JP4245244B2 - Insulated wire - Google Patents
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- JP4245244B2 JP4245244B2 JP33953699A JP33953699A JP4245244B2 JP 4245244 B2 JP4245244 B2 JP 4245244B2 JP 33953699 A JP33953699 A JP 33953699A JP 33953699 A JP33953699 A JP 33953699A JP 4245244 B2 JP4245244 B2 JP 4245244B2
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Description
【０００１】
【発明の属する技術分野】
本発明は、各種電気、電子機器用のコイルの巻線などに好適に使用される絶縁電線に関するものである。
【０００２】
【従来の技術】
近年、たとえば自動車用などの各種電気、電子機器の小型化、軽量化の傾向にともなって、これらの機器に用いるコイルなどの部品についても、これまでより小型、軽量で、しかも高性能を保ちつつ低コスト化することが要求されるようになってきた。
そしてこの要求に対応するために、コイルを形成する巻線としての絶縁電線（導体を絶縁皮膜で被覆したいわゆるエナメル電線）を、これまでよりも小さいコアに、高密度でしかも生産性をあげるべく高速で巻きつける必要が生じ、巻きつけ時に、絶縁電線の絶縁皮膜が損傷するなどして、機器の電気特性が低下したり、あるいは生産の歩留まりが低下したりするという問題が発生していた。
【０００３】
そこでこの問題に対処するために、絶縁電線の絶縁皮膜の
(a) 機械的強度を向上させる、
(b) 可とう性を向上させる、
(c) 表面の滑り性をよくする、
(d) 導体との密着性を向上させる、
といった対策が検討されている。
【０００４】
たとえば▲１▼ 特開平６−１９６０２５号公報には、ポリアミドイミド、ポリイミド、芳香族ポリアミドなどの耐熱性樹脂にて形成した絶縁皮膜の引張強さ、引張弾性率、密着力、ピアノ線に対する静摩擦係数などを、樹脂の分子設計によって所定の値に設定することにより、絶縁皮膜の耐加工性を向上させて、巻きつけ時に損傷などが生じるのを抑制することが記載されている。
また▲２▼ 特開昭６２−５８５１９号公報には、あらかじめ絶縁皮膜を被覆、形成した後の導体を、巻線の密度を向上させるべく、圧延加工によって平角状に成形して平角巻線を製造するにあたり、圧延および熱処理による絶縁皮膜の加工劣化と耐熱衝撃性の低下とを防止するために、絶縁皮膜を形成する絶縁塗料（ワニス）として、ポリエーテルイミドに、ポリエステルイミドと、フェノール系化合物で閉塞したポリイソシアネートブロック体とを添加したものを使用することが記載されている。
【０００５】
さらに▲３▼ 特開昭５８−３４８２８号公報には、ポリアミドイミドとポリエーテルイミドとをブレンドすることによって、ポリエーテルイミドと同等の機械的特性を持ち、しかも耐溶剤性、耐摩耗性、長期耐熱性にすぐれた材料を得ることが示されている。
【０００６】
【発明が解決しようとする課題】
しかし、上記のうち▲１▼の技術では、前記(a)(c)(d)を考慮して絶縁皮膜を構成しているものの、(b)の可とう性は必ずしも十分でない。
また、▲２▼の技術においては、ポリエーテルイミドの可とう性と、ポリエステルイミドの耐熱性および導体に対する密着性と、フェノール系化合物で閉塞したポリイソシアネートブロック体のろう着性とを組合わせることにより、前述したように平角に圧延する際の絶縁皮膜の加工劣化と耐熱衝撃性低下の問題を解決しているが、ポリエステルイミドの破断時伸びが十分ではないため、やはり皮膜の可とう性が十分とはいえない。
【０００７】
さらに▲３▼において得られるブレンド材料は、たとえば同公報の第II表にみるようにいずれもガラス転移温度が低いために、高い耐熱性が要求される巻線用の皮膜材料としては、耐熱性が不十分である。
以上のように先行技術▲１▼〜▲３▼はいずれも、それぞれの技術レベルでは所定の課題を解決していると考えられるものの、高い耐熱性を保持しながらこれまでよりもさらにすぐれた耐加工性、すなわち圧延加工や巻線加工に対する耐性を得るためには、十分な特性を有しているとは言えない。
【０００８】
これは、上記の先行技術がいずれも、基本的に単層構造で、種々の材料を組合わせることによって絶縁皮膜に相異なる複数の特性を持たせようとしているところに、技術的な限界があるためと考えられる。
そこで発明者らは、絶縁皮膜を積層構造とするとともに、各層で樹脂の構成を違えて、それぞれの層に相異なる特性を付与することによって、単層構造では得られないすぐれた特性を有する絶縁電線を製造することを検討した。
【０００９】
そして先に、ガラス転移温度が２５０℃以上である樹脂からなる第１絶縁層と、ポリアミドイミドに、ガラス転移温度１４０℃以上の熱可塑樹脂を配合した第２絶縁層とを、導体上にこの順に積層、被覆して積層構造の絶縁皮膜を形成すると、高い耐熱性を保持しながら、これまでよりもさらにすぐれた耐加工性を有する絶縁電線が得られることを見出したが、かかる構成では、たとえばコイル加工時に絶縁電線の端末を溶接などによって接合する工程で、接合部付近の絶縁皮膜が接合の熱によって発泡したり、あるいはその変色長さが長くなったりして接合を妨げるという新たな問題を生じることが明らかとなった。
【００１０】
本発明の目的は、厳しい圧延加工や巻線加工などを行なっても皮膜に損傷などを生じないすぐれた耐加工性と、ポリアミドイミドと同等の高い耐熱性とを有し、しかも絶縁電線の端末を接合する工程で、接合部付近の絶縁皮膜が接合の熱などによって発泡したり、あるいはその変色長さが長くなったりしないために接合性にもすぐれた、新規な絶縁電線を提供することを目的としている。
【００１１】
【課題を解決するための手段および発明の効果】
上記課題を解決するための、本発明の絶縁電線は、
(1) ポリアミドイミド、およびポリイミドのうちの少なくとも一方からなる第１絶縁層と、
(2) ポリアミドイミドＡに、ガラス転移温度１４０℃以上のポリエーテルイミドＢを、重量比Ａ／Ｂで表してＡ／Ｂ＝７０／３０〜３０／７０の割合で配合してなる第２絶縁層と
をこの順に被覆、積層することによって、導体上に、上記第１絶縁層の膜厚Ｔ1と、第２絶縁層の膜厚Ｔ2との比Ｔ1／Ｔ2がＴ1／Ｔ2＝５／９５〜４０／６０の範囲内で、かつ上記第１絶縁層および第２絶縁層のもとになるワニスに由来する残留溶剤量が絶縁皮膜総量の０．０５重量％以下である絶縁皮膜を形成したことを特徴とするものである。
【００１２】
かかる本発明によって前記の課題を解決できる理由は、以下のとおりである。
1) ポリアミドイミド、およびポリイミドのうちの少なくとも一方からなり、耐熱性と、導体に対する密着性とにすぐれた第１絶縁層の上に、ポリアミドイミドを含有するため第１絶縁層との密着性にすぐれるとともに、当該ポリアミドイミドＡに対して、重量比Ａ／Ｂで表してＡ／Ｂ＝７０／３０〜３０／７０の割合でポリエーテルイミドＢを含有するため可とう性にもすぐれた第２絶縁層を積層することにより、絶縁皮膜に、導体に対する良好な密着性、および高い可とう性と、それによってもたらされる、厳しい圧延加工や巻線加工に耐え得る高い耐加工性とを付与することができる。
2) 上記のように第２絶縁層におけるポリエーテルイミドの配合量を規定し、かつポリエーテルイミドのガラス転移温度を１４０℃以上とするとともに、第１および第２の絶縁層の膜厚Ｔ1、Ｔ2の比Ｔ1／Ｔ2を５／９５〜４０／６０の範囲とすることにより、上述した高い可とう性を維持しつつ、絶縁皮膜全体としての耐熱性を、ポリアミドイミドと同等の高いレベルに保持することができる。
【００１３】
なお耐熱性は、後述する方法で測定された熱軟化温度で評価され、本発明においては４００℃以上であるのが好ましい。
3) 上記のように第１および第２の絶縁層の積層構造として導体に対する良好な密着性を確保し、また第２絶縁層におけるポリエーテルイミドの配合量を規定し、ポリエーテルイミドのガラス転移温度を高くし、かつ第１および第２の絶縁層の膜厚の比を規定して、絶縁皮膜全体としての耐熱性をポリアミドイミドのレベルに保持するとともに、上記第１絶縁層および第２絶縁層のもとになるワニスに由来する絶縁皮膜全体の残留溶剤量を、絶縁皮膜総量の０．０５重量％以下とすることにより、絶縁電線の端末を接合する工程で、接合部付近の絶縁皮膜が接合の熱などによって発泡したり、あるいはその変色長さが長くなったりするのをこれまでよりも確実に防止して、その接合性を向上することができる。つまり絶縁皮膜の接合性を向上するためには、発泡の原因である残留溶剤量の制御と、絶縁皮膜自体の耐熱性、および導体に対する密着性を向上することとが必要である。
【００１４】
なお本明細書では残留溶剤量を、後述する評価方法に基づいて、ガスクロマトグラフィーによって測定した値でもって表すこととする。
【００１５】
【発明の実施の形態】
以下に、本発明を説明する。本発明の絶縁電線は、前記のように
(1) ポリアミドイミド、およびポリイミドのうちの少なくとも一方からなる第１絶縁層と、
(2) ポリアミドイミドに、ガラス転移温度１４０℃以上のポリエーテルイミドを配合してなる第２絶縁層と
をこの順に被覆、積層することによって、導体上に、積層構造の絶縁皮膜を形成したものである。
【００１６】
このうち(1)の第１絶縁層が、上記のようにポリアミドイミド、およびポリイミドのうちの少なくとも一方からなるというのは、かかる第１絶縁層が、樹脂分としてポリアミドイミド、および／またはポリイミドを含有するが、第２絶縁層のように熱可塑性樹脂を含有しないことを意味する。ただしこの記載は、当該第１絶縁層が、たとえば着色剤などの、後述する各種の添加剤を含有することを妨げるものではない。
【００１７】
上記第１絶縁層は、従来の単層構造の絶縁皮膜と同様に、樹脂分としてポリアミドイミド、および／またはポリイミドを含有する第１絶縁層用のワニスの塗布、焼き付けによって形成される。
かかる第１絶縁層用のワニスのうち、樹脂分としてポリアミドイミドを含有するものは、
(A) ジイソシアネート成分と酸成分とを重合させる、
(B) ジアミン成分と酸成分とを反応させた反応生成物を、さらに略等モル量のジイソシアネート成分と重合させる、
(C) 酸クロライドを含む酸成分とジアミン成分とを重合させる、
などの従来公知の製造方法によって製造される。
【００１８】
また、樹脂分としてポリイミドを含有する第１絶縁層用のワニスは、
(D) ジアミン成分と酸無水物成分とを重合させる、
などの、これも従来公知の製造方法によって製造される。
さらに樹脂分としてポリアミドイミドとポリイミドの両方を含有するワニスは、上記両者を配合するなどして製造される。
第１絶縁層用のワニスのうち、ポリアミドイミド系のワニスの好適な例としては、これに限定されないがたとえば、ジイソシアネート成分としてのジフェニルメタンジイソシアネートと、酸成分としてのトリメリット酸無水物とを使用して製造されたもの〔具体例としては日立化成（株）製の商品名ＨＩ−４００、ＨＩ−４０５，ＨＩ−４０６など〕があげられる。
【００１９】
また、ポリイミド系のワニスの好適な例としては、これに限定されないがたとえば、ジアミン成分としてのジアミノジフェニルエーテルと、酸無水物成分としてのピロメリット酸無水物とを使用して製造されたもの〔具体例としてはＩＳＴ社製の商品名ＰｙｒｅＭＬ、東レデュポン社製の商品名トレニースなど〕があげられる。
第１絶縁層の上に積層、被覆される第２絶縁層は、前記のようにポリアミドイミドＡに、ガラス転移温度１４０℃以上のポリエーテルイミドＢを、重量比Ａ／Ｂで表してＡ／Ｂ＝７０／３０〜３０／７０の割合で配合してなるものである。
【００２０】
上記第２絶縁層を形成するポリアミドイミドとしては、第１絶縁層で使用したのと同様のものがあげられる。
また、上記ポリアミドイミドに配合されるポリエーテルイミドは、ガラス転移温度が１４０℃以上である必要がある。また、とくに伸び率が高いものが好ましい。
【００２１】
ガラス転移温度１４０℃以上のポリエーテルイミドは、上記ポリアミドイミドと組み合わせた際に、耐熱性と、とくに平角巻線として使用すべく圧延加工する際の耐加工性とにすぐれた第２絶縁層を形成できる上、コスト面でも有利である。
上記第２絶縁層における、ポリアミドイミドへのポリエーテルイミドの配合割合が前記の範囲に限定されるのは、以下の理由による。
【００２２】
すなわちポリエーテルイミドの配合割合が前記の範囲未満では、第２絶縁層の可とう性が低下するために、絶縁皮膜全体としての可とう性も低下する。このため、絶縁皮膜の耐加工性が低下して、厳しい圧延加工や巻線加工などを行った際に損傷などを生じやすくなり、機器の電気特性の低下、生産の歩留まりの低下といった問題を生じる原因となる。
一方、ポリエーテルイミドの配合割合が前記の範囲を超えた場合には、絶縁皮膜の全体としての耐熱性が低下して、前述した熱軟化温度４００℃以上といった耐熱性の基準を満足することができないために、絶縁電線を、高い耐熱性が要求される巻線に使用することができなくなる。また、絶縁電線の端末を接合する工程で、接合の熱などによって、接合部付近の絶縁皮膜の変色長さが長くなって、絶縁電線の接合性が低下するという問題も生じる。
【００２３】
なお、絶縁皮膜に高い耐加工性、耐熱性および良好な接合性を付与することを考慮すると、上記第２絶縁層における、ポリアミドイミドＡへのポリエーテルイミドＢの配合割合は、前記の範囲でもとくに重量比Ａ／Ｂで表してＡ／Ｂ＝６５／３５〜４５／５５程度であるのが好ましく、Ａ／Ｂ＝６５／３５〜５５／４５程度であるのがさらに好ましい。
第２絶縁層は、先の第１絶縁層と同様にして形成される。すなわち樹脂分として、ポリアミドイミドに所定量のポリエーテルイミドを配合した第２絶縁層用のワニスを、先に第１絶縁層を形成した上に塗布、焼き付けすることによって第２絶縁層が形成される。
【００２４】
かかる第２絶縁層用のワニスとしては、たとえば
(D) それぞれの樹脂を別個に溶剤に溶解した溶液を混合する、
(E) それぞれの樹脂を同時に同じ溶剤に溶解して混合する、
(F) 一方の樹脂を溶剤に溶解後、もう一方の樹脂を添加して溶解、混合する、
(G) 一方の樹脂を溶解した後、その溶液中で、もう一方の樹脂を合成する、
といった種々の方法によって製造したものが、いずれも使用可能である。
【００２５】
上記第１および第２の絶縁層の膜厚や、両層を合計した、絶縁皮膜の全体としての膜厚は、それぞれ絶縁電線の用途、形状、寸法などに応じて、適宜の値に設定することができる。
ただし本発明においては、上記第１および第２の絶縁層の膜厚Ｔ1、Ｔ2の比Ｔ1／Ｔ2が、前述したように５／９５〜４０／６０の範囲に限定される。この理由は以下の通りである。
【００２６】
すなわち、上記の範囲よりも第１絶縁層の占める割合が大きい場合には、絶縁皮膜の全体としての可とう性が低下するため耐加工性も低下して、厳しい圧延加工や巻線加工などを行った際に損傷などを生じやすくなり、機器の電気特性の低下、生産の歩留まりの低下といった問題を生じる原因となる。
一方、上記の範囲よりも第２絶縁層の占める割合が大きい場合には、絶縁皮膜の全体としての耐熱性が低下して、前述した熱軟化温度４００℃以上といった耐熱性の基準を満足することができないために、絶縁電線を、高い耐熱性が要求される巻線などの用途に使用できなくなるという問題を生じる。また、上記のように絶縁皮膜の耐熱性が低下する上、第１絶縁層による、絶縁皮膜の導体への密着性を確保する効果も不十分となるために、絶縁電線の端末を接合する工程で、接合の熱などによって、接合部付近の絶縁皮膜の変色長さが長くなって、絶縁電線の接合性が低下するという問題も生じる。
【００２７】
なお、絶縁皮膜に高い耐加工性、耐熱性、導体への密着性および良好な接合性を付与することを考慮すると、第１および第２の絶縁層の膜厚Ｔ1、Ｔ2の比Ｔ1／Ｔ2は、前記の範囲内でもとくに５／９５〜２５／７５程度であるのが好ましく、１０／９０〜２０／８０程度であるのがさらに好ましい。
また前記のように第１および第２の絶縁層の厚みはとくに限定されないが、それぞれ０．００１〜０．１００ｍｍ程度であるのが好ましい。
【００２８】
上記第１および第２の絶縁層はそれぞれ単層構造であってもよいし、組成（たとえば第１絶縁層の場合は使用しているポリアミドイミドやポリイミドの種類や添加剤の量など、また第２絶縁層の場合は使用しているポリアミドイミドやポリエーテルイミドの種類、両者の配合割合、添加剤の量など）の異なる２層以上の積層構造であってもよい。
たとえば第１絶縁層が積層構造である場合には、その合計の膜厚と、第２絶縁層の膜厚とが前記の範囲内となるように、当該第１絶縁層を構成する各層の厚みを調整すればよい。また同様に、第２絶縁層が積層構造である場合には、その合計の膜厚と、第１絶縁層の膜厚とが前記の範囲内となるように、当該第２絶縁層を構成する各層の厚みを調整すればよい。
【００２９】
第１および第２の絶縁層には、前述したように、たとえば顔料、染料などの着色剤、無機または有機のフィラー、潤滑剤などの各種の添加剤を、それぞれの層の特性を損なわない範囲で含有させることもできる。
上記第１および第２の絶縁層からなる絶縁皮膜は、導体と第１絶縁層との間にプライマー層を有していてもよいし、第２絶縁層の上、すなわち絶縁皮膜の最表層に表面潤滑層を有していてもよい。
【００３０】
かかる表面潤滑層は、たとえば流動パラフィンや固形パラフィンなどを塗布したり、各種ワックス、ポリエチレン、フッ素樹脂、シリコーン樹脂などの潤滑剤を第２絶縁層上に直接に製膜するか、あるいは製膜性を有するバインダー樹脂で結着した状態で製膜することによって形成される。
絶縁皮膜は、前記第１絶縁層および第２絶縁層のもとになるワニスに由来する残留溶剤量が、絶縁皮膜総量の０．０５重量％以下である必要がある。
【００３１】
残留溶剤量がこの範囲を超えた場合には、前述したように、絶縁皮膜が導体に対する良好な密着性と高い耐熱性とを兼ね備えていたとしても、絶縁電線の端末を接合する工程で、接合部付近の絶縁皮膜が接合の熱などによって発泡しやすくなって、絶縁電線の接合性が低下するという問題を生じる。
なお絶縁皮膜の残留溶剤量は、上記の範囲内でも０.０１重量％以下が好ましく、小さければ小さいほど好ましい。とくに、残留溶剤量が限りなく０％に近いのが理想的であるが、上記の範囲内であれば、絶縁皮膜が発泡などを生じない、良好な接合性を有する絶縁電線を製造することができる。
【００３２】
絶縁皮膜の残留溶剤量を上記の範囲に調整するには、当該絶縁皮膜を被覆、形成した絶縁電線を、たとえば窒素などの不活性ガス雰囲気中で熱処理してやればよい。
熱処理の条件はとくに限定されないが、２２０℃以上の温度で５時間以上、熱処理するのが好ましい。熱処理の温度がこれより低いか、または時間がこれより短い場合には熱処理が不十分で、絶縁皮膜の残留溶剤量を、絶縁皮膜総量の０．０１重量％以下に抑えることができず、絶縁電線の端末を接合する工程で、接合部付近の絶縁皮膜が接合の熱などによって発泡しやすくなって、絶縁電線の接合性が低下するおそれがある。
【００３３】
また上記絶縁皮膜は、その可とう性を考慮すると、破断伸びが５０％以上であるのが好ましい。
絶縁皮膜を被覆、形成するための導体としては、銅やアルミニウムなどからなる、絶縁電線に通常に用いられる種々の導体が、いずれも使用可能であるが、とくに酸素含有量１０ｐｐｍ以下の低酸素銅（無酸素銅を含む）にて形成された導体が、好適に使用される。
【００３４】
かかる低酸素銅製の導体を使用した場合には、絶縁電線の端末を接合する工程で、接合の熱などによって導体が加熱された際に、当該導体から発生するガス（酸素）の量を著しく少なくできるので、導体上の絶縁皮膜の発泡がさらに抑制されて、絶縁電線の接合性がさらに向上するという利点がある。
本発明の絶縁電線は、その用途などに応じて、丸線などの従来公知の種々の形状とすることができるが、とくに前述したように巻線の密度を向上させるべく、絶縁皮膜を被覆、形成した後の導体（通常は丸線）を、圧延加工によって平角状に成形して平角巻線とするのが好ましい。
【００３５】
この際、本発明の構成によれば、前記のように絶縁皮膜が、導体への密着性および可とう性と、それによってもたらされる圧延加工に対する耐性とにすぐれるために、当該圧延加工によって損傷したりしない上、圧延加工後も、丸線と同様な可とう性試験に耐えることができる、すぐれた可とう性と、導体に対する良好な密着性とを保持し、巻線加工に対する耐性にもすぐれるため、当該巻線加工時に損傷したりすることもない。したがって本発明によれば、機器の電気特性の低下、生産の歩留まりの低下といった問題を生じない良好な平角巻線を得ることができる。
【００３６】
圧延加工の具体的な方法としては、上記のように絶縁皮膜を被覆、形成した後の導体（丸線）を、たとえば圧延ローラによって文字通り圧延するか、あるいはカセットローラーダイスに通して引き抜いて圧延するなどの方法があげられる。
【００３７】
【実施例】
以下に本発明を、実施例、比較例に基づいて説明する。
実施例１
酸素含有量３ｐｐｍの低酸素銅にて形成された、直径２ｍｍφの丸線状の導体の上に、まず第１絶縁層用のワニスとしてのポリアミドイミドワニス〔前出の、日立化成（株）製の商品名ＨＩ−４００〕を常法にて塗布、焼き付けして、膜厚Ｔ1＝０．０１ｍｍの第１絶縁層を被覆、形成した。
【００３８】
つぎに、上記と同じポリアミドイミドワニス〔日立化成（株）製の商品名ＨＩ−４００、樹脂分含量２５重量％〕２４０重量部と、ポリエーテルイミド〔日本ジーイープラスチックス（株）製の商品名ウルテム１０００、ガラス転移温度２２０℃〕４０重量部とを配合するとともに、全体の樹脂分含量が２０重量％になるように、Ｎ−メチル−２−ピロリドンによって希釈して調製した第２絶縁層用のワニス〔ワニス中に含まれるポリアミドイミドＡと、ポリエーテルイミドＢとの配合割合（重量比）Ａ／Ｂ＝６０／４０〕を、上記第１絶縁層の上に、やはり常法にて塗布、焼き付けして、膜厚Ｔ2＝０．０４ｍｍの第２絶縁層を被覆、積層して２層構造の絶縁皮膜を形成した。両絶縁層の膜厚の比Ｔ1／Ｔ2＝２０／８０であった。また、この時点での仕上り径は２．１ｍｍであった。
【００３９】
つぎに、上記のように絶縁皮膜を被覆、形成した導体をカセットローラーダイスに通して引き抜きくことで、縦方向および横方向から圧延したのち、窒素中で２４０℃で６時間、熱処理して、絶縁電線としての平角巻線を製造した。
実施例２〜７、比較例１、２
第２絶縁層用のワニスにおけるポリアミドイミドＡとポリエーテルイミドＢとの配合割合（重量比）Ａ／Ｂが８５／１５（比較例１）、７０／３０（実施例２）、６５／３５（実施例３）、５５／４５（実施例４）、５０／５０（実施例５）、４０／６０（実施例６）、３０／７０（実施例７）、または１５／８５（比較例２）となるように、ポリアミドイミドワニスに対するポリエーテルイミドの配合量を調整したこと以外は実施例１と同様にして、絶縁電線としての平角巻線を製造した。
【００４０】
実施例８、比較例３
熱処理の条件を２００℃で６時間（比較例３）、または２２０℃で６時間（実施例８）としたこと以外は実施例１と同様にして、絶縁電線としての平角巻線を製造した。
実施例９
導体として、酸素含有量２００ｐｐｍのタフピッチ銅にて形成された、直径２ｍｍφの丸線状のものを使用したこと以外は実施例１と同様にして、絶縁電線としての平角巻線を製造した。
【００４１】
比較例４
実施例１で使用したのと同じ導体上に、前出のポリアミドイミドワニスを常法にて塗布、焼き付けして、膜厚０．０５ｍｍの単層構造の絶縁皮膜を被覆、形成したこと以外は実施例１と同様にして、絶縁電線としての平角巻線を製造した。
比較例５
実施例１で使用したのと同じ導体上に、実施例１で作製した第２絶縁層用のワニスを常法にて塗布、焼き付けして、膜厚０．０５ｍｍの単層構造の絶縁皮膜を被覆、形成したこと以外は実施例１と同様にして、絶縁電線としての平角巻線を製造した。
【００４２】
実施例１０
第１絶縁層の膜厚Ｔ1＝０．００５ｍｍ、第２絶縁層の膜厚Ｔ2＝０．０４５ｍｍ、両絶縁層の膜厚の比Ｔ1／Ｔ2＝１０／９０としたこと以外は実施例１と同様にして、絶縁電線としての平角巻線を製造した。
実施例１１
第１絶縁層の膜厚Ｔ1＝０．０１５ｍｍ、第２絶縁層の膜厚Ｔ2＝０．０３５ｍｍ、両絶縁層の膜厚の比Ｔ1／Ｔ2＝３０／７０としたこと以外は実施例１と同様にして、絶縁電線としての平角巻線を製造した。
【００４３】
比較例６
第１絶縁層の膜厚Ｔ1＝０．０２５ｍｍ、第２絶縁層の膜厚Ｔ2＝０．０２５ｍｍ、両絶縁層の膜厚の比Ｔ1／Ｔ2＝５０／５０としたこと以外は実施例１と同様にして、絶縁電線としての平角巻線を製造した。
実施例１２
実施例１で使用したのと同じ導体上に、第１絶縁層用のワニスとしてのポリイミドワニス〔前出の、ＩＳＴ社製の商品名ＰｙｒｅＭＬ〕を常法にて塗布、焼き付けして、膜厚Ｔ1＝０．０１ｍｍの第１絶縁層を被覆、形成したこと以外は実施例１と同様にして、絶縁電線としての平角巻線を製造した。
【００４４】
上記各実施例、比較例で作製した絶縁電線（平角巻線）について、それぞれ下記の試験を行って、その特性を評価した。
残留溶剤量の測定
絶縁電線を、炉温３５０℃の加熱炉に入れて３分放置した後、炉内に発生したガスをサンプリングし、ガスクロマトグラフィー（ＧＬサイエンス社製）にて溶剤量を定量したのち、サンプル中の絶縁皮膜総量に対する割合を計算して、残留溶剤量（重量％）とした。
【００４５】
引張試験
絶縁電線から導体をエッチング除去して残った絶縁皮膜を、引張試験機を用いてゲージ長２０ｍｍ、引張速度１０ｍｍ／分の条件で引張試験した際の破断伸び（％）を求めた。
接合性試験
長さ１５０ｍｍの絶縁電線をサンプリングし、その両端末を、それぞれ５ｍｍずつ皮膜剥離した。そして、一方の端末を接地するとともにもう一方の端末の先端部に２ｍｍの間隔をあけて溶接トーチを置き、１２０Ａで０．２秒間、アーク放電させて、絶縁電線の端末を溶解させた。そして溶解部分の付近における絶縁皮膜の変色長さ（ｍｍ）と、絶縁皮膜の発泡の有無とによって接合性を評価した。なお試験に際しては、溶解部に、毎分およそ１５リットルのＡｒガスを流した。
【００４６】
一般特性試験
日本工業規格ＪＩＳ Ｃ ３００３「エナメル銅線及びエナメルアルミニウム線試験方法」にしたがって、エッチワイズ２ｍｍ、フラットワイズ２ｍｍ、熱軟化温度（℃）、および絶縁破壊電圧（ｋＶ）を測定した。なおエッチワイズ２ｍｍおよびフラットワイズ２ｍｍの評価基準は下記の通りとした。
○：絶縁皮膜に割れなし（可とう性良好）
△：一部割れあり（可とう性やや不良）
×：割れあり（可とう性不良）
結果を表１、表２に示す。
【００４７】
【表１】
【表２】
両表より、ポリアミドイミドワニスにて単層の絶縁皮膜を形成した比較例４は可とう性が悪く、また第２絶縁層用のワニスにて単層の絶縁皮膜を形成した比較例５は耐熱性が不充分であることが判明した。
また、第１および第２の絶縁層からなる２層構造の絶縁皮膜を有していても、第２絶縁層におけるポリエーテルイミドの配合割合が本発明で規定した範囲未満であった比較例１は可とう性が低下し、逆にポリエーテルイミドの配合割合が本発明で規定した範囲を超えた比較例２は可とう性と耐熱性が低下することが判った。
【００５０】
また、絶縁皮膜の残留溶剤量が０．０５重量％を超えた比較例３と、０.０５重量％以下であった実施例８とから、残留溶剤量が多いほど接合性が低下することが判った。
さらに第１および第２の絶縁層の膜厚比が、本発明で規定した範囲に比べて第１絶縁層の膜厚が大きい方に外れた比較例６は可とう性と接合性が低下することが判明した。
【００５１】
これに対し、第１および第２の絶縁層からなる２層構造の絶縁皮膜を有し、そのうち第２絶縁層におけるポリエーテルイミドＢの配合割合が、ポリアミドイミドＡに対する重量比Ａ／Ｂで表してＡ／Ｂ＝７０／３０〜３０／７０の範囲内であるとともに、上記第１および第２の絶縁層の、膜厚の比Ｔ1／Ｔ2＝５／９５〜４０／６０の範囲内で、かつ残留溶剤量が絶縁皮膜総量の０．０１重量％以下である実施例１〜１２はいずれも、圧延加工して平角巻線とする際の耐加工性にすぐれる上、加工後の可とう性、耐熱性、および接合性も良好であることが確認された。
【００５２】
また各実施例を比較すると、重量比Ａ／Ｂ＝６５／３５〜５５／４５の範囲内であるのが、とくに接合性の点で好ましいこと、また導体の酸素濃度は１０ｐｐｍ以下であるのが、やはり接合性の点で好ましいことが判った。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an insulated wire suitably used for winding of coils for various electric and electronic devices.
[0002]
[Prior art]
In recent years, with the trend toward miniaturization and weight reduction of various electric and electronic devices for automobiles, etc., parts such as coils used in these devices are also smaller and lighter than ever, while maintaining high performance. There has been a demand for cost reduction.
In order to meet this demand, an insulated wire (so-called enameled wire with a conductor covered with an insulating film) as a winding forming a coil is placed on a smaller core than before, with high density and increased productivity. There is a need to wind at a high speed, and the insulation film of the insulated wire is damaged at the time of winding, which causes a problem that the electrical characteristics of the device are lowered or the production yield is lowered.
[0003]
Therefore, in order to cope with this problem, the insulation film of the insulated wire
(a) improve mechanical strength,
(b) improve flexibility,
(c) improve the slipperiness of the surface,
(d) improve adhesion to the conductor,
Such measures are being studied.
[0004]
For example, (1) Japanese Patent Application Laid-Open No. 6-196025 discloses the tensile strength, tensile elastic modulus, adhesion, and coefficient of static friction with respect to a piano wire of an insulating film formed of a heat-resistant resin such as polyamideimide, polyimide, and aromatic polyamide. Is set to a predetermined value by the molecular design of the resin, thereby improving the workability of the insulating film and suppressing the occurrence of damage or the like during winding.
In addition, in (2) Japanese Patent Laid-Open No. 62-58519, in order to improve the density of the winding, the conductor after coating and forming the insulating film in advance is formed into a rectangular shape by rolling to form a rectangular winding. In manufacturing, in order to prevent processing deterioration of the insulating film due to rolling and heat treatment and reduction in thermal shock resistance, as an insulating coating (varnish) for forming the insulating film, polyetherimide, polyesterimide, and phenolic compound It is described that a polyisocyanate block body clogged with is added.
[0005]
Further, (3) Japanese Patent Application Laid-Open No. 58-34828 discloses that by blending polyamideimide and polyetherimide, it has mechanical properties equivalent to those of polyetherimide, and also has solvent resistance, abrasion resistance, long-term performance. It has been shown to obtain materials with excellent heat resistance.
[0006]
[Problems to be solved by the invention]
However, in the technique (1) among the above, although the insulating film is formed in consideration of the above (a), (c), and (d), the flexibility of (b) is not always sufficient.
In the technique (2), the flexibility of the polyetherimide, the heat resistance of the polyesterimide and the adhesion to the conductor, and the brazing property of the polyisocyanate block body blocked with a phenolic compound are combined. As described above, it solves the problem of deterioration of processing and thermal shock resistance of the insulation film when rolled to a flat angle, but the elongation at break of the polyesterimide is not sufficient, so the flexibility of the film is still Not enough.
[0007]
Furthermore, since the blend materials obtained in (3) are low in glass transition temperature, as shown in Table II of the same publication, for example, as a coating material for windings requiring high heat resistance, Is insufficient.
As described above, each of the prior arts (1) to (3) is considered to solve a predetermined problem at each technical level, but it has a higher heat resistance while maintaining high heat resistance. In order to obtain workability, that is, resistance to rolling and winding, it cannot be said to have sufficient characteristics.
[0008]
This is because all of the above prior arts basically have a single-layer structure, and various kinds of materials are combined to give the insulating film a plurality of different characteristics. This is probably because of this.
Therefore, the inventors have a laminated structure of the insulating film, and the insulation structure having excellent characteristics that cannot be obtained in the single-layer structure by giving different characteristics to each layer by changing the resin composition in each layer. We studied the production of electric wires.
[0009]
First, a first insulating layer made of a resin having a glass transition temperature of 250 ° C. or higher, and a second insulating layer in which a thermoplastic resin having a glass transition temperature of 140 ° C. or higher is blended with polyamideimide on the conductor. In order to form an insulating film having a laminated structure by sequentially laminating and covering, it was found that an insulated wire having better work resistance than before can be obtained while maintaining high heat resistance. For example, in the process of joining the ends of insulated wires by welding or the like during coil processing, a new problem that the insulation film near the joint is foamed by the heat of joining or the discoloration length becomes longer and hinders joining It became clear that
[0010]
The object of the present invention is to provide excellent process resistance that does not cause damage to the film even when severe rolling and winding processes are performed, and has high heat resistance equivalent to that of polyamide-imide, and also an insulated wire terminal. To provide a new insulated wire that has excellent bondability because the insulating film near the joint does not foam due to the heat of joining, or the discoloration length becomes long. It is aimed.
[0011]
[Means for Solving the Problems and Effects of the Invention]
In order to solve the above problems, the insulated wire of the present invention is
(1) Po A first insulating layer comprising at least one of lyamideimide and polyimide;
(2) Polyamideimide A with a glass transition temperature of 140 ° C or higher Polyetherimide A second insulating layer formed by blending B in a ratio of A / B = 70/30 to 30/70, expressed as a weight ratio A / B;
Are coated and laminated in this order to form a film thickness T of the first insulating layer on the conductor. 1 And the thickness T of the second insulating layer 2 Ratio T 1 / T 2 Is T 1 / T 2 = In the range of 5/95 to 40/60, and Derived from the varnish that is the basis of the first insulating layer and the second insulating layer An insulating film having a residual solvent amount of 0.05% by weight or less of the total amount of the insulating film is formed.
[0012]
The reason why the above-described problems can be solved by the present invention is as follows.
1) Po It consists of at least one of lyamideimide and polyimide, and on top of the first insulating layer that has excellent heat resistance and adhesion to the conductor, it contains polyamideimide, so that it has excellent adhesion to the first insulating layer. In the ratio of A / B = 70/30 to 30/70 in terms of weight ratio A / B with respect to the polyamideimide A Polyetherimide By laminating the second insulating layer excellent in flexibility because it contains B, the insulating film has good adhesion to the conductor and high flexibility, resulting in severe rolling and winding. High workability that can withstand wire processing can be imparted.
2) As above, in the second insulating layer Polyetherimide Prescribing the amount of Polyetherimide And the glass transition temperature of the first and second insulating layers is set to 140 ° C. or higher. 1 , T 2 Ratio T 1 / T 2 By keeping the range of 5/95 to 40/60, the heat resistance of the entire insulating film can be maintained at a high level equivalent to that of polyamideimide while maintaining the high flexibility described above.
[0013]
In addition, heat resistance is evaluated by the heat softening temperature measured by the method mentioned later, and it is preferable that it is 400 degreeC or more in this invention.
3) As described above, the laminated structure of the first and second insulating layers ensures good adhesion to the conductor, and in the second insulating layer Polyetherimide Prescribing the amount of Polyetherimide The glass transition temperature of the film and the ratio of the film thicknesses of the first and second insulating layers are defined to maintain the heat resistance of the entire insulating film at the level of polyamideimide, Derived from the varnish that is the basis of the first insulating layer and the second insulating layer By setting the residual solvent amount of the entire insulating film to 0.05% by weight or less of the total amount of the insulating film, the insulating film in the vicinity of the joint is foamed by the heat of bonding, etc. Or it can prevent the discoloration length becoming long more reliably than before, and the joining property can be improved. That is, in order to improve the bondability of the insulating film, it is necessary to control the amount of residual solvent that causes foaming, and to improve the heat resistance of the insulating film itself and the adhesion to the conductor.
[0014]
In the present specification, the residual solvent amount is represented by a value measured by gas chromatography based on an evaluation method described later.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described below. The insulated wire of the present invention is as described above.
(1) Po A first insulating layer comprising at least one of lyamideimide and polyimide;
(2) Polyamideimide with a glass transition temperature of 140 ° C or higher Polyetherimide A second insulating layer containing
Are coated and laminated in this order to form an insulating film having a laminated structure on the conductor.
[0016]
Of these, the first insulating layer (1) is as described above. To The first insulating layer contains polyamideimide and / or polyimide as a resin component but does not contain a thermoplastic resin unlike the second insulating layer because it is composed of at least one of riamideimide and polyimide. Means that. However, this description does not prevent the first insulating layer from containing various additives described later such as a colorant.
[0017]
The said 1st insulating layer is formed by application | coating and baking of the varnish for 1st insulating layers containing the polyamideimide and / or a polyimide as a resin component similarly to the insulating film of the conventional single layer structure.
Among the varnishes for the first insulating layer, those containing polyamideimide as a resin component,
(A) polymerizing a diisocyanate component and an acid component;
(B) The reaction product obtained by reacting the diamine component and the acid component is further polymerized with an approximately equimolar amount of the diisocyanate component,
(C) polymerizing an acid component containing an acid chloride and a diamine component;
It manufactures by the conventionally well-known manufacturing methods, such as.
[0018]
Moreover, the varnish for the first insulating layer containing polyimide as the resin component is
(D) polymerizing a diamine component and an acid anhydride component;
This is also manufactured by a conventionally known manufacturing method.
Furthermore, a varnish containing both polyamideimide and polyimide as a resin component is produced by blending both of the above.
Of the varnishes for the first insulating layer, preferred examples of the polyamideimide varnish include, but are not limited to, for example, diphenylmethane diisocyanate as the diisocyanate component and trimellitic anhydride as the acid component. (Specific examples include trade names HI-400, HI-405, and HI-406 manufactured by Hitachi Chemical Co., Ltd.).
[0019]
A preferred example of a polyimide-based varnish is, but not limited to, for example, one produced using diaminodiphenyl ether as a diamine component and pyromellitic acid anhydride as an acid anhydride component [specific Examples include the trade name PyreML manufactured by IST, the trade name Toray Nice manufactured by Toray DuPont, and the like.
As described above, the second insulating layer laminated and coated on the first insulating layer has a glass transition temperature of 140 ° C. or higher on the polyamideimide A. Polyetherimide B is expressed by a weight ratio A / B and is blended at a ratio of A / B = 70/30 to 30/70.
[0020]
Examples of the polyamideimide that forms the second insulating layer include the same polyamide imide used in the first insulating layer.
Also blended with the polyamideimide Polyetherimide Has a glass transition temperature of 140 ° C. or higher. There is a need. Also, Those having a particularly high elongation rate are preferred.
[0021]
Glass transition temperature of 140 ° C or higher Polyether immi Do , the above When combined with polyamide-imide, it is possible to form a second insulating layer that is excellent in heat resistance and particularly in processing resistance when rolled to be used as a rectangular winding, and is advantageous in terms of cost. Ru .
In the second insulating layer, to the polyamideimide Polyetherimide The reason why the blending ratio is limited to the above range is as follows.
[0022]
Ie Polyetherimide If the blending ratio is less than the above range, the flexibility of the second insulating layer is lowered, so that the flexibility of the entire insulating film is also lowered. For this reason, the workability of the insulation film is lowered, and it becomes easy to cause damage when severe rolling and winding processes are performed, resulting in problems such as deterioration in electrical characteristics of the device and reduction in production yield. Cause.
on the other hand, Polyetherimide If the blending ratio exceeds the above range, the heat resistance of the insulating film as a whole is lowered and the heat resistance standard such as the thermal softening temperature of 400 ° C. or higher cannot be satisfied. The electric wire cannot be used for windings that require high heat resistance. Moreover, in the process of joining the terminal of an insulated wire, the discoloration length of the insulation film near a junction part becomes long with the heat | fever of joining, etc., and the problem that the bondability of an insulated wire falls also arises.
[0023]
In consideration of imparting high workability, heat resistance and good bondability to the insulating film, the polyamide imide A in the second insulating layer is added. Polyetherimide The blending ratio of B is preferably about A / B = 65/35 to 45/55 in the above-mentioned range, particularly expressed as a weight ratio A / B, and A / B = about 65/35 to 55/45. More preferably.
The second insulating layer is formed in the same manner as the first insulating layer. That is, as a resin component, a predetermined amount of polyamide imide Polyetherimide The second insulating layer is formed by applying and baking the varnish for the second insulating layer blended with the first insulating layer on the first insulating layer.
[0024]
As the varnish for the second insulating layer, for example,
(D) Mix a solution in which each resin is separately dissolved in a solvent,
(E) Each resin is simultaneously dissolved and mixed in the same solvent,
(F) After one resin is dissolved in a solvent, the other resin is added and dissolved and mixed.
(G) After one resin is dissolved, the other resin is synthesized in the solution.
Any of those manufactured by various methods can be used.
[0025]
The film thickness of the first and second insulating layers and the total film thickness of the insulating film, which is the sum of both layers, are set to appropriate values according to the use, shape, dimensions, etc. of the insulated wires, respectively. be able to.
However, in the present invention, the film thickness T of the first and second insulating layers. 1 , T 2 Ratio T 1 / T 2 However, it is limited to the range of 5/95 to 40/60 as described above. The reason is as follows.
[0026]
That is, when the proportion of the first insulating layer is larger than the above range, the flexibility of the insulating film as a whole is lowered, so that the workability is also lowered, and severe rolling and winding processes are performed. When it is performed, damage or the like is likely to occur, which causes problems such as deterioration in electrical characteristics of devices and reduction in production yield.
On the other hand, when the proportion of the second insulating layer is larger than the above range, the heat resistance of the insulating film as a whole is lowered and satisfies the heat resistance standard such as the thermal softening temperature of 400 ° C. or higher. Therefore, there is a problem that the insulated wire cannot be used for applications such as windings that require high heat resistance. In addition, since the heat resistance of the insulating film is reduced as described above, and the effect of ensuring the adhesion of the insulating film to the conductor by the first insulating layer is insufficient, the step of joining the ends of the insulated wires Therefore, the discoloration length of the insulating film near the joint portion is increased due to the heat of the joint, and the problem arises that the bondability of the insulated wire is lowered.
[0027]
In consideration of imparting high workability, heat resistance, adhesion to the conductor and good bondability to the insulating film, the film thickness T of the first and second insulating layers 1 , T 2 Ratio T 1 / T 2 Within the above range, is preferably about 5/95 to 25/75, more preferably about 10/90 to 20/80.
As described above, the thicknesses of the first and second insulating layers are not particularly limited, but are preferably about 0.001 to 0.100 mm, respectively.
[0028]
Each of the first and second insulating layers may have a single-layer structure or a composition (for example, in the case of the first insulating layer, the type of polyamideimide or polyimide used, the amount of additives, etc.) In the case of two insulating layers, Polyetherimide And a laminated structure of two or more layers having different types, the mixing ratio of the two, the amount of the additive, and the like.
For example, when the first insulating layer has a laminated structure, the thickness of each layer constituting the first insulating layer so that the total film thickness and the second insulating layer are within the above range. Can be adjusted. Similarly, when the second insulating layer has a laminated structure, the second insulating layer is configured so that the total film thickness and the film thickness of the first insulating layer are within the above range. What is necessary is just to adjust the thickness of each layer.
[0029]
For the first and second insulating layers, as described above, various additives such as colorants such as pigments and dyes, inorganic or organic fillers, lubricants, and the like do not impair the characteristics of the respective layers. It can also be contained.
The insulating film composed of the first and second insulating layers may have a primer layer between the conductor and the first insulating layer, or on the second insulating layer, that is, on the outermost layer of the insulating film. You may have a surface lubricating layer.
[0030]
Such a surface lubricating layer is formed by, for example, applying liquid paraffin, solid paraffin, or the like, or directly forming a lubricant such as various waxes, polyethylene, fluororesin, or silicone resin on the second insulating layer. It forms by forming into a film in the state bound by the binder resin which has this.
Insulation film Derived from the varnish that is the basis of the first insulating layer and the second insulating layer The residual solvent amount needs to be 0.05% by weight or less of the total amount of the insulating film.
[0031]
When the residual solvent amount exceeds this range, as described above, even if the insulating film has both good adhesion to the conductor and high heat resistance, the bonding process is performed in the step of bonding the end of the insulated wire. The insulating film near the portion is easily foamed by the heat of bonding and the like, causing a problem that the bondability of the insulated wire is lowered.
The residual solvent amount of the insulating film is preferably 0.01% by weight or less even within the above range, and the smaller the amount, the more preferable. In particular, it is ideal that the amount of residual solvent is as close to 0% as possible, but if it is within the above range, it is possible to produce an insulated wire having good bondability in which the insulating film does not foam. it can.
[0032]
In order to adjust the residual solvent amount of the insulating film to the above range, the insulated wire coated and formed with the insulating film may be heat-treated in an inert gas atmosphere such as nitrogen.
The conditions for the heat treatment are not particularly limited, but the heat treatment is preferably performed at a temperature of 220 ° C. or more for 5 hours or more. If the temperature of the heat treatment is lower than this or the time is shorter than this, the heat treatment is insufficient, and the residual solvent amount of the insulating film cannot be suppressed to 0.01% by weight or less of the total amount of the insulating film. In the process of joining the ends of the electric wires, the insulating film in the vicinity of the joining portion is likely to be foamed by the heat of the joining and the like, and there is a possibility that the joining property of the insulated wires is lowered.
[0033]
The insulating film preferably has an elongation at break of 50% or more in consideration of its flexibility.
As a conductor for covering and forming an insulating film, various conductors made of copper, aluminum, etc., which are usually used for insulated wires, can be used. Especially, low oxygen copper having an oxygen content of 10 ppm or less. (Including oxygen-free copper) The conductor formed in is preferably used.
[0034]
When such a low oxygen copper conductor is used, the amount of gas (oxygen) generated from the conductor is significantly reduced when the conductor is heated by the heat of joining in the step of joining the ends of the insulated wires. As a result, there is an advantage that foaming of the insulating film on the conductor is further suppressed, and the bondability of the insulated wire is further improved.
The insulated wire of the present invention can be formed in various conventionally known shapes such as a round wire depending on the application, etc., but in particular, as described above, in order to improve the density of the winding, an insulating film is coated, The formed conductor (usually a round wire) is preferably formed into a rectangular shape by rolling to form a rectangular winding.
[0035]
At this time, according to the configuration of the present invention, since the insulating film has excellent adhesion and flexibility to the conductor and resistance to the rolling process caused thereby, the damage is caused by the rolling process. In addition, after rolling, it can withstand the same flexibility test as a round wire, maintains excellent flexibility and good adhesion to the conductor, and also has resistance to winding processing. Because it excels, it will not be damaged during the winding process. Therefore, according to the present invention, it is possible to obtain a good rectangular winding that does not cause problems such as a decrease in electrical characteristics of a device and a decrease in production yield.
[0036]
As a specific method of the rolling process, the conductor (round line) after coating and forming the insulating film as described above is literally rolled by, for example, a rolling roller, or drawn through a cassette roller die and rolled. And the like.
[0037]
【Example】
Hereinafter, the present invention will be described based on examples and comparative examples.
Example 1
First, a polyamide-imide varnish as a varnish for the first insulating layer (made by Hitachi Chemical Co., Ltd.) is formed on a round wire conductor having a diameter of 2 mm and formed of low-oxygen copper having an oxygen content of 3 ppm. The product name HI-400] is applied and baked in a conventional manner, and the film thickness T 1 A first insulating layer of 0.01 mm was coated and formed.
[0038]
Next, 240 parts by weight of the same polyamide imide varnish [trade name HI-400 manufactured by Hitachi Chemical Co., Ltd., resin content 25% by weight] The 40 parts by weight of polyetherimide (trade name Ultem 1000, glass transition temperature 220 ° C., manufactured by Nippon GE Plastics Co., Ltd.) and N-methyl so that the total resin content is 20% by weight Varnish for the second insulating layer prepared by diluting with -2-pyrrolidone [polyamideimide A contained in the varnish and The Rear ether De B The blending ratio (weight ratio) A / B = 60/40] is applied and baked on the first insulating layer by a conventional method, and the film thickness T 2 = 0.04 mm of a second insulating layer was coated and laminated to form a two-layered insulating film. Ratio T of the thickness of both insulating layers 1 / T 2 = 20/80. The finished diameter at this time was 2.1 mm.
[0039]
Next, by covering the insulating film as described above and drawing the formed conductor through a cassette roller die, after rolling from the vertical direction and the horizontal direction, it was heat-treated at 240 ° C. for 6 hours in nitrogen, A rectangular winding as an insulated wire was manufactured.
Examples 2 to 7, Comparative Examples 1 and 2
Polyamideimide A in the varnish for the second insulating layer And Rear ether De B The blending ratio (weight ratio) A / B is 85/15 (Comparative Example 1), 70/30 (Example 2), 65/35 (Example 3), 55/45 (Example 4), 50 / 50 (Example 5), 40/60 (Example 6), 30/70 (Example 7), or 15/85 (Comparative Example 2), the amount of the polyetherimide to the polyamideimide varnish is adjusted. A rectangular winding as an insulated wire was manufactured in the same manner as in Example 1 except that the adjustment was made.
[0040]
Example 8, Comparative Example 3
A rectangular winding as an insulated wire was manufactured in the same manner as in Example 1 except that the heat treatment conditions were 200 ° C. for 6 hours (Comparative Example 3) or 220 ° C. for 6 hours (Example 8).
Example 9
A rectangular winding as an insulated wire was manufactured in the same manner as in Example 1 except that a round wire having a diameter of 2 mmφ formed of tough pitch copper having an oxygen content of 200 ppm was used as the conductor.
[0041]
Comparative Example 4
Except that the above-mentioned polyamideimide varnish was applied and baked in the usual manner on the same conductor used in Example 1, and an insulating film having a thickness of 0.05 mm was coated and formed. In the same manner as in Example 1, a rectangular winding as an insulated wire was manufactured.
Comparative Example 5
On the same conductor as that used in Example 1, the varnish for the second insulating layer prepared in Example 1 was applied and baked in the usual manner to form an insulating film having a thickness of 0.05 mm. A rectangular winding as an insulated wire was manufactured in the same manner as in Example 1 except that it was covered and formed.
[0042]
Example 10
Film thickness T of the first insulating layer 1 = 0.005 mm, film thickness T of the second insulating layer 2 = 0.045 mm, ratio T of the thickness of both insulating layers 1 / T 2 = 10/90 A rectangular winding as an insulated wire was manufactured in the same manner as in Example 1 except that it was set to 10/90.
Example 11
Film thickness T of the first insulating layer 1 = 0.015 mm, film thickness T of the second insulating layer 2 = 0.035 mm, ratio T of the thickness of both insulating layers 1 / T 2 = 30/70 Except having set it as 30/70, it carried out similarly to Example 1, and manufactured the rectangular winding as an insulated wire.
[0043]
Comparative Example 6
Film thickness T of the first insulating layer 1 = 0.025 mm, film thickness T of the second insulating layer 2 = 0.025 mm, ratio T of the thickness of both insulating layers 1 / T 2 A rectangular winding as an insulated wire was manufactured in the same manner as in Example 1 except that 50/50.
Example 12
On the same conductor as used in Example 1, a polyimide varnish as a varnish for the first insulating layer (the above-mentioned product name PyreML manufactured by IST) was applied and baked by a conventional method to obtain a film thickness. T 1 = A rectangular winding as an insulated wire was manufactured in the same manner as in Example 1 except that the first insulating layer of 0.01 mm was coated and formed.
[0044]
About the insulated wire (flat coil | winding) produced by each said Example and the comparative example, the following test was respectively performed and the characteristic was evaluated.
Measurement of residual solvent
After the insulated wire is placed in a heating furnace with a furnace temperature of 350 ° C. and left for 3 minutes, the gas generated in the furnace is sampled, and the amount of solvent is quantified by gas chromatography (manufactured by GL Sciences). The ratio to the total amount of the insulating film was calculated to obtain the residual solvent amount (% by weight).
[0045]
Tensile test
The breaking elongation (%) was determined when a tensile test was performed on the insulating film remaining after the conductor was etched away from the insulated wire using a tensile tester under the conditions of a gauge length of 20 mm and a tensile speed of 10 mm / min.
Bondability test
An insulated wire having a length of 150 mm was sampled, and the coatings were peeled off from both ends by 5 mm each. Then, one end was grounded and a welding torch was placed at the tip of the other end with an interval of 2 mm, and arc discharge was performed at 120 A for 0.2 seconds to melt the end of the insulated wire. The bondability was evaluated based on the discoloration length (mm) of the insulating film in the vicinity of the dissolved portion and the presence or absence of foaming of the insulating film. In the test, approximately 15 liters of Ar gas was allowed to flow through the dissolving portion per minute.
[0046]
General characteristic test
According to Japanese Industrial Standard JIS C 3003 “Test method for enameled copper wire and enameled aluminum wire”, etch width 2 mm, flat width 2 mm, thermal softening temperature (° C.), and dielectric breakdown voltage (kV) were measured. The evaluation criteria for etch width 2 mm and flat width 2 mm were as follows.
○: No cracking in insulating film (good flexibility)
Δ: Partially cracked (flexibility is somewhat poor)
×: Cracking (poor flexibility)
The results are shown in Tables 1 and 2.
[0047]
[Table 1]
[Table 2]
From both tables, Comparative Example 4 in which a single-layer insulating film was formed with a polyamideimide varnish had poor flexibility, and Comparative Example 5 in which a single-layered insulating film was formed with a varnish for the second insulating layer was heat resistant. It was found that the sex was insufficient.
Moreover, even if it has an insulating film having a two-layer structure consisting of the first and second insulating layers, the second insulating layer Polyetherimide In Comparative Example 1 in which the blending ratio was less than the range specified in the present invention, the flexibility decreased, conversely Polyetherimide It was found that Comparative Example 2 in which the blending ratio exceeded the range specified in the present invention was reduced in flexibility and heat resistance.
[0050]
Further, from Comparative Example 3 in which the residual solvent amount of the insulating film exceeded 0.05% by weight and Example 8 in which the residual solvent amount was 0.05% by weight or less, the bondability decreases as the residual solvent amount increases. understood.
Furthermore, the comparative example 6 in which the film thickness ratio of the first and second insulating layers deviates from the one in which the film thickness of the first insulating layer is larger than the range defined in the present invention is reduced in flexibility and bondability. It has been found.
[0051]
On the other hand, it has an insulating film having a two-layer structure composed of first and second insulating layers, of which the second insulating layer Polyetherimide The blending ratio of B is expressed in terms of a weight ratio A / B with respect to polyamideimide A and is within the range of A / B = 70/30 to 30/70, and the film thickness of the first and second insulating layers is Ratio T 1 / T 2 = In the range of 5/95 to 40/60 and the amount of residual solvent is 0.01% by weight or less of the total amount of the insulating film, all of Examples 1 to 12 are used for rolling to form a rectangular winding. In addition to excellent workability, it was confirmed that the post-processing flexibility, heat resistance, and bondability were also good.
[0052]
Further, when each example is compared, the weight ratio is within the range of A / B = 65/35 to 55/45, which is particularly preferable in terms of bonding properties, and the oxygen concentration of the conductor is 10 ppm or less. It was also found that this is preferable in terms of bondability.
Claims (7)
(2) ポリアミドイミドＡに、ガラス転移温度１４０℃以上のポリエーテルイミドＢを、重量比Ａ／Ｂで表してＡ／Ｂ＝７０／３０〜３０／７０の割合で配合してなる第２絶縁層と
をこの順に被覆、積層することによって、導体上に、上記第１絶縁層の膜厚Ｔ1と、第２絶縁層の膜厚Ｔ2との比Ｔ1／Ｔ2がＴ1／Ｔ2＝５／９５〜４０／６０の範囲内で、かつ上記第１絶縁層および第２絶縁層のもとになるワニスに由来する残留溶剤量が絶縁皮膜総量の０．０５重量％以下である絶縁皮膜を形成したことを特徴とする絶縁電線。(1) and the port Riamidoimido, and a first insulating layer made of at least one of polyimide,
(2) Second insulation formed by blending polyamideimide A with polyetherimide B having a glass transition temperature of 140 ° C. or higher in a weight ratio of A / B at a ratio of A / B = 70/30 to 30/70 By coating and laminating the layers in this order, the ratio T 1 / T 2 between the film thickness T 1 of the first insulating layer and the film thickness T 2 of the second insulating layer is T 1 / T on the conductor. 2 = 5/95 to 40/60, and the residual solvent amount derived from the varnish that is the basis of the first insulating layer and the second insulating layer is 0.05% by weight or less of the total amount of the insulating film. An insulated wire characterized by forming an insulating film.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33953699A JP4245244B2 (en) | 1999-11-30 | 1999-11-30 | Insulated wire |
| US09/460,647 US6288342B1 (en) | 1998-12-15 | 1999-12-14 | Insulated wire |
| EP99310124A EP1011107B1 (en) | 1998-12-15 | 1999-12-15 | Insulated wire |
| DE69920381T DE69920381T2 (en) | 1998-12-15 | 1999-12-15 | Insulated wire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33953699A JP4245244B2 (en) | 1999-11-30 | 1999-11-30 | Insulated wire |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001155551A JP2001155551A (en) | 2001-06-08 |
| JP4245244B2 true JP4245244B2 (en) | 2009-03-25 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33953699A Expired - Fee Related JP4245244B2 (en) | 1998-12-15 | 1999-11-30 | Insulated wire |
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| JP (1) | JP4245244B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015105095A1 (en) | 2014-01-10 | 2015-07-16 | 古河電気工業株式会社 | Insulated electric wire, coil and electric/electronic device, and cracking prevention method for insulated electric wire |
| CN107248431A (en) * | 2017-05-09 | 2017-10-13 | 佳腾电业（赣州）有限公司 | A kind of production technology of the flat enamel covered wire of high tenacity |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4057230B2 (en) * | 2000-10-03 | 2008-03-05 | 古河電気工業株式会社 | Insulated conductor |
| JP5364939B2 (en) * | 2008-01-09 | 2013-12-11 | 住友電工ウインテック株式会社 | Insulated wire |
| US8679628B2 (en) | 2009-06-18 | 2014-03-25 | Hitachi Cable, Ltd. | Insulated wire |
| JP2011003375A (en) * | 2009-06-18 | 2011-01-06 | Hitachi Cable Ltd | Insulated wire |
| JP5407059B2 (en) * | 2010-01-26 | 2014-02-05 | 日立金属株式会社 | Insulated wire |
| EP2555204B1 (en) | 2010-10-01 | 2018-02-14 | Furukawa Electric Co., Ltd. | Insulated wire |
| JP5568028B2 (en) * | 2011-01-26 | 2014-08-06 | トヨタ自動車株式会社 | Insulated conducting wire, coil and method for producing insulated conducting wire |
| JPWO2022224486A1 (en) * | 2021-04-23 | 2022-10-27 |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5347507B2 (en) * | 1971-08-27 | 1978-12-21 | ||
| JPS5128418B2 (en) * | 1973-01-26 | 1976-08-19 | ||
| JP2991550B2 (en) * | 1991-10-31 | 1999-12-20 | 株式会社東芝 | Insulation method for rotating electric machine winding |
| JPH05174632A (en) * | 1991-12-19 | 1993-07-13 | Sumitomo Electric Ind Ltd | Coil |
| JPH05190027A (en) * | 1992-01-10 | 1993-07-30 | Furukawa Electric Co Ltd:The | Heat-resistant insulated wire |
| JPH05258614A (en) * | 1992-03-11 | 1993-10-08 | Hitachi Cable Ltd | Flat square enamel wire |
| JPH05274921A (en) * | 1992-03-24 | 1993-10-22 | Furukawa Electric Co Ltd:The | Insulated wire |
| JP2912196B2 (en) * | 1994-12-12 | 1999-06-28 | 第一電工株式会社 | Insulated wire for soldering |
| JP3413069B2 (en) * | 1997-08-07 | 2003-06-03 | 東京特殊電線株式会社 | Low odor self-fusing magnet wire |
| JP2000235818A (en) * | 1998-12-15 | 2000-08-29 | Sumitomo Electric Ind Ltd | Insulated wire |
-
1999
- 1999-11-30 JP JP33953699A patent/JP4245244B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015105095A1 (en) | 2014-01-10 | 2015-07-16 | 古河電気工業株式会社 | Insulated electric wire, coil and electric/electronic device, and cracking prevention method for insulated electric wire |
| KR20160106638A (en) | 2014-01-10 | 2016-09-12 | 후루카와 덴키 고교 가부시키가이샤 | Insulated electric wire, coil and electric/electronic device, and cracking prevention method for insulated electric wire |
| CN107248431A (en) * | 2017-05-09 | 2017-10-13 | 佳腾电业（赣州）有限公司 | A kind of production technology of the flat enamel covered wire of high tenacity |
| CN107248431B (en) * | 2017-05-09 | 2019-01-25 | 佳腾电业（赣州）有限公司 | A kind of production technology of the flat enamel covered wire of high tenacity |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2001155551A (en) | 2001-06-08 |
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