Gear oil compositions
AssigneeEthyl Corporation
InventorsSanjay Srinivasan, Rolfe J. Hartley
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Abstract
A "cold-clash" gear problem associated with vehicular manual transmissions exposed to the cold is overcome by use of a special all-synthetic gear oil composition. The composition is composed of base oil and specified additive components. The base oil is a blend of di-(2-ethylhexyl)sebacate and three hydrogenated poly-.alpha.-olefin oligomers having kinematic viscosities at 100.degree. C. of about 40, about 8 cSt and about 2 cSt in specified proportions. The additive components comprise an organic sulfur-containing antiwear and/or extreme pressure agent, an organic phosphorus-containing antiwear and/or extreme pressure agent, a copper corrosion inhibitor, a rust inhibitor, a foam inhibitor, and an ashless dispersant. The gear oil has a boron content of about 0.0025 to about 0.07 wt %.
Claims5
An essentially metal-free and essentially halogen-free, boron-containing gear oil lubricant composition which comprises:
- a) base oil consisting essentially of a blend of (1) di-(2-ethylhexyl)sebacate;
- (2) hydrogenated poly-.alpha.-olefin oligomer having a kinematic viscosity at 100.degree. C. of about 40 cSt;
- (3) hydrogenated poly-.alpha.-olefin oligomer having a kinematic viscosity at 100.degree. C. of about 8 cSt;
- and (4) hydrogenated poly-.alpha.-olefin oligomer having a kinematic viscosity at 100.degree. C. of about 2 cSt, in proportions such that for each 100 parts by weight of (2) there are from about 24 to about 40 parts by weight of (1), from about 3 to about 12 parts by weight of (3), and from about 11 to about 20 parts by weight of (4);
- b) about 0.7 to about 7 wt % of at least one oil-soluble organic sulfur-containing antiwear and/or extreme pressure agent having a sulfur content of at least about 20% by weight;
- c) about 0.2 to about 3 wt % of at least one oil-soluble organic phosphorus-containing antiwear and/or extreme pressure agent;
- d) about 0.05 to about 0.35 wt % of at least one oil-soluble copper corrosion inhibitor;
- e) about 0.1 to about 0.8 wt % of at least one oil-soluble rust inhibitor;
- f) about 0.005 to about 0.06 wt % of at least one oil-soluble foam inhibitor;
- and
- g) about 0.15 to about 3 wt % of at least one oil-soluble ashless dispersant;
- all of the foregoing percentages being based on the weight of the total composition, said composition being still further characterized in that the sulfur:phosphorus weight ratio of said composition is in the range of about 8:1 to about 35:1, and in that the boron content of said composition is in the range of about 0.0025 to about 0.07 wt %.
Dependencies are inferred from the claim text.