Polyhydropolyborates as polymerization catalysts

The present invention relates to a synthetic method comprising contacting at least one diaryl carbonate with one or more dihydroxy aromatic compounds in the presence of a transesterification catalyst under melt polymerization conditions to afford a product polycarbonate. The transesterification cata...

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Bibliographische Detailangaben
1. Verfasser:	LEMMON, JOHN PATRICK
Format:	Patent
Sprache:	eng
Schlagworte:	CHEMISTRY COMPOSITIONS BASED THEREON COMPOUNDS THEREOF INORGANIC CHEMISTRY MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS METALLURGY NON-METALLIC ELEMENTS ORGANIC MACROMOLECULAR COMPOUNDS THEIR PREPARATION OR CHEMICAL WORKING-UP
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Beschreibung
Zusammenfassung:	The present invention relates to a synthetic method comprising contacting at least one diaryl carbonate with one or more dihydroxy aromatic compounds in the presence of a transesterification catalyst under melt polymerization conditions to afford a product polycarbonate. The transesterification catalysts used according to the method of the present invention are polyhydropolyborates in combination with tetraalkylammonium or tetraalkylphosphonium compounds which serve as co-catalysts. The transesterification catalysts employed according to the method of the present invention provide polycarbonates having reduced levels of Fries rearrangement product relative to conventionally employed catalysts such as sodium hydroxide in combination with tetramethylammonium hydroxide co-catalyst.