JPH0515797B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for fixing a diaphragm in a diaphragm electrode device for electrodeposition coating, and in particular, a diaphragm is arranged around the outside of the electrode so as to surround the electrode. The present invention also relates to a method for fixing a diaphragm of a diaphragm electrode device for electrodeposition coating for firmly securing the cylindrical diaphragm.

[Conventional technology]

Electrodeposition coatings can be roughly divided into those using anionic paints and those using cationic paints, but in both cases, the uniformity and adhesion of the coating film to the object being coated are excellent. In addition, since it generates little pollution, it has recently been widely applied, for example, to automatic coating treatment of automobile bodies, as it is particularly suitable for undercoating or one-coat finishing of metal coatings.

Among the paints used for such electrodeposition coatings, the aforementioned anionic paints include, for example,
2000 resin to which a carboxyl group is attached to make it water-soluble is used, and as the cationic paint, a resin component of the paint is made water-soluble by attaching an amino group to the resin component. On the other hand, even with these water-soluble paints, the degree of ionization after being dissolved in water is weak. For this reason, at present, aonine-type paints are mixed with alkaline neutralizers such as triethylamine, and kaotine-type paints are mixed with acidic neutralizers such as acetic acid. Those designed to increase the degree of ionization are used.

In this way, a neutralizing agent is mixed to increase the degree of ionization depending on the properties of the resin component of each paint, but on the other hand, as the electrodeposition process of the coating progresses, the resin component of the paint in the solution increases. When the paint decreases, the paint must be replenished from the outside, so amine or acetic acid as a neutralizing agent is continuously accumulated in the solution, causing re-dissolution of the painted surface or development problems such as the formation of pinholes. This results in a situation where the efficiency of electrodeposition coating is significantly impaired. For this reason, in recent years, as seen in Japanese Patent Publication No. 45-22231, for example, one electrode is separated from the object to be coated and the aqueous solution using an ion exchange membrane or the like, and the ions are So-called PH control has been carried out and is being effective, in which amine or acetic acid is permeated and extracted from the aqueous solution using an exchange membrane or the like to prevent an increase in the amount of the neutralizing agent in the aqueous solution.

On the other hand, the aqueous solution surrounding the object to be coated in the electrodeposition bath is constantly stirred in order to increase the electrodeposition efficiency, and the aqueous solution that surrounds the object to be coated in the electrodeposition bath is constantly stirred to increase the electrodeposition efficiency. Water is also supplied continuously from outside in small amounts. For this reason,
Irregular large and small alternating pressures are constantly applied to the flat plate-shaped ion exchange membrane repeatedly from both sides, either impulsively or gently. Specifically, in addition to stirring the aqueous solution for electrodeposition described above, the process of transporting the objects to be coated into and out of the bathtub, as well as the process in which the objects to be coated suspended from the line are transported inside the bathtub, is carried out. , the alternating pressure mentioned above is generated. For example, in the case of a commonly used ion exchange membrane (about 1 m in height and 50 cm in width), this change in water pressure can
If a change in water pressure of 0.5Kg/ ^cm2 occurs, the water pressure will change by 2500Kg in the entire membrane, and a tension of about 8.5Kg/cm is repeatedly applied to the attachment part of the membrane in the direction perpendicular to the center line. (In this case, if a bulge was formed at an angle of approximately 10° to the center line, the tension would be 48 kg/cm in the tangential direction of the bulge due to [8.5/sin10°]). For this reason, the ion exchange membrane is always in a state where its part or front part is bent, and bending and tension are applied repeatedly, so thin membranes cannot be used at all, while thick membranes cannot be used for a short period of time. (actually 2 days ~
There are many inconveniences where the product breaks down within 3 days. This creates a situation where the ion exchange membrane has to be replaced regularly in a short period of time, and the replacement work requires the preparation of a crane, etc. In addition, the electrodeposition coating line A situation arises in which the system itself must also be stopped.

Furthermore, impurities that have passed through the ion exchange membrane or impurities in the water adhere to the area around the other electrodes and become polarized, and furthermore, development such as the adhesion of air bubbles occurs due to water electrolysis. The dripping water supply method cannot completely remove these polarized particles and air bubbles, resulting in the disadvantage that the electrodeposition efficiency decreases over time. For this reason, the electrodeposition coating using the diaphragm electrode method in the prior art has been disadvantageous in that the working efficiency is extremely low and the cost is therefore high.

On the other hand, with the aim of improving such disadvantages, the inventor has already developed a diaphragm electrode device formed into a tubular shape (Utility Model Application No. 57-082002; U.S. Patent No. 499818
No.) is proposed.

This refers to the other electrode, which is disposed corresponding to the object to be coated, and specifically, it refers to "the outer surface of a tubular diaphragm support member that is water permeable and made of an insulating material. Along with wrapping the diaphragm,
A tubular electrode is disposed on the inner surface of the diaphragm support member with a predetermined diaphragm therebetween, and pure water flows from above to below the inner diameter side of the tubular electrode and further to the outside through the outer peripheral surface of the tubular electrode. It is designed to have a water passageway.

[Problem that the invention seeks to solve]

However, even in the above conventional diaphragm electrode device in which a diaphragm is wound, there are some unresolved problems in the method of attaching the diaphragm disposed around the electrode.

That is, in the above-mentioned diaphragm electrode device, the diaphragm is attached with its upper and lower ends tightened around the outer surface of the diaphragm support member by a belt-like member. For this reason, due to changes in water pressure that repeatedly and irregularly arrive from inside and outside, the diaphragm becomes misaligned at both ends over time, and as a result, when used continuously for a long period of time, There has been a problem in that the polar liquid leaks from both ends of the diaphragm or the coating liquid flows into the inside of the diaphragm, impeding the original function of the diaphragm.

Furthermore, in the case of a diaphragm made of a resin that is difficult to adhere to, such as olefin or Teflon,
In order to attach and fix the diaphragm to the diaphragm support member, it is troublesome to have to sew each abutting edge or use other fixing fittings, etc., and the structure becomes complicated, making it difficult to process and assemble. The problem was that it took a lot of time.

[Purpose of the invention]

The present invention improves the disadvantages of such conventional examples, and provides a diaphragm for electrodeposition coating that can be attached to a diaphragm support member very easily and robustly even when the diaphragm is made of a material such as a resin with particularly poor adhesiveness. The object is to provide a method for fixing a diaphragm of an electrode device.

[Means for solving problems]

Therefore, in the present invention, the other electrode is arranged to correspond to the object to be coated as one electrode, and the diaphragm is provided to separate the other electrode from the one electrode and the paint components of the electrodeposition aqueous solution. This diaphragm is installed around the outer surface of a tubular diaphragm support member made of an insulating material with a liquid flow structure, and the other electrode is arranged inside this diaphragm support member, and this other electrode and the diaphragm support member In a diaphragm electrode device for electrodeposition coating, which has a water flow mechanism for forcing water to flow from one side to the other, when installing the diaphragm around the outer surface of the diaphragm support member, first set the diaphragm in a rectangular shape. a first step of arranging a diaphragm support member inside and bending each end of the diaphragm along the outer surface of the diaphragm support member; A second step of engaging and integrating the support member directly or indirectly through another member along the outer surface of the support member, and a second step of engaging and integrating the support member along the outer surface of the diaphragm supporting member; , a third step of spirally winding a water-permeable outer cloth and fixing the diaphragm in a laminated state around the outer surface of the diaphragm support member;
It has this configuration. This aims to achieve the above-mentioned purpose.

[Effect]

Since the diaphragm is laminated on the outer surface of the cylindrical diaphragm support member, its edges are bent and engaged, and the entire diaphragm is wound spirally with the outer cloth, the winding fixing force of the outer cloth is This maintains the bent engagement state of the edges of the diaphragm and strengthens its integration. Therefore, the diaphragm is firmly attached to the outer periphery of the diaphragm support member without using any particular adhesive.

[First Embodiment] The first embodiment of the present invention will be described below with reference to FIGS. 1 to 6.
This will be explained based on the diagram.

In these figures, reference numeral 1 indicates a diaphragm electrode device as the other electrode disposed in the aqueous solution for electrodeposition coating in correspondence with one electrode (object to be coated) not shown. This diaphragm electrode device 1 includes a main body portion 2, an electrode portion 3, and a water passage mechanism 4 set between the two.

The main body 2 includes first and second insulating tubes 5 and 6 coaxially arranged with a predetermined diaphragm in between, and a relatively hard diaphragm support member 7 that connects each of these insulating tubes 5 and 6. It is composed of a diaphragm 9 wrapped around the outer periphery of the diaphragm support member 7 as shown in FIG. 2, and an outer cloth 8 wound spirally around the outer surface of the diaphragm 9 as described later. The outer cloth 8 is made of, for example, chemical fiber, and is sufficiently durable against tension and has water permeability.

The diaphragm support member 7 is formed into a relatively long tube shape using a non-conductive mesh member or a water-permeable porous member, and supports the first and second insulating tubes 5 and 6 on the inner diameter side of both ends thereof. Arranged to connect.

Further, the diaphragm 9 is formed of an ion exchange membrane that is selectively permeable to the ions attracted to the electrode section 3 described above. Here, this diaphragm 9
In addition to an ion exchange membrane, the membrane may be formed of a neutral membrane, that is, one that does not have selectivity but blocks the flow of relatively large molecules and easily allows small molecules to pass through. This ion exchange membrane (or neutral membrane)
is wound around the diaphragm supporting member 7 as the diaphragm 9, so that its mechanical strength against external pressure is significantly increased.

Further, the outer peripheral surface of the diaphragm 9 is spirally wrapped with the outer cloth 8 as described above over the entire area, thereby adding sufficient pressure resistance against internal pressure. It's summery.

On the outer circumferential side of both ends of the diaphragm support member 7 around which the diaphragm 9 and the outer cloth 8 are wound, first
As shown in the figure, first and second frames 20 and 21 are arranged, and at the same time, the potting material 11 is filled on the inner diameter side of these frames 20 and 21, thereby
Each insulating tube 5, 6, diaphragm support member 7 and diaphragm 9,
It has a structure in which the outer cloth 8 is simultaneously and firmly integrated. In this case, the first frame 20 is formed into a cylindrical shape, and when filling the potting material 11, the potting material 11 before solidification is filled with the potting material 11.
A ring member 12 is disposed within the first frame 20 to prevent the liquid from flowing out.

Further, the second frame 21 is formed into a cylindrical shape with a bottom, and with the diaphragm support member 7 and the insulating tube 6 etc. inserted thereinto, the potting material 11 is filled as described above, and the whole is filled with the potting material 11. At the same time, it has an integrally fixed structure.

Although epoxy resin is used as the potting material 11 in this embodiment, it may also be urethane resin, phenol resin, or the like.

As the first and second insulating tubes 5 and 6, hard vinyl chloride tubes are used in this embodiment.

Of these, the first insulating tube 5 is provided with a drainage section 13 as shown in FIG. 1, and a cap 14 is detachably provided at its upper end. 5A indicates a spacer fixed to the inner diameter side of the upper end of the insulating tube 5.

On the other hand, the electrode part 3 includes a tubular electrode 30 made of stainless steel and formed into a tubular shape, and a first electrode of the tubular electrode 30.
It is composed of a metal lid member 31 for locking the electrode hanging, which is attached to the upper end in the figure, and a power supply connection terminal 32 and a water supply part 33 provided on this lid member 31. Among these, the tubular electrode 30 has an outer diameter smaller than the inner diameter of each of the first and second insulating tubes 5 and 6 of the main body portion 2 described above. Therefore, the tubular electrode 3 relative to the main body 2
At the same time, a part of the water passage mechanism 4 is formed between the main body part 2 and the tubular electrode 30. Further, the outer peripheral edge of the electric metal lid member 31 projects from the tubular electrode 30, so that the tubular electrode 30 is locked with the first insulating tube 5 as shown in FIG. It is becoming more and more common. Therefore, the electrode part 3 is
It is very easily inserted into the main body 2 from the outside,
Also, it can be easily removed to the outside if necessary.

The water flow mechanism 4 is for discharging acetic acid and the like accumulated between the diaphragm 9 and the tubular electrode 30 to the outside, and is specifically constituted by the electrode section 3 and the main body section 2 described above. . That is, the water flowing from the water supply part 33 of the electrode part 3 flows down inside the tubular electrode 30, as shown by the arrow in FIG. 11, and flows from below to the outer circumferential side of the tubular electrode 30. At the same time, the liquid flows inside the diaphragm 9 while rising on the outer peripheral side of the tubular electrode 30, and is forced to flow out from the discharge part 13 together with impurities.

An attachment fitting 1A for attachment to a bathtub during electrocoating is wrapped around one frame 20 portion of the main body 2. In addition, an outer cloth 8 wrapped around the outer surface of the diaphragm 9
is not necessarily limited to a cloth-like member, and may be replaced with another member as long as it has the same reinforcing function and water permeability. Furthermore, the diaphragm 9 may be wound spirally or may be formed into circular slices and may be attached on the premise that the joint portion is waterproof.

Here, the method for fixing the diaphragm 9, which constitutes the main part of the main body 2 mentioned above, will be further explained.

First, a square membrane is used as the diaphragm 9, and the diaphragm support member 7 is arranged inside, and each end thereof is bent along the outer surface of the end membrane support member 7 (first step). . Next, both ends of the bent diaphragm 9 are directly engaged and integrated along the outer circumference of the diaphragm support member 7 (second step). Next, the water-permeable outer cloth 8 is spirally wound around the outer surface of the diaphragm 9 that is laminated around the outer surface of the diaphragm support member, and the diaphragm 9 is laminated around the outer surface of the diaphragm support member 7. (3rd
process).

To explain this in more detail, first, the diaphragm 9 is formed into a relatively wide band shape. Next, a diaphragm support member 7 is arranged approximately parallel to the longer edge of this diaphragm 9, and the diaphragm 9 is laminated on this diaphragm support member 7. The long side edges 9A and 9B of the diaphragm 9 are pasted together so as to protrude from the diaphragm support member 7 (see FIG. 4). For bonding each edge, a suitable adhesive (for example, epoxy resin, urethane resin, etc.) is used.

Next, each end edge 9A, 9B of the diaphragm 9 pasted together in this way is bent in two steps as shown in FIG. 5, and then the outer cloth 8 is wrapped as shown in FIG. Wrap it all in a spiral. This completes the integration of the diaphragm support member 7 and the diaphragm 9. Next, at both ends of the thus formed cylindrical diaphragm member, the above-mentioned first and second
The insulating tubes 5 and 6 are fitted together as shown in FIG.
At the same time, the first and second frames 20 and 21 are arranged at a predetermined interval on the outside of each fitting portion as described above. Then, the potting material 11 is filled into each of the frames 20 and 21 and solidified, thereby completing the integration of the main body portion 2.

Here, the seal member 12 disposed inside the lower end of the first frame 20 in FIG. 1 is for preventing the potting material 11 from flowing out before solidification, as described above, and Material 11
It can be removed after it solidifies.

Next, the overall operation of this embodiment will be explained in the case where a cationic paint is used.

First, the object to be coated (not shown) and the diaphragm electrode device 1 are placed in an aqueous solution of a cationic paint neutralized with acetic acid.
When a DC voltage is applied using the object to be coated as a negative electrode and the tubular electrode 30 of the diaphragm electrode device 1 as a positive electrode, electrode coating starts immediately, and the paint resin component and pigment, which have a positive charge, are mixed in an aqueous solution. The colloid molecules move toward the object to be coated as the negative electrode, adhere to the surface of the object, and discharge, and then the solid matter of the paint aggregates to form a coating film. On the other hand, acetic acid having a negative charge is accumulated in the aqueous solution, and this acetic acid starts moving toward the tubular electrode 30 of the diaphragm electrode device 1 at the same time as the above-mentioned electrodeposition coating starts. .

The diaphragm 9 is an anionic membrane (or neutral membrane) that allows negatively charged acetic acid molecules to easily pass through, since a cationic paint is dissolved in an aqueous solution for electrodeposition. Therefore, as described above, acetic acid molecules attracted to the tubular electrode 30 at a positive potential easily pass through the diaphragm 9, reach the tubular electrode 30 from around the tubular electrode 30, and are discharged. In this case, since the diaphragm 9 is an ion exchange membrane,
It is relatively impermeable to the discharged neutralizing agent, and therefore acetic acid accumulates between the tubular electrode 30 and the diaphragm 9. On the other hand, this tubular electrode 3
As described above, since pure water is forced to flow between the diaphragm 9 and the diaphragm 9, the accumulated acetic acid is continuously discharged to the outside together with the pure water.

As described above, in this embodiment, the other electrode disposed corresponding to the object to be coated as one electrode is the tubular electrode 30, and the diaphragm support member made of an insulating material is provided around the tubular electrode 30. Since a diaphragm 9 such as an ion exchange membrane is laminated through the diaphragm 7, it can sufficiently withstand the above-mentioned fluctuations in external pressure.
Therefore, even if the same diaphragm 9 as the conventional diaphragm is used, it can be used continuously for a long time, and water is forced to flow through the diaphragm support member 7 portion from below to above. Therefore, the polarized particles and air bubbles stagnant around the tubular electrode 30 can be forcibly removed, and the efficiency of electrodeposition coating can be significantly improved. 100% neutralizing agent such as acetic acid
In this respect, conventional diaphragm electrode devices had the effect of simply diluting the neutralizing agent such as acetic acid accumulated around the electrode with water. In this embodiment, this point is also significantly improved, and therefore the efficiency of extracting the neutralizing agent by the diaphragm 9 can be significantly improved.

Further, since the tubular electrode 30 can be easily removed from the inside of the main body 2, maintenance is extremely easy, and there is an advantage that accessory equipment such as a crane is not required at all.

In addition, in this embodiment, since the water-permeable outer cloth 8 is wound around the inner and outer surfaces of the diaphragm 9, the diaphragm 9
Even if its tensile strength is extremely low, it has the advantage of being able to withstand changes in internal pressure.

Furthermore, the potting material 11 can be uniformly filled due to the action of the frames 20 and 21, which has the advantage that uniformity of strength and uniformity of quality can be obtained, and the labor of assembly work is also reduced. be.

Furthermore, even if a diaphragm made of a material with weak adhesiveness is used, the diaphragm can be firmly attached to the diaphragm support member due to the winding and fixing action of the outer cloth around the bent engagement portion of the edge. .

Here, in this embodiment, the other electrode mentioned above is the tubular electrode 30, but the present invention is not necessarily limited to this, and it may be columnar, for example, on the premise that the water passage mechanism 4 is secured. It may be a long and thin plate.

[Second Embodiment] Next, a second embodiment will be described based on FIG. 7.

This embodiment has a structure in which both ends of the diaphragm are pulled out, overlapped, bent to one side, turned over, and then the outer cloth 8 is wrapped around the diaphragm. As shown in Fig. 7, each edge on the long side is individually bent outward, and between the bent portions 90A and 90B, there is provided a strip-shaped engagement strip with both ends bent inward. The connecting pieces 91 are connected, and then the outer cloth 8 is wrapped and fixed. Although the connecting piece 91 is made of the same material as the diaphragm 9 described above in this embodiment, it may be made of other synthetic resin or metal material. The other configurations are completely the same as the first embodiment described above.

Even in this case, in addition to having the same function and effect as the first embodiment described above, there is an advantage that a particularly narrow diaphragm member can be used effectively, and the bulges of the bent portions 90A and 90B can be kept small. Therefore, it has the advantage of being easy to assemble and easy to handle.

〔Effect of the invention〕

Since the present invention is configured and functions as described above,
According to this, it is possible to firmly fix the diaphragm to the diaphragm support member, and in particular, it is possible to fix the diaphragm to the diaphragm support member described above in substantially the same way as when it is adhered to a diaphragm that does not have adhesive properties. By adopting this method, it is possible to obtain a diaphragm electrode device for electrodeposition coating that has good durability and does not peel off even when a non-adhesive diaphragm is used, which is an unprecedented and excellent electrodeposition coating. A method for fixing a diaphragm of a diaphragm electrode device can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention, FIG. 2 is a sectional view taken along the - line in FIG. 1, and FIG. 3 is an enlarged partial explanatory view of a part of FIG. Fourth
6 to 6 are explanatory diagrams showing the winding procedure of the diaphragm, FIG. 7 is a schematic configuration diagram showing the second embodiment, and FIG.
The figure is an explanatory diagram showing the usage state of the embodiment of FIG. 1. 7... Diaphragm support member, 8... Outer cloth, 9... Diaphragm, 9A, 9B... Each end of the long side of the diaphragm, 91
...Connection piece.

Claims (1)

[Scope of Claims] 1. Another electrode arranged corresponding to the object to be coated as one electrode, and a diaphragm that separates the other electrode from the one electrode and the paint components of the electrodeposition aqueous solution. The diaphragm is installed around the outer surface of a tubular diaphragm support member made of an insulating material and has a liquid flow structure, and the other electrode is disposed inside the diaphragm support member, and the other electrode is connected to the other electrode. In the diaphragm electrode device for electrodeposition coating, which is provided with a water flow mechanism for forcing water to flow from one side to the other between the diaphragm support member, when the diaphragm is installed around the outer surface of the diaphragm support member, a first step of using a rectangular diaphragm as the diaphragm, arranging the diaphragm support member inside and bending each end of the diaphragm support member along the outer surface of the diaphragm support member; a second step of engaging and integrating both ends of the diaphragm along the outer surface of the diaphragm support member directly or indirectly through another member; and a third step of spirally winding a water-permeable outer cloth around the outer surface of the laminated diaphragm and fixing the diaphragm in a laminated state around the outer surface of the diaphragm support member. A method for fixing a diaphragm of a diaphragm electrode device for electrodeposition coating, characterized by: