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AssigneeEvonik Roehm GmbH
InventorsHans Baer, Felix Hofmann, Silke Schminke, Julian Blaesy, Isabel Wahl
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The invention refers to a Process for preparing a bio-resorbable polyester the form of a powder with a bulk density of 0.3 g/ml or more, a tapped density of 0.4 g/ml or more and a specific surface area of 2.0 m2/g or less comprising the steps a. dissolving a bio-resorbable polyester in a first solvent to form a polymer solution, b. contacting the polymer solution with a second solvent which is a non-solvent for the bioresorbable polyester and which is mainly water to result the precipitation of the bio-resorbable polyester in the form of a wet polymer mass, c. pre-drying the wet polymer mass at a temperature below the TgO of the bio-resorbable polyester, d. comminuting the pre-dried polymer mass to polymer particles with a size below 10 mm, e. drying the comminuted polymer particles below the TgO of the bio-resorbable polyester to a residual water content of 1% or less by weight/weight, f. post-treatment of the polymer particles from step e at a temperature in the range from the TgO to the TgE of the bio-resorbable polyester, g. comminuting the polymer particles from step f to a powder with a particle size of d50 of 1-300 μm and d90 of more than 30 and up to 3000 μm.
A process for preparing a bio-resorbable polyester in the form of a powder, wherein the bio-resorable polyester has
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Powdering or granulating: by precipitation from solutions
Macromolecular organic or inorganic compounds, e.g. inorganic polyphosphates: macromolecular compounds obtained otherwise than by reactions only…
Macromolecular materials: obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
Macromolecular materials: obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
About 6 years 10 months of term left · ends 29 Aug 2033 (estimated)
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US2010/0137550A1 describes a method and device for cleaning absorptive or resorbable polyester. The process for purifying a resorbable polyester is comprising the steps of dissolving the resorbable polyester in a first solvent to form a polymer solution, intimately contacting the polymer solution with a second solvent under the action of high shear forces in a turbulent shear field to form a polymer suspension, wherein the second solvent is a non-solvent for the resorbable polyester and is unlimitedly miscible with the first solvent, conveying the polymer suspension onto or into a rotating cylindrical screen body and drying the polymer mass.
The invention refers to a process for preparing a bio-resorbable polyester the form of a powder with a bulk density of 0.3 g/ml or more, 0.35 g/ml or more, 0.4 g/ml or more, 0.45 g/ml or more, 0.5 g/ml or more, preferably from 0.3 to 0.75, 0.35 to 0.65, 0.4 to 0.6, 0.4-0.45, 0.5-0.6.
The invention refers to a process for preparing a bio-resorbable polyester the form of a powder with a tapped density of 0.4 g/ml or more, 0.5 g/ml or more, preferably from 0.4 to 0.75, 0.45 to 0.65, 0.5 to 0.55, 0.55-0.7.
The invention refers to a process for preparing a bio-resorbable polyester in the form of a powder with a specific surface area 2.0 m2/g or less, 1.5 m2/g or less, 1.0 m2/g or less, 0.01-2 m2/g, 0.1-1 m2/g.