Patent US3736166A successfully refreshed from Google Patents.
US3736166A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat reactive transparent copy sheet
Assignee: Arkwright-Interlaken Inc
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Filing: 1971-04-07
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Granted: 1973-05-29
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Expires: 1991-04-07
Abstract
Abstract A TRANSPARENT COPY SHEET CAPABLE OF ACQUIRING A STABLE COLOR IN SELECTED REGIONS CONTRASTING WITH THE BACKGROUND COLOR OF THE SHEET UPON EXPOSING THESE REGIONS TO AN ELEVATED TEMPERATURE, COMPRISING A TRANSPARENT SUBSTRATE AND A COATING COMPRISING (1) NINHYDRIN, (2) AN ORGANIC AMINO COMPOUND CONTANING AT LEAST ONE AMINO GROUP SELECTED FROM THE CLASS CONSISTING OF PRIMARY AND SECONDARY AMINES, AND WHICH IS NORMALLY REACTIVE WITH NINHYDRIN AT TEMPERATURES BELOW THIS ELEVATED TEMPERATURE TO FORM A DYE, AND (3) A SELECTED SUBSTITUTED UREA OR THIOUREA STABILIZER.
Inventors
- 👤 W Lawton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 00:41
CPC Classifications
B; B41; B41M; B41M5/00; B41M5/26; B41M5/30; Y; Y10; Y10S; Y10S428/00; Y10S428/913
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |