JPH11166152A - Underwater antifouling coating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an underwater antifouling coating agent excellent in underwater antifouling capability and persistence thereof by incorporating an A-B type block copolymer comprising a specific polysiloxane-group-contg. graft polymer segment and a polymer segment contg. no polysiloxane group into the same. SOLUTION: An underwater antifouling coating agent having a viscosity (25 deg.C) of 1-10 P is prepd. by dissolving or dispersing, in an org. solvent, 5-80 wt.% A-B type block copolymer which comprises 10-70 wt.% polysiloxane-group- contg. polymer segment formed from 10-85 wt.% monomer of formula I or II [wherein R<1> is H or methyl; R<2> is methyl, ethyl, phenyl, or a group of formula III (wherein R<5> is H, phenyl, or Cp H2p+1 ; p is 1-10; R<6> is R<2> ; n is 1 or higher); R<3> is H, phenyl, or CQH2 Q+1 ; Q is p; R<4> is methy, ethyl, hydroxyl, or phenyl; and n is 1 or higher] and a vinyl monomer and having a number average mol.wt. of a polysiloxane group of 500-40,000 and 95-20 wt.% polymer segment contg. no polysiloxane group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater antifouling coating agent for preventing the attachment of aquatic organisms to the bottom of a ship, an underwater structure, a fishing net, various suction / drainage pipes for cooling, etc., immersed in seawater. In particular, the present invention relates to an underwater antifouling coating agent excellent in underwater antifouling properties and its long-term durability.

[0002]

2. Description of the Related Art Along with long-term use in water, such as ship bottoms, underwater structures, fishing nets, various suction / drainage pipes for cooling, etc., not only aquatic organisms attach and propagate during use, but also impair the appearance. The function may be adversely affected. In the case of a ship bottom, the attachment of aquatic organisms leads to an increase in the surface roughness of the whole ship, and furthermore, the ship speed decreases and the fuel efficiency increases. In addition, proliferation of bacteria causes enormous damage such as spoilage of underwater structures, deterioration of physical properties, and remarkable reduction in life. Conventionally, cuprous oxide, organotin compounds and the like have been known as underwater antifouling coatings used to avoid such damages. Physiologically active substances containing noble metals such as copper zinc oxide and organotin exhibit particularly excellent antifouling effects and have been considered as an essential component for ship bottom paints and fishing nets. For example, JP-A-60-231
No. 771 discloses that, for the purpose of promoting the dissolution of a biologically active substance such as an organotin compound or copper zinc oxide contained therein, a hydrolyzable Using a silyl (meth) acrylate such as tributylsilyl acrylate or triphenylsilyl (meth) acrylate.

[0003] However, this underwater antifouling coating agent has a problem that storage stability is poor, and gelling takes place within a few days especially when cuprous oxide is used in combination. As the underwater antifouling coating containing no noble metal as described above, a silicone rubber utilizing a small surface tension of silicone is disclosed as an underwater antifouling coating. For example,
JP-B-53-35974 discloses a vulcanized silicone rubber, and JP-A-51-96830 discloses a mixture using a mixture of an oligomeric silicone rubber having a hydroxyl terminal group and silicone oil. Further, JP-A-53-79980
The publication discloses a mixture of a vulcanized silicone rubber and an organic compound containing no metal or silicon. Also,
Japanese Patent Publication No. Sho 60-3433 discloses a mixture of an oligomeric, room temperature-curable silicone rubber and liquid paraffin or petrolactam. In addition, 5-6050
No. 3 discloses a graft copolymer of a silicone macromonomer and a vinyl monomer.

[0004]

The above-mentioned known underwater antifouling coating agent uses a low surface tension of a silicone-coated surface to prevent underwater organisms from adhering to the surface. In a single film, the siloxane portion exhibiting a low surface tension, which is related to the so-called antifouling performance, is fixed by crosslinking, and thus has no flexibility. Therefore, the surface tension could not be sufficiently reduced, and as a result, the antifouling ability in water was unsatisfactory. Also, the film obtained by physically mixing various fluids such as silicone oil and petrolatum with silicone rubber is also physically blended, so that when the coating film is immersed in the sea, these films are removed from the surface of the silicone rubber. The fluid will be released into the sea over time. Therefore, in the long term, the above-mentioned disadvantages of the silicone rubber single film are exhibited.

[0005] Further, unlike silicone rubber, a graft copolymer using a silicone macromonomer exhibits low surface tension due to an increase in the degree of freedom because one end group is not fixed. Since the adhesiveness with the base paint is not sufficient, the adhesive is eventually detached from the surface and the antifouling ability in water cannot be maintained for a long time. From these facts, it was recognized that any type had a problem in the antifouling effect, particularly the long-term durability of the underwater antifouling performance. An object of the present invention is to provide an underwater antifouling coating agent which does not have the above-mentioned disadvantages of the prior art, has excellent initial antifouling properties, and has remarkable durability.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on the above points, and have found that while maintaining the characteristics of the polysiloxane group involved in the antifouling property of silicone, it has a remarkable effect on the antifouling durability. Succeeded in obtaining the underwater antifouling coating shown
The present invention has been completed. That is, the first invention is AB
It is an underwater antifouling coating agent containing a type block copolymer,
The AB block copolymer comprises a polysiloxane group-containing graft copolymer segment A and a polymer segment B containing no polysiloxane group. Then, the graft copolymer segment A containing a polysiloxane group is composed of one or more of monomers represented by the following general formula (1) or (2) and one or more of vinyl monomers. And the polymer segment B containing no polysiloxane group is formed from one or more vinyl monomers.

[0007]

Embedded image [Wherein, R ¹ is a hydrogen atom or a methyl group, R ² is a methyl group,
An ethyl group, a phenyl group or the following formula (a);

[0008]

Embedded image (Wherein, R ⁵ is a hydrogen atom, a phenyl group, or C _P H
_{2P + 1} (P is an integer of 1 to 10), R ⁶ is a methyl group, an ethyl group, a phenyl group, and m is an integer of 1 or more. ), R ³
Is a hydrogen atom, a phenyl group or C _Q H _{2Q + 1} (Q is 1 to 10
Of an integer), R ⁴ is a methyl group, an ethyl group, a hydroxyl group or a phenyl group,, n is an integer of 1 or more. ]

[0009]

Embedded image [Wherein, R ¹ is a hydrogen atom or a methyl group, R ² is a methyl group,
An ethyl group, a phenyl group or the following formula (a);

[0010]

Embedded image (Wherein, R ⁵ is a hydrogen atom, a phenyl group, or C _P H
_{2P + 1} (P is an integer of 1 to 10), R ⁶ is a methyl group, an ethyl group, a phenyl group, and m is an integer of 1 or more. ), R ³
Is a hydrogen atom, a phenyl group or C _Q H _{2Q + 1} (Q is 1 to 10
), And n is an integer of 1 or more. ]

A second invention is an underwater antifouling coating comprising a general-purpose paint and the above-mentioned AB type block copolymer.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The AB type block copolymer of the present invention is composed of a polysiloxane group-containing graft copolymer segment A and a polymer segment B containing no polysiloxane group. And since the polysiloxane group-containing graft copolymer segment A has a polysiloxane group exhibiting a low surface tension, it is selectively oriented on the surface,
Shows antifouling properties. Further, the polymer segment B containing no polysiloxane group considers the adhesion to the substrate to be coated or the affinity for general-purpose paints such as vinyl chloride paints, vinyl acetate paints, and chloride rubber paints. By selecting and using the vinyl-based monomer thus obtained, the AB block copolymer is less likely to be detached from the coating film, so that it is possible to exhibit a long-lasting antifouling performance.

The polysiloxane group-containing graft copolymer segment A is composed of a polysiloxane group-containing monomer and a vinyl monomer. First, the former will be described below. Formula (1) having a vinyl group at one terminal group
When a monomer represented by is used, only one end is immobilized, so that the polysiloxane group portion, which is one end group, can move freely on the coating film surface, maintaining low surface tension. Can be expressed. Further, when a monomer represented by the general formula (2) having a vinyl group at both terminal groups is used, both terminal groups are fixed from the monomer represented by the general formula (1), The surface of the coating film cannot move freely, and the performance due to low surface tension is slightly reduced, but the strength of the coating film tends to increase. Furthermore, the general formula (1)
When the monomers represented by the formulas (2) and (2) are used in combination, the effects of the respective monomers tend to be expressed in a well-balanced manner. It is preferable that the proportion of the general formula (1) is 25% by weight or more based on the charged amount of the group-containing monomer.

R ₂ , R ₃ , and R ₄ in the general formula (1) or (2) of the monomer forming the polysiloxane group-containing graft copolymer segment A are, among the substituents defined above, They may be the same or different. In order to effectively exert the function of the polysiloxane group, it is preferable that the polysiloxane group is graft-linked to the polysiloxane group-containing graft copolymer segment A.
The polysiloxane group-containing monomer can be obtained as a commercial product. For example, product name Cyla Plane FM07
11, FM0721, FM0725, FM7711, FM7721, FM7725 (manufactured by Chisso Corporation) and the like correspond to this compound.

The preferred range of the polymer formed from the polysiloxane group-containing monomer in the polysiloxane group-containing graft copolymer segment A is 10 to 85% by weight.
It is. A more preferred range is from 20 to 70% by weight. If it is less than 10% by weight, the antifouling property cannot be sufficiently exhibited, and if it exceeds 85% by weight, it becomes difficult to obtain a high polymerization conversion.

The number average molecular weight of the polysiloxane group of the polysiloxane group-containing graft copolymer segment A is preferably from 500 to 40,000, more preferably from 1,000 to 20,000. When the number average molecular weight is less than 500, the antifouling property derived from the polysiloxane group tends not to be obtained. On the other hand, when the number average molecular weight exceeds 40,000, introduction of a polysiloxane group tends to be difficult.

Further, a vinyl monomer forming the polysiloxane group-containing graft copolymer segment A which is one of the segments in the AB type block copolymer (hereinafter, this monomer is referred to as an adhesion imparting component) -1) and a vinyl monomer forming a polymer segment B containing no polysiloxane group, which is the other segment of the AB type block copolymer (hereinafter, this monomer is referred to as an adhesion imparting component). -2) is appropriately selected according to various uses. By variously selecting the adhesion-imparting component-1 and the adhesion-imparting component-2, the adhesion to the substrate can be developed, and the antifouling performance can be maintained for a long time by the polysiloxane group. Adhesion imparting component-1 and adhesion imparting component-
As for 2, the following vinyl monomers can be used in consideration of ease of production and ease of introduction of a polysiloxane group. In addition, the same type of vinyl monomer or different vinyl monomers may be used for the adhesion-imparting component-1 and the adhesion-imparting component-2.

[0018] For example, methyl (meth) acrylate {hereinafter, acrylate and methacrylate are collectively referred to as (meth) acrylate. ｝, Lower alkyl (meth) acrylates such as ethyl (meth) acrylate, n-propyl (meth) acrylate, and isopropyl (meth) acrylate; n-butyl (meth) acrylate, isobutyl (meth) acrylate, ( Tert-butyl (meth) acrylate, n-hexyl (meth) acrylate,
Cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate,
Higher alkyl (meth) acrylates such as lauryl (meth) acrylate and stearyl (meth) acrylate; lower fatty acid vinyl esters such as vinyl acetate and vinyl propionate; vinyl butyrate, vinyl caproate, vinyl 2-ethylhexanoate, lauryl Higher fatty acid vinyl esters such as vinyl acrylate and vinyl stearate; aromatic vinyl type monomers such as styrene, vinyl toluene and vinyl pyrrolidone; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate ) Vinyl monomers containing a hydroxyl group such as acrylate and polypropylene glycol mono (meth) acrylate; vinyl monomers containing an amide group such as (meth) acrylamide, N-methylol (meth) acrylamide, and N-methoxymethyl (meth) acrylamide Type monomers; (meth) acrylic acid,
Carboxylic acid group-containing vinyl monomers such as itaconic acid, crotonic acid, fumaric acid and maleic acid; butadiene; vinyl chloride; vinylidene chloride; (meth) acrylonitrile; dibutyl fumarate; maleic anhydride; Dodecyl succinic anhydride; glycidyl (meth) acrylate; (meth) allyl glycidyl ether; alkali metal salts and ammonium salts of radically polymerizable unsaturated carboxylic acids such as (meth) acrylic acid, itaconic acid, crotonic acid,
Organic amine salts; radically polymerizable unsaturated monomers having a sulfonic acid group such as styrene sulfonic acid, and alkali metal salts, ammonium salts, and organic amine salts thereof;
Quaternary ammonium salts derived from (meth) acrylic acid, such as hydroxy-3-methacryloxypropylammonium chloride; (meth) acrylates of alcohols having tertiary amine groups, such as diethylamine (meth) acrylate And their quaternary ammonium salts.

Further, in consideration of the adhesion to the substrate and the copolymerizability with the polysiloxane group-containing monomer, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, Lower alkyl (meth) acrylates such as isopropyl (meth) acrylate; n-butyl (meth) acrylate, isobutyl (meth) acrylate,
Tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate,
Higher alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate; hydroxyethyl (meth) acrylate;
It is preferable to use a hydroxyl group-containing vinyl monomer such as hydroxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate, and polypropylene glycol mono (meth) acrylate.

The ratio of the adhesion-imparting component-1 in the polysiloxane group-containing graft copolymer segment A is 15 to 9
A range of 0% by weight is preferable, and a range of 30 to 80% by weight is more preferable. If the amount is less than 15% by weight, the conversion rate of polysiloxane to the graft copolymer segment A tends to decrease, and if it exceeds 90% by weight, the antifouling property based on the polysiloxane group tends to decrease.

The weight ratio of the polymer segment B containing no polysiloxane group to the graft copolymer segment A containing polysiloxane group is from 25/75 to 90/10.
It is preferred that If the weight ratio is less than 25/75,
If the antifouling property derived from the polysiloxane group is not sufficiently exhibited, and if the weight ratio exceeds 90/10, the effect of the block copolymer tends to decrease and the adhesion to the substrate tends to decrease.

The ratio between the adhesion-imparting component-1 in the polysiloxane group-containing graft copolymer segment A and the adhesion-imparting component-2 in the polymer segment B containing no polysiloxane group is by weight. 5/95 to 80/20 is preferable, and 10/90 to 70/30 is more preferable.
If the weight ratio is less than 5/95, the conversion ratio of the polysiloxane to the polymer portion decreases, and if the weight ratio exceeds 80/20,
Antifouling properties based on polysiloxane groups tend to decrease.

The AB block copolymer for an antifouling coating agent of the present invention is synthesized according to a conventional method such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method. For example, in the case of a solution polymerization method, a desired A is obtained by performing two-stage polymerization using a polymeric peroxide as an initiator.
-A type B block copolymer is obtained. This polymerization method,
It is manufactured by a known manufacturing process (for example, described in Japanese Patent Publication No. 5-41668, Japanese Patent Publication No. 5-59942, and Japanese Patent Publication No. 8-26160).

The polymeric peroxide used in the production of the AB block copolymer is a compound having two or more peroxy bonds in one molecule. As the polymeric peroxide, one or two or more of various polymeric peroxides described in Japanese Patent Publication No. 5-41668 can be used. For example, the following general formula (3)
To (5) can be used.

[0025]

Embedded image

[0026]

Embedded image

[0027]

Embedded image [In the formula, n is an integer of 2 to 20. ]

The method for synthesizing the AB block copolymer will be described in more detail. First, as a first step, a polymeric peroxide is used as a polymerization initiator, and a polysiloxane group-containing monomer and an adhesion-imparting component-1 are used. Is polymerized in a solution to obtain a copolymer containing a peroxy bond and a polysiloxane group in a chain. Next, as a second step, when a monomer constituting the adhesion-imparting component-2 is added to the solution obtained in the first step to carry out polymerization, a copolymer containing a peroxy bond and a polysiloxane group is obtained. By cleaving at the peroxy bond in the inside, an AB block copolymer can be obtained efficiently.

In the above two-stage polymerization,
The monomer constituting the polysiloxane group-containing monomer and the adhesion-imparting component-1 in the first step is referred to as the second step, and the monomer constituting the adhesion-imparting component-2 in the second step is referred to as the first step. It may be used in the process. The amount of the polymeric peroxide used in the first step in the production of the block copolymer is usually 0.5 to 20 parts by weight with respect to 100 parts by weight of the monomer used in the first step, and the temperature at that time is 40 parts by weight. ~ 130 ° C, polymerization time is 2
It is about 12 hours. The polymerization temperature in the second step is usually 40 to 140 ° C., and the polymerization time is about 3 to 15 hours.

Since the AB type block copolymer used in the present invention has a coating-forming ability, it may be used alone as an underwater antifouling coating agent in the form of a varnish dissolved in an organic solvent. Can be. From this point, it is particularly desirable to employ a solution polymerization method as the polymerization method. In this polymerization method, a reaction solution after polymerization can be used as it is or after dilution with a solvent.

Examples of the organic solvent used include methyl alcohol, ethyl alcohol, propyl alcohol,
2-propyl alcohol, 1-butyl alcohol, 2-
Butyl alcohol, 2-methyl-1-propanol, 2
-Methyl-2-propanol, 1-pentanol, 2-
Pentanol, 3-pentanol, cyclopentanol, 2-hexanol, 3-hexanol, cyclohexanol, methyl cellosolve, ethyl cellosolve, cellosolve acetate, acetone, 2-butanone, 3-methyl-2-butanone, 2-pentanone, 3-pentanone,
2-methyl-3-pentanone, 3-methyl-2-pentanone, 4-methyl-2-pentanone, 2,4-dimethyl-3-pentanone, 4,4-dimethyl-2-pentanone, 2-hexanone, 3- Hexanone, cyclopentanone, cyclohexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-hexanone, 5
-Methyl-2-hexanone, 5-methyl-3-hexanone, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl trimethyl acetate, isobutyl acetate, sec-butyl acetate, pentyl acetate, isoamyl acetate, propionic acid Methyl, ethyl propionate,
Propyl propionate, butyl propionate, isobutyl propionate, tert-butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, 2-methyl-methyl butyrate, caprone Methyl acid,
Benzene, toluene, ethylbenzene, xylene, cyclohexane, hexane, isohexane, isohexene,
Heptane, octane, isooctane, nonane, isononane, decane, undecane, dodecane, tridecane, isoparaffinic solvent (manufactured by NOF Corporation: NAS-3, N
AS-4, NAS-5H), formamide, acetamide, dimethylformamide, dimethylacetamide, acetonitrile, tetrahydrofuran, methylchloroform, hexafluoroisopropanol, (meth) paraxylenehexafluoride and the like. One or two or more of these solvents can be used.

Among these, particularly, as a good solvent for dissolving or dispersing the AB block copolymer,
Toluene, ethylbenzene, xylene, hexane, heptane, ethyl acetate, butyl acetate, isopropyl alcohol, butyl alcohol, 2-butanone, 4-methyl-2
-Pentanone, methyl cellosolve, ethyl cellosolve,
Cellosolve acetate and the like.

The amount of the organic solvent used is such that the concentration of the AB block copolymer in the varnish is 5 to 80% by weight, particularly 30 to 80% by weight.
It is preferred to be in the range of 70% by weight. The viscosity of the varnish at this time is preferably in the range of generally 1 to 10 poise / 25 ° C., which facilitates film formation.

The AB block copolymer can be used as an emulsion solution by adding a surfactant or the like and dispersing it in water. Further, the AB block copolymer may be used by adding it to a general-purpose coating material in the form of fine powder.

The AB block copolymer of the present invention can be used as an additive to a general-purpose paint which does not exhibit antifouling properties, and can impart antifouling properties. As a specific example of the general-purpose paint, a water-insoluble paint such as a vinyl chloride paint, a vinyl acetate paint, and a chloride rubber paint is used. When the AB block copolymer is used as an additive, it is preferably added in an amount of 1% by weight or more, more preferably 10% by weight or more, based on the resin component of the paint that does not exhibit antifouling properties. The addition is effective. This is because if the amount of the block copolymer is less than 1% by weight, it becomes difficult to exhibit the required antifouling property.

The underwater antifouling coating composition of the present invention thus constituted may include, if necessary, a coloring pigment, an extender pigment, another antifouling agent, an anticorrosive pigment, a dye, an anti-sagging agent, a plasticizer, and a coloring agent. Various compounding agents such as an inhibitor, an antisettling agent and an antifoaming agent may be added.

[0037]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Example 1 (A) Synthesis of Peroxy Bond-Containing Copolymer In a reactor equipped with a thermometer, a stirrer and a reflux condenser, 2-
While charging 57 g of butanone, 7 while blowing nitrogen gas.
Heated to 0 ° C. In addition, 57 g of 2-butanone, 56 g of methyl methacrylate, and a polysiloxane group-containing monomer (number average molecular weight = 10000) represented by the following formula (6) 2
A mixed solution consisting of 4 g and 6 g of a polymeric peroxide represented by the following formula (7) was charged over 2 hours, and a polymerization reaction was further performed for 4 hours.

[0038]

Embedded image

[0039]

Embedded image

Next, 2-butanone was removed from the polymer solution under reduced pressure at room temperature using an evaporator. The obtained polymer solid was pulverized. Further, 20 g of the obtained powder was charged into the reaction tank. And n-hexane 3
An operation of extracting unreacted polysiloxane group-containing monomers was performed by adding 00 g and stirring at room temperature for 20 hours. As a result of ¹ H-NMR analysis, the fine powder separated and taken out was found to be a polymer having a polymerization ratio of about 75/25 between methyl methacrylate and the polysiloxane group-containing monomer. This fine powder had an active oxygen content of 0.14% and was shown to have a peroxy bond. The number average molecular weight in terms of polystyrene measured by GPC is 21,000.
Met.

(B) Synthesis of AB type block copolymer 14 g of the peroxy bond-containing copolymer fine powder obtained by removing the unreacted polysiloxane obtained in the above (A), 7 g of methyl methacrylate, and 29 g of toluene were obtained. After mixing and dissolving, the mixture was charged into an ampoule purged with nitrogen. Then, this was reacted at 70 ° C. for 4 hours and further at 80 ° C. for 4 hours while stirring to synthesize an AB block copolymer. The obtained polymer solution was colorless and transparent. Measurement of residual methyl methacrylate by GC (gas chromatography) revealed that the polymerization conversion was 98%.

After the obtained polymer solution was reprecipitated in methanol and sufficiently purified and dried, the obtained polymer was pulverized with a ball mill to obtain fine powder. About this powder ¹
H-NMR analysis showed that the weight ratio of methyl methacrylate to polysiloxane group-containing monomer was about 82/17. From these results, the obtained polymer was AB composed of a copolymer segment A in which polysiloxane was grafted onto polymethyl methacrylate in a branched manner and a polymer segment B formed from polymethyl methacrylate. It was a type block copolymer, and it was revealed that the weight ratio of both polymer parts was about 67/33. (C) Preparation of antifouling underwater coating agent The AB-type block copolymer obtained by dissolving with xylene so that the solid content was 30% by weight was used as the underwater antifouling coating agent. .

Example 2 In Example 1 (A), instead of 24 g of the polysiloxane group-containing monomer represented by the formula (6), 16 g of the polysiloxane group-containing monomer represented by the formula (6) was used. Except that 16 g of a polysiloxane group-containing monomer (number average molecular weight = 5000) represented by the following formula (8) was charged, an AB block copolymer was synthesized in the same manner as in Example 1 except that the underwater protection was performed. Used as a soil coating.

[0044]

Embedded image

Then, in the same manner as in Example 1, analysis was performed after removing unreacted polysiloxane. As a result, the polymerization ratio of methyl methacrylate to the polysiloxane group-containing monomer in the peroxy bond-containing copolymer was about 75/25. The active oxygen content is 0.14% and the number average molecular weight is 3
4000. Further, from the result of analysis after the synthesis of the AB type block copolymer, a copolymer segment A in which polysiloxane was grafted onto polymethyl methacrylate in a branched manner, and a polymer segment B formed from polymethyl methacrylate, And it was revealed that the weight ratio of both polymer parts of the segment A and the segment B was about 67/33. The number average molecular weight of the AB block copolymer is 420
00.

Example 3 (A) Synthesis of Peroxy Bond-Containing Copolymer In the same reactor as in Example 1, 400 g of toluene was charged.
Heated to 70 ° C. while blowing nitrogen gas. in addition,
A mixed solution consisting of 170 g of toluene, 160 g of methyl methacrylate, 180 g of n-butyl methacrylate, 60 g of 2-hydroxyethyl methacrylate, and 30 g of the polymeric peroxide represented by the formula (7) was charged over 2 hours. The polymerization reaction was performed for an hour. The polymerization conversion was 96%, and the number average molecular weight of the obtained polymer was 14,000.

(B) Synthesis of AB type block copolymer 50 g of the polymer solution obtained in the above (A) was charged into the same reactor as above. While blowing nitrogen gas into the mixture, 18 g of a polysiloxane group-containing monomer (number average molecular weight = 10000) represented by the formula (8), methyl methacrylate 6
g, 6 g of n-butyl methacrylate, and 45 g of toluene were charged over 30 minutes.
For 3 hours. After the completion of the reaction, the content of the polymer was 39.2% by weight.

(C) Preparation of antifouling underwater coating agent The AB type block copolymer obtained by dissolving with xylene so that the solid content becomes 30% by weight was used. Used as

Example 4 A-A-A was prepared under the same conditions as in Example 3 except that the polysiloxane group-containing monomer represented by the formula (8) was changed to the one having a number average molecular weight of 500 in (B) of Example 3. A B-type block copolymer was synthesized and used as an underwater antifouling coating agent. The content of the polymer was 39.4% by weight.

Example 5 A-A-A was prepared under the same conditions as in Example 3 except that the polysiloxane group-containing monomer represented by the formula (8) was changed to the one having a number average molecular weight of 50,000 in (B) of Example 3. B
A block copolymer was synthesized and used as an underwater antifouling coating agent. The content of the polymer was 39.5% by weight.

Example 6 In Example 3 (B), 18 g of the polysiloxane group-containing monomer represented by the formula (8) was obtained by number-average molecular weight 10,000
The same conditions as in Example 3 were used, except that a mixed composition of 9 g of the polysiloxane group-containing monomer represented by the above formula (8) and 9 g of the polysiloxane group-containing monomer represented by the above formula (6) was used. Synthesizing an AB block copolymer,
Used as an underwater antifouling coating. The solid content concentration after completion of the polymerization was 39.3% by weight.

Example 7 (A) Synthesis of Peroxy Bond-Containing Polymer The same reactor as in Example 1 was charged with 170 g of 2-butanone and heated to 70 ° C. while blowing in nitrogen gas. In addition, 185 g of 2-butanone and methyl methacrylate 8
0 g, 80 g of a polysiloxane group-containing monomer (number average molecular weight = 10000) represented by the formula (8), and 15 g of a polymeric peroxide represented by the formula (7) were charged over 2 hours, The polymerization reaction was further performed for 4 hours. Next, unreacted polysiloxane was removed by the same operation as in Example 1 to obtain a fine powder of a peroxy bond-containing polymer. The fine powder separated and taken out is ¹ H-N
As a result of MR analysis, it was a polymer having a polymerization ratio of methyl methacrylate and the polysiloxane group-containing monomer of about 55/45.

(B) Synthesis of AB type block copolymer 54 g of the fine powder obtained in (A) above, from which unreacted polysiloxane had been removed, was dissolved in toluene and adjusted to 40% by weight. This polymer solution was charged into the same reaction apparatus as in the above (A), and nitrogen was blown into the reactor at 70 ° C. at 27 g of methyl methacrylate, 27 g of n-butyl methacrylate, and 5 g of toluene.
4 g of the mixture were charged over 30 minutes. This was heated at 70 ° C. for 5 hours and at 80 ° C. for 3 hours to carry out a polymerization reaction. As a result of measuring the polymerization conversion of the obtained polymer, the polymerization conversion was 97%, and the content of the polysiloxane group-containing monomer in the polymer was 51% by weight.

(C) Preparation of antifouling underwater coating agent The obtained AB type block copolymer was dissolved in xylene so as to have a solid content of 30% by weight. Used as

Example 8 In Example 7 (A), the polysiloxane group-containing monomer represented by the above formula (8) was replaced by 40 g of the polysiloxane group-containing monomer represented by the above formula (6) and the formula (6) An AB block copolymer was synthesized under the same conditions as in Example 7 except that the composition was changed to 40 g of the polysiloxane group-containing monomer shown in 8), and used as an underwater antifouling coating agent.
The solid content after completion of the polymerization was 39.2% by weight.

Example 9 A vinyl chloride resin (manufactured by Riken Vinyl) was treated with 2-butanone for 3
After adjusting to be 0% by weight, the AB block copolymer of Example 1 was added to the vinyl chloride resin at 10% by weight.
What was added was used as an underwater antifouling coating agent.

Example 10 The AB block copolymer of Example 9 was replaced with the A-block copolymer of Example 2.
Except for changing to the B-type block copolymer, the one obtained under the same conditions as in Example 9 was used as an underwater antifouling coating agent.

Comparative Example 1 KE45S (manufactured by Shin-Etsu Chemical Co., Ltd.) diluted with xylene so as to have a solid content of 30% by weight as a reaction-curable silicone rubber was used as an underwater antifouling coating agent.

Comparative Example 2 In a reactor equipped with a thermometer, a stirrer and a reflux condenser, 2-
While charging 57 g of butanone, 6 while blowing nitrogen gas.
Heated to 5 ° C. In addition, 57 g of 2-butanone, 48 g of methyl methacrylate, and 32 g of the polysiloxane-containing monomer (number average molecular weight = 10000) shown in the above (6)
And 1 g of perbutyl pivalate were charged over 2 hours, and a polymerization reaction was further carried out for 8 hours to obtain a polysiloxane group-containing graft copolymer. The solid content of the obtained graft copolymer was 40.5% by weight, and the solid content adjusted to 30% by weight with 2-butanone was used as an antifouling coating in water. Examples 1 to 1 above
0 and the underwater antifouling coatings of Comparative Examples 1 and 2 were subjected to the following antifouling performance test and adhesion test, and the results are shown in Table 1.

<Antifouling performance test> Each of the underwater antifouling coatings was coated on both sides of a coated plate (100 mm x 200 mm x 1 mm) obtained by applying a tar vinyl-based anticorrosive paint to a sand-plast treated steel sheet in advance. Was spray-coated twice so as to have a thickness of 120 μm on one side, and then naturally dried at room temperature for 7 days to prepare a test plate. This test plate was immersed in seawater for 24 months in Yura Bay, Sumoto City, Hyogo Prefecture, and the area occupied by the attached organisms on the test plate was determined using the following evaluation criteria. A: No adhesion of organisms to the coating film was observed. ：: Adhesion of organisms is observed on a part of the coating film. Δ: Biological adhesion is observed on about half of the coating film. ×: Adhesion of organisms is observed on the entire surface of the coating film.

<Adhesion Test> Using the coated plate of the above test, the coating film adhesion test immediately after application (initial stage) and after immersion in seawater for 24 months was evaluated based on a JIS K5400.8.5 cross-cut peel test. did. The evaluation criteria are shown below. ：: No peeling of the coating film was observed. Δ: Peeling is observed in a part of the coating film. ×: Exfoliation is observed in most of the coating film.

[0062]

[Table 1]

From the results in Table 1 above, Examples 1 to 10 are 2
Even after 4 months, there is no adhesion of organisms, and it is clear that the underwater antifouling coating composition of the present invention retains excellent antifouling properties over a long period of time. In contrast, in Comparative Example 1, the adhesion of organisms was already observed after 3 months, and in Comparative Example 2, although the antifouling property was observed, it was clarified that the coating film adhesion was insufficient. .

[0064]

The underwater antifouling coating composition of the present invention comprises an A-polymer comprising a polysiloxane group-containing graft copolymer segment A and a polymer segment B containing no polysiloxane group.
Since the B-type block copolymer is a main component and the polysiloxane group forming the polysiloxane group-containing graft copolymer segment A in the A-B type block copolymer has a low surface tension, the surface is selectively treated. And the initial antifouling property can be exhibited. Further, in the polymer segment B containing no polysiloxane group, by using a vinyl monomer in consideration of adhesion to a substrate to be coated and affinity when mixed into a general-purpose coating, A- Since the falling off of the B-type block copolymer can be prevented, long-term antifouling durability can be exhibited. Therefore, it is extremely useful for surface coating of ship bottoms, underwater structures, fishing nets, various suction and drain pipes for cooling, and the like.

Claims (2)

[Claims] 1. A polysiloxane group-containing graft copolymer formed from one or two or more monomers represented by the following general formula (1) or (2) and one or two or more vinyl monomers. An underwater antifouling coating agent containing an AB block copolymer comprising a polymer segment A and a polymer segment B containing no polysiloxane group and formed of one or more vinyl monomers. . Embedded image [Wherein, R ¹ is a hydrogen atom or a methyl group, R ² is a methyl group,
An ethyl group, a phenyl group or the following formula (a): (Wherein, R ⁵ is a hydrogen atom, a phenyl group, or C _P H
_{2P + 1} (P is an integer of 1 to 10), R ⁶ is a methyl group, an ethyl group, a phenyl group, and m is an integer of 1 or more. ), R ³
Is a hydrogen atom, a phenyl group or C _Q H _{2Q + 1} (Q is 1 to 10
Of an integer), R ⁴ is a methyl group, an ethyl group, a hydroxyl group or a phenyl group,, n is an integer of 1 or more. ] In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is a methyl group, an ethyl group, a phenyl group or the following formula (a): (Wherein, R ⁵ is a hydrogen atom, a phenyl group, or C _P H
_{2P + 1} (P is an integer of 1 to 10), R ⁶ is a methyl group, an ethyl group, a phenyl group, and m is an integer of 1 or more. ), R ³
Is a hydrogen atom, a phenyl group or C _Q H _{2Q + 1} (Q is 1 to 10
), And n is an integer of 1 or more. ] 2. An underwater antifouling coating comprising a general-purpose paint and the AB block copolymer according to claim 1.