The vat dyes are found amongst oldest natural coloring matters used for textiles. The name ‘Vat dyes’ derived from the large wooden vessel from which vat dyes were first applied.
Vat dyes provide textile materials with the best color fastness of all the dyes in common use. The fiber most rapidly colored with vat dyes are the natural and man-made fiber.
Properties of Vat Dye
- The fibers most readily colored with vat dyes are natural or man-made cellulosic fibers.
- Wash fastness is 4-5
- Light fastness is 7
- Production cost is higher than other dyes.
- Vat dyes provided textile material with the best color fastness of all the dyes in common use.
- Very expensive than other dyes.
Chemical structures of Vat dye :
Vat dyes are based on indigoids and anthraquinone. In general, vat dyes based on anthraquinone have better fastness properties than vat dyes derived from indigoids.
On the basis of chemical structure mainly two types of vat dyes: