JPH0571526B2 - - Google Patents
Info
- Publication number
- JPH0571526B2 JPH0571526B2 JP13975789A JP13975789A JPH0571526B2 JP H0571526 B2 JPH0571526 B2 JP H0571526B2 JP 13975789 A JP13975789 A JP 13975789A JP 13975789 A JP13975789 A JP 13975789A JP H0571526 B2 JPH0571526 B2 JP H0571526B2
- Authority
- JP
- Japan
- Prior art keywords
- aln powder
- powder
- aln
- coating
- diamine
- 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.)
- Expired - Lifetime
Links
- 239000000843 powder Substances 0.000 claims description 124
- 238000000576 coating method Methods 0.000 claims description 46
- 239000011248 coating agent Substances 0.000 claims description 44
- 150000004985 diamines Chemical class 0.000 claims description 35
- 238000000034 method Methods 0.000 claims description 24
- 239000002245 particle Substances 0.000 claims description 23
- 229920006122 polyamide resin Polymers 0.000 claims description 22
- 239000002253 acid Substances 0.000 claims description 19
- 238000005121 nitriding Methods 0.000 claims description 15
- 238000006116 polymerization reaction Methods 0.000 claims description 8
- 230000001590 oxidative effect Effects 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 17
- 239000007791 liquid phase Substances 0.000 description 16
- 239000007822 coupling agent Substances 0.000 description 15
- 238000011282 treatment Methods 0.000 description 15
- 239000002002 slurry Substances 0.000 description 10
- -1 N-aminoethyl-aminoethyl Chemical group 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 9
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 8
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 8
- WMPOZLHMGVKUEJ-UHFFFAOYSA-N decanedioyl dichloride Chemical compound ClC(=O)CCCCCCCCC(Cl)=O WMPOZLHMGVKUEJ-UHFFFAOYSA-N 0.000 description 8
- 239000000126 substance Substances 0.000 description 8
- 230000000704 physical effect Effects 0.000 description 7
- 239000002904 solvent Substances 0.000 description 7
- 239000004094 surface-active agent Substances 0.000 description 7
- 238000000465 moulding Methods 0.000 description 6
- 230000003647 oxidation Effects 0.000 description 6
- 238000007254 oxidation reaction Methods 0.000 description 6
- 230000002829 reductive effect Effects 0.000 description 6
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 5
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000001035 drying Methods 0.000 description 5
- 238000010304 firing Methods 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- NAQMVNRVTILPCV-UHFFFAOYSA-N hexane-1,6-diamine Chemical compound NCCCCCCN NAQMVNRVTILPCV-UHFFFAOYSA-N 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000000178 monomer Substances 0.000 description 5
- 238000005245 sintering Methods 0.000 description 5
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 4
- 239000012298 atmosphere Substances 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000012153 distilled water Substances 0.000 description 4
- 239000010410 layer Substances 0.000 description 4
- 239000003960 organic solvent Substances 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 150000007513 acids Chemical class 0.000 description 3
- 229920006130 high-performance polyamide Polymers 0.000 description 3
- 230000002209 hydrophobic effect Effects 0.000 description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 3
- 230000001771 impaired effect Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 229910018626 Al(OH) Inorganic materials 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 229910001593 boehmite Inorganic materials 0.000 description 2
- VHRGRCVQAFMJIZ-UHFFFAOYSA-N cadaverine Chemical compound NCCCCCN VHRGRCVQAFMJIZ-UHFFFAOYSA-N 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 2
- 235000014113 dietary fatty acids Nutrition 0.000 description 2
- 229930195729 fatty acid Natural products 0.000 description 2
- 239000000194 fatty acid Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 2
- 238000003801 milling Methods 0.000 description 2
- 239000012046 mixed solvent Substances 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 239000005416 organic matter Substances 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 238000006068 polycondensation reaction Methods 0.000 description 2
- KIDHWZJUCRJVML-UHFFFAOYSA-N putrescine Chemical compound NCCCCN KIDHWZJUCRJVML-UHFFFAOYSA-N 0.000 description 2
- CXMXRPHRNRROMY-UHFFFAOYSA-N sebacic acid Chemical compound OC(=O)CCCCCCCCC(O)=O CXMXRPHRNRROMY-UHFFFAOYSA-N 0.000 description 2
- TYFQFVWCELRYAO-UHFFFAOYSA-N suberic acid Chemical compound OC(=O)CCCCCCC(O)=O TYFQFVWCELRYAO-UHFFFAOYSA-N 0.000 description 2
- 238000004381 surface treatment Methods 0.000 description 2
- XFNJVJPLKCPIBV-UHFFFAOYSA-N trimethylenediamine Chemical compound NCCCN XFNJVJPLKCPIBV-UHFFFAOYSA-N 0.000 description 2
- PWGJDPKCLMLPJW-UHFFFAOYSA-N 1,8-diaminooctane Chemical compound NCCCCCCCCN PWGJDPKCLMLPJW-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 1
- MXRIRQGCELJRSN-UHFFFAOYSA-N O.O.O.[Al] Chemical compound O.O.O.[Al] MXRIRQGCELJRSN-UHFFFAOYSA-N 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 229920001214 Polysorbate 60 Polymers 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- WNLRTRBMVRJNCN-UHFFFAOYSA-N adipic acid Chemical compound OC(=O)CCCCC(O)=O WNLRTRBMVRJNCN-UHFFFAOYSA-N 0.000 description 1
- 229960000250 adipic acid Drugs 0.000 description 1
- 235000011037 adipic acid Nutrition 0.000 description 1
- 150000005215 alkyl ethers Chemical class 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910001680 bayerite Inorganic materials 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- DDKMFOUTRRODRE-UHFFFAOYSA-N chloromethanone Chemical compound Cl[C]=O DDKMFOUTRRODRE-UHFFFAOYSA-N 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- YQLZOAVZWJBZSY-UHFFFAOYSA-N decane-1,10-diamine Chemical compound NCCCCCCCCCCN YQLZOAVZWJBZSY-UHFFFAOYSA-N 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 235000019441 ethanol Nutrition 0.000 description 1
- NKSJNEHGWDZZQF-UHFFFAOYSA-N ethenyl(trimethoxy)silane Chemical compound CO[Si](OC)(OC)C=C NKSJNEHGWDZZQF-UHFFFAOYSA-N 0.000 description 1
- PWSKHLMYTZNYKO-UHFFFAOYSA-N heptane-1,7-diamine Chemical compound NCCCCCCCN PWSKHLMYTZNYKO-UHFFFAOYSA-N 0.000 description 1
- SWFMWXHHVGHUFO-UHFFFAOYSA-N hexane-1,6-diamine Chemical compound NCCCCCCN.NCCCCCCN SWFMWXHHVGHUFO-UHFFFAOYSA-N 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 239000011268 mixed slurry Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- SXJVFQLYZSNZBT-UHFFFAOYSA-N nonane-1,9-diamine Chemical compound NCCCCCCCCCN SXJVFQLYZSNZBT-UHFFFAOYSA-N 0.000 description 1
- BDJRBEYXGGNYIS-UHFFFAOYSA-N nonanedioic acid Chemical compound OC(=O)CCCCCCCC(O)=O BDJRBEYXGGNYIS-UHFFFAOYSA-N 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- WLJVNTCWHIRURA-UHFFFAOYSA-N pimelic acid Chemical compound OC(=O)CCCCCC(O)=O WLJVNTCWHIRURA-UHFFFAOYSA-N 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 239000011253 protective coating Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000012756 surface treatment agent Substances 0.000 description 1
- 230000004580 weight loss Effects 0.000 description 1
Landscapes
- Ceramic Products (AREA)
Description
［産業上の利用分野］
本発明は直接窒化法により製造された窒化アル
ミニウム（以下「直接窒化AlN」と称す。）粉体
の表面被覆方法に係り、特に直接窒化AlN粉体
表面に水分や酸素に対する安定性を改善するため
の高特性ポリアミド樹脂被膜を高い密着性、接着
性にて、容易かつ効率的に形成することができる
直接窒化AlN粉体の表面被覆方法に関する。
［従来の技術及び先行技術］
AlN粉体は、大気中で熱力学的に極めて不安
定であり、特にその微粉体は容易に酸素や水分と
反応する。例えば、AlN粉体は、30℃、80％相
対湿度雰囲気下で40日程度保持すると、以下に示
す反応によりBayerite、Boehmite等の水酸化ア
ルミニウム（Al（OH）3）へと変化してしまう。
AlN＋3H2O→Al（OH）3＋NH3
このため、AlN粉体を保存する場合には、乾
燥後、容器に完全密封するか、N2又はNH3ガス
雰囲気下で保管する必要があり、管理が困難であ
る。仮に貯蔵時にAl（OH）3等への分解が実質的
に防止できたとしても、焼結体製造時の焼成前の
諸工程において分解不純物が発生することは避け
られない。即ち、水を媒質としてAlN粉体のス
ラリーを調製すると、AlNに一部生成したAl
（OH）3が混入するため、このようなスラリーを
成形、焼結した場合、焼成中にAl（OH）3がα−
アルミナ（Al2O3）に変化し、得られる焼結体中
のAl2O3が増加する。このため、熱伝導率等の焼
結体の特性を著しく損なう結果となる。このよう
なことから、従来においては、水系スラリーとす
ることができず、有機溶楳及び成形用バインダー
を用いて成形しているため、処理コストが高くつ
くという欠点があつた。
そこで、AlN粉体の安定化のために、粉体表
面に被覆膜を形成する提案がなされており、最近
では、AlN粉体表面に疎水性被膜を形成した後、
親水性被膜を形成したもの、具体的には第１次の
表面処理としてAlN粉体の表面を、無機、有機
の表面処理剤で覆い、水との反応性を抑制した
後、第２次の表面処理として、この第１次処理粉
体を、水を媒質とした界面活性剤中で処理し、水
に対する分散性を向上させたAlN粉体が提案さ
れている（特開昭62−207770号）。
しかしながら、特開昭62−207770号に開示され
るAlN粉体では
被膜の耐熱性が乏しい（200℃に耐えること
ができない。）。
被膜の機械的強度、耐薬品性、耐久性が十分
でない。
、より、ミルやスプレードライヤを用い
てミリングする場合等に被膜が破損してAlN
の水和が起こ易い。
等の欠点があつた。
上記従来の問題点を解決し、AlN粉体に、耐
熱性に優れ機械的強度が高く、著しく耐久性に優
れた、耐水保護被膜を形成し、AlN粉体の水系
での処理、成形を可能とし、もつて高特性AlN
焼結体を低コストで製造することができる、表面
被覆されたAlN粉体及びその製造方法として、
本出願人は粒子表面がポリアミド樹脂で被覆され
たAlN粉体、及び、このようなAlN粉体を製造
するにあたり、カツプリング剤等により疎水処理
されたAlN粉体の粒子表面に二塩基酸又はその
誘導体とジアミン類又はジアミン誘導体との重縮
合反応によりポリアミド樹脂被膜を生成させる方
法を見出し、先に特許出願した（特願昭63−
221871号。以下「先願」という。）。
［発明が解決しようとする課題］
上記先願の方法によれば、高特性ポリアミド樹
脂被膜が形成されたAlN粉体を容易かつ効率的
に製造することが可能とされるが、先願の方法に
より製造される表面被覆AlN粉体は、AlN粉体
粒子の表面にカツプリング剤層等の疎水処理剤層
を介してポリアミド樹脂被膜が形成されたもので
あり、、製造条件等によつても異なるが、カツプ
リング剤層に直接ポリアミド樹脂被膜が形成され
たAlN粉体よりも、むしろ、AlN粉体粒子の表
面に形成されたカツプリング剤層との間に、被膜
形成時の残留モノマーや有機溶媒の液相を包含し
てポリアミド樹脂被膜が形成されたAlN粉体と
なる。
即ち、先願の方法は、AlN粉体表面にて、例
えば二塩基酸又はその誘導体とジアミン類又はジ
アミン誘導体を液相にて反応させる、所謂液−液
重合であるため、形成されるポリアミド樹脂被膜
内に残留モノマーや有機溶媒の液相が包含され易
い。
このため、先願の方法により得られる表面被覆
AlN粉体では、次のような不具合がある。
成形時のプレス圧力により、被膜が破れて内
部の液相が浸出する。
このため、プレス収縮、焼成収縮が大きく、
成形性、焼結性が損なわれ、製品欠陥が生じ易
い。また、浸出した液相のために金型が汚染さ
れることから、金型の清掃が必要となり、生産
性が低下する。
形成される被膜自体が比較的厚い上に、被膜
内に液相を包含するため、表面被覆AlN粉体
に対する被膜及び液相の有機物の割合が、例え
ば約20％と、非常に多いものとなる。このた
め、使用薬剤量が多く原料コストが高騰する上
に、厚く形成された被膜及び液相の被膜層のた
めに、AlN粉体本来の特性が損なわれる場合
もある。
本発明は上記先願の問題点を解決し、特に直接
窒化AlN粉体表面に液相を包含することなく、
比較的薄いポリアミド被膜を容易かつ効率的に、
高い生産性にて形成することができる直接窒化
AlN粉体の表面被覆方法を提供することを目的
とする。
［課題を解決するための手段］
本発明の直接窒化AlN粉体の表面被覆方法は、
直接窒化法により製造されたAlN粉体の表面を
ポリアミド樹脂被膜で被覆するにあたり、AlN
粉体を酸化処理した後、該酸化処理されたAlN
粉体粒子の表面を二塩基酸又はその誘導体で被覆
し、該被覆処理されたAlN粉体をジアミン又は
ジアミン誘導体の溶液に分散させて、AlN粉体
の粒子表面で重合反応させることによりポリアミ
ド樹脂被膜を生成させることを特徴とする。
以下に本発明を詳細に説明する。
本発明の方法においては、まず、直接窒化
AlN粉体を酸化処理する。酸化処理は、空気等
の酸素含有ガス雰囲気にて、直接窒化AlN粉体
を加熱することにより容易に行なうことができ
る。酸化処理のための加熱条件は、後続の被覆処
理条件等によつても異なるが、一般には150〜250
℃で10〜60分とするのが好ましい。
次に酸化処理したAlN粉体粒子の表面を、二
塩基酸又はその誘導体で被覆する。具体的には、
AlN粉体と、カツプリング剤を添加した二塩基
酸又はその誘導体の溶液とを添加混合し、得られ
た混合スラリーを急熱乾燥するなどの方法で、溶
媒を揮発除去する。
本発明において、カツプリング剤としては具体
的には、KBM1003（信越化学工業(株)製、ビニル
トリメトキシシラン）、KR44（味の素(株)製、イソ
プロピルトリ（Ｎ−アミノエチル−アミノエチ
ル）チタネート）、AL−Ｍ（味の素(株)製、アセト
アルコキシアルミニウムジイソプロピレート）等
を用いることができる。
なお、カツプリング剤としてチタネート系、あ
るいはアルミニウム系のものを用いると、シラン
系のものを用いた場合よりもAlN焼結体の熱伝
導率が高くなる。
また、二塩基酸又はその誘導体としては、１，
８−オクタンジカルボニルクロリド、１，４−ブ
タンジカルボン酸、１，７−ヘプタンジカルボン
酸、１，５−ペンタンジカルボン酸、１，６−ヘ
キサンジカルボン酸及びその塩化物等を用いるこ
とができる。
このような二塩基酸又はその誘導体を溶解させ
る溶媒としては、シクロヘキサン、エチルアルコ
ール、アセトン、ヘキサン、メチルアルコール、
クロロホルム等の１種又は２種以上の有機溶媒が
挙げられる。
カツプリング剤の使用量は、AlN粉体100ｇに
対して1.0〜4.0ml程度とするのが好ましい。ま
た、二塩基酸又はその誘導体の溶液の濃度及び該
溶液と添加混合するAlN粉体の割合等は、製造
する表面被覆AlN粉体の皮膜量等によつても異
なるが、通常の場合、0.1〜0.3ｍol／程度の二
塩基酸又はその誘導体の溶液100mlに対して40〜
60ｇのAlN粉体を混合するのが好ましい。
なお、本発明においては、カツプリング剤を用
いることなく二塩基酸又はその誘導体で被覆処理
することもできる。しかしながら、AlN粉体の
表面は親水性であるため、被覆処理に際して二塩
基酸又はその誘導体の溶液に対する濡れ性が悪
く、AlN粉体の分散性が悪いことから、形成さ
れる被膜も不均一なものとなり易い。従つて、本
発明においてはカツプリング剤を用いるのが好ま
しい。
このようにして被覆処理されたAlN粉体は、
次いで、ジアミン又はジアミン誘導体の溶液に分
散させて、AlN粉体の粒子表面で重合反応させ
ることにより、ポリアミド樹脂被膜を生成させ
る。
具体的には、界面活性剤を加えた水に、上記被
覆処理されたAlN粉体を分散させてスラリーと
し、このスラリーにジアミン又はジアミン誘導体
の溶液を添加して混合撹拌する。
界面活性剤としては、HLB値の高いノニオン
系界面活性剤、例えば、ポリオキシエチレンアル
キルエーテル、ポリオキシエチレンアルキルアリ
ルエーテル、ポリオキシエチレン誘導体、ポリオ
キシエチレンゾルビタン脂肪酸エステル、ポリオ
キシエチレン脂肪酸エステル等を用いることがで
きる。
また、ジアミン又はジアミン誘導体としては、
１，６−ジアミノヘキサン、１，７−ジアミノヘ
プタン、１，８−ジアミノオクタン、１，９−ジ
アミノノナン、１，10−ジアミノデカン、エチレ
ンジアミン、トリメチレンジアミン、テトラメチ
レンジアミン、ペンタメチレンジアミン及びその
誘導体等を用いることができる。
このようなジアミン又はジアミン誘導体を溶解
させる溶媒としては、水が挙げられる。
界面活性剤の使用量は、AlN粉体100ｇに対し
て５〜10ml程度とするのが好ましい。また、ジア
ミン又はジアミン誘導体の溶液の濃度及び該溶液
と添加混合するAlN粉体の割合等は、AlN粉体
粒子の表面に付着している二塩基酸又はその誘導
体と重合反応を起こすに十分な量のジアミン又は
ジアミン誘導体が添加される量であれば良く、製
造する表面被覆AlN粉体の被膜量等によつても
異なるが、通常の場合、0.02〜0.05ｍol／程度
のジアミン又はジアミン誘導体の溶液100mlに対
して50〜100ｇの被覆処理されたAlN粉体を混合
するのが好ましい。
このようにして、カツプリング剤と二塩基酸又
はその誘導体とで被覆したAlN粉体をジアミン
又はジアミン誘導体の溶液に分散させることによ
り、AlN粉体の粒子表面で二塩基酸又はその誘
導体とジアミン又はジアミン誘導体が重縮合反応
してポリアミド樹脂被膜を生成する。
反応終了後、スラリーを急熱乾燥するなどの方
法により水等の溶媒を揮発させて、ポリアミド樹
脂被膜が形成された表面被覆AlN粉体を得る。
このようにして得られる表面被覆AlN粉体は、
表面の少なくとも一部にカツプリング剤が付着し
たAlN粉体粒子の表面に液相を殆ど包含するこ
となくポリアミド樹脂被膜が密着性良く形成され
たAlN粉体である。
なお、本発明の方法は、成形、焼成材料として
用いるAlN粉体を製造する場合には、予め所定
量のY2O3粉体等の焼結助剤を混合したAlN粉体
に適用することができることは言うまでもない。
［作用］
本発明の方法によれば、先願の液−液重合とは
異なり、AlN粉体粒子表面の二塩基酸又はその
誘導体と、溶液中のジアミン又はジアミン誘導体
とを反応させる、いわば固−液重合によりポリア
ミド樹脂被膜を形成することにより、被膜内に未
反応モノマーや溶媒等の液相を包含しない表面被
覆AlN粉体を得ることができる。
このため、表面被覆AlN粉体に対する被膜の
有機物量が約５％と著しく低減され、AlN粉体
本来の特性を損なうことなく、耐水性、耐熱性に
優れ、かつ機械的強度も著しく高い被膜を密着性
良く、薄く均一な膜厚で、しかもほぼ単粒子毎の
被覆となるように形成することが可能とされる。
また、AlN粉体粒子表面に形成される被膜量
は、二塩基酸又はその誘導体の付着量、並びに、
ジアミン又はジアミン誘導体の使用量等により容
易に調整することができる。
ところで、一般に提供されるAlN粉体には、
還元窒化法によるAlN粉体、即ち、Al2O3をN2雰
囲気中にて炭素で還元することによりAlNとす
る方法により製造されたAlN粉体と、Alを直接
窒素で窒化して得られた直接窒化AlN粉体とが
ある。
これらのうち、還元窒化法によるAlN粉体は、
これを直接二塩基酸又はその誘導体で被覆し、ジ
アミン又はジアミン誘導体の溶液に分散させるこ
とにより、AlN粉体の粒子表面にポリアミド樹
脂被膜を生成させることができる。即ち、還元窒
化法によるAlN粉体は、その製造工程上、粒子
表面にOH基等が残留するため、粒子表面のOH
基等によりポリアミド樹脂被膜を密着性良く形成
することができる。
一方、直接窒化AlN粉体では、Alを直接窒化
するため、粒子表面にはOH基やＯ原子等は存在
せず、表面の極性は非常に大きなものとなつてい
る。このため、直接窒化AlN粉体を直接二塩基
酸又はその誘導体で被覆してジアミン又はジアミ
ン誘導体の溶液に分散させても、AlN粉体の粒
子表面にポリアミド樹脂被膜を密着性、均一性良
く生成させることはできず、被膜剥離が起こるな
どの問題が生じる。
これに対して、本発明の方法に従つて、ポリア
ミド樹脂被膜の形成に先立つて、予め直接窒化
AlN粉体を酸化処理することにより、直接窒化
AlN粉体の粒子表面にＯ及び／又はOH基が導入
され、これによりポリアミド樹脂被膜を密着性、
均一性良く形成することが可能とされる。
［実施例］
以下に実施例及び比較例を挙げて本発明をより
具体的に説明するが、本発明はその要旨を超えな
い限り、以下の実施例に限定されるものではな
い。
なお、以下の実施例及び比較例において、用い
た試薬は下記の通りである。
使用試薬
１，８−オクタンジカルボニルクロリド：塩
化セバコイル（和光純薬(株)製）ClCO
（CH2）8COCl＝239.1
１，６−ジアミノヘキサン（ヘキサメチレン
ジアミン）（和光純薬(株)製）
NH2（CH2）6NH2＝116.21
クロロホルム（和光純薬(株)製）
CHCl3＝119
シクロヘキサン（和光純薬(株)製）
C6H12＝84.2
界面活性剤
エマルゲンＡ−60（(株)花王製）
（ポリオキシエチレン誘導体HLB＝12.8）
カツプリング剤
KBM1003（信越化学工業(株)製）
CH2CHSi（OCH3）3＝148.2
また、原料のAlN粉体としては、次のを、
焼結助剤としては次のを用いた。
直接窒化AlN粉体：
「TOYALNITE、Ｆ」（東洋アルミニウム
(株)製）
Y2O3
（信越化学工業(株)製）
実施例 １
直接窒化AlN粉体15ｇをホツトプレートに展
開して200℃15分間加熱することにより酸化処理
した。
別に、塩化セバコイル25ｇをシクロヘキサン
500mlに溶かし、溶液Ａ（0.2ｍol／）を調製し
た。また、ヘキサメチレンジアミン2.32ｇを蒸留
水500mlに溶かし、溶液Ｂ（0.04ｍol／）を調製
した。
酸化処理したAlN粉体14.25ｇ及び焼結助剤
Y2O3粉体0.75ｇをボールミルにて混合すると同
時に、塩化セバコイルを固定するために、溶液Ａ
を23ml（塩化セバコイル4.6×10-3ｍol）、シクロ
ヘキサンを10ml、カツプリング剤を150μ添加
し、24時間混合した。得られたスラリーをホツト
プレート120℃にて急熱乾燥を行ない、シクロヘ
キサンを揮発させて塩化セバコイルで被覆した
AlN粉体を得た。次いで、得られたAlN粉体を
界面活性剤１mlを加えた蒸留水100mlに分散させ
てスラリーＣを得た。
次に、AlN粉体表面の塩化セバコイルとヘキ
サメチンジアミンとを重合させるために、スラリ
ーＣに溶液Ｂを10〜20ml添加し、数分程度撹拌し
た。
反応によりAlN粉体粒子表面にポリアミド樹
脂被膜が生成したので、得られた表面被覆AlN
粉体を水から分離するため、反応液をホツトプレ
ート200℃にて急熱乾燥した。
得られた表面被覆AlN粉体について、下記方
法により物性及び特性を調べ、結果を第１表に示
した。
有機分量の測定
表面被覆AlN粉体１ｇを用いて、大気中、600
℃で１時間の焼成を行ない、焼成減量より有機分
量の測定を行なつた。
成形性、焼成体の諸物性
表面被覆AlN粉体を12mmφ及び30mmφの成形
型を用いて1000Kgｆ／cm2でプレス成形し、窒素雰
囲気中、1880℃で１時間焼成して焼成体を得た。
この時の成形性の良否を◎、○、△、×の４段階
で評価し、また、得られた焼成体について諸物性
を測定した。
熱伝導率
上記で得られた焼成体について、真空理工社製
「レーザーフラツシユ熱定数測定装置（TC−
7000）」を用いて測定した。
電気的特性
上記で得られた焼成体について、YHP（横河ヒ
ユーレツトパツカード）社製「4192Aインピーダ
ンスアナライザー」を用いて1MHzにて測定した。
比較例 １
直接窒化AlN粉体14.25ｇ、焼結助剤Y2O3粉体
0.75ｇ及びバインダー（第一工業製薬社製
「G7211」）0.60ｇをシクロヘキサン30mlを溶媒と
して、24時間混合した。
これをホツトプレートに展開し、200℃で急熱
乾燥処理を施して混合粉体を得た。
得られた粉体について、実施例１と同様にして
物性及び特性を調べ、結果を第１表に示した。
比較例 ２
酸化処理を行なわなかつたこと以外は実施例１
と同様にして得られた粉体について、同様に物性
及び特性を調べ、結果を第１表に示した。
比較例 ３
（先願の方法）
塩化セバコイル25ｇをシクロヘキサン／クロロ
ホルム＝３：１（体積比）の混合溶媒500mlに溶解
して、0.2ｍol／の溶液を調製した。別に、
ヘキサメチレンジアミン2.32ｇを蒸留水500mlに
溶解して、0.04ｍol／の溶液を調製した。
直接窒化AlN粉体14.25ｇ及び焼結助剤Y2O3粉
体0.75ｇをカツプリング剤約150μを添加してア
セトン30ml中で24時間混合して疎水処理した。混
合後、得られたスラリーを、ホツトプレートを用
いて120℃で急熱乾燥を行ない、得られた乾燥粉
体を溶液10〜20mlに分散させた。次いで、分散
液を、界面活性剤１mlを含む蒸留水30mlに乳化さ
せ、乳化液に溶液を10〜20ml加え、重合を起こ
させた。その後、混合溶媒（シクロヘキサン：ク
ロロホルム＝３：１体積比）を加えて反応を停止
させ、ホツトプレート約200℃にて乾燥処理を行
なつて、表面比覆AlN粉体を得た。
得られた粉体について、実施例１と同様にして
物性及び特性を調べ、結果を第１表に示した。
[Industrial Field of Application] The present invention relates to a method for coating the surface of aluminum nitride (hereinafter referred to as "direct nitrided AlN") powder produced by a direct nitriding method, and in particular, the present invention relates to a method for coating the surface of aluminum nitride (hereinafter referred to as "direct nitrided AlN") powder. This invention relates to a method for directly coating the surface of nitrided AlN powder, which enables the easy and efficient formation of a high-performance polyamide resin film with high adhesion and adhesion to improve the stability of the powder. [Prior Art and Prior Art] AlN powder is thermodynamically extremely unstable in the atmosphere, and in particular, its fine powder easily reacts with oxygen and moisture. For example, if AlN powder is kept in an atmosphere of 30° C. and 80% relative humidity for about 40 days, it will change to aluminum hydroxide (Al(OH) 3 ) such as Bayerite and Boehmite through the reaction shown below. AlN + 3H 2 O → Al (OH) 3 + NH 3 Therefore, when storing AlN powder, it must be completely sealed in a container after drying, or stored under an N 2 or NH 3 gas atmosphere, and controlled. is difficult. Even if decomposition into Al(OH) 3 etc. can be substantially prevented during storage, it is inevitable that decomposed impurities will be generated in the various steps before firing during the production of the sintered body. That is, when a slurry of AlN powder is prepared using water as a medium, some of the Al formed in AlN
(OH) 3 is mixed in, so when such a slurry is formed and sintered, Al(OH) 3 is mixed with α-
It changes to alumina (Al 2 O 3 ), and the amount of Al 2 O 3 in the obtained sintered body increases. Therefore, the properties of the sintered body such as thermal conductivity are significantly impaired. For this reason, in the past, it was not possible to form an aqueous slurry, and molding was performed using an organic solvent and a molding binder, which resulted in a drawback of high processing costs. Therefore, in order to stabilize AlN powder, it has been proposed to form a coating film on the surface of the powder, and recently, after forming a hydrophobic film on the surface of AlN powder,
After forming a hydrophilic film, specifically, the surface of AlN powder is coated with an inorganic or organic surface treatment agent as the first surface treatment to suppress reactivity with water. As a surface treatment, AlN powder has been proposed in which this primary treated powder is treated in a water-based surfactant to improve its dispersibility in water (Japanese Patent Laid-Open No. 62-207770). ). However, the AlN powder disclosed in JP-A No. 62-207770 has a coating with poor heat resistance (cannot withstand temperatures of 200°C). Mechanical strength, chemical resistance, and durability of the film are insufficient. , when milling using a mill or spray dryer, the coating is damaged and the AlN
hydration is likely to occur. There were other drawbacks. By solving the above conventional problems, we have formed a water-resistant protective coating on AlN powder that has excellent heat resistance, high mechanical strength, and outstanding durability, making it possible to process and mold AlN powder in aqueous systems. Also, high-performance AlN
As a surface-coated AlN powder and its manufacturing method that can produce a sintered body at low cost,
The applicant has developed AlN powder whose particle surface is coated with polyamide resin, and in producing such AlN powder, a dibasic acid or its We discovered a method for producing a polyamide resin coating through a polycondensation reaction between derivatives and diamines or diamine derivatives, and filed a patent application earlier (Japanese Patent Application No. 1983-
No. 221871. Hereinafter referred to as "prior application". ). [Problems to be Solved by the Invention] According to the method of the earlier application, it is possible to easily and efficiently produce AlN powder on which a high-performance polyamide resin coating is formed. The surface-coated AlN powder manufactured by is a polyamide resin coating formed on the surface of AlN powder particles via a hydrophobic treatment agent layer such as a coupling agent layer, and the surface coating may vary depending on manufacturing conditions, etc. However, rather than AlN powder having a polyamide resin coating formed directly on the coupling agent layer, there is a possibility that residual monomers and organic solvents may be present between the coupling agent layer formed on the surface of the AlN powder particles during coating formation. The resulting AlN powder contains a liquid phase and has a polyamide resin coating formed thereon. That is, the method of the prior application is a so-called liquid-liquid polymerization in which, for example, a dibasic acid or its derivative and a diamine or a diamine derivative are reacted in a liquid phase on the surface of the AlN powder. Residual monomers and liquid phases of organic solvents are likely to be included in the coating. Therefore, the surface coating obtained by the method of the earlier application
AlN powder has the following problems. The press pressure during molding causes the coating to break and the internal liquid phase leaks out. For this reason, press shrinkage and firing shrinkage are large.
Formability and sinterability are impaired, and product defects are likely to occur. In addition, the mold is contaminated by the leached liquid phase, requiring cleaning of the mold, which reduces productivity. Since the formed film itself is relatively thick and contains a liquid phase, the ratio of organic matter in the film and liquid phase to the surface-coated AlN powder is extremely high, for example, about 20%. . For this reason, the amount of chemicals used is large and the cost of raw materials increases, and the inherent properties of the AlN powder may be impaired due to the thick coating and liquid phase coating layer. The present invention solves the problems of the above-mentioned prior application, and in particular does not include a liquid phase directly on the surface of the nitrided AlN powder.
Easily and efficiently deposit relatively thin polyamide coatings.
Direct nitriding allows formation with high productivity
The purpose of this paper is to provide a method for surface coating AlN powder. [Means for solving the problem] The method for surface coating direct nitrided AlN powder of the present invention includes:
When coating the surface of AlN powder produced by direct nitriding with a polyamide resin film, AlN
After oxidizing the powder, the oxidized AlN
A polyamide resin is produced by coating the surface of powder particles with a dibasic acid or its derivative, dispersing the coated AlN powder in a solution of diamine or diamine derivative, and causing a polymerization reaction on the particle surface of the AlN powder. It is characterized by producing a film. The present invention will be explained in detail below. In the method of the present invention, first, direct nitriding is performed.
Oxidation treatment of AlN powder. The oxidation treatment can be easily performed by directly heating the nitrided AlN powder in an oxygen-containing gas atmosphere such as air. The heating conditions for oxidation treatment vary depending on the subsequent coating treatment conditions, etc., but generally 150 to 250
Preferably, the heating time is 10 to 60 minutes at ℃. Next, the surface of the oxidized AlN powder particles is coated with a dibasic acid or its derivative. in particular,
AlN powder and a solution of a dibasic acid or a derivative thereof to which a coupling agent has been added are added and mixed, and the resulting mixed slurry is evaporated and removed by a method such as rapid heat drying. In the present invention, specific coupling agents include KBM1003 (manufactured by Shin-Etsu Chemical Co., Ltd., vinyltrimethoxysilane) and KR44 (manufactured by Ajinomoto Co., Ltd., isopropyl tri(N-aminoethyl-aminoethyl) titanate). , AL-M (manufactured by Ajinomoto Co., Ltd., acetalkoxyaluminum diisopropylate), etc. can be used. Note that when a titanate-based or aluminum-based coupling agent is used, the thermal conductivity of the AlN sintered body becomes higher than when a silane-based coupling agent is used. In addition, as dibasic acids or derivatives thereof, 1,
8-octanedicarboxylic acid, 1,4-butanedicarboxylic acid, 1,7-heptanedicarboxylic acid, 1,5-pentanedicarboxylic acid, 1,6-hexanedicarboxylic acid and chlorides thereof, etc. can be used. Solvents for dissolving such dibasic acids or derivatives thereof include cyclohexane, ethyl alcohol, acetone, hexane, methyl alcohol,
Examples include one or more organic solvents such as chloroform. The amount of coupling agent used is preferably about 1.0 to 4.0 ml per 100 g of AlN powder. In addition, the concentration of the dibasic acid or its derivative solution and the proportion of AlN powder added and mixed with the solution vary depending on the amount of coating of the surface-coated AlN powder to be manufactured, but in the normal case, 0.1 ~40~ for 100ml of solution of ~0.3mol/dibasic acid or its derivative
Preferably, 60 g of AlN powder is mixed. In addition, in the present invention, coating treatment with a dibasic acid or its derivative can also be performed without using a coupling agent. However, since the surface of AlN powder is hydrophilic, it has poor wettability with solutions of dibasic acids or its derivatives during coating treatment, and the dispersibility of AlN powder is poor, resulting in non-uniform coatings. It's easy to become a thing. Therefore, it is preferable to use a coupling agent in the present invention. The AlN powder coated in this way is
Next, a polyamide resin coating is produced by dispersing the AlN powder in a solution of diamine or diamine derivative and causing a polymerization reaction on the surface of the AlN powder particles. Specifically, the coated AlN powder is dispersed in water to which a surfactant has been added to form a slurry, and a solution of diamine or diamine derivative is added to this slurry and mixed and stirred. Examples of surfactants include nonionic surfactants with high HLB values, such as polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene derivatives, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester, etc. can be used. In addition, as diamine or diamine derivative,
1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine and derivatives thereof etc. can be used. Water is an example of a solvent for dissolving such diamines or diamine derivatives. The amount of surfactant used is preferably about 5 to 10 ml per 100 g of AlN powder. In addition, the concentration of the diamine or diamine derivative solution and the proportion of AlN powder added and mixed with the solution should be set to a level sufficient to cause a polymerization reaction with the dibasic acid or its derivative attached to the surface of the AlN powder particles. It is sufficient that the amount of diamine or diamine derivative is added, and it varies depending on the amount of coating of the surface-coated AlN powder to be produced, but in normal cases, about 0.02 to 0.05 mol/of diamine or diamine derivative is added. Preferably, 50 to 100 g of coated AlN powder is mixed per 100 ml of solution. In this way, by dispersing AlN powder coated with a coupling agent and a dibasic acid or its derivative in a solution of diamine or diamine derivative, the dibasic acid or its derivative and diamine or The diamine derivative undergoes a polycondensation reaction to produce a polyamide resin coating. After the reaction is completed, the solvent such as water is evaporated by drying the slurry under rapid heat to obtain a surface-coated AlN powder on which a polyamide resin film is formed. The surface-coated AlN powder obtained in this way is
This is an AlN powder in which a polyamide resin coating is formed with good adhesion on the surface of AlN powder particles having a coupling agent attached to at least a portion of the surface thereof, with almost no liquid phase included. In addition, when producing AlN powder to be used as a molding or firing material, the method of the present invention can be applied to AlN powder mixed with a predetermined amount of a sintering aid such as Y 2 O 3 powder in advance. Needless to say, it can be done. [Function] Unlike the liquid-liquid polymerization of the previous application, the method of the present invention allows the dibasic acid or its derivative on the surface of the AlN powder particles to react with the diamine or diamine derivative in the solution, so to speak. - By forming a polyamide resin film by liquid polymerization, it is possible to obtain a surface-coated AlN powder that does not contain liquid phases such as unreacted monomers and solvents within the film. For this reason, the amount of organic matter in the coating is significantly reduced to approximately 5% compared to the surface-coated AlN powder, and a coating with excellent water resistance, heat resistance, and extremely high mechanical strength can be created without impairing the original properties of AlN powder. It is possible to form a film with good adhesion, a thin and uniform thickness, and to cover almost every single particle. In addition, the amount of coating formed on the surface of AlN powder particles depends on the amount of attached dibasic acid or its derivative, and
It can be easily adjusted by adjusting the amount of diamine or diamine derivative used. By the way, commonly available AlN powder includes:
AlN powder produced by the reductive nitriding method, that is, AlN powder produced by reducing Al 2 O 3 with carbon in an N 2 atmosphere to produce AlN, and AlN powder produced by directly nitriding Al with nitrogen. There is also direct nitriding AlN powder. Among these, AlN powder produced by the reductive nitriding method is
By directly coating this with a dibasic acid or its derivative and dispersing it in a solution of diamine or diamine derivative, a polyamide resin coating can be formed on the particle surface of AlN powder. In other words, AlN powder produced by the reductive nitriding method has OH groups remaining on the particle surface due to the manufacturing process.
A polyamide resin coating can be formed with good adhesion by using a group or the like. On the other hand, in direct nitriding AlN powder, since Al is directly nitrided, there are no OH groups or O atoms on the particle surface, and the surface polarity is extremely high. Therefore, even if directly nitrided AlN powder is directly coated with a dibasic acid or its derivative and dispersed in a solution of diamine or diamine derivative, a polyamide resin film is formed on the particle surface of AlN powder with good adhesion and uniformity. However, problems such as film peeling occur. In contrast, according to the method of the present invention, prior to the formation of the polyamide resin film, the film is directly nitrided in advance.
Direct nitriding by oxidizing AlN powder
O and/or OH groups are introduced to the particle surface of AlN powder, which improves the adhesion of the polyamide resin coating.
It is possible to form the film with good uniformity. [Examples] The present invention will be described in more detail with reference to Examples and Comparative Examples below, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. In addition, in the following examples and comparative examples, the reagents used are as follows. Reagent used: 1,8-octanedicarbonyl chloride: Sebacoyl chloride (manufactured by Wako Pure Chemical Industries, Ltd.) ClCO
(CH 2 ) 8 COCl = 239.1 1,6-diaminohexane (hexamethylene diamine) (manufactured by Wako Pure Chemical Industries, Ltd.) NH 2 (CH 2 ) 6 NH 2 = 116.21 Chloroform (manufactured by Wako Pure Chemical Industries, Ltd.) CHCl 3 = 119 cyclohexane (manufactured by Wako Pure Chemical Industries, Ltd.) C 6 H 12 = 84.2 Surfactant Emulgen A-60 (manufactured by Kao Corporation) (polyoxyethylene derivative HLB = 12.8) Coupling agent KBM1003 (manufactured by Shin-Etsu Chemical Co., Ltd.) Co., Ltd.) CH 2 CHSi (OCH 3 ) 3 = 148.2 In addition, as the raw material AlN powder, the following:
The following was used as the sintering aid. Direct nitriding AlN powder: "TOYALNITE, F" (Toyo Aluminum
(manufactured by Shin-Etsu Chemical Co., Ltd.) Y 2 O 3 (manufactured by Shin-Etsu Chemical Co., Ltd.) Example 1 15 g of direct nitrided AlN powder was spread on a hot plate and oxidized by heating at 200° C. for 15 minutes. Separately, add 25 g of sebacoyl chloride to cyclohexane.
Solution A (0.2 mol/) was prepared by dissolving it in 500 ml. Further, 2.32 g of hexamethylene diamine was dissolved in 500 ml of distilled water to prepare solution B (0.04 mol/). 14.25g of oxidized AlN powder and sintering aid
At the same time, 0.75 g of Y 2 O 3 powder was mixed in a ball mill, and at the same time, solution A was added to fix sebacoyl chloride.
23 ml (4.6 x 10 -3 mol of sebacoyl chloride), 10 ml of cyclohexane and 150 μ of a coupling agent were added and mixed for 24 hours. The resulting slurry was rapidly dried on a hot plate at 120°C to volatilize the cyclohexane and coated with sebacoyl chloride.
AlN powder was obtained. Next, the obtained AlN powder was dispersed in 100 ml of distilled water to which 1 ml of a surfactant was added to obtain slurry C. Next, in order to polymerize sebacoyl chloride and hexamethine diamine on the surface of the AlN powder, 10 to 20 ml of solution B was added to slurry C and stirred for several minutes. Due to the reaction, a polyamide resin film was formed on the surface of the AlN powder particles, so the resulting surface-coated AlN
In order to separate the powder from water, the reaction solution was rapidly dried on a hot plate at 200°C. The physical properties and characteristics of the obtained surface-coated AlN powder were investigated by the following method, and the results are shown in Table 1. Measurement of organic content Using 1 g of surface-coated AlN powder, 600
Firing was carried out at ℃ for 1 hour, and the organic content was measured from the weight loss on calcination. Formability, physical properties of fired body The surface-coated AlN powder was press-molded at 1000 Kgf/cm 2 using molds of 12 mmφ and 30 mmφ, and fired at 1880° C. for 1 hour in a nitrogen atmosphere to obtain a fired body.
The quality of the moldability at this time was evaluated in four stages: ◎, ◯, △, and ×, and various physical properties of the obtained fired body were measured. Thermal conductivity The fired body obtained above was measured using the Laser Flash Thermal Constant Measuring Device (TC-
7000). Electrical Properties The fired body obtained above was measured at 1 MHz using a "4192A Impedance Analyzer" manufactured by YHP (Yokogawa Heuretsu Card). Comparative example 1 Direct nitriding AlN powder 14.25g, sintering aid Y 2 O 3 powder
0.75 g and 0.60 g of binder (“G7211” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were mixed for 24 hours using 30 ml of cyclohexane as a solvent. This was spread on a hot plate and subjected to rapid heat drying treatment at 200°C to obtain a mixed powder. The physical properties and characteristics of the obtained powder were investigated in the same manner as in Example 1, and the results are shown in Table 1. Comparative Example 2 Example 1 except that oxidation treatment was not performed
The physical properties and characteristics of the powder obtained in the same manner as above were similarly investigated, and the results are shown in Table 1. Comparative Example 3 (Method of the prior application) 25 g of sebacoyl chloride was dissolved in 500 ml of a mixed solvent of cyclohexane/chloroform = 3:1 (volume ratio) to prepare a 0.2 mol/solution. Separately,
2.32 g of hexamethylene diamine was dissolved in 500 ml of distilled water to prepare a 0.04 mol/solution. 14.25 g of directly nitrided AlN powder and 0.75 g of sintering aid Y 2 O 3 powder were mixed for 24 hours in 30 ml of acetone with the addition of about 150 μ of a coupling agent for hydrophobic treatment. After mixing, the obtained slurry was rapidly dried at 120° C. using a hot plate, and the obtained dry powder was dispersed in 10 to 20 ml of solution. Next, the dispersion was emulsified in 30 ml of distilled water containing 1 ml of surfactant, and 10 to 20 ml of the solution was added to the emulsion to cause polymerization. Thereafter, a mixed solvent (cyclohexane:chloroform = 3:1 volume ratio) was added to stop the reaction, and drying was performed on a hot plate at about 200°C to obtain a surface-specific AlN powder. The physical properties and characteristics of the obtained powder were investigated in the same manner as in Example 1, and the results are shown in Table 1.
【表】
第１表より次のことが明らかである。
比較例１で得られる粉体では、成形体の密度が
低く、このため焼成体の強度が低い。
比較例２で得られる粉体では、焼結性が悪く、
気孔率、吸水率が著しく大きい。また、熱伝導率
は著しく小さい。これは、酸化処理を行なつてい
ないために、AlN粉体粒子表面のポリアミド樹
脂被膜が一部剥れ落ち、良好な表面被覆がなされ
ていないため被膜破壊が生じ、ベーマイトが生成
したためである。
比較例３で得られる粉体では、未反応のモノマ
ー及び溶媒からなる液相が包含されているため有
機分量が高い。このため使用薬剤量が多く、ま
た、成形時において液相部の流出による生産性の
低下の問題がある。
これに対して、本発明の方法により得られる表
面被覆AlN粉体によれば、良好な成形性にて、
気孔率が低く、高強度の成形体及び焼成体を高い
生産性で得ることができる。しかも、液相分の包
含の問題がないため、使用薬剤量も比較例３の方
法に比べて約1/4となり、原料コストも軽減され
る。
実施例 ２〜４
直接窒化AlN粉体の酸化処理時間を第２表に
示す時間とし、溶液Ａの使用量を変えて塩化セバ
コイル添加量を第２表に示す量としたこと以外は
実施例１と同様にして表面被覆AlN粉体を得、
同様に物性及び特性を調べた。結果を第２表に示
す。[Table] The following is clear from Table 1. In the powder obtained in Comparative Example 1, the density of the molded body is low, and therefore the strength of the fired body is low. The powder obtained in Comparative Example 2 had poor sinterability;
The porosity and water absorption rate are extremely high. Also, the thermal conductivity is extremely low. This is because the polyamide resin coating on the surface of the AlN powder particles partially peeled off due to the lack of oxidation treatment, and the lack of a good surface coating caused the coating to break and generate boehmite. The powder obtained in Comparative Example 3 has a high organic content because it contains a liquid phase consisting of unreacted monomers and solvent. Therefore, the amount of chemicals used is large, and there is also the problem of reduced productivity due to outflow of the liquid phase during molding. In contrast, the surface-coated AlN powder obtained by the method of the present invention has good moldability and
Molded bodies and fired bodies with low porosity and high strength can be obtained with high productivity. Moreover, since there is no problem of inclusion of liquid phase components, the amount of chemicals used is about 1/4 compared to the method of Comparative Example 3, and the cost of raw materials is also reduced. Examples 2 to 4 Example 1 except that the oxidation treatment time of the direct nitrided AlN powder was set to the time shown in Table 2, the amount of solution A used was changed, and the amount of sebacoil chloride added was set to the amount shown in Table 2. Obtain surface-coated AlN powder in the same manner as
The physical properties and characteristics were similarly investigated. The results are shown in Table 2.
【表】
［発明の効果］
以上詳述した通り、本発明の直接窒化AlN粉
体の表面被覆方法によれば、耐水性、耐熱性、機
械的強度に著しく優れ、AlN粉体粒子を十分に
保護することができる高特性ポリアミド樹脂被覆
層を容易かつ低コストに、効率的に直接窒化
AlN粉体粒子表面に形成することができる。
本発明により製造された表面被覆AlN粉体に
よれば、水系処理、加熱処理、ミリング処理等の
処理工程において保護被膜が破壊されることがな
いため、これらの処理工程でAlN粉体がAl
（OH）3に変化するのが防止され、Al2O3の生成の
ない、熱伝導率が高く、諸特性に優れたAlN粉
体を得ることが可能とされる。しかも、ポリアミ
ド樹脂被膜の内部に、未反応モノマーや溶媒の液
相が包含されていないことから、その成形、焼成
に際しては、液相の浸出によるプレス収縮や焼成
収縮の問題もなく、生産性も大幅に向上する。[Table] [Effects of the Invention] As detailed above, according to the method of directly coating the surface of nitrided AlN powder of the present invention, it has excellent water resistance, heat resistance, and mechanical strength, and the AlN powder particles can be coated sufficiently. Easy, low-cost, and efficient direct nitriding of high-performance polyamide resin coating layers that can be protected.
It can be formed on the surface of AlN powder particles. According to the surface-coated AlN powder produced according to the present invention, the protective film is not destroyed in treatment steps such as water-based treatment, heat treatment, and milling treatment.
It is said that it is possible to obtain AlN powder that is prevented from changing to (OH) 3 , does not generate Al 2 O 3 , has high thermal conductivity, and has excellent various properties. Moreover, since the liquid phase of unreacted monomers and solvents is not contained inside the polyamide resin coating, there is no problem of press shrinkage or baking shrinkage due to leaching of the liquid phase during molding and firing, and productivity is improved. Significantly improved.
Claims (1)
面をポリアミド樹脂被膜で被覆するにあたり、
AlN粉体を酸化処理した後、該酸化処理された
AlN粉体粒子の表面を二塩基酸又はその誘導体
で被覆し、該被覆処理されたAlN粉体をジアミ
ン又はジアミン誘導体の溶液に分散させて、
AlN粉体の粒子表面で重合反応させることによ
りポリアミド樹脂被膜を生成させることを特徴と
する直接窒化AlN粉体の表面被覆方法。1. When coating the surface of AlN powder produced by direct nitriding with a polyamide resin film,
After oxidizing the AlN powder, the oxidized
Coating the surface of AlN powder particles with a dibasic acid or a derivative thereof, dispersing the coated AlN powder in a solution of diamine or diamine derivative,
A method for directly coating the surface of nitrided AlN powder, which is characterized by generating a polyamide resin film by causing a polymerization reaction on the particle surface of AlN powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13975789A JPH035311A (en) | 1989-06-01 | 1989-06-01 | Method for coating surface of directly nitrided aln powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13975789A JPH035311A (en) | 1989-06-01 | 1989-06-01 | Method for coating surface of directly nitrided aln powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH035311A JPH035311A (en) | 1991-01-11 |
| JPH0571526B2 true JPH0571526B2 (en) | 1993-10-07 |
Family
ID=15252681
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13975789A Granted JPH035311A (en) | 1989-06-01 | 1989-06-01 | Method for coating surface of directly nitrided aln powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH035311A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4783674B2 (en) * | 2006-05-26 | 2011-09-28 | リンナイ株式会社 | Hot plate |
| JP5019003B2 (en) * | 2010-02-18 | 2012-09-05 | 日立化成工業株式会社 | COMPOSITE PARTICLE, PROCESS FOR PRODUCING THE SAME AND RESIN COMPOSITION |
| EP4253483A3 (en) * | 2018-08-24 | 2024-03-27 | Resonac Corporation | Silicon-containing oxide-coated aluminum nitride particles |
-
1989
- 1989-06-01 JP JP13975789A patent/JPH035311A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH035311A (en) | 1991-01-11 |
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