US4283571A
Expired / Lapsed
US
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Process for the catalytic isomerization of o-cresol
Assignee: Union Rheinische Braunkohlen Kraftstoff AG
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Filing: 1979-01-30
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Granted: 1981-08-11
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Expires: 1999-01-30
Abstract
Abstract Isomerization of o-cresol to m-cresol by contact with a crystalline aluminosilicate zeolite of the ZSM-type, having a silica to alumina ratio greater than 5, at a temperature of about 350° to 450° C.
Inventors
- 👤 Karl-Heinz Keim
- 👤 Reinhard Kiauk
- 👤 Ewald Meisenburg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:20
CPC Classifications
C; C07; C07C; C07C37/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
85 words
In a process for isomerisation of o-cresol to m-cresol in the presence of an alumina and silica containing catalyst at elevated temperatures, the improvement which comprises reacting the o-cresol at temperatures of about 350° to 450° C. in the presence of an acidly acting crystalline aluminosilicate zeolite of the ZSM-type with a composition of oxides and water in the molar ratio of 1±0.4 M 2 O/n:Al 2 O 3 :5-100 SiO 2 :0-60 H 2 O, M representing a cation having a valence of n.
Claim 2
Dependent Claim
85 words
In a process for isomerisation of o-cresol to m-cresol in the presence of an alumina and silica containing catalyst at elevated temperatures, the improvement which comprises reacting the o-cresol at temperatures of about 350° to 450° C. in the presence of an acidly acting crystalline aluminosilicate zeolite of the ZSM-type with a composition of oxides and water in the molar ratio of 1±0.4 M 2 O/n:Al 2 O 3 :5-100 SiO 2 :0-60 H 2 O, M representing a cation having a valence of n.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein the zeolite has a composition of 0.9±0.2 M 2 O/n:Al 2 O 3 :5-100 SiO 2 :0-40 H 2 O.
Claim 4
Dependent Claim
20 words
The process of claim 1 wherein the o-cresol is reacted under a pressure of between about 45 to 80 bar.
Claim 5
Dependent Claim
20 words
The process of claim 2 wherein the o-cresol is reacted under a pressure of between about 50 to 60 bar.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-10 | 1985-02-09 | 1985-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-10 | 1989-02-09 | 1989-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-10 | 1993-02-09 | 1993-08-11 | $7700.00 | Window Closed / Lapsed |