Power transmission fluids with improved friction characteristics

Abstract

Reaction products of maleic and/or succinic acids or anhydrides and primary aliphatic amines are disclosed as effective in reducing the static friction in power transmission fluids.

1 . A power transmission fluid composition which comprises: 
 (a) a major amount of an oil of lubricating viscosity;    (b) an effective amount of a power transmission fluid performance additive package; and    (c) a static friction reducing amount of a member selected from the group consisting of the reaction products of maleic or succinic acid or anhydride or a C 1 -C 6  alkyl substituted maleic or succinic acid or anhydride with a primary aliphatic amine of the formula R-NH 2  wherein R is a C 4 -C 30  hydrocarbyl group.    
     
     
         2 . The composition of  claim 1  wherein the product is derived from a maleic acid or anhydride.  
     
     
         3 . The composition of  claim 1  wherein R is a C 12 -C 22  alkyl.  
     
     
         4 . The composition of  claim 1  wherein there is present 0.01 to 10 wt. % of the reaction product.  
     
     
         5 . The composition of  claim 1  wherein the amine is octadecyl amine.  
     
     
         6 . The composition of  claim 1  wherein the imide is formed from maleic anhydride or methyl succinic anhydride.  
     
     
         7 . A power transmission device containing the composition of  claim 1 .  
     
     
         8 . An automatic transmission apparatus containing the composition of  claim 1.