JP3552466B2 - Method for forming coating film for automobile inner plate - Google Patents
Method for forming coating film for automobile inner plate Download PDFInfo
- Publication number
- JP3552466B2 JP3552466B2 JP15548797A JP15548797A JP3552466B2 JP 3552466 B2 JP3552466 B2 JP 3552466B2 JP 15548797 A JP15548797 A JP 15548797A JP 15548797 A JP15548797 A JP 15548797A JP 3552466 B2 JP3552466 B2 JP 3552466B2
- Authority
- JP
- Japan
- Prior art keywords
- coating
- inner plate
- clear
- curing
- coat
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Description
【０００１】
【発明の属する技術分野】
本発明は自動車内板用塗膜形成方法に関するものであり、特に当該内板部と外板部との境界部位における塗装仕上がり外観の向上を図る技術に関するものである。
【０００２】
【従来の技術】
従来、自動車車体表面に複層構造の塗膜を形成するにおいては、自動車車体表面に順次、下塗り塗膜層、中塗り塗膜層等のより下層側の塗膜層を形成した後、メタリック顔料や着色顔料を配合した熱硬化性樹脂塗料を上塗りベース塗料として塗装し、形成されたベースコート上部にウェットオンウェット方式によって、内板部には内板用上塗りクリア塗料を、また外板部には外板用上塗りクリア塗料を塗布し、しかる後、全体の塗膜を加熱硬化することよりなる２コート１ベーク方式の上塗り塗装方法が広く行われている。なお、この方法において、内板部と外板部との境界部位においては、前記内板用上塗りクリア塗料と前記外板用上塗りクリア塗料とがウェットオンウェット方式によって塗り重ねられている。
【０００３】
この方法によれば、内板表面は優れた仕上がり外観など高品質塗膜が得られるが、内板部と外板部との境界部位においては、内板用クリア塗料と外板用クリア塗料との混じり合いによる外観低下の問題点があった。
【０００４】
このような観点から、上記したような２コート１ベーク方式の上塗り塗装方法において、仕上がり外観の向上を図るために種々の提案がなされ、かつ実際の塗装ラインにおいて実施されている。これらは、ウェットオンウェット方式で塗装した場合に、内板部と外板部との境界部位における内板用クリア塗料と外板用クリア塗料との混じり合いを防止する手法に関するものであり、具体的には、両者間のなじみもしくは相互溶解性を小さくするため、下層に当たる塗膜中にセルロースアセテートブチレートを混入したり、下層をプレヒートし一定の不揮発分以上のものとしてから最外層となるクリア塗料を塗装する方法、両者の溶解性パラメーターの差を一定の幅以上にする方法等がある。
【０００５】
【発明が解決しようとする課題】
しかしながら、内板部と外板部との境界部位における塗装系において、これまで優れた仕上がり外観を得るため前記複層塗膜が具備すべき基本的特性については検討されたことがなかった。すなわち、複層塗膜は相互に溶解して均一化しない限り、塗装焼付け時に別々の硬化挙動を示すことは容易に理解できる。従って両者間で例えば硬化開始時間、硬化反応速度、焼付け時の粘度上昇速度、溶媒蒸発速度、硬化収縮による歪みの状態等が当然に異なり、その結果、複層塗膜全体の仕上がり外観がこれらの相違によって影響を受けることは明白である。
【０００６】
殊に、最近、クリアコートの厚膜化により仕上がり外観の向上を図ることが検討されているが、複層間の個々の単膜の硬化プロセスの違いを考慮しない塗装系をもってしては、大幅な仕上がり外観の向上は期待できないものであろう。
【０００７】
従って、本発明は、改良された自動車内板用塗膜形成方法を提供することを課題とするものである。本発明はまた、内板部と外板部との境界部位における塗装仕上がり外観の向上を図ることのできる自動車内板用塗膜形成方法を提供することを課題とするものである。本発明はさらに、自動車車体の内板部表面の塗装に用いられる２コート１ベーク方式の上塗り塗装で、かつ外板部との境界部位において内板用クリア塗料が外板用クリア塗料とウェットオンウェット方式で塗布される塗装方法において、使用される双方の塗料の基本的特性を調整することにより、この境界部位における塗装仕上がり外観の向上を図ることのできる自動車内板用塗膜形成方法を提供することを課題とするものである。
【０００８】
【課題を解決するための手段】
上記諸目的を解決する本発明は、（１）上塗りベース塗料を塗布した後、形成されたベースコート上部にウェットオンウェット方式によって、内板用上塗りクリア塗料を塗布し、しかる後に全体の塗膜を加熱硬化することよりなる２コート１ベーク方式の自動車内板用塗膜の形成方法であって、当該内板部の外板部との境界部位においては、前記内板用上塗りクリア塗料と外板用上塗りクリア塗料とがウェットオンウェット方式によって塗り重ねられるにおいて、前記加熱硬化に際する温度条件下における、内板用上塗りクリア塗料の単独の硬化開始時間をＴＩ（ ｉｎｔｅｒｉｏｒ ）、外板用上塗りクリア塗料の単独の硬化開始時間をＴＩ（ ｅｘｔｅｒｉｏｒ ）、内板用上塗りクリア塗料の単独の硬化飽和時間をＴＥ（ ｉｎｔｅｒｉｏｒ ）、外板用上塗りクリア塗料の単独の硬化飽和時間をＴＥ（ ｅｘｔｅｒｉｏｒ ）とするとき、前記ＴＩ（ ｉｎｔｅｒｉｏｒ ）が０．７分ないし８分の間、前記ＴＩ（ ｅｘｔｅｒｉｏｒ ）が０．８分ないし１０分の間にあり、かつ
２≧ＴＩ（ ｅｘｔｅｒｉｏｒ ）〔分〕−ＴＩ（ ｉｎｔｅｒｉｏｒ ）〔分〕≧０
ＴＥ（ ｅｘｔｅｒｉｏｒ ）〔分〕≧ＴＥ（ ｉｎｔｅｒｉｏｒ ）〔分〕
なる関係が満たされるように、前記内板用上塗りクリア塗料と前記外板用上塗りクリア塗料のそれぞれ有する硬化時間を調整することによって、前記境界部位における塗装仕上がり外観を向上させることを特徴とする自動車内板用塗膜形成方法である。
【０００９】
本発明はまた、（２）上塗りベース塗料を塗布した後、形成されたベースコート上部にウェットオンウェット方式によって、内板用上塗りクリア塗料を塗布し、しかる後に全体の塗膜を加熱硬化することよりなる２コート１ベーク方式の自動車内板用塗膜の形成方法であって、当該内板部の外板部との境界部位においては、前記内板用上塗りクリア塗料と外板用上塗りクリア塗料とがウェットオンウェット方式によって塗り重ねられるにおいて、前記内板用上塗りクリア塗料と前記外板用上塗りクリア塗料との硬化時間の調整を硬化剤で行い、前記内板用上塗りクリア塗料に配合される硬化剤の反応性が、相対的に、前記外板用上塗りクリア塗料に配合される硬化剤の反応性よりも高いものとすることによって、前記境界部位における塗装仕上がり外観を向上させることを特徴とする自動車内板用塗膜形成方法である。
【００１０】
本発明はさらに、（３）上塗りベース塗料を塗布した後、形成されたベースコート上部にウェットオンウェット方式によって、内板用上塗りクリア塗料を塗布し、しかる後に全体の塗膜を加熱硬化することよりなる２コート１ベーク方式の自動車内板用塗膜の形成方法であって、当該内板部の外板部との境界部位においては、前記内板用上塗りクリア塗料と外板用上塗りクリア塗料とがウェットオンウェット方式によって塗り重ねられるにおいて、前記加熱硬化に際する温度条件下における、内板用上塗りクリア塗料の単独の硬化開始時間をＴＩ（ ｉｎｔｅｒｉｏｒ ）、外板用上塗りクリア塗料の単独の硬化開始時間をＴＩ（ ｅｘｔｅｒｉｏｒ ）、内板用上塗りクリア塗料の単独の硬化飽和時間をＴＥ（ ｉｎｔｅｒｉｏｒ ）、外板用上塗りクリア塗料の単独の硬化飽和時間をＴＥ（ ｅｘｔｅｒｉｏｒ ）とするとき、前記ＴＩ（ ｉｎｔｅｒｉｏｒ ）が０．７分ないし８分の間、前記ＴＩ（ ｅｘｔｅｒｉｏｒ ）が０．８分ないし１０分の間にあり、かつ
２≧ＴＩ（ ｅｘｔｅｒｉｏｒ ）〔分〕−ＴＩ（ ｉｎｔｅｒｉｏｒ ）〔分〕≧０
ＴＥ（ ｅｘｔｅｒｉｏｒ ）〔分〕≧ＴＥ（ ｉｎｔｅｒｉｏｒ ）〔分〕
なる関係が満たされるように、前記内板用上塗りクリア塗料と前記外板用上塗りクリア塗料のそれぞれ有する硬化時間の調整を硬化剤で行い、前記内板用上塗りクリア塗料に配合される硬化剤の反応性が、相対的に、前記外板用上塗りクリア塗料に配合される硬化剤の反応性よりも高いものとすることによって、前記境界部位における塗装仕上がり外観を向上させることを特徴とする自動車内板用塗膜形成方法である。
【００１１】
本発明はさらに、（４）前記内板用上塗りクリア塗料と前記外板用上塗りクリア塗料との硬化時間の調整を、酸触媒で行うことを特徴とする上記（１）記載の自動車内板用塗膜形成方法を示すものである。
【００１２】
本発明はさらにまた、（５）前記硬化剤はメラミン樹脂であり、前記内板用上塗りクリア塗料と前記外板用上塗りクリア塗料との硬化時間の調整を、前記メラミン樹脂のアルキル化度を変えることで行うことを特徴とする（１）記載の自動車内板用塗膜形成方法を示すものである。
【００１３】
【発明の実施の形態】
以下、本発明の作用を具体的な実施態様と共により詳細に説明する。
【００１４】
本発明の自動車内板用塗膜形成方法は、メタリック顔料や着色顔料を配合した熱硬化性樹脂塗料を上塗りベースコートとして塗装し、次いで、このベースコート上部にウェットオンウェット方式によって、内板用熱硬化性樹脂クリア塗料を上塗りクリアコート（トップコート）として塗布し、しかる後に全体の塗膜を加熱硬化することよりなる２コート１ベーク方式の自動車内板用塗膜の形成方法であって、かつ当該内板部の外板部との境界部位においては、前記内板用上塗りクリアコートと前記外板用上塗りクリアコートとがウェットオンウェット方式によって塗り重ねられ複層塗膜を形成するものである。
【００１５】
図１は、本発明に係る自動車内板用塗膜形成方法によって、形成される塗膜の複層構造の例を模式的に示すものである。
【００１６】
図１に示す実施態様においては、自動車車体表面１上に、順に下塗りコート２、中塗りコート３、および上塗りベースコート４が形成されており、さらにこの上塗りベースコート４の上部には、自動車車体１の内板部１ａでは、トップコートとして内板用上塗りクリアコート５が、また、自動車車体１の外板部１ｂでは、トップコートとして外板用上塗りクリアコート６が形成されているが、内板部１ａと外板部１ｂとの境界１ｃ部位においては、内板用上塗りクリアコート５と外板用上塗りクリアコート６とが塗り重ねられた状態とされている。
【００１７】
このような塗膜構成は、上塗りベースコート４が形成されたら、まず、内板部１ａ側にウェットオンウェット方式によって、内板用熱硬化性樹脂クリア塗料を塗装して内板用上塗りクリアコート５を形成し、次いで、外板部１ｂ側に同様にウェットオンウェット方式によって、外板用熱硬化性樹脂クリア塗料を塗装して外板用上塗りクリアコート６を形成することで得られるものである。ここで、双方のクリア塗料は、クリア塗料の塗り残し部位が生じないように、いずれもある程度オーバーレンジで塗装されるため、境界１ｃ部位では、上塗りベースコート４の上にまずウェットオンウェットにて内板用上塗りクリアコート５が、さらにこの上にウェットオンウェットにて外板用上塗りクリアコート６が積層されるものである。
【００１８】
本発明において、上塗りベースコート４よりも下層の塗膜構成としては、特に限定されるものではなく、図１に示す実施態様におけるような構成以外にも、例えば、下塗りコートおよび／または中塗りコートを省略したような構成、中塗りコートを二層とする構成など、各種の態様を採択することができる。また、上塗りベースコートとしても、図１に示すような構成に何ら限定されるものではなく、例えば、メタリック塗装、パール塗装等において見られるように機能の異なる２ないしそれ以上の層より構成することも可能である。さらに、内板用上塗りクリアコート５と外板用上塗りクリアコート６との塗装順番を逆として、境界１ｃ部位で、上塗りベースコート４の上に外板用上塗りクリアコート６、内板用上塗りクリアコート５の順で積層されるような態様も可能であるが、内板部１ａよりも外板部１ｂの方が、塗装の性能、外観品質等が重要視されるものであるため、一般的には、図１に示すように内板用上塗りクリアコート５を先に塗装することが望ましい。
【００１９】
また、本発明において内板用上塗りクリアコート５および外板用上塗りクリアコート６を形成するためにそれぞれ用いられる熱硬化性樹脂クリア塗料のタイプとしては、特に限定されるものではなく、例えば、メラミン−アルキド樹脂塗料等のアミノ−アルキド系樹脂塗料、アクリル−メラミン系樹脂塗料等の熱硬化性アクリル樹脂塗料、ウレタン系樹脂塗料、含フッ素樹脂系塗料などといった従来公知の各種のものを用いることができ、また両者はそれぞれ同じタイプのものであっても異なるタイプのものであっても良い。、
一般に外板用上塗りクリアコートには、クリアコート本来の透明性、光沢性に加えて、耐候性、耐衝撃性、耐薬品性、耐熱性という性能が要求され、一方内板用上塗りクリアコートには、透明性、光沢性という一部外板と同等の性能が要求されるため、それぞれに使用されるクリア塗料は、大別すると同じタイプ、例えば、熱硬化性アクリル樹脂系塗料に分類されるものであっても、これらの要求性能を得る上で、基体樹脂の分子量、基体樹脂と架橋樹脂との配合比、変性樹脂の有無と種類、添加剤の有無と種類等を適宜調整するため、その組成は互いに異なるものであり、このような組成の違いから、例えば硬化開始時間、硬化速度、焼き付け時の粘度上昇速度、溶媒蒸発速度、硬化収縮によるひずみの状態などといった硬化特性が、
当然に相違してくる。本発明においては、ある同一加熱硬化温度、すなわち、上塗り塗料の焼き付け時に適用される温度条件において、内板用熱硬化性樹脂クリア塗料の発揮する硬化特性と、外板用熱硬化性樹脂クリア塗料が発揮する硬化特性とが、所定の関係を満たすように、予め、内板用熱硬化性樹脂クリア塗料および／または外板用熱硬化性樹脂クリア塗料の組成を調整する、ないしは両者の組合せを適当なものとする。これによって、前記境界部位における塗装仕上がり外観を向上させるものである。
【００２０】
具体的な調整方法としては、特に限定されるものではないが、上塗り塗装の加熱硬化に際する温度条件下における、内板用熱硬化性樹脂クリア塗料の単独の硬化開始時間をＴＩ（ｉｎｔｅｒｉｏｒ）、外板用熱硬化性樹脂クリア塗料の単独の硬化開始時間をＴＩ（ｅｘｔｅｒｉｏｒ）、内板用熱硬化性樹脂クリア塗料の単独の硬化飽和時間をＴＥ（ｉｎｔｅｒｉｏｒ）、外板用熱硬化性樹脂クリア塗料の単独の硬化飽和時間をＴＥ（ｅｘｔｅｒｉｏｒ）とするとき、
２≧ＴＩ（ｅｘｔｅｒｉｏｒ）−ＴＩ（ｉｎｔｅｒｉｏｒ）≧０、かつ
ＴＥ（ｅｘｔｅｒｉｏｒ）≧ＴＥ（ｉｎｔｅｒｉｏｒ）
なる関係が満たされるように、前記内板用熱硬化性樹脂クリア塗料と前記外板用熱硬化性樹脂クリア塗料のそれぞれ有する硬化時間を調整することが望ましく、これにより、複層塗膜に形成した時、平滑な肌を持つ高仕上がり外観が得られる。
【００２１】
これに反し、ＴＩ（ｅｘｔｅｒｉｏｒ）−ＴＩ（ｉｎｔｅｒｉｏｒ）＞２の場合は、外板部との境界部位にて、外板用上塗りクリア塗料の硬化開始前に、内板用上塗りクリア塗料の硬化反応が極端に速く開始され、ウェットオンウェット面の接着反応が生じにくくなり、界面密着力が低下する。またＴＩ（ｅｘｔｅｒｉｏｒ）−ＴＩ（ｉｎｔｅｒｉｏｒ）＜０の場合は、外板部との境界部位にて、内板用上塗りクリア塗料の硬化開始前に、外板用上塗りクリア塗料の硬化反応が速く開始され、収縮ひずみが発生する。この時内板用上塗りクリア塗料は今だ十分に硬化反応していないため外板用上塗りクリア塗料の収縮ひずみに伴ってひきずられ、複層塗膜全体として平滑性の劣る結果となるものである。さらに、ＴＥ（ｅｘｔｅｒｉｏｒ）＜ＴＥ（ｉｎｔｅｒｉｏｒ）の場合には、外板用上塗りクリア塗料の硬化がほぼ完了しても、内板用上塗りクリア塗料が今だ十分に硬化していないこととなり、透明性、光沢性の劣る結果となるためである。
【００２２】
なお、本明細書において述べる硬化開始時間ＴＩおよび硬化飽和時間ＴＥの測定は、ＤＳＡ法（Ｄｙｎａｍｉｃ Ｓｐｒｉｎｇ Ａｎａｌｙｓｉｓ）による動的粘弾性測定によって行ったものである。
【００２３】
すなわち、これらの測定においては、０．４０ｍｍ径の銅線で、内径約３．０ｍｍ、巻き数３０回のスプリングを作製し、試料支持体とした。前記支持体に塗料を０．０１ｇ均一に塗布し、減圧乾燥させた後測定に供した。実際の塗膜の硬化過程は溶剤を含有した状態であるが、その時は塗装後焼き付け炉に入れる直前の塗膜の不揮発分と同一とした塗料を試料とするだけでよい。ここでは不揮発分が約１００％の試料を調製し、その硬化開始時間をもって代表させた。
【００２４】
動的粘弾性測定には、強制伸縮振動型動的粘弾性測定装置（バイブロンＤＤＶ−ＩＩ型、東洋ボールドウィン（株）製）を用い、周波数１１Ｈｚ、温度一定（１４０℃±５℃）の条件とした。試料を迅速に装着した時点をＴ０とし、相対弾性率を経時的に測定し、図２に示すように、相対弾性率を縦軸に、時間を横軸にプロットし、相対弾性率が急激に立ち上がり直線状に増加していく過程の部分の延長線と横軸との交差点を硬化開始時間ＴＩとして求めた。また相対弾性率の直線状に増加していく過程の延長線と相対弾性率の飽和値の交差点を硬化飽和時間ＴＥとして求めた。
【００２５】
本発明においては、さらに前記ＴＩ（ｉｎｔｅｒｉｏｒ）が０．７分ないし８分の間、前記ＴＩ（ｅｘｔｅｒｉｏｒ）が０．８分ないし１０分の間にあることが望ましく、使用される双方のクリア塗料が、このような硬化開始時間を有するものであれば、焼き付け処理が比較的短時間で行い得る上に、加熱硬化反応の進行の程度の制御が容易で、オーバーベークあるいは焼甘といった不具合を生じにくいためである。
【００２６】
上記したような各クリア塗料の硬化時間（硬化開始時間および硬化飽和時間）の調整は、塗料組成中に配合される硬化剤や添加剤によって行うことができる。
【００２７】
硬化剤は、架橋樹脂ないし架橋剤とも称されるものであって、クリア塗料のタイプに応じて種々のものが用いられるが、例えば多価イソシアネートおよびアミノプラスト等が含まれる。アミノプラストとしては、尿素、チオ尿素、メラミン、ペンゾグアナミン等とホルムアルデヒドとの縮合物や、これらの縮合物の低級アルキル（Ｃ１〜Ｃ４）エーテル化物が含まれる。このうち特にメチロール下の一部または全部がブタノールによってエーテル化されたメラミン／ホルムアルデヒド縮合物が好ましい。硬化時間の調整は、例えば、双方のクリア塗料に配合される硬化剤の反応度を変える、例えば硬化剤がメラミン樹脂である場合そのアルキル化度を変えたり、あるいは添加量を変えたりすることで行うことができる。
【００２８】
硬化時間の調整を塗料組成中に配合される硬化剤で行う場合、前記内板用熱硬化性樹脂クリア塗料に配合される硬化剤の反応性が、相対的に、前記外板用熱硬化性樹脂クリア塗料に配合される硬化剤の反応性よりも高いものとすれば、概して、上記のごとき所定の関係を満たすことが可能となる。
【００２９】
添加剤による硬化時間の調整は、硬化促進触媒および／または硬化遅延剤の添加によって行われる。
【００３０】
例えば、ポリオールと低級アルキルエーテル化メラミン／ホルムアルデヒド縮合物との間で硬化反応が行われる場合、硬化促進にはｐ−トルエンスルホン酸、ドデシルベンゼンスルホン酸、ジノニルナフタレンスルホン酸およびそれらの混合物のようなスルホン酸類、およびアルキルホスフェートなどが使用可能である。これらの硬化促進剤はあまり多量に使用すると塗膜の耐水性を低下させるために、塗料固形分１００重量部当たり、一般に５重量部以下とすることが望ましい。またこの系に使用される硬化遅延剤としては、塗装時において揮発せず、焼き付け硬化時に揮散するアミン類が好ましい。その例としては、ジエチルアミン、トリエチルアミン、ｎ−ブチルアミン、ジ−ｎ−ブチルアミン、トリ−ｎ−ブチルアミン、イソブチルアミン、ジイソブチルアミン、シクロヘキシルアミン、モノエタノールアミン、ジエチルエタノールアミン等が挙げられる。硬化遅延剤は、添加量があまり多量であると必要な硬化が得られなくなる虞れが高いので、塗料固形分１００重量部当たり、一般に５重量部以下とすることが望ましい。
【００３１】
またポリオールと多価イソシアネートとの間で硬化反応が行われる場合、硬化促進剤としては、前記の酸またはアミンが使用可能である。またアミン塩やアンモニウム塩等も硬化時間の調整に適当な添加剤である。
【００３２】
【実施例】
以下、本発明を実施例によりさらに具体的に説明する。
【００３３】
なお、以下において「部」は特にことわらない限り、「重量部」を意味する。
【００３４】
合成例１
撹拌器、温度制御装置、還流冷却器を備えた反応容器に、キシレン８０部、メチルイソブチルケトン１０部を仕込んだ。次いでこの反応容器に、以下に示す組成を有する重合性組成物のうち２０部を加え、撹拌しながら加熱して温度を上昇させた。還流しながら重合性組成物の残りの８１．５部を３時間かけて滴下し、次いでアゾビスイソブチロニトリル０．３部とキシロール１０部からなる溶液を３０分間かけて滴下した。反応溶液をさらに２時間撹拌還流させて重合率を上昇させた後、反応を終了させ不揮発分５０％、数平均分子量（Ｍｎ）１８０００のアクリル樹脂ワニス（１）を得た。
【００３５】
合成例１と同様の反応容器に、キシレン５７部、ｎ−ブタノール６部を仕込み、次いで以下に示す組成を有する重合性組成物うち２０部を加え、撹拌しながら加熱して温度を上昇させた。還流しながら重合性組成物の残りの８４部を２時間かけて滴下し、次いでアゾビスイソブチロニトリル０．５部とキシレン２３部、ｎ−ブタノール１４部からなる溶液を２０分間かけて滴下した。反応溶液をさらに２時間撹拌還流した後、反応を終了させ不揮発分５０％、数平均分子量（Ｍｎ）３４００のアクリル樹脂ワニス（２）を得た。
【００３６】
合成例３
ステンレス容器に下記組成の材料を秤量して収容し、実験用撹拌器で撹拌して内板用上塗りクリア塗料（１）を調製した。なお、このようにして調製した内板用上塗りクリア塗料（１）の硬化開始時間ＴＩ（ｉｎｔｅｒｉｏｒ）および硬化飽和時間をＴＥ（ｉｎｔｅｒｉｏｒ）を上記に述べたような方法によって測定したところ、ＴＩ（ｉｎｔｅｒｉｏｒ）が０．７分、ＴＥ（ｉｎｔｅｒｉｏｒ）が１．０分であった。
【００３７】
ステンレス容器に下記組成の材料を秤量して収容し、実験用撹拌器で撹拌して内板用上塗りクリア塗料（２）を調製した。なお、このようにして調製した内板用上塗りクリア塗料（２）の硬化開始時間ＴＩ（ｉｎｔｅｒｉｏｒ）および硬化飽和時間をＴＥ（ｉｎｔｅｒｉｏｒ）を上記に述べたような方法によって測定したところ、ＴＩ（ｉｎｔｅｒｉｏｒ）が０．８分、ＴＥ（ｉｎｔｅｒｉｏｒ）が１．４分であった。
【００３８】
ステンレス容器に下記組成の材料を秤量して収容し、実験用撹拌器で撹拌して内板用上塗りクリア塗料（３）を調製した。なお、このようにして調製した内板用上塗りクリア塗料（３）の硬化開始時間ＴＩ（ｉｎｔｅｒｉｏｒ）および硬化飽和時間をＴＥ（ｉｎｔｅｒｉｏｒ）を上記に述べたような方法によって測定したところ、ＴＩ（ｉｎｔｅｒｉｏｒ）が８．０分、ＴＥ（ｉｎｔｅｒｉｏｒ）が１３．１分であった。
【００３９】
ステンレス容器に下記組成の材料を秤量して収容し、実験用撹拌器で撹拌して内板用上塗りクリア塗料（４）を調製した。なお、このようにして調製した内板用上塗りクリア塗料（４）の硬化開始時間ＴＩ（ｉｎｔｅｒｉｏｒ）および硬化飽和時間をＴＥ（ｉｎｔｅｒｉｏｒ）を上記に述べたような方法によって測定したところ、ＴＩ（ｉｎｔｅｒｉｏｒ）が１０．０分、ＴＥ（ｉｎｔｅｒｉｏｒ）が１９．５分であった。
【００４０】
ステンレス容器に下記組成の材料を秤量して収容し、実験用撹拌器で撹拌して外板用上塗りクリア塗料（１）を調製した。なお、このようにして調製した外板用上塗りクリア塗料（１）の硬化開始時間ＴＩ（ｅｘｔｅｒｉｏｒ）および硬化飽和時間をＴＥ（ｅｘｔｅｒｉｏｒ）を上記に述べたような方法によって測定したところ、ＴＩ（ｅｘｔｅｒｉｏｒ）が２．７分、ＴＥ（ｅｘｔｅｒｉｏｒ）が６．３分であった。
【００４１】
ステンレス容器に下記組成の材料を秤量して収容し、実験用撹拌器で撹拌して外板用上塗りクリア塗料（２）を調製した。なお、このようにして調製した外板用上塗りクリア塗料（２）の硬化開始時間ＴＩ（ｅｘｔｅｒｉｏｒ）および硬化飽和時間をＴＥ（ｅｘｔｅｒｉｏｒ）を上記に述べたような方法によって測定したところ、ＴＩ（ｅｘｔｅｒｉｏｒ）が０．８分、ＴＥ（ｅｘｔｅｒｉｏｒ）が１．４分であった。
【００４２】
ステンレス容器に下記組成の材料を秤量して収容し、実験用撹拌器で撹拌して外板用上塗りクリア塗料（３）を調製した。なお、このようにして調製した外板用上塗りクリア塗料（３）の硬化開始時間ＴＩ（ｅｘｔｅｒｉｏｒ）および硬化飽和時間をＴＥ（ｅｘｔｅｒｉｏｒ）を上記に述べたような方法によって測定したところ、ＴＩ（ｅｘｔｅｒｉｏｒ）が３．６分、ＴＥ（ｅｘｔｅｒｉｏｒ）が９．４分であった。
【００４３】
ステンレス容器に下記組成の材料を秤量して収容し、実験用撹拌器で撹拌して外板用上塗りクリア塗料（４）を調製した。なお、このようにして調製した外板用上塗りクリア塗料（４）の硬化開始時間ＴＩ（ｅｘｔｅｒｉｏｒ）および硬化飽和時間をＴＥ（ｅｘｔｅｒｉｏｒ）を上記に述べたような方法によって測定したところ、ＴＩ（ｅｘｔｅｒｉｏｒ）が０．８分、ＴＥ（ｅｘｔｅｒｉｏｒ）が１．１分であった。
【００４４】
ステンレス容器に下記組成の材料を秤量して収容し、実験用撹拌器で撹拌して外板用上塗りクリア塗料（５）を調製した。なお、このようにして調製した外板用上塗りクリア塗料（５）の硬化開始時間ＴＩ（ｅｘｔｅｒｉｏｒ）および硬化飽和時間をＴＥ（ｅｘｔｅｒｉｏｒ）を上記に述べたような方法によって測定したところ、ＴＩ（ｅｘｔｅｒｉｏｒ）が１０．０分、ＴＥ（ｅｘｔｅｒｉｏｒ）が２１．７分であった。
【００４５】
ステンレス容器に下記組成の材料を秤量して収容し、実験用撹拌器で撹拌して外板用上塗りクリア塗料（６）を調製した。なお、このようにして調製した外板用上塗りクリア塗料（６）の硬化開始時間ＴＩ（ｅｘｔｅｒｉｏｒ）および硬化飽和時間をＴＥ（ｅｘｔｅｒｉｏｒ）を上記に述べたような方法によって測定したところ、ＴＩ（ｅｘｔｅｒｉｏｒ）が１２．２分、ＴＥ（ｅｘｔｅｒｉｏｒ）が２５．２分であった。
【００４６】
ステンレス容器に下記組成の材料を秤量して収容し、実験用撹拌器で撹拌して外板用上塗りクリア塗料（７）を調製した。なお、このようにして調製した外板用上塗りクリア塗料（７）の硬化開始時間をＴＩ（ｅｘｔｅｒｉｏｒ）および硬化飽和時間をＴＥ（ｅｘｔｅｒｉｏｒ）を上記に述べたような方法によって測定したところ、ＴＩ（ｅｘｔｅｒｉｏｒ）が８．０分、ＴＥ（ｅｘｔｅｒｉｏｒ）が１３．２分であった。
【００４７】
１５０×７０×０．８ｍｍの鋼製試験片に、下塗り塗料としてカチオン電着塗料（パワートップＰＵ−５０、日本ペイント（株）製）を２５μｍの膜厚で塗装し、加熱硬化後、中塗り塗料としてオルガＳ−９０シーラー（日本ペイント（株）製）を４０μｍの膜厚で塗装し加熱硬化させた。続いて上塗りベース塗料として、アクリル樹脂系ベースコート（スーパーラックＭ−８０ホワイト、日本ペイント（株）製）を２０μｍの膜厚で塗装し、１８０秒間のセッティングの後、ウェットオンウェットにて、上記合成例３で得られた内板用上塗りクリア塗料（１）を試験片のほぼ半分の領域において３５μｍの膜厚で塗装し、１８０秒間のセッティングの後、さらに上記合成例７で得られた外板用上塗りクリア塗料（１）を、ウェットオンウェットにて、試験片の残りの半分の領域に塗装したが、内板用上塗りクリア塗料の塗装領域と外板用上塗りクリア塗料の塗装領域との境界部位においては双方の塗料が一部塗り重なるように塗装した。最後に上塗り塗膜全体を１４０℃で２０分間焼き付けて、加熱硬化させた。
【００４８】
このようにして複層塗膜を形成された試験片について、内板用上塗りクリア塗料と外板用上塗りクリア塗料の塗り重ねられた境界部位おける塗膜性能（目視光沢、ＮＩＤ値、平滑性、熱サイクル性、熱衝撃性）を評価した。得られた結果を表１に示す。
【００４９】
実施例２
実施例１において、外板用上塗りクリア塗料（１）に代えて、合成例８で得られた外板用上塗りクリア塗料（２）を用いた以外は実施例１と同様にして塗装を行い、得られた複層塗膜の塗膜性能を同様に評価した。得られた結果を表１に示す。
【００５０】
実施例３
実施例１において、内板用上塗りクリア塗料（１）に代えて、合成例４で得られた内板用上塗りクリア塗料（２）を、また外板用上塗りクリア塗料（１）に代えて、合成例８で得られた外板用上塗りクリア塗料（２）を用いた以外は実施例１と同様にして塗装を行い、得られた複層塗膜の塗膜性能を同様に評価した。得られた結果を表１に示す。
【００５１】
実施例４
実施例１において、内板用上塗りクリア塗料（１）に代えて、合成例５で得られた内板用上塗りクリア塗料（３）を、また外板用上塗りクリア塗料（１）に代えて、合成例１１で得られた外板用上塗りクリア塗料（５）を用いた以外は実施例１と同様にして塗装を行い、得られた複層塗膜の塗膜性能を同様に評価した。得られた結果を表１に示す。
【００５２】
実施例５
実施例１において、内板用上塗りクリア塗料（１）に代えて、合成例５で得られた内板用上塗りクリア塗料（３）を、また外板用上塗りクリア塗料（１）に代えて、合成例１２で得られた外板用上塗りクリア塗料（６）を用いた以外は実施例１と同様にして塗装を行い、得られた複層塗膜の塗膜性能を同様に評価した。得られた結果を表１に示す。
【００５３】
比較例１
実施例１において、外板用上塗りクリア塗料（１）に代えて、合成例９で得られた外板用上塗りクリア塗料（３）を用いた以外は実施例１と同様にして塗装を行い、得られた複層塗膜の塗膜性能を同様に評価した。得られた結果を表１に示す。
【００５４】
比較例２
実施例１において、内板用上塗りクリア塗料（１）に代えて、合成例４で得られた内板用上塗りクリア塗料（２）を、また外板用上塗りクリア塗料（１）に代えて、合成例１０で得られた外板用上塗りクリア塗料（４）を用いた以外は実施例１と同様にして塗装を行い、得られた複層塗膜の塗膜性能を同様に評価した。得られた結果を表１に示す。
【００５５】
比較例３
実施例１において、内板用上塗りクリア塗料（１）に代えて、合成例５で得られた内板用上塗りクリア塗料（３）を、また外板用上塗りクリア塗料（１）に代えて、合成例１３で得られた外板用上塗りクリア塗料（７）を用いた以外は実施例１と同様にして塗装を行い、得られた複層塗膜の塗膜性能を同様に評価した。得られた結果を表１に示す。
【００５６】
比較例４
実施例１において、内板用上塗りクリア塗料（１）に代えて、合成例４で得られた内板用上塗りクリア塗料（２）を、また外板用上塗りクリア塗料（１）に代えて、合成例１０で得られた外板用上塗りクリア塗料（４）を用いた以外は実施例１と同様にして塗装を行い、得られた複層塗膜の塗膜性能を同様に評価した。得られた結果を表１に示す。
【００５７】
比較例５
実施例１において、内板用上塗りクリア塗料（１）に代えて、合成例６で得られた内板用上塗りクリア塗料（４）を、また外板用上塗りクリア塗料（１）に代えて、合成例１２で得られた外板用上塗りクリア塗料（６）を用いた以外は実施例１と同様にして塗装を行い、得られた複層塗膜の塗膜性能を同様に評価した。得られた結果を表１に示す。
【００５８】
なお、各塗膜性能の評価は、以下のようにして行った。
【００５９】
目視光沢
塗膜外表面の光沢を自然光の下で目視により観察し、○：光沢極めて良好、△：光沢良好、×：光沢不良という３段階に評価分けした。
【００６０】
ＮＩＤ値
塗膜の平滑性を調べるため、試験片上を鮮映性測定機（ＮＩＤ計）によって画像解析を行い、ＰＧＤ対応値を読み取った。
【００６１】
平滑性
塗膜の平滑性を目視により観察し、○：平滑性極めて良好、△：平滑性良好、×：平滑性不良という３段階に評価分けした。
【００６２】
熱サイクル性
９０℃、４時間→２０℃、０．５時間→−４０℃、１．５時間→２０℃、０．５時間→７５℃、９５％ＲＨ、３時間→２０℃、０．５時間→４０℃、１．５時間→２０℃、０．５時間のサイクルを１サイクルとし、１０サイクル負荷後の塗膜ワレ等の外観異常の有無を目視により観察した。
【００６３】
耐衝撃性
衝撃変形試験器（デュポン式） ＪＩＳ Ｋ５４００ ８．３．２に規定される装置を用い、塗膜ワレに至る球体衝突のおもり高さを測定した。
【００６４】
【表１】
【発明の効果】
以上述べたように本発明によれば、内板用上塗りクリア塗料と外板用上塗りクリア塗料とがそれぞれ有する硬化時間を予め所定のものに調整することによって、これらのクリア塗料がウェットオンウェットにて塗り重ねられる内板部と外板部との境界部位における塗装仕上がり外観を大きく向上させることができるものである。
【図面の簡単な説明】
【図１】本発明に係る自動車内板用塗膜形成方法によって、形成される塗膜の複層構造の例を模式的に示すものである。
【図２】塗料の加熱焼き付け時における塗料の相対弾性率と経過時間とから塗料の硬化開始時間および硬化飽和時間を決定する方法を説明するグラフである。
【符号の説明】
１…自動車車体表面、
１ａ…自動車車体の内板部、
１ｂ…自動車車体の外板部、
１ｃ…内板部と外板部の境界、
２…下塗りコート、
３…中塗りコート、
４…上塗りベースコート、
５…内板用上塗りクリアコート、
６…外板用上塗りクリアコート。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for forming a coating film for an automobile inner plate, and more particularly to a technique for improving the appearance of a finished paint at a boundary portion between the inner plate portion and the outer plate portion.
[0002]
[Prior art]
Conventionally, when a coating film having a multilayer structure is formed on the surface of an automobile body, a lower coating layer such as an undercoat layer or an intermediate coating layer is sequentially formed on the surface of the automobile body, and then a metallic pigment is formed. And a thermosetting resin paint containing a coloring pigment as a top coat base paint.The top coat formed is wet-on-wet on the base coat, the top coat clear paint for the inner plate on the inner plate, and the outer plate on the outer plate. 2. Description of the Related Art A two-coat, one-bake type top coating method comprising applying a top coating clear coating for an outer panel and then heat-curing the entire coating film has been widely performed. In this method, at the boundary between the inner plate portion and the outer plate portion, the top coat clear paint for the inner plate and the top coat clear paint for the outer plate are overlaid by a wet-on-wet method.
[0003]
According to this method, a high quality coating film such as an excellent finished appearance is obtained on the inner plate surface, but at a boundary portion between the inner plate portion and the outer plate portion, the inner plate clear paint and the outer plate clear paint are used. There was a problem that the appearance was deteriorated due to the mixture of these.
[0004]
From such a viewpoint, various proposals have been made in order to improve the finished appearance in the above-mentioned two-coat, one-bake type top-coating method, and the method has been implemented in an actual coating line. These are related to a method of preventing mixing of the clear paint for the inner plate and the clear paint for the outer plate at the boundary portion between the inner plate portion and the outer plate portion when coated by a wet-on-wet method, and Specifically, in order to reduce the adaptability or mutual solubility between the two, cellulose acetate butyrate is mixed in the lower layer coating, or the lower layer is preheated to a certain non-volatile content or more and then becomes the outermost layer. There are a method of applying a paint, a method of making the difference between the solubility parameters of the two a certain width or more, and the like.
[0005]
[Problems to be solved by the invention]
However, in the coating system at the boundary between the inner plate portion and the outer plate portion, the basic characteristics that the multilayer coating film should have in order to obtain an excellent finished appearance have not been studied. That is, it can be easily understood that the multilayer coating films exhibit different curing behaviors at the time of coating baking unless they are dissolved and homogenized. Therefore, for example, the curing start time, the curing reaction rate, the rate of increase in viscosity during baking, the solvent evaporation rate, the state of distortion due to curing shrinkage, and the like are naturally different between the two, and as a result, the finished appearance of the entire multilayer coating film is It is clear that they are affected by the differences.
[0006]
In particular, recently, it has been considered to improve the finished appearance by increasing the thickness of the clear coat, but with a coating system that does not consider the difference in the curing process of individual single films between multiple layers, there is a significant An improvement in the finished appearance would not be expected.
[0007]
Therefore, an object of the present invention is to provide an improved method for forming a coating film for an automobile inner plate. Another object of the present invention is to provide a method for forming a coating film for an automobile inner plate, which can improve the finish appearance of the coating at the boundary between the inner plate portion and the outer plate portion. The present invention further provides a two-coat, one-bake top coating used for painting the surface of the inner plate of an automobile body, and wherein the clear paint for the inner plate is wet-on with the clear paint for the outer plate at the boundary with the outer plate. In a coating method applied by a wet method, a method for forming a coating film for an automobile inner plate that can improve the finish appearance at the boundary by adjusting the basic characteristics of both the coating materials used is provided. The task is to do so.
[0008]
[Means for Solving the Problems]
The present invention for solving the above-mentioned objects is as follows. (1) After applying a topcoat base paint, a topcoat clear paint for an inner plate is applied on the formed basecoat by a wet-on-wet method, and then the entire coating film is applied. A method for forming a two-coat, one-baked automotive inner-plate coating film by heating and curing, wherein at the boundary between the inner-plate part and the outer-plate part, the inner-plate top-coating clear paint and the outer-plate When the top coat clear paint is applied over the wet-on-wet method,Under the temperature conditions at the time of the heat curing, the single curing start time of the top clear coating material for the inner plate is defined as TI ( interior ), The independent curing start time of the topcoat clear paint for the outer exterior ), And the curing saturation time of the overcoat clear paint for the inner plate alone is TE ( interior ), The sole curing saturation time of the top clear coating for exterior exterior ), The TI ( interior ) For 0.7 to 8 minutes. exterior ) Is between 0.8 and 10 minutes, and
2 ≧ TI ( exterior ) [Min]-TI ( interior ) [Minutes] ≧ 0
TE ( exterior ) [Min] ≧ TE ( interior ) [Minutes]
By adjusting the curing time of each of the top clear coating for the inner plate and the top clear coating for the outer plate so that the following relationship is satisfied:And a method for forming a coating film for an automobile inner plate, characterized by improving a finished appearance at the boundary.
[0009]
The present invention also provides (2)A two-coat, one-bake system automobile in which a top coat base paint is applied, a top coat clear paint for an inner plate is applied on the formed base coat by a wet-on-wet method, and then the entire coat is heated and cured. A method of forming a coating film for an inner plate, wherein at a boundary portion between the inner plate portion and the outer plate portion, the inner plate top coating clear paint and the outer plate top coating clear paint are applied by a wet-on-wet method. The adjustment of the curing time between the top coating clear paint for the inner plate and the top coating clear coating for the outer plate is performed with a curing agent, and the reactivity of the curing agent blended in the top coating clear coating for the inner plate is relatively high. In addition, by making the reactivity higher than the reactivity of the curing agent blended in the top coat clear coating for the outer plate, to improve the finish appearance of the coating at the boundary site Is-car plate for forming a coating film wherein the.
[0010]
The present invention further provides (3)A two-coat, one-bake system automobile in which a top coat base paint is applied, a top coat clear paint for an inner plate is applied on the formed base coat by a wet-on-wet method, and then the entire coat is heated and cured. A method of forming a coating film for an inner plate, wherein at a boundary portion between the inner plate portion and the outer plate portion, the inner plate top coating clear paint and the outer plate top coating clear paint are applied by a wet-on-wet method. Under the temperature conditions for the heat curing, the single curing start time of the top coating clear paint for the inner plate is defined as TI ( interior ), The independent curing start time of the topcoat clear paint for the outer exterior ), And the curing saturation time of the overcoat clear paint for the inner plate alone is TE ( interior ), The sole curing saturation time of the top clear coating for exterior exterior ), The TI ( interior ) For 0.7 to 8 minutes. exterior ) Is between 0.8 and 10 minutes, and
2 ≧ TI ( exterior ) [Min]-TI ( interior ) [Minutes] ≧ 0
TE ( exterior ) [Min] ≧ TE ( interior ) [Minutes]
As the relationship is satisfied, the curing time of each of the top coating clear paint for the inner plate and the top coating clear coating for the outer plate is adjusted with a curing agent, and the curing agent blended in the top coating clear coating for the inner plate. In the automobile, the reactivity is relatively higher than the reactivity of the curing agent blended in the top coat clear coating for the outer panel, thereby improving the finish appearance of the coating at the boundary portion. This is a method for forming a coating film for a plate.
[0011]
The present invention further provides (4)The method for forming a coating film for an automobile inner plate according to the above (1), wherein the adjustment of the curing time between the top coating clear paint for the inner plate and the top coating clear coating for the outer plate is performed with an acid catalyst. is there.
[0012]
The invention further provides:(5) The curing agent is a melamine resin, and the adjustment of the curing time between the top coat clear paint for the inner plate and the top coat clear paint for the outer plate is performed by changing the degree of alkylation of the melamine resin. (1) A method for forming a coating film for an automobile inner plate according to (1)..
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the operation of the present invention will be described in more detail with reference to specific embodiments.
[0014]
The method for forming a coating film for an automobile inner plate according to the present invention comprises applying a thermosetting resin coating compounded with a metallic pigment or a coloring pigment as an overcoat basecoat, and then applying a wet-on-wet method on the upper portion of the basecoat to form a thermosetting resin for the inner plate. A two-coat, one-bake coating film for an automobile inner plate, which comprises applying a hydrophilic resin clear paint as a top coat clear coat (top coat), and then heating and curing the entire coating film. At the boundary portion between the inner plate portion and the outer plate portion, the top coat clear coat for the inner plate and the top coat clear coat for the outer plate are applied by a wet-on-wet method to form a multilayer coating film.
[0015]
FIG. 1 schematically shows an example of a multilayer structure of a coating film formed by the method for forming a coating film for an automobile inner plate according to the present invention.
[0016]
In the embodiment shown in FIG. 1, an
[0017]
When the top coat base coat 4 is formed, first, the inner plate portion 1a side is coated with a thermosetting resin clear paint for the inner plate by a wet-on-wet method to form the top coat
[0018]
In the present invention, the coating composition of the lower layer than the topcoat basecoat 4 is not particularly limited. In addition to the composition in the embodiment shown in FIG. 1, for example, an undercoat and / or an intermediate coat may be used. Various modes can be adopted, such as a configuration that is omitted or a configuration in which the intermediate coat has two layers. Further, the overcoat base coat is not limited to the structure shown in FIG. 1 at all, and may be composed of two or more layers having different functions as seen in, for example, metallic coating and pearl coating. It is possible. Further, the coating order of the top coat
[0019]
In the present invention, the type of the thermosetting resin clear paint used to form the top coat
In general, topcoat clearcoats for outer panels require weatherability, impact resistance, chemical resistance, and heat resistance in addition to the original transparency and glossiness of the clearcoat. Is required to have the same performance as some outer panels such as transparency and gloss, and the clear paint used for each is roughly classified into the same type, for example, thermosetting acrylic resin paint Even in the case of obtaining these required performances, in order to appropriately adjust the molecular weight of the base resin, the mixing ratio of the base resin and the crosslinked resin, the presence and type of the modified resin, the presence and the type of the additive, and the like, The compositions are different from each other, and from such a difference in composition, for example, curing properties such as curing start time, curing speed, viscosity increase rate during baking, solvent evaporation rate, strain state due to curing shrinkage,
Naturally, they differ. In the present invention, under the same heating and curing temperature, that is, at the temperature conditions applied when baking the top coat, the curing properties exhibited by the thermosetting resin clear paint for the inner plate and the thermosetting resin clear paint for the outer plate In order to satisfy the predetermined relationship with the curing properties exhibited by, the composition of the thermosetting resin clear paint for the inner plate and / or the thermosetting resin clear paint for the outer plate is adjusted in advance, or a combination of both is adjusted. Be appropriate. Thereby, the finish of the paint finish at the boundary portion is improved.
[0020]
Although a specific adjusting method is not particularly limited, the temperature at which the thermosetting resin clear coating for the inner plate is independently set at the time of heating under the temperature condition of the heat-curing of the top coat is set to TI (interior). The initial curing time of the thermosetting resin clear coating for the outer panel is TI (exterior), the curing saturation time of the thermosetting resin clear coating for the inner panel is TE (interior), the thermosetting resin for the outer panel. When the curing saturation time of the clear paint alone is TE (exterior),
2 ≧ TI (exterior) −TI (interior) ≧ 0, and
TE (exterior) ≧ TE (interior)
It is desirable to adjust the respective curing times of the thermosetting resin clear paint for the inner plate and the thermosetting resin clear paint for the outer plate so that the following relationship is satisfied, thereby forming a multilayer coating film. When finished, a highly finished appearance with smooth skin is obtained.
[0021]
On the other hand, in the case of TI (exterior) -TI (interior)> 2, the curing reaction of the top coat clear paint for the inner plate is started before the start of curing of the top coat clear paint for the outer plate at the boundary portion with the outer plate portion. Is started extremely quickly, the adhesion reaction on the wet-on-wet surface is less likely to occur, and the interfacial adhesion decreases. When TI (exterior) -TI (interior) <0, the curing reaction of the top coat clear paint for the outer plate starts quickly before the start of curing of the top coat clear paint for the inner plate at the boundary portion with the outer plate portion. And shrinkage strain occurs. At this time, since the top coat clear paint for the inner plate has not yet sufficiently cured, it is dragged with the shrinkage strain of the top plate clear paint for the outer plate, resulting in poor smoothness as a whole of the multilayer coating film. . Further, in the case of TE (exterior) <TE (interior), even though the hardening of the top coat clear paint for the outer plate is almost completed, the clear coat top coat for the inner plate is still not sufficiently hardened, and the transparent coat is clear. This is because the results are inferior in properties and gloss.
[0022]
In addition, the measurement of the curing start time TI and the curing saturation time TE described in this specification is performed by dynamic viscoelasticity measurement by a DSA method (Dynamic Spring Analysis).
[0023]
That is, in these measurements, a spring having an inner diameter of about 3.0 mm and a number of turns of 30 was made of a copper wire having a diameter of 0.40 mm and used as a sample support. 0.01 g of a coating material was uniformly applied to the support, dried under reduced pressure, and then used for measurement. The actual curing process of the coating film includes a solvent, but at that time, it is only necessary to use a paint having the same nonvolatile content as that of the coating film immediately before being put into a baking oven after painting. Here, a sample having a non-volatile content of about 100% was prepared and represented by its curing start time.
[0024]
For the dynamic viscoelasticity measurement, a forced elastic vibration type dynamic viscoelasticity measuring device (Vibron DDV-II type, manufactured by Toyo Baldwin Co., Ltd.) was used under the conditions of a frequency of 11 Hz and a constant temperature (140 ° C. ± 5 ° C.). did. The time when the sample was quickly mounted was T0The relative elastic modulus is measured over time, and the relative elastic modulus is plotted on the vertical axis and the time is plotted on the horizontal axis, as shown in FIG. 2, and the relative elastic modulus rises rapidly and increases linearly. The intersection between the extended line of the portion and the horizontal axis was determined as the curing start time TI. The intersection of the extension of the process of linearly increasing the relative elastic modulus and the saturation value of the relative elastic modulus was determined as the curing saturation time TE.
[0025]
In the present invention, it is preferable that the TI (interior) is between 0.7 minutes and 8 minutes, and the TI (exterior) is between 0.8 minutes and 10 minutes. However, with such a curing start time, the baking treatment can be performed in a relatively short time, and the degree of progress of the heat curing reaction can be easily controlled, which causes a problem such as overbaking or burning. Because it is difficult.
[0026]
Adjustment of the curing time (curing start time and curing saturation time) of each clear paint as described above can be performed by a curing agent or an additive compounded in the paint composition.
[0027]
The curing agent is also referred to as a cross-linking resin or a cross-linking agent, and various types are used depending on the type of the clear paint, and include, for example, polyvalent isocyanate and aminoplast. Examples of the aminoplast include condensates of urea, thiourea, melamine, benzoguanamine and the like with formaldehyde, and lower alkyl (C1~ C4) Etherified compounds. Of these, a melamine / formaldehyde condensate in which part or all of methylol is etherified with butanol is particularly preferable. Adjustment of the curing time, for example, by changing the reactivity of the curing agent blended in both clear paints, for example, by changing the degree of alkylation when the curing agent is a melamine resin, or by changing the amount added It can be carried out.
[0028]
When the adjustment of the curing time is performed with a curing agent blended in the coating composition, the reactivity of the curing agent blended in the thermosetting resin clear paint for the inner plate is relatively higher than the thermosetting resin for the outer plate. If the reactivity is higher than the reactivity of the curing agent blended in the resin clear paint, it is generally possible to satisfy the above-described predetermined relationship.
[0029]
Adjustment of the curing time by an additive is performed by adding a curing acceleration catalyst and / or a curing retarder.
[0030]
For example, when a curing reaction is carried out between a polyol and a lower alkyl etherified melamine / formaldehyde condensate, the curing is promoted by using p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid and a mixture thereof. Sulfonic acids, alkyl phosphates and the like can be used. If these curing accelerators are used in an excessively large amount, the water resistance of the coating film is lowered. Therefore, it is generally desirable to use 5 parts by weight or less per 100 parts by weight of the solid content of the coating. As the curing retarder used in this system, amines that do not volatilize during coating and volatilize during baking and curing are preferable. Examples include diethylamine, triethylamine, n-butylamine, di-n-butylamine, tri-n-butylamine, isobutylamine, diisobutylamine, cyclohexylamine, monoethanolamine, diethylethanolamine and the like. If the addition amount of the curing retardant is too large, there is a high possibility that the required curing may not be obtained. Therefore, it is generally desirable to use 5 parts by weight or less per 100 parts by weight of the solid content of the paint.
[0031]
When a curing reaction is carried out between a polyol and a polyvalent isocyanate, the acid or amine described above can be used as a curing accelerator. Amine salts and ammonium salts are also suitable additives for adjusting the curing time.
[0032]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples.
[0033]
In the following, “parts” means “parts by weight” unless otherwise specified.
[0034]
Synthesis Example 1
A reaction vessel equipped with a stirrer, a temperature controller and a reflux condenser was charged with 80 parts of xylene and 10 parts of methyl isobutyl ketone. Next, 20 parts of the polymerizable composition having the following composition was added to the reaction vessel, and the temperature was increased by heating with stirring. While refluxing, the remaining 81.5 parts of the polymerizable composition was added dropwise over 3 hours, and then a solution composed of 0.3 parts of azobisisobutyronitrile and 10 parts of xylol was added dropwise over 30 minutes. After the reaction solution was further stirred and refluxed for 2 hours to increase the polymerization rate, the reaction was terminated and an acrylic resin varnish (1) having a nonvolatile content of 50% and a number average molecular weight (Mn) of 18,000 was obtained.
[0035]
The same reaction vessel as in Synthesis Example 1 was charged with 57 parts of xylene and 6 parts of n-butanol, and then 20 parts of the polymerizable composition having the following composition was added, and the temperature was increased by heating with stirring. . While refluxing, the remaining 84 parts of the polymerizable composition were added dropwise over 2 hours, and then a solution composed of 0.5 parts of azobisisobutyronitrile, 23 parts of xylene and 14 parts of n-butanol was added dropwise over 20 minutes. did. After the reaction solution was further stirred and refluxed for 2 hours, the reaction was terminated to obtain an acrylic resin varnish (2) having a nonvolatile content of 50% and a number average molecular weight (Mn) of 3,400.
[0036]
Synthesis Example 3
A material having the following composition was weighed and accommodated in a stainless steel container, and stirred with an experimental stirrer to prepare an overcoating clear paint (1) for an inner plate. The curing start time TI (interior) and the curing saturation time of the overcoating clear paint (1) for the inner plate thus prepared were measured for TE (interior) by the method described above. ) Was 0.7 minutes, and TE (interior) was 1.0 minutes.
[0037]
A stainless steel container was weighed and accommodated with a material having the following composition, and stirred with an experimental stirrer to prepare an overcoat clear paint (2) for an inner plate. When the curing start time TI (interior) and the curing saturation time of the overcoating clear paint (2) for the inner plate thus prepared were measured by TE (interior) by the method described above, the TI (interior) was determined. ) Was 0.8 minutes and TE (interior) was 1.4 minutes.
[0038]
A material having the following composition was weighed and accommodated in a stainless steel container, and stirred with an experimental stirrer to prepare an overcoating clear paint (3) for an inner plate. When the curing start time TI (interior) and curing saturation time of the overcoating clear coating material (3) for the inner plate thus prepared were measured by TE (interior) by the method described above, the TI (interior) was determined. ) Was 8.0 minutes and TE (interior) was 13.1 minutes.
[0039]
A material having the following composition was weighed and accommodated in a stainless steel container, and stirred with an experimental stirrer to prepare an overcoating clear paint (4) for the inner plate. When the curing start time TI (interior) and curing saturation time of the overcoating clear paint (4) for the inner plate thus prepared were measured by TE (interior) by the method described above, the TI (interior) was determined. ) Was 10.0 minutes, and TE (interior) was 19.5 minutes.
[0040]
Materials having the following composition were weighed and placed in a stainless steel container, and stirred with an experimental stirrer to prepare a top coat clear coating material (1) for an outer plate. When the curing start time TI (exterior) and the curing saturation time of the top coat clear coating material (1) thus prepared were measured for TE (exterior) by the method described above, TI (exterior) was obtained. ) For 2.7 minutes and TE (exterior) for 6.3 minutes.
[0041]
Materials having the following composition were weighed and placed in a stainless steel container, and stirred with an experimental stirrer to prepare a topcoat clear coating material (2) for an outer plate. When the curing start time TI (exterior) and the curing saturation time of the topcoat clear coating material (2) for outer plate thus prepared were measured by TE (exterior) as described above, the TI (exterior) was determined. ) Was 0.8 minutes, and TE (exterior) was 1.4 minutes.
[0042]
Materials having the following composition were weighed and stored in a stainless steel container, and stirred with an experimental stirrer to prepare a top coating clear paint (3) for an outer plate. The curing start time TI (exterior) and the curing saturation time of the overcoating clear coating material (3) for outer plate thus prepared were measured by TE (exterior) by the method described above. ) For 3.6 minutes and TE (exterior) for 9.4 minutes.
[0043]
Materials having the following composition were weighed and stored in a stainless steel container, and stirred with an experimental stirrer to prepare a top coat clear coating material (4) for an outer plate. When the curing start time TI (exterior) and the curing saturation time of the top coat clear coating material (4) for outer plate thus prepared were measured by TE (exterior) as described above, the TI (exterior) was determined. ) Was 0.8 minutes and TE (exterior) was 1.1 minutes.
[0044]
A stainless steel container was weighed and stored with a material having the following composition, and stirred with an experimental stirrer to prepare a topcoat clear paint (5) for an outer plate. The curing start time TI (exterior) and the curing saturation time of the overcoating clear paint (5) prepared as described above were measured for TE (exterior) by the method described above. ) Was 10.0 minutes, and TE (exterior) was 21.7 minutes.
[0045]
A material having the following composition was weighed and housed in a stainless steel container, and stirred with an experimental stirrer to prepare a top coating clear paint (6) for an outer plate. The curing start time TI (exterior) and the curing saturation time of the top clear coating material (6) thus prepared were measured for TE (exterior) by the method described above. ) For 12.2 minutes and TE (exterior) for 25.2 minutes.
[0046]
Materials having the following composition were weighed and stored in a stainless steel container, and stirred with an experimental stirrer to prepare a top coating clear paint (7) for an outer plate. The curing start time of the top clear coating material (7) prepared as described above was measured by TI (exterior) and the curing saturation time was measured by TE (exterior) according to the method described above. (exterior) was 8.0 minutes, and TE (exterior) was 13.2 minutes.
[0047]
On a steel test piece of 150 × 70 × 0.8 mm, a cationic electrodeposition paint (Powertop PU-50, manufactured by Nippon Paint Co., Ltd.) is applied as a primer to a thickness of 25 μm, and after heat curing, an intermediate coat is applied. Olga S-90 Sealer (manufactured by Nippon Paint Co., Ltd.) was applied as a coating to a film thickness of 40 μm and cured by heating. Subsequently, as a top coating base paint, an acrylic resin base coat (Super Luck M-80 White, manufactured by Nippon Paint Co., Ltd.) was applied to a thickness of 20 μm, and after setting for 180 seconds, the above-mentioned synthesis was performed by wet-on-wet. The top clear coating material (1) for the inner plate obtained in Example 3 was applied in a film thickness of 35 μm in almost half the area of the test piece, and after setting for 180 seconds, the outer plate obtained in Synthesis Example 7 above was further applied. Top coat clear paint (1) was applied wet-on-wet to the other half area of the test piece, but the boundary between the coating area of the top coat clear paint for the inner plate and the coat area of the top coat clear paint for the outer plate In the part, both paints were applied so as to partially overlap each other. Finally, the entire top coat was baked at 140 ° C. for 20 minutes and cured by heating.
[0048]
With respect to the test piece on which the multilayer coating film was formed in this way, the coating film performance (visual gloss, NID value, smoothness, Heat cycle property, thermal shock property) were evaluated. Table 1 shows the obtained results.
[0049]
Example 2
In Example 1, coating was carried out in the same manner as in Example 1 except that the clear coating for outer plate (2) obtained in Synthesis Example 8 was used instead of the clear coating for outer plate (1), The coating performance of the obtained multilayer coating was similarly evaluated. Table 1 shows the obtained results.
[0050]
Example 3
In Example 1, in place of the top coat clear paint for inner plate (1), the top coat clear paint for inner plate (2) obtained in Synthesis Example 4 was replaced with the top coat clear paint for outer plate (1). Coating was carried out in the same manner as in Example 1 except that the overcoating clear coating material (2) for an outer plate obtained in Synthesis Example 8 was used, and the coating performance of the obtained multilayer coating film was similarly evaluated. Table 1 shows the obtained results.
[0051]
Example 4
In Example 1, instead of the clear top paint (1) for the inner plate, the clear clear paint (3) for the inner plate obtained in Synthesis Example 5 was replaced with the clear clear paint (1) for the outer plate. Coating was performed in the same manner as in Example 1 except that the overcoating clear coating material (5) for an outer plate obtained in Synthesis Example 11 was used, and the coating performance of the obtained multilayer coating film was similarly evaluated. Table 1 shows the obtained results.
[0052]
Example 5
In Example 1, instead of the clear top paint (1) for the inner plate, the clear clear paint (3) for the inner plate obtained in Synthesis Example 5 was replaced with the clear clear paint (1) for the outer plate. Coating was carried out in the same manner as in Example 1 except that the overcoating clear coating for outer panel (6) obtained in Synthesis Example 12 was used, and the coating performance of the obtained multilayer coating was similarly evaluated. Table 1 shows the obtained results.
[0053]
Comparative Example 1
In Example 1, the coating was performed in the same manner as in Example 1 except that the clear coating for outer plate (3) obtained in Synthesis Example 9 was used instead of the clear coating for outer plate (1), The coating performance of the obtained multilayer coating was similarly evaluated. Table 1 shows the obtained results.
[0054]
Comparative Example 2
In Example 1, in place of the top coat clear paint for inner plate (1), the top coat clear paint for inner plate (2) obtained in Synthesis Example 4 was replaced with the top coat clear paint for outer plate (1). Coating was carried out in the same manner as in Example 1 except that the overcoating clear coating for outer panel (4) obtained in Synthesis Example 10 was used, and the coating performance of the obtained multilayer coating was similarly evaluated. Table 1 shows the obtained results.
[0055]
Comparative Example 3
In Example 1, instead of the clear top paint (1) for the inner plate, the clear clear paint (3) for the inner plate obtained in Synthesis Example 5 was replaced with the clear clear paint (1) for the outer plate. Coating was carried out in the same manner as in Example 1 except that the overcoating clear coating material (7) for an outer plate obtained in Synthesis Example 13 was used, and the coating performance of the obtained multilayer coating film was similarly evaluated. Table 1 shows the obtained results.
[0056]
Comparative Example 4
In Example 1, in place of the top coat clear paint for inner plate (1), the top coat clear paint for inner plate (2) obtained in Synthesis Example 4 was replaced with the top coat clear paint for outer plate (1). Coating was carried out in the same manner as in Example 1 except that the overcoating clear coating for outer panel (4) obtained in Synthesis Example 10 was used, and the coating performance of the obtained multilayer coating was similarly evaluated. Table 1 shows the obtained results.
[0057]
Comparative Example 5
In Example 1, in place of the top clear coating material (1) for the inner plate, the clear coating material (4) for the inner plate obtained in Synthesis Example 6 was used instead of the clear coating material (1) for the outer plate. Coating was carried out in the same manner as in Example 1 except that the overcoating clear coating for outer panel (6) obtained in Synthesis Example 12 was used, and the coating performance of the obtained multilayer coating was similarly evaluated. Table 1 shows the obtained results.
[0058]
In addition, evaluation of each coating film performance was performed as follows.
[0059]
Visual gloss
The gloss of the outer surface of the coating film was visually observed under natural light, and was evaluated and classified into three grades: ○: extremely good gloss, Δ: good gloss, ×: poor gloss.
[0060]
NID value
In order to examine the smoothness of the coating film, image analysis was performed on the test piece with a sharpness measuring device (NID meter), and the corresponding PGD value was read.
[0061]
Smoothness
The smoothness of the coating film was visually observed, and evaluated according to three grades: ：: extremely good smoothness, Δ: good smoothness, and ×: poor smoothness.
[0062]
Thermal cycling
90 ° C, 4 hours → 20 ° C, 0.5 hours → -40 ° C, 1.5 hours → 20 ° C, 0.5 hours → 75 ° C, 95% RH, 3 hours → 20 ° C, 0.5 hours → 40 A cycle of from 1.5 ° C. for 1.5 hours to 20 ° C. for 0.5 hours was defined as one cycle, and after 10 cycles of loading, the presence or absence of appearance abnormality such as cracks in the coating film was visually observed.
[0063]
Impact resistance
Impact Deformation Tester (DuPont Type) Using a device specified in JIS K5400 8.3.2, the weight height of a spherical collision reaching a coating crack was measured.
[0064]
[Table 1]
【The invention's effect】
As described above, according to the present invention, by preliminarily adjusting the curing time of each of the top coating clear coating for the inner plate and the top coating clear coating for the outer plate to a predetermined value, these clear coatings can be wet-on-wet. Thus, it is possible to greatly improve the finished appearance of the coating at the boundary between the inner plate portion and the outer plate portion which are overcoated.
[Brief description of the drawings]
FIG. 1 schematically shows an example of a multilayer structure of a coating film formed by a method for forming a coating film for an automobile inner plate according to the present invention.
FIG. 2 is a graph illustrating a method for determining a curing start time and a curing saturation time of a paint from a relative elastic modulus and an elapsed time of the paint when the paint is heated and baked.
[Explanation of symbols]
1 ... car body surface,
1a: inner plate portion of an automobile body,
1b: an outer plate portion of an automobile body,
1c: boundary between inner plate and outer plate,
2: Undercoat,
3: Middle coat,
4: Top coat base coat,
5 ... Top coat clear coat for inner plate,
6 ... Top coat clear coat for outer panel.
Claims (5)
前記加熱硬化に際する温度条件下における、内板用上塗りクリア塗料の単独の硬化開始時間をＴＩ（ ｉｎｔｅｒｉｏｒ ）、外板用上塗りクリア塗料の単独の硬化開始時間をＴＩ（ ｅｘｔｅｒｉｏｒ ）、内板用上塗りクリア塗料の単独の硬化飽和時間をＴＥ（ ｉｎｔｅｒｉｏｒ ）、外板用上塗りクリア塗料の単独の硬化飽和時間をＴＥ（ ｅｘｔｅｒｉｏｒ ）とするとき、前記ＴＩ（ ｉｎｔｅｒｉｏｒ ）が０．７分ないし８分の間、前記ＴＩ（ ｅｘｔｅｒｉｏｒ ）が０．８分ないし１０分の間にあり、かつ
２≧ＴＩ（ ｅｘｔｅｒｉｏｒ ）〔分〕−ＴＩ（ ｉｎｔｅｒｉｏｒ ）〔分〕≧０
ＴＥ（ ｅｘｔｅｒｉｏｒ ）〔分〕≧ＴＥ（ ｉｎｔｅｒｉｏｒ ）〔分〕
なる関係が満たされるように、前記内板用上塗りクリア塗料と前記外板用上塗りクリア塗料のそれぞれ有する硬化時間を調整することによって、前記境界部位における塗装仕上がり外観を向上させることを特徴とする自動車内板用塗膜形成方法。A two-coat, one-bake system automobile in which a top coat base paint is applied, a top coat clear paint for an inner plate is applied on the formed base coat by a wet-on-wet method, and then the entire coat is heated and cured. A method of forming a coating film for an inner plate, wherein at a boundary portion between the inner plate portion and the outer plate portion, the inner plate top coating clear paint and the outer plate top coating clear paint are applied by a wet-on-wet method. In
Under the temperature conditions at the time of the heat curing, the single curing start time of the top clear coating material for the inner plate is TI ( interior ), and the single curing start time of the top clear coating material for the outer plate is TI ( exterior ). When the single curing saturation time of the top clear coating material is TE ( interior ) and the single curing saturation time of the top coating clear coating material is TE ( exterior ), the TI ( interior ) is 0.7 to 8 minutes. The TI ( exterior ) is between 0.8 minutes and 10 minutes, and
2 ≧ TI ( exterior ) [min] −TI ( interior ) [min] ≧ 0
TE ( exterior ) [min] ≧ TE ( interior ) [min]
An automobile characterized by improving the paint finish appearance at the boundary portion by adjusting the curing time of each of the top coating clear paint for the inner plate and the top coating clear coating for the outer plate so that the following relationship is satisfied. Method for forming coating film for inner plate.
前記内板用上塗りクリア塗料と前記外板用上塗りクリア塗料との硬化時間の調整を硬化剤で行い、前記内板用上塗りクリア塗料に配合される硬化剤の反応性が、相対的に、前記外板用上塗りクリア塗料に配合される硬化剤の反応性よりも高いものとすることによって、前記境界部位における塗装仕上がり外観を向上させ ることを特徴とする自動車内板用塗膜形成方法。 A two-coat, one-bake system automobile in which a top coat base paint is applied, a top coat clear paint for an inner plate is applied on the formed base coat by a wet-on-wet method, and then the entire coat is heated and cured. A method of forming a coating film for an inner plate, wherein at a boundary portion between the inner plate portion and the outer plate portion, the inner plate top coating clear paint and the outer plate top coating clear paint are applied by a wet-on-wet method. In
Adjustment of the curing time between the top coating clear paint for the inner plate and the top coating clear coating for the outer plate with a curing agent, the reactivity of the curing agent blended in the top coating clear coating for the inner plate is relatively, by a higher than the reactivity of the curing agent to be incorporated in the top coat clear paint skins, automobile in the plate for forming a coating film wherein the Rukoto improve paint finish appearance in the boundary portion.
前記加熱硬化に際する温度条件下における、内板用上塗りクリア塗料の単独の硬化開始時間をＴＩ（Under the temperature conditions at the time of the heat curing, the independent curing start time of the top coating clear paint for the inner plate is defined as TI ( ｉｎｔｅｒｉｏｒinterior ）、外板用上塗りクリア塗料の単独の硬化開始時間をＴＩ（), TI ( ｅｘｔｅｒｉｏｒexterior ）、内板用上塗りクリア塗料の単独の硬化飽和時間をＴＥ（), The curing saturation time of the clear paint for the top coating for the inner plate alone is TE ( ｉｎｔｅｒｉｏｒinterior ）、外板用上塗りクリア塗料の単独の硬化飽和時間をＴＥ（), The sole curing saturation time of the clear coating for the outer panel is TE ( ｅｘｔｅｒｉｏｒexterior ）とするとき、前記ＴＩ（), The TI ( ｉｎｔｅｒｉｏｒinterior ）が０．７分ないし８分の間、前記ＴＩ（) For 0.7 to 8 minutes. ｅｘｔｅｒｉｏｒexterior ）が０．８分ないし１０分の間にあり、かつ) Is between 0.8 and 10 minutes, and
２≧ＴＩ（2 ≧ TI ( ｅｘｔｅｒｉｏｒexterior ）〔分〕−ＴＩ（) [Min]-TI ( ｉｎｔｅｒｉｏｒinterior ）〔分〕≧０) [Minutes] ≧ 0
ＴＥ（TE ( ｅｘｔｅｒｉｏｒexterior ）〔分〕≧ＴＥ（) [Min] ≧ TE ( ｉｎｔｅｒｉｏｒinterior ）〔分〕) [Minutes]
なる関係が満たされるように、前記内板用上塗りクリア塗料と前記外板用上塗りクリア塗料のそれぞれ有する硬化時間の調整を硬化剤で行い、As the relationship is satisfied, the adjustment of the curing time of each of the top clear coating material for the inner plate and the top coating clear coating material for the outer plate is performed with a curing agent,
前記内板用上塗りクリア塗料に配合される硬化剤の反応性が、相対的に、前記外板用上塗りクリア塗料に配合される硬化剤の反応性よりも高いものとすることによって、前記境界部位における塗装仕上がり外観を向上させることを特徴とする自動車内板用塗膜形成方法。The reactivity of the curing agent blended in the top clear coating for the inner panel is relatively higher than the reactivity of the curing agent blended in the top clear coating for the outer panel. A method for forming a coating film for an automobile inner plate, comprising:
前記内板用上塗りクリア塗料と前記外板用上塗りクリア塗料との硬化時間の調整を、前記メラミン樹脂のアルキル化度を変えることで行うことを特徴とする請求項２または３に記載の自動車内板用塗膜形成方法。 The curing agent is a melamine resin,
The vehicle interior according to claim 2 or 3, wherein the adjustment of the curing time between the top coat clear paint for the inner plate and the top coat clear paint for the outer plate is performed by changing the degree of alkylation of the melamine resin. A method for forming a coating film for a board .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15548797A JP3552466B2 (en) | 1997-06-12 | 1997-06-12 | Method for forming coating film for automobile inner plate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15548797A JP3552466B2 (en) | 1997-06-12 | 1997-06-12 | Method for forming coating film for automobile inner plate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH111632A JPH111632A (en) | 1999-01-06 |
| JP3552466B2 true JP3552466B2 (en) | 2004-08-11 |
Family
ID=15607130
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15548797A Expired - Fee Related JP3552466B2 (en) | 1997-06-12 | 1997-06-12 | Method for forming coating film for automobile inner plate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3552466B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU777444B2 (en) | 1999-06-21 | 2004-10-14 | Flexenable Limited | Aligned polymers for an organic TFT |
| WO2001047043A1 (en) * | 1999-12-21 | 2001-06-28 | Plastic Logic Limited | Solution processed devices |
| JP2006182954A (en) * | 2004-12-28 | 2006-07-13 | Nippon Paint Co Ltd | Intermediate coating composition for automotive inner plate portion, method for forming coating film for automotive inner plate portion and coated product |
| DE102013014683A1 (en) | 2013-09-05 | 2015-03-05 | Mankiewicz Gebr. & Co. Gmbh & Co. Kg | Coating materials and their use in coating systems for components in vehicle interiors |
| JP2017218527A (en) * | 2016-06-09 | 2017-12-14 | 株式会社豊田中央研究所 | Isocyanate curable coating composition and coating method using the same |
-
1997
- 1997-06-12 JP JP15548797A patent/JP3552466B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH111632A (en) | 1999-01-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2636245C (en) | Aqueous intermediate coating composition and method for forming multilayer coating film | |
| JP2003211085A (en) | Method for forming coating film | |
| CN102911572A (en) | coating composition and coating film formation method | |
| JPS6121761A (en) | Metallic finishing method | |
| JPH0925458A (en) | Coating composition containing carbamate functional component and acrylamide functional component | |
| JP7473291B2 (en) | Matte paint composition | |
| JP4638575B2 (en) | Clear coating for automobile top coating, method for forming multilayer coating film, and automobile body | |
| JP3552466B2 (en) | Method for forming coating film for automobile inner plate | |
| JPH06102769B2 (en) | Coating composition, process for producing protective and / or decorative multilayer coatings on a support and said coated support | |
| BRPI0617978A2 (en) | multilayer coating method and primer coating composition | |
| JP4580891B2 (en) | Method for predicting and optimizing chip performance in cured thermosetting coatings | |
| JP2006307213A (en) | Coating and coating system having optimized chipping performance and method of obtaining the same | |
| JP2004532316A (en) | Curable paint having improved compatibility, scratch resistance and mar resistance, cured coated support produced using the same, and method for producing the coating | |
| US5534306A (en) | Process for the preparation of a multicoat finish, non-aqueous coatings and autocrosslinkable polyacrylate resins | |
| JP2922915B2 (en) | Thermosetting coating composition | |
| JP4255998B2 (en) | Coating composition and coated metal plate using the same | |
| JPH093399A (en) | Coating composition and its usage | |
| KR20010020716A (en) | Coating method for car body | |
| JP2000136332A (en) | Coating material composition and method for coating same | |
| JPH02228382A (en) | Intercoating composition | |
| JP2004524153A (en) | Curable paint having improved compatibility, scratch resistance and mar resistance, cured coated substrate produced using the same, and method for producing the same | |
| JPH1190317A (en) | Formation of coating film and coated product | |
| JPH0493374A (en) | Aqueous intercoating material | |
| JP2002527216A (en) | Method for improving the appearance in composite color-plus-clear coatings and compositions for use therewith | |
| JP2002179982A (en) | Base coat coating composition, method for forming multilayered coating film and multilayered coating film |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20040113 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20040413 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20040426 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090514 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090514 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100514 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110514 Year of fee payment: 7 |
|
| LAPS | Cancellation because of no payment of annual fees |