Acid Dyestuff


acid dye chromatography is complete, bright color, light fastness and wet fastness dyes with different varieties quite different. And compared with direct dyes, acid dyes simple structure, the lack of a double bond and longer co-planar structure Noir same, so the lack of direct cellulose fibers, can not be used for dyeing cellulose fibers. Different types of acid dyes, due to the different molecular structures, so that they are different dyeing properties, staining methods used are also different.


acid dye according to their different chemical structure and into the strongly acidic dyeing condition, weakly acidic, acidic media, complex acid dyes.

Acid Dyestuff

strongly acidic dye

an acid dye first developed, dyed in strong acidity required dye bath, the molecular structure is simple, low molecular weight, a sulfonic acid group or carboxy, little affinity for wool, the wool can move evenly, uniformly dyed, it is also known as acid leveling dyes, but not deep shade, poor wash fastness, and there is damage to the wool during dyeing, after dyeing poor wool feel. The Acid Red G (i.e., C.I. Acid Red 1).

weak acid dyes

strongly acidic dye by increasing the molecular weight, introducing aryl sulfone group or the like introduced into the long carbon chain or the like which generates weakly acidic dye. Molecular structure is more complex, a larger affinity for wool, the wool can be dyed in acid medium, no damage of the wool, deep shade, fastness is improved, but dyeing unevenness. The weakly acidic Brilliant Blue RAW (i.e., C.I. Acid Blue 80).

acid mordant dyes

with certain metal salts (such as chromium salts, copper salts, etc.) as mordant treatment to form a metal complex acid dyes on the fabric. Mordant procedures more complicated, but it can give Light, washing, rubbing fastness of dyeings better performance, such as Mordant Black T (i.e., C.I. Mordant Black 11).

acid complex dyes

acid dye complex formed from certain chromium, cobalt and other metals. Soluble in water, lightfast dyeings which, excellent light fastness properties. It dye precursor and acid mordant dyes are similar, but in the preparation of the dye, azo dye molecules have been introduced into the metal atom, the metal atom ratio of dye molecules to 1: 1, it is also known 1: 1 metal complex dyes. Not need to use mordant dyeing process. The acid complex Yellow GR (i.e., C.I. Acid Yellow 99).

Another acid complex dye molecules do not contain a sulfonic acid group, a sulfonamido group and the like containing hydrophilic groups, metal atoms to dye molecules molecular ratio of 1: 2, it is also known a : 2 metal complex dyes. It is dyed in a neutral or weakly acidic medium, so called neutral dyes. The neutral gray 2BL (i.e., C.I. Acid Black 60).

Acid dyes are azo type, anthraquinone, triarylmethane type and the like, but most belong to the azo dye. The production of dyes and acid complex dyes generally similar, but the metal complex must be increased step process, such as neutral gray 2BL, first by 2-aminophenol-4-sulfonamide diazotization, and 1-acetyl-amino-7 - naphthol coupling and then with sodium salicylate chromium complex formed.

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