Supersensitising dyes

Abstract

Abstract Photographic silver halide emulsions containing a supersensitizing combination comprising a dye of the formula: WHERE R4, R6, R7, R8, R10, R11 and X have the meanings assigned to them above, R12 is an alkyl group, R13 is selected from the same class consisting of hydrogen and alky, R14 is selected from the class consisting of an alkyl group and a group A-Q where A is selected from the class consisting of straight and branched alkylene chains containing 1 to 6 carbon atoms and Q is selected from the class consisting of an amide, a carbonyl, and a sulfonic acid group, R15 and R16 are each selected from hydrogen, halogen, alkyl, aryl, alkoxy and hydroxy groups. A third dye may also be used in the combination. WHERE Y and Z are selected from the class consisting of sulfur and selenium, at least one of the groups R1 and R3 are alkyl, the other groups being selected from the class consisting of alkyl, carboxyalkyl, carbamoylalkyl and sulphoalkyl, R2 is selected from the class consisting of hydrogen and alkyl, at least one of the groups R5 and R9 is a thienyl group, the other groups R5 and R9 being selected from the class consisting of hydrogen, halogen, alkyl, aryl, hydroxy and alkoxy groups and together with either R4 or R8, depending on whether R5 or R9 carries the thienyl substituent group form part of a benzene ring, R4 and R8 taken separately each represent a hydroxy atom, R6 and R10 taken separately are each selected from the class consisting of a hydrogen atom, a halogen atom, an alkyl, aryl, hydroxy and alkoxy groups, R7 and R11 taken separately each represent a hydrogen atom, R6 and R7 taken together form part of a benzene ring, R10 and R11 taken together form part of a benzene ring and X is an anion, together with a dye of the formula:

Inventors

• 👤 Douglas James Fry
• 👤 Geoffrey Ernest Ficken
• 👤 Ronald William Burrows
• 👤 Simon Lindsay Scrutton

Bibliographic Details