Active energy ray-curable composition, cured product, electronic component, and method for producing cured product

Abstract

An active energy ray-curable composition according to the present disclosure contains the following components (A) and (B).　Component (A): urethane (meth)acrylate polymer having a weight average molecular weight of 20,000 or more and a hydrogenated polybutadiene skeleton. Component B: water-insoluble monofunctional (meth)acrylate having at least one imide group, hydroxyl group, and 1,3-dioxolane ring and having no amide group

Description

Active energy ray curable composition, cured product, electronic component, and method for producing the cured product

[0001] The present disclosure relates to an active energy ray-curable composition, a cured product, an electronic component, and a method for producing the cured product.

[0002] Active energy ray-curable compositions that are cured by irradiation with active energy rays (such as ultraviolet rays) have attracted attention because they have high productivity since the curing reaction is completed in a short time.

[0003] Since an active energy ray-curable composition that does not contain a solvent is solvent-free, it does not release solvents or the like into the environment. Therefore, it has a low environmental impact. Since an active energy ray-curable composition does not require heating, products can be produced with low energy, and further, its rapid curing property reduces production costs (Patent Document 1).

[0004] As active energy ray-curable compositions used for potting or coating of electronic components (for example, printed wiring boards or integrated circuits), photocurable compositions containing, as a main component, a urethane (meth)acrylate polymer having a hydrogenated polybutadiene skeleton have been reported (Patent Documents 2 to 4).

[0005] Patent Document 1: JP 2019-196461 A Patent Document 2: JP-B-7-33415 A Patent Document 3: JP-A-7-138332 A Patent Document 4: JP 2020-158674 A

[0006] In recent years, high durability has been required for cured products (e.g., potting or coatings, etc.) Specifically, in anticipation of in-vehicle applications, etc., there is a demand for cured products that have excellent adhesive properties to polyimide substrates (hereinafter also referred to as "polyimide substrates"), which are used as printed wiring board materials, and that have excellent electrical insulation properties after long-term exposure to high temperature and high humidity.

[0007] In Patent Document 4, the adhesive performance to polyimide substrates is specifically investigated using a urethane (meth)acrylate polymer having a hydrogenated polybutadiene skeleton with a weight average molecular weight (Mw) of 16,800 or 10,000. However, the adhesive performance to polyimide substrates is insufficient.

[0008] Furthermore, Patent Documents 2 to 4 do not consider the electrical insulating performance of the cured product under high temperature and high humidity conditions for a long period of time.

[0009] The present disclosure has been made in view of the above circumstances. An object of the present disclosure is to provide an active energy ray-curable composition, a cured product, an electronic component, and a method for producing the cured product, which are capable of producing a cured product that has excellent adhesion to polyimide substrates and excellent electrical insulation performance after long-term exposure to high temperature and high humidity.

[0010] Specific means for solving the above problems include the following aspects.

[0011] <1> An active energy ray-curable composition comprising the following component (A) and component (B): Component (A): a urethane (meth)acrylate polymer having a weight-average molecular weight of 20,000 or more and having a hydrogenated polybutadiene skeleton; and Component (B): a water-insoluble monofunctional (meth)acrylate having at least one of an imide group, a hydroxyl group, and a 1,3-dioxolane ring, and not having an amide group. <2> The active-energy ray-curable composition according to <1> above, further comprising the following component (C): and optionally further comprising the following component (D): the content of component (A) is 20 parts by mass to 50 parts by mass, the content of component (B) is 10 parts by mass to 30 parts by mass, the content of component (C) is 35 parts by mass to 50 parts by mass, and the content of component (D) is 0 parts by mass to 10 parts by mass, relative to 100 parts by mass of the total amount of the components (A), (B), (C), and (D). Component (C): a monofunctional (meth)acrylate having an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and having no imide group, hydroxyl group, 1,3-dioxolane ring, or amide group; Component (D): a monofunctional (meth)acrylate having an amide group. <3> The active energy ray-curable composition according to <2> above, wherein the urethane (meth)acrylate polymer of component (A) has a weight-average molecular weight of 30,000 or more. <4> The active energy ray-curable composition according to <2> or <3> above, wherein the monofunctional (meth)acrylate of component (B) has at least one of an imide group and a hydroxyl group. <5> The active energy ray-curable composition according to any one of <2> to <4> above, wherein the monofunctional (meth)acrylate of component (B) has at least one of an imide group, a hydroxyl group, and a phenoxy group. <6> The active energy ray-curable composition according to any one of <2> to <5>, wherein the urethane (meth)acrylate polymer of component (A) is a polymer obtained by adding a hydroxyalkyl (meth)acrylate having an alkyl group containing 3 to 6 carbon atoms to a urethane prepolymer having an isocyanate group and a hydrogenated polybutadiene skeleton. <7> The active energy ray-curable composition according to any one of <2> to <6>, further comprising component (D), wherein the content of component (D) is 1 to 5 parts by mass per 100 parts by mass of the total amount.<8> A cured product obtained by curing the active energy ray-curable composition according to any one of <1> to <7>. <9> An electronic component comprising the cured product according to <8> and a substrate on which the cured product is formed. <10> A method for producing a cured product, comprising irradiating the active energy ray-curable composition according to any one of <1> to <7> with active energy rays from a light-emitting diode to cure the active energy ray-curable composition.

[0012] According to one embodiment of the present disclosure, there are provided an active energy ray-curable composition capable of producing a cured product that has excellent adhesion to polyimide substrates and excellent electrical insulation performance after long-term exposure to high temperature and high humidity, a cured product, an electronic component, and a method for producing the cured product.

[0013] In this disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the upper and lower limits. In this disclosure, when multiple substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the multiple substances present in the composition, unless otherwise specified. In numerical ranges described in stages in this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. In numerical ranges described in this disclosure, the upper or lower limit of that numerical range may be replaced with a value shown in the examples. In this disclosure, combinations of preferred embodiments are more preferred embodiments. In the description of groups (atomic groups) in this disclosure, a description that does not specify whether they are substituted or unsubstituted includes both unsubstituted and substituted groups. In this disclosure, "(meth)acrylate" means at least one of acrylate and methacrylate. "Urethane (meth)acrylate" means a (meth)acrylate polymer having a urethane skeleton. The term "(meth)acryloyl group" means at least one of an acryloyl group and a methacryloyl group.

[0014] (1) Active Energy Ray-Curable Composition The active energy ray-curable composition of the present disclosure (hereinafter also referred to as the "composition of the present disclosure") contains the following components (A) and (B): Component (A): a urethane (meth)acrylate polymer having a weight average molecular weight (hereinafter also referred to as "Mw") of 20,000 or more and having a hydrogenated polybutadiene skeleton; Component (B): a water-insoluble monofunctional (meth)acrylate having at least one of an imide group, a hydroxyl group, and a 1,3-dioxolane ring, but not an amide group;

[0015] The term "active energy ray-curable composition" refers to a composition that cures upon irradiation with active energy rays (e.g., visible light, ultraviolet light, X-rays, electron beams, etc.). The term "urethane (meth)acrylate polymer having a hydrogenated polybutadiene skeleton" refers to a polymer having a hydrogenated polybutadiene skeleton, a (meth)acryloyl group, and a urethane bond in the molecule. The term "urethane (meth)acrylate polymer" refers to a polymer obtained by adding a (meth)acrylate having a hydroxyl group to a urethane prepolymer having an isocyanate group. The term "urethane prepolymer" refers to a polymer obtained by reacting a polydiene diol with a diisocyanate, and having an isocyanate group at the molecular end. The term "water-insoluble monofunctional (meth)acrylate" refers to a monofunctional (meth)acrylate in which 30 mL or more of solvent is required to dissolve 1 g of the monofunctional (meth)acrylate. The term "monofunctional (meth)acrylate" refers to a (meth)acrylic compound having one (meth)acryloyl group in one molecule.

[0016] The composition of the present disclosure, having the above-described structure, can provide a cured product that exhibits excellent adhesion to polyimide substrates and excellent electrical insulation performance after long-term exposure to high temperatures and humidity. The term "polyimide substrate" refers to a substrate containing polyimide. This effect is presumably due to, but not limited to, the following reasons: A cured polyester product does not exhibit adhesion to polyimide substrates. In addition, when a cured polyester product is exposed to high temperatures and humidity for a long period of time, the hydrolysis reaction of the cured polyester product is likely to proceed. In other words, the electrical insulation performance of the cured polyester product is likely to deteriorate. On the other hand, the composition of the present disclosure contains component (A). Therefore, a cured product of the composition of the present disclosure (hereinafter also referred to as the "cured product of the present disclosure") exhibits adhesion to polyimide substrates. In addition, even when the component (A) is exposed to high temperatures and humidity for a long period of time, the hydrolysis reaction of the component (A) is unlikely to proceed. In other words, the electrical insulation performance of the cured product of the present disclosure is unlikely to deteriorate. Furthermore, the composition of the present disclosure contains component (B). As a result, it is believed that the hydroxyl group or 1,3-dioxolane ring of component (B) forms a hydrogen bond with the imide group of the polyimide substrate or with water on the polyimide surface. The imide group of component (B) is believed to improve the cohesive strength with the polyimide substrate. As a result, the cured product of the present disclosure has high adhesion to the polyimide substrate. In addition, the monofunctional (meth)acrylate of component (B) is water-insoluble. Therefore, the electrical insulating performance of the cured product of the present disclosure is less likely to deteriorate even after prolonged exposure to high temperatures and humidity than when the monofunctional (meth)acrylate is water-soluble. From the above, it is presumed that the composition of the present disclosure can provide a cured product that has excellent adhesion to polyimide substrates and excellent electrical insulating performance after prolonged exposure to high temperatures and humidity.

[0017] In addition to the components (A) and (B), the composition of the present disclosure may further contain the following components (C) and (D), as necessary: ​​Component (C): a monofunctional (meth)acrylate having an aliphatic hydrocarbon group and having no imide group, hydroxyl group, 1,3-dioxolane ring, or amide group; and Component (D): a monofunctional (meth)acrylate having an amide group.

[0018] The composition of the present disclosure is preferably used for moisture-proof insulation. Specific applications of the composition of the present disclosure include adhesives, potting materials, and coating materials for electrical applications.

[0019] (1.1) Component (A) The composition of the present disclosure includes component (A) as a curable component. Component (A): a urethane (meth)acrylate polymer having a Mw of 20,000 or more and a hydrogenated polybutadiene skeleton.

[0020] The Mw of component (A) is 20,000 or more, preferably 27,000 or more, more preferably 30,000 or more, and even more preferably 35,000 or more. The Mw of polymer (A) is preferably 80,000 or less, more preferably 60,000 or less. The Mw of polymer (A) may be 20,000 to 60,000. The number average molecular weight (Mn) of component (A) may be 5,000 to 30,000, or 10,000 to 20,000. The average molecular weight is a value measured by gel permeation chromatography (hereinafter also referred to as "GPC"). During GPC measurement, a polystyrene gel column is used with tetrahydrofuran as the mobile phase, and the molecular weight value is determined in terms of polystyrene.

[0021] The (A) component may be a urethane reaction product of a hydrogenated polydiene diol (a1), a diisocyanate (a2), and a (meth)acrylate (a3) ​​having a hydroxyl group. Specifically, the (A) component may be obtained by the first or second production method. The "first production method" refers to a method in which a hydrogenated polydiene diol (a1) is reacted with a diisocyanate (a2) to obtain a urethane prepolymer having an isocyanate group and a hydrogenated polybutadiene skeleton, and the urethane prepolymer is then reacted with a (meth)acrylate (a3) ​​having a hydroxyl group. The "second production method" refers to a method in which a hydrogenated polydiene diol (a1), a diisocyanate (a2), and a (meth)acrylate (a3) ​​having a hydroxyl group are reacted. From the viewpoints of ease of molecular weight control and the solubility of the polydiene urethane (meth)acrylate in other components, the (A) component is preferably obtained by the first production method. A known catalyst may be used in the production of component (A).

[0022] (1.1.1) Hydrogenated Polydiene Diol (a1) Examples of the hydrogenated polydiene diol (a1) include hydrogenated polybutadiene diol, hydrogenated polyisoprene diol, and hydrogenated products of butadiene-styrene copolymer diol. The hydrogenated polydiene diol (a1) may be used alone or in combination of two or more. The number average molecular weight (Mn) of the hydrogenated polydiene diol (a1) may be 500 to 5,000, or 1,000 to 4,000. The hydrogenated polydiene diol (a1) may be a commercially available product.

[0023] (1.1.2) Diisocyanate (a2) Examples of the diisocyanate (a2) include: aliphatic diisocyanates such as hexamethylene diisocyanate; alicyclic diisocyanates such as isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated xylylene diisocyanate; and aromatic diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, tolidine diisocyanate, naphthalene diisocyanate, and xylylene diisocyanate. The diisocyanate (a2) may be used singly or in combination of two or more.

[0024] The molar ratio of the hydrogenated polydiene diol (a1) to the diisocyanate (a2) ((a1):(a2)) is preferably 1:2.2 to 1:1.05, more preferably 1:2 to 1:1.1, and even more preferably 1:1.8 to 1:1.1. The component (A) obtained by reaction at this ratio has excellent solubility with other (meth)acrylates, and the cured product of the present disclosure has even better adhesive strength.

[0025] (1.1.3) (Meth)acrylate (a3) ​​Having a Hydroxy Group Examples of the (meth)acrylate (a3) ​​having a hydroxyl group include hydroxyalkyl (meth)acrylates represented by the following formula (I), caprolactone-modified 2-hydroxyethyl (meth)acrylate, and glycidol di(meth)acrylate. The (meth)acrylate (a3) ​​having a hydroxyl group may be used alone or in combination of two or more.

[0026]

[0027] In formula (I), R represents a linear or branched alkyl group having 1 to 10 carbon atoms.

[0028] From the viewpoint of improving the adhesive performance to the polyimide substrate, the (meth)acrylate (a3) ​​having a hydroxyl group preferably contains a hydroxyalkyl (meth)acrylate, and more preferably is a hydroxyalkyl (meth)acrylate.

[0029] Examples of hydroxyalkyl (meth)acrylates include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, hydroxyheptyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxynonyl (meth)acrylate, and hydroxydecyloctyl (meth)acrylate.

[0030] The number of carbon atoms in the alkyl of the hydroxyalkyl (meth)acrylate is preferably 3 to 10, more preferably 3 to 8, and even more preferably 3 to 5, from the viewpoint of improving adhesive performance to polyimide substrates.

[0031] The amount of the (meth)acrylate (a3) ​​having a hydroxyl group is not particularly limited. In the first production method, the ratio of the isocyanate group equivalent of the urethane prepolymer to the hydroxyl group equivalent of the (meth)acrylate (a3) ​​having a hydroxyl group (isocyanate group equivalent:hydroxyl group equivalent) may be 1:0.1 to 1:0.8, or may be 1:0.2 to 1:0.6.

[0032] (1.1.4) Content of Component (A) From the viewpoint of improving the adhesive performance of the cured product of the present disclosure to a polyimide substrate, the content of component (A) is preferably 20 parts by mass to 50 parts by mass, and more preferably 25 parts by mass to 45 parts by mass, relative to 100 parts by mass of the total amount of the composition of the present disclosure. When the composition of the present disclosure contains components (A), (B), (C), and (D) (hereinafter also referred to as "components (A) to (D)"), the content of component (A) may be 20 parts by mass to 50 parts by mass, 25 parts by mass to 45 parts by mass, or 30 parts by mass to 40 parts by mass, relative to 100 parts by mass of the total amount of components (A) to (D).

[0033] (1.2) Component (B) The composition of the present disclosure contains component (B) as a curable component. Component (B): a water-insoluble monofunctional (meth)acrylate having at least one of an imide group, a hydroxyl group, and a 1,3-dioxolane ring, but no amide group.

[0034] Examples of monofunctional (meth)acrylates having an imide group include N-(meth)acryloyloxyethylhexahydrophthalimide, N-(meth)acryloyloxyethyltetrahydrophthalimide, 2-(1,2-cyclohex-1-enedicarboximide)ethyl (meth)acrylate, and Fancryl FA-502A (manufactured by Showa Denko Materials Co., Ltd.). Examples of monofunctional (meth)acrylates having a hydroxyl group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, hydroxyhexyl (meth)acrylate, and hydroxyoctyl (meth)acrylate; and 2-hydroxy-3-phenoxypropyl (meth)acrylate. Examples of monofunctional (meth)acrylates having a 1,3-dioxolane ring include (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclohexanespiro-2-(1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-oxo-1,3-dioxolan-4-yl)methyl (meth)acrylate, and 2-((2-oxo-1,3-dioxolan-4-yl)methoxy)ethyl (meth)acrylate. The component (B) may be used singly or in combination of two or more.

[0035] The glass transition temperature (Tg) of component (B) is not particularly limited, but is preferably -15°C or higher, more preferably -12°C to 80°C, and even more preferably -10°C to 70°C. When the Tg of component (B) is -15°C or higher, the cured product of the present disclosure has superior adhesive performance to polyimide substrates in the usage temperature range (e.g., 20°C or higher). Tg may be measured using a differential scanning calorimeter under conditions of a heating rate of 20°C / min in a nitrogen atmosphere. The amount of sample used for measurement may be 5 mg to 10 mg.

[0036] The monofunctional (meth)acrylate of component (B) preferably has at least one of an imide group and a hydroxyl group, which provides the cured product of the present disclosure with better adhesion to polyimide substrates than when the monofunctional (meth)acrylate of component (B) has a 1,3-dioxolane ring.

[0037] The monofunctional (meth)acrylate of component (B) preferably has an imide group and at least one of a hydroxyl group and a phenoxy group, thereby providing the cured product of the present disclosure with better adhesion to polyimide substrates than a monofunctional (meth)acrylate of component (B) having only a hydroxyl group as a reactive group.

[0038] The content of component (B) is not particularly limited, and may be 20 parts by mass to 150 parts by mass, or 40 parts by mass to 100 parts by mass, relative to 100 parts by mass of the content of component (A). When the composition of the present disclosure includes components (A) to (D), the content of component (B) may be 10 parts by mass to 30 parts by mass, 15 parts by mass to 25 parts by mass, or 17 parts by mass to 22 parts by mass, relative to 100 parts by mass of the total amount of components (A) to (D).

[0039] (1.3) Component (C) The composition of the present disclosure may further contain component (C) in addition to components (A) and (B). Component (C) functions as a solvent for components (A) and (B). Component (C) may be used as a diluent in the above-mentioned first and second production methods for component (A). Component (C): a monofunctional (meth)acrylate having an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and having no imide group, hydroxyl group, 1,3-dioxolane ring, or amide group.

[0040] Examples of monofunctional (meth)acrylates having an aliphatic hydrocarbon group include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, and octyl (meth)acrylate. Examples of the acrylates include butyl (meth)acrylate, ... Examples of monofunctional (meth)acrylates having an alicyclic hydrocarbon group include bornyl (meth)acrylate, isobornyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dicyclopentanyl (meth)acrylate, 4-butylcyclohexyl (meth)acrylate, cyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, dicyclopentenyl (meth)acrylate, adamantyl (meth)acrylate, tricyclodecane (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate. The component (C) may be used singly or in combination of two or more.

[0041] When the composition of the present disclosure further comprises component (C), the content of component (C) is not particularly limited, and may be 70 to 300 parts by mass, or 80 to 200 parts by mass, relative to 100 parts by mass of the content of component (A). When the composition of the present disclosure comprises components (A) to (D), the content of component (C) may be 35 to 60 parts by mass, 40 to 55 parts by mass, or 42 to 50 parts by mass, relative to 100 parts by mass of the total amount of components (A) to (D).

[0042] (1.4) Component (D) The composition of the present disclosure may further contain component (D) in addition to components (A) and (B). When the composition of the present disclosure further contains component (D), the adhesion of the cured product of the present disclosure to a polyimide substrate is improved. Component (D): monofunctional (meth)acrylate having an amide group

[0043] Examples of the component (D) include N-alkyl(meth)acrylamides such as N-methyl(meth)acrylamide, N-n-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-n-butyl(meth)acrylamide, N-sec-butyl(meth)acrylamide, N-t-butyl(meth)acrylamide, and N-n-hexyl(meth)acrylamide; N-aromatic group-containing alkyl(meth)acrylamides such as N-benzyl(meth)acrylamide; N-hydroxyalkyl(meth)acrylamides such as N-hydroxyethyl(meth)acrylamide; N,N-dialkylaminodialkyl(meth)acrylamides such as N,N-dimethylaminoethyl(meth)acrylamide and N,N-dimethylaminopropyl(meth)acrylamide; Examples of the component (D) include N,N-dialkyl(meth)acrylamides such as N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-di-n-propyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, N,N-di-n-butyl(meth)acrylamide, and N,N-dihexyl(meth)acrylamide; N,N-diaromatic group-containing alkyl(meth)acrylamides such as N,N-dibenzyl(meth)acrylamide; and (meth)acryloylmorpholine. The component (D) may be used singly or in combination of two or more.

[0044] The content of component (D) is not particularly limited, and may be 0 to 50 parts by mass, or 2 to 45 parts by mass, relative to 100 parts by mass of the content of component (A). The content of component (D) may be 0 to 10 parts by mass, or 1 to 9 parts by mass, or 1.5 to 8 parts by mass, relative to 100 parts by mass of the total amount of components (A) to (D).

[0045] (1.5) Photopolymerization Initiator In addition to the component (A) and the component (B), the composition of the present disclosure may further contain a photopolymerization initiator, if necessary.

[0046] Examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2,2-dimethoxy-1,2-diphenylethan-1-one, bis(2,4, Examples of the photopolymerization initiator include bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, bis(2,6-dimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium. The photopolymerization initiator may be used alone or in combination of two or more.

[0047] When the composition of the present disclosure further contains a photopolymerization initiator, the content of the photopolymerization initiator is not particularly limited and may be 1 part by mass to 15 parts by mass, or may be 5 parts by mass to 10 parts by mass, relative to 100 parts by mass of the content of component (A). When the composition of the present disclosure contains components (A) to (D), the content of the photopolymerization initiator may be 0.01 parts by mass to 10 parts by mass, or may be 0.2 parts by mass to 5 parts by mass, relative to 100 parts by mass of the total amount of components (A) to (D).

[0048] (1.6) Other Components The composition of the present disclosure may further contain other components, in addition to the component (A) and the component (B), as necessary.

[0049] Examples of other components include a silane coupling agent, a photopolymerizable compound different from components (A) to (D), a polymerization inhibitor, an antioxidant, a defoaming agent, a leveling agent, an ultraviolet absorber, and a pigment.

[0050] (1.6.1) Silane Coupling Agent By including a silane coupling agent in the composition of the present disclosure, the adhesive performance of the cured product of the present disclosure to polyimide is improved.

[0051] The silane coupling agent is preferably a silane compound having an unsaturated double bond. Examples of the silane compound having an unsaturated double bond include vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane. The silane coupling agent may be used alone or in combination of two or more.

[0052] When the composition of the present disclosure further contains a silane coupling agent, the content of the silane coupling agent is not particularly limited and may be 1 to 15 parts by mass, or 5 to 10 parts by mass, relative to 100 parts by mass of the content of component (A).When the composition of the present disclosure contains components (A) to (D), the content of the silane coupling agent may be 10 parts by mass or less, or 0.1 to 5 parts by mass, relative to 100 parts by mass of the total amount of components (A) to (D).

[0053] (1.6.2) Photopolymerizable Compound Examples of photopolymerizable compounds include styrene, vinyl toluene, vinyl acetate, N-vinyl pyrrolidone, N-vinyl formamide, N-vinyl caprolactam, cyclohexyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, n-hexyl (meth)acrylate, phenoxyethyl (meth)acrylate, and diethylene glycol diacrylate. The photopolymerizable compounds may be used alone or in combination of two or more.

[0054] (1.6.3) Polymerization inhibitor Examples of polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, benzoquinone, p-t-butylcatechol, 2,6-di-t-butyl-4-methylphenol, etc. The polymerization inhibitors may be used alone or in combination of two or more.

[0055] (1.7) Preferred Aspects In the present disclosure, it is preferable that condition (2) be further satisfied. "Condition (2)" indicates that the composition of the present disclosure further contains a (C) component, and may further contain a (D) component, and that, relative to 100 parts by mass of the total amount of the (A), (B), (C), and (D) components, the content of the (A) component is 20 to 50 parts by mass, the content of the (B) component is 10 to 30 parts by mass, the content of the (C) component is 35 to 60 parts by mass, and the content of the (D) component is 0 to 10 parts by mass. By satisfying condition (2), the composition of the present disclosure can give a cured product that is superior in adhesion performance to polyimide substrates and electrical insulation performance after long-term exposure to high temperatures and humidity.

[0056] In the present disclosure, it is preferable that condition (3) be further satisfied in addition to condition (2). "Condition (3)" indicates that the weight-average molecular weight (Mw) of the urethane (meth)acrylate polymer of component (A) is 30,000 or more. When condition (3) is further satisfied, the composition of the present disclosure can provide a cured product with more excellent adhesion performance to polyimide substrates than when the weight-average molecular weight (Mw) of the urethane (meth)acrylate polymer of component (A) is not 30,000 or more.

[0057] In the present disclosure, in addition to conditions (2) and (3), it is preferable that condition (4) be further satisfied. "Condition (4)" indicates that the monofunctional (meth)acrylate of component (B) has at least one of an imide group and a hydroxyl group. When condition (4) is further satisfied, the composition of the present disclosure can give a cured product with superior adhesion performance to polyimide substrates compared to when the monofunctional (meth)acrylate of component (B) has a 1,3-dioxolane ring.

[0058] In the present disclosure, in addition to conditions (2) to (4), it is preferable that condition (5) be further satisfied. "Condition (5)" indicates that the monofunctional (meth)acrylate of component (B) has an imide group and at least one of a hydroxyl group and a phenoxy group. When condition (5) is further satisfied, the composition of the present disclosure can provide a cured product with lower water absorption than when the monofunctional (meth)acrylate of component (B) has only hydroxyl groups as reactive groups.

[0059] In the present disclosure, it is preferable that condition (6) be further satisfied in addition to conditions (2) to (5). "Condition (6)" indicates that the urethane (meth)acrylate polymer of component (A) is a polymer obtained by adding a hydroxyalkyl (meth)acrylate having an alkyl group containing 3 to 6 carbon atoms to a urethane prepolymer having an isocyanate group and a hydrogenated polybutadiene skeleton. When condition (6) is further satisfied, the composition of the present disclosure can give a cured product with even better adhesion performance to polyimide substrates.

[0060] In the present disclosure, it is preferable that condition (7) be further satisfied in addition to conditions (2) to (6). "Condition (7)" indicates that the active energy ray-curable composition further contains component (D), and the content of component (D) is 1 part by mass to 5 parts by mass per 100 parts by mass of the total amount. When condition (7) is further satisfied, the composition of the present disclosure can give a cured product that has more excellent adhesion performance to polyimide substrates than when the active energy ray-curable composition does not contain component (D).

[0061] (2) Cured Product The cured product of the present disclosure is obtained by curing the composition of the present disclosure. For example, the cured product of the present disclosure can be obtained by irradiating the composition of the present disclosure with active energy rays.

[0062] Because the cured product of the present disclosure has the above-described configuration, the cured product has excellent adhesion to polyimide substrates and excellent electrical insulation performance after long-term exposure to high temperature and humidity.

[0063] The shape of the cured product of the present disclosure is not particularly limited and may be appropriately selected depending on the application of the curing agent, etc. Examples of the shape of the cured product of the present disclosure include regular shapes (e.g., plate-like, sheet-like, rod-like, spherical, fibrous, powder-like, lens-like, etc.) and irregular shapes, etc. Applications of the cured product include, for example, electronic material-related components (e.g., insulating coating materials for printed wiring boards, potting materials, etc.).

[0064] (3) Electronic Component The electronic component of the present disclosure includes the cured product of the present disclosure and a polyimide substrate on which the cured product of the present disclosure is formed.

[0065] Because the electronic component of the present disclosure has the above-described configuration, the cured product is less likely to peel off from the polyimide substrate, and the electronic component has excellent electrical insulation performance even after being exposed to high temperature and humidity for a long period of time.

[0066] Examples of polyimide substrates include printed wiring boards.

[0067] (4) Method for Producing a Cured Product The method for producing a cured product of the present disclosure includes irradiating the composition of the present disclosure with active energy rays from a light-emitting diode (hereinafter also referred to as "LED") to cure the active energy ray-curable composition (hereinafter also referred to as "LED irradiation step").

[0068] The method for producing a cured product according to the present disclosure has the above-described configuration, and therefore can produce a cured product that has excellent adhesion to polyimide substrates and excellent electrical insulation properties even after long-term exposure to high temperatures and humidity.

[0069] The method for producing a cured product according to the present disclosure may further include a known step (e.g., a step of applying the active energy ray-curable composition to a substrate) in addition to the LED irradiation step, as necessary.

[0070] (4.1) LED Irradiation Step In the LED irradiation step, the active energy ray-curable composition of the present disclosure is irradiated with an LED to cure the active energy ray-curable composition.

[0071] The emission peak wavelength of the LED is appropriately selected depending on the material of the active energy ray-curable composition of the present disclosure, and may be 300 nm to 450 nm, or 350 nm to 400 nm. The illuminance of the LED is not particularly limited, and is not limited to 100 mW / cm. ２ ~400mW / cm ２ or 200 mW / cm ２ ~300mW / cm ２ The irradiation energy of the LED is not particularly limited, and may be 100 mJ / cm ２ ~5000mJ / cm ２ or 500 mJ / cm ２ ~2000mJ / cm ２ may be.

[0072] The LED light source may be used alone or in combination of two or more types.

[0073] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to the following examples as long as it does not deviate from the gist of the disclosure. In the following description, unless otherwise specified, all "parts" and "%" are by mass.

[0074] [1] Preparation of Component (A) [1.1] Component (A-1) (Production Example 1) A 300 mL flask equipped with a stirrer, a thermometer, and a pipe for oxygen / nitrogen mixed gas with an oxygen concentration of 5% by volume (hereinafter also referred to as "5% ON") was prepared. 9.14 g (0.041 mol) of isophorone diisocyanate ("VESTANAT IPDI" manufactured by Evonik Japan Co., Ltd.) (hereinafter also referred to as "IPDI") was added to the flask, and 0.039 g (1.78 × 10 mol) of 2,6-di-t-butyl-4-methylphenol ("ANTAGE BHT" manufactured by Kawaguchi Chemical Industry Co., Ltd.) (hereinafter referred to as "BHT") was added. －４mol) was added, and 88.8 g (0.43 mol) of isobornyl acrylate ("IBXA" manufactured by Osaka Organic Chemical Industry Co., Ltd.) (hereinafter also referred to as "IBXA") used as a diluent was added. While blowing in 5% ON, the contents were stirred to maintain the internal temperature at 70°C, and 0.12 g (1.13 × 10 as Nursem) of a 0.3 mass% IBXA diluted solution of iron tris(acetylacetonate) ("Nursem (registered trademark) Ferric" manufactured by Nippon Chemical Industry Co., Ltd.) (hereinafter referred to as "Nursem") was added. －６ mol) was added. Then, hydrogenated polybutadiene diol ("GI-2000" manufactured by Nippon Soda Co., Ltd.) having a hydroxyl value of 47.0 mgKOH / g was gradually added, and finally 78.6 g (0.033 mol) was added. Thereafter, while maintaining the temperature inside the flask at 70°C, 0.12 g (1.13 × 10 as Nursem) of a 0.3 mass % IBXA diluted solution was added. －６ mol) was added, and 0.37 g (0.004 mol) of 1,4-butanediol ("1,4-butanediol" manufactured by Mitsubishi Chemical Corporation) was added. Thereafter, the temperature was raised at a rate of 5°C / min, with the upper limit of the liquid temperature being 98°C. When the Mw of the contents exceeded 23,000 as measured by GPC (based on standard polystyrene; the same applies hereinafter and description will be omitted), 1.73 g (0.015 mol) of 2-hydroxyethyl acrylate ("HEA" manufactured by Toagosei Co., Ltd.) (hereinafter also referred to as "2-HEA") was added. At this time, 0.24 g (2.26 × 10 －６ mol) was added again. Subsequent IR measurement confirmed that the isocyanate groups had disappeared, and the synthesis was terminated. The resulting reaction mixture contained 50% by mass of a urethane acrylate polymer (hereinafter also referred to as "A-1") and 50% by mass of IBXA. Measurement of the molecular weight of component (A-1) by GPC revealed that Mw was 27,000.

[0075] [1.2] Component (A-2) (Production Example 2) A 1 L flask equipped with a stirrer, a thermometer, and a 5% ON piping was prepared. 54.01 g (0.24 mol) of IPDI was added to the flask, and 0.18 g (8.35 × 10 －４mol) was added, and 368.01 g (1.77 mol) of IBXA used as a diluent was added. The contents were stirred while blowing in 5% ON, and the internal temperature was maintained at 55°C. 0.48 g (5.21 x 10 as Nursem) of a 0.3 mass% IBXA diluted solution was added. －６ mol) was added. Then, hydrogenated polybutadiene diol ("GI-1000" manufactured by Nippon Soda Co., Ltd.) having a hydroxyl value of 69.4 mgKOH / g was gradually added, and finally 314.01 g (0.19 mol) was added. Thereafter, while maintaining the temperature inside the flask at 60°C, 0.48 g (5.21 × 10 as Nursem) of a 0.3 mass % IBXA diluted solution was added. －６ mol) and 2.20 g (0.024 mol) of 1,4-butanediol were added. Thereafter, the temperature was raised at a rate of 5°C / min with an upper limit of 98°C. When the liquid temperature reached 85°C, 0.48 g (5.21 x 10 as Nursem) of a 0.3 mass% IBXA diluted solution was added as an additional catalyst. －６ mol) was added. When the Mw of the contents exceeded 32,000 by GPC, 10.21 g (0.088 mol) of 2-HEA was added. At this time, 0.96 g (1.04 × 10 －５ mol) was added again. Subsequent IR measurement confirmed that the isocyanate groups had disappeared, and the synthesis was terminated. The resulting reaction mixture contained 50% by mass of a urethane acrylate polymer (hereinafter also referred to as "A-2") and 50% by mass of IBXA. Measurement of the molecular weight of component (A-2) by GPC revealed that Mw was 40,000.

[0076] [1.3] Component (A-3) (Production Example 3) A 1 L flask equipped with a stirrer, a thermometer, and a 5% ON piping was prepared. 54.01 g (0.24 mol) of IPDI was added to the flask, and 0.18 g (8.35 × 10 －４ mol) was added, and 376.00 g (1.81 mol) of IBXA used as a diluent was added. The contents were stirred while blowing in 5% ON, and the internal temperature was maintained at 70°C. 0.60 g (5.66 x 10 as Nursem) of a 0.3 mass% IBXA diluted solution was added. －６mol) was added. Then, hydrogenated polybutadiene diol ("GI-1000" manufactured by Nippon Soda Co., Ltd.) having a hydroxyl value of 64.3 mgKOH / g was gradually added, and finally 338.10 g (0.19 mol) was added. Thereafter, while maintaining the temperature inside the flask at 70°C, 0.60 g (5.66 × 10 as Nursem) of a 0.3 mass % IBXA diluted solution was added. －６ mol) was added, and 2.20 g (0.024 mol) of 1,4-butanediol was added. Thereafter, the temperature was raised at a rate of 5°C / min, with an upper limit of 98°C. When the Mw of the contents exceeded 32,000 as measured by molecular weight by GPC, 12.68 g (0.088 mol) of 4-hydroxybutyl acrylate ("4-HBA" manufactured by Osaka Organic Chemical Industry Ltd.) (hereinafter also referred to as "4-HBA") was added. At this time, 1.2 g (1.13 × 10) of Nursem solution was also added. －５ mol) was added again. Subsequent IR measurement confirmed that the isocyanate groups had disappeared, and the synthesis was terminated. The resulting reaction mixture contained 50% by mass of urethane acrylate polymer (hereinafter also referred to as "A-3") and 50% by mass of IBXA. Measurement of the molecular weight of component (A-3) by GPC revealed that Mw was 40,000.

[0077] [1.4] Component (A'-1) A hydrogenated polybutadiene oligomer ("TEAI-1000" manufactured by Nippon Soda Co., Ltd., number average molecular weight: 2,000, Mw<10,000) (hereinafter also referred to as "TEAI-1000") was prepared as component (A'-1).

[0078] [1.5] Component (A'-2) (Production Example 4) A 1 L flask equipped with a stirrer, a thermometer, and a 5% ON piping was prepared. 19.20 g (0.086 mol) of IPDI was added to the flask, and 0.0823 g (3.73 × 10 －４mol) was added, and 69.72 g (0.22 mol) of nonylphenol EO-modified acrylate ("Aronix (registered trademark) M-111" manufactured by Toagosei Co., Ltd.) (hereinafter also referred to as "M-111") used as a diluent was added. The contents were stirred while blowing in 5% ON, and the internal temperature was maintained at 73°C. 0.25 g (2.33 x 10 as Nursem) of a 0.3 mass% diluted solution of Nursem in lauryl acrylate (LA manufactured by Osaka Organic Chemical Industry Co., Ltd., hereinafter referred to as LA) was added. －６ mol) was added. Then, polyester diol with a hydroxyl value of 56.2 mgKOH / g was gradually added, and finally 137.56 g (0.069 mol) was added. The polyester diol was composed of neopentyl glycol and adipic acid. Then, 0.25 g (2.33 × 10 as Nursem) of a 0.3 mass % LA diluted solution was added. －６ mol) was added, and 0.78 g (0.009 mol) of 1,4-butanediol was added, and the temperature inside the flask was raised to 80°C. Thereafter, the temperature was raised at a rate of 5°C / min with the upper limit of the liquid temperature being 98°C. To add the catalyst, 0.25 g (2.33 x 10 as Nursem) of a 0.3 mass% LA diluted solution was added. －６ When the Mw of the contents exceeded 32,000 as determined by GPC molecular weight measurement, 3.63 g (0.031 mol) of 2-HEA was added again, and 0.51 g (4.66 × 10 mol) of the Nursem solution was also added. －６ mol) was added again. Furthermore, 30.80 g (0.13 mol) of LA was added. Subsequent IR measurement confirmed that the isocyanate groups had disappeared, and the synthesis was terminated. After completion of the synthesis, 46.62 g (0.19 mol) of LA was added for further dilution. The resulting reaction mixture contained 52.5 parts of urethane acrylate polymer (hereinafter also referred to as "A'-2"), 22.5 parts of M-111, and 25.4 parts of LA. Measurement of the molecular weight of component (A'-2) by GPC revealed that Mw was 40,000.

[0079] [2] Examples 1 to 14 and Comparative Examples 1 to 4 [2.1] Example 1 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 1 (35 parts of A-1 + 35 parts of IBXA), 20 parts of N-acryloyloxyethylhexahydrophthalimide ("Aronix (registered trademark) M-140" manufactured by Toagosei Co., Ltd.) (hereinafter also referred to as "M-140"), 10 parts of LA, 3 parts of a photopolymerization initiator ("Omnirad 184D" manufactured by IGM Resins) (hereinafter also referred to as "photopolymerization initiator Omnirad 184D"), and 3 parts of a silane coupling agent ("KBM-503" manufactured by Shin-Etsu Chemical Co., Ltd.) (hereinafter also referred to as "KBM-503") and mixing them uniformly. The obtained photocurable composition was used to evaluate according to Evaluations 1 to 4.

[0080] [2.2] Example 2 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 1 (35 parts of A-1 + 35 parts of IBXA), 20 parts of 2-hydroxy-3-phenoxypropyl acrylate ("Aronix (registered trademark) M-5700" manufactured by Toagosei Co., Ltd.) (hereinafter also referred to as "M-5700"), 10 parts of LA, 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0081] [2.3] Example 3 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 2 (35 parts of A-2 + 35 parts of IBXA), 20 parts of M-140, 10 parts of LA, 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0082] [2.4] Example 4 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 2 (35 parts of A-2 + 35 parts of IBXA), 20 parts of M-5700, 10 parts of LA, 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0083] [2.5] Example 5 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 2 (35 parts of A-2 + 35 parts of IBXA), 20 parts of (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate (MEDOL-10 manufactured by Osaka Organic Chemical Industry Ltd. (hereinafter also referred to as "MEDOL-10"), 10 parts of LA, 3 parts of photopolymerization initiator Omnirad 184D, and 3 parts of silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0084] [2.6] Example 6 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 2 (35 parts of A-2 + 35 parts of IBXA), 18 parts of M-140, 10 parts of LA, 2 parts of N-hydroxyethyl acrylamide ("HEAA" manufactured by KJ Chemicals Co., Ltd.) (hereinafter also referred to as "HEAA"), 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0085] [2.7] Example 7 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 2 (35 parts of A-2 + 35 parts of IBXA), 18 parts of M-5700, 10 parts of NOAA ("NOAA" manufactured by Osaka Organic Chemical Industry Ltd.) (hereinafter also referred to as "NOAA"), 2 parts of HEAA, 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0086] [2.8] Example 8 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 3 (35 parts of A-3 + 35 parts of IBXA), 18 parts of M-140, 10 parts of LA, 2 parts of HEAA, 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0087] [2.9] Example 9 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 3 (35 parts of A-3 + 35 parts of IBXA), 20 parts of M-140, 10 parts of NOAA, 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0088] [2.10] Example 10 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 3 (35 parts of A-3 + 35 parts of IBXA), 20 parts of M-5700, 10 parts of NOAA, 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0089] [2.11] Example 11 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 3 (35 parts of A-3 + 35 parts of IBXA), 18 parts of M-140, 10 parts of NOAA, 2 parts of HEAA, 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0090] [2.12] Example 12 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 3 (35 parts of A-3 + 35 parts of IBXA), 18 parts of M-5700, 10 parts of NOAA, 2 parts of HEAA, 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0091] [2.13] Example 13 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 1 (35 parts of A-1 + 35 parts of IBXA), 20 parts of 4-HBA, 10 parts of LA, 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0092] [2.14] Example 14 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 2 (35 parts of A-2 + 35 parts of IBXA), 20 parts of 4-HBA, 10 parts of LA, 3 parts of the photopolymerization initiator Omnirad-184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0093] [2.15] Comparative Example 1 A photocurable composition was produced by blending 70 parts of the reaction mixture obtained in Production Example 1 (35 parts of A-1 + 35 parts of IBXA), 20 parts of phenol EO-modified acrylate ("Aronix (registered trademark) M-101A" manufactured by Toagosei Co., Ltd.) (hereinafter also referred to as "M-101A"), 10 parts of LA, 3 parts of photopolymerization initiator Omnirad 184D, and 3 parts of silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0094] [2.16] Comparative Example 2 A photocurable composition was produced by blending 35 parts of hydrogenated polybutadiene oligomer (A'-1), 20 parts of M-140, 17 parts of LA, 13 parts of IBXA, 15 parts of M-111, 3 parts of photopolymerization initiator Omnirad 184D, and 3 parts of KBM-503 and mixing them uniformly. The resulting composition was evaluated according to Evaluations 1 to 4.

[0095] [2.17] Comparative Example 3 A photocurable composition was produced by blending 35 parts of hydrogenated polybutadiene oligomer (A'-1), 20 parts of M-5700, 17 parts of LA, 13 parts of IBXA, 15 parts of M-111, 3 parts of photopolymerization initiator Omnirad 184D, and 3 parts of KBM-503 and mixing them uniformly. The resulting composition was evaluated according to Evaluations 1 to 4.

[0096] [2.18] Comparative Example 4 A photocurable composition was produced by blending 67 parts of the reaction mixture obtained in Production Example 4 (35 parts of A'-2 + 15 parts of M-111 + 17 parts of LA), 20 parts of acryloylmorpholine ("ACMO" manufactured by KJ Chemicals Corporation) (hereinafter also referred to as "ACMO"), 13 parts of IBXA, 3 parts of the photopolymerization initiator Omnirad 184D, and 3 parts of the silane coupling agent KBM-503, and mixing them uniformly. The obtained photocurable composition was evaluated according to Evaluations 1 to 4.

[0097] [3] Evaluation Method [3.1] Peel Strength from Polyimide Substrate A polyimide film ("Kapton (registered trademark) 100H" manufactured by Toray DuPont Co., Ltd.) was prepared as a polyimide substrate. The obtained composition was applied to a thickness of 2 mm on the polyimide film, and the applied composition was covered with a surface-treated PET film. An LED was irradiated onto the composition from the surface-treated PET film side to obtain a cured product. The illuminance of the LED was 500 mW / cm. ２ The LED irradiation energy was 4,000 mJ / cm ２ A support plate was attached to the surface-treated PET film side using adhesive tape. This gave an evaluation sample. Using this evaluation sample, the 180° peel strength was measured using an Instron tabletop testing system (5564). The fracture interface was the interface between the cured product and the polyimide film. The measurement conditions were a pulling speed of 50 mm / min and room temperature. The acceptable range of peel strength was 5 Ncm or more.

[0098] [3.2] Water Absorption The obtained composition was applied to a thickness of 1 mm on a cycloolefin polymer film ("ZEONORFILM" manufactured by ZEON Corporation) (hereinafter also referred to as "ZEONORFILM"), and then covered with the same film. An LED was irradiated from above the film to obtain a cured product (evaluation sample). The LED's peak emission wavelength was 365 nm. The LED's illuminance was 500 mW / cm. ２ The LED irradiation energy was 4,000 mJ / cm ２The evaluation sample was placed in a dryer at 50±2° C. for 24 hours, and then immersed in pure water at 23° C. for 24 hours. The water absorption rate was calculated from the weight of the evaluation sample before and after immersion in water.

[0099] [3.3] Initial volume resistivity and volume resistivity after immersion in water The obtained composition was applied to a Zeonor film to a thickness of 0.2 mm, and then covered with the same film. An LED was irradiated from above the film to obtain a cured product (evaluation sample). The LED emission peak wavelength was 365 nm. The LED illuminance was 500 mW / cm. ２ The LED irradiation energy was 4,000 mJ / cm ２ Using this evaluation sample, the volume resistivity was measured when a voltage of 500 V was applied. Thereafter, the sample was immersed in pure water at 23° C. for 24 hours, and then the volume resistivity was measured again.

[0100] [3.4] Resistance after long-term high-temperature, high-humidity test The obtained composition was applied to a thickness of 1 mm on a glass substrate with interdigitated silver electrodes (electrode width: 100 μm, pitch: 100 μm), and then covered with a Zeonor film. An LED was irradiated from above the film to obtain a cured product (evaluation sample). The LED emission peak wavelength was 365 nm. The LED illuminance was 500 mW / cm. ２ The LED irradiation energy was 4,000 mJ / cm ２ The evaluation sample obtained by the above method was subjected to a long-term high temperature and high humidity test. In the long-term high temperature and high humidity test, a voltage of 15 V was continuously applied to the evaluation sample for 1000 hours at a temperature of 85°C and a humidity of 85% RH. The resistance of the evaluation sample after the long-term high temperature and high humidity test was measured. The allowable range of the resistance value after the long-term high temperature and high humidity test was 10 ９ It is over Omega.

[0101]

[0102]

[0103]

[0104] In Tables 1 to 3, "PB" represents polybutadiene. "PE" represents polyether. The blank spaces (A) to (E) in Tables 1 to 3 represent 0 parts by mass.

[0105] [4] Results The composition of Comparative Example 1 did not contain component (B). The compositions of Comparative Examples 2 to 4 did not contain component (A). Therefore, the peel strength of Comparative Examples 1 to 3 was not 5 N / cm or more. The resistance value of Comparative Example 4 after the long-term high-temperature, high-humidity test was 10 ９ As a result, it was found that the compositions of Comparative Examples 1 to 4 were not "active energy ray-curable compositions capable of giving cured products excellent in adhesive performance to polyimide substrates and in electrical insulating performance after long-term exposure to high temperature and high humidity."

[0106] The compositions of Examples 1 to 13 contained the component (A) and the component (B). Therefore, the peel strength of Examples 1 to 13 was 5 N / cm or more. The resistance values ​​of Examples 1 to 13 after the long-term high-temperature high-humidity test were 10 ９ As a result, it was found that the compositions of Examples 1 to 13 were "active energy ray-curable compositions capable of giving cured products that have excellent adhesive properties to polyimide substrates and excellent electrical insulating properties after long-term exposure to high temperature and humidity."

[0107] In Comparative Example 4, 20 parts of highly polar ACMO were blended as a monofunctional acrylate with a polyester-based urethane acrylate polymer (A'-2). The polyester-based urethane acrylate polymer hydrolyzes under long-term high-temperature, high-humidity testing to generate carboxylic acid. The generation of carboxylic acid hydrophilizes the resin, resulting in a decrease in electrical insulation performance. This is believed to be the reason for the low resistance value after the long-term high-temperature, high-humidity testing. ACMO, which contributes to improving the peel strength against polyimide, is water-soluble and increases the resin's water absorption rate (1.5%). As a result, the volume resistivity decreases both initially and after immersion in water.

[0108] Other than Comparative Example 4, urethane acrylate polymers having a non-polyester hydrogenated polybutadiene skeleton were investigated. The hydrogenated polybutadiene skeleton is hydrophobic and can suppress hydrolysis of the resin, so a high resistance value could be maintained even after a long-term high-temperature, high-humidity test (improved water resistance).

[0109] As a replacement for ACMO, water-insoluble M-140 (containing an imide group), M-5700 (containing a hydroxyl group), or MEDOL-10 (containing 1,3-dioxolane) was blended. The blending of water-insoluble monomers achieved low water absorption while maintaining the polyimide peel strength. As a result, the volume resistivity was improved both initially and after immersion in water compared to Comparative Example 4. The improved peel strength is presumed to be due to the cohesive force between the imide group and the polyimide of the substrate, and hydrogen bonding between the hydroxyl group and the imide group of the substrate or moisture on the substrate surface.

[0110] Although it is water-insoluble, the aromatic acrylate monomer M-101A did not contribute to improving the peel strength to polyimide (Comparative Example 1).

[0111] When water-soluble 4-HBA (containing a hydroxyl group) was added, the peel strength to the polyimide substrate improved, but the volume resistivity after immersion in water decreased due to an increase in water absorption (Examples 12 and 13).

[0112] When a hydrogenated polybutadiene oligomer having a low molecular weight was used, the peel strength to the polyimide substrate decreased (Comparative Examples 2 and 3).

[0113] The addition of a small amount of HEAA further improved the peel strength to the polyimide substrate. It is presumed that the improved adhesion was due to hydrogen bonding between the hydroxyl groups of HEAA and the polyimide.

[0114] Comparing Examples 3 to 7 (urethane acrylate is component A-2) with Examples 8 to 12 (urethane acrylate is component A-3), the latter have improved peel strength to polyimide substrates and are therefore more preferable.

[0115] The disclosure of Japanese Patent Application No. 2024-096659, filed on June 14, 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. An active energy ray-curable composition comprising the following components (A) and (B): Component (A): a urethane (meth)acrylate polymer having a weight-average molecular weight of 20,000 or more and having a hydrogenated polybutadiene skeleton; and Component (B): a water-insoluble monofunctional (meth)acrylate having at least one of an imide group, a hydroxyl group, and a 1,3-dioxolane ring, but no amide group.

2. The active energy ray-curable composition according to claim 1, further comprising the following component (C): and optionally further comprising the following component (D): wherein, relative to 100 parts by mass of the total of the components (A), (B), (C), and (D), the content of component (A) is 20 to 50 parts by mass, the content of component (B) is 10 to 30 parts by mass, the content of component (C) is 35 to 60 parts by mass, and the content of component (D) is 0 to 10 parts by mass. Component (C): a monofunctional (meth)acrylate having an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and having no imide group, hydroxyl group, 1,3-dioxolane ring, or amide group; and Component (D): a monofunctional (meth)acrylate having an amide group.

3. The active energy ray-curable composition according to claim 2, wherein the weight average molecular weight of the urethane (meth)acrylate polymer of component (A) is 30,000 or more.

4. The active energy ray-curable composition according to claim 3, wherein the monofunctional (meth)acrylate of component (B) has at least one of an imide group and a hydroxyl group.

5. The active energy ray-curable composition according to claim 4, wherein the monofunctional (meth)acrylate of component (B) has an imide group and at least one of a hydroxyl group and a phenoxy group.

6. The active energy ray-curable composition according to claim 5, wherein the urethane (meth)acrylate polymer of component (A) is a polymer obtained by adding a hydroxyalkyl (meth)acrylate having an alkyl group containing 3 to 6 carbon atoms to a urethane prepolymer having an isocyanate group and a hydrogenated polybutadiene skeleton.

7. The active energy ray-curable composition according to claim 6, further comprising component (D), wherein the content of component (D) is 1 to 5 parts by mass per 100 parts by mass of the total amount.

8. A cured product obtained by curing the active energy ray-curable composition according to any one of claims 1 to 7.

9. An electronic component comprising the cured product according to claim 8 and a substrate on which the cured product is formed.

10. A method for producing a cured product, comprising irradiating the active energy ray-curable composition according to any one of claims 1 to 7 with active energy rays from a light-emitting diode to cure the active energy ray-curable composition.

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