Process for the preparation of aliphatic oligocarbonate diols from dimethyl carbonate and aliphatic diols

摘要

The present invention relates to an improved process for the preparation of aliphatic oligocarbonate diols from non-vicinal diols by transesterification with dimethyl carbonate (DMC) in a gas-liquid countercurrent apparatus and subsequent removal of residues of methanol and traces of dimethyl carbonate in an apparatus which produces gas bubbles. The catalyst dissolved in the finished oligocarbonate can either be separated off or masked by adding complexing agents and left in the oligocarbonate.