The Synthesis Of Black Reactive Dyes And Their Application

Cellulose fabrics have got people’s favor because of its good comfort ability. Reactive dyes are used for dyeing cellulose fiber, which have a large amount of dosage. Black color is one of the most important color spectrum. But so far, there is a lack of black reactive dye, which can evenly and fully absorb the whole visible light spectrum. At present, C.I. Reactive Black5is still with largest consumption and highest output value. However, C.I. Reactive Black5with low lifting property is navy blue. Deep black color can not be achieved with it.In this paper, synthesis process of C.I. Reactive Black5was optimized. Four new black reactive dyes containing multi-azo groups were synthesized. The chemical structures of the dyes were determined by FT-IR. Their vis spectra were detected. The synthesis processes of four new black reactive dyes were discussed.The result showed that the maximum absorption wavelength of dye2, dye3and dye4was within the range of590-635nm which is appropriate for being navy blue component in the use of getting black. The maximum absorption wavelength of dye5was660nm which is lean to green and not suitable for being navy blue component in the use of getting black. The synthesized dyes were used to dye cotton fabric to analysis their application property. The results demonstrated that dyeing rate and fixing rate of dye2and dye3was significantly higher than the C.I. Reactive Black5, and there was no big difference between fixing rate of dye4and of dye5. Four synthesized dyes were mixed with C.I. Reactive Black5in different proportions and the properties of the composition were investigated. The results indicated that the blending could improve lifting force of C.I. Reactive Black5effectively. The mixture with C.I. Reactive Black5had well color deepening properties for the cotton. The rubbing fastness, washing fastness and light fastness of the fabric dyed respectively with C.I. Reactive Black5and its mixed dyes were tested according to and corresponding standards and the result was good. Compared with C.I. Reactive Black5, the blackness of the mixing dyes were greatly improved.