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US3772017A
Expired / Lapsed
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Diazo-type developing process
Assignee: Kalle GmbH and Co KG
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Filing: 1971-01-25
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Granted: 1973-11-13
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Expires: 1991-01-25
Abstract
Abstract A diazo-type developing process, for light sensitive imaging material comprising a diazonium compound, employs a developer solution including an azo coupler compound and sodium sulfite. Contacting the exposed diazo-type material with the solution converts the image-wise disposed light-sensitive diagzonium compound to a diazo sulfonate, and subsequent heating effects development of an azo dye image while drying the sheet. The developer solution is resistant to oxidation and exhibits an extended useful life.
Inventors
- 👤 M Reichel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:14
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
3 words
aminoacetic acid, and
Claim 2
Dependent Claim
24 words
an alkali sulfite salt, and d. heating said moistened composition in excess of about 100* C, thereby effecting formation of an azo dye image.
Claim 3
Dependent Claim
14 words
An imaging process according to claim 1 wherein said sulfite salt is sodium sulfite.
Claim 4
Dependent Claim
30 words
thiourea; b. exposing said coating imagewise to light thereby forming an image-wise disposition of said composition on said support; c. moistening said image-wise disposed composition with an acidic solution comprising:
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |