Active energy ray-curable composition

Abstract

To provide a highly transparent active energy ray-curable composition which can be completely cured even with long-wavelength light rays having a wavelength of 350 nm or more and can obtain a cured product which has high safety, durability and transparency and causes no odor or bleed-out with little residual unreacted material or low molecular weight decomposition products and to provide molded products for various applications using the same.SOLUTION: There is provided an active energy ray-curable composition which comprises (A) a polymerizable photoinitiator having one or more benzophenone groups and one or more ethylenically unsaturated groups per molecule and (B) a polymerizable compound having one or more ethylenically unsaturated groups per molecule (excluding A), wherein the content of components having a molecular weight of less than 1000 in the cured product is less than 10%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an active energy ray-curable composition, an active energy ray-curable pressure-sensitive adhesive, adhesive, sealant, ink, paint, coating agent, dental material, or cosmetic material containing the same, and a cured product obtained by curing the composition or the like. [Background technology]

[0002] Photocuring reactions using active energy rays such as ultraviolet (UV) rays generally involve irradiating a composition containing a photopolymerization initiator with light to generate radicals (radical type) or ions (cation type or anion type), polymerizing raw materials having unsaturated groups or epoxy groups, and solidifying (curing) the liquid composition in a short time, and are used in a wide range of fields such as paints and coating agents, adhesives and glues, elastomer materials, inkjet inks, sealing materials and sealants, dental hygiene materials, optical materials, etc. In particular, from the viewpoint of being able to harden at any location or shape, they are being widely used as nail cosmetics such as gel nails, and as a material for three-dimensional photo-modeling in 3D printers.

[0003] Among them, photocurable resin compositions using radical photopolymerization initiators have high curability and are widely used because they can realize a wide range of physical properties by combining general-purpose monofunctional or polyfunctional (meth)acrylic monomers, oligomers or polymers with (meth)acrylate groups, etc. In recent years, along with the widespread use of UV-curable inks and paints, the size of UV curing devices has increased, and there has been an increasing demand for improved safety of light sources, such as preventing the emission of ultraviolet rays with wavelengths of 315 nm or less, known as UV-B and UV-C, which are considered to be harmful to the human body, and restrictions on the use of high-pressure mercury lamps under the Minamata Convention, and light sources such as mercury-free lamps, LED lamps, and black lights have been proposed. However, the main output rays of these light sources are 365 nm (black light, UV-LED), 385 nm (UV-LED) and 405 nm (LED lamp). Even if the safety of the light rays can be ensured, the absorption wavelength of many general-purpose photopolymerization initiators is 350 nm or less, and absorption of 375 nm or more is almost never observed. This has resulted in new problems such as incomplete curing, long required curing times, and uneven curing, resulting in unsatisfactory physical properties of the cured product.

[0004] Radical photopolymerization initiators include intramolecular cleavage type and hydrogen abstraction type, which generate radical active species by irradiation with light. Intramolecular cleavage type photopolymerization initiators have high photopolymerization initiation efficiency, but low thermal stability, which causes problems with the storage stability of the initiator and the resin composition containing it. In addition, unreacted initiators and residues after reaction (intramolecular cleavage) remain in the cured product as low molecular weight compounds, which bleed out from the cured product over time, causing deterioration of the physical properties and durability of the cured product, odor generation, and contamination due to transfer and permeation of the substrate in contact, and safety has been particularly a concern.

[0005] Hydrogen abstraction type photopolymerization initiators have a diaryl ketone structure such as benzophenone, and they abstract hydrogen from hydrogen donors to generate radical active species, which can improve the problem of residues after reaction, and have been attracting attention in recent years. However, while hydrogen abstraction type photopolymerization initiators are generally highly stable against heat, they have low efficiency in initiating photopolymerization, and need to be used in combination with hydrogen donors such as amines and photosensitizers as additives, and since these additives are often low molecular weight compounds, they may remain in the cured product, which may cause problems such as deterioration in physical properties and durability of the cured product due to bleed-out, odor and contamination, and may also cause problems with coloring over time.

[0006] In order to improve the generation efficiency of radical active species, which is an issue with hydrogen abstraction type benzophenone photopolymerization initiators, Patent Document 1 synthesized a benzophenone derivative having many perester structures in the molecule as a highly sensitive photopolymerization initiator. However, although the introduction of the perester structure could increase the sensitivity, the perester structure itself is known to be easily decomposed by light or heat, and there was an issue that low molecular weight compounds were generated as residues after the polymerization reaction by light irradiation.

[0007] Patent Document 2 proposed a polymeric photopolymerization initiator having a benzophenone group as a photoactive moiety and an amine functional group or a tertiary amino group acting as a coinitiator. According to Patent Document 2, the inclusion of an amino group reduces inhibition by oxygen and improves the curing speed. However, both amines and amino groups are generally recognized as functional groups that have an amine odor, and it is known that these functional groups are very susceptible to coloration upon exposure to light. Furthermore, the photopolymerization initiator in Patent Document 2 has a high molecular weight, and therefore exhibits low mobility, which generally reduces the efficiency of radical generation and the reactivity of photopolymerization (curing speed).

[0008] On the other hand, in active energy ray curing systems, polymerizable compounds are used as essential components. Polymerizable compounds include monofunctional polymerizable compounds having one polymerizable functional group per molecule and multifunctional polymerizable compounds having two or more polymerizable functional groups per molecule, but in either case, most of the compounds are low molecular weight, and if they are not completely reacted and fixed in the cured product, they remain in the cured product as low molecular weight components, which causes odors and reduced durability of the cured product due to bleed-out, just like the decomposition products of photopolymerization initiators.

[0009] The present applicant has already disclosed a highly safe photopolymerization initiator having a benzophenone structure and an ethylenically unsaturated bond (Patent Document 3). Such a photopolymerization initiator does not produce low-molecular decomposition products by photoreaction, and can penetrate into the cured product through strong chemical bonds. It has been shown that the use of such a photopolymerization initiator can solve the odor problem of the cured product caused by the decomposition of the photopolymerization initiator and the bleed-out problem of the initiator decomposition products over time. However, when the photopolymerization initiator described in the document is used, the residue of the photopolymerization initiator after curing certainly penetrates into the cured product as a structural unit, but the total amount of low-molecular components present in the cured product is not described, and in addition, as described in the example of the document (

[0105] ), it cannot be said that the curability against long-wavelength LED light, especially 405 nm, is still sufficient.

[0010] Therefore, an active energy ray-curable composition that has high curability against long-wavelength LED light, which is highly safe, and has a low content of low molecular weight components in the cured product, and can provide a highly safe cured product, has not yet been found. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] JP 2000-159827 A [Patent Document 2] JP 2013-500303 A [Patent Document 3] WO2021 / 117880 publication Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention aims to provide an active energy ray-curable composition that has high curability to active energy rays including long-wavelength LED light rays, produces few unreacted substances and low-molecular-weight decomposition products, does not produce odors or bleed-out problems, has excellent compatibility, and can be completely cured even with long-wavelength light rays of 350 nm or more; and an active energy ray-curable pressure-sensitive adhesive, adhesive, sealant, ink, paint, coating agent, dental material, or cosmetic material containing the same; and a cured product obtained by curing the composition or the like. [Means for solving the problem]

[0013] The present inventors have conducted intensive research to solve the above problems, and have found an active energy ray curable composition comprising a polymerizable photoinitiator (A) having one or more benzophenone groups and one or more ethylenically unsaturated groups per molecule, and a polymerizable compound (B) (excluding A) having one ethylenically unsaturated group per molecule. The polymerizable photoinitiator (A) of the composition has high photoinitiation efficiency, no by-products of low molecular weight decomposition products, and is highly safe, and the polymerizable compound (B) has high curability. Furthermore, the compatibility between the polymerizable photoinitiator (A) and the polymerizable compound (B) is good, and a highly transparent curable composition and cured product applicable to the optical field can be obtained. In addition, the present inventors have found that the composition can be completely cured by light in a wide range of ultraviolet wavelengths, including long wavelengths close to the visible light region, and that the content of components having a molecular weight of less than 1000 in the cured product can be controlled to less than 10%, and that a cured product having low odor, high safety, and excellent water resistance, durability, strength, etc. can be obtained, which led to the present invention.

[0014] That is, the present invention provides (1) a polymerizable photoinitiator (A) having one or more benzophenone groups and one or more ethylenically unsaturated groups per molecule; an active energy ray-curable composition comprising a polymerizable compound (B) (excluding A) having one or more ethylenically unsaturated groups per molecule, wherein the content of components having a molecular weight of less than 1000 in a cured product of the active energy ray-curable composition is less than 10%; (2) The active energy ray-curable composition according to (1) above, wherein the polymerizable photoinitiator (A) and / or the polymerizable compound (B) have one or more covalent bonds between a heteroatom and a hydrogen atom per molecule. (3) The active energy ray-curable composition according to (1) or (2), wherein the polymerizable photoinitiator (A) and / or the polymerizable compound (B) have, as an ethylenically unsaturated group, one or more groups selected from a (meth)acrylamide group, a (meth)acrylate group, a vinyl group, a vinyl ether group, an alkyl vinyl ether group, an allyl group, a (meth)allyl ether group, a styryl group and a maleimide group; (4) The active energy ray-curable composition according to any one of (1) to (3), wherein the polymerizable photoinitiator (A) and / or the polymerizable compound (B) form a covalent bond with a hydrogen atom using one or more heteroatoms selected from oxygen, sulfur, nitrogen, phosphorus, boron, and silicon. (5) The active energy ray-curable composition according to any one of (1) to (4), wherein the polymerizable photoinitiator (A) has a (meth)acrylamide group as an ethylenically unsaturated group and has a urethane bond and / or a urea bond as a covalent bond between a hetero atom and a hydrogen atom. (6) An active energy ray-curable ink composition comprising the active energy ray-curable composition according to any one of (1) to (5). (7) An active energy ray-curable ink composition for inkjet recording, comprising the active energy ray-curable composition according to any one of (1) to (5). (8) An active energy ray-curable ink composition for two-dimensional or three-dimensional modeling, comprising the active energy ray-curable composition according to any one of (1) to (5). (9) An active energy ray-curable nail cosmetic composition comprising the active energy ray-curable composition according to any one of (1) to (5). (10) An active energy ray-curable pressure-sensitive adhesive composition comprising the active energy ray-curable composition according to any one of (1) to (5). (11) An active energy ray-curable adhesive composition comprising the active energy ray-curable composition according to any one of (1) to (5). (12) An active energy ray-curable sealing material composition containing the active energy ray-curable composition according to any one of (1) to (5). (13) An active energy ray-curable coating composition comprising the active energy ray-curable composition according to any one of (1) to (5). (14) An active energy ray-curable self-repairing coating material containing the active energy ray-curable composition according to any one of (1) to (5). (15) An active energy ray-curable dental composition comprising the active energy ray-curable composition according to any one of (1) to (5) above. This provides: Effect of the Invention

[0015] According to the present invention, the active energy ray curable composition containing the polymerizable photoinitiator (A) having one or more benzophenone groups and one or more ethylenically unsaturated groups per molecule, and the polymerizable compound (B) having one or more ethylenically unsaturated groups per molecule has excellent photopolymerization initiation and photocurability, can be completely cured with highly safe long-wavelength light, has a content of low molecular weight components having a molecular weight of less than 1000 in the cured product of less than 10%, does not produce odor or bleed-out, and can obtain a highly durable and safe cured product. The composition can be suitably used for various applications such as ink, inkjet ink and photocurable ink for three-dimensional modeling, ink for two-dimensional or three-dimensional modeling, nail cosmetics, pressure-sensitive adhesives, adhesives, sealants, coating agents, self-repairing paints, coating agents for vehicles, coating agents for building materials, and decorative films. In addition, the polymerizable photoinitiator (A) and the polymerizable compound (B) have good compatibility, and the active energy ray-curable composition of the present invention exhibits good transparency and can be suitably used for various applications in the optical field, such as optical pressure-sensitive adhesive sheets, optical adhesives, and optical sealants. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] This embodiment will be described in detail below. The active energy ray curable composition of this embodiment contains a polymerizable photoinitiator (A) having one or more benzophenone groups and one or more ethylenically unsaturated groups per molecule, and a polymerizable compound (B) (excluding A) having one or more ethylenically unsaturated groups per molecule, and the content of components with a molecular weight of less than 1000 in the cured product is less than 10%. The polymerizable photoinitiator (A) and the polymerizable compound (B) contained in the curable composition are both polymerizable compounds, and as photopolymerization progresses due to radicals generated by irradiation with active energy rays, both A and B are fixed as structural units in the cured product via covalent bonds, and both the polymerizable photoinitiator (A) and the polymerizable compound (B) are not decomposable by active energy rays, and there is no by-production of low molecular weight components such as decomposition products associated with photopolymerization, so the obtained cured product has a low content of low molecular weight components and excellent performance in various cured products. In the obtained cured product, the content of components having a molecular weight of less than 1000 is preferably less than 10%, and the content of components having a molecular weight of less than 1000 is preferably less than 5%, more preferably less than 2%, and even more preferably less than 500.

[0017] The polymerizable photoinitiator (A) contains one or more benzophenone groups and one or more ethylenically unsaturated groups per molecule. From the viewpoint of improving polymerization initiation and curing properties with respect to long wavelength light, and from the viewpoint of the polymerizable photoinitiator (A) being sure to penetrate into the cured product via a covalent bond by the polymerization reaction, the number of benzophenone groups per molecule is preferably 2 or more, and the number of ethylenically unsaturated groups is also preferably 2 or more. From the viewpoint that a curable composition containing a high content of the polymerizable photoinitiator (A) requires a sufficient pot life, it is preferable that the number of benzophenone groups per molecule does not exceed 50, and the number of ethylenically unsaturated groups does not exceed 12. From these viewpoints, it is more preferable that the number of benzophenone groups per molecule of the polymerizable photoinitiator (A) is 2 to 30, and the number of ethylenically unsaturated groups is 2 to 8, and it is particularly preferable that the number of benzophenone groups is 4 to 12, and the number of ethylenically unsaturated groups is 2 to 6. The ratio of the number of benzophenone groups to ethylenically unsaturated groups per molecule is preferably 1 / 10 to 10 / 1, more preferably 1 / 8 to 8 / 1, and particularly preferably 1 / 5 to 5 / 1. If this ratio is less than 0.1 (1 / 10), even if the photopolymerization (curing) reaction of the polymerizable photoinitiator (A) is completed, it is not fixed as a structural unit in the cured product through a covalent bond, and as a result, the remaining A (unreacted portion) is present in the cured product in a free state, and especially when the molecular weight of the polymerizable photoinitiator (A) is less than 1000, A is a low molecular weight component and is likely to cause odor problems, bleed-out and coloring problems over time, and durability deterioration problems of the cured product. On the other hand, when the ratio of these numbers exceeds 10.0 (10 / 1), although it depends on the content of the polymerizable photoinitiator (A) in the active energy ray-curable composition, the polymerization rate of the curable composition is significantly increased and the temperature rises rapidly due to the heat of polymerization, which makes it difficult to use the composition as a pressure-sensitive adhesive, adhesive, or sealant for optical components for plastic substrates, or as a nail cosmetic such as gel nails.

[0018] The ethylenically unsaturated group of the polymerizable photoinitiator (A) is one or more bonds selected from the group consisting of a (meth)acrylamide group, a (meth)acrylate group, a vinyl group, a vinyl ether group, a methyl vinyl ether group, an allyl group, a (meth)allyl ether group, a styryl group, and a maleimide group. When the polymerizable photoinitiator (A) has two or more ethylenically unsaturated groups, they may be the same or different. Furthermore, it is preferable that the ethylenically unsaturated group has at least one of a (meth)acrylamide group, a (meth)acrylate group, a vinyl group, and an allyl group, more preferably has at least one of a (meth)acrylamide group or a (meth)acrylate group, and particularly preferably has at least one (meth)acrylamide group. The (meth)acrylamide group or the carbonyl group of the (meth)acrylate group absorbs light with long wavelengths, which in turn shifts the absorption wavelength of the polymerizable photoinitiator (A) to the longer wavelength side. This makes it unnecessary to use high-energy, dangerous short-wavelength light, thereby increasing the safety of the photocuring reaction. Furthermore, because the (meth)acrylamide group has high polymerizability, the residue of the polymerizable photoinitiator (A) and its decomposition products are more reliably fixed in the cured product via covalent bonds.

[0019] The benzophenone group having the polymerizable photoinitiator (A) has a diaryl ketone structure, and is activated by irradiation with active energy rays to abstract hydrogen atoms from hydrogen-donating functional groups or compounds, and the functional groups or compounds from which hydrogen atoms have been abstracted become free radicals, which have high activity and become actual photopolymerization initiation radicals. Such hydrogen-donating functional groups or compounds are called coinitiators or polymerization synergists, and are characterized by having a hydrogen atom covalently bonded to a heteroatom or having a hydrogen atom covalently bonded to a carbon atom (α-position or β-position) adjacent to a heteroatom. The bond energy of the covalent bond between a heteroatom and a hydrogen atom is lower than that of the covalent bond between a carbon atom and a hydrogen atom, so having a covalent bond between a heteroatom and a hydrogen atom in the active energy ray curable composition is preferable because it can more easily generate highly active free radicals.

[0020] In this embodiment, the co-initiator may be the polymerizable photoinitiator (A) itself, may be a polymerizable compound (B), or may further include a compound other than A and B. When the polymerizable photoinitiator (A) has a covalent bond between a heteroatom and a hydrogen atom in the molecule, A can play two roles as an initiator and a co-initiator. The polymerizable photoinitiator (A) preferably has one or more covalent bonds between a heteroatom and a hydrogen atom per molecule, and more preferably has two or more. The polymerizable photoinitiator (A) can abstract hydrogen both intramolecularly and intermolecularly, and preferably has three or more linking atoms between the oxygen atom of the ketone bond of the benzophenone group and the heteroatom, more preferably has five or more linking atoms, and most preferably has seven or more linking atoms, so that the intramolecular hydrogen abstraction can proceed easily. When the benzophenone group has three or more linking atoms between the oxygen atom of the ketone bond and the heteroatom, the oxygen atom can easily approach the hydrogen atom bonded to the heteroatom, and the benzophenone group can easily abstract hydrogen atoms from the heteroatom. Considering the accessible distance between the oxygen atom of the ketone bond of the benzophenone group and the hydrogen atom, it is preferable that the number of linking atoms between the oxygen atom and the heteroatom is 15 or less, and more preferably 12 or less. The heteroatom is preferably an oxygen atom, a sulfur atom, a nitrogen atom, a phosphorus atom, a boron atom, or a silicon atom.

[0021] When the polymerizable photoinitiator (A) has a covalent bond between a heteroatom and a hydrogen atom, examples of the functional group having the covalent bond include OH, NH, SH, SiH, COOH, CONH, CONH2, NHCOO, NHCONH, SO3H, and PO4H2. In addition, the functional group NHCOO (urethane bond) and the functional group NHCONH (urea bond) are preferred because hydrogen is more easily extracted from the NH group under the influence of the carbonyl group (CO), and the initiation efficiency of the polymerizable photoinitiator (A) is higher. The functional groups possessed by the polymerizable photoinitiator (A) can be any one or more types, or one or more, selected from the above group. The number of one type of heteroatom-containing functional group per molecule of the polymerizable photoinitiator (A) is preferably 1 to 40. If the polymerizable photoinitiator has one or more heteroatom-containing functional groups, it can play the role of a coinitiator derived from a heteroatom, which is preferred. On the other hand, if the number of heteroatom-containing functional groups exceeds 40, the hydrophilicity of the heteroatom-containing functional groups is high and the functional groups are likely to form hydrogen bonds with each other, which leads to problems such as a decrease in hydrophilicity of the polymerizable photoinitiator (A), a decrease in solubility in organic solvents, and a decrease in water resistance and moisture resistance of a cured product of a curable composition containing the polymerizable photoinitiator (A). From these viewpoints, the number of one type of heteroatom-containing functional groups per molecule of the polymerizable photoinitiator (A) is more preferably 2 to 20, and particularly preferably 4 to 10.

[0022] The polymerizable photoinitiator (A) preferably further contains a structural unit derived from a polyol or polyamine in the molecule. The benzophenone group of the polymerizable photoinitiator (A) has an aromatic planar structure and is highly hydrophobic, so that it has low compatibility with polar (meth)acrylic monomers and oligomers, and depending on the composition of the active energy ray curable composition, a highly transparent curable composition and its cured product may not be obtained. Therefore, by introducing a urethane bond or a urea bond as a polar functional group into the molecule of the polymerizable photoinitiator (A), the polymerizable photoinitiator (A) has both rigidity derived from aromatics and toughness derived from a urethane structure or a urea structure, and has a good balance between hydrophilicity and hydrophobicity, and has good compatibility with general-purpose (meth)acrylic monomers and oligomers from hydrophilic to hydrophobic properties, and by using such a polymerizable photoinitiator (A), a highly transparent active energy ray curable composition can be obtained.

[0023] In the polymerizable photoinitiator (A), the method of introducing the structural unit derived from polyol or polyamine is not particularly limited. The structural unit derived from polyol or polyamine can be introduced by using polyol or polyamine as a raw material, and the polyol is not particularly limited as long as it is a compound having two or more hydroxyl groups in the molecule, and the polyamine is not particularly limited as long as it is a compound having two or more primary or secondary amino groups in the molecule. For example, the polyol may be an alkylene diol, an alkylene polyol, a polyether polyol, a polyester polyol, a polycarbonate polyol, a polyolefin polyol, a silicone polyol, an acrylic polyol, etc. Examples of polyamines include alkylene diamines such as ethylenediamine, putrescine, cadaverine, triethylenediamine, and hexamethylenediamine, ethambutol, phenylenediamine, isophoronediamine, norbornenediamine, dicyclohexylmethanediamine, diethylenetriamine, bis(hexamethylene)triamine, spermine, spermidine, polyetherpolyamine, polyamidepolyamine, polyamine epichlorohydrin, and polyethyleneimine. These polyols and polyamines may be used alone or in combination of two or more. Polyols are more preferred because the resulting cured product is less likely to be colored.

[0024] The polymerizable photoinitiator (A) can be produced by using various known or commonly used synthesis methods. For example, there are a method of reacting benzophenone having a hydroxyl group with a polymerizable compound having an isocyanate, carboxylic acid, or acid anhydride as a functional group; a method of synthesizing benzophenone having a hydroxyl group, a polyisocyanate having two or more isocyanate groups in the molecule, and a polymerizable compound having a hydroxyl group by a urethane reaction in a sequential or batch manner; a method of synthesizing benzophenone having a hydroxyl group, a polyisocyanate, a polyol, and / or a polyamine, and a polymerizable compound having a hydroxyl group by a urethane and / or urea reaction in a sequential or batch manner; a method of directly reacting a polymerizable compound having a hydroxyl group, an amino group, a glycidyl group, or the like using benzophenone having one or more carboxyl groups or acid anhydride functional groups as functional groups in the molecule, such as benzophenone dicarboxylic acid, benzophenone tetracarboxylic acid, or benzophenone tetracarboxylic dianhydride, with a polymerizable compound having a hydroxyl group, an amino group, a glycidyl group, or the like; and a method of reacting sequentially or batchwise using a polyisocyanate, polyol, or polyamine similar to the above. Methods such as those described in Patent Document 3 are used. In the production process, in order to suppress the generation of radicals due to light irradiation, it is preferable to carry out the work in a light-shielded environment. Specifically, it is preferable to carry out the reaction in a light-shielded environment, or under a fluorescent lamp or a red safelight for a darkroom that does not irradiate ultraviolet light.

[0025] In this embodiment, the molecular weight (number average) of the polymerizable photoinitiator (A) is preferably 1000 or more. When the molecular weight of the polymerizable photoinitiator (A) is 1000 or more, even if the polymerizable photoinitiator (A) remains in the cured product in an unreacted state after photopolymerization reaction (curing) or exists in the cured product in the form of a radical formed by abstracting hydrogen, it is not a low molecular weight component with a molecular weight of less than 1000, so it does not cause odor problems, problems of bleed-out or coloring over time, problems of reduced durability, etc. of the cured product. As the molecular weight of the polymerizable photoinitiator (A) increases, the liquid viscosity of the active energy ray curable composition tends to increase, and from the viewpoint of expressing good operability, the number average molecular weight of the polymerizable photoinitiator (A) is preferably 100,000 or less. In addition, the number average molecular weight of the polymerizable photoinitiator (A) is more preferably 1,500 to 80,000, and particularly preferably 2,000 to 50,000.

[0026] In the active energy ray curable composition of the present embodiment, the content of the polymerizable photoinitiator (A) is preferably 0.1 to 95 mass% based on the entire curable composition. When the polymerizable photoinitiator (A) is contained within this range, the function of generating radicals by irradiation with active energy rays such as ultraviolet rays and the function of generating highly active free radicals by the subsequent hydrogen abstraction reaction are exhibited. In addition, from the viewpoint of improving the curability of the active energy ray curable composition by interaction with the polymerizable compound (B) and reducing the amount of components having a molecular weight of less than 1000 in the obtained cured product, the content of the polymerizable photoinitiator (A) is preferably 0.5 to 90 mass%, more preferably 1.0 to 80 mass%, based on the entire curable composition.

[0027] The active energy ray curable composition of the present embodiment contains a polymerizable compound (B) (excluding A) having one or more ethylenically unsaturated groups per molecule. The polymerizable compound (B) can be classified into a monofunctional unsaturated compound (b1) having one ethylenically unsaturated group and one or more covalent bonds between heteroatoms and hydrogen atoms per molecule, a polyfunctional unsaturated compound (b2) having two or more ethylenically unsaturated groups and one or more covalent bonds between heteroatoms and hydrogen atoms per molecule, and a monofunctional or polyfunctional unsaturated compound (b3) having one or more ethylenically unsaturated groups per molecule but no covalent bonds between heteroatoms and hydrogen atoms. The ethylenically unsaturated group in the polymerizable compound (B) is one or more groups selected from a (meth)acrylamide group, a (meth)acrylate group, a vinyl group, a vinyl ether group, an alkyl vinyl ether group, an allyl group, a (meth)allyl ether group, a styryl group, and a maleimide group. In addition, these unsaturated compounds (b1), (b2) and (b3) may be used alone or in combination of two or more kinds. Furthermore, b1, b2 and b3 may each be independently a single compound or a plurality of compounds selected from the same or different kinds and used in any combination.

[0028] The polymerizable compound (B) is preferably an unsaturated compound (b1) and / or (b2) having one or more covalent bonds between heteroatoms and hydrogen atoms per molecule. When the polymerizable compound (B) has a covalent bond between a heteroatom and a hydrogen atom in its molecule, B can play two roles as a curable component and a coinitiator in the active energy ray curable composition. The polymerizable photoinitiator (A) abstracts a hydrogen atom from the covalent bond between the heteroatom and the hydrogen atom of the polymerizable compound (B), and the polymerizable compound (B) becomes a highly active free radical, which can initiate radical polymerization of the ethylenically unsaturated groups of the polymerizable photoinitiator (A) and the polymerizable compound (B). In addition, the radical of the polymerizable compound (B) formed by abstracting hydrogen atoms is more active than the radical of the polymerizable photoinitiator (A) formed by abstracting hydrogen atoms, so the photopolymerization reaction, i.e., the curing reaction of the active energy ray curable composition, can proceed at a higher speed by forming the radical of the polymerizable compound (B), and is safer. The curing reaction can be completed even with low-energy long-wavelength light, and the content of low molecular weight components in the obtained cured product can be controlled to less than 10%. From these viewpoints, it is more preferable that the polymerizable compound (B) ((b1) and / or (b2)) has two or more covalent bonds between heteroatoms and hydrogen atoms per molecule. The heteroatom is preferably one or more of oxygen atoms, sulfur atoms, nitrogen atoms, phosphorus atoms, boron atoms, and silicon atoms.

[0029] When the polymerizable compound (B) has a covalent bond between a heteroatom and a hydrogen atom, the functional group having the covalent bond may be OH, NH, SH, SiH, COOH, CONH, CONH2, NHCOO, NHCONH, SO3H, PO4H2, etc. In addition, the functional group NHCOO (urethane bond) and the functional group NHCONH (urea bond) are preferred because hydrogen is more easily extracted from the NH group under the influence of the carbonyl group (CO), and the initiation efficiency of the polymerizable photoinitiator (A) is higher. In addition, the functional group having the polymerizable photoinitiator (A) may be any one or more types, or one or more, selected from the above group.

[0030] When the monofunctional unsaturated compound (b1) having a covalent bond between a hetero atom and a hydrogen atom has a (meth)acrylate group as an ethylenically unsaturated group, specific examples thereof include hydroxyalkyl (meth)acrylates having a linear, branched or cyclic hydroxyalkyl group having 1 to 18 carbon atoms introduced therein, (meth)acrylic acid and hydroxyalkyl carboxylic acids such as ethyl (meth)acrylate carboxylic acid, ethyl (meth)acrylate succinic acid, ethyl (meth)acrylate phthalic acid, and ethyl (meth)acrylate hexahydrophthalic acid, and the like. Examples of such monomers include (meth)acrylic acid alkylsulfonic acids having a linear, branched or cyclic alkylsulfonic acid group having 1 to 18 carbon atoms, (meth)acrylic acid alkyl phosphates having a linear, branched or cyclic alkyl phosphate group having 1 to 18 carbon atoms, aminoalkyl (meth)acrylates having an aminoalkyl group having 1 to 18 carbon atoms, N-alkylaminoalkyl (meth)acrylates having an N-alkylaminoalkyl group consisting of an aminoalkyl group having 1 to 18 carbon atoms and an alkyl group having 1 to 18 carbon atoms, and glycerin mono(meth)acrylate. Among these, hydroxyalkyl (meth)acrylates, (meth)acrylic acid alkyl carboxylic acids and aminoalkyl (meth)acrylates are preferred as monomers having a covalent bond between a heteroatom and a hydrogen atom.

[0031] When the monofunctional unsaturated compound (b1) having a covalent bond between a hetero atom and a hydrogen atom has a (meth)acrylamide group as an ethylenically unsaturated group, specific examples thereof include (meth)acrylamide, N-alkyl(meth)acrylamide having a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms introduced therein, N-hydroxyalkyl(meth)acrylamide having a hydroxyalkyl group having 1 to 18 carbon atoms introduced therein, N,N-di(hydroxyalkyl)(meth)acrylamide, N-hydroxyalkyl-N-(4-hydroxyphenyl)(meth)acrylamide, N-alkyl-N-hydroxyalkyl(meth)acrylamide having a hydroxyalkyl group having 1 to 18 carbon atoms and an alkyl group having 1 to 18 carbon atoms introduced therein, N-alkyl-N-(4-hydroxyphenyl)(meth)acrylamide, 4-hydroxyphenyl(meth)acrylamide, N,N-di(4-hydroxyphenyl)(meth)acrylamide, Examples of such acrylamides include (meth)acrylamidoalkylcarboxylic acids having an alkyl carboxyl group having 1 to 18 carbon atoms introduced therein, N-alkoxyalkyl(meth)acrylamides having an alkoxyalkyl group consisting of an alkoxy group having 1 to 18 carbon atoms and an alkylene group having 1 to 16 carbon atoms introduced therein, N-sulfoalkylacrylamides having an alkylsulfonic acid group having 1 to 18 carbon atoms introduced therein, N-alkylamino(meth)acrylamides having an aminoalkyl group having 1 to 18 carbon atoms introduced therein, N-alkylaminoalkyl(meth)acrylamides having an N-alkylaminoalkyl group consisting of an aminoalkyl group having 1 to 18 carbon atoms and an alkyl group having 1 to 18 carbon atoms introduced therein, N,N-dialkylaminoalkyl(meth)acrylamides having an aminoalkyl group having 1 to 18 carbon atoms and an N,N-dialkylaminoalkyl group consisting of an alkyl group having 1 to 18 carbon atoms and an alkyl group having 1 to 18 carbon atoms introduced therein, and diacetone acrylamide. Of these, N-isopropylacrylamide, N,N-dimethylaminopropylacrylamide, N-hydroxyethylacrylamide, and diacetone acrylamide are preferred because they are easily available industrially, and among these, hydroxyalkyl(meth)acrylamide, (meth)acrylamide alkyl carboxylic acid, aminoalkyl(meth)acrylamide, diacetone acrylamide, and the like are preferred as monomers having a covalent bond between a heteroatom and a hydrogen atom.In particular, N-hydroxyethyl(meth)acrylamide, N-hydroxypropyl(meth)acrylamide, and N-hydroxybutyl(meth)acrylamide are more preferable since they are liquid at room temperature and have no skin irritation (PII=0).

[0032] When the monofunctional unsaturated compound (b1) having a covalent bond between a hetero atom and a hydrogen atom has a vinyl group as an ethylenically unsaturated group, specific examples thereof include vinyl carboxylates having a carboxylic acid having 1 to 22 carbon atoms, maleic acid, fumaric acid, itaconic acid, maleic acid monoalkyl esters having a linear, branched or cyclic alkyl group having 1 to 22 carbon atoms, maleic acid monoalkylamides, fumaric acid monoalkyl esters, fumaric acid monoalkyl amides, itaconic acid monoalkyl esters, itaconic acid monoalkyl amides, vinyl sulfonic acid, vinyl phosphoric acid, etc. Among these, maleic acid, fumaric acid, itaconic acid, etc. are preferred because they are easily available industrially.

[0033] When the monofunctional unsaturated compound (b1) having a covalent bond between a heteroatom and a hydrogen atom has an allyl group as an ethylenically unsaturated group, specific examples thereof include carboxylic acid allyl esters, allylamines, and monoalkylallylamines having a branched or cyclic alkyl group with 1 to 22 carbon atoms. When the monofunctional unsaturated compound (b1) having a covalent bond between a heteroatom and a hydrogen atom has a styryl group as an ethylenically unsaturated group, specific examples thereof include p-styrenesulfonic acid having a sulfonic acid group. When the monofunctional unsaturated compound (b1) having a covalent bond between a heteroatom and a hydrogen atom has a maleimide group as an ethylenically unsaturated group, specific examples thereof include N-hydroxyalkylmaleimide, N-(2-carboxyalkyl)maleimide, glycerin mono(N-hydroxyalkylmaleimide) ester, and trimethylolpropane mono(N-hydroxyalkylmaleimide) ester having a linear, branched, or cyclic alkyl group with 1 to 18 carbon atoms. The various monofunctional unsaturated compounds (b1) may be used either individually or in combination of two or more.

[0034] Specific examples of the polyfunctional unsaturated compound (b2) having a covalent bond between a hetero atom and a hydrogen atom include di(meth)acrylamide, diallylamine, divinylamine, allyl(meth)acrylamide, alkyldiallylamine having an alkyl group having 1 to 18 carbon atoms, bisphenol A diglycidyl ether acrylic acid adducts, and polyurethane di(meth)acrylamides, as well as trifunctional or higher polyfunctional unsaturated compounds such as pentaerythritol tri(meth)acrylate, dipentylamine, and the like. Examples of the polyfunctional unsaturated compound (b2) include taerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, glycerin di(meth)acrylate, glycerin polyglycidyl ether poly(meth)acrylate, isocyanuric acid ethylene oxide modified tri(meth)acrylate, ethylene oxide modified dipentaerythritol penta(meth)acrylate, ethylene oxide modified pentaerythritol tri(meth)acrylate, succinic acid modified pentaerythritol tri(meth)acrylate, etc. These polyfunctional unsaturated compounds (b2) may be used alone or in combination of two or more kinds.

[0035] When the monofunctional or polyfunctional unsaturated compound (b3) having no covalent bond between a hetero atom and a hydrogen atom has one (meth)acrylate group as an ethylenically unsaturated group in the molecule, specifically, alkyl (meth)acrylates having a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms introduced therein, alkoxyalkylene glycol (meth)acrylates, alkoxydialkylene glycol (meth)acrylates, alkoxytrialkylene glycol (meth)acrylates, alkoxypolyalkylene glycol (meth)acrylates having a functional group consisting of an alkyl group having 1 to 18 carbon atoms and an alkylene glycol group having 1 to 6 carbon atoms introduced therein, phenoxyalkylene glycol (meth)acrylates, phenoxydialkylene glycol (meth)acrylates, phenoxytrialkylene glycol (meth)acrylates, phenoxypolyalkylene glycol (meth)acrylates having a functional group consisting of a phenoxy group and an alkylene glycol group having 1 to 6 carbon atoms introduced therein, Examples of the acrylate include polyalkylene glycol (meth)acrylate, N,N-dialkylaminoalkyl group having an aminoalkyl group with 1 to 18 carbon atoms and an N,N-dialkylaminoalkyl group having an alkyl group with 1 to 18 carbon atoms, (meth)acrylates having a cyclic structure such as benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and 2-methyl-2-adamantyl (meth)acrylate, and (meth)acrylates having an epoxy group such as glycidyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate glycidyl ether.

[0036] When the monofunctional or polyfunctional unsaturated compound (b3) having no covalent bond between a hetero atom and a hydrogen atom has one (meth)acrylamide group as an ethylenically unsaturated group in the molecule, specific examples thereof include N,N-dialkyl(meth)acrylamide having a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms introduced therein, (meth)acryloylmorpholine, N,N-di(alkoxyalkyl)(meth)acrylamide having an alkoxyalkyl group consisting of an alkoxy group having 1 to 18 carbon atoms and an alkylene group having 1 to 16 carbon atoms introduced therein, an alkoxyalkyl group consisting of an alkoxy group having 1 to 18 carbon atoms and an alkylene group having 1 to 18 carbon atoms, N-alkyl-N-alkoxyalkyl(meth)acrylamide having an alkyl group having 1 to 18 carbon atoms introduced therein, dialkylaminoalkyl group consisting of an alkyl group having 1 to 18 carbon atoms and an alkylene group having 1 to 18 carbon atoms, and N-alkyl-N-[(dialkylamino)alkyl](meth)acrylamide having an alkyl group having 1 to 18 carbon atoms introduced therein. Among these, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-methyl-N-[(dimethylamino)propyl]acrylamide, N-acryloylmorpholine, etc. are preferred because they are easily available industrially. In particular, N-acryloylmorpholine, which is a liquid at room temperature and has low skin irritation (PII=0.5), is more preferred.

[0037] When the monofunctional or polyfunctional unsaturated compound (b3) having no covalent bond between a heteroatom and a hydrogen atom has one vinyl group as an ethylenically unsaturated group in the molecule, specific examples thereof include alkyl vinyl ethers having a linear, branched or cyclic alkyl group having 1 to 22 carbon atoms, vinyl chloride, N-vinylpyrrolidone, N-vinylcaprolactam, N-vinyloxazoline, maleic anhydride, itaconic anhydride, maleic acid dialkyl esters, maleic acid dialkylamides, maleic acid alkylimides, fumaric acid dialkyl esters, fumaric acid dialkylamides, itaconic acid dialkyl esters, itaconic acid dialkylamides, itaconic acid alkylimides, vinyl carboxylic acids, etc. Among these, N-vinylpyrrolidone, N-vinylcaprolactam, maleic anhydride, etc. are preferred because of their industrial availability.

[0038] When the monofunctional or polyfunctional unsaturated compound (b3) does not have a covalent bond between a heteroatom and a hydrogen atom, and has one allyl group as an ethylenically unsaturated group in the molecule, specific examples thereof include alkyl allyl ethers, phenyl allyl ethers, alkyl phenyl allyl ethers, and dialkyl allyl amines having a branched or cyclic alkyl group with 1 to 22 carbon atoms. When the monofunctional or polyfunctional unsaturated compound (b3) does not have a covalent bond between a heteroatom and a hydrogen atom, and has one styryl group as an ethylenically unsaturated group in the molecule, specific examples thereof include styrene, α-alkylstyrenes having an alkyl group with 1 to 18 carbon atoms at the α-position, α-methylstyrene dimers, o-alkylstyrenes having an alkyl group with 1 to 18 carbon atoms at the phenyl group, m-alkylstyrenes, and p-alkylstyrenes. Among these, styrene, α-methylstyrene, and α-methylstyrene dimers are preferred because they are easily available industrially.

[0039] When the monofunctional or polyfunctional unsaturated compound (b3) having no covalent bond between a hetero atom and a hydrogen atom has two or more ethylenically unsaturated groups in the molecule, specific examples thereof include di(meth)acrylates, divinyl compounds such as divinylbenzene, bismaleimide compounds, allyl(meth)acrylates, methyl(2-allyloxymethyl)acrylate, 2-(2-vinyloxyethoxy)ethyl acrylate, onium salts formed by combining at least one anion selected from known inorganic acid anions or organic acid anions with a dialkyldiallylammonium cation having an alkyl group having 1 to 18 carbon atoms, alkylene glycol di(meth)acrylates, polyalkylene glycol di(meth)acrylates, and alkoxylated bisphenols. A diacrylates, polyester di(meth)acrylates, polycarbonate di(meth)acrylates, polyurethane di(meth)acrylates, pentaerythritol tetra(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tri(meth)acryloyloxyethoxytrimethylolpropane, ethylene oxide modified dipentaerythritol hexa(meth)acrylate, ethylene oxide modified pentaerythritol tetra(meth)acrylate, polyethoxy modified trimethylolpropane tri(meth)acrylate, etc. Also, the various monofunctional or polyfunctional unsaturated compounds (b3) may be used alone or in combination of two or more.

[0040] In the active energy ray curable composition of the present embodiment, the content of the polymerizable compound (B) is 5 to 99.9 mass% based on the total amount of the curable composition. When the polymerizable compound (B) is contained within this range, the curability to active energy rays such as ultraviolet rays is high, the curing reaction can be completed in a short time, the amount of unreacted residue is extremely small, and the content of low molecular weight components in the obtained cured product is kept low. The content of the polymerizable compound (B) is more preferably 10 to 99.5 mass%, and particularly preferably 20 to 99 mass%.

[0041] The content of the monofunctional unsaturated compound (b1) having a covalent bond between a heteroatom and a hydrogen atom as the polymerizable compound (B) is preferably 0 to 98 mass%, more preferably 5 to 90 mass%, and particularly preferably 10 to 80 mass%, based on the entire active energy ray curable composition. The content of the polyfunctional unsaturated compound (b2) having a covalent bond between a heteroatom and a hydrogen atom is preferably 0 to 90 mass%, more preferably 1 to 80 mass%, and particularly preferably 5 to 70 mass%, based on the entire active energy ray curable composition. Furthermore, the content of the monofunctional or polyfunctional unsaturated compound (b3) not having a covalent bond between a heteroatom and a hydrogen atom is preferably 0 to 90 mass%, more preferably 2 to 75 mass%, and particularly preferably 5 to 65 mass%, based on the entire active energy ray curable composition. Since b1 and b2 are compounds having a covalent bond between a heteroatom and a hydrogen atom, and function as hydrogen donors while being polymerizable compounds, if the total content of them is 3% by mass or more, the active energy ray curable composition can be completely cured by highly safe long-wavelength light, the cured product has few low molecular weight components, does not have odor, does not bleed out over time, and does not color over time, and a highly durable and safe cured product can be obtained, which is preferable. From the same viewpoint, the total content of b1 and b2 is more preferably 6% by mass or more. If the content of b1 and b2 is within these ranges, it can be suitably used for various applications such as ink, inkjet ink and photocurable three-dimensional modeling ink, two-dimensional or three-dimensional modeling ink, dental materials, nail cosmetics, adhesives, adhesives, sealants, coating agents, self-repairing paints, vehicle coating agents, building material coating agents, and decorative films. Furthermore, when the contents of b1 to b3 are within these ranges, the compatibility between the polymerizable photoinitiator (A) and b1 to b3 is good, and an active energy ray-curable composition having good transparency can be easily prepared, and the composition can be suitably used for various applications in the optical field, such as an optical pressure-sensitive adhesive sheet, an optical adhesive, or an optical sealant.

[0042] As the polymerizable compound (B), the monofunctional unsaturated compound (b1) having a covalent bond between a heteroatom and a hydrogen atom may be used alone or in combination of two or more kinds. As the polymerizable compound (B), the polyfunctional unsaturated compound (b2) having a covalent bond between a heteroatom and a hydrogen atom may be used alone or in combination of two or more kinds. Also, as the polymerizable compound (B), the monofunctional or polyfunctional unsaturated compound (b3) not having a covalent bond between a heteroatom and a hydrogen atom may be used alone or in combination of two or more kinds. b1 to b3 can be used in appropriate combination depending on the purpose. Among them, it is preferable to have a (meth)acrylamide group as the ethylenically unsaturated group. The amide bond of the (meth)acrylamide group has good wettability and adhesion to various substrates, and the active energy ray curable composition is suitably used for adhesives, paints, inks, etc. Also, the presence of the amide bond of the (meth)acrylamide group makes it easy to form intramolecular and intermolecular hydrogen bonds, and the active energy ray curable composition has high cohesive force, making it suitable for use as an adhesive or sealant. Furthermore, the amide bond of the (meth)acrylamide group has higher acid resistance, alkyl resistance, and hydrolysis resistance than the ester bond of the (meth)acrylate group, and when used as an ink for 3D stereolithography, a dental material, a coating agent for a vehicle, or a coating agent for a building material, the cured product has excellent durability. The use of hydroxyalkyl (meth)acrylamide as the monofunctional unsaturated compound (b1) having a covalent bond between a heteroatom and a hydrogen atom and / or the introduction of the ethylenic unsaturated group of the polyfunctional unsaturated compound (b2) having a covalent bond between a heteroatom and a hydrogen atom using hydroxyalkyl (meth)acrylamide ensures high safety even if unreacted b1 or b2 remains, and is therefore suitable for use as a nail cosmetic.Furthermore, the use of methacrylamide groups tends to result in higher heat resistance, water resistance, and moist heat resistance than the use of acrylamide groups, while the use of acrylamide groups tends to result in higher curability and a faster curing rate than the use of methacrylamide groups. Therefore, it is preferable to appropriately select and use a (meth)acrylamide-based monofunctional unsaturated compound (b1) having a covalent bond between a hetero atom and a hydrogen atom, a polyfunctional unsaturated compound (b2) having a covalent bond between a hetero atom and a hydrogen atom, or a monofunctional or polyfunctional unsaturated compound (b3) not having a covalent bond between a hetero atom and a hydrogen atom depending on the various applications.

[0043] The active energy ray curable composition in this embodiment can be used without containing an organic solvent. In addition, in order to improve workability such as coating property, an organic solvent can be added as necessary to adjust the liquid viscosity. The added organic solvent may be removed beforehand during active energy ray curing, or the composition may be cured while still containing the organic solvent. Furthermore, the organic solvent may be removed after curing, and can be appropriately selected according to the method of use and purpose of the curable composition and the cured product obtained. The amount of organic solvent added is not particularly limited, but is preferably 80% by mass or less, more preferably 50% by mass or less, based on the entire photocurable composition, from the viewpoint of reducing the energy and time required for removing the organic solvent.

[0044] Examples of the organic solvent used in the active energy ray-curable composition of the present embodiment include alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate, propyl acetate, butyl acetate, methyl lactate, and ethyl lactate; alkylene glycols such as ethylene glycol and propylene glycol; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; glycol ethers such as ethoxydiethylene glycol and methoxypropylene glycol; glycol esters such as propylene glycol acetate; tetrahydrofuran, methyltetrahydrofuran, cyclopentyl glycol, and the like. Examples of the organic solvent include ethers such as methyl ether, methyl tetrahydropyran, methyl tert-butyl ether, and toluene, aromatic hydrocarbons such as xylene, aliphatic hydrocarbons such as hexane and cyclohexane, amides such as N,N'-dimethylformamide and dimethylacetamide, amide ethers such as β-methoxy-N,N-dimethylpropionamide and β-butoxy-N,N-dimethylpropionamide, pyrrolidones such as 2-pyrrolidone and N-methylpyrrolidone, piperidines such as N-methylpiperidine, halogenated hydrocarbons such as methylene chloride, chloroform, and dichloroethane, sulfoxides such as dimethyl sulfoxide, and imidazolidinones such as 1,3-dimethyl-2-imidazolidinone. These organic solvents may be used alone or in combination of two or more.

[0045] The light beam used for curing the active energy ray curable composition of the present embodiment is not particularly limited as long as it is a light beam that can cause the polymerizable photoinitiator (A) to abstract hydrogen atoms from the components of the curable composition and generate active radicals by irradiation.Specific examples of the light energy beam include visible light, electron beam, ultraviolet light (vacuum ultraviolet light, far ultraviolet light, near ultraviolet light), infrared light (near infrared light, mid infrared light, far infrared light), laser light, infrared light, X-rays, α rays, β rays, γ rays, etc., and it is preferable to use ultraviolet light from the viewpoint of a good balance between generator, curing speed, and safety. The source (light source) of the active energy ray may be, for example, one or more selected from the group consisting of ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, mercury xenon lamps, metal halide lamps, high power metal halide lamps, xenon lamps, pulsed xenon lamps, deuterium lamps, fluorescent lamps, Nd-YAG triple harmonic lasers, He-Cd lasers, nitrogen lasers, Xe-Cl excimer lasers, Xe-F excimer lasers, semiconductor pumped solid-state lasers, LED lamps, etc. From the viewpoints of high safety, energy saving, and environmental friendliness, it is preferable to use light-emitting diode (LED) lamps that generate ultraviolet rays with a wavelength of 350 to 420 nm, have a high energy-to-light conversion efficiency, are easy to increase the output, and do not use harmful mercury.

[0046] The active energy ray-curable composition of the present embodiment includes an active energy ray-curable pressure-sensitive adhesive composition used for an active energy ray-curable pressure-sensitive adhesive, an active energy ray-curable adhesive composition used for an active energy ray-curable adhesive, an active energy ray-curable sealant composition used for a sealing material, a sealant, or the like, an active energy ray-curable flexographic printing ink composition or an active energy ray-curable offset printing ink composition, an active energy ray-curable screen printing ink composition, an active energy ray-curable inkjet printing ink composition, an active energy ray-curable nail cosmetic composition used for gel nails, or the like, an active energy ray-curable dental composition used for dental arch models, orthodontics, implant treatment, or the like, an active energy ray-curable composition for automobiles, electrical appliances, furniture, or the like. It can be suitably used for active energy ray curable coating compositions used in paints and coating agents, active energy ray curable decorative sheet compositions used in decorative sheets used for surface coatings of automobiles and electrical appliances, coating agents having self-repairing properties, functional members such as three-dimensional objects, nail decoration materials, automobile exterior protection, decorative films, devices, etc., active energy ray curable self-repairing material compositions used in transparent adhesive sheets, buffer materials, packings, vibration-proof materials, sound-absorbing materials, printing plates, sealing materials, abrasives, etc., active energy ray curable three-dimensional modeling compositions such as model materials and support materials for 3D printers, photocurable vehicle coating compositions such as automobile paints, etc. In addition, the applications in which the active energy ray curable composition can be used are not limited to these. When the active energy ray curable composition is used for these applications, it can also be used by mixing polymers and various additives as other components as necessary and adjusting according to the application.

[0047] Examples of the polymer to be added to the active energy ray curable composition include polyurethane resin, polyester resin, polyamide resin, polyimide resin, polyether resin, polyvinyl acetate, epoxy resin, polyacrylamide, rosin, starch, carboxymethyl cellulose, etc. Among them, natural resins such as rosin, starch, carboxymethyl cellulose, rosin-modified phenolic resin, rosin-modified maleic acid resin, rosin-modified alkyd resin, rosin-modified petroleum resin, rosin ester resin, and vegetable oil-modified alkyd resin, or processed resins derived from natural raw materials, have a high degree of biomass and are preferred. These polymers may be used alone or in combination of two or more. The amount of the polymer to be added is not particularly limited as long as it does not adversely affect the properties of the active energy ray curable composition and the molded products for various applications using the same, but is preferably 10% by mass or less, more preferably 5% by mass or less, based on the entire active energy ray curable composition.

[0048] Examples of additives to be added to the active energy ray curable composition include thermal polymerization inhibitors, antioxidants, ultraviolet sensitizers, preservatives, phosphate esters and other flame retardants, surfactants, antistatic agents, pigments such as yellow pigments, magenta pigments, cyan pigments, black pigments, and white pigments, dyes, fragrances, defoamers, fillers, silane coupling agents, surface tension regulators (surface regulators), plasticizers, surface lubricants, leveling agents, softeners, organic fillers, inorganic fillers, and silica particles. These additives may be used alone or in combination of two or more. The content of these additives is not particularly limited as long as it does not adversely affect the properties exhibited by the active energy ray curable composition and molded products for various applications using the same, but is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less, based on the entire active energy ray curable composition.

[0049] The sensitizer to be added to the active energy ray curable composition is not particularly limited, but is preferably an anthracene-based sensitizer, a thioxanthone-based sensitizer, or the like. Specific examples include anthracene-based sensitizers such as 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, and 9,10-bis(2-ethylhexyloxy)anthracene, and thioxanthone-based sensitizers such as 2,4-diethylthioxanthone, 2-isopropylthioxanthone, and 4-isopropylthioxanthone. Representative examples of commercially available products include DBA and DEA (manufactured by Kawasaki Chemical Industries, Ltd.) as anthracene-based sensitizers, and DETX and ITX (manufactured by Lambson) as thioxanthone-based sensitizers. The content of the sensitizer is not particularly limited, but is preferably 0.5% by mass or more, and more preferably 0.8% by mass or more, based on the entire active energy ray curable composition. The content of the sensitizer is preferably 5.0% by mass or less, and more preferably 3.0% by mass or less, based on the total amount of the active energy ray-curable composition. When the content of the sensitizer is within this range, the curability of the active energy ray-curable composition is excellent, the content of low molecular weight components in the obtained cured product is low, and the durability and yellowing resistance are good. EXAMPLES

[0050] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following, "parts" and "%" are all by mass unless otherwise specified.

[0051] The types and numbers of ethylenically unsaturated groups, the number of benzophenone groups, molecular weights, etc. of the polymerizable photoinitiators (A-1) to (A-18) used in the examples, and the general-purpose photoinitiators (D-1) to (D-4) used in the comparative examples are shown in Table 1. (A-1) to (A-4) and (D-1) to (D-4) are commercially available products as shown below, and (A-5) to (A-18) were synthesized by the method described in Patent Document 3. A-1: 4-Methacryloyloxybenzophenone A-2: 2-hydroxy-4-(acryloyloxy)benzophenone A-3: 2-Hydroxy-4-(methacryloylamino)benzophenone A-4: 2-Hydroxy-4-[2-(acryloylamino)ethoxy]benzophenone D-1: Benzophenone D-2: Acrylic acid (1,1-dimethyl-2-oxo-2-phenylethyl) ester D-3: Omnipol 910 (manufactured by IGM Resins, molecular weight 1039) D-4: Speed ​​Cure 7005 (manufactured by Lambson, molecular weight 1300)

[0052] [Table 1]

[0053] The polymerizable compound (B) and other components (C) used in the examples and comparative examples are shown below. <Polymerizable compound (B)> (1) Monofunctional unsaturated compound having a covalent bond between a heteroatom and a hydrogen atom (b1) b1-1: 2-Hydroxyethylacrylamide (manufactured by KJ Chemicals Co., Ltd., registered trademarks "Kohshylmer" and "HEAA") b1-2: N-isopropylacrylamide (manufactured by KJ Chemicals Co., Ltd., registered trademarks "Kohshylmer" and "NIPAM") b1-3: N-phenylacrylamide (KJ Chemicals Co., Ltd., registered trademark "Kohshylmer") b1-4: Dopamine (meth)acrylamide (manufactured by KJ Chemicals Co., Ltd., registered trademark "Kohshylmer") b1-5: 3-(meth)acrylamidophenylboronic acid (KJ Chemicals, registered trademark "Kohshylmer") b1-6: 3-Hydroxypropyl methacrylamide (KJ Chemicals Co., Ltd., registered trademark "Kohshylmer") b1-7: Diacetone acrylamide (KJ Chemicals Co., Ltd., registered trademark "Kohshylmer") b1-8: methacrylic acid B1-9: Hydroxyethyl acrylate B1-10: 4-hydroxybutyl acrylate b1-11: N-methylacrylamide (KJ Chemicals Co., Ltd., registered trademark "Kohshylmer") B1-12: 2-Methacryloyloxyethyl acid phosphate (2) Polyfunctional unsaturated compounds having a covalent bond between a heteroatom and a hydrogen atom (b2) b2-1: Dipentaerythritol pentaacrylate b2-2: Quick Cure 8100 (UV-curable urethane oligomer (registered trademark "Quick Cure", manufactured by KJ Chemicals) B2-3: Diallylamine b2-4: Quick Cure 7100 (UV-curable urethane oligomer (registered trademark "Quick Cure", manufactured by KJ Chemicals) B2-5: Allyl methacrylamide b2-6: UV-6640B (bifunctional urethane acrylate, manufactured by Mitsubishi Chemical Corporation) b2-7: Bisphenol A epoxy acrylate oligomer (Miramer PE-210, manufactured by MIWON) b2-8: UV-3000B (bifunctional urethane acrylate, manufactured by Mitsubishi Chemical Corporation) B2-9: 1,3-diallyloxy-2-propanol B2-10: Ethylenebisdiacrylamide (3) Monofunctional or polyfunctional unsaturated compounds that do not have a covalent bond between a heteroatom and a hydrogen atom (b3) b3-1: Diethylacrylamide (manufactured by KJ Chemicals Co., Ltd., registered trademarks "Kohshylmer" and "DEAA") b3-2: Acryloylmorpholine (manufactured by KJ Chemicals Co., Ltd., registered trademarks "Kohshylmer" and "ACMO") b3-3: Dimethylacrylamide (manufactured by KJ Chemicals Co., Ltd., registered trademarks "Kohshylmer" and "DMAA") b3-4: 4-t-Butylcyclohexyl acrylate (KJ Chemicals Co., Ltd., registered trademark "Kohshylmer") B3-5: Isobornyl acrylate B3-6: Tetrahydrofurfuryl acrylate B3-7: Benzyl acrylate b3-8: Ethyl carbitol acrylate (SR256, manufactured by Sartomer) b3-9: N-vinylcaprolactam b3-10: Hexanediol diacrylate (Kyoeisha Chemical Co., Ltd., Light Acrylate 1,6HX-A) B3-11: Ethoxylated (3) trimethylolpropane triacrylate (SR454, manufactured by Sartomer Corporation) <Other ingredients (C)) C-1: Disproportionated rosin (polymer, 100% biomass, product name: dehydroabietic acid, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) C-2: 2,4-diethylthioxanthone (sensitizer, manufactured by Lambson) C-3: BYK-331 (leveling agent, polyether-modified polydimethylsiloxane, manufactured by BYK Chemie) C-4: NX-061 Green (pigment dispersion, manufactured by Dainichiseika Color & Chemicals Co., Ltd.) C-5: Carbon black dispersion (Mitsubishi Chemical Corporation) C-6: MEK-ST-40 (colloidized silica dispersion, manufactured by Nissan Chemical Industries, Ltd.) C-7: VALIFAST BLUE1613 (manufactured by Orient Chemical Industries Co., Ltd.) C-8: Leoloseal QS-30 (Tokuyama Corporation) C-9: Inorganic filler (titanium oxide)

[0054] Examples 1 to 24 and Comparative Examples 1 to 8 (Preparation and Evaluation of Active Energy Ray-Curable Compositions) Using the polymerizable photoinitiator (A) or photopolymerization initiator (D), polymerizable compound (B) and other components (C) shown in Table 1, various components were weighed out in the proportions shown in Tables 2 and 3, and mixed at 25°C for 30 minutes to obtain active energy ray-curable compositions of Examples 1 to 24 and Comparative Examples 1 to 8. Using each of the obtained compositions, compatibility, curability, the content of low molecular weight components in the obtained cured product, and durability of the cured product were evaluated by the following methods, and the results are shown in Tables 2 and 3.

[0055] <Compatibility evaluation> The state of the prepared active energy ray-curable composition was visually observed, and the compatibility was evaluated into three stages. ○: No precipitate or turbidity, completely dissolved and transparent. △: Slightly cloudy. ×: Sediment or turbidity is present.

[0056] <Curability evaluation (365nm, 385nm and 405nm)> The obtained active energy ray curable composition was applied to the easy-adhesion treated surface of a 100 μm-thick PET film ("Cosmoshine A-4100" manufactured by Toyobo) using a bar coater so that the film thickness was 30 μm, and then the coating film was cured by irradiating it with ultraviolet light. The cumulative light amount required for the cured product to lose tack when touched was determined, and the curability was evaluated into four stages. The following three types of ultraviolet irradiating lamps 1) to 3) were used. The lower the cumulative light amount required for the tack to disappear (complete curing), the higher the curability. 1) UV LED lamp: Wavelength 365 nm, Illuminance 1000 mW / cm 2 2) UV LED lamp: Wavelength 385 nm, Illuminance 1000 mW / cm 2 3) UV LED lamp: Wavelength 405 nm, Illuminance 1000 mW / cm 2 ◎: Accumulated light intensity 1000mJ / cm 2 If it is less than this the tack will be gone. ○: Accumulated light intensity 1000mJ / cm 2 More than 3000mJ / cm 2 If it is less than this the tack will be gone. △: Accumulated light intensity 3000mJ / cm 2 More than 20000mJ / cm 2 If it is less than this the tack will be gone. ×: Accumulated light intensity 20000mJ / cm 2 But the tack remains.

[0057] <Evaluation of the content of low molecular weight components in the cured product> The obtained active energy ray curable composition was applied to a heavy release separator (silicone-coated PET film), and the light release separator (silicone-coated PET film) was laminated to a film thickness of 100 μm using a tabletop roll laminator (RSL-382S manufactured by Royal Sovereign) while being careful not to trap air bubbles, and ultraviolet light was irradiated (UV LED lamp: wavelength 365 nm, accumulated light amount 10,000 mJ / cm 2 ) and size 5cm 2 Three test pieces were cut out, dried at 90°C for 2 minutes, and weighed as a cured film for evaluating the content of low molecular weight components. 25 g of acetone and the cured film for evaluating the content of low molecular weight components were placed in a brown glass bottle that is not transparent to ultraviolet rays, and the glass bottle was sealed and rotated at 30°C for 48 hours to extract the soluble components in the cured film. The acetone solution was then filtered through a 0.45 μm filter, and the content of low molecular weight components with a number average molecular weight of less than 1000 was quantified using a high performance liquid chromatograph (HPLC). The content of low molecular weight components was calculated using the following formula and evaluated according to the following criteria. Content (%) = (mass of extracted low molecular weight components / mass of cured film before extraction) x 100% ⊚: The content of low molecular weight components is less than 2%. ◯: The content of low molecular weight components is 2% or more and less than 5%. △: The content of low molecular weight components is 5% or more and less than 10%. ×: The content of low molecular weight components is 10% or more.

[0058] <Durability evaluation of cured product> A 75 μm-thick heavy release PET film (Toyobo Co., Ltd., polyester film E7001) was attached to a horizontally placed glass plate, a 1 mm-thick spacer with an internal dimension of 50 mm × 20 mm was placed, and the active energy ray-curable composition obtained in each Example and Comparative Example was filled inside the spacer. Then, a 50 μm-thick light release PET film (Toyobo Co., Ltd., polyester film E7002) was placed on top of the active energy ray-curable composition, and ultraviolet light was irradiated (UV LED lamp: wavelength 385 nm, accumulated light amount 10,000 mJ / cm 2 The release PET films on both sides were then removed to prepare a cured product, which was then used as a test piece, which was then left to stand in a thermo-hygrostat chamber set at a temperature of 40° C. and a humidity of 50% RH for 168 hours, and the surface of the test piece was visually observed for bleed-out and deformation, and evaluated according to the following criteria. ⊚: No bleeding or deformation was observed. ○: Slight bleed-out or deformation is observed. Δ: Both bleed-out and deformation are slightly observed, or either one is severe. ×: The cured product became a viscous liquid.

[0059] [Table 2]

[0060] [Table 3]

[0061] As is clear from the results of Tables 2 and 3, the active energy ray curable compositions of each Example have good compatibility, and have high curability against light rays of 365 nm, 385 nm, and 405 nm. Even when cured using a safe UV LED lamp, the content of low molecular weight components in the cured product is extremely low, and a cured product that can provide both safety and durability can be obtained. On the other hand, in Comparative Example 1, in which hydrogen abstraction type benzophenone (D-1) was used as a photopolymerization initiator, Comparative Example 2, in which a photopolymerization initiator (D-2) having a polymerizable acrylate group and an intramolecular cleavage type acrylic acetophenone group was used, and Comparative Example 3, in which both D-1 and D-2 were used, it was possible to adjust the curability against light rays of the three wavelengths to some extent by increasing the combination and content of the photopolymerization initiator, but the curability against long wavelength light rays of 385 nm and 405 nm was not satisfactory. The cured products obtained in Comparative Examples 1 to 3 all had a high content of low molecular weight components, and the safety and durability of the cured products were low. The photopolymerization initiator (D-2) has an acrylate group as a polymerizable functional group, but since the same mole of decomposition product is generated at the same time as the generation of active radicals, the decomposition product remains as a low molecular weight component in the cured product, and the durability of the cured product is low. Furthermore, in Comparative Examples 4 and 5 using an intramolecular cleavage type oligomer (D-3) as a photopolymerization initiator, curability at 365 nm is observed, but when the content is low (Comparative Example 4), the curability at long wavelengths of 385 nm and 405 nm is greatly reduced, while when the content is high (Comparative Example 5), the compatibility is reduced. The photopolymerization initiator (D-3) is a photopolymerization initiator with a molecular weight of 1000 or more, but is an intramolecular cleavage type, so low molecular weight components are generated with the generation of radicals. As a result, the content of low molecular weight components in the cured product is high, and the durability of the cured product is also low. In Comparative Examples 6 and 7, in which a hydrogen abstraction type polymer (D-4) was used as a photopolymerization initiator, the curability was low at all wavelengths of 365 nm, 385 nm, and 405 nm. In Comparative Example 7, in which the content of D-4 was increased, not only was no improvement in curability observed, but the compatibility of the curable composition was poor, a large amount of low molecular weight components remained in the cured product, and the durability of the cured product was also poor.Comparative Example 8 contained (A-1) as a polymerizable photoinitiator but did not contain the polymerizable compound (B), and therefore had low curability to light of each wavelength, and in particular, the durability of the obtained cured product was very low. As explained above, it is believed that the different physical properties between these Examples and Comparative Examples are due to the interaction between the polymerizable photoinitiator (A) and the polymerizable compound (B) used in the active energy ray-curable composition of the present invention.

[0062] Examples 25 to 36 and Comparative Examples 9 to 12 (Preparation and Evaluation of Active Energy Ray-Curable Ink Compositions) According to the proportions shown in Table 4 (solid content conversion), the active energy ray curable composition obtained in Table 2, the polymerizable photoinitiator (A) or photopolymerization initiator (D) shown in Table 1, and other components were weighed and mixed uniformly at room temperature to prepare an ink composition. Using the prepared ink composition, viscosity measurement was performed by the following method, and pigment dispersibility evaluation was also performed when a pigment dispersion liquid was contained. The active energy ray curability of the ink composition and the surface drying property of the obtained cured film were evaluated, and further inkjet printing was performed, and the ink discharge stability and the clarity of the printed matter were evaluated as printability. The results of these evaluations are shown in Table 4.

[0063] <Viscosity measurement and evaluation> The viscosity of the ink composition was measured in accordance with JIS K5600-2-3 using a cone-plate viscometer (RE550 viscometer manufactured by Toki Sangyo Co., Ltd.) As an ink composition for inkjet printing, the viscosity was evaluated into the following four levels. ◎: Less than 5~100mPa s ○: Less than 100-500 mPa s △: Less than 500~2000mPa·s ×:2000mPa·s or more

[0064] <Evaluation of pigment dispersibility> The prepared ink compositions were visually observed for pigment aggregation and precipitation immediately after preparation and after standing for 2 months, and the pigment dispersibility was evaluated into the following four stages. ⊚: No pigment aggregation or precipitation was observed immediately after preparation or after leaving the mixture to stand for 2 months. ◯: No precipitation was observed immediately after preparation, but slight precipitation of pigment was observed after leaving it to stand for 2 months. △: Slight pigment aggregation and precipitation were observed immediately after preparation, but after leaving the mixture to stand for 2 months, aggregation and precipitation of the pigment were clearly observed. ×: Pigment aggregation and precipitation were clearly observed even immediately after preparation.

[0065] Method for producing printed matter by ultraviolet irradiation The obtained ink composition was applied to a 100 μm-thick PET film using a bar coater (RDS12) (film thickness after drying: 20 μm), and then irradiated with ultraviolet light (UV LED lamp: wavelength 385 nm, illuminance 1000 mW / cm 2 ) to produce a printed matter.

[0066] <Evaluation of Curability of Ink Composition> When a printed matter was produced by the above method, the integrated amount of light until the ink composition was completely cured (until it became non-sticky) was measured, and the curability was evaluated according to the following criteria. ◎: 1000mJ / cm 2 Completely hardened with ○: 1000~2000mJ / cm 2 Completely hardened with △: 2000~5000mJ / cm 2 Completely hardened with ×: 5000mJ / cm until complete curing 2 More than this is required

[0067] <Surface drying evaluation> The print produced by the above method was left to stand for 5 minutes in an environment with a room temperature of 23°C and a relative humidity of 50%, then high-quality paper was placed over the printed surface and a load of 1 kg / cm2 was applied for 1 minute. The degree of ink transfer to the paper was evaluated according to the following criteria. ⊚: The ink was dry and not transferred to the paper at all. ○: The ink was dried and there was a small amount of transfer onto the paper. △: The ink was almost dry and was transferred to the paper. ×: The ink was barely dried and a large amount was transferred to the paper.

[0068] Inkjet printing and printability evaluation The prepared ink composition was filled into a commercially available inkjet printer (LuxelJet UV350GTW manufactured by Fujifilm Corporation), and a solid image was printed on coated paper. The printability of the ink was evaluated by the following method.

[0069] <Evaluation of ejection stability> The printing condition of the obtained print was visually observed and evaluated according to the following criteria. ⊚: No missing nozzles, good printing. Good: There is a slight nozzle dropout. △: Nozzle missing occurs over a wide area. ×: Non-ejection occurred.

[0070] <Clarity evaluation> The image clarity of the prints obtained from the ink compositions containing the pigments was visually observed and evaluated according to the following criteria. ⊚: No ink bleeding was observed and the image was clear. A: There was almost no ink bleeding and the image was good. △: Some ink bleeding was observed. ×: Significant ink bleeding was observed.

[0071] [Table 4]

[0072] The viscosity of the active energy ray curable ink composition of the present invention can be adjusted arbitrarily according to various printing methods such as inkjet printing, offset printing, screen printing, and flexible printing. As is clear from the results in Table 4, the liquid viscosity can be adjusted to be low as an ink composition for inkjet printing, and when a pigment is blended, it has high pigment dispersibility. The reason for such results is that the compatibility between the polymerizable photoinitiator (A) and the polymerizable compound (B) contained in the examples is extremely good, and it is easy to combine low-viscosity monofunctional unsaturated compounds (b1) or (b3) to high-viscosity polyfunctional unsaturated compounds (b2) or (b3). In addition, due to the combination of the polymerizable photoinitiator (A) and the polymerizable compound (B), the ink composition of the examples has high curability, and the surface drying property of the cured film is good because the low molecular weight components in the obtained cured film are small, and the ink ejection stability and the clarity of the printed matter, which are printing suitability as an inkjet ink composition, were good. On the other hand, the ink compositions of the comparative examples were all insufficient in at least one of viscosity, pigment dispersibility, curability, surface drying property, and ejection stability, and thus were not satisfactory in terms of suitability for inkjet printing.

[0073] Examples 37 to 45 and Comparative Examples 13 to 15 (Preparation and Evaluation of Active Energy Ray-Curable Ink Compositions for Three-Dimensional Modeling) According to the proportions (solid content conversion) shown in Table 5, the active energy ray curable composition obtained in Table 2, the polymerizable photoinitiator (A) or photopolymerization initiator (D) shown in Table 1, and other components were weighed and mixed uniformly at room temperature to prepare an ink composition for three-dimensional modeling. Using the ink composition for three-dimensional modeling, a three-dimensional model was produced by the following method, and the cure shrinkage rate during modeling was evaluated. In addition, the strength, heat resistance, water resistance, and modeling accuracy of the obtained cured product were evaluated. These evaluation results are shown in Table 5.

[0074] <Strength evaluation> A 75 μm-thick heavy release PET film (Toyobo Co., Ltd., polyester film E7001) was attached to a horizontally placed glass plate, and a 1 mm-thick spacer punched into a No. 2 dumbbell shape conforming to JIS K6251 was placed on the inside of the spacer. The ink composition for three-dimensional modeling obtained in each Example and Comparative Example was filled inside the spacer, and then a 50 μm-thick light release PET film (Toyobo Co., Ltd., polyester film E7002) was placed on top of the spacer and ultraviolet light was irradiated from both sides (UV LED lamp: wavelength 365 nm, illuminance 10 mW / cm). 2 , cumulative light intensity 5000mJ / cm 2 ) to cure the ink composition for three-dimensional modeling. Thereafter, the release PET films on both sides were removed to obtain test pieces of the cured product for the examples and the cured product for the comparative examples. In accordance with JIS K7161, the tensile strength was measured using a bench-top precision universal testing machine (Autograph AGS-X manufactured by Shimadzu Corporation) at a temperature of 25°C, a tensile speed of 10 mm / min, and a chuck distance of 50 mm, and the strength was evaluated according to the following criteria. ◎: Tensile strength 40MPa or more ○: Tensile strength 30MPa or more, less than 40MPa △: Tensile strength 20MPa or more and less than 30MPa ×: Tensile strength less than 20MPa

[0075] <Evaluation of resistance to curing shrinkage> The cure shrinkage rate was calculated from the change in density before and after curing of the ink composition for three-dimensional modeling according to JIS K5600 2-4, as shown in the following formula (1). The density of the ink composition for three-dimensional modeling before and after curing was measured according to JIS K7112 using an electronic specific gravity meter (MDS-300 manufactured by Alpha Mirage Co., Ltd.). The cured product was prepared in the same manner as the test piece for the tensile test. The following evaluations were made from the obtained cure shrinkage rate. (Cure shrinkage rate) = (Ds-Dl) / Dl x 100 Formula (1) (In the formula, Ds is the density of the ink composition for three-dimensional modeling after curing, and Dl is the density of the ink composition for three-dimensional modeling before curing.) ◎: Curing shrinkage rate less than 6% ○: Curing shrinkage rate 6% or more and less than 7% △: Curing shrinkage rate 7% or more and less than 8% ×: Curing shrinkage rate 8% or more

[0076] <Heat resistance evaluation> Cured products were prepared in the same manner as the test pieces for the tensile tests, and the glass transition temperature (Tg) of the cured products was measured using a differential scanning calorimeter (DSC-60plus, manufactured by Shimadzu Corporation). The heat resistance was evaluated based on the measured glass transition temperature (Tg) of the cured products according to the following criteria. ◎: Cured product Tg 60℃ or more ○: Cured product Tg 40℃ or higher but lower than 60℃ ×: Cured product Tg below 40°C

[0077] <Water resistance evaluation> A 75 μm-thick heavy-release PET film (Toyobo Co., Ltd., polyester film E7001) was attached to a horizontally placed glass plate, a 10 mm-thick spacer with an internal dimension of 10 cm × 1 cm was placed, and the ink composition for three-dimensional modeling obtained in each of the Examples and Comparative Examples was filled to a thickness of 1 mm inside the spacer. The surface was smoothed by keeping the ink composition at 60°C for 30 seconds, and then irradiated with ultraviolet light (UV LED lamp: wavelength 365 nm, illuminance 10 mW / cm 2 , cumulative light intensity 5000mJ / cm 2 ) and the ink composition for three-dimensional modeling was cured to obtain a cured product having a length of 10 cm, a width of 1 cm, and a thickness of 1 mm. The weight of the obtained cured product immediately after production was measured, and then it was immersed in a beaker containing 100 ml of water, and the weight after immersion was measured one day later. The weight immediately after production and the weight after immersion were substituted into the following formula to measure the water absorption rate, and the water resistance was evaluated according to the following criteria. Water absorption rate (%) = (weight after immersion for 1 day - weight immediately after production) / weight immediately after production × 100% ◎: Water absorption rate is less than 2% ○: Water absorption rate is 2% or more and less than 2.5% △: Water absorption rate is 2.5% or more and less than 3% ×: Water absorption rate is 3% or more

[0078] <Modeling accuracy evaluation> A 75 μm-thick heavy-release PET film (Toyobo Co., Ltd., polyester film E7001) was attached to a horizontally placed glass plate, a 10 mm-thick spacer with an internal dimension of 10 mm × 10 mm was placed, and the ink composition for three-dimensional modeling obtained in each of the Examples and Comparative Examples was filled to a thickness of 1 mm inside the spacer. The surface was smoothed by keeping the temperature at 60°C for 30 seconds, and then irradiated with ultraviolet light (UV LED lamp: wavelength 365 nm, illuminance 10 mW / cm). 2 , cumulative light intensity 1000mJ / cm 2 ) and the ink composition for three-dimensional modeling was cured. Thereafter, the ink composition for three-dimensional modeling was filled to a thickness of 1 mm, and the curing process was repeated 10 times in total to obtain a cured product of 10 x 10 x 10 mm. The height of the obtained cured product was measured. In addition, the side surface of the obtained cured product was visually observed. These results were combined and the modeling accuracy was evaluated according to the following criteria. ◎: Height is less than 10 mm ± 0.1 mm and the sides are smooth. ○: Height is 10mm ±0.1mm or more but less than ±0.2mm, or there are slight irregularities on the side. △: Height is 10mm ±0.2mm or more but less than ±0.3mm, or there are slight irregularities on the sides. ×: Height is 10mm±0.3mm or more, or there are obvious irregularities on the side.

[0079] [Table 5]

[0080] As is clear from the results in Table 5, in the three-dimensional optical modeling using the ink composition for three-dimensional modeling of the Examples, since both the polymerizable photoinitiator (A) and the polymerizable compound (B) are polymerizable, it is possible to obtain a modeled object having sufficient strength, water resistance, and heat resistance, while at the same time controlling the shrinkage during curing to a low level, and to obtain a modeled object with high accuracy. In addition, as described above, the content of low molecular weight components in the modeled object obtained in the Examples is low, and the modeled object is characterized by high strength, water resistance, and heat resistance. Modeled objects having such good properties were not obtained from the compositions of the Comparative Examples.

[0081] Examples 46 to 51 and Comparative Examples 16 to 18 (Preparation and Evaluation of Active Energy Ray-Curable Nail Cosmetic Compositions) Nail cosmetic compositions were prepared by weighing out the active energy ray curable composition obtained in Table 2, the polymerizable photoinitiator (A) or the photopolymerization initiator (D) shown in Table 1, and other components in the proportions (based on solids content) shown in Table 6, and mixing them uniformly at room temperature. The nail cosmetic compositions were evaluated for curability, adhesion to nylon substrates, and surface hardness and surface gloss of the resulting cured films. The results are shown in Table 6.

[0082] <Evaluation of the hardening properties of nail cosmetics> The active energy ray curable nail cosmetic compositions prepared in the examples and comparative examples were applied to a nylon 6 test piece ("SHT-N6(NC)" manufactured by Toray Plastics Precision Co., Ltd.) using a separator to give a film thickness of 100 μm, and then irradiated with ultraviolet light using a UV LED lamp for gel nails (manufactured by Beauty Nailer, wavelength 405 nm, 48 W). After curing, the surface was wiped with tissue paper to produce a cured film. The time it took for the surface of the cured film to lose its tackiness when touched was evaluated into four stages. The shorter the time required for the tackiness to disappear, the higher the curability. ◎: Tack disappears in less than 1 minute. ○: Tack disappears in 1 minute or more but less than 3 minutes. △: The tack disappears in 3 minutes or more but less than 10 minutes. ×: The tack does not disappear even after 10 minutes or more.

[0083] <Adhesion (nylon substrate) evaluation> The photocurable nail cosmetic compositions obtained in each of the Examples and Comparative Examples were applied to a nylon 6 test piece in the same manner as above, and a cured film was produced by irradiating light for 3 minutes. Using the obtained cured film, 100 1 mm square checkerboard patterns were made with a cutter knife in accordance with JIS K 5600, and the number of checkerboard patterns remaining on the test piece when a commercially available cellophane tape was attached and then peeled off was evaluated into 4 levels, and the results are shown in Table 6. The more checkerboard patterns remaining on the test piece, the higher the adhesion. ◎: The number of remaining squares is 100. ○: The number of remaining grids is 90 to 99. △: The number of remaining squares is 60 to 89. ×: The number of remaining squares is less than 60.

[0084] <Evaluation of surface hardness of cured film> Using the cured films of each Example and Comparative Example obtained in the adhesion evaluation, a 750 g load was applied to the surface of the film with an HB hardness pencil at an angle of 45° and pulled, and the presence or absence of peeling and scratches was visually confirmed and rated into three levels, and the results are shown in Table 6. The fewer scratches and peeling, the higher the surface hardness. A: No scratches or peeling occurred. The surface hardness is pencil hardness HB or higher. △: No peeling occurred, but scratches occurred. ×: Peeling occurred.

[0085] <Surface gloss evaluation> The surface gloss of the cured films of the Examples and Comparative Examples obtained in the adhesion evaluation was visually observed and evaluated according to the following criteria. ○: Shiny. △: Light reflection can be confirmed, but there is some cloudiness. ×: No light reflection was observed and there was no gloss.

[0086] [Table 6]

[0087] As is clear from the results in Table 6, the active energy ray curable nail cosmetic composition of the embodiment had excellent curability compared to a commercially available UV lamp for gel nails, while having high adhesion to a nylon substrate (a material having many amide bonds like nails, which are mainly composed of proteins). From these results, it can be seen that the active energy ray curable nail cosmetic composition of the present invention can be suitably used as a gel nail base gel that is directly applied to nails. In addition, since the content of low molecular weight components in the obtained cured film is low, the surface hardness and surface gloss of the cured film are good, and it can also be suitably used as a gel nail top coat. On the other hand, the active energy ray curable nail cosmetic composition of the comparative example had low curability, and since the cured film contained a large amount of low molecular weight components, the surface hardness and surface gloss of the cured film were low.

[0088] Examples 52 to 59 and Comparative Examples 19 to 21 (Preparation and Evaluation of Active Energy Ray-Curable Pressure-Sensitive Adhesive Compositions) The active energy ray curable composition obtained in Table 2, the polymerizable photoinitiator (A) or photopolymerization initiator (D) shown in Table 1, and other components were weighed out in accordance with the proportions (solid content conversion) shown in Table 7, and uniformly mixed at room temperature to prepare a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition was used to prepare a pressure-sensitive adhesive sheet by the following method, and the curability of the pressure-sensitive adhesive composition, adhesion to various substrates, and the transparency, adhesive strength, stain resistance (reworkability), durability, and light yellowing resistance of the obtained pressure-sensitive adhesive sheet were evaluated. The results are shown in Table 7.

[0089] <Adhesive curing evaluation> A 75 μm-thick heavy release PET film (Toyobo Co., Ltd., polyester film E7001) was attached to a flat glass plate, a 1 mm-thick spacer with an internal dimension of 60 mm×100 mm was placed, and the active energy ray-curable pressure-sensitive adhesive composition prepared in the Examples and Comparative Examples was filled inside the spacer. A 50 μm-thick light release PET film (Toyobo Co., Ltd., polyester film E7002) was then placed on top of the active energy ray-curable pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition was then heated at a wavelength of 385 nm and an output of 100 mW / cm. 2 The UV LED lamp has an integrated light output of 3000mJ / cm 2The pressure-sensitive adhesive composition was cured by irradiating the adhesive composition so that the release PET films on both sides were then removed, and the cured product was touched to evaluate the curability into three stages. ◯: A cured product that was able to maintain its shape was obtained, and the cured product was tacky when touched, but no liquid uncured product was attached. Δ: A cured product that was able to maintain its shape was obtained, and the cured product was tacky when touched, but some liquid uncured material was attached. ×: Curing was insufficient, a cured product capable of maintaining its shape was not obtained, and a large amount of adherent liquid residue was observed.

[0090] <Preparation of adhesive sheets and evaluation of adhesion> The active energy ray-curable adhesive composition prepared above was coated on various plate- or film-shaped substrates (substrates) shown below, and the substrates were laminated using a tabletop roll laminator (Royal Sovereign's RSL-382S) with a light release separator (silicone-coated PET film) to prevent air bubbles from being trapped, so that the adhesive layer had a thickness of 50 μm. The substrates were then irradiated with ultraviolet light (UV LED lamp: wavelength 385 nm, illuminance 1000 mW / cm 2 , cumulative light intensity 2000mJ / cm 2 ) was applied. The light release separator was then peeled off to obtain an adhesive sheet consisting of an adhesive layer and a substrate. Using the obtained adhesive sheet, 100 1 mm squares were created in accordance with JIS K 5600, cellophane tape was attached, and the tape was peeled off in one go. The number of squares with adhesive layer remaining on the substrate side was counted, and adhesion was evaluated according to the following criteria. Substrate (substrate) PET: Toyobo E5100 (corona treated surface) PMMA: Kuraray Comoglass P PC: Takiron C-I PC1600 PVC: Sekisui Chemical's Esbilon Plate I-500 Glass (GL): Corning Eagle XG Evaluation criteria ◎: No peeling after 100 pieces ○: 95-99 pieces, no peeling △: 70-94 pieces, no peeling ×: 0 to 69 pieces, no peeling

[0091] <Adhesive strength evaluation> An adhesive sheet was prepared in the same manner as above, and the adhesive layer was transferred to the adhesive surface of an easy-to-adhere PET film (Cosmoshine A4160 manufactured by Toyobo) under conditions of a temperature of 23°C and a relative humidity of 50%, and pressure-applied by two reciprocating motions using a pressure roller weighing 2 kg, and left for 30 minutes in the same atmosphere. Thereafter, the 180° peel strength (N / 25 mm) was measured at a peel speed of 300 mm / min in accordance with JIS Z0237 using a tensile tester (device name: Tensilon RTA-100 manufactured by ORIENTEC Co., Ltd.), and evaluated according to the following criteria. ◎:20(N / 25mm) or more ○: 10 (N / 25mm) or more, less than 20 (N / 25mm) △: 5 (N / 25mm) or more, less than 10 (N / 25mm) ×: Less than 5 (N / 25mm)

[0092] <Transparency evaluation of adhesive sheets> Using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., NDH-2000), the total light transmittance of the glass substrate was measured in accordance with JIS K 7105. An adhesive sheet of a glass substrate was prepared in the same manner as above, and an adhesive layer was transferred to the glass substrate under conditions of a temperature of 23°C and a relative humidity of 50%, and the total light transmittance of the glass substrate and the adhesive layer was measured. Thereafter, the transmittance of the glass plate was subtracted to calculate the transmittance of the adhesive layer itself, and the transparency was evaluated in four stages as follows. ◎: Transmittance is 90% or more ○: Transmittance is 85% or more and less than 90% △: Transmittance is 50% or more and less than 85% ×: Transmittance is less than 50%

[0093] <Contamination resistance (reworkability) evaluation> An adhesive sheet was prepared in the same manner as in the measurement of adhesive strength described above, and left at 80°C for 24 hours. After the adhesive sheet was peeled off, the contamination of the surface of the base film (remaining adhesive layer (glue)) was visually observed and evaluated according to the following criteria. ◎: No contamination (no adhesive residue). ○: There is very little contamination. △: Slight contamination. ×: Contamination occurred (glue residue remained).

[0094] <Evaluation of light yellowing resistance> An adhesive sheet of a glass substrate was prepared in the same manner as above, and set in a xenon fade meter (SC-700-WA: manufactured by Suga Test Instruments Co., Ltd.) and measured at 70 mW / cm 2 After irradiation with ultraviolet light of intensity of 1000 for 120 hours, the discoloration of the adhesive layer on the adhesive sheet was visually observed and evaluated according to the following criteria. ⊚: No yellowing was observed with the naked eye. ○: Yellowing is very slight and visible. △: Yellowing is visually confirmed. ×: Obvious yellowing is visually observed.

[0095] <Durability evaluation> An adhesive sheet was prepared on a glass substrate in the same manner as above, and was then held for 100 hours under conditions of a temperature of 85°C and a relative humidity of 85%, after which the adhesive layer was visually inspected for any floating or peeling, air bubbles, or cloudiness, and evaluated according to the following criteria. ◎: Transparent, no floating, peeling or air bubbles. ×: Cloudy, floating, peeling, or air bubbles are present.

[0096] [Table 7]

[0097] As is clear from the results in Table 7, the active energy ray curable adhesive composition of the examples had high curability, and the adhesive sheet obtained by curing it had high transparency and good adhesion and adhesion (adhesive strength) to various materials. In particular, the cured product (adhesive sheet) obtained from the active energy ray curable adhesive composition of the present invention had a low content of low molecular weight components, so the adhesive residue resistance when the cured product was peeled off from the substrate, as well as the yellowing resistance and durability of the cured product were good. On the other hand, the curability of the composition of the comparative example was low and curing did not progress sufficiently, so both the adhesion and adhesion to materials were low, and the cured product contained a large amount of low molecular weight components such as remaining uncured components or decomposition products generated by ultraviolet irradiation, so the contamination resistance, yellowing resistance and durability of the cured product were also low.

[0098] Examples 60 to 64 and Comparative Examples 22 to 24 (Preparation and Evaluation of Active Energy Ray-Curable Adhesive Compositions) The active energy ray curable composition obtained in Table 2, the polymerizable photoinitiator (A) or the photopolymerization initiator (D) shown in Table 1, and other components were weighed out in accordance with the proportions (solid content conversion) shown in Table 8, and mixed uniformly at room temperature to prepare an adhesive composition. Using the adhesive composition, a laminated film bonded by the following method was produced, and the curability of the adhesive composition, the adhesive strength to various substrates, and the durability of the obtained laminated film were evaluated. The results are shown in Table 8.

[0099] <Evaluation of Curability of Adhesive Composition> A PET film (Toyobo Co., Ltd., polyester film E5100) was placed on a horizontally placed glass plate with the corona-treated surface facing up, and the active energy ray-curable adhesive composition of the Examples and Comparative Examples was applied to a thickness of 20 μm using a bar coater No. 12. A 50 μm-thick easy-release PET film (Toyobo Co., Ltd., polyester film E7002) was then placed on top of the applied adhesive. The applied adhesive was heated at a wavelength of 365 nm and an output of 50 mW / cm. 2 The adhesive composition was cured by irradiating it with ultraviolet light using a UV LED lamp. Thereafter, the release PET film was removed, and the presence or absence of tackiness on the surface of the cured film was confirmed. The curability was evaluated according to the following criteria based on the integrated amount of light required until the tackiness disappeared. ◎: Accumulated light intensity 1000mJ / cm 2 The tack disappeared in less than ○: Accumulated light intensity 1000mJ / cm 2 Above 2000mJ / cm 2 The tack disappeared in less than △: Accumulated light intensity 2000mJ / cm 2 Above 5000mJ / cm 2 The tack disappeared in less than ×: Accumulated light intensity 5000mJ / cm 2 Even with all this, the tack remained.

[0100] <Laminated film production and adhesive strength evaluation> The active energy ray-curable adhesive composition prepared above was coated onto various plate- or film-shaped substrates (substrates) shown below, and the substrates were laminated using a tabletop roll laminator (Royal Sovereign's RSL-382S) with a Toyobo Co., Ltd. E5100 (corona-treated surface) while being careful not to trap air bubbles, so that the adhesive layer had a thickness of 20 μm. The substrates were then irradiated with ultraviolet light (wavelength 365 nm, UV LED lamp output 50 mW / cm). 2 , Accumulated light quantity: 5000mJ / cm 2 Thereafter, the 180° peel strength (N / 25 mm) was measured at a peel speed of 300 mm / min in accordance with JIS Z0237 using a tensile tester (apparatus name: Tensilon RTA-100, manufactured by ORIENTEC), and the adhesive strength was evaluated according to the following criteria. Substrate (substrate) PET (untreated): Toyobo E5100 (untreated surface) PMMA: Kuraray Comoglass P PC: Takiron C.I. PC1600 Evaluation criteria ◎:20(N / 25mm) or more ○: 10 (N / 25mm) or more, less than 20 (N / 25mm) △: 5 (N / 25mm) or more, less than 10 (N / 25mm) ×: Less than 5 (N / 25mm)

[0101] <Durability evaluation of laminated film> Similar to the above adhesive strength evaluation, a Toyobo E5100 (corona-treated surface) / PET laminate film was prepared and held for 100 hours under conditions of a temperature of 85°C and a relative humidity of 85%, after which the adhesive layer was visually inspected for lifting, peeling, air bubbles, and cloudiness, and durability was evaluated according to the following criteria. ◎: Transparent, no floating, peeling or air bubbles. ○: There is very little cloudiness, but no lifting, peeling, or air bubbles. △: Slight cloudiness, lifting, peeling, or bubbles. ×: Severe cloudiness, lifting, peeling, or bubbles.

[0102] [Table 8]

[0103] As is clear from the results in Table 8, the active energy ray curable adhesive compositions of the examples had high curability, and the laminated films obtained by curing them had high and good adhesion to various materials. In particular, the cured products (adhesive layers of laminated films) obtained from the active energy ray curable adhesive compositions of the present invention had good durability due to a low content of low molecular weight components, and exhibited properties suitable for adhesives and sealants. On the other hand, the compositions of the comparative examples had low curability and did not cure sufficiently, so that the adhesive strength to the substrate was low, and the durability of the adhesive layer was also low because a large amount of low molecular weight components such as uncured components or decomposition products generated by ultraviolet irradiation remained in the cured products.

[0104] Examples 65 to 67 and Comparative Examples 25 and 26 (Preparation and Evaluation of Active Energy Ray-Curable Coating Agent Compositions) According to the proportions (solid content conversion) shown in Table 9, the active energy ray curable composition obtained in Table 2, the polymerizable photoinitiator (A) or photopolymerization initiator (D) shown in Table 1, and other components were weighed and mixed uniformly at room temperature to prepare a coating composition. Using the coating composition, a coating layer was produced by the following method, and the curability of the coating composition and the adhesion, bending resistance, chemical resistance, scratch resistance, self-repairing property, and durability of the obtained coating layer were evaluated. The results are shown in Table 9.

[0105] <Evaluation of curability of coating composition> A PET film (E5100 manufactured by Toyobo Co., Ltd.) was placed on a flat glass plate with the corona-treated surface facing up, and the active energy ray-curable coating composition of the Examples and Comparative Examples was applied to a thickness of 10 μm using a bar coater No. 6. The coating was then irradiated with ultraviolet light from a metal halide lamp in a nitrogen atmosphere (apparatus: inverter-type conveyor device ECS-4011GX manufactured by I-Graphics, metal halide lamp: M04-L41 manufactured by I-Graphics, ultraviolet irradiance 500 mW / cm). 2 Thereafter, the presence or absence of tackiness on the surface of the cured film was confirmed, and the curability was evaluated as follows based on the integrated amount of light required until the tackiness disappeared. ◎: Accumulated light intensity 1000mJ / cm 2 The tack disappeared in less than ○: Accumulated light intensity 1000mJ / cm 2 Above 2000mJ / cm 2 The tack disappeared in less than △: Accumulated light intensity 2000mJ / cm 2 Above 5000mJ / cm 2 The tack disappeared in less than ×: Accumulated light intensity 5000mJ / cm 2 Even with all this, the tack remained.

[0106] <Coating layer production and adhesion evaluation> The active energy ray-curable coating composition prepared above was placed on a horizontally placed glass plate, and a PET film (E5100 manufactured by Toyobo Co., Ltd.) was placed on the plate so that the corona-treated surface was on the surface. The active energy ray-curable coating composition of each of the Examples and Comparative Examples was applied to a thickness of 20 μm using a bar coater No. 12, and the coating was heated under a nitrogen atmosphere with a UV LED lamp having a wavelength of 365 nm to an illuminance of 500 mW / cm. 2 , cumulative light intensity 5000mJ / cm 2A coating layer was formed on the PET film by irradiating the film with ultraviolet light for 100 seconds. Then, using the obtained coating layer, 100 1 mm squares were created in accordance with JIS K 5600, cellophane tape was attached, and the number of squares with adhesive layer remaining on the substrate side when the tape was peeled off in one go was counted, and the adhesion was evaluated according to the following criteria. ◎: No peeling after 100 pieces ○: 95-99 pieces, no peeling △: 70-94 pieces, no peeling ×: 0 to 69 pieces, no peeling

[0107] <Evaluation of bending resistance of coating layer> A laminate consisting of a PET film and a coating layer prepared in the same manner as in the above adhesion evaluation was prepared, and in accordance with the cylindrical mandrel method described in JIS K-5600, it was brought into contact with a mandrel (10 mmφ) so that the coating layer was on the outside and bent. The coating layer was then visually observed for cracks, and the bending resistance was evaluated according to the following criteria. .circle-solid.: No cracks were observed. ◯: The folded portion was partially whitened. △: Some cracks were observed at the bent portion. ×: Cracks were observed at the bent portion.

[0108] <Chemical resistance evaluation of coating layer> In the same manner as in the above adhesion evaluation, a coating layer was prepared on a PET film, and oleic acid was applied to the surface of the coating layer to a diameter of approximately 1 cm. After keeping the surface at 23°C for 1 hour, it was washed off with a neutral detergent, and the surface condition was observed and the chemical resistance was evaluated according to the following criteria. Absolutely no trace of oleic acid was observed. ○: A very slight white mark is observed on the area where oleic acid was applied. △: The area where oleic acid was applied turned white and swelling was observed on the surface. ×: The area where oleic acid was applied was sticky and surface peeling was observed.

[0109] <Evaluation of scratch resistance of coating layer> In the same manner as in the adhesion evaluation described above, a coating layer was prepared on a PET film, and the surface of the coating layer was rubbed 10 times with #0000 steel wool at a weight of 100 g under conditions of room temperature of 23°C and humidity of 50%, and the surface of the coating layer was visually observed and the scratch resistance was evaluated according to the following criteria. ⊚: No peeling or damage to the coating layer was observed. ○: Slight fine scratches are observed in part of the coating layer. △: Streak-like scratches are observed throughout the entire coating layer. ×: Peeling of the coating layer was observed.

[0110] <Evaluation of self-repairing properties of coating layer> In the same manner as in the adhesion evaluation described above, a coating layer was prepared on a PET film, and the surface of the coating layer was rubbed back and forth 10 times with a brass brush under a load of 100 g at room temperature of 23°C and humidity of 50%, and the surface condition was visually observed, and the self-repairability was evaluated according to the following criteria. ◎: Scratches are repaired within 30 minutes, or no scratches are caused. ○: Damage was observed after 30 minutes, but the damage was restored after 24 hours or by keeping the surface at 60°C for 8 hours. ×: Scratches were observed after 24 hours, and the scratches did not recover even after holding at 60°C for 8 hours.

[0111] <Evaluation of Coating Layer Durability> In the same manner as in the above adhesion evaluation, a coating layer was prepared on a PET film and held for 100 hours under conditions of a temperature of 85°C and a relative humidity of 85%, after which the adhesive layer was visually inspected for lifting, peeling, air bubbles, and cloudiness, and durability was evaluated according to the following criteria. ◎: Transparent, no floating, peeling or air bubbles. ○: There is very little cloudiness, but no lifting, peeling, or air bubbles. ×: Cloudy, floating, peeling, or air bubbles are present.

[0112] [Table 9]

[0113] As is clear from the results in Table 9, the active energy ray curable coating agent composition of the examples has high curability, and the coating layer obtained by curing it exhibits good adhesion, and also has flex resistance and scratch resistance. In particular, the cured product (coat layer) obtained from the active energy ray curable coating agent composition of the present invention has a low content of low molecular weight components, so it also has good durability and exhibits excellent properties for vehicle and indoor and outdoor coating agents. Furthermore, it also exhibits self-repairing properties, and is expected to be applied to self-repairing paints, and is also excellent in chemical resistance, so it can be used as a coating layer for decoration. On the other hand, the composition of the comparative example has low curability and does not cure sufficiently, so it has low adhesion to the substrate, insufficient flex resistance and scratch resistance, and does not exhibit self-repairing properties. Furthermore, since a large amount of low molecular weight components such as uncured components or decomposition products generated by ultraviolet irradiation remained in the cured product, the durability of the coating layer was also low.

[0114] Examples 68 to 70 and Comparative Examples 27 and 28 (Preparation and Evaluation of Active Energy Ray-Curable Dental Compositions) According to the proportions shown in Table 10 (solid content conversion), the active energy ray curable composition obtained in Table 2, the polymerizable photoinitiator (A) or photopolymerization initiator (D) shown in Table 1, and other components were weighed and mixed uniformly at room temperature to prepare an active energy ray curable dental composition. The solubility or dispersibility of the dental composition (when an insoluble inorganic filler, pigment, etc. is blended) was visually observed, and the storage stability was evaluated, and the results are shown in Table 10. In addition, a dental material was prepared using the dental composition by the following method, and the hardness of the dental composition, the surface smoothness, hardness, and adhesive strength of the obtained dental material were evaluated, and the results are shown in Table 10. <Solubility (dispersibility)> ⊚: The composition obtained was homogeneous and transparent. ◯: The composition obtained was homogeneous and translucent. Δ: The composition obtained was cloudy and its uniformity was difficult to judge. ×: The composition obtained was not completely mixed.

[0115] <Storage stability> The active energy ray-curable dental compositions obtained in Examples 68 to 70 and the active energy ray-curable compositions obtained in Comparative Examples 27 and 28 were placed in light-shielding screw tubes, the lids were closed, and the compositions were stored under two conditions: at 40° C. for one month and at 80° C. for two weeks. The dissolution or dispersion state of the compositions after storage was confirmed to evaluate storage stability. ○: No change in condition was observed after storage at 40°C for one month and at 80°C for two weeks. △: A change in state was observed after storage under either one of the following conditions: 40°C for one month or 80°C for two weeks. ×: Changes in condition were observed after storage at 40°C for one month and at 80°C for two weeks.

[0116] <Curability> The active energy ray-curable dental compositions obtained in Examples 68 to 70 and the active energy ray-curable compositions obtained in Comparative Examples 27 and 28 were used to fill a polytetrafluoroethylene mold (20 mm × 20 mm × 10 mm) having a hole with a diameter of 6 mm in the center, and the mold was pressed with a polypropylene film and then applied with a dental light irradiator (Tokuso Power Light, manufactured by Tokuyama Dental Co., Ltd., light output density 700 mW / cm). 2 , light intensity at the irradiation surface is 640-650mW / cm 2 A light source (halogen lamp, irradiation aperture 8 mm) was placed in close contact with the polypropylene film and irradiated for 30 seconds, after which the polypropylene film was peeled off and the cured material was touched with the hand to check for stickiness and the presence or absence of uncured components. ◎: No stickiness at all (completely cured). ○: There is some stickiness, but no finger marks remain on the surface (almost completely cured, no need to wipe off uncured components). △: Sticky and finger marks remain on the surface (incomplete curing, uncured components need to be wiped off). ×: Extremely sticky, fingers stick to the surface (a large amount of uncured components remain, and the film cannot be used as a cured film).

[0117] <Surface smoothness> The surface of the cured product obtained in the above curability evaluation was visually observed to confirm smoothness and gloss. ◎: The surface is smooth and glossy. ◯: The surface is almost smooth, with slight cloudiness or slight irregularities. △: The surface is generally cloudy, and some irregularities and granularity are observed. ×: The surface is entirely cloudy and covered with granular matter.

[0118] <Hardness> The surfaces of the cured products obtained in the above curability evaluation were buffed and used to measure the Knoop hardness at a load of 10 g for 20 seconds using a Matsuzawa Seiki Microhardness Tester. The measurement temperature was 23°C. ◎: Knoop hardness is 200KHN or higher (equivalent to permanent tooth enamel). ○: Knoop hardness is 70KHN or more and less than 200KHN (equivalent to dentin). △: Knoop hardness is less than 70KHN. ×: Not cured, so measurement was not possible.

[0119] <Adhesion strength (dentin adhesion strength)> A bovine mandibular anterior tooth was polished with #1000 waterproof abrasive paper under water, a flat dentin surface for bonding was scraped off, compressed air was blown onto it for 10 seconds to dry it, and a tape with a hole of 3 mm in diameter was attached to set the adhesion surface. Then, an adhesion test piece was prepared by a known method (see the method described in JP 2010-208964 A). The adhesion test piece was immersed in 37°C water for 24 hours, and then the tensile adhesion strength was measured using an Instron universal testing machine (crosshead speed 2 mm / min), and the adhesion strength of the active energy ray-curable dental compositions obtained in Examples 1 to 10 and the active energy ray-curable compositions obtained in Comparative Examples 1 to 3 to the enamel and dentin was determined. The tensile adhesion strength value was the average value of five test pieces. ◎: The adhesive strength of both enamel and dentin is 20Mpa or more. ○: The adhesive strength between enamel and dentin is 20Mpa or more at least in one of the two locations. △: The adhesive strength of both enamel and dentin is 7Mpa or more. ×: The adhesive strength between enamel and dentin is less than 7 MPa.

[0120] [Table 10]

[0121] As is clear from the results in Table 10, the active energy ray-curable dental compositions of the Examples have high solubility (or dispersibility), curability, and storage stability, and the cured products obtained by curing them exhibit good hardness, and also have surface smoothness and adhesive strength. In particular, the cured products obtained from the active energy ray-curable dental compositions of the present invention have a low content of low molecular weight components, and therefore have excellent safety results. On the other hand, the compositions of the Comparative Examples have low solubility, curability, and storage stability, and do not undergo sufficient curing, so that the hardness and surface smoothness of the obtained cured products are low, and the adhesive strength is insufficient. Furthermore, the safety of the cured products is low because a large amount of low molecular weight components such as uncured components or decomposition products generated by ultraviolet irradiation remained in the cured products.

[0122] As shown in the evaluation results of each of the above-mentioned Examples and Comparative Examples, the active energy ray curable composition containing the polymerizable photoinitiator (A) having a specific structure according to the present invention and the polymerizable compound (B) exhibits good curability due to the high initiation efficiency of A and the absence of by-production of low molecular weight components, and can be completely cured even with long wavelength light from a UV-LED lamp having a wavelength of 365 nm to 405 nm, which does not contain short wavelength ultraviolet rays such as UV-B and UV-C. In addition, the compatibility between the polymerizable photoinitiator (A) and the polymerizable compound (B) is good, and a highly transparent curable composition and cured product applicable to the optical field can be obtained. It is clear that the content of components having a molecular weight of less than 1000 in the obtained cured product can be reduced to less than 10%, and the composition has low odor, high safety, and excellent water resistance and durability. On the other hand, the curable composition not containing the polymerizable photoinitiator (A) or the polymerizable compound (B) did not exhibit sufficient curability, and in particular, the curability against long wavelength light from a UV-LED lamp having a wavelength of 365 nm to 405 nm was low. Furthermore, it is clear that a large amount of low molecular weight components remain in the obtained cured product, and the product is poor in safety and durability, with problems such as odor generation, bleed-out over time, coloration, etc. In other words, it can be confirmed that the properties of the active energy ray-curable composition of the present invention and the cured product obtained therefrom are due to the interaction between the polymerizable photoinitiator (A) and the polymerizable compound (B) contained therein. [Industrial Applicability]

[0123] As described above, the active energy ray-curable composition of the present invention exhibits high curability and can be cured using a wide variety of light sources, from metal halide lamps to UV LED lamps with a wavelength of 405 nm. In addition, the cured product contains a small amount of low molecular weight components, and the molded products obtained by methods such as three-dimensional modeling have a low odor, are highly safe, and have high durability. The active energy ray curable composition of the present invention can be used for various applications by further combining with various additives, and can impart various physical properties such as high adhesion and adhesiveness, chemical resistance, tensile strength, elongation at break, surface hardness, durability, and self-repairing property, and can be suitably used as an active energy ray curable ink composition, an active energy ray curable inkjet ink composition, an active energy ray curable nail cosmetic composition, an active energy ray curable dental composition, an active energy ray curable pressure-sensitive adhesive composition, an active energy ray curable adhesive composition, an active energy ray curable sealant composition, an active energy ray curable coating agent composition, an active energy ray curable composition for decorative sheets, an active energy ray curable composition for self-repairing materials, an active energy ray curable elastomer composition, an active energy ray curable composition for three-dimensional modeling, an active energy ray curable vehicle coating agent composition, an active energy ray curable architectural paint composition, and the like.

Claims

1. a polymerizable photoinitiator (A) having one or more benzophenone groups and one or more ethylenically unsaturated groups per molecule; An active energy ray-curable composition comprising a polymerizable compound (B) (excluding A) having one or more ethylenically unsaturated groups per molecule, wherein the content of components having a molecular weight of less than 1,000 in a cured product of the active energy ray-curable composition is less than 5%.

2. 2. The active energy ray-curable composition according to claim 1, wherein the polymerizable photoinitiator (A) and / or the polymerizable compound (B) has one or more covalent bonds between a hetero atom and a hydrogen atom per molecule.

3. 3. The active energy ray-curable composition according to claim 1 or 2, wherein the polymerizable photoinitiator (A) and / or the polymerizable compound (B) has, as the ethylenically unsaturated group, one or more groups selected from a (meth)acrylamide group, a (meth)acrylate group, a vinyl group, a vinyl ether group, an alkyl vinyl ether group, an allyl group, a (meth)allyl ether group, a styryl group, and a maleimide group.

4. The active energy ray-curable composition according to any one of claims 1 to 3, wherein the polymerizable photoinitiator (A) and / or the polymerizable compound (B) forms a covalent bond with a hydrogen atom using one or more atoms selected from oxygen, sulfur, nitrogen, phosphorus, boron, and silicon as hetero atoms.

5. The active energy ray-curable composition according to any one of claims 1 to 4, characterized in that the polymerizable photoinitiator (A) has a (meth)acrylamide group as the ethylenically unsaturated group, and has a urethane bond and / or urea bond as the covalent bond between a hetero atom and a hydrogen atom.

6. An actinic ray-curable ink composition comprising the actinic ray-curable composition according to any one of claims 1 to 5.

7. An actinic ray-curable inkjet ink composition comprising the actinic ray-curable composition according to any one of claims 1 to 5.

8. An active energy ray-curable ink composition for two-dimensional or three-dimensional modeling, comprising the active energy ray-curable composition according to any one of claims 1 to 5.

9. An active energy ray-curable nail cosmetic composition comprising the active energy ray-curable composition according to any one of claims 1 to 5.

10. An active energy ray-curable pressure-sensitive adhesive composition comprising the active energy ray-curable composition according to any one of claims 1 to 5.

11. An active energy ray-curable adhesive composition comprising the active energy ray-curable composition according to any one of claims 1 to 5.

12. An active energy ray-curable sealing material composition comprising the active energy ray-curable composition according to any one of claims 1 to 5.

13. An active energy ray-curable coating composition comprising the active energy ray-curable composition according to any one of claims 1 to 5.

14. An active energy ray-curable self-repairing coating material comprising the active energy ray-curable composition according to any one of claims 1 to 5.

15. An active energy ray-curable dental composition comprising the active energy ray-curable composition according to any one of claims 1 to 5.