Patent GB-662650-A (GB)
Title: Synthetic lubricants
IPC: C07C69/34
Filed: 1948-11-30
Abstract: A complex ester is prepared by esterifying an aliphatic dicarboxylic acid with an equimolar proportion of a glycol until half the theoretical water of esterification has been evolved, and then esterifying the unreacted carboxyl and hydroxyl groups of the half ester with a monohydric aliphatic alcohol and a monocarboxylic aliphatic acid respectively.  Esters may have the formul R11OOC-R-COO-R1-OOC-R111 or R11OOC-COO-R1-OOC-R111, where R may be a series of saturated C2 or higher aliphatic hydrocarbon radicals linked by one or more ether-oxygen and/or thio-ester sulphur atoms, the total number of C, O, and S atoms being 3-80, and the number of S atoms not more than 2; R1 may be a series of saturated C2 or higher aliphatic hydrocarbon radicals linked by one or more ether-oxygen and/or thio-ether sulphur atoms, the total number of C, O, and S atoms being 5-80, and the number of S atoms not more than 2; R11 may be a series of saturated C2 or higher aliphatic hydrocarbon radicals linked by 1-5 ether-oxygen and/or thio-ether sulphur atoms, the total number of C, O and S atoms being 4-20, and the number of S atoms no more than 2; and R111 may be a series of C2 or higher aliphatic hydrocarbon radicals linked by 1-5 ether-oxygen atoms, there being at least one carbon atom between the carboxyl group and the nearest ether-oxygen atom, and the total number of C and O atoms is 3-22. The molecular weight should be at least 300.  Preferred dicarboxylic acids are straight-chain acids of the paraffinic group having 6-10 carbon atoms.  Preferred monohydric alcohols are aliphatic primary alcohols of 6-10 carbon atoms, and preferred monocarboxylic acids are C2-C10 fatty acids.  The glycols include polyethylene or propylene glycols, and glycols containing thio or ether linkages.  Monohydric alcohols include ether alcohols and "oxo" alcohols.ALSO:A complex ester is prepared by esterifying an aliphatic dicarboxylic acid with an equimolar proportion of a glycol until half the theoretical water of esterification has been evolved, and then esterifying the unreacted carboxyl and hydroxyl groups of the half ester with a monohydric aliphatic alcohol and a monocarboxylic aliphatic acid respectively.  Esters for use as lubricants may have the formul R11OOC-R-COO-R1-OOCR111 or R11OOC-COO-R1-OOCR111, where R is an aliphatic hydrocarbon radical of 1-26 carbon atoms or a series of saturated C2 or higher aliphatic hydrocarbon radicals linked by one or more ether-oxygen and/or thio-ether sulphur atoms, the total number of C, O and S atoms being 3-80, and the number of S atoms not more than 2; R1 is a saturated C2 to C18 aliphatic hydrocarbon radical or a series of saturated C2 or higher aliphatic hydrocarbon radicals linked by one or more ether-oxygen and/or thio-ether sulphur atoms, the total number of C, O and S atoms being 5-80, and the number of S atoms not more than 2; R11 is a C1 to C20 aliphatic hydrocarbon radical or a series of saturated C2 or higher aliphatic hydrocarbon radicals linked by 1-5 ether-oxygen and/or thio-ether sulphur atoms, the total number of C, O and S atoms being 4-20, and the number of S atoms not more than 2; and R111 is a C1 to C22 aliphatic hydrocarbon radical or a series of C2 or higher aliphatic hydrocarbon radicals linked by 1-5 ether-oxygen atoms, there being at least one carbon atom between the carboxyl group and the nearest ether-oxygen atom, and the total number of C and O atoms is 3-22 or R111 is two aliphatic hydrocarbon groups linked by one thio-ether sulphur atom separated from the carboxyl group by at least one carbon atom, and the total number of carbon atoms is 2-21.  The molecular weight should be at least 300.  Preferred dicarboxylic acids are straight chain acids of the paraffinic group having 6-10 carbon atoms.  Preferred monohydric alcohols are aliphatic primary alcohols of 6-10 carbon atoms, and preferred monocarboxylic acids are C2-C10 fatty acids.  The glycols include ethylene glycol and its homologues containing up to 18 carbon atoms, polyethylene or propylene glycols, and glycols containing thio or ether linkages, e.g. thiodiglycol, 1,2-bis-(2-hydroxyethylmercapto) - ethane, and bis-[2-(2-hydroxyethoxy)-ethyl]-sulphide.  Monohydric alcohols include ether alcohols and " oxo " alcohols.  Esterification may be effected in toluene with p-toluene sulphonic acid monohydrate as catalyst.  Properties are given of esters prepared from adipic, sebacic, C14-C18 or C10 to C12 alkenylsuccinic acids; thiodiglycol, tri-, tetra- or higher poly-ethylene glycol, tri- or penta-methylene glycol; n-caproic, n-caprylic, n-butyric or 2-ethylcaproic acid; and 2-ethylhexanol, C10 or C15-C19 " oxo " alcohol or methyl alcohol.ALSO:A complex ester is prepared by esterifying an aliphatic dicarboxylic acid with an equimolar proportion of a glycol until half the theoretical water of esterification has been evolved, and then esterifying the unreacted carboxyl and hydroxyl groups of the half ester with a monohydric aliphatic alcohol and a monocarboxylic aliphatic acid respectively.  Esters for use as lubricants which may be blended with mineral lubricating oils, antioxidants, viscosity index improvers, thickeners, pour depressants, dyes, &c. may have the formul  R"OOC-R-COO-R\sv-OOC R"\sv or R"OOC-COO-R\sv-OOC R"\sv, where R is an aliphatic hydrocarbon radical of 1-26 carbon atoms or a series of saturated C2 or higher aliphatic hydrocarbon radicals linked by one or more ether-oxygen and/or thio-ether sulphur atoms, the total number of C, O, and S atoms being 3-80, and the number of S atoms not more than 2; R\sv is a saturated C2 to C18 aliphatic hydrocarbon radical or a series of saturated C2 or higher aliphatic hydrocarbon radicals linked by one or more ether-oxygen and/or thio-ether sulphur atoms, the total number of C, O, and S atoms being 5-80, and the number of S atoms not more than 2; R" is a C1 to C20 aliphatic hydrocarbon radical or a series of saturated C2 or higher aliphatic hydrocarbon radicals linked with 1-5 ether-oxygen and/or thio-ether sulphur atoms, the total number of C, O, and S atoms being 4-20, and the number of S atoms no more than 2; and R"\sv is a C1 to C22 aliphatic hydrocarbon radical or a series of C2 or higher aliphatic hydrocarbon radicals linked by 1-5 ether-oxygen atoms, there being at least one carbon atom between the carboxyl group and the nearest ether-oxygen atom, and the total number of C and O atoms is 3-22 or R"\sv is two aliphatic hydrocarbon groups linked by one thio-ether sulphur atom separated from the carboxyl group by at least one carbon atom, and the total number of carbon atoms is 2-21.  The molecular weight should be at least 300.  Preferred dicarboxylic acids are straight chain acids of the paraffinic group having 6-10 carbon atoms.  Preferred monohydric alcohols are aliphatic primary alcohols of 6-10 carbon atoms, and prefered monocarboxylic acids are C2-C10 fatty acids.  The glycols include ethylene glycol and its homologues containing up to 18 carbon atoms, polyethylene or propylene glycols, and glycols containing thio or ether linkages, e.g., thiodiglycol, 1, 2-bis-(2-hydroxyethylmercapto)ethane, and bis - [2 - (2-hydroxyethoxy)ethyl] sulphide.  Monohydric alcohols include ether alcohols and "oxo" alcohols.  Properties are given of esters prepared from adipic, sebacic, C14-C18 or C10 to C12 alkenylsuccinic acids; thiodiglycol, tri-, tetra- or higher poly-ethylene glycol, tri- or penta-methylene glycol; n-caproic, n-caprylic, n-butyric or 2-ethyl-caproic acid; and 2-ethylhexanol, C10 or C15-C19 "oxo" alcohol or methyl alcohol.