JP2004325201A - Electrode potential measuring probe and continuous electrolyzation apparatus of metal foil with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode potential measuring probe for regularly monitoring a surface state of an electrode used for continuous electrolyzation and also monitoring product quality. <P>SOLUTION: The electrode potential measuring probe captures a potential change of the electrode during electrolyzation by bring the electrode into contact with either a cathode or an anode outwardly protruding from a solution when an electrolytic method is implemented, and is employed and provided with a casing with an opening at one end and a reference electrode fixing part and a solution inflow hole at the other end, a reference electrode having a potential measuring liquid junction on a primary side and a terminal connected to a potentiometer on a secondary side and inserted into the casing, and a water absorbing flexible material disposed at the opening and constituting a contact part with the electrode surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
[Industrial applications]
The present invention relates to a probe for measuring an electrode potential. In particular, it is used for electrode potential measurement for controlling the surface state of the electrode material when performing a plating process and continuous electrolysis of a metal foil such as an electrolytic copper foil.
[0002]
[Prior art]
Conventionally, metal plating generally employs a method in which an object to be plated is polarized into a cathode in an electrolytic solution and a plating film is formed on the surface thereof. In the continuous production of a metal foil represented by an electrolytic copper foil, a method has been adopted in which a copper component is deposited on the surface of a cathode-polarized drum-shaped rotating cathode, and the resultant is foil-shaped and continuously peeled off.
[0003]
In the electrolytic operation for the purpose of industrial mass production such as the metal plating process and the continuous production of metal foil, only the current is controlled, and the control based on the potential difference is hardly performed. Therefore, only the current value is disclosed in the contents disclosed in Patent Literature 1 and Patent Literature 2 described below, and no description is made regarding the potential difference.
[0004]
[Patent Document 1]
JP-A-5-279896 [Patent Document 2]
JP-A-7-202367
On the other hand, it has been almost impossible to measure a potential difference of a solution by placing a reference electrode in an electrolytic cell in a continuous production process of plating or metal foil employing an electrolytic method. That is, when the energization operation is performed in a region where oxygen generation from the anode is active, bubbling due to generated oxygen occurs, and the reference electrode is affected by the flow of the circulating solution into the plating tank, which is different from the actual substance. The phenomenon that the potential difference is measured and that the measured potential difference is not stable occurs. Therefore, applying the technical idea disclosed in Patent Document 3, the solution used for electrolysis is temporarily retained in an external chamber, and the potential difference of the solution is measured there, thereby stabilizing the electrolytic operation. It is also possible to plan.
[0006]
From a metallurgical point of view, in order to strictly control the amount of plating metal deposited, the physical properties of the metal foil obtained by electrolysis, etc., consider the electrode material used during electrolysis, the solution concentration, the solution pH, etc. It is considered common knowledge among those skilled in the art that it is desirable to measure the Tafel slope of the polarization curve and control the deposition state with a potential difference. In particular, a quick response is required for a component change such as a solution concentration. Therefore, it can be said that the potential difference management of the solution is very important.
[0007]
[Patent Document 3]
Japanese Patent Application Laid-Open No. 10-282036
[Problems to be solved by the invention]
However, when the plating metal is deposited and the metal foil is continuously manufactured using the electrolysis method, the surface state of the electrode may be oxidized or hydride may be formed with the lapse of time used for the electrolysis. Then, a phenomenon occurs in which the surface roughness changes due to erosion by the electrolytic solution.
[0009]
As described above, if the state of the electrode surface changes, no matter how well the solution temperature, concentration, etc. of the electrolytic solution are controlled, it is necessary to obtain a uniform plating film or to produce a metal foil having good physical properties. It will be difficult.
[0010]
From the above, those skilled in the art have demanded a management device and a management method that can constantly grasp the state of the electrode surface used for electrolysis and can stabilize product quality.
[0011]
[Means for Solving the Problems]
Therefore, the inventors of the present invention have conducted intensive studies and found that it is possible to measure the potential difference between the electrodes by using an electrode potential measuring probe having the following configuration.
[0012]
<Electrode potential measurement probe> The electrode potential measurement probe according to the present invention is used during electrolysis by contacting either a cathode or an anode protruding out of a solution when a metal component is deposited on an electrode by an electrolysis method. An electrode potential measurement probe for detecting a change in potential difference, the electrode potential measurement probe having a casing having an open end at one end and a reference electrode fixing portion and a solution inflow hole at the other end, and a potential measurement at a primary side. A reference electrode that can be inserted into the casing, and a water-absorbing soft material that is disposed at the open end and constitutes a contact portion to the electrode. It consists of: Hereinafter, description will be made with reference to FIG.
[0013]
Here, "the electrode potential measurement probe for capturing the change in potential difference during electrolysis by contacting either the cathode or the anode protruding out of the solution when the metal component is deposited on the electrode by electrolysis, Therefore, the probe for measuring the electrode potential according to the present invention is disposed in the electrolytic solution and does not measure the electrode potential, but either the cathode or the anode protruding out of the solution without the influence of bubbling or the like. It is used so as to contact a part of the
[0014]
First, the “casing” constituting the electrode potential will be described. This casing has an open end at one end and a reference electrode fixing portion and a solution inflow hole at the other end. That is, this casing means the main body of the probe for measuring the electrode potential, and when used as the probe for measuring the electrode potential, the solution is introduced into the inside through the solution inflow hole and temporarily stored. It is. The shape of the casing itself is arbitrary as long as the casing fulfills the following functions.
[0015]
The material of the casing is a metal material, a plastic material, or the like, and is not particularly limited. The material can be changed according to the type of the solution stored inside. For example, when a hydrofluoric acid-based solution is partially contained, a plastic-based material is used. However, in order to quickly detect an abnormality such as whether the solution in the casing has crystallized, it is preferable to use a transparent material such as glass or plastic from which the inside can be observed from the outside.
[0016]
Then, a water-absorbing soft material is disposed at an opening end on one end side of the casing to make a contact portion with the electrode surface. The diameter of the open end may be appropriately determined in consideration of the outflow amount of the solution, and does not need to be particularly limited. In addition, the soft water-absorbing material mentioned here must be capable of maintaining the amount of the solution flowing out within an appropriate range, not causing deterioration due to the solution, and not damaging the electrode surface. There is no particular limitation on the material as long as such conditions are satisfied. For example, a sponge material made of a plastic material, a paper material used for filter paper, and the like can be used.
[0017]
Next, as is generally known, the reference electrode is provided with a liquid junction portion on the primary side and a connection terminal portion for connecting to a potentiometer on the secondary side. The reference electrode referred to here is not particularly limited in type, and is described as a concept that can be used for all reference electrodes such as a conventional calomel electrode, a mercuric sulfate first electrode, and a silver chloride electrode. The reference electrode is fixedly disposed on the reference electrode fixing portion of the casing so that at least the primary liquid junction portion is inserted into the casing so as to be immersed in the liquid storage. There is no particular limitation on the fixing method at this time, as long as the reference electrode can be arranged in the above-described state. However, a metal material can be used for the fixing means, but it is preferable to use a material such as rubber or plastic that can prevent corrosion by a solution.
[0018]
As described above, the electrolytic solution is introduced into the casing through the solution inlet so that the liquid junction portion of the reference electrode is immersed in the liquid stored in the casing, and temporarily stored, and the liquid is stored from the contact portion. It becomes a probe for measuring the electrode potential that flows out slowly. By flowing the liquid from the contact portion in this way, the solution can be circulated and the electrode potential can be measured with a small time lag, and in the case of a movable electrode such as an electrolytic drum used for producing an electrolytic copper foil, the electrode surface can be measured. This provides a lubricating effect that reduces the coefficient of friction between the electrodes and prevents damage to the electrode surface.
[0019]
Furthermore, when the temperature of the electrolytic solution introduced into the casing and temporarily stored therein is high and the concentration is high, recrystallization may be caused due to a decrease in the solution temperature in the casing. Therefore, it is preferable to provide means for keeping the liquid stored so that the temperature of the liquid stored inside the casing does not decrease. As the heat retaining means, as a means for preventing the liquid temperature of the stored liquid from being lowered as a result, it is possible to provide a means for keeping the temperature of the casing itself or a means for heating the stored liquid. For example, the periphery of the casing is covered with a heat insulating material, a heating element is arranged around the casing, and a heating element is built in the casing.
[0020]
It is described that a "solution" is simply introduced into the casing of the electrode potential measuring probe described above. This means that it is not always necessary to use the electrolytic solution itself used for electrolysis. This is because the electrode potential measuring probe according to the present invention does not measure the potential difference of the electrolytic solution itself, but measures the potential of the electrode in order to detect a change in the electrode itself. Therefore, as described above, it is not necessary to forcibly introduce a solution having a high concentration and a high solution temperature, and use a dilute solution having a concentration that does not cause recrystallization because the same kind of contained substance is used in the electrolytic solution. , It can be considered as a change in electrode potential. If the way of variation at this time and the correspondence between the product quality obtained in response thereto are empirically grasped, the potential difference obtained by the electrode potential measurement probe according to the present invention can be sufficiently determined by the product quality control index. It can be used as
[0021]
<Continuous Electrolysis Apparatus for Metal Foil Provided with Probe for Measuring Electrode Potential According to the Present Invention> The above-described probe for measuring electrode potential is most likely to be applied to a metal foil continuous electrolysis apparatus because of its usage. This is considered to be an excellent use form.
[0022]
In general, a continuous electrolysis apparatus for a metal foil typified by an electrolytic copper foil will be briefly described here. As shown in FIG. 2, the basic structure of the continuous production apparatus for metal foil is that a rotating cathode 11 in the form of a drum and a lead-based or insoluble anode 12 disposed opposite to the rotating cathode 11 according to the shape of the rotating cathode 11. Then, a solution containing metal ions is caused to flow, and a metal component is deposited on the drum surface of the rotating cathode 11 by utilizing an electrolytic reaction. Then, the metal deposited at this time becomes a foil state, and is continuously peeled off from the rotating cathode 11 via the peeling roll 13 and wound up to form the metal foil roll 14. At this time, the surface of the copper foil peeled off from the rotating cathode 11 is referred to as a glossy surface, and the opposite matte surface is referred to as a rough surface.
[0023]
At this time, in the state described as an example in FIG. 2, the contact surface where the water-absorbing soft material of the electrode potential measuring probe 1 is arranged is pressed against the surface of the rotating cathode 11 to damage the electrode surface. Instead, the electrode potential difference at the cathode can be measured in real time, and the surface state of the cathode and the stable state of the electrolytic state can be constantly monitored.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described. In this embodiment, in the same manner as shown in FIG. 2, the electrode potential measuring probe 1 is fixed and installed in the apparatus for manufacturing an electrodeposited copper foil with the clamp 15, and the result of continuously measuring the electrode potential difference is shown. It will be shown.
[0025]
First, a detailed configuration of the electrode potential measuring probe 1 used in this embodiment will be described. The casing 2 of the electrode potential measuring probe 1 is made of a plastic transparent material having an inner diameter of 13 mm, a length of 100 mm, and a tapered shape toward the open end 3 having an open end 3 at one end having an inner diameter of 7 mm. And a solution inlet hole 5 having an inner diameter of 4 mm was used. As the water-absorbing soft material disposed at the opening end 3 on one end side of the casing 2, paper of a material used as a filter paper was processed into a shape as shown in FIG. On the other hand, as the reference electrode 8, a cylindrical SCE electrode having an outer diameter of 10.5 mm as shown in FIG. 1 is used, and the reference electrode 8 is a rubber ring as the reference electrode fixing portion 4. It was arranged in a state of being penetrated, and the rubber ring was fitted and fixed to the other end side of the casing 2 as shown in FIG.
[0026]
As described above, the solution obtained by diluting the copper sulfate solution used for the production of the electrolytic copper foil to a half concentration from the solution tank 16 through the flow path 17 through the solution inflow hole 5 of the casing 2 at a flow rate of 1 ml / min. So that the liquid junction 9 of the reference electrode 8 is immersed in the liquid storage 6 ′ in the casing 2, and the liquid storage 6 ′ flows out of the contact portion C gently according to the inflow amount. I did it.
[0027]
Then, the connection terminal portion 10 of the reference electrode 8 is connected to a potentiometer 18 to detect the potential difference and to always output the potential difference to a recorder 19. Hereinafter, the result of the measurement of the electrode potential in this embodiment will be described. In addition, titanium was used for the electrodeposited surface of the rotating cathode 11 used for manufacturing the electrolytic copper foil, and an insoluble anode (DSA) was used for the anode 12.
[0028]
Relationship between Electrode Potential Difference and Polishing In the production site of electrolytic copper foil, when the roughness of the peeled surface of the produced electrolytic copper foil with the rotating cathode becomes large, it is usual to buff the electrodeposited surface of the rotating cathode 11. Is being done. Accordingly, FIG. 3 shows a comparison between (1) the electrode potential difference at the time when buffing is required and (2) the electrode potential difference after buffing. As can be seen from FIG. 3, it can be clearly understood that the potential difference of (1) becomes very large and the potential difference of (2) becomes small. Therefore, if the relationship between the change in the potential difference and the surface roughness of the obtained electrolytic copper foil is grasped, the timing for polishing with this electrode potential difference can be determined without measuring the surface roughness of the obtained electrolytic copper foil. You can decide.
[0029]
Time-dependent change in electrode potential difference after buffing Although the electrode potential difference immediately after buffing is small, it is empirical that if the potential difference is small, it cannot be said that electrolytic copper foil with good quality can be obtained. It is known. Conventionally, this problem has been abandoned, but the use of the electrode potential measuring probe according to the present invention makes it possible to grasp the changing state of the electrode potential difference, and it has been found new.
[0030]
FIG. 4 shows a temporal change of the electrode potential difference when the production of the electrolytic copper foil is performed continuously immediately after the buffing. According to this result, when the electrolysis is continued immediately after the buffing, the potential difference that was initially high gradually decreases, and the value of the potential difference becomes stable after 4 hours.
[0031]
Therefore, the present inventors measure the physical properties of the electrolytic copper foil obtained with the passage of time, such as the roughness of the glossy surface and the rough surface, the tensile strength and the elongation in the normal state, and the measurement in a 180 ° C. heating atmosphere. The properties of hot tensile strength and elongation were measured. As a result, none of the physical properties was stabilized until the continuous electrolysis time passed 4 hours, and the value of the electrode potential difference detected by the electrode potential measurement probe according to the present invention was stabilized after 4 hours passed. At the same time, it was found that the values of each physical property also became stable.
[0032]
In addition, the number of generated microporosity found in the electrolytic copper foil, the tendency that the number of generated microporosity also increased as the value of the electrode potential difference detected by the electrode potential measuring probe according to the present invention increased was remarkably confirmed. It is.
[0033]
Therefore, the value of the electrode potential difference detected by the electrode potential measuring probe according to the present invention is very reliable, and a change in this value is used as a monitor for the change in the physical properties of the electrolytic copper foil and the occurrence of microporosity. It turns out that things are possible.
[0034]
【The invention's effect】
As described above, the electrode potential measuring probe according to the present invention according to the present invention is very simple and does not require much cost to produce. This makes it possible to continuously measure the electrode potential difference. In this way, it is possible to constantly monitor the electrode potential, detect the deterioration of the electrode itself, and perform post-mortem inspection of the physical properties of the metal foil or plating film formed on the electrode surface with the potential difference. Instead, it is possible to make analogies.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a probe for measuring an electrode potential according to the present invention.
FIG. 2 is a view showing an image in which the electrode potential measuring probe according to the present invention is attached to a continuous apparatus for manufacturing a metal foil.
FIG. 3 is a diagram showing a relationship between an electrode potential difference and polishing.
FIG. 4 is a diagram showing a change with time of an electrode potential difference after buffing.
[Explanation of symbols]
Reference Signs List 1 electrode potential measurement probe 2 casing 3 open end 4 reference electrode fixing part 5 solution inflow hole 6 solution 7 water-absorbing soft material 8 reference electrode 9 liquid junction part 10 connection terminal part 11 rotating cathode 12 anode 13 stripping roll 14 metal foil Roll 15 Clamp 16 Solution tank 17 Flow path 18 Potentiometer 19 Recorder C Contact area S Electrode surface

Claims (3)

An electrode potential measurement probe for capturing a change in potential difference of the electrode during electrolysis by contacting either the cathode or the anode protruding out of the solution when the metal component is deposited on the electrode by the electrolytic method,
The electrode potential measurement probe has a casing having an open end at one end and a reference electrode fixing portion and a solution inflow hole at the other end, and a primary side connected to a liquid junction for potential measurement and a secondary side connected to a potentiometer. A reference electrode that is a terminal part and can be inserted into the casing, and is made of a water-absorbing soft material disposed at the open end to constitute a contact part to the electrode surface,
A water-absorbing soft material is arranged at an opening end on one end side of the casing to be a contact portion with the electrode surface, and inserted into the casing from the liquid junction portion on the primary side of the reference electrode from the other end side, Is arranged on the reference electrode fixing part so that the connection terminal part of can be connected to the potentiometer,
That the electrolyte is introduced into the casing through the solution inflow hole so that the liquid junction of the reference electrode is immersed in the liquid and temporarily stored, and the liquid is allowed to slowly flow out of the contact portion. Characteristic probe for measuring electrode potential. The probe for measuring an electrode potential according to claim 1, wherein the casing comprises a means for keeping the liquid stored. A solution containing metal ions flows between the drum-shaped rotating cathode and the anode arranged along the shape of the rotating cathode, and metal components are deposited on the drum surface of the rotating cathode using an electrolytic reaction. In the metal foil manufacturing apparatus that is to peel off the deposited metal continuously in a foil state,
An apparatus for continuously manufacturing a metal foil, wherein the electrode potential measuring probe according to claim 1 or 2 is attached to the surface of the drum exposed outside the solution of the rotating cathode.

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