Lubricating Grease Composition

Abstract

A lubricating grease composition, which comprises a base oil consisting of a mixture of 100 parts by weight of at least one of a perfluoropolyether oil (A), represented by RfO[CF(CF 3 )CF 2 O] p (CF 2 CF 2 O) q Rf (where Rf is a perfluoroalkyl group having 1-5 carbon atoms, p+q=2-200, q/p=0-2, and q may be 0), and a perfluoropolyether oil (B), represented by F(CF 2 CF 2 CF 2 O) s C 2 F 5 (where s=2-100), and 0-100 parts by weight of at least one of a perfluoropolyether oil (C), represented by RfO(CF 2 CF 2 O) m (CF 2 O) n Rf (where m+n=3-200 and m:n=10-90:90-10), and a perfluoropolyether oil (D), represented by RfO[CF(CF 3 )CF 2 O] a (CF 2 CF 3 O) b (CF 2 O) c Rf (where a+b+c=3-200, b is 0 or an integer of 1 or more, and c is an integer of 1 or more), preferably further admixed with a thickening agent, can suppress corrosion of metallic materials by corrosive gases and also has a good heat resistance.

1 : A lubricating grease composition, which comprises a base oil consisting of a mixture of 100 parts by weight of at least one of a perfluoropolyether oil (A), represented by the following general formula:  
         RfO [CF(CF 3 )CF 2 O] p (CF 2 CF 2 O) q Rf 
       where Rf is a perfluoroalkyl group having 1-5 carbon atoms, p+q=2-200, q/p=0-2, q can be 0, and CF(CF 3 )CF 2 O group and CF 2 CF 2 O group are bonded at random in the main chain and a perfluoropolyether oil (B), represented by the following general formula:  
         F(CF 2 CF 2 CF 2 O) s C 2 F 5   
       where s=2-100, and 0-100 parts by weight of at least one of a perfluoropolyether oil (C), represented by the following general formula:  
         RfO(CF 2 CF 2 O) m (CF 2 O) n Rf 
       where Rf has the same meaning as defined above, m+n=3-200, m:n=10-90:90-10, and CF 2 CF 2 O group and CF 2 O group are bonded at random in the main chain and a perfluoropolyether oil (D), represented by the following general formula:  
         RfO [CF(CF 3 )CF 2 O] 3 (CF 2 CF 2 O) b (CF 2 O) c Rf 
       where Rf has the same meaning as defined above, a+b+c=3-200, b is 0 or an integer of 1 or more, c is an integer of 1 or more, and FC(CF 3 )CF 2 O group, CF 2 CF 2 O group, and CF 2 O group are bonded at random in the main chain.  
     
     
         2 : A lubricating grease composition according to  claim 1 , wherein viscosity of the perfluoropolyether oils (A), (B), (C), and (D) as the base oil are each 5-2,000 mm 2 /sec. in terms of dynamic viscosity at 40° C.  
     
     
         3 : A lubricating grease composition according to  claim 1 , wherein a thickening agent is further contained in a proportion of 0.1-50% by weight on the basis of the total of the composition.  
     
     
         4 : A lubricating grease composition according to  claim 1 , further comprising at least one of an antioxidant, an antirust agent, a corrosion inhibitor, an extreme agent, an oiliness agent, and a solid lubricant.  
     
     
         5 : A lubricating grease composition according to  claim 3 , further comprising at least one of an antioxidant, an antirust agent, a corrosion inhibitor, an extreme agent, an oiliness agent, and a solid lubricant.  
     
     
         6 : A metal surface that is protected by the lubricating grease composition according to  claim 1  against corrosive gases.  
     
     
         7 : A metal surface that is protected by the lubricating grease composition according to  claim 3  against corrosive gases.  
     
     
         8 : A metal surface that is protected by the lubricating grease composition according to  claim 6  against sulfide gases.  
     
     
         9 : A metal surface that is protected by the lubricating grease composition according to  claim 7  against sulfide gases.