JPH11279384A - Copolyester excellent in hygroscopicity and hygroscopic synthetic fiber using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copolyester exhibiting high hygroscopicity and a hygroscopic synthetic fiber of high commercial value. SOLUTION: The titled copolyester with excellent hygroscopicity is a copolyester comprising at least one bifunctional aromatic carboxylic acid or an ester-forming derivative thereof and at least one diol compound and contains a compound represented by the formula (wherein R1, R2 and R3 are each alkylene; 1<=k+l+m<=450; R4 and R5 are each H or alkyl; R6 and R7 are each H or alkylene; X and Y are each a polar group selected from derivatives of amino, sulfonic acid, amide, carboxyl, hydroxyl and phosphonic acid groups). The hygroscopic synthetic fiber is composed of the copolyester.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolyester having excellent hygroscopicity and a synthetic fiber using the same, and more particularly to a polyester material particularly suitably used as a material for clothing such as innerwear, middle garment and sports clothing. And a synthetic fiber using the same.

[0002]

2. Description of the Related Art Thermoplastic synthetic fibers typified by polyester and polyamide are excellent in mechanical strength, chemical resistance, heat resistance and the like, and are therefore widely used mainly for apparel use and industrial use. However, these synthetic fibers are
Due to its extremely low hygroscopicity, when used in areas where the skin is directly in contact with or close to the skin, such as innerwear, inner garments, sports clothing, etc. It is sticky and the like, and is inferior to natural fibers in terms of comfort.

In order to solve this drawback, for example, Japanese Patent Publication No. 60-475, Japanese Utility Model Publication No. 60-40612,
Alternatively, as described in JP-A-60-215835, it is not possible to obtain moisture-absorbing comfort as a fabric by mixing, twisting, or drawing various kinds of fibers with a fiber having a high equilibrium moisture content (moisture absorption). Attempts have been made to do so. Although the comfort is certainly improved by using these methods, the effect is not sufficient, and conversely, in other synthetic fiber characteristics,
When dyeing synthetic fibers, there is a problem in that contamination is caused by disperse dyes generally used, the same color is poor, and the physical properties inherent in the synthetic fibers are lost.

[0004] Also, a method is known in which acrylic acid or methacrylic acid is graft-polymerized on polyester fibers, and further, after the graft polymerization, their carboxyl groups are replaced with alkali metals to impart hygroscopicity.
That the polyester is difficult to graft polymerize,
It has not yet been put to practical use because it has potential deterioration in color fastness, light fastness, fiber physical properties, texture, and the like.

[0005] In a method of imparting hygroscopicity in a post-processing stage,
Since there are various problems at the time of dyeing or in the characteristics of the obtained fabric, in order to impart hygroscopicity at the stage of producing the fiber and to solve the above problems, the moisture absorption rate is 10 at normal humidity.
% Of a core-sheath type composite fiber in which a core portion is made of a hygroscopic resin of at least
No. 12 has proposed this. However, in this method, since the core has a high moisture absorption / water absorption rate during hot water treatment such as dyeing, the sheath is distorted due to a difference in water swelling between the core and the sheath, causing cracks on the fiber surface, There are drawbacks such as troubles easily occurring in higher order processes.

JP-A-51-136924 proposes a core-sheath composite staple comprising a hydrophilic polyester as a core component and a non-hydrophilic polyester as a sheath component. As the hydrophilic polyester, a polyalkylene glycol copolymer alone or a mixture of a small amount of a polyalkylene glycol copolymer and a small amount of a sulfonic acid or acidic phosphate derivative is used.As a staple, both ends of the fiber are increased to absorb water. It is a proposal to improve the performance. However, the present inventors have found that although the staple can improve the water absorption, it is difficult to improve the moisture absorption.

Japanese Patent Application Laid-Open No. 53-111116 proposes a core-sheath type antistatic composite fiber containing a specific polyetherester as a core component. However, the effect of the fibers is antistatic, and there is a problem that the physical properties of the fibers change with time because a polyester obtained by homopolymerizing a polyether component is used as a core component. Further, there is a problem that the polyetherester is strongly colored and the quality of the obtained final product is impaired.

Japanese Patent Application Laid-Open No. 62-267352 discloses a polyester composition containing 50 to 70% by weight of a specific polyalkylene glycol.
When this composition is fiberized alone, the fiber properties are low,
Further, it is difficult to use for clothing and industrial use due to poor water resistance.

Japanese Patent Application Laid-Open No. 6-123012 discloses a core-sheath type hygroscopic polyester fiber. This is a copolymer of an alkylene terephthalate, an alkylene sulfoisophthalate, and a polyoxyalkylene glycol blended with a block polyetherester and used as a core polymer, but the content described in the patent does not show sufficient hygroscopicity. It's hard to get, not a satisfactory level.

In addition, the present inventor has disclosed in JP-A-8-81831 the invention of a copolymer having excellent hygroscopicity obtained by copolymerizing a hydrophilic compound and a fiber having excellent hygroscopicity using the copolymerized polyester. As a result of further intensive studies, by containing a compound of a specific structure,
The inventors have found that the moisture absorption characteristics are dramatically improved, and have reached the present invention.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a copolymer polyester having a high moisture absorption which overcomes the above-mentioned conventional problems. An object of the present invention is to provide a hygroscopic synthetic fiber having high commercial value by using polyester.

[0012]

An object of the present invention is to provide a copolymerized polyester comprising at least one difunctional aromatic carboxylic acid or an ester-forming derivative thereof and at least one diol compound. General formula

[0013]

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(Wherein R1, R2 and R3 are the same or different alkylene groups having 2 to 4 carbon atoms, and 1 ≦ k + 1 + m ≦ 450, R4 and R5
Is hydrogen or an alkyl group having 1 to 10 carbon atoms, which may be the same or different, R6 and R7 are hydrogen or alkylene groups, X and Y are amino groups, sulfonic acid groups, amide groups, and carboxyl groups , A hydroxyl group and a phosphonic acid group and one polar group selected from their derivatives. ) And a synthetic polyester excellent in hygroscopicity and a synthetic fiber using the same.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In producing a copolymerized polyester, terephthalic acid,
Examples thereof include aromatic dicarboxylic acids such as isophthalic acid and naphthalene-2,6-dicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid and sebacic acid. Examples of the glycol component include ethylene glycol, propylene glycol, tetramethylene glycol, diethylene glycol, neopentyl glycol and the like. In addition, a polyol such as glycerin, trimethylolpropane, or pentaeristol may be used as long as the effects of the present invention are not impaired.

The compound to be contained in the copolymerized polyester is represented by the following general formula:

[0017]

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(Wherein R1, R2, and R3 are the same or different alkylene groups having 2 to 4 carbon atoms, and 1 ≦ k + 1 + m ≦ 450, R4, R5
Is hydrogen or an alkyl group having 1 to 10 carbon atoms, which may be the same or different, R6 and R7 are hydrogen or alkylene groups, X and Y are amino groups, sulfonic acid groups, amide groups, and carboxyl groups , A hydroxyl group and a phosphonic acid group and one polar group selected from their derivatives. ), And a specific example is preferably

[0019]

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[0020]

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[0021]

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And particularly preferably a compound represented by the following formula:

[0023]

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(Hereinafter, this compound is referred to as compound A). The copolymerization amount of the compound (I) in the copolymerized polyester may be any amount, but there is a preferable range depending on the purpose of use in terms of hygroscopicity and yarn-making properties. For example, when the copolyester is fiberized as a single component, the content is preferably 3 to 40% by weight, more preferably 5 to 40% by weight, in view of the spinning property.
-20% by weight. When the copolymer is used as a composite or a blend component, it is preferably 40 to 99% by weight, more preferably 50 to 99% by weight, from the viewpoint of moisture absorption properties and the like.
It is preferably from 90 to 90% by weight, particularly preferably from 55 to 85% by weight.

The molecular weight of the compound (I) is 600 to 600 in terms of compatibility with the polyester and dispersibility in the polyester.
20000 is preferred, and more preferably 1000-1
0000, particularly preferably 2,000 to 6,000. Most of these compounds need to be copolymerized in the polyester, but some of them may be present in a dispersed state in the polymer.

In addition, pigments such as titanium oxide and carbon black, surfactants such as alkyl benzene sulfonate, conventionally known antioxidants, coloring inhibitors, and the like may be added to the copolymerized polyester within a range not to impair the object of the present invention. Of course, a light stabilizer, an antistatic agent, etc. may be added. By obtaining a composite fiber containing the copolymerized polyester of the present invention in a fiber-forming polymer, a synthetic fiber having unprecedented high moisture absorption properties and not impairing the fiber properties of the fiber-forming polymer can be obtained. Can be.

In the present invention, examples of the fiber-forming polymer include polyolefins such as polyethylene and polypropylene, polyamides such as nylon 6 and nylon 66, and polyesters such as polyethylene terephthalate and polybutylene terephthalate, but are not limited thereto. Not something. Preferably, it is a polyester mainly composed of polyethylene terephthalate, which is the most versatile synthetic fiber for clothing.

Examples of the form of the synthetic fiber include a single fiber, a core-sheath composite fiber, a core-sheath composite hollow fiber, a sea-island composite fiber, a laminated composite fiber, and a blend fiber. It can be used as a component in any ratio.

For example, in the case of the core-sheath type composite fiber and the core-sheath type composite hollow fiber, the composite ratio (% by weight) of the copolymerized polyester of the present invention in the core portion is as follows: core / sheath = 5/95 to 90/10.
It is preferable that More preferably, 7/93 or more
It is 50/50, particularly preferably 10/90 to 30/70. The composite ratio can be arbitrarily selected for dyeing use and non-dyeing use. The lower limit of the composite ratio of the core is set for the purpose of imparting sufficient hygroscopicity, and the upper limit of the composite fiber ratio is set from the viewpoint of preventing a decrease in spinnability and a decrease in fiber properties.

Also in the sea-island composite fiber or the laminated composite fiber, the composite ratio of the copolymerized polyester (island component or one component) of the present invention to be used is preferably 5 to 90% by weight. It is more preferably from 7 to 50% by weight, particularly preferably from 10 to 30% by weight.

It can be arbitrarily selected for use for dyeing and for use without dyeing. The lower limit of the composite ratio is set for the purpose of imparting sufficient hygroscopicity, and the upper limit of the composite fiber ratio is set from the viewpoint of preventing a decrease in spinnability and physical properties of fibers.

In the case of synthetic fibers obtained by blending a copolymerized polyester blend with a fiber-forming resin, the blending ratio of the copolymerized polyester of the present invention is 3 to 40 with respect to the total amount of the polymer.
Weight percent. Preferably 5-35% by weight,
More preferably, it is 7 to 30% by weight. The lower limit of the mixing ratio is set for the purpose of imparting sufficient hygroscopicity, and the upper limit of the mixing ratio is set from the viewpoint of preventing a reduction in spinnability and a decrease in fiber properties.

In the present invention, the main component to be combined with the fiber-forming polymer is the above-mentioned copolymerized polyester.
Polyolefins, polyamides, polyesters, polycarbonates and the like may be contained as long as the effect is not impaired. In addition to the pigments such as titanium oxide and carbon black, conventionally known antioxidants, coloring inhibitors, light stabilizers, antistatic agents and the like may be added to the fiber-forming polymer.

In the present invention, as a method for producing a copolyester single fiber or a composite fiber using the polyester and the above-mentioned copolyester, a conventionally known method can be used. 1 shows a method for producing a fiber. For example, in the case of a core-sheath composite fiber, polyester (sheath) and the copolymerized polyester of the present invention (core)
Are separately melted, guided to a spinning pack, formed into a core-sheath composite flow in a spinneret, and spun from a discharge hole.

After taking out the spun filament yarn at a predetermined speed, it is once wound up in a package, and the obtained undrawn yarn is drawn by a usual drawing machine. The drawing may be performed continuously without winding after winding the spun yarn, and may be performed at a high speed of 4000 m / min or more. A method of obtaining performance may be adopted.

As a direct spinning and drawing method, for example, a spun yarn is taken at 1000 to 5000 m / min,
A method of stretching and heat-setting at 0 to 6000 m / min. The composite form of the synthetic fiber of the present invention may be concentric, eccentric, or multi-island, and the cross-sectional shape of the fiber may be not only round but also irregular cross-section such as triangular, flat, or multi-lobed. Further, the filamentous form of the synthetic fiber may be either a filament or a staple, and can be obtained by an ordinary method.
The fabric form can be appropriately selected depending on the purpose, such as a woven fabric, a knitted fabric, or a nonwoven fabric.

[0037]

The present invention will be described in more detail with reference to the following examples. In addition, each characteristic value in an Example was calculated | required by the following method. A. Intrinsic viscosity [η] of polyester An orthochlorophenol solution was determined at 25 ° C. B. Moisture absorption difference ΔMR of polymer and fiber

The moisture absorption rate of the polymer is about 2
Cut into cubes of mm squares, and in the case of fibers, the original yarn is made into a tubular knitted fabric, and a constant temperature and humidity chamber is used under the absolute dry weight and atmosphere of 20 ° C. × 65% RH or 30 ° C. × 90% RH. From the weight change with the weight after standing for 24 hours in (Tavai's PR-2G), it was determined by the following equation.

Moisture absorption (%) = [(weight after moisture absorption−weight at absolute dryness) / weight at absolute dryness] × 100 20 ° C. × 65% RH and 30 ° C. × 90% measured above.
From the moisture absorption rate under the condition of RH (referred to as MR1 and MR2, respectively), a moisture absorption rate difference ΔMR (%) = MR2-MR1 is obtained.

Here, the moisture absorption rate difference ΔMR is a driving force for obtaining comfort by releasing the moisture in the clothes to the outside air when the clothes are worn, and performs light to medium work or light to medium exercise. This is the difference in moisture absorption between the temperature inside the clothes typified by 30 ° C. × 90% RH and the outside air temperature typified by 20 ° C. × 65% RH.

In the present invention, this ΔMR is used as a parameter as a measure of the hygroscopicity evaluation. The greater the ΔMR, the higher the hygroscopicity and the better the comfort when worn. In order to obtain comfortable wearing in practical use, the fiber is preferably 1% or more.

C. Strength and elongation Using a Tensilon tensile tester manufactured by Toyo Baldwin Co., a value was determined from a stress-strain curve measured under the conditions of a test length of 20 cm and a tensile speed of 10 cm / min.

Example 1 Dimethyl terephthalic acid 19 was used as the copolymerized polyester.
4 parts, ethylene glycol 124 parts, manganese acetate 0.
1 part and 0.06 part of antimony trioxide,
After performing a transesterification reaction while distilling methanol at ~ 230 ° C, a solution of 0.08 parts of trimethyl phosphate in ethylene glycol and the compound A2 having a molecular weight of 4000 were prepared.
1.3 parts, 0.2 parts of Irganox 1010 (manufactured by Ciba-Gaiky) as an antioxidant, and 0.2 parts of silicon as an antifoaming agent were added, and the temperature was raised to 250 ° C to 280 ° C under a reduced pressure of 1.0 mmHg. Polymerization was carried out for 4 hours to obtain a copolymerized polyester. The ratio of compound A copolymerized with this copolymer was 10% by weight. The moisture absorption rate ΔMR of the obtained copolymerized polyester was 2.4%.

The copolyester was melted and discharged from a concentric die to obtain an undrawn yarn, which was then drawn and heat-treated to obtain a 75 denier, 24 filament concentric synthetic fiber. This fiber was formed into a tubular knit, and the moisture absorption characteristics of the tubular knitted fabric after scouring were measured. As a result, ΔMR was 2.4%, and the high elongation characteristics were also good. Examples 2 to 5 and Comparative Example 1 A copolymerized polyester was obtained in the same manner as in Example 1 except that the copolymerization ratio of the compound A in the copolymerized polyester was changed.

In Comparative Example 1, the moisture absorption characteristics were low.

[0046]

[Table 1]

Examples 6 to 11 Copolymerized polyesters were obtained in the same manner as in Example 1 except that the molecular weight of Compound A was changed. Fibers were formed in the same manner as in Example 1 and the fiber properties are summarized in Table 2. When the molecular weight of compound A increases (Example 11)
ΔMR tends to decrease.

[0048]

[Table 2]

Example 12 Dimethyl terephthalic acid 19 was used as the copolymerized polyester.
4 parts, 124 parts of ethylene glycol, and 0.1 part of tetrabutyl titanate were added, and a transesterification reaction was performed while distilling methanol at 140 to 230 ° C., followed by a solution of 0.08 part of trimethyl phosphate in ethylene glycol and a molecular weight. 288 parts of 4000 compound A, as antioxidant
0.2 parts of Irganox 1010 (manufactured by Ciba-Gaiky), 0.2 parts of silicon as an antifoaming agent and 0.1 parts of tetrabutyl titanate are added, and the mixture is heated to 250 ° C. under a reduced pressure of 1.0 mmHg.
Polymerization was performed for 4 hours under the conditions described above to obtain a copolymerized polyester. The ratio of compound A copolymerized with this copolymer was 60 wt%. The moisture absorption rate ΔMR of the obtained copolymerized polyester was 28%.

The copolymerized polyester is used as a core component, and polyethylene terephthalate having an intrinsic viscosity of 0.70 is melted separately as a sheath component. The core / sheath ratio (weight ratio) becomes 15/85 from the concentric core-sheath composite die. To obtain a 75 denier, 24 filament concentric core-sheath composite fiber. This fiber was formed into a tubular knit, and the moisture absorption characteristics of the tubular knitted fabric after scouring were measured. As a result, ΔMR was 2.8%.

Examples 13 to 17 Copolymerized polyesters were obtained in the same manner as in Example 12, except that the content of Compound A was changed. Fibers were formed in the same manner as in Example 12 and the fiber properties are summarized in Table 3.

[0052]

[Table 3]

Examples 18 to 22 The copolymer polyester obtained in Example 12 was used as a core component, and polyethylene terephthalate having an intrinsic viscosity of 0.70 was melted separately as a sheath component in the same manner as in Example 12 to obtain a concentric core-sheath composite. Change the core-sheath composite ratio from the die to obtain an undrawn yarn,
Then, by stretching and heat treatment, 75 denier, 2
A 4-filament concentric core-sheath composite fiber was obtained.

The fiber properties are summarized in Table 4. As the core ratio is increased, ΔMR is improved, but a decrease in strong elongation is observed.

[0055]

[Table 4]

Examples 23 to 27 The copolymerized polyester obtained in Example 1 was simultaneously melt-mixed with an extruder at an appropriate weight ratio to polyethylene terephthalate having an intrinsic viscosity of 0.70, and this was mixed with a circular die. By discharging, an undrawn yarn was obtained, followed by drawing and heat treatment to obtain a 75 denier, 24 filament polyester fiber.

The fiber properties are summarized in Table 5. As the blend ratio is increased, ΔMR is improved, but a decrease in elongation is recognized.

[0058]

[Table 5]

[0059]

As described above, the copolymerized polyester obtained according to the present invention has a very high hygroscopic property, and the synthetic fiber using the same has a sufficient level of wearing comfort. It has hygroscopicity, dry touch texture, high color fastness and light fastness. The synthetic fiber of the present invention is suitable for underwear, shirts / blouses, middle garments, sportswear, slacks, outer garments, linings, and even sheets and futon covers, and is extremely practical. is there.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a core-sheath composite hollow fiber according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copolyester (of this invention) 2 Fiber-forming polyester 3 Hollow part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshihiro Sasaki 4845 Mishima-shi, Shizuoka Toray Industries, Inc. Mishima Plant (72) Inventor Masao Nakagawa 11-11 Hitotsubashi-Honcho, Higashiyama-ku, Kyoto-shi, Kyoto Sanyo Chemical Industry Co., Ltd. Inside

Claims (6)

[Claims] 1. A copolymerized polyester comprising at least one bifunctional aromatic dicarboxylic acid or an ester-forming derivative thereof and at least one diol compound, wherein the polyester is represented by the following general formula: (Wherein, R1, R2 and R3 are the same or different alkylene groups having 2 to 4 carbon atoms, and 1 ≦ k + 1 + m ≦ 450, and R4 and R5 are the same. Or hydrogen or an alkyl group having 1 to 10 carbon atoms which may be different, R6 and R7 are a hydrogen or an alkylene group, X and Y are an amino group, a sulfonic acid group, an amide group, a carboxyl group, a hydroxyl group and a phosphonic acid group; Represents one polar group selected from these derivatives.)
A copolymer polyester excellent in hygroscopicity, comprising a compound represented by the formula: 2. The copolyester excellent in hygroscopicity according to claim 1, wherein the compound represented by the general formula is copolymerized in an amount of 3 to 90% by weight based on the total weight of the polymer. 3. The compound represented by the above general formula having a molecular weight of 60
The copolyester excellent in hygroscopicity according to claim 1 or 2, which has a molecular weight of 0 to 20,000. 4. A synthetic fiber comprising the copolymerized polyester according to claim 1, which is excellent in hygroscopicity. 5. A conjugate fiber having excellent hygroscopicity, comprising a fiber-forming polymer and the copolymerized polyester according to claim 1 as a constituent. 6. The synthetic fiber excellent in hygroscopicity according to claim 5, wherein the content of the copolyester is 3 to 40% by weight based on the total weight of the polymer.