Chlorotriazinyl dyestuffs

For a new substance that is to be initially supplied at the base-set level (greater than 1 tonne per annum), information regarding acute and repeated-dose toxicity, skin and eye irritation, skin sensitization and genotoxicity is necessary. Testing to identify any respiratory sensitization hazard is not required, although structure-activity considerations may lead to classification as sensitizing and assignment of R42 (May cause sensitization by inhalation), as described previously for isocyanates. There is also the option to apply the safety phrase S22 ( Do not breathe dust ) in the absence of R42, and this has been done, for example, with certain new, dusty chlorotriazinyl dyestuffs. 

Heterocyclic halogen-containing groups other than dichlorotriazinyl and chlorotriazinyl have been used in the preparation of reactive dyes. The Reactone and Drimarine colours are substitution products of tetrachloro-pyrimidine, (9), and therefore contain a trichloropyrimidyl group in the molecule, (10). An example of such a dyestuff is Reactone Red 2B, (11). 

The choice, until recently, has been between a disperse dye with wetfastness which is not all that could be desired, accompanied by coverage of yarn variations, and faster colours which show up differences in physical and chemical properties of the polymer. When, in 1959, I.C.I. placed the Procinyl dyes on the market an advance of considerable importance was made. They are reactive dyes based on disperse dyestuff molecules containing chlorotriazinyl groups. Under neutral conditions the pattern of behaviour is that of a disperse dye and yarn irregularities are covered up to a great extent. When alkali is added to the dyebath, fixation takes place, giving wet-fastness of a high order. 

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