JPH0434017A - Sheath-core conjugate fiber - Google Patents

Abstract

PURPOSE:To obtain the subject fiber which is sheath-core conjugate fiber having a polyamide as a sheath part and a specific polyester as a core part, excellent in hygroscopicity, antifouling and deodorizing properties and useful as sportswear, etc., by using the polyamide containing a prescribed amount of carboxyl groups. CONSTITUTION:The objective fiber which is sheath-core conjugate fiber, having a sheath part containing preferably 20-75wt.% polyamide (e.g. nylon 6, obtained by copolymerizing sebacic acid, etc.) containing 7X10<-4> to 5X10<-3>equiv./g carboxyl groups and a core part of a sulfonated aromatic dicarboxylic acid- modified polyester (e.g. 5-sulfoisophthalic acid; the amount of copolymerization is preferably 0.5-6mol%). The content of a colorant in the sheath part is <=0.2% owf and the content of a colorant in the core part is <=10% based on that in the core part.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a core-sheath composite fiber.

More specifically, the present invention relates to a core-sheath composite fiber that has functions such as hygroscopicity, antistatic property, antifouling property, and deodorizing property, and is excellent in dyeing fastness such as needlepoint and washing properties.

[Prior Art] Polyamide fibers such as nylon 6 and nylon 66 are used in many clothing applications due to their excellent strength, abrasion resistance, deep dyeability, and ease of resin processing. ing. Furthermore, Japanese Patent Publication No. 60-34979 describes various methods of graft polymerizing hydrophilic vinyl monomers to polyamide fibers to impart hydrophilic functions such as hygroscopicity to further improve the comfort of wearing clothes. It is proposed as follows.

On the other hand, polyesters such as polyethylene terephthalate were generally dyed using disperse dyes; As a result, it has become possible to dye with cationic dyes, improving color development and making it possible to dye polyester fibers in different colors. However, the inherent drawbacks of polyester, such as insufficient abrasion resistance and resin processability, were not improved, and in fact tended to worsen.

Furthermore, many methods have been proposed that utilize the advantages of polyamide and polyester as composite fibers. In order to dye this composite fiber to obtain sufficient luminescence, it is necessary to dye both polyamide and polyester, for example, with a disperse dye, or a mixed dyeing recipe with an acid dye and a disperse dye or a cationic dye. It was necessary to use

However, with these dyeing formulations, the wet fastness or light fastness of the dyed products was unsatisfactory and were not practical.

Furthermore, in order to impart hydrophilicity including hygroscopicity to polyamide or polyester, there is a method of graft polymerizing a hydrophilic vinyl monomer. According to this, the presence of a dye in polyamide or polyester has problems such as discoloration and decolorization due to inhibition of graft polymerization and decomposition of the dye by a graft polymerization initiator. Therefore, it has been essential to perform these graft polymerizations before the dyeing process.

Furthermore, since unevenness in graft polymerization directly results in uneven dyeing, there is a problem in that process control conditions must be made more stringent than necessary.

Furthermore, the dyeing fastness of graft-polymerized polyamides or polyesters decreases, especially the wet fastness of dark colors such as navy blue. At present, they have been forced to limit their uses and have not been sufficiently developed as a product.

[Problems to be Solved by the Invention] In view of the above problems, the present invention provides a core-sheath composite fiber that has excellent color fastness and luminescence, and has functions such as hydrophilic properties such as hygroscopicity and deodorizing properties. The purpose is to provide.

[Means for Solving the Problems] In order to solve the above problems, the present invention has one of the following configurations. That is, it is a core-sheath composite fiber having a sheath made of polyamide and a core made of sulfonated aromatic dicarboxylic acid-modified polyester, and the polyamide has carboxyl groups of 7 x 10-4 to 5 x 10-4.
A core-sheath composite fiber characterized by containing 3 equivalents/g of polyamide, or a core-sheath composite fiber having a sheath of polyamide and a core of sulfonated aromatic dicarboxylic acid-modified polyester, wherein the polyamide contains 7 carboxyl groups
A core sheath containing x10-4 to 5X10-3 equivalent/g polyamide, characterized in that the colorant content in the sheath is 0.2% ovf or less and 10% or less of the colorant content in the core. It is a composite fiber.

The present invention will be explained in detail below.

One of the characteristics of the core-sheath composite fiber of the present invention is that the sheath component is polyamide, which is difficult to dye with cationic dyes, and the core component is sulfonated aromatic dicarboxylic acid-modified polyester (hereinafter referred to as modified polyester), which is easily dyed with cationic dyes. The core-sheath composite fiber is made to be a core-sheath composite fiber.

Another feature is that the polyamide of the sheath component contains a carbosyl group.

When coloring or dyeing the core-sheath composite fiber, one of the features is that most of the coloring agent such as a pigment or dye is introduced into the modified polyester side, which is the core component of the core-sheath composite fiber.

In this way, when substantially only the core of the core-sheath composite fiber is colored, due to the difference in refractive index from the polyamide sheath,
The colored fiber has excellent color development and clarity, and since there is virtually no colorant in the sheath, the color fastness, especially
Improves wet fastness against washing and wet rubbing.

The core-sheath composite ratio in the core-sheath composite fiber of the present invention is determined from the viewpoint of easily forming a uniform and durable sheath component and obtaining the desired luminescence without blocking the color of the colored modified polyester core. , the ratio of polyamide in the sheath is 20 to 7.
The content is preferably 5% by weight.

The arrangement of the polyamide sheath and modified polyester core is as follows:
Basically, it is preferable that the sheath be concentric, but it may be eccentric or multi-core as long as the sheath is too thin to break. Also,
If it is possible to cover the modified polyester core with a polyamide sheath, a modified cross-section yarn can also be used.

The method for producing the core-sheath composite fiber of the present invention includes:
First, polyamide and modified polyester are separately melted, introduced into a spinning pack section, formed into a composite flow so as to have a core-sheath structure in a conventional manner, and spun out from a nozzle.

The spun filament yarn is taken up at a predetermined speed, oiled, and then wound into a package. Next, the previously wound yarn is stretched using a draw twister in a conventional manner so as to obtain the desired strength and elongation.

This stretching may be carried out continuously without winding up the spun yarn after it is taken off. Alternatively, a method may be used in which the fibers are taken at a high speed of 4000 m/min or more to obtain the desired fiber performance.

A method for selectively coloring the core modified polyester can be achieved, for example, by spinning and reeling a modified polyester blended with a pigment as the core polymer as described above.

Pigments that can be applied to the core-sheath composite fiber of the present invention include Re
nol Yellow 5GG-AT, Reno
l Red 5G-AT.

Renol Blue AZR-AT (manufactured by Bayer Japan), PE5M-1031, PE5M-22
45, PE5M-2460 (manufactured by Inunichisei Chemical Industry Co., Ltd.), but the pigments are not limited to these, and both organic and inorganic pigments can be used. In addition to pigments, dyes may be used as the coloring agent as long as they can withstand the spinning temperature and allow stable spinning.

As another method of selectively coloring the modified polyester core, a method of dyeing with a cationic dye can also be applied. Examples of cationic dyes include Aixen
Cafbilon (manufactured by Hodogaya Chemical Industry), Kaya
cryl (manufactured by Nippon Kayaku), Estrol, Su
miacry (manufactured by Sumitomo Chemical), Diacryl
(manufactured by Mitsubishi Chemical Corporation), Maxi! on (manufactured by Ciba Geigy), ASlra! On (manufactured by Bayer Japan ■) and other named dyes may be used, but the dyes are not limited thereto, and dispersed cationic dyes may also be used.

As the staining conditions, ordinary cationic dye staining conditions can be applied. Also, soaping after dyeing should be done at 50°C to 80°C, including anionic surfactants, depending on the dye concentration used.
Preferably, the treatment is carried out in a hot water bath.

This soaping removes cationic dyes that have contaminated the polyamide sheath and cationic dyes that remain attached to the fiber surface.
This is done to easily incorporate carboxyl groups into the polyamide sheath.

In the core-sheath composite fiber of the present invention, luminescence, light fastness,
In order to obtain a dyed product with good washing fastness, the coloring agent content in the sheath is 0.2% owt or less and the coloring agent content in the core is 10% or less. It is more preferable that the colorant content in the sheath is 0.1% wt or less and 5% or less of the colorant content in the core.

When the colorant content of the sheath exceeds 0.2% owt, the washing fastness and light fastness are significantly reduced. Furthermore, if the colorant content in the sheath exceeds 10% of the colorant content in the core, it is difficult to obtain a sufficient level of light fastness.

For this purpose, soaping after dyeing may be performed in a hot water bath containing an anionic surfactant at a temperature of 50°C to 80°C.

The content of the coloring agent in the core may be set to an arbitrary level depending on the desired degree of coloring. In order to obtain luminescence that can be discerned with the naked eye, in the case of light-dyed products, a colorant content of 0.01% owt or more is generally sufficient. In addition, in the case of deeply dyed products, it is practically preferable to have an ovf of 50% ovf or less from a cost perspective.

The colorant content of the sheath or core as used in the present invention is a value expressed as a percentage of the weight of the colorant contained in the polymer of the sheath or core. 0.2% owt or less means that the polyamide 1 of the sheath
This means that the colorant content per g is 0.02 g or less.

In the present invention, the colorant content in the sheath or core is as follows:
It shall be obtained using the following method.

<Content of coloring agent in the sheath part> Weigh out a certain amount (200 cm) of dyed core-sheath composite fiber or its fabric, and immerse it in 30 ml of 88% formic acid solution at 30°C for 3 minutes. The polyamide and the dye dyed therein are dissolved, and a colorimeter "5pectra P" is used.
The absorbance at the maximum absorption wavelength is measured using a photometer U-3400 (manufactured by Hitachi ■).

In addition, weigh a certain amount (200cm) of the sample before staining, and
A predetermined amount (0.25 μm,
The absorbance is determined using a colorimeter, and the relationship between absorbance and dyeing rate for this dye is plotted as a calibration curve. With this calibration curve,
The coloring agent content (a%ovf) of the sheath is determined from the absorbance value of the polyamide sheath of the dyed sheath described above.

Coloring agent content in core section> First, the polyamide in the sheath section of the core-sheath composite fiber or its products is dissolved and removed, and then washed with water to obtain a dyed fiber component of the core-modified polyester. Weigh out a certain amount (100 cm) of the dyed fibers, put it in 30 ml of a mixed solution of phenol/tetrachloroethane (weight ratio 3:2), dissolve it completely in about 60 cm, and measure the maximum absorption using the colorimeter. Measure the absorbance at the wavelength. In addition, using the modified polyester fiber taken out from the sample before dyeing, a calibration curve showing the relationship between absorbance and dyeing rate was obtained in the same manner as described above, and from this calibration curve, the colorant content (b %owt).

From the colorant content in the sheath (a%ov!) and the colorant content in the core (b%owt), (a/b)X100
Accordingly, the ratio of the colorant content in the sheath to the colorant content in the core is calculated.

The polyamide constituting the sheath portion of the core-sheath composite fiber of the present invention contains a predetermined amount of carboxyl groups, which will be described later.

In order to make the sheath polyamide contain carboxyl groups,
This can be achieved by graft polymerizing the hydrophilic vinyl carboxylic acid onto the polyamide by heat treatment in an aqueous solution containing a hydrophilic vinyl carboxylic acid such as acrylic methacrylic acid and a graft polymerization initiator.

Hydrophilic vinyl carboxylic acids such as acrylic acid and methacrylic acid may be used alone or in combination of two or more. As a graft polymerization initiator, an organic peroxide such as benzoyl peroxide may be used, but it is better to use ammonium persulfate and sodium formaldehyde sulfoxylate in combination to more selectively graft polymerize hydrophilic vinyl carboxylic acid to the polyamide sheath. possible and preferred.

From the viewpoint of preventing dyeing of the cationic dye to the sheath polyamide and increasing dyeing fastness, it is preferable to carry out the graft polymerization step before the dyeing step.

The amount of carboxyl groups contained in polyamide is 7X10
-' to 5X10-3 equivalents/g polyamide, preferably 1x10''3 to 4X10-3 equivalents/g polyamide.If the carboxyl group weight is less than 7X10-' equivalents/g polyamide It is difficult to obtain sufficient performance functions such as hygroscopicity and deodorizing properties, and on the other hand, if the amount exceeds 5X10-3 equivalent/g polyamide, the texture becomes sticky, the color fastness is poor, and the sheath part peels off. As a result, the product becomes unsatisfactory.

In the present invention, the amount of carboxyl groups is determined as follows.

(1-(1/1+gr))/M (Equivalent weight: 7g polyamide) where gr is graft ratio (%)/100.
M represents the molecular weight of the hydrophilic vinylcarboxylic acid monomer.

In addition, even if the sulfonated aromatic dicarboxylic acid-modified polyester component, which is the core of the composite fiber of the present invention, is subjected to graft polymerization treatment under the above conditions, no weight increase was observed before and after the treatment. is one that does not undergo graft polymerization.

In the present invention, carboxyl group refers to free -COO
In addition to H, it refers to any salt state in which hydrogen ions are replaced with other cations.

The carboxyl group introduced by graft polymerization as described above can be optionally used as a metal salt or as a quaternary salt, depending on the desired performance.
Can be made into ammonium salt. For example, Na,
In addition, when the carboxyl group is substituted with an alkali metal ion such as Li, parent wood performance that is effective in improving hygroscopicity, antistatic property, antifouling property, refractory property, etc. is expressed. In addition, when substituted with quaternary ammonium ions such as lauryldimethylbenzyl ammonium chloride, tetrabutylammonium bromide ion, and octylpyridium chloride, antibacterial and
Anti-mold performance is developed. Further, if the dye remains in the finished state, that is, in the state of free carboxylic acid, ammonia deodorizing performance is exhibited.

It is also possible to simultaneously express different types of functions by combining ions that substitute carboxyl groups, and these can be selected as appropriate depending on the purpose.

The substitution treatment of these carboxyl groups can be carried out by a hot water bath treatment at 40 to 90° C. containing necessary chemicals.

For example, in the case of forming a Na salt, it may be treated in an aqueous solution of 3 to 12 g/l of a basic sodium salt such as soda ash (at a bath ratio of 1:30) at 80° C. for 30 minutes. When all the carboxyl groups are Na salts, the necessary amount of the basic sodium salt to be used is approximately 5 times the equivalent of the carboxyl groups contained in the sheath polyamide. In addition, when the amount is equal to or less than the equivalent of the carboxyl group contained in the sheath polyamide, the polyamide contains both Na salt of carboxylic acid and free carboxylic acid, and can impart hydrophilic performance and ammonia deodorizing performance.

The polyamide referred to in the present invention refers to polyε-cabrothymide (
Nylon 6), polyhexamethylene adipamide (nylon 66) are typical examples, but polyamides obtained from other polymerizable monomers, such as laurolactam, sebacic acid, paraxylylene diamine, isophthalic acid, etc. These copolyamides may also be used.

In addition, modified polyamide in which a compound having a sulfone group is bonded to the polyamide chain or a part of the terminal, or
It may also be a modified polyamide which is a compound having a sulfonic group and is obtained by adding a sulfonated aromatic dicarboxylic acid in the form of a free acid or an alkyl ester during polyamide polymerization and copolymerizing it.

Furthermore, a typical example of the sulfonated aromatic dicarboxylic acid is 5-sulfoxyisophthalic acid or a salt thereof represented by the following chemical formula.

When using a polyamide copolymer modified with a sulfonated aromatic dicarboxylic acid, a skeleton is formed from the viewpoint of exhibiting the original effects of the modified polyamide and ensuring that the desirable mechanical properties inherent to the polyamide are not impaired. The amount is preferably about 0.25 to 3 mol % based on the polyamide monomer.

Polyamide may contain a matting agent such as titanium oxide, but in order to sufficiently transmit the color of the core polyester and obtain excellent color development, matting agents and other pigments must not be added. , it is preferable that it is substantially not included.

Further, these polyamides may contain an antistatic agent, a heat resistant agent, a light resistant agent, etc. in an amount that does not significantly reduce the light transmittance.

In the core-sheath composite fiber of the present invention, as the modified polyester used as the core, a modified polyester in which a compound having a sulfone group is contained in a part of the chain or end of the polyester is used.
Those described in Publication No. 7 can be used.

This modified polyester is a modified polyester obtained by copolymerizing polyethylene terephthalate, polybutylene terephthalate, or a copolymerized polyester containing these as main components with a sulfonated aromatic dicarboxylic acid or a salt thereof.

A typical example of such a sulfonated aromatic dicarboxylic acid is 5-sulfoxyisophthalic acid represented by the above chemical formula or a salt thereof.

These dicarboxylic acids are added in the form of free acids or alkyl esters during polyester polymerization and copolymerized to produce modified polyesters.

The amount of copolymerization of the sulfonated aromatic dicarboxylic acid is determined so that the modified polyester exhibits the desired effect and also prevents the crystal structure of the modified polyester from being disordered and causing undesirable phenomena such as a significant decrease in mechanical properties. The amount is preferably about 0.5 to 6 mol% based on terephthalic acid.

Note that these modified polyesters may contain an antistatic agent, a light-resistant agent, a heat-resistant agent, a matting agent, and the like.

In the core-sheath composite fiber of the present invention, modified polyester is used in the core, and the colorant content in the sheath is 10% or less of the colorant content in the core, as described above.In other words, Since 90% or more of the coloring agent is contained in the core, the modified polyester core is sufficiently colored, but the polyamide sheath is hardly colored.

Therefore, when the sheath polyamide is selectively graft-polymerized after the dyeing process, there is almost no coloring agent, that is, dye or pigment, which inhibits graft polymerization in the sheath polyamide, so it is sufficiently efficient (graft polymerization is not achieved). can do.

Graft-polymerized polyamides generally have lower levels of light fastness and washing fastness, but in the case of the core-sheath composite fiber of the present invention, the colorant on the polyamide component side, which is the grafted sheath part, That is, since the dye and pigment content is as low as 10% or less, the decrease in color fastness can be minimized.

In addition, the colored graft-polymerized core-sheath composite fiber of the present invention has the abrasion resistance inherent to polyamide and is easily processed with resin.

Furthermore, since it has a modulus between that of polyamide and polyester, it can impart desirable tension and stiffness to the fabric, and as a secondary effect, it improves the dimensional stability when wet, which is considered to be a disadvantage of polyamide. It can also exhibit an improving effect and an anti-wrinkle effect.

Hereinafter, it will be explained in more detail with reference to Examples.

[Example] Each evaluation method is shown below.

<Graft ratio> It was expressed as the weight increase rate (%) of the dyed sample (before graft polymerization) and after graft polymerization. The absolute dry weight of each sample was measured.

<Hygroscopicity> A completely dried workpiece is placed in an atmosphere of 20°C and 65% RH for 2 hours.
After standing for 4 hours, the weight was measured and calculated using the following formula.

<Ammonia gas adsorption property> 0.2 ml of 30% ammonia water was dropped into a 500 ml wide-mouthed bottle with a tight stopper, and then 20 g of the material to be treated was added, and the bottle was tightly stoppered. Then, after standing for 20 minutes, the residual ammonium odor was smelled and evaluated on the following three scales.

×: Strong residual ammonia odor: Poor △: Moderate residual ammonia odor: Slightly poor ○: Slight to no residual ammonia odor: Good antibacterial properties> AATCCTe5t Method 90 (1977)
It was expressed by the width of the clear zone.

tyv azone - clear zone and diameter of sample - width of sample diameter (,)2 <Light fastness> Measured by the method of JIS L 0842.

<Washing fastness> Measured according to the method of JIS L 0844. however,
Discoloration was measured by comparing the difference in color observed between each color chart of the contamination gray scale and grading the degree of discoloration.

(Example 1, Comparative Example 1) 5-sulfoxyisophthalic acid was added to a polyethylene terephthalate raw material consisting of ethylene glycol and terephthalic acid in an amount of 1.5 mol% based on the terephthalic acid using a conventional method.
Add and polymerize, orthochlorophenol intrinsic viscosity IV
is 0.64 modified polyethylene terephthalate (hereinafter referred to as
Modified polyester) was obtained.

This modified polyester and nylon 6 with a sulfuric acid relative viscosity of 2.62, which does not substantially contain titanium oxide, are subjected to an extruder type composite spinning machine, melted separately, then weighed in equal amounts, and placed in the composite spinning pack section. A composite flow is formed with modified polyester as a core and nylon 6 as a sheath, and is discharged, taken off at a speed of 1500 m/min, and then heated at 160°C.
The yarn was heat-set with a hot drawing roller and wound at 4000 m/min to obtain a drawn yarn of 24 filaments of 70 denier.

This drawn yarn is subjected to warp and weft yarns, and a plain woven fabric (warp density 11
8 threads/1 nch, weft density 85 threads/1 nch). This plain woven fabric was placed in a treatment bath containing 2 g/l of "Sanded" G-29 (manufactured by Sanyo Chemical Co., Ltd.) and 2 g/l of soda ash 5 g/1% "Butrol" WR-14 (manufactured by Kaisei Chemical Co., Ltd.). After de-sizing and scouring at 98° C. for 20 minutes, it was dried and subjected to intermediate setting at 170° C. to obtain a sample fabric for dyeing and graft polymerization.

The sample fabric was dyed with cationic dye “Diacryl Red”.
GRL-N″conc (manufactured by Mitsubishi Chemical Corporation) 0.5%
owt, and dyed at 120° C. for 30 minutes in a bath containing 0.5 cc of acetic acid (80%) as an auxiliary agent (sample for Example 1).

In addition, for comparison, the above sample fabric was mixed and dyed under the following conditions. Cationic dye “Diacryl RedG R
L-N” (manufactured by Mitsubishi Chemical Corporation) 0.25% owt, acid dye “formerly acid AxoJubiol 3GS”
250% (manufactured by Mitsubishi Chemical Corporation) 0.25%owt
, “Ospin 700-CD” (Tokai Oil Co., Ltd.) as an auxiliary agent
(manufactured by) in a bath of 0.5% owt, acetic acid 0.5cc/I, 12
It was stained at 0° C. for 30 minutes (sample for Comparative Example 1).

These colored fabrics were mixed with 20% of mixed vinyl carboxylic acid monomer, which is a mixture of acrylic acid and methacrylic acid at a weight ratio of 1:1.
% ovf, ammonium persulfate 1% owt.

Sodium formaldehyde sulfoxylate 3%ow
Place each sample separately in an aqueous solution adjusted to 75
Graft polymerization was carried out by heat treatment in a bath at ℃ for 30 minutes. Next, after washing with hot water and water, drying at 20°C and 65%
The humidity was adjusted to RH, and the weight increase rate before and after the graft polymerization process was calculated.

Next, in a soda ash aqueous solution of Log/A', 80°C, 3
The fibers were heat-treated in a bath at a bath ratio of 1:30 for 0 minutes to carry out graft polymerization, and the carboxyl groups introduced into the fibers were replaced with Na.

Next, after washing and drying the Na-substituted fabric, each sample was divided into three equal parts, and one part was treated in an aqueous solution containing 20% OVF of acetic acid at 80°C for 30 minutes to convert the carboxyl groups into carboxylic acids. did. The remaining portion was treated with an aqueous solution containing 10% owt of lauryldimethylbenzylammonium chloride as a pure component at 80° C. for 30 minutes to convert the carboxyl group to lauryldimethylbenzylammonium salt.

In this way, samples with three types of carboxyl groups, Na salt type, acid type, and quaternary ammonium salt type, were obtained (Example 1 and Comparative Example 1).

The resulting samples were evaluated for dye exhaustion rate (core and sheath), grafting rate, moisture absorption rate, ammonia gas adsorption performance, antibacterial properties, and light and washing fastness. The results are shown in Table 1.

As is clear from the results in Table 1, the sample obtained in Example 1 not only had the desired functionality but also had high light fastness and washing fastness. However, when a large amount of dye is present on the polyamide side as in Comparative Example 1, graft polymerization is hardly achieved and the desired functionality cannot be obtained.

The core/sheath composite ratio of the core/sheath composite yarn used in the examples was 1:1, and the moisture absorption rate of the raw fiber without grafting or Na chlorination treatment was about 2%.

Due to the presence of modified polyester in the sheath, the texture of these fabrics has the tension and waist characteristic of polyester.
It was more preferable than nylon 6 alone.

(Example 2) 1.5 mol% of 5-sulfoxyisophthalic acid was added to the terephthalic acid in a conventional manner to a polyethylene terephthalate raw material consisting of ethylene glycol and terephthalic acid, and the resulting polymerization resulted in orthochlorophenol having an intrinsic viscosity of IV0.
．． 64 modified polyester was obtained.

Renol Blue^2R- is added to the above modified polyester.
AT (manufactured by Hoechst Japan ■) 2.0w1% was uniformly blended to obtain a colored modified polyester polymer.

This colored modified polyester and nylon 6 with a sulfuric acid relative viscosity of 2.62, which does not substantially contain titanium oxide, are subjected to an extruder type composite spinning machine, melted separately, and then weighed in equal amounts to form a composite spinning pack. A composite flow was formed with modified polyester as a core and modified nylon 6 as a sheath, and was discharged and taken at a speed of 1500 m/min.
The yarn was wound up at a speed of 24 filaments of 70 denier to obtain a drawn yarn of 24 filaments.

This drawn yarn is subjected to warp and weft yarns, and a plain woven fabric (warp density 11
8 threads/1 nch, weft density 85 threads/1 ncb). This plain woven fabric was coated with “Sanded” G-29 (manufactured by Sanyo Chemical) 2g/1. Soda ash 5g/L “Butrol”
After desizing was performed in a treatment solution containing 2 g/l of WR-14 (manufactured by Meisei Kagaku Kogyo ■) at 98°C for 20 minutes, it was dried and subjected to intermediate setting at 170°C.

This colored fabric was then subjected to the same graft polymerization and substitution treatments as in Example 1.

The resulting samples were evaluated for dye exhaustion rate (core and sheath), grafting rate, moisture absorption rate, ammonia gas adsorption performance, antibacterial properties, and light and washing fastness. The results are also shown in Table 1.

As is clear from the results in Table 1, the sample obtained in Example 2 not only had the desired functionality but also had high light fastness and washing fastness. However, when a large amount of dye is present on the polyamide side as in Comparative Example 1, graft polymerization is hardly achieved and the desired functionality cannot be obtained.

Due to the presence of modified polyester in the sheath, the texture of these fabrics has the tension and waist characteristic of polyester.
It was more preferable than nylon 6 alone.

(Example 3) Evaluation of moisture absorption rate, ammonia gas adsorption performance, and antibacterial property of a sample in which the same carboxyl group substitution treatment as in Example 1 was performed without dyeing the intermediate-set fabric in Example 1. I did this. The results are also shown in Table 1.

(Comparative Examples 2 and 3) Using a drawn yarn of 70 denier and 24 filaments of nylon 6 obtained by a conventional method, a plain weave similar to that in Example 1 was woven, and the same plain weave as in Example 1 was scrutinized, intermediate set, and the portion was dyed. Post-graft polymerization processing (Comparative Example 2), the remaining part was grafted without dyeing, and then the same substitution treatment as in Example 1 was performed without dyeing (Comparative Example 3).

However, the staining conditions were as follows.

Acidic dye “Diacid A!o, Rubine 3G
Dyeing was carried out at 100° C. for 30 minutes in a bath containing 0.5% OVF of S″250% (manufactured by Mitsubishi Chemical Corporation) and 0.5 cc/l of acetic acid as an auxiliary agent.

The resulting samples were evaluated for dye exhaustion rate (core and sheath), grafting rate, moisture absorption rate, ammonia gas adsorption performance, antibacterial properties, and light and washing fastness. The results are also shown in Table 1.

As is clear from the results in Table 1, compared to Example 1.2,
When a large amount of dye is present on the polyamide side, as in Comparative Example 2, graft polymerization is hardly achieved and the desired functionality cannot be obtained.

In addition, when dyeing is performed after graft polymerization as in Comparative Example 3, the graft polymerization is sufficiently achieved and the desired functionality is obtained, but the light fastness and washing fastness are insufficient, and development as a product is difficult. Have difficulty.

[Effects of the Invention] The core-sheath composite fiber of the present invention not only maintains excellent light fastness and washing fastness, but also has hydrophilic properties such as moisture absorption and antistatic properties depending on the type of carboxyl group contained inside the fiber. Functions such as ammonia deodorizing properties, antibacterial properties, etc. can be easily imparted.

Because the core-sheath composite fiber of the present invention has such functions and characteristics, it can be applied to outer and inner materials for spring and summer, fields that have traditionally been difficult to use with synthetic materials due to lack of moisture absorption performance. Become.

For example, it is suitable for sports slacks such as golf slacks, spring/summer jackets, skirts, and work clothes such as office wear and nurse wear.

Furthermore, it is suitable for sports linings, linings for general clothing, etc., which have been difficult to develop due to nylon's lack of dimensional stability.

By imparting ammonia deodorizing or antibacterial properties, it can be suitably used for bedclothes such as sheets, futon fabrics, futon covers, etc., especially hospital curtains, diaper covers, etc.

Claims (5)

[Claims] (1) A core-sheath composite fiber with a sheath made of polyamide and a core made of sulfonated aromatic dicarboxylic acid-modified polyester, wherein the polyamide has carboxyl groups of 7 x 10^-^4~
A core-sheath composite fiber containing 5×10^-^3 equivalent/g polyamide. (2) A core-sheath composite fiber having a sheath made of polyamide and a core made of sulfonated aromatic dicarboxylic acid-modified polyester, wherein the polyamide has carboxyl groups of 7×10^-^4~
A core-sheath composite containing 5 x 10^-^3 equivalents/g polyamide, characterized in that the colorant content in the sheath is 0.2% owt or less and 10% or less of the colorant content in the core. fiber. (3) The core-sheath composite fiber according to claim 1, wherein the colorant is a cationic dye. (4) The core-sheath composite fiber according to claim 1, wherein the colorant is a pigment. (5) The core-sheath composite fiber according to claim 1, wherein the sheath portion is 20 to 75 wt%.