Photographic element with 2-equivalent 5-pyrazolone and competitor for oxidized developing agent
US5147764A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 30, 1991 |
| Grant date | Sep 15, 1992 |
| Priority date | — |
| Expiry date | Apr 30, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/39236
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Photographic elements are described having PA0 a silver halide emulsion layer, PA0 a 2-equivalent 5-pyrazolone coupler is reactive association with said silver halide emulsion, and PA0 a competitor for oxidized developer in reactive association with said coupler having the formula: ##STR1## wherein R.sup.1 represents an electron donating group, PA1 R.sup.2 represents hydrogen, alkyl, alkoxy, aryl, aryloxy, aralkyl or amino of the formula --NHR.sup.3, where R.sup.3 is phenyl or benzyl, with the proviso that at least one ofthe substitutents R.sup.1 and R.sup.2 (a) represents (1) a ballast group of sufficient size as to render the hydrazide compound non-diffusible in the photographic element prior to development in alkaline processing solution and (b) comprises a polar group, and PA1 n is 0, 1 or 2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.