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US2946822A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of m-phenylenediamine
Assignee: GAF Chemicals Corp
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Filing: 1956-10-05
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Granted: 1960-07-26
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Expires: 1976-10-05
Abstract
No abstract record available.
Inventors
- 👤 Leslie M Schenck
- 👤 Dennis L Deutsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:03
CPC Classifications
C; C07; C07C; C07C209/00; C07C209/68; C07C209/82; C07C209/84; C07C209/86; C07C211/00; C07C211/43; C07C211/44; C07C211/49; C07C211/50; C07C211/51; C07C251/00; C07C251/02; C07C251/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
105 words
THE PROCESS OF RECOVERING META-PHENYLENEDIAMINES FROM MIXTURE OF THE SAME WITH THE ORTHO- AND PARAISOMERS, WHICH COMPRISES ADDING TO AN AQUEOUS SOLUTION OF A MIXTURE OF SAID ISOMERIC DIAMINES, AT A TEMPERATURE BELOW ABOUT 100*C. A WATER SOLUBLE COMPOUND HAVING A CHROMIUM CONTAINING ANION AND SELECTED FROM THE GROUP CONSISTING OF CHROMIC ACID AND THE CHROMATE AND BICHROMATE SALTS THEREOF TO THEREBY FROM AN ADDITION PRODUCT WITH O- AND P-PHENYLENDIAMINES INSTANTANEOUSLY AND WHICH PRECIPITATES AS FORMED, AND SEPARATING SAID PRECIPITATED ADDITION PRODUCT FROM THE M-PHENYLENEDIAMINES BEFORE ANY APPRECIABLE AMOUNT OF ADDITION PRODUCT OF SAID COMPOUND HAVING A CHROMIUM CONTAINING ANION WITH SAID M-PHENYLENEDIAMINE IS FORMED.
Claim 2
Dependent Claim
105 words
THE PROCESS OF RECOVERING META-PHENYLENEDIAMINES FROM MIXTURE OF THE SAME WITH THE ORTHO- AND PARAISOMERS, WHICH COMPRISES ADDING TO AN AQUEOUS SOLUTION OF A MIXTURE OF SAID ISOMERIC DIAMINES, AT A TEMPERATURE BELOW ABOUT 100*C. A WATER SOLUBLE COMPOUND HAVING A CHROMIUM CONTAINING ANION AND SELECTED FROM THE GROUP CONSISTING OF CHROMIC ACID AND THE CHROMATE AND BICHROMATE SALTS THEREOF TO THEREBY FROM AN ADDITION PRODUCT WITH O- AND P-PHENYLENDIAMINES INSTANTANEOUSLY AND WHICH PRECIPITATES AS FORMED, AND SEPARATING SAID PRECIPITATED ADDITION PRODUCT FROM THE M-PHENYLENEDIAMINES BEFORE ANY APPRECIABLE AMOUNT OF ADDITION PRODUCT OF SAID COMPOUND HAVING A CHROMIUM CONTAINING ANION WITH SAID M-PHENYLENEDIAMINE IS 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) | 1963-07-26 | 1964-01-25 | 1964-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-07-26 | 1968-01-25 | 1968-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-07-26 | 1972-01-25 | 1972-07-26 | $7700.00 | Window Closed / Lapsed |