JPH08109521A - Splittable type polyester conjugated fiber - Google Patents

Abstract

PURPOSE: To obtain the subject splittable type conjugated fiber, good in splittability by treatment with hot water, capable of readily providing ultrafine polyethylene terephthalate-based fibers and hardly causing yarn breakage in spinning by specifying a hot water-soluble polymer component. CONSTITUTION: This conjugated fiber is smoothly obtained by using (A) a blend of 85-98wt.% copolymerized polyethylene terephthalate containing 5-15mol% isophthalic acid component having a metallic sulfonate group and 5-40mol% isophthalic acid component with 2-15wt.% polyether ester of a dicarboxylic acid component with a polyethylene glycol component as a hot water-soluble polymer component and (B) a polyester containing ethylene terephthalate unit as a main recurring unit. The component (B) is divided into plural parts with the hot water-soluble polymer component (A) and the conjugated fiber has a fiber cross-sectional shape in which the polyester component (B) is divided into plural parts with the hot water-soluble polymer component (A).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a splittable polyester conjugate fiber in which one component has a fiber cross-sectional shape divided into a plurality of parts by the other component. More specifically, it is treated with hot water. Thus, the present invention relates to a splittable polyester conjugate fiber which can stably and efficiently obtain a polyester fiber having an ultrafine fineness and which is excellent in process stability during spinning.

[0002]

2. Description of the Related Art Polyethylene terephthalate fibers are
It has excellent properties such as high melting point, high strength, high Young's modulus, good electrical properties, and chemical resistance. By using ultrafine fibers, it can be used for silk-like woven and knitted fabrics, sports clothing, filters, and various other clothing. , It is expected to expand into the industrial field.

As a method for obtaining polyethylene terephthalate type ultrafine fibers, a method for directly spinning ultrafine fibers and a splittable conjugate fiber having a fiber cross-sectional shape in which a polyethylene terephthalate component is divided into a plurality of components by a component capable of being decomposed and removed. Therefore, there is a method to remove the components that can be decomposed and removed to make it ultrafine, but especially the latter can be made finer after processing, so it can be processed with an ordinary thickness, and high-order processing and handling are easy. Has the advantage that

Removing degradable components from the composite fiber,
As a method for obtaining ultrafine fibers, there is a method in which the modified polyester component is decomposed and removed by alkali reduction treatment from a split-type polyester composite fiber composed of a polyethylene terephthalate component and a modified polyester component having an alkali hydrolysis rate higher than that of the polyethylene terephthalate component.
For example, in Japanese Examined Patent Publication No. 60-7723, polyethylene terephthalate copolymerized with sodium sulfoisophthalic acid is used as a component that can be removed by alkaline hydrolysis.

However, in such a method, when the alkali weight reduction treatment is carried out until the polyethylene terephthalate component is completely divided, the ultrafine fibers obtained are too thin because the polyethylene terephthalate component side is affected by the alkali weight reduction treatment. Problems such as deterioration of mechanical properties are likely to occur.

In order to improve this, a method is proposed in which a hot water-soluble modified polyester component is used and the modified polyester component is dissolved and removed from the splittable polyester conjugate fiber composed of this and a polyethylene terephthalate component by hot water treatment. Has been done. For example, JP-A-5-2477
In Japanese Patent Laid-Open No. 25, the polyethylene terephthalate obtained by copolymerizing sodium sulfoisophthalic acid and isophthalic acid is used as the hot water-soluble component. However,
The conventional splittable polyester conjugate fiber using a hot water-soluble component has a problem that the splittability by hot water treatment is not sufficient.

[0007]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and provides good splittability of composite fibers by hot water treatment,
It is an object of the present invention to provide a splittable polyester conjugate fiber which can easily obtain polyethylene terephthalate ultrafine fibers and has excellent process stability during spinning.

[0008]

Means for Solving the Problems The inventors of the present invention have made extensive studies to achieve the above-mentioned object, and as a result, as a hot water-soluble polymer, a copolymer containing an isophthalic acid component having a sulfonate metal base and an isophthalic acid component. By using a blend polymer of polyethylene terephthalate and a specific polyether ester, it was found that the splittability of the composite fiber by hot water treatment was improved, and the process stability during spinning was also improved, and the present invention was reached. did.

That is, according to the present invention, the component A and the component B are
Wherein the component B is a conjugate fiber having a fiber cross-sectional shape divided into a plurality of parts by the component A,
Is an isophthalic acid component having a sulfonic acid metal base 5
85-98% by weight of copolymerized polyethylene terephthalate containing 15 mol% and an isophthalic acid component of 5-40 mol%
And 2 to 15% by weight of a polyether ester composed of a dicarboxylic acid component and a polyethylene glycol component, which is a hot water-soluble polymer, and the component B is a polyester having an ethylene terephthalate unit as a main repeating unit. A splittable polyester conjugate fiber is provided.

In the present invention, as the component A for dividing the component B into a plurality of parts, 5 to 15 mol% of the isophthalic acid component having a metal sulfonate group and 5 to 4 of the isophthalic acid component are included.
Copolymerized polyethylene terephthalate 85 containing 0 mol%
It is necessary to use a hot water-soluble polymer obtained by blending ˜98% by weight and 2 to 15% by weight of a polyether ester composed of a dicarboxylic acid component and a polyethylene glycol component.

The isophthalic acid component having the sulfonic acid metal base of the copolymerized polyethylene terephthalate is
Examples include 5-lithium sulfoisophthalic acid, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, and the like.

The copolymerized polyethylene terephthalate contains an isophthalic acid component containing a metal sulfonate group.
It is necessary that the content is 5 to 15 mol%, more preferably 7 to 13%. When it is less than 5 mol%, sufficient hot water solubility cannot be obtained, and when it is more than 15 mol%, the number of yarn breakages at the time of spinning of the composite fiber tends to increase and the process stability tends to be deteriorated. Is.

The copolymerized polyethylene terephthalate must contain an isophthalic acid component in an amount of 5 to 40 mol%, more preferably 8 to 15%.
If it is less than 5 mol%, sufficient hot water solubility cannot be obtained,
When it is more than 40 mol%, the number of yarn breakages at the time of spinning the composite fiber tends to increase and the process stability tends to be deteriorated, which is not suitable.

Further, the polyether ester compounded in the component A comprises a dicarboxylic acid component and a polyethylene glycol component, and preferably used dicarboxylic acid components are phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid and diphenyldicarboxylic acid. Aromatic dicarboxylic acid such as acid and diphenoxyethanedicarboxylic acid,
Examples thereof include aliphatic and alicyclic dicarboxylic acids such as adipic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid. The polyethylene glycol has a molecular weight of 1,000 to 50,000, and preferably 3,000 to 20,000, since the effect of increasing the rate of hot water dissolution decreases if the molecular weight is too small or too large. .

The molecular weight of the polyether ester composed of both components is preferably 10,000 to 150,000, and 4 to 50 molecules of the dicarboxylic acid component are used per molecule of the polyether ester. It is desirable that the

In order to produce such a polyether ester, a conventionally known method may be employed as it is. For example, it can be easily obtained by reacting the acid anhydride or acid chloride of the dicarboxylic acid with polyethylene glycol. You can At this time, a small amount of a low molecular weight glycol such as ethylene glycol or tetramethylene glycol may be copolymerized within a range not impairing the object of the present invention.

In the present invention, the hot water-soluble polymer used as the component A is 85 to 98% by weight of the above-mentioned copolymerized polyethylene terephthalate, and the above polyether ester 2
It should be a blend of .about.15% by weight. When the content of the copolymerized polyethylene terephthalate exceeds 98% by weight and the content of the polyether ester is less than 2% by weight, sufficient hot water solubility cannot be obtained,
When the content of the copolymerized polyethylene terephthalate is less than 85% by weight and the content of the polyether ester is more than 15% by weight, the number of yarn breakages at the time of spinning the composite fiber is increased and the process stability tends to be deteriorated. It is inappropriate because there is. More preferably, the content of the copolymerized polyethylene terephthalate is 90 to 95% by weight, and the content of the polyether ester is 5 to 10% by weight.

In the present invention, the hot water-soluble polymer used as the component A can be produced by any method, for example, dimethyl terephthalate, dimethyl isophthalate, sodium sulfoisophthalic acid and ethylene glycol, and the above copolymerized polyethylene. At any time during the reaction for synthesizing terephthalate, a method of adding the polyether ester, a method of melt-mixing the copolymerized polyethylene terephthalate and the polyether ester that have been preliminarily synthesized using an extruder, etc. Can be manufactured by.

On the other hand, in the present invention, the polyester used as the component B is a polyethylene terephthalate type polyester having an ethylene terephthalate unit as a main repeating unit, and unless a hot water solubility is exhibited, a part of the terephthalic acid component is It may be a polyester in which the bifunctional carboxylic acid component of is replaced, or a polyester in which a part of the ethylene glycol component is replaced with another diol component. Particularly, polyethylene terephthalate is preferably used.

Examples of the bifunctional carboxylic acid other than terephthalic acid used here include isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, adipic acid, sebacic acid,
Examples thereof include aromatic, aliphatic, and alicyclic bifunctional carboxylic acids such as 1,4-cyclohexanedicarboxylic acid. Examples of diol compounds other than ethylene glycol include aliphatic, alicyclic and aromatic compounds such as tetramethylene glycol, hexamethylene glycol, cyclohexane-1,4-dimethanol, neopentyl glycol, bisphenol A and bisphenol S. The diol compound can be mentioned.

The polyester can be synthesized by any method. For example, when polyethylene terephthalate is described, usually, terephthalic acid and ethylene glycol are directly esterified, or a lower alkyl ester of terephthalic acid such as dimethyl terephthalate and ethylene glycol are transesterified, or terephthalic acid is used. The first step reaction of reacting an acid with ethylene oxide to produce a glycol ester of terephthalic acid and / or a low polymer thereof and heating the reaction product of the first step under reduced pressure to obtain the desired product. It is produced by a second stage reaction in which a polycondensation reaction is performed until the degree of polymerization reaches.

In the present invention, the polyethylene terephthalate polyester used as the component B is a matting agent such as titanium dioxide, an anti-coloring agent, an antioxidant, an anionic, cationic or nonionic surface active agent, It may contain an antistatic agent, an easy dyeing agent, an inorganic fine particle coloring agent, a flame retardant and the like.

The composite form of the hot water-soluble component A and the polyethylene terephthalate polyester component B and the cross-sectional shape of each component are arbitrary as long as the component B is divided into a plurality of components by the component A. Some examples Figure 1
(A) to (i) are shown.

In FIG. 1, A is a hot water-soluble component (component A) and B is a polyethylene terephthalate polyester component (component B). (A) to (c) are splittable conjugate fibers in which the component B is split into 16 by the component A. (D) is a sea-island type splittable conjugate fiber in which the component A is the sea and the component B is an island.
Is divided into (E) and (f) are split type conjugate fibers having a flat cross-sectional shape, and (g) to (i) are the outer peripheral portions of (a) to (c) coated with the component A, respectively.

Such a splittable conjugate fiber is made into a fabric and then subjected to hot water treatment to dissolve the component A and the component B.
Is divided into ultrafine fibers and a space can be provided between the fibers, so that the fabric can be bulky and exhibit a soft texture.

In the splittable polyester conjugate fiber composed of the component A and the component B, the more the component A is, the easier the splitting by the hot water treatment is. Is deteriorated, the handleability in the subsequent step is deteriorated, and moreover, the amount of components to be dissolved and removed is increased, which is also disadvantageous in terms of cost. From this viewpoint, the weight ratio of component A: component B is preferably 80:20 to 2:98, and more preferably 60:40 to 5:95.

In the splittable polyester conjugate fiber of the present invention, the ultrafine fiber constitutional unit comprising the component B is 0.3 denier or less, and the number of the constitutional unit is 16 or more, particularly 24.
When the above is satisfied, the effect becomes remarkable, which is preferable.

The splittable polyester conjugate fiber of the present invention described above can be produced by a conventional method using a conventionally known composite spinneret and composite spinning apparatus. For example,
Method of melt-spinning at a drawing speed of 500 to 2,500 m / min, stretching and heat treatment, melt spinning at a drawing speed of 1,500 to 5,000 m / min, and stretching and false twisting simultaneously or sequentially. For example, a method of performing the melt spinning at a high speed of 5,000 m / min or more and a method of omitting the stretching step can be adopted depending on the application. Further, the obtained ultrafine fibers or a fabric produced from the ultrafine fibers may be heat-treated at a temperature of 100 ° C. or higher to improve the stability of the structure, and if necessary, a relaxation heat treatment or the like may be used in combination. You may.

[0029]

The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. In addition, the part in an Example shows a weight part. The spinning tone is ○, when the yarn breakage hardly occurs during spinning and is stable,
Occasionally, yarn breakage occurred, but when it was generally stable, it was marked with Δ, and when it was unstable due to frequent occurrence of yarn breakage, it was marked with x. The hot water solubility was evaluated as ◯ when the composite fiber was treated with hot water and had good splittability, Δ when the splittability was somewhat inferior but practically no problem, and x when the splittability was poor.

[Examples 1 to 4, Comparative Examples 1 and 2] 80 parts of dimethyl terephthalate, 10 parts of dimethyl isophthalate, 5
-Prepare 15 parts of sodium dimethyl sulfoisophthalate, 63 parts of ethylene glycol and 0.06 parts of calcium acetate in a transesterification reactor and raise the temperature from 140 ° C to 220 ° C over 3 hours to remove generated methanol out of the system. The transesterification reaction was carried out while distilling off. After stirring at 220 ° C. for 20 minutes, 0.06 parts of orthophosphoric acid was added as a stabilizer, and at the same time, the temperature rising of the excess ethylene glycol was started. After 10 minutes, 0.04 part of antimony trioxide was added as a polymerization catalyst. When the internal temperature reached 240 ° C, the purging of ethylene glycol was terminated, and the reaction product was transferred to the polymerization reactor. Then, after raising the temperature to reach the internal temperature of 260 ° C., the temperature is increased from 760 mmHg to 1 mm over 1 hour.
Hg, and at the same time, raise the internal temperature to 28 over 1 hour and 30 minutes.
The temperature was raised to 0 ° C. Polymerization was carried out at a polymerization temperature of 280 ° C. under a reduced pressure of 1 mmHg or less for 1 hour and 30 minutes, and then isophthalic acid and polyethylene glycol (molecular weight: 10,000
0) and having a degree of polymerization of 10 were added so as to have a compounding ratio shown in Table 1, and the polymerization reaction was terminated when the polymerization was further performed for 30 minutes, and chips were formed according to a conventional method.

A hot water-soluble polymer obtained by blending the copolymerized polyester and polyether ester is used as the component A, while polyethylene terephthalate having an intrinsic viscosity of 0.64 is used as the polyester of the component B, and a composite is prepared according to a conventional method. The hollow annular multilayer laminated composite fiber shown in FIG. 1 (C) after spinning and drawing (however, the component A and the component B are
8 layers each, composite ratio 50/50, 75 denier / 20
Filament) was obtained. The process stability during spinning (spinning tone) was as shown in Table 1.

The obtained composite fiber was made into a plain weave and the temperature was 10
The treatment was carried out with hot water at 0 ° C. The splittability of the composite fibers constituting the woven fabric (hot water solubility of component B) was as shown in Table 1.

[0033]

[Table 1]

When the copolymer of the hot water-soluble polymer used as the component A is 85 to 98% by weight of the polyethylene terephthalate and 2 to 15% by weight of the polyether ester (Examples 1 to 4), the spinning tone and the hot water are And the copolymerization polyethylene terephthalate is 90 to 95% by weight, and the polyether ester is 5 to 10% by weight.
Favorable results were obtained when it was wt% (Examples 2 and 3).

On the other hand, when the content of the copolymerized polyethylene terephthalate is less than 85% by weight and the content of the polyether ester is more than 15% by weight (Comparative Example 1), the breakage at the time of spinning the composite fiber is observed. When the number of yarns increases and the spinning condition deteriorates, the content of copolymerized polyethylene terephthalate exceeds 98% by weight, and the content of the polyether ester is less than 2% by weight (Comparative Example 2), sufficient heat is applied. No separability with water was obtained.

[Examples 5 to 10 and Comparative Examples 3 to 6] In Example 2, the amounts of terephthalic acid, 5-sodium sulfoisophthalic acid and isophthalic acid components of the copolymerized polyethylene terephthalate (component A) are shown in Table 2. A hollow ring-shaped multilayer laminated composite fiber was prepared in the same manner as in Example 2 except for the above changes.

The process stability during spinning (spinning tone) and the splittability of the obtained composite fiber (hot water solubility of component B) are shown in Table 2.
It was as shown in.

[0038]

[Table 2]

The amount of 5-sodium sulfoisophthalic acid component and the amount of isophthalic acid component contained in the copolymerized polyethylene terephthalate (component A) are 5 to 15 mol% and 5 to 4, respectively.
When it is 0 mol% (Examples 5 to 10), the spinning tone is
When the amount of 5-sodium sulfoisophthalic acid component is 7 to 13 mol% (Examples 5 and 6) and the amount of isophthalic acid component is 8 to 15 mol%, the resolvability by hot water is good. The preferred results were obtained in Examples 8, 9).

On the other hand, when the amount of the 5-sodium sulfoisophthalic acid component is less than 5 mol% (Comparative Example 3) and the amount of the isophthalic acid component is less than 5 mol% (Comparative Example 5), it is sufficient. When the amount of 5-sodium sulfoisophthalic acid component exceeds 15 mol% (comparative example 4) and the amount of isophthalic acid component exceeds 40 mol% (comparative example 6). The yarn breakage during spinning increased, and the spinning condition deteriorated.

[Example 11] In Example 2, the component A was used.
In place of the polyether ester composed of isophthalic acid and polyethylene glycol (molecular weight 10,000) used for the hot water-soluble polymer of, phthalic acid and polyethylene glycol (molecular weight 20,000) were used, and the degree of polymerization was 5
In addition to using the polyether ester which is, the sea-island type composite fiber spinning device is used.
Similarly to the above, the sea-island type composite fiber (component A / component B composite ratio = 50/50, 75 denier / 2) shown in FIG. 1 (d).
0 filaments) was obtained.

The fiber breakage during spinning hardly occurred, the stability of the spinning process was good, the splittability of the conjugate fiber by hot water treatment was also good, and the ultrafine fibers of component B could be easily obtained.

[Example 12] In Example 2, the component B was used.
Polyethylene terephthalate obtained by copolymerizing 3 mol% of isophthalic acid (intrinsic viscosity 0.64) was used in place of the polyethylene terephthalate of Example 1, and otherwise the same procedure as in Example 2 was carried out to obtain a hollow annular multilayer laminated composite fiber. Created.

Fracture during spinning hardly occurred, the stability of the spinning process was good, the splitting property of the composite fiber by hot water treatment was also good, and the ultrafine fiber of component B could be easily obtained.

[0045]

According to the present invention, by using a blended polymer of copolymerized polyethylene terephthalate having a specific composition and a specific polyether ester as the hot water-soluble polymer, there is no breakage, The splittable polyester conjugate fiber can be spun under good spinning process stability, and the ultrafine fiber can be easily obtained by subjecting the obtained conjugate fiber to hot water treatment.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view showing an example of a splittable polyester conjugate fiber of the present invention.

[Explanation of symbols]

 A component A B component B

Claims (1)

[Claims] 1. A composition comprising a component A and a component B, wherein the component B
Is a conjugate fiber having a fiber cross-sectional shape divided into a plurality of parts by the component A, wherein the component A is 5 to 15 mol% of isophthalic acid component and 5 to 40 mol of isophthalic acid component having a metal sulfonate group. % Copolymerized polyethylene terephthalate containing 85% by weight and a polyether ester consisting of a dicarboxylic acid component and a polyethylene glycol component 2 to 15% by weight are hot water-soluble polymers in which the component B is ethylene. A splittable polyester conjugate fiber, which is a polyester having a terephthalate unit as a main repeating unit.