JP3749417B2

JP3749417B2 - electrode

Info

Publication number: JP3749417B2
Application number: JP2000008310A
Authority: JP
Inventors: 彰高安; 俊洋丸橋
Original assignee: Nippon Steel Corp
Current assignee: Nippon Steel Corp
Priority date: 2000-01-17
Filing date: 2000-01-17
Publication date: 2006-03-01
Anticipated expiration: 2020-01-17
Also published as: JP2001200397A

Description

【０００１】
【発明の属する利用分野】
本発明は、メッキその他の電気化学的処理を部材に施すために使用される電極に関する。
【０００２】
【従来の技術】
従来より、例えば鋼板にＺｎやＣｒ等の金属をメッキする技術においては、電極基材の表面を不溶性の二酸化鉛からなる導電性活物質層で覆って放電面を形成した構造の電極が使用されている。導電性活物質層はＰｔからなるものも使用できるが、二酸化鉛からなるものこれに遜色ないメッキ性能を発揮できる上に安価であり、また、Ｃｒメッキの場合には三価クロムを六価クロムに酸化する能力が大きいため、良好なＣｒメッキを行うのに好都合な利点がある。
【０００３】
【発明が解決しようとする課題】
しかしながら、二酸化鉛系の導電性活物質層は、脆い酸化物にて構成されているため、以下のような問題を生じやすい。
(1)電極基材への付着力が小さく、処理中に一部が剥離・脱落すると、例えば被処理部材と送りロールとの間に巻き込まれたりしたときに、被処理部材に押し傷等の欠陥を生じやすい。
(2)板状の電極基材を使用する場合は、導電性活物質層の基材表面への担持量をそれ程大きくすることができず、電極寿命が短くなりがちである。また、導電性活物質層の局所的な消耗がひどくなれば、メッキに寄与する放電面の消耗がそれほど進行していなくとも電極全体の交換を余儀なくされ、極めて不経済である。
（３）電極セグメントを電極基体に取り付ける構造として、板状のセグメントの表面、つまり導電性活物質層の側から取付ねじを貫通させ、これを電極基体側にねじ込む方式のものが多く使用されている。この構造の場合、電極基体の表面に取付ねじの頭部が露出するため、そこでめっき電流等が不均一化する懸念が生ずる。また、ねじ頭部の座面が噛み込んだ際に導電性活物質層の剥離等が生じやすい欠点がある。さらに、コスト低減のために、取付基体を安価な鋼製芯材にＴｉやＮｂ、Ｔａ等のライニングにて覆った電極基体構造を採用しようとすると、ねじ孔形成用の耐食性のボスを芯材に埋設する必要が生ずるなど、基体側に形成する取付ねじ部付近の構造が複雑化しやすく、また着脱を繰り返すうちに、ライニングによる密封構造が破れやすい難点がある。
【０００４】
本発明の課題は、電極基材に対し、十分な量の二酸化鉛系の導電性活物質層を強固に担持させることができ、ひいては高性能で長寿命の電極を提供すること、あるいは、電極セグメントの電極基体への取付構造が単純で着脱が容易であり、さらに着脱に際して導電性活物質層への損傷等を生じにくい構造の電極を提供することにある。
【０００５】
【課題を解決するための手段及び作用・効果】
本発明の電極の第一の構成は、
被処理部材に対向する側を表側として、該表側から裏面側へ至る液体流通部が形成された電極基体と、
電極基体に各々着脱可能に取り付けられるとともに、Ｔｉ、Ｎｂ及びＴａのいずれかからなる耐食性金属により構成された網状耐食性基材に対し、複数形成された網目の全部又は一部が貫通状態を維持する程度に、該網状耐食性基材の網目を形成する線状部分に二酸化鉛からなる導電性活物質層を担持させた構造を有し、片面が被めっき物に対向する放電面を形成するように、電極基体の表側に取り付けられる複数の電極セグメントとを備え、
網状耐食性基材の貫通状態の網目と、電極基体に形成された液体流通部とを介して、電極セグメントの放電面側と、電極基体の裏面側との間での液体の流通が許容される構造を有したことを特徴とする。
【０００６】
上記の構造によれば、電極セグメントの使用により、一部の電極セグメントに消耗や損傷等の不具合が生じたとしても、その不具合を賞した電極セグメントのみを交換すれば事足り、修復を容易に行うことができる。他方、その電極セグメントの基材（電極基材）として網状耐食性基材が使用され、その網目を形成する線状部分に二酸化鉛からなる導電性活物質層を担持させているので、導電性活物質の単位重量当りの担持面積が大きくなり、ひいては導電性活物質の電極基材への付着力を大きくすることができる。これにより、めっき等の処理中に導電性活物質の剥離・脱落等が生じにくくなる。また、導電性活物質層の基材表面への担持量も比較的大きくできるから、電極寿命を延ばすことができる。
【０００７】
なお、本発明の電極は、長手方向に搬送される鋼板ストリップ等の被処理部材の板面に対向配置し、当該被処理部材に連続的にメッキ等の電気化学的処理を行うために使用することができる。この場合、上記の第一の構成によれば、以下のような新たな効果を奏することができる。まず、電極板をセグメント分割する方法において、従来の電極では、隣接する電極セグメント間になるべく隙間が生じないよう、密に配列した形で電極基体に取り付けるようにしていた。ところが、このような電極を、例えば鋼板ストリップ等を被メッキ物とする連続メッキラインにて使用する場合、被メッキ物の速度が大きいと、電極と被めっき物との隙間内に負圧が生じ、被メッキ物が電極側に吸い寄せられて、ショートやそれに伴うメッキ不良等のトラブルを招く場合がある。また、このような不具合を解消するために、被メッキ物Ｓの送り速度を小さくすると、当然のことながらメッキ処理の能率低下を招くこととなる。
【０００８】
そこで、上記本発明の電極の第一の構成では、網状耐食性基材の貫通状態の網目と、電極基体に形成された液体流通部とを介して、電極セグメントの放電面側と、電極基体の裏面側との間での液体の流通が許容される構造を有していることから、放電面に面した状態で鋼材ストリップ等の被処理部材が高速移動して液流が発生しても、放電部材の連通部と電極基体の貫通部とを介して電極表面側と裏面側とで液体（例えばメッキ液等の電解液）が流通可能となっているので、被処理部材と電極との間に負圧が発生しにくい。その結果、負圧発生により被処理部材と電極とが吸引・接近してショート等のトラブルを招く不具合を、極めて効果的に防止することができる。また、負圧発生の心配が軽減されることから、被処理部材の送り速度を増大させることが可能となり、該電極を用いたメッキや電解酸洗等の電気化学処理の能率を大幅に向上させることができる。結果、被処理部材が高速移動するメッキラインに適用した場合でも、電極と被処理物との間の隙間に負圧が発生しにくく、ショート等のトラブルが生じにくい構造を有し、かつメッキむら等の少ない良好な処理が可能な電極が実現される。さらに、網状耐食性基材の使用により、負圧発生が生じにくくなることにより、被処理物と電極との距離を小さくすることが可能となるので、液抵抗が減ずる分だけ処理電圧が低くなり、ひいては省エネルギーを図ることができる。また、処理中に発生する水素ガスが網目を介して放出されるため付着しにくくなることも、処理電圧の低減に寄与する。
【０００９】
次に、本発明の電極の第二の構成は、
電極基体と、
被処理部材に対向する側を表側として、電極基体の表側に取り付けられるとともに、Ｔｉ、Ｎｂ及びＴａのいずれかからなる耐食性金属により構成される網状耐食性基材と、その裏面側に一体化されるとともに、Ｔｉ、Ｎｂ及びＴａのいずれかからなる耐食性金属により構成されるバックプレートと、網状耐食性基材の網目を形成する線状部分に担持される二酸化鉛からなる導電性活物質層とを有し、電極基体に取り付けられた状態において、片面が被めっき物に対向する放電面を形成する複数の電極セグメントとを備えたことを特徴とする。
【００１０】
上記の構造によれば、電極セグメントの使用により、第一の構成と同様に修復を容易に行うことができる。他方、その電極セグメントの基材として網状耐食性基材が使用されていることから、導電性活物質の単位重量当りの担持面積が大きくなり、ひいては導電性活物質の電極基材への付着力を大きくすることができる。これにより、めっき等の処理中に導電性活物質の剥離・脱落等が生じにくくなる。また、導電性活物質層の基材表面への担持量も比較的大きくできるから、電極寿命を延ばすことができる。さらに、網状耐食性基材の裏面にバックプレートを一体化することで、電極セグメントの剛性が高められ、基材変形による導電性活物質の剥離・脱落をより生じにくくすることができる。この場合、導電性活物質を、基材の網目を形成する線状部分に加え、基材が重ね合わされているバックプレート表面側にもまたがるように付着させることで、導電性活物質層の担持量をさらに増大させることができる。
【００１１】
なお、上記第二の構成においては、次の要件の少なくとも一方を、さらに付加することが可能である。これにより、前記した本発明の第二の課題も同時に解決することができる。
(1)電極基体に、被処理部材に対向する側を表側として、該表側から裏面側へ至る液体流通部を形成し、
また、バックプレートに板厚方向の貫通孔（プレート縁部や角部に切欠を形成する場合は、その切欠も広義に貫通孔とみなす）を形成し、
電極セグメントの網状耐食性基材の網目と、バックプレートの貫通孔と、電極基体に形成された液体流通部とを介して、電極セグメントの放電面側と、電極基体の裏面側との間での液体の流通が許容される構造とする。
(2)電極基体に、被処理部材に対向する側を表側として、該表側から裏面側へ至る液体流通部を形成し、
複数の電極セグメントを該電極基体に対し、互いに隣接するものの間に所定量の隙間が形成されるように取り付け、
それら電極セグメント間の隙間と、電極基体に形成された液体流通部とを介して、電極セグメントの放電面側と、電極基体の裏面側との間での液体の流通が許容される構造とする。
【００１２】
次に、本発明の電極の第三の構成は、
電極基体と、
被処理部材に対向する側を表側として、電極基体の表側に取り付けられるとともに、Ｔｉ、Ｎｂ及びＴａのいずれかからなる耐食性金属により構成される耐食性基材と、その耐食性基材の表面を覆う二酸化鉛からなる導電性活物質層とを有する電極セグメントと、
各電極セグメントの裏面側に形成されたセグメント側取付支持部と、
電極基体側に形成された基体側取付支持部と、
それらセグメント側取付支持部と基体側取付支持部とを着脱可能に結合する結合部材とを備え、電極基体から、基体側取付支持部、結合部及びセグメント側取付支持部を経て各電極セグメントに至る給電経路が形成されるとともに、電極基体は、
鋼製の芯材と、
その芯材に対し基端部が結合される形で該芯材外面から突出配置されるとともに、Ｔｉ、Ｎｂ及びＴａのいずれかからなる耐食性金属からなる基体側取付支持部と、
芯材の外面を覆うとともに、該芯材と基体側取付支持部との結合部においては、基体側取付支持部の基端部外面へまたがる形でこれを覆う、Ｔｉ、Ｎｂ及びＴａのいずれかからなる耐食性金属ライニングとを含むことを特徴とする。
【００１３】
上記の構造によれば、電極セグメントの使用により、第一の構成と同様に修復を容易に行うことができる。また、電極セグメントの裏面側に形成されたセグメント側取付支持部と、電極基体側に形成された基体側取付支持部とを、結合部材により着脱可能に結合する構造であるから、電極セグメントを貫通する取付ねじ等が存在せず、構造が簡単である。他方、導電性活物質層にて形成される放電面にねじ頭部等が露出しないため、セグメントの表面側のすべてを放電面として活用することが可能であり、めっき電流の不均一化等も生じにくい。さらに、ねじ頭部の座面の噛み込み等による導電性活物質層の剥離といった不具合も懸念する必要がなくなる。さらに、電極基体において、芯材の外面を覆う耐食性金属ライニングが、該基体に突設された基体側取付支持部の基端部を、その外面にまたがる形にて覆っていることから、鋼製の芯材のライニングによる密封状態を良好に保つことができ、電極セグメントの着脱を繰り返してもその密封構造が破れにくい。この場合、基体側取付支持部の表面の、結合部材の結合位置は耐食性金属ライニングに覆われないようにしておけば、さらに効果的である。
【００１４】
なお、上記本発明の電極の第三の構成には、前記の第一の構成及び第二の構成の少なくともいずれかを組み合わせることができる。
【００１５】
【発明の実施の形態】
以下、本発明の実施の形態を図面に示す実施例を参照して説明する。
図１は、本発明の一実施例たる電極２０１の正面図を、平面図及びＡ−Ａ及びＢ−Ｂの両断面図とともに表したものである。該電極２０１は、電極基体２０２を備え、これに複数の電極セグメント２１１，２５０を取り付けた構造を有する。電極セグメント２１１，２５０は、図５に示すように、Ｔｉ、Ｎｂ及びＴａのいずれかからなる網状耐食性基材２３０の表面を二酸化鉛からなる導電性活物質層２３１により覆った構造を有している。電極セグメント２１１，２５０においては、上記の導電性活物質層２３１が放電面を形成する。導電性活物質層２３１の厚さは、例えば５０μｍ〜５ｍｍ程度（本実施例では８００μｍ程度）である。
【００１６】
図２に概念的に示すように、上記の電極２０１は、電解液としてのメッキ液ＳＬ中を、長手方向に連続搬送される被処理部材としての鋼材ストリップＳＳに対し、被メッキ面（この実施例では両面）となる板面に放電面が対向する形で配置される。また、電解液Ｌへの浸漬部分において鋼材ストリップＳＳと対向する側に、放電面を形成する電極セグメント２１１，２５０（図１）が配置される。そして、電極側をアノード、鋼材ストリップ側をカソードとしてメッキ液ＳＬを介して通電することにより、メッキ液ＳＬ中の金属カチオンが鋼材ストリップＳＳの表面に析出し、連続メッキ処理されることとなる。なお、鋼材ストリップＳＳは、送りロール５１あるいはガイドロール５０等によりメッキ液ＳＬ中を搬送される。本実施例では、鋼材ストリップＳＳを長手方向に連続搬送しつつ、これに電解液Ｌからなるメッキ浴によりクロムメッキを施す場合を例にとっており、メッキ浴として、メッキ効率を向上させるため、ケイフッ化ナトリウムを配合したフッ化物浴が使用されている。
【００１７】
電極２０１において、網状耐食性基材２３０をＴｉ、Ｎｂ及びＴａの１種又は２種以上からなる耐食性金属で構成するのは、これらの金属がメッキ液等の電解液による腐食への耐性に優れているためである。なお、上記耐食性金属は、Ｔｉ、Ｎｂ及びＴａの１種又は２種以上（例えばＮｂとＴａとの２種）からなる主成分金属元素の含有率が５０重量％以上、望ましくは７０重量％以上であることが、耐食性確保の観点で望ましい。
【００１８】
電極２０１をＣｒメッキに適用する場合、メッキ液として前記のフッ化物浴を使用することが望ましいが、このようなフッ素を含有したメッキ液を使用する際には、耐食性金属として特に、ＮｂあるいはＴａを主成分とするものを選定することが望ましい。この実施例では、網状耐食性基材２３０が例えばＮｂの網材で構成され、図５に示すように、その網目２１１ｐを形成する線状部分に、二酸化鉛からなる導電性活物質層２３１を担持させている。このような導電性活物質層２３１は、例えば網状耐食性基材２３０上に硝酸鉛浴あるいは一酸化鉛浴から電着させる方法により形成することができる。なお、導電性活物質層２３１の密着性を高めるために、Ｐｔ、Ｉｒ、Ｒｕ等のＰｔ族金属又はそれらの酸化物からなる下地層を形成してもよい。
【００１９】
網状耐食性基材２３０による導電性活物質層２３１の担持状態は、図６に示すように、複数形成された網目２１１ｐの全部又は一部が貫通状態を維持する程度、換言すれば、電着等により成長する導電性活物質層２３１が、網目２１１ｐのすべてを塞がず、液流通を許容する程度の貫通孔２３１ａを残留させる程度のものとされている。導電性活物質層２３１は網目面内方向に成長しやすいが、各網目の導電性活物質層２３１による閉塞面積率は、例えば１％〜５０％程度とするのがよい。また、網状耐食性基材２３０とこれに担持させた導電性活物質層２３１とからなる電極セグメント２１１（あるいは２５０）の開口面積率は、０．０３〜０．５、望ましくは０．１〜０．３５に調整するのがよい。他方、例えば静止めっきの場合のように、負圧発生抑制を目的とした液流通を特に考慮する必要がない場合においては、各網目の導電性活物質層２３１による閉塞面積率や電極セグメント２１１（あるいは２５０）の開口面積率は、上記数値範囲の下限値よりもさらに小さくなっていてもよい。
【００２０】
網状耐食性基材２３１は、この実施例では図６に示すように、板厚方向に貫通する複数の切れ目が全面に千鳥状に形成された耐食性金属板を、その切れ目の形成方向と交差する向きに変形させ、切れ目をその変形方向に開口することにより菱形状の網目が形成されたものが使用されている。これは、いわゆるエキスパンドメタルと称されるもので、板状の素材に切れ目を入れて引き伸ばすことにより比較的安価に製造できる利点がある。また、二酸化鉛からなるするやや脆い導電性活物質層２３１を担持させる上で、以下のような特有の利点がある。すなわち、線材を編み合わせて製造した通常の網材の場合、縦横の線材は交差位置において本質的に非結合であり、温度変化に曝された際の膨張・収縮により微量ではあるが互いに摺動する。このような摺動が繰り返されると、線材の交差位置において担持されている導電性活物質層にクラック等が生じやすくなり、ひいては電性活物質層２３１の剥離・脱落が生じやすくなる場合がある。しかしながら、上記のようなエキスパンドメタルでは、網目を形成する線状部分がすべて一体不可分に結合されているので、上記のような不具合が生じにくい。
【００２１】
なお、菱形状の網目の間隔Ｄを、その長対角線の寸法Ｔと短対角線の寸法Ｓとの平均値（≡（Ｔ＋Ｓ）／２）で定義したときに、該Ｄは１．５〜５０ｍｍに調整されているのがよい。Ｄが１．５ｍｍ未満では液流通効果が不十分となる。逆に５０ｍｍを超えると、放電表面積を十分に確保することが困難となり、導電性活物質層の消耗が加速されて寿命が尽きやすくなる場合がある。Ｄは、さらに望ましくは２〜２４ｍｍに調整されているのがよい。一方、網目を形成する線状部分の断面径（線状部分の、長手方向におけるほぼ中央位置での軸断面の円換算径を断面径として定義する）は、０．３〜３ｍｍに調整されているのがよい。断面径が０．３ｍｍ未満では網状耐食性基材としての強度確保が困難となり、断面径が３ｍｍを超えると、液流通効果を十分達成するには網目間隔Ｄを相当大きくしなければならず、電流密度が過剰になりやすくなる。
【００２２】
次に、図１に示すように電極基体２０１には、電極セグメント２１１が取り付けられている表側から、裏面側へ至る液体流通部２３５が形成されている。ここでは電極基体２０１はフレーム状に形成されており、表層部のみをＮｂ又はＴａからなる耐食性金属により構成している。
【００２３】
具体的には電極基体２０２は、電極２０１の幅方向両側において縦方向に互いに略平行に配置された縦フレーム２０２ａ，２０２ａの上端部同士を、横フレーム２０２ｂにより連結した、略コの字状の本体部２０２ｍを有する。縦フレーム２０２ａ，２０２ａには、縦方向に所定の間隔で並ぶ横長梁状の電極セグメント支持体２０４の両端部がそれぞれ取り付けられている。そして、それら電極セグメント支持体２０４の間に形成される隙間が液体流通部２３５とされている。
【００２４】
一方、横フレーム２０２ｂの長手方向中間部には、縦長の懸架支持部２０２ｃ，２０２ｃの下端側が結合される一方、それら懸架支持部２０２ｃ，２０２ｃの上端部には、横方向の給電部２０３が結合されており、その一方の端部に受電用の端子部２０３ａが形成されている。また、懸架支持部２０２ｃ，２０２ｃの裏側には、図示しない電極支持梁等に電極２０２を懸架するためのフック２０２ｄ，２０２ｄが設けられている。
【００２５】
電極基体２０２の本体部２０２ｍ、電極セグメント支持体２０４、懸架支持部２０２ｃ，２０２ｃ、給電部２０３（端子部２０３ａは除く）は、いずれも表層部のみを前述の耐食性金属にて構成する態様として、炭素鋼などの鋼材からなる芯材の表面を耐食性金属ライニング（以下、単にライニングともいう）により覆った構造を有している。電極セグメント支持体２０４を例にとれば、図５に示すように、耐食性金属（Ｔｉ、Ｎｂ及びＴａのいずれかからなるもの：例えばＮｂ）の薄板からなるライニング２２６により芯材２０４ａ，２０４ｂの周囲を覆い、ライニング２２６の継ぎ目部分を図示しない溶接部により封止・密封した構成としている。
【００２６】
ここでは、電極セグメント２５０，２１１の取り付けのため、基体側取付支持部としての横長の基体側取付プレート（これも耐食性金属からなる）２０５を、厚さ方向に分割された芯材２０４ａ，２０４ｂの間に挟み込み、第一分割芯材２０４ｂの側から基材側取付プレート２０５を貫いて第二分割芯材２０４ａにボルト２２２をねじ込むことにより、これらを一体的に結合している。そして、第一分割芯材２０４ｂに形成した座ぐり部２０４ｃにボルト２２２の頭部２２２ａを収容して外側を周方向にライニング２２６により包み、該ライニング２２６の縁を基材側取付プレート２０５の基端部の両面にそれぞれ溶接封着している。その結果、芯材２０４ａ，２０４ｂの外面が耐食性金属ライニング２２６にて覆われるとともに、芯材２０４ａ，２０４ｂと基体側取付支持部（基体側取付プレート）２０５との結合部において、ライニング２２６が基体側取付支持部２０５の基端部外面へまたがる形でこれを覆う構造が実現されている。
【００２７】
電極セグメント２１１，２５０は、電極基体２０２に対し、少なくとも表層部がＮｂ又はＴａからなる耐食性金属にて構成された結合部材２７０により、着脱可能に取り付けられる。この実施例では、横長の耐食性金属板材を幅方向中間位置にてＬ字状断面となるように曲げ、その片側をセグメント２１１，２５０の裏面側幅方向に固着してセグメント側取付支持部２３６を形成している。そして、そのセグメント側取付部２３６を基体側取付プレート（基体側取付支持部）２０５に重ね合せ、それらを貫通するボルト２２３にナット２２４（いずれも耐食性金属にて構成されている）を螺合・締結する。すなわち、これらボルト２２３及びナット２２４が結合部材２７０を構成する。なお、基体側取付プレートのボルト２２３の挿通孔２０５ｈ（すなわち、結合部材２７０の結合位置）は耐食性金属ライニング２２６により覆われていない。また、符号２２５，２２５は耐食性金属製のワッシャである。
【００２８】
上記電極２０１は、図２に示すように、メッキ浴中にて被メッキ物たる金属ストリップ（例えば鋼板ストリップ）ＳＳを長手方向に搬送しつつ、その金属ストリップＳＳの片面に主放電面２４０を対向させてこれにメッキを施すメッキ用電極として使用される。このとき、電極基体２０６から、基体側取付支持部２０５、結合部２７０及びセグメント側取付支持部２３６を経て各電極セグメント２１１，２５０に至る給電電経路が形成される。図３に示すように、電極セグメント２５０は金属ストリップＳＳの送り方向に複数枚配列されており、電極セグメント２１１は金属ストリップＳＳの送り方向及び幅方向にそれぞれ複数枚配列されている。
【００２９】
また、金属ストリップＳＳの送り方向に生ずる電極セグメント２５０及び電極セグメント２１１の突き合わせ縁部（符号２５０ｉあるいは２１１ｓ）は、該送り方向に対して傾斜して形成している。上記ような突き合わせ縁部は、メッキ電流密度がやや不均一になりやすい部分であるが、金属ストリップＳＳの送り方向に対してこれを傾けることで、ストリップ幅方向においてメッキ電流密度の不均一部の位置が常に同じとなる不具合が解消され、ひいては均一なメッキを行う上で有利となる。
【００３０】
なお、電極セグメント交換を行う際には、被交換セグメントの電極上の位置により形状や大きさが異なっていたのでは、多数の種類の予備電極セグメントを用意する必要が生じて不経済であるし、また、予備を備えていない形状のセグメントに不具合が生じた場合には、修復を即時に行えない問題も生ずる。従って、全ての電極セグメントの形状及び大きさが同一となるようにすることが有利であるといえる。そして、上記のような傾斜した突き合わせ縁部を形成する場合は、少なくとも電極セグメント２１１に関しては、図３に示す通り、略同一寸法及び略同一形状の平行四辺形状に形成しておくことが望ましい。この場合、その第一対辺２１１ｐ，２１１ｐが金属ストリップＳＳの幅方向に沿って位置し、第二対辺２１１ｓ，２１１ｓが金属ストリップＳＳの送り方向に対して傾斜した突き合わせ縁部を形成するように配列されることとなる。
【００３１】
他方、電極セグメント２５０に関しては、電極セグメント２１１と同様の平行四辺形上に形成してもよいが、電極幅方向両側における副放電面２５０の縁を直線状に揃えるためには、図３に示す通り、以下のような構成とすることが望ましい。すなわち、各電極セグメント２５０を、略同一寸法及び略同一形状を有するとともに、第一対辺２５０ｐ，２５０ｐが互いに略平行であり、かつ第二対辺の一方が第一対辺２５０ｐ，２５０ｐと略直交する直交縁２５０ｖであり、他方が第一対辺２５０ｐ，２５０ｐと斜交する斜交縁２５０ｉである台形状に形成する。そして、その斜交縁２５０ｉが電極セグメント２１１の第二対辺２１１ｓとの間に傾斜した突き合わせ縁部を形成するように配置する。このようにすることで、突き合わせ縁部が傾斜しているにも拘わらず、全体が方形の電極放電面を、電極セグメント２５０，２１１により合理的に埋め尽くすことができる。なお、図４に示すように、電極セグメント２１１と電極セグメント２５０との突き合わせ縁部は、金属ストリップＳＳの幅方向において千鳥状に分散形成することもできる。ここでは、各セグメント２５０，２１１は長方形状に形成されている。
【００３２】
上記電極２０１によれば、電極セグメント２１１，２５０の網状耐食性基材２３０の網目を形成する線状部分に、二酸化鉛からなる導電性活物質層２３１を担持させているので、導電性活物質２３１の単位重量当りの担持面積を大きくできる。その結果、導電性活物質２３１の基材への付着力が大きくなり、導電性活物質の剥離・脱落等が生じにくくなる。また、導電性活物質２３１の基材表面への担持量も比較的大きくできるから、電極寿命を延ばすことができる。他方、図５に破線の矢印にて示す通り、網状耐食性基材２３０の貫通状態の網目２１１ｐ（２３１ａ）と、電極基体側の液体流通部２３５とを介して、電極セグメント２１１（２５０）の放電面側と、電極基２０６の裏面側との間での液体の流通が許容される。その結果、図２において、放電面に面した状態で鋼材ストリップＳＳが高速移動して液流が発生しても、上記液体の流通により鋼材ストリップＳＳと電極２０６との間に負圧が発生しにくい。その結果、負圧発生により鋼材ストリップＳＳと電極２０６とが吸引・接近してショート等のトラブルを招く不具合を効果的に防止することができる。また、電極セグメント２１１，２５０に消耗や損傷等の不具合が生じたときは、損傷等の生じた電極セグメントのみを交換すれば事足り、修復を容易に行うことができる。
【００３３】
図７は電極セグメントの変形例を示すものである（図５と共通の部分には同一の符号を付与して詳細な説明を省略する）。該電極セグメント２６０では、網状耐食性基材２３０の裏面に、前記の耐食性金属からなるバックプレート２４０が一体化されている。これにより、電極セグメント２１１，２５０の剛性を高めることができる。この実施例では網状耐食性基材２３０は、スポット溶接により複数箇所にてバックプレート２４０に固着されている。また、セグメント側取付支持部２３６は、スポット溶接によりバックプレート２４０の裏面側に結合されている。なお、導電性活物質層２３１は、基材２３０によるその担持量を増加させるため、網状耐食性基材２３０の線状部分に加え、バックプレート２４０の表面側にもまたがるように付着させることができる。
【００３４】
図８及び図９に示すように、バックプレート２４０には、前記した液流通を確保するために、これを板厚方向に貫通する貫通孔を形成することができる。図８は、角状の貫通孔２４０ｈをマトリックス状に配列・形成した例である。他方、図９は、網状耐食性基材２３０の網目に対応する形で丸孔状の貫通孔２４０ｈを形成した例である。
【００３５】
なお、鋼材ストリップＳＳの吸付き等が特に問題とならない場合（鋼板ストリップＳＳの搬送速度が小さい場合など）は、前記した液流通を確保する必要は特になく、バックプレート２４０は、貫通孔を有さない板材として構成することもできる。一方、貫通孔を有さない板材にてバックプレート２４０を構成しつつも、液流通を確保したい場合は、図１０に示すように、メッキむら等の不具合を生じない範囲にて、電極セグメント２１１，２５０の互いに隣接するものの間に所定量の隙間Ｇが形成されるように取り付け、この隙間Ｇを介して液流通させるようにしてもよい。隙間Ｇは、電極セグメント２１１，２５０のすべての隣接縁間に形成する必要性は必ずしもなく、例えば図１０に示すように、メッキむら等への影響が少ない、鋼材ストリップＳＳの搬送方向と交差する向きの縁間のみに形成することもできる。
【００３６】
以下、参考発明について説明する。
鋼板ストリップの全面に連続メッキを均一に施すためには、鋼板ストリップの被メッキ面が電極の放電面に完全に包含されるように、放電面を鋼板ストリップの幅よりも若干大きく設定するのが常である。しかしながら、鋼板ストリップの通板領域の外側に位置する放電面形成部（以下、通板外領域という）は、基本的にはメッキ進行に寄与しないため放電面よりも電位が下がってカソード化し、結果とて導電性活物質層からなる放電面が、この通板外領域で消耗しやすくなる欠点がある。例えば広幅の鋼板ストリップにワークを段取り替えすれば、新しいワークの幅方向両縁部が前のワークの通板外領域にかかる形となることもありえるが、その通板外領域での消耗が進行しすぎていると、めっき不良等の不具合を引き起こすこともありえる。また、電極板全体が一体に形成されている場合に生ずる問題として、通板外領域での消耗が過度に進行したときに、メッキに寄与する放電面の消耗がそれほど進行していなくとも電極の交換を余儀なくされ、極めて不経済となることも挙げられる。
【００３７】
上記の問題を解決するためには、以下のような電極の構成が有効である。すなわち、該電極は、
電極基体と、
Ｔｉ、Ｎｂ及びＴａのいずれかからなる耐食性下地板の表面を二酸化鉛からなる導電性活物質層により覆った構造を有し、その導電性活物質層が表となるように電極基体に取り付けられるとともに、該導電性活物質層により主放電面を形成する主電極板と、
主電極板とは別体に形成され、Ｔｉ、Ｎｂ及びＴａのいずれかからなる耐食性下地板の表面をＰｔ族金属からなる貴金属系被覆層により覆った構造を有し、記副放電面の幅方向両側において電極基体に貴金属系被覆層が表となるように電極基体に取り付けられるとともに、該貴金属系被覆層により副放電面を形成する副電極板と、
を備えたことを特徴とする。
【００３８】
例えば、被メッキ物たる金属ストリップを長手方向に搬送しつつ、その金属ストリップの片面に主放電面を対向させてこれにメッキを施すメッキ用電極として使用する場合、通板外領域では前述のカソード化により消耗が進行しやすい環境に曝される。そこで、この通板外領域となる、主放電面の幅方向両側に隣接する放電面部分を、Ｐｔ族金属からなる貴金属系被覆層からなる上記の副放電面として形成することで、当該副放電面における消耗を極めて効果的に防止ないし抑制することが可能となる。
【００３９】
上記のような電極の一例は、図１と同様の形態を有するものとして構成できるが、この場合、電極セグメントを例えば図１１に示すように配置することができる。この例では、鋼板ストリップＳＳの通板領域に対応する電極セグメントとしては、図１等に示すものと同様のものを主放電セグメント（主電極板）２１１として採用する。主放電セグメント２１１は、上記の鉛系被覆層２３１により主放電面３４０を形成する。他方、通板外領域に位置するものは、図１の電極セグメント２１１に代え、以下のような構成を有するものを副放電セグメント（副電極板）２１０として採用する。
【００４０】
すなわち、副電極セグメント２１０は、図１２に示すように、Ｔｉ、Ｎｂ及びＴａのいずれかからなる耐食性下地板２２０の表面をＰｔ族金属（例えばＰｔ）からなる貴金属系被覆層２２１により覆った構造を有する（図５と共通の部分には同一の符号を付与して詳細な説明を省略する）。そして、主放電面３４０（図１１）の幅方向両側において電極基体２０２に貴金属系被覆層２２１が表となるように電極基体に取り付けられる。図１１に示すように、副電極セグメント２１０は、上記の貴金属系被覆層２２１により副放電面３５０を形成する。貴金属系被覆層２２１の厚さは、例えば１〜４００μｍ程度（本実施例では４．５μｍ程度）である。貴金属系被覆層２２１は、例えば耐食性下地板２３０にＰｔ、Ｉｒ、Ｒｕ等のＰｔ族金属のメッキを施すことにより形成できるが、これら金属の薄板を耐食性下地板に圧着（あるいは溶接）したクラッド板を使用することもできる（この実施例ではＰｔ箔のクラッド）。
【００４１】
上記のような副放電面３５０を、貴金属系被覆層にて形成することにより、該副放電面３５０における消耗を効果的に防止ないし抑制することができる。また、仮に副放電面３５０に消耗や損傷等の不具合が生じたとしても、副放電面３５０を形成する副電極セグメント２１０が、主放電面３４０を形成する主電極セグメント２１１とは別体に形成されていることから、副電極セグメント２１０のみを交換すれば事足り、修復を容易に行うことができる。
【図面の簡単な説明】
【図１】本発明の電極の一実施例を示す正面図、平面図、底面図及び側面図。
【図２】図１の電極の使用形態の一例を示す模式図。
【図３】図１の電極における電極セグメントの配置形態を抽出して示す正面図。
【図４】電極セグメントの形状及び配置形態の変形例を示す正面図。
【図５】図１の電極セグメントの電極基体への取付け構造の一例を示す側面断面図。
【図６】網状耐食性基材の拡大正面図。
【図７】バックプレートを有する電極セグメントの一例を、その取付け構造とともに示す側面断面図。
【図８】バックプレートへの貫通孔の形成形態の一例を示す模式図。
【図９】同じくその変形例を示す模式図。
【図１０】隣接する電極セグメント間に隙間を形成する例を示す正面図。
【図１１】参考発明における電極セグメントの配置形態の一例を示す正面図。
【図１２】図１１の電極セグメントの、電極基体への取付構造の一例を示す側面断面図。
【符号の説明】
２０１電極
２０２電極基体
２０５基材側取付プレート（基材側取付支持部）
２１１，２５０電極セグメント
２１１ｐ網目
２３０網状耐食性基材
２３１導電性活物質層
２３１ａ貫通孔
２３５液体流通部
２３６セグメント側取付支持部
２４０主放電面
２５０副放電面
２７０結合部材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrode used for applying plating or other electrochemical treatment to a member.
[0002]
[Prior art]
Conventionally, for example, in the technology of plating a metal such as Zn or Cr on a steel plate, the surface of the electrode substrate is made of insoluble lead dioxide. Consist of An electrode having a structure in which a discharge surface is formed by covering with a conductive active material layer is used. The conductive active material layer is Pt Consist of Can also be used, but lead dioxide Consist of In addition to being able to exhibit plating performance comparable to this, it is inexpensive, and in the case of Cr plating, it has a great ability to oxidize trivalent chromium to hexavalent chromium, so it is advantageous for performing good Cr plating There is.
[0003]
[Problems to be solved by the invention]
However, lead dioxide-based conductive active material layers are brittle oxides. Consists of Therefore, the following problems are likely to occur.
(1) If the adhesion to the electrode substrate is small and part of it peels off during processing, for example when it is caught between the member to be processed and the feed roll, a defect such as a scratch will occur on the member to be processed. Cheap.
(2) When using a plate-shaped electrode substrate, the amount of the conductive active material layer supported on the substrate surface cannot be increased so much, and the electrode life tends to be shortened. In addition, if the conductive active material layer is locally consumed, the entire surface of the electrode must be replaced even if the discharge surface contributing to plating is not so much consumed, which is extremely uneconomical.
(3) As a structure for attaching the electrode segment to the electrode base, a structure in which a mounting screw is penetrated from the surface of the plate-like segment, that is, the conductive active material layer side, and screwed into the electrode base is often used. Yes. In the case of this structure, since the head of the mounting screw is exposed on the surface of the electrode base, there is a concern that the plating current or the like becomes nonuniform there. Further, there is a drawback that the conductive active material layer is likely to be peeled off when the seating surface of the screw head is bitten. Furthermore, in order to reduce the cost, if an electrode base structure in which the mounting base is covered with an inexpensive steel core with a lining of Ti, Nb, Ta or the like is adopted, a corrosion-resistant boss for forming screw holes is used as the core. The structure near the mounting screw portion formed on the substrate side is likely to be complicated, and the sealing structure due to the lining is likely to be broken while it is repeatedly attached and detached.
[0004]
An object of the present invention is to provide a sufficient amount of a lead dioxide-based conductive active material layer on an electrode base material, thereby providing a high-performance and long-life electrode, or an electrode An object of the present invention is to provide an electrode having a structure in which a segment is simply attached to an electrode substrate and can be easily attached and detached, and a conductive active material layer is not easily damaged when attached or detached.
[0005]
[Means for solving the problems and actions / effects]
The first configuration of the electrode of the present invention is:
An electrode base on which a liquid circulation part extending from the front side to the back side is formed with the side facing the member to be processed as the front side;
Attached to the electrode substrate in a detachable manner, and any one of Ti, Nb and Ta Consist of Lead dioxide is formed on the linear portions forming the mesh of the mesh-like corrosion-resistant substrate to the extent that all or a part of the mesh formed in the mesh-like corrosion-resistant substrate made of a corrosion-resistant metal maintains a penetrating state. Consist of A plurality of electrode segments attached to the front side of the electrode base so as to form a discharge surface opposite to the object to be plated, having a structure carrying a conductive active material layer;
The liquid is allowed to flow between the discharge surface side of the electrode segment and the back side of the electrode substrate through the mesh in the state of penetration of the mesh-like corrosion-resistant substrate and the liquid circulation part formed on the electrode substrate. It has a structure.
[0006]
According to the above structure, even if a defect such as wear or damage occurs in some electrode segments due to the use of the electrode segment, it is sufficient to replace only the electrode segment that has won the defect, and the repair is facilitated. be able to. On the other hand, a net-like corrosion-resistant base material is used as the base material (electrode base material) of the electrode segment, and lead dioxide is formed on the linear portions forming the mesh. Consist of Since the conductive active material layer is carried, the carrying area per unit weight of the conductive active material is increased, and as a result, the adhesion force of the conductive active material to the electrode substrate can be increased. This makes it difficult for the conductive active material to peel off or fall off during the treatment such as plating. In addition, since the amount of the conductive active material layer supported on the substrate surface can be made relatively large, the electrode life can be extended.
[0007]
The electrode of the present invention is disposed to face the plate surface of a member to be processed such as a steel strip conveyed in the longitudinal direction, and is used to continuously perform electrochemical processing such as plating on the member to be processed. be able to. In this case, according to said 1st structure, there can exist the following new effects. First, in the method of dividing the electrode plate into segments, the conventional electrodes are attached to the electrode substrate in a closely arranged manner so that there is no gap between adjacent electrode segments. However, when such an electrode is used in a continuous plating line using a steel strip or the like as the object to be plated, if the speed of the object to be plated is large, a negative pressure is generated in the gap between the electrode and the object to be plated. In some cases, the object to be plated is attracted to the electrode side, causing troubles such as a short circuit or a defective plating. Further, if the feeding speed of the object to be plated S is reduced in order to solve such a problem, the efficiency of the plating process is naturally reduced.
[0008]
Therefore, in the first configuration of the electrode of the present invention described above, the discharge surface side of the electrode segment and the electrode substrate through the mesh in the penetration state of the mesh-like corrosion-resistant substrate and the liquid circulation part formed on the electrode substrate. Since it has a structure that allows the liquid to flow between the back side and the member to be treated such as a steel strip moving at a high speed while facing the discharge surface, a liquid flow occurs. Since a liquid (for example, an electrolytic solution such as a plating solution) can be circulated between the electrode surface side and the back surface side through the communicating part of the discharge member and the penetrating part of the electrode substrate, the gap between the member to be processed and the electrode Negative pressure is unlikely to occur. As a result, it is possible to very effectively prevent the problem that the member to be processed and the electrode are sucked and approached due to the generation of the negative pressure and cause a trouble such as a short circuit. Moreover, since the concern about the occurrence of negative pressure is reduced, it becomes possible to increase the feed speed of the member to be processed, and greatly improve the efficiency of electrochemical processing such as plating and electrolytic pickling using the electrode. be able to. As a result, even when applied to a plating line in which the member to be processed moves at high speed, negative pressure does not easily occur in the gap between the electrode and the object to be processed, and a structure such as a short circuit is not likely to occur. Thus, an electrode that can be processed satisfactorily with less is realized. Furthermore, the use of the reticulated corrosion-resistant base material makes it difficult for negative pressure to occur, so the distance between the object to be processed and the electrode can be reduced, so that the processing voltage is reduced by the amount the liquid resistance is reduced, As a result, energy can be saved. In addition, since hydrogen gas generated during the treatment is released through the mesh, it is difficult to adhere, which contributes to a reduction in the treatment voltage.
[0009]
Next, the second configuration of the electrode of the present invention is as follows.
An electrode substrate;
It is attached to the front side of the electrode substrate with the side facing the member to be processed as the front side, and any one of Ti, Nb and Ta Consist of A reticulated corrosion-resistant substrate made of a corrosion-resistant metal and integrated with the back side thereof, and one of Ti, Nb and Ta Consist of Lead plate supported on the back plate composed of corrosion-resistant metal and the linear part that forms the mesh of the mesh-like corrosion-resistant substrate Consist of It has a conductive active material layer, and has a plurality of electrode segments that form a discharge surface on one side facing an object to be plated when attached to an electrode substrate.
[0010]
According to the above structure, the repair can be easily performed by using the electrode segments as in the first configuration. On the other hand, since a net-like corrosion-resistant substrate is used as the substrate of the electrode segment, the carrying area per unit weight of the conductive active material is increased, and consequently the adhesion of the conductive active material to the electrode substrate is increased. Can be bigger. This makes it difficult for the conductive active material to peel off or fall off during the treatment such as plating. In addition, since the amount of the conductive active material layer supported on the substrate surface can be made relatively large, the electrode life can be extended. Furthermore, by integrating the back plate on the back surface of the net-like corrosion-resistant substrate, the rigidity of the electrode segment can be increased, and the conductive active material can be less likely to be peeled off or dropped due to the deformation of the substrate. In this case, the conductive active material is added to the linear portion forming the mesh of the base material, and attached so as to straddle the back plate surface side on which the base material is superimposed, thereby supporting the conductive active material layer. The amount can be further increased.
[0011]
In the second configuration, at least one of the following requirements can be further added. Thereby, the above-described second problem of the present invention can be solved at the same time.
(1) On the electrode base, the liquid flow part extending from the front side to the back side is formed on the side facing the member to be processed as the front side.
Also, a through-hole in the plate thickness direction is formed in the back plate (when a notch is formed in the edge or corner of the plate, the notch is also regarded as a through-hole in a broad sense)
Between the discharge surface side of the electrode segment and the back surface side of the electrode substrate through the mesh of the electrode-like network corrosion-resistant substrate, the through hole of the back plate, and the liquid circulation part formed in the electrode substrate. The structure allows the liquid to flow.
(2) In the electrode base, the side facing the member to be processed is the front side, and a liquid circulation part extending from the front side to the back side is formed,
A plurality of electrode segments are attached to the electrode base so that a predetermined amount of gap is formed between adjacent ones,
The structure allows the liquid to flow between the discharge surface side of the electrode segment and the back surface side of the electrode substrate through the gap between the electrode segments and the liquid circulation part formed on the electrode substrate. .
[0012]
Next, the third configuration of the electrode of the present invention is:
An electrode substrate;
It is attached to the front side of the electrode substrate with the side facing the member to be processed as the front side, and any one of Ti, Nb and Ta Consist of Corrosion-resistant substrate composed of corrosion-resistant metal and lead dioxide covering the surface of the corrosion-resistant substrate Consist of An electrode segment having a conductive active material layer;
A segment side mounting support portion formed on the back side of each electrode segment;
A base-side mounting support portion formed on the electrode base side;
The segment-side mounting support portion and the base-side mounting support portion are detachably coupled to each other, and each electrode segment extends from the electrode base to the base-side mounting support portion, the coupling portion, and the segment-side mounting support portion. While the feeding path is formed, the electrode base is
A steel core,
The base end portion is coupled to the core material so as to protrude from the outer surface of the core material, and any one of Ti, Nb and Ta Consist of A base-side mounting support made of a corrosion-resistant metal;
Any one of Ti, Nb, and Ta covering the outer surface of the core material and covering the outer surface of the base side mounting support portion at the joint portion between the core material and the base side mounting support portion. Consist of And a corrosion-resistant metal lining.
[0013]
According to the above structure, the repair can be easily performed by using the electrode segments as in the first configuration. In addition, since the segment side mounting support part formed on the back side of the electrode segment and the base side mounting support part formed on the electrode base side are detachably connected by a connecting member, the electrode segment penetrates. There are no mounting screws or the like, and the structure is simple. On the other hand, since the screw heads are not exposed on the discharge surface formed by the conductive active material layer, it is possible to use all of the surface side of the segment as the discharge surface, and uneven plating current etc. Hard to occur. Furthermore, there is no need to worry about problems such as peeling of the conductive active material layer due to biting of the seating surface of the screw head. Furthermore, in the electrode base, the corrosion-resistant metal lining covering the outer surface of the core material covers the base end portion of the base-side mounting support portion projecting from the base so as to straddle the outer surface. Therefore, even if the electrode segment is repeatedly attached and detached, the sealing structure is not easily broken. In this case, it is more effective if the coupling position of the coupling member on the surface of the base-side mounting support portion is not covered with the corrosion-resistant metal lining.
[0014]
The third configuration of the electrode of the present invention can be combined with at least one of the first configuration and the second configuration.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings.
FIG. 1: shows the front view of the electrode 201 which is one Example of this invention with the top view and both the sectional views of AA and BB. The electrode 201 includes an electrode base 202 and has a structure in which a plurality of electrode segments 211 and 250 are attached thereto. As shown in FIG. 5, the electrode segments 211 and 250 are either Ti, Nb, or Ta. Consist of The surface of the net-like corrosion resistant substrate 230 is lead dioxide. Consist of It has a structure covered with a conductive active material layer 231. In the electrode segments 211 and 250, the conductive active material layer 231 forms a discharge surface. The thickness of the conductive active material layer 231 is, for example, about 50 μm to 5 mm (in this embodiment, about 800 μm).
[0016]
As conceptually shown in FIG. 2, the electrode 201 has a plating surface (this embodiment) with respect to a steel strip SS as a member to be treated that is continuously conveyed in the longitudinal direction in the plating solution SL as an electrolytic solution. In the example, the discharge surface is arranged so as to face the plate surface which is a double-sided surface. Further, electrode segments 211 and 250 (FIG. 1) that form discharge surfaces are disposed on the side facing the steel strip SS in the portion immersed in the electrolytic solution L. Then, by supplying current through the plating solution SL with the electrode side serving as an anode and the steel material strip side serving as a cathode, the metal cations in the plating solution SL are deposited on the surface of the steel material strip SS and are continuously plated. The steel strip SS is conveyed in the plating solution SL by the feed roll 51 or the guide roll 50. In this embodiment, a case where the steel strip SS is continuously conveyed in the longitudinal direction and is subjected to chrome plating with a plating bath made of the electrolytic solution L is used as an example. A fluoride bath containing sodium is used.
[0017]
In the electrode 201, the mesh-like corrosion-resistant substrate 230 is made of one or more of Ti, Nb and Ta. Consist of The reason why it is made of a corrosion-resistant metal is that these metals are excellent in resistance to corrosion by an electrolytic solution such as a plating solution. In addition, the content of the main component metal element composed of one or more of Ti, Nb and Ta (for example, two of Nb and Ta) is 50% by weight or more, desirably 70% by weight or more. It is desirable from the viewpoint of ensuring corrosion resistance.
[0018]
When the electrode 201 is applied to Cr plating, it is desirable to use the above-described fluoride bath as a plating solution. However, when using such a fluorine-containing plating solution, particularly as a corrosion-resistant metal, Nb or Ta It is desirable to select the one having as a main component. In this embodiment, the net-like corrosion resistant base material 230 is made of, for example, a Nb net material, and as shown in FIG. 5, lead dioxide is formed on the linear portions forming the net 211p. Consist of A conductive active material layer 231 is supported. Such a conductive active material layer 231 can be formed by, for example, electrodeposition from a lead nitrate bath or a lead monoxide bath on the net-like corrosion resistant substrate 230. Note that in order to improve the adhesion of the conductive active material layer 231, a Pt group metal such as Pt, Ir, or Ru, or an oxide thereof. Consist of An underlayer may be formed.
[0019]
The conductive active material layer 231 is supported by the net-like corrosion-resistant base material 230 as shown in FIG. 6, to the extent that all or a part of the plurality of formed nets 211p maintain a penetrating state, in other words, electrodeposition or the like. The conductive active material layer 231 that grows by this does not block all of the mesh 211p and leaves the through-holes 231a that allow the liquid flow. The conductive active material layer 231 is likely to grow in the in-plane direction of the mesh, but the closed area ratio by the conductive active material layer 231 of each mesh is preferably about 1% to 50%, for example. Moreover, the opening area ratio of the electrode segment 211 (or 250) which consists of the net-like corrosion-resistant base material 230 and the electroconductive active material layer 231 supported thereon is 0.03 to 0.5, preferably 0.1 to 0. .35 should be adjusted. On the other hand, for example, in the case of static plating, when there is no particular need to consider the liquid flow for the purpose of suppressing the generation of negative pressure, the closed area ratio due to the conductive active material layer 231 of each mesh or the electrode segment 211 ( Alternatively, the opening area ratio of 250) may be further smaller than the lower limit value of the numerical range.
[0020]
In this embodiment, as shown in FIG. 6, the net-like corrosion-resistant base material 231 is a direction in which a corrosion-resistant metal plate in which a plurality of cuts penetrating in the plate thickness direction are formed in a staggered pattern on the entire surface intersects the formation direction of the cuts. In this method, a rhombus-shaped mesh is formed by opening the slit in the deformation direction. This is a so-called expanded metal, and has an advantage that it can be manufactured at a relatively low cost by cutting and stretching a plate-like material. Also lead dioxide Consist of In order to carry the slightly brittle conductive active material layer 231, there are the following specific advantages. That is, in the case of a normal net produced by knitting wire rods, the vertical and horizontal wire rods are essentially non-bonded at the crossing position, and they slide with each other although they are traced due to expansion and contraction when exposed to temperature changes. To do. When such sliding is repeated, cracks or the like are likely to occur in the conductive active material layer carried at the crossing position of the wire, and as a result, the conductive active material layer 231 may be easily peeled off or dropped off. . However, in the expanded metal as described above, all of the linear portions forming the mesh are inseparably coupled together, so that the above-described problems are unlikely to occur.
[0021]
When the diamond-shaped mesh interval D is defined as an average value (≡ (T + S) / 2) of the long diagonal dimension T and the short diagonal dimension S, the D is 1.5 to 50 mm. It should be adjusted. If D is less than 1.5 mm, the liquid circulation effect is insufficient. On the other hand, if it exceeds 50 mm, it is difficult to ensure a sufficient discharge surface area, and the consumption of the conductive active material layer is accelerated, and the life may be easily exhausted. D is more preferably adjusted to 2 to 24 mm. On the other hand, the cross-sectional diameter of the linear part forming the mesh (the circular-equivalent diameter of the axial cross section at the approximate center position in the longitudinal direction of the linear part is defined as the cross-sectional diameter) is adjusted to 0.3 to 3 mm. It is good to be. If the cross-sectional diameter is less than 0.3 mm, it is difficult to ensure the strength as a reticulated corrosion-resistant substrate. If the cross-sectional diameter exceeds 3 mm, the mesh interval D must be considerably increased in order to sufficiently achieve the liquid circulation effect. Density tends to be excessive.
[0022]
Next, as shown in FIG. 1, the electrode base 201 is formed with a liquid circulation part 235 from the front side to which the electrode segment 211 is attached to the back side. Here, the electrode substrate 201 is formed in a frame shape, and only the surface layer portion is made of Nb or Ta. Consist of It is made of corrosion resistant metal.
[0023]
Specifically, the electrode base 202 has a substantially U-shape in which the upper ends of the vertical frames 202a and 202a disposed substantially parallel to each other in the vertical direction on both sides in the width direction of the electrode 201 are connected by the horizontal frame 202b. It has a main body 202m. The vertical frames 202a and 202a are respectively attached to both ends of a horizontally long beam-shaped electrode segment support body 204 arranged at a predetermined interval in the vertical direction. A gap formed between the electrode segment supports 204 serves as a liquid circulation part 235.
[0024]
On the other hand, the lower end side of the vertically long suspension support portions 202c and 202c is coupled to the middle portion in the longitudinal direction of the horizontal frame 202b, while the lateral power feeding portion 203 is coupled to the upper end portions of the suspension support portions 202c and 202c. A power receiving terminal portion 203a is formed at one end portion thereof. Further, hooks 202d and 202d for suspending the electrode 202 on an electrode support beam or the like (not shown) are provided on the back side of the suspension support portions 202c and 202c.
[0025]
The main body portion 202m, the electrode segment support body 204, the suspension support portions 202c and 202c, and the power feeding portion 203 (excluding the terminal portion 203a) of the electrode base body 202 are all configured as the above-described corrosion-resistant metal as a surface layer portion. It has a structure in which the surface of a core material made of a steel material such as carbon steel is covered with a corrosion-resistant metal lining (hereinafter also simply referred to as a lining). Taking the electrode segment support 204 as an example, as shown in FIG. 5, a corrosion-resistant metal (any of Ti, Nb and Ta) Consist of Things: For example, the periphery of the cores 204a and 204b is covered with a lining 226 made of a thin plate of Nb), and the joint portion of the lining 226 is sealed and sealed with a welding portion (not shown).
[0026]
Here, in order to attach the electrode segments 250 and 211, a horizontally long base-side mounting plate (also made of a corrosion-resistant metal) 205 as a base-side mounting support portion is formed of the core members 204 a and 204 b divided in the thickness direction. They are sandwiched between them, and the bolts 222 are screwed into the second divided core member 204a through the base material side mounting plate 205 from the first divided core member 204b side, thereby integrally connecting them. A head portion 222a of the bolt 222 is accommodated in a counterbore portion 204c formed on the first divided core member 204b, and the outer side is wrapped with a lining 226 in the circumferential direction. It is welded and sealed on both sides of the end. As a result, the outer surfaces of the core members 204a and 204b are covered with the corrosion-resistant metal lining 226, and the lining 226 is connected to the substrate side at the joint between the core members 204a and 204b and the substrate-side mounting support portion (substrate-side mounting plate) 205. A structure that covers the outer surface of the base end portion of the attachment support portion 205 is realized.
[0027]
The electrode segments 211 and 250 have at least a surface layer portion of Nb or Ta with respect to the electrode base body 202. Consist of The coupling member 270 made of a corrosion-resistant metal is detachably attached. In this embodiment, a horizontally long corrosion-resistant metal plate material is bent so as to have an L-shaped cross section at an intermediate position in the width direction, and one side thereof is fixed in the width direction on the back side of the segments 211 and 250 to thereby attach the segment side mounting support portion 236. Forming. Then, the segment side mounting portion 236 is overlaid on the base body side mounting plate (base body side mounting support portion) 205, and a nut 224 (all made of a corrosion-resistant metal) is screwed onto the bolt 223 passing therethrough. Conclude. That is, these bolts 223 and nuts 224 constitute a coupling member 270. Note that the insertion hole 205h of the bolt 223 (that is, the coupling position of the coupling member 270) of the base-side mounting plate is not covered with the corrosion-resistant metal lining 226. Reference numerals 225 and 225 are washers made of corrosion-resistant metal.
[0028]
As shown in FIG. 2, the electrode 201 conveys a metal strip (for example, a steel plate strip) SS, which is an object to be plated, in the longitudinal direction in a plating bath, and faces the main discharge surface 240 to one side of the metal strip SS. It is used as a plating electrode for plating this. At this time, a feeding power path is formed from the electrode base 206 to the electrode segments 211 and 250 via the base side mounting support part 205, the coupling part 270 and the segment side mounting support part 236. As shown in FIG. 3, a plurality of electrode segments 250 are arranged in the feeding direction of the metal strip SS, and a plurality of electrode segments 211 are arranged in the feeding direction and the width direction of the metal strip SS, respectively.
[0029]
Further, the abutting edge (reference numeral 250i or 211s) of the electrode segment 250 and the electrode segment 211 generated in the feeding direction of the metal strip SS is formed to be inclined with respect to the feeding direction. The butt edge as described above is a portion where the plating current density tends to be slightly non-uniform, but by tilting the plating current density with respect to the feeding direction of the metal strip SS, the non-uniform portion of the plating current density in the strip width direction. The problem that the positions are always the same is solved, which is advantageous for uniform plating.
[0030]
When exchanging electrode segments, if the shape and size differ depending on the position of the exchanged segment on the electrode, it is uneconomical because it is necessary to prepare many types of spare electrode segments. In addition, when a failure occurs in a segment having a shape that does not have a reserve, there is a problem that the repair cannot be performed immediately. Therefore, it can be said that it is advantageous that all electrode segments have the same shape and size. When forming the inclined butted edge as described above, it is desirable that at least the electrode segment 211 is formed in a parallelogram shape having substantially the same size and shape as shown in FIG. In this case, the first pair of sides 211p and 211p are arranged along the width direction of the metal strip SS, and the second pair of sides 211s and 211s are arranged so as to form a butt edge inclined with respect to the feeding direction of the metal strip SS. Will be.
[0031]
On the other hand, the electrode segment 250 may be formed on a parallelogram similar to the electrode segment 211, but in order to align the edges of the sub-discharge surface 250 on both sides in the electrode width direction, it is shown in FIG. As described above, the following configuration is desirable. That is, each electrode segment 250 has substantially the same size and the same shape, the first pair of sides 250p and 250p are substantially parallel to each other, and one of the second opposite sides is orthogonal to the first pair of sides 250p and 250p. The trapezoidal shape is an edge 250v, and the other is an oblique edge 250i that obliquely intersects the first pair of sides 250p and 250p. And it arrange | positions so that the oblique edge 250i may form the butt | matching edge part inclined between the 2nd opposite sides 211s of the electrode segment 211. FIG. By doing so, the electrode discharge surface which is square as a whole can be reasonably filled with the electrode segments 250 and 211 even though the butt edge is inclined. In addition, as shown in FIG. 4, the abutting edge part of the electrode segment 211 and the electrode segment 250 can also be formed in a staggered manner in the width direction of the metal strip SS. Here, each segment 250, 211 is formed in a rectangular shape.
[0032]
According to the electrode 201, lead dioxide is formed on the linear portions forming the mesh of the mesh-like corrosion-resistant substrate 230 of the electrode segments 211 and 250. Consist of Since the conductive active material layer 231 is carried, the carrying area per unit weight of the conductive active material 231 can be increased. As a result, the adhesion force of the conductive active material 231 to the base material is increased, and the conductive active material is less likely to be peeled off or dropped off. In addition, since the amount of the conductive active material 231 supported on the substrate surface can be made relatively large, the electrode life can be extended. On the other hand, as shown by the dashed arrows in FIG. 5, the discharge of the electrode segment 211 (250) is performed via the mesh 211p (231a) penetrating the mesh-like corrosion-resistant substrate 230 and the liquid circulation part 235 on the electrode substrate side. The liquid is allowed to flow between the surface side and the back surface side of the electrode base 206. As a result, in FIG. 2, even if the steel strip SS moves at a high speed in a state facing the discharge surface and a liquid flow is generated, a negative pressure is generated between the steel strip SS and the electrode 206 due to the flow of the liquid. Hateful. As a result, the steel strip SS and the electrode 206 are attracted / approached due to the generation of negative pressure, thereby effectively preventing a problem such as a short circuit. In addition, when a problem such as wear or damage occurs in the electrode segments 211 and 250, it is sufficient to replace only the electrode segment in which the damage or the like has occurred, and the repair can be easily performed.
[0033]
FIG. 7 shows a modification of the electrode segment (the same reference numerals are assigned to the same parts as in FIG. 5 and detailed description is omitted). In the electrode segment 260, the back plate 240 made of the corrosion-resistant metal is integrated with the back surface of the net-like corrosion-resistant base material 230. Thereby, the rigidity of the electrode segments 211 and 250 can be increased. In this embodiment, the net-like corrosion resistant base material 230 is fixed to the back plate 240 at a plurality of locations by spot welding. Moreover, the segment side attachment support part 236 is couple | bonded with the back surface side of the backplate 240 by spot welding. The conductive active material layer 231 can be attached so as to straddle the surface side of the back plate 240 in addition to the linear portion of the net-like corrosion-resistant base material 230 in order to increase the amount of the active material layer 231 supported by the base material 230. .
[0034]
As shown in FIGS. 8 and 9, the back plate 240 can be formed with a through-hole penetrating the back plate 240 in the thickness direction in order to ensure the above-described liquid flow. FIG. 8 shows an example in which square through holes 240h are arranged and formed in a matrix. On the other hand, FIG. 9 is an example in which a round hole-shaped through hole 240 h is formed in a shape corresponding to the mesh of the mesh-like corrosion-resistant substrate 230.
[0035]
In addition, when the suction of the steel strip SS is not particularly problematic (for example, when the conveyance speed of the steel strip SS is low), it is not particularly necessary to ensure the above-described liquid flow, and the back plate 240 has a through hole. It can also be configured as a plate material that does not. On the other hand, when the back plate 240 is formed of a plate material that does not have a through-hole and it is desired to ensure liquid flow, as shown in FIG. 10, the electrode segment 211 is within a range that does not cause defects such as plating unevenness. , 250 may be attached so that a predetermined amount of gap G is formed between adjacent ones, and the liquid may be circulated through the gap G. The gap G does not necessarily need to be formed between all adjacent edges of the electrode segments 211 and 250. For example, as shown in FIG. 10, the gap G intersects with the conveying direction of the steel strip SS, which has little influence on uneven plating. It can also be formed only between the facing edges.
[0036]
The reference invention will be described below.
In order to uniformly apply continuous plating to the entire surface of the steel strip, the discharge surface should be set slightly larger than the width of the steel strip so that the plated surface of the steel strip is completely included in the discharge surface of the electrode. Always. However, the discharge surface forming portion (hereinafter referred to as the “outside plate region”) located outside the through plate region of the steel plate strip basically does not contribute to the progress of plating, so the potential drops below the discharge surface and becomes a cathode. There is a drawback that the discharge surface made of the conductive active material layer tends to be consumed in the area outside the plate. For example, if the workpiece is replaced with a wide steel strip, both edges in the width direction of the new workpiece may be applied to the outside area of the previous workpiece, but the wear in the outside area of the plate progresses. If too much, it may cause defects such as defective plating. In addition, as a problem that occurs when the entire electrode plate is integrally formed, even if the consumption of the discharge surface that contributes to the plating does not progress so much, The exchange is forced to be extremely uneconomical.
[0037]
In order to solve the above problem, the following electrode configuration is effective. That is, the electrode
An electrode substrate;
Any of Ti, Nb and Ta Consist of Lead dioxide on the surface of the corrosion-resistant substrate Consist of A main electrode plate having a structure covered with a conductive active material layer, attached to an electrode base so that the conductive active material layer is a front surface, and forming a main discharge surface by the conductive active material layer;
It is formed separately from the main electrode plate and is one of Ti, Nb and Ta Consist of Pt group metal on the surface of the corrosion resistant base plate Consist of It has a structure covered with a noble metal-based coating layer, and is attached to the electrode substrate so that the noble metal-based coating layer faces the electrode substrate on both sides in the width direction of the sub-discharge surface. A sub-electrode plate forming
It is provided with.
[0038]
For example, when the metal strip as the object to be plated is transported in the longitudinal direction and the main discharge surface is opposed to one side of the metal strip and used as a plating electrode for plating, the above-described cathode is used in the region outside the plate. It is exposed to an environment where wear is likely to progress due to conversion. Therefore, the discharge surface portion adjacent to both sides in the width direction of the main discharge surface, which is the outer region of the through plate, is made of Pt group metal. Consist of By forming it as the above-mentioned sub-discharge surface made of a noble metal-based coating layer, it becomes possible to prevent or suppress consumption on the sub-discharge surface very effectively.
[0039]
An example of the electrode as described above can be configured as having the same form as in FIG. 1, but in this case, the electrode segments can be arranged as shown in FIG. 11, for example. In this example, the same electrode segment as that shown in FIG. 1 or the like is adopted as the main discharge segment (main electrode plate) 211 as the electrode segment corresponding to the sheet passing region of the steel plate strip SS. The main discharge segment 211 forms the main discharge surface 340 by the lead-based coating layer 231 described above. On the other hand, what is located outside the through plate is replaced with the electrode segment 211 of FIG. 1 and the sub discharge segment (sub electrode plate) 210 having the following configuration is adopted.
[0040]
That is, the sub electrode segment 210 is one of Ti, Nb and Ta as shown in FIG. Consist of The surface of the corrosion resistant base plate 220 is made of a Pt group metal (for example, Pt). Consist of It has a structure covered with a noble metal-based coating layer 221 (the same reference numerals are assigned to the same parts as in FIG. 5 and detailed description is omitted). Then, the noble metal-based coating layer 221 is attached to the electrode base so that the noble metal-based coating layer 221 faces the electrode base 202 on both sides in the width direction of the main discharge surface 340 (FIG. 11). As shown in FIG. 11, the sub-electrode segment 210 forms a sub-discharge surface 350 by the noble metal-based coating layer 221. The thickness of the noble metal coating layer 221 is, for example, about 1 to 400 μm (about 4.5 μm in this embodiment). The noble metal-based coating layer 221 can be formed, for example, by plating a corrosion-resistant base plate 230 with a Pt group metal such as Pt, Ir, or Ru, and a clad plate in which these metal thin plates are pressure-bonded (or welded) to the corrosion-resistant base plate. Can also be used (in this example a Pt foil cladding).
[0041]
By forming the sub-discharge surface 350 as described above with a noble metal-based coating layer, wear on the sub-discharge surface 350 can be effectively prevented or suppressed. Further, even if a problem such as wear or damage occurs on the sub-discharge surface 350, the sub-electrode segment 210 that forms the sub-discharge surface 350 is formed separately from the main electrode segment 211 that forms the main discharge surface 340. Therefore, it is sufficient to replace only the sub-electrode segment 210, and the repair can be easily performed.
[Brief description of the drawings]
FIG. 1 is a front view, a plan view, a bottom view, and a side view showing an embodiment of an electrode of the present invention.
FIG. 2 is a schematic diagram showing an example of how the electrode of FIG. 1 is used.
FIG. 3 is a front view showing an extracted arrangement form of electrode segments in the electrode of FIG. 1;
FIG. 4 is a front view showing a modification of the shape and arrangement of electrode segments.
5 is a side cross-sectional view showing an example of a structure for attaching the electrode segment of FIG. 1 to an electrode substrate.
FIG. 6 is an enlarged front view of a net-like corrosion resistant base material.
FIG. 7 is a side sectional view showing an example of an electrode segment having a back plate together with its mounting structure.
FIG. 8 is a schematic view showing an example of a form of forming a through hole in the back plate.
FIG. 9 is a schematic diagram showing a modified example of the same.
FIG. 10 is a front view showing an example in which a gap is formed between adjacent electrode segments.
FIG. 11 is a front view showing an example of an arrangement form of electrode segments in the reference invention.
12 is a side cross-sectional view showing an example of an attachment structure of the electrode segment of FIG. 11 to an electrode substrate.
[Explanation of symbols]
201 electrodes
202 Electrode substrate
205 Base material side mounting plate (Base material side mounting support)
211,250 Electrode segment
211p mesh
230 Reticulated corrosion resistant substrate
231 Conductive active material layer
231a Through hole
235 Liquid Distribution Department
236 Segment side mounting support
240 Main discharge surface
250 Sub-discharge surface
270 coupling member

Claims

An electrode substrate;
It is attached to the front side of the electrode base with the side facing the member to be processed as the front side, and is integrated with a reticulated corrosion-resistant base material composed of a corrosion-resistant metal made of any of Ti, Nb and Ta, and the back side thereof. And a back plate made of a corrosion-resistant metal made of any one of Ti, Nb, and Ta, and a conductive active material layer made of lead dioxide supported on a linear portion that forms a mesh of the network-like corrosion-resistant substrate. A plurality of electrode segments that form a discharge surface with one side facing the object to be plated, in a state attached to the electrode substrate,
An electrode comprising:

The mesh-like corrosion-resistant substrate of the electrode segment is formed by deforming a corrosion-resistant metal plate having a plurality of cuts penetrating in the thickness direction in a zigzag pattern on the entire surface in a direction intersecting with the cut formation direction. 2. The electrode according to claim 1, wherein a diamond-shaped mesh is formed by opening in the deformation direction .

The distance between the rhomboid meshes is defined as an average value of the long diagonal dimension T and the short diagonal dimension S, and in the case, the D is adjusted to 1.5 to 50 mm. electrode.

The electrode according to claim 2 or 3, wherein a cross-sectional diameter of the linear portion forming the mesh is adjusted to 0.3 to 3 mm .

The electrode base is formed with a liquid circulation part extending from the front side to the back side, with the side facing the member to be processed being the front side.
The back plate has a through-hole in the thickness direction,
The discharge surface side of the electrode segment and the back surface of the electrode substrate through the mesh of the mesh corrosion-resistant substrate of the electrode segment, the through hole of the back plate, and the liquid circulation part formed in the electrode substrate The electrode according to any one of claims 1 to 4, wherein the electrode has a structure that allows a liquid to flow between the sides .

The electrode base is formed with a liquid circulation part extending from the front side to the back side, with the side facing the member to be processed being the front side.
A plurality of the electrode segments are attached to the electrode base so that a predetermined amount of gaps are formed between those adjacent to each other,
The liquid is allowed to flow between the discharge surface side of the electrode segment and the back surface side of the electrode substrate via the gap between the electrode segments and the liquid circulation part formed on the electrode substrate. The electrode according to claim 1, which has a structure .

A segment-side mounting support portion formed on the back side of each electrode segment, a base-side mounting support portion formed on the electrode base side, and the segment-side mounting support portion and the base-side mounting support portion are detachably coupled. The power supply path from the said electrode base to each electrode segment through the said base | substrate side attachment support part, the said connection part, and the said segment side attachment support part is formed. An electrode according to the above.

The electrode substrate is
A steel core,
The base end portion is bonded to the core, and the base-side mounting support portion made of a corrosion-resistant metal made of one or more of Ti, Nb and Ta,
Ti, Nb, and Ta covering the outer surface of the core material and covering the outer surface of the base side mounting support portion at the joint portion between the core material and the base side mounting support portion. The electrode according to claim 7, comprising any one of corrosion-resistant metal linings .

An electrode substrate;
The surface facing the member to be treated is the front side, and is attached to the front side of the electrode base, and covers the corrosion-resistant base made of a corrosion-resistant metal made of any one of Ti, Nb, and Ta, and the surface of the corrosion-resistant base An electrode segment having a conductive active material layer made of lead dioxide ;
A segment side mounting support portion formed on the back side of each electrode segment;
A base-side mounting support portion formed on the electrode base side;
A coupling member that removably couples the segment side mounting support portion and the base body side mounting support portion,
A feeding path is formed from the electrode base to each electrode segment through the base-side mounting support, the coupling member, and the segment-side mounting support, and the electrode base is
A steel core,
The base side mounting support portion made of a corrosion-resistant metal made of any one of Ti, Nb, and Ta is disposed so as to protrude from the outer surface of the core material in a form in which a base end portion is coupled to the core material,
Ti, Nb, and Ta covering the outer surface of the core material and covering the outer surface of the base side mounting support portion at the joint portion between the core material and the base side mounting support portion. An electrode comprising a corrosion-resistant metal lining made of any of the above .

The electrode according to any one of claims 1 to 9, which is disposed so as to face a plate surface of a member to be processed conveyed in a longitudinal direction, and is used for continuously performing electrochemical treatment on the member to be processed .