US5292858A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of production of copolymers of polyamino acids
Assignee: Calwood Chemical Industries Inc
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Filing: 1993-03-16
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Granted: 1994-03-08
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Expires: 2013-03-16
Abstract
Abstract Copolymers of polyamino acids formed by reaction of an alcohol with maleic anhydride to form the half ester followed by addition of ammonia, ammonia and an amine, or ammonia and a polyamine. The mixture is then heated to 120°-350° C. to form polysuccinimide or a derivative thereof. The resulting polysuccinimide may be hydrolyzed to form a derivative of polyaspartic acid or its salt.
Inventors
- 👤 Louis L. Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:55
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1092; C08G69/00; C08G69/02; C08G69/26; C08G69/28
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
142 words
A method of synthesis of a polyamide that has a repeating unit of the general formula of ##STR5## wherein R' is a hydrogen or an alkyl group having 1 to 36 carbons and R" is a hydrogen or an alkyl group having 1 to 36 carbons, together with at least one of the groups ##STR6## wherein Z represents a hydrogen atom, an alkali metal or an alkaline earth metal, as a repeating unit, the method comprising reacting maleic anhydride with an alcohol containing 1 to 36 carbons, to form the half ester followed by the addition of an equivalent of ammonia, or ammonia and an amine, containing one to 36 carbons, and heating to 120°-350° C., until one equivalent of alcohol is distilled away and hydrolyzing the copolymer of polysuccinimide formed with an alkaline earth or alkali metal hydroxide or ammonium hydroxide.
Claim 2
Independent Claim
142 words
A method of synthesis of a polyamide that has a repeating unit of the general formula of ##STR5## wherein R' is a hydrogen or an alkyl group having 1 to 36 carbons and R" is a hydrogen or an alkyl group having 1 to 36 carbons, together with at least one of the groups ##STR6## wherein Z represents a hydrogen atom, an alkali metal or an alkaline earth metal, as a repeating unit, the method comprising reacting maleic anhydride with an alcohol containing 1 to 36 carbons, to form the half ester followed by the addition of an equivalent of ammonia, or ammonia and an amine, containing one to 36 carbons, and heating to 120°-350° C., until one equivalent of alcohol is distilled away and hydrolyzing the copolymer of polysuccinimide formed with an alkaline earth or alkali metal hydroxide or ammonium hydroxide.
Claim 3
Dependent Claim
14 words
The method of claim 1 in which the alcohol contains 1 to 20 carbons.
Claim 4
Dependent Claim
14 words
The method of claim 1 in which the alcohol contains 1 to 10 carbons.
Claim 5
Dependent Claim
16 words
The method of claim 1 in which the alcohol is methanol, ethanol, n-propanol, isopropanol, or n-butanol.
Claim 6
Dependent Claim
12 words
The method of claim 1 in which the amine contains 8-20 carbons.
Claim 7
Dependent Claim
12 words
The method of claim 1 in which the temperature is 140°-285° C.
Claim 8
Dependent Claim
12 words
The method of claim 1 in which the temperature is 150°-245° C.
Claim 9
Dependent Claim
15 words
The method of claim 1 in which the hydroxide is sodium, potassium or ammonium hydroxide.
References Cited (Backward Citations)
US3351520A
Cited
US3846380A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-03-07 | 1997-09-06 | 1998-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-07 | 2001-09-06 | 2002-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-07 | 2005-09-06 | 2006-03-08 | $7700.00 | Window Closed / Lapsed |