JPH0633319A - Hollow conjugate yarn and its production - Google Patents

Abstract

(57) [Summary] [Structure] A polyester-based polymer part containing inorganic fine particles has a cross-sectional shape in which a specific fiber-forming polymer part is completely surrounded, and the polyester-based polymer part and the fiber. Hollow composite fiber having an annular void between the forming polymer part, and the polyester polymer as a core component,
A method for producing a multi-core core-sheath type composite fiber comprising the fiber-forming polymer as a sheath component, which is treated with an alkali to remove a part of the polyester-based polymer in the composite fiber. [Effect] The hollow composite fiber of the present invention has excellent sag resistance, water absorption, heat retention, light weight, flexibility, has a good texture with swelling, and has no gloss unevenness. Further, such a conjugate fiber can be smoothly produced without causing any trouble in the processability of fiberizing process and the processability of alkali treatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention provides a polyester polymer part containing inorganic fine particles, which has a fiber-forming polymer part which has a slower alkali decomposition rate or does not decompose into alkali than the polyester polymer part. The present invention relates to a conjugate fiber having an enclosed cross-sectional shape and having a hollow portion between the two polymers. In detail, it has an ultraviolet shielding property depending on the type of inorganic fine particles to prevent sunburn due to sunlight, and it can give a refreshing feeling in the midsummer and a heat retaining property in severe cold, and also has water absorption, a lightweight feeling, swelling, etc. And a method for producing the same.

[0002]

2. Description of the Related Art Synthetic fibers such as polyester and polyamide are widely used not only for clothing but also for industrial purposes due to their excellent physical and chemical properties, and have industrially important value. There is. However, these synthetic fibers have a high monofilament fineness and a simple cross-sectional shape, so that they are more monotonous in texture and luster than natural fibers such as silk, cotton, and hemp. Further, these synthetic fibers were poor in water absorption, had a cold and slimy feel, and were of low quality. Therefore, in order to improve the above-mentioned drawbacks of synthetic fibers, it has been widely practiced that a plurality of polymers are compounded into fibers, the cross-sectional shape of synthetic fibers is modified, and the fibers are hollowed. . Also,
In order to impart various properties to the fiber, inorganic fine particles are selected according to the purpose, and the inorganic fine particles are used as a fiber-forming polymer.
It is frequently performed that a large amount is kneaded and spun.

[0003]

However, the fiber containing inorganic fine particles thus obtained contains a large amount of inorganic fine particles and is therefore heavy, and further, lacks bulge and is unsuitable for the field of clothing requiring a lightweight feeling. Met. Further, in the case of hollow fibers, it is generally performed by spinning from a hollow spinning nozzle. However, even if a hollow structure is once imparted to the fibers, the polymer in a molten state can be formed before it solidifies. It was difficult to produce hollow fibers having a high hollow ratio because the ratio of hollow portions was easily reduced due to surface tension, take-up tension during spinning and the like. Further, conventionally known hollow fibers made of polyester or polyamide alone have a low water absorption property, and cannot be uncomfortable because they are cold and have a slimy feel.

Recently, a core-sheath type composite fiber having polyamide as a sheath component and polyester as a core component is treated with alkali to decompose and remove the surface portion of the polyester core component with alkali to remove the polyamide sheath component and the polyester. A core-sheath type composite fiber in which a hollow portion is formed between the core component and the core component has been proposed (JP-A-3-124857). However, since this composite fiber has only one core, the fiber is liable to be fragile and is not satisfactory in heat retention, water absorption, soft feeling, swelling and the like. An object of the present invention is to provide a composite fiber which is lightweight despite having inorganic fine particles and has high heat retention, water absorption, soft feeling, swelling and the like. Further, since it contains the inorganic fine particles, it is an object of the present invention to provide a composite fiber in which each performance is given depending on the type of the inorganic fine particles.

[0005]

That is, the present invention provides a fiber-forming polymer in which a polyester polymer part containing inorganic fine particles has a slower alkali decomposition rate than the polyester polymer part or does not decompose into alkali. The part has a cross-sectional shape that completely surrounds, and there is a hollow part between the polyester-based polymer part and the fiber-forming polymer part,
A hollow conjugate fiber which is a multi-core sheath-type conjugate fiber having two or more cores and which satisfies the following formulas (I) and (II):

0.3 × T ≦ B ≦ 0.9 × T (I)

20 ≦ 100− {B / (T−A)} × 100 <100 (II)

In the above formulas (I) and (II), T: cross-sectional area of the composite fiber including the hollow portion A: fiber-forming polymer occupying the cross-sectional area of the composite fiber
Area B: The area of the polyester polymer part in the cross-sectional area of the composite fiber.

According to the present invention, a multi-core core-sheath type composite fiber having a fiber-forming polymer as a sheath component and a polyester-based polymer as a core component is alkali-reduced to give a polyester-based polymer in the composite fiber. It is a method for producing the above-mentioned hollow composite fiber by removing a part.

In the composite fiber of the present invention, the space between the polyester polymer part and the fiber-forming polymer part is usually
It is in the form of an annular hollow channel communicating with the fiber axis direction, and there are two or more annular hollow channels.

Polyester type polymer used in the present invention
As (hereinafter, referred to as PES-based polymer), those which are easily decomposed and removed by an alkali and have good fiber-forming property are preferable. Examples of such PES-based polymer include terephthalic acid, isophthalic acid, naphthalene-
Aromatic dicarboxylic acids such as 2,6-dicarboxylic acid, phthalic acid, α, β- (4-carboxyphenoxy) ethane and 4,4′-dicarboxydiphenyl, and aliphatic dicarboxylic acids such as adipic acid and sebacic acid An acid or an ester thereof is used, and ethylene glycol, diethylene glycol, 1,4-butanediol, 1,6 is used as a diol component.
-Hexanediol, neopentyl glycol, cyclohexane-1,4-dimethanol, polyethylene glycol, tetramethylene glycol, and the like can be cited as fiber-forming polyesters. Polyesters composed of ethylene terephthalate units are preferred.

In the above PES-based polymer, 5-
Isophthalic acid having a metal sulfonate group such as sodium sulfoisophthalic acid and 5-potassium sulfoisophthalic acid; polyoxyalkylene glycol such as polyoxyethylene glycol and polyoxytetramethylene glycol
Polyoxyethylene glycol-methyl-glycidyl ether, polyoxyethylene glycol-methyl-
Approximately 2 parts of the third component such as polyoxyalkylene glycol blocked at one end such as 2,3-dihydroxypropyl ether.
To 20 mol% of PES-based polymer
Is particularly preferable because it can be easily decomposed and removed with an alkali.

The PES polymer can be obtained by any production method. For example, polyethylene terephthalate can be explained by direct esterification reaction between terephthalic acid and ethylene glycol, or transesterification reaction between a lower alkyl ester of terephthalic acid such as dimethyl terephthalate and ethylene glycol. Or the reaction of terephthalic acid with ethylene oxide to produce a glycol ester of terephthalic acid and / or its low polymer, followed by heating such product under reduced pressure to the desired product. It is easily produced by a second stage reaction in which a polycondensation reaction is performed until the degree of polymerization is reached.

The inorganic fine particles added to the above PES-based polymer are not limited in kind as long as they are not decomposed by an alkali, that is, as long as they are alkali resistant inorganic fine particles.
For example, when the purpose is to obtain an ultraviolet-shielding fiber, inorganic fine particles that reflect or absorb ultraviolet light, that is, inorganic fine particles that do not substantially transmit ultraviolet light can be used. Specific examples thereof include titanium dioxide, manganese dioxide, zirconium oxide, zinc oxide, magnesium oxide,
Inorganic fine particles such as alumina, silicon dioxide, barium sulfate, calcium carbonate, sodium carbonate, talc, and kaolin, or those obtained by subjecting these inorganic fine particles to various treatments, may be used alone or in admixture of two or more. You can Among these, titanium dioxide, zinc oxide and alumina are preferable, and titanium dioxide is particularly preferable.

In order to impart the ultraviolet shielding effect, the amount of the inorganic fine particles added is preferably 5% by weight or more based on the PES polymer. The upper limit of the amount of the inorganic fine particles added is not particularly limited, but 85% by weight from the viewpoint of spinnability.
The following is preferable, and the range of 10 to 70% by weight is particularly preferable. The average particle size of the inorganic fine particles is preferably 5 μm or less, and particularly preferably 1 μm or less. If the average particle size is too large, problems such as filter clogging during spinning and yarn breakage occur, and yarn breakage also occurs during drawing, which is not preferable. The average particle size referred to here is a particle size distribution measuring device (CAPA-50, manufactured by Horiba Ltd.).
It is a value measured using 0).

In the present invention, it is preferable to add a compound such as a metal salt of stearic acid or a titanium coupling agent to the PES polymer containing inorganic fine particles in order to enhance spinnability, particularly magnesium stearate, Calcium stearate, zinc stearate and the like are preferable. Magnesium stearate is preferred when the inorganic fine particles are titanium dioxide or those containing titanium dioxide. And the addition amount of these compounds is 1 to 1 with respect to the inorganic fine particles.
It is preferably in the range of 0% by weight.

The fiber-forming polymer which is another component of the present invention is a polymer which has an extremely slow alkali decomposition rate or does not decompose into alkali at all as compared with the above-mentioned PES polymer. As a matter of course, a polymer which allows an aqueous alkali solution to pass through and is hardly alkali-decomposed under the alkali-decomposition treatment conditions is preferably used, and specific examples thereof include polyamide, polyether polyurethane and polyethylene. Among them, polyamide is most suitable because the hollow portion can be easily formed. Polyamide is particularly excellent when used for clothing because it has water absorbability and is excellent in dyeability. Polyamide is nylon 4, nylon 6, nylon 610, nylon 6
6, a polyamide mainly composed of nylon 12, etc.,
A polyamide containing a small amount of the third component may be used. These may contain a small amount of additives, optical brighteners, stabilizers and the like. When a copolyester in which the third component is copolymerized is used as the PES-based polymer, a polyester in which the copolymerization ratio of the third component is smaller than that of the former can be used as the fiber-forming polymer.

In the present invention, a multi-core core-sheath type composite fiber having a PES polymer as a core component and a fiber-forming polymer as a sheath component is formed from the above PES polymer and the fiber-forming polymer, or After forming a yarn or a fiber product containing the conjugate fiber as a constituent, a part of the PES polymer in the conjugate fiber, that is, the surface portion is decomposed and removed by alkali treatment to remove the PES polymer portion and the fiber forming property. A composite fiber having a hollow part between the polymer part, a yarn or a fiber product made of the composite fiber is produced.

In the present invention, a fiber-forming polymer having low degradability against alkali such as polyamide is used as a sheath component, and a PES-based polymer is used as a core component. The fibers can be formed extremely easily, and a part of the PES-based polymer can be selectively decomposed and removed by the alkaline liquid having a relatively low concentration and a low temperature without decomposing the fiber-forming polymer. Moreover, the low-polymerization product of the PES-based polymer generated by the alkali decomposition is dissolved in the alkaline solution and easily passes through the fiber-forming polymer, so that it does not remain in the formed hollow composite fiber. Further, since a hollow composite fiber can be obtained by treating with an alkaline solution having a relatively low concentration and low temperature, troubles such as yellowing of the obtained hollow composite fiber hardly occur.

The composite ratio of the PES-based polymer and the fiber-forming polymer in the raw material composite fiber is the area ratio of the cross section of the fiber, and PES-based polymer: fiber-forming polymer = 9.
It is preferably in the range of 0:10 to 30:70, particularly 70:30 to 40:60. When the composite ratio of the fiber-forming polymer is less than 10%, the composite ratio becomes unbalanced and the spinnability is liable to be poor. On the other hand, when it exceeds 70%, the hollow composite fiber obtained has a low hollow ratio, and the inorganic content is low. Fibers containing fine particles tend to be insufficient in flexibility, lightness, bulkiness, heat insulation and the like. The monofilament fineness of the composite fiber is preferably 5 denier or less, particularly 0.2 to 3 denier in order to obtain a fiber having flexibility, lightness, swelling and the like. The conjugate fiber can be produced by a method such as melt-composite spinning or melt-composite spinning drawing which is usually employed when producing a sea-island type conjugate fiber.

The composite state of each component in the composite fiber before alkali treatment is such that the PES polymer constitutes the core component,
Any shape may be used as long as the fiber-forming polymer constitutes the sheath component. A typical example of the multicore-core-sheath type composite fiber before the alkali treatment is shown by its cross-sectional view, and FIG. 1 can be given. In the multicore-core-sheath type composite fiber shown in FIG. 1, the core component 1 of the PES-based polymer containing a plurality of inorganic fine particles having substantially the same shape and size is non-uniformly dispersed in the sheath component 2 of the fiber-forming polymer. is doing. It is preferable to appropriately select the ratio of the total area of all the core components 1 and the area of the sheath components 2 in the cross section of the fiber from the above range of the composite ratio. The shape, the number, the distribution state of the core component, the contour (outer shape) of the sheath component, etc. can be appropriately changed according to each situation.

The cross-sectional shape (outer shape) of the multicore-core-sheath composite fiber may be any shape, and various irregular shapes other than the circular shape shown in FIG. In the case of the irregular cross section, for example, any shape such as a flat shape, an elliptical shape, a polygonal shape such as a triangular shape to an octagonal shape, a T shape, and a multilobe shape such as 3 to 8 leaves can be used.

The hollow composite fiber of the present invention, or the yarn or the cloth containing the fiber as a constituent, is obtained by subjecting the above-mentioned composite fiber, or a thread containing the fiber as a constituent, or a fiber product such as a cloth to an alkali treatment. And other textile products can be manufactured. In the alkali treatment, the ratio of the hollow portion formed between the fiber forming polymer portion and the inorganic fine particle-containing PES polymer portion is represented by the following formula (I) and formula (II).

0.3 × T ≦ B ≦ 0.9 × T (I)

20 ≦ 100− {B / (T−A)} × 100 <100 (II)

In the above formulas (I) and (II), T: cross-sectional area of the composite fiber including the hollow portion A: fiber-forming polymer occupying the cross-sectional area of the composite fiber
Area B: It is necessary to adjust the alkali concentration of the alkali solution, temperature, treatment time, etc. so as to satisfy the area of the polyester polymer part in the cross-sectional area of the composite fiber.

In carrying out the alkali treatment, an aqueous alkali solution such as an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, or an alkaline earth metal hydroxide such as calcium hydroxide or magnesium hydroxide is used. In particular, an alkali aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is preferable. The alkali concentration in the alkaline aqueous solution varies depending on various requirements such as the single fiber fineness of the composite fiber, the ratio of island components in the composite fiber, and the type of PES-based polymer constituting the composite fiber. For example, an aqueous sodium hydroxide solution is used. In this case, it is preferable to use an aqueous solution having a sodium hydroxide concentration of 5 to 50 g / liter.

When a quaternary ammonium salt is further allowed to coexist in the above-mentioned alkaline aqueous solution, the removal of the PES-based polymer due to alkali erosion is promoted, the alkali treatment time is shortened, and the alkali concentration in the alkaline aqueous solution is reduced. Can be reduced. The quaternary ammonium salt has a general formula:

[N (R ↑ 1) (R ↑ 2) (R ↑ 3) (R
↑ 4)] ↑ + X ↑-(wherein R ↑ 1, R ↑ 2, R ↑ 3 and R ↑ 4 may be the same or different from each other, an alkyl group, a phenyl group, an alkyl group-substituted phenyl group or A quaternary ammonium salt represented by a phenyl group-substituted alkyl group and X represents a halogen element). Preferred specific examples of the quaternary ammonium salt include benzyldimethyldodecylammonium chloride, benzyldimethyldodecylammonium bromide and cetyltrimethylammonium chloride. It is usually desirable to use the quaternary ammonium salt at a rate of 0.2 to 2 g / liter.

Partial decomposition and removal of the PES-based polymer by alkali erosion may be performed directly on the composite fiber itself before forming the fiber product such as yarn or cloth, or from the composite fiber to the fiber product such as yarn or cloth. After the formation, the yarn or the textile product may be processed. From the viewpoint of easiness of alkali erosion treatment and handleability of the obtained hollow composite fiber or product, it is desirable to carry out alkali treatment after forming a fiber product such as yarn or cloth from the composite fiber.

The temperature at the time of alkali erosion and the treatment time are the fiber fineness of the composite fiber, the ratio of the core component in the composite fiber, the type of PES polymer constituting the composite fiber, the hollow ratio in the target hollow composite fiber, the It can be appropriately adjusted depending on various requirements such as the presence or absence of the quaternary ammonium salt and the amount thereof, the content of the fiber product such as the cloth formed from the composite fiber, and the like.
For example, when alkali treatment is performed without using a quaternary ammonium salt, the temperature of the alkaline aqueous solution is 80 to 100 ° C.
It is better to process for 1 to 5 hours. When the quaternary ammonium salt is used, the temperature of the alkaline aqueous solution is 70
It is advisable to carry out the treatment at 90 ° C. for 1 to 3 hours. Examples of the alkali treatment method include a method of immersing the composite fiber, yarn or fiber product in an alkaline aqueous solution, and a method of applying and spraying an alkaline aqueous solution on them with a pad, a spray, a shower or the like.

By the above-mentioned alkali treatment, a part of the PES polymer which is the core component in the composite fiber is decomposed and removed from the surface part thereof, and the hollow composite fiber of the present invention, that is, the fiber-forming polymer part and the inorganic part. A hollow portion is provided between the fine particle-containing PES polymer portion and the hollow portion communicates with the fiber axis direction, and a hollow composite fiber having a specific hollow ratio is formed.

In the present invention, the hollow ratio between the fiber-forming polymer portion and the inorganic fine particle-containing PES polymer portion is set within the range satisfying the above formulas (I) and (II). It is possible to obtain a hollow composite fiber which has various properties depending on the type of the inorganic fine particles, heat retention (heat insulation), lightness, flexibility, swelling feeling and the like. Here, the above formula (II): 10
When the hollow ratio represented by 0- {B / (TA)} × 100 is less than 20, heat retention, lightness, flexibility, swelling and the like are lacking, while the hollow ratio is 100. That is, when the PES-based polymer is completely decomposed and removed and does not remain in the fiber, the elastic modulus of the fiber decreases and the sag resistance decreases. The hollow ratio represented by the formula (II) is 30 to 80.
It is preferable that it is within the range of, especially within the range of 50 to 70. At that time, (area of fiber-forming polymer part occupying in cross-sectional area of hollow composite fiber): (total of area of PES polymer part and hollow part occupying in cross-sectional area of hollow composite fiber) = 10: 90 to 70:30 is desirable.

Illustrating a specific example of the cross-sectional shape of the hollow conjugate fiber of the present invention, for example, the hollow conjugate fiber of FIG. 2 obtained from the conjugate fiber shown in FIG. 1 can be mentioned. From the multicore-core-sheath type composite fiber of FIG. 1, a plurality of annular hollow portions 3 having substantially the same shape and size in the sheath component 2 of the fiber-forming polymer, and a PES system containing reduced inorganic fine particles. Hollow composite fibers are formed in which each of the polymer core components 4 is substantially uniformly dispersed.

The hollow conjugate fiber of the present invention is not limited to the one shown in FIG. 2, and the number, position, shape, outer contour of the fiber and the like of the reduced core component are the cores in the above-mentioned multicore-core-sheath composite fiber. It can be made arbitrary by appropriately changing the number, position, shape of the components, the outer contour of the fiber and the like.

In the hollow composite fiber of the present invention, inorganic fine particles are independently present in the hollow portion formed between the fiber-forming polymer and the PES-based polymer, or the PES-based polymer portion and the hollow portion are hollow. Since it is a multi-core sheath-sheath type composite fiber having most of the exposed surface at the boundary surface with the hollow part and having two or more cores, there is no feeling of fatigue of the fiber due to the formation of the hollow part,
There is a feeling of repulsion even if it has a hollow portion. Further, the hollow composite fiber of the present invention forms a multi-core sheath structure, that is, the hollow portion has two
Since it is formed above, compared to the case where there is one hollow part,
Inorganic fine particles are less unevenly distributed in the hollow composite fiber, and uneven gloss is unlikely to occur. Further, the coloring property of the dyed product is not significantly deteriorated.

The fibers and yarns referred to in the present invention include long fibers such as monofilaments, short fibers such as staples, filament yarns, spun yarns, hole-composite fibers and natural fibers of the present invention, semisynthetic fibers, and others. Mixed yarns and blended yarns with synthetic fibers, plied yarns,
Any other processed yarn such as entangled yarn and crimped yarn may be used. Further, the fiber product of the present invention may be any of knitted fabrics, non-woven fabrics, final garments, fiber products such as towels and the like formed with a part or all of the fibers and threads. The hollow composite fiber of the present invention is a woven fabric such as taffeta, decin, jozzet, crepe, processed yarn, twill and the like, due to its heat retention, lightness, flexibility, swelling feeling and other characteristics such as sag resistance. Suitable for knitting, interlock, tricot, etc.

[0038]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. In the examples, each physical property value was measured by the following methods. (1) Intrinsic viscosity [η] It is an intrinsic viscosity (dl / g) measured at 30 ° C. using a mixed solvent of tetrachloroethane: phenol = 1: 1. (2) Weight loss rate (%) It was calculated by the following formula. Weight loss rate (%) = {(N ↓ 1-N ↓ 2) / N ↓ 1} × 10
0 N ↓ 1: absolute dry weight before alkali weight reduction (g) N ↓ 2: absolute dry weight after alkali weight reduction (g) Measurement of absolute dry weight: sample under reduced pressure of 1 mmHg, temperature 5
The weight (g) after vacuum drying at 0 ° C. for 8 hours was measured. (3) Hollow ratio (%) The cloth after the alkali treatment is cut and the cut surface is SEM.
A photograph was taken, and the above-mentioned T, A, and B in each fiber cross section were calculated from the photograph, and the hollow ratio (%) = 100− {B / (T−A)} × 100 from the hollow ratio of each fiber. Was calculated, and the average value of a plurality of fibers on the cut surface was calculated. (4) Ultraviolet shielding property It was determined by measuring the ultraviolet transmittance of the sample using an ultraviolet intensity integrator manufactured by Toray Techno Co., Ltd. That is, the sample was placed on the center of the ultraviolet intensity integrating meter, and the amount of each ultraviolet ray was measured without placing the sample on the center of another integrating meter, and the value was calculated by the following formula. UV transmittance (%) = 100 x (U / U ↓ 0) U: UV amount on the sample mounting side U ↓ 0: UV amount on the side where no sample is mounted (5) Water absorption rate (%) Dry the fabric After soaking the sample obtained in water for 30 minutes or more, a household electric washing machine (PF-250 manufactured by Hitachi, Ltd.)
Dehydration was carried out for 5 minutes with the dehydrator of 0), and it was determined by the following formula. Water absorption rate (%) = {(WD) / D} × 100 W: weight of sample after dehydration for 5 minutes (g) D: weight of dry sample (g) (6) heat retention rate (%) ASTM D- It is a value (%) measured by a heat retention tester prepared according to 1518-57T.

Example 1 79.5 parts by weight of polyethylene terephthalate ([PET]) having [η] = 0.65 and titanium dioxide having an average particle size of 0.4 μm (Titanium Industry Co., Ltd.) (Production: UV transmittance is almost zero) 20 parts by weight and 0.5 part by weight of magnesium stearate were added, and the mixture was extruded at a temperature of 290 ° C. with a twin-screw kneader, and the extruded strand was cut to obtain pellets. Obtained PET containing titanium dioxide
The composite ratio of nylon and nylon 6 is 1: 1 so that the titanium dioxide-containing PET is the core layer and the nylon 6 is the sheath sea layer.
Composite spinning was performed as shown in FIG. 1 at a spinning temperature of 290 ° C. and a spinning speed of 1000 m / min, and the obtained undrawn yarn was drawn by contacting it with a hot roller at 75 ° C. and a hot plate at 150 ° C. As a result, a spun drawn composite yarn of 75 denier / 24 filament was obtained.

Taffeta was woven using the obtained composite yarn as warp and weft. The raw density is 117 warps /
The size was 106 wefts / size. The taffeta was boiled for 30 minutes in an aqueous solution containing sodium carbonate at a rate of 2 g / liter to desizing, and then preset at 160 ° C. for about 40 seconds. Next, alkali treatment was carried out by immersing in an alkaline aqueous solution containing 40 g / liter of sodium hydroxide and 2 g / liter of benzyldimethyldodecyl ammonium chloride at a bath ratio of 50: 1 at a temperature of 95 ° C. for the time shown in Table 1. It was After that, it was immersed in an aqueous solution containing acetic acid at a rate of 2 cc / liter for neutralization, and then washed sufficiently with water to obtain taffeta having the weight loss rate and hollow rate shown in Table 1.

The UV shielding property, water absorption rate and heat retention rate of the obtained taffeta were measured, and the results are shown in Table 2.

Examples 2 to 3 In Example 1, the amount of titanium dioxide added was 13.3% by weight (Example 2) and 10.3% by weight (Example 3).
Taffeta having the weight loss ratio and the hollow ratio shown in Table 1 was obtained in the same manner except that the alkali treatment was performed for the time shown in Table 1.
The ultraviolet shielding property, water absorption rate and heat retention rate of the obtained taffeta were measured, and the results are shown in Table 2.

Example 4 In Example 1, the amount of titanium dioxide added, nylon 6
The taffeta having the weight loss rate and the hollow rate shown in Table 1 was obtained in the same manner except that the composite ratio was changed to that shown in Table 1 and the alkali treatment was performed for the time shown in Table 1. The ultraviolet shielding property, water absorption rate and heat retention rate of the obtained taffeta were measured, and the results are shown in Table 2.

Comparative Example 1 A taffeta was obtained in the same manner as in Example 1, except that the alkali treatment was not performed, that is, the hollow portion was not formed. The ultraviolet shielding property, water absorption rate and heat retention rate of the obtained taffeta were measured, and the results are shown in Table 2. Since it does not have a hollow part,
It was inferior in water absorbency and heat retention and had no feeling of swelling.

Comparative Examples 2-3 In Example 1, the hollow rate was 2% (Comparative Example 2), 100
% (Comparative Example 3) except that the alkali treatment was performed to obtain taffeta. The ultraviolet shielding property, water absorption rate and heat retention rate of the obtained taffeta were measured, and the results are shown in Table 2. Taffeta having a hollow ratio of only 2% was inferior in water absorbency and heat retention and had no bulging feeling. The hollow ratio is 10
Hollow fibers consisting of 0%, that is, nylon 6 alone did not have elasticity, which is a characteristic of polyester fibers, and had no bulging feeling at all.

Comparative Example 4 A taffeta was obtained in the same manner as in Example 2, except that the alkali treatment was not performed, that is, the hollow portion was not formed. The ultraviolet shielding property, water absorption rate and heat retention rate of the obtained taffeta were measured, and the results are shown in Table 2. Since it does not have a hollow part,
It was inferior in water absorbency and heat retention and had no feeling of swelling.

Comparative Examples 5 to 6 Spinning was performed in the same manner as in Example 1 except that the composite ratio of PET and nylon 6 to which no inorganic fine particles were added was changed as shown in Table 1, but the spinning processability was poor and taffeta was obtained. I couldn't do that.

[0048]

INDUSTRIAL APPLICABILITY The hollow composite fiber of the present invention is excellent in water absorbency and heat retention, and is lightweight and flexible even though it contains inorganic fine particles, and has a good feeling of swelling. There is. In addition, the PES-based polymer remaining in the hollow composite fiber also has sag resistance due to its high elastic modulus. According to the production method of the present invention, it is possible to easily and smoothly produce a composite fiber having a small fiber fineness and a high hollow ratio in the fiber cross section without causing troubles such as a fiberizing step and an alkali treating step, coloring, and the like. . Further, in the production method of the present invention, alkali treatment can be promoted by allowing a quaternary ammonium salt to coexist in an aqueous alkali solution.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a fiber cross section of a multi-core core-sheath type composite fiber used for producing the hollow composite fiber of the present invention.

FIG. 2 is a view showing a fiber cross section of a hollow conjugate fiber of the present invention formed from the multi-core sheath-type conjugate fiber of FIG.

[Explanation of symbols]

 1 core component 2 sheath component 3 hollow part 4 reduced core component

[Table 1]

[Table 2]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location D01D 5/30 Z 7199-3B 5/34 7199-3B D01F 1/10 7199-3B 6/92 301 M 7199-3B D06M 11/38

Claims (2)

[Claims] 1. A cross-sectional shape in which a polyester polymer part containing inorganic fine particles is completely surrounded by a fiber-forming polymer part which has a slower alkali decomposition rate than the polyester polymer part or does not decompose into alkali. A multi-core sheath-sheath composite fiber having a hollow part between the polyester polymer part and the fiber-forming polymer part and having two or more cores, having the following formula (I) and formula: Hollow composite fiber characterized by satisfying (II). 0.3 × T ≦ B ≦ 0.9 × T (I) 20 ≦ 100- {B / (TA)} × 100 <100 (II) In the above formulas (I) and (II), T: Cross-sectional area of composite fiber including hollow part A: Fiber-forming polymer occupying cross-sectional area of composite fiber
Area B: Area of the polyester polymer part in the cross-sectional area of the composite fiber 2. A multicore core-sheath composite fiber having a fiber-forming polymer as a sheath component and a polyester polymer as a core component is alkali-reduced to remove a part of the polyester polymer in the composite fiber. The method for producing a hollow composite fiber according to claim 1, wherein.