JP2004250482A - Epoxy resin composition and electrical device using the same - Google Patents
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【０００１】
【発明の属する技術分野】
本発明は、電気機器のモールド樹脂等に使用されるエポキシ樹脂組成物およびそれを用いた電気機器に関する。
【０００２】
【従来の技術】
従来の無機充填材を充填したエポキシ樹脂組成物は、その強度・弾性率・靭性・熱伝導率などの特性を高めたり、硬化発熱を放散させたりするため、液状または加熱溶融した未硬化エポキシ樹脂に、粒径が１〜２００μｍの粒子状、線状、箔状の無機充填材をそれぞれ単独または組み合わせて混合して成形・硬化させていた（例えば、特許文献１および特許文献２参照）。
【０００３】
【特許文献１】特開平１１−０９２６２７
【特許文献２】特開平０９−０７７９５７
【０００４】
【発明が解決しようとする課題】
しかしながら、従来のエポキシ樹脂組成物は、液状または加熱溶融した未硬化エポキシ樹脂に粒径が５μｍ以上の無機粒子を充填した場合は、粘度の上昇が小さいため高充填可能であるが、充填率に対して特性の向上が小さいという問題がある。一方、充填率に対して特性の向上が大きな無機充填材、つまり比表面積が大きいサブミクロン微粒子や箔状や線状の無機充填材を充填した場合、粘度上昇がきわめて大きく高充填ができないため、特性を向上させることができないという問題がある。
また、５μｍ以上の無機粒子を充填した場合、加熱硬化時の温度上昇で樹脂粘度が低下し、厚肉部では比重が高く比表面積が小さいな無機粒子が沈降していた。一方、比表面積が大きな無機充填材（微粒子や線状、箔状）を併用して沈降を防止すると、粘度が高くなり成形作業性が悪く、空隙が発生するなどの問題がある。
そこで、本発明はこのような問題点に鑑みてなされたものであり、無機充填材の充填による粘度上昇を抑制することで充填率を高め、高強度、高靭性・高熱伝導率のエポキシ樹脂組成物、およびそれを用いた電気機器を提供することと、成形時は粘度が低いが、加熱硬化時は粘度を上昇させることで、成形作業性は良好で無機粒子が沈降しないエポキシ樹脂組成物、およびそれを用いた電気機器を提供することを目的とする。
【０００５】
【課題を解決するための手段】
上記問題を解決するため、本発明は次のように構成したものである。
（１）無機充填材と固形エポキシ樹脂とからなり、粒子径が５μｍ〜１０ｍｍ、好ましくは１０μｍ〜２００μｍの合成粒子を、エポキシ樹脂に充填したエポキシ樹脂組成物である。
（２）前記固形エポキシ樹脂は、未硬化または半硬化の状態のものを、前記固形エポキシ樹脂の融解温度以下の温度にて金型やワーク等に注入し、前記固形エポキシ樹脂の融解温度以上の温度にて硬化させたエポキシ樹脂組成物である。
（３）前記無機充填材は、１ｎｍ以上、２μｍ以下の粒子径からなる微粒子状無機充填材、および／または、１μｍ以上の長さからなる線状またはそれを折り曲げた形状のもの、および／または、１０μｍ以下の厚さからなる箔状またはそれを折りたたんだ形状のものとしたエポキシ樹脂組成物である。
（４）前記無機充填材は、アルミナ、ホウ酸アルミニウム、シリカ、炭化ケイ素、窒化ケイ素、窒化アルミニウム、チタン酸カリウム、ホウ酸マグネシウム、カーボン、グラファイト、チラノ繊維、アラミド繊維、マイカ、モンモリロナイト、酸化チタン、ガラス、各種金属、各種熱可塑性プラスチック、各種ゴムまたはそれらの混合物の少なくとも１つからなるエポキシ樹脂組成物である。
以上の構成により、充填率に対する特性の向上が大きい。つまり比表面積が大きな無機充填材を液状エポキシ樹脂に充填する際に、固形エポキシ樹脂にて比表面積を小さくすることで、粘度上昇を抑えて無機充填材を高充填することができる。よって、これらの無機充填材を充填しても硬化物内の空隙率を低下させることができるとともに、硬化物の強度を大幅に高めることができる。
（５）前記無機充填材は形状記憶合金からなり、前記形状記憶合金の変態温度以上かつ前記固形エポキシ樹脂の融解温度以上の温度にて硬化したエポキシ樹脂組成物である。
（６）前記形状記憶合金は１００μｍ以上の長さからなる線状またはそれを折り曲げた形状、および／または前記形状記憶合金は１００μｍ以下の厚さからなる箔状またはそれを折りたたんだ形状のエポキシ樹脂組成物である。
（７）前記形状記憶合金は、ニッケル／チタン合金、ニッケル／チタン／銅合金、ニッケル／チタン／コバルト合金、ニッケル／チタン／鉄合金、またはそれらの混合物の少なくとも１つからなるエポキシ樹脂組成物である。
以上の構成により、充填率に対する熱伝導率の向上が大きい、つまり比表面積が大きな無機充填材を液状エポキシ樹脂に充填する際に、固形エポキシ樹脂にて比表面積を小さくすることができ、粘度上昇を抑えて無機充填材を高充填し、また、無機充填材が相互に接触するため、硬化物の熱伝導率を大幅に高めることができる。
（８）上記（１）から（４）に記載のエポキシ樹脂組成物に、無機粒子を充填してなるものであり、この無機粒子は、アルミナ、シリカ、炭化ケイ素、窒化ケイ素、窒化アルミニウム、チタン酸カリウム、ホウ酸マグネシウム、カーボン、モンモリロナイト、酸化チタン、ガラス、各種金属またはそれらの混合物の少なくとも１つからなるエポキシ樹脂組成物である。
以上の構成により、成形作業性が良く、厚肉部においても粒子の沈降を防止することができ均一に分散した良好な厚肉の硬化物を得ることができる。
（９）上記（１）から（８）に記載のエポキシ樹脂組成物をモールド材としてコイル、ブッシングまたは碍子など用いた電気機器である。
以上の構成により、高性能な電気機器を得ることができる。
【０００６】
【発明の実施の形態】
以下、本発明の実施の形態を図に基づいて説明する。
（第１の実施形態）
図１は、本発明の未硬化液状エポキシ樹脂と混合させる合成粒子の構造を示す断面の模式図である。図１において、１は合成粒子、２は無機充填材の一つである粒子径が２μｍ以下の微粒子状無機充填材、３は線状や箔状の無機充填材、４は固形エポキシ樹脂である。合成粒子１は、微粒子状無機充填材２と線状や箔状の無機充填材３および固形エポキシ樹脂４からなる。
合成粒子１の径は、粘度上昇が小さい５μｍ以上であり、電気機器のコイルモールド樹脂として用いるためには２００μｍ以下が好ましく、ブッシングなどの厚肉成形品を得る場合は１０ｍｍ程度の大きさとしても良い。
合成粒子１は、粒子径が５μｍ以上と粗大であり比表面積が小さいため、固形エポキシ樹脂４が硬化物のときや、未硬化または半硬化でも融解温度以下の温度に保持した液状エポキシ樹脂に充填したとき、つまり固形エポキシ樹脂４が融解していないときの粘度上昇は、従来の粗大な無機粒子を充填した場合と同様に低く、高充填可能となる。固形エポキシ樹脂４が未硬化や半硬化場合、このエポキシ樹脂組成物の成形時の温度は固形エポキシ樹脂４の融解温度以下とすることで低粘度のまま保ち、硬化温度は合成粒子の固形エポキシ樹脂４の融解温度以上として融解させ、合成粒子１周囲の液状エポキシ樹脂と均一化するとともに、無機充填材をエポキシ樹脂組成物内に分散させることができる。
合成粒子１の製造方法について述べる。
▲１▼ 固形エポキシ樹脂４が硬化物の場合は、固形エポキシ樹脂４の液状未硬化原料を、微粒子状無機充填材２や線状や箔状の無機充填材３を加え、ニーダにて強力なせん断を与えて混合し、加熱した平板上に薄く広げて真空脱泡し、加熱硬化後に粉砕・分級することで作製した。
▲２▼ 固形エポキシ樹脂４が未硬化または半硬化の場合は、固形エポキシ樹脂４を加熱溶融させ、微粒子状無機充填材２や線状や箔状の無機充填材３を加え、ニーダにて強力なせん断を与えて混合し、固形エポキシ樹脂４の融解温度以上に加熱した平板上に薄く広げて真空脱泡し、冷却固化後に粉砕・分級することで作製した。
次に、組成と粘度を表１に示す。本実施例のエポキシ樹脂組成物は、コイルモールド（に向けた粒度分布である）を想定し、合成粒子１の粒度分布を５〜２００μｍ、中心粒径を３０μｍとした。比較例として、従来のエポキシ樹脂組成物の組成も加えた。
エポキシ樹脂組成物に用いた材料は以下のとおりである。
（イ）無機充填材： 微粒子状無機充填材２としてアルミナ（破砕形状、中心粒径１μｍ）を、線状や箔状の無機充填材３としてガラス繊維（直径１０μｍ、長さ５０μｍ）およびマイカフレーク（厚さ１μｍ、中心粒径５０μｍ）を用いた。
（ロ）固形エポキシ樹脂：ビスフェノールＡ型（エポキシ当量４５０、融解温度７０℃）
（ハ）液状エポキシ樹脂：ビスフェノールＡ型（エポキシ当量１９０）
（ニ）硬化剤：３フッ化ホウ素モノエチルアミン
表１より、実施例１は、微粒子状アルミナを固形エポキシ樹脂にて合成粒子１として充填したものであるが、同じアルミナをそのまま充填した比較例１の２倍の量を高充填しても粘度は変わらなかった。実施例２は、ガラス繊維を固形エポキシ樹脂にて合成粒子１として充填したものであるが、同じガラス繊維をそのまま充填した比較例２の３倍高充填しても粘度は低かった。実施例３はマイカフレークを固形エポキシ樹脂にて合成粒子１として充填したものであるが、同じマイカをそのまま充填した比較例３の３倍高充填しても粘度は低かった。また、実施例４はこれら３種類の無機充填材を混合して固形エポキシ樹脂にて合成粒子１として充填したものであるが、粘度上昇が特に大きなガラス繊維やマイカをそのまま充填した比較例２，３よりも粘度は低かった。
以上の結果より、本発明により粘度上昇の大きな無機充填材を、粘度上昇を抑えて充填することが可能となり、つまり、粘度上昇の大きな無機充填材を高充填可能にすることができた。
【０００７】
【表１】
（第２の実施形態）
本実施形態は、補強効果の高い高アスペクト比の無機充填材、つまり比表面積の大きな無機充填材を、粘度上昇を抑えることで高充填可能にしたものである。
第１の実施形態と異なる点は、無機充填材の一部だけであり、他の条件は第１の実施形態と同じである。
無機充填材：線状や箔状の無機充填材３としてガラス繊維に代えてホウ酸アルミニウムウイスカ（直径０．５μｍ、長さ２０μｍ）を用いた。
表２より、ホウ酸アルミニウムウイスカを固形エポキシ樹脂にて合成粒子として充填した実施例５は、同じホウ酸アルミニウムをそのまま充填した比較例１の３倍高充填しても粘度は低く、曲げ強度は約２倍高かった。マイカフレークを固形エポキシ樹脂にて合成粒子として充填した実施例６は、同じマイカをそのまま充填した比較例５の３倍高充填しても粘度は低く、曲げ強度は約２倍高かった。また、実施例５，６の固形エポキシ樹脂の一部をアルミナ微粒子にて置き換えた実施例７，８は、実施例５，６よりも粘度は若干上昇したが曲げ強度は約３０％高くなった。また、これら３種類の無機充填材を混合して固形エポキシ樹脂４にて合成粒子として充填した実施例９は、ホウ酸アルミニウムやマイカをそのまま充填した比較例４，５よりも粘度は低く、曲げ強度は３倍以上高かった。
以上の結果より、本発明により粘度上昇の大きな無機充填材を、粘度上昇を抑えて高充填することが可能となり、エポキシ樹脂組成物の強度を高めることができた。
【０００９】
【表２】
（第３の実施形態）
次に、本発明のエポキシ樹脂組成物を電気機器のコイルモールドとして使用した例について説明する。本試料の形状を図２に示す。図２は、注形されたコイルを示す図で、（ａ）は平面図、（ｂ）は側断面図である。図において、５はボビン、 ６はコイル、７はエポキシ樹脂組成物である。
本試料は、直径３０ｍｍ、厚さ５ｍｍのフェノール樹脂製のボビン５に、φ１ｍｍの１種ポリエステルエナメル線を外径４０ｍｍとなるよう２線を平行に整列巻きしたコイル６を、幅４５ｍｍ、高さ４５ｍｍ、厚さ７ｍｍの内容積を持つ図示しない金型に取り付け、表３に示すエポキシ樹脂組成物７にて真空成形し、１５０℃、８ｈｒにて硬化後に離型したものである。エポキシ樹脂組成物の材料構成は、表１に示した実施例１〜４、比較例１〜３と同じものとした。
外観やコイル部分の断面を観察し、モールド樹脂部分やコイル素線間の気泡や未充填部の有無と、モールド樹脂部分の空隙率と、交流６０Ｈｚでの部分放電開始電圧にて評価した。
表３に評価結果を示す。観察の結果、本発明の実施例１０〜１３のエポキシ樹脂組成物にて注形したコイルのモールドには、気泡や未充填部が見られず、部分放電開始電圧が高かったのに対し、比表面積の大きな無機充填材をそのまま充填した比較例６〜８は気泡や未充填部が見られ、空隙率が１％以上有り、部分放電開始電圧も低かったことから、本発明の有効性が確認された。
【００１１】
【表３】
（第４の実施形態）
次に、第３の実施形態と同じく、本発明のエポキシ樹脂組成物を電気機器のコイルモールドとして使用し、クラック発生について評価した例について説明する。
本試料の形状は第３の実施形態と同じである。本試料は、直径３０ｍｍのケイ素鋼板の薄板を５ｍｍ厚さに積層したボビン４に、φ１ｍｍの１種ポリエステルエナメル線を外径４０ｍｍとなるよう整列巻きしたコイル６を、幅４５ｍｍ、高さ４５ｍｍ、厚さ７ｍｍの内容積を持つ図示しない金型に取り付け、表４に示すエポキシ樹脂組成物７にて真空成形し、１５０℃、８ｈｒにて硬化後に離型したものである。エポキシ樹脂組成物の材料構成は、表２に示した実施例５〜９、比較例４、５と同じものとした。
外観を観察し、モールド樹脂のクラックの有無にて評価した。
表４に評価結果を示す。観察の結果、本発明の実施例１４〜１８のエポキシ樹脂組成物にて注形したコイルのモールドにはクラックが見られなかったのに対し、比表面積の大きな無機充填材をそのまま充填した比較例９，１０はクラックが発生したことから、本発明の有効性が確認された。
【００１３】
【表４】
（第５の実施形態）
次に、本発明のエポキシ樹脂組成物を電気機器のブッシングなどの厚肉注形品に適用した例について説明する。
合成粒子１は、粒度分布を１〜１０ｍｍ、中心粒子径を３ｍｍとした。本実施例のエポキシ樹脂組成物と、従来のエポキシ樹脂組成物の組成と粘度を表５に示す。エポキシ樹脂組成物の材料構成は、表１に示した実施例１〜４、比較例１〜３と同じものとし、粒度分布を１〜１０ｍｍ、中心粒子径を３ｍｍとした。
表５より、微粒子状アルミナを固形エポキシ樹脂にて合成粒子１として充填した実施例１９は、同じアルミナをそのまま充填した比較例１１の２倍高充填しても粘度は低かった。ガラス繊維を固形エポキシ樹脂にて合成粒子１として充填した実施例２０は、同じガラス繊維をそのまま充填した比較例１２の３倍高充填しても粘度は低かった。マイカフレークを固形エポキシ樹脂にて合成粒子１として充填した実施例２１は、同じマイカをそのまま充填した比較例１３の３倍高充填しても粘度は低かった。また、これら３種類の無機充填材を混合して固形エポキシ樹脂にて合成粒子１として充填した実施例２２は、粘度上昇が特に大きなガラス繊維やマイカをそのまま充填した比較例１２、１３よりも粘度は低かった 。
以上の結果より、本発明は厚肉注形品に向けても、粘度上昇の大きな無機充填材を、粘度上昇を抑えて充填することが可能となり、つまり、粘度上昇の大きな無機充填材を高充填可能にすることができた。
【００１５】
【表５】
（第６の実施形態）
次に、本発明のエポキシ樹脂組成物を電気機器のブッシングなどの厚肉注形品を対象にして、エポキシ樹脂組成物の強度で評価した例について説明する。
合成粒子１は、第５の実施形態と同じく粒度分布を１〜１０ｍｍ、中心粒径を３ｍｍとした。
本実施例のエポキシ樹脂組成物と、従来のエポキシ樹脂組成物の組成と粘度と曲げ強度を表６に示す。エポキシ樹脂組成物の材料構成は、表２に示した実施例５〜９、比較例４、５と同じものとし、粒度分布を１〜１０ｍｍ、中心粒子径を３ｍｍとしたものである。
表６より、ホウ酸アルミニウムウイスカを固形エポキシ樹脂にて合成粒子として充填した実施例２３は、同じホウ酸アルミニウムウイスカをそのまま充填した比較例１４の３倍高充填しても粘度は低く、曲げ強度は高かった。マイカフレークを固形エポキシ樹脂にて合成粒子として充填した実施例２４は、同じマイカフレークをそのまま充填した比較例１５の３倍高充填しても粘度は低く、曲げ強度は高かった。実施例２３の固形エポキシ樹脂の一部をアルミナ微粒子にて置き換えた実施例２５は、同じホウ酸アルミニウムウイスカをそのまま充填した比較例１４の３倍高充填しても粘度は低く、曲げ強度は高かった。実施例２４の固形エポキシ樹脂の一部をアルミナ微粒子にて置き換えた実施例２６は、同じマイカフレークをそのまま充填した比較例１５の３倍高充填しても粘度は低く、曲げ強度は高かった。また、これら３種類の無機充填材を混合して固形エポキシ樹脂にて合成粒子として充填した実施例２７は、粘度上昇が特に大きなガラス繊維やマイカをそのまま充填した比較例１４、１５よりも粘度は低く、曲げ強度は高かった。
以上の結果より、本発明により、厚肉注形品に向けた粒度分布においても、粘度上昇の大きな無機充填材を、粘度上昇を抑えて充填することが可能となり、つまり、粘度上昇の大きな無機充填材を高充填可能にすることができた。
【００１７】
【表６】
（第７の実施形態）
次に、本発明のエポキシ樹脂組成物を電気機器の厚肉部品であるブッシングのモールドとして使用し、気泡や空隙の発生について評価した例について説明する。
本試料の形状を図３に示す。図３は、注形された模擬ブッシングを示す図で、（ａ）は平面図、（ｂ）は側断面図である。ブッシングを模擬して、直径４０ｍｍ、長さ６０ｍｍの円柱に２箇所のくびれ部分を設けた。本試料は、直径１０ｍｍの鉄棒８を図示しない金型に取り付け、表７に示すエポキシ樹脂組成物７にて真空成形し、１５０℃、８ｈｒにて硬化後に離型したものである。エポキシ樹脂組成物の材料構成は、表５に示した実施例１９〜２２、比較例１１〜１３と同じものとした。
表７に評価結果を示す。外観や断面を観察し、モールド樹脂部分の気泡や未充填部の有無とモールド樹脂部分の空隙率にて評価した。
観察の結果、本発明の実施例２８〜３１のエポキシ樹脂組成物にて注形したコイルのモールドには、気泡や未充填部が見られなかったのに対し、比表面積の大きな無機充填材をそのまま充填した比較例１６〜１８は気泡や未充填部が見られ、空隙率が１％以上有ったことから、本発明の有効性が確認された。
【００１９】
【表７】
（第８の実施形態）
次に、本発明のエポキシ樹脂組成物を電気機器の厚肉部品であるブッシングのモールドとして使用し、クラックの有無にて評価した例について説明する。
本試料の条件は、無機充填材など組成物の条件が異なる以外は、第７の実施形態と同じである。
なお、エポキシ樹脂組成物の材料構成は、表６に示した実施例２３〜２７、比較例１４，１５と同じものとした。
外観や断面を観察し、モールド樹脂部分のクラックの有無にて評価した。
表８に評価結果を示す。観察の結果、本発明の実施例３２〜３６のエポキシ樹脂組成物にて注形したコイルのモールドにはクラックが見られなかったのに対し、比表面積の大きな無機充填材をそのまま充填した比較例１９，２０はクラックが見られたことから、本発明の有効性が確認された。
【００２１】
【表８】
（第９の実施形態）
本実施形態は、熱伝導率が高く、高アスペクト比の無機充填材、つまり熱伝導率を向上させる効果が高い無機充填材を、粘度上昇を抑えることで高充填可能にしたものである。
第１の実施形態と異なる点は無機充填材の一部に形状記憶合金を用いたことと微粒子状無機充填材の粒径だけであり、他の材料は第１の実施形態と同じである。
形状記憶合金：ニッケル／チタン合金（直径０．１５ｍｍ、平均長さ２ｍｍ、変態温度５０〜７０℃）、ニッケル／チタン／銅合金（直径０．２ｍｍ、平均長さ２ｍｍ、変態温度５０〜８０℃）、ニッケル／チタン／鉄合金（直径０．１５ｍｍ、平均長さ２ｍｍ、変態温度５０〜７０℃）
粒子状無機充填材：アルミナ（中心粒径１μｍ）、アルミナ（中心粒径１５μｍ）
このエポキシ樹脂組成物の成形時の温度は固形エポキシ樹脂４の融解温度以下とすることで低粘度のまま保ち、硬化温度は固形エポキシ樹脂４の融解温度以上として固形エポキシ樹脂４を融解させ、合成粒子１周囲の液状エポキシ樹脂と均一化するとともに、形状記憶合金３や微粒子状無機充填材２をエポキシ樹脂組成物７内に分散することができる。さらに、硬化温度を形状記憶合金３の変態温度以上とすることで、折り曲げられた形状記憶合金３の形状を復元させて、近傍の形状記憶合金３と接触させることができる。
合成粒子１と液状エポキシ樹脂の混合は、形状記憶合金３の変態温度や固形エポキシ樹脂４の融解温度よりも低い２０℃で行い、エポキシ樹脂組成物の加熱硬化温度は形状記憶合金３の変態温度や固形エポキシ樹脂の融解温度よりも高い１５０℃とした。硬化時間は８ｈｒとした。
次に、合成粒子１の粒度分布を１〜２ｍｍ、中心粒径を１．５ｍｍとした本発明のエポキシ樹脂組成物について、組成と粘度と熱伝導率との関係を表９に示す。また、本発明の比較例として、形状記憶合金単独で充填した場合と、従来の高熱伝導セラッミック粒子を充填したエポキシ樹脂組成物について、組成と粘度と熱伝導率との関係を表９に示す。
表９より、ニッケル／チタン合金と固形エポキシ樹脂との合成粒子を充填した実施例３７は、同じニッケル／チタン合金をそのまま充填した比較例２１の３倍高充填しても粘度は低く、熱伝導率は比較例２１よりも１桁高く、アルミナ粒子を高充填した比較例２４よりも高かった。ニッケル／チタン／銅合金と固形エポキシ樹脂との合成粒子を充填した実施例３８は、同じニッケル／チタン／銅合金をそのまま充填した比較例２２の３倍高充填しても粘度は低く、熱伝導率は比較例２２よりも１桁高く、アルミナ粒子を高充填した比較例２４よりも高かった。
ニッケル／チタン／鉄合金と固形エポキシ樹脂との合成粒子を充填した実施例３９は、同じニッケル／チタン／鉄合金をそのまま充填した比較例２３の３倍高充填しても粘度は低く、熱伝導率は比較例２３よりも１桁高く、アルミナ粒子を高充填した比較例２４よりも高かった。また、これら３種類の無機充填材を混合して固形エポキシ樹脂４にて合成粒子として充填した実施例４０は、実施例２１，２２，２３と同等の粘度と熱伝導率が得られた。実施例４０の固形エポキシ樹脂の一部をアルミナ微粒子にて置き換えた実施例４１は、実施例３７，３８，３９，４０よりも粘度は若干上昇したが、熱伝導率は高くなった。以上の結果より、本発明により粘度上昇の大きな線状の形状記憶合金無機充填材を、粘度上昇を抑えて高充填することが可能となり、エポキシ樹脂組成物の熱伝導率を高めることができた。
【００２３】
【表９】
（第１０の実施形態）
次に、箔状の形状記憶合金３を充填した合成粒子１を用いた例について説明する。箔状の形状記憶合金の製造方法について述べる。第９の実施形態にて用いた３種類の線状の形状記憶合金を、約０．３ｍｍの長さに切断し、５００℃の加熱下でヒートプレスして厚さ１００μｍ以下の箔状の形状を記憶させた。
合成粒子１の製造方法ならびに、液状エポキシ樹脂との混合、硬化方法は第１の実施形態と同じである。
次に、合成粒子１の粒度分布を１〜２ｍｍ、中心粒径を１．５ｍｍとした本発明のエポキシ樹脂組成物について、組成と粘度と熱伝導率との関係を表１０に示す。材料の組成は表９の実施例と同じであり、形状記憶合金無機充填材３の形状のみが異なる。また、本発明の比較例は、第９の実施形態と同じであり表９に示す。
表１０より、ニッケル／チタン合金と固形エポキシ樹脂との合成粒子を充填した実施例４２は、同じニッケル／チタン合金をそのまま充填した比較例２１の３倍高充填しても粘度は低く、熱伝導率は比較例２１よりも１桁高く、アルミナ粒子を高充填した比較例２４よりも高かった。ニッケル／チタン／銅合金と固形エポキシ樹脂との合成粒子を充填した実施例４３は、同じニッケル／チタン／銅合金をそのまま充填した比較例２２の３倍高充填しても粘度は低く、熱伝導率は比較例２２よりも１桁高く、アルミナ粒子を高充填した比較例２４よりも高かった。ニッケル／チタン／鉄合金と固形エポキシ樹脂との合成粒子を充填した実施例４４は、同じニッケル／チタン／鉄合金をそのまま充填した比較例２３の３倍高充填しても粘度は低く、熱伝導率は比較例２３よりも１桁高く、アルミナ粒子を高充填した比較例２４よりも高かった。また、これら３種類の無機充填材を混合して固形エポキシ樹脂４にて合成粒子として充填した実施例４５は、実施例４２，４３，４４と同等の粘度と熱伝導率が得られた。実施例４５の固形エポキシ樹脂の一部をアルミナ微粒子にて置き換えた実施例４６は、実施例３７，３８，３９，４０よりも粘度は若干上昇したが、熱伝導率は高くなった。以上の結果より、本発明により粘度上昇の大きな箔状無機充填材を、粘度上昇を抑えて高充填することが可能となり、エポキシ樹脂組成物の熱伝導率を高めることができた。
【００２５】
【表１０】
（第１１の実施形態）
次に、本発明のエポキシ樹脂組成物を電気機器のコイルモールドとして使用した例について説明する。本試料の形状を図４に示す。図４は、注形されたコイルを示す図で、（ａ）は平面図、（ｂ）は側断面図である。本試料は、直径３８ｍｍ、のケイ素鋼板の薄板を５ｍｍ厚さに積層したボビン５に熱電対９を取り付け、φ２ｍｍの絶縁処理したニクロム線を外径４０ｍｍとなるよう整列巻きしたコイル６を、幅４５ｍｍ、高さ４５ｍｍ、厚さ１５ｍｍの内容積を持つ図示しない金型に取り付け、表９に示すエポキシ樹脂組成物７にて真空成形し、１５０℃、８ｈｒにて硬化後に離型したものである。エポキシ樹脂組成物７の材料構成は、表９に示した実施例３７から４１、比較例２１から２４と同じものとした。
評価は、２５℃の水中にて、コイル６に図示しない抵抗と交流電源を接続し、１００Ｖ、６０Ｈｚの交流電圧を印加して温度上昇の経時変化を測定することで行った。表１１に評価結果を示す。温度変化が飽和した時の温度ライズにて評価した。本発明の実施例３７から４１のエポキシ樹脂組成物にて注形したコイルは温度ライズが数度であったのに対し、比較例のエポキシ樹脂組成物にて注形したコイルの温度ライズは１０℃以上あったことから、本発明の有効性が確認された。
【００２７】
【表１１】
ちなみに形状記憶合金は、樹脂温度を低温に管理した場合はニッケル／チタン／コバルト合金（変態温度０〜−８０℃）でも良い。また、本実施例での合成粒子の直径は１ｍｍ以上としたが、形状記憶合金のウイスカや鱗片等を用いれば、合成粒子の直径は１００μｍ程度の粒子径でも良く、また厚肉注形品の場合は数ｍｍ〜１０ｍｍとしても良いことは言うまでも無い。
【００２９】
（第１２の実施形態）
本実施形態は、厚肉部分をモールドする樹脂に比重の大きな無機粒子を充填する際に、成形時は粘度上昇を抑えて作業性を良好にし、加熱硬化時は、樹脂に比表面積が大きい無機充填材、つまり粘度を上昇させる効果が高い無機充填材を分散させて増粘させ、無機粒子の沈降を防止したものである。
第１の実施形態と異なる点は無機充填材の一部だけであり、他の材料は第１の実施形態と同じである。
合成粒子１の径は粘度上昇が小さい５μｍ以上であり、電気機器のモールド樹脂として用いるためには２００μｍ以下が良い。
合成粒子中の比表面積が大きな無機充填材：シリカ（アエロジール、粒径０．００７μｍ）、アルミナ（研磨用、平均粒径０．０５μｍ）の微粒子
液状エポキシ樹脂に充填する無機粒子：アルミナ（球状、平均粒径４０μｍ、比重３．９）、溶融シリカ（球状、平均粒径１５μｍ、比重２．７）
図５は、合成粒子１を充填したエポキシ樹脂組成物を室温より加熱したときの温度と粘度の関係を示す特性図である。合成粒子１は粒子径が５μｍ以上と粗大であり比表面積が小さいため、固形エポキシ樹脂４の融解温度以下の液状エポキシ樹脂に充填したとき、つまり固形エポキシ樹脂４が融解していないときの粘度上昇は、従来の無機粒子を充填した場合と同様に低く、成形作業性を損なうことは無い。このエポキシ樹脂組成物の成形時の温度は固形エポキシ樹脂４の融解温度以下とすることで低粘度のまま保つ。硬化温度は合成粒子１の固形エポキシ樹脂４の融解温度以上として融解させ、合成粒子周囲の液状エポキシ樹脂と均一化するとともに、比表面積が大きい微粒子や箔状、線状の無機充填材をエポキシ樹脂組成物内に分散させ、粘度を高めることができる。
合成粒子１の製造方法は第１の実施形態と同様である。
次に、組成と粘度と無機物沈降の評価結果を表１２に示す。粘度は成形温度である４０℃と硬化温度である１００℃を測定した。また評価は、１０ｍｍの辺を持つ立方体を作製する図示しない金型に成形・硬化させた硬化物を、成形時の置き方で上下２分割に切り出し、５００℃、１ｈｒでの灼熱残渣を秤量して、硬化物中の無機物含有率を測定した。
本実施例のエポキシ樹脂組成物は、コイルモールドに向けた粒度分布を想定し、合成粒子１の粒度分布を５〜１００μｍ、中心粒径を３０μｍとした。比較例として、従来のエポキシ樹脂組成物の組成も加えた。
表１２より、本発明の実施例４２〜４４のエポキシ樹脂組成物は、成形温度である４０℃での粘度は低いが硬化温度である１００℃での粘度は４０℃よりも高くなり、また、硬化物の部位による無機物含有率がほとんど変わらなかった。これに対し、無機粒子をそのまま充填した比較例２５，２６は、１００℃での粘度は４０℃よりもきわめて低くなり、硬化物は無機粒子の沈降が顕著に見られたことから、本発明の有効性が確認された。
【００３０】
【表１２】
（第１３の実施形態）
本実施形態は、高アスペクト比の無機充填材を合成粒子に充填したものである。
第１２の実施形態と異なる点は粒子の一部だけであり、他の条件は第１２の実施形態と同じである。
合成粒子１中の比表面積が大きな線状や箔状の無機充填材３として、微粒子状無機充填材２に代えてホウ酸アルミニウムウイスカ（直径０．５〜１μｍ、長さ１０〜３０μｍ）、合成マイカフレーク（平均径１〜５μｍ、アスペクト比２０〜３０）を用いた。
組成と粘度と無機物沈降の評価結果を表１３に示す。表１３より、本発明の実施例４５〜４７のエポキシ樹脂組成物は、成形温度である４０℃での粘度は低いが硬化温度である１００℃での粘度は４０℃よりも高くなり、硬化物の部位による無機物含有率がほとんど変わらなかった。これに対し、表１２に示した無機粒子をそのまま充填した比較例２５，２６の硬化物は、１００℃での粘度は４０℃よりもきわめて低くなり、硬化物は無機粒子の沈降が顕著に見られたことから、本発明の有効性が確認された。
【００３２】
【表１３】
（第１４の実施形態）
次に、本発明のエポキシ樹脂組成物を電気機器の厚肉部品であるブッシングのモールドとして使用した例について説明する。
本試料の形状を図３に示す。本試料は、直径１０ｍｍの鉄棒８を図示しない金型に取り付け、表１４に示すエポキシ樹脂組成物７にて真空成形し、１５０℃、８ｈｒにて硬化後に離型したものである。エポキシ樹脂組成物の材料構成は表１２，１３に示した実施例４３，４３，４５，４６、比較例２５，２６と同じものとした。
表１４に評価結果を示す。成形・硬化させた模擬ブッシングのエポキシ樹脂組成物７を、成形時の置き方で上から１０ｍｍ厚の部分と下から１０ｍｍ厚の部分を切り出し、５００℃、１ｈｒでの灼熱残渣を秤量して硬化物中の無機物含有率を測定した。表３より、本発明の実施例４３〜４６のエポキシ樹脂組成物にて成形したブッシングのモールドは、部位による無機物含有率がほとんど変わらなかったのに対し、粒子をそのまま充填した比較例２７，２８は無機粒子の沈降が顕著に見られたことから、本発明の有効性が確認された。
【００３４】
【表１４】
ちなみに、無機充填材と固形エポキシ樹脂からなる粒子の製造は、未硬化または半硬化の固形エポキシ樹脂を有機溶剤等で溶解させ無機充填材と混合した後、溶剤等を除去して固形化させ粉砕したり、スプレードライや超臨界二酸化炭素中での混合にて造粒しても良い。また、その無機充填材はアルミナやガラス繊維やマイカに限らず、粒子状ではアルミナ、シリカ、炭化ケイ素、窒化ケイ素、窒化アルミニウム、ホウ酸マグネシウム、アルミナ、カーボン、グラファイト、ガラス、各種金属、各種熱可塑性プラスチック、各種ゴムでも良く、線状ではホウ酸アルミニウム、炭化ケイ素、窒化ケイ素、チタン酸カリウム、ホウ酸マグネシウム、アルミナ、カーボン、グラファイト、チラノ繊維、アラミド繊維などの繊維やウイスカ、箔状ではモンモリロナイト、酸化チタン、窒化アルミニウム、金属箔などでも良い。
【００３６】
【発明の効果】
以上述べたように、本発明によればつぎの効果がある。
（１）本発明のエポキシ樹脂組成物は、無機充填材と固形エポキシ樹脂とからなり、粒子径が５μｍ〜１０ｍｍ、好ましくは１０μｍ〜２００μｍの合成粒子を、エポキシ樹脂に充填したもので、硬化温度は、固形エポキシ樹脂の融解温度以上の温度にて硬化させたものである。
（２）また、無機充填材は、２μｍ以下の粒子径からなる微粒子、または、粒子からなるもので、無機充填材は、１μｍ以上の長さからなる線状または１０μｍ以下の厚さからなる箔状をしたものである。
したがって、粘度上昇を抑えて無機充填材を高充填でき、空隙率が低く、高強度、高靭性・高熱伝導率のエポキシ樹脂組成物が得られる。
さらに
（３）無機充填材を形状記憶合金とし、固形エポキシ樹脂は未硬化または半硬化の状態のものを、形状記憶合金の変態温度以上かつ固形エポキシ樹脂の融解温度以上の温度にて硬化させたものである。
（４）また、形状記憶合金は１００μｍ以上の長さからなる線状またはそれを折り曲げた形状、および／または、１００μｍ以下の厚さからなる箔状またはそれを折りたたんだ形状としたものとからなるものである。
したがって、充填率に対する熱伝導率の向上が大きい無機充填材を、粘度上昇を抑えて無機充填材を高充填することができ、また、無機充填材が相互に接触するため、高熱伝導率のエポキシ樹脂組成物を得ることができる。
（５）合成粒子と無機粒子とをエポキシ樹脂に充填し、固形エポキシ樹脂は未硬化または半硬化の状態のものを、固形エポキシ樹脂の融解温度以上の温度にて硬化させたものである。
以上の構成により、成形作業性が良く、厚肉部においても無機粒子の沈降を小さくすることができ、無機充填材の沈降が無く均一に分散した良好な厚肉の硬化物を得ることができる。
（６）また、本発明のエポキシ樹脂組成物をモールド材に用いたコイルまたはブッシングまたは碍子などの電気機器モールド材として電気機器に用いたものである。
以上の構成により、このエポキシ樹脂組成物を用いた高性能な電気機器を得ることができる。
【図面の簡単な説明】
【図１】本発明のエポキシ樹脂組成物に混合する粒子の断面を示す模式図である。
【図２】本発明のエポキシ樹脂組成物にて注形されたコイルを示す図で、（ａ）は平面図、（ｂ）は側断面図である。
【図３】本発明のエポキシ樹脂組成物にて注形された模擬ブッシングを示す図で、（ａ）は平面図、（ｂ）は側断面図である。
【図４】本発明のエポキシ樹脂組成物にて注形されたコイルを示す図で、（ａ）は平面図、（ｂ）は側断面図である。
【図５】本発明のエポキシ樹脂組成物の温度と粘度との関係を示す特性図である。
【符号の説明】
１ 合成粒子
２ 微粒子状の無機充填材
３ 線状や箔状の無機充填材
４ 固形エポキシ樹脂
５ ボビン
６ コイル
７ エポキシ樹脂組成物
８ 鉄棒
９ 熱電対[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an epoxy resin composition used for a mold resin or the like of an electric device and an electric device using the same.
[0002]
[Prior art]
Epoxy resin compositions filled with conventional inorganic fillers are liquid or heat-melted uncured epoxy resins to enhance their properties such as strength, elasticity, toughness, and thermal conductivity, and to dissipate heat generated by curing. In addition, a particulate, linear, or foil-like inorganic filler having a particle size of 1 to 200 μm is used alone or in combination and molded and cured (for example, see Patent Documents 1 and 2).
[0003]
[Patent Document 1] JP-A-11-092627
[Patent Document 2] JP-A-09-077957
[0004]
[Problems to be solved by the invention]
However, when the conventional epoxy resin composition is filled with inorganic particles having a particle size of 5 μm or more in a liquid or heat-melted uncured epoxy resin, the increase in viscosity is small due to a small increase in viscosity. On the other hand, there is a problem that the improvement in characteristics is small. On the other hand, when an inorganic filler having a large improvement in characteristics with respect to the filling rate, that is, a submicron fine particle having a large specific surface area or a foil-like or linear inorganic filler is filled, the viscosity rise is extremely large and high filling cannot be performed. There is a problem that the characteristics cannot be improved.
In addition, when inorganic particles having a particle size of 5 μm or more were filled, the viscosity of the resin decreased due to an increase in temperature during heat curing, and inorganic particles having a high specific gravity and a small specific surface area were settled in a thick portion. On the other hand, if sedimentation is prevented by using an inorganic filler (fine particles, linear shape, foil shape) having a large specific surface area in combination, there are problems such as an increase in viscosity, poor molding workability, and generation of voids.
Accordingly, the present invention has been made in view of such problems, and an epoxy resin composition having a high strength, a high toughness, and a high thermal conductivity is suppressed by suppressing an increase in viscosity due to the filling of an inorganic filler. An epoxy resin composition, which provides a product, and an electric device using the same, and has a low viscosity at the time of molding, but increases the viscosity at the time of heat curing, whereby the molding workability is good and the inorganic particles do not settle, And an electric device using the same.
[0005]
[Means for Solving the Problems]
In order to solve the above problem, the present invention is configured as follows.
(1) An epoxy resin composition in which synthetic particles comprising an inorganic filler and a solid epoxy resin and having a particle diameter of 5 μm to 10 mm, preferably 10 μm to 200 μm are filled in the epoxy resin.
(2) The solid epoxy resin, in an uncured or semi-cured state, is injected into a mold or a work at a temperature equal to or lower than the melting temperature of the solid epoxy resin, and is injected at a temperature equal to or higher than the melting temperature of the solid epoxy resin. It is an epoxy resin composition cured at a temperature.
(3) The inorganic filler is a particulate inorganic filler having a particle size of 1 nm or more and 2 μm or less, and / or a linear or bent shape having a length of 1 μm or more, and / or And an epoxy resin composition having a foil shape or a folded shape having a thickness of 10 μm or less.
(4) The inorganic filler is alumina, aluminum borate, silica, silicon carbide, silicon nitride, aluminum nitride, potassium titanate, magnesium borate, carbon, graphite, tyranno fiber, aramid fiber, mica, montmorillonite, titanium oxide , Glass, various metals, various thermoplastics, various rubbers, or a mixture thereof.
According to the above configuration, the improvement in characteristics with respect to the filling rate is large. In other words, when filling the liquid epoxy resin with the inorganic filler having a large specific surface area, the specific surface area is reduced with the solid epoxy resin, whereby the increase in the viscosity can be suppressed and the inorganic filler can be highly filled. Therefore, even if these inorganic fillers are filled, the porosity in the cured product can be reduced, and the strength of the cured product can be significantly increased.
(5) The inorganic filler is a shape memory alloy, and is an epoxy resin composition cured at a temperature not lower than the transformation temperature of the shape memory alloy and not lower than the melting temperature of the solid epoxy resin.
(6) The shape memory alloy is a linear or bent shape having a length of 100 μm or more, and / or the shape memory alloy is a foil or a folded shape having a thickness of 100 μm or less. A composition.
(7) The shape memory alloy is an epoxy resin composition comprising at least one of a nickel / titanium alloy, a nickel / titanium / copper alloy, a nickel / titanium / cobalt alloy, a nickel / titanium / iron alloy, or a mixture thereof. is there.
With the above configuration, the improvement of the thermal conductivity with respect to the filling rate is large, that is, when filling the liquid epoxy resin with the inorganic filler having a large specific surface area, the specific surface area can be reduced with the solid epoxy resin, and the viscosity increases. And the inorganic filler is highly filled, and the inorganic filler contacts each other, so that the thermal conductivity of the cured product can be significantly increased.
(8) The epoxy resin composition according to any one of (1) to (4) above, which is filled with inorganic particles, and the inorganic particles include alumina, silica, silicon carbide, silicon nitride, silicon nitride, aluminum nitride, and titanium. An epoxy resin composition comprising at least one of potassium acid, magnesium borate, carbon, montmorillonite, titanium oxide, glass, various metals, or a mixture thereof.
According to the above configuration, the molding workability is good, the sedimentation of the particles can be prevented even in the thick portion, and a good thick cured product uniformly dispersed can be obtained.
(9) An electric device using the epoxy resin composition according to (1) to (8) as a molding material, such as a coil, a bushing, or an insulator.
With the above configuration, a high-performance electric device can be obtained.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(1st Embodiment)
FIG. 1 is a schematic sectional view showing the structure of a synthetic particle to be mixed with the uncured liquid epoxy resin of the present invention. In FIG. 1, 1 is a synthetic particle, 2 is one of inorganic fillers, a particulate inorganic filler having a particle diameter of 2 μm or less, 3 is a linear or foil-like inorganic filler, and 4 is a solid epoxy resin. . The synthetic particles 1 are composed of a particulate inorganic filler 2, a linear or foil-shaped inorganic filler 3 and a solid epoxy resin 4.
The diameter of the synthetic particles 1 is 5 μm or more, where the increase in viscosity is small, and is preferably 200 μm or less for use as a coil mold resin for electrical equipment. Even when a thick molded product such as a bushing is obtained, it may be about 10 mm. good.
Since the synthetic particles 1 have a coarse particle size of 5 μm or more and a small specific surface area, the solid epoxy resin 4 is filled into a liquid epoxy resin which is kept at a temperature below the melting temperature when it is a cured product or even when it is uncured or semi-cured. When the solid epoxy resin 4 is melted, that is, when the solid epoxy resin 4 is not melted, the increase in viscosity is low as in the case where the conventional coarse inorganic particles are filled, and the filling can be performed at a high level. When the solid epoxy resin 4 is uncured or semi-cured, the temperature at the time of molding the epoxy resin composition is maintained at a low viscosity by setting the temperature at or below the melting temperature of the solid epoxy resin 4, and the curing temperature is maintained at the solid epoxy resin of the synthetic particles. It is possible to disperse the inorganic filler in the epoxy resin composition while melting it at a temperature equal to or higher than the melting temperature of No. 4 and homogenizing the liquid epoxy resin around the synthetic particles 1.
A method for producing the synthetic particles 1 will be described.
{Circle around (1)} When the solid epoxy resin 4 is a cured product, the liquid uncured raw material of the solid epoxy resin 4 is added to the fine inorganic filler 2 or the inorganic filler 3 in a linear or foil form, and a strong kneader is used. It was produced by mixing by applying a shear, spreading thinly on a heated flat plate, defoaming in vacuum, crushing and classifying after heat curing.
{Circle around (2)} When the solid epoxy resin 4 is uncured or semi-cured, the solid epoxy resin 4 is heated and melted, and the fine particle inorganic filler 2 and the linear or foil-like inorganic filler 3 are added. The mixture was mixed by applying a gentle shear, spread thinly on a flat plate heated above the melting temperature of the solid epoxy resin 4, vacuum degassed, cooled, solidified, and then ground and classified.
Next, the composition and the viscosity are shown in Table 1. In the epoxy resin composition of this example, the particle size distribution of the synthetic particles 1 was 5 to 200 μm and the central particle size was 30 μm, assuming a coil mold (having a particle size distribution toward). As a comparative example, the composition of a conventional epoxy resin composition was also added.
The materials used for the epoxy resin composition are as follows.
(A) Inorganic filler: Alumina (crushed shape, central particle size: 1 μm) as fine-particle inorganic filler 2, glass fiber (diameter: 10 μm, length: 50 μm) and mica flake as linear or foil-shaped inorganic filler 3 (Thickness: 1 μm, center particle size: 50 μm).
(B) Solid epoxy resin: bisphenol A type (epoxy equivalent 450, melting temperature 70 ° C)
(C) Liquid epoxy resin: bisphenol A type (epoxy equivalent 190)
(D) Curing agent: boron trifluoride monoethylamine
From Table 1, it can be seen that Example 1 was obtained by filling fine particulate alumina as a synthetic particle 1 with a solid epoxy resin. Did not change. In Example 2, the glass fiber was filled as a synthetic particle 1 with a solid epoxy resin, but the viscosity was low even if the glass fiber was filled three times higher than in Comparative Example 2 in which the same glass fiber was filled as it was. In Example 3, mica flakes were filled as solid particles 1 with a solid epoxy resin, but the viscosity was low even if the mica flakes were filled three times as high as Comparative Example 3 in which the same mica was filled as it was. In Example 4, these three types of inorganic fillers were mixed and filled as a synthetic particle 1 with a solid epoxy resin. Comparative Examples 2 and 3 where glass fibers or mica whose viscosity increase was particularly large were filled as they were. The viscosity was lower than 3.
From the above results, it was possible to fill the inorganic filler having a large increase in viscosity according to the present invention while suppressing the increase in viscosity. That is, it was possible to highly fill the inorganic filler having a large increase in viscosity.
[0007]
[Table 1]
(Second embodiment)
In the present embodiment, an inorganic filler having a high reinforcing effect and a high aspect ratio, that is, an inorganic filler having a large specific surface area can be highly filled by suppressing an increase in viscosity.
The difference from the first embodiment is only a part of the inorganic filler, and other conditions are the same as those of the first embodiment.
Inorganic filler: An aluminum borate whisker (diameter 0.5 μm, length 20 μm) was used instead of glass fiber as the linear or foil-shaped inorganic filler 3.
From Table 2, it can be seen that in Example 5 in which aluminum borate whiskers were filled as solid particles with a solid epoxy resin, the viscosity was low and the flexural strength was low even when the same aluminum borate was filled three times higher than in Comparative Example 1. It was about twice as expensive. In Example 6, in which mica flakes were filled as a synthetic particle with a solid epoxy resin, the viscosity was low and the bending strength was about twice as high even in the case of Comparative Example 5 in which the same mica was filled as it was, even if the filling was three times higher. Further, in Examples 7 and 8, in which a part of the solid epoxy resin of Examples 5 and 6 was replaced with alumina fine particles, the viscosity was slightly increased but the bending strength was increased by about 30% as compared with Examples 5 and 6. . Further, Example 9 in which these three types of inorganic fillers were mixed and filled as solid particles with the solid epoxy resin 4 had a lower viscosity and bending than Comparative Examples 4 and 5 in which aluminum borate and mica were directly charged. The strength was more than three times higher.
From the above results, according to the present invention, it was possible to highly fill an inorganic filler having a large increase in viscosity while suppressing a rise in viscosity, and to increase the strength of the epoxy resin composition.
[0009]
[Table 2]
(Third embodiment)
Next, an example in which the epoxy resin composition of the present invention is used as a coil mold of an electric device will be described. FIG. 2 shows the shape of this sample. 2A and 2B are views showing the cast coil, wherein FIG. 2A is a plan view and FIG. 2B is a side sectional view. In the figure, 5 is a bobbin, 6 is a coil, and 7 is an epoxy resin composition.
In this sample, a coil 6 in which two kinds of polyester enamel wires of 1 mm in diameter are arranged and wound in parallel on a
The appearance and the cross section of the coil portion were observed, and evaluation was made based on the presence or absence of bubbles and unfilled portions between the mold resin portion and the coil wires, the porosity of the mold resin portion, and the partial discharge starting voltage at 60 Hz AC.
Table 3 shows the evaluation results. As a result of the observation, in the coil molds cast with the epoxy resin compositions of Examples 10 to 13 of the present invention, no bubbles or unfilled portions were observed, and the partial discharge inception voltage was high. In Comparative Examples 6 to 8 in which the inorganic filler having a large surface area was directly filled, bubbles and unfilled portions were observed, the porosity was 1% or more, and the partial discharge inception voltage was low. Therefore, the effectiveness of the present invention was confirmed. Was done.
[0011]
[Table 3]
(Fourth embodiment)
Next, as in the third embodiment, an example in which the epoxy resin composition of the present invention is used as a coil mold of an electric device and crack generation is evaluated will be described.
The shape of this sample is the same as that of the third embodiment. This sample is a bobbin 4 formed by laminating a silicon steel thin plate having a diameter of 30 mm to a thickness of 5 mm, and a coil 6 in which a type 1 polyester enameled wire having a diameter of 1 mm is arranged and wound so as to have an outer diameter of 40 mm. It was attached to a mold (not shown) having an internal volume of 7 mm in thickness, vacuum-molded with the epoxy resin composition 7 shown in Table 4, cured at 150 ° C. for 8 hours, and released from the mold. The material composition of the epoxy resin composition was the same as Examples 5 to 9 and Comparative Examples 4 and 5 shown in Table 2.
The appearance was observed and evaluated by the presence or absence of cracks in the mold resin.
Table 4 shows the evaluation results. As a result of the observation, no crack was observed in the coil mold cast with the epoxy resin compositions of Examples 14 to 18 of the present invention, whereas a comparative example in which an inorganic filler having a large specific surface area was filled as it was. In Nos. 9 and 10, cracks occurred, confirming the effectiveness of the present invention.
[0013]
[Table 4]
(Fifth embodiment)
Next, an example in which the epoxy resin composition of the present invention is applied to a thick cast product such as a bushing of an electric device will be described.
The synthetic particles 1 had a particle size distribution of 1 to 10 mm and a central particle diameter of 3 mm. Table 5 shows the compositions and viscosities of the epoxy resin composition of this example and the conventional epoxy resin composition. The material composition of the epoxy resin composition was the same as in Examples 1 to 4 and Comparative Examples 1 to 3 shown in Table 1, and the particle size distribution was 1 to 10 mm and the central particle diameter was 3 mm.
As shown in Table 5, the viscosity of Example 19, in which fine alumina particles were filled as a synthetic particle 1 with a solid epoxy resin, was low even if the same alumina was filled twice as much as Comparative Example 11 in which the same alumina particles were filled. In Example 20, in which the glass fiber was filled as a synthetic particle 1 with a solid epoxy resin, the viscosity was low even when the glass fiber was filled three times higher than in Comparative Example 12, in which the same glass fiber was filled as it was. In Example 21 in which mica flakes were filled as a synthetic particle 1 with a solid epoxy resin, the viscosity was low even when the same mica was charged as it was in Comparative Example 13 three times as high. Further, Example 22 in which these three kinds of inorganic fillers were mixed and filled as a synthetic particle 1 with a solid epoxy resin was more viscous than Comparative Examples 12 and 13 in which glass fiber or mica having a particularly large increase in viscosity was directly filled. Was low.
From the above results, the present invention enables the inorganic filler having a large increase in viscosity to be filled while suppressing the increase in viscosity even when the present invention is applied to a thick cast product. It could be fillable.
[0015]
[Table 5]
(Sixth embodiment)
Next, an example in which the epoxy resin composition of the present invention is evaluated by the strength of the epoxy resin composition for a thick cast product such as a bushing of an electric device will be described.
Synthetic particles 1 had a particle size distribution of 1 to 10 mm and a central particle size of 3 mm as in the fifth embodiment.
Table 6 shows the compositions, viscosities and flexural strengths of the epoxy resin composition of this example and the conventional epoxy resin composition. The material composition of the epoxy resin composition was the same as in Examples 5 to 9 and Comparative Examples 4 and 5 shown in Table 2, with a particle size distribution of 1 to 10 mm and a central particle diameter of 3 mm.
From Table 6, it can be seen that Example 23 in which aluminum borate whiskers were filled as solid particles with a solid epoxy resin had a low viscosity and a low flexural strength even when filled three times as high as Comparative Example 14 in which the same aluminum borate whiskers were filled. Was expensive. In Example 24, in which mica flakes were filled as synthetic particles with a solid epoxy resin, the viscosity was low and the flexural strength was high even if the mica flakes were filled three times as high as Comparative Example 15 in which the same mica flakes were filled as they were. In Example 25, in which a part of the solid epoxy resin of Example 23 was replaced with alumina fine particles, the viscosity was low and the flexural strength was high even when the same aluminum borate whisker was filled three times as high as Comparative Example 14 in which the same was filled. Was. In Example 26 in which part of the solid epoxy resin of Example 24 was replaced with alumina fine particles, the viscosity was low and the flexural strength was high even when the same mica flake was filled as it was in Comparative Example 15 three times as high as in Comparative Example 15. Further, in Example 27 in which these three kinds of inorganic fillers were mixed and filled as a synthetic particle with a solid epoxy resin, the viscosity was higher than Comparative Examples 14 and 15 in which glass fiber or mica having a particularly large increase in viscosity was directly filled. Low and high bending strength.
From the above results, according to the present invention, even in the particle size distribution for a thick cast product, it is possible to fill an inorganic filler having a large increase in viscosity, while suppressing an increase in viscosity. The filling material can be highly filled.
[0017]
[Table 6]
(Seventh embodiment)
Next, an example in which the epoxy resin composition of the present invention is used as a mold for a bushing, which is a thick part of an electric device, and the generation of bubbles and voids is evaluated will be described.
FIG. 3 shows the shape of this sample. FIGS. 3A and 3B are views showing the cast model bushing, in which FIG. 3A is a plan view and FIG. 3B is a side sectional view. Simulating a bushing, two constricted portions were provided on a cylinder having a diameter of 40 mm and a length of 60 mm. In this sample, an iron rod 8 having a diameter of 10 mm was attached to a mold (not shown), vacuum-molded with the epoxy resin composition 7 shown in Table 7, cured at 150 ° C. for 8 hours, and then released. The material composition of the epoxy resin composition was the same as Examples 19 to 22 and Comparative Examples 11 to 13 shown in Table 5.
Table 7 shows the evaluation results. The appearance and cross section were observed, and evaluation was made based on the presence or absence of bubbles and unfilled portions in the mold resin portion and the porosity of the mold resin portion.
As a result of the observation, in the mold of the coil cast with the epoxy resin compositions of Examples 28 to 31 of the present invention, no bubbles or unfilled portions were found, whereas an inorganic filler having a large specific surface area was used. In Comparative Examples 16 to 18 which were filled as they were, bubbles and unfilled portions were observed, and the porosity was 1% or more, thus confirming the effectiveness of the present invention.
[0019]
[Table 7]
(Eighth embodiment)
Next, an example in which the epoxy resin composition of the present invention is used as a mold for a bushing, which is a thick component of an electric device, and evaluated based on the presence or absence of cracks will be described.
The conditions of this sample are the same as those of the seventh embodiment except that the conditions of the composition such as the inorganic filler are different.
The material composition of the epoxy resin composition was the same as that of Examples 23 to 27 and Comparative Examples 14 and 15 shown in Table 6.
The appearance and cross section were observed and evaluated by the presence or absence of cracks in the mold resin portion.
Table 8 shows the evaluation results. As a result of the observation, no crack was observed in the coil mold cast with the epoxy resin compositions of Examples 32 to 36 of the present invention, whereas a comparative example in which an inorganic filler having a large specific surface area was directly filled was used. 19 and 20, cracks were observed, confirming the effectiveness of the present invention.
[0021]
[Table 8]
(Ninth embodiment)
In the present embodiment, an inorganic filler having a high thermal conductivity and a high aspect ratio, that is, an inorganic filler having a high effect of improving the thermal conductivity can be highly filled by suppressing an increase in viscosity.
The only difference from the first embodiment is that a shape memory alloy is used as a part of the inorganic filler and the particle size of the fine inorganic filler is the same as that of the first embodiment.
Shape memory alloy: nickel / titanium alloy (diameter 0.15 mm, average length 2 mm, transformation temperature 50-70 ° C.), nickel / titanium / copper alloy (diameter 0.2 mm, average length 2 mm, transformation temperature 50-80 ° C.) ), Nickel / titanium / iron alloy (diameter 0.15 mm, average length 2 mm, transformation temperature 50-70 ° C)
Particulate inorganic filler: alumina (central particle size 1 μm), alumina (central particle size 15 μm)
The temperature at the time of molding of this epoxy resin composition is maintained at a low viscosity by setting it to be equal to or lower than the melting temperature of the solid epoxy resin 4, and the curing temperature is set to be equal to or higher than the melting temperature of the solid epoxy resin 4 so that the solid epoxy resin 4 is melted. The liquid epoxy resin around the particles 1 can be homogenized, and the shape memory alloy 3 and the particulate inorganic filler 2 can be dispersed in the epoxy resin composition 7. Further, by setting the hardening temperature to be equal to or higher than the transformation temperature of the shape memory alloy 3, the shape of the bent shape memory alloy 3 can be restored and brought into contact with the nearby shape memory alloy 3.
The mixing of the synthetic particles 1 and the liquid epoxy resin is performed at 20 ° C. lower than the transformation temperature of the shape memory alloy 3 and the melting temperature of the solid epoxy resin 4, and the heat curing temperature of the epoxy resin composition is the transformation temperature of the shape memory alloy 3. And 150 ° C. higher than the melting temperature of the solid epoxy resin. The curing time was 8 hours.
Next, Table 9 shows the relationship between the composition, viscosity, and thermal conductivity of the epoxy resin composition of the present invention in which the particle size distribution of the synthetic particles 1 was 1 to 2 mm and the central particle size was 1.5 mm. As a comparative example of the present invention, Table 9 shows the relationship between the composition, the viscosity, and the thermal conductivity of the epoxy resin composition filled with the shape memory alloy alone and the epoxy resin composition filled with the conventional high thermal conductive ceramic particles.
From Table 9, it can be seen that Example 37 in which the composite particles of the nickel / titanium alloy and the solid epoxy resin were filled had a low viscosity even when three times as high as Comparative Example 21 in which the same nickel / titanium alloy was directly charged, and had a low thermal conductivity. The ratio was one digit higher than that of Comparative Example 21 and higher than that of Comparative Example 24 in which alumina particles were highly loaded. In Example 38, in which synthetic particles of a nickel / titanium / copper alloy and a solid epoxy resin were filled, the viscosity was low even in the case where the same nickel / titanium / copper alloy was filled three times as high as Comparative Example 22, and the thermal conductivity was low. The ratio was one digit higher than that of Comparative Example 22, and higher than that of Comparative Example 24 in which alumina particles were highly loaded.
In Example 39, which was filled with synthetic particles of a nickel / titanium / iron alloy and a solid epoxy resin, the viscosity was low even when the same nickel / titanium / iron alloy was filled three times as high as Comparative Example 23, and the thermal conductivity was low. The ratio was higher by one digit than that of Comparative Example 23, and was higher than that of Comparative Example 24 in which alumina particles were highly loaded. In Example 40 in which these three types of inorganic fillers were mixed and filled as synthetic particles with the solid epoxy resin 4, the same viscosity and thermal conductivity as those of Examples 21, 22, and 23 were obtained. In Example 41 in which part of the solid epoxy resin of Example 40 was replaced with alumina fine particles, the viscosity was slightly higher than Examples 37, 38, 39 and 40, but the thermal conductivity was higher. From the above results, according to the present invention, a linear shape memory alloy inorganic filler having a large increase in viscosity can be highly filled while suppressing a rise in viscosity, and the thermal conductivity of the epoxy resin composition can be increased. .
[0023]
[Table 9]
(Tenth embodiment)
Next, an example using the synthetic particles 1 filled with the foil-shaped shape memory alloy 3 will be described. A method for manufacturing a foil-shaped shape memory alloy will be described. The three types of linear shape memory alloys used in the ninth embodiment are cut into a length of about 0.3 mm, and heat-pressed under heating at 500 ° C. to form a foil having a thickness of 100 μm or less. Was memorized.
The method for producing the synthetic particles 1 and the method for mixing and curing with the liquid epoxy resin are the same as those in the first embodiment.
Next, Table 10 shows the relationship between the composition, viscosity, and thermal conductivity of the epoxy resin composition of the present invention in which the particle size distribution of the synthetic particles 1 was 1 to 2 mm and the central particle size was 1.5 mm. The composition of the material is the same as that of the example in Table 9, and only the shape of the shape memory alloy inorganic filler 3 differs. A comparative example of the present invention is the same as that of the ninth embodiment, and is shown in Table 9.
From Table 10, it can be seen that Example 42 in which the composite particles of the nickel / titanium alloy and the solid epoxy resin were filled had a low viscosity even when three times as high as Comparative Example 21 in which the same nickel / titanium alloy was directly charged, and had a low thermal conductivity. The ratio was one order of magnitude higher than that of Comparative Example 21 and higher than that of Comparative Example 24 in which alumina particles were highly loaded. In Example 43, in which synthetic particles of nickel / titanium / copper alloy and solid epoxy resin were filled, the viscosity was low even when the same nickel / titanium / copper alloy was filled three times as high as Comparative Example 22, and the thermal conductivity was low. The ratio was one digit higher than that of Comparative Example 22, and higher than that of Comparative Example 24 in which alumina particles were highly loaded. In Example 44, in which synthetic particles of a nickel / titanium / iron alloy and a solid epoxy resin were filled, the viscosity was low even when the same nickel / titanium / iron alloy was filled three times higher than in Comparative Example 23, and the thermal conductivity was low. The ratio was one digit higher than that of Comparative Example 23, and higher than that of Comparative Example 24 in which alumina particles were highly loaded. In Example 45 in which these three kinds of inorganic fillers were mixed and filled as solid particles with the solid epoxy resin 4, the same viscosity and thermal conductivity as those of Examples 42, 43, and 44 were obtained. In Example 46, in which a part of the solid epoxy resin of Example 45 was replaced with alumina fine particles, the viscosity was slightly higher than Examples 37, 38, 39, and 40, but the thermal conductivity was higher. From the above results, it was possible to highly fill the foil-like inorganic filler having a large increase in viscosity according to the present invention while suppressing the increase in viscosity, and to increase the thermal conductivity of the epoxy resin composition.
[0025]
[Table 10]
(Eleventh embodiment)
Next, an example in which the epoxy resin composition of the present invention is used as a coil mold of an electric device will be described. FIG. 4 shows the shape of this sample. FIGS. 4A and 4B are views showing the cast coil, wherein FIG. 4A is a plan view and FIG. 4B is a side sectional view. In this sample, a thermocouple 9 was attached to a
The evaluation was performed by connecting a resistor (not shown) and an AC power supply to the coil 6 in water at 25 ° C., applying an AC voltage of 100 V and 60 Hz, and measuring a change over time in temperature rise. Table 11 shows the evaluation results. The evaluation was made based on the temperature rise when the temperature change was saturated. The coils cast with the epoxy resin compositions of Examples 37 to 41 of the present invention had a temperature rise of several degrees, whereas the coils cast with the epoxy resin composition of the comparative example had a temperature rise of 10 degrees. Since the temperature was at least ℃, the effectiveness of the present invention was confirmed.
[0027]
[Table 11]
Incidentally, the shape memory alloy may be a nickel / titanium / cobalt alloy (transformation temperature 0 to -80 ° C.) when the resin temperature is controlled to be low. In addition, the diameter of the synthetic particles in this example was 1 mm or more, but if whiskers or scales of a shape memory alloy are used, the diameter of the synthetic particles may be about 100 μm, In this case, it goes without saying that the distance may be several mm to 10 mm.
[0029]
(Twelfth embodiment)
In the present embodiment, when filling the resin for molding the thick portion with inorganic particles having a large specific gravity, the viscosity is suppressed during molding to improve workability, and during heat curing, the resin has a large specific surface area. A filler, that is, an inorganic filler having a high effect of increasing the viscosity is dispersed and thickened to prevent sedimentation of the inorganic particles.
The difference from the first embodiment is only a part of the inorganic filler, and other materials are the same as those of the first embodiment.
The diameter of the synthetic particles 1 is 5 μm or more, which has a small increase in viscosity, and is preferably 200 μm or less for use as a mold resin for electric equipment.
Inorganic filler having a large specific surface area in the synthetic particles: fine particles of silica (Ageril, particle size 0.007 μm), alumina (polishing, average particle size 0.05 μm)
Inorganic particles to be filled in the liquid epoxy resin: alumina (spherical, average particle size 40 μm, specific gravity 3.9), fused silica (spherical, average particle size 15 μm, specific gravity 2.7)
FIG. 5 is a characteristic diagram showing a relationship between temperature and viscosity when the epoxy resin composition filled with the synthetic particles 1 is heated from room temperature. Since the synthetic particles 1 have a coarse particle size of 5 μm or more and a small specific surface area, the viscosity increases when the solid epoxy resin 4 is filled with a liquid epoxy resin at a melting temperature or lower, that is, when the solid epoxy resin 4 is not melted. Is low as in the case of filling with conventional inorganic particles, and does not impair molding workability. The temperature at the time of molding the epoxy resin composition is maintained at a low viscosity by setting the temperature at or below the melting temperature of the solid epoxy resin 4. The curing temperature is set to be equal to or higher than the melting temperature of the solid epoxy resin 4 of the synthetic particles 1, so that the liquid epoxy resin around the synthetic particles is homogenized, and fine particles having a large specific surface area, a foil-like or a linear inorganic filler are used. It can be dispersed in the composition to increase the viscosity.
The method for producing the synthetic particles 1 is the same as in the first embodiment.
Next, Table 12 shows the evaluation results of the composition, viscosity, and inorganic sedimentation. The viscosity was measured at a molding temperature of 40 ° C. and a curing temperature of 100 ° C. The evaluation was performed by cutting a cured product molded and cured into a mold (not shown) for producing a cube having a side of 10 mm into two upper and lower parts according to the placement at the time of molding, and weighing the burning residue at 500 ° C. for 1 hr. The content of the inorganic substance in the cured product was measured.
In the epoxy resin composition of this example, the particle size distribution of the synthetic particles 1 was 5 to 100 μm and the central particle size was 30 μm, assuming a particle size distribution toward a coil mold. As a comparative example, the composition of a conventional epoxy resin composition was also added.
From Table 12, the epoxy resin compositions of Examples 42 to 44 of the present invention have a low viscosity at a molding temperature of 40 ° C, but a viscosity at a curing temperature of 100 ° C higher than 40 ° C, The content of the inorganic substance hardly changed depending on the part of the cured product. On the other hand, in Comparative Examples 25 and 26 in which the inorganic particles were directly filled, the viscosity at 100 ° C. was extremely lower than 40 ° C., and the cured product showed remarkable sedimentation of the inorganic particles. The effectiveness was confirmed.
[0030]
[Table 12]
(Thirteenth embodiment)
In the present embodiment, a synthetic particle is filled with an inorganic filler having a high aspect ratio.
The only difference from the twelfth embodiment is a part of the particles, and the other conditions are the same as those in the twelfth embodiment.
As a linear or foil-like inorganic filler 3 having a large specific surface area in the synthetic particles 1, aluminum borate whiskers (0.5 to 1 μm in diameter, 10 to 30 μm in length) instead of the fine-particle inorganic filler 2 are synthesized. Mica flakes (average diameter 1-5 μm, aspect ratio 20-30) were used.
Table 13 shows the evaluation results of the composition, viscosity, and inorganic sedimentation. From Table 13, the epoxy resin compositions of Examples 45 to 47 of the present invention have low viscosity at the molding temperature of 40 ° C, but have higher viscosity at the curing temperature of 100 ° C than 40 ° C, The content of the inorganic substance hardly changed depending on the site. On the other hand, the cured products of Comparative Examples 25 and 26 in which the inorganic particles shown in Table 12 were directly filled had a viscosity at 100 ° C. which was much lower than 40 ° C., and the cured products showed remarkable sedimentation of the inorganic particles. Thus, the effectiveness of the present invention was confirmed.
[0032]
[Table 13]
(14th embodiment)
Next, an example in which the epoxy resin composition of the present invention is used as a mold for a bushing which is a thick part of an electric device will be described.
FIG. 3 shows the shape of this sample. In this sample, an iron rod 8 having a diameter of 10 mm was attached to a mold (not shown), vacuum-molded with the epoxy resin composition 7 shown in Table 14, cured at 150 ° C. for 8 hours, and then released. The material composition of the epoxy resin composition was the same as in Examples 43, 43, 45, and 46 and Comparative Examples 25 and 26 shown in Tables 12 and 13.
Table 14 shows the evaluation results. The molded / cured epoxy resin composition 7 of the simulated bushing is cut out from a 10 mm thick portion from the top and a 10 mm thick portion from the bottom in a placement manner at the time of molding, and the burning residue at 500 ° C. for 1 hr is weighed and cured. The inorganic content in the material was measured. As shown in Table 3, the bushing molds formed using the epoxy resin compositions of Examples 43 to 46 of the present invention showed little change in the inorganic content depending on the location, whereas Comparative Examples 27 and 28 in which the particles were filled as they were. The sedimentation of inorganic particles was markedly observed, confirming the effectiveness of the present invention.
[0034]
[Table 14]
By the way, the production of particles consisting of an inorganic filler and a solid epoxy resin involves dissolving an uncured or semi-cured solid epoxy resin with an organic solvent and mixing with the inorganic filler, removing the solvent, etc., solidifying and grinding. Alternatively, granulation may be performed by spray drying or mixing in supercritical carbon dioxide. In addition, the inorganic filler is not limited to alumina, glass fiber, and mica.In the form of particles, alumina, silica, silicon carbide, silicon nitride, aluminum nitride, magnesium borate, alumina, carbon, graphite, glass, various metals, and various types of heat are used. Plastics and various rubbers may be used, and in the linear form, aluminum borate, silicon carbide, silicon nitride, potassium titanate, magnesium borate, alumina, carbon, graphite, tyranno fiber, aramid fiber, etc., whisker, and in the form of foil, montmorillonite , Titanium oxide, aluminum nitride, metal foil, and the like.
[0036]
【The invention's effect】
As described above, the present invention has the following effects.
(1) The epoxy resin composition of the present invention is composed of an epoxy resin filled with synthetic particles having a particle diameter of 5 μm to 10 mm, preferably 10 μm to 200 μm, which comprises an inorganic filler and a solid epoxy resin. Is cured at a temperature equal to or higher than the melting temperature of the solid epoxy resin.
(2) The inorganic filler is fine particles or particles having a particle diameter of 2 μm or less, and the inorganic filler is a linear wire having a length of 1 μm or more or a foil having a thickness of 10 μm or less. Shape.
Therefore, an inorganic filler can be highly filled while suppressing an increase in viscosity, and an epoxy resin composition having low porosity, high strength, high toughness and high thermal conductivity can be obtained.
further
(3) An inorganic filler made of a shape memory alloy, and an uncured or semi-cured solid epoxy resin cured at a temperature higher than the transformation temperature of the shape memory alloy and higher than the melting temperature of the solid epoxy resin. It is.
(4) Further, the shape memory alloy has a linear shape having a length of 100 μm or more or a shape obtained by bending the same, and / or a foil shape having a thickness of 100 μm or less or a shape obtained by folding the same. Things.
Therefore, it is possible to highly fill the inorganic filler, which has a large improvement in the thermal conductivity with respect to the filling rate, by suppressing the increase in the viscosity, and to contact the inorganic filler with each other, so that the epoxy having a high thermal conductivity can be used. A resin composition can be obtained.
(5) The epoxy resin is filled with the synthetic particles and the inorganic particles, and the uncured or semi-cured solid epoxy resin is cured at a temperature equal to or higher than the melting temperature of the solid epoxy resin.
With the above configuration, good molding workability can be achieved, sedimentation of inorganic particles can be reduced even in a thick part, and a good thick cured product uniformly dispersed without sedimentation of an inorganic filler can be obtained. .
(6) In addition, the epoxy resin composition of the present invention is used for electric equipment as a molding material for electric equipment such as a coil, a bushing or an insulator using the molding material as a molding material.
With the above configuration, a high-performance electric device using this epoxy resin composition can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a cross section of particles mixed with an epoxy resin composition of the present invention.
FIGS. 2A and 2B are diagrams showing a coil cast with the epoxy resin composition of the present invention, wherein FIG. 2A is a plan view and FIG.
FIG. 3 is a view showing a simulated bushing cast with the epoxy resin composition of the present invention, wherein (a) is a plan view and (b) is a side sectional view.
FIG. 4 is a view showing a coil cast with the epoxy resin composition of the present invention, wherein (a) is a plan view and (b) is a side sectional view.
FIG. 5 is a characteristic diagram showing a relationship between temperature and viscosity of the epoxy resin composition of the present invention.
[Explanation of symbols]
1 synthetic particles
2 Fine inorganic filler
3 Inorganic fillers in linear or foil form
4 Solid epoxy resin
5 bobbins
6 coils
7 Epoxy resin composition
8 horizontal bars
9 Thermocouple
Claims (11)
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| JP2003039701A JP4284590B2 (en) | 2003-02-18 | 2003-02-18 | Method for producing epoxy resin composition |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009298900A (en) * | 2008-06-12 | 2009-12-24 | Denso Corp | Thermoconductive-adhesive and bonded structural body |
| CN101186742B (en) * | 2007-11-14 | 2010-07-07 | 哈尔滨工业大学 | Shape memory composite material and preparation method thereof |
| CN103992623A (en) * | 2014-06-11 | 2014-08-20 | 湖北华宁防腐技术股份有限公司 | Repairing material for hard rubber anticorrosive linings and preparation method thereof |
| CN105047275A (en) * | 2015-07-03 | 2015-11-11 | 安徽韵捷电子科技有限公司 | Top speed charging data line |
| US20160353570A1 (en) * | 2015-05-29 | 2016-12-01 | Samsung Electro-Mechanics Co., Ltd. | Resin composition for packaging and printed circuit board using the same |
| JP2019129121A (en) * | 2018-01-26 | 2019-08-01 | 株式会社日立産機システム | Electric apparatus |
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2003
- 2003-02-18 JP JP2003039701A patent/JP4284590B2/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101186742B (en) * | 2007-11-14 | 2010-07-07 | 哈尔滨工业大学 | Shape memory composite material and preparation method thereof |
| JP2009298900A (en) * | 2008-06-12 | 2009-12-24 | Denso Corp | Thermoconductive-adhesive and bonded structural body |
| CN103992623A (en) * | 2014-06-11 | 2014-08-20 | 湖北华宁防腐技术股份有限公司 | Repairing material for hard rubber anticorrosive linings and preparation method thereof |
| CN103992623B (en) * | 2014-06-11 | 2016-08-17 | 湖北华宁防腐技术股份有限公司 | A kind of patching material for vulcanie corrosion protective lining and preparation method thereof |
| US20160353570A1 (en) * | 2015-05-29 | 2016-12-01 | Samsung Electro-Mechanics Co., Ltd. | Resin composition for packaging and printed circuit board using the same |
| US10070519B2 (en) * | 2015-05-29 | 2018-09-04 | Samsung Electro-Mechanics Co., Ltd. | Resin composition for packaging and printed circuit board using the same |
| CN105047275A (en) * | 2015-07-03 | 2015-11-11 | 安徽韵捷电子科技有限公司 | Top speed charging data line |
| JP2019129121A (en) * | 2018-01-26 | 2019-08-01 | 株式会社日立産機システム | Electric apparatus |
| JP7191517B2 (en) | 2018-01-26 | 2022-12-19 | 株式会社日立産機システム | electrical equipment |
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