Pad-dyeing of cellulose fibers with sulfur black dyes: mixture of dithionite and glucose reducing sugar as reducing agent in aqueous alkaline dye bath

US5234465A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Manfred Hahnke · Kelkheim, DE
• Ullrich Saalfrank · Eppstein, DE
• Claus Schuster · Hofheim, DE
• Joachim Steinbach · Frankfurt, DE
• Gerd Krauzpaul · Liederbach, DE

Key dates

• Filing date: Jan 29, 1992
• Grant date: Aug 10, 1993
• Expiry date: Jan 29, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S8/918
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

Cellulose fibers are dyed ecologically soundly with sulfur black dyes by the pad-dyeing process by avoiding sulfides as reducing agent by replacing them by a dithionite-based mixture with at least one reducing sugar. A high color yield, a deep black shade and good reproducibility are ensured. The preferred reducing sugar is glucose.