JP5579029B2 - Boron nitride powder, method for producing the same, composition containing the same, and heat dissipation material - Google Patents
Boron nitride powder, method for producing the same, composition containing the same, and heat dissipation material Download PDFInfo
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- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 title claims description 113
- 229910052582 BN Inorganic materials 0.000 title claims description 110
- 239000000843 powder Substances 0.000 title claims description 60
- 239000000203 mixture Substances 0.000 title claims description 9
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 239000000463 material Substances 0.000 title claims description 6
- 230000017525 heat dissipation Effects 0.000 title description 5
- 239000002245 particle Substances 0.000 claims description 67
- 239000002994 raw material Substances 0.000 claims description 28
- 239000011164 primary particle Substances 0.000 claims description 25
- 238000005087 graphitization Methods 0.000 claims description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 17
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims description 12
- 229910052799 carbon Inorganic materials 0.000 claims description 12
- 229910052783 alkali metal Inorganic materials 0.000 claims description 8
- 150000001340 alkali metals Chemical class 0.000 claims description 8
- 150000001341 alkaline earth metal compounds Chemical class 0.000 claims description 8
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 7
- 229920001971 elastomer Polymers 0.000 claims description 7
- 238000000034 method Methods 0.000 claims description 6
- 229920005989 resin Polymers 0.000 claims description 6
- 239000011347 resin Substances 0.000 claims description 6
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 5
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 5
- 239000012298 atmosphere Substances 0.000 claims description 4
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 2
- 229910052796 boron Inorganic materials 0.000 claims description 2
- 150000004767 nitrides Chemical class 0.000 claims description 2
- 238000001354 calcination Methods 0.000 claims 1
- 230000000052 comparative effect Effects 0.000 description 15
- 239000013078 crystal Substances 0.000 description 14
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 239000004327 boric acid Substances 0.000 description 5
- 229910000019 calcium carbonate Inorganic materials 0.000 description 5
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000006230 acetylene black Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 238000013329 compounding Methods 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000001339 alkali metal compounds Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- RQPZNWPYLFFXCP-UHFFFAOYSA-L barium dihydroxide Chemical compound [OH-].[OH-].[Ba+2] RQPZNWPYLFFXCP-UHFFFAOYSA-L 0.000 description 1
- 229910001863 barium hydroxide Inorganic materials 0.000 description 1
- AYJRCSIUFZENHW-DEQYMQKBSA-L barium(2+);oxomethanediolate Chemical compound [Ba+2].[O-][14C]([O-])=O AYJRCSIUFZENHW-DEQYMQKBSA-L 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 239000006232 furnace black Substances 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 229920006122 polyamide resin Polymers 0.000 description 1
- 229920005668 polycarbonate resin Polymers 0.000 description 1
- 239000004431 polycarbonate resin Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- 238000000634 powder X-ray diffraction Methods 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 230000002829 reductive effect Effects 0.000 description 1
- 229920002050 silicone resin Polymers 0.000 description 1
- 229920002379 silicone rubber Polymers 0.000 description 1
- 239000004945 silicone rubber Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- GCLGEJMYGQKIIW-UHFFFAOYSA-H sodium hexametaphosphate Chemical compound [Na]OP1(=O)OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])O1 GCLGEJMYGQKIIW-UHFFFAOYSA-H 0.000 description 1
- 235000019982 sodium hexametaphosphate Nutrition 0.000 description 1
- 238000001256 steam distillation Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000001577 tetrasodium phosphonato phosphate Substances 0.000 description 1
- 239000006234 thermal black Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910001868 water Inorganic materials 0.000 description 1
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Description
本発明は、窒化ホウ素粉末、特に粒子径が大きな白色の窒化ホウ素粉末、及びその用途に関する。 The present invention relates to boron nitride powder, in particular, white boron nitride powder having a large particle size, and use thereof.
炭素を用いた還元窒化による窒化ホウ素の製造方法としては、特許文献1で報告されている。この方法では高結晶性の窒化ホウ素が得られるものの、平均粒子径は10〜20μmである。近年要求されている高熱特性のレベルを満たすためには、平均粒子径が更に大きい窒化ホウ素が必要である。 Patent Document 1 reports a method for producing boron nitride by reductive nitridation using carbon. Although this method produces highly crystalline boron nitride, the average particle size is 10 to 20 μm. In order to satisfy the level of high thermal properties required in recent years, boron nitride having a larger average particle size is required.
また、窒化ホウ素の黄色度に関して、特許文献2の報告例がある。この報告例に基づくと黄色度が低く、白色度の高い窒化ホウ素が得られる。しかし製造方法は特許文献1と類似のため、やはり得られた窒化ホウ素の平均粒子径が不十分である。 Moreover, there is a report example of Patent Document 2 regarding the yellowness of boron nitride. Based on this report, boron nitride with low yellowness and high whiteness can be obtained. However, since the production method is similar to Patent Document 1, the average particle diameter of the obtained boron nitride is still insufficient.
窒化ホウ素粉末の粒子径(一次粒子径)を大きくすることも試みられており、特許文献3及び4によれば、30μm程度までの平均粒子径の大きい窒化ホウ素粉末が得られるが、加熱温度を高くして結晶成長させ、30μm以上に平均粒子径を大きくしようとすると、黄色度が増し、白色の窒化ホウ素粉末が得られないという問題があった。 It has also been attempted to increase the particle diameter (primary particle diameter) of boron nitride powder. According to Patent Documents 3 and 4, boron nitride powder having a large average particle diameter up to about 30 μm can be obtained. When the crystal growth is increased to increase the average particle size to 30 μm or more, there is a problem that yellowness increases and a white boron nitride powder cannot be obtained.
一方、窒化ホウ素粉末を製造する場合に、種結晶を使用することも公知である(特許文献5の請求項24、段落[0048]及び特許文献6請求項21、段落[0052]参照)が、特許文献5及び6に記載された発明において、種結晶は、t−BN(結晶性乱層構造窒化ホウ素)結晶への転化を促進し、純度の高いt−BN粉末を速やかに合成するために添加されるものであり、種結晶を添加することによりBN粉末の粒子径を大きくすることは示唆されていない。 On the other hand, it is also known to use seed crystals when producing boron nitride powder (see claim 24, paragraph [0048] and patent document 6, claim 21, paragraph [0052] of Patent Document 5), In the inventions described in Patent Documents 5 and 6, the seed crystal promotes the conversion to a t-BN (crystalline turbulent layer structure boron nitride) crystal and quickly synthesizes a highly pure t-BN powder. There is no suggestion to increase the particle size of the BN powder by adding seed crystals.
本発明は、上記のような従来技術に鑑み、粒子径が大きく熱伝導性に優れ、かつ、黄色度が低く白色の窒化ホウ素粉末、その製造方法、それを含有してなる組成物及び放熱材を提供することを課題とする。 In view of the prior art as described above, the present invention provides a white boron nitride powder having a large particle size and excellent thermal conductivity and low yellowness, a method for producing the same, a composition containing the same, and a heat dissipation material It is an issue to provide.
上記の課題を解決するために、本発明においては、以下の手段を採用する。
(1)一次粒子の平均粒子径30μm以上、黒鉛化指数1.5以下、黄色度3.0以下、窒化ホウ素純度98.0%以上、及び配向性指数20以上であることを特徴とする鱗片形状の窒化ホウ素粉末である。
(2)前記配向性指数が25〜40であることを特徴とする前記(1)の窒化ホウ素粉末である。
(3)前記(1)又は(2)の窒化ホウ素粉末の製造方法であって、ホウ酸(H3BO3)と炭素(C)のモル比が、H3BO3/C=0.7〜2.0の原料A100質量部とアルカリ金属もしくはアルカリ土類金属の化合物10〜20質量部からなる原料Bに対して、黒鉛化指数1.5以下、窒化ホウ素純度98.0%以上の窒化ホウ素粒子を、原料B100質量部に対して、0.5〜15質量部添加した原料Cを、窒素ガス又はアンモニアガス雰囲気下、1800〜2050℃で焼成することを特徴とする窒化ホウ素粉末の製造方法である。
(4)前記(1)又は(2)の窒化ホウ素粉末を、樹脂又はゴムに含有してなる組成物である。
(5)前記(4)の組成物を使用した電子部品又は照明部品の放熱材である。
In order to solve the above problems, the following means are adopted in the present invention.
(1) primary particles having an average particle size 30μm or more, graphitization index of 1.5 or less, yellowness 3.0 hereinafter, nitride boron purity 98.0% or more, and boron nitride scale shape, characterized in that it is oriented index 20 or more It is a powder.
(2) The boron nitride powder according to (1), wherein the orientation index is 25 to 40.
( 3 ) The method for producing boron nitride powder according to (1) or (2 ) above, wherein the molar ratio of boric acid (H 3 BO 3 ) to carbon (C) is H 3 BO 3 /C=0.7 to 2.0. Boron nitride particles having a graphitization index of 1.5 or less and a boron nitride purity of 98.0% or more to 100 parts by mass of the raw material A and 10 to 20 parts by mass of an alkali metal or alkaline earth metal compound are added. On the other hand, the raw material C added with 0.5 to 15 parts by mass is fired at 1800 to 2050 ° C. in a nitrogen gas or ammonia gas atmosphere, and is a method for producing boron nitride powder.
( 4 ) A composition comprising the boron nitride powder of (1) or (2) contained in a resin or rubber.
( 5 ) A heat dissipation material for an electronic component or lighting component using the composition of ( 4 ).
本発明により、粒子径が大きく、黄色度が低く、高純度の窒化ホウ素粉末が得られるという効果を奏する。 According to the present invention, it is possible to obtain a boron nitride powder having a large particle size, a low yellowness, and a high purity.
本発明の鱗片形状の窒化ホウ素粉末は、一次粒子の平均粒子径30μm以上、黒鉛化指数1.5以下、黄色度3.0以下、窒化ホウ素純度98.0%以上であることを特徴とするが、このような特性を有する窒化ホウ素粉末は、以下の方法で製造することができる。 The flaky boron nitride powder of the present invention is characterized by having an average primary particle diameter of 30 μm or more, a graphitization index of 1.5 or less, a yellowness of 3.0 or less, and a boron nitride purity of 98.0% or more. However, the boron nitride powder having such characteristics can be produced by the following method.
本発明においては、ホウ酸(H3BO3)と炭素(C)を、窒素ガス雰囲気中で以下の反応により反応させて窒化ホウ素(BN)を得る。
B2O3+3C+N2→2BN+3CO
上記の反応に使用されるB2O3は、原料であるホウ酸(H3BO3)が、脱水反応によりB2O3となったものである。
炭素(C)としては、カーボンブラック、グラファイト等を使用することができる。カーボンブラックとしては、アセチレンブラック、ファーネスブラック、サーマルブラック等を使用することができる。アセチレンブラックとしては、例えば、電気化学工業製「粒状グレード」がある。
反応ガスとしては、窒素ガスの代わりに、アンモニアガスを使用してもよい。
In the present invention, boric acid (H 3 BO 3 ) and carbon (C) are reacted by the following reaction in a nitrogen gas atmosphere to obtain boron nitride (BN).
B 2 O 3 + 3C + N 2 → 2BN + 3CO
B 2 O 3 used in the above reaction is obtained by boric acid (H 3 BO 3 ), which is a raw material, converted to B 2 O 3 by a dehydration reaction.
As the carbon (C), carbon black, graphite or the like can be used. As carbon black, acetylene black, furnace black, thermal black, etc. can be used. Examples of acetylene black include “granular grade” manufactured by Denki Kagaku Kogyo.
As the reaction gas, ammonia gas may be used instead of nitrogen gas.
窒化ホウ素粉末の一次粒子の平均粒子径を30μm以上とし、純度を98.0%以上とするために、ホウ酸(H3BO3)と炭素(C)のモル比、H3BO3/Cを0.7〜2.0とする。このモル比が2.0を超えると、一次粒子の平均粒子径が30μm以上にならず、このモル比が0.7未満では、窒化ホウ素の純度が98.0%にならないので、H3BO3/C=0.7〜2.0とする。 In order to make the average particle diameter of the primary particles of boron nitride powder 30 μm or more and the purity to 98.0% or more, the molar ratio of boric acid (H 3 BO 3 ) to carbon (C), H 3 BO 3 / C Is set to 0.7 to 2.0. If this molar ratio exceeds 2.0, the average particle diameter of the primary particles does not become 30 μm or more, and if this molar ratio is less than 0.7, the purity of boron nitride does not become 98.0%. Therefore, H 3 BO 3 / C = 0.7 to 2.0.
窒化ホウ素粉末の一次粒子の平均粒子径を30μm以上とし、黄色度を3.0以下とするために、反応温度を1800〜2050℃とする。反応温度が1800℃未満では、一次粒子の平均粒子径が30μm以上にならず、反応温度が2050℃を超えると、黄色度が3.0以下にならないので、反応温度を1800〜2050℃とする。 In order to set the average particle diameter of the primary particles of the boron nitride powder to 30 μm or more and the yellowness to 3.0 or less, the reaction temperature is set to 1800 to 2050 ° C. If the reaction temperature is less than 1800 ° C., the average particle diameter of the primary particles does not become 30 μm or more, and if the reaction temperature exceeds 2050 ° C., the yellowness does not become 3.0 or less. .
本発明においては、触媒として、アルカリ金属もしくはアルカリ土類金属の化合物を使用する。アルカリ金属の化合物としては、炭酸ナトリウム、炭酸リチウム、炭酸カリウム、水酸化ナトリウム、水酸化カリウム等を使用することができ、アルカリ土類金属の化合物としては、炭酸カルシウム、炭酸マグネシウム、炭酸バリウム、水酸化カルシウム、水酸化マグネシウム、水酸化バリウム等を使用することができる。 In the present invention, an alkali metal or alkaline earth metal compound is used as the catalyst. As the alkali metal compound, sodium carbonate, lithium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide and the like can be used. As the alkaline earth metal compound, calcium carbonate, magnesium carbonate, barium carbonate, water Calcium oxide, magnesium hydroxide, barium hydroxide, etc. can be used.
窒化ホウ素粉末の一次粒子の平均粒子径を30μm以上とし、純度を98.0%以上とするために、上記のホウ酸(H3BO3)と炭素(C)の原料A100質量部に対してアルカリ金属もしくはアルカリ土類金属の化合物を10〜20質量部とする。アルカリ金属もしくはアルカリ土類金属の化合物が10質量部未満では、一次粒子の平均粒子径が30μm以上にならず、アルカリ金属もしくはアルカリ土類金属の化合物が20質量部を超えると、窒化ホウ素の純度が98.0%にならないので、原料A100質量部に対してアルカリ金属もしくはアルカリ土類金属の化合物を10〜20質量部とする。 In order to make the average particle diameter of the primary particles of the boron nitride powder 30 μm or more and the purity 98.0% or more, the boric acid (H 3 BO 3 ) and carbon (C) raw material A100 parts by mass The alkali metal or alkaline earth metal compound is 10 to 20 parts by mass. If the alkali metal or alkaline earth metal compound is less than 10 parts by mass, the average particle diameter of the primary particles does not exceed 30 μm, and if the alkali metal or alkaline earth metal compound exceeds 20 parts by mass, the purity of boron nitride Therefore, the compound of alkali metal or alkaline earth metal is 10 to 20 parts by mass with respect to 100 parts by mass of the raw material A.
本発明においては、製造される窒化ホウ素粉末の一次粒子の平均粒子径を30μm以上とし、黒鉛化指数を1.5以下とするために、種結晶として、黒鉛化指数1.5以下、窒化ホウ素純度98.0%以上の窒化ホウ素粒子を使用することが重要である。種結晶の窒化ホウ素粒子の純度が98.0%未満では、製造される窒化ホウ素粉末の平均粒子径が30μm以上にならず、種結晶の窒化ホウ素粒子の黒鉛化指数が1.5を超えると、製造される窒化ホウ素粉末の黒鉛化指数が1.5以下にならないので、黒鉛化指数1.5以下、窒化ホウ素純度98.0%以上の窒化ホウ素粒子を種結晶とする。
黒鉛化指数1.5以下、窒化ホウ素純度98.0%以上を満足する窒化ホウ素粒子としては、例えば、電気化学工業製「SGPグレード」等の市販品を使用することができ、また、市販の窒化ホウ素粒子を処理して、このような特性としたものを使用してもよい。
種結晶とする窒化ホウ素粒子の平均粒子径は、15〜25μmが好ましい。
In the present invention, the average particle diameter of the primary particles of the boron nitride powder to be produced is 30 μm or more and the graphitization index is 1.5 or less. It is important to use boron nitride particles having a purity of 98.0% or more. When the purity of the boron nitride particles of the seed crystal is less than 98.0%, the average particle diameter of the produced boron nitride powder does not exceed 30 μm, and the graphitization index of the boron nitride particles of the seed crystal exceeds 1.5 Since the graphitization index of the produced boron nitride powder does not become 1.5 or less, boron nitride particles having a graphitization index of 1.5 or less and a boron nitride purity of 98.0% or more are used as seed crystals.
As the boron nitride particles satisfying a graphitization index of 1.5 or less and a boron nitride purity of 98.0% or more, for example, commercially available products such as “SGP grade” manufactured by Denki Kagaku Kogyo can be used. You may use the thing which processed the boron nitride particle | grains and was made into such a characteristic.
The average particle diameter of boron nitride particles used as seed crystals is preferably 15 to 25 μm.
また、種結晶である窒化ホウ素粒子の添加量も、製造される窒化ホウ素粉末の一次粒子の平均粒子径を30μm以上とするために重要である。上記のホウ酸(H3BO3)と炭素(C)の原料A100質量部に対してアルカリ金属もしくはアルカリ土類金属の化合物10〜20質量部からなる原料Bに対して、黒鉛化指数1.5以下、窒化ホウ素純度98.0%以上の窒化ホウ素粒子を、原料B100質量部に対して0.5〜15質量部添加する。上記の種結晶である窒化ホウ素粒子の添加量が、原料B100質量部に対して0.5未満でも、15質量部を超えても、製造される窒化ホウ素粉末の一次粒子の平均粒子径が30μm以上にならないので、上記の種結晶である窒化ホウ素粒子の添加量は、原料B100質量部に対して0.5〜15質量部とする。 Further, the amount of boron nitride particles added as seed crystals is also important in order to make the average particle diameter of the primary particles of the boron nitride powder produced to be 30 μm or more. The graphitization index of the raw material B consisting of 10 to 20 parts by mass of an alkali metal or alkaline earth metal compound with respect to 100 parts by mass of the raw material A of boric acid (H 3 BO 3 ) and carbon (C) is 1. 5 to 15 parts by mass of boron nitride particles having a boron nitride purity of 5 or less and a boron nitride purity of 98.0% or more are added to 100 parts by mass of the raw material B. Even if the addition amount of the boron nitride particles as the seed crystal is less than 0.5 or more than 15 parts by mass with respect to 100 parts by mass of the raw material B, the average particle diameter of primary particles of the produced boron nitride powder is 30 μm. Since it does not become the above, the addition amount of the boron nitride particle which is said seed crystal shall be 0.5-15 mass parts with respect to 100 mass parts of raw materials B.
窒化ホウ素の一次粒子は鱗片形状であるため、粒子の方向による熱伝導率等の特性の違い(異方性)が生じ易い。一方、この一次粒子が集結するといわゆる凝集粒子となり、凝集粒子中では一次粒子の方向がランダムになるため、異方性が弱まる。これら異方性を示す指標として配向性指数がある。配向性指数は、粉末X線回折による(002)回折線の強度I002と(100)回折線の強度I100との比(I002/I100)を算出することで求められる。完全にランダムな状態、すなわち無配向性の状態では配向性指数が1となり、この値から外れる程、凝集粒子がなくなり一次粒子として存在する。なお一般的にI002≧I100であるため、配向性指数は1以上となる。
本発明の窒化ホウ素粉末のような凝集粒子でない鱗片形状粒子の場合、配向性指数は20以上となり、これをもって鱗片形状であることが確認できる。
Since the primary particles of boron nitride are scaly, differences in characteristics (anisotropy) such as thermal conductivity depending on the direction of the particles are likely to occur. On the other hand, when the primary particles are aggregated, so-called agglomerated particles are formed, and the direction of the primary particles becomes random in the agglomerated particles, so that anisotropy is weakened. There is an orientation index as an index showing these anisotropies. The orientation index is obtained by calculating the ratio (I002 / I100) of the intensity (002) of the (002) diffraction line and the intensity I100 of the (100) diffraction line by powder X-ray diffraction. In a completely random state, that is, in a non-orientated state, the orientation index becomes 1, and as it deviates from this value, aggregated particles disappear and exist as primary particles. In general, since I002 ≧ I100, the orientation index is 1 or more.
In the case of scale-shaped particles that are not aggregated particles such as the boron nitride powder of the present invention, the orientation index is 20 or more, and it can be confirmed that this is scale-shaped.
本発明においては、上記のようにして製造した窒化ホウ素粉末を、樹脂又はゴムに配合して組成物とすることができる。特に、本発明の窒化ホウ素粉末は、粒子径が大きく、黄色度が低く白色であるため、この組成物を電子部品又は照明部品の放熱材として使用すると有効である。樹脂及び/又はゴムとしては、シリコーン樹脂、エポキシ樹脂、ポリアミド樹脂、ポリカーボネート樹脂、シリコーンゴム、ポリスチレンゴムなどを採用できる。
樹脂又はゴムに対する窒化ホウ素粉末の配合割合は、40〜60体積%とすることが好ましい。
In the present invention, the boron nitride powder produced as described above can be blended with a resin or rubber to form a composition. In particular, since the boron nitride powder of the present invention has a large particle size and a low yellowness and is white, it is effective to use this composition as a heat dissipation material for electronic parts or lighting parts. As the resin and / or rubber, silicone resin, epoxy resin, polyamide resin, polycarbonate resin, silicone rubber, polystyrene rubber, or the like can be used.
The compounding ratio of the boron nitride powder to the resin or rubber is preferably 40 to 60% by volume.
(実施例1〜5、8〜11、比較例1〜4、7〜10)
ホウ酸(関東化学製試薬)、炭素(電気化学工業製「粒状グレード」)を表1及び表2に示す質量比で混合し、混合原料Aを得た。
次に混合原料Aに炭酸カルシウム(関東化学製試薬)を表1及び表2に示す質量部で混合し、混合原料Bを得た。
更に混合原料Bに窒化ホウ素粒子(電気化学工業製「SGPグレード」、黒鉛化指数1.0、窒化ホウ素純度99.0%)を表1及び表2に示す質量部で混合し、混合原料Cを得た。
この混合原料Cを昇温速度15℃/分で昇温し、窒素ガス雰囲気中で表1及び表2に示す焼成温度で焼成した。その後室温まで冷却した後、硝酸水溶液で洗浄、乾燥、篩い分けをした。
以上のようにして、表1に示す実施例1〜5、8〜11、表2の比較例1〜4、7〜10の窒化ホウ素粉末を得た。得られた窒化ホウ素粉末の配向性指数が25〜40であることより、この粒子は鱗片形状であることを確認した。
得られた窒化ホウ素粉末の粒子を走査型電子顕微鏡(倍率100倍)で観察し、図1に例示される板状粒子が視野全体の95%以上存在していることより、この粒子は鱗片形状であることを確認した。
(Examples 1-5, 8-11, Comparative Examples 1-4, 7-10)
Boric acid (a reagent manufactured by Kanto Chemical) and carbon (“granular grade” manufactured by Denki Kagaku Kogyo) were mixed at a mass ratio shown in Tables 1 and 2 to obtain a mixed raw material A.
Next, the mixed raw material A was mixed with calcium carbonate (a reagent manufactured by Kanto Chemical Co., Ltd.) in parts by mass shown in Tables 1 and 2 to obtain mixed raw material B.
Further, boron nitride particles (“SGP grade” manufactured by Denki Kagaku Kogyo Co., Ltd., graphitization index 1.0, boron nitride purity 99.0%) are mixed with the mixed raw material B in parts by mass shown in Tables 1 and 2, and the mixed raw material C is mixed. Got.
The mixed raw material C was heated at a heating rate of 15 ° C./min and fired at the firing temperatures shown in Tables 1 and 2 in a nitrogen gas atmosphere. Then, after cooling to room temperature, it was washed with a nitric acid aqueous solution, dried and sieved.
As described above, boron nitride powders of Examples 1 to 5, 8 to 11 shown in Table 1 and Comparative Examples 1 to 4 and 7 to 10 of Table 2 were obtained. Since the orientation index of the obtained boron nitride powder was 25 to 40, it was confirmed that the particles had a scale shape.
The obtained boron nitride powder particles are observed with a scanning electron microscope (magnification 100 times), and 95% or more of the plate-like particles exemplified in FIG. 1 are present in a scaly shape. It was confirmed that.
(実施例6)
混合原料Bに添加する窒化ホウ素粒子として、電気化学工業製「HGPグレード」を窒素雰囲気下、2000℃、4時間焼成して、黒鉛化指数1.4、窒化ホウ素純度99.2%としたものを使用した以外は、実施例1と同様にして、表1に示す実施例6の窒化ホウ素粉末を得た。得られた窒化ホウ素粉末の配向性指数が30であることより、この粒子は鱗片形状であることを確認した。
(Example 6)
As boron nitride particles added to the mixed raw material B, “HGP grade” manufactured by Denki Kagaku Kogyo was calcined at 2000 ° C. for 4 hours in a nitrogen atmosphere to obtain a graphitization index of 1.4 and a boron nitride purity of 99.2%. The boron nitride powder of Example 6 shown in Table 1 was obtained in the same manner as Example 1 except that was used. Since the orientation index of the obtained boron nitride powder was 30, it was confirmed that the particles had a scaly shape.
(実施例7)
混合原料Bに添加する窒化ホウ素粒子として、電気化学工業製「SGPグレード」をボールミルで24時間混合して、黒鉛化指数1.1、窒化ホウ素純度98.2%としたものを使用した以外は、実施例1と同様にして、表1に示す実施例7の窒化ホウ素粉末を得た。得られた窒化ホウ素粉末の配向性指数が29であることより、この粒子は鱗片形状であることを確認した。
(Example 7)
The boron nitride particles to be added to the mixed raw material B, except that “SGP grade” manufactured by Denki Kagaku Kogyo Co., Ltd. was mixed with a ball mill for 24 hours to obtain a graphitization index of 1.1 and a boron nitride purity of 98.2%. In the same manner as in Example 1, the boron nitride powder of Example 7 shown in Table 1 was obtained. Since the orientation index of the obtained boron nitride powder was 29, it was confirmed that the particles had a scale shape.
(比較例5)
混合原料Bに添加する窒化ホウ素粒子として、電気化学工業製「HGPグレード」(黒鉛化指数1.7、窒化ホウ素純度98.5%)を使用した以外は、実施例1と同様にして、表2に示す比較例5の窒化ホウ素粉末を得た。得られた窒化ホウ素粉末の配向性指数が32であることより、この粒子は鱗片形状であることを確認した。
(Comparative Example 5)
As the boron nitride particles to be added to the mixed raw material B, the same as in Example 1 except that “HGP grade” (graphitization index 1.7, boron nitride purity 98.5%) manufactured by Denki Kagaku Kogyo was used. The boron nitride powder of Comparative Example 5 shown in 2 was obtained. Since the orientation index of the obtained boron nitride powder was 32, it was confirmed that the particles had a scale shape.
(比較例6)
混合原料Bに添加する窒化ホウ素粒子として、電気化学工業製「SGPグレード」をボールミルで48時間混合して、黒鉛化指数1.3、窒化ホウ素純度97.7%としたものを使用した以外は、実施例1と同様にして、表2に示す比較例6の窒化ホウ素粉末を得た。得られた窒化ホウ素粉末の配向性指数が29であることより、この粒子は鱗片形状であることを確認した。
(Comparative Example 6)
The boron nitride particles to be added to the mixed raw material B were obtained by mixing “SGP grade” manufactured by Denki Kagaku Kogyo with a ball mill for 48 hours to obtain a graphitization index of 1.3 and a boron nitride purity of 97.7%. In the same manner as in Example 1, the boron nitride powder of Comparative Example 6 shown in Table 2 was obtained. Since the orientation index of the obtained boron nitride powder was 29, it was confirmed that the particles had a scale shape.
得られた窒化ホウ素粉末の測定方法を以下に示す。
(a)平均粒子径
平均粒子径の測定には日機装製「マイクロトラック粒度分布測定装置MT3300EX」を用いた。0.2%ヘキサメタリン酸ナトリウム水溶液2mlと試料60mgを分散器(ホモジナイザー)にて分散させたスラリーを、上述測定機にて測定し、得られた50%値を平均粒子径とした。
The measuring method of the obtained boron nitride powder is shown below.
(A) Average particle diameter For measurement of the average particle diameter, “Microtrack particle size distribution measuring device MT3300EX” manufactured by Nikkiso was used. A slurry in which 2 ml of a 0.2% sodium hexametaphosphate aqueous solution and 60 mg of a sample were dispersed with a disperser (homogenizer) was measured with the above-mentioned measuring device, and the obtained 50% value was taken as the average particle size.
(b)黒鉛化指数(GI)
X線回折装置(理学電子社製「Geiger Flex 2013型」)にて2θ=40〜53°の範囲で測定し、41°付近((100)面)、43°付近((101)面)、50°付近((102)面)の回折ピークの積分強度比(つまり面積比)S(100)、S(101)、S(102)を求め、これより式、GI=[S{(100)+(101)}]/[S(102)]により算出した。
(B) Graphitization index (GI)
Measured in the range of 2θ = 40 to 53 ° with an X-ray diffractometer (“Geiger Flex 2013” manufactured by Rigaku Denshi Co., Ltd.), near 41 ° ((100) plane), near 43 ° ((101) plane), An integrated intensity ratio (that is, area ratio) S (100), S (101), S (102) of diffraction peaks near 50 ° ((102) plane) is obtained, and from this, the equation GI = [S {(100) + (101)}] / [S (102)].
(c)配向性指数
X線回折装置(理学電機社製「Geiger Flex 2013型」)にて2θ=25°〜45°の範囲で測定し、2θ=27〜28°付近((002)面)の回折線の強度I002、2θ=41°付近((100)面)の回折線の強度I100を求めた。(002)面と(100)面のピーク強度比=I(002)/I(100)を配向性指数として、算出した。
(C) Orientation index Measured in the range of 2θ = 25 ° to 45 ° with an X-ray diffractometer (“Geiger Flex 2013” manufactured by Rigaku Corporation), and around 2θ = 27 to 28 ° ((002) plane) Intensity of diffraction lines I002, 2θ = 41 ° vicinity ((100) plane) The diffraction line intensity I100 was determined. The peak intensity ratio between the (002) plane and the (100) plane = I (002) / I (100) was calculated as the orientation index.
(d)黄色度
黄色度の測定には日本電色社製「ZE−6000」を用いた。標準試料を用いて標準合わせをした後、石英ガラス製サンプルセルに試料を充填し、上記測定機にて測定し、得られた黄色度の値を測定値とした。
(D) Yellowness “ZE-6000” manufactured by Nippon Denshoku Co., Ltd. was used for measuring the yellowness. After standard alignment using a standard sample, the sample cell made of quartz glass was filled with the sample, measured with the above-mentioned measuring machine, and the obtained yellowness value was taken as the measured value.
(e)窒化ホウ素純度
窒化ホウ素純度は次の方法により求めた。試料を水酸化ナトリウムでアルカリ分解後、水蒸気蒸留法によってアンモニアを蒸留し、これをホウ酸液に捕集した。この捕集液を硫酸規定液で滴定し、窒素量(N)を求めた後、以下の式より窒化ホウ素純度(BN)を算出した。
BN(%)=N(%)×1.772
(E) Boron nitride purity Boron nitride purity was determined by the following method. After alkali decomposition of the sample with sodium hydroxide, ammonia was distilled by a steam distillation method and collected in a boric acid solution. The collected liquid was titrated with a sulfuric acid normal solution to determine the amount of nitrogen (N), and then boron nitride purity (BN) was calculated from the following formula.
BN (%) = N (%) × 1.772
表1より、ホウ酸/炭素のモル比、炭酸カルシウムの配合量、種結晶である窒化ホウ素粒子の黒鉛化指数(GI)、窒化ホウ素(BN)純度、添加量が、本発明の条件を満たす製造方法で得られた実施例1〜11の窒化ホウ素粉末は、一次粒子の平均粒子径30μm以上、黒鉛化指数(GI)1.5以下、黄色度3.0以下、及び窒化ホウ素(BN)純度98.0%以上であることが分かる。 From Table 1, the molar ratio of boric acid / carbon, the blending amount of calcium carbonate, the graphitization index (GI), boron nitride (BN) purity, and addition amount of boron nitride particles as seed crystals satisfy the conditions of the present invention. The boron nitride powders of Examples 1 to 11 obtained by the production method have an average primary particle diameter of 30 μm or more, a graphitization index (GI) of 1.5 or less, a yellowness of 3.0 or less, and boron nitride (BN). It turns out that it is more than purity 98.0%.
これに対して、表2より、以下のようなことが分かる。
比較例1は、ホウ酸/炭素のモル比が0.7未満であったため、得られた窒化ホウ素粉末は、純度が97.7%と低くなり、比較例2は、ホウ酸/炭素のモル比が2.0を超えていたため、得られた窒化ホウ素粉末は、一次粒子の平均粒子径が23μmと小さくなった。
In contrast, Table 2 shows the following.
Since Comparative Example 1 had a boric acid / carbon molar ratio of less than 0.7, the obtained boron nitride powder had a purity as low as 97.7%, and Comparative Example 2 had a boric acid / carbon molar ratio. Since the ratio exceeded 2.0, the obtained boron nitride powder had an average primary particle size as small as 23 μm.
比較例3は、炭酸カルシウムの配合量が混合原料Aに対して10質量部未満であったため、得られた窒化ホウ素粉末は、一次粒子の平均粒子径が24μmと小さくなり、比較例4は、炭酸カルシウムの配合量が混合原料Aに対して20質量部を超えていたため、得られた窒化ホウ素粉末は、純度が97.8%と低くなった。 In Comparative Example 3, since the compounding amount of calcium carbonate was less than 10 parts by mass with respect to the mixed raw material A, the obtained boron nitride powder had an average primary particle size as small as 24 μm. Since the blending amount of calcium carbonate exceeded 20 parts by mass with respect to the mixed raw material A, the purity of the obtained boron nitride powder was as low as 97.8%.
比較例5は、種結晶として添加した窒化ホウ素粒子のGIが1.5を超えていたため、得られた窒化ホウ素粉末は、GIが1.5を超えて大きくなり、比較例6は、窒化ホウ素粒子のBN純度が98.0%未満であったため、得られた窒化ホウ素粉末は、一次粒子の平均粒子径が28μmと小さくなり、比較例7は、窒化ホウ素粒子の添加量が混合原料B100質量部に対して0.5質量部未満であったため、得られた窒化ホウ素粉末は、一次粒子の平均粒子径が22μmと小さくなり、比較例8は、窒化ホウ素粒子の添加量が混合原料B100質量部に対して15質量部を超えていたため、得られた窒化ホウ素粉末は、一次粒子の平均粒子径が27μmと小さくなった。 In Comparative Example 5, since the GI of boron nitride particles added as a seed crystal exceeded 1.5, the obtained boron nitride powder was larger than GI of 1.5, and Comparative Example 6 was boron nitride. Since the BN purity of the particles was less than 98.0%, the obtained boron nitride powder had an average primary particle size as small as 28 μm. In Comparative Example 7, the amount of boron nitride particles added was 100 mass of mixed raw material B Since the amount of the boron nitride powder obtained was less than 0.5 parts by mass, the average particle size of the primary particles was as small as 22 μm. In Comparative Example 8, the amount of boron nitride particles added was 100 masses of the mixed raw material B100 Since the amount exceeded 15 parts by mass with respect to parts, the obtained boron nitride powder had an average primary particle size as small as 27 μm.
比較例9は、焼成温度が1800℃未満であったため、得られた窒化ホウ素粉末は、黄色度は1.6と低くなったが、一次粒子の平均粒子径が25μmと小さくなり、比較例10は、焼成温度が2050℃を超えていたため、得られた窒化ホウ素粉末は、一次粒子の平均粒子径は38μmと大きくなったが、黄色度が3.2と高くなった。 In Comparative Example 9, since the firing temperature was less than 1800 ° C., the obtained boron nitride powder had a yellowness as low as 1.6, but the average particle diameter of the primary particles became as small as 25 μm, and Comparative Example 10 Since the firing temperature exceeded 2050 ° C., the obtained boron nitride powder had an average primary particle size of 38 μm, but a yellowness of 3.2.
本発明の窒化ホウ素粉末は、粒子径が大きく熱伝導性に優れ、黄色度が低く白色であるため、この窒化ホウ素粉末を樹脂又はゴムに配合した組成物は、電子部品又は照明部品の放熱材として使用すると有効である。 Since the boron nitride powder of the present invention has a large particle size, excellent thermal conductivity, low yellowness and white color, a composition in which this boron nitride powder is blended with resin or rubber is a heat dissipation material for electronic parts or lighting parts. It is effective when used as.
Claims (5)
The heat radiating material of the electronic component or lighting component using the composition of Claim 4 .
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JP3461651B2 (en) * | 1996-01-24 | 2003-10-27 | 電気化学工業株式会社 | Hexagonal boron nitride powder and its use |
JP3521178B2 (en) * | 1997-07-09 | 2004-04-19 | 電気化学工業株式会社 | Hexagonal boron nitride powder and applications |
JPH11171511A (en) * | 1997-12-15 | 1999-06-29 | Shin Etsu Chem Co Ltd | Hexagonal boron nitride powder and its production |
JP3844455B2 (en) * | 2002-06-28 | 2006-11-15 | 電気化学工業株式会社 | Hexagonal boron nitride powder, method for producing the same, application |
JP2010042963A (en) * | 2008-08-18 | 2010-02-25 | Kaneka Corp | Manufacture method of hexagonal boron nitride |
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