Polyester yarn and production method thereof

Patent metadata

Field	Value
Publication number	US-9797071-B2
Application number	US-201113994503-A
Country	US
Kind code	B2
Filing date	Dec 14, 2011
Priority date	Dec 15, 2010
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

Disclosed is a polyester yarn that can be used in a fabric for an airbag. In particular, a polyester yarn having a diethylene glycol content of 1.1 to 2.5 wt % and initial modulus of 100 g/d or less, a production method thereof, and a fabric for an airbag produced therefrom are disclosed. The polyester yarn has excellent moisture and heat resistance and light resistance, and maintained excellent mechanical properties after long-term aging under high temperature and high humidity conditions. Therefore, when applied to a fabric for an airbag, the polyester yarn provides excellent packing property, shape stability, and gas barrier effect, and the impact applied to a passenger is minimized, thereby safely protecting the passenger at the same time.

First claim

What is claimed:

1. A drawn polyester yarn having
a diethylene glycol content of 1.1 to 2.65 wt %,
an initial modulus of 75-100 g/d, and
an intrinsic viscosity of 0.9-1.2 dl/g,
wherein the polyester yarn is produced by a process comprising:
providing a polyester polymer chip having an intrinsic viscosity of 0.5-0.8 dl/g,
subjecting the polyester polymer chip to a solid state polymerization to prepare a solid state polymerized polyester chip having an intrinsic viscosity of 0.90-2.0 dl/g,
melt-spinning the solid state polymerized polyester chip to produce an undrawn polyester yarn,
drawing the polyester yarn at a ratio of 5.0-5.8 at a winding speed of 2,000-4,000 m/min to obtain the drawn polyester yarn.

2. The drawn polyester yarn according to claim 1 , wherein drawn the polyester yarn has a carboxyl end group content of 40 meq/kg or less.

3. The drawn polyester yarn according to claim 1 , wherein the drawn polyester yarn has crystallinity of 40% to 55%.

4. The drawn polyester yarn according to claim 1 , wherein the drawn polyester yarn has a tensile strength of 7.5-10.0 g/d and a breaking elongation of 13-35%.

5. The drawn polyester yarn according to claim 1 , wherein the drawn polyester yarn has a dry contraction ratio of 4-12% and toughness of 30×10 −1 −46×10 −1 g/d.

6. The drawn polyester yarn according to claim 1 , wherein an elongation of the drawn polyester yarn is 0.5-1.5% at a stress of 1.0 g/d, 4.3-20% at a stress of 4.0 g/d, and 7.5-25% at a stress of 7.0 g/d, at room temperature.

7. The drawn polyester yarn according to claim 1 , wherein the drawn yarn has a single yarn fineness of 0.5 to 20 denier.

8. The drawn polyester yarn according to claim 1 , wherein the drawn yarn has a total fineness of 200 to 1,000 denier.

9. The drawn polyester yarn according to claim 1 , wherein the drawn yarn has the number of filaments of 50 to 240.

10. A method for producing the drawn polyester yarn according to claim 1 , comprising the steps of:
providing a polyester polymer chip having an intrinsic viscosity of 0.5-0.8 dl/g,
subjecting the polyester polymer chip to a solid state polymerization to prepare a solid state polymerized polyester chip having an intrinsic viscosity of 0.90-2.0 dl/g,
melt-spinning the solid state polymerized polyester polymer chip at 270 to 310° C. to produce an undrawn polyester yarn, and
drawing the undrawn polyester yarn at a ratio of 5.0-5.8 at a winding speed of 2,000-4,000 m/min to obtain a drawn polyester yarn,
wherein the drawn polyester yarn has a diethylene glycol content of 1.1 to 2.65 wt %, an initial modulus of 75-100 g/d, and an intrinsic viscosity of 0.9-1.2 dl/g.

11. The method according to claim 10 , wherein the polyester polymer includes 70 mol % or more of poly(ethylene terephthalate).

12. The method according to claim 10 , wherein the solid state polymerized polyester polymer chip has an intrinsic viscosity of 1.3 to 1.41 dl/g, and a difference of the intrinsic viscosity between the solid state polymerized polyester polymer chip and the yarn is 0.5 dl/g or less.

13. The method according to claim 10 , wherein the polyester polymer has a carboxyl end group content of 30 meq/kg or less.

14. The method according to claim 10 , wherein the difference in the carboxyl end group content between the polyester polymer and the yarn is 20 meq/kg or less.

15. The method according to claim 10 , wherein the drawing process is carried out after passing the undrawn polyester yarn through a godet roller with an oil pickup amount of 0.2% to 2.0%.

16. The method according to claim 10 , further comprising the step of performing a heat fixation process at a temperature of 170 to 250° C. after the step of drawing the undrawn yarn.

17. The polyester yarn according to claim 10 , further comprising the step of performing a relaxation process at a relaxation ratio of 1% to 10% after the step of drawing the undrawn yarn.

18. The method according to claim 10 , further comprising the step of performing a winding process at a winding speed of 2,000 to 4,000 m/min after the step of drawing the undrawn yarn.

19. A polyester fabric for an airbag, comprising the polyester yarn according to claim 1 .

20. The polyester fabric for an airbag according to claim 19 , wherein tear strength of the fabric measured according to the ASTM D 2261 method is 20 kgf or more.

21. The polyester fabric for an airbag according to claim 19 , wherein air permeability of the fabric measured according to the ASTM D 737 method is 10.0 cfm or less.

22. The polyester fabric for an airbag according to claim 19 , wherein stiffness of the fabric measured according to the ASTM D 4032 is 1.0 kgf or less.

23. The polyester fabric for an airbag according to claim 19 , wherein the fabric has a strength retention of 90% or more after aging at 85° C. for 3.000 hours.

24. A drawn polyester yarn having
a diethylene glycol content of 1.1 to 2.65 wt %,
an initial modulus of 75-100 g/d, and
an intrinsic viscosity of 1.01-1.2 dl/g,
wherein the polyester yarn is produced by a process comprising:
melt-spinning a polyester chip having an intrinsic viscosity of 1.3-2.0 dl/g to produce an undrawn polyester yarn,
drawing the polyester yarn at a ratio of 5.0-5.8 at a winding speed of 2,000-4,000 m/min to obtain the drawn polyester yarn.

Assignees

• Kim Young-Jo
• Lee Sang-Mok
• Lee Young-Soo
• Kim Gi-Woong
• Kolon Inc

Inventors

• Kim Young-Jo
• Lee Sang-Mok
• Lee Young-Soo
• Kim Gi-Woong

Classifications

• D01D5/16

  using rollers, or like mechanical devices, e.g. snubbing pins · CPC title

• D02J1/22

  Stretching or tensioning, shrinking or relaxing, e.g. by use of overfeed and underfeed apparatus, or preventing stretch (stretch spinning D01D5/12) · CPC title

• D03D1/02

  Inflatable articles · CPC title

• D01F6/62

  from polyesters · CPC title

• D10B2331/04

  polyesters, e.g. polyethylene terephthalate [PET] · CPC title