Composite material, and prepreg using same

Abstract

A composite material includes: a carbon fiber bundle in which a plurality of continuous carbon fibers is arranged; carbon nanotubes which adhere to respective surfaces of the carbon fibers; and a sizing agent which covers at least a part of each of the surfaces to which the carbon nanotubes adhere. When the composite material disposed such that a longitudinal direction is vertically oriented is pierced with an inspection needle having a diameter of 0.55 mm across the longitudinal direction, and the composite material and the inspection needle are relatively moved in the longitudinal direction by 40 mm at a speed of 300 mm/min, a maximum value of a load acting between the composite material and the inspection needle is smaller than 0.5 N.

1 . A composite material comprising:
 a carbon fiber bundle in which a plurality of continuous carbon fibers are arranged;   carbon nanotubes which adhere to respective surfaces of the carbon fibers; and   a sizing agent which covers at least a part of each of the surfaces to which the carbon nanotubes adhere, wherein   when the composite material disposed such that a longitudinal direction is vertically oriented is pierced with an inspection needle having a diameter of 0.55 mm across the longitudinal direction, and the composite material and the inspection needle are relatively moved in the longitudinal direction by 40 mm at a speed of 300 mm/min, a maximum value of a load acting between the composite material and the inspection needle is smaller than 0.5 N.   
     
     
         2 . The composite material according to  claim 1 , wherein
 the composite material has a shape of a strip in which 3 to 30 fibers of the carbon fibers are piled in a thickness direction.   
     
     
         3 . The composite material according to  claim 1 , wherein
 an average value of the load acting between the composite material and the inspection needle is smaller than 0.4 N.   
     
     
         4 . A prepreg comprising the composite material according to  claim 1 , and a matrix resin impregnated in the composite material.