Engine oils with improved viscometric performance
AssigneeAfton Chemical Corporation
InventorsArturo Carranza, Neil Harris
Life of this patent
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Abstract
A multi-grade lubricating oil including a (meth)acrylate polymer with at least two distinct molecular weight arms and a blend of heavier and lighter base oils with increased amounts of the heavier base oil to achieve SAE grade performance. The compositions herein achieve SAE certifications as lower CCS viscosities at target kinematic viscosities for multi-grade oils.
Claims18
A multi-grade lubricating oil composition achieving SAE J300 certifications for at least 0W-16, 0W-20, and 5W-20 grade oils with increased amounts of heavier base oils, the multi-grade lubricating oil composition comprising:
- a blend of base oils including at least one lighter base oil having a KV100 of 4.5 cSt or less and at least one heavier base oil having a KV100 of 5.5 cSt or higher, the blend of base oils including at least about 40 weight percent of the at least one heavier base oil based on the total weight of base oils in the blend, wherein a ratio of the lighter base oils to the heavier base oils is 1.55 or less;
- up to about 1 weight percent, based on polymer solids, of a (meth)acrylate copolymer having a hydrocarbyl group in the monomer ester moiety, the (meth)acrylate copolymer having as polymerized monomer units (i) (meth)acrylate monomer units with an intermediate molecular weight hydrocarbyl group in the monomer ester moiety of about 500 to about 700 and (ii) (meth)acrylate monomer units with a high molecular weight hydrocarbyl group in the monomer ester moiety of about 6,000 to about 10,000;
- and
- wherein the at least one lighter base oil is selected from API Group II base oils, API Group III base oils, API Group IV base oils, or combinations thereof and wherein the at least one heavier base oil is selected from API Group III base oils, API Group IV base oils, or combinations thereof.
A method of formulating a multi-grade lubricating oil composition achieving SAE J300 certifications for at least 0W-16, 0W-20, and 5W-20 grade oils with increased amounts of heavier base oils, the method comprising:
- blending an amount of base oil with up to about 1 weight percent, based on polymer solids, of a (meth)acrylate copolymer to form a multi-grade lubricating oil composition that exhibits a kinematic viscosity at 100° C. of about 9.3 mm2/s or less and a CCS viscosity at −35° C. of about 6200 mPa or less and exhibits a kinematic viscosity up to about 1 KV unit lower at a target CCS viscosity as compared to a multi-grade lubricating oil composition without the (meth)acrylate copolymer;
- wherein the base oil include a blend of at least one lighter base oil having a KV100 of 4.5 cSt or less and at least one heavier base oil having a KV100 of 5.5 cSt or higher and the blend of base oils has at least about 40 weight percent of the at least one heavier base oil based on the total weight of base oils in the blend, wherein a ratio of the lighter base oils to the heavier base oils is 1.55 or less;
- the (meth)acrylate copolymer includes as polymerized monomer units (i) (meth)acrylate monomer units with an intermediate molecular weight hydrocarbyl group in the monomer ester moiety of about 500 to about 700 and (ii) (meth)acrylate monomer units with a high molecular weight hydrocarbyl group in the monomer ester moiety of about 6,000 to about 10,000;
- and
- wherein the at least one lighter base oil is selected from API Group II base oils, API Group III base oils, API Group IV base oils, or combinations thereof and wherein the at least one heavier base oil is selected from API Group III base oils, API Group IV base oils, or combinations thereof.
Dependencies are inferred from the claim text.