JPH10291809A - Production method of boron nitride - Google Patents
Production method of boron nitrideInfo
- Publication number
- JPH10291809A JPH10291809A JP10207797A JP10207797A JPH10291809A JP H10291809 A JPH10291809 A JP H10291809A JP 10207797 A JP10207797 A JP 10207797A JP 10207797 A JP10207797 A JP 10207797A JP H10291809 A JPH10291809 A JP H10291809A
- Authority
- JP
- Japan
- Prior art keywords
- container
- lid
- boron nitride
- silicon dioxide
- boron
- 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.)
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Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は窒化ホウ素の製造法
に関する。The present invention relates to a method for producing boron nitride.
【０００２】[0002]
【従来の技術】窒化ホウ素は耐熱性、化学的安定性、潤
滑特性に優れ、更に中性子吸収作用も有するので、耐熱
耐食性材料等の各種高温構造材料、電気絶縁材、電気回
路部品、高温用潤滑剤、離型剤、中性子遮蔽材のフィラ
ー等多くの用途があり、今後更に種々の用途への発展が
期待される材料である。2. Description of the Related Art Boron nitride has excellent heat resistance, chemical stability and lubricating properties, and also has a neutron absorbing effect. Therefore, various high-temperature structural materials such as heat-resistant and corrosion-resistant materials, electric insulating materials, electric circuit parts, lubricating materials for high temperatures. There are many uses such as an agent, a release agent, and a filler for a neutron shielding material, and it is a material that is expected to further develop into various uses in the future.
【０００３】窒化ホウ素は工業的にはホウ酸、無水ホ
ウ酸、あるいはホウ砂、ホウ酸アンモニウム等のホウ酸
塩類等をアンモニアガスまたは窒素ガス雰囲気中で加熱
することによりホウ素を窒化させるか、あるいは、こ
れらのホウ素化合物とメラミン、尿素、グアニジン等の
含窒素化合物とを混合した後、この混合物をアンモニ
ア、窒素、アルゴン、ヘリウム等の還元性ガスまたは不
活性ないし非酸化性ガス雰囲気中で加熱することによ
り、ホウ素を窒化させる方法で製造されている（特開昭
４７−２７２００号公報、特開昭６０−１５１２０２号
公報、特開昭６０−１５５５０７号公報、特開昭６１−
６３５０５号公報、特開昭６１−１９１５０５号公報、
特開昭６１−２８６２０７号公報、特開昭６１−２９５
２１１号公報、特開昭６２−５９５０６号公報等）。[0003] Boron nitride is industrially nitrided by heating boric acid, boric anhydride, or borate such as borax or ammonium borate in an ammonia gas or nitrogen gas atmosphere, or After mixing these boron compounds with nitrogen-containing compounds such as melamine, urea and guanidine, the mixture is heated in an atmosphere of a reducing gas such as ammonia, nitrogen, argon, helium or an inert or non-oxidizing gas. Thus, it is manufactured by a method of nitriding boron (JP-A-47-27200, JP-A-60-151202, JP-A-60-155507, and JP-A-61-155507).
JP-A-63505, JP-A-61-191505,
JP-A-61-286207, JP-A-61-295
211, JP-A-62-59506, etc.).
【０００４】[0004]
【発明が解決しようとする課題】上記した製造法によ
り、安価でかつ大量に高純度の窒化ホウ素を製造するこ
とが可能となったが、従来耐熱性の蓋付き容器の内面に
塗布した窒化ホウ素が多数回使用するうちに、容器との
膨張率の差で剥がれ落ち蓋と容器の境目にガラス質のも
のが不均一に生成し、容器と蓋の密着性が悪くなり収率
の低下を引き起こし、発生したナトリウムが容器を劣化
し使用できなくなる等の問題が発生した。According to the above-mentioned production method, it has become possible to produce high-purity boron nitride inexpensively and in large quantities. During many uses, it peels off due to the difference in expansion coefficient between the container and the glass, and the glassy material is generated unevenly at the boundary between the lid and the container, and the adhesion between the container and the lid deteriorates, causing a decrease in yield. In addition, the generated sodium deteriorates the container and becomes unusable.
【０００５】[0005]
【課題を解決するための手段】本発明ではこれらの問題
を解決するため内面に塗布する窒化ホウ素に替わり、二
酸化珪素を用いることにより、上記した問題点の解決を
見出した。In order to solve these problems, the present invention has found that the above-mentioned problems have been solved by using silicon dioxide instead of boron nitride applied to the inner surface.
【０００６】即ち、本発明はホウ酸類、無水ホウ酸及び
ホウ酸塩類から選ばれた１種以上のホウ素化合物とＮＨ
２基を有する有機化合物との混合物を耐熱性の蓋付き容
器に入れ、蓋付き容器を加熱する窒化ホウ素の製造法に
おいて、該耐熱性の蓋付き容器の内面が二酸化珪素で被
覆されていることを特徴とする窒化ホウ素の製造法に関
する。That is, the present invention relates to one or more boron compounds selected from boric acids, boric anhydrides and borates, and NH.
A method for producing a boron nitride in which a mixture with an organic compound having two groups is placed in a heat-resistant container and the container is heated, wherein the inner surface of the heat-resistant container is coated with silicon dioxide. And a method for producing boron nitride.
【０００７】[0007]
【発明の実施の形態】本発明を更に詳細に説明する。本
発明において用いるホウ素化合物としては、ホウ酸類、
無水ホウ酸（Ｂ２Ｏ ３）及びホウ酸塩類のホウ素化合物
から選ばれる。この内ホウ酸類としてはオルソホウ酸、
メタホウ酸、テトラホウ酸等を挙げることができる。ま
たホウ酸塩類としては、これらホウ酸類のアンモニウム
塩、ナトリウム塩、カリウム塩、マグネシウム塩、カル
シウム塩等が挙げられる。これらのホウ酸塩類は結晶水
の有無によって無水塩と含水塩とがある。本発明におい
てはその何れも使用可能ではあるものの、含水塩を使用
した場合は、蓋付き容器内でのＮＨ２基を有する有機化
合物との加熱反応時に内容物が発泡しやすいので、無水
塩の方が好ましい。DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in more detail. Book
As the boron compound used in the present invention, boric acids,
Boric anhydride (B2O 3) And boron compounds of borates
Selected from. Of these, orthoboric acid,
Examples thereof include metaboric acid and tetraboric acid. Ma
Borates include ammonium salts of these borates.
Salt, sodium salt, potassium salt, magnesium salt, cal
And the like. These borates are crystal water
There are an anhydrous salt and a hydrated salt depending on the presence or absence. In the present invention
Use hydrated salt, although any of them can be used
If so, the NH in the container with lid2Organizing with groups
Since the contents easily foam during the heating reaction with the compound,
Salt is preferred.
【０００８】尚、これらのホウ素化合物の品質は、特に
高純度である必要はなく、通常市販の工業薬品が好適に
使用されるが、ＮＨ２基を有する有機化合物と混合され
た際の均一混合性を良好ならしめるため、粉末状のもの
が好ましいが特に微細化する必要もない。[0008] The quality of these boron compounds does not need to be particularly high, and usually, commercially available industrial chemicals are preferably used. However, when the boron compounds are mixed with an organic compound having an NH 2 group, they are mixed uniformly. In order to improve the properties, a powdery material is preferable, but it is not particularly necessary to make it finer.
【０００９】ＮＨ２基を有する有機化合物としては、尿
素、メラミン、メロン、メレム、メラム、ジシアンジア
ミド、アンメリド、アセトグアナミン、塩酸グアニジ
ン、塩化メラミン等が挙げられる。これらのＮＨ２基を
有する有機化合物の品質も、ホウ素化合物の場合と同
様、粉末状の工業薬品が好適に使用される。Examples of the organic compound having an NH 2 group include urea, melamine, melon, melem, melam, dicyandiamide, ammelide, acetoguanamine, guanidine hydrochloride, melamine chloride and the like. As for the quality of these organic compounds having an NH 2 group, industrial chemicals in powder form are preferably used as in the case of the boron compounds.
【００１０】本発明では、ホウ素化合物とＮＨ２基を有
する有機化合物とを混合した後、この混合物を内面が二
酸化珪素で被覆されている耐熱性の蓋付き容器に入れ、
これを加熱し還元反応によりホウ素化合物中のホウ素原
子を窒化させて窒化ホウ素を生成させるものである。In the present invention, after mixing a boron compound and an organic compound having an NH 2 group, the mixture is placed in a heat-resistant container having an inner surface coated with silicon dioxide,
This is heated to cause a boron atom in the boron compound to be nitrided by a reduction reaction to generate boron nitride.
【００１１】窒化ホウ素（ＢＮ）はその分子式が示す通
りＮ／Ｂ原子比は１．０である。従って、上記ホウ素化
合物とＮＨ２基を有する有機化合物の混合割合は、理論
上はＮ／Ｂ原子比として１．０で良いはずであるが、本
発明においてはＮ／Ｂ原子比は１．０以下でも窒化ホウ
素を得ることはできる。しかしこの場合は窒化ホウ素の
収率が低下するので好ましくない。[0011] Boron nitride (BN) has an N / B atomic ratio of 1.0 as shown by its molecular formula. Therefore, the mixing ratio of the boron compound and the organic compound having an NH 2 group should theoretically be 1.0 as the N / B atomic ratio, but in the present invention, the N / B atomic ratio is 1.0. Even below, boron nitride can be obtained. However, this case is not preferable because the yield of boron nitride decreases.
【００１２】本発明での窒化ホウ素の製造法は、上記の
通りＮＨ２基を有する有機化合物を使用しホウ素化合物
中のホウ素原子を還元反応により窒化させる方法である
ので、ホウ素化合物とＮＨ２基を有する有機化合物の混
合割合は、通常窒素過剰、すなわちＮ／Ｂ原子比として
１．０以上で実施するのが好ましい。しかし、必要以上
の窒素過剰はその分ＮＨ２基を有する有機化合物の損失
を招くのみであるので、本発明ではＮ／Ｂ原子比は通常
１．０〜４．０、より好ましくは１．５〜３．０で実施
するのが好適である。[0012] preparation of boron nitride in the present invention, since it is a method of nitriding by a reduction reaction of boron atoms of the boron compound is an organic compound having as NH 2 groups of the boron compound and the NH 2 group The mixing ratio of the organic compound having the general formula (I) is preferably nitrogen excess, that is, the N / B atomic ratio is preferably 1.0 or more. However, an excessive nitrogen excess only causes a loss of the organic compound having an NH 2 group, and therefore, in the present invention, the N / B atomic ratio is usually 1.0 to 4.0, more preferably 1.5. It is preferred to carry out at ~ 3.0.
【００１３】本発明では前述の通り内面が二酸化珪素で
被覆されている耐熱性の蓋付き容器を必要とするが、本
発明における上記還元反応は６００〜１６００℃で実施
されるので、蓋付き容器はこの温度に耐えうる材質が要
求される。かかる性能を備えた蓋付き容器としては、ア
ルミナ、チタニア、ジルコニア、シリカ、マグネシア、
カルシア及びシリカ、アルミナを主成分とするコージエ
ライト、ムライト等の各種セラミックス焼結体が好適で
ある。In the present invention, as described above, a heat-resistant container having an inner surface coated with silicon dioxide is required. However, since the above-mentioned reduction reaction in the present invention is carried out at 600 to 1600 ° C., the container with the lid is required. Requires a material that can withstand this temperature. As a container with a lid having such performance, alumina, titania, zirconia, silica, magnesia,
Various ceramic sintered bodies such as cordierite, mullite, and the like containing calcia, silica, and alumina as main components are suitable.
【００１４】前記の蓋付き容器の内面を二酸化珪素で被
覆するには、二酸化珪素粉末を分散させた分散液を容器
内面や蓋の内面にハケにて塗布、もしくは吹き付ける方
法があり、その後乾燥させて用いれば良い。被覆に用い
る二酸化珪素の一次粒子の比表面積は０．１ｍ２／ｇ以
上が好ましく、更に好ましくは１ｍ２／ｇ以上が好適で
ある。比表面積が０．１ｍ２／ｇ未満では塗布むらがで
き、せっかく塗布した二酸化珪素が剥がれやすくなるの
で好ましくない。In order to coat the inner surface of the above-mentioned container with a lid with silicon dioxide, there is a method in which a dispersion liquid in which silicon dioxide powder is dispersed is applied or sprayed on the inner surface of the container or the inner surface of the lid, and then dried. And use it. The specific surface area of the primary particles of silicon dioxide used for coating is preferably 0.1 m 2 / g or more, more preferably 1 m 2 / g or more. When the specific surface area is less than 0.1 m 2 / g, coating unevenness occurs, and the applied silicon dioxide tends to peel off, which is not preferable.
【００１５】二酸化珪素粉末を分散させる分散剤として
は、アニオン系のポリカルボン酸塩（ジカルボン酸アン
モニウム塩、トリカルボン酸アンモニウム塩等）及びカ
チオン系の第４アンモニウム塩型（アルキルトリメチル
アンモニウム塩、ジアルキルジメチルアンモニウム塩、
アルキルジメチルベンジルアンモニウム塩等）の使用が
可能であるが、ポリカルボン酸塩はカルボキシル基が多
くなるほど解離が悪くなり分散剤としての効果が劣るの
で好ましくない。As dispersants for dispersing the silicon dioxide powder, anionic polycarboxylates (ammonium dicarboxylate, ammonium tricarboxylate, etc.) and cationic quaternary ammonium salts (alkyltrimethylammonium salt, dialkyldimethyl Ammonium salts,
Alkyl dimethyl benzyl ammonium salts and the like can be used, but polycarboxylates are not preferable because the dissociation becomes worse as the number of carboxyl groups increases and the effect as a dispersant is poor.
【００１６】分散剤を用いない場合は、分散ムラができ
二酸化珪素の均一スラリーを調合するのが困難となり好
ましくない。被覆するに当たっては特に厚く被覆する必
要はなく生地面が見えない程度で十分に効果がある。ま
た、蓋付容器の外面を被覆する必要はないが蓋と容器の
境目の、後述の発生したガスが通過する容器上部の蓋と
接する面及び蓋の容器と接する面は十分に被覆する必要
がある。When a dispersant is not used, dispersion unevenness occurs, and it is difficult to prepare a uniform slurry of silicon dioxide, which is not preferable. When coating, it is not necessary to apply a particularly thick coating, and the effect is sufficiently high as long as the fabric surface is not visible. It is not necessary to cover the outer surface of the lidded container, but it is necessary to sufficiently cover the boundary between the lid and the container, that is, the surface in contact with the upper lid of the container through which generated gas described below passes and the surface of the lid that contacts the container. is there.
【００１７】本発明においては、ホウ素化合物とＮＨ２
基を有する有機化合物の混合物を加熱すると、窒化ホウ
素を生成すると共に各種ガスを発生する。例えば、ホウ
酸ナトリウムと尿素の混合物を加熱した場合、下記
（１）式が示す如く酸化ナトリウム、炭酸ガス、水蒸気
を発生する。 Ｎａ２Ｂ４Ｏ７＋２（ＮＨ２）２ＣＯ→ ４ＢＮ＋Ｎａ２Ｏ＋２ＣＯ２＋４Ｈ２Ｏ ・・・ （１）In the present invention, a boron compound and NH 2
When a mixture of organic compounds having a group is heated, boron nitride is generated and various gases are generated. For example, when a mixture of sodium borate and urea is heated, sodium oxide, carbon dioxide, and water vapor are generated as shown by the following equation (1). Na 2 B 4 O 7 +2 (NH 2 ) 2 CO → 4BN + Na 2 O + 2CO 2 + 4H 2 O (1)
【００１８】また、ＮＨ２基を有する有機化合物が過剰
の場合は、過剰のＮＨ２基を有する有機化合物も熱分解
して各種ガスを発生する。しかして、本発明ではホウ素
化合物とＮＨ２基を有する有機化合物との混合物は蓋付
き容器内で加熱されるので、この加熱によって発生した
ガスは蓋付き容器内をさほど加圧にすることなく自動的
に蓋付き容器外に流出し、かつ後述するプロパンなどの
燃焼ガスが蓋付き容器内に流入しないような形状の容器
でなければならない。If the organic compound having an NH 2 group is excessive, the organic compound having an excessive NH 2 group is also thermally decomposed to generate various gases. However, in the present invention, the mixture of the boron compound and the organic compound having an NH 2 group is heated in the container with a lid, and the gas generated by this heating is automatically applied without increasing the pressure in the container with the lid. The container must be shaped so that the combustion gas, such as propane, described below, flows out of the container with a lid and does not flow into the container with the lid.
【００１９】従って、蓋付き容器にあっては蓋は容器本
体にのせて置く形状のものが好ましく、蓋はその自重に
より容器を密閉し、しかも容器内に発生したガスは容器
内をさほど加圧にすることなく、その圧力により蓋を僅
かに上方に持ち上げそのガスが容器外へ排出される程度
の重量である必要がある。また、容器上部の蓋と接する
面及び蓋の容器と接する面は、蓋を容器にのせ置いた場
合に密接するような面である必要がある。更に、容器の
形状は底付きの円筒形とか重箱の如き方形等任意の形状
から選択される。しかし、容器は加熱・冷却を繰返す状
態で使用されるので、この加熱・冷却による歪の発生が
もたらす容器の破損を極力防止するために、容器の形状
は円筒形が好ましい。かかる形状の容器としては例えば
図１〜図４に示す形状のものが挙げられるが、必ずしも
これらに限定されるものではない。尚、図４に示すよう
な形状のものが前記容器の歪による破損を更に防止でき
るので好ましい。Therefore, in a container with a lid, it is preferable that the lid is placed on the container body, and the lid seals the container by its own weight, and the gas generated in the container is pressurized in the container. The pressure must lift the lid slightly upward due to the pressure, and the weight must be such that the gas is discharged out of the container. Also, the surface of the upper part of the container that contacts the lid and the surface of the lid that contacts the container need to be surfaces that are in close contact when the lid is placed on the container. Further, the shape of the container is selected from an arbitrary shape such as a cylindrical shape with a bottom or a rectangular shape such as a heavy box. However, since the container is used in a state where heating and cooling are repeated, the shape of the container is preferably cylindrical in order to minimize damage to the container caused by distortion caused by the heating and cooling. Examples of the container having such a shape include those having the shapes shown in FIGS. 1 to 4, but are not necessarily limited thereto. The shape shown in FIG. 4 is preferable because breakage due to distortion of the container can be further prevented.
【００２０】本発明は不活性ガスまたは還元性ガスを流
通させることなく、蓋付き容器を加熱することによって
窒化ホウ素を製造する方法であり、好ましくは蓋付き容
器の周囲は酸化性ガス雰囲気である。かかる加熱方法
は、例えば炉を使用し、この炉内に均一混合されたホウ
素化合物とＮＨ２基を有する有機化合物の入った耐熱性
の蓋付き容器を挿入した状態で、炉内に熱風を送入する
ことで簡単に実施することができる。かかる熱風は、プ
ロパン、ブタン、灯油、重油等の燃料を空気で燃焼させ
ることで簡単に得ることができる。更に、この燃焼を空
気過剰で行なえば、蓋付き容器の周囲は自ずと酸化性ガ
ス雰囲気とすることができる。本発明はこのような方法
で蓋付き容器を加熱することができるので、加熱装置は
極めて簡単で、かつ大型化が容易であり、しかも燃料が
低廉なためエネルギーコストが低く、かつ熱効率も良
い。The present invention is a method for producing boron nitride by heating a lidded container without flowing an inert gas or a reducing gas. Preferably, the periphery of the lidded container is an oxidizing gas atmosphere. . In this heating method, for example, a furnace is used, and hot air is blown into the furnace in a state where a heat-resistant lidded container containing a boron compound and an organic compound having an NH 2 group mixed uniformly is inserted into the furnace. It can be easily implemented by inserting. Such hot air can be easily obtained by burning a fuel such as propane, butane, kerosene, or heavy oil with air. Furthermore, if this combustion is performed with excess air, the surroundings of the container with the lid can be naturally set to an oxidizing gas atmosphere. According to the present invention, since the container with the lid can be heated by such a method, the heating device is extremely simple and can be easily increased in size, and the fuel cost is low, so that the energy cost is low and the heat efficiency is good.
【００２１】更に、加熱炉が水平式のトンネル炉等の形
式のものであれば、蓋付き容器は炉内を水平に移動する
ので連続的に窒化ホウ素を製造することが可能である。
そして上記記載の通り蓋付き容器の周囲は、容易に酸化
性ガス雰囲気とすることができるので、ホウ素化合物と
ＮＨ２基を有する有機化合物との反応及び過剰のＮＨ２
基を有する有機化合物の分解によって生成した有害ガス
は、蓋付き容器外に排出され燃焼無害化されるので排ガ
スの処理も必要としない。Further, if the heating furnace is of a type such as a horizontal tunnel furnace, the container with the lid moves horizontally in the furnace, so that it is possible to continuously produce boron nitride.
As described above, the surroundings of the container with the lid can be easily made to have an oxidizing gas atmosphere, so that the reaction between the boron compound and the organic compound having an NH 2 group and the excess NH 2
The harmful gas generated by the decomposition of the organic compound having a group is discharged to the outside of the lidded container and made harmless by burning, so that no treatment of exhaust gas is required.
【００２２】本発明ではホウ素化合物とＮＨ２基を有す
る有機化合物との混合物の加熱は６００〜１６００℃、
好ましくは８００〜１３００℃の温度で実施される。加
熱温度が６００℃未満では窒化ホウ素の生成反応が遅く
不都合であり、１６００℃を越える温度では単なる熱エ
ネルギの損失であるばかりでなく、装置の耐熱性も配慮
する必要があるので好ましくない。上記加熱において、
その加熱時間は容器の形状、容積等によって異なるが、
通常１〜１０時間が好ましい。かくして得られた窒化ホ
ウ素は、冷却後例えば特開昭６１−６３５０５号公報記
載の方法の如く、希塩酸、希硫酸等の希鉱酸で洗浄後水
洗することにより、容易に高純度とすることができるの
である。In the present invention, the mixture of the boron compound and the organic compound having an NH 2 group is heated at 600 to 1600 ° C.
It is preferably carried out at a temperature of 800 to 1300 ° C. If the heating temperature is lower than 600 ° C., the formation reaction of boron nitride is slow and inconvenient. If the heating temperature is higher than 1600 ° C., not only loss of thermal energy but also heat resistance of the apparatus needs to be considered, which is not preferable. In the above heating,
The heating time varies depending on the shape, volume, etc. of the container,
Usually, 1 to 10 hours is preferable. The thus-obtained boron nitride can be easily purified to a high purity by cooling and then washing with a dilute mineral acid such as dilute hydrochloric acid or dilute sulfuric acid, followed by washing with water, for example, as described in JP-A-61-63505. You can.
【００２３】本発明の方法に従えば、ホウ素化合物とＮ
Ｈ２基を有する有機化合物との混合物の加熱は、従来公
知の方法の如く還元性ガスまたは不活性ガスないし非酸
化性ガスの雰囲気下で行なう必要はなく、更に従来の方
法では不可能であった、酸化性ガス雰囲気下でも耐熱性
の蓋付き容器にガラス質のものの生成による種々の問題
を起こすこと無く好適に実施することができる。According to the method of the present invention, the boron compound and N
The heating of the mixture with the organic compound having an H 2 group does not need to be performed in an atmosphere of a reducing gas or an inert gas or a non-oxidizing gas as in a conventionally known method, and cannot be performed by a conventional method. Further, even in an oxidizing gas atmosphere, the present invention can be suitably carried out without causing various problems due to the formation of a vitreous material in a heat-resistant lidded container.
【００２４】[0024]
【実施例】以下、実施例により本発明を更に具体的に説
明する。尚、実施例において部及び％は特記する以外は
重量基準を表わす。 実施例１ 比表面積１０ｍ２／ｇの二酸化珪素を、０．０１％ポリ
カルボン酸アンモニウム塩アニオン水溶液に添加し、ミ
キサーで混合し二酸化珪素含量が１５％のスラリーを調
製した。このスラリーをスプレーガンを用いて図１に示
す形状の内容積１Ｌのアルミナ質ルツボの内面、蓋の内
面、容器上部の蓋と接する面及び蓋の容器と接する面に
均一に吹き付け、その後乾燥し充填用の容器とした。次
にホウ素化合物として粉末状無水ホウ砂２０１ｇとＮＨ
２基を有する有機化合物として粉末状尿素３６０ｇをよ
く混合し（Ｎ／Ｂ原子比＝３．０）、この混合物を上述
の内面を二酸化珪素で被覆したルツボに入れ、ルツボを
プロパンバーナー付き燃焼炉中に静置した。しかる後プ
ロパンを燃焼させ炉内を徐々に昇温後、上記ルツボを約
１２００℃で４時間加熱した。加熱終了後ルツボを放冷
し粉末状の内容物を取り出した。内容物を取り出した後
のルツボにはガラス状の付着物は全く見られなかった。
次に、この粉末を上水及び５％硝酸水溶液で洗浄後、１
２０℃で４時間乾燥して９５ｇの粉末を得た。この粉末
をＸ線回折装置にて分析したところ、図５の如き回折線
図が得られ、窒化ホウ素であることが確認された。また
得られた窒化ホウ素を原子吸光分析装置で分析した結
果、ナトリウム、鉄、シリカ、カルシウムなどの不純物
は夫々０．１％以下であり、この粉末は高純度の窒化ホ
ウ素であった。尚、上記ルツボの加熱中に発生する尿素
の分解ガスは、炉内で焼却され、炉の排ガス中に有機物
は全く検出されなかった。また、ルツボの内面はガラス
状の膜が均一に付着していた。EXAMPLES The present invention will be described more specifically with reference to the following examples. In the examples, parts and% are by weight unless otherwise specified. Example 1 Silicon dioxide having a specific surface area of 10 m 2 / g was added to a 0.01% aqueous solution of an ammonium salt of a polycarboxylic acid ammonium salt and mixed with a mixer to prepare a slurry having a silicon dioxide content of 15%. This slurry was sprayed uniformly using a spray gun on the inner surface of a 1-L alumina crucible having the shape shown in FIG. 1, the inner surface of the lid, the upper surface of the container in contact with the lid, and the surface of the lid in contact with the container, and then dried. A container for filling was used. Next, 201 g of powdery anhydrous borax as a boron compound and NH
360 g of powdered urea as an organic compound having two groups are mixed well (N / B atomic ratio = 3.0), and this mixture is placed in a crucible whose inner surface is coated with silicon dioxide, and the crucible is burned with a propane burner. Let stand inside. Then, after propane was burned and the inside of the furnace was gradually heated, the crucible was heated at about 1200 ° C. for 4 hours. After the heating, the crucible was allowed to cool, and the powdery content was taken out. After removing the contents, no glassy deposits were observed on the crucible.
Next, this powder was washed with tap water and a 5% nitric acid aqueous solution,
After drying at 20 ° C. for 4 hours, 95 g of powder was obtained. When this powder was analyzed with an X-ray diffractometer, a diffraction diagram as shown in FIG. 5 was obtained, and it was confirmed that the powder was boron nitride. The obtained boron nitride was analyzed by an atomic absorption spectrometer. As a result, impurities such as sodium, iron, silica, and calcium were each 0.1% or less, and the powder was high-purity boron nitride. The decomposition gas of urea generated during the heating of the crucible was incinerated in the furnace, and no organic matter was detected in the exhaust gas of the furnace. Further, a glassy film was uniformly adhered to the inner surface of the crucible.
【００２５】実施例２ 実施例１と同様のルツボを用い、全く同じ操作を１０回
繰り返した。１０回実施後のルツボの内面には１度目に
付着したガラス状の膜が均一に付着したままで、付着物
の増加はみられず、収量も変化しなかった。Example 2 Using the same crucible as in Example 1, the same operation was repeated 10 times. After the ten times, the first glassy film adhered to the inner surface of the crucible was uniformly adhered, no increase in the adhered matter was observed, and the yield did not change.
【００２６】実施例３ 図２に示す形状の内容積２Ｌのコージエライト質ルツボ
を用いた他は、実施例１と同様にルツボの内面、蓋の内
面、容器上部の蓋と接する面及び蓋の容器と接する面に
均一に吹き付け、その後乾燥し充填用の容器とした。ホ
ウ素化合物として粉末状の無水ホウ砂４０２ｇとＮＨ２
基を有する有機化合物として粉末状のメラミン５０４ｇ
をよく混合し（Ｎ／Ｂ原子比＝３．０）、この混合物を
前述の内面を二酸化珪素で被覆した内容積２Ｌのコージ
エライト質ルツボに入れ、このルツボを台車に乗せた状
態で内部温度が約８００℃に保持されたブタン燃焼方式
トンネルキルンに該台車を送り込み、キルン内の滞留時
間が約４時間になるように台車速度を制御し、上記ルツ
ボを加熱した。トンネルキルンから取り出された台車上
のルツボは、実施例１と同様に放冷後粉末状の内容物を
取り出した。取り出した後のルツボにはガラス状の付着
物が均一に付着していた。次いで、この粉末を上水及び
３％硫酸水溶液で洗浄後、１２０℃で４時間乾燥して１
９４ｇの粉末を得た。この粉末をＸ線回折装置及び原子
吸光分析装置で分析したところ、実施例１と同様のナト
リウム、鉄、シリカ、カルシウム等の不純物が夫々０．
１％以下の高純度の窒化ホウ素を得た。尚、トンネルキ
ルンの排ガス中に有機物は全く検出されなかった。Example 3 The inner surface of the crucible, the inner surface of the lid, the surface in contact with the upper lid of the container, and the container of the lid were the same as in Example 1, except that a cordierite crucible having an inner volume of 2 L having the shape shown in FIG. 2 was used. Was uniformly sprayed on the surface in contact with the substrate, and then dried to form a container for filling. 402 g of powdered anhydrous borax and NH 2 as a boron compound
504 g of melamine in powder form as an organic compound having a group
Are mixed well (N / B atomic ratio = 3.0), and this mixture is put into a 2 L cordierite crucible whose inner surface is coated with silicon dioxide, and the internal temperature is lowered while the crucible is placed on a bogie. The truck was fed into a butane combustion tunnel kiln maintained at about 800 ° C., and the crucible was heated by controlling the speed of the truck so that the residence time in the kiln was about 4 hours. The crucible on the truck taken out of the tunnel kiln was allowed to cool as in Example 1, and then the powdery content was taken out. The glass-like deposit was uniformly adhered to the crucible after being taken out. Next, this powder was washed with tap water and a 3% aqueous sulfuric acid solution, and dried at 120 ° C. for 4 hours to obtain 1 powder.
94 g of powder were obtained. When this powder was analyzed with an X-ray diffractometer and an atomic absorption spectrometer, impurities such as sodium, iron, silica, and calcium, which were the same as in Example 1, were each 0.1%.
High-purity boron nitride of 1% or less was obtained. Incidentally, no organic matter was detected in the exhaust gas of the tunnel kiln.
【００２７】実施例４ 実施例３と同様のルツボを用い、全く同じ操作を１０回
繰り返した。１０回実施後のルツボの内面には１度目に
付着したガラス状の膜が均一に付着したままで、付着物
の増加はみられず、収量も変化しなかった。Example 4 Using the same crucible as in Example 3, the same operation was repeated 10 times. After the ten times, the first glassy film adhered to the inner surface of the crucible was uniformly adhered, no increase in the adhered matter was observed, and the yield did not change.
【００２８】比較例１ 実施例１の二酸化珪素を窒化ホウ素に変更した以外は、
実施例１と同様に行った。加熱終了後ルツボを放冷し粉
末状の内容物を取り出した。内容物を取り出した後のル
ツボの上端部には少量のガラス状の付着物が見られた。Comparative Example 1 Except that the silicon dioxide of Example 1 was changed to boron nitride,
Performed in the same manner as in Example 1. After the heating, the crucible was allowed to cool, and the powdery content was taken out. After the contents were taken out, a small amount of glass-like deposit was observed at the upper end of the crucible.
【００２９】比較例２ 比較例１のルツボを用い、実施例３と同様にしてトンネ
ルキルンで加熱を実施した。加熱終了後該ルツボを放冷
し粉末状の内容物を取り出した。内容物を取り出した後
のルツボの各部には不均一にガラス状の付着物が見られ
た。次に、このルツボを用いて１０回同様の加熱操作を
行った。１０回実施後のルツボ内にはガラス状の物は不
均一で多量に付着していた。また内容物も十分には取り
出せず、取り出した粉末を上水及び５％硝酸水溶液で洗
浄、１２０℃で４時間乾燥した後９０ｇの粉末しか得る
ことが出来なかった（実施例３に比較し収量が９５％に
低下した）。Comparative Example 2 Using the crucible of Comparative Example 1, heating was performed in a tunnel kiln in the same manner as in Example 3. After the heating, the crucible was allowed to cool and the powdery content was taken out. After the contents were taken out, non-uniform glass-like deposits were observed in each part of the crucible. Next, the same heating operation was performed 10 times using this crucible. After ten times, the glass-like material was uneven and adhered in a large amount in the crucible. Further, the contents were not sufficiently taken out, and the taken-out powder was washed with tap water and a 5% nitric acid aqueous solution and dried at 120 ° C. for 4 hours, so that only 90 g of powder could be obtained (compared with Example 3). Decreased to 95%).
【００３０】比較例３ 比表面積１０ｍ２／ｇの二酸化珪素を用い、水とミキサ
ーで混合し、１５％のスラリーを調整した。このスラリ
ーをスプレーガンを用いて図２に示す形状の内容積２Ｌ
のコージライト質ルツボの内面、蓋の内面、容器上部の
蓋と接する面及び蓋の容器と接する面に均一に吹き付
け、その後乾燥し充填用の容器とした。実施例３と同様
にしてトンネルキルンで加熱を実施した。加熱終了後ル
ツボを放冷し粉末状の内容物を取り出した。内容物を取
り出した後のルツボの各部には不均一にガラス状の付着
物が見られた。次にこのルツボを用いて１０回同様の加
熱操作を行った。１０回実施後のルツボ内には二酸化珪
素の剥がれ落ちた部分にガラス状の物が多量に付着して
いた。また、内容物も十分には取り出せず、取り出した
粉末を上水及び５％硝酸水溶液で洗浄、１２０℃で４時
間乾燥した後１７０ｇの粉末が得られた（実施例３に比
較し収量が８６％に低下した）。Comparative Example 3 Using silicon dioxide having a specific surface area of 10 m 2 / g, water and a mixer were mixed to prepare a 15% slurry. This slurry was sprayed with a spray gun to an inner volume of 2 L having the shape shown in FIG.
Was uniformly sprayed on the inner surface of the cordierite-based crucible, the inner surface of the lid, the surface of the upper part of the container in contact with the lid, and the surface of the lid in contact with the container, and then dried to obtain a container for filling. Heating was performed in a tunnel kiln in the same manner as in Example 3. After the heating, the crucible was allowed to cool, and the powdery content was taken out. After the contents were taken out, non-uniform glass-like deposits were observed in each part of the crucible. Next, the same heating operation was performed 10 times using this crucible. In the crucible after 10 times, a large amount of glass-like material was adhered to the portion where silicon dioxide was peeled off. Further, the contents were not sufficiently taken out, and the taken-out powder was washed with tap water and a 5% nitric acid aqueous solution and dried at 120 ° C. for 4 hours to obtain 170 g of a powder (compared to Example 3 with a yield of 86 g). %).
【００３１】[0031]
【発明の効果】本発明は窒化ホウ素を製造する際に用い
る容器の内面を二酸化珪素で被覆することを特徴とする
ものであり、被覆された容器を用いることにより、発生
するナトリウムが二酸化珪素と反応してガラス状の物が
均一に付着するため収率の低下や容器の劣化を防ぐこと
ができ、均一に付着したガラス質のものは、生成物が付
着し成長することはなく、ガラス質のものが生成物中に
入り窒化ホウ素の純度を下げる等の問題も解決した。か
くして得られた窒化ホウ素は、前述の通り希鉱酸で洗浄
後水洗するという簡単な精製方法を実施すれば、高純度
の品質とすることができる。本発明は以上記載の通り、
従来公知の方法に比べ種々の利点があり、その結果安価
でかつ大量に高純度の窒化ホウ素の製造を可能としたも
ので、その経済的効果は極めて大なるものである。The present invention is characterized in that the inner surface of a container used for producing boron nitride is coated with silicon dioxide. By using the coated container, the generated sodium is reduced to silicon dioxide. The glassy substance reacts and adheres uniformly, which can prevent the reduction of the yield and the deterioration of the container, and the vitreous one that adheres uniformly does not adhere to the product and grows. Solved the problems of lowering the purity of boron nitride into the product. The boron nitride thus obtained can be of high purity by performing a simple purification method of washing with dilute mineral acid and then washing with water as described above. The present invention, as described above,
There are various advantages as compared with the conventionally known methods, and as a result, it is possible to produce high-purity boron nitride inexpensively and in large quantities, and its economic effect is extremely large.
【００３２】[0032]
【図１】 本発明の実施に使用する耐熱性の蓋付き容器
の形状を示す各縦断面図である。FIG. 1 is a longitudinal sectional view showing a shape of a heat-resistant container with a lid used for carrying out the present invention.
【図２】 本発明の実施に使用する耐熱性の蓋付き容器
の形状を示す各縦断面図である。FIG. 2 is a longitudinal sectional view showing a shape of a heat-resistant container with a lid used for carrying out the present invention.
【図３】 本発明の実施に使用する耐熱性の蓋付き容器
の形状を示す各縦断面図である。FIG. 3 is a longitudinal sectional view showing the shape of a heat-resistant container with a lid used for carrying out the present invention.
【図４】 本発明の実施に使用する耐熱性の蓋付き容器
の形状を示す各縦断面図である。FIG. 4 is a vertical sectional view showing the shape of a heat-resistant container with a lid used for carrying out the present invention.
【図５】 実施例１で得られた窒化ホウ素のＸ線回折線
図を示す。5 shows an X-ray diffraction diagram of the boron nitride obtained in Example 1. FIG.
１ 容器 ２ 蓋 1 container 2 lid
Claims (4)
から選ばれた１種以上のホウ素化合物とＮＨ２基を有す
る有機化合物との混合物を耐熱性の蓋付き容器に入れ、
加熱する窒化ホウ素の製造法において、該耐熱性の蓋付
き容器の内面が二酸化珪素で被覆されていることを特徴
とする窒化ホウ素の製造法。1. A mixture of at least one boron compound selected from boric acids, boric anhydride and borates and an organic compound having an NH 2 group is placed in a heat-resistant lidded container.
A method for producing boron nitride, wherein the inner surface of the heat-resistant container with a lid is coated with silicon dioxide.
次粒子の比表面積が０．１ｍ２／ｇ以上である請求項１
記載の窒化ホウ素の製造法。2. The specific surface area of primary particles of silicon dioxide coated on a container with a lid is 0.1 m 2 / g or more.
The method for producing boron nitride according to the above.
散剤で分散する請求項１または２記載の窒化ホウ素の製
造法。3. The method for producing boron nitride according to claim 1, wherein the silicon dioxide to be coated on the lidded container is dispersed with a dispersant.
塩またはカチオン系の第４アンモニウム塩である請求項
３記載の窒化ホウ素の製造法。4. The method for producing boron nitride according to claim 3, wherein the dispersant is an anionic polycarboxylate or a cationic quaternary ammonium salt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10207797A JPH10291809A (en) | 1997-04-18 | 1997-04-18 | Production method of boron nitride |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10207797A JPH10291809A (en) | 1997-04-18 | 1997-04-18 | Production method of boron nitride |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10291809A true JPH10291809A (en) | 1998-11-04 |
Family
ID=14317720
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10207797A Pending JPH10291809A (en) | 1997-04-18 | 1997-04-18 | Production method of boron nitride |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10291809A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022202827A1 (en) * | 2021-03-25 | 2022-09-29 | デンカ株式会社 | Boron nitride particles and method for producing same, and resin composition |
-
1997
- 1997-04-18 JP JP10207797A patent/JPH10291809A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022202827A1 (en) * | 2021-03-25 | 2022-09-29 | デンカ株式会社 | Boron nitride particles and method for producing same, and resin composition |
| JPWO2022202827A1 (en) * | 2021-03-25 | 2022-09-29 |
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