KR920008975B1 - Process for the production of conjugated fiber - Google Patents

Abstract

In multi-segment type composite fiber structure, fiber- forming polamide composition forms radial shapes by branching into 4-8 direction radially from the center of fiber cross section, while fiber-forming polyester composition forms wedge shapes by arranging the composition alternately between polyamides. The polyester composition contains 5 mμ - 50 mμ 0.1-3.0 wt.% silicon dioxide microparticles which can impart multiple concave convex of 0.4 - 0.8 μ along the fiber axis during alkali weight reduction. Low refractive resinous coats, e.g. polyurethane of refraction index 1.4-1.6 are applied to the alkali treated composite fiber to give good shade producibility after dyeing.

Description

Manufacturing method of composite fiber structure

1 to 3 are cross-sectional enlarged views of the composite fiber of the present invention, A: fiber-forming polyamide-based resin, and B: fiber-forming polyester-based resin.

The present invention has a number of fine irregularities of optical wavelength order in the fiber side by alkali reduction treatment on the surface of the fiber and at the same time forms a resin film of low refractive index, and has a significant deep color effect and high color compared to general ultrafine fibers during dyeing. The present invention relates to a method for producing a polyamide-polyester-based composite microfiber structure capable of exhibiting color development.

In general, microfibers of less than 0.3 denier (denier) has a variety of uses, such as artificial suede (suede), moisture-permeable waterproofing, clean fabrics, but there are difficulties in the process, such as dyeing process has a lot of restrictions on their use. Microfibers are known to have a lower apparent surface concentration (chromic) than conventional fibers, which is a common problem with microfibers. As the decrease in the apparent concentration, as the fiber becomes thinner, the surface area with respect to the unit weight increases and the reflected light on the surface of the fiber increases, so that the light scatters and the colored light is weakened, so that the apparent concentration of the surface is deteriorated. If the apparent concentration is lowered, the color fastness of the regular denier fibers cannot be obtained unless a high concentration of the dye is used.

On the other hand, as a method of imparting irregularities to the surface of the fiber to improve color development, the method of adding polymers of inert fine particles and crystallization agents disclosed in Japanese Patent Publication Nos. 68-14186 and 71-26887 and Japanese Patent Publication No. 68-16665 Solvent treatment after addition of the disclosed fine particles is known, but such a method is difficult to obtain a sufficient deep color effect by forming irregularities of several to tens of times the wavelength of light on the fiber surface. In addition, the method disclosed in Japanese Patent Application Laid-Open No. 80-137241 is formed in the circumferential direction perpendicular to the fiber axis so that the tearing and tensile strength of the fiber structure is lowered, and the deep refractive index of the polyester fiber itself has a deep color effect. There is not enough to gain. In order to solve this drawback, the present inventors minimize the reflected light by eluting the fine particles in the alkali reduction process to form fine irregularities of 0.4 to 0.8 μ of an optical wavelength order on the surface of the fiber to diffuse the light diffusely while forming a resin film having a low refractive index. The method for producing a highly colored polyamide-polyester-based composite microfiber structure was invented.

The present invention will be described in detail as follows.

The present invention relates to a fiber-forming polyamide-based resin as a first component in a multi-segment composite fiber composed of a fiber-forming polyamide and a fiber-forming polyester. Branched radially at the center of the cross section of the composite fiber as shown in to form a radial portion of four directions or more and eight directions or less, and the fiber-forming polyester resin, the second component, alternates with the first component between the first component. It is arranged in the form of a wedge, the second component is used as a thermoplastic polyester resin to contain inorganic particles having an average diameter of 50mμ ~ 50mμ to form a plurality of fine irregularities on the fiber surface when reducing alkali, the composite It is characterized by forming a resin film having a refractive index of 1.4 to 1.6 after reducing the fiber alkali.

The inorganic particles used in the present invention are silicon oxide (SiO ₂ ) dispersed in water, having an average particle diameter of less than 5 mμ, which is not sufficient for the effect of unevenness after reducing the alkali, and the dispersion itself is expensive and has difficulty in practical use. The above has disadvantages in that the formation of too large unevenness in the optical wavelength is insufficient, so that the light scattering effect is insufficient and the strength degradation of the fiber is remarkable. The content of such inorganic particles may vary depending on the shape and density of the desired irregularities after the weight loss processing, but 0.1 to 3% by weight of the polyester resin is suitable to prevent splitting and trimming during spinning. If the content is less than 0.1% by weight, the formation of unevenness is insufficient, which does not help the color development after dyeing. If the content is more than 3% by weight, the segment is separated during the sacrificial process, so that not only the bleeding occurs but also the severed thread. In addition, trimming occurs during the weaving and knitting process, causing instability and faulty operation. In addition, after the reduction of alkali, the strength decreases remarkably, and thus does not function as a fiber product.

The present invention is a composite spinning of the fiber-forming polyamide and the fiber-forming polyester resin containing the inorganic particles described above to have a total fineness of 50 ~ 150 denier, single yarn fine 1 ~ 3 denier and weaving or knitting to a chemical method or physical After dividing and minimizing by the method, fine irregularities were formed by extracting the inorganic particles by alkali reduction processing, and then a low refractive index resin coating was applied to the fiber surface to improve deep color and color development. The chemical method at the time of dividing is dividing the solvent selectively acting on the two-component polymer forming the fiber by dipping or padding method, and the solvent used is benzyl alcohol, phenyl ethyl alcohol (phenyl). ethyl alcohol, phenol, ortho chlorophenol, m-cresol, para-cresol, alpha methyl alcohol, ortho phenyl phenol Although (O-phenyl phenol) is known, benzyl alcohol is known to be suitable in consideration of safety, workability, and price. As a physical method, dividing by needle-napping and buffing is a typical method used in the manufacture of suede. In some cases, chemical and physical methods may be combined.

In general, the weight loss of polyester fibers is due to hydrolysis of ester groups in the polyester polymer chain to form terephthalic acid and ethylene glycol, and neutralization of terephthalic acid to disodium terrphthalate. It is known that the weight loss occurs as a) and hydrolysis occurs slowly from the fiber surface due to the compactness of the polyester fiber structure, because the rate of alkali decomposition is faster than the penetration rate of alkali into the fiber. If the inorganic particles are distributed on the surface of the polyester fiber, the structure around the inorganic particles becomes relatively loose due to micro voids and the like, so that the hydrolysis effect is increased, and finally, the inorganic particles are eluted out of the fiber and fine on the fiber surface. Unevenness is formed.

Fine unevenness scatters the light when the light is incident on the fiber, thereby reducing the reflected light on the surface of the fiber, that is, the white light, which in turn increases the colored light of the dye, resulting in high color development. Polyester fibers have the highest refractive index among the fibers, which is one factor that inhibits the color development of the polyester fibers. As another method of improving the color depth of polyester fiber, when the low refractive index resin of refractive index 1.4-1.6 is apply | coated to a fiber surface, it is known that surface reflectance of light falls and color development and color depth are improved. Low refractive index resins include fluorine compounds, mixtures of silicon oxide and hydrophilic vinyl monomers, mixtures of silicon oxide and water-soluble polyamide resins, polyurethane resins, mixtures of polyurethane and silicone compounds, etc. Is proposed.

Inorganic particles used for the purpose of forming the unevenness in the present invention is a colloidal silica (Colloidal Silica) of 10 to 50% by weight of silicon oxide finely dispersed in water with an average particle diameter of 5mμ-50mμ in water, 9.0 to 11.0 hydrogen ion concentration It was used in the polymerization step of the polyester resin at any stage. The alkali weight loss was appropriately divided by chemical or physical method and then carried out by a known method to reduce 5 to 15% by weight based on the weight of the fiber. That is, considering the polyamide component, the weight loss was 7 to 20 wt% based on the polyester component.

The single yarn fineness of the polyester component after the dividing treatment is less than 0.3 denier, and the surface area of the polyester component is larger than that of regular denier fibers. In addition, when the dividing process is performed with benzyl alcohol, the micro voids in the fiber formed by the benzyl alcohol treatment increase the surface area, increase the number of collisions of the hydroxyl group and facilitate the penetration of the hydroxyl group into the fiber. As the decomposition effect is increased, it is necessary to make the processing conditions more mild.

In the present invention, as the low refractive index resin, a heat-reactive polyurethane was used in consideration of dry cleaning durability and tactile feeling, and the polyurethane was a self-emulsifying type in which isocyanate was sealed with bisulfite. Self-contained urethane polymers with block or random copolymer polypropylene diol and hexamethylene diisocyanate or zylene dipropylene of propylene oxide and ethylene oxide An example in which the terminal isocyanate group of the urethane prepolymer obtained by reacting isocyanate (xylene diisocyanate) is sealed with bisulfite.

The amount of the urethane is preferably to be attached to the resin solid content of 0.1 to 5.0% by weight based on the weight of the fiber.

Hereinafter, the present invention will be described in detail with reference to Examples.

Example 1

Nylon 6 with a relative viscosity of 2.6 in sulfuric acid at 25 ° C and 96% as the first component, 1.0 wt% of silicon oxide with an average input of 15 mμ, and 0.64 intrinsic viscosity in ortho chlorophenol (O-chlorophenal) at 25 ° C. Phosphorous polyethylene terephthalate (ployethyleneterephthalate) as a second component was melt spun at a volume ratio of 1: 3 and wound at a speed of 1,500 m / min to obtain an undrawn yarn having a cross-sectional shape as shown in FIG. This was stretched three times at 130 ° C. and heat-fixed with a hot plate at 150 ° C. to obtain 75 denier 36 filament multisegment composite fibers. After using 75 denier 36 filament regular polyethylene terephthalate fiber as a warp yarn and weaving into a plain weave using the composite fiber as a weft yarn, dividing is performed by dipping in benzyl alcohol emulsion dispersion so that the split ratio is 90% or more. It was boiled with an aqueous sodium hydroxide solution so as to be. The alkaline treated fabric was padded in a 10% aqueous solution (1.5% solids) of water-soluble urethane prepolymer ＂ELASTRONC-52＂ (Cheil Industries, Ltd., Japan) and woven into a mangle to make a 70% pick-up. After drying for 2 minutes at 80% and heat-treated for 1 minute at 160 ℃.

The fabric after the treatment was dyed by high pressure in red by a conventional method to evaluate the uneven size, color development and strength reduction rate of the dyed fabric is shown in Table 1.

Comparative Example 1

The same process as in Example 1 was carried out except that the silicon oxide was not contained in Example 1. The results are shown in Table 1.

Comparative Example 2

The same process as in Example 1 was carried out except that the silicon oxide content in Example 1 was 0.05% by weight. The results are shown in Table 1.

Comparative Example 3

The same process as in Example 1 was carried out except that the silicon oxide content was contained in Example 1 by 5.0 wt%. The results are shown in Table 1.

Comparative Example 4

The same procedure as in Example 1 was carried out except that the water-soluble urethane prepolymer treatment was not performed in Example 1. The results are shown in Table 1.

TABLE 1

[Assessment Methods]

1. uneven size

The negative axial length was measured by scanning electron microscopy.

2. Color development

Compared with the standard fabric, the degree of improvement in color development was determined. The standard fabric was subjected to alkali weight loss treatment after the split treatment so as not to contain silicon oxide in the second component, and to avoid the water-soluble urethane prepolymer treatment. It prepared by the same method as in Example 1. The obtained dyed cloth was observed under natural light, and ten judges were selected according to the following criteria, and the sensory test was carried out, and these values were averaged and taken as judgment values.

Class 1: Color development is not improved compared to standard cloth.

2nd class: Color development is slightly improved compared to standard cloth.

Class 3: Color development is significantly improved compared to standard fabrics.

3. Strength reduction rate

The percentage of tear strength and tensile strength of the weft of the standard fabric was expressed as a percentage, and the calculation was performed as follows.

only,

Here, the tear strength was evaluated by KS K0535 (pendulum) and tensile strength KS K 0520 (ravel strip method).

4. Radioactive

The results were evaluated by considering the operability such as splitting, mooring and trimming during spinning.

Claims (3)

In the multi-segment composite fiber composed of fiber-forming polyamide and fiber-forming polyester, the fiber-forming polyamide-based resin as the first component is branched radially at the center of the cross section of the composite fiber in four directions or more. The fiber-forming polyester resin, which forms a radial portion of eight directions or less, and is a second component, is arranged alternately with the first component between the first component to form a wedge portion. The second component contains inorganic fine particles to reduce alkali. It uses thermoplastic polyester resin to form a number of fine unevenness of 0.4 to 0.8μ in the fiber side direction at the fiber side, and forms a resin film having a refractive index after alkali reduction of the composite fiber to show high color development after dyeing. Method for producing a composite fiber structure. The method for producing a composite fiber structure according to claim 1, wherein the inorganic fine particles are 5 to 50 mμ of silicon oxide (SiO ₂ ) and the content of fragrance is 0.1 to 3.0 wt% based on the polyester resin. The method of manufacturing a composite fiber structure according to claim 1, wherein the low refractive index resin film is a polyurethane having a refractive index of 1.4 to 1.6.

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