The original dye by the purification, drying, crushing, post-processing, packaging and other processes made of dyestuffs.
The intermediates were synthesized by alkylation, diazotization, closed loop, coupling, condensation and other unit reactions. The above two steps, the process and process between the commonly used in the neutralization, filtration, cooling (ice), salting out, bubbling and other methods to separate the intermediate product or improve the quality and purity.
The basic raw materials (benzene, naphthalene, anthracene, etc.) through the nitrification, sulfonation, halogenation, reduction, alkali, ammoniation, hydrolysis, acylation and other chemical reactions, made of dye intermediates.
Coal chemical and petrochemical products are the main source of raw materials for the dye industry
