Patent US4968611A successfully refreshed from Google Patents.
US4968611A
Expired / Lapsed
US
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Extracting agents for poly-D(-)-3-hydroxybutyric acid
Assignee: PCD Polymere GmbH
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Filing: 1989-06-22
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Granted: 1990-11-06
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Expires: 2009-06-22
Abstract
Abstract Use of diols or acetalized triols, di- or tricarboxylic acid esters, mixtures of dicarboxylic acid esters or butyrolactone as extracting agents for obtaining pure polyesters or copolyesters containing 3-hydroxybutyric acid units.
Inventors
- 👤 Heinz Traussnig
- 👤 Engelbert Kloimstein
- 👤 Hans Kroath
- 👤 Robert Estermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:59
CPC Classifications
C; C12; C12P; C12P7/00; C12P7/62; C12P7/625; C08; C08G; C08G63/00; C08G63/88; C08G63/90
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
79 words
In a process for the preparation of a polyester or copolyester containing 3-hydroxybutyric acid units by cultivation of a poly-D(-)-3-hydroxybutyric acid producing microorganism in a fermentation medium and subsequent extraction and recovery of the desired product, the improvement which comprises using as an extracting agent a solvent selected from the group consisting of diols and acetalized triols, di- or tricarboxylic acid esters, mixtures of dicarboxylic acid esters, and butyrolactone to obtain said polyester or copolyester in substantially pure form.
Claim 2
Dependent Claim
79 words
In a process for the preparation of a polyester or copolyester containing 3-hydroxybutyric acid units by cultivation of a poly-D(-)-3-hydroxybutyric acid producing microorganism in a fermentation medium and subsequent extraction and recovery of the desired product, the improvement which comprises using as an extracting agent a solvent selected from the group consisting of diols and acetalized triols, di- or tricarboxylic acid esters, mixtures of dicarboxylic acid esters, and butyrolactone to obtain said polyester or copolyester in substantially pure form.
Claim 3
Dependent Claim
13 words
A process according to claim 1, in which said extracting agent is propanediol.
Claim 4
Dependent Claim
14 words
A process according to claim 1, in which said extracting agent is glycerol formal.
Claim 5
Dependent Claim
17 words
A process according to claim 1, in which said extracting agent is dimethyl succinate or diethyl succinate.
Claim 6
Dependent Claim
22 words
A process according to claim 1, in which said extracting agent is a mixture of dimethyl succinate, dimethyl glutarate and dimethyl adipate.
Claim 7
Dependent Claim
13 words
A process according to claim 1, in which said extracting agent is butyrolactone.
Claim 8
Dependent Claim
54 words
A process according to claim 1, in which cell material of said microorganism is removed from said fermentation medium, heated to a temperature of from about 110° to 140° C. in said extracting agent, the resulting solution cooled and, after removing undissolved cell material, the desired product is precipitated and recovered from said solution.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |