JP3610627B2 - Coating liquid, method for producing the same, and coating film - Google Patents

Description

等のメチルアクリレート系、
【００４４】
【化６】

等のエポキシ系、
【００４５】
【化７】
Ｈ_２ ＮＣ_３ Ｈ_６ Ｓｉ（ＯＣ_２ Ｈ_５ ）_３ 、
Ｈ_２ ＮＣ_２ Ｈ_４ ＮＨＣ_３ Ｈ_６ Ｓｉ（ＯＣＨ_３ ）_３Ｓｉ（ＯＣＨ_３ ）_３ 、
Ｈ_２ ＮＣＯＮＨＣ_３ Ｈ_６ Ｓｉ（ＯＣ_２ Ｈ_５ ）_３ 、
等のアミノ系、
【００４６】
【化８】
ＣＨ_２ ＝ＣＨＳｉ（ＯＣ_２ Ｈ_５ ）_３ 、
ＣＨ_２ ＝ＣＨＳｉ（ＯＣＨ_３ ）_３ 、
ＣＨ_２ ＝ＣＨＳｉ（ＯＣ_２ Ｈ_４ ＯＣＨ_３ ）_３ 、
等のビニル系、
【００４７】
【化９】
ＨＳ−Ｃ_３ Ｈ_６Ｓｉ（ＯＣＨ_３ ）_３ 、 ＨＳ−Ｃ_３ Ｈ_６Ｓｉ（ＯＣ_２ Ｈ_５ ）_３ 、
ＨＳ−Ｃ_３ Ｈ_６Ｓｉ（ＯＣ_２ Ｈ_４ ＯＣＨ_３ ）_３ 、
等のメルカプト系、
等が挙げられる。
【００４８】
これらはいずれも好適に用いることができるが、コーティングを施す基材の種類により適宜選択することも可能である。
例えば、アクリル樹脂基材であればメチルアクリレート系、その他一般の樹脂基材であればビニル系、金属基材であればエポキシ系シランカップラーを選択すれば、特に密着性の優れたコーティングを得ることができる。基材がガラス基材であれば、いずれのシランカップラーを用いても、優れた密着性を得ることができる。
【００４９】
また、（ｉｉ）のアルキルアルコキシシリコーン類としては、
【化１０】
（ＣＨ_３Ｏ）_３Ｓｉ−｛ＯＳｉ（ＣＨ_３）_２ ｝_ｎ −｛ＯＳｉ（ＯＣＨ_３）_２ ｝_ｍ −ＯＣＨ_３
ｎ，ｍ＝１〜１０
等が挙げられる。
【００５０】
さらに、（ｉｉｉ ）のポリマー類としては、たとえば次のようなものが挙げられる。
【００５１】
▲１▼ アクリル樹脂
（ａ）
【化１１】

【００５２】
（ｂ）
上記（ａ）構造にγ−ＭＴＳ（γ−メタクリロキシプロピルトリメトキシシランを付加したもの
【００５３】
【化１２】

【００５４】
【化１３】

【００５５】
これらは本発明で用いることのできる反応性有機化合物の例示であり、本発明で用いることのできる反応性有機化合物はこれらに限られるものではなく、本発明の趣旨で述べたように、上述した熟成物と縮合反応し得る官能基を２以上有するものであれば、何れも用いることができる。
また、上記の反応性有機化合物は、目的に応じて２種以上を併用することもできる。
【００５６】
例えば、エポキシ樹脂とエポキシ系シランカップラー、アクリル樹脂とアクリル系シランカップラー、ポリエステル樹脂とエポキシ系シランカップラー等、樹脂成分とシランカップラーとを併用することにより、基材との密着性が向上し、また樹脂成分とテトラメトキシシランとの相溶性が更に向上し得られるコーティング膜の特性が更に優れたものとなる等、目的に応じ適宜選択することができる。尚、併用に際しては、２種以上を予め配合しても、各々を熟成物に添加してもよい。
【００５７】
反応性有機化合物の添加量は、固形分として、通常、熟成物１００重量部に対し、１〜３００重量部、好ましくは４〜１５０重量部の範囲である。膜中ＳｉＯ_２濃度が９４〜５％、好ましくは８０〜１０％となる範囲で、特に優れた膜特性及び液での貯蔵安定性が発現できる。
反応性有機化合物の量が多すぎると、得られるコーティング膜の硬度が低くなる傾向にあり、またコーティング液の貯蔵安定性が低下する傾向にある。また、反応性有機化合物が少なすぎると、コーティング膜の可撓性が低下し、クラックが発生しやすい。
【００５８】
尚、反応性有機化合物としてシランカップラーを使用する場合、これを加水分解するために水を添加する。この際シランカップラーと共に添加しても、或は予めテトラメトキシシランを加水分解するために加水分解１００％当量以上の水を添加する際に、共に添加しておいても差支えない。
これら熟成物と反応性有機化合物との配合に際しては、必要に応じて、溶媒、分散媒、硬化触媒等を添加することができる。
【００５９】
例えば後述する成膜に際し、特にスプレー法、ディップ法による場合、塗工条件、膜厚等の目的膜物性に応じた粘度、不揮発成分含有量を有するコーティング液を調製するため、これら溶媒又は分散媒の添加を行うことができる。
溶媒としては熟成物と反応製有機化合物の双方に相溶性を持つものが好適であり、例えばアルコール類、あるいはグリコール誘導体、炭化水素類、エステル類、ケトン類、エーテル類を１種、または２種以上混合して使用できる。
【００６０】
アルコール類としては具体的にはメタノール、エタノール、イソプロピルアルコール、ｎ−ブタノール、イソブタノール、オクタノール等が挙げられ、グリコール誘導体としてはエチレングリコール、エチレングリコールモノメチルエーテル、エチレングリコールモノエチルエーテル、エチレングリコールモノｎ−プロピルエーテル、エチレングリコールモノｎ−ブチルエーテル等が挙げられる。
【００６１】
炭化水素類としてはベンゼン、ケロシン、トルエン、キシレン等が使用でき、エステル類として、酢酸メチル、酢酸エチル、酢酸ブチル、アセト酢酸メチル、アセト酢酸エチル等が使用できる。アセトン、メチルエチルケトン、メチルイソブチルケトン、アセチルアセトン等のケトン類、エチルエーテル、ブチルエーテル、２−α−メトキシエタノール、２−α−エトキシエタノール、ジオキサン、フラン、テトラヒドロフラン等のエーテル類が使用できる。
【００６２】
場合によっては、分散媒も使用することができる。用いる分散媒としては、たとえば、水−界面活性剤系が好適であり、界面活性剤としてはアニオン、カチオン又はノニオン性のものが一般的である。アニオン性界面活性剤としては、カルボン酸塩、スルホン酸塩、硫酸エステル塩、リン酸エステル等、カチオン性のものとしては、１〜３級アミンの有機もしくは無機酸の塩、四級アンモニウム塩、ポリオキシエチレンアルキルアミン塩等、さらにはノニオン性のものとしては、ソルビタンジアルキルエステル、ソルビタンアルキルエステルのエチレングリコール縮合物、脂肪族アルコールポリエチレングリコール縮合物、アルキルフェノールポリエチレングリコール縮合物、ポリプロピレングリコールポリエチレングリコール縮合物等、が挙げられる。
【００６３】
これらの界面活性剤は、上記熟成物に対して０．１〜５％程度使用するのが一般的であり、分散（乳化）に際しては、適当量の水を用いて、ホモミキサー、コロイドミル、超音波等、公知の方法によることができる。
【００６４】
これら溶媒、分散媒のうち、通常は溶媒を用いるのが、得られるコーティング膜の物性や、コーティング液の安定性が優れているので望ましい。また溶媒の種類についても目的とするコーティング膜の特性、塗工条件等に適したものを選択すればよいが、一般には、例えばベンゼン、トルエン、キシレン等の炭化水素類や、メチルエチルケトン等のケトン類を用いた場合、コーティング膜硬化時の脱溶媒速度が適切であるため、得られるコーティング膜の表面光沢が特に優れたものとなる上、所望の膜厚を容易に得ることができる。
その他、一般に、用いる反応性有機化合物の種類や、所望の膜特性に応じて適宜選択すればよい。
【００６５】
尚、反応性有機化合物の種類によっては、官能基が多く、成膜後の硬化速度向上のために触媒を更に添加するのが望ましい場合もあるが、一般には、熟成物生成の際に添加した触媒で充分である。
これら溶媒及び触媒を使用する際の添加順序は特に限定されず、反応性有機化合物と同時にテトラメトキシシランに添加してもよく、あるいは以下に述べる相溶状態を達成してから添加してもよい。
【００６６】
熟成物と反応性有機化合物との配合に際しては、これらの成分を、望ましい相溶状態とするため、反応性有機化合物を熟成物に添加した後、一定時間放置する。放置することにより、熟成物中に生成しているヒドロキシル基、アルコキシル基等の反応基を持ったテトラメトキシシランの加水分解縮合物と、これと反応し得る官能基を持った反応性有機化合物とが、水素結合による結合、及び部分的に反応していることによる相溶状態となることが考えられる。これにより、得られたコーティング液を成膜すると、溶媒の蒸発とともにテトラメトキシシランの加水分解縮合物と反応性有機化合物の官能基相互の反応が加速されることにより、透明で高硬度のコーティング膜を形成することができる。
【００６７】
放置に要する時間は、用いる有機化合物の種類にもより、これらの分子の大きさ、官能基の量、種類等により一概にはいえないが、例えばシランカップラー等比較的分子量の小さいものであれば、１時間程度で充分であることが多く、また分子量の大きい樹脂成分等であれば、数日放置する必要があるものもある。放置時間が充分であれば、成膜後、透明なコーティング膜となるため、コーティング液中の各成分が相溶状態となっていることが確認できる。なお、ゲル化しない程度に加熱したり、撹拌を行ったりすることにより、相溶状態とするのに要する放置時間を短縮することができる。
【００６８】
こうして得られた本発明のコーティング液をポリマー、金属、セラミック等の基材や線材に含浸法、スピンコーター法、ディップ法、スプレー法等で造膜したり、粉体と混合して造膜する。造膜に際しては、例えばコーティング液を塗布した後、室温で１〜１０分程度放置することにより、脱溶媒を行った後、加熱して、脱水縮合反応による液中の各成分間の架橋反応を進行させ、膜を硬化させることができるが、これに限定されず、目的に応じた硬化方法を選択できる。
【００６９】
例えば予め室温での脱溶媒を行わず直接加熱を行う場合は、適宜消泡剤やレベリング剤など、硬化温度等の使用条件に適した蒸発速度の溶媒等添加剤を添加し、塗膜表面を平滑にすることもできる。また、加熱温度は特に限定されず、充分な時間をかければ低温でもよく、通常−２０〜３００゜Ｃ程度の広範囲の温度で架橋を進行させることができるが、実用的には２０〜２００゜Ｃ程度でよい。硬化に要する時間は用いる触媒にもよるが、効率的には１５０゜Ｃ程度まで昇温すれば数分で充分な硬度を有するコーティング膜を得ることができる。加熱炉はガス炉、電機炉等、汎用炉でよい。また、本発明のコーティング液によれば、充分な熟成によりテトラメトキシシランの加水分解物が微小粒子を形成しているため、樹脂等有機成分との相溶性がよく、架橋反応の進行速度、進行程度が極めて優れている。このため特に加熱工程を要さず、常温で乾燥させ脱溶媒過程を進行させれば、液中各成分の架橋反応も進行し、充分な高硬度を有するコーティング膜を得ることができるので、屋外での使用にも好適である。
【００７０】
尚、常温乾燥により膜硬化を行う場合は、加熱する場合よりもやや長時間を要するが、通常１２時間程度放置すれば充分である。またこの場合、塗工直前に触媒を添加するのが望ましい。ここで用いる触媒としては前述の触媒を用いることもできるが、特に好ましくはジブチル錫ジアセテート、モノブチル錫トリアセテート、モノブチル錫トリオクトエート、ジオクチル錫ジラウレート、ジブチル錫ラウリルメルカプタン、ジブチル錫ジラウレート、ビス（ジブチル錫モノアセテート）オキサイド等の有機錫化合物或いはＮ−β（アミノエチル）γ−アミノプロピルメチルジメトキシシラン、Ｎ−β（アミノエチル）γ−アミノプロピルトリメトキシシラン、Ｎ−β（アミノエチル）γ−アミノプロピルトリエトキシシラン、γ−アミノプロピルトリメトキシシラン、γ−アミノプロピルトリエトキシシラン、Ｎ−フェニル−γ−アミノプロピルトリメトキシシラン等のアミン系硬化触媒が挙げられ、これらのうちでも特にジブチル錫ジアセテート、Ｎ−β（アミノエチル）γ−アミノプロピルトリメトキシシラン、Ｎ−β（アミノエチル）γ−アミノプロピルトリエトキシシランのうち１種又は２種以上が優れた効果がある。
【００７１】
本発明のコーティング液は再塗布性が良いため、用途によっては、乾燥後、さらに再塗布し、乾燥してもよいが、本発明のコーティング液によれば、一回の塗布で１０μｍ以上の膜厚を得ることができる。
塗布自体は常法によることができ、膜厚も適宜選定することができる。
膜厚の選定は、常法によることができ、例えば液中非揮発成分濃度、液の粘度、ディップ法における引上げ速度、スプレー法における噴射時間等を調整したり、再塗布を行ったりすることにより選定できる。更には用いる反応性有機化合物の選択によっても、得られる膜厚は大幅に変化させることができる。
【００７２】
【実施例】
以下、実施例により、更に本発明を詳細に説明する。なお部及び％は特にことわりのない限り重量部及び重量％を示す。
実施例１
〔脱塩素水の製造〕
北九州市の工業用水を、塩素滅菌し、ポリ塩化アルミニウムを凝集沈殿剤として浮遊物を凝集沈殿装置で分離した後、更に砂濾過器で濾過して、工場濾過水とした。この工場濾過水を、陽イオン交換樹脂で処理した後真空脱気し、更に陰イオン交換樹脂、次いで陰・陽イオン交換樹脂で処理することにより０．０５マイクロジーメンス／ｃｍ以下、ｐＨ６〜８、ＳｉＯ_２濃度２０マイクログラム／リットル以下、Ｆｅ ２０マイクログラム／リットル以下、Ａ〓 ２０マイクログラム／リットル以下、Ｃ〓 ２０マイクログラム／リットル以下の、脱気された脱塩素水を得た。
【００７３】
〔テトラメトキシシラン・オリゴマーの合成〕
撹拌機と還流用コンデンサー及び温度計を付けた５００ｍｌの四つ口丸底フラスコに、テトラメトキシシラン２３４ｇとメタノール７４ｇを加えて混合した後、０．０５％塩酸２２．２ｇを加え、内温度６５℃で２時間加水分解縮合反応を行った。
次いでコンデンサーを留出管に取り換え、内温度が１３０℃になるまで昇温し、メタノールを留出させた。このようにして部分加水分解縮合物を得た（加水分解率４０％）。重合度２〜８のオリゴマーが確認され、重量平均分子量は５５０であった。
【００７４】
得られた部分加水分解縮合物（以下、「テトラメトキシシラン・オリゴマー」という）中のモノマー量は５％であった。引き続き１３０℃に加熱したフラスコにテトラメトキシシラン・オリゴマーを入れ、気化したモノマーを不活性ガスと共に系外に排出しながら、１５０℃まで昇温し、３時間保持した。こうして得られたモノマー除去後のテトラメトキシシラン・オリゴマー中のモノマー量は０．２％であった。
【００７５】
〔熟成物の調製〕
こうして得られたテトラメトキシシラン・オリゴマー３０．７７ｇにエタノール６２．４２ｇを添加し、次いでマレイン酸０．３１ｇ及び脱塩素水６．５０ｇを添加した。水の添加量はテトラメトキシシラン・オリゴマーを理論上完全に加水分解する量に対し１１３％である。室温で４日放置し熟成し、熟成物を得た。
【００７６】
〔微小粒子の確認〕
上記の〔熟成物の調製〕で得られた熟成物（組成物Ａ、ＳｉＯ_２換算濃度１６重量％、８．１ｖｏｌ％）、及びこれをエタノールで約４倍に希釈した液（組成物Ｂ、ＳｉＯ_２換算濃度４．３重量％、２ｖｏｌ％）について、以下の条件で、小角Ｘ線散乱による解析を行った。
【００７７】
測定装置：アントンパール社製 クラツキコンパクトカメラ
Ｘ線源：５０ｋＶ、２００ｍＡ、Ｃｕ−Ｋα線をＮｉ−ｆｉｌｔｅｒで単色化。
光学系条件：サンプル−受光スリット間距離＝２０ｃｍ 内真空ｐａｔｈ＝１９ｃｍ
エントランス・スリット＝８０μｍ、受光スリット＝２００μｍ、ｂｅａｍ ｌｅｎｇｔｈ＝１６ｍｍ
【００７８】
試料セル ： 石英キャピラリー（直径約１ｍｍ、肉厚１０μｍ）
その他条件： 室温。 ｓｔｅｐ ｓｃａｎ法 操作範囲 ２θ＝０．０８６〜８．１ｄｅｇ
９０ｓｅｃ／ｐｏｉｎｔ
データ補正：バックグラウンド補正は石英キャピラリーに水を充填した時の散乱を用いて補正した。Ｘ線吸収補正も行った。
解析ソフト：スリット補正及び逆フーリエ変換は解析ソフトＩＴＰ−８１（Ｏ．Ｇｌａｔｔｅｒ； Ｊ．Ａｐｐｌ．Ｃｒｙｓｔ．， １０． ４１５−４２１（１９７７）による。）を使用した。
【００７９】
図‐１及び図‐２に、組成物Ａ及び組成物Ｂの、受光スリットにおける散乱Ｘ線の移動距離に対する、散乱強度の測定データ（バックグラウンド補正、吸収補正済）を示す。
図‐３及び図‐４に、組成物Ａ及び組成物Ｂのスリット補正後のポイントビームデータを示す。
【００８０】
これら図‐３及び図‐４からＧｕｉｎｉｅｒの式Ｉ＝Ｃ ｅｘｐ（−Ｈ^２Ｒｇ^２／３）（Ｉ：散乱強度、Ｈ：散乱ベクトル（＝２πｓｉｎ２θ／λ）、Ｒｇ：慣性半径、Ｃ：Ｃｏｎｓｔ、 λ：Ｃｕ−Ｋα線波長、２θ：ひろがり角）
に従って慣性半径の最大値を求めると、図‐５及び図‐６に示した様に、組成物Ａについては７．０Å（球形と仮定すると実半径Ｒ＝（５／３）^１／２Ｒｇより、半径９．０Å）、組成物Ｂについては６．０Å（球形と仮定すると半径７．７Å）であった。また、図‐３及び図‐４を逆フーリエ変換し、半径（球形と仮定）の分布を求めた結果を図‐７及び図‐８に示す。半径の最大値は、各々約６Å及び７Åであった。
【００８１】
なお、上記〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマーについて、上記〔微小粒子の確認〕同様の条件下に小角Ｘ線散乱による解析を行った。図−９に散乱強度の測定データを示すが、これにより明らかなように、微小粒子等の構造は認められなかった。
【００８２】
（分子量の測定）
組成物Ａを、以下の条件下、分子量の測定を行った。
脱気装置 ：Ｓｈｏｄｅｘ ＤＥＧＡＳ（昭和電工製）
ポンプ ：Ｓｈｉｍａｄｚｕ ＬＣ６Ａ（島津製作所製）
恒温器 ：西尾工業製
カラム ：Ｔｏｓｏｈ ＴＳＫ−ＧＥＬ ｆｏｒ ＧＰＣ
Ｇ−４０００Ｈ、Ｇ−２０００Ｈ、Ｇ−１０００Ｈ（東洋ソーダ製）
【００８３】
検出器 ：Ｓｈｏｄｅｘ ＲＩ ＳＥ−５１（屈折率検出器）（昭和電工製）
データ採取器：Ｓｈｉｍａｄｚｕ Ｃ−Ｒ３Ａ（島津製作所製）
データ処理 ：パソコン（ＰＣ−９８０１系）
カラム温度 ：４０℃
インジェクション温度：室温
ポンプ温度 ：室温
溶媒 ：テトラヒドロフラン、１．０ｍｌ／分
分子量算出方法 ：標準ポリスチレン換算
結果を以下に示す。
【００８４】
【表１】

この組成物Ａの塩素濃度を測定したところ、１．５ｐｐｍ以下であった。
【００８５】
（反応性官能基の量の測定）
組成物Ａを、密閉し１７日間室温で放置した後、液中のメタノール及びエタノールをガスクロマトグラフィーにより、また液中の水分をカールフィッシャー分析により測定することにより、組成物Ａ中の反応性超微粒シリカの有する反応性官能基の量を算出した。分析条件は、以下の通りである：
【００８６】
ガスクロマトグラフィー分析条件：
インジェクション温度：１８０℃
カラム温度 ：１８０℃
ＴＣＤ（検出器） ：２００℃
キャリアーガス ：Ｈｅ ４０ｍｌ／分
カレント電流 ：１００ｍＡ
充填剤 ：Ｐｏｒａｐａｑ ｔｙｐｅ Ｑ
【００８７】
その結果、液中のメタノール量は１８．８％（０．５８８ｍｏｌ）、エタノール量は５６．７％（１．２３３ｍｏｌ）、水の量は１．２１％（０．０６７２ｍｏｌ）であることから消費された水の量は０．３００８ｍｏｌとなった。したがって、組成物Ａ中の反応性超微粒シリカの有する反応性官能基の量を計算すると、メトキシ基１３．５ｍｏｌ％、エトキシ基４０．８ｍｏｌ％、ヒドロキシル基４５．２ｍｏｌ％となった。
【００８８】
〔コーティング液の調製〕
この熟成物４６．７０ｇに、ヒドロキシ基含有アクリル樹脂５３．３ｇを添加し、１２時間放置しコーティング液を得た。液中不揮発成分は２１．３％であり、膜中ＳｉＯ２濃度は３５％に相当する。
【００８９】
〔コーティング膜の形成〕
このようにして得られたコーティング液を、軟鋼基板上に、２５０μｍアプリケーターで塗工した。次いで電気炉で１５０゜Ｃ、２時間加熱硬化した。得られたコーティング膜厚は１２μｍ、透明であり、鉛筆硬度は２Ｈであった。
【００９０】
実施例２
〔熟成物の調製〕
実施例１〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー２９．７２ｇにエタノール４３．５ｇを添加し、次いでマレイン酸０．３８ｇ及び脱塩素水８．６ｇを添加した。室温で４日放置し熟成し、熟成物を得た。
【００９１】
〔コーティング液の調製〕
上記の熟成物に、下記構造式のシランカップラー（日本ユニカ製 品番Ａ−１８７）を１７．８ｇ添加した後３時間放置し、コーティング液を得た。
【００９２】
ガラス基板を得られたコーティング液に含浸し、引き上げ速度３ｍｍ／秒で引き上げた。次いで電気炉で６０℃、１時間加熱硬化した後２日放置した。得られたコーティング膜の鉛筆硬度９Ｈであった。耐薬品性は５％硫酸を滴下し、一日放置後コーティング塗膜を目視観察したが変化はみられなかった。
またコーティング液は２２週間放置しても粘度変化は見られなかった。
【００９３】
【化１４】

【００９４】
比較例１
実施例１で得られたテトラメトキシシラン・オリゴマー２９．７２ｇに、先ず上記のシランカップラー（日本ユニカ製 品番Ａ−１８７）を１７．８ｇ添加して混合した後エタノール４３．５ｇ、マレイン酸０．３８ｇ及び脱塩素水８．６ｇを添加した。室温で４日放置し熟成しコーティング液とした。実施例２同様の操作により塗膜を形成したが、２日経っても塗膜の鉛筆硬度は５Ｈであった。
【００９５】
実施例３
〔コーティング液の調製〕
実施例１で得られたテトラメトキシシラン・オリゴマー３４．９９ｇにエタノール４９．３１ｇを添加し、次いでマレイン酸０．３８ｇ及び脱塩素水８．３２ｇを添加した。水の添加量はテトラメトキシシラン・オリゴマーを理論上完全に加水分解する量に対し１２７％である。室温で２日放置し熟成し、熟成物を得た。次いで実施例２で用いたシランカップラー（日本ユニカ製 品番Ａ−１８７）を７．００ｇ添加した後２時間放置し、コーティング液を得た。
【００９６】
アルミニウム基材（ＪＩＳ１１００、厚さ０．１ｍｍ）を得られたコーティング液に含浸し、引き上げ速度１０ｍｍ／秒で引き上げた。次いで電気炉で１５０℃、１時間加熱硬化した。得られたコーティング膜厚は３．４μｍ、鉛筆硬度９Ｈ、直径６φｍｍのＳＵＳ３０４棒で１８０℃曲げ加工してもクラック発生はなかった。耐薬品性は５％硫酸を滴下し、一日放置後コーティング塗膜を目視観察したが変化はみられなかった。
またコーティング液は２２週間放置しても粘度変化は見られなかった。
【００９７】
実施例４
実施例１の〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー２９．１５ｇにエタノール５１．２４ｇを添加し、次いでマレイン酸０．３５ｇ及び脱塩素水７．６１ｇ添加した。水添加量はテトラメトキシシラン・オリゴマーの加水分解１００％当量に対し１３９％である。室温で３日放置し熟成した。次いで下記構造式のシランカップラー（信越化学製「ＫＢＭ−５０３」）を１１．６６ｇ添加した後２時間放置し、コーティング液を得た。
【００９８】
アルミニウム基材（ＪＩＳ１１００、厚さ０．１ｍｍ）を得られたコーティング液に含浸し、引き上げ速度１０ｍｍ／秒で引き上げた。次いで電気炉で１５０℃、１時間加熱硬化した。得られたコーティング膜厚は２．６μｍ、鉛筆硬度９Ｈ、直径６φｍｍのＳＵＳ３０４棒で１８０℃曲げ加工してもクラック発生はなかった。耐薬品性は５％硫酸を滴下し、一日放置後コーティング塗膜を目視観察したが変化はみられなかった。
またコーティング液は２６週間放置しても粘度変化は見られなかった。
【００９９】
【化１５】

【０１００】
実施例５
実施例１で得られたテトラメトキシシラン・オリゴマー２３．５７ｇにエタノール５５．３４ｇを添加し、次いでマレイン酸０．３５ｇ及び脱塩素水６．６１ｇ添加した。水添加量はテトラメトキシシラン・オリゴマーの加水分解１００％当量に対し１５０％である。室温で２日放置し熟成した。次いで下記構造式のシランカップラー（信越化学製「ＫＢＭ−１００３」）を１４．１４ｇ添加した後２時間放置し、コーティング液を得た。
【０１０１】
アルミニウム基材（ＪＩＳ１１００、厚さ０．１ｍｍ）を得られたコーティング液に含浸し、引き上げ速度２０ｍｍ／分で引き上げた。次いで電気炉で１５０℃、１時間加熱硬化した。得られたコーティング膜厚は２．１μｍ、鉛筆硬度９Ｈ、直径６φｍｍのＳＵＳ３０４棒で１８０℃曲げ加工してもクラック発生はなかった。耐薬品性は５％硫酸を滴下し、一日放置後コーティング塗膜を目視観察したが変化はみられなかった。
またコーティング液は４０週間放置しても粘度変化は見られなかった。
【０１０２】
【化１６】
ＣＨ_２ ＝ＣＨＳｉ（ＯＣＨ_３ ）_３
【０１０３】
実施例６
実施例１のテトラメトキシシラン・オリゴマーの合成で得られたテトラメトキシシラン・オリゴマー１００重量部に対し、０．３２重量％のマレイン酸水（ｐＨ１．８）２０重量部を添加して、室温で３０分間撹拌し均一透明な熟成物を得た。次いでエポキシ系シランカップラー（日本ユニカー製 Ａ−１８７）６０重量部を添加し室温で３０分間撹拌した。引続き、脱塩水１８０重量部を添加し室温で３０分間撹拌した。得られたコーティング液のｐＨは３．０であった。
【０１０４】
アルミニウム基材（ＪＩＳ１１００、厚さ０．１ｍｍ）を得られたコーティング液に含浸し、引上げ速度５ｍｍ／秒で引き上げた。この塗布基材を室温で５分間放置したのち、電気炉で１５０℃、１時間加熱硬化した。得られたコーティング膜の膜厚は３．２μｍ、鉛筆硬度９Ｈ、直径６φｍｍのＳＵＳ３０６棒で１８０°曲げ加工してもクラック発生はなかった。耐薬品性は５％硫酸を滴下し、一日放置後コーティング塗膜を目視観察したが変化はみられなかった。
【０１０５】
実施例７
エポキシ系カップラーに代えてビニル系シランカップラー（信越化学製 ＫＢＭ−１００３）６０重量部を用いた以外は実施例４と同様の操作を行いコーティング液を得、同様の操作によりコーティング膜を得た。得られたコーティング膜の膜厚は１．９μｍ、鉛筆硬度は９Ｈ、直径６φｍｍのＳＵＳ棒で１８０°曲げ加工してもクラック発生はなかった。耐薬品性は５％硫酸を滴下し、一日放置後コーティング塗膜を目視観察したが変化はみられなかった。
【０１０６】
実施例８
実施例１の〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー１００重量部に対し、１重量％のマレイン酸水（ｐＨ１．５）６０重量部を添加して、室温で５分間撹拌し透明な加水分解液を得た。次いで脱塩水２００００重量部を添加した。引き続きエポキシ系シランカップラー（日本コニカー（株）製 品番Ａ−１８７）を３０重量部添加し室温で１時間、撹拌した。得られたコーティング液のｐＨは３．７であった。
【０１０７】
このコーティング液２５００重量部に水酸化アルミニウム粉１０００ｇ（アルコア化成（株）製 品番ＯＣ−２０００ 平均粒径４７μｍ）に添加しヘンシェルミキサーで１５００ｒｐｍで２０分撹拌した。その後ヘンシェルミキサーのジャケットに１１０℃の水蒸気を通し、１００℃以上にヘンシェルミキサー内部を加熱し、撹拌もしながら３０分加熱しコーティングされた水酸化アルミニウム粉を得た。
【０１０８】
実施例９
実施例１の〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー１００重量部に対し、１重量％のマレイン酸水（ｐＨ１．５）６０重量部を添加して、室温で５分間撹拌し透明な加水分解液を得た。次いでビニル系シランカップラー（信越化学製 ＫＢＭ−１００３）を４３重量部を添加し室温で１時間撹拌した。次に脱塩水１４０００重量部を添加した。得られたコーティング液のｐＨは３．３であった。
【０１０９】
このコーティング液２５００重量部に水酸化アルミニウム粉１０００ｇ（アルコア化成（株）製 品番Ｃ−３８５ 平均粒径８μｍ）に添加しヘンシェルミキサーで１５００ｒｐｍで２０分撹拌した。その後ヘンシェルミキサーのジャケットに１１０℃の水蒸気を通し、１００℃以上にヘンシェルミキサー内部を加熱し、撹拌もしながら３０分加熱しコーティングされた水酸化アルミニウム粉を得た。
【０１１０】
実施例１０
実施例４で得られたコーティング液２０重量部を、アセトン５０重量部で希釈した液を水酸化アルミニウム粉１０００ｇ（アルコア化成 Ｃ−３８５）に添加しヘンシェルミキサーで室温下、５００ｒｐｍで２０分撹拌した。その後ヘンシェルミキサーのジャケットに１１０℃水蒸気を通し１００℃以上にヘンシェルミキサー内部を加熱し、撹拌しながら３０分加熱しコーティングされた水酸化アルミニウムを得た。
【０１１１】
実施例１１
実施例４で得られたコーティング液に代えて、実施例５で得られたコーティング液２０重量部を用いた以外は実施例１０同様の操作を行い、コーティングされた水酸化アルミニウムを得た。
【０１１２】
実施例１２
〔熟成物の調製〕
実施例１〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー３０．７７ｇに水６．５２ｇ、アルミニウムトリスアセチルアセトネート０．３１ｇ、溶媒として「ソルミックスＡ−１１」（日本化成品株式会社品、エタノール８５．５％、ＩＰＡ１．１％）６２．４ｇを添加した。水の量はテトラメトキシシラン・オリゴマーを理論上完全に加水分解縮合可能な量に対し１１３％である。室温で１日間放置し無色透明な均一液状の熟成物を得た。
【０１１３】
〔反応性官能基の量の測定〕
こうして得られた熟成物を、密閉し１７日間室温で放置した後、実施例１（反応性官能基の量の測定）におけると同様の分析条件、分析方法により熟成物中の反応性超微粒シリカの有する反応性官能基の量を算出した。
【０１１４】
その結果、液中のメタノール量は１８．９％（０．５９１ｍｏｌ）、エタノール量は５７．１％（１．２４１ｍｏｌ）、水の量は１．１５％（０．０６３９ｍｏｌ）であることから消費された水の量は０．３０４１ｍｏｌとなった。したがって、熟成物中の反応性超微粒シリカの有する反応性官能基の量を計算すると、メトキシ基１３．２ｍｏｌ％、エトキシ基４０．３ｍｏｌ％、ヒドロキシル基４６．０ｍｏｌ％となった。
【０１１５】
〔コーティング液の調製〕
この熟成物４６．７０ｇに、ヒドロキシ基含有アクリル樹脂５３．３ｇを添加し、１２時間放置しコーティング液を得た。液中不揮発成分は２１．３％であり、膜中ＳｉＯ２濃度は３５％に相当する。
【０１１６】
〔コーティング膜の形成〕
このようにして得られたコーティング液を、軟鋼基板上に、２５０μｍアプリケーターで塗工した。次いで電気炉で１５０゜Ｃ、２時間加熱硬化した。得られたコーティング膜厚は１１μｍ、透明であり、鉛筆硬度はＨであった。
【０１１７】
比較例２
〔コーティング液の調製〕
実施例１〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー１４．３ｇに水１．０７ｇ、アルミニウムトリスアセチルアセトネート０．２８ｇ、「ソルミックスＡ−１１」３１．１５ｇ、及びヒドロキシ基含有アクリル樹脂５３．２ｇを添加し１２時間放置しコーティング液とした。液中不揮発成分は２１．３％であり、膜中ＳｉＯ２濃度は３５％に相当する。
【０１１８】
〔コーティング膜の形成〕
このようにして得られたコーティング液を、軟鋼基板上に、実施例１０同様の操作により塗工し、同様に加熱硬化した。得られたコーティング膜厚は７〜８μｍ、透明であり、鉛筆硬度は５Ｂ以下であった。また、塗膜表面には、べたつきがみられた。
【０１１９】
実施例１３
〔コーティング液の調製〕
実施例１２〔コーティング液の調製〕で得られた熟成物４３．８８ｇに、ヒドロキシ基含有ポリエステル樹脂５６．１２ｇを添加し、１２時間放置しコーティング液を得た。液中不揮発成分は３５％であり、膜中ＳｉＯ２濃度は２０％に相当する。
【０１２０】
〔コーティング膜の形成〕
このようにして得られたコーティング液を、軟鋼基板上に、実施例１０同様の塗工、加熱硬化を行った。得られたコーティング膜厚は３５μｍ、透明であり、鉛筆硬度は５Ｈであった。
【０１２１】
〔密着強度の測定〕
上記のコーティング液を、調液から７日後に、ガラス入りエポキシ樹脂基板に５００μｍアプリケーターを用いて塗布し、電気炉で１５０℃、１時間加熱し硬化した。得られた透明膜の接着強度は１２ｋｇ／ｃｍ^２であった。ガラス入りエポキシ基板に代えてセラミック製基板を用い同様の操作で得られた透明膜の接着強度は５０ｋｇ／ｃｍ^２と、非常に密着性に優れていた。
【０１２２】
〔耐沸騰水性、耐アルカリ性の測定〕
上記〔コーティング膜の形成〕で得られた塗膜を基板ごと沸騰水に入れ、３時間加熱したが、変化は見られなかった。また塗膜に５％ＮａＯＨを滴下し１５時間放置したが、僅かな白化が見られたのみであった。
【０１２３】
比較例３
〔コーティング液の調製〕
実施例１〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー１３．１７ｇに水０．９９ｇ、アルミニウムトリスアセチルアセトネート０．８１ｇ、メチルエチルケトン２６．６０ｇ、イソプロパノール４．４２ｇ及びヒドロキシ基含有ポリエステル樹脂５４．８ｇを添加し１２時間放置しコーティング液とした。。液中不揮発成分は３４．２％であり、膜中ＳｉＯ２濃度は２０％に相当する。
【０１２４】
〔コーティング膜の形成〕
このようにして得られたコーティング液を、軟鋼基板上に、１５０μｍアプリケーターを使用した以外は実施例１２同様の操作により塗工し、同様に加熱硬化した。得られたコーティング膜厚は１５μｍであり、鉛筆硬度はＦであった。
【０１２５】
〔耐沸騰水性、耐アルカリ性の測定〕
上記〔コーティング膜の形成〕で得られた塗膜を基板ごと沸騰水に入れ、３時間加熱したところ、塗膜表面に白化、肌荒れが生じた。また塗膜に５％ＮａＯＨを滴下し１５時間放置したところ、塗膜が溶解して消失した。
【０１２６】
実施例１４
〔コーティング液の調製〕
実施例１２〔コーティング液の調製〕で得られた熟成物６４．９４ｇに、シリル基含有アクリル樹脂３５．０６ｇを添加し、１週間放置しコーティング液を得た。液中不揮発成分は２９．７％であり、膜中ＳｉＯ２濃度は３５％に相当する。
【０１２７】
〔コーティング膜の形成〕
このようにして得られたコーティング液を、軟鋼基板上に、実施例１０同様の塗工、加熱硬化を行った。得られたコーティング膜厚は２７μｍ、透明であり、鉛筆硬度は４Ｈであった。
【０１２８】
〔常温乾燥によるコーティング膜の形成〕
上記のコーティング液を、軟鋼基板上に、５０μｍアプリケーターを用いて塗布した。２０℃の室内に、１週間放置した。得られたコーティング膜は膜厚５μｍで、透明であり鉛筆硬度２Ｈ以上であった。
【０１２９】
比較例４
〔コーティング液の調製〕
実施例１〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー２５．９５ｇに水１．９４ｇ、アルミニウムアセチルアセテート０．５１ｇ、、イソプロパノール２５．７１ｇ及びシリル基含有アクリル樹脂４５．９０ｇを添加し１２時間放置しコーティング液とした。。液中不揮発成分は３８．７％であり、膜中ＳｉＯ２濃度は３５％に相当する。
【０１３０】
〔コーティング膜の形成〕
このようにして得られたコーティング液を、軟鋼基板上に、実施例１２同様の操作により塗工し、同様に加熱硬化した。得られたコーティング膜厚は４５μｍであり、鉛筆硬度はＨに下がった。
【０１３１】
実施例１５
〔コーティング液の調製〕
実施例１２〔コーティング液の調製〕で得られた熟成物４６．７ｇに、１，４−ブタンジオール１３．９ｇ、「ソルミックスＡ−１１」３９．５ｇを添加し、１２時間放置しコーティング液を得た。液中不揮発成分は２１．３％であり、膜中ＳｉＯ２濃度は３５％に相当する。
【０１３２】
〔コーティング膜の形成〕
このようにして得られたコーティング液を、軟鋼基板上に、１５０μｍアプリケーターで塗工した。次いで電気炉で１５０゜Ｃ、２時間加熱硬化した。得られたコーティング膜厚は８μｍ、透明であり、鉛筆硬度は７Ｈであった。
【０１３３】
比較例５
〔コーティング液の調製〕
実施例１〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー１４．３ｇに水１．０８ｇ、アルミニウムトリスアセチルアセトネート０．２１ｇ、１，４−ブタンジオール１３．８ｇ、及び「ソルミックスＡ−１１」７０．５ｇを添加し１２時間放置しコーティング液とした。。液中不揮発成分は２１．３％であり、膜中ＳｉＯ２濃度は３５％に相当する。
【０１３４】
〔コーティング膜の形成〕
このようにして得られたコーティング液を、軟鋼基板上に、１５０μｍアプリケーターで塗工した以外は実施例１０同様の操作により塗工し、同様に加熱硬化した。得られたコーティング膜厚は８μｍであり、鉛筆硬度は５Ｈに低下した。また、塗膜表面は、むら、剥離が一部に見られた。
【０１３５】
実施例１６〜１９
実施例１〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー３０．７７ｇに脱塩素水６．５２ｇ、「ソルミックスＡ−１１」６２．５ｇ、３５％塩酸０．０８ｇを添加した。水添加量はテトラメトキシシランに対し加水分解１００％当量に対し１１３％である。室温で１日放置することにより熟成し、熟成物を得た。この熟成物を用いた以外は実施例１２〜１５と同様にして、コーティング液とした。
これらのコーティング液を用いた以外は実施例１２〜１５と同様にして、塗膜を形成した。得られた塗膜の物性を、表−１に示す。
【０１３６】
【表２】

【０１３７】
実施例２０〜２３
実施例１〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー３０．７７ｇに脱塩素水６．５２ｇ、「ソルミックスＡ−１１」６２．５ｇ、及び実施例１４と同当量の硝酸を添加した。水添加量はテトラメトキシシランに対し加水分解１００％当量に対し１１３％である。室温で１日放置することにより熟成し、熟成物を得た。この熟成物を用いた以外は実施例１２〜１５と同様にして、コーティング液とした。
これらのコーティング液を用いた以外は実施例１２〜１５と同様にして、塗膜を形成した。得られた塗膜の物性を、表−２に示す。
【０１３８】
【表３】

【０１３９】
比較例６
実施例１〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマー２９．１５ｇにエチルアルコール５９．３０ｇを配合し、次いで硬化触媒マレイン酸０．３５ｇ及び脱塩素水６．１６ｇを添加した。水添加量はテトラメトキシシラン・オリゴマーの加水分解１００％当量に対し１１３％である。室温で２日放置し熟成し、コーティング液を得た。
アルミニウム基材（ＪＩＳ１１００、厚さ０．１ｍｍ）を得られたコーティング液に含浸し、引き上げ速度３ｍｍ／分で引き上げた。次いで電気炉で１５０℃、１時間加熱硬化した。得られたコーティング膜厚は０．４μｍで、基板から剥離した。
【０１４０】
比較例７
シランカップラーを始めからテトラメトキシシラン・オリゴマーに配合する以外は実施例２と同様にコーティング液を作成し、造膜した。
コーティング膜の鉛筆硬度は５Ｈと低下した。
【０１４１】
実施例２４〜２６、比較例８〜１１
水の量を替えた以外は実施例１０と同様にして、コーティング液を得た。これらと実施例２のコーティング液を用い、１５０μｍアプリケーターを用いた以外は実施例２と同様にして塗膜を得た。得られた塗膜の物性を表−３に示す。
【０１４２】
【表４】

【０１４３】
実施例２７
金属ケイ素とメタノールの反応により得られたテトラメトキシシラン４０．５１ｇ及び水１０．８３ｇを配合し、１日間放置し熟成して得られた熟成物を用いた以外は実施例１２と同様の操作により塗膜を形成した。得られたコーティング膜厚は１２μｍ、透明であり、鉛筆硬度はＨであった。
。
【０１４４】
実施例２８〜３２
実施例１２で得られた熟成物を用い、表−４の通りシランカップラー及び水を配合し、室温で３時間熟成し、塗膜を形成した。塗膜の形成方法、硬化条件は表−４の通りである。得られた塗膜の物性を表−４に示す。
【０１４５】
【表５】

【０１４６】
〔耐汚染性の評価方法〕
（キシレンラビング）
綿布にキシレンを含浸し、力を入れて強く塗膜の表面を１００回往復させた。塗膜が溶出してしまったものを××印、無数のキズを生じたものを×印、殆どキズの見られないものを〇印とした。
（耐沸騰水性）
塗膜を基材ごと沸騰水に浸漬し３時間煮沸した。変化が見られないものを〇印とした。
【０１４７】
（耐酸性試験）
塗膜に５％硫酸を滴下し１５時間放置した。変化の見られないものを〇印とした。
（密着性試験）
密着性は、碁盤目テストで行った。
【０１４８】
比較例１２
実施例１で得られたテトラメトキシシラン・オリゴマーの代わりに市販のエチルシリケート（日本コルコート社製ＥＳ４０）３９．７ｇを用い、Ａ−１１の量を５３．５ｇとした以外は実施例１２同様の方法により熟成した。こうして得られた熟成物を用いた以外は実施例３０と同様にして得られた塗膜は、鉛筆硬度が４Ｈと、実施例３０と比較して大幅に低下した。
【発明の効果】
本発明により、各種の基板、粉粒体、線状物等の基材に適用でき、耐汚染性、耐熱性、耐擦傷性、耐候性等優れた特性を有し、高硬度かつ曲げ加工性に優れたクラック発生のない膜厚の厚いコーティング膜を得ることができる。また、各種粉体表面をガラス質膜でコーティングし、かつ各種シランカップラーを併用することが可能であることからＦＲＰ、人造大理石等の種々マトリックスとフィラーとの密着性向上に顕著な効果を発現できる。
【図面の簡単な説明】
【図１】組成物Ａの散乱強度の測定データ
【図２】組成物Ｂの散乱強度の測定データ
【図３】組成物Ａのスリット補正後のポイントビームデータ
【図４】組成物Ｂのスリット補正後のポイントビームデータ
【図５】組成物Ａ中の微小粒子の慣性半径の分布
【図６】組成物Ｂ中の微小粒子の慣性半径の分布
【図７】組成物Ａ中の微小粒子の球仮定半径の分布
【図８】組成物Ｂの微小粒子の球仮定半径の分布
【図９】実施例１〔テトラメトキシシラン・オリゴマーの合成〕で得られたテトラメトキシシラン・オリゴマーの散乱強度の測定データ[0001]
[Industrial application fields]
The present invention relates to a coating liquid and a method for producing the same, and a coating film, and more particularly, natural and synthetic silica, iron, stainless steel, aluminum and other metals, plastic, glass, wood, cement and other products, and hydroxylation. Scratch resistance, transparency, heat resistance, weather resistance, adhesion, etc. applied to the surface of powders such as aluminum, calcium silicate, calcium carbonate, magnetic powder, metal powder, glass fiber, metal wire, etc. The present invention relates to an excellent coating solution and a method for producing the same.
[0002]
Although organic materials such as lacquer are extremely excellent in aesthetics, they are accompanied by difficulties such as being flexible and easily damaged, and requiring repeated coating that requires labor to form a coating film.
[0003]
In recent years, attempts have been made to develop the high hardness characteristic of inorganic materials by adding inorganic elements to organic materials. For example, silicon such as “Lumiflon” (trademark: Asahi Glass Co., Ltd.) obtained by polymerizing fluorine-containing monomers, or “Zemlac” (trademark: Kaneka Chemical Industry Co., Ltd.) polymerized with silicon-containing monomers There are resins.
[0004]
However, it is said that the fluorine resin is still flexible and easily damaged, and is accompanied by a new difficulty that it easily absorbs oil and easily becomes dirty. For silicon resins, the hardness increases, but the silicon content is 10% by weight (SiO 2₂As a result, there is no actual product that has a content of 10% by weight or more.
[0005]
Thus, in the past, inorganic elements were introduced into organic compounds at the stage of molecular design. However, as long as inorganic elements are introduced into organic monomers, there is a limit to the content of inorganic elements. That is, the number of inorganic elements that can be introduced into the specified organic compound is limited.
On the other hand, an inorganic material has been developed to protect work materials and structures from the natural environment to maintain aesthetics and extend the service life. For example, this is a technique for coating a metal surface with “amorphous substance mainly composed of silicon / oxygen having a polysiloxane bond”. Cloisonne is a material in which a raw material powder mainly composed of silica sand is applied to the surface of a metal such as copper and then fired and dissolved to form an inorganic amorphous film.
[0006]
The advantages of the above-described “amorphous substance mainly composed of silicon / oxygen having a polysiloxane bond” are extremely high aesthetic retention, weather resistance, scratch resistance, and acid resistance. However, it also has drawbacks. It is highly fragile (brittle and fragile).
[0007]
[Problems to be solved by the invention]
Therefore, the present inventors have utilized an amorphous polysiloxane bond such as the aforementioned Cloisonne ware in introducing silicon into an organic compound, and at the same time, solved the above-mentioned difficulties of the above-mentioned resin and cloisonne ware. A new coating composition using tetramethoxysilane, which has already been improved in hardness, solvent resistance, chemical resistance, stain resistance, scratch resistance, etc. (Japanese Patent Application No. 5-204229, Japanese Patent Application No. 5-80764, Japanese Patent Application No. 5-101116, Japanese Patent Application No. 5-296772, Japanese Patent Application No. 5-296773, etc.).
[0008]
However, the coating films obtained with these coating solutions have high hardness, solvent resistance, and chemical resistance, but the resulting coating film is thin, and the film thickness is too thick due to lack of flexibility. As a result, further improvements have been desired, such as the occurrence of cracks during processing and problems in adhesion to metal materials. Also, when used for coating inorganic powders, it is effective in improving fluidity, but has insufficient bonding strength with organic matrix such as artificial marble, and has insufficient strength, water resistance and heat resistance. There was a case.
[0009]
[Means for Solving the Problems]
Therefore, the present inventors have made extensive studies in view of the above problems, and as a result, tetramethoxysilane.And its oligomersIn addition, after advancing the hydrolysis and condensation reaction sufficiently by adding more water than the theoretically 100% hydrolyzable and condensing amount, it is condensed with the tetramethoxysilane hydrolyzed condensate thus obtained. The composition obtained by blending the components to be obtained should be a coating film that is transparent and has a high thickness, a thickness of several μm to several tens of μm while maintaining high hardness, solvent resistance, and chemical resistance, and excellent flexibility. At the same time, the present inventors have found that the adhesion to various base materials is improved and reached the present invention.
[0010]
That is, the present invention relates to tetramethoxysilane.Or its oligomerThis was obtained by aging and adding water in an amount that could theoretically be 100% hydrolytically condensed.This is a fine hydrolysis condensate with an inertia radius of 10 mm or less.A reactive organic compound having two or more functional groups capable of undergoing a condensation reaction with the hydrolysis condensateGives a transparent coatingFormed by coating liquid and such coating liquidWasCoating film.
Hereinafter, the present invention will be described in detail.
[0011]
First, tetramethoxysilane used in the present invention is a monomer (Si (OCH) obtained by a method such as a reaction between silicon tetrachloride and methanol, or a reaction between metal silicon and methanol._Three)_FourRepresented by
And / or oligomers which are partial hydrolysis condensates of these monomers can be used, but impurities can be easily removed by refining the raw materials, and hydrochloric acid is not a by-product, and there is a problem of equipment corrosion. Since it does not occur, it is desirable to use a tetramethoxysilane monomer and / or its oligomer obtained by reacting silicon and methanol, particularly for applications where impurities need to be removed.Hereinafter, in this specification, tetramethoxysilane monomers and oligomers may be collectively referred to as tetramethoxysilane.
[0012]
It has been suggested that the tetramethoxysilane monomer itself is highly toxic, such as eroding the cornea of the eye and causing damage even with vapor. Moreover, since activity is high, it may generate | occur | produce and bump at the time of work. Furthermore, the coating liquid containing a large amount of monomer tends to gradually change its performance due to the reaction of the monomer during storage.
In this regard, by using an oligomer of tetramethoxysilane (hereinafter referred to as “tetramethoxysilane oligomer”), it is possible to cope with these, express excellent coating properties over a long period of time, and reduce toxicity. Moreover, the coating liquid excellent also in workability | operativity can be provided.
[0013]
The partial hydrolysis-condensation reaction itself for obtaining the tetramethoxysilane oligomer can be performed by a known method. For example, a predetermined amount of water is added to the above tetramethoxysilane monomer, and a by-product is formed in the presence of an acid catalyst. The reaction is usually carried out at about room temperature to 100 ° C. while distilling off the alcohol. Methoxysilane is hydrolyzed by this reaction, and a liquid tetramethoxysilane oligomer (generally having an average degree of polymerization of about 2 to 8, most of which is 3 to 7) having two or more hydroxyl groups by a condensation reaction is partially hydrolyzed condensate. As obtained. The degree of hydrolysis can be appropriately adjusted depending on the amount of water used. The theoretical amount of water necessary for hydrolytic condensation of all hydrolyzable groups of tetramethoxysilane, that is, the number of moles of methoxy groups. Expressed as a percentage of the actual amount of water added to 1/2 mole of water. In the present invention, the degree of hydrolysis of tetramethoxysilane is usually selected from about 20 to 80%, preferably about 30 to 60%. If it is 20% or less, the residual monomer ratio is high and the productivity is low. Further, if it is 80% or more, the resulting tetramethoxysilane oligomer is easily gelled.
[0014]
The tetramethoxysilane oligomer thus obtained usually contains about 2 to 10% of monomer. If this monomer is contained, the storage stability of the coating liquid may be lacking. Therefore, the monomer may be removed so that the monomer content is 1% by weight or less, preferably 0.3% by weight or less. This monomer removal can be performed by flash distillation, vacuum distillation, or inert gas blowing.
[0015]
In the present invention, the above tetramethoxysilane is added with water in an amount capable of theoretically 100% hydrolytic condensation (hereinafter referred to as “hydrolysis 100% equivalent”). That is, the amount of water that is theoretically necessary for hydrolyzing and condensing all hydrolyzable groups of tetramethoxysilane, that is, methoxy groups. The same applies to the case of using tetramethoxysilane oligomer. Add more water than theoretically required to hydrolyze and condense the remaining methoxy groups, that is, add more than half the number of moles of the remaining methoxy groups. To do.
[0016]
Thus, any amount may be used as long as the hydrolysis is 100% equivalent or more, but when an organic solvent such as methanol or ethanol is used as a diluent to be described later, it is practically 1 to 4 times the hydrolysis 100% equivalent. More preferably, it is 1 to 2 times, particularly preferably 1 to 1.5 times. If the amount of water exceeds 4 times the 100% equivalent of hydrolysis, the storage stability of the coating solution may be lowered in some cases. On the other hand, when the hydrolysis is less than 100% equivalent, the physical properties of the coating film such as hardness when coated are not sufficient.
[0017]
There is no particular limitation on the water used in the present invention, and tap water may be used. However, depending on the purpose and application, it may be desirable to use dechlorinated water or ultrapure water. For example, base materials such as mild steel, copper, and aluminum that are particularly susceptible to corrosion by acids, electronic base materials such as barrier coatings such as heat-resistant coatings, moisture-resistant coatings, and chemical-resistant coatings, and dechlorinated water when used for applications such as electrical insulating coatings Or when it is not desirable to mix impurities, such as for semiconductor applications, ultrapure water can be used.
[0018]
In the present invention, a diluent can be further added. By adding a diluent, the storage stability of the resulting coating liquid is improved.
As the diluent, water or an organic solvent can be used depending on the purpose.
As an organic solvent that can be used as a diluent, one or more of alcohols, glycol derivatives, hydrocarbons, esters, ketones, ethers and the like are mixed and used.
[0019]
Alcohol includes methanol, ethanol, isopropyl alcohol, n-butanol, isobutanol, octanol, n-propyl alcohol, acetylacetone alcohol, and the like, and glycol derivatives include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n -Propyl ether, ethylene glycol mono n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate , Propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate.
[0020]
As the hydrocarbons, benzene, kerosene, toluene, xylene and the like can be used, and as the esters, methyl acetate, ethyl acetate, butyl acetate, methyl acetoacetate, ethyl acetoacetate and the like can be used. Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetyl acetone, and ethers such as ethyl ether, butyl ether, 2-α-methoxyethanol, 2-α-ethoxyethanol, dioxane, furan, and tetrahydrofuran can be used.
[0021]
Of these solvents, alcohols, especially C₁  ~ C₄  Methanol, ethanol, isopropanol or butanol are preferred because they are easy to handle, have good storage stability in liquids, and are excellent in the properties of the resulting coating film. Furthermore, by using methanol or ethanol among these, it can be set as the coating liquid which can obtain an extremely high-hardness coating film easily.
[0022]
Moreover, when using organic solvents, such as alcohol, as a diluent, the compounding quantity of a solvent is 50-5000 weight part with respect to 100 weight part of tetramethoxysilane oligomer, Preferably it is 100-1000 weight part, More preferably, it is 100-500 weight. Good part. If it is 50 parts by weight or less, the storage stability of the coating liquid is lowered and gelation tends to occur. If it exceeds 5000 parts by weight, the coating thickness becomes extremely thin.
[0023]
When water is used as the diluent, the amount of added water described above may be increased and diluted, or the obtained coating solution may be diluted with an arbitrary amount of water. A suitable amount of water to be added is, for example, 24 to 300 parts by weight in total with 100% equivalent of water described above for 100 parts by weight of tetramethoxysilane. When water is used as the diluent, gelation of the liquid is more likely to occur than when an organic solvent such as methanol or ethanol is used. Therefore, the gelation is prevented by maintaining the pH at 3 or less, preferably at pH 1-2. Therefore, in order to maintain the above pH, the type and amount of catalyst used are appropriately selected according to the amount of diluted water.
[0024]
In the present invention, a curing catalyst can be added as necessary.
Examples of the catalyst include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid, acetic acid, formic acid, p-toluenesulfonic acid, benzoic acid, phthalic acid, maleic acid, propionic acid, oxalic acid and other organic acids, potassium hydroxide , Alkali catalysts such as sodium hydroxide, calcium hydroxide, ammonia, organic metals, metal alkoxides, organic tin compounds such as dibutyltin dilaurate, dibutyltin dioctiate, dibutyltin diacetate, aluminum tris (acetylacetonate), titanium Tetrakis (acetylacetonate), Titanium bis (butoxy) bis (acetylacetonate), Titanium bis (isopropoxy) bis (acetylacetonate), Zirconium tetrakis (acetylacetonate), Zirconium bis (butoxy) bis There are metal chelate compounds such as acetylacetonate) and zirconium bis (isopropoxy) bis (acetylacetonate), and boron compounds such as boron butoxide and boric acid, but the storage stability of the coating liquid and the hardness of the resulting coating film From the viewpoint of excellent properties such as flexibility and prevention of corrosion on the substrate to be treated, one or more of acetic acid, maleic acid, oxalic acid, fumaric acid, and metal alkoxide or Two or more kinds should be used.
[0025]
Desirable catalyst types can be appropriately selected depending on the diluent to be used, the type of substrate to be coated, and the application.
For example, when a strong acid such as hydrochloric acid or nitric acid is used as a catalyst, the solution has good storage stability, the time required for aging described below can be shortened, and the hardness of the coating film obtained by coating is excellent. However, it may be better to avoid a substrate that is particularly susceptible to corrosion. On the other hand, for example, maleic acid is desirable because it has less erosion such as corrosion, requires a relatively short aging time, and has particularly excellent properties such as hardness of the resulting coating film and storage stability in liquid.
[0026]
In addition, when methanol or ethanol is used as a diluent, in addition to the above-described acid catalyst, for example, aluminum tris (acetylacetonate), titanium tetrakis (acetylacetonate), titanium bis (butoxy) bis (acetylacetonate), Metal acetylacetonates such as titanium bis (isopropoxy) bis (acetylacetonate), zirconium tetrakis (acetylacetonate), zirconium bis (butoxy) bis (acetylacetonate) and zirconium bis (isopropoxy) bis (acetylacetonate) Even when an nate compound or the like is used, a coating film having sufficient hardness can be obtained without impairing the storage stability in the liquid.
[0027]
The amount of the catalyst component added is not particularly limited as long as it can function as a catalyst, but is usually in the range of about 0.1 to 10 parts by weight with respect to 100 parts by weight of tetramethoxysilane. And preferably 0.5 to 5 parts by weight.
[0028]
The blending method of these components is not particularly limited, and for example, a more uniform blend can be obtained by means such as using a catalyst component previously dissolved in water or blending with stirring. In addition, when using the catalyst which is easily decomposed | disassembled with water and another solvent, this is mix | blended with tetramethoxysilane, and it is preferable to mix | blend with water and another solvent at the time of use. Furthermore, the catalyst component can be added to other components when used.
[0029]
In the present invention, a blended liquid obtained by blending these components (hereinafter referred to as “blended liquid”) is aged.
Through this aging step, the partial cross-linking reaction by the hydrolysis and condensation of tetramethoxysilane proceeds sufficiently, and the microparticles described later are formed, so the properties of the resulting coating film are considered to be excellent. It is done.
[0030]
The ripening of the blended solution may be allowed to stand, but may be stirred. The standing time is a time sufficient for the above-mentioned partial cross-linking reaction to proceed to a sufficient extent to obtain desired film characteristics, and also depends on the type of diluent used and the type of catalyst. For example, when methanol and / or ethanol is used as a diluent, about 1 hour or more at room temperature with hydrochloric acid, several hours or more with maleic acid, preferably about 8 hours to 2 days is sufficient.
[0031]
In addition, when water is used as a diluent, the pH is 3 or less, preferably 1 to 2, and the hydrolysis and condensation is allowed to proceed while stirring for about 1 to 180 minutes, usually about 10 to 20 minutes. You can get things. After obtaining a transparent liquid in this way, it is desirable to let it stand for another 1 to 2 hours to allow ripening to proceed.
[0032]
The time required for aging is also affected by the ambient temperature, and it may be better to take measures such as heating to around 20 ° C. in extremely cold regions. In general, ripening proceeds rapidly at high temperatures, but when heated to 100 ° C. or higher, gelation occurs. Therefore, heating to 50 to 60 ° C. is appropriate at most. In some cases, aging may be performed under reflux.
[0033]
By sufficiently aging, whitening and peeling of the resulting film can be prevented. In general, aging is sufficient if it is allowed to cool to room temperature after the heat generation due to hydrolysis is completed, and is allowed to stand for a time sufficient for the partial crosslinking reaction to end. In the blended liquid of the present invention that has undergone such aging (hereinafter referred to as “aged product”), fine particles (hereinafter referred to as “reactive ultrafine silica” composed of tetramethoxysilane hydrolyzed condensate having an inertia radius of 10 mm or less are contained. Can be easily confirmed by means such as small-angle X-ray scattering. That is, due to the presence of fine particles, the diffraction intensity distribution of incident X-rays shows diffuse scattering called center scattering in the incident ray direction, that is, small-angle X-ray scattering. The scattering intensity I is given by the following Guinier equation.
[0034]
I = C exp (−H²Rg²/ 3) (I: scattering intensity, H: scattering vector (= 2πsin 2θ / λ), Rg: radius of inertia of fine particles, C: Const, λ: incident X-ray wavelength, 2θ: spread angle)
[0035]
Taking the common logarithm of both sides of the above Guinier equation,
log I = log C− (H²Rg²Therefore, when there are microparticles, the radius of inertia of the microparticles can be determined by measuring the scattering intensity, plotting a log-log graph against the scattering vector, and determining the slope.
[0036]
In measuring the inertial radius, a measurement error may occur somewhat depending on the concentration of the liquid to be measured. The reactive ultrafine silica of the present invention has an inertia radius of 10 mm or less when measured as a liquid having a silica equivalent concentration of 4.3% for the sake of accuracy. In particular, when hydrolysis is carried out by adding 100% equivalent or more of water in the presence of an organic solvent such as ethanol as a diluent, the resulting reactive ultrafine silica has an inertia radius of 6 mm depending on the above measurement conditions. The following can be made extremely minute and can exist stably.
[0037]
The reactive ultrafine silica of the present invention has a weight average molecular weight measured by GPC of about 1000 to 3000 in terms of standard polystyrene. Moreover, many of these have a weight average molecular weight of about 1300 to 2000. Although the molecular weight of the reactive ultrafine silica obtained depends on the conditions when hydrolytic condensation is carried out by adding 100% equivalent of water, especially the presence and type of diluent, for example, alcohol such as ethanol as the diluent When the hydrolysis is performed in the presence of the organic solvent, the weight average molecular weight can be 1300 to 1800, and more than 70% can be stably generated in the range of about 1600 to 1800. (The molecular weight described above is a weight average molecular weight determined by standard polystyrene conversion based on a measurement value by GPC.)
[0038]
As described above, the reactive ultrafine silica of the present invention has a very small inertia radius with respect to its molecular weight, and thus is considered to have an unusually dense structure. Silica in the form. The reactive ultrafine silica of the present invention has a large number of reactive functional groups that can be hydrolytically condensed, such as hydroxyl groups and alkoxy groups. For example, when hydrolysis is carried out by adding 100% equivalent of water in the presence of ethanol as a diluent, reactive ultrafine silica is converted into hydroxyl groups, methoxy groups, and ethoxy groups as reactive functional groups by alcohol exchange reaction. It has a group. For example, the number of moles of a hydroxyl group is 0.6 times or 0.7 times, more than 0.8 times the total number of moles of an alkoxy group, that is, a methoxy group and an ethoxy group. It is also possible to easily form reactive ultrafine silica that is 5 times or even 2 times or more. As described above, the reactive ultrafine silica of the present invention having a large amount of reactive functional groups is rich in reactivity, and the matured product of the present invention containing this has excellent performance when blended with various organic components. can do.
[0039]
That is, the coating liquid of the present invention obtained by blending the matured product of the present invention containing the reactive ultrafine silica of the present invention with the reactive organic compound described below has excellent cross-linking reactivity between components during film formation. For example, it can be cured at room temperature and can be formed outdoors. Moreover, since the crosslinking density between these components also increases, it is possible to form a coating solution that exhibits extremely excellent characteristics such as high hardness. Further, even when hydrolysis is performed without the presence of an organic solvent as a diluent, the produced reactive ultrafine silica has a large number of hydroxyl groups and methoxy groups. For this reason, in addition to forming a coating solution that exhibits extremely high characteristics of high hardness even with an aged product containing this, it can be a coating solution that does not substantially contain an organic solvent. It is also suitable when these organic solvents are not desirable.
[0040]
Water and other various solvents or dispersion media can be added to the aged product. In particular, when water is used as a diluent and the pH is 3 or less when obtaining a blended solution, it is desirable to add these to a weak acid having a pH of about 3 to 5 for convenience of use. This is because a strong acid having a pH of 3 or less is inconvenient to use, and when neutral to alkaline, it tends to gel and may cause problems in the storage stability of the liquid. When water is added as a diluent and further water is added to the aged product, the total amount of water is usually 200 to 100,000 parts by weight, preferably 350 to 35,000 parts by weight based on 100 parts by weight of tetramethoxysilane. Part. When the amount is 200 parts by weight or less, the storage stability of the obtained coating solution is lowered, and the resulting coating tends to have a film thickness and cracks tend to occur. On the other hand, when the weight is 100,000 or more, the obtained coating becomes extremely thin. In addition, when an organic solvent such as alcohol is used as a diluent, the OH concentration around the microparticles is lower than when water is used as the diluent, so the storage stability is further improved. It is also possible to add the reactive organic compounds mentioned.
[0041]
In the present invention, a reactive organic compound having two or more functional groups capable of undergoing a condensation reaction with the hydrolyzed condensate of tetramethoxysilane in the aged product is then added to the aged product described above. That is, the hydrolyzed condensate of tetramethoxysilane in the aging product of the present invention has a large number of reactive polycondensable reactive groups such as hydroxyl groups and alkoxy groups. In the present invention, a reactive organic compound having two or more groups capable of hydrolytic polycondensation with each other is added to the aged product.
[0042]
Examples of such a reactive organic compound include those having two or more carboxyl groups, hydroxyl groups, amino groups, alkoxy groups, etc. (excluding tetramethoxysilane). Specifically, for example,
(I) Silane coupler (generally RSiX₃: X is a hydrolyzable group, R is a functional group)
(Ii) Alkyl alkoxy silicones
(Iii) Polymers such as acrylic resins, epoxy resins, polyester resins, urethane resins, etc., having two or more groups and epoxy structures as described above
(Iv) Polyhydric alcohols such as 1,4-butanediol, glycerin, catechol, resorcin, and the like.
[0043]
More specifically, for example, as the silane coupler (i),
[Chemical formula 5]

Methyl acrylate system such as
[0044]
[Chemical 6]

Epoxy system, etc.
[0045]
[Chemical 7]
H₂NC₃H₆Si (OC₂H₅)₃,
H₂NC₂H₄NHC₃H₆Si (OCH₃)₃Si (OCH₃)₃,
H₂NCONHC₃H₆Si (OC₂H₅)₃,
Amino-based, etc.
[0046]
[Chemical 8]
CH₂= CHSi (OC₂H₅)₃,
CH₂= CHSi (OCH₃)₃,
CH₂= CHSi (OC₂H₄OCH₃)₃,
Vinyl-based, etc.
[0047]
[Chemical 9]
HS-C₃H₆Si (OCH₃)₃, HS-C₃H₆Si (OC₂H₅)₃,
HS-C₃H₆Si (OC₂H₄OCH₃)₃,
Mercapto, such as
Etc.
[0048]
Any of these can be suitably used, but can be appropriately selected depending on the type of the substrate to be coated.
For example, if the acrylic resin base material is methyl acrylate, other general resin base materials are vinyl, and if it is a metal base material, an epoxy silane coupler is selected to obtain a coating with particularly good adhesion. Can do. If the substrate is a glass substrate, excellent adhesion can be obtained even if any silane coupler is used.
[0049]
In addition, as (ii) alkylalkoxysilicones,
[Chemical Formula 10]
(CH₃O)₃Si- {OSi (CH₃)₂}_n-{OSi (OCH₃)₂    }_m-OCH₃
n, m = 1-10
Etc.
[0050]
Further, examples of the polymer (iii) include the following.
[0051]
(1) Acrylic resin
(A)
Embedded image

[0052]
(B)
Γ-MTS (γ-methacryloxypropyltrimethoxysilane added to the structure (a)
[0053]
Embedded image

[0054]
Embedded image

[0055]
These are examples of the reactive organic compound that can be used in the present invention, and the reactive organic compound that can be used in the present invention is not limited to these, and as described in the gist of the present invention, Any one having two or more functional groups capable of undergoing a condensation reaction with an aged product can be used.
Moreover, 2 or more types of said reactive organic compounds can also be used together according to the objective.
[0056]
For example, by using a resin component and a silane coupler together, such as an epoxy resin and an epoxy silane coupler, an acrylic resin and an acrylic silane coupler, a polyester resin and an epoxy silane coupler, the adhesion to the substrate is improved. The compatibility between the resin component and tetramethoxysilane can be further selected depending on the purpose, such as further improving the properties of the coating film that can be obtained. In the combined use, two or more kinds may be blended in advance or each may be added to the aged product.
[0057]
The addition amount of the reactive organic compound is usually in the range of 1 to 300 parts by weight, preferably 4 to 150 parts by weight, based on 100 parts by weight of the aged product as a solid content. SiO in the film₂When the concentration is in the range of 94 to 5%, preferably 80 to 10%, particularly excellent film characteristics and storage stability in the liquid can be expressed.
If the amount of the reactive organic compound is too large, the hardness of the resulting coating film tends to decrease, and the storage stability of the coating liquid tends to decrease. Moreover, when there are too few reactive organic compounds, the flexibility of a coating film will fall and it will be easy to generate | occur | produce a crack.
[0058]
In addition, when using a silane coupler as a reactive organic compound, in order to hydrolyze this, water is added. At this time, it may be added together with the silane coupler, or may be added together when water of 100% equivalent or more of hydrolysis is added in advance to hydrolyze tetramethoxysilane.
In blending these aged products and reactive organic compounds, a solvent, a dispersion medium, a curing catalyst, and the like can be added as necessary.
[0059]
For example, in the case of film formation to be described later, particularly in the case of the spray method or dip method, in order to prepare a coating liquid having a viscosity and a nonvolatile component content according to the target film physical properties such as coating conditions and film thickness, these solvents or dispersion media Can be added.
As the solvent, those having compatibility with both the aged product and the reaction organic compound are suitable. For example, one or two kinds of alcohols, glycol derivatives, hydrocarbons, esters, ketones and ethers are used. The above can be mixed and used.
[0060]
Specific examples of alcohols include methanol, ethanol, isopropyl alcohol, n-butanol, isobutanol, octanol and the like, and glycol derivatives include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n. -Propyl ether, ethylene glycol mono n-butyl ether and the like.
[0061]
As the hydrocarbons, benzene, kerosene, toluene, xylene and the like can be used, and as the esters, methyl acetate, ethyl acetate, butyl acetate, methyl acetoacetate, ethyl acetoacetate and the like can be used. Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetyl acetone, and ethers such as ethyl ether, butyl ether, 2-α-methoxyethanol, 2-α-ethoxyethanol, dioxane, furan, and tetrahydrofuran can be used.
[0062]
In some cases, a dispersion medium can also be used. As the dispersion medium to be used, for example, a water-surfactant system is suitable, and as the surfactant, an anionic, cationic or nonionic one is generally used. Examples of anionic surfactants include carboxylates, sulfonates, sulfate esters, phosphate esters, and the like, and cationic ones include organic or inorganic acid salts of primary to tertiary amines, quaternary ammonium salts, Polyoxyethylene alkylamine salts and the like, and nonionic ones include sorbitan dialkyl ester, ethylene glycol condensate of sorbitan alkyl ester, aliphatic alcohol polyethylene glycol condensate, alkylphenol polyethylene glycol condensate, polypropylene glycol polyethylene glycol condensate Etc.
[0063]
These surfactants are generally used in an amount of about 0.1 to 5% with respect to the aged product. For dispersion (emulsification), an appropriate amount of water is used to obtain a homomixer, a colloid mill, It can be performed by a known method such as ultrasonic waves.
[0064]
Of these solvents and dispersion media, it is usually preferable to use a solvent because the physical properties of the resulting coating film and the stability of the coating liquid are excellent. In addition, the solvent type may be selected according to the characteristics of the desired coating film, coating conditions, etc., but in general, hydrocarbons such as benzene, toluene and xylene, and ketones such as methyl ethyl ketone are generally used. When is used, since the solvent removal rate at the time of curing the coating film is appropriate, the surface gloss of the resulting coating film is particularly excellent, and a desired film thickness can be easily obtained.
In addition, generally, it may be appropriately selected according to the kind of the reactive organic compound to be used and the desired film characteristics.
[0065]
Depending on the type of reactive organic compound, there are many functional groups, and it may be desirable to further add a catalyst in order to improve the curing rate after film formation. A catalyst is sufficient.
The order of addition when using these solvents and catalysts is not particularly limited, and may be added to tetramethoxysilane simultaneously with the reactive organic compound, or may be added after achieving the compatible state described below. .
[0066]
In blending the aged product with the reactive organic compound, in order to bring these components into a desired compatible state, the reactive organic compound is added to the aged product and then allowed to stand for a certain period of time. By leaving it to stand, the hydrolyzed condensate of tetramethoxysilane having a reactive group such as a hydroxyl group or an alkoxyl group generated in the aged product, and a reactive organic compound having a functional group capable of reacting therewith However, it is conceivable that a compatible state occurs due to bonding due to hydrogen bonding and partial reaction. As a result, when the resulting coating liquid is formed into a film, the reaction between the functional group of the tetramethoxysilane hydrolyzed condensate and the reactive organic compound is accelerated as the solvent evaporates. Can be formed.
[0067]
Depending on the type of organic compound used, the time required for standing cannot be generally determined depending on the size of these molecules, the amount of functional groups, the type, etc., but if the molecular weight is relatively small, such as a silane coupler, for example. About one hour is often sufficient, and some resin components having a large molecular weight need to be left for several days. If the standing time is sufficient, it becomes a transparent coating film after film formation, so that it can be confirmed that each component in the coating solution is in a compatible state. In addition, the standing time required to set it as a compatible state can be shortened by heating to such an extent that it does not gelatinize, or stirring.
[0068]
The coating liquid of the present invention thus obtained is formed into a film, such as an impregnation method, a spin coater method, a dip method, or a spray method, on a substrate, such as a polymer, metal, or ceramic, or mixed with powder to form a film. . When forming a film, for example, after applying a coating solution, it is left at room temperature for about 1 to 10 minutes to remove the solvent, and then heated to carry out a crosslinking reaction between the components in the solution by a dehydration condensation reaction. The film can be cured by proceeding, but the present invention is not limited to this, and a curing method according to the purpose can be selected.
[0069]
For example, when heating directly without removing the solvent at room temperature in advance, an additive such as a solvent having an evaporation rate suitable for use conditions such as a curing temperature, such as an antifoaming agent and a leveling agent, is added as appropriate, and the coating surface is It can be smooth. The heating temperature is not particularly limited, and may be low as long as a sufficient time is taken. Usually, crosslinking can proceed at a wide range of temperatures from about -20 to 300 ° C, but practically 20 to 200 °. About C is sufficient. Although the time required for the curing depends on the catalyst used, a coating film having sufficient hardness can be obtained in a few minutes if the temperature is increased to about 150 ° C. efficiently. The heating furnace may be a general-purpose furnace such as a gas furnace or an electric furnace. In addition, according to the coating liquid of the present invention, since the hydrolyzate of tetramethoxysilane forms fine particles by sufficient aging, the compatibility with organic components such as resins is good, and the progress rate and progress of the crosslinking reaction. The degree is very good. For this reason, there is no particular need for a heating step, and if the drying process is carried out by drying at room temperature, the crosslinking reaction of each component in the liquid also proceeds, and a coating film having sufficient high hardness can be obtained. Also suitable for use in
[0070]
When film curing is performed by drying at room temperature, it takes a slightly longer time than when heating, but it is usually sufficient to leave it for about 12 hours. In this case, it is desirable to add a catalyst immediately before coating. As the catalyst used here, the above-mentioned catalysts can be used, but particularly preferred are dibutyltin diacetate, monobutyltin triacetate, monobutyltin trioctoate, dioctyltin dilaurate, dibutyltin lauryl mercaptan, dibutyltin dilaurate, bis (dibutyl). Organotin compounds such as tin monoacetate oxide, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ- Examples include amine-based curing catalysts such as aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and among these, dibutyltin is particularly preferred. Acetate, there is N-beta (aminoethyl) .gamma.-aminopropyltrimethoxysilane, N-beta (aminoethyl) .gamma.-aminopropyl one or more excellent effect of triethoxysilane.
[0071]
Since the coating liquid of the present invention has good re-coating property, depending on the application, it may be further re-coated and dried. However, according to the coating liquid of the present invention, a film having a thickness of 10 μm or more can be applied once. Thickness can be obtained.
The coating itself can be performed by a conventional method, and the film thickness can also be appropriately selected.
The film thickness can be selected by a conventional method, for example, by adjusting the concentration of non-volatile components in the liquid, the viscosity of the liquid, the pulling speed in the dip method, the spraying time in the spray method, or by performing recoating. Can be selected. Furthermore, the film thickness obtained can be changed greatly by selecting the reactive organic compound to be used.
[0072]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. Parts and% are parts by weight and% by weight unless otherwise specified.
Example 1
[Production of dechlorinated water]
Industrial water in Kitakyushu City was sterilized with chlorine, suspended solids were separated with a coagulating sedimentation device using polyaluminum chloride as a coagulating sedimentation agent, and further filtered with a sand filter to obtain factory filtered water. This factory filtered water was treated with a cation exchange resin, vacuum degassed, and further treated with an anion exchange resin, and then with an anion / cation exchange resin, 0.05 micro Siemens / cm or less, pH 6-8, SiO₂Degassed dechlorinated water having a concentration of 20 microgram / liter or less, Fe of 20 microgram / liter or less, A〓 of 20 microgram / liter or less, and C〓 of 20 microgram / liter or less was obtained.
[0073]
[Synthesis of tetramethoxysilane oligomer]
To a 500 ml four-necked round bottom flask equipped with a stirrer, a condenser for reflux and a thermometer, 234 g of tetramethoxysilane and 74 g of methanol were added and mixed. Hydrolytic condensation reaction was performed at 2 ° C. for 2 hours.
Next, the condenser was replaced with a distillation pipe, and the temperature was raised until the internal temperature reached 130 ° C. to distill methanol. In this way, a partially hydrolyzed condensate was obtained (hydrolysis rate 40%). Oligomers having a polymerization degree of 2 to 8 were confirmed, and the weight average molecular weight was 550.
[0074]
The amount of monomer in the obtained partial hydrolysis-condensation product (hereinafter referred to as “tetramethoxysilane oligomer”) was 5%. Subsequently, tetramethoxysilane oligomer was placed in a flask heated to 130 ° C., and the temperature was raised to 150 ° C. and held for 3 hours while discharging the vaporized monomer together with an inert gas. The monomer amount in the tetramethoxysilane oligomer after the monomer removal thus obtained was 0.2%.
[0075]
(Preparation of aged product)
62.42 g of ethanol was added to 30.77 g of the tetramethoxysilane oligomer thus obtained, and then 0.31 g of maleic acid and 6.50 g of dechlorinated water were added. The amount of water added is 113% with respect to the amount of theoretically completely hydrolyzing the tetramethoxysilane oligomer. The mixture was aged at room temperature for 4 days to obtain an aged product.
[0076]
[Confirmation of microparticles]
Aged product (Composition A, SiO) obtained in [Preparation of Aged Product]₂Equivalent concentration 16 wt%, 8.1 vol%), and a solution obtained by diluting this with ethanol about 4 times (Composition B, SiO₂For the converted concentration (4.3 wt%, 2 vol%), analysis by small angle X-ray scattering was performed under the following conditions.
[0077]
Measuring device: Kraton Compact Camera manufactured by Anton Paar
X-ray source: 50 kV, 200 mA, Cu—Kα ray is monochromatic with Ni-filter.
Optical system conditions: Distance between sample and light receiving slit = 20 cm Internal vacuum path = 19 cm
Entrance slit = 80 μm, light receiving slit = 200 μm, beam length = 16 mm
[0078]
Sample cell: Quartz capillary (diameter approx. 1 mm, wall thickness 10 μm)
Other conditions: Room temperature. Step scan method Operating range 2θ = 0.086 to 8.1 deg
90sec / point
Data correction: The background correction was corrected using the scattering when the quartz capillary was filled with water. X-ray absorption correction was also performed.
Analysis software: Slit correction and inverse Fourier transform were performed using the analysis software ITP-81 (O. Glatta; J. Appl. Cryst.,10. 415-421 (1977). )It was used.
[0079]
FIG. 1 and FIG. 2 show the measurement data (background correction and absorption corrected) of the scattering intensity with respect to the moving distance of the scattered X-rays in the light receiving slit of the composition A and the composition B.
FIG. 3 and FIG. 4 show the point beam data of the composition A and the composition B after the slit correction.
[0080]
From these Fig.-3 and Fig.-4, Guinier's formula I = C exp (-H²Rg²/ 3) (I: scattering intensity, H: scattering vector (= 2πsin 2θ / λ), Rg: radius of inertia, C: Const, λ: Cu-Kα ray wavelength, 2θ: spread angle)
As shown in FIGS. 5 and 6, the maximum value of the inertia radius is 7.0 mm for the composition A (assuming a spherical shape, the actual radius R = (5/3)^1/2From Rg, the radius was 9.0 Å), and the composition B was 6.0 半径 (assuming a spherical shape, the radius was 7.7 Å). Figures 7 and 8 show the results of inverse Fourier transform of Fig. 3 and Fig. 4 to obtain the distribution of radius (assumed to be spherical). The maximum value of the radius was about 6 mm and 7 mm, respectively.
[0081]
The tetramethoxysilane / oligomer obtained in [Synthesis of tetramethoxysilane / oligomer] was analyzed by small-angle X-ray scattering under the same conditions as in [Confirmation of microparticles]. FIG. 9 shows the measurement data of the scattering intensity. As is clear from this, no structures such as fine particles were observed.
[0082]
(Measurement of molecular weight)
The molecular weight of composition A was measured under the following conditions.
Deaerator: Shodex DEGAS (made by Showa Denko)
Pump: Shimadzu LC6A (manufactured by Shimadzu Corporation)
Incubator: Nishio Kogyo
Column: Tosoh TSK-GEL for GPC
G-4000H, G-2000H, G-1000H (manufactured by Toyo Soda)
[0083]
Detector: Shodex RI SE-51 (refractive index detector) (made by Showa Denko)
Data collector: Shimadzu C-R3A (manufactured by Shimadzu Corporation)
Data processing: PC (PC-9801 system)
Column temperature: 40 ° C
Injection temperature: room temperature
Pump temperature: Room temperature
Solvent: Tetrahydrofuran, 1.0 ml / min
Molecular weight calculation method: Standard polystyrene conversion
The results are shown below.
[0084]
[Table 1]

The chlorine concentration of Composition A was measured and found to be 1.5 ppm or less.
[0085]
(Measurement of the amount of reactive functional groups)
After the composition A was sealed and allowed to stand at room temperature for 17 days, the methanol and ethanol in the liquid were measured by gas chromatography, and the water in the liquid was measured by Karl Fischer analysis. The amount of reactive functional groups possessed by the fine silica was calculated. The analysis conditions are as follows:
[0086]
Gas chromatography analysis conditions:
Injection temperature: 180 ° C
Column temperature: 180 ° C
TCD (detector): 200 ° C
Carrier gas: He 40ml / min
Current current: 100 mA
Filler: Porapaq type Q
[0087]
As a result, the amount of methanol in the liquid was 18.8% (0.588 mol), the amount of ethanol was 56.7% (1.233 mol), and the amount of water was 1.21% (0.0672 mol). The amount of water produced was 0.3008 mol. Therefore, when the amount of the reactive functional group of the reactive ultrafine silica in the composition A was calculated, it was 13.5 mol% for methoxy group, 40.8 mol% for ethoxy group, and 45.2 mol% for hydroxyl group.
[0088]
[Preparation of coating solution]
To 46.70 g of this aged product, 53.3 g of a hydroxy group-containing acrylic resin was added and left for 12 hours to obtain a coating solution. The non-volatile component in the liquid is 21.3%, and the SiO2 concentration in the film corresponds to 35%.
[0089]
[Formation of coating film]
The coating solution thus obtained was applied on a mild steel substrate with a 250 μm applicator. Subsequently, it was heat-cured at 150 ° C. for 2 hours in an electric furnace. The obtained coating film thickness was 12 μm, it was transparent, and the pencil hardness was 2H.
[0090]
Example 2
(Preparation of aged product)
43.5 g of ethanol was added to 29.72 g of the tetramethoxysilane oligomer obtained in Example 1 [Synthesis of tetramethoxysilane oligomer], and then 0.38 g of maleic acid and 8.6 g of dechlorinated water were added. The mixture was aged at room temperature for 4 days to obtain an aged product.
[0091]
[Preparation of coating solution]
17.8 g of a silane coupler (Nippon Unica product number A-187) having the following structural formula was added to the aged product, and the mixture was allowed to stand for 3 hours to obtain a coating solution.
[0092]
The glass substrate was impregnated into the obtained coating solution and pulled up at a lifting speed of 3 mm / second. Next, after heating and curing in an electric furnace at 60 ° C. for 1 hour, it was left for 2 days. The resulting coating film had a pencil hardness of 9H. As for chemical resistance, 5% sulfuric acid was dropped, and after standing for one day, the coating film was visually observed, but no change was observed.
The coating solution did not change in viscosity even after being left for 22 weeks.
[0093]
Embedded image

[0094]
Comparative Example 1
First, 17.8 g of the silane coupler (Nippon Unica product number A-187) was added to and mixed with 29.72 g of the tetramethoxysilane oligomer obtained in Example 1, and then 43.5 g of ethanol and 0. 0 of maleic acid were mixed. 38 g and 8.6 g of dechlorinated water were added. Aged at room temperature for 4 days to obtain a coating solution. A coating film was formed by the same operation as in Example 2, but the pencil hardness of the coating film was 5H even after 2 days.
[0095]
Example 3
[Preparation of coating solution]
49.31 g of ethanol was added to 34.99 g of the tetramethoxysilane oligomer obtained in Example 1, and then 0.38 g of maleic acid and 8.32 g of dechlorinated water were added. The amount of water added is 127% with respect to the theoretically complete hydrolysis of the tetramethoxysilane oligomer. The mixture was aged at room temperature for 2 days to obtain an aged product. Next, 7.00 g of the silane coupler (Nippon Unica product number A-187) used in Example 2 was added and allowed to stand for 2 hours to obtain a coating solution.
[0096]
An aluminum substrate (JIS 1100, thickness 0.1 mm) was impregnated into the obtained coating solution and pulled up at a lifting speed of 10 mm / sec. Subsequently, it was heat-cured at 150 ° C. for 1 hour in an electric furnace. Even when the obtained coating film thickness was 3.4 μm, pencil hardness 9H, diameter 6φmm SUS304 bar and bent at 180 ° C., no crack was generated. As for chemical resistance, 5% sulfuric acid was dropped, and after standing for one day, the coating film was visually observed, but no change was observed.
The coating solution did not change in viscosity even after being left for 22 weeks.
[0097]
Example 4
51.24 g of ethanol was added to 29.15 g of the tetramethoxysilane oligomer obtained in [Synthesis of tetramethoxysilane oligomer] in Example 1, and then 0.35 g of maleic acid and 7.61 g of dechlorinated water were added. The amount of water added is 139% with respect to 100% equivalent of hydrolysis of tetramethoxysilane oligomer. Aged at room temperature for 3 days. Next, 11.66 g of a silane coupler (“KBM-503” manufactured by Shin-Etsu Chemical Co., Ltd.) having the following structural formula was added and left for 2 hours to obtain a coating solution.
[0098]
An aluminum substrate (JIS 1100, thickness 0.1 mm) was impregnated into the obtained coating solution and pulled up at a lifting speed of 10 mm / sec. Subsequently, it was heat-cured at 150 ° C. for 1 hour in an electric furnace. Even when the obtained coating film thickness was 2.6 μm, pencil hardness 9H, diameter 6φmm SUS304 rod and bent at 180 ° C., no crack was generated. As for chemical resistance, 5% sulfuric acid was dropped, and after standing for one day, the coating film was visually observed, but no change was observed.
The coating solution did not change in viscosity even after being allowed to stand for 26 weeks.
[0099]
Embedded image

[0100]
Example 5
55.34 g of ethanol was added to 23.57 g of the tetramethoxysilane oligomer obtained in Example 1, and then 0.35 g of maleic acid and 6.61 g of dechlorinated water were added. The amount of water added is 150% with respect to 100% equivalent of hydrolysis of tetramethoxysilane oligomer. Aged for 2 days at room temperature. Next, 14.14 g of a silane coupler (“KBM-1003” manufactured by Shin-Etsu Chemical Co., Ltd.) having the following structural formula was added and left for 2 hours to obtain a coating solution.
[0101]
An aluminum substrate (JIS 1100, thickness 0.1 mm) was impregnated into the obtained coating solution, and pulled up at a lifting speed of 20 mm / min. Subsequently, it was heat-cured at 150 ° C. for 1 hour in an electric furnace. The obtained coating film thickness was 2.1 μm, pencil hardness was 9H, diameter was 6φ mm, and no crack was generated even when bending at 180 ° C. with a SUS304 bar. As for chemical resistance, 5% sulfuric acid was dropped, and after standing for one day, the coating film was visually observed, but no change was observed.
The coating solution was not changed in viscosity even after being left for 40 weeks.
[0102]
Embedded image
CH₂  = CHSi (OCH₃  )₃
[0103]
Example 6
To 100 parts by weight of tetramethoxysilane oligomer obtained by synthesis of tetramethoxysilane oligomer of Example 1, 20 parts by weight of 0.32% by weight maleic acid aqueous solution (pH 1.8) was added at room temperature. The mixture was stirred for 30 minutes to obtain a uniform transparent aged product. Subsequently, 60 weight part of epoxy-type silane couplers (Nihon Unicar A-187) were added, and it stirred at room temperature for 30 minutes. Subsequently, 180 parts by weight of demineralized water was added and stirred at room temperature for 30 minutes. The resulting coating solution had a pH of 3.0.
[0104]
An aluminum substrate (JIS 1100, thickness 0.1 mm) was impregnated into the obtained coating solution and pulled up at a pulling rate of 5 mm / sec. The coated substrate was allowed to stand at room temperature for 5 minutes, and then cured by heating in an electric furnace at 150 ° C. for 1 hour. The resulting coating film had a thickness of 3.2 μm, a pencil hardness of 9H, and a diameter of 6φ mm. Even if it was bent 180 °, no crack was generated. As for chemical resistance, 5% sulfuric acid was dropped, and after standing for one day, the coating film was visually observed, but no change was observed.
[0105]
Example 7
A coating solution was obtained in the same manner as in Example 4 except that 60 parts by weight of a vinyl silane coupler (KBE-1003 manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of the epoxy coupler to obtain a coating film. The resulting coating film had a film thickness of 1.9 μm, pencil hardness of 9H, and a SUS rod having a diameter of 6φ mm, and cracking did not occur even when bent 180 °. As for chemical resistance, 5% sulfuric acid was dropped, and after standing for one day, the coating film was visually observed, but no change was observed.
[0106]
Example 8
To 100 parts by weight of tetramethoxysilane oligomer obtained in [Synthesis of tetramethoxysilane oligomer] in Example 1, 60 parts by weight of 1% by weight maleic acid aqueous solution (pH 1.5) was added at room temperature. The mixture was stirred for 5 minutes to obtain a transparent hydrolyzed solution. Next, 20000 parts by weight of demineralized water was added. Subsequently, 30 parts by weight of an epoxy-based silane coupler (product number A-187 manufactured by Nippon Konica Co., Ltd.) was added and stirred at room temperature for 1 hour. The resulting coating solution had a pH of 3.7.
[0107]
To 2500 parts by weight of this coating liquid, 1000 g of aluminum hydroxide powder (Alcoa Kasei Co., Ltd., product number OC-2000 average particle size 47 μm) was added and stirred for 20 minutes at 1500 rpm with a Henschel mixer. Thereafter, steam at 110 ° C. was passed through the jacket of the Henschel mixer, the interior of the Henschel mixer was heated to 100 ° C. or higher, and heated for 30 minutes with stirring to obtain a coated aluminum hydroxide powder.
[0108]
Example 9
To 100 parts by weight of tetramethoxysilane oligomer obtained in [Synthesis of tetramethoxysilane oligomer] in Example 1, 60 parts by weight of 1% by weight maleic acid aqueous solution (pH 1.5) was added at room temperature. The mixture was stirred for 5 minutes to obtain a transparent hydrolyzed solution. Next, 43 parts by weight of a vinyl-based silane coupler (KBM-1003 manufactured by Shin-Etsu Chemical Co., Ltd.) was added and stirred at room temperature for 1 hour. Next, 14000 parts by weight of demineralized water was added. The resulting coating solution had a pH of 3.3.
[0109]
To 2500 parts by weight of this coating liquid, 1000 g of aluminum hydroxide powder (Alcoa Chemical Co., Ltd., product number C-385, average particle size: 8 μm) was added, and the mixture was stirred with a Henschel mixer at 1500 rpm for 20 minutes. Thereafter, steam at 110 ° C. was passed through the jacket of the Henschel mixer, the interior of the Henschel mixer was heated to 100 ° C. or higher, and heated for 30 minutes with stirring to obtain a coated aluminum hydroxide powder.
[0110]
Example 10
A solution obtained by diluting 20 parts by weight of the coating liquid obtained in Example 4 with 50 parts by weight of acetone was added to 1000 g of aluminum hydroxide powder (Alcoa Kasei C-385), and the mixture was stirred at 500 rpm for 20 minutes with a Henschel mixer at room temperature. . Thereafter, 110 ° C. steam was passed through the jacket of the Henschel mixer, the inside of the Henschel mixer was heated to 100 ° C. or higher, and heated for 30 minutes with stirring to obtain a coated aluminum hydroxide.
[0111]
Example 11
A coated aluminum hydroxide was obtained in the same manner as in Example 10 except that 20 parts by weight of the coating solution obtained in Example 5 was used instead of the coating solution obtained in Example 4.
[0112]
Example 12
(Preparation of aged product)
6.52 g of water, 0.31 g of aluminum trisacetylacetonate, 30.77 g of tetramethoxysilane oligomer obtained in Example 1 [Synthesis of tetramethoxysilane oligomer], “Solmix A-11” (Japan) Chemical product Co., Ltd. product, ethanol 85.5%, IPA 1.1%) 62.4 g was added. The amount of water is 113% based on the amount capable of theoretically completely hydrolyzing and condensing tetramethoxysilane oligomer. The product was allowed to stand at room temperature for 1 day to obtain a colorless and transparent uniform liquid aging product.
[0113]
(Measurement of the amount of reactive functional groups)
The aged product thus obtained was sealed and allowed to stand at room temperature for 17 days, and then the reactive ultrafine silica in the aged product was analyzed under the same analysis conditions and analysis method as in Example 1 (measurement of the amount of reactive functional groups). The amount of reactive functional group possessed by was calculated.
[0114]
As a result, the amount of methanol in the liquid was 18.9% (0.591 mol), the amount of ethanol was 57.1% (1.241 mol), and the amount of water was 1.15% (0.0639 mol). The amount of water produced was 0.3041 mol. Therefore, when the amount of the reactive functional group of the reactive ultrafine silica in the aged product was calculated, it was 13.2 mol% for methoxy group, 40.3 mol% for ethoxy group, and 46.0 mol% for hydroxyl group.
[0115]
[Preparation of coating solution]
To 46.70 g of this aged product, 53.3 g of a hydroxy group-containing acrylic resin was added and left for 12 hours to obtain a coating solution. The non-volatile component in the liquid is 21.3%, and the SiO2 concentration in the film corresponds to 35%.
[0116]
[Formation of coating film]
The coating solution thus obtained was applied on a mild steel substrate with a 250 μm applicator. Subsequently, it was heat-cured at 150 ° C. for 2 hours in an electric furnace. The obtained coating film thickness was 11 μm, it was transparent, and the pencil hardness was H.
[0117]
Comparative Example 2
[Preparation of coating solution]
To 14.3 g of tetramethoxysilane oligomer obtained in Example 1 [Synthesis of tetramethoxysilane oligomer] 1.07 g of water, 0.28 g of aluminum trisacetylacetonate, 31.15 g of “Solmix A-11”, And 53.2 g of hydroxyl group-containing acrylic resin was added and allowed to stand for 12 hours to obtain a coating solution. The non-volatile component in the liquid is 21.3%, and the SiO2 concentration in the film corresponds to 35%.
[0118]
[Formation of coating film]
The coating liquid thus obtained was applied on a mild steel substrate by the same operation as in Example 10, and was similarly heat-cured. The obtained coating film thickness was 7 to 8 μm, it was transparent, and the pencil hardness was 5B or less. Moreover, stickiness was seen on the coating film surface.
[0119]
Example 13
[Preparation of coating solution]
To 43.88 g of the aged product obtained in Example 12 [Preparation of coating solution], 56.12 g of a hydroxyl group-containing polyester resin was added and allowed to stand for 12 hours to obtain a coating solution. The non-volatile component in the liquid is 35%, and the SiO2 concentration in the film corresponds to 20%.
[0120]
[Formation of coating film]
The coating solution thus obtained was coated and heat-cured in the same manner as in Example 10 on a mild steel substrate. The obtained coating film thickness was 35 μm, it was transparent, and the pencil hardness was 5H.
[0121]
[Measurement of adhesion strength]
The coating solution was applied to a glass-filled epoxy resin substrate using a 500 μm applicator 7 days after the preparation, and cured by heating in an electric furnace at 150 ° C. for 1 hour. The adhesive strength of the obtained transparent film is 12 kg / cm²Met. The adhesive strength of the transparent film obtained by the same operation using a ceramic substrate instead of the glass-filled epoxy substrate is 50 kg / cm.²And it had excellent adhesion.
[0122]
[Measurement of boiling water resistance and alkali resistance]
The coating film obtained in [Formation of coating film] was placed in boiling water together with the substrate and heated for 3 hours, but no change was observed. Further, 5% NaOH was dropped onto the coating film and allowed to stand for 15 hours, but only slight whitening was observed.
[0123]
Comparative Example 3
[Preparation of coating solution]
To 1.17 g of the tetramethoxysilane oligomer obtained in Example 1 [Synthesis of tetramethoxysilane oligomer], 0.99 g of water, 0.81 g of aluminum trisacetylacetonate, 26.60 g of methyl ethyl ketone, 4.42 g of isopropanol and hydroxy 54.8 g of group-containing polyester resin was added and allowed to stand for 12 hours to obtain a coating solution. . The non-volatile component in the liquid is 34.2%, and the SiO2 concentration in the film corresponds to 20%.
[0124]
[Formation of coating film]
The coating solution thus obtained was coated on a mild steel substrate in the same manner as in Example 12 except that a 150 μm applicator was used, and was similarly heat-cured. The obtained coating film thickness was 15 μm, and the pencil hardness was F.
[0125]
[Measurement of boiling water resistance and alkali resistance]
When the coating film obtained in the above [Formation of coating film] was placed in boiling water together with the substrate and heated for 3 hours, whitening and rough skin occurred on the coating film surface. When 5% NaOH was dropped onto the coating film and left for 15 hours, the coating film dissolved and disappeared.
[0126]
Example 14
[Preparation of coating solution]
35.06 g of silyl group-containing acrylic resin was added to 64.94 g of the aged product obtained in Example 12 [Preparation of coating solution], and the mixture was allowed to stand for 1 week to obtain a coating solution. The non-volatile component in the liquid is 29.7%, and the SiO2 concentration in the film corresponds to 35%.
[0127]
[Formation of coating film]
The coating solution thus obtained was coated and heat-cured in the same manner as in Example 10 on a mild steel substrate. The obtained coating film thickness was 27 μm, it was transparent, and the pencil hardness was 4H.
[0128]
[Formation of coating film by drying at room temperature]
The above coating solution was applied onto a mild steel substrate using a 50 μm applicator. It was left in a room at 20 ° C. for 1 week. The obtained coating film had a film thickness of 5 μm, was transparent, and had a pencil hardness of 2H or more.
[0129]
Comparative Example 4
[Preparation of coating solution]
To 25.95 g of tetramethoxysilane oligomer obtained in Example 1 [Synthesis of tetramethoxysilane oligomer], 1.94 g of water, 0.51 g of aluminum acetyl acetate, 25.71 g of isopropanol and silyl group-containing acrylic resin 45. 90 g was added and allowed to stand for 12 hours to obtain a coating solution. . The non-volatile component in the liquid is 38.7%, and the SiO2 concentration in the film corresponds to 35%.
[0130]
[Formation of coating film]
The coating solution thus obtained was applied on a mild steel substrate by the same operation as in Example 12, and was similarly heat-cured. The obtained coating film thickness was 45 μm, and the pencil hardness decreased to H.
[0131]
Example 15
[Preparation of coating solution]
To 46.7 g of the aged product obtained in Example 12 [Preparation of coating solution], 13.9 g of 1,4-butanediol and 39.5 g of “Solmix A-11” were added and allowed to stand for 12 hours. Got. The non-volatile component in the liquid is 21.3%, and the SiO2 concentration in the film corresponds to 35%.
[0132]
[Formation of coating film]
The coating solution thus obtained was applied onto a mild steel substrate with a 150 μm applicator. Subsequently, it was heat-cured at 150 ° C. for 2 hours in an electric furnace. The obtained coating film thickness was 8 μm, it was transparent, and the pencil hardness was 7H.
[0133]
Comparative Example 5
[Preparation of coating solution]
To 14.3 g of tetramethoxysilane oligomer obtained in Example 1 [Synthesis of tetramethoxysilane oligomer], 1.08 g of water, 0.21 g of aluminum trisacetylacetonate, 13.8 g of 1,4-butanediol, and 70.5 g of “Solmix A-11” was added and allowed to stand for 12 hours to obtain a coating solution. . The non-volatile component in the liquid is 21.3%, and the SiO2 concentration in the film corresponds to 35%.
[0134]
[Formation of coating film]
The coating solution thus obtained was applied by the same operation as in Example 10 except that it was coated on a mild steel substrate with a 150 μm applicator, and was similarly heat-cured. The obtained coating film thickness was 8 μm, and the pencil hardness was reduced to 5H. In addition, unevenness and peeling were partially observed on the coating film surface.
[0135]
Examples 16-19
To 30.77 g of tetramethoxysilane oligomer obtained in Example 1 [Synthesis of tetramethoxysilane oligomer], 6.52 g of dechlorinated water, 62.5 g of “Solmix A-11” and 0.08 g of 35% hydrochloric acid were added. Added. The amount of water added is 113% with respect to 100% equivalent of hydrolysis with respect to tetramethoxysilane. By aging at room temperature for 1 day, an aged product was obtained. A coating solution was prepared in the same manner as in Examples 12 to 15 except that this aged product was used.
A coating film was formed in the same manner as in Examples 12 to 15 except that these coating solutions were used. Table 1 shows the physical properties of the obtained coating film.
[0136]
[Table 2]

[0137]
Examples 20-23
30.77 g of tetramethoxysilane oligomer obtained in Example 1 [Synthesis of tetramethoxysilane oligomer], 6.52 g of dechlorinated water, 62.5 g of “Solmix A-11”, and the same equivalent as in Example 14 Of nitric acid was added. The amount of water added is 113% with respect to 100% equivalent of hydrolysis with respect to tetramethoxysilane. By aging at room temperature for 1 day, an aged product was obtained. A coating solution was prepared in the same manner as in Examples 12 to 15 except that this aged product was used.
A coating film was formed in the same manner as in Examples 12 to 15 except that these coating solutions were used. Table 2 shows the physical properties of the obtained coating film.
[0138]
[Table 3]

[0139]
Comparative Example 6
Example 1 [Synthesis of tetramethoxysilane / oligomer] 29.15 g of tetramethoxysilane / oligomer was mixed with 59.30 g of ethyl alcohol, and then 0.35 g of curing catalyst maleic acid and 6.16 g of dechlorinated water were added. Added. The amount of water added is 113% with respect to 100% equivalent of hydrolysis of tetramethoxysilane oligomer. The coating solution was obtained by standing for 2 days at room temperature and aging.
An aluminum substrate (JIS 1100, thickness 0.1 mm) was impregnated into the obtained coating liquid, and pulled up at a lifting speed of 3 mm / min. Subsequently, it was heat-cured at 150 ° C. for 1 hour in an electric furnace. The obtained coating film thickness was 0.4 μm and was peeled from the substrate.
[0140]
Comparative Example 7
A coating solution was prepared and formed into a film in the same manner as in Example 2 except that the silane coupler was blended into the tetramethoxysilane oligomer from the beginning.
The pencil hardness of the coating film decreased to 5H.
[0141]
Examples 24-26, Comparative Examples 8-11
A coating solution was obtained in the same manner as in Example 10 except that the amount of water was changed. Using these and the coating liquid of Example 2, a coating film was obtained in the same manner as in Example 2 except that a 150 μm applicator was used. Table 3 shows the physical properties of the obtained coating film.
[0142]
[Table 4]

[0143]
Example 27
The same operation as in Example 12 was performed except that 40.51 g of tetramethoxysilane obtained by the reaction of metal silicon and methanol and 10.83 g of water were blended, and an aged product obtained by aging for 1 day was used. A coating film was formed. The obtained coating film thickness was 12 μm, it was transparent, and the pencil hardness was H.
.
[0144]
Examples 28-32
Using the aged product obtained in Example 12, a silane coupler and water were blended as shown in Table 4, and aged at room temperature for 3 hours to form a coating film. The formation method and curing conditions of the coating film are as shown in Table-4. Table 4 shows the physical properties of the obtained coating film.
[0145]
[Table 5]

[0146]
[Evaluation method for contamination resistance]
(Xylene rubbing)
A cotton cloth was impregnated with xylene, and the surface of the coating film was reciprocated 100 times with force. XX marks indicate that the coating film has been eluted, XX marks indicate innumerable scratches, and ◯ marks indicate almost no scratches.
(Boiling water resistance)
The coating film was immersed in boiling water together with the substrate and boiled for 3 hours. Those that did not show changes were marked with a circle.
[0147]
(Acid resistance test)
5% sulfuric acid was added dropwise to the coating film and left for 15 hours. Those that did not show changes were marked with a circle.
(Adhesion test)
Adhesion was performed by a cross-cut test.
[0148]
Comparative Example 12
Instead of the tetramethoxysilane oligomer obtained in Example 1, 39.7 g of commercially available ethyl silicate (ES40 manufactured by Nippon Colcoat Co.) was used, and the amount of A-11 was changed to 53.5 g. Aged by the method. The coating film obtained in the same manner as in Example 30 except that the aged product thus obtained was used, had a pencil hardness of 4H, which was significantly lower than that in Example 30.
【The invention's effect】
According to the present invention, it can be applied to various substrates, powders, linear materials, etc., has excellent properties such as stain resistance, heat resistance, scratch resistance, weather resistance, high hardness and bending workability It is possible to obtain a thick coating film having excellent thickness without cracks. In addition, since various powder surfaces can be coated with a glassy film and various silane couplers can be used in combination, a remarkable effect can be exhibited in improving the adhesion between various matrices such as FRP and artificial marble and filler. .
[Brief description of the drawings]
FIG. 1 Measurement data of scattering intensity of composition A
FIG. 2 Measurement data of scattering intensity of composition B
FIG. 3 Point beam data after slit correction of composition A
FIG. 4 Point beam data of composition B after slit correction
FIG. 5: Distribution of radius of inertia of fine particles in composition A
FIG. 6: Distribution of inertial radius of fine particles in composition B
FIG. 7: Distribution of assumed sphere radius of microparticles in composition A
FIG. 8: Distribution of assumed sphere radius of fine particles of composition B
FIG. 9: Measurement data of scattering intensity of tetramethoxysilane oligomer obtained in Example 1 [Synthesis of tetramethoxysilane oligomer]

Claims (16)

The weight average molecular weight in terms of standard polystyrene by GPC measurement obtained by hydrolyzing and aging tetramethoxysilane or oligomer thereof by adding water in an amount that is theoretically 100% hydrolytically condensable is 1000 to 1000. in 1800, and the following fine hydrolytic condensate inertia radius 10 Å, blended with reactive organic compound having a pressurized hydrolysis condensation product and a functional group capable of condensation reaction of this 2 above, the transparent coating film Give coating liquid. Tetramethoxysilane or an oligomer, which was hydrolyzed by the addition of theoretically 100% hydrolysis condensation amounts more water, the weight average molecular weight in terms of standard polystyrene by GPC measurement obtained by aging 1000 1800 and a reactive organic compound having two or more functional groups capable of undergoing a condensation reaction with the hydrolysis condensate on a minute hydrolysis condensate having an inertia radius of 10 mm or less (provided that the main chain is substantially a vinyl polymer) A coating solution comprising a chain and a silyl group-containing vinyl polymer having at least one silicon atom in one molecule having a hydrolyzable group bonded to the terminal or side chain. Hydrolysis condensate according to claim 1 or 2, a coating liquid, wherein the one having the number of moles of 0.6 times or more hydroxy groups of alkoxy group.   The coating solution according to any one of claims 1 to 3, wherein the hydrolysis-condensation product has a weight average molecular weight of 1300 to 1800 in terms of standard polystyrene as measured by GPC.   The coating liquid according to any one of claims 1 to 4, wherein the reactive organic compound having two or more functional groups is a silane coupler. The coating liquid according to claim 5, wherein the silane coupler is selected from the following .

  The reactive organic compound having two or more functional groups is a polymer selected from the group consisting of alkyl alkoxy silicones or acrylic resins, epoxy resins, polyester resins, and urethane resins, and a carboxyl group, hydroxyl group, amino group The coating liquid according to claim 1, wherein the coating liquid has two or more functional groups selected from the group consisting of alkoxy groups and epoxy groups.   The coating liquid according to any one of claims 1 to 7, wherein 4 to 150 parts by weight of the reactive organic compound is blended with 100 parts by weight of the hydrolysis-condensation product.   The coating according to any one of claims 1 to 8, comprising a solvent selected from the group consisting of alcohols, glycol derivatives, hydrocarbons, esters, ketones and ethers, and a curing catalyst. liquid.   9. An alcohol selected from the group consisting of methanol, ethanol and isopropanol, and a curing catalyst selected from the group consisting of acetic acid, maleic acid, oxalic acid and fumaric acid. The coating liquid as described in 1.   Contains a minute hydrolysis condensate having an inertia radius of 10 mm or less, obtained by hydrolyzing tetramethoxysilane or its oligomer with the addition of water in an amount that is theoretically 100% hydrolytically condensable. The coating liquid formed by mix | blending the reactive organic compound which has 2 or more of functional groups which can be condensation-reacted with this hydrolysis-condensation product chosen from the following in the hydrolysis-condensation liquid to perform.
  Reactive organic compound: a polymer selected from the group consisting of acrylic resin, epoxy resin, polyester resin and urethane resin, and selected from the group consisting of carboxyl group, hydroxyl group, amino group, alkoxy group and epoxy group One having two or more functional groups (in this case, silyl having at least one silicon atom in one molecule in which the main chain is substantially composed of a vinyl polymer chain and a hydrolyzable group is bonded to the terminal or side chain) Excluding group-containing vinyl polymers
)   The coating liquid according to claim 11, wherein 4 to 150 parts by weight of the reactive organic compound is blended with 100 parts by weight of the hydrolyzed condensate.   The coating liquid according to claim 11 or 12, comprising a solvent selected from the group consisting of alcohols, glycol derivatives, hydrocarbons, esters, ketones and ethers, and a curing catalyst.   The alcohol according to claim 11 or 12, comprising an alcohol selected from the group consisting of methanol, ethanol and isopropanol, and a curing catalyst selected from the group consisting of acetic acid, maleic acid, oxalic acid and fumaric acid. Coating liquid. The coating solution according to any one of claims 1 to 14 is applied to a substrate, a transparent coating film formed by hardening. SiO obtained by applying the coating liquid according to any one of claims 1 to 14 on a substrate and curing it. ₂   10-80% by weight transparent coating film.

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