JP2995711B2 - Method of coloring aluminum or aluminum alloy - Google Patents

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【産業上の利用分野】本発明は、アルミニウム又はアル
ミニウム合金（以下、アルミニウムと総称する）の着色
方法に関し、さらに詳しくは、アルミニウムの多孔質陽
極酸化皮膜の細孔中に電気泳動法によって有機顔料又は
カーボンブラックを析出・充填させ、着色する方法に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coloring aluminum or an aluminum alloy (hereinafter referred to as "aluminum"), and more particularly, to an organic pigment which is formed by electrophoresis in the pores of a porous anodic oxide film of aluminum. Alternatively, the present invention relates to a method of depositing and filling carbon black and coloring.

【０００２】[0002]

【従来の技術】従来、アルミニウム陽極酸化皮膜の着色
方法としては、各種金属塩を含有する浴中での交流電解
による電解着色法を中心に、各種染料の浴を用いての浸
漬着色法等、多くの方法が知られている。しかしなが
ら、電解着色法ではブロンズ色等の茶色系以外の着色は
容易でなく、色の種類が限定されるという難点があり、
一方、染料による染色では各種の色への着色は容易であ
るが、光等に対する耐久性が低いという難点がある。こ
のような問題を解決するための方策として、微細粒顔料
の水分散体中で電気泳動法により多孔質陽極酸化皮膜を
着色する方法が種々提案されており、本出願人も、アル
ミニウムの表面に通常の細孔径より大きい細孔を有する
多孔質陽極酸化皮膜を形成させた後、該皮膜の細孔中に
３〜１５０ｎｍの大きさに微細化した有機顔料又はカー
ボンブラックの水分散体中から電気泳動法によって有機
顔料又はカーボンブラックを泳動・析出させて充填し、
着色する方法を既に提案している（特開平５−９３２９
６号公報参照）。2. Description of the Related Art Conventionally, as a method of coloring an aluminum anodic oxide film, there have been mainly used an electrolytic coloring method by alternating current electrolysis in a bath containing various metal salts, and an immersion coloring method using a bath of various dyes. Many methods are known. However, in the electrolytic coloring method, coloring other than a brownish color such as a bronze color is not easy, and there is a disadvantage that the type of color is limited,
On the other hand, dyeing with a dye is easy to color various colors, but has a drawback that durability against light or the like is low. As a measure to solve such a problem, various methods of coloring a porous anodic oxide film by an electrophoresis method in an aqueous dispersion of a fine-grain pigment have been proposed. After a porous anodic oxide film having pores larger than a normal pore diameter is formed, an aqueous solution of an organic pigment or carbon black finely reduced to a size of 3 to 150 nm is formed in the pores of the film. Electrophoresis or deposition of organic pigment or carbon black by electrophoresis method and filling.
A method of coloring has already been proposed (JP-A-5-9329).
No. 6).

【０００３】[0003]

【発明が解決しようとする課題】上記特開平５−９３２
９６号公報に記載の着色方法によれば、顔料の選択に応
じて赤、黒、青等の種々の所望の色に着色でき、また、
例えば直流定電圧電解法を用い、所望の色の濃さに応じ
た電圧を印加することにより、これに応じた広い範囲で
色の濃淡をコントロールすることが可能である。しかし
ながら、皮膜の着色状態は顔料分散体の条件により、色
むらの発生が見られたり、顔料が皮膜表面に異常析出し
濃い着色皮膜が得られないという欠点がある。すなわ
ち、顔料分散体が必要以上の電気電導性を持つと、顔料
の泳動に無関係な電流が多く流れる。この電流により、
皮膜細孔内では水の電気分解などの陽極反応が激しく起
こり、着色皮膜の細孔内又は皮膜近傍のｐＨは低下す
る。この変化が激しいため、顔料の表面電位の低下、凝
集、析出が皮膜細孔内で不均一に起こり、または皮膜表
面に析出しやすくなるため、色むら、皮膜表面での顔料
の異常析出が見られる。また、皮膜の着色状態は、顔料
分散体の他の条件によっても色むらの発生が見られる。SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. Hei 5-9332.
According to the coloring method described in No. 96, depending on the selection of the pigment, red, black, can be colored to various desired colors such as blue,
For example, by applying a voltage corresponding to a desired color density using a DC constant voltage electrolysis method, it is possible to control the color density in a wide range according to the voltage. However, depending on the conditions of the pigment dispersion, the coloring state of the film has the disadvantage that color unevenness is observed, or the pigment is abnormally deposited on the film surface, and a dark colored film cannot be obtained. That is, if the pigment dispersion has an electric conductivity more than necessary, a large amount of current irrelevant to the migration of the pigment flows. With this current,
In the pores of the film, an anodic reaction such as electrolysis of water occurs violently, and the pH in or near the pores of the colored film decreases. Due to the drastic change, the surface potential of the pigment decreases, agglomerates, and precipitates occur nonuniformly in the pores of the film, or easily precipitates on the film surface. Can be Further, as for the coloring state of the film, the occurrence of color unevenness is observed depending on other conditions of the pigment dispersion.

【０００４】従って、本発明の基本的な目的は、微細顔
料をアルミニウムの多孔質陽極酸化皮膜に電気泳動法に
よって析出・充填させ着色する方法において、色むらの
発生や皮膜表面に顔料が凝集（ゲル化）し異常析出する
のを防止することにある。さらに本発明の目的は、多孔
質陽極酸化皮膜表面への顔料の異常析出や色むらの発生
もなく、所望の色相及び濃淡に広い範囲でコントロール
可能なアルミニウムの着色方法を提供することにある。
本発明の他の目的は、アルミニウムの多孔質陽極酸化皮
膜の細孔深くに顔料を析着・充填させ、建築外装材等に
要求される諸耐久性を満たすと共に、変・退色もなく、
堅牢で色鮮やかな所望の色相の着色酸化皮膜を作製でき
るアルミニウムの着色方法を提供することにある。Accordingly, a basic object of the present invention is to provide a method in which fine pigments are deposited and filled in a porous anodic oxide film of aluminum by electrophoresis to cause color unevenness and agglomeration of pigments on the surface of the film. Gelation) and abnormal precipitation. It is a further object of the present invention to provide a method for coloring aluminum which can be controlled over a wide range of desired hues and shades without causing abnormal precipitation of pigments and uneven coloration on the surface of the porous anodic oxide film.
Another object of the present invention is to deposit and fill a pigment deep into the pores of the porous anodic oxide film of aluminum, satisfying various durability required for building exterior materials, etc., without discoloration or fading.
It is an object of the present invention to provide a method of coloring aluminum capable of producing a colored oxide film having a desired color tone which is robust and colorful.

【０００５】[0005]

【課題を解決するための手段】前記目的を達成するた
め、本発明によれば、多孔質陽極酸化皮膜を形成したア
ルミニウム又はアルミニウム合金を、顔料濃度が１０〜
５０ｇ／ｌの範囲内にあり、かつ顔料濃度１０ｇ／ｌ当
り１０００μＳ／ｃｍ以下の比電導度に調整した有機顔
料又はカーボンブラックの顔料分散体の浴中で電気泳動
処理し、多孔質陽極酸化皮膜の細孔深部にまで有機顔料
又はカーボンブラックを析出させ着色することを特徴と
するアルミニウム又はアルミニウム合金の着色方法が提
供される。好適な態様によれば、上記顔料分散体として
は、粒子径３〜１５０ｎｍの有機顔料又はカーボンブラ
ックの顔料分散体が用いられ、また該顔料分散体の浴の
条件としては、顔料濃度は好ましくは１０〜４０ｇ／
ｌ、浴の温度は２５℃以下、好ましくは１５〜２５℃、
浴のｐＨは８．５〜１０、好ましくは８．５〜９．５が
望ましい。According to the present invention, aluminum or an aluminum alloy on which a porous anodic oxide film has been formed is prepared by adding a pigment having a pigment concentration of 10 to 10 to achieve the above object.
Electrophoretic treatment in a bath of an organic pigment or carbon black pigment dispersion in the range of 50 g / l and adjusted to a specific conductivity of 1000 μS / cm or less per 10 g / l pigment concentration, the method of coloring an aluminum or aluminum alloy, characterized in that coloring organic pigments or carbon black is out analysis is provided to the pores deep. According to a preferred embodiment, as the pigment dispersion, a pigment dispersion of an organic pigment or carbon black having a particle diameter of 3 to 150 nm is used, and as a condition of the bath of the pigment dispersion, the pigment concentration is preferably 10 to 40 g /
1, the temperature of the bath is 25 ° C. or less, preferably 15 to 25 ° C.,
The pH of the bath is desirably 8.5 to 10 , preferably 8.5 to 9.5.

【０００６】[0006]

【発明の作用及び態様】前記したように、微細顔料を電
気泳動法によって多孔質陽極酸化皮膜の細孔内に析出・
充填させる着色方法においては、顔料分散体の条件によ
り、皮膜の着色状態には色むらの発生や皮膜表面への顔
料の異常析出がみられる。すなわち、微細顔料の電気泳
動法による着色方法においては、電圧の印加により顔料
が多孔質陽極酸化皮膜の細孔内に泳動されるが、顔料分
散体が必要以上の電導性を持つと、電圧の印加によって
顔料の泳動に無関係な電流が多く流れる。この電気泳動
に関係のない電流により、皮膜細孔内では水の電気分解
などの陽極反応が必要以上に起こり、着色皮膜の細孔内
又は皮膜近傍のｐＨを急激に低下させるため、顔料が皮
膜細孔内に不均一に析出したり、皮膜表面に凝集（ゲル
化）、析出し易くなる。そこで、本発明では、顔料分散
体の顔料濃度を１０〜５０ｇ／ｌの範囲内に規定すると
共に、顔料の泳動に作用しない電流が殆ど流れないよう
に顔料分散体の浴の比電導度を顔料濃度１０ｇ／ｌ当り
１０００μＳ／ｃｍ以下に調整して電気泳動を行うもの
であり、それによって上記のような必要以上な陽極反応
や皮膜近傍でのｐＨの急激な低下が抑制され、顔料の凝
集を防止できる。従って、色むらや皮膜表面への顔料の
異常析出の発生もなく、広い電圧範囲で所望の濃淡の着
色皮膜に着色が可能となり、耐光性、耐候性、耐熱性等
の諸特性に優れ、顔料の離脱もなく、堅牢で色鮮やかな
アルミニウムの着色皮膜を得ることができる。As described above, the fine pigment is deposited in the pores of the porous anodic oxide film by electrophoresis.
In the coloring method for filling, depending on the conditions of the pigment dispersion, uneven coloring and abnormal precipitation of the pigment on the film surface are observed in the coloring state of the film. In other words, in the coloring method of the fine pigment by the electrophoresis method, the pigment is migrated into the pores of the porous anodic oxide film by applying a voltage, but if the pigment dispersion has an unnecessary conductivity, the voltage is reduced. Due to the application, a large amount of current irrelevant to the migration of the pigment flows. Due to this current not related to electrophoresis, an anodic reaction such as electrolysis of water occurs in the pores of the coating more than necessary, and the pH in the pores of the colored coating or near the coating decreases rapidly. Precipitation is unevenly deposited in the pores, or agglomerates (gels) on the surface of the coating, and is likely to precipitate. Therefore, in the present invention, the pigment dispersion
If the pigment concentration of the body is specified in the range of 10 to 50 g / l,
In both cases, the electrophoresis is performed by adjusting the specific conductivity of the bath of the pigment dispersion to 1000 μS / cm or less per 10 g / l pigment concentration so that almost no current that does not affect the migration of the pigment flows. As described above, unnecessary anodic reaction and rapid drop of pH in the vicinity of the film can be suppressed, and aggregation of the pigment can be prevented. Therefore, it is possible to color a colored film having a desired density over a wide voltage range without causing color unevenness or abnormal precipitation of the pigment on the film surface, and is excellent in various properties such as light resistance, weather resistance and heat resistance. , And a robust and colorful aluminum colored film can be obtained.

【０００７】本発明によるアルミニウムの着色方法にお
いて、基本的な着色条件は、顔料分散体の浴を顔料濃度
１０ｇ／ｌ当り１０００μＳ／ｃｍ以下の比電導度に調
整することである。顔料分散体の比電導度が１０００μ
Ｓ／ｃｍを越えると、前記したように顔料の泳動に関係
のない電流が流れ易くなり、陽極反応、具体的には、水
の電気分解などが起こり、色むらや顔料の表面析出が生
じ易くなるので好ましくない。顔料分散体は、有機顔料
又はカーボンブラックの顔料分散体を、分散剤として陰
イオン性の高分子活性剤、たとえばナフタリンスルホン
酸のホルマリン縮合物、ポリスチレンスルホン酸塩、ポ
リアクリル酸塩及びこれらの共重合体等を用いて作製す
る。この時、分散剤の量や各種添加剤の添加を調整し、
顔料分散体の比電導度があまり高くならないようにす
る。この顔料分散体は、通常、着色に供する時、希釈や
ｐＨ調整が行なわれるが、そのときの比電導度が前記の
ように分散体中の顔料濃度１０ｇ／ｌ当り１０００μＳ
／ｃｍ以下であるようにする。In the method for coloring aluminum according to the present invention, the basic coloring condition is to adjust the bath of the pigment dispersion to a specific conductivity of 1000 μS / cm or less per 10 g / l of pigment concentration. Specific conductivity of pigment dispersion is 1000μ
If it exceeds S / cm, an electric current irrelevant to the migration of the pigment tends to flow as described above, and an anodic reaction, specifically, electrolysis of water occurs, and color unevenness and surface precipitation of the pigment easily occur. Is not preferred. The pigment dispersion is prepared by dispersing an organic pigment or a carbon black pigment dispersion as an anionic polymer activator such as a formalin condensate of naphthalenesulfonic acid, a polystyrenesulfonic acid salt, a polyacrylic acid salt and a co-polymer thereof. It is produced using a polymer or the like. At this time, adjust the amount of dispersant and the addition of various additives,
The specific conductivity of the pigment dispersion should not be too high. This pigment dispersion is usually diluted or adjusted for pH when it is subjected to coloring. The specific conductivity at that time is, as described above, 1000 μS per 10 g / l of the pigment concentration in the dispersion.
/ Cm or less.

【０００８】また、顔料分散体は、顔料濃度が５０ｇ／
ｌ以下、好ましくは１０〜４０ｇ／ｌ、ｐＨが１０以
下、好ましくは８．５〜９．５の範囲が望ましい。この
ような範囲に調整された顔料分散体中で、アルミニウム
陽極酸化皮膜を陽極として、電気泳動法で着色すると、
色むらの発生もなく、また顔料の皮膜表面への異常析出
が高い泳動電圧でも起こらない為、広い電圧範囲で着色
が可能となり、また濃淡の制御された着色が可能とな
る。浴中の顔料濃度が５０ｇ／ｌを越えて高くなると、
顔料濃度が大きいために顔料が凝集し易くなり、皮膜表
面に析出し易くなり、逆に顔料濃度が１０ｇ／ｌ未満で
あると、顔料が少ないために色を濃くすることが難し
く、いずれの場合も十分な着色を行うことができなくな
るので好ましくない。また、浴のｐＨが８．５未満で
は、ｐＨが低く、顔料の表面電位が低くなり、凝集し易
く、皮膜表面に析出し易くなるので好ましくない。一
方、ｐＨが１０を越えるとアルカリ性が強く、細孔内に
析出した顔料が再び溶け、分散してしまうために、色が
薄くなってしまい色むらを発生するので好ましくない。Further, the pigment dispersion has a pigment concentration of 50 g /
1 or less, preferably 10 to 40 g / l, and the pH is 10 or less, preferably 8.5 to 9.5. In the pigment dispersion adjusted to such a range, when the aluminum anodic oxide film is used as an anode and colored by electrophoresis,
Since color unevenness does not occur, and abnormal deposition of the pigment on the film surface does not occur even at a high migration voltage, coloring can be performed in a wide voltage range, and coloring with controlled density can be performed. When the concentration of the pigment in the bath exceeds 50 g / l,
Since the pigment concentration is high, the pigment is easily aggregated and easily deposited on the film surface. Conversely, if the pigment concentration is less than 10 g / l, it is difficult to increase the color due to the small amount of the pigment. Is not preferable because sufficient coloring cannot be performed. On the other hand, if the pH of the bath is less than 8.5, the pH is low, the surface potential of the pigment is low, the pigment is easily aggregated, and the pigment is easily deposited on the film surface, which is not preferable. On the other hand, when the pH exceeds 10, the alkalinity is strong, and the pigment precipitated in the pores is again dissolved and dispersed, so that the color becomes thin and color unevenness occurs, which is not preferable.

【０００９】顔料分散体の作製には、顔料として高級有
機顔料やカーボンブラック、分散剤として陰イオン性の
高分子活性剤、たとえばナフタリンスルホン酸のホルマ
リン縮合物、ポリスチレンスルホン酸塩、ポリアクリル
酸塩及びこれらの共重合体を用いるが、この時、分散剤
の溶解や分散の安定剤として、アルカリや種々の添加剤
が加えられる。また着色に供する際にもｐＨの調整等で
薬品が加えられる。上記高級有機顔料は、近年進歩著し
い顔料で、着色性及び耐光性、耐候性、耐熱性、耐溶剤
性等の耐久性に優れた高品位の顔料である。この部類に
属するものには、縮合アゾ系顔料、フタロシアニン系顔
料、及びペリレン系、ペリノン系、キナクリドン系、チ
オインジゴ系、ジオキサジン系、イソインドリノン系、
イソインドリン系、キノフタロン系、金属錯体系等の縮
合多環顔料等がある。これらの顔料粒子は、一般に、１
０〜５００ｎｍの大きさの一次粒子が集合して凝集体を
形成しており、この凝集体を粒子径３〜１５０ｎｍの大
きさにまで分散させることが好ましい。これら顔料粒子
の微細化と分散化は、前記特開平５−９３２９６号公報
に記載のように、分散剤として陰イオン性の高分子活性
剤、例えば、ナフタレンスルホン酸のホルマリン縮合
物、ポリスチレンスルホン酸塩、ポリアクリル酸塩又は
これらの共重合体などを用いてサンドミルで分散させて
安定な水分散体を得る方法、サンドミルで分散させる前
に、前もって顔料にプラズマ処理などの表面処理を施し
ておき、より優れた水分散体を得る方法、あるいはさら
に、濃硫酸等に溶解する顔料については、一度濃硫酸等
に溶解し、それを水中に加えて、より微細な顔料粒子と
して析出させる方法などを単独で又は併用して採用する
ことが出来る。For preparing a pigment dispersion, a high-quality organic pigment or carbon black is used as a pigment, and an anionic polymer activator such as a formalin condensate of naphthalenesulfonic acid, a polystyrenesulfonic acid salt, or a polyacrylic acid salt is used as a dispersing agent. And a copolymer of these. At this time, an alkali or various additives are added as a stabilizer for dissolution or dispersion of the dispersant. In addition, chemicals are added for coloration by adjusting pH. The above-mentioned high-grade organic pigments are pigments that have been remarkably advanced in recent years, and are high-grade pigments having excellent durability such as coloring property, light resistance, weather resistance, heat resistance, and solvent resistance. Condensed azo pigments, phthalocyanine pigments, and perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone,
There are condensed polycyclic pigments such as isoindoline type, quinophthalone type and metal complex type. These pigment particles generally contain 1
Primary particles having a size of 0 to 500 nm are aggregated to form an aggregate, and the aggregate is preferably dispersed to a particle size of 3 to 150 nm. As described in JP-A-5-93296, these pigment particles are refined and dispersed as anionic polymer activators such as formalin condensate of naphthalenesulfonic acid and polystyrenesulfonic acid as described in JP-A-5-93296. A method of obtaining a stable aqueous dispersion by dispersing in a sand mill using a salt, a polyacrylate, or a copolymer thereof, etc., and subjecting the pigment to a surface treatment such as a plasma treatment in advance before dispersing in a sand mill. , A method of obtaining a better aqueous dispersion, or further, for a pigment that dissolves in concentrated sulfuric acid or the like, a method of once dissolving in concentrated sulfuric acid or the like, adding it to water, and precipitating it as finer pigment particles. It can be employed alone or in combination.

【００１０】上記のような有機顔料やカーボンブラック
を析出・充填させる多孔質陽極酸化皮膜としては、通常
の陽極酸化皮膜のポア径よりも大きな細孔、例えば５０
〜２００ｎｍ（５００〜２０００Å）程度の細孔を持つ
多孔質陽極酸化皮膜が望ましい。このような大きな細孔
を有する多孔質陽極酸化皮膜は、従来公知の種々の方法
により作成可能である。また、本出願人により既に特開
平５−９３２９６号公報で提案されている陽極酸化皮膜
の作成方法を好適に用いることができ、その方法は大別
して以下の二つの方法からなる。 （１）アルミニウムを鉱酸又は有機酸、例えば硫酸、リ
ン酸、シュウ酸、マロン酸、マレイン酸等の１種又は２
種以上の酸水溶液中で高電圧（例えば、ＤＣ１５０〜２
００Ｖ）で陽極酸化し、該アルミニウムの表面に通常の
ポア径より大きい細孔を持つ多孔質陽極酸化皮膜を形成
させる方法、及び（２）アルミニウムを鉱酸又は有機酸
の１種又は２種以上の酸水溶液中で陽極酸化し、該アル
ミニウムの表面に多孔質陽極酸化皮膜を形成させた後、
リン酸、硫酸、シュウ酸、スルファミン酸の１種又は２
種以上の酸水溶液に浸漬する処理又は浸漬と交流電解を
一定サイクルで繰り返す処理により、上記多孔質陽極酸
化皮膜の細孔の孔径拡大処理を行う方法。As the porous anodic oxide film for depositing and filling the organic pigment or carbon black as described above, pores larger than the pore diameter of a normal anodic oxide film, for example, 50 μm, are used.
A porous anodic oxide film having pores of about 200 to 200 nm (500 to 2000 °) is desirable. The porous anodic oxide film having such large pores can be prepared by various conventionally known methods. Further, the method of forming an anodic oxide film already proposed by the present applicant in Japanese Patent Application Laid-Open No. 5-93296 can be suitably used, and the method is roughly classified into the following two methods. (1) Aluminum is selected from mineral acids or organic acids such as sulfuric acid, phosphoric acid, oxalic acid, malonic acid, maleic acid or the like or 2
High voltage (e.g., DC 150-2
00V) to form a porous anodic oxide film having pores larger than the normal pore diameter on the surface of the aluminum, and (2) one or more of aluminum and a mineral acid or an organic acid After anodizing in an aqueous acid solution of, and forming a porous anodic oxide film on the surface of the aluminum,
One or two of phosphoric acid, sulfuric acid, oxalic acid, and sulfamic acid
A method of performing a treatment of immersing in an aqueous solution of at least two or more kinds of acids or a treatment of repeating immersion and alternating current electrolysis in a fixed cycle to perform a process of expanding the pore diameter of the pores of the porous anodic oxide film.

【００１１】着色処理においては、有機顔料やカーボン
ブラック等の水分散体中で上記陽極酸化皮膜を有するア
ルミニウム材を陽極とする電気泳動処理により、皮膜細
孔の深部にまで分散顔料が泳動析着され、鮮やかな着色
皮膜を得ることが出来る。電気泳動法としては、直流電
圧を低電圧より高電圧へ一定の昇圧速度で所望の色にな
るまで走査する直流電圧走査法、及び定電圧で所望の色
になるまでの時間を電解する直流定電圧法等により着色
処理を行うことができる。In the coloring treatment, the dispersed pigment is electrophoretically deposited to a deep portion of the pores of the film by electrophoresis in an aqueous dispersion of an organic pigment or carbon black using the aluminum material having the anodic oxide film as an anode. As a result, a bright colored film can be obtained. As the electrophoresis method, a DC voltage scanning method in which a DC voltage is scanned from a low voltage to a high voltage at a constant step-up speed until a desired color is obtained, and a DC voltage scanning method in which the time until the desired color is obtained at a constant voltage is performed. Coloring treatment can be performed by a voltage method or the like.

【００１２】電気泳動処理の条件は、陽極酸化の条件、
使用する顔料分散体及び所望の色濃度等に応じて適宜設
定することができる。例えば直流定電圧電解法で電気泳
動を行う場合、泳動電圧が高くなるにしたがい皮膜は濃
く着色され、泳動電圧が高くなり過ぎると顔料の皮膜表
面への異常析出が始まるが、顔料濃度が高くなると異常
析出する電圧が高くなるため、良好な状態で濃く着色さ
れた皮膜が得られる。一方、低い電圧では、顔料濃度が
高いと色むらの発生がみられる。そのため、例えば陽極
酸化電圧が１３０Ｖの場合、顔料濃度に応じて一般に１
１０〜１４０Ｖの範囲に設定することが望ましい。ま
た、泳動電圧が低い場合、浴温度が高くなるにしたがっ
て皮膜は濃く着色されるが、高電圧では大きな差はみら
れない。しかし、高電圧では、浴温度が高いと顔料の皮
膜表面への異常析出が起こり易くなる。従って、浴温度
は２５℃以下、好ましくは１５〜２５℃の範囲が望まし
い。このような電気泳動処理条件で着色処理を行うこと
により、色むらのない良好な着色が可能となり、また顔
料の皮膜表面への異常析出を起こさないで皮膜の濃淡が
広い電圧範囲で制御できる。なお、このようにして得ら
れたアルミニウムの着色皮膜には、さらに必要に応じて
封孔処理やクリヤー塗装を施すことが出来る。The conditions of the electrophoresis treatment include the conditions of anodization,
It can be set appropriately according to the pigment dispersion used, the desired color density, and the like. For example, when performing electrophoresis by DC constant voltage electrolysis, as the electrophoresis voltage increases, the film is colored deeply, and when the electrophoresis voltage is too high, abnormal precipitation on the pigment film surface starts, but when the pigment concentration increases, Since the voltage at which abnormal deposition occurs is increased, a densely colored film can be obtained in a good state. On the other hand, at a low voltage, color unevenness occurs when the pigment concentration is high. Therefore, for example, when the anodic oxidation voltage is 130 V, generally 1
It is desirable to set in the range of 10 to 140V. When the electrophoresis voltage is low, the film is colored deeper as the bath temperature increases, but no significant difference is observed at a high voltage. However, at a high voltage, when the bath temperature is high, abnormal deposition of the pigment on the surface of the film is likely to occur. Therefore, the bath temperature is desirably 25 ° C or lower, preferably in the range of 15 to 25 ° C. By performing the coloring treatment under such electrophoretic treatment conditions, good coloring without color unevenness can be achieved, and the density of the coating can be controlled in a wide voltage range without causing abnormal deposition of the pigment on the coating surface. The aluminum colored film thus obtained can be subjected to a sealing treatment or a clear coating, if necessary.

【００１３】[0013]

【実施例】以下、実施例を示して本発明についてさらに
具体的に説明するが、本発明が下記実施例に限定される
ものでないことはもとよりである。EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but it is needless to say that the present invention is not limited to the following examples.

【００１４】実施例１ 工業用純アルミ材Ａ１１００材を常法に従って前処理し
た後、２０℃の０．３％シュウ酸浴中で１５０Ｖ定電圧
電解を行った。次いで３０℃の５％リン酸溶液中に６０
分浸漬し、最後にホウ酸中性浴中で１１０Ｖで電解を行
い、皮膜厚１３μｍの陽極酸化皮膜を得た。その後、該
アルミ材を陽極として、ｐＨが９．０、比電導度が４０
００μＳ／ｃｍとした２５℃の濃度５０ｇ／ｌのカーボ
ンブラック水分散体中で、１３０Ｖで電気泳動処理を１
分間行い、鮮やかに着色された均一な黒色皮膜を得た。
なお、顔料の水分散体は、ポリアクリル酸ソーダを用い
て分散して調製し、その顔料粒径は６０ｎｍであった。Example 1 An industrial pure aluminum material A1100 was pretreated according to a conventional method, and then subjected to 150 V constant voltage electrolysis in a 0.3% oxalic acid bath at 20 ° C. Then 60% in a 5% phosphoric acid solution at 30 ° C.
And then electrolyzed at 110 V in a boric acid neutral bath to obtain an anodized film having a film thickness of 13 μm. Thereafter, using the aluminum material as an anode, the pH was 9.0 and the specific conductivity was 40.
The electrophoresis treatment was performed at 130 V in an aqueous carbon black dispersion having a concentration of 50 g / l at 25 ° C.
After a few minutes, a brightly colored uniform black film was obtained.
The aqueous dispersion of the pigment was prepared by dispersing using sodium polyacrylate, and the pigment particle size was 60 nm.

【００１５】比較例１ 実施例１と同じ条件で形成した陽極酸化皮膜を用い、同
じく実施例１で用いたカーボンブラック水分散体を蒸留
水で希釈して１０ｇ／ｌの濃度とし、これに水酸化ナト
リウム及び炭酸水素ナトリウムにてｐＨを９．０、比電
導度を４０００μＳ／ｃｍに調整した２５℃の顔料分散
体中で、１３０Ｖで１分間着色処理した。得られた着色
皮膜は色むらとなり、実施例１で得られた着色皮膜より
うすい着色となった。Comparative Example 1 Using the anodic oxide film formed under the same conditions as in Example 1, the aqueous carbon black dispersion also used in Example 1 was diluted with distilled water to a concentration of 10 g / l. Coloring treatment was performed at 130 V for 1 minute in a pigment dispersion at 25 ° C. adjusted to pH 9.0 and specific conductivity to 4000 μS / cm with sodium oxide and sodium hydrogen carbonate. The obtained colored film was uneven in color, and was slightly colored than the colored film obtained in Example 1.

【００１６】実施例２及び比較例２ 実施例１と同じ条件で形成した陽極酸化皮膜を、ポリア
クリル酸ソーダを分散剤に用いて、ｐＨを９．５、比電
導度が１２００μＳ／ｃｍとした２０ｇ／ｌの濃度の銅
フタロシアニンブルー水分散体中で、温度を表１に示す
１５〜３５℃の範囲の種々の温度に設定して電気泳動処
理し、着色した。泳動電圧は１２５Ｖとし、電気泳動処
理を１分間行った。なお、顔料の水分散体は、ポリアク
リル酸ソーダを用いて分散して調製し、その顔料粒径は
４０ｎｍであった。その結果を表１に示す。また、比較
例２として、同じ顔料濃度の銅フタロシアニンブルー水
分散体にマレイン酸ソーダ及び水酸化ナトリウムを加
え、ｐＨを９．５、比電導度を４０００μＳ／ｃｍとし
た分散体で泳動着色した結果も併せて示す。Example 2 and Comparative Example 2 An anodic oxide film formed under the same conditions as in Example 1 was adjusted to pH 9.5 and specific conductivity of 1200 μS / cm using sodium polyacrylate as a dispersant. In an aqueous copper phthalocyanine blue dispersion having a concentration of 20 g / l, the temperature was set to various temperatures in the range of 15 to 35 ° C. shown in Table 1, and electrophoresis treatment was performed to color. The migration voltage was 125 V, and the electrophoresis was performed for 1 minute. In addition, the aqueous dispersion of the pigment was prepared by dispersing using sodium polyacrylate, and the pigment particle size was 40 nm. Table 1 shows the results. Further, as Comparative Example 2, the result of adding sodium maleate and sodium hydroxide to an aqueous dispersion of copper phthalocyanine blue having the same pigment concentration, and performing electrophoretic coloring with a dispersion having a pH of 9.5 and a specific conductivity of 4000 μS / cm. Are also shown.

【００１７】[0017]

【表１】 表１に示す結果から明らかなように、比較例２のように
浴中の顔料濃度１０ｇ／ｌ当り４０００μＳ／ｃｍの高
い比電導度で電気泳動処理を行った場合、いずれの浴温
度においても色むらを生じ、特に高い浴温度においては
陽極酸化皮膜表面に顔料が異常析出したが、本発明に従
って浴中の顔料濃度１０ｇ／ｌ当り６００μＳ／ｃｍの
比電導度で電気泳動処理を行った場合、広い浴温度範囲
で、色むらや顔料の表面析出もなく、多孔質陽極酸化皮
膜の細孔内に顔料が析出・充填され、着色堅牢性に優れ
た色鮮やかな着色皮膜が得られた。但し、浴温度が３０
℃以上になると、色むらや顔料の表面析出が観察され
た。従って、浴温度は２５℃以下、特に１５〜２５℃の
範囲が好ましい。[Table 1] As is clear from the results shown in Table 1, when the electrophoretic treatment was performed at a high specific conductivity of 4000 μS / cm per 10 g / l of the pigment concentration in the bath as in Comparative Example 2, the color was not changed at any bath temperature. Irregularity was caused, and pigment was abnormally precipitated on the surface of the anodic oxide film particularly at a high bath temperature. However, when electrophoresis was performed at a specific conductivity of 600 μS / cm per 10 g / l of the pigment concentration in the bath according to the present invention, The pigment was deposited and filled in the pores of the porous anodic oxide film without color unevenness or surface precipitation of the pigment over a wide bath temperature range, and a brightly colored film having excellent color fastness was obtained. However, when the bath temperature is 30
At a temperature of not less than ° C., color unevenness and surface precipitation of pigment were observed. Therefore, the bath temperature is preferably 25 ° C. or less, particularly preferably in the range of 15 to 25 ° C.

【００１８】実施例３及び比較例３ 実施例１と同じ条件で形成した陽極酸化皮膜を用い、ポ
リスチレンスルホン酸ソーダを用いて分散した表２に示
す顔料濃度５〜１００ｇ／ｌの範囲の種々の濃度の銅フ
タロシアニングリーンの水分散体中で、泳動電圧１２５
Ｖで１分間電気泳動処理し、着色を行った。なお、この
ときのｐＨは９．０であり、顔料粒径は４０ｎｍであっ
た。このときの顔料分散体の比電導度と着色結果を表２
に示す。また、比較例３として、顔料濃度を５ｇ／ｌ一
定にし、比電導度を実施例３と同じように調整して着色
した場合の着色状態も併せて示す。Example 3 and Comparative Example 3 Using an anodized film formed under the same conditions as in Example 1 and dispersing with sodium polystyrene sulfonate, various pigments having a pigment concentration in the range of 5 to 100 g / l shown in Table 2 were used. Concentration of copper phthalocyanine green in an aqueous dispersion
V was electrophoresed for 1 minute to perform coloring. At this time, the pH was 9.0, and the pigment particle size was 40 nm. Table 2 shows the specific conductivity and the coloring result of the pigment dispersion at this time.
Shown in As Comparative Example 3, the coloring state when the pigment concentration was fixed at 5 g / l and the specific conductivity was adjusted and colored in the same manner as in Example 3 is also shown.

【００１９】[0019]

【表２】 表２に示す結果から、電気泳動浴中の顔料濃度が低すぎ
ると顔料の表面析出が観察され、逆に高すぎると色むら
が観察された。従って、顔料濃度は１０〜５０ｇ／ｌ、
特に１０〜４０ｇ／ｌが望ましい。[Table 2] From the results shown in Table 2, when the pigment concentration in the electrophoresis bath was too low, the surface precipitation of the pigment was observed, and when it was too high, color unevenness was observed. Therefore, the pigment concentration is 10 to 50 g / l,
Particularly, 10 to 40 g / l is desirable.

【００２０】実施例４及び比較例４ 実施例１と同じ条件で形成した陽極酸化皮膜を用い、ナ
フタレンスルホン酸ナトリウムホルマリン縮合物を分散
剤とした１０ｇ／ｌの濃度のキナクリドンレッドの分散
体中で、表３に示すようにｐＨを変え、１２０Ｖで１分
間電気泳動処理し、着色を行った。なお、浴温は２０
℃、顔料粒径は７０ｎｍであった。ｐＨ８．５〜１０．
０では均一な赤色着色皮膜が得られたが、ｐＨ１１で
は、淡赤色で色むらとなり、ｐＨ１２では着色しなかっ
た。また、比較例４として、ｐＨ１０以下の浴をｐＨ１
２の浴の比電導度（３０００μＳ／ｃｍ）と同じに四ホ
ウ酸ナトリウムを用いて調整し着色したところ、うすい
色むらの着色となった。結果を表３に示す。Example 4 and Comparative Example 4 An anodic oxide film formed under the same conditions as in Example 1 was used to prepare a dispersion of quinacridone red at a concentration of 10 g / l using sodium naphthalenesulfonate formalin condensate as a dispersant. The pH was changed as shown in Table 3 and electrophoresis was performed at 120 V for 1 minute to perform coloring. The bath temperature is 20
° C, the pigment particle size was 70 nm. pH 8.5-10.
At 0, a uniform red colored film was obtained, but at pH 11, the color became pale red and uneven, and at pH 12, it was not colored. Further, as Comparative Example 4, a bath having a pH of 10 or less
When adjusted and colored with sodium tetraborate in the same manner as the specific conductivity (3000 μS / cm) of the bath No. 2, the color became pale and uneven. Table 3 shows the results.

【００２１】[0021]

【表３】 [Table 3]

【００２２】[0022]

【発明の効果】以上のように、本発明のアルミニウムの
着色方法によれば、顔料分散体の顔料濃度を１０〜５０
ｇ／ｌの範囲内に規定すると共に、顔料の泳動に無関係
な電流が殆んど流れないように顔料分散体の浴の比電導
度を顔料濃度１０ｇ／ｌ当り１０００μＳ／ｃｍ以下に
調整して電気泳動を行うものであるため、前記したよう
な陽極反応の生起や皮膜近傍でのｐＨの急激な低下が抑
制され、顔料の異常な凝集を防止でき、従って、色むら
や皮膜表面への顔料の異常析出のない着色を行うことが
できる。また、広い電圧範囲で所望の濃淡の着色皮膜に
着色が可能となり、しかも顔料は皮膜細孔の深部にまで
析出・充填されているため、耐光性、耐候性、耐熱性等
の諸特性に優れ、顔料の離脱もなく、堅牢で耐久性に優
れた鮮やかな着色皮膜を得ることが出来る。また、顔料
を選択することにより、赤、黒、青等の種々の所望の色
に着色出来、アルミニウムの多色化のニーズにも十分に
応えることができる。As described above, according to the method for coloring aluminum of the present invention, the pigment concentration of the pigment dispersion is 10 to 50.
g / l, and the specific conductivity of the bath of the pigment dispersion is adjusted to 1000 μS / cm or less per 10 g / l pigment concentration so that almost no current unrelated to the migration of the pigment flows. Since the electrophoresis is performed, the occurrence of the anodic reaction and the rapid decrease in pH near the film as described above can be suppressed, and abnormal aggregation of the pigment can be prevented. Can be colored without abnormal precipitation. In addition, it is possible to color the desired shade of light and shade over a wide voltage range, and since the pigment is deposited and filled deep into the pores of the film, it has excellent properties such as light resistance, weather resistance, heat resistance, etc. It is possible to obtain a strong and durable bright colored film without detachment of the pigment. In addition, by selecting a pigment, it can be colored in various desired colors such as red, black, and blue, and it can sufficiently meet the needs for multicolor aluminum.

Claims (5)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】 多孔質陽極酸化皮膜を形成したアルミニ
ウム又はアルミニウム合金を、顔料濃度が１０〜５０ｇ
／ｌの範囲内にあり、かつ顔料濃度１０ｇ／ｌ当り１０
００μＳ／ｃｍ以下の比電導度に調整した有機顔料又は
カーボンブラックの顔料分散体の浴中で電気泳動処理
し、多孔質陽極酸化皮膜の細孔深部にまで有機顔料又は
カーボンブラックを析出させ着色することを特徴とする
アルミニウム又はアルミニウム合金の着色方法。1. An aluminum or aluminum alloy having a porous anodic oxide film formed thereon is coated with a pigment having a pigment concentration of 10 to 50 g.
/ G and a pigment concentration of 10 g / l
00μS / cm was electrophoresed in a bath of the following specific electric conductivity adjustment organic pigment or pigment dispersion of the carbon black, colored to exit analyze organic pigment or carbon black to the pores deep porous anodic oxide film A method of coloring aluminum or an aluminum alloy. 【請求項２】 粒子径３〜１５０ｎｍの有機顔料又はカ
ーボンブラックの顔料分散体を用いることを特徴とする
請求項１に記載の着色方法。2. A coloring method according to claim 1, wherein a pigment dispersion of an organic pigment or carbon black having a particle diameter of 3 to 150 nm is used. 【請求項３】 前記顔料分散体の浴中の顔料濃度が１０
〜４０ｇ／ｌであることを特徴とする請求項１又は２に
記載の着色方法。3. The pigment concentration in the bath of the pigment dispersion is 10 %.
The coloring method according to claim 1, wherein the weight is ４０40 g / l. 【請求項４】 前記顔料分散体の浴の温度が１５〜２５
℃であることを特徴とする請求項１乃至３のいずれか一
項に記載の着色方法。4. The temperature of the pigment dispersion bath is from 15 to 25.
The coloring method according to any one of claims 1 to 3, wherein the temperature is ° C. 【請求項５】 前記顔料分散体の浴のｐＨが８．５〜１
０であることを特徴とする請求項１乃至４のいずれか一
項に記載の着色方法。5. The pH of the bath of the pigment dispersion is 8.5-1.
Coloring method according to any one of claims 1 to 4, characterized in that it is zero.