Water-soluble sulphur dyes, their preparation and use

US5383961A · kind A · utility

Assignee

• Cassella Aktiengesellschaft · DE

Inventors

• Wolfgang Bauer · Krefeld, DE
• Gert Nagl · Niederdorfelden, DE
• Willi Steckelberg · Hofheim, DE
• Josef Ritter · Graz, AT
• Wilhelm Mauelshagen · Bad Camberg, DE

Key dates

• Filing date: Sep 30, 1993
• Grant date: Jan 24, 1995
• Expiry date: Sep 30, 2013

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09D11/328
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The black water-soluble sulphur dyes of the formula ##STR1## in which, for example, F is the dye chromophore of C.I. Leuco Sulphur Black 1, PA1 R.sup.1 if hydrogen, alkyl, PA1 M.sym. is an alkali metal cation and PA1 n is such a large number that the dye contains 5 to 20% by weight of COO.sup..crclbar. groups are, inter alia, outstandingly suitable for producing recording fluids.