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US 5,496,920 AGranted
Increasing the molecular weight of polyamides
AssigneeCiba-Geigy Corporation
InventorsRudolf Pfaendner, Kurt Hoffmann, Heinz Herbst
Life of this patent
Estimating the term…
Abstract
An increase in the molecular weight of newly produced polyamides and recycled polyamide materials can be achieved by heating to above the melting point or glass transition point and adding of a bismaleimide and a sterically hindered hydroxyphenyl-alkyl-phosphonic acid ester or half-ester.
Claims9
A process for increasing the molecular weight of polyamides, which comprises heating a polyamide, with addition of a bismaleimide and a sterically hindered hydroxyphenyl-C.sub.1 -C.sub.6 alkyl-phosphonic acid ester or half-ester, above the melting point or glass transition point of the polyamide.
Dependencies are inferred from the claim text.