US3886218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of dihydroxydiphenylethers
Assignee: Union Rheinische Braunkohlen Kraftstoff AG
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Filing: 1973-07-19
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Granted: 1975-05-27
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Expires: 1993-07-19
Abstract
Abstract Production of dihydroxydiphenylethers by condensing hydroquinone or alkylhydroquinone in an inert organic solvent in the presence of an aluminum silicate catalyst and recovering the ethers by codistillation with special solvents, e.g. divinyl benzene.
Inventors
- 👤 Efim Biller
- 👤 Fritz-Peter Schmook
- 👤 Bernd Haas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:33
CPC Classifications
C; C07; C07C; C07C41/00; C07C41/01; C07C41/09
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
151 words
A PROCESS FOR THE PRODUCTION OF DIHYDROXYDIPHENYLETHER, WHICH COMPRISES REACTING A HYDROQUINONE OR AN ALKYLHYDIROQUINONE HAVING ONE OR TWO ALKYL GROUPS WITH UP TO 3 CARBON ATOMS AT TEMPERATURE OF FROM 50*C IN THE PRESENCE OF A NATURAL OR SYNTHETIC ALUMINUM SILICATE AS CATALYST IN AN INERT SOLVENT OR A MIXTURES OF SOLVENTS SELECTED FROM THE GROUP CONSISTING OF DODECANE, LOWER ALKYL BENZENES, CHLORO BENZENES, DIPHENYLETHERS, HYDROCARBONS HAVING 2 OR 3 PHENYL GROUPS COMBINED WITH AT LEAST 2 METHYL OR METHYLENE GROUPS AND MINERAL OIL FRACTIONS OF A CORRESPONDING BOILING RANGE, SEPARATING THE CATALYST FROM THE REACTION PRODUCT, REMOVING THE UNREACTED HYDROQUINONE BY CO-DISTILLATION WITH THE SAID SOLVENT AND REOCVERING THE 4,4''-DIHYDROXYDIPHENYLETHER BY VACUUM DISTILLATION OF THE REMAINING BOTTOM PRODUCT IN THE PRESENCE OF A SOLVENT SLEECTED FROM THE GROUP CONSISTING OF DIVINYLBENZENE, TRIPHENYLDIETHER AND MINERAL OIL FRACTIONS OF A CORRESPONDING BOILING RANGE, AND SEPARATING THE CRYSTALLISED ETHER FROM THE DISTILLATE.
Claim 2
Dependent Claim
151 words
A PROCESS FOR THE PRODUCTION OF DIHYDROXYDIPHENYLETHER, WHICH COMPRISES REACTING A HYDROQUINONE OR AN ALKYLHYDIROQUINONE HAVING ONE OR TWO ALKYL GROUPS WITH UP TO 3 CARBON ATOMS AT TEMPERATURE OF FROM 50*C IN THE PRESENCE OF A NATURAL OR SYNTHETIC ALUMINUM SILICATE AS CATALYST IN AN INERT SOLVENT OR A MIXTURES OF SOLVENTS SELECTED FROM THE GROUP CONSISTING OF DODECANE, LOWER ALKYL BENZENES, CHLORO BENZENES, DIPHENYLETHERS, HYDROCARBONS HAVING 2 OR 3 PHENYL GROUPS COMBINED WITH AT LEAST 2 METHYL OR METHYLENE GROUPS AND MINERAL OIL FRACTIONS OF A CORRESPONDING BOILING RANGE, SEPARATING THE CATALYST FROM THE REACTION PRODUCT, REMOVING THE UNREACTED HYDROQUINONE BY CO-DISTILLATION WITH THE SAID SOLVENT AND REOCVERING THE 4,4''-DIHYDROXYDIPHENYLETHER BY VACUUM DISTILLATION OF THE REMAINING BOTTOM PRODUCT IN THE PRESENCE OF A SOLVENT SLEECTED FROM THE GROUP CONSISTING OF DIVINYLBENZENE, TRIPHENYLDIETHER AND MINERAL OIL FRACTIONS OF A CORRESPONDING BOILING RANGE, AND SEPARATING THE CRYSTALLISED ETHER FROM THE DISTILLATE.
Claim 3
Dependent Claim
17 words
A process as claimed in claim 1 wherein acidactivated montmorillonite or bentonite is used as the catalyst.
Claim 4
Dependent Claim
20 words
A process as claimed in claim 1 wherein the water of reaction is removed by azeotropic distillation with the solvent.
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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |