Preparation Of Liquid Disperse Dyes With High Solid Content

Instead of the traditional dispersants, such as, sodium ligninsulfonate and Dispersant MF, we used the polymeric dispersants to grind the crudes of C.I. Disperse Yellow211, C.I. Disperse Red343, C.I. Disperse Blue79and C.I. Disperse Yellow54, respectively. Under such grinding conditions as the dosage of dispersant was30%based on dried disperse dyes, the grinding medium were zirconium beads (diameter of0.6-0.8mm), we could get liquid disperse dyes with high solid content and average particle size of less than1μm. Such liquid disperse dyes possessed good performances, for examples, high storage stability, low-temperature and high-temperature dispersion stability. The particle size of the dispersion changed so little that it would not form two layers, when it was storied at natural environment for several months. The dyeing results show that such liquid disperse dyes exhibit the same dyeing behavious as their powder standard, i.e.. the shade and strength no difference between these two kinds of dyes.We used some of thickeners as protective colloidal agent, which were added into the liquid disperse dyes. The dosage of powder sodium polyacrylate (PAAS) was2.0%based on liquid disperse dyes. The dosage of liquid ethyl acrylate/methacrylic acid copolymer (FATE) was0.5%based on liquid disperse dyes. These thickeners could increase the storage stability of the liquid disperse dyes, while not affecting the dyeing properties of the latter.The results of the present study show that such liquid disperse dyes can overcome the shortcomings of traditional liquid dyes. In the other hand, the dosage of the dispersants used was only1/6of Dispersant MF, which means the content of the dispersant in dyeing waste could be reduced to1/6, so it could reduce pollution to water envionment. Because such liquid disperse dyes exhibited the same dyeing properties as their powder standard, it needed no spray-dry process, which is equal to save water and energy. Therefore, if the liquid disperse dyes turn into production, it would be good for the sustainable development of the dye industry in China.