WO2021157282A1 - Curable composition, and dry film and cured object obtained therefrom - Google Patents

Abstract

[Problem] To provide a curable composition capable of forming solder resists which combine flux resistance and folding endurance. [Solution] The curable composition comprises (A) an alkali-soluble resin having at least any one structure selected from among a bisphenol A structure, a bisphenol F structure, and a urethane structure, (B) a photopolymerization initiator, and (C) an epoxy resin having an isocyanurate structure, wherein the epoxy resin (C) having an isocyanurate structure has a structure in which a nitrogen atom contained in the isocyanurate structure has been bonded to an epoxy group by an alkylene chain having two or more carbon atoms. [Selected drawing] None

Description

Curable composition, its dry film and cured product

The present invention relates to a curable composition, particularly a curable composition capable of forming a cured product having both flux resistance and bendability.

Conventionally, a solder resist (SR) is formed on the printed wiring board to protect the circuit, and a semiconductor chip or the like is soldered (mounted) on the printed wiring board on which the solder resist is formed. As a composition for forming such a solder resist, for example, for a circuit board based on a photosensitive resin composition containing a carboxyl group-containing photosensitive polymer as described in Patent Document 1. Examples include solder resist ink.

On the other hand, when soldering, flux is usually applied to the surface of the connection circuit, but in the application process, the flux is exposed to the entire surface of the printed wiring board on which the solder resist is formed. This flux removes oxides and dirt from the circuit connection surface and prevents oxidation during heating. Furthermore, it lowers the surface tension of the melted solder and improves the wettability of the solder to the joint. There is also an effect.
On the other hand, in view of the increasing frequency of use of so-called flexible printed wiring boards, which are used by bending printed wiring boards, the solder resist formed on the printed wiring boards can withstand bending. Flexibility to the extent that it can be obtained is also required.

Japanese Unexamined Patent Publication No. 11-6517

That is, the solder resist has flux resistance, that is, the ability to maintain adhesion to the printed wiring board without peeling from the printed wiring board even during high-temperature soldering after application of the flux. Is required. Not only that, the solder resist is also required to have bendability that does not cause cracks even when the printed wiring board is bent.

However, in this regard, the solder resist obtained from the conventional composition as described in Patent Document 1 is liable to be deteriorated by the flux component and has insufficient flexibility, so that both flux resistance and bendability can be achieved at the same time. It was not easy to achieve.

Therefore, in view of the above points, as a result of diligent studies by the present inventor, a curable composition containing an alkali-soluble resin having a bisphenol A structure and an epoxy resin having a specific structure having both an isocyanurate structure and an alkylene structure has been obtained. We have found that a solder resist having both flux resistance and bendability can be formed, and completed the present invention.

That is, the present invention
(A) An alkali-soluble resin having at least one of a bisphenol A structure, a bisphenol F structure, and a urethane structure,
(B) Photopolymerization initiator and
(C) An epoxy resin having an isocyanurate structure and
A curable composition containing
The epoxy resin having the (C) isocyanurate structure has a structure in which a nitrogen atom and an epoxy group in the isocyanurate structure are bonded by an alkylene chain having 2 or more carbon atoms.
The present invention relates to the curable composition.
Further, a preferred embodiment of the present invention relates to a curable composition further containing a powder or crystalline epoxy resin, preferably an epoxy resin having a biphenyl structure.
A more preferred embodiment of the present invention also relates to a curable composition further containing an epoxy resin having a dicyclopentadiene structure.
Further, in a more preferable embodiment of the present invention, the mass ratio of the epoxy resin having the (C) isocyanurate structure, the powdery or crystalline epoxy resin, and the epoxy resin having a dicyclopentadiene structure is 1: 2. For curable compositions of ~ 6: 1 ~ 3.
A more preferred embodiment of the present invention relates to a curable composition further containing urethane beads and / or epoxidized polybutadiene.
A more preferred embodiment of the present invention relates to a curable composition further containing a cellulose resin.
In addition, another aspect of the present invention is a dry film having a resin layer obtained from the curable composition, a cured product obtained by curing the resin layer of the curable composition or the dry film, and a cured product. , Also related to electronic parts having the cured product.

The present invention provides a curable composition capable of forming a solder resist having excellent flux resistance and bendability.

Hereinafter, each component that can constitute the curable composition of the present invention will be described.

[(A) Alkali-soluble resin]
The alkali-soluble resin (A) used in the present invention has at least one of a bisphenol A structure, a bisphenol F structure, and a urethane structure, but has a structure other than these structures as described later. Of course, it can be used in combination with an alkali-soluble resin.

The alkali-soluble resin (A) is a resin containing one or more functional groups of a phenolic hydroxyl group, a thiol group and a carboxyl group and is soluble in an alkaline solution, preferably a compound having two or more phenolic hydroxyl groups. , A carboxyl group-containing resin, a compound having a phenolic hydroxyl group and a carboxyl group, and a compound having two or more thiol groups. As the alkali-soluble resin, a carboxyl group-containing resin or a phenolic hydroxyl group-containing resin can be used, but a carboxyl group-containing resin is preferable.

The carboxyl group-containing resin can be made alkaline developable because it contains a carboxyl group. Further, from the viewpoint of photocurability and development resistance, it is preferable to have an ethylenically unsaturated group in the molecule in addition to the carboxyl group, but only a carboxyl group-containing resin having no ethylenically unsaturated group is used. You may. The ethylenically unsaturated group is preferably derived from acrylic acid or methacrylic acid or a derivative thereof. Among the carboxyl group-containing resins, a carboxyl group-containing resin having a urethane structure, a carboxyl group-containing resin using bisphenol A type epoxy resin or bisphenol F type epoxy resin as a starting material, and a carboxyl group containing bisphenol A or bisphenol F as a starting material. Resin is preferred. Specific examples of the carboxyl group-containing resin include compounds (either oligomers or polymers) listed below.

(1) Bisphenol A type epoxy resin or bisphenol F type epoxy resin is reacted with (meth) acrylic acid, and dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride is added to the hydroxyl group existing in the side chain. A carboxyl group-containing photosensitive resin to which an object has been added. Here, the bifunctional or higher polyfunctional epoxy resin is preferably solid.

(2) A (meth) acrylic acid is reacted with a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl groups of a bisphenol A type epoxy resin or a bisphenol F type epoxy resin with epichlorohydrin, and the generated hydroxyl groups are dibasic acid anhydride. A carboxyl group-containing photosensitive resin to which an object is added. Here, the bifunctional epoxy resin is preferably solid.

(3) The bisphenol A type epoxy resin or the bisphenol F type epoxy resin contains at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, and an unsaturated group such as (meth) acrylic acid. Polybasic acid anhydrides such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and adipic acid with respect to the alcoholic hydroxyl group of the reaction product obtained by reacting with a monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting with.

(4) An unsaturated group-containing monocarboxylic acid such as (meth) acrylic acid is added to the reaction product obtained by reacting a condensate of bisphenol A or bisphenol F with aldehydes and an alkylene oxide such as ethylene oxide or propylene oxide. A carboxyl group-containing photosensitive resin obtained by reacting the obtained reaction product with a polybasic acid anhydride.

(5) An unsaturated group-containing monocarboxylic acid is reacted with a reaction product obtained by reacting bisphenol A or bisphenol F with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate, and the obtained reaction product is polybasic. A carboxyl group-containing photosensitive resin obtained by reacting an acid anhydride.

(6) Diisocyanate compounds such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates, and polycarbonate-based polyols, polyether-based polyols, polyester-based polyols, polyolefin-based polyols, acrylic-based polyols, and bisphenol A-based An end carboxyl group-containing urethane resin obtained by reacting an acid anhydride with the end of a urethane resin obtained by a double addition reaction of a diol compound such as an alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

(7) Molecules such as hydroxyalkyl (meth) acrylate during the synthesis of a carboxyl group-containing urethane resin by a double addition reaction between a diisocyanate, a carboxyl group-containing dialcohol compound such as dimethylolpropionic acid or dimethylolbutyric acid, and a diol compound. A carboxyl group-containing urethane resin obtained by adding a compound having one hydroxyl group and one or more (meth) acryloyl groups to the terminal (meth) acrylic.

(8) During the synthesis of a carboxyl group-containing urethane resin by a double addition reaction of a diisocyanate, a carboxyl group-containing dialcohol compound, and a diol compound, an isophorone diisocyanate and an equimolar reaction product of pentaerythritol triacrylate, etc., 1 in the molecule. A carboxyl group-containing urethane resin that is terminally (meth) acrylicated by adding a compound having one isocyanate group and one or more (meth) acryloyl groups.

(9) A carboxyl group-containing photosensitive resin obtained by adding a compound having a cyclic ether group and a (meth) acryloyl group to one of the above-mentioned carboxyl group-containing resins (1) to (8).

Examples of the alkali-soluble resin having a structure other than the alkali-soluble resin (A) include compounds (either oligomers or polymers) listed below.
(10) Carboxyl group-containing photosensitive obtained by copolymerization of an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate, and isobutylene. resin.

(11) A carboxyl group obtained by reacting a polyfunctional oxetane resin as described later with a dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid, and adding a dibasic acid anhydride to the generated primary hydroxyl group. A carboxyl group formed by adding a compound having one epoxy group and one or more (meth) acryloyl groups in one molecule such as glycidyl (meth) acrylate and α-methylglycidyl (meth) acrylate to the contained polyester resin. Containing photosensitive resin.

(12) A carboxyl group-containing photosensitive resin obtained by adding a compound having a cyclic ether group and a (meth) acryloyl group in one molecule to the above-mentioned carboxyl group-containing resin (10) or (11).

Here, (meth) acrylate is a general term for acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions below.

Here, the acid value of the carboxyl group-containing resin is preferably 40 to 150 mgKOH / g. When the acid value of the carboxyl group-containing resin is 40 mgKOH / g or more, alkaline development becomes good. Further, by setting the acid value to 150 mgKOH / g or less, it is possible to easily draw a normal resist pattern. More preferably, it is 50 to 130 mgKOH / g.

The blending amount of the alkali-soluble resin (A) as described above is preferably 15 to 35% by mass in the total composition. In the case of 15 to 35% by mass, the coating film strength is good, the viscosity of the composition is appropriate, and the coatability and the like are improved.

[(B) Photopolymerization Initiator]
As the photopolymerization initiator (B), any photopolymerization initiator known as a photopolymerization initiator or a photoradical generator can be used, and for example, bis- (2,6-dichlorobenzoyl) can be used. ) 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 Bisacylphosphine oxides such as oxides, 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, pivaloylphenylphos Monoacylphosphine oxides such as isopropyl phosphate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 1-hydroxy-cyclohexylphenylketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2 -Hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane- Hydroxyacetophenones such as 1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n -Benzoyls such as butyl ether; Benzoylalkyl ethers; Benzoyls such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone; acetophenone, 2,2 - Dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 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, N, N-dimethylaminoacetophenone and other acetophenones; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethyl Thioxanthones such as thioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylantraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, Anthracinones 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-dimethylbenzoic acid ethyl ester Classes; 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole -3-Il]-, Oxime esters such as 1- (O-acetyloxime); bis (η5-2,4-cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-) Pyrrole-1-yl) phenyl) titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3- (2- (1-pyll-1-yl) ethyl) phenyl] titanocene such as titanium; Examples thereof include phenyldisulfide 2-nitrofluorene, butyloin, anisoine ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide and the like. As the photopolymerization initiator, one type may be used alone, or two or more types may be used in combination.

The blending amount of the (B) photopolymerization initiator is preferably 8 to 15 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble resin. Within this range, the surface curability is good, halation is unlikely to occur, and good resolution can be obtained.

[(C) Epoxy resin having an isocyanate structure]
In the curable composition of the present invention, an epoxy resin having an isocyanurate structure has a structure in which a nitrogen atom and an epoxy group in the isocyanate structure are bonded by an alkylene chain having two or more carbon atoms. Epoxy resin is contained. In particular, an epoxy resin having a structure in which the number of carbon atoms of the alkylene chain is 2 or more and 5 or less is preferable. When the number of carbon atoms of the alkylene chain is in the range of 2 to 5, effective flux resistance and bendability can be compatible with each other in the cured product obtained from the curable composition. Not only that, the original developability of the curable composition can be maintained.

Such an epoxy resin having an isocyanurate structure (C) used in the present invention preferably has a structure represented by the following formula (I).

(During the ceremony,
R ₁ , R ₂ and R ₃ each independently represent an alkylene group having 2 to 5 carbon atoms.
n is 0 or 1, but not all n represent 0 at the same time)

Of these, a particularly preferable _{structure has a structure in which R 1} , R ₂ and R ₃ simultaneously represent an alkylene group having 3 carbon atoms and n simultaneously represents 1.

Specific products of the epoxy resin having the (C) isocyanurate structure preferably used in the present invention include, for example, TEPIC (registered trademark) -VL or TEPIC (registered trademark) -FL (both manufactured by Nissan Chemical Industries, Ltd.). Can be mentioned.

The blending amount of the epoxy resin having the (C) isocyanurate structure is preferably 5 to 15 parts by mass with respect to 100 parts by mass of the (A) carboxyl group-containing resin. Within this range, not only good flux resistance and bendability can be imparted to the cured product at the same time, but also the original developability of the curable composition can be maintained.

[Inorganic filler]
The curable composition of the present invention may contain an inorganic filler in order to suppress the curing shrinkage and improve properties such as adhesion and hardness.
The inorganic filler is not particularly limited, and known and commonly used fillers such as silica, crystalline silica, Neuburg silica soil, aluminum hydroxide, glass powder, talc, clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica, and the like. Inorganic fillers such as aluminum hydroxide, barium sulfate, barium titanate, iron oxide, non-fibrous glass, hydrotalcite, mineral wool, aluminum silicate, calcium silicate, and zinc flower can be used. Of these, silica is preferable, and spherical silica is more preferable because it has a small surface area and stress is dispersed throughout, so that it is unlikely to be the starting point of cracks.

The inorganic filler may be subjected to a photoreactive surface treatment so as to have a vinyl group, a styryl group, a methacrylic group, an acrylic group or the like as the photocurable reactive group. In this case, the methacrylic group, the acrylic group or vinyl may be treated. Groups are particularly preferred. Further, as the thermosetting reactive group, a hydroxyl group, a carboxyl group, an isocyanate group, an amino group, an imino group, an epoxy group, an oxetanyl group, a mercapto group, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group and an oxazoline group. The surface treatment may be thermally reactive so as to have the above, and in this case, an amino group and an epoxy group are particularly preferable. Furthermore, the inorganic filler may have two or more curable reactive groups. As the inorganic filler, surface-treated silica is preferable. By including the surface-treated silica, the CTE can be lowered and the glass transition temperature can be raised.

The introduction method when introducing the curable reactive group on the surface of the inorganic filler is not particularly limited, and it may be introduced by using a known and commonly used method, and a surface treatment agent having a curable reactive group, for example, a curable reactive group. The surface of the inorganic filler may be treated with a coupling agent or the like having the above.

As the surface treatment of the inorganic filler, the surface treatment with a coupling agent is preferable. As the coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent and the like can be used. Of these, a silane coupling agent is preferable.

As the silane coupling agent, a silane coupling agent capable of introducing a curing reactive group into the inorganic filler is preferable. Examples of the silane coupling agent into which a thermosetting reactive group can be introduced include a silane coupling agent having an epoxy group, a silane coupling agent having an amino group, a silane coupling agent having a mercapto group, and a silane coupling agent having an isocyanate group. Agents are mentioned, and among them, a silane coupling agent having an epoxy group is more preferable. Examples of the silane coupling agent into which a photocurable reactive group can be introduced include a silane coupling agent having a vinyl group, a silane coupling agent having a styryl group, a silane coupling agent having a methacryl group, and a silane coupling agent having an acrylic group. Agents are preferred, with silane coupling agents having a methacryl group being more preferred.

When the inorganic filler is surface-treated, it is sufficient that the inorganic filler is blended in the curable resin composition of the present invention in the surface-treated state, and the surface-untreated inorganic filler and the surface treatment agent are separately blended in the composition. Although the inorganic filler may be surface-treated in the above, it is preferable to blend the inorganic filler which has been surface-treated in advance. By blending the inorganic filler that has been surface-treated in advance, it is possible to prevent a decrease in crack resistance and the like due to the surface-treating agent that may remain after being blended separately and is not consumed in the surface treatment. In the case of surface treatment in advance, it is preferable to mix a pre-dispersion liquid in which an inorganic filler is pre-dispersed in a solvent or a resin component, and the surface-treated inorganic filler is pre-dispersed in a solvent and the pre-dispersion liquid is blended in a composition. Alternatively, it is more preferable to sufficiently surface-treat the surface-untreated inorganic filler when pre-dispersing it in a solvent, and then add the pre-dispersion liquid to the composition.

In the curable composition of the present invention, the inorganic filler preferably has an average particle size of 1 μm or less because it is excellent in crack resistance. More preferably, it is 0.8 μm or less. In the present specification, the average particle size refers to the value of D _50, is a value measured using a Microtrac particle size analyzer manufactured by e.g. NIKKISO Corporation.

Further, it is preferable that the maximum particle size of the inorganic filler is 4.0 μm or less because it reacts efficiently and is excellent in crack resistance and adhesion. More preferably, it is 3.0 μm or less. In the present specification, the maximum particle diameter refers to the value of D _100, is a value measured using a Microtrac particle size analyzer manufactured by e.g. NIKKISO Corporation.

When the curable composition of the present invention contains an inorganic filler, the blending amount of the inorganic filler is preferably 15 to 35 parts by mass with respect to 100 parts by mass of the solid content of the curable composition.

[Powder or crystalline epoxy resin]
The curable composition of the present invention preferably contains an epoxy resin, and particularly preferably contains a powder or crystalline epoxy resin. Thereby, the flux resistance of the cured product can be further improved.
A powder or crystalline epoxy resin means an epoxy resin with strong crystallinity. At temperatures below the melting point, polymer chains are regularly arranged, and although it is a solid resin, it has a low viscosity comparable to that of a liquid resin when melted. Refers to a thermosetting epoxy resin.

As the powder or crystalline epoxy resin, it is preferable to use a crystalline epoxy resin having any one of a biphenyl structure, a sulfide structure, a phenylene structure and a naphthalene structure.
Biphenyl type epoxy resins include, for example, "jER (registered trademark) YX4000", "jER (registered trademark) YX4000H", "jER (registered trademark) YL6121H", "jER (registered trademark) YL6640", and "jER (registered trademark) YL6640" manufactured by Mitsubishi Chemical Corporation. It is provided as "jER (registered trademark) YL6677", and the diphenyl sulfide type epoxy resin is provided as "Epototo (registered trademark) YSLV-120TE" manufactured by Nittetsu Chemical & Materials Co., Ltd., and the phenylene type epoxy resin is provided. For example, it is provided as "Epototo (registered trademark) YDC-1312" manufactured by Nittetsu Chemical & Materials Co., Ltd., and the naphthalene type epoxy resin is, for example, "EPICLON (registered trademark) HP-4032" manufactured by DIC Co., Ltd. It is provided as "(Registered Trademark) HP-4032D" and "EPICLON (Registered Trademark) HP-4700". Further, "Epototo (registered trademark) YSLV-90C" manufactured by Nittetsu Chemical & Materials Co., Ltd. and "TEPIC-S" (triglycidyl isocyanurate) manufactured by Nissan Chemical Industries, Ltd. can also be used as the powder or crystalline epoxy resin. Among these, "jER (registered trademark) YX4000" manufactured by Mitsubishi Chemical Corporation, which is a biphenyl type epoxy resin, is preferable because it is excellent in solder heat resistance.
In the curable composition of the present invention, these powders or crystalline epoxy compounds may be used alone or in combination of two or more.

The blending amount of such a powder or crystalline epoxy resin is preferably 20 to 40 parts by mass with respect to 100 parts by mass of the alkali-soluble resin (A) based on the solid content.
When the blending amount of the powder or crystalline epoxy resin is in the above range, the developability and the flux resistance become better.

Further, in the curable composition of the present invention, an epoxy resin other than the powder or crystalline epoxy resin may be further contained in order to improve the heat resistance.
Examples of such an epoxy resin include a non-crystalline cresol novolac type epoxy resin (specific example, product name EPICLON N-695 manufactured by DIC Co., Ltd.) and a non-crystalline phenol novolac type epoxy resin (specific example, DIC stock). Company-made product name EPICLON N-775), non-crystalline bisphenol A novolak type epoxy resin (specific example, DIC Co., Ltd. product name EPICLON N-865), non-crystalline bisphenol A type epoxy resin (specific example, Mitsubishi Chemical Co., Ltd. product name jER1001), non-crystalline bisphenol F type epoxy resin (specific example, Mitsubishi Chemical Co., Ltd. product name jER4004P), non-crystalline bisphenol S type epoxy resin (specific example, manufactured by DIC Co., Ltd.) Product name EPICLON EXA-1514), non-crystalline bisphenol AD type epoxy resin, non-crystalline hydrogenated bisphenol A type epoxy resin, non-crystalline biphenyl novolac type epoxy resin, and non-crystalline special bifunctional epoxy resin (As a specific example, product numbers YL7175-500 and YL7175-1000 manufactured by Mitsubishi Chemical Co., Ltd .; product names EPICLON TSR-960, EPICLON TER-601, EPICLON TSR-250-80BX, EPICLON 1650-75MPX, EPICLON manufactured by DIC Co., Ltd. Non-crystalline epoxy resins such as EXA-4850, EPICLON EXA-4816, EPICLON EXA-4822, and EPICLON EXA-9726 can be mentioned.

Alternatively, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, or phenol novolac type epoxy resin can be mentioned. Specific examples of the liquid epoxy resin include "EXA4032SS", "HP4032SS", "EXA-7311G4S" (naphthalene type epoxy resin) manufactured by DIC Co., Ltd., and "jER828EL" (bisphenol A type epoxy) manufactured by Mitsubishi Chemical Co., Ltd. Resins), "jER807" (bisphenol F type epoxy resin), "jER152" (phenol novolac type epoxy resin), "YL7223", "YL7723" (bisphenol AF type epoxy resin) and other liquid epoxy resins can also be mentioned.

Further or in solid form such as tetrafunctional naphthalene type epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol epoxy resin, naphthol novolac epoxy resin, biphenyl type epoxy resin, or naphthylene ether type epoxy resin. Epoxy resin can be mentioned. Of these, a tetrafunctional naphthalene type epoxy resin, a biphenyl type epoxy resin, or a naphthylene ether type epoxy resin is more preferable, and a biphenyl type epoxy resin is further preferable. Specific examples of such a solid epoxy resin include "HP-4710" (tetrafunctional naphthalene type epoxy resin), "EXA7311", "EXA7311-G3", and "HP6000" (naphthylene ether) manufactured by DIC Co., Ltd. Type epoxy resin), "EPPN-502H" (trisphenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd., "NC7000L" (naphthol novolac epoxy resin), "NC3000H", "NC3000", "NC3000L", "NC3100" (Biphenyl type epoxy resin), "ESN475" manufactured by Nittetsu Chemical & Materials Co., Ltd., "ESN485" (naphthol novolac type epoxy resin), and (Bixilenoll type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd. can be mentioned.

Here, in the curable composition of the present invention, it is preferable that an epoxy resin having a dicyclopentadiene structure is contained as an epoxy resin other than the powder or crystalline epoxy resin. Examples of such an epoxy resin include "HP7200", "HP7200H", "HP7200K", and "HP7200L" manufactured by DIC Corporation.
In particular, the mass ratio of the epoxy resin having the (C) isocyanurate structure, the powdery or crystalline epoxy resin, and the epoxy resin having the dicyclopentadiene structure is 1: 2 to 6: 1 to 3. It is preferable to have. Within this numerical range, the curable compositions of the present invention may exhibit the best flux resistance and bendability.

The mixing ratio of the above powder or crystalline epoxy resin to other epoxy resins is preferably in the range of 5: 1 to 1: 5 in terms of mass ratio.

[Urethane beads / epoxidized polybutadiene]
The curable composition of the present invention preferably contains urethane beads and / or epoxidized polybutadiene in order to improve flexibility. In particular, the inclusion of epoxidized polybutadiene makes the cured product more bendable.
The blending amount of the urethane beads is preferably 20 parts by mass to 35 parts by mass with respect to 100 parts by mass of the alkali-soluble resin (A).
The blending amount of the epoxidized polybutadiene is preferably 8 parts by mass or more and 12 parts by mass or less with respect to 100 parts by mass of the alkali-soluble resin (A).

[Cellulose resin]
The curable composition of the present invention preferably contains a cellulose resin.
By containing the cellulose resin, the amount of the liquid component (for example, the liquid epoxy resin or the monomer component) can be increased, so that the flux resistance can be easily ensured. It also has the effect of suppressing tack (stickiness) during exposure.
The blending amount of the cellulose resin is preferably 5 parts by mass to 10 parts by mass with respect to 100 parts by mass of the alkali-soluble resin (A).

[Colorant]
The curable composition of the present invention may contain a colorant. Specific examples of the colorant include phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, leuco crystal violet, carbon black, naphthalene black, solvent blue and the like. One type of colorant may be used, or two or more types may be used in combination.

The amount of the colorant added is not particularly limited, but is preferably 7 to 15 parts by mass with respect to 100 parts by mass of the alkali-soluble resin (A).

[Organic solvent]
In addition, the curable composition of the present invention may contain an organic solvent for the purpose of preparing the composition, adjusting the viscosity when applied to a base material or a carrier film, and the like.
Examples of such organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethyl benzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol and propylene. Glycol ethers such as glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, tripropylene glycol monomethyl ether; 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, esters such as propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha and solvent naphtha. For example, a known and commonly used organic solvent can be used. These organic solvents can be used alone or in combination of two or more.

[Compound having an ethylenically unsaturated group]
The curable composition of the present invention preferably further contains a compound having an ethylenically unsaturated group as a reactive diluent. Examples of the compound having an ethylenically unsaturated group include a compound having a (meth) acryloyl group such as monofunctional or bifunctional.

Examples of the compound having a monofunctional (meth) acryloyl group include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and hydroxypropyl (meth). Acrylate (meth) acrylates such as meta) acrylates, butoxymethyl (meth) acrylates, 2-ethylhexyl (meth) acrylates, lauryl (meth) acrylates, isodecyl (meth) acrylates, and glycerol mono (meth) acrylates, cyclohexyl (meth) Acrylate-type (meth) acrylates such as acrylates, 4- (meth) acryloxitricyclo [5.2.1.02,6] decane, isobornyl (meth) acrylates, phenoxyethyl (meth) acrylates, benzyls (meth) Aromatic (meth) acrylates such as acrylates, phenyl (meth) acrylates and 2-hydrokey-3-phenoxypropyl (meth) acrylates, modified (meth) acrylates such as aliphatic epoxy-modified (meth) acrylates, tetrahydrofurfuryl (meth) Examples thereof include acrylate, 2- (meth) acryloxyalkyl phosphate, 2- (meth) acryloyloxyethyl phosphate, (meth) acryloyloxyethyl phthalic acid, and γ- (meth) acryloxyalkyltrialkoxysilane.

Specific examples of the compound having a bifunctional (meth) acryloyl group include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, and 1,10-decane. Diacrylate of diol such as diol 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 diol obtained by adding at least one of ethylene oxide and propylene oxide to neopentyl glycol, diacrylate of glycol such as caprolactone-modified neopentyl glycol diacrylate Acrylate, bisphenol A EO adduct diacrylate, bisphenol A PO adduct diacrylate, tricyclodecanedimethanol diacrylate, hydrogenated dicyclopentadienyl diacrylate, diacrylate having a cyclic structure such as cyclohexyl diacrylate, etc. Can be mentioned.
Specific examples of the compound having a trifunctional or higher functional (meth) acryloyl group include pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and dipentaerythritol hexa (dipentaerythritol hexa (). Examples thereof include alkylene polyol poly (meth) acrylates such as meta) acrylates; and polyoxyalkylene glycol poly (meth) acrylates such as propoxylated trimethylolpropane tri (meth) acrylates.

The blending amount of the compound having an ethylenically unsaturated group is preferably 20 parts by mass to 40 parts by mass with respect to 100 parts by mass of the alkali-soluble resin (A).

[Thermosetting catalyst]
The curable composition of the present invention may contain a thermosetting catalyst in order to improve its storage stability and heat resistance.
Examples of such a thermocuring catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole. , 1- (2-Cyanoethyl) -2-ethyl-4-methylimidazole and other imidazole derivatives; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N Examples thereof include amine compounds such as -dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipate dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. In addition, 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 derivatives such as -S-triazine isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine isocyanuric acid adduct can also be used.

The blending amount of the thermosetting catalyst is preferably 2.0 to 4.5 parts by mass with respect to 100 parts by mass of the alkali-soluble resin (A).

[Other ingredients]
The curable composition of the present invention may further contain other additives known and commonly used in the field of electronic materials. Other additives include thermal polymerization inhibitors, UV absorbers, silane coupling agents, plasticizers, flame retardants, antistatic agents, antiaging agents, antibacterial / antifungal agents, leveling agents, thickeners, adhesions. Improving agents, thioxic imparting agents, photoinitiator aids, sensitizers, photobase generators, thermoplastic resins, organic fillers such as additional elastomers, mold release agents, surface treatment agents, dispersants, dispersion aids, surface modifications Examples include pledge agents, stabilizers, and phosphors.

[Dry film]
The curable composition of the present invention can also be used as a dry film. The dry film of the present invention has a resin layer obtained by applying and drying the curable composition of the present invention on a carrier film.
When forming a dry film, first, the curable composition of the present invention is diluted with the above organic solvent to adjust the viscosity to an appropriate level, and then a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, etc. Apply to a uniform thickness on the carrier film with a reverse coater, transfer coater, gravure coater, spray coater, or the like. Then, the applied composition is usually dried at a temperature of 40 to 130 ° C. for 1 to 30 minutes to form a resin layer. The coating film thickness is not particularly limited, but in general, the film thickness after drying is appropriately selected in the range of 3 to 150 μm, preferably 5 to 60 μm.

As the carrier film, a plastic film is used, and for example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, or the like can be used. The thickness of the carrier film is not particularly limited, but is generally selected as appropriate in the range of 10 to 150 μm. More preferably, it is in the range of 15 to 130 μm.

After forming the resin layer made of the curable composition of the present invention on the carrier film, a peelable cover film is further formed on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer. Is preferably laminated. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, surface-treated paper, or the like can be used. The cover film may be smaller than the adhesive force between the resin layer and the carrier film when the cover film is peeled off.

In the present invention, the curable composition of the present invention may be applied onto the cover film and dried to form a resin layer, and a carrier film may be laminated on the surface thereof. That is, as the film to which the curable composition of the present invention is applied when producing the dry film in the present invention, either a carrier film or a cover film may be used.

[Cured product]
To form a cured product using the curable composition of the present invention, the composition is applied onto a substrate, and the resin layer obtained after volatilizing and drying the solvent is exposed (light irradiation). As a result, the exposed portion (the portion irradiated with light) is cured. Specifically, the unexposed portion is exposed to an alkaline aqueous solution (for example, by selectively exposing with active energy rays through a photomask in which a pattern is formed by a contact method or a non-contact method, or by directly exposing the pattern with a laser direct exposure machine. , 0.3 to 3 mass% sodium carbonate aqueous solution) to form a resist pattern. Further, by heating to a temperature of about 100 to 180 ° C. and thermosetting (post-curing), a cured film (cured product) having excellent various properties such as heat resistance, chemical resistance, hygroscopicity, adhesion, and electrical characteristics is obtained. ) Can be formed.

The curable composition of the present invention is, for example, adjusted to a viscosity suitable for the coating method using the above organic solvent, and is subjected to a dip coating method, a flow coating method, a roll coating method, a bar coater method, and a screen on a substrate. A tack-free resin layer is formed by volatilizing and drying (temporarily drying) the organic solvent contained in the composition at a temperature of about 60 to 100 ° C. after coating by a printing method, a curtain coating method, or the like. Can be done. Further, in the case of a dry film in which the curable composition is applied onto a carrier film or a cover film, dried and wound as a film, the resin layer of the dry film of the present invention is brought into contact with the substrate by a laminator or the like. The resin layer can be laminated on the base material by peeling off the carrier film after laminating on the base material.

As the base material, in addition to printed wiring boards and flexible printed wiring boards whose circuits are formed in advance with copper or the like, paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, glass cloth / paper epoxy, etc. It is made of materials such as copper-clad laminates for high-frequency circuits using synthetic fiber epoxy, fluororesin / polyethylene / polyimideene ether, polyphenylene oxide / cyanate, etc., and all grades (FR-4, etc.) of copper-clad laminates. In addition, metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates and the like can be mentioned.

The above-mentioned volatile drying or heat curing is performed by a hot air circulation type drying oven, an IR furnace, a hot plate, a convection oven, etc. It can be carried out by using a method of spraying on a support.

As the exposure machine used for the above-mentioned active energy ray irradiation, if it is a device equipped with a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc., and irradiates the active energy ray in the range of 350 to 450 nm. Often, a direct drawing device (eg, a laser direct imaging device that draws an image directly with a laser from CAD data from a computer) can also be used. The lamp light source or the laser light source of the direct drawing machine may have a maximum wavelength in the range of 350 to 410 nm. The amount of exposure for image formation varies depending on the film thickness and the like, but is generally 20 to 1000 mJ / cm ² , preferably 20 to 800 mJ / cm ² .

The developing method can be a dipping method, a shower method, a spray method, a brush method, etc., and the developing solution includes potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, etc. Alkaline aqueous solutions such as ammonia and amines can be used.

The curable composition of the present invention is suitably used for forming a surface protective film such as a solder resist on a flexible printed wiring board. The curable composition of the present invention may be used as an interlayer insulating layer of a multilayer printed wiring board.

[Electronic components]
The present invention also provides an electronic component having a cured product obtained by curing the curable composition of the present invention. By using the curable composition of the present invention, electronic components having high quality, durability and reliability are provided.
In the present invention, the electronic component means a component used in an electronic circuit, and includes active components such as printed wiring boards, transistors, light emitting diodes, and laser diodes, as well as passive components such as resistors, capacitors, inductors, and connectors. The cured product of the present invention exerts the effect of the present invention as these insulating cured coating films.

The flux in which the cured product of the present invention exhibits good resistance extends to all of the conventional configurations and formulations mainly containing rosin. Examples of such fluxes include SF-270 and SF-. 360 PF-1, SRM-800G (all manufactured by Sanwa Chemical Co., Ltd.), JS-E-15X, JS-EU-31 (all manufactured by Kouki Co., Ltd.), NS-F850-8, NS-F901, NS-334, NS-316F-8 (manufactured by Nippon Superior Co., Ltd.) and the like can be mentioned.

Hereinafter, one aspect of the present invention will be specifically shown with reference to Examples, but of course, the purpose is not to limit the scope of the invention according to the claims of the present application.

<Synthesis example 1. Preparation of carboxyl group-containing acrylate resin (bisphenol A structure)>
A flask equipped with a cooling tube and a stirrer was charged with 456 parts of bisphenol A, 228 parts of water, and 649 parts of 37% formalin, kept at a temperature of 40 ° C. or lower, and added 228 parts of a 25% sodium hydroxide aqueous solution. The reaction was carried out at ° C. for 10 hours. After completion of the reaction, the mixture was cooled to 40 ° C. and neutralized to pH 4 with a 37.5% aqueous phosphoric acid solution while maintaining 40 ° C. or lower. After that, it was allowed to stand and the aqueous layer was separated. After separation, 300 parts of methyl isobutyl ketone was added to uniformly dissolve the mixture, followed by washing with 500 parts of distilled water three times, and the water, solvent and the like were removed under reduced pressure at a temperature of 50 ° C. or lower. The obtained polymethylol compound was dissolved in 550 parts of methanol to obtain 1230 parts of a methanol solution of the polymethylol compound.
When a part of the obtained methanol solution of the polymethylol compound was dried in a vacuum dryer at room temperature, the solid content was 55.2%.

In a flask equipped with a cooling tube and a stirrer, 500 parts of a methanol solution of the obtained polymethylol compound and 440 parts of 2,6-xylenol were charged and dissolved uniformly at 50 ° C. After uniformly dissolving, methanol was removed under reduced pressure at a temperature of 50 ° C. or lower. Then, 8 parts of oxalic acid was added, and the reaction was carried out at 100 ° C. for 10 hours. After completion of the reaction, the distillate was removed at 180 ° C. under a reduced pressure of 50 mmHg to obtain 550 parts of novolak resin A.
In an autoclave equipped with a thermometer, a nitrogen introduction device and an alkylene oxide introduction device, and a stirring device, 130 parts of novolak resin A, 2.6 parts of 50% sodium hydroxide aqueous solution, and toluene / methyl isobutyl ketone (mass ratio = 2/1) 100. The parts were charged, the inside of the system was replaced with nitrogen while stirring, then the temperature was raised by heating, and 60 parts of propylene oxide was gradually introduced at ^{150 ° C. and 8 kg / cm 2 to react.} The reaction was continued for about 4 hours until the gauge pressure reached 0.0 kg / cm ^{2, and then cooled to room temperature.} 3.3 parts of a 36% aqueous hydrochloric acid solution was added to and mixed with this reaction solution to neutralize sodium hydroxide. The neutralization reaction product was diluted with toluene, washed with water three times, and desolvated with an evaporator to have a hydroxyl value of 189 g / eq. A propylene oxide adduct of novolak resin A was obtained. This was an average addition of 1 mol of propylene oxide per equivalent of phenolic hydroxyl group.

189 parts of the obtained novolak resin A propylene oxide adduct, 36 parts of acrylic acid, 3.0 parts of p-toluenesulfonic acid, 0.1 part of hydroquinone monomethyl ether, and 140 parts of toluene were mixed with a stirrer, a thermometer, and an air blowing tube. The mixture was charged into a reactor equipped with Cooled. The obtained reaction solution was washed with water using a 5% NaCl aqueous solution, toluene was removed by distillation under reduced pressure, and then diethylene glycol monoethyl ether acetate was added to obtain an acrylate resin solution having a solid content of 67%.

Next, 322 parts of the obtained acrylate resin solution, 0.1 part of hydroquinone monomethyl ether, and 0.3 part of triphenylphosphine were charged into a four-necked flask equipped with a stirrer and a reflux condenser, and the mixture was charged at 110 ° C. To, 60 parts of tetrahydrophthalic anhydride was added, the mixture was reacted for 4 hours, cooled, and then taken out. The photosensitive carboxyl group-containing resin solution thus obtained had a solid content of 70% and a solid content acid value of 81 mgKOH / g.

<Synthesis example 2. Preparation of Carboxyl Group-Containing Resin for Comparative Examples>
In a 2 liter separable flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen introduction tube, 900 g of diethylene glycol dimethyl ether as a solvent and t-butylperoxy2-ethylhexanoate (Japanese oil and fat) as a polymerization initiator. 21.4 g of Perbutyl O) manufactured by Co., Ltd. was added and heated to 90 ° C. After heating, 309.9 g of methacrylic acid, 116.4 g of methyl methacrylate, and 109.8 g of lactone-modified 2-hydroxyethyl methacrylate (Plaxel FM1 manufactured by Daicel Chemical Industry Co., Ltd.) were added thereto as a polymerization initiator. 4-t-Butylcyclohexyl) Peroxydicarbonate (Perloyl TCP manufactured by Nippon Oil & Fats Co., Ltd.) is added dropwise over 3 hours and aged for another 6 hours to obtain a carboxyl group-containing copolymer resin. rice field. The reaction was carried out in a nitrogen atmosphere.
Next, 363.9 g of 3,4-epoxycyclohexylmethyl acrylate (Cyclomer A200 manufactured by Daicel Chemical Co., Ltd.), 3.6 g of dimethylbenzylamine as a ring-opening catalyst, and polymerization inhibition were added to the obtained carboxyl group-containing copolymer resin. 1.80 g of hydroquinone monomethyl ether was added as an agent, heated to 100 ° C., and stirred to carry out an epoxy ring-opening addition reaction. After 16 hours, a solution having a solid acid value of 108.9 mgKOH / g and a weight average molecular weight of 25,000 and containing 53.8% by weight (nonvolatile content) of a carboxyl group-containing resin having no aromatic ring was obtained. ..

<Examples 1 to 7 and Comparative Examples 1 to 2>
Curable compositions of Examples 1 to 7 and Comparative Examples 1 to 2 by premixing each component with a stirrer and then kneading with a three-roll mill at the components and blending amounts shown in Table 1 below. Got
Unless otherwise specified, the numerical value of the blending amount in the table indicates the mass part of the solid content.

^{* 1} Bisphenol F-type acid-modified epoxy acrylate resin, alkali-soluble resin with bisphenol F structure (solid content 65%); ZFR-1401H; manufactured by Nippon Kayaku Co., Ltd.
^{* 2} Composite acid-modified epoxy acrylate resin, alkali-soluble resin with urethane structure (solid content 52%); UXE-3000; manufactured by Nippon Kayaku Co., Ltd.
^{* 3} Synthetic example 1, alkali-soluble resin having bisphenol A structure
^{* 4} Alkaline-soluble resin other than the above synthesis example 2 and (A) alkali-soluble resin
^{* 5} CAP504-0.2; manufactured by EASTMAN CHEMICAL
^{* 6} Dicyandiamide; Mitsubishi Chemical Corporation's Dicyandiamide, "DICY")
^{* 7} Pariogen Red K3580; manufactured by BASF Japan Ltd.
^{* 8} First Gen Blue 5380; manufactured by DIC Corporation
^{* 9} Last Yellow 8025; manufactured by Arimoto Chemical Industry Co., Ltd.
^{* 10} Black CK-T / SD-TT2259; manufactured by Regino Color Industry Co., Ltd.
^{* 11} BYK-180; manufactured by Big Chemie Japan Co., Ltd.
^{* 12} Silicon KS-66; manufactured by Shinetsu Silicone Co., Ltd.
^{* 13} JMT-784; manufactured by DKSH Japan
^{* 14} Omirad379; manufactured by IGM Resins
^{* 15} Exolit® OP935; manufactured by Clariant
^{* 16} Erosil # R974; manufactured by Toshin Kasei Co., Ltd.
^{* 17} Melamine; manufactured by Nissan Chemical Industries, Ltd.
^{* 18} UCN-5050D Clear; manufactured by Dainichiseika Kogyo Co., Ltd.
^{* 19} Dowanol DPM; manufactured by Dow Chemical Co., Ltd.
^{* 20} Epolide PB3600; manufactured by Daicel Corporation
^{* 21} NK Ester APG-700; manufactured by Shin-Nakamura Chemical Industry Co., Ltd.
^{* 22} BPE-900; manufactured by Shin-Nakamura Chemical Industry Co., Ltd.
^{* 23} HP-7200L; manufactured by DIC Corporation
^{* 24} jER YX-4000; manufactured by Mitsubishi Chemical Corporation
^{* 25} TEPIC (registered trademark) -VL; manufactured by Nissan Chemical Industries, Ltd.
^{* 26} TEPIC (registered trademark) -HP; manufactured by Nissan Chemical Industries, Ltd.

A cured coating film (solder resist) was prepared from the curable compositions of Examples 1 to 7 and Comparative Examples 1 and 2 obtained as shown in Table 1 above, and the cured coating film was flux-resistant as described below. , Developability and bendability were tested.

<Test Example 1. Evaluation of flux resistance>
The curable compositions of Examples 1 to 7 and Comparative Examples 1 and 2 were dried by a screen printing method on a copper foil plate having a thickness of 1.6 mm subjected to pretreatment (0.20 vol% sulfuric acid hydrogen peroxide). The entire surface was coated so that the film thickness was 20 ± 5 μm. Subsequently, after drying in a hot air circulation type drying furnace at 80 ° C. for 30 minutes, exposure (150 mJ / cm ² ) was performed in a 1 mm grid-like 5 × 5 pattern, and an alkaline developer of _{1 wt% Na 2} CO _{3 (30).} It was developed for 60 seconds using (° C.) and then heat-cured at a temperature of 150 ° C. or higher for 60 minutes to obtain cured coating films of Examples 1 to 7 and Comparative Examples 1 and 2, respectively.
Next, a flux (manufactured by Sanwa Chemical Co., Ltd .; SF-270) was applied to the entire surface of each of the formed cured coating films, a dami wafer was placed on the coating film, and the speed was 1.5 m / min in the top 230 ° C. Air conveyor type heating furnace. After heat-treating once for 5 minutes, the degree of peeling of the cured coating film was evaluated by peeling with a cellophane tape of 1.18 N / cm or more specified by JIS Z 1522: 2009. The evaluation is as follows.
Peeling area is 10% or less after peel test ◎
Area of peeling after peel test is more than 10% -50% or less ○
Area of peeling after peel test is over 50% -100% ×

<Test example 2. Developability>
The curable compositions of Examples 1 to 7 and Comparative Examples 1 and 2 were dried by a screen printing method on a copper foil plate having a thickness of 1.6 mm subjected to pretreatment (0.20 vol% sulfuric acid hydrogen peroxide). The dried coating films of Examples 1 to 7 and Comparative Examples 1 to 2, respectively, were coated on the entire surface so as to have a film thickness of 20 ± 5 μm, and then dried at 80 ° C. for 30 minutes in a hot air circulation type drying furnace. Obtained. Next, this dry coating film is _{developed by spraying a 1 wt% Na 2} CO ₃ solution (at 30 ° C.) at a pressure of 0.1 MPa and measuring the development time (dissolution time). The sex was evaluated. The evaluation is as follows.
Development time less than 20 seconds ◎
Development time 20 seconds or more and less than -25 seconds ○
Development time 25 seconds or more ×

<Test Example 3. Foldability>
The curable compositions of Examples 1 to 7 and Comparative Examples 1 and 2 were applied to a 25 μm-thick polyimide film over the entire surface so as to have a film thickness of 20 ± 5 μm after drying by a screen printing method. Subsequently, it is dried at 80 ° C. for 30 minutes in a hot air circulation type drying furnace, exposed (150 mJ / cm ² ), developed with an alkaline developer (30 ° C.) of 1 wt% Na ₂ CO _{3, and then developed for 60 seconds.} It was thermally cured at a temperature of 150 ° C. or higher for 60 minutes to obtain cured coating films of Examples 1 to 7 and Comparative Examples 1 and 2, respectively.
Next, it was bent 180 °, a weight of 500 g was applied for 10 seconds, and the number of times of bending until cracks were generated on the surface of the cured coating film was measured. The evaluation is as follows.
Bend 5 times or more ◎
Bend 2 times or more ○
Bend less than 2 times ×

The test results for Test Examples 1 to 3 above are shown in Table 2 below.

Claims (10)

1. (A) An alkali-soluble resin having at least one of a bisphenol A structure, a bisphenol F structure, and a urethane structure,
   (B) Photopolymerization initiator and
   (C) An epoxy resin having an isocyanurate structure and
   A curable composition containing
   The epoxy resin having the (C) isocyanurate structure has a structure in which a nitrogen atom and an epoxy group in the isocyanurate structure are bonded by an alkylene chain having 2 or more carbon atoms.
   The curable composition.
2. The curable composition according to claim 1, further containing a powder or a crystalline epoxy resin.
3. The curable composition according to claim 2, wherein the powder or crystalline epoxy resin is an epoxy resin having a biphenyl structure.
4. The curable composition according to any one of claims 1 to 3, further containing an epoxy resin having a dicyclopentadiene structure.
5. The mass ratio of the epoxy resin having the (C) isocyanurate structure, the powdery or crystalline epoxy resin, and the epoxy resin having a dicyclopentadiene structure is 1: 2 to 6: 1 to 3. The curable composition according to claim 4.
6. The curable composition according to any one of claims 1 to 5, further containing urethane beads and / or epoxidized polybutadiene.
7. The curable composition according to any one of claims 1 to 6, further containing a cellulose resin.
8. A dry film having a resin layer obtained from the curable composition according to any one of claims 1 to 7.
9. A cured product obtained by curing the resin layer of the curable composition according to any one of claims 1 to 7 or the dry film according to claim 8.
10. An electronic component having the cured product according to claim 9.