Kyowa Chemical Industry Co., Ltd.

Harumi Takabatake

Tsutomu Nosu

Makoto Yoshii

A process for purifying a crude polyether, comprising contacting a crude polyether obtained by addition polymerizing an active hydrogen-containing compound with an alkylene oxide compound in the presence of an alkali metal-containing basic catalyst to an adsorbent comprising a synthesized hydrous magnesium silicate compound which satisfies the following requirements (1) to (5) in order to reduce the alkali metal content of the crude polyether: (1) it is represented by the following formula I:(CaO).(MgO).(AlO).SiO.mHOIwherein x, y, z and m satisfy the following ranges:x&#x3c;y, z&#x3c;y, 0&#x2266;x&#x2266;0.1, 0.6&#x2266;y&#x2266;0.6, 0&#x2266;z&#x2266;0.1 and 0.1&#x2266;m&#x2266;1.5, (2) it is amorphous according to the analysis of its powder method X-ray diffraction diagram, (3) it has a BET specific surface area of 100 to 400 m/g, (4) it has an alkali metal content of 0.1 wt % or less, and (5) it has an average particle diameter of 2 to 60 &#x3bc;m. According to the present invention, a purified polyether having an extremely low content of an alkali metal can be obtained effectively.

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Sakaide, Japan

Harumi Takabatake