JPH10316933A - Antifouling painting composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nontoxic antifouling painting compsn. which, when applied to the surface of an underwater structure, can form an antifouling coating film which can inhibit aquatic organisms from depositing and growing on the surface for a long term. SOLUTION: This compsn. contains a room-temp.-curable silicone rubber (A) having a number average mol.wt. of 20,000-100,000, a room-temp.-curable silicone rubber (B) having a number average mol.wt. of 250-20,000, and a silicone oil (C) as the main ingredients in a ratio of ingredient A to ingredient B of (5/95)-(95-5) and further contains a hydrophobic fumed silica (D) in an amt. of 5-30 wt.% of the sum of ingredients A and B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-toxic antifouling paint composition containing no toxic antifouling agent, and more particularly, to ships, port facilities, buoys, pipelines, bridges, headrace pipes of power plants,
An antifouling coating that can be applied to submarine bases, offshore oilfield drilling equipment, aquaculture nets, stationary nets, etc. (hereinafter collectively referred to as "underwater structures") to prevent the underwater organisms from adhering and growing on these surfaces for a long time. The present invention relates to an antifouling paint composition for forming a film.

[0002]

2. Description of the Related Art A large number of organisms such as barnacles, sea squirts, serpula, purple mussels, mussels, fir tree mosses, aonori and aosa live in the waters of the sea, rivers, lakes and marshes. When an underwater structure is set up or in service, organisms adhere and grow from the splashed portion to the surface of the submerged portion, causing various damages.

[0003] In order to prevent underwater organisms from adhering to such underwater structures, an antifouling paint containing a toxic antifouling agent such as an organotin compound has conventionally been used. Although the antifouling paint is very excellent in antifouling properties, it is highly toxic, and has problems in environmental protection and health and safety. Therefore, as a non-toxic antifouling paint, Silicon-
An antifouling paint comprising a rubber alone or a mixture of a silicone rubber and a silicone oil is disclosed in, for example, JP-A-51-968.
No. 30, JP-B-56-26272, JP-A-63-43
973 and JP-A-3-255169.

[0004] In the antifouling paint, the combined use of silicone rubber and silicone oil has remarkably improved the effect of preventing the adhesion of underwater organisms as compared with the silicone rubber alone, but it has been over a long period of one year or more. It did not last long.

Further, in an antifouling paint composed of silicone rubber alone or a mixture of silicone rubber and silicone oil, the antifouling property and storage stability can be maintained even when hydrophobic fumed silica or a thixotropic agent is added. Without affecting the quality and without causing problems such as sagging during painting.
It was difficult to form a thick film having a thickness of not less than a micron (dry film thickness). Therefore, there has been a demand for the development of an antifouling paint which has an excellent antifouling effect, can maintain this for a long period of time, and can form a thick film.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, have found that two kinds of silicone rubbers having a specific molecular weight are used in a specific range and used in combination with silicone oil. As a result, the present inventors have found that a function layer (antifouling function layer) made of silicone oil can be uniformly formed on the surface of the coating film, the antifouling performance can be maintained for a long time, and a thick film can be formed.

That is, the present invention provides (a) a number average molecular weight of 20,
Room temperature-curable silicone rubber having a number average molecular weight of 500 to 20,000 (b) and a silicone oil (c) as a main component. An antifouling coating composition characterized in that the solid content ratio of the rubber (a) and the silicone rubber (b) is 5/95 to 95/5.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The silicone rubber (a) used in the present invention can be cured by a chemical reaction at room temperature (about 80 ° C. or lower) and contains an organopolysiloxane having a siloxane bond as a main component. , Number average molecular weight 20,000-10
000 silicone rubber. The organopolysiloxane has a curing-reactive functional group and an organic group directly bonded to Si. Examples of the curing-reactive functional group include a hydroxyl group and an alkoxy group having 1 to 5 carbon atoms. Group, ethyl group, vinyl group, haloalkyl group, phenyl group and the like.

The silicone rubber (a) includes those obtained by adding a crosslinking agent and a curing catalyst to the above-mentioned organopolysiloxane, if necessary.

Examples of the crosslinking agent include polyfunctional silane compounds having a hydrolyzable group (eg, acetoxy group, ketoxime group, etc.), for example, methyl-tris (methylethylketoxime) silane, vinyl-tris (methylethylketoxime) silane, (Methyl ethyl ketoxime silane) silane, methyl trimethoxy silane, methyl triacetoxy silane, tetraethoxy silane, methyl tri (N, N-diethylamino) silane and the like, and partially hydrolyzed products thereof.

Examples of the curing catalyst include dibutyltin diacetate, dibutyltin dioctate, dibutyltin dilaurate, dioctyltin dilaurate, zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, Organometallic catalysts such as zirconium naphthenate, tetrabutylortho titanate, diethanolamine,
Examples thereof include amine catalysts that do not contain an organosilicon compound such as triethanolamine.

The above silicone rubber (a) can be cured by hydrolysis, dealcohol, deacetic acid, deoxime, dehydroxylamine, etc. at room temperature or by heating. When a material having a polymerizable unsaturated group such as a vinyl group is used as the organopolysiloxane, it can be cured by irradiation with an electron beam or ultraviolet rays. In the case of ultraviolet irradiation, it is necessary to add a photopolymerization initiator.

[0013] The silicone rubber (a) has a number average molecular weight of 20,000 to 100,000, preferably 20,000.
When it is in the range of 000 to 60,000, and when it is less than 20,000, the strength of the obtained antifouling coating film becomes insufficient. It is not preferable.

The silicone rubber (b) used in the present invention
Is a low molecular weight silicone rubber having a number average molecular weight of 500 to 20,000, which can be cured by a chemical reaction at room temperature (about 80 ° C. or lower) and contains an organopolysiloxane having a siloxane bond as a main component. The organopolysiloxane has a curing-reactive functional group and an organic group directly bonded to Si. Examples of the curing-reactive functional group include a hydroxyl group and an alkoxy group having 1 to 5 carbon atoms. Group, ethyl group, vinyl group, haloalkyl group, phenyl group and the like.

As the silicone rubber (b), similarly to the silicone rubber (a), an organopolysiloxane may be added, if necessary, to a crosslinking agent and a curing agent as described in the description of the silicone rubber (a). It also includes those containing a catalyst and the like, and is cured by hydrolysis, de-alcohol, de-acetic acid, de-oxime, de-hydroxylamine reaction or the like at room temperature or by heating.

The silicone rubber (b) has a number average molecular weight of 500 to 20,000, preferably 2,000 to 1,
If it is out of this range, a function layer (antifouling function layer) made of silicone oil cannot be formed uniformly on the surface layer of the coating film, and the antifouling performance cannot be maintained for a long period of time.

In the present invention, the silicone rubber (a) and the silicone rubber (b) are mixed in a solid content ratio of 5/95 to 95/95.
5, preferably 20/80 to 80/20. If the amount of the silicone rubber (a) is less than this range, the resulting coating film is too hard to obtain long-term antifouling performance, whereas if the amount of the silicone rubber (b) is small, the surface of the coating film has an antifouling function layer. Is not preferable because it cannot be formed uniformly. When a thick film is formed by one coating, the silicone rubber (a) and the silicone rubber (b) are mixed at a solid content ratio of 20/8.
It is suitable to mix at 0 to 80/20, preferably 30/70 to 70/30. Outside this range, even if a hydrophobic fumed silica or a thixotropic agent is added, good thixotropic properties cannot be obtained, and it becomes difficult to form a thick film, which is not preferable.

In the present invention, the hydrophobic fumed silica (d) is used as a filler in an amount of 5 to 30 parts by weight, preferably 5 to 30 parts by weight, based on the total solids of the silicone rubbers (a) and (b). Can be contained in an amount of 10 to 25 parts by weight. If the content is less than 5 parts by weight, good thixotropic properties cannot be obtained, and it is difficult to form a thick film. On the other hand, if the content exceeds 30 parts by weight, the paint viscosity becomes too high to be applied, and the paintable viscosity Until thinner is used, it becomes difficult to form a thick film.

The hydrophobic fumed silica (d) is usually surface-treated with (hydroxyl-containing) dimethylpolysiloxane or dimethyldichlorosilane, and further surface-treated with hexamethyldisilazane or cyclic dimethylsiloxane. There may be. Precipitated silica, quartz, diatomaceous earth and the like may be used in combination as other fillers, and those subjected to hydrophobic treatment are preferable from the viewpoint of storage stability.

In the present invention, the silicone rubbers (a) and (b) are further compounded with an organopolysiloxane composition containing hydrophobic fumed silica (d) and a silicone oil (c).

In the present invention, the silicone oil (c)
Has no reactivity or self-condensability with the silicone rubbers (a) and (b), and forms an antifouling function layer on the surface of the coating film. As the silicone oil (c), conventionally known ones can be used without any particular limitation. For example, at least one or more selected from silicone oils represented by the following general formulas (I) or (II) can be used. . In particular, it is desirable that the silicone oil (c) is somewhat incompatible with the organopolysiloxanes contained in the silicone rubbers (a) and (b). Those selected from the silicone oils represented by I) are preferred.

[0022]

Embedded image

Wherein R ¹ is the same or different and represents a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group or a fluoroalkyl group, and R ² is the same or different and has the same number of carbon atoms. 1 to 10 alkyl groups, aryl groups,
Represents an aralkyl group or a fluoroalkyl group, and n is 0 to
Represents an integer of 150. )

[0024]

Embedded image

(In the formula, R represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, or an aralkyl group, and R 'represents an ether group, an ester group, or -NH-. And a good divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, and Z is an amino group, a carboxy group, an epoxy group, or a polyethylene glycol whose terminal may be blocked with an alkyl group or an acyl group having 1 to 6 carbon atoms. And x and y represent 0.01 ≦ x <3.99, 0.01 ≦ y <3.99 and 0.02 ≦ x + y <, respectively. 4.) as R ¹ in the general formula (I) include a methyl group, a phenyl group, preferably a hydroxyl group, examples of R ^2, a methyl group, a phenyl group, such as 4-trifluoromethyl-butyl group.

The silicone oil represented by the above general formula (I) has a number average molecular weight of 180 to 20,000,
Preferably 1,000-10,000, viscosity 10-1
000 centistokes, preferably 100 to 5,
000 centistokes - what is box are suitable, specifically, terminal hydroxyl group-containing dimethyl silicone R ¹ in both ends or one end is a hydroxyl group - N'oiru, dimethylsiliconate all of R ¹ and R ² is a methyl group And phenylmethylsilicone oil in which some of the methyl groups of these dimethylsilicone oils are substituted with phenyl groups.

R in the general formula (II) is typically a methyl group or a phenyl group, and R 'includes methylene, ethylene, propylene and the like. In the polyethylene glycol or polypropylene glycol group which may be blocked with an alkyl group or an acyl group, the number of repeating units of oxyalkylene which is oxyethylene or oxypropylene is suitably from 10 to 60. Examples of the alkyl group having 6 or less carbon atoms when the terminal is blocked include a methyl group, an ethyl group, and a butyl group, and an acyl group having 6 or less carbon atoms when the terminal is blocked is an acetyl group.
And a propionyl group.

The silicone oil represented by the general formula (II) includes a number average molecular weight of 250 to 30,000,
Preferably 1,000 to 20,000, viscosity 20 to 5
000 centistokes, preferably 100 to 5,
2,000 centistokes is suitable. Specifically, when the polar group Z is an amino group, for example, SF8417
(Toray Dow Corning Silicone Co., Ltd.) and ISI47
00, ISI4701 (product of Toshiba Silicone), FZ
3712 and AFL-40 (manufactured by Nihon Unica Co., Ltd.). When the polar group Z is a carboxyl group, for example, X
I42-411 (Toshiba Silicon Corporation product), SF841
8 (product of Toray Downconing Silicone Co., Ltd.), FXZ3
707 (manufactured by Nippon Unicar Co., Ltd.). When the polar group Z is an epoxy group, for example, SF8411 (manufactured by Toray Downconing Silicone Co., Ltd.), ISI 4730,
XI42-301 (product of Toshiba Silicon Corporation), L-93
00 and T-29 (products of Nippon Unicar Ltd.).

Further, when the polar group Z is a polyethylene glycol or polypropylene glycol group which may be blocked with an alkyl group or an acyl group, for example, IS
I4460, ISI4445, ISI4446 (product of Toshiba Silicon Corporation), SH3746, SH8400, SH
3749, SH3700 (Toray Dow Corning Silicone)
Products) and KF6009 (manufactured by Shin-Etsu Silicone Co., Ltd.).

The content of the silicone oil (c) is as follows:
30 to 200 parts by weight, preferably 50 to 1 part by weight, based on 100 parts by weight of the total solid content of the silicone rubbers (a) and (b)
A range of 50 parts by weight is suitable. If the content of the silicone oil (c) is less than 30 parts by weight, long-term antifouling performance cannot be obtained, and if it exceeds 200 parts by weight, the strength of the resulting coating film is reduced and the antifouling property cannot be maintained. . Further, when a thick film is formed by one coating, the content of the silicone oil (c) is 30 to 150 parts by weight based on 100 parts by weight of the total solid content of the silicone rubbers (a) and (b).
Suitably, the amount is in the range of 50 parts by weight, preferably 50 to 120 parts by weight. If it exceeds 150 parts by weight, it may be difficult to form a thick film, which is not preferable.

The antifouling coating composition of the present invention may further contain, if necessary, chlorinated paraffin, solid paraffin, liquid paraffin, petrolatum, etc. in addition to the above resin component.
It can be added in an amount of about 10 parts by weight or less, preferably 9 parts by weight or less based on 00 parts by weight. Further, if necessary, pigments such as coloring pigments, extender pigments and rust-preventive pigments, organic solvents, plasticizers, anti-sagging agents, silane coupling agents, antifouling agents and the like can be appropriately compounded.

The antifouling paint composition of the present invention can be used for underwater structures such as ships, port facilities, buoys, pipelines, bridges, headraces of power plants, submarine bases, offshore oilfield drilling equipment, aquaculture nets, and stationary nets. It is painted and prevents long-term underwater organisms from attaching and growing on these surfaces. The antifouling paint can be applied once or a plurality of times by a conventionally known means.

[0033]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to Examples. Note that “parts” and “%” are based on weight unless otherwise specified.

Preparation of Organopolysiloxane Composition As shown in Table 1, 100 parts of a combination of silicone rubbers having different number average molecular weights were combined with a hydrophobic hull surface-treated with hydroxyl group-containing dimethylpolysiloxane or dimethyldichlorosilane. Mudosilica was blended in the blending amount shown in Table 1, and mixed and dispersed with a stirring mixer so as to be uniform. Then, the crosslinking agent and curing catalyst shown in Table 1 were blended in the absence of moisture and mixed uniformly. Thus, room temperature curable organopolysiloxane compositions A to K were prepared. In addition, (note 1)-in Table 1
(Note 5) is as follows.

(Note 1) Silicone rubber (a-1): an organopolysiloxane having a number average molecular weight of 50,000 and containing a silanol group and / or an alkoxysilyl group (Note 2) Silicone rubber (a-2) ): Number average molecular weight 3
Organopolysiloxane containing 0000, silanol group and / or alkoxysilyl group (Note 3) Silicone rubber (b-1): number average molecular weight 3,
000, organopolysiloxane containing silanol and / or alkoxysilyl groups (Note 4) Silicone rubber (b-2): number average molecular weight 1
Organopolysiloxane containing 0000, silanol group and / or alkoxysilyl group (Note 5) Hydrophobic fumed silica: manufactured by Toray Dow Corning Silicone Co., Ltd.

[0036]

[Table 1]

Examples 1 to 5 and Comparative Examples 1 to 7 To 100 parts of each of the organopolysiloxane compositions obtained above, each silicone oil was mixed in the composition shown in Table 2, and xylene was added to adjust the viscosity. Each antifouling paint was obtained. The following antifouling test was performed for each antifouling paint. Table 3 shows the results
Shown in

(Note 6) to (Note 10) and antifouling test methods in Table 1 are as follows.

(Note 6) KF6009: Polyethylene glycol-modified silicone oil, manufactured by Shin-Etsu Silicone Co., Ltd. (Note 7) KF50: Diphenyl silicon oil, manufactured by Shin-Etsu Silicone Co., Ltd. (Note 8) SH3746: Polyethylene glyco- (Note 9) FZ3712: Amino group-modified silicone oil, manufactured by Nippon Unicar (Note 10) KF96: Dimethyl silicon oil, manufactured by Shin-Etsu Silicone Co., Ltd. Soil test method: A zinc-rich epoxy resin-based shop primer paint was applied to a sandblasted steel sheet having a size of 100 × 300 × 2 mm and a dry film thickness of 15 μm, and an epoxy resin-based anticorrosion paint was applied to a dry film thickness of 200 μm. The antifouling paint obtained in each example was used as an object to be coated, and the dry film thickness was about 150 μm. After the formation of the antifouling coated plate by sea urchin brush painting and drying, the suspension Hitaumi test in this coated plate was carried out 24 months in Orito Bay (Shizuoka Prefecture Shimizu City), it was carried out visually observed.

[0040]

[Table 2]

[0041]

[Table 3]

Examples 6 to 10 and Comparative Examples 8 to 12 100 parts of each of the organopolysiloxane compositions obtained above were mixed with the respective silicone oil and xylene in the composition shown in Table 4 to obtain each antifouling paint. Was. The viscosity (poise) of each of the obtained antifouling paints was measured with a B-type viscometer (No. 3 rotor). I. The value was calculated from the following equation.

T. I. Value = (viscosity at 6 rpm)
/ (Viscosity at 60 rpm) Table 4 shows these paint property values and coating workability. In addition, (Note 11), (Note 12), and the coating workability test in Table 4 are as follows.

The antifouling test was performed on each antifouling paint. Table 5 shows the results.

(Note 11) SH510: methylphenyl silicone oil, manufactured by Shin-Etsu Silicone Co., Ltd. (Note 12) X22-4822: polyethylene glycol-modified silicone oil, manufactured by Shin-Etsu Silicone Co., Ltd. After providing a 100 × 1000 band-shaped masking on a 1000 × 1000 × 1 mm mild steel plate,
Epoxy resin heavy-duty anticorrosive paint is applied on the entire surface to dry thickness of 100μm
The coated plate from which the coating and the masking were removed was used as an object to be coated, and the antifouling paint obtained in each example was gradually thickened to a thickness of about 60 to 400 μm (assumed to be 40 to 250 μm when dried) in order from the end. Using an airless coating machine, inclined coating was performed, and the resulting coated plate was vertically stood and dried. After drying, the film thickness before and after the location where sagging occurred was measured in a portion where the epoxy resin-based heavy anticorrosive paint was not applied.

[0046]

According to the present invention, by using two types of silicone rubber having a specific molecular weight in a specific range and using the same together with a silicone oil, the surface of the coating film obtained is stain-proofed with the silicone oil. The functional layer can be formed uniformly, and the antifouling performance can be maintained for a long time. In addition, when two types of silicone rubbers having specific molecular weights are used together in a specific range as described above, the structural viscosity of the hydrophobic fumed silica can be more easily developed and a thick film can be easily formed.

[0047]

[Table 4]

[0048]

[Table 5]

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Toshimitsu Muramatsu 3-12-1, Minamirokugo, Ota-ku, Tokyo Kansai Paint Co., Ltd. (72) Inventor Yoichi Yonehara 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Seki Nishi Paint Co., Ltd.

Claims (4)

[Claims] (A) a number average molecular weight of 20,000 to 10
000 room temperature curable silicone rubber, (b) a room temperature curable silicone rubber having a number average molecular weight of 500 to 20,000, and (c) silicone oil as main components. An antifouling paint composition characterized in that the solid content ratio between a) and the silicone rubber (b) is 5/95 to 95/5. 2. The antifouling coating composition according to claim 1, wherein the solid content ratio of the silicone rubber (a) to the silicone rubber (b) is 20/80 to 80/20. 3. The method according to claim 1, wherein the hydrophobic fumed silica (d) is contained in an amount of 5 to 30 parts by weight in terms of solids based on 100 parts by weight of the total solids of the silicone rubbers (a) and (b). The antifouling paint composition according to the above. 4. The antifouling coating composition according to claim 1, wherein the silicone oil (c) is represented by the following general formula (I). Embedded image (In the formula, R ¹ is the same or different and has a hydroxyl group, a carbon number of 1 to
10 represents an alkyl group, an aryl group, an aralkyl group or a fluoroalkyl group; R ² is the same or different and represents an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group or a fluoroalkyl group; n represents the number of 0-150. )