JP4724900B2 - Flame retardant polyamide resin composition and molded article thereof - Google Patents

Description

【００７４】
（ただし式中のＲ₁ は
【００７５】
【化２】

【００７６】
の（ａ）〜（ｊ）から選ばれた一種以上の基を示し、Ｒ₂ は
【００７７】
【化３】

【００７８】
の（Ａ）〜（Ｆ）から選ばれた一種以上の基を示す。また、式中Ｘは水素原子または塩素原子を示す。）
なお、構造単位(II)および(III) の合計と構造単位(IV)は実質的に等モルであることが望ましい。
【００７９】
上記構造単位(I) はｐ−ヒドロキシ安息香酸から生成した構造単位であり、構造単位(II)は４，４´−ジヒドロキシビフェニル、３，３´，５，５´−テトラメチル−４，４´−ジヒドロキシビフェニル、ハイドロキノン、ｔ−ブチルハイドロキノン、フェニルハイドロキノン、メチルハイドロキノン、２，６−ジヒドロキシナフタレン、２，７−ジヒドロキシナフタレン、２，２−ビス（４−ヒドロキシフェニル）プロパンおよび４，４´−ジヒドロキシジフェニルエーテルから選ばれた一種以上の芳香族ジヒドロキシ化合物から生成した構造単位を、構造単位(III) はエチレングリコールから生成した構造単位を、構造単位(IV)はテレフタル酸、イソフタル酸、４，４´−ジフェニルジカルボン酸、２，６−ナフタレンジカルボン酸、１，２−ビス（フェノキシ）エタン−４，４´−ジカルボン酸、１，２−ビス（２−クロルフェノキシ）エタン−４，４´−ジカルボン酸および４，４’−ジフェニルエーテルジカルボン酸から選ばれた一種以上の芳香族ジカルボン酸から生成した構造単位を各々示す。これらのうちＲ₁が
【００８０】
【化４】

【００８１】
であり、Ｒ₂が
【００８２】
【化５】

【００８３】
であるものが特に好ましい。
【００８４】
上記構造単位(I)、(II)、(III)および(IV)の共重合量は任意である。しかし、本発明の特性を発揮させるためには次の共重合量であることが好ましい。
【００８５】
すなわち、上記構造単位(I)、(II)、(III)、(IV)からなる共重合体の場合は、上記構造単位(I)および(II)の合計は構造単位(I)、(II)および(III)の合計に対して３０〜９５モル％が好ましく、４０〜９３モル％がより好ましい。また、構造単位(III)は構造単位(I)、(II)および(III)の合計に対して７０〜５モル％が好ましく、６０〜７モル％がより好ましい。また、構造単位(I)と(II)のモル比［(I)／(II)］は好ましくは７５／２５〜９５／５であり、より好ましくは７８／２２〜９３／７である。また、構造単位(IV)は構造単位(II)および(III)の合計と実質的に等モルであることが好ましい。
【００８６】
一方、上記構造単位(II) を含まない場合は流動性の点から上記構造単位(I)は構造単位(I)および（III）の合計に対して４０〜９０モル％であることが好ましく、６０〜８８モル％であることが特に好ましく、構造単位（IV）は構造単位（III）と実質的に等モルであることが好ましい。
【００８７】
また液晶性ポリエステルアミドとしては、上記構造単位(I)〜(IV)以外にｐ−アミノフェノールから生成したｐ−イミノフェノキシ単位を含有した異方性溶融相を形成するポリエステルアミドが好ましい。
【００８８】
なお、上記好ましく用いることができる液晶性ポリエステル、液晶性ポリエステルアミドは、上記構造単位(I)〜(IV)を構成する成分以外に３，３’−ジフェニルジカルボン酸、２，２’−ジフェニルジカルボン酸などの芳香族ジカルボン酸、アジピン酸、アゼライン酸、セバシン酸、ドデカンジオン酸などの脂肪族ジカルボン酸、ヘキサヒドロテレフタル酸などの脂環式ジカルボン酸、クロルハイドロキノン、３，４’−ジヒドロキシビフェニル、４，４’−ジヒドロキシジフェニルスルホン、４，４’−ジヒドロキシジフェニルスルフィド、４，４’−ジヒドロキシベンゾフェノン、３，４’−ジヒドロキシビフェニルなどの芳香族ジオール、プロピレングリコール、１，４−ブタンジオール、１，６−ヘキサンジオール、ネオペンチルグリコール、１，４−シクロヘキサンジオール、１，４−シクロヘキサンジメタノールなどの脂肪族、脂環式ジオールおよびｍ−ヒドロキシ安息香酸、２，６−ヒドロキシナフトエ酸などの芳香族ヒドロキシカルボン酸およびｐ−アミノ安息香酸などを液晶性を損なわない程度の範囲でさらに共重合せしめることができる。
【００８９】
本発明で使用する液晶性樹脂は、ペンタフルオロフェノール中で対数粘度を測定することが可能である。その際、０．１ｇ／ｄｌの濃度で６０℃で測定した値で０．５〜１５．０ｄｌ／ｇが好ましく、１．０〜３．０ｄｌ／ｇが特に好ましい。
【００９０】
また、本発明における液晶性樹脂の溶融粘度は０．５〜５００Ｐａ・ｓが好ましく、特に１〜２５０Ｐａ・ｓがより好ましい。また、流動性により優れた組成物を得ようとする場合には、溶融粘度を５０Ｐａ・ｓ以下とすることが好ましい。
【００９１】
なお、この溶融粘度は融点（Ｔｍ）＋１０℃の条件で、ずり速度１，０００（１／秒）の条件下で高化式フローテスターによって測定した値である。
【００９２】
ここで、融点（Ｔｍ）とは示差熱量測定において、重合を完了したポリマを室温から２０℃／分の昇温条件で測定した際に観測される吸熱ピーク温度（Ｔｍ1 ）の観測後、Ｔｍ1 ＋２０℃の温度で５分間保持した後、２０℃／分の降温条件で室温まで一旦冷却した後、再度２０℃／分の昇温条件で測定した際に観測される吸熱ピーク温度（Ｔｍ2 ）を指す。
【００９３】
液晶性樹脂の融点は、特に限定されないが、ポリアミド樹脂への分散性の点から好ましくは３４０℃以下、より好ましくは３３０℃以下である。
【００９４】
本発明において使用する上記液晶性ポリエステルの製造方法は、特に制限がなく、公知のポリエステルの重縮合法に準じて製造できる。
【００９５】
例えば、上記液晶ポリエステルの製造において、次の製造方法が好ましく挙げられる。
（１）ｐ−アセトキシ安息香酸および４，４’−ジアセトキシビフェニル、ジアセトキシベンゼンなどの芳香族ジヒドロキシ化合物のジアシル化物と２，６−ナフタレンジカルボン酸、テレフタル酸、イソフタル酸などの芳香族ジカルボン酸から脱酢酸縮重合反応によって製造する方法。
（２）ｐ−ヒドロキシ安息香酸および４，４’−ジヒドロキシビフェニル、ハイドロキノンなどの芳香族ジヒドロキシ化合物と２，６−ナフタレンジカルボン酸、テレフタル酸、イソフタル酸などの芳香族ジカルボン酸に無水酢酸を反応させて、フェノール性水酸基をアシル化した後、脱酢酸重縮合反応によって製造する方法。
（３）ｐ−ヒドロキシ安息香酸のフェニルエステルおよび４，４’−ジヒドロキシビフェニル、ハイドロキノンなどの芳香族ジヒドロキシ化合物と２，６−ナフタレンジカルボン酸、テレフタル酸、イソフタル酸などの芳香族ジカルボン酸のジフェニルエステルから脱フェノール重縮合反応により製造する方法。
（４）ｐ−ヒドロキシ安息香酸および２，６−ナフタレンジカルボン酸、テレフタル酸、イソフタル酸などの芳香族ジカルボン酸に所定量のジフェニルカーボネートを反応させて、それぞれジフェニルエステルとした後、４，４’−ジヒドロキシビフェニル、ハイドロキノンなどの芳香族ジヒドロキシ化合物を加え、脱フェノール重縮合反応により製造する方法。
（５）ポリエチレンテレフタレートなどのポリエステルのポリマー、オリゴマーまたはビス（β−ヒドロキシエチル）テレフタレートなど芳香族ジカルボン酸のビス（β−ヒドロキシエチル）エステルの存在下で（１）または（２）の方法により製造する方法。
【００９６】
液晶性ポリエステルの重縮合反応は無触媒でも進行するが、酢酸第一錫、テトラブチルチタネート、酢酸カリウムおよび酢酸ナトリウム、三酸化アンチモン、金属マグネシウムなどの金属化合物を使用することもできる。
【００９７】
本発明で用いる液晶性樹脂の配合率は、難燃性ポリアミド樹脂組成物全量を１００重量％とした場合、０．１〜１５重量％が好ましく、より好ましくは０．５〜１０重量％、更に好ましくは０．８〜８重量％である。成分（Ｈ）の配合率が該範囲を超えて少なすぎたり、多すぎたりする場合、良流動、薄肉難燃性かつ耐衝撃性などの機械特性のバランスのとれた材料が得られないので好ましくない。
【００９８】
本発明の難燃性ポリアミド樹脂組成物は、燃焼時の液滴の落下（ドリップ）防止剤して、フェノール系樹脂、シリコーン樹脂、フッ素系樹脂を用いて、更に高い燃焼性を付与することができる。該ドリップ防止剤は、難燃性ポリアミド樹脂組成物全量を１００重量％とした場合、０．０１〜３０重量％が好ましく、より好ましくは０．０５〜２５重量％、更に好ましくは０．１〜２０重量％配合するのがよい。
【００９９】
特にフッ素系樹脂はそのドリップ防止効果を好ましく発揮するため、本発明の難燃性ポリアミド樹脂組成物は、更に成分（Ｉ）としてフッ素系樹脂を含有してもよい。該フッ素系樹脂としては、ポリテトラフルオロエチレン、ポリヘキサフルオロプロピレン、（テトラフルオロエチレン／ヘキサフルオロポリプロピレン）共重合体、（テトラフルオロエチレン／パーフルオロアルキルビニルエーテル）共重合体、（テトラフルオロエチレン／エチレン）共重合体、（ヘキサフルオロポリプロピレン／プロピレン）共重合体、ポリビニリデンフルオライド、（ビニリデンフルオライド／エチレン）共重合体、などが挙げられるが、中でもポリテトラフルオロエチレン、（テトラフルオロエチレン／エチレン）共重合体が好ましい。該フッ素系樹脂を用いる場合には、０．０５〜１０重量％、好ましくは０．１〜３重量％配合するのがよい。
【０１００】
本発明の難燃性ポリアミド樹脂組成物は、更に成分（Ｊ）として金属酸化物を含有してもよい。金属酸化物を添加することにより、押出性、成形時の安定性や強度、耐熱性、成形品の端子腐食性などを向上させることができる。かかる金属酸化物としては、例えば、酸化カドミウム、酸化亜鉛、酸化第一銅、酸化第二銅、酸化第一鉄、酸化第二鉄、酸化コバルト、酸化マンガン、酸化モリブデン、酸化スズおよび酸化チタンなどが挙げられるが、なかでも酸化カドミウム、酸化第一銅、酸化第二銅、酸化チタンなどのＩ族および／またはII族の金属以外の金属酸化物が好ましく、特に酸化第一銅、酸化第二銅、酸化チタンが好ましいが、Ｉ族および／またはII族の金属酸化物であってもよい。押出性、成形時の安定性や強度、耐熱性、成形品の端子腐食性の他に、非着色性をさらに向上させるためには酸化チタンが最も好ましい。
【０１０１】
金属酸化物の添加量は力学的特性、成形性の面からポリアミド樹脂１００重量部に対して０．０１〜２０重量部が好ましく、特に好ましくは０．１〜１０重量部である。但し、力学的特性や比重の面から、全組成物に対しては０．０１〜１０重量％であることが好ましく、特に好ましくは０．０５〜８重量％である。
【０１０２】
本発明の樹脂組成物には、上述の成分の他にその目的に応じてさらに、充填材、導電性付与材、難燃剤（例えば、ハロゲン系、リン系、有機酸金属塩系（例えば有機スルホン酸金属塩、カルボン酸金属塩、芳香族スルホンイミド金属塩など）、無機系（例えば硼酸亜鉛、亜鉛、酸化亜鉛、ジルコニウム化合物など）、窒素系（窒素化グアニジン）、フッ素系、シリコーン系、など）、難燃助剤（例えば酸化カドミウム、酸化亜鉛、酸化第一銅、酸化第二銅、酸化第一鉄、酸化第二鉄、酸化コバルト、酸化マンガン、酸化モリブデン、酸化スズおよび酸化チタンなど）、顔料、染料、滑剤、離型剤、相溶化剤、分散剤、結晶核剤（例えばマイカ、タルク、カオリンなど）、可塑剤（例えばリン酸エステルなど）、熱安定剤、酸化防止剤、着色防止剤、紫外線吸収剤、流動性改質剤、発泡剤、抗菌剤、制振剤、防臭剤、摺動性改質剤、導電性付与剤、帯電防止剤（例えばポリエーテルエステルアミドなど）等の任意の添加剤を、単独でも、２種類以上ブレンドしたものでも使用することができる。
【０１０３】
ここでいう充填材とは、力学的特性（例えば引張強度、弾性率、伸度、衝撃強度、線膨張率、熱変形温度など）、熱的特性（例えば熱膨張率、熱伝導率など）、成形加工性（例えばスクリューへの噛込、粘度、充填度、成形収縮、バリ、ヒケ、表面平滑性など）、比重、異方性などの制御や、コストの低減など、本発明の樹脂組成物に用途に応じた効果を付与するために配合される。かかる充填材としては、例えば、マイカ、タルク、カオリン、セリサイト、ベントナイト、ゾノトライト、セピオライト、スメクタイト、モンモリロナイト、ワラステナイト、シリカ、炭酸カルシウム、ガラス繊維、ガラスビーズ、ガラスフレーク、ガラスマイクロバルーン、クレー、二硫化モリブデン、酸化チタン、酸化亜鉛、酸化アンチモン、ポリリン酸カルシウム、グラファイト、硫酸バリウム、硫酸マグネシウム、ホウ酸亜鉛、ホウ酸亜カルシウム、ホウ酸アルミニウムウィスカ、チタン酸カリウムウィスカ、高分子などを使用できる。これらの充填材は単独でも、２種類以上ブレンドしたものでもよい。かかる充填材の形状は粒子状（中実、中空）、粉末状、鱗片状、フレーク状、バルーン状、ウイスカ状（二次元、三次元）、繊維状、などの任意の形状を目的に応じて選択できる。また、かかる充填材は天然型であっても、合成型であってもよく、目的に応じて任意に選択できる。樹脂中での分散性、力学的特性、コスト、導電性などのバランスから、ガラス繊維、ワラステナイト、モンモリロナイト、酸化チタン、チタン酸カリウムが好ましい。特にガラス繊維を用いる場合は、連続糸で配合されても、連続繊維で配合した後に切断しても、不連続糸で配合されてもよいが、特に後述の長繊維ペレットの形態で配合されているのが好ましい。
【０１０４】
また、ここでいう導電性付与材とは、導電性を有しているものをいい、例えば金属（例えば粒子状、フレーク状、リボン状など）、金属酸化物（例えば粒子状など）、カーボン（例えば粉末状など）、グラファイト（例えば鱗片状、膨張粒子状、微細粉末状など）、そのもの自体が導電性を有する充填材や、非導電性の充填材の表面に導電体を被覆したもの、導電性高分子などが挙げられ、これらを単独で使用しても、２種類以上を併用してもよい。前述の充填材に被覆される導電体とは、導電性を有しているものを差し、例えば金属、金属酸化物、カーボンなどが挙げられるが、その中でも最も導電性の高い金属が好ましい。前記金属としては、例えばニッケル、チタン、アルミニウム、クロム、亜鉛、アンチモン、銅、銀、金等を単独もしくは併用することができ、前記金属は少なくとも１層、必要に応じて複数層にて充填材に被覆されるのが好ましい。充填材への導電体の被覆方法については、特に制限はないが、好ましくは電解や無電解によるメッキ法、イオンプレーティング法、ＣＶＤ法、ＰＶＤ法、蒸着法などにより高い密着強度で被覆されているのが好ましい。
【０１０５】
また、本発明で用いられる導電性付与材の平均粒径は０．５〜５００μｍの範囲内であることが好ましい。より好ましくは１〜１００μｍの範囲内であり、更に好ましくは１．５〜５０μｍの範囲内である。とりわけ２〜２５μｍの範囲内であることが好ましい。平均粒径が０．５μｍ未満では、成形品中における分散性に劣りやすく、さらに成形時の流動性が低下し、薄肉成形性に劣るなどの問題を生じるため好ましくない。一方、平均粒径が５００μｍを超えると、導電性付与効果に劣り、所望の導電性付与効果が得られないため好ましくない。
【０１０６】
本発明で用いられる導電性付与材としては、より高い導電性付与効果を発現するために、それ自体が高い導電性を有していることが好ましいため、特に金属、金属酸化物、グラファイトから選ばれる少なくとも１種類であることが好ましい。
【０１０７】
かかる金属としては、例えばニッケル、チタン、アルミニウム、クロム、鉄、ステンレス、アルミニウム、錫、鉛、アンチモン、亜鉛、カドミウム、マグネシウム、タングステン、リチウム、モリブデン、ベリリウム、コバルト、バナジウム、マンガン、アンチモン、銅、黄銅、銀、金、白金、およびこれら２種類以上の組み合わせた合金、これらを主成分とする合金、これらとリンとの化合物などが挙げられ、これらは単独で使用しても、２種類以上を併用してもよい。中でも、銀、ニッケル、チタンが導電性付与効果が大きいため、好ましい。
【０１０８】
また、かかる金属は、例えば粒子状、フレーク状、リボン状などの任意の形態をとることができるが、導電性付与効果の面から、粒子状および／またはフレーク状であるのが好ましい。特に粒子状である場合、球状粉、粒状粉、樹枝状粉、片状粉、角状粉、海綿状粉、不規則型粉などの任意の形状をとることができるが、中でも樹枝状粉、片状粉、角状粉が導電性付与効果、加工コスト抑制効果に優れるため好ましい。
【０１０９】
かかる金属酸化物としては、例えばＩＴＯ（イソジウム・錫酸化物）、ＡＴＯ（アンチモン・錫酸化物）、酸化チタンなどが挙げられ、これらは単独で使用しても、２種類以上を併用してもよい。
【０１１０】
かかるグラファイトは、鱗片状、膨張粒子状、微細粉末状など任意の形態をとることができるが、導電性付与効果の面から、鱗片状、微細粉末状であるのが好ましい。
【０１１１】
本発明の樹脂組成物は、該樹脂組成物１００重量％に対して、導電性付与材が０．０１〜１５重量％の範囲内で配合されていることが好ましい。導電性付与材が０．０１重量％未満であると、所望の導電性付与効果が得にくく、１５重量％を越えると、成形時の流動性が低下し、薄肉成形性に劣るだけでなく、高コスト・高比重となり好ましくないことがある。より好ましくは０．０５〜１０重量％の範囲内であり、更に好ましくは０．１〜８重量％の範囲内である組成である。
【０１１２】
また、かかる充填材や導電性付与材などは、膨潤化剤により膨潤されていてもよいし、有機化剤により有機化されていてもよい。膨潤化剤または有機化剤としては、イオン交換などにより充填材などを膨潤化または有機化し得るものなら特に制限はなく、具体的にはε−カプロラクタム、１２−アミノドデカン酸、１２−アミノラウリン酸、アルキルアンモニウム塩（ジメチルジアルキルアンモニウムなど）などが挙げられる。特にポリアミド樹脂、ポリプロピレン樹脂、ポリアセタール樹脂、スチレン系樹脂、アクリル系樹脂などに膨潤化もしくは有機化された充填材（好ましくはモンモリロナイト、マイカ、サポナイト、ヘクトライト、セピオライト）が配合されていると、充填材のナノオーダーでの分散が可能となり、より少ない配合量で所望の特性が得られるため好ましい。
【０１１３】
なお、本発明の樹脂組成物に上記充填材、導電性付与剤、難燃剤などを配合する場合には、樹脂などに予め押出機などにより混練してもよいし、樹脂組成物とは別にドライブレンド、塗布などにより配合してもよい。また、樹脂の重合時に予め混合しておいてもよい。
【０１１４】
本発明の難燃性ポリアミド成形品は、例えば射出成形（射出圧縮成形、ガスアシスト射出成形、インサート成形など）、ブロー成形、回転成形、押出成形、プレス成形、トランスファー成形（ＲＩＭ成形など）、フィラメントワインディング成形などの公知の成形方法によって成形されるが、最も望ましい成形法は、生産性の高い射出成形法により成形するのがよい。
【０１１５】
かかる成形に用いられる成形材料の形態としては、ペレット、ＢＭＣ、ＳＭＣ、スタンパブルシート、プリプレグ（シート、ヤーンなど）等を使用することができるが、最も望ましい成形材料は射出成形に用いられるペレットであり、最も望ましい形態は長繊維ペレットである。
【０１１６】
本発明でいうペレットとは、成分（Ａ）〜（Ｆ）、および必要に応じて（Ｇ）〜（Ｊ）、その他の成分が、所望量配合されるように、それぞれ、もしくは幾つかを必要回数だけ押出機などを用いて混練し、押し出したものを所望長さに切断したもの（以下、この一連の工程をコンパウンドと記す）を指す。また、前記ペレットと、少なくとも成分（Ｆ）を含まないペレットなどとをドライブレンドすることによって得られたものも同様にペレットと呼ぶ。コンパウンドに使用する成分（Ｆ）は、チョップド糸、ミルド糸のような不連続糸であっても連続糸であってもよい。
【０１１７】
本発明の難燃性ポリアミド樹脂組成物からなる難燃性ポリアミド成形品が、高い難燃性、導電性、力学的特性（強度、剛性、衝撃強度等）を兼ね備えるためには、成形品中の成分（Ｆ）の長さを長くすることが有効であるが、そのためには、前述のペレットの中でも長繊維ペレットの形態をとることが望ましい。
【０１１８】
長繊維ペレットを用いて成形した場合、成形品中での成分（Ｆ）の長さを長く維持することができるため、力学的特性の他に、特に難燃性、および導電性を飛躍的に向上させることができる。つまり、通常のペレットでは高い難燃性、および導電性を達成できない場合でも、長繊維ペレットを用いた場合には、ＵＬ−９４規格における１．２ｍｍ厚さでの難燃性がＶ−０クラス、および体積固有抵抗が１００Ω・ｃｍ以下といった高い難燃性（特にドリップ防止効果）、および導電性の達成が可能となる。特に、成分（Ｆ）の配合量が２０重量％以下のような低い配合率の場合には、通常のペレットに比べて難燃性（特にドリップ防止効果）、および導電性の発現効果は顕著であり、このような範囲の成分（Ｆ）の配合率で長繊維ペレットを用いることは、高い難燃性、および導電性を達成するためには非常に有効である。もちろん、力学的特性（特に衝撃強度）に関しても、同様にその向上効果は絶大である。
【０１１９】
一方、成分（Ｆ）の配合率が２０重量％を越えるような高い配合率の場合には、通常のペレットでも難燃性、および導電性をある程度達成することができる。但し、難燃性、導電性、力学特性（特に衝撃強度）に関しては、その向上効果は小さく、長繊維ペレットの改善効果には及ばない。
【０１２０】
本発明の長繊維ペレットのペレット長さとしては、２〜２６ｍｍの範囲内であることが好ましい。より好ましくは４〜１５ｍｍの範囲内であり、更に好ましくは５〜１０ｍｍの範囲内である。
【０１２１】
本発明でいう長繊維ペレットとは、例えば特公昭６３−３７６９４公報に示されるような、繊維がペレットの長手方向にほぼ平行に配列し、ペレット中の繊維の長さがペレット長さとほぼ同一、もしくはそれ以上であるペレットが含まれるものを指す。この場合、少なくとも成分（Ａ）および／もしくは成分（Ｂ）を含む本発明中の各成分は、成分（Ｆ）束中に含浸されていても、成分（Ｆ）束に被覆されていてもよい。
【０１２２】
含浸された長繊維ペレットの場合、例えば、
（１）樹脂のエマルジョン、サスペンジョン、溶液あるいは溶融物の入った含浸槽中を用いて、樹脂など本発明の各成分を含浸させる方法、
（２）樹脂粉末などを成分（Ｆ）中に分散させた後に加熱して、樹脂など本発明の各成分を含浸させる方法、
（３）溶融樹脂を押し出したクロスヘッドダイを用いて、成分（Ｆ）を引き抜きながら、樹脂など本発明の各成分を含浸させる方法、
などの公知の含浸方法を利用することができるが、本発明の成分を均一且つ所望量配合するためには、上記（３）に記載の含浸方法を利用することが好ましい。
【０１２３】
被覆された長繊維ペレットの場合、少なくとも成分（Ｆ）束からなる芯部と、少なくとも成分（Ａ）および／もしくは成分（Ｂ）からなる鞘部とからなる芯鞘型の長繊維ペレットであるのが好ましい。前記芯鞘型の長繊維ペレットの場合、成分（Ｆ）束は、成分（Ａ）、（Ｂ）中で最も配合量が多い樹脂の溶融粘度以下である樹脂（以下、低粘度樹脂と記す）で予め含浸され、成分（Ｆ）と低粘度樹脂との複合体を形成した後に、少なくとも成分（Ａ）および／もしくは成分（Ｂ）を含む本発明中の各成分で被覆されていることが望ましい。ここで低粘度樹脂としては、例えば、エポキシ樹脂、アルコール（または水）可溶性ポリアミド樹脂、成分（Ａ）および／もしくは成分（Ｂ）の分子量以下のポリアミド樹脂、あるいは成分（Ｇ）、成分（Ｈ）などを挙げることができる。なお、成分（Ｂ）に関しては、成分（Ａ）などと予め混練し長繊維ペレットの鞘部中に配置してもよいし、長繊維ペレットとは別にドライブレンドにて配合してもよい。また、成分（Ｅ）に関しては、成分（Ｆ）束中に予め混合していても、成分（Ｆ）のサイジング剤中に予め混合していても、前記低粘度樹脂中に混練されていてもよい。
【０１２４】
本発明のペレットの配合形態は特に制限されないが、望ましくは、少なくとも成分（Ａ）および／もしくは成分（Ｂ）を含み、成分（Ｆ）を含まないペレットと、低粘度樹脂で成分（Ｆ）束を含浸し、予め低粘度樹脂と成分（Ｆ）との複合体を形成した後、少なくとも成分（Ａ）および／もしくは成分（Ｂ）で、前記複合体を被覆した長繊維ペレットとを、ドライブレンドしたものがよい。特に望ましくは、成分（Ａ）、成分（Ｃ）、成分（Ｅ）（必要に応じて成分（Ｊ））をコンパウンドした成分（Ｆ）を含まないペレットと、成分（Ａ）、成分（Ｂ）、成分（Ｄ）、成分（Ｅ）（必要に応じて成分（Ｈ）、成分（Ｉ）、成分（Ｊ））を含む本発明中の各成分で、予め成分（Ｇ）により成分（Ｆ）束が含浸された複合体を被覆した長繊維ペレットとを、ドライブレンドしたものがよい。
【０１２５】
前記ペレットを用いた射出成形による難燃性ポリアミド成形品において、高い難燃性、導電性、力学的特性（特に強度、衝撃強度）を同時に達成するためには、成形品中の成分（Ｆ）の長さを長くすることが有効であることは前述の通りであるが、この場合、特に成形条件および射出成形機、さらに金型の影響を考慮しなければならない。成形条件に関していえば、背圧が低いほど、射出速度が遅いほど、スクリュー回転数が遅いほど、成形品中の成分（Ｆ）の長さが長くなる傾向があり、特に背圧は、計量性が不安定にならない程度に、できるだけ低く設定するのが望ましい。望ましい背圧は０．１〜１ＭＰａ である。射出成形機については、ノズル径が太いほど、ノズルのテーパー角度が小さいほど、スクリュー溝深さが深いほど、圧縮比が低いほど、成形品中の成分（Ｆ）の長さが長くなる傾向がある。金型については、スプルー径、ランナー径、ゲート径を大きくするほど、成形品中の成分（Ｆ）の長さが長くなる傾向がある。
【０１２６】
上述のように、本発明の難燃性ポリアミド成形品が、高い難燃性、導電性、力学的特性を兼ね備えるためには、該成形品中に含まれる炭素繊維総量の少なくとも３重量％が１〜１５ｍｍの範囲内であることが好ましい。より好ましくは、炭素繊維総量の少なくとも５重量％が１〜１０ｍｍの範囲内であり、一層好ましくは炭素繊維総量の少なくとも５重量％が１〜７ｍｍの範囲内である。とりわけ好ましくは、炭素繊維総量の少なくとも８重量％が１〜７ｍｍの範囲内である。
【０１２７】
本発明における難燃性ポリアミド樹脂組成物、およびその成形品は、高い導電性、高い薄肉成形性だけではなく、成分の（Ｂ）、（Ｃ）、（Ｄ）、（Ｅ）の配合に起因する高い難燃性（特にドリップ防止性）を兼ね備えているため、ＵＬ−９４規格において、１．２ｍｍ厚での難燃性がＶ−０クラスまたはそれよりも良好なものが得られる成形品として用いられる。
【０１２８】
ここで、Ｖ−０クラスの難燃性とは、ＵＬ−９４規格（Ｕｎｄｅｒｗｒｉｔｅｒｓ Ｌａｂｏｒａｔｏｒｉｅｓ Ｉｎｃ．で考案された米国燃焼試験法）において、燃焼時間やその状態、延焼の有無、滴下（ドリップ）の有無やその滴下物の燃焼性などにより規定されているＶ−０クラスの条件を満たした難燃性を指す。また、Ｖ−０よりも良好な難燃性とは、前記Ｖ−０クラスにおける規定値よりも更に少ない燃焼時間を示す難燃性や、試験片の厚みがより薄い場合においてＶ−０クラスの規定条件を満たす難燃性を指す。
【０１２９】
なお、本発明においては、ＵＬ−９４試験片を成形する場合、基本的に成分（Ｆ）を試験片の長辺方向と直交方向に配向させるようにして試験片を得る。特に射出成形にて成形する場合は、試験片の長辺方向全長に渡るフィルムゲートにて充填させる金型を用いて成形して試験片を得る。成形にあたっては、射出成形機のシリンダ温度は２６０〜２８０℃の範囲内、金型温度は８０℃にて成形を行う。
【０１３０】
本発明の難燃性ポリアミド樹脂組成物、およびその成形品は、その成分の配合比によっては更に高い難燃性を付与することができるため、０．８ｍｍ（１／３２インチ）厚での難燃性がＶ−０クラスまたはそれよりも良好なレベルで使用されるのが好ましい。
【０１３１】
本発明における難燃性ポリアミド成形品は、高い難燃性、高い薄肉成形性だけではなく、成分（Ｅ）、（Ｆ）に起因する高い導電性を兼ね備えているため、体積固有抵抗値は、１００Ω・ｃｍ以下である難燃性ポリアミド成形品として用いるのが望ましい。体積固有抵抗値が１００Ω・ｃｍを越える場合、電磁波シールド材などの用途には適応しにくく、用途が限定されるといった問題を有する。より望ましい体積固有抵抗値は５０Ω・ｃｍであり、更に望ましい体積固有抵抗値は１０Ω・ｃｍである難燃性ポリアミド成形品として用いるのがよい。
【０１３２】
ここでいう体積固有抵抗値とは、直方体形状を有している試験片の導電ペーストを塗布された両端部の電気抵抗値から、測定機器、治具などの接触抵抗値を減じた値について、前記試験片の端部面積を乗じ、試験片長さで除すことにより算出する。本発明では、単位はΩ・ｃｍを用いた。
【０１３３】
本発明における難燃性ポリアミド成形品は、高い難燃性、高い薄肉成形性だけではなく、成分（Ｆ）に起因する高い剛性を兼ね備えているため、ＡＳＴＭ Ｄ７９０規格（スパン間距離Ｌ／板厚Ｄ＝１６）において、板厚６．４ｍｍ（１／４インチ）での曲げ剛性が８〜４０ＧＰａの範囲内であり、望ましくは１０〜３０ＧＰａの範囲内、特に望ましくは１２〜２５ＧＰａの範囲内である難燃性ポリアミド成形品として用いるのがよい。
【０１３４】
本発明における難燃性ポリアミド成形品は、高い難燃性（特にドリップ防止性）に加え、薄肉成形性（成形時の流動性）、導電性を兼ね備えているので、従来の難燃性ポリアミド成形品より肉厚を薄くすることが可能であり、肉厚が４ｍｍ以下である薄肉成形品として用いるのが最適である。
好ましくは、肉厚３ｍｍ以下、更に好ましくは２ｍｍ以下である薄肉成形品として用いるのが本発明の効果をより発揮できる。とりわけ好ましくは、肉厚１．６ｍｍ以下である薄肉成形品として用いるのがよい。ここでいう成形品の肉厚とは、成形品のうち、リブ部分やボス部分などの突起物などを除いた平板部分の肉厚を指す。
【０１３５】
本発明における難燃性ポリアミド成形品の用途としては、薄肉成形品における高い難燃性、成形性、力学的特性（特に剛性）が求められる電子・電気機器用部材などが挙げられる。本発明の難燃性ポリアミド成形品は、高い剛性、軽量化、電磁波シールド性などが達成できるため、携帯用の電子・電気機器、ＯＡ機器、家電機器、自動車分野などのハウジング、ケーシング、またそれらの部品などの用途に有効である。より具体的には、大型ディスプレイ、ノート型パソコン、携帯用電話機、ＰＨＳ、ＰＤＡ（電子手帳などの携帯情報端末）、ビデオカメラ、デジタルスチルカメラ、携帯用ラジオカセット再生機などのハウジング、ケーシング、またはそれらの部品などに好んで使用される。
【０１３６】
また、高い導電性を有しているため、炭素繊維の少量添加で帯電／放電防止性を付与することができ、それらの特性が必要とされる部材、例えばＩＣトレー、シリコンウェーハー運搬用バスケットなどへの適応にも有用である。
【０１３７】
【実施例】
以下、実施例によって本発明を更に詳細に説明するが、下記実施例は本発明を制限するものではなく、前・後記の主旨を逸脱しない範囲で変更実施することは、全て本発明の技術範囲に包含される。
【０１３８】
得られた難燃性ポリアミド成形品の評価項目、およびその方法は下記の通り。
（ａ）難燃性
ＵＬ−９４規格に準拠した難燃性試験にて評価した。用いた試験片の板厚は１．２ｍｍ厚、および０．８ｍｍ（１／３２インチ）厚さとした。なお射出成形は、試験片の長辺方向全長に渡るフィルムゲートにて充填させる金型を用いて、射出成形機ＩＳ１００（東芝機械製、型締力１００ｔ）を用いて、シリンダ温度２８０℃、金型温度８０℃にて行った。
（ｂ）体積固有抵抗
ファンゲートにて射出成形した幅１２．７ｍｍ×長さ６５ｍｍ×厚さ２ｍｍの試験片を、絶乾状態（水分率０．１％以下）で測定に供した。まず、幅×厚さ面に導電性ペースト（藤倉化成（株）製ドータイト）を塗布し、十分に導電性ペーストを乾燥させてから、その面を電極に圧着し、電極間の電気抵抗値をデジタルマルチメーター（ＦＬＵＫＥ社製）にて測定する。前記電気抵抗値から測定機器、治具等の接触抵抗を減じた値に、導電性ペースト塗布面の面積を乗じ、次いで、その値を試験片長さで除したものを体積固有抵抗値とした（単位はΩ・ｃｍ）。なお射出成形は、シリンダ温度２８０℃、金型温度７０℃にて行った。
（ｃ）曲げ剛性
ＡＳＴＭ Ｄ ７９０規格（スパン間距離Ｌ／板厚Ｄ＝１６）に準拠した曲げ剛性にて評価した（単位はＧＰａ）。用いた試験片の板厚は６．４ｍｍ（１／４インチ）厚さで、水分率０．１％以下で試験に供した。なお射出成形は、シリンダ温度２８０℃、金型温度７０℃にて行った。
（ｄ）衝撃強度
ＡＳＴＭ Ｄ ２５６規格に準拠したモールドノッチ有りＩＺＯＤ衝撃強度にて評価した（単位はＪ／ｍ）。用いた試験片の板厚は３．２ｍｍ（１／８インチ）厚さで、水分率０．１％以下で試験に供した。なお射出成形は、シリンダ温度２８０℃、金型温度７０℃にて行った。
（ｅ）外観品位
８点ピンゲートにて射出成形した、幅１５５ｍｍ×長さ１９０ｍｍ×厚さ１ｍｍの投影面積を有し、高さ１２ｍｍである箱型試験片について、表面光沢の有無、ヒケ、ウェルド、炭素繊維の浮き・分散などの欠陥について、◎（前述欠陥なし）、○（前述欠陥のいずれか１つ有する）、△（前述欠陥をいずれか２つ有する）、×（前述欠陥を全て有する）、で相対的に目視により評価した。なお射出成形は、シリンダ温度２８０℃、金型温度６０℃にて行った。
（ｆ）薄肉成形性
ファンゲートにて、幅１５０ｍｍ×長さ１５０ｍｍ×厚さ１ｍｍの薄肉平板を射出成形する際の射出圧力で、薄肉成形性を評価した（単位はＭＰａ）。射出圧力が低いほど、薄肉成形性（射出成形時の流動性）に優れるといえる。なお射出成形は、射出成形機Ｊ１５０ＥＩＩ−Ｐ（日本製鋼所製、型締力１５０ｔ）を用いて、シリンダ温度２８０℃、金型温度７０℃にて行った。
（ｇ）塗装性
（ｆ）項にて成形した薄肉平板を、温度６６℃、湿度８５％にて５０日間放置した際のブリードアウトの様子について、○（ブリードアウトなし）、△（ややブリードアウト気味）、×（ブリードアウト有り）、で相対的に目視により評価した。
（参考例１、比較例１）
成分（Ａ）、成分（Ｂ）、成分（Ｄ）、成分（Ｅ）と、チョップド糸にされた成分（Ｆ）とを２軸押出機にて、溶融した成分（Ａ）、成分（Ｂ）、およびその他の成分を、成分（Ｆ）束中に含浸させながら押し出す。成分（Ｆ）としては不連続のもののみを含有する前述のようにして得られた樹脂ガットを、カッターで５ｍｍの長さに切断してペレットを得る。
【０１３９】
また、所望量の成分（Ａ）、成分（Ｃ）、成分（Ｅ）を１軸押出機にてコンパウンドし、難燃マスターペレット１を得る。得られた難燃マスターペレット１と、前記ペレットとを所望比率にてドライブレンドし、８０℃にて５時間以上真空中で乾燥させた後、（ａ）〜（ｆ）項記載の各試験の射出成形に供した。
【０１４０】
各成分の配合率、および評価結果を表１に示す。
【０１４１】
参考例１では、１．２ｍｍ厚、および０．８ｍｍ（１／３２インチ）厚さの難燃性はＶ−０クラス判定で、難燃性に優れ、且つ薄肉成形性にも優れていた。しかし、比較例１は、難燃性はＶ−２判定であり、難燃性に劣った。
（実施例１〜５、比較例２〜４）
まず、所望量の成分（Ａ）、成分（Ｂ）、成分（Ｄ）、成分（Ｅ）、必要に応じて成分（Ｇ）、成分（Ｈ）を２軸押出機にてコンパウンドし、難燃マスターペレット２を得る。得られた難燃マスターペレット２を１軸押出機にて、その先端に取り付けたクロスヘッドダイ中に十分混練された状態で押し出すと同時に、成分（Ｆ）の連続糸も前記クロスヘッドダイ中に連続的に供給することによって、溶融した成分（Ａ）、成分（Ｂ）、およびその他の成分を、成分（Ｆ）束中に十分含浸させる。ここでクロスヘッドダイとは、そのダイ中で成分（Ｆ）束を開繊させながら、溶融した成分（Ａ）、成分（Ｂ）、およびその他の成分を、成分（Ｆ）束中に含浸させる装置のことをいう。成分（Ｆ）としては、そのほとんどが連続糸であるものを含有する前述のようにして得られた樹脂ストランドを、カッターで７ｍｍの長さに切断して長繊維ペレットを得る。
【０１４２】
得られた長繊維ペレットと前記難燃マスターペレット１とを所望比率にてドライブレンドし、８０℃にて５時間以上真空中で乾燥させた後、（ａ）〜（ｆ）項記載の各試験の射出成形に供した。
【０１４３】
各成分の配合率、および評価結果を表１に示す。
【０１４４】
実施例１〜５のいずれの難燃性ポリアミド成形品も、１．２ｍｍ厚、および０．８ｍｍ（１／３２インチ）厚さの難燃性はＶ−０クラス判定で難燃性に優れ、且つ薄肉成形性にも優れた。成分（Ｈ）を加えた実施例３、４は、とりわけ薄肉成形性に優れた。一方、比較例１、２の難燃性ポリアミド成形品は、難燃性は１．２ｍｍ厚、０．８ｍｍ厚共にＶ−２判定であり、難燃性に劣った。また、比較例３、４の難燃性ポリアミド成形品は、難燃性は１．２ｍｍ厚ではＶ−０クラス判定であるものの、０．８ｍｍ厚ではＶ−２判定となりるだけでなく、薄肉成形性、とりわけ塗装性に劣った。
【０１４５】
【表１】

【０１４６】
なお、表１における各成分の表記は下記に準じる。
成分（Ａ）
Ｎｙ６：ナイロン６樹脂［ηｒ＝２．４］
ｍ−Ｎｙ６：変性ナイロン６樹脂［上記Ｎｙ６のアミノ末端基を無水酸にて変性したナイロン６樹脂］
成分（Ｂ）
Ｎｙ６ＴＩ：ナイロン６Ｔ／６Ｉ共重合樹脂［ηｒ＝２．１］
ＭＸＤ６：ポリメタキシリレンアジパミド［ηｒ＝２．２］
Ｎｙ６６Ｉ：ナイロン６６／６／６Ｉ共重合樹脂［ηｒ＝２．０］
成分（Ｃ）
ＲＰ：赤リン［燐化学工業（株）製ノーバエクセル１４０：平均粒径＝約３０μｍ、フェノール系熱硬化性樹脂被覆、導電率＝約１８０〜２００μＳ／ｃｍ］
成分（Ｄ）
Ｍｇ：水酸化マグネシウム［協和化学工業（株）製キスマ５Ｅ−Ｕ：合成型、平均結晶粒径＝約１．０μｍ、アミド系高極性樹脂被覆、粒状品］
成分（Ｅ）
ＣＢ１：カーボンブラック［Ｉ₂ ／Ｉ₁ ＝０．６８、Ｉ₂ ／Ｉ₃ ＝０．６０］
ＣＢ２：カーボンブラック［Ｉ₂ ／Ｉ₁ ＝０．３５、Ｉ₂ ／Ｉ₃ ＝０．３９］
成分（Ｆ）
ＣＦ１：炭素繊維［東レ（株）製トレカＴ７００ＳＣ−１２Ｋ−５０Ｃ：平均繊維直径＝約７μｍ］
ＣＦ２：炭素繊維［東レ（株）製トレカＴ３００Ｂ−１２Ｋ−５０Ｂ、平均繊維直径＝約７μｍ］
成分（Ｇ）
Ｔ／Ｐ：テルペン・フェノール共重合樹脂［ヤスハラケミカル（株）製ＹＰ９０２］
成分（Ｈ）
ＬＣＰ：液晶性樹脂［ｐ−ヒドロキシ安息香酸５２８重量部、４，４´−ジヒドロキシビフェニル１２６重量部、テレフタル酸１１２重量部、固有粘度が約０．６ｄｌ／ｇのポリエチレンテレフタレ−ト８６４重量部及び無水酢酸５８６重量部を撹拌翼、留出管を備えた反応容器に仕込み、重合を行うことにより得られる、芳香族オキシカルボニル単位４２．５モル％、芳香族ジオキシ単位７．５モル％、エチレンジオキシ単位５０モル％、芳香族ジカルボン酸単位５７．５モル％からなる融点２０８℃、溶融粘度１５Ｐａ・ｓの液晶性樹脂］
その他の成分
ＷＯＬ：ワラステナイト［キンセイマテック（株）製ＦＰＷ＃４００Ｓ］
表１の結果から以下のことが明らかである。
１．成分（Ｂ）の効果（実施例１、２と比較例２〜４との比較）
芳香族含有ポリアミド樹脂を配合していない比較例２に比べて、本発明の芳香族含有ポリアミド樹脂（およびカーボンブラック）を配合している実施例１、２は、難燃性が著しく高い成形品を得ることができ（Ｖ−０クラス）、その優位性は明らかである。
【０１４７】
また、芳香族含有ポリアミド樹脂を配合しなくても１．２ｍｍ厚でのＶ−０クラスの難燃性を達成している比較例３、４に比べて、芳香族含有ポリアミド樹脂（および金属水酸化物）を配合している実施例１〜２は、塗装性（ブリードアウト）や燃焼時の有毒ガス発生などの問題を引き起こす原因と成り得る成分（Ｃ）の添加量を減量することができ、前記問題を改善することができるという利点を有する。
【０１４８】
なお、実施例１、２は、芳香族含有ポリアミド樹脂の配合により、ヒケ、ウェルドなどを最小限に抑えることができるため、比較例１、２より外観品位に優れる。
２．成分（Ｅ）配合の効果（実施例１、２と比較例１、２との比較）
カーボンブラックを配合していない比較例１、２に比べて、本発明のカーボンブラックを配合している実施例１、２は、難燃性に大きく優れ（Ｖ−０クラス）、且つ体積固有抵抗を低くすることができ、その優位性は明らかである。
３．成分（Ｅ）種類の効果（参考例１、実施例１〜５、比較例３と比較例４との比較）
本発明の範囲外であるカーボンブラックを配合している比較例４は、射出圧力が大幅に高く、薄肉成形性に著しく劣った。本発明の範囲に含まれるカーボンブラックを配合している参考例１、実施例１〜５または比較例３は、射出圧力を低くすることができ、薄肉成形性について優れる。また外観欠陥についても、比較例４に比べて、参考例１、実施例１〜５は欠陥が少なく、外観品位に優れた。
４．長繊維ペレットの効果（参考例１と実施例１との比較）
通常のペレットを用いた参考例１に比べて、長繊維ペレットを用いた実施例１は、成分（Ｆ）の配合率が低いにも関わらず、難燃性は同等、体積固有抵抗はより低くすることができ、難燃性・導電性をより高い次元で兼ね備えた成形品を得ることができる。
【０１４９】
これは、参考例１よりも実施例１の方が、成形品中の成分（Ｆ）の長さを長くできることによる。つまり、実施例１の成形品中の重量的平均繊維長さｌｗ＝０．４９３ｍｍ（１ｍｍ〜７ｍｍの範囲内である成分（Ｆ）が８重量％以上）であったのに対して、参考例１の場合には、ｌｗ＝０．２１６ｍｍ（１ｍｍ以上の成分（Ｆ）は１重量％未満）であったことによる。なお、ｌｗの算出は、成形品から成分（Ｆ）のフィラメントのみを、任意に少なくとも４００以上抽出し、その長さを１μｍ単位まで光学顕微鏡もしくは走査型電子顕微鏡にて測定して、下記の（数式１）、もしくは（数式２）を用いて算出した。但し、Ｗｉは長さｌｉの成分（Ｆ）の重量、Ｎｉは長さｌｉの成分（Ｆ）の数とする。
【０１５０】
（数式１） ｌｗ＝Σ（Ｗｉ×ｌｉ）／ΣＷｉ
（数式１）は一定直径の成分（Ｆ）に対しては、（数式２）の様に表すことができる。
【０１５１】
（数式２） ｌｗ＝Σ（Ｎｉ×ｌｉ²）／Σ（Ｎｉ×ｌｉ）
本発明では、ｌｗを測定する際の成分（Ａ）、（Ｂ）を除去する方法として、成分（Ａ）、（Ｂ）のみを溶解させ、含有される成分（Ｆ）は溶解させない溶媒などに成形品を一定時間浸漬し、成分（Ａ）、（Ｂ）を十分溶解させた後、濾過などにより成分（Ｆ）と分離する手法を採用した。
【０１５２】
これらの比較から、難燃性、および導電性に及ぼす樹脂成形品中の成分（Ｆ）の長さの重要性は明らかであり、本発明で用いられる難燃性ポリアミド樹脂組成物としては、長繊維ペレットの形態をとることがより望ましい。
５．成分（Ｈ）の効果（実施例１、２と実施例３、４との比較）
通常のペレットである参考例１に比べて、長繊維ペレットである実施例１、２は、成分（Ｆ）の配合率が低いにも関わらず射出圧が高く、流動性に劣る。しかし、成分（Ｈ）の配合により、実施例３、４は長繊維ペレットであるにも関わらず流動性を大きく向上しており、成分（Ｈ）は流動性を大幅に向上させることが可能なことが明らかである。
【０１５３】
【発明の効果】
本発明によれば、高い難燃性（特にドリップ防止性）、薄肉成形性（成形時の流動性など）、外観品位、および高い導電性を兼ね備えた難燃性ポリアミド樹脂組成物とその成形品を提供することができる。このような難燃性ポリアミド樹脂組成物とその成形品は、特に電子機器類のハウジング、ケーシングなどを始め、前記特性を必要とする幅広い産業分野に好適であり、その工業的な効果は大きい。
【図面の簡単な説明】
【図１】本発明の難燃性ポリアミド樹脂組成物を構成するカーボンブラックの一例のラマンスペクトル図である。
【符号の説明】
Ｉ₁ ：ラマンシフト１３６０ｃｍ^-1付近に現れるラマン散乱強度の極大値
Ｉ₂ ：ラマンシフト１４８０ｃｍ^-1付近に現れるラマン散乱強度の極小値
Ｉ₃ ：ラマンシフト１５８０ｃｍ^-1付近に現れるラマン散乱強度の極大値[0001]
BACKGROUND OF THE INVENTION
The present invention provides a flame retardant polyamide having high flame retardancy (particularly, droplet drop prevention during combustion (drip) prevention), thin-wall moldability (such as fluidity during molding), appearance quality, and high conductivity. The present invention relates to a resin composition and a molded product thereof.
[0002]
[Prior art]
Conventionally, most of the flame retarding of resins has been achieved by a combination of an organic halogen flame retardant and an antimony oxide flame retardant aid. However, in recent years, toxic gas resulting from the flame retardant has been a problem, and there is a strong demand for flame retardant with a non-halogen flame retardant.
[0003]
As non-halogen flame retardants, nitrogen compound flame retardants, phosphorus flame retardants, metal hydroxide flame retardants, and the like are often used.
[0004]
Nitrogen-based flame retardants are basically inferior in heat resistance, and foaming or the like occurs when molding at about 300 ° C., which has a large problem in molding. Moreover, when the inorganic filler is added, the flame retarding effect by the drip promotion leads to the result that the flame retardancy is greatly inhibited.
[0005]
The phosphorus-based flame retardant exhibits an excellent flame retardant effect, but when applied to a low-viscosity resin, drip cannot be suppressed, and high flame retardancy cannot be achieved alone.
[0006]
Metal hydroxide flame retardants are environmentally friendly and clean flame retardants. However, in order to make them flame retardant, they need to be added in a larger amount than other flame retardants, and the mechanical properties are also reduced. However, the fluidity at the time of molding is greatly inferior, and the molding itself becomes difficult especially when molding a thin molded product.
[0007]
In order to solve these problems, a phosphorus flame retardant and a metal hydroxide flame retardant may be used in combination. For example, Japanese Patent Application Laid-Open No. 63-243158 (hereinafter referred to as the first example) describes that red phosphorus and magnesium hydroxide are blended at a specific ratio to achieve both flame retardancy and tracking resistance. Has been.
[0008]
However, in the first example, although the flame retardancy of a thick molded product having a thickness of 1.5 to 3 mm is described, the flame retardancy of a thin molded product having a thickness below this range is, for example, There are practical applications such as housings and casings for electronic / electrical equipment, OA equipment, home appliances, etc. (especially housings for notebook personal computers that require thin-walled molded products), but there is no description about them. Therefore, the present inventors evaluated the flame retardancy of UL-94 standard with a 1.2 mm-thick molded product of the polyamide composition of the preceding example 1, particularly a composition with a small amount of mineral reinforcing fibers, It has been found that the flame retardancy of V-0 class cannot be achieved due to the drop (drip) of the droplet during combustion.
[0009]
Furthermore, in Prior Example 1, it is described that carbon black may be blended as a pigment. The blending of this carbon black is aimed at coloring as described in the preceding example 1, and there is no description about the effect of improving the flame retardancy (particularly the drip prevention) and the conductivity imparting effect by blending the carbon black. can not see. That is, the object of the present invention is clearly different from that of the present invention having carbon black as an essential component as a drip inhibitor / conductivity imparting material.
[0010]
JP-A-10-120798 (previous example 2) describes that a resin composition comprising a semi-aromatic polyamide and an aliphatic polyamide is flame-retarded with red phosphorus and an inorganic compound. Has been. However, the blending of the aliphatic polyamide and the semi-aromatic polyamide in the preceding example 2 is blended with aliphatic nylon for the purpose of increasing the surface impact strength of the molded product, which is insufficient with the semi-aromatic polyamide alone. This is fundamentally different from the present invention which is an object of improving the performance.
[0011]
Furthermore, in the prior example 2, it is described that a pigment / colorant may be blended, but there is no description that carbon black is used as the pigment / colorant. That is, the purpose of the present invention is clearly different from that of the present invention, which has carbon black as an essential component and has found not only an effect of improving flame retardancy (particularly, drip prevention) but also an effect of improving conductivity.
[0012]
[Problems to be solved by the invention]
In view of the background of the prior art, the present invention has high flame retardancy (particularly, droplet drop prevention during combustion), thin moldability (such as fluidity during molding), appearance quality, and high electrical conductivity. It is intended to provide a flame retardant polyamide resin composition having excellent properties and the like, and a molded product thereof.
[0013]
[Means for Solving the Problems]
  The present invention employs the following means in order to solve such problems. That is, the flame-retardant polyamide resin composition of the present invention comprises at least (A) an aliphatic polyamide resin having a sulfuric acid relative viscosity ηr in the range of 1.5 to 2.7, (B) an aromatic-containing polyamide resin, ( C) red phosphorus flame retardant, (D) metal hydroxide flame retardant, (E) carbon black, (F) carbon fiber, and (G) phenol, or a phenol derivativeTerpenesThe component (G) is contained in the range of 0.01 to 30% by weight, and flame retardancy at 1.2 mm thickness is V- in the UL-94 standard. It is characterized in that a molded product of class 0 or better can be obtained. The flame-retardant polyamide molded article of the present invention is characterized by being molded from the flame-retardant polyamide resin composition.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is earnestly related to the above-mentioned problems, that is, a flame-retardant polyamide resin composition having both high flame retardance (particularly drip prevention), thin moldability (flowability during molding, etc.), appearance quality, and high conductivity. The aromatic-containing polyamide resin which has a synergistic effect with the flame retardant of the present invention by examining and easily forming carbides during combustion, and red phosphorus which has a large flame-extinguishing effect but a small drop prevention effect (drip) during combustion -Based flame retardants, metal hydroxide flame retardants that have the effect of preventing droplets from dropping (drip) during combustion, while preventing fluidity during molding, and preventing droplets from dropping (drip) during combustion Carbon black having an effect and conductivity imparting effect, and carbon fiber having a droplet drop prevention effect, a conductivity imparting effect, and a mechanical property imparting effect (particularly rigidity) during combustion. Where I tried was the proportion of one in which the investigation to solve such a problem in one fell swoop.
[0015]
  The flame-retardant polyamide resin composition in the present invention comprises at least (A) an aliphatic polyamide resin having a sulfuric acid relative viscosity ηr of 1.5 to 2.7, (B) an aromatic-containing polyamide resin, and (C) a red phosphorus system. A flame retardant, (D) a metal hydroxide flame retardant, (E) carbon black, (F) carbon fiber, and (G) phenol, or a substituent derivative of phenolTerpenesAnd a component (G) in the range of 0.01 to 30% by weight, and UL-94 standard (US combustion test method devised by Underwriters Laboratories Inc.) In the present invention, it is characterized in that a molded article having flame retardancy at a thickness of 1.2 mm can be obtained in the V-0 class or better.
[0016]
When the flame-retardant polyamide resin composition of the present invention is 100% by weight, each component is 5 to 65% by weight of component (B), 2 to 15% by weight of component (C), and 1 to 1 of component (D). It may be within the ranges of 20% by weight, component (E) 0.5 to 10% by weight, and component (F) 5 to 35% by weight. When the amount of the component (B) is less than 5% by weight, not only the high appearance quality, which is the effect of the present invention, can be achieved, but also the synergistic effect with the flame retardant may be poor and the flame retardancy may be poor. On the other hand, when the amount is more than 65% by weight, the thin-wall moldability (fluidity during molding) is inferior, and not only the effect of the present invention is impaired, but also the mechanical strength, particularly the impact strength, may be greatly reduced. Even if the component (C) is less than 2% by weight or more than 15% by weight, high flame retardancy may not be achieved. When the component (D) is less than 1% by weight, the drip prevention effect may be inferior, and when it is more than 20% by weight, the fluidity during molding may be inferior. When the components (E) and (F) are less than the lower limit value of the above blending amount, they may be inferior in the drip prevention effect and the conductivity imparting effect. May be inferior.
[0017]
Desirably, the component (B) is 6 to 60% by weight, the component (C) is 2.5 to 12% by weight, the component (D) is 1.5 to 15% by weight, and the component (E) is 0.5 to 8%. The component (F) is in the range of 8 to 32% by weight, more preferably 7 to 55% by weight of the component (B), 3 to 10% by weight of the component (C), and the component (D ) Is 2 to 12% by weight, component (E) is 1 to 7% by weight, and component (F) is 10 to 30% by weight.
[0018]
Moreover, it is preferable that the sum total of the weight of each component of a component (C), a component (D), a component (E), and a component (F) occupies 10 to 60 weight% in the whole composition. When the amount is 10% by weight or more, the absolute amount of the flame retardant is sufficient, and higher flame retardancy can be achieved. When it is 60% by weight or less, the absolute blending amount of a flame retardant or the like is small, the fluidity during molding is improved, and the mechanical properties of the molded product are further improved. More preferably, it is in the range of 20 to 55% by weight, and still more preferably in the range of 25 to 50% by weight. It is particularly preferred that it is in the range of 30-40% by weight.
[0019]
The component (A) in the present invention is preferably an aliphatic polyamide resin having excellent fluidity at the time of molding in order to obtain a thin molded product, and having a sulfuric acid relative viscosity ηr in the range of 1.5 to 2.7. is there. More desirably, the aliphatic polyamide resin has ηr in the range of 1.8 to 2.6, and more desirably ηr in the range of 2.0 to 2.5. An aliphatic polyamide resin having an ηr in the range of 2.1 to 2.4 is particularly preferable. When ηr exceeds 2.7, the fluidity at the time of molding is inferior, and the fluidity at the time of molding, which is one effect of the present invention, is not effectively exhibited. Further, when ηr is less than 1.5, not only the mechanical properties are inferior, but also low molecular weight components are increased, so that a large amount of gas is generated at the time of molding, which may hinder thin moldability. Here, the sulfuric acid relative viscosity ηr is dissolved in 98% sulfuric acid so that the solution concentration becomes 1 g / 100 ml, and then the flow rate is measured with an Ostwald viscometer in a constant temperature bath at 25 ° C. It is represented by the viscosity ratio (flowing seconds ratio).
[0020]
The aliphatic polyamide resin used in the present invention refers to those having no aromatic ring in the molecular chain, and is a polyamide mainly composed of amino acids, lactams or diamines and dicarboxylic acids. Representative examples of the raw materials include lactams such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, ε-aminocaprolactam, and ω-laurolactam, tetramethylenediamine, hexamethylenediamine, and 2-methylpenta Methylenediamine, nonanemethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, 1,3-bis (Aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl- 4-aminocyclo Hexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine, and other aliphatic and alicyclic diamines, and adipic acid, superic acid, azelaic acid, sebacic acid In the present invention, polyamide homopolymers or copolymers derived from these raw materials can be used singly or in the form of a mixture, respectively.
[0021]
In the present invention, a particularly useful aliphatic polyamide resin is a nylon resin having a melting point of 120 ° C. or more and excellent in heat resistance and strength. Specific examples include polycaproamide (nylon 6), polyhexamethylene. Substitution of nylon 6 with methoxymethyl group such as adipamide (nylon 66), polytetramethylene adipamide (nylon 46), polyhexamethylene sebamide (nylon 610), polyhexamethylene dodecamide (nylon 612) And the like (nylon 8), resins derived therefrom, and mixtures or copolymer resins thereof.
[0022]
More useful aliphatic polyamide resins for use in the present invention include nylon 6, nylon 66, or nylon 6 / nylon 66 copolymer resin, or mixtures. More useful are nylon 6 Is mentioned. When nylon 6 is used, the thin-wall moldability (fluidity at the time of molding), which is one effect of the present invention, can be further enhanced.
[0023]
Such component (B) is an aromatic-containing polyamide resin. The aromatic-containing polyamide refers to those having an aromatic ring in a molecular chain, and generally one of raw materials such as diamine or dicarboxylic acid has an aromatic ring and the other is α, ω. -Refers to those that are straight chain aliphatic. Representative examples of the raw materials include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and paraaminomethylbenzoic acid, lactams such as ε-aminocaprolactam and ω-laurolactam, tetramethylenediamine, Hexamethylenediamine, 2-methylpentamethylenediamine, nonanemethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 5-methylnona Methylenediamine, metaxylenediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethyl Siku Fats such as rhohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine , Cycloaliphatic, aromatic diamines, and adipic acid, speric acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid Examples thereof include aliphatic, alicyclic and aromatic dicarboxylic acids such as acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid and hexahydroisophthalic acid. In the present invention, polyamide homopolymer derived from these raw materials is used. Polymers or copolymers, each alone or in the form of a mixture It can be used.
[0024]
In the present invention, a particularly useful aromatic-containing polyamide resin is a polyamide resin having a melting point of 200 ° C. or higher or a glass transition point of 60 ° C. or higher and excellent in heat resistance and strength. Specific examples include polynonane. Methylene terephthalamide (nylon 9T), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T), polyhexamethylene terephthalamide / polycaproamide copolymer (nylon 6T / 6), polyhexamethylene adipa Mido / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I), polyhexamethylene isophthalamide / polycaproamide copolymer (nylon 6I / 6), polydodecamide / polyhexamethylene terephthalamide copolymer (nylon 12 / 6T) Polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6T / 6I), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), polyhexa Examples include methylene terephthalamide / poly (2-methylpentamethylene terephthalamide) copolymer (nylon 6T / M5T), polyxylylene adipamide (nylon XD6), and mixtures or copolymer resins thereof.
[0025]
More useful examples of the aromatic-containing polyamide resin used in the present invention include nylon XD6, nylon 6T / 6I, nylon 66 / 6I, nylon 66/6/6/6 copolymer, and mixtures thereof. However, more useful examples include polymetaxylylene adipamide, which is a condensation polymer of metaxylylene amide and adipic acid, nylon 6T / 6I, nylon 66/6 / 6I, and any of these. It may be a combination. When these are used, shrinkage of the resin composition after molding is suppressed, sink marks and bulges in the weld portion can be minimized, and the appearance quality is excellent.
[0026]
As in the case of the component (A), the component (B) in the present invention should be excellent in fluidity during molding in order to obtain a thin molded product, and the sulfuric acid relative viscosity ηr is 1.5 to 2.7. It should be within the range. More preferably, ηr is in the range of 1.6 to 2.5, and more preferably ηr is in the range of 1.7 to 2.4. It is particularly preferable that ηr is in the range of 1.9 to 2.2.
[0027]
There is no particular limitation regarding the form of the mixture of component (A) and component (B), which may be compatible or may be phase-separated in a form such as a sea-island structure, but both components are compatible with each other, It is preferable that the component (A) or the component (B) does not take a phase-separated form such as a sea-island structure because the effects of the present invention are sufficiently exhibited.
[0028]
Moreover, there is no restriction | limiting in particular also about those mixing methods, Even if it only mixes using an extruder and / or a molding machine (for example, injection molding machine etc.), one side is another component (for example, component (F) etc.). Even if the other is mixed with an extruder and / or a molding machine after adhering to the other, the other is mixed with the other components (for example, components (C), (D), (E), etc.) May be mixed using an extruder / molder, but in order to sufficiently mix both components, a method of mixing both using a twin-screw extruder and further mixing using a molding machine, It is preferable to use a method in which one component is adhered to the component (F) and then mixed with the other component using a twin screw extruder and / or a molding machine.
[0029]
In addition, the component (A) and / or the component (B) includes an acid-modified olefin polymer such as maleic anhydride, an ethylene / propylene copolymer, depending on the necessity of improving characteristics (particularly impact resistance). , Ethylene / 1-butene copolymer, ethylene / propylene / non-conjugated diene copolymer, ethylene / ethyl acrylate copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / vinyl acetate / glycidyl methacrylate copolymer And an ethylene / propylene-g-maleic anhydride copolymer, an olefin copolymer such as ABS, a polyester polyether elastomer, a polyester polyester elastomer, or a mixture of two or more selected from an elastomer, A resin further imparted with desired characteristics can also be used. Furthermore, depending on the required properties such as moldability, heat resistance, and low water absorption, these copolymers and resins obtained by mixing two or more of these polyamide resins can also be used in the present invention. In addition, to improve impact resistance, etc., a resin in which an elastomer or a rubber component is added to the above resin, or a terminal group modified or sealed for compatibility control when the resin is mixed Are also included in the polyamide resin that can be used in the present invention.
[0030]
The component (C) in the present invention is a red phosphorus flame retardant. Red phosphorus is unstable as it is, and has a property of gradually dissolving in water or reacting with water. Therefore, a red phosphorus flame retardant having a treatment for preventing it is preferable. As a treatment method of such red phosphorus,
(1) A method for forming red phosphorus into fine particles as described in JP-A-5-229806 without pulverizing red phosphorus and without forming a crushing surface having high reactivity with water and oxygen on the surface of red phosphorus,
(2) A method for catalytically suppressing red phosphorus oxidation by adding a small amount of aluminum hydroxide or magnesium hydroxide to red phosphorus,
(3) A method of coating red phosphorus with paraffin or wax to suppress contact with moisture,
(4) A method of stabilizing by mixing with ε-caprolactam or trioxane,
(5) A method of stabilizing red phosphorus by coating it with a thermosetting resin such as phenol, melamine, epoxy, or unsaturated polyester,
(6) A method in which red phosphorus is treated with an aqueous solution of a metal salt such as copper, nickel, silver, iron, aluminum and titanium, and a metal phosphorus compound is deposited on the surface of red phosphorus to stabilize it.
(7) A method of coating red phosphorus with aluminum hydroxide, magnesium hydroxide, titanium hydroxide, zinc hydroxide, etc.
(8) A method of stabilizing the surface of red phosphorus by electroless plating with iron, cobalt, nickel, manganese, tin or the like.
Examples of the method are the methods (1), (5), and (7), and the methods (1) and (5) are particularly preferable. In the method (5), among the thermosetting resins, red phosphorus coated with a phenolic thermosetting resin or an epoxy thermosetting resin can be preferably used from the viewpoint of moisture resistance, and is particularly preferable. Is red phosphorus coated with a phenolic thermosetting resin.
[0031]
The average particle size of red phosphorus is in the range of 0.01 to 35 μm from the viewpoint of suppressing the chemical and physical deterioration of red phosphorus due to flame retardancy, mechanical properties, heat and humidity resistance, and pulverization during recycling. And more preferably within the range of 0.1 to 30 μm.
[0032]
The average particle size of red phosphorus can be measured with a general laser diffraction particle size distribution analyzer. The particle size distribution measuring apparatus includes a wet method and a dry method, and any of them may be used. In the case of a wet method, water can be used as a dispersion solvent for red phosphorus. At this time, the surface of red phosphorus may be treated with alcohol or a neutral detergent. Moreover, it is also possible to use phosphates, such as sodium hexametaphosphate and sodium pyrophosphate, as a dispersing agent. It is also possible to use an ultrasonic bus as a dispersing device.
[0033]
The average particle size of red phosphorus used in the present invention is as described above. Red phosphorus having a large particle size contained in red phosphorus, that is, red phosphorus having a particle size of 75 μm or more is flame retardant. In order to remarkably reduce mechanical properties, heat-and-moisture resistance, and recyclability, red phosphorus having a particle size of 75 μm or more is preferably removed by classification or the like. The content of red phosphorus having a particle size of 75 μm or more is preferably 10% by weight or less, more preferably 8% by weight or less, and particularly preferably 5% by weight or less from the viewpoints of flame retardancy, mechanical properties, heat and humidity resistance, and recyclability. It is. Although there is no restriction | limiting in particular in a minimum, It is so preferable that it is close to 0.
[0034]
Here, the content of red phosphorus having a particle size of 75 μm contained in red phosphorus can be measured by classification using a 75 μm mesh. That is, the content of red phosphorus having a particle size of 75 μm or more can be calculated from Z / 100 × 100 (%) from the residual amount Z (g) when 100 g of red phosphorus is classified with a 75 μm mesh.
[0035]
Further, the conductivity of red phosphorus used in the present invention when extracted in hot water (where the conductivity is 100 g of pure water added to 5 g of red phosphorus and extracted at 121 ° C. for 100 hours, for example, in an autoclave. The conductivity of the extracted water obtained by diluting the filtrate after red phosphorus filtration to 250 mL is measured from the viewpoint of the moisture resistance, mechanical strength, tracking resistance, and surface properties of the obtained molded product. It is in the range of 1 to 1000 μS / cm, preferably 0.1 to 800 μS / cm, more preferably 0.1 to 500 μS / cm.
[0036]
Also, the amount of phosphine generated in red phosphorus used in the present invention (here, the amount of phosphine generated is put in a container such as a test tube having an internal volume of 500 mL in which 5 g of red phosphorus is replaced with nitrogen, and after reducing the pressure to 10 mmHg, After heat treatment for 10 minutes, cooling to 25 ° C., diluting the gas in the test tube with nitrogen gas and returning to 760 mmHg, measurement is performed using a phosphine (hydrogen phosphide) detector tube, and the following formula is used. Generated amount (ppm) = detection tube indication value (ppm) × dilution ratio) is the amount of gas generated in the resulting composition, extrusion, stability during molding, mechanical strength during melt residence, surface appearance of the molded product, From the standpoint of terminal corrosion due to the molded product, those of 100 ppm or less are usually used, preferably 50 ppm or less, more preferably 20 ppm or less.
[0037]
Preferable commercial products of red phosphorus include “Nova Excel” 140, “Nova Excel” F5 manufactured by Rin Kagaku Kogyo, and equivalents thereof.
[0038]
Component (D) in the present invention is a metal hydroxide flame retardant. The metal hydroxide flame retardant used in the present invention is a hydroxide composed of a Group II metal such as magnesium, calcium, barium, and zinc, and a Group III metal such as aluminum. For example, magnesium hydroxide , Calcium hydroxide, barium hydroxide, zinc hydroxide, aluminum hydroxide and the like. These may be used alone or in combination. The metal hydroxide flame retardant used in the present invention is preferably magnesium hydroxide having excellent heat resistance.
[0039]
Magnesium hydroxide used in the present invention may be a natural type or a synthetic type, but preferably has a small average crystal grain size distribution range and is contained in component (A) and / or component (B). A synthetic type having excellent dispersibility is preferred. The average crystal grain size of magnesium hydroxide is preferably in the range of 0.2 to 50 μm from the viewpoint of suppressing deterioration of mechanical properties. More preferably, it exists in the range of 0.5-10 micrometers, More preferably, it exists in the range of 0.7-5 micrometers. When the average crystal grain size is less than 0.2 μm, there may be a problem in the manufacturing process such as poor feedability to the extruder when compounding with the polyamide resin. Moreover, when exceeding 50 micrometers, the problem that it is inferior to the dispersibility in a component (A) and / or a component (B), and is inferior to a flame retardance may arise.
[0040]
The shape of the primary crystal particles of magnesium hydroxide may be either a hexagonal plate shape, a needle shape, or a mixture thereof. In this case, the aspect ratio of the primary crystal grains is preferably 200 or less. When the aspect ratio exceeds 200, in general, the impact strength may be particularly lowered. Further, in order to have excellent fluidity at the time of molding, the shape of the primary crystal particles is preferably a hexagonal plate shape, particularly a shape close to a sphere with a developed c-axis. In this case, the aspect ratio of the primary crystal particles is 100 or less.
[0041]
Magnesium hydroxide used in the present invention may be surface-treated with a known surface treating agent or may be untreated. Examples of the surface treatment agent include saturated higher fatty acids such as stearic acid, unsaturated higher fatty acids such as oleic acid, alkali metal salts thereof, mono- or diesters of orthophosphoric acid and stearyl alcohol, and their acids, or Examples include phosphoric acid partial esters such as alkali metal salts. Moreover, in order to improve thermal stability, it may be coated with a thermosetting resin such as phenol, melamine, epoxy, or unsaturated polyester, and adheres to component (A) and / or component (B). In order to improve the properties, it may be coated with a highly polar resin such as a silane coupling agent, an aluminate coupling agent, a titanate coupling agent, a urethane type or an amide type. Alternatively, in order to suppress the surface whitening phenomenon of the molded product and further improve the acid resistance and flame retardancy, a metal element may be dissolved in the surface. Examples of the metal element include nickel and zinc. More preferably, the surface treatment is performed with a surface treatment agent that does not cause a chemical reaction with component (A) and / or component (B) during molding. When surface treatment that causes a chemical reaction is performed, the fluidity at the time of molding is inferior, and the effects of the present invention cannot be sufficiently exhibited. The surface treatment amount of the surface treatment agent is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight per 100 parts by weight of magnesium hydroxide.
[0042]
As a preferable commercial product of magnesium hydroxide, "Kisuma 5A, 5B, 5E, 5J, 5NH, 5PH" powder or granular product manufactured by Kyowa Chemical Industry Co., Ltd., "Fine Mag SN-T, L", "Echo Mug" manufactured by TMG Z10 "," Magsees N-0, N-1, N-3, N-4, N-10 "manufactured by Kamishima Chemical Co., Ltd.," KMH "manufactured by Kinsei Tech Co., etc., and their equivalents are listed. It is done.
[0043]
The component (E) in the present invention is carbon black. Examples of the carbon black used in the present invention include furnace black (produced by burning raw oil in a high temperature furnace), acetylene black (produced by exothermic decomposition of acetylene gas), thermal black, channel black, and the like. Carbon black blended in two or more types may be used.
[0044]
  Used in the present inventionpreferableCarbon blackAsIs Raman shift 1360cm^-1The maximum of the Raman band that appears in the vicinity I₁And Raman shift 1480cm^-1The local minimum I of the Raman band that appears in the vicinity₂Raman scattering intensity ratio I₂/ I₁Carbon black in the range of 0.4 to 0.8As an example.
[0045]
In general, basic characteristics such as dispersibility of carbon black greatly vary depending on the production conditions, and the production conditions greatly affect the crystal structure of carbon black. Carbon black, which is a carbon material, can be estimated for its crystal structure (graphite structure here) by measuring Raman spectra. That is, it can be said that the basic characteristics of carbon black can be easily grasped only by measuring the Raman spectrum.
[0046]
  That is, the carbon black in the present invention has the maximum value I of the Raman band of the Raman spectrum.₁And the Raman band minimum I₂Raman scattering intensity ratio I₂/ I₁Is selected within a specific range of 0.4 to 0.8 and usedIs preferable.
[0047]
Where I₂/ I₁Is for the scattering intensity of the Raman band after baseline correction. The above baseline correction is 600 cm.^-1~ 2200cm^-1In the Raman shift range, the Raman spectrum base line is linearly approximated, the distance from the approximate line is regarded as the Raman scattering intensity, and the baseline tilt at the time of measurement is corrected. In addition, I mentioned later₂/ I_ThreeAlso, all are for the scattering intensity of the Raman band after baseline correction.
[0048]
The present invention provides a flame retardant polyamide resin composition that has both specifically high conductivity, thin-wall formability (particularly fluidity during molding), and appearance quality when carbon black having such a specific configuration is used. Can be provided. That is, in the present invention, in the case of carbon black having a specific Raman spectrum, it is possible to achieve an excellent effect of simultaneously satisfying the above high conductivity, thin-wall formability, and appearance quality. The selection by the Raman spectrum is very significant from an industrial point of view because it can be selected easily and accurately without measuring various characteristics of carbon black.
[0049]
  One such carbon black isChoiceThe requirement is I₂/ I₁However, it is preferable to select and use carbon black in the range of 0.4 to 0.8, preferably 0.50 to 0.77, and more preferably 0.65 to 0.75. Particularly desirable is in the range of 0.66 to 0.71. That is, this I₂/ I₁However, when carbon black outside the range of 0.4 to 0.8 is used, high conductivity can be achieved, but the thin-wall formability (fluidity during molding) and the appearance quality are significantly inferior. Therefore, it is difficult to obtain a flame-retardant polyamide resin composition having both conductivity, thin-wall moldability, and appearance quality. That is, I₂/ I₁In the case of carbon black having an A of less than 0.4, the fluidity at the time of molding may be greatly inferior apart from the conductivity.
[0050]
Another method for selecting the carbon black of the present invention is a Raman shift of 1480 cm.^-1The local minimum I of the Raman band that appears in the vicinity₂And Raman shift 1580cm^-1The maximum of the Raman band that appears in the vicinity I_ThreeRaman scattering intensity ratio I₂/ I_ThreeHowever, it is preferable to select and use carbon black within the range of 0.4 to 0.7, preferably 0.50 to 0.67, and more preferably 0.56 to 0.65. Particularly desirable is in the range of 0.57 to 0.61.
[0051]
Such carbon black, ie I₂/ I_ThreeHowever, the effective difference between the carbon black within the range of 0.4 to 0.7 and the carbon black outside the range is the same as that selected by the above method, Although high electrical conductivity can be achieved, the fluidity during molding may be extremely inferior, and it is difficult to obtain a flame-retardant polyamide resin composition having both electrical conductivity and thin moldability. In terms of fluidity, it is possible to select a carbon black that exhibits a severe fluidity property in that it exhibits low fluidity when out of the range as compared to those within the range.
[0052]
In the present invention, as a more desirable carbon black than the above component (E),₂/ I₁Is in the range of 0.4 to 0.8, and I₂/ I_ThreeHowever, carbon black within the range of 0.4 to 0.7 can reliably provide a flame retardant polyamide resin composition having both excellent electrical conductivity and high thin moldability. When carbon black selected by this selection method is used, it is indicated by the same fluidity difference as compared with the one selected by the method described above, and it is difficult to satisfy the problems of the present invention. There is an advantage that a flammable polyamide resin composition can be provided.
[0053]
The Raman spectrum is measured by laser Raman spectroscopy. The Raman spectrum may be measured from carbon black before blending with the resin, or may be measured after separating the carbon black from the polyamide resin composition or the molded product thereof. When measuring from the former, it is preferable to perform measurement with macro-Raman (laser spot diameter of about 100 μm), and when measuring from the latter, measurement with micro-Raman (laser spot diameter of about 5 μm). In the present invention, measurement was performed using a Ramaonor T-64000 manufactured by JobinYvon.
[0054]
The separation of the carbon black from the resin molded article is preferably performed by utilizing the difference in specific gravity of the blend. An example of specific means for such a carbon black separation method will be described below.
[0055]
First, the polyamide resin molded product is immersed in a solvent that dissolves the resin without attacking the carbon black to completely dissolve the resin. Thereafter, centrifugation is performed at 5000 rpm for 30 minutes, and the supernatant after centrifugation is further subjected to ultracentrifugation at 30000 rpm for 30 minutes. The supernatant liquid after ultracentrifugation is filtered through a PTFE filter (0.2 μm) to separate carbon black. In this case, the measurement of the Raman spectrum is preferably performed on the black fine particle portion in the recovered material obtained by the above-described separation using microscopic Raman.
[0056]
The component (F) in the present invention is a carbon fiber such as PAN, pitch, or rayon. Also, metal-coated carbon fibers obtained by coating carbon fibers with metals such as nickel and copper can be used in the present invention. The average fiber diameter of the component (F) is preferably 1 to 20 μm, more preferably 2 to 12 μm, and still more preferably 3 to 10 μm. When the average fiber diameter is less than 1 μm, impregnation of the component (A) and / or the component (B) into the component (F) bundle becomes difficult, and the dispersibility of the component (F) in the molded product is poor. Cause problems. On the other hand, if the average fiber diameter exceeds 20 μm, carbon fibers having excellent mechanical properties cannot be obtained, and a desired reinforcing effect cannot be obtained.
[0057]
The carbon fiber used in the present invention preferably has a crystal size (hereinafter referred to as Lc) measured by a wide angle X-ray diffraction method within a range of 1 to 4 nm. When Lc is less than 1 nm, carbon fiber is not sufficiently carbonized, and the conductivity of the carbon fiber itself is lowered. This is not preferable because the resulting molded product may have poor conductivity. On the other hand, when Lc exceeds 4 nm, the carbon fiber is sufficiently carbonized and graphitized, and the carbon fiber itself is excellent in conductivity, but on the other hand, it becomes brittle. This is not preferable because the fiber length in the molded product is shortened and high conductivity cannot be expected. More preferably, it exists in the range of 1.3-3.5 nm, More preferably, it exists in the range of 1.6-3 nm. Particularly preferred are those in the range of 1.8 to 2.5 nm. In addition, the measurement of Lc by a wide angle X-ray diffraction method was measured by the method described in Japan Society for the Promotion of Science 117th committee, carbon, 36, p25 (1963).
[0058]
The carbon fiber used in the present invention has a surface functional group amount (O / C) which is the ratio of the number of oxygen (O) and carbon (C) atoms on the surface of the carbon fiber measured by X-ray photoelectron spectroscopy. Those within the range of .05 to 0.4 are desirable. When O / C is smaller than 0.05, it means that there are very few functional groups that contribute to adhesion to the resin on the surface of carbon fiber. If the adhesion between the carbon fiber and the resin is poor, high mechanical properties cannot be expected for the molded product. Conversely, if O / C is larger than 0.4, the carbon fiber surface is oxidized or alkalinized more than necessary, and the crystal structure of carbon is destroyed and a fragile layer is formed on the carbon fiber surface. It means that In this case as well, as in the case where O / C is too low, breakage is likely to occur in the vicinity of the fiber surface layer, so high mechanical properties cannot be expected for the molded product. Furthermore, making O / C within the range of 0.05 to 0.4 brings about preferable effects other than the adhesion between the carbon fiber and the resin, such as the dispersibility of the carbon fiber in the molded product.
[0059]
The surface functional group (O / C) is determined by the following procedure by X-ray photoelectron spectroscopy. First, after cutting carbon fiber or carbon fiber bundle from which resin such as sizing agent is removed with a solvent and spreading it on a copper sample support base, the photoemission angle is set to 90 degrees, and the X-ray source MgKα1 and 2 are used as the sample chamber and 1 × 10^-8Keep at Torr. C as a peak correction due to charging during measurement_1SThe kinetic energy value (KE) of the main peak is adjusted to 969 eV. C_1SThe peak area is K.K. E. Is obtained by drawing a straight base line within a range of 958 to 972 eV. O_1SThe peak area is K.K. E. It is obtained by drawing a straight base line within the range of 714 to 726 eV. Here, the surface functional group amount (O / C) is the O_1SPeak area and C_1SThe atomic ratio is calculated from the peak area ratio using the sensitivity correction value unique to the apparatus.
[0060]
Desirably, the carbon fiber used in the present invention is a carbon fiber having a tensile elongation at break of at least 1.5%. If the tensile elongation at break is less than 1.5%, the fiber is easily cut in the molding process, and the fiber length in the resin composition and the molded product cannot be increased. Impact strength) cannot be achieved. In order to impart high mechanical properties, the tensile breaking elongation is 1.5% or more, more desirably, the tensile breaking elongation is 1.7% or more, and further desirably, the tensile breaking elongation is 1.9% or more. Carbon fiber should be used. There is no upper limit to the tensile elongation at break of the carbon fiber used in the present invention, but it is generally less than 5%. More preferably, the carbon fiber is a PAN-based carbon fiber that has an excellent balance between strength and elastic modulus.
[0061]
The carbon fibers used in the present invention are coupling agents such as silane coupling agents, aluminate coupling agents, titanate coupling agents, acrylic resins, vinyl resins, urethane resins, epoxy resins, ester resins. Further, surface treatment may be performed with a styrene resin, an olefin resin, an amide resin, a phenol resin, a liquid crystal resin, or the like.
[0062]
Typical examples of such amide resins include water-soluble polyamides, alcohol-soluble polyamides, and the like. Particularly, polyamide resins that do not contain aromatics in the molecular chain, that is, components (A) of aliphatic polyamide resins. It is preferable.
[0063]
A typical example of such a water-soluble polyamide is a polyamide resin containing an alkylene oxide chain in the molecular chain. Examples of the alcohol-soluble polyamide include nylon 6/66/610, nylon 6/66/612, nylon 6/66/610/12 copolymer, and nylon 8 in which hydrogen in the amide group is substituted with a methoxymethyl group. As typical examples, nylon 6/66/612, nylon 6/66/610/12 copolymer, and nylon 8, which are excellent in solution stability when dissolved in alcohol, are preferable. In addition, as alcohol here, methanol, ethanol, (iso) propanol, (iso) butanol etc. are mentioned as a typical example, for example, those mixtures, a mixture with other organic solvents, those, water, and A mixture of
[0064]
  The flame retardant polyamide resin composition of the present invention further comprises phenol as a component (G) or a phenol derivative (precursor a).TerpenesIt is necessary to contain a phenolic resin obtained by the condensation reaction of (precursor b). Particularly, by mixing the polyamide resin, particularly nylon 6 and the component (G), the fluidity at the time of molding, which is one effect of the present invention, can be expressed more highly. Such component (G) is, for example, phenol aralkyl., TeExamples include rupened modified phenol and terpene / phenol copolymer resin. In addition, phenol or a substituent derivative of phenol (precursor a),TerpenesThe condensation reaction of (precursor b) can be performed in the presence of a strong acid or a Lewis acid. The component (G) can also be obtained by reacting the precursor a and a compound that generates the precursor b in the system under the same conditions.
[0065]
As this precursor a, what has 1-3 substituents chosen from an alkyl group, a halogen atom, and a hydroxyl group on the benzene nucleus of phenol is used preferably. Specific examples include cresol, xylenol, ethylphenol, butylphenol, t-butylphenol, nonylphenol, 3,4,5-trimethylphenol, chlorophenol, bromophenol, chlorocresol, hydroquinone, resorcinol, orcinol. A plurality of these may be used. Particularly preferred are phenol and cresol.
[0066]
  The precursor b may or may not have a cyclic structure.. ringAs a compound having a structure, a monocyclic compound, C _TenH₁₆Bicyclic compounds such as monocyclic monoterpenes (dipentene, limonene, terpinolene, terpinene, ferrandrene) represented by the molecular formula, C ₁₅H_{twenty four}Bicyclic sesquiterpenes (kadinene, serinene, caryophyllene) represented by the molecular formulaWhichA plurality of these may be used. As the precursor b,,ringThose having a shape structure are preferred. Those having a cyclic structure have a relatively rigid molecular chain, which advantageously contributes to mechanical properties. Particularly preferred is C_TenH₁₆Monocyclic monoterpene represented by the molecular formulaIsCan be mentioned.
[0067]
Examples of the compound that generates the precursor b in the system include pinene and camphene that generate dipentene by isomerization, and a plurality of these may be used.
[0068]
Particularly excellent components (G) of the present invention include those having a relatively high polarity obtained by adding one molecule of precursor b to two molecules of precursor a, and phenol aralkyl. In particular, when mixed with a polyamide resin, particularly nylon 6, it is preferable because of its excellent affinity.
[0069]
These components (G) preferably have a weight average molecular weight of 200 or more and 5000 or less. If the molecular weight is less than 200, the thermal stability is inferior, so that it volatilizes during molding and causes defects such as voids in the molded product. On the other hand, if the molecular weight exceeds 5000, the thin-wall moldability (fluidity at the time of molding) is inferior, and the effects of the present invention cannot be sufficiently exhibited, which is not preferable. Here, the weight average molecular weight was measured using a gel permeation chromatography (GPC) and using a low angle light scattering photometer (LALLS) using a laser as a detector.
[0070]
  The compounding ratio of the component (G) used in the present invention is 0.01 to 30% by weight when the total amount of the flame retardant polyamide resin composition is 100% by weight.Must be and goodIt is preferably 0.1 to 20% by weight, more preferably 1.0 to 10% by weight. When the blending ratio of the component (G) is too small or too much beyond the range, the balance of mechanical properties such as flame retardancy, moldability, impact resistance, and strength in a thin molded product is achieved. Since a material cannot be obtained, it is not preferable.
[0071]
Similarly, even when a polyamide resin, particularly an aromatic-containing polyamide resin and a component (H) are mixed, the thin-wall formability (fluidity during molding), which is one effect of the present invention, can be expressed more highly. wear. Such a component (H) is a liquid crystalline resin and refers to a resin that can form anisotropy when melted. Examples of the liquid crystalline resin include liquid crystal polyester, liquid crystal polyester amide, liquid crystal polycarbonate, and liquid crystal polyester elastomer. Among them, those having an ester bond in the molecular chain are preferable, and liquid crystal polyester, liquid crystal polyester amide, and the like are particularly preferable. Used. However, when mixing liquid crystalline resin, it is preferable to seal the terminal group (especially amide group) of a polyamide resin with an acid anhydride etc., for example.
[0072]
The liquid crystalline resin that can be preferably used in the present invention is a liquid crystalline polyester containing a structural unit composed of p-hydroxybenzoic acid as an aromatic oxycarbonyl unit, and a liquid crystalline polyester having an ethylenedioxy unit as an essential component is also preferably used. it can. More preferably, it is a polyester comprising the following structural units (I), (III), (IV) or a polyester comprising the structural units (I), (II), (III), (IV), most preferably ( A polyester comprising structural units of I), (II), (III) and (IV).
[0073]
[Chemical 1]

[0074]
(However, R in the formula₁Is
[0075]
[Chemical 2]

[0076]
One or more groups selected from (a) to (j), and R₂Is
[0077]
[Chemical Formula 3]

[0078]
1 type or more group chosen from (A)-(F). In the formula, X represents a hydrogen atom or a chlorine atom. )
The total of the structural units (II) and (III) and the structural unit (IV) are preferably substantially equimolar.
[0079]
The structural unit (I) is a structural unit formed from p-hydroxybenzoic acid, and the structural unit (II) is 4,4′-dihydroxybiphenyl, 3,3 ′, 5,5′-tetramethyl-4,4. '-Dihydroxybiphenyl, hydroquinone, t-butylhydroquinone, phenylhydroquinone, methylhydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,2-bis (4-hydroxyphenyl) propane and 4,4'- A structural unit generated from one or more aromatic dihydroxy compounds selected from dihydroxydiphenyl ether, a structural unit (III) is a structural unit generated from ethylene glycol, a structural unit (IV) is terephthalic acid, isophthalic acid, 4, 4 '-Diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bis One or more aromatics selected from phenoxy) ethane-4,4′-dicarboxylic acid, 1,2-bis (2-chlorophenoxy) ethane-4,4′-dicarboxylic acid and 4,4′-diphenyl ether dicarboxylic acid Each of the structural units generated from dicarboxylic acid is shown. R of these₁But
[0080]
[Formula 4]

[0081]
And R₂But
[0082]
[Chemical formula 5]

[0083]
Are particularly preferred.
[0084]
The copolymerization amount of the structural units (I), (II), (III) and (IV) is arbitrary. However, in order to exhibit the characteristics of the present invention, the following copolymerization amount is preferable.
[0085]
That is, in the case of a copolymer consisting of the structural units (I), (II), (III), (IV), the sum of the structural units (I) and (II) is the structural units (I), (II ) And (III) is preferably 30 to 95 mol%, more preferably 40 to 93 mol%. The structural unit (III) is preferably 70 to 5 mol%, more preferably 60 to 7 mol%, based on the total of the structural units (I), (II) and (III). The molar ratio [(I) / (II)] between the structural units (I) and (II) is preferably 75/25 to 95/5, more preferably 78/22 to 93/7. The structural unit (IV) is preferably substantially equimolar to the total of the structural units (II) and (III).
[0086]
On the other hand, when the structural unit (II) is not included, the structural unit (I) is preferably 40 to 90 mol% based on the total of the structural units (I) and (III) from the viewpoint of fluidity. It is particularly preferably 60 to 88 mol%, and the structural unit (IV) is preferably substantially equimolar to the structural unit (III).
[0087]
The liquid crystalline polyesteramide is preferably a polyesteramide that forms an anisotropic molten phase containing a p-iminophenoxy unit generated from p-aminophenol in addition to the structural units (I) to (IV).
[0088]
The liquid crystalline polyester and liquid crystalline polyester amide that can be preferably used include 3,3′-diphenyldicarboxylic acid and 2,2′-diphenyldicarboxylic acid in addition to the components constituting the structural units (I) to (IV). Aromatic dicarboxylic acids such as acids, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid and dodecanedioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, chlorohydroquinone, 3,4'-dihydroxybiphenyl, Aromatic diols such as 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxybenzophenone, 3,4′-dihydroxybiphenyl, propylene glycol, 1,4-butanediol, 1 , 6-hexanediol, neopentylglyce Cole, aliphatic such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, alicyclic diol and aromatic hydroxycarboxylic acid such as m-hydroxybenzoic acid, 2,6-hydroxynaphthoic acid and p-amino Benzoic acid and the like can be further copolymerized within a range not impairing liquid crystallinity.
[0089]
The liquid crystalline resin used in the present invention can measure the logarithmic viscosity in pentafluorophenol. In that case, 0.5-15.0 dl / g is preferable at the value measured at 60 degreeC by the density | concentration of 0.1 g / dl, and 1.0-3.0 dl / g is especially preferable.
[0090]
The melt viscosity of the liquid crystalline resin in the present invention is preferably 0.5 to 500 Pa · s, more preferably 1 to 250 Pa · s. Moreover, when it is going to obtain the composition excellent in fluidity | liquidity, it is preferable that melt viscosity shall be 50 Pa.s or less.
[0091]
The melt viscosity is a value measured by a Koka flow tester under the condition of melting point (Tm) + 10 ° C. and shear rate of 1,000 (1 / second).
[0092]
Here, the melting point (Tm) is the Tm1 +20 after the observation of the endothermic peak temperature (Tm1) observed when the polymer having been polymerized is measured from room temperature under a temperature rising condition of 20 ° C./min in differential calorimetry. This is the endothermic peak temperature (Tm2) observed when the temperature is kept at a temperature of 5 ° C. for 5 minutes, then cooled to room temperature under a temperature drop condition of 20 ° C./minute, and then measured again under a temperature rise condition of 20 ° C./minute. .
[0093]
The melting point of the liquid crystalline resin is not particularly limited, but is preferably 340 ° C. or lower, more preferably 330 ° C. or lower from the viewpoint of dispersibility in the polyamide resin.
[0094]
There is no restriction | limiting in particular in the manufacturing method of the said liquid crystalline polyester used in this invention, It can manufacture according to the well-known polyester polycondensation method.
[0095]
For example, in the production of the liquid crystal polyester, the following production method is preferably exemplified.
(1) Diacylated products of p-acetoxybenzoic acid and aromatic dihydroxy compounds such as 4,4′-diacetoxybiphenyl and diacetoxybenzene, and aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid, terephthalic acid and isophthalic acid The method of manufacturing from a deacetic acid condensation polymerization reaction.
(2) Reacting p-hydroxybenzoic acid and aromatic dihydroxy compounds such as 4,4′-dihydroxybiphenyl and hydroquinone with aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid, terephthalic acid and isophthalic acid with acetic anhydride. The method of producing by deacetic acid polycondensation reaction after acylating a phenolic hydroxyl group.
(3) Phenyl ester of p-hydroxybenzoic acid and aromatic dihydroxy compounds such as 4,4′-dihydroxybiphenyl and hydroquinone and diphenyl esters of aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid, terephthalic acid and isophthalic acid A method of producing from a phenol decondensation polycondensation reaction.
(4) After reacting p-hydroxybenzoic acid and aromatic dicarboxylic acid such as 2,6-naphthalenedicarboxylic acid, terephthalic acid, isophthalic acid and the like with a predetermined amount of diphenyl carbonate to obtain diphenyl ester, 4,4 ′ -A method of adding an aromatic dihydroxy compound such as dihydroxybiphenyl or hydroquinone and producing it by dephenol polycondensation reaction.
(5) Manufactured by the method (1) or (2) in the presence of a polyester polymer such as polyethylene terephthalate, an oligomer, or a bis (β-hydroxyethyl) ester of an aromatic dicarboxylic acid such as bis (β-hydroxyethyl) terephthalate. how to.
[0096]
The polycondensation reaction of the liquid crystalline polyester proceeds even without a catalyst, but metal compounds such as stannous acetate, tetrabutyl titanate, potassium acetate and sodium acetate, antimony trioxide, and magnesium metal can also be used.
[0097]
The blending ratio of the liquid crystalline resin used in the present invention is preferably 0.1 to 15% by weight, more preferably 0.5 to 10% by weight, when the total amount of the flame retardant polyamide resin composition is 100% by weight. Preferably it is 0.8 to 8 weight%. When the blending ratio of the component (H) is too small or too large beyond this range, a material with good mechanical properties such as good flow, thin-wall flame retardancy and impact resistance cannot be obtained. Absent.
[0098]
The flame-retardant polyamide resin composition of the present invention can be used to prevent drops from dropping (drip) during combustion, and to impart higher flammability using phenolic resins, silicone resins, and fluorine resins. it can. The anti-drip agent is preferably 0.01 to 30% by weight, more preferably 0.05 to 25% by weight, still more preferably 0.1 to 0.1% by weight when the total amount of the flame retardant polyamide resin composition is 100% by weight. It is recommended to blend 20% by weight.
[0099]
In particular, since the fluororesin preferably exhibits its drip prevention effect, the flame retardant polyamide resin composition of the present invention may further contain a fluororesin as the component (I). Examples of the fluororesin include polytetrafluoroethylene, polyhexafluoropropylene, (tetrafluoroethylene / hexafluoropolypropylene) copolymer, (tetrafluoroethylene / perfluoroalkyl vinyl ether) copolymer, and (tetrafluoroethylene / ethylene). ) Copolymer, (hexafluoropolypropylene / propylene) copolymer, polyvinylidene fluoride, (vinylidene fluoride / ethylene) copolymer, etc., among which polytetrafluoroethylene, (tetrafluoroethylene / ethylene) ) A copolymer is preferred. When the fluororesin is used, it is added in an amount of 0.05 to 10% by weight, preferably 0.1 to 3% by weight.
[0100]
The flame retardant polyamide resin composition of the present invention may further contain a metal oxide as the component (J). By adding a metal oxide, it is possible to improve extrudability, stability and strength during molding, heat resistance, terminal corrosivity of a molded product, and the like. Examples of such metal oxides include cadmium oxide, zinc oxide, cuprous oxide, cupric oxide, ferrous oxide, ferric oxide, cobalt oxide, manganese oxide, molybdenum oxide, tin oxide, and titanium oxide. Among them, metal oxides other than Group I and / or Group II metals such as cadmium oxide, cuprous oxide, cupric oxide, and titanium oxide are preferable, and cuprous oxide and cupric oxide are particularly preferable. Copper and titanium oxide are preferable, but metal oxides of Group I and / or Group II may be used. In addition to extrudability, stability and strength during molding, heat resistance, and terminal corrosivity of the molded product, titanium oxide is most preferable in order to further improve non-coloring properties.
[0101]
The addition amount of the metal oxide is preferably 0.01 to 20 parts by weight, particularly preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the polyamide resin in terms of mechanical properties and moldability. However, from the viewpoint of mechanical properties and specific gravity, it is preferably 0.01 to 10% by weight, particularly preferably 0.05 to 8% by weight, based on the total composition.
[0102]
In addition to the components described above, the resin composition of the present invention may further include a filler, a conductivity-imparting material, a flame retardant (for example, halogen-based, phosphorus-based, organic acid metal salt-based (for example, organic sulfone). Acid metal salts, carboxylic acid metal salts, aromatic sulfonimide metal salts, etc.), inorganic (for example, zinc borate, zinc, zinc oxide, zirconium compounds, etc.), nitrogen (nitrogenated guanidine), fluorine, silicone, etc. ), Flame retardant aids (eg cadmium oxide, zinc oxide, cuprous oxide, cupric oxide, ferrous oxide, ferric oxide, cobalt oxide, manganese oxide, molybdenum oxide, tin oxide and titanium oxide) , Pigments, dyes, lubricants, mold release agents, compatibilizers, dispersants, crystal nucleating agents (eg, mica, talc, kaolin), plasticizers (eg, phosphate esters), heat stabilizers, antioxidants, coloring Prevention Agents, ultraviolet absorbers, fluidity modifiers, foaming agents, antibacterial agents, vibration control agents, deodorants, slidability modifiers, conductivity imparting agents, antistatic agents (eg, polyether ester amides), etc. Arbitrary additives can be used alone or in a blend of two or more.
[0103]
Filler as used herein refers to mechanical properties (for example, tensile strength, elastic modulus, elongation, impact strength, linear expansion coefficient, thermal deformation temperature, etc.), thermal characteristics (for example, thermal expansion coefficient, thermal conductivity, etc.), Resin composition of the present invention such as control of molding processability (for example, screwing, viscosity, filling degree, molding shrinkage, burrs, sink marks, surface smoothness, etc.), specific gravity, anisotropy, etc., and cost reduction Is added in order to impart an effect depending on the application. Examples of such fillers include mica, talc, kaolin, sericite, bentonite, zonotolite, sepiolite, smectite, montmorillonite, wollastonite, silica, calcium carbonate, glass fiber, glass beads, glass flake, glass microballoon, clay, Molybdenum disulfide, titanium oxide, zinc oxide, antimony oxide, calcium polyphosphate, graphite, barium sulfate, magnesium sulfate, zinc borate, calcium borate, aluminum borate whisker, potassium titanate whisker, polymer, and the like can be used. These fillers may be used alone or as a blend of two or more. The shape of the filler may be any shape such as particulate (solid, hollow), powder, scale, flake, balloon, whisker (two-dimensional, three-dimensional), and fibrous depending on the purpose. You can choose. The filler may be a natural type or a synthetic type, and can be arbitrarily selected according to the purpose. Glass fiber, wollastonite, montmorillonite, titanium oxide, and potassium titanate are preferred from the balance of dispersibility in the resin, mechanical properties, cost, conductivity, and the like. In particular, when glass fiber is used, it may be blended with continuous yarn, blended with continuous fiber, cut after cutting, or blended with discontinuous yarn. It is preferable.
[0104]
In addition, the conductivity imparting material here refers to a material having conductivity, for example, metal (for example, particulate, flake, ribbon, etc.), metal oxide (for example, particulate), carbon ( For example, powder, etc.), graphite (eg, scaly, expanded particles, fine powder, etc.) itself, a conductive filler, or a non-conductive filler coated with a conductor, conductive May be used alone or in combination of two or more. Examples of the conductor covered with the filler include those having conductivity, such as metals, metal oxides, and carbon. Among these, metals having the highest conductivity are preferable. As the metal, for example, nickel, titanium, aluminum, chromium, zinc, antimony, copper, silver, gold or the like can be used alone or in combination, and the metal has at least one layer, and if necessary, a filler in multiple layers It is preferable to be coated. There is no particular limitation on the method of coating the conductor on the filler, but it is preferably coated with high adhesion strength by electrolysis or electroless plating, ion plating, CVD, PVD, vapor deposition, or the like. It is preferable.
[0105]
Moreover, it is preferable that the average particle diameter of the electroconductivity imparting material used by this invention exists in the range of 0.5-500 micrometers. More preferably, it exists in the range of 1-100 micrometers, More preferably, it exists in the range of 1.5-50 micrometers. In particular, it is preferably in the range of 2 to 25 μm. If the average particle size is less than 0.5 μm, the dispersibility in the molded product tends to be inferior, the fluidity at the time of molding is lowered, and problems such as inferior thin moldability occur, which is not preferable. On the other hand, if the average particle size exceeds 500 μm, the conductivity imparting effect is inferior, and the desired conductivity imparting effect cannot be obtained.
[0106]
The conductivity-imparting material used in the present invention is preferably selected from metals, metal oxides, and graphite because it preferably has a high conductivity in order to exhibit a higher conductivity-imparting effect. It is preferable that there is at least one kind.
[0107]
Examples of such metals include nickel, titanium, aluminum, chromium, iron, stainless steel, aluminum, tin, lead, antimony, zinc, cadmium, magnesium, tungsten, lithium, molybdenum, beryllium, cobalt, vanadium, manganese, antimony, copper, Examples include brass, silver, gold, platinum, and combinations of two or more of these, alloys based on these, compounds of these and phosphorus, and these can be used alone or in combination of two or more. You may use together. Among these, silver, nickel, and titanium are preferable because they have a large conductivity imparting effect.
[0108]
Further, the metal can take any form such as a particulate form, a flake form, and a ribbon form, but is preferably in a particulate form and / or a flake form from the viewpoint of conductivity imparting effect. In particular, when it is in the form of particles, it can take any shape such as spherical powder, granular powder, dendritic powder, flake powder, horny powder, spongy powder, irregular powder, among them dendritic powder, Flaky powder and square powder are preferable because they are excellent in conductivity imparting effect and processing cost suppressing effect.
[0109]
Examples of such metal oxides include ITO (isodium tin oxide), ATO (antimony tin oxide), and titanium oxide. These may be used alone or in combination of two or more. Good.
[0110]
Such graphite can take any form such as flaky, expanded particles and fine powder, but is preferably flaky and fine powder from the viewpoint of conductivity imparting effect.
[0111]
In the resin composition of the present invention, the conductivity imparting material is preferably blended within a range of 0.01 to 15% by weight with respect to 100% by weight of the resin composition. When the conductivity-imparting material is less than 0.01% by weight, it is difficult to obtain a desired conductivity-imparting effect, and when it exceeds 15% by weight, not only the fluidity at the time of molding is lowered and the thin-wall moldability is inferior, High cost and high specific gravity may be undesirable. The composition is more preferably in the range of 0.05 to 10% by weight, and still more preferably in the range of 0.1 to 8% by weight.
[0112]
Further, such filler and conductivity imparting material may be swollen with a swelling agent, or may be organicized with an organic agent. The swelling agent or organic agent is not particularly limited as long as it can swell or organicize the filler by ion exchange or the like. Specifically, ε-caprolactam, 12-aminododecanoic acid, 12-aminolauric acid And alkylammonium salts (such as dimethyldialkylammonium). Especially when a swollen or organic filler (preferably montmorillonite, mica, saponite, hectorite, sepiolite) is blended in polyamide resin, polypropylene resin, polyacetal resin, styrene resin, acrylic resin, etc. It is preferable because the material can be dispersed in the nano order and desired characteristics can be obtained with a smaller amount.
[0113]
When the filler, conductivity imparting agent, flame retardant and the like are blended with the resin composition of the present invention, the resin may be kneaded in advance with an extruder or the like, or may be dried separately from the resin composition. You may mix | blend by blend, application | coating, etc. Moreover, you may mix beforehand at the time of superposition | polymerization of resin.
[0114]
The flame-retardant polyamide molded product of the present invention includes, for example, injection molding (injection compression molding, gas assist injection molding, insert molding, etc.), blow molding, rotational molding, extrusion molding, press molding, transfer molding (RIM molding, etc.), filament Although it is molded by a known molding method such as winding molding, the most desirable molding method is preferably molded by an injection molding method with high productivity.
[0115]
As the form of the molding material used for such molding, pellets, BMC, SMC, stampable sheets, prepregs (sheets, yarns, etc.) can be used, but the most desirable molding material is pellets used for injection molding. Yes, the most desirable form is long fiber pellets.
[0116]
In the present invention, the pellets are required to contain components (A) to (F) and, if necessary, (G) to (J) and other components in a desired amount, respectively, or some of them. This refers to a product obtained by kneading with an extruder or the like a number of times and cutting the extruded product into a desired length (hereinafter, this series of steps is referred to as a compound). Moreover, what was obtained by dry-blending the said pellet and the pellet which does not contain a component (F) at least is also called a pellet. The component (F) used in the compound may be a discontinuous yarn such as a chopped yarn or a milled yarn or a continuous yarn.
[0117]
In order for the flame-retardant polyamide molded article comprising the flame-retardant polyamide resin composition of the present invention to have high flame retardancy, electrical conductivity and mechanical properties (strength, rigidity, impact strength, etc.), Although it is effective to increase the length of the component (F), it is desirable to take the form of long fiber pellets among the above-mentioned pellets.
[0118]
In the case of molding using long fiber pellets, the length of the component (F) in the molded product can be maintained long, so in addition to mechanical properties, especially flame retardancy and conductivity are dramatically improved. Can be improved. That is, even when high flame retardancy and electrical conductivity cannot be achieved with normal pellets, when long fiber pellets are used, flame retardancy at 1.2 mm thickness in the UL-94 standard is V-0 class. In addition, it is possible to achieve high flame retardance (particularly a drip prevention effect) such as a volume resistivity of 100 Ω · cm or less, and electrical conductivity. In particular, when the compounding amount of the component (F) is as low as 20% by weight or less, the flame retardancy (particularly the drip prevention effect) and the electrical conductivity development effect are significant compared to ordinary pellets. The use of the long fiber pellets with the blending ratio of the component (F) in such a range is very effective for achieving high flame retardancy and electrical conductivity. Of course, the effect of improving the mechanical properties (especially impact strength) is also enormous.
[0119]
On the other hand, when the blending ratio of the component (F) exceeds 20% by weight, flame retardance and electrical conductivity can be achieved to some extent even with normal pellets. However, with respect to flame retardancy, electrical conductivity, and mechanical properties (particularly impact strength), the improvement effect is small and does not reach the improvement effect of long fiber pellets.
[0120]
The pellet length of the long fiber pellet of the present invention is preferably in the range of 2 to 26 mm. More preferably, it exists in the range of 4-15 mm, More preferably, it exists in the range of 5-10 mm.
[0121]
The long fiber pellet in the present invention is, for example, as shown in JP-B-63-37694, in which fibers are arranged substantially parallel to the longitudinal direction of the pellet, and the length of the fiber in the pellet is substantially the same as the pellet length. Or the thing containing the pellet which is more than it is pointed out. In this case, each component in the present invention including at least the component (A) and / or the component (B) may be impregnated in the component (F) bundle or coated with the component (F) bundle. .
[0122]
In the case of impregnated long fiber pellets, for example,
(1) A method of impregnating each component of the present invention, such as a resin, using an impregnation tank containing a resin emulsion, suspension, solution or melt.
(2) A method of impregnating each component of the present invention such as a resin by heating after dispersing the resin powder in the component (F),
(3) A method of impregnating each component of the present invention such as a resin while pulling out the component (F) using a crosshead die extruded from a molten resin,
Although known impregnation methods such as the above can be used, in order to blend the components of the present invention uniformly and in desired amounts, it is preferable to use the impregnation method described in (3) above.
[0123]
In the case of a coated long fiber pellet, it is a core-sheath type long fiber pellet composed of at least a core part composed of the component (F) bundle and a sheath part composed of at least the component (A) and / or the component (B). Is preferred. In the case of the core-sheath type long fiber pellet, the component (F) bundle is a resin (hereinafter referred to as a low-viscosity resin) which is not higher than the melt viscosity of the resin having the largest blending amount among the components (A) and (B). It is desirable to coat with each component in the present invention including at least the component (A) and / or the component (B) after being pre-impregnated with and forming a composite of the component (F) and the low-viscosity resin. . Examples of the low-viscosity resin include an epoxy resin, an alcohol (or water) soluble polyamide resin, a polyamide resin having a molecular weight equal to or less than the component (A) and / or the component (B), or the component (G) and the component (H). And so on. In addition, about a component (B), you may knead | mix beforehand with a component (A) etc. and may arrange | position in the sheath part of a long fiber pellet, and you may mix | blend by dry blend separately from a long fiber pellet. Regarding the component (E), it may be pre-mixed in the component (F) bundle, pre-mixed in the sizing agent of the component (F), or kneaded in the low-viscosity resin. Good.
[0124]
The blending form of the pellets of the present invention is not particularly limited. Desirably, the pellets contain at least the component (A) and / or the component (B) and do not contain the component (F), and the component (F) bundle of low viscosity resin. After forming a composite of a low-viscosity resin and component (F) in advance, dry blending with at least component (A) and / or long fiber pellets coated with the composite with component (B) What you did is good. Particularly preferably, a pellet containing no component (F) obtained by compounding component (A), component (C), component (E) (component (J) if necessary), component (A), component (B) , Component (D), component (E) (component (H), component (I), component (J) as necessary) in the present invention, each component in the present invention, component (F) by component (G) in advance A dry blend of long fiber pellets coated with a composite impregnated with a bundle is preferable.
[0125]
In order to simultaneously achieve high flame retardancy, electrical conductivity, and mechanical properties (particularly strength and impact strength) in a flame-retardant polyamide molded product by injection molding using the pellets, the component (F) in the molded product is used. As described above, it is effective to increase the length of the mold. In this case, however, the influence of the molding conditions, the injection molding machine, and the mold must be taken into consideration. Regarding the molding conditions, the lower the back pressure, the slower the injection speed, and the slower the screw rotation speed, the longer the length of the component (F) in the molded product. It is desirable to set it as low as possible so that does not become unstable. Desirable back pressure is 0.1-1 MPa It is. Regarding the injection molding machine, the longer the nozzle diameter, the smaller the taper angle of the nozzle, the deeper the screw groove depth, and the lower the compression ratio, the longer the length of the component (F) in the molded product tends to be. is there. About a metal mold | die, there exists a tendency for the length of the component (F) in a molded article to become long, so that a sprue diameter, a runner diameter, and a gate diameter are enlarged.
[0126]
As described above, in order for the flame-retardant polyamide molded product of the present invention to have high flame retardancy, electrical conductivity, and mechanical properties, at least 3% by weight of the total amount of carbon fibers contained in the molded product is 1%. It is preferable to be within a range of ˜15 mm. More preferably, at least 5% by weight of the total amount of carbon fibers is in the range of 1-10 mm, and more preferably at least 5% by weight of the total amount of carbon fibers is in the range of 1-7 mm. Particularly preferably, at least 8% by weight of the total carbon fiber is in the range of 1 to 7 mm.
[0127]
The flame-retardant polyamide resin composition and molded product thereof according to the present invention are not only due to high conductivity and high thin-wall moldability, but also due to the blending of the components (B), (C), (D), and (E). As a molded product that has flame retardancy at 1.2 mm thickness or better than the V-0 class in the UL-94 standard because it has high flame retardancy (particularly anti-drip) Used.
[0128]
Here, the flame retardancy of the V-0 class refers to the combustion time and its state, the presence or absence of fire spread, and the presence or absence of dripping (drip) in the UL-94 standard (American Combustion Test Method devised by Underwriters Laboratories Inc.). And flame retardancy that satisfies the conditions of the V-0 class defined by the flammability of the dripping substance and the like. Further, the flame retardancy better than V-0 means that the flame retardancy exhibits a shorter burning time than the specified value in the V-0 class, and the V-0 class in the case where the thickness of the test piece is thinner. Refers to flame retardant that satisfies the specified conditions.
[0129]
In the present invention, when a UL-94 test piece is molded, the test piece is obtained by basically orienting the component (F) in the direction perpendicular to the long side direction of the test piece. In particular, when molding by injection molding, a test piece is obtained by molding using a mold filled with a film gate extending over the entire length in the long side direction of the test piece. In molding, the cylinder temperature of the injection molding machine is in the range of 260 to 280 ° C., and the mold temperature is 80 ° C.
[0130]
Since the flame-retardant polyamide resin composition of the present invention and the molded product thereof can impart higher flame retardancy depending on the blending ratio of the components, it is difficult to achieve a thickness of 0.8 mm (1/32 inch). It is preferably used at a level of flammability of V-0 class or better.
[0131]
Since the flame-retardant polyamide molded article in the present invention has not only high flame retardancy and high thin-wall moldability, but also high conductivity due to components (E) and (F), the volume resistivity value is It is desirable to use it as a flame-retardant polyamide molded product having a resistance of 100Ω · cm or less. When the volume specific resistance value exceeds 100 Ω · cm, it is difficult to adapt to uses such as an electromagnetic shielding material, and the use is limited. A more desirable volume resistivity value is 50 Ω · cm, and a more desirable volume resistivity value is 10 Ω · cm.
[0132]
The volume specific resistance value here refers to the value obtained by subtracting the contact resistance value of the measuring instrument, jig, etc. from the electric resistance value of both ends coated with the conductive paste of the test piece having a rectangular parallelepiped shape, It is calculated by multiplying the end area of the test piece and dividing by the test piece length. In the present invention, the unit is Ω · cm.
[0133]
The flame-retardant polyamide molded product according to the present invention has not only high flame retardancy and high thin-wall moldability, but also high rigidity due to the component (F), so it is ASTM D790 standard (span distance L / plate thickness). D = 16), the bending stiffness at a thickness of 6.4 mm (1/4 inch) is in the range of 8 to 40 GPa, preferably in the range of 10 to 30 GPa, particularly preferably in the range of 12 to 25 GPa. It may be used as a flame retardant polyamide molded product.
[0134]
The flame-retardant polyamide molded product in the present invention has high flame retardance (especially anti-drip property), thin-wall moldability (fluidity during molding), and electrical conductivity. It is possible to make the thickness thinner than the product, and it is optimal to use it as a thin molded product having a thickness of 4 mm or less.
Preferably, the effect of the present invention can be exhibited more by using as a thin molded product having a thickness of 3 mm or less, more preferably 2 mm or less. Particularly preferably, it is used as a thin molded product having a wall thickness of 1.6 mm or less. The thickness of the molded product here refers to the thickness of a flat plate portion excluding protrusions such as a rib portion and a boss portion in the molded product.
[0135]
Applications of the flame-retardant polyamide molded product in the present invention include members for electronic and electrical equipment that require high flame retardancy, moldability, and mechanical properties (particularly rigidity) in thin molded products. Since the flame-retardant polyamide molded product of the present invention can achieve high rigidity, light weight, electromagnetic wave shielding properties, etc., it can be used in portable electronic / electrical equipment, OA equipment, home appliances, automotive housings, casings, and the like. It is effective for applications such as parts. More specifically, a housing, casing, or the like for a large display, a notebook computer, a portable telephone, a PHS, a PDA (a portable information terminal such as an electronic notebook), a video camera, a digital still camera, a portable radio cassette player, or the like It is preferably used for those parts.
[0136]
In addition, since it has high conductivity, it is possible to impart charge / discharge prevention properties by adding a small amount of carbon fiber, and members that require these characteristics, such as IC trays, baskets for carrying silicon wafers, etc. It is also useful for adaptation.
[0137]
【Example】
Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are not intended to limit the present invention, and all modifications can be made without departing from the gist of the preceding and following descriptions. Is included.
[0138]
  Evaluation items and methods of the obtained flame-retardant polyamide molded product are as follows.
(A) Flame retardancy
  Evaluation was made by a flame retardancy test based on the UL-94 standard. The thicknesses of the test pieces used were 1.2 mm and 0.8 mm (1/32 inch). The injection molding is performed using a mold filled with a film gate extending over the entire length in the long side direction of the test piece, using an injection molding machine IS100 (manufactured by Toshiba Machine, mold clamping force 100 t), a cylinder temperature of 280 ° C., The mold temperature was 80 ° C.
(B) Volume resistivity
  A test piece having a width of 12.7 mm, a length of 65 mm, and a thickness of 2 mm, which was injection-molded with a fan gate, was subjected to measurement in an absolutely dry state (water content of 0.1% or less). First, apply the conductive paste (Dotite manufactured by Fujikura Kasei Co., Ltd.) to the width x thickness surface, dry the conductive paste sufficiently, and then press the surface to the electrodes to determine the electrical resistance value between the electrodes. Measure with a digital multimeter (FLUKE). The value obtained by subtracting the contact resistance of the measuring instrument, jig, etc. from the electrical resistance value is multiplied by the area of the conductive paste application surface, and then the value is divided by the length of the test piece as the volume specific resistance value ( Unit is Ω · cm). The injection molding was performed at a cylinder temperature of 280 ° C. and a mold temperature of 70 ° C.
(C) Bending rigidity
  The bending rigidity was evaluated based on the ASTM D 790 standard (span distance L / plate thickness D = 16) (unit: GPa). The thickness of the test piece used was 6.4 mm (1/4 inch), and the test piece was used at a moisture content of 0.1% or less. The injection molding was performed at a cylinder temperature of 280 ° C. and a mold temperature of 70 ° C.
(D) Impact strength
  Evaluation was made by IZOD impact strength with a mold notch conforming to ASTM D256 standard (unit: J / m). The thickness of the test piece used was 3.2 mm (1/8 inch), and the test piece was used at a moisture content of 0.1% or less. The injection molding was performed at a cylinder temperature of 280 ° C. and a mold temperature of 70 ° C.
(E) Appearance quality
  For a box-shaped test piece having a projected area of 155 mm in width, 190 mm in length, 1 mm in thickness and 12 mm in height, which is injection-molded with an 8-point pin gate, the presence or absence of surface gloss, sink, weld, and carbon fiber float・ About defects such as dispersion, ◎ (without the aforementioned defects), ○ (having any one of the aforementioned defects), △ (having any two of the aforementioned defects), × (having all the aforementioned defects), relative Was visually evaluated. The injection molding was performed at a cylinder temperature of 280 ° C. and a mold temperature of 60 ° C.
(F) Thin wall formability
  The thin formability was evaluated by the injection pressure when injection molding a thin flat plate having a width of 150 mm, a length of 150 mm, and a thickness of 1 mm using a fan gate (unit: MPa). It can be said that the lower the injection pressure, the better the thin moldability (fluidity during injection molding). Injection molding was performed using an injection molding machine J150EII-P (manufactured by Nippon Steel Works, mold clamping force 150 t) at a cylinder temperature of 280 ° C. and a mold temperature of 70 ° C.
(G) Paintability
  Regarding the state of bleeding out when the thin flat plate molded in the item (f) is left at a temperature of 66 ° C. and a humidity of 85% for 50 days, ○ (no bleeding out), Δ (slightly bleeding out), × ( With bleed-out), it was evaluated visually.
(referenceExample 1 and Comparative Example 1)
  Component (A), Component (B), Component (D), Component (E) and Component (F) made into chopped yarn are melted in a twin screw extruder (A), Component (B) , And other components are extruded while impregnating into the component (F) bundle. The resin gut obtained as described above containing only discontinuous component (F) is cut into a length of 5 mm with a cutter to obtain pellets.
[0139]
Further, desired amounts of component (A), component (C), and component (E) are compounded with a single screw extruder to obtain flame retardant master pellets 1. The obtained flame retardant master pellets 1 and the pellets were dry blended at a desired ratio and dried in a vacuum at 80 ° C. for 5 hours or more, and then each test described in the items (a) to (f). It used for injection molding.
[0140]
Table 1 shows the blending ratio of each component and the evaluation results.
[0141]
  referenceIn Example 1, the flame retardance of 1.2 mm thickness and 0.8 mm (1/32 inch) thickness was V-0 class judgment, and was excellent in flame retardancy and excellent in thin-wall moldability. However, in Comparative Example 1, the flame retardancy was V-2 determination, and the flame retardancy was inferior.
(Example1-5Comparative Examples 2 to 4)
  First, a desired amount of component (A), component (B), component (D), component (E), and if necessary, component (G) and component (H) are compounded with a twin-screw extruder, and flame retardant Master pellet 2 is obtained. The obtained flame retardant master pellet 2 is extruded in a single screw extruder in a sufficiently kneaded state in a crosshead die attached to the tip thereof, and at the same time, the continuous yarn of component (F) is also put into the crosshead die. By continuously supplying, the component (A), the component (B), and other components are sufficiently impregnated in the component (F) bundle. Here, the crosshead die impregnates the component (F) bundle with the melted component (A), component (B), and other components while opening the component (F) bundle in the die. Refers to the device. As the component (F), the resin strand obtained as described above containing most of which is a continuous yarn is cut into a length of 7 mm with a cutter to obtain a long fiber pellet.
[0142]
The obtained long fiber pellets and the flame retardant master pellets 1 are dry blended at a desired ratio, dried in a vacuum at 80 ° C. for 5 hours or more, and then each test described in the items (a) to (f). Used for injection molding.
[0143]
Table 1 shows the blending ratio of each component and the evaluation results.
[0144]
  Example1-5Any flame retardant polyamide molded product of 1.2mm thickness and 0.8mm (1/32 inch) thickness has excellent flame retardancy according to V-0 class judgment, and thin moldability Also excellent. Example with component (H) added3,4Was particularly excellent in thin-wall formability. On the other hand, the flame-retardant polyamide molded products of Comparative Examples 1 and 2 were inferior in flame retardancy because the flame retardancy was V-2 determination for both 1.2 mm thickness and 0.8 mm thickness. In addition, the flame-retardant polyamide molded products of Comparative Examples 3 and 4 were not only V-2 class judged at 1.2 mm thickness but V-2 judgment at 0.8 mm thickness. Poor formability, especially paintability.
[0145]
[Table 1]

[0146]
  In addition, the description of each component in Table 1 is based on the following.
Ingredient (A)
  Ny6: Nylon 6 resin [ηr = 2.4]
  m-Ny6: Modified nylon 6 resin [Nylon 6 resin obtained by modifying the amino terminal group of Ny6 with an acid anhydride]
Ingredient (B)
  Ny6TI: Nylon 6T / 6I copolymer resin [ηr = 2.1]
  MXD6: polymetaxylylene adipamide [ηr = 2.2]
  Ny66I: nylon 66/6 / 6I copolymer resin [ηr = 2.0]
Ingredient (C)
  RP: Red phosphorus [Nova Excel 140 manufactured by Rin Chemical Industry Co., Ltd .: Average particle size = about 30 μm, phenolic thermosetting resin coating, conductivity = about 180-200 μS / cm]
Ingredient (D)
  Mg: Magnesium hydroxide [Kisuma 5E-U, manufactured by Kyowa Chemical Industry Co., Ltd .: Synthetic type, average crystal grain size = about 1.0 μm, amide-based highly polar resin coating, granular product]
Ingredient (E)
  CB1: Carbon black [I₂/ I₁= 0.68, I₂/ I_Three= 0.60]
  CB2: Carbon black [I₂/ I₁= 0.35, I₂/ I_Three= 0.39]
Ingredient (F)
  CF1: Carbon fiber [Toray Industries, Inc. trading card T700SC-12K-50C: average fiber diameter = about 7 μm]
  CF2: Carbon fiber [Toray Industries, Inc. Torayca T300B-12K-50B, average fiber diameter = about 7 μm]
Ingredient (G)
  T / P: Terpene / phenol copolymer resin [YP902 manufactured by Yasuhara Chemical Co., Ltd.]
Ingredient (H)
  LCP: Liquid crystalline resin [528 parts by weight of p-hydroxybenzoic acid, 126 parts by weight of 4,4′-dihydroxybiphenyl, 112 parts by weight of terephthalic acid, 864 parts by weight of polyethylene terephthalate having an intrinsic viscosity of about 0.6 dl / g And 586 parts by weight of acetic anhydride in a reaction vessel equipped with a stirring blade and a distillation pipe, and obtained by polymerization, 42.5 mol% of aromatic oxycarbonyl units, 7.5 mol% of aromatic dioxy units, Liquid crystalline resin consisting of 50 mol% ethylenedioxy units and 57.5 mol% aromatic dicarboxylic acid units and having a melting point of 208 ° C. and a melt viscosity of 15 Pa · s.
Other ingredients
  WOL: Wollastonite [FPW # 400S manufactured by Kinsei Matec Co., Ltd.]
  From the results in Table 1, the following is clear.
1. Effect of component (B) (Example)1,2And comparison with Comparative Examples 2 to 4)
  Example in which the aromatic-containing polyamide resin (and carbon black) of the present invention is blended as compared with Comparative Example 2 in which the aromatic-containing polyamide resin is not blended1,2Can obtain a molded product with extremely high flame retardancy (V-0 class), and its superiority is clear.
[0147]
  Further, compared to Comparative Examples 3 and 4 that achieve V-0 class flame retardance at 1.2 mm thickness without blending aromatic-containing polyamide resin, aromatic-containing polyamide resin (and metal water) Example of blending oxide)1-2Can reduce the amount of component (C) that can cause problems such as paintability (bleed out) and generation of toxic gas during combustion, and has the advantage that the problem can be improved. .
[0148]
  Examples1, 2Since the sink and weld can be minimized by blending the aromatic-containing polyamide resin, the appearance quality is superior to those of Comparative Examples 1 and 2.
2. Effect of blending component (E) (Examples)1, 2Comparison with Comparative Examples 1 and 2)
  Example in which the carbon black of the present invention is blended as compared with Comparative Examples 1 and 2 in which no carbon black is blended1, 2Is excellent in flame retardancy (V-0 class) and can lower the volume resistivity, and its superiority is clear.
3. Effect of component (E) type (Reference Example 1,Example 15Comparison between Comparative Example 3 and Comparative Example 4)
  In Comparative Example 4 in which carbon black that is outside the scope of the present invention was blended, the injection pressure was significantly high, and the thin-wall moldability was remarkably inferior. Carbon black included in the scope of the present invention is blendedReference Example 1,Example 15Or the comparative example 3 can make an injection pressure low, and is excellent about thin moldability. In addition, as for appearance defects, compared with Comparative Example 4,Reference Example 1,Example 15Has few defects and excellent appearance quality.
4). Effect of long fiber pellets (referenceExample 1 and Examples1Comparison with
  Using normal pelletsreferenceExample using long fiber pellets compared to Example 11Although the blending ratio of the component (F) is low, the flame retardancy is equivalent, the volume specific resistance can be lowered, and a molded product having flame retardance and conductivity at a higher level is obtained. be able to.
[0149]
  this is,referenceExample over Example 11This is because the length of the component (F) in the molded product can be increased. That is, the example1In contrast, the weight average fiber length lw = 0.493 mm (the component (F) in the range of 1 mm to 7 mm is 8% by weight or more) in the molded article ofreferenceIn the case of Example 1, lw = 0.216 mm (the component (F) of 1 mm or more is less than 1% by weight). In addition, lw is calculated by arbitrarily extracting at least 400 filaments of the component (F) from the molded product, measuring the length to the 1 μm unit with an optical microscope or a scanning electron microscope, and It calculated using Formula 1) or (Formula 2). However, Wi is the weight of the component (F) of length li, and Ni is the number of the component (F) of length li.
[0150]
(Formula 1) lw = Σ (Wi × li) / ΣWi
(Equation 1) can be expressed as (Equation 2) for the component (F) having a constant diameter.
[0151]
(Formula 2) lw = Σ (Ni × li²) / Σ (Ni × li)
In the present invention, as a method for removing components (A) and (B) when measuring lw, a solvent or the like that dissolves only components (A) and (B) and does not dissolve component (F) contained therein is used. A method was adopted in which the molded article was immersed for a certain period of time to sufficiently dissolve the components (A) and (B), and then separated from the component (F) by filtration or the like.
[0152]
  From these comparisons, the importance of the length of the component (F) in the resin molded product on the flame retardancy and conductivity is clear, and as the flame retardant polyamide resin composition used in the present invention, a long It is more desirable to take the form of fiber pellets.
5. Effect of component (H) (Example)1, 2And examples3, 4Comparison with
  Normal pelletreferenceExample which is long fiber pellets compared to Example 11, 2Is high in injection pressure and inferior in fluidity despite the low compounding ratio of component (F). However, according to the combination of component (H), the example3, 4Although it is a long fiber pellet, the fluidity is greatly improved, and it is clear that the component (H) can greatly improve the fluidity.
[0153]
【The invention's effect】
According to the present invention, a flame retardant polyamide resin composition having high flame retardancy (particularly drip prevention), thin moldability (flowability during molding, etc.), appearance quality, and high electrical conductivity, and a molded product thereof Can be provided. Such a flame-retardant polyamide resin composition and a molded product thereof are particularly suitable for a wide range of industrial fields that require the above-described properties, such as housings and casings for electronic devices, and have a great industrial effect.
[Brief description of the drawings]
FIG. 1 is a Raman spectrum diagram of an example of carbon black constituting the flame-retardant polyamide resin composition of the present invention.
[Explanation of symbols]
I₁: Raman shift 1360cm^-1Maximum value of Raman scattering intensity appearing in the vicinity
I₂: Raman shift 1480cm^-1Minimal value of Raman scattering intensity appearing in the vicinity
I_Three: Raman shift 1580cm^-1Maximum value of Raman scattering intensity appearing in the vicinity

Claims (20)

at least,
(A) an aliphatic polyamide resin having a sulfuric acid relative viscosity ηr in the range of 1.5 to 2.7,
(B) an aromatic-containing polyamide resin,
(C) Red phosphorus flame retardant,
(D) metal hydroxide flame retardant,
(E) Carbon black,
(F) carbon fiber,
(G) It consists of phenol or a phenolic resin obtained by condensation reaction of a phenol substituent and a terpene , and contains component (G) within a range of 0.01 to 30% by weight. A flame-retardant polyamide resin composition capable of obtaining a molded article having a flame retardancy at a thickness of 1.2 mm of V-0 class or better. When the total composition is 100% by weight,
5 to 65% by weight of component (B),
2 to 15% by weight of component (C),
1 to 20% by weight of component (D),
Component (E) is 0.5 to 10% by weight,
5 to 35% by weight of component (F),
The flame-retardant polyamide resin composition according to claim 1, which is comprised of each of the following ranges.   The sum total of the weight of each component of a component (C), a component (D), a component (E), and a component (F) occupies within the range of 10 to 60 weight% in the weight of the whole composition. The flame-retardant polyamide resin composition described in 1.   The flame retardant polyamide resin composition according to any one of claims 1 to 3, wherein the aliphatic polyamide resin is at least one selected from nylon 6, water-soluble polyamide resin, and alcohol-soluble polyamide resin.   The flame-retardant polyamide resin composition according to claim 1, wherein the aromatic-containing polyamide resin has a sulfuric acid relative viscosity ηr within a range of 1.5 to 2.7.   The aromatic compound-containing polyamide resin is at least one selected from at least polymetaxylylene adipamide, nylon 6T / 6I, nylon 66 / 6I, and nylon 66/6 / 6I. The flame-retardant polyamide resin composition described in 1.   The flame retardant polyamide resin composition according to claim 1, wherein the red phosphorus flame retardant is red phosphorus coated with a phenol thermosetting resin.   The flame retardant polyamide resin composition according to claim 1, wherein the metal hydroxide flame retardant is magnesium hydroxide.   A flame-retardant polyamide resin composition comprising the flame-retardant polyamide resin composition according to any one of claims 1 to 8 containing a liquid crystalline resin as a component (H) in a range of 0.1 to 15% by weight. .   A flame-retardant polyamide resin composition comprising a fluorine-based resin as component (I) in a range of 0.05 to 10% by weight in the flame-retardant polyamide resin composition according to any one of claims 1 to 9. .   The flame-retardant polyamide resin composition which contains a metal oxide within the range of 0.01 to 10 weight% as a component (J) in the flame-retardant polyamide resin composition in any one of Claims 1-10. .   The flame-retardant polyamide resin composition in which the flame-retardant polyamide resin composition according to claim 1 takes the form of long fiber pellets.   The said long fiber pellet takes the form of the core-sheath-type long fiber pellet which consists of a core part which consists of a component (F) at least and a sheath part which consists of a component (A) or / and a component (B) at least. The flame-retardant polyamide resin composition described in 1.   A flame-retardant polyamide molded article obtained by molding the flame-retardant polyamide resin composition according to claim 1 by injection molding.   The flame-retardant polyamide molded article according to claim 14, wherein at least 3% by weight of the total amount of carbon fibers contained therein has a fiber length in the range of 1 to 15 mm.   The flame-retardant polyamide molded product according to claim 14 or 15, wherein the flame-retardant property in UL-94 standard is 0.8 mm (1/32 inch) thickness and V-0 class or better.   The flame-retardant polyamide molded article according to any one of claims 14 to 16, having a volume resistivity value of 100 Ω · cm or less.   The flame-retardant polyamide molded article according to any one of claims 14 to 17, wherein the flexural modulus according to ASTM D 790 standard is 8 to 40 GPa at a thickness of 6.4 mm (1/4 inch).   The flame-retardant polyamide molded article according to any one of claims 14 to 18, wherein the thickness is within a range of 4 mm or less.   The flame-retardant polyamide molded article according to any one of claims 14 to 19, which is used in any of an electric / electronic device, an OA device, a household electrical appliance, or a housing, casing, or part thereof in an automobile.

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