JP4856802B2 - Metal surface treatment method - Google Patents

Description

【００１４】
（式中、Ｒ１、Ｒ２はそれぞれ水素、メチル、エチル、ブチル又はイソブチルを表し、Ｒ３はＣＨ₂、Ｃ₂Ｈ₄又はＣ₃Ｈ₆を表す）で表されるポリマー、構造式（２）
【００１５】
【化２】

【００１６】
（式中、Ｒ１、Ｒ２は水素、メチル、エチル、イソプロピル、ブチル、−ＣＨ₂ＣＨ₂（ＯＣＨ₂ＣＨ₂）ＸＯＨ（Ｘは０〜５）又は−ＣＨ₂ＣＨ₂（ＯＣＣＨ₂ＣＨ₂）ＸＯＨ（Ｘは０〜５）を表す）で表されるポリマー、構造式（３）
【００１７】
【化３】

【００１８】
（式中、Ｒ１、Ｒ２、Ｒ３及びＲ４はそれぞれ水素、メチル、エチル、イソプロピル、２−ヒドロキシエチル−ＣＨ₂ＣＨ₂（ＯＣＨ₂ＣＨ₂）_XＯＨ（Ｘは０〜６）又は２−ヒドロキシエチル−ＣＨ₂ＣＨ₂（ＯＣＣＨ₂ＣＨ₂）_XＯＨ（Ｘは０〜６）を表し、Ｒ５は（ＣＨ₂）₂−Ｏ−（ＣＨ₂）₂、（ＣＨ₂）₂−Ｏ−（ＣＨ₂）₂−Ｏ−（ＣＨ₂）₂又はＣＨ₂−ＣＨＯＨ−ＣＨ₂−Ｏ−ＣＨ₂−ＣＨＯＨ−ＣＨ₂を表し、ｎは１以上をであり、ＹはＳ又はＯである）で表されるポリマー、構造式（４）
【００１９】
【化４】

【００２０】
（式中、Ｒ１、Ｒ２、Ｒ３及びＲ４ははそれぞれ水素、メチル、エチル、イソプロピル、２−ヒドロキシルエチル−ＣＨ₂ＣＨ₂（ＯＣＨ₂ＣＨ₂）_XＯＨ（Ｘは０〜６）又は２−ヒドロキシルエチル−ＣＨ₂ＣＨ₂（ＯＣＣＨ₂ＣＨ₂）_XＯＨ（Ｘは０〜６）を表し、Ｒ５は（ＣＨ₂）₂−Ｏ−（ＣＨ₂）₂、（ＣＨ₂）₂−Ｏ−（ＣＨ₂）−Ｏ−（ＣＨ₂）₂又はＣＨ₂−ＣＨＯＨ−ＣＨ₂−Ｏ−ＣＨ₂−ＣＨＯＨ−ＣＨ₂を表し、ｎは１以上であり、ＹはＳ又はＯである）で表されるポリマー、構造式（５）
【００２１】
【化５】

【００２２】
（式中、Ｒ１及びＲ２はそれぞれ水素、メチル、エチル、イソプロピル、ブチル、−ＣＨ₂ＣＨ₂（ＯＣＨ₂ＣＨ₂）_XＯＨ（Ｘは０〜５）又は−ＣＨ₂ＣＨ₂（ＯＣＣＨ₂ＣＨ₂）_XＯＨ（Ｘは０〜５）を表し、ｎは１以上であり、ＹはＯ又はＳである）をモノマーとするポリマー、構造式（６）
【００２３】
【化６】

【００２４】
（式中、Ｒ１及びＲ２はそれぞれ水素又は炭素数が１０以下のアルキル基を表す）で表されるポリマー、構造式（７）
【００２５】
【化７】

【００２６】
（式中、Ｒ１、Ｒ２、Ｒ３及びＲ４はそれぞれ水素又は炭素数が５以下のアルキル基を表し、Ｘは無機陰イオンを表し、ＹはＳ又はＯを表す）で表されるポリマー、及び構造式（８）
【００２７】
【化８】

【００２８】
（式中、Ｒ１、Ｒ２、Ｒ３及びＲ４はそれぞれ水素又は炭素数が５以下のアルキル基を表し、Ｘは無機陰イオンを表し、ＹはＳ又はＯを表す）で表されるポリマー等が使用可能である。前記構造式（１）のポリマーの例として旭電化工業（株）から市販されている「アデカカチオエース（商標）ＰＤ−５０」、前記構造式（２）のポリマーの例としてはローヌ・プーラン社から市販されている「ＭＩＲＡＰＯＬ（商標）１００」、前記構造式（３）のポリマーの例としては「ＭＩＲＡＰＯＬ（商標）ＷＴ」、前記構造式（４）のポリマーの例としては「ＭＩＲＡＰＯＬ（商標）ＡＤ−１」、前記構造式（５）のポリマーの例としては「ＭＩＲＡＰＯＬ（商標）５５０」などがある。めっき浴中のこれらのポリマーの総量は１〜５０ｇ／Ｌが好ましい。
【００２９】
アルキレンオキサイド付加化合物の例としては、β−ナフトールエチレンオキサイド付加物、ビスフェノールエチレンオキサイド付加物、ビスフェノールプロピレンオキサイド付加物、エチレンジアミンエチレンオキサイド付加物、エチレンジアミンプロピレンオキサイド付加物、ポリオキシエチレンアルキルアミン、ポリオキシエチレンアミンエステル、プロピレンオキサイドエチレンオキサイドブロックポリマー、ポリオキシエチレンソルビタンエステル、ステアリン酸エチレンオキサイド付加物、ステアリン酸プロピレンオキサイド付加物、ラウリン酸エチレンオキサイド付加物、オレイン酸エチレンオキサイド付加物、オレイン酸プロピレンオキサイド付加物、ポリオキシエチレンオレイルエーテル、ポリオキシエチレンラウリルエーテル、ポリオキシエチレンセチルエーテル、ポリオキシエチレンステアリルエーテル、ポリオキシエチレントリデシルエーテル、ポリオキシエチレンドデシルエーテル、ポリオキシエチレンオクチルフェニルエーテル、ポリオキシエチレンノニルフェニルエーテル等が使用可能である。
【００３０】
カルボン酸化合物の例としてはグルコン酸、酒石酸、エチレンジアミン四酢酸、プロピオン酸、アスパラギン酸、酪酸、酢酸、安息香酸、アルギン酸、アスコルビン酸、ニコチン酸、キノリン酸、サリチル酸、シュウ酸、ソルビン酸、ヘプトン酸、ベラトル酸、アクリル酸、乳酸、没食子酸、グルタル酸、グルタミン酸、クエン酸、及び／又はこれらの塩や誘導体などが使用可能である。
ポリビニルアルコール及びポリビニルアルコール誘導体の例としては市販のポリビニルアルコール、たとえばポバール２０５（（株）クラレ製）やこれらの酸化物、誘導体などが使用可能である。
【００３１】
単糖類の例としてはグルコース、フルクトース、マンノース、ガラクトース、タガトース、ソルボーズ、キソロース、アラビノース、リブロース、キシルロース、リキソース、リボース、デオキシリボース等が使用可能である。
多糖類の例としてはデンプン、セルロース、グリコーゲン、カロニン、ラミナラン、デキスロラン、イヌリン、レバン、ゾウゲヤシマンナン、キシラン、ペクチン酸、グアラン、コンニャクマンナン、ヘパリン、コンドロイチン硫酸、ヒアルロン酸、メスキットガム、ガッチガム、アラビアゴムなどが使用可能である。
アミノ酸、アミノ酸塩の例としてはグルコサミン、ガラクトサミン、アラニン、セリン、アミノ酪酸、トレオニン、バリン、ノルバニン、ロイシン、イソロイシン、シトルリン、フェニルアラニン、チロシン、ジヨードチロシン、ジオキシフェニルアラニン、ジブロムチロシン、プロリン、オキシプロリン、トリプトファン、システイン、シスチン、メチオニン、アルギニン、リジン、オキシリジン、オルニチン、カナバミン、ヒスチジン、これらのナトリウム塩、カリウム塩等が使用可能である。
【００３２】
酸アミド及び酸アミド誘導体の例としてはグルコン酸アミド、酒石酸アミド、プロピオン酸アミド、アスパラギン酸アミド、酪酸アミド、酢酸アミド、安息香酸アミド、アルギン酸アミド、アスコルビン酸アミド、ニコチン酸アミド、キノリン酸アミド、サリチル酸アミド、シュウ酸アミド、ソルビン酸アミド、ヘプトン酸アミド、ベラトル酸アミド、アクリル酸アミド、乳酸アミド、没食子酸アミド、グルタル酸アミド、グルタミン酸アミド、クエン酸アミド及びこれらの誘導体などが使用可能である。
【００３３】
脂肪族アルコールの例としてはメタノール、エタノール、プロパノール、ブタノール、ペンタノール、ヘキサノール、ヘプタノール、オクタノール、ノナノール、デカノール、ウンデカノール、ドデカノール、メチレンジオール、エチレンジオール、プロピレンジオール、ブチレンジオール、ペンタンジオール、ヘキサンジオール、ヘプタンジオール、オクタンジオール、ノナンジオール、デカンジオール、ウンデカンジオール、ドデカンジオール等が使用可能である。
アミノアルコール、アミノアルコールポリマーの例としてはアミノエチルエタノールアミン、アミノプロピルアルコール等及びこれらとエピハロヒドリンの反応物等が使用可能である。
【００３４】
界面活性剤の例としてはジオクチルスルホコハク酸及びその塩、アルキルフェノールエーテルサルフェート及びその塩、ドデシルベンゼンスルホン酸及びその塩、アルキルフェノキシポリオキシアルキレンエチルスルホン酸及びその塩、高級アルコールのポリオキシアルキレンエチルスルホン酸及びその塩等の陰イオン性界面活性剤、Ｎ，Ｎ，Ｎ−トリアルキルアンモニウムクロライド、Ｎ，Ｎ−ジアルキルアンモニウムクロライド、Ｎ−モノアルキルアンモニウムクロライド等の陽イオン性界面活性剤等が使用可能である。
【００３５】
電導塩としては水酸化ナトリウム、水酸化カリウム、塩化アンモニウム、塩化カリウム等が使用可能である。
アルデヒドとしてはバニリン、ベンズアルデヒド、エチルバニリン、ベラトルアルデヒド、アニスアルデヒド、ｏ−クロロベンズアルデヒド、ｐ−クロロベンズアルデヒド、ヘリオトロピンが比較的良好な光沢を付与するものであり、０．００１〜５０ｇ／Ｌ、好ましくは１０〜５０００ｍｇ／Ｌ存在するめっき液により良好なめっき皮膜が提供される。
【００３６】
合金めっきにする場合は鉄、コバルト、ニッケル、三価のクロム、銅、マンガン、アルミニウム、スズから成る群から選択される少なくとも一種が含まれるが、特に鉄、コバルト１ｍｇ／Ｌ〜１ｇ／Ｌ、ニッケル１０ｍｇ／Ｌ〜３０ｇ／Ｌ、マンガン１０ｍｇ／Ｌ〜３０ｇ／Ｌ、スズ１〜１００ｇ／Ｌ、三価のクロム、銅、アルミニウム１ｍｇ／Ｌ〜１０ｇ／Ｌの範囲で少なくとも一種が含まれるのが適当である。
【００３７】
それぞれの量は亜鉛めっきか亜鉛合金めっきかで異なり、亜鉛合金めっきにおいても合金成分により適当な共析比率が異なるため、それぞれに成分量が異なり一概には決定できない。例えば亜鉛めっきの場合、アルカリ浴では亜鉛５〜２０ｇ／Ｌ、水酸化ナトリウム９０〜１５０ｇ／Ｌ、酸性浴では亜鉛１０〜４０ｇ／Ｌ、塩化アンモニウム、塩化カリウムのどちらか一方又は併用する場合は両者の合計が１００〜２５０ｇ／Ｌが一般的に良好な皮膜が得られる範囲である。又、亜鉛−鉄合金めっきの場合、亜鉛６〜２０ｇ／Ｌ、鉄１ｍｇ／Ｌ〜１ｇ／Ｌ、水酸化ナトリウム８５〜１５０ｇ／Ｌが均一な皮膜を得るのに一般的な範囲である。いずれの場合も電流密度や浴温などの条件の影響を受けるため一概に決めることは出来ない。合金成分の供給方法に制限はなく、硫酸鉄、塩化鉄、硫酸コバルト、塩化コバルト、硫酸ニッケル、塩化ニッケル、炭酸ニッケル、硫酸マンガン、塩化マンガン、スズ酸ソーダ、スズ酸カリ、硫酸スズ、硫酸クロム、塩化クロム、硝酸クロム、硫酸銅、塩化銅、炭酸銅、塩化アルミニウム、硝酸アルミニウム等の塩で供給できる。
【００３８】
それぞれの成分のめっき液中における働きは以下の通りである。亜鉛及び合金成分は析出金属として働き、導電塩は電解の際にめっき液に導電性を寄与する。前記ケイ素化合物、脂肪族アミン又はそのポリマー、アルキレンオキサイド付加化合物、カルボン酸化合物、ポリビニルアルコール、ポリビニルアルコール誘導体、単糖類、多糖類、アミノ酸、アミノ酸塩、酸アミド、酸アミド誘導体、脂肪族アルコール、アミノアルコール、アミノアルコールポリマー、界面活性剤、アンモニア、ホウ酸は添加することによりめっき外観において均一な光沢、レベリング、均一電着性、ツキマワリ性等亜鉛めっきの基本的な要求特性を向上するとともに、浴中の不純金属の影響を抑えるものである。更に合金めっきの場合は添加金属を浴中で安定させ、均一な比率での析出を可能にするものである。
【００３９】
また従来のめっき浴は温度に対して弱く、浴温が３０℃を超えると均一電着性に乏しい、光沢が不足しためっき外観となるが、本発明は３０℃を超えるめっき条件でも十分に実用に耐えるものである。
【００４０】
これらの他にも本発明は従来の亜鉛めっきの他の特性も改善されている。例えばツキマワリ性は外観の光沢などと比べ直接目に付かないため見落とされがちであるが、亜鉛めっきを評価するに当たり無視できない重要な性能である。ツキマワリ性とはより低い電流密度域においても有効なめっきを得られる能力である。
近年、クロメート処理の六価クロムが人間の健康や環境に悪影響を与えると問題視され、六価クロムを全く含まない化成皮膜が数多く提案されているが、これらのほとんどは化成力、耐食性において従来のクロメート処理に比べ劣っているものがほとんどであるため、トータルな耐食性を維持するために、より低電流密度にまでめっきを電着させる能力への要求度は日を追う毎に強くなっており、本発明はこの要求を充分に満たすものである。また、本発明では、この能力に限らず、ピット防止やレベリング性などの特性においても、従来の亜鉛めっきを大きく改善するものである。また、これらの浴の中でも特に、導電性塩に水酸化アルカリを含有し、０．４〜４０ｇ／Ｌの脂肪族アミン又はそのポリマー、アルキレンオキサイド化合物、０．５〜４００ｇ／Ｌのカルボン酸化合物、０．０１〜５０ｇ／Ｌのポリビニルアルコールから成る群から選択される少なくとも一種を含有し、合金めっきの場合は合金成分として１ｍｇ／Ｌ〜１ｇ／Ｌの鉄、コバルト、１０ｍｇ／Ｌ〜３０ｇ／Ｌのニッケル、１０ｍｇ／Ｌ〜３０ｇ／Ｌのマンガン、１〜１００ｇ／Ｌのスズから成る群から選択される少なくとも一種を含有する亜鉛又は亜鉛合金めっき浴を用いることによりもっとも良好な上記各特性を得ることが可能になる。
【００４１】
この改質された亜鉛めっき上に更にＬｉ、Ｍｏ、Ｗ、Ｖ、Ｎｂ、Ｔａ、Ｔｉ、Ｚｒ、Ｃｅ、Ｓｒ、Ｆｅ、Ｎｉ、Ａｌ、Ｓｉ、Ｃｏ、Ｂｅ、Ｍｇ、Ｃａ、Ｂａ及び三価のクロムから成る群から選択される少なくとも一種の金属を含有する水性液状組成物により保護皮膜を形成すると、本発明以外の亜鉛めっき上に形成した場合と比較して、大幅に耐食性が向上する。これらの水溶性組成物の中でもＡ）三価のクロムの供給源、Ｂ）酸化性物質の供給源、Ｃ）リンの酸素酸、酸素酸塩又はこれらの無水物を含有するものや、三価クロムイオン並びに塩素イオン、フッ素イオン、硝酸イオン、硫酸イオン及び酢酸イオンから成る群から選択される少なくとも一種を含有するものにより保護皮膜を形成することが特に効果的である。
【００４２】
また、この保護皮膜を形成するにあたり、用途に応じてめっき行程と保護皮膜形成行程の間に活性化処理やフラッシュめっきなどの行程を加えることが出来る。活性化処理とは保護皮膜の化成を促進し、また、めっきへの密着性を向上させるために保護皮膜形成行程の前に薄い硝酸、塩酸、硫酸、過酸化水素等にめっきを浸漬し、めっき表面を活性化させることをいい、フラッシュめっきとは通常のめっき行程の後に保護皮膜が化成しやすい組成のめっきを短時間施すことにより、保護皮膜の化成を促進させ、また、めっきへの密着性を向上させる処理方法である。
【００４３】
水性液状組成物は三価クロムイオン０．０１〜１００ｇ／Ｌ、硝酸イオン及び／又はフッ素イオン０．０１〜１００ｇ／Ｌ及びリンの酸素酸イオンを０．１〜２００ｇ／Ｌ含み、ｐＨを０．５〜４、浴温を５から５０℃に調整したものや、三価クロムイオン０．０１〜１５０ｇ／Ｌ並びに塩素イオン、フッ素イオン、硝酸イオン、硫酸イオン、酢酸イオンから成る群から選択される少なくとも一種を０．０１〜１００ｇ／Ｌ含み、ｐＨを０．５〜４、浴温を５から６０℃に調整したものや、三価クロム、Ｍｏ、Ｔｉ、Ａｌ、Ｓｉ、Ｆｅ、Ｎｉ、Ｍｇ、Ｃａ、Ｃｏから選択される一種以上０．０１〜１００ｇ／Ｌ、硝酸イオン、硫酸イオン、フッ素イオン、リン酸イオンから選択される一種以上０．１〜２００ｇ／Ｌ含み、ｐＨを０．５〜４、浴温を５から８０℃に調整したものを用いると、特に良好な耐食性が得られる。
【００４４】
Ｌｉ、Ｍｏ、Ｗ、Ｖ、Ｎｂ、Ｔａ、Ｔｉ、Ｚｒ、Ｃｅ、Ｓｒ、Ｆｅ、Ｎｉ、Ａｌ、Ｓｉ、Ｃｏ、Ｂｅ、Ｍｇ、Ｃａ、Ｂａ及び三価のクロムの供給源としてはこれらを含む任意の化合物を使用することが可能である。たとえば、水酸化リチウム、塩化リチウム、モリブデン酸、モリブデン酸アンモニウム、モリブデン酸ナトリウム、モリブデン酸カルシウム、塩化モリブデン、チオモリブデン酸アンモニウム、塩化タングステン、けいタングステン酸、タングステン酸、タングステン酸アンモニウム、タングステン酸カルシウム、タングステン酸ナトリウム、リンタングステン酸、リンタングステン酸アンモニウム、リンタングステン酸ナトリウム、酸化バナジウム、バナジン酸、バナジン酸アンモニウム、バナジン酸ナトリウム、メタバナジン酸アンモニウム、メタバナジン酸ナトリウム、塩化ニオブ、ヘキサフルオロニオブ酸アンモニウム、塩化タンタル、タンタルメチラート、塩化チタン、硫酸チタン、塩化ジルコニウム、硫酸ジルコニウム、塩化酸化ジルコニウム、塩化セリウム、硝酸セリウム、酢酸セリウム、シュウ酸セリウム、硝酸アンモニウムセリウム、塩化ストロンチウム、ギ酸ストロンチウム、酢酸ストロンチウム、シュウ酸ストロンチウム、硝酸ストロンチウム、炭酸ストロンチウム、硫酸ストロンチウム、塩化鉄、シュウ酸鉄、硝酸鉄、ピロリン酸鉄、ナフテン酸鉄、硫酸鉄、硫酸アンモニウム鉄、リン酸鉄、安息香酸ニッケル、塩化ニッケル、クエン酸ニッケル、酢酸ニッケル、次亜リン酸ニッケル、臭化ニッケル、シュウ酸ニッケル、硝酸ニッケル、炭酸ニッケル、硫酸ニッケル、硫酸アンモニウムニッケル、塩化アルミニウム、酢酸アルミニウム、臭化アルミニウム、シュウ酸アルミニウム、硝酸アルミニウム、乳酸アルミニウム、ホウ酸アルミニウム、ヨウ化アルミニウム、硫酸アルミニウム、ケイ酸ナトリウム、ケイ酸カリウム、コロイダルシリカ、塩化コバルト、ギ酸コバルト、酢酸コバルト、シュウ酸コバルト、硝酸コバルト、ステアリン酸コバルト、炭酸コバルト、硫酸コバルト、硫酸アンモニウムコバルト、塩化ベリリウム、硫酸ベリリウム、安息香酸マグネシウム、塩化マグネシウム、過塩素酸マグネシウム、酢酸マグネシウム、臭化マグネシウム、シュウ酸マグネシウム、硝酸マグネシウム、乳酸マグネシウム、フッ化マグネシウム、硫酸マグネシウム、硫酸アンモニウムマグネシウム、リン酸マグネシウム、リン酸アンモニウムマグネシウム、亜硝酸カルシウム、亜硫酸カルシウム、亜リン酸カルシウム、安息香酸カルシウム、塩化カルシウム、過酸化カルシウム、ギ酸カルシウム、クエン酸カルシウム、グリセロリン酸カルシウム、グルコン酸カルシウム、酢酸カルシウム、サリチル酸カルシウム、次亜塩素酸カルシウム、臭化カルシウム、シュウ酸カルシウム、ステアリン酸カルシウム、炭酸カルシウム、乳酸カルシウム、リン酸カルシウム、ピロリン酸カルシウム、ホスフィン酸カルシウム、ヨウ化カルシウム、硫酸カルシウム、塩化カルシウム、塩化バリウム、硝酸バリウム、酢酸バリウム、炭酸バリウム、塩化クロム（III）、酢酸クロム（III）、臭化クロム（III）、硝酸クロム（III）、硫酸クロム、（III）、硫酸アンモニウムクロム（III）、リン酸クロム（III）等が使用可能である。
【００４５】
硝酸イオンの供給源はこれを含む任意の化合物、例えば、硝酸、硝酸亜鉛、硝酸アンモニウム、硝酸アンモニウムセリウム、硝酸イットリウム、硝酸インジウム、硝酸ウラニル、硝酸カリウム、硝酸カルシウム、硝酸ナトリウム、硝酸クロム（III）、硝酸ジルコニル、硝酸ストロンチウム、硝酸セシウム、硝酸セリウム、硝酸セリウムアンモニウム、硝酸タリウム、硝酸鉄、硝酸銅、硝酸ナトリウム、硝酸ニッケル、硝酸ネオジウム、硝酸パラジウム、硝酸バリウム、硝酸ビスマス、硝酸マグネシウム、硝酸ユウロピウム、硝酸ランタン、硝酸リチウム、硝酸ルビジウム、硝酸ロジウム等が使用可能である。
【００４６】
フッ素の供給源はこれを含む任意の化合物、例えば、フッ化水素酸、酸性フッ化アンモニウム、フッ化亜鉛、フッ化イットリウム、フッ化カリウム、フッ化カルシウム、フッ化クロム（III）、フッ化ジルコニウムカリウム、フッ化水素カリウム、フッ化ストロンチウム、フッ化セシウム、フッ化チタンカリウム、フッ化銅フッ化ナトリウム、フッ化バリウム、フッ化マグネシウム、フッ化ランタン、フッ化リチウム等が使用可能である。
【００４７】
リンの酸素酸イオンの供給源はこれを含む任意の化合物、例えば、亜リン酸、亜リン酸カルシウム、亜リン酸二カリウム、グアニジンリン酸塩、グリセロリン酸、グリセロリン酸カルシウム、グリセロリン酸ナトリウム、次亜リン酸、次亜リン酸アンモニウム、次亜リン酸カルシウム、次亜リン酸ナトリウム、次亜リン酸ニッケル、タングストリン酸ナトリウム、ナフチルリン酸ナトリウム、二リン酸ナトリウム、ピロリン酸、ピロリン酸亜鉛、ピロリン酸カリウム、ピロリン酸カルシウム、ピロリン酸鉄（III）、ピロリン酸銅（II）、ピロリン酸ナトリウム、フェニルリン酸ナトリウム、メタリン酸、メタリン酸カリウム、メタリン酸ナトリウム、リン酸、リン酸亜鉛、リン酸アルミニウム、リン酸アルミニウムマグネシウム、リン酸一アンモニウム、リン酸一ナトリウム、リン酸カリウム、リン酸カルシウム、リン酸グアニジウム、リン酸クロム（III）、リン酸三アンモニウム、リン酸三カリウム、リン酸三ナトリウム、リン酸水素二アンモニウム、リン酸水素二アンモニウムナトリウム、リン酸水素カルシウム、リン酸水素二カリウム、リン酸水素二ナトリウム、リン酸水素バリウム等が使用可能である。
【００４８】
塩素イオン、硫酸イオン、酢酸イオンの供給源はこれを含む任意の化合物、例えば塩酸、硫酸、酢酸、金属の塩化物、金属の硫酸塩、金属の酢酸塩等が使用可能である。
また、上記水性液状組成物が、更に前述のアミン、アミド及びこれらの誘導体、尿素、チオ尿素及びこれらの誘導体、前述のカルボン酸、シリカ化合物、界面活性剤、Ｎａ、Ｋ、Ｃｕ、Ａｇから成る群より選択される少なくとも一種を含有すると更に良好な耐食性を得ることが可能になる。
【００４９】
この様に形成した亜鉛めっきとその上の保護皮膜に更に無機、有機若しくは無機有機複合コーティング皮膜又はこれらの多層コーティング皮膜を施すと、より一層耐食性が向上する。特にコーティング処理液中にシリカ化合物を０．１〜５０％含むもので処理したものの耐食性が良好である。
シリカ化合物の種類は任意のもので良く、例えば、各種コロイダルシリカ、各種ケイ酸ソーダ等が使用可能である。
【００５０】
以上のものはいずれも六価クロムを用いずに従来のクロメート皮膜と同等以上の耐食性を得るのに有効であるが、その中でも特に１〜８０ｇ／Ｌの亜鉛、１０〜３００ｇ／Ｌの水酸化アルカリ及び０．４〜４０ｇ／Ｌの脂肪族アミン又はそのポリマー、アルキレンオキサイド化合物、０．５〜４００ｇ／Ｌのカルボン酸化合物、０．０１〜５０ｇ／Ｌのポリビニルアルコールから成る群から選択される少なくとも一種を含有し、更に合金めっきの場合は合金成分として１ｍｇ／Ｌ〜１ｇ／Ｌの鉄、コバルト、１０ｍｇ／Ｌ〜３０ｇ／Ｌのニッケル、１０ｍｇ／Ｌ〜３０ｇ／Ｌのマンガン、１〜１００ｇ／Ｌのスズから成る群から選択される少なくとも一種を含有する亜鉛又は亜鉛合金めっき浴に導電性の基材を浸漬し、前記基材に所望の厚さのめっきを行い、しかる後にＡ）三価のクロムの供給源、Ｂ）酸化性物質の供給源、並びにＣ）リンの酸素酸、酸素酸塩又はこれらの無水物を含有する水溶性組成物又は三価クロムイオン並びに塩素イオン、フッ素イオン、硝酸イオン、硫酸イオン、及び酢酸イオンから成る群から選択される少なくとも一種を含有する水溶性組成物により前記めっき上に保護皮膜を形成するのが効果的である。また、更にこの保護皮膜上に無機、有機若しくは有機無機複合のコーティング皮膜又はこれらの多層コーティング皮膜を形成すると大幅に耐食性が向上する。コーティング処理液中にシリカ化合物を０．１〜５０％含むと尚一層耐食性が向上する。
【００５１】
すなわち、前述の特定の浴組成及び／又は特定の添加剤を含むめっき浴に導電性の基材を浸漬し、前記基材に所望の厚さの亜鉛又は亜鉛合金めっきを行い、しかる後に前述の特定の水性液状組成物により保護皮膜を形成すると、めっきの均一電着性の高さ、レベリング性、ツキマワリ性の良さにより、保護皮膜の均一な生成を促すことから、保護皮膜自体の耐食性能をフルに引き出すことが可能となり、六価クロムを使用しなくても従来のクロメート皮膜と同等以上の耐食性を得ることが可能となる。更にこの保護皮膜上にコーティング皮膜を形成することにより大幅に耐食性を向上させることが可能になる。
【００５２】
【実施例】
以下、実施例により本発明を説明する。試験片は適当な前処理（脱脂、脱スマットなど）を行った後、以下に示すそれぞれの処理を行った。
実施例１
亜鉛１２ｇ／Ｌ、水酸化ナトリウム１３０ｇ／Ｌ、グルコン酸ソーダ０．１ｇ／Ｌ、エチレンジアミンとエピクロルヒドリンの反応物を５％とイミダゾールとエピクロルヒドリンの反応物５％を含む水溶液４ｍＬ／Ｌが含まれためっき液で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を酢酸クロム（III）２５ｇ／Ｌ、７５％リン酸３０ｇ／Ｌを含み、アンモニアでｐＨを３に調整した液に３０秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は１６８時間であり、鉄素地の錆である赤錆発生時間は６２４時間であった。
【００５３】
実施例２
亜鉛１２ｇ／Ｌ、水酸化ナトリウム１３０ｇ／Ｌ、「ＭＩＲＡＰＯＬ１００」２．５ｇ／Ｌ、バニリン５０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を酢酸クロム（III）２５ｇ／Ｌ、７５％リン酸３０ｇ／Ｌを含み、アンモニアでｐＨを３に調整した液に３０秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は１６８時間であり、鉄素地の錆である赤錆発生時間は６００時間であった。
【００５４】
実施例３
亜鉛８ｇ／Ｌ、水酸化カリウム１３０ｇ／Ｌ、「ＭＩＲＡＰＯＬ１００」２．５ｇ／Ｌ、バニリン５０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を酢酸クロム（III）２５ｇ／Ｌ、７５％リン酸３０ｇ／Ｌを含み、アンモニアでｐＨを３に調整した液に３０秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は１９２時間であり、鉄素地の錆である赤錆発生時間は６４８時間であった。
【００５５】
実施例４
亜鉛８ｇ／Ｌ、水酸化ナトリウム１００ｇ／Ｌ、「ＭＩＲＡＰＯＬ５５０」２．５ｇ／Ｌ、バニリン４５ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硝酸クロム（III）１５ｇ／Ｌ、塩化コバルト１ｇ／Ｌ、次亜リン酸２０ｇ／Ｌ、６０％硝酸１８ｇ／Ｌを含み、アンモニアでｐＨを２．５に調整した液に４５秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地に達する傷をつけた後、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は２１６時間、（２）は６２４時間、（３）は２８８時間であり、鉄素地の錆である赤錆発生時間は（１）は７２０時間、（２）は１９２０時間、（３）１５１２時間であった。
【００５６】
実施例５
亜鉛８ｇ／Ｌ、水酸化ナトリウム１００ｇ／Ｌ、「ＭＩＲＡＰＯＬ５５０」２．５ｇ／Ｌ、バニリン４５ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硝酸クロム（III）１５ｇ／Ｌ、コロイダルシリカ（ＳＩ−５５０、触媒化成（株）製）５ｇ／Ｌ、次亜リン酸２０ｇ／Ｌ、６０％硝酸１８ｇ／Ｌを含み、アンモニアでｐＨを２．５に調整した液に４５秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地に達する傷をつけた後、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は２１６時間、（２）は６２４時間、（３）は２６４時間であり、鉄素地の錆である赤錆発生時間は（１）は６９６時間、（２）は１９２０時間、（３）は１４８８時間であった。
【００５７】
実施例６
亜鉛８ｇ／Ｌ、水酸化ナトリウム１００ｇ／Ｌ、「ＭＩＲＡＰＯＬ５５０」２．５ｇ／Ｌ、バニリン４５ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硝酸クロム（III）１５ｇ／Ｌ、、次亜リン酸２０ｇ／Ｌ、６０％硝酸１８ｇ／Ｌ、アデカカチオエースＰＤ−５０（旭電化（株）製）０．５ｇ／Ｌを含み、アンモニアでｐＨを２．５に調整した液に４５秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地に達する傷をつけた後、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は２１６時間、（２）は６００時間、（３）は２８８時間であり、鉄素地の錆である赤錆発生時間は（１）は６７２時間、（２）は１８９６時間、（３）は１５３６時間であった。
【００５８】
実施例７
亜鉛１２ｇ／Ｌ、水酸化ナトリウム１３０ｇ／Ｌ、三号ケイ酸ソーダ３０ｇ／Ｌ、「ＭＩＲＡＰＯＬ５５０」３ｇ／Ｌ、アニスアルデヒド３０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硝酸クロム（III）３０ｇ／Ｌ、７５％リン酸４０ｇ／Ｌを含み、水酸化ナトリウムでｐＨを１．５に調整した液に３０秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地に達する傷をつけた後、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は２１６時間、（２）は６２４時間、（３）は２４０時間であった。また、鉄素地の錆である赤錆発生時間は（１）は７２０時間、（２）は１９４４時間、（３）は１４６４時間であった。
【００５９】
実施例８
亜鉛１８ｇ／Ｌ、水酸化ナトリウム１５０ｇ／Ｌ、三号ケイ酸ソーダ１５０ｇ／Ｌ、構造式（８）のポリマー４ｇ／Ｌ、アニスアルデヒド５０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硫酸クロム（III）３５ｇ／Ｌ、７５％リン酸４５ｇ／Ｌを含み、アンモニアでｐＨを３に調整した液に６０秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は１９２時間であり、鉄素地の錆である赤錆発生時間は６９６時間であった。
【００６０】
実施例９
亜鉛１０ｇ／Ｌ、水酸化ナトリウム１２０ｇ／Ｌ、鉄０．０１ｇ／Ｌ、「ＭＩＲＡＰＯＬ ＷＴ」３ｇ／Ｌ、バニリン４０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硝酸クロム（III）１０ｇ／Ｌ、７５％リン酸２５ｇ／Ｌ、６０％硝酸２５ｇ／Ｌを含む水溶液をアンモニアでｐＨ２．０に調整した処理液に１５秒間浸漬したところ、全体に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、アクリル樹脂１０％、ブチルセルソルブ３％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、アクリル樹脂１０％、ブチルセルソルブ３％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地にまで達する傷をつけ、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は１６８時間、（２）は６４８時間、（３）は２４０時間であり、鉄素地の錆である赤錆発生時間は（１）は６００時間、（２）は１９９２時間、（３）は１３９２時間であった。
【００６１】
実施例１０
亜鉛７ｇ／Ｌ、水酸化カリウム１２０ｇ／Ｌ、鉄０．０１ｇ／Ｌ、「ＭＩＲＡＰＯＬ ＷＴ」３ｇ／Ｌ、バニリン４０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硝酸クロム（III）１０ｇ／Ｌ、７５％リン酸２５ｇ／Ｌ、６０％硝酸２５ｇ／Ｌを含む水溶液をアンモニアでｐＨ２．０に調整した処理液に１５秒間浸漬したところ、全体に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地に達する傷をつけた後、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は１６８時間、（２）は６７２時間、（３）は２１６時間であり、鉄素地の錆である赤錆発生時間は（１）は６２４時間、（２）は２０１６時間、（３）は１３９２時間であった。
【００６２】
実施例１１
めっき浴中の鉄の代わりにコバルトを０．０１ｇ／Ｌ含む以外は実施例１０と全く同様の処理を行ったところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、アクリル樹脂１０％、ブチルセルソルブ３％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、アクリル樹脂１０％、ブチルセルソルブ３％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地にまで達する傷をつけ、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は１６８時間、（２）は６９６時間、（３）は２６４時間であり、鉄素地の錆である赤錆発生時間は（１）は６００時間、（２）は２０６４時間、（３）は１４４０時間であった。
【００６３】
実施例１２
亜鉛７ｇ／Ｌ、水酸化ナトリウム９０ｇ／Ｌ、鉄０．０１ｇ／Ｌ、構造式（６）のポリマー４ｇ／Ｌ、エチルバニリン３０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片をモリブデン酸アンモン３ｇ／Ｌ、硝酸クロム（III）５ｇ／Ｌ、７５％リン酸１５ｇ／Ｌ、６０％硝酸５ｇ／Ｌを含む水溶液をアンモニアでｐＨ２．０に調整した処理液に１５秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は１９２時間であり、鉄素地の錆である赤錆発生時間は７２０時間であった。
【００６４】
実施例１３
めっき浴中の鉄の代わりにニッケルを０．０１ｇ／Ｌ含む以外は実施例１２と全く同様の処理を行ったところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、アクリル樹脂１０％、ブチルセルソルブ３％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、アクリル樹脂１０％、ブチルセルソルブ３％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地にまで達する傷をつけ、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は１９２時間、（２）は６９６時間、（３）は２１６時間であり、鉄素地の錆である赤錆発生時間は（１）は７２０時間、（２）は２０８８時間、（３）は１４４０時間であった。
【００６５】
実施例１４
亜鉛１０ｇ／Ｌ、水酸化ナトリウム１２０ｇ／Ｌ、三号ケイ酸ソーダ５０ｇ／Ｌ、鉄０．０４ｇ／Ｌ、「ＭＩＲＡＰＯＬ ＡＤ−１」４ｇ／Ｌ、ヘリオトロピン５０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硫酸クロム（III）１５ｇ／Ｌ、亜リン酸２０ｇ／Ｌ、６０％硝酸２５ｇ／Ｌを含む水溶液をアンモニアでｐＨ２．０に調整した処理液に６０秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地にまで達する傷をつけた後、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は２１６時間、（２）は６４８時間、（３）は２８８時間であり、鉄の錆である赤錆発生時間は（１）は７２０時間、（２）は２０６４時間、（３）は１５１２時間であった。
【００６６】
実施例１５
めっき浴中の鉄の代わりにコバルトを０．０６ｇ／Ｌ含む以外は実施例１４と全く同様の処理を行ったところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、アクリル樹脂１０％、ブチルセルソルブ３％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、アクリル樹脂１０％、ブチルセルソルブ３％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地にまで達する傷をつけた後、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は２１６時間、（２）は７２０時間、（３）は２６４時間であり、鉄素地の錆である赤錆発生時間は（１）は７２０時間、（２）は２０８８時間、（３）は１４６４時間であった。
【００６７】
実施例１６
亜鉛１５ｇ／Ｌ、水酸化ナトリウム１５０ｇ／Ｌ、三号ケイ酸ソーダ１５０ｇ／Ｌ、鉄０．１ｇ／Ｌ、「ＭＩＲＡＰＯＬ ＷＴ」４ｇ／Ｌ、アニスアルデヒド４０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硫酸（III）クロム２０ｇ／Ｌ、次亜リン酸２５ｇ／Ｌ、６０％硝酸１０ｇ／Ｌを含む水溶液をカ性ソーダでｐＨ２．５に調整した処理液に４５秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地にまで達する傷をつけた後、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は２４０時間、（２）は７４４時間、（３）は２４０時間であり、鉄素地の錆である赤錆発生時間は（１）は７４４時間、（２）は２１３６時間、（３）は１４８８時間であった。
【００６８】
実施例１７
亜鉛１５ｇ／Ｌ、水酸化ナトリウム１５０ｇ／Ｌ、三号ケイ酸ソーダ１５０ｇ／Ｌ、鉄０．１ｇ／Ｌ、「ＭＩＲＡＰＯＬ ＷＴ」４ｇ／Ｌ、アニスアルデヒド４０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硫酸クロム（III）２０ｇ／Ｌ、塩化コバルト１ｇ／Ｌ、次亜リン酸２５ｇ／Ｌ、６０％硝酸１０ｇ／Ｌ、を含む水溶液をカ性ソーダでｐＨ２．５に調整した処理液に４５秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地にまで達する傷をつけた後、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）はは３１２時間、（２）は８４０時間、（３）は２８８時間であり、鉄素地の錆である赤錆発生時間は（１）は８１６時間であり、（２）は２２５６時間、（３）は１５１２時間であった。
【００６９】
実施例１８
亜鉛１５ｇ／Ｌ、水酸化ナトリウム１５０ｇ／Ｌ、三号ケイ酸ソーダ１５０ｇ／Ｌ、鉄０．１ｇ／Ｌ、「ＭＩＲＡＰＯＬ ＷＴ」４ｇ／Ｌ、アニスアルデヒド４０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硫酸クロム（III）２０ｇ／Ｌ、次亜リン酸２５ｇ／Ｌ、６０％硝酸１０ｇ／Ｌ、コロイダルシリカ（ＳＩ−５５０、触媒化成（株）製）５ｇ／Ｌを含む水溶液をカ性ソーダでｐＨ２．５に調整した処理液に４５秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地にまで達する傷をつけた後、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は３１２時間、（２）は８４０時間、（３）は２８８時間であり、鉄素地の錆である赤錆発生時間は（１）は８４０時間、（２）は２２８０時間、（３）は１５１２時間であった。
【００７０】
実施例１９
亜鉛１５ｇ／Ｌ、水酸化ナトリウム１５０ｇ／Ｌ、三号ケイ酸ソーダ１５０ｇ／Ｌ、鉄０．１ｇ／Ｌ、「ＭＩＲＡＰＯＬ ＷＴ」４ｇ／Ｌ、アニスアルデヒド４０ｍｇ／Ｌが含まれためっき浴で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硫酸クロム（III）２０ｇ／Ｌ、次亜リン酸２５ｇ／Ｌ、６０％硝酸１０ｇ／Ｌ、アデカカチオエースＰＤ−５０（旭電化（株）製）０．５ｇ／Ｌを含む水溶液をカ性ソーダでｐＨ２．５に調整した処理液に４５秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、アクリル樹脂１０％、ブチルセルソルブ３％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、アクリル樹脂１０％、ブチルセルソルブ３％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地にまで達する傷をつけ、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は（１）は３１２時間、（２）は９６０時間、（３）は３１２時間であり、鉄素地の錆である赤錆発生時間は（１）は８１６時間であり、（２）は２４００時間、（３）は１５８４時間であった。
【００７１】
実施例２０
亜鉛８ｇ／Ｌ、カ性ソーダ１２０ｇ／Ｌ、グルコン酸ソーダ３５ｇ／Ｌ、鉄０．０６ｇ／Ｌ、コバルト０．０４ｇ／Ｌ、「ＭＩＲＡＰＯＬ １００」５ｇ／Ｌ、バニリン４０ｍｇ／Ｌが含まれためっき液で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硝酸クロム（III）１５ｇ／Ｌ、塩化コバルト１ｇ／Ｌ、次亜リン酸２０ｇ／Ｌ、６０％硝酸１８ｇ／Ｌを含み、アンモニアでｐＨを２．５に調整した液に４５秒間浸漬したところ、均一な干渉色を有する処理外観を得た。この試験片二枚にコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施した後、一枚はそのまま、もう一枚は試験片の対角線上にカッターナイフにて素地にまで達する傷をつけて塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ亜鉛の錆である白錆発生時間は前者は９８４時間、後者は３１２時間であり、鉄素地の錆である赤錆発生時間は前者は２５２０時間、後者は１５６０時間であった。
【００７２】
実施例２１
亜鉛２０ｇ／Ｌ、カ性ソーダ１５０ｇ／Ｌ、酒石酸５０ｇ／Ｌ、鉄０．４５ｇ／Ｌ、ジメチルアミンとエピクロルヒドリンの反応物１０％、Ｎ−メチルピペラジン１０％、イミダゾールとエピクロルヒドリンの反応物５％を含む水溶液８ｍＬ／Ｌ、ヘリオトロピン２％、バニリン１％を含む水溶液２ｍＬ／Ｌが含まれためっき液で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硫酸クロム（III）１０ｇ／Ｌ、７５％リン酸３０ｇ／Ｌ、６７．５％硝酸５ｇ／Ｌを含み、アンモニア水でｐＨを１．５に調整した処理液に９０秒間浸漬したところ、均一な黒色を有する処理外観を得た。この試験片を二枚作製し、一枚はそのまま、もう一枚はコロイダルシリカ２０％、アクリル樹脂１０％、ブチルセルソルブ３％を含むコーティング液にてコーティングを施した後、塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ亜鉛の錆である白錆発生時間は前者は３１２時間、後者は１１２８時間であり、鉄素地の錆である赤錆は前者は７２０時間、後者は３５０４時間であった。
【００７３】
実施例２２
亜鉛１７ｇ／Ｌ、カ性ソーダ１４０ｇ／Ｌ、トリエタノールアミン３５ｇ／Ｌ、鉄０．４ｇ／Ｌ、「ＭＩＲＡＰＯＬ １００」５ｇ／Ｌ、バニリン４０ｍｇ／Ｌが含まれためっき液で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を硝酸クロム（III）１５ｇ／Ｌ、塩化コバルト１ｇ／Ｌ、次亜リン酸２０ｇ／Ｌ、６０％硝酸１８ｇ／Ｌを含み、アンモニアでｐＨを２．５に調整した液に４５秒間浸漬したところ、均一な黒色を有する処理外観を得た。この試験片を三枚作製し、（１）一枚はそのまま、（２）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施し、（３）一枚はコロイダルシリカ２０％、カ性ソーダ１％を含むコーティング液にてコーティングを施した後、試験片の対角線上にカッターナイフにて鉄素地に達する傷をつけた上で、それぞれを塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は、（１）は２８８時間、（２）は１００８時間、（３）は２８８時間であり、鉄素地の錆である赤錆発生時間は（１）は６７２時間、（２）は３２６４時間、（３）は１４８８時間であった。
【００７４】
実施例２３
亜鉛２０ｇ／Ｌ、塩化アンモニウム１８０ｇ／Ｌ、β−ナフトールエチレンオキサイド付加物２０％、エチレンジアミンプロピオンオキサイド付加物１０％、ベンザルアセトン０．５％を含む水溶液２５ｍＬ／Ｌが含まれためっき液で試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）にめっきを行った。２Ａ／ｄｍ²で電解し、膜厚８μｍのめっきを施した試験片を酢酸クロム（III）２５ｇ／Ｌ、７５％リン酸３０ｇ／Ｌを含み、アンモニアでｐＨを３に調整した液に３０秒間浸漬したところ、全面に均一な干渉色を有する、光沢のある処理外観を得た。この試験片を塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、亜鉛の錆である白錆発生時間は１４４時間であり、鉄素地の錆である赤錆発生時間は５７６時間であった。
【００７５】
実施例２４
亜鉛１５ｇ／Ｌ、水酸化ナトリウム１５０ｇ／Ｌ、三号ケイ酸ソーダ１５０ｇ／Ｌ、鉄０．０３ｇ／Ｌ、ニッケル０．０２ｇ／Ｌ、「ＭＩＲＡＰＯＬ ＷＴ」４ｇ／Ｌ、アニスアルデヒド４０ｍｇ／Ｌが含まれためっき浴でハルセル試験を行った。２Ａで１５分間電解した試験片を硫酸クロム（III）２０ｇ／Ｌ、次亜リン酸２５ｇ／Ｌ、６０％硝酸１０ｇ／Ｌを含む水溶液をカ性ソーダでｐＨ２．５に調整した処理液に４５秒間浸漬したところ、高電流密度部から低電流密度部まで均一な干渉色を有する、光沢のある処理外観を得た。この試験片の０．１、０．５、１、２、３、５、１０Ａ／ｄｍ² 相当部分の膜厚を測定したところ、表１の本発明の欄の分布を得た。
【００７６】
【表１】

【００７７】
尚、ハルセル試験とは陽極に対して陰極を斜めに配置し電解を行うことにより、陰極上に電流密度の勾配を発生させる試験方法であり、これにより電流密度とめっきの質（めっき外観や膜厚等）の関係を知ることができるものである。
【００７８】
比較例１
膜厚５０μｍの溶融亜鉛めっきを施した試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）を酢酸クロム（III）２５ｇ／Ｌ、７５％リン酸３０ｇ／Ｌを含み、アンモニアでｐＨを３に調整した液に３０秒間浸漬したところ、干渉色が薄く、光沢の少ない処理外観を得た。この試験片を二枚作製し、一枚はそのまま、もう一枚は試験片の対角線上にカッターナイフにて鉄素地に達する傷を付けた上で塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ亜鉛の錆である白錆発生時間は前者は４８時間、後者は２４時間であり、鉄素地の錆である赤錆発生時間は前者は４３２時間、後者は３１２時間であった。
【００７９】
比較例２
膜厚５０μｍの溶融亜鉛めっきを施した試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）を、硝酸クロム（III）１５ｇ／Ｌ、次亜リン酸２０ｇ／Ｌ、６０％硝酸１８ｇ／Ｌを含み、アンモニアでｐＨを２．５に調整した液に４５秒間浸漬したところ、干渉色が薄く光沢の少ない処理外観を得た。この試験片を二枚作製し、一枚はそのまま、もう一枚は試験片の対角線上にカッターナイフにて鉄素地に達する傷を付けた上で塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ亜鉛の錆である白錆発生時間は前者は４８時間、後者は２４時間であり、鉄素地の錆である赤錆発生時間は前者は４８０時間、後者は２８８時間であった。
【００８０】
比較例３
膜厚５０μｍの溶融亜鉛めっきを施した試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）を、硫酸クロム（III）３５ｇ／Ｌ、７５％リン酸４５ｇ／Ｌを含み、アンモニアでｐＨを３に調整した液に６０秒間浸漬したところ、干渉色が薄く、光沢の少ない処理外観を得た。この試験片を二枚作製し、一枚はそのまま、もう一枚は試験片の対角線上にカッターナイフにて鉄素地に達する傷を付けた上で塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ亜鉛の錆である白錆発生時間は前者は４８時間、後者は２４時間であり、鉄素地の錆である赤錆発生時間は前者は４８０時間、後者は３１２時間であった。
【００８１】
比較例４
５０μｍの溶融亜鉛めっきを施した試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）を、有色クロメート処理液（クロム酸（VI）３ｇ／Ｌ、硝酸１ｇ／Ｌ、硫酸０．３ｇ／Ｌを含む）に１５秒間浸漬したところ、干渉色と光沢のある処理外観を得た。この試験片を二枚作製し、一枚はそのまま、もう一枚は試験片の対角線上にカッターナイフにて鉄素地に達する傷を付けた上で塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ亜鉛の錆である白錆発生時間は前者は９６時間、後者は４８時間であり、鉄素地の錆である赤錆発生時間は前者は６００時間、後者は３３６時間であった。
【００８２】
比較例５
膜厚５０μｍの合金化溶融亜鉛めっきを施した試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）をモリブデン酸アンモン３ｇ／Ｌ、硝酸クロム（III）５ｇ／Ｌ、７５％リン酸１５ｇ／Ｌ、６０％硝酸５ｇ／Ｌを含む水溶液をアンモニアでｐＨ２．０に調整した処理液に１５秒間浸漬したところ、干渉色が無く、光沢の少ない処理外観を得た。この試験片を二枚作製し、一枚はそのまま、もう一枚は試験片の対角線上にカッターナイフにて鉄素地に達する傷を付けた上で塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ亜鉛の錆である白錆発生時間は前者は４８時間後者は２４時間であり、鉄素地の錆である赤錆発生時間は前者は５０４時間、後者は２４０時間であった。
【００８３】
比較例６
膜厚５０μｍの合金化溶融亜鉛めっきを施した試験片（ＳＰＣＣ、５０×１００ｍｍ、厚さ１ｍｍ）を有色クロメート処理液（クロム酸（VI）３ｇ／Ｌ、硝酸１ｇ／Ｌ、硫酸０．３ｇ／Ｌを含む）に１５秒間浸漬したところ、干渉色はあるが、光沢の少ない処理外観を得た。この試験片を二枚作製し、一枚はそのまま、もう一枚は試験片の対角線上にカッターナイフにて鉄素地に達する傷を付けた上で塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ亜鉛の錆である白錆発生時間は前者は１４４時間、後者は７２時間であり、鉄素地の錆である赤錆発生時間は前者は５７６時間、後者は３３６時間であった。
【００８４】
比較例７
ほうふっ化亜鉛を３００ｇ／Ｌ、ほうふっ化アンモニウムを３５ｇ／Ｌ、添加剤として甘草１ｇ／Ｌを含むめっき液を用いハルセル試験を行った。２Ａで１５分間電解した試験片を硫酸クロム２０ｇ／Ｌ、次亜リン酸２５ｇ／Ｌ、６０％硝酸１０ｇ／Ｌを含む水溶液をカ性ソーダでｐＨ２．５に調整した処理液に４５秒間浸漬したところ、高電部から中電部にかけては無光沢でやや干渉色のある処理外観を得たが低電部にはめっきが析出せずに、鉄素地がむき出しになった。この試験片を塩水噴霧試験（ＪＩＳ Ｚ ２３７１）に投入したところ、高電部から中電部までのめっきが析出した部分の白錆発生時間は２４時間であった。また、低電部のめっきが析出しなかった部分は投入直後に鉄の錆である赤錆が発生した。また、０．１、０．５、１、２、３、５、１０Ａ／ｄｍ² 相当部分の膜厚を測定したところ、表１の比較例７の欄の分布を得た。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for forming a protective film on a zinc or zinc alloy plating after the metal or zinc alloy plating. In particular, the properties of the treated product are improved by the synergistic effect of forming the galvanizing and the protective film.
[0002]
[Prior art]
Since sacrificial corrosion protection of iron-based materials with zinc is the most effective and economical, many iron-based materials are coated with zinc or zinc alloys and are used in a wide range of fields such as building materials, automobiles, and home appliances. 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. It can be roughly classified into electrogalvanizing which deposits by electrolysis and forms a plating film. Furthermore, electrogalvanizing 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. Sacrificial corrosion protection with zinc suppresses dissolution of iron by forming a battery under the condition where zinc and iron are in contact with each other, and zinc as a base metal is dissolved as an anode. Therefore, since the sacrificial anticorrosive effect ends at the same time as the disappearance of zinc, it is necessary to suppress dissolution of the zinc layer in order to maintain the effect. If the dissolution of the zinc layer is not suppressed, white rust, which is zinc rust, will immediately occur in the galvanized iron-based materials and parts.
[0003]
Zinc alloy plating is a method in which zinc and other metals are alloyed and plated to change the properties of the zinc layer and suppress dissolution, which is described in JP-B-63-19600, JP-B-3-38351, Many baths and methods are disclosed, such as Sho 62-238387, Sho 62-287092, JP 1-219188, JP 1-298192, JP 2-118944, JP 2-282493, JP 5-1112889, etc. Has been. Thereby, the rust prevention power (bare corrosion resistance) in the case of not protecting the zinc layer is improved as compared with normal galvanizing. However, in order to obtain a practically sufficient rust-proofing power even with zinc alloy plating, it is actually necessary to use a protective treatment such as chromate treatment in combination.
[0004]
There are three types of protection methods for zinc layers that are usually applied to zinc and zinc alloy plating: phosphate film treatment and chromate film treatment. There are three types of chromate film treatment: electrolytic chromate treatment, coating chromate treatment, and reactive chromate treatment. being classified. The chromate treatment is applied not only to zinc but also to aluminum, cadmium, magnesium and the like.
As disclosed in JP-A-3-107469, phosphating is carried out by using zinc ions and phosphate ions as film-forming components heated to 40 to 50 ° C. or around 75 ° C., and fluorine as an etching agent or film densifying agent. This is a treatment in which ions or complex fluoride ions are immersed in a treatment solution containing essential components to form a film, washed with water and then dried. The surface state of the film obtained by this method is an uneven surface formed so that the needle-shaped crystals of zinc phosphate are folded, and this surface state improves the adhesion of the coating, which is the purpose of this film, or Contributes to improved corrosion resistance after painting. However, this film has a remarkable lack of anti-corrosion power (corrosion resistance) when unpainted, and the processed appearance is matte gray to grayish white with poor decorativeness. There is a disadvantage that is not suitable for partially coated products and products that are not painted. In this state, the phosphate film has poor adhesion to the paint, and defects such as blistering occur and corrosion resistance is insufficient.Therefore, post-treatment called sealing after chemical conversion must be performed, but the main component of this post-treatment agent is chromium. It is an acid (hexavalent chromium), and the phosphate film cannot escape from the problem of adverse effects of hexavalent chromium on the human body and the environment, which has been a problem in recent years. In addition, since the phosphate film does not form a film unless it contains fluorine ions or complex fluoride ions, these substances are essential components. However, these substances are highly corrosive and are emission control substances. Further, the processing temperature is high, and there is a disadvantage that the equipment for heating and the cost are high.
[0005]
On the other hand, the chromate film has better corrosion resistance than the phosphate film even though it is unpainted, but the chromate treatment uses harmful hexavalent chromium. In recent years, it has become a major problem because of its negative impact on the environment. This is a problem that cannot be solved as long as the chromate film is a film that exhibits corrosion resistance due to hexavalent chromium in the film. Another problem is that the electrolytic chromate treatment produces a chromate film by electrolysis, so there is always a problem of thickening, making it difficult to form a uniform film, and there may be variations in quality (performance) due to current density. There is sex. Chromium mist generated during electrolysis can be a more serious pollution problem than other methods. The coating-type chromate treatment is a method in which an acidic aqueous solution containing chromic acid as a main component is applied to a metal surface and then dried by heating without washing with water. Since it is a coating type, it is not suitable for a complicated shape like electrolytic chromate, and there is no problem in application to a steel sheet or the like although it is restricted by the object to perform coating with a uniform thickness. In contrast, reactive chromate has excellent appearance uniformity and applicability to products with complex shapes, provides stable corrosion resistance, and is often used alone as well as the paint base. Leaving chrome pollution problems.
[0006]
Under such circumstances, in recent years, many antirust coatings that do not use hexavalent chromium have been proposed. Japanese Patent Laid-Open No. 7-504942 discloses a method for improving corrosion resistance by forming a thin film on a metal surface by treating with an aqueous solution containing a molybdate and a compound capable of forming a heteropolymolybdate with the molybdate. It is disclosed. Japanese Patent Laid-Open No. 9-95779 discloses vanadate and / or a vanadium salt of an inorganic acid and an organic acid having a reducing power, and cathodic electrolysis in a treatment solution having a pH of 7 or more. JP-A-9-53192 discloses (A) an oxidizing substance, (B) a silicate and / or silicon dioxide, and (C) Ti, Zr, Ce, Sr, V, W, Mo. A method for obtaining a rust-preventing film on a metal substrate by using a liquid rust-preventing film composition containing at least one metal ion selected from the group consisting of the metal cations, oxymetal anions and fluorometal anions is disclosed. However, although these rust preventive coatings have improved pollution problems in that they do not use hexavalent chromium, the actual corrosion resistance is very low compared to the conventional chromate coating using hexavalent chromium, It has not reached the level that can be practically used as an industrial product.
[0007]
[Problems to be solved by the invention]
One of the evaluations of the rust-preventing power of galvanizing is the white rust (zinc rust) generation time and the red rust (iron base rust) generation time in the salt spray test (JIS Z 2371). The white rust generation time can evaluate the ability to maintain a good appearance, but even if white rust occurs, the iron base does not proceed with corrosion, so the original function of galvanizing to protect iron from corrosion Cannot be evaluated. When the corrosion of zinc proceeds and the corrosion reaches the iron base, red rust is generated. That is, the antirust ability with respect to iron of plating can be evaluated by red rust generation time. Currently, it is required to maintain a beautiful appearance and good corrosion resistance, so it is desirable that both white rust and red rust generation times be as long as possible. The conventional chromate film using hexavalent chromium on galvanizing has very high performance in this respect. However, when protection treatment not containing hexavalent chromium is performed on zinc or zinc alloy plating other than the present invention, a certain degree of rust prevention power can be obtained, but both white rust generation time and red rust generation time are on zinc plating. Compared with a chromate film using hexavalent chromium, the industrial product has not reached a level that can withstand practical use. Although it is possible to lengthen the red rust generation time by increasing the plating film thickness, in order to obtain the same performance as the chromate film on the conventional galvanizing, it is 4 to 5 times that of the conventional one, and in some cases 10 More than double the plating film thickness is required. This is not applicable to parts that require dimensional accuracy, has poor productivity, increases costs, consumes significant energy, and wastes zinc resources.
[0008]
The object of the present invention is to reduce the productivity and increase the cost by nearly 10 times due to the synergistic effect of applying a specific galvanizing and zinc alloy plating and a specific anti-corrosive film without using hexavalent chromium. Without using it, without using highly toxic hexavalent chromium, effectively using zinc resources, having a wide range of applications as industrial products, and with a level of surface treatment that can withstand practical use without reducing productivity It is to provide a metal surface treatment system to be produced.
[0009]
[Means for Solving the Problems]
As a result of diligent research by the present inventors, problems caused by the prior art include zinc, conductive salts and silicon compounds, aliphatic amines or polymers thereof, alkylene oxide addition compounds, carboxylic acid compounds, polyvinyl alcohol, polyvinyl alcohol derivatives, monosaccharides, polysaccharides. Contains at least one selected from the group consisting of sugars, amino acids, amino acid salts, acid amides, acid amide derivatives, aliphatic alcohols, amino alcohols, amino alcohol polymers, surfactants, ammonia and boric acid, and further for alloy plating In this case, the electroconductive substrate is immersed in a zinc or zinc alloy plating bath containing at least one selected from the group consisting of iron, cobalt, nickel, trivalent chromium, copper, manganese, aluminum, and tin. By performing the plating of the desired thickness on the substrate, Selected from the group consisting of Li, Mo, W, V, Nb, Ta, Ti, Zr, Ce, Sr, Fe, Ni, Al, Si, Co, Be, Mg, Ca, Ba and trivalent chromium. It has been found that this problem can be solved by forming a protective film on zinc or zinc alloy plating with an aqueous liquid composition containing at least one of the above. Further, it has been found that further improvement in corrosion resistance can be obtained by applying an organic, inorganic or organic-inorganic composite coating or a multilayer coating film thereof on the protective film.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the preferred silicon compound based on the results of the effects include colloidal silica, a powder that becomes colloidal silica when dispersed in water, as described in JP-A-8-209393, silicate (general formula mMOx / NSiO₂: M is a metal, m, n is a natural number, x is 1 or 2), and most silicon compounds such as No. 3 sodium silicate can be used.
[0011]
Examples of aliphatic amines are monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, diaminobutane, tetramethyldiaminobutane, diaminopropane, monomethylamine, dimethylamine, trimethylamine, diethylenetriamine, tetramethylpropylenediamine, dimethylpropylenediamine, trimethylamine. -N-butylamine, dimethylaminopropylamine, isopropanolamine, diisopropanolamine, triisopropanolamine, monoethylamine, diethylamine, triethylamine, hexamethylenetetramine, pentaethylenehexamine, imidazole, methylimidazole, dimethylimidazole, pyridine, aminopyridine, amino Ethylpyridine, piperazine, aminopipera Emissions, aminoethylpiperazine, morpholine, aminopropyl morpholine, piperidine, mono- methylpiperidine, aminoethyl piperidine, urea, pyrrolidine, thiourea and derivatives thereof can be used.
[0012]
Examples of the aliphatic amine polymer include a reaction product of the aliphatic amine and epichlorohydrin, polyethyleneimine, polyamine sulfone, polyallylamine, structural formula (1)
[0013]
[Chemical 1]

[0014]
(Wherein R1 and R2 each represent hydrogen, methyl, ethyl, butyl or isobutyl, and R3 represents CH₂, C₂H_FourOr C_ThreeH₆A polymer represented by the structural formula (2)
[0015]
[Chemical 2]

[0016]
(Wherein R 1 and R 2 are hydrogen, methyl, ethyl, isopropyl, butyl, —CH₂CH₂(OCH₂CH₂) XOH (X is 0-5) or -CH₂CH₂(OCCH₂CH₂) XOH (X represents 0 to 5)), structural formula (3)
[0017]
[Chemical Formula 3]

[0018]
Wherein R1, R2, R3 and R4 are hydrogen, methyl, ethyl, isopropyl, 2-hydroxyethyl-CH, respectively.₂CH₂(OCH₂CH₂)_XOH (X is 0-6) or 2-hydroxyethyl-CH₂CH₂(OCCH₂CH₂)_XOH (X is 0-6), R5 is (CH₂)₂-O- (CH₂)₂, (CH₂)₂-O- (CH₂)₂-O- (CH₂)₂Or CH₂-CHOH-CH₂-O-CH₂-CHOH-CH₂Wherein n is 1 or more and Y is S or O), a structural formula (4)
[0019]
[Formula 4]

[0020]
(Wherein R1, R2, R3 and R4 are each hydrogen, methyl, ethyl, isopropyl, 2-hydroxylethyl-CH₂CH₂(OCH₂CH₂)_XOH (X is 0-6) or 2-hydroxylethyl-CH₂CH₂(OCCH₂CH₂)_XOH (X is 0-6), R5 is (CH₂)₂-O- (CH₂)₂, (CH₂)₂-O- (CH₂) -O- (CH₂)₂Or CH₂-CHOH-CH₂-O-CH₂-CHOH-CH₂Wherein n is 1 or more and Y is S or O), a structural formula (5)
[0021]
[Chemical formula 5]

[0022]
Wherein R1 and R2 are each hydrogen, methyl, ethyl, isopropyl, butyl, —CH₂CH₂(OCH₂CH₂)_XOH (X is 0 to 5) or -CH₂CH₂(OCCH₂CH₂)_XOH (X is 0 to 5), n is 1 or more, Y is O or S), monomer, structural formula (6)
[0023]
[Chemical 6]

[0024]
(Wherein R1 and R2 each represent hydrogen or an alkyl group having 10 or less carbon atoms), structural formula (7)
[0025]
[Chemical 7]

[0026]
Wherein R1, R2, R3 and R4 each represent hydrogen or an alkyl group having 5 or less carbon atoms, X represents an inorganic anion, and Y represents S or O, and a structure Formula (8)
[0027]
[Chemical 8]

[0028]
(Wherein R1, R2, R3 and R4 each represent hydrogen or an alkyl group having 5 or less carbon atoms, X represents an inorganic anion, and Y represents S or O). Is possible. As an example of the polymer of the structural formula (1), “Adekathioace (trademark) PD-50” commercially available from Asahi Denka Kogyo Co., Ltd., and as an example of the polymer of the structural formula (2), Rhone-Poulenc "MIRAPOL (TM) 100" commercially available from: "MIRAPOL (TM) WT" as an example of the polymer of the structural formula (3), and "MIRAPOL (TM)" as an example of the polymer of the structural formula (4) Examples of the polymer of “AD-1” and the structural formula (5) include “MIRAPOL ™ 550”. The total amount of these polymers in the plating bath is preferably 1 to 50 g / L.
[0029]
Examples of alkylene oxide addition compounds include β-naphthol ethylene oxide adducts, bisphenol ethylene oxide adducts, bisphenol propylene oxide adducts, ethylenediamine ethylene oxide adducts, ethylenediamine propylene oxide adducts, polyoxyethylene alkylamines, polyoxyethylenes. Amine ester, propylene oxide ethylene oxide block polymer, polyoxyethylene sorbitan ester, stearic acid ethylene oxide adduct, stearic acid propylene oxide adduct, lauric acid ethylene oxide adduct, oleic acid ethylene oxide adduct, oleic acid propylene oxide adduct , Polyoxyethylene oleyl ether, polyoxyethylene lauryl ether Ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene tridecyl ether, polyoxyethylene dodecyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether and the like can be used.
[0030]
Examples of carboxylic acid compounds include gluconic acid, tartaric acid, ethylenediaminetetraacetic acid, propionic acid, aspartic acid, butyric acid, acetic acid, benzoic acid, alginic acid, ascorbic acid, nicotinic acid, quinolinic acid, salicylic acid, oxalic acid, sorbic acid, heptonic acid Veratric acid, acrylic acid, lactic acid, gallic acid, glutaric acid, glutamic acid, citric acid, and / or salts and derivatives thereof can be used.
As examples of polyvinyl alcohol and polyvinyl alcohol derivatives, commercially available polyvinyl alcohols such as Poval 205 (manufactured by Kuraray Co., Ltd.) and oxides and derivatives thereof can be used.
[0031]
Examples of monosaccharides include glucose, fructose, mannose, galactose, tagatose, sorbose, xylose, arabinose, ribulose, xylulose, lyxose, ribose, deoxyribose and the like.
Examples of polysaccharides include starch, cellulose, glycogen, caronin, laminaran, dexrolan, inulin, levan, elephant palm mannan, xylan, pectic acid, guaran, konjac mannan, heparin, chondroitin sulfate, hyaluronic acid, meskit gum, gatch gum, Arabic gum etc. can be used.
Examples of amino acids and amino acid salts include glucosamine, galactosamine, alanine, serine, aminobutyric acid, threonine, valine, norvanine, leucine, isoleucine, citrulline, phenylalanine, tyrosine, diiodotyrosine, dioxyphenylalanine, dibromotyrosine, proline, oxy Proline, tryptophan, cysteine, cystine, methionine, arginine, lysine, oxylysine, ornithine, canavamin, histidine, sodium salts and potassium salts thereof can be used.
[0032]
Examples of acid amides and acid amide derivatives include gluconic acid amide, tartaric acid amide, propionic acid amide, aspartic acid amide, butyric acid amide, acetic acid amide, benzoic acid amide, alginic acid amide, ascorbic acid amide, nicotinic acid amide, quinolinic acid amide, Salicylic acid amide, oxalic acid amide, sorbic acid amide, heptonic acid amide, veratric acid amide, acrylic acid amide, lactic acid amide, gallic acid amide, glutaric acid amide, glutamic acid amide, citric acid amide and derivatives thereof can be used .
[0033]
Examples of aliphatic alcohols are methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, methylene diol, ethylene diol, propylene diol, butylene diol, pentane diol, hexane diol, Heptanediol, octanediol, nonanediol, decanediol, undecanediol, dodecanediol, and the like can be used.
As examples of amino alcohol and amino alcohol polymer, aminoethyl ethanolamine, aminopropyl alcohol, etc., and a reaction product of these with epihalohydrin can be used.
[0034]
Examples of surfactants include dioctylsulfosuccinic acid and salts thereof, alkylphenol ether sulfate and salts thereof, dodecylbenzenesulfonic acid and salts thereof, alkylphenoxypolyoxyalkyleneethylsulfonic acid and salts thereof, polyoxyalkyleneethylsulfonic acid of higher alcohols And anionic surfactants such as salts thereof, and cationic surfactants such as N, N, N-trialkylammonium chloride, N, N-dialkylammonium chloride and N-monoalkylammonium chloride can be used. is there.
[0035]
As the conductive salt, sodium hydroxide, potassium hydroxide, ammonium chloride, potassium chloride or the like can be used.
As the aldehyde, vanillin, benzaldehyde, ethyl vanillin, veratraldehyde, anisaldehyde, o-chlorobenzaldehyde, p-chlorobenzaldehyde, heliotropin gives relatively good gloss, 0.001 to 50 g / L, Preferably, a good plating film is provided by a plating solution present at 10 to 5000 mg / L.
[0036]
In the case of alloy plating, at least one selected from the group consisting of iron, cobalt, nickel, trivalent chromium, copper, manganese, aluminum, and tin is included, particularly iron, cobalt 1 mg / L to 1 g / L, Nickel 10 mg / L to 30 g / L, manganese 10 mg / L to 30 g / L, tin 1 to 100 g / L, trivalent chromium, copper, aluminum 1 mg / L to 10 g / L at least one kind is included. Is appropriate.
[0037]
Each amount differs depending on whether it is zinc plating or zinc alloy plating. In zinc alloy plating, since the appropriate eutectoid ratio varies depending on the alloy components, the amount of each component is different and cannot be determined unconditionally. For example, in the case of zinc plating, zinc is 5 to 20 g / L, sodium hydroxide 90 to 150 g / L in an alkaline bath, zinc 10 to 40 g / L in an acidic bath, ammonium chloride, potassium chloride, or both in combination. In general, a range of 100 to 250 g / L is a range in which a good film can be obtained. Further, in the case of zinc-iron alloy plating, zinc 6 to 20 g / L, iron 1 mg / L to 1 g / L, and sodium hydroxide 85 to 150 g / L are general ranges for obtaining a uniform film. In any case, it is not possible to make a general decision because it is affected by conditions such as current density and bath temperature. There are no restrictions on the method of supplying the alloy components. Iron sulfate, iron chloride, cobalt sulfate, cobalt chloride, nickel sulfate, nickel chloride, nickel carbonate, manganese sulfate, manganese chloride, sodium stannate, potassium stannate, tin sulfate, chromium sulfate , Chromium chloride, chromium nitrate, copper sulfate, copper chloride, copper carbonate, aluminum chloride, aluminum nitrate and the like.
[0038]
The function of each component in the plating solution is as follows. Zinc and alloy components act as deposited metals, and the conductive salt contributes conductivity to the plating solution during electrolysis. Silicon compound, aliphatic amine or polymer thereof, alkylene oxide addition compound, carboxylic acid compound, polyvinyl alcohol, polyvinyl alcohol derivative, monosaccharide, polysaccharide, amino acid, amino acid salt, acid amide, acid amide derivative, aliphatic alcohol, amino Addition of alcohol, amino alcohol polymer, surfactant, ammonia, boric acid improves the basic required characteristics of zinc plating such as uniform gloss, leveling, uniform electrodeposition, and thickening properties in the plating appearance, and bath It suppresses the influence of impure metals inside. Further, in the case of alloy plating, the added metal is stabilized in the bath, and precipitation at a uniform ratio is possible.
[0039]
In addition, the conventional plating bath is weak against the temperature, and when the bath temperature exceeds 30 ° C., the uniform electrodeposition is poor and the plating appearance becomes dull, but the present invention is sufficiently practical even under plating conditions exceeding 30 ° C. It can withstand
[0040]
In addition to these, the present invention also improves other properties of conventional galvanizing. For example, the thickening property tends to be overlooked because it is not directly noticeable compared to the gloss of the appearance, etc., but is an important performance that cannot be ignored when evaluating galvanizing. Thickness is the ability to obtain effective plating even in a lower current density range.
In recent years, it has been considered that chromate-treated hexavalent chromium has an adverse effect on human health and the environment, and many chemical conversion films that do not contain hexavalent chromium have been proposed. Since most of them are inferior to the chromate treatment, the requirement for the ability to electrodeposit plating to a lower current density is becoming stronger every day to maintain total corrosion resistance. The present invention fully satisfies this requirement. In the present invention, the conventional galvanizing is greatly improved not only in this ability but also in characteristics such as pit prevention and leveling. Further, among these baths, in particular, the conductive salt contains alkali hydroxide, 0.4 to 40 g / L aliphatic amine or polymer thereof, alkylene oxide compound, 0.5 to 400 g / L carboxylic acid compound. And at least one selected from the group consisting of 0.01 to 50 g / L of polyvinyl alcohol, and in the case of alloy plating, 1 mg / L to 1 g / L of iron, cobalt, 10 mg / L to 30 g / L as alloy components By using a zinc or zinc alloy plating bath containing at least one selected from the group consisting of nickel of L, 10 mg / L to 30 g / L of manganese, and 1 to 100 g / L of tin, each of the above-mentioned best characteristics can be obtained. It becomes possible to obtain.
[0041]
On this modified zinc plating, Li, Mo, W, V, Nb, Ta, Ti, Zr, Ce, Sr, Fe, Ni, Al, Si, Co, Be, Mg, Ca, Ba and trivalent are further added. When the protective film is formed with an aqueous liquid composition containing at least one metal selected from the group consisting of chromium, the corrosion resistance is greatly improved as compared with the case where the protective film is formed on a zinc plating other than the present invention. Among these water-soluble compositions, A) a source of trivalent chromium, B) a source of oxidizable substance, C) a phosphorus oxyacid, an oxyacid salt or an anhydride thereof, or a trivalent It is particularly effective to form a protective film with chromium ions and those containing at least one selected from the group consisting of chlorine ions, fluorine ions, nitrate ions, sulfate ions and acetate ions.
[0042]
In forming this protective film, a process such as activation treatment or flash plating can be added between the plating process and the protective film forming process according to the application. Activation treatment promotes the formation of a protective film, and in order to improve the adhesion to the plating, plating is immersed in thin nitric acid, hydrochloric acid, sulfuric acid, hydrogen peroxide, etc. before the protective film formation process The activation of the surface means flash activation. Flash plating is a method that promotes the formation of a protective film by applying plating with a composition that easily forms a protective film after a normal plating process, and also provides adhesion to the plating. Is a processing method for improving the above.
[0043]
The aqueous liquid composition contains trivalent chromium ions 0.01 to 100 g / L, nitrate ions and / or fluorine ions 0.01 to 100 g / L and phosphorus oxyacid ions 0.1 to 200 g / L, and has a pH of 0. 5 to 4, selected from the group consisting of a bath temperature adjusted to 5 to 50 ° C., trivalent chromium ions 0.01 to 150 g / L, and chlorine ions, fluorine ions, nitrate ions, sulfate ions and acetate ions. Including 0.01 to 100 g / L, pH adjusted to 0.5 to 4, bath temperature adjusted to 5 to 60 ° C., trivalent chromium, Mo, Ti, Al, Si, Fe, Ni, One or more kinds selected from Mg, Ca, and Co, 0.01 to 100 g / L, one or more kinds selected from nitrate ion, sulfate ion, fluorine ion, and phosphate ion, and 0.1 to 200 g / L, and pH is adjusted to 0.1. 5-4, With that adjusting the temperature to 80 ° C. from 5, to obtain particularly good corrosion resistance.
[0044]
Sources of Li, Mo, W, V, Nb, Ta, Ti, Zr, Ce, Sr, Fe, Ni, Al, Si, Co, Be, Mg, Ca, Ba and trivalent chromium include these Any compound can be used. For example, lithium hydroxide, lithium chloride, molybdate, ammonium molybdate, sodium molybdate, calcium molybdate, molybdenum chloride, ammonium thiomolybdate, tungsten chloride, silicotungstic acid, tungstic acid, ammonium tungstate, calcium tungstate, Sodium tungstate, phosphotungstic acid, ammonium phosphotungstate, sodium phosphotungstate, vanadium oxide, vanadic acid, ammonium vanadate, sodium vanadate, ammonium metavanadate, sodium metavanadate, niobium chloride, ammonium hexafluoroniobate, chloride Tantalum, tantalum methylate, titanium chloride, titanium sulfate, zirconium chloride, zirconium sulfate, chloric acid Zirconium, cerium chloride, cerium nitrate, cerium acetate, cerium oxalate, cerium ammonium nitrate, strontium chloride, strontium formate, strontium acetate, strontium oxalate, strontium nitrate, strontium carbonate, strontium sulfate, iron chloride, iron oxalate, iron nitrate, Iron pyrophosphate, iron naphthenate, iron sulfate, ammonium sulfate, iron phosphate, nickel benzoate, nickel chloride, nickel citrate, nickel acetate, nickel hypophosphite, nickel bromide, nickel oxalate, nickel nitrate, carbonic acid Nickel, nickel sulfate, nickel ammonium sulfate, aluminum chloride, aluminum acetate, aluminum bromide, aluminum oxalate, aluminum nitrate, aluminum lactate, aluminum borate, aluminum iodide Aluminum, aluminum sulfate, sodium silicate, potassium silicate, colloidal silica, cobalt chloride, cobalt formate, cobalt acetate, cobalt oxalate, cobalt nitrate, cobalt stearate, cobalt carbonate, cobalt sulfate, ammonium cobalt sulfate, beryllium chloride, beryllium sulfate , Magnesium benzoate, magnesium chloride, magnesium perchlorate, magnesium acetate, magnesium bromide, magnesium oxalate, magnesium nitrate, magnesium lactate, magnesium fluoride, magnesium sulfate, ammonium magnesium sulfate, magnesium phosphate, ammonium magnesium phosphate, Calcium nitrate, calcium sulfite, calcium phosphite, calcium benzoate, calcium chloride, calcium peroxide, calcium formate, que Calcium phosphate, calcium glycerophosphate, calcium gluconate, calcium acetate, calcium salicylate, calcium hypochlorite, calcium bromide, calcium oxalate, calcium stearate, calcium carbonate, calcium lactate, calcium phosphate, calcium pyrophosphate, calcium phosphinate, iodine Calcium chloride, calcium sulfate, calcium chloride, barium chloride, barium nitrate, barium acetate, barium carbonate, chromium (III) chloride, chromium (III) acetate, chromium (III) bromide, chromium (III) nitrate, chromium sulfate, ( III), ammonium chromium (III) sulfate, chromium (III) phosphate and the like can be used.
[0045]
The source of nitrate ions is any compound containing it, such as nitric acid, zinc nitrate, ammonium nitrate, cerium ammonium nitrate, yttrium nitrate, indium nitrate, uranyl nitrate, potassium nitrate, calcium nitrate, sodium nitrate, chromium (III) nitrate, zirconyl nitrate , Strontium nitrate, cesium nitrate, cerium nitrate, cerium ammonium nitrate, thallium nitrate, iron nitrate, copper nitrate, sodium nitrate, nickel nitrate, neodymium nitrate, palladium nitrate, barium nitrate, bismuth nitrate, magnesium nitrate, europium nitrate, lanthanum nitrate, Lithium nitrate, rubidium nitrate, rhodium nitrate, etc. can be used.
[0046]
The source of fluorine is any compound containing it, such as hydrofluoric acid, acidic ammonium fluoride, zinc fluoride, yttrium fluoride, potassium fluoride, calcium fluoride, chromium fluoride (III), zirconium fluoride Potassium, potassium hydrogen fluoride, strontium fluoride, cesium fluoride, potassium titanium fluoride, copper fluoride sodium fluoride, barium fluoride, magnesium fluoride, lanthanum fluoride, lithium fluoride and the like can be used.
[0047]
The source of phosphorus oxyacid ions is any compound containing it, such as phosphorous acid, calcium phosphite, dipotassium phosphite, guanidine phosphate, glycerophosphate, calcium glycerophosphate, sodium glycerophosphate, hypophosphite , Ammonium hypophosphite, calcium hypophosphite, sodium hypophosphite, nickel hypophosphite, sodium tungstate, sodium naphthyl phosphate, sodium diphosphate, pyrophosphate, zinc pyrophosphate, potassium pyrophosphate, calcium pyrophosphate , Iron (III) pyrophosphate, copper (II) pyrophosphate, sodium pyrophosphate, sodium phenyl phosphate, metaphosphoric acid, potassium metaphosphate, sodium metaphosphate, phosphoric acid, zinc phosphate, aluminum phosphate, aluminum magnesium phosphate , Phosphate Monium, monosodium phosphate, potassium phosphate, calcium phosphate, guanidinium phosphate, chromium (III) phosphate, triammonium phosphate, tripotassium phosphate, trisodium phosphate, diammonium hydrogen phosphate, diammonium hydrogen phosphate Sodium, calcium hydrogen phosphate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, barium hydrogen phosphate and the like can be used.
[0048]
As a supply source of chloride ion, sulfate ion, and acetate ion, any compound containing the same, for example, hydrochloric acid, sulfuric acid, acetic acid, metal chloride, metal sulfate, metal acetate and the like can be used.
The aqueous liquid composition further comprises the aforementioned amine, amide and derivatives thereof, urea, thiourea and derivatives thereof, carboxylic acid, silica compound, surfactant, Na, K, Cu and Ag. When at least one selected from the group is contained, better corrosion resistance can be obtained.
[0049]
When an inorganic, organic or inorganic-organic composite coating film or a multilayer coating film thereof is further applied to the zinc plating formed in this manner and the protective film thereon, the corrosion resistance is further improved. In particular, the corrosion resistance of the coating solution containing 0.1 to 50% of the silica compound is good.
The kind of silica compound may be arbitrary, for example, various colloidal silicas, various sodium silicates, etc. can be used.
[0050]
All of the above are effective in obtaining corrosion resistance equal to or higher than that of conventional chromate coatings without using hexavalent chromium, but in particular, 1 to 80 g / L of zinc and 10 to 300 g / L of hydroxylated water. Selected from the group consisting of alkali and 0.4-40 g / L aliphatic amine or polymer thereof, alkylene oxide compound, 0.5-400 g / L carboxylic acid compound, 0.01-50 g / L polyvinyl alcohol. In the case of alloy plating, 1 mg / L to 1 g / L of iron, cobalt, 10 mg / L to 30 g / L nickel, 10 mg / L to 30 g / L manganese, 1 to 100 g A conductive base material is immersed in a zinc or zinc alloy plating bath containing at least one selected from the group consisting of / L tin, and the base material has a desired thickness. After plating, A) a source of trivalent chromium, B) a source of oxidizing material, and C) a water-soluble composition containing phosphorus oxyacid, oxyacid salt or anhydride thereof, or It is effective to form a protective film on the plating with a water-soluble composition containing at least one selected from the group consisting of valent chromium ions and chlorine ions, fluorine ions, nitrate ions, sulfate ions, and acetate ions. is there. Further, when an inorganic, organic or organic-inorganic composite coating film or a multilayer coating film thereof is formed on the protective film, the corrosion resistance is greatly improved. If the coating treatment solution contains a silica compound in an amount of 0.1 to 50%, the corrosion resistance is further improved.
[0051]
That is, a conductive base material is immersed in a plating bath containing the specific bath composition and / or specific additive described above, and zinc or zinc alloy plating with a desired thickness is performed on the base material. When a protective coating is formed with a specific aqueous liquid composition, the uniform coating formation, high leveling, and good wear properties of the plating promote the uniform formation of the protective coating. It can be fully drawn out, and it is possible to obtain corrosion resistance equivalent to or higher than that of conventional chromate coatings without using hexavalent chromium. Furthermore, by forming a coating film on the protective film, the corrosion resistance can be greatly improved.
[0052]
【Example】
Hereinafter, the present invention will be described by way of examples. The test piece was subjected to appropriate pretreatment (degreasing, desmutting, etc.) and then subjected to the following treatments.
Example 1
Zinc 12g / L, sodium hydroxide 130g / L, sodium gluconate 0.1g / L, plating containing 5mL of a reaction product of ethylenediamine and epichlorohydrin and 4mL / L of an aqueous solution containing 5% of a reaction product of imidazole and epichlorohydrin The test piece (SPCC, 50 × 100 mm, thickness 1 mm) was plated with the liquid. 2A / dm²When the test piece that was electrolyzed and plated with a film thickness of 8 μm was immersed in a solution containing chromium acetate (III) 25 g / L, 75% phosphoric acid 30 g / L and adjusted to pH 3 with ammonia for 30 seconds, A glossy treated appearance having a uniform interference color on the entire surface was obtained. When this test piece was put into a salt spray test (JIS Z 2371), the white rust generation time as rust of zinc was 168 hours, and the red rust generation time as rust of the iron base was 624 hours.
[0053]
Example 2
The test piece (SPCC, 50 × 100 mm, thickness 1 mm) was plated in a plating bath containing zinc 12 g / L, sodium hydroxide 130 g / L, “MIRAPOL100” 2.5 g / L, and vanillin 50 mg / L. . 2A / dm²When the test piece that was electrolyzed and plated with a film thickness of 8 μm was immersed in a solution containing chromium acetate (III) 25 g / L, 75% phosphoric acid 30 g / L and adjusted to pH 3 with ammonia for 30 seconds, A glossy treated appearance having a uniform interference color on the entire surface was obtained. When this test piece was put into a salt spray test (JIS Z 2371), the white rust generation time as rust of zinc was 168 hours, and the red rust generation time as rust of the iron base was 600 hours.
[0054]
Example 3
The test piece (SPCC, 50 × 100 mm, thickness 1 mm) was plated in a plating bath containing zinc 8 g / L, potassium hydroxide 130 g / L, “MIRAPOL100” 2.5 g / L, and vanillin 50 mg / L. . 2A / dm²When the test piece that was electrolyzed and plated with a film thickness of 8 μm was immersed in a solution containing chromium acetate (III) 25 g / L, 75% phosphoric acid 30 g / L and adjusted to pH 3 with ammonia for 30 seconds, A glossy treated appearance having a uniform interference color on the entire surface was obtained. When this test piece was put into a salt spray test (JIS Z 2371), the white rust generation time which is rust of zinc was 192 hours, and the red rust generation time which was rust of the iron base was 648 hours.
[0055]
Example 4
The test piece (SPCC, 50 × 100 mm, thickness 1 mm) was plated in a plating bath containing zinc 8 g / L, sodium hydroxide 100 g / L, “MIRAPOL550” 2.5 g / L, and vanillin 45 mg / L. . 2A / dm²The test piece, which was electrolyzed and plated with a thickness of 8 μm, contained chromium (III) nitrate 15 g / L, cobalt chloride 1 g / L, hypophosphorous acid 20 g / L, 60% nitric acid 18 g / L, and pH with ammonia. Was immersed in a solution adjusted to 2.5 for 45 seconds, a glossy treated appearance having a uniform interference color on the entire surface was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica and 1% caustic soda, and (3) one piece was colloidal. After coating with a coating solution containing 20% silica and 1% caustic soda, scratches reaching the iron substrate with a cutter knife on the diagonal of the test piece were performed, and then each was subjected to a salt spray test (JIS Z 2371). ), The white rust generation time, which is the rust of zinc, is 216 hours for (1), 624 hours for (2), and 288 hours for (3). 1) was 720 hours, (2) was 1920 hours, and (3) 1512 hours.
[0056]
Example 5
The test piece (SPCC, 50 × 100 mm, thickness 1 mm) was plated in a plating bath containing zinc 8 g / L, sodium hydroxide 100 g / L, “MIRAPOL550” 2.5 g / L, and vanillin 45 mg / L. . 2A / dm²The test piece that was electrolyzed and plated with a film thickness of 8 μm was 15 g / L of chromium nitrate (III), 5 g / L of colloidal silica (SI-550, manufactured by Catalyst Chemicals Co., Ltd.), 20 g / L of hypophosphorous acid, When immersed for 45 seconds in a solution containing 60% nitric acid 18 g / L and adjusted to pH 2.5 with ammonia, a glossy treated appearance having a uniform interference color on the entire surface was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica and 1% caustic soda, and (3) one piece was colloidal. After coating with a coating solution containing 20% silica and 1% caustic soda, scratches reaching the iron substrate with a cutter knife on the diagonal of the test piece were performed, and then each was subjected to a salt spray test (JIS Z 2371). ), The white rust generation time, which is the rust of zinc, is 216 hours for (1), 624 hours for (2), and 264 hours for (3). 1) was 696 hours, (2) was 1920 hours, and (3) was 1488 hours.
[0057]
Example 6
The test piece (SPCC, 50 × 100 mm, thickness 1 mm) was plated in a plating bath containing zinc 8 g / L, sodium hydroxide 100 g / L, “MIRAPOL550” 2.5 g / L, and vanillin 45 mg / L. . 2A / dm²The test piece, which was electrolyzed and plated with a thickness of 8 μm, was chromium (III) nitrate 15 g / L, hypophosphorous acid 20 g / L, 60% nitric acid 18 g / L, Adeka Thioace PD-50 (Asahi Denka ( When the product was immersed in a solution containing 0.5 g / L and adjusted to pH 2.5 with ammonia for 45 seconds, a glossy treated appearance having a uniform interference color on the entire surface was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica and 1% caustic soda, and (3) one piece was colloidal. After coating with a coating solution containing 20% silica and 1% caustic soda, scratches reaching the iron substrate with a cutter knife on the diagonal of the test piece were performed, and then each was subjected to a salt spray test (JIS Z 2371). ), The white rust generation time that is zinc rust is 216 hours for (1), 600 hours for (2), and 288 hours for (3), and the red rust generation time that is rust for iron base is ( 1) was 672 hours, (2) was 1896 hours, and (3) was 1536 hours.
[0058]
Example 7
Test piece (SPCC, 50 × 100 mm, thickness) in a plating bath containing zinc 12 g / L, sodium hydroxide 130 g / L, No. 3 sodium silicate 30 g / L, “MIRAPOL550” 3 g / L, anisaldehyde 30 mg / L 1 mm). 2A / dm²The test piece, which was electrolyzed and plated with a film thickness of 8 μm, contained 30 g / L of chromium (III) nitrate, 40 g / L of 75% phosphoric acid, and adjusted to pH 1.5 with sodium hydroxide for 30 seconds. When dipped, a glossy treated appearance having a uniform interference color on the entire surface was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica and 1% caustic soda, and (3) one piece was colloidal. After coating with a coating solution containing 20% silica and 1% caustic soda, scratches reaching the iron substrate with a cutter knife on the diagonal of the test piece were performed, and then each was subjected to a salt spray test (JIS Z 2371). ), The generation time of white rust, which is zinc rust, was 216 hours for (1), 624 hours for (2), and 240 hours for (3). Moreover, the red rust generation time which is a rust of an iron substrate was 720 hours for (1), 1944 hours for (2), and 1464 hours for (3).
[0059]
Example 8
Test pieces (SPCC, 50) in a plating bath containing zinc 18 g / L, sodium hydroxide 150 g / L, No. 3 sodium silicate 150 g / L, polymer 4 g / L of structural formula (8), and anisaldehyde 50 mg / L × 100 mm, thickness 1 mm). 2A / dm²When the test piece that was electrolyzed and plated with a film thickness of 8 μm was immersed in a solution containing chromium (III) sulfate 35 g / L, 75% phosphoric acid 45 g / L, and adjusted to pH 3 with ammonia for 60 seconds, A glossy treated appearance having a uniform interference color on the entire surface was obtained. When this test piece was put into a salt spray test (JIS Z 2371), the white rust generation time as rust of zinc was 192 hours, and the red rust generation time as rust of the iron base was 696 hours.
[0060]
Example 9
Test pieces (SPCC, 50 × 100 mm, thickness 1 mm) in a plating bath containing zinc 10 g / L, sodium hydroxide 120 g / L, iron 0.01 g / L, “MIRAPOL WT” 3 g / L, vanillin 40 mg / L ) Was plated. 2A / dm²An aqueous solution containing 10 g / L of chromium (III) nitrate, 25 g / L of 75% phosphoric acid and 25 g / L of 60% nitric acid was adjusted to pH 2.0 with ammonia. When immersed in the treatment liquid for 15 seconds, a glossy treated appearance having a uniform interference color was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica, 10% acrylic resin, and 3% butyl cellosolve. ) One sheet was coated with a coating solution containing 20% colloidal silica, 10% acrylic resin, and 3% butyl cellosolve, and then a scratch reaching the iron substrate with a cutter knife on the diagonal of the test piece. When each was put into the salt spray test (JIS Z 2371), the white rust generation time, which is the rust of zinc, was 168 hours for (1), 648 hours for (2), and 240 hours for (3). The generation time of red rust, which is rust, was 600 hours for (1), 1992 hours for (2), and 1392 hours for (3).
[0061]
Example 10
Test piece (SPCC, 50 × 100 mm, thickness 1 mm) in a plating bath containing zinc 7 g / L, potassium hydroxide 120 g / L, iron 0.01 g / L, “MIRAPOL WT” 3 g / L, vanillin 40 mg / L ) Was plated. 2A / dm²An aqueous solution containing 10 g / L of chromium (III) nitrate, 25 g / L of 75% phosphoric acid and 25 g / L of 60% nitric acid was adjusted to pH 2.0 with ammonia. When immersed in the treatment liquid for 15 seconds, a glossy treated appearance having a uniform interference color was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica and 1% caustic soda, and (3) one piece was colloidal. After coating with a coating solution containing 20% silica and 1% caustic soda, scratches reaching the iron substrate with a cutter knife on the diagonal of the test piece were performed, and then each was subjected to a salt spray test (JIS Z 2371). ), The white rust generation time, which is rust of zinc, is 168 hours for (1), 672 hours for (2), and 216 hours for (3). 1) was 624 hours, (2) was 2016 hours, and (3) was 1392 hours.
[0062]
Example 11
Except for including 0.01 g / L of cobalt in place of iron in the plating bath, the same treatment as in Example 10 was performed, and a glossy treated appearance having a uniform interference color on the entire surface was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica, 10% acrylic resin, and 3% butyl cellosolve. ) One sheet was coated with a coating solution containing 20% colloidal silica, 10% acrylic resin, and 3% butyl cellosolve, and then a scratch reaching the iron substrate with a cutter knife on the diagonal of the test piece. When each was put into the salt spray test (JIS Z 2371), the white rust generation time, which is the rust of zinc, was 168 hours for (1), 696 hours for (2), and 264 hours for (3). The occurrence time of red rust, which is rust, was 600 hours for (1), 2064 hours for (2), and 1440 hours for (3).
[0063]
Example 12
Test piece (SPCC, 50 × 100 mm) in a plating bath containing zinc 7 g / L, sodium hydroxide 90 g / L, iron 0.01 g / L, polymer 4 g / L of structural formula (6), and ethyl vanillin 30 mg / L And a thickness of 1 mm). 2A / dm²An aqueous solution containing 3 g / L of ammonium molybdate, 5 g / L of chromium (III) nitrate, 15 g / L of 75% phosphoric acid, and 5 g / L of 60% nitric acid was added to an aqueous solution containing 8 μm thick electrolyzed specimen. When dipped in a treatment solution adjusted to pH 2.0 for 15 seconds, a glossy treated appearance having a uniform interference color on the entire surface was obtained. When this test piece was put into a salt spray test (JIS Z 2371), the white rust generation time as rust of zinc was 192 hours, and the red rust generation time as rust of the iron base was 720 hours.
[0064]
Example 13
Except for including 0.01 g / L of nickel in place of iron in the plating bath, the same treatment as in Example 12 was performed to obtain a glossy treated appearance having a uniform interference color on the entire surface. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica, 10% acrylic resin, and 3% butyl cellosolve. ) One sheet was coated with a coating solution containing 20% colloidal silica, 10% acrylic resin, and 3% butyl cellosolve, and then a scratch reaching the iron substrate with a cutter knife on the diagonal of the test piece. When each was put into the salt spray test (JIS Z 2371), the occurrence of white rust, which is rust of zinc, was 192 hours for (1), 696 hours for (2), and 216 hours for (3). The occurrence time of red rust as rust of (1) was 720 hours, (2) was 2088 hours, and (3) was 1440 hours.
[0065]
Example 14
A plating bath containing 10 g / L of zinc, 120 g / L of sodium hydroxide, 50 g / L of No. 3 sodium silicate, 0.04 g / L of iron, 4 g / L of “MIRAPOL AD-1”, and 50 mg / L of heliotropin The test piece (SPCC, 50 × 100 mm, thickness 1 mm) was plated. 2A / dm²A test piece that was electrolyzed and plated with a thickness of 8 μm was prepared by adjusting an aqueous solution containing chromium (III) 15 g / L, phosphorous acid 20 g / L, 60% nitric acid 25 g / L to pH 2.0 with ammonia. When immersed in the liquid for 60 seconds, a glossy treated appearance having a uniform interference color on the entire surface was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica and 1% caustic soda, and (3) one piece was colloidal. After coating with a coating solution containing 20% silica and 1% caustic soda, scratches reaching the iron substrate with a cutter knife on the diagonal of the test piece were performed, followed by a salt spray test (JIS Z 2371), the white rust generation time, which is zinc rust, is 216 hours, (2) is 648 hours, (3) is 288 hours, and the red rust generation time, which is iron rust, is ( 1) was 720 hours, (2) was 2064 hours, and (3) was 1512 hours.
[0066]
Example 15
Except for containing 0.06 g / L of cobalt in place of iron in the plating bath, the same treatment as in Example 14 was performed, and a glossy treated appearance having a uniform interference color on the entire surface was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica, 10% acrylic resin, and 3% butyl cellosolve. ) One piece was coated with a coating solution containing 20% colloidal silica, 10% acrylic resin, and 3% butyl cellosolve, and then a scratch reaching the iron substrate with a cutter knife was placed on the diagonal of the test piece. Then, when each was put into the salt spray test (JIS Z 2371), the white rust generation time, which is the rust of zinc, was 216 hours, (2) 720 hours, (3) 264 hours, The occurrence time of red rust, which is the rust of the iron substrate, was 720 hours for (1), 2088 hours for (2), and 1464 hours for (3).
[0067]
Example 16
Test piece in a plating bath containing zinc 15 g / L, sodium hydroxide 150 g / L, No. 3 sodium silicate 150 g / L, iron 0.1 g / L, “MIRAPOL WT” 4 g / L, anisaldehyde 40 mg / L (SPCC, 50 × 100 mm, thickness 1 mm) was plated. 2A / dm²An aqueous solution containing 20 g / L of chromium (III) sulfate, 25 g / L of hypophosphorous acid, and 10 g / L of 60% nitric acid was adjusted to pH 2.5 with caustic soda. When immersed in the prepared treatment solution for 45 seconds, a glossy treated appearance having a uniform interference color on the entire surface was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica and 1% caustic soda, and (3) one piece was colloidal. After coating with a coating solution containing 20% silica and 1% caustic soda, scratches reaching the iron substrate with a cutter knife on the diagonal of the test piece were performed, followed by a salt spray test (JIS Z 2371), the white rust generation time that is rust of zinc is 240 hours for (1), 744 hours for (2), 240 hours for (3), and the red rust generation time that is rust of the iron base is (1) was 744 hours, (2) was 2136 hours, and (3) was 1488 hours.
[0068]
Example 17
Test piece in a plating bath containing zinc 15 g / L, sodium hydroxide 150 g / L, No. 3 sodium silicate 150 g / L, iron 0.1 g / L, “MIRAPOL WT” 4 g / L, anisaldehyde 40 mg / L (SPCC, 50 × 100 mm, thickness 1 mm) was plated. 2A / dm²An aqueous solution containing 20 g / L of chromium (III) sulfate, 1 g / L of cobalt chloride, 25 g / L of hypophosphorous acid, and 10 g / L of 60% nitric acid was applied to a test piece plated with a thickness of 8 μm. When immersed in a treatment solution adjusted to pH 2.5 with a soda solution for 45 seconds, a glossy treated appearance having a uniform interference color on the entire surface was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica and 1% caustic soda, and (3) one piece was colloidal. After coating with a coating solution containing 20% silica and 1% caustic soda, scratches reaching the iron substrate with a cutter knife on the diagonal of the test piece were performed, followed by a salt spray test (JIS Z 2371), the white rust generation time that is zinc rust is 312 hours for (1), 840 hours for (2), and 288 hours for (3), and the red rust generation time that is rust on the iron base. (1) was 816 hours, (2) was 2256 hours, and (3) was 1512 hours.
[0069]
Example 18
Test piece in a plating bath containing zinc 15 g / L, sodium hydroxide 150 g / L, No. 3 sodium silicate 150 g / L, iron 0.1 g / L, “MIRAPOL WT” 4 g / L, anisaldehyde 40 mg / L (SPCC, 50 × 100 mm, thickness 1 mm) was plated. 2A / dm²The test piece, which was electrolyzed and plated with a film thickness of 8 μm, was 20 g / L of chromium (III) sulfate, 25 g / L of hypophosphorous acid, 10 g / L of 60% nitric acid, colloidal silica (SI-550, Catalyst Chemical Co., Ltd.) ) Manufactured) When an aqueous solution containing 5 g / L was immersed in a treatment solution adjusted to pH 2.5 with caustic soda for 45 seconds, a glossy treated appearance having a uniform interference color on the entire surface was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica and 1% caustic soda, and (3) one piece was colloidal. After coating with a coating solution containing 20% silica and 1% caustic soda, scratches reaching the iron substrate with a cutter knife on the diagonal of the test piece were performed, followed by a salt spray test (JIS Z 2371), the white rust generation time that is zinc rust is 312 hours for (1), 840 hours for (2), and 288 hours for (3), and the red rust generation time that is rust on the iron base is (1) was 840 hours, (2) was 2280 hours, and (3) was 1512 hours.
[0070]
Example 19
Test piece in a plating bath containing zinc 15 g / L, sodium hydroxide 150 g / L, No. 3 sodium silicate 150 g / L, iron 0.1 g / L, “MIRAPOL WT” 4 g / L, anisaldehyde 40 mg / L (SPCC, 50 × 100 mm, thickness 1 mm) was plated. 2A / dm²The test piece, which was electrolyzed and plated with a thickness of 8 μm, was 20 g / L of chromium (III) sulfate, 25 g / L of hypophosphorous acid, 10 g / L of 60% nitric acid, Adeka Thioace PD-50 (Asahi Denka Co., Ltd.) )) When an aqueous solution containing 0.5 g / L was immersed in a treatment solution adjusted to pH 2.5 with caustic soda for 45 seconds, a glossy treated appearance having a uniform interference color on the entire surface was obtained. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica, 10% acrylic resin, and 3% butyl cellosolve. ) One sheet was coated with a coating solution containing 20% colloidal silica, 10% acrylic resin, and 3% butyl cellosolve, and then a scratch reaching the iron substrate with a cutter knife on the diagonal of the test piece. When each was put into the salt spray test (JIS Z 2371), the white rust generation time, which is the rust of zinc, was 312 hours for (1), 960 hours for (2), and 312 hours for (3). The occurrence time of red rust as rust of (1) was 816 hours, (2) was 2400 hours, and (3) was 1584 hours.
[0071]
Example 20
Plating containing zinc 8g / L, caustic soda 120g / L, sodium gluconate 35g / L, iron 0.06g / L, cobalt 0.04g / L, "MIRAPOL 100" 5g / L, vanillin 40mg / L The test piece (SPCC, 50 × 100 mm, thickness 1 mm) was plated with the liquid. 2A / dm²The test piece, which was electrolyzed and plated with a thickness of 8 μm, contained chromium (III) nitrate 15 g / L, cobalt chloride 1 g / L, hypophosphorous acid 20 g / L, 60% nitric acid 18 g / L, and pH with ammonia. Was immersed in a solution adjusted to 2.5 for 45 seconds to obtain a treated appearance having a uniform interference color. After coating these two test pieces with a coating solution containing 20% colloidal silica and 1% caustic soda, one piece is left as it is, and the other piece is placed on the diagonal line of the test piece with a cutter knife. When it was put into a salt spray test (JIS Z 2371) with scratches reaching, the white rust generation time, which is rust of zinc, was 984 hours for the former, and 312 hours for the latter, and the red rust generation time, which is rust of the iron base, was the former. Was 2520 hours and the latter was 1560 hours.
[0072]
Example 21
20 g / L of zinc, 150 g / L of caustic soda, 50 g / L of tartaric acid, 0.45 g / L of iron, 10% of a reaction product of dimethylamine and epichlorohydrin, 10% of N-methylpiperazine, 5% of a reaction product of imidazole and epichlorohydrin A test piece (SPCC, 50 × 100 mm, thickness 1 mm) was plated with a plating solution containing 8 mL / L of an aqueous solution containing 2 mL / L of an aqueous solution containing 2% heliotropin and 1% vanillin. 2A / dm²The test piece that was electrolyzed and plated with a film thickness of 8 μm contained 10 g / L of chromium (III) sulfate, 30 g / L of 75% phosphoric acid, and 5 g / L of 67.5% nitric acid. When immersed in the treatment liquid adjusted to 5 for 90 seconds, a treated appearance having a uniform black color was obtained. Two test pieces were prepared. One was directly coated, and the other was coated with a coating solution containing 20% colloidal silica, 10% acrylic resin, and 3% butyl cellosolve, and then a salt spray test (JIS In Z 2371), the white rust generation time as zinc rust was 312 hours in the former and 1128 hours in the latter, and the red rust as rust in the iron base was 720 hours in the former and 3504 hours in the latter.
[0073]
Example 22
Specimens with a plating solution containing 17 g / L of zinc, 140 g / L of caustic soda, 35 g / L of triethanolamine, 0.4 g / L of iron, 5 g / L of “MIRAPOL 100”, and 40 mg / L of vanillin (SPCC, 50 × 100 mm, thickness 1 mm). 2A / dm²The test piece, which was electrolyzed and plated with a thickness of 8 μm, contained chromium (III) nitrate 15 g / L, cobalt chloride 1 g / L, hypophosphorous acid 20 g / L, 60% nitric acid 18 g / L, and pH with ammonia. Was immersed in a solution adjusted to 2.5 for 45 seconds to obtain a treated appearance having a uniform black color. Three test pieces were prepared. (1) One piece was left as it was, (2) One piece was coated with a coating solution containing 20% colloidal silica and 1% caustic soda, and (3) one piece was colloidal. After coating with a coating solution containing 20% silica and 1% caustic soda, the test piece was scratched on the diagonal of the iron substrate with a cutter knife on the diagonal line, and each was subjected to a salt spray test (JIS Z 2371), the white rust generation time, which is zinc rust, is 288 hours for (1), 1008 hours for (2), and 288 hours for (3). (1) was 672 hours, (2) was 3264 hours, and (3) was 1488 hours.
[0074]
Example 23
Tested with plating solution containing 20 g / L of zinc, 180 g / L of ammonium chloride, 20% of β-naphthol ethylene oxide adduct, 10% of ethylenediaminepropion oxide adduct and 0.5 mL of benzalacetone 0.5 mL / L A piece (SPCC, 50 × 100 mm, thickness 1 mm) was plated. 2A / dm²When the test piece that was electrolyzed and plated with a film thickness of 8 μm was immersed in a solution containing chromium acetate (III) 25 g / L, 75% phosphoric acid 30 g / L and adjusted to pH 3 with ammonia for 30 seconds, A glossy treated appearance having a uniform interference color on the entire surface was obtained. When this test piece was put into the salt spray test (JIS Z 2371), the white rust generation time, which is rust of zinc, was 144 hours, and the red rust generation time, which was rust of the iron base, was 576 hours.
[0075]
Example 24
Contains 15 g / L of zinc, 150 g / L of sodium hydroxide, 150 g / L of No. 3 sodium silicate, 0.03 g / L of iron, 0.02 g / L of nickel, 4 g / L of “MIRAPOL WT”, 40 mg / L of anisaldehyde The hull cell test was carried out in the plating bath. An aqueous solution containing 20 g / L of chromium (III) sulfate, 25 g / L of hypophosphorous acid, and 10 g / L of 60% nitric acid was added to a treatment solution adjusted to pH 2.5 with caustic soda. When dipped for 2 seconds, a glossy treated appearance having a uniform interference color from the high current density part to the low current density part was obtained. 0.1, 0.5, 1, 2, 3, 5, 10 A / dm of this test piece² When the film thickness of the corresponding part was measured, the distribution in the column of the present invention in Table 1 was obtained.
[0076]
[Table 1]

[0077]
The Hull cell test is a test method in which a cathode is disposed obliquely with respect to the anode and electrolysis is performed to generate a gradient of current density on the cathode. Thickness etc.).
[0078]
Comparative Example 1
A specimen (SPCC, 50 x 100 mm, thickness 1 mm) plated with hot-dip galvanized 50 μm in thickness contains 25 g / L of chromium (III) acetate and 30 g / L of 75% phosphoric acid, and the pH is adjusted to 3 with ammonia. When immersed in the solution for 30 seconds, a processed appearance with a light interference color and less gloss was obtained. Two pieces of this test piece were prepared. One piece was left as it was, and the other piece was put on the salt spray test (JIS Z 2371) after scratching the iron substrate with a cutter knife on the diagonal of the test piece. The white rust generation time, which is zinc rust, was 48 hours for the former, and 24 hours for the latter, and the red rust generation time, which is rust for the iron base, was 432 hours for the former and 312 hours for the latter.
[0079]
Comparative Example 2
A specimen (SPCC, 50 × 100 mm, thickness 1 mm) subjected to hot dip galvanization with a film thickness of 50 μm includes chromium (III) nitrate 15 g / L, hypophosphorous acid 20 g / L, 60% nitric acid 18 g / L. When immersed in a solution adjusted to pH 2.5 with ammonia for 45 seconds, a processed appearance with a thin interference color and low gloss was obtained. Two pieces of this test piece were prepared. One piece was left as it was, and the other piece was put on the salt spray test (JIS Z 2371) after scratching the iron substrate with a cutter knife on the diagonal of the test piece. The white rust generation time, which is zinc rust, was 48 hours for the former, and 24 hours for the latter, and the red rust generation time, which was rust for the iron base, was 480 hours for the former and 288 hours for the latter.
[0080]
Comparative Example 3
A test piece (SPCC, 50 × 100 mm, thickness 1 mm) subjected to hot dip galvanization with a film thickness of 50 μm contains chromium (III) sulfate 35 g / L, 75% phosphoric acid 45 g / L, and the pH is adjusted to 3 with ammonia. When immersed in the prepared liquid for 60 seconds, a processed appearance with a light interference color and less gloss was obtained. Two pieces of this test piece were prepared. One piece was left as it was, and the other piece was put on the salt spray test (JIS Z 2371) after scratching the iron substrate with a cutter knife on the diagonal of the test piece. The white rust generation time, which is zinc rust, was 48 hours for the former, and 24 hours for the latter, and the red rust generation time, which was rust for the iron base, was 480 hours for the former and 312 hours for the latter.
[0081]
Comparative Example 4
A test piece (SPCC, 50 × 100 mm, thickness 1 mm) subjected to hot-dip galvanization of 50 μm is used to contain a colored chromate treatment solution (chromic acid (VI) 3 g / L, nitric acid 1 g / L, sulfuric acid 0.3 g / L). ) For 15 seconds, a processed appearance with interference color and gloss was obtained. Two pieces of this test piece were prepared. One piece was left as it was, and the other piece was put on the salt spray test (JIS Z 2371) after scratching the iron substrate with a cutter knife on the diagonal of the test piece. The white rust generation time, which is zinc rust, was 96 hours for the former, and 48 hours for the latter, and the red rust generation time, which was rust for the iron base, was 600 hours for the former and 336 hours for the latter.
[0082]
Comparative Example 5
A specimen (SPCC, 50 × 100 mm, thickness 1 mm) subjected to alloying hot dip galvanization with a film thickness of 50 μm was obtained by using 3 g / L of ammonium molybdate, 5 g / L of chromium (III) nitrate, 15 g / L of 75% phosphoric acid, When an aqueous solution containing 60% nitric acid 5 g / L was immersed in a treatment solution adjusted to pH 2.0 with ammonia for 15 seconds, a treated appearance with no interference color and less gloss was obtained. Two pieces of this test piece were prepared. One piece was left as it was, and the other piece was put on the salt spray test (JIS Z 2371) after scratching the iron substrate with a cutter knife on the diagonal of the test piece. The white rust generation time, which is zinc rust, was 48 hours for the former, and 24 hours for the latter, and the red rust generation time, which was rust for the iron base, was 504 hours for the former and 240 hours for the latter.
[0083]
Comparative Example 6
A test piece (SPCC, 50 × 100 mm, thickness 1 mm) subjected to alloying hot dip galvanization with a film thickness of 50 μm was treated with a colored chromate treatment solution (chromic acid (VI) 3 g / L, nitric acid 1 g / L, sulfuric acid 0.3 g / (Including L) for 15 seconds, a processed appearance with less gloss was obtained although there was an interference color. Two pieces of this test piece were prepared. One piece was left as it was, and the other piece was put on the salt spray test (JIS Z 2371) after scratching the iron substrate with a cutter knife on the diagonal of the test piece. The white rust generation time, which is zinc rust, was 144 hours for the former, and 72 hours for the latter, and the red rust generation time, which is rust for the iron base, was 576 hours for the former and 336 hours for the latter.
[0084]
Comparative Example 7
A hull cell test was performed using a plating solution containing 300 g / L of zinc borofluoride, 35 g / L of ammonium borofluoride, and 1 g / L of licorice as an additive. A test piece electrolyzed with 2A for 15 minutes was immersed in an aqueous solution containing 20 g / L of chromium sulfate, 25 g / L of hypophosphorous acid and 10 g / L of 60% nitric acid for 45 seconds, adjusted to pH 2.5 with sodium hydroxide. However, from the high electric part to the middle electric part, a processed appearance having a dull and slightly interference color was obtained, but the low electric part was not plated and the iron base was exposed. When this test piece was put into a salt spray test (JIS Z 2371), the white rust generation time of the portion where plating from the high electric portion to the middle electric portion was deposited was 24 hours. Moreover, red rust which is rust of iron occurred in the portion where the plating of the low electric portion did not deposit immediately after the addition. Also, 0.1, 0.5, 1, 2, 3, 5, 10 A / dm² When the film thickness of the corresponding part was measured, the distribution in the column of Comparative Example 7 in Table 1 was obtained.

Claims (8)

Zinc, hydroxide alkali, containing a silicon compound, a conductive further iron For alloy plating, cobalt, zinc or zinc alloy plating bath containing at least one selected from nickel or al the group consisting The base material is immersed in the base material and electrolyzed so that the base material is plated to a desired thickness, and then A) a source of trivalent chromium, B) a source of an oxidizing substance, and C) A metal surface treatment method in which a protective film is formed on zinc or zinc alloy plating without being electrolyzed, although immersed in an aqueous liquid composition containing a cobalt supply source. The aqueous liquid composition is further selected from the group consisting of Li, Mo, W, V, Nb, Ta, Ti, Zr, Ce, Sr, Fe, Ni, Al, Si , Be, Mg, Ca and Ba. The metal surface treatment method according to claim 1, comprising at least one of the above.   The metal surface treatment method according to claim 1 or 2, wherein the plating solution further contains an appropriate amount of aldehyde. The metal surface treatment method according to any one of claims 1 to 3, comprising 1 to 80 g / L of the zinc, 10 to 300 g / L of the alkali hydroxide, and 8.4 to 45 g / L of the silicon compound. . Said protective coating aqueous liquid composition chlorine ions for forming a fluoride ion, nitrate ion, in any one of claims 1 to 4 containing at least one selected from the group consisting of sulfate ion and acetate ion The metal surface treatment method as described. An aqueous liquid composition for forming the protective film further comprises amine, amide and derivatives thereof , urea, thiourea and derivatives thereof, carboxylic acid, silica compound, surfactant, Na, K, Cu and Ag. The metal surface treatment method according to any one of claims 1 to 5 , comprising at least one selected from the group consisting of: After formation of the protective coating, the substrate is further immersed in the coating treatment solution, by drying, inorganic any of claims 1 to 6 to form a coating film, or these multilayer coatings film of organic or organic-inorganic composite The metal surface treatment method according to claim 1. The metal surface treatment method according to claim 7 , wherein the coating treatment liquid contains a silica compound.