Patent ID: 8846589
Filing Date: 2014-09-30
Classification: C10M,C10N

Abstract:
1. A lubricating oil composition for transmissions consisting essentially of components (A), (B), (C) and (D), wherein (A) is a lubricating base oil with a kinematic viscosity at 100° C. adjusted to 1.5 to 6 mm (A2) is a lubricating base oil with a kinematic viscosity at 100° C. of 7 to 50 mm (B) is a poly(meth)acrylate-based additive containing a structural unit represented by formula (1) and having a weight-average molecular weight of 60,000 to 300,000, so that the composition has a kinematic viscosity at 100° C. of 3 to 8 mm wherein R 1 is hydrogen or methyl, R 2 is a hydrocarbon group having 5 to 20 carbon atoms or a group represented by —(R) a -E wherein R is an alkylene group having 5 to 20 carbon atoms, E is an amine residue or a heterocyclic residue, each having 1 or 2 nitrogen atoms and 0 to 2 oxygen atoms, and a is an integer of 0 or 1; (C) is an imide-based friction modifier represented by formula (3) and/or a derivative thereof in an amount of 1 to 5 percent by mas based on the total amount of the composition, wherein R 14 and R 15 are each independently a straight-chain or branched hydrocarbon group having 8 to 30 carbon atoms, R 16 and R 17 are each independently a hydrocarbon group having 1 to 4 carbon atoms, and n is an integer of 1 to 7; and (D) is a sulfur-free phosphorus-based extreme pressure additive.