JP2505608B2 - Antifouling equipment for structures in contact with seawater - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an antifouling device for structures that come into contact with seawater, such as ships and marine structures.

[Conventional technology]

As a means for antifouling structures that come into contact with seawater such as ships and marine structures, a means for applying antifouling paint to the water contacting parts of the structures has been generally adopted.

However, such means have the following drawbacks.

(1) Since the elution rate of the antifouling component of the antifouling material cannot be adjusted, it is not possible to respond flexibly to the season, ocean currents, water quality changes, etc.

(2) Since the content of poisonous substances in the antifouling material is limited, repainting work is required about every two years.

Therefore, the present applicant has previously filed Japanese Patent Application Nos. 61-247032 and 61-248897, as shown in the schematic diagram of FIG. 7, a steel plate 02 that constitutes the outer plate of a structure in contact with seawater 01. To
Insulating coating 03 such as epoxy resin and conductive coating 04 in which carbon powder is mixed with organic binder
Between the 04 and the electric conductor 05 made of steel or the like, the direct current power supply 06 sets the conductive coating film 04 to (+) and the electric conductor 05 is set to (-) to energize the conductive coating film 04 to the ocean. We proposed a device to generate active ingredients for biofouling prevention.

However, it has been found that such a device has the following problems.

(1) It is necessary to maintain the current density flowing into the seawater 01 at a certain value or more. Narrows.

(2) It is difficult to maintain the performance because the current density is different due to the variation in the film thickness of the conductive coating film 04.

(3) A low-resistance conductive coating film 04 is required to make the current density uniform, but a large amount of conductive powder needs to be mixed for that purpose, which makes manufacturing difficult.

Therefore, the present applicant previously proposed a device as shown in the schematic diagram of FIG. 8 as Japanese Patent Application No. 63-287190.

That is, in the figure, the same reference numerals as those in FIG. 7 indicate the same members as those in the figure, and 07 indicates a metal having a low specific resistance for coating the outside of the insulating coating film 03, a thin film sprayed film of a metal oxide, A first conductive film that is a fusion film or a vapor deposition film and is provided with a current-carrying end 08. Nickel, copper, titanium, aluminum, niobium, and the like are used as metals having a low specific resistance, and magnetite and dioxide are used as metal oxides. Manganese etc. can be used respectively.

Reference numeral 09 denotes a second conductive film that is formed of an oxidation resistant insoluble substance and an organic binder that further covers the first conductive film 07.
As the oxidation-resistant insoluble substance, graphite, carbon black, magnetite, white metal, etc. can be used, and as the organic binder, epoxy resin, vinyl resin, unsaturated polyester resin, etc. can be used. Also, this second conductive film
The electric resistance of 09 is higher than that of the first conductive film 07.

Reference numeral 010 is a cathode made of iron, copper, carbon or the like installed in seawater 01 so as to face the second conductive film 09, and 011 is the first conductive film 0.
The first conductive film is installed between the current-carrying end 08 of 7 and the cathode 010.
A direct current power source for supplying direct current from 07 to the cathode 010 through the second conductive film 09, and 012 is a lead wire connecting the steel plate 02 and the cathode 010.

In such an apparatus, when a direct current is caused to flow from the first conductive film 07 through the second conductive film 09 toward the cathode 010 in the seawater 01, the surface of the second conductive film 09 prevents marine organisms from attaching. Covered with a film of the active ingredient, it prevents marine life from adhering to its surface.

The direct current at this time is supplied from the current-carrying end 08 provided in the first conductive film 07 through the base current of the first conductive film 07 having a small electric resistance in the thickness direction of the second conductive film 09. Therefore, even if the second conductive film 09 is consumed, the current density does not concentrate near the current-carrying end 08, and a stable and uniform current density distribution can be maintained for a long period of time, which consumes less power. A high-performance antifouling effect can be achieved.

Since the lead wire 012 makes the steel plate 02 have a (−) potential and the first conductive film 07 and the second conductive film 09 have a (+) potential, the first conductive film 07, the second conductive film 07, When the conductive film 09 is locally damaged and destroyed and an exposed part is formed on the steel plate 02, a part of the direct current flowing out from the first conductive film 07 and the second conductive film 09 flows into the exposed part of the steel plate, The steel plate 02 is returned to the (−) pole of the DC power supply 011 to prevent the steel plate 02 from being corroded.

When the second conductive film 09 is damaged and destroyed and the first conductive film 07 is exposed, the first conductive film is prevented in order to prevent its chemical elution.
The use of titanium, niobium, metal oxides, etc. as the material of 07 is effective for long-term stabilization of this device.

However, in such a device, the first conductive film 07
Electrical resistance R ₀₇ <second conductive film 09 parallel to steel plate 02 of
There is a relation of the electric resistance R _{09 in} the direction parallel to the steel plate 02, and in order to make about 95% of the current received from the current-carrying end 08 flow in the first conductive film 07 and to make the current density distribution uniform, R ₀₇ / R ₀₉ ≦ 0.1 is preferable, and the thicknesses of the first conductive film 07 and the second conductive film 09 must be determined in consideration of the volume resistivity, the conduction of the conductive film 09, and the wear due to the influence of the external environment.

Next, an experimental example will be described with reference to FIG. 9, which shows a comparison of the effective conduction distance from the conduction end of the conductive film in this device and the conventional device. The conditions of each conductive film are as follows. is there.

This device First conductive film 07: Resistance 1.6 × 10 ^-3 Ω-m, film thickness 20 μm Second conductive film 09: Resistance 30 Ω-m, film thickness 200 μ Conventional device Conductive coating: Resistance 3 Ω-m, film thickness When a current of 80 μ is applied to such a conductive film from the current-carrying end, the conventional device (b) has a length of 3 m to maintain the required current density A, whereas this device (a) is effective up to 45 m. Further, in this device, the thickness of the second conductive film 09 is changed from 200 μ to 100 μm.
Although the effective distance did not change even if it changed to μm, it decreased to 1 m in the conventional device as shown in (c).

However, subsequent research has revealed that such a device has the following problems.

(1) Since the raw material of the first conductive film 07 is expensive, the cost increases if it is applied to the entire structure.

(2) When the first conductive film 07 is applied to the insulating film 03 by thermal spraying, residual stress is generated, so that defects such as peeling of the thermal sprayed film are likely to occur.

Therefore, the present applicant further discloses in Japanese Patent Application No. 1-139973, a structure in contact with seawater, characterized in that the first conductive film is formed in a parallel strip shape or a grid shape as shown in the schematic view of FIG. I applied for an antifouling device. An embodiment will be described with reference to the drawings. In the horizontal cross-sectional view of FIG.
Three parallel strips are attached to the top of the 3 and one end of each is a current-carrying end.
8 is a first conductive film connected to 8 and the material thereof is the same as that of the first conductive film 07. In this embodiment, a thin layer sprayed film of metal or metal oxide is used in consideration of workability. are doing.

Reference numeral 2 denotes a second conductive film that covers the outside of the first conductive film 011 and the material thereof is the same as that of the second conductive film 09.

In such an apparatus, since the first conductive film 001 is provided in a plurality of parallel strips, the amount of material can be reduced to a fraction of that of the first conductive film 07 coated on the entire surface. Further, since the first conductive film 001 has a strip shape, each width is small and residual stress on both side edges is reduced. Furthermore, the second conductive film 2
Has electrical conductivity, it is possible to supply power to the entire surface of the second conductive film 2 without coating the entire surface of the first conductive film 001.

Here, in order to see the effect of this embodiment, as shown in the front view of FIG. 12, a pair of left and right first conductive films 001 attached to the steel plate 02 and supplied with power through the current-carrying end 08 When an experiment was conducted in which the first conductive film 001 was an Al sprayed film and was covered with the conductive film 2 of No. 1 and was dc sprayed with a current density of 1 A / m ² or less from the second conductive film. No. 2 was a paint resin vinyl, and 40% by volume of graphite powder having a particle diameter of 45 μm or less was mixed as a conductive pigment, and the antifouling effective length 1 was 1 m when the film thickness thereof was 300 μm.

Next, FIG. 13 is a horizontal sectional view showing a modification of FIG.
Reference numeral 3 is a first conductive film which is attached on the insulating coating film 03 in a grid pattern with vertical and horizontal intervals and one end of which is connected to the conducting end 08, and 4 is a second conductive film which covers the outside of the first conductive film 003 and the like. It is a film, and even in such a modified example, substantially the same operation and effect as in the present example are obtained, and the first conductive film 003 should be applied due to an external force.
When a part of is cut off, a detour is automatically formed and the power supply to the downstream side can be maintained.

Furthermore, the schematic diagram of FIG. 14 shows a modified example of FIG. 10, and 5 is the amount of the conductive pigment made of an oxidation resistant insoluble substance of a metal type or a graphite type in order to reduce the resistance of the second conductive film. The lower layer of the second conductive film obtained by directly coating the first conductive film 001 or the like with a coating having an increased water content, and 6 is a pigment that improves the airtightness of the film in order to improve the electrolytic resistance of the second conductive film. The second conductive film upper layer is obtained by coating the second conductive film lower layer 5 with the coating material of which the amount is reduced, and in such a modified example, substantially the same operation and effect as those of the above-described embodiment are obtained. The feature is that the resistance of the second conductive film can be lowered, and thus the parallel spacing of the first conductive film 001 can be increased.

By the way, a submarine basic experiment similar to the procedure shown in Fig. 12 was conducted in paint resin acrylic with a particle size of 45 μm as a conductive pigment.
The following graphite powders are mixed at a volume concentration of 60% to a film thickness of 20
The second conductive film lower layer 5 having a thickness of 200 μm was applied to the second conductive film lower layer 5 having a thickness of 200 μm by mixing 40% by volume of graphite powder having a particle diameter of 45 μm or less in vinyl resin at a volume concentration of 0 μm. As a result, the antifouling effective length 1 was 5 m.

Further, in the same experiment, the second conductive film lower layer 5 was mixed with 30% by volume of copper powder in paint resin acrylic, and the film thickness was 200 μm.
The antifouling effective length 1 was 15 m.

[Problems to be Solved by the Invention]

However, subsequent research has revealed that such a device has the following problems.

(1) When applying a metal or metal oxide plate, if the adhesion method is adopted, workability on curved surfaces is poor, and it is necessary to hold the plate with braces until the adhesive hardens due to the weight of the plate. However, the workability is very poor and not practical.

(2) On the other hand, if the spraying method is applied, the workability is improved, but in order to obtain the durability of the conductive film due to the high roughness of the sprayed surface after the construction, it is necessary to increase the thickness of the conductive film thereabove. Not only that, but the spraying rate is slow and the cost is high.

The present invention has been proposed in view of such circumstances,
It is an object of the present invention to provide an antifouling device for a structure in contact with seawater, which is excellent in workability and cost efficiency for constructing a thin conductive film quickly and at low cost.

[Means for solving the problem]

To this end, the present invention provides a metal or metal oxide plate, a sprayed film, a vapor-deposited film or a fused film having a small specific resistance by coating the water contact surface of a structure in contact with seawater such as a ship or an offshore structure with an electrically insulating coating film. And a first conductive film having a current-carrying end provided at one end thereof, which is formed in a parallel band shape or a lattice shape, and which covers the outer side of the first conductive film and contains an oxidation-resistant insoluble substance and an organic binder. And a second conductive film having a larger electric resistance than the first conductive film, and an iron film facing the second conductive film,
An electrical conductor made of copper or carbon installed in seawater,
A structure comprising a power supply device that is installed between the first conductive film and the electric conductor, and that applies a direct current from the first conductive film through the second conductive film toward the electric conductor. In the antifouling device, the first conductive film is formed of a foil or a thin plate of metal or metal oxide.

[Action]

(1) Since thin plates and foils are lightweight and can be processed freely,
The first conductive film can be easily attached to a curved surface as well as a flat surface.

(2) No special equipment is required, the work can be performed accurately in a short time, and work efficiency can be significantly improved.

[Embodiment] An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view thereof, FIG. 2 is a horizontal sectional view taken along line II-II of FIG. 1, and FIG. FIG. 4 is a front view showing a basic experiment procedure in the sea, FIG. 4 is a horizontal sectional view showing a modification of FIG. 2, FIG. 5 is a schematic view showing a modification of FIG. 1, and FIG.
The figure shows the test results of the electrolytic durability of the second conductive film of FIG.

In the above figure, the same reference numerals as in FIGS. 7 to 14 indicate the same members as in FIGS. 7 to 14, respectively, and the present invention is greatly different from the conventional device in that the first conductive film is a foil or a thin plate. It has been formed.

First, in the schematic view of FIG. 1 and the horizontal sectional view of FIG.
Reference numeral 1 denotes a first conductive film which is attached to the insulating coating film 03 in a plurality of parallel strips and has one end connected to the current-carrying end 08, the material of which is the same as that of the first conductive film 07 shown in FIG. And
In this embodiment, considering workability, a metal or metal oxide 200 μ
A foil of m to 30 μm is used.

Reference numeral 2 is a second conductive film that covers the outside of the first conductive film 1 and the like, and the material thereof is the same as that of the second conductive film 09. The first conductive films 1 can be joined to each other by soldering.

Wiring from the onboard power supply to the energizing electrode and its connection should be done by using a thicker electric wire to reduce the voltage drop due to the resistance of the electric wire, and the connection part should be soldered or screwed.

Here, in order to see the effect of this embodiment, as shown in the front view of FIG. 3, a pair of left and right first conductive films 1 attached to the steel plate 02 and supplied with power through the current-carrying end 08 An experiment was conducted by covering it with a conductive film 2 of No. 1 and hanging it on a raft on the sea.
The conductive film 1 is made of aluminum foil with a thickness of 50 μm and the current density is 1 A / m
^A DC current is applied at a temperature of ² or less, and the second conductive film 2 mixes 40% by volume of graphite powder having a particle diameter of 45 μm or less as a conductive pigment into the coating resin vinyl, and the film thickness thereof is 300 μm.
The antifouling effective length 1 was 2 m.

The width of the current-carrying end was 30 mm, but the time required for the bonding work was 2 minutes. On the other hand, when the current-carrying end is sprayed with aluminum, a thickness of 100μ is required, and the time required is 30 minutes.

Next, FIG. 4 is a horizontal sectional view showing a modification of FIG.
Is a first conductive film which is attached on the insulating coating film 03 in a grid pattern with appropriate vertical and horizontal intervals and one end of which is connected to the current-carrying end 08, and 4 is a second conductive film which covers the outside of the first conductive film 3 and the like. Even in such a modified example, substantially the same operation and effect as in the present embodiment are obtained, and in addition, if a part of the first conductive film 3 is cut by an external force, the detour is automatically performed. Is formed and the power supply to the downstream side can be maintained.

Further, the schematic diagram of FIG. 5 shows a modified example of FIG. 1, and 5 is a metal-based or graphite-based conductive pigment composed of an oxidation-resistant insoluble substance for reducing the resistance of the second conductive film. The second coating of the increased paint directly on the first conductive film 1 etc.
The conductive film lower layer 6 of the second conductive film is coated on the second conductive film lower layer 5 with a paint containing a reduced amount of pigment in order to improve the airtightness of the film in order to improve the electrolytic resistance of the second conductive film. The second conductive film is an upper layer of the second conductive film, and even in such a modified example, substantially the same action and effect as those in the above-described embodiment are obtained, and the resistance of the second conductive film is reduced, and thus the parallelism of the first conductive film 1 is improved. It has the feature that the interval can be increased.

By the way, a basic experiment in the sea, which is the same as the procedure shown in Fig. 3, was conducted in paint resin acrylic with a particle size of 45 μm as a conductive pigment.
The following graphite powders are mixed at a volume concentration of 60% to a film thickness of 20
The second conductive film lower layer 5 having a thickness of 200 μm was applied to the second conductive film lower layer 5 having a thickness of 200 μm by mixing 40% by volume of graphite powder having a particle size of 45 μm or less in vinyl resin in a volume concentration. As a result, the antifouling effective length 1 was 5 m.

Further, in the same experiment, the second conductive film lower layer 5 was mixed with 30% by volume of copper powder in paint resin acrylic, and the film thickness was 200 μm.
The antifouling effective length 1 was 15 m.

On the other hand, in order to compare the electrolytic durability when the second conductive film is coated on the first conductive film, the paint for the second conductive film has a particle size of 45 μm or less as paint resin vinyl and conductive pigment. A mixture of 40% by volume of graphite powder was used.

According to this, as shown in FIG. 6, it is understood that the film thickness of the second conductive film can be reduced by 100 μm or more by applying the present invention.

〔The invention's effect〕

As described above with reference to the embodiments and modifications, the present invention has the following effects.

(1) By changing the first conductive film from an aluminum sprayed film to an adhesive film of aluminum foil, the performance does not change,
Workability can be significantly reduced.

(2) The film thickness for the upper layer can be reduced by 100 μm or more, and the economical efficiency is improved.

In short, according to the present invention, the water contact surface of a ship, a marine structure or the like that is in contact with seawater is covered with an electrically insulating coating film, and a metal or metal oxide plate having a small specific resistance, a sprayed film, a vapor deposition film or a fusion bond is formed. A first conductive film which is formed of a film and which is formed in a parallel band shape or a grid shape and has a current-carrying end at one end thereof;
A second conductive film that covers the outside of the first conductive film and is made of an oxidation-resistant insoluble substance and an organic binder and has a larger electric resistance than the first conductive film, and an iron that faces the second conductive film. , An electrical conductor made of copper or carbon that is placed in seawater, and the electrical conductor that is placed between the first conductive film and the electrical conductor and that passes from the first conductive film to the second conductive film. In a device for preventing soiling of a structure, which comprises a power supply device for applying a direct current to a conductor, a thin conductive film is formed by forming the first conductive film with a metal or metal oxide foil or thin plate. INDUSTRIAL APPLICABILITY The present invention is extremely useful industrially because it provides an antifouling device for a structure in contact with seawater, which is excellent in workability and economic efficiency for quick and low cost construction.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment in which the present invention is applied to a steel structure, FIG. 2 is a horizontal sectional view taken along line II-II in FIG. 1, and FIG. 3 is related to the apparatus shown in FIG. The front view showing the basic experiment procedure in the sea, FIG. 4 is a horizontal sectional view showing a modification of FIG. 2,
FIG. 5 is a similar schematic view showing a modification example of FIG. 1, and FIG. 6 is a view showing a result of a test of electrolytic durability of the second conductive film of FIG. FIG. 7 is a schematic diagram showing a known antifouling device for a structure in contact with seawater, and FIG. 8 shows an antifouling device for a structure in contact with seawater according to Japanese Patent Application No. 63-287190 of the present applicant. Fig. 9 is a schematic diagram showing the effective conduction distance of the device of Fig. 8 in comparison with the conventional device, and Figs. 10 to 14 are related to Japanese Patent Application No. 1-139973.
FIG. 10 is a schematic sectional view thereof, FIG. 11 is a sectional view taken along line II-II of FIG. 10, and FIG. 12 is a front view showing the undersea experimental procedure of FIG.
11 is a horizontal sectional view showing a modification of FIG. 11, and FIG. 14 is a schematic view showing a modification of FIG. 1 ... first conductive film, 2 ... second conductive film, 3 ... first
Conductive film, 4 ... second conductive film, 5 ... second conductive film lower layer, 6 ... second conductive film upper layer, 01 ... seawater, 02 ... steel plate, 03 ... insulating coating film, 08 ... energizing end, 010 ... cathode, 011 ... DC power supply, 012 ... lead wire, 001 ... first conductive film, 003 ... first conductive film.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Ueda Kenji Ueda 5-7, Atsunoura-machi, Nagasaki-shi, Nagasaki Ryoko Building Annex, 5th floor, Nagahishi Engineering Co., Ltd. No. 5-7 Ryoko Building Annex, 5th floor, within Nagahishi Engineering Co., Ltd. (72) Inventor Hiroshi Yamazaki No. 5 Satinoura-cho, Nagasaki City, Nagasaki Prefecture, No. 5 Ryoko Building, Annex, 5th floor Within Choryo Engineering Co., Ltd. (56) References JP-A 64-87791 (JP, A) JP-A 63-101464 (JP, A) JP-A 2-225574 (JP, A) JP-A 54-110588 (JP, A) JP-A 2 -147493 (JP, A)

Claims (1)

(57) [Claims] 1. From a metal or metal oxide plate, a sprayed film, a vapor-deposited film, or a fusion-bonded film, which has a low specific resistance by covering the water contact surface of a ship, a marine structure or the like which is in contact with seawater with an electrically insulating coating film. A first conductive film having a current-conducting end formed at one end thereof by forming it in a parallel band shape or a grid shape, the first conductive film, and the outer side of the first conductive film to cover the oxidation resistance. A second conductive film made of an insoluble substance and an organic binder and having a larger electric resistance than the first conductive film, and an electrically conductive member made of iron, copper or carbon facing the second conductive film and placed in seawater. A power supply device that is installed between the first conductive film and the electric conductor and that applies a direct current from the first conductive film through the second conductive film toward the electric conductor. In the antifouling device for a structure, the first conductive film is made of metal or metal acid. Antifouling apparatus of the structure in contact with seawater, and forming a foil or sheet of an object.