High conductivity lubricating oils for electric and hybrid vehicles

Abstract

Provided is a lubricating oil for electric and hybrid vehicles. The lubricating oil has a composition including at least 80 wt % of a lubricating base oil, from 0.8 to 5 wt % of one or more metal detergents, from 0 to 5 wt % of one or more dispersants, from 0 to 1.5 wt % of zinc dialkyldithiophosphate antiwear agent, from 0 to 0.2 wt % of a molybdenum dialkyldithiocarbamate, from 0 to 2 wt % of a viscosity modifier based on active ingredient, and from 0.01 to 5 wt % of other lubricating oil additives. The lubricating oil has an electrical conductivity from 3,000 to 20,000 pS/m, and kinematic viscosity from 2 to 20 cSt at 100° C. This disclosure also relates to methods for producing the lubricating oil, methods for lubricating electric and hybrid vehicles, and methods for controlling electrical conductivity of a lubricating oil by using conductivity promoters and conductivity inhibitors.

1 . A lubricating oil for use in an electric or hybrid vehicles comprising:
 at least about 80 weight percent of a lubricating base oil, from about 0.8 to about 5 weight percent of one or more metal detergents, from about 0 to about 5 weight percent of one or more dispersants, from about 0 to about 1.5 weight percent of zinc dialkyldithiophosphate (ZDDP) antiwear agent, from about 0 to about 0.2 weight percent of a molybdenum dialkyldithiocarbamate (MoDTC), from about 0 to about 2 weight percent of a viscosity modifier based on active ingredient, and from about 0.01 to about 5 weight percent of other lubricating oil additives, and   wherein the lubricating oil has an electrical conductivity from about 3,000 pS/m to about 20,000 pS/m, and kinematic viscosity from about 2 cSt to about 20 cSt at 100° C.   
     
     
         2 . The lubricating oil of  claim 1  wherein the lubricating base oil comprises a Group I base stock, a Group II base stock, a Group III base stock, a Group IV base stock, a Group V base stock, or mixtures thereof. 
     
     
         3 . The lubricating oil of  claim 1  wherein the one or more dispersants are selected from the group consisting of borated dispersants, non-borated dispersants, and mixtures thereof. 
     
     
         4 . The lubricating oil of  claim 1  wherein the zinc dialkyldithiophosphate is a secondary zinc dialkyldithiophosphate. 
     
     
         5 . The lubricating oil of  claim 1  wherein the viscosity modifier is selected from the group consisting of a linear or star-shaped polymer, a polymer or copolymer of methacrylate, butadiene, an olefin, or a styrene, and mixtures thereof. 
     
     
         6 . The lubricating oil of  claim 1  wherein the electric or hybrid vehicle has an electric vehicle powertrain including one or more of an electric motor, an electric drive motor, a motor, a transmission, a front axle, a rear axle, a gear box, a differential, gears, bearings, a battery, a capacitor, a generator, an alternator, a converter, a kinetic energy accumulator, or a kinetic energy recovery system. 
     
     
         7 . The lubricating oil of  claim 1  wherein the one or more metal detergents are present in an amount of from about 0.8 to about 1.25, the one or more dispersants are present in an amount of from about 0.5 to about 5 weight percent, the zinc dialkyldithiophosphate (ZDDP) antiwear agent is present from about 0.6 to 1.5 weight percent, and the molybdenum dialkyldithiocarbamate (MoDTC) is present in an amount of about 0.15 weight percent; and
 wherein the lubricating oil has an electrical conductivity from about 3,000 pS/m to about 8,000 pS/m. 
 
     
     
         8 . A method for lubricating electric or hybrid vehicles comprising:
 providing to one or more components of the electric or hybrid vehicle powertrain a lubricating oil comprising at least about 80 weight percent of a lubricating base oil, from about 0.8 to about 5 weight percent of one or more metal detergents, from about 0 to about 5 weight percent of one or more dispersants, from about 0 to about 1.5 weight percent of zinc dialkyldithiophosphate (ZDDP) antiwear agent, from about 0 to about 0.2 weight percent of a molybdenum dialkyldithiocarbamate (MoDTC), from about 0 to about 2 weight percent of a viscosity modifier based on active ingredient, and from about 0.01 to about 5 weight percent of other lubricating oil additives, and   wherein the lubricating oil has an electrical conductivity from about 3,000 pS/m to about 20,000 pS/m, and kinematic viscosity from about 2 cSt to about 20 cSt at 100° C.   
     
     
         9 . The method of  claim 8  wherein the lubricating base oil comprises a Group I base stock, a Group II base stock, a Group III base stock, a Group IV base stock, a Group V base stock, or mixtures thereof. 
     
     
         10 . The method of  claim 8  wherein the one or more dispersants are selected from the group consisting of borated dispersants, non-borated dispersants, and mixtures thereof. 
     
     
         11 . The method of  claim 8  wherein the zinc dialkyldithiophosphate is a secondary zinc dialkyldithiophosphate. 
     
     
         12 . The method of  claim 8  wherein the viscosity modifier is selected from the group consisting of a linear or star-shaped polymer, a polymer or copolymer of methacrylate, butadiene, an olefin, or a styrene, and mixtures thereof. 
     
     
         13 . The method of  claim 8  wherein the one or more components of the electric or hybrid vehicle powertrain include one or more of an electric motor, an electric drive motor, a motor, a transmission, a front axle, a rear axle, a gear box, a differential, gears, bearings, a battery, a capacitor, a generator, an alternator, a converter, a kinetic energy accumulator, or a kinetic energy recovery system. 
     
     
         14 . The method of  claim 8  wherein the one or more metal detergents are present in an amount of from about 0.8 to about 1.25, the one or more dispersants are present in an amount of from about 0.5 to about 5 weight percent, the zinc dialkyldithiophosphate (ZDDP) antiwear agent is present from about 0.6 to 1.5 weight percent, and the molybdenum dialkyldithiocarbamate (MoDTC) is present in an amount of about 0.15 weight percent; and
 wherein the lubricating oil has an electrical conductivity from about 3,000 pS/m to about 8,000 pS/m. 
 
     
     
         15 . A method of producing a lubricating oil for use in electric or hybrid vehicles comprising:
 providing at least about 80 weight percent of a lubricating base oil, from about 0.8 to about 5 weight percent of one or more metal detergents, from about 0 to about 5 weight percent of one or more dispersants, from about 0 to about 1.5 weight percent of zinc dialkyldithiophosphate (ZDDP), from about 0 to about 0.2 weight percent of molybdenum dialkyldithiocarbamate (MoDTC), from about 0 to about 2 weight percent of an active viscosity modifier, and from about 0.01 to about 5 weight percent of other lubricating oil additives; and   blending the lubricating base oil, the one or more dispersants, the one or more metal detergents, the zinc dialkyldithiophosphate, the molybdenum dialkyldithiocarbamate, the active viscosity modifier and the one or more other lubricating oil additives to produce the lubricating oil, and   wherein the lubricating oil has electrical conductivity of from about 3,000 pS/m to about 20,000 pS/m, and kinematic viscosity of from about 2 cSt to about 20 cSt at 100° C.   
     
     
         16 . The method of  claim 15  wherein the lubricating base oil comprises a Group I, Group II, Group III, Group IV, Group V base oil, or mixtures thereof. 
     
     
         17 . The method of  claim 15  wherein the dispersant is selected from borated dispersants, non-borated dispersants, and mixtures thereof. 
     
     
         18 . The method of  claim 15  wherein the zinc dialkyldithiophosphate is a secondary zinc dialkyldithiophosphate. 
     
     
         19 . The method of  claim 15  wherein the viscosity modifier is selected from the group consisting of a linear or star-shaped polymer, a polymer or copolymer of methacrylate, butadiene, an olefin, or a styrene, and mixtures thereof. 
     
     
         20 . The method of  claim 15  wherein the electric or hybrid vehicle has an electric vehicle powertrain including one or more of an electric motor, an electric drive motor, a motor, a transmission, a front axle, a rear axle, a gear box, a differential, gears, bearings, a battery, a capacitor, a generator, an alternator, a converter, a kinetic energy accumulator, or a kinetic energy recovery system. 
     
     
         21 . The method of  claim 15  wherein the one or more metal detergents are present in an amount of from about 0.8 to about 1.25, the one or more dispersants are present in an amount of from about 0.5 to about 5 weight percent, the zinc dialkyldithiophosphate (ZDDP) antiwear agent is present from about 0.6 to 1.5 weight percent, and the molybdenum dialkyldithiocarbamate (MoDTC) is present in an amount of about 0.15 weight percent; and
 wherein the lubricating oil has an electrical conductivity from about 3,000 pS/m to about 8,000 pS/m.