JP7311677B2 - Coating composition and coating film - Google Patents

Description

The present invention relates to coating compositions and coating films.

Fluorine-containing polyol paints have been known as resins for paints with excellent weather resistance, and are used, for example, as topcoats for structures, architectural exteriors, aircraft, windmills, plastics, and the like. Polyisocyanate compounds are used as curing agents for fluorine-containing polyols (see, for example, Patent Document 1).

In recent years, due to the growing interest in protecting the global environment, there has been a great deal of technological development aimed at reducing the viscosity of polyisocyanates used as curing agents. This is because the amount of the organic solvent used in the coating composition can be reduced by reducing the viscosity of the polyisocyanate (see, for example, Patent Documents 2 and 3).
Techniques for reducing the viscosity of the curing agent include techniques using a low-viscosity triisocyanate compound alone (for example, see Patent Documents 4 to 6), or techniques for isocyanurating a portion of these triisocyanate compounds (for example, , see Patent Document 7). Satisfactory low viscosity and a certain degree of drying properties have been obtained using these techniques.

JP 2011-256257 A Japanese Patent No. 3055197 JP-A-05-222007 Japanese Patent Publication No. 63-015264 JP-A-53-135931 JP-A-60-044561 JP-A-10-087782

When attempting to simultaneously improve the weather resistance of paint resins and lower the viscosity of isocyanates, in the polyisocyanates disclosed in Patent Documents 2 and 3, bifunctional polyisocyanates exist in the structure and crosslink density It was difficult to achieve the above problems because the Moreover, Patent Documents 4 to 6 do not mention a coating composition containing a triisocyanate compound and a fluorine-containing polyol.

The present invention has been made in view of the above circumstances, and provides a coating composition that is excellent in gloss, hardness, weather resistance and water vapor barrier properties when formed into a coating film, and a coating obtained by curing the coating composition. Provide the membrane.

That is, the present invention includes the following aspects.
The coating composition according to the first aspect of the present invention is an isocyanate component containing at least one of a triisocyanate represented by the following general formula (I) and a polyisocyanate compound derived from the triisocyanate. and a fluorine-containing polyol having a hydroxyl value of 10 mgKOH/g or more and 200 mgKOH/g or less.

(In the general formula (I), a plurality of Y ¹ are each independently a single bond, or 2 having 1 to 20 carbon atoms which may contain one or more selected from the group consisting of an ester group and an ether group. Each Y ¹ may be the same or different, and each R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. )

In the coating composition according to the first aspect, the isocyanate component may have a viscosity of 5 mPa·s or more and 100 mPa·s or less at 25 degrees.
In the coating composition according to the first aspect, the isocyanate group content of the isocyanate component may be 40% by mass or more.

The coating film according to the second aspect of the present invention is obtained by curing the coating composition according to the first aspect.

According to the coating composition of the above aspect, a coating film having excellent gloss, hardness, weather resistance and water vapor barrier properties can be obtained. The coating film of the above aspect is excellent in gloss, hardness, weather resistance and water vapor barrier properties.

EMBODIMENT OF THE INVENTION Hereinafter, the form (only henceforth "this embodiment") for implementing this invention is demonstrated in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the gist thereof.

As used herein, "polyisocyanate" refers to a polymer in which a plurality of monomers having one or more isocyanate groups (--NCO) are bonded.
As used herein, "polyol" refers to a compound having two or more hydroxy groups (--OH).

≪Paint composition≫
The coating composition of the present embodiment contains an isocyanate component as a curing agent and a resin component containing a fluorine component as a main agent.
The isocyanate component is at least one of a triisocyanate represented by the following general formula (I) (hereinafter sometimes referred to as "triisocyanate (I)") and a polyisocyanate compound derived from the triisocyanate containing compounds of
Moreover, the resin component containing a fluorine component includes a fluorine-containing polyol having a hydroxyl value of 10 mgKOH/g or more and 200 mgKOH/g or less.

(In the general formula (I), a plurality of Y ¹ are each independently a single bond, or 2 having 1 to 20 carbon atoms which may contain one or more selected from the group consisting of an ester group and an ether group. Each Y ¹ may be the same or different, and each R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. )

The coating composition of the present embodiment has the above-described configuration, so that a coating film having excellent gloss, hardness, weather resistance, and water vapor barrier properties can be obtained.
Next, each constituent component of the coating composition of the present embodiment will be described in detail below.

<Isocyanate component>
The isocyanate component includes at least one of triisocyanate (I) and a polyisocyanate compound derived from the triisocyanate (I) (hereinafter sometimes simply referred to as "polyisocyanate compound"). .
The isocyanate component may contain either the triisocyanate (I) or the polyisocyanate compound alone, or may contain both the triisocyanate (I) and the polyisocyanate compound.
The isocyanate component may contain one type of triisocyanate (I) or polyisocyanate compound alone, or may contain two or more types of triisocyanate (I) or polyisocyanate compounds in combination.

[Triisocyanate (I)]
Triisocyanate (I) is a compound represented by the following general formula (I).

( ^Y1 )
In the general formula (I), a plurality of Y ¹ are each independently a single bond, or a divalent having 1 to 20 carbon atoms which may contain one or more selected from the group consisting of an ester group and an ether group. is a hydrocarbon group of A plurality of Y ¹ may be the same or different.

The divalent hydrocarbon group having 1 to 20 carbon atoms and not containing an ester group or an ether group in Y ¹ may be an aliphatic group or an aromatic group. The aliphatic group may be linear, branched or cyclic.
Examples of the linear or branched aliphatic group include an alkanediyl group (alkylene group) and an alkylidene group.
Examples of the cyclic aliphatic group include a cycloalkylene group.
Examples of the aromatic group include an arylene group such as a phenylene group.
Among them, an alkylene group is preferable as the divalent hydrocarbon group having 1 to 20 carbon atoms.
Examples of the alkylene group include a methylene group, a dimethylene group, a trimethylene group, a tetramethylene group, an octamethylene group and the like.
Among them, a tetramethylene group is preferable as the alkylene group.

Examples of the divalent hydrocarbon group having 1 to 20 carbon atoms and containing one or more selected from the group consisting of an ester group and an ether group for Y ¹ include groups represented by the following general formula (II) ( hereinafter sometimes referred to as “group (II)”).
—(CH ₂ ) _n1 —X—(CH ₂ ) _n2 — (II)

In the group (II), the bond of —(CH ₂ ) _n1 — opposite to X is bonded to C in the above general formula (I), and the bond of —(CH ₂ ) _n2 — opposite to X is bound to the NCO in the general formula (I). Also, n1 and n2 are integers satisfying 1≦n1+n2≦20. That is, it is preferable that both n1 and n2 are not 0, and n2, which is the side bonded to the NCO, is 1 or more.
Among them, n1 and n2 are each independently preferably an integer of 0 or more and 20 or less, more preferably an integer of 0 or more and 4 or less, and still more preferably an integer of 0 or more and 2 or less.
As a combination of n1 and n2, for example, a combination of n1=0 and n2=2 and a combination of n1=2 and n2=2 are preferable.
Also, in group (II), X is preferably an ester group.

In addition, when at least one of the plurality of Y ¹ has one or more of the group consisting of an aliphatic group and an aromatic group, the isocyanate component can be made to have a lower viscosity, and the isocyanate component can be used to cure the coating composition. The weather resistance of the coating film produced by using it as an agent can be improved.
Moreover, when at least one of the plurality of Y ¹ has an ester group or an ether group, the heat resistance of the isocyanate component can be further improved.
Moreover, when at least one of the plurality of ^Y1 's has an ester group, the heat resistance of the isocyanate component can be further improved.
Moreover, when at least one of the plurality of ^Y1 's has an ether group, the hydrolysis resistance of the isocyanate component can be further improved.

( ^R1 )
R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. The hydrocarbon group for R ¹ is not particularly limited and includes an alkyl group, an alkenyl group, an alkynyl group and the like. Among them, R ¹ is preferably a hydrogen atom.

Specific examples of preferred triisocyanates (I) include, for example, 4-isocyanatomethyl-1,8-octamethylene diisocyanate (hereinafter referred to as "NTI") disclosed in Japanese Patent Publication No. 63-015264 (Patent Document 4). molecular weight 251), 1,3,6-hexamethylene triisocyanate disclosed in JP-A-57-198760 (Reference 1) (hereinafter sometimes referred to as "HTI", molecular weight 209), bis(2-isocyanatoethyl) 2-isocyanatoglutarate (hereinafter sometimes referred to as "GTI", molecular weight 311) disclosed in Japanese Patent Publication No. 4-001033 (reference document 2), Examples thereof include lysine triisocyanate (hereinafter sometimes referred to as "LTI", molecular weight 267) disclosed in JP-A-53-135931 (Patent Document 5). These triisocyanates may be used individually by 1 type, and may be used in combination of 2 or more type.
Among them, NTI, GTI or LTI is preferred, and NTI or LTI is more preferred, from the viewpoint of further improving the reactivity of isocyanate groups.

[Method for producing triisocyanate (I)]
Triisocyanate (I) can be obtained by isocyanating amines such as amino acid derivatives, ether amines and alkyltriamines. Examples of amino acid derivatives that can be used include 2,5-diaminovaleric acid, 2,6-diaminohexanoic acid, aspartic acid, and glutamic acid. Since these amino acids are diamine monocarboxylic acids or monoamine dicarboxylic acids, the carboxyl groups are esterified with alkanolamines such as ethanolamine. As a result, the obtained triamine having an ester group can be converted to a triisocyanate having an ester group by phosgenation or the like.

Examples of ether amines include polyoxyalkylene triamines such as "D403" (trade name) available from Mitsui Chemicals Fine Co., Ltd. This is a triamine and can be made into a triisocyanate containing an ether group by phosgenation of the amine.
Examples of alkyltriamines include triisocyanatononane (4-aminomethyl-1,8-octanediamine) and the like. This is a triamine and can be made into a triisocyanate containing only hydrocarbons by phosgenation of the amine.

[Polyisocyanate compound]
The polyisocyanate compound is derived from the above triisocyanate (I). That is, the polyisocyanate compound is a reactant obtained by a polymerization reaction using the above triisocyanate (I) as a monomer (monomer).
Moreover, the polyisocyanate compound can have various functional groups such as an isocyanurate group, a biuret group, an allophanate group, an uretdione group, an iminodioxadiazinedione group, and a urethane group.

In general, an "isocyanurate group" is a functional group formed by reacting three isocyanate groups, and is represented by the following formula (III).

In general, a "biuret group" is a functional group formed by reacting three isocyanate groups with a biuretizing agent, and is represented by the following formula (IV).

Generally, an "allophanate group" is a functional group formed by reacting two isocyanate groups and one hydroxyl group, and is represented by the following formula (V).

In general, a "uretdione group" is a functional group formed by reacting two isocyanate groups, and is represented by the following formula (VI).

Generally, an "iminooxadiazinedione group" is a functional group formed by reacting three isocyanate groups, and is represented by the following formula (VII).

In general, a "urethane group" is a functional group formed by reacting one isocyanate group with one hydroxyl group, and is represented by the following formula (VIII).

[Method for producing polyisocyanate compound]
A polyisocyanate compound is obtained by polymerizing triisocyanate (I) using a known catalyst or by heating. After completion of the reaction, the unreacted triisocyanate (I) may be removed, or the unreacted triisocyanate (I) may be used as it is as the isocyanate component without removing it.

For example, when producing polyisocyanate compounds from volatile diisocyanates such as 1,6-hexamethylene diisocyanate, 1,5-pentane diisocyanate, toluene diisocyanate and isophorone diisocyanate, it is necessary to remove unreacted diisocyanate. At this time, the content of diisocyanate contained in the polyisocyanate compound derived from diisocyanate can be less than 2% by mass, preferably less than 1% by mass, relative to the total mass of the product.
On the other hand, when the polyisocyanate compound derived from triisocyanate (I) is used as it is without removing unreacted triisocyanate (I), unreacted triisocyanate (I) is an isocyanate group. Since there are three, the ability of the isocyanate component to crosslink with the polyol can be maintained without being lowered.
When removing the unreacted triisocyanate (I) from the resulting polyisocyanate compound, the polyisocyanate compound can be separated from the product by thin film distillation, solvent extraction, or the like.

[Other isocyanate compounds]
The isocyanate component may further contain other isocyanate compounds in addition to the triisocyanate (I) and the polyisocyanate compound.
Other isocyanate compounds include, for example, diisocyanates and polyisocyanate compounds derived from the diisocyanates.
Examples of diisocyanates include aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates.

Examples of aliphatic diisocyanates include tetramethylene diisocyanate (TMDI), pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexane-1,6-diisocyanate, and 2-methylpentane-1. , 5-diisocyanate (MPDI), lysine diisocyanate (LDI) and the like.

Examples of alicyclic diisocyanates include 1,3-bis(isocyanatomethyl)-cyclohexane (1,3-H6-XDI), 3(4)-isocyanatomethyl-1-methyl-cyclohexyl isocyanate (IMCI ), isophorone diisocyanate (IPDI), bis(isocyanatomethyl)-norbornane (NBDI), 4,4′-dicyclohexylmethane diisocyanate (H12MDI) and the like.

Examples of aromatic diisocyanates include 1,3-bis(isocyanatomethyl)-benzene, 1,3-bis(2-isocyanatopropyl-2)benzene and the like.
These diisocyanates may be used alone or in combination of two or more.

Among them, HDI or IPDI is preferable as the diisocyanate in terms of weather resistance and industrial availability.

Polyisocyanate compounds derived from diisocyanates are obtained by polymerizing the above diisocyanates using a catalyst or by heating. Polyisocyanate compounds derived from diisocyanates can have various functional groups such as isocyanurate groups, biuret groups, allophanate groups, uretdione groups, iminodioxadiazinedione groups and urethane groups in the molecule.
Among them, the polyisocyanate compound derived from diisocyanate preferably has an isocyanurate group from the viewpoint of weather resistance.

[Physical properties of isocyanate component]
Next, the physical properties of the isocyanate component will be described in detail below.

(Viscosity at 25°C)
The viscosity of the isocyanate component at 25° C. is not particularly limited, but is preferably 5 mPa·s or more and 2000 mPa·s or less, more preferably 5 mPa·s or more and 1800 mPa·s or less, and 5 mPa·s or more and 100 mPa·s or less. s or less, and more preferably 5 mPa·s or more and 80 mPa·s or less. By making the viscosity of the isocyanate component at 25°C equal to or higher than the above lower limit, curability tends to be more excellent. On the other hand, by setting the viscosity of the isocyanate component at 25° C. to the upper limit value or less, workability tends to be more excellent.
The viscosity can be measured using an E-type viscometer (manufactured by Tokimec).

(Isocyanate group content)
The lower limit of the isocyanate group content (hereinafter sometimes referred to as "NCO content") of the isocyanate component can be 30% by mass, and 35% by mass, in a state in which the solvent and diisocyanate are not substantially included. % is preferred, and 40 mass is more preferred.
On the other hand, the upper limit of the NCO content can be set to 60% by mass, preferably 57% by mass, more preferably 55% by mass, in a state that substantially no solvent or diisocyanate is included.
That is, the NCO content can be 30% by mass or more and 60% by mass or less, preferably 35% by mass or more and 57% by mass or less, and 40% by mass or more and 55% by mass, in a state that does not substantially contain a solvent or diisocyanate. % or less is more preferable.
When the NCO content is within the above range, an isocyanate component having more sufficient crosslinkability can be obtained.
In the present specification, the term "substantially containing no solvent or diisocyanate" means a state in which the content of the solvent or diisocyanate is less than 1% by mass with respect to the total mass of the isocyanate component. .

(Number of functional groups of isocyanate group)
The number of functional groups of the isocyanate group of the isocyanate component is preferably 2 or more and 12 or less. It has more sufficient crosslinkability because the number of functional groups of an isocyanate group is more than the said lower limit. On the other hand, when the number of functional groups of the isocyanate group is equal to or less than the above upper limit, the viscosity of the isocyanate component can be reduced to achieve a low viscosity.

[Other compounds]
The isocyanate component can contain other compounds. Other compounds include, for example, unsaturated bond-containing compounds, inert compounds, metal atoms, basic amino compounds, carbon dioxide, halogen atoms, and the like. These other compounds may be used singly or in combination of two or more.

The lower limit of the content of the other compounds in the isocyanate component is preferably 1.0 mass ppm with respect to the total mass of the compound having an isocyanate group such as the triisocyanate (I) or the polyisocyanate compound, and 3 0 mass ppm is more preferred, 5.0 mass ppm is more preferred, and 10 mass ppm is particularly preferred.
On the other hand, the upper limit of the content of the other compounds is preferably 1.0 × 10 ⁴ ppm by mass, more preferably 5.0 × 10 ³ ppm by mass, and 3.0 × 10 ³ mass ppm is more preferred, and 1.0×10 ³ mass ppm is particularly preferred.
That is, the content of the other compounds is preferably 1.0 mass ppm or more and 1.0 × 10 ⁴ mass ppm or less, and 3.0 mass ppm or more and 5.0 × 10 ³ mass ppm, relative to the mass of the isocyanate component. ppm or less is more preferable, 5.0 ppm by mass or more and 3.0×10 ³ mass ppm or less is still more preferable, and 10 mass ppm or more and 1.0×10 ³ mass ppm or less is particularly preferable.
When the content of the other compound is within the above range, the prevention of coloration during long-term storage and the long-term storage stability of the isocyanate component are further improved.

(Unsaturated bond-containing compound)
The unsaturated bond-containing compound is preferably a compound having a carbon-carbon unsaturated bond, a carbon-nitrogen unsaturated bond, or a carbon-oxygen unsaturated bond. Among them, from the viewpoint of compound stability, the unsaturated bond-containing compound is preferably a compound having a double bond, and a carbon-carbon double bond (C=C) or a carbon-oxygen double bond ( Compounds with C=O) are more preferred. Moreover, it is preferable that the carbon atoms constituting the compound are bonded to three or more atoms.
In general, the carbon-carbon double bond may be a carbon-carbon double bond that constitutes an aromatic ring, but the unsaturated bond possessed by the unsaturated bond-containing compound contained in the isocyanate component is It does not contain a carbon-carbon double bond that constitutes an aromatic ring.
Examples of compounds having a carbon-oxygen double bond include carbonic acid derivatives. Carbonic acid derivatives include, for example, urea compounds, carbonic acid esters, N-unsubstituted carbamic acid esters, and N-substituted carbamic acid esters.

(inert compound)
Inactive compounds are classified into compounds A to G below.
Hydrocarbon compounds are compound A and compound B, ether compounds and sulfide compounds are compounds C to E below, halogenated hydrocarbon compounds are compound F below, silicon-containing hydrocarbon compounds, silicon-containing ether compounds and silicon-containing sulfide compounds. are classified into compounds G below. Compounds A to G listed here contain no unsaturated bond other than the aromatic ring, and do not include compounds having the above-described unsaturated bond.
Compound A: an aliphatic hydrocarbon compound having a linear, branched or cyclic structure.
Compound B: an aromatic hydrocarbon compound optionally substituted with an aliphatic hydrocarbon group.
Compound C: A compound having an ether bond or a sulfide bond and an aliphatic saturated hydrocarbon group, in which the same or different aliphatic saturated hydrocarbon compounds are bonded via an ether bond or a sulfide bond.
Compound D: A compound having an ether bond or a sulfide bond and an aromatic hydrocarbon group, wherein the same or different aromatic hydrocarbon compounds are bonded via an ether bond or a sulfide bond.
Compound E: A compound having an ether bond or a sulfide bond, an aliphatic saturated hydrocarbon group, and an aromatic hydrocarbon group.
Compound F: A halide in which at least one hydrogen atom constituting an aliphatic saturated hydrocarbon compound or at least one hydrogen atom constituting an aromatic hydrocarbon compound is substituted with a halogen atom.
Compound G: A compound in which some or all of the carbon atoms of the compounds A to E are substituted with silicon atoms.

(metal atom)
The metal atom may exist as a metal ion, or may exist as a single metal atom. One type of metal atom may be included alone, or two or more types of metal atoms may be included in combination. The metal atom is preferably a metal atom capable of taking a valence of 2 or more and 4 or less, and more preferably iron, cobalt, nickel, zinc, tin, copper or titanium.

(Basic amino compound)
Basic amino compounds are derivatives of ammonia, with alkyl or aryl groups substituted for one hydrogen (primary), two substituted (secondary), and all three substituted. There is a compound (tertiary) that is Among them, the basic amino compound is preferably a secondary or tertiary amino compound, more preferably an aliphatic amine, an aromatic amine, a heterocyclic amine or a basic amino acid.

(carbon dioxide)
Carbon dioxide may be dissolved in the isocyanate component under normal pressure, or may be dissolved in a pressure vessel under pressure. Since the use of carbon dioxide containing water may cause hydrolysis of the isocyanate component, it is preferable to control the amount of water contained in carbon dioxide as necessary.

(halogen atom)
A halogen atom may be present as a halide ion or as a halide. One type of halogen atom may be included alone, or two or more types of halogen atoms may be included in combination. The halogen atom is not particularly limited, but is preferably chlorine or bromine, more preferably chloride ion, bromide ion, hydrolyzable chlorine or hydrolyzable bromine. Examples of hydrolyzed chlorine include carbamoyl chloride compounds in which hydrogen chloride is added to an isocyanate group. Examples of hydrolyzable bromine include carbamoyl bromide compounds in which hydrogen bromide is added to an isocyanate group.
From the viewpoint of preventing coloration, the content of halogen atoms in the isocyanate component is preferably 1.0×10 ² mass ppm or less with respect to the total mass of the composition.

<Resin component>
The resin component contains a compound containing a fluorine component and having two or more active hydrogen-containing groups reactive with an isocyanate group in the molecule. Examples of compounds having two or more active hydrogen-containing groups in the molecule include polyols, polyamines, polythiols, and the like, including at least polyols. That is, the coating composition of the present embodiment contains at least a fluorine-containing polyol as a resin component (main agent).

[Fluorine-containing polyol]
As used herein, "fluorine-containing polyol" means a polyol containing fluorine in its molecule. Examples of fluorine-containing polyols include fluoroolefins, cyclovinyl ethers, and hydroxyalkyl vinyl ethers disclosed in JP-A-57-34107 (reference 3) and JP-A-61-275311 (reference 4). , copolymers such as monocarboxylic acid vinyl esters, and the like.
More specifically, the fluorine-containing polyols include, for example, Lumiflon LF100, LF200, LF400, LF600, LF800, FE4400, and FD1000 of Asahi Glass Co., Ltd., Zeffle GK500, GK510, and GK550 of Daikin Chemical Industries, GK570, GK580, Cefralcoat 703, 705 of Central Glass, Fluonate K-700, K-702, K-704, K-705, K-707, WZQ-660 of DIC mentioned. One type of these fluorine-containing polyols may be used alone, or two or more types may be used in combination.

[Hydroxyl value and acid value of polyol]
The lower limit of the hydroxyl value of the polyol is preferably 10 mgKOH/g, more preferably 20 mgKOH/g, even more preferably 30 mgKOH/g.
The upper limit of the hydroxyl value of the polyol is preferably 200 mgKOH/g, more preferably 180 mgKOH/g, even more preferably 160 mgKOH/g.
That is, the hydroxyl value of the polyol is preferably 10 mgKOH/g or more and 200 mgKOH/g or less, more preferably 20 mgKOH/g or more and 180 mgKOH/g or less, and even more preferably 30 mgKOH/g or more and 160 mgKOH/g or less.
When the hydroxyl value of the polyol is within the above range, the workability of the coating composition of the present embodiment, and the gloss, hardness, weather resistance and water vapor barrier properties of the coating film using the coating composition are improved. become a thing.
That is, the coating composition of the present embodiment contains the above isocyanate component and a fluorine-containing polyol having a hydroxyl value of 10 mgKOH/g or more and 200 mgKOH/g or less.
The acid value of the polyol is preferably 0 mgKOH/g or more and 30 mgKOH/g or less.
A hydroxyl value and an acid value can be measured according to JIS K1557.

[NCO/OH]
The molar ratio (NCO/OH) of the isocyanate groups of the isocyanate component to the hydroxyl groups of the polyol is preferably 0.2 or more and 5.0 or less, more preferably 0.4 or more and 3.0, and 0.5 or more and 2.0. More preferred are:
When the NCO/OH ratio is at least the above lower limit, a tougher coating film tends to be obtained. On the other hand, when the NCO/OH is equal to or less than the above upper limit, the smoothness of the coating film tends to be further improved.

[Other polyols]
Moreover, the coating composition of the present embodiment may contain other polyols in addition to the fluorine-containing polyols as the resin component (main agent). Examples of other polyols include polyester polyols, polyether polyols, acrylic polyols, polyolefin polyols, and the like.

(polyester polyol)
A polyester polyol can be obtained, for example, by condensation reaction of a dibasic acid alone or a mixture of two or more kinds and a polyhydric alcohol alone or a mixture of two or more kinds.
Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid.
Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerin, and pentaerythritol. , 2-methylolpropanediol, ethoxylated trimethylolpropane, and the like.

As a specific method for producing the polyester polyol, for example, the above components are mixed and heated at about 160° C. or higher and 220° C. or lower to carry out a condensation reaction.
Alternatively, for example, polycaprolactones obtained by ring-opening polymerization of lactones such as ε-caprolactone using a polyhydric alcohol can also be used as polyester polyols.
The polyester polyol obtained by the production method described above can be modified using an aromatic diisocyanate, an aliphatic diisocyanate, an alicyclic diisocyanate, a compound obtained therefrom, or the like. Above all, polyester polyols are preferably modified using aliphatic diisocyanates, alicyclic diisocyanates, and compounds obtained therefrom, from the viewpoint of the weather resistance and yellowing resistance of the resulting coating film.

When the coating composition of the present embodiment contains a solvent with a high water content, some carboxylic acids derived from dibasic acids in polyester polyols are left to remain, and neutralized with bases such as amines and ammonia. By doing so, the polyester polyol can be made into a water-soluble or water-dispersible resin.

(polyether polyol)
The polyether polyol can be obtained, for example, using any one of the following methods (1) to (3).
(1) A method of randomly or block-adding an alkylene oxide alone or a mixture to a polyhydric hydroxy compound alone or a mixture using a catalyst to obtain polyether polyols.
Examples of the catalyst include hydroxides (lithium, sodium, potassium, etc.), strongly basic catalysts (alcoholates, alkylamines, etc.), composite metal cyanide complexes (metal porphyrin, zinc hexacyanocobaltate complex, etc.), and the like. be done.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide.
(2) A method of reacting a polyamine compound with an alkylene oxide to obtain a polyether polyol.
Examples of the polyamine compound include ethylenediamines.
Examples of the alkylene oxide include those exemplified in (1).
(3) A method of obtaining so-called polymer polyols by polymerizing acrylamide or the like using the polyether polyols obtained in (1) or (2) as a medium.

Examples of the polyvalent hydroxy compound include those shown in (i) to (vi) below.
(i) diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol, etc.;
(ii) sugar alcohol compounds such as erythritol, D-threitol, L-arabinitol, ribitol, xylitol, sorbitol, mannitol, galactitol and rhamnitol;
(iii) monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, ribodesose;
(iv) disaccharides such as trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, melibiose;
(v) trisaccharides such as raffinose, gentianose, melezitose;
(vi) tetrasaccharides such as stachyose;

(acrylic polyol)
Acrylic polyol, for example, polymerizes only polymerizable monomers having one or more active hydrogens in one molecule, or polymerizable monomers having one or more active hydrogens in one molecule, and the polymerizable monomer It can be obtained by copolymerizing other copolymerizable monomers.

Examples of the polymerizable monomer having one or more active hydrogens in one molecule include the following (i) to (vi). These may be used alone or in combination of two or more.
(i) acrylic acid esters having active hydrogen such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and 2-hydroxybutyl acrylate;
(ii) Methacrylic acids having active hydrogen such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate esters;
(iii) (meth)acrylic acid esters having polyvalent active hydrogen, such as (meth)acrylic acid monoesters of triols such as glycerin and trimethylolpropane;
(iv) Monoethers of Polyether Polyols and (Meth)Acrylic Acid Esters Having Active Hydrogen Examples of the polyether polyols include polyethylene glycol, polypropylene glycol, and polybutylene glycol. ;
(v) adducts of glycidyl (meth)acrylate with monobasic acids (eg, acetic acid, propionic acid, p-tert-butylbenzoic acid, etc.);
(vi) an adduct obtained by ring-opening polymerization of a lactone to the active hydrogen of the (meth)acrylic acid ester having an active hydrogen; is mentioned.

Other monomers copolymerizable with the polymerizable monomer include, for example, the following (i) to (iv). These may be used alone or in combination of two or more.
(i) methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, methacrylic acid (meth)acrylic acid esters such as isobutyl, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, and glycidyl methacrylate;
(ii) acrylic acid, methacrylic acid, maleic acid, itaconic acid, etc.), unsaturated amides (unsaturated carboxylic acids such as acrylamide, N-methylol acrylamide, diacetone acrylamide;
(iii) vinyl monomers having a hydrolyzable silyl group such as vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ-(meth)acrylopropyltrimethoxysilane;
(iv) Other polymerizable monomers such as styrene, vinyl toluene, vinyl acetate, acrylonitrile, dibutyl fumarate.

As a specific method for producing an acrylic polyol, for example, the above monomers are solution-polymerized in the presence of a radical polymerization initiator such as a known peroxide or an azo compound, and diluted with an organic solvent or the like as necessary. Thus, an acrylic polyol can be obtained.

When the coating composition of the present embodiment contains a solvent with a large water content, it can be produced by a known method such as solution polymerization of the above monomers and conversion to a water layer or emulsion polymerization. In that case, water-solubility or water-dispersibility can be imparted to acrylic polyol by neutralizing acidic moieties such as carboxylic acid-containing monomers such as acrylic acid and methacrylic acid and sulfonic acid-containing monomers with amines or ammonia. can.

(polyolefin polyol)
Examples of polyolefin polyols include polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene having two or more hydroxyl groups, polyisoprene having two or more hydroxyl groups, and hydrogenated polyisoprene having two or more hydroxyl groups.

<Other additives>
In addition to the isocyanate component and the fluorine-containing polyol, the coating composition of the present embodiment may optionally contain a melamine-based curing agent such as a complete alkyl type, methylol type alkyl, imino group type alkyl. .

Moreover, the isocyanate component, the fluorine-containing polyol, and the coating composition of the present embodiment may all contain an organic solvent.
Although the organic solvent is not particularly limited, it preferably does not have a functional group that reacts with a hydroxyl group and an isocyanate group, and is sufficiently compatible with the isocyanate component. Examples of such organic solvents include, but are not limited to, ester compounds, ether compounds, ketone compounds, aromatic compounds, ethylene glycol dialkyl ether compounds, and polyethylene glycol dicarboxylate, which are generally used as paint solvents. compounds, hydrocarbon solvents, aromatic solvents and the like.

The isocyanate component, the fluorine-containing polyol, and the coating composition of the present embodiment are all, depending on the purpose and application, within a range that does not impair the desired effects of the present embodiment, a catalyst for accelerating curing, Various additives used in the art, such as pigments, leveling agents, antioxidants, UV absorbers, light stabilizers, plasticizers, surfactants, coating surface hydrophilic agents, etc., may be mixed and used. can.

[Catalyst for Accelerating Curing]
Examples of curing acceleration catalysts include, but are not limited to, metal salts, tertiary amines, and the like.
Examples of metal salts include dibutyltin dilaurate, tin 2-ethylhexanoate, zinc 2-ethylhexanoate, cobalt salts and the like.
Examples of tertiary amines include triethylamine, pyridine, methylpyridine, benzyldimethylamine, N,N-dimethylcyclohexylamine, N-methylpiperidine, pentamethyldiethylenetriamine, N,N'-endoethylenepiperazine, N,N' - dimethylpiperazine and the like.

[Pigment]
Examples of pigments include titanium oxide, carbon black, indigo, quinacridone, and pearl mica.

[Leveling agent]
Examples of leveling agents include, but are not limited to, silicones, aerosils, waxes, stearates, and polysiloxanes.

[Antioxidant, UV absorber and light stabilizer]
Antioxidants, ultraviolet absorbers and light stabilizers include, for example, aliphatic, aromatic or alkyl-substituted aromatic esters of phosphoric acid or phosphorous acid, hypophosphorous acid derivatives, phosphorus compounds, phenolic derivatives (especially hindered phenol compounds), sulfur-containing compounds, tin-based compounds, and the like. These may be contained singly or in combination of two or more.
Phosphorus compounds include, for example, phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonate, dialkylpentaerythritol diphosphite, dialkylbisphenol A diphosphite and the like.
Examples of sulfur-containing compounds include thioether compounds, dithioate compounds, mercaptobenzimidazole compounds, thiocarbanilide compounds, and thiodipropionates.
Examples of tin-based compounds include tin malate, dibutyltin monoxide, and the like.

[Plasticizer]
Examples of plasticizers include, but are not limited to, phthalates, phosphates, fatty acid esters, pyromellitic esters, epoxy plasticizers, polyether plasticizers, liquid rubbers, and non-aromatic paraffin oils. etc.
Examples of phthalates include dioctyl phthalate, dibutyl phthalate, diethyl phthalate, butylbenzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, diundecyl phthalate, and diisononyl phthalate.
Phosphate esters include, for example, tricresyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trimethylhexyl phosphate, tris-chloroethyl phosphate, tris-dichloropropyl phosphate and the like.
Examples of fatty acid esters include octyl trimellitate, isodecyl trimellitate, trimellitate esters, dipentaerythritol esters, dioctyl adipate, dimethyl adipate, di-2-ethylhexyl azelate, and dioctyl azelate. , dioctyl sebacate, di-2-ethylhexyl sebacate, methyl acetyl lysinocate and the like.
Examples of pyromellitic acid esters include pyromellitic acid octyl ester and the like.
Examples of epoxy plasticizers include epoxidized soybean oil, epoxidized linseed oil, and epoxidized fatty acid alkyl esters.
Examples of polyether plasticizers include adipate ether esters and polyethers.
Examples of liquid rubber include liquid NBR, liquid acrylic rubber, and liquid polybutadiene.

[Surfactant]
Examples of surfactants include known anionic surfactants, cationic surfactants, and amphoteric surfactants.

[Coating film surface hydrophilic agent]
Examples of coating film surface hydrophilic agents include silicate compounds, silica-based hydrophilic agents, fluorine-based hydrophilic agents, titanium oxide-based photocatalysts, and polymers containing quaternary ammonium salts.

<Method for producing paint composition>
The coating composition of this embodiment can be produced using the following method.
For example, first, the fluorine-containing polyol or its solvent-diluted product may optionally contain other resins, catalysts for accelerating curing, pigments, leveling agents, antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, The above-mentioned isocyanate component is added as a curing agent to the composition to which additives such as surfactants have been added. Then, if necessary, a solvent is further added to adjust the viscosity. Then, the coating composition can be obtained by stirring by hand or by using a stirring device such as a mazeler.

<Application>
The coating composition of this embodiment can be used as a coating for roll coating, curtain flow coating, spray coating, bell coating, electrostatic coating, and the like. Further, for example, it can be used as a primer or a top intermediate coating for materials such as metals (steel sheets, surface-treated steel sheets, etc.), plastics, wood, films, inorganic materials, and the like. It is also useful, for example, as a paint that imparts heat resistance and cosmetic properties (surface smoothness and sharpness) to precoated metals including rust-proof steel sheets, automobile paints, and the like. It is also useful, for example, as a urethane raw material for adhesives, adhesives, elastomers, foams, surface treatment agents and the like.

≪Paint film≫
The coating film of this embodiment is obtained by curing the coating composition according to the above embodiment.
By including the coating composition, the coating film of the present embodiment is excellent in gloss, hardness, weather resistance and water vapor barrier properties.

The coating film of the present embodiment is formed by applying the above coating composition on an object to be coated using a known coating method such as roll coating, curtain flow coating, spray coating, bell coating, and electrostatic coating. It can be manufactured by curing.
Examples of the object to be coated include the same materials as those exemplified in the above "<Application>".

Hereinafter, the present embodiment will be described more specifically with specific examples and comparative examples, but the present embodiment is not limited by the following examples and comparative examples as long as the gist thereof is not exceeded. do not have. The physical properties of the polyisocyanate compositions in Examples and Comparative Examples were measured as follows. "Parts" and "%" mean "mass parts" and "mass%" unless otherwise specified. Moreover, Examples 2 and 6 are reference examples.

<Method for measuring physical properties>
[Physical Property 1] Viscosity The viscosity of each isocyanate component was measured at 25° C. using an E-type viscometer (manufactured by Tokimec). A standard rotor (1°34′×R24) was used for the measurement. The number of revolutions is as follows.
100 rpm (when less than 128 mPa·s)
50 rpm (128 mPa·s or more and less than 256 mPa·s)
20 rpm (256 mPa·s or more and less than 640 mPa·s)
10 rpm (640 mPa·s or more and less than 1280 mPa·s)
5 rpm (1280 mPa·s or more and less than 2560 mPa·s)

[Physical Property 2] Isocyanate Group (NCO) Content The isocyanate group (NCO) content (% by mass) was obtained by neutralizing the isocyanate groups in the measurement sample with excess 2N amine and then performing back titration with 1N hydrochloric acid.

[Physical property 3] Conversion rate The term "conversion rate" as used herein means the mass ratio of the polyisocyanate compound produced by the polymerization reaction to the mass of the charged isocyanate monomer such as triisocyanate or diisocyanate. The conversion rate was calculated as follows. First, using the synthesized polyisocyanate compound as a sample, measurement was performed by gel permeation chromatography (GPC) under the following equipment and conditions, and the number average of polystyrene standards Molecular weights were obtained. In the GPC measurement, the number average molecular weight of the polyisocyanate compound was defined as the area ratio of peaks having a larger number average molecular weight than the unreacted isocyanate monomer such as triisocyanate or diisocyanate.

(Measurement condition)
Apparatus: "HLC-8120GPC" (trade name) manufactured by Tosoh Corporation
Column: "TSKgel Super H1000" (trade name) manufactured by Tosoh Corporation x 1
“TSKgel Super H2000” (trade name) x 1
"TSKgel SuperH3000" (trade name) x 1 Carrier: Tetrahydrofuran Detection method: Differential refractometer Sample concentration: 5 wt/vol%
Outflow: 0.6mL/min
Column temperature: 30°C

<Evaluation method>
[Evaluation 1] Gloss of coating film A coated plate was prepared in advance by coating an aluminum plate with white. After coating each coating composition obtained in Examples and Comparative Examples on the coated plate so that the dry film thickness is 40 μm, it is cured for 1 week under conditions of 23 ° C. and 50% RH to obtain a coating film. rice field. The glossiness of the prepared coating film was measured using a gloss meter (Gloss meter UGV-6P, manufactured by Suga Test Instruments Co., Ltd.) under the condition of a reflection angle of 60°. The evaluation criteria were as follows: ⊚ if the gloss value was 85% or more; ∘ if 80% or more and less than 85%;

[Evaluation 2] Hardness of coating film Each coating composition obtained in Examples and Comparative Examples was coated on a glass plate so as to have a dry film thickness of 40 µm, and then cured for 1 week at 23 ° C. and 50% RH. to obtain a coating film. The prepared coating film was measured with a Konig hardness tester (manufactured by BYK chemie) to evaluate the hardness of the coating film. Evaluation criteria were as follows: ⊚ if the number of measurements was 90 or more; ∘ if 70 or more and less than 90;

[Evaluation 3] Weather Resistance of Coating Film A coated plate was prepared in advance by white-coating an aluminum plate. After coating each coating composition obtained in Examples and Comparative Examples on the coated plate so that the dry film thickness is 40 μm, it is cured for 1 week under conditions of 23 ° C. and 50% RH to obtain a coating film. rice field. The prepared coating film was measured using a Sunshine Xenon Weather Meter (manufactured by Suga Test Instruments Co., Ltd.) under the following conditions to evaluate the weather resistance of the coating film.

(Measurement condition)
Operation cycle: Drying/spraying = 102 minutes/18 minutes cycle operation Drying black panel temperature: 63 degrees Humidity conditions: 50%
Layer temperature during spraying: 28°C
Light intensity: 180W/ ^m2

The evaluation criteria were as follows: ⊚ if the gloss retention after 8000 hours was 90% or more; ∘ if 80% or more; Δ if 50% or more;

[Evaluation 4] Water Vapor Barrier Property of Coating Film Each coating composition obtained in Examples and Comparative Examples was applied on an aluminum foil to a thickness of 25 μm, and then kept at 23° C. and 50% RH for 1 week. It was allowed to stand and cured to obtain a coating film. The prepared coating film was peeled off from the aluminum foil and used as a sample, and measured under condition B (temperature 40 degrees, humidity 90 RH%) based on JIS Z0208 (moisture-proof packaging material moisture permeability test method). evaluated. As evaluation criteria, if the water vapor permeation amount is less than 500 g/ ^mm2 , it is ◎, if it is 500 g/ ^mm2 or more and less than 750 g/mm2, it is ◯, if it is 750 g/ ^{mm2 or} more and less than 1000 g/ ^mm2 , it is △, and if it is 1000 g/mm2 ^or more, it is ×. and

<Synthesis of triisocyanate (I) and polyisocyanate compound>
[Synthesis Example 1] Synthesis of isocyanate component L-1 (NTI) 4-aminomethyl-1,8-octamethylenediamine (hereinafter simply 1060 g of "triamine") was dissolved in 1500 g of methanol, and 1800 mL of 35% concentrated hydrochloric acid was slowly added dropwise while cooling. After removing methanol and water under reduced pressure, the residue was concentrated and dried at 60° C. and 5 mmHg for 24 hours to obtain triamine hydrochloride as a white solid. 650 g of the resulting triamine hydrochloride was suspended in 5000 g of o-dichlorobenzene as a fine powder, and the temperature of the reaction solution was raised while stirring. When the temperature reached 100° C., phosgene was started to be blown at a rate of 200 g/hour, and the temperature was kept at 180° C., and phosgene was continuously blown for 12 hours. Dissolved phosgene and the solvent are distilled off under reduced pressure, and then vacuum distillation is performed to obtain colorless and transparent 4-isocyanatomethyl-1,8-octamethylene having a boiling point of 161° C./1.2 mmHg or more and 163° C./1.2 mmHg or less. 420 g of diisocyanate (hereinafter sometimes referred to as "NTI") was obtained. The resulting NTI had a viscosity of 8 mPa·s/25° C. and an NCO content of 50.0 mass %. The resulting NTI was designated as isocyanate component L-1.

[Synthesis Example 2] Synthesis of isocyanate component L-2 (LTI) 122.2 g of ethanolamine, 100 mL of o-dichlorobenzene, and 420 mL of toluene are placed in a four-necked flask equipped with a stirrer, a thermometer, and a gas inlet tube. was introduced and ice-cold hydrogen chloride gas was introduced to convert the ethanolamine to the hydrochloride. Next, 182.5 g of lysine hydrochloride was added, the reaction solution was heated to 80° C. to dissolve ethanolamine hydrochloride, and hydrogen chloride gas was introduced to obtain lysine dihydrochloride. Furthermore, hydrogen chloride gas was passed through at a rate of 20 mL/min or more and 30 mL/min or less, the reaction liquid was heated to 116° C., and this temperature was maintained until water stopped distilling out. The resulting reaction mixture was recrystallized in a mixture of methanol and ethanol to obtain 165 g of lysine β-aminoethyl ester trihydrochloride. 100 g of this lysine β-aminoethyl ester trihydrochloride was made into a fine powder and suspended in 1200 mL of o-dichlorobenzene, and the temperature of the reaction solution was raised while stirring. When the temperature reached 120°C, phosgene was started to be blown in at a rate of 0.4 mol/hour, held for 10 hours, and then heated to 150°C. The suspension mostly dissolved. After cooling, it is filtered, and the dissolved phosgene and solvent are distilled off under reduced pressure, followed by vacuum distillation to obtain a colorless and transparent lysine triisocyanate having a boiling point of 155° C./0.022 mmHg or more and 157° C./0.022 mmHg or less (hereinafter referred to as 80.4 g (sometimes referred to as "LTI") was obtained. The obtained LTI had a viscosity of 20 mPa·s/25° C. and an NCO content of 47.1% by mass. The obtained LTI was used as isocyanate component L-2.

[Synthesis Example 3] Synthesis of isocyanate component L-3 A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen blowing tube was set to a nitrogen atmosphere, and 100 g of NTI and 2-ethyl-1 were used as monomers. - 0.5 g of hexanol was charged and the temperature was maintained at 80°C for 2 hours. Thereafter, 0.01 g of an isocyanurate-forming catalyst, benzyltrimethylammonium capric acid, was added to carry out an isocyanurate-forming reaction. When the conversion reached 42%, 0.05 g of dibutyl phosphate was added to terminate the reaction. The reaction solution was further held at 120° C. for 15 minutes to obtain an isocyanate component L-3. The isocyanate component L-3 had a viscosity of 85 mPa·s/25° C. and an NCO content of 42.3 mass %.

[Synthesis Example 4] Synthesis of isocyanate component L-4 Into the same apparatus as in Synthesis Example 3, 100 g of NTI as monomers and 0.6 g of methanol were charged, and the temperature was maintained at 80°C for 2 hours. Thereafter, 0.1 g of an isocyanurate-forming catalyst, tetramethylammonium capric acid, was added to carry out an isocyanurate-forming reaction. When the conversion reached 48%, 0.03 g of dibutyl phosphate was added to terminate the reaction. The reaction solution was further held at 120° C. for 15 minutes to obtain an isocyanate component L-4. The isocyanate component L-4 had a viscosity of 80 mPa·s/25° C. and an NCO content of 42.0 mass %.

[Synthesis Example 5] Synthesis of isocyanate component L-5 Into the same apparatus as in Synthesis Example 3, 100 g of NTI, 23 g of trimethylphosphoric acid, 23 g of methyl cellosolve acetate, and 0.74 g of water were charged as monomers, and the temperature was set to 90°C. Hold for 1 hour. Thereafter, the temperature was raised to 160° C. and maintained for 2 hours to obtain an isocyanate component L-5. The obtained isocyanate component L-5 had a viscosity of 26 mPa·s/25° C. and an NCO content of 44.8 mass %.

[Synthesis Example 6] Synthesis of Isocyanate Component L-6 Into the same apparatus as in Synthesis Example 3, 100 g of LTI as monomers, 20 g of trimethylphosphoric acid, 20 g of methyl cellosolve acetate, and 0.56 g of water were charged, and the temperature was 90°C. Hold for 1 hour. Thereafter, the temperature was raised to 160° C. and maintained for 2 hours to obtain an isocyanate component L-6. The obtained isocyanate component L-6 had a viscosity of 33 mPa·s/25° C. and an NCO content of 43.4 mass %.

[Synthesis Example 7] Synthesis of Isocyanate Component Q-1 Into the same apparatus as in Synthesis Example 3, 100 g of HDI and 4 g of isobutanol were charged as monomers, and the temperature was maintained at 80° C. for 2 hours. Thereafter, 0.1 g of an isocyanurate-forming catalyst, tetramethylammonium capric acid, was added to carry out an isocyanurate-forming reaction. When the conversion reached 30%, 0.03 g of dibutyl phosphate was added to terminate the reaction. The reaction solution was further held at 120° C. for 15 minutes, and the resulting reaction solution was fed to a thin film evaporator to remove unreacted HDI to obtain isocyanate component Q-1. The obtained isocyanate component Q-1 had a viscosity of 300 mPa·s/25° C. and an NCO content of 20.0 mass %.

[Synthesis Example 8] Synthesis of Isocyanate Component Q-2 Into the same apparatus as in Synthesis Example 3, 100 g of HDI as monomers and 0.1 g of isobutanol were charged, and the temperature was kept at 80° C. for 2 hours. Thereafter, 0.4 g of an isocyanurate-forming catalyst, tetramethylammonium capric acid, was added to carry out an isocyanurate-forming reaction. When the conversion reached 45%, 0.3 g of dibutyl phosphate was added to terminate the reaction. The reaction solution was further held at 120° C. for 15 minutes. The obtained reaction liquid was fed to a thin film evaporator to remove unreacted HDI to obtain an isocyanate component Q-2. The obtained isocyanate component Q-2 had a viscosity of 2500 mPa·s/25° C. and an NCO content of 21.5 mass %.

[Example 1] Production of coating composition A-1 Fluorine-containing polyol (manufactured by Daikin Co., Ltd., trade name "Zeffle GK570", resin content concentration 65%, hydroxyl value 60 mgKOH / g) and the obtained in Synthesis Example 1 The isocyanate component L-1 was used and blended so that the molar ratio of isocyanate groups/hydroxyl groups was 1.0. Furthermore, the solid content was adjusted to 40% by mass with butyl acetate to obtain a coating composition A-1. Various evaluations were performed on the obtained coating composition using the methods described above. Table 1 shows the evaluation results.

[Examples 2 to 6] Production of coating compositions A-2 to A-6 Using the same method as in Example 1, except that the types of isocyanate components shown in Table 1 were used, coating compositions A-2 were prepared. ~A-6 were produced. Various evaluations were performed on the obtained coating composition using the methods described above. Table 1 shows the evaluation results.

[Comparative Example 1] Production of coating composition B-1 Same as Example 1 except that HDI (viscosity of 3 mPa s/25°C, NCO content of 50.0% by mass) was used as the isocyanate component. A coating composition B-1 was produced using the method of. Various evaluations were performed on the obtained coating composition using the methods described above. Table 1 shows the evaluation results.

[Comparative Examples 2 and 3] Production of coating compositions B-2 and B-3 Using the same method as in Example 1, except that the types of isocyanate components shown in Table 1 were used, coating compositions B-2 were prepared. ~B-3 were produced. Various evaluations were performed on the obtained coating composition using the methods described above. Table 1 shows the evaluation results.

From Table 1, coating compositions A-1 to A-6 (Examples In 1 to 6), the blended isocyanate component had a low viscosity of 8 mPa·s or more and 85 mPa·s or less, and all of the gloss, hardness, weather resistance and water vapor barrier properties when formed into coating films were good.
Further, the coating compositions A-1 and A-2 (Examples 1 and 2) containing an isocyanate component containing only triisocyanate (I) are a polyisocyanate compound derived from triisocyanate (I) and a triisocyanate ( The NCO content was particularly high at 47% by mass or more than the coating compositions A-3 to A-6 (Examples 3 to 6) containing an isocyanate component containing both I).
Further, the coating compositions A-1, A-2, A-5 and A-6 containing an isocyanate component having an NCO content of 43.4% by mass or more contained an isocyanate component having an NCO content of less than the above. Weather resistance was particularly better than that of the blended coating compositions A-3 and A-4.

The coating composition of this embodiment can be used as a coating for roll coating, curtain flow coating, spray coating, bell coating, electrostatic coating, and the like. The coating composition of the present embodiment can be used as a primer or intermediate coating for materials such as metals, plastics, wood, films and inorganic materials. The coating composition of the present embodiment is also useful as a coating for imparting heat resistance, cosmetic properties (surface smoothness, sharpness) and the like to precoated metals including rust-proof steel plates, automobile coatings, and the like. The coating composition of the present embodiment is also useful as a urethane raw material for adhesives, adhesives, elastomers, foams, surface treatment agents, and the like.

Claims (3)

an isocyanate component containing at least one of 4-isocyanatomethyl-1,8-octamethylene diisocyanate and a polyisocyanate compound derived therefrom;
a fluorine-containing polyol having a hydroxyl value of 10 mgKOH/g or more and 200 mgKOH/g or less;
A paint composition comprising: 2. The coating composition according to claim 1, which is used as a topcoat for structures, building exteriors, aircraft, windmills or plastics. A coating film obtained by curing the coating composition according to claim 1 or 2.