JPH06240516A - Water absorbing composite fiber - Google Patents

Abstract

PURPOSE:To provide a composite fiber excellent in water absorption and moisture absorption and most suitable for the field of comfortable clothing. CONSTITUTION:There is provided a composite fiber having a sea-island structure containing inside island components of the cross section of the fiber each composed of a group of polyamide filaments and island components each composed of polyester filaments, having >=1.5 flatness of the cross section and arranged around the polyamide filament groups. This fiber is designed so as to have a specified relation between the number and the single fiber denier of the outside polyester fibers and the inside polyamide fibers and, therefore, characteristically excellent in moisture absorption and water absorption, free from wetness and excellent in comfortability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic fiber which is excellent in sweat absorption and hygroscopicity and is most suitable for the field of comfortable clothes, and further relates to a composite yarn for clothes which is comfortable even when sweating a lot.

[0002]

2. Description of the Related Art Synthetic fibers have excellent mechanical properties and uniformity,
It has been greatly developed as a fiber for clothing due to its easy care properties. However, there are problems such as a plastic feeling as a problem of uniformity and a cold feeling as a tactile sensation, and various improvements have been made to reach the present state. Among them, polyester is a fiber material for clothing that has a very excellent texture due to the technique of imparting a yarn length difference such as different shrinkage mixed fibers, the technique of alkali reduction, and the technique of roughening the fiber surface by combining this technique and the technique of adding a micropore-forming agent. Has grown to

However, a major problem that has not yet been solved is the problem of sweat absorption. As an attempt to solve this problem, an improvement utilizing the capillary phenomenon in consideration of the cross-sectional shape and surface morphology has been proposed, but the effect is small and the sweat-absorbing synthetic fiber has not yet appeared. As another improvement means, a method of chemically modifying polyester has been proposed. For example, a method of copolymerizing or blending a polyalkylene glycol, which originally has a hygroscopic property, is known, but not only the mechanical properties cannot be declined but also the light resistance of the dyed product is remarkably reduced. The range that can be done is considerably limited. As another improvement measure, there is a technique of imparting hydrophilicity by post-processing, but particularly in the case of polyester, there is no processing agent having excellent durability. There is also a method of graft-polymerizing acrylic acid or the like as a means for increasing durability, but polyester requires a swelling agent, which causes problems such as recovery of solvent, deterioration of mechanical properties, and deterioration of light resistance. On the other hand,
Polyamide can be graft-polymerized in an aqueous system, and although there are few problems, deterioration of light resistance is inevitable.

[0004] Although various improvements in hygroscopicity are more or less recognized, it does not lead to comfort as it is, and it is necessary to consider the separation of the absorbed moisture from the vicinity of the skin, especially when the amount of sweat is large. In many cases, clothes adhering to the skin feel uncomfortable due to the moisture adsorbed on the fiber surface, and the comfort of sweating cannot be discussed only by the water absorption and moisture absorption capabilities of the fiber. Taking this concept into consideration, hydrophobic fibers are arranged in the vicinity of the yarn surface, hygroscopic fibers are arranged in the middle layer, and fine denier fibers are arranged in the innermost part. However, there is a drawback in that the spun yarn is poor in aesthetics and it is difficult to make a thin yarn because it is a composite spun yarn.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art and is suitable for a fabric having no sticky feeling, excellent water absorbency and hygroscopicity, and an elegance peculiar to filament yarn. It is intended to provide composite fibers.

[0006]

Means for Solving the Problems The means for solving the above-mentioned problems, that is, the present invention, is a polyamide fiber group arranged as an inner island component and an outermost island component so as to surround the polyamide fiber group. A composite fiber comprising a polyester fiber group and a sea component composed of a polymer having high solubility in a solvent, wherein the polyamide fiber in the composite fiber is present in a proportion of 50% by weight or more based on the composite fiber, The polyester fiber arranged as an island component has a flatness of 1.5 or more, and the polyester fiber arranged at the outermost periphery has a single yarn denier (do) and the number of fibers (N
o) and the single yarn denier (di) and the number of fibers (Ni) of the polyamide fibers arranged inside satisfy the following formulas (1) and (2). 3.0 ≧ do> di ≧ 0.2 (1) 6 ≦ No <Ni ≦ 30 (2) (However, the above flatness Is expressed as major axis length / minor axis length.)

The important point of the present invention lies in the structure of the composite fiber, and it is important that the outer periphery of the raw yarn cross section is hydrophobic and the inside of the raw yarn cross section is hydrophilic. As a result, water drops during sweating can be taken into the inside of the yarn and the surface layer of the yarn can be kept dry. In order to achieve this object with a melt-spinnable polymer for synthetic fibers, it is necessary to make the fibers forming the outer layer of the raw yarn hydrophobic polyester and most of the fibers constituting the inside of the raw yarn hydrophilic polyamide. There is. The fibers composing the inside of the raw yarn may be a mixed state of polyester and polyamide, but the composition ratio of polyamide at this time is 50
Must be at least%. If it is less than 50%, the effect of putting hydrophilic fibers inside and improving the water retention performance cannot be exhibited. In addition, by using a combination of hydrophobic polyester and hydrophilic polyamide, it is possible to selectively polymerize acrylic acid and the like with hydrophilic polyamide only by using a water-based treating agent, and to increase hygroscopicity only inside the yarn. It can be increased.
As a method of producing a two-layer structure yarn by combining the two, it is not impossible to separately produce the both and then mix them to form a two-layer structure yarn, but the degree of perfection of the structure (two-layer structure fiber This is not ideal considering the fact that the establishment of the placement suitability) is not good and that the two-layer structure is broken due to various bends and handles received in the fabric making process.

The yarn of the present invention forms a complete two-layer structure in the spinning process, and is subjected to yarn making, cloth making, scouring, and heat setting with the form fixed by the elution component, and then the elution component is eluated to elute the elution component. The final product in which the two-layer structure is perfectly maintained by the binding force and the effect of fixing the form by heat setting can be obtained, and the product having excellent sweat absorption performance by the two-layer structure can be obtained. At this time, it is preferable that the outermost peripheral polyester has a flat cross section in the outer peripheral direction of the composite yarn in order to conceal the internal polyamide component, and in view of the concealment effect, the flatness must be 1.5 or more. If it is less than 1.5, not only is the hiding power poor, but the two-layer structure is likely to collapse.

The polyamide used in the composite yarn of the present invention has 2
There are two drawbacks. One is that the dyeability is different from that of the composite polyester, and when dyed with a disperse dye that dyes polyester, the colors of polyester and polyamide are different, and great expense and labor are required to match the colors. The other is that it is inferior in light resistance to polyester, and is easily discolored and resistant to light. Further, when acrylic acid is graft-polymerized with polyamide in order to improve the hygroscopicity, the light resistance is slightly adversely affected. Therefore, when the polyester and the polyamide are compounded, the above-mentioned drawbacks can be eliminated by covering the outer periphery of the composite yarn with the polyester, disposing the polyamide inside the composite yarn, and completely hiding the internal polyamide with the polyester. Also, by mixing an inorganic or organic fine pore-forming agent into the polyester placed on the outer circumference, and elution of sea components with an alkaline solution, a part of the polyester fiber on the outer circumference is eluted to form fine pores on the fiber surface, which also has a sweat absorbing ability. It is more preferable because it is improved and a dry touch can be imparted. The sea component used in the present invention is a highly soluble polymer. For example, a modified polyethylene terephthalate containing a dicarboxylic acid component having an isophthalic acid skeleton in an amount of 2.0 mol or more based on the total acid component, and a polyalkylene glycol of 6 are used. .0 to
An alkali easily eluting polyester which is melt blended with 20% by weight can be mentioned.

Further, when considering the sweat absorbing ability, the number of fiber constituents and the fiber denier in the composite yarn after elution are also important. The number of islands (No) of the island component existing in the narrow outer circumference is important in that the water between the islands becomes a migration path for water in the gas phase or liquid phase. If it is less than 6, this migration path is insufficient and sweat absorption performance is low. Is not enough. The number of island components (Ni) in the inner layer is preferably large in relation to the rate and amount of water adsorption, but 30 is the limit when considering the total denier of the composite yarn, the spinning nozzle structure and the processing cost. The fineness of the island component is also important in the same sense. The fiber denier (do) of the island component present in the outermost circumference needs to be 3 denier or less, and if it exceeds 3 denier, the entire composite yarn becomes hard and unsuitable for clothing use. The fiber denier (di) of the island component of the inner layer is preferably thin from the standpoint of enhancing sweat absorption performance and subdividing the gas storage phase, but 0.2 denier is the limit from the standpoint of the fabric tension. Further, it is possible to use a known technique of incorporating a pigment and a stabilizer modifier into the polyester and / or polyamide fiber. Further, it is also possible to impart a shrinkage difference between the composite fibers and use it as a heterogeneous shrinkage mixed yarn.

[0011]

EXAMPLES The present invention will be described in detail below with reference to examples.

Example 1 Intrinsic viscosity (30 ° C. phenol / tetrachloroethane =
(Measured in 6/4 solvent) is 0.60 and the average equivalent spherical diameter is 0.
Polyester containing 2% by weight of 3 μm kaolinite (Polymer A) was placed on the outermost island, and the relative viscosity (30 ° C.
Nylon 6 (polymer B) (measured with concentrated sulfuric acid) of 2.5 was melt-blended with 10% by weight of polyethylene glycol (average molecular weight: 20,000) in the inner layer island, and polyester in which 10 mol% of isophthalic acid component was copolymerized with polyester. Using a polymer (Polymer C) as a sea component, Fig. 1
The sea-island type composite fiber shown in was obtained. The spinning temperature was 280 ° C., and the spinning nozzle was modified from the nozzle described in JP-A-57-29605 so that the island component in the outermost periphery and the island component in the inner layer could be supplied from different gear pumps by different polymer passes. A nozzle for discharging 4 filaments as the composite fiber was used. The discharge amount of each polymer A was 10.
4 g / nozzle min, Polymer B is 13.0 g / nozzle
Min, Polymer C is 9.5g / nozzle / min and 1300m
It was wound up at a speed of about 1 minute. Same unstretching with hot roller temperature 8
It was drawn 3 times at 0 ° C. and a hot plate temperature of 150 ° C. to obtain a drawn yarn of 72 denier 4 filaments. After interlock knitting using the same yarn, it was scoured and preset. Then, the mixture was treated with a 30 g / l caustic soda solution at 90 ° C., reduced by 30% by weight, and washed with neutralized water. When this sample was freeze-fractured with liquid nitrogen and the vertical cross section was observed with a scanning electron microscope, the cross-sectional morphology shown in FIG. 1 was completely retained.

Further, the cross-sectional area was calculated from a cross-sectional photograph magnified 1000 times with a scanning electron microscope, and the obtained fiber denier was 1.0 denier 6 filaments for the outer peripheral fibers and 0.57 denier 13 filaments for the inner layer fibers. . Further, the flatness ratio of the outer peripheral fibers was 2.32 as a result of obtaining from the same photograph. The water absorption of this sample was evaluated by the following method. After the sample was dried at 120 ° C for 3 hours and the weight of the sample was measured, 20
After the sample was left in a thermostatic chamber at a temperature of 65 ° C and a humidity of 65% for 12 hours, the sample was measured again to calculate the increase in weight, and the rate of increase relative to the original sample weight was taken as the moisture absorption rate. Moreover, the cloth is spread on a horizontal surface and a 0.5 cc water droplet is dropped from a height of 5 cm,
The time until absorption in the fabric was measured, and the water absorption rates were stratified into 1 to 5 grades by relative comparison. (5th grade is better) At the same time, after completely absorbing, 3 minutes later, the water absorption surface was touched with a fingertip to relatively judge the wet feeling. The results are shown in Table 1. An improvement in hygroscopicity was recognized as compared with the case of 100% polyester.

Example 2 The sample obtained in Example-1 was washed with neutralized water, dried and graft-polymerized with a metal salt of polyacrylic acid under the following conditions. Graft polymerization conditions Acrylic acid 20 g / l Ammonium persulfate 0.5 g / l Sodium sulfite 3 g / l Aqueous solution 8
Treatment at 0 ° C. for 30 minutes Grafting rate: 5.6% Using this sample, the hygroscopicity was evaluated by the same method as in Example-1, and the results are shown in Table 1. The hygroscopicity was further improved by the graft polymerization.

Comparative Example 1 Example 1 except that the polymer B was a polyester containing 0.5% of titanium oxide (intrinsic viscosity of 0.63 measured with a solvent of phenol / tetrachloroethane = 6/4).
Spinning, drawing, knitting, scouring, and alkali weight loss treatment were carried out in exactly the same manner as above. Further, the hygroscopicity was evaluated by the same method as in Example-1, and the results are shown in Table 1. No hygroscopicity was observed.

[0016]

[Table 1]

[0017]

INDUSTRIAL APPLICABILITY The present invention is a composite fiber that produces a two-layer structure composite yarn having a hydrophobic outer periphery and a hydrophilic interior, and has the ability to express the elegance peculiar to filament yarn and the sweat absorbing ability without stickiness. It is possible to provide a composite fiber for forming a fabric having a joint.

[Brief description of drawings]

FIG. 1 is a view showing a cross section of a conjugate fiber of the present invention.

[Explanation of symbols]

1 is a polyester fiber arranged on the outer periphery, 2 is a polyamide fiber arranged on the inner side, and 3 is a sea component.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location D06M 11/38 // D06M 14/34

Claims (1)

[Claims] 1. A sea composed of a polyamide fiber group disposed as an inner island component, a polyester fiber group disposed as an outermost peripheral island component so as to surround the polyamide fiber group, and a polymer having a high solubility in a solvent. It is a composite fiber composed of components, and the polyamide fiber in the composite fiber is present in a ratio of 50% by weight or more with respect to the composite fiber, and the cross section of the polyester fiber arranged as the outermost peripheral island component has a flatness of 1.
It is 5 or more, and the single yarn denier (do) and the number of fibers (No) of the polyester fiber arranged at the outermost circumference and the single yarn denier (di) and the number of fibers (Ni) of the polyamide fiber arranged inside are A composite fiber satisfying the following formulas (1) and (2). 3.0 ≧ do> di ≧ 0.2 (1) 6 ≦ No <Ni ≦ 30 (2) (However, the above flatness Is expressed as major axis length / minor axis length.)