Class of compounds which increases and stabilizes photographic speed
US5500333A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 1993 |
| Grant date | Mar 19, 1996 |
| Priority date | — |
| Expiry date | Dec 16, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention is generally accomplished by providing a method of finishing an emulsion comprising providing silver halide grains, adding to said emulsion in an amount between about 0.005 mmol/per mole of silver and 0.10 mmol/per mole of silver of the compound ##STR1## X=O, S, Se; R.sub.1 =alkyl or substituted alkyl or aryl or substituted aryl; PA1 Y.sub.1 and Y.sub.2 individually represent hydrogen, alkyl groups or an aromatic nucleus or together represent the atoms necessary to complete a cyclic structure containing carbon, oxygen, selenium, or nitrogen atoms necessary to complete a fused aromatic nucleus or an alicyclic structure. The invention also provides a photographic element comprising the silver halide emulsion. In a preferred embodiment, the R.sub.1 substituent is methyl or phenyl.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.