Lubricant Compositions Comprising Boroxines and Sterically Hindered Amines To Improve Fluoropolymer Seal Compatibility

Abstract

A lubricant composition including a boroxine compound is disclosed. A lubricant composition and additive package including a boroxine compound and a sterically hindered amine compound are also disclosed. A method of lubricating a system comprising a fluoropolymer seal with the lubricant composition is also disclosed. The boroxine compound of the lubricant composition acts to improve compatibility of the lubricant composition with a fluoropolymer seal.

What is claimed: 
     
         1 . A lubricant composition having improved fluoropolymer compatibility, said lubricant composition comprising:
 a base oil;   a boroxine compound having general formula (I):   
       
         
           
           
               
               
           
         
         
           wherein each R 1  is independently an alkyl group having from 1 to 7 carbon atoms; and 
         
         a sterically hindered amine compound included in an amount ranging from 0.5 to 5 wt. % based on a total weight of said lubricant composition. 
       
     
     
         2 . The lubricant composition of  claim 1  wherein each R 1  is independently an alkyl group having from 1 to 5 carbon atoms. 
     
     
         3 . The lubricant composition of  claim 1  wherein said boroxine compound is included in an amount ranging from 0.1 to 5 wt. % based on said total weight of said lubricant composition. 
     
     
         4 . The lubricant composition of  claim 1  wherein at least 50 wt. % of said boroxine compound remains unreacted in said lubricant composition based on a total weight of said boroxine compound utilized to form said lubricant composition prior to any reaction in said lubricant composition. 
     
     
         5 . The lubricant composition of  claim 1  wherein said sterically hindered amine compound comprises at least one piperidine ring and at least one ester group. 
     
     
         7 . The lubricant composition of  claim 1  wherein said sterically hindered amine compound is (2,2,6,6-tetramethyl-4-piperidyl)dodecanoate. 
     
     
         8 . The lubricant composition of  claim 1  wherein said sterically hindered amine compound has a total base number of at least 70 mg KOH/g when tested according to ASTM D4739. 
     
     
         9 . The lubricant composition of  claim 1  wherein said base oil has a viscosity ranging from 1 to 20 cSt when tested at 100° C. according to ASTM D445 and is selected from the group of API group I oils, API group II oils, API group III oils, API group IV oils, API group V oils, and combinations thereof. 
     
     
         10 . The lubricant composition of  claim 1  further comprising a dispersant. 
     
     
         11 . The lubricant composition of  claim 10  wherein said dispersant is included in said lubricant composition in an amount ranging from 0.01 to 15 wt. % based on said total weight of said lubricant composition. 
     
     
         12 . The lubricant composition of  claim 11  wherein said dispersant is a polyalkene amine derived from a polyisobutene. 
     
     
         13 . The lubricant composition of  claim 1  further comprising a dihydrocarbyldithiophosphate salt. 
     
     
         14 . The lubricant composition of  claim 13  wherein said dihydrocarbyldithiophosphate salt comprises a zinc dihydrocarbyldithiophosphate salt. 
     
     
         15 . The lubricant composition of  claim 13  wherein said dihydrocarbyldithiophosphate salt is included in said lubricant composition in an amount ranging from 0.1 to 10 wt. % based on said total weight of said lubricant composition. 
     
     
         16 . The lubricant composition of  claim 1  wherein said lubricant composition has a fluoropolymer seal compatibility such that a fluoropolymer seal submerged in said lubricant composition exhibits a change in tensile strength of less than 45% when tested according to CEC L-39-T96. 
     
     
         17 . The lubricant composition of  claim 1  wherein said lubricant composition has a fluoropolymer seal compatibility such that a fluoropolymer seal submerged in said lubricant composition exhibits a change in elongation at rupture of less than 60% when tested according to CEC L-39-T96. 
     
     
         18 . A method of lubricating a system comprising a fluoropolymer seal, said method comprising:
 providing a lubricant composition comprising a base oil, a boroxine compound, and a sterically hindered amine compound included in an amount ranging from 0.5 to 5 wt. % based on the total weight of the lubricant composition; and   contacting the fluoropolymer seal with the lubricant composition,   wherein the boroxine compound has general formula (I):   
       
         
           
           
               
               
           
         
       
       and
 wherein each R 1  is independently an alkyl group having from 1 to 7 carbon atoms. 
 
     
     
         19 . A lubricant composition comprising:
 a base oil;   a boroxine compound having general formula (I):   
       
         
           
           
               
               
           
         
         
           wherein each R 1  is independently an alkyl group having from 1 to 7 carbon atoms; and 
         
         a sterically hindered amine compound having the general formula (II) or (III): 
       
       
         
           
           
               
               
           
         
         
           wherein each R 2  is independently a hydrogen atom or a hydrocarbyl group having from 1 to 17 carbon atoms, and wherein at least two groups designated by R 2  are an alkyl group; 
           wherein each R 3  is independently a hydrogen atom or a hydrocarbyl group having from 1 to 17 carbon atoms; 
           wherein each R 4  is independently a hydrogen atom or a hydrocarbyl group having from 1 to 17 carbon atoms, and wherein at least two groups designated by R 4  are an alkyl group; 
           wherein each R 5  is independently a hydrogen atom or a hydrocarbyl group having from 1 to 17 carbon atoms, and 
           wherein said hydrocarbyl groups designated by R 2 , R 3 , R 4 , and R 5  are each independently an alcohol group, an alkyl group, an amide group, an ether group or an ester group. 
         
       
     
     
         20 . The lubricant composition of  claim 19  wherein each R 1  has independently from 1 to 5 carbon atoms. 
     
     
         21 . The lubricant composition of  claim 19  wherein said boroxine compound is included in an amount ranging from 0.1 to 5 wt. % based on a total weight of said lubricant composition. 
     
     
         22 . The lubricant composition of  claim 19  wherein at least 50 wt. % of said boroxine compound remains unreacted in said lubricant composition based on a total weight of said boroxine compound utilized to form said lubricant composition prior to any reaction in said lubricant composition. 
     
     
         23 . The lubricant composition of  claim 19  wherein said sterically hindered amine compound has the general formula (IV): 
       
         
           
           
               
               
           
         
         wherein each R 2  and R 3  are as described above, and wherein at least three of R 2  are independently an alkyl group. 
       
     
     
         24 . The lubricant composition of  claim 19  wherein said sterically hindered amine has a total base number of at least 70 mg KOH/g when tested according to ASTM D4739. 
     
     
         25 . The lubricant composition of  claim 19  wherein said base oil has a viscosity ranging from 1 to 20 cSt when tested at 100° C. according to ASTM D445 and is selected from the group of API group I oils, API group II oils, API group III oils, API group IV oils, API group V oils, and combinations thereof. 
     
     
         26 . The lubricant composition of  claim 19  further comprising a dispersant. 
     
     
         27 . The lubricant composition of  claim 26  wherein said dispersant is included in said lubricant composition in an amount ranging from 0.01 to 15 wt. % based on a total weight of said lubricant composition. 
     
     
         28 . The lubricant composition of  claim 27  wherein said amine dispersant is a polyalkene amine derived from a polyisobutene. 
     
     
         29 . The lubricant composition of  claim 19  further comprising a dihydrocarbyldithiophosphate salt. 
     
     
         30 . The lubricant composition of  claim 29  wherein said dihydrocarbyldithiophosphate salt comprises a zinc dihydrocarbyldithiophosphate salt. 
     
     
         31 . The lubricant composition of  claim 29  wherein said dihydrocarbyldithiophosphate salt is included in said lubricant composition in an amount ranging from 0.1 to 10 wt. % based on a total weight of said lubricant composition. 
     
     
         32 . The lubricant composition of  claim 19  wherein said lubricant composition has a fluoropolymer seal compatibility such that a fluoropolymer seal submerged in said lubricant composition exhibits a change in tensile strength of less than 45% when tested according to CEC L-39-T96. 
     
     
         33 . The lubricant composition of  claim 19  wherein said lubricant composition has a fluoropolymer seal compatibility such that a fluoropolymer seal submerged in said lubricant composition exhibits a change in elongation at rupture of less than 60% when tested according to CEC L-39-T96. 
     
     
         34 . An additive package for a lubricant composition, said additive package comprising:
 a boroxine compound having general formula (I):   
       
         
           
           
               
               
           
         
         
           wherein each R 1  is independently an alkyl group having from 1 to 7 carbon atoms; and 
         
         a sterically hindered amine compound having the general formula (II) or (III): 
       
       
         
           
           
               
               
           
         
         
           wherein each R 2  is independently a hydrogen atom or a hydrocarbyl group having from 1 to 17 carbon atoms, and wherein at least two groups designated by R 2  are an alkyl group; 
           wherein each R 3  is independently a hydrogen atom or a hydrocarbyl group having from 1 to 17 carbon atoms; 
           wherein each R 4  is independently a hydrogen atom or a hydrocarbyl group having from 1 to 17 carbon atoms, and wherein at least two groups designated by R 4  are an alkyl group; 
           wherein each R 5  is independently a hydrogen atom or a hydrocarbyl group having from 1 to 17 carbon atoms, and 
           wherein said hydrocarbyl groups designated by R 2 , R 3 , R 4 , and R 5  are each independently an alcohol group, an alkyl group, an amide group, an ether group, or an ester group.