WO2022006703A1

WO2022006703A1 - Composition, coating formulation, and multilayer body

Info

Publication number: WO2022006703A1
Application number: PCT/CN2020/100413
Authority: WO
Inventors: Shizheng HOU; Naoto Yagi; Teruki Kiyohara; Chao Wang; Juyan HAN
Original assignee: Dic Corporation
Priority date: 2020-07-06
Filing date: 2020-07-06
Publication date: 2022-01-13

Abstract

A composition including an isocyanate compound and a block copolymer. The block copolymer has a number average molecular weight of 3000 to 20000. The block copolymer is an AB-type block copolymer including a hydrophilic segment A and a hydrophobic segment B. The hydrophilic segment A includes an end-capped polyoxyalkylene group. The hydrophobic segment B includes a copolymer of a hydrophobic monomer and a monomer having an active-hydrogen-containing group that is reactive with isocyanate. The block copolymer has a hydroxy value of 3 to 25 mg/gKOH.

Description

COMPOSITION, COATING FORMULATION, AND MULTILAYER BODY

[Technical Field]

The present invention relates to a composition including an isocyanate compound and a block copolymer that has a specific structure.

[Background Art]

In recent years, from the standpoint of environmental problems, work environments, and the like, an important issue to be addressed has been to reduce volatile organic solvents. In particular, in the coating industry, which uses large amounts of organic solvents, there is a strong demand for a shift to aqueous systems, as the VOC regulations or the like are enforced in various countries. In the art of coating formulations, room temperature curable coating formulations that are used in a very broad range of fields are two-component curable acrylic urethane coating formulations; however, since the two-component curable acrylic urethane coating formulations utilize a polyisocyanate, which reacts with water, a problem is presented in that the shift to aqueous systems is very difficult. In a case where the two-component curable acrylic urethane coating formulations are used as an aqueous system, the pot life after the coating formulations are prepared is very short compared with a case where the coating formulations are used as an organic solvent-based system, and, therefore, such aqueous systems have only been used in limited applications.

[Citation List]

[Patent Literature]

[PTL 1]

Japanese Patent No. 4258835

[Summary of Invention]

[Technical Problem]

An object of the present invention is to provide a composition that can form an aqueous coating formulation and enables the coating formulation to have a long pot life after the coating formulation is prepared, the composition being curable at room temperature. Other objects are to provide a coating formulation in which the composition is used and which is curable at room temperature, to provide a coating in which the coating formulation is used, and to provide a multilayer body including the coating.

[Solution to Problem]

The present inventors diligently performed studies and consequently found that the above-described objects can be achieved by providing a composition including an isocyanate compound and a block copolymer that has a specific structure.

Specifically, the present invention provides a composition including an isocyanate compound and a block copolymer. The block copolymer has a number average molecular weight of 3000 to 20000. The block copolymer is an AB-type block copolymer including a hydrophilic segment A and a hydrophobic segment B. The hydrophilic segment A includes an end-capped polyoxyalkylene group. The hydrophobic segment B includes a copolymer of a hydrophobic monomer and a monomer having an active-hydrogen-containing group that is reactive with isocyanate. The block copolymer has a hydroxy value of 3 to 25 mg/gKOH.

According to the present invention, the composition may further include an aqueous organic solvent and/or water.

According to the present invention, the composition may further include an active-hydrogen-containing compound.

Furthermore, the present invention provides a coating formulation that includes the composition, provides a coating that is a cured product of the coating formulation, and provides a multilayer body that includes the coating and a base member. [Advantageous Effects of Invention]

Compositions of the present invention can form aqueous coating formulations and enable the coating formulations to have a long pot life after the coating formulations are prepared, the compositions being curable at room temperature.

[Description of Embodiments]

The present invention provides a composition including an isocyanate compound and a block copolymer. The block copolymer has a number average molecular weight of 3000 to 20000. The block copolymer is an AB-type block copolymer including a hydrophilic segment A and a hydrophobic segment B. The hydrophilic segment A includes end-capped polyoxyalkylene groups. The hydrophobic segment B includes a copolymer of a hydrophobic monomer and a monomer having an active-hydrogen-containing group that is reactive with isocyanate. The block copolymer has a hydroxy value of 3 to 25 mg/gKOH.

[Isocyanate Compound]

The isocyanate compound of the present invention is not particularly limited provided that the compound has an isocyanate group. Preferably, the isocyanate compound is a polyisocyanate compound having two or more isocyanate groups. The isocyanate compound may be an isocyanate-group-containing monomer, an isocyanate-group-containing oligomer, or an isocyanate-group-containing polymer.

Examples of the polyisocyanate compound having two or more isocyanate groups include aromatic polyisocyanates, aliphatic or alicyclic polyisocyanates, and modified products thereof. Examples of the aromatic polyisocyanates include polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, phenylene diisocyanate, and tolylene diisocyanate. Examples of the aliphatic or alicyclic polyisocyanates include hexamethylene diisocyanate, lysine diisocyanate, 1, 3-bis (isocyanatomethyl) cyclohexane, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, dicyclohexylmethane diisocyanate, norbornene diisocyanate, dimer acid diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, toluene diisocyanate, and trimers of any of the foregoing isocyanates. Examples of the modified products of the polyisocyanates include trimethylolpropane adduct-type modified products, isocyanurate-type modified products, biuret-type modified products, and allophanate-type modified products.

Among polyisocyanate compounds, preferred polyisocyanate compounds are tri-or higher functional polyisocyanates, such as isocyanurate-type polyisocyanates, polyisocyanates having a biuret structure, polyisocyanates having a uretdione structure, polyisocyanates having an allophanate structure, and polyisocyanates that can be obtained by reacting a diisocyanate with tri-or higher hydric alcohols. These polyisocyanate compounds enable the production of a resin composition for an aqueous coating formulation that can form a coating having excellent weatherability and durability and are, therefore, preferred.

These isocyanate compounds may be used alone or in a combination of two or more.

[Block Copolymer]

The block copolymer of the present invention has a number average molecular weight of 3000 to 20000. The block copolymer is an AB-type block copolymer including a hydrophilic segment A and a hydrophobic segment B. The hydrophilic segment A includes end-capped polyoxyalkylene groups. The hydrophobic segment B includes a copolymer of a hydrophobic monomer and a monomer having an active-hydrogen-containing group that is reactive with isocyanate. The block copolymer has a hydroxy value of 3 to 25 mg/gKOH.

The block copolymer of the present invention includes the hydrophilic segment A and the hydrophobic segment B. Preferably, the block copolymer of the present invention is an AB-type vinyl-based block copolymer that can be obtained by polymerizing a vinyl-based monomer.

[Hydrophilic Segment A]

The hydrophilic segment A of the present invention includes end-capped polyoxyalkylene groups. The introduction of the end-capped polyoxyalkylene groups into the hydrophilic segment A can be accomplished by using, as a polymerization monomer, a vinyl-based monomer having an end-capped polyoxyalkylene group.

The polyoxyalkylene group to be introduced into the vinyl-based monomer having an end-capped polyoxyalkylene group may be a polyoxyalkylene group end-capped with any of a variety of groups, such as an alkoxy group, a substituted alkoxy group, an ester group, and a carbamate group. Examples of the polyoxyalkylene group include polyoxyethylene groups, polyoxypropylene groups, polyoxyethylene-polyoxypropylene random copolymers, polyoxyethylene-polyoxypropylene block copolymers, and polyoxyalkylene groups that can be obtained from ring opening polymerization of dioxolane. Among these polyoxyalkylene groups, preferred polyoxyalkylene groups are those containing oxyethylene groups as essential structural units.

Among the groups that may be used for the end capping, alkoxy groups or substituted alkoxy groups are preferable, and alkoxy groups are particularly preferable. Examples of the alkoxy groups include lower alkoxy groups, such as methoxy groups, ethoxy groups, and butoxy groups.

It is preferable that the polyoxyalkylene group have a number average molecular weight within a range of approximately 130 to approximately 10000, from the standpoint of the water dispersibility of the composition and the curability of a coating formulation that includes the composition; more preferably, the number average molecular weight is within a range of 150 to 8000, and particularly preferably within a range of 200 to 2000.

Examples of the vinyl-based monomer having an end-capped polyoxyalkylene group include the following monomers: methoxyethylene glycol acrylate, ethoxydiethylene glycol acrylate (Light Acrylate EC-A, manufactured by Kyoeisha Chemical Co., Ltd. ) , methoxytriethylene glycol acrylate (Light Acrylate MTG-A, manufactured by Kyoeisha Chemical Co., Ltd., Viscoat#MTG, manufactured by Osaka Organic Chemical Industry Ltd. ) , methoxydipropylene glycol acrylate (DPM-A, manufactured by Kyoeisha Chemical Co., Ltd. ) , polyethylene glycol monomethyl ether acrylate (MPE400A and MPE550A, manufactured by Osaka Organic Chemical Industry Ltd., AM-90G, AM-130G, and AM-230G, manufactured by Shin-Nakamura Chemical Co., Ltd., and Light Acrylate 130A, manufactured by Kyoeisha Chemical Co., Ltd. ) .

Furthermore, one or more other hydrophilic vinyl-based monomers may be used in combination with the vinyl-based monomer having an end-capped polyoxyalkylene group. Examples of hydrophilic vinyl-based monomers that may be used include hydrophilic vinyl monomers and hydrophilic (meth) acrylic monomers, such as N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylamide, and N-vinylpyrrolidone. Hydrophilic (meth) acrylic monomers are preferable.

In the hydrophilic segment A of the present invention, it is preferable that the vinyl-based monomer having an end-capped polyoxyalkylene group be present in an amount greater than or equal to 70 mol%of the total moles of the hydrophilic monomers included in the hydrophilic segment A. When the amount is within this range, the segment A is hydrophilic and serves as a dispersing agent without reacting with the isocyanate compound mentioned above, and, therefore, such an amount is preferable. More preferably, the amount is greater than or equal to 80 mol%, and, particularly preferably, greater than or equal to 90 mol%.

Furthermore, a hydrophobic vinyl-based monomer may be additionally used in an amount within a range that ensures the hydrophilicity of the hydrophilic segment A of the present invention. Specifically, it is sufficient that a hydrophilic vinyl-based monomer be present in an amount greater than or equal to 50 mol%of the total moles of the monomers included in the hydrophilic segment A. Preferably, the amount is greater than or equal to 60 mol%, more preferably greater than or equal to 70 mol%, and particularly preferably greater than or equal to 80 mol%.

[Hydrophobic Segment B]

The hydrophobic segment B of the present invention is a segment that can be obtained by copolymerizing a hydrophobic monomer and a monomer having an active-hydrogen-containing group that is reactive with isocyanate. As used herein, the term "hydrophobic monomer" generally refers to a monomer that has a hydrophobic group having 4 or more carbon atoms in total. In the hydrophobic segment B of the present invention, it is preferable that the hydrophobic monomer be present in a constitutional ratio of greater than or equal to 80 mass%.

Examples of the hydrophobic group having 4 or more carbon atoms in total include alkyl groups having 4 or more carbon atoms, such as n-butyl groups, isobutyl groups, tert-butyl groups, n-pentyl groups, n-hexyl groups, 2-ethylhexyl groups, n-octyl groups, n-dodecyl groups, and n-octadecyl groups; cycloalkyl groups having 4 or more carbon atoms, such as cyclobutyl groups, cyclopentyl groups, cyclohexyl groups, cyclooctyl groups, dicyclopentanyl groups, bornyl groups, and isobornyl groups; alkyl groups that are a substituted cycloalkyl group, such as cyclopentylmethyl groups, cyclohexylmethyl groups, 2-cyclopentylethyl groups, and 2-cyclohexylethyl groups; aryl groups or substituted aryl groups having 6 or more carbon atoms in total, such as phenyl groups, 4-methylphenyl groups, and 1-naphthyl groups; and aralkyl groups, such as benzyl groups and 2-phenylethyl groups.

The hydrophobic segment B is obtained by copolymerizing a monomer having an active-hydrogen-containing group that is reactive with isocyanate, and, therefore, the resulting hydrophobic segment B is reactive with isocyanate compounds. Examples of the active-hydrogen-containing group that is reactive with isocyanate include hydroxy groups, carboxy groups, amino groups, amide groups, and acetoacetyl groups. Hydroxy groups are particularly preferable. As a hydroxy-group-containing monomer, a hydroxy-group-containing vinyl-based monomer may be used. Examples of the hydroxy-group-containing vinyl-based monomer include hydroxylalkyl esters of various α, β-ethylenically unsaturated carboxylic acids and ε-caprolactone adducts thereof, such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, di-2-hydroxyethyl fumarate, mono-2-hydroxyethyl monobutyl fumarate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, and Placcel FM or Placcel FA (caprolactone adduct monomers manufactured by Daicel Corporation) . 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate are preferable.

In the block copolymer of the present invention, it is preferable that the hydrophilic segment A be present in an amount of 30 to 50 mass%of a total mass of the block copolymer. When the amount is within this range, excellent water dispersibility is achieved. More preferably, the amount is 35 to 50 mass%.

The block copolymer of the present invention has a number average molecular weight of 3000 to 20000. If the number average molecular weight is less than 3000, water dispersibility is degraded, and, therefore, such a number average molecular weight is not preferable. Furthermore, if the number average molecular weight is greater than 20000, the reaction of the isocyanate compound with a compound having an active-hydrogen-containing group, which will be described later, is inhibited, and, consequently, the curability of a coating formulation is degraded; therefore, such a number average molecular weight is not preferable. The number average molecular weight of the block copolymer of the present invention is preferably greater than or equal to 3000, more preferably greater than or equal to 5000, and particularly preferably greater than or equal to 8000. Furthermore, the number average molecular weight is preferably less than or equal to 20000, more preferably less than or equal to 18000, and particularly preferably less than or equal to 15000.

The block copolymer of the present invention has a hydroxy value of 3 to 25 mg/gKOH. When the hydroxy value is within this range, the block copolymer exhibits a certain affinity for the isocyanate group present in the isocyanate compound of the composition, and, therefore, the block copolymer contributes to the stability of the isocyanate compound in water. In particular, in a case where the composition is used to form urethane, the block copolymer effectively contributes to an improvement in pot life because the block copolymer stabilizes the composition in a state in which the isocyanate compound and a hydroxy-group-containing compound coexist.

The hydroxy value of the block copolymer of the present invention is preferably 5 to 20 mg/gKOH and particularly preferably 8 to 15 mg/gKOH.

A method for synthesizing the block copolymer of the present invention may be selected from methods known in the art. Among such methods, controlled radical polymerization is preferable. Specifically, reversible addition-fragmentation chain transfer (RAFT) polymerization, atom transfer radical polymerization (ATRP) , nitroxide-mediated polymerization (NMP) , organic tellurium-mediated radical polymerization (TERP) , reversible chain transfer catalyzed polymerization (RTCP) , and reversible complexation-mediated polymerization (RCMP) are more preferable, and RAFT polymerization is even more preferable.

The reversible addition-fragmentation chain transfer (RAFT) polymerization is a method that uses a thiocarbonyl-thio compound as a chain transfer agent. The thiocarbonyl-thio compound is not particularly limited provided that the compound contains a thiocarbonyl-thio group having a dithioester structure or a trithiocarbonate structure. Specific examples of the compound include bis (dodecylsulfanylthiocarbonyl) disulfide, 4- [ (2-carboxyethylsulfanylthiocarbonyl) sulfanyl] -4-cyanopen tanoic acid, 2- { [ (2-carboxyethyl) sulfanylthiocarbonyl] sulfanyl} propanoic acid, 4-cyano-4- [ (dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid, 2-cyano-2-propyl benzodithioate, bis [4- (allyloxycarbonyl) benzyl] trithiocarbonate, bis [4- (2, 3-dihydroxypropoxycarbonyl) benzyl] trithiocarbonate, bis {4- [ethyl- (2-acetyloxyethyl) carbamoyl] benzyl} trithiocarb onate, bis {4- [ethyl- (2-hydroxyethyl) carbamoyl] benzyl} trithiocarbon ate, bis [4- (2-hydroxyethoxycarbonyl) benzyl] trithiocarbonate, and bis (thiobenzoyl) disulfide. The chain transfer agent is used in combination with a radical generator. The combination ratio between the chain transfer agent and the radical generator is not particularly limited. The radical generator may be used in an amount of 0.01 to 10 moles per mole of the chain transfer agent. The radical generator may be a common radical generator, such as an organic peroxide or an azo compound. The radical generator is not particularly limited provided that radicals can be formed with the compound under the polymerization conditions. Specific examples of the radical generator include dialkyl peroxides, such as di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, and α, α'-bis (t-butyl peroxy-m-isopropyl) benzene; peroxyesters, such as t-butyl peroxybenzoate, t-butyl peroxyacetate, and 2, 5-dimethyl-2, 5-di (benzoylperoxy) hexane; ketone peroxides, such as cyclohexanone peroxide, 3, 3, 5-trimethylcyclohexanone peroxide, and methylcyclohexanone peroxide; peroxyketals, such as 2, 2-bis (4, 4-di-t-butylperoxycyclohexyl) propane, 1, 1-bis (t-butylperoxy) -3, 3, 5-trimethylcyclohexane, 1, 1-bis (t-butylperoxy) cyclohexane, and n-buty-4, 4-bis (t-butylperoxy) valerate; hydroperoxides, such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, and 2, 5-dimethylcyclohexane-2, 5-dihydroperoxide; diacyl peroxides, such as benzoyl peroxide, decanoyl peroxide, lauroyl peroxide, and 2, 4-dichlorobenzoyl peroxide; peroxy dicarbonates, such as bis (t-butylcyclohexyl) peroxydicarbonate; 2, 2'-azobis-butyronitriles, such as 2, 2'-azobisisobutyronitrile (AIBN) and 2, 2'-azobis (2-methylbutyronitrile) ; 2, 2'-azobis-valeronitriles, such as 2, 2'-azobis (4-methoxy-2, 4-dimethylvaleronitrile) and 2, 2'-azobis (2, 4-dimethylvaleronitrile) ; 2, 2'-azobis-propionitriles, such as 2, 2'-azobis (2-hydroxymethylpropionitrile) ; and 1, 1'-azobis-1-alkanenitriles, such as 1, 1'-azobis (cyclohexane-1-carbonitrile) .

The atom transfer radical polymerization (ATRP) is a method in which polymerization is performed by using an organic halide as a polymerization initiator and using a transition metal complex as a catalyst. The transition metal complex is formed of a metal selected from periodic table Group 8 to 11 elements and ligands. Examples of organic halides that may be used include monofunctional compounds such as ethyl 2-bromopropionate, butyl 2-bromopropionate, 2-bromopropionitrile, and 2-bromoisobutyronitrile; bifunctional compounds such as diethyl 2, 5-dibromoadipate, dimethyl 2, 6-dibromopimelate, and diethyl 2, 6-dibromopimelate; and polyfunctional compounds such as tris (bromomethyl) benzene. Examples of transition metal complexes that may be used include complexes of monovalent or zero-valent copper, divalent ruthenium, divalent iron, or divalent nickel. For example, in a case where an organic bromide or a sulfonyl bromide compound is used as a polymerization initiator, it is preferable to use, as a catalyst, a transition metal complex formed of a central metal and ligands, the central metal being copper present in copper bromide, preferably copper (I) bromide, the ligands being ligands of, for instance, bipyridine, N, N, N', N", N"-pentamethyldiethylenetriamine, 4, 4'-dinonyl-2, 2'-dipyridyl, or tris (2-dimethylamino) ethylamine.

The nitroxide-mediated polymerization (NMP) is a method that uses a nitroxide compound or an alkoxyamine compound derived from a nitroxide compound, as a regulator for controlling the polymerization. Examples of the nitroxide include 2, 2, 6, 6-substituted-1-piperidinyloxy radicals and 2, 2, 5, 5-substituted-1-pyrrolidinyloxy radicals. Examples of the substituent include alkyl groups having 1 to 4 carbon atoms. Examples of the nitroxide compound include 2, 2, 6, 6-tetramethyl-1-piperidinyl oxide, 2, 2, 6, 6-tetraethyl-1-piperidinyl oxide, 2, 2, 6, 6-tetramethyl-4-oxo-1-piperidinyl oxide, and 2, 2, 5, 5-tetramethyl-1-pyrrolidinyl oxide. Examples of the alkoxyamine compound derived from a nitroxide compound include N- (tert-butyl) -N- (1-diethylphosphono-2, 2-dimethylpropyl) -O- (2-carboxylprop-2-yl) hydroxylamine. The nitroxide compound is used in combination with a radical generator. The combination ratio between the nitroxide compound and the radical generator is not particularly limited. The radical generator may be used in an amount of 0.1 to 10 moles per mole of the nitroxide compound. The radical generator may be a radical generator similar to the one used in the RAFT polymerization.

The organic tellurium-mediated radical polymerization (TERP) is a method in which, in the presence of an organic tellurium compound, polymerization is accomplished through thermal breaking of the bond between tellurium atoms and carbon atoms, and degradative chain transfer that follows. Specific examples of the organic tellurium compound include (methyltellanyl-methyl) benzene, (1-methyltellanyl-ethyl) benzene, 1-chloro-4- (1-methyltellanyl-ethyl) benzene, 1-trifluoromethyl-4- (1-methyltellanyl-ethyl) benzene, 3, 5-bis-trifluoromethyl-1- (1-methyltellanyl-ethyl) benzene, 1, 2, 3, 4, 5-pentafluoro-6- (1-methyltellanyl-ethyl) benzene, 2-methyltellanyl-propionitrile, (2-methyltellanyl-propyl) benzene, methyl-2-methyltellanyl-2-methyl-propionate, ethyl-2-methyltellanyl-2-methyl-propionate, and 2-methyltellanyl-2-methyl-propionitrile.

The controlled radical polymerization can be carried out at a temperature of, for example, -100 to 250℃, preferably 0 to 200℃, more preferably room temperature to 200℃, and even more preferably 50 to 150℃, in the absence of a solvent (bulk polymerization) or in a solvent.

As the solvent, any solvent inert to the polymerization reaction may be used without particular limitation. Examples of the solvent include hydrocarbon-based solvents, such as benzene and toluene; ethereal solvents, such as diethyl ether and tetrahydrofuran; halogenated-hydrocarbon-based solvents, such as methylene chloride and chloroform; ketone-based solvents, such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; alcoholic solvents, such as methanol, ethanol, propanol, isopropanol, n-butanol, and t-butanol; nitrile-based solvents, such as acetonitrile, propionitrile, and benzonitrile; ester-based solvents, such as ethyl acetate and butyl acetate; carbonate-based solvents, such as ethylene carbonate and propylene carbonate; and amide-based solvents, such as N, N-dimethylformamide and N, N-dimethylacetamide.

Methods for producing the block copolymer by controlled radical polymerization include the following, for example: a method in which predetermined amounts of raw material compounds that form the structural units of the polymer blocks are added stepwise, a method in which one of the polymer blocks is synthesized in advance, and by using the synthesized polymer block as a high polymer polymerization initiator, the other polymer block is formed, and a method in which the polymer blocks are separately formed, and the formed polymer blocks are bonded to each other by a reaction. In a case where the stepwise addition of the raw material compounds is employed, it is desirable that when the degree of conversion of the firstly loaded raw material compound reaches 80 to 95%, the next raw material compound be loaded. The degree of conversion can be determined by gas chromatography, nuclear magnetic resonance spectroscopy, gravimetry, or the like, for example.

Furthermore, it is preferable that the block copolymer of the present invention have a narrow molecular weight distribution. Preferably, the molecular weight distribution is less than or equal to 2.0. In a case where controlled radical polymerization is employed for the synthesis, a molecular weight distribution of less than or equal to 1.5 can be achieved, and, therefore, controlled radical polymerization is particularly preferable.

[Composition]

The composition of the present invention includes the isocyanate compound and the block copolymer. The block copolymer of the present invention includes the hydrophilic segment A and the hydrophobic segment B. The hydrophobic segment B interacts with the isocyanate group present in the isocyanate compound, and, accordingly, the block copolymer can envelop the isocyanate compound. In addition, the hydrophilic segment has the end-capped polyoxyalkylene structure and, therefore, has hydrophilicity. Accordingly, unlike hydroxy groups or carboxy groups, the hydrophilic segment can exist while remaining unreactive with the isocyanate compound. Hence, the block copolymer contributes to the stability of the isocyanate compound in water.

In the composition of the present invention, the compounding ratio between the isocyanate compound and the block copolymer is not particularly limited provided that effects of the present invention can be produced. When the compounding ratio is 3: 1 to 20: 1 in terms of mass ratio, the stability of the composition in water is improved, and, therefore, such a compounding ratio is preferable. More preferably, the compounding ratio is 4: 1 to 15: 1, and particularly preferably 5: 1 to 10: 1.

The composition of the present invention may include an aqueous organic solvent inert to isocyanate groups. Examples of the aqueous organic solvent include tetrahydrofuran, 1, 2-dimethoxyethane, dioxane, acetone, methyl ethyl ketone, ethylene glycol monomethyl ether acetate, dimethylacetamide, dimethylformamide, ethylene glycol dimethyl ether, propylene glycol dimethylether, diethylene glycol dimethyl ether, dimethyl sulfone oxide, dioxirane, N-methylpyrrolidone, dimethyl imidazolidinone, and sulfolane. These may be used alone or in a combination of two or more.

In the composition of the present invention, an amount of addition of the aqueous organic solvent is not particularly limited and, preferably, may be 0 to 30 mass%relative to a total mass of the isocyanate compound and the block copolymer.

The composition of the present invention, which includes the isocyanate compound and the block copolymer described above, constitutes a water-dispersible isocyanate composition. This is achieved because the isocyanate groups can stably exist even in water by virtue of the block copolymer. Hence, the water-dispersible isocyanate composition is suitable for use as a material for a curable aqueous coating formulation that contains water as a principal component.

[Coating Formulation]

The composition of the present invention can be used as a curable coating formulation by being mixed with a compound having an active-hydrogen-containing group that will be described later. Since the composition is stable even when the composition includes water, the composition is particularly suitable for use in a curable aqueous coating formulation. This is because interaction between the isocyanate compound of the present invention and the block copolymer thereof enables the composition to exhibit excellent stability in water. In the coating formulation of the present invention, an amount of addition of water is not particularly limited and, preferably, may be 10 to 500 mass%relative to the total mass of the isocyanate compound and the block copolymer. Particularly preferably, the amount of addition is 30 to 300 mass%.

It is preferable that the composition of the present invention include a compound having an active-hydrogen-containing group, in addition to the one included in the block copolymer of the present invention. Including such a compound having an active-hydrogen-containing group is preferable because in this case, the compound reacts with the isocyanate compound of the present invention and, therefore, improves the curability of the coating formulation. It is sufficient that the compound have an active-hydrogen-containing group that can react with isocyanate groups, and the form and the type of the compound are not particularly limited. Representative examples of the active-hydrogen-containing group include hydroxy groups, carboxy groups, amino groups, amide groups, and acetoacetyl groups. In particular, hydroxy groups and carboxy groups are preferable.

The compound having an active-hydrogen-containing group may be a monomer, an oligomer, or a polymer. Preferably, the compound is a polymer having a molecular weight of 5000 to 100000. Representative examples thereof include vinyl-based polymers, such as vinyl acetate-based resins, styrene-butadiene-based resins, styrene-acrylonitrile-based resins, acrylic-based resins, fluoroolefin-based resins, silicone-modified vinyl-based resins, and polyvinylalcohols, and synthetic resins such as polyester-based resins, polyurethane-based resins, phenolic-based resins, melamine-based resins, epoxy-based resins, alkyd-based resins, polyamide-based resins, polyether-based resins, and silicone-based resins. Among these, vinyl-based polymers are preferable. In particular, in a case where a hydroxy-group-containing (meth) acrylic resin is used, a cured coating having a good appearance can be produced, and, therefore, a hydroxy-group-containing (meth) acrylic resin is preferable. Furthermore, it is preferable that a plurality of hydroxy groups be present per molecule; particularly preferred hydroxy-group-containing compounds are (meth) acrylic polyols.

[Other Components]

The composition of the present invention may include one or more other components, in addition to the components described above. Examples of the one or more other components include pigments, resins, fillers, curing agents, dispersing agents, neutralizing agents, adhesives, crosslinking agents, leveling agents, antioxidants, UV absorbers, and light stabilizers.

[Method for Producing Coating Formulation]

Methods for producing the coating formulation are not particularly limited. The coating formulation can be produced by mixing the composition of the present invention with a compound having an active-hydrogen-containing group. In a case where a curable aqueous coating formulation, which includes water, is to be produced, water may be first mixed with a compound having an active-hydrogen-containing group, and thereafter the composition of the present invention may be added to the mixture, and then mixing may be further performed; or, first, the composition may be dispersed in water, and thereafter a compound having an active-hydrogen-containing group may be mixed therewith.

[Coating]

A viscosity of the coating formulation of the present invention can be adjusted with an aqueous organic solvent and/or water to ensure a suitable application property.

The coating formulation of the present invention may be applied to a base member. Accordingly, a multilayer body including a coating formed from the coating formulation of the present invention can be produced. Methods for the application are not particularly limited, and any of the methods known in the art may be appropriately used. Examples of the methods include dipping methods, spray methods, spin coating methods, dip methods, roll coating methods, blade coating methods, doctor roll methods, doctor blade methods, curtain coating methods, slit coating methods, screen printing methods, and ink jet methods.

Materials for the base member are not particularly limited, and an appropriate material may be selected in accordance with the intended use. Examples of the material include wood, metals, plastics, paper, silicone, and modified silicone. The base member may be a base member obtained by j oining different materials together. A shape of the base member is not particularly limited, and the shape may be, for example, a planar plate shape, a sheet shape, or a three-dimensional shape having a curvature on the entire surface or a portion thereof. That is, any shape in accordance with the purpose may be employed. Furthermore, a hardness, a thickness, and the like of the base member are also not limited.

The composition of the present invention exhibits excellent storage stability even in an aqueous system and is, therefore, suitable for use in a curable aqueous coating formulation.

[EXAMPLES]

The present invention will now be described in detail with reference to examples. It should be noted that the scope of the present invention is not limited to the examples. Note that the units are on a mass basis unless otherwise specified.

Rate of polymerization: the rate of polymerization was calculated by determining the ratio of the residual monomer by using a gas chromatograph to which a DB-1 column, manufactured by Agilent Technologies Inc., was connected. The internal standard used was tetramine.

Number average molecular weight: the number average molecular weight was measured by using an HLC-8320, manufactured by Tosoh Corporation. The eluent used was THF. Four columns (TSKgel Super HZM-N, manufactured by Tosoh Corporation) were connected to the HLC-8320. The standard used was polystyrene.

Diameter of dispersed particles: diameters of the dispersed particles were measured by using an ELSZ-1000S, manufactured by Otsuka Electronics Co., Ltd.

(Synthesis Example 1: Synthesis of Block Copolymer (A-1) )

To a four-neck flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen inlet tube, 0.0821 g of 2, 2'-azobisisobutyronitrile, which was used as a polymerization initiator, 29.0 g of butyl acrylate, 1.0 g of 2-hydroxyethyl methacrylate, and 20.0 g of diethylene glycol dimethyl ether were added, and the contents were bubbled with nitrogen at a flow rate of 50 ml/min for 30 minutes. Next, 2.018 g of 4-cyano-4- [ (dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid, which was used as a RAFT agent, was added, and the contents were bubbled with nitrogen for 30 minutes. After the bubbling was finished, the contents were heated to 70℃ and stirred for 2.5 hours, under a nitrogen stream. Thus, a polymerization reaction was carried out, and, accordingly, a first block copolymer solution was obtained. To this solution, a mixed solution containing 20.0 g of methoxypolyethylene glycol #550 acrylate (AM-130G, manufactured by Shin-Nakamura Chemical Co., Ltd. ) in 20.0 g of diethylene glycol dimethyl ether was added. The mixed solution had been bubbled with nitrogen for 30 minutes in advance. The contents were stirred at 70℃ for 19 hours. Thus, a polymerization reaction was carried out, and, accordingly, an AB-type block copolymer (A-1) , which included a hydrophilic segment and a hydrophobic segment, was obtained. In the obtained block copolymer, the rate of polymerization of each of the monomers was as follows: 95%for the butyl acrylate; 100%for the 2-hydroxyethyl methacrylate; and 99%for AM-130G. The molecular weight was calculated by GPC, and it was found that the number average molecular weight was 9860, and the molecular weight distribution was 1.25.

(Synthesis Example 2: Synthesis of Block Copolymer (A-2) )

Polymerization was carried out as in Synthesis Example 1 except that the following changes were made to Synthesis Example 1: the amount of 2, 2'-azobisisobutyronitrile was changed to 0.1642 g, the amount of butyl acrylate to 28.5 g, the amount of 2-hydroxyethyl methacrylate to 1.5 g, and the amount of 4-cyano-4- [ (dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid to 4.037 g. Accordingly, a block copolymer (A-2) was obtained. In the obtained block copolymer, the rate of polymerization of each of the monomers was as follows: 94%for the butyl acrylate; 100%for the 2-hydroxyethyl methacrylate; and 96%for AM-130G. The molecular weight was calculated by GPC, and it was found that the number average molecular weight was 5789, and the molecular weight distribution was 1.15.

(Synthesis Example 3: Synthesis of Block Copolymer (A-3) )

Polymerization was carried out as in Synthesis Example 1 except that the following changes were made to Synthesis Example 1: the amount of 2, 2'-azobisisobutyronitrile was changed to 0.0411 g, the amount of butyl acrylate to 29.5 g, the amount of 2-hydroxyethyl methacrylate to 0.5 g, the amount of 4-cyano-4- [ (dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid to 1.009 g. Accordingly, a block copolymer (A-3) was obtained. In the obtained block copolymer, the rate of polymerization of each of the monomers was as follows: 98%for the butyl acrylate; 100%for the 2-hydroxyethyl methacrylate; and 99%for AM-130G. The molecular weight was calculated by GPC, and it was found that the number average molecular weight was 17625, and the molecular weight distribution was 1.31.

(Synthesis Example 4: Synthesis of Block Copolymer (A-4) )

Polymerization was carried out as in Synthesis Example 1 except that the following changes were made to Synthesis Example 1: the amount of butyl acrylate was changed to 34.0 g, the amount of 2-hydroxyethyl methacrylate to 1.0 g, and the amount of AM-130G to 15.0 g. Accordingly, a block copolymer (A-4) was obtained. In the obtained block copolymer, the rate of polymerization of each of the monomers was as follows: 96%for the butyl acrylate; 100%for the 2-hydroxyethyl methacrylate; and 99%for AM-130G. The molecular weight was calculated by GPC, and it was found that the number average molecular weight was 9289, and the molecular weight distribution was 1.32.

(Synthesis Example 5: Synthesis of Block Copolymer (A-5) )

Polymerization was carried out as in Synthesis Example 1 except that the following changes were made to Synthesis Example 1: the amount of butyl acrylate was changed to 24.0 g, the amount of 2-hydroxyethyl methacrylate to 1.0 g, and the amount of AM-130G to 25.0 g. Accordingly, a block copolymer (A-5) was obtained. In the obtained block copolymer, the rate of polymerization of each of the monomers was as follows: 97%for the butyl acrylate; 100%for the 2-hydroxyethyl methacrylate; and 98%for AM-130G. The molecular weight was calculated by GPC, and it was found that the number average molecular weight was 9351, and the molecular weight distribution was 1.28.

(Synthesis Example 6: Synthesis of Block Copolymer (A-6) )

To a four-neck flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen inlet tube, 0.0821 g of 2, 2'-azobisisobutyronitrile, which was used as a polymerization initiator, 8.5 g of lauryl acrylate, 20.5 g of butyl acrylate, 1.0 g of 2-hydroxyethyl methacrylate, and 30.0 g of diethylene glycol dimethyl ether were added, and the contents were bubbled with nitrogen at a flow rate of 50 ml/min for 30 minutes. Next, 2.018 g of 4-cyano-4- [ (dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid, which was used as a RAFT agent, was added, and the contents were bubbled with nitrogen for 30 minutes. After the bubbling was finished, the contents were heated to 70℃ and stirred for 2.5 hours, under a nitrogen stream. Thus, a polymerization reaction was carried out, and, accordingly, a first block copolymer solution was obtained. To this solution, a mixed solution containing 20.0 g of methoxypolyethylene glycol #550 acrylate (AM-130G, manufactured by Shin-Nakamura Chemical Co., Ltd. ) in 20.0 g of diethylene glycol dimethyl ether was added. The mixed solution had been bubbled with nitrogen for 30 minutes in advance. The contents were stirred at 70℃ for 19 hours. Thus, a polymerization reaction was carried out, and, accordingly, an AB-type block copolymer (A-6) , which included a hydrophilic segment and a hydrophobic segment, was obtained. In the obtained block copolymer, the rate of polymerization of each of the monomers was as follows: 99%for the lauryl acrylate; 94%for the butyl acrylate; 100%for the 2-hydroxyethyl methacrylate; and 94%for AM-130G. The molecular weight was calculated by GPC, and it was found that the number average molecular weight was 8477, and the molecular weight distribution was 1.25.

(Synthesis Example 7: Synthesis of Block Copolymer (A-7) )

Polymerization was carried out as in Synthesis Example 1 except that the following changes were made to Synthesis Example 1: the amount of 2, 2'-azobisisobutyronitrile was changed to 0.1368 g, the amount of butyl acrylate to 27.5 g, the amount of 2-hydroxyethyl methacrylate to 2.5 g, and the amount of 4-cyano-4- [ (dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid to 3.364 g. Accordingly, a block copolymer (A-7) was obtained. In the obtained block copolymer, the rate of polymerization of each of the monomers was as follows: 98%for the butyl acrylate; 100%for the 2-hydroxyethyl methacrylate; and 97%for AM-130G. The molecular weight was calculated by GPC, and it was found that the number average molecular weight was 5941, and the molecular weight distribution was 1.21.

(Comparative Synthesis Example-1: Synthesis of Random Copolymer (E-1) )

To a four-neck flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen inlet tube, 0.0821 g of 2, 2'-azobisisobutyronitrile, which was used as a polymerization initiator, 29.0 g of butyl acrylate, 1.0 g of 2-hydroxyethyl methacrylate, 20.0 g of methoxypolyethylene glycol #550 acrylate (AM-130G, manufactured by Shin-Nakamura Chemical Co., Ltd. ) , and 40.0 g of diethylene glycol dimethyl ether were added, and the contents were bubbled with nitrogen at a flow rate of 50 ml/min for 30 minutes. Next, 2.018 g of 4-cyano-4- [ (dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid, which was used as a RAFT agent, was added, and the contents were bubbled with nitrogen for 30 minutes. After the bubbling was finished, the contents were heated to 70℃ and stirred for 6 hours, under a nitrogen stream. Thus, a polymerization reaction was carried out, and, accordingly, a random copolymer (E-1) was obtained. In the obtained random copolymer, the rate of polymerization of each of the monomers was as follows: 99%for the butyl acrylate; 100%for the 2-hydroxyethyl methacrylate; and 97%for AM-130G. The molecular weight was calculated by GPC, and it was found that the number average molecular weight was 9732, and the molecular weight distribution was 1.22.

(Comparative Synthesis Example-2: Synthesis of Block Copolymer (E-2) )

To a four-neck flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen inlet tube, 0.0821 g of 2, 2'-azobisisobutyronitrile, which was used as a polymerization initiator, 30.0 g of butyl acrylate, and 30.0 g of diethylene glycol dimethyl ether were added, and the contents were bubbled with nitrogen at a flow rate of 50 ml/min for 30 minutes. Next, 2.018 g of 4-cyano-4- [ (dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid, which was used as a RAFT agent, was added, and the contents were bubbled with nitrogen for 30 minutes. After the bubbling was finished, the contents were heated to 70℃ and stirred for 2.5 hours, under a nitrogen stream. Thus, a polymerization reaction was carried out, and, accordingly, a first block copolymer solution was obtained. To this solution, a mixed solution containing 20.0 g of methoxypolyethylene glycol #550 acrylate (AM-130G, manufactured by Shin-Nakamura Chemical Co., Ltd. ) in 20.0 g of diethylene glycol dimethyl ether was added. The mixed solution had been bubbled with nitrogen for 30 minutes in advance. The contents were stirred at 70℃ for 19 hours. Thus, a polymerization reaction was carried out, and, accordingly, an AB-type block copolymer (E-2) , which included a hydrophilic segment and a hydrophobic segment, was obtained. In the obtained block copolymer, the rate of polymerization of each of the monomers was as follows: 97%for the butyl acrylate; and 99%for AM-130G. The molecular weight was calculated by GPC, and it was found that the number average molecular weight was 10305, and the molecular weight distribution was 1.21.

(Comparative Synthesis Example-3: Synthesis of Block Copolymer (E-3) )

Polymerization was carried out as in Synthesis Example 1 except that the following changes were made to Synthesis Example 1: the amount of 2, 2'-azobisisobutyronitrile was changed to 0.3248 g, the amount of butyl acrylate to 27.5 g, the amount of 2-hydroxyethyl methacrylate to 2.5 g, and the amount of 4-cyano-4- [ (dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid to 8.037 g. Accordingly, a block copolymer (E-3) was obtained. In the obtained block copolymer, the rate of polymerization of each of the monomers was as follows: 97%for the butyl acrylate; 100%for the 2-hydroxyethyl methacrylate; and 96%for AM-130G. The molecular weight was calculated by GPC, and it was found that the number average molecular weight was 2631, and the molecular weight distribution was 1.34.

(Comparative Synthesis Example-4: Synthesis of Block Copolymer (E-4) )

Polymerization was carried out as in Synthesis Example 1 except that the following changes were made to Synthesis Example 1: the amount of 2, 2'-azobisisobutyronitrile was changed to 0.0274 g, the amount of butyl acrylate to 29.75 g, the amount of 2-hydroxyethyl methacrylate to 0.25 g, and the amount of 4-cyano-4- [ (dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid to 0.673 g. Accordingly, a block copolymer (E-4) was obtained. In the obtained block copolymer, the rate of polymerization of each of the monomers was as follows: 96%for the butyl acrylate; 100%for the 2-hydroxyethyl methacrylate; and 98%for AM-130G. The molecular weight was calculated by GPC, and it was found that the number average molecular weight was 27532, and the molecular weight distribution was 1.33.

[Table 1]

Table 1

(Preparation Example 1: Preparation of Water-Dispersible Isocyanate Composition (B-1) )

To a four-neck flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen inlet tube, 15.0 g of the block copolymer (A-1) , 1.8 g of diethylene glycol dimethyl ether, and 25.6 g of an isocyanate compound Burnock DN-902S, manufactured by DIC Corporation, which was used as the isocyanate compound, were added, and the contents were heated to 105℃ with stirring. Thus, a reaction was carried out at the temperature for 6 hours, and, accordingly, a water-dispersible isocyanate composition (B-1) , which had a non-volatile component content of 78%and an isocyanate group (NCO group) content of 13%, was obtained.

(Preparation Examples 2 to 6: Preparation of Water-Dispersible Isocyanate Compositions (B-2 to B-7) )

By using a process similar to that for Preparation Example 1, water-dispersible isocyanate compositions (B-2) to (B-7) were prepared in accordance with the mixing amounts indicated in Table 2-1.

(Comparative Preparation Example 1: Preparation of Water-Dispersible Isocyanate Composition (F-1) for Comparison)

As with Preparation Example 1, to a four-neck flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen inlet tube, 15.0 g of the random copolymer (E-1) , 18.3 g of diethylene glycol dimethyl ether, and 51.3 g of an isocyanate compound Burnock DN-902S, manufactured by DIC Corporation, were added, and the contents were heated to 105℃ with stirring. Thus, a reaction was carried out at the temperature for 6 hours, and, accordingly, a water-dispersible isocyanate composition (F-1) , which had a non-volatile component content of 78%and an NCO group content of 14.2%, was obtained.

(Comparative Preparation Examples 2 to 4: Preparation of Water-Dispersible Isocyanate Compositions (F-2) to (F-4) for Comparison)

By using a process similar to that for Comparative Preparation Example 1, water-dispersible isocyanate compositions (F-2) to (F-4) were prepared in accordance with the mixing amounts indicated in Table 2-2.

[Table 2]

[Table 3]

(Example 1: Preparation of Aqueous Dispersion (C-1) )

20 g of deionized water was added to a 50-ml beaker, and 5 g of the prepared water-dispersible isocyanate composition (B-1) was added thereto. The contents were stirred for 10 minutes using a stirring bar, and, accordingly, an aqueous dispersion (C-1) was prepared. A water dispersibility, the isocyanate group content, and the isocyanate group retention ratio of the aqueous dispersion (C-1) were measured.

Water dispersibility: diameters of dispersed particles of less than 500 nm were rated as "A" , 500 nm to 1 μm as "B" , and greater than 1 μm as "C" .

Isocyanate group (NCO group) content (%) : the isocyanate group content was determined in the following manner; a predetermined amount of a sample was dissolved in 10 ml of a 1 N solution of dibutylamine in toluene; the solution was allowed to stand at room temperature for 5 minutes and thereafter diluted with 50 ml of isopropanol; and 3 drops of a bromophenol blue solution were added, and titration was performed with 0.5 N HCl.

[Math. 1]

B: the amount (ml) of an aqueous 0.5 mol/l HCl solution consumed in a blank titration test

T: the amount (ml) of the aqueous 0.5 mol/l HCl solution consumed in a titration test for the sample

F: a factor of the aqueous 0.5 mol/l HCl solution

S: the amount (g) of the sample

Isocyanate group (NCO group) retention ratio: the NCO group retention ratio was calculated according to an equation, NCO group retention ratio = (NCO group content after 24 hours) / (initial NCO group content) . Hydroxy value: the hydroxy value was calculated according to an equation, hydroxy value (mg/gKOH) = (molar concentration of the OH group-containing monomer in the block copolymer) × 56100. (Examples 2 to 7: Preparation of Aqueous Dispersions (C-2) to (C-7) )

Aqueous dispersions (C-2) to (C-7) were prepared as in Example 1 except that the water-dispersible isocyanate composition was replaced with a different water-dispersible isocyanate composition as shown in Table 3-1.

(Comparative Example 1: Preparation of Aqueous Dispersions (G-1) for Comparison)

20 g of deionized water was added to a 50-ml beaker, and 5 g of the prepared water-dispersible isocyanate composition (F-1) was added thereto. The contents were stirred for 10 minutes, and, accordingly, an aqueous dispersion (G-1) for comparison was prepared.

(Comparative Examples 2 to 4: Preparation of Aqueous Dispersions (G-2) to (G-4) for Comparison)

Aqueous dispersions (G-2) to (G-4) for comparison were prepared by using a process similar to that for Comparative Example 1.

[Table 4]

[Table 5]

(Examples 8 to 14: Preparation of Coating Formulation Mixtures (D-1) to (D-7) and Production of Cured Coatings)

In accordance with Table 4-1, each of the water-dispersible polyisocyanate compositions (B-1) to (B-7) , a compound having an active-hydrogen-containing group, and water were mixed together. The compound having an active-hydrogen-containing group used was a hydroxy-group-containing acrylic resin emulsion (Burnock WE-306, manufactured by DIC Corporation) . Thus, coating formulation mixtures (D-1) to (D-7) were prepared. Each of the coating formulation mixtures was applied onto a glass plate by using a 150-μm applicator and dried at room temperature for 30 minutes. Subsequently, the resultant was heated at 80℃ for 1 hour. Accordingly, cured coatings were produced.

Coating appearance: coatings with no fish eyes or blushing defects were rated as "A" ; coatings with a few fish eyes and/or blushing defects as "B" ; and coatings with more than a few fish eyes and/or blushing defects as "C" . Solvent resistance: the surface of the coatings was rubbed with a felt cloth impregnated with xylene; visual examination was performed to check for the presence or absence of coating appearance anomalies; and after the surface was rubbed in a reciprocating manner 200 times, if the substrate glass was not exposed, the coating was rated as "A" , and if the substrate glass was exposed, the coating was rated as "B" .

(Comparative Examples 5 and 6: Preparation of Coating Formulation Mixtures (H-1) and (H-2) and Production of Cured Coatings)

In accordance with Table 4-2, each of the water-dispersible polyisocyanate compositions (F-1) and (F-2) , a compound having an active-hydrogen-containing group, and water were mixed together. The compound having an active-hydrogen-containing group used was a hydroxy-group-containing acrylic resin emulsion (Burnock WE-306, manufactured by DIC Corporation) . Thus, coating formulation mixtures (H-1) and (H-2) were prepared. Each of the coating formulation mixtures was applied onto a glass plate by using a 150-μm applicator and dried at room temperature for 30 minutes. Subsequently, the resultant was heated at 80℃ for 1 hour. Accordingly, cured coatings were produced.

[Table 6]

[Table 7]

(Examples 15 to 21: Preparation of Coating Formulation Mixtures (D-8) to (D-14) and Production of Cured Coatings)

In accordance with Table 5-1, each of the water-dispersible polyisocyanate compositions (B-1) to (B-7) , a compound having an active-hydrogen-containing group, and water were mixed together. The compound having an active-hydrogen-containing group used was a hydroxy-group-containing acrylic resin dispersion (Burnock WD-551, manufactured by DIC Corporation) . Thus, coating formulation mixtures (D-8) to (D-14) were prepared. Each of the coating formulation mixtures was applied onto a glass plate by using a 150-μm applicator and dried at room temperature for 30 minutes. Subsequently, the resultant was heated at 80℃ for 1 hour. Accordingly, cured coatings were produced.

(Comparative Examples 7 and 8: Preparation of Coating Formulation Mixtures (H-3) and (H-4) and Production of Cured Coatings)

In accordance with Table 5-2, each of the water-dispersible polyisocyanate compositions (F-1) and (F-2) , a compound having an active-hydrogen-containing group, and water were mixed together. The compound having an active-hydrogen-containing group used was a hydroxy-group-containing acrylic resin dispersion (Burnock WD-551, manufactured by DIC Corporation) . Thus, coating formulation mixtures (H-3) and (H-4) were prepared. Each of the coating formulation mixtures was applied onto a glass plate by using a 150-μm applicator and dried at room temperature for 30 minutes. Subsequently, the resultant was heated at 80℃ for 1 hour. Accordingly, cured coatings were produced.

[Table 8]

[Table 9]

[Industrial Applicability]

Compositions of the present invention exhibit excellent storage stability even in an aqueous system and are, therefore, suitable for use as a material for a curable aqueous coating formulation.

Claims

A composition comprising:

an isocyanate compound; and

a block copolymer, wherein

the block copolymer has a number average molecular weight of 3000 to 20000,

the block copolymer is an AB-type block copolymer including a hydrophilic segment A and a hydrophobic segment B, the hydrophilic segment A including an end-capped polyoxyalkylene group, the hydrophobic segment B including a copolymer of a hydrophobic monomer and a monomer having an active-hydrogen-containing group that is reactive with isocyanate, and

the block copolymer has a hydroxy value of 3 to 25 mg/gKOH.
The composition according to Claim 1, further comprising an aqueous organic solvent.
The composition according to Claim 1 or 2, wherein, in the block copolymer, the hydrophilic segment A is present in an amount of 30 to 50 mass%of a total mass of the block copolymer.
A coating formulation comprising:

the composition according to any one of Claims 1 to 3; and

a compound having an active-hydrogen-containing group.
The coating formulation according to Claim 4, further comprising water.
A coating comprising a cured product of the coating formulation according to Claim 4 or 5.
A multilayer body comprising:

the coating according to Claim 6; and

a base member.