JP4307179B2 - Method for producing core-sheath type polyester composite fiber and woven / knitted fabric - Google Patents

Description

  The present invention relates to a core-sheath type polyester composite fiber and a woven or knitted fabric having both excellent water absorption and permeability.

  Conventionally, polyester fibers have been widely used in various applications because they have many excellent properties. The required properties differ depending on the application. For example, in applications such as inner garments and sports garments, it is required to satisfy both excellent water absorption and permeability.

  However, since polyester fiber is hydrophobic, it is usually insufficient in terms of water absorption and moisture absorption.

  As a countermeasure, Patent Document 1 proposes forming micropores by subjecting polyester fibers made of polyester containing a micropore-forming agent to an alkali reduction treatment. According to such a method, although excellent water absorption can be obtained, it cannot be said that the permeation resistance is sufficient.

On the other hand, in patent document 2, a core part is formed with polyester containing 1.0% by weight or more of a matting agent, and a sheath part is formed with polyester containing a metal-containing phosphorus compound and an alkaline earth metal compound. There has been proposed a composite fiber having fine pores formed by subjecting to an alkali weight reduction process. In such a composite fiber, although a large amount of matting agent is contained in the core, the permeability is improved, but it is still insufficient. Also, the water absorption was not satisfactory.
Japanese Patent Publication No.61-31233 JP-A 62-57920

  This invention is made | formed in view of said background, The objective is to provide the core-sheath-type polyester composite fiber and woven / knitted fabric which have the outstanding water absorption and permeation resistance simultaneously.

As a result of intensive studies to achieve the above object, the present inventors have found that in the core-sheath type composite fiber,
By forming a core with polyester containing a specific amount of matting agent and making specific micropores in the sheath, the water absorption effect by micropores, the diffuse reflection effect of light, and the light scattering effect by matting agent are combined, The present inventors have found that an excellent water absorption effect and a permeation-proof effect can be obtained at the same time, and have further intensively studied to complete the present invention.

Thus, according to the present invention, “ polyester A containing 5% by weight or more of a matting agent for the core portion is used, and on the other hand, the matting agent is substantially free of the matting agent and sodium carbomethoxybenzenesulfonate”. Sodium 5-carboxylate, sodium 3-carbomethoxybenzenesulfonate-5 potassium carboxylate, potassium 3-carbomethoxybenzenesulfonate-5 potassium carboxylate, sodium 3-carboxybenzenesulfonate-5-carboxylate sodium , Melt spinning using polyester B containing any sulfonic acid metal salt selected from the group consisting of sodium 3-hydroxyethoxycarbonylbenzenesulfonate-5-1 / 2 magnesium carboxylate, and then an aqueous solution of an alkali compound By adding the additive in polyester B Elution by weight% or more has fine pores that simultaneously satisfy the following requirements (1) and (2), and the ratio A: B of the core area A to the sheath area B is 35: A method for producing a core-sheath type polyester composite fiber characterized by producing a core-sheath type polyester composite fiber in the range of 65-80: 20 is provided.
(1) The width D of the fine holes is 0.001 μm or more.
(2) The ratio L / D between the length L and the width D of the fine holes is 3 or more.

Further, according to the present invention, there is provided “a woven or knitted fabric comprising the core-sheath polyester composite fiber obtained by the above-described method for producing a core-sheath polyester composite fiber”.

  ADVANTAGE OF THE INVENTION According to this invention, the core-sheath-type polyester composite fiber and woven / knitted fabric which have the outstanding water absorption and permeation resistance are obtained.

Hereinafter, embodiments of the present invention will be described in detail.
First, the polyester referred to in the present invention has terephthalic acid as the main acid component and at least one glycol, preferably one alkylene glycol selected from ethylene glycol, trimethylene glycol and tetramethylene glycol as the main glycol component. The main target is polyester.

  Further, a polyester in which a part of the terephthalic acid component is replaced with another bifunctional carboxylic acid component may be used, and / or a part of the glycol component is replaced with the above-mentioned glycol other than the main component or another diol component. Polyester may be used.

  Here, examples of the bifunctional carboxylic acid other than terephthalic acid used include isophthalic acid, naphthalene dicarboxylic acid, diphenyl carboxylic acid, diphenoxyethanedicarboxylic acid, β-hydroxyethoxybenzoic acid, P-oxybenzoic acid, 5 -Aromatic, aliphatic, and alicyclic bifunctional carboxylic acids such as sodium sulfoisophthalic acid, adipic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid. Examples of diol compounds other than the above glycols include aliphatic, alicyclic and aromatic diol compounds such as cyclohexane-1,4-dimethanol, neopentyl glycol, bisphenol A and bisphenol S, and polyoxyalkylene glycol. I can give you. Such polyester can be synthesized by a known method.

  The polyester A in the present invention contains at least 5.0% by weight of a matting agent based on the weight of the polyester. When the content of the matting agent is less than 5.0% by weight, a sufficient anti-slipping effect cannot be obtained. The matting agent may be a conventionally known one such as titanium oxide. Such polyester A may contain optional additives such as an antioxidant, an ultraviolet absorber, a heat stabilizer, a flame retardant, a colorant, and inert fine particles as long as the object of the present invention is not impaired. .

On the other hand, polyester B does not substantially contain a matting agent and has a large number of fine pores that simultaneously satisfy the following requirements (1) and (2).
(1) The width D of the fine holes is 0.001 μm or more.
(2) The ratio L / D between the length L and the width D of the fine holes is 3 or more.

  Here, the fact that it does not contain a matting agent substantially means that it does not contain a matting agent that does not adversely affect water absorption, and usually contains 0.3% by weight or less of a matting agent. There is no problem. Furthermore, the polyester B may contain any additive such as an antioxidant, an ultraviolet absorber, a heat stabilizer, a flame retardant, a colorant, and inert fine particles as long as the object of the present invention is not impaired. Good.

  The above-mentioned micropores have an average value of n number of 10 selected arbitrarily, the width D is 0.001 μm or more (preferably 0.01 to 3 μm, particularly preferably 0.02 to 2 μm), and the length of the micropores The ratio L / D between L and width D needs to be 3 or more (preferably 5 to 50). If the width D of the micropores is less than 0.001 μm, sufficient water absorption and light irregular reflection effect cannot be obtained, which is not preferable. On the other hand, if the width D exceeds 3 μm, the tensile strength of the fiber may be lowered. Further, if the ratio L / D between the length L and the width D of the micropores is less than 3, it is not preferable because a sufficient water absorption effect cannot be obtained. On the other hand, if L / D exceeds 50, the tensile strength of the fiber may decrease. In addition, about the depth of a micropore, although it does not specifically limit, About 0.5 to 10 times the width | variety D is suitable, and it may have reached the core part.

  In the core-sheath type polyester composite fiber of the present invention, polyester A containing 5% by weight or more of a matting agent is disposed in the core portion, and polyester B substantially not including the matting agent and having the fine pores is disposed in the sheath portion. Is done. Here, the core-sheath structure may be a single-core type or a multi-core type. Furthermore, it may be a single-core type with a positive core (concentric) or a single-core type with an eccentricity (eccentricity). Further, even if a part of the core is exposed on the surface, it is acceptable as long as it is within the range in which the water absorption and permeation resistance, which are the main objects of the present invention, are not impaired. Among these, a positive single core type is preferable in consideration of stability and reproducibility in mass production.

  The combined ratio of the polyester A and the polyester B is such that the ratio A: B of the area A of the core part and the area B of the sheath part is in the range of 35:65 to 80:20 in order to achieve both water absorption and permeability. There is a need. Here, if the area A of the core part is smaller than the above range, sufficient permeation resistance cannot be obtained, which is not preferable. On the contrary, when the area B of the sheath is smaller than the above range, it is not preferable because sufficient water absorption cannot be obtained. In addition, when a core part is a multi-core type, the total cross-sectional area of a core part cross section is the sum total of the cross-sectional areas of each core part.

  In the core-sheath polyester composite fiber of the present invention, the cross-sectional shape of the composite fiber and the cross-sectional shape of the core part are selected from arbitrary shapes such as a circle, a triangle, a square, a flat shape, and a hollow shape. Moreover, the cross-sectional shape of the composite fiber and the cross-sectional shape of the core part may be the same or different. Furthermore, the form of the fiber is not particularly limited, and may be a long fiber or a short fiber. The total fineness, single yarn fineness, and number of filaments of the composite fiber are not particularly limited, but are preferably in the range of 30 to 300 dtex, 0.6 to 10 dtex, and 10 to 50, respectively, in terms of texture and productivity.

  As a method for producing the core-sheath type polyester composite fiber of the present invention, polyester A containing 5.0% by weight or more of a matting agent and polyester B containing a sulfonic acid metal salt represented by the following chemical formula, for example, The melt is spun using a known core-sheath type composite spinning apparatus so that the former is located in the core and the latter is located in the sheath, and then the additive in the polyester B is added by 2% by weight or more with an aqueous solution of an alkali compound. The method of elution and forming many micropores on the atmosphere side surface of the sheath and the vicinity thereof can be mentioned.

式中、ＭおよびＭ´は金属であり、アルカリ土類金属、マンガン、コバルト、亜鉛が好ましく、ＭおよびＭ´は同一でも異なってもよい。Ｒは水素原子またはエステル形成性官能基であり、ｎは１または２を示す。

In the formula, M and M ′ are metals, and alkaline earth metals, manganese, cobalt, and zinc are preferable, and M and M ′ may be the same or different. R represents a hydrogen atom or an ester-forming functional group, and n represents 1 or 2.

  As such a sulfonic acid metal salt, for example, those described in JP-B-61-31231 are preferably used. Specifically, sodium 3-carbomethoxybenzene sodium sulfonate-5-carboxylate, 3-carbomethoxybenzene Sodium sulfonate-5-carboxylate, potassium 3-carbomethoxybenzenesulfonate-5-carboxylate, sodium 3-carboxybenzenesulfonate-5-carboxylate, sodium 3-hydroxyethoxycarbonylbenzenesulfonate-5 -1/2 magnesium carboxylate, sodium benzenesulfonate-3,5-dicarboxylate 1/2, etc. can be mentioned. The said sulfonic acid metal salt may be used individually by 1 type, or may use 2 or more types together.

  The sulfonic acid metal salt may be added to the polyester at any stage before the polyester is melt-spun. For example, it may be added to the polyester raw material or added during the synthesis of the polyester. Also, if the amount of the above compound added is small, the water-absorbing property of the core-sheath polyester composite fiber finally obtained is lowered, while if it is large, troubles are likely to occur during spinning. The range of 0.5 to 5 mol% is suitable.

  The treatment with the alkaline compound aqueous solution for forming a large number of micropores in the polyester B can be carried out at any stage after the melt composite spinning, and after processing such as heat processing, further after forming the fabric You may go. Examples of the alkali compound used here include sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, sodium carbonate, potassium carbonate and the like. Of these, sodium hydroxide and potassium hydroxide are particularly preferable. The concentration of such an alkali compound varies depending on the type of alkali compound, processing conditions, etc., but is usually preferably in the range of 0.01 to 40% by weight, particularly preferably in the range of 0.1 to 30% by weight. The treatment temperature is preferably in the range of room temperature to 100 ° C., and the treatment time is usually in the range of 1 minute to 4 hours. Further, the amount of elution and removal by the treatment of the aqueous solution of the alkali compound is preferably 2% by weight or more (more preferably 5 to 40% by weight) with respect to the fiber weight.

  Next, according to the present invention, there is provided a woven or knitted fabric comprising the core-sheath type polyester composite fiber (preferably 30% by weight or more, particularly preferably 100% by weight). Here, the core-sheath type polyester composite fiber is a single yarn or a composite yarn with other fibers (polyester fiber, nylon fiber, natural fiber, etc.), and then false twisted crimped yarn as necessary. In addition, the yarn is a yarn such as a spun yarn or a twisted yarn, and is in the form of a fabric such as a woven or knitted fabric or a nonwoven fabric which is a known fiber assembly. As the woven structure of the woven fabric, plain weave, twill weave, satin weave, or a changed structure thereof is preferably used. As the knitted fabric, any of circular knitted fabric such as smooth fabric, weft knitted fabric, warp knitted fabric and the like can be used.

  Furthermore, by subjecting the woven or knitted fabric to the alkali weight reduction process, the fine holes as described above can be formed in the sheath. Such a woven or knitted fabric may be subjected to a conventional dyeing finishing process. In addition, various processes that provide functions such as conventional water-repellent processing, brushed processing, ultraviolet shielding or antibacterial agents, deodorants, insect repellents, phosphorescent agents, retroreflective agents, and negative ion generators are additionally applied. Also good.

  In the core-sheath type polyester composite fiber and woven or knitted fabric obtained by the present invention, since the above-mentioned micropores are formed in the sheath part of the core-sheath type polyester composite fiber, water absorption superior in capillarity of such micropores Is expressed. At the same time, the micropores have irregularities on the fiber surface, so that light is irregularly reflected and the permeation resistance is improved. Furthermore, since a specific amount of matting agent is contained in the core portion of the core-sheath type polyester composite fiber, the light-shielding effect is further improved by the light scattering effect of the matting agent.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited at all by these. In addition, each physical property in an Example is measured with the following method.
(1) Intrinsic viscosity Measured with an orthochlorophenol solution at 35 ° C.
(2) Water absorption rate After a sample (30 cm × 30 cm) obtained by drying the fabric is immersed in water for 30 minutes or more, it is dehydrated with a dehydrator of a household electric washing machine for 5 minutes. ) Moreover, the mass Y (g) of the sample in the absolutely dry state prescribed | regulated separately to JISL0105-1998 is calculated | required. And a water absorption is calculated by the following formula. This is repeated 5 times, and the average value is defined as the water absorption rate (%).
Water absorption rate (%) = ((XY) / Y) × 100
(3) Permeability Permeability (%) = ((reflectance on standard black backing plate (reflectance 6%)) / (reflectance on standard white backing plate (reflectance 91%)) )) X 100
As for the numerical value of the permeation resistance, it indicates that the black backing plate and the white backing plate have a perfect permeation resistance of 100% if the reflectance when backing is equal, If the reflectance when backed by a black backing plate is 0%, the permeation resistance is 0%, indicating a complete transparent body. In addition, it measured by n number 5, and calculated | required the average value.
(4) Microporous size The fiber surface was measured by taking an electron micrograph of 3000 times. In addition, it measured arbitrarily by n number 10 and calculated | required the average value.

[Example 1]
In a normal polymerization reaction step of polyethylene terephthalate, 1.3 mol% of sodium 3-carbomethoxybenzenesulfonate-5-carboxylate (micropore forming agent) with respect to dimethyl terephthalate was added, and an intrinsic viscosity of 0. A polyester B having a softening point of 258 ° C. was obtained.

  On the other hand, a normal polyethylene terephthalate containing 10% by weight of titanium oxide and having an intrinsic viscosity of 0.60 and a softening point of 257 ° C. was designated as polyester A.

  Then, using polyester A and polyester B, melt spinning at 280 ° C. from an ordinary core / sheath composite spinning apparatus, taking up at a speed of 3000 m / min, winding without stretching, and 140 dtex / 36 fil core-sheath type A polyester composite fiber (composite area ratio, polyester A: polyester B = 45: 55) was obtained. The composite fiber was subjected to normal false twist crimping using a triaxial friction type disk type false twisting apparatus at a processing speed of 640 m / min and a heater temperature of 200 ° C.

  Then, a taffeta woven fabric was woven using the core-sheath type polyester composite fiber subjected to false twist crimping for warp and weft. The fabric was then relaxed with boiling water for 20 minutes using a conventional liquid dyeing machine, followed by preset processing according to a conventional method, and then subjected to alkali weight reduction at a boiling temperature with a 3.5 wt% aqueous sodium hydroxide solution. The treatment (weight loss rate 20%) was performed. Further, normal staining and final set processing were performed.

  The resulting fabric had a permeability of 98.3% and a water absorption of 76%. Further, in the core-sheath type polyester composite fiber constituting the woven fabric, a large number of micropores are arranged on the fiber surface and in the vicinity thereof, and the size of the micropores is measured by n number of 10, and the width is The distribution was 0.01 μm to 2 μm, and the average value was 1.2 μm. Moreover, the length was distributed by 0.3 micrometer-12 micrometers, and the average value was 8 micrometers.

[Example 2]
Example 1 except that the composite area ratio of the core part (polyester A) and the sheath part (polyester B) of the core-sheath type polyester composite fiber is changed to polyester A: polyester B = 70: 30. Weaving, relaxation treatment, preset treatment, alkali weight loss treatment, dyeing, and final set treatment were performed in the same manner as above. The resulting fabric had a permeability of 99.0% and a water absorption of 68%.

[Example 3]
Example 1 except that the composite area ratio of the core part (polyester A) and the sheath part (polyester B) of the core-sheath type polyester composite fiber is changed to polyester A: polyester B = 40: 60. Weaving, relaxation treatment, preset treatment, alkali weight loss treatment, dyeing, and final set treatment were performed in the same manner as above. The resulting fabric had a permeability of 98.2% and a water absorption of 79%.

[Example 4]
Example 1 except that the composite area ratio of the core part (polyester A) and the sheath part (polyester B) of the core-sheath type polyester composite fiber is changed to polyester A: polyester B = 63: 37 in example 1. Weaving, relaxation treatment, preset treatment, alkali weight loss treatment, dyeing, and final set treatment were performed in the same manner as above. The obtained fabric had a permeability of 98.8% and a water absorption of 70%.

[Comparative Example 1]
Example 1 except that the composite area ratio of the core part (polyester A) and the sheath part (polyester B) of the core-sheath type polyester composite fiber is changed to polyester A: polyester B = 15: 85 in example 1. Weaving, relaxation treatment, preset treatment, alkali weight loss treatment, dyeing, and final set treatment were performed in the same manner as above. The resulting fabric had a moisture permeability of 65.8% and a water absorption of 80%.

[Comparative Example 2]
In Example 1, except that the composite area ratio of the core part (polyester A) and the sheath part (polyester B) of the core-sheath type polyester composite fiber is changed to polyester A: polyester B = 24: 76. Weaving, relaxation treatment, preset treatment, alkali weight loss treatment, dyeing, and final set treatment were performed in the same manner as above. The resulting fabric had a permeability of 79.0% and a water absorption of 79%.

[Comparative Example 3]
In Example 1, in a normal polymerization reaction step of polyethylene terephthalate, 0.7 mol% of phosphoric acid diester calcium salt with respect to dimethyl terephthalate and 0.9 times mol of calcium acetate with respect to phosphoric acid diester calcium salt Was added, and weaving / relaxation treatment / preset treatment / alkaline weight loss treatment / dyeing / final set treatment were performed in the same manner as in Example 1 except that polyester B having an intrinsic viscosity of 0.64 and a softening point of 259 ° C. was used. The resulting fabric had a permeability of 98.3% and a water absorption of 52%. Further, in the core-sheath polyester composite fiber constituting the woven fabric, a large number of micropores are arranged in the fiber axis direction on the fiber surface and in the vicinity thereof. When the size of the micropores was measured with an n number of 10, the average width was 0.4 μm, and the average length in the fiber axis direction was 0.8 μm.

[Comparative Example 4]
In Example 1, except that the content of titanium oxide contained in polyester A is changed to 1% by weight, weaving, relaxing treatment, preset treatment, alkali weight loss treatment, dyeing, and final set treatment are performed in the same manner as in Example 1. went. The resulting fabric had a permeability of 68.9% and a water absorption of 76%.

[Comparative Example 5]
In Example 1, weaving, relaxation treatment, preset treatment, alkali weight loss treatment, dyeing, and final set treatment were performed in the same manner as in Example 1 except that polyester B containing no micropore forming agent was used. The resulting fabric had a permeability of 82% and a water absorption of 24%.

  ADVANTAGE OF THE INVENTION According to this invention, the core-sheath-type polyester composite fiber and woven / knitted fabric which have the outstanding water absorption and permeation-proof property simultaneously are provided. Such a woven or knitted fabric is extremely suitable for applications such as inner garments and sports garments.

Claims (2)

Polyester A containing 5% by weight or more of a matting agent for the core part is used, and on the other hand, it is substantially free of the matting agent for the sheath part, and sodium 3-carbomethoxybenzenesulfonate-5-carboxylate, Sodium 3-carbomethoxybenzenesulfonate-5-carboxylate, potassium 3-carbomethoxybenzenesulfonate-5-carboxylate, sodium 3-carboxybenzenesulfonate-5-carboxylate, 3-hydroxyethoxycarbonylbenzene Melt spinning using polyester B containing any sulfonic acid metal salt selected from the group consisting of sodium sulfonate-5-carboxylate 1/2 magnesium, then adding in aqueous solution of alkali compound in polyester B Elute more than 2% by weight Therefore, it has the micropore which satisfies the following requirements (1) and (2) simultaneously, and the ratio A: B of the area A of the core part and the area B of the sheath part is 35:65 to 80:20. The manufacturing method of the core-sheath-type polyester composite fiber characterized by manufacturing the core-sheath-type polyester composite fiber which is a range.
(1) The width D of the fine holes is 0.001 μm or more.
(2) The ratio L / D between the length L and the width D of the fine holes is 3 or more. A woven or knitted fabric comprising the core-sheath polyester composite fiber obtained by the method for producing a core-sheath polyester composite fiber according to claim 1.