Process for producing polytetramethylene ether glycol diester on aluminium magnesium silicate catalysis
AssigneeKorea PTG Co., Ltd.
InventorHerbert Müller
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Abstract
An improved process for the preparation of polytetramethylene ether glycol diesters of the formula R—CO—O(—CH2-CH2-CH2-CH2-O)n-COR1 in which R and R1 are identical or different and are an alkyl radical or a derivative thereof, by polymerization of tetrahydrofuran in the presence of a fixed-bed polymerization catalyst and a carboxylic acid anhydride. Through use of neutral or weakly basic magnesium-aluminium hydrosilicates instead of the known acidic montmorillonite, zeolite or kaolin catalysts, polymers with more uniform properties and a narrower molecular weight distribution are obtained at a higher rate of polymerization, even when technical-grade tetrahydrofuran is used.
Claims16
A process for the preparation of polytetramethylene ether glycol diesters of the formula
- R—CO—O(—CH2-CH2-CH2-CH2-O)n-COR1 wherein R and R1 are identical or different and are each an alkyl radical or a derivative thereof, and n is an integer from 2 to 200, comprising polymerizing tetrahydrofuran in the presence of a polymerization catalyst comprising a calcined magnesium-alminum hydrosilicate, wherein said magnesium-aluminum hydrosilicate is neutral, weakly basic or protonated and is a natural or synthetic attapulgite or sepiolite.
Dependencies are inferred from the claim text.