Patent GB-828956-A (GB)
Title: Lubrication composition
Filed: 1957-06-25
Abstract: An extreme pressure additive to synthetic lubricants of the polyester type comprises a dimer of an ethylenic fatty acid having 12 to 22 carbon atoms and is added to the oil in minor proportion. The polyester may be a diester of a dicarboxylic acid, preferably of 6 to 12 carbon atoms with aliphatic alcohols preferably of 4 to 20 carbon atoms or ether alcohols such as "Cellosolve" (Registered Trade Mark) or Carbitol, e.g. di-iso-octyl, di-2-ethylhexyl, dilauryl, and di-2-butoxyethyl azelates; di-2-ethyl-hexyl, di-sec.-amyl, di-2-ethoxyethyl, di-2 - (21 - methoxyethoxy) - ethyl and di - 2 - (21-ethyl-butoxy)-ethyl sebacates; di-2-ethylhexyladipate; the di-2-ethylhexyl alkenylsuccinates and the di-2-(21-butoxyethoxy)-ethyl alkenylsuccinates. Polyester lubricants formed by reaction of a dicarboxylic acid, a glycol and a monohydric alcohol or a monocarboxylic acid, as described in U.S.A. Specification 2,628,974, can be used, e.g. polyesters formed from 2-ethyl-1,3-hexanediol, sebacic acid and 2-ethylhexanol, or diethyleneglycol, adipic acid and 2-ethyl-hexanoic acid.  Polyesters formed from monocarboxylic acids and glycols can also be used, the acid preferably containing at least 6 carbon atoms and the glycol being either a straight glycol or an ether glycol, e.g. the di-n-decanoate of 1,4-butenediol, the di-2-ethyl-hexanoate of 1,6-hexanediol, the di-laurate of 1,4-hexanediol, the di-octanoate of 1,5-pentanediol, the dilaurate of tetraethyleneglycol or triethylene-glycol and the dioctoate of pentaethyleneglycol. Sulphur analogues of the abovedescribed esters can be employed, e.g. di-2-ethylhexyl thiosebacate, di-n-octyl thioadipate, the dilaurate of 1,5-pentanedithiol and the reaction product of adipic acid, thioglycol and 2-ethylhexyl mercaptan.  The extreme pressure additive should contain at least 70% by weight of the dimer, which may be a dimer of 4-do-decenoic, 5,9-dimethyl-2,8-decadienoic, myristoleic, palmitoleic, oleic, linoleic (9,11-, 10,12-, and 11,13-octadecadienoic), linolenic, erucic and 13,15-docosadienoic acids.  A mixture of monomer, dimer, trimer and higher polymers resulting from the dimerization of the acid can be used.  Amounts of 0.01 to 1% by weight can be used.  Other additives which may be used include as antioxidant 0.1-1.5% of phenothiazine or up to 2% of naphthylamines, diphenylamines or phenylene diamines, as viscosity index improvers 1-20% of methacrylate ester copolymers of M.W. 5000-20,000, as metal deactivators 0.05-1% of a reaction product between 1 mol. of an aliphatic polyamine having two primary amino groups and two mols. of an aromatic aldehyde of which a number are specified, as anti-wear agent up to 5% of di-(o-chlorophenyl)-phenyl phosphate and detergents such as up to 20% of calcium or sodium salts of petroleum sulphonates having molecular weights of 300-500, the barium salt of wax-substituted benzene sulphonate, metal alkyl phenols such as calcium phenyl stearate or zinc alkyl salicylate or metal alkyl phenol sulphides such as the barium salt of wax-substituted phenol carboxylate sulphide.  Specification 813,484 also is referred to.