Process for the continuous production of high molecular weight polyethylene terephthalate
AssigneeZimmer, Inc.
InventorsHans Joachim Rothe, Helmut Heinze, Brian D. Whitehead, Gunther Priepke
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Abstract
This invention relates to a process for the continuous production of high molecular weight polyethylene terephthalate by polycondensation in the solid phase wherein granulated, dried polyethylene terephthalate, having an intrinsic viscosity of at least 0.15, is first crystallized and is thereafter subjected to solid state polycondensation.
Claims13
A process for the continuous production of high molecular weight polyethylene terephthalate by polycondensation in the solid phase from a dried, granulated polyethylene terephthalate, having an intrinsic viscosity of at least 0.15, which comprises crystallizing the granulate to a density of at least 1.390 g/cm3 under forced motion at a temperature of 220.degree. C to 260.degree. C under an inert gas atmosphere, passing the crystallized granulate at a constant or reduced temperature to a continuous fixed bed reactor, and, continuously polycondensing the crystallized granulate in said reactor while in contact with an inert gas stream at a temperature equivalent to, or lower than, the crystallization temperature.
Dependencies are inferred from the claim text.