Weakly alkaline ascorbic acid developing composition, processing kit and method using same
US5702875A · kind A · utility
6Cited by
18References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 28, 1996 |
| Grant date | Dec 30, 1997 |
| Priority date | — |
| Expiry date | Jun 28, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2200/44
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A black-and-white developing composition includes as ascorbic acid developing agent, an auxiliary super-additive developing agent, borate buffer and a preservative. The composition pH is from 7 but less than 9. The composition can be formulated from two separately packaged parts that may be in dry or liquid form. The borate buffer is present to maintain the desired pH, and the two developing agents are present in desired molar ratios for optimal developing activity. Improved photographic properties are obtained while avoiding the use of environmentally unfriendly dihydroxybenzenes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.