Composite material
An composite material is disclosed, which includes carbon fibrous structures which are capable of being included in a relatively large amount in the composite material, and which are capable of improving the physical properties, such as electric, mechanical, or thermal properties. The carbon fibrous structure comprises (a) carbon fibrous structures each of which comprises a three dimensional network of carbon fibers, each of the carbon fibers having an outside diameter of 15-100 nm, wherein the carbon fibrous structure further comprises a granular part, at which the carbon fibers are bound in a state that the carbon fibers are extended outwardly therefrom, and wherein the granular part is produced in a growth process of the carbon fibers, and (b) an material other than the carbon fibrous structures, wherein the amount of carbon fibrous structures added is more than 30% and not more than 100% by weight of the total weight of the composite.
1. Composite material comprising (a) carbon fibrous structures each of which comprises a three dimensional network of carbon fibers, each of the carbon fibers having an outside diameter of 15-100 nm, wherein the carbon fibrous structure further comprises a granular part, at which the carbon fibers are bound in a state that the carbon fibers are extended outwardly therefrom, and wherein the granular part is produced in a growth process of the carbon fibers, and (b) an material other than the carbon fibrous structures (hereinafter, referred to as “other material”), wherein the amount of carbon fibrous structures added is more than 30% and not more than 100% by weight of the total weight of the composite.
2. The composite material according to claim 1 , wherein the carbon fibrous structures may have an area-based circle-equivalent mean diameter of 50-100 μm.
3. The composite material according to claim 1 , wherein said carbon fibrous structure has a bulk density of 0.0001-0.05 g/cm 3 .
4. The composite material according to claim 1 , wherein I D /I G of said carbon fibrous structure determined by Raman spectroscopy (measured using 514 nm of argon laser) is not more than 0.2.
5. The composite material according to claim 1 , wherein said carbon fibrous structure has a combustion initiation temperature in air of not less than 750° C.
6. The composite material according to claim 1 , wherein a particle diameter of the granular part is larger than outside diameters of the carbon fibers.
7. The composite material according to claim 1 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds which have different decomposition temperatures.
8. The composite material according to claim 1 , wherein the other material comprises an organic polymer.
9. The composite material according to claim 1 , wherein the other material comprises an inorganic material.
10. The composite material according to claim 1 , wherein the other material comprises a metal.
11. The composite material according to claim 1 , wherein the composite material further comprises at least one of filler selected from the group consisting of metallic fine particles, silica, calcium carbonate, magnesium carbonate, carbon black, glass fibers, and carbon fibers.