Claims
- 1. (Amended) Fine carbon fibers having a fiber diameter of 1 μm or less, an interlayer distance d002 between carbon layers as determined by an X-ray diffraction method of 0.335 to 0.342 nm or less and satisfying d002<0.3448-0.0028 (log φ) where φ stands for the diameter of the carbon fibers and the units of d002 and 4 are nm, and a thickness Lc of the crystal in the C axis direction of 40 nm or less.
- 2. Fine carbon fibers according to claim 1, wherein the interlayer distance d002 between carbon layers satisfies d002<0.3444-0.0028 (log φ).
- 3. Fine carbon fibers according to claim 1, wherein the R value of Raman spectrum is 0.5 or more and a peak width at maximum peak height of the peak at 1580 cm−1 of the spectrum is 20 to 40 cm−1.
- 4. Fine carbon fibers having a fiber diameter of 1 μm or less and containing boron in crystals in the carbon fibers.
- 5. Fine carbon fibers according to any one of claims 1 through 3 containing boron in crystals in the fibers.
- 6. Fine carbon fibers according to claim 5, which contain boron in an amount of 0.1-3 mass %.
- 7. Fine carbon fibers according to claim 5, which have a fiber diameter of 0.01-1 μm and an aspect ratio of 10 or more.
- 8. Fine carbon fibers according to claim 7, which have a powder resistance of 0.01 Ω·cm or less in the direction normal to the pressing direction when the fibers are pressed to a density of 0.8 g/cm3.
- 9. Fine carbon fibers according to claim 5, which are vapor-grown carbon fibers.
- 10. A process for producing fine carbon fibers which comprises adding fine carbon fibers having a diameter of 1 μm or less with boron or a boron compound and heat treating the fine carbon fibers to a temperature of 2000° C. or higher.
- 11. A process for producing fine carbon fibers having a diameter of 1 μm or less which comprises
adding fine carbon fibers with boron or a boron compound; regulating the bulk density of the fine carbon fibers to 0.05 g/cm3 or more; and heat treating said fine carbon fibers to a temperature of 2000° C. or higher while said bulk density is maintained.
- 12. A process for producing fine carbon fibers according to claim 10 or 11, wherein the amount of the boron or boron compound is 0.1-10 mass % in terms of boron atoms with respect to the carbon fibers.
- 13. A process for producing fine carbon fibers according to claim 12, wherein the fine carbon fibers to which the boron is mixed have a diameter of 0.01 to 1 μm and an aspect ratio of 10 or more.
- 14. A process for producing fine carbon fibers according to claim 13, wherein the fine carbon fibers to which the boron or boron compound is mixed are a vapor-grown carbon fibers.
- 15. A process for producing fine carbon fibers according to claim 14, wherein the fine carbon fibers prior to said heat treatment to which the boron or boron compound is to be added are a fired product of vapor-grown carbon fibers fired after growth.
- 16. A process for producing fine carbon fibers in according to claim 14, wherein the fine carbon fibers prior to said heat treatment to which the boron or boron compound is to be added are unfired product of vapor-grown carbon fibers not fired after growth.
- 17. A battery electrode containing fine carbon fibers as recited in any one of claims 1 through 3.
- 18. A battery electrode containing fine carbon fibers as recited in claim 5.
- 19. A battery electrode containing fine carbon fibers as recited in claim 6 or 7.
- 20. A battery electrode containing fine carbon fibers as recited in claim 8 or 9.
- 21. A battery electrode according to claim 17, wherein the fine carbon fibers are contained in an amount of 0.1 to 20 mass %.
- 22. A battery electrode according to claim 18, wherein the fine carbon fibers are contained in an amount of 0.1 to 20 mass %.
- 23. A battery electrode according to claim 19, wherein the fine carbon fibers are contained in an amount of 0.1 to 20 mass %.
- 24. A battery electrode according to claim 20, wherein the fine carbon fibers are contained in an amount of 0.1 to 20 mass %.
Priority Claims (2)
Number |
Date |
Country |
Kind |
11-81260 |
Mar 1999 |
JP |
|
11-307867 |
Oct 1999 |
JP |
|
REFERENCE TO THE RELATED APPLICATION
[0001] This application is entitled to the benefit of the priority of U.S. Provisional Patent Application Ser. No. 60/145,266 filed on Jul. 26, 1999.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60145266 |
Jul 1999 |
US |
Divisions (1)
|
Number |
Date |
Country |
Parent |
09937079 |
Sep 2001 |
US |
Child |
10268707 |
Oct 2002 |
US |