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US4960866A
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Catalyst-free resorbable homopolymers and copolymers
Assignee: Boehringer Ingelheim GmbH
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Filing: 1989-01-24
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Granted: 1990-10-02
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Expires: 2009-01-24
Abstract
Abstract The invention relates to resorbable homopolymers and copolymers which are substantially free from polymerization catalysts and processes for preparing them.
Inventors
- 👤 Dieter Bendix
- 👤 Gunther Entenmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:46
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/88; C08G63/90; A; A61; A61K; A61K47/00; A61K47/30; A61K47/34; A61L; A61L17/00; A61L17/06; A61L17/10; A61L17/12; A61L27/00; A61L27/14; A61L27/18; A61L31/00; A61L31/04; A61L31/06
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
75 words
A process for producing catalyst-free resorbable homopolymers or copolymers comprising the steps of: (a) dissolving a catalyst-containing polymer in an organic solvent which is immiscible with water, (b) bringing the thus dissolved polymer into intimate contact with water or with an aqueous phase which contains an inorganic acid, a water-soluble organic acid or a water-soluble complexing agent, (c) separating the organic phase from the aqueous phase, and (d) isolating the polymer from the organic phase.
Claim 2
Dependent Claim
75 words
A process for producing catalyst-free resorbable homopolymers or copolymers comprising the steps of: (a) dissolving a catalyst-containing polymer in an organic solvent which is immiscible with water, (b) bringing the thus dissolved polymer into intimate contact with water or with an aqueous phase which contains an inorganic acid, a water-soluble organic acid or a water-soluble complexing agent, (c) separating the organic phase from the aqueous phase, and (d) isolating the polymer from the organic phase.
Claim 3
Dependent Claim
31 words
The process as claimed in claim 1, characterized in that the acid or the complexing agent is present in the aqueous phase in a concentration of from about 0.1 to 5%.
Claim 4
Dependent Claim
27 words
The process as claimed in claims 1 or 2, characterized in that the concentration of the dissolved polymer in the organic solvent does not exceed about 10%.
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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) | 1993-10-01 | 1994-04-02 | 1994-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-01 | 1998-04-02 | 1998-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-01 | 2002-04-02 | 2002-10-02 | $7700.00 | Window Closed / Lapsed |