Basic Dye in Textile Processing

Study Notes

Basic dyes are also known as cationic dyes, which act as a base when made soluble in water, forming a colored cationic salt that reacts with anionic sites on the surface of a substrate.
They have less hydrophilic groups, making them insoluble in water, and require alcohol or acetic acid to dissolve, followed by dilution with water.
Basic dyes are sensitive to temperature, so both the dissolution-dilution and dye-bath temperatures should not be too high.

The chemical structure of basic dyes includes aromatic methane, triarylmethane, azo type, and nitrogen-containing heterocyclic compounds (such as xanthene, oxazine, and thiazine).

Chromophore: the part of the molecule responsible for absorbing visible light and giving the dye its color, including azo groups, conjugated imine groups, and heterocyclic rings.
Auxochrome: functional groups that influence properties like solubility, ionization, and color intensity or shade, including amino groups, alkylamino groups, and dialkylamino groups.

Extensively used for dyeing jute, silk, wool, coir, acrylic fibers, leathers, paper, and dried flowers

Have longer molecular structures than conventional basic dyes
Still cationic in nature, but exhibit improved fiber coverage and substantivity
Advantages over conventional basic dyes include better lightfastness, clear backwaters, and excellent substantivity.