Patent GB-750560-A (GB)
Title: Ester lubricants from diols
Inventor: HARTLEY JAMES
IPC: C10M169/00
Filed: 1954-05-14
Abstract: A synthetic lubricating oil comprises a mixture of liquid esters, one of which is a diester of a saturated, branched chain, diprimary diol with a straight chain fatty acid having at least 4 carbon atoms in the molecule, and the other of which is a diester of a saturated, straight chain, diprimary diol, having at least 3 carbon atoms in the molecule, with a branched chain fatty acid having at least 4 carbon atoms in the molecule, the mol ratio of the first diester to the second diester being between 65:35 and 2:98.  The mol ratio is preferably between 1:1 and 1:4.  The branched chain diol may be 2-methyl-, 2, 2-dimethyl-, 2-methyl-2-ethyl, or 2, 2-diethyl-propane-1, 3 diol, 2-ethyl-butane-1, 4-diol, 2- or 3-ethyl-pentane-1, 5-diol, 2, 3-, 2, 4-, 2, 5-2, 2- or 3, 3-dimethylhexane-1, 6-diol, 2- 2, 4- or 2, 4, 4-trimethylhexane-1, 6-diol, 2-methyl-3-ethyl and 2-ethyl-3-methyl or 3, 3-diethyl-heptane-1, 7-diol; polymers or copolymers of these diols may be used.  The straight chain fatty acid may be valeric, caproic, heptoic, caprylic, pelargonic, capric, undecylic, lauric, tridecylic, myristic, palmitic, stearic or arachidic acids.  Mixtures of acids derived from cracked paraffin wax may be used.  Examples of the first diester are 2, 4, 4-trimethylhexane-1, 6-diol dicaprate or dicaprylate, those derived from a mixture of 2, 2, 4- and 2, 4, 4-trimethylhexane-1, 6-diol and a mixture of straight chain fatty acids containing 8 to 13 or 10 to 13 carbon atoms in the molecule, 2, 5-dimethylhexane-1, 6-diol dicaproate, 3, 3-dimethylhexane-1, 6-diol diheptoate and 3, 3-diethylheptane-1, 7-diol divaleriate. The straight chain diol may be propane-1, 3-diol, butane-1, 4-diol, pentane-1, 5-diol, hexane-1, 6-diol, heptane-1, 7-diol, octane-1, 8-diol, nonane-1, 9-diol, decane-1, 10-diol, or dodecane-1, 12-diol; polymers of these diols may be used.  The branched chain fatty acid may be 2-, 3- or 4-methyl valeric acid, 2-ethyl-valeric acid, 2-, 3-, 4-, or 5-methylcaproic acid, 2-ethyl caproic acid, 4-methyl-2-ethyl caproic acid, 2-, 3-, 4-, 5- or 6-methyl caprylic acid, 2-, 3-, 4-, 5- or 8-methyl pelargonic acid, 3-, 4- or 8-methylcapric acid, 2-methyl lauric acid, isomyristic acid, 2-methyl palmitic acid, 2-methylstearic acid, 2, 2-, 2, 3- or 3, 3- dimethylbutyric acid, 2, 5-dimethyl caproic acid or 3, 5, 5-trimethyl caproic acid.  Examples of the second diester are diethylene or di-b -propylene glycol di (3, 5, 5-trimethyl hexoate), hexane-1, 6-diol di (2-ethylhexoate), hexane-1, 6- diol di (3, 5, 5-trimethylhexoate), dihexylene glycol di (2-ethylhexoate), heptane-1, 7-diol diisomyristate, pentane-1, 5-diol di (2-ethylbutyrate), di (2-methylvalerate) or di (2-ethylhexoate), and propane-1, 3-diol di (2-ethylhexoate). The lubricating oil may contains as pour point depressors and viscosity index improvers 2 to 30 per cent by weight of polymers, or copolymers of esters of acrylic acid or a 2-alkylacrylic acid, such as polymers of methyl, ethyl, n-propyl, isopropyl, isobutyl, lauryl, phenyl or benzyl esters of acrylic, methacrylic, 2-ethylacrylic and 2-propylacrylic acid.  The oil may also contain as anti-lacquering agents salts of aromatic carboxylic acids or phenols with a Group II metal, such as zinc or calcium, in an amount to give 0.01 to 1.0 per cent by weight of metal.  The aromatic acid may be benzoic, naphthoic, 4-tert.-butyl benzoic, 2, 4-ditertiary butyl benzoic, di-isopropylsalicylic, octylsalicylic, pentadecenylsalicylic, octadehylsalicylic, stearyl salicylic and octyl 4-hydroxybenzoic acids.  Suitable phenols are phenol, naphthols, cresols, amyl, octyl, nonyl, decyl, tetradecyl, pentadecenyl and octadecyl phenols, salts of phenols derived from condensation products of hydrocarbon substituted phenols with formaldehyde or acetaldehyde or polymer thereof, may be used.  The oil may contain an extreme pressure additive such as trialky, triaryl or trialkaryl or phosphate, e.g. trioctyl or tricresyl phosphate, or a haloalkylphosphonate such as monobutyl hydrogen trichloromethyl phosphonate and its amine salts. Antioxidants such as alkylated phenols and diphenols and phenothiazine and its alkyl substitution products may be added.