Process for the solid state polycondensation of linear polyesters
AssigneeZimmer, Inc.
InventorsWerner Gey, Wolfgang Langhauser, Helmut Heinze, Hans-Joachim Rothe, Peter Freund
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Abstract
A separating or anticaking agent consisting of spherical glass particles having a diameter of 3 to 30.mu. is added to polyester resin granulates to prevent agglomeration during solid state polycondensation in a plug-flow reactor. Thin-walled articles formed from the end product are characterized by high strength, high transparency, crystal clear color, good gas impermeability and a smooth surface.
Claims4
Process for solid-state polycondensation of linear polyesters in granulated form comprising moving the granulate in an inert gas stream at temperatures of 30.degree. to 5.degree. C below the melting point of the polymer continuously through a reaction vessel, and preventing agglutination of the granulate by an addition of fine-particle glass as a separating agent, characterized in the prior to entering the reactor there is admixed with the granulate 0.2 to 5% by weight of a glass powder having particles of substantially spherical form with a diameter between about 3 and 30.mu..
Dependencies are inferred from the claim text.