EP0058480A1
Expired / Lapsed
EP
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Extraction of poly(beta-hydroxybutyric acid)
Assignee: Imperial Chemical Industries Ltd
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Filing: 1982-01-26
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Granted: —
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Expires: 2002-01-26
Abstract
Abstract β-hydroxybutyric acid polymers are extracted from microorganism cells by contact with a solvent, such as 1,2-dichloroethane, which is a poor solvent for the polymer once it has been precipitated. The solution obtained by extraction is caused to gel and then solvent is expelled by subjecting the gel to a deformation process. Expelled solvent is recovered for extraction of polymer from a further quantity of cells.
Inventors
- 👤 Peter John Barham
- 👤 Alan Selwood
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 14:05
CPC Classifications
C; C12; C12P; C12P7/00; C12P7/62; C12P7/625
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
138 words
A process for the separation of a polymer containing at least 50 mole % of β-hydroxybutyric acid residues in the polymer chain from micro-organism cells comprising (a) extracting the polymer from the cells by contacting the polymer-containing cells with a solvent in which the polymer is soluble at the extraction temperature but in which extracted polymer, which has been freshly precipitated and not heated to above 40°C, is not soluble at temperatures below 25°C, (b) separating the solution of the polymer in said solvent from the micro-organism cell residue, (c) causing said solution to gel, (d) subjecting said gel to a non-random deformation process whereby the bulk of the solvent is expelled from said gel, and (e) using at least the bulk of said expelled solvent for extraction of polymer from a further quantity of the polymer-containing cells.
Claim 2
Dependent Claim
138 words
A process for the separation of a polymer containing at least 50 mole % of β-hydroxybutyric acid residues in the polymer chain from micro-organism cells comprising (a) extracting the polymer from the cells by contacting the polymer-containing cells with a solvent in which the polymer is soluble at the extraction temperature but in which extracted polymer, which has been freshly precipitated and not heated to above 40°C, is not soluble at temperatures below 25°C, (b) separating the solution of the polymer in said solvent from the micro-organism cell residue, (c) causing said solution to gel, (d) subjecting said gel to a non-random deformation process whereby the bulk of the solvent is expelled from said gel, and (e) using at least the bulk of said expelled solvent for extraction of polymer from a further quantity of the polymer-containing cells.
Claim 3
Dependent Claim
31 words
A process according to claim 1 wherein the amount of solvent used to extract the polymer is such that the resultant solution contains 0.5 to 10% by weight of the polymer.
Claim 4
Dependent Claim
31 words
A process according to claim 2 wherein the amount of solvent used to extract the polymer is such that the resultant solution contains at least 1.5% by weight of the polymer.
Claim 5
Dependent Claim
57 words
A process according to any one of claims 1 to 3 wherein gelation is effected by allowing the solution to stand at a temperature between 10 0 C and 30°C, optionally with one or more of the following preliminary steps: (i) cooling to below 0°C (ii) shearing, and (iii) seeding with a preformed gel of the polymer.
Claim 6
Dependent Claim
25 words
A process according to any one of claims 1 to 4 wherein the gel is deformed while in contact with at least one porous member.
Claim 7
Dependent Claim
17 words
A process according to any one of claims 1 to 5 wherein the deformed gel is extruded.
Claim 8
Dependent Claim
25 words
A process according to claim 6 wherein at least some of the solvent in the deformed gel is volatilised and removed during the extrusion step.
Claim 9
Dependent Claim
30 words
A process according to claim 6 or claim 7 wherein a solution of an additive in the solvent is added to the deformed gel before, or during, the extrusion step.
Claim 10
Dependent Claim
65 words
A process according to any one of claims 1 to 8 wherein the solvent used for the extraction of the polymer from a further quantity of the polymer-containing cells comprises the bulk of the solvent expelled during the deformation step together with (i) solvent expelled by syneresis during gel formation, and/or (ii) solvent recovered during further processing of the deformed gel, and/or (iii) fresh solvent.
Claim 11
Dependent Claim
62 words
A process according to any one of claims 1 to 9 wherein at least part of the solvent (i) expelled during the deformation step and/or (ii) expelled by syneresis during gel formation and/or (iii) recovered during further processing of the deformed gel is purified prior to its use for the extraction of the polymer from a further quantity of the polymer-containing cells.
References Cited (Backward Citations)
US4140741A
Cited
EP0024810A2
Cited
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