JPH086208B2 - Composite fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention has an ethylene-vinyl alcohol system which has a good feeling similar to natural fibers, good gloss and hygroscopicity, and is excellent in processability. The present invention relates to a composite fiber of a copolymer and a polyester, and more specifically, an ethylene-vinyl acetate copolymer saponified polymer and a polyester polymer obtained by copolymerizing a specific component and having a specific substance. The present invention relates to a composite fiber characterized in that

(Prior Art) Conventionally, a fiber structure such as a woven fabric, a knitted fabric, and a non-woven fabric made of a filament of a synthetic fiber such as polyester or polyamide has a monofilament denier or a monotonous cross-sectional shape of its constituent filaments, and thus cotton, hemp, or the like. Compared with the natural fiber, the texture and gloss were monotonous and cold, and the quality as a fiber structure was low.

Further, since the polyester fiber is hydrophobic, the fiber itself has a drawback that it is inferior in water absorption and hygroscopicity.

In recent years, various studies have been made in order to improve these drawbacks. Among them, hydrophobic fibers such as polyester and the like are compounded with a polymer having a hydroxyl group (OH group). Attempts have been made to impart properties such as hydrophilicity to the. Specifically, a composite fiber of a saponified ethylene-vinyl acetate copolymer and a hydrophobic thermoplastic resin such as polyester, polypropylene or polyamide is disclosed in JP-B-56-5846 and JP-B-55-1372. ing.

(Problems to be Solved by the Invention) The present invention imparts hydrophilicity to a polyester-based hydrophobic fiber by complexing a conventional polyester-based hydrophobic polymer and a polymer having a hydroxyl group (OH group), The purpose of the present invention is to obtain a synthetic fiber which is excellent in bulkiness and more similar to natural fiber, and the manufacturing conditions for that purpose have been clarified so that there is no trouble in polymer design, fiberizing processability and processing processability.

In particular, in order to obtain a good dye-processed fabric without producing a defect in the processing step, a composite fiber of a saponified product of an ethylene-vinyl acetate copolymer and polyester that can achieve the above-mentioned object is specifically This is to clarify what kind of thing to use and what kind of structure and conditions should be used.

The composite fiber of the ethylene-vinyl alcohol copolymer and the polyester has a characteristic that it is easily peeled off because the adhesiveness at the interface between the two-component polymers is small. However, depending on the purpose of use, it may be a cause of trouble. It was In particular, when stress is applied at right angles to the length direction of the fiber such as strong twisting and false twisting, a separation phenomenon between the two components occurs in some places, and the strong twisting yarn and false twisted yarn It is not preferable that a fabric is produced by using and dyed and processed, and the peeled portion looks white and becomes a defect.

It is a particular object of the present invention to provide a composite fiber of ethylene-vinyl alcohol copolymer and polyester which does not cause the above peeling phenomenon.

(Means for Solving the Problems) That is, the present invention is mainly composed of an A component consisting of an ethylene-vinyl alcohol copolymer having an ethylene copolymerization ratio of 25 to 70 mol% and an alkylene terephthalate unit, and having the following general formula: A polyalkylene terephthalate-based copolymer having 0.5 to 10 mol% of a copolymerized unit having a group represented by (I) with respect to a terephthalate unit, and the polyalkylene terephthalate-based copolymer in terms of metal
A composite fiber comprising a B component composed of 100 ppm or more of an alkyl metal or alkaline earth metal carboxylate,
The composite fiber is characterized in that the weight ratio of the A component to the B component is 10:90 to 90:10 and the A component forms at least a part of the fiber surface.

(However, A is an aliphatic group or an aromatic group, M is an alkali metal, an alkaline earth metal, or an alkylphosphonium group.) First, the A component polymer will be described in detail. The component A polymer, that is, an ethylene-vinyl alcohol copolymer is obtained by saponifying an ethylene-vinyl acetate copolymer, and a saponification degree of 95% or more is preferable. Copolymerization ratio is 25-70
Mol%, that is, vinyl alcohol component (including unsaponified vinyl acetate component, acetalized vinyl alcohol component, etc.) of about 30 to 75 mol% is used.
When the copolymerization ratio of the vinyl alcohol component in the component A polymer is low, naturally the properties such as hydrophilicity are deteriorated due to the decrease of hydroxyl groups (OH), and as will be described in detail later, the desired good hydrophilicity is obtained. A natural fiber-like texture having is obtained. On the contrary, when the copolymerization ratio of the vinyl alcohol component is too high, the melt moldability is deteriorated, and the spinnability becomes poor when the fiber is formed after composite spinning with the component B, and the single yarn breaks during spinning or drawing, The number of thread breaks increases. Therefore, it can be said that those having a high saponification degree and an ethylene copolymerization ratio of 25 to 70 mol% are suitable for obtaining the fiber of the present purpose.

When a high melting point polymer of polyester is used as the B component, it is preferable to improve the heat resistance during melt molding of the A component polymer in order to continuously and stably spin the composite fiber with the A component polymer. However, as a means for achieving this, it has been found that setting the ethylene copolymerization ratio in an appropriate range and further setting the metal ion content in the component A polymer to a predetermined amount or less are effective. A
The thermal decomposition mechanism of the component polymer is roughly divided into a case where a crosslinking reaction occurs between polymer main chains and a gelled product is generated, and a mechanism in which decomposition such as main chain cleavage and side chain elimination progresses. It is thought that it will occur as a result. Although details are omitted, it has been found that removing the metal ions in the component A polymer dramatically improves the thermal stability during melt spinning. Particularly, a remarkable effect can be obtained by setting the group I alkali metal ions such as Na ⁺ and K ⁺ ions and the group II alkaline earth metal ions such as Ca ²⁺ and Mg ²⁺ ions to 100 ppm or less. I knew there was. In particular, during melt spinning under high temperature conditions continuously for a long time, when gelled substance is generated in the component A polymer, the gelled substance is gradually clogged and deposited on the spinning filter, resulting in a spinning pack pressure. Will rapidly rise and the nozzle life will be shortened, and at the same time, single yarn breakage and yarn breakage during spinning will occur frequently. If the accumulation of the gelled substance further progresses, the polymer pipe may become clogged, which may cause troubles, which is not preferable. By removing Group I alkali metal and Group II alkaline earth metal in the component A polymer, a large amount of gelation occurs even during continuous operation for a long time during melt spinning at high temperature, especially at 250 ° C or more. I knew that the trouble caused by was unlikely to occur. It is more preferably 50 ppm or less, and particularly preferably 10 ppm or less.

As an example of the method for producing the component A polymer, ethylene and vinyl acetate are radically polymerized in a polymerization solvent such as methanol under a radical polymerization catalyst, and then unreacted monomers are expelled to cause a saponification reaction with caustic soda. After being made into an ethylene-vinyl alcohol copolymer, it is pelletized in water, washed with water and dried. Therefore, in the process, alkali metal or alkaline earth metal is apt to be contained in the polymer, and usually several hundred ppm or more of alkali metal or alkaline earth metal is mixed.

As a method for reducing the content of alkali metal ions and alkaline earth metal ions as much as possible, during the polymer manufacturing process, after pelletizing after saponification treatment, the pellets in a wet state were washed with a large amount of a pure aqueous solution containing acetic acid. After that, it is obtained by further washing a large amount of pellets with only a large excess of pure water.

The component A polymer is produced by saponifying a copolymer of ethylene and vinyl acetate with caustic soda. As described above, the saponification degree at this time is preferably 95% or more. When the saponification degree is low, not only the crystallinity of the polymer is lowered and the fiber physical properties such as strength are lowered, but also the component A polymer is apt to be softened and troubles occur in the processing step and the obtained fiber is obtained. The texture of the structure is also bad, which is not preferable.

Another important requirement for obtaining the fiber of the present invention is
As the polymer component of B, a polyalkylene terephthalate-based copolymer, that is, a sulfone, which is mainly composed of an alkylene terephthalate unit and has 0.5 to 10 mol% of a copolymerized unit having a group represented by the general formula (I) with respect to the terephthalate unit. A polyalkylene terephthalate-based polymer in which an acid compound has been copolymerized is used.
That is, 100 ppm or more of an alkali metal or alkaline earth metal carboxylate is added.

The polyalkylene terephthalate-based copolymer referred to in the present invention comprises terephthalic acid as a main acid component and at least one glycol, preferably at least one selected from ethylene glycol, trimethylene glycol, tetramethylene glycol and hexamethylene glycol. It means a polyester whose main glycol component is a seed alkylene glycol. Further, it may be a polyester in which a part of the terephthalic acid component is replaced with another difunctional carboxylic acid component, or a polyester in which a part of the glycol component is replaced with a diol component other than the glycol.

Examples of the bifunctional carboxylic acid other than terephthalic acid used here include isophthalic acid, naphthalene dicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, β-hydroxyethoxybenzoic acid, p
Examples thereof include aromatic, aliphatic, and alicyclic bifunctional carboxylic acids such as oxybenzoic acid, adipic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid. Also,
Examples of the diol compound other than the glycol include diethylene glycol, neopentyl glycol,
Examples thereof include aliphatic, alicyclic and aromatic diol compounds such as cyclohexane-1,4-dimethanol, polyethylene glycol, polytetramethylene glycol, bisphenol A and bisphenol S.

As the sulfonic acid compound having a group of the formula (I) used as a copolymerization component in the method of the present invention, it is preferable to use a compound in which A in the formula is an aromatic group in terms of heat resistance during polymerization.

 The sulfonic acid compound has the general formulaAnd a compound represented by the formula:₁Is ester formation
Showing a functional group, as a specific example,CH_{2 a}OH, -OCH_{2 b}O (CH₂)_{b d}OH, Etc. can be given. X₂Is X₁Same as or different from
Represents an ester-forming functional group or a hydrogen atom.
It is preferably a stealth-forming functional group. M is Natori
Alkali metals such as um, potassium, etc.
Potassium earth metal or alkylphosphonium group
It Examples of alkylphosphonium groups include tetra-n
-Butylphosphonium group (P (N-Bu)_Four), Butyl
Triphenylphosphonium group (P (C₆H_Five)_Three(C
_FourH₉)), Ethylbutylphosphonium group (P (C₂H_Five)
(C_FourH₉)_Three) Etc.

Another important thing for the polymer of the component B is to contain an alkali metal salt or an alkaline earth metal carboxylate in an amount of 100 ppm or more in terms of metal. Examples of the carboxylic acid salt include sodium acetate, calcium acetate, potassium terephthalate, sodium benzoate, and the like, and an acetate compound is particularly preferable. By using a polymer in which a carboxylate of an alkali metal or an alkaline earth metal is contained in the polyester copolymerized with the sulfone compound described above, the adhesiveness with the component A polymer is dramatically improved, It has been discovered for the first time that the whitening phenomenon of the dyed product caused by peeling in the processing step eliminates defects such as streaks. In particular, even when a processing process such as strong twisting or false twisting that applies a strong stress to the fiber in the transverse direction is applied, the A component polymer and B
It has been found that the good adhesion of the component polymers is fibrous to give good dyed fabrics without defects. In addition, it has been found that, among the salts of alkali metals or alkaline earth metals, particularly the carboxylic acid salt has a remarkable effect in preventing peeling of the component A polymer and the component B polymer.

The copolymerization amount of the sulfonic acid compound must be 0.5 mol% or more based on terephthalic acid. If it is less than 0.5 mol%, the adhesiveness to polyester is insufficient, which is not preferable. If it exceeds 10 mol%, the adhesiveness will be good, but the fiber forming processability, especially the spinnability and stretchability will be poor, and only low fiber strength will be obtained, which is not preferable.

Specific sulfonic acid compounds include 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, 5-tetrabutylphosphonium sulfoisophthalic acid, 2,6-dicarboxynaphthalene-4-sulfonic acid tetrabutylphosphonium salt, α -Tetrabutylphosphonium sulfosuccinic acid and the like can be mentioned, among which 5-
Alkali metal sulfoisophthalic acid compounds are also preferred.

In addition, the alkali metal or alkaline earth metal carboxylate contained at the same time is 100 p
It is preferable to add pm or more. If it is less than 100 ppm, even if the sulfonic acid compound is within the above range,
Adhesion with the A polymer is not sufficient, which is not preferable.
However, if the amount of the metal salt compound is 20000 ppm (2 wt%) or more, the fiber forming processability becomes poor, which is not preferable. A polyester obtained by copolymerizing a predetermined amount of a sulfonic acid compound, and by containing a predetermined amount of a carboxylate of an alkali metal or an alkaline earth metal, the adhesiveness with an ethylene vinyl alcohol copolymer, which is a component A polymer, becomes good for the first time. I have found that.

It is currently speculative as to why an effect not seen with conventional ethylene-vinyl alcohol copolymers and polyesters as described in the present invention can be speculated at this time, but is probably bound in the polyester molecule. The sulfonic acid polar group and the hydroxyl group bonded in the ethylene-vinyl alcohol copolymer molecule interact with each other to develop adhesiveness, and further, the coexisting alkali metal or alkaline earth metal It is believed that the carboxylate salt assists the interaction between both polymer components. Further, it is considered that the hydrophilicity of the hydroxyl group of the ethylene-vinyl alcohol copolymer and the hydrophilicity of the sulfonic acid compound in the polyester develop the affinity through the hygroscopicity of the carboxylate of alkali metal or alkaline earth metal. To be

Such polyesters can be synthesized by any method. For example, polyethylene terephthalate will be described. Usually, terephthalic acid and ethylene glycol are directly esterified, or a lower alkyl ester of terephthalic acid such as dimethyl terephthalate is transesterified with ethylene glycol, or terephthalic acid and ethylene glycol are used. The first step reaction of reacting with oxide to form a glycol ester of terephthalic acid and / or its low polymer, and heating the reaction product of the first step under reduced pressure until a desired degree of polymerization is reached. It is produced by the second stage reaction of polycondensation reaction. The sulfonic acid compound to be copolymerized may be added at any stage before the synthesis of the polyester is completed, preferably at any stage before the completion of the reaction in the first stage. The alkali metal or alkaline earth metal carboxylate may be added by being dispersed in ethylene glycol in the initial stage of the reaction of the first stage.

Further, the composite ratio of the A component polymer and the B component polymer is preferably 10 to 90% by weight of the A component polymer. Composite fibers with an A polymer content of less than 10% by weight are
Naturally, due to the reduction of hydroxyl groups, one of the features of the fiber such as hydrophilicity is lost. Also, the A polymer content is 90
When the content is more than 10% by weight, the A polymer, which is slightly inferior in spinnability, becomes a litch, resulting in poor processability such as spinning and drawing.
In addition, the A polymer becomes a litch in the fiber surface layer, and the hand is often unfavorable because the degree of sticking between the single fibers becomes severe and it becomes hard.

Next, an example of the composite shape of the composite fiber of the present invention is shown. A model diagram of a concrete composite form is shown in FIGS. 1 to 17 as an example. 1 and 2 are core-sheath type cross sections. 3 and 4
The figure shows a laminated composite cross section. Figures 5-7 are multilayer composite cross sections. FIGS. 8 to 11 show a type in which the fibers are joined and compounded in the direction of the center of the fiber cross section, which is a compound type in which only the A component is divided into a plurality or the B component is divided into a plurality. FIG. 12 shows an example of a hollow cross-section fiber, which is a type in which an A component and a B component are separately divided and combined in an annular shape. FIG. 13 shows an example of a type in which the A polymer component and the B polymer component are separated and compounded in the central direction of the fiber cross section. FIG. 14 and FIG. 15 are examples of composite shapes of modified cross-section fibers. FIG. 16 is an example of a heterogeneous mixed composite shape of A polymer and B polymer. This is 4-8 A polymer and B polymer immediately before being discharged from the spinning nozzle.
It is obtained by appropriately layer-dividing with an element static mixer and then discharging from a nozzle hole. 17th
The figure is an example of a core-sheath composite shape in which the core component is the B polymer and the sheath component is the polymer blend component of the A polymer and the B polymer. In the case of such a composite fiber, in order to exert the hydrophilicity and the feeling improving property of the component A polymer, at least a part of the surface of the composite fiber, preferably 10% of the surface is used.
The above needs to be covered with the A component polymer.

Needless to say, the effect of the present invention can be expected not only for long fibers but also short fibers as the fibers obtained by the present invention.

Further, the fiber obtained in the present invention is formed into a shape similar to pentagonal or hexagonal by a higher-order processing such as false twist crimping, or a trilobal shape, a T-shape, or a 4-shape due to a modified cross-section nozzle during spinning. Even if it is a leaf shape, a multi-leaf shape such as a six-leaf shape, or an eight-leaf shape, and various cross-sectional shapes, the point is that a fiber satisfying the requirements described so far has a good texture and a good texture of the present invention. It is possible to obtain a fiber structure that retains the fiberizing processability and processing processability.

Further, the A polymer is a polymer having a melting point of about 150 to 180 ° C., and the phenomenon of melting point lowering actually occurs in hot water, and it tends to soften even at 150 ° C. or lower. Therefore, B
When polyester is used as the polymer, it can be easily made under normal dyeing conditions for polyester fiber fabrics and set temperatures of fabrics.
When the exposed surface area of the component A polymer is large in the composite shape of the fiber cross-section because the component polymer is easily softened,
Depending on the processing conditions, a softening phenomenon occurs, leading to a sticking phenomenon between single fibers. When it is desired to adjust the hardness of the texture due to the sticking phenomenon to some extent, it is possible to improve the heat resistance and hot water resistance by subjecting the component A polymer to a molecular crosslinking treatment. For the cross-linking reaction, a known general method can be used, for example, an organic cross-linking agent such as divinyl compound, formaldehyde, dialdehyde, diisocyanate, or a cross-linking with an inorganic cross-linking agent such as a boron compound, γ line,
A crosslinking reaction by radiation such as an electron beam or light may be used.
The crosslinked structure can be introduced by copolymerization with a polymer having a crosslinked structure in advance. Further, during the polymerization, a crosslinking reaction can be performed after the fiber formation. As a suitable example, it is convenient to carry out the acetalization reaction after forming a fabric from the composite fiber composed of the A component and the B component.

An example of specific conditions for the acetalization treatment of the fiber of the present invention is as follows: Sulfuric acid, formic acid, hydrochloric acid, or other strong acid is used as the acetalization reaction catalyst, and the concentration of the strong acid used is 0.05.
Set above the regulation and below 5 regulations. Then OHC-CnH ₂ n-
CHO (n = 0-10) dialdehyde 0.2g / more, 500g
The fiber may be treated at a reaction temperature of 15 ° C or higher and 135 ° C or lower as a solution having a concentration of / or less. When dialdehyde is used as the aldehyde to be used, acetalization with dialdehyde may leave a non-crosslinked free aldehyde in addition to the crosslinked reaction, and this aldehyde may cause discoloration of the dyeing on heating. There is a case. In order to prevent this, it is preferable to oxidize free aldehyde with an oxidizing agent to form a carboxylic acid or a carboxylic acid salt.

Further, since the component B polymer is polyester, it is possible to further impart a soft texture by subjecting the cloth to alkali reduction treatment with a caustic soda solution.

Furthermore, when high-temperature high-pressure dyeing is performed to dye the B component polymer, if unfavorable shrinkage of the fabric based on the A component polymer part occurs under the conditions of high temperature hot water, strong acid is added to the dyeing solution during dyeing. The presence of a strong base salt or boric acid alone or in a mixture of both can prevent undesired shrinkage during dyeing.

The main applications of the fibers obtained in the present invention include staples for clothes, dry non-woven fabrics and wet non-woven fabrics. Of course, 100% of the fiber of the present invention may be used, or the effect of the fiber of the present invention can be obtained even if a part of the fiber of the present invention is mixed with other fibers to produce a non-woven fabric or the like. However, it goes without saying that the effects described in the present invention cannot be sufficiently obtained unless the fibers of the present invention are mixed in a certain ratio or more. Further, the fibers of the present invention can be obtained as long fibers and have a good feeling, and are suitable for outer garments or the like in the form of woven fabric or knitted fabric.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples below.

The intrinsic viscosity of the polymer was measured by using an Uberode-type viscometer in a constant temperature bath at 30 ° C. using an equivalent solvent mixture of phenol and tetrachloroethane for polyester. The saponified ethylene vinyl acetate copolymer was measured at 30 ° C. using 85% aqueous phenol.

Example 1 Using methanol as a polymerization solvent, radical polymerization of ethylene and vinyl acetate was carried out at 60 ° C. to prepare a random polymer having an ethylene copolymerization ratio of 44 mol%, and then saponification was carried out with caustic soda. After saponifying ethylene vinyl acetate copolymer with a degree of 99% or more, wash the polymer in a wet state with a large excess of pure water containing a small amount of acetic acid, and then with a large excess of pure water. Repeatedly, alkali metal ions of K and Na and Mg and Ca in the polymer
The alkaline earth metal ion content of each is about 10 ppm or less, and then water is separated from the polymer by a dehydrator, and further vacuum dried at 100 ° C. or less to sufficiently perform intrinsic viscosity [η] = 1.05 dl / I got g. This polymer is A
It was used as a component polymer.

As the B component polymer, terephthalic acid (TA) and ethylene glycol (EG) are mixed, and the molar ratio of EG and TA is 1.5,
Furthermore, the sodium acetate content in the polymer was added to the EG / TA mixture so that it would be 1200 ppm to prepare a slurry.
b ₂ O ₃ 100 ppm was added. This slurry is supplied to an esterification tank with an internal temperature of 240 ° C for two and a half hours for esterification, and then 5-sodium sulfoisophthalic acid is added in a small amount such that the copolymerization amount (ratio to TA) is 2.5 mol%. EG
To 40 ° C over 40 minutes to raise the temperature to 270 ° C to complete the reaction, then transfer to a polymerization tank with an internal temperature of 290 ° C and gradually reduce the pressure to 1 mmHg or less to polymerize and add nitrogen. It is extruded into water in a strand by pressure and cut [η] =
0.55 chips each were obtained. This was used as the B component.

A component and B component are separately melt-extruded by an extruder, separately weighed by a gear pump, and in a composite ratio of 50/50, a core-sheath type cross section with the A component as the sheath and the B component as the core as shown in FIG. The composite was spun and spun at a spinning speed of 1000 m / min.

The obtained spun raw yarn was drawn by ordinary roller plate drawing, and after drawing, a multifilament of 50 denier 36 filament was obtained. The drawn yarn obtained is S twist 2500 T / m
And Z twist 2500 T / M strong twist, and then the strong twist yarn is heated to 50 ° C.
It was treated with warm water for 30 minutes to stop the twisting. Using the twisted hard twist yarn as warp and using it as weft, two S and Z twists were alternately arranged to weave a satin-dyed woven fabric. On the other hand, false-twisted yarn was prepared by carrying out false-twisting processing of multifilament drawn yarn of 50 denier 36 filament at 130 ° C. under the condition of 3500 T / m. Then, a plain fabric was woven using the processed yarn as warp and weft.

Actinol R-1001 g /
After desizing at 80 ℃ for 20 minutes, 90 ℃ in 0.3N sulfuric acid aqueous solution containing 2g / glutardialdehyde
Acetalization for 50 minutes under the following conditions (abbreviated as GA below)
Processed. Then, the product was set at 180 ° C., dyeing was carried out under the following conditions, and then the dry finishing set was carried out by a conventional method.

The obtained woven fabric had good colorability, softness and bulkiness, and had a good texture similar to that of natural cotton fiber having a squeezing feeling. In addition, the fiberizing processability was good and there was no problem.

Further, the woven fabric after dyeing was good without any whitening phenomenon due to peeling at the interface of the core-sheath, either for the strongly twisted yarn or for the false twisted yarn. The surface of the woven fabric was magnified and projected with a video microscope manufactured by Myojin Kogyo Co., Ltd., but the sheath component did not fall off due to peeling and no puncture-like defect was found. The sodium acetate added during the polymerization was present in the B component polymer with almost no change.

Dyeing method Examples 2 to 12 Carried out in the same manner as in Example 1 and performed under the condition B shown in Table 1.
The amount of 5-sodium sulfoisophthalic acid copolymerized in the component polymer was changed, the content of sodium acetate was changed, the weight ratio of the A component and the B component was changed, and the cross-sectional shape was changed. The results are shown in Table 1. In each case, a good dyed fabric having good fiberizing processability, good feeling, and no defect of dyeing unevenness due to peeling of the A component and the B component was obtained.

Examples 13 and 14 In Example 13, 3,5-dicarboxybenzenesulfonic acid tetra-n-butylphosphonium salt was used as a copolymerization component of the sulfonic acid compound of the component B polymer, and Example 14 was
The same procedure as in Example 2 was carried out except that calcium acetate was used as the carboxylic acid salt contained in the B component polymer. The results are shown in Table 1. In each case, a good dyed fabric having good fiberizing processability, a good feeling, and no dyeing spots due to peeling was obtained.

Examples 15 and 16 Fiber formation was carried out by the same method as in Example 1 except that the saponified ethylene-vinyl acetate copolymer used as the component A polymer was changed in the ethylene copolymerization ratio. Example 15 has an ethylene copolymerization ratio of 32 mol%,
Example 16 was carried out using an ethylene copolymerization ratio of 56 mol%. Both have good processability and good texture,
A good dyed woven fabric having no stain due to peeling was obtained.

Comparative Examples 1 and 2 Example 1 except that the copolymerization amount of 5-sodium sulfoisophthalic acid in the B component polymer was 2.5 mol%, the content of sodium acetate was 0 in Comparative Example 1 and 200 ppm in Comparative Example 2. It carried out on the same conditions. After dyeing the fabric, white and brown portions due to peeling were observed in some places.

Comparative Examples 3 to 5 Sodium acetate content of B component polymer was 1200 ppm
As Comparative Example 3, the co-weight of 5-sodium sulfoisophthalic acid was zero in Comparative Example 3, 0.1 mol% in Comparative Example 4, and 15 mol% in Comparative Example 5, and the same conditions as in Example 1 were carried out.
Comparative Examples 3 and 4 were dyed-up woven fabrics, and a white brown portion was generated due to slight peeling.

 In Comparative Example 5, both spinnability and stretchability were poor.

Comparative Examples 6 and 7 The same polymer as in Example 1 was used, and the composite ratio of the A component and the B component was changed to 5/95 and 95/5, respectively. In all cases, the spinnability was not very good.

Comparative Examples 8 and 9 The same procedure as in Example 1 was carried out except that the ethylene copolymerization ratio of the A component polymer was changed and other conditions were used. In Comparative Example 8, the spinnability was extremely reduced due to the poor spinnability of the component A polymer. Also, if spinning is continued for a long time,
At the same time that the gelled product of the component A polymer was clogged in the spinning filter, a large amount of gelled product was also mixed in the fibers, and the spinnability was further deteriorated. The stretchability was also very poor, and a woven fabric whose texture could be evaluated could not be obtained.

In Comparative Example 9, the ethylene copolymerization ratio was 80 in the component A polymer.
Although the content of mol% was used, the fiberizing processability was good, but the obtained woven fabric was insufficient because of another feature as a texture.

Comparative Example 10 A saponified ethylene-vinyl acetate copolymer used as the component A polymer was tested by using a saponified product having a different saponification degree. A saponification degree of about 80% was used.
Trouble of sticking between single yarns occurred in the drawing process, and phenomena such as severe sticking occurred in the fabric processing process, and a fabric that could be evaluated for feeling could not be obtained.

(Effects of the Invention) As described above, the present invention performs complex spinning of a specific saponified ethylene-vinyl acetate copolymer and a polyester satisfying specific conditions within a range satisfying predetermined conditions.
The object is to provide a soft and excellent texture similar to that of natural fiber which is not found in conventional synthetic fibers and has excellent hydrophilicity, and a good composite fiber free from spots of dyeing.

[Brief description of drawings]

1 to 17 are representative cross-sectional views of the conjugate fiber that is the subject of the present invention.

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Claims (1)

[Claims] 1. An A component comprising an ethylene-vinyl alcohol copolymer having an ethylene copolymerization ratio of 25 to 70 mol%, an alkylene terephthalate unit as a main component, and a group represented by the following general formula (I). Polyalkylene terephthalate-based copolymer having 0.5 to 10 mol% of copolymerized units with respect to terephthalate units, and 100 ppm or more of a metal carboxylic acid of an alkyl metal or an alkaline earth metal in terms of metal based on the polyalkylene terephthalate-based copolymer A composite fiber comprising B component consisting of salt, wherein A component and B component
A composite fiber, wherein the weight ratio of the components is 10:90 to 90:10 and the component A forms at least a part of the fiber surface. (However, A is an aliphatic group or an aromatic group, and M is an alkali metal, alkaline earth metal, or alkylphosphonium group.)