JPS61215203A - Synthesis of cubic boron nitride - Google Patents

Abstract

PURPOSE:To carry out the synthesis of the titled product easily in an extremely high conversion, by contacting a raw material containing at least boron nitride or a raw material containing a catalytic substance and a specific metal or their compounds with borazine, etc. CONSTITUTION:The starting raw material of the present process is selected from (1) boron nitride, (2) a composition containing boron nitride, a catalytic substance and one or more substances selected from a metal of the group IVa, Va or VIa of the periodic table, Si, Al, iron-group metal or their compound, (3) a composition containing a catalytic substance and one or more substances selected from a metal of the group IVa, Va or VIa, Si, Al, iron-group metal or their compound, (4) a composition containing various metals, various metal compounds, carbonaceous substances, etc., in addition to the raw material 3, and (5) a composition containing the raw materials 3 and the raw material 4. The starting raw material is made to contact with borazine, a borazine derivative and/or a compound of B, H and N and capable of forming boron nitride by releasing H by thermal decomposition under pressure, and is treated under a temperature and pressure condition to enable the stable maintenance of cubic boron nitride. The obtained cubic boron nitride is separated from the reaction product.

Description

【発明の詳細な説明】 ［発明の技術分野］ 本発明は立方晶窒化ホウ素（以下、ｃＢＮという）の合
成法に関し、更に詳しくは、高圧高温下でｃＢＮを合成
する方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for synthesizing cubic boron nitride (hereinafter referred to as cBN), and more particularly to a method for synthesizing cBN under high pressure and high temperature.

［発明の技術的背景とその問題点］ ダイヤモンドに次ぐ硬質物質として高密度相窒化ホウ素
があり、これにはｃＢＮとウルツ鉱型窒化中つ素（以下
ｗＢＮという）がある０両者共に高圧高温条件下で合成
されるのが一般的であるが、このうち高圧高温条件下に
おけるｃＢＮの合成法としては触媒を用いない直接法と
特定の触媒物質を用いる触媒法とがある。しかしながら
、直接法による合成法では例えばＩＯＧ　Ｐａ以上の圧
力と２０００”０前後の温度が必要となるために、用い
る装置は極めて複雑かつ大規模化する。更にまた。直接
法による場合には従来、出発原料である六方晶窒化ホウ
素、（以下、ｈＢＮという）が１００％ｃＢＮに転換す
ることはないので、得られた窒化ホウ素はかなりの程度
、未転換のｈＢＮとｗＢＮとの混合体となることが避け
られない０通常、この未転換のｈＢＮは合成物から比較
的容易に除去することが出来るが、しかし、このｗＢＮ
を分離することは殆ど不可能なことである。[Technical background of the invention and its problems] There is a high-density phase boron nitride as a hard substance next to diamond, and this includes cBN and wurtzite-type nitride (hereinafter referred to as wBN).Both of them can be used under high pressure and high temperature conditions. Generally, cBN is synthesized under high-pressure, high-temperature conditions, including a direct method that does not use a catalyst and a catalytic method that uses a specific catalyst material. However, since the direct synthesis method requires a pressure of, for example, IOG Pa or higher and a temperature of around 2000"0, the equipment used becomes extremely complex and large-scale.Furthermore, in the case of the direct method, conventionally, Since the starting material hexagonal boron nitride (hereinafter referred to as hBN) is not 100% converted to cBN, the obtained boron nitride is to a considerable extent a mixture of unconverted hBN and wBN. Normally, this unconverted hBN can be removed relatively easily from the composition; however, this wBN
It is almost impossible to separate them.

一方、触媒法に関しては、例えば特公昭３８−１４及び
特公昭５２−１７８３８等に各種の触媒物質を用いたｃ
ＢＮの合成法が開示されている。これら公知の触媒法を
用いた場合は、まず第一に直接法における水準よりもか
なり低い圧力、温度でｃＢＮの合成が可能であり、かつ
得られる合成物にはｗＢＮの混入はないという利益を享
受できる。しかしながら。On the other hand, regarding catalytic methods, for example, Japanese Patent Publication No. 38-14 and Japanese Patent Publication No. 52-17838 used various catalyst materials.
A method of synthesizing BN is disclosed. When these known catalytic methods are used, first of all, cBN can be synthesized at considerably lower pressure and temperature than the level of the direct method, and the resulting composite has the advantage of not being contaminated with wBN. You can enjoy it. however.

この場合においてもｃＢＮへの転換は　１００％ではな
く、比較的低いのが通例である。Even in this case, the conversion to cBN is not 100% and is usually relatively low.

［発明の目的］ 本発明は、ｃＢＮの合成における上記従来方法の問題を
解消し、簡便にして極めて高い転換率で。[Object of the Invention] The present invention solves the problems of the above-mentioned conventional methods in synthesizing cBN, and synthesizes cBN easily and at an extremely high conversion rate.

したがって経済的にｃＢＮを合成する方法の提供を目的
とする。Therefore, it is an object of the present invention to provide a method for economically synthesizing cBN.

［発明の概要］ 本発明者らは、前述した従来技術におけるｃＢＮ転換率
が低い原因に関し追求したところ、直接法によると触媒
法によるとにかかわらず、原料である非立方晶窒化ホウ
素からｃＢＮへの転換率を高め、　ｃＢＮの安定な温度
圧力条件内で出来るだけ低い圧力温度でｃＢＮを得るた
めには、原料の非立方晶窒化ホウ素に不純物として物理
的・化学的に吸着している酸素又は化学的に結合してい
る酸素成分の量を極力少なくすることが重要であり、ま
た、原料の非立方晶窒化ホウ素は結合水素を有し結晶度
の低いことが重要な因子であることを見出した。[Summary of the Invention] The present inventors investigated the cause of the low cBN conversion rate in the prior art described above, and found that cBN can be converted from non-cubic boron nitride as a raw material, regardless of whether it is a direct method or a catalytic method. In order to increase the conversion rate of cBN and obtain cBN at the lowest possible pressure and temperature within the stable temperature and pressure conditions of cBN, oxygen or We discovered that it is important to minimize the amount of chemically bonded oxygen components, and that the non-cubic boron nitride raw material has bonded hydrogen and low crystallinity, which is an important factor. Ta.

本発明者らは、上記知見に基づき、原料の非立方晶窒化
ホウ素がｃＢＨに転換する過程でそれを阻害する酸素成
分の排除につき研究を重ねる中で、それ自身が熱分解し
て窒化ホウ素に転化する後述のボラジン等で原料の非立
方晶窒化ホウ素を処理したところ、次のように重要な知
見を得るに到った。　　　・ まず第１には、加圧加熱処理を施す前に、非立方晶窒化
ホウ素の原料粉末に例えばボラジン（常温で液体）を注
加すると、粉末間に存在する空隙がこのボラジンで満た
されることにより空隙から空気すなわち酸素が追放され
、その結果、原料粉末のｃＢＮへの転換率が著しく向上
するということである。Based on the above findings, the present inventors conducted research on eliminating the oxygen component that inhibits the conversion of non-cubic boron nitride into cBH. When the raw material non-cubic boron nitride was treated with borazine, which will be described later, the following important findings were obtained. - First of all, if, for example, borazine (liquid at room temperature) is poured into the raw material powder of non-cubic boron nitride before the pressure heat treatment, the voids existing between the powders will be filled with this borazine. This means that air, ie, oxygen, is expelled from the voids, and as a result, the conversion rate of the raw powder to cBN is significantly improved.

第２には、該空隙を満たしているボラジンは加圧加熱の
過程で熱分解して水素を発生し、この発生期の水素が原
料の非立方晶窒化ホウ素と強固に結合又は吸着していた
酸素を取り去り上記第１の効果を更に著しく高めるとい
うことである。Second, the borazine filling the voids thermally decomposed during the pressurized heating process to generate hydrogen, and this generated hydrogen was strongly combined or adsorbed with the raw material, non-cubic boron nitride. This means that by removing oxygen, the above-mentioned first effect is further significantly enhanced.

第３には、該ボラジンは上記のごとく加圧加熱の過程で
熱分解して水素を放出し、結局自らは窒化ホウ素へと転
化するが、このようにして得られる窒化ホウ素は極めて
純度が高いのみならず、比較的結晶度が低く、かつ結合
水素を有するｃＢＮの合成には最も好ましいということ
である。即ち、発明者等の研究によると、結晶度の高い
市販のｈＢＮと、ボラジン等の加圧子熱分解によってえ
られた純度高く結晶度の低い窒化ホウ素とのｃＢＮへの
転換に要する活性化エネルギーは、ＡＩＭの存在の下で
、それぞれ前者が４０乃至８０Ｋｃａｌ／　ｍｏｂであ
るのに対し、後者では約２０Ｋｃａｌ／　ｍａｌであり
、従ってボラジンの加圧子熱分解によってえられた純度
高く結晶度の低い窒化ホウ素はｃＢＮへの転換率は極め
て高いのである。Thirdly, as mentioned above, the borazine thermally decomposes and releases hydrogen in the process of pressurization and heating, and eventually converts itself into boron nitride, and the boron nitride obtained in this way has extremely high purity. Moreover, it is most preferable for the synthesis of cBN which has relatively low crystallinity and has bonded hydrogen. That is, according to the research of the inventors, the activation energy required for the conversion of commercially available hBN with high crystallinity and boron nitride with high purity and low crystallinity obtained by pyrolysis of pressurizers such as borazine into cBN is as follows. , in the presence of AIM, respectively, while the former is 40 to 80 Kcal/mob, while the latter is about 20 Kcal/mal, thus the high purity and low crystallinity boron nitride obtained by pressor pyrolysis of borazine. The conversion rate to cBN is extremely high.

、第４には、　ｃＢＮ自身が非立方晶窒化ホウ素からｃ
ＢＮへの転換に際して良好な触媒として働くということ
である。ボラジンの加圧下顎熱分解によって生成した純
度高く結晶度低く、結合水素を有する窒化ホウ素は上述
の理由により市販のｈＢＮである原料の非立方晶窒化ホ
ウ素の場合よりも容易にｃＢＮに転換する。従って、こ
れが原料の非立方晶窒化ホウ素のｃＢＮへの転換のため
の触媒として働き、出発原料には必ずしも触媒物質を混
合することが必要ではなくなるのである。, fourthly, cBN itself is converted from non-cubic boron nitride to c
This means that it acts as a good catalyst in the conversion to BN. Boron nitride with high purity, low crystallinity, and bound hydrogen produced by pressurized mandibular pyrolysis of borazine is more easily converted to cBN than the raw non-cubic boron nitride, which is commercially available hBN, for the reasons described above. Therefore, it acts as a catalyst for the conversion of the raw material non-cubic boron nitride to cBN, and it is not necessarily necessary to mix a catalytic material with the starting material.

第５には、ボラジンは液体であるためそれが原料粉末の
空隙に充満されている場合に、加圧加熱の段階で高圧容
器内には理想的な静水圧状態が現出し、そのためｃＢＮ
への転換が一層容易に進行するということである。Fifth, since borazine is a liquid, when it fills the voids in the raw material powder, an ideal hydrostatic pressure state appears in the high-pressure container during the pressurization and heating stage, and as a result, cBN
This means that the transition will proceed more easily.

木発明者らは、原料粉末を液体であるボラジンで処理し
た特殊事例における上記知見を基礎にして、原料の検討
、ボラジン以外の原料処理剤の検討を進めた結果、後述
する本発明の合成法を開発するに到った。Based on the above-mentioned findings from a special case in which a raw material powder was treated with liquid borazine, the inventors investigated raw materials and raw material processing agents other than borazine, and as a result, the synthesis method of the present invention, which will be described later, was developed. We have come to develop this.

すなわち、本発明のｃＢＮの合成法は、少なくとも窒化
ホウ素を含む出発原料又は触媒物質及び周期律表ＩＶａ
族、Ｖａ族、ＶＩａ族の金属、ケイ素。That is, the cBN synthesis method of the present invention uses a starting material or catalyst material containing at least boron nitride and
Group Va, Group VIa metals, silicon.

アルミニウム、鉄族金属若しくはそれらの化合物の群か
ら選ばれる少なくとも１種を含む出発原料を、ボラジン
、ボラジン誘導体及び／又は加圧子熱分解時に水素を放
出して窒化ホウ素に転化するホウ素と水素と窒素との化
合物（以下、ボラジン等という）に接触せしめ、ついで
、立方晶窒化ホウ素の安定温度圧力条件下で処理し、得
られた処理物から立方晶窒化ホウ素を回収することを特
徴とする。Boron, hydrogen and nitrogen, in which a starting material containing at least one selected from the group of aluminum, iron group metals or their compounds is converted into boron nitride by releasing hydrogen during pyrolysis of borazine, borazine derivatives and/or pressurizers. The method is characterized in that cubic boron nitride is brought into contact with a compound (hereinafter referred to as borazine, etc.), and then treated under stable temperature and pressure conditions for cubic boron nitride, and cubic boron nitride is recovered from the resulting treated product.

まず、本発明における出発原料は次のように大、別でき
る。First, the starting materials in the present invention can be broadly classified as follows.

第１は、出発原料が窒化ホウ素から成る場合。The first is when the starting material consists of boron nitride.

第２は、出発原料が窒化ホウ素と触媒物質及び周期律表
ＩＶａ族、Ｖａ族、■ａ族の金属、ケイ素。Second, the starting materials are boron nitride, a catalyst material, metals from Group IVa, Group Va, and Group IIa of the periodic table, and silicon.

アルミニウム、鉄族金属若しくはそれらの化合物の群か
ら選ばれる少なくとも１種を含む場合、第３は、出発原
料が触媒物質及び周期律表ＩＶａ族。Thirdly, when the starting material contains at least one selected from the group of aluminum, iron group metals, or compounds thereof, the starting material is a catalyst material and a member of Group IVa of the periodic table.

Ｖａ族、ＶＩａ族の金属、ケイ素、アルミニウム。Group Va, group VIa metals, silicon, aluminum.

鉄族金属若しくはそれらの化合物の群から選ばれる少な
くとも１種を含む場合、第４は、出発原料が第３で述べ
た出発原料の他に各種金属、各種金属化合物、炭素物質
などを含有した窒化ホウ素から成る場合、第５は、出発
原料が第４で述べた出発原料と第３で述べた出発原料を
含んでいる場合に別けることができる。In the case where the starting material contains at least one selected from the group of iron group metals or their compounds, the fourth is a nitrided material in which the starting material contains various metals, various metal compounds, carbon substances, etc. in addition to the starting materials mentioned in the third. In the case of boron, the fifth can be separated if the starting material contains the starting material mentioned in the fourth and the starting material mentioned in the third.

こ゛こで、窒化ホウ素としては、例えば、非晶質窒化ホ
ウ素（ａＢＮ）　、ｈＢＮ、ｗＢＮ、ｃＢＮのいずれで
あってもよく、これらをそれぞれ単独で又は２種以上を
適宜に組合わせて用いることができる。Here, boron nitride may be, for example, amorphous boron nitride (aBN), hBN, wBN, or cBN, and each of these may be used alone or in an appropriate combination of two or more types. I can do it.

また、触媒物質としては周期律表Ｉａ、■ａ。In addition, examples of catalytic substances include Ia and ■a of the periodic table.

ＩＩｒａ族元素、　Ｓｂ、　Ｓｎ、　ｐｂノ金金属台合
金窒化物及び周期律表ｍｂ族元素の窒化物、ホウ化物並
びにこれらの相互固溶体で１例えばＬｉ、　Ｎａ、　Ｋ
　、　Ｒｈ。Group IIra elements, Sb, Sn, PB metal base alloy nitrides, nitrides, borides of MB group elements of the periodic table, and their mutual solid solutions, such as Li, Na, K.
, Rh.

Ｂｅ、　Ｍｇ、　Ｃａ、　Ｓｒ、　Ｂａ、　Ｒａ、　Ｓ
ｃ、　Ｙ　　、及びＬａ　、　Ｃｅ　。Be, Mg, Ca, Sr, Ba, Ra, S
c, Y, and La, Ce.

Ｐｒなどのランタノイド、　Ｓｂ、　Ｓｎ、　Ｐｂから
なる金属又は合金、Ｌｉ３Ｎ　、　Ｎａ５Ｎ　、　Ｋ３
Ｎ　、　Ｒｈ３Ｎ　、　Ｃｓ３Ｎ　。Lanthanoids such as Pr, metals or alloys consisting of Sb, Sn, Pb, Li3N, Na5N, K3
N, Rh3N, Cs3N.

Ｂｌ！３Ｎ２　、　Ｍｇ３Ｎ２　、０ａ３Ｎ２　、５ｒ
３Ｎ２　、　Ｂａ３Ｎ２　。Bl! 3N2, Mg3N2, 0a3N2, 5r
3N2, Ba3N2.

Ｒａ３Ｎ２　　、ＳｃＮ　　、ＹＮ、ＬａＮ　　、Ｃｅ
Ｎ　　、ＥｕＮ　　、ＤｙＮ　　。Ra3N2, ScN, YN, LaN, Ce
N, EuN, DyN.

ＩＱＮ、　　ＧａＮ　　　、　　ＩｎＮ　　　、　　　
丁ＩＮ、　　　ＡｌＢ２　　　、　　　ＡＭＢＢ　　　
。IQN, GaN, InN,
DIN, AlB2, AMBB
.

ＡＱＢＩＯ、ＡｊｌＢ１２　、　（Ｍｇ３．Ａ！２．）
Ｎ３　、　（Ｇａ３．Ａ１１）Ｎ３゜（Ｙ、Ａ４）Ｎ２
などを用いることができる。これらの触媒物質は、ａＢ
Ｎ、ｈＢＨなどの窒化ホウ素がｃＢＮに転換するための
促進作用をすると共にボラジン、ホラジン誘導体及び窒
化ホウ素に転化するホウ素と水素と窒素との化合物がｃ
ＢＮに転換するための促進作用ともなるものである。AQBIO, AjlB12, (Mg3.A!2.)
N3, (Ga3.A11)N3゜(Y,A4)N2
etc. can be used. These catalytic materials are aB
Boron nitride such as N and hBH acts to promote the conversion to cBN, and compounds of boron, hydrogen, and nitrogen that are converted to borazine, phorazine derivatives, and boron nitride are c
It also acts as a catalyst for conversion to BN.

さらに、上述の触媒物質の他に、ｃＢＮの合成反応後に
ｃＢＮと他の物質又はｃＢＮとｃＢＮの分離の容易性及
びｃＢＮの回収の容易性を目的にして、あらゆる物質を
出発原料中に添加することもできる。Furthermore, in addition to the above-mentioned catalyst substances, any substance may be added to the starting material after the cBN synthesis reaction for the purpose of facilitating the separation of cBN and other substances or cBN and cBN, and facilitating the recovery of cBN. You can also do that.

この物質の代表例として、周期律表ｆｆａ、Ｖａ。Representative examples of this substance include ffa and Va in the periodic table.

ＶＩａ族の金属、ケイ素、アルミニウム、鉄族金属若し
くはそれらの化合物があり、具体的に示すと、例えば、
？’＋　＋　Ｚｒ、　Ｈｆｃ’）周期律表ＩＶａ族、ｖ
。Examples include group VIa metals, silicon, aluminum, iron group metals, or compounds thereof, and specifically, for example,
? '+ + Zr, Hfc') Periodic Table Group IVa, v
.

Ｎｂ、Ｔａｃ７）周期律表Ｖａ族、　　Ｏｒ、Ｎｏ、−
の周期律表ＶＩａ族、　　Ｓｉ、　Ａｎ　、　Ｆｅ、　
Ｇｏ、　Ｎｉの鉄族金属のような金属；若しくはＸｌ−
ＡｆＬ合金、　Ｎｉ−Ｃｒ合金。Nb, Tac7) Periodic table Va group, Or, No, -
Group VIa of the periodic table, Si, An, Fe,
Metals such as Go, Ni, iron group metals; or Xl-
AfL alloy, Ni-Cr alloy.

Ｎｉ−Ｓｉ合金、　Ｎｉ−Ｎｏ合金、旧−Ｔｉ合金、Ａ
文−Ｓｉ合金、　　Ａｆｆｉ−Ｔｉ合金、　Ｃｏ基耐熱
合金９．旧基耐熱合金のような上記各金属の合金、　　
ＴｉＡ見、ＴｉＡ１３゜ＺｒＡ見３．　ＮｂＡＪ１３．
　ＴａＡ１３．　Ｍｏ３Ａ１．　Ｃｏａｌ、　ＮｉＡ１
゜Ｆｅ５ＡＪｌ、　Ｆｅ２Ｔｉ、　ＮｉＴｉ２．　Ｎｉ
Ｔｉ、旧３（ＡＭ、Ｔｉ）、　Ｎｉ３Ｔｉ。Ni-Si alloy, Ni-No alloy, old-Ti alloy, A
Affi-Si alloy, Affi-Ti alloy, Co-based heat-resistant alloy9. Alloys of each of the above metals, such as old-based heat-resistant alloys,
TiA view, TiA13°ZrA view 3. NbAJ13.
TaA13. Mo3A1. Coal, NiA1
゜Fe5AJl, Fe2Ti, NiTi2. Ni
Ti, old 3 (AM, Ti), Ni3Ti.

Ｇｏ２Ｔｉ、　Ｎｉ３Ａｉ　　のような上記各金属の金
属間化合物、　ＴｉＣ，ＺｒＣ，ＨｆＣ，ＶＣ，ＮｂＣ
，ＴａＣ，０ｒ３Ｇ２゜Ｍｏ２Ｃ，ＷＣ，Ｓｉｎ、Ｔｉ
Ｎ、　ＺｒＮ、　ＨｆＮ、　ＶＮ、　ＮｂＮ、　Ｔａｇ
。Intermetallic compounds of each of the above metals such as Go2Ti, Ni3Ai, TiC, ZrC, HfC, VC, NbC
, TaC, 0r3G2゜Mo2C, WC, Sin, Ti
N, ZrN, HfN, VN, NbN, Tag
.

Ｓｉ３Ｎ４．　ＴｉＢ２．　ＺｒＢ２．　ＴａＢ２．　
ＷＢ、　ＡｆＬＢ１２．　Ａ１２０３゜Ｔ１ＣＮ、　（
Ｔｉ、Ｔａ）Ｃ，（Ｔｉ、Ｔａ）ＯＮ、　（Ｔｉ、Ｗ）
Ｃ，（Ｔｉ、Ｗ）Ｇ）ｌ。Si3N4. TiB2. ZrB2. TaB2.
WB, AfLB12. A1203゜T1CN, (
Ti, Ta) C, (Ti, Ta) ON, (Ti, W)
C, (Ti, W) G)l.

（Ｔｉ、Ｗ）ＯＮ、　（Ｔｉ、Ｔａ、Ｗ）Ｃ，（Ｔｉ、
Ｔａ、Ｗ）ＯＮのような上記各金属の化合物；の群から
選ばれる少なくとも１種を含むものを用いることができ
る。(Ti, W) ON, (Ti, Ta, W) C, (Ti,
Compounds of the above-mentioned metals such as Ta, W)ON, etc. can be used.

次に、上記各出発原料に接触せしめるボラジン等は、そ
れ自体がｃＢＮに転換される主構成成分であり、以下の
ようなものを列挙することができる。Next, borazine and the like that are brought into contact with each of the above starting materials are themselves main constituents that are converted into cBN, and the following can be enumerated.

第１のグループはボラジン（ａ３ｓ３ｎＢ　、常温常圧
で液体）それ自体である。The first group is borazine (a3s3nB, liquid at room temperature and pressure) itself.

第２のグループは、２，４−ジアミノボラジン（８３Ｎ
５ＨＱ　、常温常圧で液体）、ポラゾナフタリン（８５
Ｎ５Ｈ８、常温常圧で固体）、ボラゾビフェニル（８８
Ｎ８Ｈ１０、常温常圧で固体）のようなボラジン誘導体
である。The second group consists of 2,4-diaminoborazine (83N
5HQ, liquid at normal temperature and pressure), porazonaphthalene (85
N5H8, solid at room temperature and pressure), borazobiphenyl (88
Borazine derivatives such as N8H10 (solid at room temperature and pressure).

第３のグループは、加圧子熱分解時に水素を放出して窒
化ホウ素に転化するホウ素と水素と窒素の化合物であっ
て１例えば、ジボラン（Ｂ２Ｈ８）　、テトラボラン（
８４）１１０）　　、ペンタボラ７−９（Ｂ５Ｈ９）の
ような気体状ボラン類とアンモニアガスとの混合気体又
はデカボランのような固体状ボラン類とアンモニアガス
との混合物をあげることができる。The third group is compounds of boron, hydrogen, and nitrogen that release hydrogen and convert into boron nitride during indenter pyrolysis, such as diborane (B2H8), tetraborane (
84), 110), a gaseous mixture of gaseous borane such as pentaborane 7-9 (B5H9) and ammonia gas, or a mixture of solid borane such as decaborane and ammonia gas.

前述した出発原料と上記ボラジン等を接触せしめる態様
は、用いるボラジン等が液体、固体、気体のいずれかで
あるかによって相違してくる。The manner in which the above-mentioned starting material and the above-mentioned borazine etc. are brought into contact differs depending on whether the borazine etc. used is a liquid, solid, or gas.

まず、ボラジン等が液体である場合には、次のような態
様を採ることができる０例えば、その１つは、出発原料
を高圧用容器内に充填するに先立ち、出発原料を構成す
る各粉末を液体であるボラジン等で湿潤しながら湿式混
合して粉末表面に吸蔵されている空気（酸素）をボラジ
ンで追放・置換し、この湿潤混合粉末をそのまま容器内
に充填したり、又はこの混合粉末をプレス成形して圧粉
体としこれを容器内に充填する態様である。この場合、
容器内に充填した混合粉末若しくは圧粉体に、更に液体
のボラジン等を注入して含浸せしめると一層効果的であ
る。First, when borazine etc. is a liquid, the following methods can be adopted.For example, one of the methods is to prepare each powder constituting the starting material before filling the starting material into a high-pressure container. is wet-mixed while moistened with a liquid such as borazine, the air (oxygen) occluded on the powder surface is expelled and replaced with borazine, and this wet mixed powder is filled into a container as it is, or this mixed powder is This is an embodiment in which the powder is press-molded to form a green compact, which is then filled into a container. in this case,
It is more effective to further inject liquid borazine or the like into the mixed powder or green compact filled in the container to impregnate it.

また、出発原料の各粉末を乾式混合し、得られた混合粉
末を適宜な成形圧でプレス成形して圧粉体とし、これを
容器内に充填したのち、ここにボラジン等を注入して圧
粉体内の空隙をボラジン等で充満せしめる態様である。In addition, the starting raw material powders are dry mixed, the resulting mixed powder is press-molded at an appropriate molding pressure to form a green compact, this is filled into a container, and then borazine, etc. is injected into the compact. This is an embodiment in which the voids within the powder are filled with borazine or the like.

圧粉体の成形時に適用する成形圧を適宜な値に設定すれ
ば得られた圧粉体の空隙率を任意の値にすることができ
る。この態様の場合は、圧粉体の空隙はほぼ１００％ボ
ラジン等で充満せしめられ、出発原料に吸着されていた
空気（酸素）が追い出されるのみならず、次の加圧加熱
処理過程で容器内が静水圧状態となるのでｃＢＮの転換
率向上への作用効果は大である。By setting the compacting pressure applied during molding of the green compact to an appropriate value, the porosity of the obtained green compact can be set to an arbitrary value. In this case, the voids in the powder compact are almost 100% filled with borazine, etc., and the air (oxygen) adsorbed in the starting material is not only expelled, but also removed from the inside of the container during the next pressure and heat treatment process. is in a hydrostatic pressure state, which has a great effect on improving the conversion rate of cBN.

次にボラジン等が固体である場合には、出発原料とこの
固体状ボラジン等を常法によって充分混合し、得られた
混合粉末が所定空隙率の圧粉体を成形し、この圧粉体を
高圧容器に充填したのち。Next, when borazine, etc. is solid, the starting material and this solid borazine, etc. are thoroughly mixed by a conventional method, and the resulting mixed powder is molded into a green compact with a predetermined porosity. After filling the high pressure container.

圧粉体の空隙にアンモニアガス、窒素、不活性ガスを圧
入して空隙内の空気（酸素）を追放する手段を講じれば
よい、もち論、容器充填後の圧粉体に液体のボラジン等
を注入してもよい。It is sufficient to take measures to forcefully inject ammonia gas, nitrogen, or inert gas into the voids of the powder compact to expel the air (oxygen) in the voids.Of course, liquid borazine or the like may be added to the compact after filling the container. May be injected.

また、用いるボラジン等が気体である場合には、高圧容
器内に充填した出発原料の空隙又は出発原料から成形し
た圧粉体の空隙に上記した気体状のボラジン等を圧入し
て空隙から空気（酸素）を追放するという手段を講じれ
ばよい。In addition, when the borazine or the like used is a gas, the above-mentioned gaseous borazine or the like is pressurized into the voids of the starting material filled in a high-pressure container or the voids of a green compact molded from the starting material, and air ( All you need to do is to expel the oxygen (oxygen).

以上各態様の接触手段のうち、液体のボラジン等を用い
た方法が作業性の点からいって最も好適である。Among the various contact means described above, a method using liquid borazine or the like is most suitable from the viewpoint of workability.

本発明方法においては１以上のようにして出発原料とボ
ラジン等を接触せしめた内容物を収容する高圧内容器を
所定の高温高圧装置にセットして加圧加熱下で合成反応
を進める。In the method of the present invention, a high-pressure inner container containing the contents in which the starting material and borazine, etc. are brought into contact in one or more ways is set in a predetermined high-temperature and high-pressure apparatus, and the synthesis reaction proceeds under pressure and heating.

このときの処理条件はｃＢＮの安定な温度圧力条件であ
ることが必要で、この条件から外れると、結局はｃＢＮ
への転換率が低下したり、工業化するのが困難になるか
らである。The processing conditions at this time must be stable temperature and pressure conditions for cBN, and if these conditions are deviated from, cBN will eventually become
This is because the conversion rate to carbon dioxide will decrease and it will be difficult to industrialize.

具体的には、温度７００℃、好ましくは１２００〜２０
００℃、圧力３ＧＰａ以上、好ま・しくは５．０〜８．
０ＧＰａである。Specifically, the temperature is 700°C, preferably 1200-20°C.
00°C, pressure 3 GPa or more, preferably 5.0 to 8.
It is 0GPa.

かくしてｃＢＮへの合成反応が進む、最後に、得られた
反応生成物から未転換の非立方晶窒化ホウ素や前述した
金属若しくは金属の化合物を除去してｃＢＮを回収する
。In this way, the synthesis reaction to cBN proceeds.Finally, cBN is recovered by removing unconverted non-cubic boron nitride and the aforementioned metal or metal compound from the obtained reaction product.

例えば、反応生成物を酸若しくはアルカリの溶液に浸漬
し、必要に応じては加熱して残存する金属若しくは金属
の化合物を溶解・除去し、更にその残渣を水若しくは有
機溶剤で洗浄する方法、又は、ｃＢＮと他の非立方晶窒
化ホウ素の比重差を利用して洗浄時にｃＢＮのみを分離
する方法、などの化学的若しくは物理的な手法を適用す
ることができる。For example, a method of immersing the reaction product in an acid or alkali solution, heating if necessary to dissolve and remove the remaining metal or metal compound, and further washing the residue with water or an organic solvent; Chemical or physical methods such as a method of separating only cBN during cleaning using the difference in specific gravity between cBN and other non-cubic boron nitrides can be applied.

実施例１ 内！１１ｍｍのジルコニウム製カプセルの中にｈＢＮ粉
末５５０■ｇ充填し、約１ｔｏｎ／ｃｍ”の圧力で押圧
して、空隙率３４マｏ１％の圧粉体とした。Example 1 Inside! 550 g of hBN powder was filled into an 11 mm zirconium capsule and pressed at a pressure of about 1 ton/cm" to form a green compact with a porosity of 34 mO1%.

つぎに、窒素雰囲気中で、このカプセル内に注入器を用
いてボラジンを滴下注入し圧粉体に充分滲透せしめたの
ちカプセルを封口した。このカプセルをカーボンヒータ
内蔵のカードル型高温高圧装置内に埋設し、　８分間で
６．５ＧＰａまで昇圧後。Next, in a nitrogen atmosphere, borazine was injected dropwise into the capsule using a syringe to sufficiently permeate the powder compact, and then the capsule was sealed. This capsule was buried in a card-type high-temperature, high-pressure device with a built-in carbon heater, and the pressure was increased to 6.5 GPa in 8 minutes.

１０分間で１７００℃まで昇温した。この状態を３０分
間維持したのち降温し、しかるのち降圧した。カプセル
内の生成物をＸ線回折分析にかけたところ。The temperature was raised to 1700°C in 10 minutes. After this state was maintained for 30 minutes, the temperature was lowered, and then the pressure was lowered. The product inside the capsule was subjected to X-ray diffraction analysis.

ｃＢＮであることが確認された。このｃＢＮの生成量は
１４０濡ｇであった。It was confirmed that it was cBN. The amount of cBN produced was 140 wet g.

実施例２ 出発原料が、ａＢＮであることを除いては、実施例１と
同様の条件で合成反応を行なった。このときのｃＢＮの
生成量は、２８０■ｇであった。Example 2 A synthesis reaction was carried out under the same conditions as in Example 1, except that the starting material was aBN. The amount of cBN produced at this time was 280 g.

実施例３ 出発原料が、　ａＢＮで、ボラジンに代えて２．４−ジ
アミノボラジンを使用したことを除いては、実施例１と
同様の条件で合成反応を行なった。このときのｃＢＮの
生成量は、２５０■ｇであった。Example 3 A synthesis reaction was carried out under the same conditions as in Example 1, except that the starting material was aBN and 2,4-diaminoborazine was used in place of borazine. The amount of cBN produced at this time was 250 g.

実施例４ 出発原料が、ｃＢＮであることを除いては、実施例１と
同様の条件で合成反応を行なった。このときの生成物を
後処理せずにＸ線回折によって分析した所、　ｃＢＮの
回折線のみであった。このｃＢＨの生成量は、７００１
ｇであった。Example 4 A synthesis reaction was carried out under the same conditions as in Example 1, except that the starting material was cBN. When the product at this time was analyzed by X-ray diffraction without post-treatment, only the diffraction line of cBN was found. The amount of cBH produced is 7001
It was g.

実施例５ 金カプセルの中にボラジンを封入し、これを熱分解装置
にかけて圧力１００ＭＰａ　、温度３００℃、保持時間
　１時間の条件で加圧子熱分解処理した。白色粉末を得
た。この粉末を、赤外吸収スペクトル分析にかけたとこ
ろ、Ｂ−Ｈ／Ｂ−Ｎ　−ＯＪを有する非晶質窒化ホウ素
（ａＢＮ）であった、この非晶質窒化ホウ素（ａＢＮ）
　７７体積％と　Ａｉ　Ｎ　２３体積％を出発原料とし
、反応条件が圧力８ＧＰａ　、温度１３００℃、保持時
間３０分であることを除いては、実施例１と同様にして
合成反応を行なった。このときのｃＢＮの生成量は、８
９０１ｇであった。これは、　ａＢＮとボラジンからの
ｃＢＮへの転換率がほぼ１００％に相当するものであっ
た。Example 5 Borazine was sealed in a gold capsule and subjected to thermal decomposition treatment using a pressurizer under the conditions of a pressure of 100 MPa, a temperature of 300° C., and a holding time of 1 hour. A white powder was obtained. When this powder was subjected to infrared absorption spectrum analysis, it was found to be amorphous boron nitride (aBN) having B-H/B-N-OJ.
A synthesis reaction was carried out in the same manner as in Example 1, except that 77% by volume and 23% by volume of AiN were used as starting materials, and the reaction conditions were a pressure of 8 GPa, a temperature of 1300° C., and a holding time of 30 minutes. The amount of cBN produced at this time is 8
It was 901g. This corresponded to a conversion rate of aBN and borazine to cBN of almost 100%.

実施例６ 出発原料がｈＢＮ　５０体積％と１ｇ３Ｎ２５０体積％
で。Example 6 Starting materials are hBN 50% by volume and 1g3N250% by volume
in.

反応条件が圧力８０Ｐａ　、温度１３００℃、保持時間
３０分であることを除いては、実施例１と同様にして合
成反応を行なった。このときのｃＢＮの生成量は４２０
ｍｇであった。これは、ｈＢＮとボラジンからのｃＢＮ
への転換率がほぼ１００％に相当するものであった。A synthesis reaction was carried out in the same manner as in Example 1, except that the reaction conditions were a pressure of 80 Pa, a temperature of 1300° C., and a holding time of 30 minutes. The amount of cBN produced at this time was 420
It was mg. This is cBN from hBN and borazine
The conversion rate was almost 100%.

実施例７ 出発原料が結晶性の低いｈＢＮ（ａＢＮとｈＢＮの混在
物）６０体積％トＴｉＣ２０体積％トＡｆＬＮ　　２０
体積％で、反応条件が圧力８０Ｐａ　、温度１３０Ｇ”
ｏ　、保持時間３０分であることを除いては、実施例１
と同様にして合成反応を行なった。このときのｃＢＮの
生成量は、４１０１ｇであった。これは、ｈＢＮとボラ
ジンからのｃＢＮへの転換率がほぼ１００％に相当する
ものであった・ 実施例８ 出発原料が、ａＢＮ　９０体積％と−Ｇ　１０体積％で
あることを除いては、実施例１と同様の条件で合成反応
を行なった。このときのｃＢ）ｌの生成量は。Example 7 The starting materials were hBN with low crystallinity (a mixture of aBN and hBN) 60% by volume, TiC 20% by volume, and AfLN 20
% by volume, reaction conditions are pressure 80 Pa, temperature 130 G”
o, Example 1 except that the holding time was 30 minutes.
The synthesis reaction was carried out in the same manner. The amount of cBN produced at this time was 4101 g. This corresponded to a conversion rate of hBN and borazine to cBN of almost 100%.Example 8 Except that the starting materials were 90% by volume of aBN and 10% by volume of -G. A synthesis reaction was carried out under the same conditions as in Example 1. The amount of cB)l produced at this time is.

２８０層ｇであった。The weight was 280 g.

実施例９ 出発原料がＡＪＬＮであることを除いては、実施例１と
同様の条件で合成反応を行なった。このときのｃＢＮの
生成量は、　ｌ１３Ｇｍｇであった。これは、ボラジン
からのｃＢＮへの転換率がほぼ１００％に相当するもの
であった。Example 9 A synthesis reaction was carried out under the same conditions as in Example 1, except that the starting material was AJLN. The amount of cBN produced at this time was 113 Gmg. This corresponded to a conversion rate of borazine to cBN of approximately 100%.

［発明の効果］ 以上の説明で明らかなように１本発明方法によれば、非
常に高い転換率で非立方晶窒化ホウ素からｃＢＮを合成
することができる。そして、従来公知の方法に比べて、
　ｃＢＨの安定な温度圧力条件の枠内にあっても比較的
低い温度、圧力条件下でｃＢＮの合成が可能である。こ
のことは、当業者間では周知のように、超高圧高温の領
域にあっては、たとえその圧、温度が僅少であったとし
てもそれらをより高い領域にシフトすることは技術的に
非常に困難なことであり、しかも甚だコスト高　　゛を
招く問題であるため１回の処理を可能な限り高効率で進
めることが経済的に重要な問題であるということからし
て１本発明方法の工業的価値の大きさを証明するもので
ある。[Effects of the Invention] As is clear from the above description, according to the method of the present invention, cBN can be synthesized from non-cubic boron nitride at a very high conversion rate. And compared to conventionally known methods,
Even within the framework of stable temperature and pressure conditions for cBH, cBN can be synthesized under relatively low temperature and pressure conditions. As is well known among those skilled in the art, in the area of ultra-high pressure and high temperature, it is technically very difficult to shift the pressure and temperature to a higher area, even if the pressure and temperature are small. This is a problem that is difficult and leads to extremely high costs, and since it is an economically important problem to proceed with each treatment as efficiently as possible, the industrialization of the method of the present invention is considered to be difficult. This proves the great value of the project.

Claims (1)

【特許請求の範囲】[Claims] 少なくとも窒化ホウ素を含む出発原料又は触媒物質及び
周期律表IVａ族、Ｖａ族、VIａ族の金属、ケイ素、アル
ミニウム、鉄族金属若しくはそれらの化合物の群から選
ばれる少なくとも１種を含む出発原料を、ボラジン、ボ
ラジン誘導体及び／又は加圧下熱分解時に水素を放出し
て窒化ホウ素に転化するホウ素と水素と窒素との化合物
に接触せしめ、立方晶窒化ホウ素の安定温度圧力条件下
で処理し、得られた反応生成物から立方晶窒化ホウ素を
回収することを特徴とする立方晶窒化ホウ素の合成法。A starting material or a catalyst material containing at least boron nitride and a starting material containing at least one member selected from the group of metals of group IVa, group Va, group VIa of the periodic table, silicon, aluminum, iron group metals, or compounds thereof, The product is obtained by contacting with borazine, a borazine derivative, and/or a compound of boron, hydrogen, and nitrogen that releases hydrogen and converts into boron nitride during thermal decomposition under pressure, and is treated under stable temperature and pressure conditions for cubic boron nitride. A method for synthesizing cubic boron nitride, which comprises recovering cubic boron nitride from a reaction product.