Carbon fiber composite material and method of producing the same

Abstract

A method of producing a carbon fiber composite material includes: a first mixing step of mixing an elastomer and carbon nanofibers at a first temperature; and a second mixing step of mixing a mixture obtained by the first mixing step at a second temperature, and the first temperature is 50 to 100° C. lower than the second temperature.

1 . A carbon fiber composite material obtained by a method comprising:
 a first mixing step of mixing an elastomer and carbon nanofibers at a first temperature;   a second mixing step of mixing a mixture obtained by the first mixing step at a second temperature; and   a third mixing step of mixing the carbon fiber composite material obtained by the second mixing step at a third temperature;   wherein:
 the first temperature is 50 to 100° C. lower than the second temperature; 
 the elastomer is ethylene propylene rubber (EPDM); 
 the third temperature is lower than the second temperature; and 
   the third mixing step comprises performing tight milling a plurality of times by using an open roll with a rotor interval of 0.5 mm or less.   
     
     
         2 . The carbon fiber composite material as defined in  claim 1 , wherein the elastomer has a molecular weight of 5,000 to 5,000,000. 
     
     
         3 . The carbon fiber composite material as defined in  claim 1 , wherein:
 the first temperature is 0 to 50° C.; and   the second temperature is 50 to 150° C.   
     
     
         4 . The carbon fiber composite material as defined in  claim 1 , wherein the carbon nanofibers have an average diameter of 0.5 to 500 nm. 
     
     
         5 . The carbon fiber composite material as defined in  claim 1 , wherein the first mixing step comprises mixing the elastomer and the carbon nanofibers together with carbon black.