Global Patent Index - EP 0321839 A3

EP 0321839 A3 19900404 - BLEACHING BATH WITH BLEACH ACCELERATING SUBSTANCES

Title (en)

BLEACHING BATH WITH BLEACH ACCELERATING SUBSTANCES

Publication

EP 0321839 A3 19900404 (DE)

Application

EP 88120873 A 19881214

Priority

DE 3743783 A 19871223

Abstract (en)

[origin: EP0321839A2] Bleaching baths and bleach-fixing baths, which contain an iron(III) ion complex salt as bleaching agent and additionally a 5- to 7-membered heterocyclic compound which contains at least one N atom and at least one further hetero atom from the series O, N, S and which is substituted by -S<(-)> and carries a positive charge on the quaternary ring nitrogen atom, arranged in such a way that no tautomeric charge compensation to give a neutral thione form is possible, ensure, due to an excellent bleaching rate and simultaneously good stability, good bleaching in colour materials within the usual processing times, that is to say they ensure blackening without residual silver in colour negative materials and low minimum densities in colour reversal materials.

IPC 1-7

G03C 7/42

IPC 8 full level

G03C 7/42 (2006.01)

CPC (source: EP US)

G03C 7/421 (2013.01 - EP US)

Citation (search report)

Designated contracting state (EPC)

BE DE FR GB

DOCDB simple family (publication)

EP 0321839 A2 19890628; EP 0321839 A3 19900404; EP 0321839 B1 19921111; DE 3743783 A1 19890713; DE 3875930 D1 19921217; JP H01201659 A 19890814; US 4939075 A 19900703

DOCDB simple family (application)

EP 88120873 A 19881214; DE 3743783 A 19871223; DE 3875930 T 19881214; JP 31968488 A 19881220; US 28212188 A 19881209