The boiling method is to heat and boil the amines, phenols or nitro compounds of aromatic hydrocarbons and sodium polysulfide in water or organic solvents to prepare black, blue and green sulfur dyes.
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Similar to direct dyes, salt can be used to promote dyeing. Cationic color fixing agent and metal salt color fixing agent to improve the fastness to travel.
Similar to vat dyes, dyes need to be restored to leuco with reducing agents before they can be dyed on fibers and oxidized on fibers. Just don’t use strong reducing agent sodium sulfide, but weak reducing agent sodium sulfide. However, the directness of the leuco body to the fiber after reduction is lower than that of the vat dye, and the tendency of the dye to accumulate is large.
When it reacts with acid, it can generate hydrogen sulfide gas, and when it reacts with aluminum acetate, it can produce black aluminum sulfide accumulation.
A higher temperature can be used to increase the diffusion rate of the dye and improve the degree of penetration.