Photographic layers
Abstract
Abstract Dyes having the general formula <FORM:1002345/C4-C5/1> wherein R1 and R2 are benzine residues having the azo and -O-Cu-O- links in ortho position, the azo and azoxy groups being linked to R2 in para position, are prepared by condensing 1 mol. of 4,41-dinitro-stilbene-2,21-disulphonic acid with two mols. of an amino-azo dye of the formula HO3S-R1(OH)-N = N-R2(OCH3)-NH2 and then demethylating the methoxy groups and metallizing with a copper compound. The amino-azo dye is itself prepared by coupling the diazonium salt of an o-hydroxyamine of the formula HO3S-R1(OH)-NH2 with an amine of the formula H-R2(OCH3)-NH2. The benzene residue R2 may have additional substituents in para position to the methoxy group (i.e. to the -O-Cu-O-linkage in the final dye) such as methyl, methoxy or ethoxy substituents. The benzene residue R1 also may have additional substituents such as chloro, methyl, ethyl, nitro or further sulphonic acid groups.
Inventors
- 👤 Anderau Walter
Bibliographic Details
Claims Analysis
Total Claims: 1References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-10-11 | 1969-04-12 | 1969-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-10-11 | 1973-04-12 | 1973-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-10-11 | 1977-04-12 | 1977-10-12 | $7700.00 | Window Closed / Lapsed |