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 technology]

[0002] Conventionally, epoxy (meth)acrylates have been produced by a batch method using a reaction vessel. In particular, it is known that hydrophobic epoxy (meth)acrylates are produced by reacting a carboxyl group of a compound having a carboxyl group and a (meth)acryloyl group with an 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 a carboxylic acid anhydride such as phthalic anhydride, trimellitic anhydride, or pyromellitic anhydride (Patent Document 2). In addition, a method for producing an epoxy (meth)acrylate emulsion by using a reactive emulsifier with the epoxy (meth)acrylate obtained by the above-mentioned production method has been proposed (Patent Document 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2009 / 113609 [Patent Document 2] Japanese Patent Application Publication No. 7-50473 [Patent Document 3] JP 2000-159847 A Summary of the Invention [Problem to be solved by the invention]

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

[0005] This application includes the following inventions: (1) A method for producing a water-soluble epoxy (meth)acrylate composition, comprising reacting 1 mole of a carboxylic acid anhydride (A) having m acid anhydride groups with q moles of a polyethylene glycol derivative (B) having a hydroxyl group at one end and 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, comprising reacting under conditions satisfying m≦q+k, m≦2h, and g≧h×jm. H-(OCH 2 CH 2 ) 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 a water-soluble epoxy (meth)acrylate composition according to (1), comprising reacting under conditions satisfying 2≦m≦4, 0.5≦q≦3, 0.5≦k≦2, 2≦j≦3 and 2≦h≦8. (3) The method for producing the water-soluble epoxy (meth)acrylate composition described above, wherein the polyethylene glycol derivative (B) containing a hydroxyl group at one end 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-mentioned water-soluble epoxy (meth)acrylate composition, wherein the hydroxyl group-containing (meth)acrylate compound (C) is a hydroxyalkyl (meth)acrylate having a polyfunctional (meth)acryloyl group, a polyol (meth)acrylate, or an alkylene oxide-added polyol (meth)acrylate. (5) The method for producing a water-soluble epoxy (meth)acrylate composition as described above, 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 above method. (7) A coating composition comprising the water-soluble epoxy (meth)acrylate composition obtained by the above-mentioned method. (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) A coating film which is a thermosetting product of a coating composition containing the water-soluble epoxy (meth)acrylate composition according to (8). (10) A coating film cured by irradiating a coating composition containing the water-soluble epoxy (meth)acrylate composition according to (8) with active energy rays. Effect 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 having extremely high self-emulsifying properties, an emulsion having excellent storage stability and freeze-thaw stability, and a small emulsion particle size, an emulsion, a coating composition, and a coating film or a cured coating film. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0008] [Method for producing water-soluble epoxy (meth)acrylate composition] In the method for producing a water-soluble epoxy (meth)acrylate composition in the present 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) having a hydroxyl group at one end represented by formula (I) and k moles of a hydroxyl group-containing (meth)acrylate compound (C). Each of the compounds to be reacted may be used alone or in combination of two or more kinds.

[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, chlorendic anhydride, and methyltetrahydrophthalic anhydride; aromatic polyvalent carboxylic acid anhydrides such as trimellitic anhydride, pyromellitic anhydride, biphenyltetracarboxylic dianhydride, and benzophenonetetracarboxylic dianhydride; and polyvalent carboxylic acid anhydride derivatives associated therewith, such as 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride. The carboxylic acid anhydrides include those having m acid anhydride groups, and for example, m is preferably 2 or more. Also, m may be 10 or less, preferably 5 or less, and more preferably 4 or less.

[0010] (Polyethylene glycol derivatives containing a hydroxyl group at one end (B)) The polyethylene glycol derivative (B) having a hydroxyl group at one end is a derivative represented by the formula (I). H-(OCH 2 CH 2 ) n -OY (I) (In the formula, Y is any one of an alkyl group, a (meth)acryloyl group, an allyl group, and an acyl group, and n is an integer of 18 or more.) When Y is an alkyl group, examples of the polyethylene glycol derivatives include 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 thereof include polyethylene glycol derivatives such as polyethylene glycol monoallyl ether, polyethylene glycol-polypropylene glycol monoallyl ether, and the like. When Y is an acyl group, examples thereof include polyethylene glycol derivatives such as polyethylene glycol monolaurate, polyethylene glycol monostearate, and polyethylene glycol monooleate. Among them, Y is preferably an alkyl group or a (meth)acryloyl group, and more preferably a polyethylene glycol derivative. In this case, for example, the number of moles of ethylene oxide added, n, can be 18 to 500, preferably 18 to 100, more preferably 18 to 50, and even more preferably 20 to 45 in terms of the balance between the hydrophilic group and the hydrophobic group. By setting the number of moles of ethylene oxide added, n, in this range, stable emulsion dispersibility can be obtained, and the hardness, abrasion resistance, water resistance, and solvent resistance of the cured coating film can be improved. From another viewpoint, the polyethylene glycol derivative having a hydroxyl group at one end represented by formula (I) has a weight average molecular weight of 850 to 20,000, preferably 850 to 5,000, and more preferably 900 to 2,000. The weight average molecular weight means a weight average molecular weight calculated in terms of the molecular weight of standard polystyrene, and is measured by high performance liquid chromatography (Showa Denko K.K., "Shodex GPC system-11 type") using a column: Shodex GPC KF-806L (exclusion limit molecular weight: 2×10 7 , Separation range: 100~2×10 7 The measurement can be performed by using three series of tubes (theoretical plate number: 10,000 plates / tube, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm). By setting the weight average molecular weight within this range, stable emulsion dispersion can be obtained, and the hardness, abrasion resistance, water resistance, solvent resistance, and warm water resistance of the cured coating film can be improved. The hydroxyl value of the polyethylene glycol derivative having a hydroxyl group at one end represented by formula (I) can be 2 to 65 mgKOH / g, preferably 10 to 65 mgKOH / g, more preferably 28 to 62 mgKOH / g. By adjusting the hydroxyl value within this range, the water resistance and emulsion stability of the cured coating film can be improved.

[0011] (Hydroxyl-containing (meth)acrylate compound (C)) Examples of the hydroxyl group-containing (meth)acrylate compound include hydroxyalkyl (meth)acrylates, polyol (meth)acrylates, and alkylene oxide-added polyol (meth)acrylates. Examples of the hydroxyalkyl (meth)acrylates include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and hydroxyphenoxypropyl (meth)acrylate. Examples of the polyol (meth)acrylates include glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate. Examples of the 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 anhydrides (A) having an acid anhydride group with a polyethylene glycol derivative (B) having a hydroxyl group at one end represented by formula (I) and a hydroxyl group-containing (meth)acrylate compound (C), q moles of the polyethylene glycol derivative (B) having a hydroxyl group at one end and k moles of the hydroxyl group-containing (meth)acrylate compound (C) are reacted with 1 mole of carboxylic anhydrides (A) having m acid anhydride groups. Here, m, q, and k preferably satisfy the relationship m≦q+k. q is 0.1 or more, preferably 0.5 or more. Also, q is 10 or less, preferably 5 or less, and more preferably 3 or less. k is 0.1 or more, preferably 0.5 or more, and 5 or less, preferably 3 or less, and more preferably 2 or less. In other words, it is more preferable to react so as to simultaneously satisfy 2≦m≦4, 0.5≦q≦3, and 0.5≦k≦2. These reactions can be carried out by adding the carboxylic acid anhydrides (A), the polyethylene glycol derivative containing a hydroxyl group at one end (B) and the hydroxyl group-containing (meth)acrylate compound (C) sequentially or simultaneously, and reacting the mixture with stirring for 1 to 24 hours within a temperature range from room temperature to about 100° C. The end point of the reaction can be set, for example, from the molecular weights of the carboxylic acid anhydrides (A), the polyethylene glycol derivative containing a hydroxyl group at one end represented by formula (I) (B) and the hydroxyl group-containing (meth)acrylate compound (C).

[0013] In addition, when reacting 1 mole of a carboxylic acid anhydride (A) having m acid anhydride groups with q moles of a polyethylene glycol derivative (B) having a hydroxyl group at one end represented by formula (I) and k moles of a hydroxyl group-containing (meth)acrylate compound (C), a polymerization inhibitor, a reaction catalyst, a diluent, etc. can be used alone or as a mixture of two or more of them. Any of these known in the art can be used. As the polymerization inhibitor, a conventionally known polymerization inhibitor can be used, and examples thereof include 2,6-di-tert-butylcresol, methoquinone, hydroquinone, 1,4 naphthoquinone, phenothiazine, t-butylhydroquinone, and aluminum N-nitrophenylhydroxyamine. As the reaction catalyst, a conventionally known catalyst (initiator) can be used, and examples thereof include phosphines such as triphenylphosphine, tertiary amines such as triethylamine, quaternary ammonium salts such as tetramethylammonium salt and benzyltrimethylammonium salt, quaternary phosphonium salts, and imidazoles such as 2-methylimidazole and 2-methyl-4-methylimidazole. The amount of these to be used is not particularly limited, and may be 0.01 to 5% by weight based on 100% by weight of the reactants. As the diluent, a photopolymerizable monomer and / or an organic solvent can be used. Examples of the photopolymerizable monomer include water-soluble monomers such as N-vinylpyrrolidone, acryloylmorpholine, 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, based on 100 parts by weight of the reactants. 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 issues, energy saving, etc., active energy ray curable compositions that are cured by irradiation with active energy rays such as ultraviolet rays have been widely used instead of organic solvent-based paints. However, in practical terms, some types of such compositions require the use of a small amount of organic solvent in order to improve coating suitability. Therefore, when the above-mentioned organic solvents are not used, it is possible to meet the demand for conversion to a water-dispersed type that does not use any organic solvent, in line with VOC (volatile organic compounds) countermeasures under the recent severe social environment.

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

[0015] (Epoxy compound (D)) Examples of the epoxy compound include epoxy resins, etc. Examples of the epoxy resin include novolac epoxy resins such as bisphenol type epoxy resins, naphthalene type epoxy resins, cresol novolac type and phenol novolac type; halogenated bisphenol type epoxy resins, halogenated novolac type epoxy resins, glycidyl ester type resins of polyvalent carboxylic acids, aliphatic epoxy resins, and alicyclic epoxy resins, polyalkylene glycol diglycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, triglycidyl isocyanurate and derivatives thereof, copolymers of glycidyl group-containing unsaturated monomers such as polyglycidyl (meth)acrylate and glycidyl (meth)acrylate with other unsaturated monomers, and the like. The epoxy compound may have j epoxy groups. For example, j may be 1, but is preferably 2 or more. Also, j may be 10 or less, preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less.

[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, mesaconic acid, etc. It is sufficient that the compound has at least one carboxyl group and at least one (meth)acryloyl group.

[0017] When the above-mentioned reactant is reacted 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 above-mentioned reactant (1+q+k) moles are reacted 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. 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 more preferably 2 or more and less than 5. When m is 2 to 4 and j is 2 or 3, g can be 0 to 22, and is preferably 2 to 20, more preferably 2 to 14, further preferably 2 to 12, and even more preferably 2 to 4. In other words, it is preferable to carry out the reaction so as to simultaneously satisfy, in addition to 2≦m≦4, 0.5≦q≦3, and 0.5≦k≦2, 2≦j≦3, and 2≦h≦8. In addition, in this reaction, a polymerization inhibitor, a reaction catalyst, a diluent, etc. may be used either alone or as a mixture of two or more of them. Any of these known in the art may be used.

[0018] [Water-soluble epoxy (meth)acrylate composition] In this way, a water-soluble epoxy (meth)acrylate composition can be obtained by reacting 1 mole of a carboxylic anhydride (A) having m acid anhydride groups with q moles of a polyethylene glycol derivative (B) having 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 the resulting reaction 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 epoxy (meth)acrylate compound (C) is bonded to the hydroxyl group-containing polyethylene glycol derivative (B) and the resulting carboxyl group reacts with some of the epoxy groups of the epoxy compound (D), while the other epoxy groups react with the carboxyl groups of the compound (E) having a (meth)acryloyl group, so that the polyethylene glycol derivative (B) having a hydroxyl group at one end is bonded to the carboxylic anhydride in a pendant manner, and the hydrophilic and hydrophobic groups in the molecule can be balanced, and the water-soluble epoxy (meth)acrylate composition obtained by the present invention can exhibit extremely good self-emulsifying properties. In addition, since the composition does not substantially contain an organic solvent, the burden on the environment can be reduced. Furthermore, the water-soluble epoxy (meth)acrylate composition obtained can be made into a nonionic emulsion, and even when various additives are added to a coating composition or the like, the inhibition of the emulsion properties such as aggregation, precipitation, and separation can be prevented. On the other hand, when the above-mentioned components (A) to (E) are reacted at once, the reaction between the acid anhydride group and the hydroxyl group, the reaction between the acid anhydride group and the epoxy group, the reaction between the carboxyl group and the epoxy group, and the reaction between the hydroxyl group and the acid anhydride group generated by the reaction between the carboxyl group and the epoxy group proceed simultaneously, causing the balance of the pendant bonds to be lost, resulting in a compound having a crosslinked structure, and gelation often occurring. When gelation occurs, not only is the reaction unable to proceed stably, but the resulting reaction product becomes difficult to dissolve in water. Similarly, if the relationship between the number and moles of functional groups in each component deviates from the above-mentioned conditions, the balance of the pendant bonds is lost, causing gelation or water insolubility. 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 water-soluble epoxy (meth)acrylate composition produced deteriorates.

[0019] The emulsion and coating composition of the present invention are water-soluble and have high solvent resistance and hardness, and can form a functionally excellent cured coating film. Here, water-soluble means that when water is added to the epoxy (meth)acrylate composition, separation does not occur, no sediment occurs even after leaving for 1 hour, and further, no separation or sediment occurs even after leaving overnight. In particular, the absence of separation or sedimentation is preferably achieved under the conditions described in the examples. In other words, the emulsion obtained by emulsifying using the above-mentioned emulsification method (e.g., phase inversion emulsification) has a relatively small average particle size of 500 nm or less and is stable for a long period of time (no secondary aggregation occurs), that is, has high storage stability (-5°C, 40°C).In addition, it also has excellent freeze-thaw stability.

[0020] [Emulsions and coating compositions] The obtained water-soluble epoxy (meth)acrylate composition has self-emulsifying properties and can be developed with a dilute aqueous alkali solution. It also 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-mentioned production method can be used as a coating composition as it is, but for example, by adding water to the water-soluble epoxy (meth)acrylate composition, it can be used as a coating composition as an emulsion, that is, as an emulsion. Also, various additives and the like may be added to prepare the coating composition. For this purpose, water is first added to the water-soluble epoxy (meth)acrylate composition obtained above all at once or gradually. At this time, the obtained water-soluble epoxy (meth)acrylate composition is preferably maintained at a temperature range of, for example, 20°C to 40°C, and the temperature of the water to be added is also adjusted to the same range, more preferably to a temperature range of 15°C to 40°C or 30°C to 40°C. The water to be added may be tap water, deionized water, ion-exchanged water, distilled water, or other water. The water is preferably added in portions or all at once. In the case of portioned addition, the amount of water added at one time is, for example, 100% by weight to 200% by weight, preferably 150% by weight to 200% by weight of the mass of the water-soluble epoxy (meth)acrylate composition. The amount of water added is preferably an amount that results in a resin concentration of 50% by weight or less, more preferably 35% by weight to 45% by weight, and even more preferably 20% by weight to 40% by weight.

[0021] Next, the mixture of water and the water-soluble epoxy (meth)acrylate composition is stirred. For example, any method known in the art may be used for stirring, at the same time as the addition of water. Stirring may be performed using a stirrer, disperser, turbine blade, or Max Blend blade. However, since the water-soluble epoxy (meth)acrylate composition has high viscosity at the emulsification temperature (below the cloud point), it is preferable to use a stirring blade that has a small power load when water is added. As the stirring blade, for example, a paddle blade or an anchor blade can be used. The paddle blade can be disposed near the interface between the water-soluble epoxy (meth)acrylate composition and water or slightly on the water side from the interface, and may have only one blade or may have two or more blades in multiple stages. For stirring, the rotation speed may be 10 rpm to 10,000 rpm, but since the water-soluble epoxy (meth)acrylate composition has good self-emulsification properties, the rotation speed is preferably 500 rpm or less, more preferably 200 rpm or less, and particularly preferably 10 rpm to 300 rpm or 10 rpm to 100 rpm. It is preferable to continue stirring even after the addition of water is completed. In this case, as the power load decreases as the emulsification progresses, it is preferable to gradually increase the rotation speed and continue stirring until a uniform emulsified state is achieved.

[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 assistants, fillers, dyes and pigments, oils, plasticizers, waxes, drying agents, dispersants, wetting agents, emulsifiers, gelling agents, stabilizers, defoamers, thixotropic agents, antioxidants, flame retardants, antistatic agents, fillers, reinforcing agents, matting agents, crosslinking agents, etc. Any of the additives commonly used in the field may be used. These components may be added simultaneously or sequentially to the water-soluble epoxy (meth)acrylate composition and mixed. Leveling agents play a role in removing surface popping and craters during film coating, and are broadly classified into silicone-based leveling agents and non-silicone-based leveling agents. The characteristic of silicone-based leveling agents is that they orient on the coating surface and exert a leveling effect by lowering the surface tension of the coating surface. The effect of lowering the surface tension is large, a high leveling effect is obtained, and repelling and dents caused by low surface tension substances are improved. Next, the characteristic of non-silicone-based leveling agents, for example, acrylic polymer-based leveling agents, is that they orient on the coating surface relatively like silicone-based agents, and delay the allowable leveling time by controlling the increase in viscosity due to solvent evaporation. Furthermore, they orient on the surface, slightly lowering and uniforming the surface tension of the coating surface, thereby exerting a leveling effect. For example, examples of water-based silicone leveling agents that can be used include TEGO Glide 482 manufactured by Evonik, BYK-3456 and BYK-3760 manufactured by BYK-Chemie, and Polyflow KL401, KL402, and Polyflow KL100 manufactured by Kyoeisha Chemical. Examples of water-based non-silicone leveling agents that can be used include BYK ETOL-AQ and BYK ETOL-WS manufactured by BYK-Chemie, and Polyflow WS, Polyflow WS-314, and Polyflow KL900 manufactured by Kyoeisha Chemical. The leveling agent is contained in an amount of 0.1% by weight to 10% by weight, preferably 0.5% by weight to 5% by weight, based on the resin content concentration. As the curing agent, a radical polymerization initiator that causes addition polymerization of vinyl monomers by radical decomposition with heat or a reducing substance is suitable. For example, water-soluble persulfates, peroxides, azobis compounds, etc. are listed. Specific 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). Among them, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]tetrahydrate (trade name: VA-057, Fujifilm Wako Pure Chemical Industries, Ltd.), N,N'-bis(2-hydroxyethyl)-2,2'-dimethyl-2,2'-diazenediyldipropanamide (trade name: VA-086, Fujifilm Wako Pure Chemical Industries, Ltd.), bis[2-(4,5-dihydro-1H-imidazol-2-yl)propan-2-yl]diazene (trade name: VA-061, Fujifilm Wako Pure Chemical Industries, Ltd.), azobisisobutyric acid amidine hydrochloride (trade name: V-50, Fujifilm Wako Pure Chemical Industries, Ltd.), (E)-1,2 -bis[2-(4,5-dihydro-1H-imidazol-2-yl)propan-2-yl]diazene (trade name: VA-061, Fujifilm Wako Pure Chemical Industries, Ltd.), ]Preferred are water-soluble azo polymerization initiators such as diazene dihydrochloride (trade name: VA-044, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and azobiscyanovaleric acid (trade name: V-501, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.), and water-soluble organic peroxides such as tert-butyl hydroperoxide (trade name: Perbutyl H, manufactured by NOF Corporation). The amount of the curing agent is 0.001 to 10 parts by mass, preferably 0.01 to 10 parts by mass, more preferably 0.05 to 8 parts by mass, and further preferably 0.6 to 5 parts by mass, based on the resin concentration.

[0023] By adding a photopolymerization initiator to the epoxy (meth)acrylate, the epoxy (meth)acrylate and optionally the ethylenically unsaturated monomer are crosslinked and / or polymerized upon irradiation with active energy rays, such as ultraviolet rays, 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 by the action of light, and examples thereof include 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-hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and benzyl dimethyl Ketals, 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, dibenzosuberone, 2-ethylanthraquinone, 4',4"-diethylisophthalophenone, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, α-acyloxime ester, acylphosphine oxide, methylphenyl glyoxylate, benzil, 9,10-phenanthrenequinone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, and the like.

[0025] In particular, in order to make the water-soluble epoxy (meth)acrylate composition function better, it is preferable to use a photopolymerization initiator having water-solubility or water-dispersibility. Examples of such photopolymerization initiators include 2-(3-dimethylamino-2-hydroxypropoxy)-3,4-dimethyl-9H-thioxanthone-9-one methchloride (manufactured by Octel Chemicals, "Quantacure QTX"), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (manufactured by Ciba Specialty Chemicals, "Irgacure 2959"), etc., and among them, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (manufactured by Ciba Specialty Chemicals, "Irgacure 2959" and manufactured by IGM Resins BV, "Omnirad2959") is more preferable. The photopolymerization initiator is used in an amount of 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, based on the resin concentration of the water-soluble epoxy (meth)acrylate composition.

[0026] In addition, a photopolymerization initiator assistant may be used together with the photopolymerization initiator. Examples of the photopolymerization initiator assistant include triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler's ketone), 4,4'-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, 4-dimethylaminobenzoic acid ethyl, 4-dimethylaminobenzoic acid (n-butoxy)ethyl, 4-dimethylaminobenzoic acid isoamyl, 4-dimethylaminobenzoic acid 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 acrylic acid amides, 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, alkyl diol di(meth)acrylates, polyol poly(meth)acrylates, and alkylene oxide-added polyol poly(meth)acrylates. Examples of vinyl group-containing compounds include vinyl acetate, N-vinyl acetamide, vinyl pyrrolidone, vinyl alkyl ethers, vinyl sulfonic acid, and salts of vinyl sulfonic acid. These may be used alone or in combination of two or more. Examples of acrylic acid amides include (meth)acryloyl morpholine and dimethylamino alkyl (meth)acrylamide. Examples of amino alkyl (meth)acrylates include diethylamino ethyl (meth)acrylate. Examples of quaternary salts of amino alkyl (meth)acrylates include alkyloyl amino propyl dimethyl-2-hydroxyethyl ammonium salt. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, etc. Examples of alkoxy polyalkylene glycol (meth)acrylates include methoxy polyethylene glycol (meth)acrylate, methoxy polypropylene glycol (meth)acrylate, etc. Examples of hydroxy alkyl (meth)acrylates include hydroxy ethyl (meth)acrylate, hydroxy propyl (meth)acrylate, etc. Examples of the acid anhydride adduct 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 alkyl diol di(meth)acrylates include butane diol di(meth)acrylate and hexane diol 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] Among these, the (meth)acrylic acid compound or the vinyl group-containing compound is more preferably (meth)acryloylmorpholine, vinylpyrrolidone, dimethylaminoalkyl (meth)acrylate, a quaternary salt of dimethylaminoalkyl (meth)acrylate, dimethylaminoalkyl (meth)acrylamide, N-vinylacetamide, vinylsulfonic acid, or a vinylsulfonate salt, which have antistatic properties. The ethylenically unsaturated monomer is used in an amount of 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, based on 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 acts synergistically with the antistatic effect of the cured polymer when crosslinked, and the antistatic effect is significantly improved. By setting the amount of the antistatic agent within the following range, for example, the antistatic agent is not lost from the cured polymer when crosslinked, and a sufficient antistatic effect can be obtained. Examples of the antistatic agent include cationic antistatic agents of quaternary ammonium salts, aliphatic sulfonates, higher alcohol sulfates, higher alcohol alkylene oxide adduct sulfates, higher alcohol phosphates, and higher alcohol alkylene oxide adduct phosphates, and at least one anionic antistatic agent selected from higher alcohol alkylene oxide adducts and polyalkylene glycol fatty acid esters, and examples of the π-conjugated conductive polymers include 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 antistatic agent is used in an amount of 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 contain an organic solvent as necessary. Examples of the organic solvent 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 countermeasures, it is preferable that the coating composition does not contain an organic solvent.

[0031] The emulsion and coating composition thus obtained are obtained as fine particles of a water-soluble epoxy (meth)acrylate composition having a uniform particle size. For example, in the emulsion and coating composition, in the particle size distribution of the emulsion particles, the particle size of 50% of the particles may be 1 μm or less, and preferably 500 nm or less. In addition, the particle size of 95% of the particles may be 1 μm or less, and preferably 600 nm or less. Furthermore, from the viewpoint of optical transparency, the arithmetic mean diameter may be 1 μm or less, and 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 measuring device (LB-500) manufactured by Horiba, Ltd.

[0032] The coating composition containing the water-soluble epoxy (meth)acrylate composition of the present invention exhibits excellent effects in terms of coating film physical properties such as transparency, water resistance, hardness, etc. In addition, by further reacting the polyfunctional OH group of the water-soluble epoxy (meth)acrylate composition with a saturated or unsaturated polybasic acid anhydride, a large number of carboxyl groups can be imparted, which enables development with a dilute alkaline aqueous solution and allows the composition to be applied to a solder resist having excellent properties such as heat resistance, solvent resistance, acid resistance, plating resistance, adhesion, electrical properties, and hardness. Furthermore, when the obtained emulsion is used as a coating composition, for example, after application and drying to form a radiation-cured coating film, the obtained coating film has high water resistance. It is possible to obtain a coating composition that has contradictory properties in that the composition before curing is highly transparent and water-soluble, while after curing, the coating film has high water resistance and good hardness. Furthermore, the emulsion and coating composition containing the water-soluble epoxy (meth)acrylate composition of the present invention are substantially solvent-free and therefore have excellent environmental impact, as well as excellent storage stability of the emulsion and freeze-thaw stability that can withstand transportation and storage in cold regions. In addition, since the water-soluble epoxy (meth)acrylate composition of the present invention has good curability (active energy rays, heat), the cured product thereof can be suitably used in fields where a cured product having high transparency, water resistance, and solvent resistance is required, and is extremely useful as a material for forming various coating films, such as paints, pressure sensitive adhesives, adhesives, tacky adhesives, release agents, inks, protective coating agents, anchor coating agents, magnetic powder coating binders, solder resists, coatings for sandblasting, and printing plates.

[0033] [Coating film and cured coating film] The coating composition can be applied to a substrate such as plastics (e.g., polyolefin resins such as polyethylene, polypropylene, and polycyclopentadiene, polycarbonate, polyester, ABS resin, and acrylic resin), glass, paper, wood, and cement to form a coating film. When the coating composition is applied to the surface of an object to be coated, the thickness is 50 nm to 50 μm, and preferably 1 μm to 20 μm. The coating film can be crosslinked / polymerized to a cured coating film by irradiating it with light such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays, or active energy rays such as X-rays and gamma rays, or by heating (for example, at 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 of more than 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 in such a short time, the leveling property of the surface of the coating film is particularly improved, and the steel wool resistance can also be improved. The cured coating film has high transparency, water resistance, and solvent resistance, and can be suitably used in fields where a cured product with these properties is required. Specifically, it is very useful as a material for forming various coatings, such as paints, pressure sensitive adhesives, adhesives, tackifiers, release agents, inks, protective coatings, anchor coatings, magnetic powder coating binders, solder resists, sandblasting coatings, and printing plates. It also has high hardness, excellent scratch resistance, and can be given antibacterial properties. Furthermore, it has excellent compatibility with anti-fog resins, and can be used as an anti-fog coating agent not only for plastics but also for glasses, mirrors, etc. Furthermore, since the molecular weight of the epoxy (meth)acrylate composition itself is relatively small, it can also be used as a component of water-soluble UV inkjet ink. EXAMPLES

[0034] Examples of the present invention will be described in detail below. Specifically, the water-soluble epoxy (meth)acrylate composition of the present invention was produced as follows. In the following examples, the heating residue and viscosity were measured by the following methods. (heated residue) Accurately measure the weight of an aluminum dish (approximately 50 mm in diameter) (Ag), place approximately 1.5 g of the sample on the aluminum dish, quickly spread it as evenly as possible over the entire bottom surface with a glass rod, and then accurately measure its weight (Bg). Dry the aluminum dish in an electric constant temperature dryer at 105°C to 110°C for 3 hours. Remove the aluminum dish from the dryer, allow it to cool to room temperature, and then accurately measure its weight (Cg). Heating residue (%)=100×{(CA) / (BA)} Here, A is the weight of the aluminum plate (g), B is the weight of the aluminum plate including the sample before drying (g), and C is the weight of the aluminum plate including the sample after drying (g). (viscosity) Put about 400 ml of the sample into a wide-mouthed bottle, cover it, and adjust the temperature to the "quality standard" The sample is placed in a constant temperature bath and left for at least 4 hours to adjust the temperature. A rotor "specified in the quality standard" that has been kept at a specified temperature of ±0.2°C is placed in the sample in a B-type rotational viscometer, taking care not to allow air bubbles to adhere to the rotor, and the liquid level is aligned with the marked line. The rotation speed is set to "specified in the quality standard," the viscometer is rotated, and the pointer reading is read after 1 minute. Viscosity (cP) = Pointer reading x X Here, X is the viscosity conversion multiplier (according to the conversion table attached to the B-type rotational viscometer).

[0035] Example 1: Water-soluble epoxy (meth)acrylate composition [EAW-1] (Production of Epoxy (Meth)acrylate Composition) Into a four-neck flask equipped with a thermometer, a stirrer, and a 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) (1.0 mol) (1039 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 54.0 mg KOH / g)), 1.8 g of 2,6-di-tert-butylcresol, and 17.8 g of triphenylphosphine were charged, and the mixture was reacted at 65° C. for 8 hours. When the acid value reached 52 or less, the mixture was cooled to 50°C. In addition, 1020g (3.0 mol) of bisphenol A type epoxy resin (D) (epoxy equivalent 170g / eq), 288g (4.0 mol) of acrylic acid (E), and 1.8g 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, and an epoxy (meth)acrylate composition was obtained (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, and 700 g of ion-exchanged water at room temperature (25°C) was added. The mixture was stirred (emulsified) with a paddle impeller at 30°C for 2 hours to obtain a water-soluble epoxy (meth)acrylate composition [EAW-1]. The resulting water-soluble epoxy (meth)acrylate composition had a pH of 4 to 5, a heating residue of 30% by weight, and a viscosity at 25°C of 17 mPa·s.

[0036] Example 2: Water-soluble epoxy (meth)acrylate composition [EAW-2] (Production of Epoxy (Meth)acrylate Composition) In a four-neck flask equipped with a thermometer, a stirrer, and a 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) (1.0 mol) (mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 54.0 mg KOH / g) 1039 g), 1.5 g of 2,6-di-tert-butylcresol, and 15.4 g of triphenylphosphine were charged, and then reacted at 65 ° C. for 8 hours. When the acid value became 52 or less, it was cooled to 50 ° C. In addition, 680g (2.0 mol) of bisphenol A type epoxy resin (D) (epoxy equivalent 170g / eq), 144g (2.0 mol) of acrylic acid (E), and 1.5g of methylhydroquinone 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, and an epoxy (meth)acrylate composition was obtained (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, and 700 g of ion-exchanged water at room temperature (25°C) was added. The mixture was stirred (emulsified) with a paddle impeller at 30°C for 2 hours to obtain a water-soluble epoxy (meth)acrylate composition [EAW-2]. The resulting water-soluble epoxy (meth)acrylate composition had a pH of 4 to 5, a heating residue of 30% by weight, and a viscosity at 25°C of 19 mPa·s.

[0037] Example 3: Water-soluble epoxy (meth)acrylate composition [EAW-3] (Production of Epoxy (Meth)acrylate Composition) In a four-neck flask equipped with a thermometer, a stirrer, and a 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) (1.0 mol) (mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 54.0 mg KOH / g) 1039 g), 2,6-di-tert-butylcresol 2 g, and triphenylphosphine 20 g were charged, and then reacted at 65 ° C. for 8 hours. When the acid value became 52 or less, it was cooled to 50 ° C. In addition, 1360g (4.0 mol) of bisphenol A type epoxy resin (D) (epoxy equivalent 170g / eq), 432g (6.0 mol) of acrylic acid (E), and 2g 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, and an epoxy (meth)acrylate composition was obtained (resin concentration 100%). 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, and 700 g of ion-exchanged water at room temperature (25°C) was added. The mixture was stirred (emulsified) with a paddle impeller at 30°C for 2 hours to obtain a water-soluble epoxy (meth)acrylate composition [EAW-3]. The resulting water-soluble epoxy (meth)acrylate composition had a pH of 4 to 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] (Production of Epoxy (Meth)acrylate Composition) In a four-neck flask equipped with a thermometer, a stirrer, and a 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) (1.0 mol) (mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 54.0 mg KOH / g) 1039 g), 1.5 g of 2,6-di-tert-butylcresol, and 15.1 g of triphenylphosphine were charged, and then reacted at 65 ° C. for 8 hours. When the acid value became 52 or less, it was cooled to 50 ° C. In addition, 550g (2.5 mol) of resorcinol diglycidyl ether (D) (epoxy equivalent 110g / eq), 216g (3.0 mol) of acrylic acid (E), and 1.5g 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, and an epoxy (meth)acrylate composition was obtained (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, and 800 g of ion-exchanged water at room temperature (25°C) was added. The mixture was stirred (emulsified) with a paddle impeller at 30°C for 2 hours to obtain a water-soluble epoxy (meth)acrylate composition [EAW-4]. The resulting water-soluble epoxy (meth)acrylate composition had a pH of 4 to 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] (Production of Epoxy (Meth)acrylate Composition) In a four-neck flask equipped with a thermometer, a stirrer, and a 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-butylcresol, and 9.3 g of triphenylphosphine were charged and reacted at 65° C. for 8 hours. When the acid value became 52 or less, the mixture was cooled to 50° C. In addition, 524g (2.0 mol) of propylene glycol diglycidyl ether (epoxy equivalent 131g / eq), 144g (2.0 mol) of acrylic acid (E), and 0.9g 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, and an epoxy (meth)acrylate composition was obtained (resin concentration 100%). 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, and 700 g of ion-exchanged water at room temperature (25°C) was added. The mixture was stirred (emulsified) for 2 hours with a paddle impeller at 30°C to obtain a water-soluble epoxy (meth)acrylate composition [EAW-5]. The resulting water-soluble epoxy (meth)acrylate composition had a pH of 4 to 5, a heating residue of 30% by weight, and a viscosity at 25°C of 18 mPa·s.

[0040] Comparative Example 6: Water-soluble epoxy (meth)acrylate composition [EAW-6] (Production of Epoxy (Meth)acrylate Composition) In a four-neck flask equipped with a thermometer, a stirrer, and a 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) (1.0 mol) (mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 54.0 mg KOH / g) 1039 g), 1.6 g of 2,6-di-tert-butylcresol, and 15.6 g of triphenylphosphine were charged, and then reacted at 65 ° C. for 8 hours. When the acid value became 52 or less, it was cooled to 50 ° C. In addition, 1020g (3.0 mol) of bisphenol A type epoxy resin (D) (epoxy equivalent 170g / eq), 288g (4.0 mol) of acrylic acid (E), and 1.6g of methylhydroquinone 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, and an epoxy (meth)acrylate composition was obtained (resin concentration 100%). The weight average molecular weight of the obtained epoxy (meth)acrylate composition was 5,000. (emulsification) 300 g of the epoxy (meth)acrylate composition obtained in Comparative Example 6 was kept at 40°C, and 700 g of ion-exchanged water at room temperature (25°C) was added. The mixture was stirred (emulsified) with a paddle impeller at 30°C for 2 hours to obtain a water-soluble epoxy (meth)acrylate composition [EAW-6]. However, the mixture separated immediately after stirring was stopped.

[0041] Comparative Example 7: Water-soluble epoxy (meth)acrylate composition [EAW-7] (Production of Epoxy (Meth)acrylate Composition) The raw materials and additives having the same composition as in Example 1 were charged all at once, and then reacted at 90°C. Gelation was observed 5 hours after the start of the reaction.

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

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

[0044] Test Example 1 (Emulsification stability) The resulting emulsion or aqueous dispersion was allowed to stand at room temperature and observed visually. 〇: No separation or sediment even after leaving overnight (homogeneous solution) △: After 1 hour, sedimentation occurred ×: Separation after emulsification or dispersion operation (Storage stability) The resulting emulsion or aqueous dispersion was allowed to stand at −5° C. and 40° C., and was visually observed. (Freeze-thaw stability) Expose to freezing temperatures (approximately -24°C) for 10 hours, then thaw at room temperature (23°C) for 10 hours. This cycle was repeated three times, and if no significant changes (phase separation or sedimentation) were observed and the emulsion maintained a stable emulsion state upon thawing, the freeze-thaw stability was rated as good (good). When a significant change (phase separation or occurrence of sediment) was observed, it was marked as ×.

[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 of the cumulative 50% of the particles and the cumulative diameter of the 95% of the particles (maximum particle size value) were calculated. The arithmetic mean diameter was calculated according to the following formula. JPEG2025085432000001.jpg25169The results are shown in Table 1. [Table 1]

[0046] Test Example 3 For each water-soluble epoxy (meth) acrylate composition (emulsion) obtained in the examples and comparative examples in which the emulsion stability was evaluated as good in Test Example 1, 3% of a non-silicon leveling agent: Polyflow KL900 (manufactured by Kyoeisha Chemical) and a curing agent (F-1: photopolymerization initiator "Omnirad2959" manufactured by IGM Resins BV) (F-2: polymerization catalyst ammonium persulfate) were added and dissolved to obtain an emulsion, and these emulsions were applied to a substrate PET (hereinafter, an easily adhesive polyester film, manufactured by Toyobo, Cosmoshine (registered trademark) A-4160, thickness 125 μm) using a bar coater #14 so that the film thickness after drying was 5 μm. When (F-1) was used as the polymerization initiator, after coating of each emulsion, drying and heat treatment were performed at 80°C for 5 minutes, and then the electrodeless lamp H bulb was used, with a line speed of 5.4 m / min and an irradiation dose of 600 mJ / cm. 2 , Peak illuminance: 1,500mW / cm 2 UV irradiation was performed. When (F-2) was used as the polymerization initiator, after coating of each emulsion, drying and heat curing were carried out at 120° C. for 15 minutes. Each water-soluble epoxy (meth)acrylate composition was coated on a highly adhesive polyester film, and the polyester film with the coating film obtained by curing was subjected to the following durability tests. (Coating film hardness) The polyester film having the cured coating of the water-soluble epoxy (meth)acrylate composition was measured for pencil hardness in accordance with JIS K5400. (Abrasion resistance) The polyester film having the cured coating of the water-soluble epoxy (meth)acrylate composition was rubbed 10 times with steel wool (#0000) under a load of 100 g to evaluate the scratch resistance. The state of scratches was visually observed. ○: No scratches on the sample surface ×: Scratches were observed on the sample surface. (water resistance) The membrane surface of the test piece obtained above was wiped 10 times with a cloth soaked in ion-exchanged water (Crecia Techno Wipe C100-S, manufactured by Nippon Paper Crecia Co., Ltd.), and then dried for 1 hour in a 25°C environment, after which the appearance was visually evaluated. 〇: No scratches on the sample surface, no change in transparency ×: The sample surface is whitened. (Solvent resistance) Ethanol and MEK (methyl ethyl ketone) soaked cloth (Creciatech) The anti-fog film surface of the test piece obtained above was wiped with Nowipe C100-S (manufactured by Nippon Paper Crecia Co., Ltd.). After wiping 10 times, the sample was dried at 25°C for 1 hour, and then the appearance was visually evaluated. 〇: No scratches on the sample surface, no change in transparency ×: The sample surface is whitened. The results are shown in Table 2. [Table 2]

[0047] Test Example 4 The optical properties of the polyester film having the cured coating film of the water-soluble epoxy (meth)acrylate composition, which was rated as good (◯) in all durability tests (abrasion resistance, water resistance, and solvent resistance) in Test Example 3, were evaluated. (Optical properties) The haze and total light transmittance of the polyester film having the cured coating of the water-soluble epoxy (meth)acrylate composition were measured using a spectrophotometer CM-3600A manufactured by Konica Minolta. A haze of less than 1 and a total light transmittance of 89% or more were considered to be acceptable (substrate: 89.6% or higher). The results are shown in Table 3. [Table 3] [Industrial Applicability]

[0048] The method for producing the water-soluble epoxy (meth)acrylate composition and the coating composition of the present invention are very useful as various film-forming materials such as paints, adhesives, adhesives, tackifiers, release agents, inks, protective coatings, anchor coatings, magnetic powder coating binders, solder resists, sandblasting films, printing plates, etc. The coating composition of the present invention can be developed with a dilute alkaline aqueous solution and can be applied to solder resists excellent in various properties such as heat resistance, solvent resistance, acid resistance, plating resistance, adhesion, electrical properties, and hardness. Furthermore, the obtained coating film has good leveling properties and extremely high water resistance, and the composition before curing has high transparency and is water-soluble, while the coating film after curing has high water resistance and good hardness, which are contradictory properties.

Claims

1. A method for producing a water-soluble epoxy (meth)acrylate composition, comprising reacting 1 mole of a carboxylic acid anhydride (A) having m acid anhydride groups with q moles of a polyethylene glycol derivative (B) having a hydroxyl group at one end and 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, comprising reacting under conditions satisfying m≦q+k, m≦2h, and g≧h×j−m. 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. 2. The method for producing a water-soluble epoxy (meth)acrylate composition according to claim 1, wherein the reaction is carried out under conditions satisfying 2≦m≦4, 0.5≦q≦3, 0.5≦k≦2, 2≦j≦3 and 2≦h≦8.

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

4. 2. The 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 hydroxyalkyl (meth)acrylate having a multifunctional (meth)acryloyl group, a polyol (meth)acrylate, or an alkylene oxide-added polyol (meth)acrylate.

5. 2. The 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.

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

7. A coating composition comprising the water-soluble epoxy (meth)acrylate composition obtained by the method of any one of claims 1 to 5.

8. The coating composition of claim 7, further comprising at least one of an ethylenically unsaturated monomer, a curing agent, a photopolymerization initiator, and a polymerization catalyst.

9. A coating film which is a thermosetting product of a coating composition comprising the water-soluble epoxy (meth)acrylate composition according to claim 8.

10. A coating film cured by irradiation with active energy rays of a coating composition comprising the water-soluble epoxy (meth)acrylate composition according to claim 8.

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