Carbon fiber and composite material

Abstract

An object of the present invention is to provide a carbon fibrous structure having good dispersibility and small variations in electrical conductivity, etc., and being capable of improving physical properties such as electrical properties, mechanical properties and thermal properties by a small amount addition thereof without impairing properties of a matrix. The invention provides a carbon fibrous structure having a three-dimensional network shape and comprising carbon fibers having an average outside diameter of from 100 to 300 nm, wherein the carbon fibrous structure has a plurality of granular parts, and has at least partially a steric network structure of the carbon fibers in a state that a plurality of the carbon fibers sterically extend outwardly from the granular parts and that the extending carbon fibers are also bound with other granular parts, wherein the granular parts have a particle diameter larger than an outer diameter of the carbon fiber, and are formed in a growth process of growing a carbon material in the circumferential direction of catalyst particles used while growing the carbon material into a fibrous shape, by using at least two carbon compounds having different decomposition temperature as carbon sources, and wherein the carbon fibrous structure has a powder resistance of 0.02Ω·cm or less measured at a compression density of 0.8 g/cm3.

Dependencies are inferred from the claim text.