JP2012050909A - Method of coating underwater structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of coating an underwater structure which can form a coating film having high smoothness and achieve smoothness of the coating film and coating workability by using a specific solvent in airless spray coating without adding new processes, such as a polishing process.SOLUTION: In the method of coating an underwater structure which applies an antifouling coating composition to the underwater structure as an object to be coated, the antifouling coating composition contains 25-55 vol.% organic solvent in coating, the organic solvent contains 80-100 vol.% organic solvent having a relative evaporation rate of 30-300 with respect to the total amount of the organic solvent, and the antifouling coating composition is applied to the object to be coated by the airless spray coating and its discharge pressure in the airless spray coating is 8 MPa or more.

Description

  The present invention relates to a coating method suitable for coating an underwater structure.

  In an underwater structure that is installed or used in water such as the sea or river, an anticorrosion coating is generally provided for the purpose of preventing corrosion of the substrate, and the anticorrosion coating is formed on the anticorrosion coating. An antifouling coating film having anti-adhesion performance for marine organisms is provided. And the smoothness of these coating films will have various influences on an underwater structure. For example, in the case of a ship, when the smoothness of the coating film is low, there is a problem that the frictional resistance increases and the energy consumption during ship operation increases. Further, for example, in a bridge or the like, the low smoothness of the coating film results in an increase in the number of places where marine organisms can be attached, which may increase the damage caused by the attachment of marine organisms.

  Some studies have been made on the method of smoothing the surface of a coating film in an underwater structure. For example, Japanese Patent Application Laid-Open No. Sho 61-254271 (Patent Document 1) describes a method of smoothing the surface of a submerged part outer plate of a ship. The method of Patent Document 1 is characterized in that the surface of the submerged part outer plate of a ship is polished using a brush-like object driven by power. However, since this method is a method of improving smoothness by mechanical polishing, there is a problem that a new process called a polishing process is added, equipment costs increase, and man-hour management increases.

  JP 59-189176 (Patent Document 2) discloses an antifouling paint containing a leafing type copper flake pigment and / or a leafing type copper alloy flake pigment having an average particle diameter of 1 to 300 μm and a thickness of 0.05 to 10 μm. A composition is described. According to the present invention, by using a leafing type flake pigment, the flake pigment is oriented and laminated on the surface of the coated film to obtain a smooth coated surface, and the metal flake pigment also exhibits antifouling properties. It is an invention. However, such leafing-type flake pigments have the disadvantages that cracking or chipping is likely to occur during the production of the paint, and the workability in producing the paint is inferior.

  In general, an antifouling coating film used in painting an underwater structure has a function of preventing adhesion of marine organisms by the elution of specific components contained in the coating film. Therefore, such an antifouling coating film is required to have a very thick film thickness (for example, a film thickness of 100 to 300 μm) in order to maintain the antifouling function for a long period of time. Airless spray coating is a coating method capable of coating a coating composition having a high viscosity as a thick film. However, in the method of coating a thick film by a single coating, the smoothness is likely to be lowered, and there are many technical problems in painting workability such as sagging.

  Here, in the case of painting using a general antifouling paint composition, in order to improve the smoothness, a means of painting by reducing the viscosity of the paint using a large amount of a diluent solvent can be considered. However, if a large amount of diluted solvent is used, the coating film thickness may be reduced. In this case, if the coating film thickness is increased, sagging is likely to occur due to a decrease in the coating viscosity, resulting in a coating operation. There is a problem that the property is inferior.

Japanese Patent Laid-Open No. 61-254271 JP 59-189176

  An object of the present invention is to solve the above-described problems of the prior art. More specifically, the present invention provides smoothness by applying a specific amount of a specific solvent in airless spray coating and applying a discharge pressure higher than a specific pressure without increasing a new process such as a polishing process. It is an object of the present invention to provide a coating method capable of forming a high coating film and further achieving both smoothness of the coating film and coating workability.

The present invention
A coating method for coating an antifouling paint composition with an underwater structure as a coating,
This antifouling paint composition contains 25 to 55% by volume of an organic solvent at the time of painting,
The organic solvent contains an organic solvent having a relative evaporation rate of 30 to 300 in a range of 80 to 100% by volume with respect to the total amount of the organic solvent,
This antifouling paint composition is applied to an object by airless spray coating, and the discharge pressure at the time of airless spray coating is 8 MPa or more.
An underwater structure coating method is provided, which solves the above problems.

  The discharge pressure is more preferably 12 MPa or more.

  Moreover, it is more preferable that the antifouling coating composition contains 25 to 45% by volume of an organic solvent during coating.

  Further, the viscosity of the antifouling coating composition is more preferably 90 to 120 KU.

The antifouling coating composition contains a binder resin, an antifouling agent, and an organic solvent,
This binder resin has the following general formula (1):

［式（１）中、Ｘは、

で表される基であり、ｋは０または１であり、Ｙは炭化水素であり、Ｍは２価金属であり、Ａは一塩基酸の有機酸残基を表す。］
で示される基を側鎖に有するアクリル樹脂であるのがより好ましい。

[In Formula (1), X is

K is 0 or 1, Y is a hydrocarbon, M is a divalent metal, and A represents an organic acid residue of a monobasic acid. ]
It is more preferable that it is an acrylic resin having a group represented by

［式（２）中、Ｒ¹、Ｒ²、Ｒ³は、同一または異なって、炭素数１〜２０の炭化水素残基を表す。］
で表される基をさらに有する樹脂であるのが、より好ましい。 The acrylic resin has, in the side chain, the following general formula (2):

Wherein ^{(2), R 1, R} 2, R 3 are the same or different and each represents a hydrocarbon residue having 1 to 20 carbon atoms. ]
It is more preferable that the resin further has a group represented by:

  In the present invention, an antifouling coating composition containing 25 to 55 vol% of an organic solvent containing 80 to 100 vol% of an organic solvent having a relative evaporation rate of 30 to 300 based on the total amount of the organic solvent at the time of coating. , Discharge pressure at the time of airless spray coating: By coating in a state of 8 MPa or more, a coating film having high smoothness can be obtained even with a film thickness of about 100 to 300 μm, and sagging is generated. It was also possible to ensure good paint workability.

  The coating method of the present invention is a coating method for coating an antifouling paint composition using an underwater structure as an object to be coated. The antifouling coating composition that can be used in the coating method of the present invention is particularly limited as long as it can perform airless spray coating and has antifouling performance required for coating applications of underwater structures. It can be used without being done. Examples of such an antifouling coating composition include an antifouling coating composition containing at least a binder resin and an antifouling agent.

Antifouling paint composition Examples of the antifouling paint composition that can be used in the coating method of the present invention include an antifouling paint composition containing a binder resin and an antifouling agent. Such an antifouling coating composition may further contain organic polymer particles as necessary. In the coating method of the present invention, the antifouling coating composition contains the organic solvent contained in the binder or additive, and the antifouling coating composition itself further adjusts the amount and viscosity of the organic solvent during coating. These may contain 25 to 55% by volume of an organic solvent at the time of coating, and the organic solvent may contain an organic solvent having a relative evaporation rate of 30 to 300 with respect to the total amount of the organic solvent. It is made to contain -100 volume%.

It does not specifically limit as binder resin contained in binder resin antifouling paint composition, According to the desired objective, it can select suitably from various antifouling resin. Specific examples of such binder resin include, for example, acrylic resin, polyester resin, chlorinated rubber, polyvinyl acetate, poly (meth) acrylic acid alkyl ester, alkyd resin, polyvinyl chloride, chlorinated paraffin, polyvinyl ether, polypropylene seba. Examples thereof include Kate, partially hydrogenated terphenyl, polyether polyol, silicone oil, wax, petrolatum, liquid paraffin, rosin, hydrogenated rosin, naphthenic acid, fatty acid, and divalent metal salts thereof. These resins may be used alone or in combination of two or more.

  In the present invention, it is preferable to use an acrylic resin as the binder resin. And when using an acrylic resin as binder resin, following General formula (1):

It is preferable to use an acrylic resin (hereinafter referred to as an acrylic resin (A)) having a group represented by Where X is

K is 0 or 1, Y is a hydrocarbon, M is a divalent metal, and A represents an organic acid residue of a monobasic acid.

  The acrylic resin (A) exhibits a property of gradually hydrolyzing in water (particularly in seawater) due to the hydrolyzability of the metal ester bond of the group represented by the general formula (1). As a result, the antifouling coating film formed from the antifouling coating composition using the acrylic resin as a binder resin is self-polished by immersion in water, whereby the antifouling component is continuously released from the coating film surface. Thus, the antifouling performance is exhibited until the coating film is completely consumed.

  As an acrylic resin (A) used by this invention, it has the group represented by the said General formula (1) in a side chain as a hydrolysable group, and the group represented by the following General formula (2) is made into a side chain. An acrylic resin that does not have (hereinafter referred to as “acrylic resin (A1)”) and a group represented by the above general formula (1) and a group represented by the following general formula (2) as a hydrolyzable group An acrylic resin in the chain (hereinafter referred to as acrylic resin (A2)) and the like can be given. These may be used alone or in combination of two or more. Moreover, you may use together with an acrylic resin (A1) and an acrylic resin (A2). In the present specification, “acrylic resin” means a resin in which at least a part of the resin is composed of structural units derived from (meth) acrylic acid or a derivative thereof or (meth) acrylic acid ester. The (meth) acrylic acid derivative includes a (meth) acrylic acid metal salt.

[In the above general formula (2), R ¹ , R ² and R ³ are the same or different and represent a hydrocarbon residue having 1 to 20 carbon atoms. ]

Acrylic resin (A1)
The acrylic resin (A1) is an acrylic resin having a group represented by the general formula (1) in the side chain as a hydrolyzable group and not having a group represented by the general formula (2) in the side chain. is there. Typically, it is an acrylic resin having only a group represented by the general formula (1) as a hydrolyzable group in the side chain. In the general formula (1), M is a divalent metal, and examples thereof include 3A to 7A, 8, 1B to 7B group elements in the periodic table. Especially, it is preferable that M is copper and zinc.

  In the general formula (1), A is an organic acid residue of a monobasic acid. Examples of preferable monobasic acids include monobasic cyclic organic acids. The monobasic cyclic organic acid is not particularly limited, and examples thereof include those having a cycloalkyl group such as naphthenic acid, resin acids such as tricyclic resin acids, and salts thereof. The tricyclic resin acid is not particularly limited, and examples thereof include a monobasic acid having a diterpene-based hydrocarbon skeleton. Examples of such a tricyclic resin acid include abiethane, pimarane, isopimarane, and labdane skeletons. The compound which has can be mentioned. More specifically, for example, abietic acid, neoabietic acid, dehydroabietic acid, hydrogenated abietic acid, parastrinic acid, pimaric acid, isopimaric acid, levopimaric acid, dextropimaric acid, sandaracopimalic acid, and salts thereof Can be mentioned. Of these, abiotic acid, hydrogenated abietic acid, and salts thereof are preferable because hydrolysis is appropriately performed and long-term antifouling properties are excellent, as well as excellent crack resistance and easy availability of the coating film. .

  Furthermore, preferable monobasic cyclic organic acids include those having an acid value of 120 to 220 mgKOH / g. By using a monobasic cyclic organic acid having an acid value of 220 mgKOH / g or less, the viscosity of the resulting acrylic resin (A1) can be lowered, and the solvent content of the resulting paint can be reduced. This is because the viscosity of the acrylic resin (A1) is largely due to the interaction between the functional groups represented by the general formula (1). The acrylic resin (A1) obtained by using a monobasic cyclic organic acid having an acid value of 220 mgKOH / g or less tends to increase the steric repulsion of the monobasic cyclic organic acid, and this steric repulsion is represented by the general formula (1). It seems that there exists a function which inhibits interaction between the functional groups shown, As a result, the viscosity of an acrylic resin (A1) can be reduced. Moreover, when an acid value is less than 120 mgKOH / g, the obtained acrylic resin (A1) becomes too hydrophobic and hydrolysis of the resulting coating film may not proceed.

  The monobasic cyclic organic acid does not need to be highly purified, and for example, pine resin, pine resin acid, and the like can be used. Examples of such include rosins, hydrogenated rosins, disproportionated rosins, and naphthenic acid. The rosins here are gum rosin, wood rosin, tall oil rosin and the like. Rosin, hydrogenated rosin and disproportionated rosin are preferred in that they are inexpensive and easily available, have excellent handling properties and exhibit long-term antifouling properties. These monobasic cyclic organic acids may be used alone or in combination of two or more.

  Among the monobasic acids that can be used in the present invention, those other than the above monobasic cyclic organic acids include, for example, acetic acid, propionic acid, butyric acid, lauric acid, stearic acid, linoleic acid, oleic acid, chloroacetic acid, fluoroacetic acid, C1-C20 things, such as valeric acid, etc. can be mentioned. These monobasic acids may be used alone or in combination of two or more.

  Y in the general formula (1) is not particularly limited as long as it is a hydrocarbon. For example, when a dibasic acid such as phthalic acid, succinic acid or maleic acid is added to a polymerizable unsaturated organic acid monomer Can be mentioned.

  The method for producing the acrylic resin (A1) is not particularly limited. For example, (a) a resin obtained by polymerizing a polymerizable unsaturated organic acid and another copolymerizable unsaturated monomer; , A method of reacting a monobasic acid and a metal compound, (b) reacting a polymerizable unsaturated organic acid, a metal compound and a monobasic acid, or a metal salt of a polymerizable unsaturated organic acid and a monobasic acid And a method of polymerizing the obtained metal-containing unsaturated monomer and another copolymerizable unsaturated monomer, and the like.

  The polymerizable unsaturated organic acid in the above methods (a) and (b) is not particularly limited, and examples thereof include a polymerizable unsaturated organic acid having one or more carboxyl groups. More specifically, for example, unsaturated monobasic acids such as (meth) acrylic acid; unsaturated dibasic acids such as maleic acid and monoalkyl esters thereof, itaconic acid and monoalkyl esters and monoalkyl esters thereof; Unsaturated monobasic acids such as a maleic acid adduct of 2-hydroxyethyl methacrylate, a phthalic acid adduct of 2-hydroxyethyl (meth) acrylate, and a succinic acid adduct of 2-hydroxyethyl (meth) acrylate Examples thereof include dibasic acid adducts of hydroxyalkyl esters. These polymerizable unsaturated organic acids may be used alone or in combination of two or more. In the method (b), a part or all of the metal-containing unsaturated monomer may be replaced with a divalent metal di (meth) acrylate. When the divalent metal di (meth) acrylate is used, the resin has a crosslinked structure through the group represented by the general formula (1), but such a resin can also be used.

  The other copolymerizable unsaturated monomer is not particularly limited, and examples thereof include (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylic acid i. -Propyl, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, (meth) acryl (Meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the ester moiety such as stearyl acid; carbon number in the ester moiety such as 2-hydroxypropyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate is 1 ~ 20 hydroxyl group-containing (meth) acrylic acid alkyl ester; (meth) acrylic acid phenyl, (meth) acrylic acid cyclohexyl, etc. (Meth) acrylic acid cyclic hydrocarbon ester; (poly) ethylene glycol mono (meth) acrylate, (meth) acrylic acid polyalkylene glycol ester such as polyethylene glycol mono (meth) acrylate having a polymerization degree of 2 to 10; (Meth) acrylamide; vinyl compounds such as styrene, α-methylstyrene, vinyl acetate, vinyl propionate, vinyl benzoate, vinyltoluene, acrylonitrile; crotonic acid esters; maleic acid Examples include diesters of unsaturated dibasic acids such as diesters and itaconic acid diesters. The ester moiety of the (meth) acrylic acid ester is preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. Preferred are methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and cyclohexyl (meth) acrylate. These may be used alone or in combination of two or more.

  The metal compound is not particularly limited, and examples thereof include metal oxides, hydroxides, chlorides, sulfides, basic carbonates, and acetic acid metal salts. Moreover, it does not specifically limit as said monobasic acid, For example, what was mentioned above can be mentioned.

  Although it does not specifically limit as number average molecular weight (GPC, polystyrene conversion) of the said acrylic resin (A1), It is preferable that it is 2000 or more and 100,000 or less, and it is more preferable that it is 3000 or more and 40000 or less. If it is less than 2000, the film-forming property of the coating film may be lowered, and if it exceeds 100,000, not only is the storage stability of the resulting coating deteriorated, but it is not suitable for practical use, and a large amount of dilution solvent is used at the time of painting. Therefore, it is not preferable in terms of public health and economy.

  The acrylic resin (A1) contains at least one group represented by the general formula (1). And the coating-material elution rate (hydrolysis rate of a coating film) to water can be controlled to a desired elution rate by adjusting the content rate of group represented by General formula (1). The content rate of group represented by the said General formula (1) can be adjusted mainly by adjusting the acid value of an acrylic resin (A1). The acid value of the acrylic resin (A1) is preferably 100 to 250 mgKOH / g. When the amount is less than 100 mgKOH / g, the amount of metal salt to be bonded to the side chain is small, and the antifouling property may be inferior. It tends to be difficult to obtain.

Acrylic resin (A2)
The acrylic resin (A2) is an acrylic resin having both a group represented by the general formula (1) and a group represented by the general formula (2) in the side chain as hydrolyzable groups. In the general formula (2), R ¹ , R ² and R ³ are the same or different and represent a hydrocarbon residue having 1 to 20 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, Isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl And a straight chain or branched alkyl group having 20 or less carbon atoms; a cyclic alkyl group such as a cyclohexyl group and a substituted cyclohexyl group; an aryl group and a substituted aryl group. Examples of the substituted aryl group include halogen, an aryl group substituted with an alkyl group having up to about 18 carbon atoms, an acyl group, a nitro group, an amino group, and the like. Of these, an isopropyl group or the like is preferable from the viewpoint of exhibiting a stable polishing rate (polishing rate) in the obtained coating film and maintaining the antifouling performance stably for a long period of time.

  The method for producing the acrylic resin (A2) is not particularly limited. For example, (I) a polymerizable unsaturated organic acid, a monomer component having a triorganosilyl group, and another copolymerizable unsaturated monomer are used. A method of reacting a resin obtained by polymerization with a monobasic acid and a metal compound, (II) reacting a polymerizable unsaturated organic acid with a metal compound and a monobasic acid, or polymerizable unsaturated Polymerizes a metal-containing unsaturated monomer obtained by reacting an organic acid with a metal salt of a monobasic acid, a monomer component having a triorganosilyl group, and another copolymerizable unsaturated monomer And the like.

  As the monomer component having the triorganosilyl group, the following general formula (3):

The triorganosilyl (meth) acrylate represented by these can be used preferably. In the triorganosilyl (meth) acrylate represented by the general formula (3), Z represents a hydrogen atom or a methyl group. R ⁴ , R ⁵ and R ⁶ are the same or different and represent a hydrocarbon residue having 1 to 20 carbon atoms, and examples thereof include the same hydrocarbon residues as R ¹ , R ² and R ³ above. Can do.

  Specific examples of the triorganosilyl (meth) acrylate represented by the general formula (3) are not particularly limited. For example, trimethylsilyl (meth) acrylate, triethylsilyl (meth) acrylate, tri-n-propylsilyl (meth) Acrylate, tri-i-propylsilyl (meth) acrylate, tri-n-butylsilyl (meth) acrylate, tri-i-butylsilyl (meth) acrylate, tri-s-butylsilyl (meth) acrylate, tri-n-amylsilyl (meta ) Acrylate, tri-n-hexylsilyl (meth) acrylate, tri-n-octylsilyl (meth) acrylate, tri-n-dodecylsilyl (meth) acrylate, triphenylsilyl (meth) acrylate, tri-p-methylphenyl Cyril (meth) a Relate, tribenzylsilyl (meth) acrylate, ethyldimethylsilyl (meth) acrylate, n-butyldimethylsilyl (meth) acrylate, di-i-propyl-n-butylsilyl (meth) acrylate, n-octyldi-n-butylsilyl ( (Meth) acrylate, di-i-propylstearylsilyl (meth) acrylate, dicyclohexylphenylsilyl (meth) acrylate, t-butyldiphenylsilyl (meth) acrylate, lauryl diphenylsilyl (meth) acrylate, t-butyl-m-nitrophenyl Examples include methylsilyl (meth) acrylate. Of these, tri-i-propylsilyl (meth) acrylate is preferable from the viewpoint of maintaining a stable polishing rate (polishing rate) for a long period of time. These triorganosilyl (meth) acrylates may be used alone or in combination of two or more.

  Examples of the polymerizable unsaturated organic acid, other copolymerizable unsaturated monomer, metal compound and monobasic acid include those described for the acrylic resin (A1). These polymerizable unsaturated organic acids and other copolymerizable unsaturated monomers may be used alone or in combination of two or more.

  The number average molecular weight (GPC, polystyrene conversion) of the acrylic resin (A2) is preferably 2000 or more and 100,000 or less, and more preferably 3000 or more and 40000 or less. If it is less than 2000, the film-forming property of the coating film may be lowered, and if it exceeds 100,000, not only is the storage stability of the resulting paint deteriorated, but it is not suitable for practical use, and a large amount of dilution solvent is used during painting. It is not preferable in terms of public health, economy, etc.

  The acrylic resin (A2) has at least one group represented by the general formula (1) and a side chain represented by the general formula (2). By controlling the total content of the groups represented by the general formula (1) and the general formula (2), the dissolution rate of the coating film into water (the hydrolysis rate of the coating film) is controlled to a desired dissolution rate. Can do. The total content of the groups represented by the general formula (1) and the general formula (2) can be adjusted mainly by adjusting the acid value of the acrylic resin (A2), and the acrylic resin (A2 ) Is preferably 30 to 200 mgKOH / g. When the amount is less than 30 mgKOH / g, the amount of metal salt to be bonded to the side chain decreases, and the antifouling property may be inferior. When the amount exceeds 200 mgKOH / g, the elution rate is too high, and long-term antifouling property is obtained. It tends to be difficult to obtain.

  When the acrylic resin (A1) and / or (A2) is used as the binder resin, other resins such as chlorinated paraffin, rosin, and hydrogenated rosin may be used in combination as necessary.

  In the antifouling coating composition, the content of the binder resin is preferably 20% by mass in the solid content and 70% by mass in the upper limit, and the lower limit is 25% by mass and the upper limit is 65% in the solid content contained in the antifouling coating composition. % Is more preferable. When the amount is less than 20% by mass, defects such as cracks and peeling tend to occur in the coating film. Moreover, when it exceeds 70 mass%, it exists in the tendency for an antifouling effect to be hard to be acquired. In addition, solid content contained in an antifouling paint composition means the sum total of components other than the solvent contained in an antifouling paint composition.

The antifouling agent contained in the antifouling agent antifouling coating composition is not particularly limited, and known ones can be used. Examples of the antifouling agent include inorganic compounds, organic compounds containing metals, and organic compounds not containing metals.

  Specific examples of the antifouling agent include, for example, zinc oxide; cuprous oxide; manganese ethylenebisdithiocarbamate; zinc dimethyldithiocarbamate; 2,4,5,6-tetrachloroisophthalonitrile; N, N-dimethyldichlorophenylurea Zinc ethylene bisdithiocarbamate; bisdimethyldithiocarbamoyl zinc ethylene bisdithiocarbamate; 3-iodo-2-propylbutylcarbamate; rhodan copper; 4,5, -dichloro-2-n-octyl-3 (2H) isothiazolone N- (fluorodichloromethylthio) phthalimide; N, N′-dimethyl-N′-phenyl- (N-fluorodichloromethylthio) sulfamide; tetramethylthiuram disulfide; 2,4,6-trichlorophenylmaleimide; , 5,6 Tetrachloro-4- (methylsulfonyl) pyridine; diiodomethylparatrisulfone; phenyl (bispyridyl) bismuth dichloride; 2- (4-thiazolyl) -benzimidazole; stearylamine-triphenylborane, laurylamine-triphenylborane, Triphenylborane amine complexes such as pyridine triphenylborane; 4-bromo-2- (4-chlorophenyl) -5- (trifluoromethyl) -1H-pyrrole-3-carbonitrile; zinc pyrithione (2-pyridinethiol-1- Oxide zinc salt); copper pyrithione (2-pyridinethiol-1-oxide copper salt); 1,1-dichloro-N-[(dimethylamino) sulfonyl] -1-fluoro-N-phenylmethanesulfenamide; 1-dichloro-N-[(dimethyl) Amino) sulfonyl] -1-fluoro-N- (4-methylphenyl) methanesulfenamide; 2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine; N ′-(3,4 -Dichlorophenyl) -N, N'-dimethylurea; and N'-tert-butyl-N-cyclopropyl-6- (methylthio) -1,3,5-triazine-2,4-diamine; . These antifouling agents may be used alone or in combination of two or more.

  The content of the antifouling agent is preferably a lower limit of 0.1% by mass and an upper limit of 80% by mass in the solid content of the antifouling coating composition. If it is less than 0.1% by mass, the antifouling effect cannot be obtained, and if it exceeds 80% by mass, defects such as cracks and peeling may occur in the coating film. The content of the antifouling agent is more preferably a lower limit of 1% by mass and an upper limit of 70% by mass.

The organic polymer particle antifouling coating composition may further contain organic polymer particles as necessary. By including the organic polymer particles, there is an advantage that a coating film having good low friction performance can be obtained. As the organic polymer particles, any of naturally-derived polymers or synthetic polymers can be used.

  The organic polymer particles preferably have a hydrophilic functional group and optionally have a crosslinked chain. Examples of the hydrophilic functional group include a hydroxyl group, an amino group, a carboxyl group, an amide group, and a polyoxyethylene group. By having a hydrophilic group, a high water absorption can be obtained, but the hydrophilicity becomes too high and the solubility in seawater may become too high. When the hydrophilicity becomes too high, the solubility in artificial seawater can be adjusted by introducing a hydrophobic group or crosslinking.

  Examples of naturally-derived polymers that can be used as organic polymer particles include chitin, chitosan, gum arabic, alginic acid, carrageenan, agar, chitansan gum, gellan gum, cellulose, xylose, starch, pullulan, pectin, roast bean gum, Examples thereof include polysaccharides such as dextran and curdlan; proteins such as keratin, collagen, silk, and γ-polyglutamic acid (hereinafter referred to as γ-PGA): nucleic acids and the like. In addition, hydrolyzing (for example, hydroalkylation), polyethylene glycolation, hydrophobization (for example, alkylation), grafting, and the like by performing hydrolysis, crosslinking reaction, etc. on these naturally derived polymers as necessary. These include derivative compounds such as three-dimensional semi-synthetic polymers.

  The naturally-derived polymer preferably has a cationic group. It is presumed that the elution rate into seawater can be controlled by having a cationic group. It does not specifically limit as said cationic group, For example, an amino group, an amide group, a pyridine group etc. can be mentioned. Natural polymers originally having a cationic group may be used, and in the case of a polymer having no cationic group, the polymer may be derivatized to introduce a cationic group.

  The naturally-derived polymer that can be used as the organic polymer particles is more preferably at least one organic polymer particle selected from the group consisting of chitin, chitosan, γ-PGA, pulverized silk, and derivatives thereof. preferable.

  The chitin is a polysaccharide, and this deacetylated product is chitosan. The deacetylation may be complete deacetylation or partial deacetylation. If necessary, it may be modified or crosslinked with polyoxyethylene, an aldehyde group-containing compound, or the like.

  The silk pulverized product is obtained by pulverizing silk, which is an eyebrow produced by silkworms, into particles. Among these, it is estimated that fibroin and sericin, which are naturally derived polymers contained as the main component of silk, have a suitable action. The silk pulverized product may be a product obtained by pulverizing natural silk as it is, or may be a product obtained by removing various components, hydrolyzing, purifying, classifying, and the like as necessary.

  The γ-PGA particles are obtained by drying and naturally granulating naturally-derived materials produced by fungi. The γ-PGA particles may be formed into particles by removing miscellaneous components, hydrolysis, purification, classification, and the like as necessary.

  The synthetic polymer that can be used as the organic polymer particles is not particularly limited, and examples thereof include acrylic resins, polyester resins, amine resins, and modified polyvinyl alcohol resins. These are preferably hydrophilic resins having a hydrophilic group such as a hydroxyl group, an amino group, and a carboxyl group, and have a partially crosslinked structure as necessary in order to control the solubility in seawater. It is preferable. A synthetic polymer having the above properties can be obtained by adjusting the hydrophilicity / hydrophobicity and the crosslinking ratio by a known method.

  As the synthetic polymer that can be used as the organic polymer particles, acrylic resin particles can be particularly preferably used. Examples of the acrylic resin particles include acrylic resin particles obtained by emulsion polymerization of a monomer composition comprising an acrylic monomer and optionally a crosslinkable monomer. .

  The acrylic resin particles can be obtained, for example, by emulsion polymerization of a monomer composition composed of an acrylic monomer and a crosslinkable monomer. The acrylic monomer is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) allylate, isobutyl (meth) acrylate, (meth) acrylic acid Alkyl esters of acrylic acid or methacrylic acid such as 2-ethylhexyl; hydroxyl-containing (meth) acrylic esters such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate; Examples include acrylonitrile, methacrylonitrile, dimethylaminoethyl (meth) acrylate, and the like.

  In the above emulsion polymerization, other ethylenically unsaturated monomers may be used. The ethylenically unsaturated monomer is not particularly limited, and examples thereof include styrene, α-methylstyrene, vinyl toluene, t-butyl styrene, vinyl acetate, and vinyl propionate. The acrylic monomer and the ethylenically unsaturated monomer may be used alone or in combination of two or more.

  The crosslinkable monomer is not particularly limited, and examples thereof include a monomer having two or more radically polymerizable ethylenically unsaturated bonds in the molecule.

  The monomer having two or more radically polymerizable ethylenically unsaturated bonds that can be used in the production of the acrylic resin particles is not particularly limited, and examples thereof include ethylene glycol diacrylate and ethylene glycol. Dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate 1,6-hexanediol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, penta Lithritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, glycerol dimethacrylate, glycerol diacrylate, glycerol allyloxy dimethacrylate, 1,1,1-trishydroxymethylethane diacrylate, 1,1,1-trishydroxy Methylethane triacrylate, 1,1,1-trishydroxymethylethane dimethacrylate, 1,1,1-trishydroxymethylethane trimethacrylate, 1,1,1-trishydroxymethylpropane diacrylate, 1,1,1- Trishydroxymethylpropane triacrylate, 1,1-trishydroxymethylpropane dimethacrylate, 1,1,1-trishydroxymethylpropane trime Polymerizable unsaturated monocarboxylic acid esters of polyhydric alcohols such as acrylate; polymerizable unsaturated alcohol esters of polybasic acids such as triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, diallyl terephthalate, diallyl phthalate; An aromatic compound substituted with two or more vinyl groups such as divinylbenzene can be exemplified.

In the monomer composition, the crosslinkable monomer is preferably 1% by mass or more based on the total amount of the monomer composition. If the mass ratio is out of the above range, desired acrylic resin particles may not be obtained. The mass ratio is more preferably 5 to 70% by mass.
It does not specifically limit as a polymerization method of the said monomer composition, It can carry out by conventionally well-known methods, such as emulsion polymerization and suspension polymerization.

  The organic polymer particles may be composite resin particles composed of two or more kinds of polymers. The composite resin particles composed of two or more kinds of polymers referred to here are particles obtained by granulating two or more of the above-mentioned various naturally-derived polymers and synthetic polymers. The means is not particularly limited, and examples thereof include arbitrary methods such as mixing, grafting, core-shell formation, INP (internet network intrusion structure), and surface treatment.

  The two or more kinds of polymers are not particularly limited, and examples thereof include the above-mentioned naturally-derived polymers and the above-described synthetic polymers. Among them, starch, pullulan, arabianori, κ-carrageenan, gelatin, cellulose, chitosan and derivatives thereof, polyvinyl alcohol, polyallylamine, polyvinylamine, poly (meth) acrylamide, poly (meth) acrylic acid and copolymers thereof The composite resin particles are preferably composed of at least one hydrophilic resin selected from the above and an acrylic resin. Such a combination is preferable in that hydrophilicity can be obtained while changing the physical properties of the particles as desired by the composition of the acrylic resin. As the hydrophilic resin, it is preferable to use at least one resin selected from chitosan, chitosan derivatives, and polyvinyl alcohol.

  The composite resin particles composed of the hydrophilic resin and the acrylic resin can be obtained, for example, by emulsion polymerization or suspension polymerization of the acrylic resin raw material monomer in the presence of the hydrophilic resin. As the emulsifier used at the time of polymerization, a known emulsifier can be used, but a reactive emulsifier is preferable from the viewpoint of water resistance and substrate adhesion.

  The reactive emulsifier is a surfactant having an α, β-ethylenically unsaturated bond, and is classified into four types of anionic, cationic, nonionic and zwitterionic types. Among the commercially available reactive emulsifiers, examples of anionic types include Eleminol JS series (manufactured by Sanyo Kasei Kogyo Co., Ltd.), Latemul S, ASK series (manufactured by Kao Corp.), Aqualon HS series (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) ), Adekaria soap SE, SR series (Asahi Denka Co., Ltd.), Antox MS-60 (Nippon Emulsifier Co., Ltd.) and the like. Moreover, as an example of a cation type, the Latemul K series (manufactured by Kao Corporation) is further used, and as an example of a nonion type, an aqualon series (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Adekaria soap NE, ER series (manufactured by Asahi Denka Co., Ltd.) ) And the like.

  The addition amount of the reactive emulsifier is preferably 15% by mass or less. When it exceeds 15 mass%, there exists a possibility that the water resistance of the coating film obtained from the coating material containing a composite resin particle may fall.

  In the synthesis of the composite resin particles, the mixing ratio of the monomer composition, which is a raw material for the acrylic resin, and the hydrophilic resin is preferably 40/60 to 97/3 in terms of mass ratio (solid content).

  The organic polymer particles have a solubility at 23 ° C. in artificial seawater specified in ASTM D1141-98 of 15 g / L or less, and the artificial seawater specified in ASTM D1141-98 has a water absorption of 0.01 mass. % Or more, and the particle size is preferably 0.05 to 100 μm. In addition, it was the artificial seawater prescribed | regulated to ASTMD1141-98 as a reference | standard of solubility and water absorption here.

  If the solubility of the organic polymer particles in artificial seawater as defined in ASTM D1141-98 at 23 ° C. exceeds 15 g / L, sufficient low friction performance may not be exhibited. That is, when the solubility of the organic polymer particles in seawater is too high, the organic polymer particles may easily dissolve in seawater and flow out of the coating film surface. The solubility is more preferably 12 g / L or less. In addition, the said solubility is the value which measured the solubility in the artificial seawater prepared according to ASTMD1141-98 after weighing organic polymer particle | grains under reduced pressure at room temperature.

  In addition, when the water absorption of the artificial seawater as defined in ASTM D1141-98 of the organic polymer particles is less than 0.01% by mass, a sufficient effect cannot be obtained due to low affinity with seawater, and friction There is a possibility that the reduction of the amount is suppressed. The water absorption is more preferably 0.1% by mass or more. Here, the amount of water absorption is precisely weighed 1 g of organic polymer particles dried under vacuum (under reduced pressure) at room temperature, added to 50 g of artificial seawater prepared according to ASTM D1141-98, and then stirred at 23 ° C. for 5 hours. Then, it is a value obtained by filtering off, washing the residue with water and weighing.

  Further, the organic polymer particles preferably have a particle size in the range of 0.05 μm as the lower limit and 100 μm as the upper limit. If the particle size is less than 0.05 μm, it may not be possible to obtain a sufficient friction reducing effect. Moreover, when the said particle size exceeds 100 micrometers, when it swells in seawater, there exists a possibility that the problem that a surface state may deteriorate may arise. The lower limit is more preferably 0.1 μm, and the upper limit is more preferably 40 μm. More preferably, it is 1-30 micrometers. In addition, the said particle size points out the weight average particle diameter calculated | required by light scattering or laser scattering.

  When the organic polymer particles are contained in the antifouling coating composition, the blending amount is preferably within the range of 0.01% by mass lower limit and 30% by mass upper limit with respect to the total solid content in the coating. When the content is less than 0.01% by mass, the desired effect due to the addition of the organic polymer particles cannot be obtained, which is not preferable. Even if the content exceeds 30% by mass, not only the friction reducing effect can be obtained in accordance with the blending amount, but also cracking of the coating film may occur due to particle swelling. The upper limit is more preferably 24% by mass.

Preparation of other components and antifouling coating composition The antifouling coating composition may contain, in addition to the above components, additives generally used in coating compositions. The additive is not particularly limited. For example, monobasic organic acids such as monobutyl phthalate and monooctyl succinate, plasticizers such as camphor and castor oil; water binders; anti-sagging agents; anti-coloring agents; A conventional additive such as an antifoaming agent, a coating film consumption adjusting agent, and various pigments.

  The antifouling coating composition comprises, for example, the above-mentioned antifouling agent, organic polymer particles as required, and additives such as a plasticizer, a coating film consumption adjusting agent, and a pigment as required. It can be prepared by adding and mixing using a mixer such as a ball mill, a pebble mill, a roll mill, or a sand grind mill. In the coating method of the present invention, the antifouling coating composition contains the organic solvent contained in the binder or additive, etc., and the antifouling coating composition itself contains a specific organic solvent at the time of painting. The amount of the organic solvent can be adjusted within the range satisfying the type and amount.

The coating method of the present invention is a coating method for coating an antifouling paint composition using an underwater structure as an object to be coated,
The antifouling coating composition contains 25 to 55% by volume of an organic solvent at the time of painting,
The organic solvent includes an organic solvent having a relative evaporation rate of 30 to 300 in a range of 80 to 100% by volume with respect to the total amount of the organic solvent,
The antifouling paint composition is applied to the object by airless spray coating, and the discharge pressure at the time of airless spray coating is 8 MPa or more.
This is a method for painting underwater structures.

In the coating method of the present invention, the object to be coated is a structure that is installed or used in a state of being immersed in water such as the sea or a river. In this specification, such a structure is referred to as an “underwater structure”. Specific examples of the underwater structure include ships, harbor facilities, oil fences, piping materials, bridges, buoys, industrial water facilities, submarine bases, and the like.

  These underwater structures are preferably coated with the anticorrosion coating composition before the antifouling coating composition is coated. As the anticorrosion coating composition, an anticorrosion coating composition generally used by those skilled in the art can be used.

Coating Method In the coating method of the present invention, the antifouling coating composition contains an organic solvent in the range of 25 to 55% by volume with respect to the volume of the antifouling coating composition at the time of coating. Furthermore, in this invention, the said organic solvent contains the organic solvent whose relative evaporation rate is 30-300 in the range of 80-100 volume% with respect to the total amount of an organic solvent. The antifouling coating composition is generally adjusted to a viscosity suitable for the coating method by adding an organic solvent during coating. In the coating method of the present invention, an airless spray coating is performed by including an organic solvent containing an organic solvent having a relative evaporation rate in a specific range in a range of 25 to 55% by volume with respect to the volume of the antifouling coating composition. It is possible to form a coating film excellent in smoothness with a film thickness of, for example, 100 to 300 μm without deteriorating the coating workability.

  In the coating method of the present invention, the object to be coated is an underwater structure. In the antifouling coating of this underwater structure, an extremely thick coating film is required in order to maintain the antifouling function for a long time. The antifouling coating film of the underwater structure needs an adequate amount to dissolve because the antifouling coating film itself dissolves gradually in water, thereby exhibiting an anti-fouling function for marine organisms. Because. On the other hand, when an extremely thick coating film having a film thickness of 100 to 300 μm is provided, there is a problem that coating defects such as sagging and smoothness are liable to occur. More specifically, the smoothness of the coating film can be improved by lowering the viscosity of the coating composition, but defects such as sagging are likely to occur. In addition, by increasing the viscosity of the coating composition, it is possible to prevent the occurrence of defects such as sagging, while the smoothness of the coating film tends to decrease.

  In addition, the method of repeating a coating process several times as a method of providing a thick coating film is also mentioned. However, by repeating the coating process, there is a problem that the coating process becomes complicated and the coating time becomes long. Further, when the coating process is repeated several times, when a coating film is further provided on the coating film, there is a problem that the coating film tends to sag and the adhesiveness is lowered.

  In the case of providing an extremely thick coating film having a film thickness of 100 to 300 μm, the present inventors include 25 to 55% by volume of an organic solvent at the time of coating, and the organic solvent has a relative evaporation rate. Using an organic solvent that is 30 to 300 in an amount of 80 to 100% by volume with respect to the total amount of the organic solvent, and this antifouling coating composition has a discharge pressure of 8 MPa or more during airless spray coating Under such conditions, it is possible to obtain a coating film with high smoothness even with such an extremely thick coating film by applying it to the object by airless spray coating, and good without sagging It has been found that it is possible to ensure proper painting workability. The reason why the coating film smoothness is improved and the coating workability is improved by the above coating conditions is that the antifouling coating composition contains an organic solvent having a relative evaporation rate of 30 to 300, and an airless spray having a high discharge pressure. In combination with a coating method, when an extremely thick coating film having a film thickness of 100 to 300 μm is provided, it is considered that high smoothness is achieved and good coating workability is achieved without occurrence of sagging. It is done.

  Antifouling paint compositions are generally diluted with an organic solvent prior to painting. In the present invention, the organic solvent is contained in a lower limit of 25% by volume and an upper limit of 55% by volume when the antifouling coating composition is applied. The upper limit of the volume% of the organic solvent is more preferably 45% by volume. When the amount of the organic solvent is less than 25% by volume, the viscosity of the coating becomes high and the atomization at the time of coating becomes insufficient, so that the smoothness may be deteriorated. On the other hand, when the amount of the organic solvent exceeds 55% by volume, the viscosity at the time of coating decreases and sagging tends to occur, which is not preferable as a method for coating an underwater structure.

  In the coating method of the present invention, the organic solvent having a relative evaporation rate of 30 to 300 is contained in the organic solvent contained in the antifouling coating composition in an amount of 80 to 100% by volume based on the total amount of the organic solvent. When the relative evaporation rate exceeds 300, the solvent volatilization at the time of coating is too early, so that the flow at the time of coating hardly occurs and the smoothness of the coating film is lowered. On the other hand, when the relative evaporation rate is less than 30, the solvent volatilization is too slow, so that the coating viscosity is lowered and the problem of sagging is likely to occur. The “relative evaporation rate” in the present specification refers to a numerical value relative to the evaporation rate of the organic solvent, where the evaporation rate of n-butyl acetate is 100. Here, the “evaporation rate of the organic solvent” means the time required for 90% by mass of the organic solvent to be measured to evaporate at a constant temperature (for example, 20 ° C.) and a constant pressure (for example, 760 Torr). To do.

  Specific examples of the organic solvent having a relative evaporation rate of 30 to 300 include, for example, xylene (relative evaporation rate: 68), toluene (relative evaporation rate: 195), ethylbenzene (relative evaporation rate: 84), n-heptane (relative Evaporation rate: 386), methanol (relative evaporation rate: 250), ethanol (relative evaporation rate: 190), 2-propanol (relative evaporation rate: 150), 1-propanol (relative evaporation rate: 90), 2-methyl- 1-propanol (relative evaporation rate: 70), 1-butanol (relative evaporation rate: 50), isobutyl acetate (relative evaporation rate: 152), n-butyl acetate (relative evaporation rate: 100), propylene glycol monomethyl ether acetate ( Relative evaporation rate: 34), methyl isobutyl ketone (relative evaporation rate: 165), Eth Glycol monomethyl ether (relative evaporation rate: 47), propylene glycol monomethyl ether (relative evaporation rate: 66), ethylene glycol monoethyl ether (relative evaporation rate: 32), and the like.

  As the organic solvent, it is more preferable to use an organic solvent having a relative evaporation rate of 60 to 200.

  Other organic solvents that can be used in combination with the organic solvent having a relative evaporation rate of 30 to 300 include, for example, cyclohexanone (relative evaporation rate: 25), methyl ethyl ketone (relative evaporation rate: 465), methyl acetate (relative evaporation). Speed: 1180), ethyl acetate (relative evaporation rate: 615), ethylene glycol monoethyl ether acetate (relative evaporation rate: 21), ethyl-3-ethoxypropionate (relative evaporation rate: 12), 3-methoxybutyl acetate (Relative evaporation rate: 14), 3-methyl-3-methoxybutyl acetate (relative evaporation rate: 10), 4-hydroxyl-4-methyl-2-pentanone (relative evaporation rate: 14), 3, 5, 5 -Trimethyl-2-cyclohexen-1-one (relative evaporation rate: 3), 2,6-dimethyl -4-heptanone (relative evaporation rate: 18), ethylene glycol mono-tertbutyl ether (relative evaporation rate: 19), ethylene glycol monobutyl ether (relative evaporation rate: 6), 3-methyl-3-methoxybutanol (relative evaporation rate) : 5). However, the amount of these other organic solvents is required to be 20% by volume or less based on the total amount of the organic solvent.

  In the coating method of the present invention, airless spray coating is used. With airless spray coating, the coating composition itself is pressurized with a pump, connected to an airless gun with a pressure hose, and sprayed into a spray from the nozzle in the form of a mist with a hydraulic pressure. Say the method. The principle of atomization of the paint composition by airless spray painting is not based on air blowing, but rather is similar to a water gun. By applying pressure to the paint composition itself, the paint ejected from the nozzle at high speed is air. It collides with and atomizes. Furthermore, the degree of atomization depends on the amount of paint discharged. The apparatus is composed of a paint composition pump, a pressure-resistant paint hose, an airless paint gun, and a spray nozzle tip for atomizing the paint attached to the tip of the gun. Examples of the pump include an air drive type, a hydraulic drive type, and an electric type, and an electric type may be used for outdoor painting. When an air drive type or a hydraulic drive type is used as a pump, a pump that is driven by compressed air or hydraulic pressure with a plunger-type pump and raises the hydraulic pressure several times to several tens of times with respect to the driving pressure can be used. . In the electric type, there is one in which a pump via hydraulic pressure is directly moved by a motor. Airless spray coating has the advantages of a large area that can be coated and good workability. Moreover, there is an advantage that a coating film having a large film thickness can be provided and a coating composition having a high viscosity can be applied.

In the coating method of the present invention, the distance from the gun tip to the surface to be coated at the time of painting by this coating machine is 100 to 1000 mm, particularly 300 to 900 mm, and the spray pattern width in the longitudinal direction is 400 to 800 mm, particularly 450 to 600 mm. Within the range of is preferable. The coating amount by the coating machine is suitably in the range of 150 to 1000 g / m ² , particularly 250 to 800 g / m ² based on the amount of the coating composition material. And in the coating method of this invention, the discharge pressure at the time of airless spray coating is 8 Mpa or more. Here, the “discharge pressure” refers to a pressure at which the coating composition is ejected in a discharge section (nozzle section) in which the coating composition is ejected in the form of a mist in airless spray coating. When the discharge pressure at the time of airless spray coating is 8 MPa or more, atomization at the time of coating proceeds and a smooth coating film is obtained. In addition, the organic solvent contained in the coating composition is likely to volatilize, the coating viscosity increases, and sagging hardly occurs even with a thick film. This discharge pressure is preferably 12 MPa or more. The upper limit of the discharge pressure is preferably 20 MPa or less in view of the actual work surface at the painting site.

  In the coating method of the present invention, the antifouling coating composition preferably has a viscosity in the range of 90 to 120 Ku at the time of coating. When the viscosity of the antifouling coating composition is in the above range, there is an advantage that better coating workability can be ensured in airless spray coating. The viscosity of the antifouling coating composition is determined by the Stormer viscometer method (Japanese Industrial Standard (JIS) K5600-2-2 General coating test method Part 2: Properties and stability of the paint Section 2: Viscosity ) Can be measured.

  In the present invention, air wrap spray coating may be used in the same manner as airless spray coating. The air lap spray coating is a coating that does not include air in the coating composition and uses air as a wrap around the nozzle. Thus, air wrap spray coating can be included as one aspect of airless spray coating in that air is not included in the coating composition.

  The following examples further illustrate the present invention, but the present invention is not limited thereto. In the examples, “parts” and “%” are based on mass unless otherwise specified.

Production Example 1 Preparation of acrylic resin varnish 1 To a four-necked flask equipped with a stirrer, a cooler, a temperature controller, a nitrogen inlet tube, and a dropping funnel, 64 parts by mass of xylene and 16 parts by mass of n-butanol were added and maintained at 115 ° C. It was. In this solution, ethyl acrylate 26.02 parts by mass, cyclohexyl methacrylate 15.00 parts by mass, methacrylic acid methoxypolyethylene glycol ester (NK ester M-90G, manufactured by Shin-Nakamura Chemical Co., Ltd.) 10.00 parts by mass, acrylic acid A monomer mixture consisting of 8.98 parts by mass, 40.00 parts by mass of triisopropylsilyl acrylate, and a mixture consisting of 2 parts by mass of t-butylperoxy-2-ethylhexanoate were added dropwise at a constant rate over 3 hours, and added dropwise. After completion, the mixture was kept warm for 30 minutes. Thereafter, a mixed liquid consisting of 16 parts by mass of xylene, 4 parts by mass of n-butanol and 0.2 parts by mass of t-butylperoxy-2-ethylhexanoate was dropped at a constant rate over 30 minutes. A resin varnish was obtained by incubating for 5 hours. Solid content in the obtained resin varnish was 49.6 mass%, and the viscosity was 6 poise. Moreover, the number average molecular weight (GPC, polystyrene conversion) of the resin in this resin varnish was 6000, and the acid value was 70 mgKOH / g.
Next, in the same reaction vessel, 100 parts by mass of the obtained resin varnish, 12.9 parts by mass of copper acetate, hydrogenated rosin (Hyper CH, acid value 160, manufactured by Arakawa Chemical Industries), 21.7 parts by mass, xylene The acrylic resin varnish 1 having a solid content of 60.2% by mass was obtained by adding 110 parts by mass and heating to 130 ° C. to remove acetic acid together with the solvent.

Production Example 2 Preparation of Acrylic Resin Varnish 2 A solvent was removed from the acrylic resin varnish 1 obtained from Production Example 1 above using an evaporator to obtain an acrylic resin varnish 2 having a solid content of 75.1% by mass.

Production Example 3 Preparation of acrylic resin varnish 3 To a four-necked flask equipped with a stirrer, a cooler, a temperature controller, a nitrogen inlet tube, and a dropping funnel, 64 parts by mass of xylene and 16 parts by mass of n-butanol were added and kept at 100 ° C. It was. In this solution, 58.3 parts by mass of ethyl acrylate, 15.0 parts by mass of cyclohexyl methacrylate, methoxypolyethylene glycol ester of methacrylic acid (NK ester M-90G, manufactured by Shin-Nakamura Chemical Co., Ltd.) 10.0 parts by mass, acrylic acid A monomer mixture consisting of 16.7 parts by mass and a mixture consisting of 2 parts by mass of t-butylperoxy-2-ethylhexanoate were added dropwise at a constant rate over 3 hours, and the temperature was kept for 30 minutes after completion of the addition. Thereafter, a mixed solution consisting of 16 parts by mass of xylene, 4 parts by mass of n-butanol and 0.2 parts by mass of t-butylperoxy-2-ethylhexanoate was added dropwise at a constant rate over 30 minutes, and 1 hour 30 after the completion of the addition. A resin varnish was obtained by incubating for a minute. Solid content in the obtained resin varnish was 49.8 mass%, and the viscosity was 4.4 poise. Further, the acid value of the resin in this resin varnish was 130. Next, in the same reaction vessel, 100 parts by mass of the obtained resin varnish, 25.4 parts by mass of zinc acetate, naphthenic acid (NA-165, acid Acrylic resin varnish 3 having a solid content of 60.0% by adding 39.2 parts by mass and 110 parts by mass of xylene and heating to 130 ° C. and removing acetic acid together with the solvent. Got.

Production Example 4 Preparation of Acrylic Resin Varnish 4 To the same reaction vessel as in Production Example 1 above, 50 parts by mass of xylol was added and kept at 90 ° C. In this solution, a monomer mixture consisting of 35.0 parts by weight of methyl methacrylate and 65.0 parts by weight of triisopropylsilyl acrylate and a mixed liquid consisting of 1 part by weight of t-butylperoxy-2-ethylhexanoate were mixed. The solution was dropped at a constant rate over time, and kept warm for 30 minutes after the dropping. Thereafter, a mixed solution consisting of 7 parts by mass of xylol and 0.2 parts by mass of t-butylperoxy-2-ethylhexanoate was added dropwise at a constant rate over 30 minutes, and the mixture was kept warm for 1.5 hours after the completion of the addition. Then, the acrylic resin varnish 4 was obtained by cooling to 60 degreeC and adding 10 mass parts of xylol. Solid content in the obtained acrylic resin varnish 4 was 60.0 mass%. Moreover, the number average molecular weight (GPC, polystyrene conversion) of the resin in the acrylic resin varnish 4 was 8000.

Production Example 5 Preparation of Organic Polymer Particles Chitin (manufactured by Dainichi Seika Co., Ltd .: trade name chitin P) was pulverized with a jet pulverizer to obtain organic polymer particles having a particle size of 4 μm.

Production Examples 6 to 17 Production of antifouling paint compositions (1) to (15) Acrylic resin varnishes 1 to 4 and organic polymer particles obtained in Production Examples 1 to 5 above, and others shown in Tables 1 and 2 below. The antifouling paint compositions (1) to (15) were produced by mixing with a high-speed disper using the above components. In addition, the detail of each component of following Table 1, 2 is as follows.

・ Cuprous oxide: “NC-301” manufactured by NC Tech.
・ Copper pyrithione: “Copper Omagine” manufactured by Arch Chemical Co., Ltd.
・ Zinc flower: “Zinc oxide 2 types” manufactured by Sakai Chemical Industry Co., Ltd.
・ Valent: “Toda Color KN-R” manufactured by Toda Kogyo Co., Ltd.
・ Chlorinated paraffin: “Toyoparax A50” manufactured by Tosoh Corporation
・ Wood Rosin: “WW Rosin” manufactured by Arakawa Chemical Industries, Ltd.
Sagging inhibitor: “Disparon A600-20X” manufactured by Enomoto Kasei Co., Ltd.

Xylene: relative evaporation rate 68
Methyl ethyl ketone: relative evaporation rate 465
Toluene: relative evaporation rate 195
Cyclohexanone: Relative evaporation rate 25
Ethylene glycol monobutyl ether: Relative evaporation rate 6

Examples 1-14 and Comparative Examples 1-6
Paint plate (plate size 300mm × 400mm, thickness 0.3mm, (JIS G3303 (SPTE)) was installed vertically. Airless gun (Asahi Asahi) AG-4 type, chip 60C11) manufactured by Sanac Co., Ltd. was attached.The antifouling paint composition shown in Tables 3 and 4 below was put in a tin can and sent by an airless pump (pump pressure (original pressure) 0.6 MPa). Then, the paint was applied at room temperature with the discharge pressure shown in Tables 3 and 4. After the painting was completed, the paint plate was removed from the paint booth, and the paint surface was kept vertical as at the time of painting. Thus, a coating film having a dry film thickness of 120 μm was obtained.

Measurement of coating film roughness On the coating film obtained in the examples and comparative examples, a screwr roughness meter (manufactured by Meteco) was placed on the coating plate, and the handle of the roughness meter was held, scanned, and linear The gauge value (μm) was measured.
In addition, the roughness of the coating film was evaluated according to the following criteria.
○: Roughness is 50 μm or less ×: Roughness exceeds 50 μm

Measuring method of sagging limit film thickness The coated plates used in Examples and Comparative Examples were installed vertically and taped at the lower end. The antifouling paint composition used in each of the examples and comparative examples was applied to the coated plate with the above examples except that the film thickness of the dried coating film was changed to provide a film thickness of about 10 to 20 μm. Painted in the same way. Here, the thickness of the dry film thickness was adjusted by the conditions of the reciprocating movement speed of coating and the number of coating passes, and a coated plate having a thickness of about 10 to 20 μm was prepared. After the coating was dried for 1 minute, the taping was peeled off. After drying the obtained coating film, the maximum length of the sagging to the non-painted portion where taping was performed was measured. Here, the case where a sagging of 3 mm or more occurred was regarded as “impossible”, and the minimum dry film thickness at which sagging of 3 mm or more occurred was defined as the sagging limit film thickness.
In addition, in the determination of the sagging limit film thickness, the evaluation was made according to the following criteria.
○: Sagging limit film thickness 100 to 150 μm
A: Sagging limit film thickness exceeds 150 μm

As shown in Tables 3 and 4, in all of the examples, the coating film was low in roughness and high in coating film smoothness, and the sagging limit film thickness was as high as 100 μm or more.
Comparative Examples 1 and 6 are experimental examples in which the amount of the organic solvent contained in the antifouling coating composition exceeds 55% by volume during coating. In this case, the smoothness of the coating film is good, but since the sagging limit film thickness is low, it is not suitable for painting an underwater structure.
Comparative Example 2 is an experimental example in which the amount of the organic solvent contained in the antifouling coating composition is less than 25% by volume at the time of painting. In this case, the sagging limit film thickness was high and good, but the smoothness of the coating film was low.
Comparative Examples 3 and 4 are experimental examples in which the volume% of the organic solvent having a relative evaporation rate of 30 to 300 in the organic solvent is less than 80 volume%. In these cases, it was not possible to achieve both the smoothness of the coating film and the sagging limit film thickness.
Comparative Example 5 is an experimental example in which the discharge pressure during airless spray coating is less than 8 MPa. In this case, both the smoothness of the coating film and the sagging limit film thickness were reduced.

  According to the coating method of the present invention, in airless spray coating, the organic solvent is contained in an amount of 25 to 55% by volume, and the organic solvent has a relative evaporation rate of 30 to 300 with respect to the total amount of the organic solvent. By applying an antifouling paint composition containing 80 to 100% by volume by airless spray coating with a discharge pressure of 8 MPa or more, high workability is achieved even in the coating to form a thick film, and smoothness High coating film can be formed. Therefore, this coating method is an extremely suitable coating method as a coating method for an antifouling coating film used in painting an underwater structure. The coating method of the present invention can form a coating film with higher smoothness without increasing new processes such as a polishing process, and can further achieve both smoothness of the coating film and coating workability. There is an advantage.

Claims (6)

A coating method for coating an antifouling paint composition with an underwater structure as a coating,
The antifouling coating composition contains 25 to 55% by volume of an organic solvent at the time of painting,
The organic solvent includes an organic solvent having a relative evaporation rate of 30 to 300 in a range of 80 to 100% by volume with respect to the total amount of the organic solvent,
The antifouling paint composition is applied to an object by airless spray coating, and the discharge pressure at the time of airless spray coating is 8 MPa or more.
How to paint underwater structures.   The method for coating an underwater structure according to claim 1, wherein the discharge pressure is 12 MPa or more.   The method for coating an underwater structure according to claim 1 or 2, wherein the antifouling coating composition contains 25 to 45% by volume of an organic solvent during coating.   The method for coating an underwater structure according to claim 1, wherein the antifouling coating composition has a viscosity of 90 to 120 KU. The antifouling coating composition contains a binder resin, an antifouling agent, an organic solvent,
The binder resin has the following general formula (1):

[In Formula (1), X is

K is 0 or 1, Y is a hydrocarbon, M is a divalent metal, and A represents an organic acid residue of a monobasic acid. ]
It is an acrylic resin having a group represented by
The method for coating an underwater structure according to claim 1. The acrylic resin has, in the side chain, the following general formula (2):

Wherein ^{(2), R 1, R} 2, R 3 are the same or different and each represents a hydrocarbon residue having 1 to 20 carbon atoms. ]
The coating method of the underwater structure of Claim 5 which has further group represented by these.