Patent GB-818254-A (GB)
Title: Lubricating oil compositions
Inventor: LORENSEN LYMAN EDWARD
IPC: C10M149/10
Filed: 1957-06-24
Abstract: Lubricating oil compositions comprise a major proportion of a mineral oil and, as a pour-point depressant, a minor proportion of an oil-soluble copolymer having a molecular weight, as determined by the light scattering method, of between 50,000 and 2,500,000, of a vinyl pyridine and at least two esters in a mol. ratio of from 1 : 10 to 10 : 1 of acrylic acid or an alphaalkyl acrylic acid in which the alkyl substituent contains up to four carbon atoms, with dissimilar aliphatic alcohols containing from 10 to 20 carbon atoms but one containing at least 4 carbon more than the other, the mol. ratio of the vinyl pyridine to the esters in the copolymer being between 1 : 2 and 1 : 10 and the average side chain length of the copolymer being from 10 to 16 carbon atoms. Vinyl pyridines specified are the 2-, 3- and 4-isomers, 2-methyl-5-vinyl pyridine, 4-methyl-2-vinyl pyridine, 5-ethyl-2-vinyl pyridine and 2-butyl-5-vinyl pyridine.  Specified alcohols from which the unsaturated esters are derived are decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and eicosyl alcohols. The mineral oils used in the compositions may be blended with fatty oils such as castor oil and lard oil and/or with synthetic lubricants such as polymerized olefins, copolymers of alkylene oxides and glycols, 2-ethylhexyl sebacate and dimethyl silicone polymers.  Also present in the compositions may be "Acryloids," wax naphthalene condensation products, isobutylene polymers, alkylstyrene polymers, sodium nitrite, lithium nitrite, diisopropylammonium nitrite, dicyclohexylammonium nitrite, calcium or zinc dicyclohexylthiophosphate or methylcyclohexylthiophosphate, trichloroethyl phosphite, tricresyl phosphate, di-"Lorol" (Registered Trade Mark) phosphate, phosphorus pentasulphide-terpene reaction products, wax disulphide, ethylene bistolyl sulphide, calcium petroleum sulphonate, a calcium salt of an octyl phenol-formaldehyde condensation product, octadecylamine and 2,6-di-tert.-butyl-4-methylphenol.ALSO:Copolymers having a molecular weight, as determined by the light scattering method, of between 50,000 and 2,500,000, are made by the copolymerization of a vinyl pyridine and at least two esters in a mol. ratio of from 1:10 to 10:1 of acrylic acid or an alpha-alkyl acrylic acid in which the alkyl substituent contains up to four carbon atoms, with dissimilar aliphatic alcohols containing from 10 to 20 carbon atoms but one containing at least 4 carbon atoms more than the other, the mol. ratio of the vinyl pyridine to the esters in the copolymer being between 1:2 and 1:10 and the average sidechain length of the copolymer being from 10 to 16 carbon atoms.  Vinyl pyridines specified are the 2-, 3-, and 4-isomers, 2-methyl-5-vinyl pyridine, 4-methyl-2-vinyl pyridine, 5-ethyl-2-vinyl pyridine and 2-butyl-5-vinyl pyridine.  Specified alcohols from which the unsaturated esters are derived are decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and eicosyl alcohols. The copolymerization of the monomers may be carried out in bulk, emulsion, suspension or solution with the aid of catalysts such as benzoyl, lauroyl, di-tert.-butyl peroxides, 2,2-bis-(tert.-butylperoxy)butane, tert.-butyl pelargonate, peracetic acid, hydrogen peroxide, sodium or potassium persulphate or percarbonate, azodiisobutyronitrile, sodium bisulphite and dimethyl sulphoxide.  The copolymers are used as additives to mineral lubricating oils.