Patent US4357237A successfully refreshed from Google Patents.
Patent US3207795A successfully refreshed from Google Patents.
US3207795A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production and purification of diphenylolalkanes
Assignee: Hooker Chemical Corp
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Filing: 1962-03-02
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Granted: 1965-09-21
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Expires: 1982-03-02
Abstract
No abstract record available.
Inventors
- 👤 Walter H Prahl
- 👤 Lederman Sol Joseph
- 👤 Ellis I Lichtblau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:25
CPC Classifications
C; C07; C07C; C07C37/00; C07C37/68; C07C37/70; C07C37/685; C07C37/74; C07C2601/00; C07C2601/12; C07C2601/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
99 words
A PROCESS FOR THE RECOVERY OF 2,2-(4,4''-DIHYDROXYDIPHENYL) PROPANE HAVING A FREEZING POINT GREATER THAN 156.5 DEGREES CENTIGRADE FROM ITS CRUDE REACTION PRODUCT PRODUCED BY THE CONDENSATION OFPHENOL WITH ACETONE IN THE PRESENCE OF AN ACIDIC SUBSTNACE INCLUDING THE STEPS OF (1) DISTILLING THE MORE VOLATILE MATERIALS FROM THE 2,2(4,4-DIHYDROXYDIPHENYL) PROPANE (2) VACUUM DISTILLING THE 2,2-(4,4''-DIHYDROXYDIPHENYL) PROPANE FROM MATERIALS LESS VOLTAILE IN IT, AND (3) TREATING THE DISTILLED 2,2-(4,4''DIHYDROXYDIPHENYL) PROPANE WITH A CHLORINATED ALIPHATIC HYDROCARBON SOLVENT SELECTED FROM THE GROUP CONSISTING OF METHYLENE CHLORIDE, ETHYLENE DICHLORIDE, AND TRICHLOROETHYLENE, WHEREBY 2,2-(4-4''-DIHYROXYDIPHENYL) PROPANE AND A SOLVENT SOLUTION OF EXTRACTED IMPURITIES ARE PRODUCED.
Claim 2
Dependent Claim
99 words
A PROCESS FOR THE RECOVERY OF 2,2-(4,4''-DIHYDROXYDIPHENYL) PROPANE HAVING A FREEZING POINT GREATER THAN 156.5 DEGREES CENTIGRADE FROM ITS CRUDE REACTION PRODUCT PRODUCED BY THE CONDENSATION OFPHENOL WITH ACETONE IN THE PRESENCE OF AN ACIDIC SUBSTNACE INCLUDING THE STEPS OF (1) DISTILLING THE MORE VOLATILE MATERIALS FROM THE 2,2(4,4-DIHYDROXYDIPHENYL) PROPANE (2) VACUUM DISTILLING THE 2,2-(4,4''-DIHYDROXYDIPHENYL) PROPANE FROM MATERIALS LESS VOLTAILE IN IT, AND (3) TREATING THE DISTILLED 2,2-(4,4''DIHYDROXYDIPHENYL) PROPANE WITH A CHLORINATED ALIPHATIC HYDROCARBON SOLVENT SELECTED FROM THE GROUP CONSISTING OF METHYLENE CHLORIDE, ETHYLENE DICHLORIDE, AND TRICHLOROETHYLENE, WHEREBY 2,2-(4-4''-DIHYROXYDIPHENYL) PROPANE AND A SOLVENT SOLUTION OF EXTRACTED IMPURITIES ARE PRODUCED.
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) | 1968-09-20 | 1969-03-22 | 1969-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-20 | 1973-03-22 | 1973-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-20 | 1977-03-22 | 1977-09-21 | $7700.00 | Window Closed / Lapsed |