Gear Oil Compositions, Methods of Making and Using Thereof

Abstract

A gear oil composition is provided. The composition comprises a synergistic amount of an isomerized base oil having consecutive numbers of carbon atoms and less than 10 wt % naphthenic carbon by n-d-M for the gear oil composition to have a traction coefficient at 15 mm 2 /s. of less than 0.030 and a pressure viscosity coefficient of at least 15.0 at 80° C. In one embodiment, the sufficient amount of isomerized base oil ranges from 20 to 80 wt. % based on the total weight of the gear oil composition.

1 . A gear oil composition, comprising:
 a) a base oil comprising a mixture of at least an isomerized base oil having consecutive numbers of carbon atoms and less than 10 wt % naphthenic carbon by n-d-M and a mineral oil having a kinematic viscosity of 3 to 120 mm2/s at 100° C. and a viscosity index of at least 60;   b) 0.001 to 30 wt % at least an additive selected from traction reducers, dispersants, viscosity modifiers, pour point depressants, antifoaming agents, antioxidants, rust inhibitors, metal passivators, extreme pressure agents, friction modifiers, and mixtures thereof;   wherein the isomerized base oil is present in a synergistic amount for the gear oil composition to have a traction coefficient at 15 mm2/s. of less than 0.030 at a slide to roll ratio of 40 percent and a pressure viscosity coefficient of at least 15.0 GPa-1 at 80° C., 20 Newton load, and 1.1 m/s rolling speed.   
     
     
         2 . The composition of  claim 1 , wherein the isomerized base oil has a viscosity index greater than an amount defined by: 28×Ln(Kinematic viscosity at 100° C.)+95. 
     
     
         3 . The composition of  claim 1 , wherein the isomerized base oil has a Kinematic Viscosity at 100° C. of >1.808 mm 2 /s and a Noack volatility less than an amount calculated by: 1.286+20 (kv100) −1.5 +551.8 e −kvm100 , where kv100 is the kinematic viscosity at 100° C. 
     
     
         4 . A method for improving the traction properties of a gear oil composition, the method comprises adding a synergistic amount of at least an isomerized base oil to a base oil matrix comprising at least a mineral oil having a kinematic viscosity of 3 to 120 mm 2 /s at 100° C. and a viscosity index of at least 60, for the gear oil composition to have a fraction coefficient at 15 mm 2 /s. of less than 0.030, a pressure viscosity coefficient of greater than 15.0 at 80° C., and a film thickness of greater than 175 nm at 80° C., wherein the isomerized base oil has consecutive numbers of carbon atoms and less than 10 wt % naphthenic carbon by n-d-M. 
     
     
         5 . A method for improving the traction properties of a gear oil, the method comprises preparing a base oil comprising a synergistic amount of isomerized base oil for the gear oil to have a traction coefficient at 15 mm 2 /s. of less than 0.030, a pressure viscosity coefficient of greater than 15.0 at 80° C., and a film thickness of greater than 175 nm at 80° C., wherein the isomerized base oil has consecutive numbers of carbon atoms and less than 10 wt % naphthenic carbon by n-d-M.