JP2000314036A - Hollow false twist textured yarn and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a lightweight hollow false twist textured yarn scarcely causing convection of air in the interior of clothes, excellent in heat insulating properties and suitable for outers, etc., by carrying out false twist texturing of a specific core-sheath type conjugate fiber, then eluting a part of a water-soluble polymer arranged in the core part and forming a hollow part. SOLUTION: A core-sheath type conjugate fiber prepared by arranging a polymer such as a copolyester of a polyalkylene glycol and a metal sulfoisophthalate soluble in water at >=20 deg.C in a core part and a thermoplastic polymer such as a polyester having fiber-forming properties and comprising ethylene terephthalate as a main recurring unit in (20/80) to (50/50) conjugate ratio (wt.%) of the core part/sheath part is false twist textured and at least a part of the water-soluble polymer arranged in the core part is then eluted in a water bath at 20-140 deg.C to form a hollow part. Thereby, a hollow false twist textured yarn having 20-50% stretch recovery ratio, 20-50% percentage of hollowness of fiber cross-sectional area and a dead air structure in which the hollow part does not communicate with the outside air except the fiber ends is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is lightweight and excellent in heat retention, can be suitably used for outerwear, innerwear and sportswear, and has a high degree of hollowness. The present invention relates to a hollow false twisted yarn that is difficult to perform and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, hollow fibers have been used to obtain a material that is lightweight and has excellent heat retention. In recent years, fibers with a higher hollow ratio have been developed in pursuit of a higher degree of heat retention and lightness, but when such a fiber with a higher hollow ratio is subjected to false twisting, the hollow portion is crushed. Therefore, there is a disadvantage that the heat retention is greatly reduced. For this reason, as proposed in Japanese Patent Application Laid-Open No. 10-292233, there is a method of preventing collapse of the hollow portion during false twisting by using fibers having a circular cross section, but the hollow portion was divided into four. It is difficult to make the hollow ratio higher than 20% because of the cross section
Furthermore, even if the cross section is a hollow, there is a problem that the hollow portion is crushed unless the number of twists is reduced, since the hollow portion is hollow. result,
The expansion / contraction restoration rate was low, and was not satisfactory as a processed yarn. In order to achieve both a high hollow ratio and a high elasticity restoration ratio, for example, as proposed in JP-A-5-72026 and JP-A-9-59834, or as proposed in JP-A-10-280269, After performing false twisting using a core-sheath composite fiber with an eluting component disposed in the core, eluting and eluting the eluting component with an alkali solution treatment, etc., the cross-sectional deformation is suppressed even at a high twist number despite a high hollow ratio. A method for obtaining a hollow false twisted yarn is known.

However, in any of the proposals, the elution of the eluted components is performed through fine through-holes, cracks, cracks, and the like from the hollow portion to the fiber surface, so that the hollow portion communicates with the outside air through these through holes and the like. A certain so-called open air structure causes problems such as poor heat retention due to convection of air inside the garment, fibrillation due to micropores, grooves, cracks and the like, and a decrease in yarn strength.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a high hollow false twisting process having a dead air structure having no through holes, grooves, sheath cracks, etc., and a high expansion / recovery recovery rate. To provide yarn. Here, the dead air structure is a structure in which the hollow portion of the hollow fiber does not communicate with the outside air except for the end of the fiber, and it is difficult for air to convect inside the garment, which is lightweight and extremely effective as a heat insulating and heat insulating material.

[0005]

An object of the present invention is to provide a method for manufacturing a semiconductor device, wherein the sheath is made of a thermoplastic polymer having substantially one kind of fiber-forming property, the elasticity of elasticity is 20 to 50%, and the hollowness of the fiber cross-sectional area is reduced. The hollow false twisted yarn is characterized in that the hollow portion has a dead air structure that does not communicate with the outside air except for the fiber ends.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic polymer having a fiber-forming property used as a sheath in the present invention includes polyolefins such as polyethylene and polypropylene, polyamides such as nylon 6 and nylon 66, polyethylene terephthalate, polybutylene terephthalate, and the like. Polyesters such as polypropylene terephthalate, polylactic acid,
Examples thereof include aliphatic polyesters such as polyglycolic acid, but are not particularly limited as long as they can be melt-spun and have a fiber-forming property.

[0007] Among these polymers, a polyester having ethylene terephthalate as a main repeating unit, which is the most versatile synthetic fiber for clothing, is most preferably used. In this case, in order to maintain the mechanical properties of the fiber, it is preferable that 70 mol% or more be composed of repeating units of ethylene terephthalate, but other components may be copolymerized as long as the object of the present invention is not impaired. . For example, compounds that can be used in place of terephthalic acid include:
Aromatic or aliphatic such as isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium isophthalic acid , Alicyclic dicarboxylic acids and their derivatives. Diol compounds that can be used in place of ethylene glycol include propylene glycol, butylene glycol, tetramethylene glycol,
Aromatic, aliphatic and alicyclic diol compounds such as 1,4-cyclohexanedimethanol, diethylene glycol, neopentyl glycol, polyalkylene glycol, bisphenol A and bisphenol S can be mentioned. In addition, these polymers may contain a functional agent such as a matting agent, an antistatic agent, and a deodorant as needed.

[0008] The stretch recovery ratio of the hollow false twisted yarn of the present invention is 20.
~ 50%, preferably 25-45%, most preferably
30-40%. The expansion / contraction restoration ratio is a value indicating the crimping property of the false twisted yarn, and a higher value means a higher bulk performance. This expansion restoration ratio can be measured by the following method. In other words, a 10-turn razor with a razor length of 40 cm is taken with a razor, and the fold is folded into a figure eight shape to make a small rivet. It is immersed in a hot water bath at 90 ° C for 20 minutes without tension and allowed to dry naturally for about 24 hours. afterwards,
Apply an initial load of 0.002 g / d and a constant load of 0.1 g / d
Immerse in a water bath at 25 ° C, measure the length of the scab 2 minutes later, and use this as the original length. Next, gently remove the constant load only, measure the length of the scab after 2 minutes with only the initial load, and express the recovered length as a percentage of the original length.

[0009] When the elasticity recovery ratio is less than 20%, the rigidity of the crimp is low and only the same stretchability as that of raw silk can be exhibited, so that it is not suitable for use as a processed yarn.
In addition, in order to increase the elasticity recovery ratio to more than 50%, the number of twists and the temperature of the hot plate must be increased more than necessary, resulting in a processed yarn excellent in crimping performance. Undesirable characteristics such as a decrease in fibril resistance are observed.

[0010] The hollow ratio of the fiber cross-sectional area according to the present invention is an area ratio of a hollow portion calculated from a micrograph of a cross section perpendicular to the fiber axis direction. The hollow ratio needs to be 20 to 50%, preferably 25 to 45%, more preferably 30 to 50%.
40%. If the hollow ratio is less than 20%, the lightness and heat retention are insufficient. If the hollow ratio exceeds 50%, the fiber occupies a substantially low proportion, which results in lower strength, and the thickness of the sheath becomes thinner. Disadvantages occur, which is not preferable.

What is important in the hollow false twisted yarn of the present invention is that the hollow portion has a dead air structure that does not communicate with the outside air except for the fiber ends. As described above, the hollow fiber produced by eluting the polymer disposed in the core through micropores, cracks, cracks, etc., which penetrate to the surface layer of the fiber, has a heat insulation property that the hollow fiber has because the outside air can freely enter and exit the hollow. There is a drawback that the property is greatly reduced. In addition, fibers in which through-holes, cracks, cracks, and the like are present in the surface layer of the fibers have a problem in that the quality of the fabric is deteriorated, such as occurrence of fibrillation when a fiber product is used. In other words, from the viewpoint of heat retention and maintenance of the quality of the fabric, it is indispensable in the present invention that the hollow portion has a dead air structure that does not communicate with the outside air except for the fiber ends.

The hollow false twisted yarn of the present invention has a core / sheath portion in which a water-soluble polymer soluble in water at a temperature of 20 ° C. or more is provided in a core portion and a fiber-forming thermoplastic polymer is provided in a sheath portion. After false-twisting a core-sheath composite fiber having a composite ratio (% by weight) of 20/80 to 50/50, at least a part of the water-soluble polymer disposed in the core is eluted in a water bath at 20 to 140 ° C. Thus, a hollow portion can be formed and manufactured.

The water-soluble polymer constituting the core is an indispensable component for suppressing the cross-sectional deformation of the fiber and producing a high hollow when false twisting is performed. The water-soluble polymer used for the core is a polymer that can be melt-spun and is not particularly limited as long as it is a polymer that is soluble in water at 20 ° C. or higher. Here, the water-soluble polymer is 100 ml of water at 20 ° C.
In which 1 g or more of the polymer is dissolved.

Specific examples of such polymers include polyalkylene glycol and sulfoisophthalic acid metal salt copolymerized polyester, polyalkylene glycol copolymerized polyester, polyvinyl alcohol-based polymer, and water-soluble polyamides. From the viewpoints of spinnability, processability and water solubility, preferred are polyalkylene glycol and sulfoisophthalic acid metal salt copolymerized polyester, and polyalkylene glycol copolymerized polyester. Particularly preferably used water-soluble polymers are copolymers of polyalkylene glycol and aromatic dibasic acid, and polyalkylene glycol and aliphatic dibasic acid.

A conventionally known melt spinning method can be applied to the core-sheath type conjugate fiber from the above-mentioned core-sheath polymer, and the spinning conditions are appropriately set according to the properties of the core-sheath portion.

The core / sheath composite ratio must be between 20/80 and 50/50. If the core is less than 20%, the heat retention and lightness are not sufficient as a hollow fiber, and if it exceeds 50%, the ratio of the sheath decreases, which may cause problems in physical properties such as yarn strength and elongation. is there.

Regarding the conditions for false twisting, the hot plate temperature was set at 100
The temperature is preferably set to ~ 220 ° C. It is necessary that the elasticity of the obtained processed yarn is 20 to 50%. Expansion and contraction restoration rate
If it is less than 20%, the bulkiness is insufficient and the performance as a false twisted yarn cannot be sufficiently exhibited. On the other hand, if it exceeds 50%, problems such as crushing of the core and cracking of the sheath occur during false twisting. Here, in order to set the expansion / contraction restoration rate to 20 to 50%, the false twist coefficient is calculated according to the total denier of the multifilament by the expression “K = T *
D ^1/2 ". Here, K is the false twist coefficient, T is the number of twists, and D is the total denier of the multifilament. For example, multifilament total denier is 75
In the case of D, it is preferable that the false twisting process be performed at a false twist coefficient K of 20,000 to 30,000.

The hollow false twisting of the present invention is obtained by subjecting the core-sheath type composite false twisted yarn obtained under the above conditions to elution of the core with water and hot water or an aqueous alkaline solution. be able to. The water-soluble polymer can be eluted through the polymer layer of the sheath by the action of partial dissolution, partial melting, hydrolysis, and the like in the core, and in fact, the sheath can be hollow without cracking.

The elution of the core may be carried out with water at 20 to 140 ° C., but from the viewpoint of shortening the elution time and completely eluting the core, it is more preferably carried out with hot water at 70 ° C. or higher. The elution treatment may also serve as a scouring and liquid flow relaxing step.
In addition, the hot water may be an aqueous alkali solution, and may also serve as an alkali reduction processing step. Further, the dyeing step may also serve as the elution step. In any step, the core component can be eluted and can be sufficiently removed. Therefore, it is not necessary to form through-holes, cracks, cracks, and the like in the sheath for the purpose of elution. If such penetrating micropores, grooves, cracks, etc. are present, as described above, the obtained hollow fiber has an open air structure in which the hollow portion and the outside air communicate with each other, so that convection of air is likely to occur and heat retention is improved. This causes problems such as lowering, fibrillation and yarn strength. Further, when the core portion is exposed to the fiber surface layer as in the C-shaped fiber cross section, the water-soluble polymer directly touches the hot plate at the time of false twisting, the polymer melts, and the number of twists increases. As a result, a problem such as a large amount of melting from the cracks occurs, and a desired hollow fiber cannot be obtained. Therefore, the configuration of the present invention is indispensable for expressing a hollow fiber having both a high elasticity restoration rate and a high hollow rate, and exhibits an effect of suppressing cross-sectional deformation of the fiber during false twisting. is there.

[0020]

The present invention will be specifically described below with reference to examples. Example 1 A polyethylene glycol water-soluble polyester (PAOGEN PP-150 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was used for the core and polyethylene terephthalate was used for the sheath, and the composite ratio was core / sheath:
30/70 concentrically arranged, conjugate spinning at a spinning speed of 3000 m / min to obtain 140D-24f core-sheath conjugate fiber, and then draw false twisting with a vertical drawing false twisting machine Was. The false twisting was performed under the conditions of a twist coefficient K = 27000 and a hot plate temperature of 180 ° C. The obtained processed yarn was 75D-24f and had an elasticity recovery ratio of 33%. After weaving the processed yarn into a plain weave to obtain a greige machine, 2 g / l of sodium carbonate and 0.2 g / l of a surfactant (Gran Up US-20) were used as auxiliaries.
The greige was treated for 30 minutes in a 90 ° C. hot water bath in which was dissolved. Observation of the fiber cross section with a microscope and sensory evaluation were performed on the obtained fabric sample. The hollow ratio (area ratio between the core and the sheath) in the cross section of the hollow fiber was 30%. Table 1 shows the evaluation results.
Shown in

In the case of this example, the heat retaining property, the light weight property and the bulkiness were all excellent. Example 2 A core / sheath composite fiber was obtained in the same manner as in Example 1 except that the composite ratio of each polymer component was changed to core / sheath: 40/60. Thereafter, the same false twisting as in Example 1 was performed except that the twist coefficient was changed to K = 24000, to obtain a weaving machine after weaving. Thereafter, the same high-order processing as in the first embodiment is performed.
In the same manner as in the above, fiber cross-section observation and sensory evaluation were performed. The expansion / contraction restoration ratio of the processed yarn is 27%, and the hollow ratio in the cross section of the hollow fiber is
39%. Table 1 shows the evaluation results.

In this example, the lightness and the heat retention were particularly excellent. Example 3 The composite ratio of each polymer component was changed to core / sheath: 20/80,
A fabric was obtained in the same manner as in Example 1 except that the twist coefficient was changed to K = 30,000, and a fiber cross-section observation and a sensory evaluation were performed. The stretch ratio of the processed yarn was 40%, and the hollow ratio in the cross section of the hollow fiber was 20%. Table 1 shows the evaluation results.

In this example, although lightness and heat retention were somewhat inferior to those of Examples 1 and 2, it was particularly excellent in bulkiness. Example 4 A fabric was obtained in the same manner as in Example 1 except that nylon 6 was used for the sheath, and the fiber cross section was observed and the sensory evaluation was performed. The expansion / contraction restoration ratio of the processed yarn was 34%, and the hollow ratio in the cross section of the hollow fiber was 25%. Table 1 shows the evaluation results.

In this example, the hollow ratio is slightly lower than when polyethylene terephthalate is provided in the sheath. Comparative Example 1 A fabric was obtained in the same manner as in Example 3 except that the composite ratio of each polymer component was changed to core / sheath: 10/90, and fiber cross-section observation and sensory evaluation were performed. The elasticity of the processed yarn is 41
%, And the hollow ratio in the cross section of the hollow fiber was 10%. Table 1 shows the evaluation results.

In this example, the bulkiness was excellent, but the hollow ratio was too small, resulting in poor lightness and heat retention. Comparative Example 2 The composite ratio of each polymer component was changed to core / sheath: 60/40,
A fabric was obtained in the same manner as in Example 1 except that false twisting was performed with a twist coefficient K of 20,000. Fiber cross-section observation and sensory evaluation were performed. The expansion / contraction restoration ratio of the processed yarn was 22%, and the hollow ratio in the cross section of the hollow fiber was 55%. Table 1 shows the evaluation results.

In this example, since the ratio of the sheath portion was low, the sheath strength was poor, and the sheath was cracked by false twisting. Comparative Example 3 A fabric was obtained in the same manner as in Example 3, except that the twisting coefficient was set to K = 33000 and false twisting was performed, and fiber cross-section observation and sensory evaluation were performed. The stretch recovery ratio of the obtained processed yarn was 59%, and the hollow ratio in the cross section of the hollow fiber was 11%. Table 1 shows the results.

In this example, since the number of twists was too high, the core portion was crushed at the time of false twisting, so that the hollow ratio was small and the heat retention was poor. Comparative Example 4 A fabric was obtained in the same manner as in Example 3 except that false twisting was performed with the twist coefficient set to K = 10000, and fiber cross-section observation and sensory evaluation were performed. The expansion / contraction restoration ratio of the processed yarn was 14%, and the hollow ratio in the cross section of the hollow fiber was 20%. Table 1 shows the results
Shown in

In this example, since the number of twists was small and the sweet twist, the elasticity recovery rate was low and the bulkiness was poor. Comparative Example 5 A composite fiber was obtained by spinning in the same manner as in Example 1 except that the die was changed to a C type. In this example, as mentioned earlier,
Because the water-soluble polymer in the core is exposed on a part of the fiber surface layer, the water-soluble polymer melts by directly touching the hot plate during false twisting, and when the number of twists is increased, it melts in large quantities from cracks. Since the core part is crushed without being able to suppress the cross-sectional deformation of the fiber, the twisting coefficient is set to K = 10000 and false twisting is performed. Obtained fiber observation and sensory evaluation were performed. The stretch recovery ratio of the processed yarn was 13%, and the hollow ratio in the cross section of the hollow fiber was 28%. Table 1 shows the results.

Since the obtained hollow fiber had a C-shaped cross section, it had poor heat retention due to the open air structure.

[0030]

[Table 1]

[0031]

EFFECT OF THE INVENTION The hollow false twisted yarn having both a high elasticity recovery ratio and a high hollowness ratio of the present invention has excellent lightness, heat retention, and bulkiness, and can be used in a wide range of clothing applications. it can.

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Claims (3)

[Claims] (1) the sheath portion is substantially made of a thermoplastic polymer having a kind of fiber forming property, the elasticity recovery ratio is 20 to 50%, and the hollow ratio of the fiber cross-sectional area is 20 to 50%; The hollow false twisted yarn, wherein the hollow portion has a dead air structure that does not communicate with the outside air except for the fiber end. 2. The hollow false twisted yarn according to claim 1, wherein the sheath thermoplastic resin is a polyester having ethylene terephthalate as a main repeating unit. 3. A core-soluble polymer which is soluble in water at 20 ° C. or higher, a sheath-forming thermoplastic polymer having a fiber-forming property, and a core / sheath composite ratio (weight%) of 20 /%. 80-50
After false-twisting the core-in-sheath type composite fiber consisting of / 50, at least a part of the water-soluble polymer disposed in the core is heated to 20 to 140 ° C.
A method for producing a hollow false twisted yarn, comprising forming a hollow portion by eluting in a water bath.