Patent ID: 6274700
Filing Date: 2001-08-14
Classification: C08G

Abstract:
A process for preparing polytetrahydrofuran, polytetrahydrofuran copolymers or diesters or monoesters thereof by polymerization of tetrahydrofuran in the presence of at least one telogen and/or comonomer selected from water, 1,4-butanediol, 2-butyne-1,4-diol, polytetrahydrofuran having a molecular weight of from 200 to 700, a C.sub.1 -C.sub.20 -monocarboxylic acid, a carboxylic anhydride of a C.sub.2 -C.sub.20 -monocarboxylic acid, 2- or 3-methyltetrahydrofuran, a diol or a mixture of these telogens and/or comonomers over acid-activated montmorillonite catalysts, wherein the montmorillonite catalyst after acid activation has a ratio of montmorillonite structure to the sum of muscovite and kaolin structures, determined from the intensities of the reflections at 2.theta.=5.5.degree. for montmorillonite, 2.theta.=9.0.degree. for muscovite and 2.theta.=12.5.degree. for kaolin measured in the X-ray powder pattern, of at least 5:1.