Sliding composition and sliding member

Abstract

In prior art, the wear resistance and frictional properties of a sliding member are improved by adding bismuth, an alkaline earth metal salt or the like, but not lead, to a polytetrafluoroethylene used as a base resin, in view of the undesirable influences of lead on the environment. However, a further improved wear resistance at a high PV value has been desirable. In the present invention, a sliding member having excellent wear resistance and frictional properties even when used at a high PV value can be obtained by using a thermosetting resin as a base resin in a proportion of 50 to 80 vol % and adding thereto a PTFE with a molecular weight of 3,000,000 or more in a proportion of 10 to 40 vol % and bismuth and/or a bismuth alloy in a proportion of 1 to 20 vol %.

What is claimed as new and desired to be protected by Letters Patent of the United States is:  
     
         1 . A sliding composition comprising 50 to 80 vol % of a thermosetting resin, 10 to 40 vol % of a polytetrafluoroethylene having a molecular weight of 3,000,000 or more and 1 to 20 vol % of bismuth and/or a bismuth alloy.  
     
     
         2 . A sliding composition comprising 50 to 80 vol % of a thermosetting resin, 10 to 40 vol % of a polytetrafluoroethylene having a molecular weight of 3,000,000 or more and 1 to 20 vol % of an alkaline earth metal salt.  
     
     
         3 . A sliding composition comprising 50 to 80 vol % of a thermosetting resin, 10 to 40 vol % of a polytetrafluoroethylene having a molecular weight of 3,000,000 or more and 1 to 20 vol % in total of bismuth or a bismuth alloy, or both and an alkaline earth metal salt.  
     
     
         4 . A sliding composition according to  claim 1 , which further comprises 1 to 30 vol % of a solid lubricant.  
     
     
         5 . A sliding composition according to  claim 2 , which further comprises 1 to 30 vol % of a solid lubricant.  
     
     
         6 . A sliding composition according to  claim 3 , which further comprises 1 to 30 vol % of a solid lubricant.  
     
     
         7 . A sliding member obtained by coating a substrate with a sliding composition according to  claim 1 .  
     
     
         8 . A sliding member obtained by coating a substrate with a sliding composition according to  claim 2 .  
     
     
         9 . A sliding member obtained by coating a substrate with a sliding composition according to  claim 3 .  
     
     
         10 . A sliding member obtained by coating a substrate with a sliding composition according to  claim 4 .  
     
     
         11 . A sliding member obtained by coating a substrate with a sliding composition according to  claim 5 .  
     
     
         12 . A sliding member obtained by coating a substrate with a sliding composition according to  claim 6 .  
     
     
         13 . A sliding member obtained by coating a porous layer formed on a substrate with a sliding composition according to  claim 1  by impregnation.  
     
     
         14 . A sliding member obtained by coating a porous layer formed on a substrate with a sliding composition according to  claim 2  by impregnation.  
     
     
         15 . A sliding member obtained by coating a porous layer formed on a substrate with a sliding composition according to  claim 3  by impregnation.  
     
     
         16 . A sliding member obtained by coating a porous layer formed on a substrate with a sliding composition according to  claim 4  by impregnation.  
     
     
         17 . A sliding member obtained by coating a porous layer formed on a substrate with a sliding composition according to  claim 5  by impregnation.  
     
     
         18 . A sliding member obtained by coating a porous layer formed on a substrate with a sliding composition according to  claim 6  by impregnation.