JPH08283008A - Production of low pressure phase boron nitride powder - Google Patents
Production of low pressure phase boron nitride powderInfo
- Publication number
- JPH08283008A JPH08283008A JP7088043A JP8804395A JPH08283008A JP H08283008 A JPH08283008 A JP H08283008A JP 7088043 A JP7088043 A JP 7088043A JP 8804395 A JP8804395 A JP 8804395A JP H08283008 A JPH08283008 A JP H08283008A
- Authority
- JP
- Japan
- Prior art keywords
- melamine
- boron nitride
- pressure phase
- atmosphere
- borate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、低圧相窒化ほう素粉末
の製造方法、特に高品質の粉末を高い生産性で製造する
方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing low-pressure phase boron nitride powder, and more particularly to a method for producing high quality powder with high productivity.
【０００２】[0002]
【従来の技術】低圧相窒化ほう素粉末は、黒鉛類似の層
状構造を有し、熱伝導性、絶縁性、化学的安定性、固体
潤滑性、耐熱衝撃性などの特性に優れ、これらの特性を
活かして固体潤滑・離型剤、樹脂やゴムの充填材、耐熱
性・絶縁性焼結体などに応用されている。2. Description of the Related Art Low-pressure phase boron nitride powder has a layered structure similar to graphite and has excellent properties such as thermal conductivity, insulation, chemical stability, solid lubricity, and thermal shock resistance. It has been applied to solid lubricants / release agents, resin and rubber fillers, heat resistant / insulating sintered bodies, etc.
【０００３】低圧相窒化ほう素粉末の製造方法の一例と
しては以下がある。 （１）ほう酸、酸化ほう素、ほう砂などのほう素と酸素
を含む化合物とをリン酸カルシウムなどの充填材に担持
させたのち、アンモニア雰囲気下で焼成する方法。 （２）上記ほう素化合物とジシアンジアミド、メラミ
ン、尿素などの窒素を含む化合物との混合物を焼成する
方法。 （３）上記ほう素化合物と炭素などの還元性物質との混
合物を窒素ガス雰囲気下で焼成する方法。 （４）ほう酸又は酸化ほう素、メラミンおよび水を含む
混合物から、濾過、遠心分離、乾燥などの方法により水
を除去したのち、これを非酸化性ガス雰囲気下で焼成す
る方法。The following is an example of a method for producing a low-pressure phase boron nitride powder. (1) A method in which boron such as boric acid, boron oxide, or borax and a compound containing oxygen are supported on a filler such as calcium phosphate, and then baked in an ammonia atmosphere. (2) A method of firing a mixture of the above boron compound and a compound containing nitrogen such as dicyandiamide, melamine and urea. (3) A method of firing a mixture of the above boron compound and a reducing substance such as carbon in a nitrogen gas atmosphere. (4) A method in which water is removed from a mixture containing boric acid or boron oxide, melamine and water by a method such as filtration, centrifugation or drying, and then the mixture is baked in a non-oxidizing gas atmosphere.
【０００４】しかしながら、（１）では焼成時にほう素
と酸素を含む化合物が融解するのでアンモニア雰囲気と
の接触面積が充分に大きくはならず、また（２）では窒
素を含む化合物が焼成時に気化あるいは分解しやすいた
め、いずれの方法においても反応率を著しく高めること
が困難である。（３）では酸洗浄などの簡便な後処理で
は除去困難な還元性物質が不純物として残留しやすくな
る。However, in (1), since the compound containing boron and oxygen melts during firing, the contact area with the ammonia atmosphere does not become sufficiently large, and in (2) the compound containing nitrogen is vaporized or burned during firing. Since it is easily decomposed, it is difficult to significantly increase the reaction rate by any method. In (3), a reducing substance that is difficult to remove by a simple post-treatment such as acid washing tends to remain as an impurity.
【０００５】一方、（４）の方法は、水の作用によりほ
う酸又は酸化ほう素とメラミンとが塩（ほう酸メラミ
ン）を形成して均一な原料混合物となるため、均質なＢ
Ｎ粉末を高い収率で製造できる方法として知られている
（USP 3,241,918 号明細書、特開昭６０−１５１２０２
号公報、特開昭６１−１９１５０５号公報、特開昭６１
−２８６２０７号公報等）が、この方法では他の方法と
異なり、原料混合物から水を除去するための濾過、遠心
分離、乾燥などの余分な工程が必要となるので生産性が
低くなるという問題がある。On the other hand, in the method (4), boric acid or boron oxide and melamine form a salt (melamine borate) due to the action of water to form a uniform raw material mixture, so that a homogeneous B mixture is obtained.
It is known as a method capable of producing N powder in a high yield (USP 3,241,918, JP-A-60-151202).
JP, JP 61-191505 A, JP 61
However, unlike the other methods, this method requires extra steps such as filtration, centrifugation, and drying for removing water from the raw material mixture, which causes a problem of low productivity. is there.
【０００６】[0006]
【発明が解決しようとする課題】本発明は、上記従来技
術の問題点を解決し、均質な低圧相窒化ほう素粉末を高
収率で、しかも濾過、遠心分離、乾燥などの余分な工程
を必要とせずに高い生産性で製造することを目的とする
ものである。DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and provides a homogeneous low-pressure phase boron nitride powder with a high yield, and an extra step such as filtration, centrifugation and drying. It is intended to be manufactured with high productivity without need.
【０００７】[0007]
【課題を解決するための手段】すなわち、本発明は、ほ
う酸とメラミンとをＢ／Ｎ原子比が１／１〜１／６とな
る割合で混合し、これを温度０〜２００℃、相対湿度５
％以上の水蒸気を含む雰囲気下で保持してほう酸メラミ
ンを形成させた後、非酸化性ガス雰囲気下、温度６００
〜２２００℃で焼成することを特徴とする低圧相窒化ほ
う素粉末の製造方法である。That is, according to the present invention, boric acid and melamine are mixed at a B / N atomic ratio of 1/1 to 1/6, and the mixture is mixed at a temperature of 0 to 200 ° C. and a relative humidity. 5
% In the atmosphere containing water vapor to form melamine borate, and then in a non-oxidizing gas atmosphere at a temperature of 600.
The method for producing a low-pressure phase boron nitride powder is characterized by firing at ˜2200 ° C.
【０００８】以下、さらに詳しく本発明について説明す
る。The present invention will be described in more detail below.
【０００９】窒化ほう素は生成する圧力の領域により、
特性や構造が大きく異なる２種類のものに分けられる。
このうち数千気圧以下の圧力で形成されるものが本発明
の低圧相窒化ほう素であり、数万気圧以上の高圧力で形
成されるものが高圧相窒化ほう素である。Boron nitride is produced by the region of pressure generated.
It can be divided into two types that differ greatly in characteristics and structure.
The low pressure phase boron nitride of the present invention is formed at a pressure of several thousand atmospheres or less, and the high pressure phase boron nitride is formed at a high pressure of tens of thousands atmospheres or more.
【００１０】低圧相窒化ほう素は、密度が２．５ｇ／ｃ
ｍ3 以下と低く、黒鉛類似の層状構造を有するため固体
潤滑性や耐熱衝撃性などが優れている。また、結晶性や
結晶構造により非晶質窒化ほう素（ａ−ＢＮ）、六方晶
窒化ほう素（ｈＢＮ）、菱面体晶窒化ほう素（ｒＢＮ）
などに分類される。The low-pressure phase boron nitride has a density of 2.5 g / c.
Since it is as low as m 3 or less, and has a layered structure similar to graphite, it has excellent solid lubricity and thermal shock resistance. In addition, amorphous boron nitride (a-BN), hexagonal boron nitride (hBN), rhombohedral boron nitride (rBN) depending on crystallinity and crystal structure.
Etc.
【００１１】一方、高圧相窒化ほう素は、密度が３．０
ｇ／ｃｍ3 以上と高く、ダイヤモンド類似の強固な共有
結合よりなるため耐摩耗性、熱伝導性などが優れてお
り、鉄系金属の切削、研削用工具材料や半導体素子の放
熱材料などとして用いられ、また結晶構造により立方晶
窒化ほう素（ｃＢＮ）やウルツ鉱型（高圧相六方晶）窒
化ほう素（ｗＢＮ）に分類される。On the other hand, the high-pressure phase boron nitride has a density of 3.0.
It has a high g / cm 3 or more, and because it consists of a strong covalent bond similar to diamond, it has excellent wear resistance and thermal conductivity. It is used as a tool material for cutting iron-based metals, as a tool material for grinding, and as a heat dissipation material for semiconductor elements. Further, it is classified into cubic boron nitride (cBN) and wurtzite type (high pressure phase hexagonal) boron nitride (wBN) according to the crystal structure.
【００１２】本発明は、上記（４）の低圧相窒化ほう素
粉末の製造法の改良に関するものであり、その大きな特
徴は、ほう酸とメラミンからなる混合原料を適度の湿気
を有する環境下に保持してほう酸とメラミンとの塩（ほ
う酸メラミン）を形成させそれを焼成することによっ
て、従来の水を作用させてほう酸メラミンを形成させる
場合に必要であった濾過、遠心分離、乾燥などの余分な
工程を経ないで均質な低圧相窒化ほう素粉末を高収率で
製造できることである。The present invention relates to the improvement of the method (4) for producing a low-pressure phase boron nitride powder, which is characterized mainly in that a mixed raw material composed of boric acid and melamine is kept in an environment having an appropriate humidity. Then, by forming a salt of boric acid and melamine (melamine borate) and calcining it, the excess of filtration, centrifugation, drying, etc., which was necessary when conventional water was allowed to act to form melamine borate, was added. That is, a homogeneous low-pressure phase boron nitride powder can be produced in a high yield without going through the steps.
【００１３】本発明で使用されるほう酸は、メラミンと
反応してほう酸メラミンを形成するものであり、その例
はオルトほう酸（Ｈ3 ＢＯ3 ）、メタほう酸（ＨＢ
Ｏ2 ）、テトラほう酸（Ｈ2 Ｂ4 Ｏ7 ）、無水ほう酸
（Ｂ2 Ｏ3 ）など、一般式（Ｂ2 Ｏ 3 ）・（Ｈ2 Ｏ）x
〔但しx ＝０〜３〕で示される化合物の１種又は２種以
上であるが、なかでもオルトほう酸は入手が容易でメラ
ミンとの混合性が良好であるので本発明には好適であ
る。The boric acid used in the present invention comprises melamine and
It reacts to form melamine borate, an example of which
Is orthoboric acid (H3BO3), Metaboric acid (HB
O2), Tetraboric acid (H2BFourO7), Boric anhydride
(B2O3) And the general formula (B2O 3) ・ (H2O) x
[However, 1 type or 2 types or more of the compound shown by x = 0 to 3]
As mentioned above, orthoboric acid is easy to obtain and
It is suitable for the present invention because it has good miscibility with min.
It
【００１４】ほう酸とメラミンの混合はボールミル、リ
ボンブレンダー、ヘンシェルミキサーなどの一般的な混
合機を用いて行うことができる。配合割合は、ほう酸の
ほう素原子（Ｂ）とメラミンの窒素原子（Ｎ）のＢ／Ｎ
原子比が１／１〜１／６となる割合、好ましくは１／２
〜１／４となる割合である。該Ｂ／Ｎ原子比が１／１を
こえると焼成後に未反応ほう酸の残留が顕著となり、ま
た１／６未満では焼成時に未反応メラミンの昇華が顕著
となって、いずれの場合も収率が低下する。The mixing of boric acid and melamine can be carried out by using a general mixer such as a ball mill, ribbon blender or Henschel mixer. The mixing ratio is B / N of boron atom (B) of boric acid and nitrogen atom (N) of melamine.
Atomic ratio of 1/1 to 1/6, preferably 1/2
It is a ratio of about 1/4. When the B / N atomic ratio exceeds 1/1, unreacted boric acid remains remarkably after firing, and when it is less than 1/6, unreacted melamine sublimates remarkably during firing, and in both cases, the yield is high. descend.
【００１５】本発明のＢ／Ｎ原子比を満たすほう酸とメ
ラミン（Ｃ3 Ｎ6 Ｈ6 ）の具体的な配合割合は、ほう酸
がオルトほう酸（Ｈ3 ＢＯ3 ）である場合、Ｈ3 ＢＯ3
／Ｃ 3 Ｎ6 Ｈ6 がモル比では６／１〜１／１、重量比で
は２．９４／１〜０．４９／１となる。Boric acid and a polymer satisfying the B / N atomic ratio of the present invention are
Ramin (C3N6H6), The specific mixing ratio is
Is orthoboric acid (H3BO3), H3BO3
/ C 3N6H6Is a molar ratio of 6/1 to 1/1 and a weight ratio of
Is 2.94 / 1 to 0.49 / 1.
【００１６】本発明は、上記ほう酸とメラミンの混合物
を温度０〜２００℃好ましくは４０〜１００℃の相対湿
度５％以上の水蒸気を含む雰囲気下で保持してほう酸メ
ラミンを形成させ、それを焼成するものである。ほう酸
メラミンの形成温度が０℃未満では反応速度が著しく遅
くなり、また２００℃をこえるとほう酸がガラス状に融
解し表面積が小さくなるので反応率が増大しなくなる。
さらには、ほう酸メラミンの形成雰囲気を相対湿度５％
以上の水蒸気を含む雰囲気下としたのは、相対湿度５％
未満の雰囲気では反応速度が著しく遅くなるからであ
る。In the present invention, the mixture of boric acid and melamine is kept in an atmosphere containing water vapor having a relative humidity of 5% or more at a temperature of 0 to 200 ° C., preferably 40 to 100 ° C. to form melamine borate, which is then calcined. To do. If the formation temperature of melamine borate is less than 0 ° C, the reaction rate becomes remarkably slow, and if it exceeds 200 ° C, boric acid melts into a glass and the surface area becomes small, so that the reaction rate does not increase.
Furthermore, the formation atmosphere of melamine borate is set to a relative humidity of 5%.
The above-mentioned atmosphere containing water vapor was set to have a relative humidity of 5%.
This is because the reaction rate becomes remarkably slow in an atmosphere of less than.
【００１７】上記温度と相対湿度の雰囲気下における保
持時間は、１〜１００時間程度である。なかでも、温度
Ｔ（℃）、相対湿度Ψ（％）及び保持時間ｔ（ｈｒ）が
以下の関係式を満たす条件でほう酸とメラミンの混合物
を保持してほう酸メラミンを形成させることである。こ
のような雰囲気は、恒温恒湿機、スチーム加熱炉などを
用いて容易に形成させることができる。雰囲気を形成す
る水蒸気以外のガスにはついて特に制限はなく、大気ガ
ス、窒素ガス、不活性ガスなどである。Ｔ≧−２０・ｌ
ｏｇ10（ｔ／４）＋｛（Ψ−１００）2 ／２０｝＋６０The holding time in the atmosphere of the above temperature and relative humidity is about 1 to 100 hours. Among them, the temperature T (° C.), the relative humidity Ψ (%) and the holding time t (hr) satisfy the following relational expression to hold a mixture of boric acid and melamine to form melamine borate. Such an atmosphere can be easily formed by using a thermo-hygrostat or a steam heating furnace. The gas other than water vapor forming the atmosphere is not particularly limited and includes atmospheric gas, nitrogen gas, inert gas and the like. T ≧ −20 · l
og 10 (t / 4) + {(Ψ-100) 2/20} +60
【００１８】ほう酸メラミンの形成は、熱重量測定／示
差熱分析（ＴＧ／ＤＴＡ）、Ｘ線回折測定などによって
容易に確認することができる。例えば、図１にはほう酸
メラミンの、また図２にはほう酸とメラミンの混合物の
ＴＧ／ＤＴＡ曲線をそれぞれ示したが、ほう酸とメラミ
ンの混合物（図２）では３５０℃付近にメラミンの昇華
による急激な重量減少および吸熱が現れるが、ほう酸メ
ラミンでは殆んど現れないことが特徴である。また、Ｘ
線回折測定においても、１２０℃以下の温度で形成され
たほう酸メラミンは、ほう酸およびメラミンのいずれと
も異なる独自の回折パターンを示すため、容易に確認す
ることができる（萩尾 剛、他；日本セラミックス協会
学術論文誌；１０２巻、１１号、１０５１〜１０５２頁
［１９９４年］）。しかしながら、１２０℃をこえる温
度で形成されたほう酸メラミンは非晶質であるので独自
の回折パターンを示さなくなるため注意が必要である。The formation of melamine borate can be easily confirmed by thermogravimetry / differential thermal analysis (TG / DTA), X-ray diffraction measurement and the like. For example, FIG. 1 shows the TG / DTA curves of melamine borate and FIG. 2 for the mixture of boric acid and melamine. In the mixture of boric acid and melamine (FIG. 2), the TG / DTA curve was rapidly increased by sublimation of melamine near 350 ° C. Although significant weight loss and endotherm appear, melamine borate almost does not. Also, X
Even in the line diffraction measurement, melamine borate formed at a temperature of 120 ° C. or lower exhibits a unique diffraction pattern different from that of boric acid and melamine, so that it can be easily confirmed (Take Hagio, et al .; The Ceramic Society of Japan). Academic journal; Volume 102, No. 11, pages 1051 to 1052 [1994]). However, it should be noted that melamine borate formed at a temperature over 120 ° C. is amorphous and does not show its own diffraction pattern.
【００１９】本発明によって製造されたほう酸メラミン
は従来のように水を含まないものであるため、それをそ
のままあるいは軽い解砕工程を行った後、濾過、遠心分
離、乾燥などの工程を経ることなくただちに焼成するこ
とができる。また、従来法では、水の除去されたほう酸
メラミンの嵩密度は著しく低下してしまうのでそれの回
復処理が必要であった（特開昭６１−２８６２０７号公
報）が、本発明においてはそのような処理は必要でなく
なるので生産性が高まる。また、ほう酸メラミンは焼成
時に融解しないので炉材の損耗を抑制することができ、
その結果、連続式炉による焼成が容易となる。Since melamine borate produced by the present invention does not contain water as in the conventional case, it may be subjected to steps such as filtration, centrifugation and drying, as it is or after a light crushing step. It can be baked immediately without. Further, in the conventional method, the bulk density of melamine borate from which water has been removed is remarkably reduced, and therefore a recovery treatment thereof has been necessary (Japanese Patent Laid-Open No. 61-286207). Since no special treatment is required, productivity is increased. Also, since melamine borate does not melt during firing, it is possible to suppress the wear of the furnace material,
As a result, firing in a continuous furnace becomes easy.
【００２０】焼成は、非酸化性ガス雰囲気下、温度６０
０〜２２００℃で行われる。６００℃未満では低圧相窒
化ほう素の生成速度が著しく遅くなり、また２２００℃
をこえると低圧相窒化ほう素が分解する。Firing is performed at a temperature of 60 in a non-oxidizing gas atmosphere.
It is carried out at 0 to 2200 ° C. If the temperature is lower than 600 ° C, the formation rate of low-pressure boron nitride is remarkably slow,
If it exceeds, the low-pressure phase boron nitride decomposes.
【００２１】本発明においては、焼成温度を調整するこ
とによって生成する低圧相窒化ほう素粉末の結晶性を変
えることができる。例えば、６００〜１０００℃の低温
では非晶質窒化ほう素（ａ−ＢＮ）粉末を生成させるこ
とができ、１５００〜２２００℃の高温では六方晶窒化
ほう素（ｈＢＮ）粉末を生成させることができる。In the present invention, the crystallinity of the low-pressure phase boron nitride powder produced can be changed by adjusting the firing temperature. For example, an amorphous boron nitride (a-BN) powder can be generated at a low temperature of 600 to 1000 ° C., and a hexagonal boron nitride (hBN) powder can be generated at a high temperature of 1500 to 2200 ° C. .
【００２２】焼成時の非酸化性ガス雰囲気下を形成する
ガスとしては、窒素ガス、アンモニアガス、水素ガス、
メタン、プロパンなどの炭化水素ガス、ヘリウム、アル
ゴンなどの希ガスである。これらのうち、入手しやすく
安価でありしかも２０００〜２２００℃の高温において
は低圧相窒化ほう素の分解を抑制する効果の大きい窒素
ガスが最適である。しかし、６００〜１０００℃の低温
に限っては、アンモニアガス又はアンモニアと炭化水素
の混合ガスが好適であり、炭素や酸素などの不純物含有
量の少ない高純度の低圧相窒化ほう素を製造することが
できる。Gases that form a non-oxidizing gas atmosphere during firing include nitrogen gas, ammonia gas, hydrogen gas,
It is a hydrocarbon gas such as methane or propane, or a rare gas such as helium or argon. Of these, nitrogen gas is most suitable because it is easily available and inexpensive, and has a large effect of suppressing the decomposition of low-pressure phase boron nitride at a high temperature of 2000 to 2200 ° C. However, ammonia gas or a mixed gas of ammonia and hydrocarbon is suitable only at a low temperature of 600 to 1000 ° C., and a high-purity low-pressure phase boron nitride containing a small amount of impurities such as carbon and oxygen should be produced. You can
【００２３】焼成炉としては、マッフル炉、管状炉、雰
囲気炉などのバッチ式炉や、ロータリーキルン、スクリ
ューコンベヤ炉、トンネル炉、ベルト炉、プッシャー
炉、竪型連続炉などの連続式炉が用いられる。これらは
目的に応じて使い分けられ、例えば多くの品種の低圧相
窒化ほう素を少量ずつ製造するときはバッチ式炉を、一
定の品種を多量製造するときは連続式炉が採用される。As the firing furnace, a batch type furnace such as a muffle furnace, a tubular furnace, an atmosphere furnace, or a continuous furnace such as a rotary kiln, a screw conveyor furnace, a tunnel furnace, a belt furnace, a pusher furnace, or a vertical continuous furnace is used. . These are properly used according to the purpose, and for example, a batch type furnace is used when a small number of low pressure phase boron nitrides of many kinds are manufactured, and a continuous furnace is used when a certain kind of a large quantity is manufactured.
【００２４】さらには、焼成時又は焼成後に低圧相窒化
ほう素の結晶性や粒径を調節するために触媒を添加する
こともできる。触媒としては、アルカリ金属又はアルカ
リ土類金属のほう酸塩、ほう酸および／または高温でほ
う酸と反応して塩を形成するアルカリ金属又はアルカリ
土類金属の炭酸塩等の化合物などが使用される。Further, a catalyst may be added to control the crystallinity and grain size of the low-pressure phase boron nitride during or after firing. As the catalyst, a borate of an alkali metal or an alkaline earth metal, a compound such as boric acid and / or a carbonate of an alkali metal or an alkaline earth metal which reacts with boric acid at a high temperature to form a salt is used.
【００２５】以上のようにして製造された低圧相窒化ほ
う素粉末は、必要に応じて粉砕、分級、酸処理による残
留触媒の除去（精製）、洗浄、乾燥などの後処理工程を
経た後、実用に供される。The low-pressure phase boron nitride powder produced as described above is subjected to post-treatment steps such as crushing, classification, acid treatment to remove (purify) residual catalyst, washing, and drying, if necessary. It is put to practical use.
【００２６】[0026]
【実施例】以下、実施例、比較例、参考例をあげてさら
に具体的に本発明を説明する。EXAMPLES The present invention will be described more specifically with reference to Examples, Comparative Examples and Reference Examples.
【００２７】実施例１ オルトほう酸５００ｇとメラミン５００ｇ（Ｂ／Ｎ原子
比が１／３）をボールミルで混合し、それを恒温恒湿機
を用い、大気中で温度８０℃、相対湿度８０％の雰囲気
下に１０時間保持した。得られた試料は指で軽く押さえ
ると容易に解砕できる程度に凝固していた。解砕後Ｘ線
回折測定によりほう酸メラミンが生成していることが確
認された。この試料にほう酸カルシウム（２ＣａＯ・Ｂ
2 Ｏ3 ）１２ｇを添加してボールミルで混合し、高周波
加熱炉を用いて窒素雰囲気下、温度２０００℃で２時間
焼成した。Example 1 500 g of orthoboric acid and 500 g of melamine (B / N atomic ratio of 1/3) were mixed in a ball mill, and the mixture was heated in the atmosphere at a temperature of 80 ° C. and a relative humidity of 80% using a thermo-hygrostat. It was kept in the atmosphere for 10 hours. The obtained sample was coagulated to such an extent that it could be easily crushed when lightly pressed with a finger. After crushing, it was confirmed by X-ray diffraction measurement that melamine borate was produced. Calcium borate (2CaO ・ B
2 O 3 ) (12 g) was added and mixed in a ball mill, and fired at a temperature of 2000 ° C. for 2 hours in a nitrogen atmosphere using a high frequency heating furnace.
【００２８】得られた焼成物を希硝酸で洗浄後、濾過、
乾燥の後処理を行ってからＸ線回折分析をしたところ、
六方晶窒化ほう素（ｈＢＮ）であることが確認された。The obtained fired product was washed with dilute nitric acid, filtered,
After dry post-treatment, X-ray diffraction analysis showed that
It was confirmed to be hexagonal boron nitride (hBN).
【００２９】さらに、得られた焼成物を酸処理を行わな
いで直径２０ｍｍ、高さ１０ｍｍの円柱状成形体を１０
個作製し、３０００ｋｇ／ｃｍ2 の圧力で冷間静水圧加
圧を行った後、窒素雰囲気下、温度２０００℃で２時間
焼成して１０個のｈＢＮ焼結体を製造した。これらの焼
結体の嵩密度を測定したところ、平均値（ｍ）１．８４
ｇ／ｃｍ3 、標準偏差（σ）０．０４６７ｇ／ｃｍ3 で
あり、変動係数（σ／ｍ）は０．０２５４であった。こ
の変動係数が小さいほど１０個のｈＢＮ焼結体の嵩密度
が均一であることを示すものである。以上の製造条件及
び結果をまとめて表１、表２に示す。Further, the obtained fired product was subjected to no acid treatment to obtain a cylindrical molded body having a diameter of 20 mm and a height of 10 mm.
Individual pieces were produced, subjected to cold isostatic pressing at a pressure of 3000 kg / cm 2 , and then fired at a temperature of 2000 ° C. for 2 hours in a nitrogen atmosphere to produce 10 hBN sintered bodies. When the bulk density of these sintered bodies was measured, the average value (m) was 1.84.
g / cm 3, the standard deviation (σ) 0.0467g / cm 3, the coefficient of variation (σ / m) was 0.0254. The smaller the coefficient of variation, the more uniform the bulk density of 10 hBN sintered bodies. The above manufacturing conditions and results are summarized in Tables 1 and 2.
【００３０】実施例２〜３ メタほう酸又は無水ほう酸とメラミンとを表１に示す条
件で混合し、それを表１に示す雰囲気下で保持してほう
酸メラミンを形成させ、表２に示す条件で焼成した。得
られた生成物をＸ線回折測定により測定したところ、い
ずれも非晶質窒化ほう素（ａ−ＢＮ）であることが確認
された。また、実施例１と同様にして焼結体の嵩密度を
測定した。Examples 2 to 3 Metaboric acid or boric anhydride and melamine were mixed under the conditions shown in Table 1 and held under the atmosphere shown in Table 1 to form melamine borate. Baked. When the obtained products were measured by X-ray diffraction measurement, it was confirmed that they were all amorphous boron nitride (a-BN). Further, the bulk density of the sintered body was measured in the same manner as in Example 1.
【００３１】実施例４〜５ オルトほう酸、メラミン、ほう酸カルシウム（ＣａＯ・
Ｂ2 Ｏ3 ）、炭酸カルシウム（ＣａＣＯ3 ）を表１に示
す条件で混合しそれを表１に示す雰囲気下で保持したと
ころ、実施例４についてはＸ線回折ではＣａＯ・Ｂ2 Ｏ
3 以外の成分は確認できなかったが、ＴＧ／ＤＴＡ曲線
が図１と同等であることよりほう酸メラミンであること
が確認された。また、実施例５についてはＣａＣＯ3 と
ほう酸メラミンの混合物であることがＸ線回折により確
認された。Examples 4 to 5 Orthoboric acid, melamine, calcium borate (CaO.
B 2 O 3 ) and calcium carbonate (CaCO 3 ) were mixed under the conditions shown in Table 1 and held under the atmosphere shown in Table 1. For Example 4, X-ray diffraction revealed that CaO.B 2 O
Components other than 3 were not confirmed, but it was confirmed to be melamine borate because the TG / DTA curve was the same as in FIG. Further, it was confirmed by X-ray diffraction that Example 5 was a mixture of CaCO 3 and melamine borate.
【００３２】得られたほう酸メラミンを表２に示す条件
で焼成しＸ線回折分析をしたところ、実施例４はｈＢＮ
とＣａＯ・Ｂ2 Ｏ3 の混合物であり、実施例５はａ−Ｂ
ＮとＣａＯ・Ｂ2 Ｏ3 の混合物であることが確認され
た。また、実施例１と同様にして焼結体の嵩密度を測定
した。The obtained melamine borate was calcined under the conditions shown in Table 2 and subjected to X-ray diffraction analysis.
And CaO.B 2 O 3 in a mixture of Example 5 and a-B
It was confirmed to be a mixture of N and CaO.B 2 O 3 . Further, the bulk density of the sintered body was measured in the same manner as in Example 1.
【００３３】比較例１〜２ 実施例１又は実施例３において、ほう酸とメラミンとの
混合物の保持条件を表１に示す雰囲気で行ったこと以外
は同様にして実験を行った。その結果、ほう酸メラミン
の生成が不完全であることがＸ線回折分析又はＴＧ／Ｄ
ＴＡ曲線により確認された。このものを表２に示す条件
で焼成し実施例１と同様に処理して後処理を行ったとこ
ろ、生成物はｈＢＮであることがＸ線回折分析により確
認された。また、実施例１と同様にして焼結体の嵩密度
を測定した。Comparative Examples 1 and 2 Experiments were carried out in the same manner as in Example 1 or Example 3, except that the condition for holding the mixture of boric acid and melamine was the atmosphere shown in Table 1. As a result, incomplete formation of melamine borate was confirmed by X-ray diffraction analysis or TG / D.
Confirmed by TA curve. When this product was fired under the conditions shown in Table 2 and treated in the same manner as in Example 1 to carry out post-treatment, it was confirmed by X-ray diffraction analysis that the product was hBN. Further, the bulk density of the sintered body was measured in the same manner as in Example 1.
【００３４】比較例３ オルトほう酸９２５ｇとメラミン１２５０ｇ（Ｂ／Ｎ原
子比が１／４）と水１２５ｇをヘンシェルミキサーで２
０分間撹拌した後、その一部を乾燥してＸ線回折分析を
行ったところ、ほう酸メラミンが生成していることが確
認された。残りの大部分の試料は乾燥せずにそのままほ
う酸カルシウム（２ＣａＯ・Ｂ2 Ｏ3 ）２０ｇを添加し
てボールミルで混合し、黒鉛抵抗加熱炉を用いて表２に
示す条件で焼成した。得られた焼成物を実施例１と同様
にして後処理を行いＸ線回折分析を行ったところ、ｈＢ
Ｎであることが確認された。また、実施例１と同様にし
て焼結体の嵩密度を測定した。Comparative Example 3 925 g of orthoboric acid, 1250 g of melamine (B / N atomic ratio is 1/4) and 125 g of water were mixed with a Henschel mixer 2 times.
After stirring for 0 minutes, a part of it was dried and subjected to X-ray diffraction analysis. As a result, it was confirmed that melamine borate was produced. Most of the remaining samples were not dried, and 20 g of calcium borate (2CaO.B 2 O 3 ) was added as it was, mixed in a ball mill, and fired using a graphite resistance heating furnace under the conditions shown in Table 2. The obtained fired product was post-treated in the same manner as in Example 1 and subjected to X-ray diffraction analysis.
It was confirmed to be N. Further, the bulk density of the sintered body was measured in the same manner as in Example 1.
【００３５】参考例１〜２ 市販の低圧相窒化ほう素粉末の２種類（市販品Ａ及び市
販品Ｂ）に５重量％のほう酸カルシウム（ＣａＯ・Ｂ2
Ｏ3 ）を添加混合し、その混合粉末を用いて実施例１と
同様にして焼結体を製造し嵩密度を測定した。Reference Examples 1-2 Two types of commercially available low-pressure phase boron nitride powder (commercial product A and commercial product B) were added to 5% by weight of calcium borate (CaO.B 2).
O 3 ) was added and mixed, and the mixed powder was used to manufacture a sintered body in the same manner as in Example 1, and the bulk density was measured.
【００３６】[0036]
【表１】 [Table 1]
【００３７】[0037]
【表２】 [Table 2]
【００３８】[0038]
【発明の効果】本発明によれば、均質な低圧相窒化ほう
素粉末を高収率で、しかも濾過、遠心分離、乾燥などの
余分な工程を必要とせずに高い生産性で製造することが
できる。According to the present invention, a homogeneous low-pressure phase boron nitride powder can be produced in high yield with high productivity without requiring extra steps such as filtration, centrifugation and drying. it can.
【図１】ほう酸メラミンのＴＧ／ＤＴＡ曲線図。FIG. 1 is a TG / DTA curve diagram of melamine borate.
【図２】ほう酸とメラミンとの混合物のＴＧ／ＤＴＡ曲
線図。FIG. 2 is a TG / DTA curve diagram of a mixture of boric acid and melamine.
Claims (1)
／１〜１／６となる割合で混合し、これを温度０〜２０
０℃、相対湿度５％以上の水蒸気を含む雰囲気下で保持
してほう酸メラミンを形成させた後、非酸化性ガス雰囲
気下、温度６００〜２２００℃で焼成することを特徴と
する低圧相窒化ほう素粉末の製造方法。1. Boric acid and melamine having a B / N atomic ratio of 1
Mix at a ratio of 1/1 to 1/6, and mix this at a temperature of 0 to 20.
A low-pressure phase nitriding method characterized in that after melamine borate is formed by holding it in an atmosphere containing water vapor at 0 ° C. and a relative humidity of 5% or more, it is fired at a temperature of 600 to 2200 ° C. in a non-oxidizing gas atmosphere. Method for producing elementary powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08804395A JP3397503B2 (en) | 1995-04-13 | 1995-04-13 | Method for producing low pressure phase boron nitride powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08804395A JP3397503B2 (en) | 1995-04-13 | 1995-04-13 | Method for producing low pressure phase boron nitride powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08283008A true JPH08283008A (en) | 1996-10-29 |
| JP3397503B2 JP3397503B2 (en) | 2003-04-14 |
Family
ID=13931808
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08804395A Expired - Fee Related JP3397503B2 (en) | 1995-04-13 | 1995-04-13 | Method for producing low pressure phase boron nitride powder |
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| Country | Link |
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| JP (1) | JP3397503B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009149469A (en) * | 2007-12-20 | 2009-07-09 | Denki Kagaku Kogyo Kk | Method for producing hexagonal boron nitride |
| CN115925428A (en) * | 2023-01-06 | 2023-04-07 | 灵石鸿润和新材料有限公司 | Hexagonal boron nitride powder and preparation method and application thereof |
-
1995
- 1995-04-13 JP JP08804395A patent/JP3397503B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009149469A (en) * | 2007-12-20 | 2009-07-09 | Denki Kagaku Kogyo Kk | Method for producing hexagonal boron nitride |
| CN115925428A (en) * | 2023-01-06 | 2023-04-07 | 灵石鸿润和新材料有限公司 | Hexagonal boron nitride powder and preparation method and application thereof |
| CN115925428B (en) * | 2023-01-06 | 2023-10-27 | 灵石鸿润和新材料有限公司 | Hexagonal boron nitride powder and preparation method and application thereof |
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| Publication number | Publication date |
|---|---|
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