Patent GB-799037-A (GB)
Title: Lubricating oil compositions
IPC: C10M165/00
Filed: 1956-09-24
Abstract: A lubricating composition, suitable for use as an engine oil, comprises a major proportion of a lubricating oil and minor proportions of (1) an oil-soluble polymeric compound as defined below, and (2) an oil-soluble phosphorus compound containing at least one P-C linkage.  Ingredient (1) has a molecular weight of at least 1000 and a linear hydrocarbon chain bearing a plurality of the same or different polar and nonpolar groups.  The polar groups are groups consisting of or containing -OR, -OOCR, -OCOOR, -COOR, -SCN, -CN, -CONR, -COONR or a heterocyclic nitrogen-containing group (R being hydrogen, an alkyl group of either 4 carbon atoms or less or 8 carbon atoms or more, or an aliphatic basic nitrogen-containing group), while the non-polar groups are hydrocarbon groups containing at least 8 carbon atoms. Polymeric compounds suitable as ingredient (1) are (a) copolymers of alpha-olefins with acrylic compounds (e.g. acrylic acid, acrylamide, acrylonitrile and the corresponding methacrylic compounds); (b) copolymers of alpha-olefins with vinyl halides or esters (e.g. vinyl chloride or acetate), which copolymers have been after-treated to convert the halide or ester groups to -OH groups; (c) copolymers of polymerizable heterocyclic nitrogen-base compounds (e.g. vinyl pyridines and alkyl-substituted vinyl pyridines) with polymerizable unsaturated materials free of heterocyclic nitrogen-containing radicles (e.g. acrylic acid and alpha-substituted acrylic acids and their esters, nitriles and amides); and (d) copolymers of acrylic or alpha-alkyl-substituted acrylic esters of alkyl tertiary amino alkanols with the corresponding esters of other saturated aliphatic alcohols. Ingredient (2) may be an unsubstituted or halogen-substituted phosphinic, phosphonic or phosphonous acid, a partial or full ester thereof, or a salt thereof.  Examples are given of phosphinic, phosphonic, thiophosphinic, thiophosphonic and selenophosphonic acids wherein the hydrocarbon radicle attached to the phosphorus atom is aliphatic, cycloaliphatic or aromatic or carries halogen substituents (e.g. chlorine and/or bromine, or fluorine).  Alkyl, alkenyl, cycloalkyl and aromatic (including chlorophenyl and nitrophenyl) esters of some of these acids are also specified as well as primary, secondary and tertiary aliphatic amine, dicyclohexylamine and morpholine salts thereof. The lubricating composition may also contain foam inhibitors (e.g. silicone polymers), corrosion inhibitors (e.g. calcium or zinc salts of organic dithiophosphoric acids), detergents (e.g. neutral or basic alkaline earth petroleum sulphonates), antioxidants (e.g. amines or alkyl phenols), pour point depressants and viscosity index improvers (e.g. polymethacrylates).  The lubricating oil employed in the lubricating composition may be mineral or synthetic or a mixture of both and may be blended with fatty oils.  Synthetic lubricating oils mentioned are polymerized olefins, copolymers of alkylene glycols and oxides, esters (e.g. di-2-ethyl hexylsebacate, dioctylphthalate and trioctyl phosphate), polymeric tetrahydrofuran and polyalkyl silicone polymers.  In the examples, mineral lubricating oil compositions are described in which ingredient (1) is hydrolysed copolymer of octadecene-1/vinyl acetate, and ingredient (2) is C12-C15-tertiary alkyl primary amine salt of trichloromethanephosphonic acid, or dibutyl, diphenyl or di-p-chlorophenyl trichloromethane phosphonate. Dodecyl polymethacrylate and C14-C18 alkyl polymethacrylate are present as additional ingredients.  Specifications 777,773 and 799,036 are referred to.