JPS6058312B2 - Lead dioxide coated electrode for electrolysis - Google Patents

Description

【発明の詳細な説明】 本発明は電解用二酸化鉛被覆電極に関し、特にその目
的とするところは、機械的強度および寸法安定性にすぐ
れ、基板として使用するチタンの耐食性の乏しい条件に
おいて使用可能な電解用二酸化鉛被覆電極を提供するこ
とにある。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lead dioxide coated electrode for electrolysis, and a particular object thereof is to provide an electrode coated with lead dioxide for electrolysis, which has excellent mechanical strength and dimensional stability, and which can be used in conditions where titanium used as a substrate has poor corrosion resistance. An object of the present invention is to provide a lead dioxide coated electrode for electrolysis.

工業電解に用いられる電極としては、その性能、耐久
性と共に電極形態および機械的強度、加工性などが十分
満足できるものでなくてはならない。Electrodes used in industrial electrolysis must be sufficiently satisfactory in performance, durability, electrode form, mechanical strength, workability, etc.

近年、チタンなどの基板上の白金族金属化合物を被覆し
た金属電極が出現し、そのすぐれた性能と同時に強度、
寸法安定性のよいという利点の故に、食塩電解工業その
他に著しい進歩をもたらした。 一方、従来から認めら
れてきた二酸化鉛電極は白金につぐ高酸素過電圧をもち
、かつ特異な電極触媒能を有するすぐれた安価な電極で
ある。In recent years, metal electrodes coated with platinum group metal compounds on substrates such as titanium have appeared, and their excellent performance as well as strength and
Because of its advantage of good dimensional stability, it has provided significant advances in the brine electrolysis industry and elsewhere. On the other hand, the lead dioxide electrode, which has been recognized in the past, is an excellent and inexpensive electrode that has a high oxygen overvoltage second only to platinum and has a unique electrocatalytic ability.

しかし、本格的な実用化に至らないのは、この電極の機
械的強さと加工性の不足、寸法安定性の欠除などが原因
となつている。 板状の二酸化鉛電極の製法としては、
従来、硝酸鉛浴などから凹面陽極電着し、抜き取る方法
によつているが、内部歪が存在するため脆弱で大型化し
にくく、形状も制限される。However, the reason why it has not been put into full-scale practical use is due to the lack of mechanical strength and workability of this electrode, as well as the lack of dimensional stability. The manufacturing method for plate-shaped lead dioxide electrodes is as follows:
Conventionally, the method has been to electrodeposit a concave anodic electrode from a lead nitrate bath or the like and then extract it, but due to the presence of internal strain, it is brittle and difficult to increase in size, and its shape is also limited.

そのため、黒鉛板、チタン板に直接二酸化鉛を電着する
試みがなされたが、クラックの発生、密着不良などによ
り剥離、脱落をおこし成功していない。最近ではチタン
金網を芯材として電着する方法がある。しかし、密着性
は向上するが網目を埋めて平滑に厚付けし、平板状にす
ることは困難で、多くは凹凸状となり寸法安定性にも欠
け、また重量も増加するので強度的にも大型化は無理で
ある。 これらの欠点を改良すべくチタン板上にチタン
のエキスパンドメタル（特公昭５８−３０９５７）やチ
タン製パンチングメタル、チタン製金網（特公昭５８−
３１３９６）などを溶接し、その周縁部をチタン製の押
え板で補強し、中間層を介して二酸化鉛を電着する方法
が試みられた。For this reason, attempts have been made to electrodeposit lead dioxide directly onto graphite plates and titanium plates, but these attempts have not been successful due to cracks, poor adhesion, etc., resulting in peeling and falling off. Recently, there is a method of electrodepositing titanium wire mesh as a core material. However, although it improves adhesion, it is difficult to fill in the mesh and make it thick and smooth, making it into a flat plate.In many cases, it becomes uneven and lacks dimensional stability.It also increases weight, making it large in terms of strength. It is impossible to change it. In order to improve these defects, titanium expanded metal (Special Publication No. 58-30957), titanium punched metal, and titanium wire mesh (Special Publication No. 58-30957) were developed on titanium plates.
31396), the peripheral edge of which was reinforced with a titanium holding plate, and lead dioxide was electrodeposited through the intermediate layer.

この方法により機械的強度、寸法安定性は著しく向上し
た。しかし、押え板や基板のエッヂ部分のチタンが露出
しているため、チタンの耐食性のない条件、たとえばク
ロムメッキのケイフッ化浴のような系では押え板や基板
が腐食され二酸化鉛の性能を十分発揮できない。本発明
者らは、以上のような欠点を少なくし、機械的強度、寸
法安定性にすぐれ、かつ基板のチタンの耐食性の乏しい
条件においても使用可能な電解用二酸化鉛被覆電極を得
るべく種々検討を加えた結果、平板状のチタン基板上に
あらかじめ第１のチタン製エキスパンド板を密着させ、
スポット溶接、シーム溶接などにより固定し、さらにそ
の上に第２のチタンエキスパンド板を基板にスポット溶
接して補強したのちその上に酸化防止用の電導性中間層
を介して全面に二酸化鉛を電着することにより板状で密
着性にすぐれ、寸法安定性が良く、しかもチタン基板の
耐食性のない条件で使用てきる電解用二酸化鉛被覆電極
を得ることに成功したものである。This method significantly improved mechanical strength and dimensional stability. However, since the titanium on the edges of the holding plate and the substrate is exposed, under conditions where titanium does not have corrosion resistance, such as systems such as silica fluoride baths for chrome plating, the holding plate and the substrate will corrode and the performance of lead dioxide will not be sufficient. I can't perform. The present inventors have conducted various studies in order to reduce the above-mentioned drawbacks, to obtain a lead dioxide-coated electrode for electrolysis that has excellent mechanical strength and dimensional stability, and can be used even under conditions where the corrosion resistance of titanium as a substrate is poor. As a result, the first expanded titanium plate was brought into close contact with the flat titanium substrate in advance,
It is fixed by spot welding, seam welding, etc., and then a second expanded titanium plate is spot welded to the substrate for reinforcement, and then lead dioxide is electrically applied over the entire surface through a conductive intermediate layer for oxidation prevention. By applying this method, we succeeded in obtaining a lead dioxide-coated electrode for electrolysis that is plate-shaped, has excellent adhesion, has good dimensional stability, and can be used under conditions where titanium substrates do not have corrosion resistance.

すなわち、本発明の電極はチタン基板と前記チタン基板
表面上に溶接された菱形の対角線長辺寸法およ短辺寸法
がそれぞれ０．５〜５Ｔｆ！：！ｎ（５０．５〜２．５
ｍの範囲から成り、かつストランド幅および板厚がそれ
ぞれ０．１０１悶と０．０５〜０．６順の範囲から成る
第１のチタン製のエキスパンド板と、前記エキスパンド
板上に溶接された菱形の対角線長辺寸法と短辺寸法がそ
れぞれ２０〜６０ＴＷｉと１０〜３−の範囲から成り、
かつストランド幅および板厚がそれぞれ１．０〜，３．
０ｗｒ１ｎと１．０〜２．５Ｔｒｒ！ｎの範囲から成る
第２のチタン製エキスパンド板と、前記第１、第２のエ
キスパンド板上に被覆された白金族金属、これらの合金
および酸化物の中から選ばれた少なくとも１種の中間層
と、前記中間層上に電着された二酸化鉛とから成ること
を特徴とする電解用二酸化鉛被覆電極てある。That is, in the electrode of the present invention, the diagonal long side and short side of the titanium substrate and the rhombus welded on the surface of the titanium substrate are respectively 0.5 to 5 Tf! :! n(50.5~2.5
a first titanium expanded plate having a strand width and a plate thickness of 0.101 and 0.05 to 0.6, respectively, and a diamond shape welded on the expanded plate; The diagonal long side dimension and short side dimension of are in the range of 20 to 60TWi and 10 to 3-, respectively,
And the strand width and plate thickness are respectively 1.0 to 3.
0wr1n and 1.0~2.5Trr! a second expanded titanium plate consisting of a range of n; and at least one intermediate layer selected from platinum group metals, alloys and oxides thereof, coated on the first and second expanded plates. and lead dioxide electrodeposited on the intermediate layer.

本発明の電極は第１図に示すようにチタン基板１、第１
のエキスパンド板２、第２のエキスパンド板３、中間層
４、二酸化鉛層５から成つている。As shown in FIG. 1, the electrode of the present invention includes a titanium substrate 1, a first
It consists of an expanded plate 2, a second expanded plate 3, an intermediate layer 4, and a lead dioxide layer 5.

すなわちチタン基板１をサンドブラスト、エッチングな
どにより表面を粗面化しておき、これに第１のチタン製
エキスパンド板２を十分密着させ、適当な間隔をもつて
溶接する。さらにその上にあらかじめエッチングなどに
より表面を粗面化しておいて第２のチタン製エキスパン
ド板３を適当な間隔をもつて基板に溶接する。さらにト
リクレン洗浄、およびふつ酸処理したのち、中間層４を
介して二酸化鉛層５を陽極電着により形成させる。本発
明に使用するチタン基板１の厚さ大きさは目的に応じて
任意である。That is, the surface of the titanium substrate 1 is roughened by sandblasting, etching, etc., and the first expanded titanium plate 2 is brought into close contact with the titanium substrate 1 and welded at an appropriate interval. Furthermore, the surface is roughened by etching or the like beforehand, and a second expanded titanium plate 3 is welded to the substrate at an appropriate interval. After further cleaning with trichlorethylene and treatment with hydrofluoric acid, a lead dioxide layer 5 is formed via the intermediate layer 4 by anodic electrodeposition. The thickness and size of the titanium substrate 1 used in the present invention are arbitrary depending on the purpose.

本発明の第１のエキスパンド板は、あらかじめチタン基
板に密着するように平坦に矯正しておき部分溶接、たと
えば点あるいは線状の溶接が施される。The first expanded plate of the present invention is flattened in advance so as to be in close contact with the titanium substrate, and then partially welded, such as point or line welding, to the titanium substrate.

溶接個所の間隔などは材料の大きさ、密着の度合などに
より粗または密にするが、ピッチは１０〜２００ＷｒＩ
！ｔくらいである。第１のエキスパンド板の好適なサイ
ズを第２図によつて説明する。菱形の対角線長辺寸法（
ＬＷＤ）および短辺寸法（ＳＷＤ）がそれぞれ０．５〜
５，０．５〜２．５Ｔｆｎの範囲が良く、これより小さ
いと二酸化鉛がエキスパンド板とチタン基板との間隔を
うめることができず、密着性が低下する。また、ストラ
ンド幅（Ｗ）、および板厚（Ｔ）は、それぞれ０．１〜
１順，０．０５〜０．６ｗｒ！ＲＬの範囲が良い。スト
ランド幅（Ｗ）が０．１順より小さいとエキスパンド板
が強度的に弱くなり、１Ｔｆｒｍより大きいと調製後の
電極に凹凸が生じるおそれがある。板厚（Ｔ）について
も同様で０．０５〜０．６ｗｎの範囲が選ばれる。また
エキスパンド板の代わりに金網を使用することもでき、
この場合２４〜２５０メッシュの網を用いる。本発明の
第２のエキスパンド板は第１のエキスパンド板の上から
チタン基板に部分溶接により取り付けられ、チタン基板
と第１のエキスパンド板を確実に固定させる。The spacing between welding points can be coarse or dense depending on the size of the material, degree of adhesion, etc., but the pitch should be 10 to 200 WrI.
! It is about t. A suitable size of the first expandable plate will be explained with reference to FIG. Diagonal long side dimension of rhombus (
LWD) and short side dimension (SWD) are each 0.5~
A range of 5,0.5 to 2.5 Tfn is preferable; if it is smaller than this, lead dioxide will not be able to fill the space between the expanded plate and the titanium substrate, resulting in poor adhesion. In addition, the strand width (W) and plate thickness (T) are each 0.1 to
1st order, 0.05~0.6wr! Good RL range. If the strand width (W) is smaller than 0.1, the strength of the expanded plate becomes weak, and if it is larger than 1 Tfrm, there is a risk that the prepared electrode will have irregularities. Similarly, the plate thickness (T) is selected from a range of 0.05 to 0.6wn. You can also use wire mesh instead of the expanded board.
In this case, a net of 24 to 250 mesh is used. The second expanded plate of the present invention is attached to the titanium substrate from above the first expanded plate by partial welding, thereby reliably fixing the titanium substrate and the first expanded plate.

この結果二酸化鉛層の強度が増し剥離が防止させる。第
２のエキスパンド板の好適なサイズを第２図によつて説
明する。菱形の対角線長辺寸法（ＬＷＤ）および短辺寸
法（ＳＷＤ）がそれぞれ２０〜６０順と１０〜３０醜の
範囲が良く、これにより小さいと第１のエキスパンド板
による効果がそこなわれ、これにより大きいと第１のエ
キスパンド板とチタン基板との固定が不十分となる。ま
たストランド幅（Ｗ）、および板厚（Ｔ）はそれぞれ１
．０〜３．０Ｗ！ｌと１０〜２．５ＴｆｒＩｎの範囲が
良い。ストランド幅（Ｗ）が１．０より小さいと、第１
のエキスパンド板の板厚が小さすぎるため溶接強度が不
足している部分を第２のエキスパンド板によつて補強す
る効果が不十分となり、３．０ｍより大きいと電極表面
の凹凸が激しいなり、かつ該エキスパンド板への密着性
が劣化する。板厚（Ｔ）についても同様で１．０〜２．
５ｗ！ｎの範囲が選ばれる。中間層はチタン基板および
第１、第２のエキスパンド板の表面の酸化防止のため介
在させるが、耐酸化性、電導性の白金族金属、それらの
合金またはそれらの酸化物の少なくとも１種より成り、
厚みは１ｐ程度にする。As a result, the strength of the lead dioxide layer is increased and peeling is prevented. A suitable size of the second expandable plate will be explained with reference to FIG. The diagonal long side dimension (LWD) and short side dimension (SWD) of the rhombus are preferably in the range of 20 to 60 and 10 to 30, respectively. If it is too large, the first expanded plate and the titanium substrate will not be sufficiently fixed. In addition, the strand width (W) and plate thickness (T) are each 1
．． 0~3.0W! A range of 10 to 2.5 TfrIn is preferable. If the strand width (W) is smaller than 1.0, the first
Because the thickness of the expanded plate is too small, the effect of reinforcing the part where welding strength is insufficient by the second expanded plate is insufficient. Adhesion to the expanded plate deteriorates. The same applies to the plate thickness (T), which is 1.0 to 2.
5w! A range of n is selected. The intermediate layer is interposed to prevent oxidation of the surfaces of the titanium substrate and the first and second expanded plates, and is made of at least one oxidation-resistant and conductive platinum group metal, an alloy thereof, or an oxide thereof. ,
The thickness should be about 1p.

用いる金属としてはＰｔ，Ｉｒ，Ｒｈ，Ｐｄなどで電気
めつき、あるいは可溶性の該当金属塩含有塗布液から熱
分解法によつて被覆が調製される。本発明の二酸化鉛層
は陽極電着によりチタン基板およびエキスパンド板の表
面に施された中間層上に全面被覆されるが、電着液は鉛
塩および銅塩とから成り、鉛塩としては硝酸鉛、スルフ
ァミン酸鉛、酢酸鉛などを使い、銅塩としてはおもに硝
酸銅を用いる。The metal used is Pt, Ir, Rh, Pd, etc., and the coating is prepared by electroplating or by thermal decomposition from a coating solution containing a soluble metal salt. The lead dioxide layer of the present invention is entirely coated on the intermediate layer applied to the surface of the titanium substrate and the expanded plate by anodic electrodeposition, and the electrodeposition solution consists of lead salt and copper salt, and the lead salt is nitric acid. Lead, lead sulfamate, lead acetate, etc. are used, and copper nitrate is mainly used as the copper salt.

電着液中の鉛および銅としての濃度は、それぞれ１００
〜２１０ｇ／１１４〜２０ｇ／１であり、液温度は６０
〜８０′Ｃ，．ＰＨは３．５〜４．５に保たれる。陽極
電流密度は１〜５Ａ／Ｄ７７（′で陰極としてはステン
レス鋼を用いて電解を行なう。この間液性をＰＨ３．５
〜４．５に保つために、一酸化鉛、炭酸鉛、水酸化鉛な
どを加えて調節する。これらの条件をはすれると島状電
着やこふ状電着を生じやすくなり内部歪も増大し、被覆
にクラックや電着物の剥離を起こしやすくなり好ましく
ない。二酸化鉛の被覆の厚みは、必要に応じて０．３〜
５ｗｎとすすが、これは電着時間の長短によ一リ調整さ
れる。このようにして電着は終了するが、こぶ状の電着
物やピンホールなどはできず、基板表面に応じて均一な
被覆が得られる。本発明の二酸化鉛電極は塩素酸塩、過
塩素酸塩、過汰素酸塩の電解製造用の陽極として好適で
あるほか、金属の電解精練、廃液の電解処理、電気めつ
き用の陽極として使用できる。The concentration of lead and copper in the electrodeposition solution was 100% each.
~210g/114~20g/1, and the liquid temperature is 60g/114~20g/1.
~80'C,. PH is kept between 3.5 and 4.5. Electrolysis is performed using stainless steel as the cathode at an anode current density of 1 to 5 A/D77 ('. During this time, the liquid property is adjusted to pH 3.5.
To maintain the temperature at ~4.5, adjust by adding lead monoxide, lead carbonate, lead hydroxide, etc. If these conditions are not met, island-like electrodeposition or cuff-like electrodeposition tends to occur, internal strain increases, cracks in the coating and peeling of the electrodeposited material tend to occur, which is undesirable. The thickness of the lead dioxide coating is 0.3~
The amount of soot is 5wn, but this is adjusted depending on the length of the electrodeposition time. Although the electrodeposition is completed in this way, no lump-like electrodeposit or pinholes are formed, and a uniform coating is obtained depending on the substrate surface. The lead dioxide electrode of the present invention is suitable as an anode for the electrolytic production of chlorate, perchlorate, and pertenate, as well as for electrolytic refining of metals, electrolytic treatment of waste liquid, and electroplating. Can be used.

特にクロムメッキにおけるケイフッ化浴のようにチタン
の耐食性の乏しい条件においても、基板のチタンが露出
することなく二酸化鉛で均一に被覆されているため、二
酸化鉛の性能を十分に発揮することができる。本発明の
二酸化鉛被覆電極はチタン基板に第１のエキスパンド板
を溶接し、その上に第２のエキスパンド板を溶接して補
強したのち中間層を介して二酸化鉛を全面に電着により
被覆しているため従来問題のあつた平板上への二酸化鉛
の強固な被覆が可能となつた。In particular, even under conditions where titanium has poor corrosion resistance, such as in a silica fluoride bath for chrome plating, the titanium on the substrate is not exposed and is evenly coated with lead dioxide, allowing the performance of lead dioxide to be fully demonstrated. . The lead dioxide coated electrode of the present invention is produced by welding a first expanded plate to a titanium substrate, reinforcing it by welding a second expanded plate thereon, and then covering the entire surface with lead dioxide by electrodeposition through an intermediate layer. Because of this, it has become possible to firmly coat the flat plate with lead dioxide, which was a problem in the past.

この結果、一般に金属電極並みの強度とすぐれた寸法安
定性をもつている。従つて極間距離を可及的に狭くする
ことが可能となり摺電圧が低減された。そしてチタンの
耐久性のない環境においても二酸化鉛の性能を十分発揮
し長時間にわたり安定した電解操業が可能となり、工業
的価値がきわめて大である。つぎに本発明の態様を実施
例で示すが、その主旨はこれらの例によつて何ら制約さ
れるものではない。As a result, they generally have strength comparable to metal electrodes and excellent dimensional stability. Therefore, the distance between the poles can be made as narrow as possible, and the sliding voltage can be reduced. Even in an environment where titanium is not durable, lead dioxide can fully demonstrate its performance and enable stable electrolytic operation over a long period of time, making it extremely valuable industrially. Next, embodiments of the present invention will be illustrated by examples, but the gist thereof is not limited in any way by these examples.

実施例１ 縦１２０ｗｎ１横５−、厚さ３？のチタン基板をサンド
ブラスト処理し、この上にＬＷＤちＳＷＤがそれぞれ２
．０および１．０ｍで板厚およびストランド幅がそれぞ
れ０．１２と０．１８ｍの第１のチタン製エキスパンド
板を密着させて重ねスポット溶接した。Example 1 Height 120wn1 Width 5-, Thickness 3? A titanium substrate is sandblasted, and two LWDs and two SWDs are placed on top of this.
．． First titanium expanded plates having thicknesses of 0 and 1.0 m and strand widths of 0.12 and 0.18 m, respectively, were brought into close contact and overlapped and spot welded.

この上にＬＷＤおよびＳＷＤがそれぞれ３０ｒｒ＄＆と
１６？で板厚およびストランド幅が１．６瓢で１１２圧
延した第２のエキスパンド板をスポット溶接して基板に
強固に固定し、電極基体を作製した。その電極基体をト
リクレン洗浄により脱脂を行なつたのち５％ふつ酸溶液
に浸漣して表面処理を施した。次に塩化白金３重量部、
塩化イリジウム１重量部、イソプロピルアルコール３鍾
量部から成る塗布液を塗布し、乾燥したのち５０℃で加
熱処理し、０．７μの中間層を形成させた。この電極基
体を陽極とし、ステンレス鋼板を陰極として硝酸鉛と硝
酸鋼とから成る電着液中で田時間陽極電着し、約１．５
Ｔｆｒｍ厚の二酸化鉛の被覆を得た。このときの鉛およ
び銅イオンの濃度は２００ｇ／ｅおよび６．５ｇ／ｅで
あり、陽極電流密度は２．５Ａ／Ｄｄｌ平均の液温度は
６５℃、液性はＰＨ４．揃後に保つた。二酸化鉛被覆は
全面にほぼ均一に電着され、表面は部分的こぶ状の突起
物もなくすぐれていた。比較例１ 本発明の電極の効果を知るため、縦１２−、横５０７１
７７！厚さ３Ｗｆｍのチタン板を基体とし、実施例１と
・同じ条件で前処理、中間層被覆、そして二酸化鉛被覆
を行ない、被覆表面にガムテープを接着させ、ロールで
加圧したのちテープを引きはがし、密着性を観察した。On top of this, LWD and SWD are each 30rr$&16? A second expanded plate having a plate thickness and strand width of 1.6 mm and rolled at 112 mm was spot welded to firmly fix it to the substrate, thereby producing an electrode base. The electrode substrate was degreased by trichlene cleaning, and then immersed in a 5% hydrogen chloride acid solution for surface treatment. Next, 3 parts by weight of platinum chloride,
A coating solution consisting of 1 part by weight of iridium chloride and 3 parts by weight of isopropyl alcohol was applied, dried and then heat treated at 50°C to form an intermediate layer of 0.7μ. Using this electrode substrate as an anode and a stainless steel plate as a cathode, electrodeposition was performed in an electrodeposition solution consisting of lead nitrate and steel nitrate for approximately 1.5 hours.
A lead dioxide coating of Tfrm thickness was obtained. The concentrations of lead and copper ions at this time were 200 g/e and 6.5 g/e, the anode current density was 2.5 A/Ddl, the average liquid temperature was 65°C, and the liquid pH was 4. I kept it after finishing it. The lead dioxide coating was electrodeposited almost uniformly over the entire surface, and the surface was excellent with no local bump-like protrusions. Comparative Example 1 In order to understand the effect of the electrode of the present invention, a
77! Using a titanium plate with a thickness of 3 Wfm as a base, pretreatment, intermediate layer coating, and lead dioxide coating were performed under the same conditions as in Example 1. Gum tape was adhered to the coating surface, pressure was applied with a roll, and then the tape was peeled off. , adhesion was observed.

また、実施例１と同じ方法で製作した本発明の電極につ
いても同様の試験を行なつた。結果を第１表に示した。
実施例２実施例１て製作した電極を陽極として軟鋼上に
クロムめつきを行なつた。Further, similar tests were conducted on the electrode of the present invention manufactured by the same method as in Example 1. The results are shown in Table 1.
Example 2 Using the electrode manufactured in Example 1 as an anode, chromium plating was performed on mild steel.

めつた浴組成は下記のとおりであり、電流密度５０Ａ／
Ｄｒｆｔｌ槽温度６０℃でめつきを行なつた。また比較
のため、チタン板上にエキスパンド板をスポット溶接し
、その周縁部に押え板をスポット溶接し補強したのち、
押え板を除いた部分のみ中間層を介して二酸化鉛を被覆
した電極（比較電極と略す）に関しても同じ条件でめつ
きを行なつた。めつき液組成 無水クロム酸 ２５０ｇ／′ケイふ
つ化ナトリウム １０ｇ／ｅ硫 酸
１ｇ／Ｅ６ケ月の電解中、本発
明の電極は電圧上昇もなくまた形状の変化、剥離もなく
、表面状態も良好てありニ酸化鉛の特徴を十分発揮し、
安定した性態を示した。The composition of the bath is as follows, and the current density is 50A/
Plating was carried out at a Drftl bath temperature of 60°C. For comparison, an expanded plate was spot welded onto a titanium plate, and a presser plate was spot welded around its periphery for reinforcement.
Plating was also performed under the same conditions on an electrode (abbreviated as a reference electrode) in which only the portion excluding the holding plate was coated with lead dioxide through an intermediate layer. Plating liquid composition Chromic anhydride 250g/'sodium silicate 10g/e Sulfuric acid
During electrolysis of 1 g/E for 6 months, the electrode of the present invention exhibited no voltage increase, no change in shape, no peeling, and had a good surface condition, fully demonstrating the characteristics of lead dioxide.
It showed stable behavior.

しかし比較電極は、１ケ月経過後には露出している押え
板や基板のチタンが腐食されてしまい、二酸化鉛の溶出
は微少であるのにもかかわらず、電解不能となつた。実
施例３ 実施例１で製作した電極を陽極とし、ステンレス鋼板を
陰極として、つぎに示した電解条件で過塩素酸の電解製
造を行なつた。However, after one month had passed, the exposed titanium of the holding plate and substrate of the reference electrode had corroded, and electrolysis was no longer possible, even though the elution of lead dioxide was minute. Example 3 Using the electrode produced in Example 1 as an anode and a stainless steel plate as a cathode, perchloric acid was electrolytically produced under the following electrolytic conditions.

電解条件 陽 極・・・・・・実施例１で製作した電極陰 極
・・・・・・ステンレス鋼板 （５０×１３
０Ｘ３７ｖｎ２枚）電解液・・・・・・ＮａＣｌＯ３５
ＯＯｇ／′，ＮａＦ２ｇ／ｅ極間距離・・・・・・５順
従来の二酸化鉛電極においては、１５〜３０７ｍの極間
距離が必要であつたが、本電極では５Ｔｗｔで摺電ノ圧
は０．２〜０．５Ｖ低減し、平均電流効率羽％において
所要電力は５〜１０％節約された。Electrolysis conditions Anode: Electrode produced in Example 1 Cathode: Stainless steel plate (50 x 13
0X37vn 2 sheets) Electrolyte...NaClO35
OOg/', NaF2g/e inter-electrode distance...5 order Conventional lead dioxide electrodes required an inter-electrode distance of 15 to 307 m, but with this electrode, the sliding voltage was 5 Twt. The power requirement was reduced by 0.2-0.5V, and the power required was saved by 5-10% in average current efficiency.

本電極は６ケ月以上の長期にわたり、安定した操業を続
け、この間形状の変化、剥離もなく、表面の変化も見ら
れなかつた。実施例４ 実施例１と同じ方法で製作した電極を陽極とし、ステン
レス鋼板を陰極として、下記条件で無電解メッキ廃液の
ＣＯＤ電解処理を行なつた。This electrode continued to operate stably for a long period of over 6 months, and during this period there was no change in shape, no peeling, and no change in the surface was observed. Example 4 Using an electrode manufactured in the same manner as in Example 1 as an anode and a stainless steel plate as a cathode, electroless plating waste liquid was subjected to COD electrolytic treatment under the following conditions.

電解条件陽 極・・・・・・本発明の電極 陰 極・・・・・・ステンレス鋼板 電解液 ・・・・・無電解メッキ廃液 ＣＯＤ・・・・・４８０００ｐｐｍ（スタート）極
間・・・・・・３０ｍ電流密度・・・・・・１０Ａ／Ｄ
ｄ 温 度・・・・・・６０ＡＣ 電解開始時に４８０００ｐｐｍあつたＣＯＤは２僻間電
解後約８００ｐｐｍまで低減することができた。Electrolytic conditions Anode: Electrode of the present invention Cathode: Stainless steel plate electrolyte: Electroless plating waste liquid COD: 48,000 ppm (start) electrode
Between...30m Current density...10A/D
d Temperature: 60 AC COD, which was 48,000 ppm at the start of electrolysis, was able to be reduced to about 800 ppm after two-time electrolysis.

同じ条件でバッチ電解処理を１回行なつたが、安定した
結果が得られた。電解後の電極もなく、表面状態の変化
もまつたく認められなかつた。Batch electrolytic treatment was performed once under the same conditions, and stable results were obtained. There were no electrodes after electrolysis, and no change in surface condition was observed at all.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の電極の断面図てあり、第２図はエキス
パンド板のＬＷＤ，．ＳＷＤｌストランド幅、板厚を示
す図である。 １・・・・・チタン基板、２・・・・・・第１のエキス
パンド板、３・・・・・・第２のエキスパンド板、４・
・・・・中間層、５・・・・・・二酸化鉛層、ＬＷＤ・
・・・・・対角線長辺寸法、ＳＷＤ・・・・・・対角線
短辺寸法、Ｗ・・・・・・ストランド幅、Ｔ・・・・・
・板厚。FIG. 1 is a sectional view of the electrode of the present invention, and FIG. 2 is an expanded plate LWD, . FIG. 3 is a diagram showing the SWDl strand width and plate thickness. 1... Titanium substrate, 2... First expanded plate, 3... Second expanded plate, 4...
...Middle layer, 5...Lead dioxide layer, LWD.
...Diagonal long side dimension, SWD...Diagonal short side dimension, W...Strand width, T...
・Plate thickness.

Claims (1)

【特許請求の範囲】[Claims] １ チタン基板表面上に溶接された菱形の対角線長辺寸
法および短辺寸法がそれぞれ０．５〜５ｍｍと０．５〜
２．５ｍｍの範囲から成り、かつストランド幅および板
厚がそれぞれ０．１〜１ｍｍと０．０５〜０．６ｍｍの
範囲から成る第１のチタン製エキスバンド板と、前記エ
キスバンド板上に溶接された菱形の対角線長辺寸法およ
び短辺寸法がそれぞれ２０〜６０ｍｍと１０〜３０ｍｍ
の範囲からなり、かつストランド幅および板厚がそれぞ
れ１．０〜２．５ｍｍの範囲から成る第２のチタン製エ
キスバンド板と、前記第１、第２のエキスバンド板上に
被覆された白金族金属、それらの合金および酸化物の中
から選ばれた、少なくとも１種の中間層と、前記中間層
上に電着された二酸化鉛とから成ることを特徴とする電
解用二酸鉛被覆電極。1 The diagonal long side and short side of the rhombus welded on the titanium substrate surface are 0.5 to 5 mm and 0.5 to 5 mm, respectively.
A first titanium expanded plate having a strand width of 2.5 mm and a strand width and a plate thickness of 0.1 to 1 mm and 0.05 to 0.6 mm, respectively, and welded onto the expanded band plate. The diagonal long side and short side of the diamond shape are 20 to 60 mm and 10 to 30 mm, respectively.
a second titanium expanded plate having a strand width and a thickness ranging from 1.0 to 2.5 mm; and platinum coated on the first and second expanded plates. A lead dioxide-coated electrode for electrolysis, characterized by comprising at least one intermediate layer selected from group metals, their alloys and oxides, and lead dioxide electrodeposited on the intermediate layer. .