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Patent US3940370A successfully refreshed from Google Patents.
US3940370A
Expired / Lapsed
US
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Method of making polyureas
Assignee: United States Department of the Army
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Filing: 1975-03-31
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Granted: 1976-02-24
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Expires: 1995-03-31
Abstract
Abstract A method of making a polyurea by reacting an aliphatic diamine with trimelisocyanatosilane under pressure in a closed vessel at a temperature sufficiently high and for a time sufficiently long to produce a substantial quantity of the polyurea.
Inventors
- 👤 Anthony L. DiSalvo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:10
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/71; C08G18/718; C08G18/28; C08G18/30; C08G18/32; C08G18/3225; C08G18/3228
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
46 words
Method of making a polyurea which comprises reacting an aliphatic diamine with trimethylisocyanatosilane in a closed, pressurized vessel at a temperature sufficiently high and for a time sufficiently long to produce a substantial quantity of said polyurea and separating said polyurea from by-products of the reaction.
Claim 2
Dependent Claim
46 words
Method of making a polyurea which comprises reacting an aliphatic diamine with trimethylisocyanatosilane in a closed, pressurized vessel at a temperature sufficiently high and for a time sufficiently long to produce a substantial quantity of said polyurea and separating said polyurea from by-products of the reaction.
Claim 3
Dependent Claim
21 words
Method according to claim 1, wherein said aliphatic diamine is selected from the group consisting of 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, and 1,10-decanediamine.
Claim 4
Dependent Claim
16 words
Method according to claim 1, wherein said aliphatic diamine is 1,6-hexanediamine and said polyurea is polyhexamethyleneurea.
Claim 5
Dependent Claim
14 words
Method according to claim 3, wherein said temperature of said reaction is about 175°C.
Claim 6
Dependent Claim
14 words
Method according to claim 4, wherein said time of reaction is about 17 hours.
References Cited (Backward Citations)
US3726907A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-23 | 1979-08-25 | 1980-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-23 | 1983-08-25 | 1984-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-23 | 1987-08-25 | 1988-02-24 | $7700.00 | Window Closed / Lapsed |