Mordant Dyes
Mordant Dyes

Mordant Dyes

These dyes have no substantivity towards textile material. Chemical binding agents are called mordants to help them to get attached to the fiber. They are also called chrome dyes, as they are mainly inorganic chromium.

 

Properties: 

  1. They do not have an affinity for textile material.
  2. They can produce dark shades.
  3. They exhibit good fastness properties and leveling properties.
  4. Dye fiber bond is strong ionic bonds.
  5. They have a metal ion present in their structure.
  6. They are soluble in cold water.

Mechanism:

A complex is formed with the dyes by the chromium ion when potassium dichromate is added to the solution of acid-mordant dyes in the presence of H2SO4. The complex is water-insoluble and gets precipitated in the fiber.

Three processes can be followed.

  1. Pre-mordanting also known as Chrome
  2. Meta mordanting also known as Metachrome
  3. Post mordanting also known as Afterchrome

Application: Natural protein fibers, nylon, and modacrylic fibers.