GB813567A - Lubricating oil compositions - Google Patents

Abstract

A lubricating composition comprises a major proportion of a lubricating oil and minor proportions of (a) an oil-soluble polymeric compound having a main hydrocarbon chain to which are attached, indirectly through oxygen-containing groups, a plurality of alkyl radicals containing at least eight carbon atoms and, to different carbon atoms of the chain, a plurality of radicals containing organic nitrogen; (b) an oil-soluble polyvalent metal salt; and (c) oil-soluble saturated, non-aromatic amine having 6-36 carbon atoms. The lubricating oil may be a mineral oil of viscosity 100 s.u.s. at 100 DEG F. to 150 s.u.s. at 210 DEG F. and may be blended with a fatty oil such as castor or lard oil or synthetic lubricants such as polymerized olefines, copolymers of alkylene glycols and oxides, esters, polymeric tetrahydrofuran or polyalkyl silicone polymers. Synthetic lubricants alone or blended with fatty oils can also be used. The polymeric detergent (a) comprises a copolymer of (1) a compound having an unsaturated portion and attached thereto through an oxygen-containing group an alkyl radical of at least 8 carbons; and (2) an unsaturated nitrogen-containing compound preferably containing basic nitrogen in the form of a primary, secondary or tertiary amine, amide or amino-amide. The monomer (1) may be an ester of acrylic or alkacrylic acid with a long chain aliphatic alcohol, a vinyl ester of a long chain carboxylic acid, an ester of a vinylene dicarboxylic acid with at least one long chain alcohol or an amide of an unsaturated acid substituted at the nitrogen atom by a long chain alkyl group. The monomer (2) may be an amino substituted olefine, an ester of an aminoalcohol with an unsaturated carboxylic acid, an unsaturated ether of an aminoalcohol, an unsaturated amine, an amide of an unsaturated carboxylic acid having a nitrogen-containing substituent on the amide nitrogen, a heterocyclic nitrogen compound containing an unsaturated substituent or an N-vinyl or C-vinyl lactam. Numerous examples are given and examples are given of other monomers which may be copolymerized therewith. The molecular ratio of monomers (1) and (2) may be between 1:10 and 10:1. The wear-inhibiting additive (b) may be a basic or neutral Group II metal (preferably alkaline-earth) salt of a sulphonate, phenate or carboxylate. The sulphonates are preferably salts of petroleum sulphonic acids of molecular weight 350 to 550 of metals of Group II having an atomic number of 12 to 56, particularly alkaline earth metals. Phenates are preferably salts of polyphenols, e.g. such as are obtained by the condensation of an alkylphenol with an aldehyde, having molecular weights of 500-1100 with alkaline-earth metals. Aromatic or cycloaliphatic carboxylic acids are preferred, such as alkylated benzoic, salicyclic, resorcylic, anthranilic, naphthoic and naphthenic acids and the metals preferred in this case are the highly basic alkaline earths. The basicity of the salts used can be 2 to 1000 per cent. The sludge inhibiting additive (c) may be a primary, secondary or tertiary saturated aliphatic or cycloaliphatic mono- or polyamine such as mono-, di- and tri-hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, or octadecyl monoamines, tetraethylene pentamine, N-C12-18 alkyl propylene diamine, N-lauryl propylene diamine and the amines known commercially as "Armeen 18" (predominantly octadecylamine), "Armeen DM18" (dimethyloctadecylamine) and "Duomeen" (Registered Trade Mark) (C12H25-NH-C3H6-NH2). Optional additives include phosphosulphurized olefines and terpenes and their salts with alkali, mono-or poly-valent metals; sodium, calcium, barium, zinc and aluminium salts of alkyl, alkaryl, aralkyl, cycloalkyl and aryl phosphates and thiophosphates; metal dithiophosphates and carbamates; viscosity index improvers and pour point depressants such as the "Acryloids" (polymethacrylates), the condensation products of chlorinated wax and naphthalene; extreme pressure agents such as oil-soluble polyhaloalkanephosphones, e.g. trichloromethane-phosphonic acid, its esters, amides and amine salts; and organic sulphides. The composition may contain by weight 0.5 to 10 per cent of (a), 0.1 to 10 per cent of (b), 0.01-1 per cent of (c) and 0.1-2 per cent of optional additives, the balance being the oil. Specifications 799,036 and 810,685 are referred to.