Process for the stabilization of HDPE
OwnerKurt Hoffmann, Heinz Herbst +1inventors
InventorsKurt Hoffmann, Heinz Herbst, Rudolf Pfaendner
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Abstract
High-density polyethylene (HDPE) which experiences a reduction in molecular weight during processing and is obtainable by means of catalysts of the Ziegler-Natta type can be stabilized against thermo-oxidative degradation by addition of a combination of a sterically hindered phenol and an organic phosphite or phosphonite and calcium oxide.
Claims16
Stabilized high-density polyethylene (HDPE) which experiences a reduction in molecular weight during processing, comprising a mixture, preferably from 0.05 to 15% by weight, of a) at least one sterically hindered phenol, b) at least one organic phosphite or phosphonite and c) calcium oxide.
Use of a stabilizer mixture comprising a) at least one sterically hindered phenol, b) at least one organic phosphite or phosphonite and c) calcium oxide for the stabilization of high-density polyethylene (HDPE) which experiences a reduction in molecular weight during processing.
A process for the stabilization of high-density polyethylene (HDPE) which experiences a reduction in molecular weight during processing, which comprises adding a) at least one sterically hindered phenol, b) at least one organic phosphite or phosphonite and c) calcium oxide to the polyethylene.
Dependencies are inferred from the claim text.