Patent ID: 7718041

Claim:
A process for obtaining oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers from a methanolic crude product which contains polytetrahydrofuran or tetrahydrofuran copolymers and is obtained in the transesterification of the mono- and/or diesters of polytetrahydrofuran or tetrahydrofuran copolymers with methanol, which comprises: a) removing the majority of the methanol from the crude product in a distillation stage; b) separating the resulting bottom product by distillation into a top fraction comprising the oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers, and polytetrahydrofuran or tetrahydro furan copolymer; and c) condensing the oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers out of the top fraction from stage b).