Abstract: A pneumatic tire includes a tread portion, a pair of sidewall portions, a first ply, and a discontinuous second ply composed of a pair of ply pieces. The first ply has a central portion and a pair of first side portions extending from both ends of the central portion to the inner side in the tire radial direction. Each of the ply pieces has an inner end portion disposed on the outer side in the tire radial direction of the central portion and a second side portion extending from the inner end portion to the inner side in the tire radial direction. The first ply is provided with a plurality of ventilation holes, and the density of the ventilation holes in the central portion is higher than the density of the ventilation holes in the pair of first side portions.

Abstract: A forming device forms a green tire including a discontinuous carcass ply composed of a pair of ply pieces. The forming device includes one servicer that sends out a strip-shaped first sheet for forming a plurality of the ply pieces, a drum around which the first sheet from the servicer is wound, a first cutting portion that cuts the first sheet to separate one of the ply pieces, a moving mechanism that relatively moves the servicer and the drum in the axial direction of the drum, and a control unit that controls the moving mechanism.

Abstract: A thermally conductive resin molded article having a resin and a thermally conductive filler is provided. The thermally conductive filler is oriented substantially in the thickness direction of the thermally conductive resin molded article. The volumetric filling factor of the thermally conductive filler in the thermally conductive resin molded article is 20-80% by volume. Weld lines in the resin are formed substantially in the thickness direction of the thermally conductive resin molded article. An oil component is included in the thermally conductive resin molded article.

Abstract: A thermally conductive resin molded article having a resin and a thermally conductive filler is provided. The thermally conductive filler is oriented substantially in the thickness direction of the thermally conductive resin molded article. The volumetric filling factor of the thermally conductive filler in the thermally conductive resin molded article is 20-80% by volume. Weld lines in the resin are formed substantially in the thickness direction of the thermally conductive resin molded article. An oil component is included in the thermally conductive resin molded article.

Abstract: A thermally conductive resin molded article having a resin and a thermally conductive filler is provided. The thermally conductive filler is oriented substantially in the thickness direction of the thermally conductive resin molded article. The volumetric filling factor of the thermally conductive filler in the thermally conductive resin molded article is 20-80% by volume. Weld lines in the resin are formed substantially in the thickness direction of the thermally conductive resin molded article. An oil component is included in the thermally conductive resin molded article.

Abstract: The present invention provides an optically clear adhesive sheet capable of reducing peeling after bonding due to causes such as outgassing and having excellent environment resistance, using a polyurethane that has excellent flexibility and is capable of giving a thick film. The optically clear adhesive sheet contains a polyurethane, the polyurethane being a cured product of a polyurethane composition containing a polyol component and a polyisocyanate component, the polyisocyanate component including a hydrophilic polyisocyanate, the optically clear adhesive sheet having a moisture content of 400 ppm or lower as measured by a Karl Fischer method.

Abstract: A thermally conductive resin molded article having a resin and a thermally conductive filler is provided. The thermally conductive filler is oriented substantially in the thickness direction of the thermally conductive resin molded article. The volumetric filling factor of the thermally conductive filler in the thermally conductive resin molded article is 20-80% by volume. Weld lines in the resin are formed substantially in the thickness direction of the thermally conductive resin molded article. An oil component is included in the thermally conductive resin molded article.

Abstract: A slide member has a sliding surface made of ceramic and a has surface roughness of not more than 1.0 .mu.m in center line average roughness Ra. The ceramics includes a silicon nitride sintered body which contains crystal grains having a linear density of at least 35 per 30 .mu.m in length with a boundary phase volume ratio of not more than 15 volume %, and which contains pores of not more than 20 .mu.m in maximum diameter in a content of not more than 3%. In a method of manufacturing the slide member, it is possible to ensure smoothness of the sliding surface by grinding the sliding surface and thereafter heating the ceramic in an either an inert gas or atmospheric air. A slide member that can be used under severe sliding conditions of high-speed sliding or the like and that has excellent wear resistance is obtained.

Abstract: A composite bearing structure that has a high rotational accuracy and that can withstand high-speed rotation comprises first bearing means, second bearing means, third bearing means and fourth bearing means. The first bearing means supports a radial impact force which is applied to a rotator during rotation, and is formed by an inner ring (1) and an outer ring (2) consisting of silicon nitride ceramics sintered bodies. The second bearing means supports an axial load which is applied to the rotator while maintaining a prescribed clearance with the rotator, and is formed by a magnetic bearing body of two permanent magnets (12) and (13) which are thrust-directionally opposed to each other. The third bearing means maintains the radial rotational accuracy of the rotator, and is formed by a radial dynamic pressure producing groove (5) which is formed in a cylindrical surface of the inner ring (1).

Abstract: Discloses a silicon nitride based sintered body composed only of uniform, fine crystal grains, and improved in both strength and fracture toughness in the middle and low temperature ranges. A crystalline silicon nitride powder composed of crystal grains whose longer-axis diameter is not more than 200 nm or an amorphous silicon nitride powder is used as material powder. The silicon nitride powder is sintered at a temperature of 1200.degree. C. to 1400.degree. C. or sintered with a product of sintering temperature (.degree. C.) and sintering time (sec) below 600000 (.degree. C..multidot.sec) at a temperature of 1400.degree. C. to 1900.degree. C. Thus, a silicon nitride based sintered body in which the longer-axis diameter of silicon nitride and/or sialon crystals is not more than 200 nm is obtained.

Abstract: A vacuum vessel is provided in which the majority of a vessel wall including an annular wall portion (1) and a plate-wall portion (2) is formed of ceramic material such as silicon nitride, for example. To bond the plural wall members together, bonding faces having a surface flatness of not more than 1 .mu.m are prepared thereon, and then a ceramic powder bonding substance with an average particle diameter of not more than 1 .mu.m is interposed between adjacent bonding faces and subjected to heating. Because the generation of gas, such as hydrogen, from the wall of the ceramic vessel is reduced, extremely high vacuum can be generated and maintained in the interior of the vacuum vessel. Also, because the wall of the vacuum vessel has a high permeability with respect to a magnetic field and an electric field, the vacuum vessel can be used as a vessel in a particle accelerator that allows the high precision control of charged particles therein by means of an electromagnetic field.

Abstract: A slide member has a sliding surface made of ceramic and has a surface roughness of not more than 1.0 .mu.m in center line average roughness Ra. ceramic includes a silicon nitride sintered body, which contains crystal grains having a linear density of at least 35 per 30 .mu.m in length with a boundary phase volume ratio of not more than 15 volume %, and which contains pores of not more than 20 .mu.m in maximum diameter in a content of not more than 3%. In a method of manufacturing the slide member, it is possible to ensure smoothness of the sliding surface by grinding the sliding surface and thereafter heating the ceramic in either inert gas or an atmospheric air. A slide member that can be used under severe sliding conditions of high-speed sliding or the like and that has excellent wear resistance is obtained.

Abstract: A silicon nitride composite sintered which comprises crystal grains of silicon nitride and/or sialon having an average minor axis length of 0.05 to 3 .mu.m and an aspect ratio of 10 or less and foreign particles dispersed in the crystal grains and/or the grain boundary phase, said particles having a thermal expansion coefficient of 5.times.10.sup.-6 /.degree.C. or more and an average particle size of 1 to 500 nm. The sintered body is produced by wet mixing silicon nitride powder, at least two sintering aids selected from among Y.sub.2 O.sub.3, Al.sub.2 O.sub.3, AlN and MgO and at least one compound selected from among the oxides, nitrides, carbides and silicides of the elements, excluding Si and C, of the groups IIa, IIIa, IVa, Va, VIa, IIb, IIIb and IVb of the Periodic Table to form a molding; and heat treating under the specified conditions.

Abstract: The present invention relates to improvement of a quadrupole electrode for use in a mass spectrometer or the like, in which two pairs of electrode rods 1, 2, 3 and 4 formed in such a manner that the section of the opposed face of each rod is hyperbolic or circular, and each electrode rod is made of a ceramic and the surface of the electrode is coated with a coating layer 5 of a conductive metal. Further, the present invention relates to a production process, characterized by incorporating such four electrodes at predetermined intervals. Since the electrodes are mainly made of a ceramic which is easily formable with a high dimensional accuracy, the adjustment of the positional relationship between the electrodes during assembling can be made without much effort, which enables a quadrupole electrode having a high performance to be provided with a good reproducibility at a low cost.

Abstract: Described are sintered silicon nitride bodies useful as materials for parts required to have strength, especially excellent impact strength for items such as automobile parts and machine parts. The sintered Si.sub.3 N.sub.4 bodies contain 80-98 wt. % of silicon nitride and have a porosity not higher than 3% and an shock compressive elasticity limit of at least 15 GPa.

Abstract: A high-strength silicon nitride sintered body having a flexural strength of 100 kg/mm.sup.2 or higher and a process for producing the same are disclosed, the sintered body comprising not less than 90% by weight of a single crystalline phase of silicon aluminum oxynitride (Si.sub.6-z Al.sub.2 O.sub.z N.sub.8-z, wherein z is a number of from 0 to 4.2) having an average longer diameter of not more than 5 .mu.

Abstract: A ceramics composite material containing crystallized glass as the matrix and fibers or whiskers of ceramics as a reinforcement material, is obtained by melting original glass to form crystallized glass, compounding the same with fibers or whiskers of oxide ceramics and thereafter crystallizing the original glass. This ceramics composite material does not form any voids and can easily contain at least 50 volume percent of the reinforcement material, whereby a good mechanical strength and fracture toughness are achieved. In the compounding step, the content of the reinforcement can be further increased by forcing out any excess part of the original glass from the reinforcement material by applying pressure to a substance obtained by mixing the original glass with the reinforcement. Further, the ceramics composite material can be efficiently formed into a desired configuration by heating because the original glass flows viscously.

Abstract: A heat conductive aluminum nitride sintered body contains 100 parts by weight of aluminum nitride, at least 0.005 parts by weight and not more than 0.5 parts by weight of carbon, at least 0.01 parts by weight and not more than 15 parts by weight of a rare earth aluminum oxide in terms of the simple substance of a rare earth element, and at least 0.01 parts by weight and not more than 15 parts by weight of at least one element selected from a group of compounds containing elements belonging to the groups IVB, VB and VIB of the periodic table in terms of the simple substance of the element. Such a sintered body has a heat conductivity of at least 100 W/m.multidot.K. and not more than 270 W/m.multidot.K. at room temperature.