Batchwise dyeing of cellulosic textile material with indigo by the exhaust method
AssigneeBASF SE
InventorsRudolf Kruger, Gert Rainer Kuhnel, Georg Schnitzer
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Abstract
The disclosure is a process for batchwise dyeing of cellulosic textile material with indigo by the exhaust method, which comprises applying the reduced indigo to the textile material from an aqueous dyeing liquor which includes a reductant, an alkali and additionally a further dissolved alkali metal salt in a concentration of from 200 to 350 g/l as electrolyte and whose pH has been set to 10.2-11.3, oxidizing the reduced indigo on the fiber back to the pigment while maintaining the high electrolyte concentration, and finishing the dyeing in a conventional manner.
Claims13
A process for batchwise dyeing of cellulosic textile material with indigo by the exhaust method, which comprises applying a reduced indigo to a textile material from an aqueous dyeing liquor which comprises a reductant, an alkali and additionally a further dissolved neutral alkali metal salt in a concentration of from 200 to 350 g/l as electrolyte and whose pH has been set to 10.2-11.3, oxidizing said reduced indigo on a fiber to a pigment while maintaining said electrolyte concentration, and finishing said dyeing in a conventional manner
- wherein said reductant is sodium dithionite.
Dependencies are inferred from the claim text.