JP2002020933A - Conjugate fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a conjugate fiber good in yarn manufacturing properties, capable of readily extracting and removing an easily soluble component by carrying out an alkali treatment at a low temperature and providing a polytrimethylene terephthalate-based polyester ultrafine fiber having an extremely sharp cross sectional shape. SOLUTION: This conjugate fiber has a cross sectional shape in which a polytrimethylene terephthalate-based polyester is divided into plural parts with a polyethylene terephthalate copolymerized with a 5-sulfoisophthalic acid metal salt in an amount of 1.5-5 mol% based on the whole dicarboxylic acid component and polyethylene glycol in an amount of 2-15 wt.% based on the total weight or a polyester comprising (a) a polyetherester obtained by polycondensing an aromatic dicarboxylic acid with a polyoxyalkylene glycol, (b) a polyethylene glycol having 4,000-60,000 molecular weight and (c) an araklkylsulfonic acid metal salt compound compounded in a specific ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conjugate fiber from which polytrimethylene terephthalate-based polyester ultrafine fibers can be obtained by alkali reduction treatment.

[0002]

2. Description of the Related Art Conventionally, ultrafine fibers having a low single fiber fineness have been widely used in silk-like woven or knitted fabrics, suede-like materials, filters and the like. In addition, nylon 6 as the ultrafine fiber,
Materials using polyamides such as nylon 66 and polyesters such as polyethylene terephthalate and polytrimethylene terephthalate have been proposed. In particular, since a very soft woven or knitted fabric can be obtained from ultrafine fibers made of polytrimethylene terephthalate, a method for producing such fibers by a direct spinning method has been proposed (for example, JP-A-8-232117, Kaihei 11
-100721 publication). However, if a single fiber fineness of 0.1 dtex or less is to be obtained by the direct spinning method as described above, clogging of the nozzle is likely to occur, and it is difficult to produce stably due to poor spinnability. Become.

On the other hand, there has been proposed a method of producing ultrafine fibers by extracting two or more kinds of polymer components having different alkali-solubility into sea-island fibers or fibers arranged in multiple layers and extracting or removing some or all of the easily soluble components. Have been. However,
The conventionally proposed combination of polytrimethylene terephthalate and an alkali-soluble polymer component has extremely poor spinning properties, or partially dissolves into polytrimethylene terephthalate when the alkali is reduced, resulting in the strength of the resulting fiber. However, there is a problem that the object cannot be achieved even if the polytrimethylene terephthalate is left as a modified cross-section fiber to improve the gloss and the feeling.

Polytrimethylene terephthalate has a lower dimensional stability than polyethylene terephthalate. Therefore, there is a problem in that fibers are thermally shrunk when subjected to alkali treatment at a high temperature of 70 ° C. or higher. For this reason, depending on the application, a composite fiber which can easily extract and remove easily alkali-soluble components even when treated at a low temperature of 60 ° C. or less and obtains a polytrimethylene terephthalate ultrafine fiber having a sharp cross-sectional shape as described above is desired. It is rare.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and has as its object the purpose of having good spinning properties and easily extracting and removing easily soluble components even at low temperatures with alkali treatment. An object of the present invention is to provide a conjugate fiber from which a polytrimethylene terephthalate-based polyester ultrafine fiber having a very sharp cross-sectional shape can be obtained.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, have extremely good spinning properties in combination with a polytrimethylene terephthalate-based polyester and have an extremely low alkali weight loss rate even at a low temperature. As a result, the present inventors have found that there is a polyester from which all of the polytrimethylene terephthalate-based polyester can be extracted and removed with almost no damage, leading to the present invention.

That is, a composite fiber having a cross-sectional shape in which a polytrimethylene terephthalate-based polyester component B is divided into a plurality by a polyester component A, wherein the component A is a 5-sulfoisophthalic acid metal salt. 1.5 to 5 mol based on all dicarboxylic acid components of component A
Polyethylene terephthalate obtained by copolymerizing 2 to 15% by weight of polyethylene glycol with respect to the total weight of component A, or (A) a polyetherester obtained by polymerizing aromatic dicarboxylic acid and polyoxyalkylene glycol; (A) Polyethylene glycol having a molecular weight of 4,000 to 60,000, (C) Alkyl or arylsulfonic acid metal salt compound, and the respective compounding amounts W1, W2, W3 (% by weight) based on the total weight of the component A are represented by the following formula (1)
A conjugate fiber characterized by being a polyester blended so as to satisfy (3) is proposed. (1) 4 ≦ W1 + W2 ≦ 20 (2) 0 ≦ W3 ≦ 4 (3) 0.5 ≦ W2 / W1 ≦ 3

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The conjugate fiber of the present invention is a conjugate fiber having a cross-sectional shape in which a polyester component B is divided into a plurality of polyester components A by a polyester component A. For example, FIGS. ) Means a composite fiber having a cross-sectional shape as described in (1).

In the present invention, in the above-mentioned conjugate fiber, the component B is a polytrimethylene terephthalate-based polyester, and the component A is a polyethylene terephthalate obtained by copolymerizing a metal salt of 5-sulfoisophthalic acid and polyethylene glycol at a ratio described below. Or (a) a polyetherester obtained by polymerizing an aromatic dicarboxylic acid and a polyoxyalkylene glycol;
It is important that the polyethylene glycol, (c) alkyl or aryl sulfonic acid metal salt compound having a molecular weight of 00 to 60,000 is any of polyesters blended in the ratio described below. By making such a combination of the component A and the component B, the spinning property is improved, and since the component A is excellent in alkali solubility at a low temperature, the component B is hardly damaged by the alkali weight reduction treatment. Can be obtained even if all of them are extracted and removed, a polytrimethylene terephthalate-based polyester ultrafine fiber having a very sharp cross-sectional shape can be obtained.

The polytrimethylene terephthalate-based polyester as the component B is a polyester having a main repeating unit of trimethylene terephthalate,
Polytrimethylene terephthalate in which the third component is copolymerized within a range that does not impair the object of the present invention, for example, 10 mol% or less, preferably 5 mol% or less based on the acid component, may be used. Preferred copolymerization components include isophthalic acid, adipic acid, sebacic acid, dodecane diacid, dimer acid, sulfoisophthalic acid sodium salt,
Acid components such as sulfoisophthalic acid tetrabutylphosphonium salt, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexane-1,4-dimethanol, 2,2-
Glycol components such as bis {4- (2-hydroxyethoxy) phenyl} propane and polyethylene glycol having a molecular weight of 4000 or less are exemplified.

The above-mentioned polytrimethylene terephthalate-based polyester may contain a matting agent such as titanium oxide, barium sulfate, zinc sulfide or the like, an inorganic substance such as silica, a heat stabilizer, a light stabilizer. Etc. may be included.

The intrinsic viscosity of the above-mentioned polytrimethylene terephthalate-based polyester is preferably 0.6 to 1.3 from the viewpoint that the strength and elongation of the conjugate fiber can be improved.

In the present invention, the other component A constituting the composite fiber is composed of a metal salt of 5-sulfoisophthalic acid in an amount of 1.5 to 5 mol% based on the total dicarboxylic acid component of the component A, and a polyethylene glycol containing the component A. 2 to the total weight of
It can be polyethylene terephthalate copolymerized by 15% by weight.

The copolymerization amount of the above-mentioned metal salt of 5-sulfoisophthalic acid is 1.5 to the total dicarboxylic acid component of component A.
If the amount is less than mol%, the alkali weight loss rate becomes low, and the polytrimethylene terephthalate-based polyester component B is eroded, so that ultrafine fibers having a sharp cross section cannot be obtained. On the other hand, when the copolymerization amount exceeds 5 mol%, the spinnability becomes poor when spinning after being compounded with the polytrimethylene terephthalate-based polyester. As the metal salt,
Preferable examples include a sodium salt, a potassium salt, and a lithium salt. Among them, a sodium salt is particularly preferable.

When the copolymerization amount of polyethylene glycol is less than 2% by weight based on the total weight of component A, the rate of alkali weight loss is reduced, and erosion reaches component B, resulting in a sharp cross section. Can not be obtained. On the other hand, when the copolymerization amount exceeds 15% by weight, not only the spinnability when complexing with the polytrimethylene terephthalate-based polyester of the component B and spinning is deteriorated, but also the fusing at the time of drying the chips and the like. It is more likely to occur and the handling is reduced.

In the present invention, in place of the above polyester, polyester component A may be replaced with (a) a polyetherester obtained by polycondensation of an aromatic dicarboxylic acid and a polyoxyalkylene glycol;
Polyester containing a polyethylene glycol, (c) alkyl or aryl sulfonic acid metal salt compound of No. 00 can be obtained.

Examples of the aromatic dicarboxylic acid component of the compound (A) include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, and 4,4'-diphenyldicarboxylic acid. Examples of the polyoxyalkylene glycol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxyhexylene glycol, and random and block copolymers thereof, with polyethylene glycol being particularly preferred. The molecular weight of the polyoxyalkylene glycol is preferably in the range of 1,000 to 50,000, and more preferably in the range of 3,000 to 20,000, in that the effect of increasing the rate of alkali weight loss can be further enhanced. In addition, a low molecular weight glycol such as ethylene glycol or tetramethylene glycol may be copolymerized within a range that does not impair the object of the present invention.

Next, the compound (a) is necessary to promote the rate of alkali weight loss in addition to improving the spinnability, and the molecular weight is in the range of 4000 to 60000, preferably in the range of 6000 to 50,000. And more preferably in the range of 10,000 to 20,000. When the molecular weight is out of this range, the composite spinnability of the component A and the polytrimethylene terephthalate-based polyester component B becomes unstable.

Further, the metal salt of an alkyl or aryl sulfonic acid of the compound (C) is, for example, dodecylbenzenesulfonic acid, tridecylbenzenesulfonic acid, nonylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, hexadecylsulfonic acid, dodecylsulfonic acid. And alkali metals such as sodium, potassium and lithium such as acids.

In the present invention, the compounds (a) to (d)
(C) the amount W of each component relative to the total weight of component A
1, W2, W3 (% by weight) are further represented by the following formulas (1) to
It must be blended with polyethylene terephthalate to satisfy (3). (1) 4 ≦ W1 + W2 ≦ 20 (2) 0 ≦ W3 ≦ 4 (3) 0.5 ≦ W2 / W1 ≦ 3

When the sum of (a) and (b), W1 + W2, is less than 4% by weight, the effect of promoting alkali weight loss is reduced and the time required for the weight loss treatment is prolonged, so that the resulting polytrimethylene terephthalate-based polyester ultrafine fibers are damaged. Is not preferred. On the other hand, if the above total exceeds 20% by weight, stable spinning properties cannot be obtained when performing composite spinning with the component A and the polyethylene terephthalate-based polyester B.

On the other hand, if the compounding amount W2 of the compound (C) exceeds 4% by weight, the thermal stability of the component A is lowered, and the spinning property is undesirably lowered.

Further, the compounding ratio W of the compounds (A) and (A)
When 2 / W1 is less than 0.5, the spinning property of the conjugate fiber is reduced. On the other hand, when the blending ratio W2 / W1 exceeds 3, the effect of promoting alkali weight loss is reduced, and the weight of the polytrimethylene terephthalate-based polyester component B is easily reduced.

Examples of the polyester in which the above (A) to (C) are blended include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and the like, with polyethylene terephthalate being preferred. Further, the polyester may be a polyester obtained by copolymerizing the third component in a range that does not impair the object of the present invention, for example, 10 mol% or less, preferably 5 mol% or less based on the acid component. Preferred copolymerization components include acid components such as isophthalic acid, adipic acid, sebacic acid, dodecane diacid, dimer acid, ethylene glycol, 1,4-butanediol, 1,6-
Hexanediol, neopentyl glycol, cyclohexane-1,4-dimethanol, 2,2 bis- [4- (2
Glycol components such as [-hydroxyethoxy) phenyl] propane.

The above polyester component A may contain a matting agent, an inorganic substance, an antioxidant, a light stabilizer and the like.

In the present invention, it is desirable that the rate of alkali weight loss of the polyester component A at 40 to 60 ° C. is at least 20 times the rate of alkali weight loss of the polytrimethylene terephthalate-based polyester component B.

Further, when the melt viscosity ratio of the component A and the component B satisfies the following condition, the spinning property can be stabilized, and the lamination of the component A and the component B can be improved, which is more preferable. 0.5 ≦ melt viscosity of component A / melt viscosity of component B ≦ 2.5

In the present invention, in order to impart a soft feeling to the fabric, the component B obtained by reducing the alkali of the component A is used.
The fineness of the single fiber of the ultrafine fiber consisting of is preferably 0.3 dtex or less, more preferably 0.1 dtex or less.

In one single yarn of the conjugate fiber, the number of divisions of the component B divided by the component A is preferably 20 or less from the viewpoint of easy division. The single fiber fineness of the composite fiber is 2
-15 dtex is preferred, and the cross-sectional area ratio of the component B is preferably 50-95%, more preferably 65-9.
0%.

The conjugate fiber of the present invention may be used alone or in combination with other multifilaments to form a mixed fiber. Further, if necessary, it may be used as a false twisted yarn or a spun yarn.

The conjugate fiber of the present invention can be preferably produced, for example, by the following method. Using a conventionally known composite spinneret having the cross-sectional shape shown in FIG. 1, component A and component B are melt-discharged, taken up at 500 to 4500 m / min, and optionally at a temperature of 50 to 120 ° C. ~ 4.
It is stretched 5 times, and if necessary, 100 to 18 times.
By performing heat setting at 0 ° C., the conjugate fiber of the present invention can be produced. In particular, the take-up speed is 2500
By setting it to m / min or more, the heat shrinkage can be reduced, and the effect of the present invention can be remarkable.

Further, the alkali treatment is performed after forming a fiber product such as a woven or knitted fabric or a nonwoven fabric. At this time, the conjugate fiber of the present invention has a good dissolution property of the component A even at a low-temperature alkali weight loss treatment, and at low temperatures, the heat shrinkage of the conjugate fiber is small so that the fiber product is not clogged. Since a gap is formed in the fiber and the fiber is easy to move, a fiber product excellent in drape property can be obtained. Needless to say, by performing alkali treatment at a higher temperature, appropriate shrinkage may be developed to achieve a desired feeling.

[0033]

The present invention will be described below in detail with reference to examples. In the examples, physical properties were measured by the following methods.

Intrinsic viscosity O-chlorophenol was used as a catalyst and measured at 35 ° C. according to a conventional method.

Alkali weight loss rate ratio The polyester components A and B are independently prepared with a diameter of 0.29 mmφ.
Spinning at 3000 m / min using a spinneret of 1.
Stretched 5 times, heat set at 130 ° C, 83dtex
/ 24 filament yarn was obtained. Using these fibers, tubular knitting is made, and 60 g of these tubular knitting samples are prepared.
/ L sodium hydroxide solution at 50 ° C. for 120 minutes, and a weight loss rate ratio was determined from the weight loss rate after the treatment by the following formula. Weight loss rate = weight loss rate of tubular knitting made of polyester component A / weight loss rate of tubular knitting made of polytrimethylene terephthalate-based polyester component B

The spinnability spinning speed 3000 m / min for 24 hours, continuously spinning good what yarn breakage did not occur, somewhat poor what yarn breakage occurs 1-3 times, those generated four or more times It was determined to be bad.

The composite fiber having a cross-sectional shape was subjected to 50 g of sodium hydroxide solution of 60 g / L.
The fiber which was alkali-treated at 35 ° C. and reduced in weight by 35% was cut at arbitrarily selected three points, and an electron micrograph of the cross section of the fiber was taken to evaluate the cross-sectional shape of the ultrafine fiber. If the cross section of the ultrafine fiber is judged to be a circular shape composed of only very sharp island components, the cross section of the ultrafine fiber is slightly increased because the sea component partially remains or is eroded to the island component. Those that were judged to be distorted were judged to be slightly defective, those that were judged to be clearly distorted in the cross section of the ultrafine fiber due to partial elimination of the sea component or erosion to the island component were judged to be defective .

Example 1 Polytrimethylene terephthalate having an intrinsic viscosity of 1.02 (component B) and an intrinsic viscosity of 0.6
4% by weight of a polymer (number-average molecular weight: 150,000) of phthalic acid and polyethylene glycol (PEG) having a molecular weight of 20,000 in polyethylene terephthalate of No. 4;
0) and polyethylene terephthalate (component A) in which 0.4% of dodecylsulfonic acid sodium salt (DSNa) was blended, and the discharge weight ratio was A / B = 3.
The fiber was discharged at a spinning temperature of 272 ° C. using a 36H die with a discharge port diameter of 0.29 mmφ so as to have a fiber cross section as shown in FIG. , And heat-set at 130 ° C. to obtain a 122 dtex / 36 fill multifilament yarn. Table 1 shows the evaluation results. The obtained multifilament yarn was subjected to alkali weight reduction treatment at 50 ° C., but the shrinkage was as small as 4%.

[Examples 2 to 5, Comparative Examples 1 to 4] Example 1
In Example 1, a multifilament yarn was obtained in the same manner as in Example 1 except that the components and the amounts of the components A were variously changed. Table 1 shows the results. In Table 1, DBSNa indicates dodecylbenzenesulfonic acid sodium salt.

[0040]

[Table 1]

Example 6 Polytrimethylene terephthalate having an intrinsic viscosity of 1.02 (component B) and sodium 5-sulfoisophthalate were added in an amount of 2.5 to the total carboxylic acid component.
Using polyethylene terephthalate (component A) obtained by copolymerizing polyethylene glycol having a molecular weight of 4000 and a molecular weight of 4000 so as to be 10% by weight of the total polymer, the discharge weight ratio was set to A / B = 35/65, and FIG. )), The fiber is discharged at a spinning temperature of 272 ° C. using a 36H die with a discharge diameter of 0.29 mmφ, and a spinning speed of 3000.
m / min, stretched 1.4 times at 60 ° C.
Heat setting was performed at ℃ to obtain a 122 dtex / 36fil multifilament yarn. Table 2 shows the evaluation results. The obtained multifilament yarn was subjected to alkali weight reduction treatment at 50 ° C., but the shrinkage was as small as 4%.

Examples 7 and 8, Comparative Examples 5 and 6
In Example 5, a multifilament yarn was obtained in the same manner as in Example 5, except that the copolymerization component and the amount of copolymerization of the component A were variously changed. Table 2 shows the results.

[0043]

[Table 2]

Comparative Example 7 A polytrimethylene terephthalate (component B) having an intrinsic viscosity of 1.02 was spun at a spinning temperature of 275 ° C.
Attempted spinning at a spinning speed of 3000 m / min with a spout of 0.1 mmφ at a discharge rate of 5 g / min and a spinning speed of 3000 m / min.

[0045]

According to the present invention, the polytrimethylene terephthalate-based polyester having a sharp cross-sectional shape has a very good spinning property and easily extracts and removes easily soluble components by low-temperature alkali treatment. A composite fiber from which a fiber can be obtained can be provided. For this reason, it is possible to suppress the heat shrinkage at the time of processing the above-mentioned ultrafine fibers at the time of alkali weight reduction, and to obtain fibers excellent in gloss etc. due to the deformed cross-sectional effect. This provides an effect that a fiber product having a glossiness and a feeling that cannot be obtained with trimethylene terephthalate-based ultrafine fibers can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a conjugate fiber according to the present invention.

[Explanation of symbols]

A Polyester component A B Polytrimethylene terephthalate-based polyester component B

Continued on the front page (72) Inventor Mitsuo Matsumoto 77 Kitayoshida-cho, Matsuyama-shi, Ehime Prefecture Teijin Limited Matsuyama Plant F-term (reference) BA34 BD15 BD20 CA08 CA12 CA13 CA16 CA51 DD01 DD11 DD18 EE06 EE15

Claims (1)

[Claims] 1. A composite fiber having a cross-sectional shape in which a polytrimethylene terephthalate-based polyester component B is divided into a plurality by a polyester component A, wherein the component A is a 5-sulfoisophthalic acid metal salt. 1.5 to 5 mol% based on the total dicarboxylic acid component of the component A and polyethylene glycol are 2 to 2 based on the total weight of the component A.
Polyethylene terephthalate copolymerized by 15% by weight, or (a) polyetherester obtained by polymerizing aromatic dicarboxylic acid and polyoxyalkylene glycol; (a) polyethylene glycol having a molecular weight of 4000 to 60,000; The compounding amounts W1, W2, W3 (% by weight) of the arylsulfonic acid metal salt compound with respect to the total weight of the component A are represented by the following formulas (1) to (3).
A composite fiber characterized by being a polyester blended so as to satisfy the following. (1) 4 ≦ W1 + W2 ≦ 20 (2) 0 ≦ W3 ≦ 4 (3) 0.5 ≦ W2 / W1 ≦ 3