Active energy ray-curable composition, water-based emulsion composition, laminate, and coating agent composition

Abstract

Provided is a forced emulsification type energy ray-curable composition having high nonvolatile content, excellent storage stability at room temperature and at high temperature, excellent freeze-thaw stability, excellent adhesion of a coating film to a substrate at the time of coating, and excellent water resistance, a water-based emulsion composition, a laminate, and a coating agent composition. In the energy ray-curable composition containing two or more surfactants, at least one of the surfactants is a surfactant (B1) having two or more reactive groups. The energy ray-curable composition is used in the water-based emulsion composition or the coating agent composition.

Description

Technical Field

[0001] This invention relates to active energy ray-curable compositions, aqueous emulsion compositions, laminates, and coating agent compositions. More specifically, it relates to aqueous emulsion compositions with excellent storage stability at room temperature and high temperatures and high non-volatile components, particularly aqueous emulsion compositions formed by forced emulsification of active energy ray-curable compositions, and coating agent compositions.

[0002] This application claims priority based on Japanese Patent Application No. 2020-182985 filed on October 30, 2020 and Japanese Patent Application No. 2021-146647 filed on September 9, 2021, the contents of which are incorporated herein by reference. Background Technology

[0003] As an active energy ray curable resin, urethane (meth) acrylates are known to be obtained by reacting diol compounds such as polyester glycol and polyether glycol, diisocyanate compounds such as isophorone diisocyanate and diphenylmethane diisocyanate, and hydroxyl-containing (meth) acrylates such as hydroxyethyl acrylate, and are used in wood coatings, plastic coatings and other applications.

[0004] Such urethane (meth)acrylates typically have high viscosity. Therefore, when using them, they are diluted with organic solvents and reactive diluents to adjust the viscosity before coating, and then irradiated with active energy rays such as ultraviolet light to form a cured coating film.

[0005] However, dilution using organic solvents presents problems under VOC regulations in recent years, which address air pollution, work environment, and fire hazards. On the other hand, dilution using reactive diluents sometimes requires large amounts of reactive diluent to achieve low viscosity, making it difficult to obtain adequate coating properties.

[0006] Under such circumstances, the requirements for water-dispersed and other water-based systems have become increasingly stringent in recent years.

[0007] Patent document 1 discloses a self-emulsifying active energy ray curable resin composition, which manufactures a urethane (meth) acrylate containing carboxyl groups and alkylene glycol chains in a solvent-free manner, and further emulsifies the urethane (meth) acrylate by neutralizing the carboxyl groups and adding water.

[0008] Patent document 2 proposes a forced emulsification type active energy ray curable aqueous emulsion composition, which disperses a multifunctional acrylate compound and a photopolymerization initiator in an aqueous medium in the presence of an emulsifier.

[0009] Patent document 3 discloses a forced emulsification type emulsion coating composition, which is formed by dispersing mono- or polypentaerythritol (meth)acrylate, urethane poly(meth)acrylate compound, and photopolymerization initiator in water in the presence of reactive surfactant.

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent Application Publication No. 2020-152786

[0013] Patent Document 2: Japanese Patent Application Publication No. 2012-149141

[0014] Patent Document 3: Japanese Patent Application Publication No. 09-137081 Summary of the Invention

[0015] The problem that the invention aims to solve

[0016] However, in the technology disclosed in Patent Document 1, because it is a self-emulsifying type, it is difficult to concentrate high non-volatile components at low viscosity, thus causing difficulties in drying the coating during film formation. Furthermore, the storage stability and freeze-thaw stability of the liquid at high temperatures are not considered. Moreover, the flexibility of the coating is also not taken into account.

[0017] Furthermore, in the technology disclosed in Patent Document 2, forced emulsification was performed using a non-reactive emulsifier in the examples. When the emulsion composition obtained using such a non-reactive emulsifier is formed into a cured coating film, the non-reactive emulsifier exists in a free state, resulting in insufficient water resistance. It should be noted that although reactive emulsifiers are illustrated in that document, the above-mentioned aspects are not considered at all.

[0018] Furthermore, while the technology disclosed in Patent Document 3 uses a reactive emulsifier for forced emulsification, it does not consider the liquid's storage stability at high temperatures or its freeze-thaw stability. Additionally, the water resistance test is limited to a warm water test at 80°C. With increasing performance requirements in recent years, there is a demand for substances that can withstand more stringent water resistance tests.

[0019] Against this backdrop, the present invention aims to provide an active energy ray curable composition, an aqueous emulsion composition, a laminate, and a coating agent composition that are forced emulsified, have high non-volatile components, excellent storage stability at room temperature and high temperature, excellent freeze-thaw stability, and excellent adhesion and water resistance of the coating film to the substrate during coating.

[0020] Methods for solving problems

[0021] One embodiment of the present invention includes the following configuration.

[0022] [1] An active energy ray curing composition, which is an active energy ray curing composition containing two or more surfactants, wherein at least one of the surfactants is a surfactant having two or more reactive groups (B1).

[0023] [2] In the active energy ray curing composition according to [1], the content of the surfactant (B1) is 50% by weight or more relative to the total mass of the surfactant.

[0024] [3] According to the active energy ray curable composition described in [1] or [2], the surfactant (B1) has a polyoxyethylene chain in its structure.

[0025] [4] The active energy ray curable composition according to any one of [1] to [3], wherein the surfactant (B1) is urethane (meth) acrylate.

[0026] [5] The active energy ray curable composition according to any one of [1] to [4] comprises a surfactant (B2) (excluding the surfactant (B1) described above), wherein the surfactant (B2) is a surfactant represented by the following general formula (1).

[0027] XO-(Y1O) m -(Y2O) n -SO3Z…(1)

[0028] (Where, X is a functional group with a double bond. Y1 and Y2 are alkylene groups, and Y1 and Y2 are different groups. Z is a counterion. m is an integer greater than or equal to 1, and n is an integer greater than or equal to 0.)

[0029] [6] The active energy ray curing composition according to any one of [1] to [5] further contains a photopolymerizable compound (A).

[0030] [7] According to the active energy ray curable composition described in [6], the above photopolymerizable compound (A) contains (meth)acrylate monomer (A1).

[0031] [8] According to the active energy ray curable composition of [6], the above photopolymerizable compound (A) comprises urethane (meth)acrylate (A2) (wherein excluding the above surfactant (B1)).

[0032] [9] The active energy ray curable composition according to any one of [6] to [8] contains 40 to 99% by weight of the above-mentioned photopolymerizable compound (A) relative to 100% by weight of the total of the above-mentioned photopolymerizable compound (A) and the above-mentioned surfactant.

[0033]

[10] The active energy ray curable composition according to any one of [1] to [9] further contains a photopolymerization initiator (C).

[0034]

[11] The active energy ray curing composition according to any one of [1] to

[10] contains water.

[0035]

[12] An aqueous emulsion composition comprising any one of [1] to

[10] an active energy ray curing composition.

[0036]

[13] A coating composition comprising any one of the active energy ray curing compositions described in [1] to

[11] .

[0037]

[14] A laminate having at least one layer formed of any one of the active energy ray curing compositions described in [1] to

[10] .

[0038]

[15] An aqueous emulsion composition containing an active energy ray curable composition, wherein the coating formed under the following conditions has a pencil hardness of 2H or higher as determined by a 1kg load according to the method of JIS K 5600-5-4.

[0039] <Coating film formation conditions>

[0040] The aqueous emulsion composition was applied to the surface of a 125 μm thick easily bondable polyethylene terephthalate film using a bar coater. After drying at 100°C for 2 minutes, a high-pressure mercury lamp was used to apply the emulsion composition at a cumulative light intensity of 450 mJ / cm². 2 It is cured by ultraviolet irradiation to form a coating with a thickness of 10μm.

[0041] Invention Effects

[0042] According to the present invention, an active energy ray curable composition, an aqueous emulsion composition, a laminate, and a coating agent composition are provided, which are characterized by forced emulsification, high non-volatile content, excellent storage stability at room temperature and high temperature, excellent freeze-thaw stability, and excellent adhesion and water resistance of the coating film to the substrate during coating. Detailed Implementation

[0043] The present invention will now be described in detail.

[0044] It should be noted that in this invention, "(meth)acrylic acid" refers to acrylic acid or methacrylic acid. "(meth)acryloyl" refers to acryloyl or methacryloyl. "(meth)acrylate" refers to acrylate or methacrylate.

[0045] Number-average molecular weight is a conversion based on the molecular weight of standard polystyrene, and is determined, for example, by high-performance liquid chromatography (HPLC) based on the hydroxyl value determined according to JIS K 1577. In HPLC, for example, it is determined by using four columns in series in a HPLC system (Waters Corporation, "ACQUITY APC system"): one ACQUITY APC XT 450 column, one ACQUITY APC XT 200 column, and two ACQUITY APC XT 45 columns.

[0046] The weight-average molecular weight is the weight-average molecular weight converted from the standard polystyrene molecular weight. For example, it can be determined by using four columns in series in a high-performance liquid chromatograph (Waters Corporation, "ACQUITY APC system"): one ACQUITY APC XT 450 column, one ACQUITY APC XT 200 column, and two ACQUITY APC XT 45 columns.

[0047] In this specification, the "~" sign indicating a range of values ​​is used to encompass the values ​​described before and after it as the lower and upper limits.

[0048] [Active Energy Ray Curing Composition]

[0049] The active energy ray curing composition of the present invention contains two or more surfactants. At least one of the surfactants contained in the active energy ray curing composition of the present invention is a surfactant (B1) having two or more reactive groups (hereinafter simply referred to as "surfactant (B1)").

[0050] The active energy ray curing composition of the present invention is suitable for use in forced emulsification aqueous emulsion compositions.

[0051] <surfactants>

[0052] As a surfactant, it contains at least surfactant (B1), and preferably further contains surfactant (B2) other than surfactant (B1).

[0053] [Surfactant (B1)]

[0054] In this invention, by using at least one of two or more surfactants, specifically surfactant (B1) having two or more reactive groups, a small-particle-size and uniform emulsion composition can be obtained. Surfactant (B1) not only assists in emulsification but also greatly contributes to the stability of the emulsion, particularly its freeze-thaw stability.

[0055] Surfactant (B1) is either water-soluble or water-dispersible. "Water-soluble" means that it can maintain a uniform appearance when prepared as a 10% by weight aqueous solution. "Water-dispersible" means that it is dispersed when prepared as a 10% by weight aqueous dispersion with a particle size (median particle size) of less than 100 nm.

[0056] Particle size (median particle size) was measured using a laser scattering / diffraction apparatus (manufactured by Horiba Corporation; LA950V2).

[0057] Examples of reactive groups in surfactant (B1) include functional groups with double bonds, preferably (meth)acryloyl or allyl. The main chain structure of surfactant (B1) is not limited as long as it has two or more reactive groups. Furthermore, surfactant (B1) preferably has hydrophilic groups in its molecule. The hydrophilic groups are preferably nonionic, more preferably polyoxyethylene chains, and even more preferably polyoxyethylene chains.

[0058] Specifically, examples include polyvinyl alcohol, acrylate (meth)acrylate, urethane (meth)acrylate, polyester (meth)acrylate, and polyether (meth)acrylate having two or more functional groups with double bonds.

[0059] Among them, considering the hydrophilicity of urethane bonds and the ease of molecular design control, urethane (meth) acrylates that are water-soluble or water-dispersible and have two or more functional groups with double bonds are preferred.

[0060] Examples of urethane (meth)acrylates that satisfy these conditions include, for example, the reaction products of polyisocyanates (b1), hydroxyl-containing (meth)acrylates (b2), and polyoxyethylene-containing compounds (b3). Other examples include the reaction products of polyisocyanates (b1), hydroxyl-containing (meth)acrylates (b2), polyoxyethylene-containing compounds (b3), and carboxyl-containing polyols (b4), i.e., substances obtained by neutralizing some or all of the carboxyl groups with a base.

[0061] Examples of polyisocyanates (b1) include aromatic polyisocyanates, aliphatic polyisocyanates, cycloaliphatic polyisocyanates, or trimeric compounds of these polyisocyanates or polymeric compounds of more than one polymer, urethane polyisocyanates, biuret polyisocyanates, adduct polyisocyanates, and water-dispersible polyisocyanates.

[0062] Examples of aromatic polyisocyanates include toluene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, phenylene diisocyanate, tetramethylphenylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate. Examples of aliphatic polyisocyanates include pentamethane diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and lysine triisocyanate. Examples of alicyclic polyisocyanates include hydrogenated diphenylmethane diisocyanate, hydrogenated phenylene diisocyanate, isophorone diisocyanate, and norbornene diisocyanate.

[0063] These polyisocyanates (b1) can be used alone or in combination of two or more.

[0064] From the perspective of reducing yellowing, the preferred polyisocyanates are aliphatic diisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate; alicyclic diisocyanates such as hydrogenated diphenylmethane diisocyanate, hydrogenated phenyl diisocyanate, isophorone diisocyanate, and norbornene diisocyanate; or trimers of these polyisocyanates; urea-formate polyisocyanates; biuret-formate polyisocyanates; and adduct-type polyisocyanates. Hexamethylene diisocyanate is more preferred. From the perspectives of excellent emulsifying properties, emulsion stability, coating film softness, and low crystallinity, the trimer compound of cyanate, the biuret-type polyisocyanate of hexamethylene diisocyanate, the adduct-type polyisocyanate of hexamethylene diisocyanate, the isophorone diisocyanate, the hydrogenated diphenylmethane diisocyanate, and the hydrogenated phenyldimethyl diisocyanate are further preferred, namely the trimer compound of hexamethylene diisocyanate, the isophorone diisocyanate, and the hydrogenated phenyldimethyl diisocyanate.

[0065] The hydroxyl-containing (meth)acrylate (b2) may have one, two, or more than three vinyl unsaturated groups.

[0066] Examples of hydroxyl-containing (meth)acrylates having an vinyl unsaturated group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 2-hydroxyethylacryloyl phosphate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, dipropylene glycol (meth)acrylate, fatty acid-modified glycidyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate.

[0067] Examples of hydroxyl-containing (meth)acrylates having two vinyl unsaturated groups include glycerol di(meth)acrylate and 2-hydroxy-3-acryloyl-oxypropyl methacrylate.

[0068] Examples of hydroxyl-containing (meth)acrylates having three or more vinyl unsaturated groups include pentaerythritol tri(meth)acrylate, caprolactone-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, caprolactone-modified dipentaerythritol penta(meth)acrylate, and ethylene oxide-modified dipentaerythritol penta(meth)acrylate.

[0069] Hydroxyl-containing (meth)acrylates (b2) can be used alone or in combination of two or more.

[0070] Among these, when the flexibility of the coating film is important, hydroxyl-containing (meth)acrylates containing an vinyl unsaturated group are preferred, more preferably hydroxyalkyl (meth)acrylates with 2 to 4 carbon atoms such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, and polypropylene glycol mono(meth)acrylate, and even more preferably 2-hydroxyethyl (meth)acrylate and polyethylene glycol mono(meth)acrylate.

[0071] When the hardness of the coating film is important, hydroxyl-containing (meth)acrylates having three or more vinyl unsaturated groups are preferred, more preferably pentaerythritol tri(meth)acrylate or dipentaerythritol penta(meth)acrylate, and even more preferably dipentaerythritol penta(meth)acrylate.

[0072] As a compound containing polyoxyethylene (b3), polyethylene glycol can be exemplified, for example.

[0073] As a carboxyl-containing polyol (b4), it is preferably an aliphatic polyhydroxycarboxylic acid, more preferably a diol monocarboxylic acid or its neutralized salt with a molecular weight of 100 to 200, particularly preferably dimethylolbutyric acid or dimethylolpropionic acid, and even more preferably dimethylolbutyric acid. Part or all of the carboxyl group derived from the carboxyl-containing polyol (b4) is neutralized by a base to become a neutralized salt, thus becoming hydrophilic.

[0074] The weight-average molecular weight of the surfactant (B1) is preferably 500 or more, more preferably 1,000 or more. If the weight-average molecular weight of the surfactant (B1) is above the lower limit mentioned above, the cured coating film is less likely to become brittle. The weight-average molecular weight of the surfactant (B1) is preferably 50,000 or less, more preferably 20,000 or less. If the weight-average molecular weight of the surfactant (B1) is below the upper limit mentioned above, it achieves an appropriate viscosity and is easy to handle, and the hardness of the cured coating film is increased. The lower and upper limits of the weight-average molecular weight of the surfactant (B1) can be combined arbitrarily, for example, preferably 500 to 50,000, more preferably 1,000 to 20,000.

[0075] When the surfactant (B1) is a urethane (meth)acrylate, its weight-average molecular weight is preferably 500 or more, more preferably 1,000 or more, and particularly preferably 2,000 or more. If the weight-average molecular weight of the urethane (meth)acrylate is above the lower limit mentioned above, the cured coating film is less likely to become brittle. The weight-average molecular weight of the urethane (meth)acrylate is preferably 50,000 or less, more preferably 20,000 or less. If the weight-average molecular weight of the urethane (meth)acrylate is below the upper limit mentioned above, it achieves a suitable viscosity and is easy to handle, and the hardness of the cured coating film is increased. The lower and upper limits of the weight-average molecular weight of the surfactant (B1) can be combined arbitrarily, for example, preferably 500 to 50,000, more preferably 1,000 to 20,000.

[0076] [Surfactant (B2)]

[0077] Surfactant (B2) is a surfactant other than surfactant (B1), and preferably a surfactant having a reactive group. By further including surfactant (B2) in addition to surfactant (B1), a small-particle-size and uniform emulsion can be easily obtained.

[0078] The surfactant (B2) is preferably a surfactant having a functional group containing a double bond. Preferably, such a functional group is (meth)acryloyl or allyl.

[0079] The surfactant (B2) preferably has a straight-chain structure, and more preferably has a straight-chain polyoxyalkylene chain. As the alkylene group of the straight-chain polyoxyalkylene chain, it is preferably an alkylene group having 2 to 4 carbon atoms.

[0080] The surfactant (B2) is further preferably composed of a functional group with a double bond at one end of the two ends of the straight-chain polyoxyethylene chain, and a hydrophilic group at the other end.

[0081] The hydrophilic group described above is preferably an ionic group (cationic, anionic, or amphoteric), more preferably anionic, and particularly preferably a sulfonate group.

[0082] As a surfactant (B2), from the perspective of obtaining a smaller particle size and a uniform aqueous emulsion composition, a surfactant having an unsaturated bond with free radical reactivity in the molecule is preferred, and a surfactant represented by the following general formula (1) is more preferred.

[0083] XO-(Y1O) m -(Y2O) n -SO3Z…(1)

[0084] (Where, X is a functional group with a double bond. Y1 and Y2 are each independently an alkylene group, and Y1 and Y2 are different groups. Z is a counterion. m is an integer greater than or equal to 1, and n is an integer greater than or equal to 0.)

[0085] The functional group with a double bond for X is preferably (meth)acryloyl or allyl.

[0086] Y1 and Y2 are preferably alkylene groups having 2 to 4 carbon atoms.

[0087] m is preferably 2 or more, more preferably 3 or more. The upper limit of m is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less.

[0088] n is preferably 1 or more, more preferably 2 or more. The upper limit of n is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less.

[0089] As Z, NH4 is preferred. + Na + NH4 is particularly preferred. + .

[0090] Examples of surfactants (B2) include (meth)acrylate surfactants, allyl surfactants, maleic acid surfactants, and itaconic acid surfactants. Specifically, examples include sodium sulfoethyl methacrylate, ammonium sulfoethyl methacrylate, allyl-containing polyoxyethylene nonylphenyl ether sulfonate, polyoxyethylene lauryl ether maleate, polyoxyethylene lauryl ether methacrylate, polyoxyethylene nonylphenyl ether acrylate, and allyl-containing polyoxyethylene nonylphenyl ether. Only one type may be used, or two or more may be used in combination.

[0091] <Photopolymerizable compound (A)>

[0092] The active energy ray curing composition of the present invention preferably further comprises a photopolymerizable compound (A).

[0093] Examples of photopolymerizable compounds (A) include (meth)acrylate monomers (A1), urethane (meth)acrylates (A2) (excluding surfactant (B1)), acrylic (meth)acrylates, polyester (meth)acrylates, and polyether (meth)acrylates. From the perspective of low viscosity and easy phase inversion emulsification in solvent-free conditions, photopolymerizable compounds (A) preferably contain (meth)acrylate monomers (A1).

[0094] As a photopolymerizable compound (A), one can be used alone, or two or more can be used in combination. When high-viscosity compounds such as urethane acrylates are emulsified under solvent-free conditions, it is preferable to use low-viscosity compounds such as (meth)acrylate monomers (A1). Low-viscosity compounds such as (meth)acrylate monomers (A1) can also be added during the manufacture of urethane acrylates, in which case the compound acts as a diluent.

[0095] Examples of (meth)acrylate monomers (A1) include monofunctional (meth)acrylate monomers, difunctional (meth)acrylate monomers, and trifunctional or more functional (meth)acrylate monomers.

[0096] Examples of monofunctional (meth)acrylate monomers include methyl (meth)acrylate, ethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-phenoxy-2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, and 3-chloro-2-hydroxypropyl (meth)acrylate. Acrylates, glyceryl mono(meth)acrylates, glycidyl (meth)acrylates, lauryl (meth)acrylates, cyclohexyl (meth)acrylates, isobornyl (meth)acrylates, tricyclodecyl (meth)acrylates, dicyclopentenyl (meth)acrylates, dicyclopentenoxyethyl (meth)acrylates, dicyclopentyl (meth)acrylates, (2-methyl-2-ethyl-1,3-dioxolane-4-yl)-methyl(meth)acrylates, cyclohexanespiro-2-(1,3-dioxolane-4-yl)-methyl(meth)acrylates Acrylates, Cyclotrimethylolpropane methyl acetal acrylates, 3-Ethyl-3-oxetanebutyl methyl (meth)acrylates, γ-Butyrolactone (meth)acrylates, n-butyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecanyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, phenoxydiethylene glycol acrylates, benzene Oxygenated polyethylene glycol acrylate, nonylphenol propylene oxide modified (n=2.5) (meth)acrylate, 2-(meth)acryloyloxyethyl acid phosphate, 2-(meth)acryloyloxy-2-hydroxypropyl phthalate and other phthalic acid derivatives hemi(meth)acrylate, (meth)acrylate furfuryl ester, (meth)acrylate tetrahydrofurfuryl ester, carbitol (meth)acrylate, (meth)acrylate butoxyethyl ester, (meth)acryloylmorpholine, (meth)acrylate allyl ester, polyoxyethylene secondary alkyl ether acrylate.

[0097] Examples of difunctional (meth)acrylate monomers include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, propylene glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, butanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene oxide-modified bisphenol A type dimethacrylate, propylene oxide-modified bisphenol A type dimethacrylate, 1,6-hexanediol dimethacrylate, 1,6-hexanediol ethylene oxide-modified dimethacrylate, 1,9-nonanediol dimethacrylate, diglycidyl phthalate dimethacrylate, hydroxypentanoic acid-modified neopentyl glycol dimethacrylate, and 2-(meth)acryloyloxyethyl phosphate diester.

[0098] Examples of trifunctional or higher (meth)acrylate monomers include trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tri(meth)acryloyloxyethoxytrimethylolpropane, ethylene oxide-modified triacrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified pentaerythritol tetra(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, and caprolactone-modified pentaerythritol tetra(meth)acrylate.

[0099] (Meth)acrylate monomers (A1) can be used alone or in combination with two or more.

[0100] As the (meth)acrylate monomer (A1), from the perspective of easily obtaining a coating film with high hardness, a trifunctional or higher (meth)acrylate monomer is preferred, a tetrafunctional or higher (meth)acrylate monomer is more preferred, and a pentafunctional or higher (meth)acrylate monomer is even more preferred. Dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate are particularly preferred.

[0101] The hydroxyl values ​​of these trifunctional or higher (meth)acrylate monomers are typically 0–300 mg KOH / g. Preferably, the hydroxyl value of the trifunctional or higher (meth)acrylate monomers is 5 mg KOH / g or higher, more preferably 10 mg KOH / g or higher, even more preferably 20 mg KOH / g or higher, particularly preferably 30 mg KOH / g or higher, and most preferably 35 mg KOH / g or higher. If the hydroxyl value is above the lower limit mentioned above, the hydrophilicity is improved, and the storage stability, especially the freeze-thaw stability, is improved. Furthermore, the hydroxyl value of the trifunctional or higher (meth)acrylate monomers is preferably 150 mg KOH / g or lower, more preferably 130 mg KOH / g or lower, even more preferably 125 mg KOH / g or lower, particularly preferably 100 mg KOH / g or lower, and most preferably 60 mg KOH / g or lower. If the hydroxyl value is below the upper limit mentioned above, the storage stability and hardness at high temperatures are improved. The lower and upper limits of the hydroxyl value of trifunctional or higher (meth)acrylate monomers can be combined arbitrarily. For example, it is preferably 5 to 150 mg KOH / g, more preferably 10 to 130 mg KOH / g, even more preferably 20 to 125 mg KOH / g, particularly preferably 30 to 100 mg KOH / g, and most preferably 35 to 60 mg KOH / g.

[0102] From the perspective of easily obtaining a coating film with excellent flexibility, the (meth)acrylate monomer (A1) is preferably a monofunctional (meth)acrylate monomer. From the perspective of excellent emulsification and flexibility, it is more preferably (meth)acrylate phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxy polyethylene glycol acrylate, (meth)acrylate tetrahydrofurfuryl acrylate, (meth)acryloylmorpholine, polyoxyethylene secondary alkyl ether acrylate, and (meth)acrylate isobornyl ester. Particularly preferred are phenoxydiethylene glycol acrylate, phenoxy polyethylene glycol acrylate, and (meth)acrylate isobornyl ester.

[0103] From the perspective of easily obtaining a coating film with excellent flexibility, the photopolymerizable compound (A) preferably contains urethane (meth)acrylate (A2) (wherein, surfactant (B1) is excluded). The urethane (meth)acrylate (A2) is neither water-soluble nor water-dispersible. "Neither water-soluble nor water-dispersible" means that it does not meet both the definitions of "water-soluble" and "water-dispersible" mentioned above.

[0104] As urethane (meth)acrylate (A2), examples include reaction products of polyisocyanates, polyols and hydroxyl-containing (meth)acrylates, and reaction products of polyisocyanates and hydroxyl-containing (meth)acrylates. Among these, reaction products of polyisocyanates, polyols and hydroxyl-containing (meth)acrylates are preferred from the viewpoint of obtaining a soft coating film.

[0105] From the perspective of coating toughness, the reaction product of polyisocyanate (a1), polyester polyol (a2) and hydroxyl-containing (meth)acrylate (a3) ​​is particularly preferred as urethane (meth)acrylate (A2).

[0106] [Polyisocyanate (a1)]

[0107] Examples of polyisocyanates (a1) include aromatic polyisocyanates, aliphatic polyisocyanates, cycloaliphatic polyisocyanates, or trimeric compounds of these polyisocyanates or polymeric compounds of more than one polymer, urethane polyisocyanates, biuret polyisocyanates, adduct polyisocyanates, and water-dispersible polyisocyanates.

[0108] Examples of aromatic polyisocyanates include toluene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, phenylene diisocyanate, tetramethylphenylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate. Examples of aliphatic polyisocyanates include pentamethane diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and lysine triisocyanate. Examples of alicyclic polyisocyanates include hydrogenated diphenylmethane diisocyanate, hydrogenated phenylene diisocyanate, isophorone diisocyanate, and norbornene diisocyanate.

[0109] These polyisocyanates (a1) can be used alone or in combination of two or more.

[0110] From the perspective of minimizing yellowing, aliphatic diisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate, as well as alicyclic diisocyanates such as hydrogenated diphenylmethane diisocyanate, hydrogenated phenyldimethyl diisocyanate, isophorone diisocyanate, and norbornene diisocyanate are preferred. Isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated phenyldimethyl diisocyanate are more preferred. From the perspective of excellent film softness and low crystallinity, isophorone diisocyanate and hydrogenated phenyldimethyl diisocyanate are even more preferred.

[0111] [Polyester polyol (a2)]

[0112] As the polyester polyol (a2), it is preferably selected from at least one of the following groups: polyol and polycarboxylic acid condensation polymer, ring-opening polymer of cyclic ester compound, and reactant composed of polyol, polycarboxylic acid and cyclic ester compound. From the perspective of freedom of composition, polyol and polycarboxylic acid condensation polymer is particularly preferred.

[0113] As a polyol, it can be a diol or a triol or more.

[0114] Examples of diols include aliphatic diols, alicyclic diols, and aromatic diols. Examples of aliphatic diols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,4-tetramethylene glycol, 1,3-tetramethylene glycol, 2-methyl-1,3-trimethylene glycol, 1,5-pentamethylene glycol, neopentyl glycol, 1,6-hexamethylene glycol, 3-methyl-1,5-pentamethylene glycol, and 2,4-diethyl-1,5-pentamethylene glycol. Examples of alicyclic diols include 1,2-cyclohexanediethanol, 1,3-cyclohexanediethanol, 1,4-cyclohexanediethanol, spirodiol, tricyclodecanediethanol, adamantanediol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Examples of aromatic diols include bisphenols (bisphenol A, bisphenol B, bisphenol E, etc.), 4,4'-thiodiphenol, 4,4'-methylenediphenol, 4,4'-dihydroxybiphenyl, o-dihydroxybenzene, m-dihydroxybenzene, p-dihydroxybenzene, 2,5-naphthylenediol, p-xylenediol, and their ethylene oxide adducts and propylene oxide adducts.

[0115] Examples of alcohols with three or more components include glycerol, trimethylolpropane, trimethylolethane, and sugar alcohols (xylitol, sorbitol, etc.).

[0116] These polyols can be used alone or in combination of two or more.

[0117] The preferred component is a diol. From the perspective of the flexibility of the coating film, aliphatic diols are preferred, and ethylene glycol, 1,6-hexamethylenediol, 1,5-pentamethylenediol, 1,4-tetramethylenediol, 3-methyl-1,5-pentamethylenediol, and 2-methyl-1,3-trimethylenediol are even more preferred.

[0118] Examples of polycarboxylic acids include, for example, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, aromatic carboxylic acids with three or more nucleotides, and ester-forming derivatives of these polycarboxylic acids. Examples of aliphatic dicarboxylic acids include, for example, malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, octanoic acid, azelaic acid, sebacic acid, and dodecanoic acid. Examples of alicyclic dicarboxylic acids include, for example, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. Examples of aromatic dicarboxylic acids include, for example, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, and p-phenylene dicarboxylic acid. Examples of aromatic carboxylic acids with three or more nucleotides include, for example, trimellitic acid, trimellitic acid, and pyromellitic acid. Ester-forming derivatives of polycarboxylic acids are compounds derived from polycarboxylic acids that can form esters through reaction with polyols. Examples include carboxylates, carboxylic anhydrides, carboxylic halides, and carboxylic esters. These polycarboxylic acids can be used alone or in combination of two or more.

[0119] As a polycarboxylic acid, aliphatic dicarboxylic acids, aromatic dicarboxylic acids, and their ester-forming derivatives are preferred from the perspective of promoting adhesion to the substrate, adipic acid, isophthalic acid, terephthalic acid, and their ester-forming derivatives are more preferred, and adipic acid, isophthalic acid, and their ester-forming derivatives are even more preferred from the perspective of coating film flexibility, and isophthalic acid and its ester-forming derivatives are particularly preferred.

[0120] The polyester polyol (a2) preferably contains a structural component of at least one of isophthalic acid and an ester-forming derivative of isophthalic acid.

[0121] Examples of cyclic ester compounds include proprolactone, β-methyl-δ-valerolactone, and ε-caprolactone. These cyclic ester compounds can be used alone or in combination of two or more.

[0122] If the polyester polyol (a2) has too many hydroxyl groups, it tends to gel easily during the reaction. The polyester polyol (a2) preferably has 2 to 5 hydroxyl groups, more preferably 2 to 3, and from the perspective of excellent film flexibility and adhesion to the substrate, two hydroxyl groups are particularly preferred.

[0123] The number average molecular weight of the polyester polyol (a2) is preferably 300 or more, more preferably 350 or more, and even more preferably 400 or more. If the number average molecular weight of the polyester polyol (a2) is at or above the lower limit mentioned above, the flexibility and adhesion to the substrate of the coating film are improved. The number average molecular weight of the polyester polyol (a2) is preferably 10,000 or less, more preferably 5,000 or less, and even more preferably 2,500 or less. If the number average molecular weight of the polyester polyol (a2) is below the upper limit mentioned above, the curability is improved. The lower and upper limits of the number average molecular weight of the polyester polyol (a2) can be arbitrarily combined; for example, it is preferably 300 to 10,000, more preferably 350 to 5,000, and even more preferably 400 to 2,500.

[0124] There are no particular limitations on the method for manufacturing polyester polyol (a2). For example, polyester polyol (a2) can be obtained by adding a mixture of polyol and polycarboxylic acid and a catalyst to a reactor, for example, heating to 150–260°C, and removing water or methanol as a byproduct by distillation while carrying out an esterification or transesterification reaction. Alternatively, instead of a mixture of polyol and polycarboxylic acid, cyclic ester compounds can be used, or both a mixture of polyol and polycarboxylic acid and a cyclic ester compound can be used. Furthermore, instead of polycarboxylic acids, or ester-forming derivatives of polycarboxylic acids other than polycarboxylic acids, ester-forming derivatives of polycarboxylic acids can also be used.

[0125] [Hydroxy-containing (meth)acrylates (a3)]

[0126] The hydroxyl-containing (meth)acrylate (a3) ​​may have one, two, or more than three vinyl unsaturated groups.

[0127] Examples of hydroxyl-containing (meth)acrylates having one vinyl unsaturated group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 2-hydroxyethylacryloyl phosphate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, dipropylene glycol (meth)acrylate, fatty acid-modified glycidyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate. Examples of hydroxyl-containing (meth)acrylates having two vinyl unsaturated groups include glycerol di(meth)acrylate and 2-hydroxy-3-acryloyloxypropyl methacrylate. Examples of hydroxyl-containing (meth)acrylates having three or more vinyl unsaturated groups include pentaerythritol tri(meth)acrylate, caprolactone-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, caprolactone-modified dipentaerythritol penta(meth)acrylate, and ethylene oxide-modified dipentaerythritol penta(meth)acrylate.

[0128] These hydroxyl-containing (meth)acrylates (a3) ​​can be used alone or in combination of two or more.

[0129] Preferably, the hydroxyl-containing (meth)acrylates containing an vinyl unsaturated group are preferred. From the perspective of balancing hydrophilicity and lipophilicity, more preferably are hydroxyalkyl (meth)acrylates with 2 to 4 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, and polypropylene glycol mono(meth)acrylate. Further preferred are 2-hydroxyethyl (meth)acrylate and polyethylene glycol mono(meth)acrylate.

[0130] As a hydroxyl-containing (meth)acrylate (a3), it is preferable to include a compound containing a polyoxyalkylene chain. As an alkylene group of the polyoxyalkylene chain, it is preferably an alkylene group having 2 to 4 carbon atoms. As a compound containing a polyoxyalkylene chain in the hydroxyl-containing (meth)acrylate (a3), polyethylene glycol mono(meth)acrylate is particularly preferred.

[0131] The urethane (meth)acrylate (A2) can also be a reaction product obtained by further reacting other components besides polyisocyanates (a1), polyester polyols (a2), and hydroxyl-containing (meth)acrylates (a3). For example, polyethylene glycol, carboxyl-containing polyols, etc., can also be used as other components for the purpose of adjusting hydrophilicity. As a carboxyl-containing polyol, aliphatic polyhydroxycarboxylic acids are preferred, more preferably diol monocarboxylic acids or their neutralized salts with a molecular weight of 100 to 200, particularly preferably dimethylolbutyric acid or dimethylolpropionic acid, and even more preferably dimethylolbutyric acid. Part or all of the carboxyl groups derived from the carboxyl-containing polyol are neutralized by alkali, becoming a neutralized salt and thus hydrophilic.

[0132] When using carboxyl-containing polyols, the urethane (meth)acrylate (A2) has an acid value. The acid value of the urethane (meth)acrylate (A2) is preferably 0 mg KOH / g or higher, more preferably 2 mg KOH / g or higher, and even more preferably 4 mg KOH / g or higher. If the acid value of the urethane (meth)acrylate (A2) is above the lower limit of the above range, the emulsifying properties and emulsion stability are improved. The acid value of the urethane (meth)acrylate (A2) is preferably 50 mg KOH / g or lower, more preferably 20 mg KOH / g or lower, and even more preferably 10 mg KOH / g or lower. If the acid value of the urethane (meth)acrylate (A2) is below the upper limit of the above range, the coating film exhibits excellent flexibility.

[0133] The weight-average molecular weight of urethane (meth)acrylate (A2) is preferably 1,000 or more, more preferably 1,500 or more, and even more preferably 2,000 or more. If the weight-average molecular weight of urethane (meth)acrylate (A2) is at or above the lower limit mentioned above, the softness and adhesion of the coating film are improved. The weight-average molecular weight of urethane (meth)acrylate (A2) is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 20,000 or less. If the weight-average molecular weight of urethane (meth)acrylate (A2) is below the upper limit mentioned above, the emulsifying properties and emulsion stability are excellent. The lower and upper limits of the weight-average molecular weight of urethane (meth)acrylate (A2) can be combined arbitrarily, for example, preferably 1,000 to 100,000, more preferably 1,500 to 50,000, and even more preferably 2,000 to 20,000.

[0134] The viscosity of urethane (meth)acrylate (A2) at 60°C is preferably 500 mPa·s or more, more preferably 1,000 mPa·s or more, and even more preferably 2,000 mPa·s or more. The above-mentioned viscosity of urethane (meth)acrylate (A2) is preferably 1,000,000 mPa·s or less, more preferably 500,000 mPa·s or less, and even more preferably 100,000 mPa·s or less. If the viscosity of urethane (meth)acrylate (A2) is within the above range, the operability is excellent. The lower and upper limits of the viscosity of urethane (meth)acrylate (A2) can be arbitrarily combined, for example, preferably 500 to 1,000,000 mPa·s, more preferably 1,000 to 500,000 mPa·s, and even more preferably 2,000 to 100,000 mPa·s.

[0135] It should be noted that the viscosity was measured using an E-type viscometer.

[0136] The method for manufacturing urethane (meth)acrylate (A2) is not particularly limited. For example, the following methods (i) to (iii) can be cited. However, from the perspective of reaction stability and reduction of by-products, method (ii) is preferred.

[0137] (i) A method of reacting polyisocyanate (a1), polyester polyol (a2), and hydroxyl-containing (meth)acrylate (a3) ​​together or separately in a reactor.

[0138] (ii) A method for reacting a hydroxyl-containing (meth)acrylate (a3) ​​with a reaction product obtained by reacting a polyisocyanate (a1) with a polyester polyol (a2) in advance.

[0139] (iii) A method for reacting a polyester polyol (a2) with a reaction product obtained by reacting a polyisocyanate (a1) with a hydroxyl-containing (meth)acrylate (a3).

[0140] In methods (i) to (iii), the reaction is terminated when the residual isocyanate group content in the reaction system is less than 0.5% by weight, thereby obtaining urethane (meth)acrylate (A2).

[0141] In methods (i) to (iii), a catalyst is preferably used for the purpose of promoting the reaction.

[0142] Examples of such catalysts include organometallic compounds, metal salts, amine catalysts, bismuth-based catalysts, zirconium-based catalysts, and zinc 2-ethylhexanoate / zirconium tetraacetylacetonate. Examples of organometallic compounds include dibutyltin dilaurate, trimethyltin hydroxide, tetra-n-butyltin, and tin octanoate. Examples of metal salts include zinc octanoate, tin octanoate, cobalt naphthenate, stannous chloride, and stannous chloride. Examples of amine catalysts include triethylamine, benzyldiethylamine, 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]undecene, N,N,N',N'-tetramethyl-1,3-butanediamine, and N-ethylmorpholine. Examples of bismuth-based catalysts, besides bismuth nitrate, bismuth bromide, bismuth iodide, and bismuth sulfide, include organobismuth compounds such as dibutylbismuth dilaurate and dioctylbismuth dilaurate, bismuth salts of 2-ethylhexanoate, bismuth salts of naphthenates, bismuth isodecanate, bismuth neodecanoate, bismuth laurate, bismuth maleate, bismuth stearate, bismuth oleate, bismuth linoleate, bismuth acetate, bismuth bisnecidate, bismuth disalicylate, and bismuth digallate. Examples of zirconium-based catalysts include inorganic zirconium, organozirconium, and zirconium monomers. Among these, dibutyltin dilaurate and 1,8-diazabicyclo[5,4,0]undecene are preferred. It should be noted that these catalysts can be used alone or in combination with two or more.

[0143] In methods (i) to (iii), organic solvents that do not have functional groups that react with isocyanate groups can be used, such as esters like ethyl acetate and butyl acetate, ketones like methyl ethyl ketone and methyl isobutyl ketone, and aromatic solvents like toluene and xylene. From the viewpoint of reducing environmental impact, it is preferable to carry out the reaction in a solvent-free environment.

[0144] The reaction temperature can be set to 30–90℃, preferably 40–80℃.

[0145] The reaction time can be set to 2 to 10 hours, preferably 3 to 8 hours.

[0146] When using urethane (meth)acrylate (A2), the proportion of urethane (meth)acrylate (A2) in 100% by weight of the photopolymerizable compound (A) is preferably 5% by weight or more, more preferably 20% by weight or more, even more preferably 50% by weight or more, and particularly preferably 70% by weight or more. Furthermore, the proportion of urethane (meth)acrylate (A2) is preferably 100% by weight or less, more preferably 95% by weight or less, and even more preferably 90% by weight or less. If the proportion of urethane (meth)acrylate (A2) is within the above range, an excellent balance between emulsification stability and coating film softness is achieved. The lower and upper limits of the proportion of urethane (meth)acrylate (A2) can be arbitrarily combined; for example, it is preferably 5 to 100% by weight, more preferably 20 to 100% by weight, even more preferably 50 to 95% by weight, and particularly preferably 70 to 90% by weight.

[0147] The viscosity of the photopolymerizable compound (A) at 60°C can be set to 10 mPa·s or more, preferably 100 mPa·s or more, more preferably 200 mPa·s or more, and even more preferably 500 mPa·s or more. If the viscosity of the photopolymerizable compound (A) is above or below the lower limit of the above range, the necessity for reducing viscosity through forced emulsification increases. The viscosity of the photopolymerizable compound (A) at 60°C can be set to 500,000 mPa·s or less, preferably 200,000 mPa·s or less, more preferably 100,000 mPa·s or less, and even more preferably 50,000 mPa·s or less. If the viscosity of the photopolymerizable compound (A) is below or below the upper limit of the above range, shear force is easily imparted, and emulsification and emulsification stability are improved. The lower and upper limits of the viscosity of the above-mentioned photopolymerizable compound (A) can be arbitrarily combined, for example, it can be set to 10 to 500,000 mPa·s, preferably 100 to 200,000 mPa·s, more preferably 200 to 100,000 mPa·s, and even more preferably 500 to 50,000 mPa·s.

[0148] <Photopolymerization Initiator (C)>

[0149] From the perspective of promoting curing upon irradiation with active energy rays, the active energy ray curing composition of the present invention preferably further comprises a photopolymerization initiator (C). The photopolymerization initiator (C) may be used alone or in combination with two or more.

[0150] As a photopolymerization initiator (C), there are no particular limitations as long as it generates free radicals through the action of light. Examples include 2,2-dimethoxy-1,2-diphenylethane-1-one, 4-phenoxydichloroacetophenone, 4-tert-butyl-dichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-(4-isopropenylphenyl)-2-hydroxy-2-methylpropane-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropane-1-one, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)one, 1-hydroxycyclohexylphenylone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin dimethyl Ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3'-dimethyl-4-methoxybenzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, camphorquinone, dibenzocycloheptanone, 2-ethylanthraquinone, 4',4”- Diethyl-m-phenylene ketone, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, α-acyl oxime ester, acyl phosphine oxide, methyl phenyl glyoxylate, benzoyl, 9,10-phenanthrenequinone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl) ketone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenyl-phosphine oxide.

[0151] Preferably, the following are benzoyladium dimethyl ketal, 1-hydroxycyclohexylphenyl ketone, benzoin isopropyl ether, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and particularly preferably 1-hydroxycyclohexylphenyl ketone (manufactured by IGM Resins, "OMNIRAD 184"), 2-hydroxy-2-methyl-1-phenylpropane-1-one (manufactured by IGM Resins, "OMNIRAD 1173"), and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one (manufactured by IGM Resins, "OMNIRAD 184"). 907”, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by IGM Resins, “OMNIRAD TPO”).

[0152] From the perspective of further enhancing the function of the composition as an aqueous dispersion, a photopolymerization initiator (C) that is water-soluble or water-dispersible is preferably used. Examples of such photopolymerization initiators (C) include, for example, 2-(3-dimethylamino-2-hydroxypropoxy)-3,4-dimethyl-9H-thioxanthone-9-one methyl chloride (manufactured by Octel Chemicals, "Quantacure QTX"), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one (manufactured by IGM Resins, "OMNIRAD 2959"), "ESACURE DP250" manufactured by IGM Resins, and "FOM-03011" manufactured by Fujifilm and Koden Pharmaceutical Co., Ltd. Only one of these initiators may be used, or two or more may be used in combination.

[0153] Of particular preference is 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one (IGMresins, “OMNIRAD 2959”).

[0154] There is no particular limitation on the timing of adding the photopolymerization initiator (C). It can be forcibly emulsified together with the photopolymerizable compound (A) or added to the aqueous emulsion composition after forced emulsification. However, in the case of a non-water-soluble and solid photopolymerization initiator, from the perspective of coating appearance, it is preferable to forcibly emulsify together with the photopolymerizable compound (A).

[0155] The content of the photopolymerizable compound (A) in the active energy ray curable composition of the present invention is preferably 40% by weight or more, more preferably 50% by weight or more, further preferably 60% by weight or more, and particularly preferably 70% by weight or more, relative to 100% by weight of the total of the photopolymerizable compound (A) and the surfactant. If the content of the photopolymerizable compound (A) is at or above the aforementioned lower limit, the physical properties derived from the photopolymerizable compound (A) are easily fully utilized, and hardness and water resistance are improved. The content of the photopolymerizable compound (A) is preferably 99% by weight or less, more preferably 95% by weight or less, further preferably 90% by weight or less, particularly preferably 80% by weight or less, and especially preferably 78% by weight or less and 75% by weight or less. If the content of the photopolymerizable compound (A) is below the upper limit of the aforementioned range, the relative amount of surfactant required to emulsify the photopolymerizable compound (A) is less likely to be insufficient, and emulsification and emulsification stability are improved. The lower and upper limits of the content of the aforementioned photopolymerizable compound (A) can be arbitrarily combined, for example, preferably 40-99% by weight, more preferably 50-95% by weight, even more preferably 60-90% by weight, and particularly preferably 70-80% by weight.

[0156] The content of surfactant (B1) in the active energy ray curable composition is preferably 50% by weight or more, more preferably 60% by weight or more, further preferably 70% by weight or more, and particularly preferably 76% by weight or more, relative to the total mass of surfactants. If the content of surfactant (B1) is at or above the lower limit mentioned above, it results in an emulsion with small particle size and sharp particle size distribution, improving storage stability, especially freeze-thaw stability. The content of surfactant (B1) is preferably 99.5% by weight or less, more preferably 99% by weight or less, further preferably 95% by weight or less, and particularly preferably 90% by weight or less, relative to the total mass of surfactants. If the content of surfactant (B1) is below the upper limit mentioned above, the physical properties derived from the photopolymerizable compound (A) are easily fully utilized, improving the softness, adhesion, and water resistance of the coating film. The lower and upper limits of the content of surfactant (B1) relative to the total mass of surfactants can be arbitrarily combined; for example, it is preferably 50–99.5% by weight, more preferably 60–99% by weight, further preferably 70–95% by weight, and particularly preferably 76–90% by weight.

[0157] The content of surfactant (B1) in the active energy ray curable composition of the present invention is preferably 0.9% by weight or more, more preferably 4.0% by weight or more, further preferably 8.5% by weight or more, and particularly preferably 18% by weight or more, relative to 100% by weight of the total of the photopolymerizable compound (A) and the surfactant. If the content of surfactant (B1) is at or above the aforementioned lower limit, an emulsion with small particle size and sharp particle size distribution is formed, resulting in improved storage stability, particularly freeze-thaw stability. The content of surfactant (B1) is preferably 59.9% by weight or less, more preferably 49% by weight or less, further preferably 38.5% by weight or less, and particularly preferably 25% by weight or less, relative to 100% by weight of the total of the photopolymerizable compound (A) and the surfactant. If the content of surfactant (B1) is at or below the aforementioned upper limit, the physical properties derived from the photopolymerizable compound (A) are easily fully utilized, and the softness, adhesion, and water resistance of the coating film are improved. The content of the surfactant (B1) can be arbitrarily combined with the lower limit and upper limit of 100% by weight of the total of the photopolymerizable compound (A) and the surfactant, for example, preferably 0.9 to 59.9% by weight, more preferably 4.0 to 49% by weight, further preferably 8.5 to 38.5% by weight, and particularly preferably 18 to 25% by weight.

[0158] The content of surfactant (B2) in the active energy ray curable composition of the present invention is preferably 0.1% by weight or more, more preferably 1.0% by weight or more, further preferably 1.5% by weight or more, and particularly preferably 2.0% by weight or more, relative to 100% by weight of the total of photopolymerizable compound (A) and surfactant. If the content of surfactant (B2) is at or above the lower limit mentioned above, it is easier to form an emulsion with small particle size and sharp particle size distribution, thus improving storage stability, especially high-temperature storage stability. The content of surfactant (B2) is preferably 20% by weight or less, more preferably 10% by weight or less, further preferably 7.0% by weight or less, and particularly preferably 5.0% by weight or less. If the content of surfactant (B2) is at or below the upper limit mentioned above, the physical properties derived from photopolymerizable compound (A) are easily fully utilized, and the hardness, adhesion, and water resistance of the coating film are improved. The lower and upper limits of the content of the surfactant (B2) can be combined arbitrarily, for example, preferably 0.1 to 20% by weight, more preferably 1.0 to 10% by weight, even more preferably 1.5 to 7.0% by weight, and particularly preferably 2.0 to 5.0% by weight.

[0159] The amount of photopolymerization initiator (C) used is preferably 1 part by weight or more, more preferably 2 parts by weight or more, relative to the total 100 parts by weight of the photopolymerizable compound (A) and the surfactant. If the amount of photopolymerization initiator (C) used is at or above the aforementioned lower limit, the curing speed based on curing by irradiation with active energy rays such as ultraviolet light is sufficiently accelerated, and the target cured coating film is easily obtained. The amount of photopolymerization initiator (C) used is preferably 20 parts by weight or less, more preferably 16 parts by weight or less, and particularly preferably 10 parts by weight or less. Even if the amount of photopolymerization initiator (C) used exceeds the aforementioned upper limit, the curability will not improve, and by setting it below the aforementioned upper limit, the cured coating film is less prone to yellowing. The lower and upper limits of the amount of photopolymerization initiator (C) used can be combined arbitrarily, for example, preferably 1 to 20 parts by weight, more preferably 1 to 16 parts by weight, and particularly preferably 2 to 10 parts by weight.

[0160] The active energy ray curing composition of the present invention may further include any components other than surfactant, photopolymerizable compound (A) and photopolymerization initiator (C) without impairing the effects of the present invention.

[0161] Examples of ingredients include surface conditioners (leveling agents), UV absorbers, organic fillers, inorganic fillers, dyes and pigments, oils, plasticizers, waxes, desiccants, dispersants, wetting agents, gelling agents, stabilizers, defoamers, thixotropic agents, antioxidants, tackifiers, flame retardants, antistatic agents, fillers, reinforcing agents, matting agents, crosslinking agents, silica, water-dispersible silica, preservatives, fungicides, freeze-thaw stabilizers (ethylene glycol, etc.), film-forming agents (butyl cellosolve, etc.), and polar solvents used to assist in water dispersion (N-methylpyrrolidone, 3-methoxy-N,N-dimethylpropionamide, etc.). These can be used alone or in combination of two or more.

[0162] These components can be used in conjunction with surfactant (B1) for emulsification (stirring), or added to emulsified active energy ray-cured compositions.

[0163] [Aqueous Emulsion Composition]

[0164] The aqueous emulsion composition of the present invention contains the above-described active energy ray-curable composition of the present invention. That is, the aqueous emulsion composition of the present invention is an emulsion composition obtained by emulsifying the active energy ray-curable composition of the present invention in an aqueous solvent.

[0165] The aqueous emulsion composition of the present invention preferably contains water as an aqueous solvent. It should be noted that the aqueous solvent is not limited to water, but can also be a solvent prepared by mixing water with a lower alcohol having 1 to 5 carbon atoms, within a range that does not impair the emulsified state.

[0166] The amount of aqueous solvent used relative to 100% by weight of the total mass of the aqueous emulsion composition is preferably 5% by weight or more, more preferably 10% by weight or more, and even more preferably 20% by weight or more. If the amount of aqueous solvent used is above the lower limit mentioned above, phase inversion is more likely to occur, and the viscosity is more likely to become sufficiently low. The amount of aqueous solvent used is preferably 80% by weight or less, more preferably 70% by weight or less, and even more preferably 60% by weight or less. If the amount of aqueous solvent used is below the upper limit mentioned above, the drying load during coating is reduced. The lower and upper limits of the amount of aqueous solvent used can be combined arbitrarily, for example, preferably 5 to 80% by weight, more preferably 10 to 70% by weight, and even more preferably 20 to 60% by weight.

[0167] The concentration of non-volatile components in the aqueous emulsion composition of the present invention is preferably 5% by weight or more, more preferably 10% by weight or more, and even more preferably 20% by weight or more, relative to 100% by weight of the total mass of the aqueous emulsion composition. If the concentration of non-volatile components is at or above the aforementioned lower limit, pinholes are less likely to occur relative to the substrate during coating, and the drying load is reduced. The aforementioned concentration of non-volatile components is preferably 80% by weight or less, more preferably 70% by weight or less, and even more preferably 60% by weight or less. If the concentration of non-volatile components is at or below the aforementioned upper limit, the flowability becomes good, and coating becomes easier. The aforementioned lower and upper limits of the non-volatile component concentration can be arbitrarily combined; from the perspective of coating workability, for example, 5 to 80% by weight is preferred, more preferably 10 to 70% by weight, and even more preferably 20 to 60% by weight.

[0168] The average core particle size of the aqueous emulsion composition of the present invention is preferably 10 nm or more, more preferably 50 nm or more, further preferably 60 nm or more, and particularly preferably 70 nm or more. If the average core particle size is above the aforementioned lower limit, the emulsion viscosity is sufficiently reduced, resulting in excellent workability. The aforementioned average core particle size is preferably 1,000 nm or less, more preferably 500 nm or less, further preferably 200 nm or less, and particularly preferably 150 nm or less. If the average core particle size is below the aforementioned upper limit, aggregation is less likely to occur, and emulsion stability is improved. The aforementioned lower and upper limits of the average core particle size can be arbitrarily combined; for example, it is preferably 10–1,000 nm, more preferably 50–500 nm, further preferably 60–200 nm, and particularly preferably 70–150 nm.

[0169] It should be noted that the average nucleus size refers to the average value based on the volumetric standard of scattering intensity distribution. The nucleus size was determined using a laser scattering / diffraction apparatus (manufactured by Horiba Corporation; LA950V2).

[0170] The viscosity of the aqueous emulsion composition of the present invention at 25°C is preferably 5 mPa·s or more, more preferably 10 mPa·s or more, and even more preferably 20 mPa·s or more. If the viscosity is above the lower limit, film thickness control becomes easier. The viscosity is preferably 20,000 mPa·s or less, more preferably 10,000 mPa·s or less, and even more preferably 5,000 mPa·s or less. If the viscosity is below the upper limit, it is easier to process, and coating workability becomes good. The lower and upper limits of the viscosity can be combined arbitrarily; for example, 5 to 20,000 mPa·s is preferred, more preferably 10 to 10,000 mPa·s, and even more preferably 20 to 5,000 mPa·s.

[0171] It should be noted that the above viscosity was measured using an E-type viscometer (100 rpm).

[0172] The aqueous emulsion composition of the present invention may also be combined with aqueous dispersions or aqueous solutions such as acrylic emulsions and polyurethane dispersions, which are different from the aqueous emulsion composition of the present invention.

[0173] <Methods for manufacturing emulsions>

[0174] Next, the method for manufacturing the aqueous emulsion composition of the present invention will be described.

[0175] The aqueous emulsion composition of the present invention can be obtained, for example, by using two or more surfactants, at least one of which is a surfactant (B1), to forcibly emulsify the photopolymerizable compound (A) in an aqueous solvent via a phase inversion emulsification method. "Forced emulsification" is a method of emulsifying and dispersing a water-insoluble compound that does not possess emulsifying power itself in an aqueous solvent by using surfactants and shear force.

[0176] To reduce the viscosity during phase inversion emulsification, it is well known to pre-add organic solvents such as methyl ethyl ketone and acetone, and then desolventize under reduced pressure after emulsification. The system of this invention can also employ such a method. However, considering VOC reduction, a solvent-free method for phase inversion emulsification is preferred.

[0177] As a specific method, for example, after adding a photopolymerizable compound (A) and two or more surfactants containing a surfactant (B1) to a beaker, ion-exchanged water is gradually added while stirring at 40–70°C using a mixer such as a high-speed disperser, a double-cylinder homogenizer, an ultrasonic homogenizer, a blender, or a mixer. When the added ion-exchanged water exceeds a certain amount, a phase inversion occurs from water droplets in oil (W / O) to oil droplets in water (O / W). By applying strong stirring force during the phase inversion, a small-particle-size and uniform emulsion composition is obtained. Then, stirring continues until the mixture returns to room temperature. Surface conditioners, defoamers, preservatives, antifungal agents, photopolymerization initiators, etc., are added as needed and mixed to obtain the target aqueous emulsion composition.

[0178] The aqueous emulsion composition of the present invention, for example, is an emulsion composition with a concentration of 50% by weight, and no precipitation is observed even after standing at room temperature (23°C) for 1 to 2 months, and it can maintain a uniform dispersion state.

[0179] The coating film formed from the aqueous emulsion composition under the following conditions has a pencil hardness of 2H or higher, more preferably 3H or higher, as determined by the method of JIS K 5600-5-4 under a 1 kg load. If the pencil hardness of the above coating film is above the lower limit value, it is highly useful in various applications such as protective coatings and hard coatings.

[0180] <Coating film formation conditions>

[0181] The aqueous emulsion composition was applied to the surface of a 125 μm thick easily bondable polyethylene terephthalate film using a bar coater. After drying at 100°C for 2 minutes, a high-pressure mercury lamp was used to apply the emulsion composition at a cumulative light intensity of 450 mJ / cm². 2 It is cured by ultraviolet irradiation to form a coating with a thickness of 10μm.

[0182] It should be noted that "easy-to-adhere polyethylene terephthalate film" refers to a polyethylene terephthalate film on which one or both sides have been surface-modified using a primer such as water-based urethane resin, water-based polyester resin, or water-based acrylic resin. Examples of products include those manufactured by Toyobo Co., Ltd.: COSMOSHINE A4300 and COSMOSHINE A4360.

[0183] As explained above, the active energy ray-curable composition of the present invention contains two or more surfactants, at least one of which is a surfactant (B1). By forcibly emulsifying the active energy ray-curable composition using two or more surfactants containing surfactant (B1), a small-particle-size and uniform aqueous emulsion composition can be obtained. Therefore, the obtained aqueous emulsion composition exhibits excellent storage stability at room temperature and high temperature. In addition, it also exhibits excellent freeze-thaw stability, with minimal particle size change even after repeated freeze-thaw cycles. Furthermore, the coating film formed by applying the aqueous emulsion composition of the present invention shows excellent adhesion to the substrate and excellent water resistance.

[0184] In particular, using an anionic surfactant (B2) results in electrostatic repulsion between particles, while using a nonionic urethane acrylate surfactant (B1) results in stereorepulsion. Furthermore, combining them enhances particle repulsion due to their synergistic effect, resulting in a very small and uniform aqueous emulsion composition compared to using each surfactant alone.

[0185] Furthermore, if a photopolymerizable compound (A) containing urethane (meth)acrylate (A2) is used, a coating film with excellent flexibility can be easily formed. Aqueous emulsion compositions capable of forming highly flexible coating films are useful in applications such as coatings and anchoring coatings. On the other hand, aqueous emulsion compositions capable of forming highly hard coating films are useful in applications such as protective coatings and hard coatings. Additionally, a balance between flexibility and hardness can be achieved by mixing aqueous emulsion compositions capable of forming highly flexible coating films and those capable of forming highly hard coating films.

[0186] The uses of the aqueous emulsion composition of the present invention are not particularly limited, and it is very useful as a coating forming material for various applications such as coatings, protective coatings, anchoring coatings, hard coatings, inks, magnetic powder coating adhesives, sandblasting films, adhesives, bonding agents, bonding agents, and printing plates.

[0187] <Coating Composition>

[0188] The aqueous emulsion composition of the present invention can be used, for example, as a coating agent composition (curing resin composition) for forming a coating film on various substrates, and is useful as a topcoat, anchoring agent, etc. For example, the aqueous emulsion composition of the present invention can be coated on a substrate, dried, and then irradiated with active energy rays to cure the coating film, thereby forming a cured coating film on the substrate.

[0189] Examples of coating methods include wet coating methods such as spraying, rinsing, dipping, rolling, rotating, and screen printing.

[0190] The drying temperature can be set to 40–120°C, preferably 50–100°C.

[0191] The drying time can be set to 1 to 20 minutes, preferably 2 to 10 minutes.

[0192] Examples of active energy rays include, in addition to far-ultraviolet, ultraviolet, near-ultraviolet, and infrared rays, electromagnetic waves such as X-rays and gamma rays, electron beams, proton beams, and neutral rays. Among these, ultraviolet irradiation is preferred considering factors such as curing speed, ease of obtaining irradiation equipment, and cost. It should be noted that, under electron beam irradiation, the coating composition of the present invention can be cured even without the use of a photopolymerization initiator (C).

[0193] As a method for curing a coating by ultraviolet irradiation, examples include using high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, chemical lamps, and LED lamps that emit light in the wavelength range of 150–450 nm. The ultraviolet irradiation dose only needs to be set to 100–3000 mJ / cm². 2 Left or right is sufficient. To ensure proper curing, heating can also be applied after UV irradiation as needed.

[0194] Examples of substrates for forming a cured coating include molded products (films, sheets, cups, etc.) made of resins such as polyolefins (polyethylene, polypropylene, polycyclopentadiene, etc.), polycarbonate, polyester, ABS resin, and acrylic resin, as well as metals and glass.

[0195] For example, a laminate can be formed having at least one layer formed by the active energy ray curable composition of the present invention. The laminate may also have other layers besides the layer formed by the active energy ray curable composition of the present invention.

[0196] The present invention will now be specifically described through examples, but the present invention is not limited to the following description. It should be noted that, in the examples, "parts" and "%" refer to weight.

[0197] <Product name and structure of photopolymerizable compound (A)>

[0198] • (A1-0): Phenoxy diethylene glycol acrylate (Product name: LIGHT ACRYLATE P2H-A; manufactured by Kyoei Chemical Co., Ltd.)

[0199] • (A1-1): Acrylic acid adduct of dipentaerythritol with a hydroxyl value of 51 mg KOH / g (Product name: KAYARAD DPHA; manufactured by Nippon Kayaku Co., Ltd.)

[0200] • (A1-2): Acrylic acid adduct of dipentaerythritol with a hydroxyl value of 33 mg KOH / g (Product name: ARONIX M-402; manufactured by Toa Synthetic Co., Ltd.)

[0201] • (A1-3): Acrylic acid adduct of dipentaerythritol with a hydroxyl value below 30 mg KOH / g (Product name: ARONIX M-406; manufactured by Toa Synthetic Co., Ltd.)

[0202] • (A1-4): Acrylic acid adduct of dipentaerythritol with a hydroxyl value of 99 mg KOH / g (Product name: KAYARAD FM-700; manufactured by Nippon Kayaku Co., Ltd.)

[0203] • (A1-5): Acrylic acid adduct of dipentaerythritol with a hydroxyl value of 62 mg KOH / g (Product name: KAYARAD DPHA; manufactured by Nippon Kayaku Co., Ltd.)

[0204] • (A1-6): Acrylic acid adduct of pentaerythritol with a hydroxyl value of 120 (Product name: VISCOAT#300; manufactured by Osaka Organic Chemical Industry Co., Ltd.)

[0205] • (A1-7): Pentaerythritol tetraacrylate (Product name: ARONIX M-450; manufactured by Toa Synthetic Co., Ltd.)

[0206] • (A1-8): Trimethylolpropane triacrylate (Product name: ARONIX M-309; manufactured by Toa Synthetic Co., Ltd.)

[0207] • (A1-9): Ethylene oxide-modified di and triacrylates of isocyanuric acid (Product name: ARONIX M-315; manufactured by Toa Synthetic Co., Ltd.)

[0208] • (A1-10): Ethylene oxide-modified di and triacrylates of isocyanurate (Product name: ARONIX M-313; manufactured by Toa Synthetic Co., Ltd.)

[0209] • (A1-11): Glyceryl triacrylate (Product name: ARONIX M-930; manufactured by Toa Synthetic Co., Ltd.)

[0210] • (A1-12): Glyceryl diacrylate and triacrylate (Product name: ARONIX M-920; manufactured by Toa Synthetic Co., Ltd.)

[0211] • (A1-13): 1,6-Hexanediol diacrylate (Product name: Light Acrylate 1.6HX-A; manufactured by Kyoei Chemical Co., Ltd.)

[0212] • (A1-14): Acryloylmorpholine (Product name: ACMO; manufactured by KJ Chemical Company)

[0213] • (A1-15): Isoborneol acrylate (Product name: IBXA; manufactured by Osaka Organic Chemical Industry Co., Ltd.)

[0214] • (A2-1): A urethane acrylate oligomer with 10 functional groups and a weight-average molecular weight of 2,000 (product name: UV-1700B; manufactured by Mitsubishi Chemical Corporation).

[0215] • (A2-2): A urethane acrylate oligomer with 6 functional groups and a weight-average molecular weight of 1,400 (product name: UV-7600B; manufactured by Mitsubishi Chemical Corporation).

[0216] • (A2-3): A urethane acrylate oligomer with 2 functional groups and a weight-average molecular weight of 13,000 (product name: UV-3300B; manufactured by Mitsubishi Chemical Corporation).

[0217] • (A2-4): A urethane acrylate oligomer with 3 functional groups and a weight-average molecular weight of 3,500 (product name: UV-7510B; manufactured by Mitsubishi Chemical Corporation).

[0218] <Surfactant (B2)>

[0219] • (B2-1): Polyoxyalkylene ether ammonium sulfate (product name: LATEMUL PD-104; manufactured by Kao Corporation); conforms to the above general formula (1).

[0220] • (B2-2): Amino ion RE2000L (manufactured by Japan Emulsifier Co., Ltd.)

[0221] (B2-3): ADEKA REASOAP SR-10 (Made by ADEKA Corporation)

[0222] • (B2-4): Sodium methacryloyloxy polyoxypropylene sulfate (product name: ELEMINOL RS-3000; manufactured by Sanyo Chemical Co., Ltd.); conforms to the above general formula (1).

[0223] • (B2-5): Polyoxyalkylene ether (product name LATEMUL PD-420; manufactured by Kao Corporation)

[0224] • (B2-6): Polyoxyalkylene ether (product name LATEMUL PD-450; manufactured by Kao Corporation)

[0225] <Photopolymerization Initiator (C)>

[0226] • (C-1): 2-Hydroxy-2-methyl-1-phenylpropane-1-one (Product name: OMNIRAD 1173; manufactured by IGM Resins)

[0227] • (C-2): 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one (Product name: OMNIRAD 2959; manufactured by IGM Resins)

[0228] • (C-3): 1-Hydroxycyclohexylphenyl ketone (Product name: OMNIRAD 184; manufactured by IGM Resins)

[0229] Prior to the examples, the following urethane acrylate as urethane (meth) acrylate (A2) and urethane acrylate as surfactant (B1) were prepared respectively.

[0230] <Preparation of urethane (meth)acrylate (A2)>

[0231] [Manufacturing of urethane acrylate (A2-5)]

[0232] In a flask equipped with an internal thermometer, stirrer, and cooling tube, add 123 g (0.554 mol) of isophorone diisocyanate, 555 g (0.277 mol) of a polyester polyol compound [linear structure, difunctional; polycarboxylic acid component: adipic acid; polyol component: ethylene glycol, 1,4-tetramethylene glycol; hydroxyl value 56.0 mg KOH / g; number average molecular weight calculated based on hydroxyl value 2,004], 1.00 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst, and react at 60 °C. At a point when the residual isocyanate group content is below 3.4%, 322 g (0.568 mol) of polyethylene glycol monoacrylate [hydroxyl value: 99.0 mg KOH / g, weight-average molecular weight calculated based on hydroxyl value: 567] is added, and the reaction is carried out at 60 °C. The reaction is stopped when the residual isocyanate group content is below 0.1%, to obtain a composition containing urethane acrylate (A2-5) (resin component concentration: 100%, weight-average molecular weight: 13,100, viscosity: 14,500 mPa·s / 60 °C).

[0233] [Manufacturing of urethane acrylate (A2-6)]

[0234] In a flask equipped with an internal thermometer, a stirrer, and a cooling tube, add 207 g (0.930 mol) of isophorone diisocyanate, 431 g (0.465 mol) of a polyester polyol compound [linear structure, difunctional; polycarboxylic acid components: adipic acid, isophthalic acid; polyol component: 1,6-hexamethylene glycol; hydroxyl value 121 mg KOH / g; number average molecular weight calculated based on hydroxyl value 927], 0.4 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst, and react at 60 °C. At a point when the residual isocyanate group content is below 6.1%, 319 g (0.581 mol) of polyethylene glycol monoacrylate [hydroxyl value: 102 mg KOH / g, weight-average molecular weight calculated based on hydroxyl value: 548] and 43.2 g (0.372 mol) of 2-hydroxyethyl acrylate are added. The reaction is carried out at 60 °C, and the reaction is stopped when the residual isocyanate group content is below 0.1%, to obtain a composition containing urethane acrylate (A2-6) (resin component concentration: 100%, weight-average molecular weight: 6,700, viscosity: 7,500 mPa·s / 60 °C).

[0235] [Manufacturing of urethane acrylate (A2-7)]

[0236] In a flask equipped with an internal thermometer, stirrer, and cooling tube, 180 g (0.812 mol) of isophorone diisocyanate, 733 g (0.406 mol) of a polyester polyol compound [linear difunctional; polycarboxylic acid components: adipic acid, isophthalic acid; polyol component: 3-methyl-1,5-pentamethylenediol; hydroxyl value 62.1 mg KOH / g; number-average molecular weight calculated based on hydroxyl value 1810], and 0.1 g of dibutyltin dilaurate as a reaction catalyst were added, and the reaction was carried out at 70 °C. When the residual isocyanate group content was below 3.7%, 18.0 g (0.122 mol) of dimethylolbutyric acid was added, and the reaction was carried out at 95 °C. The mixture was cooled to 70°C when the residual isocyanate group content was below 2.6%, and 68.3 g (0.588 mol) of 2-hydroxyethyl acrylate and 0.4 g of 2,6-di-tert-butylcresol as a polymerization inhibitor were added. The reaction was carried out at 70°C, and the reaction was stopped when the residual isocyanate group content was below 0.1%, to obtain a composition containing urethane acrylate (A2-7) (resin concentration: 100%, weight average molecular weight: 11,000, viscosity: 260,000 mPa·s / 60°C, acid value: 6.8 mg KOH / g).

[0237] [Manufacturing of urethane acrylate (A2-8)]

[0238] In a flask equipped with an internal thermometer, stirrer, and cooling tube, add 130 g (0.670 mol) of 1,3-bis(isocyanate methyl)cyclohexane (equivalent to hydrogenated dimethyl phthalate diisocyanate), 599 g (0.335 mol) of a polyester polyol compound (linear difunctional structure; polycarboxylic acid components: adipic acid, isophthalic acid; polyol component: 3-methyl-1,5-pentamethylenediol; hydroxyl value 62.8 mg KOH / g; number average molecular weight calculated based on hydroxyl value 1790), 200 g of phenoxydiethylene glycol acrylate (Al-O) as a reactive diluent, 0.4 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst, and react at 70 °C. At a point where the residual isocyanate group content is below 3.0%, 14.9 g (0.100 mol) of dimethylolbutyric acid is added, and the reaction is carried out at 80 °C. At a point where the residual isocyanate group content is below 2.1%, the mixture is cooled to 60 °C, and 56.4 g (0.486 mol) of 2-hydroxyethyl acrylate is added. The reaction is carried out at 60 °C, and the reaction is terminated at a point where the residual isocyanate group content is below 0.1%, yielding a composition containing 80 wt% urethane acrylate (A2-8) (weight average molecular weight: 14,000, acid value: 7.1 mg KOH / g) and 20 wt% phenoxydiethylene glycol acrylate (A1-0) (viscosity: 31,000 mPa·s / 60 °C).

[0239] [Manufacturing of urethane acrylate (A2-9)]

[0240] In a flask equipped with an internal thermometer, stirrer, and cooling tube, add 130 g (0.668 mol) of 1,3-bis(isocyanate methyl)cyclohexane (equivalent to hydrogenated dimethyl phthalate diisocyanate), 597 g (0.334 mol) of a polyester polyol compound (linear difunctional structure; polycarboxylic acid components: adipic acid, isophthalic acid; polyol component: 3-methyl-1,5-pentamethylenediol; hydroxyl value 62.8 mg KOH / g; number average molecular weight calculated based on hydroxyl value 1790), 200 g of phenoxydiethylene glycol acrylate (Al-O) as a reactive diluent, 0.4 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst, and carry out the reaction at 70 °C. At a point where the residual isocyanate group content is below 3.0%, 9.9 g (0.067 mol) of dimethylolbutyric acid is added, and the reaction is carried out at 80 °C. At a point where the residual isocyanate group content is below 2.4%, the mixture is cooled to 60 °C, and 64.0 g (0.551 mol) of 2-hydroxyethyl acrylate is added. The reaction is carried out at 60 °C, and the reaction is stopped at a point where the residual isocyanate group content is below 0.1%, yielding a composition containing 80 wt% urethane acrylate (A2-9) (weight-average molecular weight: 12,000, acid value: 4.7 mg KOH / g) and 20 wt% phenoxydiethylene glycol acrylate (A1-0) (viscosity: 16,000 mPa·s / 60 °C).

[0241] <Preparation of Surfactant (B1)>

[0242] [Manufacturing of urethane acrylate (B1-1)]

[0243] In a flask equipped with an internal thermometer, a stirrer, and a cooling tube, 96.1 g (0.432 mol) of isophorone diisocyanate, 606 g (0.519 mol) of the acrylic adduct of pentaerythritol [hydroxyl value: 48.0 mg KOH / g], 1.65 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst were added, and the reaction was carried out at 70 °C. The mixture was cooled to 60°C when the residual isocyanate group content was below 2.1%, and 298 g (0.302 mol) of polyethylene glycol [hydroxyl value: 114.0 mg KOH / g, weight-average molecular weight calculated based on hydroxyl value: 984] was added. The reaction was carried out at 60°C, and the reaction was stopped when the residual isocyanate group content was below 0.1%, to obtain a composition containing urethane acrylate (B1-1) (resin component concentration: 100%, weight-average molecular weight: 3,500, viscosity: 1,200 mPa·s / 60°C).

[0244] [Preparation of urethane acrylate compounds (B1-2)]

[0245] In a flask equipped with an internal thermometer, a stirrer, and a cooling tube, 77.5 g (0.461 mol) of hexamethylene diisocyanate, 608 g (0.553 mol) of the acrylic acid adduct of pentaerythritol [hydroxyl value: 51 mg KOH / g], 1.65 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst were added, and the reaction was carried out at 70 °C. The mixture was cooled to 60°C when the residual isocyanate group content was below 2.3%, and 315 g (0.332 mol) of polyethylene glycol [hydroxyl value: 115 mg KOH / g, weight-average molecular weight calculated based on hydroxyl value: 976] was added. The reaction was carried out at 60°C, and the reaction was stopped when the residual isocyanate group content was below 0.1%, to obtain a composition containing urethane acrylate compound (B1-2) (resin component concentration: 100%, weight-average molecular weight: 3,600, viscosity: 710 mPa·s / 60°C).

[0246] [Manufacturing of urethane acrylates (B1-3)]

[0247] In a flask equipped with an internal thermometer, a stirrer, and a cooling tube, 317 g (0.548 mol) of a trimer compound of hexamethylene diisocyanate with an isocyanurate backbone (isocyanate group content 21.8%), 127 g (1.07 mol) of 2-hydroxyethyl acrylate, 1.00 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst were added, and the reaction was carried out at 60 °C. At a point when the residual isocyanate group content is below 5.2%, 556 g (0.565 mol) of polyethylene glycol [hydroxyl value: 114.0 mg KOH / g, weight-average molecular weight calculated based on hydroxyl value: 984] is added, and the reaction is carried out at 60 °C. The reaction is stopped when the residual isocyanate group content is below 0.1%, to obtain a composition containing urethane acrylate (B1-3) (resin component concentration: 100%, weight-average molecular weight: 6,100, viscosity: 1,500 mPa·s / 60 °C).

[0248] [Manufacturing of urethane acrylates (B1-4)]

[0249] 301 g (0.561 mol) of a biuret-type polyisocyanate compound (isocyanate group content 23.5%) containing hexamethylene diisocyanate, 130 g (1.12 mol) of 2-hydroxyethyl acrylate, 1.00 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst were added to a flask equipped with an internal thermometer, a stirrer, and a cooling tube. The reaction was carried out at 60 °C. At a point when the residual isocyanate group content is below 5.5%, 569 g (0.578 mol) of polyethylene glycol [hydroxyl value: 114.0 mg KOH / g, weight-average molecular weight calculated based on hydroxyl value: 984] is added, and the reaction is carried out at 60 °C. The reaction is stopped when the residual isocyanate group content is below 0.1%, to obtain a composition containing urethane acrylate (B1-4) (resin component concentration: 100%, weight-average molecular weight: 6,100, viscosity: 1,400 mPa·s / 60 °C).

[0250] [Manufacturing of urethane acrylates (B1-5)]

[0251] In a flask equipped with an internal thermometer, a stirrer, and a cooling tube, 324 g (0.542 mol) of a trimer compound of hexamethylene diisocyanate with an isocyanurate backbone (isocyanate group content 21.1%), 126 g (1.09 mol) of 2-hydroxyethyl acrylate, 1.00 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst were added, and the reaction was carried out at 60 °C. At a point when the residual isocyanate group content is below 5.1%, 550 g (0.559 mol) of polyethylene glycol [hydroxyl value: 114.0 mg KOH / g, weight-average molecular weight calculated based on hydroxyl value: 984] is added, and the reaction is carried out at 60 °C. The reaction is stopped when the residual isocyanate group content is below 0.1%, to obtain a composition containing urethane acrylate (B1-5) (resin component concentration: 100%, weight-average molecular weight: 13,000, viscosity: 1,700 mPa·s / 60 °C).

[0252] [Manufacturing of urethane acrylates (B1-6)]

[0253] 529 g (0.378 mol) of an adduct-type polyisocyanate compound of hexamethylene diisocyanate (isocyanate group content 9.0%), 87.7 g (0.756 mol) of 2-hydroxyethyl acrylate, 1.00 g of 2,6-di-tert-butylcresol as a polymerization inhibitor, and 0.1 g of dibutyltin dilaurate as a reaction catalyst were added to a flask equipped with an internal thermometer, a stirrer, and a cooling tube, and the reaction was carried out at 60 °C. At a point when the residual isocyanate group content is below 2.6%, 383 g (0.389 mol) of polyethylene glycol [hydroxyl value: 114.0 mg KOH / g, weight-average molecular weight calculated based on hydroxyl value: 984] is added, and the reaction is carried out at 60 °C. The reaction is stopped when the residual isocyanate group content is below 0.1%, to obtain a composition containing urethane acrylate (B1-6) (resin component concentration: 100%, weight-average molecular weight: 8,600, viscosity: 2,700 mPa·s / 60 °C).

[0254] <Preparation of Dispersion>

[0255] [Example A1]

[0256] In a cylindrical container, add the dipentaerythritol acrylic adduct (hydroxyl value 51 mg KOH / g, product name: KAYARAD DPHA; manufactured by Nippon Kayaku Co., Ltd.) (A1-1) and the above-mentioned carbamate acrylate compound (B1-1). After heating at 60°C, add polyoxyalkylene ether ammonium sulfate (product name: LATEMUL PD-104; manufactured by Kao Corporation) (B2-1). While stirring with a dispenser, add purified water at 80°C. Finally, while restoring to room temperature, stir to prepare an aqueous emulsion composition (50% non-volatile components). The formulation is set as shown in Table 1.

[0257] [Examples A2-A43, Comparative Examples A1-A6]

[0258] Following the formulation shown in Table 1, an aqueous emulsion composition (50-60% non-volatile components) was prepared in the same manner as in Example A1, and evaluated as follows. It should be noted that, for Example A8, the composition was prepared by stirring with a homogenizer instead of a dispenser.

[0259] <Evaluation>

[0260] The obtained aqueous emulsion compositions were evaluated as follows. The results are shown in Tables 1–7.

[0261] [Viscosity at 25℃]

[0262] For the aqueous emulsion compositions with 50-60% non-volatile components prepared in Examples A1-A43 and Comparative Examples A1-A6, the viscosity at 25°C was measured using an E-type viscometer (100 rpm).

[0263] [Average nucleus size]

[0264] For the aqueous emulsion compositions with 50-60% nonvolatile components prepared in Examples A1-A43 and Comparative Examples A1-A6, the average nucleus size (volume-based average diameter) was determined using a laser scattering / diffraction apparatus (Horiba Manufacturing Co., Ltd.; LA950V2).

[0265] [Defoaming properties]

[0266] For the aqueous emulsion compositions with 50-60% non-volatile components prepared in Examples A1-A43 and Comparative Examples A1-A6, the defoaming properties after standing for 3 days after preparation were evaluated by visual inspection as follows.

[0267] (Evaluation Criteria)

[0268] 1…The foam has almost completely disappeared.

[0269] 2…The bubbles did not disappear.

[0270] [Storage stability at room temperature]

[0271] The aqueous emulsion compositions with 50-60% non-volatile components obtained in Examples A1-A43 and Comparative Examples A1-A6 were added to a covered container, and the number of days that they could be stored at room temperature (23°C) was evaluated by visual inspection as follows.

[0272] (Evaluation Criteria)

[0273] No separation or precipitation for more than 1-2 months

[0274] No separation or precipitation occurred within 2 weeks to less than 2 months.

[0275] No separation or precipitation for more than 3 days but less than 1 week

[0276] Separation and precipitation within 4…2 days

[0277] [Storage stability at 60℃]

[0278] Aqueous emulsion compositions containing 50-60% non-volatile components obtained in Examples A2, A3, A5-8, A11, A12, A14, A15, A24, A34, A42, and Comparative Examples A5 and A6 were added to a covered container and allowed to stand at 60°C for 1 month. The appearance of the solution was observed and the particle size was measured. The evaluation was carried out according to the following criteria.

[0279] 1: No increase in particle size

[0280] 2: The particle size is slightly increased (the increase is less than 100 nm).

[0281] 3: Increased particle size (more than 100 nm).

[0282] 4: Separation of precipitates or particles with a diameter exceeding 1000 nm

[0283] [Freeze-thaw stability]

[0284] Aqueous emulsion compositions containing 50-60% non-volatile components, obtained in Examples A2, A3, A5-A8, A11, A12, A14, A15, A24, A34, A42, and Comparative Examples A5 and A6, were added to a covered container. The process of "freezing at -30°C overnight and thawing at room temperature the next day" was repeated for 5 cycles. The appearance of the solution was observed and the particle size was measured. The evaluation was carried out according to the following criteria.

[0285] 1: No increase in particle size

[0286] 2: The particle size is slightly increased (the increase is less than 100 nm).

[0287] 3: Increased particle size (more than 100 nm).

[0288] 4: Separation of precipitates or particles with a diameter exceeding 1000 nm

[0289] <Preparation of Evaluation Coating Samples>

[0290] 100 parts of an aqueous emulsion composition containing 50% of the resin component obtained in Examples A2, A3, and A6 were mixed with a photopolymerization initiator and surface conditioner (product name: TegoWet260; manufactured by Evonik Japan) as shown in Table 7. The mixture was applied using a rod coater to easily bondable polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd.; COSMOSHINE A4300, thickness 125 μm), acrylonitrile-butadiene-styrene copolymer resin (ABS) white board (manufactured by Nippon Testpanel Co., Ltd.), or polycarbonate (PC) board (manufactured by Nippon Testpanel Co., Ltd.). After drying at 100°C for 2 minutes, the mixture was then subjected to a high-pressure mercury lamp with a cumulative light intensity of 450 mJ / cm². 2 The aqueous emulsion composition was cured by ultraviolet irradiation to prepare an evaluation coating sample with a film thickness of 10 μm. The obtained evaluation coating sample was then used for the following evaluation.

[0291] [Coating Appearance]

[0292] Observe the surface condition of the obtained cured coating and evaluate it according to the following criteria.

[0293] 1…No shrinkage cavities were observed.

[0294] 2…No shrinkage cavities were observed.

[0295] 3…Observed coating defects such as pinholes and bumps.

[0296] [Pencil Hardness]

[0297] Using evaluation coating samples coated on the aforementioned easily bondable PET, the pencil hardness was determined with a 1 kg load according to the method of JIS K 5600-5-4.

[0298] [ABS fit]

[0299] Using an evaluation coating sample coated on the aforementioned acrylonitrile-butadiene-styrene copolymer resin (ABS) white board, as an evaluation of the adhesion between the cured coating and the ABS board, a 1mm cross-cut checkerboard adhesion test was performed (according to the test method of JISK 5600-5-6) to determine the number of squares without peeling or gaps.

[0300] [PC Sealing]

[0301] Using the evaluation coating sample coated on the above-mentioned polycarbonate (PC) board, as an evaluation of the adhesion between the cured coating and the PC board, a 1 mm cross-cut checkerboard adhesion test was performed (according to the test method of JIS K 5600-5-6) to determine the number of squares without peeling or gaps.

[0302] The evaluation coating samples coated on the aforementioned PC boards were immersed in boiling water for 2 hours. The appearance of the cured coating and the PC adhesion were evaluated as follows. It should be noted that, for the PC adhesion, before the boiling water resistance test as described above, the number of non-peeling, gap-free squares in the cross-cut checkerboard section was measured again to evaluate the PC adhesion.

[0303] [Appearance after boiling water resistance test]

[0304] 1: No whitening, remains transparent

[0305] 2: Albinism was observed in some areas.

[0306] 3: Albinism was observed.

[0307] [Table 1]

[0308]

[0309] [Table 2]

[0310]

[0311] [Table 3]

[0312]

[0313] [Table 4]

[0314]

[0315] [Table 5]

[0316]

[0317] [Table 6]

[0318]

[0319] [Table 7]

[0320]

[0321] <Preparation of Dispersion>

[0322] [Example B1]

[0323] In a cylindrical container, urethane acrylate (A2-5), a photopolymerizable compound (A1-0), and urethane acrylate (B1-1) were added. After heating at 60°C, a surfactant (B2-1) was added. While stirring using a dispenser, purified water at 50°C was added. Finally, the mixture was stirred while being brought back to room temperature to prepare an aqueous emulsion composition (50% non-volatile components). The formulation is shown in Table 8.

[0324] [Examples B2-B4 and Comparative Examples B1 and B2]

[0325] As shown in Table 8, the formulation was modified, except that the aqueous emulsion composition (50% non-volatile components) was prepared in the same manner as in Example B1.

[0326] [Example B9]

[0327] In a cylindrical container, urethane acrylate (A2-7), a photopolymerizable compound (A1-0), and urethane acrylate (B1-1) were added. After heating at 60°C, a monofunctional reactive surfactant (B2-1) and triethylamine (as a base to neutralize the acid groups of urethane acrylate (A2-7)) were added. While stirring using a dispenser, purified water at 55°C was added. Finally, the mixture was stirred while being brought back to room temperature to prepare an active energy radiation-curable aqueous emulsion composition (50% non-volatile components). The formulation is shown in Table 8.

[0328] [Examples B10-B18]

[0329] As shown in Table 8, the formulation was modified, except that the aqueous emulsion composition (50% non-volatile components) was prepared in the same manner as in Example B9.

[0330] <Evaluation>

[0331] The following evaluations were performed on the aqueous emulsion compositions obtained in each example.

[0332] [Viscosity at 25℃]

[0333] For the aqueous emulsion compositions containing 50% non-volatile components prepared in Examples B1-B4 and B9-B18, the viscosity at 25°C was measured using an E-type viscometer (100 rpm).

[0334] [Average nucleus size]

[0335] For the aqueous emulsion compositions containing 50% nonvolatile components prepared in Examples B1-B4, B9-B18 and Comparative Examples B1 and B2, the average nucleus size (volume-based average diameter) was determined using a laser scattering / diffraction apparatus (Horiba Manufacturing Co., Ltd.; LA950V2).

[0336] [Storage stability at room temperature]

[0337] The aqueous emulsion compositions containing 50% non-volatile components prepared in Examples B1-B4, B9-B18 and Comparative Examples B1 and B2 were added to a covered container, and the number of days that could be stored at room temperature (25°C) was evaluated by visual inspection as follows.

[0338] (Evaluation Criteria)

[0339] 1: No separation or precipitation after 2 months

[0340] 2: No separation or precipitation occurred within 1 week to less than 2 months.

[0341] 3: No separation or precipitation for more than 3 days but less than 1 week

[0342] 4: Separation and precipitation within 2 days

[0343] [Storage stability at 40℃]

[0344] The aqueous emulsion composition containing 50% non-volatile components prepared in Examples B1 to B4 was added to a container with a lid. After standing at 40°C for 2 weeks, the appearance of the solution was observed and the particle size was measured. The evaluation was carried out according to the following criteria.

[0345] (Evaluation Criteria)

[0346] 1: No increase in particle size

[0347] 2: The particle size is slightly increased (the increase is less than 100 nm).

[0348] 3: Increased particle size (more than 100 nm).

[0349] 4: Separation of precipitates or particles with a diameter exceeding 1000 nm

[0350] [Examples B5-B8, B19-B28]

[0351] Using the aqueous emulsion composition with 50% non-volatile components obtained in Examples B1 to B4, coating samples were prepared and evaluated by the method described later.

[0352] [Preparation of Evaluation Coating Samples]

[0353] 100 parts by weight of solids composition relative to the aqueous emulsion compositions with 50% non-volatile components obtained in Examples B1-B4 and B9-B18, as shown in Table 9, were mixed with a photopolymerization initiator (C-2) and a surface conditioner (product name: TegoWet270; manufactured by Evonik Japan). The mixture was applied using a rod coater to easily bondable polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd.; COSMOSHINE A4360, thickness 125 μm), acrylonitrile-butadiene-styrene copolymer resin (ABS) white board (manufactured by Nippon Testpanel Co., Ltd.), or polycarbonate (PC) board (manufactured by Nippon Testpanel Co., Ltd.). After drying at 100°C for 2 minutes, the mixture was then subjected to a high-pressure mercury lamp with a cumulative light intensity of 1,000 mJ / cm². 2 The aqueous emulsion composition was cured by ultraviolet irradiation to prepare an evaluation coating sample with a film thickness of 10 μm. The obtained evaluation coating sample was then used for the following evaluation.

[0354] [Coating Appearance]

[0355] The surface condition of the coating samples is observed and evaluated according to the following criteria.

[0356] (Evaluation Criteria)

[0357] 1: No shrinkage cavities were observed.

[0358] 2: No shrinkage cavities were observed.

[0359] 3: Observe coating defects such as pinholes and bumps.

[0360] [Pencil Hardness]

[0361] Using evaluation coating samples coated on the aforementioned easy-to-adhere PET film, the pencil hardness was determined under a 750g load according to the method of JIS K 5600-5-4.

[0362] [Flexibility]

[0363] For the evaluation coating samples, the bending performance was evaluated using a cylindrical mandrel bending tester according to JIS K 5600-5-1. When the evaluation coating sample was wound around the test bar, the maximum diameter (integer value, mm) at which cracks or peeling occurred was measured, and the evaluation was performed as follows.

[0364] (Evaluation Criteria)

[0365] 1: Less than 2 (even with a diameter of 2mm, no cracks will occur)

[0366] 2:2-3

[0367] 3:4-5

[0368] 4:6 and above

[0369] [ABS fit]

[0370] Evaluation samples of the coating applied to ABS white boards were used to evaluate the adhesion between the cured coating and the ABS board. A 1mm cross-cut checkerboard adhesion test was conducted to determine the number of squares without peeling or gaps.

[0371] [PC Sealing]

[0372] Evaluation samples of the coating applied to PC boards were used to evaluate the adhesion between the cured coating and the PC board. A 1mm cross-cut checkerboard adhesion test was conducted to determine the number of squares without peeling or gaps.

[0373] [Preparation of Coated Samples for Elongation Evaluation]

[0374] According to the solid component mixing ratios of Examples B1-B4 and B9-B18 in Table 8, 4 parts of photopolymerization initiator (C-3) were added relative to 100 parts of the solid component of the mixture. The mixture was diluted with ethyl acetate at 70-80% of the solid component to prepare an active energy X-ray curable composition. The prepared active energy X-ray curable composition was applied to a release polyethylene terephthalate (PET) film (100 μm thick) using a dressing applicator. After drying at 60°C for 30 minutes, a high-pressure mercury lamp was used to apply the mixture with a cumulative light intensity of 1000 mJ / cm². 2 The active energy ray curable composition was cured by ultraviolet irradiation to produce an evaluation coating sample with a film thickness of 100 μm. Then, the evaluation coating sample was cut into strips with a width of 15 mm and a length of 75 mm using a dumbbell punch. The cured coating was then peeled off from the PET film to produce an elongation evaluation coating sample.

[0375] [Elongation]

[0376] For coating samples used for elongation evaluation, tensile tests were conducted at 23°C and 50% humidity using an "AG-X" tensile testing machine (manufactured by Shimadzu Corporation) according to JIS K 7127. The elongation at the fracture point of the coating was measured at a tensile speed of 10 mm / min.

[0377] The evaluation results for each case are shown in Tables 8 and 9.

[0378] [Table 8]

[0379]

[0380] [Table 9]

[0381]

[0382] As shown in Tables 8 and 9, the aqueous emulsion compositions of Examples B1-B4 and B9-B18, which were forcibly emulsified using two or more surfactants containing surfactant (B1), exhibited smaller and more uniform particle sizes and superior storage stability at room temperature and 40°C compared to the emulsion compositions of Comparative Examples B1 and B2. Furthermore, the coatings of Examples B5-B8 and B19-B28, which used the aqueous emulsion compositions of Examples B1-B4 and B9-B18, showed excellent adhesion to the substrate.

[0383] Furthermore, the coatings of Examples B5-B7 and B19-B28, which used aqueous emulsion compositions of Examples B1-B3 and B9-B18 containing urethane (meth)acrylate (A2), exhibited superior softness compared to the coating of Example B8, which used an aqueous emulsion composition of Example B4 that did not contain urethane (meth)acrylate (A2).

[0384] Industrial availability

[0385] The aqueous emulsion composition using the active energy ray curable composition of the present invention is very useful as a coating material for various coatings, such as paints, adhesives, bonding agents, inks, protective coatings, anchoring coatings, hard coatings, magnetic powder coating adhesives, sandblasting coatings, printing plates, top coatings for optical films, metal vapor deposition, sputtered films, and glass-facing finishing coatings, due to its excellent storage stability at room temperature and high temperature, excellent freeze-thaw stability, and excellent adhesion and water resistance of the coating film during application.

Claims

1. An active energy ray-curable composition, which is an active energy ray-curable composition containing two or more surfactants, and further containing a photopolymerizable compound A, at least one of the surfactants is a surfactant B1 which is a urethane (meth)acrylate having a polyoxyalkylene chain in the structure and having two or more functional groups having a double bond, The surface active agent contains a surface active agent B2, and the surface active agent B2 is a surface active agent represented by the following general formula (1) in which, the surfactant B2 does not include the surfactant B1, XO-(Y1O) m -(Y2O) n -SO3Z…(1) wherein X is a functional group having a double bond, Y1 and Y2 are alkylene groups, and Y1 and Y2 are different groups, Z is a counter ion, m is an integer of 1 or more, and n is an integer of 0 or more, the photopolymerizable compound A contains at least one selected from a (meth)acrylate monomer A1 and a urethane (meth)acrylate A2, wherein the urethane (meth)acrylate A2 does not include the surfactant B1, the content of the photopolymerizable compound A is 40 to 99% by mass, the content of the surfactant B1 is 0.9 to 59.9% by mass, and the content of the surfactant B2 is 0.1 to 20% by mass, with respect to 100% by mass of the total of the photopolymerizable compound A and the surfactants, the content of the surfactant B1 is 50% by mass or more with respect to the total mass of the surfactants.

2. The active energy ray-curable composition according to claim 1, further containing a photopolymerization initiator C.

3. The active energy ray-curable composition according to claim 1, containing water.

4. An aqueous emulsion composition containing the active energy ray-curable composition according to claim 1 or 2.

5. A coating agent composition containing the active energy ray-curable composition according to any one of claims 1 to 3.

6. A laminate having at least one layer formed of the active energy ray-curable composition according to claim 1 or 2.

7. The aqueous emulsion composition according to claim 4, the aqueous emulsion composition is an emulsion-like composition obtained by emulsifying the active energy ray-curable composition in an aqueous solvent containing water, a coating film formed under the following conditions has a pencil hardness of 2H or more measured by the method according to JIS K 5600-5-4 with a load of 1 kg, <Coating film forming conditions> The water-based emulsion composition was applied to the surface of an easily-adhesive polyethylene terephthalate film having a thickness of 125 μm using a bar coater, and after drying at 100°C for 2 minutes, it was cured by ultraviolet irradiation using a high-pressure mercury lamp at a cumulative light amount of 450 mJ / cm 2 in such a manner as to form a coating film having a thickness of 10 μm.

Images