US3706537A
Expired / Lapsed
US
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Free radical ph indicators
Assignee: Synvar Associates
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Filing: 1971-02-22
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Granted: 1972-12-19
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Expires: 1991-02-22
Abstract
Abstract 1-(O-),2-((PYRID-2-YL)-CH(-CH3)-CH2-),3-((-)O-)-2- IMIDAZOLINIUM ACIDITY DETERINATIONS ARE MADE FROM VARIATIONS IN ELECTRON SPIN RESONANCE (ESR) SPECTRA WITH COMPOUNDS HAVING AN ASYMMETRIC CENTER BONDED THROUGH A METHYLENE GROUP TO AN ORGANIC FUNCTIONALITY HAVING AN UNPAIRED ELECTRON. ACCURATE DETERMINATION OF ACIDITY CAN BE MADE BY COMPARING THE SPECTRUM OF THE SAMPLE BEING MEASURED TO A STANDARD.
Inventors
- 👤 Jan Becher
- 👤 Edwin F Ullman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:44
CPC Classifications
C; C07; C07D; C07D213/00; C07D213/02; C07D213/04; C07D213/24; C07D213/44; C07D213/46; C07D213/51; G; G01; G01N; G01N31/00; G01N31/22; G01N31/221; Y; Y10; Y10T; Y10T436/00; Y10T436/24
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) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |