Uniformly mixed dry photographic developing composition containing antioxidant and method of preparation
US5945265A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 1998 |
| Grant date | Aug 31, 1999 |
| Priority date | — |
| Expiry date | Mar 26, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C5/305
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A powdered, uniformly mixed photographic developing composition is prepared with intense mixing of dry photoprocessing chemical components, one of which is a photographic developing agent, and by forming uniformly sized agglomerates of the mixed powder. During agglomeration, a solution of a binder material is applied in a controlled manner to enable the mixed powder particles to stick together but without leaving much residue in the final composition. With this process, the mixed powder and agglomerates each have desired uniformity in size and chemical composition. The resulting dry uniformly mixed developer composition is highly stable, dissolvable and substantially free of dust. An antioxidant is also applied to the dry uniform mixture during agglomeration to reduce the loss of developing agent activity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.