Patented Aug. 7, 1951 2,563,609
UNITED STATES‘ PATENT OFFICE 2,563,609 LUBRICATIN G OIL ADDITIVES Alfred H. Matusxak, Westlield, N. 1., assignor to Standard Oil Development Company, a corpo ration of Delaware No Drawing. Application January 28, 1949, Serial No. 73,445 3 Claims. (Cl. 252—56) 1 2 This invention relates to rust preventing oil acid chloride or ester of the desired carboxylic compositions and more particularly to mineral acid may be employed instead of the carboxylic lubricating oil compositions which tend to in acid in well-known esteri?cation processes to hibit rusting and corrosion of metal parts which produce the mixed carbonate esters of this in are exposed to moisture. vention. A primary object of the present invention is Where the polyhydroxy alcohol is a diol, the the preparation of compositions which may be resulting mixed carbonate ester is formed by employed as internal combustion engine lubri esteri?cation of the diol either partially or com cants and which will also serve for the protection pletely with a carbonic acid derivative of a mono of exposed surfaces of such engines when the 10 hydroxy alcohol, employing well-known esteri same are not in use. When operating engines in ?cation methods. Where the hydroxyl groups of climates having a high humidity, rusting begins the diol are only partially esteri?ed in preparing within a vary short period of time alter the the mixed carbonate ester, the residual or free engine is shut down. The compositions of the hydroxyl group may be converted to an ester present invention are particularly valuable in 15 linkage by esteri?cation with a desired car preventing such rusting, and they are valuable boxylic acid or a derivative thereof. not only in the lubrication of internal combustion Where the polyhydroxy alcohol contains more engines but with oil bases of suitable viscosity than two hydroxyl groups, the polyhydroxy alco they may be employed as turbine oils or as hol may be partially or completely esteri?ed with lubricants for ?re arms, ordnance equipment, 20 a carbonic acid derivative of a monohydroxy industrial machinery, etc., and with more vola alcohol. The resulting mixed carbonate ester tile oil bases and in combination with fatty sub must contain at least one carbonic acid radical stances they may be applied to form protective and may contain one or more carboxylic acid coatings for metal surfaces which are exposed radicals. Where an ester-carbonate is desired, it to humid air. 25 is generally preferable to ?rst partially esteriiy The corrosion-preventing compositions of the the polyhydroxy alcohol with the desired car present invention are formed by adding to a boxylic acid, as this will generally produce a suitable oil base a mixed carbonate ester of a liquid product which can be conveniently handled monohydroxy alcohol and a polyhydric alcohol in the subsequent esteri?cation with the carbonic wherein the monohydroxy alcohol portion of the 30 acid derivative of a monohydroxy alcohol. It mixed carbonate ester consists of a saturated will be understood that in the preparation of the or unsaturated alkyl or cycloalkyl radical and mixed carbonate esters of this invention the car the polyhydroxy alcohol portion of the carbonate bonic acid derivative employed may consist 01' a consists of a radical selected from the class of mixture such as that which may be obtained alcohols containing at least two hydroxyl groups 35 by physically combining several pure carbonic and where the functional groups in the poly- ’ acid derivatives or that which may be obtained hydrlc alcohol portion may be partially or com by employing a mixture of monohydroxy alco pletely converted to other polar linkages such hols in the preparation of the carbonic acid as ester, ether, or amide linkages when the pres derivative reactant. It will be further under ence of such linkages might impart certain de 40 stood that where an ester-carbonate is desired, sired properties to the mixed carbonate ester. one or more than one carboxylic acids or deriva Where the mixed carbonate ester of this inven~ tives thereof- may be employed. In the prepara tion contains one or more free hydroxyl groups tion of these esters it is preferred to employ in the polyhydroxy alcohol portion of the car monocarboxylic acids. However, dicarboxylic bonate, it is preferred in this invention to have 45 acids may be ‘employed instead of, or along with, at least one of these free hydroxyl groups esteri the monocarboxylic acids. In the latter case, ?ed with a carboxylic acid. Such a mixed car dicarboxylic acids containing 0 to 8 carbon atoms bonate ester wherein at least one free hydroxyl in the chain between the two carboxyl groups are group has been converted to an ester group may preferred. Where dicarboxylic acids are em be called an ester-carbonate and such an ester 60 ployed, normal esteri?cation, linear esteri?ca carbonate may be formed by esterifying at least tion or cross linkage esteri?cation may occur. one hydroxyl group of the polyhydroxy alcohol In the preparation of the mixed carbonate with a carbonic acid derivative of a monohy esters of the present invention any carbonic acid droxy alcohol and esteriiying at least one hy derivative of a monohydroxy alcohol or mixture droxyl group of the polyhydroxy alcohol with a 55 of monohydroxy alcohols and any polyhydroxy carboxylic acid. In many cases, the anhydride, alcohol may be employed. The carbonic acid 2,563,009‘ 3 a 4 derivatives of monohydroxy alcohols which are stearic, oleic, linoleic, ricinoleic, eleomargic, to be employed in the preparation of the mixed eruclc, behenic, arachidic, lignoceric and similar carbonate esters of this invention include any‘ fatty acids, also the naphthenic acids, as well as carbonic acid derivative of a monohydroxy alco carboxylic acids derived by the oxidation of hol containing a saturated or'unsaturated ali petroleum products or by the oxidation of alde phatic or cycloaliphatic hydrocarbon chain of. 1 hydes such as those produced in the 0x0 process. to 30 carbon atoms per molecule. The preferred Naturally occurring products containing any of number of carbon atoms in the monohydroxy the above or similar acids, such as talloil, castor ' alcohol portion of the carbonic acid derivative oil, soybean oil, linseed oil, olive oil, tung oil, generally will be 8 to 20 carbon atoms; however, 10 rapeseed oil, menhaden oil and the like, or acids where the mixed carbonate ester contains other derived therefrom may be conveniently employed. long hydrocarbon chains such as may be ob Dicarboxylic acids such as succinic acid, maleic tained when a long chain fatty acid is employed acid, fumeric acid, azelaic acid, andsebacic‘acid to produce an ester-carbonate, the number of car may likewise be employed. bon atoms in the monohydroxy alcohol portion of 15 Some speci?c examples of ester-carbonates the carbonic acid derivative generally will be less wherein a mixed carbonate ester is further esteri than 8 carbon atoms. The carbonic acid deriva ?ed with a carboxylic acid as described above tives of monohydroxy alcohols may be conven are: pentaerythritol mono-oleate mono-allyl iently prepared by the reaction of phosgene in carbonate, pentaerythritol di-oleate mono-petro the presence of pyridine with monohydroxy alco leumcarbonate mono-ethylcarbonate, pentaery hols to give alkylchlorocarbonates or dialkyl thritol mono - laurate mono - hexyl - carbonate, carbonates. The monohydroxy alcohols which tetramethylolcyclohexanol mono-oleate mono may be utilized in the preparation of these car allylcarbonate, sorbitan mono-oleate mono-allyl bonic acid derivativas-may be saturated or un carbonate, glycerol mono-stearate mono-allyl saturated and may be individual alcohols or mix carbonate, and dipentaerythritol mono-oleate tures of alcohols such as may be obtained by dl-Co “Oxo" carbonate, pentaglycerol mono-tall physicallymixing several alcohols or by the‘ re oil ester mono-allylcarbonate, triethanol amine duction of naturally occurring fatty esters, or by mono-stearate mono-allylcarbonate and tris(hy the fermentation process, or by the reduction of droxy methyl) ‘amino methane mono-stearate an ole?n with carbon monoxide and hydrogen as 80 mono-allylcarbonate. . .I in the "Oxo” process. Among the more preferred The additives of the present invention may be ‘examples of monohydroxy alcohols may be men advantageously employed with petroleum frac tioned ethyl, propyl, allyl. amyl, 2-ethylhexyl, tions of .a wide variety, although their preferred 2-ethylbutyl “Cellosolve',” Ca Oxo, C9 Oxo, Ci: use is in lubricating oil bases to form lubricant 0x0, cetyl, oleyl, octadecyl, myristyl, linoleyl, compositions which also act as corrosion pre erucyl and lauryl alcohols, also furfuryl, tetra ventives. The base stocks may be derived from hydrofurfuryl, and cyclohexanol alcohols- The . various types of crude petroleum and may consist polyhydroxy alcohols which are to be used in the of distillates or blends of various kinds which preparation of the mixed carbonate esters of this have been refined by any of the conventional invention are selected from the. class of poly methods. Synthetic oils may also be used such hydroxy alcohols containing at least two hydroxyl as those obtained by the polymerization of ole?ns groups. Such polyhydroxy alcohols may contain or by the hydrogenation of coal or its products. ‘besides the hydroxyl groups additional groups In the case of lubricants, the base stock chosen such as nitro, carboxylic, ‘ester, amide, ether, will normally be that oil which without the new pyridyl, quinolyl, phenyl, sulfonate and primary, 45 additives gives the optimum performance in the _ secondary, and tertiary amino groups in the service contemplated. These base oils may vary molecule. A preferred group of polyhydroxy al considerably in viscosity and other properties de cohols comprises those alcohols containing four pending upon the particular uses for which they and five hydroxyl groups per molecule, among are desired. For crankcase use they usually range which pentaerythritol, sorbitan and tetramethyl 60 from about 40 to 130 seconds viscosity Saybolt olcyclohexanol are especially suitable examples. at 210 F. The viscosity index may range from As further illustrations of polyhydroxy alcohols less than 0 to 130 or even higher. Turbine oils which may be conveniently employed in accord usually have a viscosity of 40 to 60 seconds Say ance with the present invention may be men bolt at 210° F. Use may also be found in torque tioned ethylene. glycol, propylene glycol, 1,3 55 converter ?uids having a viscosity of 35 to 45 propanediol, pentaglycerol, glycerol, diglycerol, . seconds at 210° F. and a viscosity index of 155 polyglycerol, tetramethylolcyclopentanol, anhy to 1'70. Corrosion-preventing compositions other dro-ennea-heptitol, 2-amino—2-methylol-1,3