An aluminum nitride film includes a polycrystalline aluminum nitride. A withstand voltage of the aluminum nitride film is 100 kV/mm or more.

Provided is a spherical aluminum nitride powder having a particle shape that is closer to sphericity. The spherical aluminum nitride powder according to the present invention, which contains a main component comprising AlN and a side component comprising a rare earth compound, is characterized in that at least 70% of particles in the powder have an outer peripheral shape having neither an angular edge part nor an uneven part in the plane projection image of individual particles.

A method of producing glass-coated aluminum nitride particles which includes a first step of mixing, while applying a shearing force by a mechano-chemical method, a mixture of aluminum nitride particles, and a composition powder containing a glass component, a second step of heat treating the mixture at a temperature of the glass transition temperature of the glass component or more, and 2000° C. or less, and a third step of crushing the heat treated product.

In a first step of a method for producing a transparent AlN sintered body, first, a formed body is prepared by forming a mixture obtained by mixing a sintering aid with an AlN raw-material powder containing a plate-like AlN powder whose plate surface is a c-plane and which has an aspect ratio of 3 or more. At this time, the mixture is formed such that the plate surface of the plate-like AlN powder is disposed along a surface of the formed body. In a second step, an oriented AlN sintered body is obtained by subjecting the formed body to hot-press sintering in a non-oxidizing atmosphere while applying a pressure to the surface of the formed body. In a third step, a transparent AlN sintered body is obtained by sintering the oriented AlN sintered body at normal pressure in a non-oxidizing atmosphere to remove a component derived from the sintering aid.

A method for producing an oriented AlN sintered body includes a first step of preparing a formed body by forming a mixture obtained by mixing a sintering aid with an AlN raw-material powder containing a plate-like AlN powder whose plate surface is a c-plane and which has an aspect ratio of 3 or more and an average thickness of 0.05 to 1.8 m, wherein the mixture is formed such that the plate surface of the plate-like AlN powder is disposed along a surface of the formed body; and a second step of obtaining an oriented AlN sintered body by subjecting the formed body to hot-press sintering in a non-oxidizing atmosphere while applying a pressure to the surface of the formed body.

The present disclosure relates to a powder composition comprising first and second agglomerates of inorganic particles, to a polymer composition comprising a polymer and said powder composition, and to a composite article made from said polymer composition. The present disclosure further relates to a process for producing said powder composition and to a process for making said composite article, and to the use of said powder composition as thermal conduction means to control the temperature of electrical and electronic components or assemblies or batteries. The present disclosure further relates to a kit of parts for producing said powder composition.

Glass-coated aluminum nitride particles and a method for producing the same. The glass-coated aluminum nitride particles include aluminum nitride particles and a glass phase which covers at least a part of the surface of each aluminum nitride particle. The glass phase is a composition which contains at least a glass component; and the proportion of the composition containing a glass component is 0.2 parts by weight to 5.0 parts by weight with respect to 100 parts by weight of the aluminum nitride particles. The composition containing the glass component further contains boron nitride particle; and the aluminum nitride particles have a volume cumulative d50 of from 10 m to 200 m.

A first object of the present invention is to provide a surface-modified inorganic nitride having excellent dispersibility. Furthermore, a second object of the present invention is to provide a composition, a thermally conductive material, and a device with a thermally conductive layer which contain the surface-modified inorganic nitride.

The surface-modified inorganic nitride of the present invention includes an inorganic nitride, and a compound which is represented by General Formula (I) and is adsorbed onto a surface of the inorganic nitride.

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In General Formula (1), n represents an integer of 3 or greater. X represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group. Y represents a single bond, O, CO, COO, OCO, S, CS, NR.sup.A, NN, or a divalent unsaturated hydrocarbon group. R.sup.A represents a hydrogen atom or an alkyl group. R.sup.1 and R.sup.2 each independently represent a substituent. Here, at least one of R.sup.1 or R.sup.2 represents a monovalent organic group containing a specific functional group selected from the group A of specific functional groups.

In General Formula (1), a plurality of X's may be the same as or different from each other. Moreover, a plurality of Y's may be the same as or different from each other.

To provide an aluminum nitride-based powder that includes less amount of fine powder that is hard to be completely removed, has superior filling performance for a polymeric material, and also has thermal conductivity. The present invention relates to an aluminum nitride-based powder comprising aluminum nitride-based particles, wherein (1) the average particle size D50 is 15 to 200 m; (2) a content of particles having a particle size of at most 5 m is at most 60% on a particle number basis; (3) a content of an alkaline earth metal element and a rare-earth element is at most 0.1 weight %; (4) a content of oxygen is at most 0.5 weight %; and (5) a content of silicon is at most 1000 ppm by weight, and a content of iron is at most 1000 ppm by weight.

An object of the present invention is to provide a surface-modified inorganic nitride having excellent dispersibility. Furthermore, another object of the present invention is to provide a composition, a thermally conductive material, and a device with a thermally conductive layer which contain the surface-modified inorganic nitride.

The surface-modified inorganic nitride of the present invention includes an inorganic nitride, and a compound which is represented by General Formula (I) and is adsorbed onto a surface of the inorganic nitride.

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