JP2004143239A - Conductive resin composition and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition which simultaneously achieves conductivity at an electrostatically coatable level, a low linear expansion coefficient, and a high appearance, and widely depresses the by-production of cut chips, when extrusion-molded, to provide a method for producing the composition, and to provide a molded product thereof. <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), a process for melting and kneading the obtained composition and all or a part of the component (A), and a process for melting and kneading the obtained composition and the component (D), wherein the amount of the component (D) in the process is ≥50wt.% and <100wt.%, when the total amount of the component (D) is 100wt.%. <P>COPYRIGHT: (C)2004,JPO

Description

【００２３】
〔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。〕
【００２４】
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。
【００２５】
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号明細書、同第３３０６８７５号明細書、同第３２５７３５７号明細書及び同第３２５７３５８号明細書、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。
【００２６】
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。
【００２７】
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。
【００２８】
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。
【００２９】
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。
【００３０】
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。
【００３１】
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。
【００３２】
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。
【００３３】
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。
【００３４】
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。
【００３５】
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。
【００３６】
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。
【００３７】
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。
【００３８】
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。
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。
【００３９】
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。
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。
【００４０】
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。
【００４１】
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、使用するブロック共重合体として、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混合物を使用することが望ましい。
具体的には、数平均分子量１２０，０００未満の低分子量ブロック共重合体と、数平均分子量１２０，０００以上の高分子量ブロック共重合体の混合物である。
【００４２】
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。
【００４３】
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、耐熱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。
【００４４】
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。］
【００４５】
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出きるため、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。
【００４６】
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。
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。
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。
【００４７】
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。
【００４８】
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。
【００４９】
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。
【００５０】
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。
【００５１】
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、カーボンで被覆された無機フィラー、アルミニウムでドープされた金属酸化物、アンチモンでドープされた金属酸化物で被覆された無機フィラー等が挙げられる。
【００５２】
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。
【００５３】
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。
【００５４】
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。
【００５５】
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。
【００５６】
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。
【００５７】
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。
【００５８】
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、５０重量％以上１００重量％未満の量である。より好ましくは、６０重量％以上９９％未満、最も好ましくは７０重量％以上９０重量％未満の量である。
また、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飛躍的に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導電性フィラーの比率は、該マスターバッチの合計量を１００重量％としたときに、５〜４０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は、ポリフェニレンエーテルとポリアミドが溶融混練された後に添加されることが必須である。
この場合、（１）ポリフェニレンエーテルとすべてのポリアミドを溶融混練した後に、残りの導電性フィラーすべてを添加する方法、（２）ポリフェニレンエーテルとポリアミドの一部が溶融混練された後に、残りの導電性フィラーを残りのポリアミドとともに添加し溶融混練する方法等が挙げられるが、本発明においての必須要件は、ポリフェニレンエーテルとポリアミドが溶融混練された後に導電性フィラーが添加されることである。
【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、０を越え５０重量％未満の量である。より好ましくは、１重量％以上４０重量％未満、最も好ましくは１０重量％以上３０重量％未満の量である。
ポリフェニレンエーテルとポリアミドを溶融混練した後に、添加される導電性フィラーはその一部または全部がポリアミドとあらかじめ溶融混練されたマスターバッチの形態で添加しても構わない。この場合の好ましい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】
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。
【００６３】
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。
【００６４】
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２箇所以上の下流側供給口（下流側供給口の内、より上流側を下流側第１供給口、より下流側を下流側第２供給口とする）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５０重量％以上１００重量％未満の量を供給し溶融混練した後、下流側第１供給口よりポリアミドのすべて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、（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５０重量％以上１００重量％未満の量を供給し溶融混練した後、下流側第１供給口よりポリアミドの一部を供給し溶融混練し、下流側第２供給口よりポリアミドの残りのすべてと導電性フィラーの残りのすべてを供給し、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。
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。
【００６５】
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好適に使用可能である。特に、低い線膨張係数が要求される大型部品（バックドアパネル、バンパー）等に好ましく使用することができる。
【００６６】
【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
【００６７】
（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
【００６８】
（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
【００６９】
（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
【００７０】
（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
【００７１】
（５）ポリアミドマスターバッチ
（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。
【００７２】
（５−２）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。
【００７３】
（６）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。
（７）相溶化剤：無水マレイン酸（以下。ＭＡＨと略記）
【００７４】
（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、１．５Ｖ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。
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。
【００７５】
線膨張係数
高さ３．２ｍｍの引張試験片の中央部を精密カットソーを用いて、厚み３．２ｍｍ、幅５ｍｍ、高さ１０ｍｍの四角柱形状に切削し、ＴＭＡ−７（パーキンエルマー社製）を用い、ＪＩＳ　Ｋ７１９７に準拠し、２３℃から７０℃までを昇温速度５℃／ｍｉｎで昇温しながら測定した。
押出加工時の切り粉の発生量
押出機の紡口にストランドバスとペレタイザーを設置し、ストランドバスを経た後のペレタイザー手前のストランドの直径が２ｍｍ〜３ｍｍになるようにペレタイザーの引き取り速度を調整した。この時、ストランドを水槽に浸漬する長さを１００ｃｍとした。なお、水温は１３℃〜１５℃の間であった。
この時のペレタイザーから出てきたペレットを約１００ｇ取り、これを精秤した。この値をＷ１とする。
次いで、この精秤したペレットを２０メッシュの金網上に広げてよく振とうし、ペレットと切り粉を分別した後、金網上に残ったペレットの重量を精秤した。この値をＷ２とする。
得られたＷ１とＷ２より下式を用いて切り粉の割合（重量％）を算出した。
切り粉の重量％＝（１−Ｗ２／Ｗ１）×１００
【００７６】
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。
【００７７】
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。
成形片表面外観（以下、成形片外観と略記）
射出成形機ＩＳ−８０ＥＰＮを用いて、長さ９０ｍｍ、幅５０ｍｍ、厚み２．５ｍｍの平板状成形片を成形し、目視で評価した。この時の成形条件はＳＳＰ測定時の成形条件と同じである。
【００７８】
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。
【００７９】
【実施例１〜３及び比較例１】
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下流側第１供給口までを３２０℃、下流側第１供給口よりダイまでを２８０℃に設定し、上流側供給口、下流側第１供給口及び下流側第２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。
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下流側第１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・線膨張係数を測定した。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添加する事で、体積固有抵抗と線膨張係数のバランスに優れ、更に切り粉の発生が大幅に抑制されている事が判る。
【００８０】
【実施例４〜６】
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。また、ここでは流動性とＨＤＴも測定した。各物性値は、表２に併記した。
実施例２と４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、流動性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５は、実施例４に比較して、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６では、実施例２，４及び５に比較して、ＨＤＴと流動性が大幅に向上していることが判る。
【００８１】
【実施例７】
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４と同様に実施した。各物性値は、表３に併記した。
導電性フィラーとして、導電性カーボンブラック以外に、カーボンナノチューブを用いても同様の物性を保持すること事が判る。
【００８２】
【実施例８〜１０】
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４と同様に実施した。また、ここでは滞留後外観の測定も実施した。各物性値は、表４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。
【００８３】
【表１】

【００８４】
【表２】

【００８５】
【表３】

【００８６】
【表４】

【００８７】
【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）と線膨張係数のバランスに優れる、樹脂組成物・その製法及びそれからなる成形体である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin composition that simultaneously achieves a level of conductivity that can be electrostatically coated, a low coefficient of linear expansion, and a high appearance, and further greatly suppresses the generation of chips during extrusion processing, and a method for producing the same .
The composition of the present invention can be used in a wide range of fields such as electric / electronic parts, OA parts, vehicle parts, machine parts, etc., and in particular, can be suitably used for automobile exterior parts capable of electrostatic coating. Among these, it can be preferably used for large parts (back door panels, bumpers) and the like that require a low coefficient of linear expansion.
[0002]
[Prior art]
Polyphenylene ether is used in a wide range of applications because it has excellent mechanical properties, electrical properties, and heat resistance, and also has excellent dimensional stability, but it is inferior in molding processability by itself. A technique of blending polyamide has been proposed in Patent Document 1, and is now a material used for a wide variety of applications.
Recently, the use of polyamide-polyphenylene ether alloys for applying electrical conductivity to automobile exterior materials (such as fenders and door panels) that can be electrostatically coated has been rapidly progressing.
[0003]
The characteristics required for automobile exterior materials include various characteristics such as conductivity at a level capable of electrostatic coating, low linear expansion coefficient, heat resistance, and fluidity.
As a technique for imparting conductivity to a polyamide-polyphenylene ether alloy, for example, Patent Document 2 discloses a technique for reducing the surface resistance value by containing carbon black mainly in a polyamide phase. Patent Document 3 discloses a technique in which a composition comprising polyamide, polyphenylene ether, and carbon black is excellent in volume resistivity, fluidity, heat resistance, and impact strength.
[0004]
Patent Document 4 and Patent Document 5 disclose a composition containing conductive carbon fibrils and excellent in impact strength and volume resistivity, and Patent Document 6 discloses compatibilization of polyamide and polyphenylene ether. After that, a technique is disclosed in which a composition having excellent impact strength and volume resistivity can be obtained by blending conductive carbon black.
Further, Patent Document 7 discloses a composition having excellent falling-drop impact strength and conductivity by using a plurality of polyamides and conductive carbon black, and Patent Document 8 discloses the amount of a compatibilizer. A technique for obtaining a composition having excellent conductivity by limiting the amount to a specific amount is disclosed.
[0005]
Patent Document 9 discloses a technique in which a composition composed of polyphenylene ether, polyamide, talc, and carbon is excellent in conductivity, fluidity, and unnotched Izod impact strength.
In addition, many applications such as Patent Document 10, Patent Document 11, Patent Document 12, Patent Document 13, Patent Document 14, and Patent Document 15 have been filed.
In recent years, studies have been started on automotive exterior materials with a view to application to large vehicles. In a large vehicle, since each part becomes large, it is required that a dimensional change due to a change in outside air temperature is small.
[0006]
For example, in a fender material having a length of 100 cm, the linear expansion coefficient is 7 × 10 ^-5 (℃ ^-1 ) And 9 × 10 ^-5 (℃ ^-1 ), When compared under a certain temperature condition, a dimensional difference of about 2 mm at maximum occurs between the two materials. [When temperature difference is 100 ° C. (for example, −30 ° C. to 70 ° C.)]
The difference of 2 mm affects the clearance with the door or the like, and in the worst case, the inconvenience of contact when the door is opened or closed occurs.
From these factors, a characteristic of a low coefficient of linear expansion is particularly required when considering application to a large vehicle.
[0007]
However, in the above-described technique, although conductivity is imparted, a low linear expansion coefficient has not yet been achieved, and it cannot be sufficiently applied to these uses.
On the other hand, as a conventional technique related to improvement of the linear expansion coefficient in polyamide-polyphenylene ether alloy, for example, Patent Document 16, Patent Document 17, and Patent Document 18 describe that a composition containing an inorganic filler is useful. . However, in these techniques, the irregularities of the inorganic filler appear on the molded piece and the appearance is poor, and it becomes unpractical.
[0008]
In addition, the conventional conductivity imparting technique and the low linear expansion technique as in the technique described above, the composition becomes brittle, so the pelletizing process at the time of processing (cutting the strand from the extruder into pellets) In the process of generating a large amount of chips called “chip”.
These chips adher to pellet dryers, newer systems to molding machines, molding machine hoppers, etc. in molding plants, necessitating cleaning when switching resin, a factor that greatly reduces productivity There is a need for improvement.
[0009]
Usually, it is difficult to completely remove these chips, and the only solution is to suppress the occurrence.
The problems such as the above-described conductivity, low linear expansion coefficient, high appearance without filler floating, and simultaneously suppressing the generation of chips cannot be sufficiently solved by a combination of conventional techniques alone, For this reason, the development of new technology is now awaited.
[0010]
[Patent Document 1]
Japanese Examined Patent Publication No. 45-997 (first page, claims)
[Patent Document 2]
JP-A-2-201811 (first page, claim 1)
[Patent Document 3]
Japanese Patent Laid-Open No. 4-3000296 (page 2 claim 1)
[Patent Document 4]
JP-A-8-508534 (second page, claim 1)
[Patent Document 5]
US Pat. No. 5,643,502 (paragraph 18 claim 1)
[Patent Document 6]
Japanese Patent Application Laid-Open No. 8-48869 (second page, claim 7)
[Patent Document 7]
Japanese Patent Laid-Open No. 10-310695 (page 2 claim 1)
[Patent Document 8]
US Pat. No. 6,212,283 (8th paragraph, claim 1)
[Patent Document 9]
International Publication No. 2001/36536 pamphlet (page 23, claim 1)
[Patent Document 10]
JP 2001-302905 A (page 2 claim 1)
[Patent Document 11]
JP 2002-129023 A (2nd page, claim 1)
[Patent Document 12]
JP 2002-146205 A (Page 2 Claim 1)
[Patent Document 13]
JP 2002-146206 A (Page 2 Claim 1)
[Patent Document 14]
JP 2002-194207 A (page 2 claim 1)
[Patent Document 15]
JP 2002-194093 A (page 2 claim 1)
[Patent Document 16]
JP-A-2-163158 (Page 1 Claims)
[Patent Document 17]
Japanese Patent Laid-Open No. 4-372656 (Page 2 Claim 1)
[Patent Document 18]
JP-A-6-306275 (Page 2 Claim 1)
[0011]
[Problems to be solved by the invention]
The object of the present invention is to solve these problems (conductivity, low linear expansion coefficient, high appearance with no filler floating, and at the same time suppressing the generation of chips) of polyamide / polyphenylene ether alloy. It is.
[0012]
[Means for Solving the Problems]
As a result of investigations to solve the above-mentioned problems, the present inventors have surprisingly found that 50% by weight or more and less than 100% by weight of all conductive fillers to be used are preliminarily mixed with a mixture containing an impact modifier and polyphenylene ether. It has been found that, by melt-kneading, a level of electroconductivity, low linear expansion coefficient and high appearance without floating of filler can be achieved, and at the same time, generation of chips can be suppressed, and the present invention has been achieved.
That is, the present invention
A resin composition comprising (A) polyamide, (B) polyphenylene ether, (C) impact modifier, and (D) conductive filler,
Step a: a step of melt-kneading the component (B), the component (C) and the component (D),
Step b Melting and kneading the composition obtained in Step a and all or part of the component (A) and
Step c Step of melt-kneading the composition obtained in step b, the remaining component (D), and, if necessary, the remaining component (A)
And the amount of the component (D) in step a is 50% by weight or more and less than 100% by weight when all the components (D) are 100% by weight. About.
[0013]
Further, the present invention provides a method for producing a conductive resin composition, characterized in that 50% by weight or more and less than 100% by weight of all the conductive fillers used are previously melt kneaded with a mixture containing an impact modifier and polyphenylene ether. The present invention also relates to a molded article for automobile exterior made of the composition.
Next, each component that can be used in the present invention will be described in detail.
As the kind of the polyamide of component (A) that can be used in the present invention, any polyamide having an amide bond {—NH—C (═O) —} in the polymer main chain may be used. it can.
In general, polyamide is a ring-opening polymerization of lactams. Although obtained by polycondensation of diamine and dicarboxylic acid, polycondensation of aminocarboxylic acid, etc., it is not limited to these.
[0014]
The diamines are roughly classified into aliphatic, alicyclic and aromatic diamines, and specific examples include tetramethylene diamine, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, tridecamethylene diamine, 2, 2 , 4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 5-methylnanomethylenediamine, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, m-phenylenediamine, p -Phenylenediamine, m-xylylenediamine, p-xylylenediamine.
[0015]
Dicarboxylic acids are roughly classified into aliphatic, alicyclic and aromatic dicarboxylic acids. Specific examples include adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, 1,1,3-tridecane. Examples include diacid, 1,3-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, dimer acid and the like.
Specific examples of lactams include ε-caprolactam, enantolactam, and ω-laurolactam.
[0016]
Specific examples of aminocarboxylic acids include ε-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and 13-aminotriic acid. Examples include decanoic acid.
In the present invention, any of the copolymer polyamides obtained by polycondensation of these lactams, diamines, dicarboxylic acids, and ω-aminocarboxylic acids alone or in a mixture of two or more can be used.
Further, those obtained by polymerizing these lactams, diamines, dicarboxylic acids, and ω-aminocarboxylic acids up to a low molecular weight oligomer stage in a polymerization reactor and increasing the molecular weight in an extruder or the like can be suitably used.
[0017]
In particular, polyamide resins that can be usefully used 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 (metaxylylene adipamide). (Hereinafter abbreviated as MXD6 nylon), poly (hexamethylene terephthalamide) (hereinafter abbreviated as 6T nylon), poly (hexamethylene isophthalamide) (hereinafter abbreviated as 6I nylon), poly (nonamethylene terephthalamide) (hereinafter referred to as 9T nylon) And aliphatic-aromatic polyamides such as poly (tetramethyleneisophthalamide) (hereinafter abbreviated as 4I nylon) and copolymers and mixtures thereof. Polyamides obtained by copolymerizing a plurality of polyamides with an extruder or the like can also be used. Preferred polyamides are polyamide 6, polyamide 6,6, polyamide 6 / 6,6 and mixtures thereof, most preferably polyamide 6,6.
[0018]
The number average molecular weight of the polyamide resin used in the present invention is preferably 5,000 to 100,000, more preferably 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 molecular weight of 30,000 or more, a mixture of a low molecular weight polyamide having a number average molecular weight of 10,000 or less, and a general polyamide having about 15,000. It is.
[0019]
The end groups of the polyamide are involved in the reaction with the polyphenylene ether. Polyamide resins generally have amino groups and carboxyl groups as end groups, but generally the higher the carboxyl group concentration, the lower the impact resistance, the better the fluidity, and conversely the amino group concentration. As the value increases, the impact resistance improves and the fluidity decreases.
In the present application, these preferred ratios are amino group / carboxyl group concentration ratios of 9/1 to 1/9, more preferably 8/2 to 1/9, still more preferably 6/4 to 1/9. .
[0020]
The concentration of the terminal amino group is preferably at least 10 meq / kg. More preferably, it is 30 meq / kg or more.
As a method for adjusting the end groups of these polyamide resins, a known method that will be apparent to those skilled in the art can be used. For example, there may be mentioned a method of adding diamines, dicarboxylic acids, monocarboxylic acids or the like so that a predetermined terminal concentration is obtained during polymerization of the polyamide resin.
Moreover, a metal stabilizer as described in JP-A-1-163262, which has been publicly known for the purpose of improving the heat resistance stability of the polyamide resin, can be used without any problem.
[0021]
Among these metal stabilizers, those which can be particularly preferably used include CuI and CuCl. ₂ , Copper acetate, cerium stearate and the like. Further, halogenated salts of alkyl metals typified by potassium iodide, potassium bromide and the like can also be suitably used. Of course, these may be added together.
A preferable blending amount of the metal stabilizer and / or the alkyl metal halide salt is 0.001 to 1 part by weight with respect to 100 parts by weight of the polyamide resin as a total amount.
Furthermore, 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 with respect to 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 copolymer composed of the structural unit of the formula (1).
[0022]
[Chemical 1]

[0023]
[Wherein O is an oxygen atom, R is independently hydrogen, halogen, primary or secondary lower alkyl, phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy, or halohydrocarbonoxy (provided that At least two carbon atoms separating the halogen atom and the oxygen atom). ]
[0024]
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), poly (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, a copolymer with 2,3,6-trimethylphenol or a copolymer with 2-methyl-6-butylphenol as described in JP-B-52-17880) Polyphenylene ether copolymers may also be mentioned.
[0025]
Among 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 these 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 are disclosed. And the production methods described in JP-A-3257358, JP-A-50-51197 and JP-A-63-152628.
[0026]
Reduced viscosity of polyphenylene ether that can be used in the present invention (η _{sp / c} : 0.5 g / dl, chloroform solution, 30 ° C. measurement) 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, even 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. A mixture of polyphenylene ethers, etc., of course, is, of course, not limited to these.
[0027]
In the polyphenylene ether that can be used in the present invention, the organic solvent resulting 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. These organic solvents resulting from the polymerization solvent are difficult to remove completely in the drying step after polymerization, and usually remain in the range of several hundred ppm to several percent. Examples of the organic solvent resulting from the polymerization solvent include one or more of toluene, xylene isomers, ethylbenzene, C1-5 alcohols, chloroform, dichloromethane, chlorobenzene, dichlorobenzene and the like.
[0028]
In addition, the polyphenylene ether that can be used in the present invention may be a polyphenylene ether modified in whole or in part.
The modified polyphenylene ether here 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. The polyphenylene ether modified with at least one modifying compound having a group.
[0029]
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 higher in the presence or absence of a radical initiator and lower than the glass transition temperature of the polyphenylene ether. (2) a method in which a modified compound is melt-kneaded and reacted at a temperature in the range of the glass transition temperature of polyphenylene ether to 360 ° C. in the presence or absence of a radical initiator, and (3) a radical initiator. In the presence or absence, a method of reacting a polyphenylene ether and a modifying compound in a solution at a temperature lower than the glass transition temperature of the polyphenylene ether may be mentioned. Any of these methods may be used, (1) and The method (2) is preferred.
[0030]
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 Will be described in detail.
Examples of modified compounds 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 these And acid anhydrides. Fumaric acid, maleic acid, and maleic anhydride are particularly preferable, and fumaric acid and maleic anhydride are particularly preferable.
[0031]
In addition, those in which one or two of the carboxyl groups of the unsaturated dicarboxylic acid are esters can be used.
Examples of the modified compound having 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.
Among these, glycidyl acrylate and glycidyl methacrylate are particularly preferable.
[0032]
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, general formula C _n H _2n-5 OH, C _n H _2n-7 Examples thereof include unsaturated alcohols such as OH (n is a positive integer).
The above-described modifying compounds may be used alone or in combination of two or more.
[0033]
The amount of the modifying compound added when producing the modified polyphenylene ether is preferably from 0.1 to 10 parts by weight, more preferably from 0.3 to 5 parts by weight, based on 100 parts by weight of the polyphenylene ether.
A preferable amount of the radical initiator in producing the polyphenylene ether modified with the radical initiator is 0.001 to 1 part by weight with respect to 100 parts by weight of the polyphenylene ether.
[0034]
The addition rate of the modifying 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.
In order to reduce the amount of the modified compound and / or polymer of the modified compound remaining in the modified polyphenylene ether, an amide bond and / or an amide bond and / or Alternatively, a compound having an amino group may be added.
[0035]
The compound having an amide bond here is a compound having an amide bond {—NH—C (═O) —} structure in the molecular structure, and the compound having an amino group is terminated with {—NH. ₂ } 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, p-xylylenediamine. Aromatic amines such as the above, reactants of the above amines with carboxylic acid, dicarboxylic acid and the like, lactams such as ε-caprolactam, and polyamide resins, but are not limited thereto.
[0036]
A preferable addition amount when adding 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 with respect to 100 parts by weight of the polyphenylene ether. Preferably they are 0.01 weight part or more and less than 1 weight part, More preferably, they are 0.01 weight part or more and less than 0.1 weight part.
Moreover, in this invention, you may mix | blend a styrene-type thermoplastic resin if it is the quantity of less than 50 weight part with respect to a total of 100 weight part of polyamide and polyphenylene ether.
[0037]
Examples of the styrenic thermoplastic resin in the present invention include homopolystyrene, rubber-modified polystyrene (HIPS), styrene-acrylonitrile copolymer (AS resin), styrene-rubbery polymer-acrylonitrile copolymer (ABS resin), and the like. Can be mentioned.
Further, known additives that can be added to polyphenylene ether may be added in an amount of less than 10 parts by weight based on 100 parts by weight of polyphenylene ether.
[0038]
Next, the impact improving material of 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 composed of an aromatic vinyl compound and a polymer block mainly composed of a conjugated diene compound. It is 1 or more types chosen from the group which consists of a coalescence, its hydrogenated substance, and an ethylene-alpha-olefin copolymer.
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 among them.
Specific examples of the conjugated diene compound include butadiene, isoprene, piperylene, 1,3-pentadiene, etc., and one or more compounds selected from these are used, and among them, butadiene, isoprene and combinations thereof. Is preferred.
[0039]
The microstructure of the soft segment portion of the conjugated diene compound of the block copolymer is preferably 1,2-vinyl content or the total amount of 1,2-vinyl content and 3,4-vinyl content of 5-80%, 10 to 50% is preferable, and 10 to 40% is most preferable.
In the block copolymer of the present invention, the polymer block [A] mainly composed of an aromatic vinyl compound and the polymer block [B] mainly composed of a conjugated diene compound are AB type, ABA type, A block copolymer having a bond type selected from A-B-A-B type is preferable.
Among these, the ABA type and the ABBA type are more preferable. Of course, these may be a mixture.
[0040]
The block copolymer of an aromatic vinyl compound and a conjugated diene compound that can be used in the present invention is more preferably a hydrogenated block copolymer. The hydrogenated block copolymer is an aliphatic double bond of a polymer block mainly composed of a conjugated diene compound by subjecting the block copolymer of the aromatic vinyl compound and the conjugated diene compound to a hydrogenation treatment. Is controlled in the range of more than 0 and 100%. A preferable hydrogenation rate of the hydrogenated block copolymer is 50% or more, more preferably 80% or more, and most preferably 98% or more.
[0041]
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, it is desirable to use a mixture of a low molecular weight block copolymer and a high molecular weight block copolymer as the block copolymer to be used.
Specifically, it is a mixture of a low molecular weight block copolymer having a number average molecular weight of less than 120,000 and a high molecular weight block copolymer having a number average molecular weight of 120,000 or more.
[0042]
The number average molecular weight referred to in the present invention is measured with an ultraviolet spectroscopic detector [UV-41: Showa Denko KK] using a gel permeation chromatography measuring device [GPC SYSTEM21: 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 due to catalyst deactivation during polymerization may be detected. In this 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.
[0043]
The weight ratio of these low molecular weight block copolymer and high molecular weight block copolymer is low molecular weight block copolymer / high molecular weight block copolymer = 95/5 to 5/95. Preferably it is 90/10-10/90.
In the present invention, as the low molecular weight block copolymer, a block copolymer in which the number average molecular weight of one polymer block mainly composed of an aromatic vinyl compound is 20,000 or more is used. The additional effect of improving the property can be obtained.
[0044]
The number average molecular weight of one polymer block mainly composed of an aromatic vinyl compound can be obtained by the following equation using the number average molecular weight of the block copolymer described above.
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 composed mainly of all aromatic vinyl compounds in the block copolymer. The weight percentage of the block, b is the weight percentage of the polymer block based on all the conjugated diene compounds in the block copolymer, and N is the weight of the polymer block based on the aromatic vinyl compound in the block copolymer. Represents a number. ]
[0045]
In the present invention, a preferred 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. Since the heat resistance can be improved by using a block copolymer having an aromatic vinyl polymer block within this range for the low molecular weight block copolymer, it can be used more suitably.
Furthermore, in the present invention, a low molecular weight block copolymer, a block copolymer containing a polymer block mainly composed of an aromatic vinyl compound in an amount of 55 wt% or more and less than 90 wt%, and an aromatic vinyl compound By making 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.
[0046]
In addition, the block copolymer of the present invention may be prepared by previously mixing an oil mainly composed of paraffin. The processability of the resin composition can be improved by mixing oil mainly composed of paraffin in advance.
In this case, the preferred amount of oil mainly composed of paraffin is 1 to 70 parts by weight with respect to 100 parts by weight of the block copolymer. When 70 parts by weight or more is mixed, the handleability is poor.
The oil mainly composed of paraffin here is a mixture of a hydrocarbon compound having a weight average molecular weight of 500 to 10,000, which is a combination of an aromatic ring-containing compound, a naphthene ring-containing compound, and a paraffinic compound. Yes, the paraffinic compound content is 50% by weight or more.
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.
[0047]
These oils mainly composed of paraffin are commercially available, and examples thereof include PW380 manufactured by Idemitsu Kosan Co., Ltd.
These block copolymers of aromatic vinyl compound-conjugated diene compound are different in bond type, different in aromatic vinyl compound type, different in conjugated diene compound type, unless otherwise contrary to the spirit of the present invention, Used with a mixture of 2-bond vinyl content or 1,2-bond vinyl content different from 3,4-bond vinyl content, different aromatic vinyl compound component content, or different hydrogenation rate It doesn't matter.
[0048]
As the ethylene-α-olefin copolymer that can be used in the present invention, an ethylene-α-olefin copolymer described in JP-A-2001-302911 can be used.
Moreover, the impact improving material used in the present invention may be an impact improving material modified in whole or in part.
As used herein, a modified impact modifier is at least one carbon-carbon double bond or triple bond and at least one carboxylic acid group, acid anhydride group, amino group, hydroxyl group in the molecular structure, or It refers to an impact modifier modified with at least one modifying compound having a glycidyl group.
[0049]
The production method of the modified impact modifier is as follows: (1) In the presence or absence of a radical initiator, the modified compound is melt kneaded and reacted at a temperature in the range of the softening point temperature of the impact modifier to 250 ° C. or less. A method, (2) a method of reacting an impact modifier and a modifying compound in a solution at a temperature below 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. In the absence, a method of reacting the impact modifier and the modifying compound without melting at a temperature below the softening point of the impact modifier may be used, and any of these methods may be used. Further, among (1), the method carried out in the presence of a radical initiator is most preferable.
[0050]
At least one 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 modified compounds as described in the modified polyphenylene ether can be used.
The preferred amount ratio of the polyamide, polyphenylene ether and impact modifier in the present invention is 30 to 70 parts by weight of polyamide, 20 to 50 parts by weight of polyphenylene ether, 5 to 5 parts of impact modifier when the total of these three components is 100 parts by weight. Within the range of 30 parts by weight. More preferably, it is within 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.
[0051]
Next, the conductive filler that can be used in the present invention will be described.
The conductive filler of component (D) that can be preferably used in the present invention is an organic / inorganic filler having the ability to impart conductivity to a non-conductive material, and the shape is granular, plate-like, or flake Both in the form of fibers and fibers can be used.
Specific examples include conductive carbon black, carbon fibrils typified by carbon nanotubes, carbon nanofibers, carbon fibers, graphite, carbon-coated inorganic fillers, aluminum-doped metal oxides, antimony-doped. Inorganic fillers coated with a metal oxide.
[0052]
Among these, conductive carbon black, carbon nanotube, and carbon nanofiber can be used more preferably.
What is conductive carbon black that can be used in the present invention? A carbon black having a dibutyl phthalate (DBP) oil absorption of 250 ml / 100 g or more is preferred, a carbon black having a DBP oil absorption of 300 ml / 100 g or more, more preferably 350 ml / 100 g or more. What is the DBP oil absorption referred to here? It is a value measured by a method defined 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 is preferable, and further 400 cm ² / G or more is more preferable. Examples of commercially available products include Ketjen Black International's Ketjen Black EC and Ketjen Black EC-600JD.
[0053]
The carbon nanotubes that can be used in the present invention include US Pat. No. 4,663,230, US Pat. No. 4,663,230, US Pat. No. 5,165,909, US Pat. No. 5,171,560, US Pat. No. 5,578,543, US Pat. No. 5,589,152. , U.S. Pat. No. 5,650,370, U.S. Pat. No. 6,235,674 and the like. Moreover, the thing of the coil shape which a helix makes a round with the pitch of 1 micrometer or less is also contained. Examples of commercially available products include Hyperion manufactured by Hyperion Catalyst.
[0054]
The carbon nanofiber that can be used in the present invention refers to a carbon-based fiber having a fiber diameter of 75 nm or more, a hollow structure, and many branched structures. Commercially available products include VGCF, VGNF, etc. from Showa Denko Co., Ltd.
Carbon fibers that can be used in the present invention include fibers obtained by firing and carbonizing fibers made from polyacrylonitrile (PAN) or pitch, etc., at a temperature between 1000 ° C. and 3500 ° C. in an inert gas atmosphere. All are included. A preferable fiber diameter is 3-30 micrometers, More preferably, it is 5-20 micrometers.
[0055]
The graphite in the present invention includes naturally produced graphite, as well as those obtained by heating anthracite, pitch, and the like in an arc furnace at a high temperature. The preferred weight average particle size of graphite is in the range of 0.1 to 50 μm. More preferably, it exists in the range of 1-40 micrometers, Most preferably, it exists in the range of 1-30 micrometers.
A preferable amount of these conductive fillers is 0.01 to 5 parts by weight when the amount of all components excluding the conductive filler is 100 parts by weight. More preferably, it is 0.1 to 3 parts by weight. When the amount is less than 0.01 part by weight, the conductivity is not obtained. On the other hand, when the amount exceeds 5 parts by weight, the fluidity deteriorates.
[0056]
Moreover, in this invention, you may add a compatibilizing agent in the case of manufacture of a composition. The main purpose of using the compatibilizer is to improve the physical properties of the polyamide-polyphenylene ether mixture. The compatibilizing agent that can be used in the present invention refers to a polyfunctional compound that interacts with polyphenylene ether, polyamide, or both.
In any case, it is desirable that the resulting polyamide-polyphenylene ether mixture exhibits improved compatibility.
[0057]
Examples of compatibilizers that can be used in the present invention are described in detail in Patent Document 6 and Japanese Patent Application Laid-Open No. 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 preferable amount of the compatibilizing agent in the present invention is 0.1 to 20 parts by weight, more preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the mixture of polyamide and polyphenylene ether.
[0058]
In the present invention, it is essential to previously melt-knead the impact modifier, polyphenylene ether and conductive filler.
The amount of the conductive filler previously melt-kneaded with the impact modifier and polyphenylene ether is an amount of 50 wt% or more and less than 100 wt% when all the conductive fillers used are 100 wt%. More preferably, the amount is 60% or more and less than 99%, most preferably 70% or more and less than 90% by weight.
Further, in the present invention, a more preferable addition form of the impact filler and the conductive filler previously melt-kneaded with polyphenylene ether is a master batch form melt-kneaded with at least one selected from polyphenylene ether, impact modifier and polyamide. It is a method of adding. By making it into the form of a masterbatch in advance, it is possible to exhibit a new effect that the appearance of the surface of the molded piece during molding retention is drastically improved.
[0059]
The ratio of the conductive filler in the master batch is 5 to 40% by weight when the total amount of the master batch is 100% by weight. More preferably, it is 8 to 25% by weight.
As a preferred method for producing the master batch, a melt kneading method using a twin screw extruder or a kneader is preferred. In particular, a method of adding a conductive filler after at least one selected from polyphenylene ether, impact modifier and polyamide is melted is preferable. Specific examples include at least one supply port on each of the upstream side and the downstream side. Using a twin screw extruder or kneader, one or more selected from polyphenylene ether, impact modifier and polyamide is supplied from the upstream supply port, melted, and then a conductive filler is added from the downstream supply port. And melt-kneading.
[0060]
In the present invention, it is essential that the remaining conductive filler excluding the impact modifier and the conductive filler previously melt-kneaded with polyphenylene ether is added after the polyphenylene ether and polyamide are melt-kneaded.
In this case, (1) a method in which polyphenylene ether and all the polyamide are melt-kneaded and then all the remaining conductive filler is added, and (2) the remaining conductive material is melted and kneaded after a part of the polyphenylene ether and polyamide is melt-kneaded. Although the method of adding a filler with the remaining polyamide and melt-kneading is mentioned, the essential requirement in this invention is that a conductive filler is added after polyphenylene ether and polyamide are melt-kneaded.
[0061]
The amount of the remaining conductive filler excluding the conductive filler previously melt-kneaded with the impact modifier and polyphenylene ether is more than 0 and less than 50% by weight when all conductive fillers used are 100% by weight. It is. More preferably, the amount is 1% by weight or more and less than 40% by weight, most preferably 10% by weight or more and less than 30% by weight.
After melt-kneading polyphenylene ether and polyamide, the conductive filler to be added may be added in the form of a master batch in which part or all of the filler is melt-kneaded in advance with polyamide. The preferable concentration of the conductive filler in the master batch in this case 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. %.
[0062]
In the present invention, in addition to the above-described components, additional components may be added as necessary within a range that does not impair the effects of this component.
Examples of additional components are listed below.
Other thermoplastic resins such as polyester and polyolefin, inorganic fillers (talc, kaolin, zonotlite, wollastonite, titanium oxide, potassium titanate, glass fibers, etc.), to increase the affinity between inorganic fillers and resins Known adhesion improvers, flame retardants (halogenated resins, silicone flame retardants, magnesium hydroxide, aluminum hydroxide, organic phosphate compounds, ammonium polyphosphate, red phosphorus, etc.), fluorine-based polymers exhibiting dripping prevention effects , 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, sulfides Zinc, antioxidants, ultraviolet absorbers, light stabilizers and the like.
[0063]
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 of the total amount 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, etc. A twin-screw extruder provided with an upstream supply port and one or more downstream supply ports is most preferable.
[0064]
The melt kneading temperature at this time is not particularly limited, but the conditions under which a suitable composition can be usually obtained can be arbitrarily selected from 240 to 360 ° C.
A preferable manufacturing method of the present invention includes an upstream supply port and two or more downstream supply ports (among the downstream supply ports, the upstream side is the downstream first supply port, and the downstream side is the downstream second supply port. (1) After supplying the amount of 50% by weight or more and less than 100% by weight of the impact modifier, polyphenylene ether and conductive filler from the upstream supply port, and melt-kneading, A method of supplying all of the polyamide from the downstream first supply port and melt-kneading, supplying all of the remaining conductive filler from the downstream second supply port, and further melt-kneading, (2) Impact from the upstream supply port An amount of 50% by weight or more and less than 100% by weight of the improving material, polyphenylene ether and conductive filler is supplied and melt-kneaded, and then a part of the polyamide is supplied from the downstream first supply port and melt-kneaded. Polya from the supply port Supplying all remaining all remaining conductive filler de, including but further method in which melt kneading is not limited thereto.
The composition of the present invention thus obtained can be molded as a molded body of various parts by various conventionally known methods such as injection molding.
[0065]
These various parts include, for example, IC tray materials, chassis of various disk players, electrical / electronic parts such as cabinets, OA parts and machine parts such as various computers and peripheral devices, motorcycle cowls, and automobile fenders. -Door panel-Front panel-Rear panel-Rocker panel-Rear bumper panel-Back door garnish-Emblem garnish-Fuel inlet panel-Over fender-Outer door handle-Door mirror housing-Bonnent air intake-Bumper-Bumper guard-Roof rail- Exterior parts such as roof rail legs, pillars, pillar covers, wheel covers, spoilers, various aero parts, various malls, emblems, and instrument panels - it can be suitably used for interior parts typified by console box trim or the like.
Among these, it can be suitably used for exterior parts of automobiles capable of electrostatic coating. In particular, it can be preferably used for large parts (back door panels, bumpers) and the like that require a low coefficient of linear expansion.
[0066]
DETAILED DESCRIPTION OF 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 CuI and 350 ppm KI as trace stabilizer components
[0067]
(3) Impact modifier
(3-1) High molecular weight block copolymer (hereinafter abbreviated as SEBS-H1)
Bonding format: Polystyrene-hydrogenated polybutadiene-polystyrene
Number average molecular weight: 246,000
Number average molecular weight per polystyrene block: 40,600
Bonded styrene content: 33%
1,2-vinyl content: 33%
Hydrogenation rate of polybutadiene part: 98% or more
[0068]
(3-2) Low molecular weight block copolymer-1 (hereinafter abbreviated as SEBS-L1)
Bonding format: Polystyrene-hydrogenated polybutadiene-polystyrene
Number average molecular weight: 98,500
Number average molecular weight per polystyrene block: 14,300
Bonded styrene content: 29%
1,2-vinyl content: 32%
Hydrogenation rate of polybutadiene part: 98% or more
[0069]
(3-3) Low molecular weight block copolymer-2 (hereinafter abbreviated as SEBS-L2)
Bonding format: Polystyrene-hydrogenated polybutadiene-polystyrene
Number average molecular weight: 115,000
Number average molecular weight per polystyrene block: 34,500
Bonded styrene content: 60%
1,2-vinyl content: 35%
Hydrogenation rate of polybutadiene part: 98% or more
[0070]
(4) Conductive filler
(4-1) Conductive carbon black (hereinafter abbreviated as KB)
Product name: Ketjen Black EC-600JD (Ketjen Black International)
DBP oil absorption: 495ml / 100g
BET surface area: 1270cm ² / G
[0071]
(5) Polyamide masterbatch
(5-1) PA / KB master batch (hereinafter abbreviated as KB-MB)
Using a ZSK-25 twin-screw rotary extruder (manufactured by Werner & Frederer) with one supply port on each of the upstream side and the downstream side, 280 ° C., downstream side from the upstream supply port to the downstream supply port 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, 10 parts by weight of KB is supplied from the downstream supply port, melt-kneaded, and a PA / KB master with a KB concentration of 10% by weight. Got a batch. The screw rotation speed at this time was 400 rpm. At this time, volatile components were removed from the upstream supply port and a vent port capable of vacuum suction installed in front of the die.
[0072]
(5-2) Polyamide 66 / CNT master batch (hereinafter abbreviated as CNT-MB)
Polyamide 66 / CNT masterbatch (trade name: Polyamide 66 with Fiber) manufactured by Hyperion Catalyst ^TM Nanotubes RMB4620-00) was used. The CNT concentration in this master batch is 20% by weight.
[0073]
(6) PPE / SEBS-L1 / KB master batch (hereinafter abbreviated as PPE-MB)
Using the same extruder as that used for KB-MB production, everything from the upstream supply port to the die was set to 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 from the upstream supply port and a vent port capable of vacuum suction installed in front of the die.
(7) Compatibilizing agent: maleic anhydride (hereinafter abbreviated as MAH)
[0074]
(Measuring method)
Volume resistivity (hereinafter abbreviated as VR)
Cut both ends of a 3.2 mm-thick tensile test piece (ASTM D638 Type I dumbbell bar) with a precision cut-and-saw and have a uniform cross-sectional area (12.4 x 3.2 mm) at both ends. A strip-shaped test piece was obtained. After applying silver paste to the cut surfaces at both ends of this test piece and drying it sufficiently, the resistance value between both ends was measured at a voltage of 1.5 V using a tester, and the volume resistivity was calculated using the following equation: Calculated.
In addition, this measurement was implemented with respect to ten different test pieces, and the addition average was made into volume specific resistance value.
[0075]
Linear expansion coefficient
A center portion of a tensile test piece having a height of 3.2 mm was cut into a square column shape having a thickness of 3.2 mm, a width of 5 mm, and a height of 10 mm using a precision cut saw, and TMA-7 (manufactured by PerkinElmer) was used. According to JIS K7197, measurement was performed while increasing the temperature from 23 ° C. to 70 ° C. at a temperature increase rate of 5 ° C./min.
Amount of chips generated during extrusion
A strand bath and a pelletizer were installed at the spout of the extruder, and the take-up speed of the pelletizer was adjusted so that the diameter of the strand before the pelletizer after passing through the strand bath was 2 mm to 3 mm. At this time, the length in which the strand was immersed in the water tank was 100 cm. The water temperature was between 13 ° C and 15 ° C.
About 100 g of the pellets coming out of the pelletizer at this time were taken and weighed precisely. This value is W1.
Next, this precisely weighed pellet was spread on a 20-mesh wire mesh and shaken well to separate the pellet and swarf, and then the weight of the pellet remaining on the wire mesh was precisely weighed. Let this value be W2.
From the obtained W1 and W2, the ratio of the chips (% by weight) was calculated using the following formula.
Weight% of cutting powder = (1−W2 / W1) × 100
[0076]
Fluidity (hereinafter abbreviated as SSP)
Minimum injection pressure (ASTM D638 type I dumbbell bar) that can be filled with an injection molding machine IS-80EPN (manufactured by Toshiba Machine Co., Ltd.) when the injection speed, mold and cylinder temperature settings are constant. Relative comparisons were made with the minimum injection pressure required to fill the tensile specimen. Since this value is a comparison by injection pressure, the smaller the value, the better the fluidity.
At this time, the mold temperature was 80 ° C., and the cylinder temperature was set to 290 ° C.-290 ° C.-280 ° C.-270 ° C. from the nozzle to the hopper side. The molding cycle was 10 seconds of injection, 15 seconds of cooling, and 2 seconds of interval. Moreover, it measured after shape | molding at least 20 shots and making mold temperature constant.
[0077]
Heat resistance (hereinafter abbreviated as HDT)
Based on ASTM D648, the deflection temperature under load was measured at a load of 1.82 MPa. This measurement was carried out on 10 different test pieces, and the HDT value was obtained by averaging the results.
Molded piece surface appearance (hereinafter abbreviated as molded piece appearance)
Using an injection molding machine IS-80EPN, a plate-shaped molded piece having a length of 90 mm, a width of 50 mm, and a thickness of 2.5 mm was molded and visually evaluated. The molding conditions at this time are the same as the molding conditions at the time of SSP measurement.
[0078]
Surface appearance when the molding machine stays (hereinafter abbreviated as appearance after staying)
The cylinder temperature setting of the injection molding machine IS-80EPN is 310 ° C-310 ° C-300 ° C-290 ° C from the nozzle to the hopper side, and about 20 flat plate shaped pieces with a length of 90mm, a width of 50mm, and a thickness of 2.5mm are formed. After that, the cycle of the molding machine was stopped for 2 minutes, and the resin composition was retained in the cylinder. Then, shaping | molding was started and the surface external appearance of the flat molded piece of the 1st shot was evaluated visually.
A three-step evaluation was carried out, with x indicating that the silver-like marks (silver) appeared on the entire surface of the molded piece, Δ indicating what appeared even a little, and ○ indicating that none appeared.
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.
[0079]
Examples 1 to 3 and Comparative Example 1
1 upstream port and 2 downstream ports (among 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 a co-rotating twin-screw extruder ZSK-40 (manufactured by Werner & Friederer) having 320 is 320 ° C. from the upstream supply port to the downstream first supply port, and 280 from the downstream first supply port to the die. The temperature was set at 0 ° C., and the mixture was supplied from the upstream supply port, the downstream first supply port, and the downstream second supply port in the ratios shown in Table 1, melt-kneaded, and pelletized.
In addition, the screw rotation speed at this time was 300 rpm, and vacuum suction was implemented in two places before the downstream 1st supply port and die | dye for the removal of a volatile component.
The obtained pellets were injection molded into various test pieces with an IS-80EPN molding machine. At this time, SSP was measured simultaneously. Volume resistance and linear expansion coefficient were measured using the obtained test piece. Each physical property value is shown in Table 1.
Even with the same conductive filler content, by adding the conductive filler from the upstream supply port, the balance between the volume resistivity and the linear expansion coefficient is excellent, and the generation of chips is greatly suppressed. I understand.
[0080]
Examples 4 to 6
All were carried out in the same manner as in Example 1 except that the feed was supplied at the ratio shown in Table 2 from each supply port. Here, fluidity and HDT were also measured. Each physical property value is shown in Table 2.
Comparing Examples 2 and 4, it can be seen that the fluidity is improved by using a high molecular weight block copolymer and a low molecular weight block copolymer in combination with the impact modifier.
In addition, Example 5 using a block copolymer having a sufficient molecular weight of a polystyrene block as a low molecular weight block copolymer and having a large amount of bound styrene significantly improved HDT compared to Example 4. I know that.
Further, in Example 6 in which the low molecular weight block copolymer was made of two types of blends having different amounts of bound styrene, HDT and fluidity were significantly improved as compared with Examples 2, 4 and 5. I understand.
[0081]
[Example 7]
All were carried out in the same manner as in Example 4 except that the feed was supplied from each supply port at the rate shown in Table 3. Each physical property value is shown in Table 3.
It can be seen that the same physical properties are maintained even when carbon nanotubes are used as the conductive filler in addition to the conductive carbon black.
[0082]
Examples 8 to 10
All were carried out in the same manner as in Example 4 except that the feed was supplied from each supply port at the rate shown in Table 4. In addition, the appearance after residence was also measured here. Each physical property value is shown in Table 4.
By changing the additive form of impact filler and conductive filler that is pre-melted and kneaded with polyphenylene ether to the masterbatch form, the surface appearance when the molding machine stays can be dramatically improved while maintaining other physical properties. I understand.
[0083]
[Table 1]

[0084]
[Table 2]

[0085]
[Table 3]

[0086]
[Table 4]

[0087]
【The invention's effect】
The composition of the present invention has an excellent balance between conductivity (volume resistivity) and linear expansion coefficient by optimizing the addition position and addition ratio of the conductive filler. It is.

Claims (18)

A resin composition comprising (A) polyamide, (B) polyphenylene ether, (C) impact modifier and (D) conductive filler,
Step a: a step of melt-kneading the component (B), the component (C) and the component (D),
Step b Step of melt-kneading the composition obtained in step a and all or part of component (A) and step c The composition obtained in step b, the remaining component (D), and the rest if necessary The component (A) is obtained through a step of melt-kneading the component, and the amount of the component (D) in the step a is 50% by weight or more and less than 100% by weight when all the components (D) are 100% by weight. A conductive resin composition characterized by the above. A part or all of the component (D) in the step a is added in the form of a masterbatch previously melt-kneaded with one selected from the component (A), the component (C) and the component (A). The resin composition as described. The conductive resin composition according to claim 1 or 2, wherein the amount of the component (D) in step a is 70% by weight or more and less than 90% by weight when all the components (D) are 100% by weight. The conductive resin composition according to claim 1, wherein the component (D) in step c is added in the form of a masterbatch that is previously melt-kneaded with the component (A). 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, and the bonding form of the polymer segments is AB type. The conductive resin composition according to claim 1, which is an aromatic vinyl compound-conjugated diene compound block copolymer and / or a hydrogenated product thereof, which is at least one selected from the group consisting of ABA type and ABAB type. 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. Conductive resin composition. The component (C-2) is a block copolymer having a number average molecular weight of a polymer block [A] mainly composed of an aromatic vinyl compound and having a number average molecular weight of 20,000 or more. Conductive resin composition. The conductive resin composition according to claim 1, wherein the component (C-2) is a block copolymer containing an aromatic vinyl compound in an amount of 55 wt% or more and less than 90 wt%. . The conductive resin composition according to claim 1, wherein the component (D) is at least one selected from conductive carbon black, carbon nanotube, carbon nanofiber, carbon fiber, and graphite. The conductive resin composition according to claim 1, wherein the component (D) is conductive carbon black having a DBP oil absorption of 250 ml / 100 g or more. The conductive resin composition according to claim 1, 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 1, wherein the component (D) is a carbon nanofiber having an average fiber diameter of 75 nm or more and less than 1000 nm. (D) The quantity of a component is 0.1-3 weight part with respect to a total of 100 weight part of (A)-(C) component, The electroconductivity in any one of Claims 1-4 or 9-12 Resin composition. When the amount ratio of the components (A) to (C) is 100 parts by weight of the total of these three components, (A) component 30 to 70 parts by weight, (B) component 20 to 50 parts by weight, (C) It is 5-30 weight part of components, The conductive resin composition in any one of Claims 1-12. 5. The conductive resin composition according to claim 4, wherein the amount of the component (D) in the master batch in which the component (D) and the component (A) in step c are previously melt-kneaded is 5 to 40% by weight. An injection-molded article comprising the conductive resin composition according to any one of claims 1 to 13. The molded object for motor vehicle exterior which consists of a conductive resin composition in any one of Claims 1-4. A resin composition comprising (A) polyamide, (B) polyphenylene ether, (C) impact modifier and (D) conductive filler,
Step a: a step of melt-kneading the component (B), the component (C) and the component (D),
Step b Step of melt-kneading the composition obtained in step a and all or part of component (A) and step c The composition obtained in step b, the remaining component (D), and the rest if necessary The component (A) is obtained through a step of melt-kneading the component, and the amount of the component (D) in the step a is 50% by weight or more and less than 100% by weight when all the components (D) are 100% by weight. The manufacturing method of the conductive resin composition characterized by the above-mentioned.