Patent US2807641A successfully refreshed from Google Patents.
US2807641A
Expired / Lapsed
US
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Sulphonation of benzene
Assignee: Vulcan Chemical Co Ltd
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Filing: 1953-08-20
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Granted: 1957-09-24
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Expires: 1973-08-20
Abstract
No abstract record available.
Inventors
- 👤 Milner David William
- 👤 Holdsworth Ernest Clifford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:59
CPC Classifications
C; C07; C07C; C07C309/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
48 words
A PROCESS OF PRODUCING BENZENE SULPHONIC ACID WHICH COMPRISES SELECTIVELY DISSOLVING GASEOUS SULPHUR TRIOXIDE FROM ADMIXTURE WITH DILUENT GASES IN LIQUID BENZENE SULPHONIC ACID, AND SULPHONATING BENZENE WITH THE DISSOLVED SULPHUIR TRIOXIDE AT A TEMPERATURE BELOW THAT AT WHICH SUBSTANTIAL SULPHONATION OF THE BENZENE SULPHONIC ACID TAKES PLACE.
Claim 2
Dependent Claim
48 words
A PROCESS OF PRODUCING BENZENE SULPHONIC ACID WHICH COMPRISES SELECTIVELY DISSOLVING GASEOUS SULPHUR TRIOXIDE FROM ADMIXTURE WITH DILUENT GASES IN LIQUID BENZENE SULPHONIC ACID, AND SULPHONATING BENZENE WITH THE DISSOLVED SULPHUIR TRIOXIDE AT A TEMPERATURE BELOW THAT AT WHICH SUBSTANTIAL SULPHONATION OF THE BENZENE SULPHONIC ACID TAKES PLACE.
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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) | 1960-09-23 | 1961-03-25 | 1961-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-09-23 | 1965-03-25 | 1965-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-09-23 | 1969-03-25 | 1969-09-24 | $7700.00 | Window Closed / Lapsed |