Photographic element containing a stable aryloxypyrazolone coupler and process employing same
US5576167A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1994 |
| Grant date | Nov 19, 1996 |
| Priority date | — |
| Expiry date | Dec 30, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/156
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A photographic element comprises a light-sensitive silver halide emulsion layer having associated therewith a coupler based on a 1-aryl-2-pyrazolin-5-one ring and represented by formula I: ##STR1## wherein: Ar.sup.1 and Ar.sup.2 are each independently aryl groups comprising a carboaromatic or heteroaromatic ring; X, Y, and Z are bonded to a carbon atom alpha to the 3-position and are independently selected from the group consisting of hydrogen and substituent groups such that the sum of the Taft .sigma.* values for X, Y, and Z is at least 1.5; R represents n independently selected substituent groups bonded to the Ar.sup.2 ring, provided that the sum of the appropriate Hammett .sigma. constants for all R substituent groups is at least 0.3, and provided further that two of X, Y, and Z may join to form a ring; and n is 0 to 5; provided that R may not be a nitro group ortho to the oxygen atom bonding Ar.sup.2 to the 1-aryl-2-pyrazolin-5-one ring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.