Agfa-gevaert Ag

Gertrud Kirchhoff

Immo Boie

Karl Kuffner

Karl-Wilhelm Schranz

Helmut Haseler

Ernst Meier

Wolfgang Lassig

Herbert Stark

White couplers which are capable of reacting with color developer oxidation products to form colorless end product with the consumption of four oxidation equivalents and which, therefore have increased absorption capacity for color developer oxidation products correspond to the formula ##STR1## or its tautomeric form, in which R.sup.1 is hydrocarbyl, heterocyclyl attached through a ring carbon, or --CO--R.sup.2 R.sup.2 is alkyl, aryl, alkoxy, amino X is --S-- or --NR.sup.3 -- R.sup.3 is hydrogen, same as represented by R.sup.1 or an electron-attaching group. The four-equivalent white couplers may be contained in processing solutions or, in diffusion resistant form, in one or more layers of a colorphotographic material.

Process for the production of color photographic images using new white

Desirable 2-equivalent yellow-forming couplers in which a 1,3-diazolone-2-ring as splittable group is attached by the nitrogen in its 1-position to the coupling position of the 2-equivalent yellow-forming coupler and in which the diazolone ring has a C.dbd.C double bond adjacent to the nitrogen atom in its 1-position, have improved photographic properties in particular with respect to improved reactivity on chromogenic development and improved stability of the couplers as well as the dyes produced from them on chromogenic development in a photographic material which has been subjected to storage under moist and/or warm conditions.

2-Equivalent yellow couplers

Growing community of inventors

Leverkusen, Germany

Gertrud Kirchhoff