Patent US2831012A successfully refreshed from Google Patents.
US2831012A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical process
Assignee: EIDP Inc
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Filing: 1957-03-29
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Granted: 1958-04-15
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Expires: 1977-03-29
Abstract
No abstract record available.
Inventors
- 👤 Robert A Bernard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:22
CPC Classifications
C; C07; C07C; C07C263/00; C07C263/18; C07C263/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
95 words
A PROCESS FOR REMOVING TOLUENE-2,4-DIISOCYANATE AND TOLUENE-2,6-DIISOCYANATE IN A MOLAR RATIO OF AT LEAST ABOUT 70:30, FROM AN ISOMERIC MIXTURE THEREOF, SAID MIXTURE CONTAINING THE ISOMERS IN A MOLAR RATIO FROM 91:9 TO 40:60, WHICH PROCESS COMPRISES TREATING A SOLUTION CONTAINING UP TO ABOUT 50% BY WEIGHT OF SAID MIXTURE IN AN INERT SOLVENT, AT A TEMPERATURE BETWEEN ABOUT 0 TO 70*C., WITH AT LEAST ABOUT ONE MOLAR EQUIVALENT OF DRY HYDROGEN CHLORIDE FOR EACH MOLE OF TOLUENE-2,4-DIISOCYANATE TO BE REMOVED FROM THE MIXTURE, FOLLOWED BY COOLING THE MIXTURE AND SEPARATING THE PRECIPITATE THUS FORMED.
Claim 2
Dependent Claim
95 words
A PROCESS FOR REMOVING TOLUENE-2,4-DIISOCYANATE AND TOLUENE-2,6-DIISOCYANATE IN A MOLAR RATIO OF AT LEAST ABOUT 70:30, FROM AN ISOMERIC MIXTURE THEREOF, SAID MIXTURE CONTAINING THE ISOMERS IN A MOLAR RATIO FROM 91:9 TO 40:60, WHICH PROCESS COMPRISES TREATING A SOLUTION CONTAINING UP TO ABOUT 50% BY WEIGHT OF SAID MIXTURE IN AN INERT SOLVENT, AT A TEMPERATURE BETWEEN ABOUT 0 TO 70*C., WITH AT LEAST ABOUT ONE MOLAR EQUIVALENT OF DRY HYDROGEN CHLORIDE FOR EACH MOLE OF TOLUENE-2,4-DIISOCYANATE TO BE REMOVED FROM THE MIXTURE, FOLLOWED BY COOLING THE MIXTURE AND SEPARATING THE PRECIPITATE THUS FORMED.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-04-14 | 1961-10-14 | 1962-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-04-14 | 1965-10-14 | 1966-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-04-14 | 1969-10-14 | 1970-04-15 | $7700.00 | Window Closed / Lapsed |