Process for producing polytetramethylene ether glycol diester on aluminium magnesium silicate catalysis
US6271413A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 3, 1997 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Dec 3, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D307/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
An improved process for the preparation of polytetramethylene ether glycol diesters of the formula EQU R--CO--O(--CH.sub.2 -CH.sub.2 -CH.sub.2 -CH.sub.2 -O).sub.n -COR.sub.1 in which R and R.sub.1 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.