DESCRIPTION ANTIFOULING COATING COMPOSITION APPLICABLE IN FRESHWATER ENVIRONMENT, COATING FILM THEREOF AND ANTIFOULING METHOD
Technical Field [0001]
The present invention relates to an antifouling coating composition applicable in freshwater environment, a coating film thereof and an antifouling method. More particularly, the present invention relates to an antifouling coating composition applicable in freshwater environment which is applicable to coating materials for ships constructed in ocean (seawater) and also in large rivers (freshwater) in such countries as China and Vietnam; an antifouling coating film applicable in freshwater environment; a substrate with the antifouling coating film applicable in freshwater environment; a method for forming on the surface of the substrate the antifouling coating film applicable in freshwater environment; and a method for preventing the substrate from fouling.
Background of the Invention [0002]
With recent economic development in countries like China,
industries have been increasingly prosperous not just in harbor areas facing Pacific Ocean and also in areas of large rivers like Yellow River and Yangtze River, leading to active constructions of large ships for open sea. [0003]
Yet, with the application of a known antifouling coating material exclusively designed for ocean ships typified by a cuprous oxide-containing hydrolyzable antifouling coating material into a ship primarily used in freshwater environment like large rivers, there arises a problem that the coating film has insufficient resistance against plain water and therefore the ship with.such a coating film constructed in a shipyard of river water regions has a significantly softened coating film and sometimes a coating film having defects such as blistering, cracking and peeling. [0004]
As an antifouling coating composition to solve the problems, JP-A-2006-70104 (Patent Document 1) describes an antifouling coating composition applicable in freshwater environment comprising a specific metal salt copolymer (A) and a cuprous oxide (B) which is surface-treated with a higher fatty acid. [0005]
On the other hand, JP-A-2005-15531 (Patent Document 2) and JP-A-2006-152205 (Patent Document 3) disclose an antifouling
coating material comprising a hydrolyzable resin and an alicyclic hydrocarbon resin having a functional group such as an ester group; and it is described therein that the hydrolyzable resin is an acrylic resin in a side chain having a group represented by: [0006]
(Formula Removed)
[0007]
(In the formula, X is a group represented by: [0008]
(Formula Removed)
[0009]
k is 0 or 1, Y is a hydrocarbon, M is a divalent metal and A is an organic acid residue of a monobasic acid); or that the hydrolyzable resin is an acrylic resin in a side chain having a group represented by:
[0010]
(Formula Removed)
[0011]
(In the formula, R1, R2 and R3 are identical or different
and represent hydrocarbon residues having 1 to 20 carbon atoms.) [0012]
These antifouling coating materials are provided to prevent underwater structures (such as ships and fishing nets) employed in seawater from fouling but are not expected to prevent underwater structures employed in freshwater environment from fouling.
Citation List Patent Documents [0013]
Patent Document 1: JP-A-2006-70104
Patent Document 2: JP-A-2005-15531
Patent Document 3: JP-A-2006-152205
Summary of the Invention
Problems to be Solved by the Invention
[0014]
The antifouling coating composition applicable in freshwater environment described in Patent Document 1 needs further improvement. Moreover, coating films formed from the antifouling coating materials described in Patent Documents 2 and 3, when used in freshwater environment, are found to be basically short of water resistance. [0015]
In view of the problems with these conventional techniques, the present invention has been made. It is an obj ect of the present invention to provide an antifouling coating composition capable of forming an antifouling coating film which shows superior strength even after immersed in freshwater and maintains adhesion in freshwater even where re-coating is performed at an interval of time (adhesion between the antifouling coating materials), which does not have an excessive polishing degree in seawater after immersed in freshwater and which retains practical polishing degree in seawater and has excellent antifouling properties. It is another object of the present invention to provide an antifouling coating film to exhibit such effects and a substrate with such an antifouling coating film.
[0016]
It is still another object of the present invention to provide a method for forming the antifouling coating film to exhibit the above effects.
[0017]
It is still another object of the present invention to provide a method for preventing the substrate from fouling to exhibit the above effects.
Means for Solving the Problems [0018]
The present inventor made diligent studies and completed the present invention by finding out that the use of as essential components, a specific metal salt bond-containing polymer and an alicyclic hydrocarbon resin can solve the above problem. [0019]
The antifouling coating composition applicable in freshwater environment of the present invention comprises:
a metal salt bond-containing polymer (A) comprising a constituent unit (al) derived from a (meth) acrylic acid metal salt monomer (al) represented by the formula (I):
(Formula Removed)
wherein, M is magnesium, zinc or copper; and R1s each independently represent a hydrogen atom or a methyl group, and
an alicyclic hydrocarbon resin (B) having at least one group selected from an ester group, a hydroxyl group and a carboxyl group. [0020]
The metal salt bond-containing polymer (A) is preferably a copolymer further comprising a constituent unit (a2) derived from an unsaturated monomer (a2) copolymerizable with the monomer (al). Usually, the content of the constituent unit (al) is 5 to 100% by weight and the content of the constituent unit (a2) is 0 to 95% by weight. [0021]
The antifouling coating composition applicable in freshwater environment preferably contains 0.1 to 100 parts by weight of the alicyclic hydrocarbon resin (B) based on 100 parts by weight of the metal salt bond-containing polymer (A). [0022]
The antifouling coating composition applicable in freshwater environment may further comprise an extender pigment. The extender pigment is preferably zinc oxide. [0023]
The antifouling coating composition applicable in freshwater environment may further comprise an inorganic antifouling agent. The inorganic antifouling agent is preferably cuprous oxide. [0024]
The antifouling coating composition applicable in freshwater environment may further comprise an organic antifouling agent. The organic antifouling agent is preferably at least one compound selected from the group consisting of a pyrithione compound, a tri-organic boron, an amine complex thereof and 4,5-dichloro-2-n-octyl-4-isothiazoline-3-one. [0025]
The antifouling coating composition applicable in freshwater environment may further comprise a solid resin, (i.e. a resin which is other than the metal salt bond-containing polymer
(A) and the alicyclic hydrocarbon resin (B) and which is solid at ordinary temperature). As the other solid resin, it is preferable to employ a rosin and/or a terpene phenol resin. [0026]
The antifouling coating film applicable in freshwater environment according to the present invention is formed from the antifouling coating composition applicable in freshwater environment. [0027]
The substrate with the antifouling coating film applicable in freshwater environment according to the present invention has its surface coated with the antifouling coating film applicable in freshwater environment. [0028]
The substrate is preferably an underwater structure or an outer board of a ship. [0029]
The method for forming the antifouling coating film applicable in freshwater environment on the surface of the substrate according to the present invention comprises the steps of coating or impregnating the surface of the substrate with the antifouling coating composition applicable in freshwater environment, curing the composition and thereby forming a coating film.
[0030]
The method for preventing the substrate from fouling according to the present invention comprises the steps of coating or impregnating the surface of the substrate with the antifouling coating composition applicable in freshwater environment, curing the composition and thereby forming an antifouling coating film.
Effects of the Invention [0031]
According to the present invention, there is provided an antifouling coating composition capable of forming an antifouling coating film which shows superior strength even after immersed in freshwater and maintains adhesion in freshwater where there is an interval of time between coatings (adhesion to the substrate) , which does not have an excessive polishing degree in seawater after immersed in freshwater and which retains suitable polishing degree in seawater and has excellent antifouling properties. According to the present invention, there are also provided an antifouling coating film to exhibit such effects and a substrate with such an antifouling coating film. [0032]
According to the present invention, there is also provided a method for forming on the surface of the substrate the antifouling coating film applicable in freshwater environment to
exhibit the above effects. [0033]
According to the present invention, there is also provided a method for preventing the substrate from fouling to exhibit the above effects.
Embodiment for Carrying out the Invention [0034]
Hereinafter, detailed descriptions are provided regarding the present invention: an antifouling coating composition applicable in freshwater environment, an antifouling coating film applicable in freshwater environment, a substrate with the antifouling coating film applicable in freshwater environment, a method for forming on the surface of the substrate the antifouling coating film applicable in freshwater environment and a method for preventing the substrate from fouling. [0035]
[Antifouling Coating Composition Applicable In Freshwater Environment]
The antifouling coating composition applicable in freshwater environment according to the present invention (hereinafter, referred to also simply as an "antifouling coating composition") comprises the following metal salt bond-containing polymer (A) and the alicyclic hydrocarbon resin (B).
[0036]

The metal salt bond-containing polymer (a hydrolyzable and metal-crosslinked polymer)(A)(hereinafter, referred to also simply as "polymer (A)") comprises a constituent unit (al) derived from a (meth)acrylic acid metal salt monomer (al) (referred to also simply as "monomer (al)") represented by the formula (I):
(Formula Removed)
wherein, M is magnesium, zinc or copper; and R1s each independently represent a hydrogen atom or a methyl group.
[0037]
It is considered that the constituent unit (al) is mainly a structure represented by:
[0038]
(Formula Removed)
[0039]
[0040]
In the production of the metal salt bond-containing polymer
(A), the (meth)acrylic acid metal salt monomer (al) is not necessarily used as a monomer. As long as the constituent unit derived from the monomer (al) (the constituent unit (al)) is
present in the resultant polymer, a production method of the
polymer (A) is not particularly limited.
[0041]
Examples of the (meth) acrylic acid metal salt monomer (al) , include a magnesium (meth) acrylate such as (CH2=CHCOO) 2Mg, (CH2=C(CH3)COO)2Mg and (CH2=CHCOO) (CH2=C (CH3) COO) Mg; a zinc (meth) acrylate such as (CH2=CHCOO) 2Zn, (CH2=C (CH3) COO) 2Zn and (CH2=CHCOO) (CH2=C (CH3) COO) Zn; and a copper (meth) acrylate such as (CH2=CHCOO)2Cu, (CH2=C(CH3)COO)2Cu and (CH2=CHCOO) (CH2=C (CH3) COO) Cu. [0042]
A single or two or more kinds of the constituent units (al) may be contained. For example, as the constituent unit (al), a constituent unit derived from the zinc (meth)acrylate and a constituent unit derived from the copper (meth)acrylic may be contained. [0043]
It is preferable in terms of controlling the resin elution rate that the metal salt bond-containing polymer (A) comprising the constituent unit (al) derived from the monomer (al) further comprises a constituent unit (a2) derived from an "unsaturated monomer (a2)" copolymerizable with the monomer (al). [0044]
Examples of the "unsaturated monomer (a2)" include a
monobasic acid metal(meth)acrylate (a21) and an unsaturated monomer (a22), as described later. [0045]
Thus, in addition to the constituent unit (al) derived from the monomer (al) , the metal salt bond-containing polymer (A) may further comprise the constituent unit (a21) derived from the monobasic acid metal (meth) acrylate (a21) ; or may further comprise the constituent unit (a22) derived from the unsaturated monomer (a22); or may comprise both of the constituent units (a21) and (a22) . [0046]
The monobasic acid metal (meth) acrylate (a21) is represented by the following formula (II): [0047]
(Formula Removed)
wherein in the formula (II), M is magnesium, zinc or copper; R2 is a non-polymerizable monovalent organic group; and R3 is a hydrogen atom or a methyl group.
Examples of the organic group R2 include hydrocarbon groups such as monovalent saturated aliphatic groups having 2 to 30 carbon atoms, preferably 9 to 20 carbon atoms, monovalent unsaturated aliphatic groups having 2 to 30 carbon atoms, preferably 9 to 20 carbon atoms, saturated or unsaturated monovalent alicyclic groups having 3 to 20 carbon atoms, preferably 9 to 20 carbon atoms
and monovalent aromatic groups having 6 to 30 carbon atoms; and organic acid residues of monobasic acids formed from substitution products thereof. [0048]
Among these, preferable examples include hydrocarbon groups of saturated or unsaturated monovalent aliphatic hydrocarbon groups having 9 to 20 carbon atoms, saturated or unsaturated alicyclic hydrocarbon groups having 9 to 20 carbon atoms and organic acid residues of monobasic acids formed from substitution products thereof, in terms of resin viscosity, resin elusion property in the coating film and storage stability of the coating material. [0049]
Preferable examples of the organic group R2 include organic acid residues (R2) of monobasic acids (R1COOH) such as versatic acid (a mixture of carboxylic acids which have 9 to 11(mostly, 10) atoms and are represented by RaRbRcC-COOH [Ra, Rb and Rc are each independently an alkyl group]), palmitic acid, stearic acid, isostearic acid, oleic acid, linoleic acid, linolenic acid, abietic acid, neoabietic acid, pimaric acid, dehydroabietic acid, 12-hydroxystearic acid and naphthenic acid. With the above preferable examples, the metal salt bond-containing polymer (A) is readily synthesized and a coating film formed from the obtained antifouling composition shows antifouling properties with the
metal salt bond-containing polymer (A) gradually hydrolyzed from the coating film and moreover, burden of the hydrolysis on environment is decreased and higher durability of antifouling effects, good surface-renewability and excellent re-coating property in repair coating are obtained. [0050]
Specific examples of the CH2=C (R3)-COO-M-O-CO- in the monobasic acid metal (meth)acrylate (a21) are versatic acid zinc (meth)acrylate (CH2=C (R23)-COO-Zn-O-CO-(a versatic acid residue)); isostearic acid zinc (meth)acrylate (CH2=C(R23)-COO-Zn-O-CO-(an isostearic acid residue)); versatic acid copper (meth)acrylate (CH2=C (R23)-COO-Cu-O-CO-(a versatic acid residue));and isostearic acid copper (meth)acrylate (CH2=C (R23)-COO-Cu-O-CO-(an isostearic acid residue)). These monobasic acid metal (meth) acrylates (a21) are used singly or in combination of two or more kinds. [0051]
In the production of the metal salt bond-containing polymer (A) comprising the constituent unit (a21) derived from the monomer (a21), the monobasic acid metal (meth)acrylate (a21) is not necessarily used as a monomer. As long as the constituent unit (a21) is present in the resultant polymer, a production method of the polymer (A) is not particularly limited. [0052]
Examples of the "unsaturated monomer (a22)" include unsaturated compounds such as an alkyl(meth)acrylate, an alkoxyalkyl(meth)acrylate and a hydroxyalkyl(meth)acrylate. Preferable examples include an alkyl(meth)acrylate with alkyl groups having 1 to 20 carbon atoms, an alkoxyalkyl(meth)acrylate with alkoxy groups having 1 to 20 carbon atoms and with alkylene groups having 1 to 20 carbon atoms and a
hydroxyalkyl(meth)acrylate with hydroxyalkyl groups having 1 to 20 carbon atoms. [0053]
Examples of the alkyl(meth)acrylate include methyl(meth)acrylate, ethyl(meth)acrylate and butyl(meth)acrylate.
Examples of the alkoxyalkyl(meth)acrylate include methoxymethyl(meth)acrylate, 2-methoxyethyl(meth)acrylate, ethoxymethyl(meth)acrylate, ethoxyethyl(meth)acrylate, butoxymethyl(meth)acrylate, 3-methoxybutyl(meth)acrylate and 3-methyl-3-methoxybutyl(meth)acrylate.
An example of the hydroxyalkyl(meth)acrylate includes 2-hydroxyethyl(meth)acrylate. [0054]
Among these, preferable examples of the "unsaturated monomer (a22)" include methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate and
2-hydroxyethyl(meth)acrylate, considering properties of the coating film and durability of the resin elution from the coating film. [0055]
These "unsaturated monomers (a22)" may be used singly or in combination of two or more kinds. [0056]
The metal salt bond-containing polymer (A) comprises the constituent unit (al) usually in an amount of 5 to 100% by weight (provided that the content of the total constituent units in the polymer (A) is 100% by weight; this applies to hereinafter.), preferably 5 to 99.9% by weight and more preferably 20 to 99.9% by weight; and the constituent unit (a2) usually in an amount of 0 to 95% by weight, preferably 0.1 to 95% by weight and more preferably 0.1 to 80% by weight, considering the easiness of controlling elution rate of resin in the coating film. [0057]
In addition, 100% by weight of the constituent unit (a2) comprises, for example 0 to 90% by weight of the constituent unit (a21) derived from the monobasic acid metal(meth)acrylate (a21) and for example 100 to 10% by weight of the constituent unit (a22) derived from the unsaturated monomer (a22). [0058]
The number average molecular weight Mn of the metal salt
bond-containing polymer (A) (in terms of polystyrene standards, which is the same hereinafter; measured by GPC; measurement conditions: column; Super H2000 + H4000) is usually 1,000 to 100,000, preferably 1,000 to 10,000, considering resin viscosity and elution rate of resin in the coating film. [0059]
Further, the total amount of magnesium (Mg), zinc (Zn) and copper (Cu) contained in the metal salt bond-containing polymer (A) is usually 0.5 to 20% by weight, preferably 5 to 20% by weight (provided that the amount of the metal salt bond-containing polymer (A) is 100% by weight), because resin viscosity, storage stability of the coating material and elution of resin in the coating film are good. [0060]
The metal salt bond-containing polymer (A) can be produced by a hitherto known method. Specific production examples include:
(Method 1): a method comprising polymerizing the monomer (al) optionally with the monomer (a2) to produce the metal salt bond-containing polymer (A) ; and
(Method 2) : a method comprising allowing a copolymerizable monomer capable of deriving a divalent metal di (meth) acrylate (for example, an alkyl (meth) acrylate such as methyl methacrylate (MMA) , acrylic acid and methacrylic acid), a divalent metal oxide (for
example, ZnO, MgO and CuO) and water to contact (react) with one another in a solvent (for example, PGM, n-BuOH and xylene) and copolymerizing the resultant reaction mixture (a metal-containing reaction product) and the monomer (a22), optionally with the monomer (a21) , in the presence of an initiator (for example, AIBN, AMBN and t-butylperoctoate) , a chain transfer agent and the like to produce the metal salt bond-containing polymer (A) . [0061]
The antifouling coating composition of the present invention comprises an alicyclic hydrocarbon resin (B) having at least one functional group selected from the group consisting of an ester group, a hydroxyl group and a carboxyl group. [0062]
Examples of the ester group include an RCOO- group and an ROCO-group (R is an alkyl group). Examples of the alkyl group R include alkyl groups having 1 to 10 carbon atoms. [0063]
The alicyclic hydrocarbon resin (B) may comprise a single kind or two or more kinds of the ester group, the hydroxyl group and the carboxyl group. [0064]
The alicyclic hydrocarbon resin (B) may contain a structural
unit having a norbornene skeleton represented by the following
formula (bl):
[0065]
(Formula Removed)
[0066]
wherein m is an integer of from 1 to 20. [0067]
As the alicyclic hydrocarbon resin (B), an alicyclic hydrocarbon resin as described for example in [0029] to [0043] of patent document JP-A-2006-152205 can be employed. The alicyclic hydrocarbon resin (B) is obtained for example by copolymerizing a cyclopentadiene oligomer and a vinyl compound having a desired functional group under a usual reaction condition. [0068]
The cyclopentadiene oligomer is a cyclopentadiene oligomer represented by the following formula (b2): [0069]
(Formula Removed)
[0070]
wherein n is an integer of 0 to 20.
The examples include dicyclopentadiene, tricyclopentadiene, tetracyclopentadiene, pentacyclopentadiene and hexacyclopentadiene. These may be used singly or in combination of two or more kinds. The cyclopentadiene oligomer can be obtained by thermal treating of dicyclopentadiene (conditions: for example, 0.1 to 60 hours and temperatures of from 125 to 250°C.) [0071]
Examples of the vinyl compounds having an ester group include vinyl alcohol esters such as vinyl acetate and vinyl propionate; and (meth)acrylate esters such as methyl (meth)acrylate, ethyl (meth)acrylate and butyl (meth)acrylate. Examples of the vinyl compounds having a hydroxy group are vinyl compounds having a hydroxy group such as allyl alcohol and hydroxy ethyl (meth)acrylate. Examples of the vinyl compounds having a carboxylic group include vinyl carboxylic acids such as (meth)acrylic acid, maleic anhydride and maleic acid. These vinyl compounds may be used singly or in combination of two or more kinds. [0072]
The alicyclic hydrocarbon resin (B) is obtainable also by allowing a vinyl compound to react with a cyclopentadiene oligomer into which a functional group has been introduced.
In the case of the resin (B) having an ester group, the alicyclic hydrocarbon resin (B) is obtainable by half esterif ication of acid anhydride. [0073]
The number average molecular weight of the alicyclic hydrocarbon resin (B) (in terms of polystyrene standards, measured by GPC (Gel Permeation Chromatography) ) is preferably 150 to 2000, more preferably 200 to 1000. The number average molecular weight lower than the above range does not sometimes contribute to the increase in the strength of the resultant coating film. The number average molecular weight higher than the above range sometimes decreases leveling property in forming the coating film. [0074]
The softening point (JIS K 2207 ring and ball method) of the alicyclic hydrocarbon resin (B) is preferably 60 to 150°C, more preferably 75 to 150°C. The softening point lower than the above range does not sometimes contribute to the increase in the strength of the resultant coating film. The softening point higher than the above range sometimes decreases leveling property and flexibility in forming the coating film. [0075]
When the alicyclic hydrocarbon resin (B) has an ester group, the saponification value (JIS K 0070) is preferably 100 to 300 mgKOH/g, more preferably 150 to 200 mgKOH/g. When the
saponification value is lower than the above range, the compatibility with a coating material component is sometimes inferior. When the saponification value is higher than the above range, it is sometimes difficult to control slight solubility in seawater where hydrophilicity attributed to the ester group is not high. [0076]
When the alicyclic hydrocarbon resin (B) has a hydroxy group, the hydroxyl group value (JIS K 0070) is preferably 50 to 300 mgKOH/g, more preferably 200 to 250 mgKOH/g. When the hydroxy group is lower than the above range, it is sometimes difficult to ensure the slight-solubility in seawater. When the hydroxyl group value is higher than the above range, the compatibility with a coating material component is sometimes inferior. [0077]
When the alicyclic hydrocarbon resin (B) has a carboxyl group, the acid value is preferably 30 to 250 mgKOH/g, more preferably 50 to 200 mgKOH/g. When the acid value is lower than the above range, it is sometimes difficult to ensure the slight-solubility in seawater. When the acid value is higher than the above range, the alicyclic hydrocarbon resin (B) is sometimes so rigid that it becomes brittle. [0078]
Examples of commercially available products of the
alicyclic hydrocarbon resin (B) having an ester group include Quintone 1500 and Quintone 1525L (trade names; manufactured by ZEON CORPORATION) . Examples of a commercially available product of the alicyclic hydrocarbon resin (B) having a hydroxy group include Quintone 1700 (trade name; manufactured by ZEON CORPORATION).
[0079]
The alicyclic hydrocarbon resins (B) may be used singly or in combination of two or more kinds.
[0080]
The antifouling coating composition of the invention contains the alicyclic hydrocarbon resin (B) in an amount of preferably 0.1 to 100 parts by weight, more preferably 0.1 to 50 parts by weight, still more preferably 0.1 to 25 parts by weight based on 100 parts by weight of the metal salt bond-containing polymer (A) (solid content), because the coating film has decreased swelling and no blistering and maintains polishing degree.
[0081]
The antifouling coating composition applicable in freshwater environment of the invention comprises the metal salt bond-containing polymer (A) and the alicyclic hydrocarbon resin
(B) which are essential components, and may further comprise other components described in hereinafter.
[0082]

The antifouling coating composition of the present invention may contain an inorganic antifouling agent. The antifouling coating composition of the present invention containing the inorganic antifouling agent is desirable because the resultant coating film has excellent antifouling properties and properties of the coating film, in particular the crack resistance are excellent. [0083]
Examples of the inorganic antifouling agent include copper and/or an inorganic copper compound. With regard to the copper and/or inorganic copper compound, the average particle diameter and particle size distribution are not particularly limited. When the copper and/or inorganic copper compound has, for example, an average particle diameter of 6 to 50um, the antifouling coating film tends to have long-term antifouling properties such as excellent durability of hydrolysis and steady polishing degree (constant polishing degree) continuing for a long period. [0084]
The inorganic copper compound may be any one of inorganic-based copper compounds. The examples include cuprous oxide, copper thiocyanate (cuprous thiocyanate or copper rhodanate), basic copper sulfate, basic copper acetate, basic
copper carbonate and cupric hydroxide. These copper compounds can be used in place of copper or can be used singly or in combination of two or more kinds in combination with copper. [0085]
As the copper and/or inorganic copper compound, cuprous oxide is desirable because it provides the resultant coating film with excellent antifouling properties and properties of the coating film, in particular excellent crack resistance. [0086]
The inorganic antifouling agent is contained, based on 100 parts by weight of the polymer (A) (solid content) , in an amount of usually 0.1 to 500 parts by weight, preferably 0.1 to 300 parts by weight, in which case the resultant coating film has excellent antifouling properties and properties of the coating film, in particular excellent crack resistance. On the other hand, when the amount of the inorganic antifouling agent is less than the above range, the coating film tends to have an insufficient antifouling effect and the surface of the coating film tends to have inhibited renewability. When the amount of the inorganic antifouling agent is more than the above range, the coating film tends to have a crack. [0087]
The antifouling coating composition of the present
invention may contain an organic antifouling agent. The antifouling coating composition of the present invention containing the organic antifouling agent is preferable because the resultant coating film exhibits antifouling properties in particular in highly foul sea environment and durability of antifouling effect and surface-renewability are excellent. [0088]
In the present invention, it is particularly preferable that the organic antifouling agent is at least one compound selected from the group consisting of a metal-pyrithione represented by the following formula [III] and a derivative thereof (a pyrithione compound), a tri-organic boron, an amine complex thereof and 4,5-dichloro-2-n-octyl-4-isothiazoline-3-one, because antifouling properties of the coating film and storage stability of the coating material are excellent. [0089]
(Formula Removed)
[0090]
wherein in the formula [III], R1 to R4 are each independently represent a hydrogen atom, an alkyl group, an alkoxy group or a
halogenated alkyl group; M represents a metal such as Cu, Na, Mg, Zn, Ca, Ba, Pb, Fe and Al, preferably Cu and Zn considering durability of polishing degree of the coating film; and n represents a valence. [0091]
In the present invention, it is particularly preferable that the organic antifouling agent is at least one selected from the group consisting of copper pyrithione, zinc pyrithione, triphenylboron pyridine complex, 4-isopropyl pyridine-diphenylmethylborane complex and 4-5-dichloro-2-n-octyl-4-isothiazoline-3-one, because excellent storage stability of the coating material, polishing degree of the coating film and durability of antifouling properties are achieved in fine balance. [0092]
The organic antifouling agent is contained, based on 100 parts by weight of the polymer (A) (solid content), usually in an amount of 0.1 to 200 parts by weight, preferably 0.1 to 100 parts by weight, because the resultant antifouling coating film has good antifouling properties, in particular the durability of the antifouling properties is good (i.e., less polishing degree) and the resultant antifouling coating film has less burden on environment and excellent water resistance. [0093]

The extender pigment is a pigment which has a small refractive index and which will not hide a coated surface because it is transparent when mixed and kneaded with oil or varnish. The examples include zinc oxide, talc, silica, mica, clay, diatomaceous earth, calcium carbonate used also as an anti-settling agent, kaolin and aluminum white, white carbon used also as a frosting agent, aluminum hydroxide, magnesium carbonate, barium carbonate, barium sulfate. Among these, zinc oxide is preferable because it increases the strength of the coating film; and an extender pigment selected from the group consisting of talc, clay, diatomaceous earth and silica is preferable because it decreases stress inside the coating film. [0094]
These extender pigments may be used singly or in combination of two or more kinds. Further, depending on a type of an extender pigment, it is possible to control the polishing degree of the coating film. [0095]
The extender pigment is contained, based on 100 parts by weight of the metal salt bond-containing polymer (A) , usually in an amount of 0.1 to 400 parts by weight, preferably 0.1 to 300 parts by weight, in which case it is possible to obtain a coating material with extending effect at reduced cost while obtaining
a coating film that has transparency, is well-covered and has crack
resistance.
[0096]

As a coloring pigment, various hitherto known organic-based or inorganic-based pigments can be used. [0097]
Examples of the organic-based pigments include carbon black, naphthol red and phthalocyanine blue. [0098]
Examples of the inorganic-based pigments are red iron oxide, baryte powder, titanium white and yellow iron oxide. Various coloring agents such as a dye may be contained as well. [0099]
In the present invention, as the coloring pigments, it is particularly preferable that the inorganic-based coloring pigment is any of red iron oxide, titanium white and yellow iron oxide in terms of tinting strength. The organic pigment, too, is preferable because it provides the coating film with particularly brilliant color and less discoloration. [0100]
The coloring pigment is contained, based on 100 parts by weight of the metal salt bond-containing polymer (A) , usually in an amount of about 0.1 to 200 parts by weight, preferably about
0.1 to 100 parts by weight.
[0101]

The antifouling coating composition of the present invention may further contain an anti-sagging/anti-settling agent (thixotropic agent). [0102]
Examples of the anti-sagging/anti-settling agent (thixotropic agent) include salts such as Al, Ca or Zn salt of amine, steatic acid, lecithin, alkylsulfonic acid and the like; organic waxes such as polyethylene wax, amide wax, hydrogenated castor oil wax, polyamide wax and polyethylene oxide wax; and synthetic fine powder silica. Examples of the commercially available products include "Disparlon 305", "Disparlon 4200-20" and "Disparlon A630-20X", manufactured by Kusumoto Chemicals, Ltd. [0103]
The anti-sagging/anti-settling agent (thixotropic agent) is contained, based on 100 parts by weight of the metal salt bond-containing polymer (A), usually in an amount of 0.1 to 100 parts by weight, preferably about 0.1 to 50 parts by weight. [0104]
The antifouling coating composition of the present
invention may contain as a coating-film-forming component, a solid resin other than the polymer (A) (in the present invention, also referred to as "other solid resin") as long as not missing the object of the present invention. Examples of the "other solid resin" include a hardly water soluble or water insoluble resin and a water soluble resin. Examples of the hardly water soluble or water insoluble resin include a terpene phenol resin, an acrylic resin, an acrylic silicone resin, an unsaturated polyester resin, a fluorine resin, a polybutene resin, a silicone rubber, an urethane resin (rubber), an epoxy resin, a polyamide resin, a vinyl chloride based copolymer resin, a chlorinated rubber (resin), a chlorinated olefin resin, styrene/butadiene copolymer resin, ethylene/vinyl acetate copolymer resin, vinyl chloride resin, an alkyd resin, a coumarone resin and a petroleum resin. Although being a water insoluble resin, the terpene phenol resin has less negative influence on the polishing degree of the coating film. An example of the commercially available product of the terpene phenol resin includes terpene phenol YP 90L (trade name; manufactured by Yasuhara Chemical Co., Ltd.). [0105]
Examples of the water soluble resins include a rosin (for example, "rosin WW" (trade name) ) , a monocarboxylic acid and a salt thereof. Examples of the mobocarboxylic acids include aliphatic acids having about 9 to 19 carbon atoms and a naphthenic acid.
Examples of the salts of the monocarboxylic acids include a Cu salt, a Zn salt and a Ca salt. The rosins include gum rosin, wood rosin, tall oil rosin; any of these can be used in the invention. These water soluble resins can be used singly or in combination of two or more kinds. [0106]
The other solid resin is preferably a rosin and a terpene phenol resin in terms of maintaining the polishing degree of the coating film. [0107]
The other solid resin mentioned above is contained in an amount of usually about 0.1 to 100 parts by weight, preferably about 0.1 to 50 parts by weight based on 100 parts by weight of the metal salt bond-containing polymer (A). [0108]
The antifouling coating composition of the present invention may further contain, in addition to the above components, a thixotropy-imparting agent, an inorganic dehydrating agent (a stabilizer), a fungicide, an anti-aging agent, an antioxidant, an antistatic agent, a flame retardant, a thermal conductive modifier and an adhesion-imparting agent. [0109]
In the antifouling coating composition of the present invention, each of the above components is usually dissolved or dispersed in a solvent. As the solvent, various solvents usually blended with an antifouling coating material such as aliphatic based solvents, aromatic based solvents, ketone based solvents, ester based solvents or ether based solvents can be used. Examples of the aromatic based solvents include xylene and toluene. An example of the ketone based solvents includes methylisobutylketone (MIBK). Examples of the ether based solvents include propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate (PMAC). [0110]
The antifouling coating composition of the present invention can be produced from the metal salt bond-containing polymer (A) and the aliphatic hydrocarbon resin (B), which are essential components, and optionally the above other components as starting materials. These starting materials are blended at a time or in an arbitrary order, and stirred/mixed properly by a hitherto known method. [0111]
The stirring and mixing of the components can be performed with hitherto known mixing/stirring machines such as a Ross mixer, a planetary mixer and a versatile Shinagawa mixer.
[0112]
[Antifouling Coating Film Applicable In Freshwater Environment, etc.]
The antifouling coating film applicable in freshwater environment of the present invention is formed from the antifouling coating composition applicable in freshwater environment. [0113]
The substrate with the antifouling coating film applicable in freshwater environment of the invention has its surface coated with the antifouling coating film applicable in the freshwater environment. [0114]
The substrate is preferably an underwater structure or an outer board of a ship. [0115]
Embodiments in which the antifouling coating film applicable in the freshwater environment of the present invention is formed on the surface of the substrate (embodiments in which the surface of the substrate is coated with the antifouling coating film applicable in the freshwater environment of the present invention) are exemplified by an embodiment in which the antifouling coating film applicable in the freshwater environment of the present invention is directly formed on the surface of the
substrate and an embodiment in which the antifouling coating film applicable in the freshwater environment of the present invention is formed on a coating film which has already been formed on the surface of the substrate. [0116]
In the invention, the method for forming the antifouling coating film applicable in freshwater environment on the surface of the substrate comprises the steps of coating or impregnating the surface of the substrate with the antifouling coating composition applicable in freshwater environment, curing the composition and thereby forming a coating film. [0117]
In the invention, the method for preventing the substrate from fouling comprises the steps of coating or impregnating the surface of the substrate with the antifouling coating composition applicable in freshwater environment, curing the composition and thereby forming an antifouling coating film. [0118]
The coating film formed by applying and curing the antifouling coating composition applicable in freshwater environment according to the present invention on surfaces of substrates such as hulls and underwater structures hardly has peeling, blistering and the like while immersed in underwater (namely, seawater or freshwater), even if temporarily immersed
for example in a ship yard of river regions of China during construction of a ship. Therefore, the coating film according to the present invention, which is applicable not only in seawater environment but also in freshwater environment, is suited for a coating film "applicable in freshwater environment". [0119]
The antifouling coating composition applicable in freshwater environment according to the present invention can form a coating film that exhibits excellent antifouling properties against various organisms inhabiting seawater environment or freshwater environment: for example, those inhabiting seawater environment, such as shellfishes including barnacles, mussel and oyster and coelenterate such as serpula. Therefore, it can be expected that the antifouling coating composition applicable in freshwater environment according to the present invention is applied to antifouling treatment of a hull and an underwater structure constructed and traveled in seawater (salt water) environment and in freshwater (plain water) environment. [0120]
The antifouling treatment of a hull, in particular a ship outer board contacting with freshwater, and an underwater structure, in particular a surface of the underwater structure, is performed by applying the antifouling coating composition applicable in freshwater environment according to the present
invention to the hull constructed in freshwater environment or to the surface of the freshwater environment underwater structure and thereby forming the antifouling coating film. [0121]
With the application of the method for forming the antifouling coating film or the antifouling method into a ship or underwater structure constructed in freshwater environment, it is possible to obtain a ship or an underwater structure such that the outer board of the ship contacting with freshwater or the surface of the underwater structure for freshwater environment is coated with the antifouling coating film formed from the antifouling coating composition applicable in freshwater environment according to the present invention.
Examples [0122]
Hereinafter, the present invention is described more specifically with reference to Examples. In no way is the present invention limited by the Examples. [0123]
In the following descriptions such as in Examples and Comparative Examples, "part" denotes part by weight as long as not missing the subject. [0124]
Ingredients of the antifouling coating composition are described in detail below. [0125]
Table 1
(Table Removed)
[0126]
Methods for measuring various properties in Examples and the like are as follows. [0127]
The Gardner viscosity was measured at 35% by weight concentration of the resin content at 25°C in accordance with 4.3 of JIS K7233, as described in patent document JP-A-2003-55890 and the like. [0128]
A solid content refers to a heating residue generated after heating and drying a reaction mixture, a coating material, an uncured coating film and the like containing a polymer, a solvent and the like so as to volatilize the solvent and the like. The heating residue usually contains a pigment or the like in addition to the resin content and constitutes a coating-film-forming component. The calculation of the solid content is made by counting, as the solid content, a monomer or the like (see Table 2) which is contained in the coating material and can react to form a resin (the solid content). [0129]
Measurements of Number Average Molecular Weight (Mn) and Weight Average Molecular Weight (Mw)>
The weight average molecular weight (Mw) of a resin such as a metal-containing resin was measured by HLC-8120 GPC. In the measurement, two separation columns (α-M) of TSK-gel α-Type were used and DMF (dimethylformamide) to which 20 mM of LiBr was blended was used as an eluent. The weight average molecular weight (Mw) was determined in terms of polystyrene conversion. [0130]
The number average molecular weight (Mn) of a resin was determined by the above-mentioned GPC in terms of polystyrene conversion. [0131]
[Production Example 1] (Production Of Metal-Containing Monomer A-l)
A four neck flask equipped with a condenser, a thermometer, a dropping funnel and a stirrer was charged with 85.4 parts of propylene glycol methyl ether (PGM) and 40.7 parts of zinc oxide, and the temperature was increased to 75°C with stirring. Subsequently, from the dropping funnel, a mixture consisting of 50.0 parts of methyl methacrylate (MMA), 36.1 parts of acrylic acid (AA) and 5 parts of water was dropped at a constant speed over 3 hours. After finishing the dropping, the state of the reaction solution changed from opalescent to transparent. After further stirring for 2 hours, 36 parts of propylene glycol methyl ether (PGM) was added thereto to obtain a transparent mixture
solution A containing a metal-containing monomer A-l. [0132]
The solid content (the metal-containing monomer A-l) in the resultant mixture solution A was 44.8 % by weight. The blended composition and the like are shown in Table 2. [0133]
[Production Example 2] (Production Of Metal-Containing Monomer A-2)
The same procedure as in Production Example 1 was performed, except that 20.2 parts of magnesium oxide was used instead of 40.7 parts of zinc oxide, whereby a transparent mixture solution E containing a metal-containing monomer A-2 was obtained. [0134]
The solid content (the metal-containing monomer A-2) in the resultant mixture solution E was 44.6 % by weight. The blended composition and the like are shown in Table 2. [0135] Table 2 Production Examples of Metal bond-containing polymer A
(Table Removed)
(Note): MMA/ methyl methacrylate AA/acrylic acid
[0136]
[Production Example 3]
(Production of Metal salt bond-containing polymer (Al))
A four neck flask equipped with a condenser, a thermometer, a dropping funnel and a stirrer was charged with 15 parts of propylene glycol methyl ether, 57 parts of xylene and 4 parts of ethyl acrylate, and the temperature was increased to 100°C with stirring. [0137]
Subsequently, from the dropping funnel, a transparent mixture consisting of 1 part of methyl methacrylate (MMA), 70.2 parts of ethyl acrylate (EA) ,5.4 parts of 2-methoxyethyl acrylate (2-MEA), 52 parts of the mixture solution A obtained in the Production Example 1, 10 parts of xylene, 1 part of a chain transfer agent ("Nofmer MSD", manufactured by NOF CORPORATION),2.5 parts of azobisisobutyronitrile (AIBN; manufactured by Nippon Hydrazine Industry Co., Ltd.) and 7 parts of azobismethylbutyronitrile (AMBN; manufactured by Nippon Hydrazine Industry Co., Ltd. ) was dropped at a constant speed over 6 hours (Dropping step I) . [0138]
After finishing the dropping, 0 . 5 part of t-butyl peroctoate (TBPO) and 7 parts of xylene were dropped over 30 minutes and
stirred for one and a half hour. Thereafter, 4.4 parts of xylene was added to obtain a resin composition which contained a metal salt bond-containing polymer (Al) and which was free from insoluble substances and was pale-yellow and transparent. The molecular weight (Mn) of the resultant metal salt bond-containing polymer (Al) and properties (Gardner viscosity and the solid content (% by weight)) of the reaction mixture containing the polymer (Al) are shown in Table 3. [0139]
[Production Example 4] (Production Of Metal Salt Bond-Containing Polymer (A2)))
A metal salt bond-containing polymer (A2) was produced in the same manner as in Production Example 3, except that dropping components in Dropping step I were changed as shown in Table 3. The properties of the metal salt bond-containing polymer (A2) and of the reaction mixture containing the polymer (A2) were evaluated in the same manner as in Production Example 3 (Production Example of the Polymer (Al)). The results are shown in Table 3. [0140]
Table 3
(Table Removed)
[0141]
[Example 1]

Into a 1000 ml plastic container, xylene (88 g) and SOLVESSO 150 (32 g) were charged as a solvent. Subsequently, the Metal salt bond-containing polymer (Al) obtained in Production Example 4 (280 g) and an alicyclic hydrocarbon resin (Quinton 1500; 4 g) were added. These were dispersed with a paint shaker until they were homogenous. [0142]
Subsequently, Talc FC-1 (136 g), zinc oxide (144 g), Novaperm Red F5RK (4 g), RED IRON OXIDE BB (12 g), PK boron (56 g) , Zinc Omadine (16 g) and Disparlon 4200-20X (8 g) were blended and 200 g of glass beads were added. These were dispersed with a paint shaker over 1 hour.
[0143]
Further, Disparlon A630-20X (16 g) was added and the resultant was dispersed with a paint shaker over 10 minutes to obtain a mixture. The mixture was filtered through an 80-mesh filtering net, whereby an antifouling coating composition was prepared. [0144]

The antifouling coating composition obtained in Example 1 was applied, with an applicator, directly on a hard vinyl chloride resin plate (50 mm x 50 mm x 1.5 mm-thickness) which had not been subjected to primer treatment so that the dried film thickness would be 300 µm, which was followed by drying. The obtained test plate with the coating film was immersed in plain water at 35°C for one month. Thereafter, the outer appearance of the coating film was visually observed and evaluated under the following criterion. The result is shown in Table 4. [0145]
AA: No change in the outer appearance (no blistering, crack, swelling or the like). [0146]
CC: Significant swelling of the coating film. [0147]

The antifouling coating composition obtained in Example 1 was directly applied, with an applicator, on a hard vinyl chloride resin plate (50 mm x 50 mm x 1.5 mm-thickness) which had not been subjected to primer treatment so that the dried film thickness would be 150 µm, which was followed by drying. The obtained test plate with the coating film was immersed in plain water at 35°C for one month. Thereafter, the plate was attached to a rotating drum set up in seawater in Nagasaki bay, Nagasaki Prefecture. The drum was rotated at a circumferential velocity of 15 knot. Then, the film thickness polished per month (A total amount µm of the polishing degree of the coating film counted immediately after the set-up; the polishing degree of the coating film) was measured over four months. The result is shown in Table 4.
[0148]

An epoxy primer (epoxy AC paint; trade name: "Bannoh 500", manufactured by Chugoku Marine Paints Ltd. ) was applied on a sand blast-treated steel plate (70 mm x 150 mm x 1.6 mm-thickness) so that the dried film thickness would be 150 µm, and then an epoxy binder (an epoxy base binder paint; trade name: "Bannoh 500N", manufactured by Chugoku Marine Paints Ltd.) was applied thereon
so that the dried film thickness would be 100 µm. Subsequently, the antifouling coating composition obtained in Example 1 was further applied thereon so that the dried film thickness would be 100 µm, whereby a test plate was prepared. The applying interval between each of the coating films was set at 1 day. The test plate was set up in a sunshine weather meter device and sunshine carbon arc optical source was applied for 78 hours. Then, the antifouling coating composition obtained in Example 1 was applied on the coating film again so that the dried film thickness would be 100 µm, which was followed by drying. The test plate with the coating film obtained was immersed in plain water at 40°C and 30 days later, the adhesion (knife test) was observed. The result is shown in Table 4. [0149]
The antifouling coating composition obtained in Example 1 was applied, with an applicator, directly on a hard vinyl chloride resin plate (50 mm x 50 mm x 1.5 mm-thickness) which had not been subjected to primer treatment so that the dried film thickness would be 150 µm. The obtained test plate with the coating film was attached to a rotating drum set up in seawater in Nagasaki bay, Nagasaki Prefecture. The drum was rotated at a circumferential velocity of 15 knot. Then, the film thickness polished per month (A total amount µm of the polishing degree of
the coating film counted immediately after the set-up; the
polishing degree of the coating film) was measured over four months.
The result is shown in Table 4.
[0150]

An epoxy base anticorrosive paint (epoxy AC paint; trade name: "Bannoh 500", manufactured by Chugoku Marine Paints Ltd.) was applied on a sand blast-treated steel plate (height 300 mm x width 100 mm x 3.2 mm-thickness) so that the dried film thickness would be 150 urn, and then an epoxy base binder coating material (brand name: "Bannoh 500N", manufactured by Chugoku Marine Paints Ltd. ) was applied thereon so that the dried film thickness would be 100 urn. [0151]
Subsequently, the antifouling coating composition obtained in Example 1 was applied thereon one time so that the dried film thickness would be 150 µm, which was followed by drying, whereby a test plate with a coating film was prepared. The applying interval between each of the coating material (for example, "Bannoh 500") and another material overcoating the surface of the coating material (for example, "Bannoh 500N") was set at 1 day/1 coat. [0152]
The test plate was dried at room temperatures for seven days.
Then, the test plate was immersed statically at Nagasaki Bay,
Nagasaki Prefecture for six months, during which the adhesion
areas (%) of adhesive organisms per month was investigated. The
result is shown in Table 4.
[0153]
The evaluation criterion for the static antifouling
property (the evaluation criterion for adhesion areas of aquatic
organisms) is as follows.
[0154]
0: no adhesion of aquatic organisms
0.5: adhesion area of aquatic organisms is approximately 10 % 1: adhesion area of aquatic organisms is approximately 20 % 2: adhesion area of aquatic organisms is approximately 30 % 3: adhesion area of aquatic organisms is approximately 40 % 4: adhesion area of aquatic organisms is approximately 50 % 5: adhesion area of aquatic organisms is approximately 100 %
[0155]
[Examples 2 to 14 and Comparative Examples 1 to 4]
Antifouling coating compositions were produced in the same
manner as in Example 1 except that the blending compositions were
changed as shown in Table 2. Each of the antifouling coating
compositions was evaluated in the same manner as in Example 1.
The results are shown in Table 4. [0156]
Table 4
(Table Removed)

CLAIMS
1. An antifouling coating composition applicable in
freshwater environment, which comprises:
a metal salt bond-containing polymer (A) comprising a constituent unit (al) derived from a (meth) acrylic acid metal salt monomer (al) represented by the formula (I):

wherein, M is magnesium, zinc or copper; and R1s each independently represent a hydrogen atom or a methyl group, and
an alicyclic hydrocarbon resin (B) having at least one group selected from an ester group, a hydroxyl group and a carboxyl group.
2. The antifouling coating composition applicable in freshwater environment according to claim 1, wherein the metal salt bond-containing polymer (A) is a copolymer further comprising a constituent unit (a2) derived from an unsaturated monomer (a2) copolymerizable with the monomer (al) and the constituent unit (al) is contained in an amount of 5 to 100% by weight and the constituent unit (a2) is contained in an amount of 0 to 95% by weight.
3. The antifouling coating composition applicable in
freshwater environment according to claim 1 or 2, which comprises 0.1 to 100 parts by weight of the alicyclic hydrocarbon resin (B) based on 100 parts by weight of the metal salt bond-containing polymer (A).
4. The antifouling coating composition applicable in freshwater environment according to any one of claims 1 to 3, which further comprises an extender pigment.
5. The antifouling coating composition applicable in freshwater environment according to claim 4, wherein the extender pigment is zinc oxide.
6. The antifouling coating composition applicable in freshwater environment according to any one of claims 1 to 5, which further comprises an inorganic antifouling agent.
7. The antifouling coating composition applicable in
freshwater environment according to claim 6, wherein the inorganic
antifouling agent is cuprous oxide.
8. The antifouling coating composition applicable in
freshwater environment according to any one of claims 1 to 7, which
further comprises an organic antifouling agent.
9. The antifouling coating composition applicable in
freshwater environment according to claim 8, wherein the organic
antif ouling agent is at least one compound selected from the group
consisting of a pyrithione compound, a tri-organic boron, an amine
complex thereof and
4,5-dichloro-2-n-octyl-4-isothiazoline-3-one.
10. The antifouling coating composition applicable in freshwater environment according to any one of claims 1 to 9, which further comprises the other solid resin.
11. The antifouling coating composition applicable in freshwater environment according to claim 10, wherein the other solid resin is a rosin and/or a terpene phenol resin.
12. An antif ouling coating film applicable in freshwater environment formed from the antifouling coating composition applicable in freshwater environment according to any one of claims 1 to 11.
13. A substrate with an antifouling coating film applicable in freshwater environment, wherein the surface of the substrate is coated with the antifouling coating film applicable
in freshwater environment according to claim 12.
14. The substrate with an ant;fouling coating film applicable in freshwater environment according to claim 13, wherein the substrate is an underwater structure or an outer board of a ship.
15. A method for forming an antifouling coating film applicable in freshwater environment on a substrate, which method comprises the steps of coating or impregnating the surface of the substrate with the antifouling coating composition applicable in freshwater environment according'to any one of claim 1 to 11, curing the composition and thereby forming a coating film.
16. A method for preventing a substrate from fouling, which method comprises the steps of coating or impregnating the surface of the substrate with the antifouling coating composition applicable in freshwater environment according to any one of claims 1 to 11, curing the composition and thereby forming an antifouling coating film.