Method for producing acrylonitrile-based fiber

Patent metadata

Field	Value
Publication number	US-11286580-B2
Application number	US-201816491476-A
Country	US
Kind code	B2
Filing date	Sep 27, 2018
Priority date	Sep 29, 2017
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

The present invention relates to a method for producing an acrylonitrile-based fiber, the method including: providing a polymer solution including an acrylonitrile-based copolymer containing a carboxylic acid group; mixing 100 parts by weight of the polymer solution with 1 to 6 parts by weight of a hydrophilization solution containing an organic solvent and ammonia water in a weight ratio of 95:5 to 60:40 to prepare a spinning stock solution; and spinning the spinning stock solution. The method controls the viscosity of the spinning stock solution to improve the stretchability and strength of the acrylonitrile-based fiber, and suppresses the occurrence of gelation.

First claim

The invention claimed is:

1. A method for producing an acrylonitrile-based fiber, the method comprising:
preparing a polymer solution comprising an acrylonitrile-based copolymer containing a carboxylic acid group, wherein the concentration of the acrylonitrile-based copolymer in the polymer solution is 15 to 25 wt % based on a total weight of the polymer solution;
mixing 100 parts by weight of the polymer solution with 1 to 6 parts by weight of a hydrophilization solution comprising an organic solvent and ammonia water in a weight ratio of 95:5 to 60:40 to prepare a spinning stock solution, wherein the hydrophilization solution comprises the organic solvent and the ammonia water in a weight ratio of 93:7 to 70:30; and
spinning the spinning stock solution to produce the acrylonitrile-based fiber.

2. The method of claim 1 , wherein the equivalent ratio of ammonia (NH 3 ) in the ammonia water to the carboxylic acid group is 2:1 to 1.5:1.

3. The method of claim 1 , wherein the acrylonitrile-based copolymer is prepared by polymerizing a monomer mixture comprising:
90 to 99.9 parts by weight of an acrylonitrile-based monomer; and
0.1 to 10 parts by weight of a carboxylic acid-based monomer.

4. The method of claim 3 , wherein the carboxylic acid-based monomer is one or more selected from the group consisting of an itaconic acid, an acrylic acid and a methacrylic acid.

5. A method for producing a carbon fiber, the method comprising:
producing an acrylonitrile-based fiber according to claim 1 ;
subjecting the acrylonitrile-based fiber to flame retardation treatment; and
carbonizing the acrylonitrile-based fiber subjected to the flame retardation treatment.

6. The method of claim 1 , wherein the spinning comprises at least one cycle of a coagulation process, a washing process and a stretching process.

7. The method of claim 6 , wherein a total number of cycles thereof is 3 to 20 times.

8. The method of claim 1 , wherein the organic solvent is dimethyl sulfoxide.

Assignees

• Lg Chemical Ltd

Inventors

• Kim Sang Jin
• Bak Chang Hong
• Han Hye Jin
• Jo Ki Yeon
• Cho Jeong Hun
• Cho Joon Hee

Classifications

• D10B2321/10

  polymers of unsaturated nitriles, e.g. polyacrylonitrile, polyvinylidene cyanide · CPC title

• C08F222/30

  Nitriles · CPC title

• D01D5/04

  Dry spinning methods {(D01D5/0038 takes precedence)} · CPC title

• D01F6/18 Primary

  from polymers of unsaturated nitriles, e.g. polyacrylonitrile, polyvinylidene cyanide · CPC title

• D01D5/06 Primary

  Wet spinning methods {(D01D5/0046 takes precedence)} · CPC title