Nippon Shokubai Co., Ltd.

Dai-Ichi Kogyo Seiyaku Co., Ltd.

Nippon Shokubai

Masashi Yukitake

Hiroshi Itoh

Hiroya Kobayashi

Takashi Namba

Toshiaki Kuriyama

Michiyuki Kono

Kenji Minami

Masahito Nishiura

Manabu Kikuta

Koichiro Saeki

Taketo Toba

Fumihide Tamura

Kazuo Takei

Shigetaka Takamiya

The present invention provides a production process, in which, when an ethylene oxide copolymer is obtained, conditions for obtaining this copolymer having a desirable molecular weight with ease and good reproducibility are provided. The production process for an ethylene oxide copolymer, according to the present invention, comprises the step of carrying out polymerization of a monomer mixture under stirring in a solvent, thereby obtaining the ethylene oxide copolymer, wherein the monomer mixture includes ethylene oxide and a substituted oxirane compound of a structural formula (1) as essential raw materials; with the production process being characterized in that the stirring is carried out by a stirring power of not less than 0.6 kW/m.

Production process for ethylene oxide copolymer

A process for producing a high-molecular-weight polydioxolane, which includes the steps of: polymerizing 1,3-dioxolane using a polymerization catalyst comprising a heteropolyacid and a ketone; and neutralizing the resulting polymerization reaction product using an organic amine and/or ammonia. A hydrophilic film, which includes a resin including a polydioxolane and having a particular molecular weight and has a particular crystallinity and a particular spherulite's size. A film crumbly in cold water is produced by forming a film under particular forming conditions from a resin including a polydioxolane and having a particular molecular weight, or by subjecting an already formed film to particular thermal hysteresis.

Production process for making high molecular weight polydioxolane

This invention provides a process for producing with industrially good efficiency a polyester having a high melting point and biodegradability. In this process, ring-opening copolymerization of a cyclic acid anhydride containing succinic anhydride as a main component with a cyclic ether containing ethylene oxide as a main component is carried out in the presence of a catalyst by introducing successively the cyclic ether into a reaction vessel containing the cyclic acid anhydride in a melting state or solution state. The rate per hour of introducing the cyclic ether is within the range of 3 to 90 parts by weight per 100 parts by weight of the cyclic acid anhydride, and the reaction vessel has an inside pressure within the range of atmospheric pressure to 50 kgf/cm.sup.2 as a gauge pressure.

Process for producing polyester by ring-opening copolymerization

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Suita, Japan

Masashi Yukitake