JP2004323738A

JP2004323738A - Resin composition intermediate, resin composition and carbon nanotube filler, and manufacturing methods for them

Info

Publication number: JP2004323738A
Application number: JP2003122088A
Authority: JP
Inventors: Takashi Kiyono; 俊清野; Yasuaki Kai; 康朗甲斐
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 2003-04-25
Filing date: 2003-04-25
Publication date: 2004-11-18

Abstract

<P>PROBLEM TO BE SOLVED: To enhance various characteristics of a polycarbonate resin composition such as strength, stiffness, heat distortion temperature and thermal expansion coefficient, etc. <P>SOLUTION: A carboxyl group is formed on the surface of a carbon nanotube by treating the nanotube with an acid or hydrogen peroxide. In the next step, the carboxyl group of the nanotube is treated with a chlorinated acyl group to form a chlorinated acyl group on the surface of the nanotube. In the next step, through a dechlorination reaction between the chlorinated acyl group of the nanotube and a hydroxyl group of a 2,2-bis (4-hydroxy phenyl) propane, the nanotube and the 2,2-bis (4-hydroxy phenyl) propane are chemically bonded, with an intervening ester linkage, to form a resin composition intermediate. In the next step, a polycondensation reaction of the resin composition intermediate by a phosgene method produces the resin composition chemically bonded between the carbon nanotube and the polycarbonate with the intervening ester linkage. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、ポリカーボネート樹脂の強度および弾性率向上、表面硬度向上、熱変形温度向上、熱膨張率低減、熱伝導率向上、電気抵抗の低減を実現しうるカーボンナノチューブ分散配合のポリカーボネート樹脂組成物およびその製造方法に関する。製造された樹脂は、自動車用の外板や内装部品などに利用される。
【０００２】
【従来の技術】
自動車の外板や内装部品は、デザイン上重要な部品で、各種樹脂材の出現により形状自由度が大きくなり、使用面積は増加している。このため、軽量化と安全性とが要求されている。樹脂複合材は、鋼板、アルミ板に比べ、弾性率が小さいので、外板部品には適用が困難であった。これに対して、補強材としてガラス繊維を添加して剛性を向上させる試みがなされている。しかしながら、前記ガラス繊維の繊維径が約１０ミクロンもあり、長さも約２００ミクロンもあるので表面平滑性が悪くなり、塗装後の美観が不十分となる。
【０００３】
また、ガラス繊維複合樹脂は、表面硬度が小さいので、傷がつき安く、外板や外装部品には適用が困難であった。これに対して、焼付け塗装をしている例があるが、耐熱性不足の為、十分に焼き付け温度が上げられず、表面硬度不足で長時間使用では傷が付くので使用されなかった。
【０００４】
最近、分子レベルの複合材料による樹脂特性の改良が注目されるようになった。代表的なものとして、豊田中研他の「ポリアミド複合材料及びその製造方法（特公平７−４７６４４号）」が挙げられる。
【０００５】
前記公報には、無機充填材としてモンモリナイトを使用し、モンモリナイトの層間にナイロンの原料カプロラクタムを含浸させて重合させ、ナイロンポリマーと充填材との複合樹脂組成物を得る方法が開示されている。この方法によれば、得られた樹脂組成物の物性向上を実現させることはできるが、吸湿性の点や、表面硬度の点で使用可能な部品を制限してしまう。
【０００６】
その他の技術としては、クラレの「樹脂組成物、その製法および積層体（特開平５−８６２４１号）」がある。この技術は、粘土にＥＶＡを含浸し、ポリアミドと溶融混連しＰＰと積層フィルムを得る方法である。
【０００７】
また、東ソーの「ポリアリーレン複合材料およびその製造方法（特開平５−１９４８５１号）」には、層状ケイ酸塩を含むポリアーレンスルフィド複合材料の製法が開示されている。また、三菱化成の「ポリアミド樹脂組成物およびその製造方法（特開平５−３０６３７０号）」には、層状リン酸塩誘導体とポリアミドモノマーとを加熱重合してポリアミド樹脂組成物を得る方法が開示されている。
【０００８】
さらに、カルプ工業の「複合材料その製造方法および該複合材料を含有する樹脂成形材料（特開平６−４１３４６号）」には、モンモリロナイトとビニル系高分子化合物とからなる複合材料を製造する方法が開示されている。
【０００９】
また、ユニチカの「強化ポリアミド樹脂組成物およびその製造方法（特開平６−２４８１７６号）」では、フッ素雲母とポリアミドモノマーを加熱重合して得られるポリアミド樹脂複合材料の製法を開示している。
【００１０】
さらに、東洋紡の「熱可塑性ポリエステル組成物、その製造方法およびその成形品（特開平７−２６１２３号）」は、粘土とポリエステル樹脂との複合材の製法を開示している。
【００１１】
これらはすべて粘土やタルク等の無機充填材の層状物質に高分子化合物を層間にインターカレートしたものである。これらのナノコンポジトもまた強度特性向上はあるが吸湿性の点や、表面硬度不足の点で使用可能な部品に制限がある。
【００１２】
また、三菱化学の「芳香族ポリカーボネート樹脂組成物」（特開平７−２０７１３４号，特開平７−２２８７６４号），および「熱可塑性樹脂組成物」（特開平７−３３１０９２号）では、ポリカーボネートと層状ケイ酸塩との溶融混合による製法の為、層状ケイ酸塩の均一分散が不足し、要求特性の高い樹脂製部品には使用できない。
【００１３】
さらに、三菱化学の「芳香族ポリカーボネート樹脂組成物および光通信用部品」（特開平８−７３７２３号）では、ポリカーボネートのエステル交換反応による合成過程で、ジフェニルカーボネート（炭酸ジフェニル）に希土類元素（エルビウム、プラセオジウム、ネオジウム）の酢酸塩を配合し、ポリカーボネートに金属元素を混合している。この場合、これらは、ポリカーボネイト単独に比べて、屈折率が１．５８から１．６１に増加しているが、光透過率（最小値）は７７〜７６の値で変化がないので、光通信には有効であるが、強度、弾性率あるいは表面硬度および耐熱性の向上が見られず、要求特性の高い自動車用の樹脂部品には使用できない。
【００１４】
また、タキロン（株）の論文「二軸押出機によるポリマー中のカーボンナノチューブの分散」（成形加工第１４巻第２号２００２）では、ポリカーボネートに表面未処理のカーボンナノチューブを二軸押出機で溶融混合し、分散性を評価した例はあるが、表面処理による組成物の特性向上の検討は成されていない。
【００１５】
さらに、東レの「カーボン含有樹脂組成物、成形材料および成形体」（特開２００３−１２９３９号）では、カーボンナノチューブと樹脂と充填剤を溶融混合したもので、１．８ｗｔ％以上では、分散性が悪く、成形性および機械的特性などが向上せず、実用には適さない。
【００１６】
また、「樹脂ウインドウおよびその製法（特開平１１−３４３３４９号）」では、アクリル樹脂の合成過程で、シリカ微粒子を配合することがあるが、得られた樹脂組成物は、アクリル樹脂が母材であるため、耐熱性、耐衝撃性が不足し、実用には至らない。さらに、この特許の実施例にポリカーボネート樹脂を塩化メチレン溶剤に溶解し、これにシリカ微粒子を混合する方法が開示されているが、シリカ濃度が大きくなると混合分散が困難になり、強度、弾性率、耐衝撃性などが不足し、実用には至らない。
【００１７】
【発明が解決しようとする課題】
従来の製造法で得られた、ポリカーボネート樹脂を使用した樹脂組成物は、強度、剛性が鋼板、アルミ板に比べ小さく、大きな外板に使用するには、厚さを増すことが必要となり、軽量化の効果が少なくなる。
【００１８】
また、ポリカーボネート樹脂組成物は表面に傷が付き易いため、塗装を行っていたが、通常の塗装では表面硬度不足で、長時間使用では傷が付きやすい。このため高温焼付け塗装が必要であるが、従来のポリカーボネート樹脂組成物は十分高い熱変形温度を有しないという問題がある。
【００１９】
さらに、ポリカーボネート樹脂組成物は鋼板やアルミ板に比べ、熱膨張率が大きく、車の外板、内装部品は寸法が大きく、夏になるとポリカーボネート樹脂系複合材の熱膨張で、表面が波打ちをおこして表面平滑性が不十分となり使用することができなかった。
【００２０】
本発明は、ポリカーボネート樹脂組成物の、強度、剛性、熱変形温度、熱膨脹率などの諸特性を向上させることを目的とする。
【００２１】
【課題を解決するための手段】
上記目的を達成すべく、本発明は、
カーボンナノチューブと、
前記カーボンナノチューブの表面にエステル結合を介して化学的に結合した２，２−ビス（４−ヒドロキシフェニル）プロパンと、を具えることを特徴とする、樹脂組成物中間体に関する。
【００２２】
また、本発明は、
カーボンナノチューブと、
前記カーボンナノチューブの表面にエステル結合を介して化学的に結合したポリカーボネートと、を具えることを特徴とする、樹脂組成物に関する。
【００２３】
さらに、本発明は、
カーボンナノチューブと、
前記カーボンナノチューブの表面において化学的に結合されたカルボキシル基と、を具えることを特徴とする、カーボンナノチューブ充填材に関する。
【００２４】
また、本発明は、
カーボンナノチューブと、
前記カーボンナノチューブの表面において化学的に結合された塩素化アシル基と、を具えることを特徴とする、カーボンナノチューブ充填材に関する。
【００２５】
本発明者らは上記目的を達成すべく鋭意検討を実施した。ポリカーボネート樹脂組成物の強度、剛性などの諸特性を向上させるためには、前記樹脂組成物を構成しているポリカーボネートの分子構造に種々の変更を加えることが考えられるが、分子構造のみでは特性向上に限界がある。そこで、本発明者らは、前記樹脂組成物に含有させることによって特性向上を実現することのできる充填材の探索を実施し、その結果、カーボンナノチューブに着目するに至った。
【００２６】
しかしながら、カーボンナノチューブを従来のような混練法を用いてポリカーボネート樹脂に配合しようとすると、前記カーボンナノチューブは混練中に凝集してしまい、前記カーボンナノチューブを配合することによる特性を十分に得ることができなかった。そこで、本発明者らは、前記カーボンナノチューブのポリカーボネート樹脂中への配合方法について種々検討を実施した。
【００２７】
その結果、以下に詳細に示す製造方法に基づいて、カーボンナノチューブの表面にカルボキシル基を形成し、その後、このカルボキシル基を塩素化アシル基に転換したカーボンナノチューブ充填材を準備し、次いで、この充填材に２，２−ビス（４−ヒドロキシフェニル）プロパン（以下、「ビスフェノールＡ」という）をエステル結合させた樹脂組成物中間体を得、次いで、前記樹脂組成物中間体にホスゲン法に基づいて重縮合反応を施して樹脂組成物を形成することにより、前記樹脂組成物は、前記カーボンナノチューブに対してエステル結合を介してポリカーボネートが化学的に結合した構成を呈することを見出した。
【００２８】
したがって、最終的に得た前記樹脂組成物は、前記カーボンナノチューブを核としてポリカーボネートが化学的に結合した構成を呈するので、前記カーボンナノチューブは必然的に前記樹脂組成物中で均一に分散するようになるとともに、前記カーボンナノチューブは前記ポリカーボネート樹脂と強固に結合するようになる。したがって、前記樹脂組成物の強度、剛性、熱変形温度、熱膨脹率などの諸特性は、充填材としてのカーボンナノチューブ配合の効果と相伴って向上するようになる。結果として、車両用の外装部品及び外板部品などの諸用途に使用できるようになる。
【００２９】
本発明の詳細及びその他の特徴、並びに樹脂塑性物の製造方法及び成形体、部品、さらにこれらの製造方法については以下の発明の実施の形態で説明する。
【００３０】
【発明の実施の形態】
（樹脂組成物中間体及びカーボンナノチューブ充填材）
本発明の、最終生成物である樹脂組成物を得るためには、最初に所定のカーボンナノチューブ充填材を準備する。前記カーボンナノチューブ充填材は以下のようにして作製する。
【００３１】
最初に、所定のカーボンナノチューブに対して酸処理又は過酸化水素処理を施し、前記カーボンナノチューブ表面に化学的に結合したカルボキシル基を形成する。前記酸処理及び前記過酸化水素処理は好ましくは酸性溶液中で行う。これによって、カーボンナノチューブの凝集を抑制した状態でカルボキシル基の形成を簡易に行うことができるようになる。
【００３２】
また、前記酸性溶液に対して超音波を印加することにより、前記カーボンナノチューブを前記酸性溶液中への分散効果を高めることができ、カーボンナノチューブの凝集をより効果的に抑制することができるようになる。
【００３３】
次いで、前記カーボンナノチューブに対して塩素化アシル基処理を施し、前記カルボキシル基を塩素化アシル基に転換する。前記塩素化アシル基処理は、前記カーボンナノチューブをＮ，Ｎ−ジメチルホルムアミド（ＤＭＦ）などの有機溶媒中に分散させ、この溶媒中に所定の塩素化アシル化合物を加えることによって実施することが好ましい。
【００３４】
なお、前記塩素化アシル基処理は、前記塩素化アシル化合物として塩化チオニルを用いることによって簡易に実行することができる。
【００３５】
カーボンナノチューブ表面の酸処理による、カルボキシル基の導入および塩化チオニルによる塩素化アシル基の導入方法についての説明は、Ｙ．Ｓｕｍ，Ｗ．Ｈｕａｎｇらの論文（Ｃｈｅｍ．Ｍａｔｅｒ．２００１，１３，２８６４−２８６９９）などに述べられている。ここで、本発明に関係することを、参考文献にもとづき説明する。
【００３６】
カーボンナノチューブを強酸（濃塩酸、濃硝酸、濃硫酸、混酸、及び王水）の原液に入れ、加熱還流あるいは超音波処理をすることで、カーボンナノチューブの末端面および側面にカルボキシル基を付加することが可能である。次いで、Ｎ，Ｎ−ジメチルホルムアミド（ＤＭＦ）などの有機溶媒中で前記カーボンナノチューブに対して塩化チオニルを作用させると、前記カルボキシル基を塩素化アシル基に変化させることが可能となる。なお、このときの反応式を以下に示す。
ＣＮＴ−ＣＯＯＨ＋ＳＯＣｌ_２→ＣＮＴ−ＣＯＣｌ＋ＨＣｌ↑＋ＳＯ_２↑（ＣＮＴ：カーボンナノチューブ）
【００３７】
上述のようにしてカーボンナノチューブ充填材を作製した後、塩素化炭化水素などの有機溶媒中に、前記カーボンナノチューブ充填材を分散混合させるとともにビスフェノールＡを配合させ、脱塩酸反応を行う。この結果、前記ビスフェノールＡは前記カーボンナノチューブの表面にエステル結合を介して化学的に結合するようになり、本発明の樹脂組成物中間体が得られるようになる。
【００３８】
前記塩素化炭化水素としては、メチレンクロライド、１，２−ジクロロエタン，クロロホルム、及びクロロベンゼンを例示することができる。
【００３９】
また、前記脱塩酸反応は、有機塩基触媒のピリジン、トリエチルアミン、及びジメチルアニリンなどを用いて行うことができ、特に、ピリジンを用いることが好ましい。
【００４０】
前記カーボンナノチューブ充填材から前記樹脂組成物中間体を得る際の反応式を図１に示す。
【００４１】
なお、上述した樹脂組成物中間体は、樹脂組成物を作製する際の重縮合反応工程の一部として行うこともできる。
【００４２】
また、前記樹脂組成物中間体におけるエステル結合は、赤外吸収スペクトルにより、確認できる。具体的には、塩素化アシル基及びビスフェノールＡの水酸基の赤外吸収スペクトルが減少して、エステル結合の赤外吸収スペクトルが増加することから判断できる。
【００４３】
前記樹脂組成物中間体において、カーボンナノチューブは単層又は多層として存在する。また、その形態は、アスペクト比が２０〜２００００であり、太さが１ｎｍ〜５０ｎｍであり、長さが１μｍ〜２０μｍの繊維状連続体となる。
【００４４】
なお、前記カーボンナノチューブ充填材を作製する際において、前記カーボンナノチューブの表面にカルボキシル基を形成する際に使用する酸性溶液の濃度及び超音波の印加時間を適宜に制御することにより、前記カーボンナノチューブの長さを可視光波長領域以下の３８０ｎｍ以下、さらには２００ｎｍ以下とすることができる。これによって、最終的に得る樹脂組成物の透明性を十分に確保できるようになる。
【００４５】
具体的には、前記酸性溶液の濃度を濃くすることにより、また超音波印加時間を長くすることにより、前記カーボンナノチューブの長さを低減することができる。
【００４６】
（樹脂組成物）
上述のようにして樹脂組成物中間体を作製した後、この樹脂組成物中間体に対してホスゲン法による重縮合反応を施し、目的とする樹脂組成物を作製する。具体的には、前記塩素化炭化水素などの有機溶媒中で、前記樹脂組成物中間体を形成すると同時又は形成した後にホスゲンを配合することによって、前記有機塩基触媒を利用した重縮合反応を実施する。このときの反応式を図２に示すとともに、前記樹脂組成物の構造の概要を図３に示す。
【００４７】
図３から明らかなように、前記樹脂組成物においては、カーボンナノチューブを核とし、その周囲に芳香族ポリカーボネートが分子鎖を広げるような形態で化学的に結合していることが分かる。したがって、前記樹脂組成物中において、前記カーボンナノチューブは均一に分散するとともに、前記芳香族ポリカーボネートと強固に結合していることが分かる。結果として、充填材としてのカーボンナノチューブ配合の効果と相伴って、前記樹脂組成物の強度、剛性、熱変形温度、熱膨脹率などの諸特性は向上するようになる。
【００４８】
上述した樹脂組成物は前記樹脂組成物中間体から得られるものであるので、その内部に存在するカーボンナノチューブの形態は、前記中間体と同様に、単層又は多層であって、アスペクト比が２０〜２００００であり、太さが１ｎｍ〜５０ｎｍであり、長さが１μｍ〜２０μｍの繊維状連続体である。したがって、前記樹脂組成物に対する充填材として高い補強効果及び線膨脹率低減効果を呈するようになる。
【００４９】
また、上述した樹脂組成物中間体におけるカーボンナノチューブの長さが３８０ｎｍ以下、さらには２００ｎｍ以下となる場合は、前記樹脂組成物の透明性を確保できるようになる。
【００５０】
さらに、前記樹脂組成物中におけるカーボンナノチューブに配合量は、０．１重量％から５０重量％であることが好ましい。
【００５１】
なお、ポリカーボネートを得る方法として上述したホスゲン法の他に、エステル交換法がある。しかしながら、この方法では一般に高分子量のポリカーボネートを得ることができず、強度及び弾性率などが低いために、自動車部品などの要求仕様を満足することができない。
【００５２】
（樹脂組成物の用途）
上述のようにして得た樹脂組成物は、目的とする成形品の大きさ及び曲率等に応じて、溶融押出成形、射出成形、及びブロー成形などの成形処理を施し、目的とする成形品を得ることが可能である。この成形品は、強度、剛性、熱変形温度、熱膨脹率などの諸特性に優れるため、車両用の外装部品あるいは外板部品に適用することができる。
【００５３】
具体的には、図４に示すように、外装部品として、バンパー及びサイドモールを例示することができ、外板部品として、フロントフェンダー、ドアアウター、リアへンダー、フード、バックドアアウター、及びルーフなどを例示することができる。また、スモーク入りで光線透過性の有る部品としては、テールランプカバーなどを例示することができる。
【００５４】
【実施例】
（実施例１）
最初に、メチレンクロライド２５０ミリリットルに、ビスフェノールＡ２２８ｇを溶解した。次いで、得られた溶液中に、市販品のカーボンナノチューブ（単層：ＣＮＩ（ＣａｒｂｏｎＮａｎｏｔｅｃｈｎｏｌｏｇｉｅｓ，Ｉｎｃ．）社製、商品名（ＢＵＣＫＹＴＵＢＥＳ））を予め塩素化アシル基で表面処理して得たカーボンナノチューブを１３ｇ配合分散したメチレンクロライド溶液７５０ｍｌを加え、次いで、脱塩酸反応の触媒としてピリジン溶液１５ｍｌを配合して約１時間攪拌し、カーボンナノチューブ表面の塩素化アシル基にビスフェノールＡを共有結合させ、樹脂組成物中間体を得た。
【００５５】
次いで、前記樹脂組成物中間体を含む溶液中に、ホスゲンを２ｇ／ｍｉｎの速度で約５０分間かけて吹き込みながら攪拌した。次いで、脱塩酸反応触媒として１％トリエチルアミンのメチレンクロライド溶液１５ｍｌを加え、約１時間、攪拌することにより、ビスフェノールＡとホスゲンを縮重合し、カーボンナノチューブが共有結合したポリカーボネートの溶液を得た。
【００５６】
次いで、得られた重合液をリン酸で中和、水洗し、メタノールに滴下して重合組成物を沈殿させた後、濾過、乾燥して、樹脂組成物の粉末を得た。得られた樹脂組成物粉末中のカーボンナノチューブの含有量は約５重量％であった。
【００５７】
次いで、前記樹脂組成物粉末を、乾燥、粉砕し、熱プレス成形により、シート状の成形品を得た。得られたシート状の成形品は、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、強度、弾性率の向上と熱膨脹率の低下が見られた。また、前記シート状成形品中には、カーボンナノチューブが均一に分散していることが判明した。結果を表１に示す。
【００５８】
（実施例２）
単層のカーボンナノチューブに代えて、多層のカーボンナノチューブ（Ｔｓｉｎｇｈｕａ−ＮａｆｉｎｅＮａｎｏ−ＰｏｗｄｅｒＣｏｍｍｅｒｃｉａｌｉｚａｔｉｏｎＥｎｇｉｎｅｅｒｉｎｇＣｅｎｔｅｒ製、品番タイプ（ＴｓＮａ−ＭＷＣｎｔ２））を用いた以外は、実施例１と同様にして樹脂組成物中間体を作製し、樹脂組成物粉末を作製した。この樹脂組成物粉末を、乾燥、粉砕し、熱プレス成形により、シート状の成形品を得た。得られたシート状成形品は、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、強度、弾性率の向上と熱膨脹率の低下が見られた。また、前記シート状成形品中には、カーボンナノチューブが均一に分散していることが判明した。結果を表１に示す。
【００５９】
（実施例３）
カーボンナノチューブの配合量を約５重量％から約３．５重量％に変化させた以外は、実施例１と同様にして樹脂組成物中間体を作製し、樹脂組成物粉末を作製した。なお、前記樹脂組成物粉末中におけるカーボンナノチューブの配合量は約３．５重量％であった。前記樹脂組成物粉末を、乾燥、粉砕し、熱プレス成形により、シート状の成形品を得た。得られたシート状の成形品は、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、強度、弾性率の向上と熱膨脹率の低下が見られた。また、前記シート状成形品中には、カーボンナノチューブが均一に分散していることが判明した。結果を表１に示す。
【００６０】
（実施例４）
単層のカーボンナノチューブに代えて、多層のカーボンナノチューブ（Ｔｓｉｎｇｈｕａ−ＮａｆｉｎｅＮａｎｏ−ＰｏｗｄｅｒＣｏｍｍｅｒｃｉａｌｉｚａｔｉｏｎＥｎｇｉｎｅｅｒｉｎｇＣｅｎｔｅｒ製、品番タイプ（ＴｓＮａ−ＭＷＣｎｔ２））を用いた以外は、実施例１と同様にして樹脂組成物中間体を作製し、樹脂組成物粉末を作製した。この樹脂組成物粉末を、乾燥、粉砕し、熱プレス成形により、シート状の成形品を得た。得られたシート状の成形品は、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、強度、弾性率の向上と熱膨脹率の僅かな低下が見られた。また、前記シート状成形品中には、カーボンナノチューブが均一に分散していることが判明した。結果を表１に示す。強度、弾性率の向上と熱膨脹率の低下が見られた。結果を表１に示す。
【００６１】
（実施例５）
最初に、メチレンクロライド２５０ミリリットルに、ビスフェノールＡ２６ｇを溶解した。次いで、得られた溶液中に、市販品のカーボンナノチューブ（単層）（単層：ＣＮＩ（ＣａｒｂｏｎＮａｎｏｔｅｃｈｎｏｌｏｇｉｅｓ，Ｉｎｃ．）社製、商品名（ＢＵＣＫＹＴＵＢＥＳ））を予め塩素化アシル基で表面処理をしたカーボンナノチューブを１３ｇ配合分散したメチレンクロライド７５０ｍｌを加え、次いで、脱塩酸反応の触媒としてピリジン溶液１５ｍｌを配合して約１時間攪拌し、カーボンナノチューブ表面の塩素化アシル基にビスフェノールＡを共有結合させ、樹脂組成物中間体を得た。
【００６２】
次いで、前記樹脂組成物中間体を含む溶液をリン酸で中和、水洗し、メタノールに滴下して、重合組成物を沈殿させ、濾過及び乾燥して、樹脂組成物中間体の粉末を得た。
【００６３】
次いで、ポリカーボネイト樹脂（ユーピロンＳ２０００三菱エンプラ製）２０２ｇを、メチレンクロライド溶液４５６ｇに溶解し、得られた溶液中に上記樹脂組成物中間体を含む溶液を配合して前記樹脂組成物中間体を分散させ、ポリカーボネイト樹脂／カーボンナノチューブ混合溶液を調整した。この混合溶液をメタノールに滴下し樹脂組成物を沈殿させ、濾過し、乾燥して、粉末を得た。
【００６４】
次いで、前記樹脂組成物粉末を、乾燥、粉砕し、熱プレス成形により、シート状の成形品を得た。得られたシート状の成形品は、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、強度、弾性率の向上と熱膨脹率の低下が見られた。また、前記シート状成形品中には、カーボンナノチューブが均一に分散していることが判明した。結果を表１に示す。
【００６５】
（実施例６）
単層のカーボンナノチューブに代えて、多層のカーボンナノチューブ（Ｔｓｉｎｇｈｕａ−ＮａｆｉｎｅＮａｎｏ−ＰｏｗｄｅｒＣｏｍｍｅｒｃｉａｌｉｚａｔｉｏｎＥｎｇｉｎｅｅｒｉｎｇＣｅｎｔｅｒ製、品番タイプ（ＴｓＮａ−ＭＷＣｎｔ２））を用いた以外は、実施例５と同様にして樹脂組成物中間体を作製し、樹脂組成物粉末を作製した。この樹脂組成物粉末を、乾燥、粉砕し、熱プレス成形により、シート状の成形品を得た。得られたシート状の成形品は、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、強度、弾性率の向上と熱膨脹率の低下が見られた。また、前記シート状成形品中には、カーボンナノチューブが均一に分散していることが判明した。結果を表１に示す。
【００６６】
（実施例７）
実施例１と同様にして樹脂組成物中間体を作製した後、ポリカーボネート樹脂（ユーピロンＳ２０００三菱エンプラ製）２０２ｇを小型ニーダーで溶融し、この溶融物中に上記樹脂組成物中間体を含む溶液を配合するとともに、前記樹脂組成物中間体を分散させることによって、ポリカーボネート樹脂／カーボンナノチューブ組成物を得た。次いで、この樹脂組成物を粉砕して、粉末状とした。次いで、得られた樹脂組成物粉末を乾燥、粉砕し、熱プレス成形により、シート状の成形品を得た。得られたシート状の成形品は、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、強度、弾性率の向上と熱膨脹率の低下が見られた。また、前記シート状成形品中には、カーボンナノチューブが均一に分散していることが判明した。結果を表１に示す。
【００６７】
（実施例８）
単層のカーボンナノチューブに代えて、多層のカーボンナノチューブ（Ｔｓｉｎｇｈｕａ−ＮａｆｉｎｅＮａｎｏ−ＰｏｗｄｅｒＣｏｍｍｅｒｃｉａｌｉｚａｔｉｏｎＥｎｇｉｎｅｅｒｉｎｇＣｅｎｔｅｒ製、品番タイプ（ＴｓＮａ−ＭＷＣｎｔ２））を用いた以外は、実施例７と同様にして樹脂組成物中間体を作製し、樹脂組成物粉末を作製した。この樹脂組成物粉末を、乾燥、粉砕し、熱プレス成形により、シート状の成形品を得た。得られたシート状の成形品は、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、強度、弾性率の向上と熱膨脹率の低下が見られた。また、前記シート状成形品中には、カーボンナノチューブが均一に分散していることが判明した。結果を表１に示す。
【００６８】
【表１】

【００６９】
（比較例１）
市販品のカーボンナノチューブ（単層：ＣＮＩ（ＣａｒｂｏｎＮａｎｏｔｅｃｈｎｏｌｏｇｉｅｓ，Ｉｎｃ．）社製、商品名（ＢＵＣＫＹＴＵＢＥＳ））１３ｇとポリカーボネイト樹脂（ユーピロンＳ２０００三菱エンプラ製）２２８ｇとを小型ニーダーで溶融混合し、得られた樹脂組成物を、粉砕し、熱プレス成形により、シート状の成形品を得た。得られた、シート状の成形品は、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、僅かに強度向上があり、弾性率の向上が僅かに見られ、また熱膨脹率の低下が僅かに見られた。
但し、上述した実施例と比較して十分なものではなかった。また、カーボンナノチューブはシート状成形品中で凝集する傾向があった。
【００７０】
（比較例２）
単層のカーボンナノチューブに代えて、多層のカーボンナノチューブ（Ｔｓｉｎｇｈｕａ−ＮａｆｉｎｅＮａｎｏ−ＰｏｗｄｅｒＣｏｍｍｅｒｃｉａｌｉｚａｔｉｏｎＥｎｇｉｎｅｅｒｉｎｇＣｅｎｔｅｒ製、品番タイプ（ＴｓＮａ−ＭＷＣｎｔ２））を用いた以外は、比較例１と同様にして樹脂組成物を得、シート状成形品を得た。このシート状成形品においては、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、僅かに強度向上があり、弾性率の向上が僅かに見られ、また熱膨脹率の低下が僅かに見られた。但し、上述した実施例と比較して十分なものではなかった。また、カーボンナノチューブはシート状成形品中で凝集する傾向があった。結果を表２に示す。
【００７１】
（比較例３）
カーボンナノチューブの配合量を１３ｇから８．５ｇに代えた以外は、比較例１と同様にして樹脂組成物を得、シート状成形品を得た。このシート状成形品においては、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、僅かに強度向上があり、弾性率の向上が僅かに見られ、また熱膨脹率の低下が僅かに見られた。但し、上述した実施例と比較して十分なものではなかった。また、カーボンナノチューブはシート状成形品中で凝集する傾向があった。結果を表２に示す。
【００７２】
（比較例４）
単層のカーボンナノチューブに代えて、多層のカーボンナノチューブ（Ｔｓｉｎｇｈｕａ−ＮａｆｉｎｅＮａｎｏ−ＰｏｗｄｅｒＣｏｍｍｅｒｃｉａｌｉｚａｔｉｏｎＥｎｇｉｎｅｅｒｉｎｇＣｅｎｔｅｒ製、品番タイプ（ＴｓＮａ−ＭＷＣｎｔ２））を用いた以外は、比較例３と同様にして樹脂組成物を得、シート状成形品を得た。このシート状成形品においては、参考例で示したポリカーボネート樹脂単体（ユーピロンＳ２０００、三菱エンプラ製）の場合に比べて、僅かに強度向上があり、弾性率の向上が僅かに見られ、また熱膨脹率の低下が僅かに見られた。但し、上述した実施例と比較して十分なものではなかった。また、カーボンナノチューブはシート状成形品中で凝集する傾向があった。結果を表２に示す。
【００７３】
【表２】

【００７４】
以上、本発明を発明の実施の形態に即して詳細に説明してきたが、本発明は上記の内容に限定されるものではなく、本発明の範疇を逸脱しない限りにおいてあらゆる変形や変更が可能である。
【００７５】
【発明の効果】
本発明によれば、優れた力学的特性（特に曲げ強度、曲げ弾性率、線膨脹率）と成形性（成形時の流れ性など）を有し、必要に応じ優れた導電性とを有する樹脂組成物、成形材料を提供することができる。このような樹脂組成物、成形材料を用いて車両用の外板、外装部品を成形すれば、軽量で、優れた力学的特性、外観品質、導電性を有するため、静電塗装が良好な部品が得られる。
【図面の簡単な説明】
【図１】カーボンナノチューブ充填材から樹脂組成物中間体を得る際の反応式である。
【図２】樹脂組成物中間体から樹脂組成物を得る際の反応式である。
【図３】樹脂組成物の構造を概略的に示す図である。
【図４】車両用外装部品及び外板部品の位置を解説したワゴン系自動車のリアサイドからの外観斜視図である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a polycarbonate resin composition containing a carbon nanotube dispersion capable of improving strength and elastic modulus of a polycarbonate resin, improving surface hardness, improving heat deformation temperature, reducing thermal expansion coefficient, improving thermal conductivity, and reducing electric resistance. It relates to the manufacturing method. The produced resin is used for outer panels and interior parts for automobiles.
[0002]
[Prior art]
2. Description of the Related Art Outer panels and interior parts of automobiles are important parts in terms of design. With the advent of various resin materials, the degree of freedom in shape has been increased, and the area used has been increasing. For this reason, weight reduction and safety are required. Since the resin composite has a smaller elastic modulus than the steel plate and the aluminum plate, it has been difficult to apply the resin composite to outer plate parts. On the other hand, attempts have been made to improve rigidity by adding glass fiber as a reinforcing material. However, since the glass fiber has a fiber diameter of about 10 microns and a length of about 200 microns, the surface smoothness is deteriorated and the appearance after painting becomes insufficient.
[0003]
Further, since the glass fiber composite resin has a small surface hardness, it is easily scratched and cheap, and it has been difficult to apply it to an outer plate or an exterior part. On the other hand, there is an example in which baking is applied. However, the baking temperature cannot be sufficiently increased due to insufficient heat resistance, and the surface hardness is insufficient, so that it is not used because it is scratched over a long period of use.
[0004]
Recently, attention has been focused on the improvement of resin properties by molecular-level composite materials. As a typical example, "Polyamide composite material and its production method (Japanese Patent Publication No. 7-47644)" by Toyoda Chuken et al.
[0005]
The publication discloses a method of obtaining a composite resin composition of a nylon polymer and a filler, using montmorillonite as an inorganic filler, impregnating and polymerizing a raw material of nylon, caprolactam, between layers of the montmorillonite. According to this method, it is possible to improve the physical properties of the obtained resin composition, but it limits parts that can be used in terms of hygroscopicity and surface hardness.
[0006]
As another technique, there is Kuraray's "Resin Composition, Production Method and Laminate (JP-A-5-86241)". In this technique, clay is impregnated with EVA, melt-mixed with polyamide, and a PP and a laminated film are obtained.
[0007]
Further, Tosoh's "Polyarylene Composite Material and Method for Producing the Same (Japanese Patent Application Laid-Open No. 5-194851)" discloses a method for producing a polyarylene sulfide composite material containing a layered silicate. Further, "Polyamide resin composition and method for producing the same" (JP-A-5-306370) by Mitsubishi Chemical discloses a method of obtaining a polyamide resin composition by heat-polymerizing a layered phosphate derivative and a polyamide monomer. ing.
[0008]
Further, the method for producing a composite material composed of montmorillonite and a vinyl-based polymer compound is described in "Composite Material Production Method and Resin Molding Material Containing the Composite Material" (Japanese Patent Laid-Open No. 6-41346). It has been disclosed.
[0009]
Further, Unitika's "Reinforced Polyamide Resin Composition and Method for Producing the Same" (JP-A-6-248176) discloses a method for producing a polyamide resin composite material obtained by heat-polymerizing fluorine mica and a polyamide monomer.
[0010]
Further, Toyobo's "Thermoplastic polyester composition, method for producing the same, and molded article thereof (JP-A-7-26123)" discloses a method for producing a composite material of clay and a polyester resin.
[0011]
These are all obtained by intercalating a high molecular compound between layers in a layered material of an inorganic filler such as clay or talc. Although these nanocomposites also have improved strength properties, there are limitations on the parts that can be used because of their hygroscopicity and insufficient surface hardness.
[0012]
Further, Mitsubishi Chemical's "aromatic polycarbonate resin composition" (JP-A-7-207134, JP-A-7-228764) and "thermoplastic resin composition" (JP-A-7-331092) describe polycarbonate and Due to the production method by melt mixing with silicate, uniform dispersion of layered silicate is insufficient, and it cannot be used for resin parts having high required characteristics.
[0013]
Furthermore, Mitsubishi Chemical's "Aromatic polycarbonate resin composition and optical communication parts" (Japanese Patent Application Laid-Open No. 8-73723) discloses that rare earth elements (erbium, erbium, (Praseodymium, neodymium) acetate is mixed, and polycarbonate is mixed with metal elements. In this case, these have a refractive index increased from 1.58 to 1.61 as compared with polycarbonate alone, but the light transmittance (minimum value) is 77 to 76 and there is no change. However, since the strength, elastic modulus, surface hardness and heat resistance are not improved, it cannot be used for resin parts for automobiles having high required characteristics.
[0014]
In a paper by Takiron Co., Ltd., "Dispersion of Carbon Nanotubes in Polymer by Twin Screw Extruder" (Molding, Vol. 14, No. 2002), untreated carbon nanotubes were melted in polycarbonate with a twin screw extruder. Although there is an example in which mixing and dispersibility are evaluated, improvement of the properties of the composition by surface treatment has not been studied.
[0015]
Further, Toray's "Carbon-Containing Resin Composition, Molding Material, and Molded Product" (Japanese Patent Application Laid-Open No. 2003-12939) discloses that a carbon nanotube, a resin, and a filler are melt-mixed. And the moldability and mechanical properties are not improved, and are not suitable for practical use.
[0016]
Further, in the “resin window and its manufacturing method (Japanese Patent Application Laid-Open No. 11-343349)”, silica fine particles may be blended in the process of synthesizing the acrylic resin. Because of this, heat resistance and impact resistance are insufficient, and it is not practical. Further, in the examples of this patent, a method is disclosed in which a polycarbonate resin is dissolved in a methylene chloride solvent, and silica fine particles are mixed therein. However, when the silica concentration is high, mixing and dispersion becomes difficult, and the strength, elastic modulus, Insufficient impact resistance, etc., making it impractical.
[0017]
[Problems to be solved by the invention]
Resin composition using polycarbonate resin obtained by conventional manufacturing method has smaller strength and rigidity than steel plate and aluminum plate. The effect of conversion is reduced.
[0018]
Further, the polycarbonate resin composition is coated because the surface is easily scratched. However, the surface is hardly coated by ordinary coating, and the coating is easily scratched when used for a long time. For this reason, high-temperature baking is necessary, but there is a problem that the conventional polycarbonate resin composition does not have a sufficiently high heat distortion temperature.
[0019]
In addition, the polycarbonate resin composition has a larger coefficient of thermal expansion than steel and aluminum plates, and the outer and interior parts of the car have large dimensions. In summer, the surface of the polycarbonate resin composite material becomes wavy due to thermal expansion. As a result, the surface smoothness was insufficient and it could not be used.
[0020]
An object of the present invention is to improve various properties of a polycarbonate resin composition such as strength, rigidity, heat deformation temperature, and coefficient of thermal expansion.
[0021]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides:
Carbon nanotubes,
And a 2,2-bis (4-hydroxyphenyl) propane chemically bonded to the surface of the carbon nanotube via an ester bond.
[0022]
Also, the present invention
Carbon nanotubes,
And a polycarbonate chemically bonded to the surface of the carbon nanotube via an ester bond.
[0023]
Further, the present invention provides
Carbon nanotubes,
And a carboxyl group chemically bonded on the surface of the carbon nanotube.
[0024]
Also, the present invention
Carbon nanotubes,
A chlorinated acyl group chemically bonded on the surface of the carbon nanotube.
[0025]
The present inventors have conducted intensive studies to achieve the above object. In order to improve various properties such as strength and rigidity of the polycarbonate resin composition, various changes may be made to the molecular structure of the polycarbonate constituting the resin composition, but the molecular structure alone may improve the properties. Has limitations. Therefore, the present inventors have conducted a search for a filler capable of realizing improved characteristics by being contained in the resin composition, and as a result, came to pay attention to carbon nanotubes.
[0026]
However, when carbon nanotubes are to be blended into a polycarbonate resin using a conventional kneading method, the carbon nanotubes aggregate during the kneading, and the properties obtained by blending the carbon nanotubes can be sufficiently obtained. Did not. Therefore, the present inventors have conducted various studies on a method of blending the carbon nanotube into the polycarbonate resin.
[0027]
As a result, based on the production method described in detail below, a carboxyl group is formed on the surface of the carbon nanotube, and then, a carbon nanotube filler in which the carboxyl group is converted to a chlorinated acyl group is prepared. A resin composition intermediate in which 2,2-bis (4-hydroxyphenyl) propane (hereinafter, referred to as “bisphenol A”) is ester-bonded to a material, and then the resin composition intermediate is applied to the resin composition intermediate based on the phosgene method. It has been found that by performing a polycondensation reaction to form a resin composition, the resin composition exhibits a configuration in which polycarbonate is chemically bonded to the carbon nanotubes via an ester bond.
[0028]
Therefore, since the finally obtained resin composition has a structure in which polycarbonate is chemically bonded to the carbon nanotubes as nuclei, the carbon nanotubes are necessarily dispersed uniformly in the resin composition. At the same time, the carbon nanotubes are strongly bonded to the polycarbonate resin. Accordingly, various properties such as strength, rigidity, heat deformation temperature, and coefficient of thermal expansion of the resin composition are improved in conjunction with the effect of blending carbon nanotubes as a filler. As a result, it can be used for various purposes such as exterior parts and outer panel parts for vehicles.
[0029]
The details and other features of the present invention, a method for manufacturing a resin plastic material, a molded body, a part, and a method for manufacturing these will be described in the following embodiments of the invention.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
(Resin composition intermediate and carbon nanotube filler)
In order to obtain a resin composition as a final product of the present invention, first, a predetermined carbon nanotube filler is prepared. The carbon nanotube filler is produced as follows.
[0031]
First, a predetermined carbon nanotube is subjected to an acid treatment or a hydrogen peroxide treatment to form a carboxyl group chemically bonded to the surface of the carbon nanotube. The acid treatment and the hydrogen peroxide treatment are preferably performed in an acidic solution. This makes it possible to easily form a carboxyl group while suppressing aggregation of carbon nanotubes.
[0032]
Further, by applying ultrasonic waves to the acidic solution, the effect of dispersing the carbon nanotubes in the acidic solution can be enhanced, and aggregation of the carbon nanotubes can be more effectively suppressed. Become.
[0033]
Next, a chlorinated acyl group treatment is performed on the carbon nanotube to convert the carboxyl group into a chlorinated acyl group. The chlorinated acyl group treatment is preferably performed by dispersing the carbon nanotubes in an organic solvent such as N, N-dimethylformamide (DMF) and adding a predetermined chlorinated acyl compound to the solvent.
[0034]
The chlorinated acyl group treatment can be easily performed by using thionyl chloride as the chlorinated acyl compound.
[0035]
The method of introducing a carboxyl group by the acid treatment of the carbon nanotube surface and introducing a chlorinated acyl group by thionyl chloride is described in Y. Sum, W.S. Huang et al. (Chem. Mater. 2001, 13, 2864-28699). Here, what is related to the present invention will be described based on references.
[0036]
Add carboxyl groups to the end surface and side surface of carbon nanotubes by placing carbon nanotubes in a stock solution of strong acid (concentrated hydrochloric acid, concentrated nitric acid, concentrated sulfuric acid, mixed acid, and aqua regia) and heating and refluxing or ultrasonic treatment. Is possible. Then, when thionyl chloride is allowed to act on the carbon nanotube in an organic solvent such as N, N-dimethylformamide (DMF), the carboxyl group can be changed to a chlorinated acyl group. The reaction formula at this time is shown below.
CNT-COOH + SOCl ₂ → CNT-COCl + HCl + SO ₂ ↑ (CNT: carbon nanotube)
[0037]
After preparing the carbon nanotube filler as described above, the carbon nanotube filler is dispersed and mixed in an organic solvent such as a chlorinated hydrocarbon, and bisphenol A is blended. As a result, the bisphenol A chemically bonds to the surface of the carbon nanotube via an ester bond, so that the resin composition intermediate of the present invention can be obtained.
[0038]
Examples of the chlorinated hydrocarbon include methylene chloride, 1,2-dichloroethane, chloroform, and chlorobenzene.
[0039]
The dehydrochlorination reaction can be carried out using an organic base catalyst such as pyridine, triethylamine and dimethylaniline, and it is particularly preferable to use pyridine.
[0040]
FIG. 1 shows a reaction formula for obtaining the resin composition intermediate from the carbon nanotube filler.
[0041]
In addition, the above-mentioned resin composition intermediate can also be performed as a part of the polycondensation reaction step when producing the resin composition.
[0042]
Further, the ester bond in the resin composition intermediate can be confirmed by an infrared absorption spectrum. Specifically, it can be determined from the fact that the infrared absorption spectra of the chlorinated acyl group and the hydroxyl group of bisphenol A decrease and the infrared absorption spectrum of the ester bond increases.
[0043]
In the resin composition intermediate, the carbon nanotube exists as a single layer or a multi-layer. In addition, the form is a fibrous continuous body having an aspect ratio of 20 to 20,000, a thickness of 1 to 50 nm, and a length of 1 to 20 μm.
[0044]
In preparing the carbon nanotube filler, by appropriately controlling the concentration of the acidic solution and the application time of the ultrasonic wave used for forming the carboxyl group on the surface of the carbon nanotube, The length can be 380 nm or less, which is less than the visible light wavelength region, and further 200 nm or less. Thereby, the transparency of the finally obtained resin composition can be sufficiently ensured.
[0045]
Specifically, the length of the carbon nanotubes can be reduced by increasing the concentration of the acidic solution and increasing the ultrasonic application time.
[0046]
(Resin composition)
After preparing the resin composition intermediate as described above, the resin composition intermediate is subjected to a polycondensation reaction by the phosgene method to prepare a target resin composition. Specifically, in an organic solvent such as the chlorinated hydrocarbon, by mixing phosgene simultaneously with or after forming the resin composition intermediate, a polycondensation reaction using the organic base catalyst is performed. I do. The reaction formula at this time is shown in FIG. 2, and the outline of the structure of the resin composition is shown in FIG.
[0047]
As is clear from FIG. 3, in the resin composition, carbon nanotubes are used as nuclei, and aromatic polycarbonates are chemically bonded around the nuclei in such a manner as to spread molecular chains. Accordingly, it can be seen that in the resin composition, the carbon nanotubes are uniformly dispersed and strongly bonded to the aromatic polycarbonate. As a result, various properties such as strength, rigidity, heat deformation temperature, and coefficient of thermal expansion of the resin composition are improved along with the effect of the carbon nanotube as a filler.
[0048]
Since the above-mentioned resin composition is obtained from the resin composition intermediate, the form of the carbon nanotubes present therein is, like the intermediate, a single-layer or multi-layer, and the aspect ratio is 20. It is a fibrous continuous body having a thickness of 1 nm to 50 nm and a length of 1 μm to 20 μm. Accordingly, a high reinforcing effect and a linear expansion coefficient reducing effect can be exhibited as a filler for the resin composition.
[0049]
Further, when the length of the carbon nanotube in the above-mentioned resin composition intermediate is 380 nm or less, and further 200 nm or less, the transparency of the resin composition can be ensured.
[0050]
Further, the amount of the carbon nanotubes in the resin composition is preferably 0.1% by weight to 50% by weight.
[0051]
As a method for obtaining polycarbonate, there is a transesterification method in addition to the phosgene method described above. However, this method generally cannot obtain a high-molecular-weight polycarbonate and has low strength and elastic modulus, so that it cannot satisfy the required specifications of automobile parts and the like.
[0052]
(Use of resin composition)
The resin composition obtained as described above is subjected to a molding process such as melt extrusion molding, injection molding, and blow molding, depending on the size and curvature of the target molded product, to obtain the target molded product. It is possible to get. Since this molded article is excellent in various properties such as strength, rigidity, heat deformation temperature, and coefficient of thermal expansion, it can be applied to exterior parts or outer panel parts for vehicles.
[0053]
Specifically, as shown in FIG. 4, a bumper and a side molding can be exemplified as exterior parts, and front panel parts such as a front fender, a door outer, a rear hender, a hood, a back door outer, and a roof can be exemplified as outer panel parts. And the like. Further, as a component having smoke and containing light transmission, a tail lamp cover and the like can be exemplified.
[0054]
【Example】
(Example 1)
First, 228 g of bisphenol A was dissolved in 250 ml of methylene chloride. Next, in the obtained solution, commercially available carbon nanotubes (monolayer: trade name (BUCKYTUBES), manufactured by CNI (Carbon Nanotechnologies, Inc.)) are previously surface-treated with chlorinated acyl groups to obtain carbon nanotubes. Was added, and then 15 ml of a pyridine solution was added as a catalyst for the dehydrochlorination reaction, and the mixture was stirred for about 1 hour. Bisphenol A was covalently bonded to the chlorinated acyl group on the carbon nanotube surface. A composition intermediate was obtained.
[0055]
Next, phosgene was stirred into the solution containing the resin composition intermediate at a rate of 2 g / min for about 50 minutes while being blown. Next, 15 ml of a 1% triethylamine methylene chloride solution was added as a dehydrochlorination reaction catalyst, and the mixture was stirred for about 1 hour to polycondensate bisphenol A and phosgene to obtain a polycarbonate solution having carbon nanotubes covalently bonded thereto.
[0056]
Next, the obtained polymer solution was neutralized with phosphoric acid, washed with water, dropped into methanol to precipitate a polymer composition, and then filtered and dried to obtain a resin composition powder. The content of carbon nanotubes in the obtained resin composition powder was about 5% by weight.
[0057]
Subsequently, the resin composition powder was dried and pulverized, and a hot press molding was performed to obtain a sheet-like molded product. In the obtained sheet-like molded product, improvement in strength and elastic modulus and decrease in coefficient of thermal expansion were observed as compared with the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example. It was also found that the carbon nanotubes were uniformly dispersed in the sheet-like molded product. Table 1 shows the results.
[0058]
(Example 2)
A resin composition intermediate in the same manner as in Example 1 except that a single-walled carbon nanotube was replaced with a multi-walled carbon nanotube (manufactured by Tsinghua-Nafine Nano-Powder Commercialization Engineering Center, product number type (TsNa-MWCnt2)) A body was prepared, and a resin composition powder was prepared. The resin composition powder was dried, pulverized, and hot-pressed to obtain a sheet-shaped molded product. In the obtained sheet-shaped molded product, improvement in strength and elastic modulus and decrease in coefficient of thermal expansion were observed as compared with the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example. It was also found that the carbon nanotubes were uniformly dispersed in the sheet-like molded product. Table 1 shows the results.
[0059]
(Example 3)
A resin composition intermediate was prepared and a resin composition powder was prepared in the same manner as in Example 1, except that the blending amount of the carbon nanotube was changed from about 5% by weight to about 3.5% by weight. The blending amount of the carbon nanotubes in the resin composition powder was about 3.5% by weight. The resin composition powder was dried, pulverized, and subjected to hot press molding to obtain a sheet-like molded product. In the obtained sheet-like molded product, improvement in strength and elastic modulus and decrease in coefficient of thermal expansion were observed as compared with the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example. Further, it was found that the carbon nanotubes were uniformly dispersed in the sheet-like molded product. Table 1 shows the results.
[0060]
(Example 4)
A resin composition intermediate in the same manner as in Example 1 except that a single-walled carbon nanotube was replaced with a multi-walled carbon nanotube (manufactured by Tsinghua-Nafine Nano-Powder Commercialization Engineering Center, product number type (TsNa-MWCnt2)) A body was prepared, and a resin composition powder was prepared. The resin composition powder was dried, pulverized, and hot-pressed to obtain a sheet-shaped molded product. In the obtained sheet-like molded product, improvement in strength and elastic modulus and a slight decrease in coefficient of thermal expansion were observed as compared with the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example. It was also found that the carbon nanotubes were uniformly dispersed in the sheet-like molded product. Table 1 shows the results. Improvement in strength and elastic modulus and decrease in thermal expansion coefficient were observed. Table 1 shows the results.
[0061]
(Example 5)
First, 26 g of bisphenol A was dissolved in 250 ml of methylene chloride. Next, in the obtained solution, commercially available carbon nanotubes (single-walled) (single-walled: CNI (Carbon Nanotechnologies, Inc.), trade name (BUCKYTUBES)) were previously surface-treated with chlorinated acyl groups. 750 ml of methylene chloride in which 13 g of carbon nanotubes were mixed and dispersed was added, and then 15 ml of a pyridine solution was blended as a catalyst for the dehydrochlorination reaction and stirred for about 1 hour to cause bisphenol A to covalently bond to the chlorinated acyl group on the carbon nanotube surface. A resin composition intermediate was obtained.
[0062]
Next, the solution containing the resin composition intermediate was neutralized with phosphoric acid, washed with water, dropped into methanol to precipitate the polymer composition, filtered and dried to obtain a powder of the resin composition intermediate. .
[0063]
Next, 202 g of a polycarbonate resin (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) is dissolved in 456 g of a methylene chloride solution, and a solution containing the resin composition intermediate is blended in the obtained solution to disperse the resin composition intermediate. , A mixed solution of polycarbonate resin / carbon nanotubes was prepared. This mixed solution was dropped into methanol to precipitate a resin composition, which was filtered and dried to obtain a powder.
[0064]
Next, the resin composition powder was dried and pulverized, and a hot press molding was performed to obtain a sheet-like molded product. In the obtained sheet-like molded product, improvement in strength and elastic modulus and decrease in coefficient of thermal expansion were observed as compared with the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example. It was also found that the carbon nanotubes were uniformly dispersed in the sheet-like molded product. Table 1 shows the results.
[0065]
(Example 6)
A resin composition intermediate in the same manner as in Example 5 except that a single-walled carbon nanotube was replaced with a multi-walled carbon nanotube (manufactured by Tsinghua-Nafine Nano-Powder Commercialization Engineering Center, part number type (TsNa-MWCnt2)) A body was prepared, and a resin composition powder was prepared. The resin composition powder was dried, pulverized, and hot-pressed to obtain a sheet-shaped molded product. In the obtained sheet-like molded product, improvement in strength and elastic modulus and decrease in coefficient of thermal expansion were observed as compared with the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example. It was also found that the carbon nanotubes were uniformly dispersed in the sheet-like molded product. Table 1 shows the results.
[0066]
(Example 7)
After preparing a resin composition intermediate in the same manner as in Example 1, 202 g of a polycarbonate resin (Iupilon S2000 manufactured by Mitsubishi Engineering Plastics) was melted with a small kneader, and a solution containing the resin composition intermediate was mixed with the melt. At the same time, the polycarbonate resin / carbon nanotube composition was obtained by dispersing the resin composition intermediate. Next, the resin composition was pulverized into a powder. Next, the obtained resin composition powder was dried and pulverized, and a sheet-like molded product was obtained by hot press molding. In the obtained sheet-like molded product, improvement in strength and elastic modulus and decrease in coefficient of thermal expansion were observed as compared with the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example. It was also found that the carbon nanotubes were uniformly dispersed in the sheet-like molded product. Table 1 shows the results.
[0067]
(Example 8)
A resin composition intermediate in the same manner as in Example 7, except that a single-walled carbon nanotube was replaced with a multi-walled carbon nanotube (manufactured by Tsinghua-Nafine Nano-Powder Commercialization Engineering Center, part number type (TsNa-MWCnt2)) A body was prepared, and a resin composition powder was prepared. The resin composition powder was dried, pulverized, and hot-pressed to obtain a sheet-shaped molded product. In the obtained sheet-like molded product, improvement in strength and elastic modulus and decrease in coefficient of thermal expansion were observed as compared with the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example. It was also found that the carbon nanotubes were uniformly dispersed in the sheet-like molded product. Table 1 shows the results.
[0068]
[Table 1]

[0069]
(Comparative Example 1)
13 g of commercially available carbon nanotubes (single-layer: manufactured by CNI (Carbon Nanotechnologies, Inc.), trade name (BUCKYTUBES)) and 228 g of polycarbonate resin (manufactured by Iupilon S2000 Mitsubishi Engineering Plastics) were melt-mixed with a small kneader to obtain a mixture. The resin composition was pulverized and subjected to hot press molding to obtain a sheet-like molded product. The obtained sheet-like molded product has a slight improvement in strength and a slight improvement in elastic modulus as compared with the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example, Also, a slight decrease in the coefficient of thermal expansion was observed.
However, it was not sufficient as compared with the above-described embodiment. Further, the carbon nanotubes tended to aggregate in the sheet-like molded product.
[0070]
(Comparative Example 2)
A resin composition was prepared in the same manner as in Comparative Example 1 except that a single-walled carbon nanotube was replaced with a multi-walled carbon nanotube (manufactured by Tsinghua-Nafine Nano-Powder Commercialization Engineering Center, product number type (TsNa-MWCnt2)). Thus, a sheet-like molded product was obtained. In this sheet-like molded product, the strength is slightly improved, the elastic modulus is slightly improved, and the coefficient of thermal expansion is slightly improved as compared with the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example. Slightly decreased. However, it was not sufficient as compared with the above-described embodiment. Further, the carbon nanotubes tended to aggregate in the sheet-like molded product. Table 2 shows the results.
[0071]
(Comparative Example 3)
A resin composition was obtained in the same manner as in Comparative Example 1 except that the blending amount of the carbon nanotube was changed from 13 g to 8.5 g, thereby obtaining a sheet-like molded product. In this sheet-like molded product, the strength was slightly improved, the elastic modulus was slightly improved, and the coefficient of thermal expansion was slightly higher than the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example. Slightly decreased. However, it was not sufficient as compared with the above-described embodiment. Further, the carbon nanotubes tended to aggregate in the sheet-like molded product. Table 2 shows the results.
[0072]
(Comparative Example 4)
A resin composition was prepared in the same manner as in Comparative Example 3 except that a single-walled carbon nanotube was replaced with a multi-walled carbon nanotube (manufactured by Tsinghua-Nafine Nano-Powder Commercialization Engineering Center, product number type (TsNa-MWCnt2)). Thus, a sheet-like molded product was obtained. In this sheet-like molded product, the strength is slightly improved, the elastic modulus is slightly improved, and the coefficient of thermal expansion is slightly improved as compared with the case of the polycarbonate resin alone (Iupilon S2000, manufactured by Mitsubishi Engineering Plastics) shown in Reference Example. Slightly decreased. However, it was not sufficient as compared with the above-described embodiment. Further, the carbon nanotubes tended to aggregate in the sheet-like molded product. Table 2 shows the results.
[0073]
[Table 2]

[0074]
As described above, the present invention has been described in detail with reference to the embodiments of the present invention. However, the present invention is not limited to the above contents, and various modifications and changes can be made without departing from the scope of the present invention. It is.
[0075]
【The invention's effect】
According to the present invention, a resin having excellent mechanical properties (particularly, bending strength, flexural modulus, linear expansion coefficient) and moldability (flowability during molding, etc.) and, if necessary, excellent conductivity. Compositions, molding materials can be provided. If such a resin composition and a molding material are used to form an outer panel and exterior parts for a vehicle, the parts are lightweight, have excellent mechanical properties, appearance quality, and conductivity, and thus have good electrostatic coating. Is obtained.
[Brief description of the drawings]
FIG. 1 is a reaction formula for obtaining a resin composition intermediate from a carbon nanotube filler.
FIG. 2 is a reaction formula for obtaining a resin composition from a resin composition intermediate.
FIG. 3 is a view schematically showing a structure of a resin composition.
FIG. 4 is an external perspective view from the rear side of a wagon-based vehicle illustrating the positions of vehicle exterior parts and outer panel parts.

Claims

Carbon nanotubes,
A resin composition intermediate, comprising: 2,2-bis (4-hydroxyphenyl) propane chemically bonded to the surface of the carbon nanotube via an ester bond.

The resin composition intermediate according to claim 1, wherein the carbon nanotube has a single-walled or multi-walled structure.

3. The carbon nanotube according to claim 1, wherein the carbon nanotube is a fibrous continuous body having an aspect ratio of 20 to 20,000, a thickness of 1 to 50 nm, and a length of 1 to 20 μm. 4. Resin composition intermediate.

The resin composition intermediate according to claim 3, wherein the length of the carbon nanotube is 380 nm or less.

The resin composition intermediate according to claim 4, wherein the carbon nanotube has a length of 200 nm or less.

Carbon nanotubes,
And a polycarbonate chemically bonded to the surface of the carbon nanotube via an ester bond.

The resin composition according to claim 6, wherein the carbon nanotube is a single-walled or multi-walled carbon nanotube.

8. The carbon nanotube according to claim 6, wherein the carbon nanotube is a fibrous continuous body having an aspect ratio of 20 to 20,000, a thickness of 1 nm to 50 nm, and a length of 1 μm to 20 μm. 9. Resin composition.

The resin composition according to claim 8, wherein the length of the carbon nanotube is 380 nm or less.

The resin composition according to claim 9, wherein the length of the carbon nanotube is 200 nm or less.

The resin composition according to claim 6, wherein the content of the carbon nanotube is 0.1% by weight to 50% by weight.

The resin composition according to any one of claims 6 to 11, wherein the polycarbonate is an aromatic polycarbonate.

Carbon nanotubes,
And a carboxyl group chemically bonded on the surface of the carbon nanotube.

Carbon nanotubes,
A chlorinated acyl group chemically bonded on the surface of the carbon nanotube.

The carbon nanotube filler according to claim 13, wherein the carbon nanotube is a single-walled or multi-walled carbon nanotube.

The carbon nanotube according to any one of claims 13 to 15, wherein the carbon nanotube is a fibrous continuous body having an aspect ratio of 20 to 20,000, a thickness of 1 to 50 nm, and a length of 1 to 20 µm. The carbon nanotube filler according to claim 1.

The carbon nanotube filler according to claim 16, wherein the length of the carbon nanotube is 380nm or less.

18. The carbon nanotube filler according to claim 17, wherein the length of the carbon nanotube is 200 nm or less.

Performing an acid treatment or a hydrogen peroxide treatment on the carbon nanotube to form a carboxyl group on the surface of the carbon nanotube,
A step of forming a chlorinated acyl group on the surface of the carbon nanotube by treating the carboxyl group of the carbon nanotube with a chlorinated acyl group;
The chlorinated acyl group of the carbon nanotube and the hydroxyl group of 2,2-bis (4-hydroxyphenyl) propane are chemically bonded through a dechlorination reaction, and the carbon nanotube and the 2,2-bis (4-hydroxy Forming a resin composition intermediate in which phenyl) propane is chemically bonded via an ester bond.

The method according to claim 19, wherein the acid treatment or the hydrogen peroxide treatment is performed in a state where the carbon nanotubes are dispersed in an acidic solution.

21. The method according to claim 20, wherein the carbon nanotubes are dispersed in the acidic solution using ultrasonic waves.

22. The method for producing a resin composition intermediate according to claim 20, wherein the length of the carbon nanotube is changed by controlling an acid concentration of the acidic solution.

The method for producing a resin composition intermediate according to any one of claims 20 to 22, wherein a length of the carbon nanotube is changed by controlling an application time of the ultrasonic wave.

The method for producing a resin composition intermediate according to any one of claims 20 to 23, wherein the chlorinated acyl group treatment is performed using thionyl chloride.

The method for producing a resin composition intermediate according to any one of claims 19 to 24, wherein the dechlorination reaction is performed using a pyridine catalyst.

The dechlorination reaction is carried out in a state where the 2,2-bis (4-hydroxyphenyl) propane is dissolved in an organic solvent and the carbon nanotubes are dispersed in the organic solvent. Item 29. The method for producing a resin composition intermediate according to any one of Items 19 to 25.

The method for producing a resin composition intermediate according to claim 26, wherein the organic solvent is a chlorinated hydrocarbon.

28. The method according to claim 27, wherein the chlorinated hydrocarbon is at least one of methylene chloride, 1,2-dichloroethane, chloroform, and chlorobenzene.

Performing an acid treatment or a hydrogen peroxide treatment on the carbon nanotube to form a carboxyl group on the surface of the carbon nanotube,
A step of forming a chlorinated acyl group on the surface of the carbon nanotube by treating the carboxyl group of the carbon nanotube with a chlorinated acyl group;
The chlorinated acyl group of the carbon nanotube and the hydroxyl group of 2,2-bis (4-hydroxyphenyl) propane are chemically bonded through a dechlorination reaction, and the carbon nanotube and the 2,2-bis (4-hydroxy Forming a resin composition intermediate in which phenyl) propane is chemically bonded via an ester bond;
Subjecting the resin composition intermediate to a polycondensation reaction by the phosgene method to form a resin composition in which the carbon nanotubes and the polycarbonate are chemically bonded via ester bonds. A method for producing a resin composition.

The method for producing a resin composition according to claim 29, wherein the acid treatment or the hydrogen peroxide treatment is performed in a state where the carbon nanotubes are dispersed in an acidic solution.

31. The method according to claim 30, wherein the carbon nanotubes are dispersed in the acidic solution using ultrasonic waves.

The method according to claim 30 or 31, wherein the length of the carbon nanotube is changed by controlling an acid concentration of the acidic solution.

The method for producing a resin composition according to any one of claims 30 to 32, wherein a length of the carbon nanotube is changed by controlling an application time of the ultrasonic wave.

The method for producing a resin composition according to any one of claims 29 to 33, wherein the chlorinated acyl group treatment is performed using thionyl chloride.

The method for producing a resin composition according to any one of claims 29 to 34, wherein the dechlorination reaction is performed using a pyridine catalyst.

The dechlorination reaction is carried out in a state where the 2,2-bis (4-hydroxyphenyl) propane is dissolved in an organic solvent and the carbon nanotubes are dispersed in the organic solvent. Item 40. The method for producing a resin composition according to any one of Items 29 to 35.

37. The method according to claim 36, wherein the organic solvent is a chlorinated hydrocarbon.

The method according to claim 37, wherein the chlorinated hydrocarbon is at least one of methylene chloride, 1,2-dichloroethane, chloroform, and chlorobenzene.

A method for producing a carbon nanotube filler, wherein a carboxyl group is formed on the surface of the carbon nanotube by subjecting the carbon nanotube to an acid treatment or a hydrogen peroxide treatment.

The method for producing a carbon nanotube filler according to claim 39, wherein the acid treatment or the hydrogen peroxide treatment is performed in a state where the carbon nanotubes are dispersed in an acidic solution.

41. The method of claim 40, wherein the carbon nanotubes are dispersed in the acidic solution using ultrasonic waves.

42. The method for producing a carbon nanotube filler according to claim 40, wherein the length of the carbon nanotube is changed by controlling an acid concentration of the acidic solution.

The method for producing a carbon nanotube filler according to any one of claims 40 to 42, wherein a length of the carbon nanotube is changed by controlling an application time of the ultrasonic wave.

Performing an acid treatment or a hydrogen peroxide treatment on the carbon nanotube to form a carboxyl group on the surface of the carbon nanotube,
Forming a chlorinated acyl group on the surface of the carbon nanotube by treating the carboxyl group of the carbon nanotube with a chlorinated acyl group, the method comprising the steps of: .

The method for manufacturing a carbon nanotube filler according to claim 44, wherein the acid treatment or the hydrogen peroxide treatment is performed in a state where the carbon nanotubes are dispersed in an acidic solution.

The method of claim 45, wherein the carbon nanotubes are dispersed in the acidic solution using ultrasonic waves.

The method according to claim 45 or 46, wherein the length of the carbon nanotube is changed by controlling an acid concentration of the acidic solution.

The method for producing a carbon nanotube filler according to any one of claims 45 to 47, wherein a length of the carbon nanotube is changed by controlling an application time of the ultrasonic wave.

The method for producing a carbon nanotube filler according to any one of claims 45 to 48, wherein the chlorinated acyl group treatment is performed using thionyl chloride.

An exterior component for a vehicle, comprising the resin composition according to any one of claims 6 to 12.

An outer panel component for a vehicle, comprising the resin composition according to any one of claims 6 to 12.