Polyester fiber for airbag and preparation method thereof

Patent metadata

Field	Value
Publication number	US-9617664-B2
Application number	US-201013516500-A
Country	US
Kind code	B2
Filing date	Dec 17, 2010
Priority date	Dec 18, 2009
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

The present invention relates to a polyester fiber that can be applied to a fabric for airbag, particularly, to a polyester fiber having an elongation of 0.4% or less at the stress of 1.0 g/d, an enlongation of 4.0% or less at the stress of 4.0 g/d, and an enlongation of 7.0% or less at the stress of 7.0 g/d, and an initial modulus of 105 to 130 g/d; a method of preparing the same; and a fabric for airbag prepared therefrom. Since the polyester fiber of the present invention decreases stiffness remarkably and secures superior mechanical properties by having a high strength, high elongation, and high shrinkage, it is possible to provide superior packing property, dimensional stability, and air-tight effect, and to protect passengers safely by minimizing the impact applied to the passengers, when it is used for the fabric for airbag.

First claim

What is claimed is:

1. An airbag comprising an airbag fabric, said airbag fabric comprising a polyester fiber,
wherein said polyester fiber has an elongation of 0.4% or less at a stress of 1.0 g/d, an elongation of 4.0% or less at a stress of 4.0 g/d, and an elongation of 7.0% or less at a stress of 7.0 g/d, an initial modulus of 105 to 130 g/d at room temperature, a tensile tenacity of 8.2 g/d or more, an elongation at break of 14% or more, a dry heat shrinkage of 5.0% to 6.2%,
wherein said polyester fiber is comprised of 60-200 polyester monofilaments, the polyester fiber includes poly(ethylene terephthalate) in the content of 70 mol % or more, a fineness of each of the monofilaments is 4.2 to 7.7 denier, and a total fineness of the polyester fiber is 460 to 600 denier; and
wherein said polyester fiber is produced by a process comprising the steps of:
melt-spinning a polyester polymer having an intrinsic viscosity of 0.85 dl/g or more at 283 to 295° C. to prepare a polyester undrawn fiber;
drawing the polyester undrawn fiber with a total drawing ratio of 5.7 to 6.1; and
heat-setting the drawn fiber at a temperature of 215 to 225° C.

2. The airbag according to claim 1 , wherein an intrinsic viscosity of the polyester fiber is 0.8 dl/g or more.

3. The airbag according to claim 1 , wherein a content of carboxylic end group of the polyester fiber is 50 meq/kg or less.

4. The airbag according to claim 1 , wherein a crystallinity of the polyester fiber is 40% to 55%.

5. The airbag according to claim 1 , wherein a toughness of the polyester fiber is 25×10 −1 g/d or more.

6. The airbag according to claim 1 , wherein the total fineness is 460 to 530 denier.

7. The airbag fiber according to claim 1 , wherein the total fineness of the polyester fiber is 460 to 530 denier.

8. An airbag fabric comprising a polyester fiber, said polyester fiber having an elongation of 0.4% or less at a stress of 1.0 g/d, an elongation of 4.0% or less at a stress of 4.0 g/d, and an elongation of 7.0% or less at a stress of 7.0 g/d, an initial modulus of 105 to 130 g/d at room temperature, a tensile tenacity of 8.2 g/d or more, an elongation at break of 14% or more, a dry heat shrinkage of 5.0% to 6.2%,
wherein said polyester fiber is comprised of 60-200 polyester monofilaments, the polyester fiber includes poly(ethylene terephthalate) in the content of 70 mol % or more, a fineness of each of the monofilaments is 4.2 to 7.7 denier, and a total fineness of the polyester fiber is 460 to 600 denier; and
wherein said polyester fiber is produced by a process comprising the steps of:
melt-spinning a polyester polymer having an intrinsic viscosity of 0.85 dl/g or more at 283 to 295° C. to prepare a polyester undrawn fiber;
drawing the polyester undrawn fiber with a total drawing ratio of 5.7 to 6.1; and
heat-setting the drawn fiber at a temperature of 215 to 225° C.

9. The airbag fabric according to claim 8 , which has a tensile tenacity of 220 kgf/inch or more, said tensile tenacity being measured according to ASTM D 5034 method.

10. The airbag fabric according to claim 8 , which has a tearing strength of 22 kgf or more, said tearing strength being measured according to ASTM D 2261 method.

11. The airbag fabric according to claim 8 , which has a shrinkage rate in the warp direction of 4.0% or less and a shrinkage rate in the weft direction of 4.0% or less, said shrinkage rate being measured according to ASTM D 1776 method.

12. The airbag fabric according to claim 8 , which has a stiffness of 0.2 kgf or more, said stiffness being measured according to ASTM D 4032 method.

13. The airbag fabric according to claim 8 , which has an air permeability of 10.1 cfm or less, said air permeability being measured according to ASTM D 737 method.

14. A method of preparing the polyester fiber according to claim 1 , including the steps of:
melt-spinning a polyester polymer having an intrinsic viscosity of 0.85 dl/g or more at 283 to 295° C. to prepare a polyester undrawn fiber; and
drawing the polyester undrawn fiber to obtain the polyester fiber at a total drawing ratio of 5.7 to 6.1; and
heat-setting the drawn fiber at a temperature of 215 to 225° C.,
wherein the polyester fiber has an elongation of 0.4% or less at a stress of 1.0 g/d, an elongation of 4.0% or less at a stress of 4.0 g/d, and an elongation of 7.0% or less at a stress of 7.0 g/d, an initial modulus of 105 to 130 g/d at room temperature, a tensile tenacity of 8.2 g/d or more, an elongation at break of 14% or more, and a dry heat shrinkage of 5.0% to 6.2%;
wherein the polyester fiber is comprised of 60-200 polyester monofilaments;
wherein the polyester fiber includes poly(ethylene terephthalate) in a content of 70 mol % or more; and
wherein a total fineness of the polyester fiber is 250 to 600 denier.

15. The method according to claim 14 , wherein a difference in the intrinsic viscosity between the polyester polymer and the polyester fiber is 0.5 dl/g or less.

16. The method according to claim 14 , wherein a content of carboxylic end group (CEG) of the polyester polymer is 30 meq/kg or less.

17. The method according to claim 14 , wherein a difference between the CEG content of the polyester polymer and the CEG content of the polyester fiber is 20 meq/kg or less.

18. The method according to claim 14 , wherein the melt-spinning process is carried out with a spinning speed of 300 m/min to 1,000 m/min.

19. The method according to claim 14 , wherein the drawing process is carried out after passing the undrawn fiber through godet rollers with a condition of an oil pick-up unit of 0.2% to 2.0%.

20. The method according to claim 14 , further including a relaxing process after drawing the undrawn fiber, wherein a relaxing ratio is 1% to 7%.

21. The method according to claim 14 , further including a winding process after drawing the undrawn fiber, wherein a winding speed is 2,000 to 4,000 m/min.

Assignees

• Kim Young-Jo
• Kim Ki-Jeong
• Lee Sang-Mok
• Lee Young-Soo
• Kolon Inc

Inventors

• Kim Young-Jo
• Kim Ki-Jeong
• Lee Sang-Mok
• Lee Young-Soo

Classifications

• Y10T428/298

  Physical dimension · CPC title

• D01F6/62

  from polyesters · CPC title

• D03D1/02 Primary

  Inflatable articles · CPC title

• D01D10/02

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

• Y10T442/3008

  Woven fabric has an elastic quality · CPC title