Engine lubricant containing polyether compounds

Abstract

The present invention relates to lubricant compositions for scooter engines and methods for reducing static friction between ferrous and non-ferrous surfaces as may be found in a wet clutch. The lubricant compositions contain polyether compounds in combination with one or more ash-free friction modifiers.

What is claimed is: 
     
         1 . A lubricant composition comprising:
 a) an oil of lubricating viscosity,   b) a polyether compound,   c) an over-based detergent,   d) a dispersant,   e) optimally, an ash-free friction modifier, and   f) optionally, an antioxidant,   
       wherein the polyether is represented by the formula:
   RO[CH 2 CH(R 1 )O] n A 
 where R is a hydrogen or hydrocarbyl group of 1 to 32 carbon atoms, 
 R 1  is selected from the group consisting of hydrogen, hydrocarbyl groups of 1 to 6 carbon atoms, and mixtures thereof, 
 n is a number from 2 to about 50, and 
 A is selected from the group consisting of hydrogen, R 1 , —R 7 NR 2 R 2 , C═OR 8  and —NR 3 R 3 , where 
 each R 2  is independently hydrogen or a hydrocarbyl group of 1 to 24 carbon atoms, 
 each R 3  is independently hydrogen, a hydrocarbyl group of 1 to 24 carbon atoms, or —[R 4 N(R 5 )] p R 6  where R 4  is C 2 -C 10  alkylene, 
 R 5  and R 6  are independently hydrogen or a hydrocarbyl group of 1 to 6, 
 R 7  and R 8  are independently hydrogen or a hydrocarbyl group of 1 to 6 carbon atoms, and 
 p is a number from 1-7. 
 
     
     
         2 . (canceled) 
     
     
         3 . The lubricating composition of  claim 1 , wherein the polyether compound is a polyetheramine represented by the formula RO[CH 2 CH(R 1 )O] n A, wherein:
 R is a hydrocarbyl group of 2 to 26 carbon atoms,   A is —R 7 NR 2 R 2 ,   each R 2  is independently hydrogen or a hydrocarbyl group of 1 to 24,   R 7  is a hydrocarbyl group of 2 to 4 carbon atoms, and   n is 12 to 36.   
     
     
         4 . The lubricating composition of  claim 1 , comprising the ash-free friction modifier and wherein the ash-free friction modifier is derived from an alpha-hydroxy carboxylic acid. 
     
     
         5 . (canceled) 
     
     
         6 . The lubricating composition of  claim 1 , wherein the ash-free friction modifier is present and is an imide, ester, or amide of tartaric acid. 
     
     
         7 . (canceled) 
     
     
         8 . The lubricating composition of  claim 1 , wherein the over-based detergent comprises a metal containing detergent and wherein the metal is selected from the group consisting of sodium, magnesium and calcium. 
     
     
         9 . (canceled) 
     
     
         10 . The lubricating composition of  claim 1 , wherein the over-based detergent is selected from the group consisting of sulfonates, phenates, salicylates, salixarates and mixtures thereof. 
     
     
         11 . The lubricating composition of  claim 1 , wherein the over-based detergent is substantially free of phenates. 
     
     
         12 . The lubricating composition of  claim 1 , wherein the over-based detergent comprises a calcium sulfonate detergent. 
     
     
         13 . The lubricating composition of  claim 1 , wherein the dispersant is a succinimide dispersant. 
     
     
         14 . The lubricating composition of  claim 1 , wherein the dispersant comprises a borated dispersant. 
     
     
         15 . (canceled) 
     
     
         16 . The lubricating composition of  claim 1 , further comprising a molybdenum containing compound. 
     
     
         17 . The lubricating composition of  claim 1 , wherein the composition is substantially free of a molybdenum containing compound. 
     
     
         18 . The lubricating composition of  claim 1 , wherein the composition is substantially free of phenolic compounds. 
     
     
         19 . The lubricating composition of  claim 1 , wherein the composition comprises:
 a) a major amount of an oil of lubricating viscosity,   b) 0.05 to 3.0 wt. % of the polyether compound,   c) 0.05 to 3.0 wt. % of the over-based detergent,   d) 0.05 to 2.0 wt. % of the ash-free friction modifier, and   e) 0.1 to 12 wt. % of the dispersant.   
     
     
         20 . A method of lubricating a wet clutch comprising, supplying to the wet clutch a lubricating composition of  claim 1 . 
     
     
         21 . The method of  claim 20 , wherein the wet clutch comprises at least one clutch plate having a non-ferrous surface and at least one clutch plate having a ferrous surface. 
     
     
         22 . A method of reducing static friction between a ferrous and non-ferrous surface in a wet clutch, wherein the wet clutch comprises at least one clutch plate having a non-ferrous surface and at least one clutch plate having a ferrous surface, the method comprising supplying between the ferrous and non-ferrous clutch plate surfaces a lubricating composition of  claim 1 . 
     
     
         23 . A method of lubricating an engine comprising supplying to engine a lubricating composition of  claim 1 . 
     
     
         24 . The method of  claim 23 , wherein the engine a 4-stroke engine. 
     
     
         25 . The method of  claim 23 , wherein the engine is an air-cooled engine. 
     
     
         26 . The method of  claim 23 , wherein the lubricating composition does not lubricate a wet clutch. 
     
     
         27 . (canceled) 
     
     
         28 . (canceled) 
     
     
         29 . (canceled) 
     
     
         30 . (canceled) 
     
     
         31 . (canceled) 
     
     
         32 . (canceled) 
     
     
         33 . (canceled)