JPH0469237B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for fixing a diaphragm for electrodeposition coating,
In particular, the present invention relates to a method of fixing a diaphragm for electrodeposition coating, in which the diaphragm is disposed around the outer surface of the electrode so as to surround the electrode, and the diaphragm is firmly secured to 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 to the object are excellent. In addition, since it generates little pollution, it has recently been widely applied as a material particularly suitable for undercoating or one-coat finishing of metal coatings, for example, for automatic coating treatment of automobile bodies.

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 type paint, a resin component is used which is made water-soluble by attaching an amino group to the resin component of the paint. There is. On the other hand, even with these water-soluble paints, the degree of ionization after being dissolved in water is weak. For this reason, in the case of aonine-type paints, for example, alkaline neutralizers such as triethylamine are mixed in, and
In the case of cationic paints, those mixed with an acidic neutralizer such as acetic acid are used to neutralize the paint and increase the degree of ionization in water.

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 amount 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 phenomena such as re-dissolution of the painted surface or 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, albeit 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 workpieces suspended from the line into the bathtub as well as when the workpieces to be coated are carried into and out of the bathtub. , 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/cm ² occurs, the water pressure will change by 2500Kg in the entire membrane, and a tension of approximately 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 were 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 electrode, causing polarization, and furthermore, phenomena such as air bubbles adhering due to water electrolysis occur. 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 this inconvenience, the inventor has already developed a diaphragm electrode device formed into a tubular shape (Utility Model Application No. 57-082002 (Utility Model Application No. 61-4531).
(U.S. Patent Application No. 499,818).

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,
Tubular electrodes are arranged at predetermined intervals on the inner surface of the diaphragm support member, and pure water flows from above to below the inner diameter of the tubular electrode, and further to the outside through the outer circumferential 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, the tightening work using the belt-like member is time-consuming, and the tightening strength varies depending on the operator, resulting in a disadvantage that the quality lacks uniformity.

[Purpose of the invention]

The present invention is directed to a method for fixing a diaphragm for electrodeposition coating, which improves the disadvantages of the conventional example and, in particular, reduces the labor required by assembly workers when attaching the diaphragm, and makes the quality of the entire device uniform. Its purpose is to provide.

[Means for solving problems]

Therefore, in the present invention, a diaphragm for electrodeposition coating is attached around the outer surface of a porous insulating member formed in a tubular shape and used with an electrode arranged inside, and then the outer surface of the diaphragm is passed through. A water-based cloth member is wound and fixed in a spiral shape as an outer cloth, and then the first and second main body insulating tubes are connected to both longitudinal ends of the outer cloth. The above object is achieved by arranging frames at intervals and filling and solidifying the potting material inside each frame.

[Effect]

By wrapping the diaphragm around a cylindrical diaphragm support member and then wrapping an outer cloth over it, it is possible to maintain diaphragms such as ion exchange membranes, which were traditionally considered weaker, for long periods of time without damaging them. Now available for use.

Furthermore, the ends of the diaphragm and the outer fabric are integrally fixed to the diaphragm support member together with the outer frame by a potting material (actually, the insulating tube connected to the diaphragm support member is also integrally fixed. ), it has sufficient durability against internal and external pressure.
This almost completely eliminates the inconvenience of the diaphragm detaching or peeling off from the diaphragm support member.

In addition, since the potting material can be uniformly filled inside the frame due to the action of the frame, the strength at the end of the diaphragm can be made uniform, making it easier to fill the potting material during assembly, and Therefore, productivity can be improved.

[First Embodiment] The first embodiment of the present invention will be described below with reference to FIGS. 1 to 3.
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 portion 2 includes first and second insulating tubes 5 and 6 coaxially arranged at a predetermined interval, and a relatively hard diaphragm support member 7 that connects each of these insulating tubes 5 and 6. , a diaphragm 9 wrapped around the outer periphery of the diaphragm support member 7 , and an outer cloth 8 further wrapped around the outer surface of the diaphragm 9 . This 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 by a non-conductive net member or a water-permeable porous member, and the first and second insulating tubes 5 and 6 are connected to the inner diameter side of both ends thereof. They are arranged so that they can be connected at.

Further, the diaphragm 9 is formed of an ion exchange membrane that is selectively permeable to ions attracted to the electrode section 3. In addition to the ion exchange membrane described above, the diaphragm 9 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.

Furthermore, the outer cloth 8 is spirally wound and added over the entire area of the outer peripheral surface of the diaphragm 9 as described above.

As shown in FIG. 1, first and second frames 20, 2 are arranged at a predetermined interval on the outer periphery of both ends of the diaphragm supporting member 7, around which the diaphragm 9 and the outer cloth 8 are wound.
1 is disposed, and at the same time, the potting material 11 is filled on the inner diameter side of the frames 20, 21, whereby each of the insulating tubes 5, 6, the diaphragm support member 7, the diaphragm 9, and the outer cloth 8 are connected. At the same time, it has a strongly integrated structure. In this case, the first frame 20 is formed into a cylindrical shape, and when filling the potting material 11, a ring member 12 is attached to the first frame in order to prevent the potting material 11 before solidification from flowing out. It is disposed within a frame 20 of.

The second frame 21 is formed into a cylindrical shape with a bottom, and is filled with the potting material 11 as described above with the diaphragm support member 7, the insulating tube 6, etc. inserted thereinto, and the entire body is filled with the potting material 11 as described above. 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,
In this embodiment, a hard vinyl chloride pipe is used. 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 section 3 includes a tubular electrode 30 made of stainless steel and formed into a tubular shape, a metal lid member 31 for locking the electrode hanging attached to the upper end of the tubular electrode 30 in FIG. It is composed of a power supply connection terminal 32 provided on a lid member 31 and a water supply section 33. Among them, the tubular electrode 30
is formed so that its outer diameter is 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 30 can be easily attached to and removed from the main body 2, and at the same time, a part of the water passage mechanism 4 is formed between the main body 2 and the tubular electrode 30. . Also,
The outer peripheral edge of the metal lid member 31 projects from the tubular electrode 30, so that the tubular electrode 30 is locked by the first insulating tube 5 as shown in FIG. It's becoming like that. Therefore, the electrode section 3 can be inserted into the main body section 2 from the outside very easily, and can also be removed to the outside very easily if necessary.

The water passage mechanism 4 is for discharging acetic acid etc. accumulated between the diaphragm 9 and the tubular electrode 30 to the outside, and specifically, the water passage mechanism 4 is for discharging to the outside acetic acid etc. accumulated between the diaphragm 9 and the tubular electrode 30.
It is composed of. 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. 8, and flows from below to the outer circumferential side of the tubular electrode 30. At the same time, the diaphragm 9 is moved upwardly on the outer peripheral side of the tubular electrode 30.
The liquid flows inside the body and is forcibly discharged from the discharge part 13 together with impurities to the outside.

On one frame 20 portion of the main body 2, there is a mounting fitting 1A for mounting on the bathtub during electrodeposition coating.
is wrapped. Further, the outer cloth 8 wrapped around the outer surface of the diaphragm 9 is not necessarily limited to a cloth-like material,
Other members may be substituted as long as they have 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 described in more detail.

First, the diaphragm 9 is wound around the outer periphery of the diaphragm support member 7, and the abutting ends of the diaphragm 9 are overlapped or abutted, so that the diaphragm 9 has a substantially circular cross-section as shown in FIG. stick. Next, the outer skin 8 is wound spirally around the outer surface of the diaphragm 9,
This completes the integration of the diaphragm support member 7 and the diaphragm 9. Next, the first and second insulating tubes 5 and 6 described above are fitted to both ends of the cylindrical diaphragm member thus formed as shown in FIG. On the outside, the first and second frames 20 and 21 are arranged at a predetermined interval 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.

The sealing 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. Material 1
After 1 is solidified, it may be removed.

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 the tubular electrode 30 and the diaphragm 9
Acetic acid accumulates between On the other hand, since pure water is forced to flow between the tubular electrode 30 and the diaphragm 9 as described above, 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, 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% neutralizer such as
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. Furthermore, in this embodiment, water-permeable outer cloth 8 is wound around the inner and outer surfaces of the diaphragm 9, so even if the tensile strength of the diaphragm 9 is extremely low, it is sufficient to withstand changes in internal pressure. It has the advantage of being able to withstand this.

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.

Therefore, when a plurality of diaphragm electrode devices 1 having the structure and function as described above are placed in an aqueous solution for electrodeposition and used, all the inconveniences caused by the conventional diaphragm method are eliminated. For example, to give an example of the durability of the diaphragm itself, it can sufficiently withstand external pressure because it is reinforced by the diaphragm support member 7, and the diaphragm itself can withstand internal pressure, for example, because it is reinforced by the diaphragm support member 7. If the inner diameter of the diaphragm electrode device 1 is 5 cm and four of these are used, the outer surface area of the entire diaphragm will increase compared to the case of the prior art described above, but the effect of the tubular configuration will work, and the internal pressure of the diaphragm electrode device 1 will change by 0.5 kg. / ^cm2
On the other hand, each diaphragm 9 has a diameter of approximately 1.25 mm along the circumference.
Only a tension of Kg/cm is applied. Therefore,
If a diaphragm with a tensile stress resistance of 2 kg/cm is used, as mentioned above, in the conventional technology, the tension change at the diaphragm attachment part will be about 8.5 kg/cm, and the diaphragm will immediately break from that attachment part. This embodiment has the advantage of being able to sufficiently withstand this even if the above-mentioned wrapped outer cloth 8 is not provided.

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 or elongated, for example, on the premise that the water passage mechanism 4 is secured. It may be plate-shaped.

[Second Embodiment] Next, a second embodiment will be described based on FIGS. 4 to 7.

This embodiment shows another example of the method for attaching the diaphragm 9 described above. That is, in the above-described first embodiment, the edges of the diaphragm 9 formed substantially in the direction of the center line of the diaphragm support member 7 are brought into contact with each other or partially overlapped to form the diaphragm 9 into a cylindrical shape. Later, it was fixedly attached to the diaphragm support member 7.
On the other hand, in this second embodiment, as shown in FIGS. 4 and 5, the winding edges 9A and 9B of the diaphragm 9 are
are stacked on top of each other on the back side, then folded,
It is characterized in that it is then attached to the diaphragm support member 7.

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. FIG. 7 is a cross-sectional view showing the winding state of the diaphragm 9 thus completed.

The other configurations are completely the same as the first embodiment described above.

Even in this case, in addition to having the same effect as the first embodiment described above, even if the diaphragm 9 made of a non-adhesive material (for example, a neutral film, etc.) is used, the polymerized portion of the diaphragm 9 There is an advantage that they can be firmly integrated by the tightening action of the outer cloth 8.

〔Effect of the invention〕

Since the present invention is configured and functions as described above,
This makes it possible to secure the diaphragm while sufficiently reinforcing it, thereby improving the durability of the diaphragm electrode device that is formed. Since it can be adhered almost uniformly across the body, it is possible to achieve uniform quality, and because there is no need to tighten the diaphragm as in the past, it is possible to improve productivity. A method for fixing a diaphragm for coating can be provided.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a diaphragm electrode device for electrodeposition coating formed by applying the first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the - line in FIG. 1, and FIG. 2 is an enlarged partial cross-sectional view of FIG. 2, FIGS. 4 to 6 are explanatory diagrams showing the winding state of the diaphragm according to the implementation of the second embodiment, and FIG. 7 is a diagram based on the second embodiment. FIG. 8 is an explanatory view showing the state in which the diaphragm electrode device for electrodeposition coating shown in FIG. 1 is used. 3... Electrode section, 5, 6... Main body insulating tube, 7...
...diaphragm support member as an insulating member, 8...outer cloth,
9...Diaphragm, 11...Potting material, 20,2
1...frame body, 30...electrode.

Claims (1)

[Claims] 1. A diaphragm for electrodeposition coating is attached around the outer surface of a porous insulating member formed in a tubular shape and used with an electrode arranged inside, and then a water-permeable cloth member is attached to the outer surface of the diaphragm. is spirally wound and fixed as an outer cloth, and then the first and second main body insulating tubes are connected to both ends in the longitudinal direction, and a frame is attached at a predetermined interval around the outer surface of each connected portion. A method for fixing a diaphragm for electrodeposition coating, comprising arranging the frames and filling the inside of each frame with a potting material and solidifying the potting material.