JP3665046B2 - Surface-treated steel sheet excellent in white rust resistance and method for producing the same - Google Patents

Description

上記化学構造式中、ｑは０〜５０の整数、好ましくは１〜４０の整数、特に好ましくは２〜２０の整数である。
このようなビスフェノールＡ型エポキシ樹脂は、当業界において広く知られた製造法により得ることができる。
【００３８】
上記エポキシ基含有樹脂のエポキシ基と反応する活性水素含有化合物としては、下記のものが挙げられる。
・活性水素を有するヒドラジン誘導体
・ 活性水素を有する第１級または第２級のアミン化合物
・ アンモニア、カルボン酸などの有機酸
・ 塩化水素などのハロゲン化水素類
・ アルコール類、チオール類
・ 活性水素を有しないヒドラジン誘導体または第３級アミンと酸との混合物である４級塩化剤
本発明ではこれらの１種または２種以上を使用できるが、優れた耐食性を得るために活性水素含有化合物の少なくとも一部（好ましくは全部）は、活性水素を有するヒドラジン誘導体であることが必要である。
【００３９】
上記活性化水素を有するアミン化合物の代表例としては、以下のものを挙げることができる。
(1) ジエチレントリアミン、ヒドロキシエチルアミノエチルアミン、エチルアミノエチルアミン、メチルアミノプロピルアミンなどの１個の２級アミノ基と１個以上の１級アミノ基を含有するアミン化合物の１級アミノ基を、ケトン、アルデヒドまたはカルボン酸と例えば１００〜２３０℃程度の温度で加熱反応させてアルジミン、ケチミン、オキサゾリンまたはイミダゾリンに変性した化合物；
(2) ジエチルアミン、ジエタノールアミン、ジ−ｎ−または−ｉｏｓ−プロパノールアミン、Ｎ−メチルエタノールアミン、Ｎ−エチルエタノールアミンなどの第２級モノアミン；
【００４０】
(3) モノエタノールアミンなどのようなモノアルカノールアミンとジアルキル（メタ）アクリルアミドとをミカエル付加反応により付加させて得られる第２級アミン含有化合物；
(4) モノエタノールアミン、ネオペンタノールアミン、２−アミノプロパノール、３−アミノプロパノール、２−ヒドロキシ−２′（アミノプロポキシ）エチルエーテルなどのアルカノールアミンの１級アミン基をケチミンに変性した化合物；
【００４１】
活性水素含有化合物の一部として使用できる上記４級塩化剤は、活性水素を有しないヒドラジン誘導体または第３級アミンはそれ自体ではエポキシ基と反応性を有しないので、これらをエポキシ基と反応可能とするために酸との混合物としたものである。４級塩化剤は、必要に応じて水の存在下でエポキシ基と反応し、エポキシ基含有樹脂と４級塩を形成する。４級塩化剤を得るために使用される酸は、酢酸、乳酸などの有機酸、塩酸などの無機酸のいずれでもよい。また、４級塩化剤を得るために使用される活性水素を有しないヒドラジン誘導体としては、例えば３，６−ジクロロピリダジンなどを、また、第３級アミンとしては、例えば、ジメチルエタノールアミン、トリエチルアミン、トリメチルアミン、トリイソプロピルアミン、メチルジエタノールアミンなどを挙げることができる。
【００４２】
上記活性水素含有化合物で最も有用で耐食性に優れた性能を発現するのが、活性水素を有するヒドラジン誘導体である。
活性水素を有するヒドラジン誘導体の具体例としては、例えば以下のものを挙げることができる。
▲１▼ カルボヒドラジド、プロピオン酸ヒドラジド、サリチル酸ヒドラジド、アジピン酸ジヒドラジド、セバシン酸ジヒドラジド、ドデカン酸ジヒドラジド、イソフタル酸ジヒドラジド、チオカルボヒドラジド、４，４′−オキシビスベンゼンスルホニルヒドラジド、ベンゾフェノンヒドラゾン、アミノポリアクリルアミドなどのヒドラジド化合物；
▲２▼ ピラゾール、３，５−ジメチルピラゾール、３−メチル−５−ピラゾロン、３−アミノ−５−メチルピラゾールなどのピラゾール化合物；
【００４３】
▲３▼ １，２，４−トリアゾール、３−アミノ−１，２，４−トリアゾール、４−アミノ−１，２，４−トリアゾール、３−メルカプト−１，２，４−トリアゾール、５−アミノ−３−メルカプト−１，２，４−トリアゾール、２，３−ジヒドロ−３−オキソ−１，２，４−トリアゾール、１Ｈ−ベンゾトリアゾール、１−ヒドロキシベンゾトリアゾール（１水和物）、６−メチル−８−ヒドロキシトリアゾロピリダジン、６−フェニル−８−ヒドロキシトリアゾロピリダジン、５−ヒドロキシ−７−メチル−１，３，８−トリアザインドリジンなどのトリアゾール化合物；
【００４４】
▲４▼ ５−フェニル−１，２，３，４−テトラゾール、５−メルカプト−１−フェニル−１，２，３，４−テトラゾールなどのテトラゾール化合物；
▲５▼ ５−アミノ−２−メルカプト−１，３，４−チアジアゾール、２，５−ジメルカプト−１，３，４−チアジアゾールなどのチアジアゾール化合物；
▲６▼ マレイン酸ヒドラジド、６−メチル−３−ピリダゾン、４，５−ジクロロ−３−ピリダゾン、４，５−ジブロモ−３−ピリダゾン、６−メチル−４，５−ジヒドロ−３−ピリダゾンなどのピリダジン化合物；
また、これらのなかでも５員環または６員環の環状構造を有し、環状構造中に窒素原子を有するピラゾール化合物、トリアゾール化合物が特に好適である。
これらのヒドラジン誘導体は１種を単独でまたは２種以上を混合して使用することができる。
【００４５】
エポキシ基含有樹脂と一部又は全部が活性水素を有するヒドラジン誘導体からなる活性水素含有化合物との反応生成物である、上記（ａ）の水分散性樹脂または水溶性樹脂は、エポキシ基含有樹脂と上記特定の活性水素含有化合物とを１０〜３００℃、好ましくは５０〜１５０℃で約１〜８時間程度反応させることにより得ることができる。
【００４６】
この反応は有機溶剤を加えて行ってもよく、使用する有機溶剤の種類は特に限定されない。例えば、アセトン、メチルエチルケトン、メチルイソブチルケトン、ジブチルケトン、シクロヘキサノンなどのケトン類；エタノール、ブタノール、２−エチルヘキシルアルコール、ベンジルアルコール、エチレングリコール、エチレングリコールモノイソプロピルエーテル、エチレングリコールモノブチルエーテル、エチレングリコールモノヘキシルエーテル、プロピレングリコール、プロピレングリコールモノメチルエーテル、ジエチレングリコール、ジエチレングリコールモノエチルエーテル、ジエチレングリコールモノブチルエーテルなどの水酸基を含有するアルコール類やエーテル類；酢酸エチル、酢酸ブチル、エチレングリコールモノブチルエーテルアセテートなどのエステル類；トルエン、キシレンなどの芳香族炭化水素等を例示でき、これらの１種または２種以上を使用することができる。また、これらのなかでエポキシ樹脂との溶解性、皮膜形成性などの面からは、ケトン系またはエーテル系の溶剤が特に好ましい。
【００４７】
エポキシ基含有樹脂と一部又は全部が活性水素を有するヒドラジン誘導体からなる活性水素含有化合物との配合比率は、活性水素基の数とエポキシ基の数との比率［活性水素基数／エポキシ基数］を０．０１〜１０、より好ましくは０．１〜８、さらに好ましくは０．２〜４とすることが耐食性、水分散性などの点から適当である。
【００４８】
また、活性水素含有化合物中における活性水素を有するヒドラジン誘導体の割合は１０〜１００モル％、より好ましくは３０〜１００モル％、さら好ましくは４０〜１００モル％とすることが適当である。活性水素を有するヒドラジン誘導体の割合が１０モル％未満では表面処理皮膜に十分な防錆機能を付与することができず、得られる防錆効果は皮膜形成有機樹脂とヒドラジン誘導体を単に混合して使用した場合と大差なくなる。
本発明では、以上のようにして得られるエポキシ基含有樹脂と一部または全部が活性水素を有するヒドラジン誘導体からなる活性水素含有化合物との反応生成物である、上記（ａ）の水分散性樹脂または水溶性樹脂の１種を単独でまたは２種以上を混合して使用することができる。
【００４９】
本発明では緻密なバリア皮膜を形成するために、樹脂組成物中に硬化剤を配合し、皮膜を加熱硬化させることが望ましい。樹脂組成物による皮膜を形成する場合の硬化方法としては、(1)イソシアネートと基体樹脂中の水酸基とのウレタン化反応を利用する硬化方法、(2)メラミン、尿素およびベンゾグアナミンの中から選ばれた１種以上にホルムアルデヒドを反応させてなるメチロール化合物の一部若しくは全部に炭素数１〜５の１価アルコールを反応させてなるアルキルエーテル化アミノ樹脂と基体樹脂中の水酸基との間のエーテル化反応を利用する硬化方法、が適当であるが、このうちイソシアネートと基体樹脂中の水酸基とのウレタン化反応を主反応とすることが特に好適である。
【００５０】
上記(1)の硬化方法で用いるポリイソシアネート化合物は、１分子中に少なくとも２個のイソシアネート基を有する脂肪族、脂環族（複素環を含む）または芳香族イソシアネート化合物、若しくはそれらの化合物を多価アルコールで部分反応させた化合物である。このようなポリイソシアネート化合物としては、例えば以下のものが例示できる。
【００５１】
▲１▼ ｍ−またはｐ−フェニレンジイソシアネート、２，４−または２，６−トリレンジイソシアネート、ｏ−またはｐ−キシリレンジイソシアネート、ヘキサメチレンジイソシアネート、ダイマー酸ジイソシアネート、イソホロンジイソシアネート
▲２▼ 上記▲１▼の化合物単独またはそれらの混合物と多価アルコール（エチレングリコール、プロピレングリコールなどの２価アルコール類；グリセリン、トリメチロールプロパンなどの３価アルコール；ペンタエリスリトールなどの４価アルコール；ソルビトール、ジペンタエリスリトールなどの６価アルコールなど）との反応生成物であって、１分子中に少なくとも２個のイソシアネートが残存する化合物
これらのポリイソシアネート化合物は、１種を単独でまたは２種以上を混合して使用できる。
【００５２】
また、ポリイソシアネート化合物の保護剤（ブロック剤）としては、例えば、▲１▼ メタノール、エタノール、プロパノール、ブタノール、オクチルアルコールなどの脂肪族モノアルコール類；
▲２▼ エチレングリコールおよび／またはジエチレングリコールのモノエーテル類、例えば、メチル、エチル、プロピル（ｎ−，ｉｓｏ）、ブチル（ｎ−，ｉｓｏ，ｓｅｃ）などのモノエーテル；
▲３▼ フェノール、クレゾールなどの芳香族アルコール；
▲４▼ アセトオキシム、メチルエチルケトンオキシムなどのオキシム；
などが使用でき、これらの１種または２種以上と前記ポリイソシアネート化合物とを反応させることにより、少なくとも常温下で安定に保護されたポリイソシアネート化合物を得ることができる。
【００５３】
このようなポリイソシアネート化合物（ａ2）は、エポキシ基含有樹脂と上記特定の活性水素含有化合物との反応生成物（ａ）（すなわち、上記（ａ）の成分である水分散性樹脂および／または水溶性樹脂）に対して、硬化剤として（ａ）／（ａ2）＝９５／５〜５５／４５（不揮発分の重量比）、好ましくは（ａ）／（ａ2）＝９０／１０〜６５／３５の割合で配合するのが適当である。ポリイソシアネート化合物には吸水性があり、これを（ａ）／（ａ2）＝５５／４５を超えて配合すると表面処理皮膜の密着性を劣化させてしまう。さらに、表面処理皮膜上に上塗り塗装を行った場合、未反応のポリイソシアネート化合物が塗膜中に移動し、塗膜の硬化阻害や密着性不良を起こしてしまう。このような観点から、ポリイソシアネート化合物（ａ2）の配合量は（ａ）／（ａ2）＝５５／４５以下とすることが好ましい。
【００５４】
なお、エポキシ基含有樹脂と上記特定の活性水素含有化合物との反応生成物である水分散性樹脂および／または水溶性樹脂は以上のような架橋剤（硬化剤）の添加により十分に架橋するが、さらに低温架橋性を増大させるため、公知の硬化促進触媒を使用することが望ましい。この硬化促進触媒としては、例えば、Ｎ−エチルモルホリン、ジブチル錫ジラウレート、ナフテン酸コバルト、塩化第１スズ、ナフテン酸亜鉛、硝酸ビスマスなどが使用できる。
また、付着性など若干の物性向上を狙いとして、エポキシ基含有樹脂とともに公知のアクリル、アルキッド、ポリエステル等の樹脂を混合して用いることもできる。
【００５５】
エポキシ基含有樹脂と特定の活性水素含有化合物との反応生成物を水分散化又は水溶化するには、例えば以下のような手法を採ることができる。
▲１▼ エポキシ基含有樹脂のエポキシ基と活性水素含有化合物である二塩基酸または第２級アミンを反応させ、中和剤である３級アミン、酢酸または燐酸などで中和、水分散化させる手法
▲２▼ エポキシ樹脂とポリエチレングリコール、ポリプロピレングリコールなどの末端水酸基含有ポリアルキレンオキサイドをイソシアネートと反応させてなる変性エポキシ樹脂（ａ3）を分散剤に用いて、水分散化させる手法。
▲３▼ 上記▲１▼と▲２▼を併用する手法
【００５６】
上記▲２▼及び▲３▼の手法を採る場合、エポキシ基含有樹脂と上記特定の活性水素含有化合物との反応生成物（ａ）（すなわち、上記（ａ）の成分である水分散性樹脂および／または水溶性樹脂）と上記変性エポキシ樹脂（ａ3）は（ａ）／（ａ3）＝９０／５〜６０／４０（不揮発分の重量比）、好ましくは（ａ）／（ａ3）＝８０／２０〜６５／３５の割合で配合するのが適当である。上記反応生成物（ａ）の配合率が（ａ）／（ａ3）＝９０／５を超えると樹脂の良好な分散性が得られず、樹脂粒子が粗大化して皮膜形成時に欠陥が生じるため目的とする性能が得られない。また上記変性エポキシ樹脂（ａ3）の配合率が（ａ）／（ａ3）＝６０／４０を超えると、親水性過多による耐食性の低下などの不具合が生じる。
【００５７】
表面処理組成物には、上述した特定の水分散性樹脂および／または水溶性樹脂以外に、その他の水分散性樹脂および／または水溶性樹脂として、例えば、アクリル系樹脂、ウレタン系樹脂、ポリエステル系樹脂、エポキシ系樹脂、エチレン系樹脂、アルキッド系樹脂、フェノール樹脂、オレフィン樹脂などの１種または２種以上を、全樹脂固形分中での割合で１５mass％程度を上限として配合してもよい。
【００５８】
また、上記（ａ）の成分である水分散性樹脂として、特定のポリアルキレングリコール変性エポキシ樹脂（Ａ）と、該ポリアルキレングリコール変性エポキシ樹脂（Ａ）以外のエポキシ基含有樹脂（Ｂ）と、活性水素を有するヒドラジン誘導体（Ｃ）と、さらに必要に応じてこのヒドラジン誘導体（Ｃ）以外の活性水素含有化合物（Ｄ）とを反応させて得られた水性エポキシ樹脂分散液（Ｘ）を用いることにより、特に優れた耐白錆性を得ることができる。
【００５９】
上記ポリアルキレングリコール変性エポキシ樹脂（Ａ）は、数平均分子量４００〜２００００のポリアルキレングリコールと、ビスフェノール型エポキシ樹脂と、活性水素含有化合物と、ポリイソシアネート化合物とを反応させて得られたものである。
上記ポリアルキレングリコールとしては、例えば、ポリエチレングリコール、ポリプロピレングリコール、ポリブチレングリコールなどを用いることができるが、そのなかでも特に、ポリエチレングリコールが好適である。ポリアルキレングリコールの数平均分子量は、得られる樹脂の水分散性、貯蔵性などの点から４００〜２００００、好ましくは５００〜１００００の範囲が適している。
また、上記ビスフェノール型エポキシ樹脂は、１分子中に少なくとも１個のエポキシ基を有するビスフェノール系化合物であって、特に、ビスフェノール系化合物とエピハロヒドリン（例えば、エピクロルヒドリン）との縮合反応によって得られるビスフェノールのジグリシジルエーテルが、可撓性および防食性に優れた皮膜が得られやすいため好適である。
【００６０】
ビスフェノール型エポキシ樹脂の調製に使用することができるビスフェノール系化合物の代表例としては、ビス（４−ヒドロキシフェニル）−２，２−プロパン、ビス（４−ヒドロキシフェニル）−１，１−エタン、ビス（４−ヒドロキシフェニル）−メタン、４，４´−ジヒドロキシジフェニルエーテル、４，４´−ジヒドロキシジフェニルスルホン、ビス（４−ヒドロキシフェニル）−１，１−イソブタン、ビス（４−ヒドロキシ−３−ｔ−ブチルフェニル）−２，２−プロパンなどが挙げられる。このようなビスフェノール系化合物を用いて調製されるエポキシ樹脂のうち、ビスフェノールＡ型エポキシ樹脂は可撓性および防食性などに優れた皮膜を得られるという点で特に好適である。
また、ビスフェノール型エポキシ樹脂は、ポリアルキレングリコール変性エポキシ樹脂の製造時における製造安定性などの点から、一般に約３１０〜１００００、特に望ましくは約３２０〜２０００の数平均分子量を有していることが好ましく、また、エポキシ当量は約１５５〜５０００、特に望ましくは約１６０〜１０００の範囲のものが好ましい。
【００６１】
上記活性水素含有化合物は、ポリアルキレングリコール変性エポキシ樹脂（Ａ）中のイソシアネート基のブロッキングのために使用されるものである。その代表的なものとしては、例えば、メタノール、エタノール、ジエチレングリコールモノブチルエーテルなどの１価アルコール；酢酸、プロピオン酸などの１価カルボン酸；エチルメルカプタンなどの１価チオールが挙げられる。また、それ以外のブロッキング剤（活性水素含有化合物）としては、ジエチルアミンなどの第２級アミン；ジエチレントリアミン、モノエタノールアミンなどの１個の第２級アミノ基又はヒドロキシル基と１個以上の第１級アミノ基を含有するアミン化合物の第１級アミノ基を、ケトン、アルデヒド若しくはカルボン酸と、例えば１００〜２３０℃の温度で加熱反応させることによりアルジミン、ケチミン、オキサゾリン若しくはイミダゾリンに変性した化合物；メチルエチルケトキシムなどのようなオキシム；フェノール、ノニルフェノールなどのフェノール類等が挙げられる。これらの化合物は一般に３０〜２０００、特に望ましくは３０〜２００の範囲の数平均分子量を有することが好ましい。
【００６２】
上記ポリイソシアネート化合物は、１分子中にイソシアネート基を２個以上、好ましくは２個または３個有する化合物であり、ポリウレタン樹脂の製造に一般に用いられるものが同様に使用できる。そのようなポリイソシアネート化合物としては、脂肪族系、脂環族系、芳香族系などのポリイソシアネート化合物が包含される。代表的なものとしては、ヘキサメチレンジイソシアネート（ＨＭＤＩ）、ＨＭＤＩのビウレット化合物、ＨＭＤＩのイソシアヌレート化合物などの脂肪族系ポリイソシアネート化合物；イソホロンジイソシアネート（ＩＰＤＩ）、ＩＰＤＩのビウレット化合物、ＩＰＤＩのイソシアヌレート化合物、水素添加キシリレンジイソシアネート、水素添加４，４´−ジフェニルメタンジイソシアネートなどの脂環族系ポリイソシアネート化合物；トリレンジイソシアネート、キシリレンジイソシアネートなどの芳香族系ポリイソシアネート化合物などを例示できる。
【００６３】
ポリアルキレングリコール変性エポキシ樹脂（Ａ）の製造時における各成分の配合割合は、一般には下記の範囲とするのが適当である。
すなわち、ポリアルキレングリコールの水酸基とポリイソシアネート化合物のイソシアネート基との当量比は１／１．２〜１／１０、好ましくは１／１．５〜１／５、特に好ましくは１／１．５〜１／３とするのが適当である。また、活性水素含有化合物の水酸基とポリイソシアネート化合物のイソシアネート基との当量比は１／２〜１／１００、好ましくは１／３〜１／５０、特に好ましくは１／３〜１／２０とするのが適当である。また、ポリアルキレングリコール、ビスフェノール型エポキシ樹脂および活性水素含有化合物の水酸基の合計量とポリイソシアネート化合物のイソシアネート基との当量比は１／１．５以下、好ましくは１／０．１〜１／１．５、特に好ましくは１／０．１〜１／１．１とするのが適当である。
【００６４】
上記ポリアルキレングリコール、ビスフェノール型エポキシ樹脂、活性水素含有化合物及びポリイソシアネート化合物の反応は、公知の方法により行うことができる。
上記で得られたポリアルキレングリコール変性エポキシ樹脂（Ａ）と、このポリアルキレングリコール変性エポキシ樹脂（Ａ）以外のエポキシ基含有樹脂（Ｂ）と、活性水素を有するヒドラジン誘導体（Ｃ）と、さらに必要に応じてこのヒドラジン誘導体（Ｃ）以外の活性水素含有化合物（Ｄ）とを反応させることにより、容易に水中に分散することができ、且つ素材に対する付着性の良好な水性エポキシ樹脂分散液（Ｘ）を得ることができる。
【００６５】
上記ポリアルキレングリコール変性エポキシ樹脂（Ａ）以外のエポキシ基含有樹脂（Ｂ）としては、ビスフェノールＡ、ビスフェノールＦ、ノボラック型フェノールなどのポリフェノール類とエピクロルヒドリンなどのエピハロヒドリンとを反応させてグリシジル基を導入してなるか、若しくはこのグリシジル基導入反応生成物にさらにポリフェノール類を反応させて分子量を増大させてなる芳香族エポキシ樹脂；さらには脂肪族エポキシ樹脂、脂環式エポキシ樹脂などが挙げられ、これらの１種を単独でまたは２種以上を混合して使用することができる。これらのエポキシ樹脂は、特に低温での皮膜形成性を必要とする場合には数平均分子量が１５００以上であることが好適である。
また、エポキシ基含有樹脂（Ｂ）としては、上記エポキシ基含有樹脂中のエポキシ基または水酸基に各種変性剤を反応させた樹脂を挙げることができ、例えば、乾性油脂肪酸を反応させたエポキシエステル樹脂；アクリル酸またはメタクリル酸などを含有する重合性不飽和モノマー成分で変性したエポキシアクリレート樹脂；イソシアネート化合物を反応させたウレタン変性エポキシ樹脂などを挙げることができる。
【００６６】
さらに、エポキシ基含有樹脂（Ｂ）としては、エポキシ基を有する不飽和モノマーとアクリル酸エステルまたはメタクリル酸エステルを必須とする重合性不飽和モノマー成分を溶液重合法、エマルション重合法または懸濁重合法などによって合成したエポキシ基含有モノマーと共重合したアクリル系共重合体樹脂を挙げることができ、上記重合性不飽和モノマー成分としては、例えば、メチル（メタ）アクリレート、エチル（メタ）アクリレート、プロピル（メタ）アクリレート、ｎ−、ｉｓｏ−若しくはｔｅｒｔ―ブチル（メタ）アクリレート、ヘキシル（メタ）アクリレート、２−エチルヘキシル（メタ）アクリレート、デシル（メタ）アクリレート、ラウリル（メタ）アクリレートなどのアクリル酸又はメタクリル酸のＣ１〜Ｃ２４のアルキルエステル；アクリル酸、メタクリル酸、スチレン、ビニルトルエン、アクリルアミド、アクリロニトリル、Ｎ−メチロール（メタ）アクリルアミド、Ｎ−メチロール（メタ）アクリルアミドのＣ１〜４アルキルエーテル化物；Ｎ，Ｎ−ジエチルアミノエチルメタクリレートなどを挙げることができる。また、エポキシ基を有する不飽和モノマーとしては、グリシジルメタアクリレート、グリシジルアクリレート、３，４エポキシシクロヘキシル−１−メチル（メタ）アクリレーなど、エポキシ基と重合性不飽和基を持つものであれば、特に制限されるものではない。
また、このアクリル系共重合体樹脂はポリエステル樹脂、エポキシ樹脂、フェノール樹脂などによって変性させた樹脂とすることもできる。
【００６７】
上記エポキシ基含有樹脂（Ｂ）として特に好ましいのは、ビスフェノールＡとエピパロヒドリンとの反応生成物である下記化学構造式に代表される樹脂であり、耐食性に優れているため特に好適である。
【化２】

上記化学構造式中、ｑは０〜５０の整数、好ましくは１〜４０の整数、特に好ましくは２〜２０の整数である。
このようなビスフェノールＡ型エポキシ樹脂は、当業界において広く知られた製造法により得ることができる。
【００６８】
上記エポキシ基含有樹脂（Ｂ）のエポキシ基と反応する活性水素含有化合物としては、下記のものが挙げられ、これらの詳細は先に述べた通りである。
・活性水素を有するヒドラジン誘導体
・活性水素を有する第１級または第２級のアミン化合物
・アンモニア、カルボン酸などの有機酸
・塩化水素などのハロゲン化水素類
・アルコール類、チオール類
・活性水素を有しないヒドラジン誘導体または第３級アミンと酸との混合物である４級塩化剤
上記水性エポキシ樹脂分散液（Ｘ）を調整する際には、これらの１種または２種以上を使用できるが、優れた耐食性を得るために、活性水素含有化合物の少なくとも一部（好ましくは全部）は、活性水素を有するヒドラジン誘導体であることが必要である。すなわち、これらのうち活性水素を有するヒドラジン誘導体（Ｃ）を必須成分とし、必要に応じてこのヒドラジン誘導体（Ｃ）以外の活性水素含有化合物（Ｄ）を用いる。
【００６９】
以上述べたようなポリアルキレングリコール変性エポキシ樹脂（Ａ）と、このポリアルキレングリコール変性エポキシ樹脂（Ａ）以外のエポキシ基含有樹脂（Ｂ）と、活性水素を有するヒドラジン誘導体（Ｃ）と、さらに必要に応じてこのヒドラジン誘導体（Ｃ）以外の活性水素含有化合物（Ｄ）とを、好ましくは１０〜３００℃、より好ましくは５０〜１５０℃の温度で約１〜８時間反応させ、これにより得られる樹脂を水中に分散させることにより、上述した水性エポキシ樹脂分散液（Ｘ）を得ることができる。
【００７０】
上記反応は有機溶剤を加えて行ってもよく、使用する有機溶剤の種類は特に限定されない。例えば、アセトン、メチルエチルケトン、メチルイソブチルケトン、ジブチルケトン、シクロヘキサノンなどのケトン類；エタノール、ブタノール、２−エチルヘキシルアルコール、ベンジルアルコール、エチレングリコール、エチレングリコールモノイソプロピルエーテル、エチレングリコールモノブチルエーテル、エチレングリコールモノヘキシルエーテル、プロピレングリコール、プロピレングリコールモノメチルエーテル、ジエチレングリコール、ジエチレングリコールモノエチルエーテル、ジエチレングリコールモノブチルエーテルなどの水酸基を含有するアルコール類やエーテル類；酢酸エチル、酢酸ブチル、エチレングリコールモノブチルエーテルアセテートなどのエステル類；トルエン、キシレンなどの芳香族炭化水素等を例示でき、これらの１種または２種以上を使用することができる。また、これらのなかでエポキシ樹脂との溶解性、皮膜形成性等の面からは、ケトン系またはエーテル系の溶剤が特に好ましい。
【００７１】
ポリアルキレングリコール変性エポキシ樹脂（Ａ）と、ポリアルキレングリコール変性エポキシ樹脂（Ａ）以外のエポキシ基含有樹脂（Ｂ）と、活性水素を有するヒドラジン誘導体（Ｃ）との配合比率は、ポリアルキレングリコール変性エポキシ樹脂（Ａ）およびエポキシ基含有樹脂（Ｂ）中のエポキシ基に対するヒドラジン誘導体（Ｃ）中の活性水素基の当量比が０．０１〜１０、好ましくは０．１〜８、さらに好ましくは０．２〜４となるようにすることが、耐食性や樹脂の水分散性などの観点から適当である。
また、活性水素を有するヒドラジン誘導体（Ｃ）の一部を活性水素含有化合物（Ｄ）に置き換えることもできるが、置き換える量としては９０モル％以下、好ましくは７０モル％以下、より好ましくは１０〜６０モル％の範囲内とすることが防食性、付着性の観点から適当である。
【００７２】
また、緻密なバリア皮膜を形成するために、水性エポキシ樹脂分散液（Ｘ）中に硬化剤を配合し、皮膜を加熱硬化させることが望ましい。樹脂組成物による皮膜を形成する場合の硬化方法としては、(1)イソシアネートと基体樹脂中の水酸基とのウレタン化反応を利用する硬化方法、(2)メラミン、尿素およびベンゾグアナミンの中から選ばれた１種以上にホルムアルデヒドを反応させてなるメチロール化合物の一部若しくは全部に炭素数１〜５の１価アルコールを反応させてなるアルキルエーテル化アミノ樹脂と基体樹脂中の水酸基との間のエーテル化反応を利用する硬化方法、が適当であるが、このうちイソシアネートと基体樹脂中の水酸基とのウレタン化反応を主反応とすることが特に好適である。
【００７３】
上記(1)の硬化方法で用いることができる硬化剤としてのポリイソシアネート化合物は、１分子中に少なくとも２個のイソシアネート基を有する脂肪族、脂環族（複素環を含む）または芳香族イソシアネート化合物、若しくはそれらの化合物を多価アルコールで部分反応させた化合物である。このようなポリイソシアネート化合物の具体例は先に述べたとおりであり、それらのポリイソシアネート化合物の１種を単独でまたは２種以上を混合して使用できる。
また、ポリイソシアネート化合物の保護剤（ブロック剤）の具体例も先に述べた通りであり、それらの１種または２種以上と前記ポリイソシアネート化合物とを反応させることにより、少なくとも常温下で安定に保護された硬化剤としてのポリイソシアネート化合物を得ることができる。
【００７４】
このようなポリイソシアネート化合物（ａ2）は、上記成分（Ａ）、（Ｂ）および（Ｃ）の成分（さらに必要に応じて上記（Ｄ）の成分）の反応生成物（ａ1）（すなわち上記（ａ）の成分である水分散性樹脂）に対して、硬化剤として（ａ1）／（ａ2）＝９５／５〜５５／４５（不揮発分の質量比）、好ましくは（ａ1）／（ａ2）＝９０／１０〜６５／３５の割合で配合するのが適当である。ポリイソシアネート化合物には吸水性があり、これを（ａ1）／（ａ2）＝５５／４５を超えて配合すると表面処理皮膜の密着性を劣化させてしまう。さらに、表面処理皮膜上に上塗り塗装を行った場合、未反応のポリイソシアネート化合物が塗膜中に移動し、塗膜の硬化阻害や密着性不良を起こしてしまう。このような観点から、ポリイソシアネート化合物（ａ2）の配合量は（ａ1）／（ａ2）＝５５／４５以下とすることが好ましい。
【００７５】
なお、上記（Ａ）、（Ｂ）および（Ｃ）の成分（さらに必要に応じて上記（Ｄ）の成分）の反応生成物である水分散性樹脂は、以上のような架橋剤（硬化剤）の添加により十分に架橋するが、さらに低温架橋性を増大させるため、公知の硬化促進触媒を使用することが望ましい。この硬化促進触媒としては、例えば、Ｎ−エチルモルホリン、ジブチル錫ジラウレート、ナフテン酸コバルト、塩化第１スズ、ナフテン酸亜鉛、硝酸ビスマスなどが使用できる。また、付着性など若干の物性向上を狙いとして、エポキシ基含有樹脂とともに公知のアクリル、アルキッド、ポリエステルなどの樹脂を混合して用いることもできる。
【００７６】
次に、上記（ｂ）の成分であるシランカップリング剤について説明する。
このシランカップリング剤としては、例えば、ビニルメトキシシラン、ビニルエトキシシラン、ビニルトリクロロシラン、ビニルトリメトキシシラン、ビニルトリエトキシシラン、β−（３，４エポキシシクロヘキシル）エチルトリメトキシシラン、γ−グリシドキシプロピルトリメトキシシラン、γ−グリシドキシプロピルメチルジエトキシシラン、γ−グリシドキシプロピルトリエトキシシラン、Ｎ−β（アミノエチル）γ−アミノプロピルメチルジメトキシシラン、Ｎ−β（アミノエチル）γ−アミノプロピルトリメトキシシラン、Ｎ−β（アミノエチル）γ−アミノプロピルトリメエキシシラン、γ−アミノプロピルトリメトキシシラン、γ−アミノプロピルトリエトキシシラン、γ−メタクリロキシプロピルメチルジメトキシシラン、γ−メタクリロキシプロピルトリメトキシシラン、γ−メタクリロキシプロピルメチルジエトキシシラン、γ−メタクリロキシプロピルトリエトキシシラン、γ−メルカプトプロピルメチルジメトキシシラン、γ−メルカプトプロピルトリメトキシシラン、ｐ−スチリルトリメトキシシラン、γ−アクリロキシプロピルトリメトキシシラン、Ｎ−フェニル−γ−アミノプロピルトリメトキシシラン、γ−ウレイドプロピルトリエトキシシラン、γ−クロロプロピルトリメトキシシラン、ビス（トリエトキシシリルプロピル）テトラスルフィド、γ−イソシアネートプロピルトリエトキシシラン、γ−トリエトキシシリル−Ｎ−（１，３−ジメチル−ブチリデン）プロピルアミン、Ｎ−（ビニルベンジルアミン）−β−アミノエチル−γ−アミノプロピルトリメトキシシランなどを挙げることができ、これらの１種を単独でまたは２種以上を混合して使用することができる。
【００７７】
本発明において、表面処理組成物が特定の酸成分とともにシランカップリング剤を含むことにより耐白錆性が向上するには、先に述べたような理由が考えられる。
また、上記シランカップリング剤のなかでも、上記（ａ）の水分散性樹脂および／または水溶性樹脂と反応性が高い官能基を有するという観点から、特に反応性官能基としてアミノ基を有するシランカップリング剤が好ましい。このようなシランカップリング剤としては、例えば、Ｎ−β（アミノエチル）γ−アミノプロピルメチルジメトキシシラン、Ｎ−β（アミノエチル）γ−アミノプロピルトリメトキシシラン、Ｎ−β（アミノエチル）γ−アミノプロピルトリメエキシシラン、γ−アミノプロピルトリメトキシシラン、γ−アミノプロピルトリエトキシシランなどが挙げられ、具体的には、信越化学（株）製のＫＢＭ−９０３、ＫＢＥ−９０３、ＫＢＭ−６０３、ＫＢＥ−６０２、ＫＢＥ−６０３（いずれも商品名）などを用いることができる。
【００７８】
シランカップリング剤の配合量は、上記（ａ）の成分である水分散性樹脂および／または水溶性樹脂の固形分１００重量部に対して１〜３００重量部、好ましくは５〜１００重量部、さらに好ましくは１５〜５０重量部とするのが適当である。シランカップリング剤の配合量が１重量部未満では耐食性が劣り、一方、３００重量部を超えると十分な皮膜が形成できないため、水分散性樹脂および／または水溶性樹脂との密着性とバリア性を高める効果が発揮できず、耐食性が低下する。
【００７９】
次に、上記（ｃ）の成分であるリン酸および／またはヘキサフルオロ金属酸は、不活性なめっき金属表面に作用してめっき金属表面を活性化させる作用を有する。このリン酸とヘキサフルオロ金属酸はそれぞれ単独で用いてもよいし、併用してもよい。
ヘキサフルオロ金属酸の種類は特に限定されないが、特にフッ化チタン酸、フッ化ジルコン酸、けいフッ酸などのようなＴｉ、Ｓｉ、Ｚｒの中から選ばれる１種以上の元素を含むヘキサフルオロ金属酸が好ましく、これらの１種または２種以上を用いることができる。
【００８０】
リン酸および／またはヘキサフルオロ金属酸の配合量は、上記（ａ）の成分である水分散性樹脂および／または水溶性樹脂の固形分１００重量部に対して、合計で０．1〜８０重量部、好ましくは１〜６０重量部、さらに好ましくは５〜５０重量部とするのが適当である。リン酸および／またはヘキサフルオロ金属酸の配合量が０．１重量部未満では耐食性が劣り、一方、８０重量部を超えると皮膜形成後の外観ムラが生じやすい。
【００８１】
表面処理組成物には、耐食性向上を目的として、必要に応じて水溶性リン酸塩を配合することができる。この水溶性リン酸塩としては、例えば、オルトリン酸、ピロリン酸、ポリリン酸、メタリン酸などの金属塩の１種又は２種以上を用いることができる。また、有機リン酸の塩（例えば、フィチン酸、フィチン酸塩、ホスホン酸、ホスホン酸塩およびこれらの金属塩）の１種以上を添加してもよい。また、それらのなかでも第一リン酸塩が表面処理組成物の安定性などの面から好適である。
皮膜中でのリン酸塩の存在形態も特別な限定はなく、また、結晶若しくは非結晶であるか否かも問わない。また、皮膜中でのリン酸塩のイオン性、溶解度についても特別な制約はない。水溶性リン酸塩を配合することにより耐食性が向上する理由は、水溶性リン酸塩が皮膜形成時に緻密な難溶性化合物を形成するためであると考えられる。
【００８２】
先に述べたようにシランカップリング剤は活性化されためっき金属と皮膜形成樹脂の両方と化学結合することで、めっき金属と皮膜形成樹脂との優れた密着性と耐食性が得られるが、めっき金属表面には不可避的に不活性な部分が存在し、このような不活性なサイトでは上記化学結合が生じにくく防錆効果を十分発揮できない。水溶性リン酸塩はこのようなめっき皮膜の部分に対して、皮膜形成時に緻密な難溶性化合物を形成する。すなわち、水溶性リン酸塩のリン酸イオンによるめっき皮膜の溶解に伴いめっき皮膜／表面処理組成物界面でｐＨが上昇し、その結果、水溶性リン酸塩の沈殿物皮膜が形成され、これが耐食性の向上に寄与する。
【００８３】
また、特に優れた耐食性を得るという観点からは、水溶性リン酸塩のカチオン種としてはＡｌ、Ｍｎ、Ｎｉ、Ｍｇが特に望ましく、これらの中から選ばれる１種以上の元素を含む水溶性リン酸塩を用いることが好ましい。このような水溶性リン酸塩としては、例えば、第一リン酸アルミニウム、第一リン酸マンガン、第一リン酸ニッケル、第一リン酸マグネシウムが挙げられ、これらのうちでも特に第一リン酸アルミニウムが最も好ましい。また、そのカチオン成分とＰ_２Ｏ_５成分のモル比［カチオン］／［Ｐ_２Ｏ_５］は０．４〜１．０であることが好ましい。モル比［カチオン］／［Ｐ_２Ｏ_５］が０．４未満では可溶性のリン酸によって皮膜の難溶性が損なわれ、耐食性が低下するので好ましくない。一方、１．０を超えると処理液安定性が著しく失われるので好ましくない。
【００８４】
この水溶性リン酸塩の配合量は、上記（ａ）の成分である水分散性樹脂および／または水溶性樹脂の固形分１００重量部に対して、固形分で０．１〜６０重量部、好ましくは０．５〜４０重量部、さらに好ましくは１〜３０重量部とするのが適当である。水溶性リン酸塩の配合量が０．１重量部未満では耐食性の向上効果が十分でなく、一方、６０重量部を超えると処理液のｐＨが低下するため反応性が強くなり、外観ムラを生じやすくなる。
【００８５】
表面処理組成物には、耐食性向上を目的として、必要に応じて非クロム系防錆添加剤を配合することができる。表面処理組成物中にこのような非クロム系防錆添加剤を配合することにより、特に優れた防食性能（自己補修性）を得ることができる。
この非クロム系防錆添加剤は、特に下記（ｅ1）〜（ｅ5）の群の中から選ばれる１つ以上を用いることが好ましい。
（ｅ1）酸化ケイ素
（ｅ 2 ）カルシウム化合物
（ｅ3）難溶性リン酸化合物
（ｅ4）モリブデン酸化合物
（ｅ5）トリアゾール類、チオール類、チアジアゾール類、チアゾール類、チウラム類の中から選ばれる１種以上の、Ｓ原子を含有する有機化合物
これら（ｅ1）〜（ｅ5）の非クロム系防錆添加剤の詳細及び防食機構は以下の通りである。
【００８６】
まず、上記（ｅ1）の成分としては微粒子シリカであるコロイダルシリカや乾式シリカを使用することができるが、耐食性の観点からは特に、カルシウムをその表面に結合させたカルシウムイオン交換シリカを使用するのが望ましい。
コロイダルシリカとしては、例えば、日産化学（株）製のスノーテックスＯ、２０、３０、４０、Ｃ、Ｓ（いずれも商品名）を用いることができ、また、ヒュームドシリカとしては、日本アエロジル（株）製のＡＥＲＯＳＩＬ Ｒ９７１、Ｒ８１２、Ｒ８１１、Ｒ９７４、Ｒ２０２、Ｒ８０５、１３０、２００、３００、３００ＣＦ（いずれも商品名）を用いることができる。また、カルシウムイオン交換シリカとしては、W.R.Grace＆Co．製のＳＨＩＥＬＤＥＸ Ｃ３０３、ＳＨＩＥＬＤＥＸ ＡＣ３、ＳＨＩＥＬＤＥＸ ＡＣ５（いずれも商品名）、富士シリシア化学（株）製のＳＨＩＥＬＤＥＸ、ＳＨＩＥＬＤＥＸ ＳＹ７１０（いずれも商品名）などを用いることができる。これらシリカは、腐食環境下において緻密で安定な亜鉛の腐食生成物の生成に寄与し、この腐食生成物がめっき表面に緻密に形成されることによって、腐食の促進を抑制する。
【００８７】
また、上記（ｅ2）、（ｅ3）の成分は沈殿作用によって特に優れた防食性能（自己補修性）を発現する。
上記（ｅ2）の成分であるカルシウム化合物は、カルシウム酸化物、カルシウム水酸化物、カルシウム塩のいずれでもよく、これらの１種または２種以上を使用できる。また、カルシウム塩の種類にも特に制限はなく、ケイ酸カルシウム、炭酸カルシウム、リン酸カルシウムなどのようなカチオンとしてカルシウムのみを含む単塩のほか、リン酸カルシウム・亜鉛、リン酸カルシウム・マグネシウムなどのようなカルシウムとカルシウム以外のカチオンを含む複塩を使用してもよい。この（ｅ2）の成分は、腐食環境下においてめっき金属である亜鉛やアルミニウムよりも卑なカルシウムが優先溶解し、これがカソード反応により生成したＯＨ⁻と緻密で難溶性の生成物として欠陥部を封鎖し、腐食反応を抑制する。また、上記のようなシリカとともに配合された場合には、表面にカルシウムイオンが吸着し、表面電荷を電気的に中和して凝集する。その結果、緻密で且つ難溶性の保護皮膜が生成して腐食が封鎖し、腐食反応を抑制する。
【００８８】
また、上記（ｅ3）である難溶性リン酸化合物としては、難溶性リン酸塩を用いることができる。この難溶性リン酸塩は単塩、複塩などの全ての種類の塩を含む。また、それを構成する金属カチオンに限定はなく、難溶性のリン酸亜鉛、リン酸マグネシウム、リン酸カルシウム、リン酸アルミニウムなどのいずれの金属カチオンでもよい。また、リン酸イオンの骨格や縮合度などにも限定はなく、正塩、二水素塩、一水素塩または亜リン酸塩のいずれでもよく、さらに、正塩はオルトリン酸塩の他、ポリリン酸塩などの全ての縮合リン酸塩を含む。この難溶性リン化合物は、腐食によって溶出しためっき金属の亜鉛やアルミニウムが、加水分解により解離したリン酸イオンと錯形成反応により緻密で且つ難溶性の保護皮膜を生成して腐食起点を封鎖し、腐食反応を抑制する。
【００８９】
また、上記（ｅ4）のモリブデン酸化合物としては、例えば、モリブデン酸塩を用いることができる。このモリブデン酸塩は、その骨格、縮合度に限定はなく、例えばオルトモリブデン酸塩、パラモリブデン酸塩、メタモリブデン酸塩などが挙げられる。また、単塩、複塩などの全ての塩を含み、複塩としてはリン酸モリブデン酸塩などが挙げられる。モリブデン酸化合物は不動態化効果によって自己補修性を発現する。すなわち、腐食環境下で溶存酸素と共にめっき皮膜表面に緻密な酸化物を形成することで腐食起点を封鎖し、腐食反応を抑制する。
【００９０】
また、上記（ｅ5）の有機化合物としては、例えば、以下のようなものを挙げることができる。すなわち、トリアゾール類としては、１，２，４−トリアゾール、３−アミノ−１，２，４−トリアゾール、３−メルカプト−１，２，４−トリアゾール、５−アミノ−３−メルカプト−１，２，４−トリアゾール、１Ｈ−ベンゾトリアゾールなどが、またチオール類としては、１，３，５−トリアジン−２，４，６−トリチオール、２−メルカプトベンツイミダゾールなどが、またチアジアゾール類としては、５−アミノ−２−メルカプト−１，３，４−チアジアゾール、２，５−ジメルカプト−１，３，４−チアジアゾールなどが、またチアゾール類としては、２−Ｎ，Ｎ−ジエチルチオベンゾチアゾール、２−メルカプトベンゾチアゾール類などが、またチウラム類としては、テトラエチルチウラムジスルフィドなどが、それぞれ挙げられる。これらの有機化合物は吸着効果によって自己補修性を発現する。すなわち、腐食によって溶出した亜鉛やアルミニウムがこれらの有機化合物が有する硫黄を含む極性基に吸着して不活性皮膜を形成することで腐食起点を封鎖し、腐食反応を抑制する。
【００９１】
非クロム系防錆添加剤の配合量は、上記（ａ）の成分である水分散性樹脂および／または水溶性樹脂の固形分１００重量部に対して、固形分で０．1〜５０重量部、好ましくは０．５〜３０重量部、さらに好ましくは１〜２０重量部とするのが適当である。この非クロム系防錆添加剤の配合量が０．１重量部未満では、耐アルカリ脱脂後の耐食性向上効果が十分に得られず、一方、５０重量部を超えると塗装性及び加工性が低下するだけでなく、耐食性も低下するので好ましくない。
なお、上記（ｅ1）〜（ｅ5）の防錆添加剤を２種以上複合添加してもよく、この場合にはそれぞれ固有の防食作用が複合化されるため、より高度の耐食性が得られる。特に、上記（ｅ1）の成分としてカルシウムイオン交換シリカを用い、且つこれに（ｅ3）、（ｅ4）、（ｅ5）の成分の１種以上、特に好ましくは（ｅ3）〜（ｅ5）の成分の全部を複合添加した場合に特に優れた耐食性が得られる。
【００９２】
表面処理組成物には、皮膜の加工性を向上させる目的で、必要に応じて固形潤滑剤を配合することができる。この固形潤滑剤としては、以下のようなものが挙げられる。
(1) ポリオレフィンワックス，パラフィンワックス：例えば、ポリエチレンワックス、合成パラフィン、天然パラフィン、マイクロワックス、塩素化炭化水素など
(2) フッ素樹脂微粒子：例えば、ポリフルオロエチレン樹脂（ポリ４フッ化エチレン樹脂等）、ポリフッ化ビニル樹脂、ポリフッ化ビニリデン樹脂など
【００９３】
この他にも、脂肪酸アミド系化合物（例えば、ステアリン酸アミド、パルミチン酸アミド、メチレンビスステアロアミド、エチレンビスステアロアミド、オレイン酸アミド、エシル酸アミド、アルキレンビス脂肪酸アミドなど）、金属石けん類（例えば、ステアリン酸カルシウム、ステアリン酸鉛、ラウリン酸カルシウム、パルミチン酸カルシウムなど）、金属硫化物（例えば、二硫化モリブデン、二硫化タングステンなど）、グラファイト、フッ化黒鉛、窒化ホウ素、ポリアルキレングリコール、アルカリ金属硫酸塩などを用いてもよい。
【００９４】
以上の固形潤滑剤のなかでも、特にポリエチレンワックス、フッ素樹脂系化合物（なかでも、ポリ４フッ化エチレン樹脂微粒子）が好適である。ポリエチレンワックスとしては、ヘキスト社製のセリダスト９６１５Ａ、３７１５、３６２０、３９１０（いずれも商品名）、三洋化成（株）製のサンワックス１３１−Ｐ、１６１−Ｐ（いずれも商品名）、三井石油化学（株）製のケミパールＷ−１００、Ｗ−２００、Ｗ−５００、Ｗ−８００、Ｗ−９５０（いずれも商品名）などを用いることができる。
【００９５】
フッ素樹脂微粒子としては、テトラフルオロエチレン微粒子が特に好ましく、ダイキン工業（株）製のルブロンＬ−２、Ｌ−５（いずれも商品名）、三井・デュポン社製のＭＰ１１００、１２００（いずれも商品名）、旭アイシーアイフロロポリマーズ（株）製のフルオンディスパージョンＡＤ１、ＡＤ２、フルオンＬ１４０Ｊ、Ｌ１５０Ｊ、Ｌ１５５Ｊ（いずれも商品名）などが好適である。
また、これらのなかで、ポリオレフィンワックスとテトラフルオロエチレンの併用により特に優れた潤滑効果が期待できる。
固形潤滑剤の配合量は、上記（ａ）の成分である水分散性樹脂および／または水溶性樹脂の固形分１００重量部に対して、固形分で１〜５０重量部、好ましくは３〜３０重量部とするのが適当である。上記（ａ）の成分である潤滑剤の配合量が１重量部未満では潤滑効果が乏しく、一方８０重量部を超えると塗装性が低下する。
【００９６】
また、表面処理皮膜（および表面処理組成物）中には、腐食抑制剤として、他の酸化物微粒子（例えば、酸化アルミニウム、酸化ジルコニウム、酸化チタン、酸化セリウム、酸化アンチモンなど）、リンモリブデン酸塩（例えば、リンモリブデン酸アルミニウムなど）、有機リン酸およびその塩（例えば、フィチン酸、フィチン酸塩、ホスホン酸、ホスホン酸塩、及びこれらの金属塩、アルカリ金属塩、アルカリ土類金属塩など）、有機インヒビター（例えば、ヒドラジンおよびその誘導体、チオール化合物、チオカルバミン酸塩など）などの１種または２種以上を添加できる。
【００９７】
さらに必要に応じて、表面処理皮膜（および表面処理組成物）中には添加剤として、有機着色顔料（例えば、縮合多環系有機顔料、フタロシアニン系有機顔料など）、着色染料（例えば、水溶性アゾ系金属染料など）、無機顔料（例えば、酸化チタンなど）、導電性顔料（例えば、亜鉛、アルミニウム、ニッケルなどの金属粉末、リン化鉄、アンチモンドープ型酸化錫など）、カップリング剤（例えば、チタンカップリング剤など）、メラミン・シアヌル酸付加物などの１種または２種以上を添加することができる。
【００９８】
以上のような成分を含む表面処理組成物により形成される表面処理皮膜は、乾燥膜厚が０．０２〜５μｍ、好ましくは０．０５〜５μｍ、より好ましくは０．３〜３μｍ、さらに好ましく０．５〜２μｍとする。乾燥膜厚が０．０２μｍ未満では耐食性が不十分であり、一方、５μｍを超えると導電性や加工性が低下する。
また、以上述べた表面処理皮膜の上層には、第２層皮膜として有機樹脂皮膜を形成することができる。この場合、第２層皮膜である有機樹脂皮膜の皮膜厚を０．０２μｍ以上５μｍ未満、好ましくは０．０５μｍ以上５μｍ未満とするとともに、第１層皮膜である上記表面処理皮膜の膜厚を０．０２μｍ以上５μｍ未満、好ましくは０．０５μｍ以上５μｍ未満とし、且つ両皮膜の合計が５μｍを超えないようにすることが好ましい。
【０１１１】
次に、本発明の表面処理鋼板の製造方法について説明する。
亜鉛系めっき鋼板またはアルミニウム系めっき鋼板の表面に上記表面処理皮膜を形成するには、上述した組成を有する表面処理組成物（処理液）を乾燥皮膜厚が上記範囲となるようにめっき鋼板面に塗布し、水洗することなく加熱乾燥させる。
表面処理組成物（処理液）はｐＨ０．５〜６、好ましくは２〜４に調整することが望ましい。表面処理組成物のｐＨが０．５未満では処理液の反応性が強すぎるため外観ムラが生じ、一方、ｐＨが６を超えると処理液の反応性が低くなり、めっき金属と皮膜との結合が不十分となり耐食性が低下する。
【０１１２】
表面処理組成物をめっき鋼板面に形成する方法としては、塗布法、浸漬法、スプレー法のいずれでもよい。塗布処理方法としては、ロールコーター（３ロール方式、２ロール方式など）、スクイズコーター、ダイコーターなどいずれの方法でもよい。また、スクイズコーターなどによる塗布処理または浸漬処理、スプレー処理の後に、エアナイフ法やロール絞り法により塗布量の調整、外観の均一化、膜厚の均一化を行うことも可能である。
【０１１３】
表面処理組成物をコーティングした後は、水洗することなく加熱乾燥を行う。加熱乾燥手段としては、ドライヤー、熱風炉、高周波誘導加熱炉、赤外線炉などを用いることができる。加熱乾燥は到達板温で３０〜３００℃、好ましくは５０〜３００℃、より好ましくは６０℃〜２５０の範囲で行うことが望ましい。この加熱乾燥温度が３０℃未満では皮膜中に水分が多量に残り、耐食性が不十分となる。また、３００℃を超えると非経済的であるばかりでなく、皮膜に欠陥が生じ耐食性が低下する。
また、上記のようにして形成された表面処理皮膜の上層に第２層皮膜として有機樹脂皮膜を形成する場合には、第２層皮膜用の処理組成物を上述した膜厚となるよう上記表面処理皮膜面に塗布し、加熱乾燥させる。処理組成物の塗布や加熱乾燥は、上述した表面処理皮膜の形成に用いた方法に準じて行えばよい。
【０１１４】
したがって、本発明の製造方法およびその好ましい実施形態は以下のとおりである。
[1] 亜鉛系めっき鋼板又はアルミニウム系めっき鋼板の表面に、
（ａ）エポキシ基含有樹脂と活性水素含有化合物との反応生成物であって、且つ前記活性水素含有化合物の一部又は全部が活性水素を有するヒドラジン誘導体である水分散性樹脂および／または水溶性樹脂と、
（ｂ）シランカップリング剤と、
（ｃ）リン酸および／またはヘキサフルオロ金属酸
を含有し、ｐＨが０．５〜６に調製された表面処理組成物を塗布し、水洗することなく５０℃〜３００℃の到達板温で加熱乾燥し、皮膜厚が０．０２〜５μｍの表面処理皮膜を形成することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
【０１１５】
[2] 上記[1]の製造方法において、表面処理組成物が、シランカップリング剤を水分散性樹脂および／または水溶性樹脂の固形分１００重量部に対して１〜３００重量部、リン酸および／またはヘキサフルオロ金属酸を水分散性樹脂および／または水溶性樹脂の固形分１００重量部に対して０．１〜８０重量部含有することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
[3] 上記[1]または[2]の製造方法において、表面処理組成物がさらに、水溶性リン酸塩を、水分散性樹脂および／または水溶性樹脂の固形分１００重量部に対して固形分で０．１〜６０重量部含有することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
【０１１６】
[4] 上記[3]の製造方法において、表面処理組成物が水溶性リン酸塩として、カチオン成分とＰ_２Ｏ_５成分のモル比［カチオン］／［Ｐ_２Ｏ_５］が０．４〜１．０であって、且つカチオン種がＭｎ、Ｍｇ、Ａｌ、Ｎｉの中から選ばれる１種以上である水溶性リン酸塩を含有することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
[5] 上記[1]〜[4]のいずれかの製造方法において、表面処理組成物がさらに、非クロム系防錆添加剤を、水分散性樹脂および／または水溶性樹脂の固形分１００重量部に対して固形分で０．１〜５０重量部含有することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
【０１１７】
[6] 上記 [5]の製造方法において、表面処理組成物が非クロム系防錆添加剤として、下記（ｅ1）〜（ｅ5）の群の中から選ばれる１つ以上の防錆添加剤を含有することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
（ｅ1）酸化ケイ素
（ｅ 2 ）カルシウム化合物
（ｅ3）難溶性リン酸化合物
（ｅ4）モリブデン酸化合物
（ｅ5）トリアゾール類、チオール類、チアジアゾール類、チアゾール類、チウラム類の中から選ばれる１種以上の、Ｓ原子を含有する有機化合物
【０１１８】
[7] 上記[1]〜[6]のいずれかの製造方法において、表面処理組成物がさらに、固形潤滑剤を、水分散性樹脂および／または水溶性樹脂の固形分１００重量部に対して固形分で１〜５０重量部含有することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
[8] 上記[1]〜[7]のいずれかの製造方法において、表面処理組成物が、シランカップリング剤として、反応性官能基としてアミノ基を有するシランカップリング剤の少なくとも１種を含有することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
【０１１９】
[9] 上記[1]〜[8]のいずれかの製造方法において、表面処理組成物が、ヘキサフルオロ金属酸としてＴｉ、Ｓｉ、Ｚｒの中から選ばれる１種以上の元素を含むヘキサフルオロ金属酸の少なくとも１種を含有することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
[10] 上記[5]〜[9]のいずれかの製造方法において、表面処理組成物が、非クロム系防錆添加剤としてカルシウムイオン交換シリカを含有することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
【０１２０】
[11] 上記[1]〜[10]のいずれかの製造方法において、表面処理組成物が、（ａ）の成分として水分散性樹脂を含有し、該水分散性樹脂は、数平均分子量４００〜２００００のポリアルキレングリコール、ビスフェノール型エポキシ樹脂、活性水素含有化合物及びポリイソシアネート化合物を反応せて得られたポリアルキレングリコール変性エポキシ樹脂（Ａ）と、該ポリアルキレングリコール変性エポキシ樹脂（Ａ）以外のエポキシ基含有樹脂（Ｂ）と、活性水素を有するヒドラジン誘導体（Ｃ）とを反応させて得られた水性エポキシ樹脂分散液であることを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
【０１２１】
[12] 上記[1]〜[10]のいずれかの製造方法において、表面処理組成物が、（ａ）の成分として水分散性樹脂を含有し、該水分散性樹脂は、数平均分子量４００〜２００００のポリアルキレングリコール、ビスフェノール型エポキシ樹脂、活性水素含有化合物及びポリイソシアネート化合物を反応させて得られたポリアルキレングリコール変性エポキシ樹脂（Ａ）と、該ポリアルキレングリコール変性エポキシ樹脂（Ａ）以外のエポキシ基含有樹脂（Ｂ）と、活性水素を有するヒドラジン誘導体（Ｃ）と、該ヒドラジン誘導体（Ｃ）以外の活性水素含有化合物（Ｄ）とを反応させて得られた水性エポキシ樹脂分散液であることを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
【０１２２】
[13] 上記[11]または[12]の製造方法において、エポキシ基含有樹脂（Ｂ）が、数平均分子量１５００〜１００００、エポキシ当量１５０〜５０００のビスフェノールＡ型エポキシ樹脂であることを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
[14] 上記[11]〜[13]のいずれかの製造方法において、水性エポキシ樹脂分散液がさらに、水酸基と架橋する基を有する硬化剤を含有することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
[15] 上記[1]〜[14]のいずれかの製造方法において、皮膜厚が０．０５〜５μmの表面処理皮膜を形成することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
【０１２３】
[16] 上記[1]〜[14]のいずれかの製造方法により得られた表面処理鋼板の皮膜厚を０．０２μｍ以上５μｍ未満とした表面処理皮膜の上層に、皮膜厚が０．０２μｍ以上５μｍ未満の有機樹脂皮膜を、前記表面処理皮膜厚と合計した皮膜厚が５μｍ以下となるように形成することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
[17] 上記[15]の製造方法により得られた表面処理鋼板の皮膜厚を０．０５μｍ以上５μｍ未満とした表面処理皮膜の上層に、皮膜厚が０．０５μｍ以上５μｍ未満の有機樹脂皮膜を、前記表面処理皮膜厚と合計した皮膜厚が５μｍ以下となるように形成することを特徴とする耐白錆性に優れた表面処理鋼板の製造方法。
【０１２４】
なお、上述した表面処理皮膜はめっき鋼板の片面、両面のいずれに形成してもよく、めっき鋼板表裏面の皮膜形態の組み合わせとしては、例えば、単層皮膜（表面処理皮膜）／無処理、二層皮膜（表面処理皮膜＋有機樹脂皮膜）／無処理、単層皮膜（表面処理皮膜）／二層皮膜（表面処理皮膜＋有機樹脂皮膜）、二層皮膜（表面処理皮膜＋有機樹脂皮膜）／二層皮膜（表面処理皮膜＋有機樹脂皮膜）など、任意の形態とすることができる。
【０１２５】
【実施例】
[実施例１]
表面処理組成物用の樹脂組成物として表２に示す水分散性樹脂を用い、これにシランカップリング剤（表３）、リン酸またはヘキサフルオロ金属酸（表４）、水溶性リン酸塩（表５）、非クロム系防錆添加剤（表６）、固形潤滑剤（表７）を適宜配合し、塗料用分散機（サンドグラインダー）を用いて所定時間攪拌し、表面処理組成物を調製した。
【０１２６】
冷延鋼板をベースとした家電、建材、自動車部品用のめっき鋼板である、表１に示すめっき鋼板を処理原板として用いた。なお、鋼板の板厚は評価の目的に応じて所定の板厚のものを採用した。このめっき鋼板の表面をアルカリ脱脂処理、水洗乾燥した後、上記表面処理組成物をロールコーターにより塗布し、各種温度で加熱乾燥した。皮膜の膜厚は、表面処理組成物の固形分（加熱残分）または塗布条件（ロールの圧下力、回転速度など）により調整した。
得られた表面処理鋼板の皮膜組成と品質性能（皮膜外観、耐白錆性、導電性、塗料密着性）を評価した結果を表８〜表１９に示す。なお、品質性能の評価は以下のようにして行った。
【０１２７】
（１）皮膜外観
各サンプルについて、皮膜外観の均一性（ムラの有り無し）を目視で評価した。評価基準は以下の通りである。
○ ：ムラが全く無い均一な外観
△ ：ムラが若干目立つ外観
× ：ムラが目立つ外観
（２）耐白錆性
各サンプルについて、塩水噴霧試験（ＪＩＳ−Ｚ−２３７１）を施し、１２０時間経過後の白錆面積率で評価した。評価基準は以下の通りである。
◎ ：白錆面積率５％未満
○ ：白錆面積率５％以上、１０％未満
○−：白錆面積率１０％以上、２５％未満
△ ：白錆面積率２５％以上、５０％未満
× ：白錆面積率５０％以上
【０１２８】
（３）導電性
ＪＩＳ Ｃ ２５５０により層間絶縁抵抗値を測定した。評価基準は以下の通りである。
○ ：３Ω・ｃｍ^２／枚未満
△ ：３〜５Ω・ｃｍ^２／枚
× ：５Ω・ｃｍ^２／枚超え
（４）塗料密着性
各サンプルについて、メラミン系の焼付塗料を塗装（膜厚３０μｍ）した後、沸水中に２時間浸漬し、直ちに碁盤目（１０×１０個，１ｍｍ間隔）のカットを入れて接着テープによる貼着・剥離を行い、塗膜の剥離面積率を測定した。評価基準は以下の通りである。
◎：剥離なし
○：剥離面積率５％未満
△：剥離面積率５％以上、２０％未満
×：剥離面積率２０％以上
【０１２９】
【表１】

【０１３０】
【表２】

【０１３１】
【表３】

【０１３２】
【表４】

【０１３３】
【表５】

【０１３４】
【表６】

【０１３５】
【表７】

【０１３６】
なお、表８〜表１９中に記載の＊１〜＊８は以下の内容を指す。
＊１：表１に記載のＮｏ．(めっき鋼板）
＊２：表２に記載のＮｏ．(水分散性樹脂）
＊３：表３に記載のＮｏ．(シランカップリング剤）
＊４：表４に記載のＮｏ．(リン酸および／またはヘキサフルオロ金属酸)
＊５：表５に記載のＮｏ．(水溶性リン酸塩)
＊６：表６に記載のＮｏ．(防錆添加剤)
＊７：表７に記載のＮｏ．(固形潤滑剤)
＊８：水分散性樹脂および／または水溶性樹脂の固形分１００重量部に対する重量部
【０１３７】
【表８】

【０１３８】
【表９】

【０１３９】
【表１０】

【０１４０】
【表１１】

【０１４１】
【表１２】

【０１４２】
【表１３】

【０１４３】
【表１４】

【０１４４】
【表１５】

【０１４５】
【表１６】

【０１４６】
【表１７】

【０１４７】
【表１８】

【０１４８】
【表１９】

【０１４９】
[実施例２]
表面処理組成物用の樹脂組成物として表２０に示す水性エポキシ樹脂分散液を用い、これにシランカップリング剤（表３）、リン酸またはヘキサフルオロ金属酸（表４）、水溶性リン酸塩（表２１）、非クロム系防錆添加剤（表６）、固形潤滑剤（表７）を適宜配合し、さらにアンモニア水、硝酸、酢酸、硫酸、リン酸、ヘキサフルオロ金属酸等でｐＨを０．５〜６に調整した後、塗料用分散機（サンドグラインダー）を用いて所定時間撹拌し、表面処理組成物を調製した。
【０１５０】
冷延鋼板をベースとした家電、建材、自動車部品用のめっき鋼板である、表１に示すめっき鋼板を処理原板として用いた。なお、鋼板の板厚は評価の目的に応じて所定の板厚のものを採用した。このめっき鋼板の表面をアルカリ脱脂処理、水洗乾燥した後、上記表面処理組成物をロールコーターにより塗布し、各種温度で加熱乾燥した。皮膜の膜厚は、表面処理組成物の固形分（加熱残分）または塗布条件（ロールの圧下力、回転速度など）により調整した。
得られた表面処理鋼板の皮膜組成と品質性能（皮膜外観、耐白錆性、導電性、塗料密着性）を評価した結果を表２２〜表３３に示す。なお、品質性能の評価は[実施例１]と同様にして行ったが、耐白錆性については、１６８時間経過後の白錆面積率で評価した。
【０１５１】
表２０に示す水性エポキシ樹脂分散液の製造例を以下に示す。
・ポリアルキレングリコール変性エポキシ樹脂の製造
製造例１
温度計、撹拌機、冷却管を備えたガラス製４ツ口フラスコに、数平均分子量４０００のポリエチレングリコール１６８８ｇとメチルエチルケトン５３９ｇ加え、６０℃で撹拌混合し均一透明になった後、トリレンジイソシアネート１７１ｇを加え、２時間反応させた後、エピコート８３４Ｘ９０（エポキシ樹脂，シェルジャパン社製、エポキシ当量２５０）１１２１ｇ、ジエチレングリコーリエチルエーテル６６ｇおよび１％ジブチルチンジラウレート溶液１．１gを添加し、さらに２時間反応させた。その後８０℃まで昇温し、３時間反応させてイソシアネート価が０．６以下になったことを確認した。その後９０℃まで昇温し、減圧蒸留により固形分濃度が８１．７％になるまでメチルエチルケトンを除去した。除去後、プロピレングリコールモノメチルエーテル６５９ｇ、脱イオン水２７０ｇを加えて希釈し、固形分濃度７６％のポリアルキレングリコール変性エポキシ樹脂溶液Ａ１を得た。
【０１５２】
・水性エポキシ樹脂分散液の製造
製造例２
ＥＰ１００４（エポキシ樹脂，油化シェルエポキシ社製，エポキシ当量１０００）２０２９ｇとプロピレングリコールモノブチルエーテル６９７ｇを四つ口フラスコに仕込み、１１０℃まで昇温して１時間で完全にエポキシ樹脂を溶解した。このものに、製造例１で得たポリアルキレングリコール変性エポキシ樹脂溶液Ａ１を１１８０ｇおよび３−アミノ−１，２，４−トリアゾール（分子量８４）３１１．７ｇ加えて１００℃で５時間反応させた後、プロピレングリコールモノブチルエーテル７１９．６ｇを加えて樹脂溶液Ｄ１を得た。
上記樹脂溶液Ｄ１を２５７．６ｇにＭＦ−Ｋ６０Ｘ（イソシアネート硬化剤，旭化成工業社製）５０ｇおよびＳｃａｔ２４（硬化触媒）０．３ｇを混合し、よく攪拌した後、水６９２．１ｇを少しずつ滴下・混合撹拌し、水性エポキシ樹脂分散液Ｅ１を得た。
【０１５３】
製造例３（ヒドラジン誘導体を含有しない水性エポキシ樹脂分散液）
ＥＰ１００４（エポキシ樹脂，油化シェルエポキシ社製，エポキシ当量１０００）２０２９ｇとプロピレングリコールモノブチルエーテル６９７ｇを四つ口フラスコに仕込み、１１０℃まで昇温して１時間で完全にエポキシ樹脂を溶解した。このものに、製造例１で得たポリアルキレングリコール変性エポキシ樹脂溶液Ａ１を１１８０ｇおよびプロピレングリコールモノブチルエーテル５２７．０ｇを加えて樹脂溶液Ｄ２を得た。
上記樹脂溶液Ｄ２を２５７．６ｇにＭＦ−Ｋ６０Ｘ（イソシアネート硬化剤，旭化成工業社製）５０ｇ及びＳｃａｔ２４（硬化触媒）０．３ｇを混合しよく攪拌した後、水６９２．１ｇを少しずつ滴下・混合撹拌し、水性エポキシ樹脂分散液Ｅ２を得た。
【０１５４】
【表２０】

【０１５５】
【表２１】

【０１５６】
なお、表２２〜表３３中に記載の＊１〜＊８は以下の内容を指す。
＊１：表１に記載のＮｏ．(めっき鋼板)
＊２：表２０に記載のＮｏ．(水分散性樹脂）
＊３：表３に記載のＮｏ．(シランカップリング剤）
＊４：表４に記載のＮｏ．(リン酸および／またはヘキサフルオロ金属酸)
＊５：表２１に記載のＮｏ．(水溶性リン酸塩)
＊６：表６に記載のＮｏ．(防錆添加剤)
＊７：表７に記載のＮｏ．(固形潤滑剤)
＊８：水分散性樹脂の固形分１００重量部に対する重量部
【０１５７】
【表２２】

【０１５８】
【表２３】

【０１５９】
【表２４】

【０１６０】
【表２５】

【０１６１】
【表２６】

【０１６２】
【表２７】

【０１６３】
【表２８】

【０１６４】
【表２９】

【０１６５】
【表３０】

【０１６６】
【表３１】

【０１６７】
【表３２】

【０１６８】
【表３３】

【０１７７】
【発明の効果】
以上述べたように本発明の表面処理鋼板は、皮膜中にクロムを含まないにもかかわらず非常に優れた耐食性を有し、また皮膜外観や塗料密着性についても優れた特性を有している。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface-treated steel sheet that is most suitable for use in automobiles, home appliances, and building materials, and particularly relates to an environment-adaptive surface-treated steel sheet that does not contain chromium at all during the production of the surface-treated steel sheet and the surface-treated film, and a method for producing the same It is.
[0002]
[Prior art]
Conventionally, steel plates for home appliances, steel plates for building materials, and steel plates for automobiles have been used for the purpose of improving corrosion resistance (white rust resistance, red rust resistance) on the surface of galvanized steel sheets or aluminum-based galvanized steel sheets. Steel plates subjected to chromate treatment with a treatment liquid containing chromic acid or a salt thereof as a main component are widely used. This chromate treatment is an economical treatment method that has excellent corrosion resistance and can be performed relatively easily.
[0003]
Chromate treatment uses hexavalent chromium, a pollution-controlling substance, but this hexavalent chromium is treated in a closed system in the treatment process, completely reduced and recovered, and not released into nature. Since the elution of chromium from the chromate film can be made almost zero by the sealing action of the organic film, the environment and the human body are not substantially contaminated by hexavalent chromium. However, due to recent global environmental problems, there is a growing trend to voluntarily reduce the use of heavy metals including hexavalent chromium. In addition, in order not to pollute the environment when the shredder dust of discarded products is dumped, there has been a movement to minimize or reduce the amount of heavy metals contained in the product.
[0004]
For this reason, in order to prevent the occurrence of white rust in galvanized steel sheets, many treatment techniques that do not rely on chromate treatment, so-called chromium-free techniques, have been proposed. For example, there is a method of forming a thin film by a method such as immersion, coating, or electrolytic treatment using an inorganic compound, an organic compound, an organic polymer material, or a solution combining these.
[0005]
Specifically, the following methods can be mentioned.
 (1) A method of forming a film by immersing or applying a treatment liquid in a treatment liquid containing a polyhydric phenol carboxylic acid such as tannic acid and a silane coupling agent (for example, Japanese Patent Laid-Open No. 7-216268, patent No. 2968959)
 (2) A method of forming a film using a treatment liquid in which an organic resin is mixed with a polyhydric phenol carboxylic acid or phosphoric acid compound such as tannic acid (for example, JP-A-8-325760 and JP-A-2000-34578) JP, 2000-199076, JP, 2000-248380, JP)
 (3) A method of applying a treatment liquid containing an organic resin and a silane coupling agent (for example, JP-A-10-80664)
[0006]
[Problems to be solved by the invention]
As the method of (1), there is a method of treating with an aqueous solution containing a polyhydric phenol carboxylic acid and a silane coupling agent, and further metal ions, one of which is disclosed in JP-A-7-216268. Is mentioned. However, this treatment method has a drawback that satisfactory adhesion cannot be obtained although good adhesion can be obtained.
[0007]
As the method (2), for example, Japanese Patent Application Laid-Open No. 8-325760 discloses a method in which treatment is performed with a treatment liquid in which a polyhydric phenol carboxylic acid, an organic resin, and metal ions are blended. Japanese Patent Application Laid-Open No. 2000-34578 discloses a method of dipping in a treatment liquid to which an organic resin and a phosphoric acid compound are added or applying a treatment liquid and then drying. However, although the protective film formed by these treatment liquids contributes to the improvement of the corrosion resistance to some extent, the high degree of corrosion resistance as in the case of the chromate treatment cannot be obtained.
[0008]
Further, as the method of (3) above, JP-A-10-80664 discloses a method for forming a film by applying a treatment liquid containing an organic resin and a silane coupling agent. In the liquid, the silane coupling agent cannot exert a sufficient effect on the inert metal surface, and thus the obtained adhesion and corrosion resistance are not sufficient.
Accordingly, an object of the present invention is to solve such problems of the prior art and provide a surface-treated steel sheet that does not contain heavy metals such as chromium in the surface-treated film and that provides excellent corrosion resistance.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present inventors have conducted the following investigation on the principle of corrosion inhibition for inhibiting corrosion of the plated steel sheet.
The corrosion of the zinc-based plated steel sheet on which the surface treatment film is formed proceeds in the following process.
 (1) Corrosion factors (oxygen, water, chlorine ions, etc.) permeate into the surface treatment film and diffuse to the plating film / surface treatment film interface.
 (2) Zinc dissolves by the following oxidation-reduction reaction at the plating film / surface treatment film interface.
Cathode reaction: 2H₂O + O₂+ 4e⁻ → 4OH⁻
Anode reaction: 2Zn → 2Zn²⁺+ 4e⁻
[0010]
  Therefore, to improve the corrosion resistance of the galvanized steel sheet, it is essential to suppress the progress of both reactions (1) and (2).
( i ) Advanced barrier layer that acts as a diffusion barrier for corrosion factors (mainly acts to suppress the cathode reaction)
(ii) Reaction layer with plating metal that inactivates the plating layer (mainly acts to suppress the anode reaction)
It is most effective to have a film configuration that has a self-repairing action when a defect occurs in the reaction layer.
[0011]
  The inventor of the present invention does not form such a film structure by a single coating, but a double-layer film formed by coating the barrier layer forming component and the reaction layer forming component separately as in the prior art. Realize in the layer coating, specifically, above the coating( i )Barrier ofLayer, Above the coating(ii)Reaction ofLayerConfigure eachByIt has been found that a remarkable effect of improving corrosion resistance can be obtained by these synergistic effects. When such a single-layer coating is defined as a pseudo-two-layer coating, the barrier layer and the reaction layer constituting the pseudo-two-layer coating are between the two-layer coating formed by the conventional double coating. There is no clear interface. On the contrary, it is considered that a high degree of corrosion resistance improvement effect that cannot be obtained by the conventional single layer coating can be exhibited by making the both compositions in a gradient composition.
[0012]
As a result of intensive studies by the present inventors, the pseudo two-layer coating as described above is a reaction product of an epoxy group-containing resin and an active hydrogen-containing compound, and a part or all of the active hydrogen-containing compound is active. A surface treatment composition in which a silane coupling agent and a specific acid component (phosphoric acid and / or hexafluorometal acid) are blended with a water-dispersible resin or a water-soluble resin that is a hydrazine derivative having hydrogen is used as a zinc-based plated steel sheet or It was found that it was obtained by applying to the surface of an aluminum-based plated steel sheet and drying.
[0013]
Silane coupling agents have been known to have an effect of improving the adhesion between inorganic compounds and organic compounds, and can improve the adhesion between the plating metal and the water-dispersible resin or water-soluble resin. Is possible. In contrast to such known effects of the silane coupling agent, in the present invention, the acid component contained in the surface treatment composition activates the plating film surface by etching, and the silane coupling agent is activated by this activated plating. It is considered that extremely excellent adhesion between the plating metal and the film-forming resin can be obtained by chemically bonding with both the metal and the film-forming resin. That is, by adding a silane coupling agent and a specific acid component to the surface treatment composition, the adhesion between the plating metal and the film-forming resin is markedly greater than when the silane coupling agent is added alone. This is considered to contribute to the improvement of corrosion resistance.
[0014]
In the present invention, the mechanism by which the pseudo-bilayer film having the above-described film configuration is formed is not necessarily clear, but the reaction between the acid component in the surface treatment composition and the plating film surface may be involved in the film formation. is there. On the other hand, the following actions involving a silane coupling agent are also conceivable. That is, since the silane coupling agent hydrolyzed in an aqueous solution has a silanol group (Si—OH), the hydrogen bonding adsorption action of the silane coupling agent on the surface of the plating metal activated by the acid component is promoted. When the silane coupling agent is concentrated on the metal surface and then dried, a dehydration condensation reaction takes place and a strong chemical bond is formed, thereby forming a reaction layer at the bottom of the film and a water-dispersible resin concentrated at the top of the film. There is also a possibility that the barrier layer is formed by a water-soluble resin. In addition, there is a possibility that the above-described action occurs in a composite manner. In addition, in the film formation process as described above, it is considered that a reaction product (compound) between a dissolved plating metal such as zinc and an acid component is deposited in the film.
[0015]
  Although the anti-corrosion mechanism of such a pseudo two-layer coating is not necessarily clear,( i )By applying a hydrazine derivative to the epoxy group-containing resin as a barrier layer, a dense organic polymer film is formed, which inhibits the transmission of corrosion factors (oxygen, water, chlorine ions, etc.) and causes cathode corrosion Effectively suppressing the reaction, and the plating metal ions eluted by the corrosion reaction are trapped by the free hydrazine derivative in the film to form a stable insoluble chelate compound layer.(ii)The reaction layer inactivates the surface layer of the plating film and effectively suppresses the anode reaction that causes corrosion, and further, the precipitated compound precipitated in the film dissolves in the corrosive environment to dissolve the acid component (phosphate ion). Self-repairing action that captures metal ions such as zinc ions eluted from the plating film (bonds with metal ions to form insoluble compounds), and silane coupling. It is considered that a dense coating with high adhesion can be formed by binding the agent firmly to the plating metal surface activated by the acid component, suppressing dissolution of the plating metal, and binding to the film-forming resin. Thus, it is considered that extremely excellent corrosion resistance (white rust resistance) can be obtained by the combined anticorrosion mechanism.
[0016]
Further, it has been found that further excellent corrosion resistance can be obtained by incorporating a water-soluble phosphate and a non-chromium rust preventive additive into the surface treatment composition. In the same way as above, the poorly soluble film exhibits a barrier against corrosion factors, and the phosphate component captures the eluted plating metal ions, forming an insoluble compound with the plating metal ions. It is possible to do. Further, since the non-chromium rust preventive additive forms a protective film at the starting point of corrosion, further excellent anticorrosive performance can be obtained. In practice, these combined effects provide very good anticorrosion performance.
[0017]
  The present invention has been made based on such findings, and the features thereof are as follows.
[1] On the surface of zinc-plated steel sheet or aluminum-plated steel sheet,
  (A) A water-dispersible resin and / or water-soluble resin, which is a reaction product of an epoxy group-containing resin and an active hydrogen-containing compound, and a part or all of the active hydrogen-containing compound is a hydrazine derivative having active hydrogen Resin,
  (B) a silane coupling agent;
  (C) phosphoric acid and / or hexafluorometal acid
ContainsAnd the content of the silane coupling agent is 15 to 50 parts by weight with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resin, and the phosphoric acid and / or hexafluorometal acid content. Is 5 to 50 parts by weight with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resinA surface-treated steel sheet excellent in white rust resistance, characterized by having a surface-treated film having a film thickness of 0.02 to 5 μm formed by applying and drying a surface treatment composition.
[0018]
[2] the above [1] ofIn the surface-treated steel sheet, the surface treatment composition further contains a water-soluble phosphate in an amount of 0.1 to 60 parts by weight in a solid content with respect to 100 parts by weight of a water-dispersible resin and / or a solid content of the water-soluble resin. A surface-treated steel sheet with excellent white rust resistance.
[0019]
[3] the above [2] ofIn the surface-treated steel sheet, the surface treatment composition is a water-soluble phosphate as a cationic component and P₂O₅Component molar ratio [cation] / [P₂O₅Is 0.4 to 1.0, and contains a water-soluble phosphate having a cation species of one or more selected from Mn, Mg, Al, and Ni. Surface treated steel plate with excellent properties.
[Four] the above [1] ~ [3] ofIn any one of the surface-treated steel sheets, the surface treatment composition further contains a non-chromium rust preventive additive in a solid content of 0.1 to 100 parts by weight of a water-dispersible resin and / or a water-soluble resin. A surface-treated steel sheet excellent in white rust resistance, characterized by containing 50 parts by weight.
[0020]
[Five] the above [Four] ofIn the surface-treated steel sheet, the surface treatment composition contains one or more rust preventive additives selected from the following groups (e1) to (e5) as a non-chromium rust preventive additive. Surface-treated steel sheet with excellent white rust resistance.
(E1) Silicon oxide
(E 2 ) Calcium compounds
(E3) Insoluble phosphate compound
(E4) Molybdate compound
(E5) One or more organic compounds containing S atom selected from triazoles, thiols, thiadiazoles, thiazoles, thiurams
[6] the above [1] ~ [Five] ofIn any one of the surface-treated steel sheets, the surface treatment composition further contains a solid lubricant in a solid content of 1 to 50 parts by weight with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or the water-soluble resin. A surface-treated steel sheet with excellent white rust resistance.
[0021]
[7] the above [1] ~ [6] ofIn any surface-treated steel sheet, the surface treatment composition contains at least one silane coupling agent having an amino group as a reactive functional group as a silane coupling agent. Excellent surface-treated steel sheet.
[8] the above [1] ~ [7] ofIn any one of the surface-treated steel sheets, the surface treatment composition contains at least one hexafluorometal acid containing at least one element selected from Ti, Si, and Zr as the hexafluorometal acid. A surface-treated steel sheet with excellent white rust resistance.
[9] the above [Four] ~ [8] ofA surface-treated steel sheet excellent in white rust resistance, wherein the surface-treated composition contains calcium ion-exchanged silica as a non-chromium rust preventive additive.
[0022]
[Ten] the above [1] ~ [9] ofIn any one of the surface-treated steel sheets, the surface treatment composition contains a water-dispersible resin as the component (a), and the water-dispersible resin is a polyalkylene glycol having a number average molecular weight of 400 to 20000, a bisphenol type epoxy resin. A polyalkylene glycol-modified epoxy resin (A) obtained by reacting an active hydrogen-containing compound and a polyisocyanate compound, an epoxy group-containing resin (B) other than the polyalkylene glycol-modified epoxy resin (A), and active hydrogen A surface-treated steel sheet excellent in white rust resistance, characterized in that it is a water-based epoxy resin dispersion obtained by reacting with a hydrazine derivative (C).
[0023]
[11] the above [1] ~ [9]In any of the surface-treated steel sheets, the surface treatment composition contains a water-dispersible resin as the component (a), and the water-dispersible resin is a polyalkylene glycol having a number average molecular weight of 400 to 20000, a bisphenol type epoxy. A polyalkylene glycol-modified epoxy resin (A) obtained by reacting a resin, an active hydrogen-containing compound and a polyisocyanate compound; an epoxy group-containing resin (B) other than the polyalkylene glycol-modified epoxy resin (A); It is an aqueous epoxy resin dispersion obtained by reacting a hydrogen-containing hydrazine derivative (C) with an active hydrogen-containing compound (D) other than the hydrazine derivative (C). Excellent surface-treated steel sheet.
[0024]
[12] the above [Ten] Or [11] ofA surface-treated steel sheet excellent in white rust resistance, wherein the epoxy group-containing resin (B) is a bisphenol A type epoxy resin having a number average molecular weight of 1500 to 10000 and an epoxy equivalent of 150 to 5000.
[13] the above [Ten] ~ [12] ofThe surface-treated steel sheet excellent in white rust resistance, wherein the aqueous epoxy resin dispersion further contains a curing agent having a group that crosslinks with a hydroxyl group.
[0029]
[14] the above [1] ~ [13] ofAn organic resin film having a film thickness of 0.02 μm or more and less than 5 μm is further formed on an upper layer of the surface treatment film in which the film thickness of any one of the surface-treated steel sheets is 0.02 μm or more and less than 5 μm. A surface-treated steel sheet excellent in white rust resistance, characterized in that the total film thickness of the treated film is 5 μm or less.
[0030]
[15] the above [1] ~ [13] ofA method for producing any one of the surface-treated steel sheets,
  On the surface of zinc-based plated steel sheet or aluminum-based plated steel sheet,
  (A) A water-dispersible resin and / or water-soluble resin, which is a reaction product of an epoxy group-containing resin and an active hydrogen-containing compound, and a part or all of the active hydrogen-containing compound is a hydrazine derivative having active hydrogen Resin,
  (B) a silane coupling agent;
  (C) phosphoric acid and / or hexafluorometal acid
ContainsThe content of the silane coupling agent is 15 to 50 parts by weight with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resin, and the content of the phosphoric acid and / or hexafluorometal acid is 5 to 50 parts by weight with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resin,A surface treatment composition having a pH of 0.5 to 6 is applied and dried by heating at an ultimate plate temperature of 50 ° C. to 300 ° C. without washing with water to form a surface treatment film with a film thickness of 0.02 to 5 μm. A method for producing a surface-treated steel sheet excellent in white rust resistance, characterized by forming.
[16] the above [15] ofAn organic resin film having a film thickness of 0.02 μm or more and less than 5 μm is combined with the surface treatment film thickness on the upper surface of the surface treatment film having a film thickness of 0.02 μm or more and less than 5 μm obtained by the manufacturing method. A method for producing a surface-treated steel sheet having excellent white rust resistance, wherein the formed film thickness is 5 μm or less.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
The details of the present invention and the reasons for limitation will be described below.
Examples of the zinc-based plated steel sheet used as the base of the surface-treated steel sheet of the present invention include galvanized steel sheet, Zn-Ni alloy-plated steel sheet, Zn-Fe alloy-plated steel sheet (electroplated steel sheet and galvannealed steel sheet), Zn-Cr. Alloy-plated steel sheet, Zn-Mn alloy-plated steel sheet, Zn-Co alloy-plated steel sheet, Zn-Co-Cr alloy-plated steel sheet, Zn-Cr-Ni alloy-plated steel sheet, Zn-Cr-Fe alloy-plated steel sheet, Zn-Al alloy plating Steel plates (eg, Zn-5% Al alloy plated steel plates, Zn-55% Al alloy plated steel plates, etc.), Zn—Mg alloy plated steel plates, Zn—Al—Mg plated steel plates (eg, Zn-6% Al—3% Mg) Alloy-plated steel sheet, Zn-11% Al-3% Mg alloy-plated steel sheet), and metal oxides, polymers, etc. in the plating film of these plated steel sheets Diffusing the zinc-based composite-plated steel sheet (for example, Zn-SiO₂(Dispersed plated steel sheet) can be used.
[0032]
Moreover, the multilayer plating steel plate which plated two or more layers of the same kind or different kind among the above plating can also be used.
Moreover, as an aluminum system plated steel plate used as the base of the surface treatment steel plate of this invention, an aluminum plating steel plate, an Al-Si alloy plating steel plate, etc. can be used.
Moreover, as a plated steel plate, the steel plate surface may be previously plated with lightness such as Ni, and various plating as described above may be performed thereon.
As a plating method, any feasible method among an electrolytic method (electrolysis in an aqueous solution or electrolysis in a nonaqueous solvent), a melting method, and a gas phase method can be adopted.
Furthermore, for the purpose of preventing blackening of the plating, about 1 to 2000 ppm of trace elements of Ni, Co, and Fe are deposited in the plating film, or an alkaline aqueous solution or acid solution containing Ni, Co, Fe on the surface of the plating film. You may make it surface-treat with an aqueous solution and precipitate these elements.
[0033]
Next, the surface treatment film formed on the surface of the zinc-based plated steel sheet or the aluminum-based plated steel sheet and the surface treatment composition for forming the film will be described.
In the surface-treated steel sheet of the present invention, the surface treatment film formed on the surface of the zinc-based plated steel sheet or the aluminum-based plated steel sheet,
(A) A water-dispersible resin and / or water-soluble resin, which is a reaction product of an epoxy group-containing resin and an active hydrogen-containing compound, and a part or all of the active hydrogen-containing compound is a hydrazine derivative having active hydrogen Resin,
(B) a silane coupling agent;
(C) phosphoric acid and / or hexafluorometal acid
It is the surface treatment film | membrane formed by apply | coating the surface treatment composition containing this and drying. This surface treatment film does not contain Cr at all.
[0034]
First, the epoxy group-containing resin and the active hydrogen-containing compound that produce the water-dispersible resin or water-soluble resin as the component (a) will be described.
Examples of the epoxy group-containing resin include epoxy resins, modified epoxy resins, acrylic copolymer resins copolymerized with epoxy group-containing monomers, polybutadiene resins having epoxy groups, polyurethane resins having epoxy groups, and adducts of these resins Or a condensate can be used individually by 1 type or in mixture of 2 or more types.
[0035]
As the epoxy resin, polyphenols such as bisphenol A, bisphenol F, and novolac type phenol are reacted with epihalohydrin such as epichlorohydrin to introduce a glycidyl group, or polyphenols are further added to this glycidyl group introduction reaction product. An aromatic epoxy resin obtained by reacting with an aromatic epoxy resin; and further, an aliphatic epoxy resin, an alicyclic epoxy resin, etc., may be used alone or in combination of two or more. Can do. These epoxy resins preferably have a number average molecular weight of 1500 or more, particularly when film formation at low temperatures is required.
Examples of the modified epoxy resin include resins obtained by reacting various modifiers with an epoxy group or a hydroxyl group in the epoxy resin, such as an epoxy ester resin obtained by reacting a drying oil fatty acid; acrylic acid or methacrylic acid, etc. And an epoxy acrylate resin modified with a polymerizable unsaturated monomer component containing a urethane modified epoxy resin reacted with an isocyanate compound.
[0036]
As the acrylic copolymer resin copolymerized with the above epoxy group-containing monomer, an unsaturated monomer having an epoxy group and a polymerizable unsaturated monomer component essentially comprising an acrylic ester or a methacrylic ester are prepared by a solution polymerization method, emulsion weight. Examples of the polymerizable unsaturated monomer component include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-, and the like. C1-C24 alkyl ester of acrylic acid or methacrylic acid such as iso- or tert-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate ; Examples include C1-4 alkyl etherified products of phosphoric acid, methacrylic acid, styrene, vinyl toluene, acrylamide, acrylonitrile, N-methylol (meth) acrylamide, N-methylol (meth) acrylamide; N, N-diethylaminoethyl methacrylate, and the like. it can. Moreover, as an unsaturated monomer which has an epoxy group, if it has an epoxy group and a polymerizable unsaturated group, such as glycidyl methacrylate, glycidyl acrylate, and 3,4-epoxycyclohexyl-1-methyl (meth) acrylate, There is no particular limitation.
The acrylic copolymer resin may be a resin modified with a polyester resin, an epoxy resin, a phenol resin, or the like.
[0037]
Particularly preferred as the epoxy resin is a resin represented by the following chemical structural formula, which is a reaction product of bisphenol A and epiparohydrin, and is particularly suitable because of its excellent corrosion resistance.
[Chemical 1]

In said chemical structural formula, q is an integer of 0-50, Preferably it is an integer of 1-40, Most preferably, it is an integer of 2-20.
Such a bisphenol A type epoxy resin can be obtained by a production method widely known in the art.
[0038]
Examples of the active hydrogen-containing compound that reacts with the epoxy group of the epoxy group-containing resin include the following.
・ Hydrazine derivatives with active hydrogen
· Primary or secondary amine compounds with active hydrogen
・ Organic acids such as ammonia and carboxylic acids
・ Hydrogen halides such as hydrogen chloride
・ Alcohols and thiols
A quaternary chlorinating agent which is a mixture of a hydrazine derivative or a tertiary amine and an acid having no active hydrogen
In the present invention, one or more of these can be used, but in order to obtain excellent corrosion resistance, at least a part (preferably all) of the active hydrogen-containing compounds must be hydrazine derivatives having active hydrogen. is there.
[0039]
The following can be mentioned as a typical example of the amine compound which has the said activated hydrogen.
 (1) A primary amino group of an amine compound containing one secondary amino group and one or more primary amino groups, such as diethylenetriamine, hydroxyethylaminoethylamine, ethylaminoethylamine, and methylaminopropylamine, A compound modified with aldimine, ketimine, oxazoline or imidazoline by heating reaction with aldehyde or carboxylic acid at a temperature of about 100 to 230 ° C., for example;
 (2) Secondary monoamines such as diethylamine, diethanolamine, di-n- or -ios-propanolamine, N-methylethanolamine, N-ethylethanolamine;
[0040]
 (3) a secondary amine-containing compound obtained by adding a monoalkanolamine such as monoethanolamine and a dialkyl (meth) acrylamide by a Michael addition reaction;
 (4) Compounds obtained by modifying primary amine groups of alkanolamines such as monoethanolamine, neopentanolamine, 2-aminopropanol, 3-aminopropanol, 2-hydroxy-2 '(aminopropoxy) ethyl ether to ketimines;
[0041]
The quaternary chlorinating agent that can be used as a part of the active hydrogen-containing compound can react with an epoxy group because a hydrazine derivative or a tertiary amine that does not have an active hydrogen is not reactive with an epoxy group by itself. Therefore, it is a mixture with an acid. The quaternary chlorinating agent reacts with an epoxy group in the presence of water as necessary to form a quaternary salt with the epoxy group-containing resin. The acid used to obtain the quaternary chlorinating agent may be any of organic acids such as acetic acid and lactic acid, and inorganic acids such as hydrochloric acid. Examples of the hydrazine derivative having no active hydrogen used for obtaining a quaternary chlorinating agent include 3,6-dichloropyridazine, and examples of the tertiary amine include dimethylethanolamine, triethylamine, Examples include trimethylamine, triisopropylamine, and methyldiethanolamine.
[0042]
It is a hydrazine derivative having active hydrogen that exhibits the most useful and excellent corrosion resistance performance among the active hydrogen-containing compounds.
Specific examples of the hydrazine derivative having active hydrogen include the following.
(1) Carbohydrazide, propionic acid hydrazide, salicylic acid hydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, dodecanoic acid dihydrazide, isophthalic acid dihydrazide, thiocarbohydrazide, 4,4'-oxybisbenzenesulfonylhydrazide, polybenzophenacrylamide hydrazone Hydrazide compounds such as;
(2) Pyrazole compounds such as pyrazole, 3,5-dimethylpyrazole, 3-methyl-5-pyrazolone, 3-amino-5-methylpyrazole;
[0043]
(3) 1,2,4-triazole, 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 5-amino -3-mercapto-1,2,4-triazole, 2,3-dihydro-3-oxo-1,2,4-triazole, 1H-benzotriazole, 1-hydroxybenzotriazole (monohydrate), 6- Triazole compounds such as methyl-8-hydroxytriazolopyridazine, 6-phenyl-8-hydroxytriazolopyridazine, 5-hydroxy-7-methyl-1,3,8-triazaindolizine;
[0044]
(4) Tetrazole compounds such as 5-phenyl-1,2,3,4-tetrazole and 5-mercapto-1-phenyl-1,2,3,4-tetrazole;
(5) Thiadiazole compounds such as 5-amino-2-mercapto-1,3,4-thiadiazole and 2,5-dimercapto-1,3,4-thiadiazole;
(6) Maleic hydrazide, 6-methyl-3-pyridazone, 4,5-dichloro-3-pyridazone, 4,5-dibromo-3-pyridazone, 6-methyl-4,5-dihydro-3-pyridazone, etc. Pyridazine compounds;
Among these, pyrazole compounds and triazole compounds having a 5-membered or 6-membered ring structure and having a nitrogen atom in the ring structure are particularly suitable.
These hydrazine derivatives can be used individually by 1 type or in mixture of 2 or more types.
[0045]
The water-dispersible resin or water-soluble resin of the above (a), which is a reaction product of an epoxy group-containing resin and an active hydrogen-containing compound comprising a hydrazine derivative partly or entirely having active hydrogen, is an epoxy group-containing resin. The specific active hydrogen-containing compound can be obtained by reacting at 10 to 300 ° C, preferably 50 to 150 ° C for about 1 to 8 hours.
[0046]
This reaction may be performed by adding an organic solvent, and the type of the organic solvent to be used is not particularly limited. For example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, dibutyl ketone, cyclohexanone; ethanol, butanol, 2-ethylhexyl alcohol, benzyl alcohol, ethylene glycol, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether , Propylene glycol, propylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether and other alcohols and ethers containing hydroxyl groups; ethyl acetate, butyl acetate, ethylene glycol monobutyl ether acetate and other esters; toluene, xylene Aromatic hydrocarbons, etc. Indicates possible, it is possible to use one or more of these. Of these, ketone-based or ether-based solvents are particularly preferable from the viewpoints of solubility with an epoxy resin and film-forming properties.
[0047]
The compounding ratio of the epoxy group-containing resin and the active hydrogen-containing compound comprising a hydrazine derivative partly or entirely having active hydrogen is the ratio of the number of active hydrogen groups to the number of epoxy groups [number of active hydrogen groups / number of epoxy groups]. It is appropriate from the viewpoint of corrosion resistance, water dispersibility, etc. to be 0.01 to 10, more preferably 0.1 to 8, and still more preferably 0.2 to 4.
[0048]
The proportion of the hydrazine derivative having active hydrogen in the active hydrogen-containing compound is suitably 10 to 100 mol%, more preferably 30 to 100 mol%, and still more preferably 40 to 100 mol%. If the ratio of the hydrazine derivative having active hydrogen is less than 10 mol%, the surface treatment film cannot be provided with a sufficient rust prevention function, and the resulting rust prevention effect is obtained by simply mixing the film-forming organic resin and the hydrazine derivative. There is no big difference from the case.
In the present invention, the water-dispersible resin of the above (a), which is a reaction product of the epoxy group-containing resin obtained as described above and an active hydrogen-containing compound partly or entirely made of a hydrazine derivative having active hydrogen Or 1 type of water-soluble resin can be used individually or in mixture of 2 or more types.
[0049]
In the present invention, in order to form a dense barrier film, it is desirable to mix a curing agent in the resin composition and heat cure the film. The curing method for forming a film with the resin composition was selected from (1) a curing method using a urethanization reaction between isocyanate and a hydroxyl group in the base resin, and (2) melamine, urea, and benzoguanamine. Etherification reaction between an alkyl etherified amino resin obtained by reacting one or more methylol compounds obtained by reacting formaldehyde with one or more monovalent alcohols having 1 to 5 carbon atoms and a hydroxyl group in the base resin. However, it is particularly preferable to use a urethanization reaction between an isocyanate and a hydroxyl group in the base resin as a main reaction.
[0050]
The polyisocyanate compound used in the curing method (1) above is composed of an aliphatic, alicyclic (including heterocyclic) or aromatic isocyanate compound having at least two isocyanate groups in one molecule, or many of these compounds. It is a compound that has been partially reacted with a monohydric alcohol. Examples of such polyisocyanate compounds include the following.
[0051]
(1) m- or p-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate, o- or p-xylylene diisocyanate, hexamethylene diisocyanate, dimer acid diisocyanate, isophorone diisocyanate
(2) Compound (1) above or a mixture thereof and polyhydric alcohols (dihydric alcohols such as ethylene glycol and propylene glycol; trihydric alcohols such as glycerin and trimethylolpropane; tetrahydric alcohols such as pentaerythritol; A reaction product with a hexahydric alcohol such as sorbitol and dipentaerythritol), in which at least two isocyanates remain in one molecule
These polyisocyanate compounds can be used individually by 1 type or in mixture of 2 or more types.
[0052]
Examples of the protective agent (blocking agent) for the polyisocyanate compound include (1) aliphatic monoalcohols such as methanol, ethanol, propanol, butanol, octyl alcohol;
(2) Ethylene glycol and / or diethylene glycol monoethers, for example, monoethers such as methyl, ethyl, propyl (n-, iso), butyl (n-, iso, sec);
(3) Aromatic alcohols such as phenol and cresol;
(4) Oxime such as acetoxime and methyl ethyl ketone oxime;
A polyisocyanate compound that is stably protected at least at room temperature can be obtained by reacting one or more of these with the polyisocyanate compound.
[0053]
Such a polyisocyanate compound (a2) is a reaction product (a) of an epoxy group-containing resin and the specific active hydrogen-containing compound (that is, a water-dispersible resin and / or a water-soluble resin as a component of the above-mentioned (a)). (A) / (a2) = 95/5 to 55/45 (weight ratio of nonvolatile content), preferably (a) / (a2) = 90/10 to 65/35 It is suitable to mix | blend in the ratio. The polyisocyanate compound has water absorption, and if it is blended in excess of (a) / (a2) = 55/45, the adhesion of the surface treatment film is deteriorated. Furthermore, when top coating is performed on the surface-treated film, the unreacted polyisocyanate compound moves into the coating film, which causes inhibition of curing of the coating film and poor adhesion. From such a viewpoint, the blending amount of the polyisocyanate compound (a2) is preferably (a) / (a2) = 55/45 or less.
[0054]
The water-dispersible resin and / or water-soluble resin, which is a reaction product of the epoxy group-containing resin and the specific active hydrogen-containing compound, is sufficiently crosslinked by the addition of the crosslinking agent (curing agent) as described above. In order to further increase the low-temperature crosslinking property, it is desirable to use a known curing accelerating catalyst. Examples of the curing accelerating catalyst include N-ethylmorpholine, dibutyltin dilaurate, cobalt naphthenate, stannous chloride, zinc naphthenate, and bismuth nitrate.
For the purpose of slightly improving physical properties such as adhesion, a known resin such as acrylic, alkyd, or polyester can be mixed and used together with an epoxy group-containing resin.
[0055]
In order to disperse water or water-solubilize a reaction product of an epoxy group-containing resin and a specific active hydrogen-containing compound, for example, the following method can be employed.
(1) The epoxy group of the epoxy group-containing resin is reacted with an active hydrogen-containing compound dibasic acid or secondary amine, and neutralized with a neutralizer such as tertiary amine, acetic acid or phosphoric acid, and dispersed in water. Method
(2) A method in which water is dispersed using a modified epoxy resin (a3) obtained by reacting an epoxy resin with a terminal hydroxyl group-containing polyalkylene oxide such as polyethylene glycol or polypropylene glycol with an isocyanate.
(3) Method using both (1) and (2) above
[0056]
When the above methods (2) and (3) are employed, the reaction product (a) of the epoxy group-containing resin and the specific active hydrogen-containing compound (that is, the water-dispersible resin and the component (a) above) / Or water-soluble resin) and the modified epoxy resin (a3) are (a) / (a3) = 90 / 5-60 / 40 (weight ratio of non-volatile content), preferably (a) / (a3) = 80 / It is appropriate to blend at a ratio of 20 to 65/35. If the compounding ratio of the reaction product (a) exceeds (a) / (a3) = 90/5, good resin dispersibility cannot be obtained, and the resin particles become coarse and defects are formed during film formation. The performance is not obtained. On the other hand, when the blending ratio of the modified epoxy resin (a3) exceeds (a) / (a3) = 60/40, problems such as a decrease in corrosion resistance due to excessive hydrophilicity occur.
[0057]
In addition to the specific water-dispersible resin and / or water-soluble resin described above, other water-dispersible resins and / or water-soluble resins include, for example, acrylic resins, urethane resins, and polyester resins. You may mix | blend 1 type (s) or 2 or more types, such as resin, an epoxy-type resin, ethylene-type resin, an alkyd-type resin, a phenol resin, and an olefin resin, by about 15 mass% by the ratio in the total resin solid content.
[0058]
Further, as the water-dispersible resin as the component (a), a specific polyalkylene glycol-modified epoxy resin (A) and an epoxy group-containing resin (B) other than the polyalkylene glycol-modified epoxy resin (A), Use of an aqueous epoxy resin dispersion (X) obtained by reacting a hydrazine derivative (C) having active hydrogen with an active hydrogen-containing compound (D) other than the hydrazine derivative (C) if necessary. Thus, particularly excellent white rust resistance can be obtained.
[0059]
The polyalkylene glycol-modified epoxy resin (A) is obtained by reacting a polyalkylene glycol having a number average molecular weight of 400 to 20000, a bisphenol type epoxy resin, an active hydrogen-containing compound, and a polyisocyanate compound. .
As the polyalkylene glycol, for example, polyethylene glycol, polypropylene glycol, polybutylene glycol and the like can be used, and among them, polyethylene glycol is particularly preferable. The number average molecular weight of the polyalkylene glycol is suitably in the range of 400 to 20000, preferably 500 to 10,000, from the viewpoint of water dispersibility and storage properties of the resulting resin.
The bisphenol type epoxy resin is a bisphenol compound having at least one epoxy group in one molecule, and in particular, a bisphenol diester obtained by a condensation reaction between a bisphenol compound and an epihalohydrin (for example, epichlorohydrin). Glycidyl ether is preferable because a film excellent in flexibility and corrosion resistance can be easily obtained.
[0060]
Typical examples of bisphenol compounds that can be used for the preparation of bisphenol-type epoxy resins include bis (4-hydroxyphenyl) -2,2-propane, bis (4-hydroxyphenyl) -1,1-ethane, and bis. (4-hydroxyphenyl) -methane, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, bis (4-hydroxyphenyl) -1,1-isobutane, bis (4-hydroxy-3-t- Butylphenyl) -2,2-propane and the like. Of the epoxy resins prepared using such bisphenol-based compounds, bisphenol A type epoxy resins are particularly suitable in that a film excellent in flexibility and corrosion resistance can be obtained.
Further, the bisphenol type epoxy resin generally has a number average molecular weight of about 310 to 10,000, particularly preferably about 320 to 2,000, from the viewpoint of production stability during production of the polyalkylene glycol-modified epoxy resin. The epoxy equivalent is preferably in the range of about 155 to 5000, particularly desirably about 160 to 1000.
[0061]
The active hydrogen-containing compound is used for blocking isocyanate groups in the polyalkylene glycol-modified epoxy resin (A). Typical examples thereof include monohydric alcohols such as methanol, ethanol and diethylene glycol monobutyl ether; monovalent carboxylic acids such as acetic acid and propionic acid; monovalent thiols such as ethyl mercaptan. Other blocking agents (active hydrogen-containing compounds) include secondary amines such as diethylamine; one secondary amino group or hydroxyl group such as diethylenetriamine and monoethanolamine and one or more primary groups. A compound in which the primary amino group of an amine compound containing an amino group is modified to aldimine, ketimine, oxazoline or imidazoline by heating reaction with a ketone, aldehyde or carboxylic acid at a temperature of, for example, 100 to 230 ° C .; methyl ethyl ketoxime Oximes such as, phenols such as phenol and nonylphenol, and the like. These compounds generally have a number average molecular weight in the range of 30 to 2000, particularly preferably 30 to 200.
[0062]
The polyisocyanate compound is a compound having 2 or more, preferably 2 or 3 isocyanate groups in one molecule, and those generally used for the production of polyurethane resins can be used in the same manner. Such polyisocyanate compounds include aliphatic, alicyclic and aromatic polyisocyanate compounds. Representative examples include aliphatic polyisocyanate compounds such as hexamethylene diisocyanate (HMDI), HMDI biuret compound, HMDI isocyanurate compound; isophorone diisocyanate (IPDI), IPDI biuret compound, IPDI isocyanurate compound, Examples thereof include alicyclic polyisocyanate compounds such as hydrogenated xylylene diisocyanate and hydrogenated 4,4′-diphenylmethane diisocyanate; aromatic polyisocyanate compounds such as tolylene diisocyanate and xylylene diisocyanate.
[0063]
In general, the blending ratio of each component during the production of the polyalkylene glycol-modified epoxy resin (A) is suitably in the following range.
That is, the equivalent ratio of the hydroxyl group of the polyalkylene glycol to the isocyanate group of the polyisocyanate compound is 1 / 1.2 to 1/10, preferably 1 / 1.5 to 1/5, particularly preferably 1 / 1.5 to A value of 1/3 is appropriate. The equivalent ratio of the hydroxyl group of the active hydrogen-containing compound to the isocyanate group of the polyisocyanate compound is 1/2 to 1/100, preferably 1/3 to 1/50, particularly preferably 1/3 to 1/20. Is appropriate. The equivalent ratio of the total amount of hydroxyl groups of the polyalkylene glycol, the bisphenol type epoxy resin and the active hydrogen-containing compound to the isocyanate group of the polyisocyanate compound is 1 / 1.5 or less, preferably 1 / 0.1 to 1/1. .5, particularly preferably 1 / 0.1 to 1 / 1.1.
[0064]
The reaction of the polyalkylene glycol, the bisphenol type epoxy resin, the active hydrogen-containing compound and the polyisocyanate compound can be performed by a known method.
The polyalkylene glycol-modified epoxy resin (A) obtained above, an epoxy group-containing resin (B) other than the polyalkylene glycol-modified epoxy resin (A), a hydrazine derivative (C) having active hydrogen, and further necessary Accordingly, by reacting with an active hydrogen-containing compound (D) other than this hydrazine derivative (C), an aqueous epoxy resin dispersion (X that can be easily dispersed in water and has good adhesion to the material) ) Can be obtained.
[0065]
As the epoxy group-containing resin (B) other than the polyalkylene glycol-modified epoxy resin (A), a glycidyl group is introduced by reacting polyphenols such as bisphenol A, bisphenol F, and novolac phenol with an epihalohydrin such as epichlorohydrin. Or an aromatic epoxy resin obtained by further reacting this glycidyl group-introduced reaction product with a polyphenol to increase the molecular weight; and further, an aliphatic epoxy resin, an alicyclic epoxy resin, etc. One kind can be used alone, or two or more kinds can be mixed and used. These epoxy resins preferably have a number average molecular weight of 1500 or more, particularly when film formation at low temperatures is required.
Examples of the epoxy group-containing resin (B) include resins obtained by reacting various modifiers with epoxy groups or hydroxyl groups in the epoxy group-containing resin. For example, epoxy ester resins obtained by reacting a dry oil fatty acid. An epoxy acrylate resin modified with a polymerizable unsaturated monomer component containing acrylic acid or methacrylic acid; a urethane-modified epoxy resin reacted with an isocyanate compound;
[0066]
Further, as the epoxy group-containing resin (B), an unsaturated monomer having an epoxy group and a polymerizable unsaturated monomer component essentially comprising an acrylic ester or a methacrylic ester are used as a solution polymerization method, emulsion polymerization method or suspension polymerization method. An acrylic copolymer resin copolymerized with an epoxy group-containing monomer synthesized by a method such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl ( Acrylic acid or methacrylic acid such as (meth) acrylate, n-, iso- or tert-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate Of C1-C24 Alkyl ester; acrylic acid, methacrylic acid, styrene, vinyl toluene, acrylamide, acrylonitrile, N-methylol (meth) acrylamide, C1-4 alkyl etherified product of N-methylol (meth) acrylamide; N, N-diethylaminoethyl methacrylate, etc. Can be mentioned. Moreover, as an unsaturated monomer which has an epoxy group, if it has an epoxy group and a polymerizable unsaturated group, such as glycidyl methacrylate, glycidyl acrylate, and 3,4 epoxy cyclohexyl-1-methyl (meth) acrylate, It is not limited.
The acrylic copolymer resin may be a resin modified with a polyester resin, an epoxy resin, a phenol resin, or the like.
[0067]
Particularly preferred as the epoxy group-containing resin (B) is a resin represented by the following chemical structural formula, which is a reaction product of bisphenol A and epiparohydrin, and is particularly suitable because of its excellent corrosion resistance.
[Chemical 2]

In said chemical structural formula, q is an integer of 0-50, Preferably it is an integer of 1-40, Most preferably, it is an integer of 2-20.
Such a bisphenol A type epoxy resin can be obtained by a production method widely known in the art.
[0068]
Examples of the active hydrogen-containing compound that reacts with the epoxy group of the epoxy group-containing resin (B) include the following, and details thereof are as described above.
・ Hydrazine derivatives with active hydrogen
.Primary or secondary amine compounds having active hydrogen
・ Organic acids such as ammonia and carboxylic acids
・ Hydrogen halides such as hydrogen chloride
・ Alcohols and thiols
· A quaternary chlorinating agent which is a mixture of a hydrazine derivative or a tertiary amine and an acid having no active hydrogen
In preparing the aqueous epoxy resin dispersion (X), one or more of these can be used, but in order to obtain excellent corrosion resistance, at least a part (preferably all) of the active hydrogen-containing compound is used. Needs to be a hydrazine derivative having active hydrogen. That is, among these, a hydrazine derivative (C) having active hydrogen is an essential component, and an active hydrogen-containing compound (D) other than the hydrazine derivative (C) is used as necessary.
[0069]
A polyalkylene glycol-modified epoxy resin (A) as described above, an epoxy group-containing resin (B) other than the polyalkylene glycol-modified epoxy resin (A), a hydrazine derivative (C) having active hydrogen, and further necessary The active hydrogen-containing compound (D) other than the hydrazine derivative (C) is preferably reacted at a temperature of 10 to 300 ° C., more preferably 50 to 150 ° C. for about 1 to 8 hours. By dispersing the resin in water, the above-described aqueous epoxy resin dispersion (X) can be obtained.
[0070]
The above reaction may be performed by adding an organic solvent, and the type of the organic solvent to be used is not particularly limited. For example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, dibutyl ketone, cyclohexanone; ethanol, butanol, 2-ethylhexyl alcohol, benzyl alcohol, ethylene glycol, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether , Propylene glycol, propylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether and other alcohols and ethers containing hydroxyl groups; ethyl acetate, butyl acetate, ethylene glycol monobutyl ether acetate and other esters; toluene, xylene Aromatic hydrocarbons, etc. Indicates possible, it is possible to use one or more of these. Of these, ketone-based or ether-based solvents are particularly preferable from the viewpoints of solubility with an epoxy resin, film formation, and the like.
[0071]
The blending ratio of the polyalkylene glycol-modified epoxy resin (A), the epoxy group-containing resin (B) other than the polyalkylene glycol-modified epoxy resin (A), and the hydrazine derivative (C) having active hydrogen is polyalkylene glycol-modified. The equivalent ratio of active hydrogen groups in the hydrazine derivative (C) to the epoxy groups in the epoxy resin (A) and the epoxy group-containing resin (B) is 0.01 to 10, preferably 0.1 to 8, and more preferably 0. 2 to 4 is appropriate from the viewpoints of corrosion resistance and water dispersibility of the resin.
Further, a part of the hydrazine derivative (C) having active hydrogen can be replaced with the active hydrogen-containing compound (D), but the replacement amount is 90 mol% or less, preferably 70 mol% or less, more preferably 10 to 10 mol%. It is suitable from the viewpoint of anticorrosion and adhesion to be in the range of 60 mol%.
[0072]
Moreover, in order to form a dense barrier film, it is desirable to mix a curing agent in the aqueous epoxy resin dispersion (X) and heat cure the film. The curing method for forming a film with the resin composition was selected from (1) a curing method using a urethanization reaction between isocyanate and a hydroxyl group in the base resin, and (2) melamine, urea, and benzoguanamine. Etherification reaction between an alkyl etherified amino resin obtained by reacting one or more methylol compounds obtained by reacting formaldehyde with one or more monovalent alcohols having 1 to 5 carbon atoms and a hydroxyl group in the base resin. However, it is particularly preferable to use a urethanization reaction between an isocyanate and a hydroxyl group in the base resin as a main reaction.
[0073]
The polyisocyanate compound as a curing agent that can be used in the curing method (1) is an aliphatic, alicyclic (including heterocyclic) or aromatic isocyanate compound having at least two isocyanate groups in one molecule. Or a compound obtained by partially reacting these compounds with a polyhydric alcohol. Specific examples of such polyisocyanate compounds are as described above, and one of these polyisocyanate compounds can be used alone or in admixture of two or more.
Moreover, the specific example of the protective agent (blocking agent) of a polyisocyanate compound is also as having mentioned previously, By making the said polyisocyanate compound react with the 1 type (s) or 2 or more types, it is stable at normal temperature at least. A polyisocyanate compound as a protected curing agent can be obtained.
[0074]
Such a polyisocyanate compound (a2) is obtained by reacting the components (A), (B) and (C) (and, if necessary, the component (D)) with the reaction product (a1) (that is, the above ( (a1) / (a2) = 95/5 to 55/45 (mass ratio of non-volatile content), preferably (a1) / (a2) It is appropriate to blend at a ratio of 90/10 to 65/35. The polyisocyanate compound has water absorption, and if it is blended in excess of (a1) / (a2) = 55/45, the adhesion of the surface treatment film is deteriorated. Furthermore, when top coating is performed on the surface-treated film, the unreacted polyisocyanate compound moves into the coating film, which causes inhibition of curing of the coating film and poor adhesion. From such a viewpoint, the blending amount of the polyisocyanate compound (a2) is preferably (a1) / (a2) = 55/45 or less.
[0075]
The water-dispersible resin that is a reaction product of the components (A), (B), and (C) (and, if necessary, the component (D)) is a crosslinking agent (curing agent) as described above. ) Is sufficiently crosslinked, but in order to further increase the low-temperature crosslinking property, it is desirable to use a known curing accelerating catalyst. Examples of the curing accelerating catalyst include N-ethylmorpholine, dibutyltin dilaurate, cobalt naphthenate, stannous chloride, zinc naphthenate, and bismuth nitrate. For the purpose of slightly improving physical properties such as adhesion, a known resin such as acrylic, alkyd, and polyester can be mixed and used together with an epoxy group-containing resin.
[0076]
Next, the silane coupling agent which is the component (b) will be described.
Examples of the silane coupling agent include vinyl methoxy silane, vinyl ethoxy silane, vinyl trichloro silane, vinyl trimethoxy silane, vinyl triethoxy silane, β- (3,4 epoxy cyclohexyl) ethyl trimethoxy silane, and γ-glycid. Xylpropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ -Aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-me Tacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, p-styryltrimethoxysilane, γ -Acryloxypropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, γ-isocyanatopropyl Triethoxysilane, γ-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- (vinylbenzylamine) -β-aminoethyl-γ-aminopropyltri Etc. can be mentioned Tokishishiran, these one may be used alone or in combination of two or more.
[0077]
  In the present invention, the reason described above is considered to improve the white rust resistance by including a silane coupling agent together with a specific acid component in the surface treatment composition.
  Among the silane coupling agents, an amino group is particularly preferable as a reactive functional group from the viewpoint of having a functional group highly reactive with the water-dispersible resin and / or water-soluble resin of (a).DoSilane coupling agents are preferred. Examples of such silane coupling agents include N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ. -Aminopropyltrimexysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, etc., and specifically, KBM-903, KBE-903, KBM-603 manufactured by Shin-Etsu Chemical Co., Ltd. , KBE-602, KBE-603 (both are trade names), and the like.
[0078]
The amount of the silane coupling agent is 1 to 300 parts by weight, preferably 5 to 100 parts by weight, based on 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resin as the component (a). More preferably, the content is 15 to 50 parts by weight. When the amount of the silane coupling agent is less than 1 part by weight, the corrosion resistance is inferior. On the other hand, when the amount exceeds 300 parts by weight, a sufficient film cannot be formed, and therefore, adhesion and barrier properties with water-dispersible resin and / or water-soluble resin. The effect of increasing the resistance cannot be exhibited, and the corrosion resistance decreases.
[0079]
Next, phosphoric acid and / or hexafluorometal acid as the component (c) has an action of activating the plated metal surface by acting on the inactive plated metal surface. The phosphoric acid and hexafluorometal acid may be used alone or in combination.
The type of hexafluorometal acid is not particularly limited, but in particular hexafluorometal containing one or more elements selected from Ti, Si, Zr such as fluorinated titanate, fluorinated zirconate, and fluoric acid. Acids are preferred, and one or more of these can be used.
[0080]
The blending amount of phosphoric acid and / or hexafluorometal acid is 0.1 to 80 weight in total with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resin as the component (a). Part, preferably 1 to 60 parts by weight, more preferably 5 to 50 parts by weight. When the blending amount of phosphoric acid and / or hexafluorometal acid is less than 0.1 parts by weight, the corrosion resistance is inferior. On the other hand, when it exceeds 80 parts by weight, unevenness in appearance after film formation tends to occur.
[0081]
A water-soluble phosphate can be added to the surface treatment composition as necessary for the purpose of improving the corrosion resistance. As this water-soluble phosphate, for example, one or more metal salts such as orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, and metaphosphoric acid can be used. Moreover, you may add 1 or more types of the salt (for example, phytic acid, phytate, phosphonic acid, phosphonate, and these metal salts) of organic phosphoric acid. Of these, the primary phosphate is preferable from the viewpoint of the stability of the surface treatment composition.
There is no particular limitation on the form of phosphate present in the film, and it may be crystalline or non-crystalline. There are no particular restrictions on the ionicity and solubility of the phosphate in the film. The reason why the corrosion resistance is improved by adding the water-soluble phosphate is considered that the water-soluble phosphate forms a dense hardly soluble compound at the time of film formation.
[0082]
As described above, the silane coupling agent chemically bonds with both the activated plating metal and the film-forming resin, thereby providing excellent adhesion and corrosion resistance between the plating metal and the film-forming resin. There are unavoidably inactive portions on the metal surface, and such an inactive site hardly causes the above-mentioned chemical bond and cannot sufficiently exhibit the rust prevention effect. The water-soluble phosphate forms a dense hardly soluble compound at the time of film formation on such a plated film portion. That is, as the plating film is dissolved by the phosphate ions of the water-soluble phosphate, the pH increases at the plating film / surface treatment composition interface, resulting in the formation of a precipitate film of the water-soluble phosphate, which is corrosion resistant. It contributes to the improvement.
[0083]
  Also get particularly good corrosion resistanceThatFrom the viewpoint, Al, Mn, Ni and Mg are particularly desirable as the cationic species of the water-soluble phosphate, and it is preferable to use a water-soluble phosphate containing one or more elements selected from these. Examples of such water-soluble phosphates include primary aluminum phosphate, primary manganese phosphate, primary nickel phosphate, primary magnesium phosphate, and among these, primary aluminum phosphate is particularly preferable. Is most preferred. The cationic component and P₂O₅Component molar ratio [cation] / [P₂O₅] Is preferably 0.4 to 1.0. Molar ratio [cation] / [P₂O₅] Is less than 0.4, it is not preferable because soluble phosphoric acid impairs the poor solubility of the film and lowers the corrosion resistance. On the other hand, if it exceeds 1.0, the stability of the processing solution is remarkably lost, which is not preferable.
[0084]
The blending amount of the water-soluble phosphate is 0.1 to 60 parts by weight in solid content with respect to 100 parts by weight of solid content of the water-dispersible resin and / or water-soluble resin as the component (a). The amount is preferably 0.5 to 40 parts by weight, more preferably 1 to 30 parts by weight. If the blending amount of the water-soluble phosphate is less than 0.1 parts by weight, the effect of improving the corrosion resistance is not sufficient. It tends to occur.
[0085]
  A non-chromium rust preventive additive can be blended with the surface treatment composition as needed for the purpose of improving corrosion resistance. Particularly excellent anticorrosion performance (self-repairing property) can be obtained by blending such a non-chromium rust preventive additive into the surface treatment composition.
  In particular, it is preferable to use one or more selected from the following groups (e1) to (e5) as the non-chromium-based rust preventive additive.
(E1) Silicon oxide
(E 2 ) Calcium compounds
(E3) Insoluble phosphate compound
(E4) Molybdate compound
(E5) One or more organic compounds containing S atom selected from triazoles, thiols, thiadiazoles, thiazoles, thiurams
  The details of these (e1) to (e5) non-chromium rust preventive additives and the anticorrosion mechanism are as follows.
[0086]
First, as the component (e1), colloidal silica or dry silica, which is fine particle silica, can be used. From the viewpoint of corrosion resistance, calcium ion-exchanged silica in which calcium is bound to the surface is used. Is desirable.
As colloidal silica, for example, SNOWTEX O, 20, 30, 40, C, S (all trade names) manufactured by Nissan Chemical Co., Ltd. can be used, and as fumed silica, Nippon Aerosil ( AEROSIL R971, R812, R811, R974, R202, R805, 130, 200, 300, 300CF (all trade names) manufactured by Co., Ltd. can be used. As calcium ion exchange silica, W.R.Grace & Co. SHIELDEX C303, SHIELDEX AC3, SHIELDEX AC5 (all are trade names) manufactured by SHIELDEX, SHIELDEX, SHIELDEX SY710 (all are trade names) manufactured by Fuji Silysia Chemical Co., Ltd., etc. can be used. These silicas contribute to the production of dense and stable zinc corrosion products in a corrosive environment, and the corrosion products are formed densely on the plating surface, thereby suppressing the promotion of corrosion.
[0087]
  In addition, the above components (e2) and (e3) exhibit particularly excellent anticorrosion performance (self-repairing property) due to precipitation.
  The calcium compound as the component (e2) may be any of calcium oxide, calcium hydroxide, and calcium salt, and one or more of these can be used. In addition, there are no particular restrictions on the type of calcium salt. In addition to simple salts containing only calcium as a cation such as calcium silicate, calcium carbonate, and calcium phosphate, calcium and calcium such as calcium phosphate / zinc, calcium phosphate / magnesium, etc. Using double salts containing cations other thanGood. This (e2) component is preferentially dissolved in base metal over zinc and aluminum, which are plated metals, in a corrosive environment.⁻As a dense and sparingly soluble product, it blocks the defective part and suppresses the corrosion reaction. Moreover, when it mix | blends with the above silicas, a calcium ion adsorb | sucks to the surface and neutralizes a surface charge electrically and aggregates. As a result, a dense and sparingly soluble protective film is formed to block the corrosion and suppress the corrosion reaction.
[0088]
Further, as the hardly soluble phosphate compound (e3), a hardly soluble phosphate can be used. This sparingly soluble phosphate includes all types of salts such as simple salts and double salts. Moreover, there is no limitation in the metal cation which comprises it, and any metal cation, such as poorly soluble zinc phosphate, magnesium phosphate, calcium phosphate, aluminum phosphate, may be sufficient. Further, there is no limitation on the skeleton or the degree of condensation of phosphate ions, and any of normal salt, dihydrogen salt, monohydrogen salt or phosphite may be used. In addition, orthophosphate may be polyphosphate other than orthophosphate. Includes all condensed phosphates such as salts. This hardly soluble phosphorus compound is a metal plating zinc or aluminum eluted by corrosion, and forms a dense and hardly soluble protective film by complexing reaction with phosphate ions dissociated by hydrolysis, thereby blocking the origin of corrosion. Inhibits corrosion reactions.
[0089]
As the molybdate compound (e4), for example, molybdate can be used. The molybdate is not limited in its skeleton and degree of condensation, and examples thereof include orthomolybdate, paramolybdate, and metamolybdate. Moreover, all salts, such as a single salt and a double salt, are included, and phosphoric acid molybdate etc. are mentioned as a double salt. Molybdate compounds exhibit self-repairing properties due to the passivating effect. That is, by forming a dense oxide on the plating film surface together with dissolved oxygen in a corrosive environment, the corrosion starting point is blocked and the corrosion reaction is suppressed.
[0090]
Examples of the organic compound (e5) include the following. That is, as triazoles, 1,2,4-triazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 5-amino-3-mercapto-1,2 1,4-triazole, 1H-benzotriazole, etc., and as thiols, 1,3,5-triazine-2,4,6-trithiol, 2-mercaptobenzimidazole, etc., and as thiadiazoles, 5- Amino-2-mercapto-1,3,4-thiadiazole, 2,5-dimercapto-1,3,4-thiadiazole and the like, and as thiazoles, 2-N, N-diethylthiobenzothiazole, 2-mercapto Examples include benzothiazoles, and examples of thiurams include tetraethylthiuram disulfide. It is. These organic compounds exhibit self-repairing properties due to the adsorption effect. That is, zinc and aluminum eluted by corrosion are adsorbed on polar groups containing sulfur contained in these organic compounds to form an inert film, thereby blocking the corrosion starting point and suppressing the corrosion reaction.
[0091]
The blending amount of the non-chromium rust preventive additive is 0.1 to 50 parts by weight in solid content with respect to 100 parts by weight of solid content of the water-dispersible resin and / or water-soluble resin as the component (a). The amount is preferably 0.5 to 30 parts by weight, more preferably 1 to 20 parts by weight. If the blending amount of this non-chromium rust preventive additive is less than 0.1 part by weight, the effect of improving the corrosion resistance after alkali degreasing cannot be sufficiently obtained. In addition, the corrosion resistance is reduced, which is not preferable.
Two or more rust preventive additives (e1) to (e5) may be added in combination. In this case, since the inherent anticorrosive action is combined, higher corrosion resistance can be obtained. In particular, calcium ion-exchanged silica is used as the component (e1), and one or more of the components (e3), (e4), and (e5), particularly preferably the components (e3) to (e5). When all are added in combination, particularly excellent corrosion resistance is obtained.
[0092]
A solid lubricant can be blended with the surface treatment composition as necessary for the purpose of improving the processability of the film. Examples of the solid lubricant include the following.
 (1) Polyolefin wax, paraffin wax: For example, polyethylene wax, synthetic paraffin, natural paraffin, micro wax, chlorinated hydrocarbon, etc.
 (2) Fluorine resin fine particles: For example, polyfluoroethylene resin (polytetrafluoroethylene resin, etc.), polyvinyl fluoride resin, polyvinylidene fluoride resin, etc.
[0093]
In addition, fatty acid amide compounds (for example, stearic acid amide, palmitic acid amide, methylene bis stearoamide, ethylene bis stearamide, oleic acid amide, esylic acid amide, alkylene bis fatty acid amide), metal soaps (Eg, calcium stearate, lead stearate, calcium laurate, calcium palmitate, etc.), metal sulfides (eg, molybdenum disulfide, tungsten disulfide, etc.), graphite, graphite fluoride, boron nitride, polyalkylene glycol, alkali metal Sulfates may be used.
[0094]
Among the above solid lubricants, polyethylene wax and fluorine resin compounds (particularly, polytetrafluoroethylene resin fine particles) are particularly suitable. Polyethylene waxes include Hoechst's Seridust 9615A, 3715, 3620, 3910 (all trade names), Sanyo Chemical Co., Ltd. sun wax 131-P, 161-P (all trade names), Mitsui Petrochemical Chemipearl W-100, W-200, W-500, W-800, W-950 (all trade names) manufactured by Co., Ltd. can be used.
[0095]
Tetrafluoroethylene fine particles are particularly preferable as the fluororesin fine particles, and Lubron L-2 and L-5 (both are trade names) manufactured by Daikin Industries, Ltd., and MP1100 and 1200 (all trade names are manufactured by Mitsui DuPont). ), Full-on dispersions AD1, AD2, and full-on L140J, L150J, L155J (all trade names) manufactured by Asahi IC Fluoropolymers Co., Ltd. are suitable.
Among these, a particularly excellent lubricating effect can be expected by the combined use of polyolefin wax and tetrafluoroethylene.
The blending amount of the solid lubricant is 1 to 50 parts by weight, preferably 3 to 30 parts by weight, based on 100 parts by weight of the water-dispersible resin and / or water-soluble resin as the component (a). It is appropriate to use parts by weight. When the blending amount of the lubricant as the component (a) is less than 1 part by weight, the lubricating effect is poor, while when it exceeds 80 parts by weight, the paintability is lowered.
[0096]
Further, in the surface treatment film (and surface treatment composition), other oxide fine particles (for example, aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, antimony oxide, etc.), phosphomolybdate as corrosion inhibitors. (For example, aluminum phosphomolybdate), organic phosphoric acid and its salts (for example, phytic acid, phytate, phosphonic acid, phosphonate, and metal salts thereof, alkali metal salts, alkaline earth metal salts, etc.) 1 type, or 2 or more types, such as an organic inhibitor (For example, a hydrazine and its derivative (s), a thiol compound, a thiocarbamate etc.), can be added.
[0097]
Further, if necessary, in the surface treatment film (and surface treatment composition), as an additive, an organic coloring pigment (for example, condensed polycyclic organic pigment, phthalocyanine organic pigment, etc.), a coloring dye (for example, water-soluble) Azo metal dyes), inorganic pigments (eg, titanium oxide), conductive pigments (eg, metal powders such as zinc, aluminum, nickel, iron phosphide, antimony-doped tin oxide, etc.), coupling agents (eg, 1 type, or 2 or more types, such as a titanium coupling agent etc.) and a melamine cyanuric acid adduct.
[0098]
The surface treatment film formed by the surface treatment composition containing the above components has a dry film thickness of 0.02 to 5 μm, preferably 0.05 to 5 μm, more preferably 0.3 to 3 μm, and still more preferably 0. .5 to 2 μm. When the dry film thickness is less than 0.02 μm, the corrosion resistance is insufficient. On the other hand, when it exceeds 5 μm, the conductivity and workability deteriorate.
Moreover, an organic resin film can be formed as a second layer film on the upper layer of the surface treatment film described above. In this case, the thickness of the organic resin film that is the second layer film is 0.02 μm or more and less than 5 μm, preferably 0.05 μm or more and less than 5 μm, and the film thickness of the surface treatment film that is the first layer film is 0. It is preferable that the thickness is 0.02 μm or more and less than 5 μm, preferably 0.05 μm or more and less than 5 μm, and the total of both films does not exceed 5 μm.
[0111]
Next, the manufacturing method of the surface treatment steel plate of this invention is demonstrated.
In order to form the surface treatment film on the surface of the zinc-based plated steel sheet or the aluminum-based plated steel sheet, the surface treatment composition (treatment liquid) having the above-described composition is applied to the surface of the plated steel sheet so that the dry film thickness is in the above range. Apply and heat dry without rinsing.
The surface treatment composition (treatment liquid) is desirably adjusted to pH 0.5-6, preferably 2-4. If the pH of the surface treatment composition is less than 0.5, the reactivity of the treatment liquid is too strong, resulting in uneven appearance. On the other hand, if the pH exceeds 6, the reactivity of the treatment liquid becomes low, and the bonding between the plating metal and the film Becomes insufficient and the corrosion resistance decreases.
[0112]
As a method for forming the surface treatment composition on the surface of the plated steel sheet, any of a coating method, a dipping method, and a spray method may be used. As a coating treatment method, any method such as a roll coater (3-roll method, 2-roll method, etc.), a squeeze coater, or a die coater may be used. In addition, after the coating process or dipping process using a squeeze coater or the like, or the spray process, the coating amount can be adjusted, the appearance can be made uniform, and the film thickness can be made uniform by an air knife method or a roll drawing method.
[0113]
After coating the surface treatment composition, drying is performed without washing with water. As the heating and drying means, a dryer, a hot air furnace, a high frequency induction heating furnace, an infrared furnace or the like can be used. It is desirable that the heat drying is carried out in the range of 30 to 300 ° C., preferably 50 to 300 ° C., more preferably 60 to 250 ° C. at the ultimate plate temperature. If the heating and drying temperature is less than 30 ° C., a large amount of moisture remains in the film, resulting in insufficient corrosion resistance. Moreover, when it exceeds 300 degreeC, it will not only be uneconomical, but a defect will arise in a film | membrane and corrosion resistance will fall.
Further, when an organic resin film is formed as a second layer film on the upper layer of the surface treatment film formed as described above, the surface of the treatment composition for the second layer film has the above-described film thickness. It is applied to the treated film surface and dried by heating. Application | coating and heat drying of a treatment composition may be performed according to the method used for formation of the surface treatment film mentioned above.
[0114]
Therefore, the production method of the present invention and preferred embodiments thereof are as follows.
[1] On the surface of zinc-plated steel sheet or aluminum-plated steel sheet,
(A) A water-dispersible resin and / or water-soluble resin, which is a reaction product of an epoxy group-containing resin and an active hydrogen-containing compound, and a part or all of the active hydrogen-containing compound is a hydrazine derivative having active hydrogen Resin,
(B) a silane coupling agent;
(C) phosphoric acid and / or hexafluorometal acid
A surface treatment composition having a pH of 0.5 to 6 is applied and dried by heating at an ultimate plate temperature of 50 ° C. to 300 ° C. without washing with water, and the film thickness is 0.02 to 5 μm. A method for producing a surface-treated steel sheet having excellent white rust resistance, wherein a surface-treated film is formed.
[0115]
[2] In the production method of [1], the surface treatment composition comprises 1 to 300 parts by weight of a silane coupling agent based on 100 parts by weight of a solid component of the water-dispersible resin and / or water-soluble resin. Surface treatment with excellent white rust resistance characterized by containing 0.1 to 80 parts by weight of hexafluorometal acid and 100 parts by weight of solid content of water-dispersible resin and / or water-soluble resin A method of manufacturing a steel sheet.
[3] In the production method of [1] or [2] above, the surface treatment composition further comprises a water-soluble phosphate, solidified with respect to 100 parts by weight of the water-dispersible resin and / or the solid content of the water-soluble resin. The manufacturing method of the surface treatment steel plate excellent in the white rust resistance characterized by containing 0.1 to 60 weight part in minutes.
[0116]
[4] In the production method of [3], the surface treatment composition is a water-soluble phosphate, and a cationic component and P₂O₅Component molar ratio [cation] / [P₂O₅Is 0.4 to 1.0, and contains a water-soluble phosphate having a cation species of one or more selected from Mn, Mg, Al, and Ni. Method for producing a surface-treated steel sheet having excellent properties.
[5] In the production method according to any one of [1] to [4] above, the surface treatment composition further comprises a non-chromium rust preventive additive, a water-dispersible resin and / or a water-soluble resin having a solid content of 100% by weight. The manufacturing method of the surface treatment steel plate excellent in the white rust resistance characterized by containing 0.1-50 weight part by solid content with respect to a part.
[0117]
[6] In the production method of [5] above, the surface treatment composition includes one or more rust preventive additives selected from the following groups (e1) to (e5) as a non-chromium rust preventive additive. A method for producing a surface-treated steel sheet having excellent white rust resistance, comprising:
(E1) Silicon oxide
(E 2 ) Calcium compounds
(E3) Insoluble phosphate compound
(E4) Molybdate compound
(E5) One or more organic compounds containing S atom selected from triazoles, thiols, thiadiazoles, thiazoles, thiurams
[0118]
[7] In the production method of any one of [1] to [6], the surface treatment composition further contains a solid lubricant with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resin. The manufacturing method of the surface treatment steel plate excellent in the white rust resistance characterized by containing 1-50 weight part by solid content.
[8] In the production method of any one of [1] to [7], the surface treatment composition contains at least one silane coupling agent having an amino group as a reactive functional group as the silane coupling agent. A method for producing a surface-treated steel sheet excellent in white rust resistance, characterized in that:
[0119]
[9] In the production method according to any one of [1] to [8], the surface treatment composition contains one or more elements selected from Ti, Si, and Zr as hexafluorometal acids. A method for producing a surface-treated steel sheet having excellent white rust resistance, comprising at least one acid.
[10] In the production method according to any one of [5] to [9], the surface treatment composition contains calcium ion-exchanged silica as a non-chromium rust preventive additive. A method for producing an excellent surface-treated steel sheet.
[0120]
[11] In the production method according to any one of [1] to [10], the surface treatment composition contains a water-dispersible resin as the component (a), and the water-dispersible resin has a number average molecular weight of 400. A polyalkylene glycol-modified epoxy resin (A) obtained by reacting ˜20,000 polyalkylene glycol, bisphenol type epoxy resin, active hydrogen-containing compound and polyisocyanate compound, and other than the polyalkylene glycol-modified epoxy resin (A) Production of a surface-treated steel sheet having excellent white rust resistance, which is an aqueous epoxy resin dispersion obtained by reacting an epoxy group-containing resin (B) with a hydrazine derivative (C) having active hydrogen Method.
[0121]
[12] In the production method of any one of [1] to [10] above, the surface treatment composition contains a water-dispersible resin as a component of (a), and the water-dispersible resin has a number average molecular weight of 400. A polyalkylene glycol-modified epoxy resin (A) obtained by reacting ˜20,000 polyalkylene glycol, bisphenol-type epoxy resin, active hydrogen-containing compound and polyisocyanate compound, and other than the polyalkylene glycol-modified epoxy resin (A) An aqueous epoxy resin dispersion obtained by reacting an epoxy group-containing resin (B), a hydrazine derivative (C) having active hydrogen, and an active hydrogen-containing compound (D) other than the hydrazine derivative (C). A method for producing a surface-treated steel sheet having excellent white rust resistance.
[0122]
[13] In the production method of [11] or [12], the epoxy group-containing resin (B) is a bisphenol A type epoxy resin having a number average molecular weight of 1500 to 10,000 and an epoxy equivalent of 150 to 5000. A method for producing a surface-treated steel sheet having excellent white rust resistance.
[14] In the production method according to any one of [11] to [13], the aqueous epoxy resin dispersion further contains a curing agent having a group that crosslinks with a hydroxyl group, and has excellent white rust resistance. A method for producing a surface-treated steel sheet.
[15] In the method according to any one of [1] to [14], a surface-treated steel sheet having excellent white rust resistance, wherein a surface-treated film having a film thickness of 0.05 to 5 μm is formed. Production method.
[0123]
[16] The surface thickness of the surface-treated steel sheet obtained by the production method according to any one of [1] to [14] above is 0.02 μm or more and less than 5 μm, and the film thickness is 0.02 μm or more. A method for producing a surface-treated steel sheet having excellent white rust resistance, wherein an organic resin film having a thickness of less than 5 μm is formed such that the total film thickness with the surface-treated film thickness is 5 μm or less.
[17] An organic resin film having a film thickness of 0.05 μm or more and less than 5 μm is formed on an upper surface of the surface-treated film having a film thickness of 0.05 μm or more and less than 5 μm obtained by the production method of [15] above. A method for producing a surface-treated steel sheet having excellent white rust resistance, wherein the film thickness combined with the surface-treated film thickness is 5 μm or less.
[0124]
The above-mentioned surface treatment film may be formed on one side or both sides of the plated steel sheet. Examples of combinations of the film forms on the front and back surfaces of the plated steel sheet include, for example, a single layer film (surface treatment film) / no treatment, two Layer film (surface treatment film + organic resin film) / No treatment, Single layer film (surface treatment film) / Double layer film (surface treatment film + organic resin film), Double layer film (surface treatment film + organic resin film) / It can be set as arbitrary forms, such as a two-layer film (surface treatment film + organic resin film).
[0125]
【Example】
[Example 1]
As the resin composition for the surface treatment composition, a water dispersible resin shown in Table 2 was used, and a silane coupling agent (Table 3), phosphoric acid or hexafluorometal acid (Table 4), water-soluble phosphate ( Table 5), non-chromium rust preventive additive (Table 6) and solid lubricant (Table 7) are appropriately blended and stirred for a predetermined time using a paint disperser (sand grinder) to prepare a surface treatment composition. did.
[0126]
The plated steel sheet shown in Table 1, which is a plated steel sheet for home appliances, building materials, and automobile parts based on cold-rolled steel sheets, was used as a processing original sheet. In addition, the thing of predetermined | prescribed board thickness was employ | adopted for the board thickness of the steel plate according to the objective of evaluation. After the surface of this plated steel sheet was subjected to alkaline degreasing treatment, washed with water and dried, the surface treatment composition was applied with a roll coater and dried by heating at various temperatures. The film thickness of the film was adjusted by the solid content (heating residue) of the surface treatment composition or coating conditions (roll rolling force, rotational speed, etc.).
Tables 8 to 19 show the results of evaluating the film composition and quality performance (film appearance, white rust resistance, conductivity, paint adhesion) of the obtained surface-treated steel sheet. The quality performance was evaluated as follows.
[0127]
(1) Appearance of film
About each sample, the uniformity (existence of unevenness) of the film | membrane external appearance was evaluated visually. The evaluation criteria are as follows.
○: Uniform appearance with no unevenness
Δ: Appearance in which unevenness is slightly noticeable
×: Appearance in which unevenness is conspicuous
(2) White rust resistance
About each sample, the salt spray test (JIS-Z-2371) was given and it evaluated by the white rust area rate after progress for 120 hours. The evaluation criteria are as follows.
: White rust area ratio less than 5%
○: White rust area ratio 5% or more, less than 10%
○-: White rust area ratio of 10% or more and less than 25%
Δ: White rust area ratio of 25% or more and less than 50%
×: White rust area ratio of 50% or more
[0128]
(3) Conductivity
The interlayer insulation resistance value was measured according to JIS C 2550. The evaluation criteria are as follows.
○: 3Ω · cm²/ Less than
Δ: 3-5 Ω · cm²/Sheet
×: 5Ω · cm²/ More than
(4) Paint adhesion
For each sample, a melamine-based baking paint was applied (film thickness 30 μm), then immersed in boiling water for 2 hours, immediately cut into grids (10 × 10, 1 mm intervals), and adhered with adhesive tape. Peeling was performed, and the peeled area ratio of the coating film was measured. The evaluation criteria are as follows.
A: No peeling
○: Peel area ratio less than 5%
Δ: peeling area ratio 5% or more, less than 20%
X: Peeling area ratio 20% or more
[0129]
[Table 1]

[0130]
[Table 2]

[0131]
[Table 3]

[0132]
[Table 4]

[0133]
[Table 5]

[0134]
[Table 6]

[0135]
[Table 7]

[0136]
In addition, * 1 to * 8 described in Tables 8 to 19 indicate the following contents.
* 1: No. described in Table 1. (Plated steel sheet)
* 2: No. in Table 2 (Water dispersible resin)
* 3: No. described in Table 3 (Silane coupling agent)
* 4: No. in Table 4 (Phosphoric acid and / or hexafluorometal acid)
* 5: No. in Table 5 (Water-soluble phosphate)
* 6: No. in Table 6 (Anti-rust additive)
* 7: No. in Table 7 (Solid lubricant)
* 8: parts by weight with respect to 100 parts by weight of solid content of water-dispersible resin and / or water-soluble resin
[0137]
[Table 8]

[0138]
[Table 9]

[0139]
[Table 10]

[0140]
[Table 11]

[0141]
[Table 12]

[0142]
[Table 13]

[0143]
[Table 14]

[0144]
[Table 15]

[0145]
[Table 16]

[0146]
[Table 17]

[0147]
[Table 18]

[0148]
[Table 19]

[0149]
[Example 2]
As the resin composition for the surface treatment composition, an aqueous epoxy resin dispersion shown in Table 20 was used, and a silane coupling agent (Table 3), phosphoric acid or hexafluorometal acid (Table 4), and water-soluble phosphate were used. (Table 21), non-chromium rust preventive additive (Table 6), solid lubricant (Table 7) are appropriately blended, and pH is further adjusted with aqueous ammonia, nitric acid, acetic acid, sulfuric acid, phosphoric acid, hexafluorometal acid, etc. After adjusting to 0.5-6, it stirred for predetermined time using the disperser for coating materials (sand grinder), and prepared the surface treatment composition.
[0150]
The plated steel sheet shown in Table 1, which is a plated steel sheet for home appliances, building materials, and automobile parts based on cold-rolled steel sheets, was used as a processing original sheet. In addition, the thing of predetermined | prescribed board thickness was employ | adopted for the board thickness of the steel plate according to the objective of evaluation. After the surface of this plated steel sheet was subjected to alkaline degreasing treatment, washed with water and dried, the surface treatment composition was applied with a roll coater and dried by heating at various temperatures. The film thickness of the film was adjusted by the solid content (heating residue) of the surface treatment composition or coating conditions (roll rolling force, rotational speed, etc.).
Tables 22 to 33 show the results of evaluating the film composition and quality performance (film appearance, white rust resistance, conductivity, paint adhesion) of the obtained surface-treated steel sheet. The quality performance was evaluated in the same manner as in [Example 1], but the white rust resistance was evaluated by the white rust area ratio after 168 hours had elapsed.
[0151]
Production examples of the aqueous epoxy resin dispersion shown in Table 20 are shown below.
・ Manufacture of polyalkylene glycol-modified epoxy resin
Production Example 1
To a glass four-necked flask equipped with a thermometer, a stirrer, and a condenser tube, 1688 g of polyethylene glycol having a number average molecular weight of 4000 and 539 g of methyl ethyl ketone were added and stirred and mixed at 60 ° C., and then 171 g of tolylene diisocyanate was added. In addition, after reacting for 2 hours, Epicoat 834X90 (epoxy resin, manufactured by Shell Japan, epoxy equivalent 250) 1121 g, 66 g of diethyleneglycolethyl ether and 1.1 g of 1% dibutyltin dilaurate solution were added, and further reacted for 2 hours. I let you. Thereafter, the temperature was raised to 80 ° C. and reacted for 3 hours to confirm that the isocyanate value became 0.6 or less. Thereafter, the temperature was raised to 90 ° C., and methyl ethyl ketone was removed by distillation under reduced pressure until the solid content concentration reached 81.7%. After the removal, 659 g of propylene glycol monomethyl ether and 270 g of deionized water were added and diluted to obtain a polyalkylene glycol-modified epoxy resin solution A1 having a solid concentration of 76%.
[0152]
・ Manufacture of aqueous epoxy resin dispersion
Production Example 2
2029 g of EP1004 (epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent 1000) and 697 g of propylene glycol monobutyl ether were charged into a four-necked flask, heated to 110 ° C., and completely dissolved in 1 hour. After 1180 g of the polyalkylene glycol-modified epoxy resin solution A1 obtained in Production Example 1 and 311.7 g of 3-amino-1,2,4-triazole (molecular weight 84) were added to this product and reacted at 100 ° C. for 5 hours. Then, 719.6 g of propylene glycol monobutyl ether was added to obtain a resin solution D1.
257.6 g of the above resin solution D1 was mixed with 50 g of MF-K60X (isocyanate curing agent, manufactured by Asahi Kasei Kogyo Co., Ltd.) and 0.3 g of Scat24 (curing catalyst), and after stirring well, 692.1 g of water was added dropwise little by little. Mixing and stirring were performed to obtain an aqueous epoxy resin dispersion E1.
[0153]
Production Example 3 (aqueous epoxy resin dispersion containing no hydrazine derivative)
2029 g of EP1004 (epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent 1000) and 697 g of propylene glycol monobutyl ether were charged into a four-necked flask, heated to 110 ° C., and completely dissolved in 1 hour. To this, 1180 g of the polyalkylene glycol-modified epoxy resin solution A1 obtained in Production Example 1 and 527.0 g of propylene glycol monobutyl ether were added to obtain a resin solution D2.
To 257.6 g of the above resin solution D2, 50 g of MF-K60X (isocyanate curing agent, manufactured by Asahi Kasei Kogyo Co., Ltd.) and 0.3 g of Scat24 (curing catalyst) were mixed and stirred well, and then 692.1 g of water was dropped and mixed little by little. The mixture was stirred to obtain an aqueous epoxy resin dispersion E2.
[0154]
[Table 20]

[0155]
[Table 21]

[0156]
In addition, * 1 to * 8 described in Tables 22 to 33 indicate the following contents.
* 1: No. described in Table 1. (Plated steel plate)
* 2: No. in Table 20 (Water dispersible resin)
* 3: No. described in Table 3 (Silane coupling agent)
* 4: No. in Table 4 (Phosphoric acid and / or hexafluorometal acid)
* 5: No. described in Table 21 (Water-soluble phosphate)
* 6: No. in Table 6 (Anti-rust additive)
* 7: No. in Table 7 (Solid lubricant)
* 8: parts by weight with respect to 100 parts by weight of solid content of water dispersible resin
[0157]
[Table 22]

[0158]
[Table 23]

[0159]
[Table 24]

[0160]
[Table 25]

[0161]
[Table 26]

[0162]
[Table 27]

[0163]
[Table 28]

[0164]
[Table 29]

[0165]
[Table 30]

[0166]
[Table 31]

[0167]
[Table 32]

[0168]
[Table 33]

[0177]
【The invention's effect】
As described above, the surface-treated steel sheet of the present invention has very excellent corrosion resistance even though it does not contain chromium in the film, and also has excellent characteristics in terms of film appearance and paint adhesion. .

Claims (16)

On the surface of galvanized steel plate or aluminum galvanized steel plate,
(A) A water-dispersible resin and / or water-soluble resin, which is a reaction product of an epoxy group-containing resin and an active hydrogen-containing compound, and a part or all of the active hydrogen-containing compound is a hydrazine derivative having active hydrogen Resin,
(B) a silane coupling agent;
(C) It contains phosphoric acid and / or hexafluorometal acid, and the content of the silane coupling agent is 15 to 50 parts by weight with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resin. Applying a surface treatment composition having a phosphoric acid and / or hexafluorometal acid content of 5 to 50 parts by weight with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resin , A surface-treated steel sheet excellent in white rust resistance, characterized by having a surface-treated film having a film thickness of 0.02 to 5 μm formed by drying. The surface treatment composition further contains 0.1 to 60 parts by weight of a solid content of the water-soluble phosphate with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or the water-soluble resin. The surface-treated steel sheet excellent in white rust resistance according to claim 1 . The surface treatment composition is a water-soluble phosphate, the molar ratio of the cation component to the P ₂ O ₅ component [cation] / [P ₂ O ₅ ] is 0.4 to 1.0, and the cation species is Mn The surface-treated steel sheet with excellent white rust resistance according to claim 2, comprising one or more water-soluble phosphates selected from Mg, Al, and Ni. The surface treatment composition further comprises 0.1 to 50 parts by weight of a solid content with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or the water-soluble resin. The surface-treated steel sheet excellent in white rust resistance in any one of Claims 1-3 . As the surface treatment composition is chromium-free rust-preventive agent, according to claim 4, characterized in that it contains one or more antirust additive selected from the group of the following (e1) ~ (e5) Surface-treated steel sheet with excellent white rust resistance.
(E1) Silicon oxide
(E 2 ) Calcium compound (e3) Slightly soluble phosphate compound (e4) Molybdate compound (e5) One or more S atoms selected from triazoles, thiols, thiadiazoles, thiazoles, thiurams Contains organic compounds The surface treatment composition further comprises a solid lubricant in an amount of 1 to 50 parts by weight in solid content with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resin . The surface-treated steel sheet excellent in white rust resistance according to any one of 5 . Surface treatment composition, as a silane coupling agent, according to claim 1, characterized in that it contains at least one silane coupling agent having an amino group as a reactive functional group耐白Surface-treated steel sheet with excellent rust. The surface treatment composition contains at least one hexafluorometal acid containing at least one element selected from Ti, Si, and Zr as hexafluorometal acid . A surface-treated steel sheet excellent in white rust resistance according to any one of the above. The surface-treated steel sheet excellent in white rust resistance according to any one of claims 4 to 8, wherein the surface treatment composition contains calcium ion-exchanged silica as a non-chromium-based rust preventive additive. The surface treatment composition contains a water-dispersible resin as the component (a), and the water-dispersible resin is a polyalkylene glycol having a number average molecular weight of 400 to 20000, a bisphenol type epoxy resin, an active hydrogen-containing compound, and a polyisocyanate. A polyalkylene glycol-modified epoxy resin (A) obtained by reacting a compound, an epoxy group-containing resin (B) other than the polyalkylene glycol-modified epoxy resin (A), a hydrazine derivative (C) having active hydrogen, and The surface-treated steel sheet excellent in white rust resistance according to any one of claims 1 to 9, wherein the surface-treated steel sheet is a water-based epoxy resin dispersion liquid obtained by reacting with water. The surface treatment composition contains a water-dispersible resin as the component (a), and the water-dispersible resin is a polyalkylene glycol having a number average molecular weight of 400 to 20000, a bisphenol type epoxy resin, an active hydrogen-containing compound, and a polyisocyanate. A polyalkylene glycol-modified epoxy resin (A) obtained by reacting a compound, an epoxy group-containing resin (B) other than the polyalkylene glycol-modified epoxy resin (A), a hydrazine derivative (C) having active hydrogen, and The white rust resistance according to any one of claims 1 to 9, which is an aqueous epoxy resin dispersion obtained by reacting an active hydrogen-containing compound (D) other than the hydrazine derivative (C). Surface treated steel plate with excellent properties. The surface excellent in white rust resistance according to claim 10 or 11, wherein the epoxy group-containing resin (B) is a bisphenol A type epoxy resin having a number average molecular weight of 1500 to 10000 and an epoxy equivalent of 150 to 5000. Treated steel sheet. The surface-treated steel sheet excellent in white rust resistance according to any one of claims 10 to 12, wherein the aqueous epoxy resin dispersion further contains a curing agent having a group that crosslinks with a hydroxyl group. The surface-treated steel sheet according to any one of claims 1 to 13 , further comprising an organic resin film having a film thickness of 0.02 µm or more and less than 5 µm on an upper layer of the surface-treated film having a thickness of 0.02 µm or more and less than 5 µm. A surface-treated steel sheet excellent in white rust resistance, wherein the total film thickness of the organic resin film and the surface-treated film is 5 μm or less. It is a manufacturing method of the surface treatment steel plate in any one of Claims 1-13 ,
On the surface of zinc-based plated steel sheet or aluminum-based plated steel sheet,
(A) A water-dispersible resin and / or water-soluble resin, which is a reaction product of an epoxy group-containing resin and an active hydrogen-containing compound, and a part or all of the active hydrogen-containing compound is a hydrazine derivative having active hydrogen Resin,
(B) a silane coupling agent;
(C) It contains phosphoric acid and / or hexafluorometal acid, and the content of the silane coupling agent is 15 to 50 parts by weight with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resin. The phosphoric acid and / or hexafluorometal acid content is 5 to 50 parts by weight with respect to 100 parts by weight of the solid content of the water-dispersible resin and / or water-soluble resin, and the pH is 0.5 to 6 The surface treatment composition thus prepared is applied and dried by heating at an ultimate plate temperature of 50 ° C. to 300 ° C. without washing with water to form a surface treatment film with a film thickness of 0.02 to 5 μm. A method for producing a surface-treated steel sheet having excellent white rust resistance. The organic resin film having a film thickness of 0.02 μm or more and less than 5 μm is formed on the upper surface of the surface-treated film having a film thickness of 0.02 μm or more and less than 5 μm obtained by the manufacturing method according to claim 15. A method for producing a surface-treated steel sheet excellent in white rust resistance, characterized in that the total thickness of the surface-treated film is 5 μm or less.