Polycarbonate fibers, fiber structure and resin composite body

Patent metadata

Field	Value
Publication number	US-12559865-B2
Application number	US-202217697083-A
Country	US
Kind code	B2
Filing date	Mar 17, 2022
Priority date	Sep 27, 2019
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

Provided are a polycarbonate fiber having a specific orientation degree and/or a specific birefringence value, a fiber structure as well as a resin composite body. The polycarbonate fiber may have an orientation degree (ft) of lower than 0.70, the orientation degree (ft) being defined by the following formula: ft=1−(1.0/C) 2 , C: obtained sonic velocity (km/sec), and may have a birefringence value of 0.04 or lower. The polycarbonate fiber may comprise a polycarbonate resin having a number-average molecular weight (Mn) of from 12000 to 40000 and/or a weight-average molecular weight (Mw) of from 25000 to 80000.

First claim

What is claimed is:

1 . A polycarbonate fiber having an orientation degree (ft) of lower than 0.70 and comprising a polycarbonate resin having a weight-average molecular weight (Mw) of from 45000 to 80000, wherein the orientation degree (ft) is defined by the following formula:
ft= 1−(1.0/ C ) 2
where C is sonic velocity in terms of km/see of the polycarbonate fiber.

2 . The polycarbonate fiber according to claim 1 , wherein the polycarbonate fiber has a birefringence value of 0.040 or lower.

3 . The polycarbonate fiber according to claim 1 , wherein the polycarbonate resin having has a number-average molecular weight (Mn) of from 12000 to 40000.

4 . The polycarbonate fiber according to claim 3 , wherein the polycarbonate resin has a molecular weight distribution (Mw/Mn) of from 2.0 to 4.0.

5 . A polycarbonate fiber having a birefringence value of 0.040 or lower and comprising a polycarbonate resin having a weight-average molecular weight (Mw) of from 45000 to 80000.

6 . The polycarbonate fiber according to claim 5 , wherein the polycarbonate resin has a molecular weight distribution (Mw/Mn) of from 2.0 to 4.0.

7 . The polycarbonate fiber according to claim 1 , wherein the polycarbonate fiber has an elastic modulus of 30 cN/dtex or lower.

8 . The polycarbonate fiber according to claim 1 , wherein the polycarbonate fiber has a coefficient of variation in a fiber diameter of 15% or lower.

9 . The polycarbonate fiber according to claim 1 , wherein the polycarbonate fiber has a single fiber fineness of 10 dtex or smaller.

10 . The polycarbonate fiber according to claim 1 , wherein the polycarbonate fiber has an elongation at break of 20% or higher.

11 . The polycarbonate fiber according to claim 1 , wherein the polycarbonate resin includes bisphenol-A units at a molar proportion of 65% or higher based on a total amount of monomer units in the polycarbonate resin.

12 . The polycarbonate fiber according to claim 1 , wherein the polycarbonate fiber comprises a phosphorus-based flame retardant.

13 . The polycarbonate fiber according to claim 12 , wherein the polycarbonate fiber comprises at least one phosphorus-based flame retardant selected from the group consisting of a phosphoric acid ester-based flame retardant, a phosphoric acid salt-based flame retardant, and a phosphazene-based flame retardant.

14 . A fiber structure, comprising the polycarbonate fiber according to claim 1 .

15 . A fiber structure, comprising the polycarbonate fiber according to claim 5 .

16 . The fiber structure according to claim 14 , wherein the fiber structure is commingled fibers, a woven fabric, or a non-woven fabric.

17 . A method for producing the polycarbonate fiber according to claim 1 , the method comprising:
melt-kneading the polycarbonate resin at a temperature of 305° C. or higher to give a molten polymer; discharging the molten polymer through a spinning nozzle at a predetermined rate to give as-spun fibers; and winding the as-spun fibers at a predetermined winding speed.

18 . The polycarbonate fiber according to claim 5 , wherein the polycarbonate resin has a number-average molecular weight (Mn) of from 12000 to 40000.

19 . The polycarbonate fiber according to claim 1 , wherein the polycarbonate resin has a branching degree of less than 0.1 mol %.

20 . The polycarbonate fiber according to claim 1 , wherein the polycarbonate fiber has an elongation at break of 80% or higher.

Assignees

• Kuraray Co

Inventors

• Tsudaka Takeshi
• Kamada Hideki
• Endo Ryokei

Classifications

• D10B2401/20

  optical · CPC title

• D10B2331/042

  aromatic polyesters, e.g. vectran · CPC title

• D01F1/07 Primary

  for making fire- or flame-proof filaments · CPC title

• D01D1/04

  Melting filament-forming substances · CPC title

• C08L69/00

  Compositions of polycarbonates; Compositions of derivatives of polycarbonates · CPC title