Functionalized polymer as grease additive

A concentrate consisting essentially of:

• about 3 to about 30 weight percent of a polyolefin having grafted carboxylic acid functionality, wherein the grafted polyolefin is an α-olefin/diene copolymer or a hydrogenated α-olefin/diene copolymer, said polyolefin having a number average molecular weight of at least about 50,000 and said polyolefin containing about 0.001 to about 5 weight percent carboxylic acid functionality;
• a co-thickening agent selected from the group consisting of simple metal soap thickeners, soap complexes, non-soap thickeners, oils functionalized by grafting reaction with ethylenically unsaturated mono- or di-carbaoxylic acids having 4 to 10 carbon atoms, and metal salts of such acid-functionalized oils;
• and
• about 5 to about 98 percent by weight of an oil of lubricating viscosity.

A grease composition comprising:

• (a) an oil of lubricating viscosity;
• (b) about 0.1 to about 10 weight percent of a polymer comprising at least one 1-olefin monomer of 2 to 18 carbon atoms and a diene, or a hydrogenated polymer of such monomers, said polymer having grafted carboxylic acid functionality derived from at least one ethylenically unsaturated mono- or di-carboxylic acid having 4 to 10 carbon atoms, said polymer having a number average molecular weight of at least 50,000;
• (c) a metal ion selected from the group consisting of alkali metals, alka-line earth metals, and aluminum capable of interacting with the acid functionality of said polyolefin to cause association among the acid groups;
• and
• (d) a grease co-thickcening agent selected from the group consisting of simple metal soap thickeners, soap complexes, non-soap thickeners, oils functionalized by grafting reaction with ethylenically unsaturated mono- or di-carboxylic acids having 4 to 10 carbon atoms, and metal salts of such acid-functionalized oils;
• the polymer of (b) being present in an amount sufficient to provide 0.001 to 0.1 weight percent carboxylic acid functionality to the composition and to improve the water spray-off performance of the grease composition as measured by ASTM D-4049;
• said polymer having been combined with the other components under grease-forming conditions of heating and mixing to form the grease composition.

A grease composition comprising:

• (a) a gelled overbased mateal dispersed in
• (b) an oil of lubricating viscosity;
• and
• (c) about 0.1 to about 10 weight percent of a polyolefin containing grafted carboxylic acid functionality wherein the polyolefin is an α-olefin/diene copolymer or a hydrogenated α-olefin/diene copolymer, present in an amount sufficient to increase the viscosity of the composition, wherein the polymer has a number average molecular weight of at least about 50,000;
• said polymer having been combined with the other components under grease-forming conditions of heating and mixing to form the grease composition;
• wherein the amount of carboxylic acid functionality in the composition is about 0.001 to about 0.1 weight percent.

A method for preparing a grease, comprising combining under grease-forming conditions of heating and mixing

• (a) an oil of lubricating viscosity;
• (b) about 0.1 to about 10 weight percent of a polyolefin having grafted carboxylic acid functionality, wherein the grafted polyolefin is an α-olefin/diene copolymer or a hydrogenated α-olefin/diene copolymer, said polyolefin having a number average molecular weight of at least about 50,000;
• (c) a metallic species selected from the group consisting of alkali metals, alkaline earth metals, and aluminum, capable of interacting with the acid functionality of said polyolefin to cause association among the acid groups;
• and
• (d) a co-thickening agent selected from the group consisting of simple metal soap thickeners, soap complexes, non-soap thickeners, oils functionalized by grafting reaction with ethylenically unsaturated mono- or di-carboxylic acids having 4 to 10 carbon atoms, and metal salts of such acid-functionalized oils
• wherein the amount of carboxylic acid functionality derived from the grafted polymer in the resulting grease composition is about 0.001 to about 0.1 weight percent.