Photographic developing solution containing an ascorbic acid derivative
US5196298A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 5, 1992 |
| Grant date | Mar 23, 1993 |
| Priority date | — |
| Expiry date | Feb 5, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C5/30
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A photographic developing solution for immersion development is disclosed showing a pH of at least 12.0 and containing more than 0.4 moles/liter of a sugar derivative, or an alkali metal salt thereof, corresponding to general formula (I): ##STR1## wherein X represents an oxygen atom or an imino group, and n represents a positive integer from 1 to 4, and R represents a hydroxy group when n is 1, and R represents a hydroxy group or a hydrogen atom when n is 2 to 4. Preferred sugar derivatives according to the present invention are l-ascorbic acid and iso-ascorbic acid. In a most preferred embodiment there are substantially no other developing agents and no sulphite ions present. When developing a graphic arts photographic material lith quality is obtained. The disposal of depleted solutions can be performed in an ecologically safe way.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.