Fixing bath

US5856074A · kind A · utility

Assignee

• Agfa-Gevaert NV · BE

Inventors

• Gustav Tappe · Leverkusen, DE
• Norman Klaunzer · Leverkusen, DE

Key dates

• Filing date: Oct 17, 1997
• Grant date: Jan 5, 1999
• Expiry date: Oct 17, 2017

Classification

• Technology area (CPC G): Physics
• CPC primary: G03C5/38
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

This invention relates to a fixing bath containing a biologically degradable complexing agent of formula I ##STR1## wherein R.sup.1-4 represents hydrogen, C.sub.1 -C.sub.10 -alkyl, hydroxy-C.sub.1 -C.sub.10 -alkyl, C.sub.1 -C.sub.10 -alkoxy-C.sub.1 -C.sub.10 -alkyl, carboxy-C.sub.2 -C.sub.10 -alkyl, dicarboxy-C.sub.1 -C.sub.10 -alkyl, carboxy-hydroxy-C.sub.1 -C.sub.10 -alkyl, hydroxy-C.sub.1 -C.sub.5 -alkyl-(oxy-C.sub.1 -C.sub.5 -alkyl).sub.n, or C.sub.1 -C.sub.5 -alkoxy-C.sub.1 -C.sub.5 -alkyl-(oxy-C.sub.1 -C.sub.5 -alkyl).sub.n, PA1 M represents hydrogen, lithium, sodium, potassium or ammonium, and PA1 n represents 1, 2, 3 or 4, the iron(III) complex salt of which does not impede electrolytic desilverisation during the regeneration of spent fixing bath.