Method for production of carbon fiber bundle

Patent metadata

Field	Value
Publication number	US-9890481-B2
Application number	US-201314646962-A
Country	US
Kind code	B2
Filing date	Nov 22, 2013
Priority date	Nov 22, 2012
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

The purpose of the present invention is to provide a method whereby deposits which have occurred on the surfaces of a fiber bundle during flameproofing treatment of a carbon fiber-precursor acrylic fiber bundle can be efficiently removed prior to carbonization treatment at high temperature. The method for production of carbon fiber bundle includes a step in which, after a carbon fiber-precursor acrylic fiber bundle has been heated and undergone flameproofing treatment, the fiber bundle is subjected to a plasma treatment involving contact with a plasma gas in gas phase, or to an ultraviolet treatment involving irradiation with ultraviolet in gas phase; and a step in which the fiber bundle having undergone the plasma treatment or the ultraviolet treatment is subjected to a carbonization treatment.

First claim

The invention claimed is:

1. A method for producing a carbon fiber bundle, the method comprising:
performing a plasma treatment of bringing a fiber bundle A, which is a carbon fiber precursor acrylic fiber bundle having undergone flameproofing treatment by heating, into contact with a plasma gas in gas phase; and
performing carbonization treatment of a fiber bundle B, which has been obtained by the plasma treatment,
wherein the plasma gas is generated by introducing a mixed gas of inactive gas in a range of 97.00 volume % to 99.99 volume % and active gas in a range of 0.0100 volume % to 3.000 volume % into a plasma generation device.

2. The method for producing a carbon fiber bundle according to claim 1 , wherein the density of the fiber bundle A to be subjected to the plasma treatment is in a range of 1.30 g/cm 3 to 1.50 g/cm 3 .

3. The method for producing a carbon fiber bundle according to claim 1 , wherein the density of the fiber bundle A to be subjected to the plasma treatment is in a range of 1.50 g/cm 3 to 1.70 g/cm 3 .

4. The method for producing a carbon fiber bundle according to claim 1 , wherein the plasma gas is ejected from an ejection port and brought into contact with the fiber bundle A such that the distance d between the ejection port of the plasma gas of a plasma generation device and the fiber bundle A is in a range of 0.5 mm to 10 mm.

5. The method for producing a carbon fiber bundle according to claim 2 , wherein the fiber bundle A is made into a sheet form having a fineness per unit width in a range of 500 dtex/mm to 5000 dtex/mm, and the fiber bundle in the sheet form is brought into contact with the plasma gas.

6. The method for producing a carbon fiber bundle according to claim 3 , wherein the fiber bundle A is made into a sheet form having a fineness per unit width in a range of 500 dtex/mm to 5000 dtex/mm, and the fiber bundle in the sheet form is brought into contact with the plasma gas.

7. The method for producing a carbon fiber bundle according to claim 1 , wherein the plasma gas is ejected from each direction facing to each side of the fiber bundle in the sheet form.

8. The method for producing a carbon fiber bundle according to claim 2 , wherein the absorbance, which is measured by the measuring method below, of the fiber bundle B to be subjected to the carbonization treatment satisfies condition 1 and/or condition 2 as follows:
condition 1: absorbance at 240 nm of the wavelength is 1.5 or less;
condition 2: absorbance at 278 nm of the wavelength is 1.0 or less.

9. The method for producing a carbon fiber bundle according to claim 3 , wherein the absorbance, which is measured by the measuring method below, of the fiber bundle B to be subjected to the carbonization treatment satisfies condition 1 and/or condition 2 as follows:
condition 1: absorbance at 240 nm of the wavelength is 0.20 or less;
condition 2: absorbance at 278 nm of the wavelength is 0.15 or less.

10. The method for producing a carbon fiber according to claim 2 , wherein the total number of cavities and particles having a size of 1 μm or more which are present on the surface of filaments that are present on the surface of the fiber bundle B to be subjected to the carbonization treatment is 5 or less per 100 μm 2 area of the surface of the filaments.

11. The method for producing a carbon fiber according to claim 3 , wherein the total number of cavities and particles having a size of 1 μm or more which are present on the surface of filaments that are present on the surface of the fiber bundle B to be subjected to the carbonization treatment is 5 or less per 100 μm 2 area of the surface of the filaments.

12. The method for producing a carbon fiber according to claim 5 , wherein the total number of cavities and particles having a size of 1 μm or more which are present on the surface of filaments that are present on the surface of the fiber bundle B to be subjected to the carbonization treatment is 5 or less per 100 μm 2 area of the surface of the filaments.

13. The method for producing a carbon fiber according to claim 6 , wherein the total number of cavities and particles having a size of 1 μm or more which are present on the surface of filaments that are present on the surface of the fiber bundle B to be subjected to the carbonization treatment is 5 or less per 100 μm 2 area of the surface of the filaments.

14. A method for producing a carbon fiber bundle, the method comprising:
heating a fiber bundle of a carbon fiber precursor to perform a flame proofing treatment;
rendering the density of the fiber bundle in a range of 1.30 g/cm 3 to 1.50 g/cm 3 by the flameproofing treatment to obtain a fiber bundle C; and
subjecting the fiber bundle C to carbonization treatment;
wherein the absorbance, which is measured by the measuring method below, of the fiber bundle C to be subjected to carbonization treatment satisfies condition 1 and/or condition 2 as follows:
condition 1: absorbance at 240 nm of the wavelength is 1.5 or less;
condition 2: absorbance at 278 nm of the wavelength is 1.0 or less, and
the fiber bundle C to be subjected to the carbonization treatment is a fiber bundle that is obtained by performing ultraviolet ray treatment comprising irradiating the fiber bundle with an ultraviolet ray in a gas phase, after the flameproofing treatment.

15. A method for producing a carbon fiber bundle, the method comprising:
heating a fiber bundle of a carbon fiber precursor to perform a flame proofing treatment;
rendering the density of the fiber bundle in a range of 1.50 g/cm 3 to 1.70 g/cm 3 after the flameproofing treatment to obtain a fiber bundle C; and
subjecting the fiber bundle C to carbonization treatment;
wherein:
the total number of cavities and particles having a size of 1 μm or more which are present on the surface of filaments that are present on the surface of the fiber bundle C to be subjected to the carbonization treatment is 5 or less per 100 μm 2 area of the surface of the filaments;
the fiber bundle C to be subjected to the carbonization treatment is a fiber bundle that is obtained by performing plasma treatment comprising contacting the fiber bundle with a plasma gas in a gas phase, after the flameproofing treatment; and
the plasma gas is generated by introducing a mixed gas of inactive gas in a range of 97.00 volume % to 99.99 volume % and active gas in a range of 0.0100 volume % to 3.000 volume % into a plasma generation device.

16. The method for producing a carbon fiber bundle according to claim 14 , wherein luminous energy per unit area of the ultraviolet ray irradiated in the ultraviolet ray treatment is in a range of 3 mW/cm 2 to 10 mW/cm 2 .

Assignees

• Mitsubishi Chem Corp

Inventors

• Hamada Mitsuhiro
• Nakao Hiroyuki
• Aso Hiromi
• Kageyama Yoshitaka

Classifications

• D01D10/00 Primary

  Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected (finishing D02J) · CPC title

• D06M10/001

  Treatment with visible light, infrared or ultraviolet, X-rays · CPC title

• D01F9/225

  from stabilised polyacrylonitriles · CPC title

• D06M10/025

  Corona discharge or low temperature plasma · CPC title

• D01F11/06

  of macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title