Oil composition and its use in a transmission

Abstract

This invention relates to a lubricating composition containing (a) an oil soluble phosphorus amine salt; (b) about 0.0001 wt % to about 0.5 wt % of a metal containing detergent package comprising a phenate and a sulphonate; (c) a dispersant; (d) a dispersant viscosity modifier; (e) a metal deactivator; and (f) an oil of lubricating viscosity, wherein the lubricating composition contains less than about 0.25 wt % of a metal dialkyldithiophosphate. The invention further relates to a method of lubricating a transmission by employing the lubricating composition.

1 . A lubricating composition comprising: 
 (a) an oil soluble phosphorus amine salt;    (b) about 0.0001 wt % to about 5 wt % of a metal containing detergent package comprising a phenate and a sulphonate;    (c) a dispersant;    (d) a dispersant viscosity modifier;    (e) a metal deactivator; and    (f) an oil of lubricating viscosity,    wherein the lubricating composition contains less than about 0.25 wt % of a metal dialkyldithiophosphate.    
   
   
       2 . The lubricating composition of  claim 1 , wherein phosphorus amine salt is selected from the group consisting of phosphoric acid esters and salts thereof; dialkyldithiophosphoric acid esters and salts thereof; amine salts of phosphites; and amine salts of phosphorus-containing carboxylic esters, ethers, and amides; and mixtures thereof.  
   
   
       3 . The lubricating composition of  claim 1 , wherein phosphorus amine salt comprises an amine salt of a phosphorus acid ester.  
   
   
       4 . The lubricating composition of  claim 1 , wherein the phosphorus amine salt comprises an amine with C 11  to C 14  tertiary alkyl primary groups or mixtures thereof.  
   
   
       5 . The lubricating composition of  claim 1 , wherein the phosphorus amine salt comprises an amine with C 14  to C 18  tertiary alkyl primary amines or mixtures thereof.  
   
   
       6 . The lubricating composition of  claim 1 , wherein the phosphorus amine salt comprises an amine with C 18  to C 22  tertiary alkyl primary amines or mixtures thereof.  
   
   
       7 . The lubricating composition of  claim 1 , wherein the metal containing detergent package comprises at least 50 wt % of a phenate.  
   
   
       8 . The lubricating composition of  claim 1 , wherein the metal containing detergent comprises calcium sulphonate and calcium phenate.  
   
   
       9 . The lubricating composition of  claim 1 , wherein the dispersant comprises a N-substituted long chain alkyl and/or alkenyl succinimide.  
   
   
       10 . The lubricating composition of  claim 9 , wherein the alkenyl succinimide has an alkenyl group with a number average molecular weight of about 500 to about 2500.  
   
   
       11 . The lubricating composition of  claim 1 , wherein the metal deactivator is selected from the group consisting of benzotriazoles or derivatives thereof, 1,2,4-triazoles, benzimidazoles, 2-alkyldithiobenzimidazoles, 2-alkyldithiobenzothiazoles, 2-(N,N-dialkyldithiocarbamoyl)benzothiazoles, 2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles, 2,5-bis(N,N-dialkyldithio carbamoyl)-1,3,4-thiadiazoles, 2-alkyldithio-5-mercapto thiadiazoles and mixtures thereof.  
   
   
       12 . The lubricating composition of  claim 1 , wherein the metal deactivator comprises 2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles, benzotriazoles or derivatives thereof or mixtures thereof.  
   
   
       13 . The lubricating composition of  claim 1 , wherein the metal hydrocarbyl dithiophosphate is present from about 0 ppm to 1000 ppm.  
   
   
       14 . The lubricating composition of  claim 1 , wherein the lubricating composition is free of a metal hydrocarbyl dithiophosphate.  
   
   
       15 . The lubricating composition of  claim 1 , wherein the dispersant viscosity modifier comprises amine functionalised polyolefins, a poly(meth)acrylate functionalised with an a nitrogen containing compound, an esterified polymer derived from monomers comprising: (i) a vinyl aromatic monomer; and (ii) an unsaturated carboxylic acid or derivatives thereof, or mixtures thereof.  
   
   
       16 . The lubricating composition of  claim 1 , wherein the lubricating composition comprises: 
 (a) about 0.001 wt % to about 5 wt % of an oil soluble phosphorus amine salt;    (b) about 0.01 wt % to about 4 wt % of a metal containing detergent package comprising a phenate and a sulphonate;    (c) about 0.01 wt % to about 4 wt % of a dispersant;    (d) about 0.01 wt % to about 24 wt % of a dispersant viscosity modifier;    (e) about 0.001 wt % to about 1 wt % of a metal deactivator; and    (f) about 44 wt % to about 99.9 wt % of an oil of lubricating viscosity,    wherein the lubricating composition is free of a metal dialkyldithiophosphate.    
   
   
       17 . The lubricating composition of  claim 1 , wherein the lubricating composition is a transmission oil, a driveshaft oil, a gear oil, an axle oil or mixtures thereof.  
   
   
       18 . A method of lubricating a synchronised transmission comprising: 
 (i) employing a lubricating composition comprising:    (a) an oil soluble phosphorus amine salt;    (b) about 0.0001 wt % to about 5 wt % of a metal containing detergent package comprising a phenate and a sulphonate;    (c) a dispersant;    (d) a dispersant viscosity modifier;    (e) a metal deactivator; and    (f) an oil of lubricating viscosity,    wherein the lubricating composition contains less than about 0.25 wt % of a metal dialkyldithiophosphate; and 
 (ii) lubricating a synchronised transmission with said lubricating composition.  
   
   
   
       19 . The method of  claim 18 , wherein the transmission is a manual transmission.  
   
   
       20 . A method of lubricating a non-synchronised transmission comprising: 
 (i) employing a lubricating composition comprising:    (a) an oil soluble phosphorus amine salt;    (b) about 0.0001 wt % to about 5 wt % of a metal containing detergent package comprising a phenate and a sulphonate;    (c) a dispersant and/or a dispersant viscosity modifier;    (d) a metal deactivator; and    (e) an oil of lubricating viscosity,    wherein the lubricating composition contains less than about 0.25 wt % of a metal dialkyldithiophosphate; and 
 (ii) lubricating a non-synchronised transmission with said lubricating composition.  
   
   
   
       21 . A lubricating composition comprising: 
 (a) about 0.05 wt % to about 2.5 wt % of an oil soluble phosphorus amine salt;    (b) about 0.05 wt % to about 3 wt % of a metal containing detergent package comprising a phenate and a sulphonate;    (c) 0.1 wt % to about 2 wt % of a dispersant;    (d) about 0.1 wt % to about 21 wt % of a dispersant viscosity modifier;    (e) about 0.001 wt % to about 1 wt % of a metal deactivator; and    (f) about 64 wt % to about 99.7 wt % of an oil of lubricating viscosity,    wherein the lubricating composition is free of a metal dialkyldithiophosphate.