JP4522579B2 - COMPOSITE, SUBSTRATE COATED WITH COATED COMPOSITION COMPRISING THE COMPOSITE, AND METHOD FOR PRODUCING SUBSTRATE WITH COATED - Google Patents

Description

【００７５】
（式[I]中、Ｒ¹〜Ｒ⁶は、それぞれ独立に、水素原子；炭素数１〜１５，好ましくは１〜１０であり、直鎖状でも分岐状でもよいアルキル基；アリール基を示す。ｎは１〜１００の整数を示す。）
このような硬化性ポリシロキサン無機ポリマー[I]の重量平均分子量（Ｍｗ）は、通常、１００〜２００００、好ましくは２００〜１００００であることが望ましい。
【００７６】
また、架橋性反応基が水酸基の場合には、水酸基価が１〜２００mgKOH／ｇ、好ましくは２０〜１４０mgKOH／ｇの範囲にあるのが望ましく、この水酸基価が１mgKOH／ｇ未満では架橋が不十分で物性が低下するし、２００mgKOH／ｇを超えると架橋密度が高くなりすぎて可とう性が低下する傾向がみられる。
上記アルキル基としては、メチル基、エチル基、ｎ，ｉ−プロピル基、ｎ，ｉ，ｔ−ブチル基等が挙げられる。アリール基としては、フェニル基、ナフチル基等が挙げられる。
【００７７】
式[I]で表される硬化性ポリシロキサン無機ポリマーとして、具体的には、ポリヒドロキシシロキサン、ポリメトキシシロキサン、ポリエトキシシロキサン、ポリブトキシシロキサンなどが挙げられ、これらは１種または２種以上組み合わせて用いてもよい。
前記硬化性ポリシロキサン無機ポリマー[I]を含有する塗料には、必要に応じ、該硬化性オルガノポリシロキサンと架橋を形成しうる化合物を含有することができる。この架橋を形成しうる化合物としては、例えば水酸基含有化合物、アミノ樹脂、ポリイソシアネート化合物、ブロックイソシアネート化合物、エポキシ樹脂などを用いることができる。
【００７８】
このような硬化性ポリシロキサン無機ポリマー[I]と架橋を形成しうる化合物として具体的には、例えば、特開平７−６０１８４号公報［００１６］〜［００１９］欄に記載のものが挙げられる。
本発明では、上記成分（Ｂ−０）すなわち、式[I]で表される硬化性ポリシロキサン無機ポリマー[I]に代えて、無機系塗膜形成成分（Ｂ）すなわち、前記「オルガノシロキサン(イ)、その部分加水分解縮合物(ロ)または硬化性オルガノポリシロキサン(ハ)（これらをまとめて、オルガノシロキサン系化合物（Ｂ）等とも言う。）」が好ましく用いられる。
【００７９】
これら成分(イ)〜(ハ)のうちで、オルガノシロキサン(イ)としては、特開２０００−１８６２５０号公報［００２１］〜［００２４］欄に記載の加水分解性の有機シラン化合物またはその加水分解物などを用いることができる。
オルガノシロキサン ( イ ) またはその部分加水分解縮合物 ( ロ )
このオルガノシロキサン（加水分解性の有機シラン化合物、アルコキシシラン、オルガノシランなどとも言う。）(イ)は、
式［II］：Ｒ¹⁰ _nＳｉＸ_4-n・・・・・［II］
（式［II］中、Ｒ¹⁰は同一または異種の１価の置換または非置換の炭素数１〜８の炭化水素基を示し、ｎは０〜３の整数、Ｘは加水分解性基を示す。）で表される。
【００８０】
上記式［II］中、Ｒ¹⁰は炭素数１〜８の置換または非置換の１価の炭化水素基を示し、該置換基としては、ハロゲン基、グリシドキシ基、メルカプト基、エポキシ基、アミノ基等が挙げられる。
このような炭化水素基としては、例えば、メチル基、エチル基、ｎ，ｉ−プロピル基、ｎ，ｉ，ｔ−ブチル基などのアルキル基；フェニル基などのアリール基；シクロペンチル基、シクロヘキシル基などのシクロアルキル基；その他にビニル基、クロロメチル基、γ−クロロプロピル基、３，３，３−トリフルオロプロピル基、γ−メタクリロキシプロピル基、γ−グリシドキシプロピル基、γ−メルカプトプロピル基、３，４−エポキシシクロヘキシルメチル基、γ−アミノプロピル基などが挙げられる。
【００８１】
加水分解性基Ｘとしては、炭素数が１〜１０、好ましくは１〜５の範囲にある、アルコキシ基、アセトキシ基、オキシム基、アミノキシ基などが挙げられるが、入手のしやすさからアルコキシ基が好ましい。
式中ｎは官能基数を示し、ｎが０〜３に対応して単官能、２官能、３官能、４官能の各官能性のオルガノシロキサン（アルコキシシラン類）［II］の具体例としては以下のようなものが挙げられる。
【００８２】
すなわち、ｎ＝０の場合、テトラメトキシシラン、テトラエトキシシラン、テトラプロポキシシラン、テトラブトキシシランなどを挙げることができる。
ｎ＝１の場合、メチルトリメトキシシラン、メチルトリエトキシシラン、エチルトリメトキシシラン、エチルトリエトキシシラン、プロピルトリメトキシシラン、プロピルトリエトキシシラン、γ−クロロプロピルトリメトキシシラン、γ−クロロプロピルトリエトキシシラン、γ−グリシドキシプロピルトリメトキシシラン、γ−グリシドキシプロピルトリエトキシシラン、γ−メルカプトプロピルトリメトキシシラン、γ−メルカプトプロピルトリエトキシシラン、γ−メタクリロキシプロピルトリメトキシシラン、γ−メタクリロキシ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、フェニルトリメトキシシラン、フェニルトリエトキシシランなどを挙げることができる。
【００８３】
また、ｎ＝２の場合、ジメチルジメトキシシラン、ジメチルジエトキシシラン、ジフェニルジメトキシシラン、ジフェニルジエトキシシラン、γ−グリシドキシプロピルメチルジメトキシシラン、γ−グリシドキシプロピルメチルジエトキシシラン、γ−メタクリロキシプロビルメチルジメトキシシラン、γ−メタクリロキシプロピルメチルジエトキシシラン、γ−アミノプロピルメチルジメトキシシラン、γ−アミノプロピルメチルジエトキシシランなどを挙げることができる。
【００８４】
また、ｎ＝３の場合、トリメチルメトキシシラン、トリメチルエトキシシラン、トリメチルイソプロポキシシラン、ジメチルイソブチルメトキシシランなどを挙げることができる。
以上のオルガノシロキサン（アルコキシシラン類）の中でも、入手のしやすさから、テトラメトキシシラン、テトラエトキシシラン、テトラプロポキシシラン、テトラブトキシシラン、メチルトリメトキシシラン、メチルトリエトキシシラン、γ−グリシドキシプロピルトリメトキシシラン、γ−グリシドキシプロピルトリエトキシシラン、γ−メルカプトプロピルトリメトキシシラン、γ−メルカプトプロピルトリエトキシシラン、ジメチルジメトキシシラン、ジメチルジエトキシシラン、γ−グリシドキシプロピルメチルジメトキシシラン、γ−グリシドキシプロピルメチルジエトキシシランなどが好適に用いられる。
【００８５】
これらのオルガノシロキサン（アルコキシシラン）は１種または２種以上を組み合わせて用いてもよい。
上記オルガノシロキサン(イ)の部分加水分解縮合物(ロ)は、上記式［II］において、（４−ｎ）の加水分解性基Ｘのうち、１〜ｎ個が加水分解され、水酸基（−ＯＨ）になって生じた部分加水分解物が、さらに、平均１〜３個程度、脱水縮合しシロキサン結合にて連結を形成したものである。部分加水分解縮合物(ロ)の数平均分子量（Ｍｎ）は、通常、１００〜２０００、好ましくは２００〜１０００程度である。
【００８６】
硬化性ポリオルガノシロキサン ( ハ )
硬化性ポリオルガノシロキサン（硬化性オルガノポリシロキサン）(ハ)は、
平均組成式[III]：Ｒ²⁰ _aＳｉ（ＯＨ）_bＯ_(4-a-b)/2・・・・・[III]
（式[III]中、Ｒ²⁰は、Ｒ¹⁰と同様に、同一または異種の１価の置換または非置換の炭素数１〜８の炭化水素基を示し、ａ、ｂは、それぞれ、０．２≦ａ≦２、０．０００１≦ｂ≦３、ａ＋ｂ＜４の関係を満たす数である。）
で表され、分子中にシラノール基（≡Ｓｉ−ＯＨ）を含有するポリオルガノシロキサン[III]である。
【００８７】
硬化性オルガノポリシロキサン(ハ)は、シラノール基含有ポリオルガノシロキサンであり、硬化反応に預かる官能性基としての加水分解基を有するベースポリマーである前記オルガノシロキサン(イ)成分と縮合反応して硬化皮膜中に３次元架橋を形成するための架橋剤としての役割も有しており、前記オルガノシロキサン(イ)成分の硬化収縮による歪みを吸収してクラック発生を防止する効果のある成分である。
【００８８】
この硬化性オルガノポリシロキサン(ハ)、すなわち、シラノール基含有ポリオルガノシロキサン(ハ)を表す前記平均組成式[III]中のＲ²⁰としては、特に限定されず、前記式［II］中のＲ¹⁰と同じものが例示されるが、好ましくは、炭素数１〜４のアルキル基、フェニル基、ビニル基、ｒ−グリシドキシプロピル基、ｒ−メタクリロキシプロピル基、ｒ−アミノプロピル基、３，３，３−トリフルオロプロピル基等の置換炭化水素基、より好ましくはメチル基およびフェニル基である。前記[III]中のａおよびｂはそれぞれ前記の関係を満たす数であり、ａおよびｂが３を超えると、低温硬化性無機塗料にクラックを生じることがあり、またａが２を超えかつ４以下の場合またはｂが０．０００１未満では硬化がうまく進行しないことがある。
【００８９】
このような硬化性オルガノポリシロキサン(ハ)としては、特に限定されるわけではないが、例えばメチルトリクロロシラン、ジメチルジクロロシラン、フェニルトリクロロシラン、ジフェニルジクロロシラン、もしくは、これらに対応するアルコキシシランの１種もしくは２種以上の混合物を公知の方法により多量の水で加水分解することにより得ることができる。
【００９０】
硬化性ポリオルガノシロキサン(ハ)の製造に際して、アルコキシシランを公知の方法で加水分解した場合に、加水分解されずに一部アルコキシ基が微量に残る場合がある。すなわち、シラノール基とごく微量のアルコキシ基が共存するようなポリオルガノシロキサンが得られることがあるが、本発明においてはこのようなポリオルガノシロキサンを用いても差し支えない。
【００９１】
このような硬化性オルガノポリシロキサン[III]の重量平均分子量（Ｍｗ）は、通常、１００〜２００００、好ましくは３００〜１００００であることが望ましい。
本発明においては、前記式[I]で表される硬化性ポリシロキサン無機ポリマー（Ｂ−０）あるいは無機系塗膜形成成分としてのオルガノシロキサン系化合物（Ｂ）等は、中間塗膜（II）用の着色顔料含有硬化性ポリシロキサン系無機塗料組成物（着色塗料）中に、全縮合化合物換算固形分（固形分換算とも言う）で、通常１０〜８０重量％、好ましくは２０〜７０重量％の量で含まれていることが望ましい。該成分（Ｂ−０）あるいは（Ｂ）が、この着色塗料中に上記量で含まれていると、塗膜物性、耐久性、防食性が優れる傾向がある。
【００９２】
本発明においては、上記オルガノシロキサン系化合物すなわち無機系塗膜形成成分（Ｂ）１００重量部中に、式［II］で示されるオルガノシラン(イ)またはその部分加水分解縮合物(ロ)、および式[III]で示される硬化性オルガノポリシロキサン(ハ)は、任意量比で含まれていてもよい。
これら無機系塗膜形成成分（Ｂ）は、この中間塗膜（II）用の着色塗料中に、通常、１０〜８０重量％、好ましくは２０〜７０重量％となるような量で用いられる。
【００９３】
＜上記（Ｂ−０）あるいは（Ｂ）成分用の硬化用触媒（Ｃ）＞
上記成分（Ｂ）用の硬化用触媒（Ｃ）としては、特に限定はされないが、例えばカルボン酸金属塩、アミン類、酸類、アルカリ触媒、チタニウム化合物、ハロゲン化シラン類などが使用でき、例えばアルキルチタン酸塩、オクチル酸錫、ジブチル錫ラウリレート等のカルボン酸金属塩類；
ジブチルアミン−２−ヘキソエート、ジメチルアミンアセテート等のアミン塩類；
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等のアミン系シランカップリング剤；
ｐ−トルエンスルホン酸、フタル酸、塩酸等の酸類等が用いられる。
【００９４】
該触媒（Ｃ）の作用により、上記式[I]、［II］、[III]中の加水分解性基は加水分解され、生じたシラノール基（≡Ｓｉ−ＯＨ）が脱水縮合してシロキサン結合（Ｓｉ−Ｏ−Ｓｉ）が生じて着色塗料（着色顔料含有硬化性ポリシロキサン系無機塗料組成物）は固化すると考えられる。
これら触媒（Ｃ）は、この中間塗膜（II）用の着色塗料中に、通常、０．００１〜１０重量％、好ましくは０．００５〜５重量％となるような量で、また成分（Ｂ−０）好ましくは成分（Ｂ）１００重量部に対して、通常０．００１〜５重量部、好ましくは０．００５〜２重量部の量で用いられる。
【００９５】
＜着色顔料含有硬化性ポリシロキサン系
無機塗料組成物（着色塗料）の製造及び硬化＞
このような中間塗膜（II）用の着色塗料（着色顔料含有硬化性ポリシロキサン系無機塗料組成物）を製造するには、下記のようにすればよい。
すなわち、
(a)：上記式［II］すなわち、
式［II］：Ｒ¹⁰ _nＳｉＸ_4-n・・・・・［II］
（式［II］中、Ｒ¹⁰は同一または異種の１価の置換または非置換の炭素数１〜８の炭化水素基を示し、ｎは０〜３の整数、Ｘは加水分解性基を示す。）
で表される加水分解性オルガノシラン［II］を、有機溶媒または水に分散させてなるコロイダルシリカ中で、加水分解性基Ｘを１モルに対して、水０．００１〜５モル、好ましくは０．０１〜３モルの量で使用して、上記加水分解性オルガノシラン［II］を部分的に加水分解・重縮合してなるオルガノシランのシリカ分散オリゴマー溶液と、
(b)：平均組成式[III]：Ｒ²⁰ _aＳｉ（ＯＨ）_bＯ_(4-a-b)/2・・・・・[III]
（式[III]中、Ｒ²⁰は、Ｒ¹⁰と同様に、同一または異種の１価の置換または非置換の炭素数１〜８の炭化水素基を示し、ａ、ｂは、それぞれ、０．２≦ａ≦２、０．０００１≦ｂ≦３、ａ＋ｂ＜４の関係を満たす数である。）
で表され、分子中にシラノール基（≡Ｓｉ−ＯＨ）を含有するポリオルガノシロキサン[III]と、
のうちの何れか（すなわち(a)と(b)の何れか）を単独で用いても良いが、本発明では、上記(a)と(b)の両者を混合（配合）して用いることが望ましい。
【００９６】
(c)：この着色塗料には、必要により硬化用触媒（Ｃ）を配合してもよい。
また、必要により用いられる硬化用触媒（Ｃ）、すなわち、上記加水分解・重縮合用の触媒（Ｃ）は、通常、シリカ分散オリゴマー溶液(a)と、ポリオルガノシロキサン(b)とを上記のように混合する際に添加される。
なお、硬化用触媒（Ｃ）は、上記「オルガノシランのシリカ分散オリゴマー溶液」(a)調製の際に添加してもよく、あるいはポリオルガノシロキサン(b)に添加してもよく、また(a)と(b)とを配合して得られた混合物に添加してもよい。
【００９７】
硬化用触媒（Ｃ）の添加・混合は、ポリオルガノシロキサンオイル(b)の安定性などを低下させる恐れがあるため、使用直前に行うことが望ましい。言い換えると、下塗塗膜（I）表面へ中間塗膜（II）を形成する際に、(a)、(b)と（Ｃ）とを混合することが望ましい。
しかも、本発明では、(d)：上記シリカ分散オリゴマー溶液のコロイダルシリカは、シリカを固形分として５〜９５重量％、好ましくは１０〜９０重量％含有していることが好ましい。
【００９８】
また、上記加水分解性オルガノシラン［II］の少なくとも５０モル％、好ましくは５０〜９０モル％が、前記式［II］で表される加水分解性オルガノシラン［II］において、ｎ＝１のオルガノシランであることが望ましい。
本発明においては、さらに、(e)：上記シリカ分散オリゴマー溶液(a)と、上記ポリオルガノシロキサン(b)との合計を１００重量部とするとき、(a)と(b)の両者は、任意の量比で用いることができるが、通常、シリカ分散オリゴマー溶液(a)を１〜９９重量部、好ましくは５〜９５重量部の量で用い、また、上記ポリオルガノシロキサン(b)を残部量、すなわち、９９〜１重量部、好ましくは９５〜５重量部の量で用いることが望ましい。
【００９９】
着色顔料（Ａ）の添加・混合時期は、特に限定されないが、使用直前に添加し、該着色顔料（Ａ）が良好に分散した状態で塗料を使用することが望ましい。
＜任意成分＞
本発明においては、上記中間塗膜（II）形成用の着色顔料含有硬化性ポリシロキサン系無機塗料組成物（着色塗料）には、上記着色顔料（Ａ）、塗膜形成成分成分（Ｂ）および必要により用いられるその硬化用触媒（Ｃ）以外に、本発明の目的に反しない範囲で下記のようなその他の成分、例えば、下記トップコート塗膜(III)形成用の光触媒含有無機塗料に配合される硬化塗膜活性化用光触媒（Ｄ）、シリコーン（メタ）アクリート共重合体（Ｅ）およびその硬化用触媒、無機系バインダー（Ｆ）、溶剤、可塑剤、体質顔料、ブロッキング防止剤、離型剤、耐候性安定剤、滑剤、耐熱安定剤、難燃剤、充填剤、分散剤、消泡剤、レベリング剤、沈降防止剤、増粘剤、脱水剤、界面活性剤、シランカップリング剤等を添加することができる。
【０１００】
なお、この硬化塗膜活性化用光触媒（Ｄ）の添加・配合時期は特に限定されない。
この着色塗料が以下に詳述するシリコーン（メタ）アクリレート共重合体（Ｅ）を含む場合には、この共重合体（Ｅ）は、固形分換算で、上記（Ａ）、（Ｂ）、（Ｃ）、（Ｅ）の合計１００重量部中に、通常０〜５０重量部、好ましくは０〜４０重量部の量で、
また着色塗料中に、通常０〜３０重量％、好ましくは０〜１０重量％の量で含まれることが望ましい。
【０１０１】
上記量で成分（Ｅ）が含まれていると、付着性、塗膜物性、塗装作業性が良くなる傾向がある。
上記無機バインダー（Ｆ）としては、オルガノシリカゾルの加水分解物、オルガノシリカゾルの加水分解物とコロイダルシリカとの反応物等が挙げられる。
この着色塗料が無機系バインダー（Ｆ）を含む場合には、無機系バインダー（Ｆ）は、上記（Ａ）、（Ｂ）、（Ｃ）、（Ｅ）、（Ｆ）の合計１００重量部中に、通常０．１〜６０重量部、好ましくは０．５〜３０重量部の量で、
また、中間塗膜（II）用の着色塗料中に、通常、０．１〜４０重量％ 、好ましくは０．５〜３０重量％の量で含まれていてもよい。
【０１０２】
このような中間塗膜（II）形成用の着色塗料を得るには、上記各成分を配合し、混合等すればよい。
次に、この中間塗膜（II）形成用の着色塗料、後述するトップコート塗膜(III)形成用の光触媒含有無機塗料に配合してもよいシリコーン（メタ）アクリート共重合体（Ｅ）およびその硬化用触媒について詳説する。
【０１０３】
シリコーン（メタ）アクリート共重合体（Ｅ）および硬化用触媒
＜シリコーン（メタ）アクリート共重合体（Ｅ）＞
このシリコーン（メタ）アクリート共重合体（Ｅ）を硬化させる際には、その好ましい態様においては、後述する硬化用触媒（硬化触媒）が用いられる。
未硬化の該シリコーン（メタ）アクリート共重合体（アクリルシリコーン樹脂）（Ｅ）は、後述する硬化用触媒、例えば、酸または有機金属触媒の存在下に、常温で湿気硬化可能であり、一液型化可能な塗料用樹脂として用いられている。
【０１０４】
シリコーン（メタ）アクリート共重合体（Ｅ）としては、従来より公知のものを広く用いることができ、例えば、(a3-1)：シラノール基（≡Ｓｉ−ＯＨ）および加水分解性シリル基のうちの何れか一方または両者と、ラジカル重合性不飽和基（例：炭素・炭素二重結合（Ｃ＝Ｃ））とを含有する有機アルコキシシランと、
(b3-1)：（メタ）アクリル酸、（メタ）アクリル酸誘導体などのような、上記有機アルコキシシラン(a3-1)と共重合可能な「ビニル系モノマー」とを
ラジカル重合してなる共重合体（アクリルシリコーン樹脂）が挙げられる。
【０１０５】
上記ラジカル重合性有機アルコキシシラン(a3-1)としては、シラノール基および加水分解性シリル基のうちの何れか一方または両者と、重合性炭素・炭素２重結合とを含有しており、特開平１１−２７９４８０号公報［００３２］〜［００４５］欄に記載されている、以下に示すようなモノマーが挙げられる。
すなわち、重合性２重結合及び、炭素原子に結合したシラノール基または加水分解シリル基を含有する上記有機アルコキシシラン(a3-1)（以下、モノマー（Ａ−１）という）としては、例えば、下記式（３）で表され、具体的には例えば、式（３−１）〜（３−１１）に示すようなもの；
下記式（４）で表され、具体的には例えば、式（４−１）〜（４−９）に示すようなもの；
などが挙げられる。
【０１０６】
【化２】

【０１０７】
（式（３）中、Ｒ¹は、水素原子又は炭素数１〜１０のアルキル基を表す。Ｒ²は、水素原子、炭素数１〜１０のアルキル基、炭素数６〜１０のアリール基及び炭素数７〜１０のアラルキル基からなる群より選択された１価の基を表す。Ｒ¹ 又はＲ² が複数存在する場合には、同一であっても異なっていてもよい。Ｒ⁵ は、水素原子又はメチル基を表す。ａは、０〜２の整数を表す。）
【０１０８】
【化３】

【０１０９】
また、上記モノマー（Ａ−１）としては、下記式（４）で表され、具体的には式（４−１）〜（４−９）に示すようなものが挙げられる。
【０１１０】
【化４】

【０１１１】
（式（４）中、Ｒ¹ 、Ｒ² 、Ｒ⁵ 、ａは、上記と同じ。ｎは、１〜１２の整数である。）
【０１１２】
【化５】

【０１１３】
上記有機アルコキシシラン(a3-1)と共重合可能なビニル系モノマー(b3-1)としては、特開平１１−２７９４８０号公報［００４９］〜［００５０］欄に記載の（メタ）アクリル酸および／またはその誘導体などが挙げられる。
該ビニル系モノマー(b3-1)としては、ヒドロキシル基、ハロゲン基等でアルキル基中の水素原子の一部が置換されていてもよい（メタ）アクリル酸のアルキルエステルや、アミド等が挙げられ、
具体的には、例えば、メチル（メタ）アクリレート、エチル（メタ）アクリレート、ｎ−ブチル（メタ）アクリレート、イソブチル（メタ）アクリレート、ｔｅｒｔ−ブチル（メタ）アクリレート、オクチル（メタ）アクリレート、２−エチルヘキシル（メタ）アクリレート、デシル（メタ）アクリレート、ラウリル（メタ）アクリレート、パルミトイル（メタ）アクリレート、ステアリル（メタ）アクリレート、オクタデカノイル（メタ）アクリレート、オレイル（メタ）アクリレート、イコサノイル（メタ）アクリレート、
ベンジル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、
トリフルオロエチル（メタ）アクリレート、ペンタフルオロプロピル（メタ）アクリレート、パーフルオロシクロヘキシル（メタ）アクリレート、（メタ）アクリロニトリル、グリシジル（メタ）アクリレート、ジメチルアミノエチル（メタ）アクリレート、ジエチルアミノエチル（メタ）アクリレート、（メタ）アクリルアミド、α−エチル（メタ）アクリルアミド、Ｎ−ブトキシメチル（メタ）アクリルアミド、Ｎ，Ｎ−ジメチル（メタ）アクリルアミド、Ｎ−メチル（メタ）アクリルアミド（メタ）アクリロイルモルホリン、マクロモノマーである「ＡＳ−６、ＡＮ−６、ＡＡ−６、ＡＢ−６、ＡＫ−６」（商品名）等の化合物（東亜合成化学工業社製）、２−ヒドロキシエチル（メタ）アクリレート、２−ヒドロキシプロピル（メタ）アクリレート、２−ヒドロキシブチル（メタ）アクリレート、４−ヒドロキシブチル（メタ）アクリレート、２−ヒドロキシエチルビニルエーテル、Ｎ−メチロール（メタ）アクリルアミド、
４−ヒドロキシスチレンビニルトルエン、４−ヒドロキシスチレン、末端に水酸基を有するアクリル酸エステルオリゴマー、ポリプロピレングリコールメタクリレート、ポリエチレングリコールモノメタクリレート、ポリエチレングリコールポリプロピレングリコールメタクリレート、ポリプロピレングリコールモノアクリレート、ポリエチレングリコールモノアクリレート及びグリセロールモノメタクリレート、Ｎ−メチロール（メタ）アクリルアミド等の（メタ）アクリル酸のヒドロキシアルキルエステル類；水酸基含有化合物とε−カプロラクトンとの反応により得られるε−カプロラクトン変性ヒドロキシアルキルビニル系共重合体化合物（商品名「Ｐｌａｃｃｅｌ ＦＡ−１、ＦＡ―４、ＦＭ―１、ＦＭ―４」、ダイセル化学工業社製）、ポリカーボネート含有ビニル系化合物（商品名「ＨＥＡＣ−１」ダイセル化学工業社製）、（メタ）アクリル酸のヒドロキシアルキルエステル類とリン酸又はリン酸エステル類との縮合生成物等のリン酸エステル基含有（メタ）アクリル系化合物、ウレタン結合やシロキサン結合を含む（メタ）アクリレート等が挙げられる。
【０１１４】
その他に、スチレン、α−メチルスチレン、クロロスチレン、スチレンスルホン酸、４−ヒドロキシスチレン、ビニルトルエン等の芳香族炭化水素系ビニル化合物；マレイン酸、フマル酸、イタコン酸、（メタ）アクリル酸等の不飽和カルボン酸、これらのアルカリ金属塩、アンモニウム塩、アミン塩等の塩；無水マレイン酸等の不飽和カルボン酸の酸無水物、これら酸無水物と炭素数１〜２０の直鎖状若しくは分岐鎖を有するアルコール又はアミンとのジエステル若しくはハーフエステル等の不飽和カルボン酸のエステル；酢酸ビニル、プロピオン酸ビニル、ジアリルフタレート等のビニルエステルやアリル化合物；ビニルピリジン、アミノエチルビニルエーテル等のアミノ基含有ビニル系化合物；イタコン酸ジアミド、クロトン酸アミド、マレイン酸ジアミド、フマル酸ジアミド、Ｎ−ビニルピロリドン等のアミド基含有ビニル系化合物；２−ヒドロキシエチルビニルエーテル、メチルビニルエーテル、シクロヘキシルビニルエーテル、塩化ビニル、塩化ビニリデン、クロロプレン、プロピレン、ブタジエン、イソプレン、フルオロオレフィンマレイミド、Ｎ−ビニルイミダゾール、ビニルスルホン酸等のその他ビニル系化合物等が挙げられる。これらは単独で用いてもよく、２種以上併用してもよい。
【０１１５】
これらのモノマー（マクロモノマーを含む）は単独で用いてもよく、２種以上併用してもよい。
このような各種モノマーを共重合させるには、特開平１１−２７９４８０号公報［００５９］欄等に記載の方法に準拠し、アゾビスイソブチロニトリル（ＡＩＢＮ）等のアゾ系ラジカル重合開始剤の存在下に、必要により溶剤の存在下で、好ましくは上記加水分解性モノマーの加水分解を防止可能な非水系溶剤の存在下で、溶液重合等すればよい。該重合反応の際には、連鎖移動剤等を用いてもよい。上記非水系溶剤としては、トルエン、キシレン、ｎ−ヘキサン、シクロヘキサン等の炭化水素類；酢酸エステル類；ケトン類；アルコール類等が挙げられる。
【０１１６】
このように各種モノマーを共重合してなる硬化性シリコーン（メタ）アクリート共重合体（アクリルシリコーン樹脂）（Ｅ）は、
式（１）：
【０１１７】
【化６】

【０１１８】
（式（１）中、Ｒ¹ は、水素原子又は炭素数１〜１０のアルキル基を表し、Ｒ² は、水素原子、炭素数１〜１０のアルキル基、炭素数６〜１０のアリール基及び炭素数７〜１０のアラルキル基からなる群より選択された１価の基を表す。Ｒ¹ 又はＲ² が複数存在する場合には、同一であっても異なっていてもよい。ａは、０〜２の整数を表す。）で表される、炭素原子に結合したシラノール基（ヒドロキシシリル基）または加水分解性シリル基を少なくとも２個有するアクリル系共重合体である。
【０１１９】
このような硬化性シリコーン（メタ）アクリート共重合体（Ｅ）は、その数平均分子量（Ｍｎ）が通常、１０００から１８０００、好ましくは２００〜１５０００である。
また、水酸基価が１〜２００mgKOH／ｇ、好ましくは２０〜１４０mgKOH／ｇの範囲にあるのが望ましい。この水酸基価が上記範囲にあると、架橋密度が適度であり、可撓性などの物性も優れた複合体特に塗膜が得られる傾向がある。
【０１２０】
該硬化性シリコーン（メタ）アクリート共重合体は、Ｔｇが０〜１５０℃、好ましくは０〜１００℃の範囲にあるものが好適であり、Ｔｇがこのような範囲にあると、常温で液体、固体となり、塗料に使用しやすく、軟化点が適度であり取り扱い易く、塗装時のフロー性がよい。
＜硬化用触媒（ｂ3）＞
硬化性シリコーン（メタ）アクリート共重合体（Ｅ）の硬化用触媒（ｂ3）としては特に限定されず従来より公知のものを使用でき、例えば、特開平１１−２７９４８０号公報［００６５］〜［００６９］欄等に記載のものを使用できる。
【０１２１】
このような硬化用触媒（ｂ3）としては、例えば、有機カルボンと有機アミンとの併用物、有機リン酸エステル、有機金属系化合物等を挙げることができる。上記有機カルボン酸の具体例としては、蟻酸、酢酸、プロピオン酸、酪酸、ペンタン酸、ヘキサン酸、オクチル酸、２−エチルヘキサン酸、デカン酸、ドデカン酸、安息香酸、フタル酸、フマル酸、マレイン酸、コハク酸、イタコン酸及びこれらの無水物等が挙げられる。上記有機アミンの具体例としては、ラウリルアミン等の一級アミン、トリエチルアミン、ジメチルラウリルアミン等の三級アミン、モルホリン等の環状アミン等が挙げられる。上記有機カルボン酸と上記有機アミンとの組み合わせとしては、硬化活性とポットライフのバランスを考慮して、例えば、酢酸／ジメチルラウリルアミン、ヘキサン酸／ラウリルアミン、２−エチルヘキサン酸／ジメチルラウリルアミン、２−エチルヘキサン酸／ラウリルアミンの組み合わせが好ましい。
【０１２２】
上記有機リン酸エステルの具体例としては、ジ（２−エチルヘキシル）モノホスフェート、ジ（２−エチルヘキシル）ジホスフェート等がある。硬化活性とポットライフのバランスの観点から、ジ（２−エチルヘキシル）モノホスフェートが好ましく、この有機リン酸エステルは単独で用いても良く、上記有機アミンと併用しても良い。この場合、好ましい組み合わせとしてはジ（２−エチルヘキシル）モノホスフェート／ジメチルラウリルアミン、ジ（２−エチルヘキシル）モノホスフェート／ラウリルアミンであり、更に好ましくは、ジ（２−エチルヘキシル）モノホスフェート／ジメチルラウリルアミンである。上記組み合わせ物質は、１種類でも良く、２種類以上併用してもよい。
【０１２３】
上記有機金属系化合物としては、例えば、有機錫化合物、アルミキレート化合物等がある。上記有機錫化合物としては、例えば、ジオクチル錫ビス（２−エチルヘキシルマレート）、ジオクチル錫オキサイド又はジブチル錫オキサイドとシリケートとの縮合物、ジブチル錫ジオクトエート、ジブチル錫ジラウレート、ジブチル錫ジステアレート、ジブチル錫ジアセチルアセトナート、ジブチル錫ビス（エチルマレート）、ジブチル錫ビス（ブチルマレート）、ジブチル錫ビス（２−エチルヘキシルマレート）、ジブチル錫ビス（オレイルマレート）、スタナスオクトエート、ステアリン酸錫、ジ−ｎ−ブチル錫ラウレートオキサイド等が挙げられる。また、ジブチル錫ビスイソノニル−３−メルカプトプロピオネート、ジオクチル錫ビスイソノニル−３−メルカプトプロピオネート、オクチルブチル錫ビスイソノニル−３−メルカプトプロピオネート、ジブチル錫ビスイソオクチルチオグルコレート、ジオクチル錫ビスイソオクチルチオグルコレート、オクチルブチル錫ビスイソオクチルチオグルコレート等の分子内にイオウ原子を有する有機錫化合物を挙げることができる。
【０１２４】
上記アルミキレート化合物としては、エチルアセトアセテートアルミニウムジイソプロピレート、アルミニウムトリス（アセチルアセトナート）、アルミニウムトリス（エチルアセトアセテート）、アルミニウムモノアセチルアセトネートビス（エチルアセトナート）、アルキルアセチルアセテートアルミニウムジイソプロピレート等が挙げられる。これらのうちでは、アルミニウムトリス（エチルアセトアセテート）とアルミニウムトリス（アセチルアセトナート）がイソシアナートと配合した場合の貯蔵安定性及び可使時間のバランスが良好で、塗膜の接触角が小さくなるという点から好ましい。
【０１２５】
上記硬化用触媒は１種または２種以上併用してもよい。
本発明においては、上記硬化触媒（ｂ3）は、硬化性のシリコーン（メタ）アクリート共重合体（Ｅ）１００重量部に対して、通常、０．００１〜１０重量部、好ましくは０．０１〜８重量部の量で用いられる。このような量でシリコーン（メタ）アクリート共重合体（Ｅ）用の硬化用触媒（ｂ3）を用いると、該シリコーン（メタ）アクリート共重合体の加水分解性シリル基は効率よく加水分解されて、ヒドロキシシリル基となり、また架橋性反応基（ＯＨ）同士では脱水反応が起こりシロキサン結合（架橋）が効率よく形成されるものと考えられる。
【０１２６】
本発明では、このようなシリコーン（メタ）アクリート共重合体（Ｅ）、シリコーン（メタ）アクリート共重合体用硬化触媒（ｂ3）と共に、さらに、塗膜形成成分となる特開平１１−２７９４８０号公報［００６４］〜［００７７］欄に記載した上記以外のアルコキシシラン（２）および／またはその部分加水分解縮合物、同公報［００８０］欄に記載のシランカップリング剤（例：アミノシラン、エポキシシランおよびこれらの反応生成物）、加水分解性エステル化合物を用いてもよい。
【０１２７】
上記アルコキシシラン（２）としては、例えば、
下記式（２）で表されるものが挙げられる。
（Ｒ³ Ｏ）_4-b −Ｓｉ−（Ｒ⁴ ）_b ・・・・・（２）
（式（２）中、Ｒ³は、炭素数１〜１０のアルキル基、炭素数６〜１０のアリール基及び炭素数７〜１０のアラルキル基からなる群より選択された１価の炭化水素基を表す。Ｒ⁴は、炭素数１〜１０のアルキル基、炭素数６〜１０のアリール基及び炭素数７〜１０のアラルキル基からなる群より選択された１価の炭化水素基を表す。Ｒ³及び／又はＲ⁴が複数存在する場合には、同一であっても異なっていてもよい。ｂは、０〜２の整数を表す。）
上記アルコキシシラン（２）として、具体的には、例えば、テトラメチルシリケート、テトラエチルシリケート、テトラｎ−プロピルシリケート、テトラｉ−プロピルシリケート、テトラｎ−ブチルシリケート、テトラｉ−ブチルシリケート等のテトラアルキルシリケート；メチルトリメトキシシラン、メチルトリエトキシシラン、フェニルトリメトキシシラン、フェニルトリエトキシシラン、オクタデシルトリエトキシシラン、３−グリシドキシプロピルトリメトキシシラン、メチルトリｓｅｃ−オクチルオキシシラン、メチルトリフェノキシシラン、メチルトリイソプロポキシシラン、メチルトリブトキシシラン等が挙げられる。これらはシランカップリング剤としても機能する。
【０１２８】
＜中間塗膜（ II ）の形成法＞
このような着色塗料を塗装・硬化させて、下塗塗膜（I）表面に中間塗膜（II）を形成するには、その膜厚、配合組成などにも依るが、この着色塗料を、例えば、下塗塗膜（I）表面に塗装（塗布）し、あるいは型内に塗設された下塗塗膜（I）上に充填し、通常、３０〜２５０℃、好ましくは８０〜２００℃の温度に、０．０５〜３時間、好ましくは０．１〜１．５時間程度、該着色塗料を加熱するか、あるいは
常温下で１〜１２０時間、好ましくは５〜７２時間保持すればよく、このように加熱あるいは常温保持すれば硬化しゲル被膜が形成される。
【０１２９】
さらに詳説すると、本発明において、上記中間塗膜（II）を、上記のように被塗物基材表面に形成するには、静電吹き付け法、流動浸漬法、静電流動浸漬法、刷毛塗布、ロールコート法、フローコート法、エアースプレー吹きつけ法、エアレス吹きつけ法など従来より公知の方法により、着色塗料を被塗物基材に塗布し、次いで該着色塗料を常温乾燥させるか、必要により加熱し、硬化させることにより、均一膜状の中間塗膜（II）を形成することができる。
【０１３０】
上記塗装方法の中では静電吹きつけ法が好ましい。加熱硬化させる場合には、中間塗膜（II）形成用の着色塗料中に含まれる塗膜形成成分などの種類にもよるが、通常１４０〜２００℃で５〜４０分間が適当である。
このように硬化して得られる中間塗膜（II）では、用いられた無機系塗膜形成成分、シリコーン（メタ）アクリート共重合体などの間において、例えば、無機系塗膜形成成分中や、シリコーン（メタ）アクリート共重合体等に含まれているアルコキシシリル基などの加水分解で生じた水酸基（ＯＨ）間で脱水縮合が起こるなど、分子間架橋などが生じて着色塗料中の塗膜形成成分が硬化しているのであろうと考えられる。
【０１３１】
中間塗膜（II）の厚さは、平均膜厚で通常５〜１５０μｍ、好ましくは１０〜５０μｍの範囲で選ばれる。
［トップコート塗膜 (III) ］
トップコート塗膜(III)は、上記中間塗膜（II）上に設けられる。
このようなトップコート塗膜(III)は、中塗層となる上記中間塗膜（II）上に、光触媒含有硬化性ポリシロキサン系無機塗料組成物（光触媒含有無機塗料）を塗布し、通常、常乾あるいは加熱硬化、好ましくは加熱硬化して得られる。
【０１３２】
該光触媒含有無機塗料としては、上記中間塗膜（II）形成用の着色顔料含有硬化性ポリシロキサン系無機塗料組成物（着色塗料）に配合されるものと同様の無機系塗膜形成成分（Ｂ）および必要によりその硬化触媒（Ｃ）を含み、かつ「酸化チタンを主成分とする硬化塗膜活性化用光触媒（光触媒）」（Ｄ）を含むものが用いられる。
【０１３３】
すなわち、上塗層用の光触媒含有無機塗料としては、
（Ｄ）酸化チタンを主成分とする硬化塗膜活性化用光触媒（光触媒）と、
（Ｂ−０）硬化性ポリシロキサン無機ポリマーと、必要に応じて、
（Ｃ）上記（Ｂ−０）成分用の硬化用触媒と
を含有しているものを使用することができるが、その好ましい態様においては、
（Ｄ）酸化チタンを主成分とする硬化塗膜活性化用光触媒（光触媒）と、
（Ｂ）オルガノシロキサン(イ)、その部分加水分解縮合物(ロ)または硬化性オルガノポリシロキサン(ハ)と、必要に応じて、
（Ｃ）上記（Ｂ）成分用の硬化用触媒と
を含有しているものが使用される。
【０１３４】
すなわち、その好ましい態様においては、中間塗膜（II）用の着色塗料の場合と同様に、（Ｂ−０）硬化性ポリシロキサン無機ポリマーに代えて、好ましくは（Ｂ）「オルガノシロキサン(イ)、その部分加水分解縮合物(ロ)または硬化性オルガノポリシロキサン(ハ)」が使用される。
本発明の好ましい態様では、このように複合体の中塗層、上塗層共に、「オルガノシロキサン、その部分加水分解縮合物または硬化性オルガノポリシロキサン」（Ｂ）を、これら成分用の硬化用触媒の存在下に反応・硬化させてなるポリシロキサン無機ポリマーが含まれているので層間接着性に優れ、しかも光触媒による塗膜の分解作用に対する耐久性（抵抗性）に優れるのであろうと考えられる。
【０１３５】
この光触媒含有無機塗料には、下記硬化塗膜活性化用光触媒（Ｄ）、塗膜形成成分成分（Ｂ）および必要によりその硬化用触媒（Ｃ）以外に、本発明の目的に反しない範囲で下記のようなその他の成分、例えば、上記シリコーン（メタ）アクリート共重合体（Ｅ）およびその硬化用触媒、無機系バインダー（Ｆ）としてのオルガノシリカゾル、溶剤、可塑剤、着色顔料（Ａ）、体質顔料、ブロッキング防止剤、離型剤、耐候性安定剤、滑剤、耐熱安定剤、難燃剤、充填剤、レベリング剤、沈降防止剤、増粘剤、脱水剤、界面活性剤、シランカップリング剤等を添加することができる。
【０１３６】
このような光触媒含有無機塗料には、成分（Ｂ）と（Ｃ）と（Ｄ）と（Ｅ）との合計を１００重量部とするとき、
成分（Ｂ）（全縮合化合物固形分換算すなわち固形分換算。以下同様。）を２０〜８０重量部、好ましくは３０〜７０重量部の量で、
成分（Ｃ）を０〜１０重量部、好ましくは０．０１〜５重量部の量で、および
成分（Ｄ）を２０〜８０重量部、好ましくは３０〜７０重量部の量で、
成分（Ｅ）を０〜５０重量部、好ましくは０〜４０重量部の量で含有していることが望ましい。
【０１３７】
また、この光触媒含有無機塗料中には、上記成分（Ｂ）を０．０１〜５０重量％、好ましくは０．１〜３０重量％の量で、
成分（Ｃ）を０〜１０重量％、好ましくは０．０１〜５重量％の量で、および
成分（Ｄ）を０．０１〜５０重量％、好ましくは０．１〜３０重量％の量で、
成分（Ｅ）を０〜２０重量％、好ましくは０〜１０重量％の量で含有していることが望ましい（但し、該塗料中の全成分の合計を１００重量％とする。）。
【０１３８】
以下、該光触媒含有硬化性ポリシロキサン系無機塗料組成物（光触媒含有無機塗料）に含まれる硬化塗膜活性化用光触媒（Ｄ）などを中心に説明する。
＜硬化塗膜活性化用光触媒（Ｄ）＞
硬化塗膜活性化用光触媒（Ｄ）としては、該成分（Ｄ）中に、酸化チタン（ＴｉＯ₂）を主成分として、通常５０〜１００重量％、好ましくは７０〜１００重量％の量で含有するものが高光触媒活性、安全性等の点で好ましく使用される。
【０１３９】
このような酸化チタン量（ＰＷＣ（％））は、トップコート塗膜(III)中に含まれる酸化チタンと無機ポリマー（硬化物）との合計を１００重量％とするとき、通常１〜９９重量％、好ましくは２０〜８０重量％、さらに好ましくは３０〜７０重量％であることが望ましい。酸化チタンの配合量が上記範囲にあると、耐汚染性に優れ、耐久性、表面硬度、付着性などの塗膜物性に優れ、硬化時に塗膜にクラックが発生しない傾向がある。
【０１４０】
また、このような硬化塗膜活性化用光触媒（Ｄ）は、合計で２０〜８０重量％、好ましくは３０〜７０重量％の量で、硬化したトップコート塗膜(III)中に含まれていることが望ましい。
また、この硬化塗膜活性化用光触媒（Ｄ）は、用いられる光触媒含有無機塗料中に、通常、０．０１〜５０重量％、好ましくは０．１〜３０重量％の量で含まれていることが望ましい。
【０１４１】
上記硬化塗膜活性化用光触媒（Ｄ）には、上記酸化チタンの他、他の光触媒作用を有する物質が含まれていてもよく、これら硬化塗膜活性化用光触媒としては、特開平１１−１６５９号公報、特開２０００−４２４８０号公報等に記載のものを広く使用でき、各種金属の酸化物、硫化物等が挙げられ、各種金属の酸化物が好ましい。
【０１４２】
酸化物としては、例えば、酸化鉄、酸化タングステン、酸化ジルコニウム、酸化スズ、酸化ビスマス、酸化ルテニウム、酸化亜鉛、チタン酸ストロンチウム、酸化カドミウム、酸化インジウム、酸化銀、酸化マンガン、酸化銅、酸化バナジウムなど、各種金属カルコゲナイト（セレン、テルル化合物）など、およびこれらの混合物などが挙げられる。酸化チタンを含めて、硬化塗膜活性化用光触媒として用いられるこれらの物質には、表面に金属元素と酸素とが存在するので、表面水酸基を吸着しやすい性質を有する。
【０１４３】
硫化物としては、例えば、硫化カドミウム、硫化亜鉛、硫化銅、硫化モリブデン、硫化タングステン、硫化アンチモン、硫化ビスマスなどが挙げられる。
これらは単独で用いてもよく、２種以上を併用してもよい。
なかでも酸化チタン（二酸化チタン、ＴｉＯ₂）は、無害であり、化学的に安定であり、かつ、安価に入手可能である。
【０１４４】
上記酸化チタンについて詳説すると、本発明では該酸化チタンとしてはアナターゼ型、ルチル型、ブルカイト型のいずれをも用いることができ、光触媒活性の点で、アナターゼ型、ルチル型が好ましく、さらにはアナターゼ型が望ましい。ルチル型酸化チタンは、高温で焼結することができ、強度と耐摩耗性に優れた塗膜を得ることができるが、アナターゼ型酸化チタンは、極めて細かな粒子を分散させたゾルが市販されており、容易に入手することができ、かつ非常に薄い塗膜を容易に形成することができる利点がある。
【０１４５】
これら硬化塗膜活性用光触媒としては、その平均粒子径が、通常０．００１μｍ（１ｎｍ）〜１μｍ、好ましくは７ｎｍ〜２５０ｎｍ、さらに好ましくは７ｎｍ〜５０ｎｍ、特に好ましくは７ｎｍ〜２０ｎｍのものが好ましい。
しかも、このような粒子径の光触媒のうちでも、アナターゼ型二酸化チタン粒子が望ましい。しかも、このような粒子径の光触媒のうちでも、アナターゼ型二酸化チタン粒子が望ましい。
【０１４６】
なお、この光触媒活性用光触媒の平均粒子径が小さいほど、トップコート塗膜(III)の光触媒活性が強くなり、さらに透明性に優れた塗膜を得ることができるため、中間塗膜（中間層）（II）の着色性が発揮された積層塗膜を形成することができ、カラーバリエーションに富んだ塗膜を形成することができる。
一般にトップコート塗膜(III)の隠蔽性が低くなると、紫外線透過率が高くなり、長期的な暴露下においては、トップコート塗膜(III)中に含まれる光触媒による活性作用により、中間塗膜（中間層）(II)とトップコート塗膜（上塗層）(III)との間などで層間剥離を生ずることがあるが、本塗層系の場合、中間層(II)の無機成分が非常に高く設計されているため、トップコート塗膜(III)に含まれる光触媒活性作用に長期的に耐えうることができる。
【０１４７】
特に、対汚染性、耐久性、色、艶の安定性の観点から、上記平均粒子径の範囲のうちでも極力平均粒子径の小さなものを使用することが望ましい。
このような硬化塗膜活性光触媒としては、商品名「ＳＴ−０１」(石原テクノ(株)製)等が挙げられる。
また、このような粒子径の小さなものは、扱いやすいようにゾル状のものが市販されており、用途に応じて好適に使用することができる。
【０１４８】
このような硬化塗膜活性用光触媒ゾルとしては、商品名「ＳＴＳ−０１」(石原テクノ(株)製)、商品名「ＫＳ−２４７」(テイカ(株)製)が挙げられる。なお、色の安定性、物性改善等のためには、上記光触媒微粒子と、一般に塗料用として使用され、光活性がアナターゼ型に比較して少ないルチル型またはブルカイト型の顔料用酸化チタンと、光触媒の強いアナターゼ型の酸化チタンとを組み合わせて使用してもよい。
【０１４９】
なお、本発明においては、トップコート塗膜(III)には、これら硬化塗膜活性化用光触媒（Ｄ）と共に、光触媒機能をいっそう向上させ得る成分（第二成分）が含まれていてもよく、例えば、Ｖ，Ｆｅ，Ｃｏ，Ｎｉ，Ｃｕ，Ｚｎ，Ｒｕ，Ｒｈ，Ｐｄ，Ａｇ，Ｐｔ，Ａｕなどの金属および／または金属化合物が挙げられる。該金属化合物としては、例えば、酸化物、水酸化物、オキシ水酸化物、硫酸塩、ハロゲン化物、硝酸塩、さらに金属イオンなどが挙げられる。
【０１５０】
本発明においては、上記酸化チタンを単独で使用し、あるいは酸化チタンと他の光触媒物質とを併用しているので、後述する紫外線等の通常の光照射（例：波長４００ｎｍ以下）によって光励起されたときに、光触媒作用によって酸化チタンに電子−正孔対が生成し、この電子−正孔対に酸素分子や水分子が反応し、高酸化力のスーパーオキサイドイオン（超酸化物イオン）、過酸化水素、ヒドロキシルラジカルなどの活性酸素が生成し、この活性酸素によって、塗膜（特にトップコート塗膜(III)）の表面の有機系汚染物などは、酸化・分解されて脱落・飛散・死滅等するため、トップコート塗膜(III)表面の耐汚染性などが良好に保持されるのであろうと考えられる。
【０１５１】
このような硬化塗膜活性化用光触媒（Ｄ）を含有するトップコート塗膜(III)を有する本発明の複合体、特に硬化塗膜では、光照射すれば該硬化塗膜活性化用光触媒（Ｄ）は活性化され、例えば、特開２０００−４２４８０号公報［００１５］〜［００１６］段にも記載されているものと同様に、そのトップコート塗膜(III)側表面に、その膜の厚さが０.１μｍ程度の場合、例えば、日光(照度で２〜３ｍＷ/ｃｍ²程度）で２〜３時間照射すれば該硬化塗膜活性化用光触媒は、活性化され、耐汚染性等が発揮されるようになる。
【０１５２】
＜光触媒含有硬化性ポリシロキサン系無機塗料組成物の製造及び硬化＞
このような光触媒含有硬化性ポリシロキサン系無機塗料組成物（光触媒含有無機塗料）を製造するには、光触媒(D)を配合する点以外は、中間層（II）用の前記着色塗料の場合と同様にすればよいが、用いられる各無機成分それぞれに光触媒（Ｄ）などを添加・混入して使用することもできる。
【０１５３】
すなわち、本発明では、上塗層用の光触媒含有塗料は、
(a)：上記加水分解性オルガノシラン［II］を部分的に加水分解・重縮合してなるオルガノシランのシリカ分散オリゴマー溶液と、
(b)：上記ポリオルガノシロキサン[III]と、
の混合液に、硬化塗膜活性化用光触媒（Ｄ）、硬化用触媒（Ｃ）（加水分解・重縮合用の触媒（Ｃ））などを添加・混合して製造してもよく、また、
上記(a)と(b)のうちの何れかの無機成分（光触媒用バインダー）に、上記光触媒（Ｄ）、硬化触媒（Ｃ）などを添加・混合して光触媒含有無機塗料（(a)＋（Ｄ）＋（Ｃ）、(b)＋（Ｄ＋（Ｃ）））として用いることができる。
【０１５４】
換言すれば、本発明では、光触媒用無機バインダーとして、上記(a)と(b)とを混合して使用してもよく、また、上記(a)、(b)それぞれの無機成分を、光触媒用無機バインダーとしてそれぞれ単独で使用してもよい。
＜トップコート塗膜 (III) の形成法＞
このような光触媒含有無機塗料を塗装・硬化させて、中間塗膜（II）表面にトップコート塗膜(III)を形成するには、前記中間塗膜（II）の場合と同様にすればよい。すなわち、トップコート塗膜(III)の膜厚、光触媒含有無機塗料の配合組成などにも依るが、この光触媒含有無機塗料を、例えば、中間塗膜（II）表面に塗装（塗布）し、あるいは型内に塗設された中間塗膜（II）上に充填し、通常、３０〜２５０℃、好ましくは８０〜２００℃の温度に、０．０５〜３時間、好ましくは０．１〜１．５時間程度、該光触媒含有無機塗料を加熱するか、あるいは、常温下で１〜１２０時間、好ましくは５〜７２時間保持すればよく、このように加熱下あるいは常温下に該塗料を保持すれば硬化しゲル被膜が形成される。
【０１５５】
このようにして得られたトップコート塗膜(III)の平均膜厚は、通常、０．０１〜５０μｍ厚、好ましくは０．１〜２０μｍである。
【０１５６】
【発明の効果】
本発明に係る複合体、例えば、複合塗膜は、下塗塗膜（I）と中間塗膜（II）とトップコート塗膜(III)とが密着してなっており、着色顔料と硬化塗膜活性化用光触媒（光触媒）とを別々の層、すなわち着色顔料は中間層としての中間塗膜（II）に含有させ、光触媒は上塗層のトップコート塗膜(III)に含有させることが可能となっている。従って、本発明では、配合される着色顔料が有機系であっても光触媒作用を受けないため、有機系顔料なども退色することがなく、有機系、無機系の何れの着色料でも配合可能となる。また使用される着色顔料としては、光触媒作用への影響を考慮することなく淡色系から濃色系まで任意の色彩のものを自由に選択でき、着色顔料選択の幅が広がっている。また光触媒としても、基本的には、着色顔料とは別異の上塗層としてのトップコート塗膜(III)に配合されるため、中間塗膜（II）に配合されている着色顔料の影響を受けることなく耐汚染効果を十分に発揮できるなど、着色顔料と光触媒の各機能をそれぞれ十分に発揮させることが可能となっている。
【０１５７】
よって、係る複合塗膜を、その下塗塗膜（I）側が金属パネル、ガードレール、建築資材等のように汚れの激しい屋外用部材の基材表面と密着するように設ければ、膜厚性と防食性に優れ、かつ耐汚染性、耐久性、表面硬度に優れた塗膜を基材表面に形成できる。また、そのような優れた特性の複合体からなる塗膜で被覆された基材が提供される。
【０１５８】
本発明では、このような複合塗膜付き基材を製造するに際しては、金属、建築資材等の基材表面に、膜厚性と防食性に優れた下塗塗膜（I）用の粉体塗料（I）を塗装し、さらにその表面上に、耐久性、付着性、耐候性に優れた中間塗膜（II）用の着色顔料含有硬化性ポリシロキサン系無機塗料組成物（着色塗料）を塗装し、次いで、その表面に、耐汚染性、耐久性、表面硬度に優れた光触媒含有硬化性ポリシロキサン系無機塗料組成物（光触媒含有無機塗料）の塗装を施すことにより、膜厚性と防食性に優れかつ耐汚染性、耐久性、表面硬度にも優れ、これら特性がバランス良く優れた複合塗膜を基材表面に形成している。
【０１５９】
【実施例】
以下、本発明について実施例に基づきさらに具体的に説明するが、本発明はこれら実施例に何等限定されるものではない。
以下の実施例、比較例で用いた各成分及びその製法、各試験方法等は、以下の通り。
【０１６０】
（エポキシ樹脂系粉体塗料の製造方法）
第１表に示す種類と量の各成分をドライブレンダー［アイチ電気（株）製、商品名：ドッキングミキサー］にて約１分間均一に混合した後、押し出し混練機［プリズム（株）製、商品名：２軸混練機］を用い、８０〜１００℃で溶融混練し、冷却後ハンマー式衝撃粉砕機で微粉砕した。次いで１０６ミクロンの空隙のメッシュ金網で処理し、通過分を分取し、下塗り用熱硬化性エポキシ系粉体塗料を得た。
【０１６１】
（着色顔料含有硬化性ポリシロキサン系無機塗料組成物）
＜無機ポリマーの物性、製法＞
(i)オルガノシロキサン（イ）またはその部分加水分解縮合物（ロ）の合成
［オルガノシロキサンの部分加水分解縮合物（ロ）−▲１▼］
攪拌機、加温ジャケット、コンデンサー及び温度計をつけたフラスコ中に、テトラエトキシシラン３０部とメチルトリメトキシシラン３０部と水５部とIPA（イソプロピルアルコール）３５部を添加して攪拌しながら６０℃で約５時間かけて加水分解反応を行った後、冷却することにより、オルガノシランの部分加水分解縮合物「（ロ）−▲１▼」を得た。この縮合物の全縮合化合物換算固形分は３２％であった。
【０１６２】
［オルガノシロキサンの部分加水分解縮合物（ロ）―▲２▼］
攪拌機、加温ジャケット、コンデンサー及び温度計をつけたフラスコ中に、IPA分散コロイダルシリカゾル「ＩＰＡ−ＳＴ」（粒子径１０〜２０nm、固形分３０％、水分０．５％、日産化学工業（株）製）１００部とメチルトリメトキシシラン６８部と水０．８部とを投入し、攪拌しながら６５℃で約５時間かけて加水分解反応を行った後、冷却することにより、オルガノシラン部分加水分解縮合物「（ロ）―▲２▼」を得た。この縮合物は、室温で４８時間放置した時の全縮合化合物換算固形分は３６％であった。
【０１６３】
(ii)硬化性オルガノポリシロキサン（ハ）の合成
攪拌機、加温ジャケット、コンデンサー、滴下ロート及び温度計を取り付けたフラスコに、メチルトリイソプロポキシシラン２３０部（１モル）がトルエン１４０部に溶解されてなる溶液を仕込み、これに、１％塩酸水溶液１０８部を２０分かけて滴下しメチルトリイソプロポキシシランを攪拌下６０℃で加水分解した。滴下終了から４０分後に攪拌を止め、反応液を分液ロート移しいれて静置したところ、二層に分離した。
【０１６４】
少量の塩酸を含んだ下層の水とイソプロピルアルコールの混合液を分液除去し、後に残ったトルエンの樹脂溶液中に残存している塩酸を水洗で除去し、更にトルエンを減圧除去した後、残留物をイソプロピルアルコールで希釈することにより、平均分子量（Ｍｗ）約２０００のシラノール基含有オルガノポリシロキサン（硬化性オルガノポリシロキサン）（ハ）のイソプロピルアルコール溶液を得た。
【０１６５】
この溶液の全縮合化合物換算固形分は、４０％である。
また、この溶液中の硬化性ポリオルガノシロキサン（ハ）は、前記平均組成式（III）を満たすことが確認されている。
＜着色顔料＞
ルチル型酸化チタン（白）（平均粒径：２００nm）
＜中塗用着色塗料の製法＞
上記に示した製法で合成したオルガノシロキサンの部分加水分解縮合物（ロ）と硬化性ポリオルガノシロキサン（ハ）と触媒とを所定の比で混合し、安定化させた後、所定量の分散剤、溶剤、顔料を混入した後、ディスパーサーを用いて、混合攪拌した。
【０１６６】
この溶液を、メッシュを用いて取り出した後、横型のジルコニアベッセルミル（浅田鉄鋼株式会社製）を用いて、１次粒子径まで着色顔料を均一に分散さることにより、光触媒含有硬化性ポリシロキサン系無機塗料組成物を調製した。
（光触媒含有硬化性ポリシロキサン系無機塗料組成物）
＜無機ポリマーの製法＞
無機ポリマーは、上記着色顔料含有硬化性ポリシロキサン系無機塗料組成物に用いる場合の無機ポリマーの製法と同様な方法で調製した。
【０１６７】
＜光触媒の種類＞
（ａ）光触媒Ａ：光触媒酸化チタンゾル（固形分３０％）
結晶系（アナターゼ型）
（ｂ）光触媒Ｂ：平均粒径７nmの光触媒酸化チタン粉末
結晶系（アナターゼ型）
＜光触媒含有硬化性ポリシロキサン系無機塗料組成物の製法＞
(i)各無機成分を用いた場合の光触媒塗料の製法
▲１▼光触媒含有塗料「Ａ−１」、「Ａ−４」：
上記製法で得られたオルガノシロキサンの部分加水分解縮合物「（ロ）−▲１▼」（塗料Ａ−１の場合）または「(ロ)−▲２▼」（塗料Ａ−４の場合）を秤量し、触媒を添加した後、イソプロパノール（ＩＰＡ）とメタノールの混合溶媒を添加し、希釈した後、1時間静置した。この溶液をポリエチレン製の計量容器に流し込み、光触媒酸化チタン粉末を添加し、ディスパーサーを用いて攪拌し、光触媒微粒子を溶剤に親和させた。この混合溶液を光触媒酸化チタン粉末（ＳＴ−０１）を添加し、０．７ｍｍのジルコニアビーズを用いたジルコニアベッセルにて一次粒径まで光触媒微粒子を粉砕して安定化させることにより、目的とする光触媒含有硬化性ポリシロキサン系無機塗料「Ａ−１」、「Ａ−４」を調製した。
【０１６８】
▲２▼光触媒含有塗料「Ａ−２」：
上記製法で得られたオルガノシロキサンの部分加水分解縮合物「（ロ）−▲１▼」を秤量し、触媒を添加した後、ＩＰＡとメタノールの混合溶媒を添加し、希釈した後、1時間静置した。この溶液を攪拌しながら、硝酸水溶液分散光触媒酸化チタンゾルを滴下ロートを用いて１０分間かけて緩やかに滴下し、目的とする光触媒含有硬化性ポリシロキサン系無機塗料組成物「Ａ−２」を調製した。
【０１６９】
▲３▼光触媒含有塗料「Ａ−３」：
上記製法で得られた硬化性オルガノポリシロキサン（ハ）を秤量し、触媒を添加した後、メタノールとエタノールの混合溶媒を添加し、希釈した後、1時間静置した。この溶液をポリエチレン製の計量容器に流し込み、光触媒酸化チタン粉末を添加し、ディスパーサーを用いて攪拌し、光触媒微粒子を溶剤に親和させた。この混合溶液を０．７ｍｍのジルコニアビーズを用いたジルコニアベッセルミルにて1次粒径まで光触媒微粒子を粉砕し、安定化することにより、目的とする光触媒含有硬化性ポリシロキサン系無機塗料「Ａ−３」を調製した。
【０１７０】
▲４▼光触媒含有塗料「Ａ−５」：
上記製法で得られた硬化性オルガノポリシロキサン（ハ）を秤量し、触媒を添加した後、ＩＰＡとメタノールの混合溶媒を添加し、希釈した後、1時間静置した。この溶液を攪拌しながら、硝酸水溶液分散光触媒酸化チタンゾルを滴下ロートを用いて１０分間かけて緩やかに滴下し、目的とする光触媒含有硬化性ポリシロキサン系無機塗料組成物「Ａ−５」を調製した。
【０１７１】
▲５▼光触媒含有塗料「Ａ−７」：
上記製法で得られたオルガノシロキサンの部分加水分解縮合物（ロ）と硬化性オルガノポリシロキサン（ハ）を所定の比で混合し、触媒を添加した後、エタノールとメタノールの混合溶剤を添加し、希釈した後、1時間静置した。この溶液をポリエチレン製の計量容器に流し込み、光触媒酸化チタン粉末を添加し、ディスパーサーを用いて攪拌し、光触媒微粒子を溶剤に親和させた。この混合溶液を0.7ｍｍのジルコニアビーズを用いたジルコニアベッセルミルにて1次粒径まで光触媒微粒子を粉砕し、安定化することにより、目的とする光触媒含有硬化性ポリシロキサン系無機塗料「Ａ−７」を調製した。
【０１７２】
▲６▼光触媒含有塗料「Ａ−８」：
上記製法で得られたオルガノシロキサンの部分加水分解縮合物「（ロ）−▲２▼」と硬化性オルガノポリシロキサン（ハ）を所定の比で混合し、触媒を添加した後、ＩＰＡとメタノールの混合溶媒を添加し、希釈した後、1時間静置した。この溶液を攪拌しながら、硝酸水溶液分散光触媒酸化チタンゾルを滴下ロートを用いて１０分間かけて緩やかに滴下し、目的とする光触媒含有硬化性ポリシロキサン系無機塗料組成物「Ａ−８」を調製した。
【０１７３】
▲７▼光触媒含有塗料「Ａ−６」：
上記製法で得られたオルガノシロキサンの部分加水分解縮合物「（ロ）−▲２▼」とアクリルシリコーン樹脂を秤量し、触媒を添加した後、ＩＰＡとメタノールの混合溶媒を添加し、希釈した後、1時間静置した。この溶液をポリエチレン製の計量容器に流し込み、光触媒酸化チタン粉末を添加し、ディスパーサーを用いて攪拌し、光触媒粒子を溶剤に親和させた。この混合溶液に光触媒酸化チタン粉末（ＳＴ−０１）を添加し、０．７ｍｍのジルコニアビーズを用いたジルコニアベッセルにて一次粒径まで光触媒微粒子を粉砕して安定化させることにより、目的とする光触媒含有硬化性ポリシロキサン系無機塗料「Ａ−６」を調製した。
【０１７４】
▲８▼光触媒含有塗料「Ａ−９」：
上記製法で得られたオルガノシロキサンの部分加水分解縮合物「（ロ）−▲１▼」と硬化性オルガノポリシロキサン(ハ)とアクリルシリコーン樹脂を所定の量比で混合し、触媒を添加した後、ＩＰＡとメタノールの混合溶媒を添加し、希釈した後、1時間静置した。この溶液を硝酸水溶液分散光触媒酸化チタンゾルを滴下ロートを用いて１０分間かけて緩やかに滴下し、目的とする光触媒含有硬化性ポリシロキサン系無機塗料「Ａ−９」を調製した。
【０１７５】
＜価試験項目＞
また、実施例、比較例で用いた各種物性測定方法は以下のとおり
(a) 耐汚染性試験；屋外暴露１ヶ月後の耐汚染性試験
試験体パネルを国道８号線沿いの汚染の厳しい個所に設置し、１ヶ月間放置した後の汚れの状態を目視と色差測定から確認した。
【０１７６】
３：目視による汚染性はなく、外観良好。かつΔE変化率：１未満。
２：まばらに汚染個所があり、全体的に薄く黒ずむ。かつΔE変化率：１以上２未満。
１：全体的に黒い煤が付着し、ひどく汚れた状態。かつΔE変化率：２以上。
(b) 付着性（ JIS K-5400 、 8 .5 碁盤目法に準ずる）
すきま間隔２mm、ます目２５で評価する。
【０１７７】
３：切り傷１本ごとが、細くて両側が滑らかで、切り傷の交点と正方形の一目一目に剥がれがない。
２：切り傷の両側と交点とに剥がれがあって、欠陥部の面積は全正方形面積の１５％未満。
１：切り傷の両側と交点とに剥がれがあって、欠陥部の面積は全正方形面積の１５％以上。
【０１７８】
(c) 耐候性（ JIS K-5400 9.8.1 サンシャインカーボンアーク灯式による）
１５００時間後の光沢保持率および色差を「JIS D-0205 7.6光線変化率の変化及び7. 4」に準拠して、変退色を評価する。
３：ほとんど変化が認められない。光沢保持率８５％以上。色差１．５未満。
２：光沢保持率６０％以上８５未満。色差１．５以上。
【０１７９】
１：光沢保持率６０％未満。色差１．５以上。
(d) 鉛筆硬度（ JIS K-5400 8.4.1 試験機法による）
塗膜のすり傷で評価する。
３：５H以上。
２：２H以上５H未満。
【０１８０】
１：２H未満。
(e) 耐塩水性（ JIS K-5400 9.1 による）
５００時間試験後の塗膜の外観及びカット部のフクレ巾を調査する。
３：塗膜外観に異常が認められない。フクレ巾が３ｍｍ未満。
２：塗膜外観に異常が認められない。フクレ巾が３ｍｍ以上。
【０１８１】
１：塗膜にフクレ、発錆が見られ、片側のフクレ巾が３ｍｍ以上。
(f) 耐湿性（ JIS K-5400 9.2 回転式による）
５００時間試験後の塗膜の外観を調査する。
３：塗膜外観に異常が認められない。
２：塗膜外観に曇りが認められる。
【０１８２】
１：塗膜外観にしわ、フクレ、ワレ、さび、剥がれのいずれかが認められる。
【０１８３】
【実施例１】
被塗物基材として、予め化成処理（種類：リン酸亜鉛処理 ）が施された基材（材質：軟質鋼板、寸法：２×１５０×７０ｍｍ）の表面に、表１に示す上記粉体塗料（番号：Ｐ−１）を、塗装機（種類：静電粉体塗装機）にて、４回塗装し、その後、乾燥機（機種：恒温器、型番：ＰＨＨ−１０１、製造元：タバイエスペック社）にて、温度１７０℃で２０分間加熱し、平均膜厚６０μｍ厚の下塗塗膜を形成した。
【０１８４】
次いで、該下塗塗膜表面に、表１に示す中塗用の着色塗料（番号：Ｃ−１）を平均塗布膜厚４０μｍ厚になるようにスプレー塗装し、次いで、条件（加熱温度；１７０℃、時間：２０分間）で乾燥又は硬化反応を行って、乾燥膜厚が２０μｍの中間塗膜を形成した。
次いで、該中間塗膜表面に、表２の光触媒含有塗料（番号：Ａ−１）を平均塗布膜厚１０μｍ厚になるようにスプレー塗装し、次いで、条件（加熱温度；１７０℃、時間：２０分間）で乾燥又は硬化反応を行って、乾燥膜厚が０．５μｍ厚の試験板を得た。
【０１８５】
得られた試験板について上記に示す方法で各試験を行い、性能を評価した。
その結果は下記のように諸特性がバランス良く優れていた。
(イ)耐汚染性：３（目視では汚染は認められず、外観良好で、△Ｅ変化率すなわち、「色の変化を表す指標であって、塗装直後の塗膜と比較して、屋外暴露
１ヶ月後の塗膜の色の変化を表す指標」は１以内。）
(ロ)耐候性：３（JIS K-5400,9.8.1に準拠。殆ど色変化ない。光沢保持率８５％以上。色差１．５未満。）
(ハ)鉛筆硬度：３（JIS K-5400,8.１準拠。塗膜の耐擦傷性：５Ｈ以上。）
(ニ)耐円塩水噴霧性（耐塩水性）：３（JIS, K-5400,9．1に準拠。塗膜外観に異常なし。フクレ幅３ｍｍ未満。）
(ホ)耐湿性：３（JIS K-5400,9.2回転式準拠。５００時間試験後、塗膜外観に異常なし。）。
【０１８６】
結果を併せて表３に示す。
【０１８７】
【実施例２〜３６、比較例１〜２】
実施例１において、下塗粉体塗料、中塗り着色塗料、上塗光触媒含有塗料を、それぞれ表１〜表３に示すように変更した以外は、実施例１と同様にして塗装試験板を作製し、上記と同様の試験を行い、性能を評価した。
結果を表３に示す。
【０１８８】
以下の表中の各成分量は、「重量部」表示で示す。
【０１８９】
【表１】

【０１９０】
【表２】

【０１９１】
【表３】

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a composite such as a coating film, a base material coated with a coating film comprising the composite, and a method for manufacturing a base material with a coating film. More specifically, for example, provided on the surface of a building material such as a metal panel. Composites capable of forming a coating film excellent in film thickness and anticorrosion properties, and having excellent stain resistance, durability and surface hardness, a substrate coated with a coating film comprising the composite, and such The present invention relates to a method for producing a substrate with a coated film.
[0002]
TECHNICAL BACKGROUND OF THE INVENTION
Conventionally, for example, road-related materials such as guardrails and fences; building materials such as roofing materials, trunk edges, shutters, gutters, and outer wall materials; automobile parts such as automobile exterior materials; home appliances such as air conditioner outdoor units; As described above, metal parts used for outdoor use cause scars due to collision of debris that has been blown off as vehicles pass through, automobile exhaust gas, dust that has risen in the air as vehicles pass through, and dripping pollution. In addition, the scars and dust attached to these outdoor members cannot be easily removed, and the aesthetics of metal members used in outdoor applications are significantly impaired. There is. Therefore, the paint used for such an outdoor member is required to form a coating film excellent in durability, coating film surface hardness, contamination resistance, and the like.
[0003]
For example, a thermosetting powder coating can form a thick film having a thickness of 50 μm or more with one coat, and also has good anticorrosion properties. Therefore, the thermosetting powder coating material is often used for applications requiring anticorrosion properties as described above. .
However, conventional powder coatings are not sufficient in stain resistance and coating film hardness, and the durability is inferior compared to the case of using a silicone resin-based or fluororesin-based highly weather-resistant solvent-based coating. There is a problem.
[0004]
Therefore, the present inventors conducted extensive research to solve the above problems.For example, on the surface of a base material such as a metal plate, an undercoating film made of a powder paint and a specific color pigment-containing curable polymer. If an intermediate coating film formed from a siloxane-based inorganic coating composition and a topcoat coating film formed from a photocatalyst-containing curable polysiloxane-based inorganic coating composition blended with specific components are sequentially laminated, the film thickness Have been found to be able to produce composites such as coatings with excellent balance and excellent properties in terms of anti-staining and anti-corrosion properties, stain resistance, durability, coating film hardness (surface hardness), etc. The present invention has been completed.
[0005]
In addition, (1): Japanese Patent Laid-Open No. 5-31455 discloses that a coating layer containing an organic component as a main component is formed on a member to be coated such as an aluminum wheel for vehicles, and an inorganic system is formed on the surface of the coating layer. Disclosed is a coating film structure in which a coating layer containing the components as a main component is formed, and the organic coating layer includes thermosetting of acrylic resin, polyester resin, epoxy resin, vinyl chloride resin, urethane resin, aminoalkyd resin, etc. Examples of the coating layer mainly composed of an inorganic component include colloidal silica, organoalkoxysilane partial hydrolysis condensate, and a polymer or copolymer of an unsaturated ethylenic monomer. The main component can be mentioned, and these layers are obtained by applying a corresponding powder coating and baking. According to the coating film structure, the appearance is improved by increasing the film thickness, the choice of colors and paints is abundant, and it is easy to remove dirt adhered to the coating film surface, and the effect that the coating film is hard to be damaged is obtained. Are listed.
[0006]
(2): Japanese Patent Application Laid-Open No. 7-60184 discloses that a coating film containing a polysiloxane inorganic polymer is applied after a thermosetting powder coating is applied and baked on an object to be coated. And the composite coating film formation method which raise | generates hardening reaction and forms the coating film which has an inorganic polymer compound on a powder coating film is disclosed. According to the method described in the publication, it is possible to provide a coating film having excellent corrosion resistance, weather resistance and stain resistance, and having a high hardness, and the coating film is particularly useful for an object to be coated outdoors. It is described that.
[0007]
(3): Japanese Patent Laid-Open No. 8-259891 discloses (A) Formula Si (OR¹ )_Four A silicon compound and / or colloidal silica represented by formula (B):² Si (OR¹ )_Three (C) Formula R² ₂Si (OR¹ )₂ A silicon compound represented by the formula:¹ , R² It describes that a liquid mixture of an inorganic coating prepared using a raw material of a monovalent hydrocarbon group and a powder having a photocatalytic function is applied to a substrate.
[0008]
(4): Japanese Patent Application Laid-Open No. 2000-26801 describes a functional coating composition in which a photocatalyst is blended with the following film forming components (a) to (d).
(A) A composition comprising an organopolysiloxane as a main component and an organosiloxane having a functional side chain as a crosslinking agent and a curing catalyst.
(B) A composition in which a solvent for high heat is blended with ceramic particles.
(C) An organic solvent solution of perhydropolysilazane.
(D) A prepolymer prepared by reacting a low molecular weight glycidyl ether type epoxy resin with a catalyst in the presence of a metal oxide powder.
[0009]
(5): JP-A-11-188271 discloses a photocatalyst obtained by adhering a photocatalyst to a substrate via a hardly decomposable binder, wherein the hardly decomposable binder is water glass or colloidal silica. A photocatalyst that is at least one silicon compound selected from polyorganosiloxanes is disclosed. Examples of the hardly decomposable binder include water glass, colloidal silica, polyorganosiloxane, phosphate, and fluorine-based polymer. Further, a second layer made of an organic binder such as an epoxy resin or a polyester resin and not containing photocatalyst particles is provided on the substrate, and a second layer made of photocatalyst particles and a hardly decomposable binder is provided thereon. It is stated that a layer can be provided.
[0010]
(6): Japanese Patent Application Laid-Open No. 2000-4280 discloses a film forming method in which a silica-based or silicone-based film-forming coating solution is applied to a surface of a substrate by a specific method, and then the obtained coating film is cured. It is disclosed. In this publication, various coated surfaces such as unsaturated polyester resin paints and powder paints are listed as substrates. In addition, it is described that the film-forming coating solution may contain metal compound particles such as titanium dioxide and titanium peroxide having photocatalytic activity. In addition, the publication discloses that an aqueous solution of ethanol containing a partial hydrolyzate of ethyl silicate (containing an acid catalyst) is applied and cured on the surface of a polyester melamine white painted iron plate, and then the surface of the obtained base material (intermediate layer). An embodiment in which an alcoholic dispersion liquid containing titanium dioxide fine particles and a partial hydrolyzate of silicon dioxide as a binder is applied and cured is shown.
[0011]
Further, (7): Japanese Patent Laid-Open No. 2000-51782 discloses a method in which a coating material is made to contain a fluorescent dye and a coating operation is performed by discriminating between a coated portion and a non-coated portion of a base material by fluorescence emitted from a coating film. Is disclosed. As a coating liquid, it is described that a silica-based or silicone-based film-forming coating liquid containing a photocatalyst is applied to a base material, and examples of the base material include various coated surfaces such as unsaturated polyester resin paints and powder paints. ing. In addition, the publication discloses that a surface of a polyester melamine white coated iron plate is coated and cured with a partially hydrolyzed product of ethyl silicate (containing an acid catalyst) and an ethanol aqueous solution containing a fluorescent brightening agent, and then the obtained base material A mode in which an alcoholic dispersion liquid containing titanium dioxide fine particles, a partial hydrolyzate of ethyl silicate as a binder, and a fluorescent whitening agent is applied and cured on the surface of the (intermediate layer) is shown.
[0012]
However, even in the coating film described in any of the publications of (1) to (7), adhesion to the surface of a substrate such as metal, film thickness, corrosion resistance, durability, coating film hardness, and contamination resistance There was room for further improvement in terms of characteristics such as and the balance thereof.
In any of these publications, an undercoat film made of a powder coating and an intermediate coating film formed from a specific color pigment-containing curable polysiloxane inorganic coating composition on the surface of a substrate such as a metal plate And a topcoat coating film formed from a photocatalyst-containing curable polysiloxane inorganic coating composition containing a specific component, the film thickness is not only excellent in adhesion to the substrate, but also the film thickness. In addition to corrosion resistance, corrosion resistance, durability, and coating film hardness, it is extremely superior in terms of contamination resistance, etc., and also has excellent balance of these characteristics, such as composites such as coating films, substrates with coating films, etc. There is no description or suggestion that it can be manufactured.
[0013]
OBJECT OF THE INVENTION
The present invention is intended to solve the problems associated with the prior art as described above, and is excellent in film thickness and anticorrosion properties, and also in terms of durability, coating film hardness, stain resistance, and the like. An object of the present invention is to provide a composite such as a coated film, a substrate with a coated film, and a method for producing the same.
[0014]
SUMMARY OF THE INVENTION
The complex according to the present invention is:
(I) an undercoat film formed from a powder paint;
(II) an intermediate coating film provided on the undercoat powder coating film (I) and formed from a color pigment-containing curable polysiloxane inorganic coating composition;
(III) a top coat film provided on the intermediate coating film (II) and formed from a photocatalyst-containing curable polysiloxane inorganic coating composition,
The colored pigment-containing curable polysiloxane inorganic coating composition is
(A) a coloring pigment;
(B) Organosiloxane, its partially hydrolyzed condensate or curable organopolysiloxane, and if necessary
(C) a curing catalyst for the component (B)
Containing
The photocatalyst-containing curable polysiloxane inorganic coating composition is
(D) a photocatalyst for activating a cured coating film containing titanium oxide as a main component;
(B) Organosiloxane, its partially hydrolyzed condensate or curable organopolysiloxane, and if necessary
(C) a curing catalyst for the component (B)
It is characterized by containing.
[0015]
In the present invention, the powder coating is selected from the group consisting of a fluororesin powder coating, a polyester resin powder coating, an epoxy resin powder coating, an acrylic resin powder coating, and a urethane resin powder coating. Preferably, the at least one paint is used.
In the present invention, the titanium oxide is preferably an anatase type titanium oxide, and more preferably, the titanium oxide is an anatase type titanium oxide having an average particle diameter of 7 to 250 nm.
[0016]
In the present invention, the color pigment-containing curable polysiloxane inorganic coating composition and / or the photocatalyst-containing curable polysiloxane inorganic coating composition further comprises (E) a polymerizable silicone (meth) acrylate copolymer. Preferably, the polymerizable silicone (meth) acrylate copolymer (E) is preferably acrylic silicone.
[0017]
In the present invention, when the photocatalyst-containing curable polysiloxane-based inorganic coating composition has a total of components (B), (C), (D), and (E) as 100 parts by weight,
Component (B) in an amount of 20-80 parts by weight, preferably 30-70 parts by weight,
Component (C) in an amount of 0 to 10 parts by weight, preferably 0.01 to 5 parts by weight, and
Component (D) in an amount of 20 to 80 parts by weight, preferably 30 to 70 parts by weight,
It is desirable to contain component (E) in an amount of 0 to 50 parts by weight, preferably 0 to 40 parts by weight.
[0018]
In the present invention, the curing catalyst (C) for the component (B) is preferably a carboxylic acid metal salt, an amine, an acid, an alkali catalyst, a titanium compound, or a halogenated silane.
In the present invention, the photocatalyst-containing curable polysiloxane inorganic coating composition may further contain (A) a color pigment.
[0019]
In the present invention, the photocatalyst-containing curable polysiloxane inorganic coating composition may further contain an organosilica sol as the (F) inorganic binder.
In the present invention, the composite is preferably a coating film, particularly a coating film provided on the substrate so that the composite undercoat (I) side is in close contact with or opposed to the substrate.
[0020]
The base material with a coating film according to the present invention is composed of a base material and a coating film made of the above-mentioned composite provided on the surface of the base material, and the undercoat (I) side of the composite is a base material. It is characterized by being adhered directly or through other layers.
As for the base material with a coating film which concerns on this invention, it is desirable that the said base material is a metal panel and a building material.
[0021]
The method for producing a coated substrate according to the present invention comprises a substrate surface,
Apply and harden powder paint (I)
On the surface of the obtained undercoat film (I), the above-mentioned color pigment-containing curable polysiloxane inorganic coating composition is applied and cured,
The photocatalyst-containing curable polysiloxane inorganic coating composition is applied to the surface of the obtained intermediate coating film (II) and cured to form a topcoat coating film (III).
[0022]
According to the present invention, for example, by providing it on the surface of a building material such as a metal panel, a composite that can form a coating film excellent in film thickness and corrosion resistance, and excellent in stain resistance, durability, surface hardness, A substrate coated with a coating film comprising the composite and a method for producing such a coated substrate are provided.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a composite according to the present invention, a base material coated with a coating film made of the composite, and a method for producing a base material with a coating film will be specifically described.
<Composite>
The composite according to the present invention is formed from a powder paint, and is provided on the undercoat film (I) serving as an undercoat layer, and the undercoat film (I), and a color pigment-containing curable polysiloxane inorganic paint composition An intermediate coating layer (II) which is formed from a product (also simply referred to as a colored coating) and serves as an intermediate coating layer, and a photocatalyst-containing curable polysiloxane inorganic coating composition ( It is also simply referred to as a photocatalyst-containing inorganic paint.) And has a top coat film (III) as an overcoat layer.
[0024]
This composite body can take various shapes, and may be, for example, various molded bodies such as a container and a bag in addition to a coating film, a sheet, a film, a substrate and the like.
When this composite is a coating film, it is provided on the surface of the base material such as metal so that the side surface of the base coating film (I) is in close contact with the base material directly or through another layer (eg sealer) Also good. Thus, in the case where the composite is a coating film provided on the surface of a substrate of metal or the like (eg, a metal processed product such as a guard rail, a fence, a metal panel for building materials, an electric product, or an automobile part), The coating film is excellent in film thickness and anticorrosion properties, and is excellent in a good balance between contamination resistance, durability and surface hardness. In particular, if the coating film (composite) is provided on the surface of a member for outdoor use, such as a guardrail, an automobile exterior material, or a building material, so that the surface of the primer coating (I) is in close contact with the base material, The above characteristics are exhibited in a well-balanced manner.
[0025]
The material of the substrate to be coated may be inorganic or organic. Specifically, for example, metals such as aluminum, iron, stainless steel, copper, and zinc; various glassy materials; ceramics; porcelain; concrete; ceramics such as stone materials; Wood boards such as natural boards and plywood; various plastic boards; and combinations thereof.
Among these, inorganic materials such as metal, glass, ceramics / porcelain, concrete, and ceramic are preferable in terms of adhesion and durability.
[0026]
In addition, base materials made of such organic or inorganic materials include road-related materials such as guardrails and fences; building materials such as roofing materials, trunk edges, shutters, gutters, and outer wall materials; automobile exterior materials, etc. Suitable examples include metal parts used in outdoor applications such as automobile parts; home appliances such as air conditioner outdoor units;
In such a complex of the present invention,
The film thickness of the undercoat film (I) is usually 20 to 150 μm, preferably 30 to 100 μm,
The film thickness of the intermediate coating film (II) is usually 1 to 100 μm, preferably 10 to 50 μm,
The film thickness of the topcoat coating film (III) is usually 0.01 to 50 μm, preferably 0.1 to 30 μm.
[0027]
Hereinafter, the undercoat coating film (I), the intermediate coating film (II), and the topcoat coating film (III) constituting the composite will be described in detail.
[Undercoat ( I ]]
The powder coating film (undercoat layer) (I) can employ various molding methods depending on the shape and application of the resulting composite, and preferably, a powder coating is applied (painted) or injected into a mold. Then, it is heated and cured.
[0028]
As the powder coating used, it is desirable that the contained powder particles do not fuse during handling of the powder coating both indoors and outdoors, and the softening point of the contained resin [measurement method: Vicat softening point] is For example, a thermosetting resin-based or thermoplastic resin-based powder coating at 30 to 140 ° C., preferably 80 to 120 ° C., may be mentioned, among which a thermosetting resin-based one is preferable.
[0029]
Thermosetting powder paints include fluororesin powder paint, polyester resin powder paint, epoxy resin powder paint, acrylic resin powder paint, urethane resin powder paint, amino alkyd resin powder paint. Etc. Among these, fluororesin-based powder coatings, polyester resin-based powder coatings, epoxy resin-based powder coatings, acrylic resin-based powder coatings, and urethane resin-based powder coatings are preferable, and epoxy resin-based powder coatings are particularly preferable. Preferably, when this epoxy resin powder coating is used, the resulting coating is excellent in adhesion with the intermediate coating (II) and anticorrosion in a single film, and the resulting composite, especially the coating, It is preferable because it is excellent in corrosion resistance and durability, has high hardness, and is excellent in stain resistance. You may use these 1 type or in combination of 2 or more types. Examples of the thermoplastic resin powder coating that can be used include polyvinyl chloride, polyethylene, and nylon.
[0030]
Among these thermosetting powder coatings, fluororesin-based powder coatings, polyester resin-based powder coatings, epoxy resin-based powder coatings, and acrylic resin-based powder coatings are disclosed in JP-A-7-60184 [0005]. ] To [0013] can be preferably used.
Fluorine resin powder coating
That is, the fluororesin-based powder coating has a crosslinkable reactive group, is solid at normal temperature, and has a glass transition temperature (Tg) of 35 to 120 ° C. What contains 40 to 3 weight% of hardening | curing agents which can react with the crosslinkable reactive group of resin and can form bridge | crosslinking (total of 100 weight% of both) is used preferably. This fluororesin having a crosslinkable reactive group can be produced by polymerization by a known method.
[0031]
Examples of the crosslinkable reactive group include a hydroxyl group, an epoxy group, and a carboxyl group. When a fluororesin having a hydroxyl group as a crosslinkable reactive group is used, the hydroxyl value is desirably in the range of 1 to 200 mgKOH / g, preferably 20 to 140 mgKOH / g. Moreover, when using the fluororesin which has an epoxy group as a crosslinkable reactive group, the epoxy equivalent is 100-15000 g / eq, Preferably it is desirable to exist in the range of 300-14000 g / eq.
[0032]
Further, when a fluororesin having a carboxyl group as a crosslinkable reactive group is used, the acid value is desirably in the range of 1 to 200 mgKOH / g, preferably 20 to 140 mgKOH / g.
When these hydroxyl value, epoxy equivalent, acid value and the like are in the above ranges, there is a tendency that a crosslink density is appropriate and a composite having excellent physical properties such as flexibility, particularly a coating film, is obtained.
[0033]
The fluororesin preferably has a glass transition temperature (Tg) of 35 to 120 ° C, preferably 40 to 100 ° C. If this glass transition temperature (Tg) is in the above range, the resin powder becomes solid at room temperature, so there is no risk of fusion between the resin powders during storage, etc., and it is well dispersed as a powder and easy to use in powder coatings. In addition, the softening point is moderate and the flowability during painting is good.
[0034]
Moreover, it is desirable that the average particle diameter of the resin (main agent) is usually about 10 to 500 μm, including the following other powder coating resins. Resin particles having such particle diameters are less charged and less dusty, have good particle melting properties, and have good appearances such as coating films and molded products. In addition, an average particle diameter can be measured here, for example using the process particle size distribution measuring system "TSUB-TEC300" [made by Nippon Mining Co., Ltd.].
[0035]
Polyester resin powder coating
The polyester resin powder coating material has a crosslinkable reactive group, is solid at room temperature, and has a Tg of 35 to 120 ° C., 50 to 97% by weight, and reacts with the crosslinkable reactive group of the polyester resin. Thus, those containing 50 to 3% by weight of a curing agent capable of forming a crosslink (total 100% by weight of both) are preferably used.
[0036]
Examples of the crosslinkable reactive group of the polyester resin include a hydroxyl group and a carboxyl group, and these crosslinkable reactive groups may be included in one or two types.
The polyester resin having a crosslinkable reactive group is a resin that is solid at room temperature having an average of 2 or more reactive groups per molecule, and has a number average molecular weight (Mn) of 1000 to 20000, preferably 1500 to 8000. Is preferred.
[0037]
Further, when the crosslinkable reactive group is a hydroxyl group, the hydroxyl value is desirably in the range of 1 to 200 mgKOH / g, preferably 20 to 140 mgKOH.
When the crosslinkable reactive group is a carboxyl group, the acid value is desirably in the range of 1 to 200 mgKOH / g, preferably 20 to 140 mgKOH / g.
When the hydroxyl value and acid value are in the above ranges, there is a tendency that a composite having a moderate crosslinking density and excellent physical properties such as flexibility, particularly a coating film, is obtained.
[0038]
A polyester resin having a Tg of 35 to 120 ° C., preferably 40 to 100 ° C. is suitable. If this glass transition temperature (Tg) is in the above range, the resin powder becomes solid at room temperature, so there is no risk of fusion between the resin powders during storage, etc., and it is well dispersed as a powder and easy to use in powder coatings. In addition, the softening point is moderate and the flowability during painting is good.
[0039]
The polyester resin can be obtained, for example, by directly esterifying a polyester-forming carboxylic acid and a polyhydric alcohol mainly composed of ethylene glycol, or a commercially available product can be used.
Examples of the polyester-forming carboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, β-oxypropionic acid, oxalic acid, maleic anhydride, trimellitic anhydride, pyromellitic acid. An acid etc. are mentioned, These may be used 1 type or in combination of 2 or more types.
[0040]
Examples of the polyhydric alcohol include ethylene glycol, propanediol, butanediol, pentanediol, 1,6-hexanediol, neopentylglycol, 2,2′-diethylpropanediol, cyclohexanediol, trimethylolpropane, and pentaerythritol. These may be used alone or in combination of two or more.
[0041]
Epoxy resin powder coating
The epoxy resin powder coating material has a crosslinkable reactive group, is solid at normal temperature, and reacts with 60 to 97% by weight of an epoxy resin having a Tg of 35 to 120 ° C. and the crosslinkable reactive group of the epoxy resin. Thus, those containing 40 to 3 wt% of a curing agent capable of forming a crosslink (total of 100 wt% of both) are preferably used.
[0042]
The epoxy resin preferably has an average of two or more epoxy groups per molecule, and examples thereof include bisphenol type epoxy resins, hydrogenated bisphenol type epoxy resins, ester type epoxy resins, and the like, and commercially available products are used. You can also.
The number average molecular weight (Mn) of the epoxy resin is preferably in the range of 300 to 8000, and the epoxy equivalent is preferably in the range of 100 to 15000 g / eq, preferably 300 to 14000 g / eq.
[0043]
When the number average molecular weight and the epoxy equivalent are in such ranges, the crosslinking density is appropriate and the physical properties such as flexibility are good.
The epoxy resin preferably has a Tg of 35 to 120 ° C., preferably 40 to 100 ° C. When the Tg is in such a range, the epoxy resin becomes solid at room temperature and is used for powder coatings. It is easy to handle, has a moderate softening point, is easy to handle, and has good flowability during painting.
[0044]
Acrylic resin powder coating
As an acrylic resin-based powder coating material, it has a crosslinkable reactive group, is solid at room temperature, has a Tg of 35 to 120 ° C., and reacts with the crosslinkable reactive group of the acrylic resin. Thus, those containing 40 to 3 wt% of a curing agent capable of forming a crosslink (total of 100 wt% of both) are preferably used.
[0045]
The acrylic resin having a crosslinkable reactive group is preferably a resin that is solid at room temperature having an average of 2 or more reactive groups per molecule and has a number average molecular weight (Mn) of 1000 to 20000.
When the crosslinkable reactive group is a hydroxyl group, the hydroxyl value is desirably in the range of 1 to 200 mgKOH / g, preferably 20 to 140 mgKOH / g.
[0046]
When the crosslinkable reactive group is a carboxyl group, the acid value is desirably in the range of 1 to 200 mgKOH / g, preferably 20 to 140 mgKOH / g.
Furthermore, when the crosslinkable reactive group is an epoxy group, the epoxy equivalent is desirably in the range of 100 to 15000 g / eq, preferably 300 to 14000 g / eq. When these hydroxyl value, epoxy equivalent, and acid value are in the above ranges, there is a tendency that a crosslink density is appropriate and a composite having excellent physical properties such as flexibility, particularly a coating film, is obtained.
[0047]
The acrylic resin having a Tg of 35 to 120 ° C., preferably 40 to 100 ° C. is suitable. When the Tg is in such a range, the acrylic resin becomes solid at room temperature and is easy to use for powder coatings. The softening point is moderate and easy to handle, and the flowability during painting is good.
The acrylic resin having a crosslinkable reactive group includes, for example, a polymerizable vinyl monomer having a hydroxyl group, a carboxyl group, an epoxy group, an amide group, an amino group, a mercapto group, an isocyanate group, a halogen atom, and the like, and a copolymer thereof. It can be obtained by copolymerizing possible "other vinyl monomers".
[0048]
Preferred examples of the vinyl monomer containing a hydroxyl group include mono (meth) acrylic acid ester and monochlorotonic acid ester of monohydric alcohol, allyl alcohol, monoallyl ether of polyhydric alcohol, and hydroxyethyl vinyl ether. be able to.
Examples of the polyhydric alcohol include dihydric alcohols such as ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, and 1,6-hexanediol, glycerin, and trimethylol. Propane, trimethylolethane, pentaerythritol and the like can be mentioned. In addition to the polyhydric alcohol, dihydroxyethyl fumarate, butylhydroxyethyl fumarate and the like can also be used.
[0049]
Examples of the vinyl monomer containing a carboxyl group include unsaturated acids containing a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid.
Moreover, as a vinyl-type monomer containing the said epoxy group, glycidyl acrylate, glycidyl methacrylate, (beta) -methyl glycidyl acrylate, (beta) -methyl glycidyl methacrylate, etc. can be mentioned preferably, for example.
[0050]
Examples of the above “other vinyl monomers” that can be copolymerized include alkyl acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; styrene, α-methyl styrene Aromatic vinyl compounds such as: vinyl acetate, vinyl propionate, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, vinyl stearate, acrylic acetate, dialkyl esters of fumaric acid, dialkyl esters of itaconic acid, halogen-containing vinyl monomers , Silicon-containing vinyl monomers, ethylene and the like, and can be used alone or as a mixture when used.
[0051]
The acrylic resin having a crosslinkable reactive group can be produced by copolymerizing the vinyl monomer in the presence of a normal polymerization initiator by a conventionally known suspension polymerization method or solution polymerization method. It is also possible to use a commercial product.
Urethane resin powder coating
The urethane resin powder coating material has a crosslinkable reactive group, is solid at normal temperature, and has a Tg of 30 to 150 ° C., a polyol of 60 to 97% by weight, a crosslinkable reactive group (OH) of the polyol, Those containing 3 to 40% by weight of an isocyanate-based curing agent capable of forming a crosslink by reaction (total 100% by weight of both) are preferably used.
[0052]
The polyol preferably has an average of two or more reactive groups per molecule and is solid at normal temperature and has a number average molecular weight (Mn) of 1000 to 20000.
The hydroxyl value is desirably in the range of 1 to 200 mg KOH / g, preferably 20 to 140 mg KOH / g.
That's right. When this hydroxyl value is in the above range, the crosslinking density is moderate, and there is a tendency that a composite, particularly a coating film, having excellent physical properties such as flexibility can be obtained.
[0053]
The polyol preferably has a Tg of 30 to 120 ° C, preferably 35 to 100 ° C. When the Tg is in such a range, it becomes a solid at room temperature and is easy to use for powder coatings. The softening point is moderate and easy to handle, and the flowability during painting is good.
The urethane resin contained in such a urethane resin powder coating is obtained, for example, by reacting diisocyanates and polyols, and has a urethane bond (—NH—COO—).
[0054]
Examples of such a urethane resin powder coating material include one-pack type and block type ones.
As this one-component and block-type urethane resin powder coating, for example, containing a main component polyols and a curing agent,
As described later, for example, an isocyanate group (NCO group) of a polyisocyanate composed of a diisocyanate such as isophorone diisocyanate (IPDI) (that is, a curing agent described later) is blocked with a blocking agent such as ε-caprolactam. Examples thereof include paints that are blocked isocyanate compounds formed into blocks (masks).
[0055]
In order to heat and cure the urethane resin powder coating material, for example, in the presence of an active hydrogen compound, the blocked portion is dissociated by heating to regenerate the isocyanate, cause a substitution reaction, and crosslink. Good.
As the diisocyanates, the curing agents described later are used. Specifically, hexamethylene diisocyanate [HDI], isophorone diisocyanate [IPDI], methylenebis (4-cyclohexylisocyanate) [HMDI], trimethylhexamethylene diisocyanate [TMHMDI] and the like. Is preferred.
[0056]
Examples of the polyols include poly (alkylene oxide) polyols, polyester polyols, acrylic polyols, fluorine polyols, and polycarbonate polyols.
Specific examples of the poly (alkylene oxide) polyol include poly (propylene oxide) diol, poly (propylene oxide) triol, and poly (tetramethylene oxide) diol.
[0057]
Conventionally known polyester polyols are widely used.
Examples of the blocking agent (masking agent) include alcohols such as ethanol and isopropanol; phenols such as phenol and p-nitrophenol; lactams such as ε-caprolactam; oximes such as acetoxime and methyl ethyl ketone; Examples: active methylenes such as diethyl malonate) and acetoacetate (eg ethyl acetoacetate); and the like.
[0058]
In such various powder coatings, the main agent is usually used in the powder coating in an amount of 50 to 97% by weight, preferably 60 to 97% by weight.
Hardener
On the other hand, when the resin contained in the thermosetting powder coating used in the present invention has a hydroxyl group as a crosslinkable reactive group, the curing agent may be a blocked isocyanate compound such as isophorone diisocyanate [IPDI] or tolylene diisocyanate (TDI). , Xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate [MDI], hexamethylene diisocyanate [HDI], dicyclohexylmethane diisocyanate (hydrogenated MDI), methylenebis (4-cyclohexylisocyanate) [HMDI], trimethylhexamethylene diisocyanate [TMHMDI] 1,5-tetrahydronaphthalene diisocyanate, naphthalene-1,5-diisocyanate, bis (2-methyl-3-isocyanatophenyl) methane, 4,4′-diph Isocyanate groups of isocyanate compounds such as polyisocyanate compounds such as phenylpropane diisocyanate, tetramethylxylylene diisocyanate (TMXDI), dimers, trimers and polyisocyanate compounds modified with polyhydric alcohols such as trimethylolpropane. And compounds blocked with the above-mentioned blocking agents [for example, blocking agents such as lactams such as ε-caprolactam, alcohols such as phenols and benzyl alcohol, and oximes such as methyl ethyl ketoxime]. Such a block isocyanate compound is preferably used in a solid form at room temperature.
[0059]
Also, aliphatic dibasic acids such as fumaric acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, acid anhydrides such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and amino compounds Etc. can be used. Examples of the amino compound include “Powderlink 1174” (trade name) manufactured by American Cyanamid.
[0060]
When the resin contained in the thermosetting powder coating has a carboxyl group as a crosslinkable reactive group, the curing agent includes glycidyl compounds such as terephthalic acid diglycidyl ester, p-hydroxybenzoic acid diglycidyl ester, and triglyceride. Glycidyl isocyanurate, spiroglycol diglycidyl ether, hydantoin compound, alicyclic epoxy resin, aliphatic epoxy resin, bisphenol A type epoxy resin, cresol novolac epoxy resin, phenol novolac epoxy resin, and epoxy equivalent of 100 to 15000 g / eq, Examples thereof include acrylic resins and fluororesins having a number average molecular weight of 1000 to 20000. Further, amide compounds such as “PrimidXL-552” (trade name) manufactured by Rohm and Haas are listed.
[0061]
Further, when the resin contained in the thermosetting powder coating has an epoxy group as a crosslinkable reactive group, examples of the curing agent include fumaric acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid and the like. Acid anhydrides such as aliphatic dibasic acid, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, polyester resins, acrylic resins and fluorine having an acid value of 1 to 200 mg KOH / g and a number average molecular weight of 1000 to 20000 Examples include resins, dicyandiamide and dicyandiamide derivatives, imidazole and imidazole derivatives, dibasic acid dihydrazide, diaminodiphenylmethane, amine compounds such as cyclic amidine compounds, and melamine resins.
[0062]
Such a curing agent is usually used in the powder coating in an amount of 0.1 to 10% by weight, preferably 0.5 to 5% by weight.
Curing catalyst
The powder coating material may contain a curing catalyst. Examples of the curing catalyst include octylic acid tin salt, zirconium salt, cobalt salt, zinc salt, lead salt, cadmium salt;
Dibutyltin dilaurate; dibutyltin malate; tin oxalate; tin naphthenate; stearic acid lead salt, tin salt, bismuth salt; acetylacetone tin;
[0063]
When such a curing catalyst is used, the curing catalyst is usually used in an amount of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, in the powder coating material.
In addition to the components described above, the powder coating material includes other components as described below within a range that does not contradict the object of the present invention, such as plasticizers, various pigments, antiblocking agents, mold release agents, weathering stabilizers, A lubricant, a heat stabilizer, a flame retardant, a filler, a surface conditioner, and the like can be added.
[0064]
In order to obtain such a powder coating containing various components, the above components may be blended, mixed, stirred, and the like.
Powder coating formation method
In the method of the present invention, the powder coating material, preferably the thermosetting powder coating material, is applied to a substrate to be coated by a method such as electrostatic spraying, fluid dipping, or electrostatic fluid dipping. A uniform film-like powder coating film (powder layer) can be formed by melting, fusing and curing the powder coating.
[0065]
Among the coating methods, the electrostatic spraying method is preferable. Although the heating conditions depend on the type of thermosetting powder coating, it is usually appropriate that the temperature of the article to be coated is 150 to 250 ° C. for 1 to 30 minutes. The thickness of the coating film is usually selected in the range of 20 to 150 μm, preferably 30 to 100 μm in terms of average film thickness. In particular, when the composite of the present invention is a coating film, the material and shape of the object to be coated are not particularly limited as long as the object can withstand the heating conditions. Examples of the material of the object to be coated include those described above, such as metal, glass, and ceramic.
[0066]
[Intermediate coating ( II ]]
The intermediate coating film (intercoat layer) (II) can employ various molding methods depending on the shape and use of the resulting composite, preferably a colored pigment-containing curable polysiloxane inorganic coating composition (colored coating). Is applied (coated) on the surface of the undercoat layer (I) or injected into a mold provided with the undercoat layer (I), followed by drying at room temperature or heat curing.
[0067]
As the coloring pigment-containing curable polysiloxane inorganic coating composition (coloring paint) for the intermediate coating film (intermediate coating layer) (II),
(A) a coloring pigment;
(B-0) curable polysiloxane inorganic polymer and, if necessary,
(C) a curing catalyst for the component (B-0)
Can be used, but in a preferred embodiment thereof,
(A) a coloring pigment;
(B) Organosiloxane (a), its partially hydrolyzed condensate (b) or curable organopolysiloxane (c) (hereinafter these are also collectively referred to as inorganic coating film forming components, organosiloxane compounds, etc.) And if necessary,
(C) a curing catalyst for the component (B)
Contains.
[0068]
That is, in the preferred embodiment, in place of the (B-0) curable polysiloxane inorganic polymer, preferably (B) "organosiloxane (ii), a partially hydrolyzed condensate thereof (b) or curable organopolysiloxane. (C) "is used.
Among these components, the inorganic coating film forming component (B) and the curing catalyst (C) for this component (B) are a photocatalyst-containing curable polysiloxane system for forming the topcoat coating film (III) described later. It is the same as what is contained in an inorganic coating composition.
[0069]
In a preferred embodiment of the present invention, both the intermediate coating layer and the topcoat coating film (overcoat layer) (III) of the composite are “organosiloxane, partially hydrolyzed condensate thereof or curable organopolysiloxane” (B ) In the presence of the curing catalyst (C) for these components (B), so that it has excellent interlayer adhesion, and the photocatalytically active substance (D ) Is included, it is considered that the composite is excellent in durability.
[0070]
The colored paint may contain a silicone (meth) acrylate copolymer (E) described later.
Hereinafter, the color pigment (A), the inorganic coating film forming component (B), the curing catalyst (C), the silicone (meth) acrylate copolymer (E), and the like will be described in order.
<Coloring pigment (A)>
As the color pigment (A) blended in the color coating for the intermediate coating film (II), conventionally known various organic and inorganic pigments can be used, and inorganic ones are preferably used.
[0071]
Examples of organic pigments include carbon black, phthalocyanine blue, and bitumen. Examples of inorganic pigments are neutral and non-reactive materials such as titanium white, bengara, barite powder, silica, tankal, talc, chalk, iron oxide powder; zinc white (ZnO, zinc oxide), lead Examples include basic (active pigments) that are basic and reactive with acidic substances in the paint, such as white, red lead, zinc dust, and lead oxide powder. Various colorants such as dyes may also be included. Such various pigments are blended in the colored paint, for example, in a total amount of 10 to 80% by weight, preferably 20 to 60% by weight.
[0072]
<Curable polysiloxane inorganic polymer (B-0),
Organosiloxane, its partially hydrolyzed condensate
Or curable organopolysiloxane (B)>
As the resin component for forming the coating film, a polysiloxane inorganic polymer represented by the following formula [I] can be used. In a preferred embodiment thereof, an organosiloxane represented by the following formula [II] (organo (Silane) (a) or a partially hydrolyzed condensate thereof (b) and a polyorganosiloxane (curable organopolysiloxane) (c) represented by the following formula [III] are used, In a preferred embodiment, (A) and / or (B) and (C) are used in combination.
[0073]
As the polysiloxane inorganic polymer [I], a curable polymer represented by the following formula [I] as described in JP-A-7-60184 [0013] to [0015] can be used.
[0074]
[Chemical 1]

[0075]
(In the formula [I], R¹~ R⁶Each independently represents a hydrogen atom; an alkyl group having 1 to 15 carbon atoms, preferably 1 to 10 which may be linear or branched; and an aryl group. n shows the integer of 1-100. )
The weight average molecular weight (Mw) of the curable polysiloxane inorganic polymer [I] is usually 100 to 20000, preferably 200 to 10,000.
[0076]
When the crosslinkable reactive group is a hydroxyl group, the hydroxyl value is desirably in the range of 1 to 200 mgKOH / g, preferably 20 to 140 mgKOH / g. If the hydroxyl value is less than 1 mgKOH / g, crosslinking is insufficient. However, when the amount exceeds 200 mgKOH / g, the crosslinking density becomes too high and the flexibility tends to decrease.
Examples of the alkyl group include a methyl group, an ethyl group, an n, i-propyl group, and an n, i, t-butyl group. Examples of the aryl group include a phenyl group and a naphthyl group.
[0077]
Specific examples of the curable polysiloxane inorganic polymer represented by the formula [I] include polyhydroxysiloxane, polymethoxysiloxane, polyethoxysiloxane, polybutoxysiloxane, etc., and these may be used alone or in combination. May be used.
The coating material containing the curable polysiloxane inorganic polymer [I] can contain a compound capable of forming a crosslink with the curable organopolysiloxane, if necessary. As the compound capable of forming this crosslink, for example, a hydroxyl group-containing compound, an amino resin, a polyisocyanate compound, a blocked isocyanate compound, an epoxy resin, and the like can be used.
[0078]
Specific examples of such a compound capable of forming a crosslink with the curable polysiloxane inorganic polymer [I] include those described in JP-A-7-60184, columns [0016] to [0019].
In the present invention, instead of the component (B-0), that is, the curable polysiloxane inorganic polymer [I] represented by the formula [I], the inorganic coating film-forming component (B), that is, the “organosiloxane ( (B) A partially hydrolyzed condensate (b) or a curable organopolysiloxane (c) (these are collectively referred to as an organosiloxane compound (B)) ”is preferably used.
[0079]
Among these components (a) to (c), the organosiloxane (a) is a hydrolyzable organosilane compound described in JP-A 2000-186250 [0021] to [0024] or a hydrolysis thereof. Things can be used.
Organosiloxane ( I ) Or its partially hydrolyzed condensate ( B )
This organosiloxane (also called hydrolyzable organosilane compound, alkoxysilane, organosilane, etc.) (a)
Formula [II]: R^Ten _nSiX_4-n・ ・ ・ ・ ・ [II]
(In the formula [II], R^TenRepresents the same or different monovalent substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms, n represents an integer of 0 to 3, and X represents a hydrolyzable group. ).
[0080]
In the above formula [II], R^TenRepresents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and examples of the substituent include a halogen group, a glycidoxy group, a mercapto group, an epoxy group, and an amino group.
Examples of such hydrocarbon groups include alkyl groups such as methyl, ethyl, n, i-propyl, and n, i, t-butyl groups; aryl groups such as phenyl groups; cyclopentyl groups, cyclohexyl groups, and the like. Other than these, a vinyl group, chloromethyl group, γ-chloropropyl group, 3,3,3-trifluoropropyl group, γ-methacryloxypropyl group, γ-glycidoxypropyl group, γ-mercaptopropyl Group, 3,4-epoxycyclohexylmethyl group, γ-aminopropyl group and the like.
[0081]
Examples of the hydrolyzable group X include an alkoxy group, an acetoxy group, an oxime group, and an aminoxy group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms. Is preferred.
In the formula, n represents the number of functional groups, and specific examples of monosiloxane, bifunctional, trifunctional, and tetrafunctional organosiloxane (alkoxysilanes) [II] corresponding to n = 0 to 3 are as follows. The thing like this is mentioned.
[0082]
That is, when n = 0, examples include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.
When n = 1, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxy Silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacrylic Examples include loxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane.
[0083]
When n = 2, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacrylate. Examples include loxyprovir methyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, and γ-aminopropylmethyldiethoxysilane.
[0084]
Further, when n = 3, trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, dimethylisobutylmethoxysilane, and the like can be given.
Among the above organosiloxanes (alkoxysilanes), tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, and γ-glycidoxy are easily available. Propyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane and the like are preferably used.
[0085]
These organosiloxanes (alkoxysilanes) may be used alone or in combination of two or more.
The partially hydrolyzed condensate (b) of the organosiloxane (a) in the above formula [II], 1 to n of the hydrolyzable groups X of (4-n) are hydrolyzed to produce hydroxyl groups (- OH) is a partial hydrolyzate produced by dehydration condensation on the average of about 1 to 3 to form linkages with siloxane bonds. The number average molecular weight (Mn) of the partially hydrolyzed condensate (b) is usually about 100 to 2000, preferably about 200 to 1000.
[0086]
Curable polyorganosiloxane ( C )
Curable polyorganosiloxane (Curable organopolysiloxane) (C)
Average composition formula [III]: R²⁰ _aSi (OH)_bO_{(4-ab) / 2}・ ・ ・ ・ ・ [III]
(In the formula [III], R²⁰Is R^TenAnd the same or different monovalent substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms, a and b are 0.2 ≦ a ≦ 2, 0.0001 ≦ b ≦ 3, respectively. , A + b <4. )
And is a polyorganosiloxane [III] containing a silanol group (≡Si—OH) in the molecule.
[0087]
The curable organopolysiloxane (c) is a silanol group-containing polyorganosiloxane, which is cured by condensation reaction with the organosiloxane (a) component, which is a base polymer having a hydrolyzable group as a functional group for the curing reaction. It also has a role as a cross-linking agent for forming a three-dimensional cross-link in the film, and is an effective component for absorbing cracks due to curing shrinkage of the organosiloxane (A) component and preventing the occurrence of cracks.
[0088]
R in the above average composition formula [III] representing this curable organopolysiloxane (c), that is, silanol group-containing polyorganosiloxane (c)²⁰Is not particularly limited, and R in the formula [II]^TenAre the same, but preferably an alkyl group having 1 to 4 carbon atoms, phenyl group, vinyl group, r-glycidoxypropyl group, r-methacryloxypropyl group, r-aminopropyl group, 3, Substituted hydrocarbon groups such as 3,3-trifluoropropyl group, more preferably methyl group and phenyl group. A and b in the above [III] are numbers satisfying the above relationship, respectively, and when a and b exceed 3, cracks may occur in the low-temperature curable inorganic paint, and a exceeds 2 and 4 In the following cases or when b is less than 0.0001, curing may not proceed well.
[0089]
Such a curable organopolysiloxane (c) is not particularly limited. For example, methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, or a corresponding alkoxysilane 1 It can be obtained by hydrolyzing a seed or a mixture of two or more kinds with a large amount of water by a known method.
[0090]
In the production of the curable polyorganosiloxane (c), when alkoxysilane is hydrolyzed by a known method, a slight amount of alkoxy groups may remain without being hydrolyzed. That is, a polyorganosiloxane in which a silanol group and a very small amount of alkoxy group coexist may be obtained, but such a polyorganosiloxane may be used in the present invention.
[0091]
The weight average molecular weight (Mw) of such curable organopolysiloxane [III] is usually 100 to 20000, preferably 300 to 10,000.
In the present invention, the curable polysiloxane inorganic polymer (B-0) represented by the above formula [I], the organosiloxane compound (B) as an inorganic coating film forming component, or the like is the intermediate coating film (II). In the colored pigment-containing curable polysiloxane inorganic coating composition (colored coating) for use, the solid content in terms of total condensation compound (also referred to as solid content) is usually 10 to 80% by weight, preferably 20 to 70% by weight. It is desirable to be included in the amount of. When the component (B-0) or (B) is contained in the colored paint in the above-mentioned amount, the coating film properties, durability, and corrosion resistance tend to be excellent.
[0092]
In the present invention, in 100 parts by weight of the organosiloxane compound, that is, the inorganic coating film-forming component (B), the organosilane (I) represented by the formula [II] or a partially hydrolyzed condensate thereof (b), and The curable organopolysiloxane (C) represented by the formula [III] may be contained in an arbitrary amount ratio.
These inorganic coating film forming components (B) are usually used in an amount of 10 to 80% by weight, preferably 20 to 70% by weight, in the colored coating for the intermediate coating film (II).
[0093]
<Curing catalyst (C) for component (B-0) or (B)>
The curing catalyst (C) for the component (B) is not particularly limited. For example, carboxylic acid metal salts, amines, acids, alkali catalysts, titanium compounds, halogenated silanes, and the like can be used. Carboxylic acid metal salts such as titanate, tin octylate, dibutyltin laurate;
Amine salts such as dibutylamine-2-hexoate and dimethylamine acetate;
Amine-based silane coupling agents such as N-β-aminoethyl-γ-aminopropyltrimethoxysilane;
Acids such as p-toluenesulfonic acid, phthalic acid, and hydrochloric acid are used.
[0094]
Due to the action of the catalyst (C), the hydrolyzable groups in the above formulas [I], [II] and [III] are hydrolyzed, and the resulting silanol groups (≡Si—OH) are dehydrated and condensed to form siloxane bonds. It is considered that (Si—O—Si) is generated and the colored paint (colored pigment-containing curable polysiloxane inorganic paint composition) is solidified.
These catalysts (C) are usually added in an amount of 0.001 to 10% by weight, preferably 0.005 to 5% by weight, in the colored coating material for the intermediate coating film (II). B-0) Preferably used in an amount of 0.001 to 5 parts by weight, preferably 0.005 to 2 parts by weight, based on 100 parts by weight of component (B).
[0095]
<Coloring pigment-containing curable polysiloxane system
Production and curing of inorganic coating composition (colored coating)>
In order to produce such a colored paint (color pigment-containing curable polysiloxane inorganic coating composition) for the intermediate coating film (II), the following may be carried out.
That is,
(a): the above formula [II], that is,
Formula [II]: R^Ten _nSiX_4-n・ ・ ・ ・ ・ [II]
(In the formula [II], R^TenRepresents the same or different monovalent substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms, n represents an integer of 0 to 3, and X represents a hydrolyzable group. )
In colloidal silica obtained by dispersing hydrolyzable organosilane [II] represented by formula (1) in an organic solvent or water, 0.001 to 5 mol of water, preferably 1 to 1 mol of hydrolyzable group X A silica-dispersed oligomer solution of an organosilane obtained by partially hydrolyzing and polycondensing the hydrolyzable organosilane [II] using an amount of 0.01 to 3 mol,
(b): Average composition formula [III]: R²⁰ _aSi (OH)_bO_{(4-ab) / 2}・ ・ ・ ・ ・ [III]
(In the formula [III], R²⁰Is R^TenAnd the same or different monovalent substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms, a and b are 0.2 ≦ a ≦ 2, 0.0001 ≦ b ≦ 3, respectively. , A + b <4. )
And a polyorganosiloxane [III] containing silanol groups (≡Si—OH) in the molecule,
Any one of the above (that is, either (a) or (b)) may be used alone, but in the present invention, both (a) and (b) are mixed (blended) and used. Is desirable.
[0096]
(c): If necessary, a curing catalyst (C) may be added to the colored paint.
Further, the curing catalyst (C) used as necessary, that is, the hydrolysis / polycondensation catalyst (C) is usually obtained by combining the silica-dispersed oligomer solution (a) and the polyorganosiloxane (b) with the above-mentioned. It is added when mixing.
The curing catalyst (C) may be added during the preparation of the above “silica dispersed oligomer solution of organosilane” (a), or may be added to the polyorganosiloxane (b). ) And (b) may be added to the mixture obtained.
[0097]
The addition / mixing of the curing catalyst (C) is preferably performed immediately before use because it may reduce the stability of the polyorganosiloxane oil (b). In other words, it is desirable to mix (a), (b) and (C) when forming the intermediate coating (II) on the surface of the undercoat coating (I).
Moreover, in the present invention, (d): the colloidal silica of the silica-dispersed oligomer solution preferably contains 5 to 95% by weight, preferably 10 to 90% by weight, of silica as a solid content.
[0098]
In addition, at least 50 mol%, preferably 50 to 90 mol% of the hydrolyzable organosilane [II] is an organo (n = 1) in the hydrolyzable organosilane [II] represented by the formula [II]. Silane is desirable.
In the present invention, (e): when the total of the silica-dispersed oligomer solution (a) and the polyorganosiloxane (b) is 100 parts by weight, both (a) and (b) The silica-dispersed oligomer solution (a) is usually used in an amount of 1 to 99 parts by weight, preferably 5 to 95 parts by weight, and the polyorganosiloxane (b) is used as the balance. It is desirable to use it in an amount of 99 to 1 part by weight, preferably 95 to 5 parts by weight.
[0099]
The addition / mixing time of the color pigment (A) is not particularly limited, but it is desirable to add the color pigment (A) immediately before use and use the paint in a state where the color pigment (A) is well dispersed.
<Optional component>
In the present invention, the colored pigment-containing curable polysiloxane inorganic coating composition (colored coating) for forming the intermediate coating film (II) includes the above-mentioned color pigment (A), coating film-forming component component (B) and In addition to the curing catalyst (C) used as necessary, other components as described below, for example, a photocatalyst-containing inorganic coating for forming the top coat film (III) described below, are included within the scope of the present invention. Photocatalyst for activating cured coating film (D), silicone (meth) acrylate copolymer (E) and its curing catalyst, inorganic binder (F), solvent, plasticizer, extender pigment, antiblocking agent, release agent Molding agent, weather resistance stabilizer, lubricant, heat stabilizer, flame retardant, filler, dispersant, antifoaming agent, leveling agent, anti-settling agent, thickener, dehydrating agent, surfactant, silane coupling agent, etc. Can be added.
[0100]
In addition, the addition and mixing | blending time of this photocatalyst (D) for cured coating film activation are not specifically limited.
When this coloring paint contains the silicone (meth) acrylate copolymer (E) described in detail below, the copolymer (E) is converted into the above (A), (B), ( In a total of 100 parts by weight of C) and (E), usually 0 to 50 parts by weight, preferably 0 to 40 parts by weight,
Moreover, it is desirable to contain in the amount of 0-30 weight% normally in a coloring paint, Preferably it is 0-10 weight%.
[0101]
When the component (E) is contained in the above amount, adhesion, coating film properties, and coating workability tend to be improved.
Examples of the inorganic binder (F) include hydrolyzate of organosilica sol, reaction product of hydrolyzate of organosilica sol and colloidal silica, and the like.
When this colored paint contains an inorganic binder (F), the inorganic binder (F) is in a total of 100 parts by weight of the above (A), (B), (C), (E), (F). In an amount of usually 0.1 to 60 parts by weight, preferably 0.5 to 30 parts by weight,
Further, it may be contained in the colored paint for the intermediate coating film (II) in an amount of usually 0.1 to 40% by weight, preferably 0.5 to 30% by weight.
[0102]
In order to obtain such a colored paint for forming the intermediate coating film (II), the above-mentioned components may be blended and mixed.
Next, a colored paint for forming the intermediate coating film (II), a silicone (meth) acrylate copolymer (E) that may be blended in a photocatalyst-containing inorganic paint for forming the top coat film (III) described later, and The curing catalyst will be described in detail.
[0103]
Silicone (meth) acrylate copolymer (E) and curing catalyst
<Silicone (meth) acrylate copolymer (E)>
When the silicone (meth) acrylate copolymer (E) is cured, a curing catalyst (curing catalyst) described later is used in a preferred embodiment.
The uncured silicone (meth) acrylate copolymer (acrylic silicone resin) (E) is moisture curable at room temperature in the presence of a curing catalyst, for example, an acid or an organometallic catalyst, which will be described later. It is used as a moldable paint resin.
[0104]
As the silicone (meth) acrylate copolymer (E), conventionally known ones can be widely used. For example, among (a3-1): silanol group (≡Si—OH) and hydrolyzable silyl group An organoalkoxysilane containing one or both of these and a radically polymerizable unsaturated group (eg, carbon-carbon double bond (C = C));
(b3-1): a “vinyl monomer” copolymerizable with the above organoalkoxysilane (a3-1), such as (meth) acrylic acid, (meth) acrylic acid derivatives, etc.
A copolymer (acrylic silicone resin) obtained by radical polymerization is exemplified.
[0105]
The radical polymerizable organoalkoxysilane (a3-1) contains either or both of a silanol group and a hydrolyzable silyl group and a polymerizable carbon / carbon double bond. The following monomers described in JP-A-11-279480, columns [0032] to [0045] are exemplified.
That is, examples of the organic alkoxysilane (a3-1) (hereinafter referred to as monomer (A-1)) containing a polymerizable double bond and a silanol group or hydrolyzed silyl group bonded to a carbon atom include the following: Represented by Formula (3), specifically, for example, as shown in Formulas (3-1) to (3-11);
Represented by the following formula (4), specifically, for example, as shown in formulas (4-1) to (4-9);
Etc.
[0106]
[Chemical 2]

[0107]
(In formula (3), R¹Represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. R²Represents a monovalent group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms and an aralkyl group having 7 to 10 carbon atoms. R¹ Or R² When two or more exist, they may be the same or different. R^Five Represents a hydrogen atom or a methyl group. a represents an integer of 0 to 2. )
[0108]
[Chemical Formula 3]

[0109]
Moreover, as said monomer (A-1), what is represented by following formula (4) and specifically shown to Formula (4-1)-(4-9) is mentioned.
[0110]
[Formula 4]

[0111]
(In formula (4), R¹ , R² , R^Five , A are the same as above. n is an integer of 1-12. )
[0112]
[Chemical formula 5]

[0113]
Examples of the vinyl monomer (b3-1) copolymerizable with the organoalkoxysilane (a3-1) include (meth) acrylic acid described in JP-A-11-279480, columns [0049] to [0050] and / or Or the derivative | guide_body etc. are mentioned.
Examples of the vinyl monomer (b3-1) include (meth) acrylic acid alkyl esters or amides in which a part of the hydrogen atoms in the alkyl group may be substituted with hydroxyl groups, halogen groups, or the like. ,
Specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (Meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, palmitoyl (meth) acrylate, stearyl (meth) acrylate, octadecanoyl (meth) acrylate, oleyl (meth) acrylate, icosanoyl (meth) acrylate,
Benzyl (meth) acrylate, cyclohexyl (meth) acrylate,
Trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, (meth) acrylonitrile, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, (Meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methyl (meth) acrylamide (meth) acryloylmorpholine, a macromonomer. AS-6, AN-6, AA-6, AB-6, AK-6 "(trade name) and other compounds (manufactured by Toa Gosei Chemical Co., Ltd.), 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl ( Meta Acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl vinyl ether, N- methylol (meth) acrylamide,
4-hydroxystyrene vinyl toluene, 4-hydroxystyrene, acrylic acid ester oligomer having a hydroxyl group at the terminal, polypropylene glycol methacrylate, polyethylene glycol monomethacrylate, polyethylene glycol polypropylene glycol methacrylate, polypropylene glycol monoacrylate, polyethylene glycol monoacrylate and glycerol monomethacrylate , Hydroxyalkyl esters of (meth) acrylic acid such as N-methylol (meth) acrylamide; ε-caprolactone-modified hydroxyalkyl vinyl copolymer compound obtained by reaction of a hydroxyl group-containing compound and ε-caprolactone (trade name “ "Placcel FA-1, FA-4, FM-1, FM-4", Daicel Chemical Industries, Ltd. ), Polycarbonate-containing vinyl compounds (trade name “HEAC-1” manufactured by Daicel Chemical Industries, Ltd.), phosphate esters such as condensation products of hydroxyalkyl esters of (meth) acrylic acid and phosphoric acid or phosphate esters Examples include group-containing (meth) acrylic compounds, (meth) acrylates containing urethane bonds and siloxane bonds.
[0114]
In addition, aromatic hydrocarbon vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene, vinyltoluene; maleic acid, fumaric acid, itaconic acid, (meth) acrylic acid, etc. Unsaturated carboxylic acids, salts of these alkali metal salts, ammonium salts, amine salts, etc .; acid anhydrides of unsaturated carboxylic acids such as maleic anhydride, these acid anhydrides and linear or branched having 1 to 20 carbon atoms Esters of unsaturated carboxylic acids such as diesters or half esters with chain alcohols or amines; vinyl esters and allyl compounds such as vinyl acetate, vinyl propionate and diallyl phthalate; vinyls containing amino groups such as vinyl pyridine and aminoethyl vinyl ether Compounds: Itaconic acid diamide, crotonic acid amide Amide group-containing vinyl compounds such as maleic acid diamide, fumaric acid diamide, N-vinylpyrrolidone; 2-hydroxyethyl vinyl ether, methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, fluoroolefin maleimide And other vinyl compounds such as N-vinylimidazole and vinylsulfonic acid. These may be used alone or in combination of two or more.
[0115]
These monomers (including macromonomers) may be used alone or in combination of two or more.
In order to copolymerize such various monomers, an azo radical polymerization initiator such as azobisisobutyronitrile (AIBN) is used in accordance with the method described in JP-A-11-279480 [0059] column. Solution polymerization or the like may be performed in the presence, if necessary, in the presence of a solvent, preferably in the presence of a non-aqueous solvent capable of preventing hydrolysis of the hydrolyzable monomer. In the polymerization reaction, a chain transfer agent or the like may be used. Examples of the non-aqueous solvent include hydrocarbons such as toluene, xylene, n-hexane, and cyclohexane; acetate esters; ketones; alcohols and the like.
[0116]
Thus, the curable silicone (meth) acrylate copolymer (acrylic silicone resin) (E) obtained by copolymerizing various monomers is
Formula (1):
[0117]
[Chemical 6]

[0118]
(In formula (1), R¹ Represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R² Represents a monovalent group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms and an aralkyl group having 7 to 10 carbon atoms. R¹ Or R² When two or more exist, they may be the same or different. a represents an integer of 0 to 2. And an acrylic copolymer having at least two silanol groups (hydroxysilyl groups) or hydrolyzable silyl groups bonded to carbon atoms.
[0119]
Such a curable silicone (meth) acrylate copolymer (E) has a number average molecular weight (Mn) of usually 1000 to 18000, preferably 200 to 15000.
The hydroxyl value is desirably in the range of 1 to 200 mg KOH / g, preferably 20 to 140 mg KOH / g. When this hydroxyl value is in the above range, the crosslinking density is moderate, and there is a tendency that a composite, particularly a coating film, having excellent physical properties such as flexibility can be obtained.
[0120]
The curable silicone (meth) acrylate copolymer preferably has a Tg of 0 to 150 ° C., preferably 0 to 100 ° C. When the Tg is in such a range, it is liquid at room temperature, It becomes a solid, easy to use in paints, has a moderate softening point, is easy to handle, and has good flowability during painting.
<Curing catalyst (b3)>
The curing catalyst (b3) for the curable silicone (meth) acrylate copolymer (E) is not particularly limited, and conventionally known catalysts can be used. For example, JP-A-11-279480 [0065] to [0069] ] Column etc. can be used.
[0121]
As such a curing catalyst (b3), for example, a combined product of an organic carboxylic acid and an organic amine, an organic phosphate ester, an organometallic compound, and the like can be given. Specific examples of the organic carboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, pentanoic acid, hexanoic acid, octylic acid, 2-ethylhexanoic acid, decanoic acid, dodecanoic acid, benzoic acid, phthalic acid, fumaric acid, malein Examples include acids, succinic acid, itaconic acid, and anhydrides thereof. Specific examples of the organic amine include primary amines such as laurylamine, tertiary amines such as triethylamine and dimethyllaurylamine, and cyclic amines such as morpholine. As a combination of the organic carboxylic acid and the organic amine, considering the balance between curing activity and pot life, for example, acetic acid / dimethyl lauryl amine, hexanoic acid / lauryl amine, 2-ethylhexanoic acid / dimethyl lauryl amine, A combination of 2-ethylhexanoic acid / laurylamine is preferred.
[0122]
Specific examples of the organic phosphate include di (2-ethylhexyl) monophosphate, di (2-ethylhexyl) diphosphate, and the like. From the viewpoint of the balance between curing activity and pot life, di (2-ethylhexyl) monophosphate is preferable, and this organic phosphate may be used alone or in combination with the above organic amine. In this case, preferred combinations are di (2-ethylhexyl) monophosphate / dimethyllaurylamine, di (2-ethylhexyl) monophosphate / laurylamine, and more preferably di (2-ethylhexyl) monophosphate / dimethyllaurylamine. It is. The above combination substances may be used alone or in combination of two or more.
[0123]
Examples of the organometallic compound include an organic tin compound and an aluminum chelate compound. Examples of the organic tin compound include dioctyltin bis (2-ethylhexyl malate), dioctyltin oxide or a condensate of dibutyltin oxide and silicate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin distearate, dibutyltin diacetylacetate Nert, dibutyltin bis (ethylmalate), dibutyltin bis (butylmalate), dibutyltin bis (2-ethylhexylmalate), dibutyltin bis (oleylmalate), stannous octoate, tin stearate, di-n-butyl Examples thereof include tin laurate oxide. Dibutyltin bisisononyl-3-mercaptopropionate, dioctyltin bisisononyl-3-mercaptopropionate, octylbutyltin bisisononyl-3-mercaptopropionate, dibutyltin bisisooctylthioglucorate, dioctyltin bisisooctyl Examples thereof include organic tin compounds having a sulfur atom in the molecule such as thioglucolate and octylbutyltin bisisooctylthioglucolate.
[0124]
Examples of the aluminum chelate compound include ethyl acetoacetate aluminum diisopropylate, aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate), aluminum monoacetylacetonate bis (ethylacetonate), alkylacetylacetate aluminum diisopropylate Etc. Among these, when aluminum tris (ethyl acetoacetate) and aluminum tris (acetylacetonate) are blended with isocyanate, the balance of storage stability and pot life is good, and the contact angle of the coating is reduced. It is preferable from the point.
[0125]
The curing catalyst may be used alone or in combination of two or more.
In the present invention, the curing catalyst (b3) is usually 0.001 to 10 parts by weight, preferably 0.01 to 100 parts by weight with respect to 100 parts by weight of the curable silicone (meth) acrylate copolymer (E). Used in an amount of 8 parts by weight. When the curing catalyst (b3) for the silicone (meth) acrylate copolymer (E) is used in such an amount, the hydrolyzable silyl group of the silicone (meth) acrylate copolymer is efficiently hydrolyzed. It is considered that a hydroxysilyl group is formed, and a crosslinkable reactive group (OH) causes a dehydration reaction to efficiently form a siloxane bond (crosslinking).
[0126]
In the present invention, together with such a silicone (meth) acrylate copolymer (E) and a curing catalyst (b3) for silicone (meth) acrylate copolymer, JP-A-11-279480, which becomes a coating film forming component, is further disclosed. Alkoxysilane (2) other than the above described in the columns [0064] to [0077] and / or a partially hydrolyzed condensate thereof, a silane coupling agent described in the column [0080] (eg, aminosilane, epoxysilane and These reaction products) and hydrolyzable ester compounds may be used.
[0127]
Examples of the alkoxysilane (2) include:
What is represented by following formula (2) is mentioned.
(R^Three O)_4-b -Si- (R^Four )_b   (2)
(In formula (2), R^ThreeRepresents a monovalent hydrocarbon group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms and an aralkyl group having 7 to 10 carbon atoms. R^FourRepresents a monovalent hydrocarbon group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms and an aralkyl group having 7 to 10 carbon atoms. R^ThreeAnd / or R^FourWhen two or more exist, they may be the same or different. b represents an integer of 0 to 2. )
Specific examples of the alkoxysilane (2) include tetraalkyl silicates such as tetramethyl silicate, tetraethyl silicate, tetra n-propyl silicate, tetra i-propyl silicate, tetra n-butyl silicate and tetra i-butyl silicate. Methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, octadecyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, methyltrisec-octyloxysilane, methyltriphenoxysilane, methyltri Examples include isopropoxysilane and methyltributoxysilane. These also function as silane coupling agents.
[0128]
<Intermediate coating ( II ) Formation Method>
By coating and curing such a colored paint to form an intermediate paint film (II) on the surface of the undercoat paint film (I), depending on the film thickness, composition, etc. The base coating film (I) is coated (applied) on the surface or filled on the base coating film (I) provided in the mold, and usually at a temperature of 30 to 250 ° C., preferably 80 to 200 ° C. Heating the colored paint for about 0.05 to 3 hours, preferably about 0.1 to 1.5 hours, or
What is necessary is just to hold | maintain at normal temperature for 1 to 120 hours, Preferably it is 5-72 hours, and if it heats or hold | maintains at normal temperature, it will harden | cure and a gel film will be formed.
[0129]
More specifically, in the present invention, in order to form the intermediate coating film (II) on the surface of the substrate to be coated as described above, an electrostatic spraying method, a fluid immersion method, an electrostatic fluid immersion method, a brush application Applying a colored paint to a substrate to be coated by a conventionally known method such as a roll coat method, a flow coat method, an air spray spray method, an airless spray method, and then drying the color paint at room temperature or necessary A uniform film-like intermediate coating film (II) can be formed by heating and curing.
[0130]
Among the coating methods, the electrostatic spraying method is preferable. In the case of heat curing, although it depends on the kind of coating film forming component contained in the colored coating for forming the intermediate coating film (II), it is usually suitable at 140 to 200 ° C. for 5 to 40 minutes.
In the intermediate coating film (II) obtained by curing in this way, among the inorganic coating film forming component used, the silicone (meth) acrylate copolymer, etc., for example, in the inorganic coating film forming component, Formation of coating film in colored paint due to intermolecular cross-linking such as dehydration condensation between hydroxyl groups (OH) generated by hydrolysis of alkoxysilyl groups contained in silicone (meth) acrylate copolymers, etc. It is believed that the component is cured.
[0131]
The thickness of the intermediate coating film (II) is usually 5 to 150 μm, preferably 10 to 50 μm in terms of average film thickness.
[Top coat film (III) ]
The top coat film (III) is provided on the intermediate coating film (II).
Such a top coat coating (III) is obtained by applying a photocatalyst-containing curable polysiloxane inorganic coating composition (photocatalyst-containing inorganic coating) on the intermediate coating (II) serving as an intermediate coating layer. It is obtained by normal drying or heat curing, preferably heat curing.
[0132]
As the photocatalyst-containing inorganic paint, the same inorganic paint film-forming component (B) as that blended in the color pigment-containing curable polysiloxane inorganic paint composition (color paint) for forming the intermediate paint film (II) is used. ) And, if necessary, the curing catalyst (C), and “a photocatalyst (photocatalyst) for activating a cured coating film mainly composed of titanium oxide” (D) is used.
[0133]
That is, as the photocatalyst-containing inorganic paint for the top coat layer,
(D) a photocatalyst (photocatalyst) for activating a cured coating film containing titanium oxide as a main component,
(B-0) curable polysiloxane inorganic polymer and, if necessary,
(C) a curing catalyst for the component (B-0)
Can be used, but in a preferred embodiment thereof,
(D) a photocatalyst (photocatalyst) for activating a cured coating film containing titanium oxide as a main component,
(B) Organosiloxane (a), its partially hydrolyzed condensate (b) or curable organopolysiloxane (c), and if necessary,
(C) a curing catalyst for the component (B)
The one containing is used.
[0134]
That is, in the preferred embodiment, in the same manner as in the case of the colored coating for the intermediate coating film (II), instead of the (B-0) curable polysiloxane inorganic polymer, preferably (B) “organosiloxane (a) , Partially hydrolyzed condensate (b) or curable organopolysiloxane (c) ”.
In a preferred embodiment of the present invention, “organosiloxane, partially hydrolyzed condensate thereof or curable organopolysiloxane” (B) is used for curing for these components in both the intermediate layer and the overcoat layer of the composite. Since the polysiloxane inorganic polymer formed by reaction and curing in the presence of the catalyst is contained, it is considered that the interlayer adhesion is excellent and the durability (resistance) against the decomposition action of the coating film by the photocatalyst is considered.
[0135]
The photocatalyst-containing inorganic paint includes a photocatalyst (D) for activating a cured coating film, a coating film forming component (B) and, if necessary, a curing catalyst (C) as long as it does not contradict the purpose of the present invention. Other components such as the following, for example, the silicone (meth) acrylate copolymer (E) and its curing catalyst, an organosilica sol as an inorganic binder (F), a solvent, a plasticizer, a color pigment (A), Extender, antiblocking agent, mold release agent, weathering stabilizer, lubricant, heat stabilizer, flame retardant, filler, leveling agent, antisettling agent, thickener, dehydrating agent, surfactant, silane coupling agent Etc. can be added.
[0136]
In such a photocatalyst-containing inorganic coating, when the total of components (B), (C), (D), and (E) is 100 parts by weight,
Component (B) (total condensation compound in terms of solid content, that is, in terms of solid content, the same applies hereinafter) in an amount of 20 to 80 parts by weight, preferably 30 to 70 parts by weight,
Component (C) in an amount of 0 to 10 parts by weight, preferably 0.01 to 5 parts by weight, and
Component (D) in an amount of 20 to 80 parts by weight, preferably 30 to 70 parts by weight,
It is desirable to contain component (E) in an amount of 0 to 50 parts by weight, preferably 0 to 40 parts by weight.
[0137]
In the photocatalyst-containing inorganic coating, the component (B) is 0.01 to 50% by weight, preferably 0.1 to 30% by weight,
Component (C) in an amount of 0 to 10% by weight, preferably 0.01 to 5% by weight, and
Component (D) in an amount of 0.01 to 50% by weight, preferably 0.1 to 30% by weight,
It is desirable to contain the component (E) in an amount of 0 to 20% by weight, preferably 0 to 10% by weight (provided that the total of all components in the paint is 100% by weight).
[0138]
Hereinafter, the photocatalyst (D) for activating the cured coating film contained in the photocatalyst-containing curable polysiloxane inorganic coating composition (photocatalyst-containing inorganic paint) will be mainly described.
<Photocatalyst (D) for activating cured coating film>
As the photocatalyst (D) for activating the cured coating film, titanium oxide (TiO) is contained in the component (D).₂) In the amount of 50 to 100% by weight, preferably 70 to 100% by weight, is preferably used in view of high photocatalytic activity and safety.
[0139]
Such an amount of titanium oxide (PWC (%)) is usually 1 to 99% by weight when the total of titanium oxide and inorganic polymer (cured product) contained in the topcoat coating film (III) is 100% by weight. %, Preferably 20 to 80% by weight, more preferably 30 to 70% by weight. When the blending amount of titanium oxide is in the above range, it is excellent in stain resistance, excellent in coating film properties such as durability, surface hardness, and adhesion, and there is a tendency that cracks do not occur in the coating film during curing.
[0140]
Further, the photocatalyst (D) for activating the cured coating film is contained in the cured topcoat coating film (III) in a total amount of 20 to 80% by weight, preferably 30 to 70% by weight. It is desirable.
The photocatalyst (D) for activating the cured coating film is usually contained in the photocatalyst-containing inorganic coating used in an amount of 0.01 to 50% by weight, preferably 0.1 to 30% by weight. It is desirable.
[0141]
In addition to the titanium oxide, the photocatalyst for activating the cured coating film (D) may contain other substances having photocatalytic activity. No. 1659, JP-A No. 2000-42480, and the like can be widely used, and various metal oxides and sulfides can be used, and various metal oxides are preferable.
[0142]
Examples of the oxide include iron oxide, tungsten oxide, zirconium oxide, tin oxide, bismuth oxide, ruthenium oxide, zinc oxide, strontium titanate, cadmium oxide, indium oxide, silver oxide, manganese oxide, copper oxide, and vanadium oxide. And various metal chalcogenites (selenium and tellurium compounds), and mixtures thereof. These substances used as a photocatalyst for activating a cured coating film, including titanium oxide, have a property of easily adsorbing surface hydroxyl groups because metal elements and oxygen are present on the surface.
[0143]
Examples of the sulfide include cadmium sulfide, zinc sulfide, copper sulfide, molybdenum sulfide, tungsten sulfide, antimony sulfide, and bismuth sulfide.
These may be used alone or in combination of two or more.
Among them, titanium oxide (titanium dioxide, TiO₂) Is harmless, chemically stable, and available at low cost.
[0144]
The titanium oxide will be described in detail. In the present invention, any of anatase type, rutile type and brookite type can be used as the titanium oxide. From the viewpoint of photocatalytic activity, anatase type and rutile type are preferable, and further anatase type. Is desirable. Rutile-type titanium oxide can be sintered at high temperatures and can provide a coating film with excellent strength and wear resistance, but anatase-type titanium oxide is commercially available as a sol in which extremely fine particles are dispersed. Therefore, there is an advantage that it can be easily obtained and a very thin coating film can be easily formed.
[0145]
As these photocatalysts for cured coating film activity, those having an average particle diameter of usually 0.001 μm (1 nm) to 1 μm, preferably 7 nm to 250 nm, more preferably 7 nm to 50 nm, and particularly preferably 7 nm to 20 nm are preferable.
Moreover, among the photocatalysts having such particle diameters, anatase type titanium dioxide particles are desirable. Moreover, among the photocatalysts having such particle diameters, anatase type titanium dioxide particles are desirable.
[0146]
In addition, since the photocatalytic activity of the topcoat coating film (III) becomes stronger as the average particle size of the photocatalytic activity photocatalyst becomes smaller, and a coating film with excellent transparency can be obtained, an intermediate coating film (intermediate layer) ) A laminated coating film exhibiting the colorability of (II) can be formed, and a coating film rich in color variations can be formed.
In general, the lower the concealability of the topcoat film (III), the higher the UV transmittance. Under long-term exposure, the intermediate coating film is activated by the photocatalytic activity contained in the topcoat film (III). (Intermediate layer) (II) and top coat film (overcoat layer) (III) may cause delamination, but in the case of this coating layer system, the inorganic component of the intermediate layer (II) Since it is designed to be very high, it can withstand the photocatalytic activity contained in the top coat film (III) for a long period of time.
[0147]
In particular, from the viewpoint of contamination resistance, durability, color, and gloss stability, it is desirable to use one having the smallest average particle diameter within the above average particle diameter range.
Examples of such a cured coating film active photocatalyst include trade name “ST-01” (manufactured by Ishihara Techno Co., Ltd.).
In addition, such a small particle size is commercially available in a sol form so as to be easy to handle, and can be suitably used according to the application.
[0148]
As such a photocatalyst sol for activating a cured coating film, trade name “STS-01” (manufactured by Ishihara Techno Co., Ltd.) and trade name “KS-247” (manufactured by Teika Co., Ltd.) can be mentioned. In order to improve color stability, physical properties, etc., the above photocatalyst fine particles, rutile or brookite type titanium oxide for pigments that are generally used for paints and have less photoactivity than anatase type, and photocatalyst A strong anatase type titanium oxide may be used in combination.
[0149]
In the present invention, the top coat coating (III) may contain a component (second component) that can further improve the photocatalytic function together with the photocatalyst (D) for activating the cured coating. Examples thereof include metals and / or metal compounds such as V, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Pt, and Au. Examples of the metal compound include oxides, hydroxides, oxyhydroxides, sulfates, halides, nitrates, and metal ions.
[0150]
In the present invention, the above-mentioned titanium oxide is used alone, or titanium oxide and other photocatalytic substance are used in combination, so that it was photoexcited by normal light irradiation (eg, wavelength of 400 nm or less) such as ultraviolet rays described later. Occasionally, photocatalytic action generates electron-hole pairs in titanium oxide, and oxygen molecules and water molecules react with these electron-hole pairs, resulting in high oxidation power superoxide ions (superoxide ions) and peroxidation. Active oxygen, such as hydrogen and hydroxyl radicals, is generated, and this active oxygen oxidizes and decomposes organic contaminants on the surface of the coating film (especially the top coat film (III)), dropping, scattering, and killing. Therefore, it is considered that the stain resistance of the surface of the topcoat coating film (III) is maintained well.
[0151]
In the composite of the present invention having a topcoat coating (III) containing such a cured coating film-activating photocatalyst (D), particularly a cured coating film, the photocatalyst for activating the cured coating film ( D) is activated and, for example, as described in JP-A-2000-42480, paragraphs [0015] to [0016], the surface of the topcoat coating (III) side is coated with the film. When the thickness is about 0.1 μm, for example, sunlight (2-3 mW / cm in illuminance)²If it is irradiated for 2 to 3 hours, the photocatalyst for activating the cured coating film is activated, and stain resistance and the like are exhibited.
[0152]
<Production and curing of photocatalyst-containing curable polysiloxane inorganic coating composition>
In order to produce such a photocatalyst-containing curable polysiloxane inorganic coating composition (photocatalyst-containing inorganic paint), except for blending the photocatalyst (D), the colored paint for the intermediate layer (II) and However, it is also possible to add and mix a photocatalyst (D) or the like to each inorganic component used.
[0153]
That is, in the present invention, the photocatalyst-containing paint for the top coat layer is
(a): a silica-dispersed oligomer solution of organosilane obtained by partially hydrolyzing and polycondensing the hydrolyzable organosilane [II],
(b): the polyorganosiloxane [III],
The mixed liquid may be prepared by adding and mixing a photocatalyst for activating the cured coating film (D), a curing catalyst (C) (hydrolysis / polycondensation catalyst (C)), etc.
Photocatalyst-containing inorganic paint ((a) +) by adding / mixing the photocatalyst (D), curing catalyst (C), etc. to the inorganic component (photocatalyst binder) of any one of the above (a) and (b) (D) + (C), (b) + (D + (C))).
[0154]
In other words, in the present invention, the above (a) and (b) may be mixed and used as the inorganic binder for photocatalyst, and each of the above (a) and (b) inorganic components may be used as a photocatalyst. Each inorganic binder may be used alone.
<Topcoat coating film (III) Forming method>
In order to form a topcoat film (III) on the surface of the intermediate coating film (II) by coating and curing such a photocatalyst-containing inorganic paint, the same method as in the case of the intermediate coating film (II) may be used. . That is, depending on the film thickness of the topcoat coating film (III), the composition of the photocatalyst-containing inorganic paint, the photocatalyst-containing inorganic paint is applied (applied) to the surface of the intermediate coating film (II), or It fills on the intermediate | middle coating film (II) coated in the type | mold, Usually, 30-250 degreeC, Preferably it is the temperature of 80-200 degreeC, 0.05-3 hours, Preferably it is 0.1-1. The photocatalyst-containing inorganic paint is heated for about 5 hours, or may be kept at room temperature for 1 to 120 hours, preferably 5 to 72 hours. If the paint is kept under heating or at room temperature in this way, Cured to form a gel film.
[0155]
The average film thickness of the thus obtained topcoat coating film (III) is usually 0.01 to 50 μm, preferably 0.1 to 20 μm.
[0156]
【The invention's effect】
The composite according to the present invention, for example, the composite coating film, is such that the undercoat film (I), the intermediate coating film (II), and the topcoat film (III) are in close contact, and the color pigment and the cured coating film The photocatalyst for activation (photocatalyst) can be contained in a separate layer, that is, the color pigment can be contained in the intermediate coating (II) as an intermediate layer, and the photocatalyst can be contained in the topcoat coating (III) of the top coating layer. It has become. Therefore, in the present invention, even if the color pigment to be blended is organic, it does not receive photocatalytic action, so that the organic pigment or the like does not fade, and any organic or inorganic colorant can be blended. Become. In addition, as a color pigment to be used, an arbitrary color can be selected freely from a light color system to a dark color system without considering the influence on the photocatalytic action, and the range of color pigment selection is widened. Also, as a photocatalyst, it is basically blended into the topcoat film (III) as an overcoat layer different from the color pigment, so the effect of the color pigment compounded in the intermediate film (II) Each of the functions of the color pigment and the photocatalyst can be sufficiently exerted, such as being able to sufficiently exhibit the anti-contamination effect without being subjected to light.
[0157]
Therefore, if such a composite coating film is provided so that its undercoat coating film (I) side is in close contact with the base material surface of a heavily soiled outdoor member such as a metal panel, guardrail, or building material, the film thickness and A coating film excellent in anticorrosion properties and excellent in stain resistance, durability and surface hardness can be formed on the substrate surface. Moreover, the base material coat | covered with the coating film which consists of a composite of such the outstanding characteristic is provided.
[0158]
In the present invention, when manufacturing such a base material with a composite coating film, a powder coating material for the base coating film (I) excellent in film thickness and anticorrosion properties on the surface of the base material such as metal or building material. (I) is coated, and the surface is coated with a curable polysiloxane inorganic coating composition (colored paint) containing a coloring pigment for the intermediate coating (II) that is excellent in durability, adhesion, and weather resistance. Then, by coating the surface with a photocatalyst-containing curable polysiloxane inorganic coating composition (photocatalyst-containing inorganic paint) excellent in stain resistance, durability and surface hardness, film thickness and corrosion resistance The composite coating film is excellent on the surface of the substrate and has excellent contamination resistance, durability and surface hardness.
[0159]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples at all.
Each component used in the following Examples and Comparative Examples, its production method, each test method, etc. are as follows.
[0160]
(Method for producing epoxy resin powder coating)
Each component of the type and amount shown in Table 1 is uniformly mixed for about 1 minute with a drive render [manufactured by Aichi Electric Co., Ltd., trade name: docking mixer], and then an extrusion kneader [manufactured by Prism Co., Ltd. Name: biaxial kneader] was melt-kneaded at 80 to 100 ° C., and after cooling, finely pulverized with a hammer type impact pulverizer. Next, it was treated with a 106-micron void mesh wire net, and the passing portion was collected to obtain a thermosetting epoxy powder coating for undercoating.
[0161]
(Coloring pigment-containing curable polysiloxane inorganic coating composition)
<Physical properties of inorganic polymer, production method>
(i) Synthesis of organosiloxane (a) or its partially hydrolyzed condensate (b)
[Partial hydrolysis condensate of organosiloxane (b)-(1)]
In a flask equipped with a stirrer, a heating jacket, a condenser and a thermometer, 30 parts of tetraethoxysilane, 30 parts of methyltrimethoxysilane, 5 parts of water and 35 parts of IPA (isopropyl alcohol) were added and stirred at 60 ° C. Then, the hydrolysis reaction was carried out for about 5 hours, followed by cooling to obtain a partially hydrolyzed condensate of organosilane “(b)-(1)”. This condensate had a solid content in terms of total condensate of 32%.
[0162]
[Partial hydrolysis condensate of organosiloxane (b)-(2)]
In a flask equipped with a stirrer, heating jacket, condenser and thermometer, IPA-dispersed colloidal silica sol “IPA-ST” (particle size 10-20 nm, solid content 30%, moisture 0.5%, Nissan Chemical Co., Ltd.) 100 parts), 68 parts of methyltrimethoxysilane and 0.8 parts of water were added, and after hydrolysis was performed at 65 ° C. for about 5 hours with stirring, the organosilane was partially hydrolyzed by cooling. The decomposition condensate “(b)-(2)” was obtained. This condensate had a solid content in terms of the total condensate of 36% when left at room temperature for 48 hours.
[0163]
(ii) Synthesis of curable organopolysiloxane (c)
A flask equipped with a stirrer, a heating jacket, a condenser, a dropping funnel and a thermometer was charged with a solution obtained by dissolving 230 parts (1 mol) of methyltriisopropoxysilane in 140 parts of toluene. 108 parts were added dropwise over 20 minutes to hydrolyze methyltriisopropoxysilane at 60 ° C. with stirring. Stirring was stopped 40 minutes after the completion of dropping, and the reaction solution was transferred to a separating funnel and allowed to stand, and then separated into two layers.
[0164]
The mixture of the lower layer water and isopropyl alcohol containing a small amount of hydrochloric acid was separated and removed. The remaining hydrochloric acid in the remaining toluene resin solution was removed by washing with water, and the toluene was removed under reduced pressure. By diluting the product with isopropyl alcohol, an isopropyl alcohol solution of silanol group-containing organopolysiloxane (curable organopolysiloxane) (c) having an average molecular weight (Mw) of about 2000 was obtained.
[0165]
The total condensed compound equivalent solid content of this solution is 40%.
Further, it has been confirmed that the curable polyorganosiloxane (c) in this solution satisfies the average composition formula (III).
<Coloring pigment>
Rutile titanium oxide (white) (average particle size: 200 nm)
<Production method of colored paint for intermediate coating>
The organosiloxane partial hydrolysis-condensation condensate (b), curable polyorganosiloxane (c) and catalyst synthesized by the above-mentioned production method are mixed in a predetermined ratio and stabilized, and then a predetermined amount of dispersant is added. After mixing the solvent and the pigment, the mixture was stirred using a disperser.
[0166]
After this solution is taken out using a mesh, a photocatalyst-containing curable polysiloxane system is obtained by uniformly dispersing the color pigment to the primary particle diameter using a horizontal zirconia vessel mill (manufactured by Asada Steel Corporation). An inorganic coating composition was prepared.
(Photocatalyst-containing curable polysiloxane inorganic coating composition)
<Inorganic polymer production method>
The inorganic polymer was prepared by a method similar to the method for producing an inorganic polymer when used in the above-mentioned color pigment-containing curable polysiloxane inorganic coating composition.
[0167]
<Types of photocatalyst>
(A) Photocatalyst A: Photocatalytic titanium oxide sol (solid content 30%)
Crystal system (anatase type)
(B) Photocatalyst B: photocatalytic titanium oxide powder having an average particle diameter of 7 nm
Crystal system (anatase type)
<Method for producing photocatalyst-containing curable polysiloxane inorganic coating composition>
(i) Production method of photocatalyst paint when each inorganic component is used
▲ 1 ▼Photocatalyst-containing paints “A-1” and “A-4”:
Partially hydrolyzed condensate of organosiloxane “(ro)-(1)” (in the case of paint A-1) or “(ro)-(2)” (in the case of paint A-4) obtained by the above production method After weighing and adding the catalyst, a mixed solvent of isopropanol (IPA) and methanol was added, diluted, and allowed to stand for 1 hour. This solution was poured into a polyethylene measuring container, photocatalytic titanium oxide powder was added, and the mixture was stirred using a disperser to make the photocatalyst fine particles affinity for the solvent. The photocatalyst titanium oxide powder (ST-01) is added to this mixed solution, and the target photocatalyst is obtained by pulverizing and stabilizing the photocatalyst fine particles to the primary particle size with a zirconia vessel using 0.7 mm zirconia beads. Containing curable polysiloxane inorganic coatings “A-1” and “A-4” were prepared.
[0168]
▲ 2 ▼Photocatalyst-containing paint “A-2”:
The organosiloxane partial hydrolysis-condensation product “(b)-(1)” obtained by the above production method was weighed, a catalyst was added, a mixed solvent of IPA and methanol was added, diluted, and then allowed to stand for 1 hour. I put it. While stirring this solution, a nitric acid aqueous solution-dispersed photocatalytic titanium oxide sol was gently dropped over 10 minutes using a dropping funnel to prepare a target photocatalyst-containing curable polysiloxane inorganic coating composition “A-2”. .
[0169]
▲ 3 ▼Photocatalyst-containing paint “A-3”:
The curable organopolysiloxane (c) obtained by the above production method was weighed, a catalyst was added, a mixed solvent of methanol and ethanol was added, diluted, and allowed to stand for 1 hour. This solution was poured into a polyethylene measuring container, photocatalytic titanium oxide powder was added, and the mixture was stirred using a disperser to make the photocatalyst fine particles affinity for the solvent. By pulverizing the photocatalyst fine particles to the primary particle size with a zirconia vessel mill using 0.7 mm zirconia beads and stabilizing the mixed solution, the target photocatalyst-containing curable polysiloxane inorganic coating “A- 3 "was prepared.
[0170]
▲ 4 ▼Photocatalyst-containing paint “A-5”:
The curable organopolysiloxane (c) obtained by the above production method was weighed, a catalyst was added, a mixed solvent of IPA and methanol was added, diluted, and allowed to stand for 1 hour. While stirring this solution, a nitric acid aqueous solution-dispersed photocatalytic titanium oxide sol was gently dropped over 10 minutes using a dropping funnel to prepare a target photocatalyst-containing curable polysiloxane inorganic coating composition “A-5”. .
[0171]
▲ 5 ▼Photocatalyst-containing paint “A-7”:
The organosiloxane partially hydrolyzed condensate (b) obtained by the above production method and the curable organopolysiloxane (c) are mixed in a predetermined ratio, and after adding a catalyst, a mixed solvent of ethanol and methanol is added, After dilution, the mixture was allowed to stand for 1 hour. This solution was poured into a polyethylene measuring container, a photocatalytic titanium oxide powder was added, and the mixture was stirred using a disperser to make the photocatalytic fine particles affinity with the solvent. By pulverizing the photocatalyst fine particles to the primary particle size with a zirconia vessel mill using 0.7 mm zirconia beads and stabilizing this mixed solution, the desired photocatalyst-containing curable polysiloxane inorganic coating “A-7” Was prepared.
[0172]
▲ 6 ▼Photocatalyst-containing paint “A-8”:
The organosiloxane partially hydrolyzed condensate “(b)-(2)” obtained by the above production method and the curable organopolysiloxane (c) were mixed at a predetermined ratio, and after adding a catalyst, IPA and methanol were mixed. After adding and diluting the mixed solvent, the mixture was allowed to stand for 1 hour. While stirring this solution, a nitric acid aqueous solution-dispersed photocatalytic titanium oxide sol was gently dropped over 10 minutes using a dropping funnel to prepare a target photocatalyst-containing curable polysiloxane inorganic coating composition “A-8”. .
[0173]
▲ 7 ▼Photocatalyst-containing paint “A-6”:
After weighing the organosiloxane partially hydrolyzed condensate “(b) -2” and acrylic silicone resin obtained by the above-mentioned production method and adding a catalyst, a mixed solvent of IPA and methanol is added and diluted. And left for 1 hour. This solution was poured into a polyethylene measuring container, photocatalytic titanium oxide powder was added, and the mixture was stirred using a disperser to make photocatalyst particles compatible with the solvent. The target photocatalyst is prepared by adding photocatalytic titanium oxide powder (ST-01) to this mixed solution and pulverizing and stabilizing the photocatalyst fine particles to the primary particle size with a zirconia vessel using 0.7 mm zirconia beads. Containing curable polysiloxane inorganic coating material “A-6” was prepared.
[0174]
▲ 8 ▼Photocatalyst-containing paint “A-9”:
After mixing the organosiloxane partially hydrolyzed condensate “(b)-(1)” obtained in the above production method, the curable organopolysiloxane (c) and the acrylic silicone resin in a predetermined ratio, and adding the catalyst After adding and diluting a mixed solvent of IPA and methanol, the mixture was allowed to stand for 1 hour. A nitric acid aqueous solution-dispersed photocatalytic titanium oxide sol was gently dropped over 10 minutes using a dropping funnel to prepare a target photocatalyst-containing curable polysiloxane inorganic coating “A-9”.
[0175]
<Value test item>
Moreover, the various physical property measuring methods used in Examples and Comparative Examples are as follows.
(a) Contamination resistance test: Contamination resistance test after 1 month of outdoor exposure
The specimen panel was installed in a severely contaminated area along National Route 8, and the state of the stain after being left for one month was confirmed by visual observation and color difference measurement.
[0176]
3: No visual contamination and good appearance. And ΔE change rate is less than 1.
2: There are sparsely contaminated parts, and the whole is lightly darkened. And ΔE change rate: 1 or more and less than 2.
1: Black wrinkles on the whole and it was very dirty. And ΔE change rate: 2 or more.
(b) Adhesive ( JIS K-5400 , 8.5 According to the cross-cut method)
Evaluation is made with a clearance of 2 mm and a square of 25.
[0177]
3: Each cut is thin and smooth on both sides, and there is no peeling at a glance at the intersection of the cut and the square.
2: There are peeling at both sides of the cut and at the intersection, and the area of the defect is less than 15% of the total square area.
1: There is peeling on both sides of the cut and the intersection, and the area of the defect is 15% or more of the total square area.
[0178]
(c) Weatherability( JIS K-5400 9.8.1 Sunshine carbon arc lamp type)
The gloss retention after 1500 hours and the color difference are evaluated in accordance with “JIS D-0205 7.6 Change in light change rate and 7.4” for fading color.
3: Almost no change is observed. Gloss retention 85% or more. Color difference less than 1.5.
2: Gloss retention 60% or more and less than 85. Color difference of 1.5 or more.
[0179]
1: Gloss retention is less than 60%. Color difference of 1.5 or more.
(d) Pencil hardness( JIS K-5400 8.4.1 (By testing machine method)
Evaluation is based on scratches on the paint film.
3: 5H or more.
2: 2H or more and less than 5H.
[0180]
1: Less than 2H.
(e) Salt water resistance ( JIS K-5400 9.1 by)
The appearance of the coating film after 500 hours test and the blister width of the cut part are investigated.
3: No abnormality is observed in the appearance of the coating film. The blister width is less than 3 mm.
2: No abnormality is observed in the appearance of the coating film. The blister width is 3 mm or more.
[0181]
1: The coating film has swelling and rusting, and the swelling width on one side is 3 mm or more.
(f) Moisture resistance ( JIS K-5400 9.2 (By rotary type)
The appearance of the coating after the 500 hour test is investigated.
3: No abnormality is observed in the appearance of the coating film.
2: Cloudiness is recognized in the coating film appearance.
[0182]
1: Any of wrinkles, blisters, cracks, rust, and peeling is recognized on the appearance of the coating film.
[0183]
[Example 1]
As a substrate to be coated, the powder coating material shown in Table 1 is formed on the surface of a substrate (material: soft steel plate, dimensions: 2 × 150 × 70 mm) that has been subjected to chemical conversion treatment (type: zinc phosphate treatment) in advance. (No .: P-1) is applied four times with a coating machine (type: electrostatic powder coating machine), and then a dryer (model: thermostat, model number: PHH-101, manufacturer: Tabai Espec) ) At a temperature of 170 ° C. for 20 minutes to form an undercoat film having an average film thickness of 60 μm.
[0184]
Next, the surface coating film surface was spray-coated with an intermediate coating color paint (number: C-1) shown in Table 1 so as to have an average coating film thickness of 40 μm, and then conditions (heating temperature: 170 ° C., Time: 20 minutes), a drying or curing reaction was performed to form an intermediate coating film having a dry film thickness of 20 μm.
Next, the surface of the intermediate coating film was spray-coated with the photocatalyst-containing paint (number: A-1) shown in Table 2 so as to have an average coating thickness of 10 μm, and then conditions (heating temperature; 170 ° C., time: 20) The test plate having a dry film thickness of 0.5 μm was obtained.
[0185]
Each test was performed by the method shown above about the obtained test board, and performance was evaluated.
As a result, the properties were excellent in a balanced manner as described below.
(A) Contamination resistance: 3 (contamination is not visually observed, appearance is good, ΔE change rate, that is, “an index indicating color change, exposure to the outdoors compared to the coating film immediately after coating”
The “index indicating the color change of the coating film after one month” is within one. )
(B) Weather resistance: 3 (conforms to JIS K-5400, 9.8.1. Almost no color change. Gloss retention of 85% or more. Color difference of less than 1.5.)
(C) Pencil hardness: 3 (based on JIS K-5400, 8.1. Abrasion resistance of coating film: 5H or more.)
(D) Circular salt water spray resistance (salt water resistance): 3 (conforms to JIS, K-5400, 9.1. No abnormality in coating film appearance.
(E) Moisture resistance: 3 (JIS K-5400, 9.2 rotation type compliant. No abnormalities in coating film appearance after 500 hours test).
[0186]
The results are also shown in Table 3.
[0187]
Examples 2-36 and Comparative Examples 1-2
In Example 1, a coating test plate was prepared in the same manner as in Example 1 except that the undercoat powder paint, the intermediate coating color paint, and the topcoat photocatalyst-containing paint were changed as shown in Tables 1 to 3, respectively. The same test as described above was performed to evaluate the performance.
The results are shown in Table 3.
[0188]
The amount of each component in the following table is indicated by “parts by weight”.
[0189]
[Table 1]

[0190]
[Table 2]

[0191]
[Table 3]

Claims (16)

(I) an undercoat film formed from a powder paint;
(II) an intermediate coating film provided on the undercoat powder coating film (I) and formed from a color pigment-containing curable polysiloxane inorganic coating composition;
(III) a top coat film provided on the intermediate coating film (II) and formed from a photocatalyst-containing curable polysiloxane inorganic coating composition;
The colored pigment-containing curable polysiloxane inorganic coating composition is
(A) a coloring pigment;
(B) (B1) an organosiloxane and / or a partially hydrolyzed condensate thereof;
(B2) containing a curable organopolysiloxane and, if necessary, (C) a curing catalyst for the component (B),
The photocatalyst-containing curable polysiloxane inorganic coating composition is
(D) a photocatalyst for activating a cured coating film having an average particle diameter of 1 to 250 nm mainly composed of titanium oxide;
A composite comprising (B) an organosiloxane, a partially hydrolyzed condensate thereof, or a curable organopolysiloxane, and, if necessary, (C) a curing catalyst for the component (B).   The powder coating material is at least one selected from the group consisting of a fluororesin powder coating material, a polyester resin powder coating material, an epoxy resin powder coating material, an acrylic resin powder coating material, and a urethane resin powder coating material. The composite according to claim 1, which is a coating material.   The composite according to claim 1, wherein the titanium oxide is anatase-type titanium oxide.   The composite according to any one of claims 1 to 3, wherein the titanium oxide is anatase-type titanium oxide having an average particle diameter of 7 to 250 nm.   The colored pigment-containing curable polysiloxane inorganic coating composition and / or the photocatalyst-containing curable polysiloxane inorganic coating composition further contains (E) a polymerizable silicone (meth) acrylate copolymer. The complex in any one of -4.   The composite according to claim 5, wherein the polymerizable silicone (meth) acrylate copolymer (E) is acrylic silicone. The photocatalyst-containing curable polysiloxane inorganic coating composition contains (E) a polymerizable silicone (meth) acrylate copolymer as necessary, and components (B), (C), (D), and (E )) And 100 parts by weight,
20 to 80 parts by weight of component (B),
0 to 10 parts by weight of component (C), and 20 to 80 parts by weight of component (D),
The composite according to any one of claims 1 to 4 , wherein the component (E) is contained in an amount of 0 to 50 parts by weight. The photocatalyst-containing curable polysiloxane inorganic coating composition contains (E) a polymerizable silicone (meth) acrylate copolymer as necessary, and components (B), (C), (D), and (E )) And 100 parts by weight,
30 to 70 parts by weight of component (B),
0 to 5 parts by weight of component (C), and 30 to 70 parts by weight of component (D),
The composite according to any one of claims 1 to 4 , wherein the component (E) is contained in an amount of 0 to 40 parts by weight.   The composite according to any one of claims 1 to 8, wherein the curing catalyst (C) for the component (B) is a carboxylic acid metal salt, an amine, an acid, an alkali metal salt, a titanium compound, or a halogen compound.   The composite according to any one of claims 1 to 9, wherein the photocatalyst-containing curable polysiloxane inorganic coating composition further contains (A) a color pigment.   The composite according to any one of claims 1 to 10, wherein the photocatalyst-containing curable polysiloxane inorganic coating composition further contains (F) an organosilica sol as an inorganic binder.   The composite according to claim 1, wherein the composite is a coating film.   It consists of a base material and the coating film which consists of a composite_body | complex in any one of Claims 1-11 provided in this base-material surface, The base coat film (I) side of this composite_body | complex is directly with a base material or The base material with a coating film characterized by adhering through another layer.   The substrate with a coating film according to claim 13, wherein the substrate is a metal panel.   The base material with a coating film according to claim 13, wherein the base material is a building material. On the substrate surface,
(I) Apply the powder coating (I), cure,
The colored pigment-containing curable polysiloxane inorganic coating composition according to any one of claims 1 to 6 is applied to the surface of the obtained undercoat film (I), cured, and then
The photocatalyst-containing curable polysiloxane inorganic coating composition according to any one of claims 1 to 11 is applied to the surface of the obtained intermediate coating film (II) and cured to form a topcoat coating film (III). The manufacturing method of the base material with a coating film characterized by forming.