Nova Patents
EP1577333A3

Method of polycarbonate preparation

Abstract

Polycarbonates containing low or undetectable levels of Fries rearrangement product may be prepared by the melt reaction of a dihydroxy aromatic compound such as bisphenol A with an ester-substituted diaryl carbonate such as the diaryl carbonate of methyl salicylate, bis-methyl salicyl carbonate. Low levels of Fries product are obtained as the combined result of a highly effective catalyst system which suppresses the Fries reaction and the use of lower melt polymerization temperatures relative to temperatures required for the analogous polymerization reaction using diphenyl carbonate.

Term

Term ended

Projected expiry passed 13 May 2022, 4.4 years ago.

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Every citation, both ways

Citations
DocumentRelationOfficeCategoryCited duringRelevant claims
EP0338085A1CitesEuropean Patent Office (EPO)XSearch report1-15
EP0360578A2CitesEuropean Patent Office (EPO)XSearch report1-15
EP0764673A2CitesEuropean Patent Office (EPO)XSearch report15
DE4223016A1CitesGermanyXSearch report1-15
US4323668ACitesUnited States of AmericaXSearch report1-15
US6252035B1CitesUnited States of AmericaXSearch report15