Improved lubricating oil compositions

摘要

A succinimide of the formula: where R is a polyisobutenyl radical and X is a radical derived from tetraethylene pentamine is prepared as follows:- Polyisobutylene having a molecular weight of 615 and a bromine number of 21 is heated with maleic anhydride to form polyisobutenyl succinic anhydride which is then reacted with tetraethylene pentamine. The product is used as an additive for lubricating oils (see Division C5).ALSO:A lubricating oil composition comprises a lubricating oil and minor proportions of (A) a succinimide having the formula where R is a polycycloalkyl, polyalkyl or polyalkenyl radical having 30-200 carbon atoms and X represents one of the groups wherein R1 is an alkylene radical, R2 and R3 are alkyl radicals and n is an integer of from 1 to 6; and (B) an alkylated bis-phenol, which preferably has the formula where X represents a bridge selected from -S-, -S-S-, -Se-, -S-CH2-, -CH2-S-CH2-, -CHR-, -CR2-, -(CH2)m-, -NH- and -O- groups, R is a methyl or ethyl radical, and m is an integer of 1-3. Additives (A) and (B) are extensively exemplified. A small proportion of di-imides of succinic acid, formed during the preparation of the mono-imides (A), may be present. The lubricating oil may be mineral or synthetic, e.g. naphthenic base, paraffinic base and mixed base hydrocarbon oils, oils derived from coal products, alkylene polymers, alkylene oxide polymers and esters thereof, dicarboxylic acid esters, liquid ester or phosphorus, alkyl benzenes, polyphenyls, alkyl biphenyl ethers, or organic esters of silicic acid and silicon-containing polymers. These oils are exemplified. Optional additives referred to are esters of phosphoric and phosphorous acid (e.g. trichloroethyl phosphite, tricresyl phosphate, &c.), silicone polymers, polymeric acrylic esters (e.g. lauryl methacrylate/N-vinyl pyrrolidone copolymer), dibenzyl disulphide, the condensation product of maleic anhydride and long-chain alkenes, acidless tallow, and peroxidized aromatic extracts, all of which perform their customary functions.