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US 12,570,918 B2Granted
High performance grease compositions
AssigneeChevron U.S.A. Inc.
InventorAnoop Kumar
Life of this patent
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Abstract
This invention relates to overbased calcium sulfonate complex grease compositions prepared without boric acid and alcohol promotors containing anti-wear, anti-friction, thermal & oxidation stability additives.
Claims19
A method for making a high performance overbased calcium sulfonate complex grease composition prepared without boric acid and without the use of any alcohol-based promotors comprising reacting and mixing
- (a) a primary overbasing material comprising overbased oil-soluble calcium sulfonate having amorphous calcium carbonate dispersed therein;
- (b) a suitable base oil of an amount appropriate to provide a final acceptable product consistency;
- (c) in the presence of a functionalized polymer, a stoichiometric excess of finely divided calcium carbonate as an oil-insoluble solid calcium containing base added to the primary overbasing material and base oil before conversion;
- and
- (d) a doping agent in the form of an extreme-pressure, anti-wear, antioxidant, metal deactivator or polymeric additive, or combination thereof
- wherein the mixture is heated at a rate of less than 1° C. per minute to a temperature of 45-50° C.
3 more elements
A grease composition comprising the reaction product made from components which comprise:
- (a) an overbased oil-soluble calcium sulfonate having amorphous calcium carbonate dispersed therein present in an amount of 18-25 weight percent;
- (b) a base oil present in an amount of 40-70 weight percent;
- (c) a functionalized polymer that acts as a binding medium between the overbased calcium sulfonate and base oil;
- (d) a long chain carboxylic acid having at least 12 carbon atoms present in an amount of 2.0-3.5 weight percent;
- (e) acetic acid present in an amount of 0.5-1.0 weight percent;
- (f) an anionic surfactant comprising a hydrophilic sulfonate head-group and a hydrophobic alkylbenzene tail-group;
- and
- (g) a doping agent selected from the group consisting of extreme-pressure additives, anti-wear additives, antioxidants, metal deactivators, polymeric additives, and combinations thereof present in an amount of 5-12 weight percent;
- wherein the grease composition comprises an insoluble portion having crystalline capsule morphology with a length of 16.4+/−6.4 nm and a width of 5.7+/−1.3 nm, and wherein the grease composition exhibits a weld load of at least 800 kgs according to ASTM D2596 and a high temperature life greater than 280 hours according to ASTM D3527.
6 more elements
Dependencies are inferred from the claim text.