The Synthesis And Performance Of Heterocyclic Azo Disperse Dyes

Disperse dyes is a kind of small molecule, nonionic and hydrophobic dyes without sulfonic acid group, carboxyl, etc. Which was mainly used for dyeing polyester(PET). Disperse dyes entered into the fabric in a highly dispersed state rely dispersant during the dyeing process. Among the disperse dyes, azo disperse dyes has the largest propotion, and heterocyclic azo disperse dyes with features of high molar extinction coefficient, brilliant color fastness and chroma is an important category of azo disperse dyes, which has attracted a growing emphasis of dyes researchers in recent years.Because of the existence of hetero atom contained lone pair electrons in heterocyclic, the diazo component of heterocyclic azo disperse dyes is usually has a weakly alkaline. The diazo component need concentrated acid as a solvent to complete diazotization reaction so that a large quantity of waste acid residue which was difficult to treat will be produced, meanwhile diazonium salt obtained in concentrated acid system is hard to react with coupling component under an alkaline condition. Heterocyclic azo dyes especially both diazo component and coupling component contained hetero atom is still rarely reported in the reference.Aimed to the problems, this paper designed a diazotization method of heterocyclic diazo component, use organic solvent substitute for concentrated sulfuric acid to dissolute heterocyclic aromatic amines, join stabilizer fluoroborate to form a stable diazo complex salt. The salt can be separated from organic solvent system because of its low solubility. The method can not only reduce producing waste acid residue but also finish the reaction in both acid and alkaline environment. Diazotization yield was up to 99%, the organic solvent can be recycled for 5 times. With the new method, we use 2-Amino-6-methoxy benzothiazole as diazo component, use 11 kinds of compounds such as 2-naphthol, pyrazolone, N,N-diethylaniline, etc. as coupling component, synthesis eleven novel heterocyclic azo dyes from dyel-dyell. Dyes yield was respectively 66%-95% in alkaline system and 95%-99% in acid system. Molecular structures were characterized with HNMR, HRMS, FTIR and UV-visible spectra. The dyes used for dyeing fiber by means of high temperature-ultrahigh pressure method. Dye uptake is up to 99%,chroma C* is up to 69.44, molar extinction coefficient is up to 82508 (L.mol-1.cm-1), average washing fastness is 4-5, average rubbing fastness is 4-5, average washing fastness is 4-5, average sublimation fastness is 2-3. Among them, the highest dye chroma and molar extinction coefficient are higher than the traditional disperse dye reported in the reference.