Photographic element containing pyrazolone pug releasing coupler and imaging process employing same
US5670306A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1996 |
| Grant date | Sep 23, 1997 |
| Priority date | — |
| Expiry date | Oct 15, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/158
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention provides a photographic element comprising a light-sensitive silver halide emulsion layer having associated therewith a 1-aryl-2-pyrazolin-5-one coupler bearing a 4-aryloxy coupling-off group containing a group capable of releasing a photographically useful group (PUG) wherein: (1) the 1-aryl-2-pyrazolin-5-one ring contains a 3-cyano substituent or a substituent linked to the 3-position by an acyl group, thio group, sulfoxide group, sulfone group, or a tetrahedral carbon atom which tetrahedral carbon atom has bonded thereto three other atoms or substituent groups for which the sum of the .sigma.* values is at least 1.5; and (2) the 4-aryloxy coupling-off group: PA1 (a) contains ring substituents selected so that the sum of the Hammett's sigma constants for all substituents on the aryloxy ring is at least 0.3 but does not contain a nitro substituent in the position ortho to the oxygen atom bonded to the pyrazolone ring; and PA1 (b) contains (i) in at least one position ortho or para to the oxygen atom bonding the aryloxy group to the pyrazolone ring comprising a tetrahedral carbon atom bonded to a PUG or to another timing group which timing group is in turn bonded to a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.