Abstract: Provided is a method for the preparation of polycrystalline silicon in which, in conducting preparation of polycrystalline silicon by the Siemens method or by the monosilane method, no outer heating means is necessitated for the core member (seed rod), onto which polycrystalline silicon is deposited, from the initial stage of heating, the deposition rate is high and the core member seed rod can be used repeatedly. The method for deposition of high-purity polycrystalline silicon, at a high temperature, onto a white-heated seed rod in a closed reaction furnace by pyrolysis or hydrogen reduction of a starting silane gas supplied thereto, is characterized in that the seed rod is a member made from an alloy having a recrystallization temperature of 1200° C. or higher. It is preferable that the alloy member is of an alloy of Re—W, W—Ta, Zr—Nb, titanium-zirconium, or a carbon-added molybdenum (TZM) in the form of a wire member having a diameter of at least 0.

Abstract: Films of a plastic resin such as a polyester film for packaging use can be imparted with improved gas barrier property or decreased permeability to gases such as water vapor and oxygen without decreasing pliability or flexibility and without degradation of the appearance and transparency so as to be useful as a packaging film for products having sensitivity to those gases. According to the invention, a plastic film is provided on at least one surface with a vapor-deposited layer of amorphous silicon of 10 to 200 nm thickness. The vapor deposition process is carried out preferably by a chemical vapor deposition method using silane and hydrogen as the reactant gases The gas permeability can be further decreased by a heat treatment of the amorphous silicon layer at 70 to 140° C.

Abstract: [Problems]Provided is a method for the preparation of polycrystalline silicon in which, in conducting preparation of polycrystalline silicon by the Siemens method or by the monosilane method, no outer heating means is necessitated for the core member (seed rod), onto which polycrystalline silicon is deposited, from the initial stage of heating, the deposition rate is high and the core member seed rod can be used repeatedly. [Means for solution]The method for deposition of high-purity polycrystalline silicon, at a high temperature, onto a white-heated seed rod in a closed reaction furnace by pyrolysis or hydrogen reduction of a starting silane gas supplied thereto, is characterized in that the seed rod is a member made from an alloy having a recrystallization temperature of 1200° C. or higher. It is preferable that the alloy member is of an alloy of Re-W, W-Ta, Zr-Nb, titanium-zirconium, or a carbon-added molybdenum (TZM) in the form of a wire member having a diameter of at least 0.

Abstract: A polycrystalline silicon material for solar power generation is polycrystalline silicon obtained by supplying a raw material silane gas to a red-hot silicon seed rod in a sealed reactor at high temperature to thereby thermally decompose or hydrogen-reduce the raw material silane gas. The polycrystalline silicon has a p-type or n-type conductivity, a resistivity of 3 to 500 ?cm, and a lifetime of 2 to 500 ?sec and is used for manufacturing a silicon wafer for solar power generation.

Abstract: Different from conventional so-called mix-type film capacitors involving several disadvantages, in which the dielectric layers consist of a combination of a dielectric plastic resin film and an insulating paper sheet, the invention provides an all-film oil-impregnated capacitor in which the dielectric layers consist only of a plastic resin film such as a biaxially oriented polypropylene resin film (OPP film) suitable for use in microwave ovens. The all-film capacitor of the invention can be obtained and has satisfactory properties only when prepared by using specified materials including the OPP film, aluminum foil and capacitor oil and under specified conditions relative to the dielectric tangent values and dielectric capacity values before and after impregnation with a capacitor oil as well as the conditions in the step of oil impregnation.

Abstract: Different from conventional so-called mix-type film capacitors involving several disadvantages, in which the dielectric layers consist of a combination of a dielectric plastic resin film and an insulating paper sheet, the invention provides an all-film oil-impregnated capacitor in which the dielectric layers consist only of a plastic resin film such as a biaxially oriented polypropylene resin film (OPP film) suitable for use in microwave ovens. The all-film capacitor of the invention can be obtained and has satisfactory properties only when prepared by using specified materials including the OPP film, aluminum foil and capacitor oil and under specified conditions relative to the dielectric tangent values and dielectric capacity values before and after impregnation with a capacitor oil as well as the conditions in the step of oil impregnation.

Abstract: Disclosed is an efficient and inexpensive method for the purification of low-grade silicon such as metallurgical-grade metallic silicon to give solar cell-grade silicon. The method comprises: (a) melting the starting low-grade silicon in a melting crucible; (b) bringing an end of an elongated linear fiber compact body of a refractory material, e.g., bundles of carbon fibers, into contact with the molten silicon in the crucible so that the molten silicon infiltrates and migrates through the fiber compact body by the capillary phenomenon to reach the other end of the fiber compact body held at a lower level than the first end; and (c) receiving the effluent of molten silicon discharged out of the second end of the fiber compact body in a receptacle crucible. The atmospheric gas is preferably a gaseous mixture of an inert gas, e.g., argon, and a small amount of a reactive gas, e.g.

Abstract: A metallic touch roller for use in an apparatus for manufacturing film rolls. The outer surface of the touch roller has a matte-finish with a plurality of symmetrically formed spiral grooves extending over the length of the roller. A mean surface roughness of the matte-finished surface may be from 0.5 to 2.0 .mu.m and, preferably, from 1.0 to 1.3 .mu.m.