Sabic Global Technologies B.v.

Donald E Owens, Iii

Ignacio Vic Fernandez

Mark Erik Nelson

Husnu Alp Alidedeoglu

William E Hollar, Jr

Prashant Kumar

Osit Karroonnirun

A process for preparing polybutylene terephthalate (PBT) which includes step of melting solid PBT oligomer having an IV of between 0.13 and 0.17 dL/g and a CEG of between 90 and 180 mmol/kg; and further step of the PBT oligomer polycondensation; wherein the polycondensation process is carried out continuously using a melt tank for melting oligomers, one or more reactors for post-condensation processing, and one or more finishing reactors to increase molecular weight. The resulting PBT has an intrinsic viscosity (IV) of between 0.5 and 1.3 dl/g and a carboxylic end group (CEG) concentration of between 1 and 75 mmol/kg.

Continuous process for making polybutylene terephthalate

In an embodiment, a polycarbonate polymerization process comprises interfacially polymerizing a carbonate compound and dihydroxy compound in the presence of an interfacial catalyst to form a polycarbonate and adding a viscosity reducing agent and a transesterification catalyst to polycarbonate upstream of a first filter to form an adjusted polycarbonate. The first filter can be replaced with a replacement filter and the adjusted polycarbonate can be introduced to the replacement filter. The flow can be diverted to a replacement filter. The process further comprises reducing the addition rate of the viscosity reducing agent and the transesterification catalyst until the addition rate is 0 mol/hr.

Filter alignment in a polycarbonate production process

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Mt. Vernon, IN, United States of America

Donald E Owens, Iii