Lithium Complex Grease with Improved Thickener Yield

Abstract

Provided is an improved lithium complex grease. The grease composition has a higher thickener yield, yet good mechanical properties. The grease composition comprises a lubricating oil, a lithium complex thickener and a copolymer, which in one embodiment may comprise styrene and butadiene.

1 . A grease composition having improved thickener yield, comprised of a major amount of a lubricating base oil, and a minor amount of a lithium complex thickener. 
     
     
         2 . The grease composition of  claim 1 , where the amount of thickener and any additives is less than 25 wt % of the grease composition. 
     
     
         3 . The grease composition of  claim 1 , further comprising a copolymer of styrene and butadiene. 
     
     
         4 . The grease composition of  claim 3 , wherein the composition has a thickener yield at least 25% higher than that of a composition with no copolymer. 
     
     
         5 . The grease composition of  claim 3 , wherein the thickener yield is at least 35% higher than that of a composition with no copolymer. 
     
     
         6 . The grease composition of  claim 3 , wherein the thickener yield is at least 50% higher than that of a composition with no copolymer. 
     
     
         7 . The grease composition of  claim 3 , further comprising a copolymer of ethylene and propylene. 
     
     
         8 . The grease composition of  claim 1 , wherein the lithium complex thickener comprises a lithium salt of a carboxylic acid. 
     
     
         9 . The grease composition of  claim 8 , wherein the lithium complex thickener comprises a lithium salt of stearic acid. 
     
     
         10 . The grease composition of  claim 8 , wherein the lithium complex thickener comprises a reaction product of lithium hydroxyl monohydrate and hydroxystearic acid. 
     
     
         11 . The grease composition of  claim 8 , wherein the amount of styrene/butadiene copolymer ranges from about 2-6 weight percent. 
     
     
         12 . The grease composition of  claim 11 , wherein the amount of styrene/butadiene copolymer ranges from about 3-4 weight percent. 
     
     
         13 . The grease composition of  claim 1 , wherein the composition has a worked penetration of at least about 290. 
     
     
         14 . The grease composition of  claim 1 , wherein the composition has a worked penetration of at least about 300. 
     
     
         15 . The grease composition of  claim 3 , wherein the composition has a worked penetration of at least about 310. 
     
     
         16 . The grease composition of  claim 6 , wherein the lithium complex thickener comprises a lithium salt of a carboxylic acid, the amount of styrene/butadiene copolymer ranges from about 2-6 weight percent, and the composition has a worked penetration of at least about 300. 
     
     
         17 . A method of lubricating wheel bearings, which comprises coating the wheel bearings with the grease composition of  claim 1 . 
     
     
         18 . A method of lubricating wheel bearings, which comprises coating the wheel bearings with the grease composition of  claim 16 . 
     
     
         19 . A method of lubricating an automotive chassis, which comprises using the grease composition of  claim 3  to grease the chassis. 
     
     
         20 . A method of lubricating gears, which comprises applying the grease composition of  claim 3  to the gears.