Mitsui Petrochemical Industries, Ltd.

Yoshinori Morita

Norio Kashiwa

Akifumi Kato

Akinori Toyota

Hajime Inagaki

Ryoichi Yamamoto

Satoru Ohtani

Kenji Doi

Hiroshi Inoue

Hiroshi Nishikawa

Akio Ohdaira

Koji Horimoto

Michiharu Suga

Shinzi Hayata

Kenji Fujiyoshi

Yutaka Haneda

Kenichi Nishiwaki

Yoshikuni Itoh

Tohru Watanabe

Hideo Nara

Yasunori Kabu

Masanori Motowoka

Ryoji Ohori

Masayoshi Yasunaka

Takashi Yamanaka

Eigo Miura

In a gas phase olefin polymerization, an olefin is continuously fed to a fluid bed reactor in which a metallocene catalyst is present. At least one compound selected from water, alcohols and ketones is added in a specified amount simultaneously with the feeding of the olefin. Thus, an olefin polymer having a satisfactory drop second count index as defined by the below indicated formula is produced: ##EQU1## wherein t.sub.0 and t respectively represent a flow time measured in the flow test according to ASTM D-1775 of the olefin polymer obtained when none of the water, alcohols and ketones is incorporated in the reactor, and when at least one compound of water, alcohols and ketones is incorporated in the reactor. The flowability of the polymer formed in the reactor is excellent, so that blocking, bridging and the like do not occur during the gas phase polymerization. Thus, it is feasible to stably produce a (co)polymer having excellent particle properties in high yield for a prolonged period of time.

Process for gas phase polymerization of olefin

Method for the pyrolysis of polymers

An absorbent web structure composed of a mixture of 5 to 50% by weight of short fibers of a thermoplastic resin rendered hydrophilic with a surface-active agent and 95 to 50% by weight of cellulosic fibers, said thermoplastic short fibers being melt-bonded to impart self-supporting property to the web structure; characterized in that

Absorbent web structure

A process for producing a random terpolymer of ethylene and alpha-olefins having at least 3 carbon atoms in the presence of a catalyst composed of (1) a titanium catalyst component containing at least magnesium and titanium and (2) an organoaluminum catalyst component in a hydrocarbon solvent at a temperature above the melting point of the terpolymer formed, under such conditions that the resulting copolymer dissolves in the hydrocarbon solvent; characterized in that said terpolymer consists essentially of

Process for producing random ethylene terpolymer

In a process for polymerizing a monomer capable of being formed, upon polymerization, into a solution having an upper cloud point of the corresponding polymer in a reaction medium being liquid under the reaction conditions, the polymerization being carried out under such conditions that the resulting polymer dissolves in the reaction medium; the improvement wherein

Polymerization process

In a process for polymerizing olefins in the gaseous phase in a first gas-phase polymerization zone and a second gas-phase polymerization zone, which are provided independently from each other, in the presence of a catalyst composed of a transition metal catalyst component and an organometallic compound of a metal of Groups I to III of the periodic table while feeding the catalyst-containing polymer formed in the first zone to the second zone; the improvement wherein

Process for multi-step gas-phase polymerization of olefins

In a process for polymerizing olefins in the gaseous phase in a first gas-phase polymerization zone and a second gas-phase polymerization zone, which are provided independently from each other, in the presence of a catalyst composed of a transition metal catalyst component and an organometallic compound of a metal of Groups I to III of the periodic table and in the co-presence of hydrogen gas while feeding the catalyst-containing polymer formed in the first zone to the second zone; the improvement wherein (i) a dilution zone for diluting a feed flow from the first gas-phase polymerization zone which comprises a mixture of the polymer, the catalyst, the olefin gas and hydrogen gas by feeding a fresh supply of olefin gas thereto is provided in a feed passage for feeding said flow from the first gas-phase polymerization zone to the second gas-phase polymerization zone, (ii) a part of the gas phase in said feed flow diluted in the dilution zone is recycled to the first gas-phase polymerization zone, and remainder is fed into the second gas-phase polymerization zone, and (iii) in the second gas-phase polymerization zone, the hydrogen to olefin mole ratio is maintained lower than that in the first gas-phase polymerization zone.

Multi-step gas-phase polymerization of olefins

A process for polymerizing or copolymerizing an .alpha.-olefin in the presence of a catalyst composed of (A)' a transition metal catalyst component resulting from supporting a halogen-containing transition metal compound on spray-dried solid spherical particles of a magnesium compound and (B)' an organometallic compound of a metal of Groups I to III of the periodic table, wherein the transition metal catalyst component (A)' is a catalyst component (A) prepared by supporting the halogen-containing transition metal compound on solid spherical particles having a specific surface area of at least 20 m.sup.2 /g and an average particle diameter of 5 to 300.mu. obtained by spray-drying a suspension of an oxygen-containing, halogen-free magnesium compound having an average particle diameter of 0.01 to 20.mu., and a catalyst composition for use therein.

Process for polymerizing olefins and catalyst therefor

In a process for the production of a chemically blended composition of non-elastomeric ethylene resins in a multiplicity of steps in the presence of a catalyst composed of a transition metal catalyst component and an organometallic compound, which comprises (a) a step of forming (i) an ethylene polymer or an ethylene/alpha-olefin copolymer having an alpha-olefin content of up to 15% by weight, said polymer or copolymer (i) having an intrinsic viscosity [.eta.] of 0.3 to 3, and (b) a step of forming (ii) an ethylene/alpha-olefin copolymer having an alpha-olefin content of 0.2 to 30% by weight which is more than that of the polymer or copolymer (i), said copolymer (ii) having an intrinsic viscosity [.eta.] of 1 to 12 which is at least 1.5 times that of the polymer or copolymer (i), said step (a) being performed first and then step (b) being performed in the presence of the product of step (a), or step (b) being performed first and then step (a) being performed in the presence of the product of step (b), the improvement wherein in steps (a) and (b), ethylene is polymerized or copolymerized with the alpha-olefin

Process for production of chemically blended composition of

A process for producing an ethylene copolymer having a density of from 0.900 to 0.945 g/cm.sup.3 by copolymerizing in two steps a predominant amount of ethylene with a minor amount of an alpha-olefin containing at least 3 carbon atoms at room temperature to not more than about 100.degree. C. under a pressure of about 1 to about 100 kg/cm.sup.2 in the presence of a catalyst composed of (A) a titanium catalyst component supported on a magnesium compound and (B) an organoaluminum compound; characterized in that said copolymerization is carried out in

Process for preparing low density ethylene copolymers

A copolymer consisting essentially of ethylene and an .alpha.-olefin with 5 to 18 carbon atoms, said copolymer having

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Iwakuni, Japan

Yoshinori Morita