Definition | Characteristics of Sulpher Dye

Sulpher dyes are complex heterocyclic molecules or mixtures formed by melting or boiling organic compounds containing amino and nitro group with Na polysulphide. Sulpher dyes are so called as they all contain sulpher linkages within their molecules.

Dye - S - S – Dye + 2[H] = Dye – SH + SH – Dye

     [Water insoluble]                 [Water soluble]

Dye – SH + SH – Dye + 2[o]  =  Dye - S - S – Dye + H₂O

    [Water soluble]                            [Water insoluble]

Characteristics of sulpher dye-

1.       Sulpher dyes have sulpher linkages within their molecules.

2.       Sulpher dyes are highly colored water insoluble dyes.

3.       They have no direct affinity towards cellulosic fiber.

4.       Sulpher dyes have good light fastness with rating about 4.

5.       These dyes have excellent wash fastness with rating about 3-4.

6.       They are exclusively amorphous.

7.       Sulpher dyes are suitable for heavy and durable shades.

8.       Sulpher dyes are cheap and easy to manufacture.