Engine oils with low temperature pumpability
AssigneeAfton Chemical Corporation
InventorsKongsheng Yang, Youhong Wang, Sheng Jiang
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Abstract
A lubricating composition including a polymer blend of a modified styrene-maleic anhydride copolymer and poly(meth)acrylate copolymer effective to maintain a pumpable fluid at low temperatures.
Claims15
A low-temperature stable lubricating composition exhibiting pumpability comprising:
- a base oil of lubricating viscosity;
- about 0.5 to about 1.0 weight percent of a polymeric additive including a blend of an esterified styrene-maleic anhydride copolymer and a poly(meth)acrylate copolymer effective to maintain a pumpable fluid, wherein the polymeric additive includes about 40 weight percent to about 60 weight percent of the esterified styrene-maleic anhydride copolymer based on the total weight of the esterified styrene-maleic anhydride copolymer and the poly(meth)acrylate copolymer;
- and wherein the lubricating composition with the polymeric additive maintains a pumpable fluid at temperature down to −40° C. as evidenced by passing MRV performance pursuant to ASTM D4684 with a viscosity less than 60,000 cP and a yield stress less than 35.
A method for maintaining a pumpable viscosity of a lubricating composition, the method comprising adding to a lubricating composition about 0.5 to about 1 weight percent of a polymeric additive effective to maintain a pumpable fluid as evidenced by a passing MRV performance pursuant to ASTM D4684 at temperatures down to about −40° C.;
- wherein the polymeric additive includes a blend of an esterified styrene-maleic anhydride copolymer and a poly(meth)acrylate copolymer, wherein the polymeric additive includes about 40 weight percent to about 60 weight percent of the esterified styrene-maleic anhydride copolymer based on the total weight of the esterified styrene-maleic anhydride copolymer and the poly(meth)acrylate copolymer.
Dependencies are inferred from the claim text.