Direct-positive silver halide photographic sensitive materials
US4273862A · kind A · utility
14Cited by
13References
17Claims
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Key dates
| Filing date | Sep 24, 1979 |
| Grant date | Jun 16, 1981 |
| Priority date | — |
| Expiry date | Sep 24, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/15
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Direct-positive silver halide photographic sensitive materials of high sensitivity and capable of forming a high-contrast image are obtained by incorporating anion-type cyanine dyes having a polarographic oxidation halfwave potential not less positive than +0.4 V in externally fogged direct-positive silver halide emulsions containing not less than 70 mole-% of bromide. Additional incorporation of a development accelerator such as 2-mercaptoimidazoline improves developability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.