JP2004143212A

JP2004143212A - Polymer composite, drawn product thereof and method for producing polymer composite

Info

Publication number: JP2004143212A
Application number: JP2002307049A
Authority: JP
Inventors: Kazutoshi Haraguchi; 原口　和敏; Kan Takehisa; 武久　敢
Original assignee: Kawamura Institute of Chemical Research
Current assignee: Kawamura Institute of Chemical Research
Priority date: 2002-10-22
Filing date: 2002-10-22
Publication date: 2004-05-20
Anticipated expiration: 2022-10-22
Also published as: JP3914489B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer composite uniformly finely dispersing a clay mineral in an organic polymer and exhibiting excellent drawability and mechanical properties such as strength or modulus of elasticity in a wide range of clay mineral contents and to provide a drawn product thereof and a method for producing the polymer composite. <P>SOLUTION: The polymer composite is characterized by forming an organic polymer (A) composed of a polymer of an acrylic or a methacrylic ester (a) or a copolymer of at least one kind (b) of (meth)acrylamide and an N-substituted (meth)acrylamide and the acrylic or the methacrylic ester (a) and a water-swellable clay mineral (B) into a three-dimensional network. The drawn product and the method for producing the polymer composite are provided. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は有機高分子と粘土鉱物とが三次元網目を形成してなる高分子複合体、その延伸物および該高分子複合体の製造方法に関する。
【０００２】
【従来の技術】
有機高分子と無機材料を複合化して得られる高分子複合材料としては、ガラス繊維、炭素繊維などの他、タルクや炭酸カルシウムなどを有機高分子に充填したものが古くから知られている。近年、有機高分子の中にナノメートルスケールの微少サイズの無機成分を分散し複合化することより、優れた力学物性や熱特性の改良が発現され、有機・無機ナノコンポジット材料として注目を浴びている。
【０００３】
ここで無機成分としては、ゾルゲル反応を利用して合成される金属酸化物、もしくは層状に剥離することが可能な粘土鉱物が主として用いられている（例えば、非特許文献１、非特許文献２参照。）。
【０００４】
この内、粘土鉱物を無機成分とするものは層状粘土のアスペクト比が大きいことにより、力学物性やガス遮蔽性などの改良に効果的である。かかる粘土鉱物と有機高分子との複合体（ナノコンポジット）においては、粘土層を有機高分子の中に微細に分散すること、また粘土層と有機高分子との相互作用を高めることが重要である。そのために、例えば有機高分子を無水マレイン酸やオキサゾリンなどで変性することや、粘土鉱物として、安価ではあるが有機高分子中に分散しにくい無機粘土鉱物ではなく、該粘土鉱物を予めアルキルアンモニウムカチオンなどで処理して層間の距離を広げ、層状剥離をしやすくすると共に有機溶媒や有機高分子に分散しやすくしたもの（未処理の粘土を無機粘土と呼ぶのに対して、有機化粘土と呼ぶ）が多く用いられている。
【０００５】
これまで、ポリアミド、ポリスチレン、ポリプロピレン、ポリイミド、ポリウレタンなどの有機高分子を粘土と複合化することによりナノコンポジットと呼ばれる高分子複合体が調製されている。得られた高分子複合体はアスペクト比の大きい粘土層を微細に分散させていることから、弾性率、熱変形温度、ガス透過性、及び燃焼速度などが効果的に改良することが報告されている。（例えば、非特許文献３参照。）。
【０００６】
かかる高分子複合体中に含まれる粘土鉱物量としては、性能強化の観点からは高い粘土鉱物含有が望まれるが、より低い粘土鉱物量で効果的な性能強化が達成されることも重要である。これまでの研究では通常０．２〜５質量％が用いられ、０．１質量％以下の低無機含有高分子複合体や１０質量％を超える高無機含有高分子複合体は用いられていない。これは無機含有率が低くなると性能向上の効果が無視されるほど小さくなり、一方、無機含有率が高くなると製造時の粘度が大きく上昇して得られる複合体中でのナノスケールでの微細且つ均一な分散が達成できなかったり、また複合体の成形性が極端に低下して任意の形に均一成形できなかったり、更には複合体が脆くなり力学物性（強度や伸び）が大きく低下するためである。
【０００７】
このため、粘土鉱物含有率が低くても効果的な性能向上を実現できる高分子複合体や、粘土鉱物含有率が高い高分子複合体であっても、無機成分の均一微細分散を達成し、優れた機械的性質を有する高分子複合体の開発が望まれていた。
【０００８】
【非特許文献１】
ハラグチら（Ｋ．Ｈａｒａｇｕｃｈｉ，　ｅｔ．ａｌ．）ジャーナル・オブ・マテリアル・サイエンス（Ｊ．Ｍａｔｅｒ．Ｓｃｉ．）３３巻、　３３３７−３３４４頁、１９９８年
【０００９】
【非特許文献２】
ウスキら（Ａ．Ｕｓｕｋｉ，　ｅｔ．ａｌ．）　ジャーナル・オブ・マテリアル・リサーチ（Ｊ．Ｍａｔ．Ｒｅｓ．）８巻、１１７４−１１７８頁、１９９３年
【００１０】
【非特許文献３】
ピナバイア及びベアル編（Ｔ．Ｊ．Ｐｉｎｎａｖａｉａ　ａｎｄ　Ｇ．Ｗ．Ｂｅａｌｌ　Ｅｄｓ．）「ポリマークレイナノコンポジット」（Ｐｏｌｙｍｅｒ−Ｃｌａｙ　Ｎａｎｏｃｏｍｐｏｓｉｔｅｓ）ワイリー社（Ｗｉｌｅｙ）２０００年出版）
【００１１】
【発明が解決しようとする課題】
本発明が解決しようとする課題は、広い範囲の粘土鉱物含有率において、粘土鉱物が有機高分子中に均一微細に分散し、優れた延伸性と強度や弾性率などの力学物性を示す高分子複合体、その延伸物及び該高分子複合体の製造方法を提供することにある。
【００１２】
【課題を解決するための手段】
本発明者らは、上記課題を解決すべく鋭意研究に取り組んだ結果、（メタ）アクリル酸エステルの重合体、または（メタ）アクリルアミドとＮ−置換（メタ）アクリルアミドの少なくとも１種と（メタ）アクリル酸エステルとの共重合体からなる有機高分子（Ａ）と、水膨潤性粘土鉱物（Ｂ）とが三次元網目を形成してなる高分子複合体が広い粘土鉱物含有率範囲において粘土鉱物の均一分散性に優れ、粘土鉱物を含まない重合体または共重合体に比べて、伸度や強度などの力学物性が顕著に向上することを見出し、本発明を完成するに至った。
【００１３】
即ち、本発明は、（メタ）アクリル酸エステル（ａ）の重合体、または（メタ）アクリルアミドとＮ−置換（メタ）アクリルアミドの少なくとも１種（ｂ）と（メタ）アクリル酸エステル（ａ）との共重合体からなる有機高分子（Ａ）と、水膨潤性粘土鉱物（Ｂ）とが三次元網目を形成してなることを特徴とする高分子複合体、および該高分子複合体を延伸して得られることを特徴とする高分子複合体の延伸物を提供する。
【００１４】
また、本発明は、水または水と有機溶媒との混合溶媒中に溶解または均一に分散させた水膨潤性粘土鉱物（Ｂ）と重合開始剤または触媒の存在下に、（メタ）アクリル酸エステル（ａ）を重合させることを特徴とする高分子複合体の製造方法、および水または水と有機溶媒との混合溶媒中に溶解または均一に分散させた水膨潤性粘土鉱物（Ｂ）と重合開始剤または触媒の存在下に、（メタ）アクリルアミドとＮ−置換（メタ）アクリルアミドの少なくとも１種（ｂ）と（メタ）アクリル酸エステル（ａ）とを共重合させることを特徴とする高分子複合体の製造方法を提供する。
【００１５】
【発明の実施の形態】
本発明の高分子複合体は、（メタ）アクリル酸エステルの重合体、または（メタ）アクリルアミドとＮ−置換（メタ）アクリルアミドの少なくとも１種と（メタ）アクリル酸エステルとの共重合体からなる有機高分子（Ａ）と水膨潤性粘土鉱物（Ｂ）とが三次元網目を形成し、該有機高分子中に層状剥離可能な水膨潤性粘土鉱物を広い濃度範囲で均一に含有し、延伸性や柔軟性などの優れた力学物性を示す。
【００１６】
本発明で用いる（メタ）アクリル酸エステル、（メタ）アクリルアミド、Ｎ−置換（メタ）アクリルアミドは、水または水と有機溶媒との混合溶媒に溶解可能なものが好ましい。一方、これらを重合もしくは共重合して得られる有機高分子（Ａ）は必ずしも親水性である必要は無く、疎水性をより多く有し、水に溶解したり過度に膨潤することなく水中でも安定して存在するものが好ましい。また、高分子複合体の親水性と疎水性とのバランスを変化させたり、他の成分との相互作用を強めるために、親水性基、イオン性基及び／又は疎水性基などを必要に応じて重合体または共重合体中に導入することも可能である。
【００１７】
（メタ）アクリル酸エステル（ａ）としては、メトキシエチルアクリレート、エトキシエチルアクリレート、メトキシエチルメタクリレートまたはエトキシエチルメタクリレートなどが挙げられる。本発明の（メタ）アクリル酸エステル（ａ）の重合体は、これら（メタ）アクリル酸エステルから選ばれる単独モノマーの重合体または複数モノマーの共重合体を含む。
【００１８】
（メタ）アクリルアミドとＮ−置換（メタ）アクリルアミドとしては、（メタ）アクリルアミドとアルキル基の炭素数が１以上のアルキル（メタ）アクリルアミドであり、具体的には、Ｎ−メチルアクリルアミド、Ｎ−エチルアクリルアミド、Ｎ−シクロプロピルアクリルアミド、Ｎ−イソプロピルアクリルアミド、Ｎ，Ｎ−ジメチルアクリルアミド、Ｎ−メチル−Ｎ−エチルアクリルアミド、Ｎ−メチル−Ｎ−イソプロピルアクリルアミド、Ｎ−メチル−Ｎ−ｎ−プロピルアクリルアミド、Ｎ，Ｎ−ジエチルアクリルアミド、Ｎ−エチル−Ｎ−イソプロピルアクリルアミド、Ｎ−エチル−Ｎ−ｎ−プロピルアクリルアミド、Ｎ−アクリロイルピロリディン、Ｎ−アクリロイルピペリディン、Ｎ−アクリロイルモロフォリン、Ｎ−アクリロイルメチルホモピペラジン、Ｎ−アクリロイルメチルピペラジンまたはＮ−メチルメタクリルアミドが挙げられる。
【００１９】
有機高分子（Ａ）が（メタ）アクリルアミドとＮ−置換（メタ）アクリルアミドの少なくとも１種（ｂ）と（メタ）アクリル酸エステル（ａ）との共重合体からなる場合は、前記共重合体の（ａ）に対する（ｂ）の比は、得られる高分子複合体の室温での柔軟性が高く、水中での平衡水分率を低くするためには、モル比で０．５以下、より好ましくは０．２５以下である。
【００２０】
有機高分子（Ａ）のガラス転移温度は必ずしも限定されず、広い範囲のものが用いられ得るが、加工性や室温での延伸性や伸縮性などからは、有機高分子（Ａ）はガラス転移温度が１００℃以下であるものが好ましく、３０℃以下がより好ましく、０℃以下のものが特に好ましい。
【００２１】
水膨潤性粘土鉱物（Ｂ）としては、層状に剥離可能な膨潤性粘土鉱物が用いられ、好ましくは水もしくは水と有機溶媒との混合溶液中で膨潤し均一分散可能な粘土鉱物、特に好ましくは水中で分子状（単一層）又はそれに近いレベルで均一分散可能な無機粘土鉱物が用いられる。具体的には、水膨潤性粘土鉱物として、水膨潤性スメクタイトや水膨潤性雲母などが用いられ、より具体的には、ナトリウムを層間イオンとして含む水膨潤性ヘクトライト、水膨潤性モンモリロナイト、水膨潤性サポナイト、水膨潤性合成雲母などが挙げられる。
【００２２】
本発明の高分子複合体は、水または水と有機溶媒との混合溶媒中に溶解または均一に分散させた水膨潤性粘土鉱物（Ｂ）と重合開始剤または触媒の存在下に（メタ）アクリル酸エステル（ａ）を重合させるか、もしくは、水または水と有機溶媒との混合溶媒中に溶解または均一に分散させた水膨潤性粘土鉱物（Ｂ）と重合開始剤または触媒の存在下に、（メタ）アクリルアミドとＮ−置換（メタ）アクリルアミドの少なくとも１種（ｂ）と（メタ）アクリル酸エステル（ａ）とを共重合させることにより得られる。
【００２３】
例えば、水膨潤性粘土鉱物（Ｂ）を水または水と有機溶媒とを含む混合溶媒に均一に微細分散させた水溶液に、１種または複数の（メタ）アクリル酸エステル（ａ）、もしくは（メタ）アクリルアミドとＮ−置換（メタ）アクリルアミドの少なくとも１種（ｂ）と前記（メタ）アクリル酸エステル（ａ）とを混合したものを添加して溶解させ、次いで、開始剤及び／または触媒を添加し、電子線などの照射や加熱などの方法により水膨潤性粘土鉱物（Ｂ）の共存下でインシチュー（ｉｎ　ｓｉｔｕ）ラジカル重合させることにより、本発明の高分子複合体を得る。
【００２４】
用いる開始剤および触媒としては、公知のラジカル重合開始剤や触媒を適時選択して用いることができる。好ましくは水分散性を有し、系全体に均一に含まれるものが好ましく用いられる。具体的には、重合開始剤として、水溶性の過酸化物、例えばペルオキソ二硫酸カリウムやペルオキソ二硫酸アンモニウム、水溶性のアゾ化合物、例えばＶＡ−０４４、Ｖ−５０、Ｖ−５０１（いずれも和光純薬工業株式会社製）の他、Ｆｅ^２＋と過酸化水素との混合物などが例示される。
【００２５】
触媒としては、３級アミン化合物であるＮ，Ｎ，Ｎ’，Ｎ’−テトラメチルエチレンジアミンなどは好ましく用いられる。重合温度は、重合触媒や開始剤の種類に合わせて例えば０℃〜１００℃が用いられる。重合時間も数十秒〜数十時間の間で行うことが出来る。
【００２６】
本発明の高分子複合体は、前記有機高分子（Ａ）と水膨潤性粘土鉱物（Ｂ）とが相互作用して三次元網目を形成している。相互作用は、効果的な三次元網目を形成できれば、イオン結合、水素結合、疎水結合、配位結合、共有結合などのいずれか一つまたは複数であって良い。なお、かかる三次元網目形成を妨げない限り、またはそれを促進する目的で、前記有機高分子（Ａ）を構成する重合成分と共に他の重合性有機分子などを併用、または得られる高分子複合体に機能性を付与する目的で有機または無機の各種機能性分子や粒子を添加してよい。
【００２７】
本発明においては、高分子複合体の三次元網目形成を水膨潤性粘土鉱物で行うことが好ましく、通常の有機架橋剤を全く用いないで水膨潤性粘土鉱物のみで三次元網目を形成することが特に好ましい。有機架橋剤を用いた場合は、得られる複合体は延伸性や強度などの力学物性の低い材料となる。
【００２８】
本発明の高分子複合体は、有機高分子（Ａ）に対する水膨潤性粘土鉱物（Ｂ）の質量比が０．００３〜３であることが好ましく、より好ましくは０．００５〜２、特に好ましくは０．０１〜１である。該質量比が０．００３未満では機械的性質が高分子複合体として不十分となりやすく、３を超えては粘土鉱物の均一微細分散が困難となりやすい。
【００２９】
本発明の高分子複合体は、水膨潤性粘土鉱物の含有率によらず乾燥物は均一で透明性を有し水膨潤性粘土鉱物の凝集は観測されない。最終的な水膨潤性粘土鉱物の含有率は熱質量分析（ＴＧＡ）により、また微細分散性は透過型電子顕微鏡（ＴＥＭ）観察により測定される。本発明の高分子複合体は、用いた水膨潤性粘土鉱物の全量が高分子複合体に含まれていることがＴＧＡにより確認され、且つ１〜数ナノメーターの厚みの層状粘土層がナノメータースケールで均一に分散しているのがＴＥＭにより確認される。
【００３０】
本発明の高分子複合体は、通常用いられる有機架橋剤を一切添加していないにも拘わらず、優れた力学物性、特に高い延伸性と伸縮性を示すことから、有機高分子と微細分散した水膨潤性粘土鉱物が相互作用して三次元網目を形成していると結論される。一方、水膨潤性粘土鉱物を含まない線状高分子および有機架橋剤を添加して三次元網目を形成したものは、比較例に示すように、いずれも本発明の高分子複合体に比べて極めて低い力学物性しか示さない。このことは、本発明の高分子複合体が、従来にない効果的な三次元網目を形成していることを示唆している。具体的には均一に分布した粘土層が多官能架橋剤として有効に働くことから、架橋点間距離が長く、且つ均一に制御されることとなり、且つ架橋点間の高分子は架橋点間距離が長いことから自由鎖に近い形態をとった構造を有していると推定される。このような有機高分子と水膨潤性粘土鉱物からなる三次元網目形成により、極めて大きい延伸性や優れた破断強度が実現される。
【００３１】
かかる三次元網目構造の形成は、透過型電子顕微鏡観察による水膨潤性粘土鉱物の微細分散の他、以下に示す優れた延伸性や高い破断強度の達成、動的粘弾性測定などによる水膨潤性粘土鉱物層間の有機高分子の自由鎖に近いガラス転移温度の測定によっても確認された。
【００３２】
本発明の高分子複合体は、優れた力学物性を示し、例えば、伸びについては、１０００％〜３０００％の破断伸びを示し、３０００％以上の大きい破断伸びを有する高分子複合体も得られる。また、本発明の高分子複合体は有機架橋高分子や線状高分子に比べて非常に高い破断強度を示す。また、得られた高分子複合体を１００％以上、１００％〜１５００％に延伸することにより、より高い柔軟性や優れた伸縮性を有する高分子複合体の延伸物を得ることができる。
【００３３】
本発明の未延伸の高分子複合体は、多くの場合、高い初期弾性率および降伏点とネッキング現象及び優れた延伸性を示す。一方、これを延伸処理して得られる本発明の高分子複合体の延伸物は優れた延伸性と可逆的な回復性を示し、繰り返し延伸試験において良好な伸縮性を示す。本発明の高分子複合体の延伸は、有機高分子（Ａ）のガラス転移温度以上の温度で、一軸延伸、二軸延伸の他、圧縮、圧延、押し出しなどの慣用の方法で行うことができる。
【００３４】
本発明の高分子複合体は、乾燥状態だけでなく、乾燥サンプルに水分を吸湿させた状態でも優れた機械的性質を示す。吸湿水分率は高分子複合体の組成により変化し、必ずしも限定されないが、高分子複合体の吸湿水率が小さいほど、湿度の異なる大気中でもより安定した機械的性質を示すので、高分子複合体の吸湿水分率の範囲は、例えば温度２５℃、湿度５５％の大気中で好ましくは１００質量％以下のものであり、より好ましくは７０質量％以下のもの、特に好ましくは３０質量％以下のものである。
【００３５】
また、本発明の高分子複合体は水雰囲気でも優れた機械的性質を示す。本発明の高分子複合体の水中での平衡吸水率も、高分子複合体の組成により種々変えることができ、必ずしも限定されないが、平衡吸水率が小さい程、水中でもより安定した機械的性質を示すため、水中での平衡吸水率が５００質量％以下のものが好ましく、より好ましくは３００質量％以下のもの、特に好ましくは１００質量％以下のものである。
【００３６】
本発明の高分子複合体は、円柱状、棒状、フィルム状、糸状などの各種形状に成形でき、生体適合性、柔軟性に優れた人工透析器、人工心肺、人工血管などの人工臓器用材料や、カテーテルなどの治療用材料として、また伸縮性に優れた各種工業材料として用いられる。
【００３７】
【実施例】
次いで本発明を実施例により、より具体的に説明するが、もとより本発明は、以下に示す実施例にのみ限定されるものではない。
【００３８】
（実施例１）
水膨潤性粘土鉱物は、［Ｍｇ_５．３４Ｌｉ_０．６６Ｓｉ_８Ｏ_２０（ＯＨ）_４］Ｎａ^＋ _０．６６の組成を有する水膨潤性合成ヘクトライト（商標ラポナイトＸＬＧ、日本シリカ株式会社製）を真空乾燥して用いた。アクリレート誘導体は、２−メトキシエチルアクリレート（ＭＥＡ）（和光純薬工業株式会社製）を用いた。ＭＥＡは、シリカゲルカラム（メルク社製）を用いて重合禁止剤を取り除いてから使用した。
重合開始剤は、ペルオキソ二硫酸カリウム（ＫＰＳ：関東化学株式会社製）をＫＰＳ／水＝０．４０／２０（ｇ／ｇ）の割合で脱酸素した純水中に溶解し、水溶液にして使用した。触媒は、Ｎ，Ｎ，Ｎ’，Ｎ’−テトラメチルエチレンジアミン（ＴＥＭＥＤ：和光純薬工業株式会社製）を使用した。純水は、全て高純度窒素をあらかじめ充分にバブリングさせ、含有酸素を除去してから使用した。
【００３９】
２０℃の恒温室において、平底ガラス容器に、純水１９．０２ｇとテフロン製攪拌子を入れ、攪拌しながら０．３９６ｇのラポナイトＸＬＧを加え、無色透明の溶液を調製した。これにＭＥＡ２．３ｇを加え、攪拌して無色透明溶液を得た。次にＫＰＳ水溶液１．０ｇとＴＥＭＥＤ１６μｌを攪拌しながら加えた。この溶液の一部を底の閉じた内径５．５ｍｍ、長さ１５０ｍｍのガラス管容器３本に移した後、上部に密栓をし、２０℃の恒温水槽中で２０時間静置して重合を行った。
【００４０】
残りの水溶液も平底ガラス容器内で２０℃、２０時間静置し、重合を行った。なお、これらの溶液調製から重合までの操作は、全て酸素を遮断した窒素雰囲気下で行った。２０時間後に、平底ガラス容器内、及びガラス管内に均一な円柱状、及び棒状の固体（高分子複合体）が水中で遊離して生成した。
【００４１】
得られた高分子複合体中に水膨潤性粘土鉱物などによる不均一な凝集は観測されず、高分子複合体は均一な白色固体として得られた。１００℃で質量が一定になるまで真空乾燥することで、透明な高分子複合体を得た。乾燥質量から計算した高分子重合収率は９９．５質量％であった。なお、乾燥した高分子複合体を２５℃、湿度５０％に５日間放置した場合の水分率は４．９質量％であった。高分子複合体を乾燥後、６００℃までの熱質量分析（セイコー電子工業株式会社製ＴＧ−ＤＴＡ２２０：空気流通下、昇温：１０℃／分）を行い、粘土含有率を求めた。粘土含有率（無機粘土／高分子複合体）は１７．１質量％で重合溶液組成からの計算値とほぼ一致した。またＫＢｒ法によるフーリエ変換赤外線吸収スペクトル（ＦＴ−ＩＲ）の測定において、ポリ（２−メトキシエチルアクリレート）（ＰＭＥＡ）と水膨潤性粘土鉱物の特性ピークが確認された。
【００４２】
乾燥した高分子複合体をエポキシ樹脂中に包埋後、厚さ約５０ｍｍの超薄切片を作製し、透過型電子顕微鏡観察を行った（日本電子株式会社製ＪＥＭ−２００ＣＸを使用）ところ、１〜数ｎｍの厚みの層状粘土が微細且つ均一に分散しているのが観察された。以上の結果より、本実施例で得られた固体は、水膨潤性粘土鉱物とＰＭＥＡからなる高分子複合体であって、粘土鉱物含有率は１７．１質量％であり、且つ水膨潤性粘土鉱物が均一に微細分散したものであることが明らかとなった。この高分子複合体は、透明であり、且つ室温で９０度以上に屈曲させても破壊することのない柔軟性を示した。
【００４３】
乾燥した棒状の高分子複合体の動的粘弾性をセイコー電子工業株式会社製ＤＭＡ−２００を使用し、測定周波数１Ｈｚ、昇温２℃／分で測定した結果、高分子複合体は約−４０℃にガラス転移温度（Ｔｇ：ｔａｎδの極大値が示す温度）を示した。また、Ｔｇより低い温度では高い弾性率を示し、Ｔｇ以上の温度では広い温度範囲にわたって安定したゴム領域の弾性率を示した。
【００４４】
一方、乾燥した棒状の高分子複合体（断面積３．４０ｃｍ^２）をチャック部での滑りの無いようにして、引っ張り試験装置（株式会社島津製作所製、卓上型万能試験機ＡＧＳ−Ｈ）に装着し、評点間距離２０ｍｍ、引っ張り速度１００ｍｍ／分にて引っ張り試験を行った結果を図１に示す。図１の縦軸は荷重（Ｎ）を横軸は伸び（％）を示す。延伸初期に明確な降伏点およびその後のネッキング現象が観測され、弾性率は１５．２ＭＰａ、破断強度が１．８８ＭＰａ、破断伸びが２０１７％であった（いずれも断面積としては、初期断面積を使用）。引っ張り試験後の高分子複合体は、ゴム的な伸縮性とタフネスを示した。特に伸びは応力を除くことにより瞬間的に回復する伸縮性が見られ、元の１１７．４％の長さまで回復した。
【００４５】
以上の結果より、得られた高分子複合体は、１７．１質量％の高い無機含有複合体であるにもかかわらず、高い延伸性や屈曲性を初めとする優れた機械的性質を有することが明らかである。また、かかる優れた力学物性、有機架橋剤を何ら使用していないのにゴム的な伸縮性を有すること、及び水膨潤性粘土鉱物の微細分散性、重合体のガラス転移温度などから、本発明の高分子複合体中では、有機高分子（Ａ）と水膨潤性粘土鉱物（Ｂ）とが三次元網目を形成していると結論した。
【００４６】
（実施例２）
実施例１で得られた乾燥した高分子複合体を秤量後、２０℃の水中で質量が平衡になるまで静置し平衡吸水率を測定した。その結果、平衡吸水率（吸水量／乾燥高分子複合体質量）は、２８．２質量％であった。この高分子複合体は均一な白色固体であり、実施例１と同様の方法で引っ張り試験を行った結果、弾性率５４．８ｋＰａ、破断強度２５．３ｋＰａ、破断伸び１８５６％であり、高分子複合体は水中でも同様に、延伸性など優れた力学物性を示すことが明らかとなった。
【００４７】
（実施例３）
実施例１で得られた高分子複合体を元の長さの５倍まで一軸延伸し、そのまま長さを固定した状態で、２５℃、湿度５０％で７２時間保持した。その後、８０℃で３時間真空乾燥して、高分子複合体の延伸物を調製した。得られた高分子複合体の延伸物は柔らかく、柔軟性、屈曲性に富み、９０度の曲げ変形試験でも折れることはなく、直径１ｍｍの金属棒に巻き付けても破断したり、傷つくことはなかった。さらにこの高分子複合体の延伸物は、その後の繰り返し延伸試験においてゴム状の可逆的な変形、優れた伸縮性を示した。実施例１と同様に延伸物の引っ張り試験を行った結果、弾性率１２４ｋＰａ、破断強度１．７４ＭＰａ、破断伸び２３１０％であった。また、伸びは応力を除くことにより瞬間的に回復する伸縮性が見られ、元の長さの１２０％まで回復した。
【００４８】
（実施例４）
ＭＥＡの重合を５℃の恒温水槽中で行うこと以外は、実施例１と同様にして、高分子複合体を調製した。得られた固体は、均一な水膨潤性粘土鉱物と重合体との複合体であり、水膨潤性粘土鉱物などの不均一な凝集は観測されなかった。棒状の高分子複合体を実施例１と同様に１００℃で真空乾燥し、棒状の透明な高分子複合体を得た。実施例１と同様に測定したところ、この高分子複合体中の粘土鉱物含有率は１７．１質量％であった。また実施例１と同様にして、棒状の乾燥した高分子複合体の引っ張り試験を行ったところ、降伏点やネッキング現象を示し、弾性率１１．５ＭＰａ、破断強度２．１３ＭＰａ、破断伸び１４６５％のタフネス、柔軟性のある高分子複合体であった。引っ張り試験後の高分子複合体は、ゴム的な伸縮性とタフネスを示した。
【００４９】
（実施例５）
実施例４で得られた乾燥した高分子複合体を、実施例２と同様に、平衡状態になるまで吸水させた。このときの平衡吸水率は３５．０質量％であった。この平衡吸水率に達した複合体の引っ張り試験を行った結果、弾性率２５．９ｋＰａ、破断強度２４．８ｋＰａ、破断伸び７５３％であった。
【００５０】
（実施例６）
実施例４で得られた高分子複合体を１４００％の長さまで延伸処理することにより、高分子複合体延伸物を得た。この高分子複合体延伸物の引っ張り試験を行ったところ、弾性率１８．９ＭＰａ、破断強度５．５０ＭＰａ、破断伸び７４０％のタフネス、柔軟性のある高分子複合体であった。またその後、５００％迄の繰り返し延伸試験において、高分子複合体延伸物は、ゴム的な伸縮性とタフネスを示した。
【００５１】
（実施例７）
ＭＥＡの重合を５０℃の恒温水槽中で行うこと以外は、実施例１と同様にして、高分子複合体を調製した。得られた固体は、均一な水膨潤性粘土鉱物と重合体との複合体であり、水膨潤性粘土鉱物などの不均一な凝集は観測されなかった。棒状の高分子複合体を実施例１と同様に１００℃で真空乾燥し、棒状で透明な高分子複合体を得た。実施例１と同様に測定したところ、この高分子複合体中の粘土鉱物含有率は１７．１質量％であった。また実施例１と同様にして、棒状の乾燥した高分子複合体の引っ張り試験を行ったところ、弾性率８．９４ＭＰａ、破断強度１．８８ＭＰａ、破断伸び２１２７％のタフネス、柔軟性のある高分子複合体であった。引っ張り試験後の高分子複合体は、ゴム的な伸縮性とタフネスを示した。
【００５２】
（実施例８）
実施例７で得られた高分子複合体を２１００％の長さまで延伸処理することにより、高分子複合体の延伸物を得た。この高分子複合体の延伸物の引っ張り試験を行ったところ、弾性率１８．０ＭＰａ、破断強度４．６８ＭＰａ、破断伸び５４１％のタフネス、柔軟性のある高分子複合体であった。引っ張り試験後の高分子複合体は、ゴム的な伸縮性とタフネスを示した。
【００５３】
（実施例９）
ラポナイトＸＬＧを０．３９６ｇ用いる代わりに、０．５２８ｇを用いること以外は実施例１と同様にして、高分子複合体を調製した。得られた固体は、均一な水膨潤性粘土鉱物と重合体の複合体であり、水膨潤性粘土鉱物などの不均一な凝集は観測されなかった。棒状の高分子複合体を実施例１と同様に１００℃で真空乾燥し棒状の透明な高分子複合体を得た。実施例１と同様に測定したところ、この高分子複合体中の粘土鉱物含有率は２２．９質量％であった。また透過型電子顕微鏡による観察で、１〜１０ｎｍの厚みの粘土層が均一に微細分散しているのが観測された。また実施例１と同様に棒状の乾燥した高分子複合体の引っ張り試験を行ったところ、降伏点及びネッキング現象を示し、弾性率３．２４ＭＰａ、破断強度５．２５ＭＰａ、破断伸び１８５０％のタフネス、柔軟性のある高分子複合体であった。引っ張り試験後の高分子複合体は、ゴム的な伸縮性とタフネスを示した。
【００５４】
（実施例１０）
ラポナイトＸＬＧ０．３９６ｇを０．０１３２ｇに変えた以外は実施例１と同様にして、高分子複合体を調製した。得られた固体は均一な白色であり、水膨潤性粘土鉱物などの不均一な凝集は観測されなかった。棒状の高分子複合体を実施例１と同様に、１００℃の真空乾燥を行い、棒状の透明な高分子複合体を得た。実施例１と同様に測定したところ、この高分子複合体中の粘土鉱物含有率は０．５質量％であった。また実施例１と同様にして、高分子複合体の引っ張り試験を行ったところ、降伏点及びネッキング現象を示し、弾性率２．９５ｋＰａ、破断強度８９．４ｋＰａ、破断伸び２３５％であった。
【００５５】
（実施例１１）
ＭＥＡ２．３ｇを用いる代わりに、ＭＥＡ１．８４ｇとＮ−イソプロピルアクリルアミド（ＮＩＰＡ：興人株式会社製）０．４ｇとの混合物を用いること以外は実施例１と同様にして、高分子複合体を調製した。得られた固体は、均一な水膨潤性粘土鉱物と共重合体からなる高分子複合体であり、水膨潤性粘土鉱物などの不均一な凝集は観測されなかった。得られた棒状の高分子複合体を実施例１と同様に、１００℃で真空乾燥し棒状の透明な高分子複合体を得た。実施例１と同様に測定したところ、この高分子複合体中の粘土鉱物含有率は１８．６質量％であった。また実施例１と同様にして、棒状の乾燥した高分子複合体の引っ張り試験を行ったところ、降伏点やネッキング現象を示し、弾性率４．８１ＭＰａ、破断強度４．５５ＭＰａ、破断伸び７００％のタフネス、柔軟性のある高分子複合体であった。引っ張り試験後の高分子複合体は、ゴム的な伸縮性とタフネスを示した。
【００５６】
（実施例１２）
実施例１１で得られた乾燥した高分子複合体を実施例２と同様に平衡状態になるまで吸水させ、均一で白色の高分子複合体を得た。平衡吸水率は１３５質量％であった。この平衡吸水率に達した高分子複合体の引っ張り試験を行ったところ、降伏点は示さず、弾性率１．８１ｋＰａ、破断強度７２．４ｋＰａ、破断伸び２７００％であった。
【００５７】
（実施例１３）
実施例１１で得られた棒状の高分子複合体を元の長さの５倍まで一軸延伸し、そのまま長さを固定した状態で、２５℃、湿度５０％で７２時間保持して水分を除いた。その後、８０℃で３時間真空乾燥して、高分子複合体の延伸物を調製した。得られた高分子複合体の延伸物は柔らかく、柔軟性、屈曲性に富み、９０度の曲げ変形試験でも折れることはなく、直径１ｍｍの金属棒に巻き付けても破断したり、傷つくことはなかった。さらにこの高分子複合体の延伸物は伸縮性にも優れたゴム状のものであった。この高分子複合体の延伸物の引っ張り試験を行った結果、弾性率３．４ＭＰａ、破断強度１０．４ＭＰａ、破断伸び２８８％であり、引っ張り試験後の高分子複合体は、ゴム的な伸縮性とタフネスを示した。
【００５８】
（実施例１４）
ＭＥＡ２．３ｇを用いる代わりに、ＭＥＡ２．１９ｇとＮＩＰＡ０．１ｇとの混合物を用いること以外は実施例１と同様にして、高分子複合体を調製した。得られた固体は、均一な水膨潤性粘土鉱物と共重合体からなる高分子複合体であり、水膨潤性粘土鉱物などの不均一な凝集は観測されなかった。棒状の高分子複合体を実施例１と同様に、１００℃で真空乾燥し乾燥した透明な棒状の高分子複合体を得た。実施例１と同様に測定したところ、この高分子複合体中の粘土鉱物含有率は１７．２質量％であった。調製後の棒状の高分子複合体の引っ張り試験を行ったところ、降伏点やネッキング現象を示し、弾性率５．１３ＭＰａ、破断強度２．７４ＭＰａ、破断伸び１９２９％であった。
【００５９】
（実施例１５）
実施例１４で得られた乾燥した高分子複合体を実施例２と同様に平衡状態になるまで吸水させた。このときの平衡吸水率は２８５％であった。この平衡吸水率に達したやや透明性のある高分子複合体の引っ張り試験を行ったところ、弾性率２．３ｋＰａ、破断強度３５．０ｋＰａ、破断伸び３２８０％であった。
【００６０】
（実施例１６）
２０℃の恒温室において、平底ガラス容器に、純水２９．５１ｇとテフロン製攪拌子を入れ、攪拌しながら０．９９ｇのラポナイトＸＬＧを加え、無色透明の溶液を調製した。これにＭＥＡ０．９２ｇとＮＩＰＡ０．２ｇを加え、攪拌して無色透明溶液を得た。次にＫＰＳ水溶液０．５ｇとＴＥＭＥＤ８μｌを攪拌しながら加えた。この溶液の一部を底の閉じた内径５．５ｍｍ、長さ１５０ｍｍのガラス管容器３本に移した後、上部に密栓をし、２０℃の恒温水槽中で２０時間静置して重合を行った。残りの水溶液も平底ガラス容器内で２０℃、２０時間静置し、重合を行った。なお、これらの溶液調製から重合までの操作は、全て酸素を遮断した窒素雰囲気下で行った。２０時間後に、平底ガラス容器内、及びガラス管内に均一な円柱状、及び棒状の白色固体（高分子複合体）が水中で生成しており、両容器から注意深く取り出した。得られた固体は、均一な水膨潤性粘土鉱物と共重合体からなる高分子複合体であり、水膨潤性粘土鉱物などの不均一な凝集は観測されなかった。
【００６１】
棒状の高分子複合体を実施例１と同様に、１００℃の真空乾燥を行い、棒状の透明な高分子複合体を得た。実施例１と同様に測定したところ、この高分子複合体中の粘土鉱物含有率は８８．３質量％であった。この棒状の乾燥した高分子複合体の引っ張り試験を行ったところ、弾性率６６．４ＭＰａ、破断強度５．０２ＭＰａ、破断伸び３０．５％を示した。
【００６２】
（実施例１７）
２０℃の恒温室において、平底ガラス容器に、純水１９．０２ｇとテフロン製攪拌子を入れ、攪拌しながら０．３９６ｇのラポナイトＸＬＧを加え、無色透明の溶液を調製した。これにエタノール２．５ｇとＴＨＦ０．２ｇを入れて撹拌後、２−エトキシエチルアクリレート（Ａｌｄｒｉｃｈ　Ｃｈｅｍｉｃａｌ　Ｃｏｍｐａｎｙ，Ｉｎｃ．製）２．５４ｇを加え、攪拌して無色透明溶液を得た。次にＫＰＳ水溶液１．０ｇとＴＥＭＥＤ１６μｌを攪拌しながら加えた。この溶液の一部を底の閉じた内径５．５ｍｍ、長さ１５０ｍｍのガラス管容器３本に移した後、上部に密栓をし、２０℃の恒温水槽中で２０時間静置して重合を行った。
【００６３】
残りの水溶液も平底ガラス容器内で２０℃、２０時間静置し、重合を行った。なお、これらの溶液調製から重合までの操作は、全て酸素を遮断した窒素雰囲気下で行った。２０時間後に、平底ガラス容器内、及びガラス管内に均一な白色の円柱状、及び棒状の固体（高分子複合体）が水中で生成しており、両容器から注意深く取り出した。得られた固体は、均一な水膨潤性粘土鉱物と重合体の高分子複合体であり、水膨潤性粘土鉱物などの不均一な凝集は観測されなかった。棒状の高分子複合体を実施例１と同様に、１００℃の真空乾燥を行ったところ、柔軟で伸縮性のある透明な棒状の高分子複合体が得られた。
【００６４】
（実施例１８）
２−エトキシエチルアクリレートを２．５４ｇ用いる代わりに、２−エトキシエチルメタクリレート（和光純薬工業株式会社製）を２．８０ｇ用いること以外は実施例１１と同様にして、高分子複合体を調製した。得られた固体は、均一白色の水膨潤性粘土鉱物と重合体の高分子複合体であり、水膨潤性粘土鉱物などの不均一な凝集は観測されなかった。棒状の高分子複合体を実施例１と同様に、１００℃で真空乾燥し、柔軟で伸縮性のある棒状の透明な高分子複合体を得た。
【００６５】
（比較例１）
水膨潤性粘土鉱物を用いないこと以外は実施例１と同様にして、２０℃で２０時間重合を行ったところ、白濁した固体の重合物が得られた。この重合物は柔らかいが非常に脆く、またガラスとの付着性が強く、ガラス管及び平底ガラス容器から取り出そうとしたところ、剥離が困難であり、剥離に伴いすぐに破壊された。またガラス管で調製した棒状の重合物を１００℃で真空乾燥して、乾燥した棒状サンプルを得たが、乾燥後もガラスに付着したまま剥離が困難であり、また弱くて容易に破壊されるため、重合物、乾燥物のいずれも引っ張り試験を行うことは出来なかった。
【００６６】
（比較例２）
水膨潤性粘土鉱物を用いないこと、ＭＥＡを添加した後、有機架橋剤をＭＥＡの３モル％添加する以外は実施例１と同様にして、２０℃で２０時間重合を行ってＭＥＡの有機架橋物を得た。有機架橋剤としては、Ｎ，Ｎ’−メチレンビスアクリルアミド（ＢＩＳ）（和光純薬工業株式会社製）をそのまま使用した。その結果、白濁した脆い含水ゲルが得られた。このゲルは柔らかいが非常に脆く、またガラスとの付着性が強く、ガラス管及び平底ガラス容器から取り出そうとしたところ、剥離が困難であり、すぐに破壊された。またガラス管で調製した棒状のゲルを１００℃で真空乾燥して、乾燥した棒状サンプルを得たが、乾燥後もガラスに付着したまま剥離が困難であり、また弱くて容易に破壊され、含水ゲル、乾燥物のいずれも引っ張り試験を行うことは出来なかった。
【００６７】
【発明の効果】
本発明の高分子複合体は、広い範囲の粘土鉱物含有率において、水膨潤性粘土鉱物が均一に分散し、特に高い濃度の粘土鉱物を含む場合でも、水膨潤性粘土鉱物の微細分散性に優れ、良好な延伸性と優れた強度と弾性率などの力学物性を有する。また、本発明の高分子複合体は大気中で安定して用いられる他、水中でも優れた力学物性を示す特徴を有する。更に該高分子複合体の延伸物は、更に優れた柔軟性や屈曲性を有し可逆的伸縮性を有する材料として利用可能である。
【００６８】
【図面の簡単な説明】
【図１】実施例１で得られた高分子複合体の引っ張り試験における荷重と伸びの関係を示す図である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a polymer composite in which an organic polymer and a clay mineral form a three-dimensional network, a stretched product thereof, and a method for producing the polymer composite.
[0002]
[Prior art]
As a polymer composite material obtained by compounding an organic polymer and an inorganic material, an organic polymer filled with talc, calcium carbonate, or the like in addition to glass fiber, carbon fiber, or the like has been known for a long time. In recent years, by dispersing and compounding nanometer-scale inorganic components in an organic polymer and combining them, excellent mechanical properties and thermal properties have been improved, which has attracted attention as an organic / inorganic nanocomposite material. I have.
[0003]
Here, as the inorganic component, a metal oxide synthesized using a sol-gel reaction or a clay mineral that can be separated into layers is mainly used (for example, see Non-Patent Documents 1 and 2). .).
[0004]
Among them, those containing a clay mineral as an inorganic component are effective in improving mechanical properties and gas shielding properties due to the large aspect ratio of the layered clay. In such a composite (nanocomposite) of a clay mineral and an organic polymer, it is important to finely disperse the clay layer in the organic polymer and to enhance the interaction between the clay layer and the organic polymer. is there. For this purpose, for example, an organic polymer is modified with maleic anhydride, oxazoline, or the like, or as a clay mineral, it is not an inexpensive but inorganic clay mineral that is difficult to disperse in an organic polymer. Etc. to increase the distance between the layers, to facilitate delamination, and to be easily dispersed in an organic solvent or organic polymer (unprocessed clay is called inorganic clay, but organically treated clay is called ) Is often used.
[0005]
Until now, polymer composites called nanocomposites have been prepared by compounding organic polymers such as polyamide, polystyrene, polypropylene, polyimide, and polyurethane with clay. It was reported that the polymer composite obtained had finely dispersed clay layers with a large aspect ratio, which effectively improved the elastic modulus, heat deformation temperature, gas permeability, and burning rate. I have. (For example, see Non-Patent Document 3.)
[0006]
As the amount of clay mineral contained in such a polymer composite, a high clay mineral content is desired from the viewpoint of performance enhancement, but it is also important that effective performance enhancement is achieved with a lower clay mineral amount. . In the studies so far, usually 0.2 to 5% by mass is used, and a low inorganic content polymer composite of 0.1% by mass or less and a high inorganic content polymer composite exceeding 10% by mass are not used. This is so small that the effect of performance improvement is negligible when the inorganic content is low, while on the other hand, when the inorganic content is high, the viscosity at the time of production greatly increases and the nanoscale fine and Uniform dispersion cannot be achieved, or the moldability of the composite is extremely reduced, so that it cannot be uniformly molded into an arbitrary shape. Further, the composite becomes brittle and the mechanical properties (strength and elongation) are greatly reduced. It is.
[0007]
For this reason, even if it is a polymer composite that can achieve effective performance improvement even if the clay mineral content is low, or even a polymer composite that has a high clay mineral content, it achieves uniform fine dispersion of inorganic components, It has been desired to develop a polymer composite having excellent mechanical properties.
[0008]
[Non-patent document 1]
(K. Haraguchi, @et. Al.) Journal of Material Science (J. Mater. Sci.) 33, 3337-3344, 1998.
[0009]
[Non-patent document 2]
(A. Usuki, et. Al.) Journal of Materials Research (J. Mat. Res.) 8: 1117-1178, 1993
[0010]
[Non-Patent Document 3]
(TJ Pinnavaia and GW Bearl Eds.) "Polymer Clay Nanocomposites", published by Wiley, 2000.
[0011]
[Problems to be solved by the invention]
The problem to be solved by the present invention is that, in a wide range of clay mineral content, a polymer in which clay mineral is uniformly and finely dispersed in an organic polymer and exhibits excellent stretchability and mechanical properties such as strength and elastic modulus. An object of the present invention is to provide a composite, a stretched product thereof, and a method for producing the polymer composite.
[0012]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a polymer of (meth) acrylic acid ester or at least one of (meth) acrylamide and N-substituted (meth) acrylamide and (meth) acrylamide An organic polymer (A) comprising a copolymer with an acrylate ester and a water-swellable clay mineral (B) form a three-dimensional network. It has been found that the mechanical properties such as elongation and strength are remarkably improved as compared with a polymer or a copolymer containing no clay mineral, and the present invention has been completed.
[0013]
That is, the present invention relates to a polymer of (meth) acrylic ester (a), or at least one kind of (meth) acrylamide and N-substituted (meth) acrylamide (b) and (meth) acrylic ester (a). And a water-swellable clay mineral (B) formed into a three-dimensional network, and the polymer composite is stretched. A stretched product of a polymer composite, characterized by being obtained by:
[0014]
Further, the present invention provides a method for producing a (meth) acrylic acid ester in the presence of a water-swellable clay mineral (B) dissolved or uniformly dispersed in water or a mixed solvent of water and an organic solvent and a polymerization initiator or a catalyst. A method for producing a polymer composite characterized by polymerizing (a), and polymerization initiation with a water-swellable clay mineral (B) dissolved or uniformly dispersed in water or a mixed solvent of water and an organic solvent Polymer composite, characterized by copolymerizing (meth) acrylamide and at least one kind of N-substituted (meth) acrylamide (b) and (meth) acrylate (a) in the presence of an agent or a catalyst. A method for producing a body is provided.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
The polymer composite of the present invention comprises a polymer of (meth) acrylic ester or a copolymer of (meth) acrylamide and at least one of N-substituted (meth) acrylamide and (meth) acrylic ester. The organic polymer (A) and the water-swellable clay mineral (B) form a three-dimensional network, and the layered and exfoliable water-swellable clay mineral is uniformly contained in the organic polymer in a wide concentration range and stretched. It shows excellent mechanical properties such as flexibility and flexibility.
[0016]
The (meth) acrylic ester, (meth) acrylamide, and N-substituted (meth) acrylamide used in the present invention are preferably soluble in water or a mixed solvent of water and an organic solvent. On the other hand, the organic polymer (A) obtained by polymerizing or copolymerizing these does not necessarily have to be hydrophilic, has more hydrophobic properties, and is stable in water without being dissolved or excessively swollen in water. Are preferably present. Further, in order to change the balance between hydrophilicity and hydrophobicity of the polymer complex and to enhance the interaction with other components, a hydrophilic group, an ionic group and / or a hydrophobic group may be added as necessary. Can be introduced into the polymer or copolymer by pressure.
[0017]
Examples of the (meth) acrylate (a) include methoxyethyl acrylate, ethoxyethyl acrylate, methoxyethyl methacrylate, and ethoxyethyl methacrylate. The polymer of the (meth) acrylate (a) of the present invention includes a polymer of a single monomer selected from these (meth) acrylates or a copolymer of a plurality of monomers.
[0018]
The (meth) acrylamide and the N-substituted (meth) acrylamide are (meth) acrylamide and an alkyl (meth) acrylamide having an alkyl group of 1 or more carbon atoms. Specifically, N-methylacrylamide, N-ethyl Acrylamide, N-cyclopropylacrylamide, N-isopropylacrylamide, N, N-dimethylacrylamide, N-methyl-N-ethylacrylamide, N-methyl-N-isopropylacrylamide, N-methyl-N-n-propylacrylamide, N , N-diethylacrylamide, N-ethyl-N-isopropylacrylamide, N-ethyl-Nn-propylacrylamide, N-acryloylpyrrolidin, N-acryloylpiperidin, N-acryloylmorpholine, N-acryloyl Methyl homopiperazine, N- acryloyl methyl piperazine or N- methyl methacrylamide.
[0019]
When the organic polymer (A) is composed of a copolymer of at least one kind of (meth) acrylamide and N-substituted (meth) acrylamide (b) and (meth) acrylate (a), the copolymer is used. The ratio of (b) to (a) is preferably 0.5 or less, more preferably 0.5 or less in terms of molar ratio, so that the resulting polymer composite has high flexibility at room temperature and low equilibrium water content in water. Is 0.25 or less.
[0020]
The glass transition temperature of the organic polymer (A) is not necessarily limited, and a wide range can be used. However, from the viewpoint of workability, stretchability at room temperature and stretchability, the organic polymer (A) has a glass transition temperature. The temperature is preferably 100 ° C or lower, more preferably 30 ° C or lower, and particularly preferably 0 ° C or lower.
[0021]
As the water-swellable clay mineral (B), a swellable clay mineral that can be separated into layers is used, preferably a clay mineral that swells and can be uniformly dispersed in water or a mixed solution of water and an organic solvent, particularly preferably. An inorganic clay mineral that can be uniformly dispersed in water at a molecular (single-layer) or near-molecular level is used. Specifically, as the water-swellable clay mineral, water-swellable smectite and water-swellable mica are used, and more specifically, water-swellable hectorite containing sodium as an interlayer ion, water-swellable montmorillonite, and water-swellable clay mineral. Swellable saponite, water-swellable synthetic mica, and the like.
[0022]
The polymer composite of the present invention comprises a water-swellable clay mineral (B) dissolved or uniformly dispersed in water or a mixed solvent of water and an organic solvent, and (meth) acrylic acid in the presence of a polymerization initiator or a catalyst. The acid ester (a) is polymerized or dissolved in water or a mixed solvent of water and an organic solvent or uniformly dispersed in the presence of a water-swellable clay mineral (B) and a polymerization initiator or a catalyst. It is obtained by copolymerizing at least one kind of (meth) acrylamide and N-substituted (meth) acrylamide (b) and (meth) acrylic acid ester (a).
[0023]
For example, one or more (meth) acrylic acid esters (a) or (meth) may be added to an aqueous solution in which the water-swellable clay mineral (B) is uniformly finely dispersed in water or a mixed solvent containing water and an organic solvent. A) a mixture of at least one of acrylamide and N-substituted (meth) acrylamide (b) and the (meth) acrylate (a) is added and dissolved, and then an initiator and / or a catalyst are added. Then, the polymer composite of the present invention is obtained by in-situ radical polymerization in the coexistence of the water-swellable clay mineral (B) by a method such as irradiation with an electron beam or heating.
[0024]
As the initiator and catalyst to be used, known radical polymerization initiators and catalysts can be appropriately selected and used. Preferably, those having water dispersibility and being uniformly contained in the whole system are preferably used. Specifically, as a polymerization initiator, a water-soluble peroxide such as potassium peroxodisulfate or ammonium peroxodisulfate, or a water-soluble azo compound such as VA-044, V-50, or V-501 (Wako Pure Chemical Industries, Ltd.) Other than Fe)²⁺And a mixture of hydrogen peroxide and the like.
[0025]
As a catalyst, a tertiary amine compound such as N, N, N ', N'-tetramethylethylenediamine is preferably used. The polymerization temperature is, for example, 0 ° C. to 100 ° C. in accordance with the type of the polymerization catalyst or the initiator. The polymerization time can also be carried out between several tens of seconds and several tens of hours.
[0026]
In the polymer composite of the present invention, the organic polymer (A) and the water-swellable clay mineral (B) interact to form a three-dimensional network. The interaction may be any one or more of an ionic bond, a hydrogen bond, a hydrophobic bond, a coordination bond, a covalent bond, and the like as long as an effective three-dimensional network can be formed. As long as the formation of the three-dimensional network is not hindered or promoted, other polymerizable organic molecules and the like are used in combination with the polymer component constituting the organic polymer (A), or the obtained polymer composite is obtained. Various organic or inorganic functional molecules or particles may be added for the purpose of imparting functionality to the polymer.
[0027]
In the present invention, it is preferable that the three-dimensional network formation of the polymer composite is performed with a water-swellable clay mineral, and the three-dimensional network is formed only with the water-swellable clay mineral without using any ordinary organic crosslinking agent. Is particularly preferred. When an organic cross-linking agent is used, the resulting composite is a material having low mechanical properties such as stretchability and strength.
[0028]
In the polymer composite of the present invention, the mass ratio of the water-swellable clay mineral (B) to the organic polymer (A) is preferably 0.003 to 3, more preferably 0.005 to 2, and particularly preferably. Is 0.01 to 1. If the mass ratio is less than 0.003, the mechanical properties tend to be insufficient as a polymer composite, and if it exceeds 3, uniform fine dispersion of the clay mineral tends to be difficult.
[0029]
Regarding the polymer composite of the present invention, the dried product is uniform and transparent regardless of the content of the water-swellable clay mineral, and no aggregation of the water-swellable clay mineral is observed. The final content of the water-swellable clay mineral is measured by thermal mass spectrometry (TGA), and the fine dispersibility is measured by transmission electron microscope (TEM) observation. The polymer composite of the present invention was confirmed by TGA that the entire amount of the water-swellable clay mineral used was contained in the polymer composite, and a layered clay layer having a thickness of 1 to several nanometers was nanometer-sized. It is confirmed by TEM that the particles are uniformly dispersed on the scale.
[0030]
The polymer composite of the present invention, despite not adding any commonly used organic cross-linking agent, has excellent mechanical properties, especially because it shows high stretchability and stretchability, it was finely dispersed with the organic polymer. It is concluded that the water-swellable clay minerals interact to form a three-dimensional network. On the other hand, the three-dimensional network formed by adding a linear polymer containing no water-swellable clay mineral and an organic cross-linking agent was compared with the polymer composite of the present invention, as shown in Comparative Examples. It shows very low mechanical properties. This suggests that the polymer composite of the present invention forms an unprecedented effective three-dimensional network. Specifically, since the clay layer uniformly distributed works effectively as a polyfunctional crosslinking agent, the distance between the crosslinking points is long and is controlled uniformly, and the polymer between the crosslinking points is the distance between the crosslinking points. Is long, it is presumed to have a structure close to a free chain. By forming a three-dimensional network comprising such an organic polymer and a water-swellable clay mineral, extremely large stretchability and excellent breaking strength are realized.
[0031]
The formation of such a three-dimensional network structure is achieved not only by fine dispersion of a water-swellable clay mineral by observation with a transmission electron microscope, but also by achieving excellent stretchability and high breaking strength shown below, It was also confirmed by measuring the glass transition temperature near the free chain of the organic polymer between the clay mineral layers.
[0032]
The polymer composite of the present invention exhibits excellent mechanical properties. For example, the polymer composite exhibits elongation at break of 1000% to 3000%, and a polymer composite having a large elongation at break of 3000% or more can be obtained. Further, the polymer composite of the present invention exhibits a very high breaking strength as compared with an organic crosslinked polymer or a linear polymer. In addition, by stretching the obtained polymer composite to 100% or more and 100% to 1500%, a stretched polymer composite having higher flexibility and excellent stretchability can be obtained.
[0033]
The unstretched polymer composites of the present invention often exhibit high initial modulus and yield point and necking phenomena and excellent stretchability. On the other hand, a stretched product of the polymer composite of the present invention obtained by stretching the stretched product exhibits excellent stretchability and reversible recovery, and shows good stretchability in a repeated stretching test. The stretching of the polymer composite of the present invention can be performed at a temperature equal to or higher than the glass transition temperature of the organic polymer (A) by a conventional method such as compression, rolling, and extrusion in addition to uniaxial stretching and biaxial stretching. .
[0034]
The polymer composite of the present invention exhibits excellent mechanical properties not only in a dry state but also in a state where moisture is absorbed in a dried sample. The moisture absorption rate varies depending on the composition of the polymer composite, and is not necessarily limited.However, the smaller the moisture absorption rate of the polymer composite, the more stable the mechanical properties in air with different humidity. Is preferably 100% by mass or less, more preferably 70% by mass or less, particularly preferably 30% by mass or less in an atmosphere at a temperature of 25 ° C. and a humidity of 55%. It is.
[0035]
Further, the polymer composite of the present invention exhibits excellent mechanical properties even in a water atmosphere. The equilibrium water absorption of the polymer composite of the present invention in water can also be variously changed depending on the composition of the polymer composite, and is not necessarily limited, but the smaller the equilibrium water absorption, the more stable mechanical properties in water. In order to show, it is preferable that the equilibrium water absorption in water is 500% by mass or less, more preferably 300% by mass or less, and particularly preferably 100% by mass or less.
[0036]
The polymer composite of the present invention can be formed into various shapes such as a columnar shape, a rod shape, a film shape, and a thread shape, and is a material for artificial organs such as an artificial dialyzer, a heart-lung machine, and an artificial blood vessel having excellent biocompatibility and flexibility. It is used as a therapeutic material for catheters and the like, and as various industrial materials having excellent elasticity.
[0037]
【Example】
Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples described below.
[0038]
(Example 1)
Water swellable clay minerals are [Mg_5.34Li_0.66Si₈O₂₀(OH)₄] Na⁺ _0.66Water-swellable synthetic hectorite (trade name: Laponite XLG, manufactured by Nippon Silica Co., Ltd.) having the following composition: As the acrylate derivative, 2-methoxyethyl acrylate (MEA) (manufactured by Wako Pure Chemical Industries, Ltd.) was used. The MEA was used after removing the polymerization inhibitor using a silica gel column (manufactured by Merck).
As the polymerization initiator, potassium peroxodisulfate (KPS: manufactured by Kanto Chemical Co., Ltd.) is dissolved in pure water deoxygenated at a ratio of KPS / water = 0.40 / 20 (g / g) and used as an aqueous solution. did. As the catalyst, N, N, N ', N'-tetramethylethylenediamine (TEMED: manufactured by Wako Pure Chemical Industries, Ltd.) was used. All pure water was used after sufficient bubbling of high-purity nitrogen beforehand to remove the contained oxygen.
[0039]
In a constant temperature room at 20 ° C., 19.02 g of pure water and a stirrer made of Teflon were put in a flat bottom glass container, and 0.396 g of Laponite XLG was added with stirring to prepare a colorless and transparent solution. 2.3 g of MEA was added thereto and stirred to obtain a colorless and transparent solution. Next, 1.0 g of a KPS aqueous solution and 16 μl of TEMED were added with stirring. A part of this solution was transferred to three glass tube containers having a closed bottom with an inner diameter of 5.5 mm and a length of 150 mm, which were then capped at the top and allowed to stand in a constant temperature water bath at 20 ° C. for 20 hours to carry out polymerization. went.
[0040]
The remaining aqueous solution was allowed to stand at 20 ° C. for 20 hours in a flat-bottomed glass container to perform polymerization. The operations from the solution preparation to the polymerization were all performed in a nitrogen atmosphere in which oxygen was cut off. After 20 hours, uniform columnar and rod-like solids (polymer composite) were liberated in water in the flat-bottomed glass container and the glass tube to form.
[0041]
Non-uniform aggregation due to a water-swellable clay mineral or the like was not observed in the obtained polymer composite, and the polymer composite was obtained as a uniform white solid. By vacuum drying at 100 ° C. until the mass became constant, a transparent polymer composite was obtained. The polymer polymerization yield calculated from the dry mass was 99.5% by mass. The moisture content when the dried polymer composite was left at 25 ° C. and 50% humidity for 5 days was 4.9% by mass. After drying the polymer composite, a thermal mass analysis up to 600 ° C. (TG-DTA220, manufactured by Seiko Instruments Inc .: temperature rise: 10 ° C./min under flowing air) was performed to determine the clay content. The clay content (inorganic clay / polymer composite) was 17.1% by mass, which almost coincided with the calculated value from the polymerization solution composition. In the measurement of the Fourier transform infrared absorption spectrum (FT-IR) by the KBr method, characteristic peaks of poly (2-methoxyethyl acrylate) (PMEA) and the water-swellable clay mineral were confirmed.
[0042]
After embedding the dried polymer composite in an epoxy resin, an ultrathin section having a thickness of about 50 mm was prepared and observed with a transmission electron microscope (using JEM-200CX manufactured by JEOL Ltd.). It was observed that the layered clay having a thickness of ~ several nm was finely and uniformly dispersed. From the above results, the solid obtained in this example is a polymer composite comprising a water-swellable clay mineral and PMEA, the clay mineral content is 17.1% by mass, and the water-swellable clay is It became clear that the mineral was finely dispersed uniformly. This polymer composite was transparent and exhibited flexibility without breaking even when bent at 90 ° or more at room temperature.
[0043]
The dynamic viscoelasticity of the dried rod-shaped polymer composite was measured using a DMA-200 manufactured by Seiko Denshi Kogyo Co., Ltd. at a measurement frequency of 1 Hz and a temperature rise of 2 ° C./min. The glass transition temperature (Tg: the temperature indicated by the maximum value of tan δ) was shown in ° C. Further, at a temperature lower than Tg, a high elastic modulus was exhibited, and at a temperature higher than Tg, a stable elastic modulus in a rubber region was exhibited over a wide temperature range.
[0044]
On the other hand, a dried rod-shaped polymer composite (having a cross-sectional area of 3.40 cm²) Was attached to a tensile tester (AGS-H, a desktop universal tester manufactured by Shimadzu Corporation) without slipping at the chuck portion, and a tensile test was performed at a distance between scores of 20 mm and a pulling speed of 100 mm / min. FIG. 1 shows the results of the above. The vertical axis in FIG. 1 shows the load (N) and the horizontal axis shows the elongation (%). A clear yield point and a subsequent necking phenomenon were observed in the initial stage of stretching, and the modulus of elasticity was 15.2 MPa, the breaking strength was 1.88 MPa, and the breaking elongation was 2017%. use). After the tensile test, the polymer composite exhibited rubber-like elasticity and toughness. In particular, the elongation showed an instantaneous recovery by removing stress, and recovered to the original length of 117.4%.
[0045]
From the above results, the obtained polymer composite has excellent mechanical properties including high stretchability and flexibility, despite being a high inorganic-containing composite of 17.1% by mass. Is evident. In addition, such excellent mechanical properties, rubber-like elasticity without using any organic crosslinking agent, and fine dispersibility of water-swellable clay mineral, glass transition temperature of the polymer, the present invention It was concluded that the organic polymer (A) and the water-swellable clay mineral (B) formed a three-dimensional network in the polymer composite of (1).
[0046]
(Example 2)
After weighing the dried polymer composite obtained in Example 1, the mixture was allowed to stand in water at 20 ° C. until the mass was equilibrated, and the equilibrium water absorption was measured. As a result, the equilibrium water absorption (water absorption / mass of dry polymer composite) was 28.2% by mass. This polymer composite was a uniform white solid, and was subjected to a tensile test in the same manner as in Example 1. As a result, the polymer composite had an elastic modulus of 54.8 kPa, a breaking strength of 25.3 kPa, and a breaking elongation of 1856%. It was revealed that the body similarly exhibited excellent mechanical properties such as stretchability in water.
[0047]
(Example 3)
The polymer composite obtained in Example 1 was uniaxially stretched to 5 times the original length, and kept at 25 ° C. and 50% humidity for 72 hours while keeping the length fixed. Then, it was vacuum-dried at 80 ° C. for 3 hours to prepare a stretched polymer composite. The stretched product of the obtained polymer composite is soft, rich in flexibility and flexibility, does not break even in a 90 ° bending deformation test, and does not break or be damaged even when wound around a metal rod having a diameter of 1 mm. Was. Further, the stretched product of this polymer composite showed reversible rubber-like deformation and excellent stretchability in a subsequent repeated stretching test. As a result of performing a tensile test on the stretched product in the same manner as in Example 1, the elastic modulus was 124 kPa, the breaking strength was 1.74 MPa, and the breaking elongation was 2310%. In addition, the elongation showed an elasticity that recovers instantaneously by removing the stress, and recovered to 120% of the original length.
[0048]
(Example 4)
A polymer composite was prepared in the same manner as in Example 1 except that the polymerization of MEA was carried out in a constant temperature water bath at 5 ° C. The obtained solid was a complex of a uniform water-swellable clay mineral and a polymer, and non-uniform aggregation of the water-swellable clay mineral and the like was not observed. The rod-shaped polymer composite was vacuum-dried at 100 ° C. in the same manner as in Example 1 to obtain a rod-shaped transparent polymer composite. When measured in the same manner as in Example 1, the content of clay mineral in this polymer composite was 17.1% by mass. Further, a tensile test of the rod-shaped dried polymer composite was performed in the same manner as in Example 1. The tensile test showed a yield point and a necking phenomenon. The elastic modulus was 11.5 MPa, the breaking strength was 2.13 MPa, and the breaking elongation was 1465%. The polymer composite was tough and flexible. After the tensile test, the polymer composite exhibited rubber-like elasticity and toughness.
[0049]
(Example 5)
The dried polymer composite obtained in Example 4 was allowed to absorb water until it reached an equilibrium state as in Example 2. At this time, the equilibrium water absorption was 35.0% by mass. As a result of a tensile test of the composite having reached the equilibrium water absorption, the composite was found to have an elastic modulus of 25.9 kPa, a breaking strength of 24.8 kPa, and a breaking elongation of 753%.
[0050]
(Example 6)
By stretching the polymer composite obtained in Example 4 to a length of 1400%, a stretched polymer composite was obtained. The stretched polymer composite was subjected to a tensile test. As a result, the stretched polymer composite was tough with a modulus of 18.9 MPa, a breaking strength of 5.50 MPa, an elongation at break of 740%, and a flexible polymer composite. Thereafter, in a repeated stretching test up to 500%, the stretched polymer composite showed rubbery elasticity and toughness.
[0051]
(Example 7)
A polymer composite was prepared in the same manner as in Example 1 except that the polymerization of MEA was performed in a constant temperature water bath at 50 ° C. The obtained solid was a complex of a uniform water-swellable clay mineral and a polymer, and non-uniform aggregation of the water-swellable clay mineral and the like was not observed. The rod-shaped polymer composite was vacuum dried at 100 ° C. in the same manner as in Example 1 to obtain a rod-shaped transparent polymer composite. When measured in the same manner as in Example 1, the content of clay mineral in this polymer composite was 17.1% by mass. Further, a tensile test of the dried polymer composite rod was conducted in the same manner as in Example 1. As a result, a toughness having a modulus of elasticity of 8.94 MPa, a breaking strength of 1.88 MPa, a breaking elongation of 2127%, and a flexible polymer were obtained. It was a complex. After the tensile test, the polymer composite exhibited rubber-like elasticity and toughness.
[0052]
(Example 8)
The polymer composite obtained in Example 7 was stretched to a length of 2100% to obtain a stretched polymer composite. A tensile test of a stretched product of this polymer composite revealed that the polymer composite had a modulus of elasticity of 18.0 MPa, a breaking strength of 4.68 MPa, a toughness of breaking elongation of 541%, and flexibility. After the tensile test, the polymer composite exhibited rubber-like elasticity and toughness.
[0053]
(Example 9)
A polymer composite was prepared in the same manner as in Example 1 except that 0.528 g of Laponite XLG was used instead of 0.396 g of Laponite XLG. The obtained solid was a uniform composite of a water-swellable clay mineral and a polymer, and non-uniform aggregation of the water-swellable clay mineral and the like was not observed. The rod-shaped polymer composite was vacuum-dried at 100 ° C. in the same manner as in Example 1 to obtain a rod-shaped transparent polymer composite. When measured in the same manner as in Example 1, the content of clay mineral in this polymer composite was 22.9% by mass. Observation with a transmission electron microscope revealed that the clay layer having a thickness of 1 to 10 nm was uniformly and finely dispersed. Further, a tensile test of the rod-shaped dried polymer composite was carried out in the same manner as in Example 1. As a result, it showed a yield point and a necking phenomenon, a modulus of elasticity of 3.24 MPa, a breaking strength of 5.25 MPa, and a toughness of breaking elongation of 1850%. It was a flexible polymer composite. After the tensile test, the polymer composite exhibited rubber-like elasticity and toughness.
[0054]
(Example 10)
A polymer composite was prepared in the same manner as in Example 1, except that 0.396 g of Laponite XLG was changed to 0.0132 g. The obtained solid was uniform white, and non-uniform aggregation of the water-swellable clay mineral or the like was not observed. The rod-shaped polymer composite was dried in a vacuum at 100 ° C. in the same manner as in Example 1 to obtain a rod-shaped transparent polymer composite. When measured in the same manner as in Example 1, the content of clay mineral in this polymer composite was 0.5% by mass. A tensile test of the polymer composite was performed in the same manner as in Example 1. As a result, the polymer composite showed a yield point and a necking phenomenon, and had an elastic modulus of 2.95 kPa, a breaking strength of 89.4 kPa, and a breaking elongation of 235%.
[0055]
(Example 11)
A polymer composite was prepared in the same manner as in Example 1 except that instead of using 2.3 g of MEA, a mixture of 1.84 g of MEA and 0.4 g of N-isopropylacrylamide (NIPA: manufactured by Kojin Co., Ltd.) was used. did. The obtained solid was a polymer composite comprising a uniform water-swellable clay mineral and a copolymer, and non-uniform aggregation of the water-swellable clay mineral and the like was not observed. The obtained rod-shaped polymer composite was vacuum-dried at 100 ° C. in the same manner as in Example 1 to obtain a rod-shaped transparent polymer composite. When measured in the same manner as in Example 1, the content of clay mineral in this polymer composite was 18.6% by mass. Further, a tensile test was performed on the rod-shaped dried polymer composite in the same manner as in Example 1. The tensile test showed a yield point and a necking phenomenon. The elastic modulus was 4.81 MPa, the breaking strength was 4.55 MPa, and the breaking elongation was 700%. The polymer composite was tough and flexible. After the tensile test, the polymer composite exhibited rubber-like elasticity and toughness.
[0056]
(Example 12)
The dried polymer composite obtained in Example 11 was allowed to absorb water until it reached an equilibrium state in the same manner as in Example 2 to obtain a uniform, white polymer composite. The equilibrium water absorption was 135% by mass. When a tensile test was performed on the polymer composite having reached the equilibrium water absorption, no yield point was shown, and the elastic modulus was 1.81 kPa, the breaking strength was 72.4 kPa, and the breaking elongation was 2700%.
[0057]
(Example 13)
The rod-shaped polymer composite obtained in Example 11 was uniaxially stretched to 5 times the original length, and the length was fixed as it was, and kept at 25 ° C. and 50% humidity for 72 hours to remove water. Was. Then, it was vacuum-dried at 80 ° C. for 3 hours to prepare a stretched polymer composite. The stretched product of the obtained polymer composite is soft, rich in flexibility and flexibility, does not break even in a 90 ° bending deformation test, and does not break or be damaged even when wound around a metal rod having a diameter of 1 mm. Was. Further, the stretched product of the polymer composite was a rubbery material having excellent elasticity. The stretched product of this polymer composite was subjected to a tensile test. As a result, the elastic modulus was 3.4 MPa, the breaking strength was 10.4 MPa, and the breaking elongation was 288%. And showed toughness.
[0058]
(Example 14)
A polymer composite was prepared in the same manner as in Example 1 except that instead of using 2.3 g of MEA, a mixture of 2.19 g of MEA and 0.1 g of NIPA was used. The obtained solid was a polymer composite comprising a uniform water-swellable clay mineral and a copolymer, and non-uniform aggregation of the water-swellable clay mineral and the like was not observed. The rod-shaped polymer composite was vacuum-dried at 100 ° C. in the same manner as in Example 1 to obtain a dried, transparent rod-shaped polymer composite. When measured in the same manner as in Example 1, the content of clay mineral in this polymer composite was 17.2% by mass. A tensile test of the prepared rod-shaped polymer composite showed a yield point and a necking phenomenon. The elastic modulus was 5.13 MPa, the breaking strength was 2.74 MPa, and the breaking elongation was 1929%.
[0059]
(Example 15)
The dried polymer composite obtained in Example 14 was allowed to absorb water until it reached an equilibrium state as in Example 2. At this time, the equilibrium water absorption was 285%. A tensile test of a slightly transparent polymer composite which reached this equilibrium water absorption showed a modulus of elasticity of 2.3 kPa, a breaking strength of 35.0 kPa, and a breaking elongation of 3280%.
[0060]
(Example 16)
In a 20 ° C. constant temperature room, 29.51 g of pure water and a Teflon stirrer were placed in a flat-bottomed glass container, and 0.99 g of Laponite XLG was added with stirring to prepare a colorless and transparent solution. 0.92 g of MEA and 0.2 g of NIPA were added thereto and stirred to obtain a colorless and transparent solution. Next, 0.5 g of a KPS aqueous solution and 8 μl of TEMED were added with stirring. A part of this solution was transferred to three glass tube containers having a closed bottom with an inner diameter of 5.5 mm and a length of 150 mm, which were then capped at the top and allowed to stand in a constant temperature water bath at 20 ° C. for 20 hours to carry out polymerization. went. The remaining aqueous solution was allowed to stand at 20 ° C. for 20 hours in a flat-bottomed glass container to perform polymerization. The operations from the solution preparation to the polymerization were all performed in a nitrogen atmosphere in which oxygen was cut off. After 20 hours, uniform columnar and rod-like white solids (polymer composites) were formed in the flat-bottomed glass container and the glass tube in water, and were carefully removed from both containers. The obtained solid was a polymer composite comprising a uniform water-swellable clay mineral and a copolymer, and non-uniform aggregation of the water-swellable clay mineral and the like was not observed.
[0061]
The rod-shaped polymer composite was dried in a vacuum at 100 ° C. in the same manner as in Example 1 to obtain a rod-shaped transparent polymer composite. When measured in the same manner as in Example 1, the content of clay mineral in this polymer composite was 88.3% by mass. When a tensile test was performed on the rod-shaped dried polymer composite, it showed an elastic modulus of 66.4 MPa, a breaking strength of 5.02 MPa, and a breaking elongation of 30.5%.
[0062]
(Example 17)
In a constant temperature room at 20 ° C., 19.02 g of pure water and a stirrer made of Teflon were put in a flat bottom glass container, and 0.396 g of Laponite XLG was added with stirring to prepare a colorless and transparent solution. 2.5 g of ethanol and 0.2 g of THF were added thereto and stirred, and then 2.54 g of 2-ethoxyethyl acrylate (manufactured by Aldrich Chemical Company, Inc.) was added, followed by stirring to obtain a colorless and transparent solution. Next, 1.0 g of a KPS aqueous solution and 16 μl of TEMED were added with stirring. A part of this solution was transferred to three glass tube containers having a closed bottom with an inner diameter of 5.5 mm and a length of 150 mm, which were then capped at the top and allowed to stand in a constant temperature water bath at 20 ° C. for 20 hours to carry out polymerization. went.
[0063]
The remaining aqueous solution was allowed to stand at 20 ° C. for 20 hours in a flat-bottomed glass container to perform polymerization. The operations from the solution preparation to the polymerization were all performed in a nitrogen atmosphere in which oxygen was cut off. Twenty hours later, uniform white columnar and rod-like solids (polymer composites) were formed in the flat bottom glass container and the glass tube in water, and were carefully removed from both containers. The obtained solid was a polymer composite of a uniform water-swellable clay mineral and a polymer, and non-uniform aggregation of the water-swellable clay mineral and the like was not observed. The rod-shaped polymer composite was dried in a vacuum at 100 ° C. in the same manner as in Example 1 to obtain a flexible, stretchable, transparent rod-shaped polymer composite.
[0064]
(Example 18)
A polymer composite was prepared in the same manner as in Example 11 except that 2.80 g of 2-ethoxyethyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of using 2.54 g of 2-ethoxyethyl acrylate. . The obtained solid was a polymer composite of a uniform white water-swellable clay mineral and a polymer, and non-uniform aggregation of the water-swellable clay mineral and the like was not observed. The rod-shaped polymer composite was vacuum-dried at 100 ° C. in the same manner as in Example 1 to obtain a flexible and stretchable rod-shaped transparent polymer composite.
[0065]
(Comparative Example 1)
Polymerization was carried out at 20 ° C. for 20 hours in the same manner as in Example 1 except that the water-swellable clay mineral was not used, whereby a cloudy solid polymer was obtained. This polymer was soft but very brittle, and had a strong adhesion to glass. When the polymer was taken out of a glass tube or a flat-bottomed glass container, peeling was difficult, and the polymer was destroyed immediately upon peeling. In addition, a rod-shaped polymer prepared in a glass tube was vacuum-dried at 100 ° C. to obtain a dried rod-shaped sample. However, even after drying, it is difficult to peel off while adhering to the glass, and it is weak and easily broken. Therefore, neither the polymer nor the dried product could be subjected to a tensile test.
[0066]
(Comparative Example 2)
Polymerization was carried out at 20 ° C. for 20 hours in the same manner as in Example 1 except that a water-swellable clay mineral was not used and that an organic crosslinking agent was added at 3 mol% of MEA after MEA was added. I got something. As the organic crosslinking agent, N, N'-methylenebisacrylamide (BIS) (manufactured by Wako Pure Chemical Industries, Ltd.) was used as it was. As a result, a cloudy brittle hydrogel was obtained. This gel was soft but very brittle, and had a strong adhesion to glass. When the gel was taken out of a glass tube and a flat-bottomed glass container, it was difficult to peel off and was immediately destroyed. The rod-shaped gel prepared in a glass tube was vacuum-dried at 100 ° C. to obtain a dried rod-shaped sample. However, even after drying, it was difficult to peel off while still attached to the glass, and it was weak and easily broken, Neither the gel nor the dried product could be subjected to a tensile test.
[0067]
【The invention's effect】
In the polymer composite of the present invention, in a wide range of clay mineral content, the water-swellable clay mineral is uniformly dispersed, and even when a high concentration of clay mineral is contained, the water-swellable clay mineral has a fine dispersibility. Excellent mechanical properties such as good stretchability and excellent strength and elastic modulus. In addition, the polymer composite of the present invention is used stably in the air, and has a characteristic of exhibiting excellent mechanical properties in water. Further, the stretched product of the polymer composite can be used as a material having more excellent flexibility and flexibility and having reversible stretchability.
[0068]
[Brief description of the drawings]
FIG. 1 is a diagram showing the relationship between load and elongation in a tensile test of a polymer composite obtained in Example 1.

Claims

（メタ）アクリル酸エステル（ａ）の重合体、または（メタ）アクリルアミドとＮ−置換（メタ）アクリルアミドの少なくとも１種（ｂ）と（メタ）アクリル酸エステル（ａ）との共重合体からなる有機高分子（Ａ）と、水膨潤性粘土鉱物（Ｂ）とが三次元網目を形成してなることを特徴とする高分子複合体。It consists of a polymer of (meth) acrylic ester (a) or a copolymer of (meth) acrylamide and at least one kind of N-substituted (meth) acrylamide (b) and (meth) acrylic ester (a). A polymer composite, wherein the organic polymer (A) and the water-swellable clay mineral (B) form a three-dimensional network.

前記有機高分子（Ａ）のガラス転移温度が１００℃以下である請求項１に記載の高分子複合体。The polymer composite according to claim 1, wherein the organic polymer (A) has a glass transition temperature of 100 ° C or lower.

前記高分子複合体の水膨潤性粘土鉱物（Ｂ）／有機高分子（Ａ）の質量比が０．００３〜３である請求項１に記載の高分子複合体。The polymer composite according to claim 1, wherein the mass ratio of the water-swellable clay mineral (B) / organic polymer (A) in the polymer composite is 0.003 to 3.

前記（メタ）アクリル酸エステル（ａ）、（メタ）アクリルアミドまたはＮ−置換（メタ）アクリルアミド（ｂ）が、水または水と有機溶媒との混合溶媒に可溶である請求項１に記載の高分子複合体。2. The method according to claim 1, wherein the (meth) acrylic acid ester (a), (meth) acrylamide or N-substituted (meth) acrylamide (b) is soluble in water or a mixed solvent of water and an organic solvent. Molecular complex.

前記（メタ）アクリル酸エステル（ａ）が、メトキシエチルアクリレート、エトキシエチルアクリレート、メトキシエチルメタクリレートまたはエトキシエチルメタクリレートからなる群から選ばれる１種以上である請求項１に記載の高分子複合体。The polymer composite according to claim 1, wherein the (meth) acrylic acid ester (a) is at least one selected from the group consisting of methoxyethyl acrylate, ethoxyethyl acrylate, methoxyethyl methacrylate, and ethoxyethyl methacrylate.

前記有機高分子（Ａ）が（メタ）アクリルアミドとＮ−置換（メタ）アクリルアミドの少なくとも１種（ｂ）と（メタ）アクリル酸エステル（ａ）との共重合体からなり、前記共重合体の（ａ）に対する（ｂ）のモル比が０．５以下である請求項１に記載の高分子複合体。The organic polymer (A) is composed of a copolymer of at least one kind of (meth) acrylamide and N-substituted (meth) acrylamide (b) and (meth) acrylate (a); The polymer composite according to claim 1, wherein the molar ratio of (b) to (a) is 0.5 or less.

水または水と有機溶媒との混合溶媒中に溶解または均一に分散させた水膨潤性粘土鉱物（Ｂ）と重合開始剤または触媒の存在下に（メタ）アクリル酸エステル（ａ）を重合させることを特徴とする高分子複合体の製造方法。Polymerizing a (meth) acrylate (a) in the presence of a polymerization initiator or a catalyst and a water-swellable clay mineral (B) dissolved or uniformly dispersed in water or a mixed solvent of water and an organic solvent. A method for producing a polymer composite, comprising:

水または水と有機溶媒との混合溶媒中に溶解または均一に分散させた水膨潤性粘土鉱物（Ｂ）と重合開始剤または触媒の存在下に（メタ）アクリルアミドとＮ−置換（メタ）アクリルアミドの少なくとも１種（ｂ）と（メタ）アクリル酸エステル（ａ）とを共重合させることを特徴とする高分子複合体の製造方法。Water-swellable clay mineral (B) dissolved or uniformly dispersed in water or a mixed solvent of water and an organic solvent and (meth) acrylamide and N-substituted (meth) acrylamide in the presence of a polymerization initiator or a catalyst. A method for producing a polymer composite, comprising copolymerizing at least one kind (b) and a (meth) acrylate (a).

請求項１〜６のいずれか１つに記載の高分子複合体を延伸して得られることを特徴とする高分子複合体の延伸物。A stretched product of the polymer composite obtained by stretching the polymer composite according to any one of claims 1 to 6.