JP3658789B2 - Conductive polymer compound aqueous solution, production method thereof, storage method - Google Patents

Description

一般式（ＩＩ）
【化１４】

一般式（ＩＩＩ）
【化１５】

一般式（ＩＶ）
【化１６】

一般式（Ｖ）
【化１７】

および一般式（ＶＩ）
【化１８】

（式中、Ｒ₁ 、Ｒ₂ 、Ｒ₃ およびＲ₄ はそれぞれ独立にＨ、炭素数１乃至２０の直鎖状もしくは分岐状の飽和もしくは不飽和アルキル、アルコキシまたはアルキルエステル基、ハロゲン、ＳＯ₃ ^-Ｍ（但しＲ₁ またはＲ₂ の場合にはＭはＨ⁺ を表わす。）、ニトロ基、シアノ基、１級、２級または３級アミノ基、トリハロメチル基、フェニル基及び置換フェニル基からなる群から選ばれる一価基を表わす。ＭはＮＲ₅ Ｒ₆ Ｒ₇ Ｒ₈ ⁺で表わされる第４級アンモニウムのカチオン、ＰＲ₅ Ｒ₆ Ｒ₇ Ｒ₈ ⁺、ＡｓＲ₅ Ｒ₆ Ｒ₇ Ｒ₈ ⁺で表わされるＶｂ族元素の第４級カチオン、あるいはＮａ⁺ 、Ｌｉ⁺ 、Ｋ⁺ 等のアルカリ金属イオンを表わし、Ｒ₅ 、Ｒ₆ 、Ｒ₇ 、Ｒ₈ はそれぞれ独立にＨ、または炭素数１乃至３０の直鎖状もしくは分岐状の置換もしくは非置換アルキル基、または置換もしくは非置換アリール基を表わし、アルコキシ基、ヒドロキシル基、オキシアルキレン基、チオアルキレン基、アゾ基、アゾベンゼン基、ｐ−ジフェニレンオキシ基のごとき炭素、水素以外の元素を含む基を含むアルキルまたはアリール基であってもよい。Ｒ₁ とＲ₂ 、またはＲ₃ とＲ₄ 、あるいはＲ₅ 、Ｒ₆ 、Ｒ₇ 及びＲ₈ から選ばれる複数の置換基は、互いに任意の位置で結合して、該置換基により置換されている原子を含む飽和または不飽和の環状構造を形成する二価基を少なくとも１つ以上形成してもよい。Ｒ₁ 、Ｒ₂ 、Ｒ₃ 、Ｒ₄ 、Ｒ₅ 、Ｒ₆ 、Ｒ₇ 、Ｒ₈ がアルキル基の場合、またはＲ₁ 、Ｒ₂ 、Ｒ₃ 、Ｒ₄ がアルコキシ基もしくはアルキルエステル基の場合は、その鎖中には、カルボニル、エーテル、エステル、アミド、スルフィド、スルフィニル、スルホニル、イミノなどの結合を任意に含んでもよい。）で示される化学構造の少なくとも一つを繰返し単位として含み且つ主鎖がπ共役系二重結合を有する水溶性導電性高分子化合物を含み、実質的に酸素を含有しない水溶液により達成される。
【００１０】
さらに第２の目的は、前記一般式（Ｉ）〜（ＶＩ）（式中、Ｒ₁ 、Ｒ₂ 、Ｒ₃ 、Ｒ₄ およびＭは前記と同じである。）
で示される化学構造の少なくとも一つを繰返し単位として含み且つ主鎖がπ共役系二重結合を有する水溶性導電性高分子化合物を含む水溶液を、脱酸素処理することを特徴とする導電性高分子化合物水溶液の製造方法により達成される。
【００１１】
第３の目的は、前述の一般式（Ｉ）〜（ＶＩ）（式中、Ｒ₁ 、Ｒ₂ 、Ｒ₃ 、Ｒ₄ およびＭは前記と同じである。）で示される化学構造の少なくとも一つを繰返し単位として含み且つ主鎖がπ共役系二重結合を有する水溶性導電性高分子化合物を含み、実質的に酸素を含有しない水溶液を、酸素遮断状態で保存することを特徴とする導電性高分子化合物水溶液の保存方法により達成される。
【００１２】
本発明において、繰り返し単位として含むとは、必ずしもその単位を連続して含む必要はなく、ランダムコポリマーあるいはブロックコポリマーのように不規則、不連続に含む場合も包含している。
以下本発明を詳細に説明する。
【００１３】
本発明において用いられる主鎖がπ共役系二重結合を有する水溶性導電性高分子化合物とは、前記一般式（Ｉ）乃至（ＶＩ）で示される化学構造の少なくとも一つを繰返し単位として含む水溶性導電性高分子化合物である。該水溶性導電性高分子化合物とは、前記一般式（Ｉ）乃至（ＶＩ）で示される化学構造のいずれか一つを繰返し単位とする単独重合体からなる水溶性導電性高分子であっても、あるいは、該化学構造の少なくとも一つを繰返し単位として重合体中の全繰返し単位の５モル％（モル分率として０．０５）以上有し、それ以外の該化学構造または該化学構造以外の化学構造を繰返し単位として含む共重合体からなる水溶性導電性高分子化合物であっても、前記該化学構造のうち２つ以上を繰返し単位として含み且つ該化学構造以外の繰返し単位を含む共重合体からなる水溶性導電性高分子化合物であってもよい。
前記の水溶性導電性高分子化合物に含まれる一般式（Ｉ）乃至（ＶＩ）で示される化学構造の少なくとも一つからなる繰返し単位の重合体中のモル分率は、０．０５以上であればよいが、０．１０以上であることが望ましく、０．２５以上であることが更に望ましい。かかる導電性高分子化合物の中で、一般式（Ｉ）乃至（ＶＩ）で示される化学構造のいずれか一つのみを含む単独または共重合体中の場合には、その化学構造からなる繰返し単位のモル分率が、０．５０以上、あるいは該化学構造の２つ以上を含む共重合体の場合には、該化学構造からなる２つ以上の繰返し単位のモル分率の合計が０．５０以上であるものが特に望ましい。
【００１４】
一般式（Ｉ）乃至（ＶＩ）の、Ｒ₁ 、Ｒ₂ 、Ｒ₃ およびＲ₄ はそれぞれ独立にＨ、炭素数１乃至２０の直鎖状もしくは分岐状の飽和もしくは不飽和アルキル、アルコキシまたはアルキルエステル基、ハロゲン、ＳＯ₃ ^-Ｍ（但しＲ₁ またはＲ₂ の場合にはＭはＨ⁺ を表わす。）、ニトロ基、シアノ基、脂肪族あるいは芳香属等の１級、２級または３級アミノ基、クロロメチル等のトリハロメチル基、フェニル基及び置換フェニル基からなる群の一価基から選ばれる。
【００１５】
ここで、Ｒ₁ 、Ｒ₂ 、Ｒ₃ およびＲ₄ として特に有用な例としては、Ｈ（水素）、アルキル基、アルコキシ基、アルキルエステル基、フェニルおよび置換フェニル基、ＳＯ₃ ^-Ｍ（但しＲ₁ またはＲ₂ の場合にはＭはＨ⁺ を表わす。）が挙げられる。これらの置換基を更に詳しく例示すれば、アルキル基としてはメチル、エチル、プロピル、アリル、イソプロピル、ブチル、１−ブテニル、ペンチル、ヘキシル、ヘプチル、オクチル、ノニル、デシル、ウンデシル、ドデシル、テトラデシル、ヘキサデシル、エトキシエチル、メトキシエチル、メトキシエトキシエチル、アセトニル、フェナシル等、アルコキシ基としてはメトキシ、エトキシ、プロポキシ、イソプロポキシ、ブトキシ、ペンチルオキシ、ヘキシルオキシ、オクチルオキシ、ドデシルオキシ、メトキシエトキシ、メトキシエトキシエトキシ等、アルキルエステル基としては、メトキシカルボニル、エトキシカルボニル、ブトキシカルボニル等のアルコキシカルボニル基、アセトキシ、ブチロイルオキシ等のアシルオキシ基、置換フェニル基としてはフルオロフェニル基、クロロフェニル基、ブロモフェニル基、メチルフェニル基、メトキシフェニル基等が挙げられる。上記のＲ₁ 、Ｒ₂ 、Ｒ₃ およびＲ₄ がアルキル基、アルコキシ基またはアルキルエステル基の場合は、その鎖中には、カルボニル、エーテル、エステル、アミド、スルフィド、スルフィニル、スルホニル、イミノ結合を任意に含有してもよい。
【００１６】
一般式（Ｉ）乃至（ＶＩ）の、Ｒ₁ 、Ｒ₂ 、Ｒ₃ およびＲ₄ の前記の置換基の中で、Ｈ、炭素数１乃至２０の直鎖状もしくは分岐状のアルキル基またはアルコキシ基が望ましく、また、Ｈまたは炭素数１乃至２０の直鎖状もしくは分岐状のアルコキシ基が特に望ましい。
【００１７】
Ｒ₁ とＲ₂ 、またはＲ₃ とＲ₄ は互いに任意の位置で結合して、該置換基により置換されている原子を含む飽和または不飽和の、例えば炭化水素の、環状構造または複素環を形成する二価基を形成してもよく、かかる二価基の例としてはブチレン、ペンチレン、ヘキシレン、ブタジエニレン、置換ブタジエニレン、メチレンジオキシなどが挙げられる。
【００１８】
一般式（ＩＩ）、一般式（ＩＶ）および一般式（ＶＩ）において、ＭはＮＲ₅ Ｒ₆ Ｒ₇ Ｒ₈ ⁺で表わされる第４級アンモニウムのカチオン、ＰＲ₅ Ｒ₆ Ｒ₇ Ｒ₈ ⁺ 、ＡｓＲ₅ Ｒ₆ Ｒ₇ Ｒ₈ ⁺で表わされるＶｂ族元素の第４級カチオン、あるいはＮａ⁺ 、Ｌｉ⁺ 、Ｋ⁺ 等のアルカリ金属イオンを表わし、Ｒ₅ 、Ｒ₆ 、Ｒ₇ 、Ｒ₈ はそれぞれ独立にＨ、炭素数１乃至３０の直鎖状もしくは分岐状の置換もしくは非置換アルキル基、または置換もしくは非置換アリール基を表わし、アルコキシ基、ヒドロキシル基、オキシアルキレン基、チオアルキレン基、アゾ基、アゾベンゼン基、ｐ−ジフェニレンオキシ基のごとき炭素、水素以外の元素を含む基を含むアルキルまたはアリール基であってもよい。
【００１９】
かかるＮＲ₅ Ｒ₆ Ｒ₇ Ｒ₈ ⁺で表わされる第４級アンモニウムのカチオンとしては、例えばＮＨ₄ ⁺、ＮＨ（ＣＨ₃ ）₃ ⁺、ＮＨ（Ｃ₆ Ｈ₅ ）₃ ⁺、ＮＨ（ＣＨ₃ ）₂ （ＣＨ₂ ＯＨ）（ＣＨ₂ −Ｚ）⁺ 等の非置換またはアルキル置換もしくはアリール置換型カチオンが用いられる（但し、Ｚは化学式量が６００以下の任意の置換基を表し、例えば、フェノキシ基、ｐ−ジフェニレンオキシ基、ｐ−アルコキシジフェニレンオキシ基、ｐ−アルコキシフェニルアゾフェノキシ基等の置換基である。）。またＰＲ₅ Ｒ₆ Ｒ₇ Ｒ₈ ⁺、ＡｓＲ₅ Ｒ₆ Ｒ₇ Ｒ₈ ⁺で表わされるＶｂ族元素の第４級カチオンとしては例えばＰＨ₄ ⁺、ＰＨ（ＣＨ₃ ）₃ ⁺、ＰＨ（Ｃ₆ Ｈ₅ ）₃ ⁺、ＡｓＨ₄ ⁺、ＡｓＨ（ＣＨ₃ ）₃ ⁺、ＡｓＨ（Ｃ₆ Ｈ₅ ）₃ ⁺等の非置換またはアルキル置換もしくはアリール置換型カチオンが用いられる。特定カチオンに変換するために、通常のイオン交換樹脂を用いてもよい。
【００２０】
また、かかるＲ₅ 、Ｒ₆ 、Ｒ₇ 及びＲ₈ から選ばれる複数の置換基は、互いに任意の位置で結合して、該置換基により置換されている原子を含む飽和または不飽和の複素環を形成する二価基を少なくとも１つ以上形成してもよい。Ｒ₅ 、Ｒ₆ 、Ｒ₇ 、Ｒ₈ がアルキル基の場合は、その鎖中には、カルボニル、エーテル、エステル、アミド、スルフィド、スルフィニル、スルホニル、イミノなどの結合を任意に含んでもよい。前記二価基の例としてはブチレン、ペンチレン、ヘキシレン、ブタジエニレン、置換ブタジエニレン、メチレンジオキシなどが挙げられる。
【００２１】
一般式（ＩＩ）、一般式（ＩＶ）および一般式（ＶＩ）において、望ましいＭの例としては、ＮＲ₅ Ｒ₆ Ｒ₇ Ｒ₈ ⁺で表わされる第４級アンモニウムのカチオン、Ｎａ⁺ 、Ｌｉ⁺ またはＫ⁺ 等のアルカリ金属イオンが挙げられ、、ＮＲ₅ Ｒ₆ Ｒ₇ Ｒ₈ ⁺が特に望ましい。
【００２２】
また一般式（ＩＩ）、一般式（ＩＶ）および一般式（ＶＩ）において、Ｒ₅ 、Ｒ₆ 、Ｒ₇ およびＲ₈ としては、それぞれ独立にＨまたは炭素数１乃至３０の直鎖状もしくは分岐状のアルキル基が望ましい。
【００２３】
本発明において、Ｒ₁ 〜Ｒ₈ 及びＭの記号で表される原子団は互いに完全に独立である。すなわち、異なる一般式における場合は勿論のこと、同一の一般式において重複して用いられている場合も独立である。例えば一般式（Ｉ）の繰り返し単位と一般式（ＩＩＩ）の繰り返し単位を含む共重合体の場合でも、一般式（Ｉ）におけるＲ₁ がＨであっても、一般式（ＩＩＩ）におけるＲ₁ はＨである必要はない。また、例えば化学式（ＶＩ）においてＳＯ₃ ^-ＭのＭがＮＨ₄ ⁺であっても、Ｒ₃ （＝ＳＯ₃ ^-Ｍの場合）のＭがＮＨ₄ ⁺である必要はない。
【００２４】
本発明に用いられる水溶性導電性高分子化合物が共重合体の場合には、一般式（Ｉ）乃至（ＶＩ）で示される化学構造以外の繰返し単位として、ビニレン、チエニレン、ピロリレン、フェニレン、イミノフェニレン、イソチアナフテニレン、フリレン、カルバゾリレンおよびこれらの置換誘導体構造があげられる。
【００２５】
係る共重合体においては、上記一般式（Ｉ）乃至（ＶＩ）で示される化学構造以外の繰返し単位（スルホン酸基を有しない繰り返し単位）は、共重合体組成中のモル分率として０．９５未満、即ち重合体の全繰返し単位の９５モル％未満であればよく、それ以上の場合には重合体の共重合組成にもよるが、多くの場合水溶性を示さなくなるなどの理由から本発明に係る水溶性の導電性化合物として好ましくない。水溶性等の点で、望ましい共重合体はかかるモル分率が０．９０未満のものであり、０．７５未満のものがさらに望ましい。
【００２６】
本発明において、用いられる水溶性導電性高分子化合物の分子量は、特に限定されないが、塗布等の方法で膜を形成する工程を含むような方法で使用される場合には、２０００以上であることが望ましく、また塗布等の方法で膜を形成した後除去する工程を含むような方法で使用される場合には、良好な除去性を有する分子量であればよく、例えば百万程度以下であればよい。分子量が２０００未満の低分子の化合物であっては、塗布等の方法で膜を好適に形成させることができないことがあり、あるいは高分子自体の導電性も小さく好ましくないことがある。また、分子量が百万を越える高分子化合物であっては、その溶解性あるいは除去性の面で問題となることがある。
【００２７】
本発明の水溶性導電性高分子化合物を含む水溶液において、前記水溶性導電性高分子化合物等の固体成分の濃度には特に制限はない。固体成分より水の方が重量比で多い場合としては、本発明の水溶性導電性高分子化合物を含む水溶液を塗布等の方法で膜を形成して使用する場合が挙げられ、その場合、固体成分の濃度は０．００１重量％以上５０重量％未満の範囲が好適であり、望ましくは０．０１〜２０重量％、さらに望ましくは０．１〜５重量％である。５０重量％より濃度が高くなると、均一な溶液が得られないことがある。一方、固体成分より水の方が重量比で少ない場合としては、本発明の水溶性導電性高分子化合物を含む水溶液を、そのまま固体または湿潤状態で製造または使用する場合が挙げられ、その場合、水分の量は重量比で固体成分１００に対して１００以下の範囲が好適であり、望ましくは５０以下、更に望ましくは２５以下である。かかる重量比が１００より大きくなると、固体または湿潤状態としての取り扱い上不都合をきたすことがある。
【００２８】
本発明の水溶性導電性高分子化合物を含む水溶液は、上述の一般式（Ｉ）乃至（ＶＩ）で示される化学構造の少なくとも一つを繰返し単位として含み且つ主鎖がπ共役系二重結合を有する水溶性導電性高分子化合物の他、少なくとも一種の界面活性剤、他の水溶性高分子あるいは他の水溶性化合物を含んでもよい。これらは本発明の水溶性導電性高分子化合物を含む水溶液に制限を与えるものではない。界面活性剤としては、例えば、アニオン界面活性剤、カチオン界面活性剤、非イオン界面活性剤、シリコーン系界面活性剤、フッ素系界面活性剤等が挙げられる。かかる界面活性剤を用いる場合には、該水溶性導電性高分子化合物に対して重量比で０．００１〜９５倍量、望ましくは０．００５〜２０倍量、更に望ましくは０．０１〜５倍量用いる。界面活性剤の量が０．００１倍量未満であると、界面活性剤添加の効果がなくなる場合がある。９５倍量より多いと、良好な電子伝導性が確保できない場合がある。水溶性高分子としては、例えばポリビニルアルコール（ＰＶＡ）、セルロース系の親水性高分子、ポリアクリルアミドあるいはアクリルアミド共重合体、ポリアクリル酸、アクリル酸共重合体、ポリスチレンスルホン酸、あるいはこれらの誘導体等が挙げられる。この場合、該水溶性導電性高分子化合物は良好な導電性の確保のために、他の水溶性高分子に対して５重量％以上、望ましくは１０重量％以上、さらに望ましくは２０重量％以上にする。
【００２９】
本発明の水溶性導電性高分子化合物を含む水溶液は、前記一般式（Ｉ）および一般式（ＩＩ）で示される化学構造の含有比を変化させることにより、酸性〜アルカリ性の間の任意のｐＨの値をとることが可能である。前記一般式（Ｉ）で示される化学構造の含有比が大きくなれば酸性が強くなり、一般式（ＩＩ）で示される化学構造の含有比が大きくなればアルカリ性が強くなる。同様に前記一般式（ＩＩＩ）および一般式（ＩＶ）、または一般式（Ｖ）および一般式（ＶＩ）において同様に化学構造の含有比を変化させて、任意のｐＨの値をとることも可能である。また上記導電性高分子化合物を含む水溶液は、さらに酸やアルカリを添加してｐＨの値を変化させることも可能である。
【００３０】
前述のように前記水溶性導電性高分子化合物を含む水溶液は、常温で長期保存すると、溶液のｐＨが低下し、また溶液で保存した後塗布等の方法で形成した膜の表面抵抗が上昇するという問題があった。本発明者らの鋭意検討の結果、溶液のｐＨの低下は硫酸イオン濃度の増加と対応し、膜の表面抵抗の上昇は、紫外可視近赤外吸収スペクトルの変化と対応していることを発見した（比較例１参照）。硫酸イオンの増加は前記水溶性導電性高分子化合物の脱スルホン反応を示唆し、紫外可視近赤外吸収スペクトルの変化はπ電子共役系の劣化（酸化されすぎによるものと考えられる）を示唆している。通常このような反応をおさえる方法としては冷蔵保存等により保管温度を低下する方法が用いられるが、使用上の大きな制約となり、常温保存が望まれているのは前述の通りである。
【００３１】
本発明者らは鋭意検討の結果、前記水溶性導電性高分子化合物を含み、実質的に酸素を含有しない水溶液を用いることによって、常温でも上記の物性変化を防止できることを発見し、本発明に至った。すなわち本発明によれば、常温で保存した場合にも、塗布等の方法で形成した膜の表面抵抗の上昇を防止できるだけでなく、溶液のｐＨの低下を防止することができる。
【００３２】
前記水溶性導電性高分子化合物を含み、実質的に酸素を含有しない水溶液は、前記水溶性導電性高分子化合物を含む固体を酸素遮断雰囲気中で実質的に酸素を含有しない水等に溶解させても得られるし、また前記水溶性導電性高分子化合物を含み、実質的に酸素を含有する水溶液に脱酸素処理を加えても得られる。
【００３３】
水等を脱酸素する方法としては、酸素遮断雰囲気中（例えば不活性ガス中）で不活性ガスをバブリングさせてもよく、また酸素遮断雰囲気中（例えば不活性ガス中）で水等を撹拌するだけでも容易に脱酸素化できる。その他加熱脱気や真空脱気のような機械式脱気、水素添加、還元剤添加や電気化学的脱気のような溶存酸素除去法、膜式脱気などいかなる方法を用いてもよい（参考文献としては表面実装技術誌、１９９３年８月号、４２頁が挙げられる）。このうちでは、操作性、導電性高分子化合物に影響を与える不純物を含まないこと及びコスト面などから酸素遮断雰囲気中（例えば不活性ガス中）で水等を撹拌する方法および膜式脱気法が望ましい。通常の水は常温、大気下では５〜９ｐｐｍの酸素を含んでいるが、上記脱酸素法により容易に０．０１ｐｐｍ未満に下げることができる。本発明において用いられる実質的に酸素を含有しない水等は、通常溶存酸素濃度が１ｐｐｍ以下が好ましい。より大きな効果を期待する場合には、さらに０．１ｐｐｍ以下がより望ましく、またさらには０．０１ｐｐｍ未満が特に望ましい。実質的に酸素を含有しない水等は、大気中に放置すると容易に酸素が溶解し酸素濃度が上昇するので、酸素遮断雰囲気中（例えば不活性ガス中）で保存する必要がある。
【００３４】
前記水溶性導電性高分子化合物を含み、実質的に酸素を含有する水溶液に脱酸素処理を加える方法としては、酸素遮断雰囲気中（例えば不活性ガス中）で不活性ガスを水溶液中でバブリングさせる方法、酸素遮断雰囲気中（例えば不活性ガス中）で水溶液を撹拌する方法、限外濾過膜などを用いて溶媒の水を上記の方法で得られた脱酸素水と置換する方法などが挙げられる。このうち操作性、純度、コスト等の点から酸素遮断雰囲気中（例えば不活性ガス中）で水溶液を撹拌する方法および限外濾過膜などを用いて溶媒の水を上記の方法で得られた脱酸素水と置換する方法が望ましいが、本発明はこれらの脱酸素方法に制約されるものではない。その他用途に応じて水の場合と同様、加熱脱気や真空脱気のような機械式脱気、水素添加、還元剤添加や電気化学的脱気のような溶存酸素除去法を用いることも可能である。
【００３５】
前記水溶性導電性高分子化合物を含み、実質的に酸素を含有しない水溶液を、酸素遮断状態で保存する方法としては、例えば不活性ガス中のような酸素遮断雰囲気中で保存する方法や、例えば延伸ポリビニルアルコールを含むフィルムやアルミニウム等の金属を蒸着したフィルムなど酸素遮断フィルムでラップする方法が挙げられる。前記水溶性導電性高分子化合物を含み、実質的に酸素を含有しない水溶液も、実質的に酸素を含有しない水等と同様に、大気中に放置すると容易に酸素が溶解し酸素濃度が上昇する。この現象は密栓したポリプロピレンボトル中に保管しておいても観測されるので、上記のような酸素遮断対策が必要である。
【００３６】
前記水溶性導電性高分子化合物を含み、実質的に酸素を含有しない水溶液は、塗布等の方法により膜を形成し導電性被膜として使用することもできる。膜を形成する塗布等の方法とは、具体的には、本発明の水溶性導電性高分子化合物を含み、実質的に酸素を含有しない水溶液を物品に塗布する、あるいはその物品を該水溶液にディッピング（浸漬する）、あるいは物品に吹きつける等、物品や目的に応じて様々な方法が挙げられる。例えば物品上に塗布する際、塗布性等の被膜形成能を改善するために、前記のように少なくとも一種の界面活性剤を含む本発明の水溶液を用いることができる。
【００３７】
【作用】
前記導電性高分子化合物を含み、実質的に酸素を含有しない水溶液は、水溶液状態で常温で放置しても、硫酸イオン濃度の増加がみられず、従って溶液のｐＨが安定である。また同様に前記導電性高分子化合物を含み、実質的に酸素を含有しない水溶液は、水溶液状態で常温で放置しても、紫外可視近赤外吸収スペクトルに変化がみられず、また塗布等の方法で形成した膜の表面抵抗の上昇もなく安定である。さらに前記水溶性導電性高分子化合物を含み、実質的に酸素を含有しない水溶液を、酸素遮断状態で保存する方法により、酸素の侵入を防ぎ水溶液状態での安定保存を可能とした。
【００３８】
【実施例】
以下、本発明を実施例および比較例を用いて詳細に説明するが、以下の実施例は本発明の範囲を制限するものではない。
本実施例および比較例に用いた水溶性導電性高分子化合物を含む水溶液は、具体的には、
▲１▼；以下の式（Ｉａ）
【化１９】

で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が１，３−イソチアナフテニレンである共重合体を含む水溶液、
▲２▼；式（ＩＩａ）
【化２０】

で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が１，３−イソチアナフテニレンである共重合体を含む水溶液、
【００３９】
▲３▼；前記式（Ｉａ）で示される構造単位を繰返し単位とする単独重合体を含む水溶液、
▲４▼；前記式（ＩＩａ）で示される構造単位を繰返し単位とする単独重合体を含む水溶液、
▲５▼；前記式（Ｉａ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が前記式（ＩＩａ）で示される構造単位である共重合体を含む水溶液、
【００４０】
▲６▼；式（ＩＩｂ）
【化２１】

で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が５−デシルオキシ−１，３−イソチアナフテニレンである共重合体を含む水溶液、▲７▼；式（ＩＩＩａ）
【化２２】

で示される重合体を含む水溶液、
および▲８▼；式（ＶＩａ）
【化２３】

で示される重合体を含む水溶液である。但し式中ｎは重合度を表わす整数である。
【００４１】
上記水溶性導電性高分子化合物を含む水溶液の製造方法を以下に示す。
▲１▼；（Ｉａ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が１，３−イソチアナフテニレンである共重合体の水溶性導電性高分子化合物を含む水溶液を製造する方法
特開平6-49183 号公報に開示されている方法を参考に、発煙硫酸（２０％ ＳＯ₃ ）１．５ｇを１０℃に保持し、１，３−ジヒドロイソチアナフテン８２５ｍｇを撹拌しながらゆっくりと加えた。放置して室温まで戻し１時間撹拌を続けたところ、反応液は赤紫色を呈した。その後、７０℃に加熱すると反応液は濃紺色に変化し、３０分後には固化した。反応混合物を１００ｍｌの０．１Ｎ ＮａＯＨ／メタノール中に投入し、沈降した重合物を遠心分離した。重合物を水１００ｍｌに溶解し、透析膜を通して不純物の硫酸ナトリウムを除去した。水溶液から水を留去し、真空乾燥して濃青色共重合体４３０ｍｇを得た。
【００４２】
さらにこの共重合体２００ｍｇを水１００ｍｌに溶解し、酸型のイオン交換樹脂（アンバーライトＩＲ−１２０Ｂ）でイオン交換処理することによって、目的とする共重合体を含む水溶液を得た。中和滴定によってスルホン酸基の定量を行ない、共重合体組成中における（Ｉａ）で示される構造単位からなる繰返し単位のモル分率を求めたところ、０．８４（８４モル％）であった。ＧＰＣにより分子量を測定すると、重量平均分子量は１５０００であった。水を蒸発させ、乾燥して得られた黒色共重合体の電気伝導度を四端子法で測定すると、１Ｓ／ｃｍであった。この黒色共重合体１００ｍｇを水１０ｍｌに溶解して、（Ｉａ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が１，３−イソチアナフテニレンである共重合体の水溶性導電性高分子化合物を含む水溶液（ｐＨ＝１．７）が得られた。
【００４３】
▲２▼；（ＩＩａ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が１，３−イソチアナフテニレンである共重合体の水溶性導電性高分子化合物を含む水溶液を製造する方法
▲１▼で得られた水溶液に、１Ｎ ＮＨ₄ ＯＨ溶液４ｍｌを加えｐＨ＝９．４に調製した。この操作によりスルホン酸基のＨ⁺ イオンはＮＨ₄ ⁺イオンに容易に交換され、（Ｉａ）で示される構造単位は（ＩＩａ）で示される構造単位に変換され、目的物の（ＩＩａ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が１，３−イソチアナフテニレンである共重合体の水溶性導電性高分子化合物を含む水溶液（ｐＨ＝９．４）が得られた。
【００４４】
▲３▼；式（Ｉａ）で示される構造単位を繰返し単位とする単独重合体を含む水溶液を製造する方法
発煙硫酸（２０％ ＳＯ₃ ）４ｍｌを２０℃以下に保持し、１，３−ジヒドロイソチアナフテン１．０ｇを撹拌しながらゆっくりと加えた。放置して室温まで戻し４時間撹拌を続けたところ、反応液は褐色を呈した。反応混合物を氷水１５０ｍｌに溶解し、塩化ナトリウム２０ｇを加え加温して均一に溶かし、ゆっくりと塩析させ、析出物を遠心分離機により分離した。上澄液を除去後、真空乾燥し、精製操作を経て、１，３−ジヒドロ−５−イソチアナフテンスルホン酸ナトリウム（白色粉末）３５０ｍｇを得た。
【００４５】
上記の方法に従い製造した、１，３−ジヒドロ−５−イソチアナフテンスルホン酸ナトリウム２．０ｇを塩化第二鉄１０ｇと混合し、水４ｇを加えて撹拌した。１時間後に得られた黒色の反応混合物を、水２００ｍｌ、およびアセトン２００ｍｌでよく洗い、乾燥して０．９ｇの黒色粉末を得た。この黒色粉末を５０ｍｌの０．１Ｎ ＮａＯＨに良く撹拌しながら溶解し、沈殿物を除去した後、酸型のイオン交換樹脂でイオン交換することによって、目的とする単独重合体を含む水溶液（ｐＨ＝２．０）を得た。前述の方法と同様の方法で測定した、重合体の式（Ｉａ）で示される構造単位からなる繰返し単位のモル分率は１．００（１００モル％）、重量平均分子量は１２０００、電気伝導度は２Ｓ／ｃｍであった。
【００４６】
▲４▼；式（ＩＩａ）で示される構造単位を繰返し単位とする単独重合体を含む水溶液を製造する方法
上記▲３▼の製造で得られた水溶液に１Ｎ ＮＨ₄ ＯＨ水溶液を加え、ｐＨ＝９．０に調製した。この操作によりスルホン酸基のＨ⁺ イオンはＮＨ₄ ⁺イオンに容易に交換され、（Ｉａ）で示される構造単位は（ＩＩａ）で示される構造単位に変換され、目的物の（ＩＩａ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位がイソチアナフテニレンである共重合体の水溶性導電性高分子化合物を含む水溶液（ｐＨ＝９．０）が得られた。
【００４７】
▲５▼；式（Ｉａ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が前記式（ＩＩａ）で示される構造単位である共重合体を含む水溶液を製造する方法
上記▲３▼の製造で得られた水溶液に１Ｎ ＮＨ₄ ＯＨ水溶液を加え、ｐＨを５．０に調製した。この操作によりスルホン酸基のＨ⁺ イオンの一部はＮＨ₄ ⁺イオンに容易に交換される。これにより（Ｉａ）で示される構造単位の一部は（ＩＩａ）で示される構造単位に変換され、目的物の水溶液（ｐＨ＝５．０）が得られた。
【００４８】
▲６▼；（ＩＩｂ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が５−デシルオキシ−１，３−イソチアナフテニレンである共重合体の水溶性導電性高分子化合物を含む水溶液を製造する方法
特開平6-49183 号公報に開示されている方法を参考にポリ（５−デシルオキシ−１，３−ジヒドロイソチアナフテニレン）５００ｍｇを撹拌しながら、発煙硫酸（２０％ ＳＯ₃ ）４ｍｌをゆっくりと加えて８０℃に加熱すると、反応液は濃青色を呈した。反応混合物２００ｍｇを約５００ｍｌの水に溶解し、塩酸でｐＨを１．９に調製し限外瀘過によって精製、濃縮した後、溶媒留去、真空乾燥により黒色共重合体１５０ｍｇを得た。また中和滴定によってスルホン酸基の定量を行ない、共重合体組成中における（ＩＩｂ）の繰返し単位のモル分率を求めたところ５１モル％であった。ＧＰＣにより分子量を測定すると、重量平均分子量は８０００であった。
さらにこの共重合体を含む水溶液をトリメチルアミンで中和しｐＨ＝９．５に調製して目的物の水溶液を得た。
【００４９】
▲７▼；（ＩＩＩａ）で示される水溶性導電性高分子化合物は、特開平6-145386号公報に開示されている方法を用いて製造した。
▲８▼；（ＶＩａ）で示される水溶性導電性高分子化合物は、特開平4-349614号公報に開示されている方法を用いて製造した。
【００５０】
（比較例１）
▲３▼で得られた、（Ｉａ）で示される構造単位を繰返し単位とする単独重合体を含む水溶液（ｐＨ＝２．０）、
▲４▼で得られた、（ＩＩａ）で示される構造単位を繰返し単位とする単独重合体を含む水溶液（ｐＨ＝９．０）、
及び▲５▼で得られた、（Ｉａ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が前記式（ＩＩａ）で示される構造単位である共重合体を含む水溶液（ｐＨ＝５．０）
を用いて、水溶液状態のまま常温で放置しながら、重合体を含む水溶液の経時変化をそのｐＨ（図１）、その塗布膜の表面抵抗（図２）、及びその水溶液の硫酸イオン濃度（図３）を測定することにより調べ、さらに製造直後及び３ヶ月後の水溶液の紫外可視近赤外吸収スペクトル（図４）を調べた。
【００５１】
水溶液のｐＨは、ガラス電極式水素イオン濃度計ｐＨ ＭＥＴＥＲ Ｆ−１３（（株）堀場製作所製）にて測定した。水溶液の硫酸イオン濃度は、イオンクロマトグラフィー ＤＩＯＮＥＸ ＱＩＣ（分離カラムＡＳ−４Ａ）（ＤＩＯＮＥＸ Ｃｏｒｐｏｒａｔｉｏｎ製）にて測定した。水溶液の紫外可視近赤外吸収スペクトルは、水溶液０．５ｍｌに対してヒドラジン一水和物１ｍｌを加え、純水で１００ｍｌに希釈して、自記分光光度計Ｕ−３５００型（（株）日立製作所製）にて測定した。
【００５２】
また塗布膜の表面抵抗は、スピンナーＩＨ−ＩＩＩ（協栄セミコンダクター（株）製）を用いて、水溶液をガラス基板に１５００ｒｐｍで回転塗布し、膜厚０．０２μｍの導電性被膜を作製し、この塗布膜の表面抵抗を表面抵抗測定器メガレスタＭＯＤＥＬ ＨＴ−３０１（シシド静電気（株）製）にて測定した値である。
【００５３】
図１、２から明らかなように▲３▼で得られたｐＨ＝２．０の水溶液、▲４▼で得られたｐＨ＝９．０の水溶液及び▲５▼で得られたｐＨ＝５．０の水溶液のいずれもが、常温で水溶液状態で放置すると、ｐＨが低下し、表面抵抗が上昇した。この変化は、例えば特開平4-32848 号公報に記載のように、荷電粒子線を照射する工程において帯電現象を防止する目的で使われる場合には極めて影響が大きい。電子材料１９９０年１２月ｐ．４８−５４によれば、こうした帯電現象を防止するには表面抵抗が５×１０⁷ Ω／□以下であることが求められているので、ｐＨ＝９．０およびｐＨ＝５．０の水溶液は１ヵ月常温放置後にはその効果がなくなることがわかる。ｐＨ＝２．０のものも２カ月常温放置後には、上限に近づいている。また図３および、図４〜６から明らかなように、これらの変化は水溶液の硫酸イオン濃度の上昇や、水溶液の紫外可視近赤外吸収スペクトルの変化に対応していることがわかった。
【００５４】
（実施例１）
比較例１で用いた、
▲３▼で得られた、（Ｉａ）で示される構造単位を繰返し単位とする単独重合体を含む水溶液（ｐＨ＝２．０）、
▲４▼で得られた、（ＩＩａ）で示される構造単位を繰返し単位とする単独重合体を含む水溶液（ｐＨ＝９．０）、
及び▲５▼で得られた、（Ｉａ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が前記式（ＩＩａ）で示される構造単位である共重合体を含む水溶液（ｐＨ＝５．０）
を各々窒素雰囲気に保ったグローブバッグ中に置き、窒素ガスを３０分間各水溶液中に吹込んでバブリングして脱酸素処理を加えた。この操作により水溶液中の酸素濃度は５．１２ｐｐｍから０．０１ｐｐｍ未満に低下した。なお酸素濃度は、パーソナル溶存酸素メータ９０Ｓｅｒｉｅｓ ＴＯＸ−９０ｉ（（株）東興化学研究所製）にて測定した。
【００５５】
これらの実質的に酸素を含有しない水溶液を、窒素雰囲気のままグローブボックス中で（脱酸素状態で）常温で放置し、比較例１と同様に、重合体を含む水溶液の経時変化をそのｐＨ（図１）、その塗布膜の表面抵抗（図２）、及びその水溶液の硫酸イオン濃度（図３）を測定することにより調べ、さらに製造直後及び３ヶ月後の水溶液の紫外可視近赤外吸収スペクトル（図４〜６）を調べた。水溶液中の酸素濃度は測定期間中０．０１ｐｐｍ未満を保っていた。
【００５６】
図１〜６から明らかなように、比較例１で観測された物性の変化は、脱酸素された水溶液では大幅に抑えられていることがわかる。水溶液を脱酸素することによって、塗布膜の表面抵抗及び水溶液の紫外可視近赤外吸収スペクトルの変化の抑制のみならず、水溶液のｐＨ及び硫酸イオン濃度の変化までも抑える効果が観測されたことは特筆に値する。
【００５７】
（実施例２）
▲１▼で得られた、式（Ｉａ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が１，３−イソチアナフテニレンである共重合体を含む水溶液（ｐＨ＝１．７）
及び▲２▼で得られた、式（ＩＩａ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が１，３−イソチアナフテニレンである共重合体を含む水溶液（ｐＨ＝９．４）
を窒素雰囲気に保ったグローブバッグ中に置き、各溶液を撹拌することによって脱酸素処理を加えた。この操作による水溶液中の酸素濃度の変化は図７の通りであり、撹拌３０分後には酸素濃度は０．０１ｐｐｍ未満に低下した。
【００５８】
これらの実質的に酸素を含有しない水溶液を、延伸ポリビニルアルコールを含む酸素遮断フィルム（延伸ポリプロピレン２０μｍ／延伸ポリビニルアルコール（大倉工業製エバールＸＬ）１２μｍ／ポリエチレン７５μｍ）でラップして常温で放置し、実施例１と同様の方法で、水溶液のｐＨ、及び塗布膜の表面抵抗の経時変化を調べた。酸素濃度は３ヵ月後も０．０１ｐｐｍ未満であった。脱酸素処理を加えなかった場合と比較しながら、以下の表にまとめる。
【００５９】

【００６０】
（比較例２）
実施例２と全く同様に、▲１▼及び▲２▼で得られた水溶液に脱酸素処理を加えた。脱酸素された水溶液をポリプロピレン容器に密閉し、大気中で常温で放置した。３ヵ月後には酸素濃度は５．４０ｐｐｍに達していた。また同様に水溶液のｐＨ、及び塗布膜の表面抵抗の経時変化を調べたところ、実施例２の脱酸素なしの場合と同様の結果が得られた。
【００６１】
（実施例３）
▲６▼で得られた、式（ＩＩｂ）で示される構造単位を繰返し単位として含み、該構造単位以外の繰返し単位が５−デシルオキシ−１，３−イソチアナフテニレンである共重合体を含む水溶液、
▲７▼で得られた、式（ＩＩＩａ）で示される重合体を含む水溶液、
および▲８▼で得られた、式（ＶＩａ）で示される重合体を含む水溶液
を各々脱気装置ＤＯＲ、ＬＤＯシステム（三浦工業（株）製）を用いて製造した脱酸素水による希釈、限外濾過膜による濃縮を繰返すことによって、脱酸素水と置換して、脱酸素処理した。酸素濃度は０．０１ｐｐｍ未満であった。
【００６２】
これらの実質的に酸素を含有しない水溶液を、アルミ箔を含む酸素遮断フィルム（ポリエステル１２μｍ／アルミ箔７μｍ／ポリエチレン４０μｍ）でラップして常温で放置し、実施例２と同様の方法で、水溶液のｐＨ、及び塗布膜の表面抵抗の経時変化を調べた。酸素濃度は３ヵ月後も０．０１ｐｐｍ未満であった。実施例２と同様に脱酸素処理を加えなかった場合と比較しながら、以下の表にまとめる。
【００６３】

【００６４】
【発明の効果】
以上説明したごとく、本発明の前記導電性高分子化合物を含み、実質的に酸素を含有しない水溶液は、常温で放置しても、溶液のｐＨ、塗布等の方法で形成した膜の導電性の低下がみられず安定である。さらに前記水溶性導電性高分子化合物を含み、実質的に酸素を含有しない水溶液を、酸素遮断状態で保存する方法により、水溶液状態での冷蔵庫保管は必要としなくなった。この安定な水溶液は、単体あるいは複合体として塗布等の方法で高い導電性ある重合体として加工あるいは薄膜化することができ、そのため精密な加工の要求される電極、センサー、エレクトロニクス表示素子、非線形光学素子、帯電防止剤など各種導電材料あるいは光学材料として有用なものである。
【図面の簡単な説明】
【図１】重合体を含む水溶液のｐＨの経時変化。
【図２】塗布膜の表面抵抗により表された重合体を含む水溶液の経時変化。
【図３】重合体を含む水溶液の硫酸イオン濃度の経時変化。
【図４】▲３▼で得られた水溶液の製造直後及び３ヶ月後の紫外可視近赤外吸収スペクトル。
【図５】▲５▼で得られた水溶液の製造直後及び３ヶ月後の紫外可視近赤外吸収スペクトル。
【図６】▲４▼で得られた水溶液の製造直後及び３ヶ月後の紫外可視近赤外吸収スペクトル。
【図７】脱酸素処理による水溶液中の酸素濃度の変化。[0001]
[Industrial application fields]
The present invention relates to a conductive polymer compound aqueous solution that is extremely stable even after long-term storage at room temperature, a method for producing the same, and a method for storing the same. More specifically, the present invention relates to an electrode, a sensor, an electronic display element, a nonlinear optical element, a photoelectric conversion element, an antistatic agent, and other various conductive materials or optical materials that have high processing requirements in the electric and electronic industries. The present invention relates to a stable aqueous conductive polymer compound solution suitable for use, a production method thereof, and a storage method.
[0002]
[Prior art]
Polymers with developed π-electron conjugated systems have attracted industrial attention and a lot of research because of their unique physical properties such as state change at the metal / semiconductor transition as well as electrical conductivity. In particular, many conductive polymers such as polyacetylene, polythiophene, polypyrrole, and polyparaphenylene are insoluble and infusible due to their rigid main chain skeleton (Skotheim, "Handbook of Conducting Polymers", published by Mercer Dekker, 1986). However, a polymer in which a substituent such as an alkyl group is introduced into the side chain becomes soluble, and has attracted industrial attention due to its easy processability.
[0003]
A specific example is a polymer made by introducing a long-chain alkyl group into the side chain of polythiophene to make it soluble in an organic solvent (K. Jen et al., Journal of Chemical Society, Chemical Communication, 1346, 1986). In addition, a water-soluble polymer in which an alkyl sulfonic acid group is introduced (AOPatil et al., Journal of American Chemical Society, Vol. 109, p. 1858, 1987) is known.
[0004]
The latter example is known as a water-soluble self-doped polymer, generally having a Bronsted acid group covalently bonded directly or indirectly through a spacer to the main chain of the π-electron conjugated polymer, Attention has also been given to the state of conduction without contribution. Other examples of such reports include polythiophene derivatives from EEHavinga et al. (Polymer Bulletin, Vol. 18, 277, 1987), Aldissi polythiophene derivatives and polypyrrole derivatives (US Pat. No. 4,880,508), polyaniline aromatic rings. A polymer having a carboxylic acid group covalently bonded thereto as a substituent (Patent Publication No. 1-500835), a polymer having a propanesulfonic acid group substituted at the N-position of pyrrole (Journal of Chemical Society, Chemical Communication, 621 1987), polyaniline polymer substituted with a propanesulfonic acid group at the N position (Journal of Chemical Society, Chemical Communication, 180, 1990, and Synthetic Metal, 31, 369, 1989), Polyaniline derivatives in which sulfonic acid groups are directly substituted on the aromatic ring (Journal of American Chemical Society, 112, 2800, 1990), isothianaphthe substituted with sulfonic acid groups Like polymer (Japanese Patent Laid-Open No. 6 -49183) discloses the manufacturing process.
[0005]
As described above, a self-doped polymer in which a Bronsted acid group is covalently bonded directly to the main chain of a π-electron conjugated polymer or indirectly through a spacer is water-soluble and can conduct electricity without contribution of foreign dopants. Researches aiming at many industrial applications have been made because it shows the state and can easily be thinned and its conductivity is stable over a long period of time. (Application examples of self-doping polymers include JP-A-4-32848 and JP-A-4-349614 for preventing charging in the process of irradiating a charged particle beam, and JP-A-4-304914 on conductive composite materials. (There are many such as 328181 and JP-A-6-145386)
[0006]
[Problems to be solved by the invention]
However, among the above self-doped polymers, polymers having an isothianaphthene skeleton, pyrrole skeleton or aniline skeleton in the π-electron conjugated polymer main chain have a relatively low oxidation potential and are easily p-type doped (oxidized). Therefore, although the conductive state is stable in a solid state (for example, a film state), there is a problem that physical properties change when left in an aqueous solution at room temperature (see Comparative Example 1). When left in an aqueous solution at room temperature, an increase in the surface resistance (decrease in conductivity) of the film formed by a change in the pH of the solution or a method of application becomes a problem as a physical property. For this reason, storage in an aqueous solution has limitations such as storage temperature.
[0007]
In order to solve the above problems and eliminate the limitation of the storage method, an aqueous solution of a self-doped polymer having an isothianaphthene skeleton, pyrrole skeleton, or aniline skeleton, which is stable even when left at room temperature, and a method for producing the same Was desired. Furthermore, there has been a demand for a storage method for keeping the physical properties stable even at room temperature without storing the aqueous solution in a refrigerator.
[0008]
OBJECT OF THE INVENTION
The first object of the present invention is to provide an aqueous solution of a self-doped polymer having an isothianaphthene skeleton, pyrrole skeleton or aniline skeleton, which is stable even when left at room temperature.
The second object of the present invention is to provide a method for producing a self-doped polymer aqueous solution having an isothianaphthene skeleton, pyrrole skeleton or aniline skeleton, which is stable even when left at room temperature.
The third object of the present invention is to provide a method for storing a self-doped polymer aqueous solution having an isothianaphthene skeleton, pyrrole skeleton or aniline skeleton, which is stable even when left at room temperature.
[0009]
[Means for Solving the Problems]
The above object is achieved by the general formula
Embedded image

Formula (II)
Embedded image

Formula (III)
Embedded image

Formula (IV)
Embedded image

General formula (V)
Embedded image

And general formula (VI)
Embedded image

(Wherein R₁ , R₂ , R_Three And R_Four Are each independently H, straight-chain or branched saturated or unsaturated alkyl, alkoxy or alkyl ester group having 1 to 20 carbon atoms, halogen, SO_Three ^-M (however, R₁ Or R₂ In the case of M is H⁺ Represents. ), Nitro group, cyano group, primary, secondary or tertiary amino group, trihalomethyl group, phenyl group and substituted phenyl group. M is NR_Five R₆ R₇ R₈ ⁺A quaternary ammonium cation represented by PR_Five R₆ R₇ R₈ ⁺, AsR_Five R₆ R₇ R₈ ⁺A quaternary cation of the group Vb element represented by⁺ , Li⁺ , K⁺ Represents an alkali metal ion such as R_Five , R₆ , R₇ , R₈ Each independently represents H, a linear or branched substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted aryl group, an alkoxy group, a hydroxyl group, an oxyalkylene group, a thioalkylene group , An azo group, an azobenzene group, a p-diphenyleneoxy group, or an alkyl or aryl group containing a group containing an element other than carbon or hydrogen. R₁ And R₂ Or R_Three And R_Four Or R_Five , R₆ , R₇ And R₈ A plurality of substituents selected from are bonded to each other at an arbitrary position to form at least one divalent group that forms a saturated or unsaturated cyclic structure containing an atom substituted by the substituent. Also good. R₁ , R₂ , R_Three , R_Four , R_Five , R₆ , R₇ , R₈ Is an alkyl group, or R₁ , R₂ , R_Three , R_Four When is an alkoxy group or an alkyl ester group, the chain may optionally contain a bond such as carbonyl, ether, ester, amide, sulfide, sulfinyl, sulfonyl, imino and the like. This is achieved by an aqueous solution containing a water-soluble conductive polymer compound containing at least one of the chemical structures represented by (II) as a repeating unit and having a π-conjugated double bond in the main chain and substantially not containing oxygen.
[0010]
Furthermore, the second object is that the above general formulas (I) to (VI) (wherein R₁ , R₂ , R_Three , R_Four And M are the same as above. )
An aqueous solution containing a water-soluble conductive polymer compound containing at least one of the chemical structures represented by formula (1) as a repeating unit and having a π-conjugated double bond in the main chain is deoxygenated. This is achieved by a method for producing an aqueous molecular compound solution.
[0011]
The third object is to use the general formulas (I) to (VI) (wherein R₁ , R₂ , R_Three , R_Four And M are the same as above. An aqueous solution containing a water-soluble conductive polymer compound containing at least one of the chemical structures represented by) as a repeating unit and having a main chain having a π-conjugated double bond, and containing substantially no oxygen, It is achieved by a method for storing a conductive polymer compound aqueous solution characterized in that it is stored at
[0012]
In the present invention, including as a repeating unit does not necessarily include the unit continuously, and includes cases where the unit is included irregularly or discontinuously like a random copolymer or a block copolymer.
The present invention will be described in detail below.
[0013]
The water-soluble conductive polymer compound in which the main chain used in the present invention has a π-conjugated double bond includes at least one of the chemical structures represented by the general formulas (I) to (VI) as a repeating unit. It is a water-soluble conductive polymer compound. The water-soluble conductive polymer compound is a water-soluble conductive polymer comprising a homopolymer having any one of the chemical structures represented by the general formulas (I) to (VI) as a repeating unit. Or, having at least one of the chemical structures as a repeating unit, 5 mol% or more (0.05 as a mole fraction) of all repeating units in the polymer, other than this chemical structure or other than this chemical structure Even a water-soluble conductive polymer compound comprising a copolymer containing the chemical structure as a repeating unit includes a copolymer containing two or more of the chemical structures as a repeating unit and a repeating unit other than the chemical structure. It may be a water-soluble conductive polymer compound made of a polymer.
The molar fraction in the polymer of the repeating unit comprising at least one of the chemical structures represented by the general formulas (I) to (VI) contained in the water-soluble conductive polymer compound may be 0.05 or more. However, it is preferably 0.10 or more, and more preferably 0.25 or more. Among such conductive polymer compounds, in the case of a homopolymer or copolymer containing only one of the chemical structures represented by the general formulas (I) to (VI), a repeating unit comprising the chemical structure In the case of a copolymer containing two or more of the chemical structures, the sum of the molar fractions of two or more repeating units comprising the chemical structures is 0.50. The above is particularly desirable.
[0014]
R in the general formulas (I) to (VI)₁ , R₂ , R_Three And R_Four Are each independently H, straight-chain or branched saturated or unsaturated alkyl, alkoxy or alkyl ester group having 1 to 20 carbon atoms, halogen, SO_Three ^-M (however, R₁ Or R₂ In the case of M is H⁺ Represents. ), Nitro, cyano, aliphatic or aromatic primary, secondary or tertiary amino groups, trihalomethyl groups such as chloromethyl, phenyl groups and substituted phenyl groups. .
[0015]
Where R₁ , R₂ , R_Three And R_Four Particularly useful examples of such as H (hydrogen), alkyl groups, alkoxy groups, alkyl ester groups, phenyl and substituted phenyl groups, SO_Three ^-M (however, R₁ Or R₂ In the case of M is H⁺ Represents. ). More specific examples of these substituents include methyl, ethyl, propyl, allyl, isopropyl, butyl, 1-butenyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tetradecyl, hexadecyl. , Ethoxyethyl, methoxyethyl, methoxyethoxyethyl, acetonyl, phenacyl, etc., alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, octyloxy, dodecyloxy, methoxyethoxy, methoxyethoxyethoxy, etc. Alkyl ester groups include alkoxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl and butoxycarbonyl, acyloxy groups such as acetoxy and butyroyloxy, Fluorophenyl group as a phenyl group, chlorophenyl group, bromophenyl group, methylphenyl group, methoxyphenyl group and the like. R above₁ , R₂ , R_Three And R_Four When is an alkyl group, an alkoxy group or an alkyl ester group, the chain may optionally contain a carbonyl, ether, ester, amide, sulfide, sulfinyl, sulfonyl or imino bond.
[0016]
R in the general formulas (I) to (VI)₁ , R₂ , R_Three And R_Four Of these substituents, H is preferably a linear or branched alkyl group or alkoxy group having 1 to 20 carbon atoms, and H or a linear or branched alkoxy group having 1 to 20 carbon atoms. Groups are particularly desirable.
[0017]
R₁ And R₂ Or R_Three And R_Four May be bonded to each other at any position to form a divalent group that forms a saturated or unsaturated, for example, hydrocarbon, cyclic structure or heterocycle containing an atom substituted by the substituent, Examples of such divalent groups include butylene, pentylene, hexylene, butadienylene, substituted butadienylene, methylenedioxy and the like.
[0018]
In general formula (II), general formula (IV), and general formula (VI), M is NR._Five R₆ R₇ R₈ ⁺A quaternary ammonium cation represented by PR_Five R₆ R₇ R₈ ⁺ , AsR_Five R₆ R₇ R₈ ⁺A quaternary cation of the group Vb element represented by⁺ , Li⁺ , K⁺ Represents an alkali metal ion such as R_Five , R₆ , R₇ , R₈ Each independently represents H, a linear or branched substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted aryl group, an alkoxy group, a hydroxyl group, an oxyalkylene group, a thioalkylene group, It may be an alkyl or aryl group containing a group containing an element other than carbon and hydrogen, such as an azo group, an azobenzene group, and a p-diphenyleneoxy group.
[0019]
Such NR_Five R₆ R₇ R₈ ⁺As the quaternary ammonium cation represented by the formula, for example, NH_Four ⁺, NH (CH_Three )_Three ⁺, NH (C₆ H_Five )_Three ⁺, NH (CH_Three )₂ (CH₂ OH) (CH₂ -Z)⁺ Or an alkyl-substituted or aryl-substituted cation such as Z is an arbitrary substituent having a chemical formula weight of 600 or less. For example, phenoxy group, p-diphenyleneoxy group, p-alkoxydiphenylene And a substituent such as an oxy group and a p-alkoxyphenylazophenoxy group). Also PR_Five R₆ R₇ R₈ ⁺, AsR_Five R₆ R₇ R₈ ⁺Examples of the quaternary cation of the group Vb element represented by_Four ⁺, PH (CH_Three )_Three ⁺, PH (C₆ H_Five )_Three ⁺, AsH_Four ⁺, AsH (CH_Three )_Three ⁺, AsH (C₆ H_Five )_Three ⁺Unsubstituted or alkyl-substituted or aryl-substituted cations such as are used. In order to convert to a specific cation, a normal ion exchange resin may be used.
[0020]
Also, such R_Five , R₆ , R₇ And R₈ A plurality of substituents selected from are bonded to each other at any position to form at least one divalent group that forms a saturated or unsaturated heterocyclic ring containing an atom substituted by the substituent. Also good. R_Five , R₆ , R₇ , R₈ In the case where is an alkyl group, the chain may optionally contain a bond such as carbonyl, ether, ester, amide, sulfide, sulfinyl, sulfonyl, imino and the like. Examples of the divalent group include butylene, pentylene, hexylene, butadienylene, substituted butadienylene and methylenedioxy.
[0021]
Examples of desirable M in the general formula (II), the general formula (IV), and the general formula (VI) include NR_Five R₆ R₇ R₈ ⁺A quaternary ammonium cation represented by Na⁺ , Li⁺ Or K⁺ And alkali metal ions such as NR_Five R₆ R₇ R₈ ⁺Is particularly desirable.
[0022]
In general formula (II), general formula (IV) and general formula (VI), R_Five , R₆ , R₇ And R₈ Are preferably independently H or a linear or branched alkyl group having 1 to 30 carbon atoms.
[0023]
In the present invention, R₁ ~ R₈ And the atomic groups represented by the symbols M are completely independent of each other. That is, not only in the case of different general formulas, but also in the case of being used repeatedly in the same general formula. For example, even in the case of a copolymer containing a repeating unit of the general formula (I) and a repeating unit of the general formula (III), R in the general formula (I)₁ Is R in the general formula (III)₁ Need not be H. Further, for example, in the chemical formula (VI), SO_Three ^-M of M is NH_Four ⁺Even R_Three (= SO_Three ^-M is NH)_Four ⁺Need not be.
[0024]
When the water-soluble conductive polymer compound used in the present invention is a copolymer, as a repeating unit other than the chemical structure represented by the general formulas (I) to (VI), vinylene, thienylene, pyrrolylene, phenylene, imino Examples include phenylene, isothianaphthenylene, furylene, carbazolylene, and substituted derivative structures thereof.
[0025]
In such a copolymer, repeating units other than the chemical structures represented by the above general formulas (I) to (VI) (repeating units having no sulfonic acid group) have a molar fraction of 0. 0 in the copolymer composition. This may be less than 95, that is, less than 95 mol% of the total repeating unit of the polymer. In the case of more than that, it depends on the copolymer composition of the polymer, but in many cases it is not water-soluble. It is not preferable as a water-soluble conductive compound according to the invention. In terms of water solubility and the like, a desirable copolymer has a mole fraction of less than 0.90, and more preferably less than 0.75.
[0026]
In the present invention, the molecular weight of the water-soluble conductive polymer compound to be used is not particularly limited, but when used in a method including a step of forming a film by a method such as coating, it is 2000 or more. In addition, when used in a method including a step of removing after forming a film by a method such as coating, the molecular weight may have a good removability, for example, about 1 million or less Good. In the case of a low molecular weight compound having a molecular weight of less than 2000, a film may not be suitably formed by a method such as coating, or the conductivity of the polymer itself may be small and unfavorable. Moreover, in the case of a polymer compound having a molecular weight exceeding 1 million, there may be a problem in terms of solubility or removability.
[0027]
In the aqueous solution containing the water-soluble conductive polymer compound of the present invention, the concentration of the solid component such as the water-soluble conductive polymer compound is not particularly limited. Examples of the case where water is larger in weight ratio than the solid component include a case where an aqueous solution containing the water-soluble conductive polymer compound of the present invention is used by forming a film by a method such as coating. The concentration of the component is preferably in the range of 0.001% by weight or more and less than 50% by weight, preferably 0.01 to 20% by weight, more preferably 0.1 to 5% by weight. If the concentration is higher than 50% by weight, a uniform solution may not be obtained. On the other hand, as a case where water is less in weight ratio than the solid component, an aqueous solution containing the water-soluble conductive polymer compound of the present invention may be produced or used as it is in a solid or wet state. The amount of water is preferably in the range of 100 or less, preferably 50 or less, and more preferably 25 or less in terms of weight ratio with respect to the solid component 100. When the weight ratio is larger than 100, it may be inconvenient in handling as a solid or wet state.
[0028]
The aqueous solution containing the water-soluble conductive polymer compound of the present invention contains at least one of the chemical structures represented by the above general formulas (I) to (VI) as a repeating unit and the main chain is a π-conjugated double bond In addition to the water-soluble conductive polymer compound having at least one, it may contain at least one surfactant, other water-soluble polymer, or other water-soluble compound. These do not limit the aqueous solution containing the water-soluble conductive polymer compound of the present invention. Examples of the surfactant include an anionic surfactant, a cationic surfactant, a nonionic surfactant, a silicone-based surfactant, and a fluorine-based surfactant. When such a surfactant is used, it is 0.001 to 95 times, preferably 0.005 to 20 times, more preferably 0.01 to 5 times by weight with respect to the water-soluble conductive polymer compound. Use double amount. If the amount of the surfactant is less than 0.001 times, the effect of adding the surfactant may be lost. If the amount is more than 95 times, good electron conductivity may not be ensured. Examples of the water-soluble polymer include polyvinyl alcohol (PVA), cellulose-based hydrophilic polymer, polyacrylamide or acrylamide copolymer, polyacrylic acid, acrylic acid copolymer, polystyrene sulfonic acid, or derivatives thereof. Can be mentioned. In this case, the water-soluble conductive polymer compound is 5% by weight or more, preferably 10% by weight or more, more preferably 20% by weight or more with respect to another water-soluble polymer in order to ensure good conductivity. To.
[0029]
The aqueous solution containing the water-soluble conductive polymer compound of the present invention has an arbitrary pH between acidic and alkaline by changing the content ratio of the chemical structures represented by the general formula (I) and the general formula (II). It is possible to take the value of When the content ratio of the chemical structure represented by the general formula (I) is increased, the acidity is increased. When the content ratio of the chemical structure represented by the general formula (II) is increased, the alkalinity is increased. Similarly, in the general formula (III) and the general formula (IV), or in the general formula (V) and the general formula (VI), the content ratio of the chemical structure can be similarly changed to take any pH value. It is. Further, the aqueous solution containing the conductive polymer compound can be further changed in pH value by adding an acid or an alkali.
[0030]
As described above, when the aqueous solution containing the water-soluble conductive polymer compound is stored at room temperature for a long time, the pH of the solution decreases, and the surface resistance of the film formed by a method such as coating after storage in the solution increases. There was a problem. As a result of intensive studies by the present inventors, it was discovered that a decrease in the pH of the solution corresponds to an increase in the sulfate ion concentration, and an increase in the surface resistance of the film corresponds to a change in the ultraviolet-visible near-infrared absorption spectrum. (See Comparative Example 1). An increase in sulfate ion suggests a desulfonation reaction of the water-soluble conductive polymer compound, and a change in the UV-Vis near-infrared absorption spectrum suggests deterioration of the π-electron conjugated system (which is thought to be due to over-oxidation) ing. Usually, as a method of suppressing such a reaction, a method of lowering the storage temperature by refrigerated storage or the like is used. However, as described above, the storage at normal temperature is desired because of a significant limitation in use.
[0031]
As a result of intensive studies, the present inventors have found that the above physical property change can be prevented even at room temperature by using an aqueous solution containing the water-soluble conductive polymer compound and containing substantially no oxygen. It came. That is, according to the present invention, not only can the surface resistance of the film formed by a method such as coating be prevented even when stored at room temperature, but also the pH of the solution can be prevented from decreasing.
[0032]
The aqueous solution containing the water-soluble conductive polymer compound and substantially free of oxygen is obtained by dissolving a solid containing the water-soluble conductive polymer compound in water substantially free of oxygen in an oxygen-blocking atmosphere. It can also be obtained by adding a deoxygenation treatment to an aqueous solution containing the water-soluble conductive polymer compound and substantially containing oxygen.
[0033]
As a method for deoxygenating water or the like, an inert gas may be bubbled in an oxygen-blocking atmosphere (for example, in an inert gas), or water or the like is stirred in an oxygen-blocking atmosphere (for example, in an inert gas). Can be easily deoxygenated. Other methods such as mechanical deaeration such as heat deaeration and vacuum deaeration, hydrogenation, dissolved oxygen removal method such as addition of a reducing agent and electrochemical deaeration, and membrane deaeration may be used. The literature includes Surface Mount Technology Journal, August 1993, page 42). Among them, a method of stirring water and the like in a oxygen-blocking atmosphere (for example, in an inert gas) and a membrane-type deaeration method from the viewpoint of operability, no inclusion of impurities affecting the conductive polymer compound, and cost Is desirable. Ordinary water contains 5 to 9 ppm of oxygen at room temperature and in the atmosphere, but can be easily reduced to less than 0.01 ppm by the above deoxygenation method. The water or the like containing substantially no oxygen used in the present invention preferably has a dissolved oxygen concentration of usually 1 ppm or less. In the case of expecting a greater effect, the content is further desirably 0.1 ppm or less, and further desirably less than 0.01 ppm. Water or the like that does not substantially contain oxygen needs to be stored in an oxygen-blocking atmosphere (for example, in an inert gas) because oxygen easily dissolves and the oxygen concentration increases when left in the air.
[0034]
As a method of adding a deoxygenation treatment to an aqueous solution containing the water-soluble conductive polymer compound and substantially containing oxygen, an inert gas is bubbled in the aqueous solution in an oxygen-blocking atmosphere (for example, in an inert gas). Methods, a method of stirring an aqueous solution in an oxygen-blocking atmosphere (for example, in an inert gas), a method of substituting water of a solvent with deoxygenated water obtained by the above method using an ultrafiltration membrane or the like. . Among these, from the viewpoints of operability, purity, cost, etc., the water of the solvent was removed by the above method using a method of stirring an aqueous solution in an oxygen-blocking atmosphere (for example, in an inert gas) and an ultrafiltration membrane. Although a method of replacing oxygen water is desirable, the present invention is not limited to these deoxygenation methods. As with water, it is possible to use dissolved oxygen removal methods such as mechanical deaeration such as heat deaeration and vacuum deaeration, hydrogenation, reducing agent addition, and electrochemical deaeration as in the case of water. It is.
[0035]
Examples of a method for storing an aqueous solution containing the water-soluble conductive polymer compound and containing substantially no oxygen in an oxygen-blocked state include a method of storing in an oxygen-blocked atmosphere such as in an inert gas, for example, Examples thereof include a method of wrapping with an oxygen barrier film such as a film containing stretched polyvinyl alcohol or a film on which a metal such as aluminum is deposited. An aqueous solution containing the water-soluble conductive polymer compound and containing substantially no oxygen, like water or the like containing substantially no oxygen, easily dissolves oxygen and raises the oxygen concentration when left in the atmosphere. . Since this phenomenon is observed even when stored in a tightly sealed polypropylene bottle, it is necessary to take measures against oxygen blocking as described above.
[0036]
An aqueous solution containing the water-soluble conductive polymer compound and containing substantially no oxygen can also be used as a conductive film by forming a film by a method such as coating. Specifically, the coating method or the like for forming a film is a method of applying an aqueous solution containing the water-soluble conductive polymer compound of the present invention and containing substantially no oxygen to an article, or applying the article to the aqueous solution. There are various methods depending on the article and purpose, such as dipping (soaking) or spraying on the article. For example, when coating on an article, the aqueous solution of the present invention containing at least one surfactant as described above can be used in order to improve the film forming ability such as coatability.
[0037]
[Action]
An aqueous solution containing the conductive polymer compound and containing substantially no oxygen does not show an increase in sulfate ion concentration even when left at room temperature in an aqueous solution state, and therefore the pH of the solution is stable. Similarly, an aqueous solution containing the conductive polymer compound and containing substantially no oxygen does not show a change in the ultraviolet-visible near-infrared absorption spectrum even when it is left at room temperature in the aqueous solution state. The film formed by the method is stable without increasing the surface resistance. Further, an aqueous solution containing the water-soluble conductive polymer compound and containing substantially no oxygen is stored in an oxygen-blocked state to prevent entry of oxygen and enable stable storage in an aqueous solution state.
[0038]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example and a comparative example, the following Examples do not restrict | limit the scope of the present invention.
Specifically, the aqueous solution containing the water-soluble conductive polymer compound used in the examples and comparative examples is:
(1): The following formula (Ia)
Embedded image

An aqueous solution containing a copolymer in which a repeating unit other than the structural unit is 1,3-isothianaphthenylene,
(2); Formula (IIa)
Embedded image

An aqueous solution containing a copolymer in which a repeating unit other than the structural unit is 1,3-isothianaphthenylene,
[0039]
(3) An aqueous solution containing a homopolymer having the structural unit represented by the formula (Ia) as a repeating unit,
(4) An aqueous solution containing a homopolymer having the structural unit represented by the formula (IIa) as a repeating unit,
(5) An aqueous solution containing a copolymer containing the structural unit represented by the formula (Ia) as a repeating unit and a repeating unit other than the structural unit being the structural unit represented by the formula (IIa),
[0040]
(6); Formula (IIb)
Embedded image

An aqueous solution containing a copolymer containing a structural unit represented by formula (II) as a repeating unit, and a repeating unit other than the structural unit being 5-decyloxy-1,3-isothianaphthenylene, (7); formula (IIIa)
Embedded image

An aqueous solution containing a polymer represented by
And (8); Formula (VIa)
Embedded image

It is the aqueous solution containing the polymer shown by these. In the formula, n is an integer representing the degree of polymerization.
[0041]
The manufacturing method of the aqueous solution containing the said water-soluble conductive polymer compound is shown below.
(1): An aqueous solution containing a water-soluble conductive polymer compound of a copolymer containing the structural unit represented by (Ia) as a repeating unit and the repeating unit other than the structural unit being 1,3-isothianaphthenylene How to manufacture
Referring to the method disclosed in JP-A-6-49183, fuming sulfuric acid (20% SO_Three ) 1.5 g was held at 10 ° C. and 825 mg of 1,3-dihydroisothianaphthene was added slowly with stirring. When the mixture was allowed to stand and returned to room temperature and stirring was continued for 1 hour, the reaction solution showed a reddish purple color. Thereafter, when heated to 70 ° C., the reaction liquid turned dark blue and solidified after 30 minutes. The reaction mixture was put into 100 ml of 0.1N NaOH / methanol, and the precipitated polymer was centrifuged. The polymer was dissolved in 100 ml of water, and impurities sodium sulfate was removed through a dialysis membrane. Water was distilled off from the aqueous solution, followed by vacuum drying to obtain 430 mg of a dark blue copolymer.
[0042]
Furthermore, 200 mg of this copolymer was dissolved in 100 ml of water and subjected to ion exchange treatment with an acid type ion exchange resin (Amberlite IR-120B) to obtain an aqueous solution containing the target copolymer. The sulfonic acid group was quantified by neutralization titration, and the molar fraction of the repeating unit consisting of the structural unit represented by (Ia) in the copolymer composition was found to be 0.84 (84 mol%). . When the molecular weight was measured by GPC, the weight average molecular weight was 15000. When the electric conductivity of the black copolymer obtained by evaporating water and drying was measured by the four-terminal method, it was 1 S / cm. 100 mg of this black copolymer is dissolved in 10 ml of water, the structural unit represented by (Ia) is contained as a repeating unit, and the repeating unit other than the structural unit is 1,3-isothianaphthenylene. An aqueous solution (pH = 1.7) containing a water-soluble conductive polymer compound was obtained.
[0043]
(2); an aqueous solution containing a water-soluble conductive polymer compound of a copolymer containing the structural unit represented by (IIa) as a repeating unit and the repeating unit other than the structural unit being 1,3-isothianaphthenylene How to manufacture
1N NH is added to the aqueous solution obtained in (1)._Four The pH was adjusted to 9.4 by adding 4 ml of OH solution. By this operation, H of the sulfonic acid group⁺ Ion is NH_Four ⁺The structural unit represented by (Ia) is easily converted into an ion and converted to the structural unit represented by (IIa), and contains the structural unit represented by (IIa) of the target product as a repeating unit. An aqueous solution (pH = 9.4) containing a water-soluble conductive polymer compound of a copolymer having a repeating unit of 1,3-isothianaphthenylene was obtained.
[0044]
(3) Method for producing an aqueous solution containing a homopolymer having the structural unit represented by formula (Ia) as a repeating unit
Fuming sulfuric acid (20% SO_Three ) 4 ml was kept below 20 ° C. and 1.0 g of 1,3-dihydroisothianaphthene was slowly added with stirring. The mixture was allowed to return to room temperature and stirred for 4 hours. As a result, the reaction solution became brown. The reaction mixture was dissolved in 150 ml of ice water, 20 g of sodium chloride was added and heated to dissolve uniformly, and salted out slowly, and the precipitate was separated by a centrifuge. After removing the supernatant, it was vacuum-dried and subjected to purification operation to obtain 350 mg of sodium 1,3-dihydro-5-isothianaphthenesulfonate (white powder).
[0045]
2.0 g of sodium 1,3-dihydro-5-isothianaphthenesulfonate prepared according to the above method was mixed with 10 g of ferric chloride, and 4 g of water was added and stirred. The black reaction mixture obtained after 1 hour was thoroughly washed with 200 ml of water and 200 ml of acetone and dried to obtain 0.9 g of a black powder. This black powder was dissolved in 50 ml of 0.1N NaOH with good stirring, the precipitate was removed, and then ion exchange was performed with an acid ion exchange resin, whereby an aqueous solution containing the desired homopolymer (pH = 2.0). The molar fraction of the repeating unit consisting of the structural unit represented by the formula (Ia) of the polymer measured by the same method as described above was 1.00 (100 mol%), the weight average molecular weight was 12000, and the electrical conductivity. Was 2 S / cm.
[0046]
(4) Method for producing an aqueous solution containing a homopolymer having the structural unit represented by formula (IIa) as a repeating unit
1N NH was added to the aqueous solution obtained in the production of (3) above._Four An aqueous OH solution was added to adjust the pH to 9.0. By this operation, H of the sulfonic acid group⁺ Ion is NH_Four ⁺The structural unit represented by (Ia) is easily converted into an ion and converted to the structural unit represented by (IIa), and contains the structural unit represented by (IIa) of the target product as a repeating unit. An aqueous solution (pH = 9.0) containing a water-soluble conductive polymer compound of a copolymer whose repeating unit is isothianaphthenylene was obtained.
[0047]
(5) Method for producing an aqueous solution containing a copolymer containing a structural unit represented by the formula (Ia) as a repeating unit, and a repeating unit other than the structural unit being the structural unit represented by the formula (IIa)
1N NH was added to the aqueous solution obtained in the production of (3) above._Four An aqueous OH solution was added to adjust the pH to 5.0. By this operation, H of the sulfonic acid group⁺ Some of the ions are NH_Four ⁺Easily exchanged for ions. Thereby, a part of the structural unit represented by (Ia) was converted to the structural unit represented by (IIa), and an aqueous solution (pH = 5.0) of the target product was obtained.
[0048]
{Circle around (6)} A water-soluble conductive polymer of a copolymer comprising the structural unit represented by (IIb) as a repeating unit, wherein the repeating unit other than the structural unit is 5-decyloxy-1,3-isothianaphthenylene Method for producing an aqueous solution containing a compound
While referring to 500 mg of poly (5-decyloxy-1,3-dihydroisothianaphthenylene) with reference to the method disclosed in JP-A-6-49183, fuming sulfuric acid (20% SO_Three ) When 4 ml was slowly added and heated to 80 ° C., the reaction solution became dark blue. 200 mg of the reaction mixture was dissolved in about 500 ml of water, the pH was adjusted to 1.9 with hydrochloric acid, purified and concentrated by ultrafiltration, the solvent was distilled off, and vacuum drying was performed to obtain 150 mg of a black copolymer. The sulfonic acid group was quantified by neutralization titration, and the molar fraction of the repeating unit (IIb) in the copolymer composition was determined to be 51 mol%. When the molecular weight was measured by GPC, the weight average molecular weight was 8,000.
Further, the aqueous solution containing the copolymer was neutralized with trimethylamine and adjusted to pH = 9.5 to obtain the target aqueous solution.
[0049]
{Circle around (7)} The water-soluble conductive polymer compound represented by (IIIa) was produced using the method disclosed in JP-A-6-145386.
{Circle around (8)} The water-soluble conductive polymer compound represented by (VIa) was produced using the method disclosed in JP-A-4-349614.
[0050]
(Comparative Example 1)
An aqueous solution (pH = 2.0) containing a homopolymer obtained by (3) and having the structural unit represented by (Ia) as a repeating unit;
An aqueous solution (pH = 9.0) containing a homopolymer obtained in (4) and having the structural unit represented by (IIa) as a repeating unit;
And (5), an aqueous solution containing a copolymer containing the structural unit represented by (Ia) as a repeating unit, and a repeating unit other than the structural unit being the structural unit represented by the formula (IIa) ( pH = 5.0)
The time-dependent change of the aqueous solution containing the polymer is measured with respect to its pH (FIG. 1), the surface resistance of the coating film (FIG. 2), and the sulfate ion concentration of the aqueous solution (FIG. 3) was measured, and the ultraviolet-visible near-infrared absorption spectrum (FIG. 4) of the aqueous solution immediately after production and after 3 months was examined.
[0051]
The pH of the aqueous solution was measured with a glass electrode type hydrogen ion concentration meter pH METER F-13 (manufactured by Horiba, Ltd.). The sulfuric acid ion concentration of the aqueous solution was measured by ion chromatography DIONEX QIC (separation column AS-4A) (manufactured by DIONEX Corporation). The UV-Vis near-infrared absorption spectrum of the aqueous solution was obtained by adding 1 ml of hydrazine monohydrate to 0.5 ml of the aqueous solution and diluting to 100 ml with pure water. A self-recording spectrophotometer U-3500 type (Hitachi, Ltd.) Manufactured).
[0052]
Further, the surface resistance of the coating film was spin-coated with a spinner IH-III (manufactured by Kyoei Semiconductor Co., Ltd.), and the aqueous solution was spin-coated on a glass substrate at 1500 rpm to produce a conductive film having a thickness of 0.02 μm. It is the value which measured the surface resistance of the coating film with the surface resistance measuring device MEGARESTA MODEL HT-301 (made by Shishido electrostatic Co., Ltd.).
[0053]
As apparent from FIGS. 1 and 2, the aqueous solution having pH = 2.0 obtained in (3), the aqueous solution having pH = 9.0 obtained in (4), and the pH = 5 obtained in (5). When any of the 0 aqueous solutions was allowed to stand in an aqueous solution state at room temperature, the pH decreased and the surface resistance increased. This change has a great influence when used for the purpose of preventing a charging phenomenon in a process of irradiating a charged particle beam, for example, as described in JP-A-4-32848. Electronic Materials December 1990 p. According to 48-54, in order to prevent such a charging phenomenon, the surface resistance is 5 × 10 5.⁷ Since it is required to be Ω / □ or less, it can be understood that the aqueous solution having pH = 9.0 and pH = 5.0 loses its effect after being left at room temperature for one month. The one with pH = 2.0 is approaching the upper limit after being left at room temperature for 2 months. Further, as is clear from FIG. 3 and FIGS. 4 to 6, it was found that these changes correspond to an increase in the sulfate ion concentration of the aqueous solution and a change in the ultraviolet-visible near-infrared absorption spectrum of the aqueous solution.
[0054]
Example 1
Used in Comparative Example 1,
An aqueous solution (pH = 2.0) containing a homopolymer obtained by (3) and having the structural unit represented by (Ia) as a repeating unit;
An aqueous solution (pH = 9.0) containing a homopolymer obtained in (4) and having the structural unit represented by (IIa) as a repeating unit;
And (5), an aqueous solution containing a copolymer containing the structural unit represented by (Ia) as a repeating unit, and a repeating unit other than the structural unit being the structural unit represented by the formula (IIa) ( pH = 5.0)
Were placed in a glove bag maintained in a nitrogen atmosphere, and nitrogen gas was blown into each aqueous solution for 30 minutes to bubbling for deoxygenation treatment. By this operation, the oxygen concentration in the aqueous solution decreased from 5.12 ppm to less than 0.01 ppm. The oxygen concentration was measured with a personal dissolved oxygen meter 90 Series TOX-90i (manufactured by Toko Chemical Laboratory Co., Ltd.).
[0055]
These substantially oxygen-free aqueous solutions were allowed to stand at room temperature in a glove box (in a deoxygenated state) in a nitrogen atmosphere, and in the same manner as in Comparative Example 1, the change over time of the aqueous solution containing the polymer was changed to its pH ( Fig. 1), the surface resistance of the coating film (Fig. 2), and the sulfate ion concentration of the aqueous solution (Fig. 3) were investigated, and the UV-Vis near-infrared absorption spectrum of the aqueous solution immediately after production and after 3 months. (FIGS. 4-6) were examined. The oxygen concentration in the aqueous solution was kept below 0.01 ppm during the measurement period.
[0056]
As is apparent from FIGS. 1 to 6, it can be seen that the change in physical properties observed in Comparative Example 1 is greatly suppressed in the deoxygenated aqueous solution. By deoxygenating the aqueous solution, the effect of suppressing not only the surface resistance of the coating film and the change in the UV-visible near-infrared absorption spectrum of the aqueous solution but also the change in the pH and sulfate ion concentration of the aqueous solution was observed. Deserves special mention.
[0057]
(Example 2)
An aqueous solution (pH = containing a copolymer obtained by (1) containing the structural unit represented by the formula (Ia) as a repeating unit and a repeating unit other than the structural unit being 1,3-isothianaphthenylene. 1.7)
And (2) an aqueous solution (pH) containing a copolymer represented by the formula (IIa) as a repeating unit, wherein the repeating unit other than the structural unit is 1,3-isothianaphthenylene. = 9.4)
Was placed in a glove bag kept in a nitrogen atmosphere, and each solution was stirred to add deoxidation treatment. The change in the oxygen concentration in the aqueous solution by this operation is as shown in FIG. 7, and after 30 minutes of stirring, the oxygen concentration decreased to less than 0.01 ppm.
[0058]
These oxygen-free aqueous solutions are wrapped with an oxygen-blocking film containing stretched polyvinyl alcohol (stretched polypropylene 20 μm / stretched polyvinyl alcohol (Ekura XL manufactured by Okura Kogyo Co., Ltd.) 12 μm / polyethylene 75 μm) and allowed to stand at room temperature. In the same manner as in Example 1, changes in the pH of the aqueous solution and the surface resistance of the coating film over time were examined. The oxygen concentration was still less than 0.01 ppm after 3 months. The table below summarizes the results when compared with the case where no deoxygenation treatment was added.
[0059]

[0060]
(Comparative Example 2)
In exactly the same manner as in Example 2, deoxidation treatment was applied to the aqueous solutions obtained in (1) and (2). The deoxygenated aqueous solution was sealed in a polypropylene container and left at room temperature in the atmosphere. Three months later, the oxygen concentration reached 5.40 ppm. Similarly, when the change in pH of the aqueous solution and the surface resistance of the coating film over time were examined, the same results as in Example 2 without deoxygenation were obtained.
[0061]
(Example 3)
Including the copolymer obtained by (6) containing the structural unit represented by the formula (IIb) as a repeating unit and the repeating unit other than the structural unit being 5-decyloxy-1,3-isothianaphthenylene Aqueous solution,
An aqueous solution containing the polymer represented by formula (IIIa) obtained in (7),
And an aqueous solution containing the polymer represented by formula (VIa) obtained in (8)
Is replaced with deoxygenated water by repeatedly diluting with deoxygenated water manufactured using deaerator DOR and LDO system (manufactured by Miura Kogyo Co., Ltd.) and concentrating with ultrafiltration membrane, and deoxygenated. did. The oxygen concentration was less than 0.01 ppm.
[0062]
These substantially oxygen-free aqueous solutions are wrapped with an oxygen barrier film containing aluminum foil (polyester 12 μm / aluminum foil 7 μm / polyethylene 40 μm) and allowed to stand at room temperature. Changes with time in pH and surface resistance of the coating film were examined. The oxygen concentration was still less than 0.01 ppm after 3 months. The results are summarized in the following table, as compared with the case where the deoxygenation treatment was not added as in Example 2.
[0063]

[0064]
【The invention's effect】
As described above, the aqueous solution containing the conductive polymer compound of the present invention and containing substantially no oxygen has a conductivity of a film formed by a method such as solution pH, coating, etc. even when left at room temperature. Stable without any decrease. Furthermore, the method of storing an aqueous solution containing the water-soluble conductive polymer compound and containing substantially no oxygen in an oxygen-blocked state eliminates the need for refrigerator storage in the aqueous solution state. This stable aqueous solution can be processed or thinned as a highly conductive polymer by a method such as coating as a single body or a composite, and therefore electrodes, sensors, electronic display elements, nonlinear optics that require precise processing. It is useful as various conductive materials such as elements and antistatic agents or optical materials.
[Brief description of the drawings]
FIG. 1 shows changes in pH of an aqueous solution containing a polymer over time.
FIG. 2 shows the change over time of an aqueous solution containing a polymer represented by the surface resistance of a coating film.
FIG. 3 shows the change over time of the sulfate ion concentration of an aqueous solution containing a polymer.
FIG. 4 is an ultraviolet-visible near-infrared absorption spectrum immediately after production of the aqueous solution obtained in (3) and after 3 months.
FIG. 5 is an ultraviolet-visible near-infrared absorption spectrum immediately after the production of the aqueous solution obtained in (5) and after 3 months.
6 is an ultraviolet-visible near-infrared absorption spectrum immediately after the production of the aqueous solution obtained in (4) and after 3 months. FIG.
FIG. 7 shows changes in oxygen concentration in an aqueous solution due to deoxygenation treatment.

Claims (4)

Formula (I)

Formula (II)

Formula (III)

Formula (IV)

General formula (V)

And general formula (VI)

Wherein R ₁ , R ₂ , R ₃ and R ₄
Each independently H, of 1 to 20 carbon atoms linear or branched, saturated or unsaturated alkyl, alkoxy or alkyl ester group, a halogen, SO ₃ is ^- M (where R ₁
Or, in the case of R ₂ , M represents H ⁺ . ), Nitro group, cyano group, primary, secondary or tertiary amino group, trihalomethyl group, phenyl group and substituted phenyl group. M is a quaternary ammonium cation represented by NR ₅ R ₆ R ₇ R ₈ ⁺ , a quaternary group Vb element represented by PR ₅ R ₆ R ₇ R ₈ ⁺ , AsR ₅ R ₆ R ₇ R ₈ ⁺ Cation or Na ⁺ , Li ⁺
, An alkali metal ion K ^+, _{etc., R 5, R 6, R} 7, R 8 are each independently H or a linear or branched, substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, or, An alkyl group containing a group containing an element other than carbon or hydrogen, such as an alkoxy group, a hydroxyl group, an oxyalkylene group, a thioalkylene group, an azo group, an azobenzene group, a p-diphenyleneoxy group, or a substituted or unsubstituted aryl group; It may be an aryl group. R ₁ and R ₂ or R ₃
And R ₄ , or a plurality of substituents selected from R ₅ , R ₆ , R ₇ and R ₈ are bonded to each other at an arbitrary position, and are saturated or unsaturated containing atoms substituted by the substituents At least one divalent group forming a cyclic structure may be formed. R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ are alkyl groups, or R ₁
, R ₂ , R ₃ , R ₄ are alkoxy groups or alkyl ester groups, the chain may optionally contain bonds such as carbonyl, ether, ester, amide, sulfide, sulfinyl, sulfonyl, imino, etc. . ) And a water-soluble conductive polymer compound having a π-conjugated double bond as a repeating unit and having a dissolved oxygen concentration of 1 ppm or less and substantially oxygen. An aqueous solution containing no. Formula (I)

Formula (II)

Formula (III)

Formula (IV)

General formula (V)

And general formula (VI)

(Wherein R ₁ , R ₂ , R ₃ , R ₄ and M are the same as those in claim 1), which contains at least one of the chemical structures shown as a repeating unit and the main chain is a π-conjugated double A method for producing an aqueous solution of a conductive polymer compound containing substantially no oxygen, wherein a deoxygenation treatment is added to an aqueous solution containing a water-soluble conductive polymer compound having a bond.   A method for preserving an aqueous solution of a conductive polymer compound, comprising storing the aqueous solution according to claim 1 in an oxygen-blocked state.   A method for preventing charging by using the aqueous solution according to claim 1 in a step of irradiating a charged particle beam.

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