US4360488A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal of solvent from gels of poly(hydroxybutyrate) and shaped articles formed therefrom
Assignee: Syngenta Ltd
•
Filing: 1980-08-04
•
Granted: 1982-11-23
•
Expires: 2000-08-04
Abstract
Abstract A process of forming shaped articles comprising forming a free draining gel from a solution of poly(hydroxybutyrate) in a poor solvent under conditions which cause crystallization of the polymer and subjecting the gel to a non-random deformation process so that the associated solvent is expressed. Some residual solvent may be present and can assist in subsequent fabrication processes but the solvent may also be completely removed for such processes. The resulting products have good physical properties, after uniaxial or biaxial drawing.
Inventors
- 👤 Peter J. Barham
- 👤 Alan Selwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:01
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/88; C08F; C08F6/00; C08F6/06; C08F6/12; C08G63/02; C08G63/06; C12; C12P; C12P7/00; C12P7/62; C12P7/625
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
24 words
A process comprising forming a gel from a solution of poly(hydroxybutyrate) in a poor solvent and subjecting the gel to a non-random deformation process.
Claim 2
Dependent Claim
24 words
A process comprising forming a gel from a solution of poly(hydroxybutyrate) in a poor solvent and subjecting the gel to a non-random deformation process.
Claim 3
Dependent Claim
12 words
A process according to claim 1 in which the solvent is 1,2-dichloroethane.
Claim 4
Dependent Claim
23 words
A process according to either claim 1 or claim 2 in which the non-random deformation process comprises pressing the gel between opposed surfaces.
Claim 5
Dependent Claim
22 words
A process according to claim 1 in which the product obtained by subjecting the gel to the non-random deformation is then oriented.
Claim 6
Dependent Claim
31 words
A process according to claim 1 in which the product obtained by subjecting the gel to the non-random deformation is fabricated into a shaped article at a temperature below 160° C.
Claim 7
Dependent Claim
32 words
A process according to claim 1 in which the non-random deformation process is such as to remove only part of the solvent and the product thereof is fabricated into a shaped article.
Claim 8
Dependent Claim
36 words
A process according to claim 1 in which the product obtained by subjecting the gel to the non-random deformation process is subjected to a fabrication step and a plasticizer is incorporated prior to said fabrication step.
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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) | 1985-11-22 | 1986-05-24 | 1986-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-22 | 1990-05-24 | 1990-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-22 | 1994-05-24 | 1994-11-23 | $7700.00 | Window Closed / Lapsed |