JP4111295B2 - How to apply powder paint - Google Patents
How to apply powder paint Download PDFInfo
- Publication number
- JP4111295B2 JP4111295B2 JP02736199A JP2736199A JP4111295B2 JP 4111295 B2 JP4111295 B2 JP 4111295B2 JP 02736199 A JP02736199 A JP 02736199A JP 2736199 A JP2736199 A JP 2736199A JP 4111295 B2 JP4111295 B2 JP 4111295B2
- Authority
- JP
- Japan
- Prior art keywords
- coating
- aqueous dispersion
- powder coating
- paint
- resin
- 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
Landscapes
- Application Of Or Painting With Fluid Materials (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は粉体塗料の塗装方法に関し、より詳しくは、前補正や導電性塗膜の形成等を目的として第１層として特定の分散安定剤を使用して特定の方法で製造した水性分散粉体塗料を塗装し、第２層として粉体塗料又は特定の分散安定剤を使用した水性分散粉体塗料を塗装して均一な組成の塗膜及び／又は異なった組成の２層の塗膜を形成する塗装方法、又は特定の分散安定剤を使用した水性分散粉体塗料（ａ）を前補正として部分的に塗装し、その後、粉体塗料（ｂ）又は特定の分散安定剤を使用した水性分散粉体塗料（ｃ）を塗装する塗装方法に関する。
【０００２】
【従来の技術】
従来、水可溶性塗料や有機溶剤型塗料を下地として塗装し、その上に粉体塗料等を塗装して塗膜を形成する技術は知られている。ところが、近年、環境問題等から有機溶剤の大気中への拡散を防止するために、有機溶剤を使用しない塗装システムが要求されてきている。この要求を満たす塗料としては、粉体塗料、あるいは粉体塗料を水中に分散させた水性分散粉体塗料が最適であることが判明し、開発を重ねてきた。
【０００３】
なお、この粉体塗料を水中に分散させた水性分散粉体塗料に非常に良く似ている塗料として相転換法で作成されるスラリー塗料が知られている。相転換法によるスラリー塗料の調製は、水可溶性有機溶剤を使用して溶剤型塗料を調製し、有機溶剤分を除去するために溶剤型塗料を水中に強制乳化させ、有機溶剤分を除去して固形の塗料樹脂粒子（樹脂成分だけでなく、顔料、添加剤等を含むもの、以下、塗料樹脂粒子という）を作成し、この塗料樹脂粒子を水中に分散させてスラリー塗料化することにより実施される。即ち、相転換法によるスラリー塗料の調製においては、水中から有機溶剤を回収する必要があった。
【０００４】
また、上記の相転換法で作成されるスラリー塗料を下地として塗装し、その上に粉体塗料等を塗装して塗膜を形成するには種々の問題があった。即ち、このスラリー塗料は、塗料樹脂粒子の分散、安定化のために、主としてアニオン系の界面活性剤やポリカルボン酸をアンモニアやアミン類で中和して得られる増粘安定剤を使用しているため、このスラリー塗料を塗装した塗膜中から水分が蒸発する際に塗料中の中和剤も蒸発・飛散し、従って、塗膜中から水分が一旦蒸発すると塗膜中の塗料樹脂粒子は中和剤を失ったアニオン樹脂となり、その周りにポリカルボン酸のカルボキシル基による水素結合によって形成される強固な被膜を持つこととなる。この被膜は熱による溶融軟化性が乏しく、また粘着性も無いため、塗料樹脂粒子を溶融、融着させることにより塗膜を形成する際に塗膜形成を阻害することになる。このため、成膜時に塗膜に割れが生じたり、平滑性が不足したりした。従って、スラリー塗料は塗装後に一気に昇温させて成膜させることが必要があり、スラリー塗料の上に粉体塗料を塗装して同時に成膜させたり、スラリー塗料の上に時間間隔を置いてスラリー塗料を塗装し、成膜させたりすることはできなかった。
【０００５】
【発明が解決しようとする課題】
本発明は、上記のような諸問題の生じることのない塗装方法を提供すること、即ち、有機溶剤を使用する必要がなく、低コストで製造される安定な水性分散塗料を塗装を必要とする全部分又は一部分に前補正として又は導電性塗膜の形成を目的として塗装し、次いで粉体塗料又は水性分散粉体塗料を塗装しても、成膜時に塗膜に割れが生じたり、平滑性が不足したりすることなしに塗膜性能に優れた均一な組成の塗膜及び／又は異なった組成の２層の塗膜を形成する塗装方法を提供することを課題としている。
【０００６】
【課題を解決するための手段】
本発明者等は、上記の課題を解決するために鋭意検討した結果、水性分散粉体塗料中の塗料樹脂粒子の分散、安定化のために、非揮発性で、塗膜用樹脂と相溶し易いノニオン系の界面活性剤及び／又はノニオン系の増粘安定剤を分散安定剤として使用し、好ましくはその分散安定剤の一部又は全量を塗料樹脂粒子の作成時に塗料樹脂粒子中に均一に配合分散させて使用することにより上記の課題が解決されることを見いだし、本発明を完成した。
【０００７】
即ち、本発明の粉体塗料の塗装方法は、下層となる第１層として、
（１）塗膜構成成分となる諸原料並びにノニオン系界面活性剤及び／又はノニオン系増粘安定剤からなる分散安定剤を混合して配合物を得る工程、
（２）該配合物を樹脂成分の軟化温度以上の温度で溶融練合して均質化物を得る工程、 （３）該均質化物を冷却固化後に粗砕して粗粒子を得る工程、及び
（４）該粗粒子を水性分散媒中で湿式粉砕して平均粒子径が１０μｍ以下の微粒子を含む水性分散粉体塗料を得る工程
を順次実施することにより製造された水性分散粉体塗料（ａ）を塗装し、上層となる第２層として、粉体塗料（ｂ）又は、ノニオン系界面活性剤及び／又はノニオン系増粘安定剤を分散安定剤として使用した水性分散粉体塗料（ｃ）を全面に又は必要とする部分に塗装することを特徴とする。
【０００８】
また、本発明の粉体塗料の塗装方法は、下層となる第１層として、上記の水性分散粉体塗料（ａ）を塗装し、塗装後塗膜中の水分による導電性が消失する前に、上層となる第２層として、粉体塗料（ｂ）又は、ノニオン系界面活性剤及び／又はノニオン系増粘安定剤を分散安定剤として使用した水性分散粉体塗料（ｃ）を全面に又は必要とする部分に静電塗装することを特徴とする。
【０００９】
更に、本発明の粉体塗料の塗装方法は、上記の水性分散粉体塗料（ａ）を前補正として部分的に、即ち前補正を必要とする所定の部分に塗装し、その後、粉体塗料（ｂ）又は、ノニオン系界面活性剤及び／又はノニオン系増粘安定剤を分散安定剤として使用した水性分散粉体塗料（ｃ）を塗装することを特徴とする。
【００１０】
【発明の実施の形態】
本発明の塗装方法においては、塗布された水性分散粉体塗料（ａ）、及び粉体塗料（ｂ）又は水性分散粉体塗料（ｃ）のそれぞれの塗料樹脂粒子が加熱によって熱軟化又は溶融し、均質な塗膜となることが必要である。従って、本発明の塗装方法で用いる水性分散粉体塗料又は粉体塗料を構成する塗料樹脂粒子の軟化温度は好ましくは１０〜２５０℃、更に好ましくは３０〜２００℃である。
【００１１】
塗料樹脂粒子の軟化温度が１０℃よりも低い場合には、塗料の通常の保管温度においても、水性分散粉体塗料中の塗料樹脂粒子が水性媒体中にあるにも拘わらず凝集し易くなる傾向がある。その理由は、エマルション塗料等中の塗料樹脂粒子の大きさと比較して、粉体塗料樹脂粒子の粒子径が１００倍から１０００倍大きいためである。水性分散粉体塗料中の塗料樹脂粒子の平均粒子径を小さくすればする程、軟化温度が低い塗料樹脂粒子であっても、水性分散粉体塗料を安定に保つことができる。しかし、この場合には水性分散粉体塗料中の塗料樹脂粒子の合計表面積が大きくなるので、塗料樹脂粒子を水媒体中に安定に分散させるために界面活性剤等の湿潤剤を多く存在させることが必要となる。従って、このような場合には、得られる塗膜の耐水性、光沢等の性能が低下することになる。
【００１２】
また、塗料樹脂粒子の軟化温度が２５０℃を超える場合には、塗膜を形成させるための加熱硬化に２５０℃を超える温度が必要であり、そのような高温では塗膜が黄色に変色したり、塗膜が空気で酸化されて可撓性を失ったりする傾向があるので好ましくない。そのような現象の防止方法として、特殊な例としては、炭酸ガス等の不活性ガス雰囲気中で成膜させる方法があるが、この場合にはそのような不活性ガス雰囲気を形成するための装置が余分に必要になる。また、樹脂成分としてオレフィン樹脂や、高分子のフッ素樹脂を使用した塗料を成膜させる場合にはそのような現象は生じにくい傾向がある。
【００１３】
上記のような塗料樹脂粒子の樹脂成分として、アルキド樹脂、アクリル樹脂、ポリエステル樹脂、エポキシ樹脂、メラミン樹脂、ブロックイソシアネート樹脂、フッ素樹脂、シリコン樹脂、アミド樹脂、ＡＢＳ樹脂等を挙げることができ、それらの樹脂成分は単独で、又は、必要によって、任意の配合比率で組み合わせで使用することができる。更に必要に応じて、通常の塗料に使用されている二塩基酸や多塩基酸、ポリアミド樹脂等の硬化剤や、表面調整剤、硬化促進剤等の添加剤を添加することもできる。
【００１４】
これらの樹脂、硬化剤等の外に、塗膜構成成分として、着色顔料や防錆顔料、その他の機能を与えるための添加剤等を加えることが有効である。これらの着色顔料としては、黄色酸化鉄、チタン黄、ベンガラ、酸化チタン、亜鉛華、リトポン、鉛白、硫化亜鉛、酸化アンチモン等の無機系顔料や、ハンザイエロー５Ｇ、パーマネントエローＦＧＬ、フタロシアニンブルー、インダンスレンブルーＲＳ、パーマネントレッドＦ５ＲＫ、ブリリアントファーストスカーレットＧ、パリオゲンレッド３９１０等の有機顔料がある。
【００１５】
塗料樹脂粒子中へのこれら顔料の添加量は、通常ＰＷＣで０．５〜６０％程度であるが、クリヤー塗料の様に全く添加しない場合もある。
ここで、ＰＷＣとは Pigment Weight Concentration （顔料重量濃度）のことであり、下記の式により算出される。
ＰＷＣ＝［（含有顔料重量％）／（全塗料固形分重量％）］×１００
【００１６】
これらの顔料の添加量が多い場合には、特に吸油量の高い顔料を用いる場合には、そのような塗料を用いて塗膜を形成すると、塗膜の平滑性が損なわれる傾向がある。
その他に、塗膜の光沢値を調節したり、塗膜の堅さを調節したりする目的で、体質顔料として、硫酸バリウム、炭酸バリウム、炭酸カルシウム、クレー、シリカ粉、微粉珪酸、珪藻土、タルク、塩基性炭酸マグネシウム、アルミナホワイト等を添加することもできる。
【００１７】
本発明の塗装方法においては、塗料中に光輝性薄片状顔料を含有させてメタリック塗料とし、この塗料を用いてデザイン的に有効な塗膜を形成させることからなるメタリック塗装を実施することができる。このような光輝性薄片状顔料として、通常のアルミニウム顔料、マイカ顔料、ブロンズ粉、銅粉、ステンレス粉や、金属コーティングした硝子粉、金属コーティングしたマイカ粉、金属コーティングしたプラスチック粉等が使用できる。
【００１８】
水性分散粉体塗料の場合には、光輝性薄片状顔料を塗料樹脂粒子中に含有させることもできるが、好ましくは、水性分散粉体塗料の水媒体中に塗料樹脂粒子とは別個に含有させることが好ましい。この添加方法については特に制約されるものでは無いが、予め水可溶性溶媒や界面活性剤で光輝性薄片状顔料表面を親水性にし、更に必要なら水溶性樹脂や添加剤等を併用して加えることもできる。
これらの光輝性薄片状顔料は、各々単独で含有させることも、２種以上を同時に使用することも可能である。光輝性薄片状顔料の塗料中への添加量は、全固形分の０．０５〜３０重量％程度であることが好ましい。
【００１９】
本発明の塗装方法により形成される塗膜のツヤを調製するために、塗料中にツヤ消し用顔料を加えることが可能である。また、塗料中の塗料樹脂粒子を２種類以上の混合物とし、それらの塗料樹脂粒子間の相溶性や反応速度の差でツヤを調整することもできる。これらのツヤ調整剤としては、塗料に通常使用されているコロイダルシリカ、アルミナ、タルク等を使用することができる。
【００２０】
本発明の塗装方法で用いる水性分散粉体塗料（ａ）及び（ｃ）においては、塗料樹脂粒子を水媒体中に安定に分散させるために分散安定剤を使用する必要があり、本発明においては分散安定剤としてノニオン系界面活性剤及び／又はノニオン系増粘安定剤を用いる。
【００２１】
本発明で使用するノニオン系界面活性剤としては、ポリエチレングリコール型ノニオン界面活性剤、多価アルコール型ノニオン界面活性剤等があり、ポリエチレングリコール型ノニオン界面活性剤としては、ポリエチレングリコール型ノニオン界面活性剤、高級アルコールエチレンオキサイド付加物、アルキルフェノールエチレンオキサイド付加物、脂肪酸エチレンオキサイド付加物、高級脂肪族アミンエチレンオキサイド付加物、脂肪族アミドエチレンオキサイド付加物、ポリプロピレングリコールエチレンオキサイド付加物等がある。また、多価アルコール型ノニオン界面活性剤としては、グリセリンの脂肪酸エステル、ペンタエリスリットの脂肪酸エステル、ソルビットの脂肪酸エステル、ソルビタンの脂肪酸エステル、脂肪酸アルカノールアミド等がある。
【００２２】
これらノニオン系界面活性剤の中でも、水性分散粉体塗料として塗料樹脂粒子を均一に湿潤、分散させるためには、ＨＬＢが７以上の界面活性剤が好ましい。しかし、ＨＬＢが２２を超える界面活性剤を用いると、勿論添加量にもよるが、塗膜の耐水性等の性能が低下する傾向があるので好ましくない。更に好ましくはＨＬＢが８〜１８程度の界面活性剤を用いる。
【００２３】
塗料樹脂粒子中に、又は塗料樹脂粒子中及び水媒体中に加える界面活性剤の総量は、塗料樹脂粒子の重量の０．１〜５重量％程度となる量にすることが好ましい。この場合、塗料樹脂粒子内に加える添加量の割合を多くすると、水媒体中にだけ加える場合に比べ、水性分散粉体塗料の全体に必要な界面活性剤の総量を約２分の１とすることができ、この約２分の１の添加量で、水媒体中にだけ加える場合と同等以上の湿潤、分散性を得ることができる。このため、塗膜性能、特に耐水性、光沢等の良好な塗膜を形成することができる。
【００２４】
また、ノニオン系増粘安定剤としては、特に、ポリエチレングリコール型増粘安定剤を挙げることができ、増粘安定効果の点では分子量の大きい増粘安定剤が好ましい。しかし、分子量が１００万以上になると、水性分散粉体塗料の貯蔵安定性は良好であるが、エアースプレー塗装等におけるように微粒化して塗装する方法では、塗装時、糸引き現象を発生する傾向があるので好ましくないが、プレコートメタルでの塗装の様に、ロール塗装やフローコート塗装では、塗料の追随性や膜形成性が良いので好ましい。
【００２５】
塗料樹脂粒子中に、又は塗料樹脂粒子中及び水媒体中に加えるノニオン系増粘安定剤の総量は、通常、エアースプレー塗装、静電塗装、エアレス塗装、回転霧化型静電塗装に使用する水性分散粉体塗料の場合で、分子量が数十万程度のノニオン系増粘安定剤を用いる場合には、塗料樹脂粒子の重量の０．３〜５重量％程度となる量にすることが好ましい。また、ロール塗装やフローコート塗装に使用する水性分散粉体塗料の場合で、分子量が数十万〜２百万程度のノニオン系増粘安定剤を用いる場合には、塗料樹脂粒子の重量の０．１〜５重量％程度となる量にすることが好ましい。
【００２６】
本発明で用いる水性分散粉体塗料は、水媒体中に上記の分散安定剤を溶解しておいてその中で塗料樹脂粒子の原料を湿式粉砕する方法によっても製造することができる。しかしながら、この方法では、湿式粉砕の初期と終わりで、塗料樹脂粒子表面に吸着する分散安定剤の濃度が異なり、特に塗料樹脂粒子の合計表面積が多くなる湿式粉砕の終点においては、塗料樹脂粒子表面に吸着された分散安定剤の希薄な塗料樹脂粒子が出来るためか、凝集し易くなる傾向があるので好ましくない。
【００２７】
本発明で用いる水性分散塗料を製造する際に、好ましくは、これらの分散安定剤の一部または全量を塗膜構成成分と一緒に混合し、溶融練合することによって塗料樹脂中に均一に分散させる。この塗料樹脂を冷却固化後に粗砕し、その粗粒子を水性分散媒体中で湿式粉砕すると、この粉砕によって新しく生成する塗料樹脂粒子の表面には常に均一に分散安定剤が現れるのでその塗料樹脂粒子は親水性になる。その結果、塗料塗料樹脂粒子が微細に湿式粉砕されて表面積が増加しても、塗料樹脂粒子の湿潤性や増粘安定性は一定に保たれる。更に、塗料樹脂粒子が微細になるほど、通常は凝集し易くなるが、分散安定剤を含有する塗料樹脂粒子の場合には、塗料樹脂粒子の表面特性が上記のように常に一定で均一なため、塗料樹脂粒子は水性分散塗料中において安定に分散する。従って、この場合には、前記したように、分散安定剤を水媒体中にだけ加える場合に比べ、水性分散粉体塗料の全体に必要な界面活性剤の総量を約２分の１として、水媒体中にだけ加える場合と同等以上の湿潤、分散性を得ることができるので、分散安定剤の配合量が少なくなったことと、均一に分散していることのため、偏在が無く、塗膜性能も良好になる。しかし、一番の相違点は、塗料のｐＨ依存性が無く、ｐＨが中和点より低い３程度でも何ら支障無く塗布、成膜できる。
【００２８】
本発明の塗装方法においては、分散安定剤としてノニオン系界面活性剤及び／又はノニオン系増粘安定剤を使用するのであり、これらの分散安定剤は中和剤を使用しないため、塗装後の水分の蒸発によっても塗料樹脂粒子の熱軟化性や流動性があまり変化しない。従って、水性分散粉体塗料の塗装後、その塗膜が湿潤状態であっても、完全に乾燥した状態であっても、その上に粉体塗料や水性分散粉体塗料を塗装して加熱成膜させることができる。
【００２９】
本発明の塗装方法で用いる水性分散粉体塗料は上記の特性を有しているので、前補正を目的として第１層として上記の水性分散粉体塗料を塗装し、第２層として粉体塗料又は水性分散粉体塗料を塗装するか、又は非導電性素材に導電性塗膜を形成することを目的として第１層として上記の水性分散粉体塗料を塗装し、第２層として粉体塗料又は水性分散粉体塗料を静電塗装して均一な組成の塗膜及び／又は異なった組成の２層の塗膜を形成することができる。
【００３０】
例えば、箱物の内部を粉体塗料で塗装する場合に、気流や電位の関係でコーナー部分の膜厚が薄くなる傾向にある。この様なコーナー部分を予め水性分散粉体塗料で前補正し、その後粉体塗料を塗装することで、コーナー部分まで確実に塗装することができる。即ち、水性分散粉体塗料を前補正として部分的に、即ち前補正を必要とする所定の部分に塗装し、その後、粉体塗料又は水性分散粉体塗料を塗装することができる。
【００３１】
本発明の塗装方法においては、当然のことではあるが、水性分散粉体塗料のみで全てを塗装して仕上げる事も可能である。他方、第１層として塗装される水性分散粉体塗料（ａ）に使用される塗料樹脂粒子の組成と、第２層として塗装される粉体塗料（ｂ）又は水性分散粉体塗料（ｃ）に使用される塗料樹脂粒子の組成とは、同一の組成であっても、類似の組成であっても、または、全く異なる組成であってもよい。第１層に塗装する水性分散粉体塗料の塗料樹脂粒子の組成と第２層に塗装する粉体塗料または水性分散粉体塗料の塗料樹脂粒子の組成とが異なる場合には、連続的に、又は層状に異なる樹脂組成の塗膜を容易に形成する事が出来る。
【００３２】
＜水性分散粉体塗料（ａ）及び（ｃ）の製造方法＞
本発明で使用する水性分散粉体塗料（ａ）は、
（１）塗膜構成成分となる諸原料並びにノニオン系界面活性剤及び／又はノニオン系増粘安定剤からなる分散安定剤を混合して配合物を得る工程、
（２）該配合物を樹脂成分の軟化温度以上の温度で溶融練合して均質化物を得る工程、 （３）該均質化物を冷却固化後に粗砕して粗粒子を得る工程、及び
（４）該粗粒子を水性分散媒中で湿式粉砕して平均粒子径が１０μｍ以下の微粒子を含む水性分散粉体塗料を得る工程
を順次実施することにより製造することができ、水性分散粉体塗料（ｃ）はノニオン系界面活性剤及び／又はノニオン系増粘安定剤からなる分散安定剤を（１）工程又は（４）工程で混合することにより製造することができる。
【００３３】
上記（１）の工程、即ち、塗膜構成成分となる諸原料を混合して配合物を得る工程、又は塗膜構成成分となる諸原料並びにノニオン系界面活性剤及び／又はノニオン系増粘安定剤からなる分散安定剤を混合して配合物を得る工程においては、固形の樹脂原料を中心に着色顔料、硬化剤、添加剤、分散安定剤、更に必要によっては少量の液状原料をできるだけ均質に混合する。
このための装置としては、粉体原料を混合する通常の装置であるフラッシュミキサー、スクリューミキサー、コニカルブレンダ、Ｖミキサー、タンブリングミキサー、ジェットミキサー、ニーダー、リボンミキサー等が使用できる。
これらの装置を用いて諸原料を混合配合し、できるだけ均質にすることが好ましいが、諸原料の合計量が少量である場合には、諸原料を袋の中で簡単に混合し次の溶融練合工程で均質にすることもできる。特に、塗料樹脂粒子を水媒体中に容易に分散させる働きをする前記の分散安定剤の一部または全部をこの混合配合工程において添加しておくと、後の湿式粉砕工程において塗料樹脂粒子の新しく生成する粉砕表面も均しく親水性であるので水性分散粉体塗料の生成が容易になる。
【００３４】
次に、上記（２）の工程、即ち、上記配合物を上記樹脂成分の軟化温度以上の温度で溶融練合して均質化物を得る工程を実施する。この工程は、塗料樹脂粒子の原料である固形の樹脂原料、着色顔料、硬化剤、添加剤などを数μｍ以下の程度まで均質に混合することを目的としている。本発明で使用する水性分散粉体塗料の樹脂原料や硬化剤は、輸送や配合時の取り扱いを容易にし且つ粉塵の舞い上がりが生じることのないようにする目的で、数ｍｍ程度のペレットに加工されている。このペレットを破砕して数百μｍ程度の粒子からなる混合物にし、これを樹脂成分の軟化温度以上に加温して機械的に練合する。
【００３５】
この練合に用いる装置として、ロールミル、スクリューニーダー、マーラー、ニーダー等がある。特に好ましい装置は、作業性、取り扱い易さの点でロールミル、スクリューニーダーである。これらの装置は、溶融練合後、練合物を速やかに装置より排出して冷却することができる点で好ましい。特に、架橋型水性分散粉体塗料の場合には塗料樹脂粒子中に硬化剤が含まれるものであり、それでこの溶融練合工程で樹脂成分、硬化剤等が均質に混合され、この時、樹脂成分の軟化温度以上に加熱されるので、練合する時の滞留時間が長くなると樹脂成分の一部が硬化剤と反応してしまい、その結果として塗膜を形成する時に平滑にならなかったり、光沢不足の欠陥を生じたりする傾向がある。従って、一方向から供給し他方から連続的に排出する形式の装置を用いることが好適である。
【００３６】
次に、上記（３）の工程、即ち、上記均質化物を冷却固化後に粗砕して粗粒子を得る工程に入る。この工程での処理は、前段の溶融練合工程でできる塗料樹脂均質化物はそのままで冷却固化させると塊状になるので、これを次の湿式粉砕工程で処理し易い粗粒子にするための前処理である。粗砕するための装置の例としてはリングロールミル、エッジランナー、ロールクラッシャー、ディスインテグレータ、ハンマクラッシャ、インペラブレーカ、ジャイレトリークラッシャ、ジョウクラッシャ等がある。
【００３７】
次に、上記（４）の工程、即ち、上記粗粒子を水性分散媒中で湿式粉砕して平均粒子径が１０μｍ以下の微粒子を含む水性分散粉体塗料を得る工程について説明する。
まず第一に、水性分散粉体塗料を受容するタンクに必要量の水を準備する。必要に応じて、この水に塗料樹脂粒子の湿潤のための界面活性剤や、沈殿防止剤等を加え、混合して均質にする。この水媒体を循環ポンプにより湿式粉砕機に循環させておく。この循環経路の湿式粉砕機の入り口側に上記粗粒子の取り込み口を設ける。ここに取り込まれた粗粒子は自重で水媒体中に混合された後に湿式粉砕機の中へ入ってもよく、また、何らかの攪拌混合機で湿潤された後に湿式粉砕機の中へ取り込まれてもよい。
【００３８】
この場合に重要なことは、十分な量の水媒体が湿式粉砕機中を循環して装置内の冷却と粉砕微粒子の搬送とを十分に実行できることである。粉砕開始後の初期段階においては循環水媒体中の塗料樹脂粒子の濃度が低く、従ってその塗料樹脂粒子含有水媒体の粘度も低いので、塗料樹脂粒子含有水媒体は循環しやすいが、順次添加される粗粒子の湿式粉砕が進み、水媒体の循環が繰り返されると循環水媒体中の塗料樹脂粒子の濃度が高くなるので、循環と冷却とが次第に困難になってくる。万が一水媒体の循環が停止すると、循環水媒体中に供給された粗粒子及び循環していた塗料樹脂粒子が湿式粉砕機中で粉砕エネルギーによって溶融し、装置の内面に固着したりする危険がある。このため、目的とする水性分散粉体塗料中の塗料樹脂粒子濃度、流動性の設定、水性分散粉体塗料の循環量、温度の管理は重要である。通常、循環量は容易に管理できるが、温度は、循環量が低下すると急激に上昇するため、粗粒子の供給量と水媒体の循環量、最終水性分散粉体塗料中の塗料樹脂粒子濃度等は十分に管理する必要がある。
【００３９】
次に、この湿式粉砕工程で使用しうる湿式粉砕機の例について述べる。使用可能な湿式粉砕機としては、ディスクグラインダ、タワーミル、ボールミル、振動ミル、エッジランナ、ロールミルなどがある。タワーミル、ボールミル、振動ミルのように分散メジアを使用する湿式粉砕機では、供給する粗粒子の大きさがメジアの粒子径より大きいと湿式粉砕の効率が著しく低下する。従って、分散メジアを使用する湿式粉砕機の場合には、粗粒子をメジアの粒子径に比べて十分に小さくして供給する必要がある。ディスクグラインダ、ロールミルのように粗粒子を回転体に鋏んで粉砕するタイプの湿式粉砕機では、かなり大きい粗粒子でも粉砕することは容易であるが、湿潤させる水媒体の循環量が不足したり、部分的に偏ったりすると、発熱により塗料樹脂粒子が融着し易い傾向がある。
【００４０】
湿式粉砕機の運転態様としては、塗料樹脂粒子濃度を低濃度に維持して運転すると管理が容易であるので、必要に応じて、遠心濾過機、遠心分離機、デカンタ等を用いて塗料樹脂粒子濃度を調整することが好ましい。湿式粉砕処理については、塗料樹脂粒子が一定の大きさの粒子径になるまで数回湿式粉砕機を通過させることも、また一定の大きさ以上の塗料樹脂粒子をフィルターや遠心分級機などで分離、除去することもできる。塗料樹脂粒子濃度を所定の濃度に調整した後、後調整として防黴剤や消泡剤、粘性付与剤等の添加剤等を加えて水性分散粉体塗料とする。
【００４１】
でき上がった水性分散粉体塗料は、その中に分散している塗料樹脂粒子の平均粒径が１０μｍ以下で、含有濃度が２０〜６０重量％程度のものである。
ここで重要な特徴は、水媒体中で直接湿式粉砕して塗料化するので、また、必要によっては、塗膜構成成分となる諸原料中に予め水中分散用の水系界面活性剤や水系増粘安定剤の一部または全部が添加されているので、塗料樹脂粒子が容易に水媒体中に湿潤し、分散、安定化されることにある。この結果、従来の相転換法で作成されるスラリー塗料や、粉体塗料を更に微粉砕して得られる微粒子を水性媒体中に湿潤させて得られる水性分散粉体塗料に比べ、分散安定剤の必要量が少なく、かつ粒子径の小さい塗料樹脂粒子の水性分散粉体塗料が容易に調製できる。
【００４２】
＜粉体塗料の製造方法＞
本発明で使用する粉体塗料（ｂ）は、
（１）塗膜構成成分となる諸原料を混合して配合物を得る工程、
（２）該配合物を樹脂成分の軟化温度以上の温度で溶融練合して均質化物を得る工程、
（３）該均質化物を冷却固化後に粗砕して粗粒子を得る工程、
（４）該粗粒子を水性分散媒中で湿式粉砕して平均粒子径が１０μｍ以下の微粒子を含む水性分散液を得る工程、及び
（５）該水性分散液を脱水処理して粉体塗料を得る工程
を順次実施することにより製造することができる。
【００４３】
上記（１）〜（４）の工程は、前記した水性分散粉体塗料の製造方法の（１）〜（４）の工程と同じであるので説明は省略する。
上記の（５）の工程、即ち、上記の水性分散液を脱水処理して粉体塗料を得る工程は、フィルタープレス、葉状濾過機、回転濾過機等のケーキ濾過機、遠心濾過機、遠心分離機等を用いて脱水し、乾燥することによって実施される。このような脱水、乾燥によって塗料樹脂微粒子は凝集するので乾燥後に破砕処理して粉体塗料とする。
【００４４】
本発明の粉体塗料の塗装方法においては、第１層として、又は前補正として部分的に水性分散粉体塗料（ａ）を塗装する。この塗装方法としては、水系塗料で採用される通常の塗装方法を採用することができ、例えばエアースプレー塗装、静電塗装、ディップ塗装、刷毛塗り塗装、ロール塗装やフローコート塗装を挙げることができる。
【００４５】
該水性分散粉体塗料（ａ）においては、塗布して未乾燥の状態では、塗膜内部にある水分は塗料樹脂粒子の間を毛細管現象によって自由に移動できるので、乾燥過程において、塗膜内部に水分がある間、塗膜表面で水が蒸発するにつれて、塗膜内部の水が塗料樹脂粒子の間を毛細管現象によって自由に塗膜表面まで移動する。この移動速度は乾燥過程の終わりにおいても十分に速く、水溶性樹脂塗料やエマルション塗料の場合の塗膜内部を水が拡散によって表面に供給される速度に比べてかなり大きく、従って、水は塗膜表面より一定の早い速度で蒸発する。このため、加熱によって内部の水が沸騰し、ピンホールを形成するようなことも少ない。このため、沸点調整用の高沸点溶剤を併用する必要も無く、塗料のＶＯＣも極めて少なく、通常１％以下である水性分散粉体塗料となる。
【００４６】
該水性分散粉体塗料（ａ）を用いることによる塗膜形成は、
（Ａ）水分の蒸発工程、塗料樹脂粒子層の形成工程、
（Ｂ）塗料樹脂粒子の溶融、融着工程
を経て、連続塗膜を形成する。
【００４７】
上記の諸工程は、エマルション塗料や水溶性塗料で加熱、成膜工程で必要な程度には、厳格に工程を管理する必要はないが、膜厚が厚い場合には、水の沸騰によるピンホールの発生を防止するため昇温速度の管理に注意をすることが好ましい。上記の（Ａ）工程及び（Ｂ）工程はそれらの工程の間に時間を置かないで連続的に実施しても、あるいは時間を置いて段階的に実施しても良い。上記の（Ａ）工程及び（Ｂ）工程間に時間を置いて段階的に実施しても、即ち、塗装後、室温にて放置し、任意の時間経過後、加温して成膜させても、従来のアニオン系添加剤を使用した塗料の場合に発生した様な割れが塗膜に発生することはない。室温で長期間放置した塗膜は、水が蒸発し、塗料樹脂粒子が析出して粉体塗料を塗装した場合とほとんど同じ状態の成膜過程を経て成膜する。
【００４８】
第１層の塗装後又は前補正としての部分的な塗装後に、第２層として又は前補正のない部分については仕上層として（以下、これらを総称して第２層と記載する）粉体塗料（ｂ）又は水性分散粉体塗料（ｃ）を塗装する。
第２層の塗装方法としては、通常の塗装方法を採用することができ、粉体塗料（ｂ）においては、例えば静電塗装等を挙げることができる。また、水性分散粉体塗料（ｃ）においては、例えば、エアースプレー塗装、静電塗装、ディップ塗装、刷毛塗り塗装、ロール塗装やフローコート塗装を挙げることができる。
【００４９】
本発明の粉体塗料の塗装方法においては、第１層の塗膜の乾燥状態によらずに第２層を塗装することができる。即ち、第１層を塗装した後、直ちに、又はしばらく放置した後に第２層を塗装し、第１層と第２層とを同時に硬化、成膜させることが可能であり、あるいは第１層を塗装し、硬化、成膜させた後に、第２層を塗装し、硬化、成膜させることも可能である。このため、第１層として、水性分散粉体塗料（ａ）を塗装し、塗装後水分による導電性が消失する前に、第２層として、粉体塗料（ｂ）又は、水性分散粉体塗料（ｃ）を静電塗装することも可能である。
【００５０】
本発明の粉体塗料の塗装方法においては、水により吸着力等の強い力で塗料樹脂粒子が被塗装物に付着しているため、プラスチック等の付着力の弱い被塗装物の場合でも落下することはない。従って、塗装後の放置時間は任意であるが、埃等の付着や、塗装ラインの長さ、保管場所等の有効利用を考慮すると、塗装後できるだけ短時間に乾燥、加熱し成膜させることが好ましい。
【００５１】
短時間に成膜させる場合には、塗膜形成工程（Ｂ）の塗料樹脂粒子の溶融、融着工程に入る際に、水の沸騰温度である１００℃まで被塗装物を加熱し、昇温させるのに２０秒以上の時間をかけることが好ましい。通常、１００℃に達する時間が１分〜３分程度となるような加温速度で昇温させ、１００℃を越した時点においては所定の反応温度まで任意に昇温させ、その温度に保持して塗膜を架橋成膜させる。従って、エマルション塗料や水溶性塗料を加熱、成膜させる時に要求される、８０〜１００℃で５分〜１０分加熱し、その後所定の温度に昇温して硬化させるという工程は不要である。
【００５２】
【実施例】
次に、本発明を実施例及び比較例によって更に詳細に説明する。尚、以下の記載において「部」は重量部を示す。
＜エポキシ／ポリエステル樹脂水性分散粉体塗料＞の調製
軟化温度１２０℃、酸価４５のポリエステル樹脂３２部、エポキシ当量９１０のビスフェノールＡタイプのエポキシ樹脂３２部、チタン顔料２５部、カーボンブラック０．１部、その他酸化鉄系顔料０．１部、表面調整剤６部、紫外線吸収剤２部、酸化防止剤１部、硬化促進剤１部、ＨＬＢ１２のノニオン系界面活性剤０．８部、及び分子量３０万のノニオン系増粘安定剤０．８部をスクリューミキサー中で配合し、さらにフラッシュミキサーで均一に混合した。
【００５３】
一方、溶融練合機として２軸スクリューニーダーを用い、それを１１５℃に加温し、溶融練合機の先端に、圧延冷却用の２本ロール冷却機を設け、その先にハンマクラッシャを設置して練合と粗砕の準備をした。
また、ステンレス製塗料タンクに水２２０部を入れ、更にＨＬＢ１２のノニオン系界面活性剤０．２部及び分子量８０万のノニオン系増粘安定剤０．２部を配合し、溶解して水性媒体とした。この水性媒体を循環ポンプで、ディスクグラインダに循環するように設定して湿式粉砕の準備した。
【００５４】
フラッシュミキサーで混合した配合物を２軸スクリューニーダーのフィーダーに供給した。その配合物は、フィーダーより供給された後約２０秒間滞留して溶融練合処理された後、約１２０℃の粘性液体（均質化物）として２軸スクリューニーダーの先端から２本ロール冷却機の圧延ロールに落ち、圧延され、約１０秒で常温近くまで冷却された。この板状の塗料樹脂粒子用原料をハンマクラッシャで約０．５ｍｍの大きさの粗粒子に一次粉砕した。この一次粉砕した粗粒子を、ディスクグラインダに循環している水性媒体中に、ディスクグラインダの入り口直前で連続的に入れ、ディスクグラインダに導入した。ディスクグラインダは、グラインダの間隙２５０μｍ、回転数１２００ｒｐｍで運転し、粗粒子を湿式粉砕処理をした。配合物の溶融練合が終了し、水性媒体中への粗粒子の供給が終了した後、それらの粗粒子及び一部分湿式粉砕された物の全体を更に同一条件でディスクグラインダを通過させて湿式粉砕した。
【００５５】
できた水性分散液を４００メッシュの振動篩を通過させた。篩のステンレス製金網の上には、ほとんど何も残留しなかった。この後、水を若干補充し、防黴剤、消泡剤、粘性付与剤を添加して、不揮発分４５重量％、ＰＨ５．８の水性分散塗料とした。この水性分散塗料中の塗料樹脂粒子径は、粒度分布測定の結果、平均粒子径６μｍであった。
【００５６】
この塗料を、燐酸亜鉛系化成処理した鋼板上に通常のエアースプレー塗装で膜厚５μｍ〜８０μｍの種々の段階的な厚さに塗布し、塗布後、室温で、相対湿度７５％で１０分間放置した。この段階で、塗布膜厚が５μｍ〜５０μｍの塗布膜厚の薄い各々の塗板では、水分は完全に蒸発し、外観上は粉体塗料を極めて緻密に塗布したような状態であった。又、塗布膜厚が７０μｍ以上の塗布膜厚の厚い塗板では、塗板の外周部分は半乾燥状態で艶が引けつつある状態であり、塗膜の中心部分は水分があり艶のある状態であった。これらの塗板を乾燥炉で３分間で１００℃まで昇温させ、その後２分間で１７０℃まで昇温させ、昇温後その温度に２０分間保持して、各種膜厚の塗膜を得た。塗膜外観については、塗布膜厚５μｍの塗板では、多少つながりの不良による凹凸が見られたが、塗布膜厚８μｍ以上８０μｍまでは全く異常は認められず、平滑性のある均一な塗膜であった。この塗膜の光沢値は９０、鉛筆硬度はＨで、デュポン衝撃試験（５００ｇ、３０ｃｍ）も全ての膜厚の塗膜で合格であった。
【００５７】
＜エポキシ／ポリエステル樹脂粉体塗料＞の調製
上記の＜エポキシ／ポリエステル樹脂水性分散粉体塗料＞の調製で用いた水性分散粉体塗料のための添加剤、ノニオン系界面活性剤及びノニオン系増粘安定剤を配合しなかった以外は、上記の＜エポキシ／ポリエステル樹脂水性分散粉体塗料＞の調製の場合と全く同じ原料をスクリューミキサー中で配合し、さらにフラッシュミキサーで均一に混合した。この混合物を、更にエポキシ／ポリエステル樹脂水性分散粉体塗料の粗砕塗料樹脂粒子の調製と同様に２軸スクリューニーダーで溶融練合し、圧延冷却、粗砕した。この粗砕塗料樹脂粒子１００部に流動性改質剤として微粉シリカを０．６部添加し、粉砕機で平均粒子径２５μｍの粉体塗料とした。
【００５８】
この粉体塗料を通常の静電塗装機で、燐酸亜鉛系化成処理した鋼板に膜厚３μｍから１２０μｍまで段階的に塗装し、１７０℃で２０分間保持して、各種膜厚の塗膜を得た。塗膜外観は、塗布膜厚５〜２０μｍの範囲内の塗板では、膜厚が薄くなるに従って多少凹凸になる傾向が見られたが、ピンホール等は無く、良好であった。塗布膜厚５μｍ未満では膜厚が薄くなる程ピンホールの数が多くなった。塗布膜厚２０μｍ〜１２０μｍまでは全く異常は認められず、平滑性のある均一な塗膜であった。
この塗膜の光沢値は９０、鉛筆硬度Ｈで、デュポン衝撃試験（５００ｇ、３０ｃｍ）も全ての膜厚の塗膜で合格であり、塗膜性状は＜エポキシ／ポリエステル樹脂水性分散粉体塗料＞とほぼ同一であった。
【００５９】
＜エポキシ樹脂水性分散粉体塗料＞の調製
エポキシ当量４５０〜５２５、樹脂軟化温度６４〜７６℃のエポキシ樹脂（商品名：エピコート１００１；油化シェル化学（株）製）８３部、２−フェニルイミダゾール１部、テトラハイドロフタリックアンハイドライド１３部、チタン白２１部及びカーボンブラック１部を配合し、＜エポキシ／ポリエステル樹脂粉体塗料＞の調製の場合と同様に溶融練合し、更に、＜エポキシ／ポリエステル樹脂水性分散粉体塗料＞の調製の場合と同様に水媒体、添加剤を加え、後処理をして＜エポキシ樹脂水性分散粉体塗料＞とした。
【００６０】
＜アクリル樹脂粉体塗料＞の調製
メチルメタクレート６０部、ブチルアクリレート６部、グリシジルメタクレート３３部及びアゾイソブチロニトリル１部を均一に溶解して得た溶液を滴下槽に入れた。反応槽にキシロール１００部を仕込み、１２０℃に加温し、攪拌しながら、該滴下槽に入れた溶液を該反応槽に１時間かけて滴下し、２時間保持した。その後、更にアゾイソブチロニトリル０．３部を加え、１５０℃で約４時間保持し、重合反応させて樹脂溶液を得た。薄膜、減圧乾燥機を用いてこの樹脂溶液から溶剤を除去して固形のアクリル樹脂を得た。このアクリル樹脂は軟化温度約５５℃、エポキシ当量４３０、分子量約７０００であった。
【００６１】
このアクリル樹脂７７部、ドデカンジカルボン酸１９部、表面調整剤１部及び流展性付与剤３部を配合し、溶融練合し、粉砕、分級、表面処理をしてアクリル樹脂クリヤー粉体塗料の塗料樹脂粒子を作成した。この塗料樹脂粒子９３部に、アルミニウム顔料（粒子径３０μｍ、アスペクト比約１０）６部をドライブレンドし、更に微粉シリカ１部を追加し、均一に混合して＜アクリル樹脂粉体塗料＞とした。
【００６２】
＜ポリエステル樹脂粉体塗料＞の調製
ポリエステル樹脂（商品名：ファインディックＭ８０２３、大日本インキ化学工業（株）製、軟化温度１１０℃、水酸基価４０）５６部、ブロックイソシアネート樹脂（商品名：ＩＰＤＩ−Ｂ１５３０、ダイセルヒュルス社製）１１部、表面調整剤１部、流展性付与剤２部、酸化チタン２９部及びカーボンブラック１部を配合し、＜エポキシ／ポリエステル樹脂粉体塗料＞の調製の場合と同様に溶融練合し、平均粒子径１５μｍに粉砕し、分級し、更にまた＜エポキシ／ポリエステル樹脂粉体塗料＞の調製の場合と同様に後処理をして＜ポリエステル樹脂粉体塗料＞とした。
【００６３】
＜アクリル樹脂メタリック水性分散粉体塗料＞の調製
前記した＜アクリル樹脂粉体塗料＞の調製で作成したアクリル樹脂粉体塗料の塗料樹脂粒子を用い、前記した＜エポキシ／ポリエステル樹脂水性分散粉体塗料＞の調製の場合と同様に水媒体、添加剤を加え、後処理をしてアクリル樹脂水性分散粉体塗料を作成した。この水性分散粉体塗料９３部にアルミニウム顔料（粒子径３０μｍ、アスペクト比約１０）４部、水３部を加え、均一に混合して＜アクリル樹脂メタリック水性分散粉体塗料＞とした。
【００６４】
実施例１
脱脂、燐酸亜鉛被膜処理したスチール製の内装家具の組立部材の粉体塗料で塗装し難い内部に、前記の＜エポキシ／ポリエステル樹脂水性分散粉体塗料＞を用いてロボットで静電塗装した。この塗装後、塗膜中に一部水分が残っている状態で内装家具を自転搬送しながら、＜エポキシ／ポリエステル樹脂粉体塗料＞を用いて粉体塗料用静電塗装機を上下にレシプロさせて粉体塗装し、外部の膜厚として３０μｍになるように塗装した。
【００６５】
この部材を１７０℃に保持した乾燥炉に搬送し、乾燥炉中で移動させながら、２０分間保持し、その後冷却して製品とした。
この製品の内部も外部も完全に塗装され、塗膜の境界も均一で全く判別ができなかった。また、塗膜性能も前記した＜エポキシ／ポリエステル樹脂水性分散粉体塗料＞を単独で用いた場合の塗膜性能及び＜エポキシ／ポリエステル樹脂水性分散粉体塗料＞を単独で用いた場合の塗膜性能と同様に良好であった。
【００６６】
実施例２
脱脂、燐酸亜鉛被膜処理したスチール製の自動車用鉄ホイールに防錆塗膜として＜エポキシ樹脂水性分散粉体塗料＞を用いて膜厚が１５μｍになるように静電塗装した。特に打ち抜き部分や合わせ目は重点的に塗装して全面塗装した。この防錆層を塗装したホイールの表面部分と裏面の意匠部分だけ、更に＜アクリル樹脂粉体塗料＞でシルバー色にメタリック塗装した。この２層の塗膜を同時に１８０℃３０分間焼付硬化させて製品とした。
【００６７】
このホイールの塗膜性能は、従来の電着塗膜＋溶剤型上塗塗膜の２コート２ベーク方式による塗膜と比較して、塗膜の仕上がり外観、塗膜の耐食性、耐チッピング性等何ら劣る点は無く、むしろ耐腐食性試験においては優れた点が多々あった。また、塗装における生産性については、従来の２コート２ベーク方式に比べて、塗膜の塗装、乾燥時間が約半分になり、エネルギーコスト、生産速度とも大きく改善できた。
【００６８】
実施例３
無処理のアルミニウム板を清浄化し、その上に＜エポキシ樹脂水性分散粉体塗料＞を用いてフローコータで膜厚が１０μｍになるように塗布し、直ちにその上に＜ポリエステル樹脂粉体塗料＞を用いて膜厚が２５μｍになるように静電塗装した。この塗膜を２２０℃１分間加熱して塗膜とした。この塗膜は、平滑性、耐食性とも良好で、ＰＣＭ塗膜として十分に使用可能な製品となった。
【００６９】
実施例４
実施例２と同様に、脱脂、燐酸亜鉛被膜処理したスチール製の自動車用鉄ホイールに防錆塗膜として＜エポキシ樹脂水性分散粉体塗料＞を用いて膜厚が１０μｍになるように静電塗装した。特に打ち抜き部分や合わせ目は重点的に塗装して全面塗装し、水分が５％以下になるように８０℃で５分間プレベークした。この防錆層を塗装したホイールの表面部分と裏面の意匠部分だけ、更に＜アクリル樹脂メタリック水性分散粉体塗料＞を膜厚が３０μｍとなるようにメタリック塗装した。この２層の塗膜を同時に乾燥炉で１００℃まで３分、その後１８０℃まで昇温し、昇温後３０分間焼付硬化させた。仕上がった製品は、シルバー色の均一な色をした良好な外観であった。
【００７０】
比較例１
従来から使用しているスラリー塗料を電着塗装し、該電着塗膜が乾燥する前に前記の＜アクリル樹脂粉体塗料＞、＜ポリエステル樹脂粉体塗料＞、＜エポキシ／ポリエステル樹脂水性分散粉体塗料＞、＜エポキシ／ポリエステル樹脂粉体塗料＞をそれぞれ塗装し、焼付硬化させて４種の塗膜を作製した。
この結果、いずれも塗膜は形成されるが、ピンホールが発生したり、塗膜の平滑性が劣っていた。これは、電着塗膜中にわずかに残留する水分の影響か、あるいは塗膜の硬化性、あるいは電着塗膜がフロー性を持たないことが原因と考えられる。
【００７１】
【発明の効果】
本発明の塗装方法によれば、最初に塗布した塗膜の乾燥状態によらずにその上に次の塗膜を塗装することができ、割れのない、平滑性のある塗膜を形成させることが可能となる。また、例えば、箱物の内部のコーナー部分を前補正塗装し、次いで全体を塗装することや、非導電性素材に導電層を形成し、次いで静電塗装をすることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a powder coating method, and more specifically, a specific dispersion stabilizer is used as the first layer for the purpose of pre-correction or formation of a conductive coating film.Manufactured in a specific wayA coating film having a uniform composition and / or two layers having different compositions by applying a powder coating or an aqueous dispersion powder coating using a specific dispersion stabilizer as the second layer. A coating method for forming a coating film, or an aqueous dispersion powder coating (a) using a specific dispersion stabilizer is partially applied as a pre-correction, and then a powder coating (b) or a specific dispersion stabilizer It is related with the coating method which paints the water-dispersed powder coating material (c) which uses A.
[0002]
[Prior art]
Conventionally, a technique is known in which a water-soluble paint or an organic solvent-type paint is applied as a base and a powder paint or the like is applied thereon to form a coating film. However, in recent years, a coating system that does not use an organic solvent has been required in order to prevent diffusion of the organic solvent into the atmosphere due to environmental problems and the like. As a coating material satisfying this requirement, it has been found that a powder coating material or an aqueous dispersion powder coating material in which a powder coating material is dispersed in water is optimal, and has been developed.
[0003]
A slurry paint prepared by a phase change method is known as a paint very similar to an aqueous dispersion powder paint in which this powder paint is dispersed in water. Preparation of slurry paint by the phase change method is to prepare a solvent-type paint using a water-soluble organic solvent, and forcibly emulsify the solvent-type paint in water to remove the organic solvent, and then remove the organic solvent. It is carried out by creating solid paint resin particles (including not only resin components but also pigments, additives, etc., hereinafter referred to as paint resin particles), and dispersing the paint resin particles in water to form a slurry paint. The That is, in preparing the slurry paint by the phase change method, it is necessary to recover the organic solvent from the water.
[0004]
In addition, there are various problems in applying a slurry paint prepared by the above phase conversion method as a base, and forming a coating film by applying a powder paint or the like thereon. In other words, this slurry paint mainly uses an anionic surfactant or a thickening stabilizer obtained by neutralizing polycarboxylic acid with ammonia or amines to disperse and stabilize paint resin particles. Therefore, when water evaporates from the paint film coated with this slurry paint, the neutralizing agent in the paint also evaporates and scatters. Therefore, once the water evaporates from the paint film, the paint resin particles in the paint film It becomes an anion resin that has lost the neutralizing agent, and has a strong film formed around it by hydrogen bonding due to the carboxyl group of the polycarboxylic acid. Since this coating film is poor in heat softening and is not sticky, the coating resin particles are melted and fused to inhibit the formation of the coating film. For this reason, the coating film was cracked during film formation, or smoothness was insufficient. Therefore, it is necessary to heat up the slurry paint at a stroke after coating, and to form a film at the same time by coating a powder paint on the slurry paint, or at a time interval on the slurry paint. It was not possible to paint and form a film.
[0005]
[Problems to be solved by the invention]
The present invention provides a coating method that does not cause the above-mentioned problems, that is, it is not necessary to use an organic solvent, and it is necessary to apply a stable aqueous dispersion paint manufactured at a low cost. Even if all or part of the coating is applied as a pre-correction or for the purpose of forming a conductive coating, and then a powder coating or water-dispersed powder coating is applied, the coating will crack or become smooth. It is an object of the present invention to provide a coating method for forming a coating film having a uniform composition excellent in coating film performance and / or a two-layer coating film having different compositions without being insufficient.
[0006]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that they are non-volatile and compatible with the coating resin for the dispersion and stabilization of the coating resin particles in the aqueous dispersion powder coating. Nonionic surfactants and / or nonionic thickening stabilizers are used as dispersion stabilizers, and preferably a part or all of the dispersion stabilizers are uniformly contained in the paint resin particles when the paint resin particles are prepared. The present invention has been completed by finding that the above-mentioned problems can be solved by blending and dispersing in the use.
[0007]
That is, the coating method of the powder paint of the present invention, as the first layer as the lower layer,
(1) Various raw materials as coating film components andNonionic surfactant and / or nonionic thickening stabilizerConsist ofDispersion stabilizerMixing to obtain a formulation,
(2) a step of melt-kneading the blend at a temperature equal to or higher than the softening temperature of the resin component to obtain a homogenized product; (3) a step of coarsely crushing the homogenized product after cooling and solidification to obtain coarse particles, and
(4) A step of obtaining an aqueous dispersion powder coating material containing fine particles having an average particle diameter of 10 μm or less by wet-grinding the coarse particles in an aqueous dispersion medium
It was manufactured by carrying out sequentiallyAn aqueous dispersion powder coating (a) is applied, and as a second layer as an upper layer, a powder coating (b) or a nonionic surfactant and / or a nonionic thickening stabilizer is used as a dispersion stabilizer. The dispersion powder paint (c) is coated on the entire surface or on a necessary part.
[0008]
Moreover, the coating method of the powder coating of the present invention, as the first layer as the lower layer,aboveThe aqueous dispersion powder coating (a) is applied, and before the conductivity due to moisture in the coating film disappears after coating, the powder coating (b) or the nonionic surfactant is used as the second layer as the upper layer. An aqueous dispersion powder coating material (c) using a nonionic thickening stabilizer as a dispersion stabilizer is electrostatically coated on the entire surface or a necessary portion.
[0009]
Furthermore, the powder coating method of the present invention comprises:aboveThe aqueous dispersion powder coating (a) is partially applied as a pre-correction, that is, a predetermined part requiring the pre-correction, and then the powder coating (b) or nonionic surfactant and / or nonionic An aqueous dispersion powder coating (c) using a thickening stabilizer as a dispersion stabilizer is applied.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In the coating method of the present invention, the applied aqueous dispersion powder coating (a) and the respective coating resin particles of the powder coating (b) or the aqueous dispersion powder coating (c) are thermally softened or melted by heating. It is necessary to form a uniform coating film. Therefore, the softening temperature of the coating resin particles constituting the aqueous dispersion powder coating or powder coating used in the coating method of the present invention is preferably 10 to 250 ° C, more preferably 30 to 200 ° C.
[0011]
When the softening temperature of the coating resin particles is lower than 10 ° C., the coating resin particles in the aqueous dispersion powder coating tend to aggregate even at the normal storage temperature of the coating even though they are in the aqueous medium. There is. The reason is that the particle diameter of the powder coating resin particles is 100 to 1000 times larger than the size of the coating resin particles in the emulsion coating or the like. The smaller the average particle diameter of the coating resin particles in the aqueous dispersion powder coating, the more stable the aqueous dispersion powder coating can be achieved even with the coating resin particles having a lower softening temperature. However, in this case, since the total surface area of the paint resin particles in the aqueous dispersion powder paint is increased, a large amount of wetting agent such as a surfactant should be present in order to stably disperse the paint resin particles in the aqueous medium. Is required. Therefore, in such a case, performances such as water resistance and gloss of the resulting coating film are deteriorated.
[0012]
Further, when the softening temperature of the coating resin particles exceeds 250 ° C., a temperature exceeding 250 ° C. is necessary for heat curing for forming the coating film, and at such a high temperature, the coating film turns yellow. The coating film is not preferable because it tends to be oxidized with air and lose flexibility. As a special example of a method for preventing such a phenomenon, there is a method of forming a film in an inert gas atmosphere such as carbon dioxide gas. In this case, an apparatus for forming such an inert gas atmosphere is used. Need extra. Further, such a phenomenon tends not to occur when a coating film using an olefin resin or a high molecular weight fluororesin is formed as a resin component.
[0013]
Examples of the resin component of the paint resin particles as described above include alkyd resin, acrylic resin, polyester resin, epoxy resin, melamine resin, block isocyanate resin, fluororesin, silicon resin, amide resin, ABS resin, and the like. These resin components can be used alone or in combination at any blending ratio, if necessary. Further, if necessary, additives such as dibasic acid, polybasic acid, polyamide resin and other curing agents used in ordinary paints, surface conditioners and curing accelerators may be added.
[0014]
In addition to these resins, curing agents, and the like, it is effective to add color pigments, rust preventive pigments, and other additives for imparting other functions as coating film components. These coloring pigments include yellow iron oxide, titanium yellow, red rose, titanium oxide, zinc white, lithopone, lead white, zinc sulfide, antimony oxide and other inorganic pigments, Hansa Yellow 5G, Permanent Yellow FGL, phthalocyanine blue, There are organic pigments such as Indanthrene Blue RS, Permanent Red F5RK, Brilliant First Scarlet G, Paliogen Red 3910 and the like.
[0015]
The amount of these pigments added to the paint resin particles is usually about 0.5 to 60% in terms of PWC, but may not be added at all as in the case of clear paint.
Here, PWC is Pigment Weight Concentration (pigment weight concentration) and is calculated by the following equation.
PWC = [(Contained pigment weight%) / (Total paint solid content weight%)] × 100
[0016]
When these pigments are added in a large amount, particularly when a pigment having a high oil absorption is used, when a coating film is formed using such a paint, the smoothness of the coating film tends to be impaired.
In addition, as an extender, barium sulfate, barium carbonate, calcium carbonate, clay, silica powder, finely divided silicic acid, diatomaceous earth, talc are used for the purpose of adjusting the gloss value of the coating film and adjusting the firmness of the coating film. Basic magnesium carbonate, alumina white and the like can also be added.
[0017]
In the coating method of the present invention, it is possible to carry out a metallic coating comprising forming a metallic paint by adding a glittering flaky pigment in the paint and forming a coating film effective in design using this paint. . As such bright flaky pigments, ordinary aluminum pigments, mica pigments, bronze powders, copper powders, stainless steel powders, metal-coated glass powders, metal-coated mica powders, metal-coated plastic powders, and the like can be used.
[0018]
In the case of the aqueous dispersion powder coating material, the glittering flaky pigment can be contained in the coating resin particles, but preferably it is contained separately from the coating resin particles in the aqueous medium of the aqueous dispersion powder coating material. It is preferable. There are no particular restrictions on the addition method, but the surface of the glittering flaky pigment is made hydrophilic in advance with a water-soluble solvent or surfactant, and if necessary, added in combination with a water-soluble resin or additive. You can also.
These glittering flaky pigments can be contained alone or in combination of two or more. The amount of glittering flaky pigment added to the coating is preferably about 0.05 to 30% by weight of the total solid content.
[0019]
In order to prepare the gloss of the coating film formed by the coating method of the present invention, it is possible to add a matting pigment into the paint. Also, the paint resin particles in the paint can be made into a mixture of two or more types, and the gloss can be adjusted by the compatibility or reaction rate difference between the paint resin particles. As these gloss adjusting agents, colloidal silica, alumina, talc and the like that are usually used in paints can be used.
[0020]
In the aqueous dispersion powder coatings (a) and (c) used in the coating method of the present invention, it is necessary to use a dispersion stabilizer in order to stably disperse the coating resin particles in the aqueous medium. A nonionic surfactant and / or a nonionic thickening stabilizer is used as the dispersion stabilizer.
[0021]
Nonionic surfactants used in the present invention include polyethylene glycol type nonionic surfactants, polyhydric alcohol type nonionic surfactants, etc., and polyethylene glycol type nonionic surfactants include polyethylene glycol type nonionic surfactants. Higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, fatty acid ethylene oxide adduct, higher aliphatic amine ethylene oxide adduct, aliphatic amide ethylene oxide adduct, polypropylene glycol ethylene oxide adduct, and the like. Examples of the polyhydric alcohol type nonionic surfactant include fatty acid ester of glycerin, fatty acid ester of pentaerythritol, fatty acid ester of sorbit, fatty acid ester of sorbitan, fatty acid alkanolamide, and the like.
[0022]
Among these nonionic surfactants, surfactants having an HLB of 7 or more are preferable in order to uniformly wet and disperse the coating resin particles as the aqueous dispersion powder coating. However, it is not preferable to use a surfactant having an HLB of more than 22, since it tends to decrease the performance such as water resistance of the coating film, although it depends on the amount added. More preferably, a surfactant having an HLB of about 8-18 is used.
[0023]
Paint resin particlesOr in paint resin particles andThe total amount of the surfactant added to the aqueous medium is preferably an amount that is about 0.1 to 5% by weight of the weight of the coating resin particles. In this case, if the ratio of the amount added to the coating resin particles is increased, the total amount of surfactant necessary for the entire aqueous dispersion powder coating is reduced to about one half compared to the case where it is added only to the aqueous medium. It is possible to obtain a wetness and dispersibility equivalent to or higher than that in the case of adding only in an aqueous medium with the addition amount of about a half. For this reason, it is possible to form a coating film having good coating film performance, particularly water resistance and gloss.
[0024]
In addition, examples of the nonionic thickening stabilizer include polyethylene glycol type thickening stabilizers, and a thickening stabilizer having a large molecular weight is preferable in terms of thickening stability. However, when the molecular weight is 1 million or more, the storage stability of the aqueous dispersion powder coating is good, but in the method of atomizing and coating as in air spray coating, etc., a tendency to generate a stringing phenomenon during coating However, roll coating and flow coating are preferable because the paint followability and film formability are good, as in the case of pre-coating metal coating.
[0025]
Paint resin particlesOr in paint resin particles andThe total amount of nonionic thickening stabilizer added to the aqueous medium is usually the case of water-dispersed powder coatings used for air spray coating, electrostatic coating, airless coating, and rotary atomizing electrostatic coating. When about 100,000 nonionic thickening stabilizer is used, the amount is preferably about 0.3 to 5% by weight of the weight of the coating resin particles. In the case of an aqueous dispersion powder coating used for roll coating or flow coating, when a nonionic thickening stabilizer having a molecular weight of several hundreds of thousands to 2 million is used, the weight of the coating resin particles is reduced to 0. It is preferable that the amount be about 1 to 5% by weight.
[0026]
The aqueous dispersion powder coating used in the present invention can also be produced by a method in which the above dispersion stabilizer is dissolved in an aqueous medium and the raw material of the coating resin particles is wet pulverized therein. However, in this method, the concentration of the dispersion stabilizer adsorbed on the surface of the paint resin particles is different between the initial stage and the end of the wet grinding, and particularly at the end point of the wet grinding where the total surface area of the paint resin particles increases, the surface of the paint resin particles The dispersion stabilizer particles adsorbed on the surface of the resin particles are not preferable because they tend to aggregate.
[0027]
When producing the aqueous dispersion paint used in the present invention, it is preferable that a part or all of these dispersion stabilizers are mixed together with the coating film components, and uniformly dispersed in the paint resin by melt kneading. Let When this paint resin is cooled and solidified and then coarsely crushed, and the coarse particles are wet pulverized in an aqueous dispersion medium, the dispersion stabilizer always appears uniformly on the surface of the paint resin particles newly generated by this pulverization. Becomes hydrophilic. As a result, even if the paint paint resin particles are finely wet pulverized to increase the surface area, the wettability and thickening stability of the paint resin particles are kept constant. Furthermore, the finer the coating resin particles, the easier it is to aggregate, but in the case of coating resin particles containing a dispersion stabilizer, the surface properties of the coating resin particles are always constant and uniform as described above. The paint resin particles are stably dispersed in the aqueous dispersion paint. Therefore, in this case, as described above, the total amount of the surfactant necessary for the entire aqueous dispersion powder coating is reduced to about one half as compared with the case where the dispersion stabilizer is added only in the aqueous medium. Wet and dispersibility equivalent to or higher than when added only to the medium can be obtained, so there is no uneven distribution because the amount of the dispersion stabilizer is reduced and it is uniformly dispersed. The performance is also good. However, the biggest difference is that there is no pH dependency of the coating material, and even if the pH is about 3 lower than the neutralization point, coating and film formation can be performed without any trouble.
[0028]
In the coating method of the present invention, a nonionic surfactant and / or a nonionic thickening stabilizer is used as a dispersion stabilizer.useTherefore, since these dispersion stabilizers do not use a neutralizing agent, the thermal softening property and fluidity of the coating resin particles are not significantly changed even by evaporation of water after coating. Therefore, after the aqueous dispersion powder coating is applied, whether the coating film is in a wet state or in a completely dry state, the powder coating or the aqueous dispersion powder coating is applied to the coating and heated. Can be made into a membrane.
[0029]
Since the aqueous dispersion powder coating used in the coating method of the present invention has the above characteristics, the above aqueous dispersion powder coating is applied as the first layer and the powder coating is used as the second layer for the purpose of pre-correction. Alternatively, the above-mentioned aqueous dispersion powder coating is applied as the first layer and the powder coating is applied as the second layer for the purpose of coating an aqueous dispersion powder coating or forming a conductive coating on a non-conductive material. Alternatively, the aqueous dispersion powder coating can be electrostatically coated to form a uniform coating and / or two coatings with different compositions.
[0030]
For example, when the inside of a box is coated with a powder paint, the film thickness of the corner portion tends to be thin due to airflow and electric potential. By pre-correcting such a corner portion with an aqueous dispersion powder paint in advance, and then applying a powder paint, the corner portion can be reliably applied. That is, it is possible to apply the aqueous dispersion powder paint partially as a pre-correction, that is, to a predetermined portion that requires the pre-correction, and then apply the powder paint or the aqueous dispersion powder paint.
[0031]
In the coating method of the present invention, as a matter of course, it is also possible to finish by painting only with the aqueous dispersion powder paint. On the other hand, the composition of the coating resin particles used for the aqueous dispersion powder coating (a) to be applied as the first layer, and the powder coating (b) or the aqueous dispersion powder coating (c) to be applied as the second layer. The composition of the coating resin particles used in the above may be the same composition, a similar composition, or a completely different composition. When the composition of the paint resin particles of the aqueous dispersion powder paint to be applied to the first layer is different from the composition of the paint resin particles of the powder paint or the aqueous dispersion powder paint to be applied to the second layer, Alternatively, a coating film having a different resin composition in layers can be easily formed.
[0032]
<Method for Producing Aqueous Dispersion Powder Coating (a) and (c)>
Aqueous dispersion powder coating used in the present invention(A),
(1) Various raw materials used as coating film componentsAnd a dispersion stabilizer comprising a nonionic surfactant and / or a nonionic thickening stabilizerMixing to obtain a formulation,
(2) a step of melt kneading the blend at a temperature equal to or higher than the softening temperature of the resin component to obtain a homogenized product, (3) a step of obtaining coarse particles by crushing the homogenized product after cooling and solidification, and
(4) A step of obtaining an aqueous dispersion powder coating material containing fine particles having an average particle diameter of 10 μm or less by wet-grinding the coarse particles in an aqueous dispersion medium
Can be manufactured by sequentially carrying outThe aqueous dispersion powder coating (c) can be produced by mixing a dispersion stabilizer comprising a nonionic surfactant and / or a nonionic thickening stabilizer in the step (1) or (4).The
[0033]
Step (1) above, that is, a step of obtaining a blend by mixing various raw materials as coating film components, Or a process of obtaining a blend by mixing various raw materials as coating film constituents and a dispersion stabilizer comprising a nonionic surfactant and / or a nonionic thickening stabilizerIn the case of solid resin raw materials, coloring pigments, curing agents, additives,Dispersion stabilizer,If necessary, a small amount of liquid raw material is mixed as homogeneously as possible.
As a device for this purpose, a flash mixer, a screw mixer, a conical blender, a V mixer, a tumbling mixer, a jet mixer, a kneader, a ribbon mixer, etc., which are ordinary devices for mixing powder raw materials can be used.
It is preferable to mix and blend the raw materials using these devices and make them as homogeneous as possible. However, when the total amount of the raw materials is small, the raw materials are simply mixed in a bag and the next melt-kneaded. It can also be made homogeneous in the combined process. In particular, if a part or all of the dispersion stabilizer that functions to easily disperse the coating resin particles in the aqueous medium is added in this mixing and blending step, the coating resin particles are newly added in the subsequent wet pulverization step. Since the pulverized surface to be produced is equally hydrophilic, the aqueous dispersion powder coating can be easily produced.
[0034]
Next, the step (2), that is, the step of obtaining a homogenized product by melt-kneading the blend at a temperature equal to or higher than the softening temperature of the resin component is performed. The purpose of this step is to uniformly mix a solid resin raw material, a coloring pigment, a curing agent, an additive, and the like, which are raw materials of the coating resin particles, to the order of several μm or less. The resin raw material and curing agent of the aqueous dispersion powder coating used in the present invention are processed into pellets of several millimeters for the purpose of facilitating handling during transportation and blending and preventing dust from rising. ing. The pellets are crushed into a mixture of particles of about several hundreds of μm, and this is heated above the softening temperature of the resin component and mechanically kneaded.
[0035]
Examples of the apparatus used for the kneading include a roll mill, a screw kneader, a Mahler, and a kneader. Particularly preferred apparatuses are a roll mill and a screw kneader in terms of workability and ease of handling. These apparatuses are preferable in that the kneaded material can be quickly discharged from the apparatus and cooled after melt-kneading. In particular, in the case of a cross-linked aqueous dispersion powder coating material, a curing agent is contained in the coating resin particles, and thus the resin component, the curing agent, and the like are homogeneously mixed in this melt-kneading process. Since it is heated above the softening temperature of the component, if the residence time when kneading becomes long, a part of the resin component reacts with the curing agent, and as a result, it does not become smooth when forming a coating film, There is a tendency to produce defects with insufficient gloss. Therefore, it is preferable to use an apparatus that supplies from one direction and continuously discharges from the other.
[0036]
Next, the step (3), that is, a step of coarsely crushing the homogenized product after cooling and solidification to obtain coarse particles. In this process, the homogenized paint resin formed in the previous melt-kneading process becomes a lump when cooled and solidified as it is, so that the pre-process for making the coarse particles easy to process in the next wet pulverization process It is. Examples of the apparatus for crushing include a ring roll mill, an edge runner, a roll crusher, a disintegrator, a hammer crusher, an impeller breaker, a gyratory crusher, and a jaw crusher.
[0037]
Next, the step (4), that is, the step of obtaining an aqueous dispersion powder coating material containing fine particles having an average particle diameter of 10 μm or less by wet-grinding the coarse particles in an aqueous dispersion medium will be described.
First of all, the required amount of water is prepared in a tank that receives the aqueous dispersion powder coating. If necessary, a surfactant for wetting the coating resin particles, a suspending agent, and the like are added to the water and mixed to make homogeneous. This aqueous medium is circulated to the wet pulverizer by a circulation pump. The intake port for the coarse particles is provided on the inlet side of the wet pulverizer in this circulation path. The coarse particles taken in here may be mixed in an aqueous medium by their own weight and then enter a wet pulverizer, or may be wetted by some stirring mixer and then taken into a wet pulverizer. Good.
[0038]
What is important in this case is that a sufficient amount of an aqueous medium can be circulated in the wet pulverizer to sufficiently cool the apparatus and carry the pulverized fine particles. In the initial stage after the start of pulverization, the concentration of the coating resin particles in the circulating aqueous medium is low, and therefore the viscosity of the aqueous coating resin particle-containing aqueous medium is low. When the coarse pulverization of the coarse particles proceeds and the circulation of the aqueous medium is repeated, the concentration of the coating resin particles in the circulating aqueous medium becomes high, so that circulation and cooling become increasingly difficult. If the circulation of the aqueous medium stops, there is a risk that the coarse particles supplied into the circulating aqueous medium and the circulating paint resin particles melt by the grinding energy in the wet pulverizer and stick to the inner surface of the apparatus. . For this reason, it is important to set the coating resin particle concentration and fluidity in the target aqueous dispersion powder coating material, and to control the circulation amount and temperature of the aqueous dispersion powder coating material. Normally, the circulation rate can be easily managed, but the temperature rapidly increases as the circulation rate decreases, so the supply amount of coarse particles and the circulation rate of the aqueous medium, the concentration of paint resin particles in the final aqueous dispersion powder coating, etc. Need to be well managed.
[0039]
Next, an example of a wet pulverizer that can be used in this wet pulverization step will be described. Usable wet pulverizers include a disc grinder, a tower mill, a ball mill, a vibration mill, an edge runner, and a roll mill. In a wet pulverizer using a dispersed media such as a tower mill, a ball mill, and a vibration mill, if the size of the coarse particles supplied is larger than the particle size of the media, the efficiency of wet pulverization is significantly reduced. Therefore, in the case of a wet pulverizer using a dispersed media, it is necessary to supply coarse particles sufficiently smaller than the particle size of the media. In wet grinders that pulverize coarse particles in a rotating body such as a disc grinder or roll mill, it is easy to grind even large coarse particles, but the circulation amount of the aqueous medium to be moistened is insufficient, If it is partially biased, the paint resin particles tend to be fused by heat generation.
[0040]
As the operation mode of the wet pulverizer, it is easy to manage if the coating resin particle concentration is maintained at a low concentration. Therefore, if necessary, the coating resin particles can be used using a centrifugal filter, a centrifuge, a decanter, etc. It is preferable to adjust the concentration. For wet pulverization treatment, the paint resin particles can be passed through the wet pulverizer several times until the particle size of the paint resin reaches a certain size, or the paint resin particles of a certain size or larger can be separated with a filter or centrifugal classifier. It can also be removed. After the coating resin particle concentration is adjusted to a predetermined concentration, additives such as an antifungal agent, an antifoaming agent and a viscosity imparting agent are added as a post-adjustment to obtain an aqueous dispersion powder coating material.
[0041]
The finished aqueous dispersion powder coating material has an average particle size of the coating resin particles dispersed therein of 10 μm or less and a content concentration of about 20 to 60% by weight.
The important feature here is that it is wet-pulverized directly in an aqueous medium to form a paint, and if necessary, an aqueous surfactant or aqueous thickener for dispersion in water in advance in various raw materials that are constituents of the coating film. Since part or all of the stabilizer is added, the coating resin particles are easily wetted, dispersed and stabilized in the aqueous medium. As a result, compared to slurry paints prepared by conventional phase change methods and aqueous dispersion powder paints obtained by wetting fine particles obtained by further finely pulverizing powder paints in an aqueous medium, dispersion stabilizers An aqueous dispersion powder coating of paint resin particles having a small required amount and a small particle diameter can be easily prepared.
[0042]
<Production method of powder paint>
The powder paint (b) used in the present invention is:
(1) A step of mixing a raw material to be a coating film component to obtain a blend,
(2) a step of melt-kneading the blend at a temperature equal to or higher than the softening temperature of the resin component to obtain a homogenized product;
(3) A step of coarsely crushing the homogenized product after cooling and solidification to obtain coarse particles,
(4) a step of wet-pulverizing the coarse particles in an aqueous dispersion medium to obtain an aqueous dispersion containing fine particles having an average particle size of 10 μm or less; and
(5) Step of dehydrating the aqueous dispersion to obtain a powder coating material
Can be manufactured by sequentially carrying out.
[0043]
Since the steps (1) to (4) are the same as the steps (1) to (4) of the method for producing an aqueous dispersion powder coating material, the description thereof is omitted.
Step (5) above, that is, the step of dehydrating the aqueous dispersion to obtain a powder coating, is a cake press such as a filter press, leaf filter, rotary filter, centrifugal filter, centrifugal separation It is carried out by dehydrating using a machine and drying. Since the coating resin fine particles are aggregated by such dehydration and drying, crushing is performed after drying to obtain a powder coating.
[0044]
In the powder coating method of the present invention, the aqueous dispersion powder coating (a) is partially applied as the first layer or as a pre-correction. As this coating method, a normal coating method employed for water-based paints can be adopted, and examples thereof include air spray coating, electrostatic coating, dip coating, brush coating, roll coating and flow coating. .
[0045]
In the aqueous dispersion powder coating material (a), when it is applied and not yet dried, moisture inside the coating film can freely move between the coating resin particles by capillary action. As the water evaporates on the surface of the coating film while water is present, the water inside the coating film freely moves between the coating resin particles to the coating film surface by capillary action. This movement speed is sufficiently high even at the end of the drying process, and is considerably higher than the rate at which water is supplied to the surface by diffusion inside the coating film in the case of water-soluble resin paints and emulsion paints. Evaporates at a constant and faster rate than the surface. For this reason, internal water boils by heating, and pinholes are rarely formed. For this reason, it is not necessary to use a high-boiling solvent for adjusting the boiling point, and the VOC of the coating is extremely small, so that the aqueous dispersion powder coating is usually 1% or less.
[0046]
Coating film formation by using the aqueous dispersion powder coating material (a),
(A) Moisture evaporation step, paint resin particle layer forming step,
(B) Melting and fusing process of paint resin particles
After that, a continuous coating film is formed.
[0047]
The above processes are heated with emulsion paint or water-soluble paint, and it is not necessary to control the process strictly to the extent necessary for the film formation process, but if the film thickness is thick, pinholes due to boiling of water In order to prevent the occurrence of this, it is preferable to pay attention to the management of the heating rate. The above steps (A) and (B) may be carried out continuously with no time between those steps, or may be carried out stepwise with time. Even if it carries out stepwise with time between the above-mentioned (A) process and (B) process, that is, after coating, it is allowed to stand at room temperature, and after arbitrary time has passed, it is heated to form a film. However, cracks that occur in the case of a coating using a conventional anionic additive do not occur in the coating film. The coating film left at room temperature for a long period of time is formed through a film forming process in almost the same state as when the water is evaporated, the coating resin particles are deposited, and the powder coating is applied.
[0048]
Powder coating after coating of the first layer or after partial coating as pre-correction, as a second layer or as a finishing layer for portions without pre-correction (hereinafter collectively referred to as the second layer) (B) Or the aqueous dispersion powder coating material (c) is applied.
As the coating method of the second layer, a normal coating method can be adopted, and as the powder coating (b), for example, electrostatic coating can be exemplified. Examples of the aqueous dispersion powder coating (c) include air spray coating, electrostatic coating, dip coating, brush coating, roll coating, and flow coating.
[0049]
In the powder coating method of the present invention, the second layer can be applied regardless of the dry state of the first layer coating. That is, it is possible to apply the second layer immediately after coating the first layer or after standing for a while and then cure and film the first layer and the second layer at the same time. It is also possible to coat, cure, and form the second layer after coating, curing, and forming the film. Therefore, the aqueous dispersion powder paint (a) is applied as the first layer, and before the conductivity due to moisture disappears after the coating, the powder paint (b) or the aqueous dispersion powder paint is used as the second layer. It is also possible to electrostatically coat (c).
[0050]
In the powder coating method of the present invention, since the coating resin particles are adhered to the object to be coated with water by a strong force such as an adsorbing force, it falls even in the case of an object having a weak adhesion such as plastic. There is nothing. Therefore, the standing time after painting is arbitrary, but considering the adhesion of dust, the effective length of the painting line, storage location, etc., the film can be dried and heated as soon as possible after coating to form a film. preferable.
[0051]
In the case of forming a film in a short time, the object to be coated is heated up to 100 ° C. which is the boiling temperature of water when entering the melting and fusing process of the coating resin particles in the coating film forming process (B). It is preferable to take a time of 20 seconds or longer. Usually, the temperature is increased at a heating rate such that the time to reach 100 ° C. is about 1 to 3 minutes, and when the temperature exceeds 100 ° C., the temperature is arbitrarily increased to a predetermined reaction temperature and maintained at that temperature. To form a crosslinked film. Therefore, there is no need for the step of heating at 80 to 100 ° C. for 5 to 10 minutes, and then heating to a predetermined temperature and curing, which is required when heating and forming the emulsion paint or water-soluble paint.
[0052]
【Example】
Next, the present invention will be described in more detail with reference to examples and comparative examples. In the following description, “parts” indicates parts by weight.
Preparation of <epoxy / polyester resin aqueous dispersion powder coating>
Softening temperature 120 ° C, acid resin 45 polyester resin 32 parts, epoxy equivalent 910 bisphenol A type epoxy resin 32 parts, titanium pigment 25 parts, carbon black 0.1 part, other iron oxide pigment 0.1 parts, surface 6 parts of conditioning agent, 2 parts of ultraviolet absorber, 1 part of antioxidant, 1 part of curing accelerator, 0.8 part of nonionic surfactant of HLB12, and 0.8 part of nonionic thickening stabilizer having a molecular weight of 300,000 Were blended in a screw mixer and mixed uniformly with a flash mixer.
[0053]
On the other hand, a twin screw kneader is used as a melt kneader, heated to 115 ° C, a two-roll cooler for rolling cooling is installed at the tip of the melt kneader, and a hammer crusher is installed at the tip. Then we prepared for kneading and crushing.
Further, 220 parts of water is put into a stainless steel paint tank, and further 0.2 part of a nonionic surfactant of HLB12 and 0.2 part of a nonionic thickening stabilizer having a molecular weight of 800,000 are blended and dissolved to form an aqueous medium. did. This aqueous medium was set to circulate to a disc grinder with a circulation pump to prepare for wet grinding.
[0054]
The blended mixture with a flash mixer was fed to the feeder of a twin screw kneader. The blend is supplied from the feeder, stayed for about 20 seconds, melt-kneaded, and then rolled as a viscous liquid (homogenized product) at about 120 ° C. from the tip of the twin screw kneader. It fell on a roll, rolled, and cooled to near room temperature in about 10 seconds. This raw material for plate-like paint resin particles was first pulverized into coarse particles having a size of about 0.5 mm with a hammer crusher. The coarsely pulverized primary particles were continuously put in an aqueous medium circulating in the disc grinder immediately before the entrance of the disc grinder and introduced into the disc grinder. The disc grinder was operated with a grinder gap of 250 μm and a rotational speed of 1200 rpm, and the coarse particles were subjected to wet grinding. After the melt-kneading of the compound is completed and the supply of the coarse particles into the aqueous medium is completed, the coarse particles and the whole of the partially wet pulverized product are further passed through a disc grinder under the same conditions and wet pulverized. did.
[0055]
The resulting aqueous dispersion was passed through a 400 mesh vibrating screen. Almost nothing remained on the stainless steel mesh of the sieve. Thereafter, water was slightly replenished, and an antifungal agent, an antifoaming agent, and a viscosity imparting agent were added to obtain an aqueous dispersion paint having a nonvolatile content of 45% by weight and a pH of 5.8. The particle diameter of the paint resin in this aqueous dispersion paint was 6 μm as a result of particle size distribution measurement.
[0056]
This paint is applied on a steel sheet subjected to chemical conversion treatment with zinc phosphate to various stepwise thicknesses of 5 μm to 80 μm by ordinary air spray coating. After coating, the coating is left at room temperature for 10 minutes at a relative humidity of 75%. did. At this stage, each coating plate having a coating thickness of 5 μm to 50 μm with a thin coating thickness evaporated water completely, and the appearance was such that the powder coating was applied very densely. In addition, in a thick coated plate having a coating thickness of 70 μm or more, the outer peripheral portion of the coated plate is in a semi-dry state and is being glossed, and the central portion of the coating film is moisture and glossy. It was. These coated plates were heated up to 100 ° C. in 3 minutes in a drying furnace, then heated up to 170 ° C. in 2 minutes, and held at that temperature for 20 minutes after the temperature rising to obtain coating films having various film thicknesses. As for the appearance of the coating film, unevenness due to poor connection was observed on the coated film having a coating film thickness of 5 μm, but no abnormality was observed up to a coating film thickness of 8 μm to 80 μm, and it was a smooth and uniform coating film. there were. The gloss value of this coating film was 90, the pencil hardness was H, and the DuPont impact test (500 g, 30 cm) also passed the coating film of all film thicknesses.
[0057]
Preparation of <epoxy / polyester resin powder coating>
The above except that the additive for the aqueous dispersion powder coating used in the preparation of the above <epoxy / polyester resin aqueous dispersion powder coating>, the nonionic surfactant and the nonionic thickening stabilizer were not blended. <Epoxy / polyester resin water-dispersed powder coating material> The same raw materials as those in the preparation of <Epoxy / polyester resin aqueous dispersion powder coating material> were blended in a screw mixer and further mixed uniformly with a flash mixer. This mixture was further melt-kneaded with a twin screw kneader in the same manner as in the preparation of the coarsely pulverized paint resin particles of the epoxy / polyester resin aqueous dispersion powder paint, and then cooled and coarsely crushed. 0.6 parts of finely divided silica as a fluidity modifier was added to 100 parts of the coarsely pulverized paint resin particles, and a powder paint having an average particle diameter of 25 μm was obtained using a pulverizer.
[0058]
This powder coating is applied in a stepwise manner from 3 μm to 120 μm in thickness on a steel sheet that has been subjected to a zinc phosphate conversion treatment using a normal electrostatic coating machine, and kept at 170 ° C. for 20 minutes to obtain coatings of various thicknesses. It was. As for the appearance of the coating film, the coating plate having a coating thickness in the range of 5 to 20 μm showed a tendency to become somewhat uneven as the thickness decreased, but it was good with no pinholes. When the coating film thickness was less than 5 μm, the number of pinholes increased as the film thickness decreased. No abnormalities were observed at coating thicknesses of 20 μm to 120 μm, and the coating film was smooth and uniform.
The gloss value of this coating film is 90, the pencil hardness is H, and the DuPont impact test (500 g, 30 cm) also passes the coating film of all film thicknesses, and the coating film properties are <epoxy / polyester resin aqueous dispersion powder coating material> It was almost the same.
[0059]
Preparation of <epoxy resin aqueous dispersion powder paint>
Epoxy resin having an epoxy equivalent of 450 to 525 and a resin softening temperature of 64 to 76 ° C. (trade name: Epicoat 1001; manufactured by Yuka Shell Chemical Co., Ltd.) 83 parts, 2-phenylimidazole 1 part, tetrahydrophthalic anhydride 13 parts In addition, 21 parts of titanium white and 1 part of carbon black were blended and melt-kneaded in the same manner as in the preparation of <epoxy / polyester resin powder paint>, and further, <epoxy / polyester resin aqueous dispersion powder paint> was prepared. In the same manner as above, an aqueous medium and additives were added, and post-treatment was performed to obtain <epoxy resin aqueous dispersion powder coating material>.
[0060]
<Acrylic resin powder coating> preparation
A solution obtained by uniformly dissolving 60 parts of methyl methacrylate, 6 parts of butyl acrylate, 33 parts of glycidyl methacrylate and 1 part of azoisobutyronitrile was placed in a dropping tank. The reaction vessel was charged with 100 parts of xylol, heated to 120 ° C., and stirred, the solution placed in the dropping vessel was dropped into the reaction vessel over 1 hour and held for 2 hours. Thereafter, 0.3 part of azoisobutyronitrile was further added, and kept at 150 ° C. for about 4 hours, followed by polymerization reaction to obtain a resin solution. The solvent was removed from the resin solution using a thin film and a vacuum dryer to obtain a solid acrylic resin. This acrylic resin had a softening temperature of about 55 ° C., an epoxy equivalent of 430, and a molecular weight of about 7000.
[0061]
This acrylic resin 77 parts, 19 parts of dodecanedicarboxylic acid, 1 part of a surface conditioner and 3 parts of a flowability imparting agent were blended, melt-kneaded, pulverized, classified, and surface-treated to prepare an acrylic resin clear powder coating material. Paint resin particles were prepared. To 93 parts of the coating resin particles, 6 parts of an aluminum pigment (particle diameter 30 μm, aspect ratio of about 10) was dry blended, and further 1 part of fine silica was added and mixed uniformly to make <acrylic resin powder coating>. .
[0062]
<Polyester resin powder coating> preparation
Polyester resin (trade name: Finedick M8023, manufactured by Dainippon Ink & Chemicals, Inc., softening temperature 110 ° C., hydroxyl value 40), 56 parts, blocked isocyanate resin (trade name: IPDI-B1530, manufactured by Daicel Huls) 11 Part, surface conditioning agent 1 part, flowability imparting agent 2 parts, titanium oxide 29 parts and carbon black 1 part, and melt-kneaded in the same manner as in the case of <epoxy / polyester resin powder coating> The mixture was pulverized to an average particle size of 15 μm, classified, and further post-treated in the same manner as in the preparation of <epoxy / polyester resin powder coating material> to obtain <polyester resin powder coating material>.
[0063]
Preparation of <acrylic resin metallic aqueous dispersion powder coating>
Using the paint resin particles of the acrylic resin powder coating prepared in the preparation of <Acrylic resin powder coating> as described above, an aqueous medium and addition as in the preparation of <epoxy / polyester resin aqueous dispersion powder coating> An acrylic resin aqueous dispersion powder coating material was prepared by adding an agent and post-processing. To 93 parts of this aqueous dispersion powder coating material, 4 parts of an aluminum pigment (particle diameter 30 μm, aspect ratio of about 10) and 3 parts of water were added and mixed uniformly to make <acrylic resin metallic aqueous dispersion powder coating material>.
[0064]
Example 1
The interior of the steel interior furniture assembly member, which has been degreased and coated with zinc phosphate, is difficult to paint with powder paint, and was electrostatically coated with a robot using the above-described <epoxy / polyester resin aqueous dispersion powder paint>. After this coating, the electrostatic coating machine for powder coating is reciprocated up and down using <epoxy / polyester resin powder coating> while rotating and transporting interior furniture with some moisture remaining in the coating film. Then, it was coated with powder so that the external film thickness was 30 μm.
[0065]
This member was transported to a drying furnace maintained at 170 ° C., held for 20 minutes while being moved in the drying furnace, and then cooled to obtain a product.
The inside and outside of this product were completely painted, and the boundary of the coating was uniform and could not be discriminated at all. Moreover, the coating film performance when the above-described <epoxy / polyester resin aqueous dispersion powder coating material> is used alone and the coating film performance when <epoxy / polyester resin aqueous dispersion powder coating material> is used alone. It was as good as the performance.
[0066]
Example 2
A steel automobile steel wheel treated with degreasing and zinc phosphate coating was electrostatically coated so as to have a film thickness of 15 μm using <epoxy resin aqueous dispersion powder coating material> as an anticorrosive coating. In particular, the punched parts and seams were painted with a focus on the entire surface. Only the front surface portion and the back surface design portion of the wheel coated with this rust preventive layer were further metallic-coated in silver with <acrylic resin powder coating>. This two-layer coating film was simultaneously baked and cured at 180 ° C. for 30 minutes to obtain a product.
[0067]
The coating performance of this wheel is similar to that of the conventional electrodeposition coating + solvent-type top coating coating by the 2-coat 2-bake method, such as the finished appearance of the coating, the corrosion resistance of the coating, and the chipping resistance. There were no inferior points, but rather many excellent points in the corrosion resistance test. As for productivity in coating, compared with the conventional 2-coat 2-bake method, the coating and drying time of the coating film was reduced to about half, and both the energy cost and the production speed were greatly improved.
[0068]
Example 3
Clean the untreated aluminum plate, and apply <Epoxy resin aqueous dispersion powder paint> on it with a flow coater to a film thickness of 10 [mu] m, and immediately apply <Polyester resin powder paint> on it. The film was electrostatically coated so that the film thickness was 25 μm. This coating film was heated at 220 ° C. for 1 minute to form a coating film. This coating film had good smoothness and corrosion resistance, and became a product that could be used sufficiently as a PCM coating film.
[0069]
Example 4
In the same manner as in Example 2, electrostatic coating was performed using a <epoxy resin water-dispersed powder coating material> as a rust-preventing coating on a steel automobile wheel that was degreased and treated with a zinc phosphate coating so that the film thickness became 10 μm. did. In particular, the punched portions and seams were preferentially applied and the entire surface was applied, and prebaked at 80 ° C. for 5 minutes so that the water content was 5% or less. Only the front and back design portions of the wheel coated with the rust preventive layer were further coated with <acrylic resin metallic aqueous dispersion powder coating material> so that the film thickness was 30 μm. The two-layer coating film was simultaneously heated to 100 ° C. for 3 minutes and then to 180 ° C. in a drying oven, and baked and cured for 30 minutes after the temperature increase. The finished product had a good appearance with a uniform silver color.
[0070]
Comparative Example 1
Previously used slurry paints are electrodeposited and before the electrodeposition coating is dried, the above <acrylic resin powder paint>, <polyester resin powder paint>, <epoxy / polyester resin aqueous dispersion powder> Body coating> and <epoxy / polyester resin powder coating> were applied and baked and cured to prepare four types of coating films.
As a result, although a coating film was formed in all cases, pinholes were generated or the smoothness of the coating film was inferior. This is considered to be due to the influence of moisture slightly remaining in the electrodeposition coating film, the curability of the coating film, or the electrodeposition coating film having no flowability.
[0071]
【The invention's effect】
According to the coating method of the present invention, the next coating film can be applied on the first coating film regardless of the dry state of the coating film, and a smooth coating film without cracks can be formed. Is possible. Further, for example, the corner portion inside the box can be pre-corrected and then entirely coated, or a conductive layer can be formed on a non-conductive material, and then electrostatic coating can be performed.
Claims (7)
（２）該配合物を樹脂成分の軟化温度以上の温度で溶融練合して均質化物を得る工程、 （３）該均質化物を冷却固化後に粗砕して粗粒子を得る工程、及び
（４）該粗粒子を水性分散媒中で湿式粉砕して平均粒子径が１０μｍ以下の微粒子を含む水性分散粉体塗料を得る工程
を順次実施することにより製造された水性分散粉体塗料（ａ）を第１層として塗装し、第２層として、粉体塗料（ｂ）又は、ノニオン系界面活性剤及び／又はノニオン系増粘安定剤を分散安定剤として使用した水性分散粉体塗料（ｃ）を塗装することを特徴とする粉体塗料の塗装方法。 (1) A step of obtaining a blend by mixing various raw materials as coating film constituents and a dispersion stabilizer comprising a nonionic surfactant and / or a nonionic thickening stabilizer ,
(2) a step of melt kneading the blend at a temperature equal to or higher than the softening temperature of the resin component to obtain a homogenized product, (3) a step of obtaining coarse particles by crushing the homogenized product after cooling and solidification, and
(4) A step of obtaining an aqueous dispersion powder coating material containing fine particles having an average particle diameter of 10 μm or less by wet-grinding the coarse particles in an aqueous dispersion medium
The aqueous dispersion powder coating (a) produced by sequentially carrying out the above is applied as the first layer, and the powder coating (b) or the nonionic surfactant and / or the nonionic thickening is used as the second layer. A method for coating a powder paint, characterized in that an aqueous dispersion powder paint (c) using a stabilizer as a dispersion stabilizer is applied.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02736199A JP4111295B2 (en) | 1999-02-04 | 1999-02-04 | How to apply powder paint |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02736199A JP4111295B2 (en) | 1999-02-04 | 1999-02-04 | How to apply powder paint |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000225371A JP2000225371A (en) | 2000-08-15 |
| JP4111295B2 true JP4111295B2 (en) | 2008-07-02 |
Family
ID=12218920
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP02736199A Expired - Fee Related JP4111295B2 (en) | 1999-02-04 | 1999-02-04 | How to apply powder paint |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4111295B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7025856B2 (en) | 2017-07-31 | 2022-02-25 | 株式会社キッツ | Electric actuator with regenerative braking circuit, electric rotary valve for emergency shutoff valve, and emergency shutoff system |
-
1999
- 1999-02-04 JP JP02736199A patent/JP4111295B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7025856B2 (en) | 2017-07-31 | 2022-02-25 | 株式会社キッツ | Electric actuator with regenerative braking circuit, electric rotary valve for emergency shutoff valve, and emergency shutoff system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2000225371A (en) | 2000-08-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20090136737A1 (en) | Powder coating materials | |
| WO2001059016A1 (en) | Process for preparing an aqueous powder coating dispersion | |
| JP4214318B2 (en) | Granulated powder paint and method for producing the same | |
| CN101248145B (en) | Process for preparing a powder coating composition | |
| JPH11343432A (en) | Production of aqueous disperse coating material and production of powder coating material | |
| JPH0598193A (en) | Powder coating and its raw material | |
| JP2002235038A (en) | Powder coating material composition dispersed in nonaqueous medium | |
| JP2001514966A (en) | Support having multilayer coating and method for producing the same | |
| JP4111295B2 (en) | How to apply powder paint | |
| JP5300044B2 (en) | Coating film forming composition and coating film forming method | |
| JP4111287B2 (en) | Painting method | |
| CN115667422B (en) | One-component powder coating composition and substrate coated with the powder coating composition | |
| CN115698193B (en) | One-component powder coating composition and substrate coated with the powder coating composition | |
| JP2009215372A (en) | Matte powdered coating material composition and method for forming coating film | |
| JP2000176373A (en) | Tap water pipe with inner surface coated and method | |
| JP2009215371A (en) | Matte powdered coating material composition and method for forming coating film | |
| JP4232883B2 (en) | Manufacturing method of painted inorganic building materials | |
| JP2003211083A (en) | Deposition method for double-layered coating film by powder coating material | |
| JP2003286443A (en) | Coating composition comprising water-dispersed thermosetting mat powder | |
| JP4139173B2 (en) | Method for producing glitter powder coating | |
| JP4088065B2 (en) | Method for producing glitter powder coating | |
| JP4104358B2 (en) | Surface treatment method of glitter pigment for metallic powder coating | |
| JP2004099871A (en) | Color toning method of water-dispersed powder coating | |
| JP2003286441A (en) | Coating composition comprising water-dispersed thermosetting mat powder | |
| JP2002332456A (en) | Water-dispersed powder coating, method for producing the same and method for producing coated inorganic building material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A625 | Written request for application examination (by other person) |
Free format text: JAPANESE INTERMEDIATE CODE: A625 Effective date: 20050204 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20070712 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20070725 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070925 |
|
| 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: 20080402 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20080402 |
|
| 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: 20110418 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120418 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130418 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130418 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140418 Year of fee payment: 6 |
|
| LAPS | Cancellation because of no payment of annual fees |