Carbon fibrous structure

Abstract

The present invention provides a carbon fibrous structure comprising a three dimensional network of carbon fibers, said carbon fibers each having an outside diameter of 15-100 nm, and said fibrous structure comprising a granular part with which said carbon fibers are bound in a state that said carbon fibers extend outwardly from the granular part, the granular part being produced in a growth process of the carbon fibers, and a method for making the same.

1 . A carbon fibrous structure comprising a three dimensional network of carbon fibers, said carbon fibers each having an outside diameter of 15-100 nm, and said fibrous structure comprising a granular part with which said carbon fibers are bound in a state that said carbon fibers extend outwardly from the granular part, the granular part being produced in a growth process of the carbon fibers.  
     
     
         2 . The carbon fibrous structure according to  claim 1 , wherein said carbon fibrous structure has an area based circle-equivalent mean diameter of 50-100 μm.  
     
     
         3 . The carbon fibrous structure according to  claim 2 , wherein said carbon fibrous structure has a bulk density of 0.0001-0.05 g/cm 3 .  
     
     
         4 . The carbon fibrous structure according to  claim 3 , wherein said carbon fibrous structure has a bulk density of 0.001-0.02 g/cm 3 .  
     
     
         5 . The carbon fibrous structure according to  claim 4 , wherein I D /I G  of said carbon fibrous structure 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 intensity at 1580 cm −1 .  
     
     
         6 . The carbon fibrous structure according to  claim 5 , wherein I D /I G  of said carbon fibrous structure determined by Raman spectroscopy is not more than 0.1.  
     
     
         7 . The carbon fibrous structure according to  claim 6 , wherein said carbon fibrous structure has a combustion initiation temperature in air of not less than 750° C.  
     
     
         8 . The carbon fibrous structure according to  claim 7 , wherein a diameter of the granular particle part is larger than individual outside diameters of the carbon fibers.  
     
     
         9 . The carbon fibrous structure 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 carbon fibrous structure according to  claim 2 , wherein I D /I G  of said carbon fibrous structure 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 intensity at 1580 cm −1 .  
     
     
         11 . The carbon fibrous structure according to  claim 10 , wherein I D /I G  of said carbon fibrous structure determined by Raman spectroscopy is not more than 0.1.  
     
     
         12 . The carbon fibrous structure according to  claim 11 , wherein said carbon fibrous structure has a combustion initiation temperature in air of not less than 750° C.  
     
     
         13 . The carbon fibrous structure according to  claim 12 , wherein a diameter of the granular particle part is larger than individual outside diameters of the carbon fibers.  
     
     
         14 . The carbon fibrous structure according to  claim 13 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds which have different decomposition temperatures.  
     
     
         15 . The carbon fibrous structure according to  claim 1 , wherein said carbon fibrous structure has a bulk density of 0.0001-0.05 g/cm 3 .  
     
     
         16 . The carbon fibrous structure according to  claim 15 , wherein said carbon fibrous structure has a bulk density of 0.001-0.02 g/cm 3 .  
     
     
         17 . The carbon fibrous structure according to  claim 16 , wherein I D /I G  of said carbon fibrous structure 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 intensity at 1580 cm −1 .  
     
     
         18 . The carbon fibrous structure according to  claim 17 , wherein I D /I G  of said carbon fibrous structure determined by Raman spectroscopy is not more than 0.1.  
     
     
         19 . The carbon fibrous structure according to  claim 18 , wherein said carbon fibrous structure has a combustion initiation temperature in air of not less than 750° C.  
     
     
         20 . The carbon fibrous structure according to  claim 19 , wherein a diameter of the granular particle part is larger than individual outside diameters of the carbon fibers.  
     
     
         21 . The carbon fibrous structure according to  claim 20 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds which have different decomposition temperatures.  
     
     
         22 . The carbon fibrous structure according to  claim 15 , wherein I D /I G  of said carbon fibrous structure 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 intensity at 1580 cm −1 .  
     
     
         23 . The carbon fibrous structure according to  claim 22 , wherein I D /I G  of said carbon fibrous structure determined by Raman spectroscopy is not more than 0.1.  
     
     
         24 . The carbon fibrous structure according to  claim 23 , wherein said carbon fibrous structure has a combustion initiation temperature in air of not less than 750° C.  
     
     
         25 . The carbon fibrous structure according to  claim 24 , wherein a diameter of the granular particle part is larger than individual outside diameters of the carbon fibers.  
     
     
         26 . The carbon fibrous structure according to  claim 25 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds which have different decomposition temperatures.  
     
     
         27 . The carbon fibrous structure according to  claim 1 , wherein I D /I G  of said carbon fibrous structure 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 intensity at 1580 cm −1 .  
     
     
         28 . The carbon fibrous structure according to  claim 27 , wherein I D /I G  of said carbon fibrous structure determined by Raman spectroscopy is not more than 0.1.  
     
     
         29 . The carbon fibrous structure according to  claim 28 , wherein said carbon fibrous structure has a combustion initiation temperature in air of not less than 750° C.  
     
     
         30 . The carbon fibrous structure according to  claim 29 , wherein a diameter of the granular particle part is larger than individual outside diameters of the carbon fibers.  
     
     
         31 . The carbon fibrous structure according to  claim 30 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds which have different decomposition temperatures.  
     
     
         32 . The carbon fibrous structure according to  claim 1 , wherein said carbon fibrous structure has a combustion initiation temperature in air of not less than 750° C.  
     
     
         33 . The carbon fibrous structure according to  claim 32 , wherein a diameter of the granular particle part is larger than individual outside diameters of the carbon fibers.  
     
     
         34 . The carbon fibrous structure according to  claim 33 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds which have different decomposition temperatures.  
     
     
         35 . The carbon fibrous structure according to  claim 1 , wherein a diameter of the granular particle part is larger than individual outside diameters of the carbon fibers.  
     
     
         36 . The carbon fibrous structure according to  claim 35 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds which have different decomposition temperature.  
     
     
         37 . The carbon fibrous structure according to  claim 1 , wherein the carbon fibers are produced using as carbon sources at least two carbon compounds which have different decomposition temperature.  
     
     
         38 . A method for forming a carbon fibrous structure having a granular core to which a plurality of carbon fibers are attached, the method comprising: 
 heating a mixture of a carbon source and a catalyst at a constant temperature in a range of 800-1300° C. to produce a first intermediate, wherein the carbon source comprises at least two carbon compounds having different decomposition temperatures or the carbon source comprises a carbon compound that can produce, in the heating, at least two carbon components having different decompositions temperatures;    heating the first intermediate at a constant temperature in a range of 800-1200° C. to produce a second intermediate; and    heating the second intermediate at a constant temperature in a range of 2400-3000° C. to produce the carbon fibrous structure.