JPH05195293A - Electrodeposition coating device - Google Patents

Abstract

PURPOSE:To provide the electrodeposition coating device which enables the easy adjustment of the amt. of the acid in an electrodeposition coating bath while maintaining the quality of coating. CONSTITUTION:Diaphragm electrode devices 4, 3 having diaphragm parts for separating respective plural electrodes constituting a 2nd electrode section 2 from an aq. soln. are used as the respective electrodes of the electrodeposition coating device having a material 1 to be coated as the 1st electrode section disposed within the electrodeposition bath chamber 100 and the 2nd electrode section 2 consisting of the plural electrodes disposed in correspondence to this material 1. A part of the diaphragm electrode device 4 of these devices has the electrodes consisting of corrosion resistant materials and the 1st diaphragm parts 9 for blocking the greater part of the flow of the neutralizing agent in the aq. soln. to be sucked to these electrodes. The remaining diaphragm electrode device has the 2nd diaphragm parts for permeating and extracting the neutralizing agent. Water flow means which separately function are provided in the respective diaphragm electrode devices.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeposition coating apparatus,
More specifically, in an electrodeposition coating apparatus including an object to be coated forming a first electrode portion and a second electrode portion arranged corresponding to the object, a diaphragm electrode device as the second electrode portion. Relates to an electrodeposition coating device.

[0002]

2. Description of the Related Art Electrodeposition coatings are roughly classified into those using an anion type paint and those using a cation type paint. In both cases, the uniformity and adhesion of the coating film on the coated object Since it is excellent in properties and causes little pollution, it has been widely applied in recent years, for example, as an undercoat for metal coating or a one-coat finish, especially for automatic coating treatment of automobile bodies.

Among the paints used for such electrodeposition coating, the above-mentioned anionic paint has, for example, a molecular weight of 2
000 resin to which a carboxyl group is attached to make it water-soluble is used. Further, as the above-mentioned KAOTIN-type paint, water-soluble one to which an amino group is attached to the resin component of the paint is used. There is. On the other hand, even these water-soluble paints have a weak ionization degree after being dissolved in water. For this reason, at present, in the case of aonine type paint, an alkaline neutralizing agent such as triethylamine is mixed, and in the case of a kaolin type paint, an acidic neutralizing agent such as acetic acid is mixed and neutralized in water. It is used for increasing the ionization degree of.

As described above, a neutralizing agent for increasing the degree of ionization is mixed according to the properties of the resin component of each paint.
On the other hand, when the electrodeposition treatment of the object to be coated progresses and the resin component of the coating material in the solution decreases, the coating material must be sequentially replenished from the outside, so that the above-mentioned solution contains amine or acetic acid as a neutralizing agent. A phenomenon such as continuous accumulation and redissolution of the coated surface or generation of pinholes occurs, and the efficiency of electrodeposition coating is significantly impaired.

For this reason, in recent years, for example, as shown in Japanese Patent Publication No. 45-22231, the object to be coated as one electrode and the aqueous solution are separated from the other electrode by an ion exchange membrane or the like. The so-called pH control is carried out so that amine or acetic acid is permeated and extracted from the aqueous solution by the ion exchange membrane or the like to prevent an increase in the neutralizing agent in the aqueous solution.

Here, the cationic electrodeposition using the cationic coating material will be described.

Conventionally, in cation electrodeposition, an anion exchange membrane has been used as a diaphragm. This anion exchange membrane usually has a value of 8 to 10 × 10 ⁻⁶ [mol / coulomb] as electric efficiency of acid removal (coulomb removal rate of acid). As the acid (neutralizing agent) added to the electrodeposition aqueous solution (ED bath paint) in the electrodeposition bath layer, only the amount A contained in the paint supplied to the electrodeposition bath layer is used.

On the other hand, the acid carried out from the ED bath paint to the outside is carried out by being contained in the coating film of 10 to 20% of A carried out in the UF filtrate used as a washing liquid after electrodeposition coating. 5-10% of A The total amount B of 70-80% of A removed by the diaphragm electrode. It is ideal that the amount A and the amount B are equal, but since adjustment is difficult, in general, B> A is generally set to supply the acid which is in a shortage from the outside.

For this reason, when all of the electrodes provided in the electrodeposition bath layer are diaphragm electrodes for acid extraction, the acid is excessively removed excessively, causing a deficiency of the acid as a neutralizing agent. However, it becomes troublesome to manage the neutralizing agent in the ED bath paint, such as periodical supply of acid from the outside, and waste of the acid is also consumed. For this reason, today, some of the electrodes are composed of so-called bare electrodes having no diaphragm to balance the acid removal.

As described above, when the removal rate is 8 to 10 × 10 ^-6 [mol / coulomb], the acid is excessively removed, and
At 6 × 10 ^-6 [mol / coulomb], a neutral film having such an acid removal rate may be used in some cases because the balance of the acid removal is approximately ideal.

[0011]

However, the method of partially using the bare electrode of the above-mentioned conventional example has the following serious disadvantages in meeting the recent demand for finish of high quality coating. .. That is, sludge containing an inorganic pigment as a main component that deposits on the surface of the bare electrode becomes a problem, and a component that promotes electrolytic corrosion of the electrode (usually SUS316 is often used) among useful components in the coating material. Often included, energization causes severe electrolytic corrosion. Usually S
The electrolytic corrosion rate of US316 is 2-3 × 1 with respect to the flowing current.
Although it is about 0 ⁻⁶ [gram / coulomb], it may reach 100 to 150 × 10 ⁻⁶ [gram / coulomb] in the above case.

In this way, heavy metal ions (iron, chromium, nickel, etc.) eluted from the electrode due to electrolytic corrosion are mixed in the paint, and the surface of the paint is roughened, rust-preventive power is lowered, and problems such as coloring problems due to heavy metals are caused. It was happening.

Even when the neutral film of the above-mentioned conventional example is used, the same problem occurs because the neutral film allows the components for promoting electrolytic corrosion, heavy metal ions and the like to pass through.

[0014]

OBJECTS OF THE INVENTION The object of the present invention is to improve the inconveniences of the conventional examples, and in particular, to enable the amount of acid in the electrodeposition coating to be easily adjusted while maintaining the quality of the coating. To provide a device.

[0015]

Therefore, in the present invention, an object to be coated as a first electrode portion disposed in an electrodeposition bath,
A second electrode portion composed of a plurality of electrodes arranged corresponding to the object to be coated, and between the object to be coated and the second electrode portion,
An electric current is passed through an aqueous solution of the coating film-forming substance contained in the electrodeposition bath, so that the coating film-forming substance is electrodeposited on the article to be coated. Here, a diaphragm electrode device having a diaphragm part for separating each electrode from an aqueous solution is used as each electrode forming the second electrode part, and some of the diaphragm electrode devices are electrodes made of a corrosion resistant member. And a first diaphragm portion that blocks most of the flow of ions in the neutralizing agent in the aqueous solution that is sucked into the electrode, and a second diaphragm electrode device that permeates and extracts the neutralizing agent. It is equipped with a diaphragm part. Further, a water passage means for forcibly circulating water from one side to the other side is provided between the first diaphragm portion and the electrode in some of the diaphragm electrode devices. Further, between the second diaphragm portion and the electrode in each of the remaining diaphragm electrode devices, another water passage means having the same function as the water passage means,
It is configured to be installed separately from the water passage means. This aims to achieve the above-mentioned object.

[0016]

The operation of the electrodeposition coating apparatus of the present invention for cationic electrodeposition coating will be described.

First, when a DC voltage is applied with the object to be coated as the negative electrode and each diaphragm electrode device constituting the second electrode portion as the positive electrode, the electrode coating is immediately started in the same manner as usual, and the electrodeposition coating aqueous solution is used. The coating resin components and pigment colloid molecules that have a positive electric charge move toward the negative electrode coating object and adhere to the surface of the coating object to discharge, then the coating material solidifies and forms a coating film. To be done.

Acetic acid having a negative charge is accumulated in the aqueous solution, and the acetic acid starts moving toward the electrodes of each diaphragm electrode device at the same time when the above-mentioned electrodeposition coating is started. The flow of the neutralizing agent acid (anion) in the aqueous solution is largely blocked by this cation exchange membrane due to the action of the cation exchange membrane as the first diaphragm part equipped in some diaphragm electrode devices. As a result, the acid cannot reach the electrode side, and the acid accumulates in the aqueous solution for electrodeposition. However,
Since this cation exchange membrane does not completely block acetic acid, part of it reaches the electrode and is discharged. In this case, since the electrode made of the corrosion resistant member is used as the anode, the cations hardly elute from the anode.

On the other hand, since the remaining diaphragm electrode device is provided with the anion membrane as the second diaphragm part which allows acetic acid molecules having a negative charge to easily pass therethrough, it is attracted to the electrode of the diaphragm electrode device having a positive potential. The acid molecules easily pass through the anion exchange membrane along the lines of electron force, reach the electrode, and are discharged. As a result, acid is accumulated between the electrode and the anion exchange membrane, but this acid is carried out to the outside by the water-passing means. Therefore, the acid is not excessively accumulated in the aqueous solution. At the same time, the outflow of the heavy metal ions eluted from the electrode to the aqueous solution for electrodeposition is effectively blocked by the action of the anion exchange membrane.

[0020]

[First Embodiment] A first embodiment of the present invention will be described below with reference to FIGS.

This example shows the case where the present invention is applied to a cationic electrodeposition coating apparatus using a cationic coating material.

The embodiment shown in FIG. 1 is an electrodeposition bath 10
An object to be coated 1 serving as a first electrode portion disposed in the interior of the substrate 0 and a second electrode portion 2 including a plurality of electrode devices disposed corresponding to the object to be coated 1 are provided. One of the neutralizing agent extraction type diaphragm electrode devices 3, which is a diaphragm electrode device having a second diaphragm part as each electrode constituting the second electrode part 2.
.. and the other neutralizing agent blocking type diaphragm electrode device 4, 4, ... As a diaphragm electrode device having the first diaphragm portion. These diaphragm electrode devices 3 and 4 are alternately arranged.

One diaphragm electrode device 3 of the neutralizing agent extraction type
As such, one having a diaphragm part for permeating and extracting the neutralizing agent in the aqueous solution for electrodeposition coating (an aqueous solution of cationic paint) W contained in the electrodeposition bath 100 is used. As the other membrane electrode device 4 of the neutralizing agent blocking type, a tubular electrode made of a corrosion resistant member (for example, a titanium alloy coated with iridium oxide or the like, or a good quality material such as a ferrite material is used) is used. What has a first diaphragm part that blocks most of the flow of ions in the neutralizing agent in the aqueous solution W sucked by the tubular electrode is used.

This will be described in more detail. The other diaphragm electrode device 4 has a main body portion 11 and an electrode portion 1 as shown in FIG.
2 and a water passage mechanism 14 that is an essential part of the water passage means set between them.

The main body portion 11 includes first and second insulating pipes 15 and 16 coaxially arranged at a predetermined interval, and a relatively hard diaphragm support for connecting the insulating pipes 15 and 16 to each other. A member 17, a cation exchange membrane 9 as a first diaphragm portion wound around the outer periphery of the diaphragm support member 17, and an outer cloth 18 further wound around the outer surface of the cation exchange membrane 9. There is. The outer cloth 18 is made of, for example, a chemical fiber and has water permeability that is sufficiently durable against tension.

The diaphragm supporting member 17 is formed in a relatively long tubular shape by a non-conductive mesh member or a water-permeable porous member, and the first and second insulating pipes 15 and 16 are provided on the inner diameter side of both ends thereof. Are arranged so as to be connected.

The cation exchange membrane 9 is formed in a cylindrical shape as shown in FIG. 3, and is wound around the outer periphery of the diaphragm supporting member 17 as described later.

Further, since the cation exchange membrane 9 is wound around the diaphragm supporting member 17, the mechanical strength against the external pressure is remarkably enhanced. Further, the outer cloth 18 is spirally wound around the outer peripheral surface of the cation exchange membrane 9 as described above, whereby sufficient pressure resistance against internal pressure is added. There is.

As shown in FIG. 2, the cation exchange membrane 9 and the outer cloth 18 are wound around the outer peripheral sides of both ends of the diaphragm supporting member 17, and the first and second frame members 20,
21 is provided, and at the same time, the potting material 41 is filled on the inner diameter side of the frame bodies 20, 21, so that the insulating tubes 15, 16 and the diaphragm support member 17, the cation exchange membrane 9, and the outer cloth 18 are simultaneously formed. Moreover, it has a solidly integrated structure. In this case, the first frame body 20 is formed in a tubular shape, and the ring member 22 is provided with a first ring member 22 in order to prevent the potting material 41 before solidification from flowing out when the potting material 41 is filled. It is arranged in the frame body 20.

The second frame body 21 is formed in a bottomed tubular shape, and is filled with the potting material 41 as described above with the diaphragm supporting member 17 and the insulating tube 16 inserted therein. The entire structure is integrally fixed at the same time.

As the potting material 41, an epoxy resin is used in this embodiment, but a urethane resin, a phenol resin or the like may be used.

As the first and second insulating pipes 15 and 16, hard vinyl chloride pipes are used in this embodiment. Of these, the first insulating pipe 5 is provided with a drainage portion 13 as shown in FIG. 2, and a cap 24 is detachably attached to the upper end portion thereof. Reference numeral 15A indicates a spacer fixed to the inner diameter side of the upper end of the insulating tube 15.

On the other hand, the electrode portion 12 is made of titanium and has a tubular shape. The tubular electrode 30 has a surface coated with iridium oxide and the like, and the electrode hanging down the upper end portion of the tubular electrode 30 in FIG. Metal lid member 3 for locking
1, and a power supply connection terminal 32 provided on the lid member 31.
And a water supply unit 33. Of these, the tubular electrode 30 is formed such that the outer diameter thereof is smaller than the inner diameters of the first and second insulating tubes 15 and 16 of the main body portion 11 described above. Therefore, the tubular electrode 30 can be easily attached to and detached from the main body portion 11, and at the same time, a part of the water passage mechanism 14 is formed between the main body portion 11 and the tubular electrode 30. Further, the metal lid member 31
Has an outer peripheral edge protruding from the tubular electrode 30,
As a result, the tubular electrode 30 is locked by the first insulating tube 15 as shown in FIG. Therefore, the electrode portion 12 is very easily inserted and arranged in the main body portion 11 from the outside, and can be detached to the outside very easily if necessary.

The water flow mechanism 14 is for discharging acetic acid or the like accumulated between the cation exchange membrane 9 and the tubular electrode 30 to the outside. Specifically, the water flow mechanism 14 includes the electrode portion 12 and the main body portion 11 described above. It is composed by. That is, the water flowing in from the water supply part 33 of the electrode part 12 flows down in the tubular electrode 30 as shown by the arrow in FIG. 3, and flows from the lower side to the outer peripheral side of the tubular electrode 30, At the same time, it rises on the outer peripheral side of the tubular electrode 30 and flows inside the cation exchange membrane 9 and is forcibly discharged together with impurities from the discharge part 13 to the outside.

On one frame 20 portion of the main body portion 11, a mounting metal fitting 11A for mounting on the bathtub during electrodeposition coating is wound. The outer cloth 18 wound around the outer surface of the cation exchange membrane 9 is not necessarily limited to the cloth-like one, and may be replaced with another member as long as it has the same reinforcing function and water permeability. .. Further, the cation exchange membrane 9 may be wound in a spiral shape, or may be attached in the form of a circular slice on the assumption that the joint portion is waterproof.

Here, the method of fixing the cation exchange membrane 9 forming the main part of the main body 11 will be described in more detail.

First, the cation exchange membrane 9 is wound around the outer periphery of the diaphragm supporting member 17, and the contact end portions thereof are overlapped with each other or the contact end edges thereof are abutted to each other, so that a substantially cross section is obtained as shown in FIG. Sticks in a circular shape. Subsequently, the outer cloth 18 is spirally wound around the outer surface of the cation exchange membrane 9, whereby the integration of the membrane supporting member 17 and the cation exchange membrane 9 is completed. Next, the first and second insulating pipes 15 and 16 described above are attached to both ends of the cylindrical diaphragm member thus formed.
2, and at the same time, the eleventh and second frame bodies 20 and 21 are arranged outside the respective fitting portions at a predetermined interval as described above. And each frame 2
The potting material 41 is filled in each of 0 and 21 to be solidified, whereby the integration of the main body 11 is completed.

The seal member 22 disposed inside the lower end portion of the first frame body 20 in FIG. 2 is for preventing the potting material 41 before solidification from flowing out, as described above. After the potting material 41 is solidified, it may be removed.

Further, one diaphragm electrode device 3 has substantially the same structure as the other diaphragm electrode device 4 described above.
Instead of the cation exchange membrane 9, an anion exchange membrane as the second diaphragm is used, and in place of the tubular electrode 30, a normal tubular electrode made of stainless steel is used. Other configurations are the same as those of the diaphragm electrode device 4 described above.

Next, the overall operation of this embodiment will be described.

First, the object to be coated 1 is used as a negative electrode, and one diaphragm electrode device 3, 3, ... And the other diaphragm electrode device 4,
When a DC voltage is applied with each of the tubular electrodes 4 and ... as a positive electrode, electrode coating is immediately started as usual, and the coating resin component and pigment colloid molecules having a positive charge in the aqueous solution are applied to the negative electrode article 1 to be coated. After moving toward and adhering to the surface of the article to be discharged and discharging, the solid matter of the coating material agglomerates to form a coating film.

On the other hand, acetic acid having a negative charge is accumulated in the aqueous solution. This acetic acid is applied to each diaphragm electrode device 3, 3, ..., 4, 4 at the same time when the above-mentioned electrodeposition coating is started.
.. starts moving toward each tubular electrode. Here, since each of the diaphragm electrode devices 3 on one side uses an anion membrane that allows acetic acid molecules having a negative charge to easily pass therethrough, acetic acid molecules attracted to the tubular electrode of the diaphragm electrode device 3 of positive potential are , Easily pass through the anion exchange membrane along the line of electron force, reach the tubular electrode from around the tubular electrode, and are discharged. In this case, since the discharged neutralizing agent is ionized almost entirely at a low concentration, the neutralizing agent is attracted to the anode during energization, and therefore is accumulated between the tubular electrode and the anion exchange membrane.

By the way, since pure water, for example, is forced to flow between the tubular electrode and the anion exchange membrane as described above, the acetic acid accumulated is continuously discharged together with pure water to the outside. It

On the other hand, in each of the other diaphragm electrode devices 4, since the cation exchange membrane 9 is used, the coulomb removal efficiency of the acid is extremely low at 1 × 10 ⁻⁶ [gram / coulomb] or less, and the aqueous solution is used. The flow of acetic acid (anion) as a neutralizing agent in W is mostly blocked by the cation exchange membrane 9 and cannot reach the electrode 30 side, and acetic acid is accumulated in the aqueous solution W for electrodeposition. .. In this case, the negative (-) charge cannot be transferred from the aqueous solution W side to the tubular electrode 30 side, but is generated by the ionization of the acid in the polar liquid that is previously filled between the tubular electrode 30 and the cation exchange membrane 9. Further, since hydrogen ions [H ⁺ ] are attracted to the article to be coated 1 and pass through the cation exchange membrane 9, the hydrogen ions carry a positive [+] charge, so that a current flows. However, this cation exchange membrane 9 does not completely block acetic acid, so that part of it reaches the electrode 30 and is discharged. Similar to the case described above, acetic acid is accumulated between the tubular electrode 30 and the diaphragm portion 9, and the accumulated acetic acid is continuously discharged to the outside together with pure water.

Since the tubular electrode 30 of the other diaphragm electrode device 4 is made of titanium and the surface of which is coated with iridium oxide, heavy metal ions hardly elute from the tubular electrode 30.

As described above, according to the first embodiment, the acid removal rate is suppressed, the other diaphragm electrode device 4 in which the electrode hardly elutes, and the acid can be effectively removed. Since one diaphragm electrode device 3 having an anion membrane that blocks the flow of cations due to the elution of the electrode is used, it is possible to prevent excessive removal of the acid, which is a neutralizing agent, which has been a problem in the past. There is an advantage that it is possible to almost completely prevent heavy metal ions from being mixed into the paint component (ED bath paint) in the aqueous solution for electrodeposition due to elution of the electrode. Further, there is also an advantage that the acid removal rate can be set to a desired value by appropriately combining the one diaphragm electrode device 3 and the other diaphragm electrode device 4.

Here, one diaphragm electrode device 3, 3, ... And the other diaphragm electrode device 4, 4, ... In the above-mentioned embodiment.
As shown in FIG. 5, the other diaphragm electrode devices 4, 4, ... May be arranged in the tank portion, and the diaphragm electrode devices 3, 3 ,.

In this way, it is possible to reduce the number of installation of the other diaphragm electrode device 4, 4, ..., Which uses a corrosion-resistant member and has a relatively high unit price, and in this respect, the capital investment of the entire device is reduced. There is an advantage that you can. That is, since the coating film is not formed on the article to be coated 1 on the entry side, the value of energizing current is large. Therefore, the amount of acid collected on the inlet side is significantly larger than that on the outlet side. By adjusting the amount of acid extracted at a location where the amount of acid collected is large, the number of other diaphragm electrode devices 4 having a high unit price can be reduced.
This is convenient because the capital investment of the entire electrodeposition coating system can be effectively reduced.

When the polar liquid circulation system of the other diaphragm electrode device 4 is separated from the polar liquid circulation system of the one diaphragm electrode device 3,
Since the polar liquid of one diaphragm electrode device 3 is not supplied to the other diaphragm electrode device 4, it is possible to almost completely prevent the heavy metal from mixing into the bath paint.

In this case, in each of the diaphragm electrode devices 3 on the one hand, a relatively large amount of pure water or the like is required to carry out because a relatively large amount of acid is continuously accumulated, but on the other hand, the diaphragm electrode device 4 on the other hand.
However, since the accumulation of acid and heavy metal ions is small, the amount of pure water or the like used for carrying them out is small. Therefore, by separately setting the circulation systems of the one diaphragm electrode device 3 and the other diaphragm electrode device, consumption of the amount of pure water can be effectively suppressed, and further, the other diaphragm electrode device 4 can be suppressed. It is possible to effectively eliminate clogging of the cation exchange membrane 9 due to heavy metal substances, and at the same time, it is possible to downsize the equipment of the circulation system of the other diaphragm electrode device, which results in the overall electrodeposition coating system. There is an advantage that the capital investment can be reduced more effectively.

[0051]

[Second Embodiment] Next, a second embodiment will be described with reference to FIG.

Here, the same reference numerals are used for the same constituent members as those in the first embodiment described above.

In this embodiment, the voltage adjusting means 40 for adjusting the voltage applied between the one diaphragm electrode device 3, 3, ... And the article to be coated 1 in the first embodiment is provided. It is characterized by the fact that The other structure is the same as that of the first embodiment described above.

Even with this structure, the same action and effect as those of the first embodiment can be obtained, and the voltage adjusting means 40 acts to apply the voltage between each diaphragm electrode device 3 and the article 1 to be coated. Since the applied voltage can be adjusted, there is an advantage that the amount of acid in the electrodeposition bath 100 can be adjusted more easily.

[0055]

Since the present invention is constructed and functions as described above, when it is used for cationic electrodeposition coating as in the above-mentioned embodiment, for example, a part of the diaphragm electrode having the first diaphragm portion is used. By the action of the device, it is possible to suppress the excessive removal of the acid which is the neutralizing agent in the aqueous solution, and at the same time, the action of the remaining diaphragm electrode device provided with the second diaphragm part permeates and extracts the acid in the aqueous solution. It is possible to effectively prevent the heavy metal ions and the like from flowing out into the aqueous solution because the above-mentioned part of the diaphragm electrode device does not elute because the electrode is made of a corrosion resistant member. Therefore, it is possible to easily adjust the amount of the acid as the neutralizing agent in the electrodeposition bath while maintaining the quality of the electrodeposition coating for a long period of time. The water passage means on the side of the diaphragm electrode device and the second diaphragm Since the remaining water-passing means on the side of the diaphragm electrode device are installed independently of each other, not only can the heavy metal be effectively carried out from the bathtub, but also the side of the diaphragm electrode device provided with the second diaphragm. It is possible to reduce the use of pure water in the water passage means of the above, which makes it possible to effectively reduce the downsizing of the water passage means and the capital investment for this facility. A dressing / coating device can be provided.

Further, in the above embodiment, the case where the tubular electrodes are used as the respective electrodes forming the second electrode portion has been illustrated, but the present invention is not limited to this, and a box-shaped electrode or the like is used. However, the same effect can be obtained in this case as well.

[Brief description of drawings]

FIG. 1 (1) is an explanatory view showing the arrangement of each diaphragm electrode device according to the first embodiment of the present invention as viewed from above. (2) is an explanatory view showing the configuration of the first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a specific configuration of a part of the diaphragm electrode device including the first diaphragm part in FIG.

FIG. 3 is an explanatory view showing a water distribution path in the apparatus of FIG.

FIG. 4 is a sectional view taken along line IV-IV of FIG.

5 is an explanatory view showing another arrangement example of each diaphragm electrode device of FIG. 1. FIG.

FIG. 6 is an explanatory diagram showing a configuration of a second exemplary embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Coated object as a 1st electrode 2 2nd electrode 3 Other diaphragm electrode device 4 One diaphragm electrode device 9 Cation exchange membrane as a 1st diaphragm part 14 Water-passing mechanism which forms the principal part of a water-passing means. 30 Tubular Electrode as Electrode Made of Corrosion-Resistant Member 100 Electrodeposition Bath W Aqueous Solution of Cationic Paint as Aqueous Solution of Coating Film Forming Substance

Claims (1)

[Claims] 1. An article to be coated as a first electrode section disposed in an electrodeposition bath, and a second electrode section composed of a plurality of electrodes disposed corresponding to the article to be coated. The electrodeposition of the coating film-forming substance on the coating object is performed by passing electricity between the coating object and the second electrode section through an aqueous solution of the coating film-forming substance contained in the electrodeposition bath. In the electrodeposition coating apparatus, a diaphragm electrode device having a diaphragm part separating each electrode from the aqueous solution is used as each of the plurality of electrodes forming the second electrode part, and a part of the diaphragm electrode device is used. Has an electrode composed of a corrosion resistant member, and a first diaphragm portion that blocks most of the flow of ions in the neutralizing agent in the aqueous solution attracted to the electrode, and the remaining diaphragm electrode device is A second diaphragm part for permeating and extracting the neutralizing agent is provided, and Water passage means for forcibly circulating water from one side to the other side is provided between the first diaphragm portion and the electrode, and between the second diaphragm portion and the electrode in each of the remaining diaphragm electrode devices. An electro-deposition coating apparatus characterized in that another water-passing means having the same function as the water-passing means is provided separately from the water-passing means.