JPS60252769A - Decoloration method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Chlorhexidine or its salts are widely used as bactericidal disinfectants [2] in medical institutions, etc.;
When cleaning textile products such as curtains, if oxidative bleaching is done with hypochlorite or other oxidative agents, the areas to which chlorhexidine or its salts are attached will be colored yellowish brown, and this coloring will no longer come off with normal cleaning. Major problems have been pointed out.

The present inventors investigated a simple method for decolorizing this coloring, and discovered that it can be easily decolorized by immersing it in a solution containing a halogen and then treating it with a solution containing a reducing agent.

If a textile product processed with chlorhexidine or its salt is colored by oxidative bleaching immediately after processing, the color can be easily removed by treating it with a solution containing a reducing agent.

However, even if the fabric is treated with a reducing agent for some time after being processed, the color will fade a little, but the color of the fabric will not be bleached and will remain as 7mm.

When we investigated a method to completely decolorize this stain, we found that the stain can be completely decolorized by immersing it in a solution containing 7.logen before treating it with a reducing agent, and then applying the reducing agent to it.

The halogen solution used at this time may be alcohols such as methanol, ethanol, isopropanol, polyhydric alcohols such as ethylene glycol or hexylene glycol, water-soluble organic solvents such as acetone, or a combination of these and water. It is obtained by dissolving bromine, iodine, chlorine, etc. in a mixture of

The halogen is preferably dissolved in the solvent in a range of 0.1% to 5%.

If it is less than 0.01%, the effect will be insufficient, and if it is more than 5%, there will be many disadvantages such as deterioration of the textile product and strong odor.

A surfactant or a polymer may be added to improve the stability of the halogen solution.

In order to increase the solubility of map ζ and no-rogen, a salt such as potassium no-rogenide may be added.

Although any reducing substance can be used as the reducing agent for treatment after immersion in the halogen solution, water-soluble substances are preferred for practical purposes.

Examples of these preferable reducing agents include the following.

Sulfites such as sodium sulfite, bisulfite salts such as sodium bisulfite, sodium hydroalphite, sodium formaldehyde sulfoxylate, sodium thiosulfate, ascorbic acid, etc. . However, it is not limited to these.

The reducing agent is preferably used in the form of a solution, and its concentration is not particularly limited, but from the viewpoint of workability, cost, and effectiveness, it is 0.2
It is preferable to use it in the range of ~20%.

Although the treatment temperature with the reducing agent solution is room temperature, it is sufficiently effective. The effect is accelerated by heating.

An example will be shown to specifically describe the method of the present invention. Example 1 Cotton knit g product actually used in a medical institution and contaminated with chlorhequine digluconate (obtained from Tokyo Baby Laundry) The fabric was bleached with a sodium hypochlorite solution to color the contaminated area, and the fabric was used as a test fabric.

An uncontaminated portion 5αX53 of the test cloth was cut out and used as a standard cloth.

A 5 tys x 5" stained and colored area was cut into untreated fabric.

The untreated cloth was immersed in ethanol containing 0.5% iodine for 10 minutes, then taken out and washed with water.

This was immersed for 30 minutes in a 5% aqueous solution of sodium hydrosulfide heated to 50C, then taken out, washed with water, and dried to obtain a treated cloth.

The Y values of the standard fabric, semi-fabric, untreated fabric, and treated fabric were measured using a colorimeter, and the results were as shown in Table 1.

As shown by the numbers in Table 1, the treated fabric was bleached to a whiteness that was no different from the standard fabric when viewed with the naked eye.

Example 2 The same untreated fabric as in Example 1 was treated with 70% iodine containing 0.5% iodine.
After soaking in 5% aqueous sodium formaldehyde sulfoxide/late solution for 10 min,
Soak at 0C for 30 minutes, wash and dry.

Table IVCY values are shown.

As in Example 1, the color was bleached to the same whiteness as the standard cloth when viewed with the naked eye.

Reference Example An untreated cloth similar to Example 1 was immersed in a 5% dithionite acetate solution without being treated with an iodine solution at 50C for 30 minutes, washed with water, and dried.

Table 1 shows the Y value.

When viewed with the naked eye, the treated fabric was bleached even before the treatment, but it was more colored than the standard fabric, and it was observed that some stains remained.

Table 1 Standard fabric Untreated fabric Treated fabric Example 1.83, 6 77.4 84.0 Example 2.
88.6 77.0 82.6 Reference example 88.6 77
．． 0 79.1 Using the Toyo Rikagaku Kogyo Integrating Sphere Colorimetry Color Difference AU-3C) I-2 model, fold a piece of cloth double-tailed and place it on the sample stand of the measurement hole of -cs o yyms and hold it down with the sample holder. I measured it with a reflective method and it was 7.

Claims (1)

[Claims] A method for decolorizing a textile product processed with chlorhexidine or its salt by immersing it in a solution containing iodine and then subjecting it to reduction treatment.