Abstract: It is an object to achieve a resin sheet having high thermal conductance and high dielectric strength. Hexagonal boron nitride powder in accordance with an aspect of the present invention includes hexagonal boron nitride agglomerate particles each including agglomerated hexagonal boron nitride primary particles, and has a specific surface area of not less than 0.5 m2/g and not more than 5.0 m2/g. The hexagonal boron nitride primary particles each have a long diameter of not less than 0.6 ?m and not more than 4.0 ?m and an aspect ratio of not less than 1.5 and not more than 5.0.

Abstract: Provided is a method for producing, with a small amount of lithium, a hexagonal boron nitride powder containing thick hexagonal boron nitride particles. A method for producing a hexagonal boron nitride powder, including the steps of: preparing a mixed powder which contains an organic compound containing nitrogen atoms, a boron source which contains boron atoms whose molar ratio with respect to the nitrogen atoms is adjusted to be 0.26 or more and 0.67 or less, and an alkali metal in which lithium atoms are adjusted to be in a range of 30 mol % or more and less than 100 mol %, the alkali metal being present such that a molar ratio of the boron atoms with respect to alkali metal atoms contained in the alkali metal is 0.75 or more and 3.35 or less; and heating the mixed powder at a maximum temperature of 1200° C. or higher and 1500° C. or lower.

Abstract: Provided is a production method which makes it possible to improve a filling property, with respect to a resin, of a hexagonal boron nitride powder which contains hexagonal boron nitride particles each having a low aspect ratio, while maintaining low thermal conduction anisotropy of the hexagonal boron nitride powder. A method of producing a hexagonal boron nitride powder includes disintegrating, by a means which substantially does not involve pulverization of primary particles, a hexagonal boron nitride raw material powder which contains (i) hexagonal boron nitride particles each having an aspect ratio of 1.5 to 5.0 and (ii) an aggregate that contains hexagonal boron nitride particles each having an aspect ratio of more than 5.0.

Abstract: To provide a hexagonal boron nitride powder which contains agglomerates, has a maximum torque calculated by measuring in accordance with JIS-K-6217-4 of 0.20 to 0.50 Nm, a DBP absorption rate of 50 to 100 ml/100 g, a tap bulk density of 0.66 to 0.95 g/cm3 and reduced anisotropy of heat conduction and can provide high heat conductivity and dielectric strength to a resin composition produced by filling a resin therewith and a process for producing the powder by carrying out a reduction nitriding reaction using boron carbide.

Abstract: It is an object to achieve a resin sheet having high thermal conductance and high dielectric strength. Hexagonal boron nitride powder in accordance with an aspect of the present invention includes hexagonal boron nitride agglomerate particles each including agglomerated hexagonal boron nitride primary particles, and has a specific surface area of not less than 0.5 m2/g and not more than 5.0 m2/g. The hexagonal boron nitride primary particles each have a long diameter of not less than 0.6 ?m and not more than 4.0 ?m and an aspect ratio of not less than 1.5 and not more than 5.0.

Abstract: To provide a hexagonal boron nitride powder which contains agglomerates, has a maximum torque calculated by measuring in accordance with JIS-K-6217-4 of 0.20 to 0.50 Nm, a DBP absorption rate of 50 to 100 ml/100 g, a tap bulk density of 0.66 to 0.95 g/cm3 and reduced anisotropy of heat conduction and can provide high heat conductivity and dielectric strength to a resin composition produced by filling a resin therewith and a process for producing the powder by carrying out a reduction nitriding reaction using boron carbide.

Abstract: A dual-cure curable material kit comprising: (A) a radical-polymerizable monomer component; (B) a photopolymerization initiator component comprising (b1) an ?-diketone compound, (b2) an aliphatic tertiary amine compound having a tertiary amino group in which three saturated aliphatic groups are bonded to a nitrogen atom and one of the saturated aliphatic groups has an electron-withdrawing group as a substituent, and (b3) an s-triazine compound having a trihalomethyl group as a substituent, or a diaryliodonium salt compound; and a chemical polymerization initiator component (C) comprising (c1) an organic peroxide, and (c2) an N,N-di(hydroxyalkyl)-p-toluidine compound; which is packed separately at least in two packages so that the component (b2) and the component (b3) of the photopolymerization initiator component (B) are not packed together in a single package and the component (c1) and the component (c2) of the chemical polymerization initiator component (C) are not packed together in a single package.

Abstract: [Problems] To provide a chemical polymerization type curable composition which can achieve a very large strength of adhesion even without irradiated with light, and is used in the field of dental therapy. [Means for Solution] A dental curable composition comprising (A) a polymerizable monomer component containing an acidic group-containing polymerizable monomer, (B) water, and (C) a chemical polymerization initiator component comprising a radical-generating species and a reactive species that generates radicals upon reacting with the radical-generating species; wherein, the dental curable composition is stored being divided into a plurality of packages, and is polymerized and cured by mixing together the components contained in the packages; and wherein one package (I) among the packages contains the component (A) and the component (B), and, further, contains polyvalent metal ions in an amount of 0.

Abstract: A dual-cure curable material kit comprising: (A) a radical-polymerizable monomer component; (B) a photopolymerization initiator component comprising (b1) an ?-diketone compound, (b2) an aliphatic tertiary amine compound having a tertiary amino group in which three saturated aliphatic groups are bonded to a nitrogen atom and one of the saturated aliphatic groups has an electron-withdrawing group as a substituent, and (b3) an s-triazine compound having a trihalomethyl group as a substituent, or a diaryliodonium salt compound; and a chemical polymerization initiator component (C) comprising (c1) an organic peroxide, and (c2) an N,N-di(hydroxyalkyl)-p-toluidine compound; which is packed separately at least in two packages so that the component (b2) and the component (b3) of the photopolymerization initiator component (B) are not packed together in a single package and the component (c1) and the component (c2) of the chemical polymerization initiator component (C) are not packed together in a single package.

Abstract: [Problems] To provide a chemical polymerization type curable composition which can achieve a very large strength of adhesion even without irradiated with light, and is used in the field of dental therapy. [Means for Solution] A dental curable composition comprising (A) a polymerizable monomer component containing an acidic group-containing polymerizable monomer, (B) water, and (C) a chemical polymerization initiator component comprising a radical-generating species and a reactive species that generates radicals upon reacting with the radical-generating species; wherein, the dental curable composition is stored being divided into a plurality of packages, and is polymerized and cured by mixing together the components contained in the packages; and wherein one package (I) among the packages contains the component (A) and the component (B), and, further, contains polyvalent metal ions in an amount of 0.

Abstract: A method of preparing a ceramic artificial crown by applying at least one kind of dental porcelain onto the surface of a ceramic core molded by heating and softening a ceramic material and putting it into a mold with the application of pressure followed by firing wherein said mold is the one formed by burning a wax pattern after having removed a crucible former from an assembly which makes it possible to efficiently prepare a fully ceramic artificial crown of a high quality in a short period of time.

Abstract: A method of preparing a ceramic artificial crown by applying at least one kind of dental porcelain onto the surface of a ceramic core molded by heating and softening a ceramic material and putting it into a mold with the application of a pressure followed by firing; wherein said mold is the one formed by burning a wax pattern after having removed a crucible former from an assembly which makes it possible to efficiently prepare a fully ceramic artificial crown of a high quality in a short period of time.

Abstract: A method of preparing a ceramic artificial crown by applying at least one kind of dental porcelain selected from the group consisting of a body porcelain, an incisal porcelain and a translucent porcelain onto the surface of a ceramic core molded by heating and softening a ceramic material and putting it into a mold with the application of a pressure followed by firing; wherein

Abstract: A hydraulic damping device including a main damping body protected by a cylindrical portion with downwardly extending side walls. The damping device includes a flexible membrane which has a step portion, a main liquid chamber, an auxiliary liquid chamber and a partition formed in a cup-shape. A passage is made between the step portion of the flexible membrane and the interior of the partition. The partition divides the liquid chamber into a main liquid chamber and an auxiliary liquid chamber. The partition also includes a hole formed therein, a channel and a concave recess formed on the partition side wall between the hole and the channel. This structure permits the main liquid chamber to be connected to the auxiliary liquid chamber through the hole, the passage and the channel. The membrane is inserted into the interior of a cylindrical portion of the main damping body together with the partition and the damping liquid to define a simply constructed sub-assembly.

Abstract: In a fluid-filled vibration damping device, a rubber material is injection molded in the upper half of an inner space of a cylindrical insert plate 1 to form a damping rubber member 2 through which an inner tube 3 is retained. A concave 21 is formed in the center of the damping rubber member 2 in such a way that it extends from the periphery to a point close to the inner tube 3 such that both sidewalls thereof are left intact. The concave 21 provides a main fluid compartment A when the insert plate 1 is pressed and fixed in the outer tube. The insert plate 1 has a large concave in the lower half thereof and a plurality of openings are made in the sidewall of the concave 12 except for the bottom wall 121 thereof. A rubber layer 5, injection molded in the concave, has a central part of its width left intact in block form and part of this rubber layer provides a thin rubber wall that covers the openings in the sidewall of the concave 12 which face a cavity 53.