SMOEREMIDDEL

1356405 Synthetic ester oils INVENTA AG 5 Aug 1971 [7 Sept 1970] 36859/71 Heading C2C [Also in Division C5] Novel ester oils in which the alcohol moieties comprise moieties of a C 2 -C 20 polyol containing primary hydroxy groups and/or of a branched chain C 3 -C 18 monoalcohol and the acid moieties comprise moieties of acids obtained in admixture as by-products in the oxidation of a C 6 - C 12 cycloalkane by means of a gas comprising molecular oxygen to give a cycloalkanol/cycloalkanone mixture as predominant reaction product, are synthesized by an esterification process wherein the alcoholic starting material comprises an aforesaid polyol and/or branched monoalcohol and the acidic starting material comprises the aforesaid mixture of acids or by an appropriate transesterification. A typical mixture of acids obtained by oxidation of cyclohexane using air and, for example, cobalt naphthenate as catalyst, followed by extraction with aqueous alkali, acidification and extraction of the liberated acids with cyclohexane, comprises 5-45% by weight of butyric acid, 40-80% by weight of valeric acid and 15- 55% by weight of caproic acid. If, however, the final extraction is carried out with methyl ethyl ketone, then the mixture of acids obtained comprises 40-60% by weight of the above mixture together with 20-40% by weight of hydroxycaproic acid and 20-40% by weight of a mixture of dicarboxylic acids comprising 65-85% by weight of adipic acid and lesser amounts of succinic and glutaric acids. Preferred polyols are polyethylene glycol, dimethylpropanediol, the polyethylene glycol 200 di-ester of decanedicarboxylic acid, trimethylol propane and pentaerythritol and the preferred branched chain C 3 -C 18 monohydric alcohol is 2-ethylhexanol. The acid starting material may also comprise additional monocarboxylic acids and/ or C 6 -C 12 dicarboxylic acids, e.g. decanedicarboxylic acid. The synthetic ester oils may be used as lubricating oils, e.g. mixed with either an antioxidant or a mineral oil.