 discloses a polyvinyl ether compound as a aldehyde and Sorbitol are utilized as a Starting material of polyether compound which is free from the problem of poor polymers. insulating property of polyalkylene glycols. This polyvinyl Also, cyclic acetals formed between Sorbitol and acetone, ether compound is prepared by polymerization of vinyl ether 50 formaldehyde, acetaldehyde, or butyraldehyde are known. monomers and Subsequent hydrogenation. It is described However, cyclic acetals having longer, linear or branched that the compound has a good compatibility with hydrof chains have not yet been known. Cyclic acetals formed luorocarbons and good insulating property. However, Since between Sorbitol and isobutyraldehyde are not known. the polyvinyl ether compound is Synthesized by Cyclic acetals are used as organic Solvents as mentioned polymerization, it shows molecular weight distribution. 55 above, as Solvents for ink and paint, as additives or gelling Therefore, a part of high molecular weight polymerS Some agents, as Starting materials for polymers, as absorbents for times causes plugged capillaries and worSens the compat absorption refrigerating machines (Japanese Patent Laid ibility of the compound with hydrofluorocarbon. Also, the Open No. 59-25892), or as dehydrating agents for refrig compound requires complicated post-treatment and cannot eration oils (Japanese Patent Laid-Open Nos. 4-320498 and always be obtained in a high yield because vinyl ether 60 6-57243). monomers, the Starting materials of the polyvinyl ether Cyclic ketals have been formed between hexahydric compound, are not stable Substances. In particular, the yield alcohols, Such as Sorbitol and mannitol, and acetone for the of those with low degree of polymerization (around 6) is purposes of protection of a compound and identification of low. Some Vinyl ether monomers of certainstructures cannot Structures. However, Such cyclic ketals have high melting be easily obtained, and are, therefore, very expensive. 65 points and can hardly be used as polar oils, Synthetic Alternatively, Japanese Patent Laid-Open Nos. 4-320498 lubricating oils and refrigeration oils which are required to and 6-57243 disclose the use of cyclic ketals and cyclic be in a liquid State around room temperature. Although 6,096,692 S cyclic ketals having unsaturated alkyl chains have lower melting points, they have drawbacks in Stability. Those (II) having aromatic ringS Such as a phenyl ring are to be R3 gelatinized, and therefore, unsuitable as polar oils, Synthetic C= O lubricating oils, and refrigeration oils. On the other hand, 5 R4 cyclic acetals formed from lower hydric alcohols, Such as ethylene glycol, have low Viscosity and, therefore, unsuit able for the use in Synthetic lubricating oils and refrigeration wherein R represents a hydrogen atom or a linear, branched, or cyclic alkyl group having 1-12 carbon atoms, oils. R" represents a linear, branched, or cyclic alkyl group having 1-12 carbon atoms; R and R' together may repre DISCLOSURE OF THE INVENTION Sent an alkylene group having 2-13 carbon atoms, a total Accordingly, it is an object of the present invention to carbon atoms of R and R' being 1-13, or one or more ketals or acetals, which are reactive deriva provide a Synthetic lubricating oil which is excellent in 15 thermal Stability and oxidation resistivity, free from car tives of Said carbonyl compounds. boxylic acids formation due to hydrolysis, low in (3) The synthetic lubricating oil as described in (1) or (2) hygroscopicity, and inexpensive; and to provide an inexpen above, wherein the polyhydric alcohols have no ether bond; Sive working fluid composition for a refrigerating machine (4) The synthetic lubricating oil as described in (1) or (2) which is free from formation of carboxylic acid and has above, wherein the polyhydric alcohols have one ether bond; good performance with respect to compatibility with (5) The synthetic lubricating oil as described in (3) or (4) hydrofluorocarbon, insulating property, and hygroscopicity. above, wherein the cyclic ketals or cyclic acetals comprise a 1,3-dioxolan Structure and/or a 1,3-dioxane Structure; It is another object of the present invention to provide (6) The synthetic lubricating oil as described in any one of novel cyclic acetals Suitably used for Synthetic lubricating 25 (3) to (5) above, comprising cyclic ketals or cyclic acetals oils and refrigeration oils. It is still another object of the obtained by a reaction between present invention to provide a method for producing the a tetrahydric or hexahydric Saturated aliphatic alcohol hav novel cyclic acetals in high yield by Simple procedures. ing 4–25 carbon atoms and As a result of intensive research in view of the above one or more carbonyl compounds represented by the general objects, the present inventors noted ether compounds as a formula (II), Structure which does not generate carboxylic acid or carbon or one or more ketals or acetals which are reactive deriva dioxide and found that ketals or acetals having a certain tives of Said carbonyl compounds, Structure have extremely high insulating properties. The (7) A Synthetic lubricating oil comprising one or more cyclic inventorS Succeeded in obtaining a compound having good ketals or cyclic acetals represented by the general formula compatibility with hydrofluorocarbons and high insulating (illa), (iii), (iva), or (IVb). property/low hygroscopicity at the same time, which the conventional ether compounds do not have, and have com (IIIa) pleted the present invention. O In brief, the present invention is concerned with: 40 R-C-O (1) A Synthetic lubricating oil comprising cyclic ketals or d h CH cyclic acetals obtained by a reaction between one or more Yot?/ st? CHNC 1-2YO polyhydric alcohols having an even number of hydroxyl RN \ /R groups of not less than 4 and not more than 10 and one or A-No O-C 4 more carbonyl compounds represented by the general for 45 R4 R mula (I): (IIIb) R3 R4 (I) y ( 50 ry i? CH r CH it is O O O O wherein R' represents a hydrogen atom or a linear, 55 N1 n1 branched, or cyclic alkyl group having 1-18 carbon atoms, /V / V R represents a linear, branched, or cyclic alkyl group R3 R4 R3 R4 having 1-18 carbon atoms; R' and R together may repre (IVa) Sent an alkylene group having 2-36 carbon atoms, or one or R4 more ketals or acetals which are reactive derivatives of the carbonyl compounds, 60 R - (2) A Synthetic lubricating oil comprising cyclic ketals or O CH CH2 cyclic acetals obtained by a reaction between one or more YoH, s p polyhydric alcohols having an even number of hydroxyl O-C-R groups of not leSS than 4 and not more than 8 and one or 65 I more carbonyl compounds represented by the general for R3 mula (II): 6,096,692 7 8 -continued -continued (IVb) (ii)

o1 C No -CH -CH2 CH, CH

wherein R represents a hydrogen atom and R represents a wherein R represents a hydrogen atom or a linear, branched alkyl group having 3 carbon atoms or a linear or 15 branched alkyl group having 4–21 carbon atoms; or R branched, or cyclic alkyl group having 1-12 carbon atoms, represents a linear or branched alkyl group having 1-21 R" represents a linear, branched, or cyclic alkyl group carbon atoms, and R represents a linear or branched alkyl having 1-12 carbon atoms, or R or R' together may group having 2-21 carbon atoms, (12) The cyclic acetals as described in (11) above, wherein represent an alkylene group having 2-13 carbon atoms, a R represents a hydrogen atom, and R represents a total carbon atoms of R and R' being 1-13; branched alkyl group having 3 carbon atoms or a linear or (8) A Synthetic lubricating oil comprising one or more cyclic branched alkyl group having 4–12 carbon atoms; or R ketals or cyclic acetals represented by the general formula represents a linear or branched alkyl group having 1-12 (V) or (VI): carbon atoms, and R represents a linear or branched alkyl group having 2-12 carbon atoms, (V) 25 (13) The cyclic acetals as described in (11) above, wherein R represents a hydrogen atom, and R represents a R4 R3 branched alkyl group having 3-12 carbon atoms; or R f Y-n represents a linear or branched alkyl group having 1-12 R - - carbon atoms, and R represents a linear or branched alkyl OYo?? CHYCH OYo, -CH CH,-O group having 2-12 carbon atoms, (14) The cyclic acetals as described in any one of (11) to (13) (VI) above, wherein a hexahydric alcohol residue is derived from R O-CH CH, CH, CH, CH2CH2-O R Sorbitol; (15) A method for producing the cyclic acetal represented by y/ O \/ \/ /V /V /\ 35 the general formula (i) or (ii) as described in (11) above, R" O-CH Y1 N. CH-O R' comprising: reacting hexahydric alcohols represented by the following wherein R represents a hydrogen atom or a linear, formula (iii): branched, or cyclic alkyl group having 1-12 carbon atoms, 40 (iii) R" represents a linear, branched, or cyclic alkyl group OH OH OH OH having 1-12 carbon atoms, or R and R together may represent an alkylene group having 2-13 carbon atoms, a HO-CH-CH-CHH-CH-CH-CH-OH total carbon atoms of R and R' being 1-13; (9) A working fluid composition for a refrigerating machine 45 with carbonyl compounds represented by the following comprising a refrigeration oil containing the cyclic ketals or formula (iv): cyclic acetals described in any one of (2) to (8) above and a hydrofluorocarbon; (iv) (10) The working fluid composition for a refrigerating R5 machine as described in (9) above, wherein the hydrofluo 50 C= rocarbon and the refrigerating oil are contained at R6 hydrofluorocarbon/refrigerating oil (weight ratio) of 50/1 to 1/20; wherein R represents a hydrogen atom, and R represents (11) Cyclic acetals represented by the following general 55 a branched alkyl group having 3 carbon atoms or a linear or formula (i) or (ii): branched alkyl group having 4–21 carbon atoms; or R represents a linear or branched alkyl group having 1-21 carbon atoms and R represents a linear or branched alkyl (i) group having 2-21 carbon atoms, R5 R5 or with a reactive derivative thereof (ketals or acetals), in the 60 presence of an acid catalyst; and (16) The method as described in (15) above, wherein the /- veO O hexahydric alcohol is sorbitol. O N BEST MODE FOR CARRYING OUT THE R5 O 65 INVENTION The present invention encompasses a Synthetic lubricat ing oil and a working fluid composition for a refrigerating 6,096,692 9 10 machine comprising Specific cyclic ketals or cyclic acetals. becomes poor, and, therefore, undesirable when used for Among the cyclic ketals or cyclic acetals, novel compounds insulating oils or working fluid compositions for a refriger having particular Structures are also encompassed by the ating machine. Examples of the polyhydric alcohols having present invention. In the present Specification, for the con no ether bond in the molecule include erythritol, Sorbitol, Venience Sake, the former is referred to as the first invention mannitol, galactitol, iditol, talitol, allitol, and pentaerythri and the latter as the Second invention, and both the inven tol; and examples of the polyhydric alcohols having one tions are hereinafter described Separately. First, the first ether bond include diglycerol, ditrimethylolpropane, and invention is described. ditrimethylolethane. Polyhydric alcohols used in the first invention are poly When the cyclic ketals or cyclic acetals in the first hydric alcohols having an even number of hydroxyl groups invention are used for a working fluid composition for a of not less than 4 and not more than 10. When the number refrigerating machine, the polyhydric alcohols have prefer of hydroxyl groups of a polyhydric alcohol is an odd ably 4, 6, or 8 hydroxyl groups, more preferably 4 or 6 number, hydroxyl groups are necessarily to remain hydroxyl groups. When the number of hydroxyl groups of unchanged, which undesirably makes the Viscosity high. In the polyhydric alcohols is more than 8, the Viscosity case where the product is used for a working fluid compo 15 becomes too high, and compatibility with hydrofluorocar Sition for a refrigerating machine, unchanged hydroxyl bons becomes poor. When the number of hydroxyl groups is groups impair compatibility with hydrofluorocarbon unde less than 4, molecular weight becomes undesirably low, Sirably. Though Viscosity and compatibility can be improved thereby making the boiling and flashing points undesirably by alkylating the unchanged hydroxyl groups to form an low. The number of carbon atoms is preferably 4-20, more ether Structure, this undesirably increases the number of preferably 4-15, still more preferably 4-10. When the reaction Steps in the production process. This increase in number of carbon atoms is more than 20, compatibility with reaction Step also makes it difficult to obtain the product of hydrofluorocarbon becomes undesirably poor. When the high purity. Specifically, examples include polyhydric alco number of carbon atoms is less than 4, molecular weight hols Such as erythritol, diglycerol, arabinose, ribose, becomes too low, thereby making boiling and flashing points Sorbitol, mannitol, galactitol, iditol, talitol, allitol, 4,7- 25 undesirably low. When an alcohol with highly symmetric dioxadecane-1,2,9,10-tetrol, 5-methyl-4,7-dioxadecane-1,2, Structure, Such as pentaerythritol, is used, the cyclic ketals or 9,10-tetrol, 4,7,10-trioxatridecane-1,2,12,13-tetrol, 1,6- cyclic acetals obtained become unsuitable for the use in a dimethoxyhexane-2,3,4,5-tetrol, and 3,4-diethoxyhexane-1, working fluid composition for a refrigerating machine 2,5,6-tetrol; and hindered alcohols Such as pentaerythritol, because melting point becomes high. dit rim ethyl ole thane, ditri methyl ol propane, The carbonyl compounds used in the first invention are dipentaerythritol, tripentaerythritol, 2,9-diethyl-2,9- ketones or aldehydes represented by the following general dihydroxymethyl-4,7-dioxadecane-1,10-diol, and 2,12 diethyl-2,12-dihydroxymethyl-5,8-dimethyl-4,7,10 formula (I): trioxatridecane-1,13-diol. Of the above examples, (I) polyhydric alcohols having 2 or more ether bonds, Such as 35 4,7-dioxadecane-1,2,9,10-tetrol, 5-methyl-4,7-dioxadecane 12.9,10-tetrol, 4,7,10-trioxatridecane-1,2,12,13-tetrol, 1,6- dimethoxyhexane-2,3,4,5-tetrol, 3,4-diethoxyhexane-1,2,5, 6-tetrol, 2,9-diethyl-2,9-dihydroxymethyl-4,7-dioxadecane 1,10-diol, and 2,12-diethyl-2,12-dihydroxymethyl-5,8- 40 The number of carbon atoms of the ketones or aldehydes dimethyl-4,7,10-trioxatridecane-1,13-diol, are difficult to represented by the general formula (I) is 2-37, preferably obtain on an industrial Scale, and require Several Steps for 2-25, more preferably 2-17. When the number of carbon production thereof, resulting in undesirably high cost. atoms is more than 37, Viscosity of the cyclic ketals or cyclic The polyhydric alcohols used in the first invention have 4, acetals obtained becomes undesirably high. 6, 8, or 10 hydroxyl groups, preferably 4, 6, or 8 hydroxyl 45 R" is a hydrogen atom, or a linear, branched, or cyclic groups, more preferably 4 or 6 hydroxyl groups. When the alkyl group having 1-18 carbons atoms, preferably a hydro number of hydroxyl groups is more than 10, Viscosity of the gen atom, or a linear, branched, or cyclic alkyl group having obtained cyclic ketals or cyclic acetals becomes too high. 1-12 carbon atoms, more preferably a hydrogen atom, or a When the number is less than 4, the molecular weight linear, branched or cyclic alkyl group having 1-8 carbon becomes too low, making boiling and flashing points unde 50 atoms. R is a linear, branched, or cyclic alkyl group having sirably low. 1-18 carbon atoms, preferably a linear, branched, or cyclic The polyhydric alcohols used in the first invention have alkyl group having 1-12 carbon atoms, more preferably a 4-25 carbon atoms, preferably 4-20 carbon atoms. When linear, branched or cyclic alkyl group having 1-8 carbon the number of carbon atoms is more than 25, the viscosity atoms. Alternatively, R and R together may form an of the cyclic ketals or cyclic acetals obtained becomes too 55 alkylene group having 2-36 carbon atoms, preferably 2-24 high. When the number of carbon atoms is less than 4, the carbon atoms, more preferably 2-16 carbon atoms. R' and molecular weight becomes too low, making boiling and R may or may not be identical. flashing points undesirably low. When the number of carbon atoms of R' or R is more The polyhydric alcohols used in the first invention are 60 than 18, Viscosity of the cyclic ketals or cyclic acetals Saturated aliphatic alcohols. When there is an unsaturated obtained becomes undesirably high. When the number of bond, thermal stability becomes undesirably poor. carbon atoms of the alkylene group which R' and R' In View of good insulating property, it is the most pref together form is more than 36, Viscosity of the cyclic ketals erable for the polyhydric alcohols used in the first invention or cyclic acetals obtained becomes undesirably high. not to have any ether bond in the molecule. If any, it is 65 Examples of ketones in which both R" and R are alkyl preferable to limit the number of ether bond to one. When groups include acetone, methyl ethyl ketone, methyl propyl there are two or more ether bonds, insulating property ketone, diethyl ketone, methyl isopropyl ketone, methyl 6,096,692 11 12 butyl ketone, ethyl propyl ketone, methyl Sec-butyl ketone, represents a hydrogen atom, or a linear, branched, or cyclic methyl isobutyl ketone, ethyl isopropyl ketone, methyl tert alkyl group having 1–5 carbon atoms. R" represents a linear, butyl ketone, methyl amylketone, ethylbutyl ketone, diiso branched, or cyclic alkyl group having 1-12 carbon atoms, propyl ketone, methyl isoamyl ketone, dipropyl ketone, preferably a linear, branched, or cyclic alkyl group having isopropyl propyl ketone, methyl neopentyl ketone, ethyl 1-8 carbon atoms, more preferably a linear, branched, or tert-butyl ketone, methylhexyl ketone, ethyl pentyl ketone, cyclic alkyl group having 1-5 carbon atoms. Alternatively, 6-methyl-2-heptanone, 4-methyl-3-heptanone, 2-methyl-3- RandR together represent an alkylene group having 2–13 heptanone, 5-methyl-3-heptanone, methyl cyclohexyl carbon atoms, preferably an alkylene group having 4-10 ketone, methyl heptyl ketone, ethyl hexyl ketone, dibutyl carbon atoms, more preferably an alkylene group having ketone, diisobutyl ketone, methyl octyl ketone, methylnonyl 4-5 carton atoms. The total number of carbon atoms of R ketone, dipentyl ketone, methyl decyl ketone, methyl unde and R' is 1-13, preferably 1-10, more preferably 1-5. cyl ketone, dihe Xyl ketone, 5-(2', 2', When the number of carbon atoms of R or R' is more 5'-trimethylcyclohexyl)-2-pentanone, 6,10-dimethyl-2- than 12, compatibility of the cyclic ketals or cyclic acetals undecanone, methyl tridecyl ketone, diheptyl ketone, methyl obtained with hydrofluorocarbons becomes undesirably tetradecyl ketone, dioctyl ketone, methylpentadecyl ketone, 15 poor. When the number of carbon atoms of the alkylene disooctyl ketone, methyl hexadecyl ketone, 6,10,14 group which R and R' together form is more than 13, trimethyl-2-pentadecanone, dinonyl ketone, methyl hepta compatibility of the cyclic ketals or cyclic acetals obtained decyl ketone, methyl octadecyl ketone, and didecyl ketone. with hydrofluorocarbons becomes undesirably poor. When Examples of ketones in which R" and R together form an the total number of carbon atoms of R and R is more than alkylene group include cyclopropanone, cyclobutanone, 13, compatibility of the cyclic ketals or cyclic acetals cyclopentanone, cyclohexanone, 2-methylcyclopentanone, obtained with hydrofluorocarbons becomes undesirably 3-methylcyclopentanone, 2-methylcyclohexanone, poor. 3-methylcyclohexanone, 4-methylcyclohexanone, From the viewpoint of compatibility with cycloheptanone, 2,4-dimethylcyclohexanone, 2,6- hydrofluorocarbons, the alkyl group represented by R or R' dimethylcyclohe X a none, cyclooctan one, 25 is preferably branched or cyclic rather than linear, and it is 2-ethylcyclohe Xanone, 3-ethylcyclohe Xanone, preferred for R and R' together not to form an alkylene 4-ethylcyclohexanone, 3,3,5-trimethylcyclohexanone, group rather than to form an alkylene group. 2-tert-butylcyclohexanone, 4-tert-butylcyclohexanone, Ketones used in the first invention and represented by the 2-isopropyl-4-methylcyclohexanone, cyclodecanone, and general formulas (I) or (II) are readily obtained by high cyclododecanone. temperature decarboxylating dimerization of fatty acids, Examples of aldehydes in which R" is a hydrogen atom catalytic oxidation of olefins (Wacker process), oxidation or include acetaldehyde, propionaldehyde, butyraldehyde, dehydrogenation of Secondary alcohols, and oxidation of isobutyraldehyde, Valeraldehyde, isovaleraldehyde, cycloalkanes. Ketones obtained by Wacker process can be 2-methylbutyraldehyde, caproaldehyde, 2-methylpentanal, Separated and purified by rectification. Aldehydes used in 3 -methylpentanal, 4-methylpentanal, 2-ethylbutanal, 2,3- 35 the first invention and represented by the general formulas dimethylbutanal, 3,3 - dimethylbut anal, (I) or (II) are readily prepared by, for example, dehydroge cyclopenty lacetaldehyde, heptanal, 2-methylhexanal, nation of fatty alcohols, hydroformylation of olefins (oxo 3-methylhexanal, 4-methylhexanal, 5-methylhexanal, method), Rosenmund reduction of fatty acid chlorides, and 2-ethylpentanal, cyclohexylace taldehyde, octanal, direct hydrogenation of fatty acids. In the case of the oxo 2-methylheptanal, 2-ethylhexanal, 2-propylpentanal, 2,4,4- 40 method, both linear and branched aldehydes are produced, trimethylpentanal, nonylaldehyde, 3,5,5-trimethylhexanal, but they can be separated and purified by rectification. decylaldehyde, isodecylaldehyde, 3,7-dimethyloctanal, 2-isopropyl-5-methylhexanal, undecanal, dodecanal, Reactive derivatives of carbonyl compounds used in the tridecylaldehyde, isotridecylaldehyde, hexadecanal, first invention are ketals and acetals which can readily be 45 obtained by the reaction of a ketone or aldehyde as men isooctadecanal, octadecanal, and 2-methyloctadecanal. tioned above with a lower alcohol having 1-6 carbon atoms When the cyclic ketals or cyclic acetals in the first in the presence of an acid catalyst. Examples of lower invention are used in a base oil for a working fluid compo alcohols having 1-6 carbon atoms include methanol, Sition for a refrigerating machine, ketones or aldehydes ethanol, propanol, isopropyl alcohol, butanol, isobutyl represented by the general formula (II) are preferred among 50 alcohol, Sec-butyl alcohol, tert-butyl alcohol, amyl alcohol, those represented by the general formula (I). isoamyl alcohol, neopentyl alcohol, 1-methylbutanol, 1,1- dimethylpropanol, 1-ethylpropanol, hexanol, isohexyl (II) alcohol, 2-ethylbutanol, 1-methylamyl alcohol, 1,3- R dimethylbutanol, and 1-ethylbutanol. C=O 55 The cyclic ketals or cyclic acetals used in the first inven R4 tion can be obtained as described below. The reaction between a polyhydric alcohol and a ketone above is ketal ization. This reaction requires an acidic catalyst, Such as Ketones or aldehydes represented by the general formula p-tolueneSulfonic acid, methaneSulfonic acid, and Sulfuric (II) have 2–25 carbon atoms, preferably 2-17 carbon atoms, 60 acid in an amount of 0.1 to 10 mole %, preferably 1.0 to 7.0 more preferably 2-11 carbon atoms. When the number of mole %, and more preferably 1.0 to 5.0 mole % to the carbon atoms is more than 25, compatibility with hydrof amount of the polyhydric alcohol. This reaction may be luorocarbons becomes undesirably poor. carried out without Solvents, or in an inert Solvent Such as R represents a hydrogen atom, or a linear, branched, or Xylene, toluene, benzene, octane, isooctane, heptane, cyclic alkyl group having 1-12 carbon atoms, preferably it 65 hexane, cyclohexane, pentane, ligroin, and petroleum ether, represents a hydrogen atom, or a linear, branched, or cyclic or in a mixture of these Solvents. The reaction temperature alkyl group having 1-8 carbon atoms, more preferably it depends upon the boiling point of the ketone used, and the 6,096,692 13 14 reaction is preferably carried out at a temperature of from 40 The reaction between a polyhydric alcohol and an acetal, to 130° C., preferably from 60 to 100° C., while removing a reactive derivative of aldehyde, is transacetalization. This the water formed in the process of the reaction. There are reaction requires an acidic catalyst, Such as also Some cases where the reaction can effectively be carried p-tolueneSulfonic acid, methaneSulfonic acid, and Sulfuric out under a reduced preSSure. When the temperature is lower 5 acid, in an amount of 0.01 to 5.0 mole %, preferably 0.1 to than the above range, the reaction does not proceed; and 2.0 mole %. This reaction may be carried out without when the temperature is higher than the above range, marked Solvents or in an inert Solvent Such as Xylene, toluene, coloration and Side reactions undesirably occur. Also, the benzene, octane, isooctane, heptane, hexane, cyclohexane, reaction may be carried out in a nitrogen Stream, nitrogen pentane, butane, ligroin, and petroleum ether, or in a mixture atmosphere, or dry air. The reaction time varies with reaction of these Solvents. The reaction temperature depends upon conditions employed, but it is generally preferred to con the boiling point of the acetal used and the lower alcohol tinue the reaction for 5 to 200 hours. After neutralization, the formed, and the reaction is carried out at a temperature of cyclicketals obtained are Subjected to pretreatments, Such as from 20 to 150° C., preferably from 50 to 130° C., while filtration and washing, and then can be purified by Such removing the lower alcohol formed in the process of the means as clay adsorption, crystallization, and distillation. reaction. There are also Some cases where the reaction can The reaction between a polyhydric alcohol and above 15 aldehyde is acetalization. This reaction requires an acidic effectively be carried out under a reduced pressure. When catalyst, Such as p-toluenesulfonic acid, methaneSulfonic the temperature is lower than the above range, the reaction acid, and Sulfuric acid, in an amount of 0.01 to 5.0 mole %, does not proceed; and when the temperature is higher than preferably 0.1 to 2.0 mole % to the amount of the polyhydric the above range, marked coloration and Side reactions unde alcohol. This reaction may be carried out without Solvents, Sirably occur. Also, the reaction may be carried out in a or in an inert Solvent Such as Xylene, toluene, benzene, nitrogen Stream, nitrogen atmosphere, or dry air. The reac octane, isooctane, heptane, hexane, cyclohexane, pentane, tion time varies with reaction conditions employed, but it is butane, ligroin, and petroleum ether, or in a mixture of these generally preferred to continue the reaction for 1 to 30 hours. Solvents. The reaction temperature depends upon the boiling After neutralization, the cyclic acetals obtained are Sub point of the aldehyde used, and the reaction is preferably 25 jected to pretreatments, Such as filtration and washing, and carried out at a temperature of from 20 to 130 C., preferably then can be purified by Such means as clay adsorption, from 40 to 100° C., while removing the water formed in the crystallization, and distillation. process of the reaction. There are also Some cases where the The ratio of a polyhydric alcohol to a ketone or a ketal, a reaction can effectively be carried out under a reduced reactive derivative of ketone, or to an aldehyde or an acetal, pressure. When the temperature is lower than the above a reactive derivative of aldehyde (hereinafter ketone, ketal, range, the reaction does not proceed; and when the tempera aldehyde, and acetal are simply referred to as a carbonyl ture is higher than the above range, marked coloration and compound) is A/2 moles of carbonyl compound to 1 mole of Side reactions undesirably occur. Also, the reaction may be polyhydric alcohol (Ameans the number of hydroxyl groups carried out in a nitrogen Stream, nitrogen atmosphere, or dry of a polyhydric alcohol). It is also effective to carry out the air. The reaction time varies with reaction conditions 35 reaction with more than A/2 moles of a carbonyl compound employed, but it is generally preferred to continue the to facilitate the reaction, with removal of the excessive reaction for 1 to 30 hours. After neutralization, the cyclic carbonyl compound after the completion of the reaction. acetals obtained are Subjected to pretreatments, Such as The cyclicketals or cyclic acetals in the first invention can filtration and washing, and then can be purified by Such be obtained by reacting one or more polyhydric alcohols means as clay adsorption, crystallization, and distillation. 40 with one or more ketones or ketals, the reactive derivatives The reaction between a polyhydric alcohol and a ketal, a of ketones, or with one or more aldehydes or acetals, the reactive derivative of ketone, is transketalization. This reac reactive derivatives of aldehydes. Also, cyclic ketals and tion requires an acidic catalyst, Such as p-toluenesulfonic cyclic acetals, which are Separately produced, may be mixed acid, methaneSulfonic acid, and Sulfuric acid, in an amount before use. For example, the cyclic ketal (viscosity of 63.1 of 0.1 to 10 mole %, preferably 1.0 to 7.0 mole %, and more 45 mm/s at 40° C) obtained from 1 mole of sorbitol and 3 preferably 1.0 to 5.0 mole % to the amount of the polyhydric moles of methyl ethyl ketone may be mixed with the cyclic alcohol. This reaction may be carried out without solvents or ketal (viscosity of 7.69 mm /s at 40° C.) obtained from 1 in an inert Solvent Such as Xylene, toluene, benzene, octane, mole of diglycerol and 2 moles of methyl ethyl ketone to isooctane, heptane, hexane, cyclohexane, pentane, ligroin, achieve a desired Viscosity. Specifically, when 1 mole of the and petroleum ether, or in a mixture of these Solvents. The 50 cyclic ketal obtained from 1 mole of Sorbitol and 3 moles of reaction temperature depends upon the boiling points of the methyl ethyl ketone is mixed with 1 mole of the cyclic ketal ketal used and the lower alcohol formed, and the reaction is obtained from 1 mole of diglycerol and 2 moles of methyl preferably carried out at a temperature of from 40 to 150 C., ethyl ketone, a lubricating oil with VG 22 can be obtained. preferably from 70 to 130 C., while removing the lower The above mixture can also be obtained by the reaction alcohol formed in the process of the reaction. There are also 55 among 1 mole of Sorbitol, 1 mole of diglycerol, and 5 moles Some cases where the reaction can effectively be carried out of methyl ethyl ketone. It is also possible to obtain the cyclic under a reduced pressure. When the temperature is lower ketals or cyclic acetals in the first invention by the reaction than the above range, the reaction does not proceed; and between 1 mole of Sorbitol and 2 kinds of ketones or when the temperature is higher than the above range, marked aldehydes, for example, 2 moles of 3,5,5-trimethylhexanal coloration and Side reactions undesirably occur. Also, the 60 and 1 mole of methyl ethyl ketone. reaction may be carried out in a nitrogen Stream, nitrogen It is preferable that the number of hydroxyl groups atmosphere, or dry air. The reaction time varies with reaction remaining unchanged in the cyclic ketals or cyclic acetals conditions employed, but it is generally preferred to con obtained is as Small as possible. The average number of Such tinue the reaction for 5 to 200 hours. After neutralization, the unchanged hydroxyl groups accounts for not more than 20% cyclicketals obtained are Subjected to pretreatments, Such as 65 of the number of hydroxyl groups of the Starting polyhydric filtration and washing, and then can be purified by Such alcohol, preferably not more than 10%, more preferably not means as clay adsorption, crystallization, and distillation. more than 5%, still more preferably not more than 3%. 6,096,692 15 16 When more than 20% of hydroxyl groups remain those represented by formulas (IIIa), (IIIb), (IVa) and (V), unchanged, Viscosity becomes undesirably high and boiling which have 1,3-dioxolan Structures, are preferable. Among and flashing points become undesirably low. When the them, compounds represented by formulas (IIIa), (IVa) and cyclic ketals or cyclic acetals are used as a base oil for a working fluid composition for a refrigerating machine, it is (V), which have only 1,3-dioxolan structures, are more particularly preferable that the number of unchanged preferable. Among them, compounds represented by (IIIa) hydroxyl groups is as Small as possible. It is not more than and (IVa), which have no ether bond in the polyhydric 10%, preferably not more than 5%, more preferably not alcohol moiety, are Still more preferable. more than 3%, still more preferably not more than 2%, most preferably not more than 1%. When more than 10% of hydroxyl groups remain unchanged, compatibility with The melting point of the cyclic ketals or cyclic acetals in hydrofluorocarbons and insulating property become unde the first invention is preferably not more than 10 C., more Sirably poor. preferably not more than -10° C., still more preferably not When the cyclic ketals or cyclic acetals in the first more than -30°C. Though it is not preferable to singly use invention are used as an insulating oil, or as a base oil for a 15 as a lubricating oil the cyclic ketals or cyclic acetals repre working fluid composition for a refrigerating machine, poly hydric alcohols without ether bonds are preferable because sented by formulas (VIIa) and (VIIb) of which melting point of high insulating property. Therefore, cyclic ketals or cyclic exceeds 10 C., they can be used in a limited amount by acetals obtained from hexahydric alcohols Such as Sorbitol, blending them with the other cyclic ketals or cyclic acetals mannitol, galactitol, iditol, talitol, and allitol, or polyhydric with low melting points in the first invention or other alcohols Such as erythritol, are more preferable than cyclic lubricating oils. ketals or cyclic acetals obtained from alcohols having one ether bond Such as diglycerol and ditrimethylolpropane. (IIIa) When the cyclic ketals or cyclic acetals in the first R4 invention are used as an insulating oil or a base oil for a 25 I working fluid composition for a refrigerating machine, those R3-C-O having 1,3-dioxolan and/or 1,3-dioxane Structures are pre d An CH ferred because high insulating property is obtained. Of them, Yo??/ it?CH YCH / 2YO those having 1,3-dioxolan Structures are particularly pre RS (1 y ll-R ferred. Therefore, alcohols which have hydroxyl groups at A Nd) O-CN adjacent positions, Such as erythritol, diglycerol, Sorbitol, R4 R4 mannitol, galactitol, iditol, talitol, and allitol, are preferably (IIIb) used. Also, when hexahydric alcohols, Such as Sorbitol, 3 4 mannitol, galactitol, iditol, talitol, and allitol, are used, RS-R cyclic ketals or cyclic acetals represented by formulas (IIIa) 35 ry and (IIIb) are obtained, of which those represented by CH CH formula (IIIa) having three 1,3-dioxolan structures are pre ferred because high insulating property is obtained. When f r yr-". erythritol is used, cyclic ketals or cyclic acetals represented O O O O by formulas (IVa) and (IVb) are obtained, of which those 40 S. S. represented by formula (IVa) having two 1,3-dioxolan struc R3 Y. R3 Y. tures are preferred because high insulating property is (IVa) obtained. Hexahydric alcohols Such as Sorbitol, mannitol, R4 galactitol, iditol, talitol, and allitol, or erythritol tend to give –4 cyclic ketals represented by formulas (IIIa) and (IVa), when 45 R - - being allowed to react with ketones or ketals, and they tend OS-CH -CH: to give cyclic acetals represented by formulas (IIIb) and CH2 CH O (IVb), when being reacted with aldehydes or acetals. Y--O-C-R A Therefore, these alcohols are preferably made to react with R3 ketones or ketals. 50 When the cyclic ketals or cyclic acetals in the first (IVb) invention are used as a base oil for a working fluid compo 3 4 Sition for a refrigerating machine, among cyclic ketals or RS-R cyclic acetals obtained from polyhydric alcohols having an ry even number of hydroxyl groups, cyclic ketals or cyclic 55 CH -CH2 acetals obtained from hexahydric alcohols represented by fl. y formula (III) and cyclic ketals or cyclic acetals obtained O O from tetrahydric alcohols, Such as erythritol, diglycerol and ditrimethylolpropane, represented by formulas (IV) to (VI), S.R3 Y: are particularly preferable because various physical 60 properties, Such as compatibility with hydrofluorocarbons, (V) insulating property, melting point, and Viscosity, are in good R4 R3 I V balance. Cyclic ketals represented by formulas (VIIa) and R3-C-O O-C-R (VIIb) which are obtained from highly symmetric pen taerythritol are not preferable because they become Solid at 65 d h O h O room temperature, even though the alcohol is tetrahydric. Yo?? Not Not? of Among the compounds represented by formulas (III) to (VI), 6,096,692 17 18 -continued fluid composition for a refrigerating machine as a mixture (VI) with hydrofluorocarbons. Also, it can be used as insulating oils because of good insulating property. Since it has R3 p-cy. CH, CH 'y'-y intramolecular ring Structures, it can be used as traction oils. Good lubricity and high heat resistivity make them usable V O for engine and turbine oils, gear oils, hydraulic oils, bearing R4 o–ci? Y1 N. YH-6 Y: oils, metal working fluids, compressor oils, grease base oils, (VIIa) and the like. It can also be used as an additive for low Sulfur i Bu,V /O-CH V /CH-O V /iBu gas oils because of its high lubricity. Since it has many C C C oxygen atoms in the molecule, it can be used as an additive / \ / \ /\ for fuel oils Such as octane value booster. Bl O-CH CH-O Bu When the cyclic ketals or cyclic acetals in the first (VIIb) invention are used as a base oil for a working fluid compo Me, O-CH2 CH-O Me Sition for a refrigerating machine, the mixing ratio of hydrof 15 luorocarbons with a refrigeration oil containing the cyclic ketals or cyclic acetals used in the present invention, i.e. Et O-CH CH-O Et hydrofluorocarbons/refrigeration oil, is normally 50/1 to 1/20 (weight ratio), preferably 10/1 to 1/5 (weight ratio). The cyclic ketals or cyclic acetals used in the first inven When the mixing ratio exceeds 50/1, the viscosity of the tion preferably have a viscosity at 100° C. of not less than mixed Solution of hydrofluorocarbons and a refrigeration oil 1 mm/s and not more than 100 mm/s, more preferably not becomes low, thereby making it likely to have undesirably less than 1 mm/s and not more than 50 mm/s, still more poor lubricity. When the mixing ratio of preferably not less than 1 mm/s and not more than 30 hydrofluorocarbons/refrigeration oil is lower than 1/20, the mm°/s. refrigeration capability is liable to become undesirably poor. When the cyclic ketals or cyclic acetals in the first 25 The hydrofluorocarbons used in the first invention include invention are used as a base oil for a working fluid compo difluoromethane (HFC32), 1,1-difluoroethane (HFC152a), Sition for a refrigerating machine, the two-phase Separation 1,1,1-trifluoroethane (HFC143a), 1,1,1,2-tetrafluoroethane temperature between the compounds and hydrofluorocar (HFC134a), 1,1,2,2-tetrafluoroethane (HFC134) and pen bons is preferably low, being not more than 10 C., prefer tafluoroethane (HFC125), with a particular preference given ably not more than 0° C., more preferably not more than to 1,1,1,2-tetrafluoroethane, difluorome thane, -10° C., still more preferably not more than -30° C. pentafluoroethane, and 1,1,1-trifluoroethane. These hydrof The cyclic ketals or cyclic acetals in the first invention luorocarbons may be used Singly or as a mixture of two or may be blended with other lubricating oils. Such other more kinds of hydrofluorocarbons. lubricating oils include mineral oils, hydrocarbon Synthetic To the cyclic ketals or cyclic acetals in the first invention, oils. Such as polybutenes, poly C-olefins, and alkylbenzenes, 35 conventional lubricating oil additives, Such as antioxidants, aliphatic diesters, neopentyl polyol esters, polyalkylene extreme pressure additives, oilineSS improvers, defoaming glycols, poly phenyl ethers, carbonates, phosphate esters, agents, detergent dispersants, Viscosity indeX improver, anti Silicate esters, Silicone oils, and perfluoropolyethers, Specific corrosive agents, and antiemulsifiers may be added accord examples of which are set forth in “New Edition of Physi ing to necessity. Examples of antioxidants used in the cochemistry of Lubrication” (Saiwai Shobo), “Basics and 40 present invention include phenol antioxidants, Such as 2,6- Application of Lubricating Oils' (Corona), etc. di-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, and 4,4'- The mixing ratio between the cyclic ketals or cyclic methylenebis(2,6-di-t-butylphenol); amine-based acetals in the first invention and other lubricating oils is Such antioxidants, Such as p, p-dioctylphenylamine, that the cyclic ketals or cyclic acetals are contained in the monooctyl diphenylamine, phenothia Zine, 3,7- blended lubricating oil in an amount of not less than 0.1% 45 dioctylphenothiazine, phenyl-1-naphthylamine, phenyl-2- by weight, preferably not less than 1.0% by weight, more naphthylamine, alkylphenyl-1-naphthylamine, and preferably not less than 5.0% by weight, still more prefer alkylphenyl-2-naphthylamine, Sulfur-based antioxidants, ably not less than 10% by weight. When the ratio is less than Such as alkyl disulfides, thiodipropionic acid esters, and 0.1% by weight, lubricity improving effect and preventive benzothiazoles, and Zinc dialkyl dithiophosphate and Zinc effect against hydrolysis of esters and carbonates are not 50 diaryl dithiophosphate. The amounts of the above additives sufficiently exerted. When the cyclic ketals or cyclic acetals are 0.05 to 2.0% by weight of the lubricating oil comprising in the first invention are used as a base oil for a working fluid the cyclic ketals and cyclic acetals in the first invention. composition for a refrigerating machine, the other lubricat Examples of the uSable extreme-pressure additives and ing oils to be added preferably have good compatibility with oilineSS improvers are Zinc compounds, Such as Zinc dialkyl hydrofluorocarbons, preferable examples of which include 55 dithiophosphates and Zinc diaryl dithiophosphates, Sulfur neopentyl polyol esters, polyalkylene glycols, and carbon compounds, Such as thiodipropionic acid esters, dialkyl ates. However, when the cyclicketals or cyclic acetals in the sulfides, dibenzyl sulfide, dialkyl polysulfides, alkyl first invention have sufficiently good compatibility with mercaptains, dibenzothiophene, and 2,2'-dithiobis hydrofluorocarbons, for example, when they have a two (benzothiazole); phosphorus compounds, Such as triaryl phase separation temperature of not more than -30° C., 60 phosphates, triaryl phosphites, trialkyl phosphites, and tri preferably not more than -50 C., lubricating oils which are alkyl phosphates, chlorine compounds, Such as chlorinated leSS compatible with hydrofluorocarbons, Such as alkylben paraffins, molybdenum compounds, Such as molybdenum Zenes and mineral oils, may be blended as long as two-phase dithiocarbamate, molybdenum dithiophosphate, and molyb separation temperature is below 10° C. denum disulfide; fluorine compounds, Such as perfluoroalkyl Since the cyclic ketals or cyclic acetals in the first 65 polyethers, trifluorochloro ethylene polymers, graphitefluo invention are good in both compatibility with hydrofluoro ride, Silica compounds, Such as fatty acid-modified sili carbons and insulating property, it can be used for a working cones; and graphites. The amount added is 0.05 to 10% by 6,096,692 19 20 weight of the lubricating oil containing the cyclic ketals or 0.003 to 0.5% by weight of the lubricating oil comprising the cyclic acetals in the first invention. cyclic ketals or cyclic acetals in the present invention. The Examples of usable defoaming agents are Silicone oils, metal deactivators used in the present invention are prefer Such as dimethylpolysiloxane, and organosilicates, Such as ably those with chelating ability and having 5-50 carbon diethyl silicate. The amount added is 0.0005 to 1% by atoms, preferably 5-20 carbon atoms. Specifically, examples weight of the lubricating oil comprising the cyclic ketals or include N,N'-disalicylidene-1,2-diaminoethane, N,N'- cyclic acetals in the first invention. disalicylidene-1,2-diaminopropane, N-Salicylidene-N'- Examples of usable detergent dispersants include dimethyl-1,2-diaminoethane, N,N'-disalicylidenehydrazine, Sulfonates, phenates, Salicylates, phosphonates, polybutenyl N,N'-bis(C,5-dimethylsalicylidene)-1,2-diaminoethane, Succinimides, and polybutenyl Succinic acid esters. The N,N'-bis(C,5-dimethylsalicylidene)-1,3-propanediamine, amount added is 0.05 to 10% by weight of the lubricating oil N,N'-bis(C,5-dimethylsalicylidnene)-1,6-hexanediamine, comprising the cyclic ketals and cyclic acetals in the first N,N'-bis(C,5-dimethylsalicylidene)-1,10-decanediamine, invention. N,N'-bis(C.,5-dimethylsalicylidene)ethylenetetramine, When the cyclic ketals or cyclic acetals in the first Salicylaldoxime, 2-hydroxy-5-methylacetophenoxime, invention are used as a base oil for a working fluid compo 15 acetyl acetone, acetoethyl acetate, aceto-2-ethylhexyl Sition for a refrigerating machine, addition of benzotriazole acetate, dimethyl malonate, diethyl malonate, 2-ethylhexyl and/or benzotriazole derivatives for protecting metal Sur malonate, anthranilic acid, nitrillotriacetic acid, face, triaryl phosphates and/or triaryl phosphites for improv dihydroxyethylglycine, hydroxyethyl ethylenediamine tri ing lubricity; and radical trapping additives Such as phenol acetic acid, hydroxyethylimino diacetic acid, compounds for improving thermal Stability and metal deac ethylenediamine, 3-mercapto-1,2-propanediol, alizarin, tivators with chelating ability are effective. quinizarin, and mercaptobenzothiazole, with preference Triaryl phosphates and triaryl phosphites used in the first being given to N,N'-disalicylidene-1,2-diaminoethane, invention are those having 18-70 carbon atoms, preferably N,N'-disalicylidene-1,2-diaminopropane, acetylacetone, 18-50 carbon atoms. Specifically, examples include triaryl acetoacetate, alizarine, and quinizarin. phosphates Such as triphenyl phosphate, tricresyl phosphate, 25 The amount of the phenol compounds having radical triXylenyl phosphate, creSyldiphenyl phosphate, Xylenyl trapping ability added in the first invention is normally 0.05 diphenyl phosphate, tris(tribromophenyl) phosphate, tris to 2.0% by weight, preferably 0.05 to 0.5% by weight of the (dibromophenyl) phosphate, tris(2,4-di-tert-butylphenyl) lubricating oil comprising the cyclic ketals or cyclic acetals phosphate and trinonylphenyl phosphate, and triaryl phoS in the present invention. Phenol compounds usable in the phites Such as triphenyl phosphite, tricresyl phosphite, trixy present invention are those having 6-100 carbon atoms, lenyl phosphite, creSyldiphenyl phosphite, Xylenyldiphenyl preferably 10-80 carbon atoms. Specifically, examples phosphite, tris(2,4-di-tert-butylphenyl) phosphite, include 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4- trinonylphenyl phosphite, tris(tribromophenyl) phosphite methylphenol, 4,4'-methylenebis(2,6-di-tert-butylphenol), and tris(dibromophenyl)phosphite, with preference given to 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 2,2'- triphenyl phosphate, tricresyl phosphate, triXylenyl 35 methylenebis(4-ethyl-6-tert-butylphenol), 2,2'-methylenebis phosphate, tris(2,4-di-tert-butylphenyl) phosphate, triphenyl (4-methyl-6-tert-butylphenol), 4,4'- phosphite, tricresyl phosphite, trixylenyl phosphite, and isopropylidenebisphenol, 2,4-dimethyl-6-tert-butylphenol, tris(2,4-di-tert-butylphenyl) phosphite. The amount of tri tetrakismethylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl) aryl phosphates and/or triaryl phosphites added is normally propionate methane, 1,1,3-tris(2-methyl-4-hydroxy-5-tert 0.1 to 5.0% by weight, preferably 0.5 to 2.0% by weight of 40 butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert the lubricating oil comprising the cyclic ketals and cyclic butyl-4-hydroxybenzyl)benzene, 2,2'-dihydroxy-3,3'-di(O- acetals in the first invention. methylcyclohexyl)-5,5-dimethyldiphenylmethane, 2,2'- The amount of benzotriazole and/or benzotriazole deriva isobutylidenebis(4,6-dimethylphenol), bis(3,3-bis-(4'- tives in the first invention added is normally 0.001 to 0.1% hydroxy-3'-tert-butylphenyl)butyric acid glycol ester, 2,6- by weight, preferably 0.003 to 0.03% by weight of the 45 bis(2'-hydroxy-3'tert-butyl-5'-methylbenzyl)-4- lubricating oil comprising the cyclic ketals or cyclic acetals methylphenol, 1,1'-bis(4-hydroxyphenyl)cyclohexane, 2.5- in the first invention. The benzotriazole and benzotriazole di-tert-amylhydroquinone, 2,5-di-tert-butylhydroquinone, derivatives used in the present invention are preferably those 1,4-dihydroxyanthraquinone, 3-tert-butyl-4-hydroxyanisole, having 6-50 carbon atoms, more preferably 6-30 carbon 2-tert-butyl-4-hydroxyanisole, 2,4-dibenzoyl resorcinol, atoms. Specifically, examples include benzotriazole, 50 4-tert-butylcatechol, 2,6-di-tert-butyl-4-ethylphenol, 5-methyl-1H-benzo triazole, 2-hydroxy-4-methoxyben Zophe none, 2,4- 1-dioctylaminomethylbenzotriazole, 1-dioctylaminomethyl dihydroxyben Zophe none, 2,2'-dihydroxy-4- 5-methylbenzotriazole, 2-(5'-methyl-2'-hydroxyphenyl) methoxybenzophenone, 2,4,5-trihydroxybenzophenone, benzotriazole, 2-2'-hydroxy-3',5'-bis(C,C-dimethylbenzyl) C.-tocopherol, bis(2-(2-hydroxy-5-methyl-3-tert phenyl-2H-benzotirazole, 2-(3',5'-di-tert-butyl-2'- 55 butylbenzyl)-4-methyl-6-tert-butylphenylterephthalate, tri hydroxyphenyl)benzotriazole, 2-(3'-tert-butyl-5-methyl-2'- ethylene glycol-bis3-(3-tert-butyl-5-methyl-4- hydroxyphenyl)-5-chlorobenzotriazole, 2-(3',5'-di-tert hydroxyphenyl) propionate, 1,6-hexanediol-bis3-(3,5-di butyl-2'-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3',5'-di tert-butyl-4-hydroxyphenyl) propionate), 3.9-bis(2-(3-tert tert-amyl-2'-hydroxyphenyl)benzotriazole, 2-(5'-tert-butyl butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1- 2'-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'- 60 dimethylethyl-2,4,8,10-tetraoxaspiro5.5undecane, with methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert preference being given to 2,6-di-tert-butylphenol, 2,6-di octylphenyl)benzotriazole and 2-2'-hydroxy-3'-(3",4",5", tert-butyl-4-methylphenol, 4,4'-methylenebis(2,6-di-tert 6"-tetrahydrophthalimide-methyl)-5'-methylphenyl butylphenol), 4,4'-butylide nebis(3-methyl-6-tert benzotriazole, with preference being given to benzotriazole butylphenol), 2,2'-methylene bis(4-ethyl-6-tert and 5-methyl-1H-benzotriazole. 65 butylphenol), 2,2'-methylenebis(4-methyl-6-tert The amount of the metal deactivators usable in the first butylphenol), 4,4'-isopropylidenebisphenol, 2,4-dimethyl-6- invention is normally 0.001 to 2.0% by weight, preferably tert-butylphenol, tetrakismethylene-3-(3',5'-di-tert-butyl-4- 6,096,692 21 22 hydroxyphenyl)propionate methane, 1,1,3-tris(2-methyl-4- Specifically, the examples of linear alkyls include butyl, hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6- pentyl, hexyl, heptyl, octyl, nonyl, undecyl, tridecyl, tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 2,6-di-tert pentadecyl, heptadecyl, nonadecyl, and heneicosyl. butyl-4-ethylphenol, 2,6-bis(2'-hydroxy-3'-tert-butyl-5'- Examples of C.-methyl-branched alkylS include methylbenzyl)-4-methylphenol, bis(2-(2-hydroxy-5-methyl 1-methylpropyl, 1-methylbutyl, 1-methylpentyl, 3-tert-butylbenzyl)-4-methyl-6-tert-butylphenyl 5 1-methylhexyl, 1-methylheptyl, 1-methyloctyl, terephthalate, triethylene glycol bis3-(3-tert-butyl-5- 1-methylnonyl, 1-methyldecyl, 1-methylundecyl, and methyl-4-hydroxyphenyl)propionate, and 1,6-hexanediol 1-methyloctadecyl. bis3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate). Examples of C.-branched alkyls include 1-ethylpropyl, 1-ethylbutyl, 1-ethylpentyl, 1-propylbutyl, 1-ethylhexyl, Additives Stabilizing freon refrigerants, Such as organic 1-propylpentyl, 1-ethylheptyl, 1-propylhexyl, 1-butylpentyl, tin compounds and boron compounds, may be added. The 1-pentylhexyl, 1-hexylhepty l, 1- octylnonyl, amount added is 0.001 to 10% by weight of the lubricating 1-hexylundecyl, and 1-decylundecyl. oil comprising the cyclic ketals or cyclic acetals in the first Examples of C- and other polybranched alkyls having one invention. or more branches at positions other than C-position include Next, the second invention will be described. 15 1,2-dimethylpropyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, Among the cyclic ketals and the cyclic acetals in the first 1-ethyl-2-methylpropyl, diisopropylmethyl, 1,4- invention, compounds represented by formulas (IIIa) and dimethylpentyl, 1-isopropylbutyl, 1,3,3-trimethylbutyl, 1,5- (IIIb) are novel compounds. The invention concerning the dimethylhexyl, 1-ethyl-2-methylpenty 1, 1-butyl-2- cyclic acetals including these compounds (those represented methylpropyl, 1-ethyl-3-methylpentyl, diisobutylmethyl, by the general formula (i) or (ii)) will be described as the and 1.5,9-trimethyldecyl. Second invention. In the Second invention, the cyclic ketals Examples of B-branched alkyls include 2-methylpropyl, 2-methylbutyl, 2-methylpenty 1, 2-ethylbutyl, and the cyclic acetals in the first invention are together 2-methylhexyl, 2-ethylpentyl, 2-methylheptyl, 2-ethylhexyl, referred to as “cyclic acetals.” and 2-propylpentyl. 25 Examples of B- and other polybranched alkyls having one (i) or more branches at positions other than C- and B-positions R5 R5 include 2,3-dimethylbutyl, 2,4,4-trimethylpentyl, and 2-isopropyl-5-methylhexyl. Examples of other branched alkyls having one or more /- veO branches at positions other than C- and B-positions include O 3-methylbutyl, 3-methylpentyl, 4-methylpenty1, 3,3- dimethylbutyl, 3-methylhexyl, 4-methylhexyl, R5 A- N O 5-methylhexyl, 3,5,5-trimethylhexyl, isodecyl, 3,7- R6 dimethyloctyl, and isoheptadecyl. (ii) Examples of alkyls having a tertiary carbon with no 35 hydrogen atom at C-position include 1,1-dimethylethyl, 1 - methylcyclopropyl, 1,1-dimethylpropyl, "SkO O 1-methylcyclobutyl, 1,1-dimethylbutyl, 1,1,2- trimethylpropyl, 1-methylcyclopentyl, 1,1-dimethylpentyl, O 1-methyl-1-ethylbutyl, 1,1-diethylpropyl, and 1,1- 40 diethylbutyl. Examples of alkyls having a tertiary carbon with no R-H O O hydrogen atom at B-position include 2,2-dimethylpropyl, R6 D< R6 2,2-dimethylbutyl, 1,2,2-trimethylpropyl, 1-ethyl-2,2- dimethylpropyl, 2,2-dimethylpentyl, and 2,3-dimethyl-2- isopropylbutyl. wherein R represents a hydrogen atom, and R represents 45 Examples of alkyls having a tertiary carbon at both C- and a branched alkyl with 3 carbon atoms or a linear or branched B-positions with no hydrogen atom at both C- and alkyl with 4-21 carbon atoms; or R represents a linear or B-positions include 1,1,2,2-tetramethylpropyl, 1,1,2,2- branched alkyl with 1-21 carbon atoms, and R represents tetramethylbutyl, and 1,1,2,2-tetramethylhexyl. a linear or branched alkyl with 2-21 carbon atoms. In formula (i) or (ii), when R represents a linear or Hexahydric alcohols which give the hexahydric alcohol 50 branched alkyl with 1-21 carbon atoms, R represents a residue in the compounds represented by the general for linear or branched alkyl with 2-21 carbon atoms. Preferably, mula (i) or (ii) include hexitols obtained by reduction of R is a linear or branched saturated alkyl with 1-12 carbon hexoses, Such as Sorbitol, mannitol, galactitol, iditol, talitol, atoms, and in this case, R is preferably a linear or branched and allitol. Saturated alkyl with 2-12 carbon atoms. From the view point of availability and cost, Sorbitol is the 55 In the above-mentioned case, examples of the linear or most preferable. branched alkyl with 1-21 carbon atoms represented by R In the general formula (i) or (ii), when R is a hydrogen include methyl, ethyl, propyl and isopropyl in addition to the atom, R is a branched alkyl with 3 carbon atoms, or a linear above-mentioned examples of linear or branched alkyls with or branched alkyl with 4-21 carbon atoms, preferably a 4-21 carbon atoms. branched Saturated alkyl with 3 carbon atoms or a linear or 60 Examples of the linear or branched alkyl with 2-21 branched Saturated alkyl with 4-12 carbon atoms, more carbon atoms represented by R include ethyl, propyl and preferably a branched saturated alkyl with 3-12 carbon isopropyl in addition to the above-mentioned examples of atOmS. linear or branched alkyls with 4-21 carbon atoms. The branched alkyl with 3 carbon atoms, represented by Specific examples (names and structures) of the cyclic R", is an isopropyl group. 65 acetals represented by the general formula (i) or (ii) as The linear or branched alkyls with 4-21 carbon atoms are mentioned above are listed below. However, they are not exemplified as below. limitative. 6,096,692 23 24 (1) 1.2:3.4:5.6-tri-O-(2-methylpropylidene)sorbitol (5) 1.2:3.4:5.6-tri-O-(1-methylpropylidene)sorbitol

O

(2) 13:24:5.6-tri-O-(2-methylpropylidene)sorbitol 5 (6) 13:24:5.6-tri-O-(1-methylpropylidene)sorbitol

D. 2O DC 3O (3) 1.2:3.4:5.6-tri-O-(3,5,5-trimethylhexylidene)sorbitol (7) 1.2:3.4:5.6-tri-O-(1,3-dimethylbutylidene)sorbitol

40 is

45 (4) 13:24:5.6-tri-O-(3,5,5-trimethylhexylidene)sorbitol (8) 13:24:5.6-tri-O-(1,3-dimethylbutylidene)sorbitol & 50 O O O r 60 O >

6,096,692 27 (17) 1.2:3.4:5.6-tri-O-(1-methylpropylidene)mannitol -continued R >< R5

O (ii)

R-H.R6 O >< OR6 1O wherein R and R are defined as the above; and R' represents a linear or branched alkyl having 1-6 carbon (18) 1.3:2.4:5.6-tri-O-(1-methylpropylidene)mannitol atOmS. In brief, the cyclic acetals represented by the general 15 formula (i) or (ii) are obtained by reacting a hexahydric alcohol Such as Sorbitol and mannitol represented by the general formula (iii) with a carbonyl compound Such as a ketone and an aldehyde represented by the general formula (iv) for dehydration, or with a reactive derivative thereof for dealcoholization, both in the presence of acid catalysts. When a ketone is used, compounds represented by the general formula (i) are predominant, and when an aldehyde is used, compounds represented by the general formulas (i) and (ii) are obtained as a mixture. Aldehydes with an 25 C.-branched alkyl group give a higher content of compound (i). Short reaction time leads to a higher content of com pound (ii). The hexahydric alcohols used are those represented by the The above cyclic acetals can suitably be produced by the above formula (iii), whose examples include hexitols method in the Second invention, but it is not limitative. obtained by reducing hexoses, Such as Sorbitol, mannitol, galactitol, iditol, talitol, and allitol. From the Viewpoint of availability and cost, Sorbitol is the most preferable. The cyclic acetals in the Second invention are useful as The carbonyl compounds used in the Second invention are polar oils, organic Solvents, lubricants, Synthetic lubricating ketones and aldehydes. Ketones are readily obtained by high oils, or refrigeration oils, or as intermediates in the produc 35 temperature decarboxylating dimerization of fatty acids, tion of Surfactants, organic Solvents, polar oils, Synthetic catalytic oxidation of olefins (Wacker process), oxidation or lubricating oils, and refrigeration oils. dehydrogenation of Secondary alcohols, and oxidation of cycloalkanes. Ketones obtained by Wacker process Show Next, the method for producing the cyclic acetals in the molecular weight distribution, but they can be separated and Second invention will be described. 40 purified by rectification. Examples of the ketones are as follows, but they are not limitative. The method of the present invention is characterized by Examples of methyl alkyl ketones include methyl ethyl reacting a hexahydric alcohol with a carbonyl compound ketone, methyl propyl ketone, methylbutyl ketone, methyl (ketone or aldehyde) or with a reactive derivative thereof amyl ketone, methyl hexyl ketone, methyl heptyl ketone, (ketal or acetal) in the presence of an acid catalyst. The 45 methyl octyl ketone, methyl nonyl ketone, methyl undecyl reaction Scheme of the relevant reactions is shown below. ketone, and methylheptadecyl ketone. Examples of dialkyl ketones include diethyl ketone, ethyl OH OH OH OH propyl ketone, ethyl butyl ketone, dipropyl ketone, ethyl pentyl ketone, ethylhexyl ketone, dibutyl ketone, dipentyl HO-CH-CH-CH-CH-CH-CH-OH -- 50 ketone, dihexyl ketone, diundecyl ketone, and diheptadecyl (iii) ketone. Examples of polybranched ketones include methyl iso RS RS OR7 propyl ketone, methyl Sec-butyl ketone, methyl isobutyl CFOo O N / HeH / / o 7 ketone, ethyl isopropyl ketone, methyl tert-butyl ketone, R6 R6 Yos H2O (or R'OH) 55 diisopropylketone, methyl isoamylketone, isopropyl propyl ketone, methyl neopentyl ketone, ethyl tert-butyl ketone, (iv) (iv) 6-methyl-2-heptanone, 4-methyl-3-heptanone, 2-methyl-3- R R5 R5 heptanone, 5-methyl-3-heptanone, diisobutyl ketone, and 6,10-dimethyl-2-undecanone. 60 Aldehydes used are those readily prepared by the follow ing methods: dehydrogenation of fatty alcohols, hydro formylation of olefins (oxo method), Rosenmund reduction of fatty acid chlorides, and direct hydrogenation of fatty acids. In the case of the OXO method, both linear and 65 branched aldehydes are produced, but they can be separated and purified by rectification. Examples of the alkyl alde hydes are mentioned below, but they are not limitative. 6,096,692 29 30 Examples of linear alkyl aldehydes include The above reaction may be carried out without solvents or Valeraldehyde, caproaldehyde, heptanal, octanal, decanal, in an inert Solvent, Such as Xylene, toluene, benzene, octane, dodecanal, tetradecanal, octadecanal, and behenaldehyde. isooctane, heptane, hexane, cyclohexane, pentane, butane, Examples of C.-branched alkyl aldehydes include ligroin, and petroleum ether, or in a mixture thereof. The is obutyraldehyde, 2-methylbutyraldehyde, reaction temperature depends upon the boiling point of the 2-methylpentanal, 2-ethylbutanal, 2-methylhexanal, 2-ethylpentanal, 2-methylheptanal, 2-ethylhexanal, and aldehyde used, and the reaction is normally carried out at a 2-propylpentanal. temperature of from 20 to 130 C., preferably from 40 to Examples of C- and other polybranched alkyl aldehydes 100 C., while removing the water formed during the having one or more branches at positions other than reaction. In the above temperature range, the reaction can C-position include 2,3-dimethylbutanal, 2,4,4- favorably proceed and coloration due to Side reactions is leSS trimethylpentanal, and 2-isopropyl-5-methylhexanal. likely to occur. Also, the reaction may be carried out in a Other examples of other branched alkyl aldehydes having nitrogen Stream, nitrogen atmosphere, or dry air. The reac one or more branches at positions other than C-position tion time varies with reaction conditions employed, but it is include iSo Vale raldehyde, 3-methylp ent anal, generally preferred to continue the reaction for 1 to 30 hours. 4-methylpentanal, 3,3-dimethylbutanal, 3-methylhexanal, 15 After neutralization, obtained cyclic acetals (i) or (ii) are 4-methylhexanal, 5-methylhexanal, 3.5,5-trimethylhexanal, Subjected to pretreatments, Such as filtration and washing. isodecylaldehyde, 3,7-dimethyloctanal, and isooctadecanal. Then, the cyclic acetals can be purified by Such means as Reactive derivatives of carbonyl compounds used in the adsorption, crystallization, and distillation. Second invention are ketals and acetals represented by The reaction between a hexahydric alcohol represented by formula (iv) which can readily be synthesized from a ketone formula (iii) and a ketal (iv), a reactive derivative of ketone, or an aldehyde mentioned above and a lower alcohol having is transketalization. The molar ratio of the ketal (iv) to the 1-6 carbon atoms in the presence of an acid catalyst. hexahydric alcohol represented by formula (iii) is in the Examples of lower alcohols having 1-6 carbon atoms which range of from 1.5 to 15, preferably from 2.7 to 7.5. This give R7 residue include methanol, ethanol, propanol, reaction is carried out in the presence of an acidic catalyst, isopropanol, butanol, isobutyl alcohol, Sec-butyl alcohol, 25 Such as p-toluenesulfonic acid, methaneSulfonic acid, and tert-butyl alcohol, amyl alcohol, isoamyl alcohol, neopentyl sulfuric acid, in an amount of 0.1 to 10 mole %, preferably alcohol, 1-methylbutanol, 1,1-dimethylpropanol, 1.0 to 5 mole % to the amount of the hexahydric alcohol 1-ethylpropanol, hexanol, isohexyl alcohol, 2-ethylbutanol, represented by formula (iii). 1-methyl-amyl alcohol, 1,3-dimethylbutanol, and The above reaction may be carried out without solvent, or 1-ethylbutanol. in an inert Solvent, Such as Xylene, toluene, benzene, octane, In the Second invention, the reaction between a hexahy isooctane, heptane, hexane, cyclohexane, pentane, ligroin, dric alcohol represented by formula (iii) and a ketone is and petroleum ether, or in a mixture thereof. Though the ketalization. The molar ratio of the ketone to the hexahydric reaction temperature depends upon the boiling points of the alcohol represented by formula (iii) is in the range of from ketal (iv) used and the lower alcohol formed, the reaction is 1.5 to 15, preferably from 2.7 to 7.5. This reaction is carried 35 carried out at a temperature of from 40 to 150° C., preferably out in the presence of an acidic catalyst, Such as from 70 to 130 C., while removing the lower alcohol p-tolueneSulfonic acid, methaneSulfonic acid, and Sulfuric formed. In the above temperature range, the reaction can acid in an amount of 0.1 to 10 mole %, preferably 1.0 to 5 favorably proceed and coloration due to Side reactions is leSS mole % to the amount of the hexahydric alcohol represented likely to occur. Also, the reaction may be carried out in a by formula (iii). 40 nitrogen Stream, nitrogen atmosphere, or dry air. The reac The above reaction may be carried out without any tion time varies with reaction conditions employed, but it is Solvents or in an inert Solvent, Such as Xylene, toluene, generally preferred to continue the reaction for 5 to 200 benzene, octane, isooctane, heptane, hexane, cyclohexane, hours. After neutralization, obtained cyclic ketals (i) or (ii) pentane, ligroin, and petroleum ether or in a mixture thereof. are Subjected to pretreatments, Such as filtration and wash The reaction temperature depends upon the boiling point of 45 ing. Then, the cyclic ketals can be purified by Such means as the ketone used, and the reaction is carried out at a tem adsorption, crystallization, and distillation. perature of from 30 to 130° C., preferably from 60 to 100° The reaction between a hexahydric alcohol represented by C., while removing the water formed during the reaction. In formula (iii) and an acetal (iv), a reactive derivative of the above temperature range, the reaction can favorably aldehyde, is transacetalization. The molar ratio of the acetal proceed and coloration due to Side reactions is less likely to 50 (iv) to the hexahydric alcohol represented by formula (iii) is occur. Also, the reaction may be carried out in a nitrogen in the range of from 1.5 to 6, preferably from 2.7 to 3.8. This Stream, nitrogen atmosphere, or dry air. The reaction time reaction is carried out in the presence of an acidic catalyst, varies with reaction conditions employed, but it is generally Such as p-toluenesulfonic acid, methaneSulfonic acid, and preferred to continue the reaction for 5 to 200 hours. After sulfuric acid, in an amount of 0.01 to 5 mole %, preferably neutralization, obtained cyclic ketals (i) or (ii) are Subjected 55 0.1 to 2 mole % to the amount of the hexahydric alcohol to pretreatments, Such as filtration and washing. Then, the represented by formula (iii). ketals can be purified by Such means as adsorption, The above reaction may be carried out without solvents, crystallization, and distillation. or in an inert Solvent, Such as Xylene, toluene, benzene, The reaction between a hexahydric alcohol represented by octane, isooctane, heptane, hexane, cyclohexane, pentane, formula (iii) and an aldehyde is acetalization. The molar 60 butane, ligroin, and petroleum ether, or in a mixture thereof. ratio of the aldehyde to the hexahydric alcohol represented The reaction temperature depends upon the boiling points of by formula (iii) is in the range of from 1.5 to 6, preferably the acetal (iv) used and the lower alcohol formed, and the from 2.7 to 3.8. This reaction is carried out in the presence reaction is normally carried out at a temperature of from 20 of an acidic catalyst, Such as p-toluenesulfonic acid, meth to 150° C., preferably from 50 to 130° C., while removing aneSulfonic acid, and Sulfuric acid, in an amount of 0.01 to 65 the lower alcohol formed. In the above temperature range, 5 mole %, preferably 0.1 to 2 mole % to the amount of the the reaction can favorably proceed and coloration due to Side hexahydric alcohol represented by formula (iii). reactions is less likely to occur. Also, the reaction may be 6,096,692 31 32 carried out in a nitrogen Stream, nitrogen atmosphere, or dry (0.049 mol, two times the equivalent of p-toluene Sulfonic air. The reaction time varies with reaction conditions acid) of sodium carbonate, and stirred at 60° C. for 30 employed, but it is generally preferred to continue the minutes. After 100 g of water was added to the mixture and reaction for 1 to 30 hours. After neutralization, obtained stirred at 60° C. for 30 minutes, the resulting mixture was cyclic acetals (i) or (ii) are Subjected to pretreatments, Such allowed to Stand to Separate into two layers. After the lower as filtration and washing, and then can be purified by Such layer was discarded, the upper layer was washed with 100 g means as adsorption, crystallization, and distillation. of Saturated brine, and evaporated with a rotary evaporator According to the production method in the Second under a reduced pressure to distill away petroleum ether and invention, when an aldehyde is used, a mixture of formulas excessive isobutyraldehyde. After further reduced-pressure (i) and (ii) is obtained, which can be separated by conven distillation, cyclic acetal B was obtained (hydroxyl value of tional methods for Separation and purification of organic 6.0 mgKOH/g, 99.0% purity as determined by gas compounds, Such as rectification, column chromatography, chromatography). thin layer chromatography, fractional crystallization, pre parative HPLC (liquid chromatography), and preparative PRODUCTION EXAMPLE 3 gas chromatography. However, Since physical properties of 15 A 3-liter four-necked flask was equipped with a Stirrer, a the both compounds are Similar, they can be directly used thermometer, a calcium chloride tube, and a dehydrating without Separation as a Synthetic lubricating oil, a refriger column with a condenser. In the flask, 450.0 g (2.47 mol) of ating oil, and the like. D-Sorbitol, 588.0 g (8.15 mol) of n-butyraldehyde, 4.7 g According to the production method in the Second (0.025 mol) of p-toluene sulfonic acid monohydrate, and invention, the above-mentioned cyclic acetals can be 400 ml of hexane were placed and heated at a temperature obtained by a simple method in high yield. of from 62 to 83° C. in a dry air atmosphere under atmo The present invention is hereinafter described in more spheric pressure for 5 hours with distilling off water. After detail by means of the following production examples, the completion of the reaction, the reaction mixture was working examples, Synthesis examples, and test examples, cooled to 60° C., neutralized by adding 5.24 g (0.049 mol, but is not limited by these examples. Production examples 25 two times the equivalent of p-toluene Sulfonic acid) of and working examples relate to the first invention, and Sodium carbonate, and stirred at 60° C. for 30 minutes. After Synthesis examples and test examples relate to the Second 100 g of water was added to the mixture and stirred at 60 invention. C. for 30 minutes, the resulting mixture was allowed to stand to Separate into two layers. After the lower layer was PRODUCTION EXAMPLE 1. discarded, the remaining upper layer was washed with 100 A 3-liter four-necked flask was equipped with a Stirrer, a g of Saturated brine, and evaporated with a rotary evaporator thermometer, a nitrogen inlet, and a dehydrating column under a reduced pressure to distill away hexane and exces with a condenser. In the flask, 336.8 g (1.85 mol) of sive n-butyraldehyde. After further reduced-pressure D-Sorbitol, 800.0 g (11.1 mol) of methyl ethyl ketone, 17.6 distillation, cyclic acetal C (hydroxyl value of 13.1 g (0.092 mol) of p-toluene Sulfonic acid monohydrate, and 35 mg KOH/g, 97.8% purity as determined by gas 200 ml of hexane were placed and heated at a temperature chromatography) was obtained. A part of the cyclic acetal C of from 69 to 79 C. in a nitrogen atmosphere for 8 hours was further purified by column chromatography to give with distilling off water. After the completion of the reaction, cyclic acetal C (hydroxyl value of 4.1 mgKOH/g, 99.3% the reaction mixture was cooled to 60° C., neutralized by purity as determined by gas chromatography). adding 19.6 g (0.185 mol, two times the equivalent of 40 p-toluene Sulfonic acid) of Sodium carbonate, and Stirred at PRODUCTION EXAMPLE 4 60° C. for 30 minutes. After 200 g of water was added to the mixture and stirred at 60° C. for 30 minutes, the resulting A 3-liter four-necked flask was equipped with a Stirrer, a mixture was allowed to Stand to Separate into two layers. thermometer, a calcium chloride tube, and a dehydrating After the lower layer was discarded, the upper layer was 45 column with a condenser. In the flask, 363.8 g (2.00 mol) of washed with 200 g of saturated brine, and evaporated with D-Sorbitol, 1200 g (12.0 mol) of methyl isobutyl ketone, a rotary evaporator under a reduced pressure to distill away 18.99 g (0.100 mol) of p-toluene sulfonic acid monohydrate, hexane and excessive methyl ethyl ketone. After further and 300 ml of hexane were placed and heated at a tempera reduced-pressure distillation, cyclic ketal A was obtained ture of from 93 to 98 C. in a dry air atmosphere under (hydroxyl value of 12.9 mgKOH/g, 97.3% purity as deter 50 atmospheric pressure for 23 hours with distilling off water. mined by gas chromatography). A part of the cyclic ketal A After the completion of the reaction, the reaction mixture was further purified by column chromatography to give was cooled to 60° C., neutralized by adding 21.16 g (0.200 cyclic ketal A (hydroxyl value of 0.0 mgKOH/g, 99.8% mol, two times the equivalent of p-toluene Sulfonic acid) of purity as determined by gas chromatography). Sodium carbonate, and stirred at 60° C. for 30 minutes. After 55 200 g of water was added to the mixture and stirred at 60 C. for 30 minutes, the resulting mixture was allowed to stand PRODUCTION EXAMPLE 2 to Separate into two layers. After the lower layer was A 3-liter four-necked flask was equipped with a Stirrer, a discarded, the remaining upper layer was washed with 200 thermometer, a calcium chloride tube, and a dehydrating g of Saturated brine, and evaporated with a rotary evaporator column with a condenser. In the flask, 450.0 g (2.47 mol) of 60 under a reduced pressure to distill away hexane and exces D-Sorbitol, 588.0 g (8.15 mol) of isobutyraldehyde, 4.7 g sive methyl isobutyl ketone, and further distill away low (0.025 mol) of p-toluene sulfonic acid monohydrate, and boiling point fractions under a reduced pressure. The 657.6 400 ml of petroleum ether with a boiling point of 30 to 60 g of crude ketal thus obtained was filtered through activated C. were placed and heated at a temperature of from 40 to 65 clay to give cyclic ketal D (hydroxyl value of 34.3 C. in a dry air atmosphere for 15 hours with distilling off 65 mg KOH/g, 93.1% purity as determined by gas water. After the completion of the reaction, the reaction chromatography) was obtained. A part of the cyclic ketal D mixture was cooled to 60° C., neutralized by adding 5.24g was further purified by column chromatography to give 6,096,692 33 34 cyclic ketal D (hydroxyl value of 0.0 mgKOH/g, 99.6% ture of from 110 to 119 C. in a nitrogen atmosphere under purity as determined by gas chromatography). atmospheric pressure for 55 hours with distilling off water. After the completion of the reaction, the reaction mixture PRODUCTION EXAMPLE 5 was cooled to 60° C., neutralized by adding 2.54 g (0.024 A 3-liter four-necked flask was equipped with a Stirrer, a mol, two times the equivalent of p-toluene Sulfonic acid) of thermometer, a calcium chloride tube, and a dehydrating Sodium carbonate, and stirred at 60° C. for 30 minutes. After column with a condenser. In the flask, 170.8 g (0.937 mol) 100 g of water was added to the mixture and stirred at 60 of D-Sorbitol, 400.0 g (2.81 mol) of 3.5.5-trimethylhexanal, C. for 30 minutes, the resulting mixture was allowed to stand 1.78 g (0.0094 mol) of p-toluene sulfonic acid monohydrate, to Separate into two layers. After the lower layer was and 400 ml of hexane were placed and heated at a tempera discarded, the remaining upper layer was washed with 50 g ture of from 79 to 81 C. in a dry air under atmospheric of Saturated brine, and evaporated with a rotary evaporator pressure for 8 hours with distilling off water. After the under a reduced preSSure to distill away toluene and exces completion of the reaction, the reaction mixture was cooled sive methyl isobutyl ketone, and further distillated under a to 70° C., neutralized by adding 1.99 g (0.019 mol, two reduced pressure to give cyclic ketal G (hydroxyl value of times the equivalent of p-toluene Sulfonic acid) of Sodium 15 26.2 mgKOH/g, 95.1% purity as determined by gas carbonate, and stirred at 70° C. for 30 minutes. After 100 g chromatography). A part of the cyclic ketal G was further of water was added to the mixture and stirred at 60° C. for purified by column chromatography to obtain cyclicketal G 30 minutes, the resulting mixture was allowed to Stand to (hydroxyl value of 1.6 mgKOH/g, 99.5% purity as deter Separate into two layers. After the lower layer was discarded, mined by gas chromatography). the remaining upper layer was washed with 100 g of Saturated brine, and evaporated with a rotary evaporator PRODUCTION EXAMPLE 8 under a reduced pressure to distill away hexane, and further A 3-liter four-necked flask was equipped with a Stirrer, a evaporated under a reduced pressure to distill away low thermometer, a calcium chloride tube, and a dehydrating boiling point fractions. To 500.9 g of the crude acetal column with a condenser. In the flask, 332.4 g (2.00 mol) of obtained, 500 ml of hexane was added, and the mixture was 25 diglycerol, 853.4 g (6.00 mol) of diisobutyl ketone, 7.61 g filtered through activated clay to give cyclic acetal E (0.040 mol) of p-toluene sulfonic acid monohydrate, and (hydroxyl value of 27.2 mgKOH/g, 93.2% purity as deter 500 ml of hexane were placed and heated at a temperature mined by gas chromatography) was obtained. of from 96 to 97 C. in a dry air atmosphere under atmo spheric pressure for 123 hours with distilling off water. After PRODUCTION EXAMPLE 6 the completion of the reaction, the reaction mixture was A 1-liter four-necked flask was equipped with a Stirrer, a cooled to 60° C., neutralized by adding 8.48 g (0.080 mol, thermometer, a nitrogen inlet tube, and a dehydrating col two times the equivalent of p-toluene Sulfonic acid) of umn with a condenser. In the flask, 166.0 g (1.00 mol) of Sodium carbonate, and stirred at 60° C. for 30 minutes. After diglycerol, 288.0 g (4.00 mol) of methyl ethyl ketone, 3.80 100 g of water was added to the mixture and stirred at 60 g (0.020 mol) of p-toluene Sulfonic acid monohydrate, and 35 C. for 30 minutes, the resulting mixture was allowed to stand 100 ml of hexane were placed and heated at a temperature to Separate into two layers. After the lower layer was of from 66 to 81 C. in a nitrogen atmosphere under discarded, the remaining upper layer was washed with 100 atomospheric pressure for 15 hours with distilling off water. g of Saturated brine, and evaporated with a rotary evaporator After the completion of the reaction, the reaction mixture 40 under a reduced pressure to distill away hexane, and further was cooled to 60° C., neutralized by adding 4.24 g (0.040 evaporated under a reduced pressure to distill away diisobu mol, two times the equivalent of p-toluene Sulfonic acid) of tyl ketone. To 666.7 g of the crude ketal obtained, 400 ml of Sodium carbonate, and stirred at 60° C. for 30 minutes. After hexane was added, and the mixture was filtered through 100 g of water was added to the mixture and stirred at 60 activated clay. The filtrate was evaporated with a rotary C. for 30 minutes, the resulting mixture was allowed to stand 45 evaporator under a reduced pressure to distill away hexane to Separate into two layers. After the lower layer was to give cyclic ketal H (hydroxyl value of 4.0 mgKOH/g, discarded, the remaining upper layer was washed with 100 98.0% purity as determined by gas chromatography). g of water, and evaporated with a rotary evaporator under a reduced pressure to distill away hexane, and excessive PRODUCTION EXAMPLE 9 methyl ethyl ketone and further evaporated under a reduced 50 A 1-liter four-necked flask was equipped with a Stirrer, a pressure to distill away low-boiling point fractions. To 223.0 thermometer, a nitrogen inlet, and a dehydrating column g of the crude ketal obtained, 0.6 g of activated alumina was with a condenser. In the flask, 166.0 g (1.00 mol) of added, and stirred at 50 C. for 30 minutes. After filtration, diglycerol, 289.7 g (2.04 mol) of 3.5.5-trimethylhexanal, cyclic ketal F (hydroxyl value of 15.7 mgKOH/g, 96.7% 1.90 g (0.010 mol) of p-toluene sulfonic acid monohydrate, purity as determined by gas chromatography) was obtained. 55 and 150 ml of hexane were placed and heated at a tempera A part of the cyclic ketal F was further purified by column ture of from 75 to 92 C. in a nitrogen atmosphere under chromatography to obtain cyclic ketal F (hydroxyl value of atmospheric pressure for 8 hours with distilling off water. 0.0 mg KOH, 99.7% purity as determined by gas After the completion of the reaction, the reaction mixture chromatography). was cooled to 60° C., neutralized by adding 2.12 g (0.020 60 mol, two times the equivalent of p-toluene Sulfonic acid) of PRODUCTION EXAMPLE 7 Sodium carbonate, and stirred at 60° C. for 30 minutes. After A 1-liter four-necked flask was equipped with a Stirrer, a 100 g of water was added to the mixture and stirred at 60 thermometer, a nitrogen inlet, and a dehydrating column C. for 30 minutes, the resulting mixture was allowed to stand with a condenser. In the flask, 100.0 g (0.602 mol) of to Separate into two layers. After the lower layer was diglycerol, 180.8 g (1.81 mol) of methyl isobutyl ketone, 65 discarded, the remaining upper layer was washed with 100 2.29 g (0.012 mol) of p-toluene sulfonic acid monohydrate, g of Saturated brine, evaporated with a rotary evaporator and 300 ml of toluene were placed and heated at a tempera under a reduced pressure to distill away hexane, and further 6,096,692 35 36 distillated under a reduced pressure to distill away low trimethylhexanal, 4.21 g (0.022 mol) of p-toluene Sulfonic boiling point fractions. To 405.5 g of the crude acetal acid monohydrate, and 600 ml of hexane were placed and obtained, 1.2 g of activated alumina was added, and Stirred heated at a temperature of from 76 to 83° C. in a dry air at 50 C. for 30 minutes. After filtration, cyclic acetal I under atmospheric pressure for 7 hours with distilling off (hydroxyl value of 23.1 mgKOH/g, 94.3% purity as deter water. After the completion of the reaction, the reaction mined by gas chromatography) was obtained. A part of the mixture was cooled to 60° C., neutralized by adding 4.68 g cyclic acetal I was further purified by column chromatog (0.044 mol, two times the equivalent of p-toluene Sulfonic raphy to obtain cyclic acetal I (hydroxyl value of 2.7 acid) of sodium carbonate, and stirred at 60° C. for 30 mg KOH/g, 99.1% purity as determined by gas minutes. After 100 g of water was added to the mixture and chromatography). stirred at 60° C. for 30 minutes, the resulting mixture was allowed to Stand to Separate into two layers. After the lower PRODUCTION EXAMPLE 10 layer was discarded, the remaining upper layer was washed A 1-liter four-necked flask was equipped with a Stirrer, a with 100 g of saturated brine, evaporated with a rotary thermometer, a nitrogen inlet, and a dehydrating column evaporator under a reduced preSSure to distill away hexane, with a condenser. In the flask, 100.0 g (0.602 mol) of 15 and further distillated under a reduced pressure to distill diglycerol, 205.0 g (1.20 mol) of 6-undecanone, 2.29 g away low-boiling point fractions. To 781.8 g of the crude (0.012 mol) of p-toluene sulfonic acid monohydrate, and acetal obtained, 400 ml of hexane was added, and the 300 ml of toluene were placed and heated at a temperature mixture was filtered through activated clay. The filtrate was of from 122 to 124 C. in a nitrogen atmosphere under evaporated with a rotary evaporator under a reduced pres atmospheric pressure for 48 hours with distilling off water. Sure to distill away hexane to give cyclic acetal L. (hydroxyl After the completion of the reaction, the reaction mixture value of 20.2 mgKOH/g, 95.3% purity as determined by gas was cooled to 60° C., neutralized by adding 2.54 g (0.024 chromatography). A part of the cyclic acetal L was further mol, two times the equivalent of p-toluene Sulfonic acid) of purified by column chromatography to obtain cyclic acetal Sodium carbonate, and stirred at 60° C. for 30 minutes. After L (hydroxyl value of 5.1 mgKOH/g, 98.0% purity as 100 g of water was added to the mixture and stirred at 60 25 determined by gas chromatography). C. for 30 minutes, the resulting mixture was allowed to stand to Separate into two layers. After the lower layer was PRODUCTION EXAMPLE 13 discarded, the remaining upper layer was washed with 50 g A 3-liter four-necked flask was equipped with a Stirrer, a of Saturated brine, evaporated with a rotary evaporator under thermometer, a nitrogen inlet, and a dehydrating column a reduced pressure to distill away toluene, and further with a condenser. In the flask, 336.8 g (1.85 mol) of distillated under a reduced pressure to give cyclic ketal J D-mannitol, 800.0 g (11.1 mol) of methyl ethyl ketone, 17.6 (hydroxyl value of 13.2 mgKOH/g, 96.5% purity as deter g (0.092 mol) of p-toluene sulfonic acid monohydrate, and mined by gas chromatography). A part of the cyclic ketal J 200 ml of hexane were placed and heated at a temperature was further purified by column chromatography to obtain of from 68 to 76° C. for 10 hours in a nitrogen atmosphere cyclic ketal J (hydroxyl value of 0.9 mgKOH/g, 99.0% 35 under atmospheric pressure with distilling off water. After purity as determined by gas chromatography). the completion of the reaction, the reaction mixture was cooled to 60° C., neutralized by adding 19.6 g (0.185 mol, PRODUCTION EXAMPLE 11 two times the equivalent of p-toluene Sulfonic acid) of A 1-liter four-necked flask was equipped with a Stirrer, a 40 Sodium carbonate, and stirred at 60° C. for 30 minutes. After thermometer, a nitrogen inlet, and a dehydrating column 200 g of water was added to the mixture and stirred at 60 with a condenser. In the flask, 122.0 g (1.00 mol) of C. for 30 minutes, the resulting mixture was allowed to stand meso-erythritol, 288.0 g (4.00 mol) of methyl ethyl ketone, to Separate into two layers. After the lower layer was 3.80 g (0.020 mol) of p-toluene sulfonic acid monohydrate, discarded, the remaining upper layer was washed with 200 g of Saturated brine, and evaporated with a rotary evaporator and 100 ml of hexane were placed and heated at a tempera 45 ture of from 63 to 78° C. in a nitrogen atmosphere under under a reduced pressure to distill away hexane and exces atmospheric pressure for 15 hours with distilling off water. Sive methyl ethyl ketone, further evaporated under a reduced After the completion of the reaction, the reaction mixture preSSure, and purified by column chromatography to give cyclic ketal M (hydroxyl value of 0.2 mgKOH/g, 99.6% was cooled to 60° C., neutralized by adding 4.24 g (0.040 purity as determined by gas chromatography). mol, two times the equivalent of p-toluene Sulfonic acid) of 50 Sodium carbonate, and stirred at 60° C. for 30 minutes. After 100 g of water was added to the mixture and stirred at 60 PRODUCTION EXAMPLE 1.4 C. for 30 minutes, the resulting mixture was allowed to stand A 3-liter four-necked flask was equipped with a Stirrer, a to Separate into two layers. After the lower layer was thermometer, and a dehydrating column with a condenser. In discarded, the remaining upper layer was washed with 100 55 the flask, 500 g (3.73 mol) of trimethylolpropane, 777 g g of water, evaporated with a rotary evaporator under a (7.46 mol) of 2,2-dimethoxy propane, 14.17 g (0.075 mol) reduced pressure to distill away hexane and excessive of p-toluene Sulfonic acid monohydrate were placed and methyl ethyl ketone, and further distillated under a reduced heated at a temperature of from 60 to 70° C. for 2 hours in pressure to give cyclic ketal K (hydroxyl value of 1.0 a nitrogen atmosphere under atmospheric pressure with mg KOH/g, 99.4% purity as determined by gas 60 distilling off methanol. After the completion of the reaction, chromatography). the reaction mixture was Subjected to the same post treatments as in Production Example 13 and then to a PRODUCTION EXAMPLE 12 reduced-pressure distillation to give 584.9 g of 1,3-dioxa A 3-liter four-necked flask was equipped with a Stirrer, a 5-ethyl-2,2-dimethyl-5-cyclohexylmethanol (Na) (90% thermometer, a calcium chloride tube, and a dehydrating 65 yield, hydroxyl value of 322.6 mgKOH/g). column with a condenser. In the flask, 270.0 g (2.21 mol) of A 2-liter four-necked flask was equipped with a Stirrer, a meso-erythritol, 629.0 g (4.42 mol) of 3,5,5- thermometer, a condenser, and a dropping funnel, and 6,096,692 37 38 purged with nitrogen gas. In the flask, 20.0 g (0.5 mol) of PRODUCTION EXAMPLE 1.5 sodium hydride (60% content, oily), 450 ml of 1,2- dimethoxyethane, and 150 ml of dimethylsulfoxide were In a 3-liter reaction vessel, 292.1 g (2.18 mol) of placed. Under a nitrogen atmosphere, 87.1 g (0.5 mol) of the trimethylolpropane, 474.0 g (8.17 mol) of acetone, 6.0 g compound (Na) obtained above was dropped over 15 min (0.0315 mol) of p-toluene sulfonic acid monohydrate, and utes at room temperature, and Stirred for further 1 hour. 900 ml of hexane were placed and refluxed for 24 hours with Then, 77.0 g (0.208 mol) of ethylene glycol di-p-tosylate removing the formed water off the reaction system. The powder (manufactured by Tokyo Kasei, K.K.) was added reaction product was neutralized with aqueous Solution of over 30 minutes. The mixture was stirred overnight at 70° C. Sodium hydroxide, and distilled under a reduced preSSure to under a nitrogen atmosphere, and 750 ml of water and 500 give 5-hydroxymethyl-5-ethyl-2,2-dimethyl-1,3-dioxane. ml of diethyl ether were added and allowed to separate into 2 layers. The aqueous layer was extracted twice with 300 ml Next, 17.4 g (0.1 mol) of the above 5-hydroxymethyl-5- of diethyl ether. The organic layer was combined with the ethyl-2,2-dimethyl-1,3-dioxane, 0.19 g (0.001 mol) of 28% ether extracts, and washed three times with 300 ml of 5% by weight sodium methylate methanol solution, and 5 ml of Sodium carbonate aqueous Solution, and dried over a mix 15 toluene were placed in a 500-milliliter stainless steel auto ture of anhydrous Sodium Sulfate and anhydrous Sodium clave (equipped with a stirrer, a liquid inlet tube, a gas outlet carbonate. Then, the solvent was distilled away with a rotary tube, and a thermometer), and the low-boiling point frac evaporator to give 115.3 g of oily Substance. This Substance tions were distilled away through the gas outlet tube by was purified by Silica gel column chromatography (hexane/ gradually reducing the pressure from atmospheric preSSure ethyl acetate, developing Solvent) to give 51 g of ethylene to a low pressure (0.4 mmHg) over 1 hour while heating at glycol di-1,3-dioxa-5-ethyl-2,2-dimethyl-5-cyclohexyl 110° C. After sealing, 58.0 g (1.0 mol) of propylene oxide methyl ether (Nb) (99% purity as determined by column was introduced into the autoclave through the liquid inlet chromatography, hydroxyl value of 0.0 mgKOH/g). tube by applying a pressure over 8 hours. After cooling, 21.2 A 1-liter four-necked flask was equipped with a Stirrer, a g (0.11 mol) of 28% by weight sodium methylate methanol thermometer, and a condenser. In the flask, 50 g (0.13 mol) 25 Solution and 150 ml of toluene were added to the reaction of the above compound (Nb), 500 ml of ethanol, and 50 ml product, and low-boiling point products were distilled away of 1N hydrochloric acid were placed and heated under reflux from the gas outlet tube by gradually reducing the preSSure at a temperature of from 80 to 100° C. in nitrogen atmo from atmospheric pressure to a low pressure (0.4 mmHg) Sphere for 5 hours. The reaction mixture was cooled to room over 2 hours with heating at 110° C. temperature, and neutralized with 1 N Sodium hydroxide. After cooling, 15.6 g (0.11 mol) of methyl iodide was The residue obtained by completely distilling off the solvent added and the autoclave was tightly Sealed, and heated at 60 under a reduced pressure was dissolved in water. After C. for 3 hours, and further heated at 90° C. for 5 hours. After electrodialysis, moisture was removed to give 37.6 g of cooling, 2.8 g of Kyoward 600 (alkali adsorber, manufac 2,9-diethyl-2,9-dihydroxymethyl-4,7-dioxadecane-1,10 tured by Kyowa Chemical Industry K.K.) was added, stirred diol (Nc). 35 for 1 hour, and filtered to give oil “fa’ used as a comparative A 300-milliliter four-necked flask was equipped with a product (78% purity as determined by gas chromatography). Stirrer, a thermometer, and a dehydrating column with a A part of “fa” was purified by column chromatography to condenser. In the flask, 37 g (0.13 mol) of compound (Nc) give an oil “f used as a comparative product (85% purity as obtained above, 28.1 g (0.39 mol) of methyl ethyl ketone, determined by gas chromatography). 0.49 g (0.0026 mol) of p-toluene sulfonic acid monohydrate, 40 and 50 g of hexane were placed and heated at a temperature EXAMPLE 1. of from 60 to 70° C. in a nitrogen atmosphere under atmospheric pressure for 8 hours with distilling off water. Hydroxyl values (JIS K-0070), percentages of unchanged After the completion of the reaction, the reaction mixture hydroxyls to the number of hydroxyls of a starting polyhy was Subjected to the same post-treatments as in Production 45 dric alcohol, which are calculated from the above hydroxyl Example 13, and the solvent was removed by a rotary value, kinematic viscosities at 40° C. and at 100° C. (JIS evaporator to give 52.3 g of an oily Substance. This Sub K-2283), and pour points (JIS K-2269) were determined for stance was purified by Silica gel column chromatography the cyclic ketals and cyclic acetals A to N obtained in (hexane/ethyl acetate developing Solvent) to give 45 g of Production Examples and used in the inventive products. ethylene glycol di-1,3-dioxa-2,5-diethyl-2-methyl-5- 50 The results are shown in Table 1. Also, kinematic viscosities cyclohexyl)methyl ether (cyclic ketal N)(98.5% purity as at 40° C. and at 100° C. (JIS K-2283) and pour points (JIS determined by column chromatography, hydroxyl value of K-2269) were determined for the oils “a” to “f” used in the 0.0 mgKOH/g). comparative products. The results are shown in Table 2.

TABLE 1. Cyclic ketals acetals Hydroxyl Unchanged Viscosity at Viscosity at Pour Starting value hydroxyls 40° C. 1OO C. point alcohols Starting ketones aldehydes (mgKOHg) (%) (mm/s) (mm/s) ( C.) A1 Sorbitol methyl ethyl ketone 12.9 1.3 66.9 4.62 -32.5 A2 Sorbitol methyl ethyl ketone O.O O.O 63.1 4.54 -32.5 B Sorbitol isobutyraldehyde 6.O O.61 167.8 5.81 -25.0 C Sorbitol n-butyraldehyde 13.1 1.3 68.2 5.49 -37.5 C2 Sorbitol n-butyraldehyde 4.1 O.42 65.6 S.42 -37.5 6,096,692 39 40

TABLE 1-continued Cyclic ketals acetals Hydroxyl Unchanged Viscosity at Viscosity at Pour Starting value hydroxyls 40° C. 1OO C. point alcohols Starting ketones aldehydes (mgKOHg) (%) (mm/s) (mm/s) ( C.) D Sorbitol methyl isobutyl ketone 34.3 4.2 62.3 5.61 -27.5 D Sorbitol methyl isobutyl ketone O.O O.O 53.9 5.36 -27.5 E Sorbitol 3,5,5-trimethylhexanal 27.2 4.3 394.6 15.5 -20.0> F. Diglycerol methyl ethyl ketone 15.7 1.9 7.69 1.97 -45.0> F. Diglycerol methyl ethyl ketone O.O O.O 6.82 1.87 -45.0> G Diglycerol methyl isobutyl ketone 26.2 3.8 9.08 2.35 -20.0> G Diglycerol methyl isobutyl ketone 1.6 O.24 7.83 216 -20.0> H Diglycerol disobutyl ketone 4.0 O.73 14.5 2.99 -20.0> I1. Diglycerol 3,5,5-trimethylhexanal 23.1 4.2 32.4 5.05 -45.0> I2 Diglycerol 3,5,5-trimethylhexanal 2.7 O.SO 29.5 4.94 -45.0> J1 Diglycerol 6-undecanone 13.2 2.7 32.7 5.16 -20.0> J2 Diglycerol 6-undecanone O.9 O.19 31.5 4.77 -20.0> K Erythritol methyl ethyl ketone 1.O O.10 3.99 1.26 -32.5 L1 Erythritol 3,5,5-trimethylhexanal 2O2 3.2 36.6 4.96 -37.5 L2 Erythritol 3,5,5-trimethylhexanal 5.1 O.84 37.7 5.05 -37.5 M Mannitol methyl ethyl ketone O.2 O.O2 35.2 3.63 -45.0

N Me X"XX O.O O.O 62.8 5.29 -20.0> X. Et Et O Et

TABLE 2 Viscosity at Viscosity at Pour 40° C. 1OO C. point Oils used in Comparative Products (mm/s) (mm/s) ( C.) a Naphthene oil 55.5 5.87 -40.0 (Nippon Sun Oil, Co. Ltd.: SUNISO 4GS) b Polyalkylene glycol 60.3 11.4 -40.0 (Sanyo Kasei Kogyo, Co. Ltd.: Newpol LB-285) Penta- 2-methylhexanoic acid C f 2-ethylpentanoic acid esters 30.9 5.21 -45.0> erythritol 2-ethylhexanoic acid Trimethylol 2-methylhexanoic acid d f 2-ethylpentanoic acid esters 31.4 5.31 -45.0> propane 3,5,5-trimethylhexanoic acid Penta- 2-ethylhexanoic acid e f esters 62.2 7.99 -45.0> erythritol 3,5,5-trimethylhexanoic acid f O octyoch 24.5 5.5 -45.0>

XX",O

50 EXAMPLE 2 (nephthene oil) with 1,1,1,2-tetrafluoroethane. The results Compatibility of each of the cyclic ketals and cyclic are shown in Table 3. acetals A to D, F to I, K, M, and N obtained in Production Examples and used in the inventive products with 1,1,1,2-tetrafluoroethane (HFC134a), or with a mixed 55 refrigerant of 1,1,1,2-tetrafluoroethane and difluoromethane (HFC32), or with a mixed refrigerant of 1,1,1,2- As obvious from Table 3, the inventive products exhibit tetrafluoroethane, difluoromethane, and pentafluoroethane good compatibility with hydrofluorocarbons at low tempera (HFC125) was evaluated. tures. Among the inventive products, the compositions con Low two-phase Separation temperatures were measured taining one of cyclic ketals and cyclic acetals A, A, B, D, for each of the inventive products 1 to 20, each of which was 60 D, F, F, G, K, and M are particularly good. AS obvious a composition of one of cyclic ketals and cyclic acetals A from the comparisons between cyclic ketals A and A to D, F to I, K, M, and N with one of 1,1,1,2- tetrafluoroethane (HFC134a), a mixed refrigerant of 1,1,1, (between inventive products 1 and 2), between D and D. 2-tetrafluoroethane and difluoromethane (HFC32), and a (between inventive products 6 and 7), and between cyclic mixed refrigerant of 1,1,1,2-tetrafluoroethane, difluo 65 acetals I and I (between inventive products 11 and 17), the romethane and pentafluoroethane (HFC125), and for com Smaller the number of unchanged hydroxyls is, the better parative product 1 which was a composition of oil “a” compatibility with hydrofluorocarbons is achieved. 6,096,692

TABLE 3 Two-phase separation temperature (C.) Composition Oil content % (by volume Oils Hydrofluorocarbon 1. 6 1O 2O 3O 40 50 Inventive 1 Cyclic ketal A. HFC134a -67 -55 -60 -67 -66 -68 -69 Products 2 Cyclic ketal A. HFC134a -70> -70s -70s -70s -70s 3 Cyclic ketal A HFC134a/HFC32 -70s -70s -57 -53 -54 -57 (70/30 weight ratio) 4 Cyclic acetal B HFC134a -70s -62 -44 -39 -39 -42 5 Cyclic acetal C, HFC134a 9 13 14 15 15 6 Cyclic ketal D, HFC134a -4 2 6 5.5 5 7 Cyclic ketal D, HFC134a -17 -1 5 4.5 2 8 Cyclic ketal F. HFC134a -70s -70s -70s -70s -70s -70s -70s 9 Cyclic ketal F. HFC134a/HFC32 -70> -70s -70s -70s -70s (70/30 weight ratio) 10 Cyclic ketal H HFC134a -10 13 16 13 4 11 Cyclic acetal I HFC134a -13 1O 14 11 -2 Comparative a (naphthene oil) HFC134a 2O& 2O& 20& 20& 2O& 2O& Product 1 Inventive 12 Cyclic ketal A HFC134a/HFC32AHFC125 -70s -70s -70s -70s -70s -70s -70s Products (52/23/25 weight ratio) 13 Cyclic ketal F, HFC134a -70s -70s -70s -70s -70s -70s -70s 14 Cyclic ketal F, HFC134a/HFC32 -70s -70s -70s -70s -70s -70s -70s (70/30 weight ratio) 15 Cyclic ketal F, HFC134a/HFC32AHFC125 -70s -70s -70s -70s -70s -70s -70s (52/23/25 weight ratio) 16 Cyclic ketal G. HFC134a -70s -70s -70s -70s -70s -70s -70s 17 Cyclic ketal I, HFC134a -19 9 12 9 3 18 Cyclic ketal K HFC134a -27 -2O -17 -15 -15 19 Cyclic ketal M HFC134a -46 -38 -30 -27 -28 20 Cyclic ketal N HFC134a -70> -70s -70s -70s -70s

EXAMPLE 3 Inventive product 2, a composition comprising cyclic TABLE 4 ketal A obtained in Production Example and used in the Volume inventive product with 1,1,1,2-tetrafluoroethane resistivity (HFC134a), was evaluated for compatibility at high tem- Oils (S2 cm) peratures. In an autoclave with inner volume of 372 cm Oils used Cyclic ketal A 1.7 x 101 having a sight glass, 60.0 g of cyclic ketal A and 240.0 g in Inventive Cyclic ketal A. 9.4 x o of HFC134a were weighed, the temperature was increased Products Cyclic ketal D, six 19. from room temperature to 100° C. withWiln appropriateiate Surring,Stirri 40 Cyclic ketal AD, 5.815 x 101310 and the State of Separation of the mixture was visually + Oil “b' used for checked. Comparative product (weight ratio of 50:50) Inventive product 2 (with an oil concentration of 20% by Cyclic acetal B 3.6 x 10 weight) maintained a state of uniform Solution from room is Cyclic acetal C. 1.7 x 10 temperature to 100° C., and showed no phase separation. R c i. X S.s Similarly, with 20.0 g of cyclic ketal A and 380.0 g of HFC & E. 13 0.14 134a, the State of separation WS observed. Inventive prod- Cyclic ketal k 8.9 x 10 uct2 (with an oil concentration of 5% by weight) maintained Cyclic acetal L2 7.8 x 10 a state of uniform solution from room temperature to 100 so Cyclicketal M 3.9 x 19, C. and showed no phase Separation Cyclic ketal N 5.4 x 10 •s p p Oils used b (Polyalkylene glycol) 7.8 x 10 Similarly, inventive product 2 with oil concentrations of in f 8.3 x 10'' 10% by weight, 30% by weight, 40% by weight, and 50% Strative by weight maintained a sate of uniform Solution from room temperature to 100 C., and did not show phase separation. 55 As is obvious from Table 4, the inventive products have EXAMPLE 4 high Volume resistivities, and better insulating property than the comparative products “b” and “f.” Also, the insulating Each of cyclic ketals A, A, B, C, D, D2, F2, I-2, J, K, property of polyalkylene glycol can be improved by blend L., M., and N obtained in Production Examples and used in 60 ing therewith a cyclic ketal or cyclic acetal used in the the inventive products, and oils “b” (polyalkylene glycol) inventive products. AS known from the comparison between and “f used in the comparative products were evaluated for cyclic ketals A and A and between D and D, the less the insulating property. Also, a mixture of cyclicketal A and oil number of unchanged hydroxyls is, the better insulating “b” used in the comparative product (weight ratio of 50:50) property is obtained. Also known from the comparison was similarly tested for insulating property. 65 between cyclic ketal A and cyclic acetals B and C, cyclic According to JIS C-2101, volume resistivity at 25°C. was ketal A obtained from a ketone has a better insulating measured. The results are shown in Table 4. property than cyclic acetal B or C obtained from an 6,096,692 43 44 aldehyde. NMR analysis and gas chromatography analysis 1,1,1,2-tetrafluoroethane (HFC134a). Also, inventive prod revealed that all cyclic ketal A are of IIIa structure, while uct 21, a composition of a mixture of cyclic ketal A and oil cyclic acetals B and C are mixtures of IIIa and IIIb structures “c” used in a comparative product (mixing ratio by weight with ratios (IIIa/IIIb) of 56/44 and 34/66, respectively. of 50:50) with 1,1,1,2-tetrafluoroethane (HFC134a), was Therefore, the more 1,3-dioxolan Structure is present, the tested in the Similar manner. better insulating property can be achieved. On the other hand, the insulating property of cyclic ketal N having two Specifically, 10 g of a lubricating oil adjusted to have a ether bonds in the moiety of polyhydric alcohol is poorer water content of 3000 ppm and an acid value of not more than that of cyclic ketals or cyclic acetals Ato M which have than 0.03 (mgKOH/g), and 5 g of hydrofluorocarbon were one or no ether bond in the moiety of polyhydric alcohol. placed in a glass tube; iron, copper, and aluminum were EXAMPLE 5 added thereto as catalysts, and the glass tube was Sealed. Each of the inventive products 1, 2, 3, 4, 7, 8, 12, 16, 18, After tested at 175 C. for 14 days, the composition of oil and 19 was subjected to the sealed tube test under the and hydrofluorocarbon was observed for its appearance and following conditions to examine thermal Stability, each 15 presence or absence of precipitation. After the hydrofluoro inventive product is a composition of one of cyclic ketals or carbon was removed, the acid value of the oil was measured. cyclic acetals A, A, B, D, F, G, K and M obtained in The results are shown in Table 6. Production Examples and used in the inventive products with one of 1,1,1,2-tetrafluoroethane (HFC134a), a mixed As is evident from Table 6, all of the inventive products refrigerant of 1,1,1,2-tetrafluoroethane and difluoromethane, have normal appearance, no precipitation, no increase in and a mixed refrigerant of 1,1,1,2-tetrafluoroethane, difluo acid value, and good thermal Stability in the presence of romethane and pentafluoroethane. water. As shown by inventive product 21, hydrolysis of an Specifically, 10 g of a lubricating oil adjusted to have a ester was prevented by adding cyclic ketals or cyclic acetals water content of not more than 10 ppm and an acid value of in the present invention to the ester. not more than 0.03 (mgKOH/g), and 5 g of hydrofluorocar 25 bon were placed in a glass tube, iron, copper, and aluminum TABLE 6 were added thereto as catalysts, and the glass tube was Physical Properties at the End of sealed. After tested at 175 C. for 14 days, the composition Experiment of hydrofluorocarbon and oil was observed for its appear ance and presence of precipitation. After the Sealed tube was Acid value opened to remove hydrofluorocarbon, the acid value of the Appearance Precipitation (mgKOHg) oil was measured. The results are shown in Table 5. Inventive 1. No change None O.O3> As is evident from Table 5, all of the inventive products Products 2 No change None O.O3> 3 No change None O.O3> have normal appearance, no precipitation, no increase in 35 4 No change None O.O3> acid value, and good thermal Stability. 7 No change None O.O3> 8 No change None O.O3> TABLE 5 12 No change None O.O3> 16 No change None O.O3> Physical Properties at the End of 18 No change None O.O3> Experiment 40 19 No change None O.O3> 21 No change None O.O3> Acid value Comparative 2 No change None 6.7 Appearance Precipitation (mgKOHg) Products 3 No change None 4.4 Inventive 1. No change None O.O3> Products 2 No change None O.O3> 45 3 No change None O.O3> 4 No change None O.O3> EXAMPLE 7 7 No change None O.O3> 8 No change None O.O3> 12 No change None O.O3> Each of inventive products 1 and 4 and comparative 16 No change None O.O3> 50 products 3 and 4 was Subjected to the FaleX test to examine 18 No change None O.O3> anti-abrasion property, each inventive product being a com 19 No change None O.O3> position of cyclic ketal or cyclic acetal A or B obtained in Productive Example and used in the inventive product with EXAMPLE 6 1,1,1,2-tetrafluoroethane (HFC134a), and each comparative 55 products being a composition of oil (ester) “d” or “e' used Each of inventive products 1, 2, 3, 4, 7, 8, 12, 16, 18, and in the comparative product with 1,1,1,2-tetrafluoroethane 19 and comparative products 2 and 3 was Subjected to the (HFC134a). Sealed tube test under the following conditions to examine the thermal Stability in the presence of water, each inventive 100 ml of each oil was heated up to 80 C., to which product being a composition of one of cyclic ketals and 60 1,1,1,2-tetrafluoroethane (HFC134a) was blown at 10 cyclic acetals A, A, B, D, F, G, K and M obtained in L/hour, and the pin was rotated under the load of 150 (1b) for Production Examples and used in the inventive products 4 hours, and the abrasion amount in the V block and the pin with one of 1,1,1,2-tetrafluoroethane (HFC134a), a mixed was determined. The results are shown in Table 7. refrigerant of 1,1,1,2-tetrafluoroethane and difluoromethane, and a mixed refrigerant of 1,1,1,2-tetrafluoroethane, difluo 65 As obvious from Table 7, the abrasion amount was very romethane and pentafluoroethane, and each comparative Small for all the inventive products, indicating a good product being a composition of oil “c” or “d” (ester) with anti-abrasion property. 6,096,692 46

TABLE 7 TABLE 9

Abrasion amount Abrasion of Adhesion to (mg) blade tip blade side faces Inventive Product 1 3.7 Oil A used in 5 tim None Inventive Product 4 1.5 Inventive Product Comparative Product 3 16.4 Oil A used in 5 tim None Comparative Product 4 8.1 Inventive Product Oile used in 20 tim Present 1O Comparative Product EXAMPLE 8 EXAMPLE 10 Hygroscopicity was evaluated for cyclic ketal A obtained in Production Example and used in the inventive product, Lubricity was evaluated by the Falex test for cyclic ketal and for oil “b” (polyalkylene glycol) and oil “c” (ester) used 15 A obtained in Production Example and used in the inven in the comparative products. tive product. Two grams of an oil adjusted in advance to have a water Cyclic ketal A was added to a low Sulfur gas oil content of not more than 50 ppm was weighed in a glass tube (S=0.04%) at 50 ppm, the operation was continued for 3 with an inner diameter of 18 mm and a content volume of 10 hours at 25°C. under a load of 150 (lb), and abrasion amount ml, which was then placed in a vessel at a constant tem in the V block and the pin after the operation was deter perature of 25 C. and a humidity of 80%. After a given mined. The results are shown in Table 10. period of time, the water content of the oil was determined As is evident from Table 10, inventive product 22 to by the Karl Fischer's method (JIS K-2275). The results are which cyclic ketal A was added showed a less amount of shown in Table 8. 25 abrasion than comparative product 5 to which cyclic ketal A was not added. Also, it showed a leSS amount of abrasion As is evident from Table 8, cyclicketal or cyclic acetal for as compared with the gas oil with sulfur content of 0.2% the inventive product has a Significantly low hygroscopicity, (comparative product 6), exhibiting good lubricity. which is almost comparable to an ester. TABLE 10 TABLE 8 Abrasion Water content (ppm amount (mg) Day 0 Day 1 Day 3 Day 6 Day 9 Inventive Low-sulfur gas oil (S = 0.04%) 2O.O Oil A used 45 1965 2,575 2,588 2,697 35 Product 22 + Cyclic ketal A, 50 ppm in Inventive Comparative Low-sulfur gas oil (S = 0.04%) 38.0 Product Product 5 Oil bused in 47 13,400 17,600 19,100 19,800 Comparative Gas Oil (0.2%) 24.8 Comparative Product 6 Product Oil c used in 23 1,352 1,742 1,780 1,779 40 Comparative Product EXAMPLE 11 Lubricity was evaluated by the Soda's pendulum test for cyclic ketal A obtained in Production Example and used in EXAMPLE 9 45 the inventive product. Cyclic ketal A was added to a low Sulfur gas oil A compressor test was performed with a commercially (S=0.04%) at 50 ppm, and determined the coefficient of available rotary compressor with respect to cyclic ketals. A friction at 25 C. The results are shown in Table 11. and A obtained in Production Examples and used in the As is evident from Table 11, inventive product 22 to inventive products, and oil 'e' (ester) used in the compara 50 which cyclic ketal A was added showed a Smaller value of tive product. coefficient of friction than comparative product 5 to which 170g of an oil adjusted in advance to have a water content cyclic ketal A was not added. Also, it showed a smaller of not more than 20 ppm and 60 g of 1,1,1,2- value of coefficient of friction as compared with the gas oil tetrafluoroethane (HFC 134a) were weighed in a rotary with sulfur content of 0.2% (comparative product 6), exhib compressor, and Subjected to continuous operation for 500 55 iting good lubricity. hours at a compressor shell temperature of 140 C. TABLE 11 After the 500-hour operation, cyclicketals A and A have leSS coloration than the oil 'e' for the comparative product, Coefficient of Friction no change in hydroxyl value, no decomposed or polymer 60 Inventive Product 22 O.164 ized products as analyzed by gas chromatography and gel Comparative Product 5 O.328 permeation chromatography, indicating good Stability of the Comparative Product 6 O.304 oil. Also, as shown in Table 9, cyclic ketals A and A showed leSS abrasion of sliding parts as compared with oil “e', indicating a better lubricity. Cyclic ketals A and A 65 EXAMPLE 12 provided a good condition, showing leSS Sludge adhesion to Dielectric constant at 25 C. was measured according to the discharge portion than oil 'e' for comparative product. JIS C-2101 to evaluate the insulating property of cyclic 6,096,692 47 48 ketals A, D, F., I, K, L, and M obtained in Production 9/1. The portions at Rf 0.6 to 0.7 as Compound (1) and at Rf Examples and used in the inventive products, and oil “b” 0.5 as Compound (2) were obtained in amounts of 0.63 g and (polyalkylene glycol) used in the comparative product. The 0.09 g, respectively. results are shown in Table 12. 'CNMR(CDC1, oppm) of Compound (1): 107.7-109.1 As is evident from Table 12, all the inventive products 5 indicates 5-membered acetal ring Structure. have low dielectric constants, showing good insulating 'CNMR(CDC1, oppm) of Compound (2): 107.7-109.1 property. and 104.9 indicate 5-membered and 6-membered acetal ring Also, cyclic ketals A, D, K and M, and cyclic acetal L, Structures, respectively (the intensity ratio of the peak at each having no ether bond, have lower dielectric constants 107.7-109.1 to the peak at 104.9 was 1:2). than cyclic ketal F and cyclic acetal I, each having one SYNTHESIS EXAMPLE 2 ether bond, indicating better insulating property. Synthesis of a mixture of 1.2:3.4:5.6-tri-O-(3,5,5- trimethylhexylidene)sorbitol (3) and 1.3:2.4:5.6-tri-O-(3.5, TABLE 12 5-trimethylhexylidene)sorbitol (4): Relative 15 In a 3-liter reaction vessel equipped with a thermometer, dielectric a reflux condenser, a Dean and Stark trap, a calcium chloride Oils constant tube, and a stirrer, 170.76 g (0.937 mol) of D-sorbitol, 400 Oils used in Cyclic ketal A 2.92 g (2.812 mol) of 3.5,5-trimethylhexanal, 1.78 g (0.00936 Inventive Cyclic ketal D, 2.78 mol) of p-toluene sulfonic acid monohydrate, and 400 ml of Products Cyclic ketal F, 3.47 hexane were placed. After the mixture was heated with Cyclic acetal I 3.22 stirring at a temperature of from 79 to 81 C. for 8 hours Cyclic ketal K 2.65 Cyclic acetal L2 2.50 while distilling off a theoretical amount of water. After the Cyclic ketal M 2.89 completion of the reaction, the reaction mixture was cooled Oils used in b (polyalkylene glycol) 5.31 to 70° C., neutralized by adding 1.99 g (0.0188 mol) of Comparative Sodium carbonate, and stirred at 70° C. for 30 minutes. After Product 25 100 g of water was added to the mixture and stirred at 60 C. for 30 minutes, the resulting mixture was allowed to stand to Separate into two layers. After the lower layer was SYNTHESIS EXAMPLE 1. discarded, the remaining upper layer was washed with 100 Synthesis of a mixture of 1.2:3.4:5.6-tri-O-(2- g of Saturated brine, and evaporated to give 529.51 g of the methylpropylidene)sorbitol (1) and 1.3:2.4:5.6-tri-O-(2- crude mixture of Compounds (3) and (4). The obtained methylpropylidene)sorbitol (2): product was Subjected to a reduced-pressure distillation and In a 3-liter reaction vessel equipped with a thermometer, a forerun (b.p. 27-85 C/0.5-0.9 mmHg) was discarded. a reflux condenser, a Dean and Stark trap, a calcium chloride 500.87 g of the residue was dissolved in 500 ml of hexane. tube, and a stirrer, 450 g (2.470 mol) of D-Sorbitol, 588 g The hexane Solution was Subjected to an adsorption treat (8.154 mol) of isobutyraldehyde, 4.70 g (0.0247 mol) of 35 ment by passing through 25.04 g (5% by weight to the p-toluene Sulfonic acid monohydrate, and 400 ml of petro residue) of activated clay on a filter (PTFE, 0.2 um) under leum ether (b. p. 30 to 60°C.) were placed. After the mixture preSSure. After washing the clay with hexane, the hexane was heated with stirring at a temperature of from 40 to 65 was completely distilled away from the hexane Solution to C. for 15 hours while distilling off a theoretical amount of give 501.14 g of a mixture of Compounds (3) and (4). water. After the completion of the reaction, the reaction 40 mixture was cooled to 60° C., neutralized by adding 5.24g Yield was 96.4%; purity as determined by gas (0.0494 mol) of sodium carbonate, and stirred at 60° C. for chromatography, 93.2% (the ratio of Compound (3)/ 30 minutes. After 100 g of water was added to the mixture Compound (4) is 31/69 (weight ratio)); and hydroxyl value, and stirred at 60° C. for 30 minutes, the resulting mixture 27.2 mgKOH/g (theoretical value 0). was allowed to Stand to Separate into two layers. After the 45 IR(NEAT, cm): 2960, 2908, 2876 (C-H stretching), lower layer was discarded, the remaining upper layer was 1476, 1414, 1396, 1368 (C-H deformation), 1132, 1098, washed with 100 g of Saturated brine, and evaporated to give 1042 (C-O-C stretching), 714 (CH rocking) 868.03 g of the crude mixture of Compounds (1) and (2). "H NMR(CDC1, oppm): The obtained product was Subjected to a reduced-pressure 0.77-1.40 (42H, multiplet, -CH(CH)CHC(CH)) distillation to give 800.17 g of a mixture of Compounds (1) 50 1.40-2.49 (9H, multiplet, -CHCH(CH)CHC(CH)) and (2). 3.38-3.68, 4.48-5.15 (3H, multiplet, (-O-)-CH-) Yield was 94.0%; b.p., 137 to 149 C./0.3 to 0.6 mmHg: 3.68–4.42 (8H, multiplet, -CHCHCHCHCHCH-) purity as determined by gas chromatography, 99.0% (the SYNTHESIS EXAMPLE 3 ratio of Compound (1)/Compound (2), 88/12(weight ratio)); Synthesis of 1.2:3.4:5.6-tri-O-(1-methylpropylidene) and hydroxyl value, 6.0 mgKOH/g (theoretical value 0). 55 sorbitol (5): Spectrum of the mixture of Compounds (1) and (2) In a 3-liter reaction vessel equipped with a thermometer, IR(NEAT, cm): 2972, 2936, 2884 (C-H stretching), a reflux condenser, a Dean and Stark trap, a nitrogen inlet 1476, 1406, 1368 (C-H deformation), 1194, 1106, 1038 tube, and a stirrer, 336.84 g (1849 mol) of D-Sorbitol, 800 (C-O-C stretching), 722 (CH rocking) g (11.094 mol) of methyl ethyl ketone, 17.58 g (0.092 mol) "H NMR(CDC1, 8ppm): 60 of p-toluene sulfonic acid monohydrate, and 200 ml of 0.58-1.49 (18H, multiplet, -CH) hexane were placed. After the mixture was heated with 1.53–2.13 (3H, multiplet, -CH(CH)) stirring at a temperature of from 69 to 79 C. for 8 hours 3.32-3.70, 4.50-4.97 (3H, multiplet, (-O-)-CH-) while distilling off a theoretical amount of water. After the 3.70-4.50 (8H, multiplet, -CHCHCHCHCHCH-) completion of the reaction, the reaction mixture was cooled With 1.0 g of the mixture of Compounds (1) and (2), a 65 to 60° C., neutralized by adding 19.60 g (0.185 mol) of preparative Silica gel thin layer chromatography was per Sodium carbonate, and stirred at 60° C. for 30 minutes. After formed using a developing Solvent of hexane/ethyl acetate= 200 g of water was added to the mixture and stirred at 60 6,096,692 49 SO C. for 30 minutes, the resulting mixture was allowed to stand Compound (7). The obtained crude Compound (7) was to Separate into two layers. After the lower layer was subjected to a reduced-pressure distillation (b.p. 30.5-141 discarded, the remaining upper layer was washed with 200 C/2-0.7 mmHg) and a forerun was discarded. 657.62 g of g of Saturated brine, and evaporated to give 643.75 g of the the residue obtained was Subjected to an adsorption treat crude Compound (5). The obtained product was subjected to ment by passing through 33 g (5% by weight to the residue) a reduced-pressure distillation to give 606.71 g of Com of activated clay on a filter (PTFE, 0.2 um) by a pressure pound (5). filtration. As a result, 637.44 g of Compound (7) was Yield was 95.3%; b.p., 136–140° C./0.6 mmHg; purity as obtained. determined by gas chromatography, 97.3%; and hydroxyl Yield was 74.5%; purity as determined by gas value 12.9 mgKOH/g (theoretical value 0). chromatography, 93.1%; and a hydroxyl value, 34.3 SYNTHESIS EXAMPLE 4 mgKOH/g (theoretical value:0). Synthesis of 1.2:3.4:5.6-tri-O-(1-methylpropylidene) SYNTHESIS EXAMPLE 6 sorbitol (5): Synthesis of 1.2:3.4:5.6-tri-O-(1,3-dimethylbutylidene) In a 2-liter reaction vessel equipped with a thermometer, sorbitol (7): a reflux condenser, a Dean and Stark trap, and a Stirrer, 168.4 15 In a 1-liter reaction vessel equipped with a thermometer, g (0.93 mol) of D-sorbitol, 400 g (5.6 mol) of methyl ethyl a reflux condenser, a Dean and Stark trap, a nitrogen inlet ketone, 8.8 g (0.046 mol) of p-toluene sulfonic acid tube, and a stirrer, 127.5 g (0.7 mol) of D-sorbitol, 420.7g monohydrate, and 100 g of hexane were placed. Under (4.2 mol) of methyl isobutyl ketone, 6.7 g (0.035 mol) of nitrogen atmosphere, the mixture was heated with Stirring at p-toluene Sulfonic acid monohydrate, and 100 g of toluene a temperature of from 65 to 72 C. for 7 hours while were placed. Under nitrogen atmosphere, the mixture was distilling off a theoretical amount of water. After the comple heated with Stirring and a dehydration reaction was carried tion of the reaction, the reaction mixture was cooled to 60 out at 92 C. under a reduced pressure for 8 hours. After the C., neutralized by adding 9.8 g (0.09 mol) of sodium completion of the reaction, the reaction mixture was cooled carbonate, and stirred at 60° C. for 30 minutes. After 100 g to 60° C., neutralized by adding 10.6 g (0.1 mol) of sodium of water was added to the mixture and stirred at 60° C. for 25 carbonate, and stirred at 60° C. for 30 minutes. After 60 g of 30 minutes, the resulting mixture was allowed to Stand to water was added to the mixture and stirred at 60° C. for 30 Separate into two layers. After the lower layer was discarded, minutes, the resulting mixture was allowed to Stand to the remaining upper layer was washed with Saturated brine Separate into two layers. After the lower layer was discarded, until it became neutral, dried over anhydrous Sodium Sulfate, the remaining upper layer was washed with Saturated brine and filtered. Hexane was distilled off from the filtrate to give until it became neutral and evaporated to distill off toluene 293.5g of crude Compound (5). to give 247.2 g of crude Compound (7). Yield of the crude compound was 92.2%; and hydroxyl Yield of the crude compound was 82.4%; and hydroxyl value, 18.0 mg KOH/g (theoretical value 0). value, 33.2 mg KOH/g (theoretical value 0). 100 g of the crude compound was dissolved in 100 ml of 100 g of the crude compound was dissolved in 100 ml of hexane, and purified by Silica gel column chromatography. 35 hexane, and purified by Silica gel column chromatography. Fractions eluted with hexane/ethyl acetate=8/2 were col Fractions eluted with hexane/ethyl acetate=8/2 were col lected and evaporated to give 95 g of Compound (5). lected and evaporated to give 90 g of Compound (7). Purity as determined by chromatography was 99.7%; and Purity as determined by chromatography was 99.4%; and hydroxyl value 0 mgKOH/g (theoretical value 0). hydroxyl value 0 mgKOH/g (theoretical value 0). IR(NEAT, cm): 2980, 2938, 2890 (C-H stretching), 40 IR(NEAT, cm): 2984, 2956, 2876 (C-H stretching), 1470, 1380 (C-H deformation), 1242, 1194, 1140, 1080 1470, 1378 (C–H deformation), 1242, 1186, 1148, 1096 (C-O-C stretching), 717 (CH rocking) (C-O-C stretching), 718 (CH rocking) "H NMR(CDC1, 8ppm): "H NMR(CDC1, oppm): 0.72-1.10 (9H, multiplet, -CHCH 0.78-1.10 (18H, multiplet, -CHCH(CH)) 1.10-1.48 (9H, multiplet, (-O-),C(CH)-) 45 1.22-1.47 (9H, multiplet, (-O-),C(CH)-) 1.48-1.90 (6H, multiplet, -CHCH) 1.47-1.68 (6H, multiplet, -CHCH(CH)) 3.71-4.31 (8H, multiplet, -CHCHCHCHCHCH-) 1.68-2.03 (3H, multiplet, -CH-CH(CH)) SYNTHESIS EXAMPLE 5 3.71-4.38 (8H, multiplet, -CHCHCHCHCH-) Synthesis of 1.2:3.4:5.6-tri-O-(1,3-dimethylbutylidene) 50 SYNTHESIS EXAMPLE 7 sorbitol (7): Synthesis of 1.2:3.4:5.6-tri-O-(1-methylpropylidene) In a 3-liter reaction vessel equipped with a thermometer, mannitol (17): a reflux condenser, a Dean and Stark trap, a calcium chloride In a 3-liter reaction vessel equipped with a thermometer, tube, and a stirrer, 363.76 g (1.997 mol) of D-sorbitol, 1200 a reflux condenser, a Dean and Stark trap, and a stirrer, g (11.981 mol) of methyl isobutyl ketone, 18.99 g (0.0998 55 336.84 g (1849 mol) of D-mannitol, 800.0 g (11.094 mol) mol) of p-toluene sulfonic acid monohydrate, and 300 ml of of methyl ethyl ketone, 17.58 g (0.092 mol) of p-toluene hexane were placed. The mixture was heated with Stirring at sulfonic acid monohydrate, and 200 ml of hexane were a temperature of from 93 to 98° C. for 23 hours while placed. Under nitrogen atmosphere, the mixture was heated distilling off a theoretical amount of water. After the comple with stirring at a temperature of from 68 to 76° C. for 10 tion of the reaction, the reaction mixture was cooled to 60 60 hours while distilling off a theoretical amount of water. After C., neutralized by adding 21.16 g (0.1996 mol) of sodium the completion of the reaction, the reaction mixture was carbonate, and stirred at 60° C. for 30 minutes. After 200 g cooled to 60° C., neutralized by adding 19.6 g (0.185 mol) of water was added to the mixture and stirred at 60° C. for of sodium carbonate, and stirred at 60° C. for 30 minutes. 30 minutes, the resulting mixture was allowed to Stand to After 200 g of water was added to the mixture and stirred at Separate into two layers. After the lower layer was discarded, 65 60° C. for 30 minutes, the resulting mixture was allowed to the remaining upper layer was washed with 200 g of Stand to Separate into two layers. After the lower layer was Saturated brine, and evaporated to give 736.65 g of crude discarded, the remaining upper layer was washed with 200 6,096,692 S1 52 g of Saturated brine, and evaporated to give 639.06 g of temperature for 1,1,1,2-tetrafluoroethane at low tempera crude Compound (17). The obtained crude Compound (17) tures was measured at oil concentrations of 10 vol%, 20 vol was Subjected to a reduced-pressure distillation to give %, 30 vol%, 40 vol%, and 50 vol%. The results are shown 605.76 g of partially purified Compound (17) (yield 95.1%). in Table 14. b.p. 136-140 C./0.3 mmHg; purity as determined by gas chromatography, 94.2%; and hydroxyl value, 12.7 TABLE 1.4 mgKOH/g (theoretical value 0). Kinematic viscosities at 40° C. and at 100° C. were 37.65 Two-phase separation at low mm°/s and 3.726 mm/s, respectively. temperatures (C. 150 g of the partially purified Compound (17) was dis 1O 2O 3O 40 50 solved in 150 ml of hexane, and purified by silica gel column Vo Vo Vo Vo Vol chromatography. Fractions eluted with hexane/ethyl Compounds % % % % % acetate=8/2 were collected and evaporated to give 135 g of Mixture of Inventive -62 -44 -39 -39 -42 Compound (17). Compounds (1) and (2) 15 (Synthesized according to Synthesis Purity as determined by chromatography, 99.6%; and Example 1) hydroxyl value 0.2 mgKOH/g (theoretical value 0). Inventive Compound (5) &-70 &-70 &-70 &-70 &-70 IR(NEAT, cm): 2986, 2944, 2890 (C-H stretching), (Synthesized according to Synthesis 1467, 1377 (C–H deformation), 1242, 1191, 1137, 1077 Example 4) Inventive Compound (7) -17 -1 5 4.5 2 (C-O-C stretching), 708 (CH rocking) (Synthesized according to Synthesis "H NMR(CDC1, 8ppm): Example 6) 0.72-1.13 (9H, multiplet, -CHCH Inventive Compound (17) -46 -38 -30 -27 -28 1.13-1.50 (9H, multiplet, (-O-),C(CH)-) (Synthesized according to Synthesis Example 7) 1.50-1.90 (6H, multiplet, -CHCH) Comparative Product 1 >2O >2O >2O >2O >2O 3.88-4.37 (8H, multiplet, -CHCHCHCHCHCH-) (naphthene oil: SUNISO 4GS 25 manufactured by Nippon Sun TEST EXAMPLE 1. Petroleum K.K.) Kinematic viscosities at 40° C. and at 100° C. (JIS K-2283), and pour point (JIS K-2269) were measured for the As is evident from Table 14, inventive products show cyclic acetals in the present invention obtained in Synthesis better compatibility than comparative products. Examples. The results are shown in Table 13. TEST EXAMPLE 3 TABLE 13 Volume resistivity at 25 C. was measured for cyclic Vis- Vis acetals in the present invention obtained in Synthesis cosity cosity 35 Examples and a comparative product (measured according at at Pour to JIS C-2101). The results are shown in Table 15. 40° C. 100° C. point Compounds (mm/s) (mm/s) ( C.) TABLE 1.5 Mixture of Inventive Compounds (1) and (2) 167.8 5.81 -25.0 (Synthesized according to Synthesis Volume Example 1) 40 Resistivity Mixture of Inventive Compounds (3) and (4) 394.6 15.5 <-20.0 Compounds (S2 cm) (Synthesized according to Synthesis Mixture of Inventive Compounds (1) and (2) 3.6 x 10' Example 2) (Synthesized according to Synthesis Inventive Compound (5) 63.1 4.54 -32.5 Example 1) (Synthesized according to Synthesis Inventive Compound (5) 9.4 x 10 Example 4) 45 (Synthesized according to Synthesis Inventive Compound (7) 53.9 5.36 -27.5 Example 4) (Synthesized according to Synthesis Inventive Compound (7) 5.8 x 101 Example 6) (Synthesized according to Synthesis Inventive Compound (17) 35.2 3.63 -45.0 Example 6) (Synthesized according to Synthesis Inventive Compound (17) 3.9 x 101 Example 7) 50 (Synthesized according to Synthesis Comparative Product 1 (naphthene oil: 55.5 5.87 -40.0 Example 7) SUNISO 4GS manufactured by Nippon Sun Comparative Product 2 (polyalkylene glycol 7.8 x 10 Petroleum K.K.) Comparative Product 2 (polyalkylene glycol: 60.3 11.4 -40.0 Newpol LB-285 manufactured by Sanyo Kasei Newpol LB-285 manufactured by Sanyo Kogyo K.K.) Kasei Kogyo K.K.) 55 Comparative Product 3 (2-methylhexanoic 31.4 5.31 &-45.0 acid, 2-ethylpentanoic acid, and 3.5.5- As is evident from Table 15, inventive compounds show trimethylhexanoic acid esters of tri better Volume resistivity than a comparative product. methylolpropane) Comparative Product 4 (2-ethylhexanoic 62.2 7.99 <-45.0 TEST EXAMPLE 4 acid and 3,5,5-trimethylhexanoic acid 60 Anti-abrasion effect was evaluated by the Falex test for esters of pentaerythritol) the composition of cyclic acetals in the present invention obtained in Synthesis Examples with 1,1,1,2- tetrafluoroethane (HFC134a) and the composition of an ester TEST EXAMPLE 2 of comparative products with 1,1,1,2-tetrafluoroethane Compatibility with 1,1,1,2-tetrafluoroethane (HFC134a) 65 (HFC134a). was measured for cyclic acetals in the present invention and 100 ml of the oil was heated to 80 C., into which comparative products. Specifically, the two-phase Separation 1,1,1,2-tetrafluoroethane (HFC134a) was blown at 10 6,096,692 S3 S4 L/hour. 4-hour operation was performed under a load of 150 -continued (1b). After the operation, abrasion amount in the V block and (IVa) the pin was evaluated. The results are shown in Table 16. R4 AS is evident from Table 16, the abrasion amount was 5 e - Small for all the inventive products, showing good anti O CH CH2 abrasion effect. YoH1 s y TABLE 16 O-C-R 1O I Abrasion R3 amount (IVb) Compounds (mg) R3 R4 Mixture of Inventive Compounds (1) and (2) 1.5 y ( (Synthesized according to Synthesis 15 Example 1) Inventive Compound (5) 3.7 ry (Synthesized according to Synthesis CH -CH2 Example 3) Comparative Product 3 (2-methylhexanoic acid, 16.4 fl. y 2-ethylpentanoic acid, and 3,5,5-trimethylhexa O O noic acid esters of trimethylolpropane) S. Comparative Product 4 (2-ethylhexanoic acid 8.1 R3 Y: and 3,5,5-trimethylhexanoic acid esters of pentaerythritol wherein R represents a hydrogen atom or a linear, 25 branched, or cyclic alkyl group having 1-12 carbon atoms, Industrial Applicability R" represents a linear, branched, or cyclic alkyl group The present invention provides a Synthetic lubricating oil having 1-12 carbon atoms, with the proviso that R and R' which shows a good thermal Stability, a good oxidation are not both methyl, or R and R together may represent an resistance, no formation of carboxylic acid due to hydrolysis alkylene group having 2-13 carbon atoms, a total carbon and a low hygroscopicity and is inexpensive as well. Also, atoms of R and R' being 1-13. the composition of the above lubricating oil with hydrof 2. A Synthetic lubricating oil comprising one or more luorocarbon can provide a working fluid composition for a cyclic ketals or cyclic acetals represented by the general refrigerating machine which shows a good insulating formula (V) or (VI): property, favorable hygroscopicity, and no formation of 35 carboxylic acid due to hydrolysis and is inexpensive as well. (V) Moreover, according to the present invention, novel cyclic R4 R3 acetals useful as Synthetic lubricating oils can be obtained in -l Y-n high yield and at high purity from inexpensive starting 40 R-i- -- materials. OYo?? CHYCH, O Not,-CH Schi, O What is claimed is: (VI) 1. A Synthetic lubricating oil comprising one or more R O-CH, CH, CH, CH, CHCH-O R cyclic ketals or cyclic acetals represented by the general V / V/ V/ formula (IIIa), (IIIb), (IVa), or (IVb): 45 R O-CH,/\ CH3 1'N,CH, /\ CH-C /\ R' (IIIa) R4 I wherein R represents a hydrogen atom or a linear, R3-C-O branched, or cyclic alkyl group having 1-12 carbon atoms, d h CH R" represents a linear, branched, or cyclic alkyl group Yot?/ st? CHNC 1-3YO having 1-12 carbon atoms, with the proviso that R and R' R-N4 \ 1-R are not both methyl, or R and R together may represent an A Nd O-CN 4 alkylene group having 2-13 carbon atoms, a total carbon R4 R 55 atoms of R and R' being 1-13. (IIIb) 3. A working fluid composition for a refrigerating R3 R4 machine comprising a refrigeration oil containing cyclic y ( ketals or cyclic acetals and a hydrofluorocarbon, wherein the 60 hydrofluorocarbon and the refrigerating oil are contained at ry hydrofluorocarbon/refrigerating oil (weight ratio) of 50/1 to CH CH 1/20, wherein Said cyclicketals or cyclic acetals are obtained f r H', by a reaction between one or more polyhydric alcohols O O O O having an even number of hydroxyl groups of not less than S. S. 65 4 and not more than 8 and one or more of Compound C or R3 Y. R3 Y. D, wherein the Compound C is a carbonyl compound represented by the general formula (II): 6,096,692 SS S6 -continued (II) (ii)

OSk O

O wherein R represents a hydrogen atom or a linear, R-HR6 O>< O branched, or cyclic alkyl group having 1-12 carbon atoms, R" represents a linear, branched, or cyclic alkyl group wherein having 1-12 carbon atoms; R and R' together may repre R represents a hydrogen atom, and R represents a Sent an alkylene group having 2-13 carbon atoms, a total branched alkyl group having 3 carbon atoms or a linear 15 or branched alkyl group having 4-21 carbon atoms, or carbon atoms of R and R' being 1-13, and wherein R represents a linear or branched alkyl group having Compound D is ketals or acetals obtained by a reaction 1-21 carbon atoms, and R represents a linear or between the carbonyl compound represented by the general branched alkyl group having 2-21 carbon atoms. formula (II) and a lower alcohol having 1-6 carbon atoms. 5. The cyclic acetals according to claim 4, wherein R represents a hydrogen atom, and R represents a branched alkyl group having 3 carbon atoms or a linear or branched 4. Cyclic acetals represented by the following general alkyl group having 4–12 carbon atoms; or R represents a linear or branched alkyl group having 1-12 carbon atoms, formula (i) or (ii): and R represents a linear or branched alkyl group having 2-12 carbon atoms. (i) 25 6. The cyclic acetals according to claim 4, wherein R represents a hydrogen atom, and R represents a branched R5 R5 alkyl group having 3–12 carbon atoms; or R represents a linear or branched alkyl group having 1-12 carbon atoms, /- veO and R represents a linear or branched alkyl group having 2-12 carbon atoms. O 7. The cyclic acetals according to any one of claims 4 to O 6, wherein a hexahydric alcohol residue is derived from A. N O Sorbitol.