Limited Slip Friction Modifiers for Differentials

Abstract

An object of the present invention is to provide a lubricant composition for a limited slip differential comprising a major amount of an oil of lubricating viscosity and an oil soluble compound, as well as a method of using the same in a differential. The compound can be of formula R′NH(CH 2 ) 3 NHCOR″, wherein R′ can be a C 8-28 amine, and —COR″ can be derived from a C 8-28 acid.

What is claimed is: 
     
         1 . A lubricant for limited slip differentials comprising (a) an oil of lubricating viscosity, and (b) at least one oil soluble compound comprising the condensation product of (1) an N-substituted 1,3-diaminopropane, wherein the N-substituent is derived from a C 8-28  amine, and (2) a C 8-28  acid. 
     
     
         2 . The lubricant of  claim 1  wherein the condensation product comprises a compound of formula R′NH(CH 2 ) 3 NHCOR″, wherein R′ is the N-substituent derived from the C 8-28  amine of (1), and wherein —COR″ is derived from the C 8-28  acid of (2). 
     
     
         3 . The lubricant of  claim 1  wherein the C 8-28  amine of (1) is a fatty amine and the C 8-28  acid of (2) is at least one of a fatty acid or fatty acid chloride. 
     
     
         4 . The lubricant of  claim 1  wherein R′ is derived from a C 18  fatty amine and —COR″ is derived from a C 18  fatty acid. 
     
     
         5 . The lubricant of  claim 1  wherein R′ is derived from at least one of soya amine, oleyl amine, tallow amine, or cocoamine. 
     
     
         6 . The lubricant of  claim 1  wherein —COR″ is derived from myristic acid, palmitic acid, behenic acid, eruicic acid, oleic acid, stearic acid, linoleic acid, and lauric acid. 
     
     
         7 . The lubricant of comprising the condensation product of N-oleyl-1,3-diaminopropane and oleic acid. 
     
     
         8 . A method of providing limited slip performance comprising the step of introducing the lubricating composition of  claim 1  to a limited slip differential and operating the limited slip differential. 
     
     
         9 . The use of a lubricant according to  claim 1  for limited slip performance in a limited slip differential.