JPH0930489A - Paint film for preventing deposition of marine organism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide uniform current distribution and expand a pollution preventing region by providing an electrifying band-like metal foil between an insulating paint film and a high conductivity conductive paint film, forming the insulating paint film having the width wider than that of the metal foil on the surface of the high conductivity conductive paint film right above the metal foil and further forming an antielectrolysis conductive paint film on the whole surface. SOLUTION: A band-like metal foil 3 connected to an electrifying terminal is applied to the surface of an insulating paint film 2 formed on the surface of a structure contacting the sea water. A high conductivity conductive paint film 4 is formed on the insulating paint film 2 having the metal foil 3 applied thereto. The band-like insulating paint having the width wider than the metal foil 3 is applied to the surface of the high conductivity conductive paint film 4 right above the band-like metal foil 3 to form a band-like insulating paint film 6. Further, An antielectrolysis conductive paint film is formed on the whole surface of the high conductivity conductive paint film 4 having the band-like insulating paint applied thereto. The band-like insulating paint film 6 restrains electric current from the concentration in the smallest resistance portion, i.e., right above the metal foil 3 to uniformize the current distribution and increase the effective length for preventing pollution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine organism adhesion preventing coating film which is formed on the surface of a structure in contact with seawater such as a ship and a minute electric current is applied to prevent the adhesion of marine organisms.

[0002]

2. Description of the Related Art In order to prevent marine organisms such as barnacles, mussels, mosquitoes, sea squirts, etc. from adhering to the surface of structures that come into contact with seawater such as ships, the attachment of marine organisms consisting of conductive coating films A method of preventing adhesion of marine organisms by forming a protective coating film and passing a minute electric current through the coating film to electrolyze seawater is performed. Conventionally, a marine organism adhesion preventing coating film as shown in FIG. 5 has been used for this purpose. This marine organism adhesion prevention coating is structure 1
An elongated strip-shaped metal foil 3 for connecting a terminal for energization is attached to the surface of the insulating coating film 2 formed on the surface of the substrate, and the highly conductive conductive coating is applied on the insulating coating film 2 to which the metal foil 3 is attached. The film 4 is formed, and the electrolytic resistant conductive coating film 5 is further formed on the film 4.

[0003]

In the above-mentioned marine organism adhesion preventing coating film of the prior art, the conductive coating film is energized through the metal foil attached to the lower surface of the conductive coating film. Therefore, titanium is used as the material of the metal foil, which does not dissolve even when electricity is applied in seawater. However, since titanium has a specific resistance larger than that of copper or aluminum by one digit or more, I
A potential drop occurs due to the R drop (a current drop I flowing through the conductive coating through the metal foil and a voltage drop caused by the resistance R of the metal foil), resulting in non-uniform current distribution and limiting the range in which contamination can be prevented. There is a problem.

The present invention aims to solve the above-mentioned problems in the prior art, and to provide a coating film for preventing adhesion of marine organisms, which can obtain a uniform current distribution and can expand a stain-proof possible region.

[0005]

Means for Solving the Problems The present invention is (1) a coating film formed on the surface of a structure which is in contact with seawater to prevent a marine organism from adhering by applying a minute electric current to the surface of the structure. In the marine organism adhesion preventing coating film, which comprises a coated insulating coating film, a highly conductive conductive coating film formed thereon, and an electrolytic resistant conductive coating film formed thereon, the insulating coating film and the high conductive film are highly conductive. A strip-shaped metal foil for connecting a current-carrying terminal to the conductive conductive coating is provided, and has a width wider than the metal foil on the surface of the highly conductive conductive coating directly above the strip-shaped metal foil. A marine organism adhesion preventing coating film having a structure in which a band-shaped insulating coating film is formed and an electrolytic resistant conductive coating film is formed on the entire surface of the highly conductive conductive coating film including the band-shaped insulating coating film. ,
(2) A coating film which is formed on the surface of a structure, at least the surface of which is in contact with seawater, is an insulator, and which allows a minute current to flow to prevent marine life from adhering, and which has high conductivity and conductivity formed on the surface of the structure. In a marine organism adhesion preventing coating film consisting of a coating film and an electrolysis resistant conductive coating film formed on the coating film, a terminal for energization is provided on the surface of the highly conductive conductive coating film to be adhered to the insulator surface of the structure. A strip-shaped metal foil that is connected and energized is attached, and a strip-shaped insulating coating film having a width wider than that of the metal foil is formed on the surface of the highly conductive conductive coating film immediately above the strip-shaped metal foil. A marine organism adhesion preventing coating film having a structure in which an electrolytic resistant conductive coating film is formed on the entire surface of a highly conductive conductive coating film including a coating film, and (3) above (1) or (2) ) Marine organisms adhesion prevention coating, the surface of the band-shaped insulation coating has a higher conductivity After coating with sex conductive coating, marine anti-biofouling coating characterized by comprising a structure obtained by forming the electrolyte-conductive coating on the whole surface, it is.

As an example of a structure to which the marine organism adhesion preventing coating film of the present invention is applied, there is a structure in contact with seawater such as a ship or an inner wall of a power plant intake channel. Examples of the material of these structures include steel, FRP, concrete, and the like whose surface is an insulator or conductor.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the marine organism adhesion-preventing coating film of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing one embodiment of the marine organism adhesion preventing coating film of the present invention. FIG. 1 shows an example in which the surface of the structure 1 is a conductor. The marine organism adhesion preventing coating film of FIG. 1 is obtained by attaching a strip-shaped metal foil 3 for connecting terminals for energization to the surface of an insulating coating film 2 formed on the surface of a structure 1 in contact with seawater. Highly conductive conductive coating film 4 on the insulating coating film 2 with
Is formed on the surface of the high-conductivity conductive coating film 4 directly above the strip-shaped metal foil 3, and a strip-shaped insulating coating film 6 is formed by coating the strip-shaped insulating coating film with a wider strip than the metal foil 3. It has a structure in which an electrolytic resistant conductive coating film 5 is formed on the entire surface of a highly conductive conductive coating film 4 coated with an insulating paint.

As a material for the insulating coating film 2 formed on the surface of the structure 1, an anticorrosive paint such as epoxy paint can be used. The thickness of the insulating coating film 2 is 100 μm or more, preferably 150 μm or more. If it is less than 100 μm, pinholes cannot be prevented and the insulating effect is not sufficient. The insulating coating film 2 can be formed by a method such as coating with various coating machines, roller coating, and brush coating. Note that F
When the surface of the structure 1 itself is an insulator such as an RP ship (insulated hull), the metal foil 3, the highly conductive conductive coating film 4, the strip insulating coating film 6 and the electrolytic resistant conductive coating film are used. 5, the insulating coating film 2 may be omitted. However, it is desirable to provide the insulating coating film 2 when there is a possibility that a defect such as water absorption may occur even with an insulator.

On the insulating coating film 2, a strip-shaped metal foil 3 for connecting a current-carrying terminal to conduct current is attached in parallel to the lengthwise direction at substantially the center of the antifouling target area. When the antifouling target area is wide, a plurality of metal foils 3 are attached at appropriate intervals. The material of the metal foil 3 is Cu, Al,
A metal foil such as Ti or a clad foil such as Ti / Al or Ti / Cu can be used, but a Ti foil is preferable from the viewpoint of durability when used for a long time in seawater. The specific resistance of these metallic materials is 5 × 10 ⁻⁵ Ω · cm for Ti and 1.5 × 1 for Cu.
0 ⁻⁶ Ω · cm, Al is about 3 × 10 ⁻⁶ Ω · cm.
The thickness of the metal foil 3 is 50 to 500 μm, preferably 50 to 500 μm.
The thickness is preferably 200 μm. If the thickness is less than 50 μm, the resistance is not sufficiently small and the effect of applying the foil is not sufficient. If the thickness exceeds 500 μm, the application becomes difficult, which is not preferable. The width of the metal foil 3 may be appropriately determined according to the type of the construction target structure, the size of the construction target area, the strength of the required current, etc., but in the case of a ship, it is 2 to 20 cm, preferably 5 to 1
0 cm. If it is less than 2 cm, the effect of applying the foil is not sufficient, and if it exceeds 20 cm, it is difficult to apply it on a curved surface or the like, which is not preferable. As a method of attaching the metal foil 3 onto the insulating coating film 2, there is a method of adhering it with a pressure sensitive adhesive or the like.

In this way, the highly conductive conductive coating film 4 is formed on the insulating coating film 2 to which the metal foil 3 is attached. The highly conductive conductive coating film 4 is made of paint resin such as acrylic resin, vinyl resin, epoxy resin, urethane resin in which carbons such as carbon black, graphite and carbon fiber are mixed as conductive pigments. The mixing ratio of the conductive pigment is 55 to 70% by volume, preferably about 60 to 65% by volume. If the mixing rate is less than 55% by volume, the conductivity is insufficient, and if it exceeds 70% by volume, the coating film becomes brittle and film formation becomes difficult. The resistivity of this highly conductive conductive coating film 4 is 5 × 10 ^−4.
It is about 5 × 10 ^-2 Ω · cm. This highly conductive coating 4
The thicker the film, the thicker the resistance of the coating film is and the wider the area is capable of antifouling, the thickness may be appropriately determined according to the size of the antifouling structure to be constructed. This highly conductive coating film 4 can be formed by a method such as an airless coating method.

Next, a strip-shaped insulating coating 6 is formed on the surface of the highly conductive conductive coating 4 directly above the metal foil 3 by applying a strip-shaped insulating coating wider than the metal foil 3. An electrolytic resistant conductive coating film 5 is formed on the entire surface of the highly conductive conductive coating film 4 having the strip-shaped insulating coating film 6 attached thereto. This strip insulation coating 6
Has the function of suppressing the concentration of the current in the portion with the smallest resistance, that is, in the direction directly above the metal foil 3, and making the current distribution uniform. The width of the strip-shaped insulating coating film 6 is made wider than the width of the metal foil 3 and is applied so as to protrude by 5 cm or more on both sides of the metal foil 3 when viewed from above. If the protrusion width is less than 5 cm, the effect of improving the current density distribution is insufficient. As the insulating paint, vinyl resin, acrylic resin, epoxy resin, urethane resin or the like can be used.

An electrolytic resistant conductive coating film 5 is formed on the entire surface of the highly conductive conductive coating film 4 coated with an insulating coating in a strip shape. The electrolysis resistant conductive coating film 5 is composed of a paint resin in which carbons such as carbon black, graphite and carbon fibers are mixed as a conductive pigment. As the paint resin, general paint resins such as vinyl chloride resin, acrylic resin, epoxy resin, urethane resin and their modified products such as silicon modified products and chlorinated products can be applied, but considering the durability, vinyl chloride resin Resins or modified products thereof are preferred. The mixing ratio of the conductive pigment is 30 to 50% by volume, preferably about 35 to 45% by volume. If the mixing ratio is less than 30% by volume or exceeds 50% by volume, the durability becomes insufficient, which is not preferable. The resistivity of this electrolysis resistant conductive coating film 5 is 0.
It is about 1 to 10 Ω · cm. The average thickness of the electrolytic resistant coating film 5 is 100 μm or more, preferably 250 μm.
That is all. If the average film thickness is less than 100 μm, a portion of 50 μm or less may occur due to the film thickness distribution at the time of coating, resulting in insufficient durability, which is not preferable. The electrolytic resistant conductive coating film 5 can be formed by a method such as airless coating.

If the width of the belt-shaped insulating coating film 6 is as wide as about 50 cm or more, the antifouling performance of that portion may be insufficient. Therefore, as shown in FIG. After coating the surface with a highly conductive conductive coating film 7 in a strip shape,
It is preferable to form the electrolytic resistant conductive coating film 5. As the material of the highly conductive conductive coating film 7 to be constructed here, the same material as the highly conductive conductive coating film 4 formed on the insulating coating film 2 on the surface of the structure may be used. . Further, the width of the strip-shaped highly conductive conductive coating film 7 covers the entire surface of the strip-shaped insulating coating film 6, and is connected to the high conductive conductive coating film 4 in the lower layer,
The thickness is preferably about 100 to 200 μm.

(Function) In the marine organism adhesion preventing coating film of the present invention, a strip-shaped insulating coating film is provided on the surface of the highly conductive conductive coating film directly above the strip-shaped metal foil for connecting terminals for energization. As a result, the ratio of (resistance in the vertical direction of the conductive coating film) / (resistance of the metal foil (longitudinal direction)) becomes large, which makes it easier for current to flow in the longitudinal direction of the metal foil, and makes the current distribution uniform. , The antifouling effective length is increased.

Further, the conductive coating film in the coating film for preventing adhesion of marine organisms of the present invention is such that the carbon content on the highly conductive conductive coating film to which a relatively large amount of carbons has been added in order to impart high conductivity. It has a two-layer structure in which an electrolytic resistant conductive coating film that is relatively small, dense, and has high durability is provided. for that reason,
There is no change in resistance of the lower conductive coating film, which is a factor controlling the current distribution, and the effective antifouling range is not narrowed, and stable antifouling performance can be obtained for a long period of time.

[0016]

The present invention will be described more specifically with reference to the following examples. A coating film for preventing adhesion of marine organisms according to the present invention and the prior art was formed on the inner surface of a concrete water tank, and seawater was filled to conduct an electric current test. An outline of the water tank used and the coating film formed is schematically shown in FIG. FIG. 3A is an explanatory view showing the general condition of the energization test, and FIG. 3B is a sectional view showing the outline of the formed coating film. Width 1m, length (depth) 20
m, a depth of 1 m, and a concrete water tank 10 having a width of 90 cm and a rectangle of 19.5 m in length, the epoxy-based insulating paint was applied to the inner surfaces of the concrete water tank 10 opposite to each other to form an insulating coating film 11 having an average film thickness of 250 μm. It was Next, the insulation coating 11 on both sides
Width 10 cm, thickness 50 parallel to the center of the surface of the
After attaching a Ti foil 12 having a length of 1 μm and a length of 19.5 m, a highly conductive conductive coating film 13 made of an acrylic resin mixed with 60% by volume of graphite powder is applied to the entire surface by airless coating with a thickness of 350 μm. Formed.

Thereafter, a highly conductive conductive coating film 1 is formed on one surface.
An electroless conductive coating film 14 made of vinyl chloride resin having 40% by volume of graphite powder is formed on the surface of 3 by airless coating to a thickness of 350 μm, which is a coating film for preventing adhesion of marine organisms by a conventional technique. It was set to A. On the other surface, the central portion of the surface of the highly conductive conductive coating film 13, that is, the portion directly above the insulating coating film 11 with a width of 30 cm and 150 μm.
After applying a vinyl chloride resin-based insulating paint with a thickness of 1 to form a strip-shaped insulating coating film 15, an electroless conductive coating film 14 made of the same material as the coating film A is formed to a thickness of 350 μm by airless coating. Thus, a coating film B which is a coating film for preventing adhesion of marine organisms of the present invention was obtained.

After forming a coating film and drying for about 10 days, a water tank 1
0 is filled with seawater, a current of 2A is applied from the end of the Ti foil 12 between the opposing coating films A and B, and electricity is applied so that (+) and (-) change at regular time intervals. A and B
The top potential was measured longitudinally at the anode. The results are shown in FIG. 4, and it can be seen that the coating film B according to the present invention has a longer length capable of maintaining a high electric potential and the antifouling effective length can be increased as compared with the coating film A which is a conventional technique.

[0019]

EFFECTS OF THE INVENTION According to the coating film for preventing attachment of marine organisms of the present invention, the potential drop in the longitudinal direction of the metal foil for energization can be suppressed to be small, resulting in a uniform current distribution and an effective antifouling length. Can be increased.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a marine organism adhesion-preventing coating film of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the marine organism adhesion preventing coating film of the present invention.

FIG. 3 is an explanatory view showing an outline of a water tank used in Examples and a coating film formed.

FIG. 4 is a graph showing the relationship between the distance from the current-carrying end and the magnitude of the anode potential in the current-carrying test of the example.

FIG. 5 is a sectional view showing an example of a conventional marine organism adhesion preventing coating film.

Claims (3)

[Claims] 1. A coating film which is formed on the surface of a structure in contact with seawater and which allows a minute electric current to flow therethrough to prevent the adhesion of marine organisms.
In a marine organism adhesion preventing coating film consisting of an insulating coating film formed on the surface of a structure and a highly conductive conductive coating film formed thereon and an electrolytic resistant conductive coating film further formed thereon,
A strip-shaped metal foil for connecting a current-carrying terminal is provided between the insulating coating film and the high-conductivity conductive coating film, and the surface of the high-conductive conductive coating film is provided directly on the strip-shaped metal foil. A strip-shaped insulating coating film having a width wider than that of the metal foil is formed, and the structure is such that an electrolytic resistant conductive coating film is formed on the entire surface of the highly conductive conductive coating film including the strip-shaped insulating coating film. A marine organism adhesion prevention coating. 2. A coating film which is formed on the surface of a structure, at least the surface of which is in contact with seawater, is an insulator and which allows a minute electric current to flow to prevent the adhesion of marine organisms, and which has high conductivity formed on the surface of the structure. Marine organism adhesion preventing coating film consisting of a conductive conductive coating film and an electrolytic resistant conductive coating film formed on the conductive conductive coating film, in order to apply current to the surface of the highly conductive conductive coating film that is adhered to the insulator surface of the structure. A strip-shaped metal foil for connecting terminals and energizing is attached, and a strip-shaped insulating coating film having a width wider than that of the metal foil is formed on the surface of the highly conductive conductive coating film directly above the strip-shaped metal foil. A marine organism adhesion preventing coating film having a structure in which an electrolytic resistant conductive coating film is formed on the entire surface of a highly conductive conductive coating film including a band-shaped insulating coating film. 3. The marine organism adhesion-preventing coating film according to claim 1, wherein the surface of the band-shaped insulating coating film is further covered with a highly conductive conductive coating film, and then an electrolytic resistant conductive coating film is formed on the entire surface. A marine organism adhesion-preventing coating characterized by having a formed structure.