The so-called special color refers to a dye that is unusually bright in color, can not be used in common dyes, and has a certain dyeing property. Such as: active turquoise, active brilliant blue.
The basic properties of active turquoise and reactive brilliant blue belong to the category of medium-temperature reactive dyes, but there is a strong "personality" in practical performance.
For example, active turquoise, because it is a copper phthalocyanine type vinyl sulfone dye, has a large molecular weight and is seriously lacking in linearity, so its diffusion ability is poor, its reaction ability is weak, difficulty in deepening, and poor fastness. Because of this, in the dyeing by the dip dyeing method, the soda ash which is weaker in alkali is used as the fixing agent, and it is necessary to absorb the color at a high temperature (80 ° C) and fix the color. If it absorbs color at medium temperature (60 ° C), fixes color, or absorbs at high temperature (80 ° C), and fixes at medium temperature (60 ° C), it must be made of tribasic phosphate or complex alkali (soda + caustic) As a fixing agent. Practice has proved that only in this way can the effective diffusion rate and fixation rate of the active turquoise be effectively improved, thereby obtaining a good leveling and transfection effect, a high fixing depth, and better color fastness.