Spectral sensitization of direct positive silver halide emulsions

Abstract

Abstract 5-((1-R7,2,3-(-Z-),5-R6-PYRROLIUM-4-YLIDENE)=CH-)THIOPHENE WHEREIN: A DIRECT-POSITIVE SILVER HALIDE EMULSION COMPRISING FOGGED SILVER HALIDE IS DESCRIBED WHEREIN SAID EMULSION IS SPECTRALLY SENSITIZED BY MEANS OF A DYE CORRESPONDING TO ONE OF THE FORMULAE: (2-(R1-N(-R2)-),3-R3,4-R4-THIOPHEN-5-YL)-(L1=L2)M-C<(-Z1- N(-R5)=CH-CH=) X(-), AND 2-(R1-N(-R2)-),3-R3,4-R4, EACH OF R1 AND R2 REPRESENTS C1-C5 ALKYL OR TOGETHER REPRESENT THE ATOMS NECESSARY TO COMPLETE A MORPHOLINE, PIPERIDINE, OR PYRROLIDINE RING, EACH OF R3 AND R4 REPRESENTS HYDROGEN, AN ALKYL GROUP OR AN ARYL GROUP, EACH OF L1 AND L2 REPRESENTS A METHINE GROUP, N REPRESENTS 0 OR 1, M REPRESENTS 1 OR 2, EACH OF R5 AND R7 REPRESENTS A SATURATED OR UNSATURATED ALIPHATIC GROUP OR AN AROMATIC GROUP, R6 REPRESENTS AN ARYL GROUP, OR A HETEROCYCLIC AROMATIC GROUP, Z1 STANDS FOR THE NON-METALLIC ATOMS NECESSARY TO COMPLETE A 5- OR 6-MEMBERED HETEROCYCLIC NUCLEUS CONTAINING NITROGEN, WHICH NUCLEUS MAY CARRY A FUSEDON BENZENE OR NAPHTHALENE RING, Z2 REPRESENTS THE ATOMS NECESSARY TO COMPLETE A FUSED-ON BENZENE RING, AND X STANDS FOR AN ANION BUT IS NOT PRESENT WHEN L1, L2, L5, OR R7 CONTAINS AN ANIONIC GROUP.

Inventors

• 👤 H Depoorter
• 👤 F Moelants

Bibliographic Details