US2691644A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sulfonation method
Assignee: Dow Chemical Co
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Filing: 1952-02-21
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Granted: 1954-10-12
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Expires: 1972-02-21
Abstract
No abstract record available.
Inventors
- 👤 Harold H Roth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:12
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/34; C08F8/36
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
73 words
A METHOD FOR SULPHONATING A BENZENESOLUBLE, THERMOPLASTIC ALKENYL AROMATIC RESIN WHICH COMPRISES REACTING SULPHUR TRIOXIDE WITH THE RESIN AT TEMPERATURES BETWEEN -20* AND 40* C. WHILE HAVING THE REACTANTS DISSOLVED IN A LIQUID MIXTURE OF FROM 20 TO 80 WEIGHT PER CENT OF SULPHUR DIOXIDE AND FROM 80 TO 20 PER CENT OF AT LEAST ONE POLYCHLORINATED ALIPHATIC HYDROCARBON OF THE CLASS CONSISTING OF METHYLENE CHLORIDE, CARBON TETRACHLORIDE, TETRACHLOROETHYLENE, METHYLCHLOROFORM AND ETHYLENE CHLORIDE.
Claim 2
Independent Claim
73 words
A METHOD FOR SULPHONATING A BENZENESOLUBLE, THERMOPLASTIC ALKENYL AROMATIC RESIN WHICH COMPRISES REACTING SULPHUR TRIOXIDE WITH THE RESIN AT TEMPERATURES BETWEEN -20* AND 40* C. WHILE HAVING THE REACTANTS DISSOLVED IN A LIQUID MIXTURE OF FROM 20 TO 80 WEIGHT PER CENT OF SULPHUR DIOXIDE AND FROM 80 TO 20 PER CENT OF AT LEAST ONE POLYCHLORINATED ALIPHATIC HYDROCARBON OF THE CLASS CONSISTING OF METHYLENE CHLORIDE, CARBON TETRACHLORIDE, TETRACHLOROETHYLENE, METHYLCHLOROFORM AND ETHYLENE CHLORIDE.
References Cited (Backward Citations)
US2500149A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-10-11 | 1958-04-12 | 1958-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-10-11 | 1962-04-12 | 1962-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-10-11 | 1966-04-12 | 1966-10-12 | $7700.00 | Window Closed / Lapsed |