Nippon Shokubai Co., Ltd.

Other

Dai-Ichi Kogyo Seiyaku Co., Ltd.

Shigetaka Takamiya

Michiyuki Kono

Tsukasa Takahashi

Manabu Kikuta

Masahito Nishiura

Taketo Toba

Fumihide Tamura

Kenji Nakahara

Koichiro Saeki

Toshiaki Kuriyama

Kazuo Takei

Masashi Yukitake

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

The present invention provides a novel production process for an ethylene oxide resin, in which, when the ethylene oxide resin is obtained, it is arranged that the resin should contain no antistatic agent, and further its water content is also easily controlled in not more than a definite amount, and the thermal damage of the above resin is prevented, and besides, the reduction of the cost can also be actualized. The production process for an ethylene oxide resin, according to the present invention, comprises the step of carrying out devolatilization of a solvent from a polymerization reaction liquid containing the solvent, thereby obtaining the ethylene oxide resin; with the production process being characterized by arranging that: after the devolatilization, the resin should have a solvent concentration of 0.01 to 30 weight % and a water content of not more than 200 ppm, and the resin should contain no antistatic agent.

Production process for ethylene oxide resin

A reversely subliming substance is efficiently collected on a commercial scale from a gas containing the substance. This is achieved by introducing the gas containing the substance into a shell-and-tube collecting apparatus by controlling the resistance offered to the gas during the passage thereof through the cooled tubes retained inside the collecting apparatus or by utilizing gas-introducing tubes excelling in dispersibility.

Method for collecting reversely subliming substance and apparatus therefor

A method for producing crystals of pyromellitic dianhydride is disclosed which is characterized by setting the water content of an atmosphere used in handling the crystals of pyromellitic dianhydride at a temperature of not higher than 120&deg; C. at a level of not more than 4 vol. %. Particularly by supplying an inert gas having a water content of not more than 4 vol. % to the step of production, it is made possible to prevent the conversion of pyromellitic dianhydride by hydration very efficiently.

Method for production of pyromellitic dianhydride

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Himeji, Japan

Shigetaka Takamiya