Star polymer lubricating composition
AssigneeThe Lubrizol Corporation
InventorsBarton J. Schober, Mark C. Davies, Michael R. Sutton, Marina Baum, Daniel C. Visger, David Price, Brent R. Dohner, Mark F. Wilkes
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Abstract
The invention provides a lubricating composition containing (a) 0.001 wt % to 15 wt % of a polymer with radial or star architecture; (b) an overbased detergent; (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.
Claims17
An engine oil lubricating composition comprising:
- (a) 0.075 to 8 wt % of a polymer with radial or star architecture, wherein the polymer is a polymethacrylate, or mixtures thereof;
- wherein the polymethacrylate is derived from a monomer composition consisting essentially of:
- (i) 65 wt % to 95 wt % of an alkyl methacrylate, wherein the alkyl group of the methacrylate has 12 to 18 carbon atoms;
- (ii) 5 wt % to 30 wt % of an alkyl methacrylate, wherein the alkyl group of the methacrylate has 1 to 9 carbon atoms;
- and
- (iii) 0 wt % to 10 wt % of a nitrogen containing monomer;
- and
- wherein the polymer is obtained from a RAFT or ATRP polymerisation process and the polymethacrylate polymeric arm architecture is random;
- and
- wherein the polymer has a weight average molecular weight of 300,000 to 800,000;
- (b) 1 wt % to 4 wt % of an overbased detergent, wherein the overbased detergent comprises one or more of salixarates, phenates, sulphonates, or salicylates;
- (c) 0.25 wt % to 15 wt % of a dispersant, wherein the dispersant comprises one or more of succinimide dispersants;
- and
- (d) an oil of lubricating viscosity, wherein the oil of lubricating viscosity is an API Group II or Group III oil or mixtures thereof;
- wherein the engine oil lubricating composition provides improved viscosity while maintaining Orbahn shear.
A method for lubricating an internal combustion engine comprising supplying to the internal combustion engine a lubricating composition, wherein the lubricating composition comprises:
- (a) 0.075 to 8 wt % of a polymer with radial or star architecture, wherein the polymer is a polymethacrylate, or mixtures thereof;
- wherein the polymethacrylate is derived from a monomer composition consisting essentially of:
- (i) 65 wt % to 95 wt % of an alkyl methacrylate, wherein the alkyl group of the methacrylate has 10 to 20 carbon atoms;
- (ii) 5 wt % to 30 wt % of an alkyl methacrylate, wherein the alkyl group of the methacrylate has 1 to 9 carbon atoms;
- and
- (iii) 0 wt % to 10 wt % of a nitrogen containing monomer;
- and
- wherein the polymer is obtained from a RAFT or ATRP polymerisation process and the polymethacrylate polymeric arm architecture is random;
- and
- wherein the polymer has a weight average molecular weight of 300,000 to 800,000;
- (b) 1 wt % to 4 wt % of an overbased detergent, wherein the overbased detergent comprises one or more of salixarates, phenates, sulphonates, or salicylates;
- (c) 0.25 wt % to 15 wt % of a dispersant, wherein the dispersant comprises one or more of succinimide dispersants;
- and
- (d) an oil of lubricating viscosity.
A method of providing improved viscosity index while maintaining Orbahn shear in an engine oil, comprising lubricating the engine with a lubricating composition comprising:
- (a) 0.075 to 8 wt % of a polymer with radial or star architecture, wherein the polymer is a polymethacrylate, or mixtures thereof;
- wherein the polymethacrylate is derived from a monomer composition consisting essentially of:
- (i) 65 wt % to 95 wt % of an alkyl methacrylate, wherein the alkyl group of the methacrylate has 12 to 18 carbon atoms;
- (ii) 5 wt % to 30 wt % of an alkyl methacrylate, wherein the alkyl group of the methacrylate has 1 to 9 carbon atoms;
- and
- (iii) 0 wt % to 10 wt % of a nitrogen containing monomer;
- and
- wherein the polymer is obtained from a RAFT or ATRP polymerisation process and the polymethacrylate polymeric arm architecture is random;
- and
- wherein the polymer has a weight average molecular weight of 300,000 to 800,000;
- (b) 1 wt % to 4 wt % of an overbased detergent, wherein the overbased detergent comprises one or more of salixarates, phenates, sulphonates, or salicylates;
- (c) 0.25 wt % to 15 wt % of a dispersant, wherein the dispersant comprises one or more of succinimide dispersants;
- and
- (d) an oil of lubricating viscosity, wherein the oil of lubricating viscosity is an API Group II or Group III oil or mixtures thereof.
Dependencies are inferred from the claim text.