The Dye Industry Separation Technology
The Dye Industry Separation Technology
The role of high-purity synthetic dye industry is much more important in new emering industry and rearch field. Such as ink-jet printing dye requirs no or less of inorganic salts and other organic impurities, to ensure the storage stability, color vividness and fast print quality inducators of the ink-jet ink. It need high purity dye to receive convincing reliability data in dye performance base reaearch. Our production of commercial dyes is the major supplier of textile, priniting, paper making and other industries, which has less demanding of the dye purity. The crude dye contains lots dye intermediates, acid-base neutralization inorganic salts in synthetic dyes process, and mass inorganic salt in dry salting. Besides, To ensure dye be the commerical requirments, still need to add mass filler, for water-soluble dye, the filler is mainly water-soluble inorganic salts, like NaCl, to make some commerical dyes salt conteng to be about 40%. In the past, to separate and purity water-soluble dye containing SO3Na, the common way is to dissolve dye in DMF, remove inorganic salt, add acetone and chloroform to make it solid and separate. This way is better one to remove inorganic salt. But with dye homologue, especially after a short coupling reaction was difficult to separate the pure anionic dyes. Gel chromatography, thin layer chromatography, high performance liquid chromatography is an effective method of separation and purification of dye, Unfortunately, these methods can only get a small amount of pure dye in the laboratory.
Membrane separation is the high efficiency technology quicly development in this years, it has been used for a variety of polymer film or organic dye desalination. Such as, reverse osmosis membrane, nanofiltration, ultrafiltration. And due to the aperture size of nanofiltration is just suitable to dye molecules entrapped dye industry got the most attention.China is the big country of dye production, but the purification of dye far behind the advanced countries, and the require quantity is growing quickly of purity dye, ink-jet ink, digital dye printing paste, high fixation rate and high brightness are required reactive dyes purification, therefore, the research and development of industrial technology is imperative dye separation and purification. Toper adopt nanofiltration technology industrl test units to water-soluble dye desalination dedoped, acid yellow, azo dyes nanofiltration separation and purification process conductivity and absorbance method Dye desalting and to miscellaneous effects.
