Patent ID: 7001959

Claim:
A process for preparing a copolymer containing 70 to 99% by weight based on the copolymer of polyoxymethylene blocks of the structural repeat units of the formula I and from 1 to 30% by weight blocks containing structural units of the formula II [—O—CH 2 —] x (I), [—O—R 1 —] (II), where R 1 is a divalent radical derived from a hydroxy-terminated aliphatic or cycloaliphatic oligomer or polymer which optionally has ether groups and/or carbonyloxy groups in the chain, and x is a whole number, at least 10 encompassing the following measures: (i) forming an initial charge from monomers which form —O—CH 2 — units together with monomers of the formula V HO—R 1 —OH (V), where R 1 is as defined above, together with a catalyst usually used for polymerizing the monomers forming the —O—CH 2 — units, and optionally together with a solvent, and/or with regulators, and (ii) carrying out the copolymerization at a temperature of from 120 to 300° C. and at a pressure of from 2 to 500 bar.