Merocyanine dye and a corbocyanine dye fogged direct positive silyer halide emulsion supersensitized with a

Abstract

Abstract A PHOTOGRAPHIC DIRECT-POSITIVE SILVER HALIDE EMULSION IS DESCRIBED WHEREIN THE SILVER HALIDE GRAINS HAVE A CENTRAL CORE OF SILVER HALIDE CONTAINING CENTERS PROMOTING THE DEPOSITION OF PHOTOLYTIC SILVER AND OVER SAID CORE AN OUTER SHELL OF FOGGED SILVER HALIDE AND WHEREIN SAID OUTER SHELL COMPRISES ABSORBED THERETO A 2-PYRIDINE-RHODANINE MEROCYANINE DYE OF FORMULA I AND A CARBOCYANINE DYE OF FORMULA II 1-R1,2-(2-(X=),3-R2,4-(O=)THIAZOLIDIN-5-YLIDENE)-1,2- DIHYDROPYRIDINE, AND X1<(-C(1)=C(2)-N(+)(-R3)=C(-CH= C(-R)-CH=C<(-X2-C(3)=C(4)-N(-R4)-))-) WHERE Z1 IS BETWEEN C1 AND C2 AND Z2 BETWEEN C3 AND C4 WHEREIN: R1, R2, R3 AND R4 REPRESENT A SATURATED OR UNSATURATED ALIPHATIC GROUP, A CYCLOALIPHATIC GROUP OR AN ARYL GROUP, X1 AND X2 REPRESENT OXYGEN, SULPHUR, SELENIUM OR N(R5) WHEREIN R5 HAS THE SIGNIFICANCE GIVE FOR R1-R4, Z1 AND Z2 REPRESENT THE ATOMS NECESSARY TO CLOSE A FUSEDON AROMATIC NUCLEUS OF THE BENZENE SERIES, R IS HYDROGEN, ALKYL, ARALKY, OR ARYL AND X IS AN ANION BUT DOES NOT EXIST WHEN ONE OF R3, R4, AND R5 CONTAINS AN ANIONIC GROUP. THE COMBINATION OF DYES USED HAS A SUPERSENSITIZING EFFECT ON THE EMULSION. THE TOTAL SPEED IS MARKEDLY INCREASED AS COMPARED WITH THE USE OF EITHER DYE ALONE AND LESS STAIN IS PRODUCED.

Inventors

• 👤 R Florens
• 👤 T Ghys

Bibliographic Details