Patent US2498418A successfully refreshed from Google Patents.
US2498418A
Expired / Lapsed
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Production of azo dyestuff images from n-acyl-n-aryl hydrazine developers
Assignee: GAF Chemicals Corp
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Filing: 1948-05-18
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Granted: 1950-02-21
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Expires: 1968-05-18
Abstract
No abstract record available.
Inventors
- 👤 William E Hanford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:42
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/30
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
78 words
THE PROCESS OF PRODUCING AZO DYESTUFF IMAGES IN A PHOTOGRAPHIC ELEMENT WHICH COMPRISES DEVELOPING A REDUCIBLE SILVER SALT IMAGE SELECTED FROM THE CLASS CONSISTING OF REDUCIBLE SILVER HALIDE AND SILVER FERROCYANIDE WITH AN ASYMMETRICAL NACYL-N-ARYL HYDRAZINE IN WHICH A TERMINAL GROUP IS PRIMARY AMINO WHILE REACTING THE OXIDATION PRODUCTS PRODUCED FROM SAID N-ACYL-ARYL-HYDRAZINE BY SUCH DEVELOPMENT WITH A NON-QUINONE-FORMING PHENOL AS AN AZO DYE COUPLING COMPONENT TO PRODUCE AN AZO DYESTUFF IN SITU WITH THE RESULTING METAL IMAGE.
Claim 2
Dependent Claim
78 words
THE PROCESS OF PRODUCING AZO DYESTUFF IMAGES IN A PHOTOGRAPHIC ELEMENT WHICH COMPRISES DEVELOPING A REDUCIBLE SILVER SALT IMAGE SELECTED FROM THE CLASS CONSISTING OF REDUCIBLE SILVER HALIDE AND SILVER FERROCYANIDE WITH AN ASYMMETRICAL NACYL-N-ARYL HYDRAZINE IN WHICH A TERMINAL GROUP IS PRIMARY AMINO WHILE REACTING THE OXIDATION PRODUCTS PRODUCED FROM SAID N-ACYL-ARYL-HYDRAZINE BY SUCH DEVELOPMENT WITH A NON-QUINONE-FORMING PHENOL AS AN AZO DYE COUPLING COMPONENT TO PRODUCE AN AZO DYESTUFF IN SITU WITH THE RESULTING METAL IMAGE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-02-20 | 1953-08-22 | 1954-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-02-20 | 1957-08-22 | 1958-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-02-20 | 1961-08-22 | 1962-02-21 | $7700.00 | Window Closed / Lapsed |