JP4859998B2 - Active energy ray-curable composition and use thereof - Google Patents

Description

  The present invention relates to an active energy ray-curable composition. More specifically, the present invention relates to an active energy ray-curable composition that is useful for forming a cured product having a low viscosity and a high refractive index and excellent adhesion to a substrate. The present invention relates to a composition and a cured product thereof, and further uses such as a lens forming agent, a coating agent, an adhesive, and an encapsulant comprising the active energy ray-curable composition.

  In recent years, with the development of light-related industries such as displays, optical communications, solar cells, and lighting, a transparent resin having excellent optical performance such as refractive index is required. Among them, there is a strong demand for lens forming materials, coating agents, optical adhesives, and sealants. For example, in an optical film used for a liquid crystal display, a fine lens is formed on a substrate for the purpose of increasing brightness. There is a demand for a lens forming material for forming, a coating agent for forming a coating layer for preventing reflection and interference fringes, and the like.

  Regarding the lens forming material, a material that can be applied to a fine molding process such as 2P molding or nanoimprint, which has been remarkably developed in recent years, is desired. Further, in solid-state lighting using light emitting diodes, a high refractive index sealing agent for increasing the brightness is desired.

  Under such circumstances, for transparent resins used in the optical field such as lens forming materials, both high refractive index and fast curability must be satisfied in order to cope with diversification of optical functions and improvement of productivity. Is required. Patent Document 1 (Japanese Patent Application Laid-Open No. 61-072748) discloses a (meth) acrylic material that is excellent in curability upon irradiation with active energy rays and that can be obtained as a (meth) acrylic material that is hard and is hard to be damaged. (Meth) acrylate compounds in which aromatic rings and sulfur atoms are introduced have been proposed.

  Furthermore, in applications of coating agents, adhesives and sealants, it is necessary to have excellent adhesion to various plastic films, glass, metals and the like. In Patent Document 2 (Japanese Patent Laid-Open No. 2006-291148) and Patent Document 3 (Japanese Patent Laid-Open No. 2008-297293), a urethane (meth) acrylate having a urethane bond in addition to an aromatic ring and a sulfur atom in the molecule. Series compounds have been proposed.

JP 61-072748 A JP 2006-291148 A JP 2008-297293 A

  However, although the (meth) acrylate compound disclosed in Patent Document 1 has a high refractive index, there is no structural unit for improving adhesion such as a urethane group in the molecular structure. When used as an adhesive or sealant, the adhesiveness to the substrate is poor.

  In the case of the urethane (meth) acrylate compound disclosed in Patent Document 2, it is very difficult to produce a single compound. For this reason, when the synthesized urethane (meth) acrylate compound is used without fractional distillation, the refractive index of the compound (composition) varies due to variations in the molecular weight of the urethane (meth) acrylate compound. The refractive index of the resulting cured product is likely to vary, which may cause variations in the quality of the final product.

  Since the urethane (meth) acrylate disclosed in Patent Document 3 is a high-viscosity liquid, when used as an adhesive or a coating agent, the handleability is not good. In the example of Patent Document 3, a coating agent diluted with ethyl acetate (paragraph number 0074) as a solvent is disclosed. However, since there are many cases where a solvent cannot be used in the above-described fine molding process such as 2P molding or nanoimprint, it is difficult to use a composition diluted with a solvent for a lens forming material.

  It is conceivable to lower the composition viscosity by blending other ethylenically unsaturated monomers as dilution monomers in addition to the solvent. Even in Patent Document 3, no example exists, but other copolymerization monomers are listed in paragraphs 0050-0053. However, it is very difficult to maintain a high refractive index even if the copolymerization monomer can be used as a monomer for dilution to reduce the viscosity and improve the handleability.

  In the present invention, under such a background, it is possible to form a cured product that is a low-viscosity composition suitable for handling properties and that has a high refractive index and excellent adhesion without being diluted with a solvent. An object is to provide an active energy ray-curable composition.

  In view of the circumstances as described above, the present inventors have studied various urethane (meth) acrylate compounds and monofunctional (meth) acrylate compounds as ethylenically unsaturated monomers, resulting in low viscosity as a composition. Found a combination of a urethane (meth) acrylate compound and a monofunctional (meth) acrylate compound, which can form a cured product with high refractive index and excellent adhesion to a substrate. Was completed.

That is, the gist of the present invention relates to an active energy curable composition comprising the following component (A) and component (B).
Component (A) is a urethane (meth) acrylate compound represented by the following general formula (1) and / or (2).

式（１）において、Ｒ_１、Ｒ_２は水素又はメチル基、Ｒ_３、Ｒ_４は炭素数１〜３の炭化水素基、Ｘは塩素、臭素、又はヨウ素、ａとｂは同じでも異なってもよい０〜４の整数、Ｙは酸素又は硫黄である。

In Formula (1), R ₁ and R ₂ are hydrogen or a methyl group, R ₃ and R ₄ are hydrocarbon groups having 1 to 3 carbon atoms, X is chlorine, bromine, or iodine, and a and b are the same or different. An integer of 0 to 4, Y is oxygen or sulfur.

In the formula (2), R ₅ and R ₆ are hydrogen or a methyl group, R ₇ and R ₈ are hydrocarbon groups having 1 to 3 carbon atoms, Z is chlorine, bromine, or iodine, c is an integer of 0 to 4, W is oxygen or sulfur.

Component (B) is a monofunctional (meth) acrylate compound represented by the following general formula (3) and / or (4).

In Formula (3), R ₉ is hydrogen or a methyl group, and R ₁₀ is a hydrocarbon group having 1 to 3 carbon atoms.
In the formula _{(4), R 11} hydrogen or a methyl _{group, R 12} is a hydrocarbon group having 1 to 3 carbon atoms.

  Furthermore, the present invention also provides a lens forming agent, a coating agent, an adhesive, and a light-emitting diode encapsulant comprising such an active energy ray-curable composition.

  The active energy ray-curable composition of the present invention has a low viscosity and very excellent handleability without containing a solvent, and the cured product obtained by irradiation with active energy rays has a high refractive index and Excellent adhesion to the substrate.

The present invention is described in detail below.
In the present invention, the urethane (meth) acrylate compound used as the component (A) can be produced by the production method exemplified in JP-A-2008-297293 (Patent Document 3). That is, it is as follows.

  The urethane (meth) acrylate compound of component (A) used in the present invention is represented by the above general formula (1) and / or (2), and has an aromatic ring, sulfur atom, and necessary in the molecular structure. Depending on the case, it has halogen atoms such as chlorine, bromine and iodine. These atoms and atomic groups improve the refractive index of the compound and the cured product after polymerization.

  The urethane (meth) acrylate compound of the present invention can be obtained by reacting a compound represented by the following general formula (5) or (6) with an isocyanatoalkyl (meth) acrylate.

In Formula (5), R ₃ is a hydrocarbon group having 1 to ₃ carbon atoms, X is chlorine, bromine, or iodine, a and b may be the same or different, and an integer of 0 to 4, Y is oxygen or sulfur is there.

In Formula (6), R ₇ is a hydrocarbon group having 1 to 3 carbon atoms, Z is chlorine, bromine, or iodine, c is an integer of 0 to 4, and W is oxygen or sulfur.

  Examples of the compound represented by the above formula (5) include 4,4′-bis [β-hydroxymethylthio] diphenylsulfone, 4,4′-bis [β-hydroxyethylthio] diphenylsulfone, 4,4′- Bis [β-hydroxypropylthio] diphenylsulfone, 4,4′-bis [β-hydroxyethylthio] -3,3 ′, 5,5′-tetrachlorodiphenylsulfone, 4,4′-bis [β-hydroxy Diol compounds such as ethylthio] -3,3 ′, 5,5′-tetrabromodiphenylsulfone; 4,4′-bis [β-mercaptomethylthio] diphenylsulfone, 4,4′-bis [β-mercaptoethylthio Diphenylsulfone, 4,4′-bis [β-mercaptopropylthio] diphenylsulfone, 4,4′-bis [β-mercaptoethylthio] Dithiol compounds such as −3,3 ′, 5,5′-tetrachlorodiphenylsulfone, 4,4′-bis [β-mercaptoethylthio] -3,3 ′, 5,5′-tetrabromodiphenylsulfone, etc. Can be mentioned.

  Among these, a diol compound is preferable from the viewpoint of odor, a non-halogen compound is more preferable from an environmental viewpoint, and particularly preferably from the viewpoint of the viscosity of the obtained urethane (meth) acrylate compound, the following formula (7) 4,4′-bis [β-hydroxyethylthio] diphenylsulfone having a chemical structure.

  Examples of the compound represented by the above formula (6) include a diol compound and a dithiol compound. Examples of the compound belonging to the diol compound include hydroxymethylthio-p-xylylene, hydroxymethylthio-m-xylylene, and hydroxymethylthio-o-. Xylylene, β-hydroxyethylthio-p-xylylene, β-hydroxyethylthio-m-xylylene, β-hydroxyethylthio-o-xylylene, 3-hydroxypropylthio-p-xylylene, 3-hydroxypropylthio-m- Xylylene, 3-hydroxypropylthio-o-xylylene, 1,4-bis [hydroxymethylthiomethyl] -monochlorobenzene, 1,4-bis [hydroxymethylthiomethyl] -dichlorobenzene, 1,4-bis [hydroxymethylthiomethyl] − Lichlorobenzene, 1,4-bis [hydroxymethylthiomethyl] -2,3,5,6-tetrachlorobenzene, 1,3-bis [hydroxymethylthiomethyl] -2,4,5,6-tetrachlorobenzene, 1,2 -Bis [hydroxymethylthiomethyl] -3,4,5,6-tetrachlorobenzene, 1,4-bis [β-hydroxyethylthiomethyl] -2,3,5,6-tetrachlorobenzene, 1,3-bis [ β-hydroxyethylthiomethyl] -2,4,5,6-tetrachlorobenzene, 1,2-bis [β-hydroxyethylthiomethyl] -3,4,5,6-tetrachlorobenzene, 1,4-bis [ 3-hydroxypropylthiomethyl] -2,3,5,6-tetrachlorobenzene, 1,3-bis [3-hydroxypropylthiomethyl] -2,4 5,6-tetrachlorobenzene, 1,2-bis [3-hydroxypropylthiomethyl] -3,4,5,6-tetrachlorobenzene, 1,4-bis [hydroxymethylthiomethyl] -2,3,5,6 -Tetrabromobenzene, 1,3-bis [hydroxymethylthiomethyl] -2,4,5,6-tetrabromobenzene, 1,2-bis [hydroxymethylthiomethyl] -3,4,5,6-tetrabromobenzene 1,4-bis [β-hydroxyethylthiomethyl] -2,3,5,6-tetrabromobenzene, 1,3-bis [β-hydroxyethylthiomethyl] -2,4,5,6-tetra Bromobenzene, 1,2-bis [β-hydroxyethylthiomethyl] -3,4,5,6-tetrabromobenzene, 1,4-bis [3-hydroxypropylthiomethyl ] -2,3,5,6-tetrabromobenzene, 1,3-bis [3-hydroxypropylthiomethyl] -2,4,5,6-tetrabromobenzene, 1,2-bis [3-hydroxypropyl] Thiomethyl] -3,4,5,6-tetrabromobenzene and the like.

  Among the compounds represented by the above formula (6), examples of the compound belonging to the dithiol compound include mercaptomethylthio-p-xylylene, mercaptomethylthio-m-xylylene, mercaptomethylthio-o-xylylene, β-mercaptoethylthio- p-xylylene, β-mercaptoethylthio-m-xylylene, β-mercaptoethylthio-o-xylylene, 3-mercaptopropylthio-p-xylylene, 3-mercaptopropylthio-m-xylylene, 3-mercaptopropylthio- o-xylylene, 1,4-bis [mercaptomethylthiomethyl] -monochlorobenzene, 1,4-bis [mercaptomethylthiomethyl] -dichlorobenzene, 1,4-bis [mercaptomethylthiomethyl] -trichlorobenzene, 1,4- Bis [mercapto Tylthiomethyl] -2,3,5,6-tetrachlorobenzene, 1,3-bis [mercaptomethylthiomethyl] -2,4,5,6-tetrachlorobenzene, 1,2-bis [mercaptomethylthiomethyl] -3,4 , 5,6-tetrachlorobenzene, 1,4-bis [β-mercaptoethylthiomethyl] -2,3,5,6-tetrachlorobenzene, 1,3-bis [β-mercaptoethylthiomethyl] -2,4 , 5,6-tetrachlorobenzene, 1,2-bis [β-mercaptoethylthiomethyl] -3,4,5,6-tetrachlorobenzene, 1,4-bis [3-mercaptopropylthiomethyl] -2,3 , 5,6-tetrachlorobenzene, 1,3-bis [3-mercaptopropylthiomethyl] -2,4,5,6-tetrachlorobenzene, 1,2-bis 3-mercaptopropylthiomethyl] -3,4,5,6-tetrachlorobenzene, 1,4-bis [mercaptomethylthiomethyl] -2,3,5,6-tetrabromobenzene, 1,3-bis [mercaptomethylthio Methyl] -2,4,5,6-tetrabromobenzene, 1,2-bis [mercaptomethylthiomethyl] -3,4,5,6-tetrabromobenzene, 1,4-bis [β-mercaptoethylthiomethyl] ] -2,3,5,6-tetrabromobenzene, 1,3-bis [β-mercaptoethylthiomethyl] -2,4,5,6-tetrabromobenzene, 1,2-bis [β-mercaptoethyl] Thiomethyl] -3,4,5,6-tetrabromobenzene, 1,4-bis [3-mercaptopropylthiomethyl] -2,3,5,6-tetrabromobenzene, 1 , 3-bis [3-mercaptopropylthiomethyl] -2,4,5,6-tetrabromobenzene, 1,2-bis [3-mercaptopropylthiomethyl] -3,4,5,6-tetrabromobenzene Etc.

  Among these, a diol compound is preferable from the viewpoint of odor, a non-halogen compound is more preferable from an environmental viewpoint, and particularly preferably, from the viewpoint of the viscosity of the obtained urethane (meth) acrylate compound, the following formula (8) Β-hydroxyethylthio-p-xylylene having a chemical structure.

  Specific examples of the isocyanatoalkyl (meth) acrylate include, for example, isocyanatomethyl (meth) acrylate, 2-isocyanatoethyl (meth) acrylate, 2-isocyanatopropyl (meth) acrylate, 3-isocyanatopropyl (meth) ) Aliphatic isocyanatoalkyl (meth) acrylates such as acrylate.

  Among these, 2-isocyanatoethyl (meth) acrylate is preferable from the viewpoint of availability, and 2-isocyanatoethyl acrylate is particularly preferable from the viewpoint of quick curing of the obtained urethane (meth) acrylate compound. .

  The charge ratio in the reaction of the compound represented by the above formula (5) or (6) and the isocyanatoalkyl (meth) acrylate is adjusted to 1 mol of the compound represented by the above formula (5) or (6). It is preferable that it is 2-2.1 mol of alkyl (meth) acrylates. If the amount is too small, the hydroxyl-terminated or mercapto-group-terminated compound remains in the reaction system after the reaction, so that the desired urethane (meth) acrylate compound tends to be not obtained in a good yield. Since the raw material isocyanatoalkyl (meth) acrylate remains in the reaction system later, the target urethane (meth) acrylate compound tends not to be obtained in good yield.

  In the present invention, a reaction method in which the compound represented by the above formula (5) or (6) is dissolved in an organic solvent and this solution is dropped into an isocyanatoalkyl (meth) acrylate is preferable. Examples of the organic solvent used include aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate and butyl acetate, aliphatic alcohols such as n-propyl alcohol and iso-propyl alcohol, acetone, and methyl ethyl ketone. And ketones such as cyclohexanone and ethers such as tetrahydrofuran and diethyl ether. Of these, tetrahydrofuran is particularly preferred from the viewpoint of solubility.

  The concentration of the compound represented by the above formula (5) or (6) in the solution is preferably 1 to 500 parts by weight / L, more preferably 10 to 300 parts by weight / L, and still more preferably 50 to 200 parts by weight / L. L. A preferable range of the dropping rate is preferably 1 to 100 mol / hour, more preferably 5 to 100 mol / hour, still more preferably when the total amount of the compound represented by the above formula (5) or (6) is 100 mol. Is 10 to 100 mol / hour. If the dropping speed is too slow, the productivity tends to be inferior, and if it is too fast, the reaction runs away, and the isocyanatoalkyl (meth) acrylate as a raw material tends to be polymerized due to the heat generation.

  In the present invention, it is preferable to use a metal catalyst such as dibutyltin dilaurate or an amine catalyst such as 1,8-diazabicyclo [5.4.0] undecene-7 for the purpose of promoting the reaction. The amount of the catalyst added is preferably 0.01 parts by weight or more, particularly 0.01 to 0.1 parts by weight, with respect to 100 parts by weight of the compound represented by the above formula (5) or (6). Furthermore, it is preferable that it is 0.02-0.05 weight part. If the amount added is too small, the productivity tends to be inferior.

  The reaction temperature is usually in the range of 40 to 80 ° C, preferably 50 to 70 ° C, more preferably 55 to 65 ° C. If the reaction temperature is too low, the productivity tends to be inferior. If the reaction temperature is too high, the raw material isocyanatoalkyl (meth) acrylate tends to be polymerized.

The reaction is preferably performed under an inert gas in order to improve the hue of the product.
The end point of the reaction can be judged by confirming the amount of isocyanate in the reaction solution by a technique such as titration. Examples of the titration method include collecting a part of the reaction product, adding it to di-n-butylamine, causing the reaction, and back titrating the remaining di-n-butylamine with hydrochloric acid.

The obtained urethane (meth) acrylate-based compound may be washed to remove a trace amount of raw material isocyanatoalkyl (meth) acrylate and the like. As a washing method, a poor solvent of the compound of the general formula (1) or (2) is introduced into the reaction system, and isocyanatoalkyl (meth) acrylate transferred to the poor solvent layer is removed. As the poor solvent, lower alcohols such as methanol and ethanol, and mixed solvents thereof are preferable.
Thus, the urethane (meth) acrylate compound (A) used in the present invention is obtained.

  Since the urethane (meth) acrylate compound (A) used in the present invention has (meth) acryloyl groups at both ends of the molecular structure, it is rapidly cured by active energy rays such as ultraviolet rays and has a highly crosslinked structure. Form a cured product. This fast curability is important in coating applications and can be sufficiently cured with a small amount of light.

  Further, since the urethane (meth) acrylate compound (A) has a urethane bond in the molecular structure, the formed coating layer has high adhesion to a substrate such as a plastic film, glass or metal. It will have. Further, as shown in the above-described production method, since it is produced by a relatively simple reaction, oligomer bodies and impurities are extremely small, and the refractive index accuracy is excellent.

The refractive index accuracy of the urethane (meth) acrylate compound in the present invention is preferably within ± 0.001, more preferably within ± 0.0005, and particularly preferably within ± 0.0003. If the accuracy exceeds the above range, optical design of the coat layer tends to be difficult.
In the present invention, among the urethane (meth) acrylate compounds (A), the compound represented by the general formula (1) is preferable from the viewpoint of high refractive index.

  In the present invention, the monofunctional (meth) acrylate compound used as the component (B) is represented by the general formula (3) and / or (4), and specific examples thereof include, for example, 2- (O-phenylphenoxy) methyl acrylate, 2- (m-phenylphenoxy) methyl acrylate, 2- (p-phenylphenoxy) methyl acrylate, 2- (o-phenylphenoxy) ethyl acrylate, 2- (m-phenylphenoxy) General formulas such as ethyl acrylate, 2- (p-phenylphenoxy) ethyl acrylate, 2- (o-phenylphenoxy) propyl acrylate, 2- (m-phenylphenoxy) propyl acrylate, 2- (p-phenylphenoxy) propyl acrylate A biphenyl compound represented by (3); 2- Enyl-2 ′-(β- (meth) acryloyloxymethoxyphenyl) propane, 2-phenyl-2 ′-(β- (meth) acryloyloxyethoxyphenyl) propane, 2-phenyl-2 ′-(β- (meta And bisphenol A compounds represented by the general formula (4) such as acryloyloxypropoxyphenyl) propane. Among these, from the viewpoint of high refractive index, the biphenyl compound represented by the general formula (3) is preferable, from the viewpoint of fast curing, acrylate is more preferable, and from the viewpoint of low viscosity, 2- (o-phenylphenoxy). ) Ethyl acrylate is particularly preferred.

  In the present invention, the compounding amount of the component (B) is 10 to 90 parts by weight, more preferably 20 to 80 parts by weight, still more preferably 30 to 30 parts by weight based on 100 parts by weight of the total of the components (A) and (B). 70 parts by weight, particularly preferably 40 to 60 parts by weight. If the amount of the component (B) is too small, it tends to be difficult to lower the viscosity of the active energy ray-curable composition, and conversely if too large, the rapid curability due to the active energy rays is reduced, and There exists a tendency for the adhesiveness with a material to fall.

In addition, as a light quantity required for hardening, when performing hardening by an ultraviolet-ray, for example, 0.1-20 J / cm < ² > is preferable and 0.5-10 J / cm < ² > is more preferable.

  The urethane (meth) acrylate compound used in the present invention has a high refractive index because it has an aromatic ring, a sulfur atom and, if necessary, a halogen atom such as chlorine, bromine and iodine in the molecular structure. Since the monofunctional (meth) acrylate compound used in the invention also has an aromatic ring in the molecular structure and a high refractive index, the active energy ray-curable composition of the present invention is a cured product having a high refractive index. Can be formed.

In the present invention, the refractive index of the cured product is important, and the refractive index of the cured product is preferably 1.58 or more, more preferably 1.58 to 1.64, and even more preferably 1.59 to 1. .63, particularly 1.60 to 1.62. If the refractive index of the cured product is too low, it becomes difficult to meet the recent demand for higher refractive index, and if it is too high, the Abbe number tends to decrease.
In addition, the refractive index in this invention is a value measured at 23 degreeC using a NaD line | wire.

  In the present invention, the Abbe number is also important, preferably 25 or more, more preferably 25 to 40, still more preferably 26 to 35, and particularly preferably 26 to 30. A decrease in Abbe number means an increase in chromatic dispersion. If the Abbe number is too low, color unevenness tends to occur in the lens and the coating film. In general, the improvement of the Abbe number causes a decrease in the refractive index. Therefore, it is necessary to appropriately select the type and blending amount of the component (B). For example, as the component (B), a bisphenol A compound is selected from among the above, or the blending amount is 10 parts by weight or more based on the total of 100 parts by weight of the components (A) and (B). Etc. are selected. In general, the upper limit of the Abbe number is 100.

  In the present invention, the monofunctional (meth) acrylate compound (B) used has a low viscosity of 1 Pa · s or less near room temperature, and is blended into a highly viscous urethane (meth) acrylate compound to reduce the viscosity. A viscous composition can be prepared.

  Here, it is known to blend a low-viscosity monofunctional (meth) acrylate compound with a high-viscosity urethane (meth) acrylate compound. In the present invention, as the monofunctional (meth) acrylate compound capable of achieving a low viscosity without decreasing the Abbe number while maintaining a high level of refractive index, the specific formula (3) is used. And / or has the greatest feature in selecting the compound represented by (4). For example, the active energy ray-curable composition containing the monofunctional (meth) acrylate compound described in Paragraph Nos. 0050 and 0051 of Patent Document 3 cannot obtain the effect of the present invention.

  In the present invention, the viscosity of the active energy ray-curable composition is important, and the viscosity at 25 ° C. is preferably 100 Pa · s or less, more preferably 1 to 90 Pa · s, and further preferably 2 to 80 Pa · s. It is preferably s, particularly 3 to 70 Pa · s. If the viscosity is too high, it will be difficult to coat without solvent, and if it is too low, it will be difficult to apply to a fine lens manufacturing process such as 2P molding or nanoimprint.

  The active energy ray-curable composition of the present invention contains the component (A) and the component (B), and preferably further contains a photopolymerization initiator as the component (C).

  Such a photopolymerization initiator may be any one that generates radicals by the action of light. For example, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl -1-phenylpropan-1-one, 1- (4-isopropylenephenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropane -1-one, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2- Morpholinopropane-1, benzoin, benzoin methyl ether, benzoin ethyl ether Benzoin isopropyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3'-dimethyl -4-methoxybenzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, camphorquinone, dibenzosuberone, 2-ethylanthraquinone, 4 ' , 4 ″ -diethylisophthalophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, α-acyloxime ester, acylphosphine oxide , Methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, among others, benzyldimethyl ketal, 1- Hydroxycyclohexyl phenyl ketone, benzoyl isopropyl ether, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, and 2-hydroxy-2-methyl-1-phenylpropan-1-one are preferably used. It is done.

  The content of the component (C) is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, with respect to 100 parts by weight of the total of the component (A) and the component (B). Particularly preferred is 0.3 to 3 parts by weight. If the content is too small, the curing rate tends to be slow, and if it is too large, the hue of the cured product tends to deteriorate.

  Further, as an auxiliary of the photopolymerization initiator, for example, triethanolamine, triisopropanolamine, 4,4′-dimethylaminobenzophenone (Michler ketone), 4,4′-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, Ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone, 2, 4-diisopropylthioxanthone or the like can be used in combination.

  In the present invention, it is also possible to contain a mercaptan compound as a chain transfer agent in addition to the component (C).

  As the mercaptan compound, a compound having a plurality of thiol groups in the molecular structure is preferable. By using a compound having a plurality of thiol groups, it is possible to further increase the refractive index and improve the surface hardness.

  Examples of mercaptan compounds having a plurality of thiol groups include benzenedithiol, xylylenedithiol, hexanedithiol, tolylenetrithiol, pentaerythritol tetrakis (β-thiopropionate), pentaerythritol tetrakis (thioglycolate), tri Methylolpropane tris (β-thiopropionate), trimethylolpropane tris (thioglycolate), diethylene glycol bis (β-thiopropionate), diethylene glycol bis (thioglycolate), triethylene glycol bis (β-thiopro) Pionate), triethylene glycol bis (thioglycolate), dipentaerythritol hexakis (β-thiopropionate), dipentaerythritol hexakis (thioglycolate) ), Tris [2- (β-thiopropionyloxy) ethyl] triisocyanurate, tris (2-thioglyconyloxyethyl) triisocyanurate, tris [2- (β-thiopropionyloxyethoxy) ethyl] triisocyanurate , Tris (2-thioglyconyloxyethoxyethyl) triisocyanurate, tris [3- (β-thiopropionyloxy) propyl] triisocyanurate, tris (3-thioglyconyloxypropyl) triisocyanurate, and the like. .

  In addition, the active energy ray-curable composition of the present invention may use other copolymerizable components and various additives as long as they do not impair the effects of the present invention.

  As another copolymerization component, for example, an ethylenically unsaturated monomer (however, component (A) and component (B) are excluded) is preferable. Such an ethylenically unsaturated monomer may be any monomer having one or more ethylenically unsaturated groups in one molecule, and is a monofunctional monomer (excluding component (B)), bifunctional monomer (provided that , Component (A) is excluded.) And trifunctional or higher monomers.

  Examples of the monofunctional monomer include styrene, vinyl toluene, chlorostyrene, α-methyl styrene, methyl (meth) acrylate, ethyl (meth) acrylate, acrylonitrile, vinyl acetate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxy. Propyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3- Chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, glycidyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, isoborni (Meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl ( (Meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, n-stearyl (meth) acrylate, benzyl (meth) acrylate, phenol ethylene oxide modified (meth) acrylate, nonylphenol propylene oxide modified ( Half ester (meth) acrylates of phthalic acid derivatives such as (meth) acrylate and 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, furfuryl (meth) acrylate Relate, carbitol (meth) acrylate, benzyl (meth) acrylate, butoxyethyl (meth) acrylate, allyl (meth) acrylate, acryloylmorpholine, 2-hydroxyethylacrylamide, N-methylol (meth) acrylamide, N-vinylpyrrolidone , 2-vinylpyridine, 2- (meth) acryloyloxyethyl acid phosphate monoester, and the like.

  In addition to the above, as a monofunctional monomer, there may also be mentioned a Michael adduct of acrylic acid or 2-acryloyloxyethyl dicarboxylic acid monoester. Examples of the Michael adduct of acrylic acid include acrylic acid dimer, methacrylic acid dimer, acrylic acid. Examples include trimers, methacrylic acid trimers, acrylic acid tetramers, and methacrylic acid tetramers. Examples of 2-acryloyloxyethyl dicarboxylic acid monoester which is a carboxylic acid having a specific substituent include 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, and 2-acryloyloxyethyl. Examples include phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, and 2-methacryloyloxyethyl hexahydrophthalic acid monoester. Furthermore, oligoester acrylate is also mentioned.

  Examples of the bifunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and dipropylene. Glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide modified bisphenol A type di (meth) acrylate, propylene oxide modified bisphenol A type Di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,6-hexanediol ethylene oxide modified di ( Acrylate), glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, diglycidyl phthalate di (meth) acrylate Hydroxypivalic acid-modified neopentyl glycol di (meth) acrylate, isocyanuric acid ethylene oxide-modified diacrylate, 2- (meth) acryloyloxyethyl acid phosphate diester, and the like.

Examples of the tri- or higher functional monomer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth). ) Acrylate, tri (meth) acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly (meth) acrylate, isocyanuric acid ethylene oxide modified triacrylate, ethylene oxide modified dipentaerythritol penta (meth) acrylate, ethylene oxide modified dipentaerythritol Hexa (meth) acrylate, ethylene oxide modified pentaerythritol tri (meth) acrylate, Chi alkylene oxide modified pentaerythritol tetra (meth) acrylate, and succinic acid-modified pentaerythritol tri (meth) acrylate.
Said ethylenically unsaturated monomer may be used independently and may use 2 or more types together.

  The content of the ethylenically unsaturated monomer is preferably 30 parts by weight or less and more preferably 10 parts by weight or less with respect to 100 parts by weight as a total of the component (A) and the component (B). If the amount is too large, the refractive index tends to decrease.

  Various additives include silane coupling agents, antioxidants, polymerization inhibitors, yellowing inhibitors, ultraviolet absorbers, fillers, dyes and pigments, oils, plasticizers, waxes, desiccants, dispersants, wetting agents. Agents, emulsifiers, gelling agents, stabilizers, antifoaming agents, leveling agents, thixotropy imparting agents, flame retardants, fillers, reinforcing agents, matting agents, crosslinking agents and the like.

  Thus, the active energy ray-curable composition of the present invention has a low viscosity without using a solvent, and can form a cured product having a high refractive index that is excellent in adhesion to a substrate, thereby forming a lens. It is suitably used as a material, coating agent, adhesive and sealant.

  When the active energy ray-curable composition of the present invention is used as a lens-forming material, the method for forming a lens is not particularly limited, and known methods such as cast molding and 2P molding are used. The lens here is not limited as long as it refractions, diffracts, and interferes with light such as a prism lens, a Fresnel lens, and a microlens array, and a prism-like lens is formed on a substrate such as a resin film or glass. A lens film or the like in which minute irregularities are periodically or randomly formed is also a suitable use example. In particular, as a suitable use example of the present invention, a high brightness film can be mentioned. The high brightness film is a 100 μm size prism arrayed on a resin film, and has the function of condensing diffused light from the light source and emitting it to the front to improve display brightness and power consumption. It is an optical film.

  In order to produce a high brightness film by 2P molding, first, the active energy ray-curable composition is cast on a matrix whose surface is processed into a fine prism shape, and a transparent resin film is placed on top of the composition. After that, the composition is cured by irradiating active energy rays from the upper part of the resin film, and the cured product having the prism shape is peeled from the matrix together with the resin film. As the mother mold, a mold, a glass mold, a resin mold, or the like can be used. Examples of the resin film include a polyolefin film, a polyester film, a polycarbonate film, and an acrylic film.

  As active energy rays, far ultraviolet rays, ultraviolet rays, near ultraviolet rays, visible rays, infrared rays and other electromagnetic waves, X rays, γ rays and other electromagnetic waves, as well as electron beams, proton rays, neutron rays, etc. can be used. Curing by ultraviolet irradiation is advantageous because of the availability of the irradiation device and the price.

As a method of curing by ultraviolet irradiation, 0.1 to 10 J / cm using a high-pressure mercury lamp, ultra-high pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, chemical lamp, or the like that emits light in the wavelength range of 150 to 450 nm. ^What is necessary is just to irradiate about ² ultraviolet rays. After the ultraviolet irradiation, heating can be performed as necessary to complete the curing.

  When the active energy ray-curable composition of the present invention is used as a coating agent, the coating method is not particularly limited, and known methods such as spin coating, dip coating, bar coating, and gravure coating are used.

  When used as a coating agent, solvent dilution is not preferred for the purpose of the present invention, but a small amount of solvent can be added for the purpose of improving handling properties. In that case, examples of the solvent include aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate, butyl acetate and propylene glycol monomethyl ether acetate, alcohols such as n-propyl alcohol and iso-propyl alcohol, Well-known organic solvents, such as ketones, such as acetone, methyl ethyl ketone, and cyclohexanone, are mentioned.

  The amount of the organic solvent is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, and still more preferably 5 parts by weight or less with respect to 100 parts by weight of the active energy ray-curable composition. If the amount is too large, the drying load tends to increase.

  The coating agent of the present invention is cured by irradiating an active energy ray after coating this on a substrate and drying the solvent as necessary. Such a base material is not particularly limited, and examples thereof include resin films such as polyolefin film, polyester film, polycarbonate film, and acrylic film, and glass.

  As described above, the active energy ray-curable composition of the present invention has a low viscosity, can form a cured product having a high refractive index and excellent adhesion to a substrate, a lens-forming material, a coating It is useful for various applications such as adhesives, adhesives, sealants, pressure-sensitive adhesives, paints, inks, and coating binders. Especially, it is used suitably as a lens forming agent which forms microlenses, such as a Fresnel lens and a microlens array, on a base material.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded.
In the examples, “parts” and “%” mean weight basis unless otherwise specified.
The measurement conditions for each characteristic are as follows.

(1) Viscosity Using an E-type viscometer manufactured by Tokyo Keiki Co., Ltd., the viscosity was measured at 25 ° C. and a rotational speed of 5 rpm (EMD 3 ° cone).

(2) Refractive index It measured at 25 degreeC using "Abbe refractometer 1T (NaD line | wire)" by an Atago company.

(3) Abbe number It measured at 25 degreeC using "Abbe refractometer 1T" made from an Atago company.

(4) Adhesiveness According to JIS K 5600-5-6, a peel test (peeling speed 10 cm / sec) was performed, and the coating layer was peeled off from the polyethylene terephthalate (PET) substrate. ○.

[Production of urethane (meth) acrylate compound (A)]
A four-necked flask equipped with a dropping funnel, thermometer, stirrer, water-cooled condenser, and nitrogen gas blowing port was charged with 52 g (0.37 mol) of 2-isocyanatoethyl acrylate and 0.02 g of dibutyltin dilaurate. A funnel was charged with a uniform solution of 66.7 g (0.18 mol) of 4,4′-bis [β-hydroxyethylthio] diphenylsulfone and 700 g of THF (tetrahydrofuran). After raising the temperature in the flask to 60 ° C., the solution was dropped from the dropping funnel at a rate of 370 g / hour to carry out the reaction, and the reaction was terminated when the residual isocyanate group reached 0.1%. Thereafter, 0.4 g of hydroquinone methyl ether was added as a polymerization inhibitor, and the solvent was distilled off to obtain a urethane (meth) acrylate compound (A). The viscosity of the obtained urethane (meth) acrylate compound (A) was 1640 Pa · s.

Further, from the ¹³ C-NMR, ¹ H-NMR, and infrared chart of the obtained urethane (meth) acrylate compound (A), the structure of this urethane (meth) acrylate compound (A) is as follows. It was.

(Production of active energy ray-curable composition)
Urethane (meth) acrylate compound (A) obtained above and monofunctional (meth) acrylate (B) as 2- (o-phenylphenoxy) ethyl acrylate (NK ester “A-LEN-” manufactured by Shin-Nakamura Chemical Co., Ltd.) 10 "), 2-phenyl-2 '-(β- (meth) acryloyloxyethoxyphenyl) propane (NK ester" A-CMP-1E "manufactured by Shin-Nakamura Chemical Co., Ltd.), or (B) a single component that does not fall under component As a functional (meth) acrylate, 2-hydroxy-3-phenoxypropyl acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester “702A”), as a photopolymerization initiator (C), 2-hydroxy-2-methyl-1-phenyl- Propan-1-one (Ciba Specialty Chemicals, “Darocur 1173” (trade name)) is shown in Table 1 respectively. Blended amount, to prepare an active energy ray-curable composition was stirred until 1 hour uniform at room temperature. The viscosity of each composition obtained is as shown in Table 1.

[Formation of coat layer]
The active energy ray-curable composition obtained above was bar-coated on a PET film having a thickness of 100 μm (masked with a tape attached to a part of the plate surface for film thickness measurement). Using a high pressure mercury lamp 80W and a single lamp, one pass of UV irradiation (cumulative dose 1 J / cm ² ) is performed at a conveyor speed of 4.3 m / min from a height of 13 cm to form a 10 μm thick coat layer did. The refractive index and Abbe number of the obtained coating layer were measured. Moreover, adhesiveness was evaluated based on the said evaluation method. The results are shown in Table 1.

Composition No. 1-4 is an example of the present invention. 5 and 6 are comparative examples.
As a monofunctional monomer, a composition No. 1 was blended with 2- (o-phenylphenoxy) ethyl acrylate belonging to the compound represented by the general formula (3). 1-3, composition No. 4 in which 2-phenyl-2 ′-(β-((meth) acryloyloxyethoxyphenyl) propane belonging to the compound represented by the general formula (4) is blended has low viscosity. The composition was excellent in handling properties, and the obtained cured product had a high refractive index of 1.58 or more and an Abbe number of 26-30, which was a very good value. Each of the cured products obtained from .1-4 was excellent in adhesion.

  On the other hand, composition no. 6 is a blend of monofunctional (meth) acrylates exemplified in Patent Document 3. The blending amount of monofunctional (meth) acrylate is No. By making the amount the same as that of No. Although the refractive index could be lowered to the same level as that of the composition No. 4, the refractive index was 1.563. It is lower than 1-4 and is unsuitable as a material for optical use such as a lens forming agent. Therefore, only when a monofunctional (meth) acrylate having a specific structure is used (No. 1-4), viscosity reduction is achieved without impairing the high refractive index of the urethane (meth) acrylate as the component (A). I understand that I can do it.

  Composition No. 5 is a case where the monofunctional monomer for dilution is not included. Based on the urethane (meth) acrylate compound (A) represented by the general formula (1), a cured product having a refractive index increased to some extent can be obtained, but it contains neither a monofunctional monomer nor a solvent, and thus has a high viscosity. It was inferior in coating properties, and was inferior in adhesion.

The active energy ray-curable composition of the present invention can form a cured product having a low viscosity, a high refractive index and excellent adhesion to a substrate. It is useful as various film-forming materials such as lens-forming materials, coating agents, adhesives, sealants, pressure-sensitive adhesives, paints, inks, coating binders, among others, display substrates, optical films, lenses, solar cells, It is very useful for use as a coating agent for memory disks and the like. In particular, it is also suitably used as a lens forming agent for forming microlenses such as Fresnel lenses and microlens arrays on a substrate.

Claims (9)

(A) Urethane (meth) acrylate compound represented by the following general formula (1) and / or (2); and (B) Monofunctional (meth) represented by the following general formula (3) and / or (4). An active energy ray-curable composition comprising an acrylate compound.

(In formula (1), R ₁ and R ₂ are hydrogen or a methyl group, R ₃ and R ₄ are hydrocarbon groups having 1 to 3 carbon atoms, X is chlorine, bromine, or iodine, and a and b are the same or different. _May be an integer of 0 to 4, Y is oxygen or sulfur, and in the formula (2), R ₅ and R ₆ are hydrogen or a methyl group, R ₇ and R ₈ are hydrocarbon groups having 1 to 3 carbon atoms, Z is chlorine, bromine, or iodine, c is an integer of 0 to 4, W is oxygen or sulfur, and in formula (3), R ₉ is hydrogen or a methyl group, and R ₁₀ is a hydrocarbon having 1 to 3 carbon atoms. (In the formula (4), R ₁₁ hydrogen or a methyl group, R ₁₂ is a hydrocarbon group having 1 to 3 carbon atoms.) The active energy ray-curable composition according to claim 1, further comprising (C) a photopolymerization initiator. The active energy ray-curable composition according to claim 1, wherein the viscosity at 25 ° C. is 100 Pa · s or less. The refractive index of hardened | cured material becomes 1.58 or more, The active energy ray curable composition in any one of Claims 1-3 characterized by the above-mentioned. It is a hardened | cured material obtained by active energy ray irradiation of the active energy ray-curable composition in any one of Claims 1-4, Comprising: A refractive index is 1.58 or more, Hardened | cured material characterized by the above-mentioned. A lens forming agent comprising the active energy ray-curable composition according to claim 1. A coating agent comprising the active energy ray-curable composition according to any one of claims 1 to 4. An adhesive comprising the active energy ray-curable composition according to any one of claims 1 to 4. A sealant for a light-emitting diode, comprising the active energy ray-curable composition according to claim 1.