Patent GB-696064-A (GB)
Title: Lubricating compositions
Inventor: EVANS ELLIOTT ALFRED
IPC: C10M131/12
Filed: 1950-02-27
Abstract: A lubricating composition comprises (1) an ester or mixture of esters of general formula <FORM:0696064/III/1> wherein R is the radical CH=CH or (CH2)n, where n is an integer from 2 to 8, which radical may be substituted by alkyl or hydroxy groups, and R1 and R2 are the same or different branched chain alkyl or alkyl-substituted cycloalkyl radicals having at least 4 carbon atoms, and (2) from 0.05 to 2.0 per cent by weight (on the weight of the final composition) of a metal salt of an organic dithiophosphoric acid of general formula <FORM:0696064/III/2> where R3 and R4 are the same or different and are alkyl, aryl, aralkyl, cycloalkyl or alkoxyalkyl radicals and M is a polyvalent metal of valency x.  Esters which may be employed are the branched chain di-alkyl and di-(alkylcycloalkyl) esters of maleic, succinic, pyrotartaric, glutaric, adipic, pimelic, suberic, azelaic and preferably sebacic acids.  Specified esters are di (1-methyl-4-ethyl-octyl) glutarate, di (2-ethylhexyl) sebacate, di (2-ethylhexyl) adipate, di (3-methylbutyl) azelate, di (2-ethylhexyl) azelate, di (3:3:5-trimethylhexyl) sebacate, di (2-ethylhexyl) maleate, di (methylcyclohexyl) adipate, 2-ethylhexyl 1-methylheptyl sebacate and di-isoamyl succinate. The acidity of the esters should be kept as low as possible. Metal organic dithiophosphates include the calcium, barium, zinc, aluminium, chromium, nickel, cobalt, manganese and magnesium salts of acids such as di (a-methylisoamyl) dithiophosphoric acid, di (2-ethylhexyl) dithiophosphoric acid, di (n-amyl) dithiophosphoric acid, di-lauryl dithiophosphoric acid, di (p-octylphenyl) dithiophosphoric acid, di (octylcresyl) dithio-phosphoric acid, di (b -butoxyethyl) dithiophosphoric acid, 3-methyoxybutyl 2-ethylhexyl dithiophosphoric acid, tetrahydrofurfuryl octylcresyl dithiophosphoric acid, di (methylcyclohexyl) dithiophosphoric acid.  Salts specified include zinc di (2-ethylhexyl) dithiophosphate, magnesium di (2-ethylhexyl) dithiophosphate, zinc di (a-methylisoamyl dithiophosphate, nickel di (methylcyclohexyl) dithiophosphate, barium b -butoxyethyl 3:3:5-trimethylhexyl dithiophosphate, cobalt 3-methoxybutyl 2-ethylhexyl dithiophosphate, chromium di (p-octylphenyl) dithiophosphate, zinc di (b -butoxyethyl) dithiophosphate, and barium didecyl/dilauryl dithiophosphate.  Preferably the composition also contains about 0.01-5 per cent by weight (on the weight of the final composition) of a metal salt of an oil-soluble petroleum sulphonic acid, such as the mahogany acids: polyvalent metal salts such as those of calcium, barium, strontium, magnesium, zinc, aluminium, nickel, cobalt, manganese, cadmium, chromium and tin are preferred. Additives with anti-corrosive properties may also be added to the composition: these include the reaction products of aldehydes and ketones with basic water-soluble non-aromatic primary and secondary amines, such as dimorpholinyl phenyl methane, benzal cyclohexylamine, and spiro-cyclohexane 1-21(31-b -hydroxyethyl) oxazolidine. Thickeners such as polymethyl methacrylate and anti-wear agents such as organic phosphates and phosphites (tricresyl phosphate is specified) may also be added.  Mineral oil in amount not exceeding 50 per cent by weight of the weight of the composition may also be added.  Specific examples are (1) 99 per cent di(2-ethylhexyl) sebacate and 1 per cent chromium di (octylcresyl) dithiophosphate, (2) 50 per cent di (2-ethylhexyl) sebacate, 49.65 per cent di (3:3:5-trimethylhexyl) sebacate, 0.25 per cent zinc di (a-methylisoamyl) dithiophosphate and 0.1 per cent tin petroleum sulphonate, and (3) 50 per cent di (2-ethylhexyl) sebacate, 49.55 per cent di (3:3:5-trimethylhexyl) sebacate, 0.25 per cent zinc di (a-methylisoamyl) dithiophosphate, 0.1 per cent calcium petroleum sulphonate and 0.1 per cent dimorpholinyl phenyl methane. Specification 588,864 is referred to.