Azopyrazolone masking couplers
US5492799A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1994 |
| Grant date | Feb 20, 1996 |
| Priority date | — |
| Expiry date | Jun 22, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/3335
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The invention provides a photographic element comprising a support bearing a light-sensitive photographic silver halide layer having associated therewith a masking coupler comprising: PA1 (1) a parent group containing a -1-phenyl-3-anilinopyrazolin-5-one having electron-withdrawing substituents on the phenyl and anilino rings of a type and number sufficient to provide a combined Hammett sigma(para) value for such substituents of at least 1.4; PA2 (2) a coupling-off group at the 4 position of the pyrazolone of the parent group comprising an arylazo dye containing on the aryl ring the following: PA3 (A) a substituent para to the azo functionality selected from the group consisting of hydroxyl, and alkoxy, carbonamido, and sulfonamido, each unsubstituted or substituted with nonaromatic groups, and PA3 (B) "n" additional substituents selected from the group consisting of alkyl, alkoxy, carbonamido, and sulfonamido, unsubstituted or substituted with nonaromatic groups, where "n" is 0 to 4; PA3 provided that substituent (A) and a substituent (B) may form a ring PA3 wherein one of the substituents (A) or (B) contains an alkyl group of at least 8 carbon atoms, unsubstituted or substituted …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.