Acid dyes in dyeing

Acid dyes is water soluble dye with a structure of acidic groups, and can dyeing in acid medium. Most acid dyes containing sulfonic acid sodium salt, soluble in water, bright color with complete chromatography. It mainly used for wool, silk and nylon dyeing, also available in leather, paper, ink, and so on. But it can not dyeing to cellulose fibers.

The common problems of acid dyes in dyeing are color change, leveling is not enough and so on. In addition to the poor quality of dyes, improper operation or not well handled details are causes to the problems. The characteristics of acid dyes of polyamide: quick dyeing, poor evenly stained, so it requires using suitable levelling agent; poor dyeing fastness, it requires solid-color processing, especially darker varieties; dyeing processes: 50-600C started dyeing and - 1000C ensure--water has solid-color process.

According to its chemical structure and dyeing conditions, acid dyes are divided into strong acid, weak acid, acid media, acid complex dyes and so on. First development acid dye requires dyeing in strong of acid dye bath. The molecular structure is simple, molecular volume is low. It contains sulfonic acid base or carboxyl, it can dyeing well on wool, so it also called acid uniform dye dye. But its resistance wash fastness is poor, the hand feel of wool is poor after dyeing because of the dyeing on wool has damaged. Acid dyes have azo, Anthraquinone, Miyoshi methane and so on, but most of them belong to the azo dye.

Of the developed acid environmental dyes, red acid dyes are as follows: C.I. acid red 37, C.I. acid red 89 (weak acid red 3B, 2BS), C.I. acid red 145 (weak acid brilliant scarlet GL), etc. C.I. acid red 336 and C.I. acid red 361 are important species of red spectrum. Orange acid dyes are C.I. acid orange 67 (weak acid yellow RXL), C.I. acid orange 116 (acid Orange AGT), C.I. acid orange 156 (weak acid orange 3G). Yellow acid dyes are C.I. acid yellow 42 (weak acid yellow Rs, acid yellow r) and the C.I. acid yellow 49 (acid yellow GR200).