Abstract: A polydisperse propylene polymer characterized by being produced by polymerizing a propylene monomer or a mixed monomer of propylene and other olefin(s) by a multistage polymerization wherein the polymerization conditions are stepwise changed in the presence of a supported metallocene catalyst having a transition metal compound and an aluminoxane or a reaction product thereof supported on a finely particulate support, and an organoaluminum compound as a scavenger, and by having a ratio of a weight-average molecular weight to a number-average molecular weight (Mw/Mn) of 4.0 or higher, a melting point (Tm) of 165° C. or lower and a difference between the melting point (Tm) and a heat distortion temperature (HDT) of 30° C. or less.

Abstract: The invention relates to a polyolefin-based resin composition that is in an amount of 100 wt % in total. This composition includes (a) 60-66 wt % of a crystalline propylene-ethylene block copolymer, (b) 12-20 wt % of an ethylene-propylene copolymer rubber, and (c) 18-25 wt % of an inorganic filler. The block copolymer contains a first segment of a homopolymer of propylene and a second segment of a copolymer of propylene and ethylene, and has an isotactic pentad tacticity of at least 0.96. The ratio of the weight average molecular weight of the block copolymer to the number average molecular weight thereof is not greater than 6. The copolymer rubber contains therein 50-60 wt % of ethylene, and has a Mooney viscosity of from 45 to 55 at 125° C. The inorganic filler is one selected from the group consisting of a talc, a first combination of the talc and a glass fiber, and a second combination of the talc and a whisker. The talc has an average particle diameter of not greater than 2 &mgr;m.

Abstract: Disclosed is a process for producing olefin polymers or copolymers which can freely regulates the molecular weight of the polymers or copolymers as well as novel olefin polymers or copolymers excellent in rigidity, heat-resisting property and transparency, moldings and compositions thereof which find a wide variety of applications in versatile industrial parts including containers, films, sheets, filaments or fibers, featured by (1) a process for producing olefin polymers or copolymers by the aid of a catalyst comprised predominantly of the compounds: (A) a transition metal compound of the formula: Q(C5H4−mR1m)(C5H4−nR2n)MXY, (B) an aluminoxane, (C) a fine particulate carrier, and (D) an organoaluminum compound; (2) olefin polymers or copolymers characterized by (a) a specific ratio of isotactic pentad, (b) 2,1- and 1.

Abstract: The present invention provides propylene/ethylene random copolymers characterized in that: an ethylene content (Ew) is 0.1-10 wt %, a relationship between an isolated ethylene content (E1) and the ethylene content (Ew) is represented by the following equation E1>0.85−0.01 Ew 2,1- and 1,3-propylene units present in a polymer chain are 0-1 mol %, a weight average molecular weight (Mw) is in the range of 40,000-1,000,000, and a ratio (Mw/Mn) of the weight average molecular weight (Mw) to a number average molecular weight(Mn) is in the range of 1.5-3.8. The copolymers are suitable for a base resin for a molding material for the production of a wide variety of molded articles which are high in randomness and excellent in stiffness, heat resistance and transparency.

Abstract: Disclosed is a polypropylene composition excellent in balance of low temperature impact-strength, rigidity, heat resistance and transparency, which is featured by comprising 20-95% by weight of a polypropylene defined in the following [I] and 5-80% by weight of a propylene-&agr;-olefin copolymer defined in the following [II]: [I] a polypropylene featured by having: (1) a ratio of isotactic pentad (mmmm) of 0.900-0.949, (2) the 2,1- and 1,3-propylene units in the polymer chain in the amount of 0-1 mole %, (3) a weight average molecular weight (Mw) of 40,000-1,000,000, (4) a ratio of a weight average molecular weight (Mw) to a number average molecular weight (Mn), i.e. (Mw)/(Mn) of 1.5-3.8, and (5) in case of elevating the temperature of o-dichlorobenzene continuously or stepwise up to given temperatures to measure the amount of eluted polypropylene at each temperature, the position of a main elution peak is 95-110° C.

Abstract: The invention relates to a polyolefin-based resin composition that is in an amount of 100 wt % in total. This composition includes (a) 60-66 wt % of a crystalline propylene-ethylene block copolymer, (b) 12-20 wt % of an ethylene-propylene copolymer rubber, and (c) 18-25 wt % of an inorganic filler. The block copolymer contains a first segment of a homopolymer of propylene and a second segment of a copolymer of propylene and ethylene, and has an isotactic pentad tacticity of at least 0.96. The ratio of the weight average molecular weight of the block copolymer to the number average molecular weight thereof is not greater than 6. The copolymer rubber contains therein 50-60 wt % of ethylene, and has a Mooney viscosity of from 45 to 55 at 125° C. The inorganic filler is one selected from the group consisting of a talc, a first combination of the talc and a glass fiber, and a second combination of the talc and a whisker. The talc has an average particle diameter of not greater than 2 &mgr;m.

Abstract: A rotary body of hard material with a plastic supporter and a method of manufacturing therefor, which essentially comprises a coating film coated with the rotary body and removed after molding so as to make a clearance between the rotary body and the supporter, so that rotation of the rotary body may be allowed smoothly. The method of this invention defines steps of molding, coating of film and removing of the film so as to obtain rotation of rotary body relative to the plastic supporter.

Abstract: A diaphragm for an electroacoustic transducer comprising stratiform mineral of layers into which a hardener or an agent for facilitating hardening is adsorbed between the layers, thermosetting resin monomer, and carbonfibers which constitute a composite material which is formed under heat and pressure. The diaphragm is increased in rigidity which is required as physical properties therefor and is easy in forming.

Abstract: A method of and apparatus for controlling automatic soldering system in which respective units of the automatic soldering system are controlled preparatorily to reduce the waiting time until main driving to zero. In the soldering driving time, the temperature of the work itself is precisely controlled to the predetermined value by means of directly measuring the temperature of the work and controlling the preheater to bring the soldering characteristic in the next soldering step into the most optimal value in compliance with the size and the like of the work to be soldered.