JP2008106292A - Method for producing cathode for electrowinning of special shape electric nickel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which the contraction or the deformation of an electrodeposition part formed by masking using an insulating material can be prevented and the special shape of the electrodeposition part can be maintained for a cathode used for electrowinning of special shape electric nickel for plating. <P>SOLUTION: An one-component epoxy resin is used as an insulating material applied on a cathode base plate for masking, and the kinetic viscosity of the resin is kept within a range of 10,000-30,000 cSt regardless of outside air temperature when the resin is applied. Further, concretely, the one-component epoxy resin is preheated so that the temperature Y (°C) of the resin satisfies following relation: Y= -0.82X+48.28, wherein X is outside air temperature, and the resin is applied on the cathode base material within one hour immediately after preheating. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a cathode used for electrolytically collecting electroplated nickel having a special shape for plating.

  In electrolytic refining of metals such as nickel, a cathode made of a metal that is different from the metal to be collected as the cathode and that can be used repeatedly is used for electrolysis for a predetermined period of time. Generally, a method of peeling and collecting from a mother board is performed. At this time, an electrodeposit having an arbitrary special shape can be obtained by masking the base plate as a cathode with an insulator.

  For example, electronickel used as an anode for plating is often preferred to have a rounded lump shape with no corners from the viewpoints of filling properties and handling properties in the anode box during use. Therefore, when such a small lump of electronickel is produced by electrolytic purification, as described in JP-A-2002-302787, a large number of circular electrodeposition portions (portions where nickel is electrodeposited) are formed. The cathode is masked to have electrolysis.

When the surface is masked with an insulator so as to obtain a specially shaped electrodeposit as described above, a one-part epoxy resin is used as a masking agent that is an insulator, and the electrodeposition portion has a desired special shape, for example, a perfect circle Apply using a screen. At this time, the electrodeposition circle formed of the one-component epoxy resin may be distorted due to fluctuations in the resin temperature, and the electrodeposition area may be reduced or deformed to 10 to 70% of the true circle. For this reason, the shape of the electrodeposited electric nickel is also distorted and there is a problem that the appearance is deteriorated.
JP 2002-302787 A

  In view of such a conventional situation, the present invention reduces or deforms an electrodeposition portion formed by masking with an insulator when manufacturing a cathode used for electrowinning of special-shaped electronickel for plating. An object of the present invention is to provide a method capable of preventing and maintaining the special shape of the electrodeposited portion.

  In order to achieve the above object, the present invention provides an insulating material to be applied to a cathode base plate for masking in a method of manufacturing a cathode whose surface is masked with an insulating material so that electronickel having a special shape can be obtained by electrowinning. Provided is a method for producing a cathode for electrowinning of specially shaped electro nickel, which uses a liquid epoxy resin and maintains the kinematic viscosity at the time of application of the one-component epoxy resin at 10,000 to 30,000 cSt regardless of the outside temperature To do.

  In the method for producing a cathode for electrowinning specially shaped nickel according to the present invention, more specifically, when preheating the one-component epoxy resin, Y = −0.82X + 48 with respect to the outside air temperature X. It is preheated to a resin temperature Y satisfying the relationship of .27, and is applied to the cathode base plate immediately after preheating to 1 hour.

  According to the present invention, it is possible to prevent the masking electrodeposition portion formed of the one-component epoxy resin from being reduced or deformed. For example, when the electrodeposition portion is circular, the area of the electrodeposition portion is changed to the original perfect circle. On the other hand, it can be kept at 80% or more. Therefore, specially-shaped electronickel for plating having a good appearance can be stably produced by electrowinning using the cathode according to the present invention.

  In general, in the electrowinning of special-shaped electronickel for plating, the shape of electronickel is favorably rounded and rounded with no corners from the viewpoint of filling and handling in the anode box. A cathode that is masked so as to have a large number of circular electrodeposition portions on the surface of the mother board is used. As a masking method, an insulating material is applied to the surface of a base plate made of a material such as titanium (Ti) which can be used repeatedly so that the electrodeposition portion becomes a perfect circle by screen printing, and then masked by drying and curing. .

  In the present invention, a one-component epoxy resin is used as an insulator for masking. The one-part epoxy resin is not particularly limited, and one that has been conventionally used for masking a cathode for electrolytic collection of special-shaped electronickel can be used. For example, a one-component epoxy resin (trade name B-1057) manufactured by Tesque Co., Ltd. can be preferably used.

  However, since the viscosity of a one-component epoxy resin is likely to vary depending on the outside air temperature, it is difficult to perform printing and coating within an appropriate viscosity range. For this reason, the shape of the electrodeposition part formed immediately after application collapses, or the shape changes from immediately after application to drying, and a good electrodeposition part shape cannot be obtained after drying and curing. Therefore, it is extremely difficult to mask a special shape such as a perfect circle.

  Therefore, as a result of intensive studies on the kinematic viscosity of the one-part epoxy resin and the circular electrodeposition shape formed by masking, the present inventors have determined that the kinematic viscosity of the resin is less than 10,000 cSt, and the resin is applied immediately after application. As a result, it was found that the electrodeposited part of the electrode was oozed out and a good circular electrodeposited part could not be retained. Moreover, when the kinematic viscosity of resin exceeded 30000 cSt, it turned out that the shape change of an electrodeposition part occurs after application | coating until it dries and hardens | cures, and a favorable circular electrodeposition part cannot be obtained.

  On the other hand, if the kinematic viscosity of the one-part epoxy resin is controlled in the range of 10,000 to 30000 cSt, the resin does not bleed out or the shape of the electrodeposition part does not change during application or from application to drying / curing. It has been found that a circular electrodeposition portion can be formed. Based on such knowledge, in the present invention, the kinematic viscosity that fluctuates depending on the outside temperature of the one-component epoxy resin applied to the cathode base plate is always kept at 10,000 to 30,000 cSt by controlling the resin temperature. As a result, a cathode having a well-shaped electrodeposition portion can be produced.

  Next, as a result of investigating the relationship between the temperature and the kinematic viscosity of the one-component epoxy resin, the relationship between the resin temperature and the kinematic viscosity as shown in FIG. 1 was obtained. From the relationship between the temperature and kinematic viscosity of this one-part epoxy resin, in order to keep the kinematic viscosity in the range of 10,000 to 30000 cSt, the resin temperature during coating should be kept in the range of about 25 to 35 ° C. regardless of the outside temperature. I know what to do. That is, if the temperature of the one-component epoxy resin at the time of coating is controlled to about 25 to 35 ° C., the kinematic viscosity can be maintained in the range of 10,000 to 30000 cSt, and as a result, the electrodeposition portion having a good shape by machining. Can be formed.

  In addition, since the kinematic viscosity falls below 10000 cSt when the temperature at the time of application of the one-component epoxy resin exceeds 35 ° C., the resin is oozed out immediately after application, and a good circular electrodeposition is achieved. The part cannot be held. In addition, when the resin temperature at the time of application is less than 25 ° C., the kinematic viscosity is higher than 30000 cSt, so that the shape change of the electrodeposition part occurs from application to drying / curing, and a good circular electrodeposition part is obtained. I can't do that.

  As described above, in order to manage the kinematic viscosity of the one-component epoxy resin at the time of application in the range of 10,000 to 30000 cSt, the resin temperature at the time of application is always in the range of 25 to 35 ° C. regardless of the fluctuation of the outside air temperature. It is necessary to manage. It goes without saying that the method of controlling the resin temperature during coating is not uniform, and various methods can be applied. Here, in the case where the resin is preheated as a preparatory work before application, a resin temperature management method taking into consideration that the resin temperature changes due to the influence of the outside air temperature will be described.

  In general, when the resin is preheated to a constant temperature in the preparatory work, the resin is applied within a predetermined time thereafter, but the resin temperature at the time of application changes due to the influence of the outside air temperature. Therefore, when the resin temperature and the outside air temperature due to the preheating of the one-component epoxy resin are applied within 1 hour immediately after the most general preheating, the resin temperature at the time of application is in the range of 25 to 35 ° C. which is the optimum temperature. As a result of investigating the inner relationship, the relationship shown in FIG. 2 was obtained. For example, when the outside air temperature is 10 ° C., it can be seen from the graph of FIG. 2 that the resin temperature may be controlled to 40 ° C. by preheating and applied within one hour as usual.

  From the result shown in FIG. 2, as a method of applying the one-component epoxy resin after preheating, the resin temperature Y is preheated so as to satisfy the relationship of Y = −0.82X + 48.27 with respect to the outside air temperature X, and immediately after preheating. Apply to cathode base plate for ~ 1 hour. According to this method, the resin temperature is in the range of 25 to 35 ° C. during coating, and the kinematic viscosity of the resin is also in the range of 10,000 to 30000 cSt. As a result, the cathode base plate made of titanium or the like is formed with a mask having an electrodeposition portion that is not deformed, and a good cathode used for the electrowinning of special-shaped nickel can be manufactured.

  In the cathode for electrolytic collection of special-shaped electronickel, the good electrodeposition part shape is, for example, when the electrodeposition part is circular, the cathode is compared to the area of the circular part set on the printing screen. It means that the area of the formed electrodeposition part is maintained 80% or more. When the area of the electrodeposited portion is less than 80% of the area of the circular portion set on the screen, it is not possible to produce special nickel electroplating for plating having a good appearance, and the current density increases during operation. This is because problems such as generation of hydrogen gas occur.

  A one-part epoxy resin (Tesque Co., Ltd., trade name B-1057) is applied to the surface of the SUS cathode base plate by screen printing, dried and cured, and masked with a number of circular electrodeposition parts. Formed. At that time, the one-component epoxy resin was preheated to 40 ° C. and 25 ° C. in advance at an outside air temperature of 10 ° C. and applied after 45 minutes. The circular portion set on the screen is a perfect circle with a diameter of 15 mm.

  A photograph of the masking surface of the obtained cathode is shown in FIG. 3A shows the case where the resin temperature is preheated to 40 ° C., and FIG. 3B shows the case where the resin temperature is preheated to 25 ° C. In (A) preheated to 45 ° C., a clean electrodeposition portion close to a perfect circle was obtained, whereas in (B) preheated to 25 ° C., the circle was distorted and a clean electrodeposition portion was not obtained. This result shows that when the preheated resin is applied under the condition of an outside air temperature of 10 ° C., the kinematic viscosity of the resin can be kept within the range of 10,000 to 30000 cSt in (A), while it is kept in (B). Because it was not possible.

  Further, with respect to the masking surface of the obtained cathode, the diameter of each circular electrodeposition portion was measured to obtain the maximum value, the minimum value, and the average value. Furthermore, from these, the average value of the area of the electrodeposition part and the area ratio of the electrodeposition part to the perfect circle of the circular part set on the screen were obtained. These results are shown in Table 1 below. As can be seen from Table 1 below, the area ratio to the perfect circle was 92% in (A) where the resin temperature was preheated to 40 ° C., whereas it was 78% in (B) where the resin temperature was preheated to 25 ° C. .

It is a graph which shows the relationship between the resin temperature of a one-component epoxy resin, and kinematic viscosity. It is a graph which shows the relationship from which the resin temperature at the time of application | coating is in the range of 25-35 degreeC about the resin temperature Y and the external temperature X by preheating of a one-component epoxy resin. It is the photograph of the masking surface of the cathode obtained in the Example, (A) preheats to 40 degreeC with respect to 10 degreeC of external temperature, (B) shows the case where it preheats to 25 degreeC.

Claims (2)

  In a method of manufacturing a cathode whose surface is masked with an insulating material so as to obtain electric nickel of a special shape by electrowinning, a one-component epoxy resin is used as an insulating material to be applied to the cathode base plate for masking. A method for producing a cathode for electrolytic collection of special-shaped electronickel, characterized in that the kinematic viscosity at the time of application of the conductive epoxy resin is kept at 10,000 to 30,000 cSt regardless of the outside temperature.   When the one-component epoxy resin is preheated, it is preheated to a resin temperature Y that satisfies the relationship of Y = −0.82X + 48.27 with respect to the outside air temperature X, and is applied to the cathode base plate within one hour immediately after preheating. The method for producing a cathode for electrowinning specially shaped electronickel according to claim 1, wherein:

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