Lubricant compositions having improved dispersancy properties and wear performance

Abstract

There is disclosed an additive composition comprising (a) a highly reactive polyisobutenyl succinimide dispersant, (b) a polyisobutenyl succinimide dispersant, and (c) a grafted olefin copolymer viscosity index improver.

1 . An additive composition comprising:
 (a) a highly reactive polyisobutenyl succinimide dispersant;   (b) a polyisobutenyl succinimide dispersant; and   (c) a grafted olefin copolymer viscosity index improver.   
   
   
       2 . The additive composition of  claim 1 , wherein component (a) comprises a polyisobutenyl succinimide prepared using high vinylidene polyisobutene having a terminal vinylidene content ranging from about 50 to about 85%. 
   
   
       3 . The additive composition of  claim 1 , wherein component (b) is a highly reactive polyisobutenyl succinimide dispersant. 
   
   
       4 . The additive composition of  claim 1 , wherein at least one of component (a) or component (b) is boron-containing. 
   
   
       5 . The additive composition of  claim 1 , wherein component (a) or component (b) is further reacted with at least one acidic reactant selected from the group consisting of maleic acids, maleic anhydrides, and mixtures thereof. 
   
   
       6 . The additive composition of  claim 1 , wherein component (a) is present in an amount ranging from about 7.5 wt. % to about 25 wt. %, relative to the total weight of the additive composition. 
   
   
       7 . The additive composition of  claim 1 , wherein component (a) is present in an amount ranging from about 11 wt. % to about 23 wt. %, relative to the total weight of the additive composition. 
   
   
       8 . The additive composition of  claim 1 , wherein component (b) is present in an amount ranging from about 9.4 wt. % to about 22 wt. %, relative to the total weight of the additive composition. 
   
   
       9 . The additive composition of  claim 1 , wherein component (b) is present in an amount ranging from about 11.25 wt. % to about 13.75 wt. %, relative to the total weight of the additive composition. 
   
   
       10 . A lubricant composition comprising:
 a major amount of a base oil; and   a minor amount of an additive composition comprising:
 (a) a highly reactive polyisobutenyl succinimide dispersant; 
 (b) a polyisobutenyl succinimide dispersant; and 
 (c) a grafted olefin copolymer viscosity index improver. 
   
   
   
       11 . The lubricant composition of  claim 10 , wherein component (a) comprises a polyisobutenyl succinimide prepared using high vinylidene polyisobutene having a terminal vinylidene content ranging from about 50 to about 85%. 
   
   
       12 . The lubricant composition of  claim 10 , wherein at least one of component (a) or component (b) is boron-containing. 
   
   
       13 . The lubricant composition of  claim 10 , wherein component (a) is present in an amount ranging from about 1.2 wt. % to about 3.9 wt. %, relative to the total weight of the lubricant composition. 
   
   
       14 . The lubricant composition of  claim 10 , wherein component (a) is present in an amount ranging from about 1.8 wt. % to about 3.6 wt. %, relative to the total weight of the lubricant composition. 
   
   
       15 . The lubricant composition of  claim 10 , wherein component (b) is present in an amount ranging from about 1.5 wt. % to about 3.5 wt. %, relative to the total weight of the lubricant composition. 
   
   
       16 . The lubricant composition of  claim 10 , wherein component (b) is present in an amount ranging from about 1.7 wt. % to about 2.3 wt. %, relative to the total weight of the lubricant composition. 
   
   
       17 . The lubricant composition of  claim 10  wherein component (c) is present in an amount ranging from about 0.6 wt. % to about 3.0 wt. %, relative to the total weight of the lubricant composition. 
   
   
       18 . The lubricant composition of  claim 10 , wherein component (c) is present in an amount ranging from about 0.8 wt. % to about 2.0 wt. %, relative to the total weight of the lubricant composition. 
   
   
       19 . A method of improving wear performance in a machine, comprising:
 providing to the machine a composition comprising (i) a major amount of a base oil, and (ii) a minor amount of an additive composition comprising:
 (a) a highly reactive polyisobutenyl succinimide dispersant; 
 (b) a polyisobutenyl succinimide dispersant; and 
 (c) a grafted olefin copolymer viscosity index improver. 
   
   
   
       20 . A method of lubricating at least one moving part of a machine, said method comprising:
 contacting the at least one moving part with a lubricant composition comprising (i) a major amount of a base oil; (ii) and a minor amount of an additive composition comprising:
 (a) a highly reactive polyisobutenyl succinimide dispersant; 
 (b) a polyisobutenyl succinimide dispersant; and 
 (c) a grafted olefin copolymer viscosity index improver.