JP4291012B2 - Conductive resin composition - Google Patents

Description

（式中、Ｒ₁、Ｒ₂、Ｒ₃、Ｒ₄及びＲ₅は、それぞれ水素原子、ハロゲン原子、炭化水素基又は置換炭化水素基から選ばれたものであり、そのうち必ず１個は水素原子である。）
【００１０】
上記一般式におけるＲ₁、Ｒ₂、Ｒ₃、Ｒ₄及びＲ₅の具体例としては、水素、塩素、臭素、フッ素、ヨウ素、メチル、エチル、ｎ−又はｉｓｏ−プロピル、ｐｒｉ−、ｓｅｃ−又はｔ−ブチル、ヒドロキシエチル、フェニルエチル、ベンジル、ヒドロキシメチル、カルボキシエチル、メトキシカルボニルエチル、シアノエチル、フェニル、メチルフェニル、ジメチルフェニル、エチルフェニル、アリルなどがあげられる。
【００１１】
上記一般式の具体例としては、フェノール、ｏ−、ｍ−又はｐ−クレゾール、２，６−、２，５−、２，４−又は３，５−ジメチルフェノール、２−メチル−６−フェニルフェノール、２，６−ジフェニルフェノール、２，６−ジエチルフェノール、２−メチル−６−エチルフェノール、２，３，５−、２，３，６−又は２，４，６−トリメチルフェノール、３−メチル−６−ｔ−ブチルフェノール、チモール、２−メチル−６−アリルフェノールなどがあげられる。更に、上記一般式以外のフェノール化合物、たとえば、ビスフェノール−Ａ、レゾルシン、ハイドロキノン、ノボラック樹脂のような多価ヒドロキシ芳香族化合物と上記一般式で示されるフェノール化合物とを共重合体の原料としてもよい。これらの化合物の中では、２，６−ジメチルフェノール、２，６−ジフェニルフェノール、３−メチル−６−ｔ−ブチルフェノール及び２，３，６−トリメチルフェノールが好ましい。
【００１２】
フェノール化合物を酸化重合せしめる際に用いる酸化カップリング触媒は、特に限定されるものではなく、重合能を有する如何なる触媒でも使用できる。
かかるポリフェニレンエーテル系樹脂の製造法は、たとえば米国特許第３３０６８７４号公報、同第３３０６８７５号公報及び同第３２５７３５７号公報並びに特公昭５２−１７８８０号公報、特開昭５０−５１１９７号公報、特開平１−３０４１１９号公報等に記載されている。
【００１３】
本発明におけるポリフェニレンエーテル系樹脂の具体例としては、ポリ（２，６−ジメチル−１，４−フェニレンエーテル）、ポリ（２，６−ジエチル−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−プロピル−１，４−フェニレンエーテル）、ポリ（２，６−ジプロピル−１，４−フェニレンエーテル）、ポリ（２−エチル−６−プロピル−１，４−フェニレンエーテル）、ポリ（２，６−ジブチル−１，４−フェニレンエーテル）、ポリ（２，６−ジプロペニル−１，４−フェニレンエーテル）、ポリ（２，６−ジラウリル−１，４−フェニレンエーテル）、ポリ（２，６−ジフェニル−１，４−フェニレンエーテル）、ポリ（２，６−ジメトキシ−１，４−フェニレンエーテル）、ポリ（２，６−ジエトキシ−１，４−フェニレンエーテル）、ポリ（２−メトキシ−６−エトキシ−１，４−フェニレンエーテル）、ポリ（２−エチル−６−ステアリルオキシ−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−メチル−１，４−フェニレンエーテル）、ポリ（２−エトキシ−１，４−フェニレンエーテル）、ポリ（３−メチル−６−ｔ−ブチル−１，４−フェニレンエーテル）、ポリ（２，６−ジベンジル−１，４−フェニレンエーテル）及びこれらの重合体を構成する繰り返し単位の複数種を含む各種共重合体をあげることができる。共重合体の中には２，３，６−トリメチルフェノール、２，３，５，６−テトラメチルフェノール等の多置換フェノールと２，６−ジメチルフェノールとの共重合体等も含む。これらポリフェニレンエーテル系樹脂のうちで好ましいものはポリ（２，６−ジメチル−１，４−フェニレンエーテル）及び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である。
【００１４】
本発明で使用できるポリフェニレンエーテル系樹脂は、３０℃のクロロホルム中で測定した固有粘度が０．３〜０．６ｄｌ／ｇのものが好ましく、更に好ましくは０．３２〜０．５５ｄｌ／ｇであり、最も好ましくは０．３４〜０．５ｄｌ／ｇである。該固有粘度が、低すぎると耐衝撃強度が低下する場合があり、一方該固有粘度が、高すぎると溶融時の流動性が低下し、成形加工性が低下する場合がある。
【００１５】
本発明で用いるポリフェニレンエーテル系樹脂は、上記重合体、共重合体に対し、スチレン、α−メチルスチレン、ｐ−メチルスチレン及びビニルトルエン等のスチレン系化合物をグラフトさせて変性した共重合体でもよい。
【００１６】
アルケニル芳香族系樹脂とは、式（II）で示される芳香族ビニル単量体から誘導された繰り返し構造単位を、その重合体中に少なくとも２５重量％以上有するものである。

【００１７】
ここで、Ｒ₆は水素、低級アルキル又はハロゲン；Ｚは水素、ビニル、ハロゲン、アミノ基、水酸基又は低級アルキル；そしてｐは０又は１〜５の整数である。上記低級アルキルとは、炭素数１〜６のアルキル基をいう。（II）として、たとえば、スチレン、α−メチルスチレン、α−クロロスチレン、ビニルトルエン、ジビニルベンゼン等があげられる。また、該化合物は１種だけに限らず２種以上を併用することもできる。
【００１８】
かかるアルケニル芳香族系樹脂としては、スチレンもしくはその誘導体たとえば、ｐ−メチルスチレン、 α−メチルスチレン、α−メチル−ｐ−メチルスチレン、クロロスチレン、ブロモスチレン等の単独重合体及び共重合体があげられる。また、上記した芳香族ビニル系化合物を７０〜９９重量％とジエンゴム１〜３０重量％とからなるゴム変性された高衝撃性ポリスチレン（ＨＩＰＳ）を使用することができる。ＨＩＰＳを構成するジエンゴムとしては、ブタジエン、イソプレン、クロロプレン等の共役ジエン系化合物の単独重合体、共役ジエン系化合物と不飽和ニトリル化合物又は芳香族ビニル化合物との共重合体更には天然ゴムなどがあげられ、これらを１種又は２種以上用いる事ができる。特に、ポリブタジエン、ブタジエンースチレン共重合体が好ましい。ＨＩＰＳは、乳化重合、懸濁重合、塊状重合、溶液重合又は、それらの組み合わせの方法によって得られる。
【００１９】
本発明においては、樹脂成分として、必須のポリフェニレンエーテル系樹脂及び／又はアルケニル芳香族系樹脂は、成形品に必要とされる耐熱性を有していれば良く、単独または配合して熱可塑性樹脂組成物に用いることができる。
【００２０】
本発明においては、樹脂成分として、必須のポリフェニレンエーテル系樹脂及び／又はアルケニル芳香族系樹脂からなる熱可塑性樹脂組成物に、成形品に加工した場合に必要とされる特性を付与するための各種の改質材を配合していても良く、耐衝撃強度を付与するためのゴム様物質や、剛性や寸法安定性等を付与する非導電性フィラー等の改質材の配合が、実用的に優れる成形品を得るために好ましい。
【００２１】
ゴム様物質とは、室温で弾性体である天然及び合成の重合体材料をいう。特に好ましいゴムとしては、エチレン−プロピレン共重合ゴム、エチレン−プロピレン−非共役ジエン共重合ゴム、エチレン−ブテン−１共重合ゴム、ポリブタジエン、スチレン−ブタジエンブロック共重合ゴム、スチレン−ブタジエン共重合ゴム、部分水添スチレン−ブタジエン−スチレンブロック共重合ゴム、スチレン−イソプレンブロック共重合ゴム、部分水添スチレン−イソプレンブロック共重合ゴム、ポリウレタンゴム、スチレングラフト−エチレン−プロピレン−非共役ジエン共重合ゴム、スチレン−グラフト−エチレン−プロピレン共重合ゴム、スチレン／アクリロニトリル−グラフト−エチレン−プロピレン−非共役ジエン共重合ゴム、スチレン／アクリロニトリル−グラフト−エチレン−プロピレン共重合ゴム、スチレン／メチルメタアクリレート−グラフト−エチレン−プロピレン−非共役ジエン共重合ゴム、スチレン／メチルメタアクリレート−グラフト−エチレン−プロピレン共重合ゴム等、あるいはこれらの混合物が用いられる。また、他の酸もしくはエポキシなどを含む官能性単量体により変性した変性ゴムを用いてもよい。
【００２２】
ゴム様物質の配合量は成分（Ａ）中に重量比で０〜５０重量％が好ましく、更に好ましくは２〜４０である。ゴム成分が充分でないと耐衝撃性の低下や成形品が脆くなる場合があり、過多であると機械的強度が低下する場合がある。
【００２３】
非導電性無機フィラーとしては、たとえばタルク、マイカ、ガラス繊維、シリカアルミナ、炭酸カルシウム、クレー、カオリン、硫酸マグネシウム、ウォラストナイト、ＴｉＯ₂、ＺｎＯ及びＳｂ₂Ｏ₃のような無機充填剤を用いることができる。成形品の加熱処理後の寸法安定性の向上の観点から、好ましくは板状の非導電性無機フィラーであり、タルク及びマイカの様な非導電性無機フィラーであり、更に好ましくは添加による耐衝撃性の低下が少ないタルクである。
【００２４】
非導電性無機フィラーの配合量は成分（Ａ）中に重量比で０〜１５重量％が好ましく、更に好ましくは０〜１３重量％である。非導電性無機フィラーが充分でないと成形品の加工時の収縮や成形品を加熱処理した際の寸法安定性が不十分なものとなり、過多であると機械的強度や耐衝撃性が低下し成形品が脆い。
【００２５】
本発明の成分（Ｂ）は、成分（Ａ）に配合し混練することで導電性を付与することができる導電性カーボンブラックであり、かさ密度０．１５ｇ／ｍｌ以上、ＤＢＰ吸油量１７５から２０５ｍｌ／１００ｇかつ平均粒子径３８から４２ｎｍの性状ものである。
【００２６】
本発明において使用できる成分（Ｂ）のかさ密度は０．１５ｇ／ｍｌ以上であり、好ましくは０．１７ｇ／ｍｌ以上である。かさ密度が０．１５ｇ／ｍｌ以下であると成分（Ａ）に配合し混練する際に均一に分散しなかったり、導電性カーボンブラックや配合した原料が混練装置に安定して供給できない等、充分な混練性が得られず、導電性樹脂組成物の安定した品質での生産や製造が行えない。
【００２７】
ＤＢＰ吸油量１７５から２０５ｍｌ／１００ｇかつ平均粒子径３４から４２ｎｍの範囲であり、好ましくはＤＢＰ吸油量１８０から２００ｍｌ／１００ｇかつ平均粒子径３６から４０ｎｍの範囲でこの範囲以下の導電性カーボンブラックでは、耐衝撃性が低く、導電性が十分でない場合には必要な配合量が多くなる等で耐衝撃性がさらに低下する場合があり、この範囲以上の導電性カーボンブラックでは、必要な導電性を付与するための配合量は少なくなるが耐衝撃性が低下し、成形品が脆くなる場合がある。
【００２８】
本発明において使用できる導電性カーボンブラックはイオウ含量０．０５％以下であり、さらに好ましくは０．０３％以下であり、イオウ含量が多い場合には独特の臭気が発生し金属の表面を曇らせる等の問題があり好ましくない。
本発明において使用できる導電性カーボンブラックは、かさ密度、ＤＢＰ吸油量、平均粒子径が特定の範囲で、イオウ含量が少ないことが好ましく、導電性ファーネスブラックのエンサコ社のＭＭＭカーボン製造法により製造されたエンサコ２５０Ｇなるカーボンブラックが適している。
【００２９】
成分（Ｂ）の配合量は、成分（Ａ）に配合混練した導電性樹脂組成物の成形品に必要とされる導電性や帯電防止性が得られる量であり、（Ａ）／（Ｂ）の重量比が８０／２０〜９０／１０であり、好ましく８３／１７〜８７／１３であり、成分（Ｂ）の配合量が、この範囲以下の場合は導電性が不足し、この範囲以上の場合には導電性は向上するが成形品が脆く実用に適さなくなり、混練性が悪くなる。
【００３０】
本発明の樹脂組成物は、上記の成分に加えて、慣用の添加剤、たとえば顔料、難燃剤、可塑剤、酸化防止剤及び耐候剤等を含有してもよい。
【００３１】
本発明の樹脂組成物の製造方法は限定されない。たとえば、用いる成分を公知の方法で配合し、溶融混練すればよいが、その際の混合手段としては慣用の混合手段で混合することができる。このために押出機、ニーダー、ロールミキサー及びバンバリーミキサー等が使用できる。
【００３２】
本発明の樹脂組成物は、導電性あるいは帯電防止性の成形品である電子部品やＩＣパッケージを包装する容器に公知の方法で加工でき、例えば、射出成形によるハードトレーや、単層または多層の導電シートに加工の後、真空成形等によりソフトキャリアテープに成形され得るが、本発明はこれらに限定されるものではない。
【００３３】
【実施例】
以下に示される方法により、本発明は実施が可能であるが、本発明はこれらに限定されるものではない。
【００３４】
実施例においては次の化合物を使用した。
成分（Ａ）
ＰＰＥ：ポリフェニレンエーテル系樹脂；ＰＰＯ６４６ ＧＥ社製；極限粘度（クロロホルム、２５℃）０．４６ｄｌ／ｇ
ＧＰＰＳ：ポリスチレン系樹脂；Ｇ８９９ 日本ポリスチレン株式会社製；
ＳＭＥＰＲ：ゴム様物質；参考例１に示す製造法にて製造されたスチレン／メチルメタクリレート−グラフト−エチレン−プロピレン−非共役ジエン共重合ゴム
ＨＳ−Ｔ：非導電性無機フィラー；ＭＷ ＨＳ−Ｔ 林化成社製タルク；平均粒子径（Ｄ５０）２．７５μｍ
成分（Ｂ）
表１に符号ＣＢ−１〜ＣＢ−５で表した導電性カーボンブラックを使用した。
【００３５】
参考例１
ゴム様物質として、スチレン／メチルメタクリレート−グラフト−エチレン−プロピレン−非共役ジエン共重合ゴムを下記の方法で製造した。
攪拌機を備えた５リットルのオートクレーブに、分散剤として旭電化株式会社製プルロニックＦ６８ ６ｇを溶解した純水２２００ｍｌ及び３〜６ｍｍ角に細断したエスプレンＥ５０２（プロピレン含量４４重量部、ヨウ素価８．５、１２０℃におけるムーニー粘度６３）を３００ｇ仕込み、攪拌して懸濁させた。次いで重合開始剤としてｔ−ブチルパーオキシピバレート９ｇ及びＰ−ベンゾキノン０．１８ｇ、単量体としてスチレン１０１ｇとメチルメタクリレート１９ｇを加え、直ちにオートクレーブを３０℃に予め昇温しておいたオイルバス中に入れて昇温を開始する。１分間に約１℃の割合で１１０℃まで昇温し、そのまま３０分間温度を１１０℃に保ち、重合反応を行った。生成した粒状のグラフト物は水洗後９５℃で真空乾燥し、スチレン／メチルメタクリレート−グラフト−エチレン−プロピレン−非共役ジエン共重合ゴム（ＳＭＥＰＲ）を得た。
【００３６】
表２及び３に示す割合の各成分をブレンドした後、ＴＥＭ−５０Ａ（東芝機械製 ５０ｍｍの二軸押出機）とＩＳ２２０ＥＮ（東芝機械製 型締め力２２０ｔｏｎの射出成形機）を用いて、表４に示した条件にて溶融混練し押出したストランドを水槽にて水冷却後にストランドカッターで切断しペレット化を行い造粒を行った後、得られたペレットを１３０℃３時間の熱風乾燥後、表４に示した条件にて射出成形して試験片を成形し、各種評価を行った。これらの評価結果を表２及び３に示す。
【００３７】
評価は以下のようにして行った。
混練性：上記の通り導電性樹脂組成物を製造するに際して、連続的に混練、造粒できる場合を○、できない場合を×で表した。
（１）表面抵抗値（以下ＳＲと言う）：ＡＳＴＭ Ｄ２５７に準拠して、厚み３．２ｍｍの試験片について測定した。単位はΩ。
（２）アイゾッド衝撃強度（以下Ｉｚｏｄと言う）：ＡＳＴＭ Ｄ２５６に準拠して、厚み３．２ｍｍの試験片について、Ｖノッチ付きで測定した。単位はｋＪ／ｍ^２。
（３）臭気：金属表面を曇らせる等の原因とされる臭気がペレットにない場合を○、ある場合を×で表した。
（４）判定：混練性、臭気が○であり、導電性樹脂組成物成形品において他の導電性カーボンブラックを配合した場合よりも、ＳＲが低抵抗で導電性に優れ、Ｉｚｏｄの値が高く耐衝撃性に優れる場合を○、そうでない場合を×で表した。
【００３８】
【表１】

【００３９】
【表２】

【００４０】
【表３】

【００４１】
【表４】

【００４２】
実施例１〜２
表２に示す割合及び表４の条件で東芝機械製ＴＥＭ５０二軸混練機にて溶融混練し導電性樹脂組成物の造粒を行い、得たペレットを用いて東芝機械製ＩＳ２２０ＥＮ射出成形機により成形品に加工し、混練性、ＳＲ、Ｉｚｏｄ、臭気を評価した。結果を表２に示す。
【００４３】
本願の発明の組成物にもとづく、実施例１では、特定の性状を有する導電性カーボンブラックを配合した導電性樹脂組成物は、混練性、ＳＲ、Ｉｚｏｄが優れ、問題となる臭気の発生もなく好ましい導電性樹脂組成物が得られることを示す。
【００４４】
実施例２では、特定の性状を有する導電性カーボンブラックの配合量を減じた場合であり、必要とされる導電性が実施例１よりも向上した導電性樹脂組成物が得られることを示す。
【００４５】
比較例１〜５
表３に示す割合及び表４の条件で東芝機械製ＴＥＭ５０二軸混練機にて溶融混練し導電性樹脂組成物の造粒を行い、得たペレットを用いて東芝機械製ＩＳ２２０ＥＮ射出成形機により成形品に加工し、混練性、ＳＲ、Ｉｚｏｄ、臭気を評価した。結果を表３に示す。
【００４６】
本発明の組成物にもとづかない、比較例を示す。
比較例１と２では、実施例と同種であるが特定の性状を有さない導電性ファーネスブラックを配合した導電性樹脂組成物は、混練性は優れるが、ＳＲ、Ｉｚｏｄが劣る導電性樹脂組成物が得られ、問題となる臭気の発生があり好ましくないことを示す。
【００４７】
比較例３と４では、実施例と別種で特定の性状を有さないケッチェンブラックを配合した導電性樹脂組成物であり、比較例３では、配合量に対して効率の良く導電性を付与できるが、ＳＲ、Ｉｚｏｄが劣り、ＳＲを向上させるために配合量を増した比較例４では、混練性が悪化し造粒が行えずペレットが得られなかったことを示す。
【００４８】
比較例５では、実施例と別種な特定の性状を有さないアセチレンブラックを配合した導電性樹脂組成物であり、混練性に優れ、問題となる臭気の発生のない好ましい導電性樹脂組成物が得られるが、ＳＲ、Ｉｚｏｄが劣っていることを示す。
【００４９】
【発明の効果】
本発明によれば、ポリフェニレンエーテル系樹脂及び／又はアルケニル芳香族系樹脂からなる熱可塑性樹脂組成物を必須の樹脂成分とし、特定の性状を有する導電性カーボンブラックの配合により、他の性状の導電性カーボンブラックを配合した場合よりも導電性と耐衝撃性に優れた導電性樹脂組成物が得られ、さらに、特定の性状を有する導電性カーボンブラックでは、必要とする導電性を配合量に対して効果的に付与できるため配合量を減ずることにより、導電性カーボンブラックの配合により低下する耐衝撃性の低下を抑え、耐衝撃性をさらに高めた成形品を提供することができる導電性樹脂組成物を得ることができる。
【００５０】
比較例で示したように、成分（Ｂ）が特定の性状を有する導電性カーボンブラックでない場合には、配合混練して得られる導電性樹脂組成物の成形品のＳＲとＩｚｏｄに対して、実施例からも明らかな通り、特定の性状を有する導電性カーボンブラックを配合混練して得られる導電性樹脂組成物の成形品のＳＲとＩｚｏｄは、より優れていることが分かる。本発明の導電性樹脂組成物は、導電性と耐衝撃性が優れた成形品に成形でき、電子部品やＩＣパッケージを包装する容器に成形して使用し得る。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a conductive resin composition. More specifically, the present invention uses a thermoplastic resin composition comprising a polyphenylene ether resin and / or an alkenyl aromatic resin as an essential resin component, and is excellent in kneadability by blending conductive carbon black having a specific property. The present invention relates to a conductive resin composition that can provide a molded article having excellent conductivity and antistatic properties and high impact resistance.
[0002]
[Prior art]
Containers for packaging electronic components and IC packages require surface conductivity in order to protect the contents from the effects of static electricity. Conductive resin with conductive carbon black added to various resins. A composition is used.
[0003]
The conductive resin composition imparted with conductivity by blending conductive carbon black has a problem in practicality due to a decrease in mechanical strength and impact resistance. For the purpose of increasing the impact strength of a molded product comprising the above, the use of high impact polystyrene and an ABA 'type block copolymer is shown. Patent Document 2 discloses an improvement in impact strength of a conductive resin composition. Although it has been shown that a polymer is added, the properties of conductive carbon black, which is essential for obtaining conductivity, are described in Patent Document 3. In order to provide conductivity, it is said that a DBP oil supply amount of 70 ml / 100 g or more is suitable for providing conductivity. Therefore, no measures for improving the impact strength by examining the properties of the conductive carbon black have been proposed.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2-175754 [Patent Document 2]
Japanese Patent Laid-Open No. 5-57214 [Patent Document 3]
JP 58-108242 A [Patent Document 4]
Japanese Patent Laid-Open No. 5-271532
[Problems to be solved by the invention]
The problem to be solved by the present invention is that a thermoplastic resin composition comprising a polyphenylene ether resin and / or an alkenyl aromatic resin is an essential resin component, and the surface of the resin composition is blended with conductive carbon black having specific properties. excellent resistance value is 10 ⁶ Omega less is conductive or 10 ⁶ to 10 ¹¹ Omega antistatic property and provide a conductive resin composition and molded article can provide a high impact resistance moldings It is in the point to do.
[0006]
[Means for solving the problems]
The present inventors have obtained a highly practical molded product by improving the impact resistance of the conductive resin composition, and are suitable for containers for packaging electronic parts and IC packages having excellent conductivity and impact resistance. In order to develop a functional resin composition, intensive studies have been continued. As a result, it has been found that it is useful to blend a conductive carbon black having specific properties with a thermoplastic resin composition comprising a polyphenylene ether resin and / or an alkenyl aromatic resin as an essential resin component, The present invention has been completed.
[0007]
That is, the present invention uses a thermoplastic resin composition composed of a polyphenylene ether resin and / or an alkenyl aromatic resin as an essential resin component, and blends conductive carbon black having a specific property into another conductive property. Conductive resin composition with better electrical conductivity and impact resistance than when blended with conductive carbon black is obtained. Furthermore, with conductive carbon black having specific properties, the required conductivity is Conductive resin composition capable of providing a molded product with further improved impact resistance by reducing the blending amount, thereby reducing the impact resistance drop caused by the blending of conductive carbon black. A conductive resin composition containing components (A) and (B) and having a weight ratio of (A) / (B) of 80/20 to 90/10 .
(A): a thermoplastic resin composition comprising a polyphenylene ether resin and / or an alkenyl aromatic resin (B): conductive carbon black, bulk density of 0.15 g / ml or more, DBP oil absorption of 175 to 205 ml / 100 g and Average particle size 34 to 42 nm
The second invention of the present invention relates to a conductive or antistatic molded product obtained by molding the above resin composition.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Component (A) of the present invention is a thermoplastic resin composition comprising a polyphenylene ether resin and / or an alkenyl aromatic resin.
[0009]
The polyphenylene ether-based resin is a (co) polymer obtained by oxidative polymerization of one or more phenolic compounds represented by the following general formula (I) with oxygen or an oxygen-containing gas using an oxidative coupling catalyst. is there.

(Wherein R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each selected from a hydrogen atom, a halogen atom, a hydrocarbon group or a substituted hydrocarbon group, one of which must be a hydrogen atom) .)
[0010]
Specific examples of R ₁ , R ₂ , R ₃ , R ₄ and R _{5 in} the above general formula include hydrogen, chlorine, bromine, fluorine, iodine, methyl, ethyl, n- or iso-propyl, pri-, sec- Alternatively, t-butyl, hydroxyethyl, phenylethyl, benzyl, hydroxymethyl, carboxyethyl, methoxycarbonylethyl, cyanoethyl, phenyl, methylphenyl, dimethylphenyl, ethylphenyl, allyl and the like can be mentioned.
[0011]
Specific examples of the general formula include phenol, o-, m- or p-cresol, 2,6-, 2,5-, 2,4- or 3,5-dimethylphenol, 2-methyl-6-phenyl. Phenol, 2,6-diphenylphenol, 2,6-diethylphenol, 2-methyl-6-ethylphenol, 2,3,5-, 2,3,6- or 2,4,6-trimethylphenol, 3- Examples thereof include methyl-6-tert-butylphenol, thymol, 2-methyl-6-allylphenol. Further, a phenol compound other than the above general formula, for example, a polyhydric hydroxy aromatic compound such as bisphenol-A, resorcin, hydroquinone, novolak resin and a phenol compound represented by the above general formula may be used as a raw material of the copolymer. . Among these compounds, 2,6-dimethylphenol, 2,6-diphenylphenol, 3-methyl-6-tert-butylphenol and 2,3,6-trimethylphenol are preferable.
[0012]
The oxidative coupling catalyst used for oxidative polymerization of the phenol compound is not particularly limited, and any catalyst having polymerization ability can be used.
For example, US Pat. Nos. 3,306,874, 3,306,875, and 3,257,357, Japanese Patent Publication No. 52-17880, Japanese Patent Laid-Open No. 50-51197, and Japanese Patent Laid-Open No. Hei 1 -304119 and the like.
[0013]
Specific examples of the polyphenylene ether resin in the present invention include poly (2,6-dimethyl-1,4-phenylene ether), poly (2,6-diethyl-1,4-phenylene ether), and poly (2-methyl). -6-ethyl-1,4-phenylene ether), poly (2-methyl-6-propyl-1,4-phenylene ether), poly (2,6-dipropyl-1,4-phenylene ether), poly (2 -Ethyl-6-propyl-1,4-phenylene ether), poly (2,6-dibutyl-1,4-phenylene ether), poly (2,6-dipropenyl-1,4-phenylene ether), poly (2 , 6-dilauryl-1,4-phenylene ether), poly (2,6-diphenyl-1,4-phenylene ether), poly (2,6-dimethoxy-1,4-phenylene ether) Enylene ether), poly (2,6-diethoxy-1,4-phenylene ether), poly (2-methoxy-6-ethoxy-1,4-phenylene ether), poly (2-ethyl-6-stearyloxy-) 1,4-phenylene ether), poly (2-methyl-6-phenyl-1,4-phenylene ether), poly (2-methyl-1,4-phenylene ether), poly (2-ethoxy-1,4- Phenylene ether), poly (3-methyl-6-tert-butyl-1,4-phenylene ether), poly (2,6-dibenzyl-1,4-phenylene ether) and the repeating units constituting these polymers. Various copolymers including a plurality of types can be given. The copolymer includes a copolymer of a polysubstituted phenol such as 2,3,6-trimethylphenol and 2,3,5,6-tetramethylphenol and 2,6-dimethylphenol. Among these polyphenylene ether resins, preferred are poly (2,6-dimethyl-1,4-phenylene ether) and a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol.
[0014]
The polyphenylene ether resin that can be used in the present invention preferably has an intrinsic viscosity measured in chloroform at 30 ° C. of 0.3 to 0.6 dl / g, more preferably 0.32 to 0.55 dl / g. Most preferably, it is 0.34 to 0.5 dl / g. If the intrinsic viscosity is too low, the impact strength may be lowered. On the other hand, if the intrinsic viscosity is too high, the fluidity at the time of melting may be lowered, and the moldability may be lowered.
[0015]
The polyphenylene ether resin used in the present invention may be a copolymer modified by grafting a styrene compound such as styrene, α-methylstyrene, p-methylstyrene and vinyltoluene to the polymer or copolymer. .
[0016]
The alkenyl aromatic resin is a polymer having at least 25% by weight or more of repeating structural units derived from an aromatic vinyl monomer represented by the formula (II).

[0017]
R ₆ is hydrogen, lower alkyl or halogen; Z is hydrogen, vinyl, halogen, amino group, hydroxyl group or lower alkyl; and p is 0 or an integer of 1 to 5. The said lower alkyl means a C1-C6 alkyl group. Examples of (II) include styrene, α-methylstyrene, α-chlorostyrene, vinyltoluene, divinylbenzene, and the like. Moreover, this compound can also use 2 or more types together not only in 1 type.
[0018]
Examples of such alkenyl aromatic resins include styrene or its derivatives, for example, homopolymers and copolymers such as p-methylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, chlorostyrene, and bromostyrene. It is done. Further, rubber-modified high impact polystyrene (HIPS) composed of 70 to 99% by weight of the above aromatic vinyl compound and 1 to 30% by weight of diene rubber can be used. Examples of the diene rubber constituting HIPS include homopolymers of conjugated diene compounds such as butadiene, isoprene and chloroprene, copolymers of conjugated diene compounds and unsaturated nitrile compounds or aromatic vinyl compounds, and natural rubber. These can be used alone or in combination of two or more. In particular, polybutadiene and a butadiene-styrene copolymer are preferable. HIPS is obtained by a method of emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization, or a combination thereof.
[0019]
In the present invention, as a resin component, the essential polyphenylene ether resin and / or alkenyl aromatic resin only needs to have the heat resistance required for a molded product, and it is a thermoplastic resin that is used alone or in combination. It can be used in a composition.
[0020]
In the present invention, as a resin component, various properties are imparted to a thermoplastic resin composition comprising an essential polyphenylene ether-based resin and / or alkenyl aromatic-based resin, and the properties required when processed into a molded product. It is also possible to blend a reformer such as a rubber-like substance for imparting impact strength and a non-conductive filler that imparts rigidity, dimensional stability, etc. It is preferable for obtaining an excellent molded product.
[0021]
Rubber-like substances refer to natural and synthetic polymer materials that are elastic at room temperature. Particularly preferred rubbers include ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene copolymer rubber, ethylene-butene-1 copolymer rubber, polybutadiene, styrene-butadiene block copolymer rubber, styrene-butadiene copolymer rubber, Partially hydrogenated styrene-butadiene-styrene block copolymer rubber, styrene-isoprene block copolymer rubber, partially hydrogenated styrene-isoprene block copolymer rubber, polyurethane rubber, styrene graft-ethylene-propylene-nonconjugated diene copolymer rubber, styrene -Graft-ethylene-propylene copolymer rubber, styrene / acrylonitrile-graft-ethylene-propylene-nonconjugated diene copolymer rubber, styrene / acrylonitrile-graft-ethylene-propylene copolymer rubber, styrene Methyl methacrylate - graft - ethylene - propylene - non-conjugated diene copolymer rubber, styrene / methyl methacrylate - graft - ethylene - propylene copolymer rubber, or a mixture thereof. Further, a modified rubber modified with a functional monomer containing other acid or epoxy may be used.
[0022]
The amount of the rubber-like substance is preferably 0 to 50% by weight, more preferably 2 to 40% by weight in the component (A). If the rubber component is not sufficient, the impact resistance may be lowered and the molded product may become brittle, and if it is excessive, the mechanical strength may be lowered.
[0023]
As the nonconductive inorganic filler, for example, inorganic fillers such as talc, mica, glass fiber, silica alumina, calcium carbonate, clay, kaolin, magnesium sulfate, wollastonite, TiO ₂ , ZnO and Sb ₂ O ₃ are used. be able to. From the viewpoint of improving the dimensional stability after heat treatment of the molded product, it is preferably a plate-like non-conductive inorganic filler, a non-conductive inorganic filler such as talc and mica, and more preferably impact resistance by addition. It is a talc with little deterioration in properties.
[0024]
The blending amount of the nonconductive inorganic filler is preferably 0 to 15% by weight, more preferably 0 to 13% by weight in the component (A). If the non-conductive inorganic filler is not sufficient, shrinkage during processing of the molded product and dimensional stability when the molded product is heat-treated will be insufficient, and if it is excessive, the mechanical strength and impact resistance will decrease and molding will occur. The product is brittle.
[0025]
The component (B) of the present invention is a conductive carbon black that can be imparted with conductivity by blending with the component (A) and kneading, and has a bulk density of 0.15 g / ml or more and a DBP oil absorption of 175 to 205 ml. / 100 g and an average particle size of 38 to 42 nm.
[0026]
The bulk density of the component (B) that can be used in the present invention is 0.15 g / ml or more, preferably 0.17 g / ml or more. When the bulk density is 0.15 g / ml or less, it is not sufficiently dispersed when blended with the component (A) and kneaded, or the conductive carbon black or blended raw material cannot be stably supplied to the kneading apparatus. Kneadability cannot be obtained, and the conductive resin composition cannot be produced or manufactured with stable quality.
[0027]
In a conductive carbon black having a DBP oil absorption of 175 to 205 ml / 100 g and an average particle diameter of 34 to 42 nm, preferably a DBP oil absorption of 180 to 200 ml / 100 g and an average particle diameter of 36 to 40 nm and below this range, If the impact resistance is low and the electrical conductivity is insufficient, the impact resistance may be further reduced due to an increase in the amount required, etc. Conductive carbon black exceeding this range gives the necessary electrical conductivity. However, although the blending amount is small, the impact resistance is lowered and the molded product may become brittle.
[0028]
The conductive carbon black that can be used in the present invention has a sulfur content of 0.05% or less, more preferably 0.03% or less. When the sulfur content is high, a unique odor is generated and the surface of the metal is clouded. This is not preferable.
The conductive carbon black that can be used in the present invention preferably has a specific range of bulk density, DBP oil absorption, and average particle diameter, and preferably has a low sulfur content. The conductive carbon black is produced by the MMM carbon manufacturing method of Ensaco, a conductive furnace black. Carbon black of Ensaco 250G is suitable.
[0029]
The blending amount of the component (B) is an amount that provides the conductivity and antistatic properties required for the molded product of the conductive resin composition blended and kneaded with the component (A). (A) / (B) The weight ratio is 80/20 to 90/10, preferably 83/17 to 87/13. When the blending amount of the component (B) is below this range, the conductivity is insufficient, and above this range. In this case, the conductivity is improved, but the molded product is brittle and not suitable for practical use, and the kneadability is deteriorated.
[0030]
The resin composition of the present invention may contain conventional additives such as pigments, flame retardants, plasticizers, antioxidants and weathering agents in addition to the above components.
[0031]
The method for producing the resin composition of the present invention is not limited. For example, the components to be used may be blended by a known method and melt-kneaded, and the mixing means at that time can be mixed by a conventional mixing means. For this purpose, an extruder, a kneader, a roll mixer, a Banbury mixer and the like can be used.
[0032]
The resin composition of the present invention can be processed into a container for packaging an electronic component or an IC package, which is a conductive or antistatic molded product, by a known method, for example, a hard tray by injection molding, a single layer or a multilayer After processing into a conductive sheet, it can be formed into a soft carrier tape by vacuum forming or the like, but the present invention is not limited to these.
[0033]
【Example】
The present invention can be carried out by the following methods, but the present invention is not limited to these methods.
[0034]
The following compounds were used in the examples.
Ingredient (A)
PPE : polyphenylene ether resin; manufactured by PPO646 GE; intrinsic viscosity (chloroform, 25 ° C.) 0.46 dl / g
GPPS : polystyrene resin; G899 manufactured by Nippon Polystyrene Corporation;
SMEPR : rubber-like substance; styrene / methyl methacrylate-graft-ethylene-propylene-nonconjugated diene copolymer rubber produced by the production method shown in Reference Example 1
HS-T : non-conductive inorganic filler; MW HS-T Hayashi Kasei Co., Ltd. talc; average particle size (D50) 2.75 μm
Ingredient (B)
The conductive carbon black represented by the symbols CB-1 to CB-5 in Table 1 was used.
[0035]
Reference example 1
As a rubber-like substance, styrene / methyl methacrylate-graft-ethylene-propylene-nonconjugated diene copolymer rubber was produced by the following method.
In a 5 liter autoclave equipped with a stirrer, 2200 ml of pure water in which 6 g of Pluronic F68 manufactured by Asahi Denka Co., Ltd. was dissolved as a dispersant, and Esprene E502 chopped into 3 to 6 mm squares (propylene content 44 parts by weight, iodine value 8.5) 300 g of Mooney viscosity 63) at 120 ° C. was charged and suspended by stirring. Next, 9 g of t-butyl peroxypivalate and 0.18 g of P-benzoquinone were added as polymerization initiators, 101 g of styrene and 19 g of methyl methacrylate were added as monomers, and the autoclave was immediately heated to 30 ° C. in an oil bath. And start heating. The temperature was raised to 110 ° C. at a rate of about 1 ° C. per minute, and the polymerization reaction was carried out while maintaining the temperature at 110 ° C. for 30 minutes. The resulting granular graft was washed with water and vacuum dried at 95 ° C. to obtain a styrene / methyl methacrylate-graft-ethylene-propylene-nonconjugated diene copolymer rubber (SMEPR).
[0036]
After blending the components in the ratios shown in Tables 2 and 3, Table 4 was used using TEM-50A (Toshiba Machine 50 mm twin screw extruder) and IS220EN (Toshiba Machine injection clamping machine 220 ton mold clamping force). After the strand melt-kneaded and extruded under the conditions shown in Fig. 1 was cooled in a water bath and then cut with a strand cutter, pelletized and granulated, the resulting pellet was dried with hot air at 130 ° C for 3 hours, Test specimens were molded by injection molding under the conditions shown in No. 4, and various evaluations were performed. The evaluation results are shown in Tables 2 and 3.
[0037]
Evaluation was performed as follows.
Kneadability: When producing a conductive resin composition as described above, the case where it can be continuously kneaded and granulated is represented by ◯, and the case where it cannot be represented by x.
(1) Surface resistance value (hereinafter referred to as SR): Measured on a test piece having a thickness of 3.2 mm in accordance with ASTM D257. The unit is Ω.
(2) Izod impact strength (hereinafter referred to as Izod): Based on ASTM D256, a 3.2 mm thick test piece was measured with a V notch. The unit is kJ / m ² .
(3) Odor: A case where there is no odor attributed to the metal surface, such as clouding, is indicated by ○, and a case where it is present is indicated by ×.
(4) Judgment: The kneadability and odor are ◯, and the SR is low in resistance and excellent in conductivity, and the value of Izod is higher than when other conductive carbon black is blended in the molded product of the conductive resin composition. The case where the impact resistance is excellent is indicated by ○, and the case where it is not is indicated by ×.
[0038]
[Table 1]

[0039]
[Table 2]

[0040]
[Table 3]

[0041]
[Table 4]

[0042]
Examples 1-2
The conductive resin composition is granulated by melting and kneading with a TEM50 twin-screw kneader manufactured by Toshiba Machine under the ratios shown in Table 2 and the conditions shown in Table 4, and molding is performed using an IS220EN injection molding machine manufactured by Toshiba Machine using the obtained pellets. The product was processed and evaluated for kneadability, SR, Izod, and odor. The results are shown in Table 2.
[0043]
In Example 1, based on the composition of the present invention, the conductive resin composition containing the conductive carbon black having specific properties is excellent in kneadability, SR, and Izod, and does not generate a problematic odor. It shows that a preferable conductive resin composition is obtained.
[0044]
In Example 2, it is a case where the compounding quantity of electroconductive carbon black which has a specific property is reduced, and shows that the electroconductive resin composition whose required electroconductivity improved from Example 1 is obtained.
[0045]
Comparative Examples 1-5
The conductive resin composition is granulated by melting and kneading with a TEM50 twin-screw kneader manufactured by Toshiba Machine under the ratios shown in Table 3 and the conditions shown in Table 4, and molding is performed using an IS220EN injection molding machine manufactured by Toshiba Machine using the obtained pellets. The product was processed and evaluated for kneadability, SR, Izod, and odor. The results are shown in Table 3.
[0046]
The comparative example which is not based on the composition of this invention is shown.
In Comparative Examples 1 and 2, the conductive resin composition blended with the conductive furnace black that is the same as the example but does not have specific properties is excellent in kneadability but inferior in SR and Izod. The product is obtained, and there is the generation of a problematic odor, which is not preferable.
[0047]
Comparative Examples 3 and 4 are conductive resin compositions containing ketjen black which is different from the Examples and does not have specific properties. In Comparative Example 3, the conductivity is efficiently given to the blending amount. However, in Comparative Example 4 in which SR and Izod were inferior and the blending amount was increased in order to improve SR, kneadability deteriorated and granulation could not be performed and pellets were not obtained.
[0048]
Comparative Example 5 is a conductive resin composition blended with acetylene black that does not have specific properties different from those of the Examples, and is a preferable conductive resin composition that is excellent in kneadability and does not generate problematic odors. Although obtained, SR and Izod are inferior.
[0049]
【The invention's effect】
According to the present invention, a thermoplastic resin composition comprising a polyphenylene ether resin and / or an alkenyl aromatic resin is used as an essential resin component, and conductive carbon black having other properties can be added by blending conductive carbon black having specific properties. Conductive resin composition with better electrical conductivity and impact resistance than when blended with conductive carbon black is obtained. Furthermore, with conductive carbon black having specific properties, the required conductivity is Conductive resin composition capable of providing a molded product with further improved impact resistance by reducing the blending amount, thereby reducing the impact resistance drop caused by the blending of conductive carbon black. You can get things.
[0050]
As shown in the comparative example, when the component (B) is not conductive carbon black having a specific property, it was carried out on SR and Izod of a molded product of a conductive resin composition obtained by blending and kneading. As is apparent from the examples, it can be seen that the SR and Izod of the molded product of the conductive resin composition obtained by blending and kneading conductive carbon black having specific properties are more excellent. The conductive resin composition of the present invention can be formed into a molded product having excellent conductivity and impact resistance, and can be used after being molded into a container for packaging electronic components and IC packages.

Claims (4)

A conductive resin composition comprising the following components (A) and (B), wherein the weight ratio of (A) / (B) is from 80/20 to 90/10.
(A): Thermoplastic resin composition containing polyphenylene ether resin (B): Conductive carbon black has a bulk density of 0.15 g / ml or more, DBP oil absorption of 175 to 205 ml / 100 g, and average particle diameter of 34 to 42 nm conductive carbon black click is 2. The conductive resin composition according to claim 1, wherein the component (B) is conductive furnace black. The conductive resin composition according to claim 1 or 2, wherein the component (A) contains an alkenyl aromatic resin. Antistatic claim 1 which is a surface resistance value which is obtained by molding the resin composition is less 10 ⁶ Omega is conductive or surface resistance 10 ⁶ to 10 ¹¹ Omega according to one of claims of 3 A container for packaging electronic components or IC packages.