JPWO2005056883A1 - Zinc-based alloy electroplated film with excellent corrosion resistance and plated metal material using the same - Google Patents

Abstract

An object of the present invention is to provide a zinc-based alloy electroplating film having high corrosion resistance comparable to that of Zn—Cr alloy plating without containing chromium having a large environmental load, and a plated metal material using the same. The present invention has excellent corrosion resistance characterized by comprising (A) 30 to 96% by weight of zinc, (B) 2 to 20% by weight of an iron group metal, and (C) 2 to 50% by weight of tungsten. The present invention relates to a zinc-based alloy electroplating film.

Description

  The present invention relates to a zinc-based alloy electroplating film excellent in corrosion resistance and a plated metal material using the same, and can be used in a wide range of fields such as automobiles, home appliances, and building materials.

In response to demands for high corrosion resistance for metal materials used in automobiles, home appliances, building materials, etc., the use of zinc-based plated metal materials in which iron-based materials are coated with zinc or zinc-based alloy plating is expanding. There are various methods of coating zinc on iron-based materials, but as plating, hot dip galvanization, in which the base material is immersed in molten zinc or a zinc alloy, hot dip galvanization, or metallic zinc dissolved in an aqueous solution is used. Electrogalvanizing is known which is deposited by electrolysis to form a plating film. Furthermore, electrogalvanization is classified into an acidic bath and an alkaline bath depending on the liquidity of the plating solution. Acid baths include sulfuric acid baths, ammonium chloride baths, potassium chloride baths, ammonium chloride / potassium eclectic baths, and alkaline baths include cyan baths and zincate baths. However, metal materials that are used in automobiles, home appliances, building materials, etc. and are exposed to harsh environments cannot obtain sufficient corrosion resistance in some cases even if these plated metal materials are used. It is requested. Under such circumstances, zinc-based alloy plating metal materials such as Zn—Fe, Zn—Ni, and Zn—Cr have been developed. Among these, it has been disclosed that Zn—Cr alloy plating has high corrosion resistance. (For example, refer to Patent Document 1, Patent Document 2, Patent Document 3, etc.).
Zn-Cr alloy plating has a remarkable effect of suppressing corrosion due to Cr present in the film, and the film does not passivate and maintains a relatively low potential, so that the so-called sacrificial anticorrosive action is also long-lasting. It is effective over a long period of time and has excellent corrosion resistance even under conditions where the steel is exposed.
Thus, although Zn—Cr alloy plating is excellent in practical use, there is a problem of hexavalent chromium mist generated during plating, which causes an obstacle to the health and air pollution of plating workers. The problem is close up. Therefore, there is an urgent need to develop and put into practical use an alternative metal material with low environmental impact and high corrosion resistance.
JP-A 64-55397 Japanese Patent Publication No. 2-51996 Japanese Examined Patent Publication No. 3-240994

An object of the present invention is to provide a zinc-based alloy electroplating film having high corrosion resistance comparable to that of Zn—Cr alloy plating without containing chromium with a large environmental load, and a plated metal material using the same.
As a result of intensive studies to solve the above problems, the present inventors have found that the corrosion resistance can be remarkably improved by using zinc as a base and containing a specific amount of iron group metal and tungsten as a plating film. The present invention has been completed.
Thus, the present invention provides (A) 30 to 96% by weight of zinc,
(B) 2-20% by weight of iron group metal and (C) 2-50% by weight of tungsten
The present invention relates to a zinc-based alloy electroplating film excellent in corrosion resistance, characterized in that it contains.
The present invention also relates to a plated metal material having the zinc-based alloy electroplated film.

The zinc-based alloy electroplating film of the present invention contains zinc (A), iron group metal (B) and tungsten (C) as essential components.
The composition of the plating film is 30 to 96% by weight of zinc (A), preferably 50 to 90% by weight, 2 to 20% by weight of iron group metal (B), preferably 5 to 15% by weight and tungsten from the viewpoint of corrosion resistance. (C) It exists in the range of 2-50 weight% and 3-20 weight%.
Here, the iron group metal (B) means iron, cobalt and nickel. Although an alloy plating film of zinc and an iron group metal is generally known, the corrosion resistance of the obtained alloy plating film is remarkably improved by further combining tungsten here. In particular, the use of iron as the iron group metal (B) has a large effect, and it is preferable to use this, but a system using cobalt and / or nickel in combination with iron also has good corrosion resistance.
The zinc-based alloy electroplating film of the present invention uses a plating solution containing Zn ions (a), iron group metal ions (b) and W ions (c), which will be described below, to perform primary forming of steel strips and the like. Products can be electroplated continuously, and secondary molded products including small parts such as bolts and press-molded products can be accommodated in a perforated container such as a rotatable barrel or basket and electroplated. It is formed.
"Zn ion (a)"
Zn ions which are the component (a) of the plating solution constitute the main component of the plating layer.
Zn ions are added to the plating bath in the form of chloride, sulfate, fluoride, cyanide, oxide, organic acid salt, phosphate or simple metal.
"Iron group metal ions (b)"
The iron group metal ions which are the component (b) of the plating solution are selected from Ni ions, Co ions and Fe ions.
The iron group element ion (b) is added to the plating bath in the form of chloride, sulfate, fluoride, cyanide, oxide, organic acid salt, phosphate or simple metal.
"W ion (c)"
W ions as component (c) of the plating solution are added to the plating bath in the form of a tungstic acid compound.
Examples of tungstic acid compounds include tungstic acid, tungstate, phosphotungstic acid, and phosphotungstate. Examples of salts include ammonium, potassium, calcium, and sodium salts. it can. Among these, sodium tungstate and ammonium tungstate are particularly preferable from the viewpoint of corrosion resistance.
"Plating solution"
Metal ions other than the above (a), (b) and (c), for example, Mg, Mn, Ti, Pb, Al, P, etc. may be added to the plating solution.
Moreover, it is preferable to add a complexing agent for allowing the metal ions to exist stably in the plating solution to the plating solution. Examples of the complexing agent include oxycarboxylates such as citrate, tartrate, and gluconate, amino alcohols such as monoethanolamine, diethanolamine, and triethanolamine, ethylenediamine (EDA), diethylenetriamine, and triethylenetetramine. Polyamines, aminocarboxylates such as ethylenediaminetetraacetate and nitroacetate, polyhydric alcohols such as sorbit and pentaerythritol, and mixtures thereof.
In the present invention, by combining a corrosion-inhibiting pigment and / or ceramic particles that can be precipitated as discontinuous particles from the electroplating solution, functions such as high corrosion resistance and paint adhesion can be imparted.
As the corrosion-inhibiting pigment, generally known pigments can be used. Preferred examples include phosphates, molybdates, metaborates, silicates, and the like.
Examples of the ceramic particles include oxides such as Al ₂ O ₃ , SiO ₂ , TiO ₂ , ZrO ₂ , Y ₂ O ₂ , ThO ₂ , CeO ₂ , and Fe ₂ O ₃ ; B ₄ C, SiC, WC, Carbides such as ZrC, TiC, graphite, fluorinated graphite; nitrides such as BN, Si ₃ N, TiN; borides such as Cr ₃ B ₂ , ZrB ₂ ; 2MgO · SiO ₂ , MgO · SiO ₂ , ZrO ₂ · Examples thereof include silicates such as SiO ₂ . The blending amount of the corrosion-inhibiting pigment and / or ceramic particles in the plating bath is preferably in the range of 5 to 500 g per liter. In addition, the smaller the size of the particles, the better the dispersion stability. Therefore, ultrafine particles of 1 μm or less are preferable. Further, the amount of eutectoid in the plating matrix is preferably in the range of 1 to 30% by weight, particularly 1 to 10% by weight with respect to the total amount of precipitation. When the amount of eutectoid is small, the effect of improving the corrosion resistance is not exhibited, and when it exceeds 30% by weight, the plating film becomes brittle or the adhesion with the substrate is lowered, which causes a problem.
In order to improve corrosion resistance, a corrosion-inhibiting organic compound may be further added to the plating bath. Preferred examples of the corrosion-inhibiting organic compound include alkynes, alkynols, amines or salts thereof, thio compounds, aromatic carboxylic acid compounds or salts thereof, and heterocyclic compounds.
Among these, alkynes are organic compounds containing a carbon-carbon triple bond, and examples thereof include pentine, hexyne, heptin, octyne and the like.
Alkynols are organic compounds having one or more hydroxyl groups in the alkynes, and examples thereof include propargyl alcohol, 1-hexyn-3-ol, 1-heptin-3-ol, and the like.
An amine means an organic compound containing one or more nitrogen atoms in the molecule, and includes both aliphatic and aromatic compounds. Examples of such amines include octylamine, nonylamine, decylamine, laurylamine, tridecylamine, cetylamine and the like.
The thio compound means an organic compound containing one or more sulfur atoms in the molecule. Examples of such a thio compound include decyl mercaptan, cetyl mercaptan, thiourea and the like.
A heterocyclic compound means an organic compound containing atoms other than carbon as a ring constituent element in a cyclic molecule. Examples of such a heterocyclic compound include pyridine, benzothiazole, benzotriazole, quinoline, And indole.
Examples of the aromatic carboxylic acid compound include benzoic acid, salicylic acid, toluic acid, and naphthalenecarboxylic acid.
In addition, about amines and a carboxylic acid compound, it is also possible to use the salt, and an equivalent effect can be acquired also in this case. As the salt, in the case of amines, acid addition salts such as sulfates and hydrochlorides, and in the case of aromatic carboxylic acid compounds, metal salts such as alkali metal salts and zinc salts and ammonium salts can be used.
The amount of the corrosion-inhibiting organic compound added to the plating bath is 0.1 to 10% by weight for alkynes and alkynols, 3 to 10% by weight for amines or salts thereof, It is desirable to adjust to 0.2 to 5% by weight for compounds, 1 to 10% by weight for heterocyclic compounds, and 3 to 8% by weight for aromatic carboxylic acid compounds or salts thereof. By using a plating bath to which such a corrosion-inhibiting organic compound is added, a plating film with a C (carbon) content of eutectoid of 0.001 to 10% by weight can be formed on the metal material. The amount can be measured by a combustion method, for example, a “CS analyzer” that measures the absorbance of the generated CO _{2 in} the infrared absorption band by burning organic substances.
The plating solution may contain additives that are commonly used for the purpose of improving burnability at a high current density and improving throwing power at a low current density. Examples of these include amine and epihalohydrin reactants, polyethylene polyamines, other quaternary amine polymers, urea, thiourea, gelatin, polyvinyl alcohol, and aldehydes.
The said plating bath composition can form the plating film excellent in corrosion resistance and coating-film adhesiveness by electroplating by the method similar to the past.
As the bath conditions for electroplating, when the plating bath is a sulfuric acid bath, the pH is about 1 to 3, the bath temperature is about 30 to 80 ° C .; When the plating bath is pH, the pH is about 4 to 7 and the bath temperature is 10 to 50 ° C. About: In the case of an alkaline bath, the pH is preferably 12 or more, and the bath temperature is preferably about 10 to 50 ° C., and the plating film thickness is about 0.5 to 10 μm.
"Electroplated metal"
The electroplating metal material of the present invention is obtained by electroplating a metal material using the above electroplating solution composition to form a plating film. Examples of the metal material include materials mainly composed of iron, such as automobiles, home appliances, and building materials processed into shapes such as plates, pipes, joints, clamps, bolts, and nuts.
The electroplating conditions are as described above.
Further, after the electroplating film is formed, the effect of the present invention is further enhanced by post-treatment with an acidic aqueous solution of a compound containing at least one element selected from the group consisting of cobalt, nickel, titanium, and zirconium. I can do it. Examples of the compound containing at least one element selected from the group consisting of cobalt, nickel, titanium, and zirconium include oxides, hydroxides, fluorides, complex fluorides, chlorides, and nitrates of these metal elements. , Sulfates, carbonates, and the like can be used. Specifically, cobalt nitrate, zirconium oxynitrate, titanium hydrofluoric acid, zircon hydrofluoric acid, ammonium titanium hydrofluoride, ammonium zircon ammonium hydrofluoride and the like are preferable. Can be mentioned.
The acidic aqueous solution of the compound containing these metal elements preferably has a pH of 1 or more and less than 7, preferably 3 or more and 6 or less. Acids such as hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, Or pH can be adjusted with alkalis, such as sodium hydroxide, potassium hydroxide, and amines. You may add a complexing agent, a silica particle, etc. to acidic aqueous solution further as needed. The amount of the compound containing a metal element is preferably about 0.001 to 5 mol / l, particularly about 0.01 to 1 mol / l.
In the post-treatment with an acidic aqueous solution, for example, the electroplating film is treated by immersing a metal material in a treatment solution having a bath temperature of 20 to 80 ° C., preferably 30 to 60 ° C. for 5 seconds or more, preferably about 20 to 90 seconds. It can carry out by making it contact with a liquid.
The electroplated metal material thus obtained is usually subjected to a surface treatment, and a paint is applied as necessary. The surface treatment is usually performed with a chromate surface treatment agent or a phosphate surface treatment agent. However, since the electroplated metal material of the present invention is excellent in corrosion resistance, it exhibits excellent corrosion resistance even in combination with a chromium-free environment-friendly surface treatment agent. In order to reduce the environmental load, it is preferable to combine with a chromium-free environment-friendly surface treatment agent.
The paint in the case of applying to the electroplated metal material of the present invention is not particularly limited, and any of the curing methods such as a normal drying type, a thermosetting type, and an active energy ray curable type can be used, Any type of paint such as solvent-based paint, water-based paint, and powder paint may be used. In particular, when the electroplated metal material of the present invention is applied to an automobile, the electrodeposition paint, intermediate coating and top coating are generally applied and baked in order after the phosphate coating is applied to the plating film. It is.

表１における注（＊１）〜（＊６）の原料は各々下記の内容のものである。
（＊１）Ａ１：Ｋ−ＷＨＩＴＥ ８４０Ｅ、テイカ株式会社製、縮合燐酸リン酸アルミニウム系。
（＊２）Ａ２：ＬＦボウセイＺＰ−ＤＬ、キクチカラー株式会社製、リン酸亜鉛系。
（＊３）Ｂ１：シリカ微粒子、平均粒子径約０．０２μｍ。
（＊４）Ｂ２：アルミナ微粒子、平均粒子径約０．０１μｍ。
（＊５）Ｃ１：３−アミノ−１，２，４−トリアゾール。
（＊６）Ｃ２：チオ尿素。
「２．塗装系１」
［実施例１９〜３６および比較例５〜８］
上記表１で得られた各電気めっき鋼板の表面をアルカリ脱脂した後、表面調整（日本パーカライジング社製「プレパレンＺ」を用いたスプレー処理）を行ない、さらにりん酸塩処理（日本パーカライジング社製「パルボンド３１１８」を用いたスプレー処理）を行なった後、水洗及び乾燥してりん酸亜鉛処理（処理皮膜の付着量は１．５ｇ／ｍ^２とした）鋼板を得た。
このようにして得られたりん酸亜鉛処理鋼板に「マジクロン１０００ホワイト」（関西ペイント社製、アクリル−メラミン樹脂系塗料、白色）を乾燥膜厚が３０μｍになるよに塗布し、１６０℃で２０分間焼きつけて試験塗板を得た。
得られた各試験塗板について、下記試験方法に基いて各種試験を行った。その結果を後記表２に示す。
（上塗密着性）：試験塗板を約９８℃の沸騰水中に２時間浸漬し、引き上げて室温に２時間放置後、この塗装板の塗膜面にナイフにて素地に達する縦横各１１本の傷を碁盤目状にいれて２ｍｍ角の桝目を１００個作成した。この碁盤目部にセロハン粘着テープを密着させて瞬時にテープを剥がした際の塗膜の剥離面積を下記基準により評価した。
５：塗膜の剥離が全く認められない。
４：塗膜の剥離は認められるが、剥離面積が１０％未満。
３：剥離面積が１０％以上で２５％未満。
２：剥離面積が２５％以上で５０％未満。
１：剥離面積が５０％以上。
（塗装後耐食性）：試験塗板に素地に達するクロスカットを入れ、これをＪＩＳＺ−２３７１に準じて２４０時間塩水噴霧試験を行った後、水洗、乾燥させ、クロスカット部にセロハン粘着テープを密着させて瞬時にテープを剥がした時のクロスカット部からの最大剥離幅（片側、ｍｍ）を測定した。

「３．塗装系２」
［実施例３７〜５４、比較例９〜１２］
前記表１で得られた各電気めっき鋼板を湯洗 → 脱脂（日本パーカライジング社製アルカリ脱脂剤「ファインＬ−４４６０」を使用し、４３℃で１２０秒間スプレー） → 水洗 → 表面調整（日本パーカライジング社製チタンコロイド系表面調整剤「プレパレンＺＮ」を使用し、常温で３０秒間スプレー） → りん酸亜鉛系化成処理（日本パーカライジング社製りん酸亜鉛化成処理剤「バルボンドＬ−３０２０」を使用し、４３℃で１２０秒間スプレー） → 水洗 → 水きり乾燥させることによりりん酸塩処理を行ない、ついでカチオン電着塗料「エレクロンＧＴ−１０」（関西ペイント社製、エポキシポリエステル樹脂系カチオン型電着塗料）を電着塗装し、１７０℃で３０分間焼付し、乾燥膜厚２０μｍの電着塗装板を得た。この電着塗装面に中塗り塗料「アミラックＴＰ−６５グレー」（関西ペイント社製、アミノアルキッド樹脂系中塗塗料）を乾燥膜厚が３０μｍになるようにスプレーにて塗装し、１４０℃で３０分間焼きつけた。その後に、上塗塗料ネオアミラック＃６０００ホワイト（関西ペイント社製、アミノアルキッド樹脂系上塗塗料）を乾燥膜厚が３０μｍとなるようにスプレーにて塗装し、１４０℃で２０分間焼きつけ、各試験塗板を得た。
得られた各試験塗板について、下記試験方法に基いて各種試験を行った。その結果を後記表３に示す。
（耐チッピング性）：試験塗板を、飛石試験機ＪＡ−４００型（スガ試験機社製チッピング試験装置）の試験片保持台に石の噴出し口に対して直角になるようにして固定し、−２０℃において０．２９４ＭＰｓ（３ｋｇｆ／ｃｍ^２）の圧縮空気により粒度７号の花崗岩砕石５０ｇを塗面に吹き付け、これにより生じた塗膜キズの発生程度を目視で観察し、下記基準で評価した。
◎：キズの大きさはかなり小さく、上塗塗膜がキズつく程度。
○：キズの大きさは小さく、中塗塗膜が露出している程度。
△：キズの大きさは小さいが、素地の鋼板が露出している。
×：キズの大きさはかなり大きく、素地の鋼板も大きく露出している。
（耐水２次密着性）：試験塗板を４０℃の温水に１０日間浸漬した後、取り出して乾燥させ、この試験塗板の塗膜面にナイフにて素地に達する縦横各１１本の傷を碁盤目状にいれて２ｍｍ角の桝目を１００個作成した。この碁盤目部にセロハン粘着テープを密着させて瞬間にテープを剥がした際の塗膜の剥離面積を下記基準により評価した。
５：塗膜の剥離が全く認められない。
４：塗膜の剥離が認められるが、剥離面積が１０％未満。
３：剥離面積が１０％以上で２５％未満。
２：剥離面積が２５％以上で５０％未満。
１：剥離面積が５０％以上。
（耐食性）：試験塗板に素地に達するクロスカットを入れ、これをＪＩＳ Ｚ−２３７１に準じて７２０時間の塩水噴霧試験を行った後、水洗、風乾させ、一般部のサビ、フクレを下記基準で評価するとともに、クロスカット部にセロハン粘着テープを密着させ瞬時に剥がした時のクロスカット部からの最大剥離幅（片側、ｍｍ）を測定した。
○：塗面にサビ、フクレ等の発生が全く認められない。
△：塗面にサビ、フクレ等の発生が僅かに認められる。
×：塗面にサビ、フクレ等の発生が著しく認められる。
（耐塩水ディップ性）：試験塗板に素地まで達するクロスカットを入れ、これを５％の食塩水に５０℃で１０日間浸漬した後、水洗、風乾させ、一般部のサビ、フクレを下記基準で評価するとともに、クロスカット部にセロハン粘着テープを密着させ瞬時に剥がした時のクロスカット部からの最大剥離幅（片側、ｍｍ）を測定した。
○：塗面にサビ、フクレ等の発生が全く認められない。
△：塗面にサビ、フクレ等の発生が僅かに認められる。
×：塗面にサビ、フクレ等の発生が著しく認められる。

「４．塗装系３」
［実施例５５〜７２、比較例１３〜１６］
前記表１で得られためっき鋼板の表面をアルカリ脱脂した後、その上に下記処方で作成したチタン系下地処理剤を乾燥膜厚が０．５μｍとなるようにバーコーターで塗装し、ＰＭＴ（鋼板の最高到達温度）が１００℃となる条件にて１０秒間加熱して、下地処理板を作成した。ついで、この処理板に「ＫＰカラー８０００プライマー」（関西ペイント社製、変性エポキシ樹脂系塗料）を乾燥膜厚が５μｍとなるようにバーコーターで塗装し、ＰＭＴが２１０℃となる条件で２０秒間加熱して塗膜を形成し、ついでこのプライマー皮膜上に「ＫＰカラー１５８０ホワイト」（関西ペイント社製、ポリエステル樹脂系塗料）を乾燥膜厚が１５μｍとなるようにバーコーターで塗装し、ＰＭＴが２１５℃となる条件で４０秒間加熱して上層塗膜を有する各試験塗板を作成した。
これらの各試験塗板について、塗膜の密着性、耐食性及び耐湿性の試験を行った。その試験結果を表４に示した。各試験は下記の試験方法に従って行った。
＜チタン系下地処理剤の処方＞
テトラｉｓｏ−プロポキシチタン１０部とｉｓｏ−プロパノール１０部の混合物を３０％過酸化水素水１０部と脱イオン水１００部の混合物中に２０℃で１時間かけて攪拌しながら滴下し、その後２５℃で２時間熟成することにより２％チタン化合物水溶液を得た。得られた２％チタン化合物水溶液５０部に２０％ジルコン弗化水素酸５部及び脱イオン水４５部を配合することによりチタン系下地処理剤を得た。
（塗膜の密着性）：試験塗板の塗膜面にナイフで素地に達する縦横１１本の傷を碁盤目状に入れて１ｍｍ角の桝目を１００個作成した。この碁盤目部にセロハン粘着テープを密着させて瞬時にテープを剥がした際の塗膜の剥離程度を下記基準により評価した。
５：塗膜の剥離が全く認められない。
４：塗膜の剥離は認められるが、剥離面積が１０％未満。
３：剥離面積が１０％以上で２５％未満。
２：剥離面積が２５％以上で５０％未満。
１：剥離面積が５０％以上。
（耐食性）：７０ｍｍ×１５０ｍｍの大きさに切断した試験塗板の端面部及び裏面部をシールした後、試験塗板の上部に４Ｔ折り曲げ部（塗膜面を外側にして０．８ｍｍ厚さのスペーサー４枚を挟んで１８０度折り曲げ加工した部分）を設け、試験塗板の下部にクロスカット部を設けた後、該試験塗板についてＪＩＳ Ｚ−２３７１に規定する塩水噴霧試験を１０００時間行なった。試験後の試験塗板における、４Ｔ折り曲げ部の白錆の発生程度、クロスカット部のふくれ幅、一般部（加工、カットのない部分）のふくれ発生程度を下記基準で評価した。
一般部：
◎：ふくれの発生が認められない。
○：ふくれの発生が僅かに認められる。
△：ふくれの発生がかなり認められる。
×：ふくれの発生が著しく、一部に塗膜の剥離が認められる。
クロスカット部：
◎：クロスカットからの片面ふくれ幅が１ｍｍ未満。、
○：クロスカットからの片面ふくれ幅が１ｍｍ以上で２ｍｍ未満。
△：クロスカットからの片面ふくれ幅が２ｍｍ以上で５ｍｍ未満。
×：クロスカットからの片面ふくれ幅が５ｍｍ以上。
４Ｔ折り曲げ部：
◎：白錆の発生が認められない。
○：白錆の発生が僅かに認められる。
△：白錆の発生がかなり認められる。
×：白錆の発生が著しく、一部に塗膜の剥離が認められる。
（耐湿性）：７０ｍｍ×１５０ｍｍの大きさに切断した試験塗板の端面部及び裏面部をシールした後、ＪＩＳ Ｋ−５４００ ９．２．２に準じて試験を行った。耐湿試験機ボックス内の温度が５０℃及び相対湿度が９５〜１００％の条件で試験時間は１０００時間とした。試験後の試験塗板における塗膜のふくれ発生程度を下記基準により評価した。
◎：ふくれの発生が認められない。
○：ふくれの発生が僅かに認められる。
△：ふくれの発生がかなり認められる。
×：ふくれの発生が著しく、一部に塗膜の剥離が認められる。

「５．塗装系４」
［実施例７３〜９０及び比較例１７〜２０］
鋼製ボルトをアルカリ脱脂し、水洗した後、１％硫酸液に室温で３０秒間浸漬して活性化処理を行なった。その後バッチ式バレルめっき装置を使用して、表１に示す所定の金属イオン、腐食抑制顔料、腐食抑制有機化合物及びセラミックス粒子を含有するアルカリ性めっき浴にてめっきを施した。皮膜の組成は、めっき浴中の金属イオン濃度比、電流密度及び浴温度を変えることにより調整し、また、めっき膜厚はめっき時間を適宜選択することによりコントロールした。その後、ＨＮＯ_３ ５ｇ／ｌ及び（ＮＨ_４）_２ＺｒＦ_６ １５ｇ／ｌからなる酸性水溶液に５０℃で３０秒間浸漬することにより後処理を行なって試験用ボルトを作成し、下記方法で耐食性の評価を行なった。評価結果を表５に記す。
（耐食性）：ＪＩＳ Ｚ２３７１に準拠して塩水噴霧試験（ＳＳＴ）を実施し、耐食性は、白錆１０％および赤錆５％の発生時間により評価した。

本発明を詳細にまた特定の実施態様を参照して説明したが、本発明の精神と範囲を逸脱することなく様々な変更や修正を加えることができることは当業者にとって明らかである。
本出願は、２００３年１２月９日出願の日本特許出願（特願２００３−４１０７４６）に基づくものであり、その内容はここに参照として取り込まれる。Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. Hereinafter, both “parts” and “%” are based on weight.
"1. Creation of electroplated steel sheet"
[Examples 1 to 18 and Comparative Examples 1 to 4]
A cold-rolled steel sheet having a plate thickness of 0.8 mm and a size of 70 mm × 150 mm is degreased with alkali, washed with water, and using an electroplating experimental apparatus, predetermined metal ions, corrosion-inhibiting pigments, corrosion-inhibiting organic compounds, and ceramic particles are added. Plating was performed in the contained acidic plating bath. The composition of the film was adjusted by changing the metal ion concentration ratio, current density and bath temperature in the plating bath, and the plating film thickness was controlled by appropriately selecting the plating time. Table 1 below shows the coating composition (wt%) and the film thickness of the plating layers studied. The coating composition and film thickness of the plating layer were measured with a fluorescent X-ray analyzer SEA5200 (manufactured by Seiko Instruments Inc.).
In addition, each metal ion used for the test was supplied from the following compound.
Zn; ZnSO ₄ · 7H ₂ O
_Fe; FeSO 4 · _7H 2 O
_Co; CoSO 4 · _7H 2 O
_Ni; NiSO 4 · _7H 2 O
_{W; Na 2 WO 4 · 2H} 2 O

The raw materials of the notes (* 1) to (* 6) in Table 1 are as follows.
(* 1) A1: K-WHITE 840E, manufactured by Teika Co., Ltd., condensed aluminum phosphate phosphate system.
(* 2) A2: LF Bousei ZP-DL, manufactured by Kikuchi Color Co., Ltd., zinc phosphate system.
(* 3) B1: Silica fine particles, average particle size of about 0.02 μm.
(* 4) B2: Alumina fine particles, average particle diameter of about 0.01 μm.
(* 5) C1: 3-amino-1,2,4-triazole.
(* 6) C2: Thiourea.
"2. Paint system 1"
[Examples 19 to 36 and Comparative Examples 5 to 8]
After alkaline degreasing the surface of each electroplated steel sheet obtained in Table 1 above, surface adjustment (spray treatment using “Preparen Z” manufactured by Nihon Parkerizing Co., Ltd.) was performed, and phosphate treatment (manufactured by Nihon Parkerizing Co., Ltd. “ After performing spray treatment using Palbond 3118 ”, washing with water and drying were performed to obtain a zinc phosphate-treated steel sheet (the amount of the treated film deposited was 1.5 g / m ² ).
“Magiclon 1000 White” (manufactured by Kansai Paint Co., Ltd., acrylic-melamine resin-based paint, white) was applied to the zinc phosphate-treated steel sheet thus obtained so that the dry film thickness was 30 μm. A test coating was obtained by baking for a minute.
About each obtained test coating board, various tests were done based on the following test method. The results are shown in Table 2 below.
(Top coat adhesion): The test coating plate was dipped in boiling water at about 98 ° C. for 2 hours, pulled up and allowed to stand at room temperature for 2 hours. Was put in a grid pattern to make 100 squares of 2 mm square. The cellophane adhesive tape was brought into close contact with the grid area, and the peeled area of the coating film when the tape was instantaneously peeled was evaluated according to the following criteria.
5: No peeling of the coating film is observed.
4: Although peeling of the coating film is observed, the peeling area is less than 10%.
3: The peeled area is 10% or more and less than 25%.
2: The peeled area is 25% or more and less than 50%.
1: The peeling area is 50% or more.
(Corrosion resistance after painting): Put a cross cut reaching the base on the test coating plate, and after performing a salt spray test for 240 hours according to JISZ-2371, wash with water and dry, and attach the cellophane adhesive tape to the cross cut part. The maximum peel width (one side, mm) from the crosscut portion when the tape was peeled off instantaneously was measured.

"3. Paint system 2"
[Examples 37 to 54, Comparative Examples 9 to 12]
Each electroplated steel sheet obtained in Table 1 was washed with hot water → degreased (using Alkali degreasing agent “Fine L-4460” manufactured by Nihon Parkerizing Co., Ltd., sprayed at 43 ° C. for 120 seconds) → water washing → surface conditioning (Nihon Parkerizing Co., Ltd.) Titanium colloid-based surface conditioner “preparen ZN” is used and sprayed at room temperature for 30 seconds) → Zinc phosphate-based chemical conversion treatment (Zinc phosphate chemical conversion treatment “Valbond L-3020” manufactured by Nihon Parkerizing Co., Ltd.) Spray at 120 ° C for 120 seconds) → Wash with water → Phosphate treatment by drying with water, then apply cationic electrocoating paint “Electron GT-10” (Kansai Paint Co., Ltd., epoxy polyester resin cationic electrocoating paint) It was coated and baked at 170 ° C. for 30 minutes to obtain an electrodeposition coated plate having a dry film thickness of 20 μm. On this electrodeposited surface, an intermediate coating “Amirac TP-65 Gray” (manufactured by Kansai Paint Co., Ltd., amino alkyd resin-based intermediate coating) is applied by spraying to a dry film thickness of 30 μm, and at 140 ° C. for 30 minutes. I baked it. After that, the top coat Neoamylac # 6000 White (manufactured by Kansai Paint Co., Ltd., amino alkyd resin-based top coat) was applied by spraying to a dry film thickness of 30 μm, and baked at 140 ° C. for 20 minutes to obtain each test coating plate. It was.
About each obtained test coating board, various tests were done based on the following test method. The results are shown in Table 3 below.
(Chipping resistance): The test coating plate is fixed to the test piece holder of the stepping stone tester JA-400 (Chipping Tester manufactured by Suga Test Instruments Co., Ltd.) so as to be perpendicular to the stone outlet, At -20 ° C, 50g of granite crushed stone was sprayed onto the coating surface with compressed air of 0.294MPs (3kgf / cm ² ), and the degree of occurrence of scratches on the coating film was visually observed and evaluated according to the following criteria. did.
A: The size of the scratch is quite small and the top coating film is scratched.
○: The size of the scratch is small and the intermediate coating film is exposed.
(Triangle | delta): Although the magnitude | size of a crack is small, the base steel plate is exposed.
X: The size of the scratch is quite large, and the base steel plate is also greatly exposed.
(Water-resistant secondary adhesion): The test coating plate was dipped in warm water of 40 ° C. for 10 days, then taken out and dried, and 11 vertical and horizontal scratches reaching the substrate with a knife on the surface of the test coating plate were cut off. 100 squares of 2 mm square were prepared. The cellophane pressure-sensitive adhesive tape was brought into close contact with the grid area, and the peeled area of the coating film when the tape was instantaneously peeled was evaluated according to the following criteria.
5: No peeling of the coating film is observed.
4: Although peeling of the coating film is observed, the peeling area is less than 10%.
3: The peeled area is 10% or more and less than 25%.
2: The peeled area is 25% or more and less than 50%.
1: The peeling area is 50% or more.
(Corrosion resistance): A cross-cut reaching the substrate is put on the test coating plate, and this is subjected to a salt spray test for 720 hours in accordance with JIS Z-2371, followed by washing with water and air drying. While evaluating, the cellophane adhesive tape was closely_contact | adhered to the crosscut part, and the largest peeling width (one side, mm) from the crosscut part when it peeled off instantaneously was measured.
○: No rust, swelling or the like is observed on the coated surface.
Δ: Rust, swelling, etc. are slightly observed on the coated surface.
X: The occurrence of rust and swelling on the coated surface is remarkably observed.
(Salt water dip resistance): Put a cross-cut reaching the substrate on the test coating plate, soak it in 5% saline solution at 50 ° C for 10 days, then wash with water and air dry. While evaluating, the cellophane adhesive tape was closely_contact | adhered to the crosscut part, and the largest peeling width (one side, mm) from the crosscut part when it peeled off instantaneously was measured.
○: No rust, swelling or the like is observed on the coated surface.
Δ: Rust, swelling, etc. are slightly observed on the coated surface.
X: The occurrence of rust and swelling on the coated surface is remarkably observed.

"4. Paint system 3"
[Examples 55 to 72, Comparative Examples 13 to 16]
After the surface of the plated steel sheet obtained in Table 1 was degreased with alkali, a titanium-based base treatment agent prepared according to the following formulation was applied thereon with a bar coater so that the dry film thickness was 0.5 μm, and PMT ( The substrate was heated for 10 seconds under the condition that the maximum temperature of the steel plate was 100 ° C. to prepare a base treatment plate. Next, “KP color 8000 primer” (modified epoxy resin-based paint, manufactured by Kansai Paint Co., Ltd.) was applied to the treated plate with a bar coater so that the dry film thickness was 5 μm, and the PMT was 210 ° C. for 20 seconds. A film was formed by heating, and then “KP Color 1580 White” (polyester resin-based paint manufactured by Kansai Paint Co., Ltd.) was applied on the primer film with a bar coater so that the dry film thickness was 15 μm. Each test coating plate having an upper coating film was prepared by heating for 40 seconds under conditions of 215 ° C.
About each of these test coating plates, the test of the adhesiveness of a coating film, corrosion resistance, and moisture resistance was done. The test results are shown in Table 4. Each test was performed according to the following test method.
<Prescription of titanium base treatment agent>
A mixture of 10 parts of tetraiso-propoxytitanium and 10 parts of iso-propanol was dropped into a mixture of 10 parts of 30% hydrogen peroxide and 100 parts of deionized water at 20 ° C. with stirring for 1 hour, and then 25 ° C. For 2 hours to obtain a 2% titanium compound aqueous solution. A titanium-based surface treating agent was obtained by blending 5 parts of 20% zircon hydrofluoric acid and 45 parts of deionized water with 50 parts of the obtained 2% titanium compound aqueous solution.
(Adhesiveness of coating film): Eleven vertical and horizontal scratches reaching the substrate with a knife were put in a grid pattern on the coating film surface of the test coating plate to make 100 1 mm square cells. The degree of peeling of the coating film was evaluated according to the following criteria when the cellophane adhesive tape was brought into close contact with the grid area and the tape was instantaneously peeled off.
5: No peeling of the coating film is observed.
4: Although peeling of the coating film is observed, the peeling area is less than 10%.
3: The peeled area is 10% or more and less than 25%.
2: The peeled area is 25% or more and less than 50%.
1: The peeling area is 50% or more.
(Corrosion resistance): After sealing the end face part and the back face part of the test coating plate cut to a size of 70 mm × 150 mm, a 4T bent part (0.8 mm thick spacer 4 with the coating film surface facing outside) is formed on the upper part of the test coating plate. A portion that was bent 180 degrees across the sheet was provided, and a cross-cut portion was provided at the lower portion of the test coating plate. Then, a salt spray test specified in JIS Z-2371 was performed for 1000 hours on the test coating plate. In the test coated plate after the test, the degree of occurrence of white rust at the 4T bent part, the width of the cross cut part, and the degree of blistering of the general part (the part without processing and cutting) were evaluated according to the following criteria.
General part:
A: No blistering is observed.
○: Swelling is slightly observed.
(Triangle | delta): Generation | occurrence | production of a blister is recognized considerably.
X: The occurrence of blistering is remarkable and peeling of the coating film is observed in part.
Cross cut part:
(Double-circle): The single-sided blistering width from a crosscut is less than 1 mm. ,
○: One-sided blistering width from cross cut is 1 mm or more and less than 2 mm.
(Triangle | delta): The single-sided blistering width from a crosscut is 2 mm or more and less than 5 mm.
X: The single-sided blister width from the cross cut is 5 mm or more.
4T bent part:
A: White rust is not observed.
○: Slightly white rust is observed.
(Triangle | delta): Generation | occurrence | production of white rust is recognized considerably.
X: The occurrence of white rust is remarkable and peeling of the coating film is observed in part.
(Moisture resistance): After sealing the end surface part and the back surface part of the test coating plate cut to a size of 70 mm × 150 mm, the test was performed according to JIS K-5400 9.2.2. The test time was 1000 hours under the conditions that the temperature in the moisture resistance tester box was 50 ° C. and the relative humidity was 95 to 100%. The degree of blistering of the coating film on the test coating plate after the test was evaluated according to the following criteria.
A: No blistering is observed.
○: Swelling is slightly observed.
(Triangle | delta): Generation | occurrence | production of a blister is recognized considerably.
X: The occurrence of blistering is remarkable and peeling of the coating film is observed in part.

"5. Paint system 4"
[Examples 73 to 90 and Comparative Examples 17 to 20]
The steel bolt was degreased with alkali, washed with water, and then immersed in 1% sulfuric acid solution at room temperature for 30 seconds for activation treatment. Thereafter, using a batch type barrel plating apparatus, plating was performed in an alkaline plating bath containing predetermined metal ions, corrosion-inhibiting pigments, corrosion-inhibiting organic compounds and ceramic particles shown in Table 1. The composition of the coating was adjusted by changing the metal ion concentration ratio, current density and bath temperature in the plating bath, and the plating film thickness was controlled by appropriately selecting the plating time. Thereafter, a test bolt was prepared by performing post-treatment by immersing in an acidic aqueous solution composed of 5 g / l of HNO ₃ and 15 g / l of (NH ₄ ) ₂ ZrF ₆ at 50 ° C., and corrosion resistance was evaluated by the following method. Was done. The evaluation results are shown in Table 5.
(Corrosion resistance): A salt spray test (SST) was performed in accordance with JIS Z2371, and the corrosion resistance was evaluated by the generation time of white rust 10% and red rust 5%.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application (Japanese Patent Application No. 2003-410746) filed on Dec. 9, 2003, the contents of which are incorporated herein by reference.

  The zinc-based alloy electroplating film of the present invention contains a specific amount of iron group metal and tungsten with respect to zinc, and has significantly improved corrosion resistance as compared with conventional zinc and zinc alloy plating films. A plated metal material having a zinc-based alloy electroplated film is particularly useful as a metal member for automobiles.

Claims (8)

(A) Zinc 30 to 96% by weight,
(B) 2-20% by weight of iron group metal and (C) 2-50% by weight of tungsten
A zinc-based alloy electroplating film excellent in corrosion resistance, characterized by comprising The zinc-based alloy electroplating film according to claim 1, wherein the iron group metal (B) is iron. The zinc-based alloy electroplating film according to claim 1 or 2, further comprising 1 to 30 wt% of a corrosion-inhibiting pigment and / or ceramic particles in the plating film. The zinc-based alloy electroplating film according to claim 3, wherein the corrosion-inhibiting pigment is at least one selected from the group consisting of phosphate, molybdate, metaborate and silicate. Ceramic particles are Al ₂ O ₃ , SiO ₂ , TiO ₂ , ZrO ₂ , Y ₂ O ₂ , ThO ₂ , CeO ₂ , Fe ₂ O ₃ , B ₄ C, SiC, WC, ZrC, TiC, graphite, fluoride. The at least one particle selected from the group consisting of graphite, BN, Si ₃ N ₄ , TiN, Cr ₃ B ₂ , ZrB ₂ , 2MgO · SiO ₂ , MgO · SiO ₂ , and ZrO ₂ · SiO _2. 3. The zinc-based alloy electroplating film according to 3. Further, at least one organic compound selected from the group consisting of alkynes, alkynols, amines or salts thereof, thio compounds, aromatic carboxylic acid compounds or salts thereof, and heterocyclic compounds is added to C (carbon). The zinc-based alloy electroplating film according to any one of claims 1 to 5, which is contained in an amount of 0.001 to 10% by weight. A plated metal material comprising the electroplated zinc-based alloy according to any one of claims 1 to 6. A compound containing at least one element selected from the group consisting of cobalt, nickel, titanium and zirconium after the zinc-based alloy electroplating film according to any one of claims 1 to 6 is formed on a metal material. A plated metal material obtained by contacting with an acidic aqueous solution.