Method for producing water-soluble epoxy (meth)acrylate composition, emulsion, coating composition, coating film, and cured coating film

Abstract

To provide a method for producing a water-soluble epoxy (meth)acrylate composition that exhibits very high self-emulsifiability, and yields an emulsion having superior storage stability and freeze-thaw stability, as well as small emulsion particle size.SOLUTION: A method for producing a water-soluble epoxy (meth)acrylate composition is provided, the method comprising: reacting 1 mol of a carboxylic acid anhydride (A) having m acid anhydride groups with q mol of a polyethylene glycol derivative (B) containing one terminal hydroxyl group represented by formula (I), and k mol of a hydroxyl group-containing (meth)acrylate compound (C); and subsequently reacting h mol of an epoxy compound (D) having j epoxy groups with g mol of a compound (E) having a carboxyl group and a (meth)acryloyl group, under conditions satisfying m≤q+k, m≤2h, and g≥h×j-m. H-(OCH2CH2)n-O-Y (I) [where Y is an alkyl group, a (meth)acryloyl group, an allyl group, or an acyl group, and n is an integer of 18 or more].SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing a water-soluble epoxy (meth) acrylate composition, an emulsion, a coating composition, a coating film, and a cured coating film.

Background Art

[0002] Conventionally, epoxy (meth) acrylate has been produced by a batch method using a reaction kettle. In particular, hydrophobic epoxy (meth) acrylate is produced by reacting the carboxyl group of a compound having a carboxyl group and a (meth) acryloyl group with the epoxy group of a compound having an epoxy group (Patent Document 1), or by reacting a reaction product of an epoxy compound and an unsaturated monocarboxylic acid with carboxylic acid anhydrides such as phthalic anhydride, trimellitic anhydride, and pyromellitic anhydride (Patent Document 2). In addition, a method for producing an epoxy (meth) acrylate emulsion by using a reactive emulsifier for the epoxy (meth) acrylate obtained by the above production method has been proposed (Patent Document 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the epoxy (meth) acrylate obtained by the above production method is highly hydrophobic and does not disperse or dissolve in water at all by itself. Furthermore, the epoxy (meth)acrylate emulsion obtained by the above manufacturing method has poor storage stability at -5°C, and the epoxy (meth)acrylate separates from the water within a few hours. The present invention aims to provide a method for producing a water-soluble epoxy (meth)acrylate composition, an emulsion, a coating composition, and a coating film or cured coating film that exhibits extremely high self-emulsifying properties, small emulsion particle size, and excellent storage stability and freeze-thaw stability. [Means for solving the problem]

[0005] This application includes the following inventions. (1) A method for producing a water-soluble epoxy (meth)acrylate composition by reacting 1 mole of carboxylic acid anhydrides (A) having m acid anhydride groups with q moles of a polyethylene glycol derivative (B) containing a hydroxyl group at one end represented by formula (I) and k moles of a hydroxyl group-containing (meth)acrylate compound (C), and then reacting h moles of an epoxy compound (D) having j epoxy groups with g moles of a compound (E) having a carboxyl group and a (meth)acryloyl group, A method for producing a water-soluble epoxy (meth)acrylate composition by reacting under conditions that satisfy m ≤ q + k, m ≤ 2h, and g ≥ h × jm. H-(OCH2CH2) n -OY (1) [In the formula, Y is an alkyl group, a (meth)acryloyl group, an allyl group, or an acyl group, and n is an integer of 18 or more.] (2) A method for producing the water-soluble epoxy (meth)acrylate composition described in (1), carried out by reacting under conditions that satisfy 2≦m≦4, 0.5≦q≦3, 0.5≦k≦2, 2≦j≦3 and 2≦h≦8. (3) A method for producing the above-described water-soluble epoxy (meth)acrylate composition, wherein the polyethylene glycol derivative (B) containing a single-ended hydroxyl group is polyethylene glycol monomethyl ether, polyethylene glycol lauryl ether, polyethylene glycol mono(meth)acrylate, or polyethylene glycol monoallyl ether. (4) A method for producing the above-described water-soluble epoxy (meth)acrylate composition, wherein the hydroxyl group-containing (meth)acrylate compound (C) is a polyfunctional hydroxyalkyl (meth)acrylate, polyol (meth)acrylate, or alkylene oxide-added polyol (meth)acrylate having a polyfunctional (meth)acryloyl group. (5) A method for producing the above-described water-soluble epoxy (meth)acrylate composition, wherein the epoxy compound (D) is a bisphenol-type epoxy resin, a resorcinol glycidyl ether, or a polyalkylene glycol glycidyl ether. (6) An emulsion containing a water-soluble epoxy (meth)acrylate composition obtained by the method described above. (7) A coating composition comprising a water-soluble epoxy (meth)acrylate composition obtained by the method described above. (8) The coating composition according to (7), further comprising at least one of an ethylenically unsaturated monomer, a curing agent, a photopolymerization initiator, and a polymerization catalyst. (9)(8) A coating film which is a thermoset product of a coating composition containing the water-soluble epoxy (meth)acrylate composition described above. (10)(8) A coating composition comprising a water-soluble epoxy (meth)acrylate composition, cured by active energy ray irradiation. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a method for producing a water-soluble epoxy (meth)acrylate composition, an emulsion, a coating composition, and a coating film or cured coating film that exhibits extremely high self-emulsifying properties, excellent storage stability and freeze-thaw stability, and small emulsion particle size. [Modes for carrying out the invention]

[0007] In this specification, "(meth)acrylate" and "(meth)acrylic acid" mean "at least one selected from the group consisting of acrylates and methacrylates" and "at least one selected from the group consisting of acrylic acid and methacrylic acid," respectively.

[0008] [Method for producing a water-soluble epoxy (meth)acrylate composition] In the method for producing a water-soluble epoxy (meth)acrylate composition in this application, first, 1 mole of a carboxylic acid anhydride (A) having m acid anhydride groups is reacted with q moles of a polyethylene glycol derivative (B) containing a hydroxyl group at one end represented by formula (I) and k moles of a hydroxyl group-containing (meth)acrylate compound (C). The compounds to be reacted may be used individually or in combination of two or more types.

[0009] (Carboxylic acid anhydrides (A)) Examples of carboxylic acid anhydrides include dibasic acid anhydrides such as acetic anhydride, maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, chloridenic anhydride, and methyltetrahydrophthalic anhydride; aromatic polycarboxylic acid anhydrides such as trimellitic anhydride, pyromellitic anhydride, biphenyltetracarboxylic acid dianhydride, and benzophenonetetracarboxylic acid dianhydride, as well as other related polycarboxylic acid anhydride derivatives such as 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride. Examples of carboxylic acid anhydrides include those having m acid anhydride groups, for example, m is preferably 2 or more. Also, m is 10 or less, preferably 5 or less, and more preferably 4 or less.

[0010] (Polyethylene glycol derivative containing a hydroxyl group at one end (B)) The polyethylene glycol derivative (B) containing a hydroxyl group at one end is a derivative represented by formula (I). H-(OCH2CH2) n -OY (I) [In the formula, Y is one of an alkyl group, a (meth)acryloyl group, an allyl group, or an acyl group, and n is an integer of 18 or more.] When Y is an alkyl group, examples include polyethylene glycol derivatives such as polyethylene glycol monomethyl ether, polyethylene glycol lauryl ether, polyethylene glycol cetyl ether, polyethylene glycol stearyl ether, polyethylene glycol nonylphenyl ether, polyethylene glycol tridecyl ether, polyethylene glycol oleyl ether, polyethylene glycol octylphenyl ether, and polyoxyethylene oleyl cetyl ether. When Y is a (meth)acryloyl group, examples include polyethylene glycol derivatives such as polyethylene glycol mono(meth)acrylate, polyethylene glycol-polypropylene glycol-mono(meth)acrylate, and poly(ethylene glycol-tetramethylene glycol) mono(meth)acrylate. When Y is an allyl group, examples include polyethylene glycol derivatives such as polyethylene glycol monoallyl ether and polyethylene glycol-polypropylene glycol-monoallyl ether. When Y is an acyl group, examples include polyethylene glycol derivatives such as polyethylene glycol monolaurate, polyethylene glycol monostearate, and polyethylene glycol monooleate. In particular, Y is preferably an alkyl group or a (meth)acryloyl group, and more preferably a polyethylene glycol derivative. In this case, for example, those with an ethylene oxide addition mole number n of 18 to 500 are examples, preferably 18 to 100, more preferably 18 to 50, and even more preferably 20 to 45 in terms of the balance between hydrophilic and hydrophobic groups. By setting the ethylene oxide addition mole number n within this range, stable emulsification and dispersibility can be obtained, and the hardness, abrasion resistance, water resistance, and solvent resistance of the cured coating film can be improved. From another perspective, the weight-average molecular weight of the one-terminal hydroxyl group-containing polyethylene glycol derivative represented by the formula (I) may be 850 to 20,000, preferably 850 to 5,000, and more preferably 900 to 2,000. The weight-average molecular weight means the weight-average molecular weight in terms of standard polystyrene molecular weight, and it can be measured by using three columns in series of high-performance liquid chromatography (manufactured by Showa Denko K.K., "Shodex GPC system-11 type") with the column: Shodex GPC KF-806L (exclusion limit molecular weight: 2×10 7 , separation range: 100 to 2×10 7 , theoretical plate number: 10,000 plates per column, packing material: styrene-divinylbenzene copolymer, packing particle size: 10 μm). By setting the weight-average molecular weight within this range, stable emulsion dispersibility can be obtained, and the hardness, scratch resistance, water resistance, solvent resistance, and hot water resistance of the cured coating film can be improved. Furthermore, the hydroxyl value of the one-terminal hydroxyl group-containing polyethylene glycol derivative represented by the formula (I) may be 2 to 65 mgKOH / g, preferably 10 to 65 mgKOH / g, and more preferably 28 to 62 mgKOH / g. By setting the hydroxyl value within this range, the water resistance and emulsion stability of the cured coating film can be improved.

[0011] (Hydroxyl group-containing (meth)acrylate compound (C)) Examples of hydroxyl group-containing (meth)acrylate compounds include hydroxyalkyl (meth)acrylates, polyol (meth)acrylates, or alkylene oxide-added polyol (meth)acrylates. Examples of hydroxyalkyl (meth)acrylates include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and hydroxyphenoxypropyl (meth)acrylate. Examples of polyol (meth)acrylates include glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate. Examples of alkylene oxide-added polyol (meth)acrylates include alkylene oxide-added trimethylolpropane di(meth)acrylate, alkylene oxide-added pentaerythritol tri(meth)acrylate, and alkylene oxide-added dipentaerythritol penta(meth)acrylate.

[0012] When reacting 1 mole of carboxylic acid anhydrides (A) having acid anhydride groups with a polyethylene glycol derivative (B) containing a hydroxyl group at one end, represented by formula (I), and a hydroxyl group-containing (meth)acrylate compound (C), the reaction is carried out in amounts of q moles of the polyethylene glycol derivative (B) and k moles of the hydroxyl group-containing (meth)acrylate compound (C) for 1 mole of carboxylic acid anhydrides (A) having m acid anhydride groups. Here, it is preferable that m, q, and k satisfy the relationship m ≤ q + k. For q, examples include 0.1 or more, preferably 0.5 or more. Also, examples include 10 or less, preferably 5 or less, and more preferably 3 or less. For k, examples include 0.1 or more, preferably 0.5 or more, preferably 5 or less, preferably 3 or less, and more preferably 2 or less. In other words, it is more preferable to carry out the reaction in such a way that 2 ≤ m ≤ 4, 0.5 ≤ q ≤ 3, and 0.5 ≤ k ≤ 2 simultaneously. These reactions may be carried out by sequentially or simultaneously adding carboxylic acid anhydrides (A), polyethylene glycol derivatives with a hydroxyl group at one end (B), and hydroxyl group-containing (meth)acrylate compounds (C), and reacting the mixture with stirring within a temperature range from room temperature to about 100°C for 1 to 24 hours. The end point of the reaction can be set, for example, from the molecular weights of the carboxylic acid anhydrides (A), the polyethylene glycol derivatives with a hydroxyl group at one end represented by the formula (I) (B), and the hydroxyl group-containing (meth)acrylate compounds (C).

[0013] Also, when reacting 1 mol of carboxylic acid anhydrides (A) having m acid anhydride groups with q mol of polyethylene glycol derivatives with a hydroxyl group at one end represented by the formula (I) (B) and k mol of hydroxyl group-containing (meth)acrylate compounds (C), polymerization inhibitors, reaction catalysts, diluents, etc. can be used alone or as a mixture of two or more. Any of those known in the art may be used. As the polymerization inhibitor, conventionally known polymerization inhibitors can be used, for example, 2,6-di-tert-butylcresol, methoquinone, hydroquinone, 1,4-naphthoquinone, phenothiazine, t-butylhydroquinone, aluminum N-nitrophenylhydroxylamine, etc. As the reaction catalyst, conventionally known catalysts (initiators) can be used, for example, phosphines such as triphenylphosphine, tertiary amines such as triethylamine, quaternary ammonium salts such as tetramethylammonium salt and benzyltrimethylammonium salt, quaternary phosphonium salts, imidazoles such as 2-methylimidazole and 2-methyl-4-methylimidazole. Their usage amounts are not particularly limited, and examples include 0.01 to 5% by weight based on 100% by weight of the reactants. As a diluent, a photopolymerizable monomer and / or an organic solvent can be used. Examples of photopolymerizable monomers include water-soluble monomers such as N-vinylpyrrolidone, acryloyl morpholine, and methoxytetraethylene glycol acrylate; water-insoluble monomers such as pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate; and organic solvents such as ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; and cellosolves such as cellosolve and butyl cellosolve. The diluent can be used in an amount of 0 to 300 parts by weight, preferably 0 to 200 parts by weight, per 100 parts by weight of the reactant. In particular, it is preferable that the diluent does not contain an organic solvent or contains only a small amount (for example, 1 part by weight or less). In recent years, due to environmental pollution concerns and the need for energy conservation, active energy ray curing compositions, which harden when exposed to active energy rays such as ultraviolet light, have been widely used as an alternative to organic solvent-based paints. However, in practical terms, some varieties of these compositions still require the use of small amounts of organic solvents to improve their coating properties. Therefore, by eliminating the use of the aforementioned organic solvents, it is possible to meet the demand for a shift to water-dispersible types that do not use any organic solvents, in line with the current stringent social environment's VOC (volatile organic compound) countermeasures.

[0014] Next, 1 mole of carboxylic acid anhydrides (A) having m acid anhydride groups is reacted with q moles of a polyethylene glycol derivative (B) containing a hydroxyl group at one end, represented by formula (I), and k moles of a hydroxyl group-containing (meth)acrylate compound (C). This reaction product is then reacted with h moles of an epoxy compound (D) having j epoxy groups and g moles of a compound (E) having carboxyl groups and (meth)acryloyl groups. The compounds reacted may be used individually or in combination of two or more. This allows for the production of a water-soluble epoxy (meth)acrylate composition.

[0015] (Epoxy compound (D)) Examples of epoxy compounds include epoxy resins. Examples of epoxy resins include bisphenol-type epoxy resins, naphthalene-type epoxy resins, novolac-type epoxy resins such as cresol novolac-type and phenol novolac-type epoxy resins; halogenated bisphenol-type epoxy resins, halogenated novolac-type epoxy resins; as well as polycarboxylic acid glycidyl ester-type resins, aliphatic epoxy resins, and alicyclic epoxy resins; polyalkylene glycol diglycidyl ethers, allyl glycidyl ethers, phenyl glycidyl ethers, triglycidyl isocyanurates and their derivatives; and copolymers of glycidyl group-containing unsaturated monomers such as polyglycidyl (meth)acrylate and glycidyl (meth)acrylate with other unsaturated monomers. Examples of epoxy compounds include those having j epoxy groups. For example, j may be 1, but is preferably 2 or more. Also, examples include those with 10 or fewer epoxy groups, preferably 5 or fewer, more preferably 4 or fewer, and even more preferably 3 or fewer.

[0016] (Compound (E) having a carboxyl group and a (meth)acryloyl group) Examples of compounds having a carboxyl group and a (meth)acryloyl group include acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, maleic acid, fumaric acid, citraconic acid, and mesaconic acid. It is sufficient for the compound to contain one or more carboxyl groups and one or more (meth)acryloyl groups.

[0017] When reacting the above-mentioned reactant with h moles of an epoxy compound (D) having j epoxy groups and g moles of a compound (E) having carboxyl groups and (meth)acryloyl groups, the above-mentioned reactant is reacted with (1+q+k) moles of the above-mentioned reactant with h moles of the epoxy compound (D) having j epoxy groups and g moles of the compound (E) having carboxyl groups and (meth)acryloyl groups. Here, it is preferable that j, h, and g simultaneously satisfy m ≤ 2h and g ≥ h × jm. Specifically, j may be 5 or less, preferably 4 or less, more preferably 3 or less, and particularly preferably 2 or 3. As described above, when m is 2 to 4 and j is 2 or 3, h may be 8 or less and 1 or more, preferably less than 6, and even more preferably 2 or more and less than 5. When m is between 2 and 4 and j is 2 or 3, g can be between 0 and 22, preferably between 2 and 20, more preferably between 2 and 14, even more preferably between 2 and 12, and even more preferably between 2 and 4. In other words, it is preferable to carry out the reaction such that, in addition to 2≦m≦4, 0.5≦q≦3, and 0.5≦k≦2, it is also preferable to satisfy 2≦j≦3 and 2≦h≦8 simultaneously. Furthermore, in this reaction, polymerization inhibitors, reaction catalysts, diluents, etc., can be used individually or as a mixture of two or more. Any of these known in the art may be used.

[0018] [Water-soluble epoxy (meth)acrylate composition] Thus, by reacting 1 mole of carboxylic acid anhydrides (A) having m acid anhydride groups with q moles of a polyethylene glycol derivative (B) containing a hydroxyl group at one end represented by formula (I) and k moles of a hydroxyl group-containing (meth)acrylate compound (C) with the reaction product obtained, and then reacting the resulting product with h moles of an epoxy compound (D) having j epoxy groups and g moles of a compound (E) having a carboxyl group and a (meth)acryloyl group, the water-soluble epoxy (meth)acrylate composition obtained is first made by reacting carboxylic acid anhydrides (A) with a polyethylene glycol derivative containing a hydroxyl group at one end ( When B) is bonded to the hydroxyl group-containing (meth)acrylate compound (C), the resulting carboxyl group reacts with some of the epoxy groups of the epoxy compound (D), while other epoxy groups react with the carboxyl group of the compound (E) having a (meth)acryloyl group. As a result, the polyethylene glycol derivative (B) containing a hydroxyl group at one end is bonded to the carboxylic acid anhydride in a pendant-like manner, achieving a balance between hydrophilic and hydrophobic groups in the molecule. The water-soluble epoxy (meth)acrylate composition obtained by this invention exhibits extremely good self-emulsifying properties. Furthermore, because it is substantially free of organic solvents, it can reduce the environmental burden. Moreover, the obtained water-soluble epoxy (meth)acrylate composition can be made into a nonionic emulsion, preventing inhibition of emulsion properties such as aggregation, precipitation, and separation even when various additives are added to coating compositions, etc. On the other hand, when components (A) to (E) described above are reacted together, the reactions of the acid anhydride group and the hydroxyl group, the acid anhydride group and the epoxy group, the carboxyl group and the epoxy group, and the reaction between the hydroxyl group generated by the reaction of the carboxyl group and the epoxy group and the acid anhydride group proceed simultaneously. This disrupts the balance of the pendant-like bonds, resulting in a compound with a cross-linked structure, and gelation often occurs. When gelation occurs, not only is a stable reaction impossible, but the resulting reactant becomes poorly soluble in water. Similarly, if the relationship between the number of functional groups and the number of moles in each component deviates from the conditions described above, the balance of the pendant-like bonds is disrupted, leading to gelation or insolubility in water. Furthermore, when a compound containing hydroxyl groups at both ends is used instead of the polyethylene glycol derivative (B) containing a hydroxyl group at one end, the water resistance of the cured coating film of the resulting water-soluble epoxy (meth)acrylate composition deteriorates.

[0019] The emulsions and coating compositions of the present invention are themselves water-soluble and can form functionally superior cured coatings with high solvent resistance and hardness. Here, water solubility means that when water is added to the epoxy (meth)acrylate composition, it does not separate, no sediment is generated even after standing for one hour, and furthermore, no separation or sedimentation occurs even after being left overnight. In particular, it is preferable that the absence of separation and sedimentation can be achieved under the conditions described in the examples. In other words, by emulsifying using the emulsification method described above (e.g., phase inversion emulsification), the resulting emulsion has a relatively small average particle size of 500 nm or less, and is stable over long periods (no secondary aggregation occurs), meaning it has high storage stability (-5°C, 40°C). In addition, it also exhibits excellent freeze-thaw stability.

[0020] [Emulsified and coating compositions] The resulting water-soluble epoxy (meth)acrylate composition is self-emulsifying, can be developed with a dilute alkaline aqueous solution, and exhibits excellent properties such as heat resistance, solvent resistance, acid resistance, plating resistance, adhesion, electrical properties, and hardness. Therefore, the water-soluble epoxy (meth)acrylate composition obtained by the above-described manufacturing method can be used as is as a coating composition. However, by adding water to the water-soluble epoxy (meth)acrylate composition, for example, it can be used as a coating composition in the form of an emulsified liquid water-soluble epoxy (meth)acrylate composition, i.e., an emulsion. Furthermore, coating compositions may be prepared by incorporating various additives. To this end, water is first added to the water-soluble epoxy (meth)acrylate composition obtained above, either all at once or gradually. At this time, it is preferable to maintain the temperature of the obtained water-soluble epoxy (meth)acrylate composition in a range of, for example, 20°C to 40°C, and to adjust the temperature of the water to be added to a range equivalent to this, more preferably in the range of 15°C to 40°C or 30°C to 40°C. Various types of water can be used for addition, such as tap water, deionized water, ion-exchanged water, and distilled water. Water addition is preferably carried out in installments or in a single batch. In the case of installment addition, the amount added per installment is preferably 100% to 200% by weight of the mass of the water-soluble epoxy (meth)acrylate composition, more preferably 150% to 200% by weight. The amount of water added is preferably such that the resin concentration is 50% by weight or less, more preferably 35% to 45% by weight, and even more preferably 20% to 40% by weight.

[0021] Next, the mixture of water and the water-soluble epoxy (meth)acrylate composition is stirred. Stirring can be performed, for example, simultaneously with the addition of water, using any method known in the art. Stirring can be performed using a stirrer, disperser, turbine blade, or Maxblend blade, but since the water-soluble epoxy (meth)acrylate composition has high viscosity at the emulsification temperature (below the cloud point), it is preferable to stir using a stirring blade that provides a small power load when water is added. As stirring blades, for example, paddle blades or anchor blades can be used. Paddle blades can be positioned near the interface between the water-soluble epoxy (meth)acrylate composition and water, or slightly on the water side of the interface, and may have only one blade or two or more blades arranged in multiple stages. Stirring speeds can range from 10 rpm to 10,000 rpm, but since the water-soluble epoxy (meth)acrylate composition has good self-emulsifying properties, a rotation speed of 500 rpm or less is preferred, 200 rpm or less is more preferred, and 10 rpm to 300 rpm or 10 rpm to 100 rpm is particularly preferred. Furthermore, it is preferable to continue stirring even after the addition of water has been completed. In this case, as the power load decreases as emulsification progresses, it is preferable to gradually increase the rotation speed and continue stirring until a uniform emulsified state is reached.

[0022] Additives that may be added to the water-soluble epoxy (meth)acrylate composition include leveling agents, curing agents, ethylenically unsaturated monomers, photopolymerization initiators, photopolymerization initiator aids, fillers, dyes and pigments, oils, plasticizers, waxes, drying agents, dispersants, wetting agents, emulsifiers, gelling agents, stabilizers, defoaming agents, thixotropy-imparting agents, antioxidants, flame retardants, antistatic agents, fillers, reinforcing agents, matting agents, crosslinking agents, and the like. Any of these commonly used in the field may be used. These components may be added to the water-soluble epoxy (meth)acrylate composition simultaneously or sequentially and mixed. Leveling agents play a role in removing popping and craters on the surface during film coating and are broadly classified into silicone-based and non-silicone-based leveling agents. Silicone-based leveling agents are characterized by their orientation on the coating surface, which reduces the surface tension of the coating surface and exerts a leveling effect. The effect of reducing surface tension is significant, resulting in a high leveling effect and improving repellency and dents caused by low surface tension substances. Non-silicone-based leveling agents, such as acrylic polymer-based leveling agents, are characterized by their orientation on the coating surface, similar to silicone-based agents, and by controlling the viscosity increase due to solvent evaporation, they delay the allowable leveling time. Furthermore, by orientation on the surface, they slightly reduce and homogenize the surface tension of the coating surface, thereby exerting a leveling effect. For example, as water-based silicone leveling agents, TEGO Glide482 from Evonik, BYK-3456 and BYK-3760 from BIC Chemie, and Polyflow KL401, KL402, and Polyflow KL100 from Kyoeisha Chemical can be used. As water-based non-silicone leveling agents, BYK ETOL-AQ and BYK ETOL-WS from BIC Chemie, and Polyflow WS, Polyflow WS-314, and Polyflow KL900 from Kyoeisha Chemical can be used. The leveling agent is present in an amount of 0.1% to 10% by weight relative to the resin concentration, preferably 0.5% to 5% by weight. As a curing agent, a radical polymerization initiator that causes addition polymerization of vinyl monomers by radical decomposition by heat or a reducing substance is preferred. Examples include water-soluble persulfates, peroxides, and azobis compounds. Specifically, examples include potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, 2,2-azobisisobutyronitrile, 2,2-azobis(2-diaminopropane)hydrochloride, and 2,2-azobis(2,4-dimethylvaleronitrile). In particular, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]tetrahydrate (product name: VA-057, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), N,N'-bis(2-hydroxyethyl)-2,2'-dimethyl-2,2'-diazendiyldipropanamide (product name: VA-086, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), bis[2-(4,5-dihydro-1H-imidazole-2-yl)propan-2-yl]diazen (product name: VA-061, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), azobisisobutyrate amidine hydrochloride (product name: V-50, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), (E)-1,2-bis[2-(4,5-dihydro-1H-imidazole-2-yl)propan-2-yl Water-soluble azo polymerization initiators such as diazene dihydrochloride (trade name: VA-044, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and azobiscyanovaleric acid (trade name: V-501, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and water-soluble organic peroxides such as tert-butyl hydroperoxide (trade name: Perbutyl H, manufactured by NOF Corporation) are preferred. The amount of curing agent is 0.001 to 10 parts by mass relative to the resin concentration, preferably 0.01 to 10 parts by mass, more preferably 0.05 to 8 parts by mass, and even more preferably 0.6 to 5 parts by mass.

[0023] By adding a photopolymerization initiator to epoxy (meth)acrylate and irradiating it with active energy rays, such as ultraviolet light, the epoxy (meth)acrylate and optionally ethylenically unsaturated monomers crosslink and / or polymerize to form a cured polymer. This cured polymer exhibits excellent curability, scratch resistance, surface hardness, and adhesion to plastic substrates.

[0024] The photopolymerization initiator is not particularly limited as long as it generates radicals upon the action of light, for example, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylenephenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyldimethyl Examples include ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3'-dimethyl-4-methoxybenzophenone, thioxanthone, 2-chlorthioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, camphorquinone, dibenzosverone, 2-ethylanthraquinone, 4',4"-diethylisophthalophenone, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, α-acyloxime ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthylenequinone, and 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone.

[0025] In particular, to better exhibit the functionality of the water-soluble epoxy (meth)acrylate composition, it is preferable to use a water-soluble or water-dispersible photopolymerization initiator. Examples of such photopolymerization initiators include 2-(3-dimethylamino-2-hydroxypropoxy)-3,4-dimethyl-9H-thioxanthone-9-one metochloride (Octel Chemicals, "Quantacure QTX"), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (Ciba Specialty Chemicals, "Irgacure 2959"), and among these, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (Ciba Specialty Chemicals, "Irgacure 2959" and IGM Resins BV, "Omnirad 2959") are more preferred. The amount of photopolymerization initiator is typically 0.002 to 10 parts by weight, preferably 0.01 to 10 parts by weight, more preferably 0.05 to 8 parts by weight, and particularly preferably 0.6 to 5 parts by weight, relative to the resin concentration of the water-soluble epoxy (meth)acrylate composition.

[0026] In addition, a photopolymerization initiator may be used in combination with the photopolymerization initiator. Examples of photopolymerization initiators include triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler ketone), 4,4'-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, 4-dimethylaminobenzoate ethyl, 4-dimethylaminobenzoate (n-butoxy)ethyl, 4-dimethylaminobenzoate isoamyl, 4-dimethylaminobenzoate 2-ethylhexyl, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone.

[0027] Examples of ethylenically unsaturated monomers that may be optionally added to the water-soluble epoxy (meth)acrylate composition include (meth)acrylic acid compounds and vinyl group-containing compounds. Examples of (meth)acrylic acid compounds include acrylamides, alkyl (meth)acrylates, aminoalkyl (meth)acrylates, quaternary salts of aminoalkyl (meth)acrylates, alkoxy polyalkylene glycol (meth)acrylates, hydroxyalkyl (meth)acrylates, acid anhydride adducts of hydroxyalkyl (meth)acrylates, polyalkylene glycol di(meth)acrylates, alkyldiol di(meth)acrylates, polyol poly(meth)acrylates, alkylene oxide-added polyol poly(meth)acrylates, etc. Examples of vinyl group-containing compounds include vinyl acetate, N-vinylacetamide, vinylpyrrolidone, vinyl alkyl ethers, vinyl sulfonic acid, and salts of vinyl sulfonic acid. These may be used individually or in combination of two or more. Examples of acrylamides include (meth)acryloylmorpholine and dimethylaminoalkyl(meth)acrylamide. Examples of aminoalkyl(meth)acrylates include diethylaminoethyl(meth)acrylate. Examples of quaternary salts of aminoalkyl(meth)acrylates include alkyloylaminopropyldimethyl-2-hydroxyethylammonium salt. Examples of alkyl(meth)acrylates include methyl(meth)acrylate, ethyl(meth)acrylate, and propyl(meth)acrylate. Examples of alkoxypolyalkylene glycol(meth)acrylates include methoxypolyethylene glycol(meth)acrylate and methoxypolypropylene glycol(meth)acrylate. Examples of hydroxyalkyl(meth)acrylates include hydroxyethyl(meth)acrylate and hydroxypropyl(meth)acrylate. Examples of acid anhydride adducts of hydroxyalkyl (meth)acrylate include hydroxyethyl (meth)acrylate phthalic anhydride adduct, hydroxyethyl (meth)acrylate succinic anhydride adduct, hydroxyethyl (meth)acrylate tetrahydrophthalic anhydride adduct, hydroxyethyl (meth)acrylate hexahydrophthalic anhydride adduct, hydroxypropyl (meth)acrylate phthalic anhydride adduct, hydroxypropyl (meth)acrylate succinic anhydride adduct, hydroxypropyl (meth)acrylate tetrahydrophthalic anhydride adduct, and hydroxypropyl (meth)acrylate hexahydrophthalic anhydride adduct. Examples of polyalkylene glycol di(meth)acrylates include polyethylene glycol di(meth)acrylate and polypropylene glycol di(meth)acrylate. Examples of alkyldiol di(meth)acrylates include butanediol di(meth)acrylate and hexanediol di(meth)acrylate.Examples of polyol poly(meth)acrylates include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. Examples of alkylene oxide-added polyol poly(meth)acrylates include alkylene oxide-added trimethylolpropane tri(meth)acrylate, alkylene oxide-added pentaerythritol tri(meth)acrylate, alkylene oxide-added pentaerythritol tetra(meth)acrylate, and alkylene oxide-added pentaerythritol hexa(meth)acrylate. Examples of vinyl alkyl ethers include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, amyl vinyl ether, and 2-ethylhexyl vinyl ether.

[0028] In particular, the (meth)acrylic acid compound or vinyl group-containing compound is more preferably (meth)acryloylmorpholine, vinylpyrrolidone, dimethylaminoalkyl (meth)acrylate, quaternary salt of dimethylaminoalkyl (meth)acrylate, dimethylaminoalkyl (meth)acrylamide, N-vinylacetamide, vinylsulfonic acid, and vinylsulfonate salts, which have antistatic properties. The amount of ethylenically unsaturated monomer is 0.02 to 100 parts by weight, preferably 0.02 to 80 parts by weight, more preferably 0.1 to 50 parts by weight, particularly preferably 0.1 to 40 parts by weight, and even more preferably 1 to 30 parts by weight, relative to the resin concentration of the water-soluble epoxy (meth)acrylate composition.

[0029] An antistatic agent may be added to the water-soluble epoxy (meth)acrylate composition. This synergistically enhances the antistatic effect of the cured polymer when crosslinked polymerization, significantly improving the antistatic effect. Furthermore, by setting the antistatic agent to, for example, the following range, a sufficient antistatic effect can be obtained without leakage of the antistatic agent from the cured polymer during crosslinked polymerization. Examples of antistatic agents include quaternary ammonium salt cationic antistatic agents, aliphatic sulfonates, higher alcohol sulfate esters, higher alcohol alkylene oxide adduct sulfate esters, higher alcohol phosphate esters, higher alcohol alkylene oxide adduct phosphate esters, at least one anionic antistatic agent selected from higher alcohol alkylene oxide adducts, at least one nonionic antistatic agent selected from higher alcohol alkylene oxide adducts, polyalkylene glycol fatty acid esters, and π-conjugated conductive polymers such as polythiophenes, polyanilines, polythiophene vinylenes, polypyrroles, and polyfurans. Among these, polythiophenes and / or polyanilines are preferred, more preferably polythiophenes, and even more preferably PEDOT / PSS. The amount of the antistatic agent is 0 to 10 parts by weight, preferably 0.01 to 5 parts by weight, more preferably 0.05 to 5 parts by weight, and particularly preferably 0.1 to 5 parts by weight, relative to the resin concentration of the water-soluble epoxy (meth)acrylate composition.

[0030] The coating composition may optionally contain an organic solvent. Examples of organic solvents include ethyl acetate, butyl acetate, toluene, xylene, methanol, ethanol, propanol, butanol, isodecyl alcohol, tridecyl alcohol, methyl isobutyl ketone, methyl ethyl ketone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cellosolves, and diacetone alcohol. However, from the viewpoint of VOC control, it is preferable that the composition does not contain an organic solvent.

[0031] The emulsion and coating composition obtained in this way are obtained as fine particles with a uniform particle size of the water-soluble epoxy (meth)acrylate composition. For example, in the emulsion and coating composition, the particle size distribution of the emulsion particles is such that the cumulative 50% particle size is 1 μm or less, and is preferably 500 nm or less. Also, the 95% cumulative diameter of the particles is such that it is 1 μm or less, and is preferably 600 nm or less. Furthermore, from the viewpoint of optical transparency, the arithmetic mean diameter is such that it is 1 μm or less, and is preferably 500 nm or less, and more preferably 100 nm or less. These values ​​were obtained by measuring the particle size distribution of the emulsion using a dynamic light scattering particle size distribution analyzer (LB-500) manufactured by Horiba, Ltd.

[0032] The coating composition containing the water-soluble epoxy (meth)acrylate composition of the present invention exhibits excellent coating film properties such as transparency, water resistance, and hardness. In addition, by further reacting the polyfunctional OH groups of the water-soluble epoxy (meth)acrylate composition with saturated or unsaturated polybasic acid anhydrides, numerous carboxyl groups can be imparted, enabling development with dilute alkaline aqueous solutions. This allows for application to solder resists with excellent properties such as heat resistance, solvent resistance, acid resistance, plating resistance, adhesion, electrical properties, and hardness. Furthermore, if the obtained emulsion is used as a coating composition, for example, as a radiation-cured coating film after coating and drying, the resulting coating film will have high water resistance, and the composition before curing will be highly transparent and water-soluble, while the cured coating film will have high water resistance and good hardness, thus obtaining a coating composition that combines seemingly contradictory properties. Furthermore, the emulsions and coating compositions containing the water-soluble epoxy (meth)acrylate composition of the present invention are substantially solvent-free, making them excellent in terms of low environmental impact. In addition, they also exhibit excellent storage stability of the emulsion and freeze-thaw stability, allowing them to withstand transportation and storage in cold regions. Furthermore, since the water-soluble epoxy (meth)acrylate composition of the present invention also has good curability (resistance to active energy rays and heat), its cured product can be suitably used in fields where cured products with high transparency, water resistance, and solvent resistance are required, and is extremely useful as a coating material for various applications such as paints, adhesives, glues, adhesives, release agents, inks, protective coatings, anchor coatings, magnetic powder coating binders, solder resists, sandblasting coatings, and printing plates.

[0033] [Coating film and cured coating film] The coating composition can be applied as a coating film to substrates such as plastics (e.g., polyolefin resins such as polyethylene, polypropylene, and polycyclopentadiene, polycarbonate, polyester, ABS resin, acrylic resin, etc.), glass, paper, wood, and cement. When the coating composition is applied to the surface of an object to be coated, its thickness is typically 50 nm to 50 μm, preferably 1 μm to 20 μm. The coating film can be crosslinked / polymerized to a cured coating film by irradiation with light rays such as far ultraviolet, ultraviolet, near ultraviolet, and infrared rays, or active energy rays such as X-rays and gamma rays, or by heating (for example, 80°C to 150°C). Before irradiating the coating film with active energy rays, it is preferable to dry it for 1 to 5 minutes, preferably 3 to 5 minutes, at a temperature above 60°C, preferably 70°C or higher, more preferably 80°C or higher and 100°C or lower. By drying at a relatively high temperature and for a short time in this way, the leveling properties of the coating film surface are improved, and the resistance to steel wool can also be enhanced. Because the cured coating film possesses high transparency, water resistance, and solvent resistance, it can be suitably used in fields where cured products with these properties are required. Specifically, it is extremely useful as a coating-forming material for various applications, such as paints, adhesives, glues, adhesive smears, release agents, inks, protective coatings, anchor coatings, magnetic powder coating binders, solder resists, sandblasting coatings, and printing plates. It also exhibits high hardness, excellent scratch resistance, and can provide antibacterial properties. Furthermore, it has excellent compatibility with anti-fogging resins and can be used not only for plastics but also as an anti-fogging coating agent for eyeglasses, mirrors, etc. Moreover, because the epoxy (meth)acrylate composition itself has a relatively small molecular weight, it can also be used as a component of water-soluble UV inkjet inks. [Examples]

[0034] The following describes in detail examples of the present invention. Specifically, the water-soluble epoxy (meth)acrylate composition of the present invention was prepared as follows. The heat residue and viscosity in the following examples were measured using the following method. (heated residue) Accurately weigh an aluminum dish (approximately 50 mm in diameter) (Ag). Place approximately 1.5 g of the sample into the aluminum dish, quickly spread it as evenly as possible using a glass rod to cover the entire bottom surface, and then accurately weigh it (Bg). Dry the aluminum dish in an electric constant-temperature drying oven at 105°C to 110°C for 3 hours. Remove the aluminum dish from the drying oven, allow it to cool to room temperature, and then accurately weigh it (Cg). Heating residue (%)=100×{(CA) / (BA)} Here, A is the weight of the aluminum dish (g), B is the weight of the aluminum dish with the sample before drying (g), and C is the weight of the aluminum dish with the sample after drying (g). (viscosity) Place approximately 400 ml of the sample into a wide-mouthed bottle, close the lid, and adjust to the temperature specified in the quality standards. Place the sample in a constant temperature bath and leave it for at least 4 hours to adjust its temperature. Place the rotor, which has been pre-heated to a predetermined temperature of ±0.2°C as specified in the quality standards, into the sample in a Type B rotational viscometer, ensuring that no air bubbles adhere to it. Attach the rotor to the viscometer and adjust the liquid level to the mark. Set the rotation speed as specified in the quality standards, rotate the viscometer, and read the needle reading after 1 minute. Viscosity (cP) = Pointer reading x X Here, X is the viscosity conversion multiplier. (According to the conversion table included with the B-type rotational viscometer)

[0035] Example 1: Water-soluble epoxy (meth)acrylate composition [EAW-1] (Manufacturing of epoxy (meth)acrylate composition) In a four-necked flask equipped with a thermometer, stirrer, and water-cooled condenser, 218 g (1.0 mol) of pyromellitic anhydride (A), 995 g (1.0 mol) of polyethylene glycol monomethyl ether (B) (weight-average molecular weight 994.9, hydroxyl value 56.4 mg KOH / g), 1.0 mol of dipentaerythritol pentaacrylate (C) (charged as a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 54.0 mg KOH / g) 1039 g), 1.8 g of 2,6-di-tert-butyl cresol, and 17.8 g of triphenylphosphine were charged, and the mixture was reacted at 65°C for 8 hours. The solution was cooled to 50°C when the acid value fell below 52. Furthermore, 1020 g (3.0 mol) of bisphenol A type epoxy resin (D) (epoxy equivalent 170 g / eq), 288 g (4.0 mol) of acrylic acid (E), and 1.8 g of methyl hydroquinone were charged. After reacting at 70°C for 3 hours, the reaction was continued at 90°C for 20 hours. The reaction was terminated when the acid value was 5 or less and the epoxy equivalent was 10,000 or more, yielding an epoxy (meth)acrylate composition (resin concentration 100%). The weight-average molecular weight of the obtained epoxy (meth)acrylate composition was 6,000. (emulsification) 300 g of the epoxy (meth)acrylate composition obtained in Example 1 was kept at 40°C, 700 g of ion-exchanged water at room temperature (25°C) was added, and the mixture was stirred (emulsified) with a paddle blade at 30°C for 2 hours to obtain the water-soluble epoxy (meth)acrylate composition [EAW-1]. The obtained water-soluble epoxy (meth)acrylate composition had a pH of 4-5, a heating residue of 30% by weight, and a viscosity of 17 mPa·s at 25°C.

[0036] Example 2: Water-soluble epoxy (meth)acrylate composition [EAW-2] (Manufacturing of epoxy (meth)acrylate composition) In a four-necked flask equipped with a thermometer, stirrer, and water-cooled condenser, 218 g (1.0 mol) of pyromellitic anhydride (A), 995 g (1.0 mol) of polyethylene glycol monomethyl ether (B) (weight-average molecular weight 994.9, hydroxyl value 56.4 mg KOH / g), 1.0 mol of dipentaerythritol pentaacrylate (C) (prepared as a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 54.0 mg KOH / g) 1039 g), 1.5 g of 2,6-di-tert-butyl cresol, and 15.4 g of triphenylphosphine were charged, and the mixture was reacted at 65°C for 8 hours. When the acid value fell below 52, ​​the mixture was cooled to 50°C. Furthermore, 680 g (2.0 mol) of bisphenol A type epoxy resin (D) (epoxy equivalent 170 g / eq), 144 g (2.0 mol) of acrylic acid (E), and 1.5 g of methyl hydroquinone were charged. After reacting at 70°C for 3 hours, the reaction was continued at 90°C for 20 hours. The reaction was terminated when the acid value was 5 or less and the epoxy equivalent was 10,000 or more, yielding an epoxy (meth)acrylate composition (resin concentration 100%). The weight-average molecular weight of the obtained epoxy (meth)acrylate composition was 8,000. (emulsification) 300 g of the epoxy (meth)acrylate composition obtained in Example 2 was kept at 40°C, 700 g of ion-exchanged water at room temperature (25°C) was added, and the mixture was stirred (emulsified) with a paddle blade at 30°C for 2 hours to obtain the water-soluble epoxy (meth)acrylate composition [EAW-2]. The obtained water-soluble epoxy (meth)acrylate composition had a pH of 4-5, a heating residue of 30% by weight, and a viscosity of 19 mPa·s at 25°C.

[0037] Example 3: Water-soluble epoxy (meth)acrylate composition [EAW-3] (Manufacturing of epoxy (meth)acrylate composition) In a four-necked flask equipped with a thermometer, stirrer, and water-cooled condenser, 218 g (1.0 mol) of pyromellitic anhydride (A), 995 g (1.0 mol) of polyethylene glycol monomethyl ether (B) (weight-average molecular weight 994.9, hydroxyl value 56.4 mg KOH / g), 1.0 mol of dipentaerythritol pentaacrylate (C) (charged as a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 54.0 mg KOH / g) 1039 g), 2 g of 2,6-di-tert-butyl cresol, and 20 g of triphenylphosphine were charged, and the mixture was reacted at 65°C for 8 hours. When the acid value fell below 52, ​​the mixture was cooled to 50°C. Furthermore, 1360 g (4.0 mol) of bisphenol A type epoxy resin (D) (epoxy equivalent 170 g / eq), 432 g (6.0 mol) of acrylic acid (E), and 2 g of methyl hydroquinone were added. After reacting at 70°C for 3 hours, the reaction was continued at 90°C for 20 hours. The reaction was terminated when the acid value was 5 or less and the epoxy equivalent was 10,000 or more, yielding an epoxy (meth)acrylate composition (100% resin concentration). The weight-average molecular weight of the obtained epoxy (meth)acrylate composition was 4,500. (emulsification) 300 g of the epoxy (meth)acrylate composition obtained in Example 3 was kept at 40°C, 700 g of ion-exchanged water at room temperature (25°C) was added, and the mixture was stirred (emulsified) with a paddle blade at 30°C for 2 hours to obtain the water-soluble epoxy (meth)acrylate composition [EAW-3]. The obtained water-soluble epoxy (meth)acrylate composition had a pH of 4-5, a heating residue of 30% by weight, and a viscosity of 11 mPa·s at 25°C.

[0038] Example 4: Water-soluble epoxy (meth)acrylate composition [EAW-4] (Manufacturing of epoxy (meth)acrylate composition) In a four-necked flask equipped with a thermometer, stirrer, and water-cooled condenser, 218 g (1.0 mol) of pyromellitic anhydride (A), 995 g (1.0 mol) of polyethylene glycol monomethyl ether (B) (weight-average molecular weight 994.9, hydroxyl value 56.4 mg KOH / g), 1.0 mol of dipentaerythritol pentaacrylate (C) (prepared as a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 54.0 mg KOH / g), 1039 g), 1.5 g of 2,6-di-tert-butyl cresol, and 15.1 g of triphenylphosphine were charged, and the mixture was reacted at 65°C for 8 hours. When the acid value fell below 52, ​​the mixture was cooled to 50°C. Furthermore, 550 g (2.5 mol) of resorcinol diglycidyl ether (D) (epoxy equivalent 110 g / eq), 216 g (3.0 mol) of acrylic acid (E), and 1.5 g of methyl hydroquinone were added. After reacting at 70°C for 3 hours, the reaction was continued at 90°C for 20 hours. The reaction was terminated when the acid value was 5 or less and the epoxy equivalent was 10,000 or more, yielding an epoxy (meth)acrylate composition (resin concentration 100%). The weight-average molecular weight of the obtained epoxy (meth)acrylate composition was 7,000. (emulsification) 200 g of the epoxy (meth)acrylate composition obtained in Example 4 was kept at 40°C, 800 g of ion-exchanged water at room temperature (25°C) was added, and the mixture was stirred (emulsified) with a paddle blade at 30°C for 2 hours to obtain the water-soluble epoxy (meth)acrylate composition [EAW-4]. The obtained water-soluble epoxy (meth)acrylate composition had a pH of 4-5, a heating residue of 20% by weight, and a viscosity of 5 mPa·s at 25°C.

[0039] Comparative Example 5: Water-soluble epoxy (meth)acrylate composition [EAW-5] (Manufacturing of epoxy (meth)acrylate composition) In a four-necked flask equipped with a thermometer, stirrer, and water-cooled condenser, 200 g (2.0 mol) of succinic anhydride, 1000 g (1.0 mol) of polyethylene glycol (weight-average molecular weight 1000), 0.9 g of 2,6-di-tert-butyl cresol, and 9.3 g of triphenylphosphine were charged, and the mixture was reacted at 65°C for 8 hours. When the acid value fell below 52, ​​the mixture was cooled to 50°C. Furthermore, 524 g (2.0 mol) of propylene glycol diglycidyl ether (epoxy equivalent 131 g / eq), 144 g (2.0 mol) of acrylic acid (E), and 0.9 g of methyl hydroquinone were added. After reacting at 70°C for 3 hours, the reaction was continued at 90°C for 20 hours. The reaction was terminated when the acid value was 5 or less and the epoxy equivalent was 10,000 or more, yielding an epoxy (meth)acrylate composition (100% resin concentration). The weight-average molecular weight of the obtained epoxy (meth)acrylate composition was 7,000. (emulsification) 300 g of the epoxy (meth)acrylate composition obtained in Comparative Example 5 was kept at 40°C, 700 g of ion-exchanged water at room temperature (25°C) was added, and the mixture was stirred (emulsified) with a paddle blade at 30°C for 2 hours to obtain the water-soluble epoxy (meth)acrylate composition [EAW-5]. The obtained water-soluble epoxy (meth)acrylate composition had a pH of 4-5, a heating residue of 30% by weight, and a viscosity of 18 mPa·s at 25°C.

[0040] Comparative Example 6: Water-soluble epoxy (meth)acrylate composition [EAW-6] (Manufacturing of epoxy (meth)acrylate composition) In a four-necked flask equipped with a thermometer, stirrer, and water-cooled condenser, 218 g (1.0 mol) of pyromellitic anhydride (A), 547 g (1.0 mol) of polyethylene glycol monomethyl ether (B) (weight-average molecular weight 546.3, hydroxyl value 102.7 mg KOH / g), 1.0 mol of dipentaerythritol pentaacrylate (C) (prepared as a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 54.0 mg KOH / g), 1039 g), 1.6 g of 2,6-di-tert-butyl cresol, and 15.6 g of triphenylphosphine were charged, and the mixture was reacted at 65°C for 8 hours. When the acid value fell below 52, ​​the mixture was cooled to 50°C. Furthermore, 1020 g (3.0 mol) of bisphenol A type epoxy resin (D) (epoxy equivalent 170 g / eq), 288 g (4.0 mol) of acrylic acid (E), and 1.6 g of methyl hydroquinone were added. After reacting at 70°C for 3 hours, the reaction was continued at 90°C for 20 hours. The reaction was terminated when the acid value was 5 or less and the epoxy equivalent was 10,000 or more, yielding an epoxy (meth)acrylate composition (resin concentration 100%). The weight-average molecular weight of the obtained epoxy (meth)acrylate composition was 5,000. (emulsification) In Comparative Example 6, 300 g of the epoxy (meth)acrylate composition was kept at 40°C, and 700 g of deionized water at room temperature (25°C) was added. The mixture was then stirred (emulsified) with a paddle blade at 30°C for 2 hours to obtain the water-soluble epoxy (meth)acrylate composition [EAW-6]. However, separation occurred immediately after stirring was stopped.

[0041] Comparative Example 7: Water-soluble epoxy (meth)acrylate composition [EAW-7] (Manufacturing of epoxy (meth)acrylate composition) The raw materials and additives with the same composition as in Example 1 were charged together and reacted at 90°C. Gelation was confirmed 5 hours after the reaction began.

[0042] Comparative Example 8: Water-dispersible epoxy (meth)acrylate composition [EAX-1] (Manufacturing of epoxy (meth)acrylate composition) In a four-necked flask equipped with a thermometer, stirrer, and water-cooled condenser, 600g of bisphenol A diglycidyl ether (Shell Chemical Co., Ltd., "Epicote 828", epoxy equivalent 170), 288g of acrylic acid, 2g of triethylamine, and 0.2g of hydroquinone were charged and reacted at 90°C to 100°C for 15 hours under stirring to obtain (a) epoxy acrylate composition with an acid value of 3.0 KOH mg / g (resin concentration 100%). (water dispersion) 100 g of deionized water and 3 g of polyoxyalkylene alkenyl ether-based reactive emulsifier (Latemul PD-430, manufactured by Kao Corporation) were added to a 500 ml four-necked flask equipped with a thermometer, reflux condenser, and stirrer, and the mixture was heated to 50°C. To this, 100 g of the epoxy (meth)acrylate composition obtained in Synthesis Example 8, which was heated to 50°C under strong stirring, was added, and stirring was continued at 1000-1200 rpm using a disperser for 30 minutes at 50°C to prepare an aqueous dispersion [EAX-1].

[0043] Comparative Example 9: Water-dispersible epoxy (meth)acrylate composition [EAX-2] (water dispersion) 100 g of deionized water and 3 g of an ether sulfate-type anionic reactive emulsifier (Asahi Denka Co., Ltd., "Adekaria Soap SE-10N") were added to a 500 ml four-necked flask equipped with a thermometer, reflux condenser, and stirrer, and the mixture was heated to 50°C. To this, 100g of a bisphenol-based epoxy (meth)acrylate composition (manufactured by Kyoeisha Chemical Co., Ltd., "Epoxy Ester 3000A") heated to 50°C under strong stirring was added, and stirring was continued at 1000-1200 rpm using a disperser for 30 minutes at 50°C to prepare an aqueous dispersion [EAX-2].

[0044] Test Example 1 (Emulsification stability) The resulting emulsion or aqueous dispersion was left to stand at room temperature and observed visually. ○: No separation or sedimentation even after being left overnight (homogeneous solution) △: After 1 hour, sedimentation occurred. ×: Separation after emulsification or dispersion. (Storage stability) The resulting emulsion or aqueous dispersion was left to stand at -5°C and 40°C and observed visually. (Freeze-thaw stability) Expose to freezing point (approximately -24°C) for 10 hours, then thaw at room temperature (23°C) for 10 hours. If this cycle is performed for three cycles and no significant changes (such as phase separation or sedimentation) are observed, and the emulsion remains stable during thawing, then the freeze-thaw stability is considered good (〇). Significant changes (such as phase separation or sedimentation) were marked with an "X".

[0045] Test Example 2 The particle size distribution of the emulsion was measured using a dynamic light scattering particle size distribution analyzer (LB-500) manufactured by Horiba, Ltd., and the particle size at 50% cumulative diameter and the 95% cumulative diameter (maximum particle diameter) were determined. The arithmetic mean diameter was calculated according to the following formula. JPEG0007874326000001.jpg25169 These results are shown in Table 1. [Table 1]

[0046] Test Example 3 In the examples and comparative examples that were evaluated as having good emulsion stability in Test Example 1, each water-soluble epoxy (meth)acrylate composition (emulsifier) ​​obtained was dissolved by adding 3% of a non-silicone leveling agent: Polyflow KL900 (manufactured by Kyoeisha Chemical Co., Ltd.) and a curing agent (F-1: photopolymerization initiator "Omnirad2959" manufactured by IGM Resins BV) (F-2: polymerization catalyst ammonium persulfate) to 100g of solids to obtain an emulsion. These emulsions were coated onto a substrate PET (hereinafter referred to as easy-adhesion polyester film, manufactured by Toyobo, Cosmoshine® A-4160, thickness 125 μm) using a bar coater #14 to a film thickness of 5 μm after drying. When (F-1) was used as the polymerization initiator, after coating each emulsion, drying and heat treatment was performed at 80°C for 5 minutes, and irradiation was performed using an electrodeless lamp H bulb at a line speed of 5.4 m / min and an irradiation dose of 600 mJ / cm². 2 , Peak illuminance: 1,500mW / cm 2 Ultraviolet irradiation was performed. When (F-2) was used as the polymerization initiator, each emulsion was coated and then dried and heat-cured at 120°C for 15 minutes. Based on this, each water-soluble epoxy (meth)acrylate composition was coated onto an easily adhesive polyester film, and the resulting coated polyester film was subjected to the following durability tests. (Coating film hardness) The pencil hardness of polyester films coated with a cured water-soluble epoxy (meth)acrylate composition was measured in accordance with JIS K5400. (Abrasion resistance) The abrasion resistance of a polyester film coated with a cured water-soluble epoxy (meth)acrylate composition was evaluated by rubbing it 10 times back and forth with steel wool (#0000) under a load of 100g. The condition of the scratches was observed visually. ○: The sample surface is completely free of scratches. ×: Scratches were found on the sample surface. (water resistance) The surface of the test piece obtained above was wiped 10 times with a cloth (Crecia Technowipe C100-S (manufactured by Nippon Paper Crecia Co., Ltd.)) soaked in deionized water, then dried for 1 hour at 25°C, and the appearance was visually evaluated. ○: No scratches on the sample surface, and no change in transparency. ×: The sample surface is whitened. (Solvent resistance) Cloths (Crecia Tech) soaked in ethanol and MEK (methyl ethyl ketone) respectively The anti-fogging film surface of the test piece obtained above using Nowip C100-S (manufactured by Nippon Paper Crecia Co., Ltd.) After wiping it 10 times, it was dried for 1 hour in a 25°C environment, and then its appearance was visually evaluated. ○: No scratches on the sample surface, and no change in transparency. ×: The sample surface is whitened. These results are shown in Table 2. [Table 2]

[0047] Test Example 4 In Test Example 3, the durability tests (scratch resistance, water resistance, and solvent resistance) were all evaluated as good (〇). The optical properties of a polyester film with a cured coating of a water-soluble epoxy (meth)acrylate composition were then evaluated. (Optical properties) The haze and total light transmittance of polyester films coated with a cured water-soluble epoxy (meth)acrylate composition were measured using a Konica Minolta CM-3600A spectrophotometer. A haze level of less than 1 and a total light transmittance of 89% or higher were considered acceptable (substrate: 89.6% or higher). The results are shown in Table 3. [Table 3] [Industrial applicability]

[0048] The method for producing a water-soluble epoxy (meth)acrylate composition and the coating composition of the present invention are extremely useful as various film-forming materials such as paints, adhesives, glues, adhesive smears, release agents, inks, protective coating agents, anchor coating agents, magnetic powder coating binders, solder resists, sandblasting films, and printing plates. Furthermore, the coating compositions of the present invention can be developed with dilute alkaline aqueous solutions and can be applied to solder resists with excellent properties such as heat resistance, solvent resistance, acid resistance, plating resistance, adhesion, electrical properties, and hardness. Moreover, the obtained coating film has good leveling properties and extremely high water resistance, and the composition before curing is highly transparent and water-soluble, while the cured coating film has high water resistance and good hardness, thus providing a coating composition that combines seemingly contradictory properties.

Claims

1. A method for producing a water-soluble epoxy (meth)acrylate composition, comprising reacting 1 mole of carboxylic acid anhydrides (A) having m acid anhydride groups with q moles of a polyethylene glycol derivative (B) containing a hydroxyl group at one end represented by formula (I) and k moles of a hydroxyl group-containing (meth)acrylate compound (C), and then reacting h moles of an epoxy compound (D) having j epoxy groups with g moles of a compound (E) having a carboxyl group and a (meth)acryloyl group, A method for producing a water-soluble epoxy (meth)acrylate composition by reacting under conditions that satisfy m ≤ q + k, m ≤ 2h, g ≥ h × j - m, 2 ≤ m ≤ 4, 0.5 ≤ q ≤ 3, 0.5 ≤ k ≤ 2, 2 ≤ j ≤ 3, and 2 ≤ h ≤ 8. H-(OCH) 2 CH 2 ) n -O-Y (I) [In the formula, Y is an alkyl group, a (meth)acryloyl group, an allyl group, or an acyl group, and n is an integer of 18 or more.]

2. A method for producing a water-soluble epoxy (meth)acrylate composition according to claim 1, wherein the one-terminated hydroxyl group-containing polyethylene glycol derivative (B) is polyethylene glycol monomethyl ether, polyethylene glycol lauryl ether, polyethylene glycol mono(meth)acrylate, or polyethylene glycol monoallyl ether.

3. A method for producing a water-soluble epoxy (meth)acrylate composition according to claim 1, wherein the hydroxyl group-containing (meth)acrylate compound (C) is a polyfunctional hydroxyalkyl (meth)acrylate or polyol (meth)acrylate having a (meth)acryloyl group.

4. A method for producing a water-soluble epoxy (meth)acrylate composition according to claim 1, wherein the epoxy compound (D) is a bisphenol-type epoxy resin, a resorcinol glycidyl ether, or a polyalkylene glycol glycidyl ether.

5. An emulsion comprising a water-soluble epoxy (meth)acrylate composition obtained by any one of claims 1 to 4.

6. A coating composition comprising a water-soluble epoxy (meth)acrylate composition obtained by any one of claims 1 to 4.

7. Furthermore, the coating composition according to claim 6 further comprises at least one of an ethylenically unsaturated monomer, a curing agent, a photopolymerization initiator, and a polymerization catalyst.

8. A coating film which is a thermoset product of a coating composition comprising the water-soluble epoxy (meth)acrylate composition described in claim 7.

9. A coating film cured by active energy ray irradiation of a coating composition comprising the water-soluble epoxy (meth)acrylate composition described in claim 7.

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