Showa Denko K.k.

Japan Polyethylene Corporation

Japan Polyolefins Co., Ltd.

Mitsubishi Chemical Corporation

Takashi Monoi

Hidenobu Torigoe

Shintaro Inazawa

Masakazu Yamamoto

Yoshimitsu Ishihara

Shigenobu Miyake

Nobuyuki Kibino

Satoshi Kanazawa

Kouichi Ogawa

Hiroyuki Ohira

Yasunori Takemoto

Kazuhiro Yamamoto

Hiroki Emoto

Takaaki Hattori

Keiichi Yoshimoto

Yuuichi Kuzuba

Ritsuya Matsumoto

Shinya Waki

Kazuyuki Yokoyama

Shigeki Saito

Haruhiko Ikeda

An object of the invention is to provide an ethylene-based polymer excellent in moldability and durability, and also excellent in the balance of stiffness and durability, and to provide a molded product of hollow plastic using the ethylene-based polymer. The ethylene-based polymer according to the invention is an ethylene-based polymer having specific characteristics and manufactured by a homopolymerization of ethylene or a copolymerization of ethylene and &#x3b1;-olefin using a chromium catalyst.

Ethylene-based polymer, manufacturing method of ethylene-based polymer and manufacturing method of catalyst for polymerization, and molded article of hollow plastics containing ethylene-based polymer and use thereof

The object of the present invention is to provide a production method for a polyolefin, in which catalyst activity is improved, and a polyolefin such as a linear low density polyethylene can advantageously be industrially produced. The present invention relates to a production method for a polyolefin, in which in producing a polyolefin by the polymerization reaction of an olefin using a catalyst, an organohalide is present in the reaction system in an amount of from 0.05 to 10 ppm by weight in terms of the halogen atom as a concentration in a raw material olefin, and 1-hexene for linear low density polyethylene production raw material, containing an organohalide in an amount of from 0.05 to 10 ppm by weight in terms of the halogen atom.

Production method of polyolefin, polyolefin and 1-hexene for linear low density polyethylene production raw material

A polyethylene based resin exhibiting excellent moldability and durability and having an excellent balance between impact resistance and stiffness; and a hollow plastic molded article using the foregoing resin, which exhibits excellent moldability, durability and barrier properties and has an excellent balance between impact resistance and stiffness, are provided. The polyethylene based resin satisfies the following requirements (1) to (4): (1) a high-load melt flow rate (HLMFR) is from 1 to 100 g/10 min; (2) a density is from 0.940 to 0.960 g/cm; (3) a strain hardening parameter &#x3bb;max of elongational viscosity is from 1.05 to 1.50; and (4) a rupture time in a full notch tensile creep test and a density satisfy the following relational expression (A): log(rupture time)&#x2267;&#x2212;355&#xd7;(density)+337.6(A).

Polyethylene based resin, producing catalyst for the same, method for producing the same, hollow plastic molded article containing polyethylene based resin, and use of the same

A method for producing an ethylene polymer which comprises continuously polymerizing ethylene alone or copolymerizing ethylene and a C-C&#x3b1;-olefin by multistage polymerization in a plurality of polymerization reactors connected in series in the presence of a chromium catalyst having at least a part of chromium atoms converted to hexavalent chromium carried on an inorganic oxide carrier by calcination-activating in a non-reducing atmosphere, wherein an organoaluminum compound of the formula (1):(R)Al(OR)(OSiRRR)&#x2003;&#x2003;(1)(in the above formula, Rand Rmay be the same or different, each represents a C-Calkyl group or a C-Caryl group, R, Rand Rmay be the same or different, each represents a C-Calkyl group or a C-Caryl group, R, ORand OSiRRRrespectively may be the same or different when each has a plurality of kinds, and x, y and z are respectively 0&#x2266;x&#x2266;3, 0&#x2266;y&#x3c;3, 0&#x2266;z&#x3c;3, and x+y+z=3) is introduced at least one or all of the polymerization reactors.

Ethylene polymer, catalyst for producing thereof and method for producing thereof

The invention relates to a method for producing an ethylene polymer, comprising performing polymerization of ethylene in co-presence of hydrogen using a trialkylaluminum compound-carried chromium catalyst, wherein the chromium catalyst is obtained by calcination-activating a chromium compound that is carried on an inorganic oxide carrier in a non-reducing atmosphere to convert chromium atoms in the chromium compound into hexavalent chromium atoms for at least a portion thereof, and treating with a trialkylaluminum compound in an inert hydrocarbon solvent to carry thereon and removing to dry the solvent so that the chromium atoms are not over-reduced by the trialkylaluminum compound, and to an ethylene polymer suitable for blow molded articles obtained by the production method. The ethylene polymer of the invention have improved environment stress crack resistance (ESCR) and impact resistance in a good balance and are suitable for molded blow articles, in particular large size blow molded articles.

Ethylene polymers and method for producing the same

A catalyst for the production of an ethylene polymer comprising a specific trivalent alkyl chromium compound, an inorganic oxide solid and optionally an organoaluminum compound (first catalyst), a catalyst for the production of an ethylene polymer comprising the specific trivalent alkyl chromium compound, a specific tetravalent alkyl chromium compound and an inorganic oxide solid (second catalyst) and a process for producing an ethylene polymer using those catalysts. The first catalyst of the present invention does not cause deterioration with the passage of time, is stable to heat and light, has greatly improved activity and can efficiently produce an ethylene copolymer with &agr;-olefin. The second catalyst of the present invention can efficiently produce an ethylene polymer having low molecular weight and narrow molecular weight distribution suitable for use in injection molding or an ethylene polymer having excellent balance between rigidity and ESCR and also excellent moldability suitable for use in blow molding or film molding.

Catalyst for the production of ethylene polymer and process for producing ethylene polymer

Process for preparing ethylene polymer and catalyst used therefor

Ethylenic polymers and process for the production thereof

Preparation method of ethylene base polymer

A process for the production of ethylenic polymers is disclosed in which an ethylenic monomer is polymerized in the presence of a catalyst comprising a chromium compound, an alumoxane and an organometallic alkoxide and/or organometallic siloxide and a carrier supporting thereon these compounds. The resultant polymer has a balanced proportion of rigidity and environmental stress cracking resistance (ESCR) and an excellent moldability property.

Process for the production of ethylenic polymers

An ethylenic polymerization catalyst comprising (A) a chromium compound, (B) a carrier, (C) aluminoxane, and (D) a transition metal compound comprising a group having conjugated .pi. electron as a ligand, wherein said chromium compound (A) is not calcined; and a process for producing an ethylenic polymer comprising a step of polymerizing a monomer comprising ethylene in the presence of the ethylenic polymerization catalyst.

Ethylenic polymerization catalyst

A metallocene having an asymmetric ligand which is represented by the formula below and its enantiomer: ##STR1## and a process for producing a polyolefin using the same as a catalyst component. The metallocene and its enantiomer are particularly effective in the production of highly stereospecific polyolefins.

Metallocene and process for producing polyolefin using the same

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Oita, Japan

Takashi Monoi