Star polymer lubricating composition
AssigneeThe Lubrizol Corporation
InventorsMark R. Baker, Marina Baum, Barton J. Schober
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Abstract
The invention provides a lubricating composition containing (a) a polymer derived from greater than 50 wt % or more of a non-diene monomer, wherein the polymer has a weight average molecular weight of about 2000 to about 200,000, and wherein the polymer has a shear stability index of about 0 to about 25; (b) a phosphorus-containing acid, salt, or ester; (c) an extreme pressure agent, other than a phosphorus-containing acid, salt, or ester; and (d) an oil of lubricating viscosity. The invention further provides a method for lubricating a mechanical device with the lubricating composition.
Claims18
A lubricating composition comprising:
- (a) about 0.1 wt % to about 25 wt % of a polymer derived from greater than 50 wt % of more of a non-diene monomer, wherein the polymer has radial or star architecture;
- (b) about 0.1 wt % to about 5 wt % of a phosphorus-containing acid, salt, or ester, wherein the phosphorus-containing acid, salt, or ester comprises an amine salt of a phosphorus acid or ester;
- (c) about 0.1 wt % to about 8 wt % of an extreme pressure agent, wherein the extreme pressure agent, other than a phosphorus-containing acid, salt, or ester comprises a boron-containing compound, wherein the boron compound comprises a borate ester, a borate alcohol, a borated dispersant or mixtures thereof;
- 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 having 7 or more arms, and wherein, the polymethacrylate is derived from a monomer composition comprising
- (a) about 50 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 40 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 has a polymeric arm architecture that is random.
A method for lubricating a mechanical device comprising a supplying to the mechanical device a lubricating composition, wherein the mechanical device is a gear, a gearbox or a manual transmission, and wherein the lubricating composition comprises:
- (a) about 0.1 wt % to about 25 wt % of a polymer derived from greater than 50 wt % or more of a non-diene monomer, wherein the polymer has radial or star architecture;
- (b) about 0.1 wt % to about 5 wt % of a phosphorus-containing acid, salt, or ester, wherein the phosphorus-containing acid, salt, or ester comprises an amine salt of a phosphorus acid or ester;
- (c) about 0.1 wt % to about 8 wt % of an extreme pressure agent, wherein the extreme pressure agent, comprises a boron-containing compound, wherein the boron compound comprises a borate ester, a borate alcohol, a borated dispersant or mixtures thereof;
- and
- (d) an oil of lubricating viscosity,
- wherein the polymer is obtained from a RAFT or ATRP polymerization process, wherein the polymer is a polymethacrylate having 7 or more arms, and wherein the polymethacrylate is derived from a monomer composition comprising
- (a) about 50 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 40 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 has a polymeric arm architecture that is random.
Dependencies are inferred from the claim text.