JP2001181932A - Polyester-based side-by-side conjugate fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester-based side-by-side conjugate fiber suitable for textiles capable of obtaining microfiber from which fabrics having both soft feeling and drape with massive feeling can be produced. SOLUTION: This conjugate fiber has a cross section in which a polyester B as a hardly alkali-soluble component is divided by a polyester A as an easily alkali-soluble component. The component of the polyester B contains 0.8-8 wt.% ceramic microparticles having 0.3-2.0 μm mean particle diameter and >=3.5 g/cm3 density and the split fiber split by alkali weight reduction has >=1.375 g/cm3 density.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dividing a hardly eluting component into a plurality of portions by an alkali easily eluting component, which is suitable for obtaining an ultrafine fiber having both a soft texture and a heavy drape. And a polyester-based splittable conjugate fiber.

[0002]

2. Description of the Related Art A splittable conjugate fiber in which a hardly-eluting component is divided into a plurality of components by a readily-eluting component in a fiber cross section is spun using an alkali with an easily-eluting component and a hardly-eluting component. A method for obtaining ultrafine fibers by removing easily eluting components with a solvent is widely used.

In particular, the easily-eluting component and the hardly-eluting component are composed of mutually compatible polyester-based components, and the rate of hydrolysis of the easily-eluting component by alkali is increased by making it faster than that of the hardly-eluting component. Fibers have been widely used so far due to the following advantages. (1) Alkaline weight reduction processing of polyester fiber is common, and the chemicals and dissolution apparatus are not special, and are safe and inexpensive. (2) Before elution treatment such as spinning, drawing, weaving, etc.,
There is no trouble such as peeling between the easily-eluting component and the hardly-eluting component, and stable processing can be performed. (3) It has sufficient practical strength in the knitting and weaving process and the woven and knitted fabric.

As these splittable conjugate fibers, for example, JP-A-62-78213 and JP-A-1-260018 disclose polyethylene terephthalate (PET) as a hardly eluting component and sulfone as an easily eluting component. Fibers using a polyester obtained by copolymerizing a specific amount of an aromatic dicarboxylic acid component having an acid base and containing a specific amount of a polyalkylene glycol are known. Ultrafine fibers can be produced from these splittable conjugate fibers, and although a fabric having a soft feeling peculiar to the ultrafine fibers can be obtained, the fabric lacks firmness and stiffness, and there is a problem that drape property is particularly poor.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above problems and provides a polyester suitable for a woven or knitted fabric capable of obtaining an ultrafine fiber which is a cloth having both a soft texture and a heavy drape. An object of the present invention is to provide a system splittable conjugate fiber.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention relates to a conjugate fiber having a cross-sectional shape in which polyester B, which is a component hardly eluting with alkali, is divided into a plurality of portions by polyester A, which is a component easily eluting with alkali, wherein the average particle diameter in the component of polyester B is 0.3. ~
2.0μm, ceramic particles with a density of 3.5g / cm ³ or more
A polyester-based splittable conjugate fiber containing 0.8 to 8.0% by weight and having a density of 1.375 g / cm ³ or more after splitting by alkali reduction. Here, the average particle size of the ceramics referred to in the present invention is the average particle size of the aggregate of particles observed in the fiber (μ).
m).

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail. The conjugate fiber of the present invention has a cross-sectional shape in which, in the cross section of the fiber, polyester B, which is a component hardly eluting with alkali, is divided into a plurality by polyester A, which is a component easily eluting with alkali. FIGS. 1A to 1F are schematic cross-sectional views showing specific examples of such a conjugate fiber.
In the figure, C is a hollow portion. As shown in FIG. 1, polyester B, which is a component that is hardly eluted, is divided into a plurality of polyesters by polyester A, which is an easily eluting component, and each of the divided polyesters A becomes ultrafine fibers of 0.33 dtex or less after division. Preferably, there is.

In the present invention, it is preferable to use a polyester mainly composed of an ethylene terephthalate unit as the polyester A, which is an easily alkali-eluting component, from the viewpoint of alkali weight loss and spinnability. In order to increase the alkali weight loss rate, it is preferable to copolymerize an aromatic dicarboxylic acid component having a sulfonic acid group with the dicarboxylic acid component, and the amount is 2 to 20% by weight. Examples of the aromatic dicarboxylic acid component containing a sulfonic acid group include 5-sodium sulfoisophthalic acid, 5-sodium sulfoterephthalic acid, 5-potassium sulfoisophthalic acid, 5-potassium sulfoterephthalic acid, and 5-lithium sulfoisophthalic acid. No. Particularly, 5-sodium sulfoisophthalic acid is preferred. The copolymerization amount is appropriately selected depending on the difference in the alkali weight reduction rate between the polyester A and the polyester B, but is preferably in the range of 0.5 to 3.0 mol%. It is preferable in terms of surface and the like. Further, the average molecular weight is from 1,000 to 10,000.
The one containing 2 to 15% by weight of the polyalkylene glycol is preferred. Polyalkylene glycol dissolves in polyester A as soon as possible by dissolving it with alkali, thereby breaking the molecular chain of polyester A, and also acts to increase the surface area by generating voids on the surface, thereby increasing the dissolution rate. It is.

Next, the polyester B, which is a component hardly eluting with alkali, is not particularly limited as long as it has a lower alkali weight loss rate than that of polyester A, but PET or polybutylene terephthalate is preferable, and a small amount of May be contained. As the copolymerization component, 5-sodium sulfoisophthalic acid, isophthalic acid, phthalic anhydride, aromatic dicarboxylic acid components such as naphthalenedicarboxylic acid, adipic acid, aliphatic dicarboxylic acid components such as sebacic acid, ethylene glycol, diethylene glycol,
Glycol glycol components such as 1,4-butanediol, 1,4-cyclohexanedimethanol, alkylene oxide adducts of bisphenol A and alkylene oxide adducts of bisphenol S, and hydroxycarboxylic acids such as 4-hydroxycarboxylic acid and ε-caprolactone And the like. Further, the polymer, antistatic, flame retardant, light resistance, additives for the purpose of imparting functionality such as antifouling,
Matting agents, pigments and the like may be blended.

The rate of weight loss of the polyester A, which is an easily alkali-elutable component, is preferably at least 10 times faster than the rate of weight loss of the polyester B, which is a component which is hardly alkali-elutable. If the ratio of the alkali weight reduction rate of the polyester A and the polyester B is less than 10, the splitting fiber may become defective when splitting by the alkali treatment, or the alkali weight loss processing time becomes longer, so that the fiber after the splitting has a practical strength or less. It is not preferable because it is easy.

In the present invention, the polyester B divided by the polyester A has an average particle size in the components of 0.3 to 2.0.
0.8 μm, ceramic fine particles with a density of 3.5 g / cm ³ or more
It is important that it be contained at ~ 8.0% by weight. By containing these fine particles, the feeling of weight of the fiber is increased, and at the same time, the fine particles are partially exposed on the fiber surface, thereby lowering the surface frictional resistance.
When made into a fabric, it is possible to develop a good drape feeling irrespective of the ultrafine fibers. The ceramic fine particles used herein refer to fine particles of an inorganic material obtained through steps such as molding and firing, and titanium oxide, inorganic oxide fine particles such as silicon oxide are typical, and the fine particles at the polyester interface Those having a small surface tension and hardly condensing during melting are preferable in operation.

The ceramic fine particles have an average particle size of 0.3 to
2.0 .mu.m, preferably should be in the range of 0.3 to 1.0 micron m. By partially exposing the ceramic fine particles having an average particle size in this range to the fiber surface, it is possible to improve the slip of the fiber surface.If the average particle size is smaller than 0.3 μm, the fiber surface is modified. When the particle size is larger than 2.0 μm, the particles are locally exposed to a large extent, increasing the frictional resistance. In extreme cases, the particles are localized, causing yarn breakage due to biased stress during spinning. Operational problems such as fraying and fuzzing during stretching occur.

The density of the ceramic fine particles is 3.5 g / c.
m ³ or more, preferably 3.8 g / cm ³ or more, 3.
Poor effect of increasing the low and the density of fibers than 5 g / cm ^3, if a large amount to be included in order to increase the density, yarn breakage may occur during spinning, stretching, etc. fluff occurs during processing, runnability There is a problem.

Further, the content of the ceramic fine particles should be in the range of 0.8 to 8.0% by weight, preferably 1.0 to 5.0% by weight of the polyester B component used as the hardly-eluting component. Is less than 0.8% by weight, the effect of imparting a feeling of weight and reducing surface friction is poor.
If the content is higher than 8.0% by weight, there is a problem in operation that yarn breakage, fluff and the like occur. The ceramic fine particles can be added at the time of melting during the polymerization or spinning of the polyester, but is preferably added during the polymerization in consideration of preventing aggregation and more uniformly dispersing.

[0015]

The polyester splittable conjugate fiber of the present invention has an average particle size of 0.3 to 2.0 μm and a density in the component of polyester B, which is a component hardly soluble in alkali, divided by polyester A, which is a component easily soluble in alkali. containing 3.5 g / cm ³ or more ceramic fine particles, since the fiber density after being divided by the caustic is 1.375 g / cm ³ or more, ultrafine fiber peculiar softness and weight to the fabric composed of the fiber It is possible to provide a drape with a feeling.

[0016]

Next, the present invention will be described in detail with reference to examples. Note that the measurement and evaluation of various characteristic values in the examples are as follows.
The procedure was as follows. (A) Weight loss of alkali After knitting a conjugate fiber and scouring it at 60 ° C for 20 minutes, a bath ratio of 1:50 and a 10% by weight aqueous solution of sodium hydroxide at a processing temperature of 70 ° C and a weight loss of 25% were obtained. Processing was performed. (B) Fiber density Unwind the knitted fabric after reducing the alkali of (a) and make the fiber length 5m
m was measured by immersing it in a density gradient tube using a mixed solution of carbon tetrachloride and ligroin. (C) Softness and Drapability A drawn yarn of 56 dtex / 24f was used as the warp, and a plain weave was woven using the evaluation yarn as the weft, and a 25% alkali reduction treatment was performed. Using the cloth, sensory evaluation by ten panelists was performed based on the average value of the evaluation values in ten steps, and the following four steps were determined. ◎ and ○ were regarded as passing points.

Examples 1 to 5, Comparative Examples 1 to 4 As polyester A, 0.5 mol% of 5-sodium sulfoisophthalic acid (SIP-Na) and 3.0 weight% of polyethylene glycol (PEG) having an average molecular weight of 8000 were used. % Copolymerized PET having an intrinsic viscosity of 0.72, and polyester B added with titanium dioxide fine particles having a density and an average particle diameter shown in Table 1 at the time of polymerization, and a spinning temperature of 290 ° C.
Polyester A / B composite weight ratio 20/80, discharge amount 3
Spinning at 1 g / min into the cross-sectional shape shown in Table 1, winding at a speed of 2800 m / min while cooling and applying an oil agent,
122dtex) / 48f highly oriented undrawn yarn (POY)
Was collected.

Next, this POY is stretched through a heating roller at 70 ° C. so that the target elongation becomes 30 ± 2%, and further heat-treated on a heat plate at 130 ° C.
(tex) / 48f was obtained.

Comparative Example 5 A drawn yarn was obtained under the same conditions as in Example 1 except that the added fine particles of polyester B were changed to talc. Example 1
Table 1 also shows the fiber density and the evaluation results of the woven fabric after splitting by alkali weight reduction obtained in Comparative Example 1 and Comparative Examples 1 to 5.

[0020]

[Table 1]

As is clear from Table 1, the fabrics obtained in Examples 1 to 5 had a soft feeling and a good drape property.

On the other hand, in Comparative Example 1, since the content of the titanium dioxide fine particles was small, a woven fabric having low drape property and inferior firmness was obtained as in the case of using ordinary fine yarn. Also,
In Comparative Example 2 in which the content of fine particles was increased, fluffing frequently occurred during stretching, and a sample could not be collected.
In Comparative Example 3, the average particle size of the added fine particles was small, the effect of modifying the fiber surface was poor, and a woven fabric lacking in drape property was obtained. Next, in Comparative Example 4, since the average particle diameter of the added fine particles was large, the number of cut yarns during spinning was large, and a sample could not be collected. Further, in Comparative Example 5, the fine particles were changed to talc to lower the density of the fine particles, so that a woven fabric lacking in drape property was obtained.

[0023]

The polyester-based splittable conjugate fiber of the present invention can be divided into ultrafine fibers by subjecting it to alkali weight reduction, and after the weight loss, has both a soft texture and a heavy drape. A knit can be obtained.

[Brief description of the drawings]

FIGS. 1 (a) to 1 (f) are schematic views showing the cross-sectional shapes of the polyester-based splittable conjugate fibers of the present invention.

[Explanation of symbols]

 A Polyester A of easy-eluting component B Polyester B C of low-eluting component Hollow portion

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4L031 AA18 AB08 BA10 CA01 DA06 4L035 BB33 BB40 BB59 BB89 CC03 CC20 EE20 JJ05 KK01 KK10 4L041 AA08 AA15 AA19 AA20 AA25 BA03 BA04 BA05 BA09 BA13 BA17 BA42 BC20 DD06 DD21 EE06 EE15 EE20

Claims (1)

[Claims] 1. Polyester B as a component hardly eluting with alkali
Is a composite fiber having a cross-sectional shape divided into a plurality of pieces by polyester A, which is an alkali-eluting component, having a mean particle size of 0.3 to 2.0 μm and a density of 3.5 g / cm ³ or more in the component of polyester B. Contains 0.8-8.0% by weight of fine particles, and the density of the fiber divided by alkali weight loss is 1.
A polyester splittable conjugate fiber having a weight of 375 g / cm ³ or more.