Abstract: A novel method for producing an olefinic resin porous material with no skin layer is provided. The method for producing an olefinic resin porous material disclosed herein includes the steps of preparing a single phase in which an olefinic resin, a hydrocarbon compound, and a polar compound are mixed one another, in a pressure-resistant container, introducing high pressure carbon dioxide into the pressure-resistant container, and releasing the pressure in the pressure-resistant container. The polar compound has a hydroxy group or a carbonyl group. Introducing the high pressure carbon dioxide is carried out such that the pressure in the pressure-resistant container reaches 6 MPa or higher.

Abstract: A polymer solution is created by mixing an olefin-based resin and a solvent in a pressure vessel. A high-pressure fluid of carbon dioxide is created. Temperature of the high-pressure fluid is adjusted. A mixed fluid is created by mixing the high-pressure fluid of which the temperature is adjusted and the polymer solution in the pressure vessel. Cooling of the mixed fluid causes phase separation of the mixed fluid to occur. After phase separation, pressure in the pressure vessel is released, and the solvent and the carbon dioxide vaporize. The vaporizing of the solvent and the carbon dioxide creates a porous medium of olefin-based resin.

Abstract: A novel method for producing an olefinic resin porous material is provided. The method for producing an olefinic resin porous material disclosed herein includes the steps of preparing a single phase in which an olefinic resin and a solvent are mixed each other, in a pressure-resistant container, introducing high pressure carbon dioxide into the pressure-resistant container, and releasing the pressure in the pressure-resistant container. In this method, introducing the high pressure carbon dioxide is carried out such that the pressure in the pressure-resistant container reaches 6 MPa or higher.

Abstract: A novel method for producing an olefinic resin porous material with no skin layer is provided. The method for producing an olefinic resin porous material disclosed herein includes the steps of preparing a single phase in which an olefinic resin, a hydrocarbon compound, and a polar compound are mixed one another, in a pressure-resistant container, introducing high pressure carbon dioxide into the pressure-resistant container, and releasing the pressure in the pressure-resistant container. The polar compound has a hydroxy group or a carbonyl group. Introducing the high pressure carbon dioxide is carried out such that the pressure in the pressure-resistant container reaches 6 MPa or higher.

Abstract: A method for preparing composite microspheres of a high-molecular material and a core substance includes the steps of: dissolving a high-molecular material and dispersing a core substance in a high pressure fluid containing a supercritical fluid and an entrainer, under a shear stress of 1 Pa or more; and spraying the resultant high pressure fluid containing the high-molecular material and the core substance into a poor solvent to cause rapid expansion. According to the method composite microspheres having a uniform size of several micrometers or less, and more preferably nanometer order (a size of 1 ?m or less) can be obtained.

Abstract: A method for producing high-molecular weight microspheres of the present invention includes the steps of dissolving or dispersing a high-molecular material in a high pressure fluid containing a supercritical fluid and an entrainer, and spraying the resultant high pressure fluid into a poor solvent to cause rapid expansion. According to the production method, high-molecular weight microspheres or coated microspheres whose average particle size can be controlled can be produced.

Abstract: A vacuum discharge device comprising an insulating envelop having metallic layers formed by a metallizing process respectively on the opposite ends thereof, electrodes disposed within the insulating envelop, and sealing members brazed respectively to the metallic layers. The insulating envelop is a hollow, cylindrical ceramic member having a substantially uniform wall thickness between each wavy inner ridges, or each crest of wavy ridges. The inner creeping length and outer creeping length of the insulating evelop are greater than the distance between the sealing members or between the metallic layers.

Abstract: A polymer slurry formed by polymerizing ethylene or propylene optionally with other olefin monomer copolymerizable therewith in a hydrocarbon solvent such as propylene, propane, butane, etc., is continuously or intermittently supplied to a filter having a filtering surface on which a slight quantity of polymer particles are retained. Most of the hydrocarbon solvent is recovered by passing through the filtering surface, and the polymer particles are overflown from the filter to recover as a wet cake. By the use of such a specific filter, the quantity of the solvent to be vaporized can be greatly reduced.

Abstract: A particulate polyolefin molding material is disclosed. The material is comprised of a particulate polyolefin particle having a bulk density of 0.45 g/cc or more and a mean particle size of 150 to 2,000.mu., and a layer comprising a compounding additive and a binder formed on the surface of the particle. The material can be used in producing molded articles without first forming the material into pellets as is conventionally done.

Abstract: In a process for producing a homopolymer or a copolymer of propylene comprising polymerizing propylene or copolymerizing propylene and at least one other unsaturated hydrocarbon monomer in liquid propylene using a catalyst system containing activated titanium trichloride (a) and an organoaluminum compound (b), the activated titanium trichloride (a) being prepared by reducing titanium tetrachloride with an organoaluminum compound followed by activation, to produce a polymer slurry; introducing the polymer slurry produced into the top of a counter-current washing tower; and washing the polymer slurry by counter-currently contacting the polymer slurry with liquid propylene introduced into the bottom of the washing tower, the improvement which comprises purifying the homopolymer or copolymer of propylene by feeding an epoxide in a molar amount of about 1 to about 15 times the molar amount of the total of activated titanium trichloride (a) and organoaluminum compound (b), to a part of said washing tower, thereby d

Abstract: Granules containing 60 wt. % or more filler, having such particle size distribution that 90 wt. % or more granular particles have a particle size of (1/3)d.sub.50.sup.b to 3d.sub.50.sup.b (d.sub.50.sup.b : mean particle size of the granules), and being produced by blending (a) 60 to 90 parts by weight of a filler having a mean particle size of 0.05 to 100.mu., (b) 5 to 35 parts by weight of crystalline polyolefin powder having a mean particle size (d.sub.50.sup.a) of 150 to 1,000.mu. and having such particle size distribution that 90 wt. % or more particles thereof have a particle size of (1/2)d.sub.50.sup.a to 2d.sub.50.sup.a, (c) 5 to 35 parts by weight of a binder having a melting point lower than that of said crystalline polyolefin powder by a least 10.degree.C., and optionally, (d) a compounding additive, at a temperature lower than the melting point of the crystalline polyolefin powder and higher than the melting point of the binder, is disclosed.

Abstract: In a process for producing polypropylene comprising polymerizing propylene in the presence of hydrogen and a catalyst system comprising (A) titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound and reacting the reduced solid with an ether represented by the formula:R.sup.1 --O--R.sup.2wherein R.sup.1 and R.sup.2 are defined hereinbefore, and a halogen compound selected from the group consisting of (i) halogen or interhalogen compounds of the formula, X.sup.1 X.sup.2.sub.a (wherein X.sup.1, X.sup.2 and a are defined hereinbefore), (ii) titanium halides, and (iii) organic halogen compounds, simultaneously or successively and (B) an organoaluminum compound, the improvement which comprises supplying ethylene together with propylene to the polymerization system such that the ethylene concentration in the vapor phase of the system based on the total amount of propylene, ethylene and hydrogen in the vapor phase of the system is 0.15 to 1.

Abstract: In polymerizing an olefin, for example, in a polymerization reactor with a reflux condenser, a gas mixture withdrawn from the polymerization reactor is first washed before it reaches the heat transfer surface of the reflux condenser to remove active catalyst particles and polymer particles entrained therein and then condensed to obtain a condensed liquid, and the condensed liquid is returned to the polymerization reactor whereby the heat generated in the polymerization reactor is efficiently removed without causing any clogging of pipes, etc.

Abstract: In a process for producing propylene copolymer containing about 80 to 99 mol % propylene and about 1 to 20 mol % ethylene and/or an .alpha.-olefin having 4 to 18 carbon atoms using a Ziegler-Natta catalyst, the improvement which comprises said Ziegler-Natta catalyst comprising:(A) titanium trichloride prepared by reducing titanium tetrachloride with an organoaluminum compound and activating the product; and(B) an organoaluminum compound;with the molar ratio of (B)/(A) being about 20 to 100.

Abstract: In a process for producing polypropylene comprising polymerizing propylene in the presence of hydrogen and a catalyst system comprising (A) titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound and reacting the reduced solid with an ether represented by the formula:R.sup.1 -O-R.sup.2wherein R.sup.1 and R.sup.2 are defined hereinbefore, and a halogen compound selected from the group consisting of (i) halogen or interhalogen compounds of the formula, X.sup.1 X.sup.2.sub.a (wherein X.sup.1, X.sup.2 and a are defined hereinbefore), (ii) titanium halides, and (iii) organic halogen compounds, simultaneously or successively and (B) an organoaluminum compound, the improvement which comprises supplying ethylene together with propylene to the polymerization system such that the ethylene concentration in the vapor phase of the system based on the total amount of propylene, ethylene and hydrogen in the vapor phase of the system is 0.15 to 1.

Abstract: A molded product of polypropylene having an isotactic pentad fraction of the boiling heptane insoluble portion of at least about 0.955 and a boiling heptane solubles content of about 2.0 to 9.0% by weight. The molded products include a stretched film, insulating materials for electrical equipment, etc.

Abstract: A process for producing a propylene polymer or copolymer which comprises polymerizing (a) propylene or (b) a mixture of propylene and another unsaturated hydrocarbon monomer in liquid propylene in the presence of a catalyst system of(A) a specified titanium trichloride composition obtained by reducing titanium tetrachloride with an organoaluminum compound and activating the product;(B) an organoaluminum compound having the general formulaR.sub.2 AlXwherein R represents an alkyl group or an aralkyl group, each containing up to 18 carbon atoms, and X represents a halogen atom; and(C) an unsaturated carboxylic acid ester; while adjusting the amount of the polymer produced to at least 8,000 g per gram of the titanium trichloride composition.

Abstract: A slurry containing polymer particles having an average particle diameter of 0.1 to 1 mm suspended therein is discharged smoothly from a discharge valve without valve clogging by operating the valve such that the degree of valve opening is set within a range II for a valve operating time t.sub.1 and within a range III for a valve operating time t.sub.2 ; the time t.sub.1 being from 5 to 60 seconds, the time t.sub.2 being from 1 to 10 seconds, the range II being a range of valve openings at which the valve is gradually clogged with the polymer particles discharged, and the range III being a range of valve openings at which the valve permits continuous discharge without clogging.

Abstract: In a process for the recovery of an atactic polymer which comprises heating liquid propylene containing the dissolved atactic polymer at a gauge pressure of 13 to 40 kg/cm.sup.2 in a vaporizer to vaporize the propylene, and separating the atactic polymer from the vaporized propylene thereby recovering the polymer in a molten state, the improvement comprising maintaining the vaporization temperature of propylene at 45.degree. C. to 90.degree. C. and the temperature of a heating medium for the vaporizer at 60.degree. C. to 150.degree. C. According to this process, a long run can be used in the recovery of the atactic polymer.

Abstract: A molded product of polypropylene having an isotactic pentad fraction of the boiling heptane insoluble portion of at least about 0.955 and a boiling heptane solubles content of about 2.0 to 9.0% by weight. The molded products include a stretched film, insulating materials for electrical equipment, etc.