The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 19, 1981
Filed:
Aug. 28, 1979
Paul Tschopp, Dudingen, CH;
Ciba-Geigy AG, Basel, CH;
Abstract
Light-sensitive recording material for color photography, which contains, in at least one silver halide emulsion layer, at least one yellow coupler of the formula ##STR1## in which R.sub.1 is alkyl, R.sub.2 is alkyl or aryl and R.sub.3 is substituted or unsubstituted alkyl, alkoxy or alkylmercapto, cycloalkylmercapto, aryl, aryloxy or arylmercapto, the sum of the carbon atoms in the substituents R.sub.1, R.sub.2 and R.sub.3 being 3 to 30 and at least two of these substituents being able to form a cyclic radical together with the carbon atom to which they are bonded, the R.sub.4 s are each halogen, alkyl, alkoxy, halogenoalkyl, alkylsulfonyl or aryloxy, X is a radical detachable during the coupling reaction, A is a 5-membered, heterocyclic, unsaturated ring system which contains 2 or 3 hetero-atoms, at least one of which is a nitrogen atom, and can be fused with a benezene ring and which is substituted by at least one ballast group and r is 1 or 2. The yellow couplers show high reactivity (high maximum density), which makes possible accelerated processing of the photographic materials, and minimal fogging. The couplers also have good fastness to light.