JPH1060740A - Polyester-based self-extensible splittable conjugated fiber and combined filament yarn containing the same and fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fabric rich in reposeful luster and bulkiness comprising combined filament yarns each made up of heat-shrinkable fibers and polyester-based self- extendible splittable conjugated fibers each made up of readily alkali-soluble sea component and sparingly alkali-soluble island component with self-extendibility difference therebetween. SOLUTION: First, a self-extensible splittable conjugate fiber <=0.3 denier in average fineness is formed, which is made up of sea component, i.e., a readily alkali-soluble polyester copolymerized with polyethylene glycol and 5-sodium sulfoisphthalate and island component, i.e., a sparingly alkali-soluble polyester such as polyethylene terephthalate with a self-extendibility difference of >=5% therebetween and produced by asymmetrically arranging the above two kinds of component as illustrated followed by conducting a high-speed conjugate spinning to yield a highly oriented undrawn yarn which is then heat-treated under shrinkage. Subsequently, 20-80wt.% of these conjugate fibers and 80-20wt.% of heat-shrinkable fibers are subjected to interlacing treatment into a combined filament yarn. The other objective fabric is obtained by using the above combined filament yarns so as to account for >=30wt.% of the whole fabric.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyester-based fiber which has irregular and strong crimps and has an average fineness of 0.3 denier or less by splitting after exhibiting self-extensibility and crimp by heat treatment. The present invention relates to a self-extensible splittable conjugate fiber, and a mixed fiber and a fabric containing the conjugate fiber.

[0002]

2. Description of the Related Art Polyester-based splittable conjugate fibers are well known in the art as disclosed in, for example, JP-A-62-57981 and JP-A-4-209825. According to these, a basic method for producing a polyester-based splittable conjugate fiber is one in which an alkali-soluble polymer and a sparingly-soluble polymer are arranged in a sea-island shape and melt-spun. By weaving using the polyester-based splittable conjugate fiber obtained in this way, and then splitting the conjugate fiber by alkali treatment, a soft feeling and drape property can be imparted to the cloth.

However, ultrafine fibers can be obtained by treating the conventional polyester-based splittable conjugate fibers with alkali. However, since these ultrafine fibers are heat-shrinkable, the conventional polyester-based splittable conjugate fibers cannot be used. Although it has a soft feel and drape, it does not have a good swelling with high aeration and the natural elasticity of wool cannot be obtained due to the heat shrinkage of the ultrafine fibers. .

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and the average fineness having irregular and strong crimps can be reduced by dividing after developing self-extensibility and crimp by heat treatment.
Polyester-based self-extensible splittable conjugate fiber that is an ultrafine fiber of 0.3 denier or less, mixed yarn containing this conjugate fiber, and gloss that has a calm surface after heat treatment and splitting into ultrafine fibers using the mixed yarn. It is an object of the present invention to provide a fabric which is rich in lightness, has a stable swelling and fluffiness, has excellent drapability, and exhibits a wool-like soft feeling. .

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention has the following configuration. (1) A splittable conjugate fiber in which a sea component composed of an alkali-soluble polester and an island component composed of an alkali-poorly-soluble polyester having an average single-filament fineness of 0.3 denier or less are arranged asymmetrically in a cross section of the fiber. The polyester-based self-extensible splittable conjugate fiber, wherein the self-elongation rate differs between the polyester component of the sea component and the polyester component of the island component by 5% or more. (2) A mixed fiber comprising 20 to 80% by weight of the polyester-based self-extensible splittable conjugate fiber according to (1) and 80 to 20% by weight of a heat-shrinkable fiber. (3) A fabric containing the mixed fiber according to (2), wherein the proportion of the mixed fiber in the fabric is 30% by weight or more, and the polyester-based self-extensibility according to (1) in the fabric. A fabric in which the proportion of splittable conjugate fibers is 20 to 80% by weight. In the present invention, the self-elongation rate is determined by the following method. After applying a tension of 0.05 g / d to a sample of about 30 cm and measuring the sample length (I ₀ ), leave the sample at a temperature of 160 ° C. for 30 minutes without applying tension. Next, a sample length (I ₁ ) is measured by applying a tension of 0.05 g / d to the sample, and is obtained by the following equation. Self-elongation rate (%) = [(I ₁ −I ₀ ) / I ₀ ] × 100 The self-elongation rate of each of the sea component and the island component is calculated by dividing the self-elongation ratio using only the sea component and the island component only. Yarn spinning is performed under the same conditions as for the composite fiber, and the measurement is performed using a sample that has been subjected to relaxation heat treatment.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

First, the polyester-based self-extensible splittable conjugate fiber of the present invention (hereinafter, referred to as a conjugate fiber) is composed of a polyester component having a solubility in a solvent and a self-extensibility that is extended by heat treatment of 5% or more. , Latent crimping ability, heat-treated to develop self-extensibility and crimp, and then treated with a solvent, the alkali-soluble polymer with weak self-extensibility elutes and self-extends It is divided into a group of ultrafine fibers having an irregular and strong crimp of 0.3 denier or less, which is an alkali hardly soluble, which strongly expresses the property.

[0008] The conjugate fiber of the present invention must be composed of a polyester component having a solubility in alkali and a self-elongation rate of elongation by heat treatment differing by 5% or more.
Each polyester component is preferably polyethylene terephthalate (PET) and copolymerized PET mainly composed of ethylene terephthalate repeating units. Examples of the copolymerization component include dicarboxylic acids such as isophthalic acid, 5-sodium isophthalic acid, naphthalenedicarboxylic acid, adipic acid, and sebacic acid; and diols such as propylene glycol, tetramethylene glycol, diethylene glycol, polyethylene glycol, and cyclohexane dimethanol. Lactic acid, glycolic acid, hydroxybenzoic acid and the like. Further, as the polyester component, it is also possible to use a homogeneous blend of different kinds of polyesters.

[0009] The conjugate fiber of the present invention is composed of at least two kinds of polyester components, each of which is composed of the above-mentioned P component.
Polyesters with different compositions from ET, copolymerized PET, blends, etc. (whether the degree of polymerization is different, the raw materials are different,
Alternatively, when the raw materials are the same, polyesters having different component ratios may be used, and polyesters having substantially the same composition may be used. However, when polyesters having substantially the same composition are used for each component, polyesters having different types and amounts of additives added at the time of polymerization of the polyesters, or polyesters whose solubility in alkali has been changed by an appropriate method, must be used. Must be used.

As a specific combination of polyester components having different alkali-solubility, PET is used as a poorly-soluble alkali component, and as an alkali-soluble component, for example, isophthalic acid mainly composed of ethylene terephthalate repeating units and having a sulfonate group is used. It is preferable to use a copolymerized polyester in which an acid component and a polyalkylene glycol having a molecular weight of 1,000 to 20,000 are copolymerized, or a copolymerized polyester in which an isophthalic acid component having a sulfonate group and an ethylene oxide adduct of a bisphenol are copolymerized. In addition, if these combinations are used, it is possible to produce polymers and composite fibers using these polymers with good operability, and since the fiber strength is large and the difference in solubility in alkali is large, the dissolution unevenness is large. Can be divided into single yarn groups without the occurrence of

The cross section of the conjugate fiber of the present invention has an asymmetric sea-island shape. Among the polyester components, the alkali-sparing polyester having strong self-extending ability is an island component, and the alkali-soluble polyester having weak self-extending ability. Are located in the sea component. A cross section arranged in an asymmetric sea-island shape means that in the cross section of a conjugate fiber, there is a region where each component is asymmetric and exists independently, and one component has a portion in contact with at least one other component. Means that this cross-sectional shape is continuous in the longitudinal direction of the fiber.

FIG. 1 shows an example of a cross-sectional shape of a composite fiber comprising a polyester component in the present invention.
As the cross-sectional shape of the conjugate fiber, an asymmetric dispersion type in which the island component has a wedge shape (a in FIG. 1), an asymmetric dispersion type in which the island component has a circular shape (b, c, d in FIG. 1) can be adopted. It is. In any of the composite fibers, the single-fiber fineness after the splitting treatment with alkali is 0.3 denier or less.

When the composite fiber of the present invention is split after exhibiting self-extensibility and crimp by heat treatment, the average single-filament fineness is
It is a group of ultrafine fibers that are less than 0.3 denier and have irregular and strong crimps. However, in order for the ultrafine fibers after heat treatment and splitting to have irregular and strong crimps, the composite fibers must It must be extensible and must have a difference in self-elongation of at least 5% between the sea component and the island component.

When the latent crimp of the composite fiber is developed by heat treatment, the ultrafine fiber group after splitting also has a crimp. In other words, since the self-extensibility of each polyester component constituting the conjugate fiber is different, if a heat treatment at about 160 to 180 ° C is applied, the portion of the fiber cross-section where the alkali-insoluble polyester component with a high elongation rate is localized is large. However, it is possible to develop a crimp in which the crest is on the crest side and the localized portion of the alkali-soluble polyester component having a small elongation percentage is on the crest valley side. Further, since the respective polyester components constituting the conjugate fiber are asymmetrically arranged, the heat treatment causes a twist in the longitudinal direction, and irregular crimps can be developed. The irregular crimps developed in the composite fiber are also fixed to the ultrafine fiber group constituting the composite fiber by heat treatment.

Further, the ultrafine fibers having an irregular crimp have an elastic modulus after boiling water treatment of 50% or more and a crimp rate of 30%.
% Or more. The modulus of elasticity after the treatment with boiling water for 30 minutes is measured by the following method. The fiber group squeezed five times with a measuring machine is used for 1/6000 (g /
(Denier) load is applied and left for 30 minutes, then put in boiling water while maintaining this state, and treated for 30 minutes.
Then, air-dry for 30 minutes, then apply a load of 1/500 (g / denier) and measure the length (a). Next, after removing the load of 1/500 (g / denier), apply a load of 1/20 (g / denier) and measure the length (b). Further, remove the load of 1/20 (g / denier), apply a load of 1/500 (g / denier) again, and measure the length (c). Then, the elastic modulus is obtained by the following equation. Modulus of elasticity (%) = [(bc) / (ba)] × 100 Further, the crimp rate after the treatment with boiling water for 30 minutes is obtained by the following equation using the length obtained above. It is. Crimping rate (%) = [(ba) / b] × 100 Among the polyester components constituting the conjugate fiber, the alkali-insoluble polyester component having strong self-elongation performance and constituting the island component Shows a self-elongation of 9% or more by heat treatment at about 160 to 180 ° C. In addition, the alkali-soluble polyester component having weak self-elongation performance, which constitutes the sea component, has a self-elongation of 4% or more. It is preferable that the difference in the self-elongation ratio between the two is 5% or more.

Here, the self-elongation ratio of the alkali-soluble polyester component having weak self-elongation performance of the sea component is 4%.
When the temperature is less than the above range, the space between the filaments of the conjugate fiber does not sufficiently increase due to the heat treatment, so that the swelling of the group of ultrafine fibers after division is apt to decrease. When the difference in self-elongation ratio between the poorly alkali-soluble polyester having strong self-stretching performance of the island component and the weakly self-stretchable polyester having weak self-stretching performance of the sea component constituting the conjugate fiber is less than 5%, Sufficient crimp does not appear in the conjugate fiber, and the swelling of the group of ultrafine fibers after splitting tends to decrease. In the present invention, the term “self-extensibility” refers to the property of irreversibly elongating a fiber when dry heat or wet heat treatment is performed without tension.

The conjugate fiber of the present invention may be produced by any method. Next, a preferred production method will be described. Using a multi-spinning facility equipped with a sea-island asymmetric dispersion type spinneret, an alkali-insoluble polyester, which has strong self-elongation performance by relaxation heat treatment after spinning, is used as an island component.
An undrawn yarn obtained by compound spinning with an alkali-soluble polyester which has weak self-stretching performance placed in the sea component,
Preferably, a highly oriented unstretched yarn spun at a high speed of 3000 m / min or more is stretched or the like, or a highly oriented unstretched yarn that has not been stretched is subjected to relaxation heat treatment and shrinkage. Thereby, the conjugate fiber of the present invention can be obtained. In this case, it is necessary to relax the supply yarn by relaxation heat treatment at an overfeed rate of 10% or more, but the overfeed rate must be set within a range where the yarn can shrink while running stably. . A non-contact heater is used for the relaxation heat treatment. For example, the yarn speed is 600 m / min.
If the temperature is on the order, heat treatment is preferably performed at 400 to 500 ° C.

According to this method, the existing equipment can be used as it is or without significant modification, and can be manufactured by using a polyester component as appropriate, so that the degree of self-elongation can be easily adjusted. Is an advantage. Further, the conjugate fiber of the present invention may be not only used as a long fiber but also shortened.

Next, the mixed fiber of the second invention and the fabric of the third invention will be described. The above-mentioned conjugate fiber can be used alone depending on the application.
It is preferable that the composite fiber and the heat-shrinkable fiber are mixed and used so that 80% by weight and the heat-shrinkable fiber become 80 to 20% by weight.

When this mixed fiber is used as a fabric and heat-treated by presetting or the like, the heat-shrinkable fiber shrinks and is located in the inner layer, while the composite fiber is crimped due to the elongation effect and the development of latent crimp. And emerge on the fabric surface. Then, when the alkali is reduced, the composite fibers exhibiting irregular and strong crimps are divided into ultrafine fibers having irregular and strong crimps.

For this reason, in a fabric obtained by using a yarn in which a conjugate fiber and a heat-shrinkable fiber are mixed, an ultrafine fiber mainly formed by dividing the conjugate fiber and having a single yarn fineness of 0.3 denier or less is used. In addition, the heat-shrinkable fibers contribute to the form stability of the fabric. Here, if the proportion of the conjugate fiber in the mixed fiber is less than 20% by weight, the fineness of the single yarn after splitting the conjugate fiber is 0.1%.
The contribution of ultrafine fibers of 3 denier or less to the hand is reduced, and if it exceeds 80% by weight, the proportion of the heat-shrinkable fibers decreases, and the form stability of the fabric decreases.

As the heat-shrinkable fiber constituting the mixed fiber together with the conjugate fiber, a thermoplastic fiber such as nylon or polyester fiber can be used. The heat shrinkage of the heat shrinkable fiber is less than 5%, especially 1 to prevent the mixed yarn from being firmly bundled even when subjected to heat treatment in dyeing or finishing.
~ 4% is preferred. The difference in shrinkage between the heat-shrinkable fibers constituting the mixed fiber and the divided ultrafine fibers is preferably 10 to 20%.

In the case where a fabric is formed by using the above-described mixed yarn and other yarns, the ratio of the mixed fiber in the fabric is 30% by weight or more, and It is preferable that the ratio of the composite fiber is 20 to 80% by weight.

As a method of blending the conjugate fiber and the heat-shrinkable fiber, etc., the two may be simply drawn together. However, the method of blending and entanglement using an interlace nozzle, a Taslan nozzle or the like, or a twisting machine or the like is used. Twisting and blending, and in the case of short fibers, blending by a conventional method are preferred.

After knitting and weaving using the mixed fiber obtained in this way, when heat treatment is performed by presetting or the like, the composite fiber exhibits self-extensibility and irregular and strong crimp, thereby forming voids between filaments. Floating on the fabric surface while increasing. Then, when alkali reduction and dyeing finishing are performed, the composite fiber is divided, and the ultrafine fibers having irregular and strong crimps are densely dispersed in the voids between the filaments.
The fabric has a calm gloss on the surface, and is rich in bulkiness and lightness, and exhibits a stable swelling feeling, excellent drape, and a soft feeling.

By appropriately selecting the combination of each polyester component constituting the conjugate fiber of the present invention, the combination of the conjugate fiber and the heat-shrinkable fiber, etc., the product can be diversified very easily.

[0027]

Next, the present invention will be described in detail with reference to examples. In the examples, the crystallinity (X _C ) was calculated from the density ρ (g / cm ³ ) measured by the density gradient tube method according to the following equation. X _C (%) = [(ρ−ρ _A ) / (ρ _C −ρ _A )] × 100 where ρ _C is the density of the crystal region (1.45 for PET).
5g / cm ³⁾ ρ _A is the case of the density (PET in amorphous regions, 1.335 g / cm ³⁾ Further, the birefringence index was measured by an interference fringe measurement method using a polarization microscope compensator. Further, the boiling water shrinkage rate is J
It was measured according to ISL-1090.

Example 1 PET (I) which is a slightly alkali-soluble component was used as an island component, and 20% by weight of polyethylene glycol having a molecular weight of 6000 and 5-sodium sulfoisophthalic acid 2 which was a readily alkali-soluble component.
PET (II) copolymerized by mol% is used as a sea component,
The fiber is spun at a weight ratio of 80 (I) / 20 (II) using a spinning facility capable of obtaining fibers having the cross section shown in FIG.
The yarn was drawn at a speed of 00 m / min to obtain a 100d / 48f highly oriented undrawn yarn.

Next, a non-contact heater temperature of 425 ° C., a relaxation rate of 27.5%, and a delivery roller speed of 60 were applied to the highly oriented undrawn yarn.
Shrink heat treatment was performed under the condition of 0 m / min. The resulting composite fiber had a self-elongation of 11% for the island component and 6% for the sea component. The relaxation rate (%) was calculated by multiplying the value obtained by dividing the difference between the supply speed (m / min) and the take-up speed (m / min) by the take-up speed (m / min) by 100.

Further, the composite fiber obtained above and a PET drawn yarn (150d / 72f) having a boiling water shrinkage of 3.5% were subjected to a relaxation rate using a commercially available interlacer (manufactured by Heberline).
A confounding treatment was performed at 2.0% and a pressure of 3.0 kg / cm ² to obtain a mixed fiber.

A yarn obtained by twisting the obtained mixed yarn at a twist number (Z) of 500 T / M is used for the warp and the weft, and the warp density is 170 / 2.54.
and a weft density of 76 yarns / 2.54 cm. After pre-setting this fabric at 180 ° C, the dyeing process is performed using a 20% by weight alkaline solution to reduce the weight.
After dissolving the alkali-soluble components and dividing the fibers into ultrafine fibers with a single-fiber fineness of 0.3 denier or less, ordinary dyeing and finishing with a disperse dye was performed. Example 2 PET (I) which is a poorly alkali-soluble component was used as an island component, and 5-sodium sulfoisophthalic acid which was a readily alkali-soluble component was used.
2.5 mol% and bisphenol A ethene oxide 10
Using PET (II) obtained by copolymerizing 5 mol% of a molar adduct as a sea component, and spinning at a weight ratio of 80 (I) / 20 (II) to obtain a fiber having a cross section shown in FIG. 1 (a). The fiber was spun using equipment and was drawn at 3100 m / min to obtain a highly oriented undrawn yarn of 100d / 48f.

Next, a non-contact heater temperature of 425 ° C., a relaxation rate of 27.5%, and a delivery roller speed of 60 were applied to the highly oriented undrawn yarn.
Shrink heat treatment was performed at 0 m / min. The resulting composite fiber had a self-elongation of 15% for the island component and 5% for the sea component.
Using the obtained composite fiber, a mixed fiber was formed in the same manner as in Example 1 and twisted, followed by weaving and post-processing.

In the woven fabrics obtained in Examples 1 and 2, the voids between filaments developed due to the self-elongation of the conjugate fiber due to the heat treatment and the voids between filaments developed by dissolving the alkali-soluble component due to the reduction of alkali. The ultrafine fibers having irregular and strong crimps of the hardly soluble alkali component are raised densely on the surface of the fabric while densely filling them. It had a fluffiness, excellent drape, and a wool-like soft texture.

[0034]

The composite fiber of the present invention becomes an ultrafine fiber having an irregular and strong crimp and an average fineness of 0.3 denier or less by splitting after exhibiting self-extensibility and crimp by heat treatment. By knitting and weaving using this composite fiber and heat-shrinkable fiber, and then heat-treating and splitting it into ultrafine fibers, the unique texture of the conventional split-type composite fiber without self-extensibility is obtained. In addition, the ultrafine fibers exhibit self-extensibility and irregular and strong crimp, and float on the fabric surface while densely filling the gaps between the filaments, so that the fabric surface has a calm luster, A fabric which is rich in lightness, has a stable swelling feeling and fluffiness, is excellent in drape property, and has a soft wool-like feel can be obtained.

Furthermore, by appropriately selecting the combination of each component constituting the composite fiber of the present invention, the combination of the composite fiber and the heat-shrinkable fiber, etc., it is possible to extremely easily use the product more and more. .

[Brief description of the drawings]

1 (a) to 1 (d) are cross-sectional views showing an embodiment of a cross-sectional shape of a conjugate fiber of the present invention.

Claims (3)

[Claims] 1. A splittable conjugate fiber in which, in a fiber cross section, a sea component composed of an alkali-soluble polester and an island component composed of an alkali-poorly-soluble polyester having an average single fiber fineness of 0.3 denier or less are asymmetrically arranged. A polyester-based self-extensible splittable conjugate fiber, wherein the self-elongation ratio differs between the sea component and the island component polyester component constituting the conjugate fiber by 5% or more. 2. The polyester-based self-extensible splittable conjugate fiber according to claim 1, comprising 20 to 80% by weight of the heat-shrinkable fiber.
Mixed fiber consisting of% by weight. 3. A fabric comprising the mixed fiber according to claim 2, wherein the ratio of the mixed fiber in the fabric is 30% by weight or more, and the polyester-based self-extensible material according to claim 1 in the fabric. A fabric in which the proportion of splittable conjugate fibers is 20 to 80% by weight.