US2988545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of azodicarbonamide
Assignee: National Polychemicals Inc
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Filing: 1957-10-17
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Granted: 1961-06-13
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Expires: 1977-10-17
Abstract
No abstract record available.
Inventors
- 👤 Henry A Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:02
CPC Classifications
C; C07; C07C; C07C281/00; C07C281/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
127 words
THE PROCESS OF PRODUCING AZODICARBONAMIDE, WHICH COMPRISES SUSPENDING APPROXIMATELY ONE PART, BY WEIGHT, OF HYDRAZODICARBONAMIDE IN TWO TO FOUR PARTS, BY WEIGHT, OF WATER TO FORM AN AQUEOUS SLURRY, ADDING TO SAID SLURRY AN ALKALI METAL CHROMATE IN AN AMOUNT AT LEAST SUFFICIENT TO EFFECT COMPLETE OXIDATION OF THE HYDRAZODICARBONAMIDE, SLOWLY ADDING DILUTE SULFURIC ACID TO SAID SLURRY IN AN AMOUNT SUFFICIENT TO LIBERATE THE CRO3 FROM SAID CHROMATE AND TO EFFECT OXIDATION OF THE HYDRAZODICARBONAMIDE TO PARTIALLY CONVERT THE HYDRAZODICARBONAMIDE TO AZODICARBONAMIDE WHILE MAINTAINING THE REACTION MIXTURE AT A TEMPERATURE OF APPROXIMATELY 85* F., THEREAFTER HEATING THE REACTION MIXTURE TO A TEMPERATURE BETWEEN 110* AND 150* F. UNTIL APPROXIMATELY COMPLETE CONVERSION TO AZODICARBONAMIDE HAS BEEN ACHIEVED, AND FINALLY FILTERING, WASHING AND DRYING THE AZODICARBONAMIDE THUS PRODUCED.
Claim 2
Dependent Claim
127 words
THE PROCESS OF PRODUCING AZODICARBONAMIDE, WHICH COMPRISES SUSPENDING APPROXIMATELY ONE PART, BY WEIGHT, OF HYDRAZODICARBONAMIDE IN TWO TO FOUR PARTS, BY WEIGHT, OF WATER TO FORM AN AQUEOUS SLURRY, ADDING TO SAID SLURRY AN ALKALI METAL CHROMATE IN AN AMOUNT AT LEAST SUFFICIENT TO EFFECT COMPLETE OXIDATION OF THE HYDRAZODICARBONAMIDE, SLOWLY ADDING DILUTE SULFURIC ACID TO SAID SLURRY IN AN AMOUNT SUFFICIENT TO LIBERATE THE CRO3 FROM SAID CHROMATE AND TO EFFECT OXIDATION OF THE HYDRAZODICARBONAMIDE TO PARTIALLY CONVERT THE HYDRAZODICARBONAMIDE TO AZODICARBONAMIDE WHILE MAINTAINING THE REACTION MIXTURE AT A TEMPERATURE OF APPROXIMATELY 85* F., THEREAFTER HEATING THE REACTION MIXTURE TO A TEMPERATURE BETWEEN 110* AND 150* F. UNTIL APPROXIMATELY COMPLETE CONVERSION TO AZODICARBONAMIDE HAS BEEN ACHIEVED, AND FINALLY FILTERING, WASHING AND DRYING THE AZODICARBONAMIDE THUS PRODUCED.
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) | 1964-06-12 | 1964-12-12 | 1965-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-12 | 1968-12-12 | 1969-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-12 | 1972-12-12 | 1973-06-13 | $7700.00 | Window Closed / Lapsed |