JPH11269724A - Sheath-core type conjugate fiber and blended yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheath-core type conjugate having high hygroscopicity and high water absorbability and useful for woven fabrics or knitted fabrics having good wearing amenity. SOLUTION: This sheath-core type conjugate fiber comprises a core component and a sheath component in a core component/sheath component weight ratio of 5/95 to 50/50. A thermoplastic resin forming the core component comprises a copolyester copolymerized with a polyoxyalkylene glycol, containing 0.1-20 mol.% of a cross-linking agent of the general formula: (R2 O)mR1 (COOR3 )n [R1 is a trivalent to hexavalent organic residue; R2 is hydrogen or acetyl group; R3 is hydrogen or an alkyl group; 3<=(m)+(n)<=6], and exhibiting a moisture- absorbing or releasing parameter (ΔMR) of >=10.0%. A thermoplastic resin forming the sheath component is a fiber-forming polyamide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core-sheath composite fiber. More specifically, the present invention relates to a synthetic fiber for clothing having excellent comfort, and a core-sheath type composite having excellent hygroscopicity which can be particularly suitably used for clothing materials such as innerwear, inner garments, and sports clothing. It is about fibers.

[0002]

2. Description of the Related Art Polyamide fibers such as nylon 6 and nylon 66 have excellent mechanical strength, chemical resistance, heat resistance, and ease of resin processing, and are widely used mainly in clothing and industrial applications. Have been. However, polyamide fibers have low hygroscopicity, so if they are used in the field where they are directly in contact with the skin or worn close to the skin, such as inners and inner garments, the swelling due to perspiration from the skin will occur. , Causing stickiness and the like, and is inferior to natural fibers in terms of comfort. For this reason, as described in JP-B-60-475, JP-B-60-40612, or JP-A-60-215835, various types of fibers having a high equilibrium moisture content (moisture absorption) are used. Mixed fiber, mixed twist,
Attempts have been made to obtain moisture-absorbing comfort as a fabric by aligning the fabric. Although the use of these methods certainly improves comfort, the effect is not sufficient.On the other hand, disperse dyes, which are generally used when dyeing polyamide fibers, cause stains, And the inherent physical properties of polyamide fibers are lost.

As a method for imparting moisture absorption properties to polyamide fibers, acrylic acid, methacrylic acid or the like is graft-polymerized as disclosed in JP-A-56-24426 to form a carboxyl group substituted with an alkali metal inside the fiber. It is known to introduce the compound or to graft-polymerize a large amount of an amide compound such as acrylamide. If the amount of the carboxyl group substituted by the alkali metal is increased, the moisture absorption property is increased, and the moisture absorption property more than that of cotton can be obtained. However, fabrics that have been given hygroscopicity by a post-processing method such as this method are liable to cause stain spots due to the presence of a large amount of moisture-absorbing components on the fiber surface, and the amount of carboxyl groups substituted with alkali metals is less. As the number increases,
However, it has not been put to practical use because it has a drawback that a slimy feeling becomes strong when wet with water.

[0004] Japanese Patent Publication No. 55-4852, Japanese Patent Application Laid-Open No. Hei 7-150414, and Japanese Patent Application Laid-Open No. Hei 7-150415 propose hygroscopic polyamide fibers containing polyvinylpyrrolidone as a hygroscopic component. However, in this method, when a large amount of polyvinylpyrrolidone is added in order to increase the hygroscopicity of the polyamide fiber, there is a problem that polyvinylpyrrolidone is gradually precipitated from the fiber and becomes sticky during wearing. Could not be given.

[0005] As described above, the method of imparting hygroscopicity in the post-processing stage and the method of mixing the hygroscopic component in the spinning stage have various problems in dyeing or in the properties of the obtained fabric. In order to solve such problems, a core-sheath composite in which a blend resin of a polyethylene oxide crosslinked product having a high moisture absorption rate and a saponified ethylene / vinyl acetate copolymer is used as a core, and the resin is covered with a sheath polyamide. The fiber is disclosed in
No. 28 is proposed. Since the core-sheath type conjugate fiber covers the highly hygroscopic component with the sheath component, it has a relatively smooth touch and good texture while having hygroscopicity. However, since the moisture-absorbing component used in the core-sheath composite fiber is expensive, it increases the production cost of the fiber, and the use of the core component lowers the mechanical strength. Could not be expanded.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the above-mentioned problems of the prior art, and to provide a core sheath which is free from process troubles, has good high-order workability, has high moisture absorption and is excellent in wearing comfort. It is intended to provide a type composite fiber.

[0007]

Means for Solving the Problems To solve the above-mentioned problems, the core-sheath type conjugate fiber of the present invention mainly has the following constitution. That is, the copolymerized polyester forming the core contains polyoxyalkylene glycol as a copolymerization component, and the following general formula (I) (R ₂ O) mR ₁ (COOR ₃ ) n (I) (wherein R ₁ is Trivalent to hexavalent organic residue, R ₂ is hydrogen or acetyl group, R ₃ is hydrogen or alkyl group, 3 ≦ m +
a core-sheath containing 0.1 to 20 mol% of a crosslinking agent represented by n ≦ 6), exhibiting a moisture absorption / desorption parameter (ΔMR) of 10.0% or more, and having a sheath portion formed of a fiber-forming polyamide. Type composite fiber, wherein the weight ratio of core / sheath is 5/95.
鞘 50/50.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The copolyester forming the core of the core-sheath type conjugate fiber of the present invention is a component that imparts hygroscopicity to the fiber, and has higher hygroscopicity than the fiber-forming polyamide in the sheath. It is essential. Examples of the acid component of the copolymerized polyester include terephthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, aromatic dicarboxylic acids such as 4,4′-dicarboxydiphenyl, and 5-sodium sulfoisophthalic acid, adipic acid, And aliphatic dicarboxylic acids such as sebacic acid. Particularly preferred is terephthalic acid. Examples of the glycol component include ethylene glycol, propylene glycol, tetramethylene glycol, diethylene glycol, neopentyl glycol and the like. Particularly preferred is ethylene glycol.

In order to impart hygroscopicity to the copolymerized polyester, it is necessary to copolymerize a polyoxyalkylene glycol. Examples of the polyoxyalkylene glycol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, methoxy polyethylene glycol, a block copolymer of polyethylene glycol and polypropylene glycol, a random copolymer of ethylene oxide and propylene oxide, and derivatives thereof. . Particularly preferred is polyethylene glycol.

[0010] The moisture absorption / desorption parameter (hereinafter referred to as ΔMR) indicating the moisture absorption properties of the copolymerized polyester forming the core of the core-sheath type conjugate fiber of the present invention is 10% or more, and 15% or more. Further, it is preferably at least 20%.

Here, ΔMR is a value obtained by subtracting the moisture absorption rate (MR ₁ ) at 20 ° C. × 65% RH from the moisture absorption rate (MR ₂ ) at 30 ° C. × 90% RH (ΔMR (%) = MR ₂ -M
R ₁ ). ΔMR is a driving force for obtaining comfort by releasing moisture in clothes to the outside air when the clothes are worn, and is represented by 30 ° C. × 90% RH when light to medium work or light to medium exercise is performed. Temperature of clothing and 20 ℃
X The difference in moisture absorption rate from the outside temperature and humidity represented by 65% RH. In the present invention, this ΔMR is used as a parameter as a scale for evaluating hygroscopicity. The larger the ΔMR, the higher the moisture absorption / desorption ability and the better the comfort when worn. If the ΔMR is less than 10%, the comfort at the time of wearing intended in the present invention cannot be obtained.

The amount of the polyoxyalkylene glycol copolymerized in the copolymerized polyester is from 40 to 99% by weight, and more preferably from 50 to 99% by weight, in terms of hygroscopicity, spinnability and mechanical properties of the fiber.
~ 90% by weight is preferred.

The number average molecular weight of the polyoxyalkylene glycol in the copolymerized polyester is from 2,000 to 20,000, more preferably from 4,000 to 150, from the viewpoints of compatibility with the polyester, dispersibility and easy chipping.
00 is preferable.

As a crosslinking agent contained in the copolymerized polyester, the following general formula (I) (R ₂ O) mR ₁ (COOR ₃ ) n (I) (reacted with the polyester to form a crosslinked structure) Wherein R ₁ is a trivalent to hexavalent organic residue, R ₂ is hydrogen or an acetyl group, R ₃ is a hydrogen or alkyl group, and 3 ≦ m +
It is necessary to use a polyfunctional compound represented by n ≦ 6). Here, “containing” includes dispersing in a polyester, but preferably has a crosslinked structure by copolymerization. The compound is preferably a polyfunctional carboxylic acid such as trimellitic acid or pyromellitic acid, or a polyol such as glycerin, trimethylolpropane, or pentaeristol, but trimellitic acid is particularly preferable in terms of heat resistance. The inclusion of the crosslinking agent enhances the hygroscopicity of the polymer, and further facilitates chipping since a crosslinked structure is formed in the polymer. In addition, it also has the effect that the physical properties hardly change with time when the fibers are formed.

The proportion of the crosslinking agent in the copolymerized polyester is 0.1 to 2 with respect to the acid component constituting the copolymerized polyester.
0 mol%, and preferably 0.5 to 10 mol%. If the content is less than 0.1 mol%, it becomes difficult to make the polymer into chips, stable discharge at the nozzle discharge hole cannot be expected, and the spinning property becomes unstable, and further, the mechanical strength of the fiber decreases. On the other hand, if it exceeds 20 mol%, a rapid crosslinking reaction occurs during the polymerization, and a desired copolymerized polyester cannot be obtained.

The fiber-forming polyamide forming the sheath portion of the core-sheath type composite fiber of the present invention includes nylon 6, nylon 66, nylon 46, nylon 9, nylon 610, nylon 11, nylon 12, nylon 612, and the like, or Examples thereof include compounds having an amide-forming functional group and a copolymer polyamide containing a copolymer component such as laurolactam, sebacic acid, terephthalic acid, isophthalic acid, and 5-sodium sulfoisophthalic acid. Of these, nylon 6 or nylon 66, which has high toughness, abrasion resistance and transparency, and can be used for stockings, is particularly preferred.

Although a small amount of the moisture-absorbing component of the present invention described below may be mixed in the fiber-forming polyamide, it is preferable to suppress the mixing amount to 10% by weight or less in order to obtain good yarn-forming properties. .

The copolyester is a moisture-absorbing component used in the present invention, and is disposed at the core of the core-sheath type conjugate fiber. The weight ratio of the core, which is a moisture absorbing component, to the sheath, which is a fiber-forming polyamide, needs to be 5/95 to 50/50. It is preferably from 10/90 to 40/60, and more preferably from 15/85 to 30/70. Weight ratio is 5 /
If it is less than 95, sufficient hygroscopicity cannot be obtained. 5
If it is more than 0/50, cracks on the fiber surface due to swelling are likely to occur in a hot water atmosphere such as dyeing, etc., resulting in lower high-order workability.

In addition, the copolymerized polyester forming the core and the fiber-forming polyamide forming the sheath of the present invention include pigments such as titanium oxide and carbon black, alkylbenzene sulfonic acid as long as the object of the present invention is not impaired. Surfactants such as salts, conventionally known antioxidants, anti-coloring agents,
Of course, a light stabilizer, an antistatic agent, etc. may be added.

The core-sheath type conjugate fiber of the present invention is obtained by disposing a fiber-forming polyamide in a sheath portion and a copolymer polyester as a moisture absorbing component in a core portion. Since the fiber-forming polyamide disposed in the sheath is relatively hydrophobic, it has low hygroscopicity. Therefore, even in a high humidity environment, the fiber surface is always smooth, and there is little discomfort due to stickiness.
Good wearing comfort. Further, since the core-sheath type conjugate fiber of the present invention can be dyed at a normal pressure of 100 ° C. or less, swelling during hot water treatment can be suppressed without impairing hygroscopicity, and high-order workability such as dyeing is improved.

The core-sheath type conjugate fiber of the present invention can be obtained by the following method. For example, a polyamide (sheath portion) and a copolyester (core portion) are separately melted, guided to a spinning pack, formed into a core-sheath composite flow in a spinneret, and spun from a discharge hole.

After the spun filament yarn is taken out at a predetermined speed, it is once wound up in a package, and the obtained undrawn yarn is drawn by an ordinary drawing machine. Further, after taking out the spun yarn, it may be continuously stretched as it is and wound up (direct spinning drawing method), or it may be taken out at a high speed of 4000 m / min or more to obtain desired fiber performance at once. Good.

As a direct spin drawing method, for example, a spun yarn is taken at 1,000 to 5,000 m / min, and subsequently, 3,000 to 7000 m / m
Per minute and heat setting.

The cross-sectional shape of the core-sheath type conjugate fiber of the present invention is preferably a multi-lobal cross-section having 3 to 8 concave portions and the same number of convex portions as shown in FIG.
By having irregularities in the fiber cross section and being formed continuously in the longitudinal direction of the fiber, a large number of capillary voids are formed when a multifilament is used, and high water absorption performance is provided. Among the multi-lobal sections, a pentalobal section (five leaves) or a hexalobal section (six leaves) is more preferable. In addition, from the viewpoint of improving water absorption performance and preventing a decrease in spinnability and a decrease in fiber properties such as strength, the degree of irregularity is preferably in the range of 1.3 to 5.0. More preferably, the degree of irregularity is 1.8 to
It is in the range of 4.0.

Here, the degree of irregularity is, as shown in FIG. 2, a radius ratio R1 / R of a circumscribed circle R1 of an irregular cross section and an inscribed circle R2.
Say 2.

In order to further increase the water absorption, a fiber having a fiber cross-section with a degree of irregularity of 1.3 or less and having substantially no irregularities and a multi-lobal cross-section with a fiber cross-section with a degree of irregularity of 1.3 to 5.0 are used. It is preferable that fibers are dispersed and mixed in a random state, and one or both of the fibers are mixed fibers that are the core-sheath type composite fibers of the present invention. For example, when a core-sheath composite fiber having a round cross section (irregularity 1.0) and a core-sheath composite fiber having a deformity 1.3 or more are mixed, the multi-lobal cross section and the round cross section are adjacent to each other, so Thus, a capillary space is efficiently formed, and water absorption is improved. In addition, a mixing ratio (% by weight) when two types having different irregularities are mixed.
Is equal to or greater than 1.3 / less than or equal to 1.3 = 80/20
-30/70 is preferable, and 70 / 30-40 / 6.
A range of 0 is more preferred.

The core-sheath composite form may be any form as long as the moisture-absorbing component forming the core is not exposed on the fiber surface, and examples thereof include concentric circles, eccentric circles, and islands. Further, the core-sheath type composite fiber of the present invention preferably has a hollow portion inside the fiber. The presence of the hollow portion allows the hollow portion to absorb the swelling of the moisture-absorbing component due to absorption and release of moisture, so that a high moisture absorption / desorption parameter ΔMR can be obtained without applying pressure to the sheath portion.

The core-sheath type composite fiber of the present invention may be in the form of a filament or staple, and may be subjected to false twisting. Fabric forms include woven, knitted,
It can be appropriately selected according to the purpose such as a nonwoven fabric.

[0029]

The present invention will be described in more detail with reference to the following examples.

Each characteristic value in the examples was obtained by the following method. A. Moisture absorption / desorption parameter of copolymer polyester polymer and conjugate fiber ΔMR The moisture absorption rate is as follows. In the case of polymer, the chip is cut into a cube of about 2 mm square. Dry weight is about 1g, 20 ℃ × 6
The weight was determined by the following equation from the change in weight with the weight after standing for 24 hours in a thermo-hygrostat (PR-2G manufactured by Tabai) in an atmosphere of 5% RH or 30 ° C. × 90% RH.

Moisture absorption rate (%) = {(weight after moisture absorption−weight at absolute dryness) / weight at absolute dryness} × 100 20 ° C. × 65% RH and 30 ° C. × 90% measured above.
From the moisture absorption rate under the condition of RH (referred to as MR ₁ and MR ₂ respectively), the moisture absorption / desorption parameter ΔMR (%) = MR ₂ −M
Determine the R _1. Here, the moisture absorption / desorption parameter ΔMR is a driving force for obtaining comfort by releasing moisture in the clothes when the clothes are worn to the outside air, and is 30 ° C. when light to medium work or light to medium exercise is performed. The difference in moisture absorption between the temperature inside the clothes represented by × 90% RH and the outside temperature and humidity represented by 20 ° C. × 65% RH. In the present invention, this ΔMR is used as a parameter for evaluating the hygroscopicity, and the larger the ΔMR, the higher the hygroscopicity and the better the comfort when worn. For practical use, ΔMR of 3% or more is preferable for obtaining comfortable wearing.

B. Chip shape at the time of water-cooled discharge of copolymerized polyester (abnormal chip) A chip having a chip length of 30 mm or more was regarded as an abnormal chip, and was expressed as a percentage by weight based on the total chip amount.

C. Yarn-producing property The case where the number of times of thread breakage when the multifilament was produced at 2 × 10 ⁷ m was less than one time was ○, the case where it was 1 or more and less than 2 times was Δ, and the case where 2 or more times was ×.

D. Water Absorption Characteristics of Fibers The measurement of water absorption (water absorption height) was determined in accordance with the JIS standard's birec method. However, the measurement time was 5 minutes. The diffusivity (quick drying property) was determined according to the drop method according to JIS standards. For each characteristic, the case where the level was equal to or higher than the cotton level was regarded as acceptable. Cotton has a water absorption height of 82 mm and a diffusivity of 9.
5 cm ² .

E. Presence or absence of core component outflow after passing through the high-order process The sample after dyeing / reduction washing is disassembled, one composite yarn (multifilament) is taken out, the cross section of the fiber is sampled in a flake shape, and a single fiber is observed with a microscope. Observing each fiber for cracks in the fiber, cracks occur from the core to the surface of the fiber, and when there is no single yarn out of five multifilaments from which the core component flows out, When one or two single yarns were generated and outflow of the core component was observed, Δ was determined when three or more single yarns were detected.

F. Wearing comfort A tricot knitted fabric was knitted from the sample yarn, and an inner was sewn from the knitted fabric. Five subjects wear this inner, and after resting for 1 hour in an artificial weather room under the temperature and humidity conditions of 20 ° C. × 65% RH, place on a 20 cm high block.
After performing a 0-minute stepping-up / down exercise, and then maintaining a resting state for 20 minutes, a questionnaire regarding the feeling of wearing was taken.
The number of respondents who answered that they were comfortable without stuffiness and stickiness was 5 or more, ◎ when 4 or more, ○ when 3 or less, × when 2 or less.

Example 1 As a copolymerized polyester,
194 parts of dimethyl terephthalic acid, ethylene glycol 1
28 parts, trimethyl trimellitate (hereinafter TMTM)
(M = 0, n = 3, R1 = aromatic, R3 = methyl group)
7.8 parts and 0.2 parts of tetrabutyl titanate were added, and the ester exchange reaction was performed while distilling methanol at 140 to 230 ° C., followed by an ethylene glycol solution of trimethyl phosphate 0.08 parts and a number average molecular weight of 8,000. 288 parts of polyethylene glycol, Irga as antioxidant
1 part of nox 1010 (manufactured by Ciba Geigy), 1 part of silicon as an antifoaming agent, and 0.3 part of tetrabutyl titanate were added, and polymerization was carried out under a reduced pressure of 1.0 mmHg at 250 ° C. for 4 hours. After the completion of the polymerization, the molten polymer was discharged in a gut shape at a rate of 3 kg / min from the discharge portion of the polymerization can. This gut-like polymer is put into cooling water (water temperature 18 ° C.), and the polymer after cooling is about 5 mm × 3 mmφ with a normal cutter.
Chip. The cutting properties at the time of chipping were good, and the abnormal chips were 1.0%. The proportion of TMTM copolymerized with this copolymer was 2.0 mol%, and the proportion of polyethylene glycol was 60% by weight. The ΔMR of the obtained copolyester was 24.5% (MR
1 = 1.6%, MR2 = 26.1%).

The above copolymerized polyester is used as a core component,
Nylon 6 having a relative viscosity ηr of 2.55 in sulfuric acid is used as a sheath component, and a weight ratio of a core / sheath portion is determined from a core / sheath type composite die having a radial 5-slit discharge hole at a spinning temperature of 260 ° C.
It was discharged at 20/80 and wound up by a direct spinning and drawing method at a spinning speed of 3000 m / min and a drawing speed of 5000 m / min to obtain a core-sheath type composite yarn having 50 decitex and 18 filaments. The cross-sectional shape of the composite fiber was pentalobal (five leaves), and the degree of irregularity was about 1.8. Further, the ΔMR of the conjugate fiber was 5.4% and had a good moisture absorption property. Further, the water absorption (water absorption height) was 113 mm, and the diffusivity by the dropping method was 18.3 cm ^2, and all the water absorption properties were high levels. The composite yarn was knitted to form a tricot knitted fabric, and the knitted fabric was sewn to form an inner.
This inner is made with a commercially available acid dye at about 95 ° C. according to a standard method.
× 60 minutes immersion, water washing for about 10 minutes, further about 8 minutes
The color was fixed at 0 ° C. for 10 minutes, dyed in an appropriate color, and washed again for about 10 minutes. The appearance quality of the finished product was good, and even in the evaluation of wearing by five subjects, no one felt stuffiness or stickiness, and showed extremely good wearing comfort. The results are shown in Table 1.

[0039]

[Table 1] (Examples 2 and 3, Comparative Examples 1 and 2) The amounts of copolymerized TMTM were 0.3 mol% (Example 2), 15 mol% (Example 3) and 0.05 mol% (Comparative Example 1). A copolymerized polyester was obtained in the same manner as in Example 1 except that the amount was 21 mol% (Comparative Example 2). In the case of Example 2, the chip formation at the time of ejection was stable, and the abnormal chip ratio was as good as 2.5%. Example 1 using the obtained copolyester as a core
As a result of spinning and evaluation in the same manner as in
Was 5.3%, and the wearing comfort of the obtained knitted fabric was extremely good as in Example 1. In the case of Example 3, yarn breakage occurred during spinning, and the yarn formability was slightly poor. However, the ΔMR of the obtained composite fiber was as high as in Example 1, and the wearing comfort of the knitted fabric was good. Met. Also, TMTM
In Comparative Example 1 having a copolymerization amount of 0.05 mol%, it was difficult to form chips at the time of ejection, and the abnormal chip rate was as poor as 12%. On the other hand, when the TMTM copolymerization amount exceeded 20 mol% (Comparative Example 2), the crosslinking reaction proceeded rapidly, and a copolymerized polyester could not be obtained. The results are shown in Table 1.

(Example 4, Comparative Example 3) The copolymerization amount of polyethylene glycol was 45% by weight (Example 4) and 35%.
A copolymerized polyester was obtained in the same manner as in Example 1 except that the amount was changed to% by weight (Comparative Example 2). The ΔMR of the copolyester of Example 4 was 12.8%. The copolyester was used as a core part to produce a yarn in the same manner as in Example 1, and as a result, ΔMR of the conjugate fiber was 3.5%. The wearing comfort of the obtained knitted fabric was higher than that of Example 1. Inferior, but relatively good. In Comparative Example 3 in which the copolymerization amount of polyethylene glycol was 35% by weight, the ΔMR of the copolymerized polyester was as low as 7.5%, and the wearing comfort of the obtained knitted fabric was poor. The results are shown in Table 1.

Example 5, Comparative Examples 4 and 5 The molecular weight of polyethylene glycol was 3000 (Example 5) and 15
Copolymerized polyesters were obtained in the same manner as in Example 1 except that 00 (Comparative Example 4) and 24000 (Comparative Example 5) were used. The ΔMR of the copolyester of Example 5 was 26.6.
% Good moisture absorption / release properties. The copolyester was used as the core to form a yarn and evaluated in the same manner as in Example 1. As a result, the ΔMR of the composite fiber was 5.7%, and the wearing comfort of the obtained knitted fabric was the same as in Example 1. Was very good. Further, the molecular weight of polyethylene glycol is set to 1500
In Comparative Example 4, where it was difficult to form chips at the time of ejection, the abnormal chip rate was as poor as 12.6%. In Comparative Example 5 in which the molecular weight of polyethylene glycol was 25,000, ΔMR of the copolymerized polyester was as low as 9.5%, and the knitted fabric obtained by using the copolymerized polyester as the core in the same manner as in Example 1 was comfortable to wear. The properties were poor. The results are shown in Table 1.

(Examples 6-9, Comparative Examples 6-7) Tricots were knitted in the same manner as in Example 1 except that the core-sheath composite ratio of the copolymerized polyester at the core and the polyamide at the sheath was changed. Each characteristic of this knitted fabric was evaluated. The results are shown in Table 1. Examples 6 to 9 had good moisture absorption / desorption properties and water absorption properties, and also had good wearing comfort. On the other hand, in Comparative Example 6, since the ratio of the core (copolyester) was small, the ΔMR was low and the wearing comfort was poor. ,
In Comparative Example 7, although the ΔMR was as high as 9.1% due to a large amount of the copolyester in the core portion, many cracks occurred on the fiber surface during the hot water treatment, and the copolyester flowed out to the fiber surface. Stickiness occurred and wearing comfort was inferior.

(Example 10) As a result of spinning and evaluation in the same manner as in Example 1 except that nylon 66 having a relative viscosity ηr in sulfuric acid of 2.55 was used as a sheath component and the spinning temperature was set to 290 ° C, The ΔMR of the conjugate fiber was 5.1%, and the wearing comfort of the obtained knitted fabric was extremely good as in Example 1. The results are shown in Table 1.

Example 11 The composite yarn obtained in Example 1 was subjected to high-temperature steam treatment at 120 ° C. for 1 minute, and as a result, a hollow portion was formed in the core of the composite fiber. The hollow ratio of this hollow portion was 4%, and the ΔMR of the composite yarn was 6.2%.
The wearing comfort of the obtained knitted fabric was even better than that of Example 1. The results are shown in Table 1.

Example 12 A tricot was knitted in the same manner as in Example 1 except that the specifications of the discharge holes were changed and the degree of irregularity of the fiber cross section was changed. The irregularity of the conjugate fiber was 3.8, and the water absorption property was superior to that of Example 1.
The results are shown in Table 1.

(Embodiment 13) Radial 6 as shown in FIG.
A tricot was knitted in the same manner as in Example 1 except that a core-sheath type composite die in which slit discharge holes (11 holes) and round holes (7 holes) were dispersed was used. The obtained mixed fiber had the cross-sectional shape shown in FIG. 4, and had good moisture absorption / release properties. Further, the water absorption property was superior to that of Example 1. The results are shown in Table 1.

[0047]

The core-sheath type composite fiber obtained by the present invention has a very high moisture absorbing property, and a woven or knitted fabric using the same has sufficient moisture absorbing and releasing properties to obtain wearing comfort. It has a dry touch texture and high color fastness and light fastness. Further, even under a severe atmosphere such as a dyeing condition, the surface of the fiber is not cracked or cracked, so that it can be applied to a wide range of applications. The core-sheath type composite fiber of the present invention is suitable for underwear, shirts / blouses, middle garments, sportswear, slacks, and lining, and is extremely practical.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example of a fiber preferably used in the present invention.

FIG. 2 is a cross-sectional view of a fiber for explaining the degree of irregularity of the fiber.

FIG. 3 is a schematic plan view showing an example of a discharge hole arrangement of a die preferably used in the present invention.

FIG. 4 is a cross-sectional view of a fiber showing an example of a mixed fiber composite yarn preferably used in the present invention.

[Explanation of symbols]

 1 Tri-lobal section 2 Tetra-lobal section 3 Penta-lobal section 4 Hexa-lobal section 5 Hepta-lobal section 6 Octa-lobal section

Claims (7)

[Claims] The copolymerized polyester forming the core contains a polyoxyalkylene glycol as a copolymerization component, and is represented by the following general formula (I) (R ₂ O) mR ₁ (COOR ₃ ) n (I) R ₁ is a trivalent to hexavalent organic residue, R ₂ is hydrogen or an acetyl group, R ₃ is a hydrogen or alkyl group, 3 ≦ m +
a core-sheath containing 0.1 to 20 mol% of a crosslinking agent represented by n ≦ 6), exhibiting a moisture absorption / desorption parameter (ΔMR) of 10.0% or more, and having a sheath portion formed of a fiber-forming polyamide. Type composite fiber, wherein the weight ratio of core / sheath is 5/95.
Core / sheath type composite fiber, characterized in that the ratio is 50 to 50/50. 2. The core-sheath conjugate fiber according to claim 1, wherein the copolymerized polyester forming the core has a polyoxyalkylene glycol copolymerization amount of 40 to 99% by weight. 3. The core-sheath conjugate fiber according to claim 1, wherein the polyoxyalkylene glycol to be copolymerized has a number average molecular weight of 2,000 to 20,000. 4. The core-sheath type composite fiber according to claim 1, wherein a main component of the fiber-forming polyamide of the sheath portion is nylon 6 or nylon 66. 5. The core-sheath type composite fiber according to claim 1, wherein a hollow portion is formed in a cross section of the composite fiber. 6. A multi-lobal cross section having a fiber cross section having 3 to 8 concave portions and the same number of convex portions, and having a degree of irregularity of 1.3 to 5.0. 6. The core-in-sheath type conjugate fiber according to any one of items 1 to 5. 7. A fiber having a fiber cross-section irregularity of 1.3 or less and a fiber having a fiber cross-section irregularity of 1.3 to 5.0 are dispersed and mixed in a random state, A mixed fiber, wherein one or both fibers are the core-sheath composite fibers according to any one of claims 1 to 6.