Abstract: A leak inspection device includes an inspection mechanism that executes a first inspection process for compressing the insides of a first inspection chamber and a reference chamber, and inspecting the first inspection chamber for a pressure leak based on a differential pressure therebetween, and a second inspection process for compressing the insides of a second inspection chamber and the reference chamber, and inspecting the second inspection chamber for a pressure leak based on a differential pressure therebetween, a first pre-compression valve that opens and closes a first pre-compression path, and a control device that opens, during the execution of the first inspection process, the first pre-compression valve to pre-compress the second inspection chamber, and causes, in a state where the inside of the second inspection chamber is pre-compressed, the inspection mechanism to execute the second inspection process.

Abstract: A leak inspection device includes an inspection mechanism that executes a first inspection process for compressing the insides of a first inspection chamber and a reference chamber, and inspecting the first inspection chamber for a pressure leak based on a differential pressure therebetween, and a second inspection process for compressing the insides of a second inspection chamber and the reference chamber, and inspecting the second inspection chamber for a pressure leak based on a differential pressure therebetween, a first pre-compression valve that opens and closes a first pre-compression path, and a control device that opens, during the execution of the first inspection process, the first pre-compression valve to pre-compress the second inspection chamber, and causes, in a state where the inside of the second inspection chamber is pre-compressed, the inspection mechanism to execute the second inspection process.

Abstract: In a leak test method, a crank angle is set to a specific phase. When a crankshaft is positioned in the specific phase, an intake or exhaust valve of each cylinder including a combustion chamber having an inner volume that has become larger than an average value of inner volumes of combustion chambers of all the cylinders is open. When the crankshaft is at the set crank angle, a fluid for leak test is injected through intake and exhaust ports where the intake and the exhaust valves are disposed and that communicate with the combustion chambers, and through an engine opening other than the intake and the exhaust ports, with an opening of the engine other than the intake and exhaust ports and the engine opening to which the fluid is supplied in the leak test sealed. After fluid injection is completed, a pressure in the engine is measured.

Abstract: In a leak test method, a crank angle is set to a specific phase. When a crankshaft is positioned in the specific phase, an intake or exhaust valve of each cylinder including a combustion chamber having an inner volume that has become larger than an average value of inner volumes of combustion chambers of all the cylinders is open. When the crankshaft is at the set crank angle, a fluid for leak test is injected through intake and exhaust ports where the intake and the exhaust valves are disposed and that communicate with the combustion chambers, and through an engine opening other than the intake and the exhaust ports, with an opening of the engine other than the intake and exhaust ports and the engine opening to which the fluid is supplied in the leak test sealed. After fluid injection is completed, a pressure in the engine is measured.

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 catalyst for use in polymerization of olefins which comprises a carrier mainly composed of a magnesium compound precipitated from a solution and a catalytic component supported on the carrier and selected from titanium halides, vanadyl halides and vanadium halides is described. The catalyst is obtained by a process which comprises: (A) mixing (a) at least one magnesium compound with (c) a saturated or unsaturated monohydric or polyhydric alcohol for reaction in dissolved state in the presence of (b) carbon dioxide in an inert hydrocarbon solvent to obtain component (A); (B) subjecting the component (A) to mixing and reaction with (d) a titanium and/or a vanadyl halide and/or a vanadium halide of the general formula, VX.sub.r (OR.sup.8).sub.4-r, and also with (e) at least one boron compound, Si compound and/or Siloxane compound thereby obtaining solid product (I); (C) reacting the solid product (I) with (f) a cyclic ether with or without R.sup.

Abstract: A highly active catalyst for olefin polymerization, which is resistant to catalyst poisons contained in olefins as polymerization raw material and according to which the percentage of amorphous polymer formed is small, is provided, which catalyst is obtained byreacting a reaction product (I) of an organoaluminum compound with an electron donor, with TiCl.sub.4,further reacting the resulting solid product (II) with an electron donor and an electron acceptor,mixing the resulting solid product (III) with an organoaluminum compound in an inert solvent,keeping the resulting catalyst dispersion at 0.degree. to 70.degree. C., andhaving a small amount of an .alpha.-olefin and an extremely small amount of carbonyl sulfide slowly absorbed in the dispersion kept as above, to thereby subject the dispersion to a preliminary polymerization.