Grease compositions

Abstract

Grease compositions may be made from an oil basestock. For example, a grease composition may include: an oil basestock having: a kinematic viscosity (ASTM D445, 40° C.) of from 320 cSt to 520 cSt, a kinematic viscosity (ASTM D445, 100° C.) of from 22 cSt to 36 cSt, a viscosity index (ASTM D2270) of from 80 to 119, a pour point (ASTM D97) of −6° C. or less, and a saturate content (ASTM D7419) of 90 wt % or greater; and from 0.5 wt % to 15 wt % of a thickener, by total weight of the grease composition.

What is claimed is: 
     
         1 . A grease composition comprising:
 an oil basestock having:
 a kinematic viscosity (ASTM D445, 40° C.) of from 320 cSt to 520 cSt, 
 a kinematic viscosity (ASTM D445, 100° C.) of from 22 cSt to 36 cSt, 
 a viscosity index (ASTM D2270) of from 80 to 119, 
 a pour point (ASTM D97) of −6° C. or less, and 
 a saturate content (ASTM D7419) of 90 wt % or greater; and 
   from 0.5 wt % to 15 wt % of a thickener, by total weight of the grease composition.   
     
     
         2 . The grease composition of  claim 1 , wherein the oil basestock is an API Group II basestock. 
     
     
         3 . The grease composition of  claim 2 , wherein the oil basestock further comprises either an API Group I basestock or an API Group IV basestock. 
     
     
         4 . The grease composition of  claim 1 , wherein the oil basestock does not comprise a polyalphaolefin. 
     
     
         5 . The grease composition of  claim 1 , wherein the oil basestock has a concentration in the grease composition of from 60 wt % to 99.5 wt %, by total weight of the grease composition. 
     
     
         6 . The grease composition of  claim 1 , wherein the thickener comprises simple lithium soap. 
     
     
         7 . The grease composition of  claim 1 , wherein the thickener comprises complex lithium soap. 
     
     
         8 . The grease composition of  claim 1 , wherein the thickener comprises simple lithium soap, complex lithium soap, polyurea, an organophilic clay, Teflon, mica gel, silica gel, calcium sulfonate, polytetrafluoroethylene, carbon black, or any combination thereof. 
     
     
         9 . The grease composition of  claim 1 , wherein the thickener comprises a metal soap, and wherein a metal of the metal soap comprises: lithium, calcium, barium, sodium, aluminum, or any combination thereof. 
     
     
         10 . The grease composition of  claim 1 , wherein the oil basestock has:
 a kinematic viscosity (ASTM D445, 40° C.) of from 450 cSt to 520 cSt,   a kinematic viscosity (ASTM D445, 100° C.) of from 32 cSt to 36 cSt,   a pour point (ASTM D97) of −15° C. or less, and   a saturate content (ASTM D7419) of 95 wt % or greater.   
     
     
         11 . The grease composition of  claim 1 , further comprising from 0.5 wt % to 10.0 wt % of a detergent, by total weight of the grease composition. 
     
     
         12 . The grease composition of  claim 1 , from 0.01 wt % to 5 wt % of an antioxidant, by total weight of the grease composition. 
     
     
         13 . The grease composition of  claim 1 , from 0.4 wt % to 2.0 wt % of an antiwear additive, by total weight of the grease composition. 
     
     
         14 . A grease composition comprising:
 an oil basestock having:
 a kinematic viscosity (ASTM D445, 40° C.) of from 460 cSt to 520 cSt, 
 a kinematic viscosity (ASTM D445, 100° C.) of from 32 cSt to 36 cSt, 
 a viscosity index (ASTM D2270) of from 80 to 119, 
 a pour point (ASTM D97) of −15° C. or less, and 
 a saturate content (ASTM D7419) of 98 wt % or greater; and 
   from 6 wt % to 10 wt % of a thickener, by total weight of the grease composition, wherein the thickener comprises a metal soap, and wherein a metal of the metal soap comprises: lithium, calcium, barium, sodium, aluminum, or any combination thereof.   
     
     
         15 . A method comprising:
 heating an oil basestock, wherein the oil basestock has:
 a kinematic viscosity (ASTM D445, 40° C.) of from 320 cSt to 520 cSt, 
 a kinematic viscosity (ASTM D445, 100° C.) of from 22 cSt to 36 cSt, 
 a viscosity index (ASTM D2270) of from 80 to 119, 
 a pour point (ASTM D97) of −6° C. or less, and 
 a saturate content (ASTM D7419) of 90 wt % or greater; and 
   mixing the oil basestock with a thickener and heating the mixture under pressure to form a grease;   adding additional oil basestock to the grease to achieve the desired consistency; and   cooling the grease.   
     
     
         16 . The method of  claim 15 , further comprising: reacting a fatty component and an alkali-metal hydroxide so as to form the thickener through saponification. 
     
     
         17 . The method of  claim 16 , wherein the saponification forms a simple lithium soap, a complex lithium soap, or a combination thereof. 
     
     
         18 . The method of  claim 15 , further comprising:
 (i) dehydrating the mixture after heating the mixture under pressure to form a grease, or   (ii) homogenizing the mixture after adding additional oil basestock to the grease to achieve the desired consistency, or   both (i) and (ii).   
     
     
         19 . The method of  claim 15 , wherein the thickener comprises simple lithium soap, complex lithium soap, polyurea, an organophillic clay, Teflon, mica gel, silica gel, calcium sulfonate, polytetrafluoroethylene, carbon black, or any combination thereof. 
     
     
         20 . The method of  claim 15 , wherein the grease composition comprises from 0.5 wt % to 10 wt % of the thickener, by total weight of the grease composition.