Solution containing cellulose dissolved in n-methylmorpholine-n-oxide and high tenacity lyocell multifilament using the same

• US 20050154093A1
• Filed: 10/24/2003
• Published: 07/14/2005
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: Hyosung Advanced Materials Corporation (Hyosung Corporation)
• Original Assignee: Hyosung Corporation
• Inventors: Kim, Sung-Ryong, Lee, Tae-Jung, Kwon, Ik-Hyeon, Choi, Jae-Shik, Choi, Soo-Myung, Wang, Young-Soo, Han, Seok-Jong, Kim, Myung-Woo
• Granted Patent: US 7,214,727 B2
• Time in Patent Office: Days
• US Class Current: 524/35
• CPC Class Codes: B60C 9/0042 Reinforcements made of synthetic materials
• CPC Class Codes: C08B 1/003 Preparation of cellulose solutions, i.e. dopes, with different possible solvents, e.g. ionic liquids solutions used in the manufacture of monocomponent artificial filaments or cellulose or derivatives thereof D01F2/02
• CPC Class Codes: D01F 2/00 Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
• CPC Class Codes: D02G 3/48 Tyre cords tyre reinforcements B60C9/00; metal cords for reinforcing rubber or plastic articles D07B1/0606
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber

Abstract

This invention relates to a method of preparing cellulose solution which is homogeneous at relatively low temperature, in which a small amount of cellulose powder or polyvinylalcohol is dissolved in the liquid-state, concentrated N-methylmorpholine-N-oxide (hereinafter, referred to as ‘NMMO’) so as to lower the solidifying temperature of NMMO, and then, the resulting solution and cellulose powder are fed into an extruder so as to be mixed, swollen and melted in the extruder.

Claims

1. A method of preparing cellulose solution, comprising the steps of:

(A) dissolving 0.01 to 3% by weight of cellulose powder in the liquid-state, concentrated N-methylmorpholine-N-oxide (NMMO) solvent to provide cellulose-containing NMMO solution; and

(B) feeding the cellulose-containing NMMO solution and the cellulose powder into an extruder having a screw to be subjected to dispersing, mixing, shearing, kneading, melting and measuring processes in the extruder so as to produce cellulose solution that is swollen and homogenized.

2. The method of claim 1, the cellulose powder used in the step (A) has a particle size of less than 5,000 micrometer.

3. The method of claim 1, the NMMO solution in the step (A) contains 10 to 18% by weight of water with respect to the total weight of the NMMO solution.

4. The method of claim 1, the cellulose solution is produced continuously without attaching an extra water-vaporizer to the extruder in the step (B).

5. The method of claim 1, the cellulose powder used in the step (B) has a particle size of less than 5,000 micrometer.

6. The method of claim 1, the cellulose solution obtained by mixing, swelling and dissolving in the extruder in the step (B) contains 3 to 20% by weight of the cellulose with respect to the total weight of the cellulose solution.

7. The method of claim 1, the cellulose-containing NMMO solution is fed into the extruder while being maintained at 40 to 90°

C. in the step (B).

8. The method of claim 1, the extruder used in the step (B) is twin-axis type extruder, and has 3 to 16 barrels or 12 to 64 L/D (length/diameter) of the screw.

9. The method of claim 8, the twin-axis type extruder is operated with it maintained at the temperature ranging from 30 to 110°

C.

10. The method of claim 1, the cellulose powder mixed with other polymer(s) can be used in the steps (A) or (B).

11. A cellulose solution obtained according to the method of claim 1, wherein the cellulose solution has 20 or less of non-dissolved particles in the area of 5×

5 mm² of a slide glass which contains the sample through a polarization microscope.

12. A method of preparing cellulose solution, comprising the steps of:

(A) dissolving 0.1 to 10% by weight of polyvinylalcohol in the liquid-state, concentrated N-methylmorpholine-N-oxide (NMMO) solvent to provide polyvinylalcohol-containing NMMO solution; and

(B) feeding the polyvinylalcohol-containing NMMO solution and cellulose powder into an extruder, and then mixing, swelling and dissolving in the extruder so as to produce cellulose solution.

13. The method of claim 12, the polyvinylalcohol used in the step (A) has a degree of polymerization in the range of 500 to 6,000 and a saponification value in the range of 80 to 99.9%.

14. The method of claim 12, the NMMO solution in the step (A) contains 10 to 18% by weight of water with respect to the total weight of the NMMO solution.

15. The method of claim 12, the cellulose solution is produced continuously without attaching an extra water-vaporizer to the extruder in the step (B).

16. The method of claim 12, the cellulose powder used in the step (B) has a particle size of less than 5,000 micrometer.

17. The method of claim 12, the cellulose solution obtained by mixing, swelling and dissolving in the extruder in the step (B) contain 3 to 20% by weight of the cellulose with respect to the total weight of the cellulose solution.

18. The method of claim 12, the extruder used in the step (B) is twin-axis type extruder, and has 3 to 16 barrels or 12 to 64 L/D (length/diameter) of the screw.

19. The method of claim 18, the twin-axis type extruder is operated with it maintained at the temperature ranging from 30 to 110°

C.

20. The method of claim 12, the cellulose powder mixed with other polymer(s) can be used in the steps (A) or (B).

21. A cellulose solution obtained according to the method of claim 12, wherein the cellulose solution has 20 or less of non-dissolved particles in the area of 5×

5 mm² of a slide glass which contains the sample through a polarization microscope.

22. A method of preparing cellulose fiber, comprising the steps of:

(A) dissolving 0.01 to 3% by weight of cellulose powder in the liquid-state, concentrated N-methylmorpholine-N-oxide (NMMO) solvent to provide cellulose-containing NMMO solution;

(B) feeding the cellulose-containing NMMO solution and the cellulose powder into an extruder having a screw to be subjected to dispersing, mixing, shearing, kneading, melting and measuring processes in the extruder so as to produce cellulose solution that is swollen and homogenized;

(C) spinning the cellulose solution through nozzle of a spinner, solidifying it through an aeration layer and solidifying bath to obtain multi-filament; and

(D) washing, drying, oil-treating and winding the obtained multi-filament.

23. A cellulose cellulose fiber obtained according to the method of claim 22, wherein the fiber has a mechanical strength at a dry state of 5 to 10 g/d, elasticity at a dry state of 200 to 400 g/d, a mechanical strength at a wet state of 4 to 10 g/d and index of fibrillation of 5 or less.

24. A tire cord obtained by using the cellulose fiber produced according to claim 23.

25. A method of preparing cellulose fiber, comprising the steps of:

(A) dissolving 0.01 to 3% by weight of polyvinylalcohol in the liquid-state, concentrated N-methylmorpholine-N-oxide (NMMO) solvent to provide polyvinylalcohol-containing NMMO solution;

(B) feeding the polyvinylalcohol-containing NMMO solution and cellulose powder into an extruder, and then mixing, swelling and dissolving in the extruder so as to produce cellulose solution;

(C) spinning the cellulose solution through nozzle of a spinner, solidifying it through an aeration layer and solidifying bath to obtain multi-filament; and

(D) washing, drying, oil-treating and winding the obtained multi-filament.

26. A cellulose cellulose fiber obtained according to the method of claim 25, wherein the fiber has a mechanical strength at a dry state of 5 to 10 g/d, elasticity at a dry state of 200 to 400 g/d, a mechanical strength at a wet state of 4 to 10 g/d and index of fibrillation of 5 or less.

27. A tire cord obtained by using the cellulose fiber produced according to claim 26.