KR950000732B1 - Polyester fiber - Google Patents

Abstract

The amorphous polyester fiber is produced by (a) spinning a modified polyester resin of 0.7 intrinsic viscosity obtd. by copolymerizing with a copolymer of at least 100 molecular weight and a polyethylene terephthalate at 285 deg.C spinning temp. and 1500 m/min spinning speed to obtain an undrawn yarn, and (b) drawing the undrawn yarn at 135 deg.C heat-fixing temp. and 2.782-3.192 draw ratio. The copolymer is pref. isophthalic acid, sebacic acid, adipic acid and/or naphthalene carboxylic acid. The amorphous polyester fiber has at most 50 initial modulus and 10-20 crystallinity, has a good softness and flexibility.

Description

Polyester fiber

1 is a wide-angle X-ray graph of a conventional polyester fiber.

2 is a wide-angle X-ray graph of the polyester fiber of the present invention.

The present invention relates to an amorphous polyester fiber having a soft and flexible feeling, even if the alkali reduction process is omitted in post processing.

The conventional polyethylene terephthalate fiber has a hard component in its molecular chain and has a crystal structure, and therefore, it exhibits a hash and hard feeling on the fabric.

Therefore, the conventional polyethylene terephthalate fiber emulsifies the physical properties in the post-processing process after weaving, that is, in the refined shrinkage-preset-alkali weight loss-dyeing-final set process, especially in the alkali weight loss process, to obtain a soft and flexible fabric suitable for clothing. .

Alkaline weight loss process cost about 20-25% of the total post-processing cost and caused the price increase due to installation cost of alkali weight loss equipment. At the same time, waste solution of sodium hydroxide used in alkali weight loss process It caused environmental pollution.

In addition, products in which polyethylene terephthalate fibers are mixed with other natural fibers (cotton, wool, etc.) have been limited in their application to mixed products due to the severe weakening of natural fibers due to alkali reduction treatment.

In Japanese Patent Laid-Open Nos. 53-147814 and 55-128013, copolymerization is carried out by adding a third copolymerization component to polyester to provide softness, softness, and high shrinkage, and to facilitate alkali weight loss processing. However, polyester fibers which have a soft and flexible feeling without reducing alkali as described in the present invention have not been developed.

Hereinafter, the present invention will be described in detail.

The present invention is a polyester fiber comprising a copolymer having a molecular weight of 100 or more and at least 85 mol% of a molecular chain is spun and stretched a polyester copolymer of polyethylene terephthalate, which satisfies the following conditions.

next

Y.M (g / d) ≤ 50

10 ≤ Xc (%) ≤ 20

Here, Y, M: Initial modulus of elasticity within 1% of the intensity-elongation curve obtained using Instron.

Xc is a crystallization degree obtained by the following formula using a density value obtained using a density gradient tube.

Here, ρ _α : density value of the measured sample (g / cm ³ )

ρc: Density value of complete determination (1.457 g / cm ³ )

ρa: Density value of completely amorphous (1.235g / cm ³ )

The present invention is described in more detail as follows.

In order to produce a weightless and soft persimmon polyester fiber, it is necessary to control crystallization and initial modulus.

Control of these properties requires manufacturing process conditions with appropriate molecular design. First, among the most effective molecular design methods for controlling crystallization, polyethylene terephthalate is the main component, and isophthalic acid, sebacic acid, adipic acid, and difunctional acid systems of naphthalenedicarboxylic acid are used alone or in combination. There is a method using a copolymerized polyester resin.

Therefore, the method for producing a weightless polyester fiber of the present invention comprises a copolymer containing polyethylene terephthalate of 85% or more as a main component, and a tertiary acid copolymer having a molecular weight of 100 or more that can replace terephthalic acid by a third component The introduced modified polyester resin is spun at a spinning speed of 1000 m / min or more.

At this time, in order to extremely control the orientation crystallization during spinning, the radiation tension at the time of solidification is minimized so as not to form fibrillation.

The non-drawn yarn thus prepared was drawn at a heat treatment temperature of 130 ° C. or higher and a draw ratio of 3.5 times or less.

2 is a wide-angle X-ray graph of the amorphous polyester stretched yarn thus prepared, and FIG. 1 is a wide-angle X-ray graph of the normal polyethylene terephthalate-based stretched yarn.

In the case of amorphous polyester, the degree of crystallinity is remarkably reduced, and the separation between the respective crystal planes is not clear, and thus the content of the intermediate phase is large.

In the present invention, an initial elastic modulus of 50 g / d or less and a crystallinity of 10 to 20% may be used to obtain the polyester fiber of the lossless soft touch of the present invention.

In general, when the initial modulus and crystallinity are out of the conditions of the present invention, the molecules become hard to obtain a polyester fiber of a weightless soft touch.

In addition, when the stretching ratio exceeds 3.5 times during stretching, crystals and orientations increase, and thus soft touch products cannot be manufactured.

The reason why the copolymer having a molecular weight of 100 or more is used as a bifunctional acid system such as isophthalic acid is because crystallinity is easier to control than polyester copolymerized as an alcohol group.

When the addition of such a copolymer exceeds 15 mol%, the crystallinity and viscosity are lowered, resulting in poor sandability.

[Examples 1 and 2]

After producing a modified polyester resin having a polyethylene terephthalate as a main component and copolymerizing adipic acid as 10 mol% or more as a third component at a spinning temperature of 285 ° C. and a spinning speed of 1500 m / min, after spinning with a modified viscosity of 0.7 The shrine is opened at a fixed temperature of 135 ° C, a draw ratio of 2.782 and 3.192 times to finally prepare a stretched yarn of 75 denier 36 filaments.

Comparative Example 1

After producing a modified polyester resin having a polyethylene terephthalate as a main component and copolymerizing adipic acid as 10 mol% or more as a third component at a spinning temperature of 285 ° C. and a spinning speed of 1500 m / min, after spinning with a modified viscosity of 0.7 The shrine was opened at a heat setting temperature of 135 DEG C and a draw ratio of 4.193 times to finally prepare a stretched yarn of 75 denier 36 filaments.

Example 2

After spinning a polyethylene terephthalate-based polyester resin having an intrinsic viscosity of 0.7 at a spinning temperature of 285 ° C. and a spinning speed of 1500 m / min, the prepared undrawn yarn was opened and stretched at a fixed temperature of 135 ° C. and a draw ratio of 3.192 times. A stretched yarn of filaments was prepared.

The results of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1.

TABLE 1

[Examples 3 and 4 Comparative Example 3]

Example 1, 2 Using the stretched yarn of 75 denier 36 filament of Comparative Example 2, it was produced at a warp density of 40ol / cm, weft density of 40ol / cm.

The dough thus woven was heat-treated at 100 ° C. for 15 minutes in a continuous refiner, and preliminary set was performed under dry heat at 180 ° C. without undergoing an alkali reduction step. Subsequently, the pre-set paper was dyed by a general method of dyeing polyester fibers, and then the final set was performed in dry heat at 180 ° C.

The physical properties were measured and shown in Table 2.

[Comparative Example 4]

Using the drawn yarn of 75 denier 36 filaments of Comparative Example 2, weaving was performed at a warp density of 40ol / cm, weft density of 40ol / cm.

The woven paper was heat-treated at 100 ° C. for 15 minutes in a continuous refiner, and then reduced to 23% to 25% at 40 ° C./l caustic soda solution reducing tank at 95 ° C. for 75 minutes under dry heat of 180 ° C. Preset was made.

Again, this pre-set paper was dyed by a general polyester fiber dyeing method, and the final set was performed in dry heat at 180 ° C.

The physical properties are shown in Table 2.

TABLE 2

However, the feeling of touch (Total Hand Valus: THV); It is the average of the values measured by the KS method and determined by KN-301-Summer.

Claims (2)

A polyester fiber comprising a copolymer having a molecular weight of 100 or more, wherein 85 mol% or more of the molecular chain is polyethylene terephthalate, and satisfying the following conditions. next V) Y, M (g / d) ≤ 50 Ii) 10 ≦ Xc (%) ≦ 20 Where Y and M are initial modulus and Xc is crystallinity. The polyester fiber according to claim 1, wherein the copolymer having a molecular weight of 100 or more is obtained by copolymerizing an isophthalic acid type, sebacic acid type, adipic acid type, and a difunctional acid type of a naphthalenedicarboxylic acid type alone or in combination.