Ciba-Geigy Corporation

Manfred Motter

Peter Moser

Pierre Galafassi

Ulrich Horn

Josef Koller

Manfred Herrmann

Joseph Koller

Rico Jenny

A process is described for the level di- and trichromatic dyeing of polyacrylonitrile materials or of blends containing polyacrylonitrile, which process comprises using for the dyeing an aqueous dyeing liquor which contains at least two dye mixtures, each dye mixture consisting of at least (a) one migrating cationic dye, the cation weight of which is less than 310, the parachor of which is less than 750 and the log P of which is less than 3.6, and (b) at least one non-migrating cationic dye, at least one parameter of which is outside the definition given under (a), and the components (a) and (b) being employed in a mixing ratio which is such that during the dyeing process the migrating and non-migrating dyes migrate on the fibre on tone. This produces, on polyacrylonitrile materials, dyeings which are distinguished by high levelness and high lightfastness.

Process for the level di- and trichromatic dyeing of polyacrylonitrile

Described is a process for the level dyeing of polyacrylonitrile materials of slow, normal and rapid absorptive capacity with an aqueous dye liquor, which process comprises using a liquor containing at least one migrating cationic dye as well as, if required, further additives; and adding to the liquor, before, during or after dyeing, at least one organic cationic migration auxiliary. This process renders possible by the use of organic migration auxiliaries the obtainment of level single-shade and, in particular, combination-shade dyeings at normal dyeing temperatures. Particularly suitable migrating cationic dyestuffs are those having a more or less delocalized positive charge, the cation weight of which dyestuffs is smaller than 310, the parachor smaller than 750 and the log P (relative lipophil property) smaller than 3.6. Particularly suitable organic migration auxiliaries are those of which the cation weight is smaller than 250, the parachor smaller than 700 and the log P smaller than 6.4.

Process for the level dyeing of polyacrylonitrile materials of slow,

Described is a process for the level dyeing of polyacrylonitrile materials, in which process there is used for dyeing polyacrylonitrile materials that have varying substantivity an aqueous dye liquor containing at least one migrating cationic dyestuff and electrolyte, as well as, optionally, at least one migrating cationic retarder and further additives. This process renders possible a level dyeing of all fibre types of polyacrylonitrile materials by one and the same dyeing method. Generally, no addition of a migrating cationic retarder is necessary. Only in the case of a light-colored dyeing is a very minor addition thereof required. Particularly suitable migrating cationic dyestuffs are those having a more or less delocalized positive charge, the cation weight of which dyestuffs is smaller than 310, the parachor smaller than 750 and the log P (relative lipophil property) smaller than 3.6.

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Aesch, Switzerland

Manfred Motter