Photographic silver halide emulsions
US4039335A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1976 |
| Grant date | Aug 2, 1977 |
| Priority date | — |
| Expiry date | Oct 29, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/29
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A silver halide photographic emulsion spectrally sensitized with a combination of sensitizing dyes consisting essentially of at least one sensitizing dye represented by the following general formula [I] and at least one sensitizing dye represented by the following general formula [II] in supersensitizing amounts: ##STR1## wherein R.sup.1 and R.sup.2 each is an alkyl group, R.sup.3 is an alkyl group, X.sub.1 is an acidic anion, m is 1 or 2, and m is 1 when the dye forms an intramolecular salt (betaine-like structure). ##STR2## WHEREIN Z.sup.1 is a sulfur atom or a selenium atom, Z.sup.2 is an atomic group necessary to form a benzothiazole ring, a benzoselenazole ring, a naphtho[1,2-d]thiazole ring or a naphtho[1,2-d]selenazole ring, R.sup.4 and R.sup.5 is an alkyl group, R.sup.6 is an alkyl group, a phenyl group, an aralkyl group, a furyl group or a thienyl group, X.sub.2 is an acidic anion, n is 1 or 2, and n is 1 when the dye forms an intramolecular salt (betaine-like structure).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.