Azoic dyes are azo dyes formed on fibers by diazonium salts of diazo components and coupling components. In the application process of azoic dyes, the fiber generally first absorbs the coupling component (called naphthol in azoic dyes, commonly known as primer), and then uses the diazo component (called color base in azoic dyes, commonly known as color development Agent) diazonium salt treatment, thereby forming dyes on the fibers to achieve the purpose of dyeing. Since ice cooling is required during the diazotization process of the color base and the coupling color development process, Azoic dyes is referred to as Ice dyes.

Since azoic dyes have significantly better washing fastness than direct dyes and their more intense coloration, they have gradually developed into an important class of organic dyes. So far, there are more than 50 commercial varieties of naphthol and color base with different structures.

Azoic dyes are mainly used for dyeing and printing cotton fabrics. They can produce rich colors such as yellow, orange, red, blue, purple, red, brown, and black, especially the rich colors of orange, red, blue, red, and brown. The light fastness of these colors can reach level 6 or above. The washing fastness of azoic dyes is very high, and the chlorine resistance can reach level 4 or above. Some are also resistant to alkali boiling but generally not resistant to oxygen bleaching. Because of its low cost and unique rich color, it is widely used in the printing and dyeing of cotton fabrics.

In addition to being used for dyeing and printing cotton, azoic dyes can also be used for viscose, vinylon (polyvinyl alcohol fiber), nylon, silk, acetate fiber, etc. Naphthol and color base can be regarded as intermediates and are widely used in the synthesis of dyes and organic pigments. In particular, some naphthol and color base varieties are indispensable intermediates for the synthesis of organic pigments.