The Preparation For Liquid Basic Dyes And Application Of Nonionic Surfactants In Solubilization

Dyestuff industry has made great achievement since 20th century. With the advancement of science technology, people bring forward higher requests on dyestuff industry, one of which is that commercial technology of dyes has been applied in dyes synthesis increasingly. Today liquid dyes develop quickly owing to the progress of commercial technology and appearance of various surfactants, especially predominant applied performance of themselves. A great many of foreign dyestuff companies are dedicated to liquid dyes' development and have acquired remarkable production.This paper mainly works on the preparation of concentrated stable liquid basic dyes including C.I. Basic Yellow 2 C.I. Basic Orange 2 C.I. Basic Brown 1 C.I. Basic Blue 26 C.I. Basic Blue 11 C.I. Basic Blue 7 C.I. Basic Violet 3 C.I. Basic Green 4 and C.I. Basic Yellow 13. Because there must be a salt-out process in synthesizing dyes which causes high content of salt in solid dyes, 10~20%NaOH is used to wash and purify solid dyes, then dyes base is extracted by benzene or toluene. Dry dyes base is dissolved in the mixture of glacial acetic acid( or formic acid) methanol and distilled water to abtain concentrated stable liquid basic dyes. In addition, in order to improve solubility and stability of liquid dyes, some nonionic surfactants(NP-15, NP-21, NP-30, OS-15, EL-5, EL-15, EL-40, A-10, A-20, T-80) are added in the process of preparation, and their interactions with liquid dyes have also been researched.The results show that glacial acetic acid is superior to formaic acid in stability. Liquid basic dyes made in this paper are able to achieve the content of 40%, furthermore, that using a little amount of additive nonionic surfactants(NP-15, NP-21, NP-30, OS-15, T-80, EL-40) would improve solubility in water and stability of liquid dyes remarkably which no deposition separates out for 2 month in low temperature(-18 ℃).