Photographic silver halide developer compositions and process for forming photographic silver images
US5545508A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 1996 |
| Grant date | Aug 13, 1996 |
| Priority date | — |
| Expiry date | Feb 13, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C5/305
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process for forming a black-and-white high contrast negative photographic silver image by development of a silver halide photographic element with an aqueous alkaline photographic developer composition comprising a dihydroxybenzene developing agent, an auxiliary superadditive developing agent, an antifogging agent, an antioxidant compound, a combination of buffering agents and a sequestering agent, characterized by the fact that: a) the auxiliary developing agent is an aminophenol compound, b) the combination of buffering agents comprises at least a first buffering agent represented by carbonate compounds and at least a second buffering agent represented by phosphate compounds, the total amount of said first buffering agent and said second buffering agent being at least 35 grams per liter, band c) the pH of said aqueous alkaline photographic developer composition is in the range 9.0 to 11.0.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.