Curable composition, cured product, and printed circuit board

Abstract

To provide a curable composition that has good discharge properties and good crack resistance, solder heat resistance, and tensile strength when cured. [Solution] A curable composition characterized by containing three or more compounds having an isocyanurate skeleton.

Description

Technical Field

[0001] The present invention relates to a curable composition, a cured product, and a printed wiring board.

Background Art

[0002] A solder resist is used for the surface layer portion of a printed wiring board or a substrate for a semiconductor package, and serves to protect the circuit pattern formed on the substrate from external impacts and stresses such as heat and moisture.

[0003] As a method for coating a substrate with a solder resist, a screen printing method or the like has been conventionally known. In the film formation method by the screen printing method, there are many processing steps such as development, and the work is also complicated. Therefore, in recent years, a method of directly applying a curable resin composition to a necessary portion by an inkjet method has also been adopted. In the inkjet method, there is no need to produce a screen mesh, a photomask, etc., and the number of steps can be reduced compared to the screen printing method etc., so there are great merits from the viewpoints of cost reduction and tact time reduction.

[0004] On the other hand, in the inkjet method, in order to stably eject ink from an inkjet head, it is required that the ink viscosity is low to some extent. Although an inkjet device capable of printing by heating the inkjet head has been developed, printing troubles such as nozzle clogging may easily occur due to drying of the ink near the nozzle due to heating. Also, by diluting the curable resin composition for inkjet with a high-boiling solvent, the ejection property at an inkjet head with a small nozzle size can be somewhat improved, but problems such as a decrease in the film thickness after drying and curing occur when the ratio of the solvent increases.

[0005] In particular, when a piezoelectric method is adopted in the inkjet method, the volume of the pressure chamber is changed by deforming the wall of a tiny pressure chamber connected to the nozzle with a piezoelectric (piezo) element, thereby pressurizing the ink filling the pressure chamber and ejecting ink droplets from the nozzle. For this reason, the viscosity of the curable resin composition in a piezo head is required to be tens of mPa·s or less. In addition, in practical terms, it is necessary to satisfy various requirements regarding ejection performance, such as the curable resin composition not solidifying in the head, not forming precipitates, and not causing clogging due to drying in the fine nozzle.

[0006] Patent Document 1 discloses a photocurable thermosetting resin composition comprising a (meth)acryloyl group-containing monomer, a blocked isocyanate, and a photopolymerization initiator, which has a viscosity suitable for application to inkjet printers, can directly draw patterns on substrates for printed circuit boards, cures at a relatively low temperature, and further exhibits excellent adhesion, chemical resistance, heat resistance, and insulating properties after curing. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2013 / 146706 Pamphlet [Overview of the project] [Problems that the invention aims to solve]

[0008] In view of the above circumstances, the present invention aims to provide a curable composition that has good discharge properties and good crack resistance, solder heat resistance, and tensile strength when cured. [Means for solving the problem]

[0009] As a result of diligent research to achieve the above objective, the present inventors have found that by including three compounds having an isocyanurate skeleton, the compatibility of the curable composition is improved and good discharge properties are obtained, thus completing the present invention.

[0010] In other words, the curable composition according to the present invention is characterized by containing three or more compounds having an isocyanurate skeleton. The curable composition according to the embodiment of the present invention has good compatibility. A curable composition with good compatibility is less likely to solidify in the ink head and less likely to produce precipitates, thus reducing the likelihood of nozzle clogging. For this reason, the curable composition according to the embodiment of the present invention has good discharge properties and is suitable as a curable composition for use in inkjet printing.

[0011] Furthermore, in embodiments of the present invention, it is preferable that at least three of the three or more compounds having an isocyanurate skeleton are selected from the group consisting of (A) thermosetting compounds having an isocyanurate skeleton and (B) (meth)acrylate compounds having an isocyanurate skeleton.

[0012] Furthermore, in embodiments of the present invention, it is preferable that at least two of the three or more compounds having an isocyanurate skeleton are (A) thermosetting compounds having an isocyanurate skeleton.

[0013] A curable composition according to an embodiment of the present invention preferably comprises (A) a thermosetting compound having an isocyanurate skeleton and (B) a (meth)acrylate compound having an isocyanurate skeleton.

[0014] In another embodiment of the present invention, it is preferable that the mixing ratio of component (A) to component (B) is 5 to 15:10 to 20.

[0015] Furthermore, it is preferable that the curable composition according to an embodiment of the present invention contains four or more compounds having an isocyanurate skeleton.

[0016] In an aspect of the present invention, the component (A) is preferably a blocked isocyanate compound having an isocyanurate skeleton.

[0017] In an aspect of the present invention, it is preferable that the curable composition further contains a photopolymerization initiator, a colorant, or a thermosetting catalyst.

[0018] In an aspect of the present invention, the viscosity of the curable composition is preferably 1 to 150 mPa·s at 25°C.

[0019] The curable composition according to an aspect of the present invention can be used for inkjet printing.

[0020] A cured product according to another aspect of the present invention is characterized by being obtained by curing the above-described curable composition.

[0021] A printed wiring board according to another aspect of the present invention is characterized by including the above-described cured product.

[0022] That is, the present invention relates to the following aspects. [1] A curable composition, comprising three or more compounds having an isocyanurate skeleton. [2] The curable composition according to [1], wherein at least three of the three or more compounds having an isocyanurate skeleton are at least one selected from the group consisting of (A) a thermosetting compound having an isocyanurate skeleton and (B) a (meth)acrylate compound having an isocyanurate skeleton. [3] The curable composition according to [1], wherein at least two of the three or more compounds having an isocyanurate skeleton are (A) a thermosetting compound having an isocyanurate skeleton. [4] (A) A thermosetting compound having an isocyanurate skeleton, and (B) A (meth)acrylate compound having an isocyanurate skeleton, and The curable composition according to [1], characterized by containing the same. [5] The curable composition according to [4], wherein the blending ratio of the thermosetting compound having the (A) isocyanurate skeleton and the (meth) acrylate compound having the (B) isocyanurate skeleton is 5 to 15:10 to 20. [6] The curable composition according to any one of [2] to [5], wherein the thermosetting compound having the (A) isocyanurate skeleton is a blocked isocyanate compound having an isocyanurate skeleton. [7] A curable composition characterized by containing four or more compounds having an isocyanurate skeleton. [8] The curable composition according to any one of [1] to [7], further comprising a photopolymerization initiator. [9] The curable composition according to any one of [1] to [8], further comprising a colorant.

[10] The curable composition according to any one of [1] to [9], further comprising a thermosetting catalyst.

[11] The curable composition according to any one of [1] to

[10] , having a viscosity of 150 mPa·s or less at 25°C.

[12] The curable composition according to any one of [1] to

[11] , which is used for inkjet printing.

[13] A cured product characterized by being obtained from the curable composition according to any one of [1] to

[12] .

[14] A printed wiring board comprising the cured product according to

[13] . [Effect of the Invention]

[0023] According to the present invention, it is possible to provide a new curable composition, a cured product, and a printed wiring board. Specifically, the curable composition of the present invention has good compatibility, and thus provides a curable composition with excellent dischargeability. Further, the cured product obtained by curing the curable composition of the present invention has good crack resistance, solder heat resistance, and tensile resistance, and is suitable as a solder resist composition for a printed wiring board. [Modes for Carrying Out the Invention]

[0024] Preferred embodiments of the present invention will be described in detail below. However, the present invention is not limited to the following embodiments.

[0025] [1. Curable composition] A curable composition according to one embodiment of the present invention contains three or more compounds having an isocyanurate skeleton. The compounds having an isocyanurate skeleton improve the compatibility of the curable composition and improve its discharge properties.

[0026] [1-1. Compounds containing an isocyanurate skeleton (essential components)] Examples of compounds having an isocyanurate skeleton include isocyanate compounds having an isocyanurate skeleton, blocked isocyanate compounds having an isocyanurate skeleton, epoxy compounds having an isocyanurate skeleton, (meth)acrylate compounds having an isocyanurate skeleton, and antioxidants having an isocyanurate skeleton.

[0027] From the viewpoint of improving the compatibility of the curable composition, the amount of three or more compounds having an isocyanurate skeleton is preferably 1 to 99% by mass, and more preferably 20 to 50% by mass, in terms of solid content in the curable composition.

[0028] In the curable composition according to this embodiment, at least three of the three or more compounds having an isocyanurate skeleton may be at least one selected from the group consisting of (A) thermosetting compounds having an isocyanurate skeleton and (B) (meth)acrylate compounds having an isocyanurate skeleton.

[0029] In the following, examples of compounds having an isocyanurate skeleton that can be used in the curable composition according to this embodiment include (A) a thermosetting compound having an isocyanurate skeleton, (B) a (meth)acrylate compound having an isocyanurate skeleton, and (C) an antioxidant having an isocyanurate skeleton, but are not limited to these.

[0030] [1-1-1. (A) Thermosetting compounds having an isocyanurate skeleton] The thermosetting compound having an isocyanurate skeleton used in the curable composition according to this embodiment is not particularly limited, and any known and conventional compound may be used. Examples include isocyanate compounds having an isocyanurate skeleton, blocked isocyanate compounds having an isocyanurate skeleton, and epoxy compounds having an isocyanurate skeleton. Among these, blocked isocyanates having an isocyanurate skeleton and epoxy compounds having an isocyanurate skeleton are preferred, and blocked isocyanates having an isocyanurate skeleton are more preferred. Note that (A) thermosetting compounds having an isocyanurate skeleton exclude (B) (meth)acrylates having an isocyanurate skeleton, which will be described later. Thermosetting compounds having an isocyanurate skeleton may be used individually or in combination of two or more. When a thermosetting compound having an isocyanurate skeleton is incorporated, the amount incorporated is preferably 1 to 20% by mass, and more preferably 2 to 16% by mass, on a solid content basis in the curable composition.

[0031] [1-1-1-1. Isocyanate compounds having an isocyanurate skeleton, and blocked isocyanate compounds having an isocyanurate skeleton] As a thermosetting compound having an isocyanurate skeleton used in the curable composition according to this embodiment, an isocyanate compound having an isocyanurate skeleton or a blocked isocyanate compound having an isocyanurate skeleton is preferred from the viewpoint of improving the compatibility of the curable composition. An isocyanate compound having an isocyanurate skeleton, or a blocked isocyanate compound having an isocyanurate skeleton, may be used alone or in combination of two or more. The presence or absence of an isocyanurate skeleton in isocyanate compounds or blocked isocyanate compounds can be confirmed by isocyanate titration using di-n-butylamine solution, gas chromatography, refractive index, viscosity, infrared spectroscopy, etc.

[0032] An isocyanate compound is a compound that has one or more isocyanate groups in one molecule. Blocked isocyanate compounds are compounds that have isocyanate groups blocked by a blocking agent (blocked isocyanate groups). Blocked isocyanate compounds are formed by reacting some or all of the isocyanate groups of an isocyanate compound with a blocking agent, and heating causes the protecting group (residue of the blocking agent) to dissociate and generate the isocyanate group.

[0033] The blocking agent used to block (protect) the isocyanate group can be any agent that reacts with the isocyanate group to protect it and dissociates upon heating to produce an isocyanate group; its type is not particularly limited.

[0034] Examples of isocyanate group blocking agents include lactam-based blocking agents (ε-caprolactam, δ-valerolactam, γ-butyrolactam, β-propiolactam, etc.), active methylene-based blocking agents (diethyl malonate, dimethyl malonate, ethyl acetoacetate, acetylacetone, etc.), oxime blocking agents (formaldehyde, acetaldehyde, acetoxime, methyl ethyl ketone oxime, diacetylmonoxime, cyclohexanone oxime, etc.), and pyrazole-based blocking agents (dimethylpyrazole, etc.). Preferred isocyanate group blocking agents in isocyanate compounds having an isocyanurate skeleton, including oxime-based blocking agents, activated methylene-based blocking agents, lactam-based blocking agents, and pyrazole-based blocking agents, with oxime-based blocking agents, activated methylene-based blocking agents, and pyrazole-based blocking agents being more preferred. The isocyanate group may be protected by a single blocking agent, or two or more blocking agents may be used in combination.

[0035] The isocyanurate skeleton can be obtained by cyclizing and trimerizing isocyanate groups of various aromatic isocyanate compounds, aliphatic isocyanate compounds, alicyclic isocyanate compounds, etc. As isocyanate compounds having an isocyanurate skeleton, or blocked isocyanate compounds having an isocyanurate skeleton, those obtained by cyclizing and trimerizing isocyanate groups of various diisocyanate compounds or triisocyanate compounds are preferred.

[0036] Examples of diisocyanate compounds include aliphatic diisocyanate compounds such as 1,4-tetramethylene diisocyanate, ethyl(2,6-diisocyanate)hexanoate, 1,6-hexamethylene diisocyanate, 1,12-dodecamethylene diisocyanate, and 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate; 1,3- or 1,4-bis(isocyanate methylcyclohexane), 1,3- or 1,4-diisocyanate cyclohexane, 3-isocyanate-methyl-3,5,5-trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4'-diisocyanate, 2, Examples include aliphatic diisocyanate compounds such as 5- or 2,6-diisocyanate methylnorbornane; aromatic diisocyanate compounds such as m- or p-phenylenediisocyanate, torylene-2,4- or 2,6-diisocyanate, diphenylmethane-4,4'-diisocyanate, 1,3-bis(2-isocyanate-2-propyl)benzene, naphthalene-1,5-diisocyanate, diphenyl-4,4'-diisocyanate, 4,4'-diisocyanate-3,3'-dimethyldiphenyl, 3-methyl-diphenylmethane-4,4'-diisocyanate, and diphenyl ether-4,4'-diisocyanate. Examples of triisocyanate compounds include aliphatic triisocyanate compounds such as 1,3,6-hexamethylene triisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane, and 2-isocyanate ethyl (2,6-diisocyanate) hexanoate; alicyclic triisocyanate compounds such as 2,5- or 2,6-diisocyanate methyl-2-isocyanate propyl norbornane; and aromatic triisocyanate compounds such as triphenylmethane triisocyanate and tris(isocyanatephenyl)thiophosphate.

[0037] Examples of commercially available isocyanate compounds having an isocyanurate skeleton, or blocked isocyanate compounds having an isocyanurate skeleton, include Duranate TPA-100, TKA-100, MFA-75B, MHG-80B, TUL-100, TLA-100, TSA-100, TSS-100, TSE-100 (manufactured by Asahi Kasei Corporation), BI-7951, BI-7982, BI-7992, and DP9C / 437 (manufactured by GSI Creos Corporation).

[0038] [1-1-1-2. Epoxy compounds having an isocyanurate skeleton] As the thermosetting compound having an isocyanurate skeleton used in the curable composition according to this embodiment, epoxy compounds having an isocyanurate skeleton can be suitably used. Furthermore, as the epoxy compound having an isocyanurate skeleton, it is preferable that one isocyanurate skeleton has two or more epoxy groups. Epoxy compounds having an isocyanurate skeleton may be used individually or in combination of two or more.

[0039] Examples of epoxy compounds having an isocyanurate skeleton include 1,3,5-triglycidyl isocyanurate, tris(2,3-epoxypropyl) isocyanurate, tris(α-methylglycidyl) isocyanurate, tris(1-methyl-2,3-epoxypropyl) isocyanurate, 1,3,5-tris(2,3-epoxypropyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 1,3,5-tris(3,4- Examples include epoxybutyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris(5,6-epoxybutyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and tris{2,2-bis[(oxiran-2-ylmethoxy)methyl]butyl}-3,3',3''-[1,3,5-triazine-2,4,6(1H,3H,5H)-trione-1,3,5-triyl]tripropanoate.

[0040] Commercially available epoxy compounds containing an isocyanurate skeleton include TEPIC-G, TEPIC-S, TEPIC-SP, TEPIC-HP, TEPIC-L, TEPIC-PAS, TEPIC-VL, TEPIC-FL, and TEPIC-UC (manufactured by Nissan Chemical Industries, Ltd.).

[0041] [1-1-2. (B) (meth)acrylate compounds having an isocyanurate skeleton] In this specification, "(meth)acrylic acid" means "acrylic acid" or "methacrylic acid," "(meth)acrylate" means "acrylate" or "methacrylate," and "(meth)acryloyl group" means "acryloyl group" or "methacryloyl group."

[0042] In the curable composition according to this embodiment, (meth)acrylate compounds having an isocyanurate skeleton can be suitably used from the viewpoint of improving compatibility. (meth)acrylate compounds having an isocyanurate skeleton have an isocyanurate skeleton and a (meth)acryloyl group in their unit structure. (Meth)acrylate compounds having an isocyanurate skeleton may be used individually or in combination of two or more.

[0043] When incorporating an isocyanurate skeleton (meth)acrylate compound, the amount of compound incorporated is preferably 2 to 40% by mass, and more preferably 3 to 30% by mass, in terms of solid content, in the curable resin composition, from the viewpoint of improving the compatibility of the curable resin composition.

[0044] Examples of (meth)acrylate compounds having an isocyanurate skeleton include tris(2-acryloyloxyethyl) isocyanurate, bis(2-acryloyloxyethyl)-2-hydroxyethyl isocyanurate, and ε-caprolactone-modified tris-(2-acryloxyethyl) isocyanurate. Among the (meth)acrylate compounds having the above-mentioned isocyanurate skeleton, tris(2-acryloyloxyethyl) isocyanurate and bis(2-acryloyloxyethyl)-2-hydroxyethyl isocyanurate are preferred from the viewpoint of excellent storage stability.

[0045] Examples of commercially available (meth)acrylate compounds having an isocyanurate skeleton include Aronics M-215, M-313, M-315 (manufactured by Toagosei Co., Ltd.), FA-731A (manufactured by Showa Denko Materials K.K.), A-9300, A-9200YN, A-9300-1CL, A-9300-3CL (manufactured by Shin Nakamura Chemical Industry Co., Ltd.), Photomer 4356 (manufactured by IGM Resins), and TEICA (GX-8430) (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

[0046] [1-1-3. (C) Antioxidants having an isocyanurate skeleton] The antioxidant used in the curable composition according to this embodiment is preferably an antioxidant having an isocyanurate skeleton, and more preferably a hindered phenol-based antioxidant having an isocyanurate skeleton, from the viewpoint of improving the crack resistance of the cured product obtained by curing the curable composition. Furthermore, including an antioxidant having an isocyanurate skeleton among three or more compounds having an isocyanurate skeleton is preferable because it significantly improves long-term reliability (crack resistance A) after the reflow process while maintaining compatibility. Antioxidants having an isocyanurate skeleton may be used individually or in combination of two or more.

[0047] When an antioxidant having an isocyanurate skeleton is incorporated, the amount of the antioxidant incorporated is preferably 0.1 to 10% by mass, and more preferably 0.3 to 6% by mass, in terms of solid content in the curable composition, from the viewpoint of improving the compatibility of the curable composition.

[0048] Examples of antioxidants having an isocyanurate skeleton include 1,3,5-tris(3,5-di-t-butyl-4-hydroxyphenyl)isocyanurate, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris[3(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, and 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid.

[0049] Examples of commercially available antioxidants having an isocyanurate skeleton include Irganox 3114 (manufactured by BASF Japan Ltd.), Cyanox CY-1790, and CY-2777 (manufactured by Sun Chemical Co., Ltd.).

[0050] [1-1-4.Blending ratio] When a curable composition contains (A) a thermosetting compound having an isocyanurate skeleton and (B) a (meth)acrylate compound having an isocyanurate skeleton, the preferred blending ratio, based on solid content by mass, is (A) component : (B) component = 5~15:10~20, and more preferably 8~12:12~18, from the viewpoint of improving the compatibility of the curable composition and improving the crack resistance, solder heat resistance, and tensile strength of the cured product.

[0051] When a curable composition contains (A) a thermosetting compound having an isocyanurate skeleton, (B) a (meth)acrylate compound having an isocyanurate skeleton, and (C) an antioxidant having an isocyanurate skeleton, the preferred blending ratio, based on solid content and mass, is (A) thermosetting compound having an isocyanurate skeleton: (B) (meth)acrylate compound having an isocyanurate skeleton: (C) antioxidant having an isocyanurate skeleton = 5~15:10~20:1~5, and more preferably 8~12:12~18:1~3.

[0052] [1-2. Optional components of the curable composition] The curable composition according to this embodiment may contain thermosetting compounds other than compounds having an isocyanurate skeleton, (meth)acrylate compounds, antioxidants, photopolymerization initiators, colorants, thermosetting catalysts, organic solvents, and other additive components.

[0053] The following describes thermosetting compounds, (meth)acrylate compounds, antioxidants, photopolymerization initiators, colorants, thermosetting catalysts, organic solvents, and other additive components.

[0054] [1-2-1. Thermosetting compound] The thermosetting compound used in the curable composition according to this embodiment is not particularly limited, and any known and commonly used compound may be used. Examples include isocyanate compounds, blocked isocyanate compounds, epoxy compounds, oxetane compounds, melamine compounds, phenol compounds, and the like. Thermosetting compounds may be used individually or in combination of two or more. The amount of thermosetting compound blended in the curable composition is preferably 1 to 20% by mass, and more preferably 2 to 16% by mass, on a solid content basis.

[0055] [1-2-1-1. Isocyanate compounds and blocked isocyanate compounds] An isocyanate compound is a compound that has one or more isocyanate groups in one molecule. Blocked isocyanate compounds are compounds that have isocyanate groups blocked by a blocking agent (blocked isocyanate groups). Blocked isocyanate compounds are formed by reacting some or all of the isocyanate groups of an isocyanate compound with a blocking agent, and heating causes the protecting group (residue of the blocking agent) to dissociate and generate the isocyanate group. By incorporating an isocyanate compound or a blocked isocyanate compound into the curable composition of this embodiment, the curability and the toughness of the cured product can be improved. The isocyanate compound or blocked isocyanate compound may be used alone or in combination of two or more types.

[0056] As the isocyanate compound, an aromatic isocyanate compound, an aliphatic isocyanate compound, or an alicyclic isocyanate compound may be used. Examples of aromatic isocyanate compounds include 1,3-phenylenediisocyanate, 1,4-phenylenediisocyanate, 4,4'-diphenylmethanediisocyanate, 2,4-tolylenediisocyanate, 2,6-tolylenediisocyanate, 2,4-diphenylmethanediisocyanate, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, naphthalene-1,5-diisocyanate, o-xylylenediisocyanate, m-xylylenediisocyanate, and 4,4'-4'-triphenylmethanetriisocyanate. Examples of aliphatic isocyanate compounds include tetramethylene diisocyanate, hexamethylene diisocyanate, ethylene diisocyanate, trimethylhexamethylene diisocyanate, and 4,4-methylenebis(cyclohexyl isocyanate). Examples of alicyclic isocyanate compounds include isophorone diisocyanate, bicycloheptane triisocyanate, and dicyclohexylmethane-4,4'-diisocyanate.

[0057] Furthermore, examples of isocyanate compounds include the adduct, biuret, and isocyanurate forms of the aforementioned isocyanate compounds.

[0058] The blocking agent used to block (protect) the isocyanate group can be any agent that reacts with the isocyanate group to protect it and dissociates upon heating to produce an isocyanate group; its type is not particularly limited.

[0059] Examples of isocyanate group blocking agents include phenolic blocking agents (phenol, cresol, xylenol, chlorophenol, ethylphenol, etc.), lactam blocking agents (ε-caprolactam, δ-valerolactam, γ-butyrolactam, β-propiolactam, etc.), active methylene blocking agents (e.g., diethyl malonate, dimethyl malonate, ethyl acetoacetate, acetylacetone, etc.), and alcohol blocking agents (methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, benzyl alcohol, methyl glycolate, glycolic acid). Examples of blocking agents include butyl, diacetone alcohol, methyl lactate, ethyl lactate, etc., oxime-based blocking agents (formaldehyde, acetaldehyde, acetoxime, methyl ethyl ketone oxime, diacetyl monooxime, cyclohexanone oxime, etc.), pyrazole-based blocking agents (3,5-dimethylpyrazole, etc.), mercaptan-based blocking agents (butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methylthiophenol, ethylthiophenol, etc.), acid amide-based blocking agents (acetanilide, acetic acid amide, benzamide, etc.), imidazole-based blocking agents (imidazole, 2-ethylimidazole, etc.), amine-based blocking agents (diphenylamine, aniline, etc.), imine-based blocking agents (ethyleneimine, etc.), and urea-based blocking agents (urea, thiourea, etc.). Among these, oxime-based blocking agents, activated methylene-based blocking agents, alcohol-based blocking agents, and pyrazole-based blocking agents are preferred, with oxime-based blocking agents and pyrazole-based blocking agents being more preferred. The isocyanate group may be protected by a single blocking agent, or two or more blocking agents may be used in combination.

[0060] [1-2-1-2. Epoxy Compounds] Epoxy compounds are compounds having epoxy groups. By incorporating epoxy compounds into the curable composition of this embodiment, the crosslinking density of the cured product of the curable composition can be increased. The epoxy compound may be used individually or in combination of two or more types.

[0061] As the epoxy compound, a known and conventional compound having one or more epoxy groups can be used, and it is preferable to use an epoxy compound having two or more epoxy groups. Examples of epoxy compounds include monoepoxy compounds such as butyl glycidyl ether, phenyl glycidyl ether, and glycidyl (meth)acrylate; bisphenol A type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, biphenyl-4,4'-diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol or propylene glycol diglycidyl ether, sorbitol polyglycidyl ether, tris(2,3-epoxypropyl) isocyanurate, triglycidyl tris(2-hydroxyethyl) isocyanurate, and other compounds having two or more epoxy groups in one molecule. Among these, epoxy compounds having an isocyanurate skeleton are more preferred.

[0062] Examples of commercially available epoxy compounds include jER 828, 806, 807, YX8000, YX8034, 834 (manufactured by Mitsubishi Chemical Corporation), YD-128, YDF-170, ZX-1059, ST-3000 (manufactured by Nippon Steel Chemical & Material Corporation), EPICLON 830, 835, 840, 850, N-730A, N-695 (manufactured by DIC Corporation), and RE-306 (manufactured by Nippon Kayaku Co., Ltd.).

[0063] [1-2-2. (Meth)acrylate compounds] In the curable composition of this embodiment, from the viewpoint of improving curability, (meth)acrylate compounds having hydroxyl groups, polyfunctional (meth)acrylate compounds, etc., can be suitably used. Due to their polyfunctional nature, a cured product with a high crosslink density can be formed, and as a result, a cured product with excellent adhesion and other properties can be obtained. The above (meth)acrylate compounds may be used individually or in combination of two or more. Regarding the amount of (meth)acrylate compound blended, from the viewpoint of achieving an excellent balance between the initial curing speed, initial adhesion, and subsequent adhesion of the curable composition, it is preferably 50 to 90% by mass in terms of solid content, and more preferably 60 to 90% by mass.

[0064] [1-2-2-1. (Meth)acrylate compounds having hydroxyl groups] Examples of (meth)acrylate compounds having a hydroxyl group include monofunctional and polyfunctional compounds, such as 2-hydroxy-3-acryloyloxypropyl acrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, 2-hydroxy-3-phenoxyethyl acrylate, 2-hydroxy-3-phenoxyethyl methacrylate, 1,4-cyclohexanedimethanol monoacrylate, 1,4-cyclohexanedimethanol monomethacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol monohydroxypentamethacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate. The (meth)acrylate compounds having a hydroxyl group may be used individually or in combination of two or more.

[0065] Examples of commercially available (meth)acrylate compounds having hydroxyl groups include Aronics M-5700 (manufactured by Toagosei Co., Ltd.), 4-HBA (manufactured by Shinryo Co., Ltd.), CHDMMA (manufactured by Mitsubishi Chemical Corporation), BHEA, HPA, HEMA, HPMA (manufactured by Nippon Shokubai Co., Ltd.), Light Ester HO, Light Ester HOP, Light Ester HOA (manufactured by Kyoeisha Chemical Co., Ltd.).

[0066] [1-2-2-2. Polyfunctional (meth)acrylate compounds] Examples of polyfunctional (meth)acrylate compounds include diacrylates of diols such as 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, and 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, diacrylate of diols obtained by adding at least one of ethylene oxide and propylene oxide to neopentyl glycol, diacrylates of glycols such as caprolactone-modified hydroxypivalic acid neopentyl glycol diacrylate, bisphenol A EO (ethylene oxide) adduct diacrylate, and bisphenol A Examples include polyfunctional acrylates and polyfunctional methacrylates that do not have hydroxyl groups, such as hydroxyl group-free polyfunctional acrylates, cyclic diacrylate compounds, propylene oxide (PO) adducts, tricyclodecane dimethanol diacrylate, hydrogenated dicyclopentadienyl diacrylate, and cyclohexyl diacrylate. Polyfunctional (meth)acrylate compounds may be used individually or in combination of two or more.

[0067] Examples of commercially available polyfunctional (meth)acrylate compounds include Light Acrylate 1,6HX-A, 1,9ND-A, 3EG-A, 4EG-A (manufactured by Kyoeisha Chemical Co., Ltd.), HDDA, DPGDA, TPGDA (manufactured by Daicel Ornex Co., Ltd.), Viscoat #195, #230, #230D, #260, #310HP, #335HP, #700HV (manufactured by Osaka Organic Chemical Industry Co., Ltd.), Aronics M-208, M-211B, M-220, M-225, M-240, M-270 (manufactured by Toagosei Co., Ltd.), Laromer LR8863, PO33F (manufactured by BASF Japan Ltd.), and others.

[0068] [1-2-3. Antioxidants] The curable composition according to this embodiment may optionally contain an antioxidant. Examples of antioxidants used in the curable composition according to this embodiment include hindered phenol antioxidants, phosphorus antioxidants, sulfur antioxidants, thioether antioxidants, vitamin antioxidants, lactone antioxidants, amine antioxidants, and the like. Among these antioxidants, hindered phenol-based antioxidants are preferred from the viewpoint of heat resistance and resistance to yellowing. Antioxidants may be used individually or in combination of two or more types. The amount of antioxidant added to the curable composition is preferably 0.1 to 10% by mass, and more preferably 0.3 to 6% by mass, on a solid content basis.

[0069] [1-2-3-1. Hindered phenol antioxidants] Hindered phenol antioxidants are at least one, preferably both, of the phenols. This refers to compounds containing a structure in which the ortho position is substituted with a bulky substituent (hindered phenol structure). Examples of bulky substituents include branched or cyclic alkyl groups, with t-butyl groups being preferred. Examples of hindered phenol antioxidants include 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,1,3-tri(4-hydroxy-2-methyl-5-t-butylphenyl)butane, 1,1-bis(3-t-butyl-6-methyl-4-hydroxyphenyl)butane, 3,5-bis(1,1-dimethylethyl)-4-hydroxybenzenepropanoic acid, and pentaerythrityltetrakis(3,5-di-t-butyl- Examples include 4-hydroxyphenyl)propionate, 3-(1,1-dimethylethyl)-4-hydroxy-5-methylbenzenepropanoic acid, 3,9-bis[1,1-dimethyl-2-[(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, and 1,3,5-trimethyl-2,4,6-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)benzene. Hindered phenol antioxidants may be used individually or in combination of two or more types.

[0070] Examples of commercially available hindered phenol antioxidants include Irganox 1010, 1076, and 1330 (manufactured by BASF Japan Ltd.), and Adeka Stab AO-20, AO-50, AO-60, AO-30, and AO-330 (manufactured by ADEKA Corporation).

[0071] [1-2-4. Photopolymerization Initiators] The photopolymerization initiator used in the curable composition according to this embodiment is not particularly limited, and known and conventional ones can be used. The photopolymerization initiator may be used alone or in combination of two or more types.

[0072] Examples of photopolymerization initiators include 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, and bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylphenylphosphate. Bisacylphosphine oxides such as tylphosphine 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-trimethylbenzoylphenylphosphinate methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloyl Monoacyl phosphine oxides such as isopropyl phenylphosphinate and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate, 1-hydroxycyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-methyl-propan-1-one Hydroxyacetophenones such as 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzoins such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether; benzoin alkyl ethers; benzophenones such as benzophenone, p-methylbenzophenone, Michlar's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, and 4,4'-bisdiethylaminobenzophenone;Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1, 2-(dimethylamino)-2-[(4-methylphenyl)methyl)-1-[4-(4-morpholinyl)phenyl]-1-butanone-1 Acetophenones such as thioxanthone, N,N-dimethylaminoacetophenone; thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, Anthraquinones such as 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, and p-dimethylbenzoate ethyl ester; 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(O-benzoyl oxime), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyl Examples include oxime esters such as oxime; titanosenes such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)phenyl)titanium and bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyr-1-yl)ethyl)phenyl]titanium; phenyl disulfide 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, and tetramethylthiuram disulfide.

[0073] In the curable composition according to this embodiment, the amount of photopolymerization initiator is preferably 1 to 10 parts by mass per 100 parts by mass of the curable composition, excluding the oxime ester-based photopolymerization initiator. When the amount is 1 part by mass or more, the photocurability of the curable composition is good, the film is less likely to peel off, and film properties such as chemical resistance are also good. On the other hand, when the amount is 10 parts by mass or less, an outgassing reduction effect is obtained, and furthermore, light absorption on the surface of the solder resist coating is good, and the deep curing performance is less likely to decrease. More preferably, it is 5 to 10 parts by mass. The amount of oxime ester-based photopolymerization initiator is preferably 0.1 to 5 parts by mass per 100 parts by mass of the curable composition. When the amount is 0.1 parts by mass or more, the photocurability of the curable composition is good, and film properties such as heat resistance and chemical resistance are also good. On the other hand, when the amount is 5 parts by mass or less, light absorption of the solder resist coating is good, and the deep curing performance is less likely to decrease. More preferably, it is 0.5 to 3 parts by mass.

[0074] [1-2-5. Colorants] The curable composition according to this embodiment may contain a colorant. The colorant is not particularly limited as long as it is dispersible in the curable composition, and known and commonly used colorants such as red, blue, green, yellow, white, and black can be used, and may be a pigment, dye, or colorant.

[0075] Specifically, examples include those with a color index number (CI; issued by The Society of Dyers and Colourists) as shown below.

[0076] Red colorants include monoazo, disazo, azolake, benzimidazolon, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone. Blue colorants include phthalocyanine and anthraquinone compounds, and pigment compounds classified as pigments can be used. In addition to these, metal-substituted or unsubstituted phthalocyanine compounds can also be used. Similarly, green colorants include phthalocyanine, anthraquinone, and perylene compounds. In addition to these, metal-substituted or unsubstituted phthalocyanine compounds can also be used. Yellow colorants include monoazo, disazo, condensed azo, benzimidazolon, isoindolinone, and anthraquinone compounds. White colorants include rutile or anatase titanium dioxide. Examples of black colorants include carbon black, graphite, iron oxide, titanium black, anthraquinone, cobalt oxide, copper oxide, manganese, antimony oxide, nickel oxide, perylene, aniline, molybdenum sulfide, and bismuth sulfide. In addition, other colorants such as purple, orange, and brown may be added to adjust the color tone.

[0077] [1-2-6.Thermosetting catalyst] The curable composition according to this embodiment may contain a thermosetting catalyst. Examples of thermosetting catalysts include imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole; amine compounds such as dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, and 4-methyl-N,N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacate dihydrazide; and phosphorus compounds such as triphenylphosphine. In addition, commercially available models include, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (manufactured by Shikoku Chemicals Co., Ltd., U-CAT 3513N, DBU, DBN, U-CAT SA Examples include 102 (manufactured by Sunapro Co., Ltd.). In particular, it is not limited to these, and any thermosetting catalyst for epoxy resins or oxetane compounds, or a catalyst that promotes the reaction between at least one of an epoxy group and an oxetanyl group and a carboxyl group may be used, and may be used alone or in combination of two or more. In addition, S-triazine derivatives such as guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine isocyanuric acid adduct, and 2,4-diamino-6-methacryloyloxyethyl-S-triazine isocyanuric acid adduct may be used, and preferably these compounds that also function as adhesion imparters are used in combination with the thermosetting catalyst.

[0078] [1-2-7. Organic Solvents] The curable composition according to this embodiment may contain an organic solvent to the extent that it does not impair the properties, for purposes such as preparing the curable composition or adjusting the viscosity when applying it to a substrate or film. As organic solvents, known and commonly used organic solvents can be used, such as ketones like methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons like toluene, xylene, and tetramethylbenzene; glycol ethers like cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, and tripropylene glycol monomethyl ether; esters like ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons like octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, and solvent naphtha. These organic solvents may be used individually or in combination of two or more.

[0079] The volatilization drying of organic solvents can be carried out using a hot air circulation drying oven, an IR oven, a hot plate, a convection oven, etc. (using a heat source equipped with a steam-heated air heating method, either by bringing the hot air inside the dryer into countercurrent contact or by blowing it onto the support from a nozzle).

[0080] The amount of organic solvent in the curable composition is preferably changed as appropriate depending on the materials constituting the curable composition, but for example, it can be 0 to 30 parts by mass per 100 parts by mass of the curable composition.

[0081] [1-2-8. Other Additives] The curable composition according to this embodiment may further contain, as needed, components such as photoinitiators, elastomers, mercapto compounds, curing catalysts, thixonating agents, adhesion promoters, block copolymers, chain transfer agents, polymerization inhibitors, copper damage inhibitors, antioxidants, rust inhibitors, thickeners such as organic bentonite and montmorillonite, defoaming agents and leveling agents such as silicone-based, fluorine-based, and polymer-based agents, silane coupling agents such as imidazole-based, thiazole-based, and triazole-based agents, and flame retardants such as phosphinates, phosphate ester derivatives, and phosphazene compounds. These components may be those known in the field of electronic materials.

[0082] The method for producing the curable composition according to this embodiment is not particularly limited. For example, after blending the above components in predetermined proportions, the composition can be produced by kneading or mixing at room temperature using a kneading means such as a three-roll mill, ball mill, bead mill, or sand mill, or by a stirring means such as a super mixer or planetary mixer. Alternatively, pre-kneading or pre-mixing may be performed before the kneading or mixing as needed.

[0083] The viscosity of the curable composition according to this embodiment at room temperature (25°C) is preferably 150 mPa·s or less. The viscosity of the curable composition being within this range at room temperature allows the curable composition to be applied to the substrate with good ejection properties by the inkjet method. The upper limit of the viscosity of the curable composition at room temperature is not particularly limited, but it is preferably 100 mPa·s or less, and more preferably 50 mPa·s or less. Furthermore, while there are no particular limitations on the lower limit of the viscosity of the curable composition at room temperature, from the viewpoint of maintaining the shape of the coating film and controlling the thickness of the coating film, it is preferably 1 mPa·s or higher, and more preferably 5 mPa·s or higher. In this specification, "viscosity" refers to the viscosity measured using a cone-plate type viscometer (TVE-33H, manufactured by Toki Sangyo Co., Ltd.) with a cone rotor of 1°34′×R24, in accordance with the viscosity measurement method using a 10-cone-plate type rotational viscometer specified in JIS Z8803:2011, at 25°C, 100 rpm, and 30 seconds.

[0084] Furthermore, it is preferable that the curable composition according to this embodiment has excellent storage stability. More specifically, even when stored for 5 weeks at 50°C in a light-shielded environment, it is preferable that the viscosity increase of the curable composition (= ((viscosity of the curable composition after storage - initial viscosity of the curable composition) / initial viscosity of the curable composition) × 100) is 50% or less, and more preferably 20% or less.

[0085] The curable composition according to this embodiment is used for forming cured films, particularly permanent films, and is preferably used as an insulating material. Examples of insulating materials include solder resists, interlayer insulating materials, coverlays, and solder dam formation materials, and it is particularly suitable for use as a solder resist. In addition, the curable composition according to this embodiment may be used to form a protective film on a semiconductor wafer.

[0086] [2. Cured product] The curable composition according to this embodiment is obtained by applying the above-described curable composition and curing the coating film, and is prepared by the following procedure. Methods for applying the curable composition according to this embodiment include, for example, adjusting the viscosity to a suitable level using an organic solvent and applying it to a substrate using methods such as inkjet printing, dip coating, flow coating, roll coating, bar coating, screen printing, and curtain coating. While not particularly limited, from the viewpoint of high-definition patterning and the physical properties of the coating film, the inkjet method, in which the curable composition is ejected from the nozzle of an inkjet printer and attached to a desired position on the substrate, is preferred. Therefore, the curable composition according to this embodiment is preferably used for inkjet printing.

[0087] As substrates, we use materials such as printed circuit boards and flexible printed circuit boards with circuits pre-formed with copper, as well as copper-clad laminates for high-frequency circuits using materials such as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / nonwoven epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, fluororesin / polyethylene / polyphenylene ether, polyphenylene oxide / cyanate, etc., and can also use copper-clad laminates of all grades (FR-4, etc.), as well as metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafers, etc.

[0088] A cured product can be obtained by, for example, irradiating the above coating with active energy rays or by heating it to a temperature of 100°C to 250°C.

[0089] In inkjet printers, active energy ray irradiation can be performed by, for example, attaching a light source such as a high-pressure mercury lamp, metal halide lamp, or ultraviolet LED to the side of the print head and scanning by moving the print head or substrate. In this case, printing and active energy ray irradiation can be performed almost simultaneously.

[0090] Suitable light sources for active energy irradiation include LEDs, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, and metal halide lamps. Other available light sources include electron beams, alpha rays, beta rays, gamma rays, X-rays, and neutron beams. One or more light sources can be used, and if more than one light source is used, it is possible to combine light sources of different wavelengths.

[0091] The irradiation dose for active energy rays varies depending on the thickness of the coating film, but is generally 10 to 10,000 mJ / cm². 2 Preferably 20-2000 mJ / cm² 2 more preferably 100-2000 mJ / cm² 2 It can be within the range of

[0092] Heating can be performed by using a heat source equipped with a steam-based air heating method, such as a hot air circulation drying oven, an IR furnace, a hot plate, or a convection oven, to bring hot air into countercurrent contact within the dryer, or by blowing it onto the support from a nozzle.

[0093] [3. Printed circuit board] The printed circuit board according to this embodiment comprises a cured product obtained from the curable composition described above.

[0094] By printing the curable composition according to this embodiment onto a substrate of a printed circuit board and curing it, a printed circuit board can be manufactured that has a cured product with excellent properties such as crack resistance, solder heat resistance, and tensile strength. [Examples]

[0095] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0096] [1. Preparation of curable composition] A thermosetting compound, an epoxy compound, a (meth)acrylate compound, an antioxidant, and a photopolymerization initiator were blended in the amounts (parts by mass) shown in Tables 1 and 2. The mixture was then mixed and kneaded in a bead mill in a container filled with argon gas, and the mixture was filtered through a glass filter with a pore size of 1 μm to obtain the curable compositions of Examples 1 to 11 and Comparative Examples 1 to 4. Note that the ingredient amounts in Tables 1 and 2 represent parts by mass unless otherwise specified.

[0097] Details of each compound listed in Tables 1 and 2 are as follows: <Thermosetting compounds> • Duranate TUL-100 (manufactured by Asahi Kasei Corporation): Isocyanurate form of hexamethylene diisocyanate (low viscosity type) • BI-7982 (manufactured by GSI Creos Corporation): Isocyanurate of hexamethylene diisocyanate blocked with 3,5-dimethylpyrazole • Duranate TPA-100 (manufactured by Asahi Kasei Corporation): Isocyanurate derivative of hexamethylene diisocyanate • Duranate TLA-100 (manufactured by Asahi Kasei Corporation): Isocyanurate derivative of hexamethylene diisocyanate (low viscosity type) • TEPIC-SP (manufactured by Nissan Chemical Industries, Ltd.): 1,3,5-triglycidyl isocyanurate <(meth)acrylate compounds> • Laromer LR8863 (manufactured by BASF Japan Ltd.): EO-modified trimethylolpropane triacrylate • NK Ester A-9300 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): Tris-(2-acryloxyethyl) isocyanurate • DPGDA (manufactured by Daicel Ornex Co., Ltd.): Dipropylene glycol diacrylate • 4-HBA (Mitsubishi Chemical Corporation): 4-Hydroxybutyl acrylate <Antioxidant> Irganox 3114 (manufactured by BASF Japan Ltd.): 1,3,5-Tris(3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate Irganox 1330 (manufactured by BASF Japan Ltd.): 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene <Photopolymerization initiator> • Omnirad379 (manufactured by IGM Resins): Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone • OXE-02 (manufactured by BASF Japan Ltd.): Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(0-acetyloxime) • DETX (manufactured by Nippon Kayaku Co., Ltd.): 2,4-dimethylthioxanthone

[0098] [Table 1]

[0099] [Table 2]

[0100] [2. Evaluation of compatibility of curable compositions] Each component of Examples 1-11 and Comparative Examples 1-4, as described in Tables 1 and 2, was mixed and stirred in a dissolver (rotation speed 500 rpm, stirring time 1 hour) while adjusting the temperature to 50 degrees Celsius or lower. Within 30 minutes after stirring, it was visually confirmed whether each component had mixed without separation, and the compatibility was evaluated according to the following criteria. ○: Each component is mixed without separating. ×: The components did not separate and did not mix together.

[0101] [3. Evaluation of the discharge properties of the curable composition] The curable compositions of Examples 1-11 and Comparative Examples 1-4 were each placed in cartridges of an inkjet printer (Ricoh MH2420), and test patterns were continuously printed by ejecting the curable compositions from the nozzles of the inkjet printer. The ejection performance was evaluated according to the following criteria. ○: The curable composition was able to be dispensed stably for 1 hour. ×: The nozzle became clogged before 1 hour had passed since the start of dispensing, making it impossible to dispense the curable composition.

[0102] [4. Evaluation of long-term reliability (crack resistance A), solder heat resistance, and tensile strength] <Fabrication of test boards> Each test substrate was prepared according to the following manufacturing conditions. For simplicity, the following evaluations were performed using an applicator for coating. Base material: FR-4 copper-clad laminate (150mm x 95mm x 1.6mm thick) Polishing: Buffing (using a double set of Scotch brite SF (equivalent to #600) and UEF (equivalent to #1000)) Application: Applicator (manufactured by ERICHSEN), film thickness during application: 30 μm UV bump: 300mJ / cm 2 Using a high-pressure mercury lamp (ORC HMW-713) as the light source. Thermosetting conditions: 150°C, 60 minutes. Heating device used: DF610 (manufactured by Yamato Scientific Co., Ltd.) Rear UV: 1000mJ / cm 2 Using a high-pressure mercury lamp (ORC HMW-713) as the light source.

[0103] After buffing the copper-clad laminate, it was washed with water and dried. Then, the curable compositions of Examples 1-11 and Comparative Examples 1-4 were applied to the substrate using an applicator, and the substrates were irradiated with a high-pressure mercury lamp (HMW-713, manufactured by Oak Manufacturing Co., Ltd.) at a light irradiation dose of 300 mJ / cm² for each substrate. 2 The following procedure was followed: After light irradiation, the substrates were heated at 150°C for 60 minutes to cure. After curing, each substrate was irradiated with a high-pressure mercury lamp (HMW-713, manufactured by Oak Manufacturing Co., Ltd.) at a light irradiation dose of 1000 mJ / cm². 2 These were used as the following test substrates.

[0104] <Testing and evaluation of long-term reliability (crack resistance A)> An 80 μm aperture was formed in the cured pattern of a curable composition on a test substrate using a CO2 laser manufactured by Hitachi Via Mechanics Co., Ltd., and then desmear treatment was performed. The resulting printed circuit board was subjected to a thermal history of -65°C for 30 minutes and 150°C for 30 minutes as one cycle. After 1000 cycles, the presence or absence of crack formation in the cured pattern around the lands was confirmed by observing it at a measurement magnification of 1000x using a digital microscope (Keyence Corporation, VHX-6000). The long-term reliability (crack resistance A) was evaluated according to the following criteria based on the crack formation rate (%) shown in the following formula. The number of apertures observed was 100. Crack occurrence rate (%) = (Number of numerical apertures with cracks / Number of numerical apertures observed) × 100 ◎: Crack occurrence rate is 3% or less ○: Crack occurrence rate greater than 3% but less than or equal to 10% △: Crack occurrence rate greater than 10% but less than or equal to 50% ×: Crack occurrence rate is greater than 50%

[0105] <Evaluation of solder heat resistance> Rosin-based flux was applied to the cured material of the test substrate, and the substrate was immersed in a 260°C solder bath for 10 seconds three times. The peeling of the cured coating was observed, and the solder heat resistance was evaluated according to the following criteria. ○: No peeling occurred. △: There was some peeling (more than 90% of the area was not peeling).

[0106] <Evaluation of tensile strength> The cured material on the test substrate was peeled off the copper-clad laminate and cut into strips measuring 80 mm × 10 mm × 50 μm to be used as test specimens. Tensile tests were performed on each test specimen using a tensile testing machine (Shimadzu Corporation, AG-X) at a speed of 1 mm / min, and the elongation at the breaking point at 25°C was measured. The tensile strength was evaluated according to the following criteria. ○: Elongation at fracture point is 10% or more △: Elongation at fracture point is 5% or more but less than 10% ×: Breaking point elongation less than 5%

[0107] [Evaluation of storage stability at 5.50°C and reliability at high temperatures (crack resistance B)] <50℃ storage stability> The curable compositions of Examples 1 to 11 and Comparative Examples 1 to 4 were prepared using the same method as described in "1. Preparation of Curable Compositions". The viscosity of the above curable composition at 25°C was measured using a cone-plate viscometer (TVE-33H, manufactured by Toki Sangyo Co., Ltd.) with a cone rotor of 1°34'×R24, at 100 rpm for 30 seconds, in accordance with JIS Z 8803 "Method for measuring viscosity using a 10-cone-plate rotational viscometer," and this was defined as the initial viscosity. Each of the above curable compositions was sealed in a 50 mL light-shielding bottle and stored in a 50°C constant temperature bath for 5 weeks. After returning to room temperature, the viscosity of the curable composition at 25°C was measured using the same method as above, and the viscosity increase rate relative to the initial viscosity was determined. The storage stability at 50°C was evaluated according to the following criteria. ◎: Thickening rate of 20% or less ○: Thickness is greater than 20% and 50% or less. △: Thickness rate greater than 50% but less than or equal to 100% ×: Gelation occurs

[0108] <Reliability at high temperatures (crack resistance B)> The cured products of the curable compositions of Examples 1-11 or Comparative Examples 1-4, prepared on test substrates using the same method as described in "Preparation of Test Substrates" above, were plated using an electroless nickel plating bath and an electroless gold plating bath, with nickel at 0.5 μm and gold at 0.03 μm, respectively. Next, for the reflow process, to evaluate reliability at high temperatures, a maximum temperature of 260°C for 500 seconds was performed for 6 cycles. After that, the cured product patterns around the lands were observed at a magnification of 1000x using a digital microscope (Keyence Corporation, VHX-6000) to check for the presence or absence of cracks. High-temperature reliability (crack resistance B) was evaluated according to the following criteria based on the crack occurrence rate (%) shown in the following formula. The number of lands observed was 100. Crack occurrence rate (%) = (Number of lands with cracks / Number of lands observed) × 100 ◎: Crack occurrence rate is 1% or less ○: Crack occurrence rate greater than 1% but less than or equal to 5% ×: Crack occurrence rate is greater than 5%

[0109] As is clear from the results shown in Table 1, the curable compositions of Examples 1 to 8, which contained three or more compounds having an isocyanurate skeleton, exhibited good compatibility and excellent discharge properties. Furthermore, when cured, the curable compositions of Examples 1 to 8, which contained three or more compounds having an isocyanurate skeleton, showed good results in terms of long-term reliability (crack resistance A), solder heat resistance, and tensile strength. On the other hand, the curable composition of Comparative Example 1, which contained only one compound having an isocyanurate skeleton, showed good compatibility and dischargeability, but exhibited poor long-term reliability (crack resistance A) and tensile strength after curing. Furthermore, the curable composition of Comparative Example 2, which contained only two compounds having an isocyanurate skeleton, showed poor compatibility and dischargeability, poor tensile strength after curing, and inferior long-term reliability (crack resistance A) and solder heat resistance compared to the cured products of Examples 1 to 8. The curable composition of Comparative Example 3, which contained only two compounds having an isocyanurate skeleton, showed good compatibility and dischargeability, but exhibited poor long-term reliability (crack resistance A) after curing, and inferior solder heat resistance and tensile strength compared to the cured products of Examples 1 to 8.

[0110] Table 1 shows that cured products obtained by curing curable compositions containing a thermosetting compound having an isocyanurate skeleton, a (meth)acrylate compound having an isocyanurate skeleton, and an antioxidant having an isocyanurate skeleton, as in Examples 1 to 5, exhibit good long-term reliability (crack resistance A). Furthermore, cured products obtained by curing curable compositions containing four types of compounds having an isocyanurate skeleton, as in Examples 6 and 10, and curable compositions containing five types of compounds having an isocyanurate skeleton, as in Example 9, tended to yield good results in both long-term reliability (crack resistance A) and reliability at high temperatures (crack resistance B). This is thought to be due to the improved compatibility of the curable composition resulting from the large number of compounds having an isocyanurate skeleton.

[0111] Furthermore, Tables 1 and 2 show that the curable composition of Example 1 exhibits improved compatibility and discharge properties compared to the curable composition of Comparative Example 2. Comparing the components of the curable compositions of Example 1 and Comparative Example 2 in Tables 1 and 2, the curable composition of Example 1 contains not only the antioxidant Irganox 3114, which has an isocyanurate skeleton, but also two other compounds having an isocyanurate skeleton (thermosetting compound BI-7982, which has an isocyanurate skeleton, and NK ester A-9300, which has an isocyanurate skeleton). In contrast, the curable composition of Comparative Example 2 contains only the thermosetting compound BI-7982, which has an isocyanurate skeleton. Therefore, it is considered that the curable composition of Example 1, by containing three compounds having an isocyanurate skeleton, exhibits better compatibility and discharge properties compared to the curable composition of Comparative Example 2, which contains only two compounds having an isocyanurate skeleton.

[0112] From the results of the 50°C storage stability in Examples 5-11 in Table 1, it can be seen that using a blocked isocyanate compound having an isocyanurate skeleton as the thermosetting compound having an isocyanurate skeleton results in better 50°C storage stability compared to using an epoxy compound having an isocyanurate skeleton. This is thought to be because blocked isocyanate compounds having an isocyanurate skeleton are easier to control by thermal polymerization in low temperature ranges such as 50°C compared to epoxy compounds having an isocyanurate skeleton. Furthermore, from the results of the 50°C storage stability in Examples 1-11, it can be seen that the more types of thermosetting compounds having an isocyanurate skeleton there are, the better the 50°C storage stability. This is thought to be due to the improved compatibility that comes from having a wider variety of thermosetting compounds having an isocyanurate skeleton.

[0113] Furthermore, the curable compositions of Examples 6 and 9-11 in Table 1 contain four or more compounds having an isocyanurate skeleton, and it can be seen that they provide good results in terms of compatibility, extrusion, long-term reliability (crack resistance A), reliability at high temperatures (crack resistance B), solder heat resistance, elongation in tensile measurements, and storage stability at 50°C.

Claims

1. A curable composition characterized by comprising three or more compounds having an isocyanurate skeleton and dipropylene glycol diacrylate, (A) A thermosetting compound having an isocyanurate skeleton (excluding the blocked isocyanates having an isocyanurate skeleton described below and (B) (meth)acrylate compounds having an isocyanurate skeleton described below) or an antioxidant having an isocyanurate skeleton, Block isocyanate compounds having an isocyanurate skeleton (excluding (B) below, (meth)acrylate compounds having an isocyanurate skeleton), (B) A (meth)acrylate compound having an isocyanurate skeleton, Includes, A curable composition in which the blending ratio of the (B) block isocyanate compound having an isocyanurate skeleton to the (B) (meth)acrylate compound having an isocyanurate skeleton is 2.5 to 10:15 on a mass basis in terms of solid content.

2. The curable composition according to claim 1, further comprising (A) one or more thermosetting compounds having an isocyanurate skeleton (excluding (B) the (meth)acrylate compounds having an isocyanurate skeleton).

3. The curable composition according to claim 2, wherein the (A) thermosetting compound having an isocyanurate skeleton (excluding the (B) (meth)acrylate compound having an isocyanurate skeleton) is at least one isocyanate compound having an isocyanurate skeleton.

4. The curable composition according to any one of claims 1 to 3, further comprising a photopolymerization initiator.

5. The curable composition according to any one of claims 1 to 3, further comprising a coloring agent.

6. The curable composition according to any one of claims 1 to 3, further comprising a thermosetting catalyst.

7. A curable composition according to any one of claims 1 to 3, wherein the viscosity at 25°C is 150 mPa·s or less.

8. A curable composition according to any one of claims 1 to 3, used for inkjet printing.

9. A cured product characterized by being obtained from a curable composition according to any one of claims 1 to 3.

10. A printed circuit board characterized by comprising the cured material described in claim 9.

Images