Process for preparing a direct positive photographic material
US5110719A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1990 |
| Grant date | May 5, 1992 |
| Priority date | — |
| Expiry date | Nov 13, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/141
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process for preparing a direct positive photosensitive material comprising providing on a support at least one silver halide light-sensitive emulsion layer containing the combination of (a) non-prefogged internal latent image silver halide grains; (b) a binder; (c) at least one compound represented by formulae (I), (II), or (III); and at least one compound represented by formula (IV): EQU R--SO.sub.2 S--M (I) EQU R--SO.sub.2 S--R.sup.1 (II) EQU R--SO.sub.2 S--L.sub.m --S.O.sub.2 S--R.sup.2 (III) wherein R, R.sup.1 and R.sup.2 each represents a substituted or unsubstituted aliphatic group, a substituted or unsubstituted aromatic group or a substituted or unsubstituted heterocyclic group; M represents a cation; L represents a divalent linking group; and m is 0 or 1; and EQU R.sup.3 --SO.sub.2 --M.sup.1 (IV) wherein R.sup.3 represents an aliphatic group, an aromatic group or a heterocyclic group; and M.sup.1 represents a cation. The material provides a direct positive image with high Dmax, low Dmin and high contrast.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.