JP2010236028A - Electrolytic degreasing apparatus and electrolytic degreasing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrolytic degreasing apparatus and an electrolytic degreasing method, capable of sufficiently carrying out a degreasing process even for a composite material prepared by laminating a resin layer and a metal layer, while preventing peeling from an end portion of the material. <P>SOLUTION: The electrolytic degreasing apparatus 1 for a composite material 20 prepared by laminating a resin layer 21 and a metal layer 22 includes: a main electrode 2 opposing to the metal layer; an auxiliary electrode 4 positioned closer to an end portion 20e of the composite material than the main electrode; a first power supply 6 for applying an electric current between the metal layer and the main electrode; and a second power supply 7 having an anode connected to the main electrode and a cathode connected to the auxiliary electrode. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrolytic degreasing apparatus and an electrolytic degreasing method for electrolytic degreasing a composite material formed by laminating a resin layer such as a resin film or a resin coating film and a metal layer such as a copper foil.

Conventionally, when a metal material is subjected to a treatment such as plating, the surface of the metal material is removed to improve adhesion with a plating film or the like, and electrolytic degreasing has been performed to prevent poor quality such as plating repellency. (See Patent Document 1).
On the other hand, a structure in which a resin layer or a film is laminated on one surface of a copper foil or a copper alloy foil and an Sn plating film is formed on the other surface is used as an in-vehicle electromagnetic shielding material. When Sn plating is performed on such a shield material, a composite material obtained by laminating a copper foil and a resin layer is electrolytically degreased and Sn-plated, or after copper foil is electrolytically degreased before laminating with a resin layer In some cases, Sn plating is performed after laminating with the resin layer. However, it is preferable to electrolytically degrease a composite material obtained by laminating a copper foil and a resin layer in that the surface of the copper foil can be cleaned immediately before Sn plating.

JP 2007-92104 A

However, if the copper plate material alone is not laminated with the resin layer, it can be electrolytically degreased using a conventional electrolytic degreasing tank or the like, but in the case of a composite material in which a copper foil and a resin layer are laminated, In addition, there is a problem that peeling occurs between the resin layer and the copper foil at the end of the composite material. In particular, peeling is likely to occur when a thin material of about several μm such as a copper foil is used as the metal layer.
For this reason, when the composite material is degreased, electrolysis is not performed, but the composite material is merely immersed in a degreasing solution, which causes a problem that sufficient degreasing cannot be performed. In addition, if the part of the composite material where the peeling occurs is slit and removed, the yield is reduced.
That is, the present invention has been made to solve the above-described problems, and even when electrolytically degreasing a composite material formed by laminating a resin layer and a metal layer, peeling from the end portion hardly occurs and sufficient degreasing is achieved. An object of the present invention is to provide an electrolytic degreasing apparatus and an electrolytic degreasing method capable of performing the above.

In order to achieve the above object, an electrolytic degreasing apparatus of the present invention is a composite electrolytic degreasing apparatus formed by laminating a resin layer and a metal layer, the main electrode facing the metal layer, and the main degreasing apparatus. An auxiliary electrode located on the end side of the composite material from the electrode, a first power source for passing a current between the metal layer and the main electrode, an anode side connected to the main electrode, and the auxiliary electrode And a second power source to which the cathode side is connected.
In this way, current flows also from the main electrode to the auxiliary electrode during electrolytic degreasing, reducing current concentration at the end of the composite material, and the resin layer and metal layer associated with the hydrogen gas generated at the end. Peeling can be prevented.

It is preferable that the potential of the second power source is controlled so that the current density of the auxiliary electrode is 0.6 times or more the current density of the metal layer.
The auxiliary electrode is preferably made of the same material as the metal layer, or made of stainless steel.
The metal layer may be a copper foil or a copper alloy foil.

  The electrolytic degreasing method of the present invention is an electrolytic degreasing method of a composite material formed by laminating a resin layer and a metal layer, and a main electrode facing the metal layer, and an end side of the composite material from the main electrode And an auxiliary electrode positioned at the center, and a current is passed between the metal layer and the main electrode, and a current is passed from the main electrode to the auxiliary electrode.

  According to the present invention, even when a composite material formed by laminating a resin layer and a metal layer is electrolytically degreased, peeling from the end portion hardly occurs and sufficient degreasing can be performed.

1 is an overall configuration diagram of an electrolytic degreasing apparatus according to an embodiment of the present invention. It is a figure which shows arrangement | positioning of a main electrode and an auxiliary electrode.

Hereinafter, an electrolytic degreasing apparatus according to an embodiment of the present invention will be described.
FIG. 1 shows an example of the overall configuration of an electrolytic degreasing apparatus 1 according to an embodiment of the present invention. The electrolytic degreasing apparatus 1 includes an electrolytic degreasing tank 9 for storing a degreasing liquid, a current-carrying roll 12 and an upper roll 10 on the electrolytic degreasing tank 9, and sinker rolls 8a and 8b disposed in the electrolytic degreasing tank 9, and a composite material strip 20 is stretched from the energizing roll 12 to the upper roll 10 via the sinker rolls 8 a and 8 b, and the composite strip 20 is continuously run to enter and exit the electrolytic degreasing tank 9. Further, the main electrode 2 is vertically arranged facing the outside of the composite material strip 20 stretched between the upper roll 10 and the sinker roll 8a. Similarly, the main electrode 2 is stretched between the energizing roll 12 and the sinker roll 8b. The other main electrode 2 is arranged vertically so as to face the outside of the composite material strip 20. As the degreasing liquid, an alkaline aqueous solution such as a sodium hydroxide aqueous solution can be used.
As will be described later, the composite material strip 20 is formed by laminating a resin layer 21 and a copper foil (metal layer) 22 so that the copper foil 22 side faces the main electrode 2.

Then, current flows between the composite material strip 20 serving as a cathode and the main electrode 2 serving as an anode by a first power source (rectifier) (not shown) connected between the energizing roll 12 and the main electrode 2, and on the composite material strip 20. Hydrogen is generated as a cathode reaction, and a degreasing effect is generated by bubbles at this time.
The composite material strip 20 is supplied from the uncoiler to the electrolytic degreasing apparatus 1 via the upper roll 10. Moreover, the composite material strip 20 processed by the electrolytic degreasing apparatus 1 is supplied to the pickling tank (not shown) via the energizing roll 12, and after pickling, it is applied to the Sn plating apparatus (not shown). Then, Sn plating is performed on the copper foil 22. As the Sn plating apparatus, a known apparatus can be used. For example, in addition to a vertical plating apparatus, all plating apparatuses such as a horizontal type and a drum type can be applied.

FIG. 2 shows the arrangement of the main electrode 2 and the auxiliary electrode 4 of the electrolytic degreasing device 1 when the electrolytic degreasing device 1 is viewed from above (when viewed from a direction perpendicular to the traveling direction of the composite material strip 20). It is a top view.
In FIG. 2, the composite material strip 20 is formed by laminating a resin layer 21 and a copper foil (metal layer) 22, and a flat main electrode 2 is disposed so as to face the copper foil 22. In addition, two flat auxiliary electrodes 4 are disposed so as to be opposed to both end portions 20e and 20e of the composite material strip 20, respectively. The surface of the auxiliary electrode 4 is parallel to the end face of the composite material strip 20.

  The main electrode 2 and the auxiliary electrode 4 are electrically connected to a first power source 6 and a second power source 7, respectively. Each power source 6 and 7 may be a rectifier. First, the anode terminal (+) of the first power source 6 is connected to the main electrode 2, and the cathode terminal (−) is connected to the composite material strip 20. On the other hand, the anode terminal (+) of the second power source 7 is connected to the main electrode 2, and the cathode terminal (−) is connected to the two auxiliary electrodes 4.

Next, the operation of the auxiliary electrode 4 will be described. Conventionally, there has been a technique of providing an auxiliary electrode during electroplating, but this is to prevent plating overcoat at the end of the material to be plated.
On the other hand, electrolytic degreasing uses a degreasing target as a cathode to perform electrolysis in a degreasing solution, generates hydrogen on the surface of the degreasing target, and obtains a degreasing effect by the bubbles. Therefore, normally, current concentration (and bubble concentration) at the end of the object to be degreased is not particularly problematic.
However, when electrolytic degreasing of a composite material formed by laminating a resin layer and a metal layer is performed, the resin layer and the metal layer are peeled from the end portion. This is presumably because a large amount of hydrogen is generated when the current concentrates at the end of the composite material, enters between the resin layer and the metal layer, and peels off both. Therefore, in the composite material, it is necessary to prevent current concentration at the end during electrolytic degreasing. Therefore, by providing an auxiliary electrode and flowing current from the main electrode to the auxiliary electrode during electrolytic degreasing, current concentration at the end of the composite material is reduced and peeling between the resin layer and the metal layer is prevented. Can do.
Specifically, as shown in FIG. 2, power sources for the main electrode 2 and the auxiliary electrode 4 are provided separately, the anode terminal (+) of the second power source 7 is connected to the main electrode 2, and the cathode terminal (-) is connected. When connected to the auxiliary electrode 4, part of the current concentrated from the main electrode 2 to the end of the composite material 20 flows to the auxiliary electrode 4, and current concentration to the end of the composite material is reduced.

Examples of the composite material 20 applied to the present invention include those obtained by laminating a resin film on a metal layer, and those obtained by casting a molten resin that is flowed through the metal layer and cured to form a resin layer.
Further, as described above, peeling between the resin layer and the metal layer due to hydrogen bubbles generated during electrolytic degreasing tends to occur as the metal layer is thinner. In this respect, the present invention is particularly effective when the thickness of the metal layer is 20 μm or less.

It is preferable that the potential of the second power supply 7 is controlled so that the current density of the auxiliary electrode 4 is 0.6 times or more of the current density of the metal layer 22. As a result, a potential difference is generated between the metal layer 22 and the auxiliary electrode 4, and a part of the current flowing from the main electrode 2 to the metal layer 22 flows to the auxiliary electrode 4.
It is preferable that the current density of the auxiliary electrode 4 is higher than the current density of the metal layer 22, but if it is too high, degreasing of the metal layer near the auxiliary electrode may be insufficient. Accordingly, the current density of the auxiliary electrode 4 is preferably 0.6 to 5 times, more preferably 1 to 3 times that of the metal layer 22. For example, when the current density of the metal layer 22 is 3 A / dm ² , the current density of the auxiliary electrode 4 is preferably in the range of 3 to 9 A / dm ² .
The distance of the auxiliary electrode 4 from the end 20e of the composite material strip 20 is preferably 30 to 200 mm. However, the higher the current density of the auxiliary electrode 4, the longer the distance, and the lower the current density, the shorter the distance. . When the distance from the strip is short, there is a high possibility that the strip and the auxiliary electrode come into contact with each other due to the meandering of the strip. When the strip and the auxiliary electrode are touched, a defect in which the end portion of the strip is broken or a defect in which a spark is generated when the current density is different between the strip and the auxiliary electrode is likely to occur. On the other hand, if the strip and the auxiliary electrode are separated too much, it is necessary to increase the current density of the auxiliary electrode.

As described above, the current density of the auxiliary electrode is preferably 0.6 to 5 times the current density of the metal layer. If the current density of the metal layer is in an appropriate range, the current density of the auxiliary electrode can be determined accordingly. . If the current density of the metal layer is lowered, the resin layer does not peel off at the edge of the composite material, but on the other hand, degreasing failure occurs. For this reason, the current density of the metal layer is preferably ³ to 10 A / dm ² .

The position where the auxiliary electrode 4 is disposed with respect to the end 20e of the composite material strip 20 is not particularly limited, and may be positioned on the main electrode 2 end 20e side. For example, the auxiliary electrode 4 may be disposed before and after the end portion 20e of the composite material strip 20 (the front surface and the back surface side of the composite material strip 20), respectively, and viewed from the end portion 20e of the composite material strip 20. Thus, the auxiliary electrode 4 may be disposed diagonally forward or diagonally behind (a position shifted to either the front surface or the back surface of the composite material strip 20), and the shape of the auxiliary electrode 4 is not limited.
It is preferable that the auxiliary electrode 4 is made of the same material as that of the metal layer 22 of the composite material strip 20 because the problem of contamination does not occur even if the components of the auxiliary electrode 4 are dissolved in the degreasing liquid. In addition, it is preferable that the auxiliary electrode 4 is made of stainless steel because the components of the auxiliary electrode 4 are difficult to dissolve in the degreasing liquid.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

The composite material strip 20 was electrolytically degreased using the electrolytic degreasing apparatus 1 shown in FIGS. As the composite material strip 20, a rolled copper foil (7.8 μm) on which one side of a PET film (12.5 μm) is laminated via a 3 μm thick adhesive layer (width (W) 600 mm) is used. The exposed surface was opposed to the main electrode 2 of the electrolytic degreasing apparatus 1. As the degreasing liquid, an alkaline aqueous solution (Pacna P105 manufactured by Yuken Industry Co., Ltd.) 40 g / L was used, and the liquid temperature was 50 ° C. Electrolytic degreasing was performed at a current density shown in Table 1 at a line speed of 5 m / min during degreasing. The distance between the end 20e of the composite material strip 20 and the auxiliary electrode 4 was set to 50 mm or 100 mm.
The main electrode 2 was a stainless steel plate, and the auxiliary electrode 4 was a copper plate.

<Presence or absence of peeling of the resin layer at the end of the composite material>
The edge part of the sample after electrolytic degreasing was cut and embedded in the resin, and the cross section was polished and observed with an optical microscope at 400 times (or 1000 times) to evaluate the presence or absence of PET film (resin layer) peeling.
<Presence / absence of defects at the end of the composite material>
The surface of the composite material was visually observed, and the presence / absence of bending of the end portion was visually evaluated.
<Presence / absence of degreasing failure of composite material>
The surface of the composite material was visually observed, and the presence or absence of stains and patterns that were present on the plating surface and caused by stains on the plating material was visually evaluated.
<Comprehensive judgment>
Judgment was made according to the following criteria.
A: No peeling of the resin layer, no bending of the end portion, no degreasing failure ×: There is at least one of peeling of the resin layer, bending of the end portion (because the yield deteriorates), or degreasing failure

  For Examples 1 to 4, the auxiliary electrode 4 of FIG. 2 was used, but in the case of Comparative Examples 1 and 4, the auxiliary electrode 4 was not energized. The obtained results are shown in Table 1.

As is clear from Table 1, in the case of Examples 1 to 6 in which the auxiliary electrode 4 is used and the current density of the auxiliary electrode 4 is 0.6 times or more of the current density of the metal layer 22, the comprehensive determination is good. It was. This is considered because a potential difference is generated between the metal layer 22 and the auxiliary electrode 4, and a part of the current flowing from the main electrode 2 to the metal layer 22 flows to the auxiliary electrode 4.
On the other hand, in the case of Comparative Example 1 where no auxiliary electrode was used, peeling occurred.
Further, although the auxiliary electrode was used, the distance between the strip and the auxiliary electrode was extremely separated as 250 mm, and in the case of Comparative Example 2 in which the current density of the auxiliary electrode 4 was less than 0.6 times the current density of the metal layer 22, peeling was performed. Produced.
Although the auxiliary electrode 4 was used, in the case of Comparative Example 3 in which the distance between the strip and the auxiliary electrode was extremely close to 5 mm, the strip end portion was broken.
In the case of Comparative Example 4 in which the auxiliary electrode was not used and the current density of the metal layer 22 was less than 3 A / dm ² , peeling did not occur, but a degreasing defect was observed.

DESCRIPTION OF SYMBOLS 1 Electrolytic degreasing apparatus 2 Main electrode 4 Auxiliary electrode 6 1st power supply 7 2nd power supply 20 Composite material strip 20e End part of composite material 21 Resin layer 22 Metal layer

Claims (5)

An electrolytic degreasing device for a composite material formed by laminating a resin layer and a metal layer,
A main electrode facing the metal layer;
An auxiliary electrode located on the end side of the composite material from the main electrode;
A first power source for passing a current between the metal layer and the main electrode;
A second power source having an anode side connected to the main electrode and a cathode side connected to the auxiliary electrode;
An electrolytic degreasing apparatus comprising: 2. The electrolytic degreasing apparatus according to claim 1, wherein the potential of the second power source is controlled so that the current density of the auxiliary electrode is 0.6 times or more of the current density of the metal layer. The electrolytic degreasing apparatus according to claim 1 or 2, wherein the auxiliary electrode is made of the same material as the metal layer or made of stainless steel. The electrolytic degreasing apparatus according to claim 1, wherein the metal layer is a copper foil or a copper alloy foil. An electrolytic degreasing method for a composite material formed by laminating a resin layer and a metal layer,
Using a main electrode facing the metal layer and an auxiliary electrode located on the end side of the composite material from the main electrode,
An electrolytic degreasing method in which a current is passed between the metal layer and the main electrode and a current is passed from the main electrode to the auxiliary electrode.

Images