Increasing the molecular weight of polyesters
AssigneeCiba Specialty Chemicals Corporation
InventorsKarin Regel, Roland Andernach, Peter Schwarz, Heinz Herbst, Kurt Hoffmann, Rudolf Pfaendner, Dirk Simon
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Abstract
This invention relates to a process for increasing the molecular weight of polyesters, copolyesters or polyester blends by adding an organic phosphate to the processing apparatus and fusing the mixture to above the melting point, in which process the processing apparatus is a single-screw extruder, twin-screw extruder, planetary-gear extruder, ring extruder or co-kneader having at least one vent zone to which underpressure is applied.
Claims13
A process for increasing the molecular weight of polyesters, copolyesters or polyester blends by adding one or more than one phosphonate to the processing apparatus and fusing the mixture to above the melting point, in which process the processing apparatus is a single-screw extruder, twin-screw extruder, planetary-gear extruder, ring extruder or Ko-kneader having at least one vent zone to which underpressure is applied.
Dependencies are inferred from the claim text.