Curable resin composition, insulating cured film obtained by curing said composition, and display device comprising said insulating cured film

Abstract

This curable resin composition contains an alkali-soluble resin (A), a (meth)acrylic monomer (B) having two or more polymerizable functional groups and an ionic liquid (C).

Description

Curable resin composition, insulating cured film obtained by curing the composition, and display device including the insulating cured film

[0001] The present invention relates to a curable resin composition and an insulating cured film obtained by curing the composition. The present invention relates to a curable resin composition that is useful for forming an insulating cured film (e.g., an insulating film, a protective film, a planarizing film, etc.) included in a liquid crystal panel or a touch panel that constitutes a display device such as a liquid crystal display or a touch panel display, as well as an insulating cured film obtained by curing the composition, and a display device including the cured film.

[0002] In recent years, as electronic devices have become more sophisticated, diverse, and smaller and lighter, touch panel displays equipped with a display device such as a liquid crystal panel and a transparent touch panel have come into use. In touch panel displays, characters, symbols, pictures, etc. displayed on the display device such as a liquid crystal panel are viewed and selected through a touch panel (touch sensor), and various functions of the device are switched by operating the touch panel.

[0003] Touch panel displays can be classified into out-cell, on-cell, and in-cell structures depending on their structure, and in recent years, the on-cell and in-cell structures, which offer excellent visibility, have become mainstream. The on-cell structure places the touch panel inside the polarizing plate of the liquid crystal panel, while the in-cell structure incorporates the touch panel into the liquid crystal panel.

[0004] Generally, insulating films and other materials suitable for display devices are designed to have high resistance, which makes it difficult for static electricity generated when peeling off a protective film on the surface of a display device or when a person touches a liquid crystal panel to escape from the liquid crystal layer, making it easy for the display to malfunction.

[0005] Various efforts have been made to solve such problems. For example, in Patent Document 1, a liquid crystal display element having a surface resistivity of 10 is formed between an electrode layer and an alignment film formed on a pair of substrates, with the aim of providing a liquid crystal display element capable of quickly eliminating abnormal lighting caused by static electricity or the like. ７ Ω / □ to 10１０ The present invention discloses a liquid crystal display element having the following characteristics: an insulating film having a resistivity in the range of Ω / □ is provided, and the insulating film is composed of a conductive filler made of at least one material selected from the group consisting of antimony oxide, zinc oxide, tin oxide, and indium oxide.

[0006] Japanese Patent Application Laid-Open No. 2007-148136

[0007] Insulating members such as insulating films of display devices may be formed by lithography technology and disposed in required locations as insulating cured films. However, as described in the above-mentioned Patent Document 1, when the surface resistance of the insulating member is adjusted to a desired value by using conductive particles such as conductive fillers or carbon nanotubes, it has been found that lithography performance is reduced, making it difficult to form fine patterns.

[0008] In order to solve the above-mentioned problems, the present invention aims to provide a curable resin composition that can adjust the surface resistivity of the resulting insulating cured film to a desired range and that is excellent in the formability of fine patterns, an insulating cured film obtained by curing the composition, and an insulating cured film for a display device.

[0009] The present inventors conducted extensive research to solve the above-mentioned problems. As a result, they discovered that the above-mentioned problems can be achieved by using a curable resin composition containing an alkali-soluble resin, a specific (meth)acrylic monomer (B), and an ionic liquid (C), and thus completed the present invention. <1> A curable resin composition containing an alkali-soluble resin (A), a (meth)acrylic monomer (B) having two or more polymerizable functional groups, and an ionic liquid (C). <2> The curable resin composition according to <1>, in which the ionic liquid (C) has a melting point of 100°C or lower. <3> The curable resin composition according to <1> or <2>, in which the ionic liquid (C) has a polymerizable functional group. <4> The curable resin composition according to any one of <1> to <3>, in which the cation constituting the ionic liquid (C) includes at least one of a quaternary phosphonium cation and a quaternary ammonium cation. <5> The curable resin composition according to any one of <1> to <4>, wherein the alkali-soluble resin (A) has an acid group and a cyclic ether group. <6> The curable resin composition according to any one of <1> to <5>, wherein the alkali-soluble resin (A) is a thermosetting alkali-soluble resin A1 containing at least one of the following units (a1-1) and (a1-2): (In formula (a1-1), R １ represents a hydrogen atom or a methyl group; X １ represents a single bond or a linear or cyclic aliphatic hydrocarbon group having 1 to 15 carbon atoms which may contain an oxygen atom. １ represents a hydrogen atom or a methyl group; R ３ represents a linear or branched aliphatic hydrocarbon group having a cyclic ether structure and having 3 to 15 carbon atoms, which may contain an oxygen atom.) <7> The curable resin composition according to any one of <1> to <6>, wherein the alkali-soluble resin (A) further contains the following unit (a1-3): (In formula (a1-3), R １ represents a hydrogen atom or a methyl group; R ４represents at least one selected from a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 20 carbon atoms, which may contain an oxygen atom, an aromatic group, and a combination thereof.) <8> The curable resin composition according to any one of <1> to <7>, wherein the alkali-soluble resin (A) has a weight average molecular weight of 30,000 or less. <9> The curable resin composition according to any one of <1> to <8>, wherein the (meth)acrylic monomer (B) has three or more polymerizable functional groups. <10> The curable resin composition according to any one of <1> to <9>, wherein the (meth)acrylic monomer (B) contains at least one of the following formulae (b-1) and (b-2): (In formula (b-1), R １２ and R １３ each independently represents a hydrogen atom or a methyl group; Y １ and Y ２ each independently represents a single bond or a linear or branched aliphatic hydrocarbon group having 1 to 26 carbon atoms which may contain an oxygen atom; X １１ represents an aliphatic hydrocarbon group or aromatic group having a cyclic skeleton and having 6 to 26 carbon atoms; W １ and W ２ each independently represents O, N, or S. (In formula (b-2), R ６ ~R １１ represents a hydrogen atom, a methacryloyl group, an acryloyl group, or an organic group. ６ ~R １１ at least three of which are methacryloyl groups or acryloyl groups, and n is 0 to 10.) <11> The curable resin composition according to any one of <1> to <10>, wherein the mass ratio (A:B) of the total amount of the alkali-soluble resin (A) to the total amount of the (meth)acrylic monomer (B) is 100:40 to 80. <12> The curable resin composition according to any one of <1> to <11>, which is used for forming an insulating film. <13> An insulating cured film obtained by curing the curable resin composition according to any one of <1> to <11>. <14> A display device comprising the insulating cured film according to <13>.

[0010] According to the present invention, it is possible to provide a curable resin composition that provides an insulating cured film having excellent surface resistivity and excellent fine pattern formability, an insulating cured film obtained by curing the composition, and a display device including the insulating cured film.

[0011] It is a plan view showing the configuration of one mode of a touch panel included in the display device of the present embodiment. It is a cross-sectional view taken along the line AA in Fig. 1. It is a schematic view showing the cross-sectional shape of a through-hole.

[0012] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. However, the present invention is not limited to this embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0013] <<Curable Resin Composition>> The curable resin composition of the present embodiment contains an alkali-soluble resin (A), a (meth)acrylic monomer having two or more polymerizable functional groups (B), and an ionic liquid (C).

[0014] The curable resin composition of this embodiment may contain a conductive filler to the extent that the effects of the present invention are not impaired, but preferably does not contain a conductive filler. The conductive filler is not particularly limited as long as it is a filler that exhibits conductivity, and examples thereof include antimony oxide, tin oxide, indium oxide, and zinc oxide. The content of these conductive fillers is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass, and particularly preferably 0% by mass or less (excluding conductive fillers as optional components) based on the total solid content in the curable resin composition. Throughout this specification, the term "total solid content" refers to all components in the curable resin composition other than the solvent.

[0015] <Alkali-Soluble Resin (A)> The curable resin composition of this embodiment contains an alkali-soluble resin (A). "Alkali-soluble resin" refers to a resin in which the uncured portion is soluble in a developer and the cured portion is insoluble or poorly soluble in a developer. The alkali-soluble resin (A) may be either a thermosetting or photocurable alkali-soluble resin. Although not particularly limited, examples of thermosetting alkali-soluble resins include the thermosetting alkali-soluble resin (A1) described below. Furthermore, examples of photocurable alkali-soluble resins include the photocurable alkali-soluble resin (A2) described below. Note that, from the viewpoint of the resistance of the cured product to water penetration (hereinafter simply referred to as water resistance), it is preferable that the thermosetting alkali-soluble resin (A) has a cyclic group.

[0016] Hereinafter, the thermosetting alkali-soluble resin (A1) and the photocurable alkali-soluble resin (A2) may be referred to as the "alkali-soluble resin (A1)" and the "alkali-soluble resin (A2)", respectively. Furthermore, the alkali-soluble resins (A1) and (A2) may be collectively referred to as the "alkali-soluble resin (A)". The curable resin composition of this embodiment may contain a plurality of alkali-soluble resins (A1) and (A2).

[0017] <Thermosetting Alkali-Soluble Resin (A1)> The alkali-soluble resin (A1) is a resin that has a thermally reactive group and undergoes curing at 70°C or higher. The thermally reactive group is not particularly limited, but in terms of low-temperature curing properties, examples include acid groups (e.g., carboxyl groups, acid anhydride groups, sulfonic groups, and phosphate groups), cyclic ether groups, hydroxy groups, amino groups, thiol groups, isocyanate groups, and silanol groups. The alkali-soluble resin (A1) preferably has an acid group and a cyclic ether group (e.g., epoxy group, oxetanyl group, etc.) as the thermally reactive group. The temperature at which the curing of the thermosetting alkali-soluble resin (A1) proceeds varies depending on the type and number of thermally reactive groups, but from the viewpoints of low-temperature curing properties and the solubility of the unexposed area in a developer, it is preferably 70°C or higher, more preferably 80°C to 230°C, and particularly preferably 90°C to 150°C.

[0018] As the thermosetting alkali-soluble resin (A1), it is preferable to use a resin containing at least the following units (a1-1) and (a1-2). The thermosetting alkali-soluble resin (A1) may contain two or more types of the same structural unit (e.g., two types of units (a1-2)) shown below.

[0019] (unit (a1-1) or in, R １ represents a hydrogen atom or a methyl group; X １ represents a single bond or a linear or cyclic aliphatic hydrocarbon group having 1 to 15 carbon atoms which may contain an oxygen atom. １ represents a hydrogen atom or a methyl group; R ３ represents a linear or branched aliphatic hydrocarbon group having a cyclic ether structure and having 3 to 15 carbon atoms, which may contain an oxygen atom.

[0020] - Unit (a1-1) - The unit (a1-1) is a unit corresponding to an unsaturated carboxylic acid. In the unit (a1-1), R １ represents a hydrogen atom or a methyl group, and a methyl group is preferred from the viewpoint of water resistance of the resulting cured product. １ represents a single bond or a linear or cyclic aliphatic hydrocarbon group (divalent bonding group) having 1 to 15 carbon atoms which may contain an oxygen atom. From the viewpoint of water resistance, the carbon number of the aliphatic hydrocarbon group which may contain an oxygen atom is preferably 1 to 9. These aliphatic hydrocarbon groups may have an -O- structure (a structure containing an oxygen atom: for example, an ether group (-O-), an ester group (-CO-O-), or an acid anhydride group (-CO-O-CO-)) in the structure. Examples of linear aliphatic hydrocarbon groups include alkylene groups having 1 to 15 carbon atoms, and aliphatic hydrocarbon groups having 3 to 15 carbon atoms which may contain multiple ester groups or acid anhydride groups (-CO-O-CO-). Examples of cyclic aliphatic hydrocarbon groups include cycloalkylene groups having 3 to 15 carbon atoms, and cycloalkylene groups having 3 to 15 carbon atoms which may contain multiple ester groups or acid anhydride groups. In addition, X １X may be an aliphatic hydrocarbon group containing both a linear portion and a cyclic portion. X may be an aliphatic hydrocarbon group containing multiple ester groups or acid anhydride groups. １ Examples of the group include -CO-O-CH ２ -CH ２ —O—CO—CH ２ -CH ２ -, -CO-O-CH ２ -CH ２ —O—CO-cyclohexyl- and the like.

[0021] Examples of the unit (a1-1) include methacrylic acid (hereinafter sometimes referred to as "MAA"), acrylic acid, crotonic acid (trans), maleic acid (cis), fumaric acid (trans), citraconic acid (cis), mesaconic acid (trans), itaconic acid, maleic anhydride, citraconic anhydride, itaconic anhydride, and 2-methacryloyloxyethyl hexahydrophthalate. Preferred structures of the unit (a1-1) include units corresponding to the following compounds:

[0022]

[0023] - Unit (a1-2) - The unit (a1-2) is a unit corresponding to an unsaturated carboxylic acid having a cyclic ether structure. In the following unit (a1-2), R １ represents a hydrogen atom or a methyl group; R ３ represents a linear or branched aliphatic hydrocarbon group having a cyclic ether structure and having 3 to 15 carbon atoms which may contain an oxygen atom.

[0024]

[0025] In the unit (a1-2), R １ represents a hydrogen atom or a methyl group, and a methyl group is preferred from the viewpoint of water resistance. ３represents a linear or branched aliphatic hydrocarbon group having a cyclic ether structure and having 3 to 15 carbon atoms, which may contain an oxygen atom. Here, the number of carbon atoms in the linear or branched aliphatic hydrocarbon group having a cyclic ether structure is preferably 3 to 7, from the viewpoint of improving the ability to form a fine pattern (hereinafter referred to as "from the viewpoint of developability"). These aliphatic hydrocarbon groups may have an -O- structure (a structure containing an oxygen atom: for example, an ether group (-O-), an ester group (-CO-O-), or an acid anhydride group (-CO-O-CO-)) in the structure. Examples of linear or branched aliphatic hydrocarbon groups having a cyclic ether structure include groups in which a cyclic ether structure is bonded to the terminal of an alkylene group (for example, a methylene group). Preferred structures of the unit (a1-2) include units corresponding to the following compounds:

[0026]

[0027] - Unit (a1-3) - From the viewpoint of the resistance of the cured product to a developer (hereinafter simply referred to as developer resistance), the alkali-soluble thermosetting resin (A1) may be a resin containing the following unit (a1-3) in addition to the units (a1-1) and (a1-2) described above. The unit (a1-3) is a unit corresponding to an unsaturated compound.

[0028] (In the formula, R １ represents a hydrogen atom or a methyl group; R ４ represents at least one selected from a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 20 carbon atoms, which may contain an oxygen atom, an aromatic group, and a combination thereof.

[0029] In the unit (a1-3), R １ represents a hydrogen atom or a methyl group, and a methyl group is preferred from the viewpoint of water resistance. ４is a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aromatic group, or a combination of the aliphatic hydrocarbon and an aromatic group. Here, the number of carbon atoms in the aliphatic hydrocarbon group is preferably 1 to 10, from the viewpoints of resistance to a developer and developability. These aliphatic hydrocarbon groups may have an —O— structure (a structure containing an oxygen atom: for example, an ether group (—O—), an ester group (—CO—O—), or an acid anhydride group (—CO—O—CO—)) in the structure. Examples of the linear, branched, or cyclic aliphatic hydrocarbon group include linear, branched, or cyclic alkyl groups having 1 to 20 carbon atoms, and from the viewpoint of resistance to a developer, a methyl group, a normal propyl group, a normal butyl group, a normal hexyl group, a cyclopentyl group, a cyclohexyl group, an isobornyl group, a tricyclodecanyl group, and an adamantyl group are preferred. Examples of the aromatic group include a phenyl group, a biphenyl group, a naphthyl group, and an anthracenyl group, with a phenyl group being preferred from the viewpoint of the transparency of the cured product. Examples of combinations of an aliphatic hydrocarbon group having 1 to 20 carbon atoms with an aromatic group include an alkoxyphenyl group, an alkylphenyl group, an alkoxynaphthyl group, an alkylnaphthyl group, an alkoxyanthracenyl group, and an alkylanthracenyl group, with an alkoxyphenyl group and an alkylphenyl group being preferred from the viewpoint of the transparency of the cured product. Examples of preferred structures of the unit (a1-3) include units corresponding to the following compounds:

[0030]

[0031] —Constituent Ratio— In the alkali-soluble resin (A), the contents (mol %) of the units (a1-1), (a1-2), and (a1-3) are preferably (a1-1) / (a1-2) / (a1-3)=10 to 50 / 10 to 70 / 0 to 70, more preferably 15 to 40 / 15 to 60 / 15 to 65, and particularly preferably 15 to 30 / 20 to 50 / 30 to 60, from the viewpoints of resistance to a developer and developability.

[0032] —Other Structural Units— The alkali-soluble resin (A1) may contain other structural units that do not fall into any of the above-mentioned units (a1-1) to (a1-3). Examples of such other structural units include benzyl methacrylate, 1,3-bis(methacryloyloxy)-2-propanol, 2-methacryloyloxyethyl isocyanate, 2-hydroxyethyl methacrylate, and N-cyclohexyl succinimide.

[0033] (Specific Examples) Specific examples of the alkali-soluble resin (A) include the following polymers.

[0034]

[0035] (Acid Value) The acid value of the alkali-soluble resin (A1) is preferably 55 to 100 mgKOH / g, more preferably 60 to 95 mgKOH / g, and even more preferably 70 to 90 mgKOH / g. When the acid value of the alkali-soluble resin (A1) is within the range of 55 to 100 mgKOH / g, the occurrence of development defects can be suppressed, and the resistance to developers (e.g., tetramethylammonium hydroxide) is high, making it possible to suppress overdevelopment. Furthermore, when the acid value is less than 55 mgKOH / g, there is a risk of reduced developability. The theoretical solid content acid value can be used as the acid value of the alkali-soluble resin, and can be calculated as follows: Theoretical acid value of solids (mg KOH / g) = [56.1 (molecular weight of potassium hydroxide) × (total amount [g] of acid group-containing units in alkali-soluble resin (A1)) × 1000] / [(total amount [g] of solids of alkali-soluble resin (A1)) × (molecular weight of acid group-containing units)]

[0036] <Photocurable alkali-soluble resin (A2)> The alkali-soluble resin (A2) is a resin having photocurability. The alkali-soluble resin (A2) preferably has an ethylenically unsaturated double bond as a photocurable functional group. The ethylenically unsaturated double bond is not particularly limited, but examples thereof include a (meth)acrylic group, a vinyl group, and an allyl group, with a (meth)acrylic group being particularly preferred in terms of the chemical resistance of the resulting cured product.

[0037] The photocurable alkali-soluble resin (A2) can be a resin containing at least the following units (a2-1) and (a2-2). The photocurable alkali-soluble resin (A2) may contain two or more of the same structural units shown below (for example, two types of units (a2-2)).

[0038] (In unit (a2-1), R １ each independently represents a hydrogen atom or a methyl group; R ５ represents a linear, branched, or cyclic aliphatic hydrocarbon group having 2 to 15 carbon atoms, which may contain a heteroatom. １ represents a hydrogen atom or a methyl group; X １ represents a single bond or a linear or cyclic aliphatic hydrocarbon group having 1 to 15 carbon atoms which may contain an oxygen atom.

[0039] - Unit (a2-1) - The unit (a2-1) is a unit corresponding to an unsaturated compound having a (meth)acryloyl group. １ are each independently a hydrogen atom or a methyl group, and a methyl group is preferred from the viewpoint of water resistance. ５ represents a linear, branched, or cyclic aliphatic hydrocarbon group having 2 to 15 carbon atoms, which may contain a heteroatom (a divalent linking group). From the viewpoint of the reactivity of the composition, the carbon number of the aliphatic hydrocarbon group, which may contain a heteroatom, is preferably 3 to 10. These aliphatic hydrocarbon groups may have an -O- structure (a structure containing an oxygen atom: for example, -OH (hydroxyl group), an ether group (-O-), an ester group (-CO-O-), or an acid anhydride group (-CO-O-CO-)), a structure containing a sulfur atom such as an -S- structure, or a structure containing a nitrogen atom such as an -NH- structure. Examples of linear or branched aliphatic hydrocarbon groups include alkylene groups having 2 to 15 carbon atoms, and aliphatic hydrocarbon groups having 2 to 15 carbon atoms which may contain multiple ester groups or acid anhydride groups (-CO-O-CO-). Examples of the cyclic aliphatic hydrocarbon group include a cycloalkylene group having 3 to 15 carbon atoms, and a cycloalkylene group having 3 to 15 carbon atoms which may contain a plurality of ester groups or acid anhydride groups. ５may be an aliphatic hydrocarbon group containing both linear and cyclic moieties. ５ Examples of the group include -CH ２ -CH(OH)-CH ２ -, -CH ２ -CH ２ -O-CO-NH-CH ２ -CH ２ -O-, -CO-O-CH ２ -CH(OH)-CH ２ -O-, -CO-O-CH ２ -CH ２ -O-CO-NH-CH ２ -CH ２ -O-, -CO-O-CH ２ -CH ２ -CH ２ -CH ２ -O-CO-NH-CH ２ -CH ２ -O- and the like.

[0040] Preferred structures of the unit (a2-1) include units corresponding to the following compounds:

[0041]

[0042] - Unit (a2-2) - The unit (a2-2) is a unit corresponding to an unsaturated carboxylic acid and has the same structure as the unit (a1-1) described above. １ 、 X １ has the same meaning as in the unit (a1-1), and preferred examples are also the same.

[0043] - Unit (a2-3) - In terms of resistance to a developing solution, the photocurable alkali-soluble resin (A2) may be a resin containing the following unit (a2-3) in addition to the above units (a2-1) and (a2-2).

[0044] (In the formula, R １ represents a hydrogen atom or a methyl group; R ４represents at least one selected from a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 20 carbon atoms, which may contain an oxygen atom, an aromatic group, and a combination thereof.

[0045] The unit (a2-3) is a unit corresponding to an unsaturated compound and has the same structure as the unit (a1-3) described above. １ 、 R ４ has the same meaning as in the unit (a1-3), and preferred examples are also the same.

[0046] —Constituent Ratio— From the viewpoint of achieving both resistance to a developer and developability, the contents (mol %) of the units (a2-1), (a2-2), and (a2-3) in the alkali-soluble resin (A2) are preferably (a2-1) / (a2-2) / (a2-3)=10 to 70 / 1 to 50 / 0 to 70, more preferably 15 to 60 / 5 to 40 / 0 to 60, and particularly preferably 20 to 50 / 10 to 30 / 0 to 50.

[0047] -Other Structural Units- The alkali-soluble resin (A2) may contain other structural units that do not fall into any of the above-mentioned units (a2-1) to (a2-3). Examples of other structural units include benzyl methacrylate, 2-methacryloyloxyethyl isocyanate, 2-hydroxyethyl methacrylate, and N-cyclohexyl succinimide. From the viewpoint of achieving both resistance to a developer and developability, the content (mol %) of the other structural units in the alkali-soluble resin (A2) is preferably 0 to 30, and more preferably 0 to 15.

[0048] (Specific Examples) Specific examples of the alkali-soluble resin (A2) include the following polymers.

[0049]

[0050] (Acid Value) From the viewpoint of achieving both resistance to a developer and developability, the acid value of the alkali-soluble resin (A2) is preferably from 20 to 100 mgKOH / g, more preferably from 25 to 90 mgKOH / g, even more preferably from 30 to 80 mgKOH / g, and particularly preferably from 30 to 70 mgKOH / g. As the acid value of the alkali-soluble resin, a theoretical acid value can be used.

[0051] (Molecular Weight) From the viewpoint of developability, the weight average molecular weight of the alkali-soluble resin (A) can be 30,000 or less, preferably 3,000 to 30,000, more preferably 4,000 to 25,000, and particularly preferably 5,500 to 13,000. The molecular weight of the alkali-soluble resin (A) can be measured by gel permeation chromatography (manufactured by Tosoh Corporation, product number: HLC-8120, column: two columns connected together, G-5000HXL and G-3000HXL, detector: RI, mobile phase: tetrahydrofuran).

[0052] (Glass Transition Temperature) From the viewpoints of heat resistance, developability, and low-temperature curing property, the glass transition temperature of the alkali-soluble resin (A) is preferably 0 to 300° C., more preferably 30 to 250° C., and particularly preferably 50 to 200° C. The glass transition temperature can be measured by a differential scanning calorimeter (DSC).

[0053] (Epoxy Equivalent) From the viewpoint of achieving both resistance to a developer and developability, the epoxy equivalent of the alkali-soluble resin (A) is preferably from 200 to 1,000, more preferably from 250 to 800, and particularly preferably from 300 to 600. The epoxy equivalent can be determined, for example, according to JIS K7236 (2001).

[0054] (Double Bond Equivalent) From the viewpoint of reactivity, the double bond equivalent of the alkali-soluble resin (A) is preferably 150 to 2,000, more preferably 150 to 1,500, and particularly preferably 200 to 1,000. The double bond equivalent can be calculated, for example, by "(mass of polymer per mol) / (number of ethylenically unsaturated groups per mol)".

[0055] (Content) The content of the alkali-soluble resin (A) in the curable resin composition of the present embodiment is not particularly limited, but from the viewpoint of developability, for example, the content is preferably 30 to 80 mass %, more preferably 40 to 70 mass %, and particularly preferably 45 to 65 mass %, relative to the total solid content in the curable resin composition.

[0056] <Other Polymers> The curable resin composition of the present embodiment may contain other polymers in addition to the alkali-soluble resin (A) as long as the effects of the present invention are not impaired.

[0057] <Polyfunctional (meth)acrylic monomer (B)> The curable resin composition of the present embodiment contains a (meth)acrylic monomer (B) having two or more polymerizable functional groups (hereinafter also simply referred to as (meth)acrylic monomer (B)). The polyfunctional (meth)acrylic monomer (B) in the present embodiment preferably contains at least one of a (meth)acrylic monomer (B1) represented by the following formula (b-1) and a (meth)acrylic monomer (B2) represented by the following formula (b-2), which will be described later. Note that, from the viewpoint of achieving a desired surface resistivity, the polyfunctional (meth)acrylic monomer (B) preferably has three or more polymerizable functional groups, more preferably 3 to 30, and even more preferably 3 to 25.

[0058] ((Meth)acrylic Monomer (B1)) The (meth)acrylic monomer (B1) is a compound having two polymerizable functional groups and a ring structure contained between the two polymerizable functional groups, and has at least one (meth)acrylic group. By using the (meth)acrylic monomer (B1), the curable resin composition of the present embodiment can easily form a fine pattern.

[0059] Here, the term "ring structure" refers to a structure having at least one cyclic skeleton, and includes both a structure consisting of only a cyclic skeleton and a structure consisting of a cyclic skeleton and a linear structure bonded to the cyclic skeleton. Furthermore, the term "ring structure contained between two polymerizable functional groups" means that two polymerizable functional groups are bonded via a cyclic structure, and the polymerizable functional groups may be bonded directly or indirectly to the cyclic skeleton. From the viewpoint of resistance to a developer, the cyclic structure of the (meth)acrylic monomer (B1) may be any one selected from the group including an aliphatic hydrocarbon group having 6 to 26 carbon atoms and optionally containing an oxygen atom, an aromatic hydrocarbon group having 6 to 26 carbon atoms and optionally containing an oxygen atom, and combinations thereof (e.g., combinations of an aliphatic hydrocarbon and an aromatic hydrocarbon, combinations of different aliphatic hydrocarbons, different aromatic hydrocarbon compounds, etc.). Specific examples of the cyclic skeleton include a fluorene skeleton, a cyclohexane skeleton, a bisphenol A skeleton, a dicyclopentane skeleton, and combinations thereof.

[0060] The "polymerizable functional group" refers to a (meth)acrylic group itself, a group containing one (meth)acrylic group, or a functional group containing one polymerizable group other than a (meth)acrylic group. Examples of polymerizable functional groups other than a (meth)acrylic group include a vinyl group, an allyl group, an epoxy group, and a (meth)acrylamide group. Hereinafter, the term "group containing a (meth)acrylic group" refers to a (meth)acrylic group itself or a group containing one (meth)acrylic group. The number of polymerizable functional groups in the (meth)acrylic monomer (B1) is two. The two polymerizable functional groups may be the same or different from each other.

[0061] The (meth)acrylic monomer (B1) is represented by the following formula (b-1):

[0062] (In the formula, R １２ and R １３ each independently represents a hydrogen atom or a methyl group; Y １ and Y ２ each independently represents a single bond or a linear or branched aliphatic hydrocarbon group having 1 to 26 carbon atoms which may contain an oxygen atom; X１１ represents an aliphatic hydrocarbon group or aromatic group having a cyclic skeleton and having 6 to 26 carbon atoms; W １ and W ２ each independently represents O, N, or S.

[0063] In formula (b-1), R １２ and R １３ Y each independently represents a hydrogen atom or a methyl group, and is preferably a hydrogen atom from the viewpoint that the composition exhibits good curability upon exposure (hereinafter simply referred to as "curability"). １ and Y ２ each independently represents a single bond or a linear or branched aliphatic hydrocarbon group (divalent bonding group) having 1 to 26 carbon atoms, which may contain an oxygen atom. From the viewpoint of curability, the number of carbon atoms in the aliphatic hydrocarbon group is preferably 1 to 20, and more preferably 1 to 12. Examples of linear or branched aliphatic hydrocarbon groups include alkylene groups having 1 to 26 carbon atoms, such as methylene, ethylene, 1-methylethylene, 1-methylpropylene, 2-methylpropylene, and 1,1-dimethylethylene. In addition, Y containing an oxygen atom １ and Y ２ Examples of the group include —O(C ２ H ４ O ）ｍ - (m is 1 to 13). １ and Y ２ As the aryl group, for example, a methylene group is preferable.

[0064] X １１ represents an aliphatic hydrocarbon group or aromatic group (divalent bonding group) having a cyclic skeleton and having 6 to 26 carbon atoms. １１ The number of carbon atoms in is preferably 6 to 26. Examples of the aliphatic hydrocarbon having a cyclic skeleton and a carbon number of 6 to 26 include divalent linking groups consisting of a cyclohexane ring, a cyclodecane ring, a tricyclodecane ring, an adamantane ring, a norbornane ring, or a decalin ring, and examples of the aromatic group include divalent linking groups consisting of a benzene ring or a naphthalene ring. １１As the linking group, a divalent linking group containing at least one selected from the above-mentioned fluorene skeleton, cyclohexane skeleton, bisphenol A skeleton, dicyclopentane skeleton, and combinations thereof is preferred.

[0065] The (meth)acrylic monomer (B1) is not particularly limited, but examples thereof include the following compounds: In the following formula, l, m, and n each represent a number in the range of 1 to 13.

[0066]

[0067] ((Meth)acrylic Monomer (B2)) The (meth)acrylic monomer (B2) is represented by the following formula (b-2). (In formula (b-2), R ６ ~R １１ represents a hydrogen atom, a methacryloyl group, an acryloyl group, or an organic group. ６ ~R １１ At least three of the R groups are methacryloyl groups or acryloyl groups, and n is 0 to 10. ６ ~R １１ The organic group is preferably an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group include, but are not limited to, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an i-butyl group, a t-butyl group, an n-pentyl group, and an n-hexyl group.

[0068] In the compound (B2), in general formula (b-2), n is preferably at least 1. When n is at least 1 in general formula (b-2), flexibility is imparted to the main chain skeleton, and the contact probability between molecules is increased, improving radical polymerizability, and there is a tendency that a fine pattern can be formed even with a small exposure dose.

[0069] In the above general formula (b-2), the compound in which n is 0 is not particularly limited, but examples thereof include pentaerythritol mono(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, methoxylated pentaerythritol mono(meth)acrylate, methoxylated pentaerythritol di(meth)acrylate, methoxylated pentaerythritol tri(meth)acrylate, methoxylated pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol mono(meth)acrylate, ethoxylated pentaerythritol di(meth)acrylate acrylate, ethoxylated pentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, propoxylated pentaerythritol mono(meth)acrylate, propoxylated pentaerythritol di(meth)acrylate, propoxylated pentaerythritol tri(meth)acrylate, propoxylated pentaerythritol tetra(meth)acrylate, butoxylated pentaerythritol mono(meth)acrylate, butoxylated pentaerythritol di(meth)acrylate, butoxylated pentaerythritol tri(meth)acrylate, and butoxylated pentaerythritol tetra(meth)acrylate.

[0070] In the above general formula (b-2), the compound in which n is 1 is not particularly limited, but examples thereof include dipentaerythritol mono(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0071] In the above general formula (b-2), the compound in which n is 2 or more is not particularly limited, but examples thereof include tripentaerythritol mono(meth)acrylate, tripentaerythritol di(meth)acrylate, tripentaerythritol tri(meth)acrylate, tripentaerythritol tetra(meth)acrylate, tripentaerythritol penta(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, and tetrapentaerythritol mono(meth)acrylate. tetrapentaerythritol di(meth)acrylate, tetrapentaerythritol tri(meth)acrylate, tetrapentaerythritol tetra(meth)acrylate, tetrapentaerythritol penta(meth)acrylate, tetrapentaerythritol hexa(meth)acrylate, tetrapentaerythritol hepta(meth)acrylate, tetrapentaerythritol octa(meth)acrylate, tetrapentaerythritol nona(meth)acrylate, tetrapentaerythritol deca(meth)acrylate, polypentaerythritol (meth)acrylate, etc. These may be used alone or in combination of two or more.

[0072] (Combination of (meth)acrylic monomer (B1) and (meth)acrylic monomer (B2)) When the curable resin composition of the present embodiment contains both the (meth)acrylic monomer (B1) and the (meth)acrylic monomer (B2), the mass ratio between them is not particularly limited, but for example, the mass ratio (B1):(B2) is preferably 100:10 to 150, more preferably 100:20 to 130, and particularly preferably 100:30 to 110. From the viewpoint of reactivity, it is preferable that the amount of the (meth)acrylic monomer (B2) is greater than the amount of the (meth)acrylic monomer (B1), and from the viewpoint of developability, it is preferable that the amount of the (meth)acrylic monomer (B1) is greater than the amount of the (meth)acrylic monomer (B2).

[0073] <Other Monomers> The curable resin composition of the present embodiment may contain a polymerizable monomer other than the (meth)acrylic monomer (B) as long as the effects of the present invention are not impaired. Examples of other polymerizable monomers include, but are not limited to, compounds having three or more ethylenically unsaturated groups in the molecule. Examples of such compounds include trimethylolpropane triacrylate, pentaerythritol triacrylate, and dipentaerythritol hexaacrylate.

[0074] (Double Bond Equivalent) From the viewpoints of reactivity and developability, the double bond equivalent of the (meth)acrylic monomer (B) is preferably 70 to 1,000, more preferably 70 to 800, and particularly preferably 70 to 600. The double bond equivalent can be calculated according to the formula: molecular weight of the (meth)acrylic monomer (B) / (number of ethylenically unsaturated groups in the (meth)acrylic monomer (B)).

[0075] (Content) From the viewpoint of developability, the content of the polyfunctional (meth)acrylic monomer (B) in the curable resin composition of the present embodiment is such that the mass ratio [A:B] of the total amount [A] of the alkali-soluble resin (A) to the total amount [B] of the (meth)acrylic monomer (B) is preferably 100:40 to 80, more preferably 100:50 to 80, still more preferably 100:55 to 80, and particularly preferably 100:60 to 80.

[0076] Furthermore, with regard to the content of the (meth)acrylic monomer (B) in the curable resin composition of the present embodiment, from the viewpoint of developability, the mass ratio [T:B] of the total amount (T) of the solid content in the curable composition to the total amount [B] of the polyfunctional (meth)acrylic monomer (B) is preferably 100:20 to 60, more preferably 100:20 to 50, and even more preferably 100:30 to 40.

[0077] <Ionic Liquid (C)> The ionic liquid (C) is an organic salt that does not contain a molecular solvent and is composed only of ions, and has a melting point of 150°C or less, and is composed of a cationic component and an anionic component. The organic salt refers to a salt that contains at least one of ions derived from an organic acid and ions derived from an organic base. In this embodiment, from the viewpoint of achieving a desired surface resistivity, the melting point of the ionic liquid (C) is preferably 100°C or less, more preferably 50°C or less, and even more preferably 40°C or less.

[0078] The cations constituting the ionic liquid (C) of this embodiment preferably include at least one of a quaternary ammonium cation and a quaternary phosphonium cation.

[0079] The quaternary ammonium cation is not particularly limited, but examples thereof include non-heterocyclic quaternary ammonium cations and heterocyclic quaternary ammonium cations.

[0080] The non-heterocyclic quaternary ammonium cation in this embodiment is represented by the following general formula (c-1): (In formula (c-1), R ２１ , R ２２ , R ２３ , and R ２４ R is a linear or branched alkyl group having 1 to 30 carbon atoms which may have a polymerizable functional group at the end. ２１ , R ２２ , R ２３ , and R ２４ may be the same or different from each other.)

[0081] R ２１ , R ２２ , R ２３ , and R ２４ The number of carbon atoms in each of the groups is preferably 1 to 20 from the viewpoint of realizing a desired surface resistivity.

[0082] The quaternary phosphonium cation in this embodiment is represented by the following general formula (c-2): (In formula (c-2), R ２５ , R ２６ , R２７ , and R ２８ R is a linear or branched alkyl group having 1 to 30 carbon atoms which may have a polymerizable functional group at the end. ２５ , R ２６ , R ２７ , and R ２８ may be the same or different from each other.)

[0083] R ２５ , R ２６ , R ２７ , and R ２８ The number of carbon atoms in each of the groups is preferably 1 to 20 from the viewpoint of realizing a desired surface resistivity.

[0084] The anion constituting the ionic liquid (C) is not particularly limited, but examples thereof include borate anion, phosphate anion, sulfate anion, imide anion, chloride ion, and bromide ion.

[0085] (Polymerizable Functional Group) In addition, from the viewpoint of realizing a desired surface resistivity, the ionic liquid (C) in this embodiment preferably has a polymerizable functional group. The ionic liquid (C) having a polymerizable functional group means that at least one of the cation component and the anion component constituting the ionic liquid (C) has a polymerizable functional group. The definition of the polymerizable functional group is the same as above. Note that, when each compound represented by each formula above has a polymerizable functional group, R 2１ ~R 2４ , R 25 ~R 28 At least one of the substituents represented by the formula (I) is substituted with a group having a polymerizable functional group. The group having a polymerizable functional group may be the polymerizable functional group itself, or may be a group containing the polymerizable functional group and another structure (such as an alkyl group).

[0086] (Content) From the viewpoint of achieving developability and a desired surface resistivity, the content of the ionic liquid (C) in the curable resin composition of the present embodiment is such that the mass ratio [A:C] of the total amount [A] of the alkali-soluble resin to the total amount [C] of the ionic liquid (C) is preferably 100:1 to 20, more preferably 100:1 to 15, and even more preferably 100:1 to 10.

[0087] With regard to the content of the ionic liquid (C) in the curable resin composition of the present embodiment, from the viewpoints of developing property and realizing a desired surface resistivity, the mass ratio [T:C] of the total amount [T] of the solid content in the curable composition to the total amount [C] of the ionic liquid (C) is preferably 100:0.1 to 20, more preferably 100:0.5 to 15, and even more preferably 100:1.0 to 10.

[0088] <Photopolymerization initiator> The curable resin composition of this embodiment may be a negative curable resin composition containing a photopolymerization initiator. The photopolymerization initiator is a compound that is activated by various actinic rays, such as ultraviolet light, and initiates polymerization. Examples of the photopolymerization initiator include a radical photopolymerization initiator, a cationic photopolymerization initiator, and an anionic photopolymerization initiator. The photopolymerization initiator is not particularly limited, but for example, a photopolymerization initiator that generates radicals that polymerize ethylenically unsaturated groups when exposed to ultraviolet or visible light can be suitably used.

[0089] The photopolymerization initiator is not particularly limited, but examples thereof include acetophenones such as acetophenone, 2,2'-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, and p-tert-butylacetophenone; 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one; 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinophenyl)-butan-1-one; Examples of photopolymerization initiators include α-aminoketone-based photopolymerization initiators such as 1-[4-(phenylthio)phenyl]octane-1,2-dione 2-(O-benzoyloxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), 1-[9-ethyl-6-benzoyl-9H-carbazol-3-yl]-octan-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethan-1-one oxime-O-benzoate, 1-[9-n-butyl-6-(2-ethylbenzoyl)-9H-carbazol-3-yl]-

[0023] Ethanone-1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzoyl)-9.H.-carbazol-3-yl]-1-(O-acetyloxime), Ethanone-1-[9-ethyl-6-(2-methyl-4-tetrahydropyranylbenzoyl)-9.H.-carbazol-3-yl]-1-(O-acetyloxime), Ethanone-1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9.H.-carbazol-3-yl]-1-(O-acetyloxime), Ethanone-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolanyl)methoxybenzoyl}-9.H. -carbazol-3-yl]-1-(O-acetyloxime), and other oxime ester photopolymerization initiators; and benzophenones such as benzophenone, 2-chlorobenzophenone, and p,p'-bisdimethylaminobenzophenone;Benzoin ethers such as benzil, benzoin, benzoin methyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; sulfur compounds such as benzil dimethyl ketal, thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2-methylthioxanthone, and 2-isopropylthioxanthone; anthraquinones such as 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, and 2,3-diphenylanthraquinone; Examples of suitable photopolymerization initiators include triazines such as 2,4-trichloromethyl-(4'-methoxynaphthyl)-6-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine, and 2,4-trichloromethyl-(4'-methoxystyryl)-6-triazine; organic peroxides such as azobisisobutyronitrile, benzoyl peroxide, and cumene peroxide; and thiol compounds such as 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, and 2-mercaptobenzothiazole. From the viewpoint of reactivity, oxime ester photopolymerization initiators are preferred. These photopolymerization initiators may be used alone or in combination of two or more.

[0090] The content of the photopolymerization initiator in the curable resin composition of the present embodiment is not particularly limited. For example, from the viewpoint of photoreactivity and storage stability, the content is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and particularly preferably 5 to 20 parts by mass, relative to 100 parts by mass of the polyfunctional (meth)acrylic monomer (B).

[0091] <Method for Producing Curable Resin Composition> The curable resin composition of the present embodiment contains the alkali-soluble resin (A), the (meth)acrylic monomer (B), and the ionic liquid (C), and can be prepared by adding a solvent, a polymerization inhibitor, a photopolymerization initiator, and the like, and stirring and mixing them.

[0092] <Solvent> In the present embodiment, a known solvent can be appropriately selected and used depending on the desired purpose. The solvent is not particularly limited, and examples thereof include cyclohexanone (anone), cyclopentanone, diethylene glycol ethyl methyl ether, acetylacetone, methanol, ethanol, ethyl cellosolve, ethyl cellosolve acetate, methyl cellosolve, methyl cellosolve acetate, diglyme, cyclohexanone, ethylbenzene, xylene, isoamyl acetate, n-amyl acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (PGMAC), propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ... Examples of the alkyl ether include ethylene glycol ethyl methyl ether (EDM), diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether, triethylene glycol monoethyl ether acetate, liquid polyethylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monoethyl ether acetate, lactate ester, methyl methoxypropionate, and ethyl ethoxypropionate.

[0093] The solvent may be used alone or in combination of two or more. The content of the solvent in the curable resin composition of this embodiment is not particularly limited. However, from the viewpoint of storage stability and coatability, for example, it is preferable to use a solvent so that the total solids concentration (total mass of components other than the solvent in the composition) is preferably 1 to 80% by mass, more preferably 5 to 70% by mass, even more preferably 10 to 60% by mass, and particularly preferably 15 to 30% by mass. By setting the solids content within the above range, the viscosity of the curable resin composition can be made appropriate, and coatability when applied to a substrate or the like to form a film is particularly improved.

[0094] <Polymerization inhibitor> The curable resin composition of the present embodiment may contain a polymerization inhibitor from the viewpoint of suppressing polymerization of the (meth)acrylic monomer (B) etc. under unintended circumstances, conditions, etc. Furthermore, a known ultraviolet absorber may be used as the polymerization inhibitor.

[0095] The polymerization inhibitor is not particularly limited, but examples thereof include 4-methoxyphenol, 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-N,N-dimethylamino-p-cresol, 2,4-dimethyl-6-tert-butylphenol, 4-tert-butylcatechol, 4,4'-thio-bis(3-methyl-6-ter phenolic compounds such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-acetamino-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and 4-oxo-2,2,6,6-tetramethylpiperidine; quinone compounds such as methoquinone (MEHQ), hydroquinone, 2,5-di-tert-butylhydroquinone, 2,6-di-tert-butylhydroquinone, and benzoquinone; cuprous chloride; copper dialkyldithiocarbamates such as copper dimethyldithiocarbamate; amino compounds such as phenothiazine, N,N'-diphenyl-p-phenylenediamine, phenyl-β-naphthylamine, N,N'-di-β-naphthyl-p-phenylenediamine, and N-phenyl-N'-isopropyl-p-phenylenediamine; and hydroxyamine compounds such as 1,4-dihydroxy-2,2,6,6-tetramethylpiperidine, 1-hydroxy-2,2,6,6-tetramethylpiperidine, and 4-hydroxy-2,2,6,6-tetramethylpiperidine. As the polymerization inhibitor, for example, methoquinone can be suitably used. These polymerization inhibitors may be used alone or in combination of two or more kinds.

[0096] The amount of the polymerization inhibitor in the curable resin composition of the present embodiment is not particularly limited, but may be 0.1 to 0.6 mass % relative to the total solid content (the total mass of components in the composition other than the solvent) from the viewpoint of processability of patterns such as through holes and grooves.

[0097] The curable resin composition of the present embodiment may also contain various additives, such as inorganic fine particles, adhesion promoters, surfactants, storage stabilizers, leveling agents, light stabilizers, antioxidants, etc. Examples of these additives include those described in JP-A-2012-215833.

[0098] <<Insulating Cured Film>> The use of the curable resin composition of the present embodiment is not particularly limited, and it can be used for forming an insulating film, for example, as an insulating cured film, particularly an insulating cured film for a display device. The insulating cured film for a display device can be formed by forming a coating film from the curable resin composition on a substrate such as a glass substrate, ITO, a metal film, or an organic film using various application methods such as rotary coating such as spin coating, casting coating such as die coating, coating by roll coating, or coating by a roll transfer method, and then curing the coating film.

[0099] Specifically, the cured film of the present embodiment can be formed by applying the curable resin composition to a substrate such as a glass substrate and curing it by irradiating it with light. The cured film of the present embodiment can also be patterned by irradiating it with light through a mask, developing it, and then heat-treating it as needed.

[0100] The insulating cured film can be used for any application such as an insulating film, a protective film, or a flat film. The insulating cured film using the curable resin composition of the present embodiment can be particularly suitably used as an insulating film for a display device. Examples of insulating films used in such display devices include insulating films for liquid crystal panels that constitute liquid crystal displays or touch panel displays, and insulating films for touch panels that constitute touch panel displays.

[0101] Furthermore, the insulating cured film of the present embodiment may be used not only as a so-called permanent film that is maintained in an apparatus such as a display device, but also as a resist film that is used when patterning an ITO film on a glass substrate.

[0102] (Pattern) For example, an insulating cured film of a liquid crystal panel can be provided with a pattern such as through-holes or grooves of a desired size for purposes such as electrical conduction between electrodes. The curable resin composition of the present embodiment has excellent pattern processability, and can form a pattern in which the through-holes or grooves are fully opened to their bottoms and the cross-sectional shape of the through-holes or grooves is an inverted trapezoid when viewed from the direction of exposure. Therefore, the composition can be suitably used as a cured film-forming composition in which a pattern such as through-holes or grooves is formed (hereinafter also referred to as a "patterned cured film-forming composition").

[0103] The method for producing a patterned cured film (hereinafter also referred to as a "patterned cured film") using the curable resin composition of this embodiment is not particularly limited, and known pattern formation methods using lithography techniques and cured film production methods can be appropriately selected. An example of a method for producing a patterned cured film using the curable resin composition of this embodiment includes a step of applying the curable resin composition of this embodiment to a substrate to form a coating film (coating film formation step), a step of exposing the coating film to light through a mask for forming a pattern such as through holes or grooves (exposure step), a step of removing the non-exposed portions of the coating film after exposure with a developer (development step), and a step of heating the coating film from which the non-exposed portions have been removed (e.g., 90 to 230°C, 10 to 60 minutes) (post-baking step). Between the coating film formation step and the exposure step, a step of heating the coating film (e.g., 80 to 100°C, 60 to 180 seconds) (pre-baking step) may be performed.

[0104] The curable resin composition of this embodiment has high developer resistance in the exposed area (cured area). Therefore, it is possible to form a desired fine pattern while suppressing overdevelopment. Furthermore, the taper angle of the cross-sectional shape of the hole or groove can be maintained without the wall surface of the pattern sagging during the post-bake process. Thus, by using the curable resin composition of this embodiment, it is possible to form a pattern that is fully open all the way to the bottom, even for a pattern with a small hole diameter (e.g., a hole diameter of 15 μm or less).

[0105] The thickness of the patterned cured film can be set appropriately depending on the purpose, but for example, from the viewpoints of migration resistance and developability, it can be 0.2 μm to 20 μm, and furthermore, it can be 0.5 μm to 10 μm. Furthermore, the diameter of the through-holes formed in the patterned cured film can be set appropriately depending on the purpose, but for example, from the viewpoints of reactivity and developability, it can be 1 μm to 200 μm, and furthermore, it can be 5 μm to 100 μm, and furthermore, it can be 10 μm to 50 μm. Note that the "hole diameter" of the through-holes formed in the patterned cured film is the diameter of the hole at a height corresponding to 10% of the height from the bottom of the through-hole, as shown in FIG. 3 (10% Bottom CD in FIG. 3; "R １０ ")

[0106] <Liquid Crystal Panel> A liquid crystal panel includes a liquid crystal layer oriented in a predetermined direction, a pair of transparent substrates sandwiching the liquid crystal layer, and a pair of polarizing plates sandwiching the substrates to form a polarizer and an analyzer. Furthermore, an electrode layer patterned into a predetermined shape, an insulating film, and an alignment layer may be formed in this order on the surface of the substrate on which the liquid crystal layer is provided. The liquid crystal panel of this embodiment is not particularly limited, but for example, the cured film of this embodiment may be provided between the electrode layer and the alignment layer.

[0107] As described above, the curable resin composition of the present embodiment and the insulating cured film using the same can be suitably used as an insulating film for a touch panel. Hereinafter, the insulating cured film of the present embodiment and the insulating film for a touch panel may be collectively referred to simply as the “cured film of the present embodiment.”

[0108] The touch panel of this embodiment may be a resistive touch panel, a capacitive touch panel, an ultrasonic touch panel, or an optical touch panel, but is preferably a capacitive touch panel. A capacitive touch panel uses, for example, glass with an ITO film as a substrate, and an insulating film or a protective film is provided in the laminated structure (for example, between electrodes) to prevent erroneous recognition of the touch position. When the touch panel of this embodiment is a capacitive touch panel, the cured film of this embodiment can be used, for example, as an insulating film, a protective film, or both in the laminated structure.

[0109] Touch panels can be divided into a two-sided structure in which an X electrode is arranged on one side of an insulating film and a Y electrode on the other side, and a single-sided structure in which the X electrode and the Y electrode are formed on the same plane. The touch panel of this embodiment may have either a two-sided or single-sided structure, but a single-sided structure is particularly preferable. In a single-sided touch panel structure, the X electrode and the Y electrode are electrically separated. In this case, the electrode pattern can be classified into, for example, an island pattern, a through-hole pattern, etc. For example, in the case of an island pattern or a single-sided touch panel structure, the separated electrodes are electrically connected by a member called a jumper portion. Furthermore, a transparent electrode such as an ITO film is used for the electrode jumper portion. For example, when the jumper portion connects the separated Y electrodes, an insulating layer is provided below the jumper portion to maintain insulation from the X electrode. Furthermore, an insulating film (protective film) is usually formed uniformly on each electrode arranged in a single-sided configuration. Therefore, when the touch panel of this embodiment has a single-sided touch panel structure, the touch panel of this embodiment can use, for example, the cured film of this embodiment as an insulating film formed on the electrode, an insulating layer formed under the jumper portion, or both.

[0110] Furthermore, when a touch panel is incorporated into a liquid crystal display device, it can be classified into an out-cell structure, an on-cell structure, and an in-cell structure depending on the location where it is installed. In the on-cell structure and the in-cell structure, the touch panel is incorporated within the liquid crystal panel, while in the out-cell structure, the touch panel is incorporated outside the liquid crystal panel. In the on-cell structure, the touch panel is installed between the polarizing plate on the observation side and a liquid crystal laminate (a laminate composed of a pair of glass substrates and a liquid crystal layer interposed therebetween). In the in-cell structure, the liquid crystal layer of the liquid crystal laminate has the touch panel function. The touch panel of this embodiment can be applied to any of these structures, but is preferably used in, for example, an on-cell structure.

[0111] Hereinafter, one aspect of the touch panel of this embodiment will be described with reference to the drawings. Fig. 1 is a plan view showing the configuration of one aspect of the touch panel of this embodiment. When the touch panel of this embodiment is a single-sided touch panel as shown in Fig. 1, ITO (indium tin oxide) electrodes (X1 to X3, Y1 to Y3) are formed on a glass substrate 10.

[0112] The material of the glass substrate 10 is not particularly limited, but examples thereof include glass plates such as soda-lime glass, low-alkali borosilicate glass, and non-alkali aluminoborosilicate glass. Alternatively, a plastic plate or film made of polyethylene terephthalate (PET), triacetyl cellulose (TAC), polymethyl methacrylate (PMMA), polycarbonate (PC), or the like may be used instead of the glass substrate.

[0113] The ITO electrodes (X1 to X3, Y1 to Y3) are transparent electrodes. In this embodiment, ITO is used as the material for the transparent electrodes. However, any material that can be disposed on the substrate surface can be used. In addition to ITO, inorganic conductive materials such as ZnO (zinc oxide) and organic conductive materials such as PEDOT / PSS (polyethylenedioxythiophene / polystyrene sulfonate), polyaniline, and polypyrrole can also be used. These materials may be used alone or in combination of two or more. Although not shown in FIGS. 1 and 2 , a metal thin film functioning as metal wiring may be used as an underlying layer or in place of a transparent electrode in each electrode and jumper section X12. Metal materials such as Mo (molybdenum), Al (aluminum), Ag (silver), and Pd (palladium) can be used for the metal thin film, with the use of at least one of Mo and Al being preferred.

[0114] As shown in FIG. 1 , ITO electrodes X1 to X3 are arranged in the direction indicated by the arrow P in FIG. 1 . Although ITO electrodes X1 to X3 are isolated from adjacent electrodes, they are electrically connected to adjacent electrodes in the P direction via jumper portions X12. The jumper portions X12 can be formed of a material similar to transparent electrodes, such as ITO. Furthermore, an insulating film 14, shown in FIG. 2 , is interposed between the lower portion of the jumper portion X12 in the thickness direction and the connecting portion of the ITO electrode Y. Furthermore, through holes 20 are provided at both ends of each jumper portion X12 to electrically connect adjacent electrodes in the P direction. Furthermore, ITO electrodes Y1 to Y3 are arranged in the direction indicated by the arrow Q in FIG. 1 . The ITO electrodes Y1 to Y3 are continuously connected to adjacent electrodes in the Q direction via connecting portions formed of ITO films, and are electrically connected in the Q direction. Typically, the ITO electrodes Y1 to Y3 are continuously formed integrally with their respective connecting portions during electrode molding. Hereinafter, the group of electrodes electrically connected in the P direction will be referred to as "X electrodes," and the group of electrodes electrically connected in the Q direction will be referred to as "Y electrodes." As shown in Figure 1, in a single-sided touch panel, the X electrodes are arranged along the P direction, and the Y electrodes are arranged along the Q direction.

[0115] Next, the cross-sectional structure of the touch panel of this embodiment will be described with reference to FIG. 2 . FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 . As shown in FIG. 2 , an insulating film 14 and a connection portion Y12 between the ITO electrodes Y1 and Y2 are interposed between the ITO electrodes X2 and X3. The ITO electrodes X2 and X3 are electrically connected by the jumper portion X12 as described above. Furthermore, a portion of the insulating film 14 extends below the jumper portion X12 in the thickness direction between the jumper portion X12 and the connection portion Y12, thereby maintaining insulation between the jumper portion X12 and the connection portion Y12. Furthermore, an insulating protective layer 16 is provided on the insulating film 14 and on the upper side of the jumper portion X12 in the thickness direction.

[0116] In this embodiment, the cured film of this embodiment is used for at least one of the insulating film 14 and the insulating protective layer 16. However, the other may be formed using a known material that has conventionally been used for insulating films and protective films.

[0117] In the touch panel described above, the method for forming the cured film of this embodiment is not particularly limited. For example, a coating film can be formed on an underlying layer (e.g., the glass substrate 10 and ITO electrode for the insulating film 14, or the ITO electrode for the insulating protective layer 16) by a coating method such as spray coating, spin coating, slit die coating, roll coating, or bar coating. The dry film thickness of the coating film is not particularly limited. For example, in the case of the insulating protective layer 16, the dry film thickness is preferably 0.5 to 20 μm, and more preferably 1.0 to 10 μm. Similarly, in the case of the insulating film 14, the dry film thickness is preferably 0.2 to 10 μm, and more preferably 0.5 to 5 μm. If necessary, the coating film can be exposed to light through a mask having a predetermined pattern that is provided in contact with or out of contact with the coating film. The type of light used for exposure is not particularly limited. Examples include visible light, ultraviolet light, far infrared light, electron beams, and X-rays. Of these, ultraviolet light is preferred. The illuminance of the light beam is not particularly limited, but is preferably 5 to 150 mW / cm at 365 nm. ２ is preferably 5 to 35 mW / cm ２is particularly preferred. Thereafter, if necessary, the film is immersed in an aqueous alkaline developer such as sodium carbonate, sodium hydroxide, or potassium hydroxide, or tetramethylammonium hydroxide (TMAH), or the developer is sprayed onto the film using a spray or the like to remove the uncured portions, thereby forming a desired pattern. Furthermore, in order to promote polymerization of the photosensitive composition and harden the pattern, heating (post-baking) can be performed as necessary. Note that the above-mentioned pattern formation method can be applied when forming the cured film.

[0118] Furthermore, for example, when forming the jumper portion X12, first, patterned X electrodes and Y electrodes are formed on the glass substrate 10, and then a curable resin composition is applied to the glass substrate 10 and the surface of the X electrodes, and the curable resin composition is exposed and developed using a mask capable of forming the insulating film 14 and the through-holes 20. Next, a material (e.g., ITO) that will become the jumper portion X12 is deposited on the insulating film 14 and the through-holes 20 by PVD or the like to form a conductive layer. Thereafter, a protective layer is provided only on the surface of the conductive layer at the location where the jumper portion X12 will be formed (e.g., the insulating film 14 on the connecting portion Y12 in FIG. 2 ), and an etching process is performed, whereby the jumper portion X12 can be formed on the insulating film 14 on the connecting portion Y12.

[0119] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0120] [Examples and Comparative Examples] Each component was mixed according to the formulation shown in the table below to prepare a curable resin composition. Mixing was carried out at room temperature, blocking ultraviolet light to prevent the initiation of polymerization. The values ​​for each component in the table all represent mass % of the entire composition (excluding the solvent).

[0121]

[0122]

[0123] The components used in the table above were those shown in the table below. Alkali-soluble resins A-1 to A-3 were produced by mixing raw material compounds (monomers) and polymerization initiators in the ratios (molar ratios) shown in the table in a heatable container, and mixing at 65°C for 13 hours.

[0124]

[0125] B-1: Aronix M-404 manufactured by Toagosei Co., Ltd. B-2: Viscoat #802 manufactured by Osaka Organic Chemical Industry Co., Ltd. B-3: Viscoat #300 manufactured by Osaka Organic Chemical Industry Co., Ltd. B-4: Light Acrylate DCP-A manufactured by Kyoeisha Chemical Co., Ltd. B'-1: Viscoat #155 (cyclohexyl acrylate) manufactured by Osaka Organic Chemical Industry Co., Ltd. B'-2: IBXA (isobornyl acrylate) manufactured by Osaka Organic Chemical Industry Co., Ltd. C-1: IL-MA2 manufactured by Koei Chemical Co., Ltd. C-2: IL-AP3 manufactured by Koei Chemical Co., Ltd. C-3: IL-A2 manufactured by Koei Chemical Co., Ltd. D-1: Irgacure OXE01 manufactured by BASF Japan Ltd. E-1: SZR-En10-PGMEA-M00 manufactured by Sakai Chemical Industry Co., Ltd. F-1: Hisorb EDM (Diethylene glycol methyl ethyl ether) manufactured by Toho Chemical Industry Co., Ltd. F-2: Cyclopentanone manufactured by Zeon Corporation

[0126] <Evaluation> The curable compositions of the Examples and Comparative Examples obtained above were evaluated. The results are shown in Tables 1 and 2 above.

[0127] (Transmittance Evaluation) Each curable resin composition according to each Example and Comparative Example was applied to a 10 cm x 10 cm square glass substrate using a spin coater so that the finished film thickness was 2.0 μm, and then dried under reduced pressure at room temperature using a vacuum dryer (VCD). The coating film was heated on a hot plate at 90°C for 2 minutes to completely remove the solvent. The obtained coating film was exposed to light from an ultra-high pressure mercury lamp at an exposure gap of 170 μm and 50 mJ / cm. ２ (illuminance at 365 nm: 10 mW / cm ２ ​). The substrate was then developed using a 2.38% TMAH aqueous solution for 30 seconds and post-baked at 130°C for 30 minutes to produce a substrate with a cured film. The transmittance of the substrate with the produced cured film was measured using a spectrophotometer (V-660, manufactured by JASCO Corporation). First, the transmittance of the glass substrate was measured, and the obtained UV-visible absorption spectrum was used as a reference. Next, the cured film of each Example and Comparative Example was measured using a single beam to determine the light transmittance per 2.0 μm of the cured film at a wavelength of 400 nm. The difference from the reference was defined as the light transmittance of each cured film, and the transmittance was evaluated based on the transmittance at 400 nm according to the following criteria. <Evaluation Criteria> A: The transmittance was 98% or more. B: The transmittance was 90% or more but less than 98%. C: The transmittance was less than 90%.

[0128] (Evaluation of developability) A cured film was prepared in the same manner as in the above-described transmittance evaluation method, except that light from an ultra-high pressure mercury lamp was irradiated through a photomask having a plurality of opening diameters of different sizes. The obtained cured film (through-hole pattern) was observed and evaluated according to the following criteria. <Evaluation criteria> A: Through-holes corresponding to mask opening diameters of less than 15 μm were open. B: None of the through-holes corresponding to mask opening diameters of less than 15 μm were open, but through-holes corresponding to mask opening diameters of 15 μm or more and less than 30 μm were open. C: Through-holes corresponding to mask opening diameters of 30 μm or more were open, or no through-holes corresponding to any of the mask opening diameters were open.

[0129] (Evaluation of Film Retention) Each curable resin composition according to each Example and Comparative Example was applied to a 10 cm x 10 cm square glass substrate using a spin coater so that the film thickness after drying would be 3.5 μm, and then dried under reduced pressure at room temperature using a vacuum dryer (VCD). The coating film was heated on a hot plate at 90°C for 2 minutes to completely remove the solvent, resulting in a film thickness after drying of 3.5 μm. The resulting coating film was exposed to light from an ultra-high pressure mercury lamp with an exposure gap of 170 μm and at 50 mJ / cm. ２ (illuminance at 365 nm: 10 mW / cm ２). The film was then developed for 30 seconds using a 2.38% TMAH aqueous solution and dried. The thickness of the cured film after development and drying was measured, and the residual film rate was calculated using the following formula: Residual film rate (%) = Thickness of cured film after development and drying / Thickness before development (3.5 μm) × 100 The higher the residual film rate, the better the film retention. <Evaluation criteria> A: The residual film rate is 80% or more. B: The residual film rate is 60% or more but less than 80%. C: The residual film rate is less than 60%.

[0130] (Evaluation of Surface Resistivity) The substrates having the obtained cured films were tested using a low resistance resistivity meter (Loresta UX MCP-HT800, manufactured by Nitto Seiko Analytech Co., Ltd.) and a ring probe UR-SS. The surface resistivity was calculated according to the following formula: ρs = R × RCF(s) (where ρs is the surface resistivity, R is the resistance value, and RCF(s) is the correction value (9.065)).

[0131] By comparing Example 1 with Comparative Example 1, it was found that in Example 1, in which the ionic liquid (C) was used instead of the conductive filler, the transmittance and developability were improved. By comparing each Example with Comparative Example 2, it was found that the use of the ionic liquid (C) provided excellent developability while maintaining the surface resistivity at a predetermined value. By comparing each Example with Comparative Examples 3 and 4, it was found that the use of the (meth)acrylic monomer (B) provided excellent transmittance, developability, and surface resistivity.

[0132] 10: glass substrate, X12: jumper portion, Y12: connection portion, 14: insulating film, 16: insulating protective layer, 20: through hole, X1 to X3, Y1 to Y4: ITO electrodes, X34: connection portion, K1, K5: ITO film / insulating film interface, K2: ITO film / protective film interface, K3, K4: glass substrate / ITO film interface

[0133] The disclosure of Japanese Patent Application No. 2023-203302, filed on November 30, 2023, is incorporated herein by reference in its entirety. In addition, all documents, patent applications, and technical standards mentioned in the specification are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A curable resin composition comprising: an alkali-soluble resin (A); a (meth)acrylic monomer having two or more polymerizable functional groups (B); and an ionic liquid (C).

2. The curable resin composition according to claim 1, wherein the ionic liquid (C) has a melting point of 100° C. or lower.

3. The curable resin composition according to claim 1, wherein the ionic liquid (C) has a polymerizable functional group.

4. The curable resin composition according to claim 1, wherein the cation constituting the ionic liquid (C) includes at least one of a quaternary phosphonium cation and a quaternary ammonium cation.

5. The curable resin composition according to claim 1, wherein the alkali-soluble resin (A) has an acid group and a cyclic ether group.

6. The curable resin composition according to claim 1, wherein the alkali-soluble resin (A) is a thermosetting alkali-soluble resin A1 containing at least one of the following units (a1-1) and (a1-2): (In formula (a1-1), R １ represents a hydrogen atom or a methyl group; X １ represents a single bond or a linear or cyclic aliphatic hydrocarbon group having 1 to 15 carbon atoms which may contain an oxygen atom. １ represents a hydrogen atom or a methyl group; R ３ represents a linear or branched aliphatic hydrocarbon group having 3 to 15 carbon atoms, which has a cyclic ether structure and may contain an oxygen atom.

7. The curable resin composition according to claim 6, wherein the alkali-soluble resin (A) further contains the following unit (a1-3): (In formula (a1-3), R １ represents a hydrogen atom or a methyl group; R ４ represents at least one selected from a linear, branched or cyclic aliphatic hydrocarbon group having 1 to 20 carbon atoms, which may contain an oxygen atom, an aromatic group, and a combination thereof.

8. The curable resin composition according to claim 1, wherein the alkali-soluble resin (A) has a weight average molecular weight of 30,000 or less.

9. The curable resin composition according to claim 1, wherein the (meth)acrylic monomer (B) has three or more polymerizable functional groups.

10. The curable resin composition according to claim 1, wherein the (meth)acrylic monomer (B) contains at least one of the following formulae (b-1) and (b-2): (In formula (b-1), R １２ and R １３ each independently represents a hydrogen atom or a methyl group; Y １ and Y ２ each independently represents a single bond or a linear or branched aliphatic hydrocarbon group having 1 to 26 carbon atoms which may contain an oxygen atom; X １１ represents an aliphatic hydrocarbon group or aromatic group having 6 to 26 carbon atoms and a cyclic skeleton; W １ and W ２ each independently represents O, N, or S. (In formula (b-2), R ６ ~R １１ represents a hydrogen atom, a methacryloyl group, an acryloyl group, or an organic group. ６ ~R １１ Three or more of the groups are methacryloyl groups or acryloyl groups, and n is 0 to 10.

11. The curable resin composition according to claim 1, wherein a mass ratio (A:B) of the total amount of the alkali-soluble resin (A) to the total amount of the (meth)acrylic monomer (B) is 100:40 to 80.

12. The curable resin composition according to any one of claims 1 to 11, which is used for forming an insulating film.

13. An insulating cured film obtained by curing the curable resin composition according to any one of claims 1 to 11.

14. A display device comprising the insulating cured film according to claim 13.

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