Lubricant

Abstract

A lubricant in the form of lubricating oil or grease, for use in contact with graphite or molybdenum disulfide or in contact with aluminum materials, which comprises a perfluoropolyether oil free from (CF 2 O) n groups as a repeat unit of polymer and having a kinetic viscosity at 40° C. of 50-1,500 mm 2 /sec., as a base oil, where F(CF 2 CF 2 CF 2 O) m C 2 F 5 or RfO[CF(CF 3 )CF 2 O] p (CF 2 CF 2 O) q Rf′ s used as the perfluoropolyether base oil. The lubricant undergoes no considerable deterioration of high-temperature characteristics (high-temperature durability), even if used in various uses as mentioned above, and also has distinguished low-temperature characteristics when the base oil has a kinetic viscosity of 50-250 mm 2 /sec.

1 . A lubricant for use in contact with graphite or molybdenum disulfide or in contact with aluminum materials, which comprises a perfluoropolyether oil free from (CF 2 O) n  groups as a repeat unit of polymer and having a kinetic viscosity at 40° C. of 50-1,500 mm 2 /sec, as a base oil. 
     
     
         2 . A lubricant according to  claim 1 , wherein the perfluoropolyether base oil has a kinetic viscosity at 40° C. of 50-250 mm 2 /sec. 
     
     
         3 . A lubricant according to  claim 1 , wherein the perfluoropolyether base oil is at least one of perfluoropolyether oil (A) represented by the following general formula (A):
   F(CF 2 CF 2 CF 2 O) m C 2 F 5      
       (where m is an integer of 2-100), and perfluoropolyether oil (B) represented by the following general formula:
   RfO[CF(CF 3 )CF 2 O] p CF 2 CF 2 O) q Rf′ 
 
       (where Rf and Rf′ are same or different perfluoroalkyl groups having 1-5 carbon atoms, p+q=2-200, q/p=0-2, and q can be zero, and CF(CF 3 )CF 2 O groups and CF 2 CF 2 O groups are in random combination in the main chain). 
     
     
         4 . A lubricant according to  claim 2 , wherein the perfluoropolyether base oil is at least one of perfluoropolyether oil (A), represented by the following general formula:
   F(CF 2 CF 2 CF 2 O) m C 2 F 5      
       (where m is an integer of 2-100), and perfluoropolyether oil (B) represented by the following general formula (B):
   RfO[CF(CF 3 )CF 2 O] p (CF 2 CF 2 O) q Rf′ 
 
       (where Rf and Rf′ are same or different perfluoroalkyl groups having 1-5 carbon atoms, p+q=2-200, q/p=0-2, and q can be zero, and CF(CF 3 )CF 2 O groups and CF 2 CF 2 O groups are in random combination in the main chain). 
     
     
         5 . A lubricant according to  claim 1 , wherein the lubricant is a lubricating oil. 
     
     
         6 . A lubricant according to  claim 2 , wherein the lubricant is a lubricating oil. 
     
     
         7 . A lubricant according to  claim 1 , wherein a thickener is further contained, and the lubricant is used as a grease. 
     
     
         8 . A lubricant according to  claim 7 , wherein the thickener is fluororesin powder. 
     
     
         9 . A lubricant according to  claim 2 , wherein a thickener is further contained, and the lubricant is used as a grease. 
     
     
         10 . A lubricant according to  claim 9 , wherein the thickener is fluororesin powder. 
     
     
         11 . A lubricant according to  claim 1 , for use as impregnated in a sintered, oil-impregnated bearing containing graphite or molybdenum disulfide as a sintering component. 
     
     
         12 . A lubricant according to  claim 2 , for use as impregnated in a sintered, oil-impregnated bearing containing graphite or molybdenum disulfide as a sintering component. 
     
     
         13 . A lubricant according to  claim 1 , for use in contact with metallic parts containing graphite or molybdenum disulfide. 
     
     
         14 . A lubricant according to  claim 2 , for use in contact with metallic parts containing graphite or molybdenum disulfide. 
     
     
         15 . A lubricant according to  claim 1 , for use in atmospheres where graphite or molybdenum disulfide prevails as scattered particles or contaminants. 
     
     
         16 . A lubricant according to  claim 2 , for use in atmospheres where graphite or molybdenum disulfide prevails as scattered particles or contaminants. 
     
     
         17 . A lubricant according to  claim 1 , for use in contact with aluminum materials as a sliding member. 
     
     
         18 . A lubricant according to  claim 2 , for use in contact with aluminum materials as a sliding member.