Development Progress Of Reducing Dyes In China

It has been used for 104 years, and today it is an important cotton dyestuff category for reactive dyes, which are used in the manufacture of advanced products or functional products of cellulose fibers. Especially with the rapid development of the national economy, people's consumption needs are becoming more diversified, and the demand for functional, comfortable and fashionable clothing is getting higher and higher. It is estimated that by 2010, more than half of the world's textiles will reach the middle and high grade requirements, and vat dyes will not only have better performance than other cotton dyes, but also have unique color and functionality. Therefore, vat dyestuffs still have certain vitality despite complex manufacturing and serious pollution. Currently, the use of vat dyes for printing and dyeing in the United States and Europe and other countries is much more than that in Asian countries. It is understood that reductive dyes (referred to as vat dyes) have a long history, found in 1901, reduced blue RSN calculation.

Vat dyes have a series of notable characteristics compared with other dyes.

(1)

The color is mostly in the middle color.

The color of vat dyes has a complete series of characteristics ranging from yellow to black and from bright to general colors. The most important feature is that the intermediate color is the majority. These intermediate colors are basically single components and have good reproducibility, especially green, olive green, meat color, brown and grey series. For example, green reactive dyes are usually made of yellow and turquoise blue reactive dyes. In order to combine reactive dyes with different dyeing properties, the control of dyeing is very important. In addition, there are several single structural green varieties in vat dyes, which can not only meet different needs, but also have excellent dyeing reproducibility compared with reactive dyes.

2. It has excellent light fastness and various composite fastness based on light fastness.

At present, the various fastness to light fastness on cotton fabrics, such as perspiration fastness, sweaty sunlight, washing fastness, sweat and sunlight - rubbing fastness and so on, are getting higher and higher. Especially for light colors, vat dyes have special properties compared with other types of cotton dyes (Table 3), so they are very suitable for dyeing and printing of work clothes, summer clothes, sportswear, coats, curtains, furniture covers, etc.

Excellent chlorine resistance and moisture fastness.

Vat dyes have excellent chlorine fastness compared with reactive dyes (Table 4), both chlorine and 20ppm, and chlorine (500ppm) fastness. In addition, table 3 also shows that VAT has excellent washing fastness. Therefore, vat dyes are suitable for printing and dyeing fabrics such as hotels, hospitals, fabrics, bedding, outer covers, sheets, clothes, etc., especially for those products that require repeated washing treatment.

In addition, vat dyes are also suitable for dyeing and printing of textiles requiring the highest wet fastness, such as dyeing with reactive dyes and textile printing with vat dyes.

In addition, in the United States and Europe and other countries and regions, in order to reduce washing water, using strong detergents to add four acetyl ethylene diamine (TAED) into peroxide, a new type of detergent is produced, or a large quantity of detergents and washing in warm water are used in washing water.

It has excellent stability for finishing and finishing of printing and dyeing fabrics.

Vat dyes have little competition for general resin finishing. In recent years, functional dyes such as shape memory processing, shape stabilization, deodorization and antibacterial processing have been developed. Vat dyes have good stability, and vat dyes are more stable than those of reactive dyestuffs.

Suitable for

One bath coloring

One bath dyeing of polyester / cotton, brocade / cotton, vinylon / cotton blended fabric is more and more popular in the printing and dyeing industry. The vat dyes have the same coloring characteristics. They are suitable for one bath continuous dyeing, printing and dyeing with equal colors for these blended fabrics. These dyed fabrics can be used to make student clothes and various kinds of fabrics.

Moisture permeable coats and special textiles, especially military uniforms and combat clothing, such as camouflage clothes, have excellent special properties such as fastness and infrared resistance.

Good resistance to reduction.

This characteristic of vat dyes can be used to produce reactive dyes, dyestuffs and vat dyes, advanced dyeing of textiles, polyester / cotton knitted fabrics with no ground dyeing (liquid flow dyeing machine), polyester / cotton blended fabric pre dyeing (cheese dyeing) and polyester / cotton blended fabric with high degree of printing and dyeing (using URS method).

It can be dyed into a color with a natural tone and a very clear sense of color.

The fabric dyed with vat dyes can show natural plant hue and European style characteristics on the basis of coarse hue. For example, the dyed fabric of indigo dyed and vat dyes can be washed, washed, bleached and so on. It can make fabrics with extremely clear and natural plant hue.

In summary, vat dyes have a series of notable characteristics compared with other cotton dyes, especially in terms of fastness (Table 5). Therefore, vat dyes are still a valuable cotton dye.