US 20090239773A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2009/0239773 A1 Haramoto (43) Pub. Date: Sep. 24, 2009
(54) LUBRICANT ADDITIVE, LUBRICANT (86). PCT No.: PCT/UP2007/068O12 COMPOSITION AND GREASE COMPOSITION S371 (c)(1), (2), (4) Date: May 27, 2009 (75) Inventor: Yuhiro Haramoto, Yamanashi (30) Foreign Application Priority Data Sep. 15, 2006 (JP) ...... 2006-251.096 Correspondence Address: O O WESTERMAN, HATTORI, DANIELS & Publication Classification ADRIAN, LLP (51) Int. Cl. 1250 CONNECTICUT AVENUE, NW, SUITE 700 CIOM 33/40 (2006.01) WASHINGTON, DC 20036 (US) C07D 405/02 (2006.01) fu-sh (52) U.S. Cl...... 508/267: 546/282.4 73) Assignees: Yamanashi University, Kofu-shi, (73) 9. Yamanashi (JP); Af Co., Ltd., (57) ABSTRACT Ashiya-shi, Hyogo (JP); Nippon A lubricant additive comprising a rod-like liquid crystal com Chemical Industrial Co., Ltd., pound possessing a cation group and an anion is disclosed. Tokyo (JP) The rod-like liquid crystal compound is typically a specific type of 4-(1,3-diox-2-yl)pyridinium salt and exhibits an (21) Appl. No.: 12/441,419 effect of reducing the coefficient of friction ifadded in a small amount. A lubricant composition and a grease composition (22) PCT Filed: Sep. 10, 2007 comprising the lubricant additive are also disclosed.
METAL SURFACE Patent Application Publication Sep. 24, 2009 US 2009/0239773 A1
FIG 1
METAL SURFACE FIG 2
(EXAMPLE.3 (2)EXAMPLE 4 (3)COMPARATIVE EXAMPLE 1 O.1
OOS5
s
OOS va Y ... Y.Mar an (C85
FRICTION TIME (MIN) US 2009/0239773 A1 Sep. 24, 2009
LUBRICANT ADDITIVE, LUBRICANT form an intermolecular sequence in which the rod-like liquid COMPOSITION AND GREASE crystal compound possessing a cation group and an anion are COMPOSITION vertically oriented and exhibit metallic interface characteris tics differing from a general rod-like liquid crystal compound TECHNICAL FIELD and that (2) for this reason, the rod-like liquid crystal com pound possessing a cation group and an anion can exhibit, in 0001. The present invention relates to a lubricant additive, practice, an effective friction reducing effect even in a very and a lubricant composition and a grease composition con Small amount. These findings have led to the completion of taining the lubricant additive. the present invention. BACKGROUND ART 0006 Specifically, an invention (1) of the present inven tion provides a lubricant additive comprising a rod-like liquid 0002 Use of liquid crystals as an additive for lubricants crystal compound possessing a cation group and an anion. has been studied. For example, Patent Document 1 discloses 0007 An invention (2) provides the lubricant additive a method of simply changing a frictional force between two according to the invention (1) in which the cation group is a solid bodies by phase transfer of a thermotropic liquid crystal pyridinium group or an ammonium group. and the like introduced between the two bodies of relatively 0008. An invention (3) further provides the lubricant addi movable machine components. Patent Document 2 discloses tive according to the invention (1) or (2) in which the rod-like a lubricant composition comprising a base oil, a liquid crys liquid crystal compound is 4-(1,3-diox-2-yl)pyridinium salt tal, and a friction adjusting agent. Patent Document 3 dis type rod-like liquid crystal compound shown by the following closes a lubricant composition containing a liquid crystal formula (6): compound and a fluorinated oil. Patent Document 4 discloses a lubricant composition containing a base oil, an organic molybdenum compound, and a liquid crystal. The Patent (6) Documents 1 to 4 describe that the friction coefficient can be O reduced by adding a liquid crystal compound to a lubricant composition. (Patent Document 1).JP-A-2-503326 (claims) O v. (Patent Document 2) JP-A-6-128582 (claims) (Patent Document 3).JP-A-7-82582 (claims) wherein RandR indicate alkyl groups, alkoxyl groups, or a (Patent Document 4).JP-A-2004-182855 (claims) group having an unsaturated bond shown by the following 0003. In the methods of the Patent Documents 1 to 4, a formula (4), and X represents a halogen atom, practically useful effect of reducing the friction coefficient cannot be obtained unless the amount of the liquid crystal in the lubricant composition is 1% or more, and preferably 10% (4) or more. However, a liquid crystal compound is a very expen R3 sive material, whereas a lubricant composition must gener ally be available at a low cost. The addition of a liquid crystal CH=C-Z- in an amount of 1% or more to a lubricant composition is unprofitable. This is the reason why no lubricant containing a wherein R represents a hydrogen atom or a methyl group, Z liquid crystal compound is used in practice. There has been no indicates —(CH), , —(CH), O—, —CO-O-(CH2) lubricant composition containing an ionized liquid crystal , —CO-O-(CH), O—, —CH CH-O-, or compound. —CO—, wherein m is an integer of 1 to 30. 0004 An object of the present invention is to provide a 0009. An invention (4) provides the lubricant additive lubricant additive which can exhibit an effect of reducing the according to the invention (3), wherein R7 and R in the coefficient of friction when added in a small amount, and a formula (6) are alkyl groups. lubricant composition and a grease composition containing 0010. An invention (5) provides the lubricant additive the lubricant additive. according to the invention (4), wherein R7 in the formula (6) is an alkyl group having 8 to 22 carbon atoms and R is an DISCLOSURE OF THE INVENTION alkyl group having 1 to 4 carbon atoms. 0005. The inventor of the present invention has conducted 0011. An invention (6) provides a lubricant composition extensive studies in order to solve the above problems in comprising the lubricant additive according to any one of the general technologies. As a result, the inventor has found that inventions (1) to (5). (1) since a rod-like liquid crystal compound possessing a 0012. An invention (7) provides the lubricant composition cation group and an anion has a positive (+) portion and a according to the invention (6), wherein the content of the negative (-) portion of ions at the terminals, these positive and lubricant additive is 0.0001 to 0.1 mass %. negative portions are specifically coordinated on the interface 0013 An invention (8) provides a grease composition with a metal with ease and that the rod-like liquid crystal comprising the lubricant additive according to any one of the compound possessing a cation group and an anion forms a inventions (1) to (5). Smectic liquid crystal phase due to the powerful vertical 0014. An invention (9) provides the grease composition sequence and exists in a dark field when observed by a polar according to the invention (8), wherein the content of the ization microscope. The inventor has found that due to Such lubricant additive is 0.0001 to 0.1 mass %. characteristics, the positive (+) and negative (-) portions of 0015. An invention (10) provides a grease composition ions of the rod-like liquid crystal compound possessing a comprising the lubricant composition according to the inven cation group and an anion on the interface with a metal bond tion (6) or (7) and a thickener. US 2009/0239773 A1 Sep. 24, 2009
0016. The lubricant additive of the present invention can 0023 The cation group in the lubricant additive of the reduce the friction coefficient when added in a small amount. present invention is not particularly limited. Examples Since the lubricant additive of the present invention is an include a Sulfonium group, a phosphonium group, an ammo ionized liquid crystal compound, the boiling point of the nium group, a Serenonium group, an arsonium group, a sti lubricant composition is increased if the lubricant additive is bonium group, a stanonium group, an iodonium group, and a added in a small amount. Thus, the effects of controlling nitrogen-containing heterocyclic quaternary base. As the vaporization and lowering the coagulation temperature of the nitrogen-containing heterocyclic quaternary base, a pyri lubricant composition can also be expected. The lubricant dinium group, an imidazolium group, a thiozolium group, an composition and the grease composition containing the lubri Oxazolium group, a pyradinium group, a pyrimidinium group. cant additive of the present invention are useful for lubricat and the like can be given. The nitrogen-containing heterocy ing vehicle components such as continuously variable trans clic quaternary base may be substituted with a hetero atom missions, manual or automatic transmissions, engines, gears, Such as an oxygen atom and a Sulfur atom, and may form a and power steering, for lubricating internal combustion ring. Of these, the pyridinium group or the ammonium group engines, machine tools, and the like, and for lubricating is preferable. Although there are no particular limitations to motors and sliding parts of precision mechanical equipment the valence number of the cation group in the lubricant addi Such as a computer hard disk, information recording media tive of the present invention, a monovalent cation group is Such as a tape and a card, and a cellular phone. preferable. That is to say, as the rod-like liquid crystal com pound used as the lubricant additive of the present invention, BRIEF DESCRIPTION OF THE DRAWINGS a pyridinium salt or an ammonium salt is preferable. 0017 FIG. 1 shows the state of the lubricant additive of the 0024. There are no specific limitations to the anion in the present invention on a metal surface and FIG. 2 shows the lubricant additive of the present invention. Halogen ions such change of the friction coefficient over time in Example 3, as a chlorine ion, a bromine ion, and an iodine ion, anions of Example 4, and Comparative Example 1. organic acids, anions of inorganic acids, and the like can be given. Specific examples of the anions of organic acids BEST MODE FOR CARRYING OUT THE include anions of aliphatic monocarboxylic acids such as INVENTION formic acid, acetic acid, propionic acid, butyric acid, Valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic 0018. The lubricant additive of the present invention is a acid, capric acid, undecanoic acid, lauric acid, tridecanoic rod-like liquid crystal compound possessing a cation group acid, myristic acid, pentadecanoic acid, palmitic acid, hepta and an anion. Specifically, the lubricant additive of the decanoic acid, Stearic acid, nonadecanoic acid, arachidic present invention is a rod-like liquid crystal compound and acid, isobutyric acid, pivalic acid, isovaleric acid, isocaproic the rod-like liquid crystal compound has a cation group and acid, 2-ethylbutyric acid, 3.3-dimethylbutyric acid, isoca an anion in the molecule. prylic acid, 2-ethylhexanoic acid, isocapric acid, acrylic acid, 0019. The rod-like liquid crystal compound used as the methacrylic acid, crotonic acid, isocrotonic acid, 3-butenic lubricant additive of the present invention is a compound acid, pentenic acid, hexenic acid, heptenic acid, octenic acid, which forms a liquid crystal state and changes its state from nonenic acid, decenic acid, undecenic acid, dodecenic acid, Solid to crystal and crystal to liquid according to a tempera oleic acid, linolic acid, linoleic acid, elaidic acid, 2-methyl ture change (such a compound hereinafter referred to as a crotonic acid, 3-methylcrotonic acid, tiglic acid, cinnamic liquid crystal compound). A liquid crystal compound which acid, cyclopropanecarboxylic acid, cyclobutanecarboxylic changes its state from Solid to crystal and crystal to liquid acid, cyclopentanecarboxylic acid, cyclohexanecarboxylic according to a temperature change in this manner is also acid, trichloroacetic acid, tribromoacetic acid, trifluoroacetic called athermotropic liquid crystal. A liquid crystal means an acid, phenylacetic acid, glycolic acid, and lactic acid; ali anisotropic liquid which is fluid, is optically anisotropic, and phatic polyvalent carboxylic acids such as Oxalic acid, mal shows birefringence. The state of liquid crystal is between onic acid, Succinic acid, glutaric acid, adipic acid, pimelic liquid and crystal. acid, Suberic acid, azelaic acid, sebacic acid, dodecanoic 0020. There are mainly two types of liquid crystal com diacid, maleic acid, fumaric acid, citraconic acid, itaconic pounds which can form the state of liquid crystals. One is a acid, monomethyl maleic acid, malic acid, glutamic acid, compound which has a rod-like molecular shape called a tartaric acid, and citric acid; aromatic monocarboxylic acids calamitic liquid crystal and the other is a compound which has Such as benzoic acid, toluic acid, ethylbenzoic acid, propyl a disk-like molecular shape called a discotic liquid crystal. benzoic acid, butylbenzoic acid, hydroxybenzoic acid, anisic Among these, the rod-like liquid crystal compound used as acid, ethoxybenzoic acid, propoxybenzoic acid, butoxyben the lubricant additive of the present invention is a compound Zoic acid, aminobenzoic acid, N,N-dimethylaminobenzoic having a rod-like molecular shape called a calamitic liquid acid, nitrobenzoic acid, fluorobenzoic acid, resorcinic acid, crystal. and cinnamic acid; aromatic polyvalent carboxylic acids Such 0021. The rod-like liquid crystal compound used as the as phthalic acid, isophthalic acid, terephthalic acid, trimellitic lubricant additive of the present invention may be either a acid, trimesic acid, and pyromellitic acid; carbolic acids Such nematic liquid crystal or a Smectic liquid crystal. as phenol, o-phenylphenol, p-aminophenol, p-nitrophenol, 0022. The rod-like liquid crystal compound used as the catechol, resorcin, B-naphtol, and 2-chlorophenol. As specific lubricant additive in the present invention possesses a cation examples of the anion of inorganic acid, anions of Sulfuric group and a counter anion to the cation group in one mol acid, Sulfurous acid, amidosulfuric acid, methanesulfonic ecule. Specifically, the rod-like liquid crystal compound used acid, ethanesulfonic acid, propanesulfonic acid, butane as the lubricant additive in the present invention is a salt Sulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, having a cation group bonded to the molecule and an anion perchloric acid, periodic acid, ortho-periodic acid, perman bonded to the cation by an ionic bond. ganic acid, nitric acid, nitrous acid, phosphoric acid, phos US 2009/0239773 A1 Sep. 24, 2009 phorous acid, hypophosphorous acid, arsenic acid, arsenous represented by R' and R is a group shown by the following acid, boric acid, fluoroboric acid, hexafluorophosphoric acid, formula (5), hexafluoroantimonic acid, hexafluroroarsenic acid, chromic CH2O (5) acid, hydrochloric acid, chlorous acid, hypochloric acid, wherein p is preferably an integer of 1 to 30, and particularly Selenic acid, selenious acid, cyanic acid, thiocyanic acid, preferably 1 to 22. telluric acid, tellurious acid, silicic acid, silic hydrofluoric (0029. In the above formula (4) which shows R' and R in acid, hexafluorosilicic acid, polyphosphoric acid, meta-phos the formula (1), (2), or (3), R indicates a hydrogen atom or a phoric acid, molybdic acid, and the like can be given. Of methyl group, and Z indicates —(CH), , —(CH) - these, a chlorine ion, bromine ion, or iodine ion is preferable. O—, —CO-O-(CH2). , —CO-O-(CH2), O—, The valence number of the anion in the lubricant additive of CH-CH O—, or—CO—, wherein m is an integer of the present invention is equivalent to or Smaller than the 1 to 30, and preferably an integer of 1 to 22. number of Valence of the cation group. 0030. In the above formulas (1), (2), and (3), A indicates a 0025 Among the rod-like liquid crystal compounds used divalent group represented by the following formulas (A-1) to as the lubricant additive of the present invention, preferable (A-14). compounds include a pyridinium salt rod-like liquid crystal compound of the following formula (1), (A-1)
(1) e-Celti-e (A-2) a pyridinium salt rod-like liquid crystal compound of the (A-3) following formula (2), and
O in-chi ( )--8 (2) (A-4) (A-5) a pyridinium salt rod-like liquid crystal compound of the following formula (3). –O)-ch-ch (A-6) O (3) R4 ( ) C-O- (A-7) Ras-cis-e-r- O R6 O-C- 0026. In the above formula (1), formula (2), and formula ( ) (3), R and R may be either the same or different, and each (A-8) independently represents an alkyl group, analkoxyl group, or an unsaturated bond shown by the following formula (4). -()--- (A-9) O (4) R3 ( ) C-O- CH=C-Z- (A-10) 0027. The alkyl group represented by R' and R is a linear or branched alkyl group. The number of carbon atoms in the -( )—cio alkyl group represented by R' or R is preferably 1 to 30, and (A-11) particularly preferably 1 to 22. As specific examples of the all group represented by R' and R, a methyl group, an ethyl -( )-on group, a butyl group, a pentyl group, a hexyl group, an octyl (A-12) group, a dodecyl group, a pentadecyl group, and an octadecyl group can be given. 0028. The alkoxyl group represented by R' and R is a linear or branched alkoxyl group. A preferable alkoxyl group US 2009/0239773 A1 Sep. 24, 2009
0033. In the above formulas (2) and (3), n is an integer of -continued 0 to 20. R. RandR in the above formula (3) indicate alkyl (A-13) groups having 1 to 10 carbonatoms. X in the above formulas O (1) to (3) represents a halogen ion, and particularly preferably C-O- a chlorine ion, a bromine ion, or an iodine ion. -( )—K)- 0034 Among the rod-like liquid crystal compounds used (A-14) as the lubricant additive of the present invention, a particu larly preferable compound is the pyridinium salt rod-like liquid crystal compounds shown by the above formula (1). Among the pyridinium salt rod-like liquid crystal compounds shown by the above formula (1), a pyridinium salt rod-like liquid crystal compound in which A is a divalent group shown 0031. In the formula (A-14), t is an integer of 1 to 5. by the formula (A-3), that is, 4-(1,3-diox-2-yl)pyridinium salt 0032. In the above formulas (2) and (3), B indicates a rod-like liquid crystal compound shown by the following divalent group represented by the following formulas (B-1) to formula (6), is particularly preferable. (B-11). (6) O (B-1)
O v. (B-2) 0035. The 4-(1,3-diox-2-yl)pyridinium salt rod-like liquid crystal compound shown by the above formula (6) is herein after referred to from time to time as the pyridinium salt-type (B-3) rod-like liquid crystal compound shown by the above formula (6). 0036. In the above formula (6), R7 and R indicate alkyl O groups, alkoxyl groups, or a group having an unsaturated (B-4) bond shown by the above formula (4). RandR may be either O the same or different groups. C-O- 0037. The alkyl group represented by RandR is a linear ( ) or branched alkyl group. The number of carbon atoms in the (B-5) alkyl group represented by RandR is preferably 1 to 30, and O particularly preferably 1 to 22. As specific examples of the alkyl group represented by R and R, a methyl group, an ( ) O-C- ethyl group, a butyl group, a pentyl group, a hexyl group, an (B-6) octyl group, a dodecyl group, a pentadecyl group, and an O octadecyl group can be given. The alkoxyl group represented by R or R is a linear or branched alkoxyl group, preferably ( ) C-O- a linear or branched alkoxyl group shown by the above for (B-7) mula (5) in which p is an integer of 1 to 30, and particularly O preferably 1 to 22. The previous description of the group having the unsaturated bond represented by R' and R in the O-C- above formula (4) applies to the unsaturated bond represented ( ) by RandR in the above formula (4). (B-8) 0038 XT in the above formula (6) represents a halogen ion, and particularly preferably a chlorine ion, a bromine ion, or an iodine ion. (B-9) 0039. Among the pyridinium salt-type rod-like liquid crystal compounds shown by the above formula (6), pyri dinium salt-type rod-like liquid crystal compounds shown by -( )—cio the above formula (6) in which R" is an alkyl group are (B-10) preferable due to their excellent effect of reducing the coef ficient of friction. A pyridinium salt-type rod-like liquid crys tal compound having an alkyl group with 1 to 30 carbonatoms as R7 in the formula (6) is particularly preferable, a pyri (B-11) dinium salt-type rod-like liquid crystal compound having an alkyl group with 5 to 22 carbonatoms as R7 in the formula (6) is more preferable, and a pyridinium salt-type rod-like liquid crystal compound having an alkyl group with 8 to 22 carbon atoms as Randan alkyl group with 1 to 4 carbonatoms as R in the formula (6) is still more preferable. US 2009/0239773 A1 Sep. 24, 2009
0040. These rod-like liquid crystal compounds may be by the following reaction formula (18). R', R, X, A, B, and in used either individually or in combination of two or more as in the following formula (18) are the same as those in the the lubricant additive of the present invention. above formula (2). 0041. The pyridinium salt-type rod-like liquid crystal compounds shown by the formula (6) can be synthesized according to the reaction of the following reaction formula (18) (7), for example. R-A-B-(-CH-) -X + ()- -> (2) (7) COOR COOR (19) (20) R7-Y ". (9) R -- LiAlH4 0045. The ammonium salt-type rod-like liquid crystal COOR COOR compound shown by the above formula (3) can be obtained by reacting a halide (19) and a tertiary amine compound (22) as (8) (10) shown by the following reaction formula (21). R', R. R. R. / \ CHO X, A, B, and n in the following formula (21) are the same as those in the above formula (3). to: o R-- H (12) (21) CH2OH R5 (11) R-A-B-CH,--X + R*-N-R6 - (3) O (19) (22)
R-O O)-( o ) R8-X(14) 0046. The reactions in the above formulas (15), (18), and (13) (21) are commonly known reactions as described in WO O 2004/085398 and WO 2004/085380, for example. GE) O 0047. The lubricant composition of the present invention R7 -( O)-( o ) RSX comprises the lubricant additive of the present invention. That is, the composition comprises a rod-like liquid crystal com (6) pound possessing a cation group and an anion. 0048. The lubricant composition of the present invention 0042 First, a malonic ester (8) and a halide (9) are reacted is produced by adding the rod-like liquid crystal compound to obtain an R-introduced malonate (10), which is reduced possessing a cation group and an anion and various additives with LiAlH4 to obtainan R7-introduced 1,3-propanediol (11). which are optionally added to a lubricating base material. The R-introduced 1,3-propanediol (11) is then reacted with That is, the lubricant composition of the present invention pyridine-4-aldehyde (12) to obtain R-introduced 4-(1,3- comprises a lubricating base material and additives which diox-2-yl)pyridine (13). Next, the R7-introduced 4-(1,3-diox include the lubricant additive of the present invention as an 2-yl)pyridine (13) is reacted with a halide (14) to obtain a essential component. pyridinium salt-type rod-like liquid crystal compound shown 0049. Either one type of the lubricant additive of the by the above formula (6) (see, for example, JP-A-10-53585, present invention or a combination of two or more lubricant JP-A-2000-86723, JP-A-2000-86656, and “Liquid Crystals” additives of the present invention may be used in the lubricant Vol. 26, No. 10, pp 1425-1428 (1999)). R. R. and X in the composition of the present invention. formula (7) are the same as the R. R. and X in the formula 0050. The lubricating base material to which the lubricant (6), and Y indicates a halogen atom. additive of the present invention is added may be a mineral 0043. As shown in the following formula (15), the pyri oil, a synthetic oil, or a mixture of these. When the lubricant dinium salt-type rod-like-liquid crystal compound shown by composition of the present invention is an aqueous composi the above formula (1) can be obtained by reacting a pyridine tion, water may be used as a base material. compound (16) and a halide (17). R', R, X, and A in the 0051. There are no specific limitations to these lubricating following formula (15) are the same as those in the above base oils. Any materials, including mineral materials and formula (1). synthetic materials, commonly used as a lubricating base oil can be used without regard to their origin. Examples of the mineral lubricating base oils include paraffinic or naphthenic (15) hydrocarbon oils or mixtures of the hydrocarbon oils obtained from lubricating oil fractions of atmospheric or R-( ) + R2-X -- (1) vacuum distillation of a crude oil using various refining pro cesses such as solvent deasphalting, solvent extraction, (16) (17) hydrocracking, Solvent dewaxing, contact dewaxing, hydrofinishing, Sulfuric acid washing, and clay treatment, or 0044) The pyridinium salt-type rod-like liquid crystal a combination of these processes. As examples of the Syn compound shown by the above formula (2) can be obtained by thetic lubricating base oil, poly-C-olefin, polyesters such as reacting a halide (19) and a pyridine compound (20) as shown diester, polyol ester, and trimellitic acid ester, phosphate, US 2009/0239773 A1 Sep. 24, 2009 alkylbenzene and alkyl naphthalene, polyoxyalkylene glycol, 5 to 9 carbon atoms such as neopentylglycol (NPG), trim silicone oil, fluorine oil, alkyl phenyl ether oil, alkylbiphenyl ethylolpropane (TMP) or pentaerythritol (PE) with an oil, and polyphenyl ether oil can be given. organic acid having 4 to 18 carbonatoms. Specific examples 0052 Poly-C.-olefin used as the synthetic lubricating base of such a polyol ester include NPG.di-(heptanoate), NPG.di oil is a homopolymer or a copolymer of a branched or non (2-ethylbutylate), NPG.di-(cyclohexanoate), NPG.di-(hep branched olefin hydrocarbon having 2 to 14 carbon atoms, tanoate), NPG.di-(isoheptanoate), NPG.di-(octanoate), preferably 4 to 12 carbon atoms. The poly-C-olefin used as NPG.di-(2-ethylhexanoate), NPG.di-(isooctanoate), NPG. the synthetic lubricating base oil is preferably an oligomer di-(isononanoate), NPG.di-(isodecanoate), NPG.di-mixed having an average molecular weight from 100 to about 2000, (hexanoate, heptanoate), NPG.di-mixed(hexanoate, preferably from 200 to about 1000, in particular the oligomer octanoate), NPG.di-mixed(hexanoate, nonanoate), NPG. in which the unsaturated bonds are hydrogenated. As examples of preferable poly-C-olefins, polybutene, C.-olefin di-mixed(heptanoate, octanoate), NPG.di-mixed(hep oligomer, ethylene-C-olefin oligomer, 1-octene oligomer, tanoate, nonanoate), NPG.di-mixed(heptanoate, isooc and 1-decene oligomer can be given. As the polybutene, a tanoate), NPG.di-mixed(heptanoate, isononanoate), copolymer obtained by copolymerization of a monomer mix NPG.di-mixed (isooctanoate, isononanoate), NPG.di ture which contains isobutene, as a major component, and {mixed.(butanoate, tridecanoate), NPG.di-mixed.(bu butane-1 and butane-2, for example, is preferable. As tanoate, tetradecanoate), NPG.di-Mixed(butanoate, hexa examples of the C-olefin oligomer, a copolymer of C-olefins decanoate), NPG.di-mixed (butanoate, octadecanoate), having 6 to 12 carbon atoms which are obtained by thermal NPG.di-mixed(hexanoate, isooctanoate, isononanoate), cracking of hydrocarbons, or by trimerization, tetrameriza NPG.di-mixed(hexanoate, isooctanoate, isodecanoate), tion, pentamerization, or hexamerization of lower olefins can NPG.di-mixed(heptanoate, isooctanoate, isononanoate), be given. An oligomer obtained from a single monomer Such NPG.di-mixed(heptanoate, isooctanoate, isodecanoate), as decene is also preferable. NPG.di-mixed(octanoate, isononanoate, isodecanoate), 0053. The poly-C-olefin oligomers can be produced by TMP tri-(pentanoate), TMP tri-(hexanoate), TMP tri-(hep using a Friedel Crafts catalyst Such as aluminium chloride tanoate), TMP tri-(octanoate), TMP tri-(nonanoate), TMP tri and boron fluoride, a Ziegler catalyst, an oxide catalyst Such (isopentanoate), TMP tri-(2-ethylbutyrate), TMP tri-(isopen as chromium oxide, and the like. Hydrogenation of the poly tanoate), TMP tri-(isooctanoate), TMP tri-(2-ethyl C-olefin oligomers is carried out by causing the reaction hexanoate), TMP tri-(isononanoate), TMP tri-(isodecanoate), product from which the catalyst has been removed to come in TMP tri-mixed (butyrate, octadecanoate), TMP tri-mixed contact with a hydrogenation catalyst Such as a nickel-mo (hexanoate, hexadecanoate), TMP tri-mixed(heptanoate, lybdenum alumina catalyst while heating under pressure. tridecanoate), TMP tri-mixed (octanoate, decanoate), TMP. 0054 As the diester used as the synthetic lubricating base tri-mixed (octanoate, nonanoate), TMP tri-mixed (butyrate, oil, diesters obtained by reacting an aliphatic dibasic acid heptanoate, octadecanoate), TMP tri-mixed(pentanoate, having 4 to 14 carbon atoms or an aromatic dibasic acid with heptanoate, tridecanoate), TMP tri-mixed(hexanoate, hep an aliphatic alcohol having 4 to 14 carbonatoms can be given. tanoate, octanoate), TMP trinonanoate, TMP tri-mixed Examples of such diesters include dioctyl adipate, di-(1-eth (heptanoate, nonanoate), TMP tri-mixed(heptanoate, ylpropyl)adipate, di-(3-methylbutyl)adipate, di-(1,3-dimeth octanoate, nonanoate). PE. tetra(pentanoate), PE. tetra(hex ylbutyl)adipate, di-(2-ethylbutyl)adipate, di-(2-ethylhexyl) anoate), PE. tetra(isopentanoate), PE. tetra(2-ethylbutyrate), adipate, di-(isooctyl)adipate, di-(isononyl)adipate, di-(3.5.5- PE. tetra(heptanoate), PE. tetra(isoheptanoate), PE. tetra trimethylhexyl)adipate, di-(isodecyl)adipate, di-(undecyl) (isooctanoate), PE. tetra(2-ethylhexanoate), PE. tetra adipate, di-(tridecyl)adipate, di-(isotetradecyl)adipate, di-(2, (nonanoate), PE. tetra(isononanoate), and esters of PE and a 2,4-trimethylpentyl)adipate, di-mixed(2-ethylhexyl, linear of branched carboxylic acid having 4 to 9 carbonatoms. isononyl)adipate, di-(1-ethylpropyl)aZelate, di-(2-ethylbu 0056. The polyol esters used as the synthetic lubricating tyl)aZelate, di-(2-ethylhexyl)aZelate, di-(isooctyl)aZelate, di base oil also include polyol esters obtained by reacting a (isononyl)azelate, di-(35.5 trimethylhexyl)azelate, di-(iso neopentyl polyol other than NPG, TMP and PE such as decyl)azelate, di-(tridecyl)azelate, di-mixed(2-ethylhexyl, 2-methyl-2-propylpropane-1,3-diol. 2.2-diethylpropanediol. isononyl)aZelate, di-mixed(2-ethylhexyl, decyl)aZelate, trimethylolethane, and trimethylolhexane with an organic di-mixed(2-ethylhexyl, isodecyl)azelate, di-mixed(2-eth acid or a mixture of organic acids. ylhexyl, 2-propylheptyl)azelate, di-mixed(2-ethylhexyl, 0057. As the phosphate used as the synthetic lubricating decyl)aZelate, di-(n-butyl)sebacate, di-(isobutyl)sebacate, base oil, tricresyl phosphate, cresyldiphenyl phosphate, pro di-(1-ethylpropyl)sebacate, di-(3-methylbutyl)sebacate, di pylphenyl diphenyl phosphate, dipropylphenyl phenyl phos (1,3-dimethylbutyl)sebacate, di-(2-ethylbutyl)sebacate, di phate, tripropyl phosphate, dibutylphenyl phenyl phosphate, (2-ethylhexyl)sebacate, di-2-(2-ethylbutoxy)ethylseba butylphenyl diphenyl phosphate, tributylphenyl phosphate, cate, di-(2,2,4-trimethylpentyl)sebacate, di-(isononyl) tri-(2-ethylhexyl)phosphate, trialkylphenyl phosphate, and sebacate, di-(3.5.5-trimethylhexyl)sebacate, di-(isodecyl) alkylphenyl phenyl phosphate can be given. sebacate, di-(isoundecyl) sebacate, di-(tridecyl)sebacate, di 0058. The alkylbenzene or alkyl naphthalene used as the (isotetradecyl)sebacate, di-mixed(2-ethylhexyl, isononyl) synthetic lubricating base oil are oil components containing sebacate, di-(2-ethylhexyl)glutalate, di-(isoundecyl) dialkylated aromatic hydrocarbons as major components, glutalate, di-(isotetradecyl)glutalate, di-n-butyl phthalate, which are obtained by alkylating aromatic hydrocarbons such di-n-hexyl phthalate, di-n-heptyl phthalate, di-n-octyl phtha as benzene, toluene, or naphthalene with a branched or linear late, di-2-ethylhexyl phthalate, diisononyl phthalate, octylde C-olefin using a catalyst Such as hydrogen fluoride, Sulfuric cyl phthalate, diisodecyl phthalate, and ditridecyl phthalate. acid, or aluminium chloride. Either linear or branched alkyl 0055. The polyol ester used as the synthetic lubricating groups mainly having 12 carbon atoms can be used for the base oil can be obtained by reacting a neopentyl polyol having alkylation. US 2009/0239773 A1 Sep. 24, 2009
0059. The polyoxyalkylene glycol used as the synthetic alkanol amine salts of these esters can be given. Specific lubricating base oil is a ring-open polymer of a linear or examples of the phosphorous compounds used as the extreme branched alkylene oxide having 2 to 5, preferably 2 or 3 pressure additive or the wear inhibitor include phosphates carbon atoms in the alkylene group. As the alkylene oxide, Such as benzyl diphenylphosphate, allyl diphenylphosphate, ethylene oxide, propylene oxide, butylene oxide, or a mixture triphenyl phosphate, tricresyl phosphate, ethyl diphenyl of these, preferably propylene oxide is used. Accordingly, phosphate, tributyl phosphate, dibutyl phosphate, cresyl preferable polyoxyalkylene glycols are polyethylene glycol diphenyl phosphate, dicresyl phenyl phosphate, ethylphenyl and polypropylene glycol, having a molecular weight in a diphenyl phosphate, diethylphenyl phenyl phosphate, propy range of 100 to 2000, and preferably 200 to 1000. Polyoxy lphenyl diphenyl phosphate, dipropyl phenyl phenyl phos alkylene glycols having an alkyl group on both ends, and phate, triethyl phenyl phosphate, tripropyl phenyl phosphate, polyoxyalkylene glycols having an alkyl group on one end butylphenyl diphenyl phosphate, dibutylphenyl phenyl phos and a hydroxyl group on the other end are included. The phate, and tributyl phenyl phosphate; phosphite such as tri number of carbon atoms in the alkyl group is usually 1 to 18. isopropyl phosphite and diisopropyl phosphite; hexamethyl 0060. The lubricating base oil used in the present inven phosphoric triamide, n-butyl-n-dioctyl phosphinate, di-n-bu tion may be a mixture of two or more mineral lubricating base tylhexyl phosphonate, amine dibutyl phosphonate, and dibu oils, a mixture of two or more synthetic lubricating base oils, tyl phosphoroamidate. or a mixture of a mineral lubricating base oil and a synthetic 0066. As examples of the molybdenum compounds used lubricating base oil. The ratio of the two or more lubricating base oils may be arbitrarily selected. Although there are no as the extreme pressure additive or the wear inhibitor, inor particular limitations to the viscosity of the lubricating base ganic molybdenum compounds and organic molybdenum oil used in the lubricant composition of the present invention, compounds can be given. Specific examples of the inorganic the lubricating base oil has a kinematic viscosity at 40°C. of molybdenum compounds used as the extreme pressure addi tive or the wear inhibitor include metal molybdates such as preferably 1 to 1000 mm/s, and more preferably 5 to 800 Sodium molybdate, potassium molybdate, lithium molyb mm/s. date, magnesium molybdate, calcium molybdate, copper 0061 The content of the lubricant additive of the present molybdate, Zinc molybdate, and barium molybdate, and invention in the lubricant composition is 0.0001 to 0.1 mass molybdenum disulfide. As specific examples of the organic %, and preferably 0.0008 to 0.08 mass %. If the content of the molybdenum compounds used as the extreme pressure addi lubricant additive in the lubricant composition is less than tive or the wear inhibitor, molybdenum dialkyl dithiocarbam 0.0001 mass %, the effect of addition is too small for the ate (MoDTC), molybdenum dialkyl dithiophosphate lubricant composition to have a practical coefficient of fric (MoDTP), and molybdenum amine can be given. Of these, tion; if more than 0.1 mass %, on the other hand, the coeffi molybdenum dialkyl dithiocarbamate is preferable. Specific cient of friction tends to be excessively high. examples of the molybdenum dialkyldithiocarbamate include 0062. In addition to the lubricant additive of the present molybdenum dibutyldithiocarbamate sulfide, molybdenum invention, the lubricant composition may contain a friction dipentyldithiocarbamate sulfide, molybdenum dihexy conditioner Such as a wear inhibitor, an extreme pressure ldithiocarbamate sulfide, molybdenum diheptyldithiocar additive, and an oiliness agent, or other additives, as required. bamate sulfide, molybdenum dioctyldithiocarbamate sulfide, 0063 As examples of the extreme pressure additive and molybdenum dinonyldithiocarbamate sulfide, molybdenum the wear inhibitor, Sulfur compounds, phosphorus com didecyldithiocarbamate sulfide, molybdenum diunde pounds, and molybdenum compounds can be given. cyldithiocarbamate sulfide, molybdenum didodecyldithio 0064. As examples of the sulfur compounds used as the carbamate, molybdenum ditridecyldithiocarbamate, molyb extreme pressure additive or the wear inhibitor, disulfides, denum dibutyldithiocarbamate oxysulfide, molybdenum olefin sulfides, and sulfurated oils and fats can be given. More dipentyldithiocarbamate oxysulfide, molybdenum dihexy specific examples of the Sulfur compounds used as the ldithiocarbamate oxysulfide, molybdenum diheptyldithio extreme pressure additive or the wear inhibitor include a carbamate oxysulfide, molybdenum dioctyldithiocarbamate compound shown by the formula (RO)P—S (wherein R oxysulfide, molybdenum dinonyldithiocarbamate oxysul represents an alkyl group, an allyl group, or a phenyl group, fide, molybdenum didecyldithiocarbamate oxysulfide, and two or three Rs may be the same or different) such as trialkyl phosphorothionate, triphenylphosphorothionate, and molybdenum diundecyldithiocarbamate oxysulfide, molyb alkyl diallyl phosphorothionate; olefin sulfides shown by the denum didodecyldithiocarbamate oxysulfide, and molybde formula R Sx R' (whereinx indicates an integer of 1 to num ditridecyldithiocarbamate oxysulfide. 8, R and R' represents an alkyl group, alkenyl group, aryl 0067. The above sulfur compounds, Zinc dithiophos group, or aralkyl group having 4 to 12 carbon atoms) such as phates, phosphorus compounds, and molybdenum com disobutyl disulfide, dioctyl polysulfide, di-t-nonyl polysul pounds may be used either individually of in combination of fide, di-t-butyl polysulfide, dibenzyl polysulfide, diphenyl tWO Or more. sulfide, and diphenyl disulfide; sulfurated olefins obtained by 0068. As examples of the oiliness agents, aliphatic mono Sulfurizing olefins such as polyisobutylene or terpenes using carboxylic acids Such as caprylic acid, lauric acid, myristic a Sulfurizing agent such as Sulfur, Sulfurated oils and fats Such acid, palmitic acid, Stearic acid, and oleic acid; aliphatic as Sulfurated sperm oil and Sulfurated dipentene; thiocarbon dicarboxylic acids such as adipic acid, pimelic acid, Suberic ates Such as Xanthic disulfide; and Zinc dithiophosphate addi acid, azelaic acid, sebacic acid, undecanoic diacid, dode tives such as primary alkyl Zinc dithiophosphate, secondary canoic diacid, brassylic acid, tetradecanoic diacid, and other alkyl Zinc dithiophosphate, alkyl-allyl Zinc dithiophosphate, aliphatic dicarboxylic acids having 15 to 30 carbon atoms: and allyl Zinc dithiophosphate. esters of aliphatic (di)carboxylic acids, aliphatic alcohol, ali 0065. As examples of the phosphorous compounds used phatic amine, aliphatic amine salt, and fatty acid amides can as the extreme pressure additive or the wear inhibitor, phos be given. phoric acid monoesters, phosphoric acid diesters, phosphoric 0069. These oiliness agents may be used either individu acid triesters, phosphorous acid monoesters, phosphorous ally or in combination of two or more. The oiliness agents acid diesters, phosphorous acid triesters, and amine salts or adhere to the friction Surface of machines, and not only US 2009/0239773 A1 Sep. 24, 2009 improve friction and wear properties, but also promote lubric I0082. The thickener used in the grease composition of the ity by incorporation with the lubricant additive of the present present invention is not particularly limited. Any thickeners invention. which are used in general grease compositions may be used. 0070 The lubricant composition of the present invention I0083. In the grease composition of the present invention, a may further comprise other additives commonly used for mixture of the lubricating base oil used in the lubricant com lubricants such as an antioxidant, a metal detergent, an ash position of the present invention and the thickener is used as less dispersant, an anticorrosive agent, a corrosion inhibitor, a a base grease. As the thickener used in the grease composition Viscosity index improver, a pour point depressant, a rubber of the present invention, a Soap or a complex soap thickener, Swelling agent, a deformer, and a coloring agent. These addi an organic soap-free thickener Such as a terephthalamate tives may be added either alone or in combination of two or thickener, a urea thickener, polytetrafluoroethylene, and flu O. orinated ethylene-propylene copolymer, an inorganic Soap 0071. As the antioxidant, any antioxidants commonly free thickener, and the like can be given. These thickeners used for lubricants such as a phenolic antioxidant and an may be used either individually or in combination of two or amine antioxidant may be used. Specific examples includes more. Although not particularly limited, the thickeners may alkyl phenols such as 2,6-di-tert-butyl-4-methyl phenol; be used in an amount of preferably 3 to 40 mass %, and more bisphenols such as methylene-4,4-bis-(2,6-di-tert-butyl-4- preferably 5 to 20 mass % of the base grease which consists of methylphenol); naphthylamines Such as phenyl-C.-naphthy the lubricating base oil and the thickener. Although not par lamine; dialkyldiphenylamines; dialkyl Zinc dithiophosphate ticularly limited, the consistency of the base grease used in Such as di-2-ethylhexyl Zinc dithiophosphate; and phenothi the grease composition of the present invention is usually azines. about 100 to 500. 0072. As examples of the metal detergent, an alkaline I0084. The reason why the lubricant additive of the present earth metal Sulfonate, an alkaline earth metal phenate, an invention exhibits the effect of reducing the coefficient of alkaline earth metal salicylate, and an alkaline earth metal friction in an amount Smaller than that required for general phosphonate can be given. liquid crystal compounds is explained taking the case in 0073. As examples of the ashless dispersant, alkenyl suc which the pyridinium salt rod-like liquid crystal compound cinimido, benzylamine, alkyl polyamine, modified com obtained in Example 2 is added to a lubricant composition. As pounds of these ashless dispersants with a boron compound shown in FIG. 1, the pyridinium salt rod-like liquid crystal or a Sulfur compound, and alkenyl Succinates can be given. compound positively acts on the irregular Surface of metal, 0074 As examples of the anticorrosive agent, alkenyl suc which functions as one of the factors of increasing the coef cinic acid, alkenyl Succinate, polyhydric alcohol ester, petro ficient of friction. The molecules of the rod-like liquid crystal leum sulfonate, dinonyl naphthalene sulfonate, and the like compound efficiently form a membrane on the metal surface can be given. Vertically and regularly orientating to that Surface, thereby 0075. As examples of the corrosion inhibitor, benzotriaz efficiently reducing the coefficient offriction on the boundary ole compounds, thiadiazole compounds, imidazole com lubricating area. pounds, and the like can be given. I0085. The present invention will be described by way of 0076. As the viscosity index improver, either a non-dis examples, which are not intended to limit the present inven persant-type viscosity index improver or a dispersant-type tion. Viscosity index improver may be used. Specific examples include polymethacrylates, ethylene propylene copolymer, EXAMPLES polyisobutylene, polystyrene, and olefin copolymers such as Example 1 an styrene-diene copolymer can be given. 0077. As the pour point depressant, polymethacrylate Synthesis of diethyl-2-alkyl malonate (first step) polymers conforming to the lubricating base oil can be used. I0086 Diethyl-2-alkyl malonate (10a) was synthesized 0078. As examples of the defoaming agent, silicones such according to the following reaction. as dimethyl silicone and fluorosilicone can be given. 007.9 The amount of these commonly-used lubricant additives Such as an antioxidant, a metal detergent, an ashless dispersant, an anticorrosive agent, a corrosion inhibitor, a soon R7-Br soon Viscosity index improver, a pour point depressant, a rubber ". 9 R-i- Swelling agent, a deformer, and a coloring agent are arbi COOEt COOEt trarily determined. Usually, the amount of the defoamer is 0.0005 to 1 mass %, the amount of the viscosity index (8a) (10a) improver is 1 to 30 mass %, and the amount of the corrosion inhibitor is 0.005 to 1 mass %. Each of the other additives may wherein R represents n-CHs (Example 1) orn-CoH (Ex be added in an amount of about 0.1 to 15 mass %. ample 2). 0080. The grease composition of the present invention I0087. A 500 mlerlenmeyer flask was charged with 150 ml comprises the lubricant additive of the present invention. That of ethanol. After dissolving sodium metal (0.3 mol) in the is, the grease composition comprises a rod-like liquid crystal ethanol, diethyl malonate (8a) (0.3 mol) was added. After compound possessing a cation group and an anion. cooling, alkyl bromide (9a) (0.3 mol) was added. The mixture 0081. The grease composition of the present invention is was refluxed in an ethylene glycol bath at 30°C. for 18 hours. produced by mixing the lubricant composition, that is, the After removing the solvent by evaporation under reduced lubricant composition containing a rod-like liquid crystal pressure, diethyl ether (300 ml) was added and the mixture compound possessing a cation group and an anion, and a was washed with 300 ml of cold dilute hydrochloric acid thickener. Specifically, the grease composition of the present (hydrochloric acid: water 30 ml:300 ml) and 100 ml of cold invention consists of the lubricant composition, which con distilled water in a separating funnel. The ether layer was tains the lubricant additive of the present invention, and a collected and the water layer was extracted again with 100 ml thickener. of diethyl ether. The diethyl ether solution obtained by liquid US 2009/0239773 A1 Sep. 24, 2009
separation was dehydrated with anhydrous sodium sulfate for 0092 A Dean Stark trap was used as a reactor. A 100 ml about one day. After filtration, diethyl ether was removed erlenmeyer flask was charged with benzene (60 ml) and under reduced pressure, and the residue was distilled under 2-alkyl-1,3-propanediol (11a) (0.03 mol), and pyridine-4- reduced pressure to obtain diethyl-2-alkyl malonate (10a). aldehyde (equivalent moles) was dissolved therein. 10 g of p-toluenesulfonic acid was added to reduce the pH to 1 or less. Synthesis of 2-alkyl-1,3-propanediol (second step) After confirming the pH, the erlenmeyer flask was installed 0088 2-alkyl-1,3-propanediol (11a) was synthesized on the Dean Stark trap to reflux the content in a silicone bath according to the following reaction. at 135 to 140°C. for five hours. After cooling, the reaction product was dissolved in diethyl ether (300 ml), washed with a sodium carbonate aqueous solution (30 g/300 ml) and, after confirming that the aqueous Solution was basic, washed with soon got distilled water (100 ml) to obtain a diethyl ether layer. The R-- LiAlH4 R-- diethyl ether layer was dehydrated with anhydrous sodium COOEt CHOH sulfate for about one day. After filtration, diethyl ether was (10a) (11a) removed under reduced pressure. The residue was purified by column chromatography using silica gel, to which 300 ml of I0089 wherein R represents n-C, His (Example 1) or hexane was first fed and then 300 ml of benzene was fed. The n-CoH (Example 2). target compound was eluted in a benzene solvent. After 0090. A 500 ml round-bottom erlenmeyer flask was removing the solvent, the residue was purified by recrystalli charged with 100 ml of diethyl ether and lithium aluminum Zation three or four times from special grade hexane to obtain hydride (twice the number of moles). Then, diethyl-2-alkyl 4-(5-alkyl-1,3-diox-2-yl)pyridine (13a). malonate (10a) (0.23 mol) obtained in the first step dissolved in 100 ml of diethyl ether was slowly added using a dropping funnel while cooling with ice. The resulting mixture was Synthesis of N-alkyl-4-(5-alkyl-1,3-diox-2-yl)pyri refluxed at 40° C. for four hours in an ethylene glycol bath. dinium bromide (fourth step) After the reaction, a solution of ethyl acetate (0.3 mol) in 100 ml of diethyl ether was slowly added using a dropping funnel 0093 N-alkyl-4-(5-alkyl-1,3-diox-2-yl)pyridinium bro while cooling with ice. Next, 50 ml of a saturated ammonium mide (6a) was synthesized according to the following reac aqueous solution was slowly added drop by drop using a tion. dropping funnel. After that, the flask was filled with diethyl ether and the contents were stirred at room temperature (25° C.) for three hours. The resulting product was filtered and the O R-Br residue was dissolved in 300 ml of diethyl ether. The solution was stirred for 24 hours. After dehydrating with anhydrous R-( / \, . sodium sulfate for about one day, diethyl ether was evapo O o rated under reduced pressure to obtain 2-alkyl-1,3-pro panediol (11a) as a residue. Synthesis of 4-(5-alkyl-1,3-diox-2-yl)pyridine (third step) O 0091 4-(5-alkyl-1,3-diox-2-yl)pyridine (13a) was synthe GE) O sized according to the following reaction. R-O O)-( o ) is (6a)
/ \ CHO wherein R represents n-C, His (Example 1) orn-CoH (Ex CHOH o ample 2) and R represents C.H. (Example 1, Example 2). R-- (12) 0094. In a 200 ml round-bottom erlenmeyer flask, the 4-(5-alkyl-1,3-diox-2-yl)pyridine (13a) (0.0017 mol) CH2OH obtained in the third step and ethyl bromide (10 times mol) (11a) were dissolved in 30 ml of special grade acetonitrile and the solution was refluxed at 100° C. for 24 hours on a silicone bath in a nitrogen stream. After removing acetonitrile under reduced pressure, the residue was purified by recrystallization O from a mixed solvent of 30 ml of hexane and 30 ml of diethyl ether, followed by washing while stirring for about one day to -O-(O o ) obtain undissolved components, which were dried under vacuum to obtain N-alkyl-4-(5-alkyl-1,3-diox-2-yl)pyri (13a) dinium bromide (6a). The results of 'H-NMR analysis and IR analysis of the N-alkyl-4-(5-alkyl-1,3-diox-2-yl)pyridinium wherein R represents n-CHs (Example 1) orn-CoH (Ex bromide (6a) are shown in Table 1 and the results of the phase ample 2). transition temperature measurement are shown in Table 2. US 2009/0239773 A1 Sep. 24, 2009 10
TABLE 1.
Formula (6a) Identification data Example 1 R"—CH (1) H-NMR (CDC1, 8): 0.85-1.83 (m, 19H), 3.37-4.38 R—CHs (m, 4H), 5.07 (q, 2H, Jab = 6.70 Hz), 5.48 (s, 1H), 8.08 (d, 2H, Jcd = 6.40 Hz), 9.75 (d. 2H, Jcd = 6.40 Hz) (2) FT-IR (CHCl, cm - 1); 2920, 2840 (C-H stretching vibration), 1650 (C–C, C=N stretching vibration), 1085 (C-O-C stretching vibration), 890 (pyridine ring C–H out-of-plane bending vibration) Example 2 R—CoH (1) H-NMR (CDC1, 8): 0.87-1.85 (m, 25H), 3.38-440, R—CHs (m, 4H), 5.12 (q, 2H, Jab = 6.70 Hz), 5.58 (s, 1H), 8.12 (d 2H, Jcd = 6.40 Hz), 9.78 (d. 2H, Jcd = 6.40 Hz) (2) FT-IR (CHCl, cm); 2925, 2870 (C-H stretching vibration), 1655 (C–C, C=N stretching vibration), 1095 (C-O-C stretching vibration), 890 (pyridine ring C–H out-of-plane bending vibration)
4) were shown to have a coefficient offriction smaller than the TABLE 2 coefficient of friction of the lubricating base oil of Compara tive Example 1 to which the additive was not added. Thus, the Phase transition temperature' lubricant additive of the present invention was proven to Example 1 -9° C. 30° C. exhibit an effect of reducing the coefficient of friction. In Cry s —- Sma -— ISO addition, it was shown that the longer the alkyl chain length of Example 2 -24°C. 152 C. R", the better the effect of reducing the coefficient of friction Cry s —- Sma -— ISO (Comparison of Example 3 and Example 4). 'Cry: Crystal, SmA: Smectic A liquid crystal phase, Iso: isotropic liquid INDUSTRIAL APPLICABILITY Examples 3 and 4, Comparative Example 1 0098. According to the present invention, a lubricant addi tive which can exhibit an effect of reducing the coefficient of 0095) Lubricant compositions were obtained by adding friction in a small amount, and a lubricant composition and a the lubricant additive, N-alkyl-4-(5-alkyl-1,3-diox-2-yl)pyri grease composition containing the lubricant additive can be dinium bromide (6a) obtained in Example 1 or Example 2, to obtained. Therefore, high performance lubricant composition 2-ethylhexyl sebacate in amounts shown in Table 3. Com and grease composition can be produced at a low cost accord parative Example 1 shows an example of only 2-ethylhexyl ing to the present invention. sebacate without the addition of N-alkyl-4-(5-alkyl-1,3-diox 2-yl)pyridinium bromide (6a). 1. A lubricant additive comprising a rod-like liquid crystal compound possessing a cation group and an anion. TABLE 3 2. The lubricant additive according to claim 1, wherein the cation group is a pyridinium group or an ammonium group. Amount added 3. The lubricant additive according to claim 1, wherein the Additive (mass %) rod-like liquid crystal compound is 4-(1,3-diox-2-yl)pyri Example 3 Example 1 O.O1 Example 4 Example 2 O.O1 dinium salt-type rod-like liquid crystal compound shown by Comparative Example 1 None O the following formula (6):
(6)
, —CO-O-(CH2). O—, —CH, CH2—O—, or 7. The lubricant composition according to claim 6, wherein —CO—, wherein m is an integer of 1 to 30. the content of the lubricant additive is 0.0001 to 0.1 mass %. 8. A grease composition comprising the lubricant additive 4. The lubricant additive according to claim3, wherein R7 according to claim 1. and R in the formula (6) are alkyl groups. 9. The grease composition according to claim 8, wherein 5. The lubricant additive according to claim 4, wherein R' the content of the lubricant additive is 0.0001 to 0.1 mass %. in the formula (6) is an alkyl group having 8 to 22 carbon 10. The grease composition comprising the lubricant com atoms and R is an alkyl group having 1 to 4 carbon atoms. position according to claim 6 and a thickener. 6. A lubricant composition comprising the lubricant addi tive according to claim 1. c c c c c