Abstract: A negative electrode active material for a lithium ion secondary battery, made up of substantially spherical graphite particles (A), having fine protrusions on the surfaces thereof and obtained by impregnating and coating substantially spherical graphite particles with a mixture of pitch and carbon black, followed by baking in a range of 900 to 1500° C. In accordance with Raman spectroscopic analysis of the particles (A) using argon laser Raman scattering light, there exists a G-band composite peak comprising peaks in the vicinity of 1600 cm?1, and 1580 cm?1, respectively, and at least one peak in the vicinity of D-band at 1380 cm?1, an interlayer distance of the lattice plane d002, obtained by wide-range X-ray diffraction, being in the range of 0.335 to 0.337 nm.

Abstract: A ball valve seat in which a resin or metal impregnated graphite seal ring and an L-shaped metal retainer are integrated by a shrink fit method. The graphite seal ring is provided with a continuous rib having a height of 50 to 250 ?m on the outer periphery of the graphite seal ring. The rib preferably has arc curve of radius R slopes on both sides of the rib from the top to the bottom, and the width L of the bottom of the rib is preferably 550 to 1100 ?m.

Abstract: A negative electrode active material for a lithium ion secondary battery, made up of substantially spherical graphite particles (A), having fine protrusions on the surfaces thereof and obtained by impregnating and coating substantially spherical graphite particles with a mixture of pitch and carbon black, followed by baking in a range of 900 to 1500° C. In accordance with Raman spectroscopic analysis of the particles (A) using argon laser Raman scattering light, there exists a G-band composite peak comprising peaks in the vicinity of 1600 cm?1, and 1580 cm?1, respectively, and at least one peak in the vicinity of D-band at 1380 cm?1, an interlayer distance of the lattice plane d002, obtained by wide-range X-ray diffraction, being in the range of 0.335 to 0.337 nm.

Abstract: A gas impermeabe coating composed of mainly silicon carbide (SiC) without cracks, comprising of a metallic silicon powder as a silicon source, a phenolic resin as a carbon source, a silicon carbide (SiC) powder and solvent are mixed. A mixture is applied to a graphite substrate material, dried and treated in an inert gas atmosphere at temperature from 1500° C. to 2500° C., preferably around 2000° C., with the silicon carbide powder existence in the coating mixture. The metallic silicon powder and carbon constituting the phenolic resin are reacted to form silicon carbide (SiC), thereby a coating film with no cracks is obtained on the graphite substrate material, such as carbon fiber felt molded heat insulation material.

Abstract: A negative electrode active material for lithium ion capacitor, which reduces the thickness of a negative-electrode active material layer while maintaining the conventional level of energy density. The negative-electrode active material is a composite carbon material manufactured by kneading a carbon black having an average particle diameter of 12 to 300 nm with a carbon precursor such as pitch, the resulting mixture is baked or graphitized baking between 800° C. to 3200° C., and then pulverized such that the average particle diameter (D50) thereof is 1 to 20 ?m and the BET specific surface area is between 100-350 m2/g. An initial charging capacity is at least 700 mAh/g, and the cell volume is reduced as the thickness of the negative electrode active material layer becomes thinner than the conventional one.

Abstract: A negative electrode active material for a lithium ion secondary battery, made up of substantially spherical graphite particles (A), having fine protrusions on the surfaces thereof and obtained by impregnating and coating substantially spherical graphite particles with a mixture of pitch and carbon black, followed by baking in a range of 900 to 1500° C. In accordance with Raman spectroscopic analysis of the particles (A) using argon laser Raman scattering light, there exists a G-band composite peak comprising peaks in the vicinity of 1600 cm?1, and 1580 cm?1, respectively, and at least one peak in the vicinity of D-band at 1380 cm?1, an interlayer distance of the lattice plane d002, obtained by wide-range X-ray diffraction, being in the range of 0.335 to 0.337 nm.

Abstract: A negative electrode active material for a lithium ion rechargeable battery having high electrode density, excellent in permeability of an electrolyte, less in capacity loss due to charging/discharging, and excellent in cycle performance is provided at a low cost. The negative electrode active material is a mixture of three kinds of graphite powders having different hardnesses and shapes from one another, with a binder added thereto and is coated onto a metallic current collector to be dried and pressed, thereby rendering an electrode density not lower than 1.7 g/cm3.

Abstract: A cylindrical thin-wall sleeve including an SiC fiber-reinforced SiC composite material (SiC/SiC), which has a porosity of 40% or less and a wall thickness of 5 mm or less.

Abstract: The invention is related to a package for packing a cylindrical carbon heater, used for manufacturing a mono crystal body and a method of forming the same, in which the cylindrical carbon heater is held sandwiched at the opposite ends between a base member and a plurality of retainer members, and compressive forces are applied independently to different parts of the carbon heater on the base member via the respective retainer members.

Abstract: A method of manufacturing split crucible pieces of a multiple-piece crucible comprising an integral assembly of two or more split crucible pieces and having a spherical bottom inner surface. The split crucible pieces are manufactured from a work mass graphite material by mechanical processing, comprising a step of forming a blind annular groove coaxial with the work by cutting the work from an end thereof toward the other end, a step of axially splitting the work into two or more pieces, constituting eventual split crucible pieces, and a step of cutting each split crucible piece from the side thereof opposite the sector-like or polygonal profile surface side by using a spherical acutting means, thereby forming a spherical inner bottom surface.

Abstract: The present invention provides a process for producing silicon carbide fibers having a C/Si molar ratio of from 0.85 to 1.39 and excellent in heat resistance and strength at high temperatures, while conventional processes have not been able to produce the fibers having the ratio of less than 1.56.The process of the present invention comprises the steps of rendering infusible precursory fibers made from an organosilicon polymer compound to obtain infusible fibers, then primarily baking the infusible fibers in a hydrogen gas-containing atmosphere while raising the temperature thereof to obtain primarily baked fibers, and further secondarily baking the primarily baked fibers to obtain final fibers. The secondary baking is performed in the atmosphere of a mixed gas of an inert gas with hydrogen chloride gas at 1,500.degree. to 2,200.degree. C.

Abstract: This invention concerns a method for water-cooling directly a vertical train of graphite electrodes connected to each other, by using a cooling water sprayed directly onto the outer periphery surface of at least one graphite electrode consisting of an upper portion of graphite electrode train, in which the cooling water is directed at the upward or downward inclination with respect to the horizontal level and said cooling liquid is sprayed simultaneously at a flow rate ranging between 0.8 liters/minute and 40 liters/minute.

Abstract: A microspherical packing for liquid chromatography, which comprises a porous silicon carbide having numerous through-pores, and a process for producing said microspherical packing.

Abstract: A silicon carbide fiber having low specific electric resistance and excellent mechanical properties and a method for manufacturing the fiber.The silicon carbide fiber is characterized in that an amorphous carbon film is formed on the surface thereof. The fiber is manufactured by heating an antimelt-treated polycarbosilane fiber at a temperature not exceeding 1000.degree. C. in an inert gas atmosphere followed by heating at a temperature of greater than 1000.degree. C. and up to 1500.degree. C. in an atmosphere of a mixture of hydrocarbon gas and inert gas.

Abstract: A super heat-resistant silicon carbide fiber has an oxygen content of less than 0.1% by weight. In a process for producing the super heat-resistant silicon carbide fiber, a precursor fiber prepared by spinning a polycarbosilane having an oxygen content of less than 0.8% by weight is irradiated with a radiation in an oxygen-free atmosphere or in vacuo to make the precursor fiber infusible. The infusibilized fiber is fired in an oxygen-free atmosphere or in vacuo at a temperature of from 1000.degree. to 2200.degree. C. without exposure to an oxidizing atmosphere; or stabilized in the same atmosphere at a temperature of from 300.degree. to 600.degree. C. without exposure to an oxidizing atmosphere and fired in an oxygen-free atmosphere or in vacuo at a temperature of from 1000.degree. to 2200.degree. C.

Abstract: An adsorption type packing for gas chromatography composed of finely divided carbon particles in whole, and having a ratio of nitrogen gas adsorption at a relative pressure of 0.3 (V.sub.0.3) to nitrogen gas adsorption at a relative pressure of about 1.0 (V.sub.1.0) each in the adsorption isotherm of said packing, V.sub.0.3 /V.sub.1.0, of 0.9 or more and a BET specific surface area of 1,000 to 2,000 m.sup.2 /g; and a process for producing said packing.

Abstract: A packing material for liquid chromatography is produced by mixing 1.0 part by weight of carbon black, 0.5 to 2.5 parts by weight of one or a mixture of a synthetic resin which can be graphitized by heating and a toluene- or benzene-soluble component of pitches, and an organic solvent to obtain a mixture. The carbon black has a particle diameter of 12 to 40 nm, a specific surface area of 50 to 650 m.sup.2 /g, a DBP oil absorption amount of 50 to 150 ml/100 g. The synthetic resin is one selected from phenol resin, furan resin, furfural resin, divinylbenzene resin and urea resin. The pitches are ones selected from petroleum pitches, coal-tar pitches and liquefied coal oil. The mixture is granulated by spray granulation or emulsion granulation to obtain granules whose ratio L.sub.min /L.sub.max of a minor axis diameter L.sub.min to a major axis diameter L.sub.max is 0.90 to 1.0. The heat treatment of the granules is also made in an inert gas under pressure.

Abstract: An organosilicon high molecular compound having a skeleton of silicon and carbon or a compound obtained by polymerization of an organometallic compound and the organosilicon high molecular compound is melted into a fiber, then the fiber is antimelt-treated in an oxidizing atmosphere, and the antimelt-treated yarns are thereafter heated in an atmosphere of inert gas to obtain a fiber of silicon carbide containing 2 to 20% by volume of oxygen. This fiber is further sintered in an atmosphere of inert gas at a temperature of 1400 to 2100 deg. C. and a pressure of 300 to 3000 kg/cm.sup.2. A sintered body of silicon carbide having an excellent bending strength is obtained without the use of a sintering agent or a binder. A fiber of silicon carbide having a predetermined oxygen content and a thin amorphous carbon layer thereon is obtained from the starting fiber by antimelt-treating and then heating in an atmosphere of a mixture of an inert gas and a hydrocarbon gas.

Abstract: Supports for gas chromatography comprising aggregates of finely divided carbon particles, said aggregates having a bulk specific gravity of 0.2 to 0.5 and a specific surface area of not more than 1.0 m.sup.2 /g and being produced by coating finely divided particles, such as carbon powder, having a diameter of 100 .mu.m or less and a content of particles having a diameter of 5 .mu.m or less of 20% or less, with a liquid thermosetting resin, and subjecting the coated particles to forming, curing, heat-treating, dividing and classifying; and a process for preparing said supports.

Abstract: A heat-resistant, corrosion-resistant inorganic composite body prepared by impregnating a heat-resistant inorganic compound body with at least one member selected from organosilicon compounds, metal alcoholates and organosilicon compound-metal alcoholate copolymers and then heat treating the thus impregnated body; and a process for preparing said heat-resistant, corrosion-resistant inorganic composite body.