JP4118060B2 - Photocatalytic film - Google Patents

Description

（式中、Ｒ³は水素原子またはメチル基、Ａはアルキレン基、好ましくは炭素数１〜４のアルキレン基、Ｒ⁴は加水分解性基または非加水分解性基であるが、その中の少なくとも１つは加水分解により、（Ｂ）成分と化学結合しうる加水分解性基であることが必要であり、また、Ｒ⁴が複数の場合には、各Ｒ⁴はたがいに同一であってもよいし、異なっていてもよく、Ｍ²はケイ素、チタン、ジルコニウム、インジウム、スズ、アルミニウムなどの金属原子、ｋは金属原子Ｍ²の価数である。）
で表される基を挙げることができる。
【００３２】
上記一般式（ＩＩ）において、Ｒ⁴のうちの加水分解により（Ｂ）成分と化学結合しうる加水分解性基としては、例えばアルコキシル基、イソシアネート基、塩素原子などのハロゲン原子、オキシハロゲン基、アセチルアセトネート基、水酸基などが挙げられ、一方、（Ｂ）成分と化学結合しない非加水分解性基としては、例えば低級アルキル基などが好ましく挙げられる。
【００３３】
一般式（ＩＩ）における−Ｍ²Ｒ⁴ _k-1で表される金属含有基としては、例えば、トリメトキシシリル基、トリエトキシシリル基、トリ−ｎ−プロポキシシリル基、トリイソプロポキシシリル基、トリ−ｎ−ブトキシシリル基、トリイソブトキシシリル基、トリ−ｓｅｃ−ブトキシシリル基、トリ−ｔｅｒｔ−ブトキシシリル基、トリクロロシリル基、ジメチルメトキシシリル基、メチルジメトキシシリル基、ジメチルクロロシリル基、メチルジクロロシリル基、トリイソシアナトシリル基、メチルジイソシアナトシリル基など、トリメトキシチタニウム基、トリエトキシチタニウム基、トリ−ｎ−プロポキシチタニウム基、トリイソプロポキシチタニウム基、トリ−ｎ−ブトキシチタニウム基、トリイソブトキシチタニウム基、トリ−ｓｅｃ−ブトキシチタニウム基、トリ−ｔｅｒｔ−ブトキシチタニウム基、トリクロロチタニウム基、さらには、トリメトキシジルコニウム基、トリエトキシジルコニウム基、トリ−ｎ−プロポキシジルコニウム基、トリイソプロポキシジルコニウム基、トリ−ｎ−ブトキシジルコニウム基、トリイソブトキシジルコニウム基、トリ−ｓｅｃ−ブトキシジルコニウム基、トリ−ｔｅｒｔ−ブトキシジルコニウム基、トリクロロジルコニウム基、またさらには、ジメトキシアルミニウム基、ジエトキシアルミニウム基、ジ−ｎ−プロポキシアルミニウム基、ジイソプロポキシアルミニウム基、ジ−ｎ−ブトキシアルミニウム基、ジイソブトキシアルミニウム基、ジ−ｓｅｃ−ブトキシアルミニウム基、ジ−ｔｅｒｔ−ブトキシアルミニウム基、トリクロロアルミニウム基などが挙げられる。
この（ａ）成分のエチレン性不飽和単量体は１種用いてもよいし、２種以上を組み合わせて用いてもよい。
【００３４】
一方、上記（ｂ）成分である金属を含まないエチレン性不飽和単量体としては、例えば一般式（ＩＩＩ）
【００３５】
【化３】

（式中、Ｒ⁵は水素原子またはメチル基、Ｘは一価の有機基である。）
で表されるエチレン性不飽和単量体、好ましくは一般式（ＩＩＩ−ａ）
【００３６】
【化４】

（式中、Ｒ⁵は前記と同じであり、Ｒ⁶は炭化水素基を示す。）
で表されるエチレン性不飽和単量体、あるいは上記一般式（ＩＩＩ−ａ）で表されるエチレン性不飽和単量体と、必要に応じて添加される密着性向上剤としての一般式（ＩＩＩ−ｂ）
【００３７】
【化５】

（式中、Ｒ⁷は水素原子またはメチル基、Ｒ⁸はエポキシ基、ハロゲン原子若しくはエーテル結合を有する炭化水素基を示す。）
で表されるエチレン性不飽和単量体との混合物を挙げることができる。
【００３８】
上記一般式（ＩＩＩ−ａ）で表されるエチレン性不飽和単量体において、Ｒ⁶で示される炭化水素基としては、炭素数１〜１０の直鎖状若しくは分岐状のアルキル基、炭素数３〜１０のシクロアルキル基、炭素数６〜１０のアリール基、炭素数７〜１０のアラルキル基を好ましく挙げることができる。炭素数１〜１０のアルキル基の例としては、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、および各種のブチル基、ペンチル基、ヘキシル基、オクチル基、デシル基などが挙げられる。炭素数３〜１０のシクロアルキル基の例としては、シクロペンチル基、シクロヘキシル基、メチルシクロヘキシル基、シクロオクチル基などが、炭素数６〜１０のアリール基の例としては、フェニル基、トリル基、キシリル基、ナフチル基、メチルナフチル基などが、炭素数７〜１０のアラルキル基の例としては、ベンジル基、メチルベンジル基、フェネチチル基、ナフチルメチル基などが挙げられる。
【００３９】
この一般式（ＩＩＩ−ａ）で表されるエチレン性不飽和単量体の例としては、メチル（メタ）アクリレート、エチル（メタ）アクリレート、プロピル（メタ）アクリレート、ブチル（メタ）アクリレート、ヘキシル（メタ）アクリレート、２−エチルヘキシル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、フェニル（メタ）アクリレート、ベンジル（メタ）アクリレートなどが挙げられる。これらは単独で用いてもよいし、２種以上を組み合わせて用いてもよい。
【００４０】
前記一般式（ＩＩＩ−ｂ）で表されるエチレン性不飽和単量体において、Ｒ⁸で示されるエポキシ基、ハロゲン原子若しくはエーテル結合を有する炭化水素基としては、炭素数１〜１０の直鎖状若しくは分岐状のアルキル基、炭素数３〜１０のシクロアルキル基、炭素数６〜１０のアリール基、炭素数７〜１０のアラルキル基を好ましく挙げることができる。上記置換基のハロゲン原子としては、塩素原子および臭素原子がよい。上記炭化水素基の具体例としては、前述の一般式（ＩＩＩ−ａ）におけるＲ⁶の説明において例示した基と同じものを挙げることができる。
【００４１】
前記一般式（ＩＩＩ−ｂ）で表されるエチレン性不飽和単量体の例としては、グリシジル（メタ）アクリレート、３−グリシドキシプロピル（メタ）アクリレート、２−（３，４−エポキシシクロヘキシル）エチル（メタ）アクリレート、２−クロロエチル（メタ）アクリレート、２−ブロモエチル（メタ）アクリレートなどを好ましく挙げることができる。
【００４２】
また、前記一般式（ＩＩＩ）で表されるエチレン性不飽和単量体としては、これら以外にもスチレン、α−メチルスチレン、α−アセトキシスチレン、ｍ−、ｏ−またはｐ−ブロモスチレン、ｍ−、ｏ−またはｐ−クロロスチレン、ｍ−、ｏ−またはｐ−ビニルフェノール、１−または２−ビニルナフタレンなど、さらにはエチレン性不飽和基を有する重合性高分子用安定剤、例えばエチレン性不飽和基を有する、酸化防止剤、紫外線吸収剤および光安定剤なども用いることができる。これらは単独で用いてもよいし、２種以上を組み合わせて用いてもよい。また、一般式（ＩＩＩ−ａ）で表されるエチレン性不飽和単量体と一般式（ＩＩＩ−ｂ）で表されるエチレン性不飽和単量体とを併用する場合は、前者のエチレン性不飽和単量体に対し、後者のエチレン性不飽和単量体を１〜１００モル％の割合で用いるのが好ましい。
前記（ａ）成分の加水分解性金属含有基を有するエチレン性不飽和単量体と（ｂ）成分の金属を含まないエチレン性不飽和単量体とを、ラジカル重合開始剤の存在下、ラジカル共重合させることにより、（Ａ）成分である加水分解性金属含有基を有する有機高分子化合物が得られる。
【００４３】
一方、（Ｂ）成分の加水分解により金属酸化物を形成し得る金属含有化合物（加水分解性金属含有化合物）としては、一般式（Ｉ）
【００４４】
【化６】

（式中のＲ¹は非加水分解性基、Ｒ²は加水分解性基、Ｍ¹は金属原子を示し、ｍは金属原子Ｍ¹の価数であり、ｎは０＜ｎ≦ｍの関係を満たす整数である。）
で表される化合物又はその縮合オリゴマーが用いられる。
【００４５】
上記一般式（Ｉ）において、Ｒ¹が複数ある場合は、複数のＲ¹は同一であっても異なっていてもよく、Ｒ²が複数ある場合、複数のＲ²は同一であっても異なっていてもよい。Ｒ¹で示される非加水分解性基としては、例えばアルキル基、アリール基、アルケニル基などが好ましく挙げられ、Ｒ²で示される加水分解性基としては、例えば水酸基、アルコキシル基、イソシアネート基、塩素原子などのハロゲン原子、オキシハロゲン基、アセチルアセトネート基などが挙げられる。また、Ｍ¹で示される金属原子としては、例えばケイ素、チタン、ジルコニウム、インジウム、スズ、アルミニウムなどが挙げられる。
【００４６】
この一般式（Ｉ）で表される化合物又はその縮合オリゴマーとしては、例えばテトラメトキシシラン、テトラエトキシシラン、テトラ−ｎ−プロポキシシラン、テトライソプロポキシシラン、テトラ−ｎ−ブトキシシラン、テトライソブトキシシラン、テトラ−ｓｅｃ−ブトキシシラン、テトラ−ｔｅｒｔ−ブトキシシランなど、並びにこれらに対応するテトラアルコキシチタンおよびテトラアルコキシジルコニウム、さらにはトリメトキシアルミニウム、トリエトキシアルミニウム、トリ−ｎ−プロポキシアルミニウム、トリイソプロポキシアルミニウム、トリ−ｎ−ブトキシアルミニウム、トリイソブトキシアルミニウム、トリ−ｓｅｃ−ブトキシアルミニウム、トリ−ｔｅｒｔ−ブトキシアルミニウムなどの金属アルコキシド、あるいは金属アルコキシドオリゴマー、例えば市販品のアルコキシシランオリゴマーである「メチルシリケート５１」、「エチルシリケート４０」（いずれもコルコート社製商品名）、「ＭＳ−５１」、「ＭＳ−５６」（いずれも三菱化学社製商品名）など、さらにはテトライソシアナトシラン、メチルトリイソシアナトシラン、テトラクロロシラン、メチルトリクロロシランなどが挙げられるが、この（Ｂ）成分としては、金属のアルコキシドが好適である。
本発明においては、この加水分解性金属含有化合物は、１種を単独で用いてもよく、２種以上を混合して用いてもよい。
【００４７】
本発明においては、アルコール、ケトン、エーテルなどの適当な極性溶剤中において、前記（Ａ）成分の有機高分子化合物および（Ｂ）成分である少なくとも１種の加水分解性金属含有化合物からなる混合物を塩酸、硫酸、硝酸などの酸、あるいは固体酸としてのカチオン交換樹脂を用い、通常０〜１００℃、好ましくは２０〜６０℃の温度にて加水分解処理し、固体酸を用いた場合には、それを除去したのち、さらに、所望により溶剤を留去または添加し、塗布するのに適した粘度に調節して塗工液からなるコーティング剤を調製する。温度が低すぎる場合は加水分解が進まず、高すぎる場合は逆に加水分解・重合反応が速く進みすぎ、制御が困難となり、その結果得られる傾斜塗膜の傾斜性が低下するおそれがある。
【００４８】
無機成分は、その種類によっては塗工液調製後も、加水分解、重縮合が徐々に進行して塗布条件が変動する場合があるので、塗工液に不溶の固体の脱水剤、例えば無水硫酸マグネシウムなどを添加することにより、ポットライフの低下を防止することができる。この場合、塗工液は、該脱水剤を除去してから、塗布に用いる。
【００４９】
次に、このようにして得られた塗工液からなるコーティング剤を、プラスチックフィルム表面に直接に、または基材フィルム表面に設けられた紫外線遮蔽層上に、乾燥後の平均厚みが４０〜１００ｎｍの範囲になるように、ディップコート法、スピンコート法、スプレーコート法、バーコート法、ナイフコート法、ロールコート法、ブレードコート法、ダイコート法、グラビアコート法などの公知の手段により塗膜を形成し、公知の乾燥処理、例えば４０〜１５０℃程度の温度で加熱乾燥処理することにより、所望の有機−無機複合傾斜膜が形成される。
この複合傾斜膜の平均厚みが４０ｎｍ未満では中間膜としての機能が充分に発揮されず、耐久性の光触媒フィルムが得られにくいし、１００ｎｍを超えるとフィルムのたわみや屈曲によってクラックなどが発生するおそれがある。
【００５０】
本発明においては、この有機−無機複合傾斜膜は、径２ｍｍのステンレス鋼製ロッドに、傾斜膜付きフィルムを該傾斜膜を外側にして３６０°巻き付る２Ｒ曲げでの屈曲試験において、実質上クラックの発生が認められないものであることが必要である。
このような厚みと性状を有する有機−無機複合傾斜膜は、例えば前記コーティング剤を、（Ａ）成分換算量で０．５〜３．０ｇ／１００ｍ２によるように塗布することにより、形成させることができる。
【００５１】
このようにして形成された有機−無機複合傾斜膜においては、表面層は、複合膜中の金属成分の含有率はほぼ１００％であって、基材方向に逐次減少していき、基材近傍ではほぼ０％となる。すなわち、該有機−無機複合傾斜膜は、実質上、プラスチックフィルムに当接している面が有機高分子化合物成分のみからなり、もう一方の開放系面が金属酸化物系化合物成分のみからなっている。
このような傾斜構造の確認は、例えば傾斜膜表面にスパッタリングを施して膜を削っていき、経時的に膜表面の炭素原子と金属原子の含有率を、Ｘ線光電子分光法などにより測定することによって、行うことができる。
【００５２】
この複合傾斜膜における金属成分の含有量としては特に制限はないが、金属酸化物換算で、通常５〜９８重量％、好ましくは２０〜９８重量％、特に好ましくは５０〜９０重量％の範囲である。有機高分子化合物の重合度や分子量としては、製膜化しうるものであればよく特に制限されず、高分子化合物の種類や所望の傾斜膜物性などに応じて適宜選定すればよい。
【００５３】
本発明の光触媒フィルムにおいては、このようにして形成された有機−無機複合傾斜膜上に光触媒活性材料層が設けられる。この光触媒活性材料層に用いられる光触媒活性材料としては特に制限はなく、従来公知のもの、例えば二酸化チタン、チタン酸ストロンチウム（ＳｒＴｉＯ₃）、チタン酸バリウム（ＢａＴｉ₄Ｏ₉）、チタン酸ナトリウム（Ｎａ₂Ｔｉ₆Ｏ₁₃）、二酸化ジルコニウム、α−Ｆｅ₂Ｏ₃、酸化タングステン、Ｋ₄Ｎｂ₆Ｏ₁₇、Ｒｂ₄Ｎｂ₆Ｏ₁₇、Ｋ₂Ｒｂ₂Ｎｂ₆Ｏ₁₇、硫化カドミウム、硫化亜鉛などを挙げることができる。これらは１種を単独で用いてもよいし、２種以上を組み合わせて用いてもよいが、これらの中で、二酸化チタン、特にアナターゼ型二酸化チタンは実用的な光触媒活性材料として有用である。この二酸化チタンは、太陽光などの日常光に含まれる紫外線領域の特定波長の光を吸収することによって優れた光触媒活性を示す。
【００５４】
本発明における光触媒活性材料層には、光触媒活性を促進させる目的で、上記光触媒活性材料と共に、所望により従来公知の光触媒促進剤を含有させることができる。この光触媒促進剤としては、例えば白金、パラジウム、ロジウム、ルテニウムなどの白金族金属が好ましく挙げられる。これらは単独で用いてもよいし、２種以上を組み合わせて用いてもよい。この光触媒促進剤の添加量は、光触媒活性の点から、通常、光触媒活性材料と光触媒促進剤との合計重量に基づき、１〜２０重量％の範囲で選ばれる。
【００５５】
有機−無機複合傾斜膜上に光触媒活性材料層を形成させる方法としては特に制限はなく、様々な方法を用いることができるが、例えば真空蒸着法、スパッタリング法などのＰＶＤ法（物理気相蒸着法）や金属溶射法などの乾式法、塗工液を用いる湿式法などを好ましく挙げることができる。
【００５６】
乾式法としては、装置や操作が簡単である点から、特に金属溶射法が好適である。この金属溶射法は、光触媒活性材料をガス燃焼炎を使用して溶融し、微粒子状にして複合傾斜膜上に吹き付け、光触媒活性材料層を形成させる方法である。この方法においては、光触媒活性材料と共に、光触媒促進剤を用いる場合には、光触媒活性材料と光触媒促進剤との混合物を溶融して、複合傾斜膜上に吹き付けてもよいし、あるいはまず光触媒活性材料の溶融物を複合傾斜膜上に吹き付け、さらにその上に光触媒促進剤の溶融物を吹き付けてもよい。
【００５７】
一方、塗工液を用いる方法においては、適当な溶媒中に、光触媒活性材料および必要に応じて用いられる光触媒促進剤や無機系バインダーなどの微粒子を含む分散液からなる塗工液を調製し、この塗工液を複合傾斜膜上に、公知の方法、例えばディップコート法、スピンコート法、スプレーコート法、バーコート法、ナイフコート法、ロールコート法、ブレードコート法、ダイコート法、グラビアコート法などにより塗布し、自然乾燥または加熱乾燥することにより、光触媒活性材料層を形成させる方法などを用いることができる。また、光触媒促進剤を用いる場合、例えば光触媒活性材料および所望により用いられる無機系バインダーなどの微粒子を含む塗工液を複合傾斜膜上に塗布し、光触媒活性材料の塗膜を形成させたのち、溶存酸素が除去された光触媒促進剤の金属イオンを含む水溶液に、前記の複合傾斜膜上に光触媒活性材料の塗膜が形成されたプラスチックフィルムを浸漬し、光を照射して、該金属イオンを塗膜面に沈積させる光デポジション法により、光触媒活性材料の塗膜上に光触媒促進剤層を設けることによって、光触媒活性材料層を形成させることもできる。
【００５８】
前記塗工液の調製において必要により用いられる無機系バインダーとしては、バインダーとしての機能を発揮し得るものであればよく、特に制限されず、従来公知のもの、例えばケイ素、アルミニウム、チタニウム、ジルコニウム、マグネシウム、ニオビウム、タングステン、スズ、タンタルなどの金属の酸化物や水酸化物、あるいは上記金属の中から選ばれた２種以上の金属の複合酸化物や複合水酸化物などを挙げることができる。この無機系バインダーは１種用いてもよいし、２種以上を組み合わせて用いてもよい。また、該塗工液には、光触媒活性材料層形成用の塗工液に使用される従来公知の他の添加成分、例えばシリコーン樹脂や変性シリコーン樹脂、シランカップリング剤などを含有させることができる。
【００５９】
本発明の光触媒フィルムにおいては、光触媒活性材料層の厚みは、通常１０ｎｍ〜５μｍの範囲で選定される。この厚みが１０ｎｍ未満では光触媒機能が十分に発揮されないし、５μｍを超えると厚みの割には光触媒機能の向上効果が認められず、むしろクラックが生じたり、屈曲性が低下する原因となる。好ましい厚みは３０ｎｍ〜３μｍであり、特に４０ｎｍ〜１μｍの範囲が好ましい。
【００６０】
本発明の光触媒フィルムは、プラスチックフィルム上に有機−無機複合傾斜膜を介して光触媒活性材料層が設けられており、そして、該複合傾斜膜が、実質上、光触媒活性材料層との界面では金属酸化物系化合物成分のみからなり、かつプラスチックフィルムに当接している面では有機高分子化合物成分のみからなるため、基材と複合傾斜膜との密着性および光触媒活性材料層と複合傾斜膜との密着性が極めて良好である。また、光触媒活性材料層との界面において、複合傾斜膜が実質上金属酸化物系化合物成分のみであるため、光触媒活性材料層の光触媒機能による複合傾斜膜の劣化が抑制される。
【００６１】
さらに、本発明の光触媒フィルムは、基材として、プラスチックフィルムを用いているため、光触媒活性材料層の励起に用いられる紫外線などの活性エネルギー線に対し、優れた耐性を有し、耐久性に優れている。また、従来の光触媒フィルムの中間膜の厚みは、数μｍ程度と厚いのに対し、本発明の光触媒フィルムは、中間膜である複合傾斜膜の厚みが４０〜１００ｎｍと薄いために、屈曲性が良好で、フレキシビリティにも富んでいる。
したがって、本発明の光触媒フィルムは、カーボンアーク式サンシャインウェザーメータによる９００時間の促進耐候試験において、全光線透過率およびヘイズ値の低下が、それぞれ５％以下であり、かつ干渉の発生が目視により認められない。
【００６２】
本発明の光触媒フィルムにおいては、プラスチックフィルムの光触媒活性材料層とは反対側の面に、必要により粘着剤層を設けることができる。これにより、本発明の光触媒フィルムを、被着体に容易に貼付することが可能となる。
上記粘着剤層を構成する粘着剤としては特に制限はなく、従来公知の様々な粘着剤の中から、状況に応じて適宜選択して用いることができるが、耐候性などの点から、特にアクリル系、ウレタン系及びシリコーン系粘着剤が好適である。この粘着剤層の厚さは、通常５〜１００μｍ、好ましくは１０〜６０μｍの範囲である。この粘着剤層には、必要に応じ、前述の紫外線吸収剤や光安定剤などの耐候剤を含有させることができる。
【００６３】
また、本発明の光触媒フィルムにおいては、所望により、前記粘着剤層の上に剥離シートを設けることができる。該剥離シートとしては、例えばグラシン紙、コート紙、ラミネート紙などの紙及び各種プラスチックフィルムに、シリコーン樹脂などの剥離剤を塗付したものなどが挙げられる。この剥離シートの厚さについては特に制限はないが、通常２０〜１５０μｍ程度である。このように剥離シートを設けた場合には、使用する際に該剥離シートを剥がし、粘着剤層面が被着体に接するようにして貼付すればよい。
【００６４】
図１は、本発明の光触媒フィルムの構成の１例を示す断面図であって、該光触媒フィルム１０は、基材フィルム１ａの表面に紫外線遮蔽層１ｂを有するプラスチックフィルム１上に、有機−無機複合傾斜膜２を介して光触媒活性材料層３が設けられていると共に、プラスチックフィルム１の反対側の面に、粘着剤層４を介して剥離シート５が設けられた構造を有している。
なお、紫外線遮断層１ｂはプラスチックフィルム１ａが耐久性に富む場合は必ずしも必要では無く、必要で有れば粘着剤層４とプラスチックフィルム１ａの間に紫外線遮断層１ｂを設けても良い。
【００６５】
このような本発明の光触媒フィルムは、透明であって、防汚、抗菌、脱臭機能などを有しており、例えば自動車や各種輸送機器のボディーや窓ガラス、建築物やその窓ガラス、道路の標識、ロードサイド看板、高速道路などの遮音板、カーブミラーあるいは冷凍・冷蔵ショーケースや温室などの内側に貼付することにより、その貼り付け対象物の汚れ防止、内部空間の微量有害物質の分解、およびガラス破損時の飛散防止などの効果を発揮する。
また、抗菌機能を利用して、食品包装用のラップフィルムとして、あるいは飲料水保存プラスチック容器の内面貼付用などとして用いることができる。
【００６６】
【実施例】
次に、本発明を、実施例によりさらに詳細に説明するが、本発明は、これらの例によってなんら限定されるものではない。
【００６７】
なお、基材の耐候性、中間膜の傾斜性と屈曲性、および光触媒フィルムの性能は、以下に示す方法に従って評価した。
（１）基材の耐候性
厚み５０μｍのフィルムについて、カーボンアーク式サンシャインウエザーメータによる９００時間の促進耐候試験を行い、ＪＩＳ Ｃ２３１８による引張り強度の低下率を測定した。
カーボンアーク式サンシィンウエザーメータの試験条件（ＪＩＳ Ｋ７３５０-４）
機種：スガ試験機（株）社製サンシャインウエザーメータ（Ｓ３００）
光源：２２５Ｗ／ｍ²
サイクル：照射１０２分、照射＋降雨１８分の２時間１サイクル
ブラックパネル温度：６３±３℃
相対湿度：５５±５％
【００６８】
（２）中間膜の傾斜性
ＸＰＳ装置「ＰＨＩ−５６００」［アルバック・ファイ（株）製］を用い、アルゴンスパッタリング（４ｋＶ）を３分間隔で施して膜を削り、膜表面の炭素原子と金属原子の含有率を、Ｘ線光電子分光法により測定し、傾斜性を調べた。
（３）中間膜の屈曲性
径２ｍｍのステンレス鋼製ロッドに、４ｃｍ幅の中間膜付きフィルムを、該中間膜を外側にして３６０°巻き付け、２Ｒ曲げ試験を行い、中間膜の屈曲部を（株）キーエンス社製表面形状測定顕微鏡「ＶＦ−７５００」にて２５００倍で観察し、線状クラック、剥離などの発生の有無を調べた。
【００６９】
（４）光触媒フィルムの促進耐候試験
光触媒フィルムについて、（１）基材の耐候性と同条件にてカーボンアーク式サンシャインウエザーメータによる９００時間の促進耐候試験を行い、全光線透過率およびヘイズ値の初期値と試験後の値および水接触角を測定すると共に、目視観察により干渉の発生の有無を調べた。
なお、全光線透過率ならびにヘイズ値の測定は日本電色工業（株）濁度計「ＮＤＨ２０００」にて、ＪＩＳ Ｋ７３６１に準拠する条件で行った。
水接触角の測定はエルマ販売（株）製接触角測定器「Ｇ−１−１０００」を用い、温度２５℃、湿度５０％下で測定を行った。
【００７０】
実施例１
チタンテトライソプロポキシド１２０ｇをエタノール１００ｇに溶解した溶液に、濃塩酸２５ｇ、水５ｇとエタノール５０ｇの混合溶液を撹拌しながらゆっくり滴下した。この溶液を室温で２時間撹拌し、無機成分液（ａ）を得た。
メチルメタクリレート１０．９ｇおよびγ−メタクリロキシプロピルトリメトキシシラン１．３６ｇの混合溶液に、２，２′−アゾビスイソブチロニトリル０．１ｇを溶解させた後、撹拌しながら７５℃で３時間反応させて、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）法によるポリスチレン換算の重量平均分子量が約７万の共重合体（Ａ）を得た。この共重合体１．０ｇをメチルイソブチルケトン１００ｍｌに溶解させ、１０ｇ／Ｌ濃度の有機成分溶液（ｂ）を得た。
【００７１】
メチルイソブチルケトン４０ｍｌに有機成分溶液（ｂ）１０ｍｌ、２−エトキシエタノール４０ｍｌを加えた後、無機成分液（ａ）１０ｍｌをゆっくり撹拌しながら加えて塗工液（ｃ）を調製した。
この塗工液（ｃ）を耐候剤が練り込まれたポリエチレンテレフタレート（ＰＥＴ）フィルム（帝人デュポンフィルム（株）社製テトロンＨＢ−３、５０μｍ厚）にバーコート法により上記共重合体（Ａ）の成分が０．９１４ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて中間膜としての有機−無機複合傾斜膜付きＰＥＴフィルムを得た。得られた膜の平均厚みは８３ｎｍであった。
【００７２】
なお、使用したＰＥＴフィルムの促進耐候試験による引張り強度の低下率は４５％であった。上記傾斜膜のＸＰＳ測定結果を図２に示す。この図より、傾斜性を有する膜であることが確認された。また、該傾斜膜の２Ｒ曲げ試験の結果、クラックや剥離などの異常は認められなかった。
【００７３】
次に、この傾斜膜上に、日本曹達社製「ビストレーターＬ・ＮＳＣ−２００Ｃ」のイソプロパノール１０倍重量希釈液をスピンコート法により塗工後、８０℃で１時間加熱処理することにより厚み５０ｎｍの光触媒活性材料層（以下、光触媒層と略記）を形成し、光触媒層／有機−無機複合傾斜膜付きＰＥＴフィルムからなる光触媒フィルムを作製した。
【００７４】
この光触媒フィルムについて促進耐候試験を行った結果、ヘイズ値は初期０．４％に対して１．７％、全光線透過率は初期８６．２％に対して８７．６％とほとんど変化が見られず、光触媒機能を示す水接触角は３°未満であり、干渉の発生も見られなかった。結果を表１に示す。
【００７５】
実施例２
実施例１と同様にして無機成分液（ａ）と有機成分溶液（ｂ）を得た。
メチルイソブチルケトン４０ｍｌに有機成分溶液（ｂ）６ｍｌ、２−エトキシエタノール４０ｍｌを加えた後、無機成分液（ａ）１０ｍｌをゆっくり撹拌しながら加えて塗工液（ｄ）を調製した。
【００７６】
この塗工液（ｄ）をＰＥＴフィルム（帝人デュポンフィルム（株）社製テトロンＨＢ−３、５０μｍ厚）にバーコート法により共重合体（Ａ）が０．５４８ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて有機−無機複合傾斜膜付きＰＥＴフィルムを得た。得られた膜の平均厚みは７５ｎｍであった。この傾斜膜のＸＰＳ測定結果を図３に示す。この図より、傾斜性を有する膜であることが確認された。また、該傾斜膜の２Ｒ曲げ試験の結果、クラックや剥離などの異常は認められなかった。
【００７７】
次に、実施例１と同様にして光触媒層／有機−無機複合傾斜膜付きＰＥＴフィルムからなる光触媒フィルムを作製した。
この光触媒フィルムについて促進耐候試験を行った結果、ヘイズ値は初期０．４％に対して１．９％、全光線透過率は初期８６．５％に対して８６．３％とほとんど変化が見られず、水接触角は３°未満であり、干渉の発生も見られなかった。結果を表１に示す。
【００７８】
実施例３
実施例１と同様にして無機成分液（ａ）と有機成分溶液（ｂ）を得た。
メチルイソブチルケトン２７．５ｍｌに有機成分溶液（ｂ）２２．５ｍｌ、２−エトキシエタノール４０ｍｌを加えた後、無機成分液（ａ）１０ｍｌをゆっくり撹拌しながら加えて塗工液（ｅ）を調製した。
【００７９】
この塗工液（ｅ）をＰＥＴフィルム（帝人デュポンフィルム（株）社製テトロンＨＢ−３、５０μｍ厚）にバーコート法により共重合体（Ａ）が２．０５７ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて有機−無機複合傾斜膜付きＰＥＴフィルムを得た。得られた膜の平均厚みは９０ｎｍであった。この傾斜膜のＸＰＳ測定結果を図４に示す。この図より、傾斜性を有する膜であることが確認された。また、該傾斜膜の２Ｒ曲げ試験の結果、クラックや剥離などの異常は認められなかった。
【００８０】
次に、実施例１と同様にして光触媒層／有機−無機複合傾斜膜付きＰＥＴフィルムからなる光触媒フィルムを作製した。
この光触媒フィルムについて促進耐候試験を行った結果、ヘイズ値は初期０．４％に対して１．９％、全光線透過率は初期８７．５％に対して８６．５％とほとんど変化が見られず、水接触角は６°であり、干渉の発生も見られなかった。結果を表１に示す。
【００８１】
実施例４
実施例１と同様にして無機成分液（ａ）と有機成分溶液（ｂ）を得た。
メチルイソブチルケトン４０ｍｌに有機成分溶液（ｂ）１０ｍｌ、２−エトキシエタノール４５．０ｍｌを加えた後、無機成分液（ａ）５．０ｍｌをゆっくり撹拌しながら加えて塗工液（ｆ）を調製した。
【００８２】
この塗工液（ｆ）をＰＥＴフィルム（帝人デュポンフィルム（株）社製テトロンＨＢ−３、５０μｍ厚）にバーコート法により共重合体（Ａ）が０．９１４ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて有機−無機複合傾斜膜付きＰＥＴフィルムを得た。得られた膜の平均厚みは４５ｎｍであった。この傾斜膜のＸＰＳ測定結果を図５に示す。この図より、傾斜性を有する膜であることが確認された。また、該傾斜膜の２Ｒ曲げ試験の結果、クラックや剥離などの異常は認められなかった。
【００８３】
次に、実施例１と同様にして光触媒層／有機−無機複合傾斜膜付きＰＥＴフィルムからなる光触媒フィルムを作製した。
この光触媒フィルムについて促進耐候試験を行った結果、ヘイズ値は初期０．４％に対して１．５％、全光線透過率は初期９０．２％に対して８７．５％とほとんど変化が見られず、水接触角は８°であり、干渉の発生も見られなかった。結果を表１に示す。
【００８４】
実施例５
実施例１と同様にして無機成分液（ａ）と有機成分溶液（ｂ）を得た。
メチルイソブチルケトン４０ｍｌに有機成分溶液（ｂ）１０ｍｌ、２−エトキシエタノール３７．５ｍｌを加えた後、無機成分液（ａ）１２．５ｍｌをゆっくり撹拌しながら加えて塗工液（ｇ）を調製した。
【００８５】
この塗工液（ｇ）をＰＥＴフィルム（帝人デュポンフィルム（株）社製テトロンＨＢ−３、５０μｍ厚）にバーコート法により共重合体（Ａ）が０．９１４ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて有機−無機複合傾斜膜付きＰＥＴフィルムを得た。得られた膜の平均厚みは９５ｎｍであった。この傾斜膜のＸＰＳ測定結果を図６に示す。この図より、傾斜性を有する膜であることが確認された。また、該傾斜膜の２Ｒ曲げ試験の結果、クラックや剥離などの異常は認められなかった。
【００８６】
次に、実施例１と同様にして光触媒層／有機−無機複合傾斜膜付きＰＥＴフィルムからなる光触媒フィルムを作製した。
この光触媒フィルムについて促進耐候試験を行った結果、ヘイズ値は初期０．６％に対して１．７％、全光線透過率は初期８５．７％に対して８４．２％とほとんど変化が見られず、水接触角は３°未満であり、干渉の発生も見られなかった。結果を表１に示す。
【００８７】
実施例６
実施例１と同様にして無機成分液（ａ）と有機成分溶液（ｂ）を混合、撹拌し塗工液（ｃ）を調製した。
また、東レ社製ＰＥＴフィルム「ルミラーＴ−６０」５０μｍ厚の片面に、紫外線吸収プライマー（日本触媒社製「ユーダブルＵＶ−Ｇ３００」１００ｇ当量とイソシアネート系硬化剤住友バイエルウレタン社製「スミジュールＮ−３２００」１３ｇ当量を混合し、４μｍ厚みで成膜した。この耐候性プライマー層上に塗工液（ｃ）を実施例１と同様に共重合体（Ａ）が０．９１４ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて有機−無機複合傾斜膜付きＰＥＴフィルムを得た。得られた膜の平均厚みは８４ｎｍであった。
【００８８】
なお、使用した耐候性プライマー被覆ＰＥＴフィルムの促進耐候試験による引張り強度の低下率は５％であった。上記傾斜膜のＸＰＳ測定結果を図７に示す。この図より、傾斜性を有する膜であることが確認された。また、該傾斜膜の２Ｒ曲げ試験の結果、クラックや剥離などの異常は認められなかった。
【００８９】
次に、実施例１と同様にして光触媒層／有機−無機複合傾斜膜付きＰＥＴフィルムからなる光触媒フィルムを作製した。
この光触媒フィルムについて促進耐候試験を行った結果、ヘイズ値は初期１．９％に対して２．２％、全光線透過率は初期８６．５％に対して８６．８％とほとんど変化が見られず、水接触角は６°であり、干渉の発生も見られなかった。結果を表１に示す。
【００９０】
実施例７
テトラエトキシシラン１２０ｇをエタノール１００ｇに溶解した溶液に、１モル／リットル濃度の硝酸水溶液０．７ｍｌ、水８０ｇとエタノール５０ｇの混合溶液を撹拌しながらゆっくり滴下した。この溶液を３０℃で７２時間撹拌し、無機成分液を得た。一方、実施例１と同様にして有機成分溶液（ｂ）を得た。
メチルイソブチルケトン４０ｍｌに有機成分溶液（ｂ）１０ｍｌ、１−ブタノール４０ｍｌを加えた後、上記無機成分液１０ｍｌをゆっくり撹拌しながら加えて塗工液（ｈ）を調製した。
【００９１】
この塗工液（ｈ）を実施例６で使用したのと同じ基材（耐候性プライマー被覆ＰＥＴフィルム）に実施例１と同様に有機成分が０．９１４ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて有機−無機複合傾斜膜付きＰＥＴフィルムを得た。得られた膜の平均厚みは８０ｎｍであった。
この傾斜膜のＸＰＳ測定結果を図８に示す。この図より、傾斜性を有する膜であることが確認された。また、該傾斜膜の２Ｒ曲げ試験の結果、クラックや剥離などの異常は認められなかった。
【００９２】
次に、実施例１と同様にして、光触媒層／有機−無機複合傾斜膜付きＰＥＴフィルムからなる光触媒フィルムを作製した。
この光触媒フィルムについて促進耐候試験を行った結果、ヘイズ値は初期１．７％に対して２．１％、全光線透過率は初期９０．５％に対して９０．２％とほとんど変化が見られず、水接触角は６°であり、干渉の発生も見られなかった。結果を表１に示す。
【００９３】
実施例８
実施例１と同様にして無機成分溶液（ａ）と有機成分溶液（ｂ）を混合、攪拌し塗工液（ｃ）を調製した。
また、鐘淵化学工業社製アクリルフィルム「サンデュレンＳＤ００９ＮＡＴ」５０μｍ厚の片面に、紫外線吸収プライマー（日本触媒社製「ユーダブルＵＶ−Ｇ３００」）１００ｇ当量とイソシアネート系硬化剤住友バイエル社製「スミジュールＮ−３２００」１３ｇ当量を混合し、1μm厚みで成膜した。得られたプライマー層上に塗工液（ｃ）を実施例１と同様に共重合体（Ａ）が０．９１４ｇ／１００ｍ²となるように塗工し、その後６０℃で１５時間乾燥させて有機―無機複合傾斜膜付きアクリルフィルムを得た。得られた膜の平均厚みは７５ｎｍであった。
【００９４】
なお、使用したプライマー被覆アクリルフィルムの促進耐候試験による引っ張り強度の低下率は４％であった。上記傾斜膜のＸＰＳ測定結果を図９に示す。
この図より、傾斜性を有する膜であることが確認された。また、該傾斜膜の２Ｒ曲げ試験の結果、クラックや剥離などの異常は認められなかった。
【００９５】
次に、実施例１と同様にして光触媒層／有機―無機複合傾斜膜付きアクリルフィルムからなる光触媒フィルムを作製した。
この光触媒フィルムについて促進耐候試験（９００時間）を行った結果、ヘイズ値は初期０．９％に対して、１．３％、全光線透過率は初期９１．５％に対して９１．１％とほとんど変化が見られず、水接触角は３°未満であり、干渉の発生も見られなかった。結果を表１に示す。
【００９６】
実施例９
実施例１と同様にして無機成分溶液（ａ）と有機成分溶液（ｂ）を混合、攪拌し塗工液（ｃ）を調製した。
また、三菱エンジニアリングプラスチックス社製ポリカーボネートフィルム「ユーピロンフィルムＦＥ２０００」１００μｍ厚の片面に、紫外線吸収プライマー（日本触媒社製「ユーダブルＵＶ−Ｇ３００」）１００ｇ当量とイソシアネート系硬化剤住友バイエル社製「スミジュールＮ−３２００」１３ｇ当量を混合し、４μｍ厚みで成膜した。得られたプライマー層上に塗工液（ｃ）を実施例１と同様に共重合体（Ａ）が０．９１４ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて有機―無機複合傾斜膜付きポリカーボネートフィルムを得た。得られた膜の平均厚みは７８ｎｍであった。
【００９７】
なお、使用したプライマー被覆ポリカーボネートフィルムの促進耐候試験による引っ張り強度の低下率は９%であった。上記傾斜膜のＸＰＳ測定結果を図１０に示す。
この図より、傾斜性を有する膜であることが確認された。また、該傾斜膜の２Ｒ曲げ試験の結果、クラックや剥離などの異常は認められなかった。
【００９８】
次に、実施例１と同様にして光触媒層／有機―無機複合傾斜膜付きポリカーボネートフィルムからなる光触媒フィルムを作製した。
この光触媒フィルムについて促進耐候試験（９００時間）を行った結果、ヘイズ値は初期１．３％に対して、２．５％、全光線透過率は初期９０．５％に対して９０．２％とほとんど変化が見られず、水接触角は３°未満であり、干渉の発生も見られなかった。結果を表１に示す。
【００９９】
比較例１
市販のアクリルシリコーン系塗工液を用い、実施例１と同様な操作により、ＰＥＴフィルムに厚み４μｍの中間膜を形成し、中間膜付きＰＥＴフィルムを得た。この中間膜の２Ｒ曲げ試験の結果、クラックや剥離などの異常は認められなかった。
【０１００】
次に、実施例１と同様な操作により、光触媒層／中間膜付きＰＥＴフィルムからなる光触媒フィルムを作製した。
この光触媒フィルムについて促進耐候試験を行った結果、ヘイズ値は初期２．７％に対して５．５％、全光線透過率は初期８８．６％に対して８１．３％と比較的大きな透光性の低下が見られた。また、水接触角は８°であったが、干渉の発生が見られた。結果を表１に示す。
【０１０１】
比較例２
実施例１と同様にして無機成分液（ａ）と有機成分溶液（ｂ）を得た。
メチルイソブチルケトン４５ｍｌに有機成分溶液（ｂ）４．４ｍｌ、２−エトキシエタノール４５．６ｍｌを加えた後、無機成分液（ａ）１０ｍｌをゆっくり撹拌しながら加えて塗工液（ｉ）を調製した。
【０１０２】
この塗工液（ｉ）を実施例１と同様に有機成分（Ａ）が０．４０ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて有機−無機複合傾斜膜付きＰＥＴフィルムを得た。得られた傾斜膜の平均厚みは７０ｎｍであった。この傾斜膜の２Ｒ曲げ試験の結果、クラックや剥離が見られた。結果を表１に示す。
【０１０３】
比較例３
実施例１と同様にして無機成分液（ａ）と有機成分溶液（ｂ）を得た。
メチルイソブチルケトン１５ｍｌに有機成分溶液（ｂ）３５ｍｌ、２−エトキシエタノール４３ｍｌを加えた後、無機成分液（ａ）７ｍｌをゆっくり撹拌しながら加えて塗工液（ｊ）を調製した。
【０１０４】
この塗工液（ｊ）を実施例１と同様に有機成分（Ａ）が３．２ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて理論厚み８０ｎｍの有機−無機複合傾斜膜付きＰＥＴフィルムを得た。乾燥後の塗工膜は白濁しており、表面を顕微鏡で観察したところ凹凸が多数見られた。結果を表１に示す。
【０１０５】
比較例４
実施例１と同様にして無機成分液（ａ）と有機成分溶液（ｂ）を得た。
メチルイソブチルケトン４０ｍｌに有機成分溶液（ｂ）１０ｍｌ、２−エトキシエタノール４８ｍｌを加えた後、無機成分液（ａ）２ｍｌをゆっくり撹拌しながら加えて塗工液（ｋ）を調製した。
【０１０６】
この塗工液（ｋ）を実施例１と同様に有機成分（Ａ）が０．９１４ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて有機−無機複合傾斜膜付きＰＥＴフィルムを得た。得られた傾斜膜の平均厚みは３５ｎｍであった。この傾斜膜の２Ｒ曲げ試験の結果、クラックや剥離などの異常は認められなかった。
【０１０７】
次に、実施例１と同様にして光触媒層／有機−無機複合傾斜膜付きのＰＥＴフィルムからなる光触媒フィルムを作製した。
この光触媒フィルムについて促進耐候試験を行った結果、ヘイズ値は初期２．７％に対して１０．５％、全光線透過率は初期８８．６％に対して７８．３％と透光性の低下が見られ、かつ干渉の発生および水接触角が７０°となる現象が見られた。結果を表１に示す。
【０１０８】
比較例５
実施例１と同様にして無機成分液（ａ）と有機成分溶液（ｂ）を得た。
メチルイソブチルケトン４０ｍｌに有機成分溶液（ｂ）１０ｍｌ、２−エトキシエタノール３５ｍｌを加えた後、無機成分液（ａ）１５ｍｌをゆっくり撹拌しながら加えて塗工液（ｍ）を調製した。
【０１０９】
この塗工液（ｍ）を実施例１と同様に有機成分（Ａ）が０．９１４ｇ／１００ｍ²となるように塗工し、その後８０℃で１５時間乾燥させて有機−無機複合傾斜膜付きＰＥＴフィルムを得た。得られた傾斜膜の平均厚みは１０５ｎｍであった。この傾斜膜の２Ｒ曲げ試験の結果、クラックの発生が見られた。結果を表１に示す。
【０１１０】
【表１】

【０１１１】
【発明の効果】
本発明の光触媒フィルムは、プラスチックフィルム上に、有機−無機複合傾斜膜を介して光触媒活性材料層が設けられたものであって、層間密着性、耐候性、屈曲性などに優れており、従来の光触媒フィルムの耐久性が１〜３年程度であるのに対し、３年以上の耐久性を有している。
【図面の簡単な説明】
【図１】本発明の光触媒フィルムの構成の１例を示す断面図である。
【図２】実施例１で形成された有機−無機複合傾斜膜におけるスパッタリング時間と炭素原子およびチタン原子の含有率との関係を示すグラフである。
【図３】実施例２で形成された有機−無機複合傾斜膜におけるスパッタリング時間と炭素原子およびチタン原子の含有率との関係を示すグラフである。
【図４】実施例３で形成された有機−無機複合傾斜膜におけるスパッタリング時間と炭素原子およびチタン原子の含有率との関係を示すグラフである。
【図５】実施例４で形成された有機−無機複合傾斜膜におけるスパッタリング時間と炭素原子およびチタン原子の含有率との関係を示すグラフである。
【図６】実施例５で形成された有機−無機複合傾斜膜におけるスパッタリング時間と炭素原子およびチタン原子の含有率との関係を示すグラフである。
【図７】実施例６で形成された有機−無機複合傾斜膜におけるスパッタリング時間と炭素原子およびチタン原子の含有率との関係を示すグラフである。
【図８】実施例７で形成された有機−無機複合傾斜膜におけるスパッタリング時間と炭素原子およびケイ素原子の含有率との関係を示すグラフである。
【図９】実施例８で形成された有機−無機複合傾斜膜におけるスパッタリング時間と炭素原子およびケイ素原子の含有率との関係を示すグラフである。
【図１０】実施例９で形成された有機−無機複合傾斜膜におけるスパッタリング時間と炭素原子およびケイ素原子の含有率との関係を示すグラフである。
【符号の説明】
１ プラスチックフィルム
１ａ 基材フィルム
１ｂ 紫外線遮蔽層
２ 有機−無機複合傾斜膜
３ 光触媒活性材料層
４ 粘着剤層
５ 剥離シート
１０ 光触媒フィルム[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photocatalyst film, and more specifically, has a photocatalytically active material layer on the surface of a base film through an organic-inorganic composite gradient film, and has weather resistance, transparency, interlayer adhesion, flexibility, etc. The present invention relates to a photocatalyst film useful for various applications as a functional film that exhibits excellent photocatalytic function.
[0002]
[Prior art]
A photocatalytically active material (hereinafter sometimes simply referred to as a photocatalyst) is excited to produce electrons in the conduction band and holes in the valence band when irradiated with light having energy higher than its band gap. The generated electrons reduce the surface oxygen to form a superoxide anion (.O^2-), And the holes oxidize hydroxyl groups on the surface to generate hydroxyl radicals (.OH). These reactive active oxygen species exert a strong oxidative decomposition function and adhere to the surface of the photocatalyst. It is known to decompose organic substances with high efficiency.
By applying such photocatalytic functions, for example, deodorization, antifouling, antibacterial, sterilization, and decomposition / removal of various substances that cause environmental pollution in wastewater and waste gas are being studied. Yes.
[0003]
Further, as another function of the photocatalyst, when the photocatalyst is photoexcited, for example, as disclosed in International Patent Publication No. 96/29375, the photocatalyst surface has a contact angle with water of 10 degrees or less. It is also known to express superhydrophilization. Applying such a superhydrophobic function of photocatalysts, for example, for preventing pollution caused by tin in automobile exhaust gas for soundproof walls of highways, lighting in tunnels, street lights, etc. The use of photocatalysts for mirror films, antifogging and self-cleaning window glass has been studied.
[0004]
As such photocatalysts, compounds having various semiconductor characteristics such as metal oxides such as titanium dioxide, iron oxide, tungsten oxide and zinc oxide, and metal sulfides such as cadmium sulfide and zinc sulfide have been known. However, among these, titanium dioxide, particularly anatase titanium dioxide, is useful as a practical photocatalyst. This titanium dioxide exhibits excellent photocatalytic activity by absorbing light of a specific wavelength in the ultraviolet region contained in daily light such as sunlight.
[0005]
When a layer made of a photocatalyst is provided on an organic base material such as plastic, if the photocatalyst is directly coated, there arises a problem that the organic base material is inevitably deteriorated in a short time by the photocatalytic action. Therefore, for example, in a photocatalyst film having a photocatalyst layer on a plastic film, an intermediate layer is usually provided to prevent deterioration of the base film due to photocatalytic action and to improve adhesion to the base film. . As this intermediate layer, a layer made of silicone resin, acrylic-modified silicone resin or the like and having a thickness of about several μm is generally used.
[0006]
However, such a photocatalytic film deteriorates in about 1 to 3 years, and there arises a problem that transparency is lowered due to film interference, and antifouling property is lowered. As a cause of this deterioration, since the intermediate layer has an organic substituent, the organic component is decomposed by the photocatalytic action, and as a result, a crack occurs in the intermediate layer, and the photocatalytic layer and the intermediate layer, or the intermediate layer It seems that interference occurs due to floating or partial peeling at the interface with the base film. Moreover, since this photocatalyst film has a thick intermediate layer of about several μm, there is a problem in that partial interfacial peeling or loss is likely to occur due to deflection or bending of the film itself, and interference is likely to occur.
[0007]
On the other hand, the present inventors previously provided various uses as a novel functional material such as a coating film, an adhesive between an organic material and an inorganic or metal material, and an organic substrate and a photocatalytic coating film. Is useful for applications such as an intermediate film that prevents deterioration of the organic base material, and an intermediate film that improves the adhesion between the organic base material and the inorganic or metal-based material layer. A changing organic-inorganic composite gradient material was found (Japanese Patent Application No. 11-264592).
[0008]
This organic-inorganic composite gradient material is an organic-inorganic composite material containing a chemical bond between an organic polymer compound and a metal compound, and the content of the metal compound is continuously in the thickness direction of the material. It has a changing component gradient structure and is a novel material useful for the various applications described above.
[0009]
[Problems to be solved by the invention]
The present invention provides a photocatalytic film useful for various applications as a functional film that solves the problems of conventional photocatalytic films and is excellent in weather resistance, transparency, interlayer adhesion, flexibility, etc., and exhibits a photocatalytic function. It is intended to do.
[0010]
[Means for Solving the Problems]
As a result of intensive studies to develop a photocatalytic film having the above-mentioned excellent characteristics, the present inventors have used a plastic film as a base material and have the above-mentioned organic-inorganic having a specific thickness and properties on one side. It has been found that a photocatalytic film having a photocatalytically active material layer via a composite gradient film can be adapted to the purpose, and the present invention has been completed based on this finding.
[0011]
  That is, the present invention is a photocatalytic film having a photocatalytically active material layer on one side of a plastic film via an organic-inorganic composite gradient film,
  The plastic film is a film kneaded with a weathering agent or a film having an ultraviolet shielding layer on the surface of the organic-inorganic composite gradient film side,
  The organic-inorganic composite gradient film is (A) a metal capable of forming a metal oxide by hydrolysis together with (A) an organic polymer compound having a metal-containing group capable of binding to the metal oxide by hydrolysis. The coating agent formed by hydrolyzing the contained compound is 0.5 to 3.0 g / 100 m in terms of component (A). ² It was formed by coating so that
  in frontThe organic-inorganic composite gradient film has an average thickness of 40 to 100 nm, and substantially no cracks are observed in a 2R bending test in which a stainless steel rod having a diameter of 2 mm is wound 360 °. The photocatalyst film characterized by the above is provided.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
In the photocatalytic film of the present invention, a plastic film is used as a substrate. Here, as a plastic film, a film having a thickness reduction rate of 50% or less according to JIS C231 is preferably used in a 900-hour accelerated weathering test using a carbon arc sunshine weather meter for a film having a thickness of 50 μm.
[0013]
Examples of the resin constituting the plastic film include acrylic resins such as polymethyl methacrylate, styrene resins such as polystyrene and ABS resins, olefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, Polyamide resins such as 6-nylon and 6,6-nylon, polyvinyl chloride resins, polycarbonate resins, polyphenylene sulfide resins, polyphenylene ether resins, polyimide resins, cellulose resins such as cellulose acetate, polyvinylidene fluoride And fluorine resins such as fluorinated ethylene-propylene copolymer and fluorinated ethylene-ethylene copolymer. These resins may be used alone or in combination of two or more.
[0014]
The plastic film in the present invention is not particularly limited as long as it has weather resistance satisfying the above-described conditions. For example, (1) a film made of a weather resistant resin, (2) a film kneaded with a weather resistant agent, and ( 3) Any of the film which has an ultraviolet-ray shielding layer only on the surface by the side of an organic-inorganic composite gradient film or both surfaces may be sufficient.
[0015]
In addition, even if it is a film consisting of a weather resistant resin, a weather resistance agent may be kneaded into the film if desired, or an ultraviolet shielding layer may be provided on the film surface. Moreover, even if it is a film kneaded with a weathering agent, an ultraviolet shielding layer may be provided on the film surface as desired.
[0016]
Among the plastic films, examples of the film made of the weather resistant resin (1) include acrylic resin films such as polymethyl methacrylate, polyester resin films such as polyethylene terephthalate and polyethylene naphthalate, polycarbonate resin films, and cellulose acetate. Preferred examples include cellulose resin films such as fluorinated resin films such as polyvinylidene fluoride.
[0017]
In the film in which the weathering agent (2) is kneaded, an ultraviolet absorber and / or a light stabilizer can be used as the weathering agent. Here, the ultraviolet absorber absorbs ultraviolet rays having high energy, converts to low energy, suppresses generation of radicals, and prevents the plastic film from being deteriorated. On the other hand, the light stabilizer is ultraviolet rays. It has a function of preventing the plastic film from deteriorating by binding to the radicals generated by the reaction to prevent the chain reaction.
[0018]
In general, the ultraviolet absorbers can be broadly classified into salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, and others.
Examples of salicylate ultraviolet absorbers include phenyl salicylate, p-octylphenyl salicylate, pt-butylphenyl salicylate and the like. Examples of benzophenone ultraviolet absorbers include 2,2'-dihydroxy-4- Methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2- And hydroxy-4-octoxybenzophenone. Examples of benzotriazole ultraviolet absorbers include 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3). '-Tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-amyl-5'-isobutylphenyl) -5-chlorobenzotriazole, 2- ( 2'-hydroxy-3'-isobutyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-isobutyl-5'-propylphenyl) -5-chlorobenzotriazole, 2 -(2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-5' Methylphenyl) bendriazole, 2- [2′-hydroxy-5 ′-(1,1,3,3-tetramethyl) phenyl] benzotriazole, and the like. Examples of substituted acrylonitrile-based ultraviolet absorbers include: Examples include ethyl 2-cyano-3,3-diphenylacrylate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, and the like. Further, as other ultraviolet absorbers, for example, resorcinol monobenzoate, 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, N- (2-ethylphenyl) -N '-(2-Ethoxy-5-t-butylphenyl) succinic acid diamide and the like can be mentioned. These ultraviolet absorbers may be used alone or in combination of two or more.
[0019]
The light stabilizer is preferably a hindered amine type, such as bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, dimethyl-1- (2-hydroxyethyl) -4-hydroxy succinate. -2,2,6,6-tetramethylpiperidine polycondensate, poly [6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [ (2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [2,2,6,6-tetramethyl-4-piperidyl) imide], tetrakis (2,2,6,6-tetra Methyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, 2,2,6,6-tetramethyl-4-piperidylbenzoate, bis (1,2,6,6-pentamethyl-4 Piperidyl) -2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate, bis (N-methyl-2,2,6,6-tetramethyl-4-piperidyl) ) Sebacate, 1,1 '-(1,2-ethanediyl) bis (3,3,5,5-tetramethylpiperazine), (mixed 2,2,6,6-tetramethyl-4-piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate, (mixed 1,2,2,6,6-pentamethyl-4-piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate, mix [2,2,6,6-tetramethyl-4-piperidyl / β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5 ) Undecane] diethyl] -1 , 2,3,4-butanetetracarboxylate, mixed [1,2,2,6,6-pentamethyl-4-piperidyl / β, β, β ′, β′-tetramethyl-3,9- [2 , 4,8,10-tetraoxaspiro (5,5) undecane] diethyl] -1,2,3,4-butanetetracarboxylate, N, N'-bis (3-aminopropyl) ethylenediamine-2,4 -Bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, poly [6-N-morpholyl -1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4 -Piperidyl) imide], N, N′-bis ( , 2,6,6-tetramethyl-4-piperidyl) condensate of hexamethylenediamine and 1,2-dibromoethane, [N- (2,2,6,6-tetramethyl-4-piperidyl) -2 -Methyl-2- (2,2,6,6-tetramethyl-4-piperidyl) imino] propionamide and the like. These light stabilizers may be used alone or in combination of two or more, and can also be used in combination with the ultraviolet absorber.
[0020]
Further, in the plastic film having an ultraviolet shielding layer on the surface of (3), the ultraviolet shielding layer is a layer comprising an appropriate binder and an ultraviolet shielding material contained therein, and may have a single layer structure. It may have a laminated structure of two or more layers. Examples of the ultraviolet shielding material include at least one selected from an ultraviolet absorber and an ultraviolet scattering agent. By providing the layer containing these ultraviolet shielding materials, the ultraviolet rays are effectively blocked and the deterioration of the base film due to the ultraviolet rays is suppressed.
As said ultraviolet absorber, the same thing as what was illustrated in description of the ultraviolet absorber in the above-mentioned weathering agent can be mentioned. This ultraviolet absorber may be used individually by 1 type, may be used in combination of 2 or more type, and may be used in combination with the above-mentioned light stabilizer as needed.
[0021]
On the other hand, an ultraviolet scattering agent is a material that provides an ultraviolet blocking effect by scattering ultraviolet rays, and inorganic materials such as metal oxide powders are mainly used. Examples of this ultraviolet light scattering agent include powders obtained by micronizing titanium dioxide, zinc oxide, cerium oxide, etc., hybrid inorganic powders obtained by complexing titanium dioxide microparticles with iron oxide, and the surface of cerium oxide microparticles being non-coated. Examples thereof include a hybrid inorganic powder coated with crystalline silica. Since the ultraviolet scattering effect is greatly affected by the particle diameter, in the present invention, the average particle diameter of the ultraviolet scattering agent is preferably 5 μm or less, and particularly preferably in the range of 10 nm to 2 μm. In the case where the ultraviolet scattering agent has photocatalytic activity, it is preferable to use a material in which the particle surface is thinly coated with water glass or the like to eliminate photocatalytic activity.
[0022]
The ultraviolet shielding layer in the present invention may have a single-layer structure containing at least one selected from the above-mentioned ultraviolet absorber and ultraviolet scattering agent, and includes a layer containing an ultraviolet absorber and an ultraviolet scattering agent. A layered structure in which two or more layers are stacked may be used.
[0023]
Moreover, there is no restriction | limiting in particular as content of this ultraviolet shielding material in an ultraviolet shielding layer, Although it selects suitably according to the kind of ultraviolet shielding material, the kind of base film, etc., Usually 0.01 to 10 weight %, Preferably in the range of 0.05 to 5% by weight. When the ultraviolet shielding material is an ultraviolet scattering agent, the content thereof is preferably in the range of 0.1 to 10% by weight, particularly preferably in the range of 1 to 5% by weight. On the other hand, when the ultraviolet shielding material is an ultraviolet absorber, the content thereof is preferably in the range of 0.01 to 10% by weight, particularly preferably in the range of 0.05 to 5% by weight.
[0024]
As the binder used for forming the ultraviolet shielding layer, an organic binder is preferable because an organic-inorganic composite gradient film is provided on the ultraviolet shielding layer. There is no restriction | limiting in particular as an organic type binder, A conventionally well-known thing, for example, acrylic resin, polyester-type resin, a polyurethane-type resin, a butyral-type resin etc., Furthermore, the hardened | cured material of an ultraviolet curable resin etc. can be mentioned.
[0025]
The ultraviolet shielding layer in the present invention is prepared by preparing a coating solution containing the binder and the ultraviolet shielding material, and conventionally known methods such as bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating. It can be formed by coating on a plastic film of a substrate using a method, etc., and curing by heating or irradiating with ultraviolet rays. The thickness of this ultraviolet shielding layer is usually in the range of 0.1 to 20 μm, preferably 0.5 to 10 μm.
[0026]
In the present invention, the base plastic film having a thickness of usually 500 to 20 μm, preferably 200 to 30 μm is used.
When this plastic film is a film made of a weathering resin as described above or a film kneaded with a weathering agent, an organic-inorganic composite gradient film provided on the surface thereof, or an adhesive layer provided on the back surface if desired, For the purpose of improving the adhesiveness, surface treatment can be applied to one surface or both surfaces by an oxidation method or an unevenness method, if desired. Examples of the oxidation method include corona discharge treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment and the like, and examples of the unevenness method include sand blast method and solvent treatment method. Is mentioned. These surface treatment methods are appropriately selected according to the type of the base film, but generally, the corona discharge treatment method is preferably used from the viewpoints of effects and operability.
[0027]
In addition, when the plastic film has an ultraviolet shielding layer on the surface, for the purpose of improving the adhesion between the base film and the ultraviolet shielding layer or the adhesive layer provided on the back surface if desired, If desired, one or both surfaces of the base film can be subjected to a surface treatment by the oxidation method or the unevenness method as described above.
[0028]
In the photocatalytic film of the present invention, an organic-inorganic composite gradient film is first provided on one side of the plastic film thus obtained. This organic-inorganic composite gradient film is provided directly on the film when the plastic film to be used does not have an ultraviolet shielding layer on the surface, and on the ultraviolet shielding layer when it has an ultraviolet shielding layer.
[0029]
The organic-inorganic composite gradient film includes a complex in which an organic polymer compound and a metal oxide compound are chemically bonded, and the content of the metal component continuously changes in the thickness direction of the film. It has an inclined structure. Such a composite gradient film includes (A) an organic polymer compound having a metal-containing group (hereinafter sometimes referred to as a hydrolyzable metal-containing group) that can be bonded to a metal oxide by hydrolysis in the molecule. (B) It can form using the coating agent formed by hydrolyzing the metal containing compound which can form a metal oxide by hydrolysis.
The organic polymer compound having a hydrolyzable metal-containing group as the component (A) includes, for example, (a) an ethylenically unsaturated monomer having a hydrolyzable metal-containing group, and (b) an ethylenic material not containing a metal. It can be obtained by copolymerizing unsaturated monomers.
[0030]
Examples of the ethylenically unsaturated monomer having a hydrolyzable metal-containing group as the component (A) (a) include those represented by the general formula (II)
[0031]
[Chemical 2]

(Wherein R^ThreeIs a hydrogen atom or a methyl group, A is an alkylene group, preferably an alkylene group having 1 to 4 carbon atoms, R^FourIs a hydrolyzable group or a non-hydrolyzable group, and at least one of them must be a hydrolyzable group capable of chemically bonding to the component (B) by hydrolysis, and R^FourIf there are multiple, each R^FourMay be the same or different, M²Is a metal atom such as silicon, titanium, zirconium, indium, tin, aluminum, and k is a metal atom M²Is the valence of. )
The group represented by these can be mentioned.
[0032]
In the general formula (II), R^FourExamples of the hydrolyzable group that can be chemically bonded to the component (B) by hydrolysis include an alkoxyl group, an isocyanate group, a halogen atom such as a chlorine atom, an oxyhalogen group, an acetylacetonate group, and a hydroxyl group. On the other hand, preferred examples of the non-hydrolyzable group that does not chemically bond to the component (B) include a lower alkyl group.
[0033]
-M in general formula (II)²R^Four _k-1As the metal-containing group represented by, for example, trimethoxysilyl group, triethoxysilyl group, tri-n-propoxysilyl group, triisopropoxysilyl group, tri-n-butoxysilyl group, triisobutoxysilyl group, Tri-sec-butoxysilyl group, tri-tert-butoxysilyl group, trichlorosilyl group, dimethylmethoxysilyl group, methyldimethoxysilyl group, dimethylchlorosilyl group, methyldichlorosilyl group, triisocyanatosilyl group, methyldiisocyanato Silyl group, trimethoxytitanium group, triethoxytitanium group, tri-n-propoxytitanium group, triisopropoxytitanium group, tri-n-butoxytitanium group, triisobutoxytitanium group, tri-sec-butoxytitanium group, Tri-te t-butoxytitanium group, trichlorotitanium group, trimethoxyzirconium group, triethoxyzirconium group, tri-n-propoxyzirconium group, triisopropoxyzirconium group, tri-n-butoxyzirconium group, triisobutoxyzirconium group , Tri-sec-butoxyzirconium group, tri-tert-butoxyzirconium group, trichlorozirconium group, and further dimethoxyaluminum group, diethoxyaluminum group, di-n-propoxyaluminum group, diisopropoxyaluminum group, di- Examples include n-butoxyaluminum group, diisobutoxyaluminum group, di-sec-butoxyaluminum group, di-tert-butoxyaluminum group, trichloroaluminum group and the like.
One type of the ethylenically unsaturated monomer of component (a) may be used, or two or more types may be used in combination.
[0034]
On the other hand, as the ethylenically unsaturated monomer that does not contain a metal as the component (b), for example, the general formula (III)
[0035]
[Chemical 3]

(Wherein R^FiveIs a hydrogen atom or a methyl group, and X is a monovalent organic group. )
An ethylenically unsaturated monomer represented by formula (III-a)
[0036]
[Formula 4]

(Wherein R^FiveIs the same as above and R⁶Represents a hydrocarbon group. )
Or an ethylenically unsaturated monomer represented by the above general formula (III-a), and a general formula ( III-b)
[0037]
[Chemical formula 5]

(Wherein R⁷Is a hydrogen atom or a methyl group, R⁸Represents an epoxy group, a halogen atom or a hydrocarbon group having an ether bond. )
And a mixture with an ethylenically unsaturated monomer represented by the formula:
[0038]
In the ethylenically unsaturated monomer represented by the general formula (III-a), R⁶As a hydrocarbon group shown by C1-C10 linear or branched alkyl group, C3-C10 cycloalkyl group, C6-C10 aryl group, C7-C10 Preferred examples include aralkyl groups. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and various butyl groups, pentyl groups, hexyl groups, octyl groups, and decyl groups. Examples of the cycloalkyl group having 3 to 10 carbon atoms include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and a cyclooctyl group. Examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, a tolyl group, and a xylyl group. Examples of the aralkyl group having 7 to 10 carbon atoms, such as a group, a naphthyl group, and a methylnaphthyl group, include a benzyl group, a methylbenzyl group, a phenethylyl group, and a naphthylmethyl group.
[0039]
Examples of the ethylenically unsaturated monomer represented by the general formula (III-a) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl ( Examples include meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, and benzyl (meth) acrylate. These may be used alone or in combination of two or more.
[0040]
In the ethylenically unsaturated monomer represented by the general formula (III-b), R⁸As an epoxy group, a halogen atom or a hydrocarbon group having an ether bond, a linear or branched alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or 6 to 10 carbon atoms. And an aryl group having 7 to 10 carbon atoms can be preferably mentioned. The halogen atom for the substituent is preferably a chlorine atom or a bromine atom. Specific examples of the hydrocarbon group include R in the general formula (III-a).⁶And the same groups as those exemplified in the description of.
[0041]
Examples of the ethylenically unsaturated monomer represented by the general formula (III-b) include glycidyl (meth) acrylate, 3-glycidoxypropyl (meth) acrylate, and 2- (3,4-epoxycyclohexyl). ) Ethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-bromoethyl (meth) acrylate and the like can be preferably exemplified.
[0042]
In addition to these, the ethylenically unsaturated monomer represented by the general formula (III) includes styrene, α-methylstyrene, α-acetoxystyrene, m-, o- or p-bromostyrene, m -, O- or p-chlorostyrene, m-, o- or p-vinylphenol, 1- or 2-vinylnaphthalene and the like, and stabilizers for polymerizable polymers having an ethylenically unsaturated group, for example, ethylenic Antioxidants, ultraviolet absorbers and light stabilizers having an unsaturated group can also be used. These may be used alone or in combination of two or more. When the ethylenically unsaturated monomer represented by the general formula (III-a) and the ethylenically unsaturated monomer represented by the general formula (III-b) are used in combination, the former ethylenic monomer It is preferable to use the latter ethylenically unsaturated monomer in a proportion of 1 to 100 mol% with respect to the unsaturated monomer.
In the presence of a radical polymerization initiator, an ethylenically unsaturated monomer having a hydrolyzable metal-containing group as the component (a) and an ethylenically unsaturated monomer having no metal as the component (b) By copolymerization, an organic polymer compound having a hydrolyzable metal-containing group as component (A) is obtained.
[0043]
On the other hand, as the metal-containing compound (hydrolyzable metal-containing compound) capable of forming a metal oxide by hydrolysis of the component (B), the general formula (I)
[0044]
[Chemical 6]

(R in the formula¹Is a non-hydrolyzable group, R²Is a hydrolyzable group, M¹Represents a metal atom, m represents a metal atom M¹N is an integer that satisfies the relationship 0 <n ≦ m. )
Or a condensed oligomer thereof is used.
[0045]
In the above general formula (I), R¹If there are multiple, then multiple R¹May be the same or different and R²If there are multiple, multiple R²May be the same or different. R¹As the non-hydrolyzable group represented by, for example, an alkyl group, an aryl group, an alkenyl group and the like are preferably exemplified.²Examples of the hydrolyzable group represented by the formula include a hydroxyl atom, an alkoxyl group, an isocyanate group, a halogen atom such as a chlorine atom, an oxyhalogen group, and an acetylacetonate group. M¹Examples of the metal atom represented by are silicon, titanium, zirconium, indium, tin, and aluminum.
[0046]
Examples of the compound represented by the general formula (I) or a condensed oligomer thereof include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, and tetraisobutoxysilane. , Tetra-sec-butoxysilane, tetra-tert-butoxysilane, etc., and tetraalkoxytitanium and tetraalkoxyzirconium corresponding to these, trimethoxyaluminum, triethoxyaluminum, tri-n-propoxyaluminum, triisopropoxyaluminum Metal alkoxides such as tri-n-butoxyaluminum, triisobutoxyaluminum, tri-sec-butoxyaluminum and tri-tert-butoxyaluminum Metal alkoxide oligomers, for example, commercially available alkoxysilane oligomers “methyl silicate 51”, “ethyl silicate 40” (both trade names manufactured by Colcoat Co.), “MS-51”, “MS-56” (all Mitsubishi Chemical) In addition, tetraisocyanatosilane, methyltriisocyanatosilane, tetrachlorosilane, methyltrichlorosilane, and the like can be mentioned. As the component (B), a metal alkoxide is preferable.
In this invention, this hydrolysable metal containing compound may be used individually by 1 type, and 2 or more types may be mixed and used for it.
[0047]
In the present invention, a mixture comprising the organic polymer compound (A) and at least one hydrolyzable metal-containing compound (B) in a suitable polar solvent such as alcohol, ketone or ether. When an acid such as hydrochloric acid, sulfuric acid, nitric acid or the like, or a cation exchange resin as a solid acid, is usually hydrolyzed at a temperature of 0 to 100 ° C., preferably 20 to 60 ° C., and a solid acid is used, After removing it, if necessary, the solvent is distilled off or added, and the viscosity is adjusted to be suitable for coating to prepare a coating agent comprising a coating solution. If the temperature is too low, the hydrolysis does not proceed. If the temperature is too high, the hydrolysis / polymerization reaction proceeds too fast, making it difficult to control, and the gradient of the resulting gradient coating film may be reduced.
[0048]
Depending on the type of inorganic component, hydrolysis and polycondensation may gradually proceed even after the coating solution is prepared, and the coating conditions may vary. Therefore, a solid dehydrating agent that is insoluble in the coating solution, such as sulfuric anhydride. By adding magnesium or the like, it is possible to prevent the pot life from decreasing. In this case, the coating solution is used for coating after removing the dehydrating agent.
[0049]
Next, an average thickness after drying of the coating agent comprising the coating solution thus obtained is 40 to 100 nm directly on the plastic film surface or on the ultraviolet shielding layer provided on the substrate film surface. The coating film is formed by known means such as dip coating, spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating. A desired organic-inorganic composite gradient film is formed by forming and performing a known drying process, for example, a heat drying process at a temperature of about 40 to 150 ° C.
If the average thickness of the composite gradient film is less than 40 nm, the function as an intermediate film is not sufficiently exhibited, and it is difficult to obtain a durable photocatalytic film, and if it exceeds 100 nm, cracks or the like may occur due to film deflection or bending. There is.
[0050]
In the present invention, this organic-inorganic composite gradient film is substantially obtained in a bending test by 2R bending in which a film with a gradient film is wound 360 ° with the gradient film on the outside on a stainless steel rod having a diameter of 2 mm. It is necessary that cracks are not observed.
The organic-inorganic composite gradient film having such thickness and properties can be formed, for example, by applying the coating agent so that the amount in terms of component (A) is 0.5 to 3.0 g / 100 m2. it can.
[0051]
In the organic-inorganic composite gradient film thus formed, the surface layer has a metal component content in the composite film of almost 100%, and gradually decreases in the direction of the base material. Then, it becomes almost 0%. That is, in the organic-inorganic composite gradient film, the surface in contact with the plastic film is substantially composed of only the organic polymer compound component, and the other open surface is composed of only the metal oxide compound component. .
To confirm such a tilted structure, for example, the surface of the tilted film is sputtered and the film is shaved, and the content of carbon atoms and metal atoms on the film surface is measured over time by X-ray photoelectron spectroscopy. Can be done.
[0052]
Although there is no restriction | limiting in particular as content of the metal component in this composite gradient film, Usually in 5-98 weight% in conversion of a metal oxide, Preferably it is 20-98 weight%, Especially preferably, it is the range of 50-90 weight%. is there. The degree of polymerization and the molecular weight of the organic polymer compound are not particularly limited as long as they can be formed into a film, and may be appropriately selected according to the type of polymer compound and desired physical properties of the gradient film.
[0053]
In the photocatalyst film of the present invention, a photocatalytic active material layer is provided on the organic-inorganic composite gradient film formed in this way. There is no restriction | limiting in particular as a photocatalytic active material used for this photocatalytic active material layer, For example, a conventionally well-known thing, for example, titanium dioxide, strontium titanate (SrTiO)_Three), Barium titanate (BaTi)_FourO₉), Sodium titanate (Na₂Ti₆O₁₃), Zirconium dioxide, α-Fe₂O_Three, Tungsten oxide, K_FourNb₆O₁₇, Rb_FourNb₆O₁₇, K₂Rb₂Nb₆O₁₇, Cadmium sulfide, zinc sulfide and the like. These may be used alone or in combination of two or more. Among these, titanium dioxide, particularly anatase titanium dioxide, is useful as a practical photocatalytically active material. This titanium dioxide exhibits excellent photocatalytic activity by absorbing light of a specific wavelength in the ultraviolet region contained in daily light such as sunlight.
[0054]
For the purpose of promoting photocatalytic activity, the photocatalytically active material layer in the present invention may contain a conventionally known photocatalyst promoter, if desired, together with the photocatalytic active material. Preferred examples of the photocatalyst promoter include platinum group metals such as platinum, palladium, rhodium, and ruthenium. These may be used alone or in combination of two or more. The addition amount of this photocatalyst promoter is usually selected in the range of 1 to 20% by weight based on the total weight of the photocatalytically active material and the photocatalyst promoter from the viewpoint of photocatalytic activity.
[0055]
The method for forming the photocatalytic active material layer on the organic-inorganic composite gradient film is not particularly limited, and various methods can be used. For example, PVD methods (physical vapor deposition methods) such as vacuum deposition methods and sputtering methods can be used. ) Or a metal spraying method, or a wet method using a coating solution.
[0056]
As the dry method, a metal spraying method is particularly preferable because the apparatus and operation are simple. This metal spraying method is a method in which a photocatalytically active material is melted using a gas combustion flame, sprayed onto a composite gradient film to form a photocatalytically active material layer. In this method, when a photocatalyst accelerator is used together with the photocatalytic active material, a mixture of the photocatalytic active material and the photocatalyst accelerator may be melted and sprayed on the composite gradient film, or first, the photocatalytic active material. May be sprayed on the composite gradient film, and further the melt of the photocatalyst promoter may be sprayed thereon.
[0057]
On the other hand, in the method using the coating liquid, in a suitable solvent, prepare a coating liquid consisting of a dispersion containing fine particles such as a photocatalytically active material and a photocatalyst accelerator or an inorganic binder used as necessary, This coating solution is applied onto the composite gradient film by a known method such as dip coating, spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, gravure coating. For example, a method of forming a photocatalytically active material layer by natural drying or heat drying may be used. In the case of using a photocatalyst accelerator, for example, a coating liquid containing fine particles such as a photocatalytic active material and an inorganic binder that is used as desired is applied on the composite gradient film to form a coating film of the photocatalytic active material, A plastic film in which a coating film of a photocatalytic active material is formed on the composite gradient film is immersed in an aqueous solution containing metal ions of a photocatalyst promoter from which dissolved oxygen has been removed, and the metal ions are irradiated with light. A photocatalytically active material layer can also be formed by providing a photocatalyst promoter layer on a photocatalytically active material coating by a photodeposition method of depositing on the coating surface.
[0058]
The inorganic binder used as necessary in the preparation of the coating liquid is not particularly limited as long as it can exhibit the function as a binder, and is conventionally known, for example, silicon, aluminum, titanium, zirconium, Examples thereof include oxides and hydroxides of metals such as magnesium, niobium, tungsten, tin, and tantalum, or composite oxides and hydroxides of two or more metals selected from the above metals. This inorganic binder may be used alone or in combination of two or more. In addition, the coating liquid may contain other conventionally known additive components used in the coating liquid for forming the photocatalytic active material layer, such as a silicone resin, a modified silicone resin, and a silane coupling agent. .
[0059]
In the photocatalytic film of the present invention, the thickness of the photocatalytically active material layer is usually selected in the range of 10 nm to 5 μm. If the thickness is less than 10 nm, the photocatalytic function is not sufficiently exerted, and if it exceeds 5 μm, the effect of improving the photocatalytic function is not recognized for the thickness, but rather cracks occur or the flexibility is lowered. A preferred thickness is 30 nm to 3 μm, and a range of 40 nm to 1 μm is particularly preferable.
[0060]
In the photocatalytic film of the present invention, a photocatalytic active material layer is provided on a plastic film via an organic-inorganic composite gradient film, and the composite gradient film is substantially a metal at the interface with the photocatalytic active material layer. Since it is composed only of an oxide-based compound component and only an organic polymer compound component on the surface in contact with the plastic film, the adhesion between the base material and the composite gradient film and the photocatalytically active material layer and the composite gradient film Adhesion is very good. Moreover, since the composite gradient film is substantially only a metal oxide compound component at the interface with the photocatalytic active material layer, deterioration of the composite gradient film due to the photocatalytic function of the photocatalytic active material layer is suppressed.
[0061]
Furthermore, since the photocatalytic film of the present invention uses a plastic film as a base material, it has excellent resistance to active energy rays such as ultraviolet rays used for excitation of the photocatalytic active material layer, and is excellent in durability. ing. In addition, the thickness of the intermediate film of the conventional photocatalyst film is as thick as several μm, whereas the photocatalyst film of the present invention is flexible because the thickness of the composite gradient film as the intermediate film is as thin as 40 to 100 nm. Good and flexible.
Therefore, the photocatalytic film of the present invention has a total light transmittance and a haze value decrease of 5% or less in an accelerated weathering test for 900 hours using a carbon arc type sunshine weather meter, and the occurrence of interference is visually recognized. I can't.
[0062]
In the photocatalytic film of the present invention, a pressure-sensitive adhesive layer can be provided on the surface of the plastic film opposite to the photocatalytically active material layer, if necessary. Thereby, the photocatalytic film of the present invention can be easily attached to the adherend.
There is no restriction | limiting in particular as an adhesive which comprises the said adhesive layer, Although it can select and use suitably according to a condition from conventionally well-known various adhesives, it is acrylic especially from points, such as a weather resistance. System, urethane and silicone adhesives are preferred. The thickness of this pressure-sensitive adhesive layer is usually 5 to 100 μm, preferably 10 to 60 μm. This pressure-sensitive adhesive layer can contain a weathering agent such as the aforementioned ultraviolet absorber or light stabilizer, if necessary.
[0063]
Moreover, in the photocatalyst film of this invention, a peeling sheet can be provided on the said adhesive layer if desired. Examples of the release sheet include paper such as glassine paper, coated paper, and laminated paper, and various plastic films coated with a release agent such as silicone resin. Although there is no restriction | limiting in particular about the thickness of this peeling sheet, Usually, it is about 20-150 micrometers. When the release sheet is provided as described above, the release sheet may be peeled off when used, and attached so that the pressure-sensitive adhesive layer surface is in contact with the adherend.
[0064]
FIG. 1 is a cross-sectional view showing an example of the configuration of the photocatalytic film of the present invention. The photocatalytic film 10 is organic-inorganic on a plastic film 1 having an ultraviolet shielding layer 1b on the surface of a base film 1a. The photocatalytically active material layer 3 is provided via the composite gradient film 2, and the release sheet 5 is provided on the opposite surface of the plastic film 1 via the adhesive layer 4.
The ultraviolet blocking layer 1b is not necessarily required when the plastic film 1a has high durability. If necessary, the ultraviolet blocking layer 1b may be provided between the adhesive layer 4 and the plastic film 1a.
[0065]
Such a photocatalytic film of the present invention is transparent and has antifouling, antibacterial, deodorizing functions, and the like. For example, the body and window glass of automobiles and various transportation equipment, buildings and their window glass, road Affixed to the inside of signs, roadside signs, sound insulation boards such as expressways, curved mirrors, frozen / refrigerated showcases and greenhouses, etc. to prevent contamination of the objects to be attached, decomposition of trace harmful substances in the internal space, and Demonstrate the effect of scattering when the glass breaks.
Moreover, it can be used as a wrapping film for food packaging or as an inner surface sticking of a drinking water storage plastic container by utilizing an antibacterial function.
[0066]
【Example】
EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited at all by these examples.
[0067]
In addition, the weather resistance of the base material, the gradient and flexibility of the intermediate film, and the performance of the photocatalytic film were evaluated according to the following methods.
(1) Weather resistance of substrate
The film having a thickness of 50 μm was subjected to a 900-hour accelerated weathering test using a carbon arc type sunshine weather meter, and the rate of decrease in tensile strength according to JIS C2318 was measured.
Test conditions for carbon arc type sunshine weather meter (JIS K7350-4)
Model: Suga Test Instruments Co., Ltd. Sunshine Weather Meter (S300)
Light source: 225 W / m²
Cycle: Irradiation 102 minutes, irradiation + rainfall 18 minutes 2 hours 1 cycle
Black panel temperature: 63 ± 3 ℃
Relative humidity: 55 ± 5%
[0068]
(2) Gradient of the interlayer film
Using an XPS apparatus “PHI-5600” [manufactured by ULVAC-PHI Co., Ltd.], argon sputtering (4 kV) was applied at intervals of 3 minutes to scrape the film, and the content of carbon atoms and metal atoms on the film surface The gradient was measured by photoelectron spectroscopy.
(3) Flexibility of interlayer film
A 4 mm wide film with an intermediate film is wound around a stainless steel rod with a diameter of 2 mm, the intermediate film is wound 360 °, a 2R bending test is performed, and the bent portion of the intermediate film is measured for surface shape by Keyence Corporation Observation with a microscope “VF-7500” at a magnification of 2500 was conducted to examine the presence or absence of occurrence of linear cracks, peeling, and the like.
[0069]
(4) Accelerated weathering test of photocatalytic film
The photocatalyst film was subjected to (1) 900-hour accelerated weathering test using a carbon arc sunshine weathermeter under the same conditions as the weather resistance of the base material. The initial value of the total light transmittance and haze value, the value after the test, and water The contact angle was measured and the presence or absence of interference was examined by visual observation.
The total light transmittance and the haze value were measured with a Nippon Denshoku Industries Co., Ltd. turbidimeter “NDH2000” under conditions based on JIS K7361.
The water contact angle was measured using a contact angle measuring device “G-1-1000” manufactured by Elma Sales Co., Ltd. at a temperature of 25 ° C. and a humidity of 50%.
[0070]
Example 1
To a solution obtained by dissolving 120 g of titanium tetraisopropoxide in 100 g of ethanol, a mixed solution of 25 g of concentrated hydrochloric acid, 5 g of water and 50 g of ethanol was slowly added dropwise with stirring. This solution was stirred at room temperature for 2 hours to obtain an inorganic component liquid (a).
In a mixed solution of 10.9 g of methyl methacrylate and 1.36 g of γ-methacryloxypropyltrimethoxysilane, 0.1 g of 2,2′-azobisisobutyronitrile was dissolved and then stirred at 75 ° C. for 3 hours. It was made to react and the copolymer (A) whose weight average molecular weight of polystyrene conversion by a gel permeation chromatography (GPC) method is about 70,000 was obtained. 1.0 g of this copolymer was dissolved in 100 ml of methyl isobutyl ketone to obtain an organic component solution (b) having a concentration of 10 g / L.
[0071]
After adding 10 ml of organic component solution (b) and 40 ml of 2-ethoxyethanol to 40 ml of methyl isobutyl ketone, 10 ml of inorganic component liquid (a) was added with slow stirring to prepare a coating liquid (c).
The copolymer (A) is coated with the coating liquid (c) on a polyethylene terephthalate (PET) film (Tetron HB-3 manufactured by Teijin DuPont Films Co., Ltd., 50 μm thick) kneaded with a weathering agent by a bar coating method. Is 0.914g / 100m²Then, it was dried at 80 ° C. for 15 hours to obtain a PET film with an organic-inorganic composite gradient film as an intermediate film. The average thickness of the obtained film was 83 nm.
[0072]
In addition, the decreasing rate of the tensile strength by the accelerated weathering test of the used PET film was 45%. The XPS measurement result of the above gradient film is shown in FIG. From this figure, it was confirmed that the film has a gradient. Further, as a result of the 2R bending test of the inclined film, no abnormalities such as cracks and peeling were observed.
[0073]
Next, a 10-fold weight diluted solution of “Vistrator L / NSC-200C” manufactured by Nippon Soda Co., Ltd. was applied on this inclined film by spin coating, and then heat-treated at 80 ° C. for 1 hour to obtain a thickness of 50 nm. The photocatalytic active material layer (hereinafter abbreviated as photocatalytic layer) was formed, and a photocatalytic film composed of a photocatalyst layer / PET film with an organic-inorganic composite gradient film was produced.
[0074]
As a result of performing an accelerated weathering test on this photocatalyst film, the haze value was 1.7% with respect to the initial 0.4%, and the total light transmittance was almost changed to 87.6% with respect to the initial 86.2%. The water contact angle showing the photocatalytic function was less than 3 °, and no interference was observed. The results are shown in Table 1.
[0075]
Example 2
In the same manner as in Example 1, an inorganic component solution (a) and an organic component solution (b) were obtained.
After adding 6 ml of organic component solution (b) and 40 ml of 2-ethoxyethanol to 40 ml of methyl isobutyl ketone, 10 ml of inorganic component liquid (a) was added with slow stirring to prepare a coating liquid (d).
[0076]
The coating liquid (d) was added to a PET film (Tetron HB-3, manufactured by Teijin DuPont Films Co., Ltd., 50 μm thick) with a copolymer (A) of 0.548 g / 100 m by a bar coating method.²Then, it was dried at 80 ° C. for 15 hours to obtain a PET film with an organic-inorganic composite gradient film. The average thickness of the obtained film was 75 nm. The XPS measurement result of this inclined film is shown in FIG. From this figure, it was confirmed that the film has a gradient. Further, as a result of the 2R bending test of the inclined film, no abnormalities such as cracks and peeling were observed.
[0077]
Next, a photocatalyst film composed of a photocatalyst layer / PET film with an organic-inorganic composite gradient film was produced in the same manner as in Example 1.
As a result of the accelerated weathering test on this photocatalyst film, the haze value was 1.9% with respect to the initial 0.4%, and the total light transmittance was almost changed with 86.3% with respect to the initial 86.5%. The water contact angle was less than 3 °, and no interference was observed. The results are shown in Table 1.
[0078]
Example 3
In the same manner as in Example 1, an inorganic component solution (a) and an organic component solution (b) were obtained.
After adding 22.5 ml of the organic component solution (b) and 40 ml of 2-ethoxyethanol to 27.5 ml of methyl isobutyl ketone, 10 ml of the inorganic component solution (a) was slowly added with stirring to prepare a coating solution (e). .
[0079]
The coating liquid (e) was coated on a PET film (Tetron HB-3, manufactured by Teijin DuPont Films Co., Ltd., 50 μm thick) with a copolymer (A) of 2.057 g / 100 m by a bar coating method.²Then, it was dried at 80 ° C. for 15 hours to obtain a PET film with an organic-inorganic composite gradient film. The average thickness of the obtained film was 90 nm. FIG. 4 shows the XPS measurement result of the inclined film. From this figure, it was confirmed that the film has a gradient. Further, as a result of the 2R bending test of the inclined film, no abnormalities such as cracks and peeling were observed.
[0080]
Next, a photocatalyst film composed of a photocatalyst layer / PET film with an organic-inorganic composite gradient film was produced in the same manner as in Example 1.
As a result of the accelerated weathering test on this photocatalyst film, the haze value was 1.9% with respect to the initial 0.4%, and the total light transmittance was almost changed to 86.5% with respect to the initial 87.5%. The water contact angle was 6 °, and no interference was observed. The results are shown in Table 1.
[0081]
Example 4
In the same manner as in Example 1, an inorganic component solution (a) and an organic component solution (b) were obtained.
After adding 10 ml of the organic component solution (b) and 45.0 ml of 2-ethoxyethanol to 40 ml of methyl isobutyl ketone, 5.0 ml of the inorganic component solution (a) was slowly added with stirring to prepare a coating solution (f). .
[0082]
The coating liquid (f) was applied to a PET film (Tetron HB-3 manufactured by Teijin DuPont Films Co., Ltd., 50 μm thick) with a copolymer (A) of 0.914 g / 100 m by a bar coating method.²Then, it was dried at 80 ° C. for 15 hours to obtain a PET film with an organic-inorganic composite gradient film. The average thickness of the obtained film was 45 nm. The XPS measurement result of this inclined film is shown in FIG. From this figure, it was confirmed that the film has a gradient. Further, as a result of the 2R bending test of the inclined film, no abnormalities such as cracks and peeling were observed.
[0083]
Next, a photocatalyst film composed of a photocatalyst layer / PET film with an organic-inorganic composite gradient film was produced in the same manner as in Example 1.
As a result of the accelerated weathering test on this photocatalyst film, the haze value was 1.5% with respect to the initial 0.4%, and the total light transmittance was almost 87.5% with respect to the initial 90.2%. The water contact angle was 8 °, and no interference was observed. The results are shown in Table 1.
[0084]
Example 5
In the same manner as in Example 1, an inorganic component solution (a) and an organic component solution (b) were obtained.
After adding 10 ml of the organic component solution (b) and 37.5 ml of 2-ethoxyethanol to 40 ml of methyl isobutyl ketone, 12.5 ml of the inorganic component liquid (a) was added with slow stirring to prepare a coating solution (g). .
[0085]
The coating liquid (g) was coated on a PET film (Tetron HB-3 manufactured by Teijin DuPont Films Co., Ltd., 50 μm thick) with a copolymer (A) of 0.914 g / 100 m by a bar coating method.²Then, it was dried at 80 ° C. for 15 hours to obtain a PET film with an organic-inorganic composite gradient film. The average thickness of the obtained film was 95 nm. The XPS measurement result of this inclined film is shown in FIG. From this figure, it was confirmed that the film has a gradient. Further, as a result of the 2R bending test of the inclined film, no abnormalities such as cracks and peeling were observed.
[0086]
Next, a photocatalyst film composed of a photocatalyst layer / PET film with an organic-inorganic composite gradient film was produced in the same manner as in Example 1.
As a result of an accelerated weathering test on this photocatalyst film, the haze value was 1.7% with respect to the initial 0.6%, and the total light transmittance was almost changed to 84.2% with respect to the initial 85.7%. The water contact angle was less than 3 °, and no interference was observed. The results are shown in Table 1.
[0087]
Example 6
In the same manner as in Example 1, the inorganic component liquid (a) and the organic component solution (b) were mixed and stirred to prepare a coating liquid (c).
Also, on a single side of a PET film “Lumirror T-60” manufactured by Toray Industries Inc. having a thickness of 50 μm, 100 g equivalent of an ultraviolet absorbing primer (“Udable UV-G300” manufactured by Nippon Shokubai Co., Ltd.) and “Sumidule N-” manufactured by Sumitomo Bayer Urethane Co., Ltd. 3200 "13 g equivalent was mixed, and a film was formed with a thickness of 4 μm.The coating liquid (c) was coated on the weather-resistant primer layer in the same manner as in Example 1 with the copolymer (A) being 0.914 g / 100 m.²Then, it was dried at 80 ° C. for 15 hours to obtain a PET film with an organic-inorganic composite gradient film. The average thickness of the obtained film was 84 nm.
[0088]
In addition, the decreasing rate of the tensile strength by the accelerated weathering test of the used weatherable primer-coated PET film was 5%. The XPS measurement result of the above gradient film is shown in FIG. From this figure, it was confirmed that the film has a gradient. Further, as a result of the 2R bending test of the inclined film, no abnormalities such as cracks and peeling were observed.
[0089]
Next, a photocatalyst film composed of a photocatalyst layer / PET film with an organic-inorganic composite gradient film was produced in the same manner as in Example 1.
As a result of the accelerated weathering test on this photocatalyst film, the haze value was 2.2% with respect to the initial 1.9%, and the total light transmittance was almost changed to 86.8% with respect to the initial 86.5%. The water contact angle was 6 °, and no interference was observed. The results are shown in Table 1.
[0090]
Example 7
To a solution obtained by dissolving 120 g of tetraethoxysilane in 100 g of ethanol, 0.7 ml of a 1 mol / liter nitric acid aqueous solution, a mixed solution of 80 g of water and 50 g of ethanol was slowly added dropwise with stirring. This solution was stirred at 30 ° C. for 72 hours to obtain an inorganic component liquid. On the other hand, an organic component solution (b) was obtained in the same manner as in Example 1.
After adding 10 ml of organic component solution (b) and 40 ml of 1-butanol to 40 ml of methyl isobutyl ketone, 10 ml of the inorganic component solution was added with slow stirring to prepare a coating solution (h).
[0091]
In the same manner as in Example 1, the organic component was 0.914 g / 100 m on the same substrate (weather-resistant primer-coated PET film) used in Example 6 for this coating liquid (h).²Then, it was dried at 80 ° C. for 15 hours to obtain a PET film with an organic-inorganic composite gradient film. The average thickness of the obtained film was 80 nm.
The XPS measurement result of this inclined film is shown in FIG. From this figure, it was confirmed that the film has a gradient. Further, as a result of the 2R bending test of the inclined film, no abnormalities such as cracks and peeling were observed.
[0092]
Next, the photocatalyst film which consists of a PET film with a photocatalyst layer / organic-inorganic composite inclination film was produced like Example 1.
As a result of an accelerated weathering test on this photocatalyst film, the haze value was 2.1% with respect to the initial 1.7%, and the total light transmittance was almost changed to 90.2% with respect to the initial 90.5%. The water contact angle was 6 °, and no interference was observed. The results are shown in Table 1.
[0093]
Example 8
In the same manner as in Example 1, the inorganic component solution (a) and the organic component solution (b) were mixed and stirred to prepare a coating solution (c).
In addition, an acrylic film “Sanduren SD009NAT” manufactured by Kaneka Chemical Industry Co., Ltd. has a 50 μm thickness on one side and 100 g equivalent of an ultraviolet absorbing primer (“Udouble UV-G300” manufactured by Nippon Shokubai Co., Ltd.) and “Sumidule N” manufactured by Sumitomo Bayer. −3200 ”(13 g equivalent) was mixed to form a film with a thickness of 1 μm. The coating liquid (c) was applied to the primer layer obtained in the same manner as in Example 1 except that the copolymer (A) was 0.914 g / 100 m.²And then dried at 60 ° C. for 15 hours to obtain an acrylic film with an organic-inorganic composite gradient film. The average thickness of the obtained film was 75 nm.
[0094]
In addition, the decreasing rate of the tensile strength by the accelerated weathering test of the primer coat | covered acrylic film used was 4%. The XPS measurement result of the above gradient film is shown in FIG.
From this figure, it was confirmed that the film has a gradient. Further, as a result of the 2R bending test of the inclined film, no abnormalities such as cracks and peeling were observed.
[0095]
Next, the photocatalyst film which consists of an acrylic film with a photocatalyst layer / organic-inorganic composite gradient film was produced like Example 1. FIG.
As a result of performing an accelerated weathering test (900 hours) on this photocatalyst film, the haze value was 1.3% with respect to the initial 0.9%, and the total light transmittance was 91.1% with respect to the initial 91.5%. No change was observed, the water contact angle was less than 3 °, and no interference was observed. The results are shown in Table 1.
[0096]
Example 9
In the same manner as in Example 1, the inorganic component solution (a) and the organic component solution (b) were mixed and stirred to prepare a coating solution (c).
In addition, 100 g equivalent of an ultraviolet absorbing primer (“Udouble UV-G300” manufactured by Nippon Shokubai Co., Ltd.) and an isocyanate-based curing agent “Sumijoule” manufactured by Sumitomo Bayer on one side of a 100 μm thick polycarbonate film “Iupilon Film FE2000” manufactured by Mitsubishi Engineering Plastics N-3200 ”13 g equivalent was mixed, and a film was formed to a thickness of 4 μm. The coating liquid (c) was applied to the primer layer obtained in the same manner as in Example 1 except that the copolymer (A) was 0.914 g / 100 m.²Then, it was dried at 80 ° C. for 15 hours to obtain a polycarbonate film with an organic-inorganic composite gradient film. The average thickness of the obtained film was 78 nm.
[0097]
In addition, the decreasing rate of the tensile strength by the accelerated weathering test of the primer coating polycarbonate film used was 9%. The XPS measurement result of the above gradient film is shown in FIG.
From this figure, it was confirmed that the film has a gradient. Further, as a result of the 2R bending test of the inclined film, no abnormalities such as cracks and peeling were observed.
[0098]
Next, a photocatalyst film composed of a polycarbonate film with a photocatalyst layer / organic-inorganic composite gradient film was produced in the same manner as in Example 1.
As a result of performing an accelerated weathering test (900 hours) on this photocatalyst film, the haze value was 2.5% relative to the initial 1.3%, and the total light transmittance was 90.2% relative to the initial 90.5%. No change was observed, the water contact angle was less than 3 °, and no interference was observed. The results are shown in Table 1.
[0099]
Comparative Example 1
Using a commercially available acrylic silicone-based coating liquid, an interlayer film having a thickness of 4 μm was formed on the PET film by the same operation as in Example 1 to obtain a PET film with an interlayer film. As a result of the 2R bending test of this intermediate film, no abnormality such as cracking or peeling was observed.
[0100]
Next, a photocatalyst film composed of a photocatalyst layer / a PET film with an intermediate film was produced in the same manner as in Example 1.
As a result of the accelerated weathering test on this photocatalyst film, the haze value was 5.5% with respect to the initial 2.7%, and the total light transmittance was 81.3% with respect to the initial 88.6%. A decrease in lightness was observed. Further, although the water contact angle was 8 °, occurrence of interference was observed. The results are shown in Table 1.
[0101]
Comparative Example 2
In the same manner as in Example 1, an inorganic component solution (a) and an organic component solution (b) were obtained.
After adding 4.4 ml of organic component solution (b) and 45.6 ml of 2-ethoxyethanol to 45 ml of methyl isobutyl ketone, 10 ml of inorganic component solution (a) was slowly added with stirring to prepare coating solution (i). .
[0102]
In this coating liquid (i), the organic component (A) was 0.40 g / 100 m as in Example 1.²Then, it was dried at 80 ° C. for 15 hours to obtain a PET film with an organic-inorganic composite gradient film. The average thickness of the obtained gradient film was 70 nm. As a result of the 2R bending test of the inclined film, cracks and peeling were observed. The results are shown in Table 1.
[0103]
Comparative Example 3
In the same manner as in Example 1, an inorganic component solution (a) and an organic component solution (b) were obtained.
After adding 35 ml of organic component solution (b) and 43 ml of 2-ethoxyethanol to 15 ml of methyl isobutyl ketone, 7 ml of inorganic component liquid (a) was added with slow stirring to prepare a coating solution (j).
[0104]
In the same manner as in Example 1, the coating liquid (j) had an organic component (A) of 3.2 g / 100 m.²And then dried at 80 ° C. for 15 hours to obtain a PET film with an organic-inorganic composite gradient film having a theoretical thickness of 80 nm. The coating film after drying was cloudy, and when the surface was observed with a microscope, many irregularities were observed. The results are shown in Table 1.
[0105]
Comparative Example 4
In the same manner as in Example 1, an inorganic component solution (a) and an organic component solution (b) were obtained.
After adding 10 ml of an organic component solution (b) and 48 ml of 2-ethoxyethanol to 40 ml of methyl isobutyl ketone, 2 ml of an inorganic component liquid (a) was slowly added with stirring to prepare a coating liquid (k).
[0106]
In this coating liquid (k), the organic component (A) was 0.914 g / 100 m as in Example 1.²Then, it was dried at 80 ° C. for 15 hours to obtain a PET film with an organic-inorganic composite gradient film. The average thickness of the obtained gradient film was 35 nm. As a result of the 2R bending test of the inclined film, abnormalities such as cracks and peeling were not observed.
[0107]
Next, a photocatalyst film composed of a PET film with a photocatalyst layer / organic-inorganic composite gradient film was produced in the same manner as in Example 1.
As a result of performing an accelerated weathering test on this photocatalyst film, the haze value was 10.5% with respect to the initial 2.7%, and the total light transmittance was 78.3% with respect to the initial 88.6%. A decrease was observed, and the occurrence of interference and a phenomenon that the water contact angle became 70 ° were observed. The results are shown in Table 1.
[0108]
Comparative Example 5
In the same manner as in Example 1, an inorganic component solution (a) and an organic component solution (b) were obtained.
After adding 10 ml of organic component solution (b) and 35 ml of 2-ethoxyethanol to 40 ml of methyl isobutyl ketone, 15 ml of inorganic component liquid (a) was added with slow stirring to prepare a coating solution (m).
[0109]
In this coating liquid (m), the organic component (A) was 0.914 g / 100 m as in Example 1.²Then, it was dried at 80 ° C. for 15 hours to obtain a PET film with an organic-inorganic composite gradient film. The average thickness of the obtained gradient film was 105 nm. As a result of the 2R bending test of the inclined film, generation of cracks was observed. The results are shown in Table 1.
[0110]
[Table 1]

[0111]
【The invention's effect】
The photocatalytic film of the present invention has a photocatalytically active material layer provided on a plastic film via an organic-inorganic composite gradient film, and has excellent interlayer adhesion, weather resistance, flexibility, etc. While the photocatalytic film has a durability of about 1 to 3 years, it has a durability of 3 years or more.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of the configuration of a photocatalytic film of the present invention.
2 is a graph showing the relationship between the sputtering time and the content of carbon atoms and titanium atoms in the organic-inorganic composite gradient film formed in Example 1. FIG.
3 is a graph showing the relationship between the sputtering time and the carbon atom content and the titanium atom content rate in the organic-inorganic composite gradient film formed in Example 2. FIG.
4 is a graph showing the relationship between the sputtering time and the carbon atom content and the titanium atom content in the organic-inorganic composite gradient film formed in Example 3. FIG.
5 is a graph showing the relationship between the sputtering time and the carbon atom content and the titanium atom content in the organic-inorganic composite gradient film formed in Example 4. FIG.
6 is a graph showing the relationship between the sputtering time and the carbon atom content and the titanium atom content rate in the organic-inorganic composite gradient film formed in Example 5. FIG.
7 is a graph showing the relationship between the sputtering time and the carbon atom content and the titanium atom content in the organic-inorganic composite gradient film formed in Example 6. FIG.
8 is a graph showing the relationship between the sputtering time and the carbon atom and silicon atom contents in the organic-inorganic composite gradient film formed in Example 7. FIG.
9 is a graph showing the relationship between the sputtering time and the carbon atom and silicon atom contents in the organic-inorganic composite gradient film formed in Example 8. FIG.
10 is a graph showing the relationship between the sputtering time and the carbon atom and silicon atom contents in the organic-inorganic composite gradient film formed in Example 9. FIG.
[Explanation of symbols]
1 Plastic film
1a Base film
1b UV shielding layer
2 Organic-inorganic composite gradient film
3 Photocatalytically active material layer
4 Adhesive layer
5 Release sheet
10 Photocatalytic film

Claims (5)

A photocatalytic film having a photocatalytically active material layer on one side of a plastic film via an organic-inorganic composite gradient film,
The plastic film is a film kneaded with a weathering agent or a film having an ultraviolet shielding layer on the surface of the organic-inorganic composite gradient film side,
The organic-inorganic composite gradient film is (A) a metal capable of forming a metal oxide by hydrolysis together with (A) an organic polymer compound having a metal-containing group capable of binding to the metal oxide by hydrolysis. It is formed by applying a coating agent obtained by hydrolyzing the containing compound so as to be 0.5 to 3.0 g / 100 m ² in terms of component (A) ,
Before SL organic - inorganic composite graded film has an average thickness 40 to 100 nm, and the bending test with 2R bending winding 360 ° in a stainless steel rod of diameter 2 mm, in which the generation of substantially no crack is observed A photocatalytic film characterized by being. 2. The photocatalytic film according to claim 1, wherein the plastic film has a tensile strength reduction rate of 50% or less according to JIS C2318 in a 900-hour accelerated weathering test using a carbon arc sunshine weather meter for a film having a thickness of 50 μm . The organic-inorganic composite gradient film includes a complex in which an organic polymer compound and a metal oxide compound are chemically bonded, and the component gradient in which the content of the metal component continuously changes in the thickness direction of the film 2. The structure having a structure, substantially consisting only of a metal oxide compound component at the interface with the photocatalytically active material layer, and consisting only of an organic polymer compound component on the surface in contact with the plastic film. Or the photocatalyst film of 2 . (A) The organic polymer compound of the component is (a) an ethylenically unsaturated monomer having a metal-containing group capable of binding to a metal oxide by hydrolysis in the molecule, and (b) an ethylenic compound not containing a metal. The photocatalyst film according to any one of claims 1 to 3, which is obtained by copolymerizing an unsaturated monomer. The metal-containing compound of component (B) is represented by the general formula (I)

(In the formula, R ¹ is a non-hydrolyzable group, R ² is a hydrolyzable group, M ¹ is a metal atom, m is a valence of the metal atom M ¹ , and n is a relationship of 0 <n ≦ m. An integer that satisfies
The photocatalytic film according to claim 1, wherein the photocatalytic film is a compound represented by the formula:

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