Verfahren zur Herstellung von Copolyestern

摘要

The invention relates to a process for the preparation of copolyesters (A): copolycarbonates or polyestercarbonates, using cyclic esters (B): or carbonates as monomers and a metallic salt of the formula Me<2+>X2 as catalyst. Me<2+> represents Ca, Fe(II), Mg, Mn(II) or Zn, and X is an anion of an aminocarboxylic acid, hydroxycarboxylic acid or a halide. Monomer and catalyst are used in a monomer/catalyst ratio of greater than 100. Zinc lactate is a preferred catalyst and its preparation is also claimed.