Corrosion-resistant greases and wet lubricants

Abstract

A corrosion-resistant wet film lubricant composition includes a lubricating pigment, an oil, and a thickener. The lubricating pigment comprises graphene platelets and is dispersed in the oil, and the thickener thickens the wet film lubricant. The graphene platelets are oxidized and functionalized with a silane. In another example, a method of producing a corrosion-resistant lubricant includes oxidizing exfoliated graphene to produce oxidized graphene platelets, functionalizing the oxidized graphene platelets with a silane to produce functionalized graphene platelets, and dispersing the functionalized graphene platelets in a lubricant composition, wherein the lubricant composition comprises an oil and a thickener.

1 . A corrosion-resistant wet film lubricant composition comprising:
 a lubricating pigment comprising graphene platelets, wherein the graphene platelets are partially oxidized and functionalized with a silane;   an oil, wherein the lubricating pigment is dispersed in the oil; and   a thickener for thickening the wet film lubricant; and   wherein:
 the silane is selected to increase the propensity of the oxidized and functionalized graphene platelets to localize adjacent to a surface of an article, the article comprising a metal material; 
 the silane is selected to reduce galvanic corrosion of the article; 
 up to 15 wt % of oxygen of the oxidized graphene platelets are functionalized; and 
 the silane is represented by the following formula: 
   
       
         
           
           
               
               
           
         
         wherein:
 R 1  is selected from a group consisting of ethers and alcohols;
 R 2  is selected from a group consisting of alcohols, ethers, alkanes, and hydrogen; 
 R 3  is selected from a group consisting of alcohols, ethers, alkanes, and hydrogen; 
 X includes one or more of an alkane, a haloalkane, a perhaloalkane, an ester, an ether, an amide, an amine, and an epoxy; and 
 at least one of R 1 , R 2 , and R 3  is covalently bonded to the oxidized graphene platelets. 
 
 
       
     
     
         2 . (canceled) 
     
     
         3 . The corrosion-resistant wet film lubricant composition of  claim 1 , wherein the oxidized and functionalized graphene platelets have a concentration of 0.1 wt % to 5 wt % in the lubricant composition. 
     
     
         4 . The corrosion-resistant wet film lubricant composition of  claim 1 , wherein the silane forms at least one silyl ether linkage with the oxidized graphene platelets. 
     
     
         5 . The corrosion-resistant wet film lubricant composition of  claim 1 , wherein the silane comprises an alkoxysilane. 
     
     
         6 . The corrosion-resistant wet film lubricant composition of  claim 1 , where in the silane is selected from a group consisting of a monoalkoxysilane, a dialkoxysilane, and a trialkoxysilane. 
     
     
         7 - 8 . (canceled) 
     
     
         9 . The corrosion-resistant wet film lubricant composition of  claim 1 , wherein the wet film lubricant composition does not include chromate. 
     
     
         10 . The corrosion resistant wet film lubricant composition of  claim 1 , further comprising an additional corrosion inhibitor. 
     
     
         11 . The corrosion-resistant wet film lubricant composition of  claim 1 , wherein the graphene platelets have average diameters between 1 micrometer and 25 micrometers. 
     
     
         12 . The corrosion-resistant wet film lubricant composition of  claim 1 , wherein:
 the oxidized and functionalized graphene platelets have a concentration of less than 5 wt % in the lubricant composition;   the silane is selected to improve lubricity of the wet film lubricant composition;   the wet film lubricant composition does not include chromate; and   the graphene platelets have average diameters between 1 micrometer and 25 micrometers.   
     
     
         13 . A lubricated article comprising:
 a surface;   a coating of the corrosion-resistant wet film lubricant composition of  claim 1  on the surface.   
     
     
         14 . A method of producing a corrosion-resistant lubricant, the method comprising:
 oxidizing exfoliated graphene to produce oxidized graphene platelets;   functionalizing the oxidized graphene platelets with a silane to produce functionalized graphene platelets; and   dispersing the functionalized platelets in a lubricant composition, wherein the lubricant composition comprises an oil and a thickener;   wherein:
 the silane is selected to increase the propensity of the oxidized and functionalized graphene platelets to localize adjacent to a surface of an article, the article comprising a metal material; 
 the silane is selected to reduce galvanic corrosion of the article; 
 up to 15 wt % of oxygen of the oxidized graphene platelets are functionalized; and 
 the silane is represented by the following formula: 
   
       
         
           
           
               
               
           
         
         wherein:
 R 1  is selected from a group consisting of ethers and alcohols;
 R 2  is selected from a group consisting of alcohols, ethers, alkanes, and hydrogen; 
 R 3  is selected from a group consisting of alcohols, ethers, alkanes, and hydrogen; 
 X includes one or more of an alkane, a haloalkane, a perhaloalkane, an ester, an ether, an amide, an amine, and an epoxy; and 
 at least one of R 1 , R 2 , and R 3  is covalently bonded to the oxidized graphene platelets. 
 
 
       
     
     
         15 . (canceled) 
     
     
         16 . The method of  claim 14 , wherein dispersing the functionalized platelets in the lubricant composition comprises adding the functionalized graphene platelets at a concentration of 0.1 wt % to 0.5 wt % in the lubricant composition. 
     
     
         17 . The method of  claim 14 , wherein the silane forms at least one silyl ether linkage with the graphene platelets. 
     
     
         18 . The method of  claim 14 , where in the silane is selected from a group consisting of a monoalkoxysilane, a dialkoxysilane, and a trialkoxysilane. 
     
     
         19 - 20 . (canceled)