JP2004143236A - Conductive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition which has excellent high temperature rigidity, excellent heat resistance, excellent flowability, and an excellent balance between conductivity and high speed surface impact strength at low temperature. <P>SOLUTION: This conductive resin composition comprising (A) a polyamide, (B) polyphenylene ether, (C) an impact-improving material, and (D) a conductive filler is characterized by being obtained through a process for melting and kneading the component (B), the component (C) and the component (D) and a process for melting and kneading all or a part of the component (A) and the component (D), wherein the amount of the component (D) in the process is <50wt.%, when the total amount of the component (D) is 100wt.%. <P>COPYRIGHT: (C)2004,JPO

Description

【００２１】
〔式中、Ｏは酸素原子、Ｒはそれぞれ独立して、水素、ハロゲン、第一級もしくは第二級の低級アルキル、フェニル、ハロアルキル、アミノアルキル、炭化水素オキシ、又はハロ炭化水素オキシ（但し、少なくとも２個の炭素原子がハロゲン原子と酸素原子を隔てている）を表わす。〕
【００２２】
本発明のポリフェニレンエーテルの具体的な例としては、例えば、ポリ（２，６−ジメチル−１，４−フェニレンエーテル）、ポリ（２−メチル−６−エチル−１，４−フェニレンエーテル）、ポリ（２−メチル−６−フェニル−１，４−フェニレンエーテル）、ポリ（２，６−ジクロロ−１，４−フェニレンエーテル）等が挙げられ、さらに２，６−ジメチルフェノールと他のフェノール類との共重合体（例えば、特公昭５２−１７８８０号公報に記載されてあるような２，３，６−トリメチルフェノールとの共重合体や２−メチル−６−ブチルフェノールとの共重合体）のごときポリフェニレンエーテル共重合体も挙げられる。
【００２３】
これらの中でも特に好ましいポリフェニレンエーテルとしては、ポリ（２，６−ジメチル−１，４−フェニレンエーテル）、２，６−ジメチルフェノールと２，３，６−トリメチルフェノールとの共重合体、またはこれらの混合物である。
本発明で用いるポリフェニレンエーテルの製造方法は公知の方法で得られるものであれば特に限定されるものではなく、例えば、米国特許第３３０６８７４号公報明細書、同第３３０６８７５号公報明細書、同第３２５７３５７号公報明細書及び同第３２５７３５８号公報明細書、特開昭５０−５１１９７号公報及び同６３−１５２６２８号公報等に記載された製造方法等が挙げられる。
【００２４】
本発明で使用することのできるポリフェニレンエーテルの還元粘度（η_ｓｐ／ｃ：０．５ｇ／ｄｌ、クロロホルム溶液、３０℃測定）は、０．１５〜０．７０ｄｌ／ｇの範囲であることが好ましく、さらに好ましくは０．２０〜０．６０ｄｌ／ｇの範囲、より好ましくは０．４０〜０．５５ｄｌ／ｇの範囲である。
本発明においては、２種以上の還元粘度の異なるポリフェニレンエーテルをブレンドしたものであっても、何ら問題なく使用することができる。例えば、還元粘度０．４５ｄｌ／ｇ以下のポリフェニレンエーテルと還元粘度０．５０ｄｌ／ｇ以上のポリフェニレンエーテルの混合物、還元粘度０．４０ｄｌ／ｇ以下の低分子量ポリフェニレンエーテルと還元粘度０．５０ｄｌ／ｇ以上のポリフェニレンエーテルの混合物等が挙げられるが、もちろん、これらに限定されることはない。
【００２５】
また、本発明に使用できるポリフェニレンエーテルは、重合溶媒に起因する有機溶剤が、ポリフェニレンエーテル１００重量部に対して５重量％未満の量で残存していても構わない。これら重合溶媒に起因する有機溶剤は、重合後の乾燥工程で完全に除去するのは困難であり、通常数百ｐｐｍから数％の範囲で残存しているものである。ここでいう重合溶媒に起因する有機溶媒としては、トルエン、キシレンの各異性体、エチルベンゼン、炭素数１〜５アルコール類、クロロホルム、ジクロルメタン、クロルベンゼン、ジクロルベンゼン等の１種以上が挙げられる。
【００２６】
また、本発明で使用できるポリフェニレンエーテルは、全部又は一部が変性されたポリフェニレンエーテルであっても構わない。
ここでいう変性されたポリフェニレンエーテルとは、分子構造内に少なくとも１個の炭素−炭素二重結合または、三重結合及び少なくとも１個のカルボン酸基、酸無水物基、アミノ基、水酸基、又はグリシジル基を有する、少なくとも１種の変性化合物で変性されたポリフェニレンエーテルを指す。
【００２７】
該変性されたポリフェニレンエーテルの製法としては、（１）ラジカル開始剤の存在下、非存在下で１００℃以上、ポリフェニレンエーテルのガラス転移温度未満の範囲の温度でポリフェニレンエーテルを溶融させることなく変性化合物と反応させる方法、（２）ラジカル開始剤の存在下、非存在下でポリフェニレンエーテルのガラス転移温度以上３６０℃以下の範囲の温度で変性化合物と溶融混練し反応させる方法、（３）ラジカル開始剤の存在下、非存在下でポリフェニレンエーテルのガラス転移温度未満の温度で、ポリフェニレンエーテルと変性化合物を溶液中で反応させる方法等が挙げられ、これらいずれの方法でも構わないが、（１）及び、（２）の方法が好ましい。
【００２８】
次に分子構造内に少なくとも１個の炭素−炭素二重結合または、三重結合及び少なくとも１個のカルボン酸基、酸無水物基、アミノ基、水酸基、又はグリシジル基を有する少なくとも１種の変性化合物について具体的に説明する。
分子内に炭素−炭素二重結合とカルボン酸基、酸無水物基を同時に有する変性化合物としては、マレイン酸、フマル酸、クロロマレイン酸、シス−４−シクロヘキセン−１，２−ジカルボン酸及びこれらの酸無水物などが挙げられる。特にフマル酸、マレイン酸、無水マレイン酸が良好で、フマル酸、無水マレイン酸が特に好ましい。
【００２９】
また、これら不飽和ジカルボン酸のカルボキシル基の、１個または２個のカルボキシル基がエステルになっているものも使用可能である。
分子内に炭素−炭素二重結合とグリシジル基を同時に有する変性化合物としては、アリルグリシジルエーテル、グリシジルアクリレート、グリシジルメタアクリレート、エポキシ化天然油脂等が挙げられる。
これらの中でグリシジルアクリレート、グリシジルメタアクリレートが特に好ましい。
【００３０】
分子内に炭素−炭素二重結合と水酸基を同時に有する変性化合物としては、アリルアルコール、４−ペンテン−１−オール、１，４−ペンタジエン−３−オールなどの一般式Ｃ_ｎＨ_２ｎ−３ＯＨ（ｎは正の整数）の不飽和アルコール、一般式Ｃ_ｎＨ_２ｎ−５ＯＨ、Ｃ_ｎＨ_２ｎ−７ＯＨ（ｎは正の整数）等の不飽和アルコール等が挙げられる。
上述した変性化合物は、それぞれ単独で用いても良いし、２種以上を組み合わせて用いても良い。
【００３１】
変性されたポリフェニレンエーテルを製造する際の変性化合物の添加量は、ポリフェニレンエーテル１００重量部に対して０．１〜１０重量部が好ましく、更に好ましくは０．３〜５重量部である。
ラジカル開始剤を用いて変性されたポリフェニレンエーテルを製造する際の好ましいラジカル開始剤の量は、ポリフェニレンエーテル１００重量部に対して０．００１〜１重量部である。
【００３２】
また、変性されたポリフェニレンエーテル中の変性化合物の付加率は、０．０１〜５重量％が好ましい。より好ましくは０．１〜３重量％である。
該変性されたポリフェニレンエーテル中には、未反応の変性化合物及び／または、変性化合物の重合体が残存していても構わない。
また、変性されたポリフェニレンエーテル中に残存する変性化合物及び／または、変性化合物の重合体の量を減少させるために、該変性されたポリフェニレンエーテルを製造する際に、必要に応じてアミド結合及び／またはアミノ基を有する化合物を添加しても構わない。
【００３３】
ここでいうアミド結合を有する化合物とは、分子構造中にアミド結合｛−ＮＨ−Ｃ（＝Ｏ）−｝構造を有する化合物であり、アミノ基を有する化合物とは末端に｛−ＮＨ_２｝構造を有する化合物である。これら化合物の具体例としては、オクチルアミン、ノニルアミン、テトラメチレンジアミン、ヘキサメチレンジアミン等の脂肪族アミン類、アニリン、ｍ−フェニレンジアミン、ｐ−フェニレンジアミン、ｍ−キシリレンジアミン、ｐ−キシリレンジアミン等の芳香族アミン類、上記アミン類とカルボン酸、ジカルボン酸等との反応物、ε−カプロラクタム等のラクタム類及び、ポリアミド樹脂等が挙げられるが、これらに限定されるものではない。
【００３４】
これらアミド結合またはアミノ基を有する化合物を添加する際の好ましい添加量は、ポリフェニレンエーテル１００重量部に対し０．００１重量部以上、５重量部未満である。好ましくは０．０１重量部以上、１重量部未満、より好ましくは０．０１重量部以上〜０．１重量部未満である。
また、本発明では、スチレン系熱可塑性樹脂をポリアミドとポリフェニレンエーテルの合計１００重量部に対し、５０重量部未満の量であれば配合しても構わない。
【００３５】
本発明でいうスチレン系熱可塑性樹脂としては、ホモポリスチレン、ゴム変性ポリスチレン（ＨＩＰＳ）、スチレン−アクリロニトリル共重合体（ＡＳ樹脂）、スチレン−ゴム質重合体−アクリロニトリル共重合体（ＡＢＳ樹脂）等が挙げられる。
更に、ポリフェニレンエーテルに添加することが可能な公知の添加剤等もポリフェニレンエーテル１００重量部に対して１０重量部未満の量で添加しても構わない。
【００３６】
次に、本発明で使用することのできる（Ｃ）成分の衝撃改良材について説明する。
本発明で使用することのできる衝撃改良材は、芳香族ビニル化合物を主体とする重合体ブロックと共役ジエン化合物を主体とする重合体ブロックから構成される芳香族ビニル化合物−共役ジエン化合物ブロック共重合体、その水素添加物及びエチレン−α−オレフィン共重合体からなる群より選ばれる１種以上である。
【００３７】
本発明における芳香族ビニル化合物−共役ジエン化合物ブロック共重合体で使用することのできる芳香族ビニル化合物の具体例としてはスチレン、α−メチルスチレン、ビニルトルエン等が挙げられ、これらから選ばれた１種以上の化合物が用いられるが、中でもスチレンが特に好ましい。
また、共役ジエン化合物の具体例としては、ブタジエン、イソプレン、ピペリレン、１，３−ペンタジエン等が挙げられ、これらから選ばれた１種以上の化合物が用いられるが、中でもブタジエン、イソプレンおよびこれらの組み合わせが好ましい。
【００３８】
該ブロック共重合体の共役ジエン化合物のソフトセグメント部分のミクロ構造は１，２−ビニル含量もしくは１，２−ビニル含量と３，４−ビニル含量の合計量が５〜８０％が好ましく、さらには１０〜５０％が好ましく、１０〜４０％が最も好ましい。
本発明におけるブロック共重合体は、芳香族ビニル化合物を主体とする重合体ブロック［Ａ］と共役ジエン化合物を主体とする重合体ブロック［Ｂ］がＡ−Ｂ型、Ａ−Ｂ−Ａ型、Ａ−Ｂ−Ａ−Ｂ型のから選ばれる結合形式を有するブロック共重合体である事が好ましい。
【００３９】
これらの中でもＡ−Ｂ−Ａ型、Ａ−Ｂ−Ａ−Ｂ型がより好ましい。これらはもちろん混合物であっても構わない。
また、本発明で使用することのできる芳香族ビニル化合物と共役ジエン化合物のブロック共重合体は、水素添加されたブロック共重合体であることがより好ましい。水素添加されたブロック共重合体とは、上述の芳香族ビニル化合物と共役ジエン化合物のブロック共重合体を水素添加処理することにより、共役ジエン化合物を主体とする重合体ブロックの脂肪族二重結合を０を越えて１００％の範囲で制御したものをいう。該水素添加されたブロック共重合体の好ましい水素添加率は５０％以上であり、より好ましくは８０％以上、最も好ましくは９８％以上である。
【００４０】
これらブロック共重合体は水素添加されていないブロック共重合体と水素添加されたブロック共重合体の混合物としても問題なく使用可能である。
本発明において、使用する衝撃改良材として、低分子量衝撃改良材と高分子量衝撃改良材の混合物を使用することで低温時の高速面衝撃強度を更に向上させることが可能である。
具体的には、数平均分子量１２０，０００未満の低分子量衝撃改良材と、数平均分子量１２０，０００以上の高分子量衝撃改良材の混合物であることが望ましい。
【００４１】
本発明でいう数平均分子量とは、ゲルパーミエーションクロマトグラフィー測定装置［ＧＰＣ　ＳＹＳＴＥＭ２１：昭和電工（株）製］を用いて、紫外分光検出器［ＵＶ−４１：昭和電工（株）製］で測定し、標準ポリスチレンで換算した数平均分子量の事を指す。［溶媒：クロロホルム、温度：４０℃、カラム：サンプル側（Ｋ−Ｇ，Ｋ−８００ＲＬ，Ｋ−８００Ｒ）、リファレンス側（Ｋ−８０５Ｌ×２本）、流量１０ｍｌ／分、測定波長：２５４ｎｍ，圧力１５〜１７ｋｇ／ｃｍ^２）。この時、重合時の触媒失活による低分子量成分が検出されることがあるが、その場合は分子量計算に低分子量成分は含めない。通常、計算された正しい分子量分布（重量平均分子量／数平均分子量）は１．０〜１．１の範囲内である。
【００４２】
これら低分子量ブロック共重合体と高分子量ブロック共重合体の重量比は、低分子量ブロック共重合体／高分子量ブロック共重合体＝９５／５〜５／９５である。好ましくは９０／１０〜１０／９０である。
また、本発明においては、低分子量ブロック共重合体として、芳香族ビニル化合物を主体とする一つの重合体ブロックの数平均分子量が２０，０００以上であるブロック共重合体を使用することで、さらに高温時の剛性を向上させるという付加的な効果を得ることができる。
【００４３】
芳香族ビニル化合物を主体とする一つの重合体ブロックの数平均分子量は、上述したブロック共重合体の数平均分子量を用いて、下式により求めることができる。
Ｍｎ_（ａ）＝｛Ｍｎ×ａ／（ａ＋ｂ）｝／Ｎ
［上式中において、Ｍｎ_（ａ）は芳香族ビニル化合物を主体とする一つの重合体ブロックの数平均分子量、Ｍｎはブロック共重合体の数平均分子量、ａはブロック共重合体中のすべての芳香族ビニル化合物を主体とする重合体ブロックの重量％、ｂはブロック共重合体中のすべての共役ジエン化合物を主体とする重合体ブロックの重量％、そしてＮはブロック共重合体中の芳香族ビニル化合物を主体とする重合体ブロックの数を表す。］
【００４４】
また、本発明において、低分子量ブロック共重合体の芳香族ビニル化合物を主体とする重合体ブロックの含有量の好ましい範囲は、５５重量％以上９０重量％未満である。低分子量ブロック共重合体に、この範囲内の芳香族ビニル重合体ブロックを持つブロック共重合体を用いることにより、耐熱性を向上させることができるため、より好適に使用することができる。
更に、本発明において、低分子量ブロック共重合体を、芳香族ビニル化合物を主体とする重合体ブロックを５５重量％以上９０重量％未満の量で含有するブロック共重合体と、芳香族ビニル化合物を主体とする重合体ブロックを２０重量％以上５５重量％未満の量で含有するブロック共重合体との混合物にする事により、流動性を向上させることが可能となる。
また、本発明のブロック共重合体中には、パラフィンを主成分とするオイルをあらかじめ混合したものを用いても構わない。パラフィンを主成分とするオイルをあらかじめ混合する事により、樹脂組成物の加工性を向上させることができる。
【００４５】
この際の好ましいパラフィンを主成分とするオイルの量はブロック共重合体１００重量部に対して、１〜７０重量部である。７０重量部以上混合すると取り扱い性に劣る。
ここでいうパラフィンを主成分とするオイルとは、芳香環含有化合物、ナフテン環含有化合物及び、パラフィン系化合物の三者が組み合わさった重量平均分子量５００〜１００００の範囲の炭化水素系化合物の混合物であり、パラフィン系化合物の含有量が５０重量％以上のものである。
【００４６】
より好ましくは、パラフィン系化合物が５０〜９０重量％，ナフテン環含有化合物が１０〜４０重量％、芳香環含有化合物が５重量％以下のものである。
これら、パラフィンを主成分とするオイルは市販されており、例えば出光興産（株）製のＰＷ３８０等が挙げられる。
これら芳香族ビニル化合物−共役ジエン化合物のブロック共重合体は、本発明の趣旨に反しない限り、結合形式の異なるもの、芳香族ビニル化合物種の異なるもの、共役ジエン化合物種の異なるもの、１，２−結合ビニル含有量もしくは１，２−結合ビニル含有量と３，４−結合ビニル含有量の異なるもの、芳香族ビニル化合物成分含有量の異なるもの、水素添加率の異なるもの等混合して用いても構わない。
【００４７】
本発明で使用することのできるエチレン−α−オレフィン共重合体としては、特開２００１−３０２９１１号公報に記載されているエチレン−α−オレフィン共重合体が使用可能である。
また、本発明で使用する衝撃改良材は、全部又は一部が変性された衝撃改良材であっても構わない。
ここでいう変性された衝撃改良材とは、分子構造内に少なくとも１個の炭素−炭素二重結合または、三重結合及び少なくとも１個のカルボン酸基、酸無水物基、アミノ基、水酸基、又はグリシジル基を有する、少なくとも１種の変性化合物で変性された衝撃改良材を指す。
【００４８】
該変性された衝撃改良材の製法としては、（１）ラジカル開始剤の存在下、非存在下で衝撃改良材の軟化点温度以上２５０℃以下の範囲の温度で変性化合物と溶融混練し反応させる方法、（２）ラジカル開始剤の存在下、非存在下で衝撃改良材の軟化点以下の温度で、衝撃改良材と変性化合物を溶液中で反応させる方法、（３）ラジカル開始剤の存在下、非存在下で衝撃改良材の軟化点以下の温度で、衝撃改良材と変性化合物を溶融させることなく反応させる方法等が挙げられ、これらいずれの方法でも構わないが、（１）の方法が好ましく、更には（１）の中でもラジカル開始剤存在下で行う方法が最も好ましい。
【００４９】
ここでいう分子構造内に少なくとも１個の炭素−炭素二重結合または、三重結合及び少なくとも１個のカルボン酸基、酸無水物基、アミノ基、水酸基、又はグリシジル基を有する少なくとも１種の変性化合物とは、変性されたポリフェニレンエーテルで述べた変性化合物と同じものが使用できる。
本発明におけるポリアミド、ポリフェニレンエーテル及び衝撃改良材の好ましい量比は、これら３成分の合計を１００重量部としたとき、ポリアミド３０〜７０重量部、ポリフェニレンエーテル２０〜５０重量部、衝撃改良材５〜３０重量部の範囲内である。より好ましくは、ポリアミド４０〜６０重量部、ポリフェニレンエーテル３０〜４０重量部、衝撃改良材５〜１５重量部の範囲内である。
【００５０】
次に本発明で使用することのできる導電性フィラーについて説明する。
本発明で好ましく使用することのできる（Ｄ）成分の導電性フィラーとしては、非導電性材料に導電性を付与する能力を有する有機・無機のフィラーであり、形状は、粒状・板状・フレーク状・繊維状のいずれのものも使用可能である。
その具体例としては、導電性カーボンブラック、カーボンナノチューブに代表される炭素フィブリル、カーボンナノファイバー、炭素繊維、グラファイト等が挙げられる。
【００５１】
これらの中では、導電性カーボンブラック、カーボンナノチューブ、カーボンナノファイバー、がより好ましく使用できる。
本発明で使用できる導電性カーボンブラックとは。ジブチルフタレート（ＤＢＰ）吸油量が２５０ｍｌ／１００ｇ以上のものが好ましく、より好ましくはＤＢＰ吸油量が３００ｍｌ／１００ｇ以上、更に好ましくは３５０ｍｌ／１００ｇ以上のカーボンブラックである。ここで言うＤＢＰ吸油量とは。ＡＳＴＭ　Ｄ２４１４に定められた方法で測定した値である。また、本発明で使用できる導電性カーボンブラックはＢＥＴ表面積が２００ｃｍ^２／ｇ以上のものが好ましく、更には４００ｃｍ^２／ｇ以上のものがより好ましい。市販されているものを例示すると、ケッチェンブラックインターナショナルのケッチェンブラックＥＣやケッチェンブラックＥＣ−６００ＪＤ等が挙げられる。
【００５２】
本発明で使用できるカーボンナノチューブとしては、米国特許４６６３２３０号明細書、米国特許４６６３２３０号明細書、米国特許５１６５９０９号明細書、米国特許５１７１５６０号明細書、米国特許５５７８５４３号明細書、米国特許５５８９１５２号明細書、米国特許５６５０３７０号明細書、米国特許６２３５６７４号明細書等に記載されている繊維径が７５ｎｍ未満で中空構造をした分岐の少ない炭素系繊維を言う。また、１μｍ以下のピッチでらせんが一周するコイル状形状のものも含まれる。市販されているものとしては、ハイペリオンキャタリスト社のハイペリオンが挙げられる。
【００５３】
本発明で使用可能なカーボンナノファイバーとは、繊維径が７５ｎｍ以上で中空構造を有し、分岐構造の多い炭素系繊維を言う。市販品では、昭和電工（株）のＶＧＣＦ、ＶＧＮＦ等が挙げられる。
本発明で使用できる炭素繊維には、ポリアクリロニトリル（ＰＡＮ）あるいはピッチ等を原料とした繊維を不活性ガス雰囲気中で１０００℃〜３５００℃の間の温度で焼成・炭化することにより得られる繊維はすべて包含される。好ましい繊維径は３〜３０μｍであり、より好ましくは５〜２０μｍである。
【００５４】
本発明でのグラファイトとしては、無煙炭・ピッチ等をアーク炉で高温加熱して得られるものはもちろんのこと、天然に産出される石墨も包含される。グラファイトの好ましい重量平均粒径は０．１〜５０μｍの範囲内である。より好ましくは１〜４０μｍの範囲内、最も好ましくは１〜３０μｍの範囲内である。
これら、導電性フィラーの好ましい量は、導電性フィラーを除くすべての成分の量を１００重量部とした際に、０．０１〜５重量部である。より好ましくは０．１〜３重量部である。０．０１重量部未満の量であると、導電性が出なくなる。また、５重量部を越えると、流動性が悪化する。
【００５５】
また、本発明では、組成物の製造の際に相溶化剤を添加しても構わない。相溶化剤を使用する主な目的は、ポリアミド−ポリフェニレンエーテル混合物の物理的性質を改良することである。本発明で使用できる相溶化剤とは、ポリフェニレンエーテル、ポリアミドまたはこれら両者と相互作用する多官能性の化合物を指すものである。
いずれにしても得られるポリアミド−ポリフェニレンエーテル混合物は改良された相溶性を示す事が望ましい。
【００５６】
本発明において使用することのできる相溶化剤の例としては、特許文献６及び特開平９−１２４９２６号公報等に詳細に記載されており、これら公知の相溶化剤はすべて使用可能であり、併用使用も可能である。
これら、種々の相溶化剤の中でも、特に好適な相溶化剤の例としては、マレイン酸、無水マレイン酸、クエン酸が挙げられる。
本発明における相溶化剤の好ましい量は、ポリアミドとポリフェニレンエーテルの混合物１００重量部に対して０．１〜２０重量部であり、より好ましくは０．１〜１０重量部である。
【００５７】
本発明においては、衝撃改良材及びポリフェニレンエーテルと導電性フィラーをあらかじめ溶融混練する事が必須である。
衝撃改良材及びポリフェニレンエーテルとあらかじめ溶融混練する導電性フィラーの量は、使用するすべての導電性フィラーを１００重量％とした際に、０を超えて５０重量％未満の量である。より好ましくは、０．１〜２０重量％、最も好ましくは１〜１０重量％の量である。
【００５８】
本発明において、衝撃改良材及びポリフェニレンエーテルとあらかじめ溶融混練する導電性フィラーのより好ましい添加形態は、ポリフェニレンエーテル、衝撃改良材及びポリアミドから選ばれる１種以上と溶融混練したマスターバッチの形態として添加する方法である。あらかじめマスターバッチの形態にすることにより、成形滞留時の成形片表面外観が改善されるという新たな効果を発現する事ができる。
【００５９】
該マスターバッチ中の好ましい導電性フィラーの比率は、衝撃改良材、ポリフェニレンエーテル及び導電性フィラーの合計量を１００重量％としたときに、５〜２０重量％である。より好ましくは８〜２５重量％である。
該マスターバッチの好ましい製造方法としては、二軸押出機、ニーダーを使用して溶融混練する方法が好ましい。中でも特にポリフェニレンエーテル、衝撃改良材及びポリアミドから選ばれる１種以上が溶融した後に導電性フィラーを添加する方法が好ましく、具体例を挙げると、上流側と下流側にそれぞれ少なくとも１箇所の供給口を有する二軸押出機又はニーダーを使用し、上流側供給口よりポリフェニレンエーテル、衝撃改良材及びポリアミドから選ばれる１種以上を供給し、溶融させた後、下流側供給口より導電性フィラーを添加して溶融混練する方法が挙げられる。
【００６０】
本発明において、衝撃改良材及びポリフェニレンエーテルとあらかじめ溶融混練する導電性フィラーを除く残りの導電性フィラーの全部又は一部は、ポリアミドと同時に添加される事が必須である。
この場合、（１）残りの導電性フィラーすべてをポリアミドとともに添加する方法、（２）残りの導電性フィラーの一部をポリアミドとともに添加し、更に残りの導電性フィラーをポリアミドとポリフェニレンエーテルが溶融混練された後に添加する方法が挙げられるが、本発明においてポリアミドと同時に導電性カーボンブラックが添加されることが必要である。
【００６１】
衝撃改良材及びポリフェニレンエーテルとあらかじめ溶融混練する導電性フィラーを除く残りの導電性フィラーの量は、使用するすべての導電性フィラーを１００重量％とした際に、５０重量％以上１００重量％未満の量である。より好ましくは、８０〜９９．９重量％、最も好ましくは９０〜９９重量％の量である。
上記（１）の残りの導電性フィラーすべてをポリアミドとともに添加する場合は、ポリアミドとあらかじめ溶融混練されたポリアミドマスターバッチの形態で添加する事がより望ましい。この場合の好ましいポリアミドマスターバッチ中の導電性フィラーの濃度は、導電性フィラーが導電性カーボンブラックの場合は５重量％〜１５重量％、導電性フィラーが導電性カーボンブラック以外の場合は１５〜４０重量％の範囲内である。
【００６２】
（２）の残りの導電性フィラーの一部をポリアミドとともに添加し、更に残りの導電性フィラーをポリアミドとポリフェニレンエーテルが溶融混練された後に添加する場合における導電性フィラーの好ましい量比は、［ポリアミドとともに添加する導電性フィラー］／［溶融混練された後に添加する導電性フィラー］比で９０／１０〜１０／９０である。この場合においても、ポリアミドとともに添加する導電性フィラーはポリアミドとのマスターバッチの形態である方が望ましい。
【００６３】
本発明では、上記した成分のほかに、本成分の効果を損なわない範囲で必要に応じて付加的成分を添加しても構わない。
付加的成分の例を以下に挙げる。
ポリエステル、ポリオレフィン等の他の熱可塑性樹脂、無機充填材（タルク、カオリン、ゾノトライト、ワラストナイト、酸化チタン、チタン酸カリウム、ガラス繊維など、）、無機充填材と樹脂との親和性を高める為の公知の密着改良剤、難燃剤（ハロゲン化された樹脂、シリコーン系難燃剤、水酸化マグネシウム、水酸化アルミニウム、有機燐酸エステル化合物、ポリ燐酸アンモニウム、赤燐など）、滴下防止効果を示すフッ素系ポリマー、可塑剤（オイル、低分子量ポリオレフィン、ポリエチレングリコール、脂肪酸エステル類等）及び、三酸化アンチモン等の難燃助剤、カーボンブラック等の着色剤、帯電防止剤、各種過酸化物、酸化亜鉛、硫化亜鉛、酸化防止剤、紫外線吸収剤、光安定剤等である。
【００６４】
これらの成分の具体的な添加量は、ポリアミド、ポリフェニレンエーテル及び、衝撃改良材の合計量１００重量部に対して、合計で１００重量部を越えない範囲である。
本発明の組成物を得るための具体的な加工機械としては、例えば、単軸押出機、二軸押出機、ロール、ニーダー、ブラベンダープラストグラフ、バンバリーミキサー等が挙げられるが、中でも二軸押出機が好ましく、特に、上流側供給口と１カ所以上の下流側供給口を備えた二軸押出機が最も好ましい。
【００６５】
この際の溶融混練温度は特に限定されるものではないが、通常２４０〜３６０℃の中から好適な組成物が得られる条件を任意に選ぶことができる。
本発明の好ましい製造方法は、上流側供給口と１カ所以上の下流側供給口を備えた二軸押出機を用い、（１）上流側供給口より衝撃改良材、ポリフェニレンエーテル及び導電性フィラーの０を超えて５０重量％未満の量を供給し溶融混練した後、下流側供給口よりポリアミドと残りの導電性フィラーのすべてを供給し溶融混練する方法、（２）上流側供給口より衝撃改良材、ポリフェニレンエーテル及び導電性フィラーの０を超えて５０重量％未満の量を供給し溶融混練した後、下流側第一供給口よりポリアミドと残りの導電性フィラーの一部を供給し溶融混練し、下流側第２供給口より残りの導電性フィラーのすべてを供給し、更に溶融混練する方法等が挙げられるが、これらに限定されるものではない。
【００６６】
このようにして得られる本発明の組成物は、従来より公知の種々の方法、例えば、射出成形により各種部品の成形体として成形できる。
これら各種部品としては、例えばＩＣトレー材料、各種ディスクプレーヤー等のシャーシー、キャビネット等の電気・電子部品、各種コンピューターおよびその周辺機器等のＯＡ部品や機械部品、さらにはオートバイのカウルや、自動車のフェンダー・ドアーパネル・フロントパネル・リアパネル・ロッカーパネル・リアバンパーパネル・バックドアガーニッシュ・エンブレムガーニッシュ・燃料注入口パネル・オーバーフェンダー・アウタードアハンドル・ドアミラーハウジング・ボンネンットエアインテーク・バンパー・バンパーガード・ルーフレール・ルーフレールレッグ・ピラー・ピラーカバー・ホイールカバー・スポイラー等に代表される各種エアロパーツ・各種モール・エンブレムといった外装部品や、インストゥルメントパネル・コンソールボックス・トリム等に代表される内装部品等に好適に使用できる。
これらの中でも、静電塗装可能な自動車の外装部品に特に好適に使用可能である。その中でも、特に、衝撃性の要求されるフェンダー用途やサイドドアパネルに最も好ましく使用することができる。
【００６７】
【発明の実施の形態】
以下、本発明を実施例及び比較例により、更に詳細に説明する。
（使用した原料）
（１）ポリフェニレンエーテル（以下、ＰＰＥと略記）
ポリ（２，６−ジメチル−１，４−フェニレンエーテル）
還元粘度：０．４２ｄｌ／ｇ
（２）ポリアミド６６（以下、ＰＡと略記）
数平均分子量：１４，０００
末端アミノ基濃度：３０ミリ当量／ｋｇ
末端カルボキシル基濃度：１１０ミリ当量／ｋｇ
微量安定剤成分としてＣｕＩを３０ｐｐｍ、ＫＩを３５０ｐｐｍ含む
【００６８】
（３）衝撃改良材
（３−１）高分子量ブロック共重合体（以下、ＳＥＢＳ−Ｈ１と略記）
結合形式：ポリスチレン−水素添加ポリブタジエン−ポリスチレン
数平均分子量：２４６，０００
ポリスチレンブロック１個あたりの数平均分子量：４０，６００
結合スチレン量：３３％
１，２−ビニル量：３３％
ポリブタジエン部分の水素添加率：９８％以上
【００６９】
（３−２）低分子量ブロック共重合体−１（以下、ＳＥＢＳ−Ｌ１と略記）
結合形式：ポリスチレン−水素添加ポリブタジエン−ポリスチレン
数平均分子量：９８，５００
ポリスチレンブロック１個あたりの数平均分子量：１４，３００
結合スチレン量：２９％
１，２−ビニル量：３２％
ポリブタジエン部分の水素添加率：９８％以上
【００７０】
（３−３）低分子量ブロック共重合体−２（以下、ＳＥＢＳ−Ｌ２と略記）
結合形式：ポリスチレン−水素添加ポリブタジエン−ポリスチレン
数平均分子量：１１５，０００
ポリスチレンブロック１個あたりの数平均分子量：３４，５００
結合スチレン量：６０％
１，２−ビニル量：３５％
ポリブタジエン部分の水素添加率：９８％以上
【００７１】
（４）導電性フィラー
（４−１）導電性カーボンブラック（以下ＫＢと略記）
商品名：ケッチェンブラックＥＣ−６００ＪＤ（ケッチェンブラックインターナショナル社製）
ＤＢＰ吸油量：４９５ｍｌ／１００ｇ
ＢＥＴ表面積：１２７０ｃｍ^２／ｇ
（４−２）カーボンナノファイバー（以下ＣＮＦと略記）
商品名：ＶＧＣＦ（昭和電工社製）
平均繊維径：８０ｎｍ
平均繊維長：１５μｍ
【００７２】
（５）導電性フィラーマスターバッチ
（５−１）ＰＡ／ＫＢ　マスターバッチ（以下、ＫＢ−ＭＢと略記）
上流側と下流側にそれぞれ１箇所の供給口を備えたＺＳＫ−２５二軸回転押出機［ウェルナー＆フライデラー社製］を用いて、上流側供給口より下流側供給口までを２８０℃、下流側供給口からダイまでを２９０℃に設定し、上流側供給口よりＰＡを９０重量部、下流側供給口よりＫＢを１０重量部供給し、溶融混練し、ＫＢ濃度１０重量％のＰＡ／ＫＢマスターバッチを得た。この時のスクリュー回転数は４００ｒｐｍであった。また、この際上流側供給口とダイの手前に設置した真空吸引可能なベントポートより揮発成分を真空除去した。
【００７３】
（５−２）ＰＡ／ＣＮＦ　マスターバッチ（以下、ＣＮＦ−ＭＢと略記）
ＫＢ−ＭＢ製造時と同じ押出機を同様の温度設定とし上流側供給口よりＰＡを８０重量部、下流側供給口よりＣＮＦを２０重量部供給し、溶融混練し、ＣＮＦ濃度２０重量％のＰＡ／ＣＮＦマスターバッチを得た。この時のスクリュー回転数は４００ｒｐｍであった。また、この際上流側供給口とダイの手前に設置した真空吸引可能なベントポートより揮発成分を真空除去した。
【００７４】
（５−３）ポリアミド６６／ＣＮＴマスターバッチ（以下、ＣＮＴ−ＭＢと略記）
ハイペリオンキャタリスト社製のポリアミド６６／ＣＮＴマスターバッチ（商品名：Ｐｏｌｙａｍｉｄｅ６６　ｗｉｔｈ　Ｆｉｂｒｉｌ　^ＴＭ　Ｎａｎｏｔｕｂｅｓ　ＲＭＢ４６２０−００）を用いた。このマスターバッチ中のＣＮＴ濃度は２０重量％である。
【００７５】
（５−４）ＰＰＥ／ＳＥＢＳ−Ｌ１／ＫＢマスターバッチ（以下ＰＰＥ−ＭＢと略記）
ＫＢ−ＭＢ製造時と同じ押出機を用いて、上流側供給口よりダイまでのすべてを３２０℃に設定し、上流側供給口よりＰＰＥを３０重量部、ＳＥＢＳ−Ｌ１を６０重量部供給し、下流側供給口よりＫＢを１０重量部供給し、ＫＢ濃度１０重量％のＰＰＥ−ＭＢを得た。この時のスクリュー回転数は３００ｒｐｍであった。また、この際上流側供給口とダイの手前に設置した真空吸引可能なベントポートより揮発成分を真空除去した。
（６）相溶化剤：無水マレイン酸（以下。ＭＡＨと略記）
【００７６】
（測定方法）
＜体積固有抵抗（以下ＶＲと略記）＞
厚さ３．２ｍｍの引張試験片（ＡＳＴＭ　Ｄ６３８　タイプＩダンベルバー）の両端を精密カットソーで切断し、長さ５０ｍｍで、両端に均一な断面積（１２．４×３．２ｍｍ）の切断面を持つ、短冊状試験片を得た。この試験片の両端の切断面に銀ペーストを塗布し、充分乾燥させた後、テスターを用いて両端間の抵抗値を、５００Ｖの電圧で測定し、下式を用いて体積固有抵抗として算出した。
ＶＲ＝（Ｒ・ｗ・ｔ）／ｌ
ここで、ＶＲは体積手固有抵抗値（Ω・ｃｍ）、Ｒはテスターで測定した抵抗値（Ω）、ｗは銀ペーストを塗布した部分の幅（ｃｍ）、ｔは銀ペーストを塗布した部分の高さ（ｃｍ）、ｌは銀ペーストを塗布した面間の距離（ｃｍ）である。なお、この測定は１０個の異なる試験片に対して実施し、その加算平均をもって、体積固有抵抗値とした。
【００７７】
＜低温時の高速面衝撃強度（以下低温面衝撃と略記）＞
長さ９０ｍｍ、幅５０ｍｍ、厚み２．５ｍｍの平板状成形片を使用し、グラフィックインパクトテスター［東洋精機製作所社製］を用いて測定した。
試験方法は、平板状試験片を−３０℃に設定した低温恒温槽中に１２０分間静置して充分に冷却した後、素早く取り出し、直径が４０ｍｍのサンプルホールダーに試験片を挟み、先端径が１３ｍｍの球形状のストライカー（重量６．５ｋｇ）を、衝突時の速度が５ｍ／秒になる高さより自由落下させ、試験片を破壊させ、その際の破壊に要した全エネルギー（単位：Ｊ）を測定した。得られたエネルギーを試験片厚みで除して単位厚みあたりの全吸収エネルギー（単位Ｊ／ｃｍ）として表示した。
【００７８】
＜高温剛性（以下、Ｇ’_{（１２０）}と略記）＞
厚さ３．２ｍｍの引張試験片（ＡＳＴＭ　Ｄ６３８　タイプＩ　ダンベルバー）の両端を精密カットソーで切断し、長さ３０ｍｍ、幅１２．４ｍｍの短冊状試験片を得た。得られた試験片の剪断貯蔵弾性率（Ｇ’）をレオメトリクスダイナミックアナライザーＩＩ（ＲＤＡＩＩ　）［レオメトリクスサイエンティフィック社製］で測定した。この時の測定モードは温度掃引モードであり、温度範囲は４０℃〜２５０℃、昇温速度は３℃／分、測定周波数は１０Ｈｚ、歪みは０．２％であった。
この得られた結果での１２０℃における剪断貯蔵弾性率を測定し比較した。
【００７９】
＜耐熱性（以下、ＨＤＴと略記）＞
ＡＳＴＭ　Ｄ６４８に準拠し、荷重１．８２ＭＰａで荷重たわみ温度を測定した。この測定は、異なる１０本の試験片について実施し、その加算平均をもって、ＨＤＴ値とした。
【００８０】
＜流動性（以下、ＳＳＰと略記）＞
射出成形機ＩＳ−８０ＥＰＮ［東芝機械社製］を用いて、射出速度・金型及びシリンダーの温度設定を一定にした時の引張試験片（ＡＳＴＭ　Ｄ６３８　タイプＩダンベルバー）を充填できる最小射出圧力（引張試験片を充填するのに必要な最小の射出圧力）をもって相対比較した。この値は、射出圧力での比較であるので、値が小さい方が流動性に優れることになる。
なお、この時の金型温度は８０℃、シリンダー温度設定はノズルからホッパー側へ２９０℃−２９０℃−２８０℃−２７０℃の設定であった。成形サイクルは射出１０秒，冷却１５秒，インターバル２秒であった。また、少なくとも２０ショットの成形し、金型温度を一定にした後に測定した。
【００８１】
＜成形機滞留時の表面外観（以下、滞留後外観と略記）＞
射出成形機ＩＳ−８０ＥＰＮのシリンダー温度設定をノズルからホッパー側へ３１０℃−３１０℃−３００℃−２９０℃とし、長さ９０ｍｍ、幅５０ｍｍ、厚み２．５ｍｍの平板状成形片を約２０枚成形した後、成形機のサイクルを２分間停止し、樹脂組成物をシリンダー内に滞留させた。その後、成形を開始し、１ショット目の平板状成形片の表面外観を目視で評価した。
成形片の表面全体に銀状痕（シルバー）が現れているものを×、少しでも現れているものを△、全く現れていないものを○とした３段階評価を実施した。
なお、この時の金型温度は８０℃であり、射出圧力は、ＳＳＰの圧力であり、成形サイクルは射出１０秒，冷却１５秒，インターバル２秒であった。
【００８２】
【実施例１〜５及び比較例１，２】
上流側に１箇所と下流側に２箇所（下流側供給口の内、上流側の供給口を下流側第１供給口、下流側の供給口を下流側第２供給口とする）の供給口を有する同方向回転二軸押出機ＺＳＫ−４０［ウェルナー＆フライデラー社製］のシリンダー温度を上流側供給口より第１下流側供給口までを３２０℃、第１下流側供給口よりダイまでを２８０℃に設定し、上流側供給口及び第１下流側供給口より表１記載の割合でそれぞれ供給し、溶融混練し、ペレット化した。
【００８３】
なお、この時のスクリュー回転数は３００ｒｐｍであり、また、揮発成分の除去のため第１下流側供給口とダイの手前の２箇所で真空吸引を実施した。
得られたペレットを、ＩＳ−８０ＥＰＮ成形機にて各種試験片に射出成形した。この際にＳＳＰを同時に測定した。得られた試験片を用いて、体積抵抗・ＨＤＴ・低温面衝撃・高温剛性を測定した。各物性値は、表１に併記した。
同じ導電性フィラー配合量であっても、上流側供給口より導電性フィラーを少量添加する事で、体積固有抵抗と低温面衝撃を同時に向上させている事が判り、その傾向を見ると、上流側供給口からの導電性フィラー添加なしと少量配合との間に明らかな臨界点があることが判る。
【００８４】
【実施例６〜８】
各供給口より表２記載の割合で供給した以外はすべて実施例１と同様に実施した。各物性値は、表２に併記した。
実施例２と７を比較すると、衝撃改良材に高分子量ブロック共重合体と低分子量ブロック共重合体を併用する事により、低温面衝撃が向上することが判る。
また、低分子量ブロック共重合体としてポリスチレンブロックの分子量が充分にあり、結合スチレン量の大きいブロック共重合体を用いた実施例６は、実施例２に比較して、高温剛性とＨＤＴが大幅に向上していることが判る。
さらに、低分子量ブロック共重合体を結合スチレン量の異なる２種のブレンドとした実施例８では、実施例２，６及び７に比較して、流動性が大幅に向上していることが判る。
【００８５】
【実施例９及び比較例３】
各供給口より表３記載の割合で供給した以外はすべて実施例１と同様に実施した。各物性値は、表３に併記した。
ここでも、上流側供給口より少量の導電性フィラーを添加する方が、何も添加しない比較例３に比べて、体積固有抵抗と低温面衝撃が向上する事が判る。
【００８６】
【実施例１０】
各供給口より、表４記載の割合で供給した以外はすべて実施例１と同様に実施した。各物性値は、表４に併記した。
本発明の組成物は、上流側供給口より添加する導電性フィラーを除く残りの導電性フィラーをさらに分割して供給しても体積固有抵抗と低温面衝撃のバランスに優れる事が判る。
【００８７】
【実施例１１、１２】
上流側供給口、及び下流側第１供給口より、表５記載の割合で供給した以外はすべて実施例１と同様に実施した。なお、この成形の際、成形機滞留時の表面外観を同時に測定した。各物性値は、表５に併記した。
衝撃改良材及びポリフェニレンエーテルとあらかじめ溶融混練する導電性フィラーの添加形態を、マスターバッチの形態に変更することにより、他の物性は保持したまま、成形機滞留時の表面外観を飛躍的に向上できることが判る。
【００８８】
【表１】

【００８９】
【表２】

【００９０】
【表３】

【００９１】
【表４】

【００９２】
【表５】

【００９３】
【発明の効果】
本発明の組成物は、導電性フィラーの添加位置と添加比率を最適化することにより、導電性（体積固有抵抗）と低温面衝撃強度を同時に改善し得る、樹脂組成物・その製法及びそれからなる成形体である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a resin composition having excellent balance between conductivity and high-speed surface impact strength at low temperature, high-temperature rigidity, heat resistance and fluidity, a method for producing the same, and a molded product thereof.
The composition of the present invention can be used in a wide range of fields such as electric / electronic parts, OA parts, vehicle parts, and mechanical parts, and can be suitably used especially for automobile exterior parts that can be electrostatically coated. Among them, it can be most preferably used for fender applications and side door panels that require impact resistance.
[0002]
[Prior art]
Polyphenylene ether is used in a wide range of applications because of its excellent mechanical properties, electrical properties, and heat resistance, and also has excellent dimensional stability.However, it is inferior in molding processability by itself. A technique for blending a polyamide has been proposed in Patent Document 1, and has become a material used for a very wide variety of applications at present.
Recently, the use of polyamide-polyphenylene ether alloys for use in exterior materials (such as fenders and door panels) of automobiles, which is capable of imparting conductivity to electrostatic coating and which can be electrostatically coated, is rapidly advancing.
As a technique for imparting conductivity to a polyamide-polyphenylene ether alloy, for example, Patent Literature 2 discloses a technique in which carbon black is mainly contained in a polyamide phase to lower the surface resistance value. Patent Document 3 discloses a technique in which a composition comprising a polyamide, polyphenylene ether, and carbon black is excellent in volume resistivity, fluidity, heat resistance, and impact strength.
[0003]
Patent Literatures 4 and 5 disclose compositions containing conductive carbon fibrils and having excellent impact strength and volume resistivity. Patent Literature 6 discloses that a polyamide and polyphenylene ether are made compatible with each other. A technique is disclosed in which a composition excellent in impact strength and volume resistivity can be obtained by blending conductive carbon black after the addition.
Further, Patent Document 7 discloses a composition excellent in drop impact strength and conductivity by using a plurality of polyamides and conductive carbon black, and Patent Document 8 discloses an amount of a compatibilizing agent. A technique whereby a composition having excellent conductivity is obtained by limiting the amount to a specific amount is disclosed.
[0004]
Patent Document 9 discloses a technique in which a composition comprising polyphenylene ether, polyamide, talc, and carbon is excellent in conductivity, fluidity, and notched Izod impact strength.
Patent Document 10 by the same applicant as the present invention discloses that the presence of a conductive filler in the polyphenylene ether phase is excellent in suppressing conductivity, fluidity, linear expansion coefficient, impact strength, and generation of chips. The technology is disclosed.
[0005]
However, even with the technology described above, if the conductivity is improved to the level required for electrostatic coating, the problem is that high-speed surface impact strength at low temperatures is deteriorated, resulting in poor practicality. Has begun to be.
When imparting impact resistance to a resin composition, generally, an impact modifier is added. As an example, Patent Literature 11 and Patent Literature 12 disclose a technique for improving impact resistance by blending two types of elastomers, an ABA-type triblock copolymer and an AB-type diblock copolymer. I have. Further, Patent Document 13 discloses a technique for improving moldability, mechanical properties, and heat resistance by blending a plurality of block copolymers having different weight ratios of aromatic vinyl compound blocks.
[0006]
However, these technologies do not consider the addition of conductive fillers, and the fact that the addition of conductive fillers rapidly reduces the high-speed surface impact strength at low temperatures and makes them unpractical. It is.
The above-mentioned problems of compatibility between conductivity and high-speed surface impact strength at low temperatures cannot be sufficiently solved only by the combination of the conventional technologies. Therefore, the development of new technologies is expected. It was the current situation.
[0007]
[Patent Document 1]
Japanese Patent Publication No. 45-997 (page 1 claims)
[Patent Document 2]
JP-A-2-201811 (Claim 1 page 1)
[Patent Document 3]
JP-A-4-300296 (Claim 1)
[Patent Document 4]
JP-A-8-508534 (page 2 claim 1)
[Patent Document 5]
U.S. Pat. No. 5,643,502 (18th paragraph, claim 1)
[Patent Document 6]
Japanese Patent Application Laid-Open No. 8-48869 (page 2 claim 7)
[Patent Document 7]
Japanese Patent Application Laid-Open No. 10-310695 (page 2 claim 1)
[Patent Document 8]
U.S. Pat. No. 6,221,283 (8th paragraph, claim 1)
[Patent Document 9]
WO 2001/36536 pamphlet (page 23, claim 1)
[Patent Document 10]
WO 2001/81473 pamphlet (page 43, claim 1)
[Patent Document 11]
JP-A-64-81852 (Claim 1 page 1)
[Patent Document 12]
Japanese Patent Application Laid-Open No. 2-58563 (first page, claim 1)
[Patent Document 13]
JP-A-6-240130 (First page claim 2)
[0008]
[Problems to be solved by the invention]
An object of the present invention is to simultaneously achieve these problems (both conductivity and low-temperature surface impact strength) of the polyamide / polyphenylene ether alloy.
[0009]
[Means for Solving the Problems]
The present inventors have conducted a study to solve the above-mentioned problems, and as a result, a resin composition in which a small amount of all conductive fillers used surprisingly and a mixture containing an impact modifier and polyphenylene ether are previously melt-kneaded. The inventors have found that the conductivity and the high-speed surface impact strength at low temperatures can be simultaneously improved, and have reached the present invention.
That is, the present invention
A resin composition comprising (A) a polyamide, (B) a polyphenylene ether, (C) an impact modifier, and (D) a conductive filler,
Step a: a step of melt-kneading the components (B), (C) and (D);
Step b: a step of melt-kneading all or a part of the component (A) and the component (D);
Step c A step of melt-kneading the composition obtained in Step a and the composition obtained in Step b, and if necessary, the remaining component (A).
And the amount of the component (D) in step a is more than 0 and less than 50% by weight when all the components (D) are 100% by weight.
[0010]
The present invention also provides a method for producing a conductive resin composition, characterized in that more than 0 and less than 50% by weight of all the conductive fillers to be used are previously melt-kneaded with a mixture containing an impact modifier and polyphenylene ether. And a molded article for automobile exteriors comprising the composition.
Next, each component that can be used in the present invention will be described in detail.
As the kind of the polyamide as the component (A) that can be used in the present invention, any polyamide having an amide bond {—NH—C (＝ O) —} in the polymer main chain can be used. it can.
[0011]
Generally, polyamide is a ring-opening polymerization of lactams. It is obtained by polycondensation of a diamine and a dicarboxylic acid, polycondensation of an aminocarboxylic acid, and the like, but is not limited thereto.
The diamines are roughly classified into aliphatic, alicyclic, and aromatic diamines. Specific examples include tetramethylene diamine, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, tridecamethylene diamine, and 2,2. , 4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 5-methylnanomethylenediamine, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, m-phenylenediamine, p -Phenylenediamine, m-xylylenediamine, p-xylylenediamine.
[0012]
The dicarboxylic acids are roughly classified into aliphatic, alicyclic, and aromatic dicarboxylic acids. Specific examples thereof include adipic acid, suberic acid, azelaic acid, sebacic acid, dodecandioic acid, and 1,1,3-tridecane. Examples thereof include diacid, 1,3-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and dimer acid.
Specific examples of lactams include ε-caprolactam, enantholactam, ω-laurolactam and the like.
[0013]
Examples of the aminocarboxylic acid include ε-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and 13-aminotricarboxylic acid. Decanoic acid and the like.
In the present invention, any of the copolyamides obtained by polycondensing these lactams, diamines, dicarboxylic acids, and ω-aminocarboxylic acids alone or as a mixture of two or more thereof can be used.
Also, those obtained by polymerizing these lactams, diamines, dicarboxylic acids, and ω-aminocarboxylic acids to a low molecular weight oligomer stage in a polymerization reactor and increasing the molecular weight by an extruder or the like can be suitably used.
[0014]
Particularly useful polyamide resins useful in the present invention include aliphatic polyamides such as polyamide 6, polyamide 66, polyamide 46, polyamide 11, polyamide 12, polyamide 610, polyamide 612, and poly (met-xylylene adipamide). (Sometimes abbreviated as MXD6 nylon), poly (hexamethylene isophthalamide) (hereinafter sometimes abbreviated as 6I nylon), poly (nonamethylene terephthalamide) (hereinafter sometimes abbreviated as 9T nylon), poly (tetramethylene) Examples thereof include aliphatic-aromatic polyamides such as isophthalamide (hereinafter sometimes abbreviated as 4T nylon) and copolymers and mixtures thereof. Further, polyamides obtained by copolymerizing a plurality of polyamides with an extruder or the like can also be used. Preferred polyamides are polyamide 6, polyamide 66, copolymers of polyamide 6 and polyamide 66 and mixtures thereof, most preferably polyamide 66.
[0015]
The preferred number average molecular weight of the polyamide resin used in the present invention is from 5,000 to 100,000, and more preferably from 10,000 to 30,000.
The polyamide resin in the present invention is not limited to these, and may be a mixture of a plurality of polyamide resins having different molecular weights. For example, a mixture of a low molecular weight polyamide having a number average molecular weight of 10,000 or less and a high molecular weight polyamide having a number average molecular weight of 10,000 or less, and a mixture of a low molecular weight polyamide having a number average molecular weight of 10,000 or less and a general polyamide having a number of about 15,000. It is.
[0016]
The end groups of the polyamide participate in the reaction with the polyphenylene ether. Polyamide resins generally have amino groups and carboxyl groups as terminal groups. Generally, when the concentration of carboxyl groups increases, impact resistance generally decreases, fluidity improves, and conversely, amino group concentration increases. The higher the value, the higher the impact resistance and the lower the fluidity.
In the present application, these preferred ratios are 9/1 to 1/9, more preferably 8/2 to 1/9, even more preferably 6/4 to 1/9 in terms of amino group / carboxyl group concentration ratio. .
[0017]
The concentration of the terminal amino group is preferably at least 10 meq / kg. It is more preferably at least 30 meq / kg.
As a method for adjusting the terminal groups of these polyamide resins, a known method that is apparent to those skilled in the art can be used. For example, a method of adding a diamine, a dicarboxylic acid, a monocarboxylic acid, or the like so as to have a predetermined terminal concentration at the time of polymerization of the polyamide resin may be mentioned.
[0018]
In addition, a metal-based stabilizer described in JP-A-1-163262, which is known for the purpose of improving the heat resistance of a polyamide resin, can be used without any problem.
Among these metal-based stabilizers, particularly preferably used are CuI, CuCl ₂ , Copper acetate, cerium stearate and the like. Further, alkyl metal halides represented by potassium iodide, potassium bromide and the like can also be suitably used. These may of course be added in combination.
[0019]
The preferable blending amount of the metal-based stabilizer and / or the halogenated salt of the alkyl metal is 0.001 to 1 part by weight based on 100 parts by weight of the polyamide resin in total.
Further, in addition to the above, known additives that can be added to the polyamide may be added in an amount of less than 10 parts by weight based on 100 parts by weight of the polyamide.
The polyphenylene ether of the component (B) that can be used in the present invention is a homopolymer and / or a copolymer composed of the structural unit of the formula (1).
[0020]
Embedded image

[0021]
[In the formula, O is an oxygen atom, and R is each independently hydrogen, halogen, primary or secondary lower alkyl, phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy, or halohydrocarbonoxy (however, At least two carbon atoms separating a halogen atom and an oxygen atom). ]
[0022]
Specific examples of the polyphenylene ether of the present invention include, for example, poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), (2-methyl-6-phenyl-1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether), and the like, and 2,6-dimethylphenol and other phenols. (For example, copolymers with 2,3,6-trimethylphenol and copolymers with 2-methyl-6-butylphenol as described in JP-B-52-17880). A polyphenylene ether copolymer is also included.
[0023]
Of these, particularly preferred polyphenylene ethers include poly (2,6-dimethyl-1,4-phenylene ether), a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, or a copolymer thereof. It is a mixture.
The method for producing the polyphenylene ether used in the present invention is not particularly limited as long as it can be obtained by a known method. For example, U.S. Pat. Nos. 3,306,874, 3,306,875 and 3,257,357. No. 3,257,358, JP-A-50-51197, JP-A-63-152628, and the like.
[0024]
The reduced viscosity (η) of the polyphenylene ether that can be used in the present invention _{sp / c} : 0.5 g / dl, chloroform solution, measured at 30 ° C) is preferably in the range of 0.15 to 0.70 dl / g, more preferably in the range of 0.20 to 0.60 dl / g, more preferably Is in the range of 0.40 to 0.55 dl / g.
In the present invention, a blend of two or more polyphenylene ethers having different reduced viscosities can be used without any problem. For example, a mixture of a polyphenylene ether having a reduced viscosity of 0.45 dl / g or less and a polyphenylene ether having a reduced viscosity of 0.50 dl / g or more, a low molecular weight polyphenylene ether having a reduced viscosity of 0.40 dl / g or less, and a reduced viscosity of 0.50 dl / g or more But of course, the invention is not limited thereto.
[0025]
In the polyphenylene ether usable in the present invention, the organic solvent derived from the polymerization solvent may remain in an amount of less than 5% by weight based on 100 parts by weight of the polyphenylene ether. It is difficult to completely remove the organic solvent resulting from the polymerization solvent in the drying step after the polymerization, and usually the organic solvent remains in the range of several hundred ppm to several%. Examples of the organic solvent caused by the polymerization solvent include at least one of toluene, xylene isomers, ethylbenzene, C1-5 alcohols, chloroform, dichloromethane, chlorobenzene, and dichlorobenzene.
[0026]
Further, the polyphenylene ether which can be used in the present invention may be a polyphenylene ether which is wholly or partially modified.
The modified polyphenylene ether as used herein means at least one carbon-carbon double bond or triple bond and at least one carboxylic acid group, acid anhydride group, amino group, hydroxyl group, or glycidyl in the molecular structure. Refers to a polyphenylene ether modified with at least one modifying compound having a group.
[0027]
The method for producing the modified polyphenylene ether includes: (1) a modified compound without melting the polyphenylene ether at a temperature in the range of 100 ° C. or more and less than the glass transition temperature of the polyphenylene ether in the presence or absence of a radical initiator; (2) a method of melt-kneading and reacting with a modified compound at a temperature in the range of the glass transition temperature of polyphenylene ether to 360 ° C. or less in the presence or absence of a radical initiator, and (3) a radical initiator. In the presence or absence of a polyphenylene ether in a solution at a temperature lower than the glass transition temperature of the polyphenylene ether in the absence of a modified compound, and any of these methods may be used. The method (2) is preferred.
[0028]
Next, at least one modified compound having at least one carbon-carbon double bond or triple bond and at least one carboxylic acid group, acid anhydride group, amino group, hydroxyl group, or glycidyl group in the molecular structure. Is specifically described.
Examples of the modified compound having a carbon-carbon double bond, a carboxylic acid group, and an acid anhydride group in the molecule include maleic acid, fumaric acid, chloromaleic acid, cis-4-cyclohexene-1,2-dicarboxylic acid, and the like. Acid anhydrides and the like. Particularly, fumaric acid, maleic acid and maleic anhydride are preferable, and fumaric acid and maleic anhydride are particularly preferable.
[0029]
Further, those in which one or two carboxyl groups of the carboxyl groups of these unsaturated dicarboxylic acids are esters can also be used.
Examples of the modified compound having both a carbon-carbon double bond and a glycidyl group in the molecule include allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, and epoxidized natural fats and oils.
Of these, glycidyl acrylate and glycidyl methacrylate are particularly preferred.
[0030]
Examples of the modified compound having both a carbon-carbon double bond and a hydroxyl group in the molecule include general formula C such as allyl alcohol, 4-penten-1-ol and 1,4-pentadien-3-ol. _n H _2n-3 OH (n is a positive integer) unsaturated alcohol represented by the general formula C _n H _2n-5 OH, C _n H _2n-7 And unsaturated alcohols such as OH (n is a positive integer).
The above-mentioned modifying compounds may be used alone or in combination of two or more.
[0031]
The amount of the modified compound to be added when producing the modified polyphenylene ether is preferably 0.1 to 10 parts by weight, more preferably 0.3 to 5 parts by weight, per 100 parts by weight of the polyphenylene ether.
The preferred amount of the radical initiator when producing the polyphenylene ether modified with the radical initiator is 0.001 to 1 part by weight based on 100 parts by weight of the polyphenylene ether.
[0032]
Further, the addition rate of the modified compound in the modified polyphenylene ether is preferably 0.01 to 5% by weight. More preferably, it is 0.1 to 3% by weight.
In the modified polyphenylene ether, an unreacted modified compound and / or a polymer of the modified compound may remain.
Further, in order to reduce the amount of the modified compound and / or the polymer of the modified compound remaining in the modified polyphenylene ether, when producing the modified polyphenylene ether, an amide bond and / or Alternatively, a compound having an amino group may be added.
[0033]
The compound having an amide bond as referred to herein is a compound having an amide bond {-NH-C (= O)-} structure in a molecular structure, and a compound having an amino group is a compound having {-NH ₂ 化合物 A compound having a structure. Specific examples of these compounds include aliphatic amines such as octylamine, nonylamine, tetramethylenediamine, hexamethylenediamine, aniline, m-phenylenediamine, p-phenylenediamine, m-xylylenediamine, and p-xylylenediamine. But not limited thereto, such as aromatic amines such as the above, reaction products of the above amines with carboxylic acids and dicarboxylic acids, lactams such as ε-caprolactam, and polyamide resins.
[0034]
A preferable addition amount of the compound having an amide bond or an amino group is 0.001 part by weight or more and less than 5 parts by weight based on 100 parts by weight of polyphenylene ether. Preferably it is 0.01 part by weight or more and less than 1 part by weight, more preferably 0.01 part by weight or more and less than 0.1 part by weight.
In the present invention, the styrene-based thermoplastic resin may be blended in an amount of less than 50 parts by weight based on 100 parts by weight of the total of polyamide and polyphenylene ether.
[0035]
Examples of the styrene-based thermoplastic resin used in the present invention include homopolystyrene, rubber-modified polystyrene (HIPS), styrene-acrylonitrile copolymer (AS resin), styrene-rubber polymer-acrylonitrile copolymer (ABS resin), and the like. No.
Further, known additives which can be added to the polyphenylene ether may be added in an amount of less than 10 parts by weight based on 100 parts by weight of the polyphenylene ether.
[0036]
Next, the impact modifier of the component (C) that can be used in the present invention will be described.
The impact modifier that can be used in the present invention is an aromatic vinyl compound-conjugated diene compound block copolymer composed of a polymer block mainly containing an aromatic vinyl compound and a polymer block mainly containing a conjugated diene compound. At least one selected from the group consisting of coalesced products, hydrogenated products thereof, and ethylene-α-olefin copolymers.
[0037]
Specific examples of the aromatic vinyl compound that can be used in the aromatic vinyl compound-conjugated diene compound block copolymer in the present invention include styrene, α-methylstyrene, vinyltoluene, and the like. More than one kind of compound is used, and styrene is particularly preferable.
Specific examples of the conjugated diene compound include butadiene, isoprene, piperylene, 1,3-pentadiene and the like, and one or more compounds selected from these are used. Among them, butadiene, isoprene and a combination thereof are used. Is preferred.
[0038]
The microstructure of the soft segment part of the conjugated diene compound of the block copolymer is preferably such that the 1,2-vinyl content or the total amount of the 1,2-vinyl content and the 3,4-vinyl content is 5 to 80%. It is preferably from 10 to 50%, most preferably from 10 to 40%.
In the block copolymer of the present invention, a polymer block [A] mainly composed of an aromatic vinyl compound and a polymer block [B] mainly composed of a conjugated diene compound are AB type, ABA type, It is preferable that the block copolymer has a bonding mode selected from the ABAB type.
[0039]
Among these, the ABA type and the ABAB type are more preferable. These may of course be mixtures.
Further, the block copolymer of the aromatic vinyl compound and the conjugated diene compound that can be used in the present invention is more preferably a hydrogenated block copolymer. The hydrogenated block copolymer is obtained by subjecting the above-described block copolymer of an aromatic vinyl compound and a conjugated diene compound to hydrogenation treatment, thereby forming an aliphatic double bond of a polymer block mainly composed of a conjugated diene compound. Is controlled in a range of more than 0 to 100%. The preferred hydrogenation rate of the hydrogenated block copolymer is 50% or more, more preferably 80% or more, and most preferably 98% or more.
[0040]
These block copolymers can be used without any problem as a mixture of a non-hydrogenated block copolymer and a hydrogenated block copolymer.
In the present invention, by using a mixture of a low molecular weight impact modifier and a high molecular weight impact modifier as the impact modifier to be used, it is possible to further improve the high-speed surface impact strength at low temperatures.
Specifically, a mixture of a low molecular weight impact modifier having a number average molecular weight of less than 120,000 and a high molecular weight impact modifier having a number average molecular weight of 120,000 or more is desirable.
[0041]
The number average molecular weight referred to in the present invention is measured by an ultraviolet spectrophotometer [UV-41: manufactured by Showa Denko KK] using a gel permeation chromatography measuring device [GPC SYSTEM21: manufactured by Showa Denko KK]. And the number average molecular weight in terms of standard polystyrene. [Solvent: chloroform, temperature: 40 ° C., column: sample side (KG, K-800RL, K-800R), reference side (K-805L × 2), flow rate 10 ml / min, measurement wavelength: 254 nm, pressure 15-17kg / cm ² ). At this time, a low molecular weight component may be detected due to deactivation of the catalyst during polymerization. In such a case, the low molecular weight component is not included in the molecular weight calculation. Usually, the calculated correct molecular weight distribution (weight average molecular weight / number average molecular weight) is in the range of 1.0 to 1.1.
[0042]
The weight ratio of the low molecular weight block copolymer to the high molecular weight block copolymer is low molecular weight block copolymer / high molecular weight block copolymer = 95/5 to 5/95. Preferably it is 90/10 to 10/90.
Further, in the present invention, as the low molecular weight block copolymer, a block copolymer having a number average molecular weight of 20,000 or more of one polymer block mainly composed of an aromatic vinyl compound is further used. An additional effect of improving rigidity at high temperatures can be obtained.
[0043]
The number average molecular weight of one polymer block mainly composed of an aromatic vinyl compound can be determined by the following equation using the number average molecular weight of the above-described block copolymer.
Mn _(A) = {Mn × a / (a + b)} / N
[In the above formula, Mn _(A) Is the number average molecular weight of one polymer block mainly composed of an aromatic vinyl compound, Mn is the number average molecular weight of the block copolymer, and a is a polymer mainly composed of all the aromatic vinyl compounds in the block copolymer. The weight% of the block, b is the weight% of the polymer block mainly composed of all the conjugated diene compounds in the block copolymer, and N is the weight percentage of the polymer block mainly composed of the aromatic vinyl compound in the block copolymer. Represents a number. ]
[0044]
Further, in the present invention, the preferable range of the content of the polymer block mainly composed of the aromatic vinyl compound of the low molecular weight block copolymer is 55% by weight or more and less than 90% by weight. By using a block copolymer having an aromatic vinyl polymer block in this range for the low molecular weight block copolymer, heat resistance can be improved, and thus the block copolymer can be used more preferably.
Further, in the present invention, a block copolymer containing a low molecular weight block copolymer in an amount of 55% by weight or more and less than 90% by weight of a polymer block mainly composed of an aromatic vinyl compound, and an aromatic vinyl compound. By forming a mixture with a block copolymer containing the main polymer block in an amount of 20% by weight or more and less than 55% by weight, the fluidity can be improved.
Further, in the block copolymer of the present invention, a mixture obtained by previously mixing an oil containing paraffin as a main component may be used. By preliminarily mixing an oil containing paraffin as a main component, the processability of the resin composition can be improved.
[0045]
In this case, the preferred amount of the oil containing paraffin as a main component is 1 to 70 parts by weight based on 100 parts by weight of the block copolymer. If it is mixed in an amount of 70 parts by weight or more, handleability is poor.
The oil containing paraffin as a main component here is an aromatic ring-containing compound, a naphthene ring-containing compound, and a mixture of hydrocarbon compounds having a weight average molecular weight in the range of 500 to 10,000 in which the three of the paraffin compounds are combined. And the content of the paraffinic compound is 50% by weight or more.
[0046]
More preferably, the paraffinic compound is 50 to 90% by weight, the naphthene ring-containing compound is 10 to 40% by weight, and the aromatic ring-containing compound is 5% by weight or less.
These oils containing paraffin as a main component are commercially available, and include, for example, PW380 manufactured by Idemitsu Kosan Co., Ltd.
These aromatic vinyl compound-conjugated diene compound block copolymers may be different in bonding type, different aromatic vinyl compound types, different conjugated diene compound types, 1, Those having different 2-bonded vinyl content or 1,2-bonded vinyl content and 3,4-bonded vinyl content, different aromatic vinyl compound component contents, different hydrogenation rates, and the like are used in combination. It does not matter.
[0047]
As the ethylene-α-olefin copolymer that can be used in the present invention, the ethylene-α-olefin copolymer described in JP-A-2001-302911 can be used.
Further, the impact modifier used in the present invention may be an impact modifier which is wholly or partially modified.
The modified impact modifier herein means at least one carbon-carbon double bond or triple bond and at least one carboxylic acid group, acid anhydride group, amino group, hydroxyl group, or Refers to an impact modifier modified with at least one modifying compound having a glycidyl group.
[0048]
The method for producing the modified impact modifier is as follows: (1) In the presence or absence of a radical initiator, melt-knead with the modifying compound at a temperature in the range of the softening point temperature of the impact modifier to 250 ° C. or less to cause a reaction. A method, (2) a method in which an impact modifier and a modifying compound are reacted in a solution at a temperature equal to or lower than the softening point of the impact modifier in the presence or absence of a radical initiator, and (3) in the presence of a radical initiator. A method in which the impact modifier is reacted with the modifying compound at a temperature equal to or lower than the softening point of the impact modifier in the absence of the impact modifier without melting, and any of these methods may be used. More preferably, among (1), the method performed in the presence of a radical initiator is most preferable.
[0049]
At least one kind of modification having at least one carbon-carbon double bond or triple bond and at least one carboxylic acid group, acid anhydride group, amino group, hydroxyl group, or glycidyl group in the molecular structure referred to herein. As the compound, the same compounds as those described for the modified polyphenylene ether can be used.
Preferred amounts of the polyamide, polyphenylene ether and impact modifier in the present invention are, when the total of these three components is 100 parts by weight, 30 to 70 parts by weight of polyamide, 20 to 50 parts by weight of polyphenylene ether, 5 to 5 parts of impact modifier. It is in the range of 30 parts by weight. More preferably, it is in the range of 40 to 60 parts by weight of polyamide, 30 to 40 parts by weight of polyphenylene ether, and 5 to 15 parts by weight of impact modifier.
[0050]
Next, the conductive filler that can be used in the present invention will be described.
The conductive filler of the component (D) which can be preferably used in the present invention is an organic or inorganic filler having a capability of imparting conductivity to a non-conductive material, and has a granular, plate-like, or flake shape. Any of a shape and a fiber shape can be used.
Specific examples thereof include conductive carbon black, carbon fibrils represented by carbon nanotubes, carbon nanofibers, carbon fibers, and graphite.
[0051]
Among them, conductive carbon black, carbon nanotube, and carbon nanofiber can be more preferably used.
What is conductive carbon black that can be used in the present invention? Preferably, the carbon black has a dibutyl phthalate (DBP) oil absorption of 250 ml / 100 g or more, more preferably 300 ml / 100 g or more, even more preferably 350 ml / 100 g or more. What is DBP oil absorption here? This is a value measured by a method specified in ASTM D2414. The conductive carbon black that can be used in the present invention has a BET surface area of 200 cm. ² / G or more, more preferably 400 cm ² / G or more is more preferable. Examples of commercially available products include Ketjen Black EC and Ketjen Black EC-600JD of Ketjen Black International.
[0052]
Examples of carbon nanotubes usable in the present invention include U.S. Pat. No. 4,663,230, U.S. Pat. No. 4,663,230, U.S. Pat. No. 5,165,909, U.S. Pat. , US Pat. No. 5,650,370, US Pat. No. 6,235,674, etc., which have a fiber diameter of less than 75 nm and have a hollow structure with few branches. In addition, a coil-shaped member in which a spiral makes a round at a pitch of 1 μm or less is also included. Commercially available products include Hyperion manufactured by Hyperion Catalyst.
[0053]
The carbon nanofiber that can be used in the present invention refers to a carbon fiber having a fiber diameter of 75 nm or more, having a hollow structure, and having many branched structures. Commercially available products include VGCF and VGNF of Showa Denko KK.
The carbon fibers usable in the present invention include fibers obtained by calcining and carbonizing fibers made of polyacrylonitrile (PAN) or pitch at a temperature between 1000 ° C and 3500 ° C in an inert gas atmosphere. All included. A preferred fiber diameter is 3 to 30 μm, more preferably 5 to 20 μm.
[0054]
The graphite in the present invention includes not only those obtained by heating anthracite, pitch and the like in an arc furnace at a high temperature, but also graphite produced naturally. The preferred weight average particle size of graphite is in the range of 0.1 to 50 μm. More preferably, it is in the range of 1 to 40 μm, most preferably in the range of 1 to 30 μm.
The preferable amount of these conductive fillers is 0.01 to 5 parts by weight when the amount of all components except the conductive filler is 100 parts by weight. More preferably, it is 0.1 to 3 parts by weight. If the amount is less than 0.01 part by weight, conductivity will not be obtained. If it exceeds 5 parts by weight, the fluidity deteriorates.
[0055]
In the present invention, a compatibilizer may be added during the production of the composition. The main purpose of using the compatibilizer is to improve the physical properties of the polyamide-polyphenylene ether mixture. The compatibilizer that can be used in the present invention refers to a polyfunctional compound that interacts with polyphenylene ether, polyamide, or both.
In any event, the resulting polyamide-polyphenylene ether mixture desirably exhibits improved compatibility.
[0056]
Examples of the compatibilizer that can be used in the present invention are described in detail in Patent Document 6 and JP-A-9-124926, and all of these known compatibilizers can be used. Use is also possible.
Among these various compatibilizers, examples of particularly suitable compatibilizers include maleic acid, maleic anhydride, and citric acid.
The preferred amount of the compatibilizer in the present invention is 0.1 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the mixture of polyamide and polyphenylene ether.
[0057]
In the present invention, it is essential to previously melt-knead the impact modifier, the polyphenylene ether, and the conductive filler.
The amount of the conductive filler to be melt-kneaded with the impact modifier and the polyphenylene ether in advance is an amount of more than 0 and less than 50% by weight when all the conductive fillers used are 100% by weight. More preferably, it is in an amount of 0.1-20% by weight, most preferably 1-10% by weight.
[0058]
In the present invention, a more preferable addition form of the conductive filler which is previously melt-kneaded with the impact modifier and the polyphenylene ether is added in the form of a master batch melt-kneaded with at least one selected from polyphenylene ether, the impact modifier and polyamide. Is the way. By adopting the form of a master batch in advance, a new effect of improving the appearance of the surface of the molded piece when the molding stays can be exhibited.
[0059]
The preferable ratio of the conductive filler in the masterbatch is 5 to 20% by weight when the total amount of the impact modifier, polyphenylene ether and the conductive filler is 100% by weight. More preferably, it is 8 to 25% by weight.
As a preferable production method of the master batch, a method of melt-kneading using a twin-screw extruder and a kneader is preferable. Among them, a method of adding a conductive filler after at least one selected from polyphenylene ether, an impact modifier and a polyamide is melted is preferable. To be specific, at least one supply port is provided on each of the upstream side and the downstream side. Using a twin-screw extruder or kneader having, supply at least one selected from polyphenylene ether, impact modifier and polyamide from the upstream supply port, and after melting, add a conductive filler from the downstream supply port. And melt-kneading.
[0060]
In the present invention, it is essential that all or part of the remaining conductive fillers other than the impact modifier and the conductive filler previously melt-kneaded with the polyphenylene ether be added simultaneously with the polyamide.
In this case, (1) a method in which all of the remaining conductive filler is added together with the polyamide, (2) a part of the remaining conductive filler is added together with the polyamide, and the remaining conductive filler is melt-kneaded with polyamide and polyphenylene ether. A method of adding the conductive carbon black after the addition is mentioned. In the present invention, it is necessary that the conductive carbon black is added simultaneously with the polyamide.
[0061]
The amount of the remaining conductive filler excluding the impact modifier and the conductive filler previously melt-kneaded with polyphenylene ether is 50% by weight or more and less than 100% by weight when all the conductive fillers used are 100% by weight. Quantity. More preferably, it is in an amount of 80-99.9% by weight, most preferably 90-99% by weight.
When all of the remaining conductive filler of the above (1) is added together with the polyamide, it is more preferable to add it in the form of a polyamide masterbatch that has been melt-kneaded with the polyamide in advance. In this case, the preferred concentration of the conductive filler in the polyamide masterbatch is 5 to 15% by weight when the conductive filler is conductive carbon black, and 15 to 40% when the conductive filler is other than conductive carbon black. % By weight.
[0062]
In the case where a part of the remaining conductive filler of (2) is added together with the polyamide and the remaining conductive filler is added after the polyamide and the polyphenylene ether are melt-kneaded, the preferable amount ratio of the conductive filler is [polyamide] Together with the ratio of [conductive filler added after melt-kneading] / 90/10 to 10/90. Also in this case, the conductive filler added together with the polyamide is preferably in the form of a master batch with the polyamide.
[0063]
In the present invention, in addition to the above-described components, additional components may be added as needed as long as the effects of the present components are not impaired.
Examples of additional components are given below.
Other thermoplastic resins such as polyester and polyolefin, inorganic fillers (talc, kaolin, zonotrite, wollastonite, titanium oxide, potassium titanate, glass fiber, etc.), to increase the affinity between the inorganic filler and the resin Known adhesion improvers, flame retardants (halogenated resins, silicone-based flame retardants, magnesium hydroxide, aluminum hydroxide, organic phosphoric acid ester compounds, ammonium polyphosphate, red phosphorus, etc.) Polymers, plasticizers (oil, low molecular weight polyolefin, polyethylene glycol, fatty acid esters, etc.), flame retardant aids such as antimony trioxide, colorants such as carbon black, antistatic agents, various peroxides, zinc oxide, Zinc sulfide, antioxidants, ultraviolet absorbers, light stabilizers and the like.
[0064]
The specific addition amount of these components is in a range not exceeding 100 parts by weight in total with respect to 100 parts by weight in total of polyamide, polyphenylene ether and impact modifier.
Specific processing machines for obtaining the composition of the present invention include, for example, a single-screw extruder, a twin-screw extruder, a roll, a kneader, a Brabender plastograph, a Banbury mixer and the like. A twin-screw extruder having an upstream feed port and one or more downstream feed ports is most preferable.
[0065]
The melt-kneading temperature at this time is not particularly limited, but the temperature at which a suitable composition can be obtained is usually arbitrarily selected from 240 to 360 ° C.
The preferred production method of the present invention uses a twin-screw extruder having an upstream supply port and one or more downstream supply ports. (1) The impact modifier, polyphenylene ether and conductive filler are supplied from the upstream supply port. A method of supplying an amount of more than 0 and less than 50% by weight and melt-kneading, and then supplying and melting and kneading all of the polyamide and the remaining conductive filler from a downstream supply port; (2) Improving impact from an upstream supply port After supplying the material, polyphenylene ether and the conductive filler in an amount of more than 0 and less than 50% by weight and melt-kneading, the polyamide and a part of the remaining conductive filler are supplied from the downstream first supply port and melt-kneaded. A method in which all of the remaining conductive filler is supplied from the downstream second supply port and further melt-kneaded may be mentioned, but the method is not limited thereto.
[0066]
The composition of the present invention thus obtained can be molded as a molded body of various parts by various conventionally known methods, for example, injection molding.
These various components include, for example, IC tray materials, electric and electronic components such as chassis and cabinets for various disc players, etc., OA components and mechanical components such as various computers and their peripheral devices, as well as motorcycle cowls and automobile fenders.・ Door panel ・ Front panel ・ Rear panel ・ Locker panel ・ Rear bumper panel ・ Back door garnish ・ Emblem garnish ・ Fuel inlet panel ・ Over fender ・ Outer door handle ・ Door mirror housing ・ Bonnet air intake ・ Bumper ・ Bumper guard ・ Roof rail ・Exterior parts such as roof rail legs, pillars, pillar covers, wheel covers, spoilers, etc., exterior parts such as various malls and emblems, and instrument panels - it can be suitably used for interior parts typified by console box trim or the like.
Among them, it can be particularly suitably used for exterior parts of automobiles capable of electrostatic coating. Among them, it can be most preferably used for fender applications and side door panels that require impact resistance.
[0067]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
(Raw materials used)
(1) Polyphenylene ether (hereinafter abbreviated as PPE)
Poly (2,6-dimethyl-1,4-phenylene ether)
Reduced viscosity: 0.42 dl / g
(2) Polyamide 66 (hereinafter abbreviated as PA)
Number average molecular weight: 14,000
Terminal amino group concentration: 30 meq / kg
Terminal carboxyl group concentration: 110 meq / kg
Contains 30 ppm of CuI and 350 ppm of KI as trace stabilizer components
[0068]
(3) Impact modifier
(3-1) High molecular weight block copolymer (hereinafter abbreviated as SEBS-H1)
Bonding form: polystyrene-hydrogenated polybutadiene-polystyrene
Number average molecular weight: 246,000
Number average molecular weight per polystyrene block: 40,600
Bound styrene content: 33%
1,2-vinyl content: 33%
Hydrogenation rate of polybutadiene part: 98% or more
[0069]
(3-2) Low molecular weight block copolymer-1 (hereinafter abbreviated as SEBS-L1)
Bonding form: polystyrene-hydrogenated polybutadiene-polystyrene
Number average molecular weight: 98,500
Number average molecular weight per polystyrene block: 14,300
Bound styrene content: 29%
1,2-vinyl content: 32%
Hydrogenation rate of polybutadiene part: 98% or more
[0070]
(3-3) Low molecular weight block copolymer-2 (hereinafter abbreviated as SEBS-L2)
Bonding form: polystyrene-hydrogenated polybutadiene-polystyrene
Number average molecular weight: 115,000
Number average molecular weight per polystyrene block: 34,500
Bound styrene content: 60%
1,2-vinyl content: 35%
Hydrogenation rate of polybutadiene part: 98% or more
[0071]
(4) Conductive filler
(4-1) Conductive carbon black (hereinafter abbreviated as KB)
Product name: Ketjen Black EC-600JD (Ketjen Black International)
DBP oil absorption: 495 ml / 100 g
BET surface area: 1270cm ² / G
(4-2) Carbon nanofiber (hereinafter abbreviated as CNF)
Product name: VGCF (Showa Denko)
Average fiber diameter: 80 nm
Average fiber length: 15 μm
[0072]
(5) Conductive filler masterbatch
(5-1) PA / KB master batch (hereinafter abbreviated as KB-MB)
Using a ZSK-25 twin-screw extruder [manufactured by Werner & Friedler Co., Ltd.] having one supply port on each of the upstream side and the downstream side, the temperature from the upstream supply port to the downstream supply port is 280 ° C., and the downstream side. The temperature from the supply port to the die is set at 290 ° C., 90 parts by weight of PA is supplied from the upstream supply port, and 10 parts by weight of KB is supplied from the downstream supply port, melt-kneaded, and a PA / KB master having a KB concentration of 10% by weight. I got a batch. The screw rotation speed at this time was 400 rpm. At this time, volatile components were removed by vacuum from the upstream supply port and a vacuum suction vent port installed in front of the die.
[0073]
(5-2) PA / CNF master batch (hereinafter abbreviated as CNF-MB)
The same extruder as used for KB-MB production was set at the same temperature, and 80 parts by weight of PA was supplied from the upstream supply port and 20 parts by weight of CNF was supplied from the downstream supply port. / CNF masterbatch was obtained. The screw rotation speed at this time was 400 rpm. At this time, volatile components were removed by vacuum from the upstream supply port and a vacuum suction vent port installed in front of the die.
[0074]
(5-3) Polyamide 66 / CNT masterbatch (hereinafter abbreviated as CNT-MB)
Polyamide 66 / CNT masterbatch manufactured by Hyperion Catalyst (trade name: Polyamide66 with Fibril) ^TM Nanotubes RMB 4620-00) was used. The CNT concentration in this master batch is 20% by weight.
[0075]
(5-4) PPE / SEBS-L1 / KB masterbatch (hereinafter abbreviated as PPE-MB)
Using the same extruder as during the production of KB-MB, everything from the upstream supply port to the die was set at 320 ° C., 30 parts by weight of PPE and 60 parts by weight of SEBS-L1 were supplied from the upstream supply port, 10 parts by weight of KB was supplied from the downstream supply port to obtain PPE-MB having a KB concentration of 10% by weight. The screw rotation speed at this time was 300 rpm. At this time, volatile components were removed by vacuum from the upstream supply port and a vacuum suction vent port installed in front of the die.
(6) Compatibilizer: maleic anhydride (hereinafter abbreviated as MAH)
[0076]
(Measuring method)
<Volume resistivity (hereinafter abbreviated as VR)>
A 3.2 mm-thick tensile test piece (ASTM D638 type I dumbbell bar) was cut at both ends with a precision cut-and-saw, and a cut surface having a length of 50 mm and a uniform cross-sectional area (12.4 × 3.2 mm) was cut at both ends. A strip test piece was obtained. A silver paste was applied to the cut surfaces at both ends of the test piece and dried sufficiently. Then, the resistance value between both ends was measured at a voltage of 500 V using a tester, and calculated as a volume specific resistance using the following equation. .
VR = (R · w · t) / l
Here, VR is the volume resistivity (Ω · cm), R is the resistance value (Ω) measured by a tester, w is the width (cm) of the portion where the silver paste is applied, and t is the portion where the silver paste is applied. Is the height (cm), and l is the distance (cm) between the surfaces on which the silver paste is applied. Note that this measurement was performed on ten different test pieces, and their average was used as a volume specific resistance value.
[0077]
<High-speed surface impact strength at low temperature (hereinafter abbreviated as low-temperature surface impact)>
The measurement was carried out using a graphic impact tester [manufactured by Toyo Seiki Seisakusho] using a flat molded piece having a length of 90 mm, a width of 50 mm and a thickness of 2.5 mm.
The test method was as follows: a flat test piece was allowed to stand in a low-temperature constant temperature bath set at −30 ° C. for 120 minutes, sufficiently cooled, quickly taken out, and placed in a sample holder having a diameter of 40 mm. A 13 mm spherical striker (weight 6.5 kg) is dropped freely from a height at which the collision speed becomes 5 m / sec to break the test piece, and the total energy required for breaking (unit: J) at that time Was measured. The obtained energy was divided by the thickness of the test piece and expressed as total absorbed energy per unit thickness (unit: J / cm).
[0078]
<High temperature rigidity (hereinafter G ' ₍₁₂₀₎ Abbreviation)>
Both ends of a 3.2 mm thick tensile test piece (ASTM D638 type I dumbbell bar) were cut with a precision cut saw to obtain a strip-shaped test piece having a length of 30 mm and a width of 12.4 mm. The shear storage modulus (G ') of the obtained test piece was measured by Rheometrics Dynamic Analyzer II (RDAII) [manufactured by Rheometrics Scientific Co.]. The measurement mode at this time was a temperature sweep mode, in which the temperature range was 40 ° C. to 250 ° C., the rate of temperature rise was 3 ° C./min, the measurement frequency was 10 Hz, and the strain was 0.2%.
The shear storage modulus at 120 ° C. based on the obtained results was measured and compared.
[0079]
<Heat resistance (hereinafter abbreviated as HDT)>
The deflection temperature under load was measured at a load of 1.82 MPa in accordance with ASTM D648. This measurement was carried out on ten different test pieces, and the average was taken as the HDT value.
[0080]
<Fluidity (hereinafter abbreviated as SSP)>
Using an injection molding machine IS-80EPN [manufactured by Toshiba Machine Co., Ltd.], the minimum injection pressure at which a tensile test piece (ASTM D638 type I dumbbell bar) can be filled when the injection speed, mold and cylinder temperature settings are kept constant. (The minimum injection pressure required to fill a tensile test specimen). Since this value is a comparison at the injection pressure, the smaller the value, the better the fluidity.
At this time, the mold temperature was set at 80 ° C., and the cylinder temperature was set at 290 ° C.-290 ° C.-280 ° C.-270 ° C. from the nozzle toward the hopper. The molding cycle was 10 seconds for injection, 15 seconds for cooling, and 2 seconds for the interval. The measurement was performed after molding at least 20 shots and keeping the mold temperature constant.
[0081]
<Surface appearance when the molding machine stays (hereinafter abbreviated as appearance after staying)>
The cylinder temperature of the injection molding machine IS-80EPN was set from 310 ° C to 310 ° C to 300 ° C to 290 ° C from the nozzle to the hopper side, and about 20 flat molded pieces 90 mm long, 50 mm wide and 2.5 mm thick were formed. After that, the cycle of the molding machine was stopped for 2 minutes, and the resin composition was retained in the cylinder. Thereafter, molding was started, and the surface appearance of the plate-shaped molded piece of the first shot was visually evaluated.
A three-stage evaluation was performed in which a silver mark (silver) appeared on the entire surface of the molded piece was evaluated as x, a slight appearance of the molded piece was evaluated as △, and a none appeared at all as ○.
The mold temperature at this time was 80 ° C., the injection pressure was the pressure of SSP, and the molding cycle was injection 10 seconds, cooling 15 seconds, and interval 2 seconds.
[0082]
Examples 1 to 5 and Comparative Examples 1 and 2
One supply port on the upstream side and two places on the downstream side (of the downstream supply ports, the upstream supply port is the downstream first supply port, and the downstream supply port is the downstream second supply port) The cylinder temperature of the co-rotating twin-screw extruder ZSK-40 (manufactured by Werner & Friedler) having a temperature of 320 ° C. from the upstream supply port to the first downstream supply port, and 280 from the first downstream supply port to the die. ° C, and were supplied from the upstream supply port and the first downstream supply port at the ratios shown in Table 1, respectively, melt-kneaded, and pelletized.
[0083]
At this time, the screw rotation speed was 300 rpm, and vacuum suction was carried out at two places in front of the first downstream supply port and the die in order to remove volatile components.
The obtained pellets were injection molded into various test pieces using an IS-80 EPN molding machine. At this time, SSP was measured simultaneously. Using the obtained test pieces, volume resistance, HDT, low-temperature surface impact, and high-temperature rigidity were measured. Each physical property value is also shown in Table 1.
Even with the same amount of conductive filler, it was found that by adding a small amount of conductive filler from the upstream supply port, volume resistivity and low-temperature surface impact were simultaneously improved. It can be seen that there is a clear critical point between the addition of the conductive filler from the side supply port and the addition of a small amount.
[0084]
Embodiments 6 to 8
The same operation as in Example 1 was carried out except that the material was supplied from each supply port at the ratio shown in Table 2. Each physical property value is also shown in Table 2.
A comparison between Examples 2 and 7 shows that the combined use of a high molecular weight block copolymer and a low molecular weight block copolymer as the impact modifier improves the low-temperature surface impact.
Further, in Example 6 using a block copolymer having a sufficient polystyrene block molecular weight and a large amount of bound styrene as the low molecular weight block copolymer, the high-temperature rigidity and HDT were significantly higher than those in Example 2. You can see that it has improved.
Furthermore, in Example 8, in which the low molecular weight block copolymer was made of two types of blends having different amounts of bound styrene, it can be seen that the fluidity was significantly improved as compared with Examples 2, 6, and 7.
[0085]
Example 9 and Comparative Example 3
The same operation as in Example 1 was carried out except that the material was supplied from each supply port at the ratio shown in Table 3. Each physical property value is also shown in Table 3.
Also in this case, it can be seen that adding a small amount of the conductive filler from the upstream supply port improves the volume resistivity and the low-temperature surface impact as compared with Comparative Example 3 in which nothing is added.
[0086]
Embodiment 10
All the operations were carried out in the same manner as in Example 1 except that the gas was supplied from each supply port at the ratio shown in Table 4. Each physical property value is also shown in Table 4.
It can be seen that the composition of the present invention has an excellent balance between volume resistivity and low-temperature surface impact even when the remaining conductive filler other than the conductive filler added from the upstream supply port is further divided and supplied.
[0087]
Embodiments 11 and 12
All the operations were performed in the same manner as in Example 1 except that the supply was performed at the ratio shown in Table 5 from the upstream supply port and the downstream first supply port. At the time of this molding, the surface appearance when the molding machine stayed was measured at the same time. Each physical property value is also shown in Table 5.
By changing the form of addition of the impact modifier and the conductive filler that is previously melt-kneaded with polyphenylene ether to the form of a masterbatch, it is possible to dramatically improve the surface appearance when the molding machine stays while maintaining other physical properties. I understand.
[0088]
[Table 1]

[0089]
[Table 2]

[0090]
[Table 3]

[0091]
[Table 4]

[0092]
[Table 5]

[0093]
【The invention's effect】
The composition of the present invention comprises a resin composition, a production method thereof, and a resin composition capable of simultaneously improving conductivity (specific resistance to volume) and low-temperature surface impact strength by optimizing the addition position and the addition ratio of the conductive filler. It is a molded article.

Claims (20)

A resin composition comprising (A) a polyamide, (B) a polyphenylene ether, (C) an impact modifier, and (D) a conductive filler,
Step a: a step of melt-kneading the components (B), (C) and (D);
Step b: A step of melt-kneading all or a part of the component (A) and the component (D) and the step c. The composition obtained in the step a, the composition obtained in the step b, and the remaining component (A) if necessary. Wherein the amount of the component (D) in step a is more than 0 and less than 50% by weight based on 100% by weight of all the components (D). A part or all of the component (D) in the step a is added in the form of a masterbatch previously melt-kneaded with at least one selected from the components (B), (C) and (A). 3. The resin composition according to item 1. 3. The conductive resin composition according to claim 1, wherein the step (d) of melt-kneading the component and the composition obtained in the step c is performed after the step c. The conductive resin composition according to any one of claims 1 to 3, wherein the amount of the component (D) in step a is 0.1 to 20% by weight when all the components (D) are 100% by weight. . 5. The conductive resin composition according to claim 1, wherein the amount of the component (D) in step a is 1 to 10% by weight when all the components (D) are 100% by weight. 6. The component (C) is composed of a polymer block [A] mainly composed of an aromatic vinyl compound and a polymer block [B] mainly composed of a conjugated diene compound. The conductive resin composition according to claim 1, which is at least one aromatic vinyl compound-conjugated diene compound block copolymer selected from the group consisting of ABA type and ABAB type and / or a hydrogenated product thereof. The conductive resin composition according to claim 1 or 6, wherein the component (C) is a hydrogenated product of an aromatic vinyl compound-conjugated diene compound block copolymer. The component (C) is a mixture of (C-1) an impact modifier having a number average molecular weight of 120,000 or more and (C-2) an impact modifier having a number average molecular weight of less than 120,000. The conductive resin composition according to any one of the above. The conductive resin composition according to any one of claims 1, 6 to 8, wherein the number average molecular weight of the polymer block mainly composed of the aromatic vinyl compound as the component (C-2) is 20,000 or more. The conductive resin composition according to any one of claims 1, 6 to 10, wherein the component (C-2) is a block copolymer containing an aromatic vinyl compound in an amount of 55% by weight or more and less than 90% by weight. . The conductive resin composition according to any one of claims 1 to 5, wherein the component (D) is at least one selected from conductive carbon black, carbon nanotubes, carbon nanofibers, carbon fibers, and graphite. The conductive resin composition according to claim 11, wherein the component (D) is a conductive carbon black having a DBP oil absorption of 250 ml / 100 g or more. The conductive resin composition according to claim 11, wherein the component (D) is a carbon nanotube having an average fiber diameter of 1 nm or more and less than 75 nm. The conductive resin composition according to claim 11, wherein the component (D) is a carbon nanofiber having an average fiber diameter of 75 nm or more and less than 1000 nm. The conductive resin according to any one of claims 1 to 5, wherein the amount of the conductive filler is 0.1 to 3 parts by weight based on 100 parts by weight of the total of the components (A) to (C). Composition. When the amount ratio of the components (A) to (C) is 100 parts by weight of the total of these three components, 30 to 70 parts by weight of the component (A), 20 to 50 parts by weight of the component (B), and (C) The conductive resin composition according to any one of claims 1 to 13, wherein the component is 5 to 30 parts by weight. 2. The conductive resin composition according to claim 1, wherein in step b, the amount of the component (D) is 5 to 40% by weight when the total amount of the components (A) and (D) is 100% by weight. An injection-molded article comprising the conductive resin composition according to claim 1. An automotive exterior material comprising the conductive resin composition according to any one of claims 1 to 16. A resin composition comprising (A) a polyamide, (B) a polyphenylene ether, (C) an impact modifier, and (D) a conductive filler,
Step a: a step of melt-kneading the components (B), (C) and (D);
Step b: A step of melt-kneading all or a part of the component (A) and the component (D) and the step c. The composition obtained in the step a, the composition obtained in the step b, and the remaining component (A) if necessary. Of a conductive resin composition obtained through a step of melt-kneading and the amount of the component (D) in the step a is more than 0 and less than 50% by weight when all the components (D) are 100% by weight. Production method.