Synthesis And Application Of The Thiazole Heterocyclic Disperse Dyes

Azo disperse dyes occupies more than half. Compared with other structures, the raw materials of azo-based disperse dyes are easy to obtain. The synthetic process of them is simple and the color shade is bright and strong. So they are paid more and more attention and their production continues to increase. In azo disperse dyes, there are some dyes containing heterocyclic compounds as the diazo component or coupling component. Because of the existence of heterocyclic compound, these dyes generally have brighter color and luster, higher strength of color, and the fastness is good. They also can be appled to a wide pH range (4-12). In recent years, more attention has been paid on the development of heterocyclic-aromatic amine disperse dyes, in which heterocyclic compounds being diazo group.To meet the needs of market and production of enterprises, this paper is to develop heterocyclic disperse dyes suitable for wide pH range dyeing. A new intermediate,3-(N-benzyl)-amino acetanilide, was synthesized, and synthesis process was investigated. The influence of temperature, ratio of materials, and composition of solvent has been studied. With the method of dissolving in acid solution and precipitation by alkli, the product was purified. The synthesized intermediate was characterized by1H-NMR and infrared spectrum.The diazotized3-amino-5-nitro-2,1-benzisothiazole coupled with N-ethyl-N-acetoxyethyl aniline and3-(N-benzyl)-amino acetanilide, respectively and Dye1and dye2were obtained. The diazotized2-amino-5,6-dichlorobenzothiazol coupled with N-ethyl-N-acetoxyethyl aniline, 3-(N-benzyl)-amino acetanilide, N-ethyl-N-phenylbenzamide3-methal-aniline, and N-ethyl-N-phenylbenzamide-aniline, respectively. Dye3, Dye4, Dye5, and Dye6were obtained. After further purifiecd, six disperse dyes were characterized by ultraviolet-visible spectra, infrared spectra,1HNMR spectra and elemental analysis.Polyester fabrics were dyed by the synthesized six dyes, using high temperature high pressure dyeing method. The performance of the six dyes was evaluated, including ordinary dyeing and dyeing in different pH solutions. The buildings up properties of them were also investigated. With the pH increasing, the K/S value of six dyes reduced in different degree. Dye1,4,6had an relatively obvious change. Dye2,3,5were steady when pH was4.5-8.5, the color staying same, which illustrated the three dyes were suitable to dye in a wide pH range. Color fastnesses of the dyed polyester fabrics were measured, such as washing fastness, wet and dry rubbing fastness, light fastness and fastness to sublimation. The results show that the dyed fabrics with six synthesized dyes all have good rubbing fastness. Dye2and4have good washing and sublimation fastness.