Interviewed by IS Co., Ltd. /Senshoku Keizai Shimbun

Kotani Chemical Industry Co., Ltd. has developed and put onto the market Neoleve NYC-D and Neoleve NYC-R, staining inhibitors for nylon/cotton or rayon blends. The two products have been developed for potent prevention of nylon staining, each for use with different dyestuffs and dyeing method for medium to pale shades in cotton.

Reasons for the development

Mr. Kotani, president, explains in the following the purpose of developing two types of nylon staining inhibitors (Neoleve NYC-D and Neoleve NYC-R).

Since there is diversity in the consumer's preference for color quality, dyeing fastness in nylon/cotton or rayon blends varies accordingly.

It is necessary, therefore, to manage various dyeing techniques in accordance with the price of clothing of the consumer's preference, as well as the use of dyestuffs of various grades, from high, mid to low, depending on the desired quality and prices.

It is often believed that the use of high grade dyestuff causes less trouble and is safe, and no question is raised for the selection of anti-nylon-staining agent as long as it is compatible with these particular kinds of dye.

However, because of the circumstances mentioned earlier, certain devices are called for in the making of anti-staining agents for nylon. In dyeing nylon/cellulose blends, direct or reactive dyestuff, used on the cellulose side, causes considerable staining on nylon.

The more staining produced, the poorer colorfastness to washing/light and fixation to cellulose will result. Problems such as poor reproducibility will easily occur with color tones of direct/reactive dyes that have caused staining to nylon often differing from the original tones fixed to the cellulose.

As there is more variation in the consumer's preference (quality and price), dyeing problems such as the above occur more frequently.

For solution, two types of Neoleve have been developed.

Kotani has released the following details:

Neoleve (anti-staining agent) series according to 3 different dyeing methods

Neoleve NYC-D has been developed for the prevention of nylon staining in neutral to acid dyeing of nylon/cellulose materials.

Equally, as shown in Table 1 (3), Neoleve NYC-R is suitable for alkaline deep-dyeing, in which improved prevention of staining on the nylon side can be expected.

Table 1 Nylon/cellulose blended dyeing can be divided into (1), (2) and (3).

	Dyes on the nylon side	Dyes on the cellulose side	Dyeing conditions	Anti-staining agents
				NYC-D	NYC-R
Dyeing procedure (1)	Acid, Metal acid	Direct	pH=5-6 One bath dyeing	○	-	See Figure A
Dyeing procedure (2)	Acid, Metal acid	Reactive (neutral fixing)	pH=7 One bath dyeing	○	-	See Figure A
Dyeing procedure (3)	Acid, Metal acid	Reactive	Nylon side: acid dyeing Cellulose side: alkali dyeing Two bath dyeing	-	○	See Figure A