Liquid crystalline polyester fiber and method for producing the same

Patent metadata

Field	Value
Publication number	US-11686017-B2
Application number	US-201816623057-A
Country	US
Kind code	B2
Filing date	Jul 20, 2018
Priority date	Jul 24, 2017
Publication date	Jun 27, 2023
Grant date	Jun 27, 2023

Abstract

A liquid-crystal polyether fiber with high tensile strength has an ash content of 0.3 percent by weight or less, a degree of fusion (f) of 3 or less, and a tensile strength of 18 cN/dtex or more. The liquid-crystal polyether fiber has few residues of an anti-fusion agent and causes no fusion between filaments.

First claim

The invention claimed is:

1. A method for manufacturing a liquid crystalline polyester fiber, the method comprising:
attaching a water-soluble alkali metal halide salt to a raw spun yarn of the liquid crystalline polyester fiber before performing a heat treatment,
wherein the liquid crystalline polyester fiber has an ash content of 0.1% by weight or less and a degree of fusion (f) of 1.5 or less, and
an amount of the water-soluble alkali metal halide salt attached to the raw spun yarn is 0.1% by weight or more and 4% by weight or less with respect to a total weight of the raw spun yarn.

2. The method of claim 1 , further comprising:
washing the water-soluble alkali metal halide salt after the heat treatment.

3. The method of claim 1 , wherein
the amount of the water-soluble alkali metal halide salt attached to the raw spun yarn is 0.1% by weight or more and 3% by weight or less with respect to the total weight of the raw spun yarn.

4. The method of claim 1 , wherein the water-soluble alkali metal halide salt comprises at least one selected from the group consisting of lithium chloride, sodium chloride, potassium chloride, lithium bromide, sodium bromide, potassium bromide, lithium iodide, sodium iodide, and potassium iodide.

5. A method for manufacturing a composite material, comprising:
manufacturing a liquid crystalline polyester fiber by the method of claim 1 ; and
impregnating a matrix resin into the liquid crystalline polyester fiber.

6. The method of claim 1 , wherein the water-soluble alkali metal salt comprises at least one selected from the group consisting of sodium iodide, potassium iodide, sodium chloride, and potassium chloride.

7. The method of claim 3 , wherein the water-soluble alkali metal salt comprises at least one selected from the group consisting of sodium iodide, potassium iodide, sodium chloride, and potassium chloride.

8. A method for manufacturing a liquid crystalline polyester fiber, the method comprising:
attaching an aqueous solution of a water-soluble alkali metal halide salt to a raw spun yarn of the liquid crystalline polyester fiber;
drying the raw spun yarn to precipitate the solid alkali metal halide salt; and subsequently
performing a heat treatment,
wherein the liquid crystalline polyester fiber has an ash content of 0.1% by weight or less and a degree of fusion (f) of 1.5 or less, and
an amount of the water-soluble alkali metal halide salt attached to the raw spun yarn is 0.1% by weight or more and 4% by weight or less with respect to a total weight of the raw spun yarn.

9. The method of claim 8 , further comprising:
washing the water-soluble alkali metal halide salt after the heat treatment.

10. The method of claim 1 , wherein the liquid crystalline polyester fiber has a tensile strength of 18 cN/dtex or more.

Assignees

• Kuraray Co

Inventors

• TONOSAKI Hiroki
• Katayama Takashi
• Ide Junya
• Ikehata Keiichi

Classifications

• D01F6/62 Primary

  from polyesters · CPC title

• B08B3/12

  by sonic or ultrasonic vibrations · CPC title

• D06M11/13

  Ammonium halides or halides of elements of Groups 1 or 11 of the Periodic Table · CPC title

• D06M11/11

  with halogen acids or salts thereof · CPC title

• D01F6/625

  derived from hydroxy-carboxylic acids, e.g. lactones · CPC title