Patents Assigned to Ajfa-Gevaert AG
  • Patent number: 5731133
    Abstract: The storage stability of photographic color images obtained by chromogenic development may be improved by compounds of the formula I, which are capable of reacting with primary amines, in particular color developer compounds (reagent for primary amines). The compounds of the formula may be added to the color photographic recording material or to a treatment bath downstream from color development. Compounds of the formula I are moreover suitable as an additive to a spent photographic processing bath or its overflow in order to reduce therein the content of color developer compounds before the processing bath or the overflow is disposed of or regenerated for further use. ##STR1## In formula I: A means --OR.sup.2, --SR.sup.2 or --NR.sup.2 R.sup.3 ;R.sup.1 means H, alkyl, aryl, acyl, sulphonyl or a residue as in A or a residue which, together with A or together with Z.sup.1, completes a ring;R.sup.2 means H, alkyl, aryl, acyl, sulphonyl;R.sup.3 means a residue as in R.sup.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: March 24, 1998
    Assignee: Ajfa-Gevaert AG
    Inventors: Thomas Hubsch, Arno Schmuck