Nippon Petrochemicals Company, Limited

Masahiro Niwa

Kunimichi Kubo

Mamoru Yoshikawa

Yoshihisa Yamaguchi

Eiko Kobayashi

Shinjiro Suga

Akira Sano

Hideto Kitada

Ken-ichi Uenishi

Yuji Sugano

Makoto Jimbo

A method for polymerizing or copolymerizing .alpha.-olefin in a vapor phase condition by supplying to a reactor a catalyst composed of a solid catalyst component containing at least titanium and/or vanadium as well as magnesium and an organic aluminum compound wherein the current due to the electric charge transferred from polymer particles electrified to an electrode disposed at a position where sheet-like polymers will be produced in a reactor, as a result of contact of the polymer particles in the reactor with the electrode is determined, and the polymerization or copolymerization is carried out under such condition where the mean value of current is zero or a positive value. As a result, it becomes possible to prevent production of sheet-like polymers and to stably continue the reaction for polymerization.

Method for vapor phase polymerization of alpha-olefin

In the polymerization of olefins with a vapor phase fluidized bed reactor, the improvement comprises the steps of feeding seed polymer particles and the reaction is then started after feeding an organoaluminum compound on a prescribed basis, thereby avoiding the formation of sheet-like polymer in the initial period of the reaction and the lowering of the bulk density of the product polymer.

Method of vapor phase polymerization of olefins

In the preparation of polyolefin in a vapor phase polymerization using catalysts comprising a solid catalyst component containing titanium and/or vanadium; and magnesium and an organoaluminum compound, when the reaction is stopped for a certain period of time, the restarting of reaction is possible by feeding in the first place an organoaluminum compound into the reaction system with retaining of polymer particles in the reactor.

Method for operating reactor for polymerizing olefins

In the polymerization of olefins using a catalyst comprising an organoaluminum compound and solid catalyst components containing titanium and/or vanadium; and magnesium in a vapor phase fluidized bed, the formation of sheet-like polymer and other abnormal conditions in the initial stage of the polymerization are avoided by means of previous drying of the reactor by feeding an organoaluminum compound prior to the feeding of seed polymer, the quantity of said organoaluminum compound being calculated by the following equation (I):

Method for drying vapor phase reaction system

Growing community of inventors

Yokohama, Japan

Masahiro Niwa