Patent US4157320A successfully refreshed from Google Patents.
Patent US2623908A successfully refreshed from Google Patents.
US2623908A
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Process for making 4, 4'-isopropylidenediphenol
Assignee: Dow Chemical Co
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Filing: 1951-11-23
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Granted: 1952-12-30
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Expires: 1971-11-23
Abstract
No abstract record available.
Inventors
- 👤 Wesley C Stoesser
- 👤 Edmund H Sommerfield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:40
CPC Classifications
C; C07; C07C; C07C37/00; C07C37/68; C07C37/70; C07C37/84; C07C37/11; C07C37/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
69 words
IN A PROCESS WHEREIN PHENOL IS CONDENSED WITH ACETONE AT TEMPERATURES BETWEEN 15* AND 100* C. IN THE PRESENCE OF A VOLATILE ACIDIC CONDENSING AGENT TO FORM A SLURRY OF CRYSTALLINE MATERIAL COMPRISING 4,4''-ISOPROPYLIDENEDIPHENOL AND LIQUD AT TEMPERATURE BETWEEN 40* AND 80* C., THE STEPS WHICH CONSIST IN SEPARATION THE CRYSTALLINE MATERIAL FROM THE REACTION MIXTURE, WASHING THE CRYSTALS WITH LIQUID PHENOL AND SEPARATING 4,4''-ISOPROPYLIDENEDIPHENOL FROM THE CRYSTALLINE MATERIAL.
Claim 2
Dependent Claim
69 words
IN A PROCESS WHEREIN PHENOL IS CONDENSED WITH ACETONE AT TEMPERATURES BETWEEN 15* AND 100* C. IN THE PRESENCE OF A VOLATILE ACIDIC CONDENSING AGENT TO FORM A SLURRY OF CRYSTALLINE MATERIAL COMPRISING 4,4''-ISOPROPYLIDENEDIPHENOL AND LIQUD AT TEMPERATURE BETWEEN 40* AND 80* C., THE STEPS WHICH CONSIST IN SEPARATION THE CRYSTALLINE MATERIAL FROM THE REACTION MIXTURE, WASHING THE CRYSTALS WITH LIQUID PHENOL AND SEPARATING 4,4''-ISOPROPYLIDENEDIPHENOL FROM THE CRYSTALLINE MATERIAL.
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) | 1955-12-30 | 1956-06-30 | 1956-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-12-30 | 1960-06-30 | 1960-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-12-30 | 1964-06-30 | 1964-12-30 | $7700.00 | Window Closed / Lapsed |