US3862973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of polyisocyanates containing biuret groups
Assignee: Bayer AG
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Filing: 1972-11-06
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Granted: 1975-01-28
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Expires: 1992-11-06
Abstract
Abstract Biuret-containing polyisocyanates are prepared by reacting organic polyisocyanates with secondary amines at temperatures of from about 80* to about 200*C. The polyisocyanates which contain biuret groups are useful as isocyanate precursors in the preparation of polyurethane plastics by the isocyanatepolyaddition process.
Inventors
- 👤 Werner Dietrich
- 👤 Kuno Wagner
- 👤 Manfred Roegler
- 👤 Helmut Kleimann
- 👤 Karl Hartwig Richert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:08
CPC Classifications
C; C07; C07C; C07C273/00; C07C273/18; C07C273/1854; C07C273/1863; C07C273/1809; C07C273/1818; C07C273/1827; C07C273/1872; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/77; C08G18/78; C08G18/7806; C08G18/7818; C08G18/7831; C08G18/80; C08G18/8003; C08G18/8006; C08G18/8038
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
12 words
The process of claim 1 wherein the organic polyisocyanate is a diisocyanate.
Claim 2
Dependent Claim
29 words
The process of claim 2 wherein the diisocyanate is selected from the group consisting of 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate and isomeric mixtures thereof, hexamethylene diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane and 4,4''-diphenylmethane diisocyanate.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein the secondary amine is a secondary monoamine.
Claim 4
Dependent Claim
22 words
The process of claim 4 wherein the secondary monoamine is selected from the group consisting of N-methylaniline, diphenylamine, dibutylamine, diethylamine and piperidine.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein the secondary amine is a disecondary diamine.
Claim 6
Dependent Claim
12 words
The process of claim 6 wherein the disecondary diamine is N, N''-diethyl-4,4''-diamino-diphenylmethane.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein the secondary amine is a mixture of secondary monoamines and disecondary diamines.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |