Abstract: A method for producing a polyolefin is disclosed which comprises polymerizing an .alpha.-olefin in the presence of a catalyst composition comprising (A) a solid catalyst component prepared by contacting (a) a solid component comprising a magnesium alkoxide and/or a magnesium salt of a fatty acid supported on an inorganic oxide composed of at least one member selected from the group consisting of oxides of elements belonging to Groups II, III and IV of the periodic table and/or a composite inorganic oxide containing at least one member selected from the group consisting of oxides of elements belonging to Groups II, III and IV of the periodic table, the inorganic oxide or composite inorganic oxide having a surface hydroxide concentration of 3 .mu.mol/m.sup.2 or less, (b) an electron donating compound and (c) a titanium halide, (B) an organic metal compound, and (C) an electron donating compound.

Abstract: A so-called Ziegler catalyst composed of a titanium halide-containing solid ingredient and an organoaluminum compound for the polymerization of olefins can be imparted with greatly improved storage stability by first subjecting the catalytic composition to a pre polymerization treatment and then to a contacting treatment with carbon dioxide and/or carbon monoxide. The catalytic activity is almost unchanged even after storage of the stabilized catalyst for 90 days or longer in nitrogen gas. The stabilized catalyst can also be used advantageously in a continuous-process polymerization of propylene by continuously introducing the monomer carrying the catalyst owing to absence of blocking of the pipe line with the polymer formed in-line.

Abstract: A microwave plasma generating apparatus radiates a microwave to a source gas to produce a plasma. A plurality of spaced fins are disposed in a path of travel of the microwave, from the microwave guide to an area of origin of the plasma within the plasma generating chamber to lie in a direction perpendicular to the direction of an electric field of the microwave, for the purpose of locking the position at which the plasma has been produced.

Abstract: A process for preparing a granular polyarylene sulfide having a high molecular weight is a one-stage polycondensation process which involves subjecting a dihalogen aromatic compound to polycondensation with a source of sulfur in the presence of a polymerization aid in an organic polar solvent and setting the temperature for polycondensation to a range from 220.degree. C. to 248.degree. C. for a predetermined period of time prior to completion of polycondensation up to completion of polycondensation. The resulting granular polyarylene sulfide is suitable for molding or forming into sheets, films, fibers and so on, causes less burrs when subjected to injection molding, has a high molecular weight sufficient to create the property of forming a gel, and is easy to handle.

Abstract: A polyarylene sulfide has an inherent viscosity [.eta..sub.i n h ] of 0.1 to 0.5 dl/g, a weight-average molecular weight of 1.times.10.sup.4 to 2.times.10.sup.5 ; a ratio of the inherent viscosity [.eta..sub.i n h ] to a calculated viscosity [.eta.].sub.calc ([.eta..sub.i n h /[.eta.].sub.calc) of 0.4/1 to 0.8/1; and a degree of whiteness of 50 or higher when measured in accordance with whiteness testing procedures (JIS P8123). The polyarylene sulfide is prepared by reaction by contacting at least one member of a metallic sulfide (A) selected from an alkali metal sulfide and an alkali metal hydrosulfide with a dihalogen aromatic compound (B) and an aromatic compound (C) having three or more than three functional groups in a polar solvent in a molar ratio of the dihalogen aromatic compound (B) to the metallic sulfide (A) [(B)/(A)] ranging from 1.035/1 to 1.300/1 and in a molar ratio of the aromatic compound (C) to the dihalogen aromatic compound (B) [(C)/(B)] ranging from 0.003/1 to 0.05/1.

Abstract: The polypropylene-based resin composition of the invention consists basically of (a) a polypropylene resin or a block copolymer of propylene and ethylene of specified ethylene content specified in terms of the melt index and the isotacticity relative to the isotactic pentad of the propylene moiety and (b) a talc powder specified in terms of the average particle diameter and the average aspect ratio of particles. The resin composition has good blow-moldability and is capable of giving molded articles having excellent mechanical strengths and dimensional accuracy to be useful, for example, as a material of automobile bumper beams.

Abstract: A glass fiber-reinforced synthetic resin composition is proposed which is particularly suitable as a molding material of chassis of electric and electronic instruments to satisfy the various requirements in this particular application. The resin composition comprises: (A) 100 parts by weight of a copolymeric resin of styrene and maleic anhydride or a derivative thereof, of which the molar fraction of the moiety of maleic anhydride or a derivative thereof is in the range from 3 to 20%; (B) from 1 to 30 parts by weight of a styrene-based thermoplastic elastomer, of which the weight fraction of the moiety of styrene is in the range from 5 to 50%; (C) from 5 to 80 parts by weight of glass fibers, (D) from 5 to 30 parts by weight of a bromine-containing organic compound as a flame retardant; and (E) from 2 to 15 parts by weight of antimony trioxide.

Abstract: The styrene-based polymer of the invention, which is excellent in the impact strength, rigidity and heat resistance as well as high-speed moldability, is characterized by a specified weight-average molecular weight and a specified relatively low content of a moiety derived from a polyfunctional vinyl compound, e.g., divinyl benzene. The polymer is also characterized by the behavior of kinematic viscosity. Such a styrene-based polymer can be prepared by the radical polymerization reaction of styrene monomer with admixture of a limited amounts of a polyfunctional vinyl compound and a polymerization initiator.

Abstract: The present invention is directed to a polyolefin type resin laminate that comprises a base layer made of a polyolefin type resin consisting mainly of butene-1 type polymer in which the content of other .alpha.-olefin unit of 15 mol % or below, the intrinsic viscosity [.eta.] is 1.2 to 4.0 dl/g, the ratio Mw/Mn of the weight-average molecular weight [Mw] to the number-average molecular weight [Mn] is from 2 to 10, and the haze is 50% or below, and layers each provided on each of the opposite surfaces of said base layer and made of a polyolefin type resin having a melt index [MI] of 0.1 to 30 g/10 min, the haze of each of the latter layers being up to that of said base layer, characterized in that the haze of said laminate is 3% or below, the strain recovery rate is 90% or over and the ratio of the tear strength in the M. D. to the tear strngth in the T. D. is from 0.25 to 4.

Abstract: The bis(hydroxyphenyl) sulfides mixture prepared according to the inventive method is advantageous in respect of the increased proportion of 4-mercaptophenol relative to less useful 2-mercaptophenol in the product obtained by the reductive decomposition of the mixture. The inventive method is characterized by performing the reaction of phenol and sulfur chloride in a specific solvent which is an ethylene glycol monoalkyl ether compound such as ethylene glycol monomethyl ether, triethylene glycol monoethyl ether and the like.