JP6973079B2 - Sea-island type composite fiber, false plying and fiber structure with excellent hygroscopicity - Google Patents

Description

The present invention relates to a sea-island type composite fiber in which the island component is a polymer having hygroscopicity and is excellent in hygroscopicity. More specifically, in hot water treatment such as dyeing, cracking of the sea component due to volume swelling of the hygroscopic polymer of the island component is suppressed, so that dyeing spots are formed when the fiber structure such as woven fabric or knitted fabric is formed. Since the generation of fluff and fluff is small, the quality is excellent, and the elution of the hygroscopic polymer is suppressed, the hygroscopicity is excellent even after hot water treatment such as dyeing, and further, when the sea component is polyester. The present invention relates to a sea-island type composite fiber that has the original dry feeling of polyester fiber and can be suitably used for clothing applications.

Polyester fibers are used in a wide range of applications because they are inexpensive and have excellent mechanical properties and a dry feeling. However, since it has poor hygroscopicity, it has problems to be solved from the viewpoint of wearing comfort, such as the generation of stuffiness when the humidity is high in the summer and the generation of static electricity when the humidity is low in the winter.

In order to improve the above-mentioned drawbacks, various proposals have been made so far on a method for imparting hygroscopicity to polyester fibers. As a general method for imparting hygroscopicity, copolymerization of a hydrophilic compound with polyester, addition of a hydrophilic compound, and the like can be mentioned, and polyethylene glycol can be mentioned as an example of the hydrophilic compound.

For example, Patent Document 1 proposes a fiber in which a polyester copolymerized with polyethylene glycol is used as a hygroscopic polymer with respect to the polyester. In this proposal, the hygroscopic polymer is fiberized by itself to impart hygroscopicity to the polyester fiber.

Patent Document 2 proposes a core-sheath type composite fiber in which polyethylene glycol is copolymerized on the core and polyethylene terephthalate is arranged on the sheath. In this proposal, a hygroscopic polymer is placed on the core to impart hygroscopicity to the polyester fiber.

Patent Document 3 proposes a polyester in which polyethylene glycol is copolymerized on an island and a sea-island type composite fiber in which polyethylene terephthalate is arranged on the sea. In this proposal, a hygroscopic polymer is placed on the island to impart hygroscopicity to the polyester fiber.

Japanese Unexamined Patent Publication No. 2006-104379 Japanese Unexamined Patent Publication No. 2001-172374 Japanese Unexamined Patent Publication No. 8-198954

However, in the method described in Patent Document 1, the hygroscopic polymer is exposed on the entire fiber surface, and polyethylene glycol, which is a copolymerization component of the hygroscopic polymer, is eluted during hot water treatment such as dyeing, and after hot water treatment. There was a problem that the hygroscopicity was lowered.

The method described in Patent Document 2 has a problem that the sheath component is cracked due to the volume swelling of the hygroscopic polymer of the core component during hot water treatment such as dyeing, and the quality is deteriorated due to the generation of dyeing spots and fluff. .. Further, there is a problem that the hygroscopic polymer of the core component is eluted from the portion where the sheath component is cracked, and the hygroscopicity is lowered after the hot water treatment.

In the method described in Patent Document 3, since the thickness of the sea component of the outermost layer with respect to the fiber diameter is small in the cross section of the fiber, the hygroscopic polymer of the island component expands in volume during hot water treatment such as dyeing, and the sea component. There was a problem that the quality was deteriorated due to the generation of dyeing spots and fluff, similar to the method described in Patent Document 2. Further, there is a problem that the hygroscopic polymer of the island component is eluted from the portion where the sea component is cracked, and the hygroscopic property is lowered after the hot water treatment.

The problem of the present invention is to solve the above-mentioned problems of the prior art, to reduce the occurrence of dyeing spots and fluff when the fiber structure is made of a woven fabric or knitted fabric, to have excellent quality, and after hot water treatment such as dyeing. Further, when the sea component is polyester, it also has the original dry feeling of polyester fiber, and it is an object of the present invention to provide a sea-island type composite fiber that can be suitably adopted for clothing applications.

The above-mentioned subject of the present invention is that the sea component is polyester, the island component is a polymer having hygroscopicity, and the polymer having hygroscopicity is a polyester composed of an aromatic dicarboxylic acid and an aliphatic diol, and a polyether is co-used. It is a polyether ester as a polymerization component, and has a ratio (T / R) of the outermost layer thickness T and the fiber diameter R in the cross section of the fiber of 0.05 to 0.25, and the difference in moisture absorption rate after hot water treatment (difference in moisture absorption rate (T / R). It can be solved by a sea-island type composite fiber characterized by having a ΔMR) of 2.0 to 10.0%. The outermost layer thickness is the difference between the radius of the fiber and the radius of the circumscribed circle connecting the vertices of the island components arranged on the outermost circumference, and represents the thickness of the sea component existing in the outermost layer.

Further, it is preferable that the outermost layer thickness T is 500 to 3000 nm, and the diameter r of the island component in the fiber cross section is 10 to 5000 nm.

Furthermore, in the fiber cross section, the island components are arranged around 2 to 100 circumferences, and the ratio of the diameter r1 of the island component arranged so as to pass through the center of the fiber cross section and the diameter r2 of the other island components ( r1 / r2) is 1.1 to 10.0, the shape of the center side of the fiber cross section is non-circular in the island components arranged on the outermost circumference, and the composite ratio of the sea component / island component ( It can be preferably adopted that the weight ratio) is 50/50 to 90/10.

Polymers having hygroscopicity of the island component is Ru Oh polyether ester le containing polyether as a copolymerization component. Further, the polyether is preferably at least one polyether selected from the group consisting of polyethylene glycol, polypropylene glycol and polybutylene glycol, and the number average molecular weight of the polyether is 2000 to 30,000 g / mol. It can be preferably adopted that the copolymerization rate of ether is 10 to 60% by weight.

The polyether ester as a main component an aromatic dicarboxylic acid and an aliphatic diol, shall be the polyether copolymer component. It is preferable that the alkylene oxide adduct copolymer component of bisphenols represented by Po Rieteru the following general formula (1), it is preferred aliphatic diol is 1,4-butanediol.

(However, m and n are integers of 2 to 20, and m + n is 4 to 30).

Furthermore, it is preferable that the sea component of the sea-island type composite fiber is a cationic dyeable polyester.

The false twisted yarn of the present invention is made by twisting two or more sea-island type composite fibers, and is suitable for a fiber structure characterized in that the sea-island type composite fiber and / or the false twisted yarn is used for at least a part thereof. Can be adopted.

According to the present invention, in hot water treatment such as dyeing, cracking of the sea component due to volume swelling of the hygroscopic polymer of the island component is suppressed, so that when the fiber structure such as a woven fabric or knitted fabric is formed, it is suppressed. Excellent quality with less dyeing spots and fluff. In addition, since the elution of the hygroscopic polymer is suppressed, it has excellent hygroscopicity even after hot water treatment such as dyeing, and when the sea component is polyester, it also has the original dry feeling of polyester fiber. Since the sea-island type composite fiber can be provided, it can be suitably used particularly for clothing applications.

1 (a) to 1 (m) are views showing an example of the cross-sectional shape of the sea-island type composite fiber of the present invention. FIG. 2 is an example of a sea island composite base used in the method for producing a sea island type composite fiber of the present invention, FIG. 2 (a) is a normal cross-sectional view of a main part constituting the sea island composite base, and FIG. 2 (b) is. A cross-sectional view of a part of the distribution plate, FIG. 2C is a cross-sectional view of the discharge plate. FIG. 3 is a part of an example of a distribution plate. FIG. 4 is an example of the distribution groove and distribution hole arrangement in the distribution plate.

The sea-island type composite fiber of the present invention is a polymer in which the island component has hygroscopicity, and the ratio (T / R) of the outermost layer thickness T to the fiber diameter R in the cross section of the fiber is 0.05 to 0.25. The difference in hygroscopicity (ΔMR) after hot water treatment is 2.0 to 10.0%. The outermost layer thickness is the difference between the radius of the fiber and the radius of the circumscribed circle connecting the vertices of the island components arranged on the outermost circumference, and represents the thickness of the sea component existing in the outermost layer.

In general, a hygroscopic polymer (hereinafter, may be simply referred to as a hygroscopic polymer) has a property of easily expanding in volume by hot water treatment such as dyeing and easily elution into hot water. There is. Therefore, when the hygroscopic polymer is fiberized by itself, there is a problem that the hygroscopic polymer is eluted by hot water treatment, and the eluted portion causes dyeing spots and fluff, resulting in deterioration of quality. Further, when the hygroscopic polymer is a polymer obtained by copolymerizing a hydrophilic copolymerization component, there is also a problem that the hydrophilic copolymerization component is eluted by the hot water treatment and the hygroscopicity is lowered after the hot water treatment. be.

On the other hand, in the core-sheath type composite fiber in which the hygroscopic polymer is arranged in the core, the hygroscopic polymer arranged in the core swells in volume by hot water treatment such as dyeing, and the stress is concentrated on the interface between the core component and the sheath component. , Cracking of the sheath component occurs. Due to the cracking of the sheath component, dyeing spots and fluff are generated, and there is a problem that the quality is deteriorated. Further, the hygroscopic polymer arranged in the core is eluted from the portion where the sheath component is cracked, which causes another problem that the hygroscopicity is lowered after the hot water treatment.

The sea-island type composite fiber in which the hygroscopic polymer is arranged on the island also has the same problems as the core-sheath type composite fiber. The conventional sea-island type composite fiber can be obtained by, for example, a conventionally known pipe-type sea-island composite base disclosed in Japanese Patent Application Laid-Open No. 2007-100243, but the thickness of the sea component of the outermost layer is about 150 nm. It is the limit. That is, since the thickness of the sea component in the outermost layer of the sea-island type composite fiber is very thin compared to the thickness of the sheath component of the core-sheath type composite fiber, the volume swelling of the hygroscopic polymer placed on the island by hot water treatment such as dyeing. As a result, the sea component is easily cracked. Dyeing spots and fluffing occur due to the cracking of the sea component, and the quality deteriorates. At the same time, the hygroscopic polymer placed on the island elutes from the cracked part of the sea component, and the hygroscopicity becomes high after hot water treatment. descend.

As a result of diligent studies in view of the above problems, the present inventors disperse the stress associated with volume swelling by dispersing the hygroscopic polymer, and specify the ratio (T / R) of the outermost layer thickness T and the fiber diameter R. For the first time, we succeeded in solving all of the above problems and obtaining a sea-island type composite fiber that exhibits high quality and high hygroscopicity even after hot water treatment.

The island component of the sea-island type composite fiber of the present invention is a polymer having hygroscopicity. In the present invention, the hygroscopic polymer is a polymer having a hygroscopicity difference (ΔMR) of 2.0 to 30.0%. The hygroscopicity difference (ΔMR) in the present invention refers to a value measured by the method described in Examples. When the ΔMR of the hygroscopic polymer is 2.0% or more, a sea-island type composite fiber having excellent hygroscopicity can be obtained by combining with a sea component. The ΔMR of the hygroscopic polymer is more preferably 5.0% or more, further preferably 7.0% or more, and particularly preferably 10.0% or more. On the other hand, when the ΔMR of the hygroscopic polymer is 30.0% or less, it is preferable because it has good process passability and handleability, and also has excellent durability in use after forming a sea-island type composite fiber.

Specific examples of the island component of the sea-island type composite fiber of the present invention, polyether esters, polyether amides, polyether ester amides, polyamides, thermoplastic cellulose derivatives, hygroscopic polymers, such as polyvinyl pyrrolidone, but Na or at even , A polyether ester containing a polyether as a copolymerization component, a polyether amide, and a polyether ester amide are preferable because they have excellent hygroscopicity. In particular, a polyether ester has excellent heat resistance, and the mechanical properties of the obtained sea-island type composite fiber and It is preferable because the color tone is good. Two or more of these hygroscopic polymers may be used in combination. Further, a blend of these hygroscopic polymers with polyester, polyamide, polyolefin or the like may be used as the hygroscopic polymer.

Specific examples of the polyether as a copolymerization component of the hygroscopic polymer include homopolymers such as polyethylene glycol, polypropylene glycol and polybutylene glycol, polyethylene glycol-polypropylene glycol copolymer, polyethylene glycol-polybutylene glycol copolymer and the like. Examples include, but are not limited to, the copolymers of. Of these, polyethylene glycol, polypropylene glycol, and polybutylene glycol are preferable because they are easy to handle during production and use, and polyethylene glycol is particularly preferable because they are excellent in hygroscopicity.

The number average molecular weight of the polyether is preferably 2000 to 30,000 g / mol. When the number average molecular weight of the polyether is 2000 g / mol or more, the hygroscopic polymer obtained by copolymerizing the polyether has high hygroscopicity, and the sea-island type composite fiber having excellent hygroscopicity when used as an island component. Is preferable because The number average molecular weight of the polyether is more preferably 3000 g / mol or more, and further preferably 5000 g / mol or more. On the other hand, when the number average molecular weight of the polyether is 30,000 g / mol or less, the polycondensation reactivity is high, unreacted polyethylene glycol can be reduced, and the island component to hot water during hot water treatment such as dyeing can be reduced. It is preferable because the elution of the hygroscopic polymer is suppressed and the hygroscopicity can be maintained even after the hot water treatment. The number average molecular weight of the polyether is more preferably 25,000 g / mol or less, and further preferably 20,000 g / mol or less.

The copolymerization rate of the polyether is preferably 10 to 60% by weight. When the copolymerization rate of the polyether is 10% by weight or more, the hygroscopic polymer obtained by copolymerizing the polyether has high hygroscopicity, and the sea-island type composite fiber having excellent hygroscopicity when used as an island component. Is preferable because The copolymerization rate of the polyether is more preferably 20% by weight or more, further preferably 30% by weight or more. On the other hand, if the copolymerization rate of the polyether is 60% by weight or less, unreacted polyethylene glycol can be reduced, and the elution of the hygroscopic polymer of the island component into hot water during hot water treatment such as dyeing is suppressed. Therefore, it is preferable because the hygroscopic property can be maintained even after the hot water treatment. The copolymerization ratio of the polyether is more preferably 55% by weight or less, further preferably 50% by weight or less.

From the viewpoint of heat resistance and mechanical properties, the polyether ester contains an aromatic dicarboxylic acid and an aliphatic diol as main constituents, and a polyether as a copolymerization component, or an aromatic dicarboxylic acid and an aliphatic diol. It is preferable that the main constituent is a copolymer and an alkylene oxide adduct of a bisphenol represented by the following general formula (1) as a copolymer.

(However, m and n are integers of 2 to 20, and m + n is 4 to 30).

Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, 5-sodium sulfoisophthalic acid, 5-lithium sulfoisophthalic acid, 5- (tetraalkyl) phosphonium sulfoisophthalic acid, and 4,4'-diphenyl. Examples thereof include, but are not limited to, dicarboxylic acids and 2,6-naphthalenedicarboxylic acids.

Specific examples of the aliphatic diol include, but are limited to, ethylene glycol, 1,3-propanediol, 1,4-butanediol, hexanediol, cyclohexanediol, diethylene glycol, hexamethylene glycol, neopentyl glycol and the like. Not done. Among them, ethylene glycol, propylene glycol, and 1,4-butanediol are preferable because they are easy to handle during production and use, and ethylene glycol can be preferably adopted from the viewpoint of heat resistance and mechanical properties. From the viewpoint of crystallinity, 1,4-butanediol can be preferably used.

When the polyether ester contains a polyether and an alkylene oxide adduct of bisphenols represented by the general formula (1) as a copolymerization component, the moldability of the polyether ester becomes good, and the obtained sea-island type composite is obtained. It is preferable because the mechanical properties of the fiber are high, the occurrence of fineness spots can be suppressed, there are few dyeing spots and fluff, and the quality is good.

The alkylene oxide adduct of bisphenols represented by the general formula (1) preferably has m + n of 4 to 30. When m + n is 4 or more, the moldability of the polyether ester is good, the occurrence of fineness spots on the obtained sea-island type composite fiber can be suppressed, there are few dyeing spots and fluff, and the quality is good, which is preferable. On the other hand, when m + n is 30 or less, the heat resistance and color tone of the polyether ester are good, and the mechanical properties and color tone of the obtained sea-island type composite fiber are good, which is preferable. m + n is more preferably 20 or less, further preferably 10 or less.

Specific examples of the alkylene oxide adduct of bisphenols represented by the general formula (1) include, but are not limited to, an ethylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol S. Among them, the ethylene oxide adduct of bisphenol A is preferable because it is easy to handle during production and use, and can be suitably adopted from the viewpoint of heat resistance and mechanical properties.

When the polyether and the alkylene oxide adduct of the bisphenol represented by the above general formula (1) are used as the copolymerization component, the copolymerization rate of the polyether is 10 to 45% by weight, and the alkylene oxide adduct of the bisphenol is used. The copolymerization rate of the above is preferably 10 to 30% by weight. When the copolymerization rate of the polyether is 10% by weight or more, the hygroscopic polymer obtained by copolymerizing the polyether has high hygroscopicity, and the sea-island type composite fiber having excellent hygroscopicity when used as an island component. Is preferable because The copolymerization ratio of the polyether is more preferably 20% by weight or more, further preferably 30% by weight or more. On the other hand, if the copolymerization rate of the polyether is 45% by weight or less, unreacted polyethylene glycol can be reduced, and the elution of the hygroscopic polymer of the island component into hot water during hot water treatment such as dyeing is suppressed. Therefore, it is preferable because the hygroscopic property can be maintained even after the hot water treatment. The copolymerization ratio of the polyether is more preferably 40% by weight or less, further preferably 35% by weight or less. Further, when the copolymerization rate of the alkylene oxide adduct of bisphenols is 10% by weight or more, the molding processability of the polyether ester becomes good, the occurrence of fineness spots on the obtained sea-island type composite fiber can be suppressed, and the dyeing spots can be suppressed. It is preferable because it has less fluff and fluff and has good quality. The copolymerization rate of the alkylene oxide adduct of bisphenols is more preferably 12% by weight or more, further preferably 14% by weight or more. On the other hand, when the copolymerization rate of the alkylene oxide adduct of bisphenols is 30% by weight or less, the heat resistance and color tone of the polyether ester are good, and the mechanical properties and color tone of the obtained sea-island type composite fiber are good. It is preferable because there is. The copolymerization rate of the alkylene oxide adducts of bisphenols is more preferably 25% by weight or less, further preferably 20% by weight or less.

The island component of the sea-island type composite fiber of the present invention is preferably a crystalline polymer. If the island component has crystallinity, a melting peak associated with melting of the crystal is observed in the measurement of the external melting start temperature by the method described in the examples. If the island component has crystallinity, the elution of the hygroscopic polymer of the island component into hot water is suppressed during hot water treatment such as dyeing, and thus the hygroscopicity can be maintained even after hot water treatment, which is preferable. ..

The sea component of the sea-island type composite fiber of the present invention preferably has crystallinity. If the sea component has crystallinity, a melting peak associated with melting of the crystal is observed in the measurement of the external melting start temperature by the method described in the examples. If the sea component has crystallinity, the fusion of fibers due to contact with the heating roller or heating heater in the stretching or false twisting process is suppressed, so that the deposits on the heating roller, heating heater, or guide are suppressed. It is preferable because it is less likely to cause thread breakage and fluffing, has good process passability, and has less dyeing spots and fluffing when made into a fiber structure such as a woven fabric or knitted fabric, and is excellent in quality. Further, it is preferable because the elution of sea components into hot water is suppressed during hot water treatment such as dyeing.

Specific examples of the sea component of the sea-island type composite fiber of the present invention include, but are not limited to, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, and polyolefins such as polyethylene and polypropylene. .. Among them, polyester is preferable because it has excellent mechanical properties and durability. In addition, when the sea component is a hydrophobic polymer such as polyester or polyolefin, the hygroscopic property of the island component's hygroscopic polymer and the dry feeling of the sea component's hydrophobic polymer can be achieved at the same time, and the fiber structure is excellent in wearing comfort. It is preferable because the body can be obtained.

Specific examples of the polyester relating to the sea component of the sea-island type composite fiber of the present invention include aromatic polyesters such as polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate, and aliphatic polyesters such as polylactic acid and polyglycolic acid. Not limited to these. Among them, polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate are preferable because they have excellent mechanical properties and durability, and are easy to handle during manufacturing and use. Further, polyethylene terephthalate is preferable because it gives a firmness and elasticity peculiar to polyester fibers, and polybutylene terephthalate is preferable because it has high crystallinity.

The sea component of the sea-island type composite fiber of the present invention is preferably a cationic dyeable polyester. If the polyester has an anionic moiety such as a sulfonic acid group, it has a cationic dyeability by interacting with a cationic dye having a cationic moiety. When the sea component is a cationic dyeable polyester, it is preferable because it exhibits vivid color development and can prevent dye contamination when mixed with polyurethane fibers. Specific examples of the copolymerization component of the cationic dyeable polyester include 5-sulfoisophthalic acid metal salts, and examples thereof include, but are not limited to, lithium salts, sodium salts, potassium salts, rubidium salts, and cesium salts. Of these, lithium salts and sodium salts are preferable, and sodium salts are particularly excellent in crystallinity and can be suitably adopted.

The sea-island type composite fiber of the present invention may be one that has undergone various modifications by adding a secondary additive to the sea component and / or the island component. Specific examples of secondary additives include compatibilizers, plasticizers, antioxidants, UV absorbers, infrared absorbers, optical brighteners, mold release agents, antibacterial agents, nucleating agents, heat stabilizers, and charging. Examples include, but are not limited to, inhibitors, colorants, modifiers, matting agents, defoaming agents, preservatives, gelling agents, latexes, fillers, inks, colorants, dyes, pigments, fragrances and the like. These secondary additives may be used alone or in combination of two or more.

The extrapolation melting start temperature of the sea-island type composite fiber of the present invention is preferably 150 to 300 ° C. The extrapolation melting start temperature of the sea-island type composite fiber in the present invention refers to a value calculated by the method described in Examples. When multiple melting peaks were observed, the extrapolation melting start temperature was calculated from the melting peak on the lowest temperature side. If the external melting start temperature of the Kaijima-type composite fiber is 150 ° C. or higher, the fusion of the fibers due to contact with the heating roller or heating heater in the stretching or false twisting process is suppressed, so that the heating roller or heating heater is suppressed. , There are few deposits, thread breaks, and fluff on the guide, and the process passage is good. When a fiber structure such as a woven fabric or knitted fabric is used, there is little dyeing spots or fluff, and the quality is excellent. preferable. The extrapolation melting start temperature of the sea-island type composite fiber is more preferably 170 ° C. or higher, further preferably 190 ° C. or higher, and particularly preferably 200 ° C. or higher. On the other hand, when the extrapolation melting start temperature of the sea-island type composite fiber is 300 ° C. or lower, yellowing due to thermal deterioration is suppressed in the melt spinning step, and the sea-island type composite fiber having a good color tone can be obtained, which is preferable.

The sea-island type composite fiber of the present invention has a ratio (T / R) of the outermost layer thickness T and the fiber diameter R of 0.05 to 0.25 in the fiber cross section. The outermost layer thickness in the present invention is the difference between the radius of the fiber and the radius of the circumscribed circle connecting the vertices of the island components arranged on the outermost circumference, and represents the thickness of the sea component existing in the outermost layer. The ratio (T / R) of the outermost layer thickness T and the fiber diameter R in the present invention refers to a value calculated by the method described in Examples. If the T / R of the sea-island type composite fiber is 0.05 or more, the thickness of the outermost layer with respect to the fiber diameter is sufficiently secured, so that the volume of the hygroscopic polymer placed on the island can be expanded by hot water treatment such as dyeing. It is possible to suppress the cracking of the sea component that accompanies it, the generation of dyeing spots and fluff caused by the cracking of the sea component is small, the quality is excellent, the elution of the hygroscopic polymer is suppressed, and high moisture absorption even after hot water treatment. Express sex. Further, by dyeing the sea component, sufficient color-developing property can be obtained, and in terms of color-developing property, high-quality fibers and fiber structures can be obtained. The T / R of the sea-island type composite fiber is more preferably 0.07 or more, further preferably 0.09 or more, and particularly preferably 0.10 or more. On the other hand, when the T / R of the sea-island type composite fiber is 0.25 or less, the volume swelling of the hygroscopic polymer arranged on the island is not impaired by the thickness of the outermost layer with respect to the fiber diameter, and the hygroscopicity of the hygroscopic polymer is exhibited. Therefore, fibers and fiber structures having high hygroscopicity can be obtained. The T / R of the sea-island type composite fiber is more preferably 0.22 or less, and further preferably 0.20 or less.

The outermost layer thickness T of the sea-island type composite fiber of the present invention is preferably 500 to 3000 nm. The outermost layer thickness T in the present invention refers to a value calculated by the method described in Examples. If the outermost layer thickness T of the sea-island type composite fiber is 500 nm or more, the thickness of the outermost layer is sufficiently secured. Cracking can be suppressed, dyeing spots and fluff caused by cracking of sea components are less likely to occur, excellent quality is achieved, elution of hygroscopic polymer is suppressed, and high hygroscopicity is exhibited even after hot water treatment. Therefore, it is preferable. In addition, dyeing of sea components is preferable because sufficient color development can be obtained and high-quality fibers and fiber structures can be obtained in terms of color development. The outermost layer thickness T of the sea-island type composite fiber is more preferably 700 nm or more, further preferably 800 nm or more, and particularly preferably 1000 nm or more. On the other hand, when the outermost layer thickness T of the sea-island type composite fiber is 3000 nm or less, the volume swelling of the hygroscopic polymer arranged on the island is not impaired by the thickness of the outermost layer with respect to the fiber diameter, and the hygroscopicity of the hygroscopic polymer is exhibited. , Highly hygroscopic fibers and fiber structures can be obtained, which is preferable. The outermost layer thickness T of the sea-island type composite fiber is more preferably 2500 nm or less, and further preferably 2000 nm or less.

The number of islands of the sea-island type composite fiber of the present invention is preferably 3 to 10,000. When the number of islands of the sea-island type composite fiber is 3 or more, the effect of dispersing the stress generated by the volume swelling of the hygroscopic polymer in hot water treatment such as dyeing is exhibited by the dispersion arrangement of the hygroscopic polymer which is an island component. Therefore, it is preferable because cracking of the sheath component due to stress concentration, which has been a problem of the conventional core-sheath type composite fiber, can be suppressed. The number of islands of the sea-island type composite fiber is more preferably 6 or more, further preferably 12 or more, and particularly preferably 20 or more. On the other hand, if the number of islands of the sea-island type composite fiber is 10,000 or less, the arrangement of the island components can be precisely controlled in the cross section of the fiber, and high-quality fibers and fiber structures can be obtained from the viewpoint of texture and color development. It is preferable because it can be obtained. The number of islands of the sea-island type composite fiber is more preferably 5000 or less, and further preferably 1000 or less.

In the sea-island type composite fiber of the present invention, the diameter r of the island component in the cross section of the fiber is preferably 10 to 5000 nm. The diameter r of the island component in the present invention refers to a value calculated by the method described in the examples. When the diameter r of the island component in the cross section of the fiber is 10 nm or more, the hygroscopic property of the hygroscopic polymer of the island component dispersed in the cross section of the fiber is exhibited, which is preferable. The diameter r of the island component in the fiber cross section of the sea-island type composite fiber is more preferably 100 nm or more, further preferably 500 nm or more. On the other hand, when the diameter r of the island component in the cross section of the fiber is 5000 nm or less, the stress generated by the volume swelling of the hygroscopic polymer arranged on the island can be reduced by hot water treatment such as dyeing, and the sea component can be treated. It is preferable because cracking can be suppressed. The diameter r of the island component in the fiber cross section of the sea-island type composite fiber is more preferably 3000 nm or less, further preferably 2000 nm or less.

In the sea-island type composite fiber of the present invention, it is preferable that the island components are arranged around 2 to 100 in the fiber cross section. In the present invention, the island components arranged concentrically in the cross section of the fiber are defined as one circumference, and the number of concentric circles having different diameters is the number of circumferences. When one island component is arranged at the center of the cross section of the fiber, one island component arranged at the center is defined as one circumference. 1 (a) to 1 (m) are examples of the cross-sectional shape of the sea-island type composite fiber of the present invention, and the island components are one round in FIGS. 1 (b) and 1 (c), respectively, and FIGS. 2 laps in d), (h), (i), (j), (k), (m), 3 laps in FIGS. 1 (e), (g), (l), 7 in FIG. 1 (f) It is placed around the circumference. We have conducted a detailed analysis of the stress distribution in the cross section of the fiber regarding the stress generated by the volume swelling of the hygroscopic polymer in hot water treatment such as dyeing. In the sea-island type composite fiber in which the island component is arranged in one circumference as shown in FIGS. 1 (b) and 1 (c), the stress becomes maximum at the interface between the fiber surface layer side of the island component and the sea component. I got the result. That is, in the core-sheath type composite fiber, a crack is generated at the interface between the core component and the sheath component where the stress is maximum due to the volume expansion of the hygroscopic polymer of the core component, and this crack propagates to the fiber surface layer to form the sheath. It was found that cracking of the components occurred. Similarly, in the sea-island type composite fiber in which the island component is arranged in one circumference, a crack occurs at the interface between the fiber surface layer side of the island component and the sea component where the stress is maximum due to the volume expansion of the hygroscopic polymer of the island component. This crack propagates to the surface layer of the fiber, causing cracking of the sea component. On the other hand, in the sea-island type composite fiber in which the island component is arranged in two or more laps in the fiber cross section, the fiber of the island component arranged on the outermost circumference on the inner layer side of the fiber and the fiber of the island component arranged on the inner side of one circumference from the outermost circumference. It is preferable because the stress is maximized between the surface layer side, the propagation of cracks to the fiber surface layer is blocked, and the cracking of the sea component is suppressed. In the fiber cross section of the sea-island type composite fiber, it is more preferable that the island components are arranged in three or more laps, and it is further preferable that the island components are arranged in four or more laps. On the other hand, if the island component is arranged on 100 laps or less, a space can be provided between the adjacent island component and the island component, so that the hygroscopic polymer of the island component can swell in volume with moisture absorption. It is preferable because a sea-island type composite fiber having excellent hygroscopicity can be obtained.

In the sea-island type composite fiber of the present invention, the ratio (r1 / r2) of the diameter r1 of the island component arranged so as to pass through the center of the fiber cross section and the diameter r2 of the other island components is 1.1 to 10.0. It is preferable to have. The ratio (r1 / r2) of the diameter r1 of the island component arranged so as to pass through the center of the cross section of the fiber in the present invention and the diameter r2 of the other island components refers to the value calculated by the method described in the examples. .. If the diameter r2 of the other island component is smaller than the diameter r1 of the island component arranged so as to pass through the center of the fiber cross section, r1 / r2 becomes larger than 1.0, and the sea-island type composite fiber in this case. 1 (k) to (m) can be mentioned as an example of the cross-sectional shape of. If r1 / r2 of the sea-island type composite fiber is 1.1 or more, the diameter r2 of the other island components is smaller than the diameter r1 of the island component arranged so as to pass through the center of the fiber cross section. It is preferable because the stress generated by the volume swelling of the hygroscopic polymer of the island component near the surface layer can be reduced and the cracking of the sea component can be suppressed. The r1 / r2 of the sea-island type composite fiber is more preferably 1.2 or more, and further preferably 1.5 or more. On the other hand, if r1 / r2 of the sea-island type composite fiber is 10.0 or less, the stress generated by the volume swelling of the hygroscopic polymer of the island component arranged so as to pass through the center of the cross section of the fiber is applied to the other island components. It is preferable because it can be absorbed, the propagation of cracks to the fiber surface layer is blocked, and the cracks of sea components can be suppressed. The r1 / r2 of the sea-island type composite fiber is more preferably 7.0 or less, and further preferably 5.0 or less.

The sea-island type composite fiber of the present invention is not particularly limited in terms of the shape of the island component in the fiber cross section, and may have a perfect circular cross section or a non-circular cross section. Specific examples of the non-circular cross section include, but are not limited to, a multi-leaf shape, a polygonal shape, a flat shape, and an elliptical shape. In particular, when the island component has a perfect circular cross section, when the hygroscopic polymer placed on the island expands in volume, stress is evenly generated on the circumference and stress is not concentrated, so cracks in the sea component occur. It is preferable because it can be suppressed. Further, it is preferable that the shape of the island component arranged on the outermost circumference on the center side of the fiber cross section is non-circular. In this case, in the island component arranged on the outermost circumference, stress is concentrated not on the surface layer side of the fiber but on the non-circular portion on the center side of the fiber, so that cracking of the sea component on the fiber surface layer can be suppressed, which is preferable.

The composite ratio (weight ratio) of the sea component / island component of the sea-island type composite fiber of the present invention is preferably 50/50 to 90/10. The composite ratio (weight ratio) of the sea component / island component of the sea-island type composite fiber in the present invention refers to a value calculated by the method described in the examples. When the composite ratio of the sea component of the sea-island type composite fiber is 50% by weight or more, it is preferable because the firmness, firmness and dry feel of the sea component can be obtained. In addition, cracking of the sea component due to external force during stretching and false twisting, and cracking of the sea component due to volume swelling of the hygroscopic polymer of the island component during moisture absorption and water absorption are suppressed, so that dyeing spots and fluff occur. This is preferable because the deterioration of the quality due to the above and the decrease in the hygroscopicity due to the elution of the polymer having the hygroscopicity of the island component into the hot water during the hot water treatment such as dyeing are suppressed. The composite ratio of the sea component of the sea-island type composite fiber is more preferably 55% by weight or more, further preferably 60% by weight or more. On the other hand, if the composite ratio of the sea component of the sea-island type composite fiber is 90% by weight or less, that is, the composite ratio of the island component is 10% by weight or more, the hygroscopic property of the island component hygroscopic polymer is exhibited and the hygroscopicity is excellent. It is preferable because a sea-island type composite fiber can be obtained. The composite ratio of the sea component of the sea-island type composite fiber is more preferably 85% by weight or less, and further preferably 80% by weight or less.

The fineness of the sea-island type composite fiber of the present invention as a multifilament is not particularly limited and may be appropriately selected depending on the application and required characteristics, but is preferably 10 to 500 dtex. The fineness in the present invention refers to a value measured by the method described in Examples. When the fineness of the Kaishima-type composite fiber is 10 dtex or more, it is preferable because there is little thread breakage, good process passability, less fluffing during use, and excellent durability. The fineness of the sea-island type composite fiber is more preferably 30 dtex or more, and further preferably 50 dtex or more. On the other hand, when the fineness of the sea-island type composite fiber is 500 dtex or less, it is preferable because the flexibility of the fiber and the fiber structure is not impaired. The fineness of the sea-island type composite fiber is more preferably 400 dtex or less, and further preferably 300 dtex or less.

The single yarn fineness of the sea-island type composite fiber of the present invention is not particularly limited and may be appropriately selected depending on the intended use and required characteristics, but is preferably 0.5 to 4.0 dtex. The single yarn fineness in the present invention refers to a value obtained by dividing the fineness measured by the method described in Examples by the number of single yarns. When the single yarn fineness of the Kaishima-type composite fiber is 0.5 dtex or more, it is preferable because there is little yarn breakage, good process passability, less fluffing during use, and excellent durability. The single yarn fineness of the sea-island type composite fiber is more preferably 0.6 dtex or more, and further preferably 0.8 dtex or more. On the other hand, when the single yarn fineness of the sea-island type composite fiber is 4.0 dtex or less, it is preferable because the flexibility of the fiber and the fiber structure is not impaired. The single yarn fineness of the sea-island type composite fiber is more preferably 2.0 dtex or less, and further preferably 1.5 dtex or less.

The strength of the sea-island type composite fiber of the present invention is not particularly limited and can be appropriately selected depending on the application and required characteristics, but it may be 2.0 to 5.0 cN / dtex from the viewpoint of mechanical characteristics. preferable. The strength in the present invention refers to a value measured by the method described in Examples. When the strength of the sea-island type composite fiber is 2.0 cN / dtex or more, fluffing is less likely to occur during use and the durability is excellent, which is preferable. The strength of the sea-island type composite fiber is more preferably 2.5 cN / dtex or more, and further preferably 3.0 cN / dtex or more. On the other hand, when the strength of the sea-island type composite fiber is 5.0 cN / dtex or less, it is preferable because the flexibility of the fiber and the fiber structure is not impaired.

The elongation of the sea-island type composite fiber of the present invention is not particularly limited and can be appropriately selected depending on the application and required characteristics, but is preferably 10 to 60% from the viewpoint of durability. The elongation in the present invention refers to a value measured by the method described in Examples. When the elongation of the sea-island type composite fiber is 10% or more, the abrasion resistance of the fiber and the fiber structure is good, fluffing is small during use, and the durability is good, which is preferable. The elongation of the sea-island type composite fiber is more preferably 15% or more, further preferably 20% or more. On the other hand, when the elongation of the sea-island type composite fiber is 60% or less, the dimensional stability of the fiber and the fiber structure is good, which is preferable. The elongation of the sea-island type composite fiber is more preferably 55% or less, further preferably 50% or less.

The difference in hygroscopicity (ΔMR) of the sea-island type composite fiber of the present invention after hot water treatment is 2.0 to 10.0%. The hygroscopicity difference (ΔMR) after hot water treatment in the present invention refers to a value measured by the method described in Examples. ΔMR is the difference between the hygroscopicity at a temperature of 30 ° C. and a humidity of 90% RH assuming the temperature and humidity inside the clothes after light exercise, and the hygroscopicity at an outside air temperature and humidity of 20 ° C. and a humidity of 65% RH. That is, ΔMR is an index of hygroscopicity, and the higher the value of ΔMR, the better the wearing comfort. The hygroscopicity difference (ΔMR) of the present invention is a value after hot water treatment, and is very important in that it shows that hygroscopicity is exhibited even after hot water treatment such as dyeing. When the ΔMR of the Kaishima-type composite fiber after hot water treatment is 2.0% or more, there is little stuffiness in the clothes and wearing comfort is exhibited. The ΔMR of the sea-island type composite fiber after hot water treatment is more preferably 2.5% or more, further preferably 3.0% or more, and particularly preferably 4.0% or more. On the other hand, if the ΔMR of the sea-island type composite fiber after hot water treatment is 10.0% or less, the process passability and handleability are good, and the durability during use is also excellent.

The sea-island type composite fiber of the present invention is not particularly limited in terms of the cross-sectional shape of the fiber, can be appropriately selected depending on the intended use and required characteristics, and may have a perfect circular cross section or a non-circular cross section. You may. Specific examples of the non-circular cross section include, but are not limited to, a multi-leaf shape, a polygonal shape, a flat shape, and an elliptical shape.

The sea-island type composite fiber of the present invention is not particularly limited in the form of the fiber, and may be in any form such as monofilament, multifilament, and staple.

The sea-island type composite fiber of the present invention can be processed into false twists and twisted yarns in the same manner as general fibers, and weaving and knitting can be handled in the same manner as general fibers.

The form of the fiber structure composed of the sea-island type composite fiber and / or falsely twisted yarn of the present invention is not particularly limited, and may be woven fabric, knitted fabric, pile fabric, non-woven fabric, spun yarn, stuffed cotton or the like according to a known method. can. Further, the fiber structure composed of the sea-island type composite fiber and / or false plying of the present invention may have any weave structure or knitted structure, and may be plain weave, twill weave, satin weave or a variable weave thereof, warp knitting, weft. A knitting, a circular knitting, a lace knitting, or a variation thereof can be preferably adopted.

The sea-island type composite fiber of the present invention may be combined with other fibers by cross-weaving or cross-knitting when forming a fiber structure, or may be used as a fiber structure after being made into a mixed fiber with other fibers.

Next, the method for producing the sea-island type composite fiber of the present invention is shown below.

As a method for producing a sea-island type composite fiber of the present invention, a known melt spinning method, drawing method, crimping method such as false twisting can be used.

In the present invention, it is preferable to dry the sea component and the island component to have a water content of 300 ppm or less before performing melt spinning. When the water content is 300 ppm or less, a decrease in molecular weight due to hydrolysis and foaming due to moisture are suppressed during melt spinning, and stable spinning can be performed, which is preferable. The water content is more preferably 100 ppm or less, and even more preferably 50 ppm or less.

In the present invention, the pre-dried chips are supplied to a melt spinning machine such as an extruder type or a pressure melter type to separately melt the sea component and the island component and weigh them with a measuring pump. After that, it is introduced into a heated spinning pack in a spinning block, the molten polymer is filtered in the spinning pack, and then the sea component and the island component are merged by the sea island composite mouthpiece described later to form a sea island structure and discharged from the spinning mouthpiece. It is made into a fiber thread.

In the present invention, as the sea-island composite base, for example, a conventionally known pipe-type sea-island composite base in which the pipe group disclosed in Japanese Patent Application Laid-Open No. 2007-100243 is arranged may be used. However, in the conventional pipe-type sea-island composite mouthpiece, the thickness of the sea component of the outermost layer is about 150 nm, which is the technical limit, and the ratio of the outermost layer thickness T to the fiber diameter R in the fiber cross section, which is an essential requirement of the present invention ( It is difficult to satisfy T / R). Therefore, in the present invention, the method using the Kaishima composite base described in Japanese Patent Application Laid-Open No. 2011-174215 is preferably used.

As an example of the Kaishima composite base used in the present invention, the Kaishima composite base composed of the members shown in FIGS. 2 to 4 will be described. 2 (a) to 2 (c) are explanatory views for schematically explaining an example of the sea-island composite base used in the present invention, and FIG. 2 (a) is a positive view of a main part constituting the sea-island composite base. A cross-sectional view, FIG. 2 (b) is a cross-sectional view of a part of the distribution plate, and FIG. 2 (c) is a cross-sectional view of a part of the discharge plate. 2 (b) and 2 (c) are distribution plates and discharge plates constituting FIG. 2 (a), FIG. 3 is a plan view of the distribution plate, and FIG. 4 is a part of the distribution plate in the present invention. It is an enlarged view, and each is described as a groove and a hole related to one discharge hole.

Hereinafter, the process from the formation of the composite polymer flow through the measuring plate and the distribution plate to the discharge from the discharge hole of the discharge plate will be described. From the upstream of the spinning pack, polymer A (island component) and polymer B (sea component) are the measuring holes for polymer A (10- (a)) and the measuring holes for polymer B (10- (b)) of the measuring plate of FIG. It flows into the distribution plate, is weighed by a hole throttle drilled at the lower end, and then flows into the distribution plate. In the distribution plate, the distribution groove 11 (FIGS. 3: 11- (a), 11- (b)) for merging the polymer flowing in from the measuring hole 10 and the lower surface of the distribution groove for flowing the polymer downstream. Distribution holes 12 (FIGS. 4: 12- (a), 12- (b)) are bored. Further, in order to form a layer composed of the polymer B which is a sea component in the outermost layer of the composite polymer flow, an annular groove 16 having a distribution hole as shown in FIG. 3 is provided on the bottom surface.

The composite polymer flow composed of the polymer A and the polymer B discharged from the distribution plate flows into the discharge plate 9 from the discharge introduction hole 13. The composite polymer stream is then reduced in cross-sectional direction along the polymer stream by the shrink holes 14 during introduction into the discharge holes having the desired diameter to maintain the cross-sectional morphology formed by the distribution plate. It is discharged from the discharge hole 15.

The fiber yarn discharged from the Kaijima composite mouthpiece is cooled and solidified by a cooling device, taken up by a first godet roller, and wound by a winder through a second godet roller to form a take-up yarn. In addition, in order to improve spinning operability, productivity, and mechanical properties of the fiber, a heating cylinder or a heat insulating cylinder having a length of 2 to 20 cm may be installed at the lower part of the spinneret, if necessary. Further, the fiber threads may be lubricated using a lubrication device, or the fiber threads may be entangled using an entanglement device.

The spinning temperature in melt spinning can be appropriately selected depending on the melting point and heat resistance of the sea component and the island component, but is preferably 240 to 320 ° C. When the spinning temperature is 240 ° C. or higher, the extensional viscosity of the fiber yarn discharged from the spinneret is sufficiently lowered to stabilize the discharge, and further, the spinning tension does not become excessively high and the yarn breakage is suppressed. It is preferable because it can be used. The spinning temperature is more preferably 250 ° C. or higher, further preferably 260 ° C. or higher. On the other hand, when the spinning temperature is 320 ° C. or lower, thermal decomposition during spinning can be suppressed, and deterioration of mechanical properties and coloring of the fiber can be suppressed, which is preferable. The spinning temperature is more preferably 310 ° C. or lower, and even more preferably 300 ° C. or lower.

The spinning speed in melt spinning can be appropriately selected according to the composition of the sea component, the island component, the spinning temperature, and the like. In the case of the two-step method in which melt spinning is performed once, winding is performed, and then stretching or false twisting is performed separately, the spinning speed is preferably 500 to 6000 m / min. When the spinning speed is 500 m / min or more, the running yarn is stable and yarn breakage can be suppressed, which is preferable. In the case of the two-step method, the spinning speed is more preferably 1000 m / min or more, and further preferably 1500 m / min or more. On the other hand, when the spinning speed is 6000 m / min or less, stable spinning can be performed without yarn breakage by suppressing the spinning tension, which is preferable. In the case of the two-step method, the spinning speed is more preferably 4500 m / min or less, and further preferably 4000 m / min or less. Further, in the case of the one-step method in which spinning and drawing are performed at the same time without winding once, the spinning speed is preferably 500 to 5000 m / min for the low-speed roller and 2500 to 6000 m / min for the high-speed roller. When the low-speed roller and the high-speed roller are within the above range, the running yarn is stable, yarn breakage can be suppressed, and stable spinning can be performed, which is preferable. In the case of the one-step method, the spinning speed is more preferably 1000 to 4500 m / min for the low-speed roller and 3500 to 5500 m / min for the high-speed roller, 1500-4000 m / min for the low-speed roller and 4000-5000 m / min for the high-speed roller. Is more preferable.

When stretching is performed by a one-step method or a two-step method, either a one-step stretching method or a two-step or more multi-step stretching method may be used. The heating method in drawing is not particularly limited as long as it is a device capable of directly or indirectly heating the running yarn. Specific examples of the heating method include, but are not limited to, heating rollers, hot pins, hot plates, hot water, liquid baths such as hot water, hot air, gas baths such as steam, and lasers. These heating methods may be used alone or in combination of two or more. As the heating method, control of the heating temperature, uniform heating of the running thread, contact with the heating roller, contact with the heat pin, contact with the hot plate, and immersion in the liquid bath are performed from the viewpoint of not complicating the device. It can be suitably adopted.

The stretching temperature at the time of stretching can be appropriately selected depending on the extrapolation melting start temperature of the polymer of the sea component and the island component, the strength of the fiber after stretching, the elongation, etc., but is at 50 to 150 ° C. It is preferable to have. When the stretching temperature is 50 ° C. or higher, the yarn supplied for stretching is sufficiently preheated, the thermal deformation during stretching becomes uniform, the occurrence of fineness spots can be suppressed, the dyeing spots and fluff are few, and the quality is high. Is preferable because it becomes good. The stretching temperature is more preferably 60 ° C. or higher, and even more preferably 70 ° C. or higher. On the other hand, when the stretching temperature is 150 ° C. or lower, fusion and thermal decomposition of the fibers due to contact with the heating roller can be suppressed, and process passability and quality are good, which is preferable. Further, since the slipperiness of the fiber with respect to the drawing roller is improved, yarn breakage is suppressed and stable drawing can be performed, which is preferable. The stretching temperature is more preferably 145 ° C. or lower, and even more preferably 140 ° C. or lower. Further, heat setting at 60 to 150 ° C. may be performed if necessary.

The draw ratio in the case of stretching can be appropriately selected depending on the elongation of the fiber before stretching, the strength and elongation of the fiber after stretching, and the like, but it should be 1.02 to 7.0 times. Is preferable. When the draw ratio is 1.02 times or more, it is preferable because the mechanical properties such as the strength and elongation of the fiber can be improved by stretching. The draw ratio is more preferably 1.2 times or more, and further preferably 1.5 times or more. On the other hand, when the draw ratio is 7.0 times or less, yarn breakage at the time of drawing is suppressed and stable drawing can be performed, which is preferable. The draw ratio is more preferably 6.0 times or less, and further preferably 5.0 times or less.

The stretching speed at the time of stretching can be appropriately selected depending on whether the stretching method is a one-step method or a two-step method. In the case of the one-step method, the speed of the high-speed roller at the spinning speed corresponds to the drawing speed. When stretching by the two-step method, the stretching speed is preferably 30 to 1000 m / min. When the drawing speed is 30 m / min or more, the running yarn is stable and the yarn breakage can be suppressed, which is preferable. When stretching by the two-step method, the stretching speed is more preferably 50 m / min or more, and further preferably 100 m / min or more. On the other hand, when the stretching speed is 1000 m / min or less, yarn breakage during stretching is suppressed and stable stretching can be performed, which is preferable. When stretching by the two-step method, the stretching speed is more preferably 900 m / min or less, and further preferably 800 m / min or less.

In the case of false twisting, so-called bulería processing, in which both a one-stage heater and a two-stage heater are used, can be appropriately selected in addition to the so-called woolly processing in which only the one-stage heater is used. The heating method of the heater may be either a contact type or a non-contact type. Specific examples of the false twisting machine include, but are not limited to, a friction disc type, a belt nip type, and a pin type.

The heater temperature at the time of false twisting can be appropriately selected depending on the extrapolation melting start temperature of the polymer of the sea component and the island component, but is preferably 120 to 210 ° C. When the heater temperature is 120 ° C. or higher, the yarn supplied for false twisting is sufficiently preheated, the thermal deformation due to stretching becomes uniform, the occurrence of fineness spots can be suppressed, and there are few dyeing spots and fluff. , It is preferable because the quality is good. The heater temperature is more preferably 140 ° C. or higher, and even more preferably 160 ° C. or higher. On the other hand, when the heater temperature is 210 ° C. or lower, fusion and thermal decomposition of fibers due to contact with the heater are suppressed, so that there is little thread breakage and stains on the heater, and process passability and quality are improved. It is preferable because it is good. The heater temperature is more preferably 200 ° C. or lower, and even more preferably 190 ° C. or lower.

The draw ratio in the case of false twisting can be appropriately selected depending on the elongation of the fiber before false twisting and the strength and elongation of the fiber after false twisting, but 1.01 to 2 It is preferably 5.5 times. When the draw ratio is 1.01 times or more, it is preferable because the mechanical properties such as the strength and elongation of the fiber can be improved by stretching. The draw ratio is more preferably 1.2 times or more, and further preferably 1.5 times or more. On the other hand, when the draw ratio is 2.5 times or less, yarn breakage during false twisting is suppressed and stable false twisting can be performed, which is preferable. The draw ratio is more preferably 2.2 times or less, and further preferably 2.0 times or less.

The processing speed in the case of false twisting can be appropriately selected, but is preferably 200 to 1000 m / min. When the processing speed is 200 m / min or more, the running yarn is stable and the yarn breakage can be suppressed, which is preferable. The processing speed is more preferably 300 m / min or more, and further preferably 400 m / min or more. On the other hand, when the processing speed is 1000 m / min or less, yarn breakage during false twisting is suppressed and stable false twisting can be performed, which is preferable. The processing speed is more preferably 900 m / min or less, and further preferably 800 m / min or less.

In the present invention, if necessary, dyeing may be performed in either the state of the fiber or the fiber structure. In the present invention, a disperse dye can be suitably adopted as the dye.

The dyeing method in the present invention is not particularly limited, and a cheese dyeing machine, a liquid flow dyeing machine, a drum dyeing machine, a beam dyeing machine, a jigger, a high pressure jigger and the like can be preferably adopted according to a known method.

In the present invention, there is no particular limitation on the dye concentration and the dyeing temperature, and a known method can be preferably adopted. Further, if necessary, refining may be performed before the dyeing process, or reduction cleaning may be performed after the dyeing process.

The sea-island type composite fiber of the present invention and the false twisted yarn and the fiber structure made thereof have excellent hygroscopicity. Therefore, it can be suitably used in applications where comfort and dignity are required. For example, general clothing use, sports clothing use, bedding use, interior use, material use and the like can be mentioned, but the present invention is not limited thereto.

Hereinafter, the present invention will be described in more detail by way of examples. In addition, each characteristic value in an Example was obtained by the following method.

A. Difference in hygroscopicity between sea and island components (△ MR)
Using a polymer of sea component or island component as a sample, it is first dried with hot air at 60 ° C for 30 minutes, and then statically charged for 24 hours in an Espec constant temperature and humidity controller LHU-123 whose temperature is 20 ° C and humidity is 65% RH. After the sample was placed and the weight of the polymer (W1) was measured, the sample was allowed to stand in a constant temperature and humidity chamber adjusted to a temperature of 30 ° C. and a humidity of 90% RH for 24 hours, and the weight of the polymer (W2) was measured. Then, it was dried with hot air at 105 ° C. for 2 hours, and the weight (W3) of the polymer after absolute drying was measured. Using the polymer weights W1 and W3, the hygroscopicity MR1 (%) was calculated from an absolutely dry state at a temperature of 20 ° C. and a humidity of 65% in an RH atmosphere for 24 hours, and the polymer weights W2 and W3 were calculated. After calculating the hygroscopicity rate MR2 (%) when the product is allowed to stand in a dry state at a temperature of 30 ° C. and a humidity of 90% RH for 24 hours using the following formula, the hygroscopicity difference (ΔMR) is calculated by the following formula. Calculated. The measurement was performed 5 times per sample, and the average value was taken as the hygroscopicity difference (ΔMR).

MR1 (%) = {(W1-W3) / W3} x 100
MR2 (%) = {(W2-W3) / W3} x 100
Hygroscopicity difference (ΔMR) (%) = MR2-MR1.

B. External melting start temperature The external melting start temperature was measured using a differential scanning calorimeter (DSC) Q2000 manufactured by TA Instruments, using the polymers of the sea component and island component and the fibers obtained by the examples as samples. .. First, about 5 mg of the sample was heated from 0 ° C. to 280 ° C. at a heating rate of 50 ° C./min under a nitrogen atmosphere, and then held at 280 ° C. for 5 minutes to remove the thermal history of the sample. Then, after quenching from 280 ° C. to 0 ° C., the temperature was raised again from 0 ° C. to 280 ° C. at a temperature rise rate of 3 ° C./min, a temperature modulation amplitude of ± 1 ° C., and a temperature modulation cycle of 60 seconds, and TMDSC measurement was performed. The supplementary melting start temperature was calculated from the melting peak observed during the second temperature rise process according to JIS K7121: 1987 (method for measuring the transition temperature of plastic) 9.1. The measurement was performed 3 times per sample, and the average value was taken as the extrapolation melting start temperature. When multiple melting peaks were observed, the extrapolation melting start temperature was calculated from the melting peak on the lowest temperature side.

C. Sea / Island Composite Ratio The sea / island composite ratio (weight ratio) was calculated from the weight of the sea component and the weight of the island component used as the raw material of the sea-island type composite fiber.

D. In an environment of a fineness temperature of 20 ° C. and a humidity of 65% RH, 100 m of the fiber obtained in the examples was squeezed using an electric measuring machine manufactured by INTEC. The weight of the obtained skein was measured, and the fineness (dtex) was calculated using the following formula. The measurement was performed 5 times per sample, and the average value was taken as the fineness.

Fineness (dtex) = weight (g) of 100 m of fiber x 100.

E. Strength, Elongation The strength and elongation were calculated according to JIS L1013: 2010 (chemical fiber filament yarn test method) 8.5.1 using the fibers obtained in the examples as samples. A tensile test was carried out under the conditions of an initial sample length of 20 cm and a tensile speed of 20 cm / min using Tensilon UTM-III-100 manufactured by Orientec Co., Ltd. in an environment of a temperature of 20 ° C. and a humidity of 65% RH. The strength (cN / dtex) is calculated by dividing the stress (cN) at the point indicating the maximum load by the fineness (dtex), and the following is used using the elongation (L1) and the initial sample length (L0) at the point indicating the maximum load. The elongation (%) was calculated by the formula. The measurement was performed 10 times per sample, and the average value was taken as the intensity and elongation.

Elongation (%) = {(L1-L0) / L0} × 100.

F. Fiber diameter R
The fibers obtained in the examples were embedded in epoxy resin, frozen in a Reichert FC / 4E cryosectioning system, and cut with a Reichert-Nissei ultracut N (ultramicrotome) equipped with a diamond knife. Then, the cut surface, that is, the cross section of the fiber was observed at 1000 times using a transmission electron microscope (TEM) H-7100FA type manufactured by Hitachi, Ltd., and a micrograph of the cross section of the fiber was taken. Ten single yarns were randomly extracted from the obtained photographs, the fiber diameters of all the extracted single yarns were measured using image processing software (WINROOF manufactured by Mitani Shoji), and the average value was calculated as the fiber diameter R (fiber diameter R). nm). Since the fiber cross section is not always a perfect circle, the diameter of the circumscribed circle of the fiber cross section is used as the fiber diameter when the fiber cross section is not a perfect circle.

G. Outermost layer thickness T
The cross section of the fiber was observed by the same method as the fiber diameter described in F above, and a micrograph was taken at the highest magnification at which the entire image of the single yarn could be observed. In the obtained photograph, using image processing software (WINROOF manufactured by Mitani Shoji), the radius of a perfect circle that touches the contour of the cross section of the fiber at two or more points is obtained as the radius of the fiber, and further, as shown in 4 in FIG. The radius of a perfect circle (circumscribed circle) that circumscribes two or more island components arranged on the outer circumference of the sea island structure was calculated. Ten single yarns were randomly extracted from the obtained photographs, and the radius of the fiber and the radius of the circumscribed circle of the sea island structure part were obtained in the same manner. The difference was calculated, and the average value was taken as the outermost layer thickness T (nm).

H. T / R
The T / R was calculated by dividing the outermost layer thickness T (nm) calculated by G above by the fiber diameter R (nm) calculated by F.

I. Diameters of island components r, r1, r2
The cross section of the fiber was observed by the same method as the fiber diameter described in F above, and a micrograph was taken at the highest magnification at which the entire image of the single yarn could be observed. In the obtained photographs, the diameters of all the island components in the cross section of the fiber were measured using image processing software (WINROOF manufactured by Mitani Corporation). Since the island component is not always a perfect circle, the diameter of the circumscribed circle of the island component is adopted as the diameter of the island component when it is not a perfect circle. In the fiber cross section
The average value of the diameters of all the island components was calculated as r, the diameter of the island components passing through the center was r1, and the average value of the diameters of all the island components excluding the island components passing through the center was r2. Ten single yarns were randomly extracted from the obtained photographs, r, r1 and r2 were obtained in the same manner for each single yarn, and the average values were r (nm), r1 (nm) and r2 (nm). bottom.

J. r1 / r2
r1 / r2 was calculated by dividing r1 (nm) calculated in I above by r2 (nm) calculated in I above.

K. Difference in moisture absorption rate after refining and hot water treatment (△ MR)
Using the fibers obtained in the examples as a sample, about 2 g of tubular knitting was prepared using a circular knitting machine NCR-BL (pot diameter 3.5 inches (8.9 cm), 27 gauge) manufactured by Eiko Sangyo, and then 1 g of sodium carbonate. After scouring at 80 ° C. for 20 minutes in an aqueous solution containing / L, the surfactant Sunmol BK-80 manufactured by NICCA CHEMICAL CO., LTD. Further, the cylinder knitting after scouring is treated with hot water under the conditions of a bath ratio of 1: 100, a treatment temperature of 130 ° C., and a treatment time of 60 minutes, and then dried in a hot air dryer at 60 ° C. for 60 minutes. I knit it.

The moisture absorption rate (%) was calculated according to the moisture content of JIS L1096: 2010 (woven fabric and knitted fabric test method) 8.10 using the tube knitting after scouring and hot water treatment as a sample. First, the tube knitting was dried with hot air at 60 ° C. for 30 minutes, and then the tube knitting was allowed to stand in the ESPEC constant temperature and humidity chamber LHU-123 whose temperature was 20 ° C. and the humidity was 65% RH for 24 hours. After measuring the weight of the knitting (W1), the tube knitting was allowed to stand for 24 hours in a constant temperature and humidity constant machine adjusted to a temperature of 30 ° C. and a humidity of 90% RH, and the weight of the tube knitting (W2) was measured. Then, the tube knitting was dried with hot air at 105 ° C. for 2 hours, and the weight (W3) of the tube knitting after absolute drying was measured. Using the weights W1 and W3 of the tube knitting, the hygroscopicity MR1 (%) when the product was allowed to stand in an RH atmosphere with a temperature of 20 ° C. and a humidity of 65% for 24 hours was calculated by the following formula, and the weight of the tube knitting was W2. After calculating the hygroscopicity MR2 (%) when the product is allowed to stand in a dry state at a temperature of 30 ° C. and a humidity of 90% RH for 24 hours using W3, the hygroscopicity difference (ΔMR) is calculated by the following formula. ) Was calculated. The measurement was performed 5 times per sample, and the average value was taken as the hygroscopicity difference (ΔMR).

MR1 (%) = {(W1-W3) / W3} x 100
MR2 (%) = {(W2-W3) / W3} x 100
Hygroscopicity difference (ΔMR) (%) = MR2-MR1.

L. Cracking of sea components The tubular knitting after hot water treatment prepared in K above was vapor-deposited with a platinum-palladium alloy, observed at 1000 times using a Hitachi scanning electron microscope (SEM) S-4000, and randomly observed. A 10-field micrograph was taken. In the obtained 10 photographs, the total number of places where the sea component was cracked was defined as the cracks (points) of the sea component.

M. L ^* value The tube knitting after scouring prepared in the same manner as the above K is dry-heat set at 160 ° C. for 2 minutes, and for the tube knitting after the dry-heat setting, as a disperse dye, Kayalon Polyester Blue UT-YA manufactured by Nippon Kayaku Co., Ltd. Was dyed in a dyeing solution having a pH adjusted to 5.0 by adding 1.3% by weight under the conditions of a bath ratio of 1: 100, a dyeing temperature of 130 ° C., and a dyeing time of 60 minutes. When cationic dyeable polyester was used as a sea component, 1.0% by weight of Kayacryl Blue 2RL-ED manufactured by Nippon Kayaku Co., Ltd. was added as a cationic dye, and the pH was adjusted to 4.0 in a bath in a dyeing solution. Staining was performed under the conditions of a ratio of 1: 100, a staining temperature of 130 ° C., and a staining time of 60 minutes.

^{Using the dyed tube knitting as a sample, the L *} value was measured using a Minolta spectrophotometer CM-3700d with a D65 light source, a viewing angle of 10 °, and optical conditions of SCE (specular reflected light removal method). The measurement was performed three times per sample, and the average value was taken as the L ^* value.

N. Uniform dyeing property Regarding the tube knitting after dyeing made with M above, by the consensus of five inspectors who have more than 5 years of experience in quality judgment, "It is dyed very uniformly and no dyeing spots are observed. "S," almost uniformly dyed, almost no dyed spots "is A," almost uniformly dyed, slightly dyed spots are observed "B," uniformly dyed "No, there is a clear dyeing spot" was given as C, and A and S were given as passed.

O. Quality With regard to the tube knitting after dyeing made with M above, "no fluff, extremely excellent quality" was given by S and "almost no fluff" by the consensus of five inspectors who have more than 5 years of experience in quality judgment. "Excellent in dignity" was A, "has fluff and is inferior in dignity" was B, and "many fluff and extremely inferior in dignity" was C, and A and S were accepted.

P. Dry feeling Regarding the tube knitting after dyeing made with M above, "there is no sliminess or stickiness, and the dry feeling is extremely excellent" by the discussion of five inspectors who have more than 5 years of experience in quality judgment. "There is almost no slimy or sticky feeling, and the dry feeling is excellent" is A, "There is slimy or sticky, and the dry feeling is inferior" is B, "The slimy or sticky feeling is extremely strong and the dry feeling is extremely inferior" is C, A, S was accepted.

(Example 1)
Polyethylene terephthalate obtained by copolymerizing 30% by weight of polyethylene glycol (PEG6000S manufactured by Sanyo Kasei Kogyo Co., Ltd.) having a number average molecular weight of 8300 g / mol was used as an island component, and polyethylene terephthalate (IV = 0.66) was used as a sea component. After time vacuum drying, the island component was supplied to the extruder type composite spinning machine at a blending ratio of 30% by weight and the sea component was 70% by weight, and melted separately. At a spinning temperature of 285 ° C., FIG. 2A shows. It was flowed into a spinning pack incorporating the Kaijima composite mouthpiece shown, and a composite polymer stream was discharged from a discharge hole at a discharge rate of 25 g / min to obtain a spun yarn. The distribution plate directly above the discharge plate is provided with 18 distribution holes per discharge hole for the island component, and the annular groove for the sea component shown in FIG. 16 16 has a circumferential direction of 1. A distribution hole was used for each °. The discharge introduction hole length is 5 mm, the reduction hole angle is 60 °, the discharge hole diameter is 0.18 mm, the discharge hole length / discharge hole diameter is 2.2, and the number of discharge holes is 72. The spun yarn is cooled with a cooling air having a wind temperature of 20 ° C. and a wind speed of 20 m / min, and an oil agent is applied by a refueling device to converge the spun yarn. An undrawn yarn of 92dtex-72f was obtained by winding with a winder via a second Goddet roller rotating at the same speed as the dead roller. Then, using a draw false twisting machine (twisting part: friction disc type, heater part: contact type), the obtained undrawn yarn was drawn and false twisted under the conditions of a heater temperature of 140 ° C. and a magnification of 1.4 times. A false twisted yarn of 66dtex-72f was obtained.

Table 1 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Although there were slight cracks in the sea components, there was almost no decrease in hygroscopicity due to hot water treatment, and the hygroscopicity was good even after hot water treatment. In addition, the color development was good, and the level of dyeability, quality, and dryness were all acceptable.

(Examples 2 to 5), (Comparative Example 1)
False plying was produced in the same manner as in Example 1 except that the ratio (T / R) of the outermost layer thickness T to the fiber diameter R was changed as shown in Table 1.

Table 1 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. In Examples 2 to 5, as the T / R increases, the cracking of the sea component decreases and the color development property improves. On the other hand, although the hygroscopicity after the hot water treatment was low, the hygroscopicity was good. In all cases, the level of dyeability, quality, and dryness were all acceptable. On the other hand, in Comparative Example 1, although the color development property, the leveling property, the quality, and the dry feeling were good, the T / R was large, and as a result, the volume swelling of the hygroscopic polymer of the island component was suppressed. Both after the treatment, the hygroscopicity was low.

(Comparative Example 2)
False plying was produced in the same manner as in Example 1 except that the conventionally known pipe-type sea-island composite base (18 islands per discharge hole) described in JP-A-2007-100243 was used.

Table 1 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. When a conventionally known pipe-type sea-island composite base is used, the thickness of the outermost layer of the obtained fiber is thin, so that the sea component is extremely cracked due to the volume expansion of the hygroscopic polymer of the island component in hot water treatment. It was a thing. Due to the cracking of the sea component, the hygroscopic polymer of the island component was eluted during the hot water treatment, and the hygroscopicity was greatly reduced after the hot water treatment, and the hygroscopicity was inferior. In addition, many dyeing spots and fluffs due to cracking of sea components were observed, and the dyeability and dignity were extremely inferior. Furthermore, due to the cracking of the sea component, a part of the hygroscopic polymer of the island component was exposed on the surface, and it was slimy and sticky, and the dry feeling was also inferior.

(Comparative Example 3)
False plying was produced in the same manner as in Example 1 except that the core-sheath composite base was used. In Comparative Example 3, the sea component and the island component shown in Table 1 correspond to the sheath component and the core component, respectively.

Table 1 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. In the hot water treatment, the sheath component cracked due to the volume swelling of the hygroscopic polymer of the core component. Due to the cracking of the sheath component, the hygroscopic polymer of the core component was eluted during the hot water treatment, and the hygroscopicity was greatly reduced after the hot water treatment, and the hygroscopicity was inferior. In addition, many dyeing spots and fluffs due to cracking of the sheath component were observed, and the dyeability and quality were extremely inferior. Furthermore, due to the cracking of the sheath component, a part of the hygroscopic polymer of the core component was exposed on the surface, and the surface was slimy and sticky, and the dry feeling was also inferior.

(Examples 6 to 11)
In the distribution plate of the sea-island composite base described in Example 1, false plying was produced in the same manner as in Example 1 except that the number and arrangement of island components were changed as shown in Table 2.

Table 2 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Even when the number and arrangement of island components were changed, there were few cracks in the sea components, and the hygroscopicity after hot water treatment was good. In addition, the color development was good, and the level of dyeability, quality, and dryness were all acceptable.

(Examples 12 to 15)
False plying was produced in the same manner as in Example 9 except that the sea / island composite ratio was changed as shown in Table 3.

Table 3 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. In all the sea / island composite ratios, the cracking of the sea component was small, and the hygroscopicity, color development, leveling property, dignity, and dry feeling after the hot water treatment were all good.

(Examples 16 to 18)
In the distribution plate of the sea-island composite base according to Example 1, the shape of the island component is hexagonal as shown in FIG. 1 (h) in Example 16 and trilobal as shown in FIG. 1 (i) in Example 17. In Example 18, a false twisted yarn was produced in the same manner as in Example 1 except that the shape of the center side of the fiber cross section was changed to a non-circular shape in the island component arranged on the outermost circumference as shown in FIG. 1 (j). ..

Table 3 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Even if the shape of the island component is changed
There were few cracks in the sea components, and the hygroscopicity, color development, leveling property, quality, and dry feeling after hot water treatment were all good. In particular, in Example 18, in the island component arranged on the outermost circumference, not the fiber surface layer side but the fiber inner layer side is non-circular, so that stress is concentrated on this non-circular portion and the cracks propagate to the fiber surface layer. Was blocked, and the effect of suppressing cracking of sea components was excellent.

(Examples 19 to 23)
In the distribution plate of the sea-island composite base according to Example 1, the diameter r1 of the island component and the diameter r2 of the other island components arranged so as to pass through the center of the fiber cross section by changing the number and arrangement of the island components. False plying was produced in the same manner as in Example 1 except that the ratio (r1 / r2) was changed as shown in Table 4.

Table 4 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. As r1 / r2 increased, the cracking of the sea component decreased and the color developing property improved, while the hygroscopicity after the hot water treatment decreased, but the hygroscopicity was good. In all cases, the level of dyeability, quality, and dryness were all acceptable.

(Examples 24 to 26), (Comparative Examples 4 and 5)
False plying was produced in the same manner as in Example 9 except that the number average molecular weight and the copolymerization rate of polyethylene glycol, which is a copolymerization component of the island component, were changed as shown in Table 5.

Table 5 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. In Examples 24 to 26, even when the number average molecular weight and the copolymerization rate of polyethylene glycol were changed, there was little cracking of the sea component, and hygroscopicity, color development, leveling property, quality, and dry feeling after hot water treatment were observed. It was good for all of. On the other hand, in Comparative Examples 4 and 5, there was no cracking of the sea component, and although the color development property, the leveling property, and the dry feeling were good, the hygroscopic property of the hygroscopic polymer of the island component was low, so that after scouring, hot water treatment was performed. Both later, the hygroscopicity was low, and the hygroscopicity was extremely inferior.

(Examples 27 and 28)
False plying was produced in the same manner as in Example 9 except that the island component was changed to polybutylene terephthalate copolymerized as shown in Table 6 in terms of the number average molecular weight and copolymerization rate of polyethylene glycol.

Table 6 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Even when polybutylene terephthalate copolymerized with polyethylene glycol is used as the island component, the sea component is less cracked, and the hygroscopicity, color development, leveling property, dignity, and dry feeling after hot water treatment are all good. rice field.

(Example 29 (reference example) , 30 (reference example) )
The island component, Example 29 (Reference Example) In a number average molecular weight 3400 g / mol polyethylene glycol (manufactured by Sanyo Chemical Industries, Ltd. PEG4000S) Nylon 6 obtained by polymerizing 30% by weight both of Example 30 (Reference Example) In Arkema made "PEBAX False twisted yarn was produced in the same manner as in Example 9 except that it was changed to MH1657 ”.

Table 6 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Even when the polyether amide was used as the island component, the sea component was less cracked, and the hygroscopicity, color development, leveling property, dignity, and dry feeling after the hot water treatment were all good.

(Example 31 (reference example) )
False plying was produced in the same manner as in Example 9 except that the island component was changed to "PAS-40N" manufactured by Toray Industries.

Table 6 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Even when the polyether ester amide was used as the island component, the sea component was less cracked, and the hygroscopicity, color development, leveling property, dignity, and dry feeling after the hot water treatment were all good.

(Examples 32 and 33)
Polyethylene terephthalate (IV) obtained by copolymerizing the sea component with 1.5 mol% of 5-sulfoisophthalic acid sodium salt and 1.0% by weight of polyethylene glycol (PEG1000 manufactured by Sanyo Chemical Industries, Ltd.) having a number average molecular weight of 1000 g / mol in Example 32. = 0.66), and false twisted yarn was produced in the same manner as in Example 19 except that it was changed to polybutylene terephthalate (IV = 0.66) in Example 33.

Table 7 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Even when a cationic dyeable polyester as in Example 32 or polybutylene terephthalate as in Example 33 is used as the sea component, the sea component is less cracked and has hygroscopicity after hot water treatment. , Color development, leveling property, dignity, and dry feeling were all good.

(Examples 34 to 37)
In Example 34, the discharge amount is 32 g / min, the number of discharge holes of the Kaijima composite mouthpiece is 24, in Example 35, the discharge amount is 32 g / min, the number of discharge holes of the Kaijima composite mouthpiece is 48, and in Example 36, the discharge amount is 32 g. A false plying yarn was produced in the same manner as in Example 19 except that the discharge rate was changed to 38 g / min in Example 37. False plying of 84 dtex-24f in Example 34, 84 dtex-48f in Example 35, 84 dtex-72f in Example 36, and 100 dtex-72f in Example 37 was obtained.

Table 7 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Even when the fineness and single yarn fineness were changed, there was little cracking of the sea component, and the hygroscopicity, color development, leveling property, dignity, and dry feeling after hot water treatment were all good.

(Comparative Example 6)
False-twisted yarns were produced in the same manner as in Example 1 except that the spinning caps for single components (number of holes: 72, round holes) were changed and spinning and drawn false twisting were performed using only a hygroscopic polymer.

Table 8 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Since the fiber is composed only of a hygroscopic polymer, it has high hygroscopicity after hot water treatment. However, the discharge from the spinneret was unstable, the obtained fibers were often thick and thin, the strength was low, and many dyeing spots and fluffs were observed, and the dyeability and quality were extremely inferior. Furthermore, since the hygroscopic polymer is exposed on the fiber surface, it is slimy and sticky, and the dry feeling is extremely inferior.

(Comparative Example 7)
In Example 19, false plying was produced in the same manner as in Example 19 except that the sea component and the island component were replaced and the sea / island composite ratio was changed to 30/70.

Table 8 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. There is no cracking of the sea component, and the hygroscopicity and color development after hot water treatment are good, but the hygroscopic polymer of the sea component is exposed on the fiber surface, so it is slimy and sticky, and the dry feeling is extremely inferior. It was a thing. In addition, the level of dyeability and quality did not reach the passing level.

(Comparative Example 8)
False plying was produced in the same manner as in Example 32, except that the island component was changed to polyethylene terephthalate (IV = 0.66).

Table 8 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. There was no cracking of the sea component, and the color development, leveling property, dignity, and dry feeling were good, but since neither the sea component nor the island component was a hygroscopic polymer, the hygroscopic property was extremely inferior.

(Example 38)
35% by weight of polyethylene glycol (PEG6000S manufactured by Sanyo Chemical Industries) with a number average molecular weight of 8300 g / mol and 19 weights of ethylene oxide adduct [m + n = 4] (New Pole BPE-40 manufactured by Sanyo Chemical Industries) of bisphenol A. False twisted yarns were produced in the same manner as in Example 9 except that the polyethylene terephthalate was changed to% copolymerized polyethylene terephthalate.

Table 9 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Even when polyethylene terephthalate, which is a copolymer of polyethylene glycol and ethylene oxide adduct of bisphenol A, is used as the island component, the sea component is less cracked, and the moisture absorption, color development, leveling property, grade, and dryness after hot water treatment are small. All of the feelings were good.

(Examples 39 to 41)
In Example 38, false plying was produced in the same manner as in Example 38, except that the ethylene oxide adduct “m + n” of bisphenol A, which is a copolymerization component of the island component, and the copolymerization rate were changed as shown in Table 9. ..

Table 9 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Even when the ethylene oxide adduct "m + n" of bisphenol A and the copolymerization rate were changed, there was little cracking of the sea component, and hygroscopicity, color development, leveling, grade, and dryness after hot water treatment were all observed. It was good.

(Examples 42 and 43)
In Example 40, false plying was produced in the same manner as in Example 40, except that the copolymerization rate of polyethylene glycol, which is a copolymerization component of the island component, was changed as shown in Table 10.

Table 10 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Even when the copolymerization rate of polyethylene glycol was changed, cracking of the sea component was small, and hygroscopicity, color development, leveling property, quality, and dry feeling after hot water treatment were all good.

(Examples 44 and 45)
In Example 38, false plying was produced in the same manner as in Example 38, except that the number average molecular weight of polyethylene glycol, which is a copolymerization component of the island component, was changed as shown in Table 10.

Table 10 shows the evaluation results of the fiber characteristics and the fabric characteristics of the obtained fibers. Even when the number average molecular weight of polyethylene glycol was changed, there was little cracking of the sea component, and hygroscopicity, color development, leveling property, quality, and dry feeling after hot water treatment were all good.

The sea-island type composite fiber of the present invention has a fiber structure such as a woven fabric or a knitted fabric because the cracking of the sea component due to the volume swelling of the hygroscopic polymer of the island component is suppressed in the hot water treatment such as dyeing. It has excellent quality with less dyeing spots and fluffing. In addition, since the elution of the hygroscopic polymer is suppressed, it is excellent in hygroscopicity even after hot water treatment, and further, when the sea component is polyester, it also has the original dry feeling of polyester fiber. Therefore, it can be suitably used as a fiber structure such as a woven or knitted fabric for clothing or a non-woven fabric.

1. 1. Sea component 2. Island component 3. Fiber diameter 4. 4. A circumscribed circle connecting the vertices of the island components arranged on the outermost circumference. Outermost layer thickness 6. Diameter of island component 7. Weighing plate 8. Distribution plate 9. Discharge plate 10- (a). Measuring hole 1
10- (b). Measuring hole 2
11- (a). Distribution groove 1
11- (b). Distribution groove 2
12- (a). Distribution hole 1
12- (b). Distribution hole 2
13. Discharge introduction hole 14. Reduction hole 15. Discharge hole 16. Circular groove

Claims (15)

The sea component is polyester, the island component is a polymer having moisture absorption, and the polymer having moisture absorption is a polyester composed of an aromatic dicarboxylic acid and an aliphatic diol, and a polyether ester containing a polyether as a copolymerization component. Yes, in the cross section of the fiber, the ratio (T / R) of the outermost layer thickness T and the fiber diameter R is 0.05 to 0.25, and the difference in moisture absorption rate (ΔMR) after hot water treatment is 2.0 to 10 A sea-island type composite fiber characterized by being 0.0%. The outermost layer thickness is the difference between the radius of the fiber and the radius of the circumscribed circle connecting the vertices of the island components arranged on the outermost circumference, and represents the thickness of the sea component existing in the outermost layer. The sea-island type composite fiber according to claim 1, wherein the outermost layer thickness T is 500 to 3000 nm. The sea-island type composite fiber according to claim 1 or 2, wherein the diameter r of the island component in the cross section of the fiber is 10 to 5000 nm. The sea-island type composite fiber according to any one of claims 1 to 3, wherein the island component is arranged around 2 to 100 in the fiber cross section. Claim 1 is characterized in that the ratio (r1 / r2) of the diameter r1 of the island component arranged so as to pass through the center of the fiber cross section and the diameter r2 of the other island components is 1.1 to 10.0. The sea-island type composite fiber according to any one of 4 to 4. The sea-island type composite fiber according to any one of claims 1 to 5, wherein the shape of the center side of the fiber cross section is non-circular in the island component arranged on the outermost circumference. The sea-island type composite fiber according to any one of claims 1 to 6, wherein the composite ratio (weight ratio) of the sea component / island component is 50/50 to 90/10. The sea-island type composite fiber according to any one of claims 1 to 7, wherein the polyether is at least one polyether selected from the group consisting of polyethylene glycol, polypropylene glycol, and polybutylene glycol. The sea-island type composite fiber according to any one of claims 1 to 8, wherein the number average molecular weight of the polyether is 2000 to 30000 g / mol. The sea-island type composite fiber according to any one of claims 1 to 9, wherein the copolymerization rate of the polyether is 10 to 60% by weight. The polyether ester is characterized in that a polyester composed of an aromatic dicarboxylic acid and an aliphatic diol is copolymerized with a polyether and an alkylene oxide adduct of bisphenols represented by the following general formula (1). The sea-island type composite fiber according to any one of claims 1 to 10.

(However, n and m are integers of 2 to 20, and n + m are 4 to 30). The sea-island type composite fiber according to any one of claims 1 to 11, wherein the aliphatic diol is 1,4-butanediol. The sea-island type composite fiber according to any one of claims 1 to 12, wherein the sea component is a cationic dyeable polyester. A false twisted yarn obtained by twisting two or more Kaishima-type composite fibers according to any one of claims 1 to 13. A fiber structure comprising the sea-island type composite fiber according to any one of claims 1 to 13 and / or the false plying according to claim 14 as at least a part thereof.

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