Composite material production method and composite material

Abstract

There are provided a method for producing a composite material from which a high-strength prepreg having CNT-derived properties fully exerted is obtained, comprising a step of immersing a carbon fiber bundle including a plurality of continuous carbon fibers in a carbon-nanotubes-isolated dispersion containing a plurality of isolatedly-dispersed carbon nanotubes and applying ultrasonic vibrations at a frequency of more than 40 kHz and 180 kHz or less to form a structure comprising a plurality of carbon nanotubes on the surface of each of the plurality of carbon fibers, wherein the structures are directly attached to the surface of each of the plurality of carbon fibers and form together a network structure in which the carbon nanotubes are directly connected to one another, and such a composite material.

1 . A method for producing a composite material, comprising
 a step of immersing a carbon fiber bundle including a plurality of continuous carbon fibers in a carbon-nanotubes-isolated dispersion containing a plurality of isolatedly-dispersed carbon nanotubes and applying ultrasonic vibrations at a frequency of more than 40 kHz and 180 kHz or less to form a structure comprising a plurality of carbon nanotubes on a surface of each of the plurality of carbon fibers,   wherein the structure is directly attached to the surface of each of the plurality of carbon fibers and has a network structure in which the carbon nanotubes are directly connected to one another.   
     
     
         2 . The method for producing a composite material according to  claim 1 , wherein the carbon fiber bundle comprises 10,000 to 30,000 carbon fibers. 
     
     
         3 . The method for producing a composite material according to  claim 1 , wherein the frequency of the ultrasonic vibrations is 100 kHz or more. 
     
     
         4 . A composite material produced by the method according to  claim 1 .