Acid dyes is a kind of water-soluble dyes with acid groups in structure. It is dyed in acid medium. Most of the acid dyes contain sodium sulfonate, soluble in water, bright color and complete chromatography. The chromatogram of acid dyes is complete and the color is bright. The fastness to sunlight and wet treatment varies greatly with the variety of dyes. Compared with cellulose, it is short of direct structure, so it can't be used in direct dyeing. Different types of acid dyes have different dyeing properties and different dyeing methods because of their different molecular structures.
According to their chemical structure and dyeing conditions, acid dyes can be divided into strong acid, weak acid, acid media, acid complex dyes and so on.
It is mainly used for dyeing wool, silk, nylon, leather, paper and ink. Generally, it has no coloring power to cellulose fiber.
Basic dye (s), also known as basic dye. The dyes can be dissociated into cationic dyes in aqueous solution, so they are classified as cationic dyes. It is characterized by bright color, magnificent fluorescence (mainly rose red, yellow, orange and other colors), and strong coloring power, with a small amount of dyes can be obtained deep and rich color. The color fastness and light fastness are poor, but it has good fastness to acrylic fiber (polyacrylonitrile fiber). Basic dyes do not color cellulose fibers.
Usage: due to the poor light fastness and washing fastness after dyeing with basic dyes, it is now much less than that of fabrics. It is mainly used for coloring stationery, paper and lake making.