EP 0588408 B1 19980513 - An ascorbic acid type developer with a particular composition
Title (en)
An ascorbic acid type developer with a particular composition
Title (de)
Entwickler vom Ascorbinsäure-Typ und mit einer bestimmten Zusammensetzung
Title (fr)
Développateur du type acide ascorbique avec une composition déterminé
Publication
Application
Priority
EP 92202809 A 19920915
Abstract (en)
[origin: EP0588408A1] A developer solution for the development of photographic silver halide materials is disclosed comprising (1) an ascorbic acid type developing agent, and (2) a mixture of at least two 3-pyrazolidone type developing agents chosen from (a) 1-phenyl-3-pyrazolidone, (b) 1-phenyl-4-methyl-3-pyrazolidone), (c) 1-phenyl-4-methyl-4'-hydroxymethyl-3-pyrazolidone, (d) 1-phenyl-4,4'-dimethyl-3-pyrazolidone. In a preferred embodiment the ascorbic acid type developing agent is l-ascorbic acid or iso-ascorbic acid or a salt thereof, and the mixture of the 3-pyrazolidones consists of a mixture of 1-phenyl-3-pyrazolidone and 1-phenyl-4-methyl-3-pyrazolidone. The developer composition of the invention shows improved sensitometric stability against a pH decrease caused by exhaustive continuous processing without developer replenishment.
IPC 1-7
IPC 8 full level
G03C 5/30 (2006.01)
CPC (source: EP)
G03C 5/30 (2013.01)
Designated contracting state (EPC)
BE DE FR GB NL
DOCDB simple family (publication)
EP 0588408 A1 19940323; EP 0588408 B1 19980513; DE 69318498 D1 19980618; DE 69318498 T2 19981112
DOCDB simple family (application)
EP 93202545 A 19930831; DE 69318498 T 19930831