Lubricant formulations containing extreme pressure agents

Abstract

A method for improving the solubility of a sulfurized extreme pressure agent in a lubricant composition and improved lubricant compositions and uses therefor. The method includes pre-blending organic acid and amine components of a lubricant additive package for the lubricant composition to provide a premixture of organic acid and amine components. The premixture is combined with a sulfurized extreme pressure agent having a viscosity of less than about 5.5 centistokes at 100° C. to provide a lubricant additive package. By use of the foregoing process, a turbidity characteristic of the lubricant composition containing the additive package is lower than a turbidity characteristic of a lubricant composition that is made by combining the organic acid and amine components with the sulfurized extreme pressure agent in the absence of the premixture.

1 . A method for improving the solubility of a sulfurized extreme pressure agent in a lubricant composition comprising a substantially non-polar base oil component, the method comprising pre-blending organic acid and amine components of a lubricant additive package for the lubricant composition to provide a premixture of organic acid and amine components and combining the premixture with a sulfurized extreme pressure agent having a viscosity of less than about 5.5 centistokes at 100° C. to provide a lubricant additive package, whereby a turbidity characteristic of the lubricant composition containing the additive package is lower than a turbidity characteristic of a lubricant composition that is made by combining the organic acid and amine components with the sulfurized extreme pressure agent in the absence of the premixture.  
     
     
         2 . The method of  claim 1 , wherein the sulfurized extreme pressure agent comprises a sulfurized olefin.  
     
     
         3 . The method of  claim 2 , wherein the sulfurized olefin comprises sulfurized isobutylene.  
     
     
         4 . The method of  claim 1 , further comprising combining the lubricant additive package with the substantially non-polar base oil component.  
     
     
         5 . The method of  claim 4 , wherein the substantially non-polar base oil component comprises a polyolefin base oil.  
     
     
         6 . The method of  claim 1 , wherein the substantially non-polar base oil component comprises a polyolefin base oil.  
     
     
         7 . The method of  claim 1 , wherein the substantially non-polar base oil component comprises a base oil selected from the group consisting of a Group II base oil, a Group III base oil, and a Group IV base oil.  
     
     
         8 . A gear lubricant made by the method of  claim 1 .  
     
     
         9 . A vehicle having moving parts containing the gear lubricant of  claim 8  for lubricating the moving parts.  
     
     
         10 . In a process for making a lubricant containing an extreme pressure agent, the improvement comprising combining at least organic acid and amine components of an additive package for the lubricant to provide a mixture, and, subsequently, combining the mixture with a sulfurized extreme pressure agent and a base oil to provide the lubricant, wherein the sulfurized extreme pressure agent is made by a process that provides a viscosity of the extreme pressure agent in a range that enhances the solubility of the extreme pressure agent in the lubricant.  
     
     
         11 . The process of  claim 10 , wherein the sulfurized extreme pressure agent comprises a sulfurized olefin.  
     
     
         12 . The process of  claim 11 , wherein the sulfurized olefin comprises sulfurized isobutylene.  
     
     
         13 . The process of  claim 12 , wherein the sulfurized isobutylene has a viscosity at 100° C. of no higher than about 5.5 centistokes.  
     
     
         14 . The process of  claim 10 , wherein the base oil comprises a substantially non-polar base oil component.  
     
     
         15 . The process of  claim 14  wherein the substantially non-polar base oil component comprises a polyolefin base oil.  
     
     
         16 . A gear lubricant made by the process of  claim 10 .  
     
     
         17 . A vehicle having moving parts containing the gear lubricant of  claim 16  for lubricating the moving parts.  
     
     
         18 . A method for producing a non-hazy lubricant composition containing a sulfurized extreme pressure agent and a substantially non-polar base oil component, the method comprising the steps of: 
 reacting a sulfur monochloride/isobutylene adduct with aqueous sodium hydrosulfide under conditions sufficient to provide a sulfurized isobutylene having a viscosity at 100° C. no higher than about 5.5 centistokes;    pre-blending organic acid and amine components of the lubricant composition to provide an additive package pre-mix;    subsequently, combining the additive package pre-mix with from about 50 to about 95 percent by weight of the sulfurized isobutylene to provide the additive composition; and    treating a base oil with the additive composition to provide the non-hazy lubricant composition.    
     
     
         19 . The method of  claim 18 , wherein the substantially non-polar base oil component comprises a polyolefin base oil.  
     
     
         20 . A gear lubricant comprising a mineral oil component and an additive composition made by the method of  claim 18 .  
     
     
         21 . A vehicle having moving parts containing the gear lubricant of  claim 20  for lubricating the moving parts.  
     
     
         22 . A method for making a sulfurized extreme pressure agent having characteristics that assist in the formation of a low turbidity substantially non-polar base oil containing lubricant, the method comprising the steps of: 
 reacting sulfur monochloride and an olefin under conditions sufficient to provide a sulfur/olefin adduct;    mixing and reacting the sulfur/olefin adduct with an aqueous sulfur source over a period of time sufficient to provide a sulfurized extreme pressure agent in an organic phase having a viscosity of no higher than about 5.5 centistokes at 100° C.; and    separating an aqueous phase and the organic phase containing the sulfurized extreme pressure agent from one another.    
     
     
         23 . The method of  claim 22 , wherein the sulfurized extreme pressure agent comprises sulfurized isobutylene.  
     
     
         24 . The method of  claim 23 , wherein the sulfurized isobutylene has a viscosity ranging from about 4.0 to about 5.5 centistokes at 100° C.  
     
     
         25 . The method of  claim 23 , wherein the sulfurized isobutylene has a sulfur content ranging from about 40 to about 50 percent by weight.  
     
     
         26 . The method of  claim 22 , wherein the step of mixing and reacting the sulfur/olefin adduct with an aqueous sulfur source is conducted over a period of time ranging from about 10 to less than about 60 minutes.