Star polymer lubricating composition

摘要

The invention provides a lubricating composition containing (a) 0.1 to 15 wt % of a polymer with (i) a weight average molecular weight of 100,000 to 500,000; and (ii) a shear stability index of 10 to 60; (b) a phosphorus-containing acid, salt, or ester; (c) a dispersant; and (d) an oil of lubricating viscosity. The invention further provides a method for lubricating a mechanical device with the lubricating composition.

主权项

1. A lubricating composition comprising:
(a) about 0.1 to about 15 wt % of a polymer with radial or star architecture, wherein polymer has a shear stability index of about 15 to about 50 measured by CEC-L-45-A-99; (b) 0.1 wt % to 5 wt % of a phosphorus-containing acid, salt, or ester; (c) 0.1 wt % to 5 wt % of a dispersant; and (d) an oil of lubricating viscosity,wherein the polymer is obtained from a RAFT or ATRP polymerisation process,wherein the polymer is a polymethacrylate polymer having 7 or more arms, andwherein the polymethacrylate is derived from a monomer composition consisting essentially of:
(a) about 65 wt % to about 95 wt % of an alkyl methacrylate comprising a mixture of alkyl methacrylates having 12 to 15 carbon atoms; (b) about 5 wt % to about 30 wt % of an alkyl methacrylate, wherein the alkyl group of the methacrylate has about 1 to about 9 carbon atoms; and (c) about 0 wt % to about 10 wt % of a nitrogen containing monomer, wherein the polymethacrylate architecture is random or tapered.