Abstract: The principal objects of the invention is to provide diamond fine particles with a surface nature so improved as to form a stable, uniform suspension or dispersion in a common medium such as water and alcohol. Another object is to provide an effective technique for producing hydrophilic diamond fine particles by chemically modifying the particle surface nature, while removing at the same time contaminants and foreign materials which coexist with the diamond. In the invention, diamond particles are treated by boiling in the treatment fluid of sulfuric acid solution, which is in particular of concentrated or fuming nature, at a temperature more than 200° C., which is preferably 250° C. or more.

Abstract: Provided are a foaming propylene-ethylene random copolymer which is characterized in that (1) its ethylene unit content [x (wt. %)] falls between 0.2 and 10% by weight, (2) its MI falls between 1 and 16 g/10 min, (3) its boiling diethyl ether extraction [E (wt. %)] and x satisfy the relation of a formula (I):E.ltoreq.0.25x+1.1 (I),(4) its melting point [Tm (.degree. C.)] and x satisfy the relation of a formula (II):Tm.ltoreq.165-5x (II),(5) its isotactic triad fraction in the PPP chain moiety as measured through .sup.13 C.ltoreq.NMR is not smaller than 98 mol %, and preferably, (6) the relation between the time of relaxation .tau. (sec) of the copolymer and MI of the copolymer satisfies a formula (III):.tau..ltoreq.0.80-0.42.times.log MI (III),and also its foaming beads and cellular articles. The copolymer and its foaming beads have improved primary and secondary foamability, and the cellular articles of the copolymer have excellent mechanical properties including rigidity.

Abstract: The present invention provides an electron emitting device for efficiently emitting electron beams by applying a forward bias to an MIS, pn, and a pin structure using a diamond layer so as to supply electrons from an electron supply layer to a p-type diamond layer. Furthermore, the present invention provides a method for easily and efficiently performing important production processes for producing a highly efficient electron emitting device having a diamond layer and controlling a surface state of the diamond layer. A multi-layer structure including an electrode layer, an electron supply layer and a diamond layer is used as the structure thereof. Alternatively, the electron affinity state of the surface of the diamond layer is arbitrarily controlled by a method such as ultraviolet ray irradiation.

Abstract: A diamond-coated body is prepared by coating a diamond film on the surface of a sintered body by means of vapor phase synthesis, the sintered body being so prepared by subjecting a sintered body prepared from ceramics based on silicon nitride to heat treatment at the temperature of 1,400.degree. C. to 1,700.degree. C. as to give a crystalline intergranular phase. The resulting diamond-coated body has excellent adhesion between the diamond film and the substrate and it is appropriately employed for cutting tools and so on because, when applied to the cutting tools, they can be used for cutting for a long period of time.

Abstract: The present invention is directed to a diamond-coated body having a diamond coat film formed on the surface of a ceramic substrate containing acicular grains having a thickness of 0.2 .mu.m to 1 .mu.m and an aspect ratio of 2 or higher at the two-dimensional density of 30% or higher, and the diamond coat film has good adhesion to the ceramic substrate. Thus the diamond-coated body is superior in durability and can be appropriately utilized as cutting tools and so on.

Abstract: The present invention concerns a method of producing a diamond thin film. A plasma-activated gas, obtained by exciting a starting material containing a carbon source gas, is brought into contact with a surface of a substrate, on which a diamond thin film is to be formed under the presence of an auxiliary member placed adjacent to a protruded portion present at the surface of the substrate. The diamond thin film is thereby formed on the substrate. An apparatus for producing a diamond thin film by means of a microwave plasma method has an auxiliary member placed adjacent to a protruded portion present at the surface of the substrate on which the diamond thin film is to be formed.

Abstract: The present invention relates to a diamond-coated member characterized by superposing an acicular diamond layer, an intermediate layer formed by a metal belonging to either of the group IIIb, IVa, Va or VIa of the periodic table or by a compound containing the said metal, Si or B, and a non-acicular diamond layer on the surface of a base material and to a process for the preparation of a diamond-coated member characterized in that a diamond layer is formed on the surface of a base material by vapor phase synthesis method; the resulting diamond layer is converted into acicular diamond by exposing the resulting diamond layer to a gas obtainable by exciting an oxygen-containing etching gas; an intermediate layer comprising a metal belonging to either of the group IIIb, IVa, Va or VIa of the periodic table or by a compound containing the said metal, Si or B is formed on the resulting acicular diamond; and the resulting intermediate layer is exposed to a gas obtainable by exciting a raw material gas containing a c

Abstract: The present invention is directed to a method of producing a sintered hard metal having a diamond film wherein a gas that is obtained by activating a raw material gas containing 2 to 60 mol % of carbon monoxide and hydrogen gas is brought in contact with a sintered hard metal to form a diamond film, thereby a diamond film can be formed on said sintered hard metal with the adhesion of the diamond excellent.

Abstract: The present invention provides a diamond coated sintered body characterized by having a diamond film formed by a gas phase synthesis method on the surface of a sintered body obtained from a mixture of tungsten carbide and at least one compound selected from the group consisting of carbide and nitride of silicon or boron and, if necessary, additionally at least one compound selected from the group consisting of carbide, oxide, nitride, carbonitride, carbonate, boride and organic compound of at least one element selected from the group consisting of metals and rare earth elements belonging to Groups Ia, IIa, IIIa, IVa, Va, IIIb and IVb of the Mendelejeff's periodic table.

Abstract: The following are disclosed:a method for synthesis of diamond which is characterized by contacting a gas obtained by excitation of carbon monoxide and hydrogen in such a ratio as carbon monoxide being at least 1 mole % per total of carbon monoxide and hydrogen with a substrate in the presence of a reducing metal.A method for synthesis of diamond which is characterized by contacting with a substrate a gas obtained by excitation of carbon dioxide and hydrogen mixed at such a ratio of carbon dioxide being 0.1-20 mol % per hydrogen.A method for synthesis of diamond by depositing diamond on the surface of a substrate by introducing onto the surface of the substrate a plasma obtained from hydrogen and carbon source gas by irradiation of microwave in a plasma generator which is characterized in that progress of microwave oscillated from one microwave oscillator is divided and thus divided respective microwaves and led to a plurality of plasma generators.

Abstract: The following are disclosed:A method for synthesis of diamond which is characterized by contacting a gas obtained by excitation of carbon monoxide and hydrogen in such a ratio as carbon monoxide being at least 1 mol % per total of carbon monoxide and hydrogen with a substrate in the presence of a reducing metal.A method for synthesis of diamond which is characterized by contacting with a substrate a gas obtained by excitation of carbon dioxide and hydrogen mixed at such a ratio of carbon dioxide being 0.1-20 mol % per hydrogen.A method for synthesis of diamond by depositiong diamond on the surface of a substrate by introducing onto the surface of the substrate a plasma obtained from hydrogen and carbon source gas by irradiation of microwave in a plasma generator which is characterized in that progress of microwave oscillated from one microwave oscillator is divided and thus divided respective microwaves and led to a plurality of plasma generators.

Abstract: This invention provides a method for synthesis of diamond by contacting a substrate with a mixed gas of carbon source gas and hydrogen gas activated by irradiation with microwave to produce plasma, thereby to deposit diamond on the surface of the substrate wherein microwave is introduced from a plurality of directions to the substrate and an apparatus for synthesis of diamond which comprises at least one microwave oscillator which oscillates microwave, a plurality of waveguides for introducing from a plurality of directions the microwave oscillated from said microwave oscillator to a substrate for deposition of diamond, and a reaction chamber which is connected to said waveguides and in which diamond is deposited by generation of plasma thereby to form a diamond thin film on the surface of said substrate.

Abstract: A method for producing an alkenylbenzene by catalytically dehydrogenating an alkylbenzene non-oxidatively in the presence of steam in the reaction zone comprising a fixed-bed of potassium-containing dehydrogenation catalyst particles, wherein the potassium-containing dehydrogenation catalyst particles are prevented from powdering by (a) using a fixed-bed comprising particles of at least two kinds of potassium-containing dehydrogenation catalyst with respectively different potassium contents and (b) arranging the catalyst particles so that those with higher potassium content are not disposed on the inlet side of said catalyst bed with respect to the reaction.

Abstract: A resin composition comprising a modified polypropylene obtained by reacting a polypropylene with a liquid rubber and maleic anhydride in a solvent in the presence of a radical generator, another polyolefin and, if desired, an inorganic and/or an organic filler.The resin composition has excellent coating, adhesion and plating properties.

Abstract: A process for producing a resin composition having excellent plating properties comprising heating a mixture consisting substantially of 100 parts by weight of a polyolefin resin, 5 to 150 parts by weight of an inorganic filler, 1 to less than 20 parts by weight of a liquid rubber, 0.1 to 10 parts by weight of an unsaturated carboxylic acid and 0.001 to 10 parts by weight of a radical generator at 110.degree. to 280.degree. C. in the absence of solvents.

Abstract: A process for producing modified polypropylene comprising reacting polypropylene with a liquid rubber and maleic anhydride in a solvent in the presence of a radical generator.