Idemitsu Petrochemical Co., Ltd.

Kazutoshi Ishikawa

Hideki Imabayashi

Koji Yamamoto

Takashi Izumi

Hideo Teshima

Yoshihiko Ishida

Hisashi Ase

There is disclosed a process for continuously producing a highly syndiotactic styrenic polymer by using a horizontal self-cleaning type reactor which comprises feeding into the reactor, a catalyst or both the catalyst and a styrenic monomer dividedly into at least two portions, preferably 2 to 5 portions in the direction of the axis of the reactor. The above process facilitates the control for the reactor inside temperatures because of the stepwise feeding of the catalyst (and the styrenic monomer) and remarkably enhances the productivity by simply increasing the feed rates of the catalyst and the styrenic monomer, thus making itself industrially highly valuable.

Process for producing styrenic polymer

There is disclosed a process for continuously and efficiently producing a styrenic polymer having a high degree of syndiotactic configuration which comprises effecting polymerization reaction by continuously introducing a styrenic monomer and a polymerization catalyst into a polymerization reactor, the inside of which has been brought into fluidized state by particles previously fed therein, which process is characterized in that the polymerization reactor temperature is controlled by vaporizing a part of the styrenic monomer which has been introduced into the polymerization reactor, while the inside of the reactor is maintained under reduced pressure. According to the above process, such problems as difficulty in polymerization reactor scale-up, adhesion of polymer to the reactor inside and polymer particle agglomerate are simultaneously solved, and thereby the industrial significance of the process is remarkably enhanced.

Disclosed is a process for producing a styrene-based polymer having syndiotactic configuration, which comprises continuously polymerizing styrene or styrene-based derivatives in a self-cleaning type reactor, while providing a sufficient shearing force to maintain a polydispersive state at a temperature of not more than 120.degree. C. According to the present invention, a styrene-based polymer having syndiotactic configuration can be produced efficiently and continuously, without adhesion of the polymer to the reactor and agitation blades.

Process for producing styrene-based polymers

A process for continuously producing a styrene-based polymer having high syndiotactic configuration which comprises continuously introducing a styrene-based monomer into a reactor and polymerizing to while adjusting the amount of the polymer produced in the reactor to at least 10% by weight of the total amount of the unreacted styrene-based monomer and the polymer. According to the present invention, the styrene-based polymer with high syndiotactic configuration is effectively produced with small power consumption.

Process for producing mainly syndiotactic styrene-based polymers

A process for producing a styrene-based polymer having a high syndiotactic configuration, which comprises polymerizing a styrene-based monomer with addition of catalyst in such amounts that the conversion at 30 minutes after the polymerization starts becomes 2 to 50%, and then continuing the polymerization with additions of the catalyst when the conversion exceeds 10%. According to the process, the productivity can be improved while easily attaining safe running of the reactor and successful controlling of reaction heat.

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Ichihara, Japan

Kazutoshi Ishikawa