Cationic dyes in China.

Cationic dyestuffs are produced with the development of petrochemical industry. With the emergence of acrylonitrile fibre in 1950s, Geigy Company of Switzerland and Bayer Company of Germany developed cationic dyestuffs for acrylonitrile fibre one after another. In the early 1960s, China also developed the first generation of cationic dyestuffs, and in the 1970s, the second generation of X-type cationic dyestuffs was developed, which enlarged the range of chromatography, improved the dyeing performance, and took into consideration of the compatibility between the ternary colours, and in the 1970s, the third generation of M-type cationic dyestuffs was produced in the trial, which is called migratory cationic dyestuffs, and it can be applied to dyeing all kinds of acrylonitrile fibres.

In the developed countries of the world that produce dyestuffs, the sum of the production of cationic dyestuffs and basic dyestuffs only accounts for less than 10% of the total production of dyestuffs. In the 1990s, the output of cationic dyestuffs in China was more than 2,000 tonnes/year, accounting for only 1% of the total output of dyestuffs, and some of them were exported. Among the cationic dyestuffs, X-type three primary colours and cationic peach red FG and brilliant red 5GN are the varieties with larger output.

In recent years, domestic and foreign countries have devoted themselves to the research and development of varieties with excellent dyeing performance, speciality and new structure, as well as the improvement of old products' process, energy saving and three-waste treatment.