JP3873315B2 - Forming method of coating film - Google Patents

Description

【００８１】
［ただし、式中のＲ¹ は炭素数が１〜１８なるアルキル基を、あるいはフェニル基、アリール基またはアラルキル基を表わすものとし、また、Ｒ² およびＲ³ は、それぞれ、同一であっても異なっていてもよい、水素原子もしくははハロゲン原子を、またはアルキル基、シクロアルキル基、アルコキシル基、シクロアルコキシ基、アリール基、アリールオキシ基、アルカノイルオキシ基、アラルキル基、アラルキルオキシ基、ニトリル基およびハロゲン原子よりなる群から選ばれる、少なくとも１種の原子団で以て置換されていても置換されていなくてもよい、炭素数が１〜１８なるアルキル基を、あるいはアリール基、シクロアルキル基、アラルキル基、アルカノイル基、アルコキシル基、アリールオキシ基、シクロアルコキシ基、アラルキルオキシ基またはアルカノイルオキシ
基を表わすものとする。］
【００８２】
かかるシロキシ基として特に代表的なるもののみを例示するにとどめれば、トリメチルシロキシ基、トリエチルシロキシ基、トリフェニルシロキシ基、ジメチルエトキシシロキシ基またはトリエトキシシロキシ基などであるが、就中、トリアルキルシロキシ基またはトリアルコキシシロキシ基が、好ましい構造のものであると言える。
【００８３】
当該ビニル系重合体（Ｆ）を得るには、たとえば、▲１▼ 前掲したようなシロキシ基を有するビニル系単量体を、単独で以て重合せしめるか、または該シロキシ基含有ビニル系単量体と、該単量体と共重合可能なる其の他の単量体類とを共重合せしめるとか、あるいは▲２▼ 予め調製しておいた水酸基含有ビニル系重合体類に、クロロシランなどのような、いわゆるシリル化剤と反応せしめるとか、さらには、▲３▼ アルコキシシラン類と、水酸基とのアルコール交換反応などのような方法によればよく、このようにして、当該シロキシ基含有ビニル系重合体（Ｆ）を調製することが出来るが、その調製のし易さからも、▲１▼の方法によるのが望ましい。
【００８４】
上記した▲１▼なる方法によって、当該ビニル系重合体（Ｆ）を調製する際に使用される、シロキシ基含有ビニル系単量体（ｆ−１）として特に代表的なるもののみを例示するにとどめれば、２−トリメチルシロキシエチル（メタ）アクリレート、２−トリメチルシロキシプロピル（メタ）アクリレート、４−トリメチルシロキシブチル（メタ）アクリレート、２−トリエチルシロキシエチル（メタ）アクリレート、３−トリブチルシロキシプロピル（メタ）アクリレート、２−トリメチルシロキシエチルビニルエーテル、４−トリメチルシロキシブチルビニルエーテルまたは２−トリメチルシロキシエチル−アリルエーテルなどである。
【００８５】
かかるシロキシ基含有単量体（ｆ−１）は、単独使用でも、あるいは此の単量体（ｆ−１）の２種以上の併用でもよいことは、勿論である。
【００８６】
此のシロキシ基含有ビニル系単量体（ｆ−１）と共重合可能なる其の他の単量体類（ｆ−２）としては、前掲した、それぞれ、水酸基含有ビニル系単量体（ａ−１）、不飽和カルボン酸（ａ−３）またはビニル系単量体（ａ−４）などのような種々の単量体の中から、適宜、選択して使用するというようにすればよい。
【００８７】
就中、こうした単量体類（ｆ−２）に関して、上記した、一分子中に少なくとも２個のシロキシ基を有するビニル系重合体（Ｆ）中には、本発明を更に効果あらしめるためにも、すなわち、ポリオレフィン系基材上に、とりわけ、耐酸性、塗膜外観、硬度および耐候性などの塗膜諸性能に優れた塗膜を形成せしめるためにも、炭素原子に結合した加水分解性シリル基（以下加水分解性シリル基）を併存させることが望ましい。
【００８８】
ここにおいて、当該ビニル系重合体（Ｆ）中に、シロキシ基と併存せしめるべき、上記した加水分解性シリル基とは、次に掲げるような一般式［ＩＩ］で以て示される化合物を指称するものである。
【００８９】
【化２】

【００９０】
［ただし、式中のＲ⁴ は水素原子またはアルキル基、アリール基もしくはアラルキル基を、Ｒ⁵ はハロゲン原子または（置換）アルコキシ基、アシロキシ基、フェノキシ基、メルカプト基、アミノ基、イミノオキシ基もしくはアルケニルオキシ基を表わすものとし、また、ａは０あるいは１または２なる整数である
ものとする。］
【００９１】
かかる加水分解性シリル基として特に代表的なるもののみを例示するにとどめれば、ハロシリル基、アルコキシシリル基、アシロキシシリル基、フェノキシシリル基、メルカプトシリル基、アミノシリル基、イミノオキシシリル基またはアルケニルオキシシリル基などであるが、就中、硬化時において、好ましからざる揮発分を生じないという面でも、アルコキシシリル基が、好ましい構造のものであると言える。
【００９２】
当該ビニル系重合体（Ｆ）中に、此の加水分解性シリル基を含有せしめるには、当該ビニル系重合体（Ｆ）を調製する際に使用される、上記いた単量体（ｆ−２）の一部ないしは全部に、加水分解性シリル基含有ビニル系単量体〔ここにおいて、該単量体を、（ｆ−３）とする。〕を用いるというようにすればよい。
【００９３】
かかる加水分解性シリル基含有ビニル系単量体（ｆ−３）として特に代表的なるもののみを例示するにとどめれば、３−（メタ）アクリロイルオキシプロピルトリクロロシラン、２−（メタ）アクリロイルオキシプロピルジクロロシラン、アリルメチルジクロロシラン；３−（メタ）アクリロイルオキシプロピルトリメトキシシラン、３−（メタ）アクリロイルオキシプロピルトリエトキシシラン、３−（メタ）アクリロイルオキシプロピルメチルジメトキシシラン、アリルトリメトキシシラン；ビニルトリフェノキシシラン、ビス（ジメチルアミノ）メチルビニルシランなどであるが、決して、これらの例示例のみに限定されるというものではない。
【００９４】
かかる加水分解性シリル基含有ビニル系単量体（ｆ−３）は、単独使用でも、あるいは２種以上の併用でもよいことは、勿論である。
【００９５】
以上に掲げられたような、各種のビニル系単量体類から、当該ビニル系重合体（Ｆ）を調製するには、公知慣用の種々の方法を適用することが出来るが、就中、ラジカル重合開始剤を用いての溶液重合法、つまり、溶液ラジカル重合法のような方法によるのが、最も簡便である。
【００９６】
当該ビニル系重合体（Ｆ）中に導入されるべきシロキシ基の量としては、硬化性などの面からも、シロキシ基を有する繰り返し単位として、当該重合体（Ｆ）の固形分を基準として、１〜１００重量％なる範囲内が、好ましくは、３〜１００重量％なる範囲内が適切である。
【００９７】
また、当該ビニル系共重合体（Ｆ）が加水分解により水酸基を生成した状態での重合体の数平均分子量としては、１，０００〜５０，０００なる範囲内が適切であるし、一方、同様の状態での重合体の水酸基価としては、２０〜２００なる範囲内が適切である。
【００９８】
これらの範囲内に入らないようなビニル系重合体の場合には、どうしても、硬化性などに劣るようになったり、著しく、保存安定性などが低下するようになるので、いずれの場合も好ましくない。
【００９９】
次いで、前記した、水酸基と反応性を有する硬化剤（Ｇ）としては、分子中に少なくとも２個の水酸基と反応する基（水酸基反応性基）を有する化合物であれば、いずれの化合物をも使用することが出来るが、とりわけ、耐酸性や、取扱いの容易さや、さらには、形成される塗膜の性能の観点より、ポリイソシアネート化合物、カルボン酸無水基含有化合物およびエポキシ化合物からなる群より選ばれる、少なくとも１種の化合物を用いることが望ましい。
【０１００】
当該化合物（Ｇ）のうちにあって、ポリイソシアネート化合物として特に代表的なるもののみを例示するにとどめれば、トリレンジイソシアネートもしくはジフェニルメタンジイソシアネートの如き、各種の芳香族系ジイソシアネート；またはヘキサメチレンジイソシアネートもしくはトリメチルヘキサンジイソシアネートの如き、各種の脂肪族系ジイソシアネート；
【０１０１】
イソホロンジイソシアネート、メチルシクロヘキサン−２，４（２，６）−ジイソシアネート、４，４−メチレンビス（シクロヘキシルイソシアネート）もしくは１，３−（イソシアネートメチル）シクロヘキサンの如き、各種の脂環式系ジイソシアネート；
【０１０２】
上掲したような各種のジイソシアネート類と、エチレングリコール、トリメチロールエタンもしくはトリメチロールプロパンをはじめとする、種々の多価アルコール類や、ポリエチレングリコールもしくはポリプロピレングリコールの如き、各種のポリエーテル・ポリオールや、イソシアネート基と反応する官能基を有するポリカプロラクトン・ポリオールの如き、比較的低分子量のポリエステル樹脂（油変性タイプをも含む。）やアクリル系共重合体などとの付加物；
【０１０３】
あるいは上掲したような各種のジイソシアネート類と、水とを反応せしめて得られる、いわゆるビュレット構造を有するポリイソシアネート類；またはジイソシアネート類を環化重合せしめて得られる、いわゆるイソシアヌレート環含有ポリイソシアネート類などである。
【０１０４】
当該硬化剤（Ｇ）のうちにあって、それぞれ、カルボン酸無水基含有化合物またはエポキシ化合物として特に代表的なるもののみを例示するにとどめれば、ビニル系重合体、ポリエステル系重合体、ポリエーテル系重合体またはエポキシ樹脂などのような、種々の樹脂類をはじめ、さらには、上掲したような種々の重合体類ないしは樹脂類中に、カルボン酸無水基やエポキシ基などの存在する、種々の化合物などである。
【０１０５】
当該硬化剤（Ｇ）のうち、ビニル系重合体として特に代表的なもののみを例示するにとどめれば、アクリル系−、ビニルエステル系−、芳香族ビニル系−、ポリオレフィン系−、クロル化オレフィン系−またはフルオロオレフィン系ビニル系重合体などである。
【０１０６】
かかる当該硬化剤（Ｇ）のうちのビニル系重合体は、カルボン酸無水基やエポキシ基などを有するビニル系単量体を単独重合せしめるか、あるいは前掲したような共重合可能なる其の他の単量体類（ｆ−２）と共重合せしめることによって、簡便に調製することが出来る。
【０１０７】
ここにおいて、当該硬化剤（Ｇ）のうちの此のビニル系重合体を調製する際に使用される、酸無水物基を有するビニル系単量体として特に代表的なもののみを例示するにとどめれば、無水マレイン酸、無水イタコン酸もしくは無水メタクリル酸の如き、各種のカルボン酸無水基含有不飽和単量体などであるし、
【０１０８】
エポキシ基を有するビニル系単量体として特に代表的なもののみを例示するにとどめれば、グリシジル（メタ）アクリレート、アリルグリシジルエーテル、３，４−エポキシシクロヘキシル（メタ）アクリレートまたはビニルグリシジルエーテルの如き、各種のエポキシ基含有不飽和単量体などであるが、勿論、特に、これらの例示例の化合物のみに限定されるものでは、決してない。
【０１０９】
当該硬化剤（Ｇ）のうちの、カルボン酸無水基を有する化合物であって、ビニル系重合体以外のものとして特に代表的なるもののみを例示するにとどめれば、無水グリセロールトリス（トリメリテート）または無水エチレングリコールジ（トリメリテート）で以て代表されるような、種々の多価カルボン酸無水物などである。
【０１１０】
さらに、当該硬化剤（Ｇ）のうちの、エポキシ基を有する化合物であって、ビニル系重合体以外のものとして特に代表的るもののみを例示するにとどめれば、エチレングリコールジグリシジルエーテル、ネオペンチルグリコールジグリシジルエーテル、１，６−ヘキサンジオールジグリシジルエーテルもしくはグリセリントリグリシジルエーテルの如き、各種の多価アルコールの種々のポリグリシジルエーテル類；
【０１１１】
フタル酸のジグリシジルエステル、イソフタル酸のジグリシジルエステルもしくはアジピン酸のジグリシジルエステルの如き、各種の多価カルボン酸の種々のポリグリシジルエステル類；またはビスフェノールＡないしはビスフェノールＦのグリシジルエーテル型エポキシ樹脂、ノボラック型エポキシ樹脂またはヒダントイン環含有エポキシ樹脂；
【０１１２】
「エポリード ＧＴシリーズ」［ダイセル化学工業（株）製品］などで以て代表されるような、一分子中に少なくとも２個の脂環式オキシラン基を有する脂環式エポキシ樹脂；あるいはｐ−オキシ安息香酸のグリシジルエステルエーテルの如き、各種のエポキシ樹脂などのような、いわゆるポリエポキシ化合物などである。
【０１１３】
さらに、本発明に係る塗膜の形成方法を実施するに当たって使用される、前記した解離促進触媒（Ｈ）とは、前述したビニル系重合体（Ｆ）の有するシロキシ基が、水分との反応によって加水分解されて、水酸基が再生されるのを促進するという化合物を指称するものである。それらのうちでも特に代表的なもののみを挙げるにとどめれば、燐酸類、燐酸エステル類、亜燐酸エステル類、不飽和基含有燐酸エステル類をはじめ、
【０１１４】
ｐ−トルエンスルフォン酸またはそのアミン塩；安息香酸、トリクロル酢酸、ナフタリンジスルフォン酸またはそのアミン塩などのような、各種の酸性触媒類；
【０１１５】
テトラメチルアンモニウムフロライド、テトラエチルアンモニウムクロライド、テトラメチルアンモニウムブロマイド、トリメチルベンジルアンモニウムハイドロキサイド、２−ヒドロキシピリジン、トリメチルアンモニウムメトキサイド、フェニルトリメチルアンモニウムクロライド、フェニルトリメチルアンモニウムブロマイド、フェニルトリメチルアンモニウムハイドロキサイド、フェニルトリメチルアンモニウムヨ−ダイド、フェニルトリメチルアンモニウムブロマイド、ホスフォコリンクロライドナトリウム塩をはじめ、
【０１１６】
ステアリルアンモニウムブロマイド、テトラ−ｎ−ブチルアンモニウムハイドロキサイド、テトラ−ｎ−ブチルアンモニウムフォスフェ−ト、テトラ−ｎ−ドデシルアンモニウムトリクロライド、テトラエチルアンモニウムハイドロキサイド、テトラエチルアンモニウムテトラフルオロボレ−ト、アセチルコリンブロマイド、アルキルジメチルベンジルアンモニウムクロライド、ベンジルコリンブロマイド、ベンジル−ｎ−ブチルアンモニウムブロマイド、ベタイン、ブチリルクロライド、ビス（テトラ−ｎ−ブチルアンモニウム）ジクロメ−トもしくはトリメチルビニルアンモニウムブロマイドの如き、各種の４級アンモニウム塩類；
【０１１７】
アリルトリフェニルホスフォニウムクロライド、ｎ−アミルトリフェニルホスフォニウムブロマイド、ベンジルトリフェニルホスフォニウムクロライド、ブロモメチルトリフェニルホスフォニウムブロマイド、２−ジメチルアミノエチルトリフェニルホスフォニウムブロマイド、エトキシカルボニルホスフォニウムブラマイド、ｎ−ヘプチルトリフェニルホスフォニウムブロマイド、メチルトリフェニルホスフォニウムブロマイド、テトラキス（ヒドロキシメチル）ホスフォニウムサルフェートもしくはテトラフェニルホスフォニウムブロマイドの如き、各種のホスフォニウム塩類；
【０１１８】
アルキルチタン酸塩、オクチル酸塩、ジブチル錫ジラウレートまたはオクチル酸鉛の如き、各種のカルボン酸の金属塩類；モノブチル錫サルファイドまたはジオクチル錫メルカプタイドの如き、各種のスルファイド型ないしはメルカプチド型有機化合物類；水酸化リチウムまたは水酸化カリウムの如き、各種のアルカリ性触媒；
【０１１９】
エチレンジアミン、Ｎ−β−アミノエチル−γ−アミノプロピルトリメトキシシラン、ブチルアミン、ジブチルアミン、ｔｅｒｔ−ブチルアミン、ヘキシルアミン、２−エチルヘキシルアミン、トリエチルアミン、ジエタノールアミン、トリエタノールアミンなどのアミン類；
【０１２０】
１，８−ジアザビシクロ（５，４，０）ウンデセン−７もしくは１，４−ジアザビシクロ（２，２，２）オクタンの如き、各種の塩基性触媒類；または炭酸カルシウムの如き、各種の炭酸塩類などである。
【０１２１】
これらの触媒の添加量としては、前述したビニル系重合体（Ｆ）に対して、０．００１〜１０％の範囲内が適切であるし、好ましくは、０．００５〜６％の範囲内が適切である。
【０１２２】
かくして得られる、本発明において使用されるクリヤーコート用塗料の安定性を、さらに一層、向上化せしめるために、いわゆる水結合剤（水分補足剤）を添加することも出来る。
【０１２３】
かかる水結合剤として使用できるもののうちでも、特に代表的なるもののみを例示するにとどめれば、オルト蟻酸トリメチル、オルト蟻酸トリエチルもしくはオルト蟻酸トリブチルの如き、各種のオルト蟻酸トリアルキル類；オルト酢酸トリメチル、オルト酢酸トリエチルもしくはオルト酢酸トリブチルの如き、各種のオルト酢酸トリアルキル類；オルトほう酸トリメチル、オルトほう酸トリエチルもしくはオルトほう酸トリブチルの如き、各種のオルトほう酸トリアルキル類；
【０１２４】
テトラメチルシリケート、テトラエチルシリケート、テトラブチルシリケート、テトラ（２−メトキシエチル）シリケートもしくはテトラ（２−クロロエチル）シリケートの如き、各種のテトラ（置換）アルキルシリケート類単体；テトラフェニルシリケートもしくはテトラベンジルシリケートの如き、上記テトラ（置換）アルキルシリケート類の、各種の同効物質（以下、同効単体と略称する。）；
【０１２５】
あるいはテトラエチルシリケートのダイマー、トリマー、テトラマーないしはヘキサマーなどのような、「エチルシリケート ４０」（アメリカ国コルコート社製の、テトラエチルシリケートのテトラマー、ペンタマーもしくはヘキサマーの混合物の商品名）の如き、各種の、上掲のテトラ（置換）アルキルシリケート類単体や、該シリケート類の同効単体の縮合物などのような、種々の加水分解性エステル化合物類；
【０１２６】
さらには、フェニルイソシアネート、ｐ−クロロフェニルイソシアネート、ベンゼンスルフォニルイソシアネート、ｐ−トルエンスフォニルイソシアネートまたはイソシアネートエチルメタクリレートの如き、各種のイソシアネート基含有化合物類などである。
【０１２７】
上掲したような、種々の水結合剤を添加する場合における、当該水結合剤の使用量としては、当該クリヤーコート用塗料を構成する樹脂固形分の合計量に対して、０．１〜２０重量％なる程度、好ましくは、０．５〜１０重量％なる程度でよい。
【０１２８】
かくして得られる、本発明において使用される当該クリヤーコート用塗料に対しては、必要に応じて、レベリング剤、レオロジー・コントロール剤、光安定剤あるいは紫外線吸収剤などのような、公知慣用の種々の添加剤類をも配合せしめることが可能である。
【０１２９】
また、公知慣用の種々の、それぞれ、セルロース系化合物、可塑剤またはポリエステル樹脂などをも配合せしめることが出来る。
【０１３０】
ポリオレフィン系素材上に、本発明において使用される、それぞれ、下塗り塗料、ベースコート用塗料およびクリヤーコート用塗料を用いて、塗膜を形成する方法としては、通常の方法で以て行なうことが出来る。
【０１３１】
すなわち、ポリオレフィン系素材なるものは、塗装前処理を特に施さない場合もあるが、通常は、プラスチック成形品の表面に付着した機械油や離型剤などの除去、そして、付着性の向上化を目的とした、いわゆる前処理が行なわれる。
【０１３２】
かかる前処理の方法としては、表面の付着剤の除去を目的とした溶剤拭きであるとか、あるいは水系洗浄剤を用いた水系洗浄などのほかにも、トリクロロエタンなどによる蒸気洗浄、火炎処理あるいはプラズマ処理などがある。
【０１３３】
本発明に係る塗膜の形成方法は、下塗り塗料、ベースコート用塗料およびクリヤーコート用塗料を塗装するが、その際の塗装方法としては、スプレー塗装や静電塗装などが好適であり、また、それぞれの塗装間隔は、特に限定されるというものではないけれども、クリヤーコート用塗料を塗装する際は、ベースコート塗料を塗布したのち、此のベースコート用塗料が、指触乾燥ないしは半硬化状態にある時点において行なうのが、特に望ましい。
【０１３４】
それぞれの塗料を塗布したのちのの乾燥条件としては、常温乾燥または加熱乾燥も可能であり、その際の塗装設備ならびに乾燥設備や、それぞれの塗料の種類と、それらの特性となどに応じて、適宜、決定するというようにすればよい。
【０１３５】
かくして、本発明の方法によって形成される、それぞれの塗膜の膜厚は、乾燥膜厚として、下塗り塗料の場合は、５〜１５マイクロ・メーター（μｍ）、ベースコート用塗料の場合は、１５〜３０μｍ、そして、クリヤーコート用塗料の場合は、２０〜６０μｍとなるように調整することが望ましい。
【０１３６】
【実施例】
次に、本発明を、参考例、実施例および比較例により、一層、具体的に説明することにするが、本発明は、決して、これらの例示例のみに限定されるものではない。なお、以下において、部および％は、特に断りの無い限りは、すべて重量基準であるものとする。
【０１３７】
参考例１〔ビニル変性塩素化ポリオレフィン（Ａ）の調製例〕
攪拌機および冷却器を備え付けた反応容器に、「ハードレン １４ＭＬ」［東洋化成工業（株）製の、塩素化ポリプロピレンの商品名；塩素化率＝２６％，固形分（不揮発分）＝３０％］の５００部およびトルエンの８００部を入れ、器内温度を８０℃にまで昇温した。
【０１３８】
そこへ、メチルメタクリレート（ＭＭＡ）の２００部、イソブチルメタクリレート（ＩＢＭＡ）の２００部、エチルアクリレート（ＥＡ）の３００部、２−ヒドロキシエチルメタクリレート（ＨＥＭＡ）の１４０部およびメタクリル酸（ＭＡＡ）の１０部と、ベンゾイルパーオキサイド（ＢＰＯ）の５部およびアゾビスイソブチロニトリル（ＡＩＢＮ）の５部を、酢酸ｎ−ブチルの３５０部に溶解させた溶解物とを、３時間に亘って滴下した。
【０１３９】
以後も、同温に、１２時間のあいだ保持して、重合反応を続行せしめた処、不揮発分が４０．２で、かつ、数平均分子量が２５，０００なる、塩素化ポリプロピレン変性アクリル樹脂たる、ビニル変性塩素化ポリオレフィン（Ａ）の溶液が得られた。以下、これを共重合体（Ａ−１）と略記する。
【０１４０】
参考例２（同上）
参考例１と同様の反応容器に、「ハードレン １４ＭＬ」の６６０部およびトルエンの６８８部を入れ、器内温度を８０℃にまで昇温した。
【０１４１】
そこへ、ＭＭＡの３５０部、シクロヘキシルメタクリレート（ＣＨＭＡ）の１８０部、「プラクセル ＦＭ−１」［ダイセル工業（株）製の、ヒドロキシエチルメタクリレート−ε−カプロラクトン付加物の商品名］の２６２部およびメタクリル酸（ＭＡＡ）の１０部と、ベンゾイルパーオキサイド（ＢＰＯ）の６部およびアゾビスイソブチロニトリル（ＡＩＢＮ）の４部を、ｎ−ブタノールの３５０部に溶解させた溶解物とを、３時間に亘って滴下した。
【０１４２】
以後も、同温に、１２時間のあいだ保持して、重合反応を続行せしめた処、不揮発分が４０．８で、かつ、数平均分子量が２７，０００なる、塩素化ポリプロピレン変性アクリル樹脂たる、ビニル変性塩素化ポリオレフィン（Ａ）の溶液が得られた。以下、これを共重合体（Ａ−２）と略記する。
【０１４３】
参考例例３および４（下塗り塗料の調製例）
それぞれ、共重合体（Ａ−１）または（Ａ−２）の各１１２．５部と、酸化チタンの４０部と、キシレンの２０部とを、各別に、サンドミルで以て、１時間のあいだ練肉せしめることによって、それぞれの白エナメルを得た。
【０１４４】
次いで、これらの各白エナメルに、「スーパーベッカミン Ｌ−１１７−６０」（前出社製のアミノ樹脂の商品名；固形分＝６０％）の２５部と、「ネイキュアー Ｎ−５２２５」［楠本化成（株）製の、ドデシルベンゼンスルフォン酸アミン・ブロック化物の商品名］の１．６部とを加え、しかるのち、トルエン／キシレン／ｎ−ブタノール＝２０／６０／２０（重量部比）なるシンナーで以て、スプレー粘度にまで希釈した。以下、それぞれ、共重合体（Ａ−１）を用いたものを、下塗り塗料（Ｐ−１）と略記し、共重合体（Ａ−２）を用いたものを、下塗り塗料（Ｐ−２）と略記する。
【０１４５】
参考例５（ベースコート用塗料の調製例）
下記するような比率となるように、通常の塗料製造法で以て配合した形の塗料用樹脂組成物を、希釈用溶剤〔キシレン／トルエン／酢酸ｎ−ブチル／メチルエチルケトン＝３０／３０／２０／２０（重量部比）〕により、フォード・カップＮＯ．４で、１１〜１２秒になるような粘度に調整することによって、ベースコート用塗料と為した。以下、このベースコート用塗料を、（ＢＣ−１）と略記する。
【０１４６】
「ベッコライト ＧＦ−５４２」 ７７部
［大日本インキ化学工業（株）製
の水酸基含有ポリエステル樹脂
の商品名；不揮発分＝６５％］
「スーパーベッカミン Ｌ−１１７−６０」 ４２部
（前出社製のｎ−ブチル化メラミ
ン樹脂の商品名；不揮発分＝６
０％）
「ＣＡＢ−３８１−０.５」 ２５部
（アメリカ国イーストマン・コダ
ック社製の、セルロース・アセ
テート・ブチレートの商品名）
「ＥＰＯＬＥＮ Ｎ−１０」 １５部
（同上社製のワックス）
「アルペースト １８６０ＹＬ」 ２３部
［東洋アルミ（株）製の、アルミ
ニウムペーストの商品名；不揮
発分＝６５％］
「ネイキュアー Ｎ−５２２５」 １部
【０１４７】
参考例６（同上）
下記するような比率になるように、通常の塗料製造法で以て配合した形の塗料用樹脂組成物を、希釈用溶剤〔キシレン／トルエン／酢酸ｎ−ブチル／メチルエチルケトン＝３０／３０／２０／２０（重量部比）〕により、フォード・カップＮＯ．４で、１３〜１４秒となるような粘度に調整することによって、ベースコート用塗料と為した。以下、このベースコート用塗料を、（ＢＣ−２）と略記する。
【０１４８】
「アクリディック ４７−７１２」 １６０部
［大日本インキ化学工業（株）製の
水酸基含有アクリル樹脂の商品名
；不揮発分＝５０％］
「スーパーベッカミン Ｌ−１１７−６０」 ３３部
「アルペースト １８６０ＹＬ」 ２３部
「ファーストゲンブルー ＮＫ」 ２部
［大日本インキ化学工業（株）製の
シアニンブルー顔料の商品名］
「ネイキュアー Ｎ−５２２５」 １部
【０１４９】
参考例７（同上）
下記するような比率となるように、通常の塗料製造法で以て配合した形の塗料用樹脂組成物を、希釈用溶剤〔キシレン／トルエン／酢酸ｎ−ブチル／メチルエチルケトン＝３０／３０／２０／２０（重量部比）〕により、フォード・カップＮＯ．４で、１１〜１２秒となるような粘度に調整することによって、ベースコート用塗料と為した。以下、このベースコート用塗料を、（ＢＣ−３）と略記する。
【０１５０】
「アクリディック ４７−５６７」 １００部
［大日本インキ化学工業（株）製
の、水酸基含有アクリル樹脂の
商品名；不揮発分＝５０％］
「バーノック ＤＮ−９５０」 １８部
（同上社製の、ポリイソシアネー
ト化合物の商品名；不揮発分＝
７５％）
「タイペーク ＣＲ−９３」 ６０部
［石原産業（株）製の、酸化チタ
ンの商品名］
【０１５１】
参考例８〔ビニル系重合体（Ｆ）の調製例〕
参考例１と同様の反応容器に、トルエンの５００部および酢酸ｎ−ブチルの５０部を入れ、器内温度を１１０℃にまで昇温した。
【０１５２】
次いで、スチレンの３００部、トリメチルシロキシエチルメタクリレートの２８０部、ＩＢＭＡの２７０部、３−メタアクリロイルオキシプロピルトリメトキシシランの５０部およびラウリルメタクリレートの１００部からなる単量体混合物と、アゾイソブチロニトリル５０部および酢酸ｎ−ブチル４５０部とからなる混合物とを、５時間を要して滴下し、
【０１５３】
さらに、同温度に、１０時間のあいだ保持させることによって、不揮発分が５０％で、数平均分子量が１５，０００で、かつ、シロキシ基より生成するＯＨ価が、不揮発分当たり、８６なる重合体の溶液を得た。以下、このビニル系重合体（Ｆ）の溶液を、（Ｆ−１）と略記する。
【０１５４】
参考例９（同上）
参考例１と同様の反応容器に、トルエンの５００部および酢酸ｎ−ブチルの５０部を入れ、器内温度を１１０℃にまで昇温した。
【０１５５】
次いで、スチレンの２００部、トリメチルシロキシエチルメタクリレートの２３０部、ｎ−ブチルメタクリレートの４００部、ｎ−ブチルアクリレートの１５０部からなる単量体混合物と、アゾイソブチロニトリルの５０部および酢酸ｎ−ブチルの４５０部とからなる混合物とを、５時間を要して滴下した。
【０１５６】
さらに、同温度に、１０時間のあいだ保持させることによって、不揮発分が５０％で、数平均分子量が１６，０００で、かつ、シロキシ基より生成するＯＨ価が、不揮発分当たり、７０なる重合体の溶液を得た。以下、このビニル系重合体（Ｆ）の溶液を、（Ｆ−２）と略記する。
【０１５７】
参考例１０（同上）
参考例１と同様の反応容器に、キシレンの５００部および酢酸ｎ−ブチルの５０部を入れ、器内温度を１１０℃にまで昇温した。
【０１５８】
次いで、スチレンの２００部、「プラクセル ＦＭ−１」（前出社製の商品名で、２−ヒドロキシエチルメタクリレートに、１モルのε−カプロラクトンを付加反応せしめた形の化合物）と、トリメチルクロルシランとの反応生成物の２９０部、ｎ−ブチルメタクリレートの３００部、ｎ−ブチルアクリレートの１５０部およびアクリル酸の４０部からなる単量体混合物と、アゾイソブチロニトリルの５０部および酢酸ｎ−ブチルの５００部とからなる混合物とを、５時間を要して滴下した。
【０１５９】
さらに、同温度に、１０時間のあいだ保持させることによって、不揮発分が５０％で、数平均分子量が１４，０００で、かつ、シロキシ基より生成するＯＨ価が、不揮発分当たり、６６なる重合体の溶液を得た。以下、このビニル系重合体（Ｆ）の溶液を、（Ｆ−３）と略記する。
【０１６０】
参考例１１〔硬化剤（Ｇ）の調製例〕
参考例１と同様の反応容器に、トルエンの５００部、酢酸ｎ−ブチルの５０部および無水マレイン酸１００部を入れ、器内温度を１１０℃にまで昇温した。
【０１６１】
次いで、スチレンの３００部、ｎ−ブチルメタクリレートの３００部、ｎ−ブチルアクリレートの３００部からなる単量体混合物と、アゾイソブチロニトリルの５０部、ｔｅｒｔ−ブチルパーオクトエイト（ｔｅｒｔ−ブチルパーオクテート）の５０部および酢酸ｎ−ブチルの４５０部とからなる混合物とを、５時間を要して滴下した。
【０１６２】
さらに、同温度に、１０時間のあいだ保持させることによって、不揮発分が５０％で、かつ、数平均分子量が５，０００なる重合体の溶液を得た。以下、この溶液を硬化剤（Ｇ−１）と略記する。
【０１６３】
参考例１２〜１５（クリヤーコート用塗料の調製例）
参考例８〜１１で得られた、（Ｆ−１）〜（Ｆ−３）なる、それぞれのビニル系重合体と、硬化剤（Ｇ−１）と、市販のポリイソシアネート化合物と、エポキシ化合物などとを用いて、第１表に示すような配合比率に従って、各別に、配合し、希釈用溶剤〔キシレン／トルエン／酢酸ｎ−ブチル／メチルエチルケトン＝３０／３０／２０／２０（重量部比）〕により、スプレー粘度にまで希釈することによって、各種のクリヤーコート用塗料を得た。
【０１６４】
【表１】

【０１６５】
《第１表の脚註》
（注１） 「ＤＮ−９９０Ｓ」………「バーノック ＤＮ−９９０Ｓ」
［大日本インキ化学工業（株）製の、ポリイソシアネート化合物の商品名；イソシアネート含有量＝１８．０％］の略記
【０１６６】
（注２） ＧＴＧＥ……………………グリセリントリグリシジルエーテルの略記であって、エポキシ当量が１４５なる化合物である。
【０１６７】
（注３） ＴＢＡＣＬ…………………テトラブチルアンモニウムクロライドの略記
【０１６８】
（注４） ＰＴＳＩ……………………ｐ−トルエンスルフォニルイソシアネートの略記
【０１６９】
（注５） 「チヌビン９００」………スイス国チバ・ガイギー（株）製の、紫外線吸収剤の商品名
【０１７０】
（注６） 「サノールＬＳ２９２」…三共（株）製の、光安定剤の商品名
【０１７１】
【表２】

【０１７２】
参考例１６（対照用下塗り塗料の調製例）
共重合体（Ａ−１）の代わりに、「アクリディック Ａ−８０１−Ｐ」［大日本インキ化学工業（株）製の、水酸基含有アクリル樹脂の商品名；不揮発分＝５０％］の９０部を用いるように変更した以外は、参考例３と同様にして、対照用の下塗り塗料を調製した。以下、これを下塗り塗料（ＲＰ−１）と略記する。
【０１７３】
参考例１７（対照用クリヤーコート用塗料の調製例）
次に示すような配合比率に従って配合するというように変更した以外は、参考例１３と同様にして、対照用の、クリヤーコート用塗料を調製した。以下、これをクリヤーコート用塗料（ＲＣ−１）と略記する。
【０１７４】
「アクリディック Ａ−３４５」 １００部
［大日本インキ化学工業（株）
製の水酸基含有アクリル樹脂
の商品名；不揮発分＝５５％］
「スーパーベッカミン Ｌ−１１７−６０」 ４０部
「ネイキュアー Ｎ−５２２５」 １部
「チヌビン ９００」 １部
「サノール ＬＳ２９２」 １部
【０１７５】
実施例１〜４ならびに比較例１および２
各参考例で得られた、下塗り塗料、ベースコート用塗料およびクリヤーコート用塗料ならびに比較対照用としての、従来型技術に基づく塗料を用いての、前処理の施されたポリプロピレン系樹脂の塗装素材上に塗装する際の各種条件の明記と、得られた塗板についての評価判定試験の結果とを、第２表に列挙する。
【０１７６】
ここにおいて、此の第２表に示す、諸性能の評価判定試験の要領は、次の通りである。
【０１７７】
（１） 光沢
スガ試験機（株）製の、デジタル変角光沢計を用いて測定した。
【０１７８】
（２） 鮮映性
スガ試験機（株）製の、ＰＧＤ鮮映性試験機を用いて測定した。
【０１７９】
（３） 耐酸性
５％硫酸水溶液の０．２ミリ・リットルの液滴を、塗面に載せ、７０℃の雰囲気下に、３０分間のあいだ放置したのちの、塗膜外観の劣化状態を、目視により、評価判定した。
【０１８０】
（４） 鉛筆硬度
「ユニ」［三菱鉛筆（株）製の鉛筆の商品名］を使用して、常法により行なった。
【０１８１】
（５） 促進耐候性
デューパネル光コントロール・ウェザーメーターによる、１，０００時間に及ぶ促進曝露試験後の、塗膜の外観を、目視により、評価判定した。
【０１８２】
（６） 耐久付着性
上記した促進耐候性試験後の塗膜に対して、カッター・ナイフで、クロスカットを入れたのちに、いわゆるセロファン・テープ剥離を行ない、塗膜の付着状態を、目視により、評価判定した。
【０１８３】
【表３】

【０１８４】
【表４】

【０１８５】
《第２表の脚註》
表中の記号は、それぞれ、次のような意味を示している。
【０１８６】
◎…非常に良好
○…良 好
△…不 良
×…極めて不良
【０１８７】
【表５】

【０１８８】
【表６】

【０１８９】

【０１９０】
【表８】

【０１９１】
このように、本発明に係る塗膜の形成方法に従う、それぞれ、実施例１〜４による本発明実施品は、従来型技術に従う、それぞれ、比較例１および２と比較することによっても、明かなように、本発明の塗膜形成方法による場合には、とりわけ、耐酸性、硬度ならびに塗膜外観などに優れた塗膜を形成することが出来、したがって、特に、自動車用ならびに建材用などとして用いられるポリオレフィン系素材の用途にとって、極めて実用性の高いものであることが、無理なく、知り得よう。
【０１９２】
【発明の効果】
以上に詳述した通り、本発明に係る塗膜の形成方法に従えば、とりわけ、耐酸性、硬度ならびに塗膜外観などに優れた塗膜を形成することが出来るということであり、したがって、本発明は、極めて実用性の高い、塗膜の形成方法を提供することが出来るものである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel and useful method for forming a coating film. More specifically, in the present invention, a base coat is formed by applying a base coat to a polyolefin base material to form a base coat, and then applying a base coat paint containing a metallic powder and / or a color pigment to the base coat. Then, the present invention relates to a method for forming a coating film on a polyolefin-based substrate, which comprises applying a clear coat paint on the base coat paint.
[0002]
[Prior art]
In recent years, in the automobile industry, weight saving has been achieved as an effective means for improving fuel efficiency in view of resource saving, energy saving, environmental problems, and the like. As one of them, replacing metal materials so far with plastic materials is being actively promoted.
[0003]
Under such circumstances, polyolefin base materials that are inexpensive and excellent in moldability have come to be used mainly for bumpers, but such polyolefin base materials are usually products for automobile cosmetics and protection. Often it is painted to add value.
[0004]
However, paints in the form of conventional alkyd resins, acrylic resins, epoxy resins, and the like are mostly used for various molded products obtained from so-called crystalline polyolefins with low polarity. Therefore, it is known that chlorinated polyolefin having excellent adhesiveness is used for coating on such a polyolefin-based substrate.
[0005]
However, in the case of such a method, in particular, various properties such as hardness, solvent resistance and weather resistance are poor, and as a result, the original functions of cosmetics and protection cannot be given. It is a fatal wound.
[0006]
Further, as a method for improving these various performances, Japanese Patent Publication No. 3-140269 proposes a technique for a resin composition that is cured with a hydroxyl group-containing acrylic-modified chlorinated polyolefin and a polyisocyanate compound. That said, even with such a method, durability adhesion, hardness and solvent resistance are greatly improved, but in the case of being exposed to the outdoors for a long time, it is absolutely necessary. The problem that the coating film deteriorates remained.
[0007]
Therefore, the chlorinated polyolefin itself is used as an undercoat, and the topcoat is divided into a base coat paint and a clear coat paint, respectively, a hydroxyl group-containing alkyd resin, a hydroxyl group-containing acrylic resin, and a melamine resin. Although it is also known that the coating system is a combination with a coating system, a hydroxyl group-containing alkyd resin or a hydroxyl group-containing acrylic resin, and a coating system that is a combination of a polyisocyanate compound and the like. These methods also have drawbacks such as low adhesion over a long period of time, such as interlayer adhesion between the paint film of the undercoat paint and the paint film of the top coat, as well as polyolefin base materials. ,
[0008]
In the case of using a coating system that is a combination of a hydroxyl group-containing alkyd resin, a hydroxyl group-containing acrylic resin, and the like and a polyisocyanate compound as a clear coat coating material, such a coating system is originally a two-part coating. Because it is a mold, it is necessary to pay sufficient attention to pot life.
[0009]
If the pot life is adjusted within a practical range, it becomes difficult to obtain a coating film with high hardness. Therefore, in order to increase this hardness, a hydroxyl group-containing alkyd resin, a hydroxyl group-containing acrylic resin, etc. If the glass transition temperature (Tg) is increased or the amount of hydroxyl groups is increased, the appearance of the coating film will be reduced and the pot life will be shortened. There wasn't.
[0010]
In addition, when a coating system comprising a combination of a hydroxyl group-containing alkyd resin, a hydroxyl group-containing acrylic resin, or the like as described above and a melamine resin is used as the clear coat coating material, such a coating system is a one-component type. However, due to heat shrinkage during curing, it is not always possible to say that the appearance of the coating film is excellent, and because of the poor acid resistance of the melamine resin itself. However, there are still major problems such as deterioration of the coating film due to acid rain during exposure.
[0011]
After all, a method for forming a coating film excellent in various performances such as acid resistance, coating film appearance, hardness and weather resistance is still in practical use for such a polyolefin-based substrate. The fact is that it has not been realized.
[0012]
[Problems to be solved by the invention]
As described above, as long as the conventional technology is followed, the coating film appearance is inevitably excellent, and particularly, the coating film performance such as acid resistance and weather resistance is excellent, and the adhesion to the polyolefin base material is excellent. In particular, it has been difficult to find an extremely practical and novel method for forming a coating film that gives a coating film that is excellent in durability adhesion to the substrate over a long period of time.
[0013]
However, the present inventors, among other things, have excellent coating performance such as appearance, acid resistance and weather resistance, and are excellent in adhesion to polyolefin base materials, and are extremely practical and innovative. In search of a method for forming such a coating film, we have eagerly started research.
[0014]
Therefore, the problem to be solved by the present invention is that it has an excellent coating film appearance, and in particular, is excellent in coating film performance such as acid resistance and weather resistance, and also adheres to a polyolefin-based substrate. It is an object of the present invention to provide a novel method for forming a novel coating film, which is excellent in properties and, in particular, provides a coating film having excellent durability adhesion to the substrate over a long period of time.
[0015]
[Means for Solving the Problems]
Accordingly, the present inventors have focused on the problems to be solved by the invention as described above, and as a result of earnest and examination, as a result of painting a specific undercoat, and then obtaining the undercoat surface thus obtained. In addition, to find out that such a problem can be solved brilliantly by painting a base coat paint and then painting a specific clear coat paint on the base coat paint. At this point, the present invention has been completed.
[0016]
That is, according to the present invention, a base coat is first applied to a polyolefin-based substrate to form a base coat, and then a base coat paint is applied to the surface of the base coat. Respectively, in a method of forming a coating film, comprising: coating and then applying a clearcoat paint over the basecoat paint;
[0017]
As the above-mentioned undercoat paint, a paint containing a hydroxyl group-containing acrylic-modified chlorinated polyolefin (A) and a curing agent (B) reactive with a hydroxyl group as an essential coating film forming component is used,
[0018]
In addition, as the above-described base coat coating material, a vinyl polymer (C) having a hydroxyl group and / or a polyester resin (D) having a hydroxyl group, which contains a metallic powder and / or a color pigment, and a curing having reactivity with the hydroxyl group. Using a paint containing an agent (E) as an essential coating film-forming component,
[0019]
Further, as the above-described clear coat coating material, a vinyl polymer (F) having at least two siloxy groups in one molecule, and a curing agent (G) reactive with a hydroxyl group generated from the polymer (F) (G) ) And a siloxy group dissociation promoting catalyst (H) as an essential coating film forming component, a coating film forming method is provided.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
In this patent application (hereinafter abbreviated as the present application), after applying an undercoat paint to a polyolefin-based substrate to form an undercoat paint film, a base coat paint is applied to the above-described undercoat paint surface. And then applying a clear coat paint on the base coat paint, respectively,
[0021]
As the above-described undercoat paint, a paint containing a hydroxyl group-containing vinyl-modified chlorinated polyolefin (A) and a curing agent (B) reactive with the hydroxyl group as an essential coating film forming component is used.
[0022]
Further, as the above-mentioned base coat paint, a vinyl polymer (C) having a hydroxyl group and / or a polyester resin (D) having a hydroxyl group, in which metallic powder and / or a color pigment are blended, and the reactivity with the hydroxyl group. Using a coating material having the curing agent (E) as an essential coating film forming component,
[0023]
Further, as the above-described clear coat coating material, a vinyl polymer (F) having at least two siloxy groups in one molecule, and a curing agent (G) reactive with a hydroxyl group generated from the polymer (F) (G) ) And a siloxy group dissociation promoting catalyst (H) as an essential coating film forming component, a coating film forming method is claimed.
[0024]
The present application also claims the above-described method of using at least one compound selected from the group consisting of a polyisocyanate compound and an amino resin as the curing agent (B) having reactivity with a hydroxyl group. And
[0025]
Furthermore, the present application claims the above-described method of using at least one compound selected from the group consisting of a polyisocyanate compound and an amino resin as the curing agent (E) having reactivity with a hydroxyl group. And
[0026]
Furthermore, the present application also relates to a method of using a compound having both a siloxy group that generates a hydroxyl group by hydrolysis and a hydrolyzable silyl group bonded to a carbon atom as the vinyl polymer (F). You ’re billing,
[0027]
In addition, the present application uses at least one compound selected from the group consisting of a polyisocyanate compound, a carboxylic acid anhydride group-containing compound, and an epoxy compound as the curing agent (G) having reactivity with a hydroxyl group as described above. The method is also charged.
[0028]
"Constitution"
[0029]
In the following, the present invention will be described in more detail.
[0030]
First, the above-mentioned polyolefin base material used in carrying out the method for forming a coating film according to the present invention is various α such as ethylene, propylene, 1-butene or 3-methyl-1-heptene. -Refers to various molded articles and structures, such as olefin homopolymers or copolymers,
[0031]
As described above, not only various molded articles and structures of pure polyolefin, but also so-called polymer alloyed forms in which different resin materials are blended are included. Of course, those in which various fillers such as titanium oxide, talc, silica, etc. are blended are also included.
[0032]
The above-mentioned hydroxyl group-containing vinyl-modified chlorinated polyolefin (A) to be used for the undercoat paint used for carrying out the method for forming a coating film according to the present invention is an essential component of a hydroxyl group-containing unsaturated monomer. A vinyl-modified chlorinated polyolefin obtained by polymerizing a vinyl monomer with a specific chlorinated polyolefin and grafted onto the chlorinated polyolefin. It is what we call
[0033]
Preferably, a vinyl monomer containing a hydroxyl group-containing unsaturated monomer and an unsaturated carboxylic acid as essential components is polymerized with a specific chlorinated polyolefin having a chlorination rate of 50% or less. In this form, a vinyl-based monomer is referred to as a vinyl-modified chlorinated polyolefin grafted on this chlorinated polyolefin.
[0034]
  In particular, 5 to 30% by weight of the hydroxyl group-containing vinyl monomer (a-1) and the unsaturated carboxylic acid (a-) with respect to the chlorinated polyolefin (a-0) having a chlorination rate of 50% or less. 2) 0.1 to 3% by weight, and 0 to 10% by weight of the polyester resin (a-3) having a polymerizable unsaturated double bond (hereinafter also referred to as unsaturated bond) that can be copolymerized;
[0035]
50 to 97.9% by weight of the other vinyl monomer (a-4) which can be copolymerized with (a-1), (a-2) and (a-3), respectively. In such a way that the total amount of each of the monomers (a-1), (a-2), (a-3) and (a-4) is 100% by weight,
[0036]
Moreover, the solid content weight ratio of the chlorinated polyolefin (a-0) and the mixture of the monomers is 10:90 to 90:10 in the presence of the organic solvent. Particularly preferred is a graft copolymer obtained by polymerization and having a number average molecular weight of 3,000 to 40,000.
[0037]
Here, the above-mentioned chlorinated polyolefin (a-0) usually refers to a polyolefin having a chlorination rate of 50% or less, preferably 10 to 40%. To illustrate only those, homopolymers or copolymers of various α-olefins such as ethylene, propylene, 1-butene, 3-methyl-1-butene or 3-methyl-1-heptene. Polymer;
[0038]
Or a copolymer of α-olefins and other vinyl monomers such as ethylene-vinyl acetate copolymer, ethylene-butadiene copolymer or ethylene-acrylic acid ester copolymer. Accordingly, only typical examples of the chlorinated polyolefin (a-0) can be exemplified as chlorinated polyethylene, chlorinated polypropylene, chlorinated ethylene-propylene copolymer or chlorinated ethylene-vinyl acetate. Such as a copolymer.
[0039]
With respect to the chlorination rate of the chlorinated polyolefin (a-0), if the chlorination rate exceeds 50%, the chlorination rate is inevitably lowered because the adhesion to the polyolefin-based substrate tends to decrease. The rate should be determined mainly in consideration of various coating film performances such as (substrate) adhesion, flexibility and hardness, and preferably within a range of 10 to 40%. More preferably, it should be in the range of 15 to 35%, and in this way, a composition having the most balanced film performance can be obtained.
[0040]
Further, only the typical examples of the hydroxyl group-containing vinyl monomer (a-1) described above are illustrated as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3 -Hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, di- Such as 2-hydroxyethyl fumarate or mono-2-hydroxyethyl-monobutyl fumarate.
[0041]
Further, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate or 4-hydroxy Butyl (meth) acrylate or 3-chloro-2-hydroxypropyl (meth) acrylate, di-2-hydroxyethyl fumarate or mono-2-hydroxyethyl monobutyl fumarate, ethylenoxide, propylene oxide, butylene Also included are so-called long-chain hydroxyl group-containing monomers in the form of an addition reaction of oxide or ε-caprolactone, usually in the range of 1 to 6 mol.
[0042]
These may be used singly, in combination of two or more, or in combination with a hydroxyl group-containing monomer before such an addition reaction. Of course, it should be decided each time.
[0043]
  By the way, if the typical usage amount of the hydroxyl group-containing vinyl monomer (a-1) is mentioned, if it is less than 5% by weight, the above-mentioned curing having a reactivity with the hydroxyl group is absolutely necessary. When combined with the agent (B), the solvent resistance and chemical resistance tend to be insufficient. On the other hand, if the amount is too much more than 50% by weight, the adhesion to the polyolefin material tends to decrease. Therefore, the range of 5 to 50% by weight, preferably the range of 5 to 40% by weight, is appropriate with respect to the total weight of the monomers.
[0044]
Furthermore, only representative examples of the unsaturated carboxylic acid (a-2) described above are exemplified by various unsaturated dicarboxylic acids such as maleic anhydride, fumaric acid, itaconic acid or citraconic acid; or And various unsaturated monocarboxylic acids such as (meth) acrylic acid.
[0045]
  And if a typical thing is mentioned especially as usage-amount of the said unsaturated carboxylic acid (a-2), when these are less than 0.1 weight%, the hardening | curing agent (reacting with a hydroxyl group by all means) When combined with B), in particular, the curability is likely to be insufficient, and on the other hand, if it is more than 3% by weight, the water resistance of the coating film tends to decrease. In the range of 0.1 to 3% by weight, preferably in the range of 0.2 to 1.5% by weight, based on the total amount of monomers.
[0046]
Furthermore, the polyester resin (a-3) having an unsaturated bond that can be copolymerized is not limited to a pigment having a small oil absorption, such as an acid value titanium or a stalk. In particular, in the case of wanting to improve the dispersibility of various organic pigments such as quinacridone, phthalocyanine or azo, and pigments with poor dispersibility and relatively large oil absorption, such as carbon black. In that sense, it can be said that the polyester resin is not much involved in the coating performance itself.
[0047]
The polyester resin (a-3) is exemplified only by typical ones, including so-called alkyd resins modified with oils or fatty acids, and further by these fats and oils. Any unmodified form of so-called oil-free alkyd resin can be used. In the present invention, among these various alkyd resins, in particular, various vinyl monomers are used. A polymerizable type having an unsaturated bond can be said to be particularly suitable.
[0048]
At this time, the alkyd resin does not have a copolymerizable unsaturated bond or has a small number of unsaturated bonds, such as a saturated fatty acid or a non-drying oil (fatty acid) modified type, respectively, or an oil or For oil-free alkyd resins that have not been modified with fatty acids, the copolymerizable unsaturated bond that should be the grafting point for various other vinyl monomers is added to (anhydrous) maleic acid or fumaric acid. It goes without saying that it is necessary to introduce various carboxylic acids such as acids into the alkyd resin.
[0049]
  The alkyd resin thus obtained is usually used in the range of 0 to 10% by weight, but if it is used in an excessive amount exceeding 10% by weight, it must be solvent resistant. In addition, the stain resistance is deteriorated, which is not preferable.
[0050]
Subsequently, only those particularly representative as other vinyl monomers (a-4) which can be copolymerized with (a-1), (a-2) and (a-3), respectively. Various aromatic vinyl monomers such as styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene;
[0051]
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso (i- or iso-) propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, dibromopropyl (meth) ) Various (meth) acrylates such as acrylate, tribromophenyl (meth) acrylate or alkoxyalkyl (meth) acrylate;
[0052]
Various epoxy group-containing monomers such as glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate or (meth) allyl glycidyl ether;
[0053]
2,3-carbonate propyl (meth) acrylate, 2-methyl-2,3-carbonate propyl (meth) acrylate, 4-methyl-3,4-carbonate butyl (meth) acrylate, 3-methyl-3,4-carbonate Various cyclocarbonate group-containing vinyl monomers such as butyl (meth) acrylate, 5-ethyl-5,6-carbonate hexyl (meth) acrylate;
[0054]
Diesters of various unsaturated dicarboxylic acids such as maleic acid, fumaric acid or itaconic acid with monohydric alcohols; vinyl acetate, vinyl benzoate or “veova” (branched aliphatic from Ciel, Netherlands) Various vinyl esters such as the monocarboxylic acid vinyl ester trade name);
[0055]
"Biscoat BF, BFM, 3F or 3FM" [trade name of fluorine-containing acrylic monomer manufactured by Osaka Organic Chemical Co., Ltd.], perfluorocyclohexyl (meth) acrylate, diperfluorocyclohexyl fumarate or Ni- -Vinyl esters, -vinyl ethers,-(meth) acrylates or -unsaturated carboxylic acid esters containing various (per) fluoroalkyl groups such as propylperfluorooctanesulfonamidoethyl (meth) acrylate, respectively. Various fluorine-containing compounds such as
[0056]
Alternatively, various nitrogen atom-containing compounds such as (meth) acrylamide or (meth) acrylonitrile; various halogenated olefins such as vinyl chloride, vinylidene chloride, vinyl fluoride, or vinylidene fluoride.
[0057]
  And when polymerizing various monomers (mixtures) as described above with respect to the chlorinated polyolefin (a-0), these chlorinated polyolefins and monomers (mixtures) The ratio of the solid content is within the range of the solid content weight ratio of 10:90 to 90:10, and preferably within the range of the solid content weight ratio of 15:85 to 60:40 It is.
[0058]
Further, through such a polymerization reaction, the vinyl monomer component is grafted to the chlorinated polyolefin component, and as a result, a so-called graft copolymer which is a modified chlorinated polyolefin in a form imparted with good compatibility. However, as a method of such a polymerization reaction, various known and usual methods such as benzoyl peroxide or azobisisobutyronitrile are usually used at a polymerization temperature in the range of about 60 to 100 ° C. It is better to perform solution polymerization using the radical generating polymerization initiator of
[0059]
In this case, the ratio between the chlorinated polyolefin (a-0) and the monomer (mixture) described above was more than 10:90 in terms of solid content weight ratio, and was too chlorinated. When the amount of polyolefin decreases, it is inevitably unfavorable because there is a tendency for adhesion to polyolefin base materials to decrease. On the other hand, exceeding 90:10, the amount of chlorinated polyolefin increases too much. In such a case, the solvent resistance of the coating film obtained is inevitably lowered, which is not preferable.
[0060]
Here, only typical examples of the organic solvent described above are exemplified, and well-known solvents such as toluene or xylene are well known as good solvents for chlorinated polyolefin. In addition, it can be said that butyl acetate, especially n-butyl acetate or butanol is used as long as the solubility is not impaired.
[0061]
  The graft copolymer obtained as described above must first have a number average molecular weight (Mn) in the range of 3,000 to 40,000, preferably 5,000 to 30. In the case where the molecular weight is lower than 3,000, it tends to be insufficient in terms of mechanical strength and the like. In the case of a molecular weight higher than 000, it is inevitably difficult to obtain a sufficient product in terms of spray workability.
[0062]
Next, as the above-described curing agent (B) having reactivity with a hydroxyl group, which is one of the essential components constituting the above-described undercoat paint used in carrying out the method of the present invention, It is desirable to use amino resins and / or polyisocyanate compounds. In particular, this amino resin is particularly desirable from the viewpoint of ease of use.
[0063]
Examples of such amino resins are alkyl etherified melamine resins and the like, and only typical examples of such alkyl etherified melamine resins are as follows.
[0064]
Various butoxymethyl melamine resins such as “Super Becamine L-117-60” [Dainippon Ink Chemical Co., Ltd. product] or “Uban 225” [Mitsui Toatsu Chemicals Co., Ltd. product]; Alternatively, various methoxymethyl melamine resins such as # 303 "[Mitsui Cyanamid (available) product] or" Sumimar M-100 "[Sumitomo Chemical Co., Ltd. product];
[0065]
Alternatively, various methoxy-ptoxy mixed etherified methyl melamine resins such as “Cymel # 1130” (product of the same company) or “Sumimar M-66B” (product of the same company).
[0066]
  And as the usage-amount of the said amino resin, the inside of the range which is 5 to 40 weight% with respect to the resin total amount is suitable, Preferably the inside of the range which is 10 to 30 weight% is suitable.
[0067]
In the present invention, a so-called curing catalyst can be used to accelerate the curing of the undercoat, but such a curing catalyst when an amino resin is used as the curing agent (B) having reactivity with a hydroxyl group. In particular, only typical ones are illustrated as follows: para-toluenesulfonic acid (p-toluenesulfonic acid), dodecylbenzene sulfonic acid, dinonylnaphthalenedisulfonic acid, amine-blocked products thereof, tetrachloro, etc. Various acid catalysts such as half-esterified products of phthalic anhydride and monohydric alcohols and various organic acids such as trichloroacetic acid;
[0068]
Alternatively, various phosphoric acid compounds such as monoalkyl phosphoric acid, dialkyl phosphoric acid, monoalkyl phosphorous acid or dialkyl phosphoric acid, or triphenylphosphine. And as a usage-amount of the said curing catalyst, the inside of the range which is 0.1 to 10 weight% with respect to resin total amount is suitable.
[0069]
Of course, block isocyanate, epoxy resin, and the like can be used as the curing agent as required.
[0070]
  In the present invention, as the undercoat paint, a hydroxyl group value (OH value) of 50 to 200 and a linear or branched polyester polyol and / or polyether polyol are used as necessary. Can also be used.
[0071]
Specific examples of the polyol include polyethylene glycol ether, polypropylene glycol ether, polytetramethylene glycol or polycaprolactone polyol, which may be used alone or in combination of two or more.
[0072]
The kind of the polyol component and the amount of use should be determined by the degree of hardness of the resin skeleton such as acrylic resin or amino resin, and the acrylic resin used has a low glass transition temperature (Tg). When is used, it is preferable that the amount of the polyol used is small and the hydroxyl value is high.
[0073]
  The amount used is appropriately such that it is less than 50 parts by weight with respect to 100 parts by weight of the solid content of the hydroxyl group-containing vinyl-modified chlorinated polyolefin (A). If it exceeds 50 parts by weight and it is used in an excessively large amount, it is inevitably unfavorable because the solvent resistance becomes inferior.
[0074]
The above-described base coat paint used in the present invention includes a vinyl polymer (C) and / or a polyester resin (D) each having a hydroxyl group in a form in which a metallic powder and / or a color pigment is blended. These hydroxyl groups and reactive curing agents (E) are contained as essential coating film forming components, and various known and commonly used types may be used.
[0075]
Specifically, a known and commonly used vinyl polymer (C) such as an acrylic resin having a hydroxyl group and / or a known and commonly used polyester resin (D) having a hydroxyl group, a polyisocyanate compound and / or A curable resin composition in the form of a combination of a hydroxyl group, which is an amino resin, and a reactive curing agent (E), in which a metallic powder and / or a color pigment is blended as an essential film forming component It is.
[0076]
The polyester resin referred to here includes alkyd resins modified with oils or fatty acids. Further, cellulose acetate acetate butyrate may be used.
[0077]
If only typical examples of the base coat paint are exemplified, organic solvent-soluble resins or non-aqueous dispersion resins are used, and water-soluble resins and / or emulsion resins are the main components. Any type of so-called aqueous base coat can be used.
[0078]
Next, the clear coat paint, which is one of the main components used in carrying out the coating film forming method according to the present invention, will be described. Is a vinyl polymer (F) having at least two siloxy groups in one molecule, a curing agent (G) having reactivity with a hydroxyl group produced from the polymer (F), a siloxy group This refers to a coating system containing a dissociation promoting catalyst (H) as an essential coating film forming component.
[0079]
Here, the vinyl polymer (F) having at least two siloxy groups in one molecule is a siloxy group represented by the following general formula [I] in one molecule. And a compound having a structure in which the siloxy group is bonded to a carbon atom.
[0080]
[Chemical 1]

[0081]
[However, R in the formula¹ Represents an alkyl group having 1 to 18 carbon atoms, or a phenyl group, an aryl group or an aralkyl group, and R² And R^Three Each may be the same or different and each represents a hydrogen atom or a halogen atom, or an alkyl group, cycloalkyl group, alkoxyl group, cycloalkoxy group, aryl group, aryloxy group, alkanoyloxy group, aralkyl An alkyl group having 1 to 18 carbon atoms which may be substituted or not substituted with at least one atomic group selected from the group consisting of a group, an aralkyloxy group, a nitrile group and a halogen atom; Or aryl group, cycloalkyl group, aralkyl group, alkanoyl group, alkoxyl group, aryloxy group, cycloalkoxy group, aralkyloxy group or alkanoyloxy
It shall represent a group. ]
[0082]
Examples of such siloxy groups include, but are not limited to, trimethylsiloxy group, triethylsiloxy group, triphenylsiloxy group, dimethylethoxysiloxy group, or triethoxysiloxy group. It can be said that a siloxy group or a trialkoxysiloxy group has a preferred structure.
[0083]
In order to obtain the vinyl polymer (F), for example, (1) a vinyl monomer having a siloxy group as described above may be polymerized alone, or the siloxy group-containing vinyl monomer Or other monomers that can be copolymerized with the monomer, or (2) hydroxyl group-containing vinyl polymers prepared in advance such as chlorosilane. In addition, a method such as reaction with a so-called silylating agent or (3) alcohol exchange reaction between alkoxysilanes and hydroxyl groups may be used. The union (F) can be prepared, but it is preferable to use the method (1) because of its ease of preparation.
[0084]
In order to exemplify only typical examples of the siloxy group-containing vinyl monomer (f-1) used in preparing the vinyl polymer (F) by the above method (1). If you keep, 2-trimethylsiloxyethyl (meth) acrylate, 2-trimethylsiloxypropyl (meth) acrylate, 4-trimethylsiloxybutyl (meth) acrylate, 2-triethylsiloxyethyl (meth) acrylate, 3-tributylsiloxypropyl ( And (meth) acrylate, 2-trimethylsiloxyethyl vinyl ether, 4-trimethylsiloxybutyl vinyl ether or 2-trimethylsiloxyethyl-allyl ether.
[0085]
Of course, such a siloxy group-containing monomer (f-1) may be used alone or in combination of two or more of these monomers (f-1).
[0086]
Other monomers (f-2) copolymerizable with this siloxy group-containing vinyl monomer (f-1) are the hydroxyl group-containing vinyl monomers (a) mentioned above, respectively. -1), an unsaturated carboxylic acid (a-3), a vinyl monomer (a-4), etc. .
[0087]
In particular, with respect to these monomers (f-2), the vinyl polymer (F) having at least two siloxy groups in one molecule described above has a further effect of the present invention. In other words, in order to form a coating film excellent in various performances such as acid resistance, coating film appearance, hardness and weather resistance, on the polyolefin base material, hydrolyzability bonded to a carbon atom. It is desirable to coexist with a silyl group (hereinafter hydrolyzable silyl group).
[0088]
  Here, in the vinyl polymer (F), the hydrolyzable silyl group that should coexist with the siloxy group refers to a compound represented by the following general formula [II]. Is.
[0089]
[Chemical 2]

[0090]
[However, R in the formula^Four Is a hydrogen atom or an alkyl group, aryl group or aralkyl group, R^Five Represents a halogen atom or a (substituted) alkoxy group, an acyloxy group, a phenoxy group, a mercapto group, an amino group, an iminooxy group or an alkenyloxy group, and a is an integer of 0, 1 or 2
Shall. ]
[0091]
Only typical examples of such hydrolyzable silyl groups are exemplified by halosilyl groups, alkoxysilyl groups, acyloxysilyl groups, phenoxysilyl groups, mercaptosilyl groups, aminosilyl groups, iminooxysilyl groups or alkenyls. Although it is an oxysilyl group etc., it can be said that an alkoxysilyl group has a preferable structure also from the viewpoint that undesirable volatile components are not generated during curing.
[0092]
In order to contain this hydrolyzable silyl group in the vinyl polymer (F), the monomer (f-2) used in preparing the vinyl polymer (F) is used. ) Partly or entirely of a hydrolyzable silyl group-containing vinyl monomer [herein, the monomer is referred to as (f-3). ] May be used.
[0093]
Examples of such hydrolyzable silyl group-containing vinyl monomers (f-3) are only typical ones: 3- (meth) acryloyloxypropyltrichlorosilane, 2- (meth) acryloyloxy Propyldichlorosilane, allylmethyldichlorosilane; 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, allyltrimethoxysilane; Vinyltriphenoxysilane, bis (dimethylamino) methylvinylsilane and the like are not limited to these illustrative examples.
[0094]
Of course, the hydrolyzable silyl group-containing vinyl monomer (f-3) may be used alone or in combination of two or more.
[0095]
In order to prepare the vinyl polymer (F) from various vinyl monomers as listed above, various known and conventional methods can be applied. The simplest method is a solution polymerization method using a polymerization initiator, that is, a method such as a solution radical polymerization method.
[0096]
  As the amount of the siloxy group to be introduced into the vinyl polymer (F), from the viewpoint of curability, as a repeating unit having a siloxy group, based on the solid content of the polymer (F), The range of 1 to 100% by weight, preferably 3 to 100% by weight, is appropriate.
[0097]
  In addition, the number average molecular weight of the polymer in a state where the vinyl copolymer (F) has generated a hydroxyl group by hydrolysis is suitably in the range of 1,000 to 50,000. The hydroxyl value of the polymer in this state is suitably in the range of 20 to 200.
[0098]
In the case of a vinyl polymer that does not fall within these ranges, it is inevitably inferior in curability or the like, and remarkably decreases in storage stability. .
[0099]
Next, as the above-described curing agent (G) having reactivity with a hydroxyl group, any compound can be used as long as it has a group (hydroxyl reactive group) that reacts with at least two hydroxyl groups in the molecule. In particular, it is selected from the group consisting of a polyisocyanate compound, a carboxylic acid anhydride group-containing compound and an epoxy compound from the viewpoint of acid resistance, ease of handling, and performance of the coating film to be formed. It is desirable to use at least one compound.
[0100]
Of these compounds (G), only typical examples of polyisocyanate compounds are exemplified. Various aromatic diisocyanates such as tolylene diisocyanate or diphenylmethane diisocyanate; or hexamethylene diisocyanate or Various aliphatic diisocyanates such as trimethylhexane diisocyanate;
[0101]
Various alicyclic diisocyanates such as isophorone diisocyanate, methylcyclohexane-2,4 (2,6) -diisocyanate, 4,4-methylenebis (cyclohexylisocyanate) or 1,3- (isocyanatomethyl) cyclohexane;
[0102]
Various diisocyanates as listed above, various polyhydric alcohols including ethylene glycol, trimethylolethane or trimethylolpropane, various polyether polyols such as polyethylene glycol or polypropylene glycol, Adducts with relatively low molecular weight polyester resins (including oil-modified types) and acrylic copolymers such as polycaprolactone polyols having functional groups that react with isocyanate groups;
[0103]
Alternatively, polyisocyanates having a so-called bullet structure obtained by reacting various diisocyanates as described above with water; or so-called isocyanurate ring-containing polyisocyanates obtained by cyclopolymerizing diisocyanates. Etc.
[0104]
Of these curing agents (G), only typical examples of the carboxylic acid anhydride group-containing compound or epoxy compound are exemplified, and vinyl polymers, polyester polymers, polyethers are exemplified. In addition to various resins such as a polymer or an epoxy resin, and various polymers or resins as listed above, various carboxylic acid anhydride groups and epoxy groups are present. And the like.
[0105]
Of these curing agents (G), only typical ones as vinyl polymers are exemplified. Acrylic, vinyl ester, aromatic vinyl, polyolefin, and chlorinated olefins. System- or fluoroolefin-based vinyl polymers.
[0106]
Among the curing agents (G), the vinyl polymer may be obtained by homopolymerizing a vinyl monomer having a carboxylic acid anhydride group, an epoxy group, or the like, or other copolymerizable as described above. It can be easily prepared by copolymerizing with the monomers (f-2).
[0107]
Here, only typical examples of the vinyl monomer having an acid anhydride group used in preparing the vinyl polymer of the curing agent (G) are exemplified. For example, various carboxylic acid anhydride-containing unsaturated monomers such as maleic anhydride, itaconic anhydride or methacrylic anhydride,
[0108]
Only typical examples of the vinyl monomer having an epoxy group include glycidyl (meth) acrylate, allyl glycidyl ether, 3,4-epoxycyclohexyl (meth) acrylate, or vinyl glycidyl ether. These are various epoxy group-containing unsaturated monomers, but, of course, are not particularly limited to these exemplified compounds.
[0109]
Of these curing agents (G), glycerol tris (trimellitate) or anhydrous glycerol tris (trimellitate) can be used as long as it is a compound having a carboxylic acid anhydride group and is only representative as a compound other than a vinyl polymer. And various polyhydric carboxylic acid anhydrides represented by anhydrous ethylene glycol di (trimellitate).
[0110]
Further, among the curing agents (G), compounds having an epoxy group, and only typical ones other than the vinyl polymer will be exemplified. Ethylene glycol diglycidyl ether, neo Various polyglycidyl ethers of various polyhydric alcohols such as pentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether or glycerin triglycidyl ether;
[0111]
Various polyglycidyl esters of various polycarboxylic acids such as diglycidyl ester of phthalic acid, diglycidyl ester of isophthalic acid or diglycidyl ester of adipic acid; Novolac epoxy resin or epoxy resin containing hydantoin ring;
[0112]
An alicyclic epoxy resin having at least two alicyclic oxirane groups in one molecule, as represented by “Epolide GT Series” [product of Daicel Chemical Industries, Ltd.]; or p-oxybenzoic acid So-called polyepoxy compounds such as various epoxy resins such as glycidyl ester ether of acid.
[0113]
Furthermore, the dissociation promoting catalyst (H) used in carrying out the method for forming a coating film according to the present invention is the above-described dissociation promoting catalyst (H), wherein the siloxy group of the vinyl polymer (F) is reacted with moisture. It refers to a compound that is hydrolyzed to promote the regeneration of hydroxyl groups. Among them, only typical ones are listed, including phosphoric acids, phosphate esters, phosphite esters, unsaturated group-containing phosphate esters,
[0114]
various acidic catalysts such as p-toluenesulfonic acid or amine salts thereof; benzoic acid, trichloroacetic acid, naphthalene disulfonic acid or amine salts thereof;
[0115]
Tetramethylammonium fluoride, tetraethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium hydroxide, 2-hydroxypyridine, trimethylammonium methoxide, phenyltrimethylammonium chloride, phenyltrimethylammonium bromide, phenyltrimethylammonium hydroxide, phenyl Including trimethylammonium iodide, phenyltrimethylammonium bromide, phosphocholine chloride sodium salt,
[0116]
Stearyl ammonium bromide, tetra-n-butylammonium hydroxide, tetra-n-butylammonium phosphate, tetra-n-dodecylammonium trichloride, tetraethylammonium hydroxide, tetraethylammonium tetrafluoroborate, acetylcholine bromide Various quaternary ammoniums such as alkyldimethylbenzylammonium chloride, benzylcholine bromide, benzyl-n-butylammonium bromide, betaine, butyryl chloride, bis (tetra-n-butylammonium) dichromate or trimethylvinylammonium bromide salts;
[0117]
Allyltriphenylphosphonium chloride, n-amyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, bromomethyltriphenylphosphonium bromide, 2-dimethylaminoethyltriphenylphosphonium bromide, ethoxycarbonylphos Various phosphonium salts such as phonium bramide, n-heptyltriphenylphosphonium bromide, methyltriphenylphosphonium bromide, tetrakis (hydroxymethyl) phosphonium sulfate or tetraphenylphosphonium bromide;
[0118]
Metal salts of various carboxylic acids such as alkyl titanates, octylates, dibutyltin dilaurate or lead octylates; various sulfidic or mercaptide organic compounds such as monobutyltin sulfide or dioctyltin mercaptides; Various alkaline catalysts such as lithium or potassium hydroxide;
[0119]
Amines such as ethylenediamine, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, butylamine, dibutylamine, tert-butylamine, hexylamine, 2-ethylhexylamine, triethylamine, diethanolamine, triethanolamine;
[0120]
Various basic catalysts such as 1,8-diazabicyclo (5,4,0) undecene-7 or 1,4-diazabicyclo (2,2,2) octane; or various carbonates such as calcium carbonate It is.
[0121]
  The addition amount of these catalysts is suitably within the range of 0.001 to 10%, preferably within the range of 0.005 to 6%, relative to the vinyl polymer (F) described above. Is appropriate.
[0122]
In order to further improve the stability of the clear coat paint used in the present invention thus obtained, a so-called water binder (moisture supplement) can be added.
[0123]
Of those that can be used as such water binders, only typical ones are exemplified. Various trialkyl orthoformates such as trimethyl orthoformate, triethyl orthoformate or tributyl orthoformate; trimethyl orthoacetate Various trialkyl orthoacetates such as triethyl orthoacetate or tributyl orthoacetate; various trialkyl orthoborates such as trimethyl orthoborate, triethyl orthoborate or tributyl orthoborate;
[0124]
Various tetra (substituted) alkyl silicates such as tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, tetra (2-methoxyethyl) silicate or tetra (2-chloroethyl) silicate; tetraphenyl silicate or tetrabenzyl silicate , Various synergistic substances of the above tetra (substituted) alkyl silicates (hereinafter abbreviated as synergistic simple substance);
[0125]
Alternatively, various kinds of tops such as “ethyl silicate 40” (trade name of tetraethyl silicate tetramer, pentamer or hexamer made by Colcoat, USA) such as tetraethyl silicate dimer, trimer, tetramer or hexamer, etc. Various hydrolyzable ester compounds such as the tetra (substituted) alkyl silicates listed above, and condensates of the synergistic single units of the silicates;
[0126]
Furthermore, there are various isocyanate group-containing compounds such as phenyl isocyanate, p-chlorophenyl isocyanate, benzenesulfonyl isocyanate, p-toluenesulfonyl isocyanate, or isocyanate ethyl methacrylate.
[0127]
As described above, when various water binders are added, the amount of the water binder used is 0.1 to 20 with respect to the total amount of resin solids constituting the clear coat paint. The amount may be about% by weight, preferably about 0.5 to 10% by weight.
[0128]
For the clear coat paint used in the present invention thus obtained, various known and commonly used paints such as a leveling agent, a rheology control agent, a light stabilizer or an ultraviolet absorber may be used as necessary. Additives can also be added.
[0129]
Moreover, various well-known and commonly used cellulose compounds, plasticizers, polyester resins and the like can be blended.
[0130]
As a method of forming a coating film on the polyolefin-based material using the undercoat paint, the base coat paint and the clear coat paint used in the present invention, respectively, a usual method can be used.
[0131]
In other words, polyolefin-based materials may not be subjected to any pre-painting treatment, but usually, removal of machine oil and mold release agent attached to the surface of plastic molded products and improvement of adhesion are required. The intended so-called pre-processing is performed.
[0132]
Such pre-treatment methods include solvent wiping for the purpose of removing surface adhesives, water-based cleaning using water-based cleaning agents, steam cleaning with trichloroethane, flame processing, or plasma processing. and so on.
[0133]
The method for forming a coating film according to the present invention is to apply an undercoat paint, a base coat paint, and a clear coat paint, and as a coating method at that time, spray coating or electrostatic coating is suitable, Although the coating interval of the base coat is not particularly limited, when the clear coat paint is applied, after the base coat paint is applied, the base coat paint is in a touch-dried or semi-cured state. It is particularly desirable to do so.
[0134]
As drying conditions after applying each paint, room temperature drying or heat drying is also possible, depending on the coating equipment and drying equipment at that time, the type of each paint, their characteristics, etc. It may be determined as appropriate.
[0135]
  Thus, the film thickness of each coating film formed by the method of the present invention is 5 to 15 micrometer (μm) in the case of a base coat and 15 to 15 in the case of a base coat. In the case of 30 μm, and in the case of a clear coat paint, it is desirable to adjust to 20 to 60 μm.
[0136]
【Example】
Next, the present invention will be described more specifically by reference examples, examples and comparative examples. However, the present invention is in no way limited to these illustrated examples. In the following, all parts and% are based on weight unless otherwise specified.
[0137]
Reference Example 1 [Preparation Example of Vinyl-Modified Chlorinated Polyolefin (A)]
In a reaction vessel equipped with a stirrer and a cooler, “Hardlen 14ML” [trade name of chlorinated polypropylene manufactured by Toyo Kasei Kogyo Co., Ltd .; chlorination rate = 26%, solid content (nonvolatile content) = 30%] 500 parts and 800 parts of toluene were added, and the internal temperature was raised to 80 ° C.
[0138]
There, 200 parts of methyl methacrylate (MMA), 200 parts of isobutyl methacrylate (IBMA), 300 parts of ethyl acrylate (EA), 140 parts of 2-hydroxyethyl methacrylate (HEMA) and 10 parts of methacrylic acid (MAA) Then, 5 parts of benzoyl peroxide (BPO) and 5 parts of azobisisobutyronitrile (AIBN) were dissolved in 350 parts of n-butyl acetate dropwise over 3 hours.
[0139]
Thereafter, the polymerization reaction was continued at the same temperature for 12 hours, and the polymerization reaction was continued. This was a chlorinated polypropylene-modified acrylic resin having a nonvolatile content of 40.2 and a number average molecular weight of 25,000. A solution of vinyl-modified chlorinated polyolefin (A) was obtained. Hereinafter, this is abbreviated as a copolymer (A-1).
[0140]
Reference example 2 (same as above)
In a reaction vessel similar to that in Reference Example 1, 660 parts of “Harden 14ML” and 688 parts of toluene were placed, and the temperature in the vessel was raised to 80 ° C.
[0141]
There, 350 parts of MMA, 180 parts of cyclohexyl methacrylate (CHMA), 262 parts of “Plexel FM-1” (trade name of hydroxyethyl methacrylate-ε-caprolactone adduct made by Daicel Industries, Ltd.) and methacryl 10 parts of acid (MAA), 6 parts of benzoyl peroxide (BPO) and 4 parts of azobisisobutyronitrile (AIBN) dissolved in 350 parts of n-butanol for 3 hours It was dripped over.
[0142]
Thereafter, when the polymerization reaction is continued for 12 hours at the same temperature, the non-volatile content is 40.8 and the number average molecular weight is 27,000, which is a chlorinated polypropylene-modified acrylic resin. A solution of vinyl-modified chlorinated polyolefin (A) was obtained. Hereinafter, this is abbreviated as a copolymer (A-2).
[0143]
Reference Examples 3 and 4 (Preparation example of undercoat paint)
112.5 parts of each of copolymer (A-1) or (A-2), 40 parts of titanium oxide, and 20 parts of xylene, respectively, in a sand mill for 1 hour Each white enamel was obtained by mashing.
[0144]
Then, each of these white enamels was mixed with 25 parts of “Super Becamine L-117-60” (trade name of the amino resin manufactured by the previous company; solid content = 60%) and “Nacure N-5225” [Enomoto Kasei Co., Ltd. 1.6 parts of the trade name of “Dodecyl benzene sulfonate amine block product” manufactured by Co., Ltd., and then thinner that is toluene / xylene / n-butanol = 20/60/20 (parts by weight). Thus, it was diluted to spray viscosity. Hereinafter, those using the copolymer (A-1) are abbreviated as the undercoat paint (P-1), and those using the copolymer (A-2) are used as the undercoat paint (P-2). Abbreviated.
[0145]
Reference Example 5 (Preparation example of base coat paint)
The resin composition for paints in the form blended by the usual paint production method so as to have the following ratio is used as a diluent solvent [xylene / toluene / n-butyl acetate / methyl ethyl ketone = 30/30/20 / 20 (parts by weight)], Ford Cup NO. 4 was adjusted to a viscosity of 11 to 12 seconds to obtain a base coat paint. Hereinafter, this base coat paint is abbreviated as (BC-1).
[0146]
"Beckolite GF-542" 77 parts
[Dainippon Ink Chemical Co., Ltd.
Hydroxyl-containing polyester resin
Product name; non-volatile content = 65%]
42 parts of "Super Becamine L-117-60"
(N-Butylated Melami manufactured by the company
Non-volatile content = 6
0%)
"CAB-381-0.5" 25 parts
(Eastman Koda, USA)
Cellulose acetate manufactured by Cook
Tate Butyrate trade name)
"EPOLEN N-10" 15 copies
(Wax made by the same company)
"Alpaste 1860YL" 23 parts
[Aluminum made by Toyo Aluminum Co., Ltd.
Product name of Ni paste; non-volatile
Departure = 65%]
"Nature N-5225" 1 copy
[0147]
Reference Example 6 (same as above)
The resin composition for paints in the form blended by the usual paint production method so as to have the following ratio is used as a diluent solvent [xylene / toluene / n-butyl acetate / methyl ethyl ketone = 30/30/20 / 20 (parts by weight)], Ford Cup NO. 4 was adjusted to a viscosity of 13 to 14 seconds to obtain a base coat paint. Hereinafter, this base coat paint is abbreviated as (BC-2).
[0148]
"Acridic 47-712" 160 parts
[Dai Nippon Ink Chemical Co., Ltd.
Trade name of hydroxyl-containing acrylic resin
; Nonvolatile content = 50%]
33 parts of “Super Becamine L-117-60”
"Alpaste 1860YL" 23 parts
"First Gen Blue NK" 2nd part
[Dai Nippon Ink Chemical Co., Ltd.
Cyanine blue pigment trade name]
"Nature N-5225" 1 copy
[0149]
Reference example 7 (same as above)
The resin composition for paints in the form blended by the usual paint production method so as to have the following ratio is used as a diluent solvent [xylene / toluene / n-butyl acetate / methyl ethyl ketone = 30/30/20 / 20 (parts by weight)], Ford Cup NO. 4 was adjusted to a viscosity of 11 to 12 seconds to obtain a base coat paint. Hereinafter, this base coat paint is abbreviated as (BC-3).
[0150]
"Acridic 47-567" 100 copies
[Dainippon Ink Chemical Co., Ltd.
Of hydroxyl-containing acrylic resin
Product name; non-volatile content = 50%]
18 parts of "Bernock DN-950"
(Polyisocyanate made by the same company
Product name of non-volatile compounds;
75%)
60 copies of "Taipeke CR-93"
[Oxidized titanium produced by Ishihara Sangyo Co., Ltd.
Product name]
[0151]
Reference Example 8 [Preparation Example of Vinyl Polymer (F)]
In a reaction vessel similar to that of Reference Example 1, 500 parts of toluene and 50 parts of n-butyl acetate were added, and the temperature in the vessel was raised to 110 ° C.
[0152]
Then a monomer mixture consisting of 300 parts of styrene, 280 parts of trimethylsiloxyethyl methacrylate, 270 parts of IBMA, 50 parts of 3-methacryloyloxypropyltrimethoxysilane and 100 parts of lauryl methacrylate, and azoisobutyro A mixture of 50 parts of nitrile and 450 parts of n-butyl acetate was added dropwise over 5 hours,
[0153]
Further, by maintaining at the same temperature for 10 hours, a polymer having a non-volatile content of 50%, a number average molecular weight of 15,000, and an OH value generated from a siloxy group of 86 per non-volatile content Solution was obtained. Hereinafter, this vinyl polymer (F) solution is abbreviated as (F-1).
[0154]
Reference Example 9 (same as above)
In a reaction vessel similar to that of Reference Example 1, 500 parts of toluene and 50 parts of n-butyl acetate were added, and the temperature in the vessel was raised to 110 ° C.
[0155]
A monomer mixture consisting of 200 parts of styrene, 230 parts of trimethylsiloxyethyl methacrylate, 400 parts of n-butyl methacrylate, 150 parts of n-butyl acrylate, 50 parts of azoisobutyronitrile and n-acetate A mixture of 450 parts of butyl was added dropwise over 5 hours.
[0156]
Further, by maintaining at the same temperature for 10 hours, a polymer having a nonvolatile content of 50%, a number average molecular weight of 16,000, and an OH value generated from a siloxy group of 70 per nonvolatile component Solution was obtained. Hereinafter, this vinyl polymer (F) solution is abbreviated as (F-2).
[0157]
Reference Example 10 (same as above)
In a reaction vessel similar to that in Reference Example 1, 500 parts of xylene and 50 parts of n-butyl acetate were placed, and the temperature in the vessel was raised to 110 ° C.
[0158]
Next, 200 parts of styrene, “Placcel FM-1” (a compound obtained by adding 1 mol of ε-caprolactone to 2-hydroxyethyl methacrylate under the trade name made by the company), trimethylchlorosilane, A monomer mixture consisting of 290 parts of the reaction product, 300 parts of n-butyl methacrylate, 150 parts of n-butyl acrylate and 40 parts of acrylic acid, 50 parts of azoisobutyronitrile and n-butyl acetate A mixture of 500 parts of was added dropwise over 5 hours.
[0159]
Further, by maintaining at the same temperature for 10 hours, a polymer having a non-volatile content of 50%, a number average molecular weight of 14,000, and an OH number generated from a siloxy group of 66 per non-volatile content Solution was obtained. Hereinafter, this vinyl polymer (F) solution is abbreviated as (F-3).
[0160]
Reference Example 11 [Preparation Example of Curing Agent (G)]
In a reaction vessel similar to that of Reference Example 1, 500 parts of toluene, 50 parts of n-butyl acetate and 100 parts of maleic anhydride were placed, and the temperature in the vessel was raised to 110 ° C.
[0161]
Next, a monomer mixture consisting of 300 parts of styrene, 300 parts of n-butyl methacrylate and 300 parts of n-butyl acrylate, 50 parts of azoisobutyronitrile, tert-butyl peroctoate (tert-butyl peroxyate). A mixture of 50 parts of octate and 450 parts of n-butyl acetate was added dropwise over 5 hours.
[0162]
Further, by maintaining the same temperature for 10 hours, a polymer solution having a nonvolatile content of 50% and a number average molecular weight of 5,000 was obtained. Hereinafter, this solution is abbreviated as a curing agent (G-1).
[0163]
Reference Examples 12 to 15 (Preparation Examples of Clearcoat Paint)
Each of the vinyl polymers (F-1) to (F-3) obtained in Reference Examples 8 to 11, the curing agent (G-1), a commercially available polyisocyanate compound, an epoxy compound, and the like. And blended separately according to the blending ratio as shown in Table 1, and the solvent for dilution [xylene / toluene / n-butyl acetate / methyl ethyl ketone = 30/30/20/20 (parts by weight)] By diluting to spray viscosity, various clear coat paints were obtained.
[0164]
[Table 1]

[0165]
《Legs of Table 1》
(Note 1) "DN-990S" ... "Burnock DN-990S"
Abbreviation of [trade name of polyisocyanate compound manufactured by Dainippon Ink & Chemicals, Inc .; isocyanate content = 18.0%]
[0166]
(Note 2) GTGE: An abbreviation for glycerin triglycidyl ether, which is a compound having an epoxy equivalent of 145.
[0167]
(Note 3) TBACL ... Abbreviation for tetrabutylammonium chloride
[0168]
(Note 4) PTSI: Abbreviation for p-toluenesulfonyl isocyanate
[0169]
(Note 5) “Chinubin 900”: Trade name of UV absorbers manufactured by Ciba-Geigy, Switzerland
[0170]
(Note 6) “Sanol LS292”: trade name of light stabilizer manufactured by Sankyo Co., Ltd.
[0171]
[Table 2]

[0172]
Reference Example 16 (Preparation Example of Control Undercoat Paint)
90 parts of “Acridic A-801-P” [trade name of hydroxyl-containing acrylic resin manufactured by Dainippon Ink & Chemicals, Inc .; nonvolatile content = 50%] instead of copolymer (A-1) A control undercoat was prepared in the same manner as in Reference Example 3 except that the composition was changed to use. Hereinafter, this is abbreviated as an undercoat paint (RP-1).
[0173]
Reference Example 17 (Example of Preparation of Control Clearcoat Paint)
A control clear coat paint was prepared in the same manner as in Reference Example 13 except that the blending ratio was changed according to the following blending ratio. Hereinafter, this is abbreviated as a clear coat paint (RC-1).
[0174]
"Acridic A-345" 100 parts
[Dai Nippon Ink Chemical Co., Ltd.
Hydroxyl group-containing acrylic resin
Product name; non-volatile content = 55%]
40 units of “Super Becamine L-117-60”
"Nature N-5225" 1 copy
"Tinubin 900" 1 copy
"Sanol LS292" 1 part
[0175]
Examples 1-4 and Comparative Examples 1 and 2
On the pre-treated polypropylene-based resin coating material obtained in each reference example, using a paint based on conventional technology as a base coating, base coating, clear coating, and comparative coating Table 2 lists the specification of various conditions for coating and the results of the evaluation judgment test on the obtained coated plate.
[0176]
Here, the outline of the performance evaluation test shown in Table 2 is as follows.
[0177]
(1) Gloss
Measurements were made using a digital gonioglossmeter manufactured by Suga Test Instruments Co., Ltd.
[0178]
(2) Sharpness
The measurement was performed using a PGD clarity tester manufactured by Suga Test Instruments Co., Ltd.
[0179]
(3) Acid resistance
After a 0.2 milliliter liter of 5% sulfuric acid aqueous solution is placed on the coating surface and left for 30 minutes in an atmosphere at 70 ° C, the appearance of the coated film is visually evaluated for evaluation. did.
[0180]
(4) Pencil hardness
Using “Uni” [trade name of pencil manufactured by Mitsubishi Pencil Co., Ltd.], the conventional method was used.
[0181]
(5) Accelerated weather resistance
The appearance of the coating film after an accelerated exposure test for 1,000 hours using a Dew panel light control / weather meter was visually evaluated and judged.
[0182]
(6) Durable adhesion
After applying the cross-cut with a cutter / knife to the coating film after the accelerated weather resistance test described above, the so-called cellophane tape was peeled off, and the adhesion state of the coating film was visually evaluated and judged.
[0183]
[Table 3]

[0184]
[Table 4]

[0185]
《Legs of Table 2》
The symbols in the table have the following meanings, respectively.
[0186]
◎… very good
○… Good
△ ... Poor
×: Extremely bad
[0187]
[Table 5]

[0188]
[Table 6]

[0189]

[0190]
[Table 8]

[0191]
Thus, according to the method for forming a coating film according to the present invention, the products of the present invention according to Examples 1 to 4, respectively, according to the prior art, are also evident by comparison with Comparative Examples 1 and 2, respectively. Thus, in the case of the coating film forming method of the present invention, it is possible to form a coating film excellent in acid resistance, hardness, coating film appearance, etc. It will be easy to know that it is extremely practical for the use of polyolefin materials.
[0192]
【The invention's effect】
As described in detail above, according to the method for forming a coating film according to the present invention, it is possible to form a coating film excellent in acid resistance, hardness, coating film appearance and the like. The invention can provide a method for forming a coating film, which is extremely practical.

Claims (5)

  After applying the base coat to the polyolefin base material to form the base coat, apply the base coat paint on the surface of the base coat, and then apply the clear coat on the base coat. In the method of forming a coating film comprising applying a paint, each of the above-described undercoat paints includes a hydroxyl group-containing vinyl-modified chlorinated polyolefin (A) and a curing agent (B) having reactivity with the hydroxyl group, A vinyl polymer (C) having a hydroxyl group and / or a polyester resin having a hydroxyl group (in which a metallic powder and / or a coloring pigment is blended as the above-described base coat paint, using a paint contained as an essential film-forming component. D) and a curing agent (E) having reactivity with a hydroxyl group is used as an essential coating film forming component, and the above-described clearing agent is used. As a coating material for coating, a vinyl polymer (F) having at least two siloxy groups in one molecule, a curing agent (G) reactive with a hydroxyl group produced from the polymer (F), and a siloxy group A method for forming a coating film, comprising using a coating material containing the dissociation promoting catalyst (H) as an essential coating film forming component.   The method for forming a coating film according to claim 1, wherein the curing agent (B) having reactivity with a hydroxyl group is at least one compound selected from the group consisting of a polyisocyanate compound and an amino resin.   The method for forming a coating film according to claim 1, wherein the curing agent (E) having reactivity with a hydroxyl group is at least one compound selected from the group consisting of a polyisocyanate compound and an amino resin.   The coating film according to claim 1, wherein the vinyl polymer (F) has both a siloxy group for generating a hydroxyl group by hydrolysis and a hydrolyzable silyl group bonded to a carbon atom. Method.   The coating according to claim 1, wherein the curing agent (G) having reactivity with a hydroxyl group is at least one compound selected from the group consisting of a polyisocyanate compound, a carboxylic acid anhydride group-containing compound, and an epoxy compound. Method for forming a film.