Abstract: A main object is to provide a biaxially stretched polypropylene film for capacitors that has high voltage resistance at high temperatures and excellent dielectric breakdown properties and that can be formed into an ultrathin film. Furthermore, a capacitor obtained by using the biaxially stretched polypropylene film for capacitors described above is provided. The biaxially stretched polypropylene film for capacitors, includes a polypropylene resin, and the film has a spacing value of (040) face of ?-crystal measured by X-ray diffraction of 0.525 to 0.530 nm.

Abstract: A main object is to provide a biaxially stretched polypropylene film for capacitors that has high voltage resistance at high temperatures and excellent dielectric breakdown properties and that can be formed into an ultrathin film. Furthermore, a capacitor obtained by using the biaxially stretched polypropylene film for capacitors described above is provided. The biaxially stretched polypropylene film for capacitors, includes a polypropylene resin, and the film has a spacing value of (040) face of ?-crystal measured by X-ray diffraction of 0.525 to 0.530 nm.

Abstract: A polypropylene/ethylene block copolymer, which has a poly(ethylene-co-propylene) segment content of 5 to 100 wt. %, excluding 100 wt. %, and a total ethylene content of 2 to 95 wt. %. (a) The block polymer comprises polypropylene segments and poly(ethylene-co-propylene) segments chemically bonded thereto, and (b) the polypropylene segments and the poly(ethylene-co-propylene) segments have been synthesized in the presence of an olefin polymerization catalyst comprising an organometallic compound and a solid catalyst component comprising either titanium and a halogen, or titanium, magnesium, and a halogen. The block copolymer has a weight-average molecular weight of 100,000 or higher, is suitable for producing general-purpose molded articles, and has an excellent balance among mechanical properties, impact resistance, thermal properties, transparency, moldability, and other properties.

Abstract: A polypropylene/ethylene block copolymer, which has a poly(ethylene-co-propylene) segment content of 5 to 100 wt. %, excluding 100 wt. %, and a total ethylene content of 2 to 95 wt. %. (a) The block polymer comprises polypropylene segments and poly(ethylene-co-propylene) segments chemically bonded thereto, and (b) the polypropylene segments and the poly(ethylene-co-propylene) segments have been synthesized in the presence of an olefin polymerization catalyst comprising an organometallic compound and a solid catalyst component comprising either titanium and a halogen, or titanium, magnesium, and a halogen. The block copolymer has a weight-average molecular weight of 100,000 or higher, is suitable for producing general-purpose molded articles, and has an excellent balance among mechanical properties, impact resistance, thermal properties, transparency, moldability, and other properties.

Abstract: A polypropylene/ethylene block copolymer, which has a poly(ethylene-co-propylene) segment content of 5 to 100 wt. %, excluding 100 wt. %, and a total ethylene content of 2 to 95 wt. %. (a) The block polymer comprises polypropylene segments and poly(ethylene-co-propylene) segments chemically bonded thereto, and (b) the polypropylene segments and the poly(ethylene-co-propylene) segments have been synthesized in the presence of an olefin polymerization catalyst comprising an organometallic compound and a solid catalyst component comprising either titanium and a halogen, or titanium, magnesium, and a halogen. The block copolymer has a weight-average molecular weight of 100,000 or higher, is suitable for producing general-purpose molded articles, and has an excellent balance among mechanical properties, impact resistance, thermal properties, transparency, moldability, and other properties.

Abstract: A process for preparing polypropylene-b-poly(ethylene-co-propylene) by the use of a tubular continuous polymerizer in the presence of an olefin-polymerizing catalyst comprising a solid catalyst component (1) composed of titanium and halogen; an organosilicon compound (2); and, if necessary, at least one electron-donating compound (3) selected from the group consisting of organosilicon compounds represented by the general formula: RnSi(OR′)4−n (wherein R and R′ are each independently a C1-C10 hydrocarbon group; and n is an integer of 1 to 3) and nitrogenous heterocyclic compounds, wherein the solid catalyst component (1) is preliminarily brought into contact with the organosilicon compound (2) in the presence of the electron-donating compound (3), and then a polypropylene segment is formed through polymerization, followed by formation of a poly(ethylene-co-propylene) segment at the end of the polypropylene segment through polymerization.

Abstract: A propylene-ethylene block copolymer composition is disclosed which comprises 0.01 to 10% by weight of an A-B type propylene-ethylene block copolymer (C) consisting essentially of a polypropylene segment (A) and an ethylene-propylene random copolymer segment (B), and 99.99 to 90% by weight of a propylene polymer (D), wherein the A-B type propylene-ethylene block copolymer (C) comprises 5 to 80% by weight of the ethylene-propylene random copolymer segment (B) having an ethylene content of 10 to 90% by weight and the propylene polymer (D) comprises 60 to 95% by weight of a homopolymer of propylene or a copolymer of propylene containing a copolymerizable monomer therewith (D1) and 40 to 5% by weight of an ethylene-propylene random copolymer (D2).

Abstract: A propylene-ethylene block copolymer composition is disclosed which comprises 0.

Abstract: A propylene-ethylene block copolymer composition is disclosed which comprises 0.01 to 10% by weight of an A-B type propylene-ethylene block copolymer (C) consisting essentially of a polypropylene segment (A) and an ethylene-propylene random copolymer segment (B), and 99.99 to 90% by weight of a propylene polymer (D), wherein the A-B type propylene-ethylene block copolymer (C) comprises 5 to 80% by weight of the ethylene-propylene random copolymer segment (B) having an ethylene content of 10 to 90% by weight and the propylene polymer (D) comprises 60 to 95% by weight of a homopolymer of propylene or a copolymer of propylene containing a copolymerizable monomer therewith (D1) and 40 to 5% by weight of an ethylene-propylene random copolymer (D2).

Abstract: A platelet metabolism suppressing blood compatible material has a supramolecular structure containing a plurality of cyclic compounds and a hydrophilic straight-chain polymer threading into cavities of the cyclic compounds. Both terminals of the polymer are respectively capped with biodegradable groups having bulks sufficient to prevent the dethreading of the cyclic compounds.

Abstract: A chemically bonded olefin block copolymer consists essentially of chemically bonded polypropylene and poly(ethylene-co-propylene). The block copolymer is obtained by a process of (1) introducing a Ziegler polymerization catalyst based on titanium and propylene to a first polymerization zone (a) and polymerizing the propylene in the polymerization zone (a) for a period of 0.01 to 0.130 seconds and withdrawing an effluent stream of polypropylene, catalyst, solvent and unreacted propylene therefrom; (2) introducing the effluent stream to a second polymerization zone (b) together with ethylene dissolved in a solvent and carrying out a polymerization reaction in the second polymerization zone (b) for a period of 0.01 to 0.130 seconds; and (3) recovering the block copolymer.

Abstract: A novel catalyst and solid catalyst component useful for preparing polyolefins having a broad molecular weight distribution and high stereoregularity.

Abstract: A solid catalyst component prepared under specific conditions by reacting with a reaction product which has been obtained by suspending diethoxymagnesium in an alkylbenzene and bringing the suspension into contact with titanium tetrachloride, phthaloyl dichloride at 80.degree.-125.degree. C.

Abstract: A solid catalyst component prepared by admixing and reacting, with a reaction product which has been obtained by suspending diethoxymagnesium in an alkylbenzene and bringing the suspension into contact with titanium tetrachloride in an amount less than 1 in terms of volume ratio to the alkylbenzene, a phthaloyl dichloride at a temperature within the range between 80.degree. C. and 125.degree. C., washing the resultant solid substance with an alkylbenzene, and reacting the solid substance in the presence of an alkylbenzene with titanium tetrachloride in an amount less than 1 in terms of volume ratio to the alkylbenzene as well as an olefin polymerization catalyst which comprises (A) the above specified solid catalyst component, (B) a silicon compound of the general formula: SiR.sub.m (OR').sub.

Abstract: A solid catalyst component for olefin polymerization catalysts prepared by suspending diethoxymagnesium (a) in an aromatic hydrocarbon (b) which is liquid at normal temperature and bringing the suspension into a first contact with titanium tetrachloride (c) to form a product and bringing it into a second contact with tianium tetrachloride (c) in such manner that a diester (d) of an aromatic dicarboxylic acid and calcium chloride (e) are allowed to coexist at any stage of the above suspending and/or contacts, the calcium chloride (e) being used in an amount of 1-2 grams per gram of the diethoxymagnesium (a). This solid catalyst component exhibits, when applied to the polymerization of olefins, a surprisingly enhanced polymerization activity per titanium atom and a high stereospecific performance and scarcely necessitates any deashing treatment, thus affording a great economical advantage.

Abstract: A solid catalyst component for olefin polymerization catalysts prepared by subjecting diethoxymagnesium (a), calcium chloride (b) and a silicon compound (c) of the general formula: Si(OR).sub.4 (wherein R is an alkyl or aryl group) together to a contact treatment in the presence of an organic solvent (d), suspending the treated composition in an aromatic hydrocarbon (e) which is liquid at normal temperature and bringing the suspension into a first contact with titanium tetrachloride (f) to form a product and bringing it to a second contact with titanium tetrachloride (f) in such manner that a diester (g) of an aromatic dicarboxylic acid is allowed to coexist at any stage of the above suspending and/or contacts with the exception of the contact treatment, the calcium chloride (b) being used in an amount of 1-2 g per gram of the diethoxymagnesium (a).

Abstract: A catalyst for the polymerization of olefins which exhibits a high catalytic activity and is capable of producing a stereoregular polymer in a high yield. The catalyst includes a catalyst component for the polymerization of olefins prepared by subjecting a solid composition obtained by a process comprising contacting dialkoxymagnesium, diester of aromatic dicarboxylic acid, aromatic hydrocarbon and titanium halide to a heat treatment in the presence or absence of a solvent; a silicon compound; and an organic aluminum compound.

Abstract: A solid catalyst component prepared by washing a solid substance, which has been obtained by reacting diethoxymagnesium (a) suspended in an alkylbenzene (b) with titanium tetrachloride (c) in an amount less than 1/2 of the alkylbenzene (b) in a ratio by volume and a phthalic diester (d) at a temperature within the range of 80.degree.-135.degree. C., with an alkylbenzene, and thereafter reacting the solid substance in a presence of an alkylbenzene (b) with titanium tetrachloride (c) in an amount less than 1/2 of the alkylbenzene (b) in a ratio by volume as well as an olefin polymerization catalyst comprising (A) the solid catalyst component specified above, (B) a silicon compound of the general formula:SiR.sub.m (OAlk).sub.

Abstract: A catalyst for the polymerization of olefins which comprises:(A) a solid catalyst component prepared by bringing a co-ground product of a substance (a) obtained by reacting magnesium with at least two molar proportion of an alkyl monohalide in the absence of a solvent but in the presence of iodine and a dialkyl phthalate (b) and optionally existing titanium tetrachloride (c) into contact with titanium tetrachloride in the presence or absence of an aromatic hydrocarbon and/or halohydrocarbon.(B) a 2,6-dialkyl- or 2,2,6,6-tetraalkyl-piperidine derivative, and(C) an organoaluminum compound selected from a trialkyl aluminum, a dialkylaluminum halide and an alkylaluminum dihalide, as well as the solid catalyst component (A) for the catalyst. This catalyst characterized by the use of the specific solid catalyst component exhibits a high polymerization activity combined with stereospecific performance over a prolonged polymerization time and is free from any problem of corrosion and odor in the resultant polymer.

Abstract: A catalyst for the polymerization of olefins which comprises:(1) a solid catalyst component,(2) a piperidine derivative and(3) an organoaluminum compound,characterized in that the solid catalyst component (A) has been prepared by mixing (a) a dialkoxymagnesium and (b) a diester of an aromatic dicarboxylic acid with (c) a halogenated hydrocarbon to form a suspension and thereafter adding the suspension to (d) a titanium tetrahalide to effect reaction, as well as the solid catalyst component and a process for preparing same. The catalyst maintains a high polymerization activity combined with stereospecific performance over a prolonged polymerization time and scarcely incurs any problem of corrosion and odor in the resultant polymer.