Lubricating composition containing non-acidic phosphorus compounds
AssigneeChevron U.S.A. Inc.
InventorsJohn A. Zakarian, Michael J. Haire
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Abstract
A lubricating composition with improved storage stability comprising a major amount of an oil of lubricating viscosity, at least one alkali metal borate, at least one polysulfide mixture having at least 40% dihydrocarbyl tetrasulfide or higher sulfides, and at least one non-acidic phosphorus compound comprised of a trihydrocarbyl phosphate and a dihydrocarbyl dithiophosphate derivative is disclosed. In addition to improved storage stability, the composition has improved wear performance when the ratio of polysulfides is controlled.
Claims8
A lubricating composition having enhanced load-carrying properties and enhanced storage stability comprising:
- (a) at least 85% of a base oil of lubricating viscosity;
- and
- (b) no more than about 12% of an additive concentrate the concentrate consisting essentially of:
- (i) from about 20 to about 60 wt % of hydrated alkali metal triborate dispersion;
- (ii) from about 10 to about 50 wt % of a dihydrocarbyl polysulfide component;
- (iii) from about 2 to about 12 wt % of a dihydrocarbyl dithiophosphate derivative;
- and
- (iv) from about 2 to about 12 wt % of a non-acidic phosphorus component.
A lubricating oil concentrate which consists essentially of:
- (a) from about 20 to about 60 wt % of hydrated alkali metal triborate dispersion;
- (b) from about 10 to about 50 wt % of a dihydrocarbyl polysulfide component;
- (c) from about 2 to about 12 wt % of a dihydrocarbyl dithiophosphate derivative;
- and
- (d) from about 2 to about 12 wt % of a non-acidic phosphorus component.
Dependencies are inferred from the claim text.