JPS6012917B2 - Paint film formation method - Google Patents

Description

【発明の詳細な説明】 本発明は新規な塗膜形成方法に関する。[Detailed description of the invention] The present invention relates to a novel coating film forming method.

更に詳しくは複雑な形状の被塗物に実質上一層からなる
を施す方法に関する。More specifically, the present invention relates to a method of applying a coating consisting essentially of one layer to a workpiece having a complex shape.

近年、塗料及び塗装の省資源、無公害化が進められ、こ
れに適するものとして粉体塗料の使用が増加している。In recent years, resource-saving and pollution-free paints and coatings have been promoted, and the use of powder coatings has been increasing as suitable for this purpose.

上記粉体塗料を被塗物に塗装する方法として流動床浸漬
法、吹付法及び静電塗装法等があるが、薄く均一な膜厚
で塗装出来ること及び大型の被塗物にも塗装出来ること
等の点で静電塗装法が最も優れている。しかしながら静
電塗装法は被塗物の凹面部には逆に静電的な作用により
粉体塗料が到達し難くなり、粉体塗料が被覆されない場
合がある。この問題を解決する方法として、予め被塗物
に前補正（又は前補修）を施しておく方法が行われてい
る。Methods for applying the above-mentioned powder coatings to objects to be coated include fluidized bed dipping, spraying, and electrostatic coating, but they must be able to coat with a thin and uniform film thickness, and can also be applied to large objects. The electrostatic coating method is the most superior in these respects. However, in the electrostatic coating method, concave surfaces of the object to be coated are difficult to reach with the powder coating due to electrostatic action, and the powder coating may not be coated. As a method to solve this problem, a method is used in which the object to be coated is subjected to pre-correction (or pre-repair) in advance.

例えば‘１｝流動床浸療法により塗装する場合に被塗物
の角の部分の膜厚が薄くなるのを防ぐために、予め該角
の部分に吹付法により粉体塗料を塗布し前補正する方法
、あるいは‘２｝有機溶剤希釈型塗料で前補正塗装し、
粉体塗膜と同時に加熱成膜する方法などが知られている
。しかるに前者｛１）の方法は被塗物の凹面部の前補正
に適用することは出来ない。For example, '1} When painting by fluidized bed immersion method, in order to prevent the film thickness from becoming thinner at the corners of the object to be coated, powder coating is applied in advance to the corner parts by spraying method and pre-correction is performed. , or '2} Pre-correction painting with organic solvent diluted paint,
A method of forming a film by heating at the same time as powder coating is known. However, the former method {1) cannot be applied to pre-correction of concave portions of objects to be coated.

即ち、粉体塗料を凹面部へ吹付塗装すれば該凹面部より
の空気の反発力により粉体塗料が充分に凹面部に付着し
ないのである。一方、後者の場合ノズルの噴射角度を小
さくすれば凹面部に塗料を塗布することが可能である。
しかし補正部の周緑部で該溶剤希釈型塗料の上に粉体塗
料が塗り重なる部分では、溶剤が粉体塗料を膨潤するた
め塗膜にダレ、リフティング、はだあれ等を起すという
問題があった。また有機溶剤が漣散するため塗装ライン
に排気処理装置もしくは溶剤回収装置を設置しなければ
ならず塗装コストが必然的に高くなるという問題があっ
た。本発明者等はこれ等の欠点を改良すべくェマルジョ
ン塗料及び水溶性樹脂塗料等の水系塗料で前補正するこ
とについて検討を加えたが、これ等の塗料は乾燥時に表
面乾燥が著しく、そのうえ溶媒として用いる水が通常の
有機溶媒に比較し高沸点、高比熱であるため、下塗り塗
腹中に水が内包され、加熱により成膜する際に塗膜にワ
キ、フクレ、ピンホール等を起し、特に加熱温度を高く
し乾燥工程を短縮すれば塗面のアいまさらに著しくなり
、いずれの場合も前補正用塗料として不適当であること
を知見した。That is, when a powder coating is spray-painted onto a concave surface, the powder coating does not sufficiently adhere to the concave surface due to the repulsive force of the air from the concave surface. On the other hand, in the latter case, it is possible to apply the paint to the concave surface by reducing the spray angle of the nozzle.
However, in the green area around the correction area where the powder coating is coated on top of the solvent-diluted coating, the solvent swells the powder coating, causing problems such as sagging, lifting, and peeling of the coating. there were. Furthermore, since the organic solvent is scattered, an exhaust treatment device or a solvent recovery device must be installed in the coating line, which inevitably increases the coating cost. In order to improve these shortcomings, the present inventors have considered pre-correction with water-based paints such as emulsion paints and water-soluble resin paints, but these paints cause significant surface drying when drying, and in addition, the solvent Since the water used as an organic solvent has a higher boiling point and higher specific heat than ordinary organic solvents, water is encapsulated in the undercoat and causes wrinkles, blisters, pinholes, etc. in the coating when it is formed by heating. In particular, it has been found that if the heating temperature is increased and the drying process is shortened, the aggregation of the coated surface becomes even more noticeable, and in either case, it is unsuitable as a pre-correction paint.

本発明はこのような粉体塗料の塗装上の問題を解決し通
常の粉体静電塗装により均質な被覆を形成出来ない凹面
部を有する被塗膜に、塗り重なることの避けられない部
分を除き実質上一層からなる均質な被覆を施す方法に関
する。The present invention solves these problems in applying powder coatings, and eliminates areas where overlapping coatings are inevitable on coated films that have concave areas where it is not possible to form a homogeneous coating using ordinary powder electrostatic coating. The present invention relates to a method for applying a homogeneous coating consisting of substantially one layer except for the following.

即ち、本発明は通常の粉体静電塗装により均質な被覆を
形成出来ない凹面部を有する基体上に、粒子径０．５〜
８０〃程度の樹脂粒子を水と主体とする溶媒中に分散し
てなるスラリー状塗料を該基体の該面部及びその周縁部
に均質にスプレー塗布し、続いて該塗腰を成膜せずに粉
体塗料を静電塗装し、各塗膜の成膜温度のうち最も高い
成膜温度以上で加熱乾燥し、上記において該スラリー状
塗料と粉体塗料の色数差（△Ｅ）が５以下の塗料の組合
せを使用する塗膜形成方法に関する。That is, the present invention applies particles with a particle size of 0.5 to
A slurry paint consisting of resin particles of about 80 mm dispersed in a solvent mainly composed of water is uniformly sprayed onto the surface and its periphery of the substrate, and then the coating thickness is not formed into a film. The powder coating is electrostatically coated, heated and dried at a temperature higher than the highest of the coating temperatures of each coating, and in the above, the difference in color number (△E) between the slurry coating and the powder coating is 5 or less. The present invention relates to a coating film forming method using a combination of paints.

本発明に於て、基体は各種の素材からなるものを包含す
る。In the present invention, the substrate includes those made of various materials.

就中、従来公知の粉体静電塗装により均質な被覆を達成
できなかったような形体の基体に適用する。本発明で使
用するスラリー状塗料とは、粒子径０．５〜８０仏程度
の樹脂粒子を、固形分で約２０〜６０重量％含有する水
分数体を主体とする塗料である。In particular, it is applied to substrates of such a shape that it has not been possible to achieve a homogeneous coating by conventional powder electrostatic coating methods. The slurry paint used in the present invention is a paint mainly composed of water and resin particles having a particle size of about 0.5 to 80 mm and containing about 20 to 60% by weight in solid content.

それは、 （ｉ｝ 塗料中に多量の有機溶剤、揮発性塩基及び界面
活性剤等を含まない。It does not contain large amounts of organic solvents, volatile bases, surfactants, etc. in the paint.

そのため無公害、省資源型の塗料であり、かつ耐水性、
耐薬品性等のすぐれた塗膜が形成される。（ｉｉ） 固
形分が約４０〜６の重量％という高い濃度で塗布できる
ため、一度に厚膜に塗装できる。Therefore, it is a pollution-free, resource-saving paint, and is also water resistant.
A coating film with excellent chemical resistance is formed. (ii) Since it can be applied at a high concentration of about 40 to 6% solids by weight, a thick film can be applied at one time.

（ｉｉｉ） 従釆の溶液型塗料の塗装装置がそのまま使
用可能である。(iii) The secondary solution-type paint coating equipment can be used as is.

というような種々の長所を有するものである。It has various advantages such as:

このような長所からスラリー状塗料は、今後実用化され
、かつその需要が大きく伸びると予想されている。一方
、スラリー状塗料は樹脂粒子の水分散体を主体とするも
のであるため、貯蔵中に沈澱凝集し易く、また塗装後加
熱成榛時に、クラックを起し易いという欠点を有してい
る。Because of these advantages, slurry paints are expected to be put into practical use in the future, and the demand for them is expected to increase significantly. On the other hand, slurry paints are mainly composed of an aqueous dispersion of resin particles, and therefore have the drawbacks of being prone to sedimentation and agglomeration during storage, and of being prone to cracking during heating after coating.

そこでこのような欠点または問題点を除去あるいは改善
するために、水溶性樹脂、ェマルジョン樹脂を添加する
ことが提案されている。Therefore, in order to eliminate or improve such drawbacks or problems, it has been proposed to add water-soluble resins or emulsion resins.

この点に関し本発明で使用するスラリー状塗料は、前記
ェマルジョン及び水溶性樹脂塗料の問題点を除去するた
めに、固形分で樹脂粒子１０の重量部に対して上記水落
性樹脂及び／又はェマルジョン樹脂が３の重量部以下の
ものを使用する。In this regard, in order to eliminate the problems of the emulsion and water-soluble resin paints, the slurry paint used in the present invention contains the water-dropping resin and/or emulsion resin based on the solid content of 10 parts by weight of the resin particles. Use 3 parts by weight or less.

該樹脂の量は好ましくは１の重量部以下、特に好ましく
は５重量部以下である。更に本発明で使用するスラリー
状塗料は、適当量の流動性付与剤、界面活性剤、被塗面
湿潤剤、増粘剤、つや消剤、一次防錆剤等の添加剤を含
んでもよい。The amount of resin is preferably less than 1 part by weight, particularly preferably less than 5 parts by weight. Furthermore, the slurry-like paint used in the present invention may contain appropriate amounts of additives such as a fluidity imparting agent, a surfactant, a coating surface wetting agent, a thickener, a matting agent, and a primary rust preventive agent.

更に必要により、通常塗料に用いられる無機系及び有機
系の着色及び体質顔料を適宜含有していてもよい。Furthermore, if necessary, inorganic and organic coloring and extender pigments commonly used in paints may be appropriately contained.

このような顔料分は、上記樹脂粒子中及び水媒体中のい
ずれかもし〈は両方に分散練合される。前記スラリー状
塗料中の樹脂粒子の粒子径は、塗膜の平滑性、塗装作業
性及び塗料の貯蔵安定性より８０仏以下であり、また塗
膜の表面乾燥及びダレ易さを防止するために、０．５仏
以上であることが要求される。Such a pigment component is dispersed and kneaded in either the resin particles or the aqueous medium or both. The particle size of the resin particles in the slurry paint is 80 mm or less in view of the smoothness of the paint film, painting workability, and storage stability of the paint, and in order to prevent the surface drying and sagging of the paint film. , 0.5 French or more is required.

特に４〜３０仏の粒子径のものが好ましい。該樹脂粒子
は粒子相互の凝集ゆ着を防止するために、軟化点５℃以
上であり、また８０〜２４び０の加熱温度で熔融成膜化
するために、軟化点１２０℃以下であることが要求され
る。Particularly preferred are those with a particle size of 4 to 30 degrees Fahrenheit. The resin particles should have a softening point of 5°C or higher to prevent mutual agglomeration and sticking, and a softening point of 120°C or lower to form a melt film at a heating temperature of 80 to 24°C. is required.

前記に於て、特に軟化点が５０ｑｏ以上のものは加熱時
に樹脂粒子が溶融平滑化するまでに充分な通気性を保ち
、塗膜中の分散媒を良好に蒸発せしめるため本発明には
好適である。In the above, those having a softening point of 50 qo or more are particularly suitable for the present invention because they maintain sufficient air permeability until the resin particles are melted and smoothed during heating, and the dispersion medium in the coating film can be evaporated well. be.

本発明に於て使用する樹脂としては、ェポキシ樹脂、ァ
ミン変性樹脂、フェノール樹脂、尿素樹脂、飽和ポリエ
ステル樹脂、ポリェーテル樹脂、不飽和ポリエステル樹
脂、ィソシアネートブロツク体、メラミン樹脂、アクリ
ル樹脂、アルキド樹脂等及びそれらの誘導体、ならびに
混合物等が挙げられる。The resins used in the present invention include epoxy resins, amine-modified resins, phenolic resins, urea resins, saturated polyester resins, polyether resins, unsaturated polyester resins, isocyanate blocks, melamine resins, acrylic resins, and alkyd resins. etc., their derivatives, and mixtures.

また前述したスラリー状塗料に混合し得る水落性樹脂及
びェマルジョン樹脂の構成樹脂としては、ァルキド樹脂
、酢酸ビニル樹脂、エチレン−酢酸ビニル共重合体、酢
酸ビニルーアクリル共重合体、メラミン樹脂、アクリル
樹脂、ポリエステル樹脂、ポリェーテル樹脂、尿素樹脂
、スチレンーブタジェン共重合体、ポリビニルブチラー
ル樹脂、ェポキシ樹脂、ポリブタジェン樹脂、フェノー
ル樹脂及びこれ等の誘導体等が使用される。In addition, constituent resins of the water-drop resin and emulsion resin that can be mixed with the slurry paint mentioned above include alkyd resin, vinyl acetate resin, ethylene-vinyl acetate copolymer, vinyl acetate-acrylic copolymer, melamine resin, and acrylic resin. , polyester resins, polyether resins, urea resins, styrene-butadiene copolymers, polyvinyl butyral resins, epoxy resins, polybutadiene resins, phenolic resins, and derivatives thereof.

本発明においてスラリー状塗料の塗布は（ェアスプレー
、ェアレススプレー、静電スプレー塗装を含む）による
。本発明に於ては次いでこのスラリー状塗料の塗膜を加
熱成膜することなく、基体の全面にさらに粉体塗料を静
電塗装する。In the present invention, the slurry paint is applied by (including air spray, airless spray, and electrostatic spray coating). In the present invention, a powder coating material is then electrostatically coated on the entire surface of the substrate without heating and forming a coating film of this slurry coating material.

この粉体塗料の塗布はスラリー状塗料を塗布後直ちに行
っても、また適宜セッティングもしくは子熱した後であ
ってもよい。The powder coating may be applied immediately after the slurry coating is applied, or after appropriate setting or heating.

かくしてスラリー状塗料塗膜中の分散媒は樹脂粒子間隔
を通して自由に移動出来、前記周綾部で粉体塗料が塗り
重ね施されてもスラリー状塗料中の分散煤が毛管現象に
より粉体塗料塗膜中に拡散し、その結果引き緒つた塗膜
を形成する。In this way, the dispersion medium in the slurry paint film can move freely through the gaps between the resin particles, and even if the powder paint is applied over and over again at the periphery, the dispersed soot in the slurry paint will disintegrate into the powder paint film due to capillary action. as a result of which a sticky coating is formed.

このように、スラリー状塗料を塗布後直ちに粉体塗料を
塗布しても塗膜のズＩＪ落ちやタレ等の発生がなく平滑
な塗膜が形成出来るので、本発明に於ては塗装ラインの
簡略化及び工程の短縮をはかることができる。In this way, even if the powder coating is applied immediately after the slurry coating is applied, a smooth coating film can be formed without the occurrence of droplets or sagging of the coating film, so in the present invention, it is possible to form a smooth coating film on the coating line. Simplification and process shortening can be achieved.

本発明で使用する前記粉体塗料としては、公知のものが
そのま）使用出来る。As the powder coating used in the present invention, publicly known powder coatings can be used as they are.

該粉体樹脂の粒子蓬は塗膜の平滑性、及び塗装作業性よ
り２００仏以下、また加熱乾燥時にスラリー塗膜中の媒
体が蒸発可能な通気性を形成すること及び塗装作業性の
観点より１ム以上であることが望ましい。特に５〜８０
〃の粒子径のものが好適である。更に該粉体樹脂は粒子
相互の凝集ゆ着を防止するために、軟化点５０午○以上
であり、また８０〜２４０００の加熱温度で溶融成膜化
するために、軟化点１２０ｏｏ以下であることが好まし
いｏ前記において、特に軟化点が７０ｏｏ以上のものは
加熱時に粉体樹脂粒子が溶融平滑化するまでに充分な通
気性を保ち、スラリー状塗料塗膜中の媒体を良好に蒸発
させるため本発明には好適である。The particle size of the powder resin should be less than 200 French from the viewpoint of smoothness of the coating film and painting workability, and from the viewpoint of forming air permeability that allows the medium in the slurry coating film to evaporate during heating drying and from the viewpoint of painting workability. It is desirable that it is 1 mu or more. Especially 5-80
A particle size of 〃 is suitable. Furthermore, the powder resin should have a softening point of 50°C or higher in order to prevent particles from agglomerating together, and should have a softening point of 120°C or lower in order to melt and form a film at a heating temperature of 80 to 24,000°C. o In the above, it is preferable that the softening point is 70 oo or higher because it maintains sufficient air permeability until the powder resin particles are melted and smoothed during heating and allows the medium in the slurry paint film to evaporate well. Suitable for invention.

具体的には粉体樹脂としては、前記スラリー樹脂と同じ
ものが使用出釆る。また、粉体塗料の塗装は通常の粉体
塗料用静電塗装機を用いる。Specifically, the same powder resin as the slurry resin can be used. Further, for applying the powder coating, an ordinary electrostatic coating machine for powder coating is used.

本発明では必要により前記粉体塗料を塗布後、加熱乾燥
前に更にスラリ−状塗料を１〜数回塗布する等、繰り返
し数層を重ね塗りすることも出来る。In the present invention, if necessary, after applying the powder coating, a slurry coating may be further applied one to several times before heating and drying, and several layers may be repeatedly applied.

上記スラリー状塗料と粉体塗料とは、各々の塗膜を色数
差（△Ｅ）が５以下になるように組合せて使用する。The slurry paint and the powder paint are used in combination so that the difference in color number (ΔE) of each film is 5 or less.

上記△Ｅを５より大きくすれば両塗膜の境界で色の違い
が目立ち、均質な塗膜が形成し得なくなる。If the above ΔE is made larger than 5, the difference in color becomes noticeable at the boundary between the two coating films, making it impossible to form a homogeneous coating film.

特に△Ｅが３以下の組合せにすることが均質な色の被覆
を形成する点で好適である。In particular, a combination in which ΔE is 3 or less is preferable in terms of forming a uniformly colored coating.

以上の条件下で得られた塗膜は、塗装後直ちに又は必要
によりセッティング又は予熱により塗膜を予備乾燥した
後に、該塗膜の成膜温度以上で加熱乾燥する。The coating film obtained under the above conditions is heated and dried at a temperature equal to or higher than the film forming temperature of the coating film immediately after coating or after preliminary drying of the coating film by setting or preheating if necessary.

ここで塗膜の成膜温度とは各塗膜の成膜温度のうち最も
高い温度をいう。The film-forming temperature of a coating film herein refers to the highest temperature among the film-forming temperatures of each coating film.

上記本発明の方法により粉体塗料の静電塗装のみでは塗
り残しが生じ均質な被覆を形成出来ない凹面部を有する
基体に対し、均質な塗装を施すことが出釆る。By the above method of the present invention, it is possible to apply a uniform coating to a substrate having a concave surface where electrostatic coating of a powder coating alone causes uncoated areas and cannot form a uniform coating.

以下実施例により本発明を説明する。The present invention will be explained below with reference to Examples.

尚、実施例中の部及び％はすべて重量部及び重量％であ
る。All parts and percentages in the examples are by weight.

先ず次の通りの塗料を調製した。First, the following paints were prepared.

〔スラリー状塗料Ａの調製〕[Preparation of slurry paint A]

ェポキシ当量４５０〜５２５軟化温度６４〜７６ｑｏの
ェポキシ樹脂〔商品名ェピコート１００１シェル化学■
製〕８３部、２−フェニルィミダゾール１部、テトラハ
イドロフタリツクアンハィドラィド１３部、チタン白２
碇郡、フタロシアニンフル−２部を均一に溶融練合した
後、機械分砕して１２０メッシュ以下の樹脂粒子を得た
。Epoxy resin with an epoxy equivalent of 450 to 525 and a softening temperature of 64 to 76 qo [Product name: Epicoat 1001 Shell Chemical ■
] 83 parts, 2-phenylimidazole 1 part, tetrahydrophthalic anhydride 13 parts, titanium white 2
After uniformly melting and kneading 2 parts of phthalocyanine powder, the mixture was mechanically crushed to obtain resin particles of 120 mesh or less.

ついでポリアクリル酸系の増粘剤０．１部をトリェチル
アミン０．２部、水５峠部‘こ中和溶解したｐＨ７、粘
度６００比ｐｓの水溶液に前記ェポキシ樹脂粉末５戊部
を加え均一に分散しスラリー状塗料Ａを調製した。〔粉
体塗料Ｂの調製〕 上記スラリ−状塗料Ａに用いたェポキシ樹脂粒子をさら
に機械粉砕後分級して１８０メッシュ節通過の粉体塗料
Ｂを得た。Next, 5 parts of the epoxy resin powder was added to an aqueous solution having a pH of 7 and a viscosity of 600 ps, in which 0.1 part of a polyacrylic acid-based thickener was neutralized and dissolved in 5 parts of water and 0.2 parts of triethylamine. A slurry paint A was prepared by dispersing. [Preparation of Powder Paint B] The epoxy resin particles used in the slurry paint A were further mechanically pulverized and classified to obtain a powder paint B that passed through a 180 mesh node.

〔溶剤型塗料Ｃの調製〕[Preparation of solvent-based paint C]

上記スラリー状塗料Ａのェポキシ樹脂粒子を構成する各
成分５碇部とさらにエチレングリコ一ルモノェチルェー
テル５碇郡を用い、先ず可溶成分の均質な溶剤溶液を得
た後に顔料を加えボールミルで均一に練合分散して溶剤
型塗料Ｃを得た。Using 5 parts of each component constituting the epoxy resin particles of the slurry paint A and 5 parts of ethylene glycoyl monoethyl ether, first a homogeneous solvent solution of the soluble components was obtained, and then the pigment was added. The mixture was uniformly kneaded and dispersed using a ball mill to obtain a solvent-based paint C.

〔水落性塗料Ｄの調製〕[Preparation of water-removable paint D]

窒素気流中にてトール油脂肋酸４５６部、ィソフタル酸
２６４部、無水トリメット酸８７部、トリメチロ−ルプ
ロパン２７７部とキシロール４碇部を２４０ｑｏで６時
間還流縮合せしめ、脱水量８４部、樹脂の酸価５８．５
になった時キシロ−ル４０部を蒸留除去した。In a nitrogen stream, 456 parts of tall fat, 264 parts of isophthalic acid, 87 parts of trimethic anhydride, 277 parts of trimethylolpropane, and 4 parts of xylol were refluxed and condensed at 240 qo for 6 hours, resulting in a dehydrated amount of 84 parts and an acid content of the resin. Value 58.5
40 parts of xylol were removed by distillation.

その後温度を１８０ｏ０に下げトリメチルアミン９５部
及びエチレングリコ一ルモノェチルェーテル２４８部を
加え９０℃に冷却し水２７碇部加えて十分に縄梓混合し
た。この樹脂水溶液１０碇織こチタン白１２．８部、フ
タロシアニンブルー１．２８部及び表面調整剤０．２部
を加えボールミルで均一に練合分散して不揮発分６６．
６％、ｐＨ７．８の水溶性塗料を得た。〔ェマルジョン
塗料Ｅの調製〕不揮発分５０％、粘度３５０比ｐｓ、ｐ
Ｈ２．０、最低成膜温度５０午○のカルボキシル基含有
樹脂ヱマルジョン〔商品名ョドゾール３２ＡＩＯ＆鐘淵
紡績■製〕１２８部をジメチルェタノールアミン１．５
部で中和後、水溶Ｉ性アミノプラスト樹脂〔商品名スミ
テックスＭ−４０Ｗ、住友化学工業■製〕２の都、水２
碇部、チタン白１６．６部、プタロシアニンフルー１．
６６部及び成膜助剤８．７部を加えポールミルで均一に
分散練合し、ｐＨ８．５のェマルジョン塗料Ｅを作成し
た。Thereafter, the temperature was lowered to 180°C, 95 parts of trimethylamine and 248 parts of ethylene glycomonoethyl ether were added, the mixture was cooled to 90°C, 27 parts of water was added, and the mixture was thoroughly mixed. 10 parts of this aqueous resin solution, 12.8 parts of titanium white, 1.28 parts of phthalocyanine blue, and 0.2 parts of a surface conditioner were added and uniformly kneaded and dispersed in a ball mill to obtain a non-volatile content of 66.
A water-soluble paint of 6% and pH 7.8 was obtained. [Preparation of emulsion paint E] Non-volatile content 50%, viscosity 350 ps, p
128 parts of a carboxyl group-containing resin emulsion (trade name: Yodozol 32AIO & manufactured by Kanefuchi Boseki) with a minimum film-forming temperature of 50 pm and H2.0 were mixed with 1.5 parts of dimethylethanolamine.
After neutralization at 30°C, water-soluble I-type aminoplast resin [trade name Sumitex M-40W, manufactured by Sumitomo Chemical Co., Ltd.] 2 no Miyako, Water 2
Ikaribe, Titanium White 16.6 parts, Pthalocyanine Flu 1.
66 parts and 8.7 parts of a film-forming aid were added and uniformly dispersed and kneaded using a Pall mill to prepare emulsion paint E having a pH of 8.5.

〔スラリー状塗料Ｆ及びＧの調整〕前記ス′ラリー状塗
料ＡＩＯ碇部もこ対して、前記水溶性塗料Ｄとそれぞれ
２８．５部及び３部、また水をそれぞれ９．５部及び１
．０部加え、均一に櫨杵混合してスラリー状塗料Ｆ及び
Ｇを得た。[Adjustment of slurry paints F and G] Add 28.5 parts and 3 parts of the water-soluble paint D to the anchor part of the slurry paint AIO, respectively, and 9.5 parts and 1 part of water, respectively.
．． 0 parts were added and mixed uniformly with a pestle to obtain slurry paints F and G.

スラリー状塗料Ｆ及びＧは共に固形分５０％で、また塗
料中の樹脂粒子と水溶性樹脂の重量比は「 夫々１００
／３１及び１００／３．３である。実施例 基体として長さ３０の、中２０伽の磨鋼板を長さ方向と
平行に中央で９０ｏに折り曲げた鋼材を使用し、先ず前
記液状塗料Ａ及びＣ〜Ｇを各々上記基村の凹面部に折り
曲げ線を欠む約１０肌の中にエアースプレー塗布した。Slurry paints F and G both have a solid content of 50%, and the weight ratio of resin particles to water-soluble resin in the paints is 100%.
/31 and 100/3.3. Example A steel material obtained by bending a polished steel plate of length 30 and 20 degrees in the center parallel to the length direction at 90 degrees was used as the base material. Air spray was applied to about 10 areas of the skin that lacked the fold line.

次に上記塗膜を１〜３分間セッティングした後に、粉体
塗料Ｂを静電塗装機（商品名ＲＥＴ、ランズバーク社製
）で、６０タ′〆の塗布量で塗装し、直ちに加熱乾燥し
た。この方法により液体塗料ＡないいまＣ〜Ｇと粉体塗
料Ｂとが約４肌の中で塗り重なった被覆鋼材が得られた
。表−１に各液状塗装の塗装条件及び上記塗り重なり塗
膜部の塗面状態を示す。Next, after setting the above coating film for 1 to 3 minutes, powder coating B was applied with an electrostatic coating machine (trade name: RET, manufactured by Landsberg Co., Ltd.) at a coating weight of 60 ta', and immediately dried by heating. By this method, a coated steel material was obtained in which liquid paints A to C to G and powder paint B were coated over each other in about four areas. Table 1 shows the coating conditions for each liquid coating and the coating surface condition of the overlapping coating film portion.

表の塗面状態の記載から、本発明の方法によるものが優
れていることが明瞭である。From the description of the coated surface condition on the table, it is clear that the method of the present invention is superior.

上記実施例及び比較例より明白な如く本発明者の方法に
よればピンホール、ワキ、フクレ等の無い２種類の塗膜
を１回の加熱乾燥により形成することが出釆工業塗装ラ
インにおいてＴｗｏ−Ｃｏａｔ−ｏ船−Ｂａｋｅ塗装や
静電粉体塗装の前補正に極めて有効に利用出来る。As is clear from the above Examples and Comparative Examples, according to the method of the present inventor, two types of coating films without pinholes, wrinkles, blisters, etc. can be formed by one heating drying process. -Coat-o ship- It can be used extremely effectively for pre-correction of bake painting and electrostatic powder coating.

表 − １Table-1

Claims (1)

【特許請求の範囲】 １ 通常の粉体静電塗装により均質な被覆を形成出来な
い凹面部を有する基体上に、粒子径０．５〜８０μ程度
の樹脂粒子を水を主体とする媒体中に分散してなるスラ
リー状塗料を該基体の該面部及びその周縁部にスプレー
塗布し、続いて該塗膜を成膜せずに前記スラリー状塗料
と色差数（ΔＥ）が５以下である粉体塗料を静電塗装し
、最後に各塗膜の成膜温度のうち最も高い成膜温度以上
で加熱乾燥することを特徴とする塗り重なることが避け
られない部分を除き、実質上一層からなる塗膜形成方法
。 ２ 該スラリー状塗料中の樹脂粒子の粒子径は、４〜３
０μであることを特徴とする特許請求の範囲第１項記載
の塗膜形成方法。 ３ 該スラリー状塗料中の樹脂粒子の軟化点は５０〜１
２０℃であることを特徴とする特許請求の範囲第１項又
は第２項記載の塗膜形成方法。 ４ 該スラリー状塗料は、使用樹脂粒子１００重量部（
固形分換算）に対して更に水溶性樹脂及び／又はエマル
ジヨン樹脂を３０重量部以下含むことを特徴とする特許
請求の範囲第１、第２又は第３項記載の塗膜形成方法。 ５ 該粉体塗料の樹脂粒子の粒子径は、５〜８０μであ
ることを特徴とする特許請求の範囲第１、第２、第３又
は第４項記載の塗膜形成方法。６ 該粉体塗料の樹脂粒
子の軟化点は７０〜１２０℃であることを特徴とする特
許請求の範囲第１、第２、第３、第４又は第５項記載の
塗膜形成方法。[Claims] 1. On a substrate having a concave surface on which a homogeneous coating cannot be formed by ordinary powder electrostatic coating, resin particles with a particle size of about 0.5 to 80 μm are placed in a medium mainly composed of water. Spraying a dispersed slurry-like paint onto the surface portion and its periphery of the substrate, followed by powder having a color difference number (ΔE) of 5 or less from the slurry-like paint without forming the coating film. A coating consisting of essentially one layer, except for areas where overlapping coatings are unavoidable, characterized by applying the paint electrostatically and finally heating and drying it at a temperature higher than the highest of the film-forming temperatures of each coating film. Film formation method. 2 The particle size of the resin particles in the slurry paint is 4 to 3
The method for forming a coating film according to claim 1, wherein the coating film has a particle diameter of 0μ. 3 The softening point of the resin particles in the slurry paint is 50 to 1
The coating film forming method according to claim 1 or 2, characterized in that the temperature is 20°C. 4 The slurry paint contains 100 parts by weight of resin particles used (
The coating film forming method according to claim 1, 2 or 3, further comprising 30 parts by weight or less of a water-soluble resin and/or emulsion resin (based on solid content). 5. The coating film forming method according to claim 1, 2, 3, or 4, wherein the particle size of the resin particles of the powder coating is 5 to 80 μm. 6. The coating film forming method according to claim 1, 2, 3, 4, or 5, wherein the resin particles of the powder coating have a softening point of 70 to 120°C.