JPS62156172A - Underwater antifouling coating agent - Google Patents

Abstract

PURPOSE:The titled coating agent suitable for ships, fishing nets, etc., having small sliding angle on the surface of film of coating and improved antifouling properties, comprising a polymer containing a polydimethylsiloxane group, etc., at the side chain and a copolymer of a vinyl polymerizable monomer. CONSTITUTION:The aimed coating agent comprising (A) one or more polymers of a monomer [e.g., trimethylsiloxanethyl (meth)acrylate, etc.,] shown by formula (X is H or methyl group; n is 2-4; m is average polymerization degree and 0-70) and/or (B) a copolymer having <=70wt% (based on total amount of the components A and B) of one or more vinyl polymerizable monomer (e.g., methyl methacrylate, etc.,) copolymerizable with the component A as essential compo nent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an underwater antifouling coating containing a polymer having a polydimethylsiloxane group and/or a trimethylsilicon group in its side chain.

[Prior Art] Various problems occur on the surfaces of underwater objects immersed in seawater, such as ship bottoms, buoys, fishing nets, and various intake and drainage pipes for cooling, due to the adhesion of Fujibo, Serpura, mussels, algae, and the like. It is well known that an underwater antifouling coating agent is applied to the surface of objects immersed in seawater in order to prevent staining by these organisms.

Many underwater antifouling coatings use antifouling agents such as organic tin copolymers and cuprous oxide, which have an antifouling effect on living things and are slightly soluble in seawater. There is. However, in these cases, harmful substances may be eluted into the seawater, contributing to seawater pollution, and the effects on fish and shellfish may not be negligible.

Therefore, there has been a demand for an underwater antifouling coating that does not use such an antifouling agent and does not dissolve in seawater. Such non-toxic underwater antifouling coatings use silicone rubber that is vulcanized by the action of a catalyst or moisture, or vulcanized by the action of both a catalyst and moisture to three-dimensionally crosslink and form a film. Things can be given.

For example, Japanese Patent Publication No. 53-35974 discloses a coating using vulcanized silicone rubber, and Japanese Patent Application Publication No. 51-96830 discloses an oligomer tl'lJ corn rubber having a hydroxyl terminal group. A mixture with silicone oil is shown. Further, JP-A-53-79980 discloses a mixture of vulcanized silicone rubber and a fluid organic compound that does not contain metal or silicone. Furthermore, Japanese Patent Publication No. 60-3433 discloses oligomeric room-temperature curing silicone rubber (for example, Shin-Etsu Chemical Co., Ltd.'s product name K).
E45TS, KE44RTV, etc.) and liquid paraffin or petrolatum are mixed to prevent marine biofouling.

[Problem that the invention seeks to solve]

All of these conventionally known underwater antifouling coatings utilize the slipperiness of the silicone rubber coated surface to prevent aquatic organisms from adhering to the surface. Silicone rubber has the following problem in that it undergoes three-dimensional crosslinking to form a film during use.

The first is curing properties after painting. In other words, curing of silicone rubber occurs through hydrolysis of the crosslinking agent due to atmospheric moisture, or through a condensation reaction initiated by the action of a temperature-sensitive catalyst on the crosslinking agent, so the curing rate varies depending on atmospheric humidity and temperature. In addition, differences in curing strength occur, making it difficult to obtain uniformity of the film. For example, as shown in Japanese Patent Publication No. 60-3433, an underwater antifouling coating agent using an oligomeric room-temperature curing silicone rubber that hardens under the action of moisture in the air to form a film is applied to the surface to be coated. At this time, hardening occurs from the surface of the coating that is in contact with the humid atmosphere and progresses to the inside.The hardening of the surface first prevents moisture from passing through, and the moisture inside is insufficient. It is thought that it becomes difficult to obtain uniformity of the film as a result of hardening in deep portions being difficult to occur or crosslinking density becoming low. This results in poor adhesion of the film as a whole, such as peeling from the coated object and blistering. Furthermore, since moisture penetrates into the interior slowly, the time required for curing becomes longer.

For example, when such an underwater antifouling coating is used in a high temperature and high humidity location, curing is fast, but only the hydrolysis of the crosslinking agent takes priority, and the crosslinking density does not increase, resulting in a decrease in physical properties. . Furthermore, in dry areas, since there is little moisture in the atmosphere, hydrolysis of the crosslinking agent is difficult to occur and the curing of the film is extremely slow. Therefore, a problem arises in that painted objects cannot be moved in a short period of time. In order to prevent this, catalysts such as tin compounds and platinum are sometimes used as curing accelerators.
In low-lying wetlands, their catalytic activity decreases, making it difficult for the condensation reaction by the crosslinking agent to occur, resulting in extremely slow curing of the film.

Second, there is the problem of overcoatability. Normally, the solvent of the overcoat coating material slightly soaks the undercoat surface and forms a layer at the interface, which improves interlayer adhesion, but overcoatability on silicone rubber is affected by three-dimensional crosslinking of the base silicone rubber, which hardens. Therefore, the reapplied top coat does not soak the silicone rubber surface, resulting in poor adhesion.

Thirdly, there is the issue of pot life. Actual painting work can take longer than planned due to the size and complexity of the object to be painted, and sometimes it rains after painting has begun and the surface to be painted gets wet, or the atmosphere becomes too humid and the painting process is delayed. This may lead to a situation where the paint, which has already been opened and stirred, has to sit for a longer time than planned. In such cases, coating materials with a pot life are extremely inconvenient in painting operations.

Fourth, there is the issue of storage stability. Underwater antifouling coatings may be stored for a long period of time from the time they are manufactured until they are used, but those that harden due to moisture have short storage stability unless dry nitrogen gas is sealed during manufacture. Another problem is that when the lid of an open can is opened, moisture from the atmosphere enters, causing the surface of the coating to harden and thicken, making it difficult to reuse.

[Means for Solving the Problems] As a result of intensive research into the above points, the present inventors have developed the above-mentioned conventionally known underwater antifouling coating agent using silicone rubber alone or in combination with silicone oil, paraffin, etc. In addition, we have developed an underwater antifouling coating using a solvent-volatile polymer that has a smaller sliding angle on the film surface and can be expected to have better antifouling properties. Successful.

That is, the underwater antifouling coating agent of the present invention has the following general formula;
an integer of ~4, m represents an average degree of polymerization of 0 to 70) and/or one or more of the above monomers A and these It contains as an essential component a copolymer consisting of one or more types of vinyl polymerizable monomer monomer B that can be copolymerized with monomer B.

[Structure and operation of the invention]

In the underwater antifouling coating of the present invention, as an essential component, one or more polymers of monomer A represented by the above general formula (1), that is, a homopolymer or a copolymer (hereinafter referred to as , these are referred to as polymer A), or a copolymer of one or more of the above monomers A and one or more vinyl polymerizable monomers B copolymerizable with these monomers ( Hereinafter, these will be referred to as copolymers AB). Moreover, the above-mentioned polymer A and copolymer AB may be used in combination as necessary.

Both Polymer A and Copolymer AB have polydimethylsiloxane groups and/or trimethylsilicon groups derived from Monomer A in their side chains, so the coating formed from them has good slip properties. This coating effectively prevents aquatic organisms from adhering to the surface of underwater objects. The present inventors have found that such adhesion prevention effect is more pronounced than that of the conventional underwater antifouling coating agent, as shown in the examples described below.

In addition, since the above-mentioned polymer A and copolymer AB are soluble in organic solvents, they can be easily formed into a uniform film by applying a solution of the solvent to the surface of an object to be immersed in seawater and drying it. can do. Moreover, unlike the conventional reaction-curing type, the above-mentioned polymer A and copolymer AB are essentially non-reactive, so that the formation of the above-mentioned film is difficult due to moisture in the atmosphere. It is not affected by temperature and has excellent pot life and storage stability as a solution. Furthermore, when a similar or other coating is applied over this coating, the coating is immersed in the solvent of the topcoat, resulting in excellent glabellar adhesion with the topcoat. That is, all of the drawbacks of the conventional underwater antifouling coatings are eliminated by using the polymer A and/or copolymer AB.

Polymer A and copolymer AB exhibiting such effects
Monomer A for obtaining is an unsaturated monoester having a polydimethylsiloxane group (m; 2 or more) or a trimethylsilicon group (m = 1) in the molecule represented by the above formula (1). be. In formula f1), m = o to 70 because if it is larger than 70, the polymerizability or copolymerizability decreases, making it difficult to obtain a uniform film of Vine Polymer A or Copolymer AB. . Also, in formula f1),
The reason for setting n = 2 to 4 is that when n is less than 2, the bonding properties of the ester-forming part of monomer A become weaker, and the ester bonds dissociate during the polymerization stage or when used as a coating material, resulting in poor antifouling performance and This is because the durability of the polymer decreases, and when n exceeds 4, the polymer softens, making it difficult to form a film with a low surface tension and no sticky feeling.

Specific compound salts of monomer A represented by the above general formula +1) include trinotylsiloxaneethyl (meth)acrylate, which has a trimethylsilicon group;
Trimethylsiloxanepropyl (meth)acrylate, (
Assuming that trimethylsiloxane butyl meth)acrylate also has a polydimethylsiloxane group, m = 70
These include polydimethylsiloxane ethyl (meth)acrylate, polydimethylsiloxane propyl (meth)acrylate, and polydimethylsiloxane butyl (meth)acrylate. Note that the above (meth) means that it may be either acrylic acid or methacrylic acid.

Such monomer A is easily available as a commercial product, but to give an example of its synthesis, an ester of (meth)acrylic acid and alkylene glycol is obtained, and a trimethyl silicon compound or polydimethyl Examples include a method of subjecting a siloxane compound to a condensation reaction, and a method of obtaining an ester of (meth)acrylic acid and allyl alcohol, and subjecting it to an addition reaction with a trimethylsilicon compound or a polydimethylsiloxane compound.

Examples of the vinyl polymerizable monomer B used together with the monomer A to obtain the copolymer AB include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, and methacrylic acid. Methacrylic acid esters such as 2-hydroxyethyl, ethyl acrylate, butyl acrylate, acrylic acid 2
- Acrylic esters such as ethylhexyl and 2-hydroxyethyl acrylate, maleic esters such as dimethyl maleate and diethyl maleate, amaric esters such as dimethyl fumarate and diethyl fumarate, styrene, vinyltoluene, α -Methylstyrene, vinyl chloride, vinyl acetate, butadiene, acrylamide, acrylonitrile, methacrylic acid, acrylic acid,
Examples include maleic acid.

Such vinyl polymerizable monomer B acts as a modifying component to impart various performances to the antifouling film depending on the purpose of use, and also has a higher molecular weight than monomer A alone. It is also a convenient component for obtaining coalescence. The amount of monomer B to be used is set within an appropriate range, taking into consideration the above-mentioned performance and the antifouling effect based on monomer A. Generally, the proportion of monomer B in the total amount of monomer A is 90% by weight or less,
In particular, it is preferably 70% by weight or less. That is, if the proportion of the monomer A constituting the copolymer AB is at least 10% by weight - 1, especially at least 30% by weight, the antifouling effect based on this monomer A can be sufficiently exhibited, and therefore the above range The amount of monomer B to be used may be appropriately set within the range.

Polymer A and copolymer AB are produced by combining monomer A as described above or monomer B together with monomer A in the presence of a vinyl polymerization initiator.
It can be obtained by polymerization using various methods such as solution polymerization, bulk polymerization, emulsion polymerization, and suspension polymerization according to conventional methods. Examples of the vinyl polymerization initiator include azo compounds such as azobisisobutyronitrile and triphenylmethylazobenzene, benzoyl peroxide, diter
Examples include peroxides such as t-butyl peroxide.

The weight average molecular weight of polymer A and copolymer AB obtained by the above method is generally 1,000 to 150.000.
It is desirable that it be within the range of . If the molecular weight is too low, it will be difficult to form a film that can withstand use, and if the molecular weight is too high, the viscosity will be high when used as a coating varnish, and the resin solid content will be low, so only a thin film will be obtained with one application. First, there is the problem that several coats of paint are required to obtain a dry coating thickness greater than that of a window.

As mentioned above, the underwater antifouling coating of the present invention is usually used as a varnish prepared by dissolving polymer A and/or copolymer AB in an organic solvent. From this point of view, it is particularly desirable to employ a solution polymerization method or a bulk polymerization method as the polymerization method. In the solution polymerization method, the reaction solution after polymerization can be used as it is or diluted with a solvent.
In addition, in the bulk polymerization method, a solvent can be added to the reaction product after polymerization for use.

The organic solvents to be used include aromatic hydrocarbon solvents such as xylene and toluene, aliphatic hydrocarbon solvents such as hexane and heptane, ester solvents such as butyl acetate, and isoprobylalconoheptyl alcohol. Examples include alcohol solvents, ether solvents such as dioxane and diethyl ether, and ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, alone or in combination.

The amount of organic solvent used is such that the concentration of polymer A and/or copolymer AB in the varnish is usually 5 to 80% by weight, particularly 30% by weight.
It is desirable that the content be in the range of 70% by weight. The viscosity of the varnish at this time is generally 1, which makes it easy to form a film.
It is preferably in the range of ~10 poise/25°C.

The underwater antifouling coating of the present invention having such a structure may optionally contain a coloring agent such as a pigment such as Bengara, titanium dioxide, or a dye, which is non-toxic and does not dissolve in seawater. Further, ordinary anti-sagging agents, anti-color separation agents, anti-settling agents, leveling agents, anti-foaming agents, etc. may be added.

In order to form an antifouling film on the surface of an object to be immersed in seawater using the underwater antifouling coating of the present invention, for example, after applying the coating as a varnish to the surface of the object by an appropriate means, Simply dry at room temperature or under heat to volatilize and remove the solvent.

As a result, an antifouling film with low surface tension and good slip properties is uniformly formed.

As described above, the underwater antifouling coating of the present invention solves the first problem of curability by providing a strong coating only by solvent volatilization without requiring a chemical curing reaction. As for the second problem, overcoatability, since this coating is a solvent evaporation drying type, the surface is redissolved by the solvent of the coating that is applied after the film is formed, improving interlayer adhesion. is resolved. Furthermore, the third problem, pot life, and the fourth problem, storage stability, are not limited by the pot life and are stable because this coating is one-component and non-reactive. resolved as a good thing.

More surprisingly, the surface tension of the dry film of the underwater antifouling coating of the present invention is shown in Figure 1, which will be described later.

An investigation using the device shown in CB) to measure the sliding angle by dripping seawater revealed that the dried film of a conventional underwater antifouling coating made of silicone rubber alone or in combination with silicone oil, liquid paraffin, petrolatum, etc. was 12 to 15 degrees on average, whereas the underwater antifouling coating according to the present invention had an average of 8 to 10 degrees, which was about 30% smaller. This indicates that the dry film of the underwater antifouling coating of the present invention has a lower surface tension than that of the prior art and can be expected to have better efficacy against biofouling.

[Effects of the Invention] Since the underwater antifouling coating agent of the present invention is not of the type that undergoes a crosslinking reaction during film formation, it is not easily affected by curing and drying due to humidity, temperature, etc. Therefore, no deterioration in antifouling properties due to peeling, blistering, etc. due to insufficient curing of the coating is observed. Furthermore, since a film is formed on the surface to be coated by only the volatilization of the solvent when applied, drying is quick and the time required for recoating can be shortened, making it possible to use the coated object in a short period of time. Furthermore, it is easy to handle because the coating work is not restricted by pot life, and it is possible to improve the interlayer adhesion with the top coat when applying the top coat.

In addition, since it has good storage stability against humidity and heat, it is not necessary to fill it with dry nitrogen gas during production, which helps reduce costs. Furthermore, even if there is leftover paint left over from painting, it can be stored in the usual way, such as simply plugging it, and it can be reused easily. Moreover, the antifouling performance is further improved due to the low surface tension.

〔Example〕

Examples of the present invention will be described in more detail below in comparison with comparative examples. In addition, the polymer solutions (I) to (X) used in Examples 1 to 10 below and the polymer solutions (I) to (X) used in Comparative Examples 1 to 3 were prepared according to Production Examples 1 to 10 below. It is something. Parts in each production example are parts by weight, viscosity is 2
The Gardner viscosity measurement value and molecular weight at 5°C represent the weight average molecular weight determined by GPC method.

Production Example 1 120 parts of butyl acetate was placed in a flask equipped with a stirrer,
The temperature was raised to 100°C, and while stirring, 120 parts of methyl methacrylate and polydimethylsiloxanepropyl methacrylate were added as monomer A, in the general formula f+), where X is a methyl group,
A mixed solution of 120 parts of n=3 and average polymerization degree m of 10] and 1.2 parts of azobisisobutyronitrile was added dropwise over 2 hours, and after the addition was completed, the mixture was kept at the same temperature for 30 minutes. Then, a mixed solution of butyl acetate and 06 parts of azobisisobutyronitrile was added dropwise over 15 minutes, and after the addition was completed, stirring was continued at the same temperature for 3 hours to complete the polymerization reaction. Finally, toluene 8
0 parts was added and cooled to obtain a polymer solution (I+).

The obtained polymer solution (I) was transparent, had a viscosity, and had a molecular weight of 89,000 for the U11 portion.

Production Example 2 180 parts of butyl acetate was placed in a flask equipped with a stirrer,
The temperature was raised to 115°C, and while stirring, 169.2 parts of methyl methacrylate, 10.8 parts of ethyl acrylate, and polydimethylsiloxane propyl methacrylate were added to form monomer A. In the general formula f+), X is a methyl group. , n is 3, average degree of polymerization m is 3] 180 parts, azobisisobutyroni I-I
A mixed solution of 3.6 parts of Jul was added dropwise over 2 hours. Thirty minutes after the dropwise addition was completed, a mixed solution of 60 parts of butyl acetate and 1.8 parts of azobisisobutyronitrile was added dropwise over 15 minutes, and after the completion of the dropwise addition, stirring was continued at the same temperature for 3 hours to complete the polymerization reaction. .

Finally, 120 parts of xylene was added, cooled, and the polymer solution (
II) was obtained.

The obtained polymer solution (Ill) was transparent, had a viscosity, and had a molecular weight of 54,000 when combined with H11 parts.

Production Example 3 45 parts of methyl methacrylate and polydimethylsiloxanepropyl methacrylate in a heat- and pressure-resistant container [as monomer A, in the general formula, X is a methyl group, n is 3, and the average degree of polymerization m is 10] 55 parts of azobisisobutyronitrile, completely sealed and heated to 130°C while shaking, continued shaking at the same temperature for 2 hours to complete the polymerization reaction and obtain a solidified mass. Ta. Next, 100 parts of butyl acetate was added, and stirring was continued for 3 hours while maintaining the temperature at 130°C to dissolve the solidified material. After cooling, a polymer solution (a polymer solution was obtained).

The obtained polymer solution (2) was transparent, had a viscosity, and had a molecular weight of A1 copolymer of 9,000.

Production Example 4 50 parts of xylene was placed in a flask equipped with a stirrer, and 11
Raise the temperature to 0'C and add methyl methacrylate while stirring.
5 parts, polydimethylsiloxane ethyl acrylate [single j
As one body A, in the general formula (1), X is a hydrogen atom, and n is 2
, with an average degree of polymerization m of 70] and 3 parts of benzoyl peroxide were added dropwise over 3 hours. 30 minutes after the dropwise addition was completed, a mixed solution of 20 parts of Xyleph and 1.5 parts of benzoyl peroxide was added dropwise over 20 minutes, and after the dropwise addition, stirring was continued at the same temperature for 5 hours to complete the polymerization reaction.
Finally, 30 parts of methyl isobutyl ketone was added and cooled to obtain a polymer solution (5).

The obtained polymer solution (5) was translucent, had a viscosity of P, and had a copolymer molecular weight of 43,000.

Production Example 5 15 parts of xylene and 45 parts of ethylene glycol monoethyl ether were placed in a flask equipped with a stirrer, and heated to 120°C.
58 parts of methyl methacrylate, 2 parts of methacrylic acid, 5 parts of butyl acrylate, and 10 parts of styrene while stirring.
, polydimethylsiloxane butyl methacrylate [as monomer A, in the general formula flj, X is a methyl group, n is 4,
A mixed solution of 25 parts of polymer having an average degree of polymerization m of 30 and 06 parts of azobisisobutyronitrile was added dropwise over 3 hours. 30 minutes after the completion of the dropwise addition, a mixed solution of 20 parts of ethylene glycol monoethyl ether and 0.6 parts of azobisisobutyronitrile was added dropwise over 20 minutes, and after the completion of the dropwise addition, stirring was continued at the same temperature for 4 hours to carry out the polymerization reaction. Completed it. Finally, 10 parts of butyl alcohol and 35 parts of methyl ethyl ketone were added and cooled to obtain a polymer solution (V).

The obtained polymer solution (■) was transparent and had a low viscosity, and the molecular weight of the copolymer was 27,000.

Production Example 6 120 parts of xylene in a flask equipped with a stirrer, trimethylsiloxanepropyl methacrylate [as monomer A, in general formula (1), X is a methyl group, n is 3, and average degree of polymerization m is O] 100 parts of benzoyl peroxide and 15 parts of benzoyl peroxide were charged, the temperature was raised to 140° C. with stirring, and the stirring was continued for 3 hours in a transitional state to complete the polymerization reaction, and a polymer solution α was obtained.

The resulting polymer solution was transparent, had a viscosity of A3, and had a polymer molecular weight of 1,000.

Production Example 7 Place 30 parts of butyl acetate in a flask equipped with a stirrer, and add 8 parts of butyl acetate.
Raise the temperature to 0'C and add methyl methacrylate while stirring.
2 parts, butyl methacrylate 12 parts, polydimethylsiloxanepropyl methacrylate [as monomer A, general formula f
(in which X is a methyl group, n is 3, and average degree of polymerization m is 20)] and 0.6 parts of benzoyl peroxide were added dropwise over 4 hours. Thirty minutes after the completion of the dropwise addition, a mixed solution of 20 parts of butyl acetate and 0.2 parts of benzoyl peroxide was added dropwise over 20 minutes, and after the completion of the dropwise addition, stirring was continued at the same temperature for 5 hours to complete the polymerization reaction. Finally, 130 parts of toluene was added and cooled to obtain a polymer solution αID.

The resulting polymer solution (VfD) was transparent, had a viscosity of Z, and had a copolymer molecular weight of 150,000.

Production Example 8 120 parts of xylene was charged into a flask equipped with a stirrer, and 1
Raise the temperature to 05°C and add methyl methacrylate 1 while stirring.
20 parts, polydimethylsiloxane methyl methacrylate [
As the monomer A, a mixed solution of 120 parts of monomer A of the general formula flj, where X is a methyl group, n is 1, and average degree of polymerization is m or 8] and 12 parts of azobisisobutyronitrile was added dropwise over 2 hours.

After the dropwise addition was completed, the temperature was kept at the same temperature for 30 minutes, and then 1 part of a mixed solution of 40 parts of xylene and 0.6 parts of azobisisobutyronitrile was added.
The mixture was added dropwise in 5 minutes, and after the completion of the dropwise addition, stirring was continued for 4 hours at the same temperature to complete the polymerization reaction. Finally, 80 parts of xylene was added and cooled to obtain a polymer solution (Vllll).

The obtained polymer solution [phase] was cloudy, had a viscosity of W, and a copolymer molecular weight of 72,000.

Production Example 9 180 parts of butyl acetate was placed in a flask equipped with a stirrer,
The temperature was raised to 110°C, and while stirring, 150 parts of methyl methacrylate, 30 parts of butyl methacrylate, polydimethylsiloxane pentyl methacrylate [as monomer A, in general formula (1), X is a methyl group and n is 5, average degree of polymerization m is 2
] 180 parts, azobisisobutyronitrile 3,6
part of the mixed solution was added dropwise over 3 hours. 30 minutes after completion of dropping, add 60 parts of butyl acetate and 1.8 parts of azobisin butyronitrile.
A mixed solution of 50% was added dropwise over 15 minutes, and after the dropwise addition was completed, stirring was continued at the same temperature for 4 hours to complete the polymerization reaction.

Finally, 120 parts of xylene was added and cooled to form a polymer solution.
I got it.

The resulting polymer solution (2) was transparent, had a viscosity of K, and had a copolymer molecular weight of 65,000.

Production Example 10 In a heat-resistant and pressure-resistant container, 87 parts of methyl methacrylate, polydimethylsiloxane propyl methacrylate [as monomer A, in the general formula flll, X is a methyl group, n is 3, and the average degree of polymerization m is 75 113 parts and 4 parts of benzoyl peroxide were charged, completely sealed and heated to 120°C while shaking, and shaking was continued at the same temperature for 3 hours to complete the polymerization reaction and obtain a cloudy viscous substance. . Then, butyl acetate 10
0 parts was added and kept at 120°C while stirring for 1 hour to dissolve the cloudy viscous substance. After cooling, the polymer solution (
℃ was obtained.

The obtained polymer solution (X) was cloudy, had a viscosity of F, and had a copolymer molecular weight of 32,000.

Examples 1 to 10 Using polymer solutions (11 to
10 types of underwater antifouling coatings were prepared by mixing and dispersing them using a homomixer. In addition, among the ingredients, Oil Blue 2N
[Orient Chemical (product name of ceramic product) is dye, Disparon 6900-20X [water-capturing chemical product (product name of blank product]) and Aeroseal 300 [product name of Nippon Aeroseal ■]
Both are additives for sagging soil.

Comparative Examples 1-3 Polymer solution (VE) instead of polymer solution (11-(2))
Three dishes of underwater antifouling coatings having the formulation shown in Table 1 below were prepared in exactly the same manner as in Examples 1 to 10, except that I-(X) was used.

Comparative Examples 4 to 7 Instead of polymer solutions (I) to (2), KE45TS[
Product name manufactured by Shin-Etsu Chemical; Oligomeric room temperature curing silicone rubber 50% by weight toluene solution] or this and K
F-69 [product name manufactured by Shin-Etsu Chemical Co., Ltd.; silicone oil], 15OVG 10 (liquid paraffin according to JISK-2231), petrolatum No. 1 (JISK-223
Four types of underwater antifouling coatings having the compositions shown in Table 1 below were prepared in the same manner as in Examples 1 to 10, except that a mixture with petroleum wax (No. 5) was used.

Comparative Example 8 In the same manner as Examples 1 to 10, except that an organic tin copolymer solution was used instead of polymer solutions (I) to
An underwater antifouling coating having the composition shown in the table was prepared.

The above-mentioned organotin copolymer solution is a copolymer solution polymerized using 40 parts of methyl methacrylate, 20 parts of octyl acrylate, and 40 parts of tributyltin methacrylate.
The copolymer has a weight average molecular weight of 90.000 and is a transparent 50% by weight solution in xylene.

Each of the coating materials of Examples 1 to 10 and Comparative Examples 1 to 8 described above was subjected to the following physical performance test, measurement of the sliding angle of the coating surface, and antifouling performance test to evaluate the performance.

<Physical Performance Test> The storage stability, drying properties, and adhesion of each coating material were measured by the following methods. The results were as shown in Table 2 below.

A) Storage Stability 200ml of each coating was added to a mayonnaise bottle with a capacity of 250cc.
I put it in CC and sealed it with a lid. This was stored in a constant temperature and humidity chamber at a temperature of 70° C. and a humidity of 75%, and the storage stability was determined based on the degree of viscosity increase of each sample after 2 weeks. When the increase rate was less than 10% from the initial viscosity, it was evaluated as ○, when it was 10% or more and less than 100%, it was evaluated as Δ, and when it was 100% or more, it was evaluated as ×.

B) Drying property It was carried out according to the method of JIS K 5400.5.8.

That is, the measurement was performed on a glass plate coated with each coating agent to a wet film thickness of 100 μm using a film applicator. ○ if the semi-curing drying time is less than 1 hour;
1 hour or more and less than 3 hours was evaluated as △, and 3 hours or more was evaluated as ×. Each test plate was dried in a thermostatic chamber at a temperature of 20° C. and a humidity of 75%.

C) Adhesion It was carried out according to the method of the substrate test of JIS K 5400.6.15. That is, each coating agent was applied to a polished steel plate (150 x 70 x 1 +++++++) with a wet film thickness of 100 pn using a film applicator, and then applied for one week.
The coating was dried in a constant temperature and humidity chamber at a temperature of 20'C and a humidity of 75%, and a cut was made in a cross pattern reaching the base layer with a length of 20 mm using a cutter knife. Extrusion of 10 mm was performed from the back surface of the test plate at the center using an Erichsen tester. At that time, adhesion was determined by the length of peeling from the center of the cross-cut uneven portion of the coating surface. The evaluation was rated as ○ when the peeling was O, △ when the peeling was less than 5 mm, and × when the peeling was 5 mm or more.

Table 2 As is clear from the results in Table 2 above, drying properties.

Examples 1 to 10 for both adhesion and storage stability
was in good condition. Comparative Examples 4 to 7 using silicone rubber had poor drying properties, adhesion properties, and storage stability. Comparative Example 8 was slightly inferior only in storage stability. In addition, in Comparative Examples 1 to 3, surface tackiness remained even after drying.

Measurement of sliding angle of coating surface> Figure 1 (4) for each test plate used in the drying test.
The slip angle of the film surface was measured in the following manner using the slip angle measuring device shown in (B). The above measuring machine has a transparent glass plate 1 and a fixing jig 2 on the glass plate 1 with one end on the A side.
The movable plate 4 is fixed by a support column 3, and the other end B side is supported by a support column 3, and is provided so as to be movable upward along the support column 3.

First, as shown to the first prisoner, the test plate 5 is placed horizontally on the transparent glass plate 1 with the film forming side facing upward, with the movable plate 4 interposed therebetween. A water droplet 6 is formed by dropping 2 CC of sterilized filtered seawater using a syringe at one end A of 4, that is, at a position where the distance γ from the fixing jig 2 is 185 mm. Thereafter, as shown in FIG. 2(B), the other end B side of the movable plate 4 is moved upward along the support 3 at a speed of 1/sec to tilt the test plate 5. The inclination angle α at which the water droplets on the test plate 5 begin to slide was measured, and this was taken as the sliding angle of the coating surface.

The above measurements were performed in a constant temperature/humidity chamber at a temperature of 25° C. and a humidity of 75%, and each test panel was measured three times, and the average value was expressed. The results were as shown in Table 3 below.

Table 3 As is clear from the results in Table 3 above, Examples 1 to 10
The average temperature for those without pigment was 8.6 degrees, and the average temperature for those containing pigment was 9.3 degrees, compared to Comparative Examples 1 to 8.
This value was smaller than that of 12 to 25.0 degrees.

Antifouling performance test> Each coating was applied to a sandblasted steel plate coated with a tarvinyl rust preventive paint (100 x 200
x 1 mm), with a dry film thickness of 120μ on one side.
A test board was prepared by spray painting twice so that the result was as follows.

This test board was immersed in seawater for 24 months in Yura Bay, Sumoto City, Hyogo Prefecture, and the area occupied by attached organisms on the test coating (
The percentage of adhesion area) was measured over time. The results were as shown in Table 4 below.

Table 4 As is clear from the results in Table 4 above, Examples 1 to 10
Even after 24 months, the adhesion of organisms was 0%, but in Comparative Example 4, after 3 months, in Comparative Examples 1 to 3 and Comparative Examples 5 to 7, after 6 months, and in Comparative Example 8, after 18 months. Later, biological adhesion was observed.

In addition, the poor antifouling property of Comparative Example 1 is due to the polymer solution o used.
Since n in the general formula of monomer A in '111) is 1, the bond in the ester forming part is weak, and the polydimethylsiloxane group is detached during the polymerization reaction, causing adhesion when formed into a film. This is thought to be due to the fact that this part was extracted from the membrane in seawater, and the stain resistance did not last.

In addition, in Comparative Example 2, since n in the general formula of monomer A at ℃ used was 5, the film formed from this softened and remained sticky even after drying. It is thought that the tension increased and the antifouling properties deteriorated.Furthermore, in Comparative Example 3, m in the general formula of monomer A in the polymer solution α) used was as large as 75, so the polymerization reaction It is thought that this is because the unreacted monomer A separated from the membrane, the membrane became white and could not maintain its uniformity, and the antifouling durability deteriorated.

[Brief explanation of drawings]

FIG. 1(A), 03) is a side view showing a method for measuring the surface slip angle of an antifouling film formed from an underwater antifouling coating agent.

Claims (1)

[Claims] (1) The following general formula; ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(1) (However, in the formula, X is a hydrogen atom or a methyl group, and n is 2
an integer of ~4, m represents an average degree of polymerization of 0 to 70) and/or one or more of the above monomers A and these An underwater antifouling coating agent containing as an essential component a copolymer consisting of one or more vinyl polymerizable monomers B that can be copolymerized with the vinyl polymerizable monomer B.