Photographic elements containing ballasted electron-accepting nucleophilic displacement compounds
US4139379A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1977 |
| Grant date | Feb 13, 1979 |
| Priority date | — |
| Expiry date | Mar 7, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C8/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Photographic elements, processes for forming images in photographic elements and new compounds are disclosed. Generally, the invention relates to ballasted electron-accepting nucleophilic displacement compounds; after acceptance of at least one electron (reduction) by a nucleophile precursor group, the compounds are capable of undergoing intramolecular nucleophilic displacement to release a diffusible moiety, such as an image dye or a photographic reagent. In certain embodiments, the ballasted electron-accepting nucleophilic displacement compounds are used in combination with electron donors and electron-transfer agents. The processes disclosed are particularly useful in providing positive transfer images using negative-working silver halide emulsions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.