JP2009091701A - Decoloration method and discoloration method for fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decoloration method for fiber which enables more natural decoloring, and a discoloration method for off-white fiber, while considering environment. <P>SOLUTION: A Xe excimer lump 2 is scanned at a predetermined position relative to a jeans 6. At a part where the denim cloth of the jeans 6 projects, the Xe excimer lamp 2 and the denim cloth are relatively approached each other, strength of UV light is relatively increased and decoloration is prompted, meanwhile, at a part where the denim cloth is recessed, the Xe excimer lamp 2 and the denim cloth are relatively apart from each other and the strength of UV light is relatively decreased and degree of decoloration promotion is decreased. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for decoloring and fading a fiber, and more particularly to a method for decoloring a dyed fiber and a method for fading a formed fiber.

  As one of the dyed fiber products, there is a fiber product using a denim fabric typified by jeans. In recent years, such jeans and the like have been accepted by consumers, rather than remaining dyed, having a sense of wear over time (used feeling). In order to give jeans a secondhand feeling, the jeans and the like are preliminarily decolorized. In order to create a more natural used feeling, various decoloring methods have been proposed for textile products.

  Conventionally, there is a technique called a stone wash method, a sand paper and grind method, a sand blast method, or the like, which physically scrapes a portion of a textile product to be decolorized. However, these methods of physically decoloring fiber products have a problem that it takes time to remove stones and the like that have entered the fibers after decolorization.

Therefore, as a decolorization method for solving such problems, a method of chemically decoloring a textile product by immersing jeans or the like in a predetermined chemical solution in an electrolytic cell has been proposed. Note that Patent Documents 1 to 3 are examples of documents disclosing a method for decoloring a textile product using such a chemical solution.
JP 11-36173 A JP-A-10-226957 JP 2003-306879 A

  However, the method of chemically decolorizing textile products with a chemical solution has a problem that it takes time to process the chemical solution used in consideration of the environment. In addition, there is a problem that it is difficult to make a textile product a more natural used feeling.

  The present invention has been made to solve the above-mentioned problems, and one object is to provide a method for decoloring a fiber that is environmentally friendly and capable of performing more natural decolorization. The objective is to provide a method for fading the resulting fibers.

  The fiber decoloring method according to the present invention includes a step of irradiating the dyed fiber with predetermined light in the ultraviolet region.

  According to this fiber decoloring method, the pigment is decomposed by ultraviolet rays, and the environment-friendly fiber decolorization can be performed.

  Specifically, the dyed fiber preferably includes denim fabric dyed with indigo as a dye. Thereby, decoloring of the textiles represented by the jeans using denim cloth can be performed easily.

  Specifically, it is preferable to use an ultraviolet lamp or an ultraviolet laser oscillator as the light source of the predetermined light.

  In particular, by using an ultraviolet lamp, a gradation of decoloring can be easily obtained, and a more natural used feeling of fibers can be brought out.

  When an ultraviolet laser oscillator is used as the light source, it is preferable to dispose a predetermined optical element that spreads the light beam of the laser beam emitted from the ultraviolet laser oscillator between the ultraviolet laser oscillator and the fiber. By disposing such an optical element, a gradation of decolorization can be easily obtained.

  The method for fading a fiber according to the present invention includes a step of irradiating the fiber with predetermined light in the ultraviolet region.

  According to this fiber fading method, the components of the fiber are decomposed by ultraviolet rays, and the environment-friendly fiber fading can be performed.

  Specifically, it is preferable that the fibers include produced fibers. By fading the produced fiber, a natural used feeling can be given at the time when the fiber product is manufactured.

  Specifically, it is preferable to use an ultraviolet lamp or an ultraviolet laser oscillator as the light source of the predetermined light.

Embodiment 1
(Basic evaluation)
First, as a basic evaluation of a method for decolorizing a textile product using ultraviolet rays, a description will be given of the decoloration evaluation of a textile product test piece using an ultraviolet lamp and the results.

  As shown in FIG. 1, first, an indigo denim fabric having a size of about 130 mm × 50 mm was prepared as a test piece 4 of a textile product. In addition, as the denim fabric, unprocessed one (test piece A), one-washed one (test piece B), one-washed neutral bio-processing for ten minutes (test piece C), The one-wash process was subjected to biostone processing for 5 minutes (test piece D), and the one-wash process was subjected to biostone processing for 10 minutes (test piece E).

  Note that the one-wash process is a process of performing drying by performing hot water washing (70 ° C. × 5 minutes) and water washing (3 minutes) in a predetermined washing machine. Neutral bioprocessing is processing that performs bioenzyme washing (50 ° C. × 10 minutes) and water washing (2 minutes) in a predetermined washing machine, followed by drying. Biostone processing is processing that puts stones into a predetermined washing machine, performs bioenzymatic washing (50 ° C. × 5 minutes or 50 ° C. × 10 minutes) and water washing (2 minutes), and then performs drying.

  Then, an Xe excimer lamp (wavelength 172 nm) 2 was prepared as an ultraviolet lamp, and five Xe excimer lamps 2 were arranged at predetermined positions with respect to the denim fabric of the test piece 4. The distance H between the Xe excimer lamp 2 and the test piece 4 was about 3 mm, and the gap L between the adjacent Xe excimer lamp 2 and the Xe excimer lamp 2 was about 10 mm. The width D of the Xe excimer lamp 2 is about 17 mm.

  The power source of the Xe excimer lamp 2 was turned on, and irradiation of ultraviolet rays by the Xe excimer lamp 2 was started for each of the test pieces A to E. After 30 minutes from the start of ultraviolet irradiation, the degree of decoloration of each of the test pieces A to E after 1 hour and 2 hours was evaluated. The results of the test pieces A to E are shown in FIGS. 2 to 6 also show a photograph of the state of the test piece before irradiation with ultraviolet rays for comparison.

  As shown in FIGS. 2 to 6, it was found that decolorization of the test piece started after about 30 minutes from the start of irradiation with ultraviolet rays. Then, after about 2 hours have passed since the start of the ultraviolet irradiation, it is confirmed that in the portion of the test piece 4 located immediately below the Xe excimer lamp 2, the blue-blue color is almost eliminated and the color is decolored. It was. Further, at this time, it was recognized that the undyed yarn was fading (fading) on the back side (lining) of the test piece as compared with the test piece before being irradiated with ultraviolet rays. That is, it was recognized that the color of the lining of the denim fabric was slightly changed to light yellow.

(Decolorization mechanism)
The following two actions of the organic substance decomposition action and the oxidative decomposition action are considered to promote the decolorization of the test piece (denim fabric) with the irradiation time of ultraviolet rays. First, the denim fabric of a test piece is a twill weave of dyed warp and undyed weft, and indigo is used as a dye for the warp. The indigo is represented by the following structural formula.

  In general, the bond energy of a carbon-carbon double bond (C═C) is about 606 kJ / mol (about 145 kcal / mol), whereas the energy of ultraviolet light having a wavelength of 172 nm is about 695 kJ / mol (about 166 kJ / mol). .2 kcal / mol), and the energy of ultraviolet rays is higher than the binding energy of carbon-carbon double bonds. Therefore, when the denim fabric is irradiated with ultraviolet rays, the carbon-carbon double bond is cut by the energy of the ultraviolet rays. As a result, it is considered that indigo is decomposed and decolorization is promoted (organic matter decomposition action). Indigo is considered to break the double bond at the center of the above structural formula by ultraviolet rays.

  Further, when light having a wavelength of 220 nm or less is irradiated in the atmosphere, water vapor contained in the air in the optical path is activated by the energy of the light, and ozone and active oxygen are generated. For this reason, when the denim fabric is irradiated with ultraviolet rays, ozone and active oxygen are generated in the vicinity of the denim fabric. As a result, it is considered that indigo is oxidatively decomposed by generated ozone and active oxygen, and decolorization is promoted (oxidative decomposition action). In particular, by irradiating the denim fabric with ultraviolet light in the vicinity of the denim fabric with water vapor or mist generated in advance, more water vapor etc. is activated and ozone and active oxygen are efficiently used. Can be generated.

  Thus, it is considered that the indigo decomposed by the organic substance decomposition action or the oxidative decomposition action remains in the fiber product with the carbon-carbon double bond broken. Therefore, decolorization of textiles with ultraviolet rays eliminates the need for treatment of chemicals (waste liquids) after decoloring, compared with the case of decoloring textiles with chemicals, etc. Can do. That is, environmentally friendly decolorization can be performed.

As shown in FIG. 7, when attention is paid to one Xe excimer lamp 2, in the test piece 4, the distance r ₀ between the portion of the test piece 4 located immediately below the Xe excimer lamp 2 and the Xe excimer lamp 2 is The shortest. Then, the distance r _i (i = 1, 2, 3...) Between the Xe excimer lamp 2 and the test piece 4 increases as the distance from the portion immediately below the test piece 4 increases. Therefore, the intensity of the ultraviolet rays actually irradiated to the test piece 4 is the strongest in the portion of the test piece 4 located immediately below the Xe excimer lamp 2 (intensity I ₀ ), and away from the portion immediately below the test piece 4. Accordingly, the intensity of the ultraviolet light gradually decreases (intensity I _i ).

  As a result, the portion of the test piece 4 located immediately below the Xe excimer lamp 2 is most strongly decolored, and the degree of decoloration decreases as the distance from the portion immediately below the test piece 4 increases. As a result, it is possible to bring out a natural gradation of decoloring by irradiating the test piece (textile product) with ultraviolet rays only once.

(Decoloration of actual textile products)
Next, jeans are given as an example of an actual textile product, and the decoloring method will be specifically described. In jeans that have been worn out naturally, parts that rub well are likely to be discolored. As shown in FIG. 8, on the front side of the jeans 6, the portion 6 a that can be wrinkled by bending and stretching the base portion of the thigh and the portion 6 b from the thigh to the knee are easily decolorized. On the other hand, as shown in FIG. 9, on the rear side of the jeans 6, the hip portion 6 c and the wrinkled portion 6 d can be easily discolored by bending and stretching the knee.

  Therefore, first, a model having irregularities corresponding to the heels of the jeans is attached to the jeans. The Xe excimer lamp 2 is scanned with respect to the jeans 6 at a predetermined position (height) as shown in FIG. At this time, as shown in FIG. 11, the Xe excimer lamp 2 and the denim fabric 7 are relatively close to each other at the portion where the denim fabric 7 of the jeans 6 is a convex portion 7 a, so that the intensity of ultraviolet rays is relatively low. Will become stronger and promote decolorization. On the other hand, in the portion where the denim fabric 7 is a concave portion 7b, the Xe excimer lamp 2 and the denim fabric 7 are relatively moved away, so that the intensity of ultraviolet rays is relatively weak and the degree of promotion of decolorization is weak. Will be.

  Moreover, in the part (area | region) from the convex-shaped part 7a of the denim fabric 6 to the concave-shaped part 7b, the distance of Xe excimer lamp 2 and the denim fabric 7 changes gradually. Will be obtained. Thus, natural decoloring corresponding to actual wrinkles can be performed on the jeans 6 by scanning with the Xe excimer lamp 2.

  The UV irradiation conditions are based on the results obtained from the basic evaluation described above, and the layout, irradiation time, intensity, etc. of the Xe excimer lamp are determined so that desired decolorization can be performed according to the user's needs. Will be.

  In addition to the above-described decolorization method, the jeans may be decolored by irradiating ultraviolet rays using a predetermined masking member. For example, as shown in FIG. 12, first, a masking member 8 having an opening 8a corresponding to the convex portion of the ridge is prepared. Next, the masking member 8 is arranged at a predetermined position corresponding to the heel with respect to the jeans 6. Then, by scanning the Xe excimer lamp 2 in this state, the part corresponding to the convex shape of the heel of the jeans 6 is decolored by the ultraviolet rays that have passed through the opening 8a.

  Further, as shown in FIG. 13, in addition to the opening 10a corresponding to the convex portion of the heel, a masking member 10 having an opening 10b corresponding to the portion from the thigh to the knee is prepared as a masking member. Then, the Xe excimer lamp 2 may be scanned. In this case, the portion of the jeans 6 from the thigh to the knee is decolored by the ultraviolet rays that have passed through the opening 10b.

(Thread discoloration / fading)
In the section on basic evaluation, it was stated that the undyed yarn produced was faded on the denim fabric lining of the specimen. Here, a method for fading (fading) the yarn itself will be described.

  As described above, the denim fabric is a twill weave of warp yarn dyed by indigo and generated weft yarn not dyed, and the material is cotton. That is, the denim fabric is formed of warp and weft of vegetable fibers. The reason why the generated weft is discolored by irradiating with ultraviolet rays is considered to be because the organic matter constituting the plant fiber is decomposed.

  Therefore, an example of a technique for fading the yarn based on the knowledge will be described. FIG. 14 shows a thread fading device 11. In the fading device 11, a quartz tube 14 through which a thread 16 is inserted is provided in a predetermined housing 12. A plurality of Xe excimer lamps 2 are respectively attached above and below the quartz tube 14.

  The thread 16 is inserted into the quartz tube 14, the Xe excimer lamp 2 is turned on, and the thread 16 is irradiated with ultraviolet rays emitted from the Xe excimer lamp 2 while pulling the thread 16 from one side to the other. Is decomposed, and the yarn 16 is discolored (discolored). As the irradiation condition, an appropriate condition is set in consideration of the nature of the organic matter constituting the yarn 16 and the degree of fading.

  Thus, the produced yarn is faded, and the textile product is produced using the faded yarn, so that the textile product can have a natural used feeling at the time of production. The above-described yarn fading device 11 can be used for decoloring and fading of dyed yarn in addition to the produced yarn.

(Pigmenting of pigment)
Among textile products, there are textile products dyed with pigments. A pigment is a pigment that is insoluble in water and does not have an affinity for fibers. Therefore, the pigment does not diffuse into the inside of the fiber, but is fixed to the surface of the fiber by a resin component called a binder in a state of being physically attached to the surface of the fiber. Here, a description will be given of a decoloration evaluation by a Xe excimer lamp performed on one of the fiber products dyed with such a pigment and the result thereof.

  First, a fabric dyed pink beige was prepared as a test piece dyed with a pigment, and the fabric was irradiated with ultraviolet rays with a Xe excimer lamp under substantially the same conditions as in the basic evaluation described above. The result of the test piece is shown in FIG. In FIG. 15, for comparison, a photograph of the state of the test piece before irradiation with ultraviolet rays and an image diagram based on the photograph of the state of the test piece after irradiation are also shown.

  As shown in FIG. 15, it was confirmed that the test piece was partially decolored corresponding to the position of the Xe excimer lamp after being irradiated with ultraviolet rays for about 5 minutes. Further, as a test piece, in addition to the test piece dyed pink beige, the same evaluation was performed on the test piece dyed gray or beige, and decolorization progressed in the portion irradiated with ultraviolet rays. It was confirmed. Similarly to the decolorization of the dye, the decolorization of the pigment is considered that a specific chemical bond of the substance constituting the pigment is broken by ultraviolet rays.

(Decolorization of reactive dyeing)
Moreover, in the textile product, there is a textile product dyed by reactive dyeing. The reactive dyeing is a kind of dyeing method in which a yarn is colored by chemically reacting the fiber and dye of the yarn and chemically bonding the dye to the fiber. Here, a description will be given of a decoloration evaluation by a Xe excimer lamp performed on one of the fiber products dyed by such reactive dyeing and the result thereof.

  First, as a test piece dyed by reactive dyeing, a fabric dyed pink was prepared, and the fabric was irradiated with ultraviolet rays with a Xe excimer lamp under substantially the same conditions as in the basic evaluation described above. In particular, in this case, irradiation was performed in a state where the lower quarter of the fabric was masked with another fabric. The result of the test piece is shown in FIG. In FIG. 16, for comparison, a photograph of the state of the test piece before irradiation with ultraviolet rays and an image diagram based on the photograph of the state of the test piece after irradiation are also shown.

  As shown in FIG. 16, it was confirmed that the test piece was partially decolored corresponding to the position of the Xe excimer lamp after irradiation with ultraviolet rays for about 5 minutes. Moreover, as a test piece, in addition to the test piece dyed pink, the same evaluation was performed on the test piece dyed green, and it was confirmed that decolorization progressed in the portion irradiated with ultraviolet rays. It was. The decolorization of reactive dyeing is considered that the chemical bond between the fiber and the dye is broken by ultraviolet rays.

  In the above-described embodiment, the Xe excimer lamp having a wavelength of 172 nm is described as an example of the ultraviolet lamp. As the ultraviolet lamp, a light source capable of emitting light having a wavelength of about 220 nm or less is preferable. That is, the light source emits light having a wavelength higher than the chemical bond energy of the substance forming the dye, or light having a wavelength higher than the energy that activates water vapor or the like to generate ozone or active oxygen. As long as the light source can be used, it is not limited to the Xe excimer lamp.

Embodiment 2
In the above-described embodiment, the Xe excimer lamp (ultraviolet lamp) is described as an example of the light source that emits ultraviolet rays. Here, a method for decoloring a textile product using an ultraviolet laser oscillator will be described.

  The laser beam is coherent light having a uniform wavelength and phase. For this reason, when the laser beam is directly applied to the textile product, the difference in the degree of decoloration between the portion irradiated with the laser beam and the portion not irradiated with the laser beam is too clear, and the decolorization seen in the natural secondhand feeling. It becomes difficult to obtain gradation.

  Therefore, as shown in FIG. 17, when an ultraviolet laser oscillator is applied as the light source, the light beam of the laser beam 20 emitted from the ultraviolet laser oscillator is generated between the ultraviolet laser oscillator 20 and the textile product (jeans 6). An optical element 24 for spreading is provided. As such an optical element 24, for example, an optical element having a lens shape formed of quartz is conceivable. An optical element in which the transmittance of ultraviolet rays gradually decreases from the center toward the outer periphery can be considered.

  By disposing such an optical element 24 in the optical path of the laser beam 22 and gradually spreading the beam of the laser beam, a distribution occurs in the intensity of the laser beam applied to the textile product, and a more natural gradation of decolorization is achieved. Obtainable.

  The embodiment disclosed this time is an example, and the present invention is not limited to this. The present invention is defined by the terms of the claims, rather than the scope described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

In the textile product decoloring method which concerns on Embodiment 1 of this invention, it is a perspective view which shows the arrangement | positioning relationship between the Xe excimer lamp and test piece for demonstrating basic evaluation. In the same embodiment, it is the 1st figure containing the photograph of a test piece which shows the result of basic evaluation. In the same embodiment, it is the 2nd figure containing the photograph of a test piece which shows the result of basic evaluation. In the same embodiment, it is the 3rd figure containing the photograph of a test piece which shows the result of basic evaluation. In the same embodiment, it is the 4th figure containing the photograph of a test piece which shows the result of basic evaluation. In the same embodiment, it is the 5th figure containing the photograph of a test piece which shows the result of basic evaluation. In the same embodiment, it is a figure which shows the positional relationship of a Xe excimer lamp and denim material for demonstrating gradation of decoloring. In the same embodiment, it is the 1st figure which shows the decoloring part in actual jeans. In the same embodiment, it is the 2nd figure which shows the decoloring part in actual jeans. In the embodiment, it is a perspective view which shows an example of the actual decoloring method of jeans. In the embodiment, it is a partial side view for explaining decolorization of a heel portion in jeans. In the same embodiment, it is a perspective view which shows the other example of the actual decoloring method of jeans. In the same embodiment, it is a perspective view which shows the further another example of the actual decoloring method of jeans. In the same embodiment, it is a perspective view which shows an example of the discoloration method of a thread | yarn. In the same embodiment, it is a figure which shows the result of the decoloring evaluation of the fiber dye | stained with the pigment. In the same embodiment, it is a figure which shows the result of the decoloring evaluation of the fiber dye | stained by reactive dyeing. It is a perspective view which shows an example of the decoloring method of the jeans by the ultraviolet laser based on Embodiment 2 of this invention.

Explanation of symbols

  2 Xe excimer lamp, 4 test pieces, 6 jeans, 6a to 6d part, 7 denim fabric, 7a convex part, 7b concave part, 8, 9 masking member, 8a, 10a opening, 11 thread fading device, 12 housing, 14 quartz tube, 16 threads, 20 laser oscillator, 22, 26 laser beam, 24 optical elements.

Claims (7)

  A method for decoloring a fiber, comprising irradiating a dyed fiber with predetermined light in an ultraviolet region.   The method according to claim 1, wherein the dyed fiber includes a denim fabric dyed with indigo as the dye.   The fiber decoloring method according to claim 1, wherein an ultraviolet lamp or an ultraviolet laser oscillator is used as the light source of the predetermined light. Using an ultraviolet laser oscillator as the light source,
The fiber decoloring method according to claim 3, wherein a predetermined optical element that expands a light beam of a laser beam emitted from the ultraviolet laser oscillator is disposed between the ultraviolet laser oscillator and the fiber.   A method for fading a fiber, comprising a step of irradiating the fiber with predetermined light in an ultraviolet region.   6. The method for fading a fiber according to claim 5, wherein the fiber includes a formed fiber.   The method for fading a fiber according to claim 5 or 6, wherein an ultraviolet lamp or an ultraviolet laser oscillator is used as the light source of the predetermined light.