METHOD OF PREPARING AQUEOUS DISPERSION OF OXIDIZED SULFUROUS DYE Russian patent published in 1995 - IPC

FIELD: chemical technology. SUBSTANCE: aqueous dispersion of oxidized sulfurous dye is prepared by method of diaphragm separation of dye prepared as suspension after sulfuring product oxidation from inorganic impurities at the constant water addition up to the parental suspension volume and, preferably, in the presence of surface-active substance. For separation diaphragm is used at pore size 0.01-0.2 mcm. After diaphragm separation dye suspension is desirable to concentrate by anhydrous diaphragm separation. Prepared dye does not contain inorganic salts at particle size not exceeding 16 mcm. EFFECT: improved method of oxidized dye preparing. 4 cl