Ice dye (chromogenic dye)

An ice dye, also known as a Nafto dye, is an insoluble azo dye that produces an insoluble couple by reacting a diazonium salt of a diazo component (chromophore) and a coupling component (chromophenol) on the fiber. A nitrogen dye that colors the fibers. When dyeing with an ice dye, the phenolic phenol is firstly combined with the phenol, and then the diazonium salt is reacted with the phenol which has been bound to the fiber to carry out coupling to form an insoluble azo dye. Since it needs to be cooled to below 10 ° C with ice during coupling, it is called an ice dye. As early as 1880, the British R.Hollidav soaked (ie, after the base) cotton fiber in the β-naphthol dye alkaline solution, and placed it in diazotized p-nitroaniline solution to develop color (bright red) ). Since then, this staining method has rapidly spread. In order to obtain better fastness, after 1912, the base primer 2-hydroxy-3-formanilide (chromophenol AS) was developed to improve the light fastness and fastness. The status of azo dyes. In 1923, acetoacetanilide was developed to make up for the lack of yellow dye. Since then, ruthenium, osmium, carbazole hydroxyamide and phthalocyanine sulfonylaminopyrazolone have been successively released, so that it can be dyed in full hue. There are 30 kinds of primers, such as phenolic AS-D, AS-E, AS-G, AS-GR, AS-LB, AS-OL, A S-PH, etc., most of which have 2-hydroxy-3-methyl The basic structure of anilide (chromophenol AS). For the printing and dyeing industry to be easy to use, the color base is made into a stable diazonium salt, called a color salt, which can be used for color development after being dissolved in water. According to the coupling speed, fastness and color, there are about 60 kinds of chromophores (including chromophores and color salts), most of which are anilines, such as yellow-based GC, orange-based GC, red-based B, large red G, blue. The color base RR or the like, but used as a black, mainly composed of aminodiphenylamines, diaminodiphenyls and aminoazobenzenes. Recently developed p-aminobenzoyl anilines are useful as excellent light blue. There are also many kinds of coupling components as bases, which are roughly classified into two types, β-naphthol and acetoacetanilide. It is also recommended to use phenylmethylpyrazolone and 4-benzoyl-1-naphthol. In addition, a mixed preparation of a mixture of a stable diazonium compound of various color groups and chromophenol is further provided, which further simplifies the printing and dyeing procedure. The products of ice dyes are not finished dyes, but two components of phenol and chromophore. However, for the printing and dyeing industry, it is easy to use, and the color base is often made into a stable form of chromogenic diazonium salt, which is called color salt and soluble. After water, it can be used for color development, which can save the printing and dyeing plant for diazotization. The ice dye has bright color, good fastness, complete chromatogram (but lack of bright green), high sun and soaping fastness, simple synthesis method and low price. It is widely used for printing and dyeing cotton fabrics. The emergence of reactive dyes in the 1950s reduced the use of ice dyes on cotton fibers.