REACTIVE BIFUNCTIONAL DYES

Allofix 'ME' Dyes

Allofix 'ME' Dyes or Mild Exhaust Dyes or Bifunctional Dyes

ALLIANCE ORGANICS LLP bifunctional Reactive dyes with improved business properties, high colour yield and applicable at lower dyeing temperatures like 60°C which naturally leads to energy conservation. The main characteristic of this new range is a dye molecule having a Sulphatoethyl Sulfone group linked to the chromophore through a monochloro triazine group as a bridge link. A typical Allofix ME colour has the structure

As can be seen from the structure the dyestuff has both MCT as well as VS molecules. What are the advantages?

Advantages due to to VS group

(i) The covalent bond between the Sulphatosthyl Sulfone and Cellulose I stable to acid hydrolysis. Consequently, dyed goods display good stability in storage in an industrial atmosphere.

(ii) The hydrolysed part of Allofix 'Me' Dyes colour is largely made up of Hydroxyl Ethyl Sulfone type which has virtually no affinity to cellulose. Hence there is little risk of staining on adjacent whites.

Advantages due to MCT group

(i) Increase in substantivity due to MCT leads to better exhaustion and fixation.

(ii) Using Triazine as the bridge link it is possible to select a wide range of chromophores having good fastness to light. Washing and other wet treatments."

Advantages due to the simultaneous presence of both VS and MCT groups

(i) Increased alkali stability which is of great advantage ink continuous dyeing or in cold pad-batch

(ii) Possession of two different types of Reactive groups differing in reactivity widens the range of optimum dyeing temperature and allows for improved reproducibility.

(iii) Since Allofix 'ME' Dyes are of mixed bifunctional reactive types they display a unique feature in that, the difference between degrees of exhaustion and fixation is much smaller than that of dyes having single reactive group.

Level Dyeing

This is governed by the rate and degree of exhaustion, migration property and fixation rate. Allofix 'ME' Dyes colours have moderate affinity and exhaustion coupled with high migration fixation. Hence level dyeing presents no special problem.

Exhaust Dyeing Curves

For the guidance of the practical Dyer, we have plotted the degree of exhaustion vis-à-vis time and dyeing temperature so that the Dyer can select suitable elements or combination shades. Exhaustion curves follow as an annexure to this bulletin.

Properties

Varying alkali content in the fixing bath.
Varying salt content in the bath
Varying liquor ratios in the application.
Varying dyeing temperature between 50 -70°C

Dyeing Process of 'ME' Dyes