JP2005007771A - Precoated stainless steel sheet excellent in corrosion resistance - Google Patents
Precoated stainless steel sheet excellent in corrosion resistance Download PDFInfo
- Publication number
- JP2005007771A JP2005007771A JP2003175288A JP2003175288A JP2005007771A JP 2005007771 A JP2005007771 A JP 2005007771A JP 2003175288 A JP2003175288 A JP 2003175288A JP 2003175288 A JP2003175288 A JP 2003175288A JP 2005007771 A JP2005007771 A JP 2005007771A
- Authority
- JP
- Japan
- Prior art keywords
- stainless steel
- chemical conversion
- steel sheet
- film
- corrosion resistance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Laminated Bodies (AREA)
- Chemical Treatment Of Metals (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
Abstract
Description
【０００１】
【産業上の利用分野】
本発明は、環境に有害なＣｒ成分が化成処理皮膜，樹脂塗膜の何れにも含まれておらず、優れた耐食性を呈する塗装ステンレス鋼板に関する。
【０００２】
【従来技術及び問題点】
耐食性の良好な鋼材としてステンレス鋼板が多用されているが、環境悪化に伴い鋼板表面が発錆し外観に悪影響を及ぼす場合が散見される。また、ステンレス鋼特有の孔食が進行し、鋼材本来の機能が損なわれることもある。
発錆を防止するため、ステンレス鋼をクロメート処理することがあるが、Ｃｒイオンを含む排液の処理に多大な負担がかかる。そこで、チタン系，ジルコニウム系，モリブデン系，リン酸塩系等の薬液を使用したＣｒフリーの化成処理方法が検討されている。
モリブデン系では、モリブデン酸のマグネシウム又はカルシウム塩を含む水溶液に鋼材を浸漬処理して防錆皮膜を形成する方法（特公昭５１−２４１９号公報），６価モリブデン酸化合物を部分還元し、６価モリブデン／全モリブデンの比を０．２〜０．８に調整した処理液を鋼材表面に塗布する方法（特開平６−１４６００３号公報）等がある。チタン系では、硫酸チタン水溶液及び燐酸を含む処理液を鋼板に塗布し、加熱乾燥することにより、耐食性に優れたチタン化合物含有皮膜を形成している（特開平１１−６１４３１号公報）。
【０００３】
クロメート皮膜に代わる化成処理皮膜として提案されているチタン系，ジルコニウム系，リン酸塩系等の皮膜では、クロメート皮膜にみられるような優れた自己修復作用が得られていない。たとえば、チタン系皮膜は、クロメート皮膜と同様にバリア作用のある酸化物や水酸化物からなる連続皮膜として形成されるが、クロメート皮膜と異なり難溶性であることから自己修復作用を呈さない。そのため、化成処理時や成形加工等の際に生じた皮膜欠陥部を起点とする腐食の抑制には有効でない。他のＣｒフリー皮膜も、チタン系皮膜と同様に自己修復作用が弱く、腐食抑制効果が不充分である。
本出願人は、クロメート皮膜と同様な自己修復作用のある化成処理皮膜について種々調査・検討した結果、バルブメタルの酸化物又は水酸化物とフッ化物とを共存させた化成処理皮膜が有効であることを紹介した（特開２００２−１９４５５８号公報）。この化成処理皮膜は、環境遮断能をバルブメタルの酸化物又は水酸化物で発現させ、可溶性のフッ化物によって自己修復作用を付与している。
【０００４】
【発明が解決しようとする課題】
新しく提案した化成処理皮膜の物性について、本発明者等は種々の観点から調査した。その結果、この化成処理皮膜は、クロメート皮膜に匹敵する塗料密着性を呈することが判った。優れた塗料密着性を活用し、特定の樹脂塗膜と組み合わせるとき、耐食性が格段に良好な塗装ステンレス鋼板が得られることが予想される。
本発明は、このような観点から案出されたものであり、先願で提案した化成処理皮膜とステンレス鋼本来の優れた耐食性を組み合わせ、更に樹脂皮膜を設けることにより、従来にない耐食性が得られ、長期間にわたって美麗な外観を維持する塗装ステンレス鋼板を提供することを目的とする。
【０００５】
【課題を解決するための手段】
本発明の塗装ステンレス鋼板は、ステンレス鋼を基材とし、酸化物が高い絶縁抵抗を示すバルブメタルの酸化物又は水酸化物及びフッ化物が共存する化成処理皮膜を介して樹脂塗膜が形成されていることを特徴とする。
バルブメタルには、Ｔｉ，Ｚｒ，Ｈｆ，Ｖ，Ｎｂ，Ｔａ，Ｍｏ，Ｗから選ばれた１種又は２種以上が使用される。化成処理皮膜は、濃度比Ｆ／Ｏ（原子比率）１／１００以上でＯ及びＦを含むことが好ましい。化成処理皮膜は、更に可溶性又は不溶性金属リン酸塩又は複合リン酸塩を含むことができる。
【０００６】
化成処理皮膜上に形成される樹脂塗膜には、Ｃａイオンをイオン交換で結合させた多孔質シリカ粒子（以下、「変性シリカ」という）を必要に応じて分散させている。変性シリカは、下地の化成処理皮膜と相俟って従来のＣｒ系防錆顔料を凌駕する腐食防止能を呈する。耐食性は、樹脂塗膜にポリリン酸塩を含ませることにより更に向上する。好ましくは、変性シリカ：ポリリン酸塩の質量比が６０：４０〜５：９５で、樹脂成分１００質量部に対して２〜５０質量部の変性シリカを樹脂塗膜に分散させる。
【０００７】
【実施の形態】
塗装原板には、鋼種に特段の制約がなく、フェライト系，オーステナイト系，二相系等、各種ステンレス鋼が使用される。化成処理に先立ってアルカリ脱脂，洗浄，水洗，Ｎｉ置換型表面調整等が必要に応じて施される。
化成処理皮膜は、塗布型又は反応型化成処理液をステンレス鋼板に塗布することにより形成される。反応型化成処理では処理液の安定性を維持する上からｐＨを若干低く調整する。以下の説明では、バルブメタルとしてＴｉを例に採っているが、他のＺｒ，Ｈｆ，Ｖ，Ｎｂ，Ｔａ，Ｍｏ，Ｗのバルブメタルを使用する場合も同様である。
【０００８】
化成処理液は、Ｔｉソースとして可溶性のハロゲン化物や酸素酸塩を含む。Ｔｉのフッ化物はＴｉソース及びＦソースとしても有効であるが、（ＮＨ４）Ｆ等の可溶性フッ化物をＦソースとして化成処理液に別途添加する場合もある。フッ化物を含む化成処理液でステンレス鋼板の表面を処理すると、フッ素イオンによるエッチング効果で鋼板表面が活性化し、バルブメタルとの反応が促進され皮膜の密着性が向上する。バルブメタルは、酸素を介して鋼板表面に結合するものと推察される。
具体的なＴｉソースとしては、ＫｎＴｉＦ６（Ｋ：アルカリ金属又はアルカリ土類金属，ｎ：１又は２），Ｋ２［ＴｉＯ（ＣＯＯ）２］，（ＮＨ４）２ＴｉＦ６，ＴｉＣｌ４，ＴｉＯＳＯ４，Ｔｉ（ＳＯ４）２，Ｔｉ（ＯＨ）４等がある。これらＴｉソースは、化成処理液を塗布した後で乾燥・焼付けするときに所定組成の酸化物又は水酸化物とフッ化物からなる化成処理皮膜が形成されるように各成分の配合比率が選定される。
【０００９】
Ｔｉソースを化成処理液中にイオンとして安定的に維持する上で、キレート作用のある有機酸を添加することが好ましい。有機酸を添加する場合、金属イオンをキレート化して化成処理液を安定させることから、有機酸／金属イオンのモル比が０．０２以上となる添加量に定められる。有機酸としては、酒石酸，タンニン酸，クエン酸，蓚酸，マロン酸，乳酸，酢酸等が挙げられる。なかでも、酒石酸等のオキシカルボン酸やタンニン酸等の多価フェノール類は、処理液を安定化させると共に、フッ化物の自己修復作用を補完する作用も呈し、塗膜密着性の向上にも有効である。
【００１０】
可溶性又は難溶性の金属リン酸塩又は複合リン酸塩を化成処理皮膜に含ませるため、各種金属のオルソリン酸塩やポリリン酸塩を添加してもよい。
可溶性の金属リン酸塩又は複合リン酸塩は、化成処理皮膜から溶出して皮膜欠陥部に溶出し、下地鋼のＺｎ，Ａｌ等と反応して不溶性リン酸塩を析出することによって、チタンフッ化物の自己修復作用を補完する。また、可溶性リン酸塩が解離する際に雰囲気が若干酸性化するため、チタンフッ化物の加水分解、ひいては難溶性チタン酸化物又は水酸化物の生成が促進される。可溶性リン酸塩又は複合リン酸塩を生成する金属にはアルカリ金属，アルカリ土類金属，Ｍｎ等があり、各種金属リン酸塩又は各種金属塩と燐酸，ポリ燐酸，リン酸塩として化成処理液に添加される。
難溶性の金属リン酸塩又は複合リン酸塩は、化成処理皮膜に分散し、皮膜欠陥を解消すると共に皮膜強度を向上させる。難溶性リン酸塩又は複合リン酸塩を形成する金属にはＡｌ，Ｔｉ，Ｚｒ，Ｈｆ，Ｚｎ等があり、各種金属リン酸塩又は各種金属塩と燐酸，ポリ燐酸，リン酸塩として化成処理液に添加される。
【００１１】
化成処理液には、潤滑性の向上に有効なワックスを化成処理皮膜に含ませるため、フッ素系，ポリエチレン系，スチレン系等の有機ワックスやシリカ，二硫化モリブデン，タルク等の無機質潤滑剤等を添加することもできる。低融点の有機ワックスは、皮膜乾燥時に表面にブリードし、潤滑性を発現すると考えられる。高融点有機ワックスや無機系潤滑剤は、皮膜中に分散状態で存在するが，処理皮膜の最表層では島状分布で皮膜表面に露出することによって潤滑性が発現するものと考えられる。
更に、タンニン酸，澱粉，コーンスターチ，ポリビニルアルコール，アミノメチル化ポリビニルフェノール等を添加しても良い。これら添加成分は、化成処理皮膜に可撓性を付与し、加工部における塗膜密着性を向上させる。また、塗膜との密着性を向上させるためにＳｉＯ２を添加しても良い。
【００１２】
調製された化成処理液をロールコート法，スピンコート法，スプレー法等で化成処理用原板に塗布し、水洗することなく乾燥することによって、耐食性に優れた化成処理皮膜がステンレス鋼板の表面に形成される。化成処理液の塗布量は、十分な耐食性を確保するため１ｍｇ／ｍ２以上のバルブメタル付着量となるように調整することが好ましい。なお、化成処理液の塗布に先立って、酸洗，Ｎｉ析出，Ｃｏ析出等の表面調整処理を原板に適宜施しても良い。
形成された化成処理皮膜を蛍光Ｘ線，ＥＳＣＡ等で元素分析すると、化成処理皮膜に含まれているＯ及びＦ濃度が測定される。測定値から算出した濃度比Ｆ／Ｏ（原子比率）と耐食性との関係を調査したところ、濃度比Ｆ／Ｏ（原子比率）１／１００以上で皮膜欠陥部を起点とする腐食の発生が大幅に減少した。これは、自己修復作用のあるチタンフッ化物が十分な量で化成処理皮膜中に含まれていることによるものと推察される。
【００１３】
化成処理皮膜は、常温で乾燥することもできるが、連続操業を考慮すると５０℃以上に保持して乾燥時間を短縮することが好ましい。ただし、２００℃を超える乾燥温度では、化成処理被膜に含まれている有機成分が熱分解し、有機成分で付与された特性が損なわれることがある。
化成処理皮膜を形成した後、更に樹脂塗料を塗布・焼付けすることにより樹脂塗膜を形成する。塗膜のベース樹脂は塗装ステンレス鋼板の用途に応じて適宜選択されるが、樹脂塗膜によって加工時潤滑性が向上するため塗装ステンレス鋼板の加工性が改善される。また、導電性に優れた樹脂塗膜を形成すると、塗装ステンレス鋼板の溶接性も向上する。
【００１４】
樹脂塗料としては、ウレタン系樹脂，エポキシ樹脂，ポリエチレン、ポリプロピレン，エチレン−アクリル酸共重合体等のオレフィン系樹脂，ポリスチレン等のスチレン系樹脂，ポリエステル，或いはこれらの共重合物又は変性物，アクリル系樹脂等をベースとした塗料が使用される。
基材・ステンレス鋼に耐食性が優れた化成処理皮膜を形成しているので、樹脂塗料に防錆顔料を添加しなくても長期にわたって美麗な外観を維持する塗装ステンレス鋼板が得られる。しかし、本発明は樹脂塗料への防錆顔料添加を排除するものではなく、防錆剤を樹脂塗膜に分散させるとき更なる耐食性の向上が図られる。
防錆顔料としては、環境負荷の大きなＣｒ系防錆顔料に代えて変性シリカ及び必要に応じてポリリン酸塩を使用する。
変性シリカは、イオン交換によってＣａイオンを結合させた多孔質シリカ粒子であり、Ｈイオン等の腐食性イオンをＣａイオンで捕捉することにより腐食抑制能を発現する。変性シリカの腐食抑制能は、樹脂成分１００質量部に２〜５０質量部の割合で変性シリカを配合するとき顕著になる。
【００１５】
変性シリカに加えてポリリン酸塩を添加すると、樹脂塗膜中へのＣａイオンの溶出が抑制され、変性シリカの腐食抑制能が長期間にわたって維持される。使用可能なポリリン酸塩には、ピロリン酸アルミニウム，メタリン酸アルミニウム，トリポリリン酸二水素アルミニウム等がある。ポリリン酸塩は、シランカップリング剤やシリコーンオイル等の疎水性皮膜と異なり、シリカ粒子の表面にキレート結合のようなイオン結合を形成しＣａイオンの溶出を抑制するため、変性シリカの腐食抑制能が損なわれない。Ｃａイオンの溶出抑制には、変性シリカ／ポリリン酸塩の質量比を６０／４０〜５／９５の範囲に維持することが好ましい。
【００１６】
樹脂塗料は、好ましくは膜厚０．１〜２０μｍの樹脂塗膜が形成される割合で化成処理されたステンレス鋼板に塗布される。膜厚０．１μｍ以上でピンホール，未塗装部等の欠陥がない均一な樹脂塗膜が形成される。しかし、２０μｍを超える厚膜では、塗装ステンレス鋼板を成形加工する際樹脂塗膜に亀裂，剥離等が生じやすくなる。
変性シリカ分散樹脂塗膜の上に、更に一層又は二層以上の塗膜を設けることができる。この塗膜は、変性シリカが分散した塗膜，変性シリカのない塗膜の何れでも良い。具体的には、変性シリカを分散させた膜厚５μｍの樹脂塗膜の上に、高分子ポリエステル塗料を２３０℃×４０秒で焼き付けた膜厚１５μｍの上塗り塗膜がある。
【００１７】
【実施例１】
Ｔｉソース及びＦソースを配合し、必要に応じて各種金属化合物，有機酸，リン酸塩を更に添加し、表１の組成をもつ化成処理液を調合した。
【００１８】
化成処理用原板として、板厚０．５ｍｍのオーステナイト系（ＳＵＳ３０４），フェライト系（ＳＵＳ４３０）ステンレス鋼板を使用した。各ステンレス鋼板を脱脂，酸洗することにより化成処理用原板を用意した。
表１の化成処理液をステンレス鋼板に塗布し、水洗することなく電気オーブンに装入し、板温５０〜２００℃で加熱乾燥した。比較材として、市販のクロメート処理液（ＺＭ−３３８７：日本パーカライジング株式会社製）をステンレス鋼板に塗布し、同様に水洗せずに板温１５０℃で加熱乾燥した。
ステンレス鋼板の表面に形成された化成処理皮膜を分析したところ、表２に示す濃度で各成分が含まれていた。
【００２０】
化成処理された各ステンレス鋼板から試験片を切り出し、腐食試験に供した。
平坦部腐食試験では、試験片の端面をシールし、ＪＩＳ Ｚ２３７１に準拠して３５℃の５％ＮａＣｌ水溶液を噴霧した。塩水噴霧を５００，１０００及び２０００時間継続した後、試験片表面における孔食の発生状況を調査した。孔食深さを測定し、最大深さ０．５ｍｍを超える孔食が成長した試験片を×，孔食の最大深さが０．１〜０．５ｍｍにある試験片を△，最大深さが０．１ｍｍ以下に抑えられている試験片を○として平坦部の耐食性を評価した。
加工部腐食試験では、試験片を１８０度曲げ加工した後、同様な塩水噴霧を５００，１０００時間継続した。そして、加工部表面に発生した孔食の最大深さから平坦部腐食試験と同様に加工部の耐食性を評価した。
【００２２】
表３の調査結果にみられるように、本発明に従って形成された試験番号１〜６の化成処理皮膜は、平坦部及び加工部共に従来のクロメート皮膜を凌駕する優れた耐食性を呈することが判る。リン酸塩を含まない試験番号７であっても、試験時間が短い場合に比較的良好な耐食性が得られた。
他方、可溶性のチタンフッ化物を含まない試験番号８（比較例）では、加工部に生じた皮膜欠陥部を起点とする腐食が観察された。チタン化合物を含まない試験番号９（比較例）では、平坦部，加工部共に耐食性が低下していた。
【００２３】
耐食性の優れた化成処理皮膜が形成された試験番号１のステンレス鋼板を塗装原板として樹脂塗膜を形成した。樹脂塗料には、変性シリカ及びポリリン酸塩を種々の割合で配合したエポキシ変性高分子ポリエステル系樹脂塗料（表４）を使用した。塗装原板に塗布した樹脂塗料を最高到達板温２１５℃で４０秒間焼付けることにより、膜厚１０μｍの樹脂塗膜を形成した。
【００２５】
得られた塗装ステンレス鋼板から試験片を切り出し、以下の試験で塗膜性能を調査した。
〔沸騰水試験〕
試験片を沸騰水に２時間浸漬した後、沸騰水から引き上げた試験片の塗膜を観察し、フクレ又は艶引けの有無により耐沸騰水性を評価した。同じく沸騰水から引き上げられた試験片を０ｔ曲げ加工し、曲げ部にテープを一旦貼り付けて引き剥がすテーピング試験後に塗膜を観察し、塗膜剥離の有無によって加工性を評価した。
【００２７】
〔腐食・湿潤試験〕
下地鋼に達するクロスカットを試験片に入れた後、ＪＩＳ Ｚ２３７１に準拠した２４０時間の塩水噴霧試験及び５０℃，９８％ＲＨの雰囲気に２４０時間放置する試験に供した。試験後に試験片の平坦部を観察し、異常発生の有無によって平坦部耐食性を評価した。また、下バリ端面最大フクレ幅及びクロスカット片側最大フクレ幅を測定し、最大フクレ幅によって耐食性及び耐湿性を評価した。
【００２８】
何れの試験片でも、沸騰水浸漬後の塗膜にフクレや艶引けが検出されず、沸騰水浸漬後の０ｔ曲げでも塗膜剥離が生じなかった。腐食試験や湿潤試験でも塗膜に異常が観察されず、最大フクレ幅も１ｍｍ以下と極僅かであった。
また、変性シリカ無添加のエポキシ変性高分子ポリエステル系樹脂塗料を用いて樹脂塗膜を形成した塗装ステンレス鋼板を同様に試験したところ、この場合にも沸騰水浸漬後の塗膜にフクレや艶引けが検出されず、沸騰水浸漬後の０ｔ曲げでも塗膜剥離が生じなかった。これは、基材・ステンレス鋼板，化成処理皮膜の優れた耐食性が活かされ、防錆顔料無添加の樹脂塗膜であっても十分に要求特性を満足することを意味する。
以上の結果から明らかなように、バルブメタルの酸化物又は水酸化物とフッ化物が共存する化成処理皮膜を介してステンレス鋼板表面に樹脂塗膜を形成するとき、環境に悪影響を及ぼすクロメート皮膜やＣｒ系防錆顔料を必要とすることなく、耐食性，加工性に優れた塗装ステンレス鋼板が得られることが確認された。
【００２９】
【実施例２】
表５の化成処理液を使用し、実施例１と同様にステンレス鋼板を化成処理した。ステンレス鋼板表面に形成された化成処理皮膜を分析したところ、表６に示す濃度で各成分が含まれていた。
【００３０】
化成処理されたステンレス鋼板に実施例１と同じ樹脂塗料（表４）を塗布・焼付けし、膜厚１０μｍの樹脂塗膜を形成した。得られた塗装ステンレス鋼板から試験片を切り出し、実施例１と同様に耐食試験したところ、何れも平坦部，加工部共に優れた耐食性を呈した。
【００３３】
【発明の効果】
以上に説明したように、本発明の塗装ステンレス鋼板は、耐食性に優れたＣｒフリーの化成処理皮膜を介して樹脂塗膜を設けている。この塗装ステンレス鋼板は、環境に悪影響を及ぼすクロメート皮膜やＣｒ系防錆顔料を必要とすることなく、耐食性，加工性，塗膜密着性にも優れているので、外装材，内装材，表装材，機械構造用部材等として広範な分野で使用される。[0001]
[Industrial application fields]
The present invention relates to a coated stainless steel plate that does not contain Cr components harmful to the environment in either the chemical conversion coating film or the resin coating film, and exhibits excellent corrosion resistance.
[0002]
[Prior art and problems]
Stainless steel plates are frequently used as steel materials with good corrosion resistance, but there are some cases where the steel plate surface rusts and the appearance is adversely affected as the environment deteriorates. Moreover, pitting corrosion peculiar to stainless steel progresses, and the original function of the steel material may be impaired.
In order to prevent rusting, the stainless steel may be chromated, but a great burden is imposed on the treatment of the drainage containing Cr ions. Therefore, a Cr-free chemical conversion treatment method using a chemical solution such as titanium, zirconium, molybdenum, or phosphate has been studied.
In the molybdenum system, a method in which a steel material is immersed in an aqueous solution containing magnesium or calcium salt of molybdate to form a rust preventive film (Japanese Patent Publication No. 51-2419), a hexavalent molybdate compound is partially reduced, and hexavalent There is a method of applying a treatment liquid having a molybdenum / total molybdenum ratio adjusted to 0.2 to 0.8 to the surface of a steel material (Japanese Patent Laid-Open No. 6-146003). In the titanium system, a titanium compound-containing film having excellent corrosion resistance is formed by applying a treatment solution containing a titanium sulfate aqueous solution and phosphoric acid to a steel sheet and drying by heating (Japanese Patent Laid-Open No. 11-61431).
[0003]
Titanium-based, zirconium-based, and phosphate-based coatings proposed as chemical conversion coatings to replace chromate coatings do not have the excellent self-repairing action found in chromate coatings. For example, the titanium-based film is formed as a continuous film made of an oxide or hydroxide having a barrier action like the chromate film. However, unlike the chromate film, the titanium-based film does not exhibit a self-repairing action because it is hardly soluble. Therefore, it is not effective in suppressing corrosion starting from a film defect portion generated during chemical conversion treatment or molding. Other Cr-free coatings, like the titanium-based coatings, have a weak self-repairing action and are insufficient in corrosion inhibition.
As a result of various investigations and examinations of a chemical conversion treatment film having a self-repairing effect similar to the chromate film, the present applicant has found that a chemical conversion treatment film in which a valve metal oxide or hydroxide coexists with fluoride is effective. (Japanese Patent Laid-Open No. 2002-194558). This chemical conversion treatment film exhibits an environmental barrier ability with an oxide or hydroxide of valve metal and imparts a self-healing action with a soluble fluoride.
[0004]
[Problems to be solved by the invention]
The present inventors investigated the physical properties of the newly proposed chemical conversion coating from various viewpoints. As a result, it was found that this chemical conversion film exhibits paint adhesion comparable to that of the chromate film. It is expected that a coated stainless steel sheet with significantly better corrosion resistance can be obtained when utilizing excellent paint adhesion and combining with a specific resin coating film.
The present invention has been devised from such a viewpoint. Combining the chemical conversion treatment film proposed in the prior application with the excellent corrosion resistance inherent in stainless steel, and further providing a resin film, an unprecedented corrosion resistance is obtained. An object of the present invention is to provide a coated stainless steel sheet that maintains a beautiful appearance over a long period of time.
[0005]
[Means for Solving the Problems]
The coated stainless steel sheet of the present invention has a resin coating film formed through a chemical conversion coating film in which a valve metal oxide or hydroxide and fluoride coexisting with stainless steel as a base material and having high insulation resistance. It is characterized by.
As the valve metal, one or more selected from Ti, Zr, Hf, V, Nb, Ta, Mo, and W are used. The chemical conversion film preferably contains O and F at a concentration ratio F / O (atomic ratio) of 1/100 or more. The chemical conversion treatment film may further contain a soluble or insoluble metal phosphate or a composite phosphate.
[0006]
In the resin coating film formed on the chemical conversion coating film, porous silica particles (hereinafter referred to as “modified silica”) in which Ca ions are bonded by ion exchange are dispersed as necessary. The modified silica, when combined with the underlying chemical conversion coating, exhibits a corrosion prevention capability that surpasses conventional Cr anticorrosive pigments. Corrosion resistance is further improved by including polyphosphate in the resin coating. Preferably, the modified silica: polyphosphate mass ratio is 60:40 to 5:95, and 2 to 50 parts by mass of the modified silica is dispersed in the resin coating film with respect to 100 parts by mass of the resin component.
[0007]
Embodiment
There are no particular restrictions on the type of steel used for the coating plate, and various types of stainless steel such as ferritic, austenitic, and dual phase types are used. Prior to the chemical conversion treatment, alkali degreasing, washing, washing with water, Ni-substitution surface conditioning and the like are performed as necessary.
The chemical conversion treatment film is formed by applying a coating type or reaction type chemical conversion treatment solution to a stainless steel plate. In the reactive chemical conversion treatment, the pH is adjusted slightly lower in order to maintain the stability of the treatment liquid. In the following description, Ti is taken as an example of the valve metal, but the same applies when other Zr, Hf, V, Nb, Ta, Mo, and W valve metals are used.
[0008]
The chemical conversion treatment solution contains a soluble halide or oxyacid salt as a Ti source. Ti fluoride is effective as a Ti source and an F source, but a soluble fluoride such as (NH 4 ) F may be separately added to the chemical conversion solution as an F source. When the surface of the stainless steel plate is treated with a chemical conversion treatment solution containing fluoride, the steel plate surface is activated by the etching effect of fluorine ions, the reaction with the valve metal is promoted, and the adhesion of the coating is improved. It is inferred that the valve metal is bonded to the surface of the steel plate through oxygen.
Specific Ti sources include K n TiF 6 (K: alkali metal or alkaline earth metal, n: 1 or 2), K 2 [TiO (COO) 2 ], (NH 4 ) 2 TiF 6 , TiCl 4. , TiOSO 4 , Ti (SO 4 ) 2 , Ti (OH) 4 and the like. In these Ti sources, the compounding ratio of each component is selected so that a chemical conversion treatment film composed of an oxide or hydroxide of a predetermined composition and a fluoride is formed when the chemical conversion treatment liquid is applied and then dried and baked. The
[0009]
In order to stably maintain the Ti source as ions in the chemical conversion solution, it is preferable to add an organic acid having a chelating action. In the case of adding an organic acid, metal ions are chelated to stabilize the chemical conversion treatment solution, so that the organic acid / metal ion molar ratio is determined to be 0.02 or more. Examples of the organic acid include tartaric acid, tannic acid, citric acid, succinic acid, malonic acid, lactic acid, acetic acid and the like. Among them, polyphenols such as oxycarboxylic acid such as tartaric acid and tannic acid stabilize the treatment liquid and also complement the self-healing action of fluoride, and are also effective in improving coating film adhesion. It is.
[0010]
In order to include a soluble or hardly soluble metal phosphate or composite phosphate in the chemical conversion film, various metal orthophosphates and polyphosphates may be added.
Soluble metal phosphate or composite phosphate elutes from the chemical conversion coating and elutes in the coating defect, reacts with Zn, Al, etc. of the base steel to precipitate insoluble phosphate, thereby producing titanium fluoride. Complements the self-healing action of Further, since the atmosphere is slightly acidified when the soluble phosphate is dissociated, the hydrolysis of titanium fluoride, and hence the generation of hardly soluble titanium oxide or hydroxide, is promoted. Metals that produce soluble phosphates or complex phosphates include alkali metals, alkaline earth metals, Mn, etc., various metal phosphates or various metal salts and phosphoric acid, polyphosphoric acid, phosphate chemical conversion treatment liquid To be added.
Slightly soluble metal phosphates or composite phosphates are dispersed in the chemical conversion coating to eliminate coating defects and improve coating strength. There are Al, Ti, Zr, Hf, Zn, etc. as metals that form poorly soluble phosphates or complex phosphates. Various metal phosphates or various metal salts and phosphoric acid, polyphosphoric acid, phosphate conversion treatment Added to the liquid.
[0011]
In order to include a wax that is effective in improving lubricity in the chemical conversion treatment film, the chemical conversion solution contains organic waxes such as fluorine, polyethylene, and styrene, and inorganic lubricants such as silica, molybdenum disulfide, and talc. It can also be added. The low melting point organic wax is considered to bleed on the surface when the film is dried and to exhibit lubricity. High melting point organic waxes and inorganic lubricants are present in a dispersed state in the film, but it is considered that lubricity is manifested by exposure to the film surface in an island-like distribution in the outermost layer of the treated film.
Further, tannic acid, starch, corn starch, polyvinyl alcohol, aminomethylated polyvinylphenol, etc. may be added. These additive components impart flexibility to the chemical conversion coating and improve the adhesion of the coating film in the processed part. Further, SiO 2 may be added in order to improve the adhesion with the coating film.
[0012]
The prepared chemical conversion solution is applied to the chemical conversion original plate by roll coating, spin coating, spraying, etc., and dried without washing to form a chemical conversion coating with excellent corrosion resistance on the surface of the stainless steel plate. Is done. It is preferable to adjust the coating amount of the chemical conversion treatment liquid so that the valve metal adhesion amount is 1 mg / m 2 or more in order to ensure sufficient corrosion resistance. Prior to the application of the chemical conversion treatment solution, surface adjustment treatment such as pickling, Ni precipitation, and Co precipitation may be appropriately performed on the original plate.
When the formed chemical conversion film is subjected to elemental analysis with fluorescent X-rays, ESCA or the like, the O and F concentrations contained in the chemical conversion film are measured. When the relationship between the concentration ratio F / O (atomic ratio) calculated from the measured values and the corrosion resistance was investigated, the occurrence of corrosion starting from the film defects was significantly observed at a concentration ratio F / O (atomic ratio) of 1/100 or more. Decreased. This is presumably due to the fact that a sufficient amount of titanium fluoride having a self-repairing action is contained in the chemical conversion film.
[0013]
Although a chemical conversion treatment film can also be dried at normal temperature, when continuous operation is considered, it is preferable to hold at 50 degreeC or more and to shorten drying time. However, when the drying temperature exceeds 200 ° C., the organic component contained in the chemical conversion coating film is thermally decomposed, and the properties imparted with the organic component may be impaired.
After forming the chemical conversion coating, a resin coating is formed by applying and baking a resin coating. The base resin of the coating film is appropriately selected according to the application of the coated stainless steel sheet. However, since the lubricity during processing is improved by the resin coating film, the workability of the coated stainless steel sheet is improved. Moreover, when the resin coating film excellent in electroconductivity is formed, the weldability of a coated stainless steel plate will also improve.
[0014]
Examples of resin coatings include urethane resins, epoxy resins, polyethylene, polypropylene, olefin resins such as ethylene-acrylic acid copolymers, styrene resins such as polystyrene, polyesters, copolymers or modified products thereof, and acrylic resins. A paint based on resin or the like is used.
Since a chemical conversion film having excellent corrosion resistance is formed on the base material / stainless steel, a coated stainless steel sheet that maintains a beautiful appearance over a long period of time can be obtained without adding a rust preventive pigment to the resin paint. However, the present invention does not exclude the addition of a rust preventive pigment to the resin paint, and when the rust preventive agent is dispersed in the resin coating film, the corrosion resistance is further improved.
As the rust preventive pigment, modified silica and, if necessary, polyphosphate are used instead of the Cr-based rust preventive pigment having a large environmental load.
Modified silica is porous silica particles in which Ca ions are bonded by ion exchange, and exhibits corrosion inhibiting ability by capturing corrosive ions such as H ions with Ca ions. The corrosion inhibiting ability of the modified silica becomes remarkable when the modified silica is blended at a ratio of 2 to 50 parts by mass with 100 parts by mass of the resin component.
[0015]
When polyphosphate is added in addition to the modified silica, the elution of Ca ions into the resin coating is suppressed, and the corrosion inhibiting ability of the modified silica is maintained over a long period of time. Usable polyphosphates include aluminum pyrophosphate, aluminum metaphosphate, aluminum dihydrogen tripolyphosphate, and the like. Unlike hydrophobic coatings such as silane coupling agents and silicone oil, polyphosphate forms an ionic bond such as a chelate bond on the surface of silica particles and suppresses the elution of Ca ions. Is not impaired. In order to suppress Ca ion elution, it is preferable to maintain the mass ratio of modified silica / polyphosphate in the range of 60/40 to 5/95.
[0016]
The resin coating is preferably applied to a stainless steel plate that has been subjected to chemical conversion treatment at a rate at which a resin coating film having a film thickness of 0.1 to 20 μm is formed. A uniform resin coating film having a film thickness of 0.1 μm or more and free from defects such as pinholes and unpainted parts is formed. However, if the film thickness exceeds 20 μm, cracking, peeling and the like are likely to occur in the resin coating film when the coated stainless steel sheet is formed.
On the modified silica-dispersed resin coating film, a single layer or two or more layers can be provided. This coating film may be either a coating film in which modified silica is dispersed or a coating film without modified silica. Specifically, there is a 15 μm-thick topcoat film obtained by baking a polymer polyester paint at 230 ° C. for 40 seconds on a 5 μm-thick resin film in which modified silica is dispersed.
[0017]
[Example 1]
A Ti source and an F source were blended, and various metal compounds, organic acids, and phosphates were further added as necessary to prepare a chemical conversion treatment liquid having the composition shown in Table 1.
[0018]
An austenitic (SUS304) or ferritic (SUS430) stainless steel plate having a thickness of 0.5 mm was used as a raw sheet for chemical conversion treatment. Each stainless steel plate was degreased and pickled to prepare a raw plate for chemical conversion treatment.
The chemical conversion treatment liquid of Table 1 was applied to a stainless steel plate, charged into an electric oven without being washed with water, and dried by heating at a plate temperature of 50 to 200 ° C. As a comparative material, a commercially available chromate treatment solution (ZM-3387: manufactured by Nihon Parkerizing Co., Ltd.) was applied to a stainless steel plate, and similarly heat-dried at a plate temperature of 150 ° C. without being washed with water.
When the chemical conversion film formed on the surface of the stainless steel plate was analyzed, each component was contained at the concentrations shown in Table 2.
[0020]
A test piece was cut out from each chemically treated stainless steel plate and subjected to a corrosion test.
In the flat part corrosion test, the end face of the test piece was sealed and sprayed with a 5% NaCl aqueous solution at 35 ° C. in accordance with JIS Z2371. After the salt spray was continued for 500, 1000 and 2000 hours, the state of occurrence of pitting corrosion on the surface of the test piece was investigated. Measure the pitting corrosion depth, x the test piece on which the pitting corrosion exceeding the maximum depth of 0.5 mm has grown, △ the test piece having the maximum pitting corrosion depth of 0.1-0.5 mm, the maximum depth The corrosion resistance of the flat portion was evaluated with a test piece having a thickness of 0.1 mm or less as “◯”.
In the processed part corrosion test, after the test piece was bent 180 degrees, similar salt spray was continued for 500,1000 hours. And the corrosion resistance of the process part was evaluated similarly to the flat part corrosion test from the maximum depth of the pitting corrosion which generate | occur | produced on the process part surface.
[0022]
As can be seen from the investigation results of Table 3, it can be seen that the chemical conversion coatings of Test Nos. 1 to 6 formed according to the present invention exhibit excellent corrosion resistance that surpasses the conventional chromate coatings in both the flat portion and the processed portion. Even with test number 7 containing no phosphate, relatively good corrosion resistance was obtained when the test time was short.
On the other hand, in Test No. 8 (Comparative Example) that does not contain soluble titanium fluoride, corrosion starting from a film defect portion generated in the processed portion was observed. In test number 9 (comparative example) not containing a titanium compound, the corrosion resistance of both the flat part and the processed part was lowered.
[0023]
A resin coating film was formed using a stainless steel plate of Test No. 1 on which a chemical conversion coating having excellent corrosion resistance was formed as a coating base plate. As the resin paint, an epoxy-modified polymer polyester resin paint (Table 4) in which modified silica and polyphosphate were blended in various proportions was used. A resin coating having a thickness of 10 μm was formed by baking the resin coating applied to the coating original plate for 40 seconds at a maximum plate temperature of 215 ° C.
[0025]
A test piece was cut out from the obtained coated stainless steel plate, and the coating film performance was examined by the following test.
[Boiling water test]
After immersing the test piece in boiling water for 2 hours, the coating film of the test piece pulled up from the boiling water was observed, and the boiling water resistance was evaluated by the presence or absence of swelling or glossiness. Similarly, the test piece pulled up from boiling water was subjected to 0-t bending process, the coating film was observed after a taping test in which a tape was once attached to the bent portion and then peeled off, and the workability was evaluated based on the presence or absence of coating film peeling.
[0027]
[Corrosion / wet test]
After putting the crosscut reaching the base steel into a test piece, it was subjected to a salt spray test for 240 hours according to JIS Z2371 and a test to be left in an atmosphere of 50 ° C. and 98% RH for 240 hours. The flat part of the test piece was observed after the test, and the flat part corrosion resistance was evaluated based on whether or not an abnormality occurred. Further, the maximum burr width on the lower burr end face and the maximum burr width on one side of the cross cut were measured, and the corrosion resistance and moisture resistance were evaluated by the maximum burr width.
[0028]
In any of the test pieces, no swelling or glossiness was detected in the coating film after immersion in boiling water, and no peeling of the coating film occurred even when bent at 0 t after immersion in boiling water. In the corrosion test and the wet test, no abnormality was observed in the coating film, and the maximum swelling width was 1 mm or less.
In addition, when a coated stainless steel sheet in which a resin coating film was formed using an epoxy-modified high molecular weight polyester resin coating material without addition of modified silica was tested in the same manner, in this case as well, the coating film after immersion in boiling water was inflated or gloss-stained. Was not detected, and coating film peeling did not occur even at 0t bending after immersion in boiling water. This means that the excellent corrosion resistance of the base material / stainless steel plate and chemical conversion coating is utilized, and the required properties are sufficiently satisfied even with a resin coating film containing no rust preventive pigment.
As is clear from the above results, when a resin coating is formed on the surface of a stainless steel plate via a chemical conversion coating in which a valve metal oxide or hydroxide and fluoride coexist, It was confirmed that a coated stainless steel sheet excellent in corrosion resistance and workability can be obtained without the need for a Cr-based rust preventive pigment.
[0029]
[Example 2]
Using the chemical conversion treatment liquid in Table 5, a stainless steel plate was subjected to chemical conversion treatment in the same manner as in Example 1. When the chemical conversion film formed on the surface of the stainless steel plate was analyzed, each component was contained at the concentrations shown in Table 6.
[0030]
The same resin paint (Table 4) as in Example 1 was applied and baked on the chemically treated stainless steel plate to form a resin film having a thickness of 10 μm. When a test piece was cut out from the obtained coated stainless steel plate and subjected to a corrosion resistance test in the same manner as in Example 1, both the flat portion and the processed portion exhibited excellent corrosion resistance.
[0033]
【The invention's effect】
As described above, the coated stainless steel sheet of the present invention is provided with a resin coating film through a Cr-free chemical conversion coating film excellent in corrosion resistance. This coated stainless steel sheet does not require a chromate film or Cr-based anticorrosive pigment that adversely affects the environment, and is excellent in corrosion resistance, workability, and coating film adhesion. , Used in a wide range of fields as machine structural members.
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003175288A JP4027848B2 (en) | 2003-06-19 | 2003-06-19 | Painted stainless steel plate with excellent corrosion resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003175288A JP4027848B2 (en) | 2003-06-19 | 2003-06-19 | Painted stainless steel plate with excellent corrosion resistance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2005007771A true JP2005007771A (en) | 2005-01-13 |
| JP4027848B2 JP4027848B2 (en) | 2007-12-26 |
Family
ID=34098530
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2003175288A Expired - Lifetime JP4027848B2 (en) | 2003-06-19 | 2003-06-19 | Painted stainless steel plate with excellent corrosion resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4027848B2 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007022058A (en) * | 2005-06-14 | 2007-02-01 | Toyo Kohan Co Ltd | Metal sheet coated with electroconductive film |
| JP2007261110A (en) * | 2006-03-29 | 2007-10-11 | Nisshin Steel Co Ltd | Transparent fluororesin precoated stainless steel sheet |
| JP2008050640A (en) * | 2006-08-23 | 2008-03-06 | Jfe Steel Kk | Surface treated metallic plate and method of manufacturing the same, resin-coated metallic plate, metallic can and metallic lid |
| JP2011207132A (en) * | 2010-03-30 | 2011-10-20 | Nisshin Steel Co Ltd | Coated embossed steel sheet and method of manufacturing the same |
| JP2015134957A (en) * | 2013-12-18 | 2015-07-27 | 日本パーカライジング株式会社 | Aqueous metal surface treatment agent, metal surface treatment film and metal material having metal surface treatment film |
| CN115182196A (en) * | 2022-07-14 | 2022-10-14 | 浙江天益塑业有限公司 | Waterproof wear-resistant paper-plastic composite bag and preparation method thereof |
| CN116356126A (en) * | 2023-03-30 | 2023-06-30 | 江苏甬金金属科技有限公司 | Ultrathin corrosion-resistant silicon steel strip and preparation method thereof |
| CN118087000A (en) * | 2024-04-26 | 2024-05-28 | 诸暨市中俄联合材料实验室 | Micro-arc oxidation/thermoelectric chemical oxidation method of non-valve metal |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6140584B2 (en) | 2013-09-11 | 2017-05-31 | 新日鐵住金ステンレス株式会社 | Clear painted stainless steel sheet |
| CN113272133B (en) | 2019-03-28 | 2023-07-18 | 日铁不锈钢株式会社 | Transparent coating stainless steel plate |
-
2003
- 2003-06-19 JP JP2003175288A patent/JP4027848B2/en not_active Expired - Lifetime
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007022058A (en) * | 2005-06-14 | 2007-02-01 | Toyo Kohan Co Ltd | Metal sheet coated with electroconductive film |
| JP2007261110A (en) * | 2006-03-29 | 2007-10-11 | Nisshin Steel Co Ltd | Transparent fluororesin precoated stainless steel sheet |
| JP4588658B2 (en) * | 2006-03-29 | 2010-12-01 | 日新製鋼株式会社 | Transparent fluororesin coated stainless steel sheet |
| JP2008050640A (en) * | 2006-08-23 | 2008-03-06 | Jfe Steel Kk | Surface treated metallic plate and method of manufacturing the same, resin-coated metallic plate, metallic can and metallic lid |
| JP2011207132A (en) * | 2010-03-30 | 2011-10-20 | Nisshin Steel Co Ltd | Coated embossed steel sheet and method of manufacturing the same |
| JP2015134957A (en) * | 2013-12-18 | 2015-07-27 | 日本パーカライジング株式会社 | Aqueous metal surface treatment agent, metal surface treatment film and metal material having metal surface treatment film |
| CN115182196A (en) * | 2022-07-14 | 2022-10-14 | 浙江天益塑业有限公司 | Waterproof wear-resistant paper-plastic composite bag and preparation method thereof |
| CN115182196B (en) * | 2022-07-14 | 2023-08-15 | 浙江天益塑业有限公司 | Waterproof wear-resistant paper-plastic composite bag and preparation method thereof |
| CN116356126A (en) * | 2023-03-30 | 2023-06-30 | 江苏甬金金属科技有限公司 | Ultrathin corrosion-resistant silicon steel strip and preparation method thereof |
| CN116356126B (en) * | 2023-03-30 | 2024-04-19 | 江苏甬金金属科技有限公司 | Ultrathin corrosion-resistant silicon steel strip and preparation method thereof |
| CN118087000A (en) * | 2024-04-26 | 2024-05-28 | 诸暨市中俄联合材料实验室 | Micro-arc oxidation/thermoelectric chemical oxidation method of non-valve metal |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4027848B2 (en) | 2007-12-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3844643B2 (en) | Ground treatment agent and ground treatment method | |
| Walker et al. | Molybdate based conversion coatings for zinc and zinc alloy surfaces: a review | |
| US4600447A (en) | After-passivation of phosphated metal surfaces | |
| JP3333611B2 (en) | Hexavalent chromium-free chemical conversion surface treatment agent for aluminum and aluminum alloys | |
| JP4935103B2 (en) | Surface-treated steel sheet | |
| JP4027848B2 (en) | Painted stainless steel plate with excellent corrosion resistance | |
| JP2011068996A (en) | Composition for surface treatment of metallic material, and treatment method | |
| JP2007002330A (en) | Surface treatment agent for zinc or zinc alloy galvanized steel sheet, and surface treated zinc or zinc alloy galvanized steel sheet | |
| JP3305703B2 (en) | Chemical treated steel sheet with excellent corrosion resistance | |
| JP3302684B2 (en) | Chemical treated steel sheet with excellent corrosion resistance | |
| WO2001034873A1 (en) | Organic composite coated zinc-based metal plated steel sheet | |
| KR20020036710A (en) | A chemically processed steel sheet improved in corrosion resistance | |
| JP2003293165A (en) | Welded steel pipe having excellent corrosion resistance | |
| JP2002030459A (en) | Galvanized steel sheet excellent in corrosion resistance, chemically treating solution and chemical conversion treating method | |
| JP5611128B2 (en) | Surface-treated aluminized steel sheet and its manufacturing method | |
| JP3302680B2 (en) | Steel plate with excellent corrosion resistance | |
| JP4634650B2 (en) | Welded steel pipe with excellent corrosion resistance | |
| JP4795647B2 (en) | Galvanized steel sheet with excellent corrosion resistance, paintability and adhesion | |
| JP2003213458A (en) | Cr-FREE CHEMICAL CONVERSION-TREATED ALUMINUM-BASED PLATED STEEL SHEET | |
| JP2007023309A (en) | Hot-dip zinc alloy plated steel sheet having excellent corrosion resistance | |
| JP2003293162A (en) | Coated plated steel sheet having excellent corrosion resistance | |
| JP2008163364A (en) | Chemical conversion-treated steel sheet having excellent coating film adhesive strength and film adhesion after forming | |
| JP2002105658A (en) | Galvanized steel sheet having excellent blackening resistance and corrosion resistance after working, chemically treating solution and chemical conversion treatment method | |
| JP5442346B2 (en) | Method for producing chemical conversion treated steel sheet | |
| JP5565083B2 (en) | Heat-resistant discoloration-resistant rust-proof aluminum-plated steel and its surface treatment liquid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20050204 |
|
| RD03 | Notification of appointment of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7423 Effective date: 20070411 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20070413 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20070417 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20070417 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20070508 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070628 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20070925 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20071010 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101019 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4027848 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101019 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111019 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121019 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121019 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131019 Year of fee payment: 6 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |