JP2006225821A - Polylactic acid fiber structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber structure produced by post-processing and reversibly color changing with a sufficient color density by an irradiation with light. <P>SOLUTION: This invention relates to the polylactic acid fiber structure using the polylactic acid fibers at least a part of the fiber structure which exhibit an excellent optical transmittance in visible light region and a remarkably reduced amount of energy absorption in ultra violet region as compared to common fibers, wherein the fiber structure exhibits a sufficient and homogeneous reversible color changing property and a high color density by manifesting a sufficient and homogeneous reversible color changing property caused by the effect of lights penetrating inside of fibers in a region not directly irradiated with the light by fixing optically reversible color changing fine particles on the surface of the fiber or between fibers. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fiber structure in which photoreversible color-changing fine particles are fixed between fiber surfaces and / or fibers of a fiber structure using at least part of polylactic acid fibers.

Examples of the fibers imparted with photoreversible discoloration until now include the photochromic fibers described in Patent Document 1 spun by blending an inorganic photochromic compound and the patent documents 2, 3, 4, and 5 blended and spun by an organic photochromic compound. There is known a fiber product comprising cellulose fiber described in Patent Document 6, which is treated by dipping in a dispersion liquid containing vinylidene chloride fiber, acrylic fiber, vinyl chloride fiber and polyolefin fiber, and photoreversible discolorable fine particles. Yes.
JP-A-3-287811 JP-A-6-280112 JP-A-6-313210 JP 7-118918 A JP 2001-207326 A JP-A-5-33276

  Optically reversible discolorable fibers that are spun together with inorganic photochromic compounds or organic photochromic compounds are modified at the raw yarn stage, so they can be produced in a wide variety and in small lots for fiber materials of various forms and configurations. It is impossible to meet the request. When applied to a textile product made of a knitted fabric, the pattern expression is limited to a range that can be expressed by the structure of the knitted fabric.

  In the case of fiber products made of cellulose fibers that have been immersed in a dispersion containing photoreversible color-changing fine particles, the fiber reversible color-changing fine particles are mainly adsorbed on cellulose fibers such as cationized cotton. . Since such products can be manufactured by post-processing, they can be used for multi-variety and small-lot production of various material configurations and various colors. The photoreversible color-changing cellulose fiber thus obtained has good color-changing properties in a region that is directly irradiated with light, while color change is poor in a shaded region that is not directly irradiated. As a result, discoloration is uneven and only a part of the photoreversible color-changing fine particles is discolored, so that the overall color density cannot be sufficiently increased.

  In view of the above-described conventional circumstances, the present invention can be manufactured by post-processing capable of handling various types and small lot production, and exhibits sufficient and uniform reversible discoloration even in an area not directly irradiated with light. An object of the present invention is to provide a fiber structure having a photoreversible discoloration that can be discolored to a high color density.

  In order to obtain a photoreversible color-changing fiber structure by post-processing that can be used for multi-product / small-lot production, the inventors of the present invention fix photoreversible color-changing fine particles with a binder between fiber surfaces and fibers. The method was considered appropriate.

  In addition, the inventors diligently investigated the cause of the loss of reversible discoloration in the shaded areas that are not directly exposed to light in a fiber structure in which photoreversible discolorable fine particles are fixed in the fiber surface or between fibers by post-processing. As a result of research, it was found that the light permeability and the light energy absorption of the fiber material are greatly related to the reversible discoloration. That is, in order to change the color of the photochromic compound, it is generally necessary to be excited by ultraviolet rays having a wavelength of about 300 to 360 nm, and when there is a photochromic compound in a place where light such as between the fibers or shade is not directly irradiated, Must be excited by the action of ultraviolet light passing through On the other hand, in order for the color of the excited photochromic compound to be captured by human vision, visible light having a wavelength of 400 to 700 nm needs to be emitted outside without being disturbed.

  Natural fibers such as cotton have poor light transmission, so photochromic compounds that do not receive direct light irradiation are not excited and discolored, and visible light cannot pass through the fiber even in the colored part. Color development where it is not directly visible does not contribute to an increase in color density. On the other hand, synthetic fibers such as polyester have visible light permeability, and the color of the photochromic compound discolored inside the fiber bundle passes through the fiber and is visually perceived. When fine particles are fixed, reversible discoloration is better than natural fibers such as cotton. However, polymer materials such as polyester often absorb relatively large energy in the ultraviolet region even though they have visible light permeability. Therefore, the light energy in the ultraviolet region is consumed competitively between the excitation of the photochromic compound and the energy absorption by the fiber, causing a delay in discoloration response and a decrease in discoloration density.

  Based on the above considerations, as a result of comparing and examining the visible light transmittance of various fiber materials and the energy absorption in the ultraviolet region, in order to achieve the above purpose, as a fiber material, attention has recently been paid as a biodegradable fiber. It came to the idea that it is necessary to use polylactic acid fibers that have been collected. This polylactic acid fiber is a characteristic fiber material that exhibits good light transmittance in the visible light region and hardly absorbs energy up to the ultraviolet region up to a wavelength of about 250 nm. In the present invention, the photoreversible color-changing fine particles are fixed between the fiber surface and the fibers of the fiber structure using at least a part of the polylactic acid fiber, so that it is sufficient and uniform even in the region not subjected to the direct light irradiation for the above purpose. The present invention has led to the completion of a photoreversible color-changing fiber structure that exhibits a reversible color-change property and can be changed to a high color density.

  If a fiber structure using at least a part of polylactic acid fiber that can be realized by the above means is used for curtains, parasols, T-shafts, etc., as a specific application, it is possible to realize a value-added product using light reversible discoloration .

  Since the present invention is configured as described above, the following effects can be obtained.

  A fiber structure such as a spun yarn mainly composed of polylactic acid fibers in which photoreversible discolorable fine particles are fixed between fiber surfaces and fibers is directly irradiated with light including ultraviolet rays such as sunlight. Reversible discoloration is exhibited not only in the irradiated portion, but also in the interior and on the opposite surface, and can be discolored at a uniform and sufficiently high color density as a whole. And its reversible discoloration is a good response that it changes color more quickly when irradiated with light compared to fiber materials that absorb energy in the ultraviolet region, such as polyester, and quickly returns to its original color when stopped. Can show gender.

  When products such as curtains and parasols are manufactured using yarns mainly composed of polylactic acid fibers with photoreversible discolorable fine particles fixed on the fiber surface or between the fibers, not only the surface that receives light irradiation but also the opposite Good reversible discoloration can also be obtained on the surface, so the reversible discoloration can be observed from the user's viewpoint, from the inside when using a curtain, from the bottom when opening a parasol, and the discoloration density. It is possible to know the ultraviolet intensity according to the degree of.

  In the manufacturing method in which the photoreversible color-changing fine particles are fixed with a binder by post-processing between the fiber surfaces and the fibers, it is possible to deal with various forms and configurations of materials in a variety of products and in a small lot. In addition, by applying traditional dyeing techniques such as uneven dyeing and screen printing, it is possible to express various patterns that are impossible with products made of photoreversible color-changing fibers manufactured by modifying the raw yarn stage. Become.

  Examples of the form of the fiber structure using at least a part of the polylactic acid fiber used in the present invention include yarns, woven fabrics, knitted fabrics, non-woven fabrics, and fiber products and sewing products composed of them. Specific examples of textile products and sewing products include curtains, parasols, hats, bags, T-shirts, trainers, jumpers, trousers, and the like. In particular, with regard to the form of the yarn containing polylactic acid fiber, there is a spun yarn that can maintain a dense state without much change in the positional relationship of each single fiber in the fiber bundle in terms of good retention of the photoreversible discolorable fine particles. preferable. If it can be firmly bonded with a large amount of binder, it can be carried out using filament yarn. In order to obtain a quick responsive photoreversible discoloration at a high color density, it is preferable that the yarn is composed of polylactic acid fiber alone, but in order to adjust the fiber properties, cellulose fibers such as cotton and hemp are used. Threads mixed with protein fibers such as wool and silk, regenerated fibers such as viscose rayon, semi-synthetic fibers such as acetate, synthetic fibers such as polyester, nylon, and acrylic can also be used.

  The photoreversible color-changing fine particles used in the present invention are not particularly limited as long as they can be reversibly discolored by light irradiation. Specifically, inorganic photochromic pigments such as titanium oxide-based, barium titanate-based, calcium titanate-based, organic photochromic compounds such as spiropyran-based, spirooxazine-based, fulgide-based, naphthopyran-based, and benzopyran-based are included in the polymer compound. It can be selected from contained fine particles. Among them, microcapsules made of a polymer compound containing an organic photochromic compound are commercially available and can be preferably used in the present invention. The particle size of the photoreversible color-changing fine particles is preferably as small as possible within the range where there is no problem with the photoreversible color-changing property in order to fix the fiber surface or between the fibers, and is at most 30 microns or less. It is desirable that it is 20 microns or less.

  The binder used in the present invention is used for fixing the photoreversible color-changing fine particles to the fiber, and has an appropriate hardness, flexibility, adhesive force, various durability and stability, It can be used without any particular restrictions. Although a specific composition cannot be generally stated, acrylic resins, acrylic ester resins, epoxy resins, urethane resins, and the like can be given.

  In the present invention, the method of fixing the photoreversible discolorable fine particles with the binder between the fiber surface of the fiber structure and between the fibers is not particularly limited as long as it is a method that is usually performed to fix the fine particles to the fiber with the binder. It can be implemented without being done. As a typical example, the fiber structure is previously cationized or anionized in the same manner as in the pigment dyeing method, and anionic or cationic photoreversible discolorable fine particles are added to the fiber structure. After adsorbing in a water bath, a method may be employed in which a binder is added and coated, followed by fixing by drying and heat treatment. Further, as another method, a photoreversible color-changing fine particle is mixed in a binder, and this is applied to a fiber structure by a usual application method such as screen printing, dipping method, brush coating, etc., and then dried and heat-treated. A method of fixing can be performed.

  Embodiments of the present invention will be described below with reference to the drawings based on examples. However, the present invention is not limited to the following examples.

  First, as a pretreatment of the polylactic acid fiber, a cationization treatment with a quaternary ammonium salt polymer compound (manufactured by Senka Co., Ltd., trade name: KZ-76K) was performed in a water bath. The treatment was carried out at 70 ° C. for 20 minutes at a bath ratio of 1:20 using 4 parts by weight of KZ-76K per 100 parts by weight of polylactic acid spun yarn of 20th twin yarn.

  Subsequently, the photoreversible color-changing fine particles (microcapsule photochromic dye manufactured by Matsui Dye Chemical Co., Ltd., trade name: Photopia AQ INK) are adsorbed on the cationized polylactic acid yarn in a water bath, and further The photoreversible color-changing fine particles adsorbed on the fiber surface or between the fibers were fixed with a binder. The treatment in the water bath with the photoreversible color-changing fine particles was carried out using 20 parts by weight of Photopia AQ INK with respect to 100 parts by weight of the cationized polylactic acid spun yarn at a bath ratio of 1:20 and from room temperature to 2 ° C./min at 70 ° C. The temperature was raised to. The fixing treatment with the binder following the photoreversible color-changing fine particle treatment is 10 parts by weight of an acrylic binder (manufactured by Matsui Dye Chemical Co., Ltd., trade name: Binder MR-Y) with respect to 100 parts by weight of the polylactic acid spun yarn in the bath. ) And held at 70 ° C. for 15 minutes to adsorb the binder to the yarn, lightly washed with water, dehydrated and dried, and then heat treated at 130 ° C. for 3 minutes.

  FIG. 1 shows an enlarged cross-sectional view of the polylactic acid yarn to which the photoreversible color-changing fine particles thus obtained are fixed. A binder covers and adheres the photoreversible discolorable fine particles adsorbed on the fiber surface or between the fibers.

  A fabric was knitted by using the 20th double yarn polylactic acid spun yarn to which the photoreversible color-changing fine particles were fixed as a warp at a rate of once every four yarns, and a curtain was produced from this fabric. When this curtain was exposed to sunlight, the photo-reversible color-changing yarn changed to blue, purple, yellow, etc. depending on the type of Photopia AQ INK, and its color density was sufficient even when viewed from the indoor side. In addition, it was possible to visually inform the indoor ultraviolet light intensity by changing the color to darker on the day when strong sunlight enters and lighter on the cloudy day.

  The photoreversible color-changing fine particles were fixed to a T-shirt produced from a knitted fabric made of spun yarn containing polylactic acid fibers and cotton fibers at a ratio of 1: 1 by applying a conventional uneven dyeing technique.

  First, as a pretreatment of the T-shirt, a cationization treatment with a quaternary ammonium salt polymer compound (manufactured by Senka Co., Ltd., trade name: KZ-76K) was performed in a water bath. Using 100 parts by weight of T-shirt and 4 parts by weight of KZ-76K, treatment was performed at a bath ratio of 1:25 at 70 ° C. for 20 minutes.

  Subsequently, the cationized T-shirt is partially squeezed with a string, and photoreversible discolorable fine particles in a water bath (microcapsule photochromic dye manufactured by Matsui Dye Chemical Co., Ltd., trade name: Photopia AQ INK). Then, the photoreversible discolorable fine particles adsorbed on the fiber surface and between the fibers were fixed with a binder. The treatment in the water bath with the photoreversible color-changing fine particles was carried out using Phototopia AQ INK at 15 parts by weight with respect to 100 parts by weight of the cationized T-shirt at a bath ratio of 1:25 and increasing from room temperature to 70 ° C. at 2 ° C./min. Goed warm. The fixing process with the binder following the process of the photoreversible color-changing fine particles is 10 parts by weight of an acrylic binder (manufactured by Matsui Dye Chemical Co., Ltd., trade name: BINDER MR-Y) in a bath with respect to 100 parts by weight of the T-shirt. It was added and held at 70 ° C. for 15 minutes to adsorb the binder, lightly washed with water, dehydrated and dried, and then heat treated at 130 ° C. for 3 minutes.

  T-shirts with photoreversible color-changing fine particles fixed by this traditional uneven dyeing technique change to blue, purple, yellow, etc. depending on the type of Photopia AQ INK under sunlight, which is visually sufficient A color change with an enjoyable density was obtained.

  An example in which a binder containing photoreversible discolorable fine particles was applied to polylactic acid yarn using a gluing machine is shown below. Binder (Matsui Dye Chemical Co., Ltd., trade name: Binder S) 77 parts by weight, photoreversible discolorable fine particles (Matsui Dye Chemical Co., Ltd. microcapsule photochromic dye, trade name: Photopia AQ INK) 20 Part by weight and 3 parts by weight of a fiber modifier (manufactured by Matsui Dye Chemical Co., Ltd., trade name: Fixer F) are mixed to prepare a treatment liquid, and this liquid is converted into a 300-denier polylactic acid multifilament yarn using a gluing machine. Applied. The polylactic acid yarn coated with the treatment liquid was dried and then heat treated at 130 ° C. for 3 minutes.

  A 300-denier polylactic acid filament yarn to which the photoreversible discolorable fine particles were fixed was used as an embroidery thread on a fabric for a parasol, and a parasol partially embroidered with a photoreversible discolorable fiber was produced. When this parasol is exposed to sunlight, the photo-reversible discolorable yarn changes to blue, purple, yellow, etc. depending on the type of Photopia AQ INK, and its color density is sufficient even when viewed from the underside of the parasol. The product that the person can enjoy the color change visually was obtained.

  The polylactic acid fiber structure to which the photoreversible color-changing fine particles of the present invention are fixed exhibits reversible color change not only in the portion directly irradiated with sunlight but also in the inside and the opposite surface, and is uniform and sufficiently high in color as a whole. Can change color to density. In addition, since the photoreversible color-changing fine particles are fixed with a binder by post-processing, it is possible to deal with various types and configurations of materials in various varieties and small lots. Therefore, it may be used in a wide range of fields such as interior applications such as curtains, general clothing applications such as T-shirts, parasols, hats and bags.

Enlarged cross-sectional view of polylactic acid yarn to which photoreversible discolorable fine particles are fixed

Explanation of symbols

1 Cross section of polylactic acid fiber 2 Reversible color-changing fine particles 3 Binder

Claims (4)

  A fiber structure characterized in that photoreversible color-changing fine particles are fixed with a binder between a fiber surface and / or between fibers of a fiber structure using at least a part of a polylactic acid fiber.   2. The fiber structure according to claim 1, wherein the fiber structure using at least a part of polylactic acid fibers, to which the photoreversible discolorable fine particles are fixed, is particularly a curtain.   2. The fiber structure according to claim 1, wherein the fiber structure using polylactic acid fiber at least in part and to which the photoreversible discolorable fine particles are fixed is particularly a parasol.   2. The fiber structure according to claim 1, wherein the fiber structure using at least a part of polylactic acid fibers to which the photoreversible color-changing fine particles are fixed is particularly an outerwear such as a T-shirt.

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