JP3764112B2 - Paint finishing method and painted article - Google Patents

Description

（式中のＲ^５およびＲ^６はそれぞれ水素原子または炭素数1〜４のアルキル基であり、ｙは１〜１０の整数である。）で表される有機基であることを特徴とする塗装仕上げ方法を提供するものである。
【００１０】
また、本発明は、上記耐汚染性塗装仕上げ方法において、透明プライマーが（ａ） 水酸基とエポキシ基の両方を有するアクリル樹脂、（ｂ）アミノプラスト樹脂、及び（ｃ）ウレタン樹脂硬化剤を必須成分とし、場合により用いられる（ｄ）内部架橋型樹脂微粒子及び／又は（ｅ）ケトン系溶剤を含有して成ることを特徴とする塗装仕上げ方法を提供するものである。
また、本発明は、上記耐汚染性塗装仕上げ方法において、透明プライマーが不揮発分比で（ａ）成分を４０〜８０質量％、（ｂ）成分を０〜６０質量％、（ｃ）成分を０〜６０質量％の割合で含有することを特徴とする塗装仕上げ方法を提供するものである。
【００１１】
また、本発明は、上記耐汚染性塗装仕上げ方法により塗装されたことを特徴とする塗装物品を提供するものである。
本発明のさらに他の目的、態様及び利点は、以下の記載から十分にされるであろう。
【００１２】
【発明の実施の形態】
本発明の塗装仕上げ方法においてオーバークリヤーコート塗料として用いられる耐汚染性塗料組成物（以下、単に塗料組成物と略すこともある。）の（Ａ）成分の変性樹脂は、塗膜を親水化させるのに必要である（Ｃ）成分のオルガノシリケート及び／又はその縮合物を塗膜中に均一に分散させ、親水性の発現と耐水性の向上の両立を果たすために用いられる。かかる変性樹脂としては、一般式（１）
（Ｒ^１）_ｍ−Ｓｉ−（ＯＲ^２）_４−ｍ （１）
（式中のＲ^１およびＲ^２はそれぞれ水素原子または炭素数１〜１０のアルキル基またはアリール基であり、ｍは０又は１である。）で表されるオルガノシリケート及び／又はその縮合物の存在下で、水酸基を有するラジカル重合性単量体と、エポキシ基を有するラジカル重合性単量体と、場合により用いられるその他のラジカル重合性単量体の混合物を有機溶媒中で通常のラジカル共重合することにより得られる。このラジカル重合性単量体混合物はアクリル樹脂合成用の重合性単量体混合物であるので、その中にアクリル系重合性単量体を、少なくとも５０質量％以上、好ましくは７５質量％以上、特に好ましくは９０質量％以上含有する。
【００１３】
一般式（１）で表されるオルガノシリケートの好ましい具体例としては、例えば、テトラヒドロキシシラン、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、テトラフェノキシシラン、ジメトキシジエトキシシラン、メチルトリメトキシシラン、メチルトリエトキシシラン、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、ブチルトリメトキシシラン、ヘキシルトリメトキシシラン、デシルトリメトキシシラン、エトキシトリメトキシシラン、プロポキシトリメトキシシラン、ブトキシトリメトキシシランなどが挙げられる。
また、オルガノシリケートの縮合物としては、前記一般式（１）で表されるオルガノシリケートの１種又は２種以上の分岐状もしくは直鎖状の縮合物であって、重量平均分子量が２００〜２０００の範囲にあるものが好ましく、３００〜１５００の範囲内にあるものが特に好ましい。オルガノシリケートの縮合物の市販品としては、ＭＫＣシリケートＭＳ５１、ＭＳ５６、ＭＳ５７、ＭＳ５６Ｓ、ＭＳ５８Ｂ１５、ＥＳ４０、ＥＭＳ３１、ＢＴＳ（いずれも商品名、三菱化学（株）製）、メチルシリケート５１、エチルシリケート４０、エチルシリケート４０Ｔ、エチルシリケート４８、ＥＭＳ−４８５（いずれも商品名、コルコート（株）製）、エチルシリケート４０、４５（いずれも商品名、多摩化学工業（株）製）などが挙げられ、該オルガノシリケートの縮合物の市販品を微量の水存在下でさらに縮合を進めたものも用いることができる。
一般式（１）で表されるオルガノシリケート及び／又はその縮合物は（Ａ）成分の変性樹脂中１〜７０質量％の範囲内で用いられることが望ましく、１．５〜５０質量％がより望ましく、２〜４０質量％が特に望ましい。該オルガノシリケート及び／又はその縮合物が１質量％未満の場合、最終的に得られる硬化塗膜の耐水性が低下するため好ましくなく、また、７０質量％を越える場合は、変性反応の際にゲル化しやすくなるため好ましくない。
【００１４】
水酸基を有するラジカル重合性単量体の具体例としては、例えば、アクリル酸２−ヒドロキシエチル、アクリル酸２−ヒドロキシプロピル、アクリル酸３−ヒドロキシプロピル、アクリル酸４−ヒドロキシブチル、メタクリル酸２−ヒドロキシエチル、メタクリル酸２−ヒドロキシプロピル、メタクリル酸３−ヒドロキシプロピル、メタクリル酸４−ヒドロキシブチル、アリルアルコール、アクリル酸とバーサチック酸グリシジルエステルの付加物、メタクリル酸とバーサチック酸グリシジルエステルの付加物；アクリル酸２−ヒドロキシエチル、アクリル酸２−ヒドロキシプロピル、アクリル酸３−ヒドロキシプロピル、アクリル酸４−ヒドロキシブチル、メタクリル酸２−ヒドロキシエチル、メタクリル酸２−ヒドロキシプロピル、メタクリル酸３−ヒドロキシプロピル、又はメタクリル酸４−ヒドロキシブチルのε−カプロラクトン付加物；アクリル酸２−ヒドロキシエチル、アクリル酸２−ヒドロキシプロピル、アクリル酸３−ヒドロキシプロピル、アクリル酸４−ヒドロキシブチル、メタクリル酸２−ヒドロキシエチル、メタクリル酸２−ヒドロキシプロピル、メタクリル酸３−ヒドロキシプロピル、又はメタクリル酸４−ヒドロキシブチルのエチレンオキサイド及び／又はプロピレンオキサイド付加物などが挙げられ、１種又は２種以上の混合物として用いられる。
【００１５】
また、エポキシ基を有するラジカル重合性単量体の具体例としては、例えば、アクリル酸グリシジル、メタクリル酸グリシジル、アクリル酸３,４−エポキシシクロヘキシルメチル、メタクリル酸３,４−エポキシシクロヘキシルメチルなどが挙げられ、１種又は２種以上の混合物として用いられる。
ここで、水酸基を有するラジカル重合性単量体は、（Ａ）成分の変性樹脂のアクリル樹脂構造部分を構成する全単量体中１〜３０質量％の範囲内で用いられることが望ましく、１．５〜１５質量％がより望ましく、２〜７質量％が特に望ましい。該ラジカル重合性単量体が１質量％未満の場合、最終的に得られる硬化塗膜の耐水性が低下するため好ましくなく、また、３０質量％を越える場合は、変性反応の際にゲル化しやすくなるため好ましくない。
また、エポキシ基を有するラジカル重合性単量体は、（Ａ）成分の変性樹脂のアクリル樹脂構造部分を構成する全単量体中１〜７０質量％の範囲内で用いられることが望ましく、５〜６０質量％がより望ましく、１０〜５０質量％が特に望ましい。該ラジカル重合性単量体が１質量％未満の場合、最終的に得られる硬化塗膜の耐溶剤性が不十分となるため好ましくなく、また、７０質量％を越える場合は、硬化塗膜の耐クラック性が低下するため好ましくない。
【００１６】
その他のラジカル重合性単量体の具体例としては、例えば、アクリル酸メチル、アクリル酸エチル、アクリル酸ｎ−プロピル、アクリル酸イソプロピル、アクリル酸ｎ−ブチル、アクリル酸イソブチル、アクリル酸ｓｅｃ−ブチル、アクリル酸ヘキシル、アクリル酸シクロヘキシル、アクリル酸２−エチルヘキシル、アクリル酸オクチル、アクリル酸ラウリル、アクリル酸ステアリルなどのアクリル酸アルキルエステル、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ｎ−プロピル、メタクリル酸イソプロピル、メタクリル酸ｎ−ブチル、メタクリル酸イソブチル、メタクリル酸ｓｅｃ−ブチル、メタクリル酸ヘキシル、メタクリル酸シクロヘキシル、メタクリル酸２−エチルヘキシル、メタクリル酸オクチル、メタクリル酸ラウリル、メタクリル酸ステアリルなどのメタクリル酸アルキルエステル、スチレン、アクリロニトリル、メタクリロニトリル、アクリルアミド、メタクリルアミドなどが挙げられ、１種又は２種以上の混合物として用いられる。
また、（Ａ）成分の変性樹脂のアクリル樹脂構造部分を構成する単量体としては、一般式（３）で示される有機基を含有するラジカル重合性単量体を用いることもできる。
【００１７】
【化３】

【００１８】
（式中のＲ^５及びＲ^６はそれぞれ水素原子又は炭素数1〜４のアルキル基であり、ｙは１〜１０の整数である。）
かかるラジカル重合性単量体の具体例としては、例えば、アクリル酸２−メトキシプロピル、アクリル酸２−メトキシエチル、アクリル酸２−エトキシプロピル、アクリル酸２−エトキシエチル、メタクリル酸２−メトキシプロピル、メタクリル酸２−メトキシエチル、メタクリル酸２−エトキシプロピル、メタクリル酸２−エトキシエチル、ブレンマーＰＭＥ−１００、−２００、−４００、ブレンマーＰＥ−９０、−２００、−３５０、ブレンマーＰＰ−１０００、−５００（いずれも商品名、日本油脂（株）製）などが挙げられ、１種又は２種以上の混合物として得られる。一般式（３）で示される有機基を含有するラジカル重合性単量体は、（Ｃ）成分のオルガノシリケート及び／又はその縮合物が少量でも有効に塗膜表面に配向させ目的の親水性を発現させるのに有用であり、（Ａ）成分の変性樹脂のアクリル樹脂構造部分を構成する全単量体に対して０〜４０質量％の範囲内で用いられることが望ましく、１〜３５質量％がより望ましく、２〜３０質量％が特に望ましい。ここで、該ラジカル重合性単量体が４０質量％を越える場合は、塗膜の極性が高すぎ平滑性、耐水性が低下するため好ましくない。
【００１９】
（Ａ）成分の変性樹脂は、アクリル樹脂構造部分を合成後に一般式（１）で表されるオルガノシリケート及び／又はその縮合物を反応させる方法も考えられるが、この場合オルガノシリケート及び／又はその縮合物が遊離して残り、塗膜中で島状となり、外観性を損ねることがあるため、好ましくない。
また、本発明に用いる耐汚染性塗料組成物において、（Ａ）成分の変性樹脂は（Ａ）〜（Ｃ）成分の全不揮発分総量に対して３〜８０質量％の範囲内で用いられることが望ましく、１０〜７５質量％がより望ましく、２０〜７０質量％が特に望ましい。ここで（Ａ）成分が３質量％未満の場合、最終的に得られる硬化塗膜の耐汚染性が不十分となるため好ましくなく、また、８０質量％を越える場合は、硬化塗膜の耐水性が低下するため好ましくない。
【００２０】
本発明の塗装仕上げ方法においてオーバークリヤーコート塗料として用いられる耐汚染性塗料組成物の（Ｂ）成分は、（Ａ）成分の変性樹脂と熱硬化反応する化合物であり、カルボキシル基、カルボン酸無水物基及びアルキルビニルエーテル化合物でブロック化されたカルボキシル基から選ばれる少なくとも１種の官能基を有する化合物（以下、単に硬化剤と略す場合もある）である。かかる硬化剤の具体例において、カルボキシル基を有する化合物としては、例えば、コハク酸、マロン酸、グルタル酸、アジピン酸、アゼライン酸、セバシン酸、デカメチレンジカルボン酸、ダイマー酸、フタル酸、マレイン酸、トリメリット酸、ピロメリット酸、テトラヒドロフタル酸、ヘキサヒドロフタル酸、メチルヘキサヒドロフタル酸などが挙げられる。また、その他のカルボキシル基を有する化合物としては、▲１▼一分子当たり水酸基を１個以上、好ましくは２〜５０個有するポリオールとカルボン酸無水物とをハーフエステルさせる、▲２▼一分子当たりイソシアネート基を１個以上、好ましくは２〜５０個有するポリイソシアネート化合物とヒドロキシカルボン酸又はアミノ酸とを付加させる、▲３▼カルボキシル基含有ラジカル重合性単量体を単独重合又は他のラジカル重合性単量体と共重合させる、▲４▼カルボキシル基末端のポリエステル樹脂を合成するなどの方法によって得られる化合物などが挙げられる。また、カルボン酸無水物基を有する化合物としては、例えば、無水コハク酸、無水フタル酸、無水ヘキサヒドロフタル酸、メチル化無水ヘキサヒドロフタル酸、無水テトラヒドロフタル酸などの一分子中にカルボン酸無水物基を1個有する化合物の他に、酸無水物基を有するラジカル重合性単量体、例えば、無水マレイン酸、無水イタコン酸などと他のラジカル重合性単量体との共重合体が挙げられる。
【００２１】
さらに、アルキルビニルエーテル化合物でブロックされたカルボキシル基を有する化合物としては、上記のカルボキシル基を有する化合物のカルボキシル基をアルキルビニルエーテル化合物でブロックすることによって得られる化合物などが挙げられる。かかるアルキルビニルエーテル化合物の具体例としては、例えば、エチルビニルエーテル、ｎ−プロピルビニルエーテル、イソプロピルビニルエーテル、ｎ−ブチルビニルエーテル、イソブチルビニルエーテル、ｔ−ブチルビニルエーテル、ペンチルビニルエーテル、ヘキシルビニルエーテル、イソヘキシルビニルエーテル、シクロヘキシルビニルエーテル、２,３−ジヒドロフラン、３,４−ジヒドロフラン、３,４−ジヒドロ−２Ｈ−ピラン、３,４−ジヒドロ−２−メトキシ−２Ｈ−ピラン、３,４−ジヒドロ−４,４−ジメチル−２Ｈ−ピラン−２−オン、３,４−ジヒドロ−２−エトキシ−２Ｈ−ピランなどが挙げられる。
本発明に用いる耐汚染性塗料組成物において、（Ｂ）成分の硬化剤の含有量は、（Ａ）〜（Ｃ）成分の全不揮発分総量に対して３〜８０質量％が好ましく、５〜７０質量％がより好ましく、１０〜６０質量％が特に好ましい。（Ｂ）成分が３質量％未満の場合、最終的に得られる硬化塗膜の耐溶剤性が不十分となるため好ましくなく、また、８０質量％を越える場合は、硬化塗膜の耐クラック性が低下するため好ましくない。
【００２２】
本発明の塗装仕上げ方法においてオーバークリヤーコート塗料として用いられる耐汚染性塗料組成物の（Ｃ）成分は、塗膜表面に浮上し濃縮層を形成することで、塗膜硬化後に短時間で高度な耐汚染性を発現するために必要であり、一般式（２）で表されるオルガノシリケート及び／又はその縮合物が用いられる。一般式（２）で表されるオルガノシリケート及び／又はその縮合物の好ましい具体例としては、前記一般式（１）で表されるオルガノシリケート及び／又はその縮合物と同じものが挙げられる。
本発明に用いる耐汚染性塗料組成物において、（Ｃ）成分のオルガノシリケート及び／又はその縮合物の含有量は、（Ａ）〜（Ｃ）成分の全不揮発分総量に対して０．１〜３０質量％が好ましく、０．２〜２５質量％がより好ましく、０．５〜２０質量％が特に好ましい。（Ｃ）成分が０．１質量％未満の場合、硬化塗膜を形成した飽和水接触角が目的の耐汚染性能を満たすまで低下しないため好ましくなく、また、３０質量％を越える場合は、硬化塗膜の耐水性が低下するため好ましくない。
【００２３】
本発明の塗装仕上げ方法においてオーバークリヤーコート塗料として用いられる耐汚染性塗料組成物は、（Ｄ）脂肪族スルホン酸化合物又は脂肪族スルホン酸化合物のアミン塩、及び／又は（Ｅ）アミノプラスト樹脂を含有する。該（Ｄ）成分の脂肪族スルホン酸化合物又は脂肪族スルホン酸化合物のアミン塩は、主に（Ｃ）成分のオルガノシリケート及び／又はその縮合物の加水分解反応を促進するために用いられ、該成分の含有により塗膜形成直後から高度な親水性を得ることができる。かかる脂肪族スルホン酸化合物は、より具体的には炭素数４〜３０の範囲内にあるアルキル基を有するものが好ましく、該アルキル基を１又は２以上有するものがより好ましく、１又は２有するものが特に好ましい。１又は２以上のアルキル基の総炭素数は、８〜３０が好ましく、１０〜２４が特に好ましい。なお、アルキル基は、飽和であることが好ましいが、不飽和基を有するものであってもよい。脂肪族スルホン酸化合物の具体例としては、アニオン系脂肪族界面活性剤をイオン交換したものが挙げられる。ここで、イオン交換する方法としては、例えば、イオン交換樹脂を用いる、あるいは塩酸、硫酸、硝酸などの無機酸を加えて対カチオンを水素原子におきかえる方法などが挙げられる。該アニオン系脂肪族界面活性剤としては、例えば、
【００２４】
【化４】

【００２５】
（ただし、Ｒ^７は炭素数８〜３０のアルキル基、Ｒ^８は炭素数４〜１２のアルキル基、Ｒ^９は炭素数１３〜３０のアルキル基を示す。）などが挙げられる。
上記の方法で得られた脂肪族スルホン酸化合物はそのまま用いても良いし、アミン塩の形態で用いても良い。アミン塩としては、上記の方法で得られた脂肪族スルホン酸化合物をアミンで中和した塩が挙げられる。脂肪族スルホン酸化合物のアミン塩の具体例としては、例えば、メチルアミン、エチルアミン、プロピルアミン、イソプロピルアミン、ブチルアミン、ヘキシルアミン、オクチルアミン、ジメチルアミン、ジエチルアミン、ジプロピルアミン、ジブチルアミン、ジヘキシルアミン、ジオクチルアミン、トリメチルアミン、トリエチルアミン、トリプロピルアミン、トリブチルアミン、モノエタノールアミン、ジエタノールアミン、トリエタノールアミン、イソプロパノールアミン、ジイソプロパノールアミン、トリイソプロパノールアミン、ジメチルエタノールアミン、メチルジエタノールアミン、ピリジン、モルホリン、Ｎ−メチルモルホリン、アニリン、ジメチルアニリン、ジメチルベンジルアミン、テトラメチルブタンジアミン、ジメチルラウリルアミンなどが挙げられる。
ここで、（Ｄ）成分の脂肪族スルホン酸化合物又は脂肪族スルホン酸化合物のアミン塩の含有量は、（Ａ）〜（Ｃ）成分の全不揮発分総量に対して、０〜１０質量％が好ましく、０．１〜５質量％がより好ましく、０．２〜３質量％が特に好ましい。（Ｄ）成分の脂肪族スルホン酸化合物又は脂肪族スルホン酸化合物のアミン塩の含有量が１０質量％を越える場合は、硬化塗膜の耐水性が低下するため好ましくない。
【００２６】
さらに、本発明の塗装仕上げ方法においてオーバークリヤーコート塗料として用いられる耐汚染性塗料組成物は、（Ｅ）成分としてアミノプラスト樹脂を含有することもできる。該（Ｅ）成分のアミノプラスト樹脂は、下層の透明プライマーと反応することができ、該成分の含有により高度な密着性を得ることができる。かかるアミノプラスト樹脂としては、例えば、メラミン樹脂、尿素樹脂、グアナミン樹脂、グリコルリル樹脂などを用いることができ、中でもメラミン樹脂が耐候性の観点から特に好ましい。
ここで、（Ｅ）成分のアミノプラスト樹脂の含有量は、（Ａ）〜（Ｃ）成分の全不揮発分総量に対して、０〜３０質量％が好ましく、１〜２５質量％がより好ましく、２〜２０質量％が特に好ましい。（Ｅ）成分のアミノプラスト樹脂の含有量が３０質量％を越える場合は、硬化塗膜の耐酸性が低下するため好ましくない。
【００２７】
本発明に用いる耐汚染性塗料組成物は、そのままで、あるいは必要に応じて、有機溶剤及び／又は各種添加剤、例えば、紫外線吸収剤、光安定剤、酸化防止剤、界面活性剤、表面調整剤、抗発泡剤、硬化反応触媒、帯電防止剤、香料、脱水剤、さらにはポリエチレンワックス、ポリアマイドワックス、内部架橋型樹脂微粒子等のレオロジー調整剤などを添加して使用することができる。
本発明において用いられる透明プライマーは、下層の着色塗膜の色彩及びオーバークリヤーコート塗膜の外観性に悪影響を及ぼすことなく、オーバークリヤーコート塗膜の密着性を向上する目的で使用される。該透明プライマーは、前記の目的を達成できるものであれば、特に限定されるものではなく、各種の透明プライマーを用いることができる。
透明プライマーの好ましいものは、（ａ）水酸基とエポキシ基の両方を有するアクリル樹脂、（ｂ）アミノプラスト樹脂、及び（ｃ）ウレタン樹脂硬化剤を必須成分として含有するものである。
【００２８】
好ましい透明プライマーの（ａ）成分の水酸基とエポキシ基の両方を有するアクリル樹脂は、水酸基を有するラジカル重合性単量体と、エポキシ基を有するラジカル重合性単量体と、その他のラジカル重合性単量体の混合物を有機溶媒中で通常のラジカル共重合することにより得られる。このラジカル重合性単量体混合物はアクリル樹脂合成用の重合性単量体混合物であるので、その中にアクリル系重合性単量体を、少なくとも５０質量％以上、好ましくは７５質量％以上、特に好ましくは９０質量％以上含有する。また、水酸基を有するラジカル重合性単量体、エポキシ基を有するラジカル重合性単量体及びその他のラジカル重合性単量体の具体例としては、それぞれ前記と同じものが挙げられる。
【００２９】
ここで、水酸基を有するラジカル重合性単量体は、（ａ）成分のアクリル樹脂を構成する全単量体中１〜６０質量％の範囲内で用いられることが望ましく、５〜５５質量％がより望ましく、１０〜５０質量％が特に望ましい。該ラジカル重合性単量体が１質量％未満の場合、オーバークリヤーコート塗膜の密着性を向上することができないため好ましくなく、また、６０質量％を越える場合は、最終的に得られる硬化塗膜の外観性が低下するため好ましくない。
また、エポキシ基を有するラジカル重合性単量体は、（ａ）成分のアクリル樹脂を構成する全単量体中１〜４０質量％の範囲内で用いられることが望ましく、１．５〜３５質量％がより望ましく、２〜３０質量％が特に望ましい。該ラジカル重合性単量体が１質量％未満の場合、オーバークリヤーコート塗膜の密着性を向上することができないため好ましくなく、また、４０質量％を越える場合は、最終的に得られる硬化塗膜の外観性が低下するため好ましくない。
【００３０】
好ましい透明プライマーにおいて、（ａ）成分の水酸基とエポキシ基の両方を有するアクリル樹脂は、（ａ）〜（ｃ）成分の全不揮発分総量に対して４０〜８０質量％の範囲内で用いられることが望ましく、４５〜７５質量％がより望ましく、５０〜７０質量％が特に望ましい。ここで（ａ）成分が４０質量％未満あるいは８０質量％を越える場合は、いずれもオーバークリヤーコート塗膜の密着性を向上することができないため好ましくない。
好ましい透明プライマーの（ｂ）成分のアミノプラスト樹脂及び（ｃ）成分のウレタン樹脂硬化剤は、（ａ）成分のアクリル樹脂と熱硬化反応する化合物である。
該（ｂ）成分のアミノプラスト樹脂としては、例えば、メラミン樹脂、尿素樹脂、グアナミン樹脂、グリコルリル樹脂などを用いることができ、中でもメラミン樹脂が耐候性の観点から特に好ましい。ここで、（ｂ）成分のアミノプラスト樹脂の含有量は、（ａ）〜（ｃ）成分の全不揮発分総量に対して、０〜６０質量％が好ましく、１〜５５質量％がより好ましく、２〜５０質量％が特に好ましい。（ｂ）成分のアミノプラスト樹脂の含有量が６０質量％を越える場合は、オーバークリヤーコート塗膜の密着性を向上することができないため好ましくない。
【００３１】
また、該（ｃ）成分のウレタン樹脂硬化剤は、ウレタン樹脂を硬化できる硬化剤であれば特に制限なく、イソシアネート基及び／又はブロックイソシアネート基を１分子中に２個以上有するポリイソシアネート化合物が好ましい。イソシアネート基を１分子中に２個以上有するポリイソシアネート化合物の具体例としては、例えば、ヘキサンメチレンジイソシアネート、イソホロンジイソシアネート、トリレンジイソシアネート、ジフェニルメタンジイソシアネート、キシリレンジイソシアネート、ジシクロヘキシルメタン−４，４−ジイソシアネートのようなイソシアネートモノマーと呼ばれる化合物、これらのビウレット体、イソシアヌレート体、トリメチロールプロパンなどとのアダクト体のようなポリイソシアネート誘導体などが挙げられる。これらのポリイソシアネート化合物は１種用いてもよいし、２種以上を組み合わせて用いてもよい。
【００３２】
ポリブロックイソシアネート化合物の具体例としては、例えば、前記のポリイソシアネート化合物のイソシアネート基の一部又は全部をブロック化剤でブロック化して製造したものが挙げられる。このブロック化剤としては、例えば、ε−カプロラクタム、メチルエチルケトオキシム、メチルイソアミルケトオキシム、メチルイソブチルケトオキシム等のケトオキシム系ブロック化剤、フェノール、クレゾール、カテコール、ニトロフェノール等のフェノール系ブロック化剤、イソプロパノール、トリメチロールプロパン等のアルコール系ブロック化剤、マロン酸エステル、アセト酢酸エステル等の活性メチレン系ブロック化剤、及び３，５−ジメチルピラゾール、１，２，４−トリアゾール等のアゾール系ブロック化剤などが挙げられる。これらのポリブロックイソシアネート化合物は１種用いてもよいし、２種以上を組み合わせて用いてもよい。
ここで、（ｃ）成分のウレタン樹脂硬化剤の含有量は、（ａ）〜（ｃ）成分の全不揮発分総量に対して、０〜６０質量％が好ましく、１〜５０質量％がより好ましく、２〜４０質量％が特に好ましい。（ｃ）成分のウレタン樹脂硬化剤の含有量が６０質量％を越える場合は、オーバークリヤーコート塗膜の密着性を向上することができないため好ましくない。
【００３３】
好ましい透明プライマーは、必要に応じて、（ｄ）成分として内部架橋型樹脂微粒子を含有することもできる。該（ｄ）成分の内部架橋型樹脂微粒子は、透明プライマーを塗装し未架橋の状態でオーバークリヤーコート塗料を塗装した際に、透明プライマーとオーバークリヤーコート塗料との混合を抑制するために用いられ、該成分の含有により高度な外観性を得ることができる。
該（ｄ）成分の内部架橋型樹脂微粒子は、架橋剤成分である多官能ラジカル重合性単量体を必須構成成分とし、必要に応じて、水酸基を有するラジカル重合性単量体及びその他のラジカル重合性単量体を、界面活性剤が形成するミセル中で、ラジカル単独重合もしくはラジカル共重合することにより得ることができる。ここで、一分子中にラジカル重合性二重結合を２つ以上有する多官能ラジカル重合性単量体を必須構成成分としているため、得られる樹脂微粒子は、その内部に架橋構造を有する。内部架橋型樹脂微粒子が水酸基を有する場合は、水酸基と前記透明プライマーの（ｂ）成分のアミノプラスト樹脂あるいは（ｃ）成分のウレタン樹脂硬化剤とが反応して微粒子がその外部においても架橋構造を形成することができる。
【００３４】
かかる多官能ラジカル重合性単量体の具体例としては、例えば、ジビニルベンゼン、ジアリルフタレート、ジアリルテレフタレート、エチレングリコールジアクリレート、エチレングリコールジメタクリレート、ジエチレングリコールジアクリレート、ジエチレングリコールジメタクリレート、トリエチレングリコールジアクリレート、トリエチレングリコールジメタクリレート、ポリエチレングリコールジアクリレート、ポリエチレングリコールジメタクリレート、１，４−ブタンジオールジアクリレート、１，４−ブタンジオールジメタクリレート、１，３−ブチレングリコールジアクリレート、１，３−ブチレングリコールジメタクリレート、１，６−ヘキサンジオールジアクリレート、１，６−ヘキサンジオールジメタクリレート、ネオペンチルグリコールジアクリレート、ネオペンチルグリコールジメタクリレート、２−ヒドロキシ−１，３−ジアクリロキシプロパン、２−ヒドロキシ−１，３−ジメタクリロキシプロパン、２，２−ビス［４−（アクリロキシエトキシ）フェニル］プロパン、２，２−ビス［４−（メタクリロキシエトキシ）フェニル］プロパン、トリメチロールプロパントリアクリレート、トリメチロールプロパントリメタクリレート、テトラメチロールメタントリアクリレート、テトラメチロールメタントリメタクリレート、ペンタエリスリトールトリアクリレート、ペンタエリスリトールトリメタクリレート、ジペンタエリスリトールトリアクリレート、ジペンタエリスリトールトリメタクリレート、ペンタエリスリトールテトラアクリレート、ペンタエリスリトールテトラメタクリレート、ジペンタエリスリトールテトラアクリレート、ジペンタエリスリトールテトラメタクリレート、ジペンタエリスリトールペンタアクリレート、ジペンタエリスリトールペンタメタクリレート、ジペンタエリスリトールヘキサアクリレート、ジペンタエリスリトールヘキサメタクリレート、さらにこれらのうちで活性水素を有するものでイソシアネート化合物で変性したウレタンアクリレート及びウレタンメタクリレートなどが挙げられ、１種又は２種以上の混合物として用いられる。また、水酸基を有するラジカル重合性単量体及びその他のラジカル重合性単量体の具体例としては、それぞれ前記と同じものが挙げられる。
【００３５】
該（ｄ）成分の内部架橋型樹脂微粒子は、これらのラジカル重合性単量体を用いて界面活性剤存在下、乳化重合法により得ることができる。ここで、界面活性剤としては、例えば、アニオン系界面活性剤、カチオン系界面活性剤、非イオン系界面活性剤、両性イオン系界面活性剤などを用いることができる。乳化重合法により水分散系として得られた内部架橋型樹脂微粒子は、非水分散系に転換された後、使用される。
該（ｄ）成分の内部架橋型樹脂微粒子の含有量は、（ａ）〜（ｃ）成分の全不揮発分総量に対して、０〜４０質量％が好ましく、１〜３５質量％がより好ましく、２〜３０質量％が特に好ましい。（ｄ）成分の内部架橋型樹脂微粒子の含有量が４０質量％を越える場合は、最終的に得られる硬化塗膜の外観性が低下するため好ましくない。
さらに、好ましい透明プライマーは、必要に応じて、（ｅ）成分としてケトン系溶剤を含有することもできる。該（ｅ）成分のケトン系溶剤は、下層塗膜表面に形成されている添加剤層を溶解することができ、該成分の含有により高度な密着性を得ることができる。
かかるケトン系溶剤の具体例としては、例えば、アセトン、メチルエチルケトン、メチルイソブチルケトン、メチルアミルケトン、シクロヘキサノン、イソホロンなどが挙げられる。ここで、（ｅ）成分のケトン系溶剤の含有量は、（ａ）〜（ｃ）成分の全不揮発分総量に対して、０〜４０質量％が好ましく、１〜３５質量％がより好ましく、２〜３０質量％が特に好ましい。（ｅ）成分のケトン系溶剤の含有量が４０質量％を越える場合は、最終的に得られる硬化塗膜の外観性が低下するため好ましくない。
【００３６】
なお、本発明に用いる透明プライマーは、そのままで、あるいは必要に応じて、有機溶剤及び／又は各種添加剤、例えば、紫外線吸収剤、光安定剤、酸化防止剤、界面活性剤、表面調整剤、抗発泡剤、硬化反応触媒、帯電防止剤、香料、脱水剤、シランカップリング剤、さらにはポリエチレンワックス、ポリアマイドワックス等のレオロジー調整剤及びセルロースアセテートブチレート等の補完的に添加される樹脂などを添加して使用することができる。
【００３７】
本発明において用いられる着色ベースコート塗料としては、特に限定されるものではなく、溶剤系、水系など各種の着色ベースコート塗料を用いることができる。
着色ベースコート塗料は、樹脂バインダーと顔料とを含有する。樹脂としては、公知のアクリル樹脂、ポリエステル樹脂（アルキド樹脂を含む）及びポリウレタン樹脂、メラミン樹脂等の各種樹脂を挙げることができる。これらの樹脂は１種用いてもよいし、２種以上を組み合わせて用いてもよく、１分子中に反応性官能基を２個以上有する樹脂を２種以上組み合わせて硬化性樹脂組成物とすることが好ましい。特に好ましいものは、水酸基を有するアクリル樹脂あるいはポリエステル樹脂とメラミン樹脂を組み合わせたものである。
【００３８】
また、顔料としては各種の顔料が用いられるが、例えば、それぞれに表面処理を施したアルミニウム、銅、真鍮、青銅、ステンレススチール、あるいは雲母状酸化鉄、鱗片状メタリック粉体、酸化チタンや酸化鉄で被覆された雲母片等の金属顔料、二酸化チタン、酸化鉄、黄色酸化鉄、カーボンブラック等の無機顔料、フタロシアニンブルー、フタロシアニングリーン、キナクリドン系赤色顔料等の有機顔料、沈降性硫酸バリウム、クレー、シリカ、タルク、カオリン、ベントナイト等の体質顔料などが挙げられる。これらの顔料は１種用いてもよいし、２種以上を組み合わせて用いてもよく、その配合割合は通常樹脂固形分１００重量部に対して０．５〜２００重量部であり、好ましくは２〜１００重量部である。
なお、本発明に用いる着色ベースコート塗料は、そのままで、あるいは必要に応じて、水、有機溶剤及び／又は各種添加剤、例えば、紫外線吸収剤、光安定剤、酸化防止剤、界面活性剤、表面調整剤、抗発泡剤、硬化反応触媒、帯電防止剤、香料、脱水剤、シランカップリング剤、さらにはポリエチレンワックス、ポリアマイドワックス、内部架橋型樹脂微粒子等のレオロジー調整剤及びセルロースアセテートブチレート等の補完的に添加される樹脂などを添加して使用することができる。
【００３９】
本発明において用いられるクリヤーコート塗料としては、特に限定されるものではなく、各種のクリヤーコート塗料を用いることができる。クリヤーコート塗料は硬化性樹脂組成物である。樹脂としては、公知のアクリル樹脂、ポリエステル樹脂（アルキド樹脂を含む）及びポリウレタン樹脂、メラミン樹脂等の各種樹脂を挙げることができる。これらの樹脂のうち、１分子中に反応性官能基を２個以上有する樹脂を２種以上組み合わせて硬化性樹脂組成物とする。特に好ましいものは、水酸基を有するアクリル樹脂とメラミン樹脂を組み合わせたものである。
なお、該クリヤーコート塗料は、そのままで、あるいは必要に応じて、有機溶剤及び／又は各種添加剤、例えば、紫外線吸収剤、光安定剤、酸化防止剤、界面活性剤、表面調整剤、抗発泡剤、硬化反応触媒、帯電防止剤、香料、脱水剤、シランカップリング剤、さらにはポリエチレンワックス、ポリアマイドワックス、内部架橋型樹脂微粒子等のレオロジー調整剤などを添加して使用することができる。さらに、必要に応じて、透明性を損なわない程度に前記の顔料あるいは耐候性の良好な染料を添加することもできる。
【００４０】
本発明において用いられる着色上塗り塗料としては、特に限定されるものではなく、各種の着色上塗り塗料を用いることができ、例えば、前記着色ベースコート塗料と同様の着色塗料などが挙げられる。
前記オーバークリヤーコート塗料、透明プライマー、着色ベースコート塗料、クリヤーコート塗料及び着色上塗り塗料は、必要に応じて加温したり、有機溶剤又は反応性希釈剤を添加することにより所望の粘度に調整した後、エアースプレー、静電エアースプレー、ロールコーター、フローコーター、ディッピング形式による塗装機等の通常使用される塗装機、又は刷毛、バーコーター、アプリケーターなどを用いて塗装が行われる。これらのうちスプレー塗装が好ましい。
本発明の塗装仕上げ方法において用いられる基材としては、特に限定されるものではなく、各種の基材を用いることができ、例えば、木、ガラス、金属、布、プラスチック、発泡体、弾性体、紙、セラミック、コンクリート、石膏ボード等の有機素材及び無機素材などが挙げられる。これらの基材は、予め表面処理されたものでもよいし、予め表面に塗膜が形成されたものでもよい。
【００４１】
本発明の塗装仕上げ方法の好適な例は、前記基材上に前記着色ベースコート塗料を前記方法を用いて乾燥後の膜厚が通常５〜４０μｍ、好ましくは７〜３５μｍになるように塗布し、室温〜１００℃の温度で１〜２０分間放置し、次いで前記クリヤーコート塗料を前記方法を用いて乾燥後の膜厚が通常１０〜１００μｍ、好ましくは１０〜６０μｍになるように塗布し、６０〜３００℃の温度で５秒〜２４時間加熱硬化させ、さらに前記透明プライマーを前記方法を用いて乾燥後の膜厚が通常１〜６０μｍ、好ましくは５〜４０μｍになるように塗布し、室温〜１００℃の温度で１〜２０分間放置し、次いで前記オーバークリヤーコート塗料を前記方法を用いて乾燥後の膜厚が通常１〜６０μｍ、好ましくは５〜５０μｍになるように塗布し、６０〜３００℃の温度で５秒〜２４時間加熱硬化させるものである。
【００４２】
また、本発明の塗装仕上げ方法の好適な例は、前記基材上に前記着色上塗り塗料を前記方法を用いて乾燥後の膜厚が通常５〜１００μｍ、好ましくは１０〜６０μｍになるように塗布し、６０〜３００℃の温度で５秒〜２４時間加熱硬化させ、さらに前記透明プライマーを前記方法を用いて乾燥後の膜厚が通常１〜６０μｍ、好ましくは５〜４０μｍになるように塗布し、室温〜１００℃の温度で１〜２０分間放置し、次いで前記オーバークリヤーコート塗料を前記方法を用いて乾燥後の膜厚が通常１〜６０μｍ、好ましくは５〜５０μｍになるように塗布し、６０〜３００℃の温度で５秒〜２４時間加熱硬化させるものである。
なお、透明プライマーを塗布する前に下地となるクリヤーコート塗膜あるいは着色上塗り塗膜表面に対して、布等による乾拭き、有機溶剤を含んだ布等によるワイプ、サンドペーパー等によるサンディングなどの密着性を向上させる処理を行ってもよい。
本発明の塗装仕上げ方法により得られる塗装物品としては、例えば、構造物、木製品、金属製品、プラスチック製品、ゴム製品、加工紙、セラミック製品、ガラス製品などが挙げられる。より具体的には、自動車、自動車用部品（例えば、ボディー、バンパー、スポイラー、ミラー、ホイール、内装材等の部品であって、各種材質のもの）、鋼板等の金属板、二輪車、二輪車用部品、道路用資材（例えば、ガードレール、交通標識、防音壁等）、トンネル用資材（例えば、側壁板等）、船舶、鉄道車両、航空機、家具、楽器、家電製品、建築材料、容器、事務用品、スポーツ用品、玩具などが挙げられる。
【００４３】
【実施例】
次に、本発明を実施例によりさらに具体的に説明するが、本発明はこれらの実施例によって何ら制限されるものではない。なお、本発明の塗装仕上げ方法により得られる塗膜の性能は次のようにして求めた。
（１）外観性
目視観察により、次の基準に従い評価した。
○：塗膜に蛍光灯を映すと、蛍光灯が鮮明に映る。
△：塗膜に蛍光灯を映すと、蛍光灯の周囲（輪郭）がややぼやける。
×：塗膜に蛍光灯を映すと、蛍光灯の周囲（輪郭）が著しくぼやける。
（２）水の接触角
得られた試験板をＪＩＳ Ｋ−５４００（１９９０）９．９の耐候性試験法に準じて屋外で７日間曝露した。その後試験板を洗浄後２０℃で塗膜表面に０．８μｌの脱イオン水の液滴を注射器を用いて乗せ、（株）エルマ製、エルマゴニオメータ式・接触角測定器Ｇ‐Ｉ型を用いて測定した。液滴当り３０、６０、９０秒毎に接触角を測定し、時間と接触角の直線回帰式から０秒へ接触角を外挿し、これを試験板の接触角とした。
【００４４】
（３）耐屋外曝露汚染性
ＪＩＳ Ｋ−５４００（１９９０）９．９の耐候性試験法に準じて屋外にて３ヶ月曝露後、塗膜の未洗浄面の色をＪＩＳ Ｋ−５４００（１９９０）７.４．２塗膜の色−計測法に準じて測定し、曝露後のＬ^＊値から未曝露時のＬ^＊値を引くことにより△Ｌ^＊値を算出し、塗膜の耐汚染性を判定した。ここで、△Ｌ^＊値が０に近いほど耐汚染性に優れることを意味する。
（４）汚染除去性
上記水の接触角と同様の条件で屋外曝露し、洗浄した塗膜に対して、以下に記載の組成の汚染除去性試験液を霧吹きにて均一に塗布した。次に、塗膜に対して４５°の角度から７Ｌ／ｍｉｎの流水を１５秒間かけることにより、汚染除去を行った。その後、塗膜の色をＪＩＳ Ｋ−５４００（１９９０）７．４．２塗膜の色−計測法に準じて測定し、汚染除去後のＬ^＊値から試験液塗布前のＬ^＊値を引くことにより△Ｌ^＊値を算出し、塗膜の汚染除去性を判定した。ここで、△Ｌ^＊値が０に近いほど汚染除去性に優れていることを意味する。
汚染除去性試験液
関東ローム（JIS Z‐8901(1995)試験用粉体Ｉ ８種）０．５質量部
カーボンブラック（JIS Z‐8901(1995)試験用粉体Ｉ １２種）０．５質量部
脱イオン水 ９９．０質量部
（５）耐候性
サンシャインカーボンアーク灯式促進耐候性試験機（ＪＩＳ Ｋ−５４００（１９９０）９．８.１）を用いて３０００時間曝露後、塗膜の状態を目視判定した。
（６）耐水性
試験片を４０℃の温水に２４０時間浸漬し塗膜の状態を目視判定した。
（７）耐酸性
４０質量％硫酸水溶液０．２ｍｌを試験片上にスポット状にのせ、６０℃で３０分間加熱した。この試験片を流水洗浄し、塗膜の異常を目視にて判定した。
（８）密着性
初期及び上記耐候性試験後の塗膜について、ＪＩＳ Ｋ−５４００（１９９０）８．５．２の碁盤目テープ法に準じて付着試験を行い、次の基準に従い密着性を評価した。
○：１０点
△：８点
×：６点以下
【００４５】
＜製造例１，２＞
オーバークリヤーコート塗料の（Ａ）成分の変性樹脂溶液Ａ−１及びＡ−２の製造
温度計、還流冷却器、攪拌機、滴下ロートを備えた4つ口フラスコに、表１に記載の組成のキシレン及びオルガノシリケートの縮合物の混合物（初期仕込み）を仕込み、窒素気流下攪拌しながら加熱し１４０℃を保った。次に、仕込み混合物に撹拌下１４０℃の温度で表１に記載の組成の単量体及び重合開始剤の混合物（滴下成分）を２時間かけて滴下ロートより等速滴下した。滴下終了後、１４０℃の温度で１時間保った後、反応温度を１１０℃に下げた。その後、反応混合物に表１に記載の組成の重合開始剤溶液（追加触媒）を添加し、さらに１１０℃の温度を２時間保ったところで反応を終了し、表１に記載の不揮発分を有する変性樹脂溶液Ａ−１及びＡ−２を得た。
【００４６】
【表１】

表中の添字の物質は、以下に示すものである。
１）商品名、コルコート（株）製、オルガノシリケートの縮合物
【００４７】
＜製造例３＞
オーバークリヤーコート塗料の（Ｂ）成分の硬化剤溶液Ｂ−１の製造
温度計、還流冷却器、攪拌機、滴下ロートを備えた４つ口フラスコにトリメチロールプロパン１３４質量部及びメチルイソブチルケトン４２５．３質量部を仕込み攪拌下で１２０℃に加熱した。次いで、その仕込み混合物に撹拌下１２０℃の温度を保ちながらメチルヘキサヒドロフタル酸無水物５０４質量部を２時間かけて滴下し、混合物の酸価（ピリジン／水＝９／１（重量比）混合液で約５０質量倍に希釈し、９０℃で３０分間加熱処理した溶液を水酸化カリウム標準溶液で滴定）が、１６０以下になるまで加熱攪拌を継続することで不揮発分６０質量％、溶液としてのカルボン酸当量３５５の硬化剤溶液Ｂ−１を得た。
【００４８】
＜製造例４＞
オーバークリヤーコート塗料の（Ｂ）成分の硬化剤溶液Ｂ−２の製造
温度計、還流冷却器、攪拌機、滴下ロートを備えた４つ口フラスコに、メチルアミルケトン８４質量部を仕込み、窒素気流下攪拌しながら加熱し１４０℃を保った。次に、仕込み液に撹拌下１４０℃の温度で以下に記載の組成の単量体及び重合開始剤混合物（滴下成分）を２時間かけて滴下ロートより等速滴下した。
滴下成分
メタクリル酸 ２０質量部
メタクリル酸ｎ−ブチル ３５質量部
アクリル酸ｎ−ブチル ４５質量部
ｔ−ブチルパーオキシ−２−エチルヘキサノエート ５質量部
滴下終了後、その混合物を１４０℃の温度で１時間保った後、反応温度を１１０℃に下げた。その後、反応混合物にｔ−ブチルパーオキシ−２−エチルヘキサノエート１質量部及びメチルアミルケトン１０質量部を添加し、さらに１１０℃の温度を２時間保ったところで反応を終了し、ガードナー粘度（２５℃）Ｒ〜Ｓ、不揮発分５０．４質量％、溶液としてのカルボン酸当量８６０の硬化剤溶液Ｂ−２を得た。
【００４９】
＜製造例５＞
オーバークリヤーコート塗料の（Ｄ）成分の脂肪族スルホン酸化合物のアミン塩溶液Ｄ−１の製造
攪拌器を取りつけた３つ口フラスコに以下に記載の組成の混合物を入れ、室温で攪拌しながら３５質量％塩酸１０４．３質量部を添加して脱ナトリウム化した。この際イオン交換反応は塩酸添加後直ちに進行し、５８．５部のＮａＣｌが析出した。析出したＮａＣｌを吸引ろ過によりろ別した後、ろ液にＮ−メチルモルホリン１０１質量部を加え、等モルのＮ−メチルモルホリンでブロックされた有効成分濃度（脂肪族スルホン酸化合物として）２５質量％の脂肪族スルホン酸化合物のアミン塩溶液Ｄ−１を得た。
ラピゾールＢ９０^２） ４９３．３質量部
ｎ−ブタノール １１３５．９質量部
前記の添字の物質は、以下に示すものである。
２）商品名、日本油脂（株）製、ジオクチルスルホコハク酸ナトリウム（有効分９０質量％）
【００５０】
＜製造例６〜８＞
オーバークリヤーコート塗料ＯＣ−１〜３の製造
表２に記載の組成の原料を混合し、オーバークリヤーコート塗料を作成した。
【表２】

【００５１】
表中の添字の物質は、以下に示すものである。
３）商品名、三菱化学（株）製、オルガノシリケートの縮合物
４）商品名、多摩化学工業（株）製、オルガノシリケートの縮合物
５）商品名、三井化学（株）製、メラミン樹脂溶液（不揮発分６０質量％）
６）テトラｎ−ブチルアンモニウムブロマイドの１０質量％酢酸イソブチル溶液７）チヌビン９００（商品名、チバスペシャルティケミカルス社製）の２０質量％キシレン溶液
８）チヌビン２９２（商品名、チバスペシャルティケミカルス社製）の２０質量％キシレン溶液
９）ＢＹＫ−３００（商品名、ビックケミー社製）の１０質量％キシレン溶液
１０）商品名、エッソ社製、芳香族石油ナフサ
【００５２】
＜製造例９，１０＞
透明プライマーの（ａ）成分のアクリル樹脂溶液ａ−１及びａ−２の製造
温度計、還流冷却器、攪拌機、滴下ロートを備えた4つ口フラスコに、表３に記載の組成の溶剤の混合物（初期仕込み）を仕込み、窒素気流下攪拌しながら加熱し１４０℃を保った。次に、その仕込み混合物に撹拌下１４０℃の温度で表３に記載の組成の単量体及び重合開始剤の混合物（滴下成分）を２時間かけて滴下ロートより等速滴下した。滴下終了後、その混合物を１４０℃の温度で１時間保った後、反応温度を１１０℃に下げた。その後、反応混合物に表３に記載の組成の重合開始剤溶液（追加触媒）を添加し、さらに１１０℃の温度を２時間保ったところで反応を終了した。最後に、表３に記載のキシレン（希釈溶剤）を添加し、表３に記載の不揮発分を有するアクリル樹脂溶液ａ−１及びａ−２を得た。
【００５３】
【表３】

表中の添字の物質は、以下に示すものである。
１１）商品名、ダイセル化学工業（株）製、ε−カプロラクトン２ｍｏｌ変性メタクリル酸２−ヒドロキシエチル
【００５４】
＜製造例１１＞
透明プライマーの（ｄ）成分の内部架橋型樹脂微粒子分散液ｄ−１の製造
温度計、還流冷却器、攪拌機、２つの滴下ロートを備えた５つ口フラスコに、イオン交換水７６．２質量部及びラピゾールＢ９０（商品名、日本油脂（株）製、ジオクチルスルホコハク酸ナトリウム、有効分９０質量％）１．８質量部を仕込み、窒素気流下攪拌しながら加熱し８０℃を保った。ラピゾールＢ９０が完全に溶解した後、その仕込み混合物に過硫酸カリウム２質量％の水溶液１．２質量部を添加し、その５分後より８０℃の温度で以下に記載の組成のコア部単量体混合物（滴下成分１）を１．５時間かけて滴下ロートより等速滴下した。滴下終了後、その混合Ｂつを８０℃の温度で３０分間保った後、８０℃の温度で以下に記載の組成のシェル部単量体混合物（滴下成分２）を１．５時間かけて滴下ロートより等速滴下した。一方、これと同時に、コア部単量体混合物（滴下成分１）滴下開始１時間後より、過硫酸カリウム２質量％の水溶液１．２質量部を２．５時間かけてもうひとつの滴下ロートより等速滴下した。
【００５５】
滴下成分１
アクリル酸エチル ６．０質量部
エチレングリコールジメタクリレート ２．３質量部
ジビニルベンゼン １．７質量部
滴下成分２
アクリル酸エチル ４．１質量部
メタクリル酸２−ヒドロキシプロピル ２．６質量部
エチレングリコールジメタクリレート ３．３質量部
【００５６】
前記単量体混合物及び過硫酸カリウム水溶液滴下終了後、窒素気流下８０℃で２時間攪拌を行い、内部架橋型樹脂微粒子水分散液を得た。冷却後、その内部架橋型樹脂微粒子水分散液に攪拌下トルエン２質量部、ｎ−ブタノール３８質量部及びイソプロパノール１０質量部を順に加え、さらに２６質量％水酸化ナトリウム２．２質量部を添加し、２時間還流を行った。次いで、７６質量％蟻酸水溶液０．９質量部を加え３０分間攪拌した後、イソプロパノール５質量部を添加し、３０分間放置し分離した水層を除去した。次に、残った有機層にイオン交換水４０質量部を加え３０分間攪拌した後、イソプロパノール５質量部を添加し、３０分間放置し分離した水層を再び除去した。この操作を再度行った後、前記アクリル樹脂溶液ａ−２を４０質量部及びメチルイソブチルケトン４９質量部を加え共沸脱水し、沸点が１０５℃以上になるまで水層のみを除去した後、固形分が３０質量％になるまで減圧下で溶媒を留去し、内部架橋型樹脂微粒子分散液ｄ−１を得た。
【００５７】
＜製造例１２〜１５＞
透明プライマーＰＲ−１〜４の製造
表４に記載の組成の原料を混合し、透明プライマーを作成した。
【表４】

【００５８】
表中の添字の物質は、以下に示すものである。
１２）商品名、三井化学（株）製、メラミン樹脂溶液（不揮発分６０質量％）
１３）商品名、三井化学（株）製、メラミン樹脂溶液（不揮発分６０質量％）
１４）商品名、住友バイエルウレタン（株）製、ポリブロックイソシアネート化合物溶液（不揮発分７５質量％）
１５）商品名、住友バイエルウレタン（株）製、ポリブロックイソシアネート化合物溶液（不揮発分６５質量％）
１６）ジブチル錫ジラウレートの１０質量％キシレン溶液
１７）チヌビン９００（商品名、チバスペシャルティケミカルス社製）の２０質量％キシレン溶液
１８）チヌビン２９２（商品名、チバスペシャルティケミカルス社製）の２０質量％キシレン溶液
１９）ＢＹＫ−３００（商品名、ビックケミー社製）の１０質量％キシレン溶液
【００５９】
＜実施例１〜３＞
溶剤系着色ベースコート塗料／クリヤー塗料上での試験片の作成及び塗膜性能の検討
リン酸亜鉛処理軟鋼板にカチオン電着塗料アクアＮｏ．４２００（商品名、日本油脂（株）製）を乾燥膜厚２０μｍとなるよう電着塗装して１７５℃で２５分間焼き付け、さらに中塗り塗料ＨＳ−Ｈ３００（商品名、日本油脂（株）製）を乾燥膜厚３０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けた。次に、溶剤系着色ベースコート塗料ベルコートＮｏ．６０００（商品名、日本油脂（株）製、塗色：白）を乾燥膜厚１５μｍとなるようエアスプレー塗装し２０℃で３分間セット後、さらにクリヤーコート塗料ベルコートＮｏ．６１００（商品名、日本油脂（株）製）をウェット・オン・ウェット方式で乾燥膜厚４０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けた。次に、実施例１及び４については、得られた塗膜表面に対してアセトンを含ませた布によりそれぞれワイプを行った。その後、前記透明プライマーＰＲ−２〜４をシンナー（ソルベッソ１００（商品名、エッソ社製、芳香族石油ナフサ）／酢酸ブチル＝５／５（質量比））で塗装粘度（フォードカップＮｏ．４、２０℃で１２秒）に希釈したものをそれぞれ乾燥膜厚１０μｍとなるようエアスプレー塗装し２０℃で３分間セット後、さらに前記オーバークリヤーコート塗料ＯＣ−１〜３をシンナー（ソルベッソ１００（商品名、エッソ社製、芳香族石油ナフサ））で塗装粘度（フォードカップＮｏ．４、２０℃で２５秒）に希釈したものをウェット・オン・ウェット方式でそれぞれ乾燥膜厚４０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けて試験片を作成した。ただし、実施例１〜３のいずれの場合も耐水性及び耐酸性の試験板は、ベースコート塗料の塗色を黒とした。塗膜性能を表５に示すが、いずれの場合も均一でツヤのある塗膜が得られ、優れた外観性、親水性、耐屋外曝露汚染性、汚染除去性、耐候性、耐水性、耐酸性、密着性を示した。
【００６０】
【表５】

【００６１】
＜実施例４，５＞
水系着色ベースコート塗料／クリヤー塗料上での試験片の作成及び塗膜性能の検討
リン酸亜鉛処理軟鋼板にカチオン電着塗料アクアＮｏ．４２００（商品名、日本油脂（株）製）を乾燥膜厚２０μｍとなるよう電着塗装して１７５℃で２５分間焼き付け、さらに中塗り塗料ＨＳ−Ｈ３００（商品名、日本油脂（株）製）を乾燥膜厚３０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けた。次に、水系着色ベースコート塗料アクアＢＣ−３（商品名、日本油脂（株）製、塗色：白）を乾燥膜厚１５μｍとなるようエアスプレー塗装し２０℃で３分間セット後８０℃で１０分間フラッシュした。試験片が室温となるまで放冷した後、クリヤーコート塗料ベルコートＮｏ．６１００（商品名、日本油脂（株）製）を乾燥膜厚４０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けた。次に、実施例５については、得られた塗膜表面に対してアセトンを含ませた布によりワイプを行った。その後、前記透明プライマーＰＲ−２及び３をシンナー（ソルベッソ１００（商品名、エッソ社製、芳香族石油ナフサ）／酢酸ブチル＝５／５（質量比））で塗装粘度（フォードカップＮｏ．４、２０℃で１２秒）に希釈したものをそれぞれ乾燥膜厚１０μｍとなるようエアスプレー塗装し２０℃で３分間セット後、さらに前記オーバークリヤーコート塗料ＯＣ−２及び３をシンナー（ソルベッソ１００（商品名、エッソ社製、芳香族石油ナフサ））で塗装粘度（フォードカップＮｏ．４、２０℃で２５秒）に希釈したものをウェット・オン・ウェット方式でそれぞれ乾燥膜厚４０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けて試験片を作成した。ただし、実施例４及び５のいずれの場合も耐水性及び耐酸性の試験板は、ベースコート塗料の塗色を黒とした。塗膜性能を表６に示すが、いずれの場合も均一でツヤのある塗膜が得られ、優れた外観性、親水性、耐屋外曝露汚染性、汚染除去性、耐候性、耐水性、耐酸性、密着性を示した。
【００６２】
【表６】

【００６３】
＜実施例６＞
着色上塗り塗料上での試験片の作成及び塗膜性能の検討
リン酸亜鉛処理軟鋼板にカチオン電着塗料アクアＮｏ．４２００（商品名、日本油脂（株）製）を乾燥膜厚２０μｍとなるよう電着塗装して１７５℃で２５分間焼き付け、さらに中塗り塗料ＨＳ−Ｈ３００（商品名、日本油脂（株）製）を乾燥膜厚３０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けた。次に、着色上塗り塗料メラミＮｏ．２０００（商品名、日本油脂（株）製、塗色：白）を乾燥膜厚４０μｍとなるようエアスプレー塗装し１４０℃で３０分間焼き付けた。次に、実施例７については、得られた塗膜表面に対してアセトンを含ませた布によりワイプを行った。その後、前記透明プライマーＰＲ−１及び４をシンナー（ソルベッソ１００（商品名、エッソ社製、芳香族石油ナフサ）／酢酸ブチル＝５／５（質量比））で塗装粘度（フォードカップＮｏ．４、２０℃で１２秒）に希釈したものをそれぞれ乾燥膜厚１０μｍとなるようエアスプレー塗装し２０℃で３分間セット後、さらに前記オーバークリヤーコート塗料ＯＣ−１をシンナー（ソルベッソ１００（商品名、エッソ社製、芳香族石油ナフサ））で塗装粘度（フォードカップＮｏ．４、２０℃で２５秒）に希釈したものをウェット・オン・ウェット方式でそれぞれ乾燥膜厚４０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けて試験片を作成した。塗膜性能を表７に示すが、いずれの場合も均一でツヤのある塗膜が得られ、優れた外観性、親水性、耐屋外曝露汚染性、汚染除去性、耐候性、密着性を示した。
【００６４】
【表７】

【００６５】
＜比較製造例１＞
比較用オーバークリヤーコート塗料の（Ａ）成分のアクリル樹脂溶液Ａ−３の製 造
温度計、還流冷却器、攪拌機、滴下ロートを備えた４つ口フラスコに、キシレン７５質量部を仕込み、窒素気流下攪拌しながら加熱し１４０℃を保った。次に、仕込み液に撹拌下１４０℃の温度で以下に記載の組成の単量体及び重合開始剤の混合物（滴下成分）を２時間かけて滴下ロートより等速滴下した。
滴下成分
メタクリル酸グリシジル １８質量部
アクリル酸ｎ−ブチル １８質量部
メタクリル酸メチル ２５質量部
メタクリル酸２−ヒドロキシエチル ４質量部
アクリル酸２−メトキシエチル ２０質量部
ｔ−ブチルパーオキシ−２−エチルヘキサノエート ２質量部
滴下終了後、その反応混合物に１４０℃の温度を１時間保った後、反応温度を１１０℃に下げた。その後、その反応混合物にｔ−ブチルパーオキシ−２−エチルヘキサノエート０．２質量部及びキシレン４．５質量部を添加し、さらに１１０℃の温度で２時間保ったところで反応を終了し、不揮発分５１．３質量％のアクリル樹脂溶液Ａ−３を得た。
【００６６】
比較用オーバークリヤーコート塗料ＯＣ−４及び５の製造
表８に記載の組成の原料を混合し、比較用オーバークリヤーコート塗料を作成した。
【表８】

【００６７】
表中の添字の物質は、以下に示すものである。
２０）商品名、多摩化学工業（株）製、オルガノシリケートの縮合物
２１）商品名、三井化学（株）製、メラミン樹脂溶液（不揮発分６０質量％）
２２）テトラｎ−ブチルアンモニウムブロマイドの１０質量％酢酸イソブチル溶液
２３）チヌビン９００（商品名、チバスペシャルティケミカルス社製）の２０質量％キシレン溶液
２４）チヌビン２９２（商品名、チバスペシャルティケミカルス社製）の２０質量％キシレン溶液
２５）ＢＹＫ−３００（商品名、ビックケミー社製）の１０質量％キシレン溶液２６）商品名、エッソ社製、芳香族石油ナフサ
【００６８】
＜比較例１〜４＞
溶剤系着色ベースコート塗料／クリヤー塗料上での試験片の作成及び塗膜性能の検討
リン酸亜鉛処理軟鋼板にカチオン電着塗料アクアＮｏ．４２００（商品名、日本油脂（株）製）を乾燥膜厚２０μｍとなるよう電着塗装して１７５℃で２５分間焼き付け、さらに中塗り塗料ＨＳ−Ｈ３００（商品名、日本油脂（株）製）を乾燥膜厚３０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けた。次に、溶剤系着色ベースコート塗料ベルコートＮｏ．６０００（商品名、日本油脂（株）製、塗色：白）を乾燥膜厚１５μｍとなるようエアスプレー塗装し２０℃で３分間セット後、さらにクリヤーコート塗料ベルコートＮｏ．６１００（商品名、日本油脂（株）製）をウェット・オン・ウェット方式で乾燥膜厚４０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けた。次に、比較例２〜４については、得られた塗膜表面に対してアセトンを含ませた布によりそれぞれワイプを行った。その後、比較例２及び３については、前記透明プライマーＰＲ−２をシンナー（ソルベッソ１００（商品名、エッソ社製、芳香族石油ナフサ）／酢酸ブチル＝５／５（質量比））で塗装粘度（フォードカップＮｏ．４、２０℃で１２秒）に希釈したものをそれぞれ乾燥膜厚１０μｍとなるようエアスプレー塗装し２０℃で３分間セット後、さらに前記オーバークリヤーコート塗料ＯＣ−５及び６をシンナー（ソルベッソ１００（商品名、エッソ社製、芳香族石油ナフサ））で塗装粘度（フォードカップＮｏ．４、２０℃で２５秒）に希釈したものをウェット・オン・ウェット方式でそれぞれ乾燥膜厚４０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けて試験片を作成した。また、比較例４については、透明プライマーを塗布せずに、前記オーバークリヤーコート塗料ＯＣ−４をシンナー（ソルベッソ１００（商品名、エッソ社製、芳香族石油ナフサ））で塗装粘度（フォードカップＮｏ．４、２０℃で２５秒）に希釈したものを乾燥膜厚４０μｍとなるようエアスプレー塗装し、１４０℃で３０分間焼き付けて試験片を作成した。ただし、比較例１〜４のいずれの場合も耐水性の試験板のみは、ベースコート塗料の塗色を黒とした。
【００６９】
塗膜性能を表９に示すが、まず、比較例１においては、オーバークリヤーコート塗料が何ら塗布されていないため、親水性とならず、耐屋外曝露汚染性及び汚染除去性に劣った。比較例２においては、オーバークリヤーコート塗料の（Ａ）成分が何ら変性されていないため、耐候性及び耐水性に劣った。また、比較例３においては、オーバークリヤーコート塗料に（Ｃ）成分のオルガノシリケート及び／又はその縮合物が何ら添加されていないため、親水性とならず、耐屋外曝露汚染性及び汚染除去性に劣った。さらに、比較例４においては、透明プライマーが何ら塗布されていないため、密着性に劣った。
【００７０】
【表９】

【００７１】
【発明の効果】
本発明の塗装仕上げ方法は、耐汚染性、汚染除去性、耐候性、耐水性、耐化学性、外観性及び密着性に優れた塗膜を与える。また、本発明の塗装物品は、前記塗装仕上げ方法により塗装された物品であり、前記塗膜性能に優れている。[0001]
BACKGROUND OF THE INVENTION
In the present invention, a colored base coat paint is applied onto a base material, a clear coat paint is applied in an uncrosslinked state, and after baking, a transparent primer is further applied, and an over clear coat paint is applied in an uncrosslinked state. Paint finish method for painting and baking, and paint finish method for painting and baking after painting and baking a colored top coat on a substrate, and then painting an over-clear coat paint in an uncrosslinked state And a coated article. More specifically, particularly in the automotive coating field, a paint finishing method that gives a coating film excellent in stain resistance, decontamination resistance, weather resistance, water resistance, chemical resistance, appearance, and adhesion, and the paint finishing method It is related with the coated article painted by.
[0002]
[Prior art]
Currently, automobile users want to maintain the beautiful appearance of the new car, and in order to remove dirt, which is an impediment to it, washing with water using a detergent, wiping off moisture, and removing dirt with glossy water repellent wax Is going.
However, this operation takes several hours and is a considerable burden on the user. In particular, since wax is mainly water-repellent, the adhesion work during rainfall is large and the dirt does not come off regardless of whether the dirt is hydrophilic or hydrophobic. In some cases, it becomes unsightly and the maintenance of the user's corners may be wasted in a day. That is, the user desires a product that reduces the maintenance burden. In addition, due to the recent increase in environmental protection awareness, there is concern about water pollution due to river runoff of detergents and petroleum waxes, and there are countries where car washing at home is prohibited in Europe.
Against this backdrop, research has been conducted on coatings and post-treatment agents that can remove dirt by rain, thereby reducing the frequency of user washing and removing dirt without using detergent. For this purpose, it has been proposed that the adhesion work of dirt in water is reduced, that is, the surface energy of the coating film is increased and hydrophilicity is good (Paint Engineering Vol.31 No.7, pages 260-320). (1996). As a specific method for hydrophilizing the coating film, for example, International Publication No. WO94 / 06870 discloses a coating composition obtained by blending a specific organic coating composition with a specific organosilicate and / or a condensate thereof. It is disclosed that a coating film having a water contact angle of 70 degrees or less after acid treatment is obtained. Further, International Publication No. WO 97/23572 discloses that high hydrophilicity can be imparted by applying a photocatalytic coating to the surface of a substrate.
[0003]
However, in the method of International Publication No. WO94 / 06870, it takes a long time to make the coating hydrophilic after forming a coating film. Unlike a structure, the vehicle is required to express its function immediately after purchase. Absent. In addition, since the silicate exists as a large island inside the coating film, it tends to whiten due to the difference in refractive index from the binder, or when it touches water, the island silicate tends to absorb water and cause whitening, resulting in high appearance. It is fatal for automobile paints that require durability. In addition, the water contact angle of the acid-treated coating film is 56 °, which is the lowest in the examples, and the degree of hydrophilicity is not sufficient, and hydrophobic soil such as carbon can be removed only by a spray car wash of 30 ° or less. In the sense of a maintenance easy coating with a contact angle, it is much less.
[0004]
In addition, in the method of International Publication No. WO97 / 23572, when irradiated with light, the coating film can be highly hydrophilized, but vertical surfaces such as doors cannot receive enough light, and are stored at night and in garage storage. If the light irradiation is interrupted, the effect may be reduced or disappear, and the effect is uneven and not sufficient. In addition, hydroxy radicals and superoxide ions generated by the photocatalytic reaction deteriorate the organic coating underneath, and are not suitable for automobiles that require long-term weather resistance. This can be dealt with by periodically performing repainting maintenance, but the maintenance cost of the user increases, which is undesirable in terms of cost.
[0005]
[Problems to be solved by the invention]
The object of the present invention is to provide high hydrophilicity immediately after the formation of the coating film, which is not only self-cleaning due to rain, but also has a function of removing dirt even if it is dirty only by spray car washing. It is in providing the coating finishing method which can be provided with property, chemical resistance, external appearance property, and adhesiveness, and the coated article obtained by the method.
[0006]
[Means for Solving the Problems]
  As a result of intensive research to develop a paint finishing method having the above-mentioned preferable properties, the present inventors applied a colored base coat paint on a substrate and applied a clear coat paint in an uncrosslinked state. In the coating finishing method, in which an over clear coat paint is further applied in an uncrosslinked state and then baked, the over clear coat paint is (A) a specific organosilicate and / or a condensate thereof. Modified resin obtained by polymerizing a polymerizable monomer mixture for synthesizing acrylic resin containing both a radical polymerizable monomer having a hydroxyl group and a radical polymerizable monomer having an epoxy group in the presence of (B) carboxyl group blocked with carboxyl group, carboxylic anhydride group and alkyl vinyl ether compound Compounds having at least one functional group selected, and the (C) specific organosilicate and / or its condensate as essential components,further(D) An aliphatic sulfonic acid compound or an amine salt of an aliphatic sulfonic acid compound, and / or (E) a stain-resistant coating composition comprising an aminoplast resin, or a paint finishing method, In the paint finishing method, after painting and baking a colored top coat on a substrate, then painting a transparent primer, and painting and baking the over clear coat paint in an uncrosslinked state, the over clear coat paint is (A) specified. Polymerizable monomer mixture for synthesizing acrylic resins containing both a radical polymerizable monomer having a hydroxyl group and a radical polymerizable monomer having an epoxy group in the presence of an organosilicate and / or a condensate thereof Modified resin obtained by polymerizing carboxylic acid, (B) carboxyl group, carboxylic anhydride group and alkyl vinyl ether compound And in a compound having at least one functional group selected from the blocked carboxyl group, and (C) and a specific organosilicate and / or essential components condensates thereof,further(D) An aliphatic sulfonic acid compound or an amine salt of an aliphatic sulfonic acid compound, and / or (E) an anti-stain coating composition comprising an aminoplast resin. It has been found that the object can be achieved, and the present invention has been completed based on these findings.
[0007]
  That is, the present invention applies a colored base coat paint on a substrate, paints a clear coat paint in an uncrosslinked state, bakes it, and then paints a transparent primer, and then overcoats in an uncrosslinked state. In a paint finishing method in which a paint is applied and baked, the over-clear coat paint is represented by (A) general formula (1)
    (R¹)_m-Si- (OR²)_4-m        (1)
(R in the formula¹And R²Are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group, which may be the same or different, and m is 0 or 1. In the presence of an organosilicate and / or a condensate thereof represented by) for polymerization of an acrylic resin containing both a radical polymerizable monomer having a hydroxyl group and a radical polymerizable monomer having an epoxy group. A modified resin obtained by polymerizing a monomer mixture, (B) a compound having at least one functional group selected from a carboxyl group blocked with a carboxyl group, a carboxylic anhydride group and an alkyl vinyl ether compound; C) General formula (2)
  (R³)_n-Si- (OR⁴)_4-n        (2)
(R in the formula³And R⁴Are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group, which may be the same or different, and n is 0 or 1. ) As an essential component, and / or a condensate thereof,further(D) An aliphatic sulfonic acid compound or an amine salt of an aliphatic sulfonic acid compound and / or (E) an anti-staining coating composition comprising an aminoplast resin. To do.
[0008]
  Further, the present invention provides a paint finishing method in which a colored top coat is applied and baked on a substrate, and then a transparent primer is applied, and an over clear coat paint is applied and baked in an uncrosslinked state. Paint (A) General formula (1)
    (R¹)_m-Si- (OR²)_4-m        (1)
(R in the formula¹And R²Are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group, which may be the same or different, and m is 0 or 1. In the presence of an organosilicate and / or a condensate thereof represented by) for polymerization of an acrylic resin containing both a radical polymerizable monomer having a hydroxyl group and a radical polymerizable monomer having an epoxy group. A modified resin obtained by polymerizing a monomer mixture, (B) a compound having at least one functional group selected from a carboxyl group blocked with a carboxyl group, a carboxylic anhydride group and an alkyl vinyl ether compound; C) General formula (2)
  (R³)_n-Si- (OR⁴)_4-n        (2)
(R in the formula³And R⁴Are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group, which may be the same or different, and n is 0 or 1. ) As an essential component, and / or a condensate thereof,further(D) An aliphatic sulfonic acid compound or an amine salt of an aliphatic sulfonic acid compound and / or (E) an anti-staining coating composition comprising an aminoplast resin. To do.
[0009]
Further, the present invention provides the above stain-resistant paint finishing method, wherein the overclear coat paint has a non-volatile content ratio of (A) component of 3 to 80% by mass, (B) component of 3 to 80% by mass, and (C) component. Is provided at a ratio of 0.1 to 30% by mass.
Further, the present invention provides the above stain-resistant paint finishing method, wherein at least one of the side chains of the modified resin as the component (A) of the overclear coat paint is represented by the general formula (3):
[Chemical formula 2]

(R in the formula⁵And R⁶Is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and y is an integer of 1 to 10. And a paint finishing method characterized by being an organic group represented by
[0010]
Further, the present invention provides the above stain-resistant paint finishing method, wherein the transparent primer includes (a) an acrylic resin having both a hydroxyl group and an epoxy group, (b) an aminoplast resin, and (c) a urethane resin curing agent as essential components. And (d) an internally-crosslinked resin fine particle and / or (e) a ketone-based solvent which is optionally used.
Further, the present invention provides the above stain-resistant paint finishing method, wherein the transparent primer has a non-volatile content ratio of (a) component of 40 to 80% by mass, (b) component of 0 to 60% by mass, and (c) component of 0. It provides the coating finishing method characterized by containing in the ratio of -60 mass%.
[0011]
The present invention also provides a coated article characterized by being coated by the above stain-resistant paint finishing method.
Still other objects, aspects and advantages of the present invention will be fully appreciated from the following description.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The modified resin of the component (A) of the stain-resistant paint composition (hereinafter sometimes simply referred to as paint composition) used as an overclear coat paint in the paint finishing method of the present invention makes the paint film hydrophilic. (C), the organosilicate and / or the condensate thereof, which are necessary for this, are uniformly dispersed in the coating film and used to achieve both hydrophilic expression and improved water resistance. As such a modified resin, the general formula (1)
(R¹)_m-Si- (OR²)_4-m        (1)
(R in the formula¹And R²Are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group, and m is 0 or 1. ) In the presence of the organosilicate and / or condensate thereof, a radically polymerizable monomer having a hydroxyl group, a radically polymerizable monomer having an epoxy group, and other radically polymerizable monomers that are optionally used It can be obtained by subjecting a mixture of monomers to ordinary radical copolymerization in an organic solvent. Since this radical polymerizable monomer mixture is a polymerizable monomer mixture for synthesizing acrylic resins, the acrylic polymerizable monomer is contained in at least 50% by mass, preferably 75% by mass, Preferably it contains 90 mass% or more.
[0013]
Preferable specific examples of the organosilicate represented by the general formula (1) include, for example, tetrahydroxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetraphenoxysilane, dimethoxydiethoxysilane, methyl Trimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, butyltrimethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane, ethoxytrimethoxysilane, propoxytrimethoxysilane, butoxytrimethoxysilane, etc. Can be mentioned.
Further, the organosilicate condensate is one or two or more branched or linear condensates of the organosilicate represented by the general formula (1), and has a weight average molecular weight of 200 to 2000. The thing in the range of these is preferable, and the thing in the range of 300-1500 is especially preferable. Commercially available products of organosilicate condensates include MKC silicate MS51, MS56, MS57, MS56S, MS58B15, ES40, EMS31, BTS (all trade names, manufactured by Mitsubishi Chemical Corporation), methyl silicate 51, ethyl silicate 40, Ethyl silicate 40T, ethyl silicate 48, EMS-485 (all trade names, manufactured by Colcoat Co., Ltd.), ethyl silicate 40, 45 (all trade names, manufactured by Tama Chemical Industry Co., Ltd.), etc. A commercially available silicate condensate obtained by further condensing in the presence of a small amount of water can also be used.
The organosilicate represented by the general formula (1) and / or its condensate is preferably used in the range of 1 to 70% by mass in the modified resin of the component (A), more preferably 1.5 to 50% by mass. Desirably, 2 to 40% by mass is particularly desirable. When the organosilicate and / or condensate thereof is less than 1% by mass, the water resistance of the finally obtained cured coating film is unfavorable, and when it exceeds 70% by mass, the modification reaction is performed. Since it becomes easy to gelatinize, it is not preferable.
[0014]
Specific examples of the radical polymerizable monomer having a hydroxyl group include, for example, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxy methacrylate. Ethyl, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, allyl alcohol, an adduct of acrylic acid and versic acid glycidyl ester, an adduct of methacrylic acid and versatic acid glycidyl ester; acrylic acid 2-hydroxyethyl, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, meta Ε-caprolactone adduct of 3-hydroxypropyl toluate or 4-hydroxybutyl methacrylate; 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, methacryl Examples include 2-hydroxyethyl acid, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, or 4-hydroxybutyl methacrylate, an ethylene oxide and / or propylene oxide adduct, and one or a mixture of two or more. Used as
[0015]
Specific examples of the radical polymerizable monomer having an epoxy group include glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, and the like. And used as a mixture of one or more.
Here, the radically polymerizable monomer having a hydroxyl group is desirably used in the range of 1 to 30% by mass in the total monomer constituting the acrylic resin structure portion of the modified resin (A). 5 to 15% by mass is more desirable, and 2 to 7% by mass is particularly desirable. When the radically polymerizable monomer is less than 1% by mass, the water resistance of the finally obtained cured coating film is lowered, which is not preferable. When it exceeds 30% by mass, gelation occurs during the modification reaction. Since it becomes easy, it is not preferable.
The radical polymerizable monomer having an epoxy group is desirably used in the range of 1 to 70% by mass in the total monomers constituting the acrylic resin structure portion of the modified resin (A). -60 mass% is more desirable, and 10-50 mass% is especially desirable. When the radical polymerizable monomer is less than 1% by mass, the finally obtained cured coating film is insufficient in solvent resistance, and when it exceeds 70% by mass, it is not preferable. Since crack resistance falls, it is not preferable.
[0016]
Specific examples of other radical polymerizable monomers include, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, Hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, alkyl acrylate esters such as stearyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, N-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, lauric methacrylate Le, alkyl methacrylate esters such as stearyl methacrylate, styrene, acrylonitrile, methacrylonitrile, acrylamide, and methacrylic amide and the like, used alone or as a mixture of two or more thereof.
Moreover, as a monomer which comprises the acrylic resin structure part of the modified resin of (A) component, the radically polymerizable monomer containing the organic group shown by General formula (3) can also be used.
[0017]
[Chemical Formula 3]

[0018]
(R in the formula⁵And R⁶Is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and y is an integer of 1 to 10. )
Specific examples of such radical polymerizable monomers include, for example, 2-methoxypropyl acrylate, 2-methoxyethyl acrylate, 2-ethoxypropyl acrylate, 2-ethoxyethyl acrylate, 2-methoxypropyl methacrylate, 2-methoxyethyl methacrylate, 2-ethoxypropyl methacrylate, 2-ethoxyethyl methacrylate, Blemmer PME-100, -200, -400, Blemmer PE-90, -200, -350, Blemmer PP-1000, -500 (Both are trade names, manufactured by Nippon Oils and Fats Co., Ltd.) and the like, and are obtained as one kind or a mixture of two or more kinds. The radically polymerizable monomer containing the organic group represented by the general formula (3) is effective in orienting the surface of the coating film even if a small amount of the organosilicate of component (C) and / or its condensate is provided. It is useful to make it express, and it is desirable to be used within a range of 0 to 40% by mass with respect to all monomers constituting the acrylic resin structure part of the modified resin (A), and 1 to 35% by mass Is more desirable, and 2 to 30% by mass is particularly desirable. Here, when the radical polymerizable monomer exceeds 40% by mass, the polarity of the coating film is too high, and the smoothness and water resistance are lowered.
[0019]
As the modified resin of component (A), a method of reacting the organosilicate represented by the general formula (1) and / or its condensate after synthesizing the acrylic resin structural part is also conceivable. In this case, the organosilicate and / or its This is not preferable because the condensate is liberated and remains in an island shape in the coating film, which may impair the appearance.
Moreover, in the stain-resistant coating composition used in the present invention, the modified resin of the component (A) is used within a range of 3 to 80% by mass with respect to the total non-volatile content of the components (A) to (C). Is desirable, 10 to 75 mass% is more desirable, and 20 to 70 mass% is particularly desirable. Here, when the component (A) is less than 3% by mass, the finally obtained cured coating film is not preferable because the stain resistance is insufficient, and when it exceeds 80% by mass, the water resistance of the cured coating film is not preferable. This is not preferable because the properties are lowered.
[0020]
The component (B) of the stain-resistant coating composition used as an overclear coating composition in the paint finishing method of the present invention is a compound that undergoes a thermosetting reaction with the modified resin of the component (A), and has a carboxyl group and a carboxylic acid anhydride. And a compound having at least one functional group selected from a carboxyl group blocked with a group and an alkyl vinyl ether compound (hereinafter sometimes simply referred to as a curing agent). In a specific example of such a curing agent, examples of the compound having a carboxyl group include succinic acid, malonic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, decamethylene dicarboxylic acid, dimer acid, phthalic acid, maleic acid, Examples include trimellitic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, and methylhexahydrophthalic acid. Further, as other compounds having a carboxyl group, (1) a polyol having one or more, preferably 2 to 50, hydroxyl groups per molecule and half-esterified with a carboxylic acid anhydride, (2) an isocyanate per molecule 3. Addition of a polyisocyanate compound having one or more groups, preferably 2 to 50, and a hydroxycarboxylic acid or an amino acid, (3) homopolymerization of a carboxyl group-containing radical polymerizable monomer or other radical polymerizable monomer And (4) a compound obtained by a method such as synthesis of a polyester resin having a carboxyl group terminal. Examples of the compound having a carboxylic anhydride group include carboxylic anhydride in one molecule such as succinic anhydride, phthalic anhydride, hexahydrophthalic anhydride, methylated hexahydrophthalic anhydride, and tetrahydrophthalic anhydride. In addition to a compound having one physical group, a radical polymerizable monomer having an acid anhydride group, for example, a copolymer of maleic anhydride, itaconic anhydride and the like with another radical polymerizable monomer can be mentioned. It is done.
[0021]
Furthermore, examples of the compound having a carboxyl group blocked with an alkyl vinyl ether compound include compounds obtained by blocking the carboxyl group of the compound having a carboxyl group with an alkyl vinyl ether compound. Specific examples of the alkyl vinyl ether compound include, for example, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, pentyl vinyl ether, hexyl vinyl ether, isohexyl vinyl ether, cyclohexyl vinyl ether, 2 1,3-dihydrofuran, 3,4-dihydrofuran, 3,4-dihydro-2H-pyran, 3,4-dihydro-2-methoxy-2H-pyran, 3,4-dihydro-4,4-dimethyl-2H -Pyran-2-one, 3,4-dihydro-2-ethoxy-2H-pyran and the like.
In the stain-resistant coating composition used in the present invention, the content of the curing agent of the component (B) is preferably 3 to 80% by mass with respect to the total non-volatile content of the components (A) to (C). 70 mass% is more preferable, and 10-60 mass% is especially preferable. When the component (B) is less than 3% by mass, the finally obtained cured coating film is insufficient in solvent resistance, and when it exceeds 80% by mass, it is not preferable. Is unfavorable because of lowering.
[0022]
The component (C) of the stain-resistant paint composition used as an overclear coat paint in the paint finishing method of the present invention floats on the surface of the paint film and forms a concentrated layer. An organosilicate represented by the general formula (2) and / or a condensate thereof is used to develop stain resistance. Preferable specific examples of the organosilicate represented by the general formula (2) and / or the condensate thereof include the same as the organosilicate represented by the general formula (1) and / or the condensate thereof.
In the stain-resistant coating composition used in the present invention, the content of the organosilicate of component (C) and / or the condensate thereof is 0.1 to the total non-volatile content of components (A) to (C). 30 mass% is preferable, 0.2-25 mass% is more preferable, 0.5-20 mass% is especially preferable. When the component (C) is less than 0.1% by mass, the saturated water contact angle at which the cured coating film is formed does not decrease until the desired antifouling performance is satisfied, and when it exceeds 30% by mass, it is cured. Since the water resistance of a coating film falls, it is not preferable.
[0023]
  The stain-resistant coating composition used as an overclear coat coating in the paint finishing method of the present invention is (D)Aliphatic sulfonic acid compound or amine salt of aliphatic sulfonic acid compoundAnd / or (E) aminoplast resinContaining. The (D) component aliphatic sulfonic acid compound or the amine salt of the aliphatic sulfonic acid compound is mainly used to accelerate the hydrolysis reaction of the (C) component organosilicate and / or its condensate, By containing the components, high hydrophilicity can be obtained immediately after the formation of the coating film. More specifically, the aliphatic sulfonic acid compound preferably has an alkyl group having 4 to 30 carbon atoms, more preferably has one or more alkyl groups, and has one or two. Is particularly preferred. 8-30 are preferable and, as for the total carbon number of 1 or 2 or more alkyl groups, 10-24 are especially preferable. The alkyl group is preferably saturated, but may have an unsaturated group. Specific examples of the aliphatic sulfonic acid compound include those obtained by ion exchange of an anionic aliphatic surfactant. Examples of the ion exchange method include using an ion exchange resin or adding an inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid to replace the counter cation with a hydrogen atom. Examples of the anionic aliphatic surfactant include:
[0024]
[Formula 4]

[0025]
(However, R⁷Is an alkyl group having 8 to 30 carbon atoms, R⁸Is an alkyl group having 4 to 12 carbon atoms, R⁹Represents an alkyl group having 13 to 30 carbon atoms. ) And the like.
The aliphatic sulfonic acid compound obtained by the above method may be used as it is or in the form of an amine salt. Examples of the amine salt include a salt obtained by neutralizing the aliphatic sulfonic acid compound obtained by the above method with an amine. Specific examples of the amine salt of the aliphatic sulfonic acid compound include, for example, methylamine, ethylamine, propylamine, isopropylamine, butylamine, hexylamine, octylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dihexylamine, Dioctylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, dimethylethanolamine, methyldiethanolamine, pyridine, morpholine, N-methylmorpholine Aniline, dimethylaniline, dimethylbenzylamine, tetramethylbutanediamine, dimethyl Such as Le lauryl amine.
Here, the content of the aliphatic sulfonic acid compound of the component (D) or the amine salt of the aliphatic sulfonic acid compound is 0 to 10% by mass with respect to the total nonvolatile content of the components (A) to (C). Preferably, 0.1-5 mass% is more preferable, and 0.2-3 mass% is especially preferable. When the content of the aliphatic sulfonic acid compound (D) or the amine salt of the aliphatic sulfonic acid compound exceeds 10% by mass, the water resistance of the cured coating film is lowered, which is not preferable.
[0026]
  Furthermore, the stain-resistant coating composition used as an overclear coat coating in the paint finishing method of the present invention is:,(E) An aminoplast resin can also be contained as a component. The aminoplast resin as the component (E) can react with the transparent primer in the lower layer, and high adhesion can be obtained by the inclusion of the component. As such aminoplast resin, for example, melamine resin, urea resin, guanamine resin, glycoluril resin and the like can be used, and melamine resin is particularly preferable from the viewpoint of weather resistance.
  Here, the content of the aminoplast resin as the component (E) is preferably 0 to 30% by mass, more preferably 1 to 25% by mass, with respect to the total non-volatile content of the components (A) to (C). 2-20 mass% is especially preferable. When the content of the (E) component aminoplast resin exceeds 30% by mass, the acid resistance of the cured coating film is lowered, which is not preferable.
[0027]
The stain-resistant coating composition used in the present invention is an organic solvent and / or various additives, for example, an ultraviolet absorber, a light stabilizer, an antioxidant, a surfactant, a surface conditioning, as it is or as necessary. An agent, an antifoaming agent, a curing reaction catalyst, an antistatic agent, a fragrance, a dehydrating agent, and a rheology adjusting agent such as polyethylene wax, polyamide wax, and internally crosslinked resin fine particles can be added and used.
The transparent primer used in the present invention is used for the purpose of improving the adhesion of the over clear coat film without adversely affecting the color of the lower color coat and the appearance of the over clear coat film. The transparent primer is not particularly limited as long as it can achieve the above object, and various transparent primers can be used.
A preferable transparent primer is one containing (a) an acrylic resin having both a hydroxyl group and an epoxy group, (b) an aminoplast resin, and (c) a urethane resin curing agent as essential components.
[0028]
The acrylic resin having both a hydroxyl group and an epoxy group as the component (a) of the transparent primer is preferably a radical polymerizable monomer having a hydroxyl group, a radical polymerizable monomer having an epoxy group, and other radical polymerizable monomers. It can be obtained by subjecting a mixture of monomers to ordinary radical copolymerization in an organic solvent. Since this radical polymerizable monomer mixture is a polymerizable monomer mixture for synthesizing acrylic resins, the acrylic polymerizable monomer is contained in at least 50% by mass, preferably 75% by mass, Preferably it contains 90 mass% or more. Specific examples of the radically polymerizable monomer having a hydroxyl group, the radically polymerizable monomer having an epoxy group, and other radically polymerizable monomers include those described above.
[0029]
Here, the radically polymerizable monomer having a hydroxyl group is preferably used in the range of 1 to 60% by mass in the total monomer constituting the acrylic resin of the component (a), and 5 to 55% by mass. More desirably, 10 to 50% by mass is particularly desirable. When the radically polymerizable monomer is less than 1% by mass, the adhesion of the overclear coat film cannot be improved, and this is not preferable. When it exceeds 60% by mass, the cured coating obtained finally is obtained. This is not preferable because the appearance of the film deteriorates.
Moreover, it is desirable that the radical polymerizable monomer having an epoxy group is used in the range of 1 to 40% by mass in the total monomer constituting the acrylic resin of component (a), and 1.5 to 35% by mass. % Is more desirable, and 2 to 30% by mass is particularly desirable. When the radically polymerizable monomer is less than 1% by mass, it is not preferable because the adhesion of the overclear coat film cannot be improved, and when it exceeds 40% by mass, the cured coating obtained finally is obtained. This is not preferable because the appearance of the film is deteriorated.
[0030]
In a preferred transparent primer, the acrylic resin having both the hydroxyl group and the epoxy group of the component (a) should be used within a range of 40 to 80% by mass with respect to the total non-volatile content of the components (a) to (c). Is desirable, 45-75 mass% is more desirable, 50-70 mass% is especially desirable. Here, when the component (a) is less than 40% by mass or exceeds 80% by mass, it is not preferable because the adhesion of the overclear coat film cannot be improved.
The aminoplast resin as the component (b) and the urethane resin curing agent as the component (c) of the preferred transparent primer are compounds that undergo a thermosetting reaction with the acrylic resin as the component (a).
As the aminoplast resin as the component (b), for example, melamine resin, urea resin, guanamine resin, glycoluril resin and the like can be used, and melamine resin is particularly preferable from the viewpoint of weather resistance. Here, the content of the aminoplast resin as the component (b) is preferably 0 to 60% by mass, more preferably 1 to 55% by mass, based on the total amount of the nonvolatile components of the components (a) to (c). 2-50 mass% is especially preferable. When the content of the component (b) aminoplast resin exceeds 60% by mass, the adhesion of the overclear coat film cannot be improved.
[0031]
The urethane resin curing agent of component (c) is not particularly limited as long as it is a curing agent capable of curing the urethane resin, and is preferably a polyisocyanate compound having two or more isocyanate groups and / or blocked isocyanate groups in one molecule. . Specific examples of the polyisocyanate compound having two or more isocyanate groups in one molecule include, for example, hexanemethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and dicyclohexylmethane-4,4-diisocyanate. And a compound called an isocyanate monomer, polyisocyanate derivatives such as biurets, isocyanurates, adducts with trimethylolpropane, and the like. These polyisocyanate compounds may be used alone or in combination of two or more.
[0032]
Specific examples of the polyblock isocyanate compound include those produced by blocking a part or all of the isocyanate groups of the polyisocyanate compound with a blocking agent. Examples of this blocking agent include ketoxime blocking agents such as ε-caprolactam, methyl ethyl ketoxime, methyl isoamyl ketoxime, methyl isobutyl ketoxime, phenol blocking agents such as phenol, cresol, catechol, nitrophenol, isopropanol , Alcohol blocking agents such as trimethylolpropane, active methylene blocking agents such as malonic acid esters and acetoacetic acid esters, and azole blocking agents such as 3,5-dimethylpyrazole and 1,2,4-triazole Etc. These polyblock isocyanate compounds may be used alone or in combination of two or more.
Here, the content of the urethane resin curing agent of the component (c) is preferably 0 to 60% by mass, and more preferably 1 to 50% by mass with respect to the total amount of non-volatile components of the components (a) to (c). 2 to 40% by mass is particularly preferable. When the content of the urethane resin curing agent as the component (c) exceeds 60% by mass, it is not preferable because the adhesion of the overclear coat film cannot be improved.
[0033]
A preferable transparent primer can also contain internal cross-linked resin fine particles as component (d) as required. The internal cross-linking resin fine particles of the component (d) are used to suppress mixing of the transparent primer and the over clear coat paint when the clear primer is applied and the over clear coat paint is applied in an uncrosslinked state. In addition, high appearance can be obtained by the inclusion of the component.
The internally cross-linked resin fine particles of the component (d) have a polyfunctional radical polymerizable monomer as a cross-linking agent component as an essential component, and if necessary, a radical polymerizable monomer having a hydroxyl group and other radicals. The polymerizable monomer can be obtained by radical homopolymerization or radical copolymerization in a micelle formed by a surfactant. Here, since a polyfunctional radical polymerizable monomer having two or more radical polymerizable double bonds in one molecule is an essential constituent component, the obtained resin fine particles have a cross-linked structure therein. When the internally crosslinked resin fine particles have a hydroxyl group, the hydroxyl group reacts with the (b) component aminoplast resin or the (c) component urethane resin curing agent of the transparent primer, so that the fine particle has a crosslinked structure even outside thereof. Can be formed.
[0034]
Specific examples of such polyfunctional radical polymerizable monomers include, for example, divinylbenzene, diallyl phthalate, diallyl terephthalate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, Triethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene glycol diacrylate Methacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, Opentyl glycol diacrylate, neopentyl glycol dimethacrylate, 2-hydroxy-1,3-diacryloxypropane, 2-hydroxy-1,3-dimethacryloxypropane, 2,2-bis [4- (acryloxyethoxy ) Phenyl] propane, 2,2-bis [4- (methacryloxyethoxy) phenyl] propane, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethane trimethacrylate, pentaerythritol triacrylate , Pentaerythritol trimethacrylate, dipentaerythritol triacrylate, dipentaerythritol trimethacrylate, pentaerythritol tetraacrylate, Intererythritol tetramethacrylate, dipentaerythritol tetraacrylate, dipentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, and among them active hydrogen Examples thereof include urethane acrylate and urethane methacrylate modified with an isocyanate compound, and are used as one kind or a mixture of two or more kinds. Specific examples of the radical polymerizable monomer having a hydroxyl group and other radical polymerizable monomers include the same ones as described above.
[0035]
The internally crosslinked resin fine particles of the component (d) can be obtained by emulsion polymerization using these radical polymerizable monomers in the presence of a surfactant. Here, as the surfactant, for example, an anionic surfactant, a cationic surfactant, a nonionic surfactant, a zwitterionic surfactant, and the like can be used. The internally crosslinked resin fine particles obtained as an aqueous dispersion by an emulsion polymerization method are used after being converted to a non-aqueous dispersion.
The content of the internally cross-linked resin fine particles of the component (d) is preferably 0 to 40% by mass, more preferably 1 to 35% by mass, with respect to the total non-volatile content of the components (a) to (c). 2-30 mass% is especially preferable. When the content of the internally cross-linked resin fine particles of component (d) exceeds 40% by mass, the appearance of the finally obtained cured coating film is deteriorated, which is not preferable.
Furthermore, the preferable transparent primer can also contain a ketone solvent as (e) component as needed. The ketone solvent of the component (e) can dissolve the additive layer formed on the surface of the lower layer coating film, and high adhesion can be obtained by containing the component.
Specific examples of such ketone solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, cyclohexanone, and isophorone. Here, the content of the ketone solvent of the component (e) is preferably 0 to 40% by mass, more preferably 1 to 35% by mass with respect to the total amount of non-volatile components of the components (a) to (c). 2-30 mass% is especially preferable. When the content of the ketone solvent as the component (e) exceeds 40% by mass, the final appearance of the cured coating film is deteriorated, which is not preferable.
[0036]
In addition, the transparent primer used in the present invention is used as it is or as necessary, and an organic solvent and / or various additives, for example, an ultraviolet absorber, a light stabilizer, an antioxidant, a surfactant, a surface conditioner, Anti-foaming agent, curing reaction catalyst, antistatic agent, fragrance, dehydrating agent, silane coupling agent, rheology adjusting agent such as polyethylene wax and polyamide wax, and complementary added resin such as cellulose acetate butyrate Can be used.
[0037]
The colored base coat paint used in the present invention is not particularly limited, and various colored base coat paints such as a solvent type and an aqueous type can be used.
The colored base coat paint contains a resin binder and a pigment. Examples of the resin include various resins such as known acrylic resins, polyester resins (including alkyd resins), polyurethane resins, and melamine resins. One kind of these resins may be used, or two or more kinds thereof may be used in combination. Two or more kinds of resins having two or more reactive functional groups in one molecule are combined to form a curable resin composition. It is preferable. Particularly preferred is a combination of an acrylic resin or polyester resin having a hydroxyl group and a melamine resin.
[0038]
Various pigments are used as the pigment. For example, aluminum, copper, brass, bronze, stainless steel, or mica-like iron oxide, scaly metallic powder, titanium oxide, or iron oxide, each of which has been surface-treated. Metal pigments such as mica pieces coated with, inorganic pigments such as titanium dioxide, iron oxide, yellow iron oxide, carbon black, organic pigments such as phthalocyanine blue, phthalocyanine green, quinacridone red pigment, precipitated barium sulfate, clay, Examples include extender pigments such as silica, talc, kaolin and bentonite. These pigments may be used alone or in combination of two or more. The blending ratio is usually 0.5 to 200 parts by weight with respect to 100 parts by weight of resin solids, preferably 2 ~ 100 parts by weight.
The colored base coat paint used in the present invention is used as it is or as necessary, such as water, an organic solvent and / or various additives such as an ultraviolet absorber, a light stabilizer, an antioxidant, a surfactant, a surface. Modifiers, antifoaming agents, curing reaction catalysts, antistatic agents, fragrances, dehydrating agents, silane coupling agents, rheology modifiers such as polyethylene wax, polyamide wax, internally cross-linked resin fine particles, and cellulose acetate butyrate It is possible to add and use a resin added in a complementary manner.
[0039]
The clear coat paint used in the present invention is not particularly limited, and various clear coat paints can be used. The clear coat paint is a curable resin composition. Examples of the resin include various resins such as known acrylic resins, polyester resins (including alkyd resins), polyurethane resins, and melamine resins. Among these resins, two or more resins having two or more reactive functional groups in one molecule are combined to form a curable resin composition. Particularly preferred is a combination of an acrylic resin having a hydroxyl group and a melamine resin.
The clear coat paint is used as it is or as needed, and an organic solvent and / or various additives, for example, an ultraviolet absorber, a light stabilizer, an antioxidant, a surfactant, a surface conditioner, an antifoaming agent. An agent, a curing reaction catalyst, an antistatic agent, a fragrance, a dehydrating agent, a silane coupling agent, and a rheology adjusting agent such as polyethylene wax, polyamide wax, and internally crosslinked resin fine particles can be added and used. Furthermore, if necessary, the above-mentioned pigment or dye having good weather resistance can be added to such an extent that transparency is not impaired.
[0040]
The colored top coat used in the present invention is not particularly limited, and various colored top coats can be used, and examples thereof include the same colored paint as the colored base coat paint.
The over clear coat paint, transparent primer, colored base coat paint, clear coat paint and colored top coat paint are heated as necessary, or adjusted to a desired viscosity by adding an organic solvent or a reactive diluent. The coating is performed using a commonly used coating machine such as an air spray, electrostatic air spray, roll coater, flow coater, or dipping type coating machine, or a brush, bar coater, applicator, or the like. Of these, spray coating is preferred.
The substrate used in the paint finishing method of the present invention is not particularly limited, and various types of substrates can be used. For example, wood, glass, metal, cloth, plastic, foam, elastic body, Organic materials such as paper, ceramic, concrete, and gypsum board, and inorganic materials can be used. These base materials may have been surface-treated in advance, or may have a coating film formed on the surface in advance.
[0041]
A preferred example of the paint finishing method of the present invention is to apply the colored base coat paint on the substrate so that the film thickness after drying is usually 5 to 40 μm, preferably 7 to 35 μm, It is allowed to stand at room temperature to 100 ° C. for 1 to 20 minutes, and then the clear coat paint is applied using the above method so that the film thickness after drying is usually 10 to 100 μm, preferably 10 to 60 μm. It is heat-cured at a temperature of 300 ° C. for 5 seconds to 24 hours, and the transparent primer is applied using the above method so that the film thickness after drying is usually 1 to 60 μm, preferably 5 to 40 μm, and room temperature to 100 Left at a temperature of 1 ° C. for 1 to 20 minutes, and then the over-clear coat coating is applied using the above method so that the film thickness after drying is usually 1 to 60 μm, preferably 5 to 50 μm, It is heat-cured at a temperature of ˜300 ° C. for 5 seconds to 24 hours.
[0042]
Further, a preferred example of the paint finishing method of the present invention is that the colored top coating material is applied onto the substrate so that the film thickness after drying is usually 5 to 100 μm, preferably 10 to 60 μm. Then, it is heat-cured at a temperature of 60 to 300 ° C. for 5 seconds to 24 hours, and the transparent primer is applied using the above method so that the film thickness after drying is usually 1 to 60 μm, preferably 5 to 40 μm. , Left at room temperature to 100 ° C. for 1 to 20 minutes, and then applied the over clear coat coating using the above method so that the film thickness after drying is usually 1 to 60 μm, preferably 5 to 50 μm, Heat curing is performed at a temperature of 60 to 300 ° C. for 5 seconds to 24 hours.
In addition, before applying the transparent primer, adhere to the surface of the clear coat film or colored top coat film, such as dry wiping with cloth, wiping with cloth containing organic solvent, sanding with sandpaper, etc. You may perform the process which improves.
Examples of the coated article obtained by the paint finishing method of the present invention include structures, wooden products, metal products, plastic products, rubber products, processed paper, ceramic products, and glass products. More specifically, automobiles, automotive parts (for example, parts such as bodies, bumpers, spoilers, mirrors, wheels, interior materials, etc., of various materials), metal plates such as steel plates, motorcycle parts, motorcycle parts , Road materials (eg, guardrails, traffic signs, noise barriers, etc.), tunnel materials (eg, side walls, etc.), ships, railway vehicles, aircraft, furniture, musical instruments, household appliances, building materials, containers, office supplies, Examples include sports equipment and toys.
[0043]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not restrict | limited at all by these Examples. In addition, the performance of the coating film obtained by the coating finishing method of this invention was calculated | required as follows.
(1) Appearance
Evaluation was made according to the following criteria by visual observation.
○: When a fluorescent lamp is projected on the coating film, the fluorescent lamp is clearly reflected.
(Triangle | delta): When a fluorescent lamp is projected on a coating film, the circumference | surroundings (outline) of a fluorescent lamp will be blurred a little.
X: When a fluorescent lamp is projected on the coating film, the periphery (outline) of the fluorescent lamp is significantly blurred.
(2) Water contact angle
The obtained test plate was exposed outdoors for 7 days in accordance with the weather resistance test method of JIS K-5400 (1990) 9.9. Then, after washing the test plate, a 0.8 μl drop of deionized water was placed on the surface of the coating film at 20 ° C. using a syringe, and an Elmagniometer type contact angle measuring device GI type manufactured by Elma Co., Ltd. was used. Measured. The contact angle was measured every 30, 60, and 90 seconds per droplet, and the contact angle was extrapolated from the linear regression equation of time and contact angle to 0 seconds, which was used as the contact angle of the test plate.
[0044]
(3) Outdoor exposure pollution resistance
According to the weather resistance test method of JIS K-5400 (1990) 9.9, after exposure for 3 months outdoors, the color of the unwashed surface of the paint film is changed to that of JIS K-5400 (1990) 7.4.2 paint film. Measured according to color-measurement method, L after exposure^*L when not exposed from the value^*△ L by subtracting the value^*The value was calculated and the stain resistance of the coating film was judged. Where △ L^*The closer the value is to 0, the better the stain resistance.
(4) Decontamination
A decontamination test solution having the composition described below was uniformly applied by spraying to the coating film exposed and washed outdoors under the same conditions as the water contact angle. Next, decontamination was performed by applying flowing water of 7 L / min from an angle of 45 ° to the coating film for 15 seconds. Thereafter, the color of the coating film was measured according to JIS K-5400 (1990) 7.4.2 Color of coating film-measurement method, and L after the contamination was removed.^*L before application of test solution^*△ L by subtracting the value^*The value was calculated and the decontamination property of the coating film was judged. Where △ L^*The closer the value is to 0, the better the decontamination performance.
Decontamination test solution
Kanto Loam (JIS Z-8901 (1995) Test Powder I, 8 types) 0.5 parts by mass
Carbon black (JIS Z-8901 (1995) test powder I, 12 types) 0.5 parts by mass
99.0 parts by mass of deionized water
(5) Weather resistance
After exposure for 3000 hours using a sunshine carbon arc lamp type accelerated weathering tester (JIS K-5400 (1990) 9.8.1), the state of the coating film was visually determined.
(6) Water resistance
The test piece was immersed in warm water at 40 ° C. for 240 hours to visually determine the state of the coating film.
(7) Acid resistance
0.2 ml of 40% by mass sulfuric acid aqueous solution was spotted on the test piece and heated at 60 ° C. for 30 minutes. This test piece was washed with running water, and the abnormality of the coating film was visually determined.
(8) Adhesion
About the coating film after the initial stage and the weather resistance test, an adhesion test was conducted according to the cross-cut tape method of JIS K-5400 (1990) 8.5.2, and the adhesion was evaluated according to the following criteria.
○: 10 points
Δ: 8 points
×: 6 points or less
[0045]
<Production Examples 1 and 2>
Production of Modified Resin Solutions A-1 and A-2 as Component (A) of Overclear Coat Paint
A four-necked flask equipped with a thermometer, reflux condenser, stirrer, and dropping funnel is charged with a mixture of xylene and organosilicate condensate (initial charge) having the composition shown in Table 1 and heated with stirring under a nitrogen stream. 140 ° C was maintained. Next, a mixture of monomer and polymerization initiator having the composition shown in Table 1 (dropping component) was dropped at a constant rate from a dropping funnel over 2 hours at a temperature of 140 ° C. with stirring. After completion of dropping, the reaction temperature was lowered to 110 ° C. after maintaining at a temperature of 140 ° C. for 1 hour. Thereafter, a polymerization initiator solution (additional catalyst) having the composition shown in Table 1 was added to the reaction mixture, and the reaction was terminated when the temperature of 110 ° C. was maintained for 2 hours. Resin solutions A-1 and A-2 were obtained.
[0046]
[Table 1]

The subscript substances in the table are shown below.
1) Product name, Colcoat Co., Ltd., organosilicate condensate
[0047]
<Production Example 3>
Production of curing agent solution B-1 of component (B) of overclear coat paint
A four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel was charged with 134 parts by mass of trimethylolpropane and 425.3 parts by mass of methyl isobutyl ketone and heated to 120 ° C. with stirring. Next, 504 parts by mass of methylhexahydrophthalic anhydride was dropped over 2 hours while maintaining the temperature at 120 ° C. with stirring, and the acid value of the mixture (pyridine / water = 9/1 (weight ratio)) was mixed. The solution which was diluted about 50 mass times with the liquid and heat-treated at 90 ° C. for 30 minutes was titrated with a potassium hydroxide standard solution) until the temperature became 160 or less. A curing agent solution B-1 having a carboxylic acid equivalent of 355 was obtained.
[0048]
<Production Example 4>
Production of curing agent solution B-2 of component (B) of overclear coat paint
A four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel was charged with 84 parts by mass of methyl amyl ketone and heated at 140 ° C. while stirring under a nitrogen stream. Next, a monomer and a polymerization initiator mixture (dropping component) having the following composition were dropped at a constant rate from a dropping funnel over 2 hours at a temperature of 140 ° C. with stirring.
Dropping component
Methacrylic acid 20 parts by weight
35 parts by mass of n-butyl methacrylate
45 parts by mass of n-butyl acrylate
5 parts by mass of t-butylperoxy-2-ethylhexanoate
After completion of the dropping, the mixture was kept at a temperature of 140 ° C. for 1 hour, and then the reaction temperature was lowered to 110 ° C. Thereafter, 1 part by mass of t-butylperoxy-2-ethylhexanoate and 10 parts by mass of methyl amyl ketone were added to the reaction mixture, and the reaction was terminated at a temperature of 110 ° C. for 2 hours. 25 ° C.) A curing agent solution B-2 having R to S, a nonvolatile content of 50.4% by mass, and a carboxylic acid equivalent of 860 as a solution was obtained.
[0049]
<Production Example 5>
Production of amine salt solution D-1 of aliphatic sulfonic acid compound as component (D) of overclear coat paint
A mixture having the composition described below was placed in a three-necked flask equipped with a stirrer, and 104.3 parts by mass of 35% by mass hydrochloric acid was added with stirring at room temperature to remove sodium. At this time, the ion exchange reaction proceeded immediately after the addition of hydrochloric acid, and 58.5 parts of NaCl precipitated. After the precipitated NaCl was separated by suction filtration, 101 parts by mass of N-methylmorpholine was added to the filtrate, and the active ingredient concentration blocked as an equimolar amount of N-methylmorpholine (as an aliphatic sulfonic acid compound) was 25% by mass. An amine salt solution D-1 of an aliphatic sulfonic acid compound was obtained.
Lapisol B90²⁾    493.3 parts by mass
n-Butanol 1135.9 parts by mass
The subscript substances are as follows.
2) Product name, manufactured by NOF Corporation, sodium dioctylsulfosuccinate (effective content: 90% by mass)
[0050]
<Production Example 6-8>
Manufacture of over clear coat paint OC-1 ~ 3
  Raw materials having the composition shown in Table 2 were mixed to prepare an overclear coat paint.
[Table 2]

[0051]
The subscript substances in the table are shown below.
3) Product name, manufactured by Mitsubishi Chemical Corporation, organosilicate condensate
4) Product name, manufactured by Tama Chemical Industry Co., Ltd., organosilicate condensate
5) Product name, manufactured by Mitsui Chemicals, Inc., melamine resin solution (nonvolatile content 60 mass%)
6) 10% by mass isobutyl acetate solution of tetra n-butylammonium bromide 7) 20% by mass xylene solution of Tinuvin 900 (trade name, manufactured by Ciba Specialty Chemicals)
8) 20% by mass xylene solution of Tinuvin 292 (trade name, manufactured by Ciba Specialty Chemicals)
9) 10% by mass xylene solution of BYK-300 (trade name, manufactured by Big Chemie)
10) Trade name, manufactured by Esso, aromatic petroleum naphtha
[0052]
<Production example9,10>
Production of acrylic resin solutions a-1 and a-2 as component (a) of the transparent primer
  A four-necked flask equipped with a thermometer, reflux condenser, stirrer, and dropping funnel was charged with a mixture of solvents having the composition shown in Table 3 (initial charge), and heated with stirring under a nitrogen stream to maintain 140 ° C. . Next, the mixture (dropping component) of the monomer and the polymerization initiator having the composition shown in Table 3 was dropped at a constant rate from the dropping funnel over 2 hours at a temperature of 140 ° C. with stirring. After completion of the dropping, the mixture was kept at a temperature of 140 ° C. for 1 hour, and then the reaction temperature was lowered to 110 ° C. Thereafter, a polymerization initiator solution (additional catalyst) having the composition shown in Table 3 was added to the reaction mixture, and the reaction was terminated when the temperature of 110 ° C. was maintained for 2 hours. Finally, xylene (diluting solvent) shown in Table 3 was added to obtain acrylic resin solutions a-1 and a-2 having non-volatile contents shown in Table 3.
[0053]
[Table 3]

The subscript substances in the table are shown below.
11) Trade name, manufactured by Daicel Chemical Industries, Ltd., ε-caprolactone 2 mol-modified 2-hydroxyethyl methacrylate
[0054]
<Production example11>
Production of Internal Crosslinked Resin Fine Particle Dispersion d-1 as Component (d) of Transparent Primer
  In a five-necked flask equipped with a thermometer, reflux condenser, stirrer, and two dropping funnels, 76.2 parts by mass of ion-exchanged water and Lapisol B90 (trade name, manufactured by NOF Corporation, sodium dioctylsulfosuccinate, effective Min. 90% by mass) 1.8 parts by mass were charged and heated with stirring under a nitrogen stream to maintain 80 ° C. After Lapisol B90 is completely dissolved, 1.2 parts by weight of an aqueous solution containing 2% by weight of potassium persulfate is added to the charged mixture, and after 5 minutes, a core part having a composition described below at a temperature of 80 ° C. The body mixture (Drip Component 1) was dropped at a constant rate from the dropping funnel over 1.5 hours. After completion of the dropping, the mixture B was kept at a temperature of 80 ° C. for 30 minutes, and then a shell part monomer mixture having the composition described below (dropping component 2) was dropped at a temperature of 80 ° C. over 1.5 hours. It dropped at a constant speed from the funnel. Meanwhile, at the same time, from 1 hour after the start of dropping of the core part monomer mixture (dropping component 1), 1.2 parts by weight of an aqueous solution containing 2% by weight of potassium persulfate was added from another dropping funnel over 2.5 hours. It was dropped at a constant speed.
[0055]
Dropping component 1
Ethyl acrylate 6.0 parts by mass
Ethylene glycol dimethacrylate 2.3 parts by mass
1.7 parts by weight of divinylbenzene
Ingredient 2
4.1 parts by mass of ethyl acrylate
2-hydroxypropyl methacrylate 2.6 parts by mass
Ethylene glycol dimethacrylate 3.3 parts by mass
[0056]
After completion of the dropwise addition of the monomer mixture and aqueous potassium persulfate solution, the mixture was stirred at 80 ° C. for 2 hours under a nitrogen stream to obtain an internally crosslinked resin fine particle aqueous dispersion. After cooling, 2 parts by mass of toluene, 38 parts by mass of n-butanol and 10 parts by mass of isopropanol were added in order to the internally cross-linked resin fine particle aqueous dispersion, and 2.2 parts by mass of 26% by mass sodium hydroxide was further added. Reflux was performed for 2 hours. Subsequently, after adding 0.9 mass part of 76 mass% formic acid aqueous solution and stirring for 30 minutes, 5 mass parts of isopropanol was added, it was left to stand for 30 minutes, and the isolate | separated water layer was removed. Next, after adding 40 parts by mass of ion-exchanged water to the remaining organic layer and stirring for 30 minutes, 5 parts by mass of isopropanol was added and left for 30 minutes to remove the separated aqueous layer again. After performing this operation again, 40 parts by mass of the acrylic resin solution a-2 and 49 parts by mass of methyl isobutyl ketone were added and subjected to azeotropic dehydration, and after removing only the aqueous layer until the boiling point became 105 ° C. or higher, The solvent was distilled off under reduced pressure until the content reached 30% by mass to obtain an internally crosslinked resin fine particle dispersion d-1.
[0057]
<Production example12~15>
Production of transparent primers PR-1 to PR-4
  Raw materials having the composition described in Table 4 were mixed to prepare a transparent primer.
[Table 4]

[0058]
The subscript substances in the table are shown below.
12) Product name, manufactured by Mitsui Chemicals, melamine resin solution (non-volatile content: 60% by mass)
13) Product name, manufactured by Mitsui Chemicals, Ltd., melamine resin solution (nonvolatile content: 60% by mass)
14) Product name, manufactured by Sumitomo Bayer Urethane Co., Ltd., polyblock isocyanate compound solution (nonvolatile content: 75% by mass)
15) Product name, manufactured by Sumitomo Bayer Urethane Co., Ltd., polyblock isocyanate compound solution (nonvolatile content: 65% by mass)
16) 10% by mass xylene solution of dibutyltin dilaurate
17) 20% by mass xylene solution of Tinuvin 900 (trade name, manufactured by Ciba Specialty Chemicals)
18) 20% by mass xylene solution of Tinuvin 292 (trade name, manufactured by Ciba Specialty Chemicals)
19) 10% by mass xylene solution of BYK-300 (trade name, manufactured by Big Chemie)
[0059]
<Example1~3>
Preparation of test pieces on solvent-based colored base coat paint / clear paint and examination of coating film performance
  Cation electrodeposition paint Aqua No. 4200 (trade name, manufactured by NOF Corporation) was electrodeposited to a dry film thickness of 20 μm, baked at 175 ° C. for 25 minutes, and then an intermediate coating HS-H300 (trade name, manufactured by NOF Corporation) Was sprayed with air to a dry film thickness of 30 μm and baked at 140 ° C. for 30 minutes. Next, a solvent-based colored base coat paint Bellcoat No. 6000 (trade name, manufactured by Nippon Oil & Fats Co., Ltd., paint color: white) was air spray coated to a dry film thickness of 15 μm and set at 20 ° C. for 3 minutes. 6100 (trade name, manufactured by Nippon Oil & Fats Co., Ltd.) was air-sprayed by a wet-on-wet method to a dry film thickness of 40 μm and baked at 140 ° C. for 30 minutes. Next, about Example 1 and 4, it wiped with the cloth which contained acetone with respect to the obtained coating-film surface, respectively. Thereafter, the transparent primer PR-2 to 4 was coated with thinner (Solvesso 100 (trade name, manufactured by Esso, aromatic petroleum naphtha) / butyl acetate = 5/5 (mass ratio)) (Ford Cup No. 4, After being diluted at 20 ° C. for 12 seconds and air-sprayed to a dry film thickness of 10 μm and set at 20 ° C. for 3 minutes, the over-clear coat coating OC-1 to OC-3 is further thinner (Solvesso 100 (trade name) , Manufactured by Esso, Aromatic Petroleum Naphtha)) and sprayed with a coating viscosity (Ford Cup No. 4, 25 seconds at 20 ° C.) by air spray coating to a dry film thickness of 40 μm using a wet-on-wet method. The test piece was then baked at 140 ° C. for 30 minutes. However, in any of Examples 1 to 3, the water- and acid-resistant test plates were black in the base coat paint color. The coating performance is shown in Table 5. In each case, a uniform and glossy coating can be obtained. Excellent appearance, hydrophilicity, resistance to outdoor exposure contamination, decontamination, weather resistance, water resistance, acid resistance And adhesion.
[0060]
[Table 5]

[0061]
<Example4,5>
Preparation of test pieces on water-based colored base coat paint / clear paint and examination of coating film performance
  Cation electrodeposition paint Aqua No. 4200 (trade name, manufactured by NOF Corporation) was electrodeposited to a dry film thickness of 20 μm, baked at 175 ° C. for 25 minutes, and then an intermediate coating HS-H300 (trade name, manufactured by NOF Corporation) Was sprayed with air to a dry film thickness of 30 μm and baked at 140 ° C. for 30 minutes. Next, water-based colored base coat paint Aqua BC-3 (trade name, manufactured by Nippon Oil & Fats Co., Ltd., paint color: white) is applied by air spraying to a dry film thickness of 15 μm, set at 20 ° C. for 3 minutes, and then set at 80 ° C. for 10 minutes. Flush for minutes. After the test piece was allowed to cool to room temperature, the clear coat paint Bellcoat No. 6100 (trade name, manufactured by Nippon Oil & Fats Co., Ltd.) was air spray coated to a dry film thickness of 40 μm and baked at 140 ° C. for 30 minutes. Next, the example5As for, the obtained coating film surface was wiped with a cloth containing acetone. Thereafter, the transparent primers PR-2 and 3 were coated with thinner (Solvesso 100 (trade name, manufactured by Esso, aromatic petroleum naphtha) / butyl acetate = 5/5 (mass ratio)) (Ford Cup No. 4, After being diluted at 20 ° C. for 12 seconds), each was sprayed with air to a dry film thickness of 10 μm and set at 20 ° C. for 3 minutes.2as well as3Is diluted with paint thinner (Solvesso 100 (trade name, manufactured by Esso, Aromatic Petroleum Naphtha)) to a coating viscosity (Ford Cup No. 4, 25 seconds at 20 ° C.), and then dried by a wet-on-wet method. A test piece was prepared by air spray coating to a thickness of 40 μm and baking at 140 ° C. for 30 minutes. However, the example4as well as5In any of the cases, the base coat paint was black in the water-resistant and acid-resistant test plates. The coating performance is shown in Table 6. In each case, a uniform and glossy coating is obtained, and excellent appearance, hydrophilicity, resistance to outdoor exposure contamination, decontamination, weather resistance, water resistance, acid resistance And adhesion.
[0062]
[Table 6]

[0063]
<Example6>
Preparation of test piece on colored top coating and examination of coating film performance
  Cation electrodeposition paint Aqua No. 4200 (trade name, manufactured by NOF Corporation) was electrodeposited to a dry film thickness of 20 μm, baked at 175 ° C. for 25 minutes, and then an intermediate coating HS-H300 (trade name, manufactured by NOF Corporation) Was sprayed with air to a dry film thickness of 30 μm and baked at 140 ° C. for 30 minutes. Next, colored top coat melami No. 2000 (trade name, manufactured by Nippon Oil & Fats Co., Ltd., paint color: white) was air spray coated to a dry film thickness of 40 μm and baked at 140 ° C. for 30 minutes. Next, about Example 7, it wiped with the cloth which contained acetone with respect to the obtained coating-film surface. Thereafter, the transparent primers PR-1 and 4 were coated with thinner (Solvesso 100 (trade name, manufactured by Esso, aromatic petroleum naphtha) / butyl acetate = 5/5 (mass ratio)) (Ford Cup No. 4, Air-diluted coatings diluted to 20 μm at 20 ° C. to a dry film thickness of 10 μm were respectively set at 20 ° C. for 3 minutes, and then the over-clear coat coating OC-1 was thinner (Solvesso 100 (trade name, Esso). Aromatic petroleum naphtha))) is diluted with coating viscosity (Ford Cup No. 4, 25 seconds at 20 ° C.) by air spray coating to a dry film thickness of 40 μm using a wet-on-wet method. A test piece was prepared by baking at 140 ° C. for 30 minutes. The coating performance is shown in Table 7. In each case, a uniform and glossy coating is obtained, and it has excellent appearance, hydrophilicity, resistance to outdoor exposure contamination, decontamination, weather resistance, and adhesion. It was.
[0064]
[Table 7]

[0065]
<Comparative Production Example 1>
Production of acrylic resin solution A-3 as component (A) of the overcoat coating for comparison Construction
In a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel, 75 parts by mass of xylene was charged and heated with stirring in a nitrogen stream to maintain 140 ° C. Next, the mixture (dropping component) of the monomer and the polymerization initiator having the composition described below was dropped at a constant rate from the dropping funnel over 2 hours at a temperature of 140 ° C. with stirring.
Dropping component
18 parts by mass of glycidyl methacrylate
18 parts by mass of n-butyl acrylate
25 parts by mass of methyl methacrylate
2-hydroxyethyl methacrylate 4 parts by mass
20 parts by mass of 2-methoxyethyl acrylate
2 parts by weight of t-butylperoxy-2-ethylhexanoate
After completion of the dropwise addition, the reaction mixture was maintained at a temperature of 140 ° C. for 1 hour, and then the reaction temperature was lowered to 110 ° C. Thereafter, 0.2 parts by mass of t-butylperoxy-2-ethylhexanoate and 4.5 parts by mass of xylene were added to the reaction mixture, and the reaction was terminated at a temperature of 110 ° C. for 2 hours. An acrylic resin solution A-3 having a nonvolatile content of 51.3% by mass was obtained.
[0066]
Production of comparative overcoat coatings OC-4 and 5
  The raw materials having the compositions shown in Table 8 were mixed to prepare a comparative overclear coat paint.
[Table 8]

[0067]
The subscript substances in the table are shown below.
20) Product name, manufactured by Tama Chemical Industry Co., Ltd., organosilicate condensate
21) Product name, manufactured by Mitsui Chemicals, Inc., melamine resin solution (non-volatile content: 60% by mass)
22) 10% by mass isobutyl acetate solution of tetra n-butylammonium bromide
23) 20% by mass xylene solution of Tinuvin 900 (trade name, manufactured by Ciba Specialty Chemicals)
24) 20% by mass xylene solution of Tinuvin 292 (trade name, manufactured by Ciba Specialty Chemicals)
25) BYK-300 (trade name, manufactured by Big Chemie) 10 mass% xylene solution 26) Trade name, manufactured by Esso, aromatic petroleum naphtha
[0068]
<Comparative Examples 1-4>
Preparation of test pieces on solvent-based colored base coat paint / clear paint and examination of coating film performance
Cation electrodeposition paint Aqua No. 4200 (trade name, manufactured by NOF Corporation) was electrodeposited to a dry film thickness of 20 μm, baked at 175 ° C. for 25 minutes, and then an intermediate coating HS-H300 (trade name, manufactured by NOF Corporation) Was sprayed with air to a dry film thickness of 30 μm and baked at 140 ° C. for 30 minutes. Next, a solvent-based colored base coat paint Bellcoat No. 6000 (trade name, manufactured by Nippon Oil & Fats Co., Ltd., paint color: white) was air spray coated to a dry film thickness of 15 μm and set at 20 ° C. for 3 minutes. 6100 (trade name, manufactured by Nippon Oil & Fats Co., Ltd.) was air-sprayed by a wet-on-wet method to a dry film thickness of 40 μm and baked at 140 ° C. for 30 minutes. Next, about Comparative Examples 2-4, it wiped with the cloth which contained acetone with respect to the obtained coating-film surface, respectively. Thereafter, for Comparative Examples 2 and 3, the transparent primer PR-2 was coated with thinner (Solvesso 100 (trade name, manufactured by Esso, aromatic petroleum naphtha) / butyl acetate = 5/5 (mass ratio)). Ford Cup No. 4, diluted at 20 ° C. for 12 seconds) is air sprayed to a dry film thickness of 10 μm and set at 20 ° C. for 3 minutes. Further, the over-clear coat coatings OC-5 and 6 are thinner. (Solvesso 100 (trade name, manufactured by Esso, Aromatic Petroleum Naphtha)) diluted with coating viscosity (Ford Cup No. 4, 25 seconds at 20 ° C.) with a dry film thickness of 40 μm using a wet-on-wet method. The test piece was made by air spray coating and baking at 140 ° C. for 30 minutes. For Comparative Example 4, without applying a transparent primer, the over-clear coat paint OC-4 was coated with thinner (Solvesso 100 (trade name, manufactured by Esso, aromatic petroleum naphtha)) with a coating viscosity (Ford Cup No. .4, 25 seconds at 20 ° C.) was air sprayed to a dry film thickness of 40 μm and baked at 140 ° C. for 30 minutes to prepare test pieces. However, in all cases of Comparative Examples 1 to 4, only the water-resistant test plate was black in the base coat paint color.
[0069]
The coating film performance is shown in Table 9. First, in Comparative Example 1, since no over clear coat paint was applied, it was not hydrophilic and was poor in outdoor exposure contamination resistance and decontamination property. In Comparative Example 2, since the component (A) of the overclear coat paint was not modified at all, the weather resistance and water resistance were poor. Moreover, in Comparative Example 3, since no organosilicate of component (C) and / or its condensate is added to the overclear coat paint, it does not become hydrophilic and is resistant to outdoor exposure contamination and decontamination. inferior. Furthermore, in Comparative Example 4, since no transparent primer was applied, the adhesion was inferior.
[0070]
[Table 9]

[0071]
【The invention's effect】
The paint finishing method of the present invention provides a coating film excellent in stain resistance, decontamination property, weather resistance, water resistance, chemical resistance, appearance and adhesion. Moreover, the coated article of the present invention is an article coated by the coating finishing method, and is excellent in the coating film performance.

Claims (7)

A colored base coat paint is applied on the base material, a clear coat paint is applied in an uncrosslinked state, baked, and then a transparent primer is applied, and an over clear coat paint is applied in an uncrosslinked state and baked. In the paint finishing method, the over clear coat paint is represented by (A) general formula (1)
_{^{(R 1) m -Si- (OR}} 2) 4-m (1)
(In the formula, R ¹ and R ² are each a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group, which may be the same or different, and m is 0 or 1.) Polymerization of a polymerizable monomer mixture for acrylic resin synthesis containing both a radical polymerizable monomer having a hydroxyl group and a radical polymerizable monomer having an epoxy group in the presence of a silicate and / or its condensate (B) a compound having at least one functional group selected from a carboxyl group blocked with a carboxyl group, a carboxylic acid anhydride group and an alkyl vinyl ether compound, and (C) the general formula (2) )
_{^{(R 3) n -Si- (OR}} 4) 4-n (2)
(Wherein R ³ and R ⁴ are each a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group, which may be the same or different, and n is 0 or 1). An antifouling paint composition comprising silicate and / or a condensate thereof as an essential component and further containing (D) an aliphatic sulfonic acid compound or an amine salt of an aliphatic sulfonic acid compound and / or (E) an aminoplast resin. Paint finish method characterized by being a thing. In the paint finishing method in which a colored top coat is applied and baked on a substrate, then a transparent primer is applied, and an over clear coat paint is applied and baked in an uncrosslinked state, the over clear coat paint is (A) general Formula (1)
_{^{(R 1) m -Si- (OR}} 2) 4-m (1)
(In the formula, R ¹ and R ² are each a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group, which may be the same or different, and m is 0 or 1.) Polymerization of a polymerizable monomer mixture for acrylic resin synthesis containing both a radical polymerizable monomer having a hydroxyl group and a radical polymerizable monomer having an epoxy group in the presence of a silicate and / or its condensate (B) a compound having at least one functional group selected from a carboxyl group blocked with a carboxyl group, a carboxylic acid anhydride group and an alkyl vinyl ether compound, and (C) the general formula (2) )
_{^{(R 3) n -Si- (OR}} 4) 4-n (2)
(Wherein R ³ and R ⁴ are each a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group, which may be the same or different, and n is 0 or 1). An antifouling paint composition comprising silicate and / or a condensate thereof as an essential component and further containing (D) an aliphatic sulfonic acid compound or an amine salt of an aliphatic sulfonic acid compound and / or (E) an aminoplast resin. Paint finish method characterized by being a thing. The over-clear coat coating contains 3 to 80% by mass of component (A), 3 to 80% by mass of component (B), and 0.1 to 30% by mass of component (C) in a nonvolatile content ratio. The paint finishing method according to any one of claims 1 and 2. At least one of the side chains of the modified resin of the component (A) of the overclear coat paint is represented by the general formula (3)

(Wherein R ⁵ and R ⁶ are each a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and y is an integer of 1 to 10). Item 4. The paint finishing method according to any one of Items 1, 2, and 3. The transparent primer comprises (a) an acrylic resin having both a hydroxyl group and an epoxy group, (b) an aminoplast resin, and (c) a urethane resin curing agent as essential components, and (d) an internally crosslinked resin fine particle and 5. The paint finishing method according to claim 1, further comprising (e) a ketone solvent. The transparent primer contains (a) component at a nonvolatile content ratio of 40 to 80% by mass, (b) component at 0 to 60% by mass, and (c) component at a ratio of 0 to 60% by mass. Item 6. The paint finishing method according to Item 5. A coated article characterized by being coated by the coating finishing method according to any one of claims 1 to 6.