Additive to grease and grease composition

Abstract

Provided is an additive to grease comprising a salt including a silicon-containing phosphoric acid ester anion represented by the following formula (1).In the formula, R1 to R3 are independently alkyl groups having 1-4 carbon atoms. R4 is an alkyl group having 1-8 carbon atoms. n is an integer of 1-8.

1 . A grease additive comprising a salt which includes a silicon-containing phosphate ester anion of formula (1) below 
       
         
           
           
               
               
           
         
       
       wherein R 1  to R 3  are each independently an alkyl group of 1 to 4 carbon atoms, R 4  is an alkyl group of 1 to 8 carbon atoms, and n is an integer from 1 to 8. 
     
     
         2 . The grease additive of  claim 1 , wherein R 1  to R 3  are identical groups. 
     
     
         3 . The grease additive of  claim 2 , wherein R 1  to R 3  are all methyl groups. 
     
     
         4 . The grease additive of  claim 1 , wherein R 4  is an alkyl group of 1 to 4 carbon atoms. 
     
     
         5 . The grease additive of  claim 1 , wherein n is an integer from 2 to 4. 
     
     
         6 . The grease additive of  claim 5 , wherein n is 3. 
     
     
         7 . The grease additive of  claim 1 , wherein the salt includes an organic cation as the cation. 
     
     
         8 . The grease additive of  claim 1 , wherein the salt includes a phosphorus atom-containing cation as the cation. 
     
     
         9 . A grease composition comprising a base oil, a thickener and the grease additive of  claim 1 . 
     
     
         10 . The grease composition of  claim 9 , wherein the thickener is a fluoropolymer.