CURABLE COMPOSITION, CURED PRODUCT THEREOF, AND ELECTRONIC COMPONENT HAVING CURED PRODUCT THEREOF

Abstract

To provide: a curable composition capable of obtaining a transparent or translucent cured product which is uncolored or almost uncolored; its cured product; and an electronic component having the cured product.SOLUTION: There is provided a curable composition which comprises (A) a compound having a (meth)acryloyl group, (B) a photopolymerization initiator, (C) a thermosetting component and (D) a polymerization inhibitor, wherein the photopolymerization initiator (B) includes an oxime ester-based photopolymerization initiator and the polymerization inhibitor (D) is at least one or more of compounds having a specific condensed polycyclic aromatic skeleton and has a viscosity at 50°C of 15 mPa s or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable composition, a cured product thereof, and an electronic component having the cured product. In particular, the present invention relates to a curable composition capable of obtaining a cured product that is transparent or translucent and not colored or almost not colored, the cured product (particularly, a transparent protective film), and an electronic component having the cured product.

Background Art

[0002] Conventionally, a low-viscosity photocurable composition has been used to form a solder resist on a printed wiring board used in electronic devices or the like by an inkjet printing method.

[0003] In this photocurable composition, a polymerization inhibitor is usually blended in order to suppress an increase in viscosity due to easily reactive groups such as (meth)acrylic groups during storage or production. As the polymerization inhibitor, for example, Patent Document 1 discloses a polymerization inhibitor capable of efficiently suppressing the polymerization of an easily polymerizable compound, represented by the following general formula (1):

Chemical Formula

[0004] On the other hand, in the photocurable composition, colorants such as black, green, or white are blended according to the conventional manufacturing convenience, performance reasons, and user needs for the solder resist as the cured product. In recent years, due to reasons such as diversification of design, in addition to the colored solder resist, the need for a transparent or translucent protective film that is not colored or almost not colored has also been increasing.

[0005] In this regard, Patent Document 1 describes that since the above polymerization inhibitor stably exists during storage and use, it can effectively prevent polymerization without causing coloring of the object (for example, resist, paint, coating).

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, Patent Document 1 does not specifically disclose a composition for obtaining a cured product (particularly, a transparent protective film) that is suitable for inkjet printing and is transparent to translucent with controlled coloring property even after curing.

[0008] An object of the present invention made in view of the above problems is to provide a low-viscosity curable composition capable of obtaining a cured product that is transparent to translucent and not colored or almost not colored, a cured product of the curable composition, and an electronic component having the cured product.

Means for Solving the Problems

[0009] As a result of intensive studies, the present inventor found that although it was difficult to solve the above problems by simply selecting a polymerization inhibitor, the above object can be achieved by a combination of at least one polymerization inhibitor among oxime ester-based photoinitiators and compounds having a specific condensed polycyclic aromatic skeleton, and thus completed the present invention.

[0010] That is, the above object is achieved by the present invention (A) A compound having a (meth)acryloyl group, (B) A photoinitiator, (C) A thermosetting component, and (D) A polymerization inhibitor, and the (B) photoinitiator contains an oxime ester-based photoinitiator, the (D) polymerization inhibitor is represented by the following general formula (1):

Chemical formula

[0011] According to a preferred embodiment of the curable composition of the present invention, the (B) photoinitiator further contains an acylphosphine-based photoinitiator.

[0012] According to another preferred embodiment of the curable composition of the present invention, it further contains (E) a flame retardant.

[0013] According to still another preferred embodiment of the curable composition of the present invention, the content of the (E) flame retardant is 1 to 50 parts by mass with respect to 100 parts by mass of the compound having a (meth)acryloyl group (A).

[0014] According to still another preferred embodiment of the curable composition of the present invention, the (E) flame retardant contains phenoxyphosphazene.

[0015] According to still another preferred embodiment of the curable composition of the present invention, the content of the (D) polymerization inhibitor is 1 part by mass or less with respect to 100 parts by mass of the compound having a (meth)acryloyl group (A).

[0016] According to yet another preferred embodiment of the curable composition of the present invention, the (D) polymerization inhibitor is 1,4-dimethoxynaphthalene and / or 1,4-diethoxynaphthalene.

[0017] The cured product of the present invention is obtained by curing any of the above curable compositions, and the electronic component of the present invention contains this cured product.

Advantages of the Invention

[0018] According to the present invention, it is possible to provide a low-viscosity curable composition capable of obtaining a cured product (particularly, a transparent protective film) that is transparent to translucent and not colored or almost not colored, the cured product thereof, and an electronic component having the cured product.

Embodiments for Carrying Out the Invention

[0019] The curable composition of the present invention contains (A) a compound having a (meth)acryloyl group, (B) a photopolymerization initiator, (C) a thermosetting component, and (D) a polymerization inhibitor, and the (B) photopolymerization initiator contains an oxime ester-based photopolymerization initiator, and the (D) polymerization inhibitor is represented by the following general formula (1):

Chemical formula

[0020] In addition, by having the above-mentioned constituent, in addition to obtaining a cured product that is transparent or semi-transparent and not colored or almost not colored, it is also possible to obtain a curable composition having excellent storage stability, and a cured product having excellent processability when applying the cured product to a printed wiring board (for example, a cured product having excellent touch dryness (tackiness)) can also be obtained.

[0021] By further using a flame retardant (E) with respect to the above-mentioned constituent, warping of the cured product can also be suppressed.

[0022] Since the curable composition of the present invention has a low viscosity (that is, a viscosity of 15 mPa·s or less at 50°C), it is suitable for use in an inkjet printer. This viscosity is the value measured at 50°C, 100 rpm, and 30 seconds according to the "Viscosity Measurement Method by Cone-Plate Rotational Viscometer" in JIS Z8803:2011(10), using a cone plate type viscometer (TVE-33H, manufactured by Toki Sangyo Co., Ltd.) with 1°34’×R24 as the cone and rotor.

[0023] Hereinafter, the constituents of the curable composition of the present invention will be described.

[0024] [(A) Compound having a (meth)acryloyl group] (A) The compound having a (meth)acryloyl group means, for example, a compound having one or more (meth)acryloyl groups in its structure. By adjusting the content of the compound having a (meth)acryloyl group, the viscosity of the curable composition can be adjusted to a low viscosity (that is, a viscosity of 15 mPa·s or less at 50°C).

[0025] The total amount of the compound having a (meth)acryloyl group is preferably 60% by mass to 95% by mass, more preferably 65% by mass to 90% by mass, based on the total mass (100% by mass) of the curable composition.

[0026] Examples of the compound having a (meth)acryloyl group include a compound having a (meth)acryloyl group without a hydroxyl group and a compound having a (meth)acryloyl group with a hydroxyl group. The compound having a (meth)acryloyl group with a hydroxyl group is preferably used when a blocked isocyanate compound is used as the (C) thermosetting component.

[0027] Examples of the compound having a (meth)acryloyl group without a salicylic acid group include methyl α-(allyloxymethyl)acrylate, or diacrylates of diols such as 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, neopentyl glycol diacrylate, diacrylates of diols obtained by adding at least one of ethylene oxide and propylene oxide to neopentyl glycol, diacrylates of glycols such as neopentyl glycol caprolactone-modified hydroxypivalate diacrylate, EO adduct diacrylate of bisphenol A (ethoxylated bisphenol A diacrylate), PO adduct diacrylate of bisphenol A, dicyclopentadienyl diacrylate, dicyclopentadienyl diacrylate, cyclohexyl diacrylate, and other diacrylates having a cyclic structure, or bifunctional (meth)acrylates such as methacrylate monomers corresponding thereto, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolmethane triacrylate, ethylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified trimethylolpropane triacrylate, epichlorohydrin-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, tetramethylolmethane tetraacrylate, ethylene oxide-modified phosphate triacrylate, epichlorohydrin-modified glycerol triacrylate, dipentaerythritol hexaacrylate, or polyfunctional acrylates represented by their silsesquioxane-modified products, or methacrylate monomers corresponding thereto, trifunctional methacrylate esters,Examples of the polyfunctional (meth)acrylates include ε-caprolactone-modified tris(acryloxyethyl)isocyanurate. These can be used alone or in combination of two or more. Examples of commercially available products include A-BPE-4 (ethoxylated bisphenol A diacrylate) manufactured by Shin-Nakamura Chemical Co., Ltd.; AOMA (methyl α-(allyloxymethyl)acrylate) manufactured by Nippon Shokubai Co., Ltd.; and DPGDA (dipropylene glycol diacrylate) manufactured by Daicel-Ornex Co., Ltd.

[0028] Although the content of the compound having a (meth)acryloyl group without a hydroxyl group depends on the types and contents of other components, it is generally preferably 90% by mass to 99% by mass, more preferably 95% by mass to 99% by mass, based on the total mass (100% by mass) of the compound having a (meth)acryloyl group in the curable composition. By setting it within such a range, a curable composition having a viscosity within the range of 15 mPa·s or less at 50°C can be obtained.

[0029] The above-mentioned compound having a (meth)acryloyl group with a hydroxyl group cures together with the compound having a (meth)acryloyl group without a hydroxyl group in the photocuring stage, and then further reacts with the blocked isocyanate compound as a thermosetting component in the subsequent thermosetting stage to form a cured product. Thus, since the compound having a (meth)acryloyl group with a hydroxyl group finally reacts with an isocyanate group, it is sufficient if it has a structure having a hydroxyl group in the molecule, and the number of hydroxyl groups per molecule is not particularly limited. However, the number of hydroxyl groups is preferably such that the viscosity of the curable composition is suppressed to such an extent that ejection from the inkjet nozzle is smooth.

[0030] Examples of the compound having a (meth)acryloyl group having a hydroxyl group include a compound having a (meth)acryloyl group having a hydroxyl group with a molecular weight of 100 to 600 g / mol, such as 2-hydroxy-3-acryloyloxypropyl (meth)acrylate, 2-hydroxy-3-phenoxyethyl (meth)acrylate, 1,4-cyclohexanedimethanol mono (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, pentaerythritol tri (meth)acrylate, dipentaerythritol monohydroxypenta (meth)acrylate, and 2-hydroxypropyl (meth)acrylate. The compound having a (meth)acryloyl group having a hydroxyl group can be used alone or in combination of two or more. Examples of commercially available products include 4-HBA (4-hydroxybutyl acrylate) manufactured by Mitsubishi Chemical Corporation.

[0031] The content of the compound having a (meth)acryloyl group having a hydroxyl group depends on the types and contents of other components, but is generally preferably 1% by mass to 10% by mass, more preferably 1% by mass to 5% by mass, based on the total mass (100% by mass) of the compound having a (meth)acryloyl group in the curable composition. By setting it within such a range, good curability can be obtained.

[0032] [(B) Photoinitiator] (B) The photoinitiator contains an oxime ester-based photoinitiator. This oxime ester-based photoinitiator is a compound having at least one oxime ester group in the molecule.

[0033] Examples of the oxime ester-based photoinitiators include 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-butanedione, 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-pentanedione, 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-hexanedione, 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-heptanedione, 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione, 2-(O-benzoyloxime)-1-[4-(methylphenylthio)phenyl]-1,2-butanedione, 2-(O-benzoyloxime)-1-[4-(ethylphenylthio)phenyl]-1,2-butanedione, 2-(O-benzoyloxime)-1-[4-(butylphenylthio)phenyl]-1,2-butanedione, 1-(O-acetoxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone, 1-(O-acetoxime)-1-[9-methyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone, 1-(O-acetoxime)-1-[9-propyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone, 1-(O-acetoxime)-1-[9-ethyl-6-(2-ethylbenzoyl)-9H-carbazol-3-yl]ethanone, 1-(O-acetoxime)-1-[9-ethyl-6-(2-butylbenzoyl)-9H-carbazol-3-yl]ethanone, 2-(benzoyloximino)-1-[4-(phenylthio)phenyl]-1-octanone, 2-(acetoxyimino)-4-(4-chlorophenylthio)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-butanone.Examples of commercially available products include Irgacure OXE-01 (2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione) manufactured by BASF Japan Ltd.; Irgacure OXE-02 (1-(O-acetyloxime)-1-[9-methyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone); Irgacure OXE-03; Irgacure OXE-04; N-1919 manufactured by ADEKA Corporation, NCI-831, TR-PBG-304 manufactured by Changzhou Qiangli Electronic New Materials Co., Ltd., and TOE-04-A3 manufactured by Nippon Chemical Industry Co., Ltd.

[0034] In addition, a photopolymerization initiator having two oxime ester groups in the molecule can also be preferably used. Specifically, an oxime ester compound having a carbazole structure represented by the following general formula (I) can be mentioned: [Chemical formula] (In the formula, X represents a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a phenyl group, a phenyl group (which may have a substituent with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group or a dialkylamino group having an alkyl group having 1 to 8 carbon atoms), a naphthyl group (which may have a substituent with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group or a dialkylamino group having an alkyl group having 1 to 8 carbon atoms). Y and Z each represent a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a halogen group, a phenyl group, a phenyl group (which may have a substituent with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group or a dialkylamino group having an alkyl group having 1 to 8 carbon atoms), a naphthyl group (which may have a substituent with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group or a dialkylamino group having an alkyl group having 1 to 8 carbon atoms), an anthryl group, a pyridyl group, a benzofuryl group, or a benzothienyl group. Ar represents an alkylene, vinylene, phenylene, biphenylene, pyridylene, naphthylene, thiophene, anthrylene, thienylene, furylene, 2,5-pyrrole-diyl, 4,4'-stilbene-diyl, or 4,2'-styrene-diyl having 1 to 10 carbon atoms, and n is an integer of 0 or 1).

[0035] In particular, in the above formula, an oxime ester-based photopolymerization initiator in which X and Y are each a methyl group or an ethyl group, Z is methyl or phenyl, n is 0, and Ar is phenylene, naphthylene, thiophene, or thienylene is preferred.

[0036] The above specific compounds of the oxime ester-based photopolymerization initiator can be used alone or in combination of two or more.

[0037] The content of the oxime ester-based photopolymerization initiator is preferably 0.01 to 5 parts by mass, more preferably 0.01 to 2 parts by mass, based on 100 parts by mass of the compound having a (meth)acryloyl group in the curable composition.

[0038] (B) The photopolymerization initiator can further contain an acylphosphine-based photopolymerization initiator. By using this acylphosphine-based photopolymerization initiator, the tackiness after exposure can be further improved.

[0039] Examples of acylphosphine-based photoinitiators include bisacylphosphine oxide-based photoinitiators and monoacylphosphine oxide-based photoinitiators. Specifically, bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl-2,4,6-trimethylbenzoylphenylphosphinate, (2,6-dimethoxybenzoyl)-2,4,4-pentylphosphine oxide, etc. are mentioned. In particular, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide is preferred. These can be used alone or in combination of two or more. Examples of commercially available products include Omnirad TPO (diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide) manufactured by IGM Resins B.V.

[0040] The content of the acylphosphine-based photoinitiator is preferably 1 to 10 parts by mass, more preferably 2 to 8 parts by mass, per 100 parts by mass of the compound having a (meth)acryloyl group in the curable composition.

[0041] [(C) Thermosetting component] (C) As the thermosetting component, various ones commonly used in the art can be listed. For example, known compounds such as blocked isocyanate compounds, epoxy compounds, and oxetane compounds can be used. Among them, in the present invention, a latent thermosetting component in which the functional group in the structure is protected by a protecting group can be preferably used. By using such a latent thermosetting component, unintended reactions in the curable composition under accidental conditions can be suppressed, and its storage stability can be enhanced. Also, it has excellent inkjet printability at 50 °C, and the protecting group can be easily removed by heating or the like when the reaction is desired. In the present invention, "latent" means a property that does not show activity at normal temperature or under slightly heated conditions, but shows thermosetting properties when activated by heating at a high temperature of 80 °C or higher.

[0042] The above-mentioned latent thermosetting component is preferably a blocked isocyanate compound. A blocked isocyanate compound is preferably a compound having a plurality of blocked isocyanate groups in one molecule. A blocked isocyanate group is a group in which an isocyanate group is protected by reaction with a blocking agent and temporarily inactivated, and when heated to a predetermined temperature, the blocking agent dissociates to generate an isocyanate group. That is, since a blocked isocyanate compound has a protecting group (blocking agent), the protecting group desorbs by heating when necessary, and only then does it function as an isocyanate, so it is easy to handle in terms of excellent storage stability.

[0043] As the polyisocyanate compound having a plurality of isocyanate groups, for example, aromatic polyisocyanate, aliphatic polyisocyanate, or alicyclic polyisocyanate is used.

[0044] Specific examples of the aromatic polyisocyanate include, for example, diphenylmethane diisocyanate (e.g., 4,4'-diphenylmethane diisocyanate), tolylene diisocyanate (e.g., 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate), naphthalene diisocyanate (e.g., naphthalene-1,5-diisocyanate), xylylene diisocyanate (e.g., o-xylylene diisocyanate, m-xylylene diisocyanate), 2,4-tolylene dimer, tolidine diisocyanate, and the like.

[0045] Specific examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate, and the like.

[0046] Specific examples of the alicyclic polyisocyanate include bicycloheptane triisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, 4,4-methylenebis(cyclohexyl isocyanate), and isophorone diisocyanate.

[0047] Examples of the polyisocyanate compound include adducts, biuret compounds, and isocyanurate compounds of the isocyanate compounds mentioned above. The adduct of an isocyanate compound is, for example, an adduct-type isocyanate compound obtained by reacting one of the above-described various isocyanate compounds with a polyhydric alcohol having a functionality of 3 or more, such as glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, erythritol, sorbitol, pentaerythritol, or dipentaerythritol. The biuret compound of an isocyanate compound is, for example, a biuret-type isocyanate compound obtained by reacting one of the above-described various isocyanate compounds with water. The isocyanurate compound of an isocyanate compound is, for example, an isocyanurate-type isocyanate compound obtained by isocyanurating one of the above-described various isocyanate compounds.

[0048] Examples of the adduct-type isocyanate compound include those having a structure represented by the following formula obtained by reacting hexamethylene diisocyanate with trimethylolpropane. [Chemical formula]

[0049] Examples of the isocyanate blocking agent include phenolic blocking agents such as phenol, cresol, xylenol, chlorophenol, and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-valerolactam, γ-butyrolactam, and β-propiolactam; active methylene blocking agents such as ethyl acetoacetate and acetylacetone; alcohol blocking agents such as methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, benzyl ether, methyl glycolate, butyl glycolate, diacetone alcohol, methyl lactate, and ethyl lactate; oxime blocking agents such as formaldehyde oxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monoxime, and cyclohexanone oxime; mercaptan blocking agents such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methyl thiophenol, and ethyl thiophenol; acid amide blocking agents such as acetamide and benzamide; imide blocking agents such as succinimide and maleimide; amine blocking agents such as xylylidene, aniline, butylamine, and dibutylamine; imidazole blocking agents such as imidazole and 2-ethylimidazole; imine blocking agents such as methyleneimine and propyleneimine; pyrazole blocking agents such as dimethylpyrazole, etc.

[0050] The blocked isocyanate compound can be used alone or in combination of two or more. Examples of commercially available products include blocked isocyanate (E402-B80) manufactured by Asahi Kasei Corporation.

[0051] The content of the blocked isocyanate compound is preferably 5 to 20 parts by mass, particularly preferably 10 to 15 parts by mass, based on 100 parts by mass of the compound having a (meth)acryloyl group in the curable composition. By setting it within such a range, a cured product with a good balance between flexibility and hardness can be obtained.

[0052] [(D) Polymerization inhibitor] (D) The polymerization inhibitor is represented by the following general formula (1): [Chemical formula] (In the formula, n represents an integer from 1 to 4, R represents an alkyl group, an aryl group, an aralkyl group, an alkoxyalkyl group, a glycidyl group, a hydroxyalkyl group or an aryloxyalkyl group, and when there are a plurality of OR groups, the Rs may be the same or different. X, Y and Z may be the same or different and each represents a hydrogen atom, an alkyl group or an aryl group, and among these, X and Y may be bonded to each other to form a saturated or unsaturated 6-membered ring) and is at least one or more of the compounds having a condensed polycyclic aromatic skeleton represented by this formula.

[0053] In the above formula (1), n is preferably 1 to 3, more preferably 1 to 2, and even more preferably 2.

[0054] In the above formula (1), R can be an alkyl group having 1 to 12 carbon atoms (specifically, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, and n-dodecyl group), and among these, alkyl groups having 1 to 6, more preferably 1 to 4, and particularly preferably 1 or 2 can be mentioned.

[0055] In the above formula (1), R can be an aryl group having 6 to 12 carbon atoms (specifically, for example, a tolyl group, a xylyl group, a phenyl group, a naphthyl group), among which, it may preferably be an aryl group having 6 to 8 carbon atoms.

[0056] In the above formula (1), R can be an aralkyl group having 7 to 13 carbon atoms (specifically, for example, a benzyl group, an α-methylbenzyl group, an α,α-dimethylbenzyl group, a phenethyl group), among which, it may preferably be an aralkyl group having 7 to 10 carbon atoms.

[0057] In the above formula (1), R can be an alkoxyalkyl group having 2 to 15 carbon atoms (specifically, for example, a group in which one hydrogen atom in the above alkyl group having 1 to 12 carbon atoms is substituted with an alkoxy group having 1 to 3 carbon atoms such as a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group), among which, preferably 2 to 9, more preferably 2 to 7 alkoxyalkyl groups can be mentioned.

[0058] In the above formula (1), R can be a hydroxyalkyl group having 1 to 12 carbon atoms (specifically, for example, a group in which one hydrogen atom in the above alkyl group having 1 to 12 carbon atoms is substituted with a hydroxyl group), among which, preferably 1 to 6, more preferably 1 to 4, particularly preferably 1 or 2 hydroxyalkyl groups can be mentioned.

[0059] In the above formula (1), R can be an aryloxyalkyl group having 7 to 12 carbon atoms (specifically, for example, a phenoxymethyl group, a phenoxyethyl group, a phenoxypropyl group, and a phenoxybutyl group), among which, it may preferably be an aryloxyalkyl group having 7 to 10 carbon atoms.

[0060] X is preferably a hydrogen atom, or preferably an alkyl group having 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 or 2 carbon atoms. Y and Z are preferably hydrogen atoms.

[0061] In the above formula, it is more preferable that all of X, Y, and Z are hydrogen atoms and R is the above alkyl group having 1 to 6 carbon atoms. In the above formula, it is even more preferable that all of X, Y, and Z are hydrogen atoms, R is the above alkyl group having 1 to 6 carbon atoms, and n is 2. 1,4-Dimethoxynaphthalene or 1,4-diethoxynaphthalene is particularly preferable.

[0062] (D) Specific compounds of the polymerization inhibitor include, for example, 1,4-dimethoxynaphthalene, 1,4-diethoxynaphthalene, 1,6-diethoxynaphthalene, 2,7-diethoxynaphthalene, 2,6-dimethoxynaphthalene, 2-ethyl-1,4-diethoxynaphthalene, 1,4-dibutoxynaphthalene, 1,4-dihexyloxynaphthalene, 1,4-diglycidyloxynaphthalene, 1,4-bis(2-hydroxyethoxy)naphthalene, 1,4-bis(2-hydroxypropoxy)diethoxynaphthalene, 9,10-dibutoxyanthracene, 9-butoxyanthracene, 1,4-didodecyloxynaphthalene, 1,4-diphenethyloxynaphthalene.

[0063] Examples of commercially available products include QS-40 (1,4-diethoxynaphthalene) manufactured by Kawasaki Kasei Kogyo Co., Ltd. and 1,4-dimethoxynaphthalene manufactured by Merck & Co., Inc.

[0064] (D) The content of the polymerization inhibitor is preferably 1 part by mass or less, more preferably 0.01 to 0.2 part by mass, based on 100 parts by mass of the compound having a (meth)acryloyl group in the curable composition.

[0065] [(E) Flame retardant] The flame retardant can be blended for the purpose of imparting flame retardancy to the cured product obtained after curing the curable composition. The flame retardant is preferably one that can enhance the flame retardancy of the cured product without impairing the coatability, resolution, or warpage of the cured product. In particular, the (E) flame retardant used in the present invention has the advantage of being able to improve the warpage, tack, transparency, and storage stability after exposure in a well-balanced manner.

[0066] The (E) flame retardant used in the present invention is a flame retardant having a phenoxy group substituted by any one of a cyano group (-CN), a hydroxyl group (-OH), and a methyl group, and a phosphazene structure. Specifically, it preferably has a hexaphenoxycyclotriphosphazene structure as a basic skeleton, and among the six phenoxy groups in the structure, at least two are substituted by a cyano group (-CN) or a hydroxyl group (-OH).

[0067] In a preferred embodiment, only one of the two phenoxy groups bonded to the phosphorus atom in the hexaphenoxycyclotriphosphazene structure is substituted by one cyano group (-CN), and the phenoxy group thus substituted is present in two in the entire hexaphenoxycyclotriphosphazene structure.

[0068] In another preferred embodiment, both of the two phenoxy groups bonded to the phosphorus atom in the hexaphenoxycyclotriphosphazene structure are substituted by one cyano group (-CN), and the phenoxy groups thus substituted are present in six in the entire hexaphenoxycyclotriphosphazene structure.

[0069] In another preferred embodiment, only one of the two phenoxy groups bonded to the phosphorus atom in the hexaphenoxycyclotriphosphazene structure is substituted by one hydroxyl group (-OH), and the phenoxy group thus substituted is present in three in the entire hexaphenoxycyclotriphosphazene structure.

[0070] More preferably, the (E) flame retardant in the present invention has the following structure: [Chemical formula] Or [Chemical formula] Or [Chemical formula] It has any one of the following structures.

[0071] Examples of commercially available preferred (E) flame retardants include FP-300B, FP-300, and SPH-100 (all manufactured by Fushimi Pharmaceutical Co., Ltd.).

[0072] The content of the (E) flame retardant is preferably 1 to 50 parts by mass, more preferably 5 to 40 parts by mass, and particularly preferably 10 to 20 parts by mass with respect to 100 parts by mass of the compound having a (meth)acryloyl group in the curable composition. By setting it within such a range, warping of the cured product after exposure can be suppressed.

[0073] [Defoaming agent · Levelling agent] As the defoaming agent · levelling agent, compounds such as silicon, modified silicon, mineral oil, vegetable oil, aliphatic alcohol, fatty acid, metal soap, fatty acid amide, polyoxyalkylene glycol, polyoxyalkylene alkyl ether, polyoxyalkylene fatty acid ester, etc. can be used, and particularly, silicon compounds and modified silicon compounds are preferred. Examples of commercially available products include BYK-307 (silicon-based additive) manufactured by BYK Chemie Japan.

[0074] The content of the defoaming agent · levelling agent is preferably 0.05 part by mass to 0.5 part by mass with respect to 100 parts by mass of the compound having a (meth)acryloyl group in the curable composition.

[0075] [Antioxidant] By using an antioxidant (reducing agent), when the base is copper, the adhesion between the cured product of the curable composition and the base can be improved. As the antioxidant, for example, it is preferable to use adenine, vinyltriazine, dicyandiamide, o-tolylbiguanide, melamine, etc., and it is particularly preferable to use melamine. Examples of commercially available products include melamine manufactured by Nissan Chemical Industries, Ltd.

[0076] The content of the antioxidant is preferably 0.5 parts by mass to 1.5 parts by mass with respect to 100 parts by mass of the compound having a (meth)acryloyl group in the curable composition.

[0077] [Other components] In the curable composition of the present invention, if necessary, a thixotropy-imparting agent, thickener, coupling agent, dispersant, polymerization retarder, ion scavenger, solvent, etc. can be contained.

[0078] [Cured product] Since the curable composition of the present invention has a viscosity suitable for printing by the inkjet method, the curable composition of the present invention can be directly patterned on a substrate for a printed wiring board or the like. Since the curable composition of the present invention contains a photoinitiator, 50 mJ / cm 2 ~1000 mJ / cm 2 The composition can be photocured by performing light irradiation. The light irradiation is performed by irradiating active energy rays such as ultraviolet rays, electron beams, and chemical rays.

[0079] In the inkjet printer, the active energy ray irradiation can be performed, for example, by attaching a light source such as a high-pressure mercury lamp, a metal halide lamp, or an ultraviolet LED to the side surface of the print head and performing scanning by moving the print head or the substrate. In this case, printing and active energy ray irradiation can be performed almost simultaneously.

[0080] The curable composition after photocuring is thermally cured by using a known heating means, for example, a heating furnace such as a hot air furnace, an electric furnace, or an infrared induction heating furnace. As the heating conditions, it is preferable to heat at 150°C to 170°C for 5 minutes to 120 minutes.

[0081] The photocured curable composition and the cured product obtained by thermally curing the photocured curable composition (the cured product obtained from the curable composition of the present invention) are each transparent or translucent, being uncolored or almost uncolored. Here, the transparency (transparent to translucent) in the present invention means that when measured by the method of JIS K7361-1, the total light transmittance is 80% or more.

[0082] The cured product obtained from the curable composition of the present invention is also excellent in flexibility, and thus is suitable as, for example, a solder resist (insulating cured film) for a flexible printed wiring board. Examples of the substrate for the flexible printed wiring board include films made of glass polyimide, polyimide, polyethylene terephthalate, liquid crystal polymer, polycarbonate, and the like.

[0083] [Electronic component] Furthermore, the present invention also provides an electronic component having the cured product of the present invention. In the present invention, the electronic component means a component used in an electronic circuit, and includes passive components such as resistors, capacitors, inductors, and connectors, in addition to active components such as printed wiring boards, particularly flexible printed wiring boards, transistors, light-emitting diodes, and laser diodes. The cured product of the curable composition of the present invention is suitable as these insulating cured films.

Examples

[0084] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited only to these examples.

[0085] [Preparation of composition] Each component was blended at the ratios (unit: parts by mass) shown in Tables 1 and 2 below, and these were stirred with a dissolver (room temperature, rotation speed 500 rpm, for 5 minutes). Then, using a bead mill (conical type K-8 (manufactured by Bühler)), dispersion was carried out for 2 hours with zirconia beads (under the conditions of rotation speed 1200 rpm, discharge rate 20%, bead particle size 0.65 mm, and filling rate 88%) to obtain the curable compositions of the present invention (Examples 1 to 9) and the curable compositions of the comparative examples (Comparative Examples 1 to 4). Also, these curable compositions were confirmed to have a viscosity of 15 mPa·s or less at 50°C by the following viscosity measurement method.

[0086] <Formation conditions of cured coating film (cured product)> Each curable composition of Examples 1 to 9 and Comparative Examples 1 to 4 was applied onto a transparent PET (polyethylene terephthalate) having a thickness of 50 μm as a substrate using an inkjet printing apparatus CPS6151 (manufactured by Microcraft). An array KM1024iSHE (manufactured by Microcraft, coating liquid droplet volume 6 pL, number of nozzles 2×1024, head temperature 55°C) was used. SGHUV-UN-L042-B (manufactured by Microcraft, LED light source, wavelength 365 nm) was used as a light source, and UV exposure (500 mJ / cm 2 ) was performed on each applied curable composition for photocuring. Then, using a hot air circulation drying oven DF610 (manufactured by Yamato Scientific Co., Ltd.) as a heating device, the curable composition after photocuring was subjected to thermal curing (main curing) at 120°C for 60 minutes to form a cured coating film.

[0087] <Touch dryness (tackiness)> For each curable composition of Examples 1 to 9 and Comparative Examples 1 to 4, the touch dryness of the curable composition after photocuring obtained according to the above <Formation conditions of cured coating film (cured product)> was evaluated. The evaluation criteria are as follows. 〇: No stickiness ×: Sticky

[0088] <Warpage> For each of the curable compositions of Examples 1 to 9 and Comparative Examples 1 to 4, the warpage of the cured coating film obtained according to the above <Formation Conditions of Cured Coating Film (Cured Product)> was evaluated. Specifically, for the evaluation of warpage, the cured coating film formed on PET (substrate) after heat curing was cut out into a 5 cm square, and the cured coating film was placed on a table. With the table as a reference, the height of each of the four corners was measured, and the sum was taken as the warpage height.

[0089] <Color Comparison> For each of the curable compositions of Examples 1 to 9 and Comparative Examples 1 to 4, the color comparison of the cured coating film (cured product) obtained according to the above <Formation Conditions of Cured Coating Film (Cured Product)> after heat curing was evaluated. Specifically, for the evaluation of color comparison, the degree of coloring of the cured coating film after heat curing and the degree of coloring of transparent PET as the substrate were visually compared (specifically, visually by one person). The evaluation criteria are as follows. Note that for Examples 1 to 9 and Comparative Examples 1 to 4, the total light transmittance measured by the method of JIS K7361-1 was 80% or more in all cases. + : The degree of coloring of the cured coating film is equivalent to that of PET. ++ : The cured coating film is slightly more colored. +++ : The cured coating film is clearly more colored.

[0090] <Viscosity Change Rate> For each of the curable compositions of Examples 1 to 9 and Comparative Examples 1 to 4, the viscosity change rate [viscosity of the curable composition after being stored in a sealed state at 50°C for 2 weeks / viscosity of the curable composition before sealed storage (initial viscosity)] was evaluated. Note that the viscosity measurement was taken as the value at 50°C, 100 rpm, and 30 seconds, and was measured using a cone plate viscometer (TVE-33H, manufactured by Toki Sangyo Co., Ltd.) with 1°34’×R24 as the cone and rotor.

[0091]

Table 1

[0092]

Table 2

[0093] Details of each component in Table 1 are as follows. Adduct type BI: Adduct type block isocyanate; E402-B80 (manufactured by Asahi Kasei Corporation) (however, the one vacuum-dried at room temperature for 24 hours to remove the solvent was used); A-BPE-4: Ethoxylated bisphenol A diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.); AOMA: Methyl α-(allyloxymethyl)acrylate (manufactured by Nippon Shokubai Co., Ltd.); DPGDA: Dipropylene glycol diacrylate (manufactured by Daicel Ornex Co., Ltd.); 4-HBA: 4-Hydroxybutyl acrylate (manufactured by Mitsubishi Chemical Corporation)); FP-300B: Phosphazene compound (manufactured by Fushimi Pharmaceutical Co., Ltd.); BYK-307: Silicon-based additive (manufactured by BYK-Chemie Japan Co., Ltd.); Melamine: (manufactured by Nissan Chemical Industries, Ltd.); Omnirad® TPO: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (manufactured by IGM Resins B.V.); 2-ITX: 2-Isopropylthioxanthone (manufactured by ARKEMA); Omnirad® 1173: 2-Hydroxy-2-methyl-1-phenylpropanone (manufactured by IGM Resins B.V) Irgacure® OXE-02: 1-(O-Acetyloxime)-1-[9-methyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone (manufactured by BASF Japan Ltd.); Irgacure® OXE-01: 2-(O-Benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione (manufactured by BASF Japan Ltd.); Irgacure® OXE-03: Oxime ester-based photoinitiator (the specific chemical structure is not disclosed by BASF) (manufactured by BASF Japan Ltd.); Kinopower (registered trademark) QS-30: 4-methoxy-1-naphthol (manufactured by Kawasaki Chemical Industry Co., Ltd.); Kinopower (registered trademark) QS-40: 1,4-diethoxynaphthalene (manufactured by Kawasaki Chemical Industry Co., Ltd.); 1,4-dimethoxynaphthalene: (manufactured by Merck)

[0094] The present invention is not limited to the configurations and examples of the above embodiments, and various modifications are possible within the scope of the gist of the invention.

Claims

1. (A) A compound having a (meth)acryloyl group, (B) A photoinitiator, (C) A thermosetting component, and (D) A polymerization inhibitor, and the compound having a (meth)acryloyl group in (A) contains a compound having a (meth)acryloyl group having a hydroxyl group, the photoinitiator in (B) contains an oxime ester-based photoinitiator and an acylphosphine-based photoinitiator, the content of the oxime ester-based photoinitiator is 0.01 to 5 parts by mass with respect to 100 parts by mass of the compound having a (meth)acryloyl group in the curable composition, and the content of the acylphosphine-based photoinitiator is 1 to 10 parts by mass with respect to 100 parts by mass of the compound having a (meth)acryloyl group in the curable composition, the thermosetting component in (C) contains a blocked isocyanate compound, the polymerization inhibitor in (D) is represented by the following general formula (1): 【Chemical formula 1】 (In the formula, n represents an integer from 1 to 4, R represents an alkyl group, an aryl group, an aralkyl group, an alkoxyalkyl group, a glycidyl group, a hydroxyalkyl group or an aryloxyalkyl group, and when there are a plurality of OR groups, R may be the same or different. X, Y and Z may be the same or different and each represents a hydrogen atom, an alkyl group or an aryl group, and among these, X and Y may be bonded to each other to form a saturated or unsaturated 6-membered ring.) and is at least one or more of the compounds having a condensed polycyclic aromatic skeleton represented by the formula, A curable composition characterized by having a viscosity of 15 mPa·s or less at 50°C.

2. The curable composition according to claim 1, further comprising (E) a flame retardant.

3. The curable composition according to claim 2, wherein the content of the (E) flame retardant is 1 to 50 parts by mass with respect to 100 parts by mass of the compound having a (meth)acryloyl group (A).

4. The curable composition according to claim 2 or 3, wherein the (E) flame retardant contains phenoxyphosphazene.

5. The curable composition according to any one of claims 1 to 4, wherein the content of the (D) polymerization inhibitor is 1 part by mass or less with respect to 100 parts by mass of the compound having a (meth)acryloyl group (A).

6. The curable composition according to any one of claims 1 to 5, wherein the (D) polymerization inhibitor is 1,4-dimethoxynaphthalene and / or 1,4-diethoxynaphthalene.

7. A cured product, characterized in that the curable composition according to any one of claims 1 to 6 is cured.

8. An electronic component, characterized by having the cured product according to claim 7.

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