JPH07197386A - Post-alkali-weight-reducing treatment - Google Patents

Abstract

PURPOSE:To obtain a dyed article free from staining by currying out a post- alkali-weight-reducing treatment of a polyester resin dyed article in the presence of a strongly basic substance and thiourea dioxide. CONSTITUTION:A bath is prepared with a strongly basic substance (e.g. sodium hydroxide) and thiourea dioxide in advance. An article dyed with disperse dyes, especially dyes strongly resistant to alkaline conditions, is treated in the bath e.g. at the bath ratio of 1:20 at 110 deg.C for 30min. In these conditions, a post- alkali-weight-reducing treatment can efficiently be curried out without causing staining at a low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a post-processing method for dyed products, and more particularly to a post-alkaline weight reduction processing method which is a kind of texture processing for dyed polyester fibers.

[0002]

2. Description of the Related Art Conventionally, after a polyester fiber dyeing product, alkali reduction treatment (especially when high-temperature short-time treatment is performed using a reduction treatment accelerator) is easily decomposed when it is dropped into a bath during weight reduction treatment. It was limited to the dyed product dyed with a dye having weak alkali resistance (easy to decompose). When the polyester fiber dyeing product dyed with a dye having a strong alkali resistance was post-alkali weight reduction processed, the dye dropped out in the bath contaminates the fibers present in the bath, resulting in a reduction in the quality of the processed product. Therefore, a dye having a characteristic (for example, fastness) suitable for the purpose cannot be arbitrarily selected, and the selection range must be narrowed. The tendency of contamination becomes more prominent when a weight reduction processing accelerator used for the purpose of hygienic safety and cost reduction is used or when high temperature short time treatment is performed. Therefore, the polyester fiber dyeing product dyed with a limited dye which is less likely to be contaminated has to be subjected to post alkali reduction processing under conditions of low temperature and long time.

[0003]

Contamination at the time of polyester weight reduction processing, especially when a weight reduction processing accelerator is used or when a short-time treatment at high temperature is performed, the dye that has lost fibers in the bath is contaminated. However, the use of chemicals for cost reduction and high temperature short time treatment often result in lowering the quality of the product, but the present invention is contaminated by the falling dye during the weight reduction processing, especially the weight reduction. The purpose is to prevent contamination when a processing accelerator is used or during short-time processing at high temperature.

[0004]

The inventors of the present invention have arrived at the present invention as a result of earnest studies for achieving the above object. That is, the present invention relates to (1) a post-alkaline weight loss processing method characterized by treating a polyester fiber dyeing product in the presence of a strong base substance and thiourea dioxide. Hereinafter, the method of the present invention will be described in detail.

In the method of the present invention, thiourea dioxide is used in combination with the strongly basic substance in the alkaline reduction processing after the polyester fiber dyeing product. As the strong base substance, hydroxides of metals such as caustic soda and caustic potash are used, and these are used alone or in a mixture of two or more kinds and usually in a concentration range of 4 to 20% owf. The amount of thiourea dioxide used is
Usually, the range of 8 to 12 g / L is preferable. If it is below this range, the effect as a reducing agent will not continue, and if it is above this range, the effect as a reducing agent will not change, but the secondary processing will impede weight reduction processing. In the method of the present invention,
First, a treatment bath is prepared by optionally adding a strong base substance, thiourea dioxide and other additives described below, and then the polyester fiber dyeing product to be processed is added to the bath,
The treatment is performed at a normal temperature of 90 to 130 ° C. for about 10 to 120 minutes. The bath ratio is usually in the range of 1: 5 to 1:50. The polyester fibers targeted by the present invention are all polyester fibers including microfibers, new synthetic fibers, and cationic dyeable polyesters. The form of these fibers may be any form such as raw cotton, sliver, yarn, woven fabric, knitted fabric, non-woven fabric and sewn product. In the method of the present invention, in addition to a strong base substance and a reducing agent, a weight reduction processing accelerator and a stain inhibitor can be used in combination. A cationic substance such as an alkylamine quaternary ammonium salt or a cationic activator can be used as the weight reduction processing accelerator. In addition, nonionic activators and anionic activators can be used as antifouling agents.

The amount of the weight-reduction processing accelerator used varies depending on the strength of the effect of the agent, but is preferably in the range of 1 to 5 g / L for the alkylamine quaternary ammonium salt-based weight-reduction processing accelerator. When using the weight-loss processing accelerator, the strong base is efficiently consumed in the bath. That is, it functions to accelerate the hydrolysis rate of the polyester fiber. Therefore, when a promoter is used, it is necessary to reduce the amount of the strong base used to an appropriate amount commensurate with the weight reduction rate. Further, when processing is performed using a weight reduction processing accelerator, a cationic substance (accelerator) may remain on the fiber surface, which may deteriorate various fastnesses, and therefore it is preferable to perform anion reversion. As an example of a method for returning anions, for example, a bath in which an anionic activator is dissolved in water is heated to around 85 ° C. and treated in this bath for several minutes to several tens of minutes. If necessary, a chelating agent, a reducing agent, a chemical for adjusting the pH and the like can be added to this bath.

In the alkali reduction treatment after the present invention, not only the dyed product dyed with a dye having a weak alkali resistance which has been conventionally used, but the conventional method causes the contamination according to JIS L.
It has become possible to target dyes dyed with a large number of highly fast dyes that are worse than 0805 staining gray scale class 2-3. Therefore, the dye is not limited and can be freely selected according to the purpose, and the treatment can be performed at high temperature in a short time. Therefore, it is possible to greatly reduce the cost industrially and simplify the process. The present invention has such an effect, and thus the end use of the product at the yarn-dyed (yarn-dyed) fiber processing plant,
Even if the process conditions at each factory cannot be grasped, it can be widely used as a method for safely enabling high-quality post-alkali weight reduction processing.

[0008]

EXAMPLES The present invention will be described in more detail with reference to the following examples. To determine the contamination of cloth in the examples, the processed cloth and the unprocessed cloth are arranged under a xenon standard light source, and JIS L 0 is used.
805 staining gray scale.

Example 1 Kayaron polyester black TA-SF2
00 (azo disperse dye: manufactured by Nippon Kayaku Co., Ltd.) 4.55%
o. w. f. 5 g of a test cloth was prepared by knitting a polyester new synthetic yarn dyed in 1) and an undyed polyester new synthetic yarn (the same as above) in a border pattern in a ratio of 2: 1. Next, a weight reduction processing bath containing 40 g / L of caustic soda and 10 g / L of thiourea dioxide was placed in a stainless steel pot for high-temperature high-pressure dyeing test at a bath ratio of 1: 2.
100 ml is prepared so as to be 0, and a test cloth is put thereinto and hermetically sealed. Using a mini color dyeing machine (Texam Giken dyeing tester), this sample is heated from 50 ° C. to 110 ° C. in 30 minutes, treated at 110 ° C. for 30 minutes, then cooled and the test cloth is taken out and washed with water. . The test cloth is neutralized to neutrality, washed again with water, and dried.

As Comparative Example 1, the same procedure as in Example 1 was carried out except that thiourea dioxide was not used. After the post-alkali reduction treatment, the mixture was cooled to 80 ° C. and hydrosulfite was added to the bath in an amount of 5 g / Add to the bath so that it becomes L. After treating at the same temperature for 5 minutes, the test cloth is cooled, taken out, and washed with water. The test cloth is neutralized to neutrality, washed again with water, and dried. Determine the contamination of the processed product by the method of the present invention and the processed product of the comparative example obtained as described above,
The results are shown in Table 1.

[0011]

[Table 1]

As is clear from Table 1, the processed product produced by the method of the present invention has markedly better white spot contamination than the comparative example.

Example 2 20 g / L of caustic soda was used, and 3 g / L of neolate NCB (cationic special alkylamine quaternary ammonium salt-based weight reduction accelerator: Nika Kagaku Co., Ltd.) was further added. Other than that, the post-alkali weight reduction processing was performed under the same conditions as in Example 1. Further, in order to remove the cationic substance on the fiber, the following anion return was performed. Vixen AG-25 (special anion-based defixing / anion returning agent: Nika Kagaku Co., Ltd.) 2 g / L, Kayakerator C
Anion return bath containing 0.5 g / L of -1000 (special anionic polycarboxylic acid-based water softener: manufactured by Nippon Kayaku Co., Ltd.) was 100 ml so that the bath ratio was 1:20 with respect to the test cloth.
It is prepared, charged with a test cloth, shaken at 85 ° C. for 20 minutes under normal pressure, taken out, washed with water and dried.

As Comparative Example 2, post-alkali weight reduction processing was carried out in the same manner as in Example 2 except that thiourea dioxide was not used, and then cooled to 80 ° C., and hydrosulfite was added to the bath in an amount of 5 g / What is weighed so as to be L is added to the bath. After treating at the same temperature for 5 minutes, the test cloth is cooled, taken out, and washed with water. The test cloth was neutralized to be neutral, washed again with water, and subjected to anion reversion in the same manner as in Example 2. Contamination of the processed products obtained by the method of the present invention and the processed products of Comparative Examples obtained as described above was determined, and the results are shown in Table 2.

[0015]

[Table 2]

As is clear from Table 2, the processed products of the method of the present invention have improved white field contamination in comparison with the comparative examples.

Example 3 Color Fine AD (Special Anion Activator Pollution Prevention /
Solubilizing agent: manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., and post-alkali weight reduction processing and anion reversion processing were performed in the same manner as in Example 2. The contamination of the obtained treated product was judged to be grade 4.

[0018]

EFFECTS OF THE INVENTION Even a dyed polyester fiber dyed with a high-fastness dye can be subjected to post-alkali weight reduction processing efficiently at low cost without causing contamination. .

Claims (1)

[Claims] 1. A post-alkali weight loss processing method characterized in that a dyed polyester fiber is treated in the presence of a strong base substance and thiourea dioxide.