JPH10287999A - Method for supplying zinc ion to zinc-nickel alloy electroplating bath and device therefor - Google Patents
Method for supplying zinc ion to zinc-nickel alloy electroplating bath and device thereforInfo
- Publication number
- JPH10287999A JPH10287999A JP9885197A JP9885197A JPH10287999A JP H10287999 A JPH10287999 A JP H10287999A JP 9885197 A JP9885197 A JP 9885197A JP 9885197 A JP9885197 A JP 9885197A JP H10287999 A JPH10287999 A JP H10287999A
- Authority
- JP
- Japan
- Prior art keywords
- metal
- plating solution
- counter electrode
- plate
- alloy electroplating
- 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.)
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Links
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- Electroplating And Plating Baths Therefor (AREA)
Abstract
Description
【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【０００１】[0001]
【発明の属する技術分野】本発明は、不溶性陽極を用い
る硫酸浴によるＺｎ−Ｎｉ系合金電気メッキ装置のメッ
キ浴槽からの循環メッキ液を金属Ｚｎの溶解槽に通し、
メッキ液中に金属Ｚｎを溶解させてＺｎイオンを供給す
るに際し、Ｎｉの置換析出によるＺｎ溶解速度の低下や
Ｎｉスラッジの発生のない金属Ｚｎの溶解方法及び装置
に関する。[0001] The present invention relates to a method for passing a circulating plating solution from a plating bath of a Zn-Ni-based alloy electroplating apparatus using a sulfuric acid bath using an insoluble anode through a bath for dissolving metallic Zn.
The present invention relates to a method and an apparatus for dissolving metal Zn, in which when dissolving metal Zn in a plating solution and supplying Zn ions, the Zn dissolution rate is not reduced due to displacement precipitation of Ni and Ni sludge is not generated.
【０００２】[0002]
【従来の技術】Ｚｎ−Ｎｉ系合金電気メッキ鋼板は、従
来の亜鉛メッキ鋼板に比較して耐食性に優れ、自動車は
じめ各種用途で使用されている。鋼帯に対して連続的に
Ｚｎ−Ｎｉ系合金メッキを施すには、通常、鉛系または
イリジウム系の不溶性アノードを使用し、メッキ浴とし
ては、硫酸系の浴が使用される。メッキで消費されるイ
オンは、金属または酸化物または各種の塩で供給され
る。コスト的には金属を溶解してイオンを供給する方法
が最も有効であることは言うまでもない。2. Description of the Related Art Zn-Ni alloy electroplated steel sheets have excellent corrosion resistance as compared with conventional galvanized steel sheets and are used in various applications such as automobiles. In order to continuously coat a steel strip with a Zn-Ni-based alloy, a lead-based or iridium-based insoluble anode is usually used, and a sulfuric acid-based bath is used as a plating bath. The ions consumed in the plating are supplied as metal or oxide or various salts. Needless to say, the method of supplying ions by dissolving the metal is the most effective in terms of cost.
【０００３】Ｚｎイオンを金属Ｚｎの溶解によって供給
することは、Ｚｎのメッキでの使用量が多いこともあっ
て最大の課題である。しかし、Ｎｉイオンの共存するメ
ッキ液中に金属Ｚｎを溶解させようとすると、Ｚｎに対
して電気化学的に貴なＮｉが析出し、これが金属Ｚｎを
覆うため溶解速度が著しく低下してしまうという問題が
生じる。析出したＮｉの一部は再溶解するものの、溶解
しきれなかったものはスラッジとして残り、Ｎｉ原単位
の悪化や押しキズ発生等の品質不良を引き起こす原因と
もなる。[0003] Supplying Zn ions by dissolving metallic Zn is the biggest problem because of the large amount of Zn used in plating. However, when trying to dissolve metallic Zn in a plating solution in which Ni ions coexist, Ni that is electrochemically noble with respect to Zn precipitates and covers the metallic Zn, so that the dissolution rate is significantly reduced. Problems arise. Although a part of the precipitated Ni is re-dissolved, the one that has not been completely dissolved remains as sludge, which may cause deterioration of the Ni basic unit and occurrence of poor quality such as generation of a push flaw.
【０００４】この問題の解決のための方法として、例え
ば特開平５−２２２５９７号公報や、特開平６−８１１
９９号公報では、金属Ｚｎの比表面積とメッキ浴温を特
定の範囲に制御することにより、金属Ｚｎの効率的溶解
を図る方法が開示されている。しかし本発明者等の検討
の結果、この方法は、浴中のＮｉ濃度が低い場合のみ有
効であり、実用的なＮｉ濃度のメッキ液で溶解する場合
は、Ｎｉの置換析出による損失が大きく、有効な方法と
は言えない。また、特開平６−２００４００号公報で
は、メッキ浴にクエン酸等のオキシ酸またはオキシ酸塩
を添加し、Ｎｉイオンを錯塩としてトラップし、金属Ｚ
ｎ溶解時のＮｉ置換析出を抑制する方法が開示されてい
る。この方法では、添加するオキシ酸の濃度管理が煩雑
であり、スラッジの発生やメッキ性能への悪影響も懸念
されるし、またコスト的にも有利とは言い難い。As a method for solving this problem, for example, JP-A-5-222597 and JP-A-6-811
No. 99 discloses a method of controlling the specific surface area of the metal Zn and the plating bath temperature to be in specific ranges to thereby efficiently dissolve the metal Zn. However, as a result of investigations by the present inventors, this method is effective only when the Ni concentration in the bath is low, and when dissolving with a plating solution having a practical Ni concentration, the loss due to displacement precipitation of Ni is large, It is not an effective method. In Japanese Patent Application Laid-Open No. 6-200400, an oxyacid such as citric acid or an oxyacid salt is added to a plating bath, Ni ions are trapped as a complex salt, and metal Z is added.
A method for suppressing the precipitation of Ni substitution during the dissolution of n is disclosed. In this method, the control of the concentration of the added oxyacid is complicated, and there is a fear that sludge is generated and the plating performance is adversely affected.
【０００５】さらに、特開平４−３６２２００号公報お
よび特開平５−９７９９号公報では、金属Ｚｎを保持し
たバスケットと対極を隔膜を介して溶解槽中に保持し、
バスケット側にメッキ液を通すとともに対極側に酸溶液
を通し、バスケット側を陽極として通電して溶解する方
法が示されている。この方法では、Ｚｎ上へのＮｉ析出
は防止でき、対極への金属の析出もないが、電力コスト
的に有利とは言えず、電極や隔膜の設備の維持管理も煩
雑でランニングコストの負荷も大きい。また、陰極側に
流通する酸水溶液の管理も必要となる。Further, in JP-A-4-362200 and JP-A-5-9799, a basket holding a metal Zn and a counter electrode are held in a melting tank via a diaphragm,
A method is shown in which a plating solution is passed through the basket side and an acid solution is passed through the counter electrode side, and the basket side is used as an anode to dissolve by energizing. In this method, Ni deposition on Zn can be prevented, and no metal is deposited on the counter electrode. However, this method is not advantageous in terms of power cost. large. In addition, it is necessary to control the acid aqueous solution flowing to the cathode side.
【０００６】[0006]
【発明が解決しようとする課題】以上のように従来行わ
れているＺｎ−Ｎｉ系合金電気メッキにおける金属Ｚｎ
の溶解方法は、 （ア）化学溶解の物理的条件を厳しくする。 （イ）添加剤によってＮｉ析出を抑えながら溶解する。 （ウ）通電溶解により電気化学的にＮｉ析出を抑えて溶
解する。 の３つに大別できる。（ア）の方法では、Ｎｉ析出が避
けられず、（イ）の方法では、Ｎｉ析出は避けられるも
のの、メッキ品質への添加剤の影響が未知であり、いず
れも有効な手段とは言えない。（ウ）の方法は、Ｎｉ析
出が避けられ、メッキ品質への悪影響もないことから最
も有効な方法であるが、通電溶解であるが故に複雑な設
備が必要で、操業コスト、設備コストの負荷が大きいと
いう問題がある。As described above, the metal Zn in the conventional Zn-Ni-based alloy electroplating is used.
(1) The physical conditions of chemical dissolution are strict. (A) The additive dissolves while suppressing Ni precipitation. (C) Dissolution while suppressing Ni deposition electrochemically by energizing dissolution. Can be roughly divided into three. In the method (A), Ni precipitation cannot be avoided, and in the method (A), Ni precipitation can be avoided, but the effect of the additive on the plating quality is unknown, and neither can be said to be an effective means. . The method (c) is the most effective method because the precipitation of Ni is avoided and there is no adverse effect on the plating quality. There is a problem that is large.
【０００７】以上に鑑み、本発明は、Ｎｉの置換析出を
有効に防止し、なおかつ隔膜等の複雑な設備を必要とせ
ず、簡便でコスト的に有利な、硫酸浴Ｚｎ−Ｎｉ系合金
メッキ浴におけるＺｎイオンの供給方法とその装置を提
供することを目的とする。In view of the above, the present invention provides a sulfuric acid bath Zn-Ni-based alloy plating bath which effectively prevents the substitutional precipitation of Ni, does not require complicated equipment such as a diaphragm, and is simple and cost-effective. It is an object of the present invention to provide a Zn ion supply method and an apparatus therefor.
【０００８】[0008]
【課題を解決するための手段】本発明者等は、Ｚｎ−Ｎ
ｉ系合金メッキ浴中での金属Ｚｎの溶解現象を支配する
原理・原則を理解するため、電気化学的な考察、検証を
行った。その結果、得られた結論を以下に記す。Means for Solving the Problems The present inventors have proposed Zn-N
In order to understand the principle governing the dissolution phenomenon of metal Zn in the i-based alloy plating bath, electrochemical considerations and verifications were performed. The conclusions obtained as a result are described below.
【０００９】図１および図２にそれぞれ、Ｚｎ、Ｎｉの
電位−ｐＨ図を示す（MARCEL POURBAIX 著“ATLS OF EL
ECTROCHEMICAL EQUILIBRIA”より引用）。また、溶解時
に起きている素反応について下記の（１）〜（３）式に
示す。 Ｚｎ＝Ｚｎ2+＋２ｅ- （１） Ｎｉ＝Ｎｉ2+＋２ｅ- （２） ２Ｈ+ ＋ ２ｅ- ＝Ｈ2 （３） 溶解初期の金属Ｚｎ上の電位は実測の結果、ほぼ（１）
式で示されるＺｎの酸化還元電位である−０．８Ｖ（対
ＮＨＥ）付近にあり、この電位においては、Ｎｉイオン
は、図２の電位−ｐＨ図が示唆するとおり、イオンとし
ては安定でいられなくなるため金属として析出し、この
ことが金属Ｚｎ溶解を困難にする原因の根本であること
がわかった。そこで安定した溶解を維持するためには、
溶解時の金属Ｚｎ上の電位を（２）式で示されるＮｉの
酸化還元電位よりも常に高く保つ必要がある。FIG. 1 and FIG. 2 show the potential-pH diagrams of Zn and Ni, respectively (MARCEL POURBAIX, “ATLS OF EL”).
ECTROCHEMICAL EQUILIBRIA "). The elementary reactions occurring during dissolution are shown in the following formulas (1) to (3). Zn = Zn 2+ + 2e − (1) Ni = Ni 2+ + 2e − (2) 2H + + 2e − = H 2 (3) As a result of the actual measurement, the potential on the metal Zn in the initial stage of dissolution is almost (1)
The oxidation-reduction potential of Zn represented by the formula is around -0.8 V (vs. NHE). At this potential, Ni ions are not stable as ions as suggested by the potential-pH diagram of FIG. Since it is no longer possible to deposit metal as a metal, it was found that this is the root of the cause of the difficulty in dissolving metal Zn. Therefore, in order to maintain stable dissolution,
It is necessary to keep the potential on the metal Zn during melting higher than the oxidation-reduction potential of Ni represented by the formula (2).
【００１０】先行技術で取り上げた特開平４−３６２２
００号公報および特開平５−９７９９号公報のＮｉ析出
防止効果について、以上のような電気化学的見地から見
ると、金属Ｚｎをアノードとして通電溶解することでＺ
ｎ上の電位を（２）式以上に保ち、Ｎｉの析出を防止し
ている、と解釈でき、Ｚｎ上の電位を制御することが安
定した溶解を行う上で極めて重要であることがわかる。
一方、特開平４−３６２２００号公報および特開平５−
９７９９号公報では、対極側で（３）式に示す水素発生
が起こっており、電気溶解であるがため、既に述べた電
力コストの負荷や隔膜といった複雑な設備を回避するこ
とができない。[0010] Japanese Patent Application Laid-Open No. Hei 4-3622, which was mentioned in the prior art.
No. 00 and JP-A-5-9799, from the electrochemical point of view as described above, it is found that Zr is obtained by dissolving a metal Zn as an anode and conducting electricity.
It can be interpreted that the potential on n is maintained at or above the formula (2) to prevent precipitation of Ni, and it is understood that controlling the potential on Zn is extremely important for stable dissolution.
On the other hand, JP-A-4-362200 and JP-A-5-362
In Japanese Patent No. 9799, hydrogen generation represented by the formula (3) occurs on the counter electrode side, and electrolysis is performed. Therefore, complicated facilities such as the load of power cost and the diaphragm described above cannot be avoided.
【００１１】本発明者等は、これについて更に検討を進
めた結果、Ｚｎ上の電位を（２）式のＮｉ析出が起こる
電位以上に保持しつつ、なおかつ、同じＺｎ上で（３）
式の水素発生も同時に起こる状況を創り出せば、Ｎｉ析
出が防止でき、Ｚｎの効率的溶解が可能で、しかもこの
場合通電溶解ではない化学的な溶解が実現するため、安
価で簡単な設備で溶解することができるとの結論に至っ
た。すなわち、図２の斜線で示した、Ｎｉの酸化還元電
位よりも高く、水素発生電位よりも低い領域において
は、原理原則としてＮｉをいっさい析出させることな
く、Ｚｎの溶解が化学的に可能である。本発明者等は、
以上の平衡論的示唆を実際の金属Ｚｎ溶解に適用し、具
現化する方法を鋭意検討した結果、本発明の完成に至っ
たものである。As a result of further study of the present inventors, the present inventors have found that while maintaining the potential on Zn to be equal to or higher than the potential at which Ni precipitation occurs in the formula (2), the same holds true for (3) on the same Zn.
By creating a situation in which hydrogen generation in the formula also occurs at the same time, Ni precipitation can be prevented, Zn can be efficiently dissolved, and in this case, chemical dissolution rather than electric dissolution is realized, so it is inexpensive and simple equipment It was concluded that it could be dissolved. That is, in the region shown by the oblique lines in FIG. 2 that is higher than the oxidation-reduction potential of Ni and lower than the hydrogen generation potential, dissolution of Zn is chemically possible without precipitating any Ni in principle. . The present inventors,
The present inventors have completed the present invention as a result of earnestly studying a method of applying the above equilibrium suggestion to actual dissolution of metallic Zn and realizing it.
【００１２】すなわち本発明の第１は、不溶性陽極を用
いたｐＨ４以下の硫酸浴によるＺｎ−Ｎｉ系合金電気メ
ッキ装置のメッキ浴槽からの循環メッキ液を金属Ｚｎの
溶解槽に通し、メッキ液中に金属Ｚｎを溶解させてＺｎ
イオンを供給する方法において、金属Ｚｎ上の電位（対
ＮＨＥ）を下記第式の範囲内にすることを特徴とする
Ｚｎ−Ｎｉ系合金メッキ浴へのＺｎイオンの供給方法で
ある。 −０．３１４＋０．０４５×（ｐＨ）＜金属Ｚｎ表面上の電位＜−０．０５９ ×（ｐＨ） ・・・That is, a first aspect of the present invention is that a circulating plating solution from a plating bath of a Zn—Ni alloy electroplating apparatus using a sulfuric acid bath having a pH of 4 or less using an insoluble anode is passed through a bath for dissolving metallic Zn. Dissolve metal Zn in Zn
In the method for supplying ions, a potential (on NHE) on metal Zn is set within a range of the following formula, and the method for supplying Zn ions to a Zn—Ni-based alloy plating bath is provided. −0.314 + 0.045 × (pH) <potential on metal Zn surface <−0.059 × (pH)
【００１３】本発明の第２、第３は、上記第１の発明を
実現する具体的方法に関し、第２は、金属Ｚｎの溶解槽
に対極と参照極を設け、金属Ｚｎと対極間に電圧を印加
し、参照極によって対極と対面する金属Ｚｎ表面上の電
位を測定し、金属Ｚｎと対極間の電圧を操作して、対極
と対面する金属Ｚｎ表面上の電位（対ＮＨＥ）を第式
の範囲内にすることを特徴とする本発明の第１に記載の
Ｚｎ−Ｎｉ系合金電気メッキ浴へのＺｎイオンの供給方
法であり、第３は、金属Ｚｎの溶解槽に対極を設け、金
属Ｚｎをアノードとして金属Ｚｎ、対極間に０．００１
〜０．２A/dm2の微弱電流を流すと共に、対極と対面す
る金属Ｚｎ表面上を流通するメッキ液の硫酸濃度を１０
g/l 以上とし、そのメッキ液の流速を０．５m/min 以上
にすることにより、対極と対面する金属Ｚｎ表面上の電
位（対ＮＨＥ）を第式の範囲内にすることを特徴とす
る本発明の第１に記載のＺｎ−Ｎｉ系合金電気メッキ浴
へのＺｎイオンの供給方法である。The second and third aspects of the present invention relate to a specific method for realizing the first aspect of the present invention. The second aspect is that a counter electrode and a reference electrode are provided in a melting tank for metal Zn, and a voltage is applied between the metal Zn and the counter electrode. Is applied, the potential on the metal Zn surface facing the counter electrode is measured by the reference electrode, and the voltage between the metal Zn and the counter electrode is manipulated to calculate the potential on the metal Zn surface facing the counter electrode (vs. NHE) according to the following equation. The present invention provides a method for supplying Zn ions to a Zn-Ni-based alloy electroplating bath according to the first aspect of the present invention, wherein a counter electrode is provided in a metal Zn melting tank, Metal Zn as anode, metal Zn, 0.001 between counter electrodes
And a sulfuric acid concentration of the plating solution flowing on the surface of the metal Zn facing the counter electrode of 10 to 0.2 A / dm 2.
g / l or more, and the flow rate of the plating solution is 0.5 m / min or more, so that the potential (on NHE) on the metal Zn surface facing the counter electrode is within the range of the following equation. 1 is a method for supplying Zn ions to a Zn-Ni-based alloy electroplating bath according to the first aspect of the present invention.
【００１４】また、本発明の第４は、上記本発明の第２
又は第３の溶解速度を高める方法で、本発明の第５は上
記本発明の第２又は第３の金属Ｚｎの溶解残りを無くす
る方法である。本発明の第６、８、１０（７、９、１
１）は本発明の第３、且つ第４（５）の方法を実施する
ための装置である。A fourth aspect of the present invention is the second aspect of the present invention.
Alternatively, the fifth method of the present invention is a method of increasing the third dissolution rate, and the fifth method of the present invention is a method of eliminating the undissolved residue of the second or third metal Zn of the present invention. The sixth, eighth, tenth (7, 9, 1) of the present invention
1) is an apparatus for implementing the third and fourth (5) methods of the present invention.
【００１５】一般的なＺｎ−Ｎｉ系合金メッキ浴は、ｐ
Ｈ４以下、浴温３０〜７０℃程度の硫酸浴である。ここ
でＺｎ−Ｎｉ系合金メッキ浴というのは、金属イオンと
してＺｎおよびＮｉのみを含む場合と、これに加えてＣ
ｏ等の第３元素を含む場合の両方を言う。このような浴
中で金属Ｚｎの溶解を行った場合、図３に一例を示すよ
うに溶解初期には十分な溶解速度が得られるものの、す
ぐに溶解速度の著しい低下が起きる。このような低下が
起きる原因は、既に述べているように金属Ｎｉが置換析
出し、金属Ｚｎの周りを覆い反応点をふさいでしまうか
らである。析出したＮｉを物理的に剥ぎ落としてやる
と、溶解速度は再度初期のレベルにまで復活するもの
の、また初めと同様に低下する。一度析出したＮｉは、
スラッジとして残り、Ｎｉ原単位の悪化ばかりでなく、
メッキ浴槽に流入した場合には、押しキズ等の品質不良
を引き起こす。したがって、いかに析出Ｎｉを少なくす
るかが課題となる。A general Zn—Ni-based alloy plating bath is p
It is a sulfuric acid bath having a bath temperature of about 30 to 70 ° C. at H4 or lower. Here, the Zn-Ni-based alloy plating bath refers to a case where only Zn and Ni are contained as metal ions,
Both include cases where a third element such as o is included. When metal Zn is dissolved in such a bath, a sufficient dissolution rate can be obtained in the initial stage of dissolution as shown in an example in FIG. The reason why such a decrease occurs is that, as already described, metal Ni is substitutionally precipitated and covers the metal Zn and blocks the reaction point. If the precipitated Ni is physically stripped off, the dissolution rate will be restored to the initial level again, but will decrease as before. Once deposited Ni,
It remains as sludge and not only deteriorates Ni basic unit,
When flowing into the plating bath, poor quality such as a push flaw is caused. Therefore, it is an issue how to reduce the amount of precipitated Ni.
【００１６】次に、金属Ｚｎ上の電位を種々変化させて
溶解を行い、反応後Ｚｎ表面に析出したＮｉおよび溶解
槽下部に残滓として溜まったＮｉを定量した。具体的に
は、図４に示すように、金属Ｚｎ溶解槽１のメッキ液２
中に対極４および金属Ｚｎ板３の下部を浸漬し、対極
面、金属Ｚｎ板の板面が所定距離を存して対向するよう
に保持し、金属Ｚｎ板３および対極４の上部の間に電源
８により電圧を印加し、塩橋５、参照極６および電位差
計７によって対極４と対向するメッキ液中の金属Ｚｎ板
３上の電位を電位差計７で測定可能とし、金属Ｚｎ板３
と対極４間の電圧を操作して、上記金属Ｚｎ板３上の電
位（対ＮＨＥ）を変化させ、かつ飽和カロメル電極を参
照極とし、Ｐｔを対極として実験を行った。メッキ液濃
度条件は次のとおりである。 （メッキ液濃度） ＺｎＳＯ4 ７Ｈ2 Ｏ；１８０g/l ＮｉＳＯ4 ６Ｈ2 Ｏ；１００，２５０，４００g/l Ｎａ2 ＳＯ4 ；１００g/l Ｈ2 ＳＯ4 ；２５g/l ｐＨ＝１．０Next, melting was performed by changing the potential on the metal Zn in various ways, and Ni precipitated on the Zn surface after the reaction and Ni accumulated as residue in the lower portion of the melting tank were quantified. Specifically, as shown in FIG.
The counter electrode 4 and the lower portion of the metal Zn plate 3 are immersed therein, and the counter electrode surface and the plate surface of the metal Zn plate are held so as to face each other at a predetermined distance, and between the metal Zn plate 3 and the upper portion of the counter electrode 4. A voltage is applied by a power supply 8, and the potential on the metal Zn plate 3 in the plating solution facing the counter electrode 4 can be measured by the potentiometer 7 by the salt bridge 5, the reference electrode 6 and the potentiometer 7.
The experiment was performed by changing the potential (on NHE) on the metal Zn plate 3 by operating the voltage between the electrode and the counter electrode 4, using a saturated calomel electrode as a reference electrode, and using Pt as a counter electrode. The plating solution concentration conditions are as follows. (Plating solution concentration) ZnSO 4 7H 2 O; 180 g / l NiSO 4 6H 2 O; 100, 250, 400 g / l Na 2 SO 4 ; 100 g / l H 2 SO 4 ; 25 g / l pH = 1.0
【００１７】図５に結果を示す。Ｚｎの浸漬電位に相当
する−０．８Ｖ（対ＮＨＥ）付近では、多量の金属Ｎｉ
が析出し、その量は浴中のＮｉ濃度の増加とともに増大
した。電位を上げていくと析出Ｎｉ量は減少し、電位が
−０．２５Ｖを上回ると、浴中Ｎｉ濃度によらず、Ｎｉ
の析出が無くなることが判明した。次に、Ｎｉ濃度を４
００g/l に固定し、ｐＨを０〜３に変化させて同様に行
い、Ｎｉ析出がゼロになる電位を求め、ｐＨに対してプ
ロットしたものを図６に示す。ｐＨが低いほど析出Ｎｉ
量が少なく、また析出がゼロになる電位がｐＨが低いほ
ど低いことが判明した。これはｐＨが低いほど一度析出
したＮｉの再溶解が起こりやすいためと推定している。
図６からＮｉ析出が起こらなくなる範囲として、 −０．３１４＋０．０４５×（ｐＨ）＜Ｚｎ電位 を規定した。FIG. 5 shows the results. Near -0.8 V (vs. NHE), which corresponds to the immersion potential of Zn, a large amount of metallic Ni
Was precipitated, and the amount increased with an increase in the Ni concentration in the bath. When the potential is increased, the amount of precipitated Ni decreases. When the potential exceeds -0.25 V, Ni is reduced regardless of the Ni concentration in the bath.
It was found that the precipitation of was eliminated. Next, the Ni concentration was set to 4
The same procedure was carried out while fixing the pressure at 00 g / l and changing the pH to 0 to 3. The potential at which Ni precipitation was zero was determined and plotted against pH. The lower the pH, the more Ni
It was found that the potential at which the amount was small and the precipitation became zero was lower as the pH was lower. This is presumed to be because the lower the pH, the more easily the Ni precipitated once becomes redissolved.
As shown in FIG. 6, −0.314 + 0.045 × (pH) <Zn potential is defined as a range in which Ni precipitation does not occur.
【００１８】一方、電位を更に上げていくと、ある時点
からＺｎ上での水素発生が停止してしまい、化学溶解で
はなく、通電溶解に変化してしまう。この電位の上限
は、液のｐＨに依存し、以下式の関係にある。 Ｚｎ電位＜−０．０５９×（ｐＨ）On the other hand, if the potential is further increased, the generation of hydrogen on Zn stops at a certain point, and it changes to chemical dissolution instead of chemical dissolution. The upper limit of this potential depends on the pH of the solution, and has the following relationship. Zn potential <−0.059 × (pH)
【００１９】以上の検討に基づき、Ｚｎ上にＮｉを置換
析出させることなく、かつＺｎ上で水素発生が起こり、
Ｚｎの化学溶解を進行させるための電位として以下範囲
を規定した。 −０．３１４＋０．０４５×（ｐＨ）＜Ｚｎ電位＜−
０．０５９×（ｐＨ）Based on the above study, hydrogen is generated on Zn without substituting and depositing Ni on Zn,
The following range was defined as the potential for promoting the chemical dissolution of Zn. −0.314 + 0.045 × (pH) <Zn potential <−
0.059 × (pH)
【００２０】また図４の装置において、対極４と対向す
る金属Ｚｎの表面を金属Ｚｎ板の板面とするよりも、金
属Ｚｎ板の積層体の積層板厚面とする方が溶解速度が大
きくなることが判明した。更に、図４のように金属Ｚｎ
３の下部をメッキ液中に浸漬保持すると、液面より上方
の金属Ｚｎ部分は溶解されないため解け残りが生じる
が、Ｔｉバスケットの下部をメッキ液中に浸漬保持し、
メッキ液中のＴｉバスケット内に金属Ｚｎ粒、金属Ｚｎ
板、金属Ｚｎインゴット等を充填することで金属Ｚｎの
解け残りをなくすることができ、原料コストを低減でき
る。In the apparatus shown in FIG. 4, the dissolution rate is higher when the surface of the metal Zn facing the counter electrode 4 is a thick plate of the laminate of the metal Zn plates than a plate surface of the metal Zn plate. It turned out to be. Further, as shown in FIG.
When the lower part of No. 3 is immersed and held in the plating solution, the metal Zn portion above the liquid surface is not melted and unmelted remains, but the lower part of the Ti basket is immersed and held in the plating solution.
Metal Zn particles, metal Zn in Ti basket in plating solution
By filling a plate, a metal Zn ingot, or the like, unmelted metal Zn can be eliminated, and the raw material cost can be reduced.
【００２１】不溶性陽極を用いたｐＨ４以下の硫酸浴に
よるＺｎ−Ｎｉ系合金電気メッキ装置のメッキ浴槽から
の循環メッキ液を金属Ｚｎの溶解槽に通し、メッキ液中
に金属Ｚｎを溶解させてＺｎイオンを供給する方法にお
いて、上記方法を適用する場合は、図７に示したメッキ
浴槽、例えば水平に走行するストリップ１０の上下面に
対向して、ストリップ面に向かってメッキ液を噴出させ
るスリットを有する静圧流体支持パッドと、このパッド
のストリップ走行方向の両側に電気的に絶縁された左右
一対の不溶性陽極を配置し、これら陽極のストリップ入
側部と出側部にメッキ液の流出口を形成し、これら流出
口の直前、直後に設けたコンダクターロールとからなる
ストリップの水平型流体支持メッキセル９と、メッキ液
循環タンク１２と、金属Ｚｎ溶解槽１１とからなる電気
メッキ設備の金属Ｚｎ溶解槽部分に、図４の金属Ｚｎ溶
解装置を導入すればよい。A circulating plating solution from a plating bath of a Zn—Ni-based alloy electroplating apparatus using a sulfuric acid bath having a pH of 4 or less using an insoluble anode is passed through a dissolution tank for metal Zn to dissolve the metal Zn in the plating solution. In the method of supplying ions, when the above method is applied, a plating bath shown in FIG. 7, for example, a slit for jetting a plating solution toward the strip surface is provided opposite to the upper and lower surfaces of the horizontally running strip 10. A static pressure fluid support pad having, and a pair of electrically insulated left and right insoluble anodes arranged on both sides of the pad in the strip running direction, and a plating solution outlet on the strip entrance side and the exit side of these anodes. And a horizontal fluid-supporting plating cell 9 of strip consisting of conductor rolls provided immediately before and immediately after these outlets; The metal Zn dissolution tank portion of the electroplating equipment comprising a metal Zn dissolving tank 11 Prefecture, may be introduced metal Zn dissolution apparatus of FIG.
【００２２】なお図７では、金属Ｚｎ溶解装置はメッキ
浴槽（メッキセル）−循環タンクのメッキ液の循環系統
とは別に循環タンク１２とでメッキ液の循環系統を形成
するように設けているが、メッキセル（メッキ浴槽）−
循環タンクのメッキ液の循環系統中に配置してもよい。
さらに、図４の金属Ｚｎ溶解装置を図７の電気メッキ設
備に導入するに際し、対極は、不溶性のＰｂ、Ｔｉ、参
照極は銀／塩化銀電極であってよい。また、金属Ｚｎは
上記金属Ｚｎ板の積層体、Ｔｉバスケットに充填した金
属Ｚｎであってよい。尚、図７において、１３はメッキ
液循環ポンプ、１４は流量調整バルブを示す。In FIG. 7, the metal Zn dissolving apparatus is provided so as to form a plating solution circulation system with the circulation tank 12 separately from the plating bath (plating cell) -circulation tank circulation system. Plating cell (plating bath)
It may be arranged in the circulation system of the plating solution in the circulation tank.
Further, when introducing the metal Zn melting apparatus of FIG. 4 into the electroplating equipment of FIG. 7, the counter electrode may be insoluble Pb and Ti, and the reference electrode may be a silver / silver chloride electrode. Further, the metal Zn may be a stacked body of the metal Zn plate or metal Zn filled in a Ti basket. In FIG. 7, 13 denotes a plating solution circulation pump, and 14 denotes a flow rate adjusting valve.
【００２３】金属Ｚｎ溶解装置が大規模になってくる
と、反応開始からの時間変化、およびＺｎの位置によっ
て電位のバラツキが大きくなってくるので、上記の方法
によってある一点の電位を規定しても、他の点での電位
が目標どおりにならず、金属Ｎｉが析出してしまう場合
がある。また、塩橋、参照極といった装置は非常にデリ
ケートであり、腐食環境の強い溶解槽付近で使用するに
は、維持管理にかかる負荷が大きい。これらについて改
善策を検討した結果、経時変化や位置によって電位がバ
ラツク原因は、溶解反応に伴う金属Ｚｎ上の反応場のｐ
Ｈの増加やＺｎ濃度の増加等の濃度バラツキが生じるこ
とによることが判明し、これを避けるためには、メッキ
液を流通し、金属Ｚｎに対して常に新しい液を接触させ
ることが重要であることが判明した。また、塩橋、参照
極により電位を測定しなくても、対極と対面する金属Ｚ
ｎ表面上を流通するメッキ液の硫酸濃度と、そのメッキ
液の流速、および金属Ｚｎと対極間の電流密度を規定す
ることにより、金属Ｚｎ表面上の電位を既に述べたＮｉ
析出の起きない化学溶解範囲の電位に保つことが可能で
あることが判明した。When the size of the metal Zn dissolving apparatus becomes large, the variation of the potential becomes large depending on the time change from the start of the reaction and the position of Zn. Therefore, the potential at one point is defined by the above method. Also, the potential at other points may not reach the target, and metal Ni may be deposited. In addition, devices such as a salt bridge and a reference electrode are very delicate, and when used near a melting tank having a strong corrosive environment, the load on maintenance is large. As a result of studying improvement measures for these, the cause of the potential variation depending on the change with time and the position is due to the p of the reaction field on the metal Zn accompanying the dissolution reaction.
It has been found that concentration variations such as an increase in H and an increase in Zn concentration occur, and in order to avoid this, it is important to distribute a plating solution and always contact a new solution with metal Zn. It has been found. In addition, even if the potential is not measured by the salt bridge and the reference electrode, the metal Z facing the counter electrode can be used.
By defining the sulfuric acid concentration of the plating solution flowing on the n surface, the flow rate of the plating solution, and the current density between the metal Zn and the counter electrode, the potential on the surface of the metal Zn was reduced to the level of Ni as described above.
It has been found that it is possible to maintain the potential in the chemical dissolution range where precipitation does not occur.
【００２４】対極と対面する金属Ｚｎ表面上を流通する
メッキ液の硫酸濃度は、１０g/l 以上、好ましくは１５
g/l 以上必要であり、これより低い場合には、Ｚｎ溶解
反応に伴う反応場でのｐＨ変化が大きく、電位のバラツ
キが大きくなってしまう。対極と対面する金属Ｚｎ表面
上を流通するメッキ液の流速は、硫酸濃度以上に重要で
あり、０．５m/min 以上の流速が必要である。これより
も流速が小さいと、金属Ｚｎ表面上の反応場への硫酸供
給が不足し、また反応場で増加したＺｎイオンが拡散し
にくいため、電位のバラツキが大きくなってしまう。金
属Ｚｎ／対極間には、Ｚｎに対して外部電源からわずか
にＺｎをアノーディックにする方向に電圧を印加すれば
よく、あくまでＺｎ上の電位を所定の電位に保つのが目
的であるから、流れる電流についてはあまり重要ではな
いが、電位を所定値に保つためには、先の硫酸濃度、流
量条件下で０．００１〜０．２A/dm2 の電流密度が必要
である。電流の下限は、Ｎｉ析出が起きない電位を安定
して確保するために必要であり、一方、上限の０．２A/
dm2 を越えると、対極への金属の析出が発生し、逆効果
である。The sulfuric acid concentration of the plating solution flowing over the metal Zn surface facing the counter electrode is 10 g / l or more, preferably 15 g / l or more.
g / l or more is necessary, and if it is lower than this, the change in pH in the reaction field accompanying the Zn dissolution reaction is large, and the variation in potential is large. The flow rate of the plating solution flowing on the metal Zn surface facing the counter electrode is more important than the sulfuric acid concentration, and requires a flow rate of 0.5 m / min or more. If the flow rate is lower than this, the supply of sulfuric acid to the reaction field on the metal Zn surface becomes insufficient, and the Zn ions increased in the reaction field are difficult to diffuse, so that the variation in potential increases. Between the metal Zn and the counter electrode, a voltage may be applied to Zn from an external power supply in a direction to slightly make Zn anodic, and the purpose is to keep the potential on Zn at a predetermined potential. Although the flowing current is not so important, a current density of 0.001 to 0.2 A / dm 2 is required under the above sulfuric acid concentration and flow rate conditions in order to keep the potential at a predetermined value. The lower limit of the current is necessary to stably secure a potential at which Ni precipitation does not occur, while the upper limit of 0.2 A /
When dm 2 is exceeded, metal is deposited on the counter electrode, which is the opposite effect.
【００２５】電源としては、直流整流器が好適であり、
所定電流密度になるように電流値をセットすればよい。
溶解槽に流通するメッキ液の硫酸濃度は、図７において
メッキ液循環タンク内の濃度と同等であるが、溶解槽内
における、対極と対面する金属Ｚｎ表面上を流通するメ
ッキ液の硫酸濃度については、直接測定するのは実際的
には困難である。そこで、溶解槽出側にて硫酸濃度を測
定し、この濃度が所定値以上になるようにメッキ液循環
タンク内の濃度を調整することが実際的には用いられ
る。溶解槽出側での硫酸濃度は、溶解槽内における、対
極と対面する金属Ｚｎ表面上を流通するメッキ液の硫酸
濃度の最低値にほぼ等しいと考えられるからである。溶
解槽へのメッキ液流通量は流量調整バルブの開度で調整
できるが、溶解槽内における、対極と対面する金属Ｚｎ
表面上を流通するメッキ液の流速については、金属Ｚｎ
／対極の間のバルク流速で近似する。このためには、設
備的に金属Ｚｎと対極の間隔を小さく保つ必要がある。
金属Ｚｎ表面上において所定の流速が得られる液流通量
を予め調査しておき、この液流量の値になるように流量
調整バルブの開度を調整するのが最も容易である。As a power source, a DC rectifier is preferable.
What is necessary is just to set a current value so that it may become a predetermined current density.
The sulfuric acid concentration of the plating solution flowing through the dissolving tank is the same as the concentration in the plating solution circulating tank in FIG. 7, but the sulfuric acid concentration of the plating solution flowing on the metal Zn surface facing the counter electrode in the dissolving tank. Is difficult in practice to measure directly. Therefore, it is actually used to measure the concentration of sulfuric acid at the outlet side of the dissolving tank and adjust the concentration in the plating solution circulation tank so that the concentration becomes equal to or higher than a predetermined value. This is because the sulfuric acid concentration at the exit side of the dissolving tank is considered to be substantially equal to the minimum value of the sulfuric acid concentration of the plating solution flowing on the metal Zn surface facing the counter electrode in the dissolving tank. The flow rate of the plating solution to the melting tank can be adjusted by the opening of the flow rate control valve.
Regarding the flow rate of the plating solution flowing on the surface, the metal Zn
/ Approximate with bulk flow rate between counter electrodes. For this purpose, it is necessary to keep the interval between the metal Zn and the counter electrode small in equipment.
It is easiest to investigate in advance the flow rate of the liquid at which a predetermined flow rate can be obtained on the surface of the metal Zn, and to adjust the opening of the flow control valve so as to obtain the value of the liquid flow rate.
【００２６】[0026]
【発明の実施の形態】本発明を実施する金属Ｚｎ溶解装
置例を図８に示す。図８（Ａ）は溶解装置の平面図、図
８（Ｂ）は図８（Ａ）のＸ−Ｘ断面図、図８（Ｃ）は図
８（Ｂ）のＹ−Ｙ断面図、図８（Ｄ）は図８（Ｂ）のＺ
−Ｚ断面図である。FIG. 8 shows an example of a metal Zn melting apparatus for carrying out the present invention. 8A is a plan view of the melting apparatus, FIG. 8B is a sectional view taken along line XX of FIG. 8A, FIG. 8C is a sectional view taken along line YY of FIG. (D) is Z in FIG. 8 (B).
It is -Z sectional drawing.
【００２７】図８の金属Ｚｎ溶解装置例は、図９（Ａ）
に斜視図で示すように、複数の金属Ｚｎ板を積層して積
層体２３としその上部に孔をあけ、この孔に通電棒２４
を挿入し、図８に示すように全面がゴムライニングされ
た溶解槽２１のメッキ液面の上方に配置した２本の通電
用支持棒２５で上記通電棒２４の両端部を支えること
で、金属Ｚｎ板の積層体２３の下部をメッキ液中に浸漬
保持し、対極２７の上端部に設けた対極支持板２９の両
端部を電気絶縁物２８を介して上記２本の導電性支持棒
２５にて支えることで対極２７の下部を、メッキ液中の
金属Ｚｎ板積層体２３下部の積層端面に対向して、メッ
キ液中に浸漬保持し、対極２７と金属Ｚｎ板積層体の積
層端面との間をメッキ液が流れるように溶解槽２１にメ
ッキ液供給口２６および排出口３１を設けると共に、支
持棒２５、通電棒２４を介して金属Ｚｎ板積層体２３を
陽極、対極支持板２９を介して対極２７を陰極とするよ
うに電源（図示せず）に接続したものである。FIG. 9A shows an example of the apparatus for melting metal Zn in FIG.
As shown in a perspective view, a plurality of metal Zn plates are laminated to form a laminate 23, a hole is formed in the upper portion thereof, and a current-carrying rod 24 is formed in the hole.
By supporting both ends of the current-carrying rod 24 with two current-carrying support rods 25 disposed above the plating solution surface of the dissolving tank 21 whose entire surface is rubber-lined as shown in FIG. The lower part of the Zn plate laminate 23 is immersed and held in the plating solution, and both ends of the counter electrode support plate 29 provided on the upper end of the counter electrode 27 are connected to the two conductive support rods 25 via the electric insulator 28. The lower part of the counter electrode 27 is immersed and held in the plating solution facing the lower end surface of the metal Zn plate laminate 23 in the plating solution to support the lower end of the counter electrode 27 and the lamination end surface of the metal Zn plate laminate. A plating solution supply port 26 and a discharge port 31 are provided in the dissolving tank 21 so that the plating solution flows between them, and the metal Zn plate laminate 23 is connected to the anode and the counter electrode support plate 29 via the support rod 25 and the current supply rod 24. Power source (not shown) so that the counter electrode 27 is used as a cathode. Which are connected to.
【００２８】図８の装置例においては、メッキ液供給口
２６から流入するメッキ液が対極２７と金属Ｚｎ板積層
体２３の積層端面との間を下方に向かって流れるように
溶解槽２１内に隔壁２２を設け、隔壁２２下端を水平に
通過したメッキ液は、隔壁２２に沿って上方に向かって
流れ、排出口３１より流出するようになしているが、隔
壁を設けることなくメッキ液が対極と金属Ｚｎ板積層体
の積層端面との間を水平方向に流れるように、溶解槽の
側壁にメッキ液供給口および排出口を設けてもよい。In the example of the apparatus shown in FIG. 8, the plating solution flowing from the plating solution supply port 26 flows downward between the counter electrode 27 and the lamination end face of the metal Zn plate laminate 23 into the dissolution tank 21. The plating solution that has been provided with the partition wall 22 and passed horizontally through the lower end of the partition wall 22 flows upward along the partition wall 22 and flows out from the discharge port 31. A plating solution supply port and a discharge port may be provided on the side wall of the melting tank so that the plating solution flows horizontally between the metal Zn plate laminate and the lamination end face.
【００２９】また本装置例では、必要な金属Ｚｎの溶解
速度（Ｚｎイオンの供給速度）の確保のために、図８
（Ａ）に示すように、溶解槽２１内のメッキ液中に、４
つの対極２７が間隔を存してそれらの下部が浸漬保持さ
れ、対極２７の間に金属Ｚｎ板積層体２３の下部が、浸
漬保持されているが、必要な溶解速度（イオン供給速
度）が確保されるならば、２つの対極の間に１つの金属
Ｚｎ板積層体、あるいは１つの対極と１つの金属Ｚｎ板
積層体の下部がメッキ液中に浸漬保持されてもよい。In this example of the apparatus, in order to secure a necessary dissolution rate of metal Zn (supply rate of Zn ions), FIG.
As shown in FIG.
The lower portions of the two counter electrodes 27 are immersed and held at intervals, and the lower portion of the metal Zn plate laminate 23 is immersed and held between the counter electrodes 27, but a necessary dissolution rate (ion supply rate) is secured. If so, one metal Zn plate laminate or two counter electrodes and one metal Zn plate laminate may be immersed and held in a plating solution between two counter electrodes.
【００３０】更に本装置例では、図９（Ａ）に示すよう
に金属Ｚｎ板を積層して上部に孔をあけ、この孔に通電
棒２４を挿入し、溶解槽２１のメッキ液面の上方に配置
した２本の通電用支持棒２５で上記通電棒２４の両端部
を支えることで、金属Ｚｎ板の積層体２３の下部をメッ
キ液中に浸漬保持しているが、図９（Ｂ）に示すよう
に、Ｔｉバスケット３２の上部にフランジ３３を設け、
溶解槽２１のメッキ液面の上方に配置した２本の通電用
支持棒２５で上記フランジ３３を支えることで、Ｔｉバ
スケット３２の下部をメッキ液中に浸漬保持すると共
に、上記Ｔｉバスケット３２に、金属Ｚｎ粒、金属Ｚｎ
板もしくは金属Ｚｎインゴット３４等を充填し、メッキ
液中に浸漬しない金属Ｚｎを無くし、未溶解金属Ｚｎを
なくするようにしてもよい。Further, in this example of the apparatus, as shown in FIG. 9A, a metal Zn plate is laminated and a hole is formed in the upper part. The lower part of the metal Zn plate laminate 23 is immersed and held in the plating solution by supporting both ends of the current-carrying rods 24 with the two current-carrying support rods 25 arranged in FIG. 9B. As shown in the figure, a flange 33 is provided on the upper part of the Ti basket 32,
The lower part of the Ti basket 32 is immersed and held in the plating solution by supporting the flange 33 with the two current-carrying support rods 25 disposed above the plating solution level of the dissolving tank 21, and the Ti basket 32 Metal Zn grains, metal Zn
A plate or a metal Zn ingot 34 or the like may be filled so as to eliminate metal Zn that is not immersed in the plating solution and eliminate undissolved metal Zn.
【００３１】このような構成の金属Ｚｎ溶解装置を図７
のＺｎ−Ｎｉ系合金電気メッキ設備の金属Ｚｎ溶解装置
として用いることにより、Ｚｎ−Ｎｉ系合金電気メッキ
浴へのＺｎイオンの供給を行うことができる。FIG. 7 shows a metal Zn melting apparatus having such a configuration.
By using the apparatus as a metal Zn dissolving device of the Zn-Ni-based alloy electroplating equipment, Zn ions can be supplied to the Zn-Ni-based alloy electroplating bath.
【００３２】[0032]
【実施例】図８の金属Ｚｎ溶解装置を図７のＺｎ−Ｎｉ
系合金電気メッキ設備の金属Ｚｎ溶解装置として用い、
メッキ液循環タンクにて測定した濃度が下記に示す濃度
で、温度が６０℃であるメッキ液を、図８の金属Ｚｎ溶
解槽に２ｍ3 /minの流量で流通し、溶解槽メッキ液中に
幾何面積で約１０ｍ2 の金属Ｚｎを浸漬し、Ｚｎ／対極
間にＺｎをアノードとして１０Ａの電流を流した。この
場合、図４と同様の装置で金属Ｚｎ表面上の電位を測定
したところ、平均的に約−０．１Ｖ（対ＮＨＥ）であっ
た。また、図８の装置においては、金属Ｚｎと対極の距
離は、約１０cm程度であり、対極と対面する金属Ｚｎ表
面上のメッキ液の流速は、金属Ｚｎ／対極間のバルク流
速に近似することが可能であり、この流速は平均的に１
m/minであった。また、溶解槽出側での硫酸濃度は１５g
/l であった。 FIG. 8 shows a Zn-Ni dissolving apparatus shown in FIG.
Used as a metal Zn melting device for electroplating equipment
A plating solution having a concentration measured at a plating solution circulation tank shown below and having a temperature of 60 ° C. was passed through the metal Zn dissolving tank shown in FIG. 8 at a flow rate of 2 m 3 / min. About 10 m 2 of metallic Zn was immersed in a geometric area, and a current of 10 A was passed between Zn and the counter electrode with Zn as an anode. In this case, when the potential on the metal Zn surface was measured by the same device as in FIG. 4, it was about -0.1 V (vs. NHE) on average. In the apparatus shown in FIG. 8, the distance between the metal Zn and the counter electrode is about 10 cm, and the flow rate of the plating solution on the metal Zn surface facing the counter electrode is close to the bulk flow rate between the metal Zn and the counter electrode. At an average flow rate of 1
m / min. The sulfuric acid concentration at the outlet of the dissolution tank was 15 g.
/ l.
【００３３】図１０に溶解開始からの溶解速度の経時変
化を示す。溶解速度は、溶解槽入側、出側それぞれのＺ
ｎ濃度を測定して求めた。なお、図１０では、比較とし
て、液流量が小流量（流速実測値で０．３m/min ）の場
合（）と低硫酸濃度（溶解槽出側で測定して７g/l ）
の場合（）および通電なしの場合（）も合わせて表
示している。FIG. 10 shows the change over time in the dissolution rate from the start of dissolution. The dissolution rate is determined by Z
The n concentration was determined by measurement. In FIG. 10, for comparison, the case where the liquid flow rate is a small flow rate (actually measured flow rate: 0.3 m / min) () and the low sulfuric acid concentration (7 g / l measured at the dissolution tank outlet side)
() And () without power supply are also shown.
【００３４】本発明に基づく溶解方法（実施例）によ
れば、初期の高い溶解速度を維持することが可能であ
る。更にこの場合、溶解槽出側でメッキ液を採取し、液
中のＮｉスラッジの観察を行ったが、スラッジは検出さ
れなかった。比較例（図１０中の，，）では、経
時とともに著しく溶解速度が減少し、また溶解槽出側で
は、金属Ｎｉスラッジが１０〜１０００ppm 程度検出さ
れた。According to the dissolution method (Example) according to the present invention, it is possible to maintain an initial high dissolution rate. Further, in this case, a plating solution was collected on the exit side of the melting tank, and Ni sludge in the solution was observed, but no sludge was detected. In the comparative example (, in FIG. 10), the dissolution rate was remarkably reduced with time, and about 10 to 1000 ppm of metallic Ni sludge was detected on the exit side of the dissolution tank.
【００３５】[0035]
【発明の効果】本発明によれば、Ｎｉを置換析出させる
ことなく金属Ｚｎの溶解が可能であり、Ｎｉ原単位の悪
化や押しキズ発生等の品質不良を引き起こすことなし
に、硫酸浴Ｚｎ−Ｎｉ系合金電気メッキ浴中に金属Ｚｎ
を溶解させてＺｎイオンを補充することが可能となる。
この場合に必要な設備は既に述べたように、隔膜等の複
雑なものは不要であり、極めてシンプルでコスト的にも
有利なものである。According to the present invention, it is possible to dissolve metallic Zn without substituting and precipitating Ni, and it is possible to dissolve the sulfuric acid bath Zn- Metal Zn in Ni-based alloy electroplating bath
Can be dissolved to replenish Zn ions.
As described above, the equipment required in this case does not require complicated equipment such as a diaphragm, and is extremely simple and advantageous in cost.
【図１】Ｚｎの電位ｐＨ図。FIG. 1 is a potential pH diagram of Zn.
【図２】Ｎｉの電位ｐＨ図。FIG. 2 is a potential pH diagram of Ni.
【図３】Ｚｎ溶解速度の経時変化の図である。FIG. 3 is a diagram showing the change over time of the Zn dissolution rate.
【図４】本発明に関わる溶解装置の図である。FIG. 4 is a diagram of a melting apparatus according to the present invention.
【図５】本発明に関わる析出Ｎｉ量の変化の図である。FIG. 5 is a diagram showing a change in the amount of precipitated Ni according to the present invention.
【図６】本発明に関わるＮｉ析出がなくなる電位の図で
ある。FIG. 6 is a diagram of a potential at which Ni precipitation according to the present invention is eliminated.
【図７】本発明に関わる溶解設備の図である。FIG. 7 is a diagram of a melting facility according to the present invention.
【図８】本発明に関わる溶解設備の詳細図である。FIG. 8 is a detailed view of a melting facility according to the present invention.
【図９】本発明に関わる溶解設備の詳細図である。FIG. 9 is a detailed view of a melting facility according to the present invention.
【図１０】本発明に関わるＺｎ溶解速度の経時変化の図
である。FIG. 10 is a diagram showing the change over time of the Zn dissolution rate according to the present invention.
１ 金属Ｚｎ溶解槽 ２ メッキ液 ３ 金属Ｚｎ板 ４ 対極 ５ 塩橋 ６ 参照極 ７ 電位差計 ８ 電源 ９ メッキセル １０ ストリップ １１ 金属Ｚｎ溶解槽 １２ メッキ液循
環タンク １３ メッキ液循環ポンプ １４ 流量調整バ
ルブ ２１ 溶解槽 ２２ 隔壁 ２３ 金属Ｚｎ板積層体 ２４ 通電棒 ２５ 導電性支持棒 ２６ メッキ液供
給口 ２７ 対極 ２８ 電気絶縁物 ２９ 対極支持板 ３１ メッキ液排
出口 ３２ Ｔｉバスケット ３３ フランジ ３４ 金属Ｚｎ粒DESCRIPTION OF SYMBOLS 1 Metal Zn dissolution tank 2 Plating solution 3 Metal Zn plate 4 Counter electrode 5 Salt bridge 6 Reference electrode 7 Potentiometer 8 Power supply 9 Plating cell 10 Strip 11 Metal Zn dissolution tank 12 Plating solution circulation tank 13 Plating solution circulation pump 14 Flow control valve 21 Dissolution Tank 22 Partition wall 23 Metal Zn plate laminate 24 Conducting rod 25 Conductive support rod 26 Plating solution supply port 27 Counter electrode 28 Electrical insulator 29 Counter electrode support plate 31 Plating solution discharge port 32 Ti basket 33 Flange 34 Metal Zn particles
───────────────────────────────────────────────────── フロントページの続き (72)発明者 北池 宏至 兵庫県姫路市広畑区富士町１番地 新日本 製鐵株式会社広畑製鐵所内 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Kitaike 1 Nippon Steel Corporation Hirohata Works, Himeji City, Hyogo Prefecture
Claims (11)
によるＺｎ−Ｎｉ系合金電気メッキ装置のメッキ浴槽か
らの循環メッキ液を金属Ｚｎの溶解槽に通し、メッキ液
中に金属Ｚｎを溶解させてＺｎイオンを供給する方法に
おいて、金属Ｚｎ表面上の電位（対ＮＨＥ）を下記第
式の範囲内にすることを特徴とするＺｎ−Ｎｉ系合金電
気メッキ浴へのＺｎイオンの供給方法。 −０．３１４＋０．０４５×（ｐＨ）＜金属Ｚｎ表面上の電位＜−０．０５９ ×（ｐＨ） ・・・1. A circulating plating solution from a plating bath of a Zn—Ni-based alloy electroplating apparatus using a sulfuric acid bath having a pH of 4 or less using an insoluble anode is passed through a metal Zn dissolution tank to dissolve the metal Zn in the plating solution. A method of supplying Zn ions to a Zn—Ni-based alloy electroplating bath, wherein the potential (on NHE) on the metal Zn surface is set within the range of the following formula. −0.314 + 0.045 × (pH) <potential on metal Zn surface <−0.059 × (pH)
け、金属Ｚｎと対極間に電圧を印加し、参照極によって
対極と対面する金属Ｚｎ表面上の電位を測定し、金属Ｚ
ｎと対極間の電圧を操作して、対極と対面する金属Ｚｎ
表面上の電位（対ＮＨＥ）を第式の範囲内にすること
を特徴とする請求項１に記載のＺｎ−Ｎｉ系合金電気め
っき浴へのＺｎイオンの供給方法。2. A counter electrode and a reference electrode are provided in a melting tank for metal Zn, a voltage is applied between the metal Zn and the counter electrode, and a potential on the metal Zn surface facing the counter electrode by the reference electrode is measured.
By manipulating the voltage between n and the counter electrode, the metal Zn facing the counter electrode
The method for supplying Zn ions to a Zn-Ni-based alloy electroplating bath according to claim 1, wherein the potential on the surface (vs. NHE) is within the range of the following equation.
ｎをアノードとして金属Ｚｎ、対極間に０．００１〜
０．２A/dm2 の微弱電流を流すと共に、対極と対面する
金属Ｚｎ表面上を流通するメッキ液の硫酸濃度を１０g/
l 以上とし、そのメッキ液の流速を０．５m/min 以上に
することにより、対極と対面する金属Ｚｎ表面上の電位
（対ＮＨＥ）を第式の範囲内にすることを特徴とする
請求項１に記載のＺｎ−Ｎｉ系合金電気めっき浴へのＺ
ｎイオンの供給方法。3. A counter electrode is provided in a melting tank for metal Zn,
n as the anode, metal Zn, and between 0.001 and
A weak current of 0.2 A / dm 2 was passed, and the sulfuric acid concentration of the plating solution flowing on the metal Zn surface facing the counter electrode was 10 g / dm 2.
The potential on the surface of the metal Zn facing the counter electrode (vs. NHE) is set within the range of the following equation by setting the flow rate of the plating solution to 0.5 m / min or more. Z to the Zn-Ni-based alloy electroplating bath described in 1
How to supply n ions.
面が金属Ｚｎ板の積層体の積層板厚面であることを特徴
とする請求項２または３に記載のＺｎ−Ｎｉ系合金電気
めっき浴へのＺｎイオンの供給方法。4. The Zn—Ni-based alloy electroplating according to claim 2, wherein the surface of the metal Zn facing the counter electrode in the plating solution is a thick plate of the laminate of the metal Zn plates. How to supply Zn ions to the bath.
Ｔｉバスケット内に充填された金属Ｚｎ粒、金属Ｚｎ
板、金属Ｚｎインゴット等であることを特徴とする請求
項２または３に記載のＺｎ−Ｎｉ系合金電気めっき浴へ
のＺｎイオンの供給方法。5. A metal Zn particle filled with a metal Zn facing a counter electrode in a plating solution in a Ti basket.
The method for supplying Zn ions to a Zn-Ni alloy electroplating bath according to claim 2 or 3, wherein the method is a plate, a metal Zn ingot, or the like.
によるＺｎ−Ｎｉ系合金電気メッキ装置のメッキ浴槽か
らの循環メッキ液を金属Ｚｎの溶解槽に通し、メッキ液
中に金属Ｚｎを溶解させてＺｎイオンを供給する装置に
おいて、上記溶解槽のメッキ液中に金属Ｚｎ板の積層体
を浸漬保持すると共に、上記金属Ｚｎ板積層体の積層板
厚面と対面するように対極をメッキ液中に浸漬保持し、
対極と金属Ｚｎ板積層体の積層板厚面との間をメッキ液
が流れるように溶解槽にメッキ液供給口および排出口を
設け、金属Ｚｎ板積層体を陽極、対極を陰極とする電源
を設けたことを特徴とするＺｎ−Ｎｉ系合金電気メッキ
浴へのＺｎイオンの供給装置。6. A circulating plating solution from a plating bath of a Zn—Ni-based alloy electroplating apparatus using a sulfuric acid bath having a pH of 4 or less using an insoluble anode is passed through a metal Zn dissolution tank to dissolve the metal Zn in the plating solution. In a device for supplying Zn ions, the laminate of metal Zn plates is immersed and held in the plating solution of the dissolving tank, and the counter electrode is placed in the plating solution so as to face the thick plate of the metal Zn plate laminate. Immersed in
A plating solution supply port and a discharge port are provided in the dissolution tank so that the plating solution flows between the counter electrode and the laminated plate thick surface of the metal Zn plate laminate, and a power supply having the metal Zn plate laminate as an anode and the counter electrode as a cathode is provided. An apparatus for supplying Zn ions to a Zn-Ni-based alloy electroplating bath, wherein the apparatus is provided.
によるＺｎ−Ｎｉ系合金電気メッキ装置のメッキ浴槽か
らの循環メッキ液を金属Ｚｎの溶解槽に通し、メッキ液
中に金属Ｚｎを溶解させてＺｎイオンを供給する装置に
おいて、上記溶解槽のメッキ液中に浸漬保持したＴｉバ
スケット内に、金属Ｚｎ粒、金属Ｚｎ板、金属Ｚｎイン
ゴット等を充填し、Ｔｉバスケットと対面するように対
極をメッキ液中に浸漬保持し、対極とＴｉバスケットの
間をメッキ液が流れるように溶解槽にメッキ液供給口お
よび排出口を設け、上記Ｔｉバスケットを介して上記金
属Ｚｎを陽極、対極を陰極とする電源を設けたことを特
徴とするＺｎ−Ｎｉ系合金電気メッキ浴へのＺｎイオン
の供給装置。7. A circulating plating solution from a plating bath of a Zn—Ni-based alloy electroplating apparatus using a sulfuric acid bath having a pH of 4 or less using an insoluble anode is passed through a metal Zn dissolution tank to dissolve the metal Zn in the plating solution. In a device for supplying Zn ions, a Ti basket immersed and held in a plating solution of the dissolving tank is filled with metal Zn particles, a metal Zn plate, a metal Zn ingot, and the like, and a counter electrode is provided so as to face the Ti basket. A plating solution supply port and a discharge port are provided in the dissolving tank so that the plating solution flows between the counter electrode and the Ti basket while being immersed and held in the plating solution. The metal Zn is an anode through the Ti basket, and the counter electrode is a cathode. A supply device for supplying Zn ions to a Zn-Ni-based alloy electroplating bath, comprising a power supply for performing the above-mentioned operations.
この孔に通電棒を挿入し、溶解槽のメッキ液面の上方に
配置した２本の通電用支持棒で上記通電棒の両端部を支
えることで金属Ｚｎ板の積層体の下部をメッキ液中に浸
漬保持し、対極の上端部に設けた対極支持板の両端部を
電気絶縁物を介して上記２本の導電性支持棒にて支える
ことで対極の下部を、メッキ液中の金属Ｚｎ板積層体下
部の積層板厚面に対向して、メッキ液中に浸漬保持する
と共に、支持棒、通電棒を介して金属Ｚｎ板積層体を陽
極、対極支持板を介して対極を陰極とするように電源に
接続したことを特徴とする請求項６に記載のＺｎ−Ｎｉ
系合金電気メッキ浴へのＺｎイオンの供給装置。8. A metal Zn plate is laminated and a hole is formed in an upper part,
A current-carrying rod is inserted into this hole, and two ends of the current-carrying rod are supported by two current-carrying support rods disposed above the plating solution level of the dissolving tank, so that the lower part of the metal Zn plate laminate is placed in the plating solution. The lower end of the counter electrode is supported by the two conductive support rods via an electrical insulator, and the lower part of the counter electrode is supported by the metal Zn plate in the plating solution. Opposite to the thick surface of the laminate at the bottom of the laminate, while being immersed and held in the plating solution, the support rod, the metal Zn plate laminate through a current-carrying rod as an anode, and the counter electrode as a cathode through a counter electrode support plate. The Zn-Ni according to claim 6, wherein the Zn—Ni is connected to a power supply.
Equipment for supplying Zn ions to a system alloy electroplating bath.
け、溶解槽のメッキ液面の上方に配置した２本の通電用
支持棒で上記フランジを支えることでＴｉバスケットの
下部をメッキ液中に浸漬保持すると共に、上記Ｔｉバス
ケットに、金属Ｚｎ粒、金属Ｚｎ板、金属Ｚｎインゴッ
ト等を充填し、対極の上端部に設けた対極支持板の両端
部を電気絶縁物を介して上記２本の導電性支持棒にて支
えることで対極の下部を、Ｔｉバスケットに対向して、
メッキ液中に浸漬保持すると共に、支持棒、フランジ、
Ｔｉバスケットを介して金属Ｚｎを陽極、対極支持板を
介して対極を陰極とするように電源に接続したことを特
徴とする請求項７に記載のＺｎ−Ｎｉ系合金電気メッキ
浴へのＺｎイオンの供給装置。9. A flange is provided on an upper portion of a Ti basket, and the lower portion of the Ti basket is immersed and held in a plating solution by supporting the flange with two current-carrying support rods disposed above a plating solution level of a melting tank. At the same time, the Ti basket is filled with metal Zn grains, a metal Zn plate, a metal Zn ingot, and the like, and both ends of the counter electrode support plate provided at the upper end of the counter electrode are electrically connected to each other through an electrical insulator. By supporting with a support rod, the lower part of the counter electrode faces the Ti basket,
While immersing and holding in the plating solution, support rods, flanges,
The Zn ion to the Zn-Ni alloy electroplating bath according to claim 7, wherein the Zn-Ni alloy electroplating bath is connected to a power source such that the metal Zn is an anode via a Ti basket and the counter electrode is a cathode via a counter electrode support plate. Feeder.
が間隔を存してそれらの下部が浸漬保持され、対極の間
に金属Ｚｎ板積層体の下部が、浸漬保持されることを特
徴とする請求項６または８に記載のＺｎ−Ｎｉ系合金電
気メッキ浴へのＺｎイオンの供給装置。10. A method in which a plurality of counter electrodes are immersed and held at intervals in a plating solution in a melting tank, and a lower portion of a metal Zn plate laminate is immersed and held between the counter electrodes. The apparatus for supplying Zn ions to a Zn-Ni-based alloy electroplating bath according to claim 6 or 8, wherein:
が間隔を存してそれらの下部が浸漬保持され、対極の間
にＴｉバスケットの下部が浸漬保持され、このバスケッ
ト内に金属Ｚｎ粒、金属Ｚｎ板、金属Ｚｎインゴット等
が充填されることを特徴とする請求項７または９に記載
のＺｎ−Ｎｉ系合金電気めっき浴へのＺｎイオンの供給
装置。11. A lower portion of a plurality of counter electrodes is immersed and held in a plating solution in a melting tank at intervals, and a lower portion of a Ti basket is immersed and held between the counter electrodes. The apparatus for supplying Zn ions to a Zn-Ni-based alloy electroplating bath according to claim 7 or 9, wherein the apparatus is filled with grains, a metal Zn plate, a metal Zn ingot, or the like.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09885197A JP3370896B2 (en) | 1997-04-16 | 1997-04-16 | Method and apparatus for supplying Zn ions to a Zn-Ni alloy electroplating bath |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09885197A JP3370896B2 (en) | 1997-04-16 | 1997-04-16 | Method and apparatus for supplying Zn ions to a Zn-Ni alloy electroplating bath |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10287999A true JPH10287999A (en) | 1998-10-27 |
| JP3370896B2 JP3370896B2 (en) | 2003-01-27 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP09885197A Expired - Fee Related JP3370896B2 (en) | 1997-04-16 | 1997-04-16 | Method and apparatus for supplying Zn ions to a Zn-Ni alloy electroplating bath |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3370896B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100403463B1 (en) * | 1998-12-08 | 2004-01-28 | 주식회사 포스코 | Manufacturing method of nickel flash-plated steel sheet to attach nickel uniformly and finely over the whole steel plate |
| KR101287439B1 (en) * | 2012-10-15 | 2013-07-19 | (주) 거양 | Zinc plate for anode electrode of plating equipment having sulfuric acid |
-
1997
- 1997-04-16 JP JP09885197A patent/JP3370896B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100403463B1 (en) * | 1998-12-08 | 2004-01-28 | 주식회사 포스코 | Manufacturing method of nickel flash-plated steel sheet to attach nickel uniformly and finely over the whole steel plate |
| KR101287439B1 (en) * | 2012-10-15 | 2013-07-19 | (주) 거양 | Zinc plate for anode electrode of plating equipment having sulfuric acid |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3370896B2 (en) | 2003-01-27 |
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