Carbon-based material and method of producing the same, and composite material and method of producing the same

1. A method of producing a carbon-based material, the method comprising:

(a) mixing an elastomer and at least a first carbon material and dispersing the first carbon material by applying a shear force to obtain a composite elastomer;

(b) heat-treating the composite elastomer to vaporize the elastomer included in the composite elastomer to obtain a second carbon material; and

(c) heat-treating the second carbon material together with a substance including an element Y and having a melting point lower than a melting point of the first carbon material to vaporize the substance including the element Y, to obtain the carbon-based material, wherein

the step (b) is performed in the presence of a substance including an element X such that the element X bonds to a carbon atom of the first carbon material,

the element X is oxygen or nitrogen,

the element Y is magnesium,

the heat treatment temperature in step (c) is equal to or higher than the vaporization temperature of magnesium and is not higher than 570° C., and

the heat treatment of step (c) is carried out in a nitrogen atmosphere.

2. The method of producing a carbon-based material as defined in claim 1 ,

wherein the composite elastomer includes the substance including the element X, and

wherein the element X bonds to the carbon atom of the first carbon material by the heat treatment in the step (b).

3. The method of producing a carbon-based material as defined in claim 1 ,

wherein the step (b) is performed in an atmosphere containing the substance including the element X so that the element X bonds to the carbon atom of the first carbon material.

4. The method of producing a carbon-based material as defined in claim 1 ,

wherein the composite elastomer includes the substance including the element Y.

5. The method of producing a carbon-based material as defined in claim 1 ,

wherein, in the step (c), the substance including the element Y is disposed in a heat treatment furnace together with the second carbon material and vaporized by the heat treatment.

6. The method of producing a carbon-based material as defined in claim 1 ,

wherein the first carbon material is carbon black.

7. The method of producing a carbon-based material as defined in claim 1 ,

wherein the first carbon material is carbon fiber.

8. The method of producing a carbon-based material as defined in claim 7 ,

wherein the carbon fiber is carbon nanofiber.

9. The method of producing a carbon-based material as defined in claim 8 ,

wherein the carbon nanofibers have an average diameter of 0.5 to 500 nm.

10. The method of producing a carbon-based material as defined in claim 1 ,

wherein the elastomer has a molecular weight of 5,000 to 5,000,000.

11. The method of producing a carbon-based 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 unsaturated bond or group having affinity to carbon nanofiber and selected from the group consisting of a double bond, a triple bond, and functional groups such as 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.

12. The method of producing a carbon-based 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 a pulsed nuclear magnetic resonance (NMR) technique of 100 to 3,000 μsec.

13. The method of producing a carbon-based 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 a pulsed nuclear magnetic resonance (NMR) technique of 100 to 2,000 μsec.

14. The method of producing a carbon-based material as defined in claim 1 ,

wherein the elastomer is natural rubber or nitrile butadiene rubber.

15. The method of producing a carbon-based material as defined in claim 1 ,

wherein the step (a) is performed by using an open-roll method with a roll distance of 0.5 mm or less.

16. The method of producing a carbon-based material as defined in claim 15 ,

wherein two rolls used in the open-roll method have a surface velocity ratio of 1.05 to 3.00.

17. The method of producing a carbon-based material as defined in claim 1 ,

wherein the step (a) is performed by using an internal mixing method.

18. The method of producing a carbon-based material as defined in claim 1 ,

wherein the step (a) is performed by using a multi-screw extrusion mixing method.

19. The method of producing a carbon-based material as defined in claim 1 ,

wherein the step (a) is performed at 0 to 50° C.

20. A method of producing a composite material, the method comprising:

(d) mixing the carbon-based material obtained by the method as defined in claim 1 with a matrix material, wherein the carbon-based material is mixed into a matrix material being aluminum or magnesium.

21. The method of producing a carbon-based material as defined in claim 1 , wherein the heat treatment temperature in step (b) is equal to or higher than the vaporization temperature of the elastomer and equal to or lower than 500° C.

22. The method of producing a composite material as defined in claim 20 , wherein the composite material has a compressive yield strength mean value greater than or equal to 430 MPa.