# US 10,370,251 B2 · Agglomerated boron nitride particles, production method for agglomerated boron nitride particles, resin composition including agglomerated boron nitride particles, moulded body, and sheet

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- Number: US 10,370,251 B2
- Document ID: US10370251B2
- Status: Granted
- Kind: B2
- Application number: 16/106,120
- Filed: 2018-08-21
- Published: 2018-12-13
- Granted: 2019-08-06
- Earliest claimed: 2014-02-05
- Assignees: Mitsubishi Chemical Corporation
- Applicants: Mitsubishi Chemical Corporation
- Inventors: Katsura Ikemiya; Masanori Yamazaki; Takuya Suzuki; Kazuki Takeda; Toshiyuki Sawamura; Sawa Hiramatsu; Tatsushi Isojima
- Web page: https://patentgrep.com/patent/US10370251B2

## CPC

- C01B 21/0648: {After-treatment, e.g. grinding, purification (transformation of hexagonal into cubic or wurtzitic boron nitride C04B35/5831)}
- C08K 3/38: Boron-containing compounds
- C08L 101/00: Compositions of unspecified macromolecular compounds
- C09K 5/14: Solid materials, e.g. powdery or granular
- C01P 2002/60: Compounds characterised by their crystallite size
- C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram
- C01P 2002/74: by peak-intensities or a ratio thereof only
- C01P 2004/04: obtained by TEM, STEM, STM or AFM
- C01P 2004/32: Spheres
- C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer
- C01P 2006/12: Surface area
- C01P 2006/32: Thermal properties
- C08K 2003/385: {Binary compounds of nitrogen with boron}
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

The present invention addresses the problem of providing agglomeraterd boron nitride particles which are suitable to be used as a thermally conductive filler for a heat dissipation sheet of a power semiconductor device, and which exhibit excellent isotropy of thermal conductivity, excellent degradation resistance, and excellent kneadability with respect to resin. The agglomerated boron nitride particles are obtained by agglomerating boron nitride primary particles. The agglomerated BN articles are characterized in that: a peak area intensity ratio ((100)/(004)) of a (100) plane to a (004) plane of the BN primary particles is 0.25 or more, and the average crystallite size of the BN primary particles obtained from a (002) plane peak of the BN primary particles is 375 Å or more.

## Claims

### Claim 1

An agglomerated boron nitride particle ( “agglomerated BN particle”) constituted by boron nitride primary particles (“BN primary particles”),
wherein a peak area intensity ratio ((100)/(004)) of a (100) plane to a (004) plane of the BN primary particles is 0.25 or more, the peak intensity ratio being obtained by subjecting, to a powder X-ray diffraction measurement, a pellet-shaped sample moulded at a moulding pressure of 0.85 ton/cm2 using a 10 mmφ powder pellet moulding machine,
the average crystallite size of the BN primary particles obtained from a (002) plane peak of the BN primary particles is 375 Å or more, the average crystallite size being obtained as a result of filling a glass sample plate having a depth of 0.2 mm with the agglomerated BN particles in such a way that the sample surface becomes smooth, and subjecting the agglomerated BN particles to a powder X-ray diffraction measurement, and
an average particle diameter D50 of the agglomerated BN particle is 26 μm or more.

### Claim 2 (depends on 1)

The agglomerated BN particle according to claim 1, wherein a specific surface area of the agglomerated BN particles is 8 m2/g or less.

### Claim 3 (depends on 1)

The agglomerated BN particle according to claim 1, wherein the agglomerated BN particle is spherical.

### Claim 4 (depends on 1)

The agglomerated BN particle according to claim 1, wherein the agglomerated BN particle has a card-house structure.

### Claim 5 (depends on 1)

A composition of the agglomerated BN particle which is a mixture of the agglomerated BN particle according to claim 1 and filler.

### Claim 6 (depends on 1)

A resin composition comprising agglomerated BN particles, comprising resin and the agglomerated BN particle according to claim 1.

### Claim 7 (depends on 1)

A moulded body comprising the agglomerated BN particles according to claim 1.

### Claim 8 (depends on 1)

A method of producing the agglomerated BN particle according to claim 1, comprising:
granulating slurry of raw material boron nitride powder ( “BN slurry”); and
performing heating treatment,
wherein in the granulating, a viscosity of the BN slurry is 200 mPa·s or more and 5000 mPa·s or less, and
the heating treatment is performed at 1800° C. or more and 2300° C. or less.

### Claim 9 (depends on 8)

The method according to claim 8, wherein an oxygen concentration in the raw material boron nitride powder is 1% by mass or more and 10% by mass or less.

### Claim 10

A sheet comprising agglomerated boron nitride particles (“agglomerated BN particles”),
wherein a peak intensity ratio ((100)/(004)) of a (100) plane to a (004) plane of boron nitride primary particles (hereinafter referred to as “BN primary particles”) in the sheet obtained by subjecting the sheet to an X-ray diffraction measurement is 1.0 or more,
an average crystallite size of the BN primary particles obtained from a (002) plane peak of the BN primary particles in the sheet obtained by subjecting the sheet to an X-ray diffraction measurement is 375 Å or more, and
an average particle diameter D50 of the agglomerated BN particles is 26 μm or more.

### Claim 11 (depends on 10)

The sheet according to claim 10, wherein the peak area intensity ratio ((100)/(004)) of the (100) plane to the (004) plane of the boron nitride primary particles (hereinafter referred to as “BN primary particles”) in the sheet obtained by subjecting the sheet to an X-ray diffraction measurement is 0.6 or more.

### Claim 12 (depends on 10)

A device comprising the sheet according to claim 10 as a part of a member of the device.