Patent US4443622A successfully refreshed from Google Patents.
US4443622A
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Method for making carbamates
Assignee: Bankers Trust Co
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Filing: 1982-09-24
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Granted: 1984-04-17
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Expires: 2002-09-24
Abstract
Abstract A process for the manufacture of alkyl carbamates from urea and aliphatic alcohols. The process is carried out under a vacuum, preferably at least 20 inches, and preferably in the presence of magnesium oxide catalyst.
Inventors
- 👤 Richard Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:07
CPC Classifications
C; C07; C07C; C07C271/00; C07C271/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
62 words
In a method for the manufacture of carbamates in which an alcohol is reacted with urea and ammonia is liberated, the improvement wherein the reaction is carried out at a temperature of at least 130° C., under a vacuum of at least 20 inches of mercury, said alcohol having a volatility no greater than that of diethylene glycol under the reaction conditions.
Claim 2
Dependent Claim
62 words
In a method for the manufacture of carbamates in which an alcohol is reacted with urea and ammonia is liberated, the improvement wherein the reaction is carried out at a temperature of at least 130° C., under a vacuum of at least 20 inches of mercury, said alcohol having a volatility no greater than that of diethylene glycol under the reaction conditions.
Claim 3
Dependent Claim
15 words
A method as set forth in claim 1 in which the vacuum is 28 inches.
Claim 4
Dependent Claim
32 words
A method as set forth in claim 1 in which the reaction is carried out in the presence of a catalyst selected from the group consisting of calcium, zinc and magnesium compounds.
Claim 5
Dependent Claim
26 words
A method as set forth in claim 3 in which the catalyst is selected from the group consisting of calcium oxide, zinc oxide and magnesium oxide.
Claim 6
Dependent Claim
15 words
A method as set forth in claim 1 in which the alcohol is diethylene glycol.
Claim 7
Dependent Claim
15 words
A method as set forth in claim 3 in which the alcohol is diethylene glycol.
Claim 8
Dependent Claim
36 words
In a method for the manufacture of carbamates in which an alcohol is reacted with urea under a vacuum, the improvement wherein the reaction is carried out in the presence of magnesium oxide as a catalyst.
Claim 9
Dependent Claim
36 words
In a method for the manufacture of carbamates in which an alcohol is reacted with urea under a vacuum, the improvement wherein the reaction is carried out in the presence of magnesium oxide as a catalyst.
Claim 10
Dependent Claim
19 words
A method as set forth in claim 7 in which a vacuum of at least 20 inches is applied.
Claim 11
Dependent Claim
17 words
A method as set forth in claim 8 in which a vacuum of 28 inches is applied.
Claim 12
Dependent Claim
15 words
A method as set forth in claim 8 in which the alcohol is diethylene glycol.
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) | 1987-04-17 | 1987-10-17 | 1988-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-17 | 1991-10-17 | 1992-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-17 | 1995-10-17 | 1996-04-17 | $7700.00 | Window Closed / Lapsed |