JP2729277B2 - Diaphragm electrode device for electrodeposition coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a diaphragm electrode device for electrodeposition coating, and more specifically, to an object to be coated which forms one electrode and a correspondingly disposed object. The present invention relates to a diaphragm electrode device for electrodeposition coating used as the other electrode in electrodeposition coating with the other electrode.

[Conventional technology]

Electrodeposition coating is roughly classified into those using an anionic paint and those using a cationic paint.Each of them has excellent uniformity and adhesion of the coating film on the object to be coated. In recent years, it has been widely applied to, for example, automatic coating of automobile bodies and the like, which is particularly suitable for undercoating or one-coat finishing of metal coating, because of low pollution.

Among the paints used for such electrodeposition coating, as the aforementioned anionic paint, for example, a water-soluble resin obtained by attaching a carboxyl group to a resin having a molecular weight of 2,000 is used, and as the cationic paint, What has been used is one in which an amino group is attached to a resin component of the paint to make it water-soluble. On the other hand, even with these water-soluble paints, the degree of ionization after dissolving in water is weak. For this reason, at present, in the case of an anionic paint, an alkaline neutralizer such as triethylamine is mixed, and in the case of a cationic paint, an acidic neutralizer such as acetic acid is mixed and neutralized in water. Which increase the degree of ionization is used.

As described above, the neutralizing agent for increasing the degree of ionization is mixed according to the properties of the resin component of each paint, but the electrodeposition treatment of the object to be coated proceeds, and the resin component of the paint in the solution is reduced. When the amount decreases, the paint must be sequentially replenished from the outside. Therefore, amine or acetic acid as a neutralizing agent is continuously accumulated in the above-mentioned solution, and phenomena such as re-dissolution of the coated surface or generation of pinholes. And the efficiency of the electrodeposition coating is significantly impaired.

For this reason, in recent years, for example, Japanese Patent Publication No. 45-22231
As seen in the publication, while separating the other electrode from the object to be coated and the aqueous solution as one electrode by an ion exchange membrane or the like, the amine or acetic acid is permeated and extracted from the aqueous solution by the ion exchange membrane or the like. Thus, so-called pH control of preventing an increase in the neutralizing agent in the aqueous solution is performed, and the effect is achieved.

Here, the cationic electrodeposition using the cationic paint will be described.

Conventionally, in cation electrodeposition, an anion exchange membrane has been used as a diaphragm. This anion exchange membrane
Usually, the electrical efficiency of acid removal (coulomb removal rate of acid)
It has a value of 8 to 10 × 10 ⁻⁶ [mol / Coulomb].

The acid (neutralizing agent) added to the aqueous solution for electrodeposition (ED bath paint) in the electrodeposition bath layer is only the amount A contained in the paint supplied to the electrodeposition bath layer.

On the other hand, the acid taken out from the ED bath paint to the outside is 10 to 20% of A taken out and contained in the UF filtrate used as a washing solution after electrodeposition coating. 1010 [%] The total amount B of 70 to 80 [%] of A removed by the diaphragm electrode.

Although it is ideal that the amount A and the amount B are equal, it is difficult to adjust the amount. Therefore, in general, B> A is often supplied from the outside to make the amount of acid insufficient.

For this reason, when all of the electrodes provided in the electrodeposition bath layer are used as diaphragm electrodes, the removal of the acid becomes excessive and causes a deficiency of the acid as a neutralizing agent, and the acid is periodically removed from the outside. For example, it becomes necessary to replenish the acid, and the management of the neutralizing agent in the ED bath paint becomes troublesome, and the acid is wasted. For this reason,
Today, some of the electrodes are made up of so-called bare light bulbs without a diaphragm to balance acid removal.

As mentioned above, removal of the acid becomes excessive in removal rate 8 to 10 × 10 ^-6 [mol / Coulomb], and the balance of the 5 to 6 × 10 ^-6 [mol / Coulomb] In approximately ideal acid removal Therefore, a neutral film having such an acid removal rate may be used.

In addition, in cation electrodeposition, it is also possible to use a cation exchange membrane for a part of the diaphragm electrode.

[Problems to be solved by the invention]

However, the above-described method of partially using the bare electrode has the following serious inconveniences in meeting the recent demand for high-quality coating.

That is, sludge mainly composed of an inorganic pigment deposited on the surface of the bare electrode becomes a problem, and among the useful components in the paint, a component that promotes electrolytic corrosion of the electrode (usually SUS316 is often used). Is often included, causing severe electrolytic corrosion when energized. Usually, the electrolytic corrosion rate of SUS316 is about 2 to 3 × 10 ⁻⁶ [gram / coulomb] with respect to the flowing current, but in the above case, it is also 100 to 150 × 10 ⁻⁶ [gram / coulomb]. May reach.

In this way, heavy metal ions (iron, chromium, nickel, etc.) eluted from the poles due to electrolytic corrosion are mixed into the paint,
Obstacles such as roughening of the painted surface, reduced rust prevention, and coloring by heavy metals have occurred.

Further, even in the case of using the above-described conventional neutral film, the neutral film has a similar disadvantage because the neutral film allows components that promote electrolytic corrosion, heavy metal ions, and the like to pass through.

Further, when the above-mentioned conventional cation exchange membrane is used, the efficiency of acid cloning is very low at 1 × 10 ⁻⁶ [gram / coulomb] or less. Although excessive removal of the acid can be prevented by using, the heavy metal ions generated by the elution of the above-mentioned electrode are passed, so that the electric efficiency reaches 4 to 15 × 10 ⁻⁶ [gram / coulomb]. In other words, this means that the use of the cation exchange membrane causes a disadvantage that most of the heavy metal ions eluted from the poles are mixed into the paint.

[Object of the invention]

An object of the present invention is to improve the disadvantages of the conventional example, and particularly, without releasing heavy metals and the like in bath paints.
An object of the present invention is to provide a diaphragm electrode device for electrodeposition coating capable of effectively reducing the acid removal efficiency.

[Means for solving the problem]

Therefore, in the present invention, the other electrode provided corresponding to the object to be coated as one electrode, and a diaphragm for separating the other electrode from the one electrode and the paint component of the aqueous solution for electrodeposition coating. In the diaphragm electrode device for electrodeposition coating, comprising: the diaphragm, a cation exchange membrane disposed on the object side or the other electrode side, and the other electrode side facing the cation exchange membrane Alternatively, a configuration is adopted in which a double structure composed of an anion exchange membrane provided on the side of the article to be coated is adopted, thereby achieving the object described above.

[Action]

The case where the diaphragm electrode device of the present invention is used for cationic electrodeposition coating will be described.

First, an object to be coated (not shown) and a diaphragm electrode device are disposed in an aqueous solution of a cationic paint which is neutralized with acetic acid. Is applied. In this case, a membrane electrode device equipped with a cation exchange membrane on the paint side and an anion exchange membrane on the electrode side is used. In the cation exchange membrane, the cations moving from the polar solution side are blocked by the anion membrane on the electrode side, and the charge and carriers passing through the cation membrane are depleted. In the anion exchange membrane, the acid is blocked by the cation exchange membrane on the paint side and the carrier of the anion is depleted, so that the charge is carried by the passage of the cation. It tends to be. In this way, a current flows between the two exchange membranes, so that electrode coating is immediately started, and a coating resin component having a positive charge and a colloid molecule of a pigment move toward an object to be coated on the negative electrode in an aqueous solution,
After adhering to the surface of the article and discharging, the solids of the paint aggregate to form a coating film.

On the other hand, acetic acid having a negative charge in the aqueous solution starts moving toward the electrode of the diaphragm electrode device simultaneously with the start of the electrodeposition coating, as described above. At this time, the flow of acetic acid is mostly blocked by the cation exchange membrane on the paint side. On the other hand, the action of the anion exchange membrane on the electrode side prevents heavy metal ions flowing out of the electrode from flowing out to the electrodeposition aqueous solution side.

First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

The diaphragm electrode device 1 of the embodiment shown in FIG.
As shown in FIG. 3, it is disposed in an aqueous solution W for electrodeposition coating corresponding to a coating object 100 as one electrode and used as the other electrode. Here, an aqueous solution of a cationic paint is used as the aqueous solution W for electrodeposition coating.

The diaphragm electrode device 1 includes a main body 2, an electrode 3 as the other electrode, and a water flow mechanism 4 set between the two.

The main body 2 includes first and second insulating tubes 5 and 6 arranged coaxially at predetermined intervals, and each of these insulating tubes 5 and 6.
, A relatively hard diaphragm supporting member 7 that connects the two, a diaphragm 9 wound around the outer periphery of the diaphragm supporting member 7, and an outer cloth 8 further wound around the outer surface of the diaphragm 9.
The outer cloth 8 is made of, for example, chemical fiber and has water permeability that is sufficiently durable against tension.

The diaphragm supporting member 7 is formed in a relatively long tubular shape by a non-conductive net-like member or a water-permeable porous member, and the first and second insulating tubes 5 and 6 are provided at inner ends of both ends thereof. It is arranged to be connected.

As shown in FIG. 1, each of the diaphragms 9 is formed in a cylindrical shape, and is provided with a cation exchange membrane 9a disposed on the outside (paint side) and an inside facing the cation exchange membrane 9a. And an anion exchange membrane 9b disposed on the side of the electrode section 3 of the above.

More specifically, the outer cation exchange membrane 9a and the inner anion exchange membrane 9b are wound around the outer periphery of the membrane support member 7 with both ends integrally fixed as described later. ing. In fact, these cation exchange membranes
Since the surfaces of 9a and the anion exchange membrane 9b have some irregularities, a certain gap is formed between the opposing portions thereof. For this reason,
As shown in FIG. 1, small holes 9c and 9d are provided at the upper and lower ends of the inner anion exchange membrane 9b, respectively.
Electrolyte is always through cation exchange membrane 9a and anion exchange membrane
9b so as to prevent the generation of voids that hinder energization.

The reason why the diaphragm 9 has a double structure is that the cation exchange membrane 9a is disposed on the paint side, and the flow of the acid as the neutralizing agent in the ED bath paint is prevented by the cation exchange membrane 9a. In addition, an anion exchange membrane 9b is provided on the inner side close to the electrode 30 side, and positive (+) heavy metal ions eluted from the electrode 30 are blocked by the anion exchange membrane 9b. That is, the acid permeability of the cation exchange membrane is 1 × 10 ⁻⁶ [mol / Coulomb] or less, and 8 to 10 × when the anion exchange membrane is used.
It is expected to be very small compared to 10 ^-6 [mol / coulomb], and the permeation amount of heavy metal will be 4 to 4 when using a cation exchange membrane under the usual electrodeposition coating line operating conditions.
15 × 10 ⁻⁶ [gram / coulomb], whereas in the case of the anion exchange membrane, 0.025 × 10 ⁻⁶ [gram / coulomb]
This is because it has an extremely low value.

Here, it is generally considered that no current flows if an acid, that is, a negative (-) ion is blocked by the cation exchange membrane 9a and a positive ion is blocked by the anion exchange membrane 9b. In practice, the current flows sufficiently for a reason.

Part of the water at the interface between the cation exchange membrane 9a and the anion exchange membrane 9b is ionized into [H ⁺ ] and [OH ⁻ ]. In the case of neutral purity, the degree of ionization is about 10 ⁻⁷ [mol / liter] for both [H ⁺ ] and [OH ⁻ ], but at the interface between the anion exchange membrane 9b and the cation exchange membrane 9a, Ionization is biased. That is, as shown in FIG. 5, on the surface of the anion exchange membrane 9b, the concentration of [OH ⁻ ] is high due to the presence of the anion exchange group [—NH ₄ ⁺ ] and the like.
On the surface of a, the concentration of [H ⁺ ] is high due to the presence of the cation exchange group [—SO ₄ ^2- ] and the like.

Both [OH ⁻ ] and [H ⁺ ] have extremely high ion mobility, which causes charge transfer.

In addition, since the diaphragm 9 is wound around the diaphragm support member 7, the mechanical strength against external pressure is significantly enhanced. Further, the outer cloth 8 is spirally wound around the entire outer peripheral surface of the diaphragm 9 as described above, so that a sufficient pressure resistance is added to the internal pressure.

The diaphragm supporting member 7 on which the diaphragm 9 and the outer cloth 8 are wound
As shown in FIG. 1, first and second frames 20 and 21 are disposed at predetermined intervals on the outer peripheral sides of both ends of the frame 20. At the same time, a potting material 11 is provided on the inner diameter sides of the frames 20 and 21. Is filled,
Thereby, the insulating tubes 5, 6 and the diaphragm supporting member 7, the diaphragm 9, and the outer cloth 8 are simultaneously and firmly integrated. In this case, the first frame 20 is formed in a cylindrical shape, and when the potting material 11 is filled, the first frame member 20 has a first ring member 12 for preventing the potting material 11 before solidification from flowing out. Are arranged in the frame 20 of the first embodiment.

Further, the second frame 21 is formed in a bottomed cylindrical shape, and is filled with the potting material 11 as described above in a state where the diaphragm support member 7 and the insulating tube 6 and the like are inserted therein.
The whole is simultaneously and integrally fixed.

In this embodiment, an epoxy resin is used as the potting material 11, but a urethane resin or a phenol resin may be used.

In the present embodiment, hard vinyl chloride tubes are used as the first and second insulating tubes 5 and 6. Of these,
The first insulating pipe 5 is provided with a drain 13 as shown in FIG. 1, and a cap 14 is detachably provided at an upper end thereof. 5A denotes a spacer fixed to the upper end inner diameter side of the insulating tube 5.

On the other hand, the electrode portion 3 includes a tubular electrode 30 formed in a tubular shape made of stainless steel, a metal lid member 31 for hanging down the electrode attached to the upper end of the tubular electrode 30 in FIG.
It is composed of a power supply connection terminal 32 and a water supply section 33 provided on the lid member 31. Among them, the tubular electrode 30
Is formed to have an outer diameter smaller than the inner diameter of the first and second insulating tubes 5 and 6 of the main body 2 described above. For this reason, the attachment / detachment of the tubular electrode 30 to / from the main body 2 is facilitated, and at the same time, a part of the water flow mechanism 4 is formed between the main body 2 and the tubular electrode 30. . Further, the metal lid member 31 has an outer peripheral edge projecting from the tubular electrode 30, thereby forming the tubular electrode 30.
Are locked by a first insulating tube 5 as shown in FIG. For this reason, the electrode part 3 is very easily inserted and disposed in the main body part 2 from the outside, and can be easily detached to the outside as needed.

The water passage mechanism 4 is for discharging acetic acid and the like accumulated between the diaphragm 9 and the tubular electrode 30 to the outside. Specifically, the water passage mechanism 4 includes the above-described electrode section 3 and the main body section 2. I have. That is, the water flowing from the water supply section 33 of the electrode section 3 flows down the inside of the tubular electrode 30 as shown by an arrow in FIG. The fluid flows inside the diaphragm 9 while ascending on the outer peripheral side of the tubular electrode 30 and is forcibly discharged from the discharge portion 13 to the outside together with impurities.

A mounting bracket 1A for mounting to a bathtub during electrodeposition coating is wound around one frame 20 of the main body 2. Further, the outer cloth 8 wound on the outer surface of the diaphragm 9 is not necessarily limited to a cloth-like one, 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 spirally wound or a ring-shaped member may be mounted on the premise that the joint portion is waterproofed.

Here, the method of fixing the diaphragm 9 which is a main part of the main body 2 will be described in more detail.

First, an anion exchange membrane 9b constituting the diaphragm 9 is wound around the outer periphery of the diaphragm support member 7, and the abutting end edges thereof are abutted to fix the diaphragm 9 in a substantially circular cross section as shown in FIG. I do. A cation exchange membrane 9a is wound on this,
By overlapping the contact ends or abutting the contact edges, they are fixed in a substantially circular cross section as shown in FIG. Subsequently, the outer skin 8 is spirally wound around the outer surface of the cation exchange membrane 9a, whereby the integration of the membrane support member 7 and the membrane 9 is completed. Next, the above-described first and second insulating tubes 5, 6 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, 21 are arranged at predetermined intervals as described above. Then, the potting material 11 is filled in each of the frames 20, 21 and solidified, whereby the integration of the main body 2 is completed.

The sealing member 12 disposed inside the lower end portion of FIG. 1 of the first frame 20 is for preventing the potting material 11 before solidification from flowing out as described above.
After the potting material 11 is solidified, it may be removed. Next, the overall operation of this embodiment will be described. First, in the aqueous solution W for electrodeposition, when the object to be coated 100 and the membrane electrode device 1 are disposed, and the object to be coated 100 is used as a negative electrode and a DC voltage is applied using the tubular electrode 30 of the membrane electrode device 1 as a positive electrode, The electrode coating is immediately started in the same manner as described above, and the colloidal molecules of the coating resin component and the pigment having a positive charge in the aqueous solution are coated with the negative electrode substrate 10.
After moving toward 0 and adhering to the surface of the article to be discharged, the solids of the paint aggregate to form a coating film.

On the other hand, acetic acid having a negative charge is accumulated in the aqueous solution, and the acetic acid starts moving toward the tubular electrode 30 of the diaphragm electrode device 1 at the same time as the start of the electrodeposition coating described above. . Here, in the present embodiment, since the cation exchange membrane 9a is on the paint side, the flow of acetic acid, which is a neutralizing agent in the ED bath paint, is mostly blocked by the cation exchange membrane 9a and is directed to the tubular electrode 30 side. Acetic acid cannot be reached, and acetic acid accumulates in the electrodeposition aqueous solution W. However, since the cation exchange membrane 9a does not completely block acetic acid, a part thereof reaches the tubular electrode 30 and discharges. In this case, since the discharged acetic acid, which is a neutralizing agent, has a low concentration (several percent in this embodiment), almost all of the acetic acid is ionized. Therefore, the negatively charged acetic acid is the tubular electrode that is the anode during energization.
Acetic acid accumulates between the tubular electrode 30 and the septum 9 as a result of being drawn by 30. On the other hand, since pure water is forcibly circulated 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. On the other hand, due to the action of the anion exchange membrane 9b, the electrode
The outflow of the heavy metal ions flowing out from 30 to the aqueous solution for electrodeposition is effectively prevented.

The inventor actually measured the acid removal rate and heavy metal permeability in this case, and obtained an acid removal rate of 1.3 × 10 ^-6 [mol / Coulomb] and a heavy metal permeability of 0.058 × 10 _-6 [g / Coulomb]. .

(This value is somewhat inferior to the individual characteristic value of each of the above-mentioned diaphragms, but this is because, as described above, in the cation exchange membrane 9a, the cations moving from the polar solution side are separated by the anion membrane 9b. , And the charge passing through the cation membrane 9a,
Carriers are depleted and tend to carry charges by the passage of anions (acids), and the anion exchange membrane 9b
In this case, the acid is blocked by the cation exchange membrane 9a on the paint side, and the carrier of the anion is depleted, so that there is a tendency to carry charges by the passage of the cation. However, the diaphragm 9 is composed of the cation membrane 9a and the anion membrane 9b.
, The acid removal rate can be reduced to about 1/7 that of the conventional anion exchange membrane, and the permeation of heavy metals is about the same as that of the cation exchange membrane alone.
1/70 of 0.058 × 10 ^-6 [gram / coulomb].

As described above, according to the first embodiment, the other electrode provided corresponding to the object to be coated as one electrode is the tubular electrode 30, and around the tubular electrode 30, the insulating material is used. The membrane 9 is laminated with a membrane support member 7 made of the same, and the membrane 9 has a double structure of the anion exchange membrane 9b on the electrode 30 side and the cation exchange membrane 9a on the outside thereof. In addition to being able to greatly reduce compared to a membrane electrode device using an anion exchange membrane, it is possible to effectively prevent heavy metals from flowing from the electrode side to the paint side, and the electrode 30 is bare. There is an advantage that no sludge of the paint is generated because there is no paint. Further, the function of the diaphragm supporting member 7 can sufficiently withstand the above-mentioned fluctuation of the external pressure, and therefore can be used continuously for a long time. Since it was configured to force water to flow upward, polarized particles and air bubbles stagnating around the tubular electrode 30 were
Since the water-permeable outer cloth 8 is wound around the outer surface of the diaphragm 9 so that it can be forcibly removed, even if the tensile strength of the diaphragm 9 is extremely weak, it is sufficient for a change in internal pressure. There is an advantage that it can withstand this.

Therefore, when a plurality of the membrane electrode devices 1 configured and functioning as described above are used together with a conventional membrane electrode device equipped with an anion exchange membrane in an aqueous solution for electrodeposition, neutralization, which has been a problem in the past, has been problematic. Prevents excessive removal of the acid used as an agent, and paint components in an aqueous solution for electrodeposition (ED bath paint)
It is possible to almost completely prevent heavy metal ions from being mixed therein due to elution of the poles.

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

In the second embodiment, a diaphragm 19 is used instead of the above-described diaphragm 9.
Is characterized in that it is used. As shown in FIG. 2, the diaphragm 19 is composed of a base material 16 made of woven nylon or polyethylene, a cation exchange resin 17A on one surface (a surface on the paint side) 16a, and another surface (an electrode 30). (A side surface) 16b is a composite exchange membrane in which an anion exchange resin 17B is coated. Other configurations are the same as those of the first embodiment.

Even in this case, in addition to having the same operation and effect as the first embodiment described above, since the diaphragm 19 is formed by coating the cation exchange resin 17A and the anion exchange resin 17B on both surfaces of the base member 16, respectively. In particular, there is an advantage that the assembling work can be speeded up.

Third Embodiment Next, a third embodiment will be described with reference to FIG.

The third embodiment is characterized in that a diaphragm 29 is used in place of the diaphragm 9 of the first embodiment. As shown in FIG. 7, this diaphragm 29
A mixture obtained by mixing the powder of B and the powder of the cation exchange resin 17A at a ratio of 50:50, and coating a mixture 28 formed by binding with a binder C on both surfaces of a base material 16 made of woven nylon or polyethylene. It is an exchange membrane. Other configurations are the same as those of the second embodiment.

Even in this case, the same operation and effect as those of the first embodiment can be obtained.

This is because, by microscopically, mixing both types of exchange resins has the same effect as that of a multi-layer membrane system of cationic resin / anionic resin / cationic resin / anionic resin /... Conceivable.

In addition, even when the mixing ratio was between 10:90 and 90:10, an effect that could be used in terms of the acid removal rate was confirmed. As described above, according to the present embodiment, there is also an advantage that the acid removal rate can be set to various values only by changing the mixing ratio.

〔The invention's effect〕

Since the present invention is configured and functions as described above, according to this, the other electrode provided corresponding to the object to be coated as one of the electrodes is provided with one of the electrodes and a coating component of the aqueous solution for electrodeposition coating. A cation exchange membrane disposed on the object side or the other electrode side, and an anion exchange membrane disposed on the other electrode side or the object side opposed to the cation exchange membrane. Due to the double structure consisting of the membrane, for example, as in the above example, in the case of cation electrodeposition coating, when using this, the removal rate of the acid the diaphragm electrode device using a conventional anion exchange membrane It is possible to provide an unprecedented excellent electrode device for electrodeposition coating, which is capable of significantly reducing the pressure as compared with that of the prior art and effectively preventing the heavy metal from flowing from the electrode side to the paint side. .

When a plurality of the membrane electrode devices of the present invention configured and functioning as described above are used together with a conventional membrane electrode device equipped with an anion exchange membrane in an aqueous solution for electrodeposition, a neutralizing agent which has conventionally been a problem It has the excellent effect of preventing excessive removal of acid, and almost completely preventing heavy metal ions from being mixed into the paint component (ED bath paint) in the aqueous solution for electrodeposition due to elution of the pole. .

[Brief description of the drawings]

1 is a sectional view showing a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a sectional view of the diaphragm electrode device of the embodiment shown in FIG. Explanatory diagram showing the actual use state,
FIG. 4 is a diagram for explaining that an electric current flows between the cation exchange membrane and the anion exchange membrane, FIG. 5 is an explanatory diagram showing a flow path of water in the apparatus in FIG. 1, and FIG. FIG. 7 is an explanatory view showing a main part of a second embodiment of the present invention, and FIG. 7 is an explanatory view showing a main part of a third embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Electrodeposition membrane electrode device, 3 ... Electrode part as the other electrode, 9,19,29 ... Diaphragm, 9a ... Cation exchange membrane, 9b ... Anion exchange membrane, 16 ... Base material , 17A ……
Cation exchange resin, 17B …… Anion exchange resin, 100 ……
Coating object, W: aqueous solution for electrodeposition coating.

Claims (3)

(57) [Claims] 1. An electrode provided as one electrode corresponding to an object to be coated, and a diaphragm for separating the other electrode from the one electrode and a paint component of an aqueous solution for electrodeposition coating. In the diaphragm electrode device for electrodeposition coating, comprising: the diaphragm, a cation exchange membrane disposed on the object side or the other electrode side, and the other electrode side facing the cation exchange membrane or A diaphragm electrode device for electrodeposition coating, characterized in that it has a double structure comprising an anion exchange membrane disposed on the object side. 2. The composite membrane according to claim 1, wherein said membrane is a composite exchange membrane formed by coating a cation exchange resin layer on one surface of a base material and an anion exchange resin layer on the other surface. Diaphragm electrode device for electrodeposition coating. 3. The composite exchange membrane according to claim 1, wherein the membrane is a composite exchange membrane obtained by coating a base material with a mixture obtained by mixing an anion exchange resin and a cation exchange resin at a predetermined ratio. Diaphragm electrode device for electrodeposition coating.