JP7227016B2 - Photocurable resin composition for electronic devices - Google Patents

Description

TECHNICAL FIELD The present invention relates to a photocurable resin composition for electronic devices, which has excellent coatability and curability and a low dielectric constant.

In recent years, as a curable resin composition for electronic devices used in touch panel adhesives, solder resists for circuit boards, etc., there has been a demand for materials that have moderate viscosity, excellent coating properties, and photocurability. there is

Touch panels are used in electronic devices such as mobile phones, smart phones, car navigation systems, and personal computers. Among them, capacitive touch panels are rapidly becoming popular due to their excellent functionality.
A capacitive touch panel is generally configured by laminating a cover panel, an adhesive layer, and a substrate. The adhesive layer is required to have excellent transparency and adhesion to adherends. As such an adhesive layer, for example, Patent Document 1 discloses an adhesive layer containing a (meth)acrylic polymer obtained by polymerizing a specific monomer component.

On the other hand, a circuit board generally has a circuit with a wiring pattern formed on a base material made of an insulating material, and the outermost surface is a protective film called a solder resist for the purpose of protecting the circuit and insulating it from the outside of the circuit. is covered with In addition, by using a solder resist, it is possible to prevent solder bridges, which are short-circuits caused by solder adhering between wires when components are mounted or connections are made to external wires. For solder resists, for example, as disclosed in Patent Document 2, a curable resin composition having photosensitivity is used to form a pattern.

JP 2014-034655 A JP-A-08-259663

In recent years, as capacitive touch panels have become thinner and larger, the curable resin composition used for the above-described adhesive layer has a low dielectric constant and a low It is required to have dielectric properties such as dielectric loss tangent.
On the other hand, the curable resin used in the curable resin composition as disclosed in Patent Document 2 has a polar group such as an acid group to impart photosensitivity, and therefore has a high dielectric constant and dielectric loss tangent. As a result, when a high-frequency voltage is applied to the circuit, there is a problem that transmission delay or signal loss occurs. As a method for easily and efficiently forming a fine solder resist pattern, a method of forming a solder resist pattern by a printing method has been used. There is a problem that it is difficult to lower the dielectric constant and the dielectric loss tangent when the coating property is suitable for the system.
An object of the present invention is to provide a photocurable resin composition for electronic devices that is excellent in coatability and curability and has a low dielectric constant.

The present invention is a photocurable resin composition for electronic devices containing a curable resin and a polymerization initiator, wherein the curable resin comprises a monofunctional polymerizable compound and a polyfunctional cationic polymerizable compound, The monofunctional polymerizable compound includes a monofunctional polymerizable compound having an optionally substituted dicyclopentenyl group, a monofunctional polymerizable compound having an optionally substituted dicyclopentanyl group, and a substituted A photocurable electronic device containing at least one selected from the group consisting of monofunctional polymerizable compounds having a norbornenyl group, and having a dielectric constant of 3.5 or less measured at 25° C. and 100 kHz. It is a resin composition.
The present invention will be described in detail below.

The present inventors have found that by using a combination of a monofunctional polymerizable compound having a specific structure and a polyfunctional cationically polymerizable compound as a curable resin, excellent applicability and curability and a low dielectric constant The inventors have found that a photocurable resin composition for an electronic device having

The photocurable resin composition for electronic devices of the present invention contains a curable resin.
The curable resin contains a monofunctional polymerizable compound.
The monofunctional polymerizable compound includes a monofunctional polymerizable compound having an optionally substituted dicyclopentenyl group, a monofunctional polymerizable compound having an optionally substituted dicyclopentanyl group, and a substituted at least one selected from the group consisting of monofunctional polymerizable compounds having a norbornenyl group. Hereinafter, the monofunctional polymerizable compound having an optionally substituted dicyclopentenyl group is also referred to as "dicyclopentenyl group-containing monofunctional polymerizable compound". Moreover, hereinafter, the monofunctional polymerizable compound having an optionally substituted dicyclopentanyl group is also referred to as "dicyclopentanyl group-containing monofunctional polymerizable compound". Furthermore, hereinafter, the above monofunctional polymerizable compound having an optionally substituted norbornenyl group is also referred to as a "norbornenyl group-containing monofunctional polymerizable compound". Containing at least one selected from the group consisting of the dicyclopentenyl group-containing monofunctional polymerizable compound, the dicyclopentenyl group-containing monofunctional polymerizable compound, and the norbornenyl group-containing monofunctional polymerizable compound Therefore, the photocurable resin composition for electronic devices of the present invention has excellent coatability and a low dielectric constant.

The monofunctional polymerizable compound has one cationically polymerizable group in one molecule or one radically polymerizable group in one molecule.
Examples of the cationically polymerizable group possessed by the monofunctional polymerizable compound include an epoxy group, an oxetanyl group, and a vinyl ether group. Examples of the radically polymerizable group include an acryloyl group, a methacryloyl group, a vinyl group, and an allyl group. etc. Among them, an epoxy group, an oxetanyl group, and an acryloyl group are preferable.

The monofunctional polymerizable compound, specifically, a compound represented by the following formula (1-1), a compound represented by the following formula (1-2), a compound represented by the following formula (1-3) compounds, compounds represented by the following formula (1-4), compounds represented by the following formula (1-5), compounds represented by the following formula (1-6), and the following formula (1-7) It is preferable to include at least one selected from the group consisting of compounds represented by.

A preferable lower limit of the content of the monofunctional polymerizable compound in 100 parts by weight of the curable resin is 20 parts by weight, and a preferable upper limit is 90 parts by weight. When the content of the monofunctional polymerizable compound is within this range, the resulting photocurable resin composition for electronic devices maintains excellent curability, is more excellent in coatability, and has a higher dielectric constant. be low. A more preferable lower limit for the content of the monofunctional polymerizable compound is 30 parts by weight, and a more preferable upper limit is 70 parts by weight.

The curable resin contains a polyfunctional cationic polymerizable compound.
By containing the polyfunctional cationically polymerizable compound, the photocurable resin composition for electronic devices of the present invention has excellent curability.

The polyfunctional cationically polymerizable compound has two or more cationically polymerizable groups in one molecule.
Examples of the cationically polymerizable group possessed by the polyfunctional cationically polymerizable compound include those similar to the cationically polymerizable group possessed by the monofunctional polymerizable compound described above. Among them, an epoxy group and an oxetanyl group are preferable.

The polyfunctional cationically polymerizable compound is such that the resulting photocurable resin composition for electronic devices maintains a low dielectric constant and exhibits excellent curability. It preferably contains at least one selected from the group consisting of aliphatic glycidyl ether compounds and polyfunctional oxetane compounds.

The polyfunctional alicyclic epoxy compound has an alicyclic epoxy group.
The polyfunctional alicyclic epoxy compound may have two or more alicyclic epoxy groups in one molecule, or one alicyclic epoxy group and one or more It may have a non-alicyclic epoxy group.
An epoxy cyclohexyl group etc. are mentioned as said alicyclic epoxy group.

Specific examples of the polyfunctional alicyclic epoxy compound include compounds represented by the following formula (2-1), compounds represented by the following formula (2-2), and formula (2-3) below. a compound represented by the following formula (2-4), 1,2,8,9-diepoxylimonene, both terminal alicyclic epoxy-modified silicone oil, side chain type alicyclic epoxy-modified silicone oil and the like. Among them, the compound represented by the following formula (2-1), the compound represented by the following formula (2-2), the compound represented by the following formula (2-3), and the following formula (2-4 ) is preferably at least one selected from the group consisting of compounds represented by the following formula (2-1), more preferably a compound represented by the following formula (2-1), 3,4,3',4'-diepoxybicyclohexane is More preferred.

In formula (2-1), R ¹ to R ¹⁸ are a hydrogen atom, a halogen atom, an oxygen atom, a hydrocarbon group optionally having an oxygen atom or a halogen atom, or even having a substituent represents a good alkoxy group, which may be the same or different.
In formula (2-2), R ¹⁹ to R ³⁰ are a hydrogen atom, a halogen atom, an oxygen atom, a hydrocarbon group optionally having an oxygen atom or a halogen atom, or even having a substituent represents a good alkoxy group, which may be the same or different.
In formula (2-3), R ³¹ to R ⁴⁸ are a hydrogen atom, a halogen atom, an oxygen atom, a hydrocarbon group optionally having an oxygen atom or a halogen atom, or even having a substituent represents a good alkoxy group, which may be the same or different.
In formula (2-4), R ⁴⁹ to R ⁶⁶ are a hydrogen atom, a halogen atom, an oxygen atom, a hydrocarbon group optionally having an oxygen atom or a halogen atom, or even having a substituent represents a good alkoxy group, which may be the same or different.

A compound represented by the above formula (2-1), a compound represented by the above formula (2-2), a compound represented by the above formula (2-3), and a compound represented by the above formula (2-4) The compound can be produced, for example, by the methods disclosed in Japanese Patent No. 5226162, Japanese Patent No. 5979631, and the like.

Among the compounds represented by the above formula (2-1), commercially available compounds include, for example, Celoxide 8000 (manufactured by Daicel).
Among the compounds represented by the above formula (2-2), commercially available ones include, for example, THI-DE (manufactured by JXTG Nippon Oil & Energy Corporation).
Among the compounds represented by the above formula (2-3), commercially available compounds include, for example, DE-102 (manufactured by JXTG Nippon Oil & Energy Corporation).
Among the compounds represented by the above formula (2-4), commercially available compounds include, for example, DE-103 (manufactured by JXTG Nippon Oil & Energy Corporation).

Examples of the both-terminal alicyclic epoxy-modified silicone oil include compounds represented by the following formula (3).
Examples of the side chain type alicyclic epoxy-modified silicone oil include compounds represented by the following formula (4).

In formula (3), R ⁶⁷ each independently represents an alkyl group having 1 to 10 carbon atoms, R ⁶⁸ each independently represents a bond or an alkylene group having 1 to 6 carbon atoms, n represents an integer of 0 or more and 1000 or less.

In formula (4), R ⁶⁹ each independently represents an alkyl group having 1 to 10 carbon atoms, R ⁷⁰ represents a bond or an alkylene group having 1 to 6 carbon atoms, and R ⁷¹ is each It independently represents an alkyl group having 1 to 10 carbon atoms, or a group represented by the following formula (5-1) or (5-2). l represents an integer of 0 or more and 1000 or less, and m represents an integer of 1 or more and 100 or less. However, when all of R ⁷¹ are alkyl groups having 1 to 10 carbon atoms, m represents an integer of 2 to 100.

In formulas (5-1) and (5-2), R ⁷² represents a bond or an alkylene group having 1 to 6 carbon atoms, and * represents a bonding position.

The polyfunctional aliphatic glycidyl ether compound has an aliphatic skeleton.
The polyfunctional aliphatic glycidyl ether compound may have only a linear or branched aliphatic skeleton as the aliphatic skeleton, or may have a cyclic aliphatic skeleton. good.

Specific examples of the polyfunctional aliphatic glycidyl ether compound include 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, tricyclodecanediol diglycidyl ether, and the like. mentioned.

Specific examples of the polyfunctional oxetane compound include 3-ethyl-3-(((3-ethyloxetane-3-yl)methoxy)methyl)oxetane, 1,4-bis(((3-ethyloxetane -3-yl)methoxy)methyl)benzene, bis((3-ethyloxetan-3-yl)methyl) isophthalate, and the like.

A preferable lower limit of the content of the polyfunctional cationically polymerizable compound in 100 parts by weight of the curable resin is 10 parts by weight, and a preferable upper limit is 80 parts by weight. When the content of the polyfunctional cationically polymerizable compound is within this range, the obtained photocurable resin composition for electronic devices maintains excellent coatability and a low dielectric constant, and has excellent curability. . A more preferable lower limit to the content of the polyfunctional cationic polymerizable compound is 30 parts by weight, and a more preferable upper limit is 70 parts by weight.

The weight ratio of the monofunctional polymerizable compound to the polyfunctional cationically polymerizable compound (monofunctional polymerizable compound:polyfunctional cationically polymerizable compound) is preferably from 3:7 to 7:3. When the ratio of the monofunctional polymerizable compound and the polyfunctional cationic polymer compound is within this range, it becomes easy to achieve both high reliability and low dielectric constant, and the resin composition is superior as an electronic device resin composition. become. More preferably, the ratio of the monofunctional polymerizable compound to the polyfunctional cationically polymerizable compound is 4:6 to 6:4.

The curable resin, in addition to the monofunctional polymerizable compound and the polyfunctional cationic polymerizable compound, for the purpose of improving the coating properties by adjusting the viscosity within a range that does not impede the object of the present invention. It may contain a resin.
Examples of the other curable resins include (meth)acrylic compounds.
In the present specification, the above-mentioned "(meth)acrylic" means acrylic or methacrylic, "(meth)acrylic compound" means a compound having a (meth)acryloyl group, and "(meth)acryloyl ” means acryloyl or methacryloyl.

Examples of the (meth)acrylic compound include glycidyl (meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dicyclopentenyl (meth)acrylate, di Cyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, benzyl (meth)acrylate, trimethylolpropane tri(meth)arylate, 1,12-dodecanediol di(meth)acrylate, lauryl (meth)acrylate , (meth)acrylic modified silicone oil and the like.
These (meth)acrylic compounds may be used alone, or two or more of them may be used in combination.
In addition, in this specification, the above-mentioned "(meth)acrylate" means acrylate or methacrylate.

A preferable lower limit of the content of the other curable resin in 100 parts by weight of the curable resin is 5 parts by weight, and a preferable upper limit thereof is 30 parts by weight. When the content of the other curable resins is within this range, the resulting photocurable resin composition for electronic devices does not deteriorate the dielectric properties, etc., and is excellent in effects such as improved coatability. Become. A more preferable lower limit of the content of the other curable resin is 10 parts by weight, and a more preferable upper limit thereof is 20 parts by weight.

The photocurable resin composition for electronic devices of the present invention contains a polymerization initiator.
A photocationic polymerization initiator is preferably used as the polymerization initiator. Moreover, when containing the said (meth)acrylic resin as said other hardening resin, you may use together the said photocationic polymerization initiator and the photoradical polymerization initiator as said polymerization initiator. Furthermore, a thermal cationic polymerization initiator or a thermal radical polymerization initiator may be used as long as the object of the present invention is not impaired.

The photocationic polymerization initiator is not particularly limited as long as it generates a protonic acid or a Lewis acid by light irradiation, and may be an ionic photoacid-generating type or a nonionic photoacid-generating type. may

Examples of the anion portion of the ionic photoacid-generating photocationic polymerization initiator include BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , (BX ₄ ) ⁻ (wherein X is at least two or more fluorine or a phenyl group substituted with a trifluoromethyl group). Examples of the anion moiety include PF _m (C _n F _2n+1 ) _6-m ⁻ (where m is an integer of 0 or more and 5 or less and n is an integer of 1 or more and 6 or less).
Examples of the ionic photoacid-generating photocationic polymerization initiator include aromatic sulfonium salts, aromatic iodonium salts, aromatic diazonium salts, aromatic ammonium salts, (2,4-cyclo pentadien-1-yl)((1-methylethyl)benzene)-Fe salts and the like.

Examples of the aromatic sulfonium salts include bis(4-(diphenylsulfonio)phenyl)sulfide bishexafluorophosphate, bis(4-(diphenylsulfonio)phenyl)sulfide bishexafluoroantimonate, bis(4-( diphenylsulfonio)phenyl)sulfide bistetrafluoroborate, bis(4-(diphenylsulfonio)phenyl)sulfidetetrakis(pentafluorophenyl)borate, diphenyl-4-(phenylthio)phenylsulfonium hexafluorophosphate, diphenyl-4-( phenylthio)phenylsulfonium hexafluoroantimonate, diphenyl-4-(phenylthio)phenylsulfonium tetrafluoroborate, diphenyl-4-(phenylthio)phenylsulfonium tetrakis(pentafluorophenyl)borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexa fluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide bishexafluorophosphate, Bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide bishexafluoroantimonate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl ) sulfide bistetrafluoroborate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide tetrakis(pentafluorophenyl)borate, tris(4-(4-acetylphenyl)thiophenyl) sulfonium tetrakis(pentafluorophenyl)borate and the like.

Examples of the aromatic iodonium salts include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis(pentafluorophenyl)borate, bis(dodecylphenyl)iodonium hexafluorophosphate, bis (dodecylphenyl)iodonium hexafluoroantimonate, bis(dodecylphenyl)iodonium tetrafluoroborate, bis(dodecylphenyl)iodonium tetrakis(pentafluorophenyl)borate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium hexa fluorophosphate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium hexafluoroantimonate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium tetrafluoroborate, 4-methylphenyl-4-( 1-methylethyl)phenyliodonium tetrakis(pentafluorophenyl)borate and the like.

Examples of the aromatic diazonium salts include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis(pentafluorophenyl)borate.

Examples of the aromatic ammonium salts include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2-cyanopyridinium tetrafluoroborate, 1-benzyl -2-cyanopyridinium tetrakis(pentafluorophenyl)borate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluorophosphate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluoroantimonate, 1-(naphthylmethyl) -2-cyanopyridinium tetrafluoroborate, 1-(naphthylmethyl)-2-cyanopyridinium tetrakis(pentafluorophenyl)borate and the like.

Examples of the (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe salt include (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene )-Fe(II) hexafluorophosphate, (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe(II) hexafluoroantimonate, (2,4-cyclopentadiene-1 -yl)((1-methylethyl)benzene)-Fe(II) tetrafluoroborate, (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe(II) tetrakis(penta fluorophenyl)borate and the like.

Examples of the nonionic photoacid-generating photocationic polymerization initiator include nitrobenzyl esters, sulfonic acid derivatives, phosphoric acid esters, phenolsulfonic acid esters, diazonaphthoquinone, and N-hydroxyimide sulfonates.

Examples of commercially available photocationic polymerization initiators include, for example, a photocationic polymerization initiator manufactured by Midori Chemical Co., Ltd., a photocationic polymerization initiator manufactured by Union Carbide, a photocationic polymerization initiator manufactured by ADEKA, A photocationic polymerization initiator manufactured by 3M, a photocationic polymerization initiator manufactured by BASF, a photocationic polymerization initiator manufactured by Rhodia, and the like can be mentioned.
Examples of the photocationic polymerization initiator manufactured by Midori Kagaku Co., Ltd. include DTS-200 and the like.
Examples of photo cationic polymerization initiators manufactured by Union Carbide include UVI6990 and UVI6974.
Examples of photo cationic polymerization initiators manufactured by ADEKA include SP-150 and SP-170.
Examples of photo cationic polymerization initiators manufactured by 3M include FC-508 and FC-512.
Examples of photo cationic polymerization initiators manufactured by BASF include IRGACURE261 and IRGACURE290.
Examples of the photo cationic polymerization initiator manufactured by Rhodia include PI2074.

Examples of the radical photopolymerization initiator include benzophenone-based compounds, acetophenone-based compounds, acylphosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin ether-based compounds, benzyl, and thioxanthone-based compounds.

Examples of commercially available radical photopolymerization initiators include radical photopolymerization initiators manufactured by BASF Corporation and radical photopolymerization initiators manufactured by Tokyo Chemical Industry Co., Ltd.
Examples of photoradical polymerization initiators manufactured by BASF include IRGACURE 184, IRGACURE 369, IRGACURE 379, IRGACURE 651, IRGACURE 819, IRGACURE 907, IRGACURE 2959, IRGACURE OXE01, and Lucirin TPO.
Examples of the radical photopolymerization initiator manufactured by Tokyo Kasei Kogyo Co., Ltd. include benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether.

The thermal cationic polymerization initiator has an anion moiety of BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , or (BX ₄ ) ⁻ (where X is substituted with at least two fluorine or trifluoromethyl groups). sulfonium salts, phosphonium salts, ammonium salts, etc., composed of a phenyl group represented by a phenyl group. Among them, sulfonium salts and ammonium salts are preferred.

Examples of the sulfonium salt include triphenylsulfonium tetrafluoroborate and triphenylsulfonium hexafluoroantimonate.

Examples of the phosphonium salts include ethyltriphenylphosphonium hexafluoroantimonate and tetrabutylphosphonium hexafluoroantimonate.

Examples of the ammonium salts include dimethylphenyl(4-methoxybenzyl)ammonium hexafluorophosphate, dimethylphenyl(4-methoxybenzyl)ammonium hexafluoroantimonate, dimethylphenyl(4-methoxybenzyl)ammonium tetrakis(pentafluorophenyl) Borate, dimethylphenyl(4-methylbenzyl)ammonium hexafluorophosphate, dimethylphenyl(4-methylbenzyl)ammonium hexafluoroantimonate, dimethylphenyl(4-methylbenzyl)ammonium hexafluorotetrakis(pentafluorophenyl)borate, methylphenyl Dibenzylammonium hexafluorophosphate, methylphenyldibenzylammonium hexafluoroantimonate, methylphenyldibenzylammonium tetrakis(pentafluorophenyl)borate, phenyltribenzylammonium tetrakis(pentafluorophenyl)borate, dimethylphenyl(3,4-dimethyl) benzyl)ammonium tetrakis(pentafluorophenyl)borate, N,N-dimethyl-N-benzylanilinium hexafluoroantimonate, N,N-diethyl-N-benzylanilinium tetrafluoroborate, N,N-dimethyl-N- benzylpyridinium hexafluoroantimonate, N,N-diethyl-N-benzylpyridinium trifluoromethanesulfonic acid and the like.

Examples of commercially available thermal cationic polymerization initiators include thermal cationic polymerization initiators manufactured by Sanshin Chemical Industry Co., Ltd., and thermal cationic polymerization initiators manufactured by King Industries.
Examples of the thermal cationic polymerization initiator manufactured by Sanshin Chemical Industry include San-Aid SI-60, San-Aid SI-80, San-Aid SI-B3, San-Aid SI-B3A, and San-Aid SI-B4.
Examples of the thermal cationic polymerization initiator manufactured by King Industries include CXC1612 and CXC1821.

Examples of the thermal radical polymerization initiator include those composed of azo compounds, organic peroxides, and the like.
Examples of the azo compounds include 2,2′-azobis(2,4-dimethylvaleronitrile), azobisisobutyronitrile and the like.
Examples of the organic peroxide include benzoyl peroxide, ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, peroxyester, diacyl peroxide, and peroxydicarbonate.

Examples of commercially available thermal radical polymerization initiators include VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001, and V-501 (all of which are manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.). made) and the like.

The content of the polymerization initiator has a preferable lower limit of 0.01 parts by weight and a preferable upper limit of 10 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the polymerization initiator is 0.01 parts by weight or more, the obtained photocurable resin composition for electronic devices has excellent curability. When the content of the polymerization initiator is 10 parts by weight or less, the curing reaction of the obtained photocurable resin composition for electronic devices does not become too fast, the workability is improved, and the cured product is more uniform. can be A more preferable lower limit to the content of the polymerization initiator is 0.05 parts by weight, and a more preferable upper limit is 5 parts by weight.

The photocurable resin composition for electronic devices of the present invention may contain a sensitizer or a sensitizing aid. The sensitizer or sensitizing aid serves to further improve the polymerization initiation efficiency of the polymerization initiator and further accelerate the curing reaction of the photocurable resin composition for electronic devices of the present invention.

Examples of the sensitizer include thioxanthone compounds, 2,2-dimethoxy-1,2-diphenylethan-1-one, benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4 '-bis(dimethylamino)benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide and the like.
Examples of the thioxanthone compounds include 2,4-diethylthioxanthone.

The content of the sensitizer has a preferred lower limit of 0.01 parts by weight and a preferred upper limit of 3 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the sensitizer is 0.01 parts by weight or more, the sensitizing effect is exhibited more. When the content of the sensitizer is 3 parts by weight or less, light can be transmitted to a deep portion without excessive absorption. A more preferable lower limit of the content of the sensitizer is 0.1 part by weight, and a more preferable upper limit is 1 part by weight.

The photocurable resin composition for electronic devices of the present invention may contain a thermosetting agent within a range not impairing the object of the present invention.
Examples of the heat curing agent include hydrazide compounds, imidazole derivatives, acid anhydrides, dicyandiamide, guanidine derivatives, modified aliphatic polyamines, addition products of various amines and epoxy resins, and the like.
Examples of the hydrazide compound include 1,3-bis(hydrazinocarbonoethyl)-5-isopropylhydantoin, dihydrazide sebacate, dihydrazide isophthalate, dihydrazide adipic acid, and dihydrazide malonate.
Examples of the imidazole derivative include 1-cyanoethyl-2-phenylimidazole, N-(2-(2-methyl-1-imidazolyl)ethyl)urea, 2,4-diamino-6-(2'-methylimidazolyl- (1′))-ethyl-s-triazine, N,N′-bis(2-methyl-1-imidazolylethyl)urea, N,N′-(2-methyl-1-imidazolylethyl)-adipamide, 2- phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole and the like.
Examples of the acid anhydride include tetrahydrophthalic anhydride and ethylene glycol bis(anhydrotrimellitate).
These thermosetting agents may be used alone or in combination of two or more.

Examples of commercially available thermosetting agents include thermosetting agents manufactured by Otsuka Chemical Co., Ltd., and thermosetting agents manufactured by Ajinomoto Fine-Techno Co., Ltd.
Examples of the thermosetting agent manufactured by Otsuka Chemical Co., Ltd. include SDH and ADH.
Examples of the thermosetting agent manufactured by Ajinomoto Fine-Techno Co., Inc. include Amicure VDH, Amicure VDH-J, and Amicure UDH.

The content of the thermosetting agent has a preferable lower limit of 0.5 parts by weight and a preferable upper limit of 30 parts by weight with respect to 100 parts by weight of the polymerizable compound. When the content of the thermosetting agent is within this range, the resulting photocurable resin composition for electronic devices has excellent thermosetting properties while maintaining excellent storage stability. A more preferable lower limit to the content of the thermosetting agent is 1 part by weight, and a more preferable upper limit is 15 parts by weight.

The photocurable resin composition for electronic devices of the present invention may further contain a silane coupling agent. The silane coupling agent serves to improve the adhesiveness between the photocurable resin composition for electronic devices of the present invention and a substrate or the like.

Examples of the silane coupling agent include 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane and the like. These silane compounds may be used alone, or two or more of them may be used in combination.

The content of the silane coupling agent has a preferable lower limit of 0.1 parts by weight and a preferable upper limit of 10 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the silane coupling agent is within this range, the effect of improving the adhesiveness of the obtained photocurable resin composition for electronic devices while suppressing bleed-out due to excess silane coupling agent is excellent. become a thing. A more preferable lower limit for the content of the silane coupling agent is 0.5 parts by weight, and a more preferable upper limit is 5 parts by weight.

The photocurable resin composition for electronic devices of the present invention may contain a curing retardant. By containing the curing retarder, the pot life of the resulting photocurable resin composition for electronic devices can be lengthened.

Examples of the curing retarder include polyether compounds.
Examples of the polyether compounds include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, crown ether compounds, and the like. Among them, crown ether compounds are preferred.

The content of the curing retarder has a preferable lower limit of 0.05 parts by weight and a preferable upper limit of 5.0 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the curing retarder is within this range, the retardation effect can be exhibited more effectively while suppressing the generation of outgas when curing the obtained photocurable resin composition for electronic devices. A more preferred lower limit to the content of the curing retarder is 0.1 parts by weight, and a more preferred upper limit is 3.0 parts by weight.

The photocurable resin composition for electronic devices of the present invention may further contain a surface modifier within a range not impairing the object of the present invention. By containing the surface modifier, the photocurable resin composition for electronic devices of the present invention can be imparted with flatness of the coating film.
Examples of the surface modifier include surfactants and leveling agents.

Examples of the surface modifier include silicone-based, acrylic-based, and fluorine-based agents.
Examples of commercially available surface modifiers include surface modifiers manufactured by BYK-Chemie Japan and surface modifiers manufactured by AGC Seimi Chemical.
Examples of the surface modifier manufactured by BYK-Chemie Japan include BYK-340 and BYK-345.
Examples of the surface modifier manufactured by AGC Seimi Chemical Co., Ltd. include Surflon S-611.

The photocurable resin composition for electronic devices of the present invention may contain a compound that reacts with the acid generated in the composition or an ion-exchange resin, as long as the object of the present invention is not impaired.

The compound that reacts with the acid generated in the composition includes substances that neutralize the acid, such as alkali metal or alkaline earth metal carbonates or hydrogen carbonates. Specifically, for example, calcium carbonate, calcium hydrogencarbonate, sodium carbonate, sodium hydrogencarbonate and the like are used.

As the ion exchange resin, any of a cation exchange type, an anion exchange type, and an amphoteric ion exchange type can be used. is preferred.

In addition, the photocurable resin composition for electronic devices of the present invention, if necessary, contains various known additives such as reinforcing agents, softening agents, plasticizers, viscosity modifiers, ultraviolet absorbers, and antioxidants. You may

As a method for producing the photocurable resin composition for electronic devices of the present invention, for example, a curable resin is prepared using a mixer such as a homodisper, a homomixer, a universal mixer, a planetary mixer, a kneader, or a three-roll mixer. and a method of mixing a polymerization initiator and an additive such as a silane coupling agent to be added as necessary.

The photocurable resin composition for electronic devices of the present invention has an upper limit of dielectric constant of 3.5 measured at 25° C. and 100 kHz. Since the dielectric constant is 3.5 or less, the photocurable resin composition for electronic devices of the present invention is an adhesive for electronic devices such as an adhesive for touch panels and a solder resist for circuit boards, and a coating agent for electronic devices. etc. can be suitably used. A preferable upper limit of the dielectric constant is 3.3, and a more preferable upper limit is 3.0.
Although there is no particular lower limit for the dielectric constant, the practical lower limit is 2.2.
The "permittivity" can be measured using a permittivity measuring device.

The photocurable resin composition for electronic devices of the present invention can be suitably used for coating by an inkjet method.
The inkjet method may be a non-heated inkjet method or a heated inkjet method.
In this specification, the "non-heated inkjet method" is a method of inkjet coating at a coating head temperature of less than 28 ° C., and the "heated inkjet method" is a method of inkjet coating at a coating head temperature of 28 ° C. or higher. It is a method of coating.

An inkjet coating head equipped with a heating mechanism is used in the heating inkjet method. Since the inkjet coating head is equipped with a heating mechanism, the viscosity and surface tension can be reduced when the photocurable resin composition for electronic devices is discharged.

Examples of the inkjet coating head equipped with the heating mechanism include KM1024 series manufactured by Konica Minolta, SG1024 series manufactured by Fuji Film Dimatix, and the like.

When the photocurable resin composition for electronic devices of the present invention is used for coating by the thermal inkjet method, the heating temperature of the coating head is preferably in the range of 28°C to 80°C. When the heating temperature of the coating head is within this range, the increase in the viscosity of the photocurable resin composition for electronic devices over time is further suppressed, and the ejection stability becomes more excellent.

The photocurable resin composition for electronic devices of the present invention preferably has a lower limit of 5 mPa·s and a preferred upper limit of viscosity at 25° C. of 50 mPa·s. When the viscosity at 25°C is within this range, it can be suitably applied by an inkjet method.
A more preferable lower limit of the viscosity at 25° C. of the photocurable resin composition for electronic devices of the present invention is 8 mPa·s, and a still more preferable lower limit is 10 mPa·s. Further, a more preferable upper limit of the viscosity at 25° C. of the photocurable resin composition for electronic devices of the present invention is 40 mPa.s. s, and a more preferable upper limit is 30 mPa.s. is s.
In addition, the above-mentioned "viscosity" in this specification means the value measured on conditions of 25 degreeC and 100 rpm using an E-type viscometer. Examples of the E-type viscometer include VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.), and CP1-type cone plate can be used.

The photocurable resin composition for electronic devices of the present invention preferably has a surface tension at 25° C. of 15 mN/m as a lower limit and 35 mN/m as an upper limit. Since the surface tension at 25°C is within this range, it can be suitably applied by an inkjet method. A more preferable lower limit of the surface tension at 25° C. is 20 mN/m, a more preferable upper limit is 30 mN/m, a still more preferable lower limit is 22 mN/m, and a further preferable upper limit is 28 mN/m.
In addition, the said surface tension means the value measured by the Wilhelmy method with the dynamic wettability tester. Examples of the dynamic wettability tester include WET-6100 type (manufactured by Lesca).

The photocurable resin composition for electronic devices of the present invention can be suitably cured by irradiation with light having a wavelength of 300 nm or more and 400 nm or less and an integrated light amount of 300 mJ/cm ² or more and 3000 mJ/cm ² or less.

Examples of light sources used for light irradiation include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, excimer lasers, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, sodium lamps, halogen lamps, and xenon. lamps, LED lamps, fluorescent lamps, sunlight, electron beam irradiation devices, and the like. These light sources may be used alone or in combination of two or more.
These light sources are appropriately selected according to the absorption wavelength of the photo cationic polymerization initiator and the photo radical polymerization initiator.

Examples of means for irradiating the photocurable resin composition for an electronic device of the present invention with light include simultaneous irradiation with various light sources, sequential irradiation with a time lag, combined irradiation of simultaneous and sequential irradiation, and the like. , any irradiation means may be used.

The photocurable resin composition for electronic devices of the present invention is suitably used as adhesives for electronic devices such as adhesives for touch panels and solder resists for circuit boards, and coating agents for electronic devices. Moreover, the photocurable resin composition for electronic devices of the present invention is suitably used as a sealant for display elements such as organic EL display elements.

ADVANTAGE OF THE INVENTION According to this invention, the photocurable resin composition for electronic devices which is excellent in coatability and curability, and has a low dielectric constant can be provided.

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples.

(Examples 1 to 16, Comparative Examples 1 to 3)
According to the blending ratios described in Tables 1 to 3, each material was uniformly stirred and mixed at a stirring speed of 3000 rpm using a homodisper type stirring mixer to obtain the electrons of Examples 1 to 16 and Comparative Examples 1 to 3. A photocurable resin composition for devices was produced. As the homodisper type stirring mixer, Homodisper L type (manufactured by Primix) was used.
Each of the obtained photocurable resin compositions for electronic devices was applied on a PET film to a thickness of 100 μm, and cured by irradiating 3000 mJ/cm ² of ultraviolet rays of 395 nm using an LED UV lamp. As the LED UV lamp, SQ series (manufactured by Quark Technology Co., Ltd.) was used. After that, on both surfaces of the cured film, gold electrodes were vacuum-evaporated in a circular shape with a diameter of 2 cm and a thickness of 0.1 μm so as to face each other to prepare a test piece for measuring a dielectric constant. The dielectric constant of the obtained test piece was measured using a dielectric constant measuring device under the conditions of 25° C. and 100 kHz . A 1260 model impedance analyzer (manufactured by Solartron) and a 1296 model dielectric constant measurement interface (manufactured by Solartron) were used as the dielectric constant measuring device. The results are shown in Tables 1-3.

<Evaluation>
The photocurable resin compositions for electronic devices obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in Tables 1-3.

(1) Viscosity For each photocurable resin composition for electronic devices obtained in Examples and Comparative Examples, the viscosity was measured at 25°C and 100 rpm using a CP1 cone plate using an E-type viscometer. bottom. As the E-type viscometer, VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) was used.

(2) Applicability Each photocurable resin composition for electronic devices obtained in Examples and Comparative Examples was applied to an alkali-cleaned alkali-free glass using an inkjet printer, and a droplet size of 10 picoliters was applied to a thickness of 25 μm. A coating test was performed by printing in a grid pattern with a pitch. Material printer DMP-2831 (manufactured by Fuji Film Co., Ltd.) was used as the inkjet printer, and AN100 (manufactured by AGC Co.) was used as the alkali-free glass.
"○" indicates that the printed area was evenly printed without any uncoated areas or unevenness, "△" indicates that there were no uncoated areas but streak-like unevenness was observed, and "△" indicated that there were uncoated areas. The applicability was evaluated as "x".

(3) Curability Each photocurable resin composition for electronic devices obtained in Examples and Comparative Examples was cured by irradiating 3000 mJ/cm ² of ultraviolet rays of 395 nm using an LED UV lamp. As the LED UV lamp, SQ series (manufactured by Quark Technology Co., Ltd.) was used. The composition before curing and the cured product were subjected to FT-IR analysis using a Fourier transform infrared spectrophotometer. As a Fourier transform infrared spectrophotometer, iS-5 (manufactured by Nicolet) was used. In the case of epoxy groups, the reduction rate of the peak at 915 cm ^-1 after curing, and in the case of oxetanyl groups, the reduction rate of the peak at 980 cm ^-1 after curing was calculated as the curing rate (reaction rate of the cationically polymerizable group). bottom.
The curability was evaluated as "○" when the curing rate was 90% or more, "Δ" when it was 70% or more and less than 90%, and "X" when it was less than 70%.

(4) Reliability of organic EL display element (4-1) Fabrication of a substrate on which a laminate having an organic light-emitting material layer is arranged An ITO electrode of 1000 Å was placed on a glass having a length of 25 mm, a width of 25 mm and a thickness of 0.7 mm. A film was formed so as to have a thickness, and this was used as a substrate. After ultrasonically cleaning the substrate with acetone, an alkaline aqueous solution, deionized water, and isopropyl alcohol for 15 minutes each, the substrate is cleaned with boiled isopropyl alcohol for 10 minutes, and further treated immediately before with a UV-ozone cleaner. gone. NL-UV253 (manufactured by Nippon Laser Electronics Co., Ltd.) was used as the UV-ozone cleaner.
Next, the substrate after the previous treatment was fixed to a substrate holder of a vacuum deposition apparatus, and 200 mg of N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (α-NPD) was placed in an unglazed crucible. , 200 mg of tris(8-quinolinolato)aluminum (Alq ₃ ) was placed in another unglazed crucible, and the pressure in the vacuum chamber was reduced to 1×10 ⁻⁴ Pa. Then, the crucible containing α-NPD was heated to deposit α-NPD on the substrate at a deposition rate of 15 Å/s to form a hole transport layer with a film thickness of 600 Å. Next, the crucible containing Alq ₃ was heated, and an organic light-emitting material layer with a thickness of 600 Å was formed at a deposition rate of 15 Å/s. After that, the substrate on which the hole transport layer and the organic light emitting material layer are formed is transferred to another vacuum deposition apparatus having a tungsten resistance heating boat, and lithium fluoride is transferred to one of the tungsten resistance heating boats in the vacuum deposition apparatus. 200 mg was put, and 1.0 g of aluminum wire was put into another tungsten resistance heating boat. After that, the pressure inside the vapor deposition device of the vacuum deposition apparatus was reduced to 2×10 ⁻⁴ Pa, and after lithium fluoride was deposited at a deposition rate of 0.2 Å/s to form a 5 Å film, aluminum was deposited at a rate of 20 Å/s to form a 1000 Å film. bottom. The inside of the evaporator was returned to normal pressure with nitrogen, and the substrate on which the laminate having the organic light-emitting material layer of 10 mm×10 mm was arranged was taken out.

(4-2) Coating with Inorganic Material Film A A mask having an opening of 13 mm × 13 mm is placed on the substrate on which the obtained laminate is placed, and an inorganic material is applied so as to cover the entire laminate by plasma CVD. Membrane A was formed.
The plasma CVD method uses SiH ₄ gas and nitrogen gas as raw material gases, with flow rates of SiH ₄ gas of 10 sccm and nitrogen gas of 200 sccm, RF power of 10 W (frequency of 2.45 GHz), chamber temperature of 100 ° C., chamber It was carried out under the condition that the internal pressure was 0.9 Torr.
The thickness of the formed inorganic material film A was about 1 μm.

(4-3) Formation of Resin Protective Film Each sealant for organic EL display elements obtained in Examples and Comparative Examples was pattern-coated on the substrate by using an ink-jet ejection device. NanoPrinter 500 (manufactured by Microjet) was used as an inkjet ejection device.
After that, an LED lamp was used to irradiate 3000 mJ/cm ² of ultraviolet rays having a wavelength of 365 nm to cure the sealant for organic EL display elements, thereby forming a resin protective film.

(4-4) Coating with inorganic material film B After forming a resin protective film, a mask having an opening of 12 mm × 12 mm is placed, and an inorganic material film is formed by plasma CVD so as to cover the entire resin protective film. B was formed to obtain an organic EL display element.
The plasma CVD method was performed under the same conditions as in "(3-2) Coating with inorganic material film A" above.
The thickness of the formed inorganic material film B was about 1 μm.

(4-5) Luminescent state of organic EL display element After exposing the obtained organic EL display element in an environment with a temperature of 85° C. and a humidity of 85% for 100 hours, a voltage of 3 V is applied to the organic EL display element. The light emission state (whether or not there are dark spots and pixel peripheral quenching) was visually observed.
"○" indicates uniform emission without dark spots or peripheral extinction, "△" indicates slight decrease in luminance although there are no dark spots or peripheral extinction, and "△" indicates that dark spots or peripheral extinction is observed. The reliability of the organic EL display element was evaluated with "x".

ADVANTAGE OF THE INVENTION According to this invention, the photocurable resin composition for electronic devices which is excellent in coatability and curability, and has a low dielectric constant can be provided.

Claims (5)

A photocurable resin composition for an electronic device containing a curable resin and a polymerization initiator,
The curable resin contains a monofunctional polymerizable compound and a polyfunctional cationically polymerizable compound,
The monofunctional polymerizable compound includes a monofunctional polymerizable compound having an optionally substituted dicyclopentenyl group, a monofunctional polymerizable compound having an optionally substituted dicyclopentanyl group, and a substituted At least one selected from the group consisting of monofunctional polymerizable compounds having a norbornenyl group,
A photocurable resin composition for electronic devices, characterized by having a dielectric constant of 3.5 or less as measured at 25°C and 100 kHz. The monofunctional polymerizable compound includes a compound represented by the following formula (1-1), a compound represented by the following formula (1-2), a compound represented by the following formula (1-3), the following formula ( 1-4), a compound represented by the following formula (1-5), a compound represented by the following formula (1-6), and a compound represented by the following formula (1-7) 2. The photocurable resin composition for electronic devices according to claim 1, comprising at least one selected from the group consisting of:

3. The polyfunctional cationically polymerizable compound according to claim 1 or 2, comprising at least one selected from the group consisting of polyfunctional alicyclic epoxy compounds, polyfunctional aliphatic glycidyl ether compounds, and polyfunctional oxetane compounds. A photocurable resin composition for electronic devices. The polyfunctional cationically polymerizable compound includes a compound represented by the following formula (2-1), a compound represented by the following formula (2-2), a compound represented by the following formula (2-3), and 4. The photocurable resin composition for electronic devices according to claim 3, comprising at least one compound selected from the group consisting of compounds represented by the following formula (2-4).

In formula (2-1), R ¹ to R ¹⁸ are a hydrogen atom, a halogen atom, an oxygen atom, a hydrocarbon group optionally having an oxygen atom or a halogen atom, or even having a substituent represents a good alkoxy group, which may be the same or different.
In formula (2-2), R ¹⁹ to R ³⁰ are a hydrogen atom, a halogen atom, an oxygen atom, a hydrocarbon group optionally having an oxygen atom or a halogen atom, or even having a substituent represents a good alkoxy group, which may be the same or different.
In formula (2-3), R ³¹ to R ⁴⁸ are a hydrogen atom, a halogen atom, an oxygen atom, a hydrocarbon group optionally having an oxygen atom or a halogen atom, or even having a substituent represents a good alkoxy group, which may be the same or different.
In formula (2-4), R ⁴⁹ to R ⁶⁶ are a hydrogen atom, a halogen atom, an oxygen atom, a hydrocarbon group optionally having an oxygen atom or a halogen atom, or even having a substituent represents a good alkoxy group, which may be the same or different. 5. The photocurable resin composition for electronic devices according to claim 1, 2, 3, or 4, which has a viscosity of 5 mPa·s or more and 50 mPa·s or less measured under conditions of 25° C. and 100 rpm using an E-type viscometer. .