Carbon fiber composite material and process for producing the same

• US 20040241440A1
• Filed: 04/09/2004
• Published: 12/02/2004
• Est. Priority Date: 04/09/2003
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Nissin Kogyo Company Limited (Hitachi, Ltd.)
• Inventors: Noguchi, Toru, Fukazawa, Shigeru, Shimizu, Shuichi
• Granted Patent: US 7,785,701 B2
• Time in Patent Office: Days
• US Class Current: 428/364
• CPC Class Codes: B29C 48/40 using two or more parallel screws or at least two parallel non-intermeshing screws, e.g. twin screw extruders
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08J 2321/00 Characterised by the use of unspecified rubbers
• CPC Class Codes: C08J 5/005 Reinforced macromolecular compounds with nanosized materials, e.g. nanoparticles, nanofibres, nanotubes, nanowires, nanorods or nanolayered materials
• CPC Class Codes: C08J 5/042 with carbon fibres
• CPC Class Codes: C08K 2201/011 Nanostructured additives
• CPC Class Codes: C08K 7/06 Elements
• CPC Class Codes: C08K 7/24 inorganic
• CPC Class Codes: C08L 21/00 Compositions of unspecified rubbers
• CPC Class Codes: Y10S 428/903 Microfiber, less than 100 micron diameter
• CPC Class Codes: Y10S 977/778 within specified host or matrix material, e.g. nanocomposite films
• CPC Class Codes: Y10S 977/783 Organic host/matrix, e.g. lipid
• CPC Class Codes: Y10T 428/249924 Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
• CPC Class Codes: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix
• CPC Class Codes: Y10T 428/249945 Carbon or carbonaceous fiber
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber

Abstract

The present invention provides a carbon fiber composite material comprising an elastomer and a carbon nanofiber dispersed in the elastomer, wherein the elastomer has an unsaturated bond or a group, having affinity to the carbon nanofiber. Also disclosed is a process for producing the carbon fiber composite material.

Claims

1. A carbon fiber composite material comprising an elastomer and a carbon nanofiber dispersed in the elastomer,

wherein the elastomer has an unsaturated bond or a group, having affinity to the carbon nanofiber.

2. The carbon fiber composite material according to claim 1, wherein the elastomer has a weight average molecular weight of 5,000 to 5,000,000.

3. The carbon fiber composite material according to claim 1, wherein the elastomer has, in at least one of its main chain, side chains and terminal chains, at least one member selected from the group consisting of a double bond, a triple bond, 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.

4. The carbon fiber composite material according to claim 1, wherein the elastomer in the composite material is in its uncrosslinked form and has a spin-spin relaxation time (T2n) of its network component of 100 to 3,000 μ

sec as measured at 30°

C. by the Hahn-echo method using pulsed NMR technique.

5. The carbon fiber composite material according to claim 1, wherein the elastomer in the composite material is in its crosslinked form and has a spin-spin relaxation time (T2n) of its network component of 100 to 2,000 μ

sec as measured at 30°

C. by the Hahn-echo method using pulsed NMR technique.

6. The carbon fiber composite material according to claim 1, wherein the elastomer in the composite material is one of natural rubber (NR) and nitrile rubber (NBR).

9. The carbon fiber composite material according to claim 1, wherein the elastomer in the composite material is in its uncrosslinked form and the composite material has a flow temperature higher than the inherent flowing temperature of the elastomer by 20°

C. or more.

10. The carbon fiber composite material according to claim 1, wherein the carbon nanofiber has an average diameter of 0.5 to 500 nm.

7. A carbon fiber composite material comprising an elastomer and a carbon nanofiber dispersed in the elastomer, wherein the elastomer in the composite material is in its uncrosslinked form, and has a first spin-spin relaxation time (T2n) of 100 to 3,000 μ

sec and a second spin-spin relaxation time (T2nn) of being absent or 1,000 to 10,000 μ

sec, and a fraction (fnn) of components having the second spin-spin relaxation time of less than 0.2, as measured at 150°

C. by the Hahn-echo method using pulsed NMR technique.

23. The carbon fiber composite material according to claim 7, wherein the elastomer in the composite material is in its uncrosslinked form and the composite material has a flow temperature higher than the inherent flowing temperature of the elastomer by 20°

C. or more.

24. The carbon fiber composite material according to claim 7, wherein the carbon nanofiber has an average diameter of 0.5 to 500 nm.

8. A carbon fiber composite material comprising an elastomer and a carbon nanofiber dispersed in the elastomer, wherein the elastomer in the composite material is in its crosslinked form, and has a first spin-spin relaxation time (T2n) of 100 to 2,000 μ

sec and a second spin-spin relaxation time (T2nn) of being absent or 1,000 to 5,000 μ

sec, and a fraction (fnn) of components having the second spin-spin relaxation time of less than 0.2, as measured at 150°

C. by the Hahn-echo method using pulsed NMR technique.

25. The carbon fiber composite material according to claim 8, wherein the elastomer in the composite material is in its uncrosslinked form and the composite material has a flow temperature higher than the inherent flowing temperature of the elastomer by 20°

C. or more.

26. The carbon fiber composite material according to claim 8, wherein the carbon nanofiber has an average diameter of 0.5 to 500 nm.

11. A process for producing a carbon fiber composite material comprising dispersing a carbon nanofiber into an elastomer by shear force,

wherein the elastomer has an unsaturated bond or a group, having affinity to the carbon nanofiber.

12. The process according to claim 11, wherein the elastomer has a weight average molecular weight of 5,000 to 5,000,000.

13. The process for producing a carbon fiber composite material according to claim 11, wherein the elastomer has, in at least one of its main chain, side chains and terminal chains, at least one member selected from the group consisting of a double bond, a triple bond, 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.

14. The process for producing a carbon fiber composite material according to claim 11, wherein the elastomer in the composite material is in its uncrosslinked form and has a spin-spin relaxation time (T2n) of its network component of 100 to 3,000 μ

sec as measured at 30°

C. by the Hahn-echo method using pulsed NMR technique.

15. The carbon fiber composite material according to claim 11, wherein the elastomer in the composite material is one of natural rubber (NR) and nitrile rubber (NBR).

16. The process for producing a carbon fiber composite material according to claim 11, wherein the carbon nanofiber has an average diameter of 0.5 to 500 nm.

17. The process for producing a carbon fiber composite material according to claim 11, wherein the dispersing step is carried out in accordance with an open-roll method using two rolls with a roll distance of 0.5 mm or less.

18. The process for producing a carbon fiber composite material according to claim 17, wherein the two rolls have their surface velocity ratio of 1.05 to 3.00.

19. The process for producing a carbon fiber composite material according to claim 11, wherein the dispersing step is carried out by a closed kneading method with a rotor distance of 1 mm or less.

20. The process for producing a carbon fiber composite material according to claim 11, wherein the dispersing step is carried out by a multi-screw extruding kneading method with a screw distance of 0.3 mm or less.

21. The process for producing a carbon fiber composite material according to claim 11, wherein the dispersing step is carried out at a temperature of 0 to 50°

C.

22. The process for producing a carbon fiber composite material according to any one of claim 11, further comprising a step of crosslinking the elastomer in the composite material after the dispersing step.