Composite material

1. A composite material comprising a matrix and carbon fibrous structures,

wherein each of the carbon fibrous structures comprises a three dimensional network of carbon fibers each having an outside diameter of 15–100 nm, wherein the carbon fibrous structure further comprises a granular part with which carbon fibers are bound in a state such that the carbon fibers extend outwardly from the granular part, and wherein the granular part is produced in a growth process of the carbon fibers, and

wherein an amount of the carbon fibers added to the matrix is in a range of 0.1 to 30% by weight of a total weight of the composite material.

2. The composite material according to claim 1 , wherein the carbon fibrous structures have an area based circle-equivalent mean diameter of 50–100 μm.

3. The composite material according to claim 2 , wherein the carbon fibrous structures have a bulk density of 0.0001–0.05 g/cm 3 .

4. The composite material according to claim 3 , wherein the carbon fibrous structure have a bulk density of 0.001–0.02 g/cm 3 .

5. The composite material according to claim 4 , wherein I D /I G of the carbon fibrous structures determined by Raman spectroscopy is not more than 0.2, wherein I D is peak intensity at 1360 cm −1 and I G is peak at 1580 cm −1 .

6. The composite material according to claim 5 , wherein I D /I G of the carbon fibrous structures determined by Raman spectroscopy is not more than 0.1.

7. The composite material according to claim 6 , wherein the carbon fibrous structures have a combustion initiation temperature in air of not less than 750° C.

8. The composite material according to claim 7 , wherein a diameter of the granular part is larger than individual outside diameters of the carbon fibers.

9. The composite material according to claim 8 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds, which have different decomposition temperatures.

10. The composite material according to claim 1 , wherein the matrix comprises an organic polymer.

11. The composite material according to claim 1 , wherein the matrix comprises an inorganic material.

12. The composite material according to claim 1 , wherein the matrix comprises a metal.

13. The composite material according to claim 1 , wherein the composite material further comprises at least one filling agent selected from the group consisting of metallic minute particles, silica, calcium carbonate, magnesium carbonate, carbon black, glass fiber and another type of carbon fibers different from the carbon fibrous structures.

14. The composite material according to claim 2 , wherein I D /I G of the carbon fibrous structures determined by Raman spectroscopy is not more than 0.2, wherein I D is peak intensity at 1360 cm −1 and I G is peak at 1580 cm −1 .

15. The composite material according to claim 14 , wherein I D /I G of the carbon fibrous structures determined by Raman spectroscopy is not more than 0.1.

16. The composite material according to claim 15 , wherein the carbon fibrous structures have a combustion initiation temperature in air of not less than 750° C.

17. The composite material according to claim 16 , wherein a diameter of the granular part is larger than individual outside diameters of the carbon fibers.

18. The composite material according to claim 17 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds, which have different decomposition temperatures.

19. The composite material according to claim 1 , wherein the carbon fibrous structures have a bulk density of 0.0001–0.05 g/cm 3 .

20. The composite material according to claim 19 , wherein the carbon fibrous structure have a bulk density of 0.001–0.02 g/cm 3 .

21. The composite material according to claim 20 , wherein I D /I G of the carbon fibrous structures determined by Raman spectroscopy is not more than 0.2, wherein I D is peak intensity at 1360 cm −1 and I G is peak at 1580 cm −1 .

22. The composite material according to claim 21 , wherein I D /I G of the carbon fibrous structures determined by Raman spectroscopy is not more than 0.1.

23. The composite material according to claim 22 , wherein the carbon fibrous structures have a combustion initiation temperature in air of not less than 750° C.

24. The composite material according to claim 23 , wherein a diameter of the granular part is larger than individual outside diameters of the carbon fibers.

25. The composite material according to claim 24 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds, which have different decomposition temperatures.

26. The composite material according to claim 19 , wherein I D /I G of the carbon fibrous structures determined by Raman spectroscopy is not more than 0.2, wherein I D is peak intensity at 1360 cm −1 and I G is peak at 1580 cm −1 .

27. The composite material according to claim 26 , wherein I D /I G of the carbon fibrous structures determined by Raman spectroscopy is not more than 0.1.

28. The composite material according to claim 27 , wherein the carbon fibrous structures have a combustion initiation temperature in air of not less than 750° C.

29. The composite material according to claim 28 , wherein a diameter of the granular part is larger than individual outside diameters of the carbon fibers.

30. The composite material according to claim 29 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds, which have different decomposition temperatures.

31. The composite material according to claim 1 , wherein I D /I G of the carbon fibrous structures determined by Raman spectroscopy is not more than 0.2, wherein I D is peak intensity at 1360 cm −1 and I G is peak at 1580 cm −1 .

32. The composite material according to claim 31 , wherein I D /I G of the carbon fibrous structures determined by Raman spectroscopy is not more than 0.1.

33. The composite material according to claim 32 , wherein the carbon fibrous structures have a combustion initiation temperature in air of not less than 750° C.

34. The composite material according to claim 33 , wherein a diameter of the granular part is larger than individual outside diameters of the carbon fibers.

35. The composite material according to claim 34 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds, which have different decomposition temperatures.

36. The composite material according to claim 1 , wherein the carbon fibrous structures have a combustion initiation temperature in air of not less than 750° C.37.

37. The composite material according to claim 1 , wherein a diameter of the granular part is larger than individual outside diameters of the carbon fibers.

38. 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.