Lubricating oil compositions and methods for improving fuel economy in an internal combustion engine using same

Abstract

A lubricating oil composition is provided which comprises (a) an oil of lubricating viscosity having a kinematic viscosity of about 2 to 10.5 cSt at 100° C. and (b) a friction modifying effective amount of an ashless friction modifier comprising a reaction product of a C 4 to about C 75 fatty acid ester and an alkanolamine. Particularly preferred is a lubricating oil composition comprising (a) an oil of lubricating viscosity having a kinematic viscosity of about 2 to 10.5 cSt at 100° C. and comprising about 55 to about 85 weight percent of a first lubricating oil, and about 15 to about 45 weight percent of a second lubricating oil wherein the kinematic viscosity of the second lubricating oil is lower than the kinematic viscosity of the first lubricating oil at 100° C.; and (b) about 0.5 to about 5.0 weight percent, based on the total weight of the lubricating oil composition, of an ashless friction modifier comprising a reaction product of a C 4 to about C 75 fatty acid ester and an alkanolamine.

What is claimed is:  
     
         1 . A lubricating oil composition comprising (a) an oil of lubricating viscosity having a kinematic viscosity of about 2 to 10.5 cSt at 100° C. and (b) a friction modifying effective amount of an ashless friction modifier comprising a reaction product of a C 4  to about C 75  fatty acid ester and an alkanolamine.  
     
     
         2 . The lubricating oil composition of  claim 1  wherein component (a) further comprises (i) a first lubricating oil comprising an oil of lubricating viscosity having a kinematic viscosity of 9.3 to about 16.3 cSt at a temperature of 100° C and (ii) a second lubricating oil comprising an oil of lubricating viscosity having a kinematic viscosity of about 2 to less than or equal to 9.3 cSt at a temperature of 100° C., wherein the kinematic viscosity of the second lubricating oil is lower than the kinematic viscosity of the first lubricating oil at 100° C.  
     
     
         3 . The lubricating oil composition of  claim 1  wherein the fatty acid ester is an about C 6  to about C 24  fatty acid ester.  
     
     
         4 . The lubricating oil composition of  claim 1  wherein the fatty acid ester is a glycerol fatty acid ester.  
     
     
         5 . The lubricating oil composition of  claim 4  wherein the glycerol fatty acid ester is selected from the group consisting of palm, olive, cotton seed, castor, peanut, tallow, lard, whale, sunflower, soybean, coconut, palm kernel oils and combinations thereof.  
     
     
         6 . The lubricating oil composition of  claim 1  wherein the alkanolamine possesses the general formula  
       RN(R′OH) 2-a H a    
       wherein R is hydrogen or an aminoalkyl group with the alkyl having from one to about six carbon atoms, R′ is a hydrocarbyl having from about two to about six carbon atoms and “a” is 0 or 1.  
     
     
         7 . The lubricating oil composition of  claim 6  wherein the alkanolamine is selected from the group consisting of monoethanolamine, diethanolamine, propanolamine, isopropanolamine, dipropanolamine, di-isopropanolamine, butanolamines, aminoethylaminoethanol and combinations thereof.  
     
     
         8 . The lubricating oil composition of  claim 1  wherein the friction modifier is the reaction product of a glycerol fatty acid ester and an alkanolamine.  
     
     
         9 . The lubricating oil composition of  claim 2  wherein the friction modifier is the reaction product of a glycerol fatty acid ester and an alkanolamine.  
     
     
         10 . The lubricating oil composition of  claim 1  wherein the friction modifier is the reaction product of a fatty acid ester selected from the group consisting of palm, olive, cotton seed, castor, peanut, tallow, lard, whale, sunflower, soybean, coconut, palm kernel oils and combinations thereof and an alkanolamine selected from the group consisting of monoethanolamine, diethanol amine, propanolamine, isopropanolamine, dipropanolamine, di-isopropanolamine, butanolamines, aminoethylaminoethanol and combinations thereof.  
     
     
         11 . The lubricating oil composition of  claim 1  wherein component (a) is an oil of lubricating viscosity having a kinematic viscosity of about 2 to less than 10.0 cSt at 100° C.  
     
     
         12 . The lubricating oil composition of  claim 1  wherein component (a) is an oil of lubricating viscosity having a kinematic viscosity of about 3.8 to less than or equal to 9.3 cSt at 100° C.  
     
     
         13 . The lubricating oil composition of  claim 1  wherein the amount of the ashless friction modifier present in the lubricating oil composition is 1 to about 4.5 weight percent, based on the total weight of the lubricating oil composition.  
     
     
         14 . The lubricating oil composition of  claim 11  wherein the amount of the ashless friction modifier present in the lubricating oil composition is 1 to about 4.5 weight percent, based on the total weight of the lubricating oil composition.  
     
     
         15 . A method of improving the fuel economy of an internal combustion engine which comprises operating the engine with a lubricating oil composition comprising (a) an oil of lubricating viscosity having a kinematic viscosity of about 2 to 10.5 cSt at 100° C. and (b) a friction modifying effective amount of an ashless friction modifier comprising a reaction product of a C 4  to about C 75  fatty acid ester and an alkanolamine.  
     
     
         16 . The method of  claim 15  wherein component (a) further comprises (i) a first lubricating oil comprising an oil of lubricating viscosity having a kinematic viscosity of 9.3 to about 16.3 cSt at a temperature of 100° C. and (ii) a second lubricating oil comprising an oil of lubricating viscosity having a kinematic viscosity of about 2 to less than or equal 9.3 cSt at a temperature of 100° C., wherein the kinematic viscosity of the second lubricating oil is lower than the kinematic viscosity of the first lubricating oil at 100° C.  
     
     
         17 . The method of  claim 15  wherein the fatty acid ester is an about C 6  to about C 24  fatty acid ester.  
     
     
         18 . The method of  claim 15  wherein the fatty acid ester is a glycerol fatty acid ester.  
     
     
         19 . The method of  claim 18  wherein the glycerol fatty acid ester is selected from the group consisting of palm, olive, cotton seed, castor, peanut, tallow, lard, whale, sunflower, soybean, coconut, palm kernel oils and combinations thereof.  
     
     
         20 . The method of  claim 15  wherein the alkanolamine possesses the general formula  
       RN(R′OH) 2-a H a    
       wherein R is hydrogen or an aminoalkyl group with the alkyl having from one to about six carbon atoms, R′ is a hydrocarbyl having from about two to about six carbon atoms and “a” is 0 or 1.  
     
     
         21 . The method of  claim 19  wherein the alkanolamine is selected from the group consisting of monoethanolamine, diethanolamine, propanolamine, isopropanolamine, dipropanolamine, di-isopropanolamine, butanolamines, aminoethylaminoethanol and combinations thereof.  
     
     
         22 . The method of  claim 15  wherein the friction modifier is the reaction product of a fatty acid ester selected from the group consisting of palm, olive, cotton seed, castor, peanut, tallow, lard, whale, sunflower, soybean, coconut, palm kernel oils and combinations thereof and an alkanolamine selected from the group consisting of monoethanolamine, diethanolamine, propanolamine, isopropanolamine, dipropanolamine, di-isopropanolamine, butanolamines, aminoethylaminoethanol and combinations thereof  
     
     
         23 . The method of  claim 15  wherein component (a) is an oil of lubricating viscosity having a kinematic viscosity of about 2 to less than 10.0 cSt at 100° C.  
     
     
         24 . The method of  claim 15  wherein the amount of the ashless friction modifier present in the lubricating oil composition is 1 to about 4.5 weight percent, based on the total weight of the lubricating oil composition.  
     
     
         25 . A lubricating oil composition comprising (a) an oil of lubricating viscosity having a kinematic viscosity of about 2 to 10.5 cSt at 100° C. and comprising about 55 to about 85 weight percent of a first lubricating oil, and about 15 to about 45 weight percent of a second lubricating oil wherein the kinematic viscosity of the second lubricating oil is lower than the kinematic viscosity of the first lubricating oil at 100° C.; and (b) about 0.5 to about 5.0 weight percent, based on the total weight of the lubricating oil composition, of an ashless friction modifier comprising a reaction product of a C 4  to about C 75  fatty acid ester and an alkanolamine.  
     
     
         26 . The lubricating oil composition of  claim 25  wherein the first lubricating oil is an oil of lubricating viscosity having a kinematic viscosity of 9.3 to about 16.3 cSt at a temperature of 100° C. and the second lubricating oil is an oil of lubricating viscosity having a kinematic viscosity about 2 to less than or equal to 9.3 cSt at a temperature of 100° C.  
     
     
         27 . The lubricating oil composition of  claim 25  wherein the fatty acid ester is an about C 6  to about C 24  fatty acid ester.  
     
     
         28 . The lubricating oil composition of  claim 25  wherein the fatty acid ester is a glycerol fatty acid ester.  
     
     
         29 . The lubricating oil composition of  claim 28  wherein the glycerol fatty acid ester is selected from the group consisting of palm, olive, cotton seed, castor, peanut, tallow, lard, whale, sunflower, soybean, coconut, palm kernel oils and combinations thereof  
     
     
         30 . The lubricating oil composition of  claim 25  wherein the alkanolamine possesses the general formula  
       RN(R′OH) 2-a H a    
       wherein R is hydrogen or an aminoalkyl group with the alkyl having from one to about six carbon atoms, R′ is a hydrocarbyl having from about two to about six carbon atoms and “a” is 0 or 1.  
     
     
         31 . The lubricating oil composition of  claim 30  wherein the alkanolamine is selected from the group consisting of monoethanolamine, diethanolamine, propanolamine, isopropanolamine, dipropanolamine, di-isopropanolamine, butanolamines, aminoethylaminoethanol and combinations thereof.  
     
     
         32 . The lubricating oil composition of  claim 25  wherein the friction modifier is the reaction product of a glycerol fatty acid ester and an alkanolamine.  
     
     
         33 . The lubricating oil composition of  claim 26  wherein the friction modifier is the reaction product of a glycerol fatty acid ester and an alkanolamine.  
     
     
         34 . The lubricating oil composition of  claim 25  wherein the friction modifier is the reaction product of a fatty acid ester selected from the group consisting of palm, olive, cotton seed, castor, peanut, tallow, lard, whale, sunflower, soybean, coconut, palm kernel oils and combinations thereof and an alkanolamine selected from the group consisting of monoethanolamine, diethanolamine, propanolamine, isopropanolamine, dipropanolamine, di-isopropanolamine, butanolamines, aminoethylaminoethanol and combinations thereof.  
     
     
         35 . The lubricating oil composition of  claim 25  wherein component (a) is an oil of lubricating viscosity having a kinematic viscosity of about 2 to less than 10.0 cSt at 100° C.  
     
     
         36 . The lubricating oil composition of  claim 25  wherein component (a) is an oil of lubricating viscosity having a kinematic viscosity of about 3.8 to less than or equal to 9.3 cSt at 100° C.  
     
     
         37 . The lubricating oil composition of  claim 25  wherein the amount of the ashless friction modifier present in the lubricating oil composition is 1 to about 4.5 weight percent, based on the total weight of the lubricating oil composition.  
     
     
         38 . The lubricating oil composition of  claim 35  wherein the amount of the ashless friction modifier present in the lubricating oil composition is 1 to about 4.5 weight percent, based on the total weight of the lubricating oil composition.  
     
     
         39 . The lubricating oil composition of  claim 25  wherein the first lubricating oil of component (a) is selected from the group consisting of a SAE 10W multigrade oil, a SAE 15W multigrade oil and mixtures thereof and the second lubricating oil of component (a) is selected from the group consisting of a SAE 0W multigrade oil, a SAE 5W multigrade oil and mixtures thereof.  
     
     
         40 . The lubricating oil composition of  claim 38  wherein the first lubricating oil of component (a) is a SAE 10W-30 multigrade oil and the second lubricating oil of component (a) is a SAE 5W-20 multigrade oil.  
     
     
         41 . A lubricating oil composition comprising (a) an oil of lubricating viscosity and (b) 1 to about 4.5 weight percent, based on the total weight of the lubricating oil composition, of an ashless friction modifier comprising a reaction product of a C 4  to about C 75  fatty acid ester and an alkanolamine.  
     
     
         42 . The lubricating oil composition of  claim 41  wherein the oil of component (a) comprises about 55 to about 85 weight percent of a first lubricating oil, and about 15 to about 45 weight percent of a second lubricating oil wherein the kinematic viscosity of the second lubricating oil is lower than the kinematic viscosity of the first lubricating oil at 100° C.  
     
     
         43 . The lubricating oil composition of  claim 41  wherein the friction modifier is the reaction product of a glycerol fatty acid ester and an alkanolamine.  
     
     
         44 . The lubricating oil composition of  claim 43  wherein the glycerol fatty acid ester is selected from the group consisting of palm, olive, cotton seed, castor, peanut, tallow, lard, whale, sunflower, soybean, coconut, palm kernel oils and combinations thereof.  
     
     
         45 . The lubricating oil composition of  claim 41  wherein the alkanolamine possesses the general formula  
       RN(R′OH) 2-a H a    
       wherein R is hydrogen or an aminoalkyl group with the alkyl having from one to about six carbon atoms, R′ is a hydrocarbyl having from about two to about six carbon atoms and “a” is 0 or 1.  
     
     
         46 . The lubricating oil composition of  claim 41  wherein the friction modifier is the reaction product of a fatty acid ester selected from the group consisting of palm, olive, cotton seed, castor, peanut, tallow, lard, whale, sunflower, soybean, coconut, palm kernel oils and combinations thereof and an alkanolamine selected from the group consisting of monoethanolamine, diethanolamine, propanolamine, isopropanolamine, dipropanolamine, di-isopropanolamine, butanolamines, aminoethylaminoethanol and combinations thereof.  
     
     
         47 . The lubricating oil composition of  claim 41  wherein component (a) comprises a first lubricating oil selected from the group consisting of a SAE 10W multigrade oil, a SAE 15W multigrade oil and mixtures thereof and a second lubricating oil selected from the group consisting of a SAE 0W multigrade oil, a SAE 5W multigrade oil and mixtures thereof.  
     
     
         48 . A method of improving the fuel economy of an internal combustion engine which comprises operating the engine with the lubricating oil composition of  claim 25 .  
     
     
         49 . A method of improving the fuel economy of an internal combustion engine which comprises operating the engine with the lubricating oil composition of  claim 35 .  
     
     
         50 . A method of improving the fuel economy of an internal combustion engine which comprises operating the engine with the lubricating oil composition of  claim 41.