JP2009235242A - Copolyester and polyester fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: an elastic body polyetherester having advantageous moisture adsorption and desorption properties and advantageous durability relative to the moisture adsorption and desorption, having self-expanding and contracting properties through which the polyetherester reversibly expands and contracts by the moisture adsorption and desorption, and capable of being recycled; and a fiber thereof. <P>SOLUTION: This polyetherester elastomer is one having as a hard segment, polybutylene terephthalate copolymerized with a specific organic metal sulfonate and having as a soft segment, polyoxyethylene glycol containing a specific polyoxyethylene glycol. Provided is also a fiber thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a copolyester and a polyester elastic fiber, which have good moisture absorption / release properties, reversibly expand / contract due to water absorption / release water, and in particular, a fabric that exhibits unprecedented comfort when made into fibers.

  Conventionally, polyurethane elastic fibers are mainly used as elastic bodies, particularly elastic fibers for clothing and industrial materials, but have the disadvantages of poor heat resistance, chemical resistance, and weather resistance (light). In addition, since a dry spinning process using a solvent is necessary for production, solvent recovery is necessary, and there is a problem of low productivity and high energy consumption. Furthermore, polyurethane elastic fibers are difficult to recycle, and have many problems toward the arrival of a recycling society in the future, such as generating harmful gases derived from nitrogen atoms contained during combustion.

  Against this backdrop, polyether ester elastic fibers, which can be melt-spun and have a highly crystalline polyester such as polyalkylene terephthalate as a hard segment and polyalkylene glycol as a soft segment, have high productivity. It has been put to practical use by taking advantage of its excellent heat resistance and heat setability. Furthermore, since it is recyclable and no harmful gas is generated, future development is expected as an elastic fiber suitable for a recycling society (see, for example, Patent Documents 1 to 3).

  As such a polyether ester elastic fiber, a polyether ester elastic fiber using polybutylene terephthalate as a hard segment and polyoxybutylene glycol as a soft segment is used as an elastic performance comparable to that of a polyurethane elastic fiber. . However, both of these hard segments and soft segments are generally hydrophobic, and almost no polyether ester elastic fiber having hydrophilic properties such as hygroscopicity and water absorption is practically used.

  On the other hand, elastic fibers having moisture absorption performance have been proposed, but only specific examples of polyurethane elastic bodies containing a water-absorbing resin having a water absorption rate of 500 to 4,000% by weight are described (for example, patents). Reference 4).

  Moreover, there is a limit to improving the comfort of a fiber or even a garment simply by making the fiber itself hygroscopic as previously proposed, and there is a need for an elastic fiber having a new function. It has been.

  As a method for solving these problems, a hygroscopic elastic fiber made of a polyether ester elastomer having a polybutylene terephthalate as a hard segment and polyoxyethylene glycol as a soft segment, which is copolymerized with a specific organic sulfonic acid metal salt, has been proposed. (For example, refer to Patent Document 5). However, the hygroscopicity of the polyetherester elastomer fiber obtained by this method tends to decrease in long-term use, and improvement of its durability has been demanded.

Japanese Patent Publication No. 47-14054 Japanese Patent Laid-Open No. 48-10346 JP-A-57-77317 International Publication No. 00/047802 Pamphlet International Publication No. 04/113599

  The present invention has been made against the background of the above-described conventional technology. The purpose of the present invention is a fabric that has good moisture absorption / release properties, reversibly expands / contracts due to water absorption / release water, and exhibits unprecedented comfort especially when made into fibers. Is to provide a copolyester and a polyester fiber.

As a result of repeated studies in view of the background technology, the present inventors have found that the object of the present invention can be achieved by the following polyether ester elastic fiber. That is, in the present invention, a polybutylene terephthalate component is copolymerized with a dihydroxy compound component represented by the following general formula (1) or a dihydroxy compound component represented by the following general formula (1) and a polyoxyethylene glycol component. Furthermore, a copolyester having an intrinsic viscosity of 0.6 dL / g or more obtained by copolymerizing an organic sulfonic acid metal salt component represented by the following general formula (2):
The copolymerization rate of the organic sulfonic acid metal salt component represented by the following general formula (2) is 0.1 to 20.0 mol% based on the acid component constituting the copolymer polyester, and the polybutylene terephthalate component and The total weight ratio of the organic sulfonic acid metal salt component represented by the general formula (2) and the total of the dihydroxy compound component and the polyoxyethylene glycol component represented by the following general formula (1) is 30:70 to 70: This is a copolymer polyester of 30, and the object of the present invention can be achieved by the present invention.

［上記式中、Ｒは炭素数１〜１８個の炭化水素基を表し、ｎは２０〜２００の数を表す。］

[In the above formula, R represents a hydrocarbon group having 1 to 18 carbon atoms, and n represents a number of 20 to 200. ]

［上記式中、Ｒ_１は芳香族炭化水素基又は脂肪族炭化水素基を、Ｘ_１はエステル形成性官能基を、Ｘ_２はＸ_１と同一若しくは異なるエステル形成性官能基又は水素原子を表し、Ｍ_１はアルカリ金属又はアルカリ土類金属であり、Ｍ_１がアルカリ金属の場合ｊは１を、Ｍ_２がアルカリ土類金属の場合ｊは２を表す。］

[In the above formula, R ₁ represents an aromatic hydrocarbon group or an aliphatic hydrocarbon group, X ₁ represents an ester-forming functional group, and X ₂ represents an ester-forming functional group or a hydrogen atom that is the same as or different from X _1. , M ₁ is an alkali metal or an alkaline earth metal, j represents 1 when M ₁ is an alkali metal, and j represents 2 when M ₂ is an alkaline earth metal. ]

  Furthermore, the present invention relates to a copolymer polyester in which the organic sulfonic acid metal salt component is a compound represented by the following general formula (3), and a moisture absorption rate at 35 ° C. and 95% RH obtained by spinning such copolymer polyester. 5.0% or more, and the water absorption elongation rate is 10.0% or more.

［上記式中、Ｒ_２は芳香族炭化水素基又は脂肪族炭化水素基を表し、Ｍ_２はアルカリ金属を表す。］

[In the above formula, R ₂ represents an aromatic hydrocarbon group or an aliphatic hydrocarbon group, and M ₂ represents an alkali metal. ]

  According to the present invention, it is possible to obtain a fiber that has good hygroscopicity, has hygroscopic properties, and has washing durability, and is elongated by water absorption. In addition, it is possible to provide a fabric that expresses unprecedented comfort, in particular, when the knitted fabric has a large mesh opening at the time of water absorption, and there is little stickiness and non-stickiness.

  In the copolymerized polyester of the present invention, a dihydroxy compound component having an ethyleneoxy unit represented by the following general formula (1) needs to be copolymerized with a polybutylene terephthalate component. When the former component or the like is a hard segment and the dihydroxy compound component or the like represented by the following general formula (1) functions as a soft segment, it becomes a polyether ester elastomer.

［上記式中、Ｒは炭素数１〜１８個の炭化水素基を表し、ｎは２０〜２００の数を表す。］

[In the above formula, R represents a hydrocarbon group having 1 to 18 carbon atoms, and n represents a number of 20 to 200. ]

  The polybutylene terephthalate that can be a hard segment may be copolymerized with other components, but preferably contains at least 70 mol% of butylene terephthalate units. The content of butylene terephthalate is more preferably 80 mol% or more, and still more preferably 90 mol% or more.

  The polybutylene terephthalate may be copolymerized with other components as long as the achievement of the object of the present invention is not substantially impaired. As other copolymerization components, dicarboxylic acid components, for example, naphthalenedicarboxylic acid, isophthalic acid, diphenyldicarboxylic acid, diphenyloxyethanedicarboxylic acid, adipic acid, sebacic acid, aromatics such as 1,4-cyclohexanedicarboxylic acid, Examples thereof include aliphatic and alicyclic dicarboxylic acid components. Further, a tri- or higher functional polycarboxylic acid such as trimellitic acid or pyromellitic acid, or a hydroxycarboxylic acid such as β-hydroxyethoxybenzoic acid or p-oxybenzoic acid may be used as a copolymerization component. . Examples of the diol component include aliphatic and fatty acids such as trimethylene glycol, ethylene glycol, cyclohexane-1,4-dimethanol, neopentyl glycol, and 2,2′-bis (4-β-hydroxyethoxyphenyl) propane. Examples thereof include cyclic and aromatic diol components. Furthermore, trifunctional or higher functional polyols such as glycerin, trimethylolpropane and pentaerythritol may be used as a copolymerization component.

  On the other hand, the dihydroxy compound having an ethyleneoxy unit that can be a soft segment includes a polyoxyethylene glycol unit and is a dihydroxy compound represented by the following general formula (1), or a hydroxy group at both ends of the dihydroxy compound and a long chain. It may be a mixture with a general polyoxyalkylene glycol having The alkylene group of the polyoxyalkylene glycol having hydroxy groups at both ends of the long chain is not particularly limited, but polyoxyethylene glycol and polyoxytetramethylene glycol are preferably used. As the polyoxyethylene glycol (polyethylene glycol), those having a number average molecular weight of preferably 1000 to 8000, more preferably 2000 to 6000 can be used.

［上記式中、Ｒは炭素数１〜１８個の炭化水素基を表し、ｎは２０〜２００の数を表す。］
上記のジヒドロキシ化合物の数平均分子量としては、４００〜８０００が好ましく、なかでも１０００〜６０００がより好ましく、１５００〜４０００がさらに好ましい。

[In the above formula, R represents a hydrocarbon group having 1 to 18 carbon atoms, and n represents a number of 20 to 200. ]
As a number average molecular weight of said dihydroxy compound, 400-8000 are preferable, 1000-6000 are more preferable especially, 1500-4000 are further more preferable.

  In addition, in order to achieve the above-described high moisture absorption rate and water absorption elongation rate, the polyether sulfonate elastomer (copolyester) may be copolymerized with an organic sulfonic acid metal salt component represented by the following general formula (2). is necessary.

［上記式中、Ｒ_１は芳香族炭化水素基又は脂肪族炭化水素基を、Ｘ_１はエステル形成性官能基を、Ｘ_２はＸ_１と同一若しくは異なるエステル形成性官能基又は水素原子を表し、Ｍ_１はアルカリ金属又はアルカリ土類金属であり、Ｍ_１がアルカリ金属の場合ｊは１を、Ｍ_２がアルカリ土類金属の場合ｊは２を表す。］

[In the above formula, R ₁ represents an aromatic hydrocarbon group or an aliphatic hydrocarbon group, X ₁ represents an ester-forming functional group, and X ₂ represents an ester-forming functional group or a hydrogen atom that is the same as or different from X _1. , M ₁ is an alkali metal or an alkaline earth metal, j represents 1 when M ₁ is an alkali metal, and j represents 2 when M ₂ is an alkaline earth metal. ]

In the above formula, R ₁ is an aromatic hydrocarbon group or an aliphatic hydrocarbon group, preferably an aromatic hydrocarbon group having 6 to 15 carbon atoms or an aliphatic hydrocarbon group having 10 or less carbon atoms. Particularly preferred functional group R ₁ is an aromatic hydrocarbon group having 6 to 12 carbon atoms, especially a benzene ring. M ₁ is an alkali metal or an alkaline earth metal, and j is 1 or 2. Among them, those in which M ₁ is an alkali metal (for example, lithium, sodium or potassium) and j is 1 are preferable. X ₁ represents an ester-forming functional group, and X ₂ represents the same or different ester-forming functional group as X ₁ or represents a hydrogen atom, and is preferably an ester-forming functional group. The ester-forming functional group may be any group that reacts and binds to the main chain or terminal of the polyether ester, and specifically includes the following functional groups.

［上記式中、Ｒ’は炭素数１〜６個の低級アルキル基又はフェニル基を表し、ａ及びｄは１〜１０の整数を示し、ｂは２〜６の整数を表す。］

[In the above formula, R ′ represents a lower alkyl group having 1 to 6 carbon atoms or a phenyl group, a and d represent an integer of 1 to 10, and b represents an integer of 2 to 6. ]

  Preferable specific examples of the organic sulfonic acid metal salt represented by the general formula (2) include lithium 3,5-dicarbomethoxybenzenesulfonate, sodium 3,5-dicarbomethoxybenzenesulfonate, 3,5-dicarboxylate. Potassium carbomethoxybenzenesulfonate, lithium 3,5-dicarboxybenzenesulfonate, sodium 3,5-dicarboxybenzenesulfonate, potassium 3,5-dicarboxybenzenesulfonate, 3,5-bis (β-hydroxyethoxy) Carbonyl) lithium benzenesulfonate, sodium 3,5-bis (β-hydroxyethoxycarbonyl) benzenesulfonate, potassium 3,5-bis (β-hydroxyethoxycarbonyl) benzenesulfonate, 2,6-dicarbomethoxynaphthalene 4-sulphonate lithium, 1,6-dicarbomethoxynaphthalene-4-sulfonic acid sodium salt, 2,6-dicarbomethoxynaphthalene-4-sulfonic acid potassium salt, 2,6-dicarboxynaphthalene-4-sulfonic acid lithium salt, 2,6-dicarboxynaphthalene Sodium 4-sulfonate, potassium 2,6-dicarboxynaphthalene-4-sulfonate, sodium 2,6-dicarbomethoxysnaphthalene-1-sulfonate, 2,6-dicarbomethoxynaphthalene-3-sulfonic acid Sodium, sodium 2,6-dicarbomethoxynaphthalene-4,8-disulfonate, sodium 2,6-dicarboxynaphthalene-4,8-disulfonate, sodium 2,5-bis (hydroxyethoxy) benzenesulfonate, α -Sodium sulfosuccinic acid etc. can be mentioned. The said organic sulfonic acid metal salt may be used individually by 1 type, or may be used together 2 or more types.

  In the present invention, the organic sulfonic acid metal salt component represented by the following general formula (3) is copolymerized as the organic sulfonic acid metal salt component, so that the moisture absorption rate and water absorption elongation rate of the resulting polyester elastic fiber are markedly increased. It is more preferable in that it can be increased. According to our research, by copolymerizing such organic sulfonic acid metal salts, it is possible to achieve a very high level such as a water absorption elongation rate of 10.0% or more, and a fabric with superior comfort can be easily obtained. all right.

［上記式中、Ｒ_２は芳香族炭化水素基又は脂肪族炭化水素基を表し、Ｍ_２はアルカリ金属を表す。］

[In the above formula, R ₂ represents an aromatic hydrocarbon group or an aliphatic hydrocarbon group, and M ₂ represents an alkali metal. ]

In the above formula, R ₂ is an aromatic hydrocarbon group or an aliphatic hydrocarbon group, which is the same as the definition of the functional group R ₁ in the general formula (2) described above, M ₂ is an alkali metal, and is described above. The definition of M ₁ in the general formula (2) is almost the same. Preferred examples of such organic sulfonic acid metal salts include lithium 3,5-bis (β-hydroxyethoxycarbonyl) benzenesulfonate, sodium 3,5-bis (β-hydroxyethoxycarbonyl) benzenesulfonate, 3,5 -Examples include potassium di (β-hydroxyethoxycarbonyl) benzenesulfonate.

  If the amount of copolymerization of the above organic sulfonic acid metal salt component is too large, the melting point of the obtained polyetherester elastomer (copolyester) is lowered, and heat resistance, weather resistance (light) resistance, chemical resistance, etc. are lowered. Therefore, it is necessary to set the content in the range of 0.1 to 20.0 mol% based on the total acid components constituting the polyetherester elastomer (copolyester). On the other hand, even if the amount of copolymerization is too small, the moisture absorption rate and the water absorption elongation rate tend to decrease, and it is more preferably in the range of 0.5 to 15.0 mol%.

  In the present invention, the total of the polybutylene terephthalate component and the organic sulfonic acid metal salt component represented by the general formula (2) (hereinafter sometimes referred to as a hard segment) and the above general formula (1). The weight ratio of the sum of the dihydroxy compound component and the polyoxyethylene glycol component (hereinafter sometimes referred to as a soft segment) is preferably in the range of 30:70 to 70:30, more preferably 60:40 to 40: The range is 60. When the weight ratio of the hard segment exceeds 70% by weight, when the obtained copolymer polyester is made into an elastic fiber, the elongation becomes low, it becomes difficult to use for high stretch applications, and the hygroscopicity tends to decrease. is there. If the weight ratio of the hard segment is less than 30% by weight, the ratio of the crystal part of the polybutylene terephthalate component tends to be low, so that the strength of the fiber tends to decrease. The unreacted rate of the represented dihydroxy compound (polyoxyethylene glycol) is increased, and when it is made into a fiber, it becomes inferior in high-order processing processes such as scouring and dyeing, and washing fastness when used as a product. Cheap.

  When the copolymerized polyester (polyether ester elastomer) of the present invention is used as a fiber, the moisture absorption at 35 ° C. and 95% RH (relative humidity) is 5.0% or more, and the water absorption elongation is 10.0% or more. It is important. As a result, when the polyester fiber is an elastic fiber, the woven or knitted fabric made of the elastic fiber stretches when the sweat is absorbed, and the eyes of the woven or knitted fabric open to release the moisture inside the garment. When dried, the fiber returns to its original length even after shrinking, the eyes of the knitted fabric are clogged, and the fabric has a so-called self-regulating function that does not release the temperature inside the garment. .

  When the moisture absorption rate is less than 5.0%, there is a sticky feeling and stuffiness, and when the water absorption elongation rate is less than 10.0%, the reversible elongation / shrinkage characteristics due to water absorption / release are insufficient, and the eyes of the woven / knitted fabric are sufficiently opened. The cloth excellent in comfort cannot be obtained. On the other hand, in the polyester (elastic) fiber of the present invention composed of the above-described polyether ester elastomer, if the moisture absorption rate or the water absorption elongation rate becomes too large, the elastic performance, heat resistance, weather resistance (light) resistance, chemical resistance Tend to deteriorate. For this reason, the moisture absorption rate is preferably in the range of 5.0 to 45.0%, more preferably in the range of 10.0 to 40.0%. The water absorption elongation is preferably in the range of 10.0 to 100.0%, more preferably in the range of 10.0 to 80.0%, and still more preferably in the range of 15.0 to 60.0%. .

  The copolymer polyester (polyether ester elastomer) of the present invention is prepared by, for example, transesterifying a raw material containing dimethyl terephthalate, tetramethylene glycol and a dihydroxy compound represented by the general formula (1) in the presence of a transesterification catalyst. And bis (ω-hydroxybutyl) terephthalate and / or oligomers are formed, and then melt polycondensation is performed under high temperature and reduced pressure in the presence of a polycondensation catalyst and a stabilizer. As the transesterification catalyst, an alkali metal salt such as sodium, an alkaline earth metal salt such as magnesium or calcium, or a metal compound such as titanium, zinc or manganese is preferably used.

  As the polycondensation catalyst, it is preferable to use a germanium compound, an antimony compound, a titanium compound, a cobalt compound, or a tin compound. The amount of the transesterification catalyst or polycondensation catalyst used is not particularly limited as long as it is an amount necessary for advancing the transesterification reaction or polycondensation reaction, and more than one type of transesterification catalyst or polycondensation catalyst is used. It is also possible to use a condensation catalyst in combination.

  In addition, the above-mentioned polyether ester elastomer is added with a hindered phenol-based compound or a hindered amine-based compound, which will be described later, not only suppressing the decrease in the intrinsic viscosity of the polymer during melt spinning, It also has an effect of suppressing heat deterioration, oxidation deterioration, light deterioration, etc. of the elastic fiber, and is more preferable. Especially, since it has the effect which accelerates | stimulates the polycondensation reaction of the polyetherester elastomer of this invention to use the hindered phenol type compound which has a double bond in the molecule | numerator shown by following General formula (4). It is more preferable in that an elastic fiber having a high intrinsic viscosity is easily obtained, and a polyether ester elastic fiber having high hygroscopicity and water absorption elongation can be easily produced.

In the general formula (4), each of the substituents R ₃ and R ₄ independently represents a monovalent organic group having 1 to 6 carbon atoms, and either or both of the substituents R ₃ and R ₄ are used here. When a plurality of are present, the plurality of substituents R ₃ or R ₄ may be the same or different, m and n are each independently an integer of 0 to 4, and The group R ₅ represents a hydrogen atom or an organic group having 1 to 5 carbon atoms.

  Specific examples of the hindered phenol compound having a double bond in the molecule include the following compounds (5) to (8). Among them, the one represented by the following formula (5) is particularly preferable because the above-described elastic fiber having high hygroscopicity and water absorbability can be easily obtained.

Here, in the above (5) to (8), t-C ₅ H ₁₁ represents a C (CH ₃ ) ₂ CH ₂ CH ₃ group, and t-C ₄ H ₉ represents a —C (CH ₃ ) ₃ group. To express.

  The transesterification catalyst can be supplied at the initial stage of the transesterification reaction in addition to the preparation of the raw material. The stabilizer can be supplied at any stage up to the end of the polycondensation reaction, but is preferably added at the end of the transesterification reaction. Furthermore, the polycondensation catalyst can be supplied by the early stage of the polycondensation reaction step.

  The above-mentioned copolymer polyester of the present invention, if necessary, in addition to the hindered phenolic compound and hindered amine compound, UV absorber, flame retardant, fluorescent whitening agent, matting agent, color adjuster, antifoaming agent, or You may mix | blend 1 or more types with another additive in the range which does not impair the effect of invention. In order to further increase the intrinsic viscosity of the copolyester (polyether ester elastomer), in addition to the above-described method, a method of solid-phase polymerization of the polyether ester elastomer, a synthesis step of the polyester ether elastomer, and a chain at the melt spinning step. A method using an extender can also be employed. Preferable specific examples of the chain extender used at this time include oxazoline compounds such as 2,2'-bis (2-oxazoline), N, N'-terephthaloylbiscaprolactam and the like.

  The intrinsic viscosity of the copolyester (polyether ester elastomer) described above needs to be 0.6 dL / g or more. If the above intrinsic viscosity is 0.6 dL / g or less, sufficient strength for use cannot be obtained. On the other hand, when the intrinsic viscosity is too large, not only the yarn-making property is lowered but also the production cost is increased. For this reason, the intrinsic viscosity is more preferably in the range of 0.6 to 1.2 dL / g.

  When the polyetherester elastomer of the present invention is used as an elastic fiber, for example, the pelletized polyetherester is melted and extruded from a spinneret, and is kept warm for at least 10 cm, preferably at least 15 cm, immediately below the base. The oil agent is applied at a position within 5 m, preferably within 4 m from directly under the base, and the take-up speed is 300 to 1200 m / min, preferably 400 to 980 m / min. It can manufacture by winding up by 3 to 1.6 times, preferably 1.4 to 1.5 times. However, if the winding draft ratio is less than 1.3, the tension applied to the fibers is insufficient between the godet rollers and between the godet rollers and the take-up machine, and the fibers are undesirably caught by the godet rollers and broken. As mentioned above, keep the bottom of the base warm, keep the spinning speed as low as possible, keep the distance to the oil application device not long, so that the orientation does not advance, and the elastic fiber after taking up is as much fiber as possible In order to prevent the fibers from being stretched, it is necessary to reduce the winding draft as much as possible within the range in which the fibers can be wound, so that the moisture absorption rate is 5.0% or more and the water absorption elongation rate is 10.0% or more. Then, it is preferable. From this point of view, it is not preferable to stretch or further heat-treat the elastic fiber after winding it or continuously after pulling it.

  In the elastic fiber, the elongation at break is set to 400% or more and the boiling water shrinkage of the elastic fiber is set to 10% or more to increase the hygroscopicity and the water absorption elongation rate. This is preferable in that thread breakage due to slight blurring can be reduced. As said breaking elongation, the range of 400-900% is more preferable, More preferably, it is the range of 400-800%.

  Hereinafter, the present invention will be described specifically by way of examples. In addition, each physical property in an Example was measured with the following method.

(1) Intrinsic viscosity (IV)
0.6 g of polyester was dissolved by heating in 50 ml of orthochlorophenol, then cooled to room temperature, and the viscosity of the obtained polyester solution was measured at 35 ° C. using an Ostwald viscosity tube. The intrinsic viscosity (IV) of the polyester was calculated from the obtained solution viscosity data.

(2) Moisture absorption rate The moisture absorption rate was calculated from the weight of the absolutely dry sample and the weight of the humidity control sample according to the following equation by conditioning the fiber sample in a constant temperature and humidity chamber adjusted to a predetermined condition for 24 hours.
Moisture absorption rate (%) = (weight of humidity control sample−weight of absolute dry sample) × 100 / weight of absolute dry sample

(3) Water absorption elongation rate / Hygroscopic elongation rate The fiber sample obtained was scraped, treated with boiling water for 30 minutes under no tension, then air-dried and conditioned at 20 ° C. and 65% RH (relative humidity), then contactless A yarn subjected to a dry heat treatment for 2 minutes in an environment of 160 ° C. under no tension is left in an environment of 20 ° C. and 65% RH (relative humidity) for 24 hours, and a load of 0.88 × 10 ⁻³ cN / dtex is applied thereto. The length of the yarn measured by multiplying was defined as “the length of the yarn when dried”. The yarn is then immersed in softened water adjusted to 20 ° C. for 1 minute, then pulled up from the water, and the moisture remaining on the fiber surface is sandwiched between filter papers air-dried at 20 ° C. and 65% RH (relative humidity). Place on the table and place a weight of 1.5 g / cm ² and leave for 2 seconds to wipe off excess moisture on the fiber surface. Then, after 10 seconds, apply a load of 0.88 × 10 ⁻³ cN / dtex. The length measured in this manner was defined as “the length of the yarn when absorbing water”. And the water absorption elongation rate was computed by the following formula. All measurements were performed in an environment of 20 ° C. and 65% RH (relative humidity).
Water absorption elongation = (yarn length at water absorption−yarn length at drying) ÷ yarn length at drying × 100%

In the same manner as described above, the “yarn length during drying” was measured, and then the yarn thus measured was conditioned for 24 hours in a constant temperature and humidity chamber adjusted to 35 ° C. and 95% RH, and then the constant temperature and humidity chamber. Then, the length measured by applying a load of 0.88 × 10 ⁻³ cN / dtex was defined as “the length of the yarn at the time of moisture absorption”, and the moisture absorption elongation rate was calculated by the following formula.
Hygroscopic elongation = (yarn length when absorbing moisture−yarn length when drying) ÷ yarn length when drying × 100%

(4) Sticky feeling, feeling of squeezing Elastic fiber is made into 132 k / m ² knit using a cylinder knitting machine, and this is put on the elbows and knees of 5 people who choose arbitrarily, and I spend a day, sticky feeling, feeling of squeezing Evaluated. The results are shown as sticky feeling, less sensation of feeling (small) and large (large), respectively.

(5) Hygroscopic durability Fabrics knitted with fibers were prepared and used as samples. Washing A household washing machine was used, and attack (manufactured by Kao Corporation) was used as a detergent, and the following steps (a) to (c) were repeated 100 times (referred to as L100).
(A) Wash with a 2 g / L detergent at a bath ratio of 1:30 at 40 ° C. for 10 minutes.
(B) After dehydration, rinse with water at a bath ratio of 1:30 at room temperature for 2 minutes. Repeat this twice.
(C) Air-dry after dehydration.
The obtained sample was conditioned for 24 hours in a constant temperature and humidity chamber adjusted to a predetermined condition, the moisture absorption rate was determined by the above method, and the retention rate was determined by comparing with the moisture absorption rate before washing.
Moisture absorption durability (moisture absorption rate,%) = [moisture absorption rate after washing] / [moisture absorption rate before washing] × 100

[Example 1]
100 parts by weight of dimethyl terephthalate, 23 parts by weight of a 40% by weight ethylene glycol solution of sodium 3,5-bis (β-hydroxyethoxycarbonyl) benzenesulfonate (5.0 mol% based on the total acid components), ) 113.4 parts by weight (number average molecular weight 2000, n = about 43), 73.5 parts by weight of 1,4-butanediol (1.4 mole times the total acid component) and tetra as a catalyst. 0.4 part by weight of butyl titanate was charged into a reaction vessel, and transesterification was performed at an internal temperature of 200 ° C. When about 80 mol% of the theoretical amount of methanol was distilled, 0.4 parts by weight of the hindered phenol compound (10) described above was added, and then a polycondensation reaction was started by raising the temperature and reducing the pressure. The polycondensation reaction is set to 4.0 kPa (30 mmHg) over about 30 minutes, then to 0.40 kPa (3 mmHg) over 30 minutes, and then the reaction is carried out for 200 minutes at an internal temperature of 250 ° C. under a vacuum of 0.27 kPa (1 mmHg). At that time, 1 part by weight of the following hindered phenol compound (following formula (10), n = 2) and 2 parts by weight of the following hindered amine compound (following formula (11)) were added, and then for another 20 minutes. The reaction was carried out at 250 ° C. for 20 minutes under a vacuum of 0.27 kPa (1 mmHg) or less. The intrinsic viscosity of the produced polyether ester elastomer is 0.90 dL / g. Polybutylene terephthalate component, etc. (hard segment) / weight of dihydroxy compound represented by the following formula (9) and polyoxyethylene glycol (soft segment) The ratio was 50/50.

The obtained polyetherester elastomer was melted at 230 ° C. and extruded from the spinneret at a discharge rate of 3.05 g / min. At this time, 9 cm was kept from directly under the base. An oil agent composed of 100% polydimethylsiloxane having a viscosity of 1 × 10 ⁻⁵ m ² / s at 30 ° C. at a position 3 m below the die is applied to the molten polymer by 3.0% by weight based on the fiber weight. The film was taken up at 510 m / min and further taken up at 750 m (winding draft 1.47) to obtain a polyether ester elastic fiber having 44 dtex / filament. The results are shown in Table 1.

Next, the polyester elastic fiber was knit having a basis weight of 132 g / m ² using a cylindrical knitting machine. After leaving this knit in an environment of 20 ° C. and 65% RH (relative humidity) for 24 hours, and further immersing it in 20 ° C. softened water for 1 minute, taking it out of the water and sandwiching the moisture adhering to the knit surface with filter paper The opening of each knit was observed after being removed by. As a result, it was confirmed that the knit opening was increased after being immersed in softened water. In Example 2 and later, the opening during water absorption was observed using the obtained knit by the same operation.

[Example 2]
An elastic fiber having an intrinsic viscosity of 0.91 dL / g was obtained in the same manner as in Example 1 except that the number average molecular weight of the dihydroxy compound represented by the above formula (9) was changed to 3000 (n = about 65). Obtained. The results are shown in Table 1.

[Example 3]
The addition amount of the dihydroxy compound represented by the above formula (9) (number average molecular weight 2000, n = about 43) as a soft segment is 56.7 parts by weight, and polyoxyethylene glycol (number average molecular weight is 4000) 56.7. It carried out similarly to Example 1 except having mixed and used the weight part. The results are shown in Table 1.

[Examples 4 and 5]
The copolymerization amount ratio of the dihydroxy compound represented by the above formula (9) (number average molecular weight 2000, n = about 43) was changed so that the hard segment / soft segment weight ratio was 60/40 or 40/60. Except for this, the same procedure as in Example 1 was performed. The results are shown in Table 1.

[Examples 6 and 7]
The copolymerization amount of 5-Na sulfoisophthalic acid dihydroxyethyl ester (same as sodium 3,5-di (β-hydroxyethoxycarbonyl) benzenesulfonate) was adjusted to 2. The same procedure as in Example 1 was performed except that the content was changed to 0 mol% or 15.0 mol%. The results are shown in Table 1.

[Comparative Example 1]
The same procedure as in Example 1 was conducted except that the polymerization reaction time was terminated when the intrinsic viscosity of the obtained polyether ester elastomer reached 0.58 dL / g. The results are shown in Table 1.

[Comparative Examples 2 and 3]
The copolymerization amount ratio of the dihydroxy compound represented by the above formula (9) (number average molecular weight 2000, n = about 43) was changed so that the hard segment / soft segment weight ratio was 80/20 or 20/80. Except for this, the same procedure as in Example 1 was performed. The results are shown in Table 1.

[Comparative Example 4]
The copolymerization amount of 5-Na sulfoisophthalic acid dihydroxyethyl ester (same as 3,5-di (β-hydroxyethoxycarbonyl) benzenesulfonic acid sodium salt) is 25 mol with respect to the total acid components constituting the polyether ester elastomer. % The same procedure as in Example 1 was performed except that the percentage was changed. The results are shown in Table 1.

  The polyether ester elastomer (copolyester) of the present invention has good moisture absorption / release properties, and reversibly expands / contracts due to water absorption / release water. Can be obtained, and a fabric excellent in comfort can be obtained. For this reason, the said polyester elastic fiber is used as clothing, and especially the performance which is excellent in uses, such as sports clothing, an inner, lining, stockings, and socks, is exhibited. Moreover, since it is polyester, chemical recycling is possible and it can be expected that it is excellent in recyclability.

Claims (3)

A dihydroxy compound component represented by the following general formula (1) is copolymerized with the polybutylene terephthalate component, or a dihydroxy compound component and a polyoxyethylene glycol component represented by the following general formula (1) are copolymerized, and the following general formula It is a copolyester having an intrinsic viscosity of 0.6 dL / g or more obtained by copolymerizing the organic sulfonic acid metal salt component represented by the formula (2),
The copolymerization rate of the organic sulfonic acid metal salt component represented by the following general formula (2) is 0.1 to 20.0 mol% based on the acid component constituting the copolymer polyester, and the polybutylene terephthalate component and The total weight ratio of the organic sulfonic acid metal salt component represented by the general formula (2) and the total of the dihydroxy compound component and the polyoxyethylene glycol component represented by the following general formula (1) is 30:70 to 70: 30 is a copolyester.

[In the above formula, R represents a hydrocarbon group having 1 to 18 carbon atoms, and n represents a number of 20 to 200. ]

[In the above formula, R ₁ represents an aromatic hydrocarbon group or an aliphatic hydrocarbon group, X ₁ represents an ester-forming functional group, and X ₂ represents an ester-forming functional group or a hydrogen atom that is the same as or different from X _1. , M ₁ is an alkali metal or an alkaline earth metal, j represents 1 when M ₁ is an alkali metal, and j represents 2 when M ₂ is an alkaline earth metal. ] The copolymer polyester according to claim 1, wherein the organic sulfonic acid metal salt component is a compound represented by the following general formula (3).

[In the above formula, R ₂ represents an aromatic hydrocarbon group or an aliphatic hydrocarbon group, and M ₂ represents an alkali metal. ]   A polyester obtained by spinning the copolymerized polyester according to claim 1 or 2 at 35 ° C and 95% RH, having a moisture absorption rate of 5.0% or more and a water absorption elongation rate of 10.0% or more. fiber.