Patent US4147714A successfully refreshed from Google Patents.
US4147714A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of polyisocyanates which contain biuret groups
Assignee: Bayer AG
•
Filing: 1978-05-12
•
Granted: 1979-04-03
•
Expires: 1998-05-12
Abstract
Abstract This invention relates to an improved process for the preparation of polyisocyanates which contain biuret groups by the direct reaction of polyamines in vapor form with polyisocyanates.
Inventors
- 👤 Hartmut Hetzel
- 👤 Klaus Konig
- 👤 Hans G. Schmelzer
- 👤 Kuno Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:24
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/77; C08G18/78; C08G18/7806; C08G18/7818; C08G18/7831; C07; C07C; C07C273/00; C07C273/18; C07C273/1809; C07C273/1818; C07C273/1827; C08G18/80; C08G18/8003; C08G18/8006; C08G18/8038
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
78 words
A process for the preparation of polyisocyanates having biuret groups by the reaction of aliphatic diamines containing from 2 to 12 carbon atoms with aliphatic diisocyanates containing from 4 to 12 carbon atoms which are free from biuret groups at a molar ratio of NH 2 /NCO between about 1:5 and 1:100, characterized in that the diamines are reacted in vapor form with the diisocyanates which are heated to a temperature from about 100° C. to 250° C.
Claim 2
Dependent Claim
78 words
A process for the preparation of polyisocyanates having biuret groups by the reaction of aliphatic diamines containing from 2 to 12 carbon atoms with aliphatic diisocyanates containing from 4 to 12 carbon atoms which are free from biuret groups at a molar ratio of NH 2 /NCO between about 1:5 and 1:100, characterized in that the diamines are reacted in vapor form with the diisocyanates which are heated to a temperature from about 100° C. to 250° C.
Claim 3
Dependent Claim
49 words
A process according to claim 1, characterized in that a gaseous mixture comprising a carrier gas which is inert towards the reactants and the polyamine in vapor form is introduced into the heated polyisocyanates at a volumetric ratio of carrier gas to polyamine of between about 2:1 and 100:1.
Claim 4
Dependent Claim
28 words
A process according to claim 1, characterized in that before the biuret-free polyisocyanate is used, it is preheated at about 120° to 195° C. and is then distilled.
Claim 5
Dependent Claim
27 words
The process of claim 3 wherein the biuret-free polyisocyanate is preheated for about 6 to 10 hours at about 160° to 180° C. and is then distilled.
Claim 6
Dependent Claim
20 words
The process of claim 1 wherein the polyisocyanates are heated to a temperature of from about 130° to 200° C.
Claim 7
Dependent Claim
76 words
In a process for the preparation of polyisocyanates having biuret groups by the reaction of aliphatic diamines containing from 2 to 12 carbon atoms with aliphatic diisocyanates containing 4 to 12 carbon atoms which are free from biuret groups at a molar ratio of NH 2 /NCO between about 1:5 and 1:100, the improvement comprising reacting the diamines in vapor form with the diisocyanates which are at a temperature at from about 100° to 250° C.
Claim 8
Dependent Claim
76 words
In a process for the preparation of polyisocyanates having biuret groups by the reaction of aliphatic diamines containing from 2 to 12 carbon atoms with aliphatic diisocyanates containing 4 to 12 carbon atoms which are free from biuret groups at a molar ratio of NH 2 /NCO between about 1:5 and 1:100, the improvement comprising reacting the diamines in vapor form with the diisocyanates which are at a temperature at from about 100° to 250° C.
Claim 9
Dependent Claim
47 words
A process for the preparation of polyisocyanates having biuret groups by the reaction of hexamethylene diamine with hexamethylene diisocyanate at a molar ratio of NH 2 /NCO between about 1:5 and 1:100, characterized in that the hexamethylene diamine is reacted in vapor form with the hexamethylene diisocyanate.
Claim 10
Dependent Claim
47 words
A process for the preparation of polyisocyanates having biuret groups by the reaction of hexamethylene diamine with hexamethylene diisocyanate at a molar ratio of NH 2 /NCO between about 1:5 and 1:100, characterized in that the hexamethylene diamine is reacted in vapor form with the hexamethylene diisocyanate.
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) | 1982-04-02 | 1982-10-02 | 1983-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-02 | 1986-10-02 | 1987-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-02 | 1990-10-02 | 1991-04-03 | $7700.00 | Window Closed / Lapsed |