Carbon fiber composite material and method of producing the same, formed product of carbon fiber composite and method of producing the same, carbon fiber-metal composite material and method of producing the same, and formed product of carbon fiber-metal composite and method of producing the same

Abstract

A method of producing a carbon fiber composite material including: mixing an elastomer which includes an unsaturated bond or a group having affinity to carbon nanofibers with metal particles; and dispersing the carbon nanofibers into the elastomer including the metal particles by a shear force.

What is claimed is: 
     
         1 . A carbon fiber composite material comprising:
 an elastomer; and   metal particles and carbon nanofibers uniformly dispersed in the elastomer,   wherein the elastomer includes an unsaturated bond or a group having affinity to the carbon nanofibers,   the elastomer in the composite material is in a uncrosslinked form and the composite material has a first spin-spin relaxation time (T2n) of 100 to 3,000 μsec, a second spin-spin relaxation time (T2nn) of 1,000 to 10,000 μsec or without the second spin-spin relaxation time, and a fraction (fin) of components having the second spin-spin relaxation time of less than 0.2, as measured at 150° C. by Hahn-echo method using a pulsed NMR technique with  1 H as an observing nucleus,   the metal particles have an average particle diameter of 500 μm or less, and   the metal particles are not ferromagnetic.   
     
     
         2 . The carbon fiber composite material as defined in  claim 1 , wherein the amount of the metal particles is 10 to 3,000 parts by weight for 100 parts by weight of the elastomer. 
     
     
         3 . The carbon fiber composite material as defined in  claim 1 , wherein the metal particles have an average particle diameter greater than an average diameter of the carbon nanofibers. 
     
     
         4 . The carbon fiber composite material as defined in  claim 1 , wherein the metal particles are aluminum particles or aluminum alloy particles. 
     
     
         5 . The carbon fiber composite material as defined in  claim 1 , wherein at least one of a main chain, a side chain and a terminal chain of the elastomer includes at least one of a double bond, a triple bond, α-hydrogen, a carbonyl group, a carboxyl group, a hydroxyl group, an amino group, a nitrile group, a ketone group, an amide group, an epoxy group, an ester group, a vinyl group, a halogen group, a urethane group, a biuret group, an allophanate group and a urea group. 
     
     
         6 . The carbon fiber composite material as defined in  claim 1 , wherein a network component of the elastomer in an uncrosslinked form has a spin-spin relaxation time (T2n) measured at 30° C. by a Hahn-echo method using pulsed nuclear magnetic resonance (NMR) technique of 100 to 3,000 μsec. 
     
     
         7 . The carbon fiber composite material as defined in  claim 1 , wherein a network component of the elastomer in a crosslinked form has a spin-spin relaxation time (T2n) measured at 30° C. by a Hahn-echo method using pulsed nuclear magnetic resonance (NMR) technique of 100 to 2,000 μsec. 
     
     
         8 . The carbon fiber composite material as defined in  claim 1 , wherein the carbon nanofibers have an average diameter of 0.5 to 500 nm. 
     
     
         9 . A formed product of carbon fiber composite obtained by forming the carbon fiber composite material as defined in  claim 1  into a predetermined shape. 
     
     
         10 . A formed product of carbon fiber composite obtained by crosslinking the carbon fiber composite material as defined in  claim 1 . 
     
     
         11 . A formed product of carbon fiber composite obtained by crosslinking the carbon fiber composite material as defined in  claim 1  and forming the carbon fiber composite material into a predetermined shape. 
     
     
         12 . The formed product of carbon fiber composite as defined in  claim 10 , having a spin-lattice relaxation time (T1) measured at 150° C. by a Hahn-echo method using pulsed nuclear magnetic resonance (NMR) technique per 1 vol % of the carbon nanofibers, the spin-lattice relaxation time (T1) for the formed product being at least one μsec shorter than the spin-lattice relaxation time (T1) of the elastomer. 
     
     
         13 . A carbon fiber-metal composite material obtained by mixing the carbon fiber composite material as defined in  claim 1  into a molten metal and casting the mixture. 
     
     
         14 . A carbon fiber-metal composite material obtained by mixing the formed product of carbon fiber composite as defined in  claim 9  into a molten metal and casting the mixture. 
     
     
         15 . A formed product of carbon fiber-metal composite obtained by:
 permeating a molten metal into the formed product of carbon fiber composite as defined in  claim 9  to replace the elastomer with the metal.   
     
     
         16 . The carbon fiber-metal composite material as defined in  claim 13 , wherein the molten metal is the same metal as the metal particles. 
     
     
         17 . The carbon fiber-metal composite material as defined in  claim 14 , wherein the molten metal is the same metal as the metal particles. 
     
     
         18 . A carbon fiber-metal composite material obtained by powder-forming the carbon fiber composite material as defined in  claim 1 . 
     
     
         19 . A carbon fiber-metal composite material obtained by powder-forming the formed product of carbon fiber composite as defined in  claim 9 .