Process for processing polymer mixtures to filaments

• US 5,962,131 A
• Filed: 08/05/1998
• Issued: 10/05/1999
• Est. Priority Date: 08/05/1997
• Status: Expired due to Fees

• Current Assignee: Degussa AG (Rag-Stiftung), ROHM Co., Ltd., Zimmer AG
• Original Assignee: Degussa AG (Rag-Stiftung)
• Inventors: Kempf, Peter, Schwind, Helmut, Klein, Alexander, Thiele, Ulrich, Wandel, Dietmar, Janas, Wolfgang, Cziollek, Joachim, Schumann, Heinz-Dieter, Dorn, Klaus
• Primary Examiner(s): Acquah, Samuel A.
• Application Number:
  US09/129,624
• Time in Patent Office: 426 Days
• Field of Search: 525/7.1, 525/8, 525/10, 525/165, 525/242, 525/244, 525/329.7, 525/330.3, 525/333.3, 525/437, 525/445, 264/176.1, 264/177.13, 264/177.17, 264/210.8, 428/221, 428/364
• US Class Current: 428/364
• CPC Class Codes: C08F 220/14 Methyl esters , e.g. methyl (meth)acrylate
• CPC Class Codes: C08F 222/04 Anhydrides, e.g. cyclic anhydrides
• CPC Class Codes: C08F 222/402 Alkyl substituted imides
• CPC Class Codes: D01F 6/92 of polyesters
• CPC Class Codes: Y10T 428/249921 Web or sheet containing structurally defined element or component
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber

Abstract

Process for the production of preoriented filaments from polyester-based polymer mixtures by spinning the polymer mixtures with a draw-off speed v of at least 2500 m/min, a second amorphous, thermoplastically processable copolymer having a glass transition temperature of more than 100° C. being added to the polyester, wherein the ratio of the melt viscosity of the copolymer to the melt viscosity of the polyester is 1:1 to 10:1, in that the amount of copolymer added to the polyester is at least 0.05 wt. %, in that the maximum amount M of the copolymer added to the polyester depends on the draw-off speed v, and in that ##EQU1##

Claims

1. A process for production of preoriented filaments from polyester-based polymer mixtures prepared from a melt, comprising:

adding an amorphous, thermoplastically processable copolymer having a glass transition temperature of more than 100°

C., by spinning molten polymer mixtures with a draw-off speed v of at least 2,500 m/min, wherein;

a ratio of melt viscosity of the copolymer to melt viscosity of the polyester is 1;

1 to 10;

1, in that the amount of copolymer added to the polyester corresponds to at least 0.05 wt. % and not more than an amount M, where M is given by the formula ##EQU13##

2. The process according to claim 1, wherein:

the ratio of the melt viscosity of the copolymer to the melt viscosity of the polyester is 1.4;

1 to 8;

1.

3. The process according to claim 1, wherein:

the ratio of the melt viscosity of the copolymer to the melt viscosity of the polyester is 1.7;

1 to 6.5;

1.

4. The process according to claim 1, wherein:

the copolymer comprises the following monomer units;

A=acrylic acid, methacrylic acid or CH₂ ═

CR--COOR'"'"', wherein R is an H atom or a CH₃ group and R'"'"' is a C_1-15 -alkyl radical or a C_5-12 -cycloalkyl radical or a C_6-14 -aryl radical,

B=styrene or C_1-3 -alkyl-substituted styrenes,

wherein the copolymer comprises 60 to 98 wt. % A and 2 to 40 wt. % B (total=100 wt. %).

5. The process according to claim 4, wherein:

the copolymer comprises 83 to 98 wt. % A and 2 to 17 wt. % B (total=100 wt. %).

6. The process according to claim 4, wherein:

the copolymer comprises 90 to 98 wt. % A and 2 to 10 wt. % B (total=100 wt. %).

7. The process according to claim 1, wherein:

the copolymer comprises the following monomer units;

C=styrene or C_1-3 -alkyl-substituted styrenes,

D=one or more monomers of the formula I, II or III ##STR3## wherein R₁, R₂ and R₃ are each an H atom or a C_1-15 -alkyl radical or a C_5-12 -cycloalkyl radical or a C_6-14 -aryl radical,

and wherein the copolymer comprises 15 to 95 wt. % C and 5 to 85 wt. % D, the total of C and D together being 100%.

8. The process according to claim 7, wherein:

the copolymer comprises 50 to 90 wt. % C and 10 to 50 wt. % D, the total of C and D together being 100%.

9. The process according to claim 7, wherein:

the copolymer comprises 70 to 85 wt. % C and 30 to 15 wt. % D, the total of C and D together giving 100%.

10. The process according to claim 1, wherein:

the copolymer comprises the following monomer units;

E=acrylic acid, methacrylic acid or CH₂ ═

CR--COOR'"'"', wherein R is an H atom or a CH₃ group and R'"'"' is a C_1-15 -alkyl radical or a C_5-12 -cycloalkyl radical or a C_6-14 -aryl radical,

F=styrene or C_1-3 -alkyl-substituted styrenes,

G=one or more monomers of the formula I, II or III ##STR4## wherein R₁, R₂ and R₃ are each an H atom or a C_1-15 -alkyl radical or a C_5-12 -cycloalkyl radical or a C_6-14 -aryl radical,

H=one or more ethylenically unsaturated monomers, which is copolymerized with E and/or with F and/or with G, selected from the group consisting of α

-methylstyrene, vinyl acetate, acrylic acid esters, methacrylic acid esters which differ from E, vinyl chloride, vinylidene chloride, halogen-substituted styrenes, vinyl ethers, isopropenyl ethers and dienes,

wherein the copolymer comprises 30 to 99 wt. % E, 0 to 50 wt. % F, >

0 to 50 wt. % G and 0 to 50 wt. % H, the total of E, F, G and H together being 100%.

11. The process according to claim 10, wherein:

the copolymer comprises 45 to 97 wt. % E, 0 to 30 wt. % F, 3 to 40 wt. % G and 0 to 30 wt. % H, the total of E, F, G and H together being 100%.

12. The process according to claim 10, wherein:

the copolymer comprises 60 to 94 wt. % E, 0 to 20 wt. % F, 6 to 30 wt. % G and 0 to 20 wt. % H, the total of E, F, G and H together being 100%.

13. The process according to claim 1, wherein:

the copolymer comprises additives in an amount, in each case, of <

1 wt. %, for improving the polymer properties.

14. The process according to claim 1, wherein:

the polymer mixture is prepared, after melting of the polyester and copolymer, in a static mixer, a diameter of which is chosen such that shear rate is between 16 and 128 s^-1 and a product of the shear rate and an 0.8th power of residence time in seconds is greater than 250.

15. The process according to claim 1, wherein:

the mixture is subjected to shear treatment during mixing such that an average particle size of the copolymer immediately after discharge from a spinneret is not more than 400 nm, that less than 1% of copolymer particles contained in the mixture have a particle size of >

1 μ

m, and that the length/diameter ratio of the copolymer particles is >

2, the copolymer particles being present in a polymer matrix in the filaments in a form of fibrils after spinning draft, a length/diameter ratio of the fibrils being >

50.

16. The process according to claim 1, wherein:

the polyester is a thermoplastically processable polyester comprising polyethylene terephthalate, polyethylene naphthalate, polypropylene terephthalate or polybutylene terephthalate, wherein the polyester optionally comprises at least one member selected from the group consisting of up to 15 mol % of a comonomer and up to 0.5 wt. % of a polyfunctional branching component.

17. The process according to claim 1, wherein:

the filaments are initially wound up after spinning and are then subjected to stretch texturizing, a stretching ratio being between 1;

1.35 and 1;

2.20.

18. The process according to claim 17, wherein:

texturized filaments with a capillary titer of more than 2 dtex are produced at a processing speed of at least 750 m/min and texturized filaments with a capillary titer of less than 2 dtex are produced at a processing speed of at least 400 m/min.

19. Preoriented filaments produced according to the process of claim 1, wherein:

the filaments have an elongation at break of 85 to 180%, a tear strength of at least 17 cN/tex, a shrinkage at the boil of 32 to 69%, a birefringence of 0.030 to 0.075 and a crystallinity of less than 20%.

20. Preoriented filaments according to claim 19, having an elongation at break of 109 to 146%, a tear strength of at least 22 cN/tex and a normal Uster of <

0.7%.

21. Texturized filaments produced from the preoriented filaments according to claim 19.