Coating composition for use in sliding members

Abstract

A coating composition for use in sliding members contains a polyamideimide resin and a solid lubricant and is prepared by mixing these ingredients. The polyamideimide resin is a substance having a glass transition temperature of 270° C. or above or a substance having a tensile strength of 200 MPa or more at room temperature. The sliding film made of the coating composition for use in sliding members is provided with a satisfactory sliding property.

1 . A coating composition for use in sliding members, wherein the composition is obtained by mixing a polyamide-imide resin and a solid lubricant, wherein at least one of the following requirements is satisfied: 
 (I) the glass transition temperature of the polyamide-imide resin is no less than 270° C.,    (II) the tensile strength of the polyamide-imide resin at room temperature is no less than 200 MPa, and    (III) the polyamide-imide resin contains more imide groups than amide groups.    
     
     
         2 . The compressor according to  claim 1 , wherein at least the requirement (I) is satisfied.  
     
     
         3 . The compressor according to  claim 1 , wherein at least the requirement (II) is satisfied.  
     
     
         4 . The compressor according to  claim 1 , wherein at least the requirement (III) is satisfied.  
     
     
         5 . The compressor according to  claim 1 , wherein the glass transition temperature is no less than 290° C.  
     
     
         6 . The compressor according to  claim 1 , wherein the solid lubricant contains polytetrafluoroethylene.  
     
     
         7 . The compressor according to  claim 1 , wherein isocyanate component, which is a crude material of the polyamide-imide resin, contains 5% to 90% by mol of 3,3′-dimethylbiphenyl-4,4′-diisocyanate.  
     
     
         8 . The compressor according to  claim 1 , wherein the number average molecular weight of the polyamide-imide resin is no less than 20,000.  
     
     
         9 . A coating composition for use in sliding members, wherein the composition is obtained by mixing a polyamide-imide resin and a solid lubricant, wherein the glass transition temperature of the polyamide-imide resin is no less than 270° C., the tensile strength of the polyamide-imide resin at room temperature is no less than 200 MPa, and the polyamide-imide resin contains more imide groups than amide groups.