Study On Preparation Of Liouid Reactive Dyes And Its Properite

Reactive dyes are characterized by full spectrum of color and bright color, which is one of the most important dye species. Currently, reactive dyes were mainly used for cellulose fiber, protein fiber and other fibers. Liquid reactive dyes have been more widely used as the automation of dyeing process and computer color matching developed. But the biggest problem of liquid reactive dyes is they can be easily hydrolyzed in aqueous medium, so the critical step for the preparation of liquid reactive dyes is to improve their storage stability by minimize hydrolysis of the dyes. On the one hand, K-type liquid reactive dyes and bi-functional reactive dyes were chosen to be the object of the research, the content of inorganic salts for commodity dyes was reduced through the purification, the stable pH range of liquid dyes were measured, an appropriate buffer solution was used to enhance the stability of the liquid reactive dyes, also a suitable organic solvent was selected to raise the concentration of the liquid reactive dyes. On the other hand, three kinds of K-type reactive dyes were synthesised by dye intermediate. To get a stabilized and concentrated liquid reactive dye by using the dye with high purity which were removed unreacted intermediates and small molecules of the dye solutions after synthesis by nanofiltration instead of salting-out and other processing of commercialization, also adding a suitable buffer to enhance the stability of the liquid reactive dye. The main results are follows.(1) K-type reactive dyes. The inorganic salts content of commodity reactive yellow K-6G was reduced through the optimal purification process, so that the concentration and the stability of the liquid dyes were increased. That the stable pH range of liquid reactive yellow K-6G is6-7.5, Tris+EDTA-2Na was selected for buffer solution and the consumption is around5%, those were chosen for organic solvent like n-butyl alcohol, dimethylcarbinol, N,N-dimethyl formamide, also the dosage in10%has good effect.(2) Bi-functional reactive dyes. Selecting the method of nanofiltration to purify bi-functional reactive dyes such as reactive golden yellow R-4RFN, reactive red R-2BF and reactive blue3GF by the comparison of different purification methods to get the dye with the high purity. The results shown that the stability of bi-functional liquid reactive dyes was better when pH is about7, the inorganic salts content of liquid dyes is lower the stability of the dyes is better. Liquid reactive dyes possess high concentration and good stability when Na2HPO4+KH2PO4was selected for buffer solution and the dosage in4%as well as n-butyl alcohol for organic solvents and the dosage in3%, also their exhaustion and fixation rates are higher than powder reactive dyes.(3) Synthesising three K-type reactive dyes which contain an active orange and two kinds of active red by using o-aminobenzene sulfonic acid as diazo component, respectively, J acid, H acid, r acid as coupling component. To get the optimal process route and conditions through multiple sets of comparative experiments of different synthesis processes. The effect of different coupling components on the shade and solubility of the dye were compared through their maximum absorption wavelength and solubility. The unreacted intermediates and small molecules of the dye solutions after synthesis were removed directly by nanofiltration, also Tris+EDTA-2Na was selected for buffer solution and the consumption is around5%.