| abstract |
Provided is a lubricating oil composition having excellent sludge dispersibility, friction characteristics, viscosity index and low temperature viscosity. The main component of the mineral oil base oil is 0.1 to 30% by weight of the following copolymer (A) based on the weight of the composition, and 0.01 to 30% of the specific organic phosphorus compound (P). A lubricating oil composition comprising 5% by weight. Copolymer (A): A copolymer having the monomer (a) represented by the following general formula as an essential constituent monomer. Formula CH 2 = C (R 1) -COO (A-O) n- (CH 2) p-CH (R 2) -R 3 [Wherein, R 1 is a hydrogen atom or a methyl group, R 2 and R 3 are groups independently selected from a linear alkyl group having 1 to 16 carbon atoms and a branched alkyl group having 3 to 34 carbon atoms, The number of consecutive methylene groups in the branched alkyl group is 16 or less, the total carbon number of R 2 , R 3 and p CH 2 groups is 18 to 36, and A is 2 to 4 carbon atoms. An alkylene group, n is 0 or an integer of 1 to 20, and p is 0 or an integer of 1 to 15. ] [Selection figure] None |