Ester lubricants

1,129,965. Lubricants. BRITISH PETROLEUM CO. Ltd. 22 Dec., 1965 [22 July, 1965], No. 31249/65. Heading C5F. A lubricant comprises a blend of two ester oils (1) an aliphatic ester consisting of one or more neutral polyesters prepared by reacting in one or more stages (a) a mono- and/or polyhydric C 5 -C 15 alcohol having no #-hydrogen atoms with respect to any OH group and (b) a mono- and/or polycarboxylic C 2 -C 14 acid and (2) a liquid aromatic ester consisting of one or more diesters of formula XOOCRCOOY where R is a saturated C 1 -C 14 hydrocarbon group, and X and Y are C 6 -C 20 hydrocarbon groups which may or may not be substituted with one or more ether oxygen atoms attached directly to benzene rings, each of which is either a benzene ring or contains a benzene ring directly attached to the -COO- group. The composition may have dissolved therein one or more organic complexes or salts of the transition metals (including copper) in an amount which gives a metal content of up to 500 p.p.m. based on the total weight of the composition. Metal compounds specified are manganous and cobaltous acetylacetonates, cupric phthalocyanine and cupric stearate. Contentional amine, phenolic and sulphur containing anti-oxidants. Copper passivates, e.g. imidazoles, pyrazoles, triazoles, phosphites, and trithiophosphites may also be added.