Production of and drying of copolymer fibers

Patent metadata

Field	Value
Publication number	US-9903051-B2
Application number	US-201213349605-A
Country	US
Kind code	B2
Filing date	Jan 13, 2012
Priority date	Jan 13, 2011
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

The present invention concerns processes for reducing water in never-dried fiber comprising copolymer derived from the copolymerization of para-phenylenediamine, 5(6)-amino-2-(p-aminophenyl)benzimidazole; and terephthaloyl dichloride, the process having the following steps in a continuous process, (a) a step of drying a never-dried fiber at less than 100 C until the moisture content of the fiber is less than 60 weight percent; and (b) a step of further drying the fiber above 150° C. while the moisture content of the fiber is no more than 40 weight percent; and the fiber being further heated to at least 350° C. in either an additional continuous or separate step.

First claim

What is claimed:

1. A process for reducing water in never-dried fiber comprising copolymer derived from the copolymerization of para-phenylenediamine, 5(6)-amino-2-(p-aminophenyl)benzimidazole, and terephthaloyl dichloride, the process having the following steps in a continuous process,
(a) a step of drying in a dryer a never-dried fiber at less than 100° C. until the moisture content of the fiber is less than 60 weight percent; and
(b) a step of further drying the fiber in a separate heat setting device above 150° C. while the moisture content of the fiber is no more than 40 weight percent;
the fiber being further heated to at least 350° C. in either an additional continuous or separate step.

2. The process of claim 1 wherein in step (a) the fiber is dried at 50° C. or less.

3. The process of claim 1 wherein in step (a) the fiber is dried until the moisture content is less than 50%.

4. The process of claim 3 wherein in step (a) the fiber is dried until the moisture content is less than 40%.

5. The process of claim 2 wherein after step (a), the fiber is further dried at an additional step at less than 100° C. until moisture content is less than 50%, prior to step (b).

6. The process of claim 1 wherein after step (a) the fiber is further dried at an additional step at less than 150° C. until moisture content is less than 40%, prior to step (b).

7. The process of claim 1 , wherein the sulfur content of the fiber is greater than 0.1 weight percent.

8. The process of claim 1 , wherein the fiber is heated above 400° C. in the last step.

9. The process of claim 1 , wherein the fiber is heated in step (a) under a tension of at least 0.1 gpd.

10. The process of claim 1 , wherein the fiber is heated in the last step under a tension of less than 1 gpd.

11. The process of claim 1 , wherein the ratio of moles of 5(6)-amino-2-(p-aminophenyl) benzimidazole to the moles of para-phenylenediamine is 30/70 to 85/15.

12. The process of claim 11 wherein the ratio is 45/55 to 85/15.

13. The process of claim 1 , wherein the fiber is heated in an oven in step (a).

14. The process of claim 1 , wherein said fiber is heated by contacting said filaments with a hot surface.

15. A process for producing filaments comprising a copolymer derived from the copolymerization of para-phenylenediamine, 5(6)-amino-2-(p-aminophenyl)benzimidazole; and terephthaloyl dichloride, including the following steps in a continuous process:
(a) a step of spinning filaments into a coagulation bath from a sulfuric acid solution of the copolymer;
(b) a step of contacting the filaments with one or more of (i) wash and (ii) neutralization fluid; and
(c) a step of drying the filaments in a dryer at less than 100° C. until the moisture content of the fiber is less than 60 weight percent;
(d) a step of further drying the filaments in a separate heat setting device above 150° C. while the moisture content of the fiber is no more than 40 weight percent;
the filaments being further heated to at least 350° C. in either an additional continuous or separate step.

16. The process of claim 15 , wherein the filaments are heated above 400° C. in the last step.

17. The process of claim 15 , wherein the filaments are heated in step (c) under a tension of at least 0.1 gpd.

18. The process of claim 15 , wherein the filaments are heated in the last step under a tension of less than 1 gpd.

19. The process of claim 15 , wherein the sulfur content of the filaments is greater than 0.1 weight percent.

20. The process of claim 15 , wherein said filaments are heated by contacting said filaments with a hot surface.

Assignees

• Allen Steven R
• Newton Christopher William
• Du Pont

Inventors

• Allen Steven R
• Newton Christopher William

Classifications

• D01F6/805 Primary

  from aromatic copolyamides · CPC title

• D01D10/02

  Heat treatment (heating for finishing D02J13/00) · CPC title

• C08G73/18

  Polybenzimidazoles · CPC title

• D01D10/06

  Washing or drying · CPC title

• C08G69/32

  from aromatic diamines and aromatic dicarboxylic acids with both amino and carboxylic groups aromatically bound · CPC title