US2663700A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of sulfonated alkenyl aromatic resins
Assignee: Dow Chemical Co
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Filing: 1951-12-01
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Granted: 1953-12-22
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Expires: 1971-12-01
Abstract
No abstract record available.
Inventors
- 👤 Harold H Roth
- 👤 Hugh B Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:23
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/34; C08F8/36
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
49 words
A METHOD, WHICH COMPRISES EXTRACTING, FROM A GRANULAR ALKENYL AROMATIC RESIN SULPHONIC ACID, ACIDIC INORGANIC IMPURITIES INCIDENT TO FORMATION OF THE SAME, BY WASHING THE GRANULAR RESIN SULPHONIC ACID WITH AT LEAST ONE SUBSTANTIALLY ANHYDROUS LIQUID OF THE GROUP CONSISTING OF ETHERS, KETONES, LIQUID SULPHUR DIOXIDE AND METHYLENE CHLORIDE.
References Cited (Backward Citations)
US2533211A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-12-21 | 1957-06-22 | 1957-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-12-21 | 1961-06-22 | 1961-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-12-21 | 1965-06-22 | 1965-12-22 | $7700.00 | Window Closed / Lapsed |