JP2011246837A - Vat dyeing method and vat dyeing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vat dyeing method and a vat dyeing device capable of dyeing appropriately by suppressing the deterioration, deformation and degradation of a dyed object even when a dyed object composed of natural material such as natural leather is vat dyed.SOLUTION: A vat dyeing device 1 of this invention for dyeing a natural leather sheet (dyed object) S composed of natural material using a vat dye comprises a container 2 in which a dyeing liquid L formed by dissolving the vat dye with a reducing agent in a weak alkaline aqueous solution and the natural leather sheet A are placed, and ultrasonic irradiation parts 6 disposed on the wall surfaces of the container 2.

Description

  The present invention relates to a vat dyeing method and vat dyeing device for a dyed article made of a natural material.

  When dyeing indigo etc. on the object to be dyed, the vat dye is reduced with an reducing agent in an alkaline aqueous solution and impregnated with a dyeing solution made into a leuco body, then exposed to air and oxidized. The leuco body in the object to be dyed is dyed by returning it to the original chemical structure (see, for example, Patent Document 1).

JP 2008-121136 A

  However, even if a natural material such as natural leather is dyed by the conventional vat dyeing method, the natural material is altered and deformed. In addition, the flexibility and surface gloss of natural materials are deteriorated, and there is a problem that even if dyed, the dye is immediately peeled off by friction.

  The present invention has been made in view of the above circumstances, and even if a dyed article made of a natural material such as natural leather is vat-dyed, it can be suitably dyed while suppressing deterioration, deformation, and deterioration of the dyed article. It is an object of the present invention to provide a vat dyeing method and vat dyeing device.

The present invention employs the following means in order to solve the above problems.
The vat dyeing method according to the present invention is a vat dyeing method for dyeing an object to be dyed made of a natural material using a vat dye, wherein the vat dye is dissolved together with a reducing agent in a weak alkaline aqueous solution. It is provided with the immersion process which impregnates the said to-be-dyed material with a liquid.

  Moreover, the vat dyeing method according to the present invention is the vat dyeing method, wherein the weak alkaline aqueous solution contains ammonia, sodium carbonate, tetramethylammonium hydroxide or sodium tetraborate as a solute. .

  Moreover, the vat dyeing method according to the present invention is the vat dyeing method, characterized by comprising an irradiation step of irradiating the dyeing liquid with ultrasonic waves at room temperature.

  Further, the vat dyeing method according to the present invention is the vat dyeing method, comprising: a pressure reducing step for reducing the pressure to release air in the article to be dyed; and a pressure applying step for pressurizing the dyeing liquid. It is characterized by.

  Further, the vat dyeing apparatus according to the present invention is a vat dyeing apparatus for dyeing a material to be dyed made of a natural material using a vat dye, and dissolves the vat dye together with a reducing agent in a weak alkaline aqueous solution. And a container in which the dyed liquid and the object to be dyed are mixed.

  The vat dyeing apparatus according to the present invention is the vat dyeing apparatus, wherein the weak alkaline aqueous solution contains ammonia, sodium carbonate, tetramethylammonium hydroxide, or sodium tetraborate as a solute. .

  Moreover, the vat dyeing apparatus according to the present invention is the vat dyeing apparatus, comprising an ultrasonic irradiation unit that irradiates the dye liquid with ultrasonic waves at room temperature.

  Further, the vat dyeing apparatus according to the present invention is the vat dyeing apparatus, comprising a decompression unit that depressurizes the inside of the container, and a pressurization unit that pressurizes the inside of the container. To do.

  According to the present invention, even when a dyed material made of a natural material such as natural leather is vat-dyed, suitable dyeing can be performed while suppressing alteration, deformation, and deterioration of the dyed material.

It is a schematic diagram which shows the vat dyeing apparatus which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the vat dyeing method which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the vat dyeing apparatus which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the vat dyeing method which concerns on the 2nd Embodiment of this invention. It is an electron micrograph which shows the state of each dyeing | staining surface of the natural leather in the vat dyeing method which concerns on each embodiment of this invention, and the conventional method. It is an electron micrograph which shows the state of the dyeing | staining surface of the natural leather in the vat dyeing method which concerns on each embodiment of this invention. It is an electron micrograph which shows the state of each dyeing | staining surface of the silk in the vat dyeing method which concerns on each embodiment of this invention, and the conventional method. It is a photograph which shows the state before the friction test of each dyeing | staining surface of the natural leather in the vat dyeing method which concerns on each embodiment of this invention, and the conventional method. It is a photograph which shows the state before the friction test of each dyeing | staining surface of a natural leather and the undyed surface in the vat dyeing method which concerns on each embodiment of this invention, and the conventional method. It is a photograph which shows the state after the friction test of each dyeing | staining surface of the natural leather in the vat dyeing method which concerns on each embodiment of this invention, and the conventional method. It is a photograph which shows the state after the friction test of each dyeing | staining surface of the natural leather and the undyed surface in the vat dyeing method which concerns on each embodiment of this invention, and the conventional method. It is a photograph which shows the state before and behind the friction test of each dyeing | staining surface of the natural leather in the vat dyeing method which concerns on the 1st Embodiment of this invention. It is a photograph which shows the state before and after the friction test of each dyeing | staining surface of the natural leather in the vat dyeing method which concerns on the 2nd Embodiment of this invention. It is a photograph which shows the state before and after the friction test of each dyeing | staining surface of the natural leather in the conventional vat dyeing method. It is a graph which shows the lightness state of the surface before and after the friction test after veneering dyeing | staining natural leather with the vat dyeing method which concerns on each embodiment of this invention, and the conventional method.

(First embodiment)
A first embodiment according to the present invention will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the vat dyeing apparatus 1 according to the present embodiment is mixed with a dyeing solution L in which a vat dye is dissolved together with a reducing agent in a weak alkaline aqueous solution and a natural leather sheet (material to be dyed) S. The container 2 is provided.

  The container 2 is provided with a lid 3 and a drain port 5, and a plurality of ultrasonic irradiation units 6 are provided on the wall surface. As the reducing agent, for example, sodium hydrosulfite is used as in the known method. The weak alkaline aqueous solution preferably contains ammonia, sodium carbonate, tetramethylammonium hydroxide or sodium tetraborate as a solute as a reducing aid for exerting the reducing properties of sodium hydrosulfite.

  The vat dyes consist of 6.6'-dibromoindigo (ancient purple, shell purple, Chilean pearl) or indigo.

  Next, the vat dyeing method according to the present embodiment will be described together with the operation of the vat dyeing apparatus 1. As shown in FIG. 2, the vat dyeing method according to the present embodiment includes an immersion step (S11), an irradiation step (S12), and an oxidation step (S13).

  In the dipping step (S11), a dye solution L in which a vat dye is dissolved together with a reducing agent of hydrosulfite sodium in a weak alkaline aqueous solution is placed in the container 2 together with the natural leather sheet S, and the natural leather sheet S is formed at room temperature. Impregnation with staining solution L.

  In the irradiation step (S12), ultrasonic waves of a predetermined intensity are irradiated from the ultrasonic irradiation unit 6 for a predetermined time at room temperature. As a result, the air trapped in the natural leather sheet S is released to the outside, and the dyeing liquid L penetrates into the natural leather sheet S instead.

  In the oxidation step (S13), the natural leather sheet S is taken out of the container 2 and left in the air, or is oxidized by a known method such as immersion in an oxidizing solution such as hydrogen peroxide. Thus, the natural leather sheet S is colored.

  According to the vat dyeing apparatus 1 and the vat dyeing method, since a weak alkaline aqueous solution is used instead of using a strong alkaline aqueous solution such as caustic soda as in the past, deformation and alteration of natural materials such as the natural leather sheet S are performed. Deterioration can be suitably suppressed, and building dyeing can be suitably performed.

  In particular, since the weak alkaline aqueous solution contains ammonia, sodium carbonate, tetramethylammonium hydroxide or sodium tetraborate as a solute as a reducing aid, it can be handled safely.

  Moreover, by irradiating ultrasonic waves from the ultrasonic irradiation unit 6 in the irradiation step (S12), the natural leather sheet S can be vibrated to easily release the internal air to the outside. Therefore, the dyeing liquid L can be easily infiltrated into the gap from which the air has been released.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS.
In addition, the same code | symbol is attached | subjected to the component similar to 1st Embodiment mentioned above, and description is abbreviate | omitted.
The difference between the second embodiment and the first embodiment is that the vat dyeing apparatus 10 according to this embodiment includes a decompression unit 11 and a pressurization unit 12 instead of the ultrasonic irradiation unit 6, and The dyeing and dyeing method includes a pressure reducing step (S22) and a pressurizing step (S23) instead of the irradiation step (S12).

  As shown in FIG. 3, the vat dyeing apparatus 10 includes a container 15 provided with a lid 13 and a drain port 5, a decompression unit 11 that decompresses the inside of the container 15, and a pressurization unit 12 that pressurizes the inside of the container 15. It has. The lid 13 is provided with a sealing packing 16 and a liquid introduction pipe 17 provided with an introduction port 17 </ b> A through which the staining liquid L is introduced and extending to the bottom of the container 15. The liquid introduction pipe 17 is further provided with an on-off valve 18.

  The decompression unit 11 includes a first decompression pipe 11A connected to the lid 13, a first adjustment valve 11B disposed in the middle of the first decompression pipe 11A, a trap part 11C communicated with the first decompression pipe 11A, A second decompression pipe 11D communicated with the trap portion 11C and a vacuum pump (not shown) communicated with the second decompression pipe 11D are provided. The trap portion 11C is provided to alleviate the odor of ammonia when a weak alkaline aqueous solution in which ammonia is dissolved is used as a reducing aid.

  11 C of trap parts are provided with the trap container 11E by which water or weak acidic water SL was distribute | arranged inside so that space part SP might be formed in the upper part. A plurality of holes 11F are provided at the tip of the first decompression pipe 11A on the trap part 11C side, and are immersed in water or weakly acidic water SL. The tip of the second decompression pipe 11D on the trap part 11C side is opened in the space part SP. In the case of a reducing aid using sodium carbonate or the like, the trap part 11C may not be provided, and the first decompression pipe 11A and the second decompression pipe 11D may be directly connected.

  The pressurizing unit 12 includes a pressurizing pipe 12A having one end connected to the lid 13 and the other end being opened to the atmosphere, and a second adjustment valve 12B disposed in the middle of the pressurizing pipe 12A.

  Next, the vat dyeing method according to the present embodiment will be described together with the operation of the vat dyeing apparatus 10. As shown in FIG. 4, the vat dyeing method according to the present embodiment includes a decompression step (S21), an immersion step (S22), a pressurization step (S23), and an oxidation step (S24).

  In the decompression step (S12), the natural leather sheet S is introduced into the container 15, the lid 13 is closed and the container 15 is sealed, and then the first regulating valve 11B is closed with the on-off valve 18 and the second regulating valve 12B closed. And the vacuum pump is driven to depressurize the container 15 to a predetermined pressure. At this time, the air trapped in the natural leather sheet S is released to the outside through the first decompression pipe 11A. After the predetermined time has elapsed, the first adjustment valve 11B is closed and the vacuum pump is stopped.

  In the dipping step (S22), the on-off valve 18 is opened and the dyeing solution L is put into the container 15 through the liquid introduction pipe 17 while taking care not to let air enter the container 15, and the natural leather sheet S is placed at room temperature. Impregnation with staining solution L.

  In the pressurizing step (S23), the second regulating valve 12B is opened with the on-off valve 18 and the first regulating valve 11B closed, and external air is introduced into the container 15 through the pressurized pipe 12A. The internal pressure of 15 is returned to atmospheric pressure. At this time, the dyeing liquid L soaks into the natural leather sheet S.

  The oxidation step (S24) is the same as the oxidation step (S13) in the vat dyeing method according to the first embodiment. Thus, the natural leather sheet S is colored.

  According to the vat dyeing apparatus 10 and the vat dyeing method, as in the first embodiment, deformation, alteration, and deterioration of a natural material such as the natural leather sheet S can be suitably suppressed. Can be dyed in the building.

  In particular, the vat dyeing apparatus 10 includes a decompression unit 11 and a pressurization unit 12 and varies the pressure in the decompression step (S21) and the pressurization step (S23) in the vat dyeing method. Can be more easily released to the outside, and the natural leather sheet S can be reliably impregnated with the dyeing liquid L.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the said 2nd Embodiment, although the process is advanced in order of a pressure reduction process (S21) and an immersion process (S22), even if it transfers to a pressure reduction process after performing not only this but an immersion process previously. Good. That is, the inside of the container 15 may be decompressed after the natural leather sheet S is impregnated with the dyeing liquid L.

  In addition, it is said that a weak alkaline aqueous solution containing ammonia, sodium carbonate, tetramethylammonium hydroxide, or sodium tetraborate as a solute as a reducing aid is used, but not limited thereto, sodium hydrogen carbonate, potassium carbonate, or ethanol Organic amines such as amines may be used as the solute. The reducing agent is not limited to hydrosulfite sodium. Further, the vat dye is not limited to 6.6'-dibromoindigo (ancient purple, shell purple, Chilean pearl) or indigo. The natural material is not limited to natural leather and may be silk.

  In order to confirm the dyeing state, the surface state when natural leather and silk are dyed using a weakly alkaline aqueous solution containing ammonia or sodium carbonate is generally used as a reducing aid in the case of no dyeing. It compared with the case of the strong alkali aqueous solution containing the sodium hydroxide currently used. A photograph of the surface by an electron microscope (SEM) is shown in FIG. During observation, platinum palladium was deposited on the sample.

  In the case of natural leather, fine fibers are observed on the surface as shown in FIG. On the other hand, when ammonia was used, as shown in FIG. 5B, a slightly swollen state was observed, but the state was almost the same as that without staining. Further, when sodium carbonate is used, as shown in FIG. 5 (c), a part of the surface is melted and a part of the same fiber as that of undyed is observed. In other words, a part of the surface is melted, but a part is unchanged. On the other hand, in the case of sodium hydroxide, as shown in FIG. 5 (d), the entire surface was dissolved and became a smooth surface.

  That is, when dyeing was actually performed, it was ammonia and sodium carbonate that was almost the same as the non-dyed material that could maintain the flexibility that was almost the same as that without dyeing. On the other hand, sodium hydroxide caused severe hardening and shrinkage.

  In the method according to the second embodiment, natural leather was dyed using a weak alkaline aqueous solution containing tetramethylammonium hydroxide or sodium tetraborate as a solute as a reducing aid. An electron microscope (SEM) photograph of the surface state at this time is shown in FIG. In the case of tetramethylammonium hydroxide, some surface dissolution was seen when viewing FIG. 6 (a), but there was no problem with the actual hand. In the case of sodium tetraborate, it was possible to dye without heating as shown in FIG. 6B by heating. These reduction aids can be used instead of odorous ammonia when the vat dyeing apparatus does not include the trap portion 11C in the second embodiment.

  The same dyeing was tried for silk instead of natural leather. The results are shown in FIG. In the non-dyed state, as shown in FIG. 7A, fibers on the silk surface are observed, and in the case of ammonia, as shown in FIG. In the case of sodium carbonate, as shown in FIG. 7C, there is almost no difference from the case of no staining. On the other hand, in the case of sodium hydroxide, it can be observed that the surface of the fiber flutters and deteriorates as shown in FIG.

  That is, when a strong alkaline aqueous solution is used in the current method for preparing a dyeing solution, the silk fibers are deteriorated. However, when a weak alkaline aqueous solution was used, no deterioration was observed and the gloss of silk was maintained.

  Next, when the vat dyeing method (ultrasonic wave) in the first embodiment and the vat dyeing method (reduced pressure) in the second embodiment are each repeated five times, and the natural leather sheet S is dyed, respectively, A test for comparing the degree of dyeing was carried out with the conventional case of dyeing in the state of being immersed in the dyeing liquid L five times. Here, in the method shown in JIS L 0805, a friction fastness test was performed by comparing with a gray scale for contamination by the cork method, and the surface condition before and after friction was observed. Observation was made by measuring the change in the absorption spectrum of reflected light by attaching an attached integrating sphere to an ultraviolet-visible spectrophotometer (SHIMAZU UV-2550 type) manufactured by Shimadzu Corporation. In addition, a colorimeter (KONICA MINOLUTA Color Reader CR-13 type) manufactured by Konica Minolta Sensing Co., Ltd. was also used. The results are shown in FIGS.

  FIG. 8 shows absorption spectra of the natural leather sheet S dyed by the vat dyeing method in the first embodiment, the vat dyeing method in the second embodiment, and the conventional vat dyeing method, respectively, before the friction test. Indicates. FIG. 9 shows an absorption spectrum when the case before staining is added to FIG.

  FIG. 10 shows absorption spectra after a friction test of a natural leather sheet S dyed by the vat dyeing method in the first embodiment, the vat dyeing method in the second embodiment, and the conventional vat dyeing method. Indicates. FIG. 11 shows an absorption spectrum when the case before dyeing is added to FIG.

  FIG. 12 shows a state in which absorption spectra of the natural leather sheet S dyed by the vat dyeing method in the first embodiment are compared before and after the friction test. FIG. 13 shows a state in which absorption spectra before and after the friction test of the natural leather sheet S dyed by the vat dyeing method in the second embodiment are compared. FIG. 14 shows a state in which absorption spectra of natural leather sheet S dyed by a conventional vat dyeing method are compared before and after the friction test. FIG. 15 shows a state in which the lightness before and after the friction test of the natural leather sheet S dyed by each vat dyeing method is compared.

  Prior to the friction test, as shown in each figure, it can be seen that the same density can be obtained by any method. However, when comparing after the friction test, it was found that the vat dyeing method according to the second embodiment has the least color fading, while the conventional method has the most severe color fading.

DESCRIPTION OF SYMBOLS 1,10 Vat dyeing apparatus 2,15 Container 6 Ultrasonic irradiation part 11 Decompression part 12 Pressurization part

Claims (8)

A vat dyeing method for dyeing an object to be dyed made of natural materials using a vat dye.
A vat dyeing method comprising a dipping step of impregnating the dyed product with a dyeing solution obtained by dissolving the vat dye together with a reducing agent in a weak alkaline aqueous solution.   The vat dyeing method according to claim 1, wherein the weak alkaline aqueous solution contains ammonia, sodium carbonate, tetramethylammonium hydroxide, or sodium tetraborate as a solute.   The vat dyeing method according to claim 1 or 2, further comprising an irradiation step of irradiating the dyeing liquid with ultrasonic waves at room temperature. A depressurization step of depressurizing and releasing the air in the object to be dyed;
A pressurizing step of pressurizing the staining solution;
The vat dyeing method according to any one of claims 1 to 3, further comprising: A vat dyeing apparatus for dyeing dyed articles made of natural materials using vat dyes,
A vat dyeing apparatus comprising a container in which a dyeing solution in which the vat dye is dissolved together with a reducing agent in a weak alkaline aqueous solution and the object to be dyed are mixed.   The vat dyeing apparatus according to claim 5, wherein the weak alkaline aqueous solution contains ammonia, sodium carbonate, tetramethylammonium hydroxide or sodium tetraborate as a solute.   The vat dyeing method according to claim 5, further comprising an ultrasonic irradiation unit that irradiates the staining liquid with ultrasonic waves at room temperature. A decompression section for decompressing the inside of the container;
A pressurizing part for pressurizing the inside of the container;
The vat dyeing apparatus according to any one of claims 5 to 7, further comprising:

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