Photographic compounds
US4946964A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1987 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | Dec 11, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/55
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
There is described a photographic system wherein development of an exposed photosensitive element with an aqueous alkaline photographic developing composition is effected in the presence of a compound represented by the formula ##STR1## wherein R is --OH, --OR.sub.4, --NH.sub.2 --NHR.sub.5 or --NR.sub.4 R.sub.6 ; R.sub.1 is hydrogen, --NH.sub.2, alkyl, substituted alkyl, aryl or substituted aryl; R.sub.2 and R.sub.3 each independently is hydrogen, alkyl, aralkyl or aryl; R.sub.4 is a protecting group which can be removed in the presence of a base; R.sub.5 is an activating group which can render the neighboring hydrogen atom acidic; R.sub.6 is an electron withdrawing group which is capable of stabilizing the negative charge on the nitrogen atom which is produced upon removal of R.sub.4 upon contact with alkali; and PHOTO is a photographically useful group. The compounds provide controlled release of the photographically useful group by a base-catalyzed elimination when contacted by the aqueous alkaline processing composition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.