Photographic recording material
AssigneeAgfa-Gevaert
InventorsWalter Puschel, Heinrich Odenwalder, Erwin Ranz
Life of this patent
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Abstract
Traces of free inhibitors for the development of silver halide which might be present as impurities of inhibitor releasing compounds or which might be prematurely released therefrom because of insufficient stability thereof during storage of the photographic material are scavenged by compounds which are capable of binding free inhibitors at pH values below 7 but to a much less extent at pH values higher than 9.
Claims4
A photographic recording material comprising at least one light-sensitive silver halide emulsion layer and containing in at least one layer a nondiffusible compound which is capable of releasing a diffusible development inhibitor under the conditions of alkaline development of silver halide,
- wherein the improvement comprises said non-diffusible compound containing layer contains a non-diffusible development inhibitor releasing compound which releases mercapto development inhibitors and contains a scavenging compound which is capable of binding free mercapto development inhibitor at pH values below 7 but is capable of scavenging free mercapto development inhibitor to a much less extent at pH values from 9 to 13 and
- wherein the scavenging compound corresponds to the following formula ##STR6## in which R.sup.1 and R.sup.2 represent each individually hydrogen or a substituent selected from the group consisting of alkyl groups, aryl groups, hydroxy, alkoxy groups, --NR-alkyl and --NR-aryl groups, wherein R represents hydrogen or alkyl;
- or both R.sup.1 and R.sup.2 together complete a 5-or 6-membered carbocyclic or heterocyclic ring;
- R.sup.3 and R.sup.4 represent each individually hydrogen or a substituent selected from the group consisting of alkyl groups, alkoxy groups, aryl groups, halogen atoms, alkoxy carbonyl groups and cyano;
- n=0 or 1.
Dependencies are inferred from the claim text.