US3350438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing biuret polyisocyanates
Assignee: Bayer AG
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Filing: 1964-02-05
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Granted: 1967-10-31
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Expires: 1984-02-05
Abstract
No abstract record available.
Inventors
- 👤 Hennig Hans Joachim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:28
CPC Classifications
C; C07; C07C; C07C273/00; C07C273/18; C07C273/1854; C07C273/1863; C07C273/1872; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/77; C08G18/78; C08G18/7806; C08G18/7818; C08G18/7831
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
46 words
A PROCESS FOR THE PREPARATION OF A BIURET POLYISOCYANATE WHICH COMPRISES REACTING AN ORGANIC POLYISOCYANATE WITH ANHYDROUS FORMIC ACID AT A TEMPERATURE OF FROM ABOUT 80 TO ABOUT 200*C. IN THE MOLECULAR RATIO OF AT LEAST 3 MOLS OF ORGANIC POLYISOCYANATE PER MOL OF FORMIC ACID.
Claim 2
Dependent Claim
46 words
A PROCESS FOR THE PREPARATION OF A BIURET POLYISOCYANATE WHICH COMPRISES REACTING AN ORGANIC POLYISOCYANATE WITH ANHYDROUS FORMIC ACID AT A TEMPERATURE OF FROM ABOUT 80 TO ABOUT 200*C. IN THE MOLECULAR RATIO OF AT LEAST 3 MOLS OF ORGANIC POLYISOCYANATE PER MOL OF FORMIC ACID.
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) | 1970-10-30 | 1971-05-01 | 1971-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-10-30 | 1975-05-01 | 1975-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-10-30 | 1979-05-01 | 1979-10-31 | $7700.00 | Window Closed / Lapsed |