Gear Oil Compositions, Methods of Making and Using Thereof

Abstract

A gear oil composition is provided. The composition comprises an isomerized base oil having consecutive numbers of carbon atoms, less than 0.05 wt. % aromatics, a viscosity index between 150 and 170, Oxidator BN of 15 to 50 hours; and 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. In one embodiment, composition displays a pressure viscosity coefficient of greater than 9.5 GPa −1 at 140° C. and a Timken OK load per D2782 (E2006) of at least 50 lbs.

1 . A gear oil composition, comprising:
 a) at least an isomerized base oil having consecutive numbers of carbon atoms, less than 0.05 wt. % aromatics, a kinematic viscosity at 100° C. between 6.5 mm 2 /s and 15.5 mm 2 /s, a kinematic viscosity at 40° C. between 35 mm 2 /s and 110 mm 2 /s a viscosity index between 150 and 170, Oxidator BN of 15 to 50 hours; and   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.   
   
   
       2 . The gear oil composition of  claim 1 , wherein the amount of viscosity modifiers is less than 0.5 wt. %. 
   
   
       3 . The gear oil composition of  claim 1 , wherein the composition has a Timken OK load per D2782 (E2006) of at least 50 lbs. 
   
   
       4 . The gear oil composition of  claim 1 , where the composition has a weld point per ASTM D2783-03 of at least 200 kg. 
   
   
       5 . The gear oil composition of  claim 1 , wherein the composition has a weld point per ASTM D2783-03 of at least 250 kg. 
   
   
       6 . The gear oil composition of  claim 1 , where in the composition has a viscosity increase of less than 2% as measured according to U.S. Steel S-200 Oxidation Test (U.S. Steel specification 224). 
   
   
       7 . The gear oil composition of  claim 1 , wherein the composition consists essentially of an isomerized base oil having consecutive numbers of carbon atoms, less than 0.05 wt. % aromatics, a viscosity index between 150 and 170, Oxidator BN of 15 to 50 hours; and less than 2 wt. % of 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. 
   
   
       8 . The gear oil composition of  claim 7 , wherein the composition displays a pressure viscosity coefficient of greater than 9.5 GPa −1  at 140° C., 20 Newton load and 1.1 m/s rolling speed. 
   
   
       9 . The gear oil composition of  claim 8 , wherein the composition has a film thickness of greater than 75 nm at 140° C., 20 Newton load and 1.1 m/s rolling speed. 
   
   
       10 . The gear oil composition of  claim 9 , wherein the composition has a film thickness of greater than 115 nm at 110° C., 20 Newton load and 1.1 m/s rolling speed. 
   
   
       11 . The gear oil composition of  claim 10 , wherein the composition has a film thickness of greater than 180 nm at 80° C., 20 Newton load and 1.1 m/s rolling speed. 
   
   
       12 . The composition of  claim 1 , wherein isomerized base oil is a Fischer-Tropsch derived base oil made from a waxy feed, having an average molecular weight between 500 and 1100, and an average degree of branching in the molecules between 6.5 and 10 alkyl branches per 100 carbon atoms. 
   
   
       13 . The composition of  claim 1 , wherein the isomerized base oil has an auto-ignition temperature (AIT) greater than an amount defined by: 1.6×(Kinematic Viscosity at 40° C., in mm 2 /s)+300. 
   
   
       14 . The composition of  claim 1 , wherein the isomerized base oil has an auto-ignition temperature (AIT) greater than 329° C. and a traction coefficient of less than 0.023 when measured at a kinematic viscosity of 15 mm 2 /s and at a slide to roll ratio of 40%. 
   
   
       15 . The composition of  claim 1 , wherein the isomerized base oil has a total weight percent of molecules with cycloparaffinic functionality of greater than 10, and a ratio of weight percent molecules with monocycloparaffinic functionality to weight percent molecules with multicycloparaffinic functionality of greater than 15. 
   
   
       16 . The composition of  claim 1 , wherein the isomerized base oil is made from a process in which the highly paraffinic wax is hydroisomerized using a shape selective intermediate pore size molecular sieve comprising a noble metal hydrogenation component, and under conditions of about 600° F. to 750° F. and wherein the isomerized base oil has a Noack volatility of less than 50 weight %. 
   
   
       17 . The composition of  claim 1 , wherein the isomerized base oil comprises greater than 3 weight % molecules with cycloparaffinic functionality and less than 0.30 weight percent aromatics. 
   
   
       18 . The composition of  claim 1 , wherein the isomerized base oil has a Noack volatility less than an amount defined by: 160-40 (Kinematic Viscosity at 100° C.).