Ytterbium(III)acetylacetonate as catalyst for the preparation of aliphatic oligocarbonate-polyols

摘要

Oligocarbonate diols (I) having a number average mol. wt. of 500-5000 g/mol are prepared by transesterification of organic carbonates with aliphatic polyols in the presence of ytterbium (III) acetylacetonate. An independent claim is included for an NCO-terminated polymer prepared by reaction of a stoichiometric excess of organic (poly)isocyanates with oligocarbonate diols (I).