Patent US3193046A successfully refreshed from Google Patents.
Patent US3257445A successfully refreshed from Google Patents.
US3257445A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of acrylonitrile
Assignee: Ruhrchemie AG
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Filing: 1961-06-22
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Granted: 1966-06-21
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Expires: 1981-06-22
Abstract
No abstract record available.
Inventors
- 👤 Roelen Otto
- 👤 Rottig Walter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:31
CPC Classifications
C; C07; C07C; C07C253/00; C07C253/32; C07C253/34
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
112 words
PROCESS FOR PURIFYING ACRYLONITRILE PRODUCED BY THE CATALYTIC OXIDATION OF PROPYLENE IN THE PRESENCE OF AMMONIA AND OXYGEN FOR THE REMOVAL THEREFROM OF HYDROCYANIC ACID AND POLYACRYLONITRILE WHICH COMPRISES SUBJECTING THE CRUDE ACRYLONITRILE TO A WASHING TREATMENT WITH ABOUT A 10-20% AQUEOUS SOLUTION OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL AND ALKALINE EARTH METAL HYDROXIDES, ADJUSTING THE PH OF THE ACRYLONITRILE OBTAINED FROM THE WASHING TREATMENT TO A VALUE OF FROM ABOUT 5-7 BY ADDING TO THE WASHED ACRYLONITRILE A MEMBER SELECTED FROM THE GROUP CONSISTING OF SULFURIC, PHOSPHORIC, ACETIC, AND OXALIC ACIDS, AND ISOLATING THE SUBSTANTIALLY PURE ACRYLONITRILE FROM THE RESULTING MIXTURE BY A FRACTIONAL DISTILLATION THEREOF.
Claim 2
Dependent Claim
112 words
PROCESS FOR PURIFYING ACRYLONITRILE PRODUCED BY THE CATALYTIC OXIDATION OF PROPYLENE IN THE PRESENCE OF AMMONIA AND OXYGEN FOR THE REMOVAL THEREFROM OF HYDROCYANIC ACID AND POLYACRYLONITRILE WHICH COMPRISES SUBJECTING THE CRUDE ACRYLONITRILE TO A WASHING TREATMENT WITH ABOUT A 10-20% AQUEOUS SOLUTION OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL AND ALKALINE EARTH METAL HYDROXIDES, ADJUSTING THE PH OF THE ACRYLONITRILE OBTAINED FROM THE WASHING TREATMENT TO A VALUE OF FROM ABOUT 5-7 BY ADDING TO THE WASHED ACRYLONITRILE A MEMBER SELECTED FROM THE GROUP CONSISTING OF SULFURIC, PHOSPHORIC, ACETIC, AND OXALIC ACIDS, AND ISOLATING THE SUBSTANTIALLY PURE ACRYLONITRILE FROM THE RESULTING MIXTURE BY A FRACTIONAL DISTILLATION THEREOF.
References Cited (Backward Citations)
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Cited
US2555798A
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US2653966A
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US2784218A
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US2793227A
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US2827423A
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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) | 1969-06-20 | 1969-12-20 | 1970-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-06-20 | 1973-12-20 | 1974-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-06-20 | 1977-12-20 | 1978-06-21 | $7700.00 | Window Closed / Lapsed |