JPH05179169A - Conductive layer for preventing adhesion of marine organism - Google Patents

Abstract

PURPOSE:To obtain the title conductive layer excellent in, e.g. resistance to electrolysis by seawater by forming the upper layer from a specified copolymer resin binder and a conductive filler in a conductive layer consisting of an upper layer and an under layer. CONSTITUTION:In a conductive layer consisting of an upper layer and an under layer, the upper layer is formed from: a binder comprising a copolymer resin which consists at least of 50-80wt.% vinyl chloride component, 5-30wt.% vinylidene chloride component, 1-10wt.% component comprising a vinyl ester of a carboxylic acid (e.g. vinyl acetate), and 5-21wt.% vinyl alcohol component produced from the vinyl ester component by saponification, the total of these components accounting for at least 95wt.% of the copolymer; and a conductive filler (e.g. graphite).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the prevention of adhesion of marine organisms by energizing the water contact part of an object that comes into contact with seawater, such as a ship, an offshore / undersea structure, a seawater guide / drainage facility, a seawater storage tank, or a quay wall. Regarding technology. More specifically, a conductive layer is provided so as to cover at least the water contact part (hereinafter simply referred to as "water contact part") of an object that comes into contact with seawater, and a direct current is applied to this conductive layer.
The present invention relates to the conductive layer in the technique of preventing the adhesion of marine organisms by electrolyzing seawater using the layer as an anode to generate chlorine, hypochlorous acid, etc. which marine organisms dislike.

[0002]

2. Description of the Related Art Conventionally, the wetted part of an object that comes into contact with seawater is coated with an antifouling paint containing an antifouling agent such as an organotin compound, and a gradually eluting antifouling agent prevents the adhesion of marine organisms. Is being done. However, since the elution rate of the antifouling agent cannot be adjusted and the amount of the antifouling agent contained in the paint is limited, repainting work is required, but it is difficult to repaint the wetted part and There is a risk of environmental pollution due to the elution of pollutants.

As a technique for preventing the adhesion of marine organisms in place of the above antifouling paint, a technique for preventing the adhesion of marine organisms by electrolysis of seawater has been developed.

To explain this in more detail, a conductive layer is provided on the water contact portion of the marine structure via an insulating layer, and this conductive layer is used as an anode, and a cathode is provided in seawater at an appropriate distance. The conductive layer is divided into two or more compartments, one part (one or more compartments) is used as an anode, and the rest is used as a cathode.
Apply a direct current of ² or less to electrolyze seawater,
It is intended to prevent the adhesion of chlorine, hypochlorous acid, etc., which marine organisms dislike, by generating them near the conductive layer that is the anode.

The above-mentioned conductive layer is provided as a coating layer of a conductive coating material or a composite layer of a coating layer of a conductive coating material and another material. Conventionally, the conductive coating layer and the conductive layer using the same are as follows. Something like is known.

(1) A conductive filler made of any one of graphite powder, carbon black, magnetite, manganese dioxide, and a platinum group metal is mixed with an epoxy resin.
A mixture containing 50% or more by volume of a coating material containing an unsaturated polyester resin, an acrylic resin, a phenol resin, or a urethane resin as a matrix (Japanese Patent Laid-Open No. 63-
No. 101464).

(2) A conductor wire embedded in an electrically conductive film composed of an electrically conductive filler of a metal such as carbon, magnetite, manganese dioxide, or platinum group and an organic binder (Japanese Patent Laid-Open No. 63-103789). Issue).

(3) Powder of conductive filler such as nickel, copper, titanium, niobium, magnetite and manganese dioxide,
Fillers, flakes and other small pieces mixed in an organic binder such as epoxy resin, vinyl resin, unsaturated polyester resin, acrylic resin, phenol resin, urethane resin, vinyl ester epoxy resin, etc. are provided in multiple layers,
One in which the specific resistance is increased stepwise from the inner side to the outer side (JP-A-64-87791).

[0009]

However, in the conductive layer formed by using the above-mentioned conventional conductive paint for preventing adhesion of marine organisms, seawater easily permeates and diffuses into the coating film constituting the conductive layer, and the electrolysis of seawater is also performed. Due to the contact with substances such as chlorine and hypochlorous acid generated by the above, deterioration and damage are likely to occur, and there is a problem of poor resistance to seawater electrolysis.

Specifically, cracking of the coating film, peeling of the coating film, detachment of the conductive filler, and loss of the conductive filler or conductive wire are likely to occur, resulting in a decrease in conductivity of the conductive layer. However, there is a problem that the prevention of adhesion of marine organisms cannot be maintained for a long period of time over a wide area of the water contact part.

The present invention has been made in view of these problems, and imparts a barrier property for preventing permeation and diffusion of seawater and a resistance to an electrolysis product of seawater,
It is an object of the present invention to provide a conductive layer for preventing adhesion of marine organisms, which has excellent resistance to electrolysis of seawater and can prevent adhesion of marine organisms over a wide range for a long period of time.

[0012]

Therefore, according to the present invention, in the conductive layer composed of the upper layer and the lower layer, the upper layer is composed of at least the following (A), (B), (C) and (D). Which is (A), (B), (C),
The ratio of (D) to the whole is 50-80% by weight, 5-30% by weight, 1-10% by weight, 5-21% by weight, respectively.
And (A) + (B) + (C) + (D) is 95% by weight or more of the whole as a binder, and is composed of the binder and a conductive filler. Is a conductive layer for preventing adhesion of marine organisms. (A) Vinyl chloride part. (B) Vinylidene chloride portion. (C) Carboxylic acid vinyl ester moiety. (D) A vinyl alcohol moiety resulting from (C) above by saponification.

The present invention will be further described in detail.

First, the upper layer will be described.

The proportion of the vinyl chloride moiety (A) in the copolymer resin used as the binder for the upper layer is 50 to 80% by weight, preferably 60 to 75% by weight. This ratio is 5
If it is less than 0% by weight, it is difficult to sufficiently prevent the permeation and diffusion of seawater into the coating film, and the resistance to electrolysis products is lowered, so that the seawater electrolytic resistance of the coating film is lowered. On the other hand, when it exceeds 80% by weight, the solubility of the copolymer resin in the solvent tends to decrease.

The proportion of the vinylidene chloride moiety (B) in the copolymer resin used as the binder for the upper layer is 5 to 30% by weight, preferably 10 to 25% by weight. This ratio is 5
If it is less than 30% by weight and if it exceeds 30% by weight, the same disadvantages as in the case where the ratio of (A) is less than the predetermined amount and when it exceeds the predetermined amount are likely to occur.

In the copolymer resin used as the binder for the upper layer, the proportion of the (C) carboxylic acid vinyl ester moiety is 1 to
It is 10% by weight, preferably 1 to 8% by weight. If this proportion is less than 1% by weight, the solubility of the copolymer resin in the solvent tends to be lowered. On the contrary, if it exceeds 10% by weight,
It is difficult to sufficiently prevent the permeation and diffusion of seawater into the coating film, and the resistance to electrolysis products decreases, so that the resistance of the coating film to seawater electrolysis decreases.

The proportion of vinyl carboxyl ester used in the copolymerization reaction is such that a part of the vinyl carboxylate ester moiety in the copolymer resin obtained by the copolymerization reaction is converted into a vinyl alcohol moiety by saponification. It is selected in consideration of what is done.

The carboxylic acid vinyl ester forming (C) may be used alone or in combination of two or more kinds. For example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl stearate, vinyl monochloroacetate, versatic. Vinyl acid etc. can be mentioned.

The (D) vinyl alcohol moiety in the copolymer resin used as the upper layer binder is formed by saponification of a part of the (C) carboxylic acid vinyl ester moiety in the resin, and the proportion thereof is 5 to 5. 21% by weight, preferably 5 to 15% by weight. If the amount is less than 5% by weight, it may be difficult to uniformly disperse the conductive filler in the coating material, or it may be difficult to obtain high reactivity when a cross-linking reaction is performed on the copolymer resin by utilizing the hydroxyl group of the vinyl alcohol portion. It's easy to do. On the other hand, if it exceeds 21% by weight, the solubility of the copolymer resin in the solvent tends to decrease, the viscosity of the conductive paint increases, and the hydrophilic group increases, so that the permeation and diffusion of seawater into the coating film occurs. It is difficult to prevent

The copolymer resin used as the binder for the upper layer includes, in addition to the above-mentioned (A) to (D), other monomers copolymerizable with the monomers forming (A) to (C). It is also possible to introduce part (E) in less than 5% by weight, preferably less than 3% by weight.

Explaining the monomer forming (E), in order to further improve the dispersibility of the conductive filler and the like in the conductive paint, unsaturated dicarboxylic acids, sulfonic acid ester monomers, and phosphoric acid are used. An ester monomer, a monomer having an acidic or basic polar group such as an amino group-containing vinyl monomer, or an epoxy group-containing vinyl monomer is preferable.

The unsaturated dicarboxylic acids refer to unsaturated dicarboxylic acids, unsaturated dicarboxylic acid anhydrides, unsaturated dicarboxylic acid esters, and unsaturated dicarboxylic acid salts. Examples of unsaturated dicarboxylic acids include maleic acid and itaconic acid. As the unsaturated dicarboxylic acid anhydride such as fumaric acid,
Examples of unsaturated dicarboxylic acid salts such as maleic anhydride and itaconic anhydride include monovalent metals, ammonia,
Examples thereof include salts such as amines. Further, examples of the unsaturated dicarboxylic acid ester include esters of unsaturated dicarboxylic acid such as methyl, ethyl, propyl, butyl, and 2-ethylhexyl, and the alkyl group preferably has about 1 to 8 carbon atoms. The ester may be a monoester, a diester or a mixture thereof.

Examples of the sulfonic acid ester monomer include vinyl sulfonic acid, 2-sulfoethyl methacrylate, 2-acrylamido-2-methylpropane sulfonic acid, and allylalkyl sulfosuccinic acid Na.

As the phosphoric acid ester monomer, for example, 2
Examples include acid phosphooxyethyl methacrylate, 2 acid phosphooxypropyl methacrylate, diphenyl 2-methacryloyloxyethyl phosphate, 3chloro 2 acid phosphooxypropyl methacrylate, and acid phosphooxypolyoxyethylene glycol monomethacrylate.

As the amino group-containing vinyl monomer, for example, N, N-dimethylaminoethyl methacrylate,
N, N-diethylaminoethyl methacrylate, N, N
-Dimethylaminopropyl acrylamide, t-butyl aminoethyl methacrylate, etc. are mentioned.

Examples of the epoxy group-containing vinyl monomer include glycidyl methacrylate, allyl glycidyl ether, glycidyl acrylate, and glycidyl-P-vinylbenzoate.

In addition, (E) is preferably a monomer having a silicon atom or a monomer having a fluorine atom in order to reduce the surface frictional resistance when a coating film is formed. .. Examples of these monomers include silicon macromonomers (AK-5, AK- manufactured by Toagosei Kagaku KK).
30), 3-methacryloxypropyltrimethoxysilane, vinylidene fluoride, vinyl fluoride and the like.

In order to improve the flexibility of the coating film and prevent the coating object from being damaged by expansion and contraction, vibration, etc., such as cracking and peeling, the alkyl ester side chain having 2 or more carbon atoms, for example. Also preferred are alkyl acrylates or methacrylic acid alkyl esters having, alkyl vinyl ethers having an alkyl ether side chain having 3 or more carbon atoms, ethylene and the like.

The above-mentioned monomers forming (E) may be used alone or in combination of two or more.

The copolymer resin used as the binder for the upper layer preferably has a weight average molecular weight of 20,000 to 120,000, more preferably 30,000 to 100,000. If the weight average molecular weight is less than 20,000, the strength and durability of the coating film tend to be insufficient, and if it exceeds 120,000, the solvent solubility and the coating workability of the coating material tend to be low.

The copolymer resin used as the binder for the upper layer is (A) to (C) or (A) described above.
It can be obtained by copolymerizing the monomers forming (B), (C) and (E) and then saponifying. The method of copolymerization is not particularly limited, and for example, solution polymerization, suspension polymerization, emulsion polymerization or the like can be performed. Specifically, it can be carried out by an ordinary apparatus, condition, operation and procedure for carrying out a polymerization reaction of vinyl chloride and vinylidene chloride. In the polymerization, a polymerization reaction initiated in a homogeneous system or a heterogeneous system may be changed to a heterogeneous system or a homogeneous system from the middle along with the progress of the polymerization.

The saponification can be carried out by a known method. For example, the obtained copolymer is treated with sodium hydroxide, an alkali metal alcoholate, hydrochloric acid, sulfuric acid, or the like in the presence of alcohol in a homogeneous or heterogeneous manner to form a carboxylic acid vinyl ester moiety of the copolymer. By saponifying a part of the amount, the copolymer used in the present invention can be obtained. There is no problem even if a part of the (E) portion is saponified during saponification.

The conductive filler in the upper layer is mixed in the form of powder, small pieces, short fibers, etc., which is easy to disperse,
There is no particular limitation as long as it is a solid substance having conductivity.
One or a combination of two or more substances or shapes can be used. Specific examples of the substance include graphite (natural graphite, artificial graphite), carbon black (gas black such as acetylene black,
Examples include carbons such as oil black and naphthalene black), magnetite, platinum group metals and other metals and alloys having conductivity. Among these, carbons are practical in terms of stability of the paint and cost. Further, in order to reduce the specific resistance of the conductive layer, it is preferable to use two or more kinds of conductive fillers having different average particle sizes in combination.

If the blending ratio of this conductive filler is too large, the coating workability, coating film forming property, and
The storage stability and the like decrease, and the barrier properties of the resulting coating film, the holding property of the conductive filler, the adhesion to the base, the strength and the like decrease. On the contrary, if the blending ratio of the conductive filler is too small, it becomes difficult to obtain conductivity of the coating film, or blistering occurs in a part of the coating film during seawater electrolysis. The mixing ratio of the conductive filler may be appropriately selected so that the properties such as the coating workability of the conductive paint and the barrier properties of the resulting coating film and the conductivity of the coating film are harmonized. Volume ratio (X) of the conductive filler to the total of the conductive filler and the binder is 5 to 7
It is preferably 0% by volume. Specifically, when X is lowered, it is preferable to use a conductive filler having a high oil absorption such as Ketjen Black. Conversely, when X is increased, an oil absorption such as graphite is preferably used. It is preferable to use a conductive filler having a small value. Here, X is a value represented by the following equation (1).

[0036]

[Equation 1] Next, the lower layer will be described. The lower layer is not particularly limited, but it is preferable to use a conductive layer containing a conductive filler, for example, a resin such as a vinyl resin, an epoxy resin, an unsaturated polyester resin, an acrylic resin, a phenol resin, or a urethane resin as a binder. it can. The specific resistance of the lower layer is not particularly limited, but if it is smaller than the specific resistance of the upper layer,
Concentration of the current density in the vicinity of the power supply connection portion in the lower layer can be easily prevented, and a uniform marine organism adhesion preventing effect can be obtained over a wide range, which is preferable.

Particularly preferable as the lower layer is a copolymer resin comprising at least the following (F), (G) and (H), and the ratio of (F), (G) and (H) to the whole is 80 respectively. ~ 98.5% by weight, 1-15% by weight, 0.5
Is 5% by weight, and (F) + (G) + (H) is 90% by weight or more of the whole, as a binder,
A conductive layer composed of the binder and a conductive filler. (F) Methyl methacrylate portion. (G) At least one monomer moiety selected from acrylic acid esters and methacrylic acid esters (excluding methyl methacrylate). (H) At least one monomer moiety selected from unsaturated dicarboxylic acids, phosphoric acid esters, sulfonic acid esters, amino group-containing vinyl monomers and epoxy group-containing vinyl monomers.

(F) Methyl methacrylate (hereinafter referred to as MMA) in the copolymer resin used as the lower layer binder
The proportion of the portion is 80 to 98.5% by weight, preferably 85.
~ 95% by weight. If this ratio is less than 80% by weight,
The specific resistance of the obtained conductive layer tends to increase. Conversely, 98.
If it exceeds 5% by weight, the solubility of the copolymer resin in the solvent tends to be lowered.

The proportion of at least one monomer moiety selected from (G) acrylic acid ester and methacrylic acid ester (excluding MMA) in the copolymer resin used as the lower layer binder is 1 to 15% by weight, preferably Is 2 to 5% by weight. If this proportion is less than 1% by weight, the solubility of the copolymer resin in the solvent tends to be lowered. Conversely 1
If it exceeds 5% by weight, the resistance to permeation and diffusion of seawater decreases.

Examples of the monomer forming (G) include ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate,
Tridecyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, isobornyl methacrylate, benzyl methacrylate, 2-hydroxyethyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, acrylic Tridecyl acid, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, benzyl acrylate, acrylic acid-
2-hydroxyethyl etc. are mentioned. These may be used alone or in combination of two or more.

The copolymer resin used as the binder of the lower layer is (H) unsaturated dicarboxylic acid, sulfonic acid ester monomer, phosphoric acid ester monomer, amino group-containing vinyl monomer and epoxy group-containing vinyl monomer. Introducing at least one monomer moiety selected from the following, the proportion of (H) in the copolymer resin is 0.5 to 5% by weight, preferably 1 to 3% by weight. .. If this proportion is less than 0.5% by weight, the adhesion to a metal or metal oxide having a low specific resistance and the dispersibility of the conductive filler will be reduced. On the other hand, if it exceeds 5% by weight, the resistance to seawater electrolysis of the coating film is lowered, and the barrier property is lowered to make it difficult to sufficiently prevent permeation and diffusion of seawater.

The unsaturated dicarboxylic acids refer to unsaturated dicarboxylic acids, unsaturated dicarboxylic acid anhydrides, unsaturated dicarboxylic acid esters, and unsaturated dicarboxylic acid salts. Examples of the unsaturated dicarboxylic acids include maleic acid and itaconic acid. As the unsaturated dicarboxylic acid anhydride such as fumaric acid,
Examples of unsaturated dicarboxylic acid salts such as maleic anhydride and itaconic anhydride include monovalent metals, ammonia,
Examples thereof include salts such as amines. Further, examples of the unsaturated dicarboxylic acid ester include esters of unsaturated dicarboxylic acid such as methyl, ethyl, propyl, butyl, and 2-ethylhexyl, and the alkyl group preferably has about 1 to 8 carbon atoms. The ester may be a monoester, a diester or a mixture thereof.

Examples of the sulfonic acid ester monomer include vinyl sulfonic acid, 2-sulfoethyl methacrylate, 2-acrylamido-2-methylpropane sulfonic acid, and allylalkyl sulfosuccinic acid Na.

As the phosphoric acid ester monomer, for example, 2
Examples include acid phosphooxyethyl methacrylate, 2 acid phosphooxypropyl methacrylate, diphenyl 2-methacryloyloxyethyl phosphate, 3chloro 2 acid phosphooxypropyl methacrylate, and acid phosphooxypolyoxyethylene glycol monomethacrylate.

As the amino group-containing vinyl monomer, for example, N, N-dimethylaminoethyl methacrylate,
N, N-diethylaminoethyl methacrylate, N, N
-Dimethylaminopropyl acrylamide, t-butyl aminoethyl methacrylate, etc. are mentioned.

Examples of the epoxy group-containing vinyl monomer include glycidyl methacrylate, allyl glycidyl ether, glycidyl acrylate, and glycidyl-P-vinylbenzoate.

These may be used alone or in combination of two or more.

The copolymer resin used as the binder of the lower layer includes, in addition to the above-mentioned (F) to (H), other monomers copolymerizable with the monomers forming (F) to (H). It is also possible to introduce less than 10% by weight of part (I), preferably less than 5% by weight.

Explaining the monomer forming (I), for example, in order to reduce the surface frictional resistance when a coating film is formed, (I) is a monomer containing a silicon atom, a fluorine atom is used. It is preferable that the monomer has.
Examples of these monomers include silicon macromonomers (such as AK-5 and AK-30 manufactured by Toagosei Co., Ltd.), 3
-Methacryloxypropyl methoxysilane, vinylidene fluoride, vinyl fluoride and the like.

In order to improve the flexibility of the coating film and prevent the coating object from being damaged by expansion and contraction, vibration, etc., such as cracking and peeling of the coating film, an alkyl ether side chain having 3 or more carbon atoms is used. Preferred are alkyl vinyl ethers, ethylene and the like.

The copolymer resin used as the lower layer binder preferably has a weight average molecular weight of 20,000 to 120,000, more preferably 30,000 to 100,000. If the weight average molecular weight is less than 20,000, the strength and durability of the coating film tend to be insufficient, and if it exceeds 120,000, the solvent solubility and the coating workability of the coating material tend to be low.

The copolymer resin used as the binder of the lower layer is (F) to (H) or (F) to which has been described above.
It is obtained by copolymerizing the monomer forming (I).
The method of this copolymerization is not particularly limited, and for example, solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization and the like can be performed. Specifically, an ordinary apparatus for carrying out MMA polymerization reaction,
It can be performed according to conditions, operations and procedures. Also, the polymerization is a polymerization reaction initiated in a homogeneous or heterogeneous system,
As the polymerization progresses, it may change to a heterogeneous system or a homogeneous system from the middle.

The conductive filler in the lower layer is mixed in the form of powder, small pieces, short fibers, etc., which is easy to disperse,
There is no particular limitation as long as it is a solid substance having conductivity.
One or a combination of two or more substances or shapes can be used. Specific examples of the substance include graphite (natural graphite, artificial graphite), carbon black (gas black such as acetylene black,
Examples include carbons such as oil black and naphthalene black), magnetite, platinum group metals and other metals and alloys having conductivity. Among these, carbons are practical in terms of stability of the paint and cost. Further, in order to reduce the specific resistance of the conductive layer, it is preferable to use two or more kinds of conductive fillers having different average particle sizes in combination.

If the blending ratio of the conductive filler is too large, the coating workability of the conductive paint, the coating film forming property, the storage stability, etc. are deteriorated, and the barrier property of the obtained coating film, the conductive filler are obtained. Retention, adhesion to the substrate, strength, etc. are reduced. On the other hand, if the blending ratio of the conductive filler is too small, it becomes difficult to obtain conductivity when the coating film is formed, or blistering occurs in a part of the coating film during seawater electrolysis. The mixing ratio of the conductive filler may be appropriately selected so that the properties such as the coating workability of the conductive paint and the barrier properties of the resulting coating film and the conductivity of the coating film are harmonized. The volume ratio (X) of the conductive filler to the total amount of the conductive filler and the binder is preferably 5 to 70% by volume. Specifically, when X is lowered, it is preferable to use a conductive filler having a high oil absorption such as Ketjen Black. Conversely, when X is increased, an oil absorption such as graphite is preferably used. It is preferable to use a conductive filler having a small value. Here, X is
It is a value represented by the above-mentioned formula (1).

[0055]

【Example】

Examples 1 to 20 and Comparative Examples 1 to 7 Copolymer resins having various compositions shown in Tables 1 and 2 were dissolved in an equivalent weight mixed solvent of toluene and methyl isobutyl ketone, and graphite having an average particle size of 2 μm was dry-coated. In addition to the volume concentration in the film being about 35% by volume, a conductive coating material for the upper layer was prepared.

On the other hand, as the conductive paint for the lower layer, a highly conductive acrylic resin is dissolved in the above-mentioned solvent, and graphite having an average particle diameter of 5 μm is added to the dry coating film at a volume concentration of 6%.
It was adjusted to be 0% by volume.

A conductive layer was produced using these conductive paints by the following procedure to prepare a test piece for dipping in seawater. A 1 inch long 1 m long iron pipe was hung down from the test piece with a distance of about 30 cm as a cathode. After turning on electricity, antifouling durability test was conducted in Nagasaki Port to evaluate the antifouling performance. The energization amount is 40 mA. A width of 35 cm, a length of 100 cm, and a thickness of 1 cm are parallel to one corner of one side of the acrylic plate, width is 1 cm, and length is 33 c.
m, and a copper foil having a thickness of 100 μm was attached. A single-core vinyl-coated copper wire was soldered in the vicinity of the center of the copper foil to form a conducting wire. Covering the copper foil, the thickness of the conductive coating after drying is 350μ
The conductive paint for the lower layer was airlessly coated so that the thickness became m. Further, an electrically conductive coating material for the upper layer was applied thereon by airless coating so that the thickness of the electrically conductive coating film after drying would be 350 μm. After drying at room temperature for about 1 week, it was subjected to an antifouling durability test.

The test results are shown in Table 2. It is clear that the present invention significantly improves the durability of the conductive layer and is effective in improving the economical efficiency of the electrolytic antifouling system using the conductive layer.

[0059]

[Table 1]

[0060]

[Table 2] Examples 21 to 40, Comparative Examples 8 to 14 Copolymer resins having various compositions shown in Tables 3 and 4 were dissolved in an equivalent weight mixed solvent of toluene and methyl isobutyl ketone, and graphite having an average particle size of 2 μm was dry-coated thereon. In addition to the volume concentration in the film being about 35% by volume, a conductive coating material for the upper layer was prepared.

On the other hand, as the conductive paint for the lower layer, among the following acrylic resins having high conductivity, those shown in Table 5 were diluted with the above-mentioned solvent, and graphite having an average particle size of 5 μm was added to the volume of the dry coating film. The concentration was adjusted to 60% by volume.

At least the following (F), (G) and (H)
A copolymer resin consisting of (F), (G), (H)
Of the total of 80-98.5% by weight,
1 to 15% by weight, 0.5 to 5% by weight, and (F)
Copolymer resin in which + (G) + (H) is 90% by weight or more of the whole. (F) Methyl methacrylate portion. (G) At least one monomer moiety selected from acrylic acid esters and methacrylic acid esters (excluding methyl methacrylate). (H) At least one monomer moiety selected from unsaturated dicarboxylic acids, phosphoric acid esters, sulfonic acid esters, amino group-containing vinyl monomers and epoxy group-containing vinyl monomers.

A conductive layer was produced using these conductive paints in the following procedure to prepare a test piece for dipping in seawater, and an iron pipe 1 inch long and 1 m long was hung down about 30 cm away from the test piece and used as a cathode. After turning on electricity, antifouling durability test was conducted in Nagasaki Port to evaluate the antifouling performance. The energization amount is 40 mA. A width of 35 cm, a length of 100 cm, and a thickness of 1 cm are parallel to one corner of one side of the acrylic plate, width is 1 cm, and length is 33 c.
m, and a copper foil having a thickness of 100 μm was attached. A single-core vinyl-coated copper wire was soldered in the vicinity of the center of the copper foil to form a conducting wire. Covering the copper foil, the thickness of the conductive coating after drying is 350μ
The conductive paint for the lower layer was airlessly coated so that the thickness became m. Further, an electrically conductive coating material for the upper layer was applied thereon by airless coating so that the thickness of the electrically conductive coating film after drying would be 350 μm. After drying at room temperature for about 1 week, it was subjected to an antifouling durability test.

The test results are shown in Table 4, and it is clear that the present invention significantly improves the durability of the conductive layer and is effective in improving the economical efficiency of the electrolytic antifouling system using the conductive layer.

[0065]

[Table 3]

[0066]

[Table 4]

[0067]

[Table 5] Examples 41 to 45, Comparative Example 15 The upper layer conductive paint and the lower layer conductive paint used in Examples 21, 23, 25, 36, 37 and Comparative Example 8, respectively, were applied to a 40-ton class passenger ship to reduce the size. I conducted a ship experiment. The size of the passenger ship is 20 m in length, 2.5 m in width, and 1.5 m in depth. The outer plate and the bottom of the ship are divided into 6 sections with the center of the bottom and the outer plate through an insulating film, and the opposing port side. And the starboard section 1
Set as a set and 3 sets as a pair for a certain time (for example, 2 hours)
A polarity switching method was used in which the anode and cathode were switched for each. The average current density is constant in all the sections, and the total energization amount is about 5A. The evaluation was carried out by a two-year antifouling durability test. As shown in Table 6, the effectiveness of the present invention was confirmed.

The procedure for applying a conductive coating film on a passenger ship is as follows.

After the outer skin of the hull was blasted, an epoxy-based insulating paint was applied to the coating film with an average film thickness (dry) of 400 μm.

A copper foil having a width of 3 cm and a thickness of 100 μm was attached to the upper end of each section outer plate in parallel with the deck, and a vinyl-coated copper wire was soldered in the vicinity of the center to form a conducting wire.

The copper foil is also covered and the film thickness after drying is 350 μm.
The conductive paint for the lower layer was airlessly coated so as to have m.

Further, an electrically conductive coating material for the upper layer was airless coated thereon so that the dry film thickness was 350 μm.

After coating, the product was dried for 7 days and then energized from a DC power supply device to start an actual ship test in the port of Nagasaki.

[0074]

[Table 6] Examples 46 to 50, Comparative Example 16 Examples 41 to 45 except that a 1-inch 10 m pipe is attached to the center of the bottom of the ship so as to maintain insulation with the hull so as to be a cathode in order to continuously energize the energization system. Comparative Example 1
In the same manner as in 5, the antifouling durability test for 2 years was performed.

Since the energization amount is the same, the current density is 1
/ 2. The result was almost the same as the polarity switching method described above, and the effectiveness was confirmed.

[0076]

The present invention is as described above. Since the conductive layer of the present invention has excellent resistance to seawater electrolysis, the prevention of adhesion of marine organisms by electrolysis of seawater over a wide range. It is possible to do it for a long time.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location H01B 5/14 Z 7244-5G // B63B 59/04 A 9035-3D (72) Inventor Akihiko Suzuki 2-5-1, Marunouchi, Chiyoda-ku, Tokyo Sanryo Heavy Industries Co., Ltd. (72) Inventor Kenji Ueda 216-12 Iwami-cho, Nagasaki-shi, Nagasaki Prefecture

Claims (6)

[Claims] 1. A conductive layer comprising two layers, an upper layer and a lower layer, wherein the upper layer is a copolymer resin comprising at least the following (A), (B), (C) and (D): B),
The ratio of (C) and (D) to the whole is 50 to 50, respectively.
80% by weight, 5 to 30% by weight, 1 to 10% by weight, 5 to 2
1% by weight, and (A) + (B) + (C) + (D)
Is a copolymer resin having a content of 95% by weight or more based on the total weight of the binder, and is composed of the binder and a conductive filler. (A) Vinyl chloride part. (B) Vinylidene chloride portion. (C) Carboxylic acid vinyl ester moiety. (D) A vinyl alcohol moiety resulting from (C) above by saponification. 2. The volume ratio (X) of the conductive filler to the total of the conductive filler and the binder in the upper layer is 5 to 7.
The conductive layer according to claim 1, which is 0% by volume. 3. The conductive layer according to claim 1, wherein the conductive filler in the upper layer is at least one selected from graphite powder and carbon black. 4. A lower layer is a copolymer resin comprising at least the following (F), (G) and (H):
The ratio of (G) and (H) to the whole is 80 to 9 respectively.
8.5% by weight, 1 to 15% by weight, 0.5 to 5% by weight, and (F) + (G) + (H) is 90% by weight or more of the whole, as a binder, The conductive layer for preventing attachment of marine organisms according to claim 1, 2 or 3, which is composed of the binder and a conductive filler. (F) Methyl methacrylate portion. (G) At least one monomer moiety selected from acrylic acid esters and methacrylic acid esters (excluding methyl methacrylate). (H) At least one monomer moiety selected from unsaturated dicarboxylic acids, phosphoric acid esters, sulfonic acid esters, amino group-containing vinyl monomers and epoxy group-containing vinyl monomers. 5. The volume ratio (X) of the conductive filler to the total of the conductive filler and the binder in the lower layer is 5 to 7.
The conductive layer according to claim 4, which is 0% by volume. 6. The conductive layer according to claim 4, wherein the conductive filler in the lower layer is at least one selected from graphite powder and carbon black.