What is the solubility of reactive dyes?

Date:Mar 29, 2021

It can be roughly divided into four categories:

Class A, dyes containing diethylsulfone sulfate (ie vinyl sulfone) and three reactive groups (monochloros-triazine + divinyl sulfone) have the highest solubility, such as Yuan Qing B, Navy GG, Navy RGB, Golden: RNL And all reactive blacks made by mixing Yuanqing B, three-reactive group dyes such as ED type, Ciba s type, etc. The solubility of these dyes is mostly around 400 g/L.

Class B, dyes containing heterobireactive groups (monochloros-triazine+vinylsulfone), such as yellow 3RS, red 3BS, red 6B, red GWF, RR three primary colors, RGB three primary colors, etc. Their solubility is based on 200~300 grams The solubility of meta-ester is higher than that of para-ester.

Type C: Navy blue that is also a heterobireactive group: BF, Navy blue 3GF, dark blue 2GFN, red RBN, red F2B, etc., due to fewer sulfonic acid groups or larger molecular weight, its solubility is also low, only 100-200 g/ Rise. Class D: Dyes with monovinylsulfone group and heterocyclic structure, with the lowest solubility, such as Brilliant Blue KN-R, Turquoise Blue G, Bright Yellow 4GL, Violet 5R, Blue BRF, Brilliant Orange F2R, Brilliant Red F2G, etc. The solubility of this type of dye is only about 100 g/L. This type of dye is particularly sensitive to electrolytes. Once this type of dye has agglomerated, it does not even need to go through the floc process, and it will directly salt out.

In the normal dyeing process, the maximum amount of dye accelerator is 80 g/L. Only dark colors require such a high concentration of dye accelerator. When the dye concentration in the dyeing bath is less than 10 g/L, most reactive dyes still have good solubility at this concentration and will not aggregate. But the problem lies in the vat. According to the normal dyeing process, the dye is added first, and after the dye is fully diluted in the dye bath to uniformity, the dye accelerant is added. The dye accelerant basically completes the dissolution process in the vat.