| abstract |
1,064,193. Hypersensitized silver halide emulsions. FILMFABRIK WOLFEN VEB. June 9, 1964, No.23926/64. Heading G2C. Hypersensitized silver halide emulsions contain (a) a dye of formula wherein R1, R2 and R3 are alkyl, aralkyl, hydroxyalkyl, carboxyalkyl, sulphoalkyl and sulphatoalkyl groups; R4 is an alkyl, aryl, aralkyl or cycloalkyl group; L is an optionally substituted methine group; Z1 and Z2 complete a 5- or 6-membered heterocyclic ring; X is an anion; n1, n2 are 0 or 1; m1 is 1 or 2; and m2 is 0-3; (b) an aromatic amine of formula R5-NH-A-NH-R6 wherein R5 and R6 are acyl, carbamyl or s-triazinyl groups and A is an aromatic radical optionally substituted by sulpho groups, and (c) a reducing agent of formula in which the OH groups may be esterified, Z3 completes a benzene y-lactone, tetronamide, pyronimide, furane or pyrrole ring; L is a methine group; and n3 is 0 or 1, or a complex thereof. |