Idemitsu Kosan Company, Limited

Minolta Camera Kabushiki Kaisha

Satoshi Asahi

Hiroshi Hayashi

Junji Machida

Junji Ohtani

Kouichi Matono

Kazuo Ota

Yasuhiro Takeshita

Akio Kimura

Kenji Seki

Shuji Machida

Masami Watanabe

Hiroshi Maezawa

Michitake Uoi

Junichi Matsumoto

Sanae Tagami

Yoshihisa Terasaka

Shigeyoshi Mizogami

Mamoru Ukita

Shigeo Mori

Koichi Matono

Hideki Aiura

The present invention provides an aryl styrene-based polymer of a degree of polymerization of at least 5 having recurring units represented by the general formula ##STR1## in the formula, R.sup.1 to R.sup.5 each denote a hydrogen atom, halogen atom or substituent group containing at least either one kind of a carbon atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, selenium atom, silicon atom and tin atom and at least one of the R.sup.1 to R.sup.5 denotes an aryl group having a hydrogen atom, aryl group having a halogen atom or aryl group having a substituent group containing at least either one kind of a carbon atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, selenium atom, silicon atom and tin atom, of which the stereospecificity is a mainly syndiotactic configuration and a method for the preparation thereof as well as a styrene-based copolymer and a method for the preparation thereof. The aryl styrene-based copolymer of the-present invention has a high syndiotacticity and is excellent in the heat resistance, resistance against chemicals and electric properties. Further, the styrene-based copolymer of the present invention has a high syndiotacticity and, in addition, has a wide temperature range suitable for melt molding or is excellent in the heat resistance. Accordingly, the present invention can be effectively utilized as heat-resistant resins, base materials of films and the like.

Aryl styrene-based copolymer

A process for producing a norbornene polymer consisting essentially of a repeating unit of the formula (I) ##STR1## wherein R.sup.1 to R.sup.12 are the same or different and are hydrogen, C.sub.1 -C.sub.20 hydrocarbon, or a group having a halogen, oxygen or nitrogen, R.sup.5 and R.sup.7 may combine to form a ring, and n is an integer of 0 or more; and having a weight average molecular weight as determined by GPC of 1.times.10.sup.5 to 1.times.10.sup.7. The process comprises polymerizing a norbornene monomer of the formula (II) ##STR2## wherein R.sup.1 to R.sup.12 are the same or different and are independently hydrogen, C.sub.1 -C.sub.20 hydrocarbon, or a substituent containing a halogen atom, an oxygen atom or a nitrogen atom; R.sup.5 and R.sup.7 may combine together to form a ring; and n is an integer of 0 or more, in the presence of a catalyst containing a transition metal compound component containing a transition metal belonging to Group VB, VIB, VIIB or VIII of the Periodic Table, and an aluminoxane components.

Process for producing a norbornene polymer

The present invention provides a polyolefinic resin-coated carrier having a rough surface and containing a core material in a quantity of 90 or more % by weight. Said resin-coated layer may contain fine particles having a charge-controlling function and/or electrically conductive fine particles as additives.

Polyolefinic resin-coated uneven carrier

The present invention provides a carrier of a two component developer for developing electrostatic latent images comprising;

Polyolefinic resin-coated carrier with irregular surface

The present invention provides fine particles comprising core particles and polyolefinic resin layers for composing an electrostatic latent image developer, characterized in that the polyolefinic resin layers are formed by polymerizing olefinic monomers on surfaces of the core particles.

Fine particles composing developer for electrophotography

Polyolefinic resin-coated uneven electrophotographic carrier particles

A process for producing a polyethylene composition which comprises polymerizing ethylene in the presence of a catalyst comprising (A) a contact treatment product of (a) a high activity catalyst component and (b) a filler, and (B) an organoaluminum compound. This process has no need for a deashing step, i.e., a step to remove the catalyst after polymerization, since the catalyst has a remarkably high activity. In the polyethylene composition produced, the filler is dispersed uniformly and the separation of the filler from the polyethylene is scarcely observed.

Process for the production of polyethylene compositions

A process for the stereospecific polymerization of .alpha.-olefins which comprises polymerizing an .alpha.-olefin with a catalyst comprising (A) the reaction product of a magnesium compound and a titanium compound and (B) an organo-aluminum compound. Component (A) is prepared by reacting a (i) magnesium compound of the formula Mg(OR.sup.1).sub.n X.sup.1.sub.2-n wherein R.sup.1 contains from 1 to 10 carbon atoms and is an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group, X.sup.1 is a halogen atom, and n is a real number of from 1.0 to 2.0, with (ii) at least one halogen-containing compound selected from the group consisting of halogenated hydrocarbons, oxygen-containing halogenated hydrocarbons, halogenated thionyls, halogen-containing phosphorus compounds and halogen-containing nitrogen compounds, and (iii) an oxygen-containing titanium compound of the formula Ti(OR.sup.2).sub.4 wherein R.sup.2 contains from 1 to 10 carbon atoms and is an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group, (iv) in the presence or in the absence of an organic acid ester to produce a solid reaction product. Said solid reaction product is, as it is or after a pre-treatment with an organic acid ester, reacted with a halogen-containing tetravalent titanium compound of the formula Ti(OR.sup.3).sub.m X.sup.2.sub.4-m wherein R.sup.3 contains from 1 to 10 carbon atoms and is an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group, X.sup.2 is a halogen atom, and m is a real number of from 0 to 3.0, in the presence or in the absence of an organic acid ester, and always in the presence of an organic acid ester when an organic acid ester was not used in at least one of the preceding steps.

Catalyst and process for stereospecific polymerization of .alpha.-olefins

A process for producing an improved titanium catalyst for use in the polymerization of olefins comprising heating a magnesium dialkoxide and an alcohol adduct of a magnesium dihalide to form a solid product, treating said solid product with an alcohol to form an alcohol treated solid product, and then reacting said alcohol treated solid product with a halogen-containing titanium compound. The reaction product of said alcohol treated solid product with the halogen-containing titanium compound may optionally be reacted with an organoaluminum compound. The products of the processes described in the preceding two sentences is an improved titanium catalyst which is generally used with an organoaluminum olefin polymerization cocatalyst.

Titanium catalyst for the polymerization of olefins

Ethylene is polymerized in the presence of a catalyst comprising: (A) the reaction product of a magnesium compound and titanium halide and (B) an organic aluminum compound wherein Component A is prepared by reacting magnesium dialkoxide with a halogen-containing silicon compound and an alcohol to provide a solid material and then reacting the solid material with titanium halide in the presence of an alkoxy-containing silicon compound.

Process for polymerization of ethylene

Block copolymers are produced by (i) polymerizing ethylene or propylene, or copolymerizing the same with another .alpha.-olefin of 2 to 7 carbon atoms in the presence of a Ziegler-type catalyst, and (ii) copolymerizing the resulting polymer or copolymer with a radical-polymerizable vinyl compound (e.g., methyl methacrylate) in the presence of an organic sulfoxide.

Process for producing block copolymers

Block copolymers of (i) a polymer of ethylene or propylene, or copolymer of ethylene or propylene with another .alpha.-olefin and (ii) a polymer of an acrylic ester or a methacrylic ester are formed by polymerizing (i) in the presence of a titanium halide and an organic aluminum compound, and then adding in order (a), (b) and (c) to copolymerize a product so obtained with (a) an acrylic ester or a methacrylic ester, in the presence of (b) an organic phosphorus compound or tertiary amine and (c) a benzyl halide, a ring-alkylated benzyl halide, a benzyl halide in which a methylene hydrogen is replaced with an alkyl or aryl group, or an alkyl halide.

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Chiba, Japan

Satoshi Asahi