JP2004203632A - Sol-gel film having convex, concave or irregular surface shape, its manufacturing method and coating liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sol-gel film which has a high strength, has a convex, concave, or irregular surface shape controllable as desired, and can be applied to various functional films. <P>SOLUTION: The sol-gel film is made of a composition comprising a silica and a dimethyl silicone derivative and has the convex, concave, or irregular surface. The dimethyl silicone derivative has an average degree of polymerization of 5-2,000. A coating liquid for forming the sol-gel film is provided which comprises a solvent, a silica sol, and an alkoxyl-terminated dimethyl silicone derivative having an average degree of polymerization of 5-2,000. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００１０】
ここで、ｐ及びｑは２乃至３の整数、ｎは５乃至２０００の整数、Ａ¹、Ａ²は、それぞれ、２価のアルキレン基、又は酸素を示し、末端の酸素の少なくとも一つは珪素と結合していることを示している。
【００１１】
又、シリカとジメチルシリコーン誘導体との組成比が、重量比で１：０．０００１〜１：１０であることが好ましい。ゾルゲル膜を上記構造とすることで凸層及び／又は凹層を有するゾルゲル膜を、高温焼成を必要とせずに高耐久とすることができる。
【００１２】
前記ゾルゲル膜を得るための塗布液は、溶媒、シリカゾル、一般式［２］で表される平均重合度が５以上２０００以下のアルコキシ基末端ジメチルシリコーン誘導体とからなることを特徴とする。
【００１３】
【化４】

【００１４】
ここで、Ｒは１価のアルキル基、ｐ及びｑは２乃至３の整数、ｎは５乃至２０００の整数、Ａ¹、Ａ²は、それぞれ、２価のアルキレン基、又は酸素を示す。
【００１５】
又、溶媒が少なくとも水を有すること好ましく、塗布液中の水量が０．０１重量％以上１０重量％以下であることが好ましい。該塗布液は、アルコキシシランを加水分解及び重縮合して得られたシリカゾルにアルコキシ基末端ジメチルシリコーン誘導体を混合して得られたものであることが好ましい。
【００１６】
前記アルコキシ基末端ジメチルシリコーン誘導体の重合度の範囲を上記範囲内で選択、塗布液中の水分量を調整することで、ゾルゲル膜の表面形状を所望の形状や間隔に制御することができる。
【００１７】
本発明のゾルゲル膜の製法は、上記塗布液を基材に塗布し、溶媒を揮散させることで膜を形成することを特徴とする。又、ゾルゲル膜の表面の凸層及び／又は凹層を所望の形状や間隔に制御するためには、塗布液を基材に塗布するときの湿度を調整することが好ましい。
【００１８】
【発明の実施の形態】
本発明のゾルゲル膜は、シリカ及びジメチルシリコーンの組成物からなるゾルゲル膜で、前記膜が凸状又は凹状若しくは凹凸状の表面形状を有し、前記ジメチルシリコーンが一般式［１］で表される平均重合度が５以上２０００以下のジメチルシリコーン誘導体であることを特徴とするゾルゲル膜である。
【００１９】
【化５】

【００２０】
ここで、ｐ及びｑは２乃至３の整数、ｎは５乃至２０００の整数、Ａ¹、Ａ²は、それぞれ、２価のアルキレン基、又は酸素を示し、末端の酸素の少なくとも一つは珪素と結合していることを示している。
【００２１】
凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜をシリカ及びジメチルシリコーン誘導体との組成物としたのは、従来の凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜では、前記表面形状によって、ミストやオイル等の汚染物に付着しやすく、付着物に由来して耐擦傷性や耐磨耗性が低下する問題等に鑑みたからである。ジメチルシリコーン誘導体の潤滑性によって、膜表面の滑り性が良くなり、その結果、膜表面の滑り性が向上し、汚染物が付着しにくくなり、膜の耐久性が向上する。又、膜表面の滑り性は、ゾルゲル膜を基材上に形成する際に、基材上に塗布した塗布液の溶媒を揮散させるだけでも発現するので、従来の凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜を高耐久化するための４００℃以上の高温焼成を必要とせず、室温乾燥又は４００℃未満の低温焼成で高耐久の凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜を得ることができるので、低コスト化や基材の選択幅が広がる等の効果を発揮する。
【００２２】
一般式［１］で表されるジメチルシリコーン誘導体のｐ及びｑを２乃至３の整数としたのは、シリカとジメチルシリコーン誘導体とを強固に結合させ、高強度な膜とするためである。ここで、末端の酸素の少なくとも一つは珪素と結合していることを示している。ｎを５乃至２０００の整数としたのは、５未満では、ジメチルシリコーン誘導体による膜表面の滑り性改善に効果が少なく、２０００を超えると均質な膜を得にくいからである。
【００２３】
シリカとジメチルシリコーン誘導体のとの組成比は、重量比で１：０．０００１〜１：１０であることが好ましい。ジメチルシリコーン誘導体が前記組成比よりも少ない組成領域では、膜表面の滑り性改善の効果が少なく、前記組成比よりも多い組成領域では、均質な膜を得にくくなる。
【００２４】
本発明の凸状の表面形状とは、膜表面に突出部が０．３μｍ〜９０μｍ、好ましくは１μｍ〜３０μｍの周期で形成されたものである。前記突出部の最表層面の大きさは、突出部が多角形状の場合であっては最大の対角線、円弧状の場合であっては最大の径が、前記周期の０．１倍〜１倍であることが好ましい。前記突出部の高さは、２〜１００ｎｍであることが好ましい。
【００２５】
又、凹状の表面形状とは、膜表面にくぼみ部が０．３μｍ〜９０μｍ、好ましくは１μｍ〜３０μｍの周期で形成されたものである。前記くぼみ部の底部の大きさは、くぼみ部が多角形状の場合であっては最大の対角線、円弧状の場合であっては最大の径が、前記周期の０．１倍〜１倍であることが好ましい。くぼみ部の深さは、２ｎｍ〜膜厚とすることが好ましい。
【００２６】
さらに、凹凸状の表面形状とは、前記凸状の表面形状及び前記凹状の表面形状を両方有するものである。
【００２７】
シリカとジメチルシリコーン誘導体との組成物からなる凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜は、膜厚によっても、凸状の突出部の高さ、凹状のくぼみ深さを制御することができ、膜厚が大きい程、前記突出高さ、くぼみ深さが大きくなる。前記膜厚は、１０ｎｍ以上５００ｎｍ以下とすることが好ましい。膜厚が１０ｎｍ未満になると、基材上に均一な塗膜を形成することが困難となり、５００ｎｍを超えると、膜強度が弱くなるばかりか、クラックが生じやすくなり好ましくない。
【００２８】
本発明のゾルゲル膜は、シリカ、ジメチルシリコーン誘導体以外の他の成分が含有されていても良い。これらの成分としては、有機高分子、無機微粒子、界面活性剤、シランカップリング剤等が挙げられるが、これらに限定されるものではない。
【００２９】
又、本発明は、前記ゾルゲル膜を形成するための塗布液であり、前記塗布液は、溶媒、シリカゾル、一般式［２］で表される平均重合度が５以上２０００以下のアルコキシ基末端ジメチルシリコーン誘導体とからなる。シリカゾルは膜形成後にシリカとなり、一般式［２］で表されるアルコキシ基末端ジメチルシリコーン誘導体は、膜形成後には一般式［１］で表されるアルコキシ基末端ジメチルシリコーン誘導体となる。
【００３０】
【化６】

【００３１】
ここで、Ｒは１価のアルキル基、ｐ及びｑは２乃至３の整数、ｎは５乃至２０００の整数、Ａ¹、Ａ²は、それぞれ、２価のアルキレン基、又は酸素を示す。
【００３２】
一般式［２］で表されるアルコキシ基末端ジメチルシリコーン誘導体のｐ及びｑを２乃至３の整数としたのは、シリカゾルとジメチルシリコーン誘導体との架橋結合を容易にさせるためであり、結果得られる膜は高強度な膜となる。又、ｐ及びｑが０乃至１の整数であった場合、前記架橋結合が不十分なばかりか、シリカゾルとジメチルシリコーン誘導体との分相しすぎて、形成される膜はシリカとジメチルシリコーンの２層状の膜となり、凸状又は凹状若しくは凹凸状の表面形状は得られなくなる。ｎを５乃至２０００の整数としたのは、５未満では、ジメチルシリコーン誘導体による膜表面の滑り性改善に効果が少なく、２０００を超えると均質な塗布液を得にくいからである。
【００３３】
アルコキシ基末端ジメチルシリコーン誘導体の平均重合度は、ゾルゲル膜の凸状又は凹状若しくは凹凸状の周期に影響し、平均重合が大きい程得られる膜の凸状又は凹状若しくは凹凸状の周期は大きくなり、数十μｍの周期をも得ることができ、前記平均重合度を選択すれば、凸状又は凹状若しくは凹凸状の周期を適宜選択することができる。具体的には、平均重合度が１００以下と分子量が小さい場合には、０．３μｍ〜９μｍの周期をもつ凸状又は凹状若しくは凹凸状となりやすい。一方、平均重合度が１００超の比較的大きい分子量を用いた場合には、表面形状は１０μｍ〜９０μｍの周期をもつ凸状又は凹状若しくは凹凸状となりやすい。
【００３４】
ただし、塗布液の水分量、溶媒組成や塗布液を基材に塗布するときの湿度も凸及び／又は凹の周期や形状に影響するので、平均重合度と及び／又は凹の周期や形状との関係は上記に限るものではない。
【００３５】
前記のような表面形状の発現は、シリカゾル成分とアルコキシ基末端ジメチルシリコーン誘導体との相分離現象によるものである。ジメチルシリコーン誘導体の平均重合度を変化させて、表面形状が変化したのは、平均重合度が上記相分離現象に深く影響を与えるためである。
【００３６】
前記溶媒は、少なくとも水を有すること好ましく、塗布液中の水量が０．０１重量％以上１０重量％以下であることが好ましい。塗布液中の水分量が０．０１重量％未満だと、基材との濡れ性が低下し、基材上に均一に膜を形成することができなくなるので好ましくない。また１０重量％を超えると、アルコキシキ末端ジメチルシリコーン誘導体の溶解度が減少し、均質な塗布液が得られなくなるので好ましくない。前記水量範囲において、適切な水量を選択すると、凸状の表面形状を有するゾルゲル膜、凹状の表面形状を有するゾルゲル膜を適宜得ることができる。塗布液の水量が少ないと、得られる膜の表面形状は凹状となり、水量が多いと凸状となる。
【００３７】
他の溶媒成分としては、エチルアルコール、イソプロピルアルコールなどの低級アルコール、塩酸、硝酸、硫酸、酢酸等の酸性溶液、水酸化ナトリウム、アンモニア等の塩基溶液、又は、それらの混合溶媒が望ましいが、アルコール類に限らず、アセトン、メチルエチルケトン、イソホロン等のケトン類、酢酸エチル、酢酸ブチル等のエステル類、トルエン、ベンゼン、キシレン等の芳香族系炭化水素溶媒類、ジエチルエーテル、ジイソプロピルエーテル等のエーテル類、クロロホルム、四塩化炭素等の塩素系溶媒やそれらの混合物を用いることができる。
【００３８】
前記塗布液は、アルコキシシランを加水分解及び重縮合して得られたシリカゾルにアルコキシ基末端ジメチルシリコーン誘導体を混合して得られたものであることが好ましい。アルコキシシランとしては、テトラメトキシシラン、テトラエトキシシラン、テトラプロポキシシラン、テトラブトキシシラン等のテトラアルコキシシラン類、メチルトリエトキシシラン、メチルトリメトキシシラン、エチルトリメトキシシラン、エチルトリエトキシシラン、プロピルトリメトキシシラン、プロピルトリエトキシシラン等のトリアルコキシシラン類、又はジアルコキシシラン類等を使用することができる。尚上記アルコキシシランの中でもテトラメトキシシラン、テトラエトキシシラン、メチルトリエトキシシラン、メチルトリメトキシシラン、エチルトリメトキシシラン、エチルトリエトキシシラン等が特に好ましい。
【００３９】
前記シリカゾルの調製は、例えば、アルコキシシラン（例えば、テトラエトキシシラン）と溶媒を所定量混合、攪拌（例えば、約３０分程度）し溶液Ａを得る。溶媒としては、水、エチルアルコール、イソプロピルアルコールなどの低級アルコール、塩酸、硝酸、硫酸、酢酸等の酸性溶液、水酸化ナトリウム、アンモニア等の塩基溶液、又は、それらの混合溶媒が望ましいが、アルコール類に限らず、アセトン、メチルエチルケトン、イソホロン等のケトン類、酢酸エチル、酢酸ブチル等のエステル類、トルエン、ベンゼン、キシレン等の芳香族系炭化水素溶媒類、ジエチルエーテル、ジイソプロピルエーテル等のエーテル類、クロロホルム、四塩化炭素等の塩素系溶媒やそれらの混合物等も用いることができる。一方、酸性水溶液と前記溶媒を混合、攪拌して溶液Ｂを得る。次いで、溶液Ａと溶液Ｂを混合後、室温で攪拌してアルコキシシランの加水分解及び重縮合反応を進めシリカゾルを得る。攪拌時間は、１０分から６ケ月が好ましく、特に３０分から１ヶ月が好ましいが、室温以外で攪拌する場合はこれに限定されるわけではない。以上のようにアルコキシシランの加水分解は、アルコキシシランに少量の水と塩酸、硝酸、酢酸などの酸触媒を添加し行うことができ、その加水分解物を室温又は加熱しながら攪拌することにより重縮合させ、シリカゾルを得ることができる。尚、シリカゾルの調製法としては、上記の方法に限定されるものではないが、上記のようなアルコキシシランを溶媒で希釈したものと、溶媒で希釈した酸性水溶液を徐々に混合する方法は、急激な反応を避けることができ、より均質な反応が得られるので、好ましい。
【００４０】
前記塗布液を基材上に塗布し、溶媒を揮散させることで高耐久の凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜を得ることができるが、前記溶媒の揮散を促進させるために焼成を行うことができる。４００℃〜８００℃で焼成を行うこともできるが、経済的な観点から、１００℃〜４００℃、より好ましくは、１５０℃〜３００℃で焼成することが好ましい。
【００４１】
基材上に前記塗布液を塗布する手段は、ノズルフロ−コ−ト法、ディッピング法、スプレー法、リバ−スコ−ト法、フレキソ法、印刷法、フローコート法、スピンコート法、及びそれらの併用等既知の被覆手段など各種被覆法が適宜採用することができる。
【００４２】
前記塗布液を基材に塗布するときの湿度は、形成されるゾルゲル膜の凸状又は凹状若しくは凹凸状の周期に影響するので、塗布液を基材に塗布する際は、湿度を調整することが好ましい。前記ゾルゲル膜を得るために、湿度を３０％乃至７０％の範囲で調湿することができ、湿度が高いほど、凸状又は凹状若しくは凹凸状の周期は大きくなる。
【００４３】
前記基材としては、代表的なものとしてはガラスがあげられる。そのガラスは自動車用、建築用、産業用ガラス等に通常用いられている板ガラスであり、フロート法、デュープレックス法、ロールアウト法等による板ガラスであって、製法は特に問わない。
【００４４】
ガラス種としては、クリアをはじめグリーン、ブロンズ等の各種着色ガラスやＵＶ、ＩＲカットガラス、電磁遮蔽ガラス等の各種機能性ガラス、網入りガラス、低膨張ガラス、ゼロ膨張ガラス等防火ガラスに供し得るガラス、強化ガラスやそれに類するガラス、合わせガラスのほか複層ガラス等、銀引き法、あるいは真空成膜法により作製された鏡、さらには平板、曲げ板等各種ガラス製品を使用できる。板厚としては１．０ｍｍ以上１０ｍｍ以下が好ましく、自動車用としては１．０ｍｍ以上５．０ｍｍ以下が好ましい。基材への前記ゾルゲル膜の形成は、基材の片面だけであってもよいし、両面に行ってもよい。又、前記ゾルゲル膜の形成は基材面の全面でも一部分であってもよい。
【００４５】
加えて、基材は、ガラスに限定されるものではなく、光透過性や光反射性を有するポリエチレンテレフタレート等の樹脂フィルム、ポリカーボネート等の樹脂、金属、セラミックス等も、前記溶媒揮散時に変形しないものであれば使用することができる。
【００４６】
本発明のゾルゲル膜を下地膜としてその上にフルオロアルキルシラン等からなる機能性膜を形成し積層膜とした場合、該積層膜はゾルゲル膜の滑り性を保持し、滑り性由来の耐久性を発揮する等に奏効する。
【００４７】
【実施例】
以下に本発明の実施例について説明する。
【００４８】
〔シリカゾルの調製〕
シリカゾルは、テトラエトキシシラン〔Ｓｉ(ＯＣ₂Ｈ₅)₄：ＴＥＯＳ〕の加水分解および重縮合反応を進めることにより調製した。図１にシリカゾルの調製手順と各成分の混合割合（重量比）を示す。先ず、ＴＥＯＳ；３１２.５ｇとエキネンＦ１（９０重量％のエタノールと１０重量％のイソプロピルアルコールからなる低級アルコールの混合物）；４５０.０ｇを混合し、約３０分間攪拌した（溶液Ａ）。また、６０％硝酸水溶液；７.５ｇ、Ｈ₂Ｏ；２１０.０ｇおよびエキネンＦ１；２０.０ｇを混合し、約３０分間攪拌した（溶液Ｂ）。次いで、溶液Ａと溶液Ｂを混合後、約１５時間室温で攪拌することによってシリカゾルＸを得た。
【００４９】
〔塗布液の調製〕
塗布液は、ジメチルシリコーン誘導体と上記〔シリカゾルの調製〕で得たシリカゾルＸを混合することによって得た。図２に塗布液の調製手順と各薬液の混合割合（重量比）を示す。先ず、ジメチルシリコーン誘導体；０.０３ｇとメチルエチルケトン；７.００ｇとイソプロピルアルコール；７.００ｇを混合し、約５分間攪拌した後、上記シリカゾルＸ；０.７８ｇを添加し、約１５時間室温で攪拌した。次いで、メチルエチルケトン；２６.５０ｇとイソプロピルアルコール；２６.５０ｇすることによって塗布液を調製した。
【００５０】
〔ガラス基板の洗浄〕
３００ｍｍ×３００ｍｍ×２ｍｍ（厚）サイズのフロートガラスの表面を研磨液で研磨し、ガラス洗浄機（当所製作品）にて水洗および乾燥した。なお、ここで用いた研磨液は、約１％のガラス用研摩剤ミレークＡ(Ｔ)（三井金属鉱業製）を水に混合した懸濁液を用いた。
【００５１】
〔凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜の作製〕
上記塗布液をスピンコート法によりガラス基板上に塗布した。先ず、スピンコーター上に上記〔ガラス基板の洗浄〕に記載した要領で洗浄したガラス基板を設置し、回転速度が７５ｒｐｍの速度で回転させながら約４０ｍｌの塗布液を滴下し、３０秒間回転速度を維持して塗膜の乾燥を行い、良好な成膜性の透明ゲル膜を得た。次いで、２５０℃で１０分間熱処理を行い、室温まで冷却させて凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜を得た。
【００５２】
〔ゾルゲル膜の表面観察〕
原子間力顕微鏡（ＡＦＭ：セイコー電子工業製 ＳＰＩ-３７００）を用いて、ゾルゲル膜の表面形状の観察を行った。観察時のスキャン範囲は、２５μｍ×２５μｍまたは３μｍ×３μｍとした。
【００５３】
〔耐久性の評価〕
スチールウール（＃００００）でゾルゲル膜表面を１０往復手拭きし、手拭き作業後に傷の発生または膜の剥離が起こらなかったものを高耐久膜とした。
【００５４】
実施例１
平均重合度が５０（平均分子量；２０００）のジメチルシリコーン誘導体〔(CH₃O)₃SiCH₂CH₂[Si(CH₃)₂O]₅₀Si(CH₃)₂CH₂CH₂Si(OCH₃)₃〕を用い、上記〔塗布液の調製〕に記載の要領で塗布液を調製した。このときの溶媒組成は重量比でメチルエチルケトン：イソプロピルアルコール：水＝４９.９：４９.９：０.２であった。次いで、湿度が６９ＲＨ％の雰囲気の下で上記〔凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜の作製〕に記載した要領にて膜厚２０ｎｍのゾルゲル膜を得た。
【００５５】
得られたゾルゲル膜の表面を上記〔ゾルゲル膜の表面観察〕に記載した方法で表面を観察した結果、表面は図３に示すように約５μｍ周期、くぼみ部の底部の最大径が約３μｍの凹状の表面形状であった。又、〔耐久性の評価〕に記載した方法で耐久性を評価した結果、高耐久な膜であった。なお、表１にゾルゲル膜の作製条件、表２に得られたゾルゲル膜の表面形状について示す。
【００５６】
【表１】

【００５７】
【表２】

【００５８】
実施例２
平均重合度が７５（平均分子量；４０００）のジメチルシリコーン誘導体〔(CH₃O)₃SiCH₂CH₂[Si(CH₃)₂O]₇₅Si(CH₃)₂CH₂CH₂Si(OCH₃)₃〕を用いた以外は実施例１と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。
【００５９】
結果、表面は図４に示すように約７μｍ周期、くぼみ部の底部の最大径が約４μｍの凹状の表面形状であり、高耐久な膜であった。
【００６０】
実施例３
平均重合度が１００（平均分子量；８０００）のジメチルシリコーン誘導体〔(CH₃O)₃SiCH₂CH₂[Si(CH₃)₂O]₁₀₀Si(CH₃)₂CH₂CH₂Si(OCH₃)₃〕を用いた以外は実施例１と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。
【００６１】
結果、表面は図５に示すように約８μｍ周期、くぼみ部の底部の最大径が約５μｍの凹状の表面形状であり、高耐久な膜であった。
【００６２】
実施例４
平均重合度が１５０（平均分子量；１１５００）のジメチルシリコーン誘導体〔(CH₃O)₃SiO[Si(CH₃)₂O]₁₅₀Si(OCH₃)₃〕を用いた以外は実施例１と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。
【００６３】
結果、表面は図６に示すように１５〜２０μｍ周期、くぼみ部の底部の最大径が１０〜１５μｍの凹状の表面形状であり、高耐久な膜であった。
【００６４】
実施例５
平均重合度が２００（平均分子量；１５０００）のジメチルシリコーン誘導体〔(CH₃O)₃SiCH₂CH₂[Si(CH₃)₂O]₂₀₀Si(CH₃)₂CH₂CH₂Si(OCH₃)₃〕を用いた以外は実施例１と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。
【００６５】
結果、表面は図７に示すように１５〜２０μｍ周期、くぼみ部の底部の最大径が約１５μｍの凹状の表面形状であり、高耐久な膜であった。
【００６６】
実施例６
平均重合度が３００（平均分子量；２２５００）のジメチルシリコーン誘導体〔(CH₃O)₃SiCH₂CH₂[Si(CH₃)₂O]₃₀₀Si(CH₃)₂CH₂CH₂Si(OCH₃)₃〕を用いた以外は実施例１と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。
【００６７】
結果、表面は図８に示すように１５〜２０μｍ周期、くぼみ部の底部の最大径が１５〜２０μｍの凹状の表面形状であり、高耐久な膜であった。
【００６８】
実施例７
塗布液の溶媒組成をメチルエチルケトン：イソプロピルアルコール：水＝４７.４：４７.４：５.２とした以外は実施例５と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。
【００６９】
結果、表面は図９に示すように１０〜１５μｍ周期、突出部の最表層の最大径が５〜１０μｍの凸状の表面形状であり、高耐久な膜であった。
【００７０】
実施例８
塗布液の溶媒組成をメチルエチルケトン：イソプロピルアルコール：水：イソホロン＝４９.４：４９.４：０.２：１.０とした以外は実施例５と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。
【００７１】
結果、表面は図１０に示すように１０〜１５μｍ周期、くぼみ部の最大対角線が１０〜１５μｍの凹状の表面形状であり、高耐久な膜であった。
【００７２】
の凹状であった。
【００７３】
実施例９
湿度が５３ＲＨ％の雰囲気の下で上記〔凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜の作製〕に記載した要領にてゾルゲル膜を得た以外は実施例５と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。
【００７４】
結果、表面は図１１に示すように約１０μｍ周期、くぼみ部の最大径が約５μｍの凹状の表面形状であり、高耐久な膜であった。
【００７５】
実施例１０
湿度が３２ＲＨ％の雰囲気の下で上記〔凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜の作製〕に記載した要領にてゾルゲル膜を得た以外は実施例５と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。
【００７６】
結果、表面は図１２に示すように約５μｍ周期、くぼみ部の最大径が約３μｍの凹状の表面形状であり、高耐久な膜であった。
【００７７】
比較例１
平均重合度が２５００（平均分子量；１８０００）のジメチルシリコーン誘導体〔(CH₃O)₂(CH₃)SiCH₂CH₂[Si(CH₃)₂O]₂₅₀₀Si(CH₃)₂CH₂CH₂Si(CH₃)(OCH₃)₂〕を用いた以外は実施例１と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。
【００７８】
結果、塗布液は白濁し、均質な膜は得られなかった。
【００７９】
比較例２
平均重合度が３（平均分子量；５６２）のジメチルシリコーン誘導体〔(CH₃O)₂(CH₃)SiCH₂CH₂[Si(CH₃)₂O]₃Si(CH₃)₂CH₂CH₂Si(CH₃)(OCH₃)₂〕を用いた以外は実施例１と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。
【００８０】
結果、塗布液は白濁し、均質な膜は得られなかった。
【００８１】
比較例３
平均重合度が７０（平均分子量；５２００）のジメチルシリコーン誘導体〔CH₃O[Si(CH₃)₂O]₇₀Si(CH₃)₂OCH₃〕を用いた以外は実施例１と同じ操作で膜厚２０ｎｍのゾルゲル膜を得た。すなわち、本比較例では、各末端のアルコキシ基数が１であるジメチルシリコーン誘導体を用いた。
【００８２】
結果、表面は図１３に示すように平坦であった。
【００８３】
比較例４
平均分子量が約３，０００で固形分濃度が３０ｗｔ％のメチルトリエトキシシラン溶液２０ｇと、平均分子量が１００，０００で固形分濃度が６ｗｔ％のシリコンエトキシド溶液２９ｇを混合し、重量比でメチルエチルケトン：イソプロピルアルコール：水＝４９.９：４９.９：０.２の溶媒２００ｇを添加し、約８時間攪拌後、約２週間熟成して塗布液を得た。次いで、湿度が６０％の雰囲気の下で上記〔凸状又は凹状若しくは凹凸状の表面形状を有するゾルゲル膜の作製〕に記載した要領にて膜厚１００ｎｍのゾルゲル膜を得た。
【００８４】
結果、表面は図１４に示すように約０．１μｍ周期の凸状であったが、耐久性評価にて膜が剥離した。
【００８５】
【発明の効果】
本発明のゾルゲル膜は、凸状又は凹状若しくは凹凸状の表面形状を有する高強度な膜をより低温で形成することができ、目的に応じて、任意に種々の大きさや間隔の凸状又は凹状若しくは凹凸状の表面形状を有する膜を基材上に形成できる。又、表面の滑り性由来で耐久性が向上する。さらに、該ゾルゲル膜上に撥水膜等の機能性膜を形成した場合にも該積層膜はゾルゲル膜の滑り性を保持し、滑り性由来の耐久性を発揮するので、特に自動車用窓ガラス、建築用窓ガラス等の産業用窓ガラスへの使用に奏効する。
【図面の簡単な説明】
【図１】実施例のシリカゾルＸを調製手順。
【図２】実施例の塗布液の調製手順。
【図３】実施例１のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。
【図４】実施例２のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。
【図５】実施例３のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。
【図６】実施例４のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。
【図７】実施例５のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。
【図８】実施例６のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。
【図９】実施例７のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。
【図１０】実施例８のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。
【図１１】実施例９のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。
【図１２】実施例１０のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。
【図１３】比較例３のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。
【図１４】比較例４のゾルゲル膜のＡＦＭ観察による表面微細形状の図面代用写真。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sol-gel film having a unique surface shape that can be coated on, in particular, architectural windows, vehicle windows, mirrors, and other industrial windows.
[0002]
[Prior art]
The thin film formed by controlling the surface shape has excellent properties as an intermediate layer that tightly links the functional thin film and the substrate, and in the case of a low-reflective, diffuse-reflective, or hydrophilic film, the surface area of the surface layer In the case of a water-repellent film, excellent characteristics such as a property to greatly increase the holding amount per unit area of the water-repellent component to improve the sliding resistance are provided. Conventionally, various methods have been proposed as a method for forming a concave shape, a convex shape, an uneven shape, and the like on the film surface.
[0003]
For example, Patent Literature 1 discloses a method in which a sol-gel film on a substrate is brought into close contact with a molding material having an uneven surface and heated to obtain an uneven film. Patent Literature 2 discloses metal oxide fine particles on a metal oxide film. A method for obtaining a concavo-convex film by introducing a compound is disclosed.
[0004]
The present applicant, as a method different from the above method, a method of obtaining a film having a concave, convex, and irregularities from a mixed sol of two or more metal oxides having different molecular weights in Patent Documents 3 and 4, etc. Patent Document 5 discloses that the surface roughness of the uneven surface can be arbitrarily controlled in the range of several nm to 15 nm by the addition amount of 1,3-butanediol in the solvent of the mixed sol. The methods disclosed in Patent Documents 3 to 5 and the like are methods capable of obtaining a film having a concave shape, a convex shape, an uneven shape, or the like with high transmission and high durability.
[0005]
However, the intervals and sizes of the concave, convex, and uneven shapes of the film obtained by the above method are on the order of several nm to several 100 nm, and the intervals of the concave, convex, and uneven shapes on the order of several tens of μm and the like. In order to obtain a large-sized shape, there is a problem that a molding material is required as in Patent Document 1 and it is not economical. In addition, in order to obtain a highly durable film, baking at 400 ° C. or higher is necessary, and it is expected that usable base materials are limited, and that the film can be formed at a lower baking temperature from an economic viewpoint. Had been rare.
[0006]
[Patent Document 1]
JP-A-11-314927
[Patent Document 2]
JP-A-9-100141
[Patent Document 3]
JP-A-5-319869
[Patent Document 4]
JP-A-6-157076
[Patent Document 5]
JP-A-9-315538
[0007]
[Problems to be solved by the invention]
The present invention is to provide a sol-gel film having a surface shape such as a concave shape, a convex shape, and a concave-convex shape which is excellent in durability without requiring high-temperature sintering. It is an object of the present invention to provide a coating liquid and a production method that can be controlled to the intervals and sizes of the coating liquids.
[0008]
[Means for Solving the Problems]
The present invention has been made in view of the above problems. That is, the present invention provides a sol-gel film comprising a composition of silica and dimethyl silicone, wherein the film has a convex, concave, or uneven surface shape, and the dimethyl silicone has an average polymerization represented by the general formula [1]. A sol-gel film characterized by being a dimethyl silicone derivative having a degree of 5 or more and 2000 or less.
[0009]
Embedded image

[0010]
Here, p and q are integers of 2 to 3, n is an integer of 5 to 2000, A ¹ , A ^Two Represents a divalent alkylene group or oxygen, respectively, and indicates that at least one terminal oxygen is bonded to silicon.
[0011]
Further, the composition ratio of silica and the dimethyl silicone derivative is preferably from 1: 0.0001 to 1:10 by weight. When the sol-gel film has the above structure, the sol-gel film having the convex layer and / or the concave layer can have high durability without requiring high-temperature sintering.
[0012]
The coating solution for obtaining the sol-gel film is characterized by comprising a solvent, silica sol, and an alkoxy-terminated dimethylsilicone derivative having an average polymerization degree represented by the general formula [2] of 5 to 2,000.
[0013]
Embedded image

[0014]
Here, R is a monovalent alkyl group, p and q are integers of 2 to 3, n is an integer of 5 to 2000, ¹ , A ^Two Represents a divalent alkylene group or oxygen, respectively.
[0015]
Further, the solvent preferably contains at least water, and the amount of water in the coating solution is preferably 0.01% by weight or more and 10% by weight or less. The coating liquid is preferably obtained by mixing a silica sol obtained by hydrolysis and polycondensation of alkoxysilane with an alkoxy group-terminated dimethyl silicone derivative.
[0016]
The surface shape of the sol-gel film can be controlled to a desired shape or interval by selecting the range of the degree of polymerization of the alkoxy group-terminated dimethyl silicone derivative within the above range and adjusting the amount of water in the coating solution.
[0017]
The method for producing a sol-gel film of the present invention is characterized in that the above-mentioned coating solution is applied to a substrate, and a solvent is volatilized to form a film. Further, in order to control the convex layer and / or the concave layer on the surface of the sol-gel film to have a desired shape and interval, it is preferable to adjust the humidity when applying the coating liquid to the substrate.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
The sol-gel film of the present invention is a sol-gel film composed of a composition of silica and dimethyl silicone, wherein the film has a convex, concave, or uneven surface shape, and the dimethyl silicone is represented by the general formula [1]. A sol-gel film characterized by being a dimethyl silicone derivative having an average degree of polymerization of 5 or more and 2000 or less.
[0019]
Embedded image

[0020]
Here, p and q are integers of 2 to 3, n is an integer of 5 to 2000, A ¹ , A ^Two Represents a divalent alkylene group or oxygen, respectively, and indicates that at least one terminal oxygen is bonded to silicon.
[0021]
The sol-gel film having a convex, concave, or uneven surface shape is made of a composition with silica and a dimethylsilicone derivative in the conventional sol-gel film having a convex, concave, or uneven surface shape. This is because, in view of the above, problems such as easy attachment to contaminants such as mist and oil, and a decrease in abrasion resistance and abrasion resistance due to the attachment are considered. The lubricity of the dimethyl silicone derivative improves the slipperiness of the film surface, and as a result, improves the slipperiness of the film surface, makes it difficult for contaminants to adhere, and improves the durability of the film. In addition, when the sol-gel film is formed on the base material, the slip property of the film surface is expressed only by evaporating the solvent of the coating solution applied on the base material. A sol-gel having a highly durable convex, concave, or uneven surface shape by drying at room temperature or firing at a low temperature of less than 400 ° C. without requiring high-temperature baking at 400 ° C. or higher to increase the durability of the sol-gel film having a surface shape. Since a film can be obtained, effects such as cost reduction and a wider choice of base materials are exhibited.
[0022]
The reason why p and q of the dimethylsilicone derivative represented by the general formula [1] are integers of 2 or 3 is that silica and the dimethylsilicone derivative are firmly bonded to form a high-strength film. Here, it is shown that at least one of the terminal oxygens is bonded to silicon. The reason why n is an integer of 5 to 2000 is that if the value is less than 5, the effect of improving the slipperiness of the film surface by the dimethyl silicone derivative is small, and if it exceeds 2000, it is difficult to obtain a uniform film.
[0023]
The composition ratio of silica to the dimethyl silicone derivative is preferably from 1: 0.0001 to 1:10 by weight. In the composition region where the dimethyl silicone derivative is smaller than the above composition ratio, the effect of improving the slipperiness of the film surface is small, and in the composition region where the composition ratio is larger than the above composition ratio, it is difficult to obtain a uniform film.
[0024]
The convex surface shape according to the present invention is one in which protrusions are formed on the film surface at a period of 0.3 μm to 90 μm, preferably 1 μm to 30 μm. The size of the outermost surface of the protrusion is the largest diagonal when the protrusion is polygonal, and the largest diameter when the protrusion is arc-shaped is 0.1 to 1 times the period. It is preferable that The height of the protrusion is preferably 2 to 100 nm.
[0025]
The term “concave surface shape” refers to a shape in which depressions are formed on the film surface at a period of 0.3 μm to 90 μm, preferably 1 μm to 30 μm. The size of the bottom of the concave portion is the largest diagonal line when the concave portion is polygonal, and the maximum diameter when the concave portion is arc-shaped is 0.1 to 1 times the period. Is preferred. It is preferable that the depth of the recess is 2 nm to a film thickness.
[0026]
Further, the uneven surface shape has both the convex surface shape and the concave surface shape.
[0027]
A sol-gel film having a convex, concave, or uneven surface shape composed of a composition of silica and a dimethylsilicone derivative controls the height of the convex protrusion and the depth of the concave depression, depending on the film thickness. As the film thickness increases, the protrusion height and the depression depth increase. It is preferable that the thickness is 10 nm or more and 500 nm or less. If the film thickness is less than 10 nm, it becomes difficult to form a uniform coating film on the substrate, and if it exceeds 500 nm, the film strength is not only weakened, but also cracks are liable to occur, which is not preferable.
[0028]
The sol-gel film of the present invention may contain components other than silica and a dimethyl silicone derivative. These components include, but are not limited to, organic polymers, inorganic fine particles, surfactants, silane coupling agents and the like.
[0029]
The present invention also provides a coating solution for forming the sol-gel film, wherein the coating solution is a solvent, silica sol, and an alkoxy group-terminated dimethyl having an average degree of polymerization represented by the general formula [2] of 5 to 2,000. And a silicone derivative. The silica sol becomes silica after film formation, and the alkoxy-terminated dimethyl silicone derivative represented by the general formula [2] becomes an alkoxy-terminated dimethyl silicone derivative represented by the general formula [1] after film formation.
[0030]
Embedded image

[0031]
Here, R is a monovalent alkyl group, p and q are integers of 2 to 3, n is an integer of 5 to 2000, ¹ , A ^Two Represents a divalent alkylene group or oxygen, respectively.
[0032]
The reason why p and q of the alkoxy group-terminated dimethylsilicone derivative represented by the general formula [2] are integers of 2 to 3 is to facilitate the cross-linking between the silica sol and the dimethylsilicone derivative, and to obtain the resultant. The film becomes a high-strength film. When p and q are integers of 0 to 1, not only the cross-linking is insufficient, but also the phase separation between the silica sol and the dimethylsilicone derivative is excessive, so that the formed film is formed of silica and dimethylsilicone. It becomes a layered film, and a convex, concave, or uneven surface shape cannot be obtained. The reason why n is an integer of 5 to 2,000 is that if it is less than 5, the effect of improving the slipperiness of the film surface by the dimethyl silicone derivative is small, and if it exceeds 2,000, it is difficult to obtain a uniform coating solution.
[0033]
The average degree of polymerization of the alkoxy group-terminated dimethylsilicone derivative affects the period of the convex or concave or uneven shape of the sol-gel film, and the larger the average polymerization, the larger the period of the convex or concave or uneven shape of the obtained film becomes, A period of several tens of μm can be obtained, and if the average degree of polymerization is selected, a period of a convex shape, a concave shape, or a concave-convex shape can be appropriately selected. Specifically, when the average degree of polymerization is as small as 100 or less and the molecular weight is small, it is likely to be convex, concave, or irregular with a period of 0.3 μm to 9 μm. On the other hand, when a relatively large molecular weight having an average degree of polymerization of more than 100 is used, the surface shape tends to be convex, concave, or irregular having a period of 10 μm to 90 μm.
[0034]
However, since the water content of the coating solution, the solvent composition and the humidity when applying the coating solution to the substrate also affect the period and shape of the convex and / or concave, the average degree of polymerization and / or the period and shape of the concave are Is not limited to the above.
[0035]
The appearance of the surface shape as described above is due to the phase separation phenomenon between the silica sol component and the alkoxy group-terminated dimethyl silicone derivative. The surface shape was changed by changing the average degree of polymerization of the dimethyl silicone derivative, because the average degree of polymerization had a profound effect on the phase separation phenomenon.
[0036]
The solvent preferably contains at least water, and the amount of water in the coating solution is preferably 0.01% by weight or more and 10% by weight or less. If the amount of water in the coating liquid is less than 0.01% by weight, the wettability with the substrate is reduced, and it becomes impossible to form a uniform film on the substrate, which is not preferable. If it exceeds 10% by weight, the solubility of the alkoxy-terminated dimethylsilicone derivative decreases, and a uniform coating liquid cannot be obtained, which is not preferable. When an appropriate amount of water is selected in the above water amount range, a sol-gel film having a convex surface shape and a sol-gel film having a concave surface shape can be appropriately obtained. When the amount of water in the coating liquid is small, the surface shape of the obtained film becomes concave, and when the amount of water is large, it becomes convex.
[0037]
As other solvent components, lower alcohols such as ethyl alcohol and isopropyl alcohol, acidic solutions such as hydrochloric acid, nitric acid, sulfuric acid, and acetic acid, base solutions such as sodium hydroxide and ammonia, or a mixed solvent thereof are preferable. Not limited to, ketones such as acetone, methyl ethyl ketone and isophorone, esters such as ethyl acetate and butyl acetate, aromatic hydrocarbon solvents such as toluene, benzene and xylene, ethers such as diethyl ether and diisopropyl ether, Chlorine solvents such as chloroform and carbon tetrachloride and mixtures thereof can be used.
[0038]
The coating liquid is preferably obtained by mixing an alkoxy group-terminated dimethyl silicone derivative with a silica sol obtained by hydrolysis and polycondensation of alkoxysilane. Examples of the alkoxysilane include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane, methyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and propyltrimethoxysilane. Trialkoxysilanes such as silane and propyltriethoxysilane, or dialkoxysilanes can be used. Of the above alkoxysilanes, tetramethoxysilane, tetraethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane and the like are particularly preferred.
[0039]
For the preparation of the silica sol, for example, a predetermined amount of an alkoxysilane (for example, tetraethoxysilane) and a solvent are mixed and stirred (for example, for about 30 minutes) to obtain a solution A. As the solvent, water, a lower alcohol such as ethyl alcohol and isopropyl alcohol, an acidic solution such as hydrochloric acid, nitric acid, sulfuric acid, and acetic acid, a base solution such as sodium hydroxide and ammonia, or a mixed solvent thereof is preferable. Not limited to, ketones such as acetone, methyl ethyl ketone and isophorone, esters such as ethyl acetate and butyl acetate, aromatic hydrocarbon solvents such as toluene, benzene and xylene, ethers such as diethyl ether and diisopropyl ether, chloroform And chlorinated solvents such as carbon tetrachloride and mixtures thereof. On the other hand, the acidic aqueous solution and the solvent are mixed and stirred to obtain a solution B. Next, after mixing the solution A and the solution B, the mixture is stirred at room temperature to proceed the hydrolysis and polycondensation reaction of the alkoxysilane to obtain a silica sol. The stirring time is preferably from 10 minutes to 6 months, and particularly preferably from 30 minutes to 1 month. However, when stirring is performed at a temperature other than room temperature, the stirring time is not limited thereto. As described above, the hydrolysis of the alkoxysilane can be performed by adding a small amount of water and an acid catalyst such as hydrochloric acid, nitric acid, and acetic acid to the alkoxysilane. By condensation, a silica sol can be obtained. The method for preparing the silica sol is not limited to the above method, but a method of gradually mixing the above-mentioned alkoxysilane diluted with a solvent and an acidic aqueous solution diluted with a solvent is abrupt. This is preferable because a more uniform reaction can be avoided and a more homogeneous reaction can be obtained.
[0040]
By applying the coating liquid on a substrate and evaporating the solvent, a sol-gel film having a highly durable convex or concave or uneven surface shape can be obtained, but in order to promote the evaporation of the solvent. Baking can be performed. Although baking can be performed at 400 ° C. to 800 ° C., it is preferable to bake at 100 ° C. to 400 ° C., more preferably 150 ° C. to 300 ° C., from an economic viewpoint.
[0041]
Means for applying the coating solution on a substrate include a nozzle flow coating method, a dipping method, a spraying method, a reverse coating method, a flexo method, a printing method, a flow coating method, a spin coating method, and a method thereof. Various coating methods such as a known coating method such as a combination use can be appropriately adopted.
[0042]
Since the humidity when applying the coating liquid to the base material affects the period of the convex, concave, or uneven shape of the formed sol-gel film, when applying the coating liquid to the base material, the humidity should be adjusted. Is preferred. In order to obtain the sol-gel film, the humidity can be adjusted in the range of 30% to 70%, and the higher the humidity, the larger the period of the convex, concave, or uneven shape.
[0043]
A typical example of the substrate is glass. The glass is a plate glass generally used for automotive, architectural, industrial glass and the like, and is a plate glass by a float method, a duplex method, a roll-out method, etc., and its production method is not particularly limited.
[0044]
As a glass type, it can be used for various colored glasses such as clear and green, bronze and the like, and various functional glasses such as UV, IR cut glass and electromagnetic shielding glass, netted glass, low expansion glass, fire resistant glass such as zero expansion glass. Various glass products such as glass, tempered glass and similar glasses, laminated glass, double-layered glass, mirrors made by a silver drawing method or a vacuum film forming method, and flat and bent plates can be used. The plate thickness is preferably from 1.0 mm to 10 mm, and the thickness is preferably from 1.0 mm to 5.0 mm for automobiles. The formation of the sol-gel film on the substrate may be performed on only one side of the substrate, or may be performed on both sides. Further, the formation of the sol-gel film may be on the entire surface or a part of the substrate surface.
[0045]
In addition, the substrate is not limited to glass, resin films such as polyethylene terephthalate having light transmissivity and light reflectivity, resins such as polycarbonate, metals, ceramics, etc., are not deformed during the solvent evaporation. Can be used.
[0046]
In the case where the sol-gel film of the present invention is used as a base film and a functional film made of fluoroalkylsilane or the like is formed thereon to form a laminated film, the laminated film retains the slip property of the sol-gel film and exhibits durability derived from the slip property. It works well.
[0047]
【Example】
Hereinafter, examples of the present invention will be described.
[0048]
(Preparation of silica sol)
Silica sol is made of tetraethoxysilane [Si (OC _Two H _Five ) _Four : TEOS] by a hydrolysis and polycondensation reaction. FIG. 1 shows the procedure for preparing the silica sol and the mixing ratio (weight ratio) of each component. First, 312.5 g of TEOS and 450.0 g of Echinene F1 (a mixture of lower alcohols composed of 90% by weight of ethanol and 10% by weight of isopropyl alcohol) were mixed and stirred for about 30 minutes (solution A). Also, a 60% nitric acid aqueous solution; 7.5 g, H _Two 210.0 g of O and 20.0 g of echinene F1 were mixed and stirred for about 30 minutes (solution B). Next, the solution A and the solution B were mixed and stirred at room temperature for about 15 hours to obtain a silica sol X.
[0049]
(Preparation of coating liquid)
The coating liquid was obtained by mixing the dimethyl silicone derivative and the silica sol X obtained in the above [Preparation of silica sol]. FIG. 2 shows the preparation procedure of the coating solution and the mixing ratio (weight ratio) of each chemical solution. First, a dimethyl silicone derivative; 0.03 g and methyl ethyl ketone; 7.00 g and isopropyl alcohol; 7.00 g are mixed and stirred for about 5 minutes, and then the above silica sol X; 0.78 g is added and stirred for about 15 hours at room temperature. did. Next, 26.50 g of methyl ethyl ketone and 26.50 g of isopropyl alcohol were prepared to prepare a coating solution.
[0050]
(Washing of glass substrate)
The surface of a float glass having a size of 300 mm × 300 mm × 2 mm (thickness) was polished with a polishing liquid, washed with a glass washer (manufactured by us), and dried. The polishing liquid used here was a suspension obtained by mixing about 1% of a glass polishing agent MIRAKE A (T) (manufactured by Mitsui Mining & Smelting) with water.
[0051]
[Production of a sol-gel film having a convex or concave or uneven surface shape]
The coating solution was applied on a glass substrate by spin coating. First, a glass substrate washed in the manner described in the above [Washing of glass substrate] is placed on a spin coater, and about 40 ml of a coating liquid is dropped while rotating at a rotation speed of 75 rpm, and the rotation speed is increased for 30 seconds. The coating film was dried while maintaining the same to obtain a transparent gel film having good film forming properties. Next, heat treatment was performed at 250 ° C. for 10 minutes, and the resultant was cooled to room temperature to obtain a sol-gel film having a convex, concave, or uneven surface shape.
[0052]
(Sol-gel film surface observation)
The surface shape of the sol-gel film was observed using an atomic force microscope (AFM: SPI-3700 manufactured by Seiko Denshi Kogyo). The scan range during observation was 25 μm × 25 μm or 3 μm × 3 μm.
[0053]
[Evaluation of durability]
The surface of the sol-gel film was hand-wiped 10 times with steel wool (# 0000), and a film having no scratches or peeling after the manual wiping operation was defined as a highly durable film.
[0054]
Example 1
A dimethyl silicone derivative having an average degree of polymerization of 50 (average molecular weight: 2000) [(CH _Three O) _Three SiCH _Two CH _Two [Si (CH _Three ) _Two O] ₅₀ Si (CH _Three ) _Two CH _Two CH _Two Si (OCH _Three ) _Three And a coating solution was prepared in the same manner as described in [Preparation of coating solution]. The solvent composition at this time was methyl ethyl ketone: isopropyl alcohol: water = 49.9: 49.9: 0.2 in weight ratio. Then, a sol-gel film having a thickness of 20 nm was obtained in an atmosphere having a humidity of 69 RH% in the manner described in the above [Production of a sol-gel film having a convex, concave, or uneven surface shape].
[0055]
As a result of observing the surface of the obtained sol-gel film by the method described in [Sol-gel film surface observation] above, as shown in FIG. 3, the surface has a period of about 5 μm, and the maximum diameter of the bottom of the depression is about 3 μm. The surface was concave. The durability was evaluated by the method described in [Evaluation of Durability]. As a result, the film was highly durable. Table 1 shows conditions for preparing the sol-gel film, and Table 2 shows the surface shape of the obtained sol-gel film.
[0056]
[Table 1]

[0057]
[Table 2]

[0058]
Example 2
A dimethyl silicone derivative having an average degree of polymerization of 75 (average molecular weight: 4000) [(CH _Three O) _Three SiCH _Two CH _Two [Si (CH _Three ) _Two O] ₇₅ Si (CH _Three ) _Two CH _Two CH _Two Si (OCH _Three ) _Three ] Was used in the same manner as in Example 1 to obtain a sol-gel film having a thickness of 20 nm.
[0059]
As a result, as shown in FIG. 4, the surface had a concave surface shape with a period of about 7 μm and a maximum diameter of the bottom of the hollow of about 4 μm, and was a highly durable film.
[0060]
Example 3
A dimethyl silicone derivative having an average degree of polymerization of 100 (average molecular weight: 8000) [(CH _Three O) _Three SiCH _Two CH _Two [Si (CH _Three ) _Two O] ₁₀₀ Si (CH _Three ) _Two CH _Two CH _Two Si (OCH _Three ) _Three ] Was used in the same manner as in Example 1 to obtain a sol-gel film having a thickness of 20 nm.
[0061]
As a result, as shown in FIG. 5, the surface had a concave surface shape with a period of about 8 μm and a maximum diameter at the bottom of the depression of about 5 μm, and was a highly durable film.
[0062]
Example 4
A dimethyl silicone derivative having an average degree of polymerization of 150 (average molecular weight: 11500) [(CH _Three O) _Three SiO [Si (CH _Three ) _Two O] ₁₅₀ Si (OCH _Three ) _Three ] Was used in the same manner as in Example 1 to obtain a sol-gel film having a thickness of 20 nm.
[0063]
As a result, as shown in FIG. 6, the surface had a concave surface shape with a period of 15 to 20 μm and a maximum diameter at the bottom of the depression of 10 to 15 μm, and was a highly durable film.
[0064]
Example 5
A dimethyl silicone derivative having an average degree of polymerization of 200 (average molecular weight: 15000) [(CH _Three O) _Three SiCH _Two CH _Two [Si (CH _Three ) _Two O] ₂₀₀ Si (CH _Three ) _Two CH _Two CH _Two Si (OCH _Three ) _Three ] Was used in the same manner as in Example 1 to obtain a sol-gel film having a thickness of 20 nm.
[0065]
As a result, as shown in FIG. 7, the surface had a concave surface shape with a period of 15 to 20 μm and a maximum diameter of the bottom of the hollow portion of about 15 μm, and was a highly durable film.
[0066]
Example 6
A dimethyl silicone derivative having an average degree of polymerization of 300 (average molecular weight: 22,500) [(CH _Three O) _Three SiCH _Two CH _Two [Si (CH _Three ) _Two O] ₃₀₀ Si (CH _Three ) _Two CH _Two CH _Two Si (OCH _Three ) _Three ] Was used in the same manner as in Example 1 to obtain a sol-gel film having a thickness of 20 nm.
[0067]
As a result, as shown in FIG. 8, the surface had a concave surface shape with a period of 15 to 20 μm and a maximum diameter of the bottom of the depression of 15 to 20 μm, and was a highly durable film.
[0068]
Example 7
A sol-gel film having a thickness of 20 nm was obtained in the same manner as in Example 5, except that the solvent composition of the coating solution was changed to methyl ethyl ketone: isopropyl alcohol: water = 47.4: 47.4: 5.2.
[0069]
As a result, as shown in FIG. 9, the surface had a convex surface shape with a period of 10 to 15 μm and a maximum diameter of the outermost layer of the protrusion of 5 to 10 μm, and was a highly durable film.
[0070]
Example 8
A sol-gel film having a thickness of 20 nm was obtained in the same manner as in Example 5, except that the solvent composition of the coating solution was changed to methyl ethyl ketone: isopropyl alcohol: water: isophorone = 49.4: 49.4: 0.2: 1.0. .
[0071]
As a result, as shown in FIG. 10, the surface had a concave surface shape with a period of 10 to 15 μm and a maximum diagonal line of the depression of 10 to 15 μm, and was a highly durable film.
[0072]
Was concave.
[0073]
Example 9
A film thickness was obtained by the same operation as in Example 5 except that a sol-gel film was obtained in the atmosphere described above [Preparation of a sol-gel film having a convex, concave, or irregular surface shape] under an atmosphere of a humidity of 53 RH%. A 20 nm sol-gel film was obtained.
[0074]
As a result, as shown in FIG. 11, the surface had a concave surface shape with a period of about 10 μm and a maximum diameter of the concave portion of about 5 μm, and was a highly durable film.
[0075]
Example 10
A film thickness was obtained by the same operation as in Example 5 except that a sol-gel film was obtained in the manner described in [Production of a sol-gel film having a convex, concave, or uneven surface shape] under an atmosphere of a humidity of 32 RH%. A 20 nm sol-gel film was obtained.
[0076]
As a result, as shown in FIG. 12, the surface had a concave surface shape with a period of about 5 μm and a maximum diameter of the concave portion of about 3 μm, and was a highly durable film.
[0077]
Comparative Example 1
A dimethyl silicone derivative having an average degree of polymerization of 2500 (average molecular weight: 18000) [(CH _Three O) _Two (CH _Three ) SiCH _Two CH _Two [Si (CH _Three ) _Two O] ₂₅₀₀ Si (CH _Three ) _Two CH _Two CH _Two Si (CH _Three ) (OCH _Three ) _Two ] Was used in the same manner as in Example 1 to obtain a sol-gel film having a thickness of 20 nm.
[0078]
As a result, the coating solution became cloudy, and a uniform film was not obtained.
[0079]
Comparative Example 2
A dimethyl silicone derivative having an average degree of polymerization of 3 (average molecular weight: 562) [(CH _Three O) _Two (CH _Three ) SiCH _Two CH _Two [Si (CH _Three ) _Two O] _Three Si (CH _Three ) _Two CH _Two CH _Two Si (CH _Three ) (OCH _Three ) _Two ] Was used in the same manner as in Example 1 to obtain a sol-gel film having a thickness of 20 nm.
[0080]
As a result, the coating solution became cloudy, and a uniform film was not obtained.
[0081]
Comparative Example 3
A dimethyl silicone derivative having an average degree of polymerization of 70 (average molecular weight: 5200) [CH _Three O [Si (CH _Three ) _Two O] ₇₀ Si (CH _Three ) _Two OCH _Three ] Was used in the same manner as in Example 1 to obtain a sol-gel film having a thickness of 20 nm. That is, in this comparative example, a dimethyl silicone derivative in which the number of alkoxy groups at each terminal was 1 was used.
[0082]
As a result, the surface was flat as shown in FIG.
[0083]
Comparative Example 4
A mixture of 20 g of a methyltriethoxysilane solution having an average molecular weight of about 3,000 and a solid content of 30 wt% and 29 g of a silicon ethoxide solution having an average molecular weight of 100,000 and a solid content of 6 wt% is mixed in a weight ratio of methyl ethyl ketone. : Isopropyl alcohol: water = 49.9: 49.9: 0.2 A solvent (200 g) was added, and the mixture was stirred for about 8 hours and then aged for about 2 weeks to obtain a coating solution. Then, a sol-gel film having a thickness of 100 nm was obtained in an atmosphere having a humidity of 60% according to the procedure described in [Production of a sol-gel film having a convex, concave, or uneven surface shape].
[0084]
As a result, as shown in FIG. 14, the surface was convex with a period of about 0.1 μm, but the film was peeled off in the durability evaluation.
[0085]
【The invention's effect】
The sol-gel film of the present invention can form a high-strength film having a convex or concave surface or uneven surface shape at a lower temperature, and optionally has various shapes or intervals of convex or concave shape depending on the purpose. Alternatively, a film having an uneven surface shape can be formed on a substrate. In addition, durability is improved due to the slipperiness of the surface. Further, even when a functional film such as a water-repellent film is formed on the sol-gel film, the laminated film retains the slidability of the sol-gel film and exhibits durability derived from the slidability. It is effective for use in industrial window glass such as architectural window glass.
[Brief description of the drawings]
FIG. 1 shows a procedure for preparing a silica sol X of an example.
FIG. 2 is a procedure for preparing a coating solution of an example.
FIG. 3 is a drawing substitute photograph of a fine surface shape of the sol-gel film of Example 1 observed by AFM.
FIG. 4 is a drawing substitute photograph of the fine surface shape of the sol-gel film of Example 2 observed by AFM.
FIG. 5 is a drawing substitute photograph of a fine surface shape of the sol-gel film of Example 3 by AFM observation.
FIG. 6 is a drawing substitute photograph of the fine surface shape of the sol-gel film of Example 4 by AFM observation.
FIG. 7 is a drawing substitute photograph of the fine surface shape of the sol-gel film of Example 5 by AFM observation.
FIG. 8 is a drawing substitute photograph of the fine surface shape of the sol-gel film of Example 6 by AFM observation.
FIG. 9 is a drawing substitute photograph of a fine surface shape of the sol-gel film of Example 7 observed by AFM.
FIG. 10 is a drawing substitute photograph of the fine surface shape of the sol-gel film of Example 8 observed by AFM.
FIG. 11 is a drawing substitute photograph of the fine surface shape of the sol-gel film of Example 9 observed by AFM.
FIG. 12 is a drawing substitute photograph of the fine surface shape of the sol-gel film of Example 10 observed by AFM.
FIG. 13 is a drawing substitute photograph of the fine surface shape of the sol-gel film of Comparative Example 3 observed by AFM.
FIG. 14 is a drawing substitute photograph of the fine surface shape of the sol-gel film of Comparative Example 4 by AFM observation.

Claims (7)

A sol-gel film composed of a composition of silica and dimethyl silicone, wherein the sol-gel film has a convex, concave, or uneven surface shape, and the dimethyl silicone has an average degree of polymerization represented by the general formula [1]. A sol-gel film comprising 5 to 2000 dimethyl silicone derivatives.

Here, p and q are integers of 2 to 3, n is an integer of 5 to 2000, A ¹ and A ² each represent a divalent alkylene group or oxygen, and at least one of terminal oxygens is silicon. It shows that it is connected with. 2. The sol-gel film according to claim 1, wherein the composition ratio of silica and the dimethyl silicone derivative is 1: 0.0001 to 1:10 by weight. The coating solution for forming a sol-gel film according to claim 1 or 2, comprising a solvent, a silica sol, and an alkoxy group-terminated dimethylsilicone derivative having an average degree of polymerization of 5 to 2000 represented by the general formula [2]. .

Here, R is a monovalent alkyl group, p and q are integers of 2 to 3, n is an integer of 5 to 2000, and A ¹ and A ² are each a divalent alkylene group or oxygen. The coating liquid according to claim 3, wherein the coating liquid contains water, and the amount of water in the coating liquid is 0.1% by weight or more and 10% by weight or less. The silica sol is obtained by hydrolysis and polycondensation of alkoxysilane, and the silica sol is obtained by mixing the alkoxy-terminated dimethyl silicone derivative with the silica sol. Item 6. The coating solution according to Item 4. A method for producing a sol-gel film, comprising applying the coating solution according to any one of claims 3 to 5 to a substrate and volatilizing the solvent to form a film. The method for producing a sol-gel film according to claim 6, wherein the humidity at the time of applying the coating liquid to the substrate is adjusted.

Images