JP2004124051A

JP2004124051A - New dendrimer and ion-conductive polymer electrolyte having the same

Info

Publication number: JP2004124051A
Application number: JP2003144548A
Authority: JP
Inventors: Akira Hirao; 平尾　明; Kenji Sugiyama; 杉山　賢次; Kiyoshi Kawamura; 河村　潔
Original assignee: Nippon Soda Co Ltd
Current assignee: Nippon Soda Co Ltd
Priority date: 2002-05-22
Filing date: 2003-05-22
Publication date: 2004-04-22
Anticipated expiration: 2023-05-22
Also published as: JP4139735B2

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a new polymer which has sufficient ion conductivity at room temperature without containing a solvent. <P>SOLUTION: A dendrimer has a carbon skeleton represented by formula (I-1) or (I-2) (wherein, m and n in formula (I-1) or (I-2) denote each independently an integer of 1 or more) and has, on a branched chain, a polymer chain containing a polar portion capable of forming a complex with an ion species or a polar portion capable of solvating an ion species. In formulae (I-1) and (I-2) only a skeleton of carbons is represented, at least one functional group selected from the group consisting of a hydrogen atom, a halogen atom, an organic group and an organic group connected with a metallic bond is bound to each carbon atom or a multiple bond is formed with an adjacent atom so that each carbon atom has four bonds. An ion-conductive polymer electrolyte containing these is also provided. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、新規なデンドリマーに関し、さらにそれらを用いた電気化学デバイス、特に電池材料として好適に用いられるイオン伝導性ポリマー電解質に関する。
【０００２】
【従来の技術】
イオン伝導性ポリマーは、ポリ（エチレンオキサイド）−アルカリ金属塩複合体のイオン伝導性が報告されて以来注目されている。特に、高エネルギー密度のリチウム電池の固体電解質成分として使用可能である。ポリマー型電解質は、従来の極性の非プロトン性有機液体からなる電解質に比較して、安全性、電解質の漏れ防止、腐食の低減、温度安定性、力学的特性、操作性等において向上が見られる。たとえば、デンドリマー構造を有するポリマーとリチウム無機塩とのポリマー電解質が提案されている。（特許文献１を参照）
【０００３】
【特許文献１】
特開平８−６９８１７号公報
【０００４】
【発明が解決しようとする課題】
しかし該ポリマー電解質は、溶媒を含んだ状態でしか満足するイオン伝導性が得られておらず、溶媒を含まない固体電解質として十分な性能が得られていないのが現状であり、イオン伝導性と高温作動時の耐熱性、安全性などの面から限界に至っている。
【０００５】
本発明は、溶媒を含まない状態でも室温で十分なイオン伝導性を有する新規ポリマーを提供することを目的とする。
【０００６】
【課題を解決しようとする手段】
本発明者らは、上記課題を解決すべく鋭意検討した結果、式（Ｉ−１）または式（Ｉ−２）で表される炭素骨格および水素結合性極性基を含有するポリマー鎖を分岐鎖に有する新規なデンドリマーとリチウム塩の複合体が、優れたイオン伝導性を示すことを見出し本発明を完成するに至った。
【０００７】
すなわち、本発明は、
（１）式（Ｉ−１）または式（Ｉ−２）
【０００８】
【化５】

【０００９】
（式中、ｍ、およびｎは、それぞれ独立に１以上の整数を表す。但し、式（Ｉ−１）及び式（Ｉ−２）は、炭素骨格のみを表記しており各炭素原子上に結合手が４となるように、水素原子、ハロゲン原子、有機基、および金属結合を介した有機基からなる群から選ばれる少なくとも１つの官能基が結合し、または隣接原子と多重結合を形成するものとする。）で表される炭素骨格およびイオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分を少なくとも１以上有するポリマー鎖を分岐鎖に有することを特徴とするデンドリマーに関し、
（２）分岐鎖の１つに式（ＩＩ）
【００１０】
【化６】

【００１１】
（式中、Ｒ_１は、水素原子、または、置換基を有していてもよいＣ１〜Ｃ５アルキル基を表し、Ｘは、置換基を有していてもよいアリール基、置換基を有していてもよいヘテロアリール基、Ｃ１〜Ｃ２０炭化水素オキシカルボニル基、ニトリル基、Ｎ，Ｎ−ジ置換カルボキサミド基、置換基を有していてもよいビニル基、置換基を有していてもよいエチニル基を表す。）で表す繰り返し単位を有することを特徴とする（１）に記載のデンドリマー、
（３）イオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分が、酸素、窒素、およびイオウからなる群から選ばれるヘテロ原子種を含有する極性部分であることを特徴とする（１）または（２）に記載のデンドリマー、
（４）イオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分を含有するポリマー鎖が、式（ＩＩＩ）
【００１２】
【化７】

【００１３】
（式中、Ｒ_２、Ｒ_３は、それぞれ独立に、水素原子、または置換基を有していてもよいＣ１〜Ｃ５アルキル基を表し、ｋは、２〜５のいずれかの整数を表し、Ｒ_２同士、Ｒ_３同士は、同一または相異なっていてもよい。）で表す繰り返し単位を有するポリマー鎖であることを特徴とする（１）〜（３）いずれかに記載のデンドリマー、
（５）式（Ｉ−１）で表される炭素骨格が式（ＩＶ−１）、式（Ｉ−２）で表される炭素骨格が式（ＩＶ−２）
【００１４】
【化８】

【００１５】
（式中、Ｒ_４は、有機基を表し、ｐおよびｑは、それぞれ独立に１以上の整数を表す。但し、式（ＩＶ−１）及び式（ＩＶ−２）は、炭素骨格のみを表記しており各炭素原子上に結合手が４となるように、水素原子、ハロゲン原子、または有機基および金属結合を介した有機基からなる群から選ばれる少なくとも１つの官能基が結合し、または隣接原子と多重結合を形成しているものとする。）で表わされる繰り返し単位を含有する炭素骨格であることを特徴とする（１）〜（４）のいずれかに記載のデンドリマー、
（６）最終世代に、イオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分を含有するポリマー鎖を有することを特徴とする（１）〜（５）のいずれかに記載のデンドリマー、
（７）重量平均分子量（Ｍｗ）と数平均分子量（Ｍｎ）の比（Ｍｗ／Ｍｎ）が、１．０１〜２．５０であることを特徴とする（１）〜（６）のいずれかに記載のデンドリマー、
（８）数平均分子量が、５，０００〜２０，０００，０００の範囲であることを特徴とする（１）〜（７）のいずれかに記載のデンドリマーに関し、さらに
（９）少なくとも１種の正に荷電したイオン種と（１）〜（８）のいずれかに記載のデンドリマーとの複合体を有することを特徴とするイオン伝導性ポリマー電解質に関する。
【００１６】
【発明の実施の形態】
本発明のデンドリマーは、式（Ｉ−１）または式（Ｉ−２）で表される炭素骨格およびイオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分を少なくとも１以上有するポリマー鎖を分岐鎖に有することを特徴とする。このようなデンドリマーとして、特に、式（ＩＶ−１）または式（ＩＶ−２）で表わされる繰り返し単位を分岐鎖に含有するデンドリマーを好ましく例示することができる。
【００１７】
式（ＩＶ−１）または式（ＩＶ−２）で表わされる繰り返し単位中、Ｒ_４は、有機基を表し、ｐおよびｑは、それぞれ独立に１以上の整数を表す。Ｒ_４として具体的には、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｓ−ブチル基、ｔ−ブチル基、ｎ−ペンチル基、ｎ−ヘキシル基、シクロヘキシル基、フェニル基、ベンジル基、ビニル基、アリル基、エチニル基、プロパルギル基等を例示することができる。また、これらは、適当な炭素原子上に置換基を有していてもよく、そのような置換基として、ハロゲン原子、アルコキシ基、アルキルチオ基、エステル基、アシル基等を例示することができる。また、ｐおよびｑは、それぞれ独立に１以上の整数であれば特に制限されないが、１〜５のいずれかの整数が好ましい。
【００１８】
式（Ｉ−１）または式（Ｉ−２）で表される炭素骨格が、式（ＩＶ−１）または式（ＩＶ−２）で表わされる炭素骨格の各炭素原子上には、結合手が４となるように水素原子、クロル原子、フッ素原子等のハロゲン原子、メチル基、エチル基、フェニル基等の炭化水素基に代表される有機基、トリメチルシリル基、ｔ−ブチルジメチルシリル基に代表される金属結合を介した有機基によって置換されるか、または隣接炭素原子と多重結合を形成しうる。
具体的には、下式で表せる繰り返し単位を例示することができる。
【００１９】
【化９】

【００２０】
また、式（ＩＶ−１）または式（ＩＶ−２）で表わされる繰り返し単位を含有するポリマー鎖は、必要に応じて、２種以上の繰り返し単位を含んでいても構わない。
【００２１】
本発明のデンドリマーは、分岐鎖の一つに式（ＩＩ）で表される繰り返し単位を含有するポリマー鎖を含むデンドリマーを好適に例示することができる。式（ＩＩ）で表わされる繰り返し単位中、Ｒ_１は、水素原子、Ｃ１〜Ｃ５アルキル基を表し、Ｘは、置換基を有していてもよいアリール基、置換基を有していてよいヘテロアリール基、Ｃ１〜Ｃ２０炭化水素オキシカルボニル基、ニトリル基、Ｎ，Ｎ−ジ置換カルボキサミド基、置換基を有していてもよいビニル基、置換基を有していてもよいエチニル基を表す。
【００２２】
Ｒ_１として具体的には、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｓ−ブチル基、ｔ−ブチル基、ｎ−ペンチル基、ビニル基、アリル基、エチニル基、プロパルギル基等を例示することができる。また、これらは、適当な炭素原子上に置換基を有していてもよく、そのような置換基として、ハロゲン原子、アルコキシ基、アルキルチオ基、エステル基、アシル基等を例示することができる。
【００２３】
また、Ｘとして具体的には、フェニル基、４−クロロフェニル基、４−メトキシフェニル基、３，４−ジメチルフェニル基等の置換基を有していてもよいアリール基、２−ピリジル基、４−ピリジル基、６−メチル−２−ピリジル基等の置換基を有していてもよいヘテロアリール基、メトキシカルボニル基、エトキシカルボニル基、ｎ−プロポキシカルボニル基、イソプロポキシカルボニル基、ｎ−ブトキシカルボニル基、ｔ−ブトキシカルボニル基等のアルコキシカルボニル基、ニトリル基、Ｎ，Ｎ−ジメチルカルボキサミド基等のＮ，Ｎ−ジ置換カルボキサイド基、ビニル基、２−メチル−２−ビニル基等の置換基を有していてもよいビニル基、エチニル基、２−メチルエチニル基の置換基を有していてもよいエチニル基を例示することができる。
また、本発明のデンドリマーは、イオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分を含有するポリマー鎖を分岐鎖に有することを特徴とする。このようなイオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分として酸素、窒素、およびイオウからなる群から選択されるヘテロ原子種含む官能基を好ましく例示することができる。特に、式（ＩＩＩ）で表す繰り返し単位を有するポリマー鎖を好ましく例示することができる。
【００２４】
式（ＩＩＩ）で表わされる繰り返し単位中、Ｒ_２及びＲ_３は、それぞれ独立に、水素原子、または置換基を有していてもよいＣ１〜Ｃ５アルキル基を表し、ｎは、２以上の整数を表し、Ｒ_２同士、Ｒ_３同士は、同一または相異なっていてもよい。Ｒ_２及びＲ_３として具体的には、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｓ−ブチル基、ｔ−ブチル基、ｎ−ペンチル基等を例示することができる。また、これらは、適当な炭素原子上に置換基を有していてもよく、そのような置換基として、ハロゲン原子、アルコキシ基、アルキルチオ基、エステル基、アシル基等を例示することができる。ｋは１〜５のいずれかの整数を表す。
【００２５】
イオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分を含有するポリマー鎖として具体的には、ポリエチレンオキサイド、ポリプロピレンオキサイド、ポリブチレンオキサイド、ポリブチレンイミン、ポリエピクロロヒドリン、ポリエチレンチオキサイド、ポリエプロピレンチオキサイド、ポリブチレンチオキサイド、アクリロイル誘導体化（アルキレンオキサイド）、ポリシロキサンアクリレート、ポリホスファゼン等を好ましく例示することができる。
【００２６】
本発明のデンドリマーは、上記したイオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分を含有するポリマー鎖を分岐鎖の一部に有することを特徴とするが、イオン伝導性ポリマー電解質への使用等を考慮した場合、デンドリマー最終世代に該ポリマー鎖を有するのが好ましい。
本発明のデンドリマーの数平均分子量は５，０００〜２０，０００，０００の範囲が好ましく重量平均分子量（Ｍｗ）と数平均分子量（Ｍｎ）の比（Ｍｗ／Ｍｎ）が、１．０１〜２．５０さらに１．０１〜１．５０の範囲であるのが好ましい。またイオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分を含有するポリマー鎖の数平均分子量は１５０〜１０，０００の範囲が好ましく、特に１５０〜５，０００、さらに１５０〜２，０００の範囲が好ましい。
本発明のデンドリマーの製造方法としていくつか考えられるが、例えば、下記に示す製造方法を例示することができる。
▲１▼まず、アニオン重合開始剤の存在下、式（Ｖ）で表される化合物の単独重合、または、前記化合物と共重合可能な化合物と共重合させたアニオン末端と、式（ＶＩ）で表される化合物を反応させ、ポリマー鎖末端に分岐可能な部位を導入する。（式１）
【００２７】
【化１０】

【００２８】
式（Ｖ）または式（ＶＩ）中、Ｒ_１は、それぞれ独立に水素原子、または、Ｃ１〜Ｃ６アルキル基を表し、Ｘは、置換基を有していてもよいアリール基、置換基を有していてよいヘテロアリール基、Ｃ１〜Ｃ２０炭化水素オキシカルボニル基、ニトリル基、Ｎ，Ｎ−ジ置換カルボキサミド基、置換基を有していてもよいビニル基、置換基を有していてもよいエチニル基を表し、Ｙは、アニオン末端に対して安定であり、アニオン末端と反応性を有する官能基に変換可能な官能基を表す。
【００２９】
【化１１】

【００３０】
▲２▼▲１▼で調整されたポリマー（ＶＩＩ）のＹをアニオン末端と反応性を有するＺに変換した後、式（ＶＩ）より誘導されるアニオンと反応性させて、分岐鎖のふえたポリマー鎖（ＶＩＩＩ）を得る。（式２）
【００３１】
【化１２】

【００３２】
▲３▼同様の反応を繰り返すことにより、任意の数の末端Ｙを有するデンドリマーを得ることができる。
▲４▼さらに末端ＹをＺに変換した後、式（ＩＸ）
【００３３】
【化１３】

【００３４】
（式中、Ｒ_５及びＲ_６は、それぞれ独立に置換基を有していてもよいＣ１〜Ｃ５アルキル基を表す。）で表されるアルキレンオキシドをアニオン重合させたアニオン末端と反応させ最終世代にポリアルキレンオキシドを導入したデンドリマーを得ることができる。
本発明のイオン伝導性ポリマー電解質は、少なくとも１種の正に荷電したイオン種と上記したデンドリマーとの複合体を有することを特徴とする。正に荷電したイオン種として具体的には、Ｌｉ^＋、Ｎａ^＋、Ｋ^＋、Ｒ_４Ｎ^＋、Ｍｇ^２＋、Ｃａ^２＋等のカチオン種を例示することができ、そのようなカチオン種を有する化合物としてＩ⁻、ＣＦ_３ＳＯ_３ ⁻、ＣｌＯ_４ ⁻、ＡｓＦ_４ ⁻、ＰＦ_６ ⁻、ＢＦ_４ ⁻、ＳＣＮ⁻、メチド、ビスハロアシル、スルホニルイミド、またはＲＣＯ_２ ⁻等（Ｒは、アルキル基、アルケニル基、アルキニル基、芳香族炭化水素基等を示す。）のアニオン種と塩を形成する化合物を例示することができ、正に荷電したイオン種と特に分岐鎖中、イオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分を含有するポリマー鎖部位を中心に複合体を形成する。
【００３５】
以下、実施例を用いて本発明を詳細に説明するが、本発明の範囲は実施例に限定されるものではない。
【００３６】
【実施例】
本発明の実施例に使用した試薬および溶媒の精製法について以下に述べる。
【００３７】
使用した溶媒、およびモノマーは、すべて、通常の手順に従って、精製し、窒素雰囲気下、ＣａＨ_２を用いて蒸留した。テトラヒドロフラン（ＴＨＦ）は、さらに高真空ライン（１０^−６Ｔｏｒｒ）でナトリウムナフタレニドから蒸留した。
【００３８】
ｓｅｃ−ブチルリチウム（ｓ−ＢｕＬｉ）は、市販のｓ−ＢｕＬｉのシクロヘキサン（１．３Ｍ；ナカライ社製）を高真空下、ヘプタンで希釈し、小分けしたものを用いた。正確な濃度は、高真空下、ＴＨＦ中−７８℃で１，１−ジフェニルエチレン（ＤＰＥ）との反応により１，１−ジフェニル−３−メチルペンチルリチウムを生成させ、このアニオン特有の赤色が消色するまで標準　ｎ−オクタノール／ＴＨＦを用いて比色滴定により求めた。
［重合操作方法］
アニオン重合は高真空下ブレークシール法を用いた。重合はモノマーを開始剤系に加え所定時間反応した後、メタノールで反応を停止した。
［サイズエクスクルージョンクロマトグラフィー（ＳＥＣ）の測定］
ＵＶ（２５４ｎｍ）及び屈折率検出計を備えたＴＯＳＯＨ−ＨＬＣ−８０２０を用いて測定した。カラムは３種のポリスチレンゲルカラム（ＴＳＫｇｅｌＧ４０００ＨＸＬ、Ｇ３０００ＨＸＬ及びＧ２０００ＨＸＬ）を用いて行った。キャリア溶媒としてはＴＨＦまたはＮ，Ｎ−ジメチルホルムアミドを用い、流速１．０ｍｌ／分で行った。標準試料としてポリスチレンを用い、検量線を作成して、Ｍｎ及びＭｗ／Ｍｎ値を決定した。ＴＳＫ−Ｇ４０００ＨＨＲカラムを備えたＴＯＳＨ−ＨＬＣ−８０２０を用いて、分取を行った。溶媒としてＴＨＦを用い、ポリマー濃度は、サンプルの分子量に応じて、１０〜２０ｗ／ｖ％に調製した。
【００３９】
実施例１
スチレン（Ａ）４．８２ｇ（４６．３ｍｍｏｌ）のＴＨＦ溶液を−７８℃でｓ−ＢｕＬｉ（１．１０ｍｍｏｌ）に添加し−７８℃で１０分間撹拌した。次に、窒素雰囲気下、−７８℃で１，１−ビス（３−ｔ−ブチルジメチルシリロキシメチルフェニル）エテン（Ｂ）０．６１９ｇのＴＨＦ溶液を加え、同温度で０．５時間撹拌した後、メタノールを加えて反応を停止し、反応液を大量のメタノールに加え、析出した結晶をロ過し乾燥させポリマー５．３０ｇを得た。先に得られたポリマーのクロロホルム−アセトニトリル混合溶液にＬｉＢｒ９．５５ｇ及びトリメチルシリルクロライド（ＴＭＳＣｌ）１４．９ｇを３０℃で加え、同温度で２４時間撹拌した。反応液を大量のメタノールに加え、析出したポリマーを濾過し、ＴＨＦ−メタノールを用いて再沈殿させ、ポリマー（Ｃ１）５．１５ｇを得た。窒素雰囲気下、−７８℃で１，１−ビス（３−ｔ−ブチルジメチルシリロキシメチルフェニル）エテン（Ｂ）２．１５ｇのＴＨＦ溶液にｓ−ＢｕＬｉ（１．７９ｍｍｏｌ）を添加し−７８℃で１０分間撹拌した。これにポリマー（Ｃ１）３．５７ｇのＴＨＦ溶液（０．７４５ｍｍｏｌ）に加え、同温度で０．５時間撹拌した。上記と同様の操作を更に２回繰り返し、１７分岐のデンドリマー（Ｄ１１）を得た。更に同様にＬｉＢｒ、ＴＭＳＣｌのクロロホルム−アセトニトリル混合溶液を加え、３０℃で２４時間撹拌した。反応液を大量のメタノールに加え、析出したポリマーを濾過し、ＴＨＦ−メタノールを用いて再沈殿をし、１７分岐で、最外殻にアニオンに対して反応点を有するデンドリマー（Ｄ）（Ｍｗ／Ｍｎ＝１．０４、Ｍｎ＝９６００）を得た。
【００４０】
【化１４】

【００４１】
（式中、太線は、ポリスチレン鎖、・は、分岐鎖の炭素分岐点を表す。）
ＴＨＦ中のジフェニルメチルカリウム（０．３３３ｍｍｏｌ）にエチレンオキサイド１．８３ｇ（４１．５ｍｍｏｌ）を０℃で加え、室温で６時間反応させてポリエチレンオキサイドカリウムを生成させ、ポリエチレンオキサイドカリウム（Ｍｗ＝５６６０、Ｍｗ／Ｍｎ＝１．０２）を得た。さらに、０℃で、上記のように調製したポリマー（Ｄ）１１．６ｍｇ（０．０１２１ｍｍｏｌ）を加え、４０℃で７２時間反応を行い、脱気したメタノールを加えて反応を停止した。大量の水に加えて、析出した結晶を濾過し、目的とするデンドリマー（Ｅ）をほぼ定量的に得た。得られたデンドリマーの重量平均分子量は、８９，５００となり計算値とよく一致した。また、Ｍｗ／Ｍｎの値は、１．０４であった。
【００４２】
【化１５】

【００４３】
（式中、太線は、ポリスチレン鎖、波線は、ポリエチレンオキシド鎖、・は、分岐鎖の炭素分岐点を表す。）
【００４４】
実施例２
実施例１で得られたデンドリマー（Ｅ１）０．２ｇとリチウム　ビス（トリフルオロメチルスルホニル）イミド（ＬｉＴＦＳＩ）０．０６ｇをアルゴン雰囲気下のグローボックス中で、脱水アセトニトリル７ｍｌと脱水メタノール５ｍｌの混合溶媒１２ｍｌを加え、室温で攪拌して透明な溶液とした。この溶液を厚さ３ｍｍのシリコンシート上にキャストし、加熱減圧下で溶媒を留去し、厚さ１２０μｍのデンドリマー（Ｅ１）−Ｌｉ塩複合体の薄膜を得た。この薄膜の３０℃、４０℃、５０℃におけるイオン伝導度を測定した。その結果をまとめて表１に示す。
【００４５】
実施例３
スチレン（Ａ）１０．１ｇ（９６．７ｍｍｏｌ）のＴＨＦ溶液を−７８℃でｓ−ＢｕＬｉ（１．１３ｍｍｏｌ）に添加し−７８℃で１０分間撹拌した。次に、窒素雰囲気下、−７８℃で１，１−ビス（３−ｔ−ブチルジメチルシリロキシメチルフェニル）エテン（Ｂ）０．６３８ｇのＴＨＦ溶液を加え、同温度で０．５時間撹拌した後、メタノールを加えて反応を停止し、反応液を大量のメタノールに加え、析出した結晶をロ過し乾燥させポリマー１０．５ｇを得た。先に得られたポリマーのクロロホルム−アセトニトリル混合溶液にＬｉＢｒ９．６６ｇ及びトリメチルシリルクロライド（ＴＭＳＣｌ）１５．１ｇを３０℃で加え、同温度で２４時間撹拌した。反応液を大量のメタノールに加え、析出したポリマーを濾過し、ＴＨＦ−メタノールを用いて再沈殿させ、ポリマー（Ｃ２）１０．１ｇを得た。窒素雰囲気下、−７８℃で１，１−ビス（３−ｔ−ブチルジメチルシリロキシメチルフェニル）エテン（Ｂ）０．８４６ｇのＴＨＦ溶液にｓ−ＢｕＬｉ（１．５０ｍｍｏｌ）を添加し−７８℃で１０分間撹拌した。これにポリマー（Ｃ２）５．８３ｇのＴＨＦ溶液（０．６２７ｍｍｏｌ）に加え、同温度で０．５時間撹拌した。上記と同様の操作を更に２回繰り返し、１７分岐のデンドリマー（Ｄ２１）を得た。更に同様にＬｉＢｒ、ＴＭＳＣｌのクロロホルム−アセトニトリル混合溶液を加え、３０℃で２４時間撹拌した。反応液を大量のメタノールに加え、析出したポリマーを濾過し、ＴＨＦ−メタノールを用いて再沈殿をし、１７分岐で、最外殻にアニオンに対して反応点を有するデンドリマー（Ｄ２２）（Ｍｗ／Ｍｎ＝１．０４、Ｍｎ＝１４０００）を得た。
【００４６】
ＴＨＦ中のジフェニルメチルカリウム（１．３３ｍｍｏｌ）にエチレンオキサイド１．４２ｇ（３２．２ｍｍｏｌ）を０℃で加え、室温で６時間反応させてポリエチレンオキサイドカリウムを生成させ、ポリエチレンオキサイドカリウム（Ｍｗ＝１２００、Ｍｗ／Ｍｎ＝１．０５）を得た。さらに、０℃で、上記のように調製したポリマー（Ｄ２２）１．９７ｇ（０．０６９３ｍｍｏｌ）を加え、４０℃で７２時間反応を行い、脱気したメタノールを加えて反応を停止した。大量の水に加えて、析出した結晶を濾過し、目的とするデンドリマー（Ｅ２）をほぼ定量的に得た。得られたデンドリマーの重量平均分子量は、３３，９００となり計算値とよく一致した。また、Ｍｗ／Ｍｎの値は、１．０４であった。
【００４７】
実施例４
実施例３で得られたデンドリマー（Ｅ２）０．２ｇと過塩素酸リチウム（ＬｉＣｌＯ_４）０．０１４２ｇを脱水アセトン１．５ｇに加え、室温で攪拌して透明な溶液とした。この溶液をアルミニウム板上にキャストし、加熱減圧下で溶媒を留去し、厚さ１００μｍのデンドリマー（Ｅ２）−Ｌｉ塩複合体の薄膜を得た。この薄膜の３０℃、４０℃、５０℃におけるイオン伝導度を測定した。その結果をまとめて表１に示す。
【００４８】
実施例５
スチレン（Ａ）３．２６ｇ（３１．３ｍｍｏｌ）のＴＨＦ溶液を−７８℃でリチウムナフタレニド（０．６０６ｍｍｏｌ）に添加し−７８℃で１０分間撹拌した。次に、窒素雰囲気下、−７８℃で１，１−ビス（３−ｔ−ブチルジメチルシリロキシメチルフェニル）エテン（Ｂ）０．６８２ｇのＴＨＦ溶液を加え、同温度で０．５時間撹拌した後、メタノールを加えて反応を停止し、反応液を大量のメタノールに加え、析出した結晶をロ過し乾燥させポリマー３．４８ｇを得た。先に得られたポリマーのクロロホルム−アセトニトリル混合溶液にＬｉＢｒ５．１６ｇ及びトリメチルシリルクロライド（ＴＭＳＣｌ）８．０７ｇを３０℃で加え、同温度で２４時間撹拌した。反応液を大量のメタノールに加え、析出したポリマーを濾過し、ＴＨＦ−メタノールを用いて再沈殿させ、ポリマー（Ｃ３）５．０５ｇを得た。窒素雰囲気下、−７８℃で１，１−ビス（３−ｔ−ブチルジメチルシリロキシメチルフェニル）エテン（Ｂ）０．６０４ｇのＴＨＦ溶液にｓ−ＢｕＬｉ（１．０７ｍｍｏｌ）を添加し−７８℃で１０分間撹拌した。これにポリマー（Ｃ３）４．９６ｇのＴＨＦ溶液（０．４４７ｍｍｏｌ）に加え、同温度で０．５時間撹拌した。上記と同様の操作を更に２回繰り返し、ポリスチレン鎖の量末端に１６の分岐鎖を有するデンドリマー（Ｄ３１）を得た。更に同様にＬｉＢｒ、ＴＭＳＣｌの塩化メチレン溶液を加え、３０℃で２４時間撹拌した。反応液を大量のメタノールに加え、析出したポリマーを濾過し、ＴＨＦ−メタノールを用いて再沈殿をし、ポリスチレン鎖両末端に３２分岐で、最外殻にアニオンに対して反応点を有するデンドリマー（Ｄ３２）（Ｍｗ／Ｍｎ＝１．０７、Ｍｎ＝２１０００）を得た。
【００４９】
ＴＨＦ中のジフェニルメチルカリウム（１．５３ｍｍｏｌ）にエチレンオキサイド１．５４ｇ（３４．９ｍｍｏｌ）を０℃で加え、室温で６時間反応させてポリエチレンオキサイドカリウムを生成させ、ポリエチレンオキサイドカリウム（Ｍｗ＝１２００、Ｍｗ／Ｍｎ＝１．０５）を得た。さらに、０℃で、上記のように調製したポリマー（Ｄ３２）０．８４０ｇ（０．０３９８ｍｍｏｌ）を加え、４０℃で７２時間反応を行い、脱気したメタノールを加えて反応を停止した。大量のメタノールに加えて、析出した結晶を濾過し、目的とするデンドリマー（Ｅ３）をほぼ定量的に得た。得られたデンドリマーの重量平均分子量は、５８，３００となり計算値とよく一致した。また、Ｍｗ／Ｍｎの値は、１．０４であった。
【００５０】
実施例６
実施例５で得られたデンドリマー（Ｅ３）０．２ｇと過塩素酸リチウム（ＬｉＣｌＯ_４）０．０１５８ｇを脱水アセトン１．５ｇに加え、室温で攪拌して透明な溶液とした。この溶液をアルミニウム板上にキャストし、加熱減圧下で溶媒を留去し、厚さ１００μｍのデンドリマー（Ｅ３）−Ｌｉ塩複合体の薄膜を得た。この薄膜の３０℃、４０℃、５０℃におけるイオン伝導度を測定した。その結果をまとめて表１に示す。
【００５１】
実施例７
スチレン（Ａ）５．０５ｇ（４８．５ｍｍｏｌ）のＴＨＦ溶液を−７８℃でｓ−ＢｕＬｉ（０．４７４ｍｍｏｌ）に添加し−７８℃で１０分間撹拌した。次に、窒素雰囲気下、−７８℃で１，１−ビス（３−ｔ−ブチルジメチルシリロキシメチルフェニル）エテン（Ｂ）０．２６７ｇのＴＨＦ溶液を加え、同温度で０．５時間撹拌した後、メタノールを加えて反応を停止し、反応液を大量のメタノールに加え、析出した結晶をロ過し乾燥させポリマー５．２０ｇを得た。先に得られたポリマーのクロロホルム−アセトニトリル混合溶液にＬｉＢｒ４．１２ｇ及びトリメチルシリルクロライド（ＴＭＳＣｌ）６．４４ｇを３０℃で加え、同温度で２４時間撹拌した。反応液を大量のメタノールに加え、析出したポリマーを濾過し、ＴＨＦ−メタノールを用いて再沈殿させ、ポリマー（Ｃ４）５．０５ｇを得た。窒素雰囲気下、−７８℃で１，１−ビス（３−ｔ−ブチルジメチルシリロキシメチルフェニル）エテン（Ｂ）０．６０４ｇのＴＨＦ溶液にｓ−ＢｕＬｉ（１．０７ｍｍｏｌ）を添加し−７８℃で１０分間撹拌した。これにポリマー（Ｃ４）４．９６ｇのＴＨＦ溶液（０．４４７ｍｍｏｌ）に加え、同温度で０．５時間撹拌した。上記と同様の操作を更に３回繰り返し、３３分岐のデンドリマー（Ｄ４１）を得た。更に同様にＬｉＢｒ、ＴＭＳＣｌのクロロホルム−アセトニトリル混合溶液を加え、３０℃で２４時間撹拌した。反応液を大量のメタノールに加え、析出したポリマーを濾過し、ＴＨＦ−メタノールを用いて再沈殿をし、３３分岐で、最外殻にアニオンに対して反応点を有するデンドリマー（Ｄ４２）（Ｍｗ／Ｍｎ＝１．０４、Ｍｎ＝１５０００）を得た。
【００５２】
ＴＨＦ中のジフェニルメチルカリウム（３．６５ｍｍｏｌ）にエチレンオキサイド３．８１ｇ（８６．５ｍｍｏｌ）を０℃で加え、室温で６時間反応させてポリエチレンオキサイドカリウムを生成させ、ポリエチレンオキサイドカリウム（Ｍｗ＝１２００、Ｍｗ／Ｍｎ＝１．０５）を得た。さらに、０℃で、上記のように調製したポリマー（Ｄ４２）１．９７ｇ（０．０９２１ｍｍｏｌ）を加え、４０℃で７２時間反応を行い、脱気したメタノールを加えて反応を停止した。大量の水に加えて、析出した結晶を濾過し、目的とするデンドリマー（Ｅ４）をほぼ定量的に得た。得られたデンドリマーの重量平均分子量は、５９，９００となり計算値とよく一致した。また、Ｍｗ／Ｍｎの値は、１．０４であった。
【００５３】
実施例８
実施例７で得られたデンドリマー（Ｅ４）０．２ｇとリチウム　ビス（トリフルオロメチルスルホニル）イミド（ＬｉＴＦＳＩ）０．０４４１ｇ、または過塩素酸リチウム（ＬｉＣｌＯ_４）０．０１６０ｇを脱水アセトン１．５ｇに加え、または０．０７５７ｇをアルゴン雰囲気下のグローボックス中で、脱水アセトン１．５ｇに加え、室温で攪拌して透明な溶液とした。この溶液をアルミニウム板上にキャストし、加熱減圧下で溶媒を留去し、厚さ１００μｍのデンドリマー（Ｅ４）−Ｌｉ塩複合体の薄膜を得た。この薄膜の３０℃、４０℃、５０℃におけるイオン伝導度を測定した。その結果をまとめて表１に示す。
【００５４】
【表１】

【００５５】
【発明の効果】
以上のようにして得られたイオン種と複合体を形成し得る極性部分またはイオン種を溶媒和し得る極性部分を含有するポリマー鎖を分岐鎖に有するデンドリマーは、特に該極性部分にリチウム塩を包含させることにより、室温で良好なイオン伝導性を示し、電池等の電気デバイスの電解質として利用することができ産業上の有用性は高いといえる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to novel dendrimers, and more particularly to an ion conductive polymer electrolyte suitably used as an electrochemical device using the same, particularly as a battery material.
[0002]
[Prior art]
Ion conductive polymers have received attention since the ionic conductivity of poly (ethylene oxide) -alkali metal salt complexes was reported. In particular, it can be used as a solid electrolyte component of a high energy density lithium battery. Compared to conventional electrolytes composed of polar aprotic organic liquids, polymer electrolytes show improvements in safety, prevention of electrolyte leakage, reduction of corrosion, temperature stability, mechanical properties, operability, etc. . For example, a polymer electrolyte of a polymer having a dendrimer structure and a lithium inorganic salt has been proposed. (See Patent Document 1)
[0003]
[Patent Document 1]
JP-A-8-69817
[0004]
[Problems to be solved by the invention]
However, the polymer electrolyte has not achieved satisfactory ionic conductivity only in a state containing a solvent, and at present, sufficient performance has not been obtained as a solid electrolyte containing no solvent. It has reached its limits in terms of heat resistance and safety during high-temperature operation.
[0005]
An object of the present invention is to provide a novel polymer having sufficient ionic conductivity at room temperature even without a solvent.
[0006]
[Means to solve the problem]
The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a polymer chain containing a carbon skeleton and a hydrogen-bonding polar group represented by the formula (I-1) or (I-2) has a branched chain. The present inventors have found that a novel composite of a dendrimer and a lithium salt has excellent ionic conductivity and completed the present invention.
[0007]
That is, the present invention
(1) Formula (I-1) or Formula (I-2)
[0008]
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[0009]
(In the formula, m and n each independently represent an integer of 1 or more. However, in the formulas (I-1) and (I-2), only the carbon skeleton is described, and At least one functional group selected from the group consisting of a hydrogen atom, a halogen atom, an organic group, and an organic group via a metal bond is bonded to form a bond of 4, or forms a multiple bond with an adjacent atom. The polymer has at least one polar portion capable of forming a complex with the carbon skeleton and the ionic species or a polar portion capable of solvating the ionic species in the branched chain. Regarding dendrimers,
(2) Formula (II) as one of the branched chains
[0010]
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[0011]
(Where R₁Represents a hydrogen atom or a C1-C5 alkyl group which may have a substituent, and X represents an aryl group which may have a substituent or a heteroaryl which may have a substituent. And a C1-C20 hydrocarbonoxycarbonyl group, a nitrile group, an N, N-disubstituted carboxamide group, a vinyl group optionally having a substituent, and an ethynyl group optionally having a substituent. The dendrimer according to (1), which has a repeating unit represented by the formula (1):
(3) The polar portion capable of forming a complex with the ionic species or the polar portion capable of solvating the ionic species is a polar portion containing a heteroatom species selected from the group consisting of oxygen, nitrogen, and sulfur. The dendrimer according to (1) or (2),
(4) A polymer chain containing a polar portion capable of forming a complex with an ionic species or a polar portion capable of solvating an ionic species has a formula (III)
[0012]
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[0013]
(Where R₂, R₃Each independently represents a hydrogen atom or a C1 to C5 alkyl group which may have a substituent; k represents an integer of any of 2 to 5;₂Each other, R₃Each may be the same or different. (1) to (3), wherein the dendrimer has a repeating unit represented by the following formula:
(5) The carbon skeleton represented by the formula (I-1) is represented by the formula (IV-1), and the carbon skeleton represented by the formula (I-2) is represented by the formula (IV-2)
[0014]
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[0015]
(Where R₄Represents an organic group, and p and q each independently represent an integer of 1 or more. However, in the formulas (IV-1) and (IV-2), only a carbon skeleton is described, and a hydrogen atom, a halogen atom, an organic group, and a metal are added such that a bond is 4 on each carbon atom. It is assumed that at least one functional group selected from the group consisting of organic groups via a bond is bonded or forms a multiple bond with an adjacent atom. The dendrimer according to any one of (1) to (4), which is a carbon skeleton containing a repeating unit represented by the following formula:
(6) The final generation has a polymer chain containing a polar portion capable of forming a complex with the ionic species or a polar portion capable of solvating the ionic species. The dendrimer according to
(7) The method according to any one of (1) to (6), wherein a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.01 to 2.50. The dendrimer described,
(8) The dendrimer according to any one of (1) to (7), wherein the number average molecular weight is in the range of 5,000 to 20,000,000.
(9) An ion-conductive polymer electrolyte comprising a complex of at least one positively charged ionic species and the dendrimer according to any one of (1) to (8).
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
The dendrimer of the present invention has at least one polar moiety capable of forming a complex with the carbon skeleton and the ionic species represented by the formula (I-1) or (I-2) or at least one polar moiety capable of solvating the ionic species. It is characterized by having the above-mentioned polymer chain in the branched chain. As such a dendrimer, a dendrimer containing a repeating unit represented by the formula (IV-1) or (IV-2) in a branched chain can be preferably exemplified.
[0017]
In the repeating unit represented by the formula (IV-1) or (IV-2), R₄Represents an organic group, and p and q each independently represent an integer of 1 or more. R₄Specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, cyclohexyl Phenyl group, benzyl group, vinyl group, allyl group, ethynyl group, propargyl group and the like. Further, these may have a substituent on an appropriate carbon atom, and examples of such a substituent include a halogen atom, an alkoxy group, an alkylthio group, an ester group, an acyl group and the like. In addition, p and q are not particularly limited as long as they are each independently an integer of 1 or more, and any one of 1 to 5 is preferable.
[0018]
The carbon skeleton represented by the formula (I-1) or (I-2) has a bond on each carbon atom of the carbon skeleton represented by the formula (IV-1) or (IV-2). As represented by 4, a hydrogen atom, a chloro atom, a halogen atom such as a fluorine atom, an organic group represented by a hydrocarbon group such as a methyl group, an ethyl group and a phenyl group, a trimethylsilyl group, and a t-butyldimethylsilyl group are represented. May be substituted by an organic group through a metal bond or form multiple bonds with adjacent carbon atoms.
Specifically, a repeating unit represented by the following formula can be exemplified.
[0019]
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[0020]
Further, the polymer chain containing the repeating unit represented by the formula (IV-1) or (IV-2) may contain two or more kinds of repeating units as necessary.
[0021]
As the dendrimer of the present invention, a dendrimer including a polymer chain containing a repeating unit represented by the formula (II) in one of the branched chains can be preferably exemplified. In the repeating unit represented by the formula (II), R₁Represents a hydrogen atom, a C1-C5 alkyl group, and X represents an aryl group which may have a substituent, a heteroaryl group which may have a substituent, a C1-C20 hydrocarbonoxycarbonyl group, a nitrile. Group, an N, N-disubstituted carboxamide group, a vinyl group which may have a substituent, and an ethynyl group which may have a substituent.
[0022]
R₁Specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, vinyl, allyl, ethynyl And propargyl groups. Further, these may have a substituent on an appropriate carbon atom, and examples of such a substituent include a halogen atom, an alkoxy group, an alkylthio group, an ester group, an acyl group and the like.
[0023]
Specific examples of X include an aryl group which may have a substituent such as a phenyl group, a 4-chlorophenyl group, a 4-methoxyphenyl group, a 3,4-dimethylphenyl group, a 2-pyridyl group, A heteroaryl group which may have a substituent such as -pyridyl group, 6-methyl-2-pyridyl group, a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl Groups, alkoxycarbonyl groups such as t-butoxycarbonyl group, etc., nitrile groups, N, N-disubstituted carboxide groups such as N, N-dimethylcarboxamide group, substituent groups such as vinyl group and 2-methyl-2-vinyl group Examples of the ethynyl group which may have a substituent of a vinyl group, an ethynyl group, and a 2-methylethynyl group which may have It can be.
Further, the dendrimer of the present invention is characterized in that a branched polymer chain contains a polar portion capable of forming a complex with an ionic species or a polar portion capable of solvating an ionic species. Preferred examples of the polar portion capable of forming a complex with such an ionic species or the polar portion capable of solvating the ionic species include a functional group containing a heteroatom species selected from the group consisting of oxygen, nitrogen, and sulfur. it can. Particularly, a polymer chain having a repeating unit represented by the formula (III) can be preferably exemplified.
[0024]
In the repeating unit represented by the formula (III), R₂And R₃Each independently represents a hydrogen atom or a C1 to C5 alkyl group which may have a substituent; n represents an integer of 2 or more;₂Each other, R₃Each may be the same or different. R₂And R₃Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, and an n-pentyl group. Further, these may have a substituent on an appropriate carbon atom, and examples of such a substituent include a halogen atom, an alkoxy group, an alkylthio group, an ester group, an acyl group and the like. k represents an integer of any of 1 to 5.
[0025]
Specific examples of the polymer chain containing a polar portion capable of forming a complex with an ionic species or a polar portion capable of solvating an ionic species include polyethylene oxide, polypropylene oxide, polybutylene oxide, polybutyleneimine, and polyepichlorohydrin. Preferred examples include phosphorus, polyethylene thiooxide, polypropylene thiooxide, polybutylene oxide, acryloyl derivatized (alkylene oxide), polysiloxane acrylate, polyphosphazene, and the like.
[0026]
The dendrimer of the present invention is characterized in that it has a polymer chain containing a polar portion capable of forming a complex with the above ionic species or a polar portion capable of solvating the ionic species in a part of the branched chain. In consideration of use for a conductive polymer electrolyte and the like, it is preferable to have the polymer chain in the final generation of dendrimer.
The number average molecular weight of the dendrimer of the present invention is preferably in the range of 5,000 to 20,000,000, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.01 to 2.0. It is more preferably in the range of 1.01 to 1.50. Further, the number average molecular weight of the polymer chain containing a polar portion capable of forming a complex with the ionic species or a polar portion capable of solvating the ionic species is preferably in the range of 150 to 10,000, particularly preferably 150 to 5,000, and more preferably 150 to 5,000. The range of 150 to 2,000 is preferred.
Several methods for producing the dendrimer of the present invention are conceivable. For example, the following production methods can be exemplified.
{Circle around (1)} First, in the presence of an anionic polymerization initiator, homopolymerization of the compound represented by the formula (V), or an anion end copolymerized with a compound copolymerizable with the compound, and an anion terminal represented by the formula (VI) The compound represented is reacted to introduce a branchable site at the polymer chain end. (Equation 1)
[0027]
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[0028]
In the formula (V) or the formula (VI), R₁Each independently represents a hydrogen atom or a C1 to C6 alkyl group, and X represents an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a C1 to C20 hydrocarbon. Represents an oxycarbonyl group, a nitrile group, an N, N-disubstituted carboxamide group, a vinyl group optionally having a substituent, or an ethynyl group optionally having a substituent; Represents a functional group that is stable and can be converted to a functional group that is reactive with the anion end.
[0029]
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[0030]
(2) After converting Y of the polymer (VII) prepared in (1) into Z having reactivity with the anion terminal, the polymer (VII) was reacted with an anion derived from the formula (VI) to increase the number of branched chains. A polymer chain (VIII) is obtained. (Equation 2)
[0031]
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[0032]
(3) By repeating the same reaction, a dendrimer having an arbitrary number of terminal Y can be obtained.
{Circle around (4)} After further converting the terminal Y into Z, the formula (IX)
[0033]
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[0034]
(Where R₅And R₆Represents a C1 to C5 alkyl group which may have a substituent. The alkylene oxide represented by the formula (1) can be reacted with an anionic terminal obtained by anionic polymerization to obtain a dendrimer having a polyalkylene oxide introduced into the final generation.
The ion-conductive polymer electrolyte of the present invention is characterized by having a complex of at least one positively charged ionic species and the above-mentioned dendrimer. As the positively charged ionic species, specifically, Li⁺, Na⁺, K⁺, R₄N⁺, Mg²⁺, Ca²⁺And the like. Examples of the compound having such a cationic species include I⁻, CF₃SO₃ ⁻, ClO₄ ⁻, AsF₄ ⁻, PF₆ ⁻, BF₄ ⁻, SCN⁻, Methide, bishaloacyl, sulfonylimide, or RCO₂ ⁻(R represents an alkyl group, an alkenyl group, an alkynyl group, an aromatic hydrocarbon group, etc.), and a compound that forms a salt with an anionic species, such as a positively charged ionic species and particularly a branched chain A complex is formed around a polymer chain site containing a polar portion capable of forming a complex with an ionic species or a polar portion capable of solvating an ionic species.
[0035]
Hereinafter, the present invention will be described in detail with reference to examples, but the scope of the present invention is not limited to the examples.
[0036]
【Example】
The method of purifying the reagent and the solvent used in the examples of the present invention will be described below.
[0037]
All solvents and monomers used were purified and CaH under nitrogen atmosphere according to standard procedures.₂Distilled using. Tetrahydrofuran (THF) has been added to the high vacuum line (10^-6(Torr) from sodium naphthalenide.
[0038]
As sec-butyllithium (s-BuLi), commercially available s-BuLi cyclohexane (1.3M; manufactured by Nacalai Co.) was diluted with heptane under a high vacuum, and used in small portions. The precise concentration is that the reaction with 1,1-diphenylethylene (DPE) at -78 ° C. in THF under high vacuum produces 1,1-diphenyl-3-methylpentyllithium, and the red color peculiar to this anion disappears. The color was determined by colorimetric titration using standard Δn-octanol / THF until coloration.
[Polymerization operation method]
For the anionic polymerization, a break seal method under a high vacuum was used. In the polymerization, the monomer was added to the initiator system and reacted for a predetermined time, and then the reaction was stopped with methanol.
[Measurement of size exclusion chromatography (SEC)]
The measurement was performed using TOSOH-HLC-8020 equipped with UV (254 nm) and a refractive index detector. The column was used using three kinds of polystyrene gel columns (TSKgelG4000HXL, G3000HXL and G2000HXL). The reaction was performed at a flow rate of 1.0 ml / min using THF or N, N-dimethylformamide as a carrier solvent. A calibration curve was prepared using polystyrene as a standard sample, and Mn and Mw / Mn values were determined. The fractionation was performed using TOSH-HLC-8020 equipped with a TSK-G4000HHR column. THF was used as a solvent, and the polymer concentration was adjusted to 10 to 20 w / v% according to the molecular weight of the sample.
[0039]
Example 1
A THF solution of 4.82 g (46.3 mmol) of styrene (A) was added to s-BuLi (1.10 mmol) at -78 ° C, and the mixture was stirred at -78 ° C for 10 minutes. Next, in a nitrogen atmosphere, a THF solution of 0.619 g of 1,1-bis (3-t-butyldimethylsilyloxymethylphenyl) ethene (B) was added at −78 ° C., and the mixture was stirred at the same temperature for 0.5 hour. Thereafter, methanol was added to stop the reaction, the reaction solution was added to a large amount of methanol, and the precipitated crystals were filtered and dried to obtain 5.30 g of a polymer. LiBr was added to the chloroform-acetonitrile mixed solution of the polymer obtained above.9.55 g and 14.9 g of trimethylsilyl chloride (TMSCl) were added at 30 ° C., and the mixture was stirred at the same temperature for 24 hours. The reaction solution was added to a large amount of methanol, and the precipitated polymer was filtered and reprecipitated using THF-methanol to obtain 5.15 g of a polymer (C1). Under a nitrogen atmosphere, s-BuLi (1.79 mmol) was added to a THF solution of 2.15 g of 1,1-bis (3-t-butyldimethylsilyloxymethylphenyl) ethene (B) at −78 ° C. at −78 ° C. For 10 minutes. This was added to a THF solution (0.745 mmol) of 3.57 g of the polymer (C1), and the mixture was stirred at the same temperature for 0.5 hour. The same operation as described above was further repeated twice to obtain a 17-branched dendrimer (D11). Further, similarly, a mixed solution of LiBr and TMSCl in chloroform-acetonitrile was added, and the mixture was stirred at 30 ° C. for 24 hours. The reaction solution was added to a large amount of methanol, the precipitated polymer was filtered, reprecipitated using THF-methanol, and a 17-branch dendrimer (D) (Mw / Mn = 1.04, Mn = 9600).
[0040]
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[0041]
(In the formula, the thick line represents a polystyrene chain, and represents the carbon branch point of the branched chain.)
1.83 g (41.5 mmol) of ethylene oxide was added to diphenylmethylpotassium (0.333 mmol) in THF at 0 ° C., and reacted at room temperature for 6 hours to produce potassium polyethylene oxide. The potassium polyethylene oxide (Mw = 5660, (Mw / Mn = 1.02). Further, 11.6 mg (0.0121 mmol) of the polymer (D) prepared as described above was added at 0 ° C., the reaction was performed at 40 ° C. for 72 hours, and degassed methanol was added to stop the reaction. In addition to a large amount of water, the precipitated crystals were filtered to obtain the desired dendrimer (E) almost quantitatively. The weight average molecular weight of the obtained dendrimer was 89,500, which was in good agreement with the calculated value. Further, the value of Mw / Mn was 1.04.
[0042]
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[0043]
(In the formula, a thick line represents a polystyrene chain, a wavy line represents a polyethylene oxide chain, and represents a carbon branch point of a branched chain.)
[0044]
Example 2
0.2 g of the dendrimer (E1) obtained in Example 1 and 0.06 g of lithium bis (trifluoromethylsulfonyl) imide (LiTFSI) were mixed in a glow box under an argon atmosphere in a mixed solvent of 7 ml of dehydrated acetonitrile and 5 ml of dehydrated methanol. 12 ml was added and stirred at room temperature to form a clear solution. This solution was cast on a silicon sheet having a thickness of 3 mm, and the solvent was distilled off under reduced pressure under heating to obtain a thin film of a dendrimer (E1) -Li salt composite having a thickness of 120 μm. The ionic conductivity at 30 ° C., 40 ° C., and 50 ° C. of the thin film was measured. Table 1 summarizes the results.
[0045]
Example 3
A THF solution of 10.1 g (96.7 mmol) of styrene (A) was added to s-BuLi (1.13 mmol) at -78 ° C, and the mixture was stirred at -78 ° C for 10 minutes. Next, a THF solution of 0.638 g of 1,1-bis (3-t-butyldimethylsilyloxymethylphenyl) ethene (B) was added at −78 ° C. under a nitrogen atmosphere, and the mixture was stirred at the same temperature for 0.5 hour. Thereafter, methanol was added to stop the reaction, the reaction solution was added to a large amount of methanol, and the precipitated crystals were filtered and dried to obtain 10.5 g of a polymer. LiBr was added to the chloroform-acetonitrile mixed solution of the polymer obtained above.9.66 g and 15.1 g of trimethylsilyl chloride (TMSCl) were added at 30 ° C., and the mixture was stirred at the same temperature for 24 hours. The reaction solution was added to a large amount of methanol, and the precipitated polymer was filtered and reprecipitated using THF-methanol to obtain 10.1 g of a polymer (C2). Under a nitrogen atmosphere, s-BuLi (1.50 mmol) was added to a THF solution of 0.846 g of 1,1-bis (3-t-butyldimethylsilyloxymethylphenyl) ethene (B) at −78 ° C. at −78 ° C. For 10 minutes. This was added to a THF solution (0.627 mmol) of 5.83 g of the polymer (C2), and the mixture was stirred at the same temperature for 0.5 hour. The same operation as described above was further repeated twice to obtain a 17-branched dendrimer (D21). Further, similarly, a mixed solution of LiBr and TMSCl in chloroform-acetonitrile was added, and the mixture was stirred at 30 ° C. for 24 hours. The reaction solution was added to a large amount of methanol, the precipitated polymer was filtered, reprecipitated using THF-methanol, and a dendrimer (D22) (Mw / Mn = 1.04, Mn = 14000).
[0046]
1.42 g (32.2 mmol) of ethylene oxide was added to diphenylmethylpotassium (1.33 mmol) in THF at 0 ° C., and reacted at room temperature for 6 hours to produce polyethylene oxide potassium, and polyethylene oxide potassium (Mw = 1200, (Mw / Mn = 1.05). Furthermore, 1.97 g (0.0693 mmol) of the polymer (D22) prepared as described above was added at 0 ° C., the reaction was carried out at 40 ° C. for 72 hours, and the reaction was stopped by adding degassed methanol. In addition to a large amount of water, the precipitated crystals were filtered to obtain a target dendrimer (E2) almost quantitatively. The weight average molecular weight of the obtained dendrimer was 33,900, which was in good agreement with the calculated value. Further, the value of Mw / Mn was 1.04.
[0047]
Example 4
0.2 g of the dendrimer (E2) obtained in Example 3 and lithium perchlorate (LiClO₄) 0.0142 g was added to 1.5 g of dehydrated acetone and stirred at room temperature to form a clear solution. This solution was cast on an aluminum plate, and the solvent was distilled off under reduced pressure under heating to obtain a thin film of a dendrimer (E2) -Li salt composite having a thickness of 100 μm. The ionic conductivity at 30 ° C., 40 ° C. and 50 ° C. of this thin film was measured. Table 1 summarizes the results.
[0048]
Example 5
A THF solution of 3.26 g (31.3 mmol) of styrene (A) was added to lithium naphthalenide (0.606 mmol) at -78 ° C, and the mixture was stirred at -78 ° C for 10 minutes. Next, a THF solution of 0.682 g of 1,1-bis (3-t-butyldimethylsilyloxymethylphenyl) ethene (B) was added at −78 ° C. under a nitrogen atmosphere, and the mixture was stirred at the same temperature for 0.5 hour. Thereafter, methanol was added to stop the reaction, the reaction solution was added to a large amount of methanol, and the precipitated crystals were filtered and dried to obtain 3.48 g of a polymer. LiBr was added to the chloroform-acetonitrile mixed solution of the polymer obtained above.5.16 g and 8.07 g of trimethylsilyl chloride (TMSCl) were added at 30 ° C., and the mixture was stirred at the same temperature for 24 hours. The reaction solution was added to a large amount of methanol, and the precipitated polymer was filtered and reprecipitated using THF-methanol to obtain 5.05 g of a polymer (C3). Under a nitrogen atmosphere, s-BuLi (1.07 mmol) was added to a THF solution of 0.604 g of 1,1-bis (3-t-butyldimethylsilyloxymethylphenyl) ethene (B) at −78 ° C. at −78 ° C. For 10 minutes. This was added to a THF solution (0.447 mmol) of 4.96 g of the polymer (C3), and the mixture was stirred at the same temperature for 0.5 hour. The same operation as described above was further repeated twice to obtain a dendrimer (D31) having 16 branched chains at the ends of the polystyrene chains. Further, similarly, a methylene chloride solution of LiBr and TMSCl was added, and the mixture was stirred at 30 ° C. for 24 hours. The reaction solution was added to a large amount of methanol, and the precipitated polymer was filtered and reprecipitated using THF-methanol. D32) (Mw / Mn = 1.07, Mn = 21000) was obtained.
[0049]
1.54 g (34.9 mmol) of ethylene oxide was added to diphenylmethylpotassium (1.53 mmol) in THF at 0 ° C., and reacted at room temperature for 6 hours to produce potassium polyethylene oxide. The potassium polyethylene oxide (Mw = 1200, (Mw / Mn = 1.05). Further, 0.840 g (0.0398 mmol) of the polymer (D32) prepared as described above was added at 0 ° C., the reaction was performed at 40 ° C. for 72 hours, and the reaction was stopped by adding degassed methanol. In addition to a large amount of methanol, the precipitated crystals were filtered to obtain a target dendrimer (E3) almost quantitatively. The weight average molecular weight of the obtained dendrimer was 58,300, which was in good agreement with the calculated value. Further, the value of Mw / Mn was 1.04.
[0050]
Example 6
0.2 g of the dendrimer (E3) obtained in Example 5 and lithium perchlorate (LiClO₄) 0.0158 g was added to 1.5 g of dehydrated acetone and stirred at room temperature to form a clear solution. This solution was cast on an aluminum plate, and the solvent was distilled off under reduced pressure under heating to obtain a thin film of a dendrimer (E3) -Li salt composite having a thickness of 100 μm. The ionic conductivity at 30 ° C., 40 ° C. and 50 ° C. of this thin film was measured. Table 1 summarizes the results.
[0051]
Example 7
A THF solution of 5.05 g (48.5 mmol) of styrene (A) was added to s-BuLi (0.474 mmol) at −78 ° C., and the mixture was stirred at −78 ° C. for 10 minutes. Next, in a nitrogen atmosphere, a THF solution of 0.267 g of 1,1-bis (3-t-butyldimethylsilyloxymethylphenyl) ethene (B) was added at −78 ° C., and the mixture was stirred at the same temperature for 0.5 hour. Thereafter, methanol was added to stop the reaction, the reaction solution was added to a large amount of methanol, and the precipitated crystals were filtered and dried to obtain 5.20 g of a polymer. LiBr was added to the chloroform-acetonitrile mixed solution of the polymer obtained above.4.12 g and trimethylsilyl chloride (TMSCl) 6.44 g were added at 30 ° C., and the mixture was stirred at the same temperature for 24 hours. The reaction solution was added to a large amount of methanol, and the precipitated polymer was filtered and reprecipitated using THF-methanol to obtain 5.05 g of a polymer (C4). Under a nitrogen atmosphere, s-BuLi (1.07 mmol) was added to a THF solution of 0.604 g of 1,1-bis (3-t-butyldimethylsilyloxymethylphenyl) ethene (B) at −78 ° C. at −78 ° C. For 10 minutes. This was added to a THF solution (0.447 mmol) of 4.96 g of the polymer (C4), and the mixture was stirred at the same temperature for 0.5 hour. The same operation as above was repeated three more times to obtain a 33-branched dendrimer (D41). Further, similarly, a mixed solution of LiBr and TMSCl in chloroform-acetonitrile was added, and the mixture was stirred at 30 ° C. for 24 hours. The reaction solution was added to a large amount of methanol, and the precipitated polymer was filtered and reprecipitated using THF-methanol. The dendrimer (D42) having 33 branches and having a reaction point for anions in the outermost shell (Mw / Mn = 1.04, Mn = 15000).
[0052]
3.81 g (86.5 mmol) of ethylene oxide was added to diphenylmethylpotassium (3.65 mmol) in THF at 0 ° C., and reacted at room temperature for 6 hours to produce polyethylene oxide potassium, and polyethylene oxide potassium (Mw = 1200, (Mw / Mn = 1.05). Furthermore, 1.97 g (0.0921 mmol) of the polymer (D42) prepared as described above was added at 0 ° C., the reaction was carried out at 40 ° C. for 72 hours, and degassed methanol was added to stop the reaction. In addition to a large amount of water, the precipitated crystals were filtered to obtain a target dendrimer (E4) almost quantitatively. The weight average molecular weight of the obtained dendrimer was 59,900, which was in good agreement with the calculated value. Further, the value of Mw / Mn was 1.04.
[0053]
Example 8
0.2 g of the dendrimer (E4) obtained in Example 7 and 0.0441 g of lithium bis (trifluoromethylsulfonyl) imide (LiTFSI) or lithium perchlorate (LiClO)₄) 0.0160 g was added to 1.5 g of dehydrated acetone, or 0.0757 g was added to 1.5 g of dehydrated acetone in a glow box under an argon atmosphere, and stirred at room temperature to obtain a clear solution. This solution was cast on an aluminum plate, and the solvent was distilled off under reduced pressure under heating to obtain a thin film of a dendrimer (E4) -Li salt composite having a thickness of 100 µm. The ionic conductivity at 30 ° C., 40 ° C., and 50 ° C. of the thin film was measured. Table 1 summarizes the results.
[0054]
[Table 1]

[0055]
【The invention's effect】
The dendrimer having a polymer chain containing a polar portion capable of forming a complex with the ionic species or a polar portion capable of solvating the ionic species in the branched chain obtained as described above, particularly a lithium salt in the polar portion. By including it, it shows good ionic conductivity at room temperature, and can be used as an electrolyte of an electric device such as a battery, and it can be said that industrial utility is high.

Claims

Formula (I-1) or Formula (I-2)

(In the formula, m and n each independently represent an integer of 1 or more. However, in the formulas (I-1) and (I-2), only the carbon skeleton is described, and At least one functional group selected from the group consisting of a hydrogen atom, a halogen atom, an organic group, and an organic group via a metal bond is bonded to form a bond of 4, or forms a multiple bond with an adjacent atom. The polymer has at least one polar portion capable of forming a complex with the carbon skeleton and the ionic species or a polar portion capable of solvating the ionic species in the branched chain. Dendrimer.

Formula (II) in one of the branched chains

(Wherein, R ₁ represents a hydrogen atom or a C1 to C5 alkyl group optionally having a substituent, and X represents an aryl group optionally having a substituent, Optionally substituted heteroaryl group, C1-C20 hydrocarbonoxycarbonyl group, nitrile group, N, N-disubstituted carboxamide group, optionally substituted vinyl group, optionally substituted group The dendrimer according to claim 1, wherein the dendrimer has a repeating unit represented by the following formula:

The polar portion capable of forming a complex with the ionic species or the polar portion capable of solvating the ionic species is a polar portion containing a heteroatom species selected from the group consisting of oxygen, nitrogen, and sulfur. The dendrimer according to claim 1.

A polymer chain containing a polar moiety capable of forming a complex with an ionic species or a solvable ionic species is represented by the formula (III):

(Wherein, R ₂ and R ₃ each independently represent a hydrogen atom or a C1-C5 alkyl group which may have a substituent, and k represents an integer of any of 2 to 5, R ₂ together, R ₃ each other, dendrimer according to claim 1, characterized in that a polymer chain having a repeating unit represented by the same or different may be different.).

The carbon skeleton represented by the formula (I-1) is represented by the formula (IV-1), and the carbon skeleton represented by the formula (I-2) is represented by the formula (IV-2)

(In the formula, R ₄ represents an organic group, p and q each independently represent an integer of 1 or more, provided that the formulas (IV-1) and (IV-2) represent only a carbon skeleton. And at least one functional group selected from the group consisting of a hydrogen atom, a halogen atom, or an organic group and an organic group via a metal bond is bonded such that the bond is 4 on each carbon atom; or The dendrimer according to any one of claims 1 to 4, wherein the carbon skeleton contains a repeating unit represented by the following formula:

The dendrimer according to any one of claims 1 to 5, wherein the final generation has a polymer chain containing a polar portion capable of forming a complex with the ionic species or a polar portion capable of solvating the ionic species.

The dendrimer according to any one of claims 1 to 6, wherein a ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) is 1.01 to 2.50.

The dendrimer according to any one of claims 1 to 7, wherein the number average molecular weight is in a range of 5,000 to 20,000,000.

An ion-conductive polymer electrolyte comprising a complex of at least one positively charged ionic species and the dendrimer according to claim 1.