Viscosity index improver for lubricating oil comprises a oil soluble copolymer prepared from acrylic monomers, alkyl(meth)acrylates and an unsaturated monomer having hydroxyl, amide or carboxyl groups

摘要

A viscosity index improver comprises a oil soluble copolymer having a weight average molecular weight of 3000-500000 containing 5-90 wt.% acrylic monomers, 5-90 wt.% of a monomer comprising 8-17 C alkyl(meth)acrylates or linear 18-24 C alkyl(meth)acrylates and 5-50 wt.% of an unsaturated monomer having hydroxyl, amide or carboxyl groups. A viscosity index improver (I) comprises a oil soluble copolymer having a weight average molecular weight of 3000-500000 containing: (a) 5-90 wt.% monomers of formula (1); (b) 5-90 wt.% of a monomer comprising 8-17 C alkyl(meth)acrylates or linear 18-24 C alkyl(meth)acrylates; (c) 5-50 wt.% of an unsaturated monomer having hydroxyl, amide or carboxyl groups and optionally; (d) 0-15 wt.% of other alkyl(meth)acrylates; (e) unsaturated 2-20C hydrocarbons (F) vinyl ketones; (f) unsaturated epoxy compounds; (g) halogen containing unsaturated monomers; (h) alkylalkenyl ethers; (i) alkenyl carboxylates and; (j) other nitrogen containing unsaturated monomers. CH2=C(R')-COO-(A-O)n-R (1) R' = N or CH3; A = 2-4C alkenyl; n = 0, 1-20; R = branched 18-36C alkyl that is free from polymethylene groups having more than 16C atoms Independent claims are included for: (1) a concentrate comprising 20-90 wt.% of the improver (I) and 10-80 wt.% diluent and; (2) a lubricating oil composition comprising a base oil and 0.01-45 wt.% of the viscosity improver (I).