WO2024185319A1 - Room-temperature-curable organopolysiloxane composition and base material - Google Patents

Abstract

Provided is a room-temperature-curable organopolysiloxane composition containing, at a specific ratio, (A) organopolysiloxane having a viscosity μ_(A) of 100 to 100,000 mPa•s at 25°C, represented by formula (1): (1): HO - (SiR¹ ₂O)_a - H (where R¹ is an independently unsubstituted or substituted monovalent hydrocarbon group having a carbon number from 1 to 10, and a is an integer of 50 or greater), (B) a hydrolyzable organosilane compound and/or a partial hydrolytic condensation thereof represented by formula (2): (2) (where R² is a monovalent hydrocarbon group having a carbon number from 1 to 10, n is any integer from 1 to 8, and m is 3 or 4), (C) a curing catalyst (excluding organotin compounds), and (D) a bleed oil. The room-temperature-curable organopolysiloxane composition is free of organotin compounds, which are problematic in terms of environmental safety and hygiene, does not generate methylethyl ketone oxime (MEKO) during curing, and has excellent rapid curing properties. Furthermore, the cured coating film obtained is excellent in rubber strength and surface smoothness and demonstrates excellent antifouling performance for a long period of time.

Description

Room temperature curable organopolysiloxane composition and substrate

The present invention relates to a room-temperature curable organopolysiloxane composition suitable as a coating agent for substrates such as underwater structures and ships, and to substrates coated with a cured product of this composition.

Conventionally, various room temperature curable silicone rubber compositions have been known that undergo a condensation reaction with moisture in the air at room temperature (usually 25°C ± 10°C) to crosslink and cure to give a rubber elastic body (cured silicone rubber product). The rubber (silicone rubber) obtained from room temperature curable silicone rubber compositions (hereinafter referred to as RTV silicone rubber compositions) has excellent weather resistance, durability, heat resistance, cold resistance, etc. compared to other hydrocarbon-based organic rubbers, and is therefore used in various fields, particularly in the construction field, where it is widely used for bonding glass to glass, bonding metal to glass, sealing concrete joints, etc. In recent years, it has also become widely used as a coating material for buildings, plants, the inner and outer surfaces of water pipes, etc. Furthermore, in the electrical and electronic fields, it is also used as a coating material for liquid crystal peripherals and power circuit boards, the demand for which has been rapidly increasing in recent years.

When underwater structures or ships are installed or put into service, aquatic organisms that live in the waters of the sea, rivers, etc., such as barnacles, oysters, sea squirts, serpula, mussels, mussels, moss animals, green laver, and sea lettuce, attach and grow on the splash areas and submerged surfaces of the structures, causing various damages. For example, when these organisms attach to the hull of a ship, etc., frictional resistance with the water increases and the sailing speed decreases, which increases fuel consumption to maintain a certain speed, which is economically disadvantageous. In addition, when organisms attach to structures (underwater structures) that are fixed to the water or water surface of port facilities, etc., it becomes difficult for these structures to fully perform their individual functions, and they may even erode the base material. Furthermore, when organisms attach to aquaculture nets, fixed nets, etc., the meshes can become clogged and fish can die.

　Measures to prevent the attachment and growth of aquatic organisms on underwater structures and ships have been implemented by painting the structures with antifouling paints containing toxic antifouling agents such as organotin compounds and cuprous oxide. Although this has been successful in preventing the attachment and growth of aquatic organisms, the use of toxic antifouling agents is undesirable from the standpoint of environmental safety and health during the manufacture and application of the paint, and the toxic antifouling agents gradually leach out of the paint film in water, posing the risk of polluting waters in the long term. As a result, its use has been legally prohibited.

Therefore, a non-toxic antifouling paint composition was proposed that contains liquid paraffin or petrolatum in an RTV silicone rubber composition that can reduce the surface tension of the coating film and provide antifouling properties, as a paint that prevents the attachment and growth of aquatic organisms and does not contain a toxic antifouling agent (JP Patent Publication No. 58-13673: Patent Document 1, JP Patent Publication No. 62-84166: Patent Document 2). However, because hydrocarbon-based bleed oils such as liquid paraffin and petrolatum have extremely low compatibility with silicone, there is a drawback in that the antifouling performance decreases within a short period of time. In addition, a non-toxic antifouling paint composition has also been proposed in which the volume shrinkage associated with the curing of the reactive curing silicone resin causes the poorly compatible and non-reactive polar group-containing silicone resin to bleed to the surface, and in combination with the low surface tension of the reactive curing silicone resin, it exhibits antifouling properties (JP Patent Publication No. 2503986: Patent Document 3, JP Patent Publication No. 2952375: Patent Document 4). However, the non-toxic antifouling paint composition uses oil-bleeding of silicone resins containing polyoxyethylene groups in which ethylene oxide, propylene oxide, etc. are attached to the Si atom via a C-C bond as the poorly compatible and non-reactive polar group-containing silicone resin, or silicone resins in which alkoxy groups have been introduced to the molecular terminals via ethylene oxide or propylene oxide groups attached to the Si atom, resulting in problems with environmental safety and health.

Moreover, most of the RTV silicone rubber compositions contained in conventional antifouling paint compositions are moisture-curing types, with the majority being oxime-curing types. The reasons for this include the fact that good curing can be achieved without the use of harmful organotin catalysts, and that the strength of the cured film is high. However, since oxime-curing types generate methyl ethyl ketoxime (MEKO) during curing, they tend to be avoided in the antifouling paint market, mainly in Europe, due to concerns about the burden on the environment. It is possible to prevent the generation of MEKO with alcohol-curing types, but alcohol-curing types generally require organotin compounds as a curing catalyst. Furthermore, alcohol-curing types cure more slowly than oxime-curing types, so when used as antifouling paints, workability may decrease.

Therefore, there is a global demand for RTV silicone rubber compositions that do not generate MEKO during curing, do not contain organotin compounds, and have excellent fast-curing properties and can be used as antifouling paints.

Japanese Unexamined Patent Publication No. 58-13673 Japanese Patent Application Laid-Open No. 62-84166 Patent No. 2503986 Patent No. 2952375

The present invention has been made in consideration of the above circumstances, and aims to provide a room-temperature curable organopolysiloxane composition that does not contain organotin compounds that are problematic in terms of environmental safety and health, and that is of a curing type that does not generate MEKO during curing, which is often avoided in the antifouling paint market, yet has excellent fast curing properties, and the resulting cured coating film has excellent rubber strength and exhibits excellent antifouling performance for a long period of time, as well as a substrate coated (covered) with the cured product of said composition.

The inventors conducted extensive research to achieve the above-mentioned objective, and as a result, discovered that room-temperature curable organopolysiloxane compositions have no reported health hazards, such as carcinogenicity or reproductive toxicity to the human body, or environmental hazards, such as toxicity to aquatic organisms, and that by using a hydrolyzable organosilane compound with a cyclic ketone compound, such as cyclobutanone or cyclopentanone, as a leaving group (leaving compound), which has a relatively high flash point, as a curing agent, it is possible to prepare a room-temperature curable organopolysiloxane composition that does not generate MEKO during curing and does not contain organotin compounds, and that this composition has excellent fast-curing properties, and further, by blending a specific bleed oil, the cured coating film obtained has excellent rubber strength and surface smoothness, and exhibits excellent anti-fouling performance for a long period of time, which led to the creation of the present invention.

Accordingly, the present invention provides the room temperature curable organopolysiloxane composition described below, and a substrate coated with the cured product of this composition.
[1]
A room-temperature curable organopolysiloxane composition comprising the following components (A) to (D):
(A) 100 parts by mass of an organopolysiloxane having a viscosity μ _(A) at 25° C. of 100 to 100,000 mPa·s, which is represented by the following general formula (1):
HO-(SiR ¹ ₂ O) _a -H (1)
(In the formula, R ¹ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and each R ¹ may be the same or different. a is an integer of 50 or more.)
(B) a hydrolyzable organosilane compound represented by the following general formula (2) and/or a partial hydrolysis condensate thereof: 1 to 40 parts by mass,

(In the formula, ^R2 is a monovalent hydrocarbon group having 1 to 10 carbon atoms, n is an integer from 1 to 8, and m is 3 or 4.)
(C) a curing catalyst (excluding organotin compounds): 0.001 to 10 parts by mass, and (D) a bleed oil: 0.01 to 100 parts by mass.
[2]
The room-temperature-curable organopolysiloxane composition according to [1], wherein the hydrolyzable organosilane compound and/or partial hydrolysis condensate thereof of component (B) is one that releases a cyclic ketone compound by hydrolysis.
[3]
The room-temperature-curable organopolysiloxane composition according to [2], wherein the cyclic ketone compound that is eliminated is cyclobutanone or cyclopentanone.
[4]
The room-temperature-curable organopolysiloxane composition according to any one of [1] to [3], wherein the viscosity μ _(D) of component (D) at 25° C. is 20 to 30,000 mPa·s.
[5]
The room-temperature-curable organopolysiloxane composition according to any one of [1] to [4], wherein the ratio of the viscosity μ _{(D) of} component (D) at 25°C to the viscosity μ(A) of component (A) at 25°C [μ _(D) /μ _(A) ] is 0.05 to 1.
[6]
Further, for every 100 parts by mass of the component (A),
The room-temperature-curable organopolysiloxane composition according to any one of [1] to [5], further comprising one or more selected from the group consisting of (E) a filler: 1 to 100 parts by mass, and (F) an adhesion promoter: 0.1 to 20 parts by mass.
[7]
The room-temperature-curable organopolysiloxane composition according to any one of [1] to [6], which is used for coating underwater structures or ships.
[8]
A substrate coated with a cured product of the room-temperature-curable organopolysiloxane composition according to any one of [1] to [7].
[9]
The substrate according to [8], which is an underwater structure or a ship.

The room temperature curable organopolysiloxane composition of the present invention does not contain organotin compounds which are useful as curing catalysts but have environmental, safety and hygiene problems, and has excellent fast curing properties while being a curing type that does not generate MEKO during curing, which is often avoided in the antifouling paint market, and the resulting cured coating film has excellent rubber strength, and when used as an antifouling paint, it exhibits excellent antifouling performance for a long period of time. It is particularly suitable for application to underwater structures, ships, etc., to prevent the attachment and growth of aquatic organisms on the substrate surfaces of underwater structures, ships, etc., and the effect is well sustained.
That is, the coating film obtained from the room temperature curable organopolysiloxane composition of the present invention is non-toxic, and when the coating film is provided on the surface of a substrate such as an underwater structure or a ship, it prevents the attachment and growth of aquatic organisms for a long period of time, and exhibits excellent antifouling properties. Therefore, the room temperature curable organopolysiloxane composition of the present invention is highly suitable for applications such as coating materials requiring water resistance, such as ship bottom paints, paints for seawater inlet pipes to power plants, and fishnet paints, moisture-proof coating materials requiring moisture resistance, such as LCDs and PDPs, adhesive seals between electric wires and resin coatings, adhesive seals between resin cases or resin connectors and electric wires, and adhesive seals for reduced pressure or pressurized chambers, and is particularly useful as ship bottom paints, paints for seawater inlet pipes to power plants, and fishnet paints, for preventing the attachment and growth of aquatic organisms on the surfaces of these materials.

The present invention will now be described in further detail.
<Room-temperature-curable organopolysiloxane composition>
The room-temperature-curable organopolysiloxane composition of the present invention is characterized by containing the following components (A) to (D):

[Component (A): Organopolysiloxane]
Component (A) used in the room temperature curable organopolysiloxane composition of the present invention is an organopolysiloxane represented by the following general formula (1) and having a viscosity μ _(A) at 25° C. of 100 to 100,000 mPa·s.
HO-(SiR ¹ ₂ O) _a -H (1)
(In the formula, R ¹ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and each R ¹ may be the same or different. a is an integer of 50 or more.)

Component (A) is a linear diorganopolysiloxane having a main chain consisting of repeating diorganosiloxane units as shown in formula (1), both ends of the molecular chain being blocked with hydroxyl groups (silanol groups) bonded to silicon atoms, and having a viscosity μ _(A) of 100 to 100,000 mPa s at 25°C. It functions as the main agent (base polymer) of the room-temperature-curable organopolysiloxane composition of the present invention.

In the above formula (1), R ¹ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, particularly 1 to 6 carbon atoms, such as alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, 2-ethylhexyl, nonyl, and decyl, cycloalkyl groups such as cyclohexyl, alkenyl groups such as vinyl, allyl, propenyl, isopropenyl, butenyl, and hexenyl, aryl groups such as phenyl and tolyl, and aralkyl groups such as benzyl and phenylethyl. Alternatively, the hydrogen atoms of these hydrocarbon groups may be partially substituted with halogen atoms such as chlorine, fluorine, and bromine, such as a trifluoropropyl group. The unsubstituted or substituted monovalent hydrocarbon group of ^R1 is preferably one that does not contain an aliphatic unsaturated bond, more preferably an alkyl group such as a methyl group, or an aryl group such as a phenyl group, and particularly preferably a methyl group. The ^R1s may be the same group or different groups.

In the above formula (1), a, which indicates the number of repetitions (or degree of polymerization) of the bifunctional diorganosiloxane units (SiR ¹ ₂ O _2/2 ) that constitute the main chain, is an integer of 50 or more, preferably an integer from 50 to 1,500, more preferably an integer from 100 to 1,300, and particularly preferably an integer from 200 to 1,000.
In the present invention, the degree of polymerization (or molecular weight) can be determined, for example, as a polystyrene-equivalent number average degree of polymerization (or number average molecular weight) in gel permeation chromatography (GPC) analysis using toluene, tetrahydrofuran (THF) or the like as a developing solvent.

In order to improve workability and provide sufficient curability by keeping the viscosity of the composition within an appropriate range, the organopolysiloxane of component (A) has a viscosity μ _(A) at 25°C of 100 to 100,000 mPa·s, preferably 300 to 50,000 mPa·s, more preferably 500 to 30,000 mPa·s, and particularly preferably 700 to 20,000 mPa·s. If the viscosity μ _(A) of the organopolysiloxane is less than the lower limit (100 mPa·s), a large amount of component (C) described below is required, which is economically disadvantageous. If the viscosity μ _(A) of the organopolysiloxane exceeds the upper limit (100,000 mPa·s), workability decreases, which is not preferable. Here, the viscosity is a value measured at 25° C. using a B-type rotational viscometer (for example, BL type, BH type, BS type, etc.) (the same applies below).

The organopolysiloxane of component (A) may be used alone or in combination of two or more types.

[Component (B): Hydrolyzable organosilane compound and/or partial hydrolysis condensate thereof]
The component (B) used in the room-temperature-curable organopolysiloxane composition of the present invention is a hydrolyzable organosilane compound and/or a partial hydrolysis condensate thereof, which is represented by the following general formula (2) and has three or four cycloalkenyloxy groups as hydrolyzable groups bonded to silicon atoms in the molecule, and is used as a crosslinking agent (curing agent) and is characterized in that it releases a cyclic ketone compound such as cyclobutanone or cyclopentanone as a leaving group (leaving substance) upon hydrolysis.
In the present invention, the term "partial hydrolysis condensate" refers to an organosiloxane oligomer having three or more, preferably four or more, residual hydrolyzable groups in the molecule, which is produced by partially hydrolyzing and condensing the hydrolyzable organosilane compound.

(In the formula, ^R2 is a monovalent hydrocarbon group having 1 to 10 carbon atoms, n is an integer from 1 to 8, and m is 3 or 4.)

In the above general formula (2), R ² is a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms, and examples of R ² include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, 2-ethylhexyl, nonyl, and decyl groups, alkenyl groups such as vinyl, allyl, propenyl, isopropenyl, butenyl, and hexenyl groups, aryl groups such as phenyl and tolyl groups, and aralkyl groups such as benzyl and phenylethyl groups. Among these, methyl, ethyl, vinyl, and phenyl groups are preferred, and methyl, vinyl, and phenyl groups are particularly preferred.

In the above general formula (2), n is an integer of 1 to 8, preferably an integer of 2 to 6, more preferably an integer of 2 to 4, and even more preferably 2 or 3. When n is 0, no cyclic structure is formed. When n is an integer of 9 or more, the molecular weight of the hydrolyzable organosilane compound becomes large, making purification by distillation difficult and increasing the amount of addition required to ensure storage stability, which is disadvantageous in terms of cost.

As mentioned above, m is 3 or 4. If this number is less than 3 (i.e., if m is 0, 1, or 2), rubber hardening through a crosslinking reaction does not occur, making the compound unsuitable as a crosslinker for room temperature curable organopolysiloxane compositions.

The leaving group (leaving compound) generated by hydrolysis of the hydrolyzable organosilane compound represented by the above general formula (2) is a cyclic ketone compound such as cyclopropanone, cyclobutanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, cyclononanone, cyclodecanone, etc., preferably cyclobutanone and cyclopentanone, more preferably cyclopentanone. There have been no reports of cyclobutanone and cyclopentanone being harmful to human health, such as carcinogenicity or reproductive toxicity, or environmentally, such as being toxic to aquatic organisms. Cyclopentanone is also mass-produced industrially, is easily available, and is highly cost-competitive, making it advantageous for the production of the hydrolyzable organosilane compound of component (B), as described below.

The hydrolyzable organosilane compound of component (B) can be produced, for example, by reacting a chlorosilane compound corresponding to the hydrolyzable organosilane compound represented by general formula (2), which is the product, with a cyclic ketone compound in the presence of a catalyst and a basic substance (e.g., dehydrochlorination reaction). This reaction formula is represented, for example, by the following formula [1].

(In the formula, R ² , n, and m are as defined above.)

Examples of the chlorosilane compound include the following.

Examples of the cyclic ketone compound include the following.

The amount of the cyclic ketone compound to be reacted with the chlorosilane compound is preferably 0.95 to 3.0 moles, more preferably 0.99 to 2.5 moles, and even more preferably 1.0 to 2.0 moles, per mole of chlorine atoms in the chlorosilane compound. If the amount of the cyclic ketone compound added is small, the reaction may not terminate, and if too much is added, purification may take a long time, increasing the production time.

The catalyst used in the reaction includes monovalent or divalent metallic copper compounds, such as, but not limited to, copper chloride, copper bromide, copper iodide, copper sulfate, copper nitrate, copper carbonate, basic copper carbonate, copper formate, copper acetate, and copper butyrate.
The amount of catalyst (metallic copper compound) added is preferably 0.001 to 0.5 mol, more preferably 0.002 to 0.2 mol, and even more preferably 0.003 to 0.1 mol, per mol of the chlorosilane compound. If the amount of catalyst added is too small, the reaction may not be completed, whereas if the amount of catalyst added is too large, it is disadvantageous in terms of cost.

As the basic substance used in the reaction, a basic substance having low nucleophilicity such as trimethylamine, triethylamine, tripropylamine, tributylamine, urea, diazabicycloundecene, diazabicyclononene, etc. can be used. Among these, trimethylamine, triethylamine, and tributylamine are preferred, and triethylamine is particularly preferred.
The amount of the basic substance added is preferably 0.95 to 2.5 mol, more preferably 0.99 to 2.0 mol, and even more preferably 1.0 to 1.5 mol, per mol of chlorine atoms in the chlorosilane compound. If the amount of the basic substance added is small, the reaction may not be completed, whereas if the amount of the basic substance added is too large, it is economically disadvantageous.

[0043] A commonly used solvent may be used in the production of the hydrolyzable organosilane compound of component (B). Examples of the solvent include organic solvents such as aromatic hydrocarbons, such as toluene, xylene, and benzene; aliphatic hydrocarbons, such as pentane, hexane, heptane, nonane, octane, and decane; ethers, such as dimethyl ether, methyl ethyl ether, tetrahydrofuran, and dioxane; halogenated hydrocarbons, such as perchloroethane, perchloroethylene, trichloroethane, chloroform, and carbon tetrachloride; amides, such as dimethylformamide; and esters, such as ethyl acetate, methyl acetate, and butyl acetate.
The amount of the solvent used is not particularly limited, but is usually in the range of 10 to 500 parts by mass, preferably 30 to 400 parts by mass, and more preferably 50 to 300 parts by mass, per 100 parts by mass of the cyclic ketone compound used.

The reaction conditions for the chlorosilane compound and the cyclic ketone compound are usually such that the chlorosilane compound is dropped into the cyclic ketone compound at a temperature of 0 to 120°C, preferably 0 to 100°C, and the reaction is carried out at 50 to 120°C, preferably 60 to 100°C, for 1 to 48 hours, more preferably 3 to 30 hours. If the reaction temperature is too low, the reaction may not be completed, and if the reaction temperature is too high, the product may become significantly colored. In addition, if the reaction time is too short, the reaction may not be completed, and if the reaction time is too long, it is disadvantageous to productivity.
After the reaction is completed, purification can be performed by distilling the target product under reduced pressure, the degree of reduction being preferably 1×10 ⁻⁵ to 3,000 Pa, more preferably 1×10 ⁻⁵ to 2,000 Pa, and the temperature during purification being preferably 100 to 250° C., more preferably 120 to 230° C. If the pressure during reduction (degree of reduction) is too high, distillation may become difficult. If the temperature during purification is too low, purification by distillation may become difficult, and if it is too high, coloration or decomposition of the reaction product may occur.

Specific examples of the hydrolyzable organosilane compound of component (B) include those represented by the following formula: In this case, Me represents a methyl group.

The component (B) may be used alone or in combination of two or more types.
The amount of component (B) is 1 to 40 parts by mass, preferably 3 to 30 parts by mass, and more preferably 5 to 20 parts by mass, per 100 parts by mass of component (A). If the amount of component (B) is less than the lower limit of 1 part by mass, the shelf life of the composition may deteriorate when stored in a sealed container. If the amount of component (B) is more than the upper limit of 40 parts by mass, the curability of the room-temperature-curable organopolysiloxane composition may decrease significantly, and the adhesiveness may also deteriorate.
The hydrolyzable organosilane compound and/or partial hydrolysis condensate thereof of component (B) are clearly distinguished from the silane coupling agent and/or partial hydrolysis condensate thereof of component (F) as an optional component described later in that they do not contain in their molecule a monovalent hydrocarbon group having at least one functional group containing one or more atoms selected from a nitrogen atom, a sulfur atom, and an oxygen atom, or in that the hydrolyzable group bonded to a silicon atom in their molecule is a cycloalkenyloxy group.

[(C) component curing catalyst]
The curing catalyst (C) is used to promote the hydrolysis and condensation reaction of the present composition with moisture in the air, and is generally called a curing catalyst. Any known compounds commonly used in room temperature curable silicone resin compositions can be used, except for organotin compounds which pose environmental safety concerns.

Examples of the curing catalyst of the component (C) include titanate esters or titanium chelate compounds such as tetraisopropoxytitanium, tetra-n-butoxytitanium, tetrakis(2-ethylhexoxy)titanium, isopropoxytitanium bis(ethylacetoacetate), isopropoxybis(acetylacetonate)titanium, and titanium isopropoxyoctylene glycol; phosphazene-containing compounds such as N,N,N',N',N'',N''-hexamethyl-N'''-(trimethylsilylmethyl)-phosphorimidic triamide; Examples of the component (C) include amine compounds or salts thereof, such as dodecylamine and dodecylamine phosphate; quaternary ammonium salts, such as benzyltriethylammonium acetate; dialkylhydroxylamines, such as dimethylhydroxylamine and diethylhydroxylamine; and silanes and siloxanes containing a guanidyl group, such as tetramethylguanidylpropyltrimethoxysilane, tetramethylguanidylpropylmethyldimethoxysilane, and tetramethylguanidylpropyltris(trimethylsiloxy)silane, but the component (C) is not limited to these.
The component (C) may be used alone or in combination of two or more.

The amount of these curing catalysts used may be what is called a catalytic amount, and the blending amount of component (C) is 0.001 to 10 parts by mass, preferably 0.005 to 10 parts by mass, and more preferably 0.01 to 5 parts by mass, per 100 parts by mass of the organopolysiloxane of component (A). If the amount is less than 0.001 part by mass, good rapid curing properties cannot be obtained, resulting in the inconvenience of long curing times. Conversely, if the amount exceeds 10 parts by mass, curing will be too fast, shortening the allowable range of working time after application of the composition and deteriorating the mechanical properties of the resulting rubber.

[Component (D): Bleed Oil]
The (D) component is a bleed oil, and is not particularly limited as long as it is a non-reactive (non-condensation reactive) liquid organic compound that does not undergo a condensation reaction with the (A) component diorganopolysiloxane and the (B) component hydrolyzable organosilane compound and/or its partial hydrolysis condensate, and is also incompatible (bleeding) in the crosslinked cured matrix. Among these, polyether, polyacrylate, polymethacrylate, polyisobutylene, and organopolysiloxane are preferred, polyether and organopolysiloxane are particularly preferred, and organopolysiloxane is even more preferred.

The organopolysiloxane (so-called silicone oil) that can be used as the bleed oil is a non-functional silicone oil whose main chain is a siloxane skeleton (particularly a linear diorganopolysiloxane structure consisting of repeated difunctional diorganosiloxane units) and whose molecular chain ends are blocked with triorganosiloxy groups, and there are no particular restrictions on the silicone oil as long as it bleeds from within the silicone rubber cured product (crosslinked organosiloxane matrix) obtained by curing the room temperature curable organopolysiloxane composition of the present invention to the surface of the cured product.

For example, there is a dimethyl silicone oil in which all of the organo groups (unsubstituted or substituted monovalent hydrocarbon groups) bonded to silicon atoms in the diorganosiloxane units constituting the siloxane skeleton of the main chain are methyl groups, a methylphenyl silicone oil in which some of the methyl groups of this dimethyl silicone oil are substituted with phenyl groups, an amino-modified silicone oil in which a monoamine, diamine or amino-polyether group is substituted, an epoxy-, alicyclic epoxy, epoxy-polyether or epoxy-aralkyl group is substituted, a carbinol-modified silicone oil in which a carbinol group is substituted, a mercapto-modified silicone oil in which a mercapto group is substituted, a carboxyl-modified silicone oil in which a carboxyl group is substituted, a methacryl-modified silicone oil in which a methacryl group is substituted, a polyether- or polyether-long-chain (C _6-18 ) alkyl-aralkyl group is substituted, and a long-chain (C _6-18 ) alkyl or a long-chain (C _{6-18 )} alkyl-aralkyl group is substituted. ) alkyl-modified silicone oil, higher fatty acid-modified silicone oil substituted with a higher fatty acid ester group, and fluoroalkyl-modified silicone oil substituted with a fluoroalkyl group, among which methylphenyl silicone oil, polyether-modified silicone oil, long-chain ( _C6-18 ) alkyl-modified silicone oil, etc. are preferred.

The viscosity μ _(D ) of component (D) at 25° C. is preferably 20 to 30,000 mPa·s, more preferably 30 to 5,000 mPa·s, and even more preferably 50 to 1,000 mPa·s. If the viscosity μ _(D) at 25° C. is less than 20 mPa·s, the soil resistance may be poor, and if it is more than 30,000 mPa·s, the viscosity of the composition may be too high, making it difficult to use, and the soil resistance may also decrease.

Furthermore, the bleed oil of component (D) preferably has a ratio [μ _(D) /μ(A)] of the viscosity μ _(D) of component (D) at 25°C to the viscosity μ _(A ) of component _{(A) at} 25°C of the component (D) in terms of bleeding properties, soil resistance, and the like, of 0.05 to 1, more preferably 0.06 to 0.8, even more preferably 0.07 to 0.5, and particularly preferably 0.08 to 0.3.

The component (D) may use one type alone, or two or more types in combination.
The blending amount of component (D) is 0.01 to 100 parts by mass, and preferably 10 to 100 parts by mass, per 100 parts by mass of component (A). If the blending amount of component (D) is within the above range, for example, when used as an antifouling paint, an (antifouling) coating film with excellent antifouling properties and coating film strength tends to be obtained, whereas if the blending amount is less than the above range, the antifouling properties may decrease, and if the blending amount is more than the above range, the coating film strength may decrease.

The room temperature curable organopolysiloxane composition of the present invention may contain the following components as necessary.
[Component (E): Filler]
The component (E) is a filler (inorganic filler and/or organic resin filler), which is an optional component that can be blended as necessary, and is used to give sufficient mechanical strength to the cured product formed from this composition. Known fillers can be used as this filler, and examples of fillers that can be used include fine powder silica (pulverized silica), spherical silica, and fumed silica (fumed silica), wet silica such as precipitated silica and sol-gel silica, reinforcing silica fillers such as silica whose surface has been hydrophobized with an organic silicon compound, glass beads, glass balloons, transparent resin beads, silica aerogel, diatomaceous earth, metal oxides such as iron oxide, zinc oxide, titanium oxide, and fumed metal oxides, quartz powder (crystalline silica fine powder), reinforcing agents such as carbon black, talc, zeolite, and bentonite, asbestos, glass fiber, carbon fiber, metal carbonates such as calcium carbonate, magnesium carbonate, and zinc carbonate, asbestos, glass wool, fine mica, fused silica powder, and synthetic resin powders such as polystyrene, polyvinyl chloride, and polypropylene. Among these fillers, inorganic fillers such as silica, calcium carbonate, and zeolite are preferred, and fumed silica is particularly preferred.

The specific surface area of a silica-based filler such as fumed silica, as measured by the BET method, is usually preferably 30 to 400 ^m2 /g, more preferably 50 to 300 ^m2 /g. If the specific surface area of the silica-based filler is less than 30 ^m2 /g, the shape retention of the composition may decrease, whereas if the specific surface area exceeds 400 ^m2 /g, the viscosity of the composition may increase significantly, decreasing workability.

The component (E) may use one type alone, or two or more types in combination.
The amount of component (E) blended is preferably 0 to 100 parts by mass, and when blended, 1 part by mass or more, particularly 3 to 60 parts by mass, per 100 parts by mass of component (A). If more than 100 parts by mass is used, not only does the viscosity of the composition increase and workability deteriorate, but the rubber strength after curing decreases, making it difficult to obtain rubber elasticity.

[Component (F): Adhesion promoter]
The component (F) is an adhesion promoter, which is an optional component that can be blended as necessary, and is used to provide sufficient adhesion to the cured product formed from this composition. As the adhesion promoter (for example, a silane coupling agent such as a carbon-functional group-containing hydrolyzable silane (so-called CF silane) having two or more hydrolyzable groups such as an alkenyl group or a functional group having at least one heteroatom selected from oxygen atoms, nitrogen atoms, and sulfur atoms (excluding guanidyl groups) and an unsubstituted or substituted alkoxy group in the molecule), a known one other than the components (B) and (C) is preferably used, and examples thereof include vinyl silane coupling agents, (meth)acrylic silane coupling agents, epoxy silane coupling agents, amino silane coupling agents, mercapto silane coupling agents, isocyanate coupling agents, etc. Specific examples of the coupling agent include vinyl tris(β-methoxyethoxy)silane, γ-methacryloxypropyl trimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, γ-glycidoxypropyl trimethoxysilane, γ-glycidoxypropyl methyl diethoxysilane, γ-aminopropyl triethoxysilane, 3-2-(aminoethylamino)propyl trimethoxysilane, γ-mercaptopropyl trimethoxysilane, isocyanate propyl triethoxysilane, isocyanate propyl trimethoxysilane, etc. Among these, aminosilane coupling agents such as γ-aminopropyl triethoxysilane and 3-2-(aminoethylamino)propyl trimethoxysilane, epoxy silane coupling agents such as γ-glycidoxypropyl trimethoxysilane and β-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, and isocyanate silane coupling agents such as isocyanate propyl triethoxysilane are particularly preferred.

The component (F) may use one type alone, or two or more types in combination.
The amount of component (F) is preferably 0 to 20 parts by mass, and when used, 0.1 part by mass or more, particularly 0.1 to 10 parts by mass, per 100 parts by mass of component (A). When adhesion can be achieved without the use of an adhesion promoter depending on the filler and adherend, this need not be used.

[Other ingredients]
Furthermore, the room temperature curable organopolysiloxane composition of the present invention may contain additives other than the above components, provided the addition does not impair the object of the present invention.
Examples of such additives include isoparaffin as a wetter or thixotropy improver, three-dimensional network polysiloxane (so-called silicone resin) consisting of trimethylsiloxy units [( _CH3 ) _{3SiO1 /2} units] and _SiO2 units as a crosslink density improver, etc. Furthermore, if necessary, colorants such as pigments, dyes, and fluorescent whitening agents, surface modifiers other than component (D) such as antifungal agents, antibacterial agents, and organic liquids incompatible with silicone, and solvents such as toluene, xylene, solvent volatile oils, cyclohexane, methylcyclohexane, and low-boiling point isoparaffins may be added.

The room temperature curable organopolysiloxane composition of the present invention can further contain known additives such as antioxidants, antioxidants, antistatic agents, antimony oxide, and flame retardants such as chlorinated paraffin.

[Preparation of Room Temperature Curable Organopolysiloxane Composition]
The room temperature curable organopolysiloxane composition of the present invention can be produced, for example, by mixing the above-mentioned components under normal pressure or reduced pressure, preferably under a reduced pressure of -0.09 to -0.01 MPa, and mixing without heating, preferably at 60° C. or less, usually for about 15 minutes to 3 hours, preferably for about 30 minutes to 2 hours. When the composition contains a filler of component (E), the composition is produced by previously mixing components (A) and (E) under reduced pressure, preferably under a reduced pressure of -0.09 to -0.01 MPa, with heating, preferably at 80 to 160° C., for about 30 minutes to 3 hours, and then mixing the remaining components under normal pressure or reduced pressure, preferably under a reduced pressure of -0.09 to -0.01 MPa, with heating, preferably at 60° C. or less, usually for about 30 minutes to 3 hours, thereby obtaining a cured coating film with superior surface smoothness and viscosity stability over time.

When the room temperature curable organopolysiloxane composition of the present invention is used as a coating material or paint, particularly as an antifouling paint, it has excellent stability during preparation, storage, and preservation, and also has good fast curing properties. The resulting coating film has a good balance of rubber properties such as hardness, tensile strength, and elongation, and also has excellent antifouling properties, making it particularly suitable for use as an antifouling coating film.

The viscosity of the room temperature curable organopolysiloxane composition of the present invention at 25°C is preferably 500 to 200,000 mPa·s, and particularly preferably 1,000 to 150,000 mPa·s, which is a viscosity that is particularly suitable for coating.

The above-described room-temperature curable organopolysiloxane composition of the present invention is coated (applied) onto the surface of various substrates and cured to form a coating layer, thereby obtaining a coated substrate. In this case, the method for coating the composition is not particularly limited, and can be appropriately selected from known methods such as spray coating, spin coating, dip coating, roller coating, brush coating, bar coating, and flow coating. The room-temperature curable organopolysiloxane composition of the present invention can also be further diluted with the above-mentioned solvents to suit various coating methods when coated (applied).

The room temperature curable organopolysiloxane composition of the present invention is highly suitable for applications such as coating materials requiring water resistance, such as ship bottom paints, paints for seawater inlet pipes at power plants, and fishing net paints; moisture-proof coating materials for LCDs and PDPs requiring moisture resistance; adhesive seals between electric wires and resin coatings; adhesive seals between resin cases or resin connectors and electric wires; and adhesive seals for vacuum or pressurized chambers. In particular, the composition can be used as a substrate to coat underwater structures such as ships, port facilities, buoys, pipelines, bridges, offshore bases, offshore oil field drilling equipment, power plant water conduit pipes, aquaculture nets, and fixed nets. The cured coating film of the composition is non-toxic and poses no environmental problems, and can prevent the attachment and growth of aquatic organisms over a long period of time, exhibiting excellent antifouling properties.

The amount of the room-temperature-curable organopolysiloxane composition of the present invention to be coated on a substrate such as an underwater structure or a ship is not particularly limited, but it is preferably an amount that results in a film thickness after curing of 10 to 1,000 μm, and particularly 50 to 500 μm. The room-temperature-curable organopolysiloxane composition of the present invention may be applied and cured at room temperature (normal temperature).
The film thickness can be measured by, for example, a spectroscopic reflectance measurement method, an X-ray reflectance measurement method, a spectroscopic ellipsometry measurement method, an X-ray fluorescence measurement method, or the like.

The present invention will be specifically explained below with synthesis examples, working examples, and comparative examples, but the present invention is not limited to these examples. In the following specific examples, "parts" means "parts by mass," the viscosity is the value measured with a B-type rotational viscometer at 25°C, and the film thickness is the value measured by a spectroscopic ellipsometry measurement method using a spectroscopic ellipsometer.

The method for synthesizing the hydrolyzable organosilane compound of component (B) is as follows:

[Synthesis Example 1] Synthesis of hydrolyzable organosilane compound 1 834g (9.9 mol) of cyclopentanone, 825g (8.2 mol) of triethylamine, 5g (0.05 mol) of copper (I) chloride, and 1,500mL of hexane were charged into a 5,000mL four-necked separable flask equipped with a mechanical stirrer, a thermometer, a reflux tube, and a dropping funnel, and 400g (2.47 mol) of vinyltrichlorosilane was dropped over about 2 hours at a temperature of 40 to 60°C. After stirring at 80°C for 12 hours, the generated triethylamine hydrochloride was removed by filtration, and hexane was distilled from the filtrate at 100°C and normal pressure, followed by distillation at 180°C and 300 Pa to obtain hydrolyzable organosilane compound 1 (yield 532g, yield 69%). This reaction formula is represented by the following formula [2].

[Synthesis Example 2] Synthesis of hydrolyzable organosilane compound 2 834g (9.9 mol) of cyclopentanone, 825g (8.2 mol) of triethylamine, 5g (0.05 mol) of copper (I) chloride, and 1,500mL of hexane were charged into a 5,000mL four-necked separable flask equipped with a mechanical stirrer, a thermometer, a reflux tube, and a dropping funnel, and 368g (2.47 mol) of methyltrichlorosilane was dropped over about 2 hours at a temperature of 40 to 60°C. After stirring for 12 hours at 80°C, the generated triethylamine hydrochloride was removed by filtration, and hexane was distilled from the filtrate at 100°C and normal pressure, followed by distillation at 170°C and 300 Pa to obtain hydrolyzable organosilane compound 2 (yield 519g, yield 71%). This reaction formula is represented by the following formula [3].

Examples of room temperature curable organopolysiloxane compositions are described below.
[Example 1]
90 parts of linear dimethylpolysiloxane (component (A): dimethylpolysiloxane in which R 1 =methyl and a =approximately 310 in the above general formula (1)) having a viscosity μ _(A) of ^1,500 mPa·s and both molecular chain terminals are blocked with silanol groups (hydroxyl groups bonded to silicon atoms) were uniformly mixed with 10 parts of untreated fumed silica having a BET specific surface area of 200 m ² /g, and mixed at 150° C. for 2 hours under a reduced pressure of −0.08 MPa. After 2 hours, the obtained base was passed once through a triple roll, after which 10 parts of hydrolyzable organosilane compound 1, 0.4 parts of γ-aminopropyltriethoxysilane, and 0.5 parts of tetramethylguanidylpropyltrimethoxysilane were added, and mixed for 30 minutes at 20 to 40° C. under a reduced pressure of −0.06 to −0.04 MPa until the mixture became uniform. Further, 30 parts of an α,ω-trimethylsiloxy-dimethyldiphenylpolysiloxane (component (D): dimethylsiloxane-diphenylsiloxane copolymer capped with trimethylsiloxy at both ends) having a viscosity μ _(D) of 300 mPa·s was added and mixed for 30 minutes at 20 to 40° C. under a reduced pressure of −0.06 to −0.04 MPa until the mixture was homogenous, thereby preparing Composition 1 having a viscosity of 15,300 mPa·s.
In composition 1, the ratio [μ _(D) /μ _(A) ] of the viscosity μ _(A) of component (A) at 25° C. to the viscosity μ _(D) of component (D) at 25° C. was 0.20.

[Example 2]
Composition 2 having a viscosity of 15,600 mPa·s was prepared in the same manner as in Example 1, except that 0.4 parts of 3-2-(aminoethylamino)propyltrimethoxysilane was used instead of the γ-aminopropyltriethoxysilane in Example 1.

[Example 3]
90 parts of a linear dimethylpolysiloxane (component (A): dimethylpolysiloxane in which R 1 =methyl and a =approximately 310 in the above general formula (1)) having a viscosity μ _(A) of ^1,500 mPa·s and both molecular chain terminals are blocked with silanol groups (hydroxyl groups bonded to silicon atoms) were uniformly mixed with 10 parts of untreated fumed silica having a BET specific surface area of 200 m ² /g, and mixed at 150° C. for 2 hours under a reduced pressure of −0.08 MPa. After 2 hours, the resulting base was passed once through a triple roll mill, after which 10 parts of hydrolyzable organosilane compound 2, 0.4 parts of γ-aminopropyltriethoxysilane, and 0.5 parts of tetramethylguanidylpropyltrimethoxysilane were added, and mixed for 30 minutes at 20 to 40° C. under a reduced pressure of −0.06 to −0.04 MPa until the mixture became uniform. Further, 30 parts of α,ω-trimethylsiloxy-dimethyldiphenylpolysiloxane (component (D)) having a viscosity μ _(D) of 300 mPa·s was added and mixed for 30 minutes at 20 to 40° C. under a reduced pressure of −0.06 to −0.04 MPa until homogenous, preparing composition 3 having a viscosity of 16,100 mPa·s.
In composition 3, the ratio [μ _(D) /μ(A)] of the viscosity μ _(D) of component (D) at 25° C. to the viscosity μ( _A ) of component _(A ) at 25° C. was 0.20.

[Example 4]
Composition 4 having a viscosity of 15,900 mPa·s was prepared in the same manner as in Example 3, except that 0.4 parts of 3-2-(aminoethylamino)propyltrimethoxysilane was used instead of the γ-aminopropyltriethoxysilane in Example 3.

[Example 5]
90 parts of linear dimethylpolysiloxane (component (A): dimethylpolysiloxane in which R 1 =methyl and a =approximately 270 in the above general formula (1)) having a viscosity μ _(A) of ⁷⁰⁰ mPa·s and both molecular chain terminals are blocked with silanol groups (hydroxyl groups bonded to silicon atoms) were uniformly mixed with 10 parts of untreated fumed silica having a BET specific surface area of 200 m ² /g, and mixed at 150° C. for 2 hours under a reduced pressure of −0.08 MPa. After 2 hours, the resulting base was passed once through a triple roll mill, after which 10 parts of hydrolyzable organosilane compound 1, 0.4 parts of γ-aminopropyltriethoxysilane, and 0.5 parts of tetramethylguanidylpropyltrimethoxysilane were added, and mixed for 30 minutes at 20 to 40° C. under a reduced pressure of −0.06 to −0.04 MPa until the mixture became uniform. Further, 30 parts of a polyether-modified polysiloxane (component (D): X-22-2516: manufactured by Shin-Etsu Chemical Co., Ltd.) having a viscosity μ _(D) of 60 mPa·s was added and mixed for 30 minutes at 20 to 40° C. under a reduced pressure of −0.06 to −0.04 MPa until the mixture became uniform, thereby preparing Composition 5 having a viscosity of 9,200 mPa·s.
In composition 5, the ratio [μ _(D) /μ _(A) ] of the viscosity μ _{( D) of component (D) at 25° C. to the viscosity μ(A} ) of component (A) at 25° C. was 0.086.

[Example 6]
Composition 6 having a viscosity of 9,600 mPa·s was prepared in the same manner as in Example 5, except that 0.4 parts of 3-2-(aminoethylamino)propyltrimethoxysilane was used instead of the γ-aminopropyltriethoxysilane in Example 5.

[Comparative Example 1]
Composition 7 having a viscosity of 17,900 mPa·s was prepared in the same manner as in Example 1, except that 30 parts of the α,ω-trimethylsiloxy-dimethyldiphenylpolysiloxane having a viscosity of 300 mPa·s was not blended in.

[Comparative Example 2]
Composition 8 having a viscosity of 14,500 mPa·s was prepared in the same manner as in Example 1, except that 10 parts of methyltrimethoxysilane was used instead of the hydrolyzable organosilane compound 1 in Example 1.

[Comparative Example 3]
90 parts of dimethylpolysiloxane, both ends of which are blocked with trimethoxysilyl groups and have a viscosity of 900 mPa·s at 25° C., and 10 parts of non-surface-treated fumed silica with a BET specific surface area of 200 ^m2 /g were mixed uniformly and mixed under a reduced pressure of -0.08 MPa at 150° C. for 2 hours. After 2 hours, the obtained base was passed through a triple roll once, and then 4.5 parts of methyltrimethoxysilane, 1.5 parts of a hydrolysis condensate of methyltrimethoxysilane (average 3-4 monomers), 0.4 parts of γ-aminopropyltriethoxysilane, and 2 parts of isopropoxytitaniumbis(ethylacetoacetate) were added, and mixed for 30 minutes at 20-40° C. under a reduced pressure of -0.06 to -0.04 MPa until the mixture became uniform. Further, 30 parts of α,ω-trimethylsiloxy-dimethyldiphenylpolysiloxane having a viscosity of 300 mPa·s was added and mixed for 30 minutes at 20 to 40° C. under a reduced pressure of −0.06 to −0.04 MPa until homogenous, to prepare Composition 9 having a viscosity of 10,600 mPa·s.

<Performance test>
Using the compositions obtained above, various performance tests were carried out according to the test methods shown below.

[Test Method]
(A) Confirmation of Curability According to the method specified in JIS K 6249, the tack-free time at a coating thickness of 200 μm was measured.

(B) Physical Properties after Curing Compositions 1 to 7 and 9, excluding composition 8 which was not cured, were molded into sheets having a thickness of 2 mm, which were cured at 23° C./50% RH for 7 days, and the rubber physical properties (hardness, elongation, tensile strength) were measured in accordance with JIS K 6249.

(C) Coating workability Each of compositions 1 to 7 and 9, excluding composition 8 that did not harden, was uniformly mixed with 10 g of xylene to prepare a test coating sample. A mild steel plate of 100 mm x 100 mm x 1 mm (thickness) was attached to the center of a tin plate of 1,000 mm x 1,000 mm x 1 mm (thickness), and airless spray coating was performed with the tin plate standing vertically. The presence or absence of clogging of the spraying tool (sprayability) was confirmed (visually) according to the following criteria, and the critical film thickness at which the film sagging occurred was measured after the coating film dried.
[Sprayability]
Good: No clogging of the equipment when spraying. Bad: Clogging of the equipment when spraying.

(D) Antifouling properties: 90 g of each of compositions 1 to 7 and 9, except for composition 8 that was not cured, was mixed with 10 g of xylene on a plate that had been previously coated with an epoxy-based anticorrosive paint (film thickness 200 μm) so that the cured film thickness was 200 μm. A test paint sample was prepared, and then spray-painted to prepare a test coated plate. The test coated plate thus prepared was cured for 7 days under the conditions of 23°C/50% RH. The test coated plate after curing was subjected to a suspension test at a depth of 1.5 m off the coast of Kanagawa Prefecture for 12 months. The adhesion state of shellfish such as barnacles and seaweed was observed after 3, 6, and 12 months.

(E) Paint Stability After preparing the above test paint samples, the paint condition (stability) and painting workability after 6 months at 23°C in a sealed state were tested. The paint condition (stability) was evaluated by stirring the paint after opening the can and inspecting it with a grain gauge (particle gauge) and using the following criteria. Painting workability was measured in the same manner as above.
[Paint condition]
Good: No grains (uneven solid parts) of 50 μm or more are visually confirmed on the paint surface of the grain gauge. Bad: Grains (uneven solid parts) of 50 μm or more are visually confirmed on the paint surface of the grain gauge.

(F) Adhesion A test plate was pre-coated with an epoxy-based anticorrosive paint (film thickness 200 μm), and 90 g of each of compositions 1 to 7 and 9, excluding composition 8 that was not cured, was uniformly mixed with 10 g of xylene so that the cured film thickness was 200 μm. The test plate was then spray-coated. After a certain time (30 minutes, 60 minutes, 90 minutes) from coating, a cutter was used to make a cut that reached the anticorrosive paint on the coating surface, and the coating adhesion was evaluated by rubbing the cut with a finger in a perpendicular direction. The case where the coating did not peel off was evaluated as ○, and the case where the coating peeled off was evaluated as ×.
The test results are shown in Tables 1 and 2.

Although the present invention has been described using the embodiments shown above, the present invention is not limited to the above embodiments and can be modified within the scope of what a person skilled in the art can conceive, and any embodiment is within the scope of the present invention as long as it achieves the effects of the present invention.

The room temperature curable organopolysiloxane composition of the present invention is an environmentally friendly composition that does not contain organotin compounds and does not generate methyl ethyl ketoxime (MEKO) during curing. In addition, it has excellent fast curing properties, and the resulting coating film has coating film strength, coating film hardness, rubber properties, water resistance, and moisture resistance, making it highly suitable for applications such as coating materials that require water resistance, such as ship bottom paints, paints for seawater inlet pipes to power plants, and paints for fishing nets, moisture-proof coating materials that require moisture resistance, such as LCDs and PDPs, adhesive seals between electric wires and resin coatings, adhesive seals between resin cases or resin connectors and electric wires, and adhesive seals for reduced pressure or pressurized chambers. In particular, it can be used as a ship bottom paint, paint for seawater inlet pipes to power plants, paint for fishing nets, etc. to prevent the attachment and growth of aquatic organisms on the surfaces of these materials.

Claims (9)

1. A room-temperature curable organopolysiloxane composition comprising the following components (A) to (D):
   (A) 100 parts by mass of an organopolysiloxane having a viscosity μ _(A) at 25° C. of 100 to 100,000 mPa·s, which is represented by the following general formula (1):
   HO-(SiR ¹ ₂ O) _a -H (1)
   (In the formula, R ¹ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and each R ¹ may be the same or different. a is an integer of 50 or more.)
   (B) a hydrolyzable organosilane compound represented by the following general formula (2) and/or a partial hydrolysis condensate thereof: 1 to 40 parts by mass,
   

   

   (In the formula, ^R2 is a monovalent hydrocarbon group having 1 to 10 carbon atoms, n is an integer from 1 to 8, and m is 3 or 4.)
   (C) a curing catalyst (excluding organotin compounds): 0.001 to 10 parts by mass, and (D) a bleed oil: 0.01 to 100 parts by mass.
2. The room-temperature curable organopolysiloxane composition according to claim 1, wherein the hydrolyzable organosilane compound and/or its partial hydrolysis condensate of component (B) releases a cyclic ketone compound by hydrolysis.
3. The room temperature curable organopolysiloxane composition according to claim 2, wherein the cyclic ketone compound that is eliminated is cyclobutanone or cyclopentanone.
4. 2. The room-temperature-curable organopolysiloxane composition according to claim 1, wherein component (D) has a viscosity μ _(D) at 25° C. of 20 to 30,000 mPa·s.
5. 2. The room-temperature-curable organopolysiloxane composition according to claim 1, wherein the ratio [μ _(D) /μ _(A) ] of the viscosity μ( _{A )} of component (A) at 25°C to the viscosity μ(D) of component (D) at 25°C is 0.05 to 1.
6. Further, for every 100 parts by mass of the component (A),
   2. The room-temperature-curable organopolysiloxane composition according to claim 1, further comprising one or more selected from the group consisting of (E) a filler: 1 to 100 parts by mass, and (F) an adhesion promoter: 0.1 to 20 parts by mass.
7. The room temperature curable organopolysiloxane composition according to claim 1, which is used for coating underwater structures or ships.
8. A substrate coated with a cured product of the room temperature curable organopolysiloxane composition according to any one of claims 1 to 7.
9. The substrate according to claim 8, which is an underwater structure or a ship.