The vat dye molecules do not have water-soluble groups, so they are insoluble in water; The dye has a large molecular structure, good coplanarity of aromatic rings and high affinity for cellulose fibers, so it has high initial dyeing rate, poor dye migration and is prone to uneven dyeing; It is mainly used for dyeing cotton, viscose and other fibers. The main dyeing methods are cryptochrome dyeing (immersion dyeing) and suspension dyeing (pad dyeing); The wet treatment fastness of dyed fabrics i

Vat dyes can be divided into two categories: indigo dyes and anthraquinone dyes. Indigo in the indigo group dyes is a kind of dye with the longest history of application. There are also halogen derivatives and isomers of indigo and thioindigo derivatives of indene framework belonging to the indigo group dyes; The Chromogenic System of indigo dyes is composed of a pair of electron donors and electron acceptors connected by the same vinyl group. This cross conjugated chromogenic system is called H

The supply of disperse dye intermediates remains tight, and the industry expects that a new round of replenishment will be launched next month. On April 20, Dazhi asdak news agency reported that Dazhi News Agency (wechat dzh_news) learned from the Shanghai dye exhibition held a few days ago that affected by the tight supply of upstream intermediate reductants, blue and black series, which account for a large proportion of disperse dyes, are gradually raising their prices by product, of which the