Reactive dye

In a reactive dye, a chromophore (an atom or group whose presence is responsible for the colour of a compound) contains a substituent that reacts with the substrate.

Reactive dyes have a low utilization degree compared to other types of dyestuff, since the functional group[which?]

Rattee and Stephens at Imperial Chemical Industries (ICI) popularized the chlorotriazines as linkers between the substrate and the chromophore.

The chromophore, with an amine functional group, is attached to the triazine, displacing one chloride:[citation needed] The resulting dichlorotriazine can then be affixed to the cellulose fibre by displacement of one of the two chloride groups:[citation needed] The fixation process is conducted in a buffered alkaline dye bath.

Other bifunctionals have been created, some with fastness (better quality) or only fixation degree (better environment or economy) in mind.