Method for forming a direct positive image
US4968596A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1988 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Nov 2, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/141
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for forming a direct positive image comprising the steps of: PA1 (a) imagewise exposing a photographic light-sensitive material composed of a support having thereon at least one unprefogged internal latent image type silver halide light-sensitive emulsion layer; and PA1 (b) developing the exposed photographic light-sensitive material to form a direct positive image in the presence of at least one nucleating agent represented by formula (N-I); ##STR1## wherein Z.sup.1 represents nonmetal atomic group necessary for forming a 5-membered or 6-membered heterocyclic ring, a 5-membered or 6-membered heterocyclic ring fused with an aromatic ring, or a 5-membered or 6-member heterocyclic ring fused with another heterocyclic ring; R.sup.1 represents an aliphatic group; X represents ##STR2## Q represents a nonmetallic atomic group necessary for forming a 4-membered to 12-membered nonaromatic hydrocarbon ring or a 4-membered to 12-membered nonaromatic heterocyclic ring; provided that at least one of R.sup.1, Z.sup.1 and Q is substituted with an alkynyl group; Y represents a counter ion required for charge balance; and n is a number required for charge balance; or Z.sup.1 contains a he…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.