Active energy ray-curable resin composition containing compound having nitroso group and polyfunctional polyglycerin-based (METH)acrylic acid ester, and cured product thereof

Abstract

To provide a polyglycerin alkylene oxide (meth)acrylic acid ester-containing active energy ray-curable resin composition that has excellent high-temperature storage stability and storage stability over time and has substantially the same sensitivity and adhesion when the resin composition is cured before and after high-temperature long-term storage.　The problem is solved by an active energy ray-curable resin composition that contains (A) a compound having a nitroso group and (B) a polyfunctional (meth)acrylic acid ester having a polyoxyalkylene group having a polyglycerin skeleton as the main chain.

Description

[Supplementary based on Rule 26, January 15, 2026] An active energy ray-curable resin composition containing a compound having a nitroso group and a polyfunctional polyglycerol-based (meth)acrylate, and a cured product thereof

[0001] The present invention relates to an active energy ray-curable resin composition and a cured product thereof.

[0002] Semiconductor devices are indispensable in modern society and have an impact on all industrial fields. In order to realize "Moore's Law", which has been a guiding principle for the technological evolution of semiconductors, all companies have been diligently pouring their efforts into development. As semiconductor integrated circuits are advancing in high functionality through miniaturization, high integration, high speed, and large scale, material development associated with this is being actively carried out.

[0003] For miniaturization, materials that can achieve high sensitivity, high adhesion, and high resolution are required. Candidates for such materials include photocrosslinkable compounds containing multiple reactive groups (trifunctional or more), and examples thereof include radically polymerizable compounds such as (meth)acrylate-based monomers, urethane (meth)acrylate monomers / oligomers, epoxy (meth)acrylate oligomers, and polyester (meth)acrylate oligomers. Since such photocrosslinkable compounds contain multiple reactive groups, they have poor stability during high-temperature storage over time and have problems in maintaining the performance of sensitivity, adhesion, hardness, and resolution.

[0004] In Patent Document 1, compounds having an ethylenically unsaturated double bond with three or more functional groups are exemplified for improving transmittance, sensitivity to exposure, adhesion to a substrate, and mechanical strength. In Patent Document 2, a photopolymerizable polyfunctional monomer having an ethylenically unsaturated group with three or more functional groups, which is a multi-branched oligomer or polymer, has good adhesion to a conductor substrate even after a heat history, and studies on improving stability at high temperatures by blending an anthracene skeleton or naphthalene skeleton-containing polymerization inhibitor and a latent thermosetting component are exemplified. However, in addition to the high-temperature stability of compounds having an ethylenically unsaturated double bond with three or more functional groups, sufficient studies have not been made to ensure the curing characteristics of resin compositions containing such compounds.

[0005] To ensure the long-term stability of compounds containing ethylenically unsaturated groups, it is common practice to add polymerization inhibitors that capture radicals generated during aging. However, in practice, while the addition of polymerization inhibitors is sufficiently effective for compounds with two-functional ethylenically unsaturated groups, for compounds with three or more functional ethylenically unsaturated groups, although the polymerization inhibitory effect is observed, the amount of radicals generated during aging is relatively large, and the effect is merely to delay the polymerization reaction, potentially leading to thickening or gelation over time. To address this problem, it is possible to create materials with excellent long-term stability by adding large amounts of polymerization inhibitors, but when the material is actually used, the polymerization reaction does not proceed as expected, resulting in a loss of the material's original polymerization performance and the physical properties of the cured product.

[0006] Among compounds having polyfunctional ethylenically unsaturated groups, compounds having a polyglycerol alkylene oxide skeleton are particularly difficult to ensure the long-term stability of the product. As can be seen from Figure 1 of Patent Document 3, resin compositions containing (meth)acrylic acid esters having a polyfunctional polyglycerol alkylene oxide skeleton are much more reactive than resin compositions that do not contain them. This is an effect based on the characteristic of generating a large amount of radicals and being less prone to deactivation, indicating that resin compositions containing (meth)acrylic acid esters having a polyglycerol alkylene oxide skeleton are more likely to undergo polymerization reactions.

[0007] Japanese Patent Publication No. 2017-223954, Japanese Patent Publication No. 2021-161204, Japanese Patent Publication No. 2018-178071

[0008] Therefore, the present invention aims to provide a polyglycerin alkylene oxide (meth)acrylic acid ester-containing active energy ray-curable resin composition that exhibits excellent high-temperature storage stability and long-term storage stability, and whose sensitivity and adhesion after curing are approximately the same before and after high-temperature and long-term storage.

[0009] The present inventors have conducted diligent studies and have found that the above problem can be solved by an active energy ray curable resin composition containing (A) a compound having a nitroso group, (A) a compound having a nitroso group, and (B) a polyfunctional (meth)acrylic acid ester having a polyoxyalkylene group with a polyglycerin skeleton as the main chain.

[0010] According to the present invention, by incorporating a compound having a nitroso group into a polyfunctional (meth)acrylic acid ester having polyoxyalkylene groups with a polyglycerin backbone as the main chain, the high-temperature and long-term storage stability can be improved. Furthermore, since the resin composition suppresses changes over time, the sensitivity and adhesion of the resin composition after curing are not significantly impaired before and after high-temperature and long-term storage.

[0011] The present invention will be described below based on embodiments. Hereinafter, the scope of the present invention is not limited to the embodiments described below, but also includes modified forms that do not impair the spirit of the invention. Note that the range indicated by "~" includes both an upper and lower limit.

[0012] The compound having a nitroso group (A) in the present invention is not particularly limited, but is preferably selected from nitroso compounds such as nitrosobutylamine, nitrosomethan, ammonium N-nitrosophenylhydroxyamine, and aluminum N-nitrosophenylhydroxyamine, and more preferably nitrosophenylhydroxyamine salts such as ammonium N-nitrosophenylhydroxyamine and aluminum N-nitrosophenylhydroxyamine, and there is no restriction on using one or more of them.

[0013] The compound having a nitroso group (A) of the present invention can also be used in combination with a heterocyclic compound. The heterocyclic compound is not particularly limited, but it is preferably selected from compounds having pyrrole, pyrrolidine, pyrrolidone, pyridine, pyrazine, piperidine, oxazole and thiazole, thiazine, triazole, tetrazole, pyrimidine, pyrazone, indole, benzimidazole, purine, benzotriazole, quinoline, isoquinoline, quinazoline, quinoxaline, and sinnoline structures, and there is no restriction on using one or more of them. Furthermore, compounds having nitrogen in the ring are more preferred, and examples include thiazine compounds and thiazole compounds.

[0014] The compound having a nitroso group (A) of the present invention is contained during the production of polyfunctional (meth)acrylic acid esters, during their storage, and during storage when used in active energy ray curable resin compositions.

[0015] The polyglycerin used in the polyfunctional (meth)acrylic acid ester having a polyoxyalkylene group with a polyglycerin skeleton as the main chain of the present invention preferably has an average degree of polymerization of 2 to 15, and more preferably 3 to 10. The polyglycerin has a structure in which the hydroxyl groups of glycerin are linked by ether bonds through dehydration condensation, and the ether bonds may be linear or branched, and may also contain intramolecularly condensed cyclic compounds. The average degree of polymerization of the polyglycerin is the average degree of polymerization (n) of the polyglycerin calculated from the hydroxyl value (OHV) by end group analysis. Specifically, the average degree of polymerization (n) is calculated from the following formulas (Formula 1) and (Formula 2). (Equation 1) Molecular weight = 74n + 18 (Equation 2) OHV = 56110(n + 2) / Molecular weight In (Equation 2) above, OHV is a numerical value that serves as an indicator of the number of hydroxyl groups (OH groups) contained in polyglycerin, and refers to the number of milligrams of potassium hydroxide required to neutralize the acetic acid necessary to acetylate the free OH groups contained in 1 g of polyglycerin. The number of milligrams of potassium hydroxide is calculated in accordance with the "Standard Test Methods for Analysis of Fats and Oils, 2013 Edition," edited by the Japan Oil Chemists' Society. Specific examples of polyglycerin include diglycerin, triglycerin, tetraglycerin, hexaglycerin, decaglycerin, and pentadecaglycerin. Commercially available products include diglycerin S, PGL-S, polyglycerin #310, polyglycerin #500, and polyglycerin #750 (all manufactured by Sakamoto Pharmaceutical Co., Ltd.).

[0016] The alkylene oxide used in the polyfunctional (meth)acrylic acid ester having polyoxyalkylene groups with a polyglycerin skeleton as the main chain in the present invention is preferably one with 2 to 4 carbon atoms. Examples include ethylene oxide, propylene oxide, and butylene oxide, with ethylene oxide and propylene oxide being particularly preferred. These alkylene oxides may be used alone or in combination of two or more. Block and random addition are possible, but there are no particular restrictions. The number of moles of polyoxyalkylene groups to be added to the polyglycerin skeleton is preferably 5 to 100 moles, more preferably 10 to 80 moles, and most preferably 20 to 60 moles per mole of polyglycerin. When the number of moles of polyoxyalkylene groups is within the above range, high-temperature and long-term storage stability can be improved, and the curing sensitivity and adhesion of the resin composition before and after high-temperature and long-term storage can be kept largely intact.

[0017] There are no particular limitations on the method for producing polyfunctional (meth)acrylic acid esters having polyoxyalkylene groups with a polyglycerin skeleton as the main chain according to the present invention. For example, there is a dehydration esterification method in which an arbitrary amount of alkylene oxide is added to a specific polyglycerin by a known method, and the resulting polyglycerin alkylene oxide adduct is heated and stirred with (meth)acrylic acid, and the resulting water is removed from the system while the reaction is carried out to obtain an esterified product; a transesterification method in which a polyglycerin alkylene oxide adduct is heated and stirred with a lower alcohol (meth)acrylic acid ester, and the resulting lower alcohol is removed from the system while the reaction is carried out to obtain an esterified product; and a method in which a polyglycerin alkylene oxide adduct is reacted with (meth)acrylic anhydride or (meth)acrylic acid halide such as (meth)acrylic acid chloride in the presence of a base such as a tertiary amine or pyridine to obtain an esterified product.

[0018] In the polyfunctional (meth)acrylic acid ester having polyoxyalkylene groups with a polyglycerin skeleton as the main chain (B) of the present invention, the effects of the present invention are more pronounced when there are five or more (meth)acrylic acid functional groups in one molecule. For this reason, it is preferable that the polyfunctional (meth)acrylic acid ester has five or more (meth)acrylic acid functional groups in one molecule, and more preferably five to twelve functional groups in one molecule. Due to the effects of the present invention, storage stability is improved, so that the crosslinking density and crosslinking reaction behave similarly to immediately after manufacture, and a significant decrease in the physical properties of the cured product, such as sensitivity during curing and adhesion of the cured product, can be suppressed.

[0019] In the present invention, (B) a polyfunctional (meth)acrylic acid ester having polyoxyalkylene groups with a polyglycerin skeleton as the main chain, a degree of esterification of 95% or more of (meth)acrylic acid reacted with the polyoxyalkylene groups with a polyglycerin skeleton as the main chain is preferable from a functional standpoint. A degree of 95% or more exhibits more pronounced functions that meet the requirements for curability, sensitivity, and ultimately, curing of fine patterns. The degree of esterification is an index that indicates the proportion to which (meth)acrylic acid reacts and esterifies with the reactable alcohol hydroxyl groups in the polyoxyalkylene groups attached to the polyglycerin skeleton, and can be calculated from the measurement of the saponification value.

[0020] The saponification value refers to the number of milligrams of potassium hydroxide required to hydrolyze 1 gram of an esterified substance. The number of milligrams of potassium hydroxide is calculated according to the "Standard Methods for Analyzing Fats and Oils, 2013 Edition," compiled by the Japan Oil Chemists' Society. The degree of esterification of (meth)acrylic acid esters can be calculated from the percentage of the measured saponification value relative to the theoretical saponification value.

[0021] The viscosity of the polyfunctional (meth)acrylic acid ester having polyoxyalkylene groups with a polyglycerin skeleton as the main chain in the present invention is preferably 100 mPa·s or higher, more preferably 150 to 1000 mPa·s, and even more preferably 200 to 800 mPa·s, from the viewpoint of coatability and the rate of crosslinking reaction. When the viscosity is within the above range, it contributes to the stability of the pattern after coating and contributes to the formation of a functional layer with high mechanical strength and durability after curing.

[0022] The content of the compound having a nitroso group (A) in the polyfunctional (meth)acrylic acid ester having a polyoxyalkylene group with a polyglycerin skeleton as the main chain (B) of the present invention can be included in a range that does not impair its functionality, and is preferably 0.0001% by mass or more and 0.02% by mass or less.

[0023] In the present invention, (B) a polyfunctional (meth)acrylic acid ester having polyoxyalkylene groups with a polyglycerin skeleton as the main chain, the stereostructure of the polyglycerin skeleton is not particularly limited, but linear polyglycerin and branched polyglycerin are preferred, and linear polyglycerin is more preferred. Linear polyglycerin refers to polyglycerin with a degree of branching (DB) of 0 to 0.25, and branched polyglycerin refers to polyglycerin with a degree of branching (DB) of 0 to 0.25. Hereinafter, the degree of branching (DB) will be explained.

[0024] The structural units that make up polyglycerin, which has a linear polyglycerin skeleton as its main chain, can be broadly classified into structures in which only one of the primary hydroxyl groups of glycerin is etherified (hereinafter referred to as "Terminal structure"), structures in which one primary hydroxyl group and one secondary hydroxyl group are etherified (hereinafter referred to as "Linear 1,3 structure"), structures in which both primary hydroxyl groups are etherified (hereinafter referred to as "Linear 1,4 structure"), and structures in which all three hydroxyl groups are etherified (hereinafter referred to as "Dendristic structure").

[0025] Each of the above-mentioned structural units can be classified based on measurements by 13C-NMR, and the amount of each structure can be calculated from the 13C-NMR measurement results based on the integral ratio of peaks identified at specific positions of carbon atoms in each structure: the Terminal (T) structure, Linear 1,3 structure, Linear 1,4 structure, and Dendritic structure.

[0026] The degree of branching (DB) can be calculated using the formula: Degree of branching (DB) = 2D / (2D + L13 + L14). Here, polyglycerin with a degree of branching (DB) in the range of 0 to 0.25 is referred to as linear polyglycerin. This improves storage stability.

[0027] The active energy ray curable resin composition of the present invention, which contains (A) a compound having a nitroso group and (B) a polyfunctional (meth)acrylic acid ester having a polyoxyalkylene group with a polyglycerin skeleton as the main chain, may also contain, alone or in combination of two or more, quinone-based polymerization inhibitors such as p-methoxyphenol, hydroquinone, methoxyhydroquinone, and p-tert-butylcatechol; alkylphenol-based polymerization inhibitors such as 2,6-di-tert-butylphenol and 2,6-di-tert-butyl-4-cresol; and amine-based polymerization inhibitors such as alkylated diphenylamine, N,N'-diphenyl-p-phenylenediamine, and 4-hydroxy-2,2,6,6-tetramethylpiperidine.

[0028] The active energy ray curable resin composition of the present invention is characterized by containing (A) a compound having a nitroso group and (B) a polyfunctional (meth)acrylic acid ester having a polyoxyalkylene group with a polyglycerin skeleton as the main chain. However, other (meth)acrylic acid ester monomers other than the (meth)acrylic acid ester used in the present invention may be used alone or in combination of two or more. They can be used in any proportion to the resin composition as long as the performance is not impaired.

[0029] In the active energy ray curable resin composition of the present invention, other (meth)acrylic acid ester monomers other than the (meth)acrylic acid ester used in the present invention include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, isoamyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, isomiristyl (meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, Methoxydipropylene glycol (meth)acrylate, 2-ethoxyethyl (meth)acrylate, ethoxy-diethylene glycol (meth)acrylate, butoxyethyl (meth)acrylate, 2-ethylhexyldiethoxy (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobonyl (meth)acrylate, benzyl (meth)acrylate, carbitol (meth)acrylate, ethyl carbitol (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, hydrogenated dicyclopentadiene (meth)acrylate, acryloylmorpholine, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 2-n-butyl-2-ethyl-3-propanediol di(meth)acrylate, tricyclodecane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, trimethylolpropane polyethoxytri(meth)acrylate, trimethylolpropane polypropoxytri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, glycerin polyethoxytri(meth)acrylate, glycerin polypropoxy Examples of monomers include citri(meth)acrylate, bisphenol A polyethoxydi(meth)acrylate, bisphenol A polypropoxydi(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol polyethoxyhexa(meth)acrylate, and dipentaerythritol polypropoxyhexa(meth)acrylate.

[0030] The active energy curable resin composition of the present invention can be cured by known methods. Active energy rays are a general term for electromagnetic waves such as electron beams, X-rays, ultraviolet rays, and visible light in the low wavelength region, and ultraviolet rays are generally preferred due to the simplicity and widespread use of the equipment. There are many types of equipment that can irradiate with ultraviolet rays, and any can be selected. High-pressure mercury lamps, metal halide lamps, xenon lamps, LEDs, etc. can be used as light sources.

[0031] When curing using ultraviolet light as the active energy ray, it is necessary to use a radical polymerization type photopolymerization initiator. Any known photopolymerization initiator may be used. Examples include intramolecular cleavage initiators such as benzyl ketals, α-hydroxyacetophenones, aminoacetophenones, acylphosphine oxides, oxime esters, and benzoins, and hydrogen abstraction initiators such as benzophenones, thioxanthones, and arylbiimidazoles. These may be used individually or in combination of two or more.

[0032] Furthermore, when using a photopolymerization initiator, one or more photosensitizers can be used in combination.

[0033] The active energy ray curable resin composition of the present invention may optionally contain non-reactive polymer resins such as polyester elastomers, polyurethane elastomers, and acrylic polymers, as well as reactive polymer resins such as polydiallyl phthalate, polydiallyl isophthalate, urethane (meth)acrylic acid ester oligomers, polyester (meth)acrylic acid ester oligomers, epoxy (meth)acrylic acid ester oligomers, and acrylic polymers, to the extent that the effects of the present invention are not impaired.

[0034] The active energy ray curable resin composition of the present invention may optionally contain organic solvents such as acetone, methyl ethyl ketone, ethanol, toluene, hexane, ethyl acetate, methyl cellosolve, propylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, or propylene glycol monomethyl ether acetate, as long as the effects of the present invention are not impaired.

[0035] The active energy ray curable resin composition of the present invention may optionally contain additives such as surfactants (nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, etc.), leveling agents, defoaming agents, silane coupling agents, antioxidants, ultraviolet absorbers, colorants, light stabilizers, heat stabilizers, polymerization inhibitors, pigments, metal oxide fine particle dispersions, antifogging agents, dyes, etc., to the extent that the effects of the present invention are not impaired.

[0036] The active energy ray-curable resin composition of the present invention can form a cured film with excellent sensitivity and adhesion without impairing sensitivity or adhesion, and when cured with active energy rays, it can be formed into various forms such as coatings, films, and three-dimensional molded objects by known methods. Furthermore, it can be applied to a wide range of substrates, including plastic substrates such as polyethylene terephthalate resin (PET resin), polycarbonate resin (PC), polystyrene resin (PS), and polyolefin resin (PP resin, PE resin), and polymethyl methacrylate (PMMA), as well as inorganic substrates such as metals and glass.

[0037] Furthermore, the cured product can be widely applied to coatings such as hard coats, linings, adhesives, paints, inks, and resist materials for optical materials, electronic materials, printed circuit boards, etc.

[0038] The present invention will be described below with reference to synthesis examples and embodiments, but the present invention is not limited in any way by these.

[0039] <Synthesis Example 1> In a reaction vessel, a dehydration esterification reaction was carried out using a 60-mol adduct of decaglycerin with ethylene oxide (manufactured by Sakamoto Pharmaceutical Co., Ltd.), toluene, p-toluenesulfonic acid, hydroquinone monomethyl ether, acrylic acid, phenothiazine, and 0.01% by mass of aluminum N-nitrosophenylhydroxyamine to obtain an acrylic acid ester with a degree of esterification of 95% of the 60-mol adduct of decaglycerin with ethylene oxide and a viscosity of 600 mPa·s (A1).

[0040] <Synthesis Example 2> In a reaction vessel, a dehydration esterification reaction was carried out using a 60-mol adduct of decaglycerin with ethylene oxide (manufactured by Sakamoto Pharmaceutical Co., Ltd.), toluene, acrylic acid, p-toluenesulfonic acid, and 0.01% by mass of aluminum N-nitrosophenylhydroxyamine to obtain an acrylic acid ester with a degree of esterification of 98% of the 60-mol adduct of decaglycerin with ethylene oxide and a viscosity of 530 mPa·s (A2).

[0041] <Synthesis Example 3> Using the same method as in Synthesis Example 1, a dehydration esterification reaction was carried out using a 60-mol ethylene oxide adduct of decaglycerin (manufactured by Sakamoto Pharmaceutical Co., Ltd.), toluene, p-toluenesulfonic acid, hydroquinone monomethyl ether, methacrylic acid, phenothiazine, and 0.01% by mass of aluminum N-nitrosophenylhydroxyamine to obtain a methacrylic acid ester with a degree of esterification of 99% of the 60-mol ethylene oxide adduct of decaglycerin and a viscosity of 350 mPa·s (M1).

[0042] <Synthesis Example 4> Using the same method as in Synthesis Example 1, 1 mole of polyglycerin, obtained by mixing decaglycerin (manufactured by Sakamoto Pharmaceutical Co., Ltd.) and hexaglycerin (manufactured by Sakamoto Pharmaceutical Co., Ltd.) in a molar ratio of 1:1, was added to 40 moles of ethylene oxide. This compound was then subjected to a dehydration esterification reaction using toluene, p-toluenesulfonic acid, hydroquinone monomethyl ether, methacrylic acid, phenothiazine, and 0.007% by mass of aluminum N-nitrosophenylhydroxyamine. This resulted in a methacrylic acid ester with a degree of esterification of 99% and a viscosity of 330 mPa·s, obtained from the polyglycerin (made by mixing decaglycerin and hexaglycerin in a molar ratio of 1:1) and 40 moles of ethylene oxide adduct (M2).

[0043] <Synthesis Example 5> Using the same method as in Synthesis Example 1, 1 mole of polyglycerin, obtained by mixing decaglycerin (manufactured by Sakamoto Pharmaceutical Co., Ltd.) and hexaglycerin (manufactured by Sakamoto Pharmaceutical Co., Ltd.) in a molar ratio of 1:1, was added to a compound to which 20 moles each of ethylene oxide and propylene oxide were added. This compound was then subjected to a dehydration esterification reaction using toluene, p-toluenesulfonic acid, hydroquinone monomethyl ether, methacrylic acid, phenothiazine, and 0.008% by mass of aluminum N-nitrosophenylhydroxyamine. This resulted in a methacrylic acid ester with a degree of esterification of 99% of the decaglycerin and hexaglycerin adducts of 20 moles of ethylene oxide and 20 moles of propylene oxide, and a viscosity of 400 mPa·s (M3).

[0044] <Synthesis Example 6> Using the same method as in Synthesis Example 1, ethylene oxide 60 mol adduct of tetraglycerin (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), toluene, p-toluenesulfonic acid, hydroquinone monomethyl ether, methacrylic acid, phenothiazine, and 0.01% by mass of aluminum N-nitrosophenylhydroxylamine, a dehydration esterification reaction was carried out to obtain a methacrylic acid ester with an esterification degree of 99% and a viscosity of 430 mPa·s of the ethylene oxide 60 mol adduct of tetraglycerin (M4).

[0045] <Comparative Synthesis Example 1> Using ethylene oxide 60 mol adduct of decaglycerin (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), toluene, p-toluenesulfonic acid, hydroquinone monomethyl ether, and acrylic acid, a dehydration esterification reaction was carried out to obtain an acrylic acid ester with an esterification degree of 90% and a viscosity of 700 mPa·s of the ethylene oxide 60 mol adduct of decaglycerin (A3).

[0046] <Comparative Synthesis Example 2> Using the same method as in Synthesis Example 1, ethylene oxide 60 mol adduct of decaglycerin (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), toluene, p-toluenesulfonic acid, hydroquinone monomethyl ether, methacrylic acid, and phenothiazine, a dehydration esterification reaction was carried out to obtain a methacrylic acid ester with an esterification degree of 99% and a viscosity of 350 mPa·s of the ethylene oxide 60 mol adduct of decaglycerin (M5).

[0047] <Comparative Synthesis Example 3> Using the same method as in Synthesis Example 1, toluene, p-toluenesulfonic acid, hydroquinone monomethyl ether, and methacrylic acid were used for a compound obtained by adding 24 mol of ethylene oxide to 1 mol of hexaglycerin (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), and a dehydration esterification reaction was carried out to obtain a methacrylic acid ester with an esterification degree of 99% and a viscosity of 250 mPa·s of the ethylene oxide 24 mol adduct of hexaglycerin (M6).

[0048] <Comparative Synthesis Example 4> Using the same method as in Synthesis Example 1, to a compound obtained by adding 8 moles each of ethylene oxide and propylene oxide to 1 mole of diglycerin (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), toluene, p-toluenesulfonic acid, hydroquinone monomethyl ether, and methacrylic acid were used to cause a dehydration esterification reaction, thereby obtaining a methacrylic acid ester with an esterification degree of 90% and a viscosity of 110 mPa·s of an adduct of 8 moles of ethylene oxide and 8 moles of propylene oxide of diglycerin (M7).

[0049] <Measurement of Viscosity> The viscosities of Synthesis Examples 1 to 6 and Comparative Synthesis Examples 1 to 4 were measured using an E-type viscometer (HBDV-II + ProCP, manufactured by BROOKFIELD). CPE-40 was used for the spindle, and the viscosity at 25°C was measured with a sampling volume of 0.5 mL.

[0050] <Storage Stability at High Temperature> For Synthesis Examples 1 to 6 and Comparative Synthesis Examples 1 to 4, 50 g each was taken into a 100 ml glass container, the lid was closed in a light-shielded state, and after heating in a constant-temperature dryer at 90°C for 24 hours and 120 hours, it was gradually cooled to room temperature, and the state of the content was visually observed and judged according to the following criteria, and the results are shown in Table 1. For each storage time, those with all ○ evaluations were judged to be good, and those with at least △ or × evaluations were judged to be bad. 〇: No gelation △: Signs of gelation (thickening) are observed ×: Gelation

[0051] <Examples 1 to 6, Comparative Examples 1 to 4>

[0052] From Comparative Examples 1 to 4, in a resin composition in which a compound having a nitroso group is not blended in a polyfunctional (meth)acrylic acid ester having a polyoxyalkylene group with a polyglycerin skeleton as the main chain, the high-temperature stability and stability over time are poor. It is considered that as the degree of polymerization of polyglycerin increases, the number of functional groups increases, and the storage stability at high temperature and over time decreases. On the other hand, in Examples 1 to 6, which are resin compositions blended with a compound having a nitroso group, it was found that even in a system with a large degree of polymerization of polyglycerin and a large number of functional groups, the high-temperature stability and stability over time are excellent.

[0053] <Sensitivity and Adhesion Evaluation> <Examples 7-10> 50 parts by weight of acrylic polymer (ARUFON UF-5080) was dissolved in 50 parts of methyl ethyl ketone solvent. 1 part of phenoxydiethylene glycol acrylate, 24 parts of ethylene oxide-modified bisphenol A diacrylate, 15 parts each of polyfunctional (meth)acrylic acid esters from Synthesis Examples 1, 3-5 (stored in a constant temperature dryer at 90°C for 24 hours, and then stored in a constant temperature dryer for 120 hours), 3 parts of photopolymerization initiator aryl biimidazoles (BCIM), 0.1 parts of benzophenones (OminardEMK), and 0.1 parts of leuco dye were added and the mixture was stirred and mixed in a rotary mixer to obtain an active energy ray-curable resin composition. An appropriate amount of active energy ray-curable resin composition was dropped onto a copper-clad laminate, then applied using an applicator (four-sided applicator), and heated at 100°C for 5 minutes. Exposure was performed using a mask aligner. For sensitivity, the exposure intensity was measured using an illuminometer (Ushio Inc.: UIT-150) after passing through an i-line bandpass filter. Using line and space (L / S) patterns with line widths / spacings of 5, 10, 15, 20, 30, 40, 60, 80, and 100 μm, the sensitivity when L / S was in the range of 0.95 to 1.05 was considered the optimal exposure. If the optimal exposure could not be measured, it was evaluated as ×. Regarding adhesion, after alkali development of the active energy ray-cured material at the optimal exposure, the line areas were inspected with a digital microscope (VHX-800). The adhesion score was determined by the thinnest line width in which all five lines for each of the 5, 10, 15, 20, 30, 40, 60, 80, and 100 μm widths remained without any defects. If five lines were not remaining without defects for any of the 5, 10, 15, 20, 30, 40, 60, 80, and 100 μm line widths, it was evaluated as ×. Then, the sensitivity and adhesion after 24 hours and 120 hours of heating were judged as good if they were approximately the same as those immediately after manufacturing (before high-temperature heating and storage), and as poor if they were significantly worse.

[0054] <Comparative Examples 5-8> Except for using the polyfunctional (meth)acrylic acid esters from Comparative Synthesis Examples 1-4, the components were prepared by stirring and mixing them in predetermined amounts in the same manner as in Examples 7-10.

[0055]

[0056] Examples 7-10 and Comparative Examples 5-8 show that when comparing the sensitivity and adhesion of resin compositions containing a compound with a nitroso group to those without, it was found that the resin compositions containing a compound with a nitroso group, such as Examples 7-10, maintained approximately the same functionality of the cured product even after high-temperature storage compared to high-temperature storage.

[0057] The present invention has found that an active energy ray-curable resin composition comprising (A) a compound having a nitroso group and (B) a polyfunctional (meth)acrylic acid ester having polyoxyalkylene groups with a polyglycerin backbone as the main chain exhibits excellent stability even after high temperature and long-term storage, and furthermore, can be expressed without impairing sensitivity and adhesion performance. It can be suitably used in applications such as coating agents for hard coats, lining agents, adhesives, paints, inks, and resist materials for optical materials, electronic materials, printed circuit boards, etc.

Claims

1. An active energy ray curable resin composition containing (A) a compound having a nitroso group, and (B) a polyfunctional (meth)acrylic acid ester having a polyoxyalkylene group with a polyglycerol skeleton as the main chain.

2. The active energy ray curable resin composition according to claim 1, characterized in that the compound having a nitroso group (A) is ammonium N-nitrosophenylhydroxyamine and / or aluminum N-nitrosophenylhydroxyamine.

3. The active energy ray curable resin composition according to claim 1, characterized in that the polyfunctional (meth)acrylic acid ester having polyoxyalkylene groups with a polyglycerin skeleton as the main chain has five or more (meth)acrylic functional groups and its degree of esterification is 95% or more.

4. The active energy ray curable resin composition according to claim 1, wherein the viscosity of the polyfunctional (meth)acrylic acid ester having polyoxyalkylene groups with a polyglycerin skeleton as the main chain is 100 mPa·s or more.

5. A cured product obtained by curing the active energy ray curable resin composition described in claim 1.

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