JPH0274687A - Decoloring promoter for bleach processing - Google Patents

Abstract

PURPOSE:To finish fabric in color tone of high commercial value without damaging cloth by adding a decoloring promoter such as metallic oxide or active carbon to a bleaching bath containing an oxidizing agent and subjecting indigo dyed fabric to bleach processing. CONSTITUTION:In decoloring indigo dyed fabric (e.g., blue jeans) in a treating solution containing a hypochlorite, bromine-based oxidizing agent, etc., a decoloring promoter selected from a water-insoluble metallic oxide (e.g., nickel oxide or titanium oxide), active carbon, zeolite, etc., is added to the solution and the fabric is subjected to bleach processing to finish a product having clarity and high commercial value in a short time without damaging cloth.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a bleaching process (decolorization process) performed on indigo-dyed articles such as blue jeans for the purpose of imparting fashionability, etc. This invention relates to a decolorization accelerator used in.

(Prior Art and Problems to be Solved by the Invention) In recent years, in the processing of blue jeans, pleating has become one of the extremely important processing steps in order to meet the various fashion demands of users. This bleaching process for blue jeans takes advantage of the property of the indigo dye used during dyeing, which turns into isatin with an oxidizing agent and disappears. Conventionally, halogen-based oxidizing agents such as sodium hypochlorite have been used as oxidizing agents for this purpose.

However, if a treatment with a strong degree of decolorization is performed using a halogen-based oxidizing agent such as sodium hypochlorite, as is commonly done in the bleaching process of blue jeans, a large amount of oxidizing agent is used and the processing time is delayed. In order to
In the reduction process after oxidation treatment, the amount of reducing agent used increases, the working environment deteriorates, the tear strength of the product decreases due to deterioration of the blue jeans fibers undergoing treatment, and furthermore, the color of the product after treatment deteriorates. (Problems have been pointed out, such as the need for a post-treatment process using an oxidizing agent such as sodium peroxocarbonate to obtain a clear pale blue color. There is a need to develop technology for bleaching.

[Structure of the Invention] (Means and Effects for Solving the Problems) Therefore, as a result of extensive research into pleat processing methods that solve the above-mentioned problems, the inventors of the present invention have developed blue jeans using a halogen-based oxidizing agent. When performing bleaching processing such as nickel oxide, titanium oxide, etc., a decolorization accelerator containing at least one selected from the group consisting of water-insoluble metal oxides, activated carbon, and zeolites can be used to remove the oxidizing agent. It has been found that the amount used can be reduced, the processing time can be shortened, and the degree of decolorization can be improved, and furthermore, good results can be obtained in the tear strength test of blue jeans products. In addition, it is possible to decolorize indigo-dyed objects to a clear light blue color without the need for post-treatment using sodium chloride carbonate, etc., making it possible to perform a process that is useful for fashion in a step-by-step process. They have discovered that this is possible and have completed the present invention. Further, the decolorization accelerator of the present invention can shorten the treatment time even in treatment using an oxidizing agent such as hydrogen peroxide or sodium peroxocarbonate.

The decolorization accelerator of the present invention contains at least one of a water-insoluble metal oxide, activated carbon, and zeolite. Water-insoluble metal oxides include nickel oxide,
Examples of water-insoluble metal oxides include titanium oxide and silver oxide, but the metals in water-insoluble metal oxides are often heavy metals (because of toxicity problems, nickel oxide and titanium oxide are used as water-insoluble metal oxides in the present invention). etc. are preferred.

The dosage form of the decolorization accelerator in the present invention can be appropriately selected from either a powder form or a molded product such as a granular or lump-like product formed by adding a molding binder. When the decolorization accelerator of the present invention is used as a molded preparation, the decolorization accelerator component is preferably contained in the formulation in an amount of 10% by weight or more, more preferably 30% by weight or more. If the concentration of the decolorization accelerator component in the above formulation is low, it is undesirable because it is difficult to exhibit the decolorization accelerating effect with a small amount. Further, as the binder, starch, carboxymethoxycellulose, cement, clay, etc. can be used at a concentration of 1 to 70% by weight, preferably 5 to 50% by weight, most preferably 5 to 30% by weight of the total components. .

Examples of halogen-based oxidizing agents to which the decolorization accelerator of the present invention can be applied include sodium hypochlorite, chlorine-based oxidizing agents such as bleaching powder, sodium bromate, potassium bromate, sodium bromite, and bromite. Mention may be made of brominated oxidizing agents such as potassium, sodium hypobromite, potassium hypobromite, etc., as well as mixtures of chlorinated and brominated oxidizing agents. Further, even when the decolorization accelerator of the present invention is used in combination with an oxidizing agent such as sodium peroxocarbonate or hydrogen peroxide, it promotes the effects of those oxidizing agents and enables bleaching in a short time.

When bleaching an indigo-dyed object using the decolorization accelerator of the present invention, the decolorization accelerator of the present invention is added to a bleaching solution containing a halogen-based oxidizing agent.

The method of addition in this case is not particularly limited, and may include a method of coexisting in a bleaching solution to treat the dyed object, a method of adding the indigo to a tower or a water tank filled with the decolorization accelerator for bleaching of the present invention, and a method of adding indigo to the bleaching solution. It is possible to adopt a method in which the bleaching solution is circulated between the dyed material and the processing equipment using a pump or the like.

In addition, when using a bromine-based oxidizing agent, the decolorization accelerator of the present invention is pre-impregnated with the bromine-based oxidizing agent, and the bleaching process is carried out by bringing this into contact with the indigo dyed object in a bleaching solution. A method of doing this can be adopted.

The amount of the bleaching accelerator used for bleaching of the present invention is preferably in the range of 0.1g/Q to 30g/I2 relative to the bleaching solution.It is effective when the amount of the bleaching accelerator used is lower than 0.1g/I2. It is preferable because the amount is low (and the amount used is 3
Even if it exceeds 0 g/Q, the decolorization promotion effect will not be improved compared to 30 g/β, so it is not preferable from the point of view of cost etc. The above concentration range is more preferably 1 to 20 g/R,
5 to 15 g/ff is most preferred.

As the processing conditions for bleaching an indigo dyed object using a halogen-based oxidizing agent and the decolorization accelerator of the present invention, it is preferable to carry out the processing at a processing temperature of 20 to 70°C for 10 to 60 minutes. The above reaction conditions are 1 at 30-60°C.
More preferably 5 to 40 minutes, 15 to 40 minutes at 40 to 60°C.
Most preferred is 30 minutes.

Further, various additives used in ordinary bleaching solutions may be added to the bleaching solution to which the decolorization accelerator of the present invention is added. For example, 0.01 to 0.5% of a chelating agent such as sodium ethylenediaminediacetate or sodium ethylenediaminetetraacetate, preferably 0.05%
It can be added to the bleaching solution at a concentration of ~0.1%.

The treatment method for carrying out the bunoch processing of an indigo-dyed object using the treatment agent of the present invention is not limited in any way, and includes the conventional method of using an ocher, and the method of impregnating various oxidizing agents in the ower. Methods used in conventional bleaching processes, such as the chemical stone method, which involves the presence of porous solids such as pumice, and the immersion method, which involves soaking in a treatment solution. Can be adopted.

Further, when bleaching is performed using the treatment agent of the present invention, the good results aimed at by the present invention can be obtained by performing pre-treatments such as water washing and stone washing, which are carried out in normal bleaching.

After the indigo-dyed material is subjected to the bnooch processing using the treatment agent of the present invention, under the same conditions as normal bleach processing,
Treatment with reducing agent, rinsing, cleaning with detergent,
Appropriate post-treatment in combination with softening treatment and the like can be carried out, followed by a drying process.

By using the decolorization accelerator for bleach processing of the present invention together with a halogen-based oxidizing agent such as sodium hypochlorite or an oxidizing agent such as sodium chloride carbonate,
It becomes possible to shorten the processing time in bleach processing, and when using a halogen-based oxidizing agent, it becomes possible to perform processing with a high degree of bleaching to a light blue color without the need for post-treatment with sodium peroxo carbonate, etc. At the same time, the tear strength of the indigo-dyed product after bleaching is also good. Furthermore, the color tone of the dyed object after treatment becomes an extremely clear light blue color, so that a fashionable product can be obtained.

The effect of the decolorization accelerator for bleaching according to the present invention as described above is due to the catalytic effect on the halogen-based oxidizing agent. It is a new discovery in this technical field that it has become possible to bleach a dyed material to a clear light blue color, and therefore, the present invention can perform a useful function in bleaching an indigo-dyed material. A processing agent has been discovered, and its industrial utility is great.

(Example) Next, the present invention will be explained by giving specific examples, but the present invention is not limited to these examples in any way. ”.

Furthermore, the method for testing the tear strength of the product according to the present invention is as follows.

A test piece of an indigo-dyed product that has been subjected to bleach processing is post-treated with a reducing agent and washed with water, and after further drying,
The tear strength was measured by the method of JIS L 1096 [3 (Penschlum method).

1~. 3.1-3 A test piece of indigo-dyed blue jeans (tear strength: about 5 kg) cut into a size of 10 cm x 10 cm was subjected to the following treatment.

As a bleaching solution, 2ONl of a sodium hypochlorite aqueous solution (available chlorine amount: 12%) was taken, and water was added to the solution to make a total volume of II2, which was used as a treatment solution for a comparative example. Furthermore, nickel oxide, titanium oxide, or silver oxide powder was added to this sodium hypochlorite solution as a decolorization accelerator for bleaching according to the present invention at 0.05 g/I2.0, respectively.
These were added to give concentrations of 1 g/β, 20 g/P, and 30 g/12, and used as treatment solutions for Examples 1-1 to 3-4.

The bleaching solutions of various compositions mentioned above were placed in a glass beaker and the temperature of the solution was brought to 50°C, and then a test piece of blue jeans was immersed in the bleaching solution. The time required for the decolorization process was measured and used as the processing time.

The results of the above Examples and Comparative Examples are shown in Tables 1 to 3 below. In the table below, the amount of NaCl20 solution represents the amount (-/flood) of sodium hypochlorite aqueous solution (available chlorine amount 12%) with respect to bleaching solution 1β.

Table = Results of Example 1 and Comparative Examples Table 2: Results of Example 2 = Results of Example 3 Table 4: Results of Example 4 = Results of Example 5 Decolorization for bleach processing of the present invention Granular activated carbon or zeolite as accelerator, 0.05g/12.0.1 each
g/g, lOg/β, 20 g/12.30 g/
Blue jeans were bleached using the bleaching solution under the same conditions as in Example 1 and the same method, except that the concentration of Q was added. The results are shown in Tables 4 and 5 below.

Examples 6 to 7 Nickel oxide and granular activated carbon were used as bleaching accelerators of the present invention at 0.05 gzl and 0.1 gzl, respectively.
g/g, 10 g/β, 20 g/f2, and sodium hypochlorite 5 ml/β as an oxidizing agent.
and 0.1 g/j of sodium bromate as a brominated oxidizing agent.
Blue jeans were decolorized using the same method as in Example 1, except that the aqueous solution prepared using Example 2 was used as the bleaching solution. The results are shown in Tables 6 and 7 below.

Table 6: Results of Example 6 = Results of Example 7 Using the same test piece as in Example 1, a 20% sodium hypochlorite aqueous solution (available chlorine amount 12%) was taken as a bleaching solution. The test specimen was immersed for 20 minutes at a liquid temperature of 50'C in a solution made by adding water to make lρ.
It was taken out onto a vat after the following treatments.

In addition, sodium bromate Ig is added to granular activated carbon as a decolorization accelerator for bleaching of the present invention, and sodium bromate Ig is used as a bromine-based oxidizing agent.
A second treatment was performed by impregnating 10 g of activated carbon with 2 g of the aqueous solution at a ratio of 2 g of the aqueous solution to 10 g of activated carbon and randomly disposing it on the test piece taken out on the vat.

This test piece had a lightly colored background, and the area impregnated with the brominated oxidizing agent in the second treatment was bleached to pale blue.

Examples 9-l 1 and 4 Using the same test piece as in Example 1, it was treated with 20% of sodium hypochlorite (available chlorine amount: 12%) in the same manner as in Example 1.
ml was taken and water was added to it to make 12.
The first treatment was carried out by soaking for 25 minutes at .degree. C., resulting in a slightly pale blue color.

The test piece that has undergone this first treatment is treated with a reducing agent,
After further washing with water, the following treatment was performed.

That is, log nickel oxide, granular activated carbon, or zeolite was added to a solution containing 5 g/12 sodium chloride carbonate as a decolorization accelerator for bleaching according to the present invention.
A bleaching solution was prepared with a bleaching solution of 0.25%, and the test piece that had been subjected to the first treatment was immersed in this solution, and the second treatment was performed at a solution temperature of 70°C, resulting in a clear light blue color. Comparisons were made of the time required to achieve this and the tear strength of the resulting products. The results are shown in Table 8 below.

Table 8: Results of Examples 9 to 11 and Comparative Example 4 [Effects of the Invention] As detailed above, by using the decolorization accelerator for bleaching of the present invention, the oxidizing agent for indigo-dyed materials such as blue jeans In addition, the resulting product has a clear pale blue color and is of high commercial value.

Claims (1)

[Scope of Claims] 1. A decolorization accelerator for bleaching indigo-dyed materials, which comprises at least one selected from the group consisting of water-insoluble metal oxides, activated carbon, and zeolites. 2. A bleaching method for an indigo-dyed material, which comprises using an oxidizing agent and the decolorization accelerator according to claim 1.