Power transmission fluids with enhanced extreme pressure characteristics

Abstract

A power transmission fluid composition for extreme pressure applications. The power transmission fluid includes a base oil, and an additive composition containing an extreme pressure performance improving amount of an ester of phosphonic acid of the formula: where R 1 is a hydrocarbyl group containing from about 8 to about 24 carbon atoms, R 2 and R 3 are independently selected from hydrogen and a hydrocarbyl group containing from about 1 to about 8 carbon atoms, provided that no more than one of R 2 and R 3 is hydrogen, a succinimide dispersant, and, optionally, a metal-based detergent. The optional detergent is substantially devoid of calcium cations.

1 . A power transmission fluid composition, comprising: 
 (a) a base oil, and    (b) an additive composition comprising an extreme pressure performance improving amount of an ester of phosphonic acid of the formula:                          where R 1  is a hydrocarbyl group containing from about 8 to about 24 carbon atoms, R 2  and R 3  are independently selected from hydrogen and a hydrocarbyl group containing from about 1 to about 8 carbon atoms, provided that no more than one of R 2  and R 3  is hydrogen, a succinimide dispersant, and, optionally, a metal-based detergent, wherein the detergent is substantially devoid of calcium cations.    
     
     
         2 . The fluid composition of  claim 1 , wherein the base oil comprises one or more of a natural oil, a mixture of natural oils, a synthetic oil, a mixture of synthetic oils, and a mixture of natural and synthetic oils.  
     
     
         3 . The fluid composition of  claim 2 , wherein the natural oil comprises one or more of a mineral oil, a vegetable oil, and a mixture of mineral oil and vegetable oil.  
     
     
         4 . The fluid composition of  claim 2 , wherein the synthetic oil comprises one or more of an oligomer of an alphaolefin, an ester, an oil derived from a Fischer-Tropsch process, an oil derived from a gas-to-liquid process, and a mixture thereof.  
     
     
         5 . The fluid composition of  claim 1 , wherein the base oil has a kinematic viscosity of from about 2 centistokes to about 10 centistokes at 100° C.  
     
     
         6 . The fluid composition of  claim 1 , wherein the succinimide dispersant comprises a dispersant derived from a polyisobutenyl succinic anhydride (PIBSA) having a number average molecular weight ranging from about 200 to about 2100 as determined by gel permeation chromatography, and a polyalkylene polyamine.  
     
     
         7 . The fluid composition of  claim 6 , wherein the succinimide dispersant is derived from PIBSA and an amine having a ratio of PIBSA to amine ranging from about 1:1 to about 3:1.  
     
     
         8 . The fluid composition of  claim 7 , wherein the succinimide dispersant is post treated with one or more of a phosphorus-based acid, a boron-based acid, a carboxylic acid, an alkylphenol/aldehyde mixture, and a mixture of two or more of the foregoing.  
     
     
         9 . The fluid composition of  claim 1 , wherein the fluid composition comprises from about 0.03 to about 0.25 percent by weight of the ester of phosphonic acid.  
     
     
         10 . The fluid composition of  claim 1 , wherein the fluid composition comprises from about 2 to about 5 percent by weight of the succinimide dispersant.  
     
     
         11 . The fluid composition of  claim 1 , wherein the optional metal-based detergent comprises a detergent selected from one or more of a neutral sodium sulfonate, an overbased sodium sulfonate, a sodium carboxylate, a sodium salicylate, a sodium phenate, a sulfurized sodium phenate, a lithium sulfonate, a lithium carboxylate, a lithium salicylate, a lithium phenate, a sulfurized lithium phenate, a magnesium sulfonate, a magnesium carboxylate, a magnesium salicylate, a magnesium phenate, a sulfurized magnesium phenate, a potassium sulfonate, a potassium carboxylate, a potassium salicylate, a potassium phenate, a sulfurized potassium phenate, a zinc sulfonate, a zinc carboxylate, a zinc salicylate, a zinc phenate, and a sulfurized zinc phenate.  
     
     
         12 . The fluid composition of  claim 1 , wherein the ester of phosphonic acid comprises one or more of dimethyloctadecylphosphonate, methyloctadecylhydrogen phosphonate, bis(2-ethylhexyl)2-ethylhexyl phosphonate, dimethyloctadecenyl phosphonate, diethyl-2-ethyldecylphosphonate, ethylpropyl-1-butylhexadecylphos-phonate, methylethyloctadecylphosphonate, methylbutyl eicosylphosphonate, and dimethylhexatriacontylphosphonate.  
     
     
         13 . The fluid composition of  claim 1 , wherein the additive composition further comprises one or more of a friction modifier, an antioxidant, an antiwear agent, an antifoam agent, and a viscosity index improver.  
     
     
         14 . The fluid composition of  claim 13 , wherein the friction modifier comprises one or more of an aliphatic fatty amine, an ether amine, an alkoxylated aliphatic fatty amine, an alkoxylated ether amine, an oil-soluble aliphatic carboxylic acid, a polyol ester, a fatty acid amide, an imidazoline, a tertiary amine, and a hydrocarbyl succinic anhydride or acid reacted with an ammonia or a primary amine.  
     
     
         15 . The fluid composition of  claim 13 , wherein the antioxidant comprises one or more of a bis-alkylated diphenyl amine, a phenyl alpha amine, a beta naphthyl amine, a sterically hindered phenol, a bisphenol, and a cinnamic acid derivative.  
     
     
         16 . The fluid composition of  claim 13 , wherein the antiwear agent comprises one or more of a phosphate ester and salts thereof, a phosphite ester and salts thereof, and a dialkyldithiophosphoric acid esters and salts thereof.  
     
     
         17 . The fluid composition of  claim 13 , wherein the antifoam agent is one or more of a silicone and a polyacrylate.  
     
     
         18 . The fluid composition of  claim 13 , wherein the viscosity index improver comprises polyisobutylene having a weight average molecular weight ranging from about 700 to about 2,500.  
     
     
         19 . The fluid composition of  claim 1 , wherein the fluid is suitable for use in a transmission employing one or more of a slipping torque converter, a lock-up torque converter, a starting clutch, and one or more shifting clutches.  
     
     
         20 . The fluid composition of  claim 1 , wherein the fluid is suitable for use in a belt, chain, or disk-type continuously variable transmission.  
     
     
         21 . An automatic transmission containing the fluid composition of  claim 1 .  
     
     
         22 . The automatic transmission of  claim 21 , wherein the automatic transmission comprises a continuously variable transmission.  
     
     
         23 . A method of improving extreme pressure characteristics for a transmission fluid comprising: 
 providing a base oil; and    adding to the base oil an additive composition comprising (1) from about 0.01 to about 1.0 weight percent based on a total weight of the base oil and additive composition of an ester of phosphonic acid of the formula:                          where R 1  is a hydrocarbyl group containing from about 8 to about 24 carbon atoms, R 2  and R 3  are independently selected from hydrogen and a hydrocarbyl group containing from about 1 to about 8 carbon atoms, provided that no more than one of R 2  and R 3  is hydrogen, (2) from about 2 to about 5 weight percent based on the total weight of the base oil and additive composition of a succinimide dispersant, and from about 0.0 to about 0.2 weight percent based on the total weight of the base oil and additive composition of a metal-based detergent, wherein the detergent is substantially devoid of calcium cations.    
     
     
         24 . The method of  claim 23 , wherein the base oil comprises one or more of a natural oil, a mixture of natural oils, a synthetic oil, a mixture of synthetic oils, and a mixture of natural and synthetic oils.  
     
     
         25 . The method of  claim 24 , wherein the natural oil comprises one or more of a mineral oil, a vegetable oil, and a mixture of mineral oil and vegetable oil.  
     
     
         26 . The method of  claim 24 , wherein the synthetic oil comprises one or more of an oligomer of an alphaolefin, an ester, an oil derived from a Fischer-Tropsch process, an oil derived from a gas-to-liquid process, and a mixture thereof.  
     
     
         27 . The method of  claim 23 , wherein the base oil has a kinematic viscosity of from about 2 centistokes to about 10 centistokes at 100° C.  
     
     
         28 . The method of  claim 23 , wherein the succinimide dispersant comprises a dispersant derived from a polyisobutenyl succinic anhydride (PIBSA) having a number average molecular weight ranging from about 200 to about 2100 as determined by gel permeation chromatography, and a polyalkylene polyamine.  
     
     
         29 . The method of  claim 28 , wherein the succinimide dispersant is derived from PIBSA and an amine having a ratio of PIBSA to amine ranging from about 1:1 to about 3:1.  
     
     
         30 . The method of  claim 29 , wherein the succinimide dispersant is post treated with one or more of a phosphorus-based acid, a boron-based acid, a carboxylic acid, an alkylphenol/aldehyde mixture, and a mixture of two or more of the foregoing.  
     
     
         31 . The method of  claim 23 , wherein the base oil comprises from about 0.03 to about 0.25 percent by weight of the ester of phosphonic acid based on the total weight of the base oil and additive composition.  
     
     
         32 . The method of  claim 23 , wherein the metal-based detergent comprises a detergent selected from one or more of a neutral sodium sulfonate, an overbased sodium sulfonate, a sodium carboxylate, a sodium salicylate, a sodium phenate, a sulfurized sodium phenate, a lithium sulfonate, a lithium carboxylate, a lithium salicylate, a lithium phenate, a sulfurized lithium phenate, a magnesium sulfonate, a magnesium carboxylate, a magnesium salicylate, a magnesium phenate, a sulfurized magnesium phenate, a potassium sulfonate, a potassium carboxylate, a potassium salicylate, a potassium phenate, a sulfurized potassium phenate, a zinc sulfonate, a zinc carboxylate, a zinc salicylate, a zinc phenate, and a sulfurized zinc phenate.  
     
     
         33 . The method of  claim 23 , wherein the ester of phosphonic acid comprises one or more of dimethyloctadecylphosphonate, methyloctadecylhydrogen phosphonate, bis(2-ethylhexyl) 2-ethylhexyl phosphonate, dimethyloctadecenylphosphonate, diethyl-2-ethyldecylphosphonate, ethylpropyl-1-butylhexadecylphosphonate, methyl-ethyloctadecylphosphonate, methylbutyl eicosyl-phosphonate, and dimethylhexatria-contylphosphonate.  
     
     
         34 . The method of  claim 23 , wherein the additive composition further comprises one or more of a friction modifier, an antioxidant, an antiwear agent, an antifoam agent, and a viscosity index improver.  
     
     
         35 . The method of  claim 34 , wherein the friction modifier comprises one or more of an aliphatic fatty amine, an ether amine, an alkoxylated aliphatic fatty amine, an alkoxylated ether amine, an oil-soluble aliphatic carboxylic acid, a polyol ester, a fatty acid amide, an imidazoline, a tertiary amine, and a hydrocarbyl succinic anhydride or acid reacted with ammonia or a primary amine.  
     
     
         36 . The method of  claim 34 , wherein the antioxidant comprises one or more of a bis-alkylated diphenyl amine, a phenyl alpha amine, beta naphthyl amine, a sterically hindered phenol, a bisphenol, and a cinnamic acid derivative.  
     
     
         37 . The method of  claim 34 , wherein the antiwear agent comprises one or more of a phosphate ester and salts thereof, a phosphite ester and salts thereof, and a dialkyldithiophosphoric acid ester and salts thereof.  
     
     
         38 . The method of  claim 34 , wherein the antifoam agent is one or more of a silicone and a polyacrylate.  
     
     
         39 . The method of  claim 34 , wherein the viscosity index improver comprises polyisobutylene having a weight average molecular weight ranging from about 700 to about 2,500.  
     
     
         40 . The method of  claim 23 , wherein the fluid is suitable for use in a transmission employing one or more of a slipping torque converter, a lock-up torque converter, a starting clutch, and one or more shifting clutches.  
     
     
         41 . The method of  claim 23 , wherein the fluid is suitable for use in a belt, chain, or disk-type continuously variable transmission.  
     
     
         42 . An additive concentrate for a transmission fluid or gear lubricant, the additive concentrate comprising: 
 (a) a base oil carrier fluid,    (b) an extreme pressure performance improving amount of an ester of phosphonic acid of the formula:                          where R 1  is a hydrocarbyl group containing from about 8 to about 24 carbon atoms, R 2  and R 3  are independently selected from hydrogen and a hydrocarbyl group containing from about 1 to about 8 carbon atoms, provided that no more than one of R 2  and R 3  is hydrogen,    (c) a succinimide dispersant, and, optionally,    (d) a metal-based detergent, wherein the detergent is substantially devoid of calcium cations.    
     
     
         43 . The additive concentrate of  claim 42 , wherein the base oil comprises one or more of a natural oil, a mixture of natural oils, a synthetic oil, a mixture of synthetic oils, and a mixture of natural and synthetic oils.  
     
     
         44 . The additive concentrate of  claim 43 , wherein the natural oil comprises one or more of a mineral oil, a vegetable oil, and a mixture of mineral oil and vegetable oil.  
     
     
         45 . The additive concentrate of  claim 43 , wherein the synthetic oil comprises one or more of an oligomer of an alphaolefin, an ester, an oil derived from a Fischer-Tropsch process, an oil derived from a gas-to-liquid process, and a mixture thereof.  
     
     
         46 . The additive concentrate of  claim 42 , wherein the base oil has a kinematic viscosity of from about 2 centistokes to about 10 centistokes at 100° C.  
     
     
         47 . The additive concentrate of  claim 42 , wherein the succinimide dispersant comprises a dispersant derived from a polyisobutenyl succinic anhydride (PIBSA) having a number average molecular weight ranging from about 200 to about 2100 as determined by gel permeation chromatography, and a polyalkylene polyamine.  
     
     
         48 . The additive concentrate of  claim 47 , wherein the succinimide dispersant is derived from PIBSA and an amine having a ratio of PIBSA to amine ranging from about 1:1 to about 3:1.  
     
     
         49 . The additive concentrate of  claim 42 , wherein the succinimide dispersant is post treated with a one or more of a phosphorus-based acid, a boron-based acid, a carboxylic acid, an alkylphenol/aldehyde mixture, and a mixture of two or more of the foregoing.  
     
     
         50 . The additive concentrate of  claim 42 , wherein the additive concentrate comprises from about 0.03 to about 0.25 percent by weight of the ester of phosphonic acid.  
     
     
         51 . The additive concentrate of  claim 42 , wherein the additive concentrate comprises from about 2 to about 5 percent by weight of the succinimide dispersant.  
     
     
         52 . The additive concentrate of  claim 42 , wherein the optional metal-based detergent comprises a detergent selected from one or more of a neutral sodium sulfonate, an overbased sodium sulfonate, a sodium carboxylate, a sodium salicylate, a sodium phenate, a sulfurized sodium phenate, a lithium sulfonate, a lithium carboxylate, a lithium salicylate, a lithium phenate, a sulfurized lithium phenate, a magnesium sulfonate, a magnesium carboxylate, a magnesium salicylate, a magnesium phenate, a sulfurized magnesium phenate, a potassium sulfonate, a potassium carboxylate, a potassium salicylate, a potassium phenate, a sulfurized potassium phenate, a zinc sulfonate, a zinc carboxylate, a zinc salicylate, a zinc phenate, and a sulfurized zinc phenate.  
     
     
         53 . The additive concentrate of  claim 42 , wherein the ester of phosphonic acid comprises one or more of dimethyloctadecylphosphonate, methyloctadecylhydrogen phosphonate, bis(2-ethylhexyl)2-ethylhexyl phosphonate, dimethyloctadecenyl-phosphonate, diethyl-2-ethyldecylphosphonate, ethylpropyl-1-butylhexadecylphos-phonate, methylethyloctadecylphosphonate, methylbutyl eicosyl-phosphonate, and dimethylhexatriacontylphosphonate.  
     
     
         54 . The additive concentrate of  claim 42 , wherein the additive concentrate further comprises one or more of a friction modifier, an antioxidant, an antiwear agent, an antifoam agent, and a viscosity index improver.  
     
     
         55 . The additive concentrate of  claim 54 , wherein the friction modifier comprises one or more of an aliphatic fatty amine, an ether amine, an alkoxylated aliphatic fatty amine, an alkoxylated ether amine, an oil-soluble aliphatic carboxylic acid, a polyol ester, a fatty acid amide, an imidazoline, a tertiary amine, and a hydrocarbyl succinic anhydride or acid reacted with ammonia or a primary amine.  
     
     
         56 . The additive concentrate of  claim 54 , wherein the antioxidant comprises one or more of a bis-alkylated diphenyl amine, a phenyl alpha amine, a beta naphthyl amine, a sterically hindered phenol, a bisphenol, and a cinnamic acid derivative.  
     
     
         57 . The additive concentrate of  claim 54 , wherein the antiwear agent comprises one or more of a phosphate ester and salts thereof, a phosphite ester and salts thereof, and a dialkyldithiophosphoric acid ester and salts thereof.  
     
     
         58 . The additive concentrate of  claim 54 , wherein the antifoam agent is one or more of a silicone and a polyacrylate.  
     
     
         59 . The additive concentrate of  claim 54 , wherein the viscosity index improver comprises polyisobutylene having a weight average molecular weight ranging from about 700 to about 2,500.  
     
     
         60 . An automatic transmission fluid comprising a base oil and from about 5 to 20 wt. % of the additive concentrate of  claim 42  based on a total weight of the fluid.  
     
     
         61 . A vehicle comprising an engine and a transmission, the transmission including the automatic transmission fluid of  claim 60 .  
     
     
         62 . A vehicle comprising a differential, the differential including a lubricant containing an additive concentrate of  claim 42.