USRE37526EExpiredUtilityPatentIndex 60

Process for making high denier filaments of thermotropic liquid crystalline polymers and compositions thereof

Assignee: CELANESE ACETATE LLCPriority: Sep 10, 1998Filed: Oct 8, 1999Granted: Jan 22, 2002

Est. expirySep 10, 2018(expired)· nominal 20-yr term from priority

Inventors:FLINT JOHN ANTHONY JAFFE MICHAEL HAIDER M ISHAQ DIBIASE JOSEPH J CORNETTA JOHN EDWARD

D01F 6/84D01D 5/08Y10T428/2969Y10T428/2913D01F 6/82Y10T428/2964

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Claims

Abstract

The present invention discloses and claims a novel process for the formation of high denier as-spun and heat-treated filaments of a thermotropic liquid crystalline polymer. Preferred embodiments include process for the formation of as-spun and heat treated monofilaments of a few wholly aromatic polyesters and polyesteramides. The process involves (a) heating of a thermotropic liquid crystalline polymer to above its melting transition temperature; (b) passing said molten polymer through an extrusion chamber equipped with an extrusion capillary of an aspect ratio of greater than about 1 and less than about 15 to form a filament; and (c) winding the filament at a draw-down ratio of at least about 4. The filaments so formed are of at least 50 denier per filament (dpf) and feature essentially uniform molecular orientation across the cross-section. In a final optional step, the filaments are heat treated in stages to form filaments exhibiting excellent tensile properties. Both as-spun and heat-treated filaments feature remarkably good tensile properties retaining at least 80 to 90 percent of the properties expected of conventional low denier (5 to 10 dpf) filaments.

Claims

exact text as granted — not AI-modified

I claim:

1. A process for forming an as-spun filament of a thermotropic liquid crystalline polymer having the following properties:
(i) denier of at least about 50 denier per filament;
(ii) tenacity of at least about 8 grams per denier;
(iii) modulus of at least about 450 grams per denier; and
(iv) elongation of at least about 2 percent;
said process comprising the steps of:
(a) heating a thermotropic liquid crystalline polymer to a temperature of at least about 15° C. above its melting transition to form a fluid stream of said thermotropic polymer;
(b) passing said stream through a heated extrusion chamber, wherein said chamber is disposed with a suitable cylindrical orifice to form the filament of said polymer, and wherein said cylindrical orifice has an aspect ratio of length to diameter (L/D) greater than about 1 and less than about 15; and
(c) winding said filament at a take-up speed of at least about 200 meters per minute and draw-down (DD) ratio of at least about 4; and with the proviso that when L/D is between 0 to 2, the DD is at least 4 so as to form the filament of essentially uniform molecular orientation across its cross-section and having a denier of at least about 50 denier per filament.

2. The process as set forth in claim 1 , wherein said thermotropic liquid crystalline polymer is selected from the group consisting of wholly aromatic polyesters, aromatic-aliphatic polyesters, aromatic polyazomethines, aromatic polyesteramides, aromatic polyamides, and aromatic polyester-carbonates.

3. The process as set forth in claim 1 , wherein said thermotropic liquid crystalline polymer is a wholly aromatic polyester.

4. The process as set forth in claim 3 , wherein said polyester comprises a melt processable wholly aromatic polyester capable of forming an anisotropic melt phase at a temperature below approximately 350° C. consisting essentially of the recurring moieties I and II wherein:
I is
and
II is
wherein said polyester comprises about 10 to about 90 mole percent of moiety I, and about 10 to about 90 mole percent of moiety II.

5. The process as set forth in claim 3 , wherein said polyester comprises a melt processable wholly aromatic polyester capable of forming an anisotropic melt phase at a temperature below approximately 400° C. consisting essentially of the recurring moieties I, II, III, and VII wherein:
I is
II is
III is
and
VII is
wherein said polyester comprises about 40 to about 70 mole percent of moiety I, about 1 to about 20 mole percent of moiety II, and about 14.5 to about 30 mole percent each of moieties III and VII.

6. The process as set forth in claim 1 , wherein said thermotropic liquid crystalline polymer is a wholly aromatic polyesteramide.

7. The process as set forth in claim 6 , wherein said polyesteramide comprises a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 360° C. consisting essentially of the recurring moieties II, I, III and VI wherein:
II is
IIII is
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety II, and about 15 to about 30 mole percent each of moieties I, III and VI.

8. The process as set forth in claim 6 , wherein said polyesteramide comprises a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 380° C. consisting essentially of the recurring moieties I, II, III, VII and VI wherein:
I is
II is
III is
VII is
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety I, about 1 to about 20 mole percent of moiety II, about 14.5 to about 30 mole percent of moiety III, about 7 to about 27.5 mole percent of moiety VII, and about 2.5 to about 7.5 mole percent of moiety VI.

9. The process as set forth in claim 6 , wherein said polyesteramide comprises a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 350° C. consisting essentially of the recurring moieties I, II, III, IV, V, and VI wherein:
I is
II is
III is
IV is
V is
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety I, about 10 to about 20 mole percent of moiety II, about 2.5 to about 20 mole percent of moiety III, about 0 to about 3 mole percent of moiety IV, about 12.5 to about 27.5 mole percent of moiety V and about 2.5 to about 7.5 mole percent of moiety VI.

10. The process as set forth in claim 1 , wherein said thermotropic liquid crystalline polymer is heated to a temperature of from about 20° C. to about 50° C. above its melting transition.

11. The process as set forth in claim 1 , wherein said aspect ratio (L/D) is from about 1 to about 10.

12. The process as set forth in claim 1 , wherein said aspect ratio (L/D) is from about 1 to about 3.

13. The process as set forth in claim 1 , wherein said draw-down ratio is from about 4 to about 20.

14. The process as set forth in claim 1 , wherein said draw-down ratio is from about 4 to about 15.

15. The process as set forth in claim 1 , wherein said filaments are a monofilament.

16. The process as set forth in claim 15 , wherein denier of said filament is from about 100 to about 1000 denier per filament.

17. The process as set forth in claim 15 , wherein denier of said filament is from about 150 to about 500 denier per filament.

18. The process as set forth in claim 15 , wherein denier of said filament is from about 180 to about 300 denier per filament.

19. The product produced by the process of claim 1 .

20. The product produced by the process of claim 4 .

21. The product produced by the process of claim 5 .

22. The product produced by the process of claim 7 .

23. The product produced by the process of claim 8 .

24. The product produced by the process of claim 9 .

25. The product produced by the process of claim 17 .

26. The product produced by the process of claim 18 .

27. A process for forming a heat-treated filament of a thermotropic liquid crystalline polymer having the following properties:
(i) denier of at least about 50 denier per filament;
(ii) tenacity of at least about 20 grams per denier;
(iii) modulus of at least about 600 grams per denier; and
(iv) elongation of at least about 3 percent;
said process comprising the steps of:
(a) heating a thermotropic liquid crystalline polymer to a temperature of about 15° C. to about 50° C. above its melting transition to form a fluid stream of said polymer;
(b) extruding said stream of polymer through a heated cylindrical spinneret having at least one extrusion capillary to form a filament, wherein said capillary has an aspect ratio of length to diameter (L/D) in the range of from about 1 to about 10;
(c) winding said filament at a take-up speed of at least about 200 meters per minute and draw-down ratio of from about 5 to about 40 so as to form a filament of essentially uniform molecular orientation across the cross-section and having a denier in the range of from about 50 to about 1000 denier per filament; and
(d) heat-treating said filament at suitable temperature and pressure conditions for a sufficient period of time, optionally in the presence of an inert atmosphere, to form the heat-treated filament.

28. The process as set forth in claim 27 , wherein said thermotropic liquid crystalline polymer is selected from the group consisting of:
(i) a melt processable wholly aromatic polyester capable of forming an anisotropic melt phase at a temperature below approximately 350° C. consisting essentially of the recurring moieties I and II wherein:
I is
and
II is
wherein said polyester comprises about 10 to about 90 mole percent of moiety I, and about 10 to about 90 mole percent of moiety II;
(ii) a melt processable wholly aromatic polyester capable of forming an anisotropic melt phase at a temperature below approximately 400° C. consisting essentially of the recurring moieties I, II, III, and VII wherein:
I is
II is
III is
and
VII is
wherein said polyester comprises about 40 to about 70 mole percent of moiety I, about 1 to about 20 mole percent of moiety II, and about 14.5 to about 30 mole percent each of moieties III and VII;
(iii) a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 360° C. consisting essentially of the recurring moieties II, I, III and VI wherein:
II is
IIII is
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety II, about 15 to about 30 mole percent each of moieties I, III and VI;
(iv) a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 380° C. consisting essentially of the recurring moieties I, II, III, VII and VI wherein:
I is
II is
III is
VII is
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety I, about 1 to about 20 mole percent of moiety II, about 14.5 to about 30 mole percent of moiety III, about 7 to about 27.5 mole percent of moiety VII, and about 2.5 to about 7.5 mole percent of moiety VI; and
(v) a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 350° C. consisting essentially of the recurring moieties I, II, III, IV, V, and VI wherein:
I is
II is
III is
IV is
V is
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety I, about 10 to about 20 mole percent of moiety II, about 2.5 to about 20 mole percent of moiety III, about 0 to about 3 mole percent of moiety IV, about 12.5 to about 27.5 mole percent of moiety V and about 2.5 to about 7.5 mole percent of moiety VI.

29. The process as set forth in claim 27 , wherein said aspect ratio (L/D) is from about 1 to about 3.

30. The process as set forth in claim 27 , wherein said heat treatment in step (d) is carried out in stages at a final temperature of about 10° C. to about 15° C. below the melting transition of said thermotropic liquid crystalline polymer.

31. The process as set forth in claim 27 , wherein denier of said filament is from about 150 to about 500 denier per filament.

32. The process as set forth in claim 27 , wherein denier of said filament is from about 180 to about 300 denier per filament.

33. The product produced by the process of claim 27 .

34. The product produced by the process of claim 28 .

35. The product produced by the process of claim 29 .

36. The product produced by the process of claim 30 .

37. The product produced by the process of claim 31 .

38. An as-spun filament of a thermotropic liquid crystalline polymer having the following properties:
(a) denier of at least about 50 denier per filament;
(b) tenacity of at least about 8 grams per denier;
(c) modulus of at least about 450 grams per denier; and
(d) elongation of at least about 2 percent.

39. The filament as set forth in claim 38 , wherein said thermotropic liquid crystalline polymer is selected from the group consisting of:
(i) a melt processable wholly aromatic polyester capable of forming an anisotropic melt phase at a temperature below approximately 350° C. consisting essentially of the recurring moieties I and II wherein:
I is
and
II is
wherein said polyester comprises about 10 to about 90 mole percent of moiety I, and about 10 to about 90 mole percent of moiety II;
(ii) a melt processable wholly aromatic polyester capable of forming an anisotropic melt phase at a temperature below approximately 400° C. consisting essentially of the recurring moieties I, II, III, and VII wherein:
I is
II is
III is
and
VII is
wherein said polyester comprises about 40 to about 70 mole percent of moiety I, about 1 to about 20 mole percent of moiety II, and about 14.5 to about 30 mole percent each of moieties III and VII;
(iii) a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 360° C. consisting essentially of the recurring moieties II, I, III and VI wherein:
II is
IIII
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety I, II and about 15 to about 30 mole percent each of moieties II, III and III VI;
(iv) a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 380° C. consisting essentially of the recurring moieties I, II, III, VII and VI wherein:
I is
II is
III is
VII is
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety I, about 1 to about 20 mole percent of moiety II, about 14.5 to about 30 mole percent of moiety III, about 7 to about 27.5 mole percent of moiety VII, and about 2.5 to about 7.5 mole percent of moiety VI; and
(v) a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 350° C. consisting essentially of the recurring moieties I, II, III, IV, V, and VI wherein:
I is
II is
III is
IV is
V is
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety I, about 10 to about 20 mole percent of moiety II, about 2.5 to about 20 mole percent of moiety III, about 0 to about 3 mole percent of moiety IV, about 12.5 to about 27.5 mole percent of moiety V and about 2.5 to about 7.5 mole percent of moiety VI.

40. The filament as set forth in claim 38 , wherein denier of said filament is from about 100 to about 1000 denier per filament.

41. The filament as set forth in claim 38 , wherein denier of said filament is from about 150 to about 500 denier per filament.

42. The filament as set forth in claim 38 , wherein denier of said filament is from about 180 to about 300 denier per filament.

43. A heat-treated filament of a thermotropic liquid crystalline polymer having the following properties:
(a) denier of at least about 50 denier per filament;
(b) tenacity of at least about 20 grams per denier;
(c) modulus of at least about 600 grams per denier; and
(d) elongation of at least about 3 percent.

44. The filament as set forth in claim 43 , wherein said thermotropic liquid crystalline polymer is selected from the group consisting of:
(i) a melt processable wholly aromatic polyester capable of forming an anisotropic melt phase at a temperature below approximately 350° C. consisting essentially of the recurring moieties I and II wherein:
I is
and
II is
wherein said polyester comprises about 10 to about 90 mole percent of moiety I, and about 10 to about 90 mole percent of moiety II;
(ii) a melt processable wholly aromatic polyester capable of forming an anisotropic melt phase at a temperature below approximately 400° C. consisting essentially of the recurring moieties I, II, III, and VII wherein:
I is
II is
III is
and
VI is
wherein said polyester comprises about 40 to about 70 mole percent of moiety I, about 1 to about 20 mole percent of moiety II, and about 14.5 to about 30 mole percent each of moieties III and VII;
(iii) a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 360° C. consisting essentially of the recurring moieties II, I, III and VI wherein:
I is
IIII is
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety II, about 15 to about 30 mole percent each of moieties I, III and VI;
(iv) a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 380° C. consisting essentially of the recurring moieties I, II, III, VII and VI wherein:
I is
II is
III is
VII is
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety I, about 1 to about 20 mole percent of moiety II, about 14.5 to about 30 mole percent of moiety III, about 7 to about 27.5 mole percent of moiety VII, and about 2.5 to about 7.5 mole percent of moiety VI; and
(v) a melt processable wholly aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below approximately 350° C. consisting essentially of the recurring moieties I, II, III, IV, V, and VI wherein:
I is
II is
III is
IV is
V is
and
VI is
wherein said polyesteramide comprises about 40 to about 70 mole percent of moiety I, about 10 to about 20 mole percent of moiety II, about 2.5 to about 20 mole percent of moiety III, about 0 to about 3 mole percent of moiety IV, about 12.5 to about 27.5 mole percent of moiety V and about 2.5 to about 7.5 mole percent of moiety VI.

45. The filament as set forth in claim 43 , wherein denier of said filament is from about 100 to about 1000 denier per filament.

46. The filament as set forth in claim 43 , wherein denier of said filament is from about 150 to about 500 denier per filament.

47. The filament as set forth in claim 43 , wherein denier of said filament is from about 180 to about 300 denier per filament.

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