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AssigneeMitsubishi Kasei Corporation
InventorsNobuyuki Murai, Masayuki Shirato, Hiroshi Takeo, Hidetoshi Tanaka
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A method for the production of polytetramethylene ether glycol wherein polymerization of tetrahydrofuran in the presence of fluorosulfonic acid is followed by hydrolysis of the resulting polymer, characterized by (1) using the fluorosulfonic acid at 0.007-0.3 molar equivalents with respect to the tetrahydrofuran; (2) using in combination therewith fuming sulfuric acid which contains free sulfur trioxide at 0.05-1.0 molar equivalent with respect to the fluorosulfonic acid; and (3) adding said fuming sulfuric acid to the tetrahydrofuran prior to adding the fluorosulfonic acid thereto. According to the method, high quality polytetramethylene ether glycol with a low fluorine content may be obtained at a high yield without lowering the polymerization temperature. For example, PTMG may be obtained with 3 or fewer, and preferably 2 or fewer terminal fluorines per 2,000 termini of the resulting PTMG. As a result, when the resulting PTMG is used as a starting material for elastomers, it is possible to easily obtain a high molecular weight polymer with excellent heat resistance.
A method for the production of polytetramethylene ether glycol which comprises adding fuming sulfuric acid to tetrahydrofuran, then adding fluorosulfonic acid thereto, the fluorosulfonic acid being at 0.007-0.3 molar equivalent with respect to the tetrahydrofuran, the fuming sulfuric acid containing free sulfur trioxide at 0.05-1 molar equivalent with respect to the fluorosulfonic acid, whereby the tetrahydrofuran is polymerized, and then hydrolyzing the resultant polymer to yield polytetramethylene ether glycol wherein the number of terminal fluorines is 3 or less per 2,000 termini of said polymer.
Dependencies are inferred from the claim text.