Metasurface structure, and method for manufacturing same

Abstract

This metasurface structure comprises a resin portion, a conductive portion, and a substrate, wherein the resin portion forms an uneven structure on the substrate, the surface of a convex portion of the uneven structure has a liquid-repellent property, and the conductive portion is formed by filling at least a portion of a concave portion of the uneven structure with a conductive material. It is possible to provide a metasurface structure having fine conductive material patterns.

Description

Metasurface structure and method for manufacturing the same

[0001] The present invention relates to a metasurface structure and a method for manufacturing the same.

[0002] In mobile communications, higher radio frequency waves are required to enable faster and larger capacity communications through expanded bandwidth. Next-generation technologies such as 6G are expected to provide faster and larger capacity communications than 5G, and the use of millimeter waves exceeding 100 GHz is being considered. However, millimeter waves have a high degree of directionality and are easily blocked by obstacles such as buildings and trees. Therefore, areas where the base station cannot see the signal (coverage holes) are expected to be out of communication range. Therefore, in order to utilize millimeter waves, it is necessary to increase the number of base stations and expand the communication area.

[0003] On the other hand, as a means to expand communication areas and secure communication paths, a promising approach is to install metasurface materials designed to control the reflection, transmission, refraction, absorption, and phase of electromagnetic waves and transmit the target communication radio waves to a targeted location. Metasurfaces are two-dimensional materials consisting of periodic structures smaller than the wavelength. They utilize the resonance of periodically arranged electrical circuit patterns to control the apparent permittivity and permeability of incident electromagnetic waves, thereby enabling the desired control of the intensity and directionality of the electromagnetic waves. For example, metasurface reflectors that can reflect incident electromagnetic waves in any direction other than the specular reflection direction have attracted attention (see, for example, Patent Document 1). Therefore, even when using millimeter waves, metasurfaces can be used to reflect radio waves in a desired direction and absorb electromagnetic waves that cause interference, thereby expanding communication areas.

[0004] JP 2015-46821 A

[0005] As mentioned above, metasurfaces are composed of periodic structures smaller than the wavelength, requiring fine patterning of conductive materials. While methods for patterning conductive materials include vapor deposition and nanoimprinting, inkjet printing, which can deposit the required amount of costly conductive material only at the desired location, is a highly productive method. However, as communication frequencies generally increase, the wavelength of electromagnetic waves becomes shorter, necessitating the corresponding smaller electrical circuit patterns of metasurfaces. Therefore, conventional inkjet printing makes it difficult to form the finer patterns required for metasurfaces designed for next-generation high-speed communications. Therefore, the objective of the present invention is to provide a metasurface structure with a fine and highly precise conductive material pattern.

[0006] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by the following configuration. The present invention has the following aspects.

[0007] [1] A metasurface structure comprising a resin portion, a conductive portion, and a substrate, wherein the resin portion forms a concave-convex structure on the substrate, the convex surface of the concave-convex structure being liquid-repellent, and the conductive portion is formed by filling at least a portion of the concave portions of the concave-convex structure with a conductive material. [2] The metasurface structure according to [1] above, wherein a single or multiple shapes made of the conductive portion are periodically and repeatedly arranged. [3] The metasurface structure according to [1] or [2] above, wherein at least a portion of the bottom surface of the concave portion is the substrate surface and the side surface is made of the resin portion. [4] The metasurface structure according to any of [1] to [3] above, wherein the contact angle of the wall surface of the convex portion is smaller than the contact angle of the upper surface of the convex portion. [5] The metasurface structure according to any one of [1] to [4] above, wherein 0.7 μL of diethylene glycol monobutyl ether is dropped onto the upper surfaces of the convex portions at 23° C. and 50% relative humidity using a contact angle measurement device Drop Master 500 manufactured by Kyowa Interface Science Co., Ltd., and the contact angle measured after 1 second is 20° or more. [6] The metasurface structure according to any one of [1] to [5] above, wherein 0.7 μL of diethylene glycol monobutyl ether is dropped onto the wall surfaces of the convex portions at 23° C. and 50% relative humidity using a contact angle measurement device Drop Master 500 manufactured by Kyowa Interface Science Co., Ltd., and the contact angle measured after 1 second is less than 20°. [7] The metasurface structure according to any one of [1] to [6] above, wherein the height of the convex portions of the concave-convex structure is 10 nm or more and 100 μm or less. [8] The metasurface structure according to any one of [1] to [7] above, wherein the height of the conductive portion is 5 nm or more and 10 μm or less. [9] The metasurface structure according to any one of [1] to [8] above, wherein the ratio of the height of the conductive portion to the height of the convex portion (height of the conductive portion / height of the convex portion) is 0.01 or more and 1 or less.

[10] The metasurface structure according to any one of [1] to [9] above, wherein the line width of the conductive portion is 1 μm or more and 1 mm or less.

[11] The metasurface structure according to any one of [1] to

[10] above, wherein the conductivity of the conductive portion is 100 S / m or more.

[12] The metasurface structure according to any one of [1] to

[11] above, wherein the conductive portion is made of an aggregate of metal nanoparticles.

[13] The metasurface structure according to any one of [1] to

[12] above, wherein the cross-sectional shape of the concave portion of the concave-convex structure is approximately rectangular.

[14] The metasurface structure according to any one of [1] to

[13] above, wherein the substrate is a glass substrate or a resin substrate.

[15] The metasurface structure according to any one of [1] to

[14] above, wherein the resin portion is formed by curing a photosensitive resin composition containing (A) a photopolymerization initiator, (B) an alkali-soluble resin, (C) a photopolymerizable compound, and (D) a liquid-repellent agent.

[16] The metasurface structure according to

[15] above, wherein the content of the liquid-repellent agent (D) in the solid content of the photosensitive resin composition is 0.01 mass % or more.

[17] A method for manufacturing a metasurface structure, comprising the following steps (1) to (3): (1) A coating step of coating a substrate with a photosensitive resin composition containing (A) a photopolymerization initiator, (B) an alkali-soluble resin, (C) a photopolymerizable compound, and (D) a liquid-repellent agent. (2) A resin part formation step of exposing the substrate coated with the photosensitive resin composition obtained in the coating step and then developing it to form a resin part having a concave-convex structure. (3) A conductive part formation step of coating a composition containing a conductive material into the concave-convex structure obtained in the resin part formation step.

[18] A method for manufacturing a metasurface structure according to

[17] above, wherein in step (3), the composition containing the conductive material is applied using an inkjet printer.

[19] A method for manufacturing a metasurface structure according to

[17] above, wherein in step (3), the composition containing the conductive material is applied using a screen for screen printing.

[20] A method for manufacturing a metasurface structure according to

[17] above, wherein in step (3), the composition containing the conductive material is applied using a bar coater.

[21] The method for manufacturing the metasurface structure according to

[17] above, wherein in the step (3), the composition containing the conductive material is applied using a spin coater.

[22] The method for manufacturing the metasurface structure according to

[17] above, wherein in the step (3), the composition containing the conductive material is applied using an air knife.

[23] The method for manufacturing the metasurface structure according to

[17] above, wherein in the step (3), the composition containing the conductive material is applied using a pressing substrate.

[24] The method for manufacturing a metasurface structure according to any one of

[17] to

[23] above, wherein in the step (3), the composition containing the conductive material is heated at 100°C or higher within 40 minutes after application and dried.

[25] The method for manufacturing a metasurface structure according to any one of

[17] to

[24] above, wherein in the step (3), the composition containing the conductive material contains a solvent having a boiling point of 180°C or higher.

[0008] According to the present invention, a metasurface structure having a fine pattern of conductive material can be provided.

[0009] 1 is a schematic diagram showing a metasurface structure of the present invention; FIG. 2 is a diagram showing the shape of the conductive portion of the conductive portion pattern for the metasurface;

[0010] Next, an example of an embodiment of the present invention will be described, but the present invention is not limited to the embodiment described below.

[0011] [Metasurface Structure] The metasurface structure of the present invention is a structure having a metasurface structure. A "metasurface structure" is a structure that exhibits unique electromagnetic properties in response to incident electromagnetic waves by having a plurality of arranged microstructures. The metasurface structure of the present invention will be specifically described with reference to FIG. 1. The metasurface structure 10 of the present invention comprises a resin portion 11, a conductive portion 12, and a substrate 13. The resin portion 11 forms a concave-convex structure on the substrate 13, and the convex surfaces of the concave-convex structure are liquid-repellent. The conductive portion 12 is formed by filling at least a portion of the concave portions of the concave-convex structure with a conductive material. Note that in FIG. 1, the liquid-repellent portions of the convex surfaces are referred to as liquid-repellent portions 14. Each of the constituent elements will be described in detail below.

[0012] <Resin Portion> As shown in FIG. 1 , the resin portion 11 has a concave-convex structure formed on the substrate 13. The surfaces of the convex portions are liquid-repellent, and this liquid-repellent property of the convex portions allows the conductive material to be efficiently filled into the concave portions. For example, when the conductive material is applied using an inkjet method, the conductive material is repelled by the liquid-repellent agent and moves to the concave portions, allowing the concave portions to be efficiently filled. From the perspective of efficiently filling the concave portions with the conductive material, it is preferable that the upper and wall surfaces of the convex portions are liquid-repellent, and it is more preferable that only the upper surfaces of the convex portions are liquid-repellent. Furthermore, the embodiment in which the "resin portion forms a concave-convex structure on the substrate" includes both an embodiment in which the concave portions are formed only from the resin portion and an embodiment in which the resin portion and the substrate surface form a concave portion. More specifically, an embodiment in which the bottom surface of the concave portion is the substrate surface and the side surface of the concave portion is made of resin. The method for manufacturing the concave-convex structure of the resin portion will be described in detail later.

[0013] Preferably, at least a part of the bottom surface of the recess is the surface of the substrate, and the side surface of the recess is made of a resin part, and more preferably, the entire bottom surface is the surface of the substrate, and the side surface of the recess is made of a resin part. In this embodiment, electromagnetic waves incident on the surface of the conductive part cause resonance due to only the conductive properties and shape pattern of the conductive part, making it easier to obtain high performance characteristics such as absorption, reflection, and transmission in a targeted frequency band.

[0014] The height of the convex portions of the uneven structure is not particularly limited as long as it is a height that allows the conductive material to be sufficiently filled in the concave portions, but is preferably 10 nm or more. If it is 10 nm or more, the conductive material can be sufficiently filled in the concave portions. From the above perspective, the height of the convex portions is more preferably 50 nm or more, and even more preferably 100 nm or more. On the other hand, considering the smoothness of the surface of the metasurface, the upper limit of the height of the convex portions is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 10 μm or less. In this specification, the height of the convex portions refers to the distance from the surface of the substrate to the highest part of the convex portions.

[0015] Furthermore, it is preferable that the cross-sectional shape of the recesses in the uneven structure is approximately rectangular. Here, the cross-sectional shape refers to the shape of the recesses formed by the side surfaces of adjacent resin portions and the substrate, and the lines connecting the two vertices of the adjacent resin portions in FIG. 1 , and this shape is approximately rectangular. The term "approximately rectangular" means that the side surfaces of the resin portions do not necessarily need to be at 90 degrees to the substrate. This also includes rectangular shapes in which the side surfaces of the resin portions are tapered due to the accuracy of exposure in photolithography. By having the recesses have an approximately rectangular shape, a sufficient amount of conductive material is filled, ensuring conductivity. Furthermore, an approximately rectangular cross-sectional shape can be easily manufactured by photolithography, which is advantageous in terms of high productivity.

[0016] The resin portion is preferably obtained by curing a photosensitive resin composition containing (A) a photopolymerization initiator, (B) an alkali-soluble resin, (C) a photopolymerizable compound, and (D) a liquid repellent agent (hereinafter referred to as the "photosensitive resin composition of the present invention.") Each element constituting the photosensitive resin composition will be described in detail below.

[0017] (A) Photopolymerization initiator The photopolymerization initiator is a compound that polymerizes the ethylenically unsaturated bond of the photopolymerizable compound (C) by actinic rays. The photopolymerization initiator (A) in the photosensitive resin composition of the present invention preferably contains a photopolymerization initiator represented by the following general formula (I) (hereinafter, may be referred to as "photopolymerization initiator (a1)").

[0018]

[0019] (In formula (I), R １ａ represents an alkyl group which may have a substituent, or an aromatic ring group which may have a substituent. ２ａ represents an alkyl group. ３ａ represents a monovalent substituent, n represents 0 or 1, and h represents an integer of 0 to 2.

[0020] The photopolymerization initiator (a1) has a sulfide skeleton, which allows for suitable curing of the surface and facilitates the formation of irregularities of a desired height. ２ａis an alkyl group, and the mobility of the generated radicals is high, making it possible to sufficiently retain the liquid repellent agent near the tips of the convex portions of the uneven structure, and it is thought that this makes it possible to prevent the conductive material from climbing up onto the convex portions during application.

[0021] R in the above formula (I) １ａ The alkyl group in the formula (I) may be linear, branched, cyclic, or a bonded group thereof. The number of carbon atoms in the alkyl group is not particularly limited, but is usually 1 or more, preferably 20 or less, more preferably 10 or less, even more preferably 6 or less, and even more preferably 2 or less. By setting the number of carbon atoms below the upper limit, internal curability tends to be enhanced. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, an isopentyl group, a hexyl group, a cyclopentyl group, a cyclohexyl group, a cyclopentylmethyl group, a cyclopentylethyl group, a cyclohexylmethyl group, and a cyclohexylethyl group. Among these, from the viewpoint of internal curability, a methyl group, a hexyl group, an isopentyl group, a cyclopentylmethyl group, and a cyclohexylmethyl group are preferred, and a methyl group is more preferred. Examples of substituents that the alkyl group may have include an aromatic ring group, a hydroxyl group, and a carboxy group. From the viewpoint of ease of synthesis, unsubstituted alkyl groups are preferred.

[0022] R in the above formula (I) １ａExamples of the aromatic ring group in (I) include an aromatic hydrocarbon ring group and an aromatic heterocyclic group. The number of carbon atoms in the aromatic ring group is not particularly limited, but is preferably 4 or more, more preferably 5 or more, and preferably 30 or less, more preferably 20 or less, and even more preferably 12 or less. The upper and lower limits can be arbitrarily combined, for example, 4 to 30 is preferred, 5 to 20 is more preferred, and 5 to 12 is even more preferred. By setting the number at or above the lower limit, solubility in solvents tends to be good. Furthermore, by setting the number at or below the upper limit, internal curability tends to be high. Examples of aromatic ring groups include a phenyl group, a naphthyl group, a pyridyl group, and a furyl group. Among these, from the viewpoint of developability, a phenyl group and a naphthyl group are preferred, and a phenyl group is more preferred. Examples of substituents that the aromatic ring group may have include a hydroxyl group and an alkyl group, and from the viewpoint of developability, an alkyl group is preferred. Among these, from the viewpoint of internal curability, R １ａ is preferably an alkyl group which may have a substituent.

[0023] R in the above formula (I) ２ａ The alkyl group in may be linear, branched, or cyclic, or may be a combination of these. The number of carbon atoms in the alkyl group is not particularly limited, but is usually 1 or more, preferably 5 or less, more preferably 3 or less, and even more preferably 2 or less. By setting the number of carbon atoms to the upper limit or less, internal curability tends to be enhanced. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a pentyl group, and among these, a methyl group is preferred from the viewpoint of internal curability.

[0024] R in the above formula (I) ３ａ The monovalent substituent in R is not particularly limited, but from the viewpoint of developability, ４ａ -O-, R ４ａ -(C=O)- is preferred. ４ａ Examples of R include an alkyl group which may have a substituent and an aromatic ring group which may have a substituent. ４ａThe alkyl group in the formula (I) may be linear, branched, or cyclic, or may be a combination thereof. The number of carbon atoms in the alkyl group is not particularly limited, but is typically 1 or more, preferably 2 or more, and preferably 8 or less, more preferably 5 or less, and even more preferably 3 or less. The upper and lower limits can be arbitrarily combined; for example, 1 to 8 is preferred, 1 to 5 is more preferred, 1 to 3 is even more preferred, and 2 to 3 is particularly preferred. Setting the number at or above the lower limit tends to facilitate synthesis. Setting the number at or below the upper limit tends to improve developability. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a pentyl group. Among these, from the viewpoint of developability, a methyl group and an ethyl group are preferred, and an ethyl group is more preferred. Examples of substituents that the alkyl group may have include a hydroxyl group and a carboxyl group, and from the viewpoint of developability, a hydroxyl group is preferred.

[0025] R ４ａ Examples of the aromatic ring group in formula (I) include an aromatic hydrocarbon ring group and an aromatic heterocyclic group. The number of carbon atoms in the aromatic ring group is not particularly limited, but is usually 4 or more, preferably 5 or more, and preferably 30 or less, more preferably 20 or less, and even more preferably 12 or less. The upper and lower limits can be arbitrarily combined, and for example, 4 to 30 is preferred, 5 to 20 is more preferred, and 5 to 12 is even more preferred. Setting the number at or above the lower limit tends to facilitate synthesis. Setting the number at or below the upper limit tends to improve developability. Examples of aromatic ring groups include a phenyl group, a naphthyl group, a thienyl group, a furyl group, a benzothienyl group, and a benzofuryl group. Among these, from the viewpoint of sensitivity, a benzothienyl group and a benzofuryl group are preferred, and a benzofuryl group is more preferred. Examples of substituents that the aromatic ring group may have include an alkyl group, a hydroxyl group, and a carboxy group, and from the viewpoint of synthesis, unsubstituted groups are preferred. R in formula (I) above ３ａ From the viewpoint of proper internal curing, the monovalent substituent in ４ａ is a hydroxyl-substituted ethyl group; ４ａ -O-, R ４ａ is a benzofuryl group ４ａ-(C=O)- is preferred, and R ４ａ is a hydroxyl-substituted ethyl group; ４ａ —O— is more preferred.

[0026] In the above formula (I), n represents 0 or 1. From the viewpoint of appropriate internal curing, n is preferably 1. From the viewpoint of ease of synthesis, n is preferably 0. In the above formula (I), h represents an integer of 0 to 2. From the viewpoint of developability, h is preferably 0 or 1, and more preferably 1. When h is an integer of 1 or more, R ３ａ The substitution position of is not particularly limited, but from the viewpoint of synthesis, the o-position or p-position is preferred, and the p-position is more preferred.

[0027] Specific examples of known compounds as the photopolymerization initiator (a1) include the following.

[0028]

[0029] Among these, the compound represented by formula (a1-3) is preferred from the viewpoint of appropriate internal curing properties.

[0030] The photopolymerization initiator (A) in the photosensitive resin composition of the present invention may further contain a photopolymerization initiator other than the photopolymerization initiator (a1) (hereinafter, this may be referred to as "another photopolymerization initiator (a2)"). As the other photopolymerization initiator (a2), a photopolymerization initiator commonly used in this field can be used. Examples of such photopolymerization initiators include hexaarylbiimidazole-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, oxime ester-based photopolymerization initiators other than the photopolymerization initiator (a1), triazine-based photopolymerization initiators, acetophenone-based photopolymerization initiators, and benzophenone-based photopolymerization initiators.

[0031] The content of the photopolymerization initiator (A) in the photosensitive resin composition of the present invention is not particularly limited, but is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 1.5% by mass or more, and particularly preferably 2% by mass or more, based on the total solid content of the photosensitive resin composition. Also, it is preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 6% by mass or less, and particularly preferably 4% by mass or less. By setting it to the lower limit or more, a coating film tends to be formed easily without film loss during development, and sufficient liquid repellency tends to be obtained. Also, by setting it to the upper limit or less, a desired pattern shape tends to be formed easily.

[0032] <Explanation of Terms> In the present invention, "total solids" means the amount of all components other than the solvent in the photosensitive resin composition. Even if a component other than the solvent is liquid at room temperature, that component is not included in the solvent but is included in the total solids. "(Meth)acrylic" means "either one or both of acrylic and methacrylic." A numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. "Weight average molecular weight" means the weight average molecular weight (Mw) calculated in terms of polystyrene by GPC (gel permeation chromatography). "Acid value" means the acid value calculated in terms of effective solids, unless otherwise specified, and is calculated by neutralization titration.

[0033] The blending ratio of the (A) photopolymerization initiator to the (C) photopolymerizable compound in the photosensitive resin composition is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, per 100 parts by mass of the (C) photopolymerizable compound. Also, the blending ratio is preferably 200 parts by mass or less, more preferably 100 parts by mass or less, even more preferably 50 parts by mass or less, and even more preferably 20 parts by mass or less. Setting the blending ratio at or above the lower limit tends to provide appropriate sensitivity, while setting the blending ratio at or below the upper limit tends to facilitate the formation of a desired pattern shape. A sensitizer may also be used in combination with the (A) photopolymerization initiator. The sensitizer improves sensitivity, while simultaneously reducing light transmittance into the interior of the photosensitive resin composition, which tends to increase the taper angle.

[0034] (B) Alkali-soluble resin The alkali-soluble resin is not particularly limited as long as it is a resin that can be developed with an alkali developer. Examples of the alkali-soluble resin include various resins containing a carboxy group and / or a hydroxyl group. Among them, a resin having a carboxy group is preferred from the viewpoints of obtaining convex portions with an appropriate taper angle, suppressing outflow of the liquid repellent agent due to thermal melting of the convex portion surface during post-baking, and maintaining liquid repellency.

[0035] [Alkali-soluble resin (b) having an ethylenic double bond] In the photosensitive resin composition of the present invention, the alkali-soluble resin (B) preferably contains an alkali-soluble resin (b) having an ethylenic double bond (hereinafter, sometimes abbreviated as "alkali-soluble resin (b)"). By containing the alkali-soluble resin (b) having an ethylenic double bond, sensitivity tends to be increased and the liquid repellency of the convex portions of the resulting uneven structure tends to be increased by suppressing the outflow of the liquid repellent agent during development. The specific structure of the alkali-soluble resin (b) having an ethylenic double bond is not particularly limited, but from the viewpoint of solubility in development, an epoxy (meth)acrylate resin (b1) and / or an acrylic copolymer resin (b2) is preferred.

[0036] <Epoxy (meth)acrylate resin (b1)> The epoxy (meth)acrylate resin (b1) is a resin obtained by adding an acid or ester compound having an ethylenically unsaturated bond (ethylenic double bond) to an epoxy resin, and then adding a polybasic acid or its anhydride. For example, a resin obtained by ring-opening addition of a carboxy group of an acid having an ethylenically unsaturated bond to the epoxy group of the epoxy resin, thereby adding an ethylenically unsaturated bond to the epoxy resin via an ester bond (—COO—), and adding one carboxy group of a polybasic acid anhydride to the hydroxyl group generated during this process. Another example is a resin obtained by simultaneously adding a polyhydric alcohol when adding the polybasic acid anhydride. Furthermore, a resin obtained by reacting a compound having a functional group that can further react with the carboxy group of the resin obtained by the above reaction is also included in the epoxy (meth)acrylate resin (b1).

[0037] Here, the term "epoxy resin" refers to raw material compounds before they are thermoset to form a resin, and the epoxy resin can be appropriately selected from known epoxy resins. Furthermore, the epoxy resin can be a compound obtained by reacting a phenolic compound with an epihalohydrin. The phenolic compound is preferably a compound having a divalent or higher phenolic hydroxyl group, and may be a monomer or a polymer. Specific examples include bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, biphenyl novolac epoxy resins, trisphenol epoxy resins, epoxidized polymers of phenol and dicyclopentane, dihydroxylfluorene epoxy resins, dihydroxylalkyleneoxylfluorene epoxy resins, diglycidyl ethers of 9,9-bis(4'-hydroxyphenyl)fluorene, and diglycidyl ethers of 1,1-bis(4'-hydroxyphenyl)adamantane, and those having an aromatic ring in the main chain are preferably used. Among these, from the viewpoint of cured film strength, bisphenol A epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, epoxidized polymers of phenol and dicyclopentadiene, and diglycidyl ethers of 9,9-bis(4'-hydroxyphenyl)fluorene are preferred, with bisphenol A epoxy resins being more preferred.

[0038] Examples of acids having an ethylenically unsaturated bond include (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, citraconic acid, pentaerythritol tri(meth)acrylate succinic anhydride adduct, pentaerythritol tri(meth)acrylate tetrahydrophthalic anhydride adduct, dipentaerythritol penta(meth)acrylate succinic anhydride adduct, dipentaerythritol penta(meth)acrylate phthalic anhydride adduct, dipentaerythritol penta(meth)acrylate tetrahydrophthalic anhydride adduct, and reaction products of (meth)acrylic acid and ε-caprolactone. Among these, (meth)acrylic acid is preferred from the viewpoint of sensitivity.

[0039] Examples of polybasic acids (anhydrides) include succinic acid, maleic acid, itaconic acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, biphenyltetracarboxylic acid, and anhydrides thereof. These may be used alone or in combination of two or more. Among these, from the viewpoint of reducing residues after development, succinic anhydride, maleic anhydride, and itaconic anhydride are preferred, and succinic anhydride is more preferred.

[0040] The use of a polyhydric alcohol increases the molecular weight of the epoxy (meth)acrylate resin (b1), allowing for the introduction of branches into the molecule, making it easier to balance molecular weight and viscosity. It also increases the rate of acid group introduction into the molecule, making it easier to balance sensitivity, adhesion, and the like. Examples of polyhydric alcohols include trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, trimethylolethane, and 1,2,3-propanetriol. These may be used alone or in combination of two or more.

[0041] The acid value of the epoxy (meth)acrylate resin (b1) is not particularly limited, but is preferably 10 mgKOH / g or more, more preferably 20 mgKOH / g or more, even more preferably 40 mgKOH / g or more, still more preferably 60 mgKOH / g or more, and is preferably 200 mgKOH / g or less, more preferably 180 mgKOH / g or less, even more preferably 150 mgKOH / g or less, still more preferably 120 mgKOH / g or less, and particularly preferably 100 mgKOH / g or less.

[0042] The weight-average molecular weight (Mw) of the epoxy (meth)acrylate resin (b1) is not particularly limited, but is preferably 1,000 or more, more preferably 2,000 or more, even more preferably 3,000 or more, even more preferably 4,000 or more, particularly preferably 5,000 or more, particularly preferably 6,000 or more, and most preferably 7,000 or more. It is also preferably 30,000 or less, more preferably 20,000 or less, even more preferably 15,000 or less, and particularly preferably 10,000 or less. By setting it to be equal to or greater than the lower limit, a highly robust uneven structure can be formed. By setting it to be equal to or less than the upper limit, the uneven structure can be easily formed, thereby increasing productivity. When the (B) alkali-soluble resin contains the epoxy (meth)acrylate resin (b1), the content of the epoxy (meth)acrylate resin (b1) is not particularly limited, but is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. The content is usually 100% by mass or less. By making the content equal to or greater than the lower limit, a highly robust concave-convex structure can be formed.

[0043] The epoxy (meth)acrylate resin (b1) can be synthesized by a conventional method. Specifically, a method can be used in which the epoxy resin is dissolved in an organic solvent, and in the presence of a catalyst and a thermal polymerization inhibitor, an acid or ester compound having an ethylenically unsaturated bond is added to cause an addition reaction, and then a polybasic acid or its anhydride is added to continue the reaction. Examples of organic solvents include methyl ethyl ketone, cyclohexanone, diethylene glycol ethyl ether acetate, and propylene glycol monomethyl ether acetate. Examples of catalysts include tertiary amines such as triethylamine, benzyldimethylamine, and tribenzylamine; quaternary ammonium salts such as tetramethylammonium chloride, methyltriethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, and trimethylbenzylammonium chloride; phosphorus compounds such as triphenylphosphine; and stibines such as triphenylstibine. Examples of thermal polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, and methylhydroquinone. These may be used alone or in combination of two or more.

[0044] The acid or ester compound having an ethylenically unsaturated bond can be used in an amount that is preferably 0.7 to 1.3 chemical equivalents, more preferably 0.9 to 1.1 chemical equivalents, per chemical equivalent of the epoxy group of the epoxy resin. The temperature during the addition reaction is preferably 60 to 150°C, more preferably 80 to 120°C. The polybasic acid (anhydride) can be used in an amount that is preferably 0.1 to 1.2 chemical equivalents, more preferably 0.2 to 1.1 chemical equivalents, per chemical equivalent of the hydroxyl group generated by the addition reaction.

[0045] From the viewpoint of obtaining good development solubility, the epoxy(meth)acrylate resin (b1) preferably contains at least one selected from the group consisting of an epoxy(meth)acrylate resin (b1-1) containing a partial structure represented by the following general formula (i) (hereinafter may be referred to as "epoxy(meth)acrylate resin (b1-1)"), an epoxy(meth)acrylate resin (b1-2) containing a partial structure represented by the following general formula (ii) (hereinafter may be referred to as "epoxy(meth)acrylate resin (b1-2)"), and an epoxy(meth)acrylate resin (b1-3) containing a partial structure represented by the following general formula (iii) (hereinafter may be referred to as "epoxy(meth)acrylate resin (b1-3)"): Among these, from the viewpoint of obtaining good development solubility, the epoxy (meth)acrylate resin (b1) preferably contains an epoxy (meth)acrylate resin (b1-1) containing a partial structure represented by the following general formula (i), and more preferably an epoxy (meth)acrylate resin (b1-1) containing a partial structure represented by the following general formula (i): One of the reasons for this is presumed to be that the resin has a rigid main skeleton and is therefore less susceptible to thermal decomposition.

[0046]

[0047] In formula (i), R ａ represents a hydrogen atom or a methyl group, R ｂ represents a divalent hydrocarbon group which may have a substituent. The benzene ring in formula (i) may be further substituted with any substituent. * represents a bond.

[0048] In the formula (i), R ｂrepresents a divalent hydrocarbon group which may have a substituent. Examples of divalent hydrocarbon groups include divalent aliphatic groups, divalent aromatic cyclic groups, and groups in which one or more divalent aliphatic groups are linked to one or more divalent aromatic cyclic groups. Examples of divalent aliphatic groups include linear, branched, and cyclic groups. Among these, linear groups are preferred from the viewpoint of development solubility, while cyclic groups are preferred from the viewpoint of reducing developer penetration into exposed areas. The number of carbon atoms is usually 1 or more, preferably 3 or more, more preferably 6 or more, and preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. By setting the carbon number at or above the lower limit, development adhesion tends to be improved. On the other hand, by setting the carbon number at or below the upper limit, developer penetration can be reduced.

[0049] Examples of divalent linear aliphatic groups include methylene, ethylene, n-propylene, n-butylene, n-hexylene, and n-heptylene. Among these, methylene is preferred from the viewpoint of developer solubility. Examples of divalent branched aliphatic groups include structures having a methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, or tert-butyl group as a side chain in the aforementioned divalent linear aliphatic group. The number of rings in the divalent cyclic aliphatic group is not particularly limited, but is typically 1 or more, preferably 2 or more, and preferably 10 or less, and more preferably 5 or less. Setting the number at or above the lower limit tends to improve the film remaining rate. Setting the number at or below the upper limit can improve developer solubility. As the divalent cyclic aliphatic group, for example, a group in which two hydrogen atoms have been removed from a cyclohexane ring, a cycloheptane ring, a cyclodecane ring, a cyclododecane ring, a norbornane ring, an isobornane ring, or an adamantane ring is preferred.

[0050] Examples of substituents that the divalent aliphatic group may have include alkoxy groups having 1 to 5 carbon atoms, such as a methoxy group or an ethoxy group; a hydroxyl group; a nitro group; a cyano group; and a carboxy group. From the viewpoint of ease of synthesis, unsubstituted groups are preferred. Examples of divalent aromatic ring groups include divalent aromatic hydrocarbon ring groups and divalent aromatic heterocyclic groups. The number of carbon atoms is usually 4 or more, preferably 5 or more, more preferably 6 or more, and preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. By setting the carbon number at or above the lower limit, development adhesion tends to be improved. Meanwhile, by setting the carbon number at or below the upper limit, good development solubility can be obtained. The aromatic hydrocarbon ring in the divalent aromatic hydrocarbon ring group may be a monocyclic or fused ring. Examples of the divalent aromatic hydrocarbon ring group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring, each of which has two free valences.

[0051] The aromatic heterocycle in the divalent aromatic heterocyclic group may be a single ring or a condensed ring. Examples of the divalent aromatic heterocyclic group include a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, and an azulene ring, each of which has two free valences. Among these, from the viewpoint of photocurability, a benzene ring or a naphthalene ring having two free valences is preferred, and a benzene ring having two free valences is more preferred.

[0052] Examples of the substituent that the divalent aromatic ring group may have include a hydroxy group, a methyl group, a methoxy group, an ethyl group, an ethoxy group, a propyl group, a propoxy group, and a glycidyl ether group. Among these, from the viewpoint of curability, unsubstituted groups are preferred.

[0053] Examples of the group linking one or more divalent aliphatic groups with one or more divalent aromatic groups include a group linking one or more of the above-mentioned divalent aliphatic groups with one or more of the above-mentioned divalent aromatic ring groups. The number of divalent aliphatic groups is not particularly limited, but is usually 1 or more, preferably 2 or more, and also preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. By setting the number to be equal to or greater than the lower limit, development adhesion tends to be improved. Meanwhile, by setting the number to be equal to or less than the upper limit, good development solubility can be obtained. The number of divalent aromatic ring groups is not particularly limited, but is usually 1 or more, preferably 2 or more, and also preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. By setting the number to be equal to or greater than the lower limit, development adhesion tends to be improved. Meanwhile, by setting the number to be equal to or less than the upper limit, good development solubility can be obtained.

[0054] Examples of the group formed by linking one or more divalent aliphatic groups with one or more divalent aromatic ring groups include groups represented by the following formulae (i-A) to (i-F). Among these, the group represented by the following formula (i-A) is preferred from the viewpoints of the rigidity of the skeleton and the hydrophobicity of the film. * in the chemical formula represents a bond.

[0055]

[0056] As described above, the benzene ring in formula (i) may be further substituted with any substituent. Examples of the substituent on the benzene ring in formula (i) include a hydroxy group, a methyl group, a methoxy group, an ethyl group, an ethoxy group, a propyl group, and a propoxy group. The number of substituents is not particularly limited, and may be one or two or more as long as it is chemically acceptable. From the viewpoint of curability, non-substitution is preferred.

[0057] From the viewpoint of development solubility, the partial structure represented by the formula (i) is preferably a partial structure represented by the following formula (i-1):

[0058]

[0059] In formula (i-1), R ａ and R ｂ has the same meaning as that in formula (i). １ represents a divalent hydrocarbon group having 1 to 4 carbon atoms which may have a substituent. * represents a bond. The benzene ring in formula (i-1) may be further substituted with any substituent.

[0060] In the general formula (i-1), R １ represents a divalent hydrocarbon group having 1 to 4 carbon atoms which may have a substituent. Examples of the divalent hydrocarbon group include an alkylene group and an alkenylene group.

[0061] The alkylene group may be linear or branched, but is preferably linear from the viewpoint of development solubility. The number of carbon atoms is not particularly limited, but is usually 1 or more, preferably 2 or more, and preferably 4 or less, more preferably 3 or less. By making the number equal to or greater than the lower limit, the residual film ratio tends to be high. Furthermore, by making the number equal to or less than the upper limit, development solubility becomes good. Specific examples of the alkylene group include a methylene group, an ethylene group, a propylene group, and a butylene group. From the viewpoint of development solubility, a methylene group or an ethylene group is preferred, and an ethylene group is more preferred.

[0062] The alkenylene group may be linear or branched, but is preferably linear from the viewpoint of development solubility. The number of carbon atoms is not particularly limited, but is usually 2 or more, preferably 4 or less, and more preferably 3 or less. By making the number equal to or greater than the lower limit, the residual film ratio tends to be high. On the other hand, by making the number equal to or less than the upper limit, development solubility becomes good. Specific examples of the alkenylene group include an ethenylene group, a propenylene group, and a butylene group, and from the viewpoint of development solubility, an ethenylene group is preferred.

[0063] The substituent that the divalent hydrocarbon group having 1 to 4 carbon atoms may have is not particularly limited, but examples thereof include a halogen atom, an alkoxy group, a benzoyl group, and a hydroxyl group. From the viewpoint of ease of synthesis, no substitution is preferred. Among these, from the viewpoint of obtaining good developer solubility, R １is preferably a divalent alkylene group having 1 to 4 carbon atoms, more preferably a methylene group or an ethylene group, and even more preferably an ethylene group.

[0064] The partial structure represented by formula (i-1) contained in one molecule of the epoxy (meth)acrylate resin (b1-1) may be one type or two or more types. The number of partial structures represented by formula (i) contained in one molecule of the epoxy (meth)acrylate resin (b1-1) is not particularly limited, but is preferably one or more, more preferably two or more, even more preferably three or more, and is preferably 10 or less, even more preferably eight or less. By making the number equal to or greater than the lower limit, development adhesion tends to be improved. Meanwhile, by making the number equal to or less than the upper limit, good development solubility can be obtained.

[0065] The number of partial structures represented by the formula (i-1) contained in one molecule of the epoxy (meth)acrylate resin (b1-1) is not particularly limited, but is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, and is preferably 10 or less, even more preferably 8 or less. By making the number equal to or greater than the lower limit, development adhesion tends to be improved. On the other hand, by making the number equal to or less than the upper limit, good development solubility can be obtained.

[0066] Specific examples of the epoxy (meth)acrylate resin (b1-1) are listed below.

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074] In another embodiment, the epoxy (meth)acrylate resin (b1) is preferably an epoxy (meth)acrylate resin (b1-2) containing a partial structure represented by the following formula (ii) from the viewpoint of development adhesion.

[0075]

[0076] In formula (ii), R ｃ R each independently represents a hydrogen atom or a methyl group. ｄ represents a divalent hydrocarbon group having a cyclic hydrocarbon group as a side chain. * represents a bond. In the formula (ii), R ｄ represents a divalent hydrocarbon group having a cyclic hydrocarbon group as a side chain. Examples of the cyclic hydrocarbon group include an aliphatic cyclic group and an aromatic cyclic group.

[0077] The number of rings in the aliphatic cyclic group is not particularly limited, but is usually 1 or more, preferably 2 or more, and preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. By setting the number of rings at or above the lower limit, development adhesion tends to be improved. Furthermore, by setting the number of carbon atoms at or below the upper limit, good development solubility can be obtained. The number of carbon atoms in the aliphatic cyclic group is usually 4 or more, preferably 6 or more, more preferably 8 or more, and also preferably 40 or less, more preferably 30 or less, even more preferably 20 or less, and particularly preferably 15 or less. By setting the number of carbon atoms at or above the lower limit, development adhesion tends to be improved. Furthermore, by setting the number of carbon atoms at or below the upper limit, good development solubility can be obtained. Examples of the aliphatic ring in the aliphatic cyclic group include a cyclohexane ring, a cycloheptane ring, a cyclodecane ring, a cyclododecane ring, a norbornane ring, an isobornane ring, and an adamantane ring. Among these, an adamantane ring is preferred from the viewpoint of development adhesion.

[0078] The number of rings in the aromatic ring group is not particularly limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, and preferably 10 or less, more preferably 5 or less, and even more preferably 4 or less. By making the number equal to or greater than the lower limit, good developer solubility can be obtained. Furthermore, by making the number equal to or less than the upper limit, developer adhesion tends to be improved. Examples of the aromatic ring group include an aromatic hydrocarbon ring group and an aromatic heterocyclic group. The number of carbon atoms in the aromatic ring group is usually 4 or more, preferably 6 or more, more preferably 8 or more, even more preferably 10 or more, particularly preferably 12 or more, and also preferably 40 or less, more preferably 30 or less, even more preferably 20 or less, and particularly preferably 15 or less. By making the number equal to or greater than the lower limit, good developer solubility can be obtained. Furthermore, by making the number equal to or less than the upper limit, developer adhesion tends to be improved. Examples of the aromatic ring in the aromatic ring group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring. Among these, a fluorene ring is preferred from the viewpoint of patterning properties.

[0079] The divalent hydrocarbon group in the divalent hydrocarbon group having a cyclic hydrocarbon group as a side chain is not particularly limited, and examples thereof include a divalent aliphatic group, a divalent aromatic ring group, and a group in which one or more divalent aliphatic groups are linked to one or more divalent aromatic ring groups.

[0080] The divalent aliphatic group may be linear, branched, or cyclic. Among these, linear groups are preferred from the viewpoint of development solubility, while cyclic groups are preferred from the viewpoint of reducing the penetration of the developer into the exposed area. The number of carbon atoms is usually 1 or more, preferably 3 or more, more preferably 6 or more, and preferably 25 or less, more preferably 20 or less, and even more preferably 15 or less. By making the carbon number equal to or greater than the lower limit, development adhesion tends to be improved. On the other hand, by making the carbon number equal to or less than the upper limit, good development solubility can be obtained.

[0081] Examples of divalent linear aliphatic groups include methylene, ethylene, n-propylene, n-butylene, n-hexylene, and n-heptylene. Among these, a methylene group is preferred from the viewpoint of developer solubility. Examples of divalent branched aliphatic groups include structures having a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, or tert-butyl group as a side chain in the aforementioned divalent linear aliphatic group. The number of rings in the divalent cyclic aliphatic group is not particularly limited, but is typically 1 or more, preferably 2 or more, and preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. By setting the number at or above the lower limit, development adhesion tends to be improved. Furthermore, by setting the number at or below the upper limit, residue tends to be reduced.

[0082] Examples of the divalent cyclic aliphatic group include groups in which two hydrogen atoms have been removed from a cyclohexane ring, a cycloheptane ring, a cyclodecane ring, a cyclododecane ring, a norbornane ring, an isobornane ring, or an adamantane ring. Among these, from the viewpoint of development adhesion, groups in which two hydrogen atoms have been removed from an adamantane ring are preferred.

[0083] Examples of the substituent that the divalent aliphatic group may have include an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group or an ethoxy group; a hydroxyl group; a nitro group; a cyano group; and a carboxy group. From the viewpoint of ease of synthesis, an unsubstituted group is preferred.

[0084] Examples of the divalent aromatic ring group include a divalent aromatic hydrocarbon ring group and a divalent aromatic heterocyclic group. The number of carbon atoms is usually 4 or more, preferably 5 or more, more preferably 6 or more, and preferably 30 or less, more preferably 20 or less, and even more preferably 15 or less. By making the number of carbon atoms equal to or greater than the lower limit, development adhesion tends to be improved. On the other hand, by making the number of carbon atoms equal to or less than the upper limit, good development solubility can be obtained.

[0085] The aromatic hydrocarbon ring in the divalent aromatic hydrocarbon ring group may be a monocyclic ring or a condensed ring. Examples of the divalent aromatic hydrocarbon ring group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring, each of which has two free valences. The aromatic heterocyclic ring in the divalent aromatic heterocyclic group may be a monocyclic ring or a condensed ring. As the divalent aromatic heterocyclic group, for example, can be mentioned furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, cinnoline ring, quinoxaline ring, phenanthridine ring, perimidine ring, quinazoline ring, quinazolinone ring, azulene ring, which have two free valences.Among these, from the viewpoint of photocurability, the benzene ring and naphthalene ring are preferred, and the benzene ring having two free valences is more preferred.

[0086] Examples of substituents that the divalent aromatic ring group may have include a hydroxy group, a methyl group, a methoxy group, an ethyl group, an ethoxy group, a propyl group, and a propoxy group. Among these, from the viewpoint of curability, unsubstituted groups are preferred. Examples of groups linking one or more divalent aliphatic groups to one or more divalent aromatic ring groups include groups linking one or more of the above-mentioned divalent aliphatic groups to one or more of the above-mentioned divalent aromatic ring groups. The number of divalent aliphatic groups is not particularly limited, but is usually 1 or more, preferably 2 or more, and preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. By setting the number at or above the lower limit, development adhesion tends to be improved. Meanwhile, by setting the number at or below the upper limit, good development solubility can be obtained. The number of divalent aromatic ring groups is not particularly limited, but is usually 1 or more, preferably 2 or more, and preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. By setting the number at or above the lower limit, development adhesion tends to be improved. Meanwhile, by setting the number at or below the upper limit, good development solubility can be obtained.

[0087] Examples of the group formed by linking one or more divalent aliphatic groups with one or more divalent aromatic ring groups include groups represented by the formulae (i-A) to (i-F). Among these, the group represented by the formula (i-C) is preferred from the viewpoint of development solubility.

[0088] The bonding mode of the cyclic hydrocarbon group as a side chain to these divalent hydrocarbon groups is not particularly limited, but examples include a mode in which one hydrogen atom of an aliphatic group or an aromatic ring group is substituted with the side chain, and a mode in which one carbon atom of an aliphatic group is included to form the cyclic hydrocarbon group as a side chain.

[0089] From the viewpoint of development adhesion, the partial structure represented by the formula (ii) is preferably a partial structure represented by the following formula (ii-1):

[0090]

[0091] In formula (ii-1), R ｃ has the same meaning as in formula (ii). ａrepresents a monovalent cyclic hydrocarbon group which may have a substituent. n is an integer of 1 or more. The benzene ring in formula (ii-1) may be further substituted with an arbitrary substituent. * represents a bond. In formula (ii-1), R ａ represents a monovalent cyclic hydrocarbon group which may have a substituent. Examples of the cyclic hydrocarbon group include an aliphatic cyclic group and an aromatic cyclic group.

[0092] The number of rings in the aliphatic cyclic group is not particularly limited, but is usually 1 or more, preferably 2 or more, and preferably 6 or less, more preferably 4 or less, and even more preferably 3 or less. By setting the number of rings at or above the lower limit, development adhesion tends to be improved. By setting the number of carbon atoms at or below the upper limit, good development solubility can be obtained. The number of carbon atoms in the aliphatic cyclic group is usually 4 or more, preferably 6 or more, more preferably 8 or more, and preferably 40 or less, more preferably 30 or less, even more preferably 20 or less, and particularly preferably 15 or less. By setting the number of carbon atoms at or above the lower limit, development adhesion tends to be improved. By setting the number of carbon atoms at or below the upper limit, good development solubility can be obtained. Examples of the aliphatic ring in the aliphatic cyclic group include a cyclohexane ring, a cycloheptane ring, a cyclodecane ring, a cyclododecane ring, a norbornane ring, an isobornane ring, and an adamantane ring. Among these, an adamantane ring is preferred from the viewpoint of development adhesion.

[0093] The number of rings in the aromatic ring group is not particularly limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, and preferably 10 or less, more preferably 5 or less. By setting the number of rings at or above the lower limit, development adhesion tends to be improved. Furthermore, by setting the number of rings at or below the upper limit, good development solubility can be obtained. Examples of the aromatic ring group include an aromatic hydrocarbon ring group and an aromatic heterocyclic group. Furthermore, the number of carbon atoms in the aromatic ring group is usually 4 or more, preferably 5 or more, more preferably 6 or more, and preferably 30 or less, more preferably 20 or less, and even more preferably 15 or less. By setting the number of carbon atoms at or above the lower limit, development adhesion tends to be improved. Furthermore, by setting the number of carbon atoms at or below the upper limit, good development solubility can be obtained. Examples of aromatic rings in the aromatic ring group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and a fluorene ring. Among these, a fluorene ring is preferred from the viewpoint of development adhesion.

[0094] Examples of the substituent that the cyclic hydrocarbon group may have include alkyl groups having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an amyl group, and an isoamyl group; alkoxy groups having 1 to 5 carbon atoms, such as a methoxy group and an ethoxy group; a hydroxyl group; a nitro group; a cyano group; and a carboxy group. From the viewpoint of ease of synthesis, unsubstituted cyclic hydrocarbon groups are preferred.

[0095] n represents an integer of 1 or more, preferably 2 or more, and preferably 3 or less. For example, 1 to 3 is preferred, and 1 to 2 is more preferred. By making n equal to or greater than the lower limit, development adhesion tends to be improved. On the other hand, by making n equal to or less than the upper limit, good development solubility can be obtained.

[0096] Among these, from the viewpoint of strong film hardness, R ａis preferably a monovalent aliphatic cyclic group, and more preferably an adamantyl group. As described above, the benzene ring in formula (ii-1) may be further substituted with any substituent. Examples of the substituent include a hydroxy group, a methyl group, a methoxy group, an ethyl group, an ethoxy group, a propyl group, and a propoxy group. The number of substituents is not particularly limited, and may be one or two or more. From the viewpoint of curability, unsubstituted groups are preferred.

[0097] Specific examples of the partial structure represented by the formula (ii-1) are listed below.

[0098]

[0099]

[0100]

[0101]

[0102]

[0103] From the viewpoint of development adhesion, the partial structure represented by the formula (ii) is preferably a partial structure represented by the following formula (ii-2):

[0104]

[0105] In formula (ii-2), R ｃ has the same meaning as in formula (ii). β represents a divalent cyclic hydrocarbon group which may have a substituent. The benzene ring in formula (ii-2) may be further substituted with an arbitrary substituent. * represents a bond. In formula (ii-2), R β represents a divalent cyclic hydrocarbon group which may have a substituent. Examples of the cyclic hydrocarbon group include an aliphatic cyclic group and an aromatic cyclic group.

[0106] The number of rings in the aliphatic cyclic group is not particularly limited, but is usually 1 or more, preferably 2 or more, and preferably 10 or less, and more preferably 5 or less. By setting the number of rings at or above the lower limit, development adhesion tends to be improved. By setting the number of carbon atoms at or below the upper limit, good development solubility can be obtained. The number of carbon atoms in the aliphatic cyclic group is usually 4 or more, preferably 6 or more, more preferably 8 or more, and preferably 40 or less, more preferably 35 or less, and even more preferably 30 or less. By setting the number of carbon atoms at or above the lower limit, development adhesion tends to be improved. By setting the number of carbon atoms at or below the upper limit, good development solubility can be obtained. Examples of the aliphatic ring in the aliphatic cyclic group include a cyclohexane ring, a cycloheptane ring, a cyclodecane ring, a cyclododecane ring, a norbornane ring, an isobornane ring, and an adamantane ring. Among these, an adamantane ring is preferred from the viewpoint of development adhesion.

[0107] The number of rings in the aromatic ring group is not particularly limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, and preferably 10 or less, and more preferably 5 or less. By setting the number of rings at or above the lower limit, development adhesion tends to be improved. By setting the number of rings at or below the upper limit, good development solubility can be obtained. Examples of aromatic ring groups include aromatic hydrocarbon ring groups and aromatic heterocyclic groups. The number of carbon atoms in the aromatic ring group is usually 4 or more, preferably 6 or more, more preferably 8 or more, even more preferably 10 or more, and preferably 40 or less, more preferably 30 or less, even more preferably 20 or less, and particularly preferably 15 or less. By setting the number of carbon atoms at or above the lower limit, development adhesion tends to be improved. By setting the number of carbon atoms at or below the upper limit, good development solubility can be obtained. Examples of aromatic rings in the aromatic ring group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and a fluorene ring. Among these, a fluorene ring is preferred from the viewpoint of development adhesion.

[0108] Examples of the substituent that the cyclic hydrocarbon group may have include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, amyl, and isoamyl; alkoxy groups having 1 to 5 carbon atoms, such as methoxy and ethoxy; hydroxyl; nitro; cyano; and carboxyl. Of these, from the viewpoint of ease of synthesis, unsubstituted groups are preferred. Of these, from the viewpoint of curability, R β is preferably a divalent aliphatic ring group, and more preferably a divalent adamantane ring group. β is preferably a divalent aromatic ring group, and more preferably a divalent fluorene ring group.

[0109] As described above, the benzene ring in formula (ii-2) may be further substituted with any substituent. Examples of the substituent on the benzene ring in formula (ii-2) include a hydroxy group, a methyl group, a methoxy group, an ethyl group, an ethoxy group, a propyl group, and a propoxy group. The number of substituents is not particularly limited, and may be one or two or more. From the viewpoint of curability, unsubstituted rings are preferred.

[0110] Specific examples of the partial structure represented by the formula (ii-2) are listed below.

[0111]

[0112]

[0113]

[0114]

[0115] From the viewpoint of curability, the partial structure represented by the formula (ii) is preferably a partial structure represented by the following formula (ii-3):

[0116]

[0117] In formula (ii-3), R ｃ and R ｄ has the same meaning as in formula (ii). １has the same meaning as in formula (i-1). * represents a bond.

[0118] The partial structure represented by formula (ii-3) contained in one molecule of the epoxy (meth)acrylate resin (b1-2) may be one type or two or more types. The number of partial structures represented by formula (ii) contained in one molecule of the epoxy (meth)acrylate resin (b1-2) is not particularly limited, but is preferably one or more, more preferably three or more, and is preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. By making the number equal to or greater than the lower limit, development adhesion tends to be improved. Meanwhile, by making the number equal to or less than the upper limit, good development solubility can be obtained.

[0119] In yet another embodiment, the epoxy (meth)acrylate resin (b1) is preferably an epoxy (meth)acrylate resin (b1-3) containing a partial structure represented by the following general formula (iii), from the viewpoint of obtaining good development solubility:

[0120]

[0121] In formula (iii), R ｅ represents a hydrogen atom or a methyl group, and γ represents a single bond, -CO-, an alkylene group which may have a substituent, or a divalent cyclic hydrocarbon group which may have a substituent. The benzene ring in formula (iii) may be further substituted with an arbitrary substituent. * represents a bond. In the formula (iii), γ represents a single bond, -CO-, an alkylene group which may have a substituent, or a divalent cyclic hydrocarbon group which may have a substituent.

[0122] The alkylene group may be linear or branched; from the viewpoint of developer solubility, linear is preferred, and from the viewpoint of developer adhesion, branched is preferred. The number of carbon atoms is not particularly limited, but is generally 1 or more, preferably 2 or more, and preferably 6 or less, more preferably 4 or less. By setting the number at or above the lower limit, developer adhesion tends to be improved. By setting the number at or below the upper limit, good developer solubility can be obtained. Examples of alkylene groups include methylene, ethylene, propylene, butylene, hexylene, and heptylene. From the viewpoint of achieving both developer adhesion and developer solubility, methylene, ethylene, and propylene are preferred, and dimethylmethylene (2,2-propylene) is more preferred. Examples of substituents that the alkylene group may have include alkoxy groups having 1 to 5 carbon atoms, such as methoxy and ethoxy; hydroxyl; nitro; cyano; and carboxyl. From the viewpoint of achieving both developer adhesion and developer solubility, unsubstituted groups are preferred.

[0123] Examples of the divalent cyclic hydrocarbon group include a divalent aliphatic cyclic group or a divalent aromatic cyclic group. The number of rings in the aliphatic cyclic group is not particularly limited, but is typically 1 or more, preferably 2 or more, and preferably 10 or less, more preferably 5 or less. By setting the number of rings at or above the lower limit, development adhesion tends to be improved. By setting the number of carbon atoms at or below the upper limit, good development solubility can be obtained. The number of carbon atoms in the aliphatic cyclic group is typically 4 or more, preferably 6 or more, more preferably 8 or more, and preferably 40 or less, more preferably 35 or less, and even more preferably 30 or less. By setting the number of carbon atoms at or above the lower limit, development adhesion tends to be improved. By setting the number of carbon atoms at or below the upper limit, good development solubility can be obtained. Examples of the aliphatic ring in the aliphatic cyclic group include a cyclohexane ring, a cycloheptane ring, a cyclodecane ring, a cyclododecane ring, a norbornane ring, an isobornane ring, and an adamantane ring. Among these, an adamantane ring is preferred from the viewpoint of development adhesion.

[0124] The number of rings in the aromatic ring group is not particularly limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, and preferably 10 or less, more preferably 5 or less. By setting the number of rings at or above the lower limit, development adhesion tends to be improved. Furthermore, by setting the number of rings at or below the upper limit, good development solubility can be obtained. Examples of aromatic ring groups include aromatic hydrocarbon ring groups and aromatic heterocyclic groups. The number of carbon atoms in the aromatic ring group is usually 4 or more, preferably 6 or more, more preferably 8 or more, even more preferably 10 or more, and preferably 40 or less, more preferably 30 or less, even more preferably 20 or less, and particularly preferably 15 or less. By setting the number of carbon atoms at or above the lower limit, development adhesion tends to be improved. Furthermore, by setting the number of carbon atoms at or below the upper limit, good development solubility can be obtained. Examples of aromatic rings in the aromatic ring group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and a fluorene ring. Among these, a fluorene ring is preferred from the viewpoint of development adhesion.

[0125] Examples of the substituent that the cyclic hydrocarbon group may have include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, amyl, and isoamyl; alkoxy groups having 1 to 5 carbon atoms, such as methoxy and ethoxy; hydroxyl; nitro; cyano; and carboxyl groups. From the viewpoint of ease of synthesis, unsubstituted groups are preferred. Among these, from the viewpoint of developer solubility, γ is preferably an alkylene group which may have a substituent, and more preferably dimethylmethylene.

[0126] As described above, the benzene ring in formula (iii) may be further substituted with any substituent. Examples of the substituent on the benzene ring in formula (iii) include a hydroxy group, a methyl group, a methoxy group, an ethyl group, an ethoxy group, a propyl group, and a propoxy group. The number of substituents is not particularly limited, and may be one or two or more. From the viewpoint of curability, non-substitution is preferred.

[0127] From the viewpoint of development solubility, the partial structure represented by the formula (iii) is preferably a partial structure represented by the following formula (iii-1):

[0128]

[0129] In formula (iii-1), R ｅ and γ have the same meaning as in formula (iii). １ has the same meaning as that of the formula (i-1). * represents a bond. The benzene ring in formula (iii-1) may be further substituted with any substituent.

[0130] The number of partial structures represented by the formula (iii) contained in one molecule of the epoxy (meth)acrylate resin (b1-3) is not particularly limited, but is preferably 1 or more, more preferably 5 or more, even more preferably 10 or more, and is preferably 18 or less, even more preferably 15 or less. By making the number equal to or greater than the lower limit, development adhesion tends to be improved. On the other hand, by making the number equal to or less than the upper limit, good development solubility can be obtained.

[0131] The number of partial structures represented by the formula (iii-1) contained in one molecule of the epoxy (meth)acrylate resin (b1-3) is not particularly limited, but is preferably 1 or more, more preferably 3 or more, even more preferably 5 or more, and is preferably 18 or less, even more preferably 15 or less. By making the number equal to or greater than the lower limit, development adhesion tends to improve. On the other hand, by making the number equal to or less than the upper limit, residual liquid tends to be reduced.

[0132] Specific examples of the epoxy (meth)acrylate resin (b1-3) are listed below.

[0133]

[0134]

[0135]

[0136] [Acrylic copolymer resin (b2)] From the viewpoint of curability, the acrylic copolymer resin (b2) preferably has an ethylenic double bond in a side chain. Among the acrylic copolymer resins (b2), from the viewpoint of development solubility, an acrylic copolymer resin (b2-1) containing a partial structure represented by the following general formula (I) is preferred.

[0137]

[0138] In formula (I), R Ａ and R Ｂ each independently represents a hydrogen atom or a methyl group. * represents a bond. From the viewpoint of developability, the partial structure represented by formula (I) is preferably a partial structure represented by the following general formula (I-1):

[0139]

[0140] In formula (I-1), R Ａ and R Ｂ has the same meaning as that in formula (I). １ has the same meaning as that of the formula (i-1) above. From the viewpoint of sensitivity, the partial structure represented by the formula (I) above is preferably a partial structure represented by the following formula (I-2):

[0141]

[0142] In formula (I-2), R Ａ and R Ｂ has the same meaning as that in formula (I) above.

[0143] When the acrylic copolymer resin (b2-1) contains a partial structure represented by the general formula (I), the content of the partial structure represented by the general formula (I) contained in the acrylic copolymer resin (b2-1) is not particularly limited, but is preferably 5 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, even more preferably 50 mol% or more, particularly preferably 70 mol% or more, most preferably 80 mol% or more, and is preferably 99 mol% or less, more preferably 97 mol% or less, and even more preferably 95 mol% or less. By making the content equal to or greater than the lower limit, good developer solubility can be obtained. On the other hand, by making the content equal to or less than the upper limit, developer adhesion tends to be improved.

[0144] When the acrylic copolymer resin (b2-1) contains a partial structure represented by the general formula (I-1), the content of the partial structure represented by the general formula (I-1) contained in the acrylic copolymer resin (b2-1) is not particularly limited, but is preferably 1 mol% or more, more preferably 5 mol% or more, even more preferably 8 mol% or more, even more preferably 10 mol% or more, and is preferably 99 mol% or less, more preferably 60 mol% or less, even more preferably 40 mol% or less, even more preferably 30 mol% or less, and particularly preferably 20 mol% or less. By making the content equal to or greater than the lower limit, sensitivity is increased and good developer solubility can be obtained. Furthermore, by making the content equal to or less than the upper limit, developer adhesion tends to be improved.

[0145] When the acrylic copolymer resin (b2-1) contains a partial structure represented by the general formula (I-2), the content of the partial structure represented by the general formula (I-2) contained in the acrylic copolymer resin (b2-1) is not particularly limited, but is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, even more preferably 40 mol% or more, particularly preferably 50 mol% or more, and most preferably 70 mol% or more, and is preferably 99 mol% or less, more preferably 95 mol% or less, even more preferably 90 mol% or less, and particularly preferably 85 mol% or less. By making the content equal to or greater than the lower limit, sensitivity tends to be increased. On the other hand, by making the content equal to or less than the upper limit, developability tends to be improved.

[0146] When the acrylic copolymer resin (b2-1) contains a partial structure represented by the general formula (I), other partial structures that may be contained therein are not particularly limited. However, from the viewpoint of development adhesion, it is preferable that the acrylic copolymer resin (b2-1) contains, for example, a partial structure represented by the following general formula (I′):

[0147]

[0148] In the above formula (I′), R Ｄ represents a hydrogen atom or a methyl group, R Ｅrepresents an alkyl group which may have a substituent, an aryl group (aromatic ring group) which may have a substituent, or an alkenyl group which may have a substituent. Ｅ represents an alkyl group which may have a substituent, an aryl group which may have a substituent, or an alkenyl group which may have a substituent. Ｅ The alkyl group in the formula (I) may be a linear, branched, or cyclic alkyl group. The number of carbon atoms is preferably 1 or more, more preferably 3 or more, and even more preferably 5 or more, and is preferably 20 or less, more preferably 18 or less, more preferably 16 or less, even more preferably 14 or less, and particularly preferably 12 or less. By making the number of carbon atoms equal to or greater than the lower limit, the film strength tends to be increased and the development adhesion tends to be improved. On the other hand, by making the number of carbon atoms equal to or less than the upper limit, good development solubility can be obtained.

[0149] Examples of the alkyl group include a methyl group, an ethyl group, a cyclohexyl group, a dicyclopentanyl group, and a dodecanyl group.Among these, from the viewpoint of film strength, a dicyclopentanyl group and a dodecanyl group are preferred, and a dicyclopentanyl group is more preferred.Examples of the substituent that the alkyl group may have include a methoxy group, an ethoxy group, a chloro group, a bromo group, a fluoro group, a hydroxy group, an amino group, an epoxy group, an oligoethylene glycol group, a phenyl group, a carboxy group, an acryloyl group, and a methacryloyl group, and from the viewpoint of developability, a hydroxy group and an oligoethylene glycol group are preferred.

[0150] R ＥExamples of the aryl group (aromatic ring group) in the above formula include a monovalent aromatic hydrocarbon ring group and a monovalent aromatic heterocyclic group. The number of carbon atoms is preferably 6 or more, and is preferably 24 or less, more preferably 22 or less, even more preferably 20 or less, and particularly preferably 18 or less. By setting the carbon number at or above the lower limit, development adhesion tends to be improved. By setting the carbon number at or below the upper limit, residue tends to be reduced. The aromatic hydrocarbon ring in the aromatic hydrocarbon ring group may be a single ring or a condensed ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring. The aromatic heterocyclic group in the aromatic heterocyclic group can be a single ring or a condensed ring, for example, can be enumerated as furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, cinnoline ring, quinoxaline ring, phenanthridine ring, perimidine ring, quinazoline ring, quinazolinone ring, azulene ring.Among these, from the viewpoint of curability, benzene ring group, naphthalene ring group are preferred, and benzene ring group is more preferred. Examples of the substituent that the aryl group may have include a methyl group, an ethyl group, a propyl group, a methoxy group, an ethoxy group, a chloro group, a bromo group, a fluoro group, a hydroxy group, an amino group, an epoxy group, an oligoethylene glycol group, a phenyl group, and a carboxy group. From the viewpoint of developability, a hydroxy group and an oligoethylene glycol group are preferred.

[0151] R ＥThe alkenyl group in the formula (I) may be a linear, branched, or cyclic alkenyl group. The number of carbon atoms is preferably 2 or more, and is preferably 22 or less, more preferably 20 or less, even more preferably 18 or less, even more preferably 16 or less, and particularly preferably 14 or less. By setting the carbon number at or above the lower limit, development adhesion tends to be improved. By setting the carbon number at or below the upper limit, good development solubility can be obtained. Examples of alkenyl groups include ethenyl, propenyl, butenyl, and cyclohexenyl groups. Among these, from the viewpoint of curability, ethenyl and propenyl groups are preferred, and ethenyl is more preferred. Examples of substituents that the alkenyl group may have include methoxy, ethoxy, chloro, bromo, fluoro, hydroxy, amino, epoxy, oligoethylene glycol, phenyl, and carboxy groups. From the viewpoint of developability, hydroxy and oligoethylene glycol groups are preferred. Among these, from the viewpoint of developability, R Ｅ As the alkyl group, an alkyl group or an alkenyl group is preferable, an alkyl group is more preferable, and a dicyclopentanyl group is even more preferable.

[0152] When the acrylic copolymer resin (b2-1) contains a partial structure represented by the general formula (I'), the content of the partial structure represented by the general formula (I') contained in the acrylic copolymer resin (b2-1) is not particularly limited, but is preferably 0.5 mol% or more, more preferably 1 mol% or more, even more preferably 1.5 mol% or more, particularly preferably 2 mol% or more, and is preferably 90 mol% or less, more preferably 70 mol% or less, even more preferably 50 mol% or less, even more preferably 30 mol% or less, and particularly preferably 10 mol% or less. By making the content equal to or greater than the lower limit, development adhesion tends to be improved. On the other hand, by making the content equal to or less than the upper limit, good development solubility can be obtained.

[0153] When the acrylic copolymer resin (b2-1) contains a partial structure represented by the general formula (I) above, it preferably further contains a partial structure represented by the following general formula (I″) from the viewpoints of heat resistance and film strength:

[0154]

[0155] In the above formula (I″), R Ｆ represents a hydrogen atom or a methyl group, R Ｇ represents an alkyl group which may have a substituent, an alkenyl group which may have a substituent, a hydroxy group, a carboxy group, a halogen atom, an alkoxy group which may have a substituent, a thiol group, or an alkylsulfide group which may have a substituent. t represents an integer of 0 to 5. R Ｇ The alkyl group in the formula (I) may be a linear, branched, or cyclic alkyl group. The number of carbon atoms is preferably 1 or more, more preferably 3 or more, and even more preferably 5 or more, and is preferably 20 or less, more preferably 18 or less, more preferably 16 or less, even more preferably 14 or less, and particularly preferably 12 or less. By making the number of carbon atoms equal to or greater than the lower limit, development adhesion tends to be improved. On the other hand, by making the number of carbon atoms equal to or less than the upper limit, good development solubility can be obtained.

[0156] R Ｇ Examples of the alkyl group in the formula (I) include a methyl group, an ethyl group, a cyclohexyl group, a dicyclopentanyl group, and a dodecanyl group. Among these, from the viewpoint of development adhesion, a dicyclopentanyl group and a dodecanyl group are preferred, and a dicyclopentanyl group is more preferred. Examples of the substituent that the alkyl group may have include a methoxy group, an ethoxy group, a chloro group, a bromo group, a fluoro group, a hydroxy group, an amino group, an epoxy group, an oligoethylene glycol group, a phenyl group, a carboxy group, an acryloyl group, and a methacryloyl group, and from the viewpoint of development property, a hydroxy group and an oligoethylene glycol group are preferred.

[0157] R ＧExamples of the alkenyl group in the formula (I) include linear, branched, and cyclic alkenyl groups. The number of carbon atoms is preferably 2 or more, and is preferably 22 or less, more preferably 20 or less, even more preferably 18 or less, even more preferably 16 or less, and particularly preferably 14 or less. By setting the carbon number at or above the lower limit, development adhesion tends to be improved. On the other hand, by setting the carbon number at or below the upper limit, good development solubility can be obtained. Examples of alkenyl groups include ethenyl, propenyl, butenyl, and cyclohexenyl groups. Among these, from the viewpoint of curability, ethenyl and propenyl groups are preferred, and ethenyl is more preferred. Examples of substituents that the alkenyl group may have include methoxy, ethoxy, chloro, bromo, fluoro, hydroxy, amino, epoxy, oligoethylene glycol, phenyl, and carboxy groups. From the viewpoint of developability, hydroxy and oligoethylene glycol groups are preferred. Ｇ Examples of the halogen atom in the compound include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom is preferred from the viewpoint of liquid repellency (ink repellency).

[0158] R Ｇ The alkoxy group in the formula (I) may be a linear, branched, or cyclic alkoxy group. The number of carbon atoms is preferably 1 or more, and is preferably 20 or less, more preferably 18 or less, even more preferably 16 or less, even more preferably 14 or less, and particularly preferably 12 or less. By setting the carbon number at or above the lower limit, the development adhesion tends to be improved. By setting the carbon number at or below the upper limit, the residual liquid tends to be reduced. Examples of substituents that the alkoxy group may have include a methoxy group, an ethoxy group, a chloro group, a bromo group, a fluoro group, a hydroxy group, an amino group, an epoxy group, an oligoethylene glycol group, a phenyl group, a carboxy group, an acryloyl group, and a methacryloyl group. From the viewpoint of developability, a hydroxy group and an oligoethylene glycol group are preferred.

[0159] R ＧExamples of the alkyl sulfide group in the formula (I) include linear, branched, and cyclic alkyl sulfide groups. The number of carbon atoms is preferably 1 or more, and is preferably 20 or less, more preferably 18 or less, even more preferably 16 or less, even more preferably 14 or less, and particularly preferably 12 or less. By setting the carbon number at or above the lower limit, development adhesion tends to be improved. By setting the carbon number at or below the upper limit, residue tends to be reduced. Examples of alkyl sulfide groups include methyl sulfide, ethyl sulfide, propyl sulfide, and butyl sulfide groups. Among these, methyl sulfide and ethyl sulfide groups are preferred from the viewpoint of developability. Examples of substituents that the alkyl group in the alkyl sulfide group may have include methoxy, ethoxy, chloro, bromo, fluoro, hydroxy, amino, epoxy, oligoethylene glycol, phenyl, carboxy, acryloyl, and methacryloyl groups. From the viewpoint of developability, hydroxy, oligoethylene glycol, and carboxy are preferred. In the formula (I″), t represents an integer of 0 to 5. From the viewpoint of developability, t is preferably an integer of 0 to 2, more preferably 0 to 1, and even more preferably 0.

[0160] When the acrylic copolymer resin (b2-1) contains a partial structure represented by the general formula (I"), the content of the partial structure represented by the general formula (I") contained in the acrylic copolymer resin (b2-1) is not particularly limited, but is preferably 1 mol% or more, more preferably 2 mol% or more, even more preferably 3 mol% or more, particularly preferably 5 mol% or more, and is preferably 90 mol% or less, more preferably 70 mol% or less, more preferably 50 mol% or less, even more preferably 30 mol% or less, particularly preferably 20 mol% or less, and most preferably 10 mol% or less. By making the content equal to or greater than the lower limit, development adhesion tends to be improved. On the other hand, by making the content equal to or less than the upper limit, residue tends to be reduced.

[0161] When the acrylic copolymer resin (b2-1) contains a partial structure represented by the general formula (I) above, it preferably further contains a partial structure represented by the following general formula (I''') from the viewpoint of developability.

[0162]

[0163] In the above formula (I''', R Ｈ represents a hydrogen atom or a methyl group.

[0164] When the acrylic copolymer resin (b2-1) contains a partial structure represented by the general formula (I'"), the content of the partial structure represented by the general formula (I'") contained in the acrylic copolymer resin (b2-1) is not particularly limited, but is preferably 5 mol % or more, more preferably 10 mol % or more, even more preferably 30 mol % or more, and is preferably 90 mol % or less, more preferably 80 mol % or less, even more preferably 70 mol % or less, and particularly preferably 50 mol % or less. By making the content equal to or greater than the lower limit, good developer solubility can be obtained. On the other hand, by making the content equal to or less than the upper limit, developer adhesion tends to be improved.

[0165] The acid value of the acrylic copolymer resin (b2) is not particularly limited, but is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 20 mgKOH / g or more, and even more preferably 25 mgKOH / g or more, and is preferably 100 mgKOH / g or less, more preferably 80 mgKOH / g or less, even more preferably 60 mgKOH / g or less, and even more preferably 40 mgKOH / g or less. By setting the acid value at or above the lower limit, good developer solubility can be obtained. On the other hand, by setting the acid value at or below the upper limit, developer adhesion tends to be improved.

[0166] The weight average molecular weight (Mw) of the acrylic copolymer resin (b2) is not particularly limited, but is preferably 1000 or more, more preferably 2000 or more, even more preferably 3000 or more, still more preferably 4000 or more, and particularly preferably 5000 or more, and is preferably 30000 or less, more preferably 20000 or less, even more preferably 15000 or less, and still more preferably 10000 or less. Particularly preferably 8000 or less. By making it equal to or greater than the lower limit, development adhesion tends to be improved. On the other hand, by making it equal to or less than the upper limit, good development solubility can be obtained.

[0167] When the alkali-soluble resin (B) contains an acrylic copolymer resin (b2), the content of the acrylic copolymer resin (b2) contained in the alkali-soluble resin (B) is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more, and is usually preferably 100% by mass or less, more preferably 80% by mass or less, and even more preferably 50% by mass or less. By setting it to the lower limit or more, the developer solubility tends to be good. By setting it to the upper limit or less, the taper angle tends to be high.

[0168] The alkali-soluble resin (B) may contain either the epoxy (meth)acrylate resin (b1) or the acrylic copolymer resin (b2) alone or both. Furthermore, the alkali-soluble resin (B) may contain an alkali-soluble resin other than the alkali-soluble resin (b).

[0169] The content of the alkali-soluble resin (B) in the photosensitive resin composition of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, still more preferably 30% by mass or more, particularly preferably 40% by mass or more, and preferably 90% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass or less, particularly preferably 50% by mass or less, based on the total solid content of the photosensitive resin composition. By making the content equal to or greater than the lower limit, developability tends to be improved. On the other hand, by making the content equal to or less than the upper limit, good developability can be obtained.

[0170] When the photosensitive resin composition of the present invention contains an epoxy (meth)acrylate resin (b1), the content of the epoxy (meth)acrylate resin (b1) is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, even more preferably 30% by mass or more, particularly preferably 40% by mass or more, and preferably 90% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass or less, particularly preferably 50% by mass or less, based on the total solid content of the photosensitive resin composition. By making the content equal to or greater than the lower limit, developability tends to be improved. Furthermore, by making the content equal to or less than the upper limit, good developability can be obtained.

[0171] Furthermore, when the photosensitive resin composition of the present invention contains an acrylic copolymer resin (b2), the content of the acrylic copolymer resin (b2) is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, even more preferably 30% by mass or more, particularly preferably 40% by mass or more, and preferably 90% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass or less, particularly preferably 50% by mass or less, based on the total solid content of the photosensitive resin composition. By making the content equal to or greater than the lower limit, developability tends to be improved. By making the content equal to or less than the upper limit, good developer solubility can be obtained.

[0172] Furthermore, the total content of the alkali-soluble resin (B) and the photopolymerizable compound (C) in the total solid content of the photosensitive resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 30% by mass or more, even more preferably 50% by mass or more, particularly preferably 70% by mass or more, even more particularly preferably 80% by mass or more, and most preferably 90% by mass or more, and is preferably 99% by mass or less, more preferably 97% by mass or less, and even more preferably 95% by mass or less. By setting it to be equal to or greater than the lower limit, curability tends to be improved. By setting it to be equal to or less than the upper limit, good development solubility can be obtained.

[0173] The compounding ratio of the alkali-soluble resin (B) to the photopolymerizable compound (C) in the photosensitive resin composition is preferably 50 parts by mass or more, more preferably 60 parts by mass or more, even more preferably 70 parts by mass or more, and particularly preferably 80 parts by mass or more, per 100 parts by mass of the photopolymerizable compound (C), and is preferably 400 parts by mass or less, more preferably 300 parts by mass or less, even more preferably 200 parts by mass or less, and particularly preferably 120 parts by mass or less. By setting the ratio at or above the lower limit, development adhesion tends to be improved. On the other hand, by setting the ratio at or below the upper limit, curability tends to be improved.

[0174] The photosensitive resin composition of the present invention may contain a phosphoric acid-based adhesion improver to improve adhesion to a substrate. As the phosphoric acid-based adhesion improver, (meth)acryloyloxy group-containing phosphates are preferred, and among them, those represented by the following general formulas (Va), (Vb), and (Vc) are preferred.

[0175]

[0176] In the above general formulae (Va), (Vb), and (Vc), R 8 represents a hydrogen atom or a methyl group, r and r' are integers of 1 to 10, and s is a real number of 1 to 3.

[0177] When the photosensitive resin composition of the present invention contains a phosphoric acid-based adhesion improver, its content is not particularly limited, but is preferably 0.1 mass% or more, more preferably 0.2 mass% or more, even more preferably 0.3 mass% or more, and is preferably 5 mass% or less, more preferably 3 mass% or less, and even more preferably 1 mass% or less, based on the total solid content of the photosensitive resin composition. The upper and lower limits can be arbitrarily combined, and for example, 0.1 to 5 mass% is preferred, 0.2 to 3 mass% is more preferred, and 0.3 to 1 mass% is even more preferred. By setting the content at or above the lower limit, adhesion to the substrate tends to be improved. Furthermore, by setting the content at or below the upper limit, surface curability tends to be improved.

[0178] (C) Photopolymerizable Compound The photosensitive resin composition of the present invention contains (C) a photopolymerizable compound. It is believed that the inclusion of (C) a photopolymerizable compound results in high sensitivity. The photopolymerizable compound used herein refers to a compound having one or more ethylenically unsaturated bonds (ethylenic double bonds) in the molecule, but from the viewpoints of polymerizability, crosslinkability, and the associated ability to increase the difference in developer solubility between exposed and unexposed areas, a compound having two or more ethylenically unsaturated bonds in the molecule is preferred. Furthermore, it is more preferred that the unsaturated bond is derived from a (meth)acryloyloxy group, i.e., a (meth)acrylate compound.

[0179] In the photosensitive resin composition of the present invention, it is particularly desirable to use a polyfunctional ethylenic monomer having two or more ethylenically unsaturated bonds per molecule. The number of ethylenically unsaturated groups in the polyfunctional ethylenic monomer is not particularly limited, but is preferably two or more, more preferably three or more, even more preferably four or more, and particularly preferably five or more, and is preferably 15 or less, more preferably 10 or less, even more preferably eight or less, and particularly preferably seven or less. Setting the number at or above the lower limit tends to improve polymerization properties and result in high sensitivity. Setting the number at or below the upper limit tends to result in better developability. Examples of (C) photopolymerizable compounds include esters of aliphatic polyhydroxy compounds and unsaturated carboxylic acids; esters of aromatic polyhydroxy compounds and unsaturated carboxylic acids; and esters obtained by esterification of polyvalent hydroxy compounds, such as aliphatic polyhydroxy compounds and aromatic polyhydroxy compounds, with unsaturated carboxylic acids and polybasic carboxylic acids.

[0180] Examples of esters of aliphatic polyhydroxy compounds and unsaturated carboxylic acids include acrylic acid esters of aliphatic polyhydroxy compounds such as ethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and glycerol acrylate; methacrylic acid esters in which the acrylate of these compounds is replaced with methacrylate; itaconic acid esters in which the acrylate of these compounds is replaced with itaconate; crotonate esters in which the acrylate of these compounds is replaced with crotonate; and maleic acid esters in which the acrylate of these compounds is replaced with maleate.

[0181] Examples of esters of aromatic polyhydroxy compounds and unsaturated carboxylic acids include acrylic acid esters and methacrylic acid esters of aromatic polyhydroxy compounds such as hydroquinone diacrylate, hydroquinone dimethacrylate, resorcinol diacrylate, resorcinol dimethacrylate, pyrogallol triacrylate, etc. Esters obtained by the esterification reaction of polyhydric hydroxy compounds such as aliphatic polyhydroxy compounds and aromatic polyhydroxy compounds with unsaturated carboxylic acids and polybasic carboxylic acids are not necessarily single compounds, but include, for example, condensates of acrylic acid, phthalic acid, and ethylene glycol; condensates of acrylic acid, maleic acid, and diethylene glycol; condensates of methacrylic acid, terephthalic acid, and pentaerythritol; and condensates of acrylic acid, adipic acid, butanediol, and glycerin.

[0182] Other useful examples of the photopolymerizable compound (C) used in the photosensitive resin composition of the present invention include urethane (meth)acrylates such as those obtained by reacting a polyisocyanate compound with a hydroxyl group-containing (meth)acrylic acid ester or a polyisocyanate compound with a polyol and a hydroxyl group-containing (meth)acrylic acid ester; epoxy acrylates such as addition reaction products of a polyfunctional epoxy compound with a hydroxyl group-containing (meth)acrylic acid ester or (meth)acrylic acid; acrylamides such as ethylenebisacrylamide; allyl esters such as diallyl phthalate; and vinyl group-containing compounds such as divinyl phthalate. Examples of urethane (meth)acrylates include DPHA-40H, UX-5000, UX-5002D-P20, UX-5003D, and UX-5005 (manufactured by Nippon Kayaku Co., Ltd.), U-2PPA, U-6LPA, U-10PA, U-33H, UA-53H, UA-32P, and UA-11OOH (manufactured by Shin-Nakamura Chemical Co., Ltd.), UA-306H, UA-510H, and UF-8001G (manufactured by Kyoeisha Chemical Co., Ltd.), and UV-1700B, UV-7600B, UV-7605B, UV-7630B, and UV7640B (manufactured by Mitsubishi Chemical Corporation).

[0183] Among these, from the viewpoint of an appropriate taper angle and sensitivity, it is preferable to use ester (meth)acrylates or urethane (meth)acrylates as the photopolymerizable compound (C), and it is more preferable to use dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, 2-tris(meth)acryloyloxymethylethyl phthalate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol di(meth)acrylate, a dibasic acid anhydride adduct of dipentaerythritol penta(meth)acrylate, or a dibasic acid anhydride adduct of pentaerythritol tri(meth)acrylate. These may be used alone or in combination of two or more.

[0184] In the photosensitive resin composition of the present invention, the molecular weight of the photopolymerizable compound (C) is not particularly limited, but from the viewpoints of sensitivity, liquid repellency (ink repellency), and taper angle, it is preferably 100 or more, more preferably 150 or more, even more preferably 200 or more, still more preferably 300 or more, particularly preferably 400 or more, and most preferably 500 or more, and is preferably 1000 or less, more preferably 700 or less. The number of carbon atoms in the photopolymerizable compound (C) is not particularly limited, but from the viewpoints of sensitivity, liquid repellency (ink repellency), and taper angle, it is preferably 7 or more, more preferably 10 or more, even more preferably 15 or more, still more preferably 20 or more, particularly preferably 25 or more, and preferably 50 or less, more preferably 40 or less, even more preferably 35 or less, and particularly preferably 30 or less. From the viewpoints of sensitivity, liquid repellency (ink repellency), and taper angle, ester (meth)acrylates, epoxy (meth)acrylates, and urethane (meth)acrylates are preferred, and among these, tri- or higher functional ester (meth)acrylates such as pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate dipentaerythritol hexa(meth)acrylate, and dipentaerythritol penta(meth)acrylate, and adducts of acid anhydrides to tri- or higher functional ester (meth)acrylates such as 2,2,2-tris(meth)acryloyloxymethylethyl phthalate and dibasic acid anhydride adducts of dipentaerythritol penta(meth)acrylate are more preferred.

[0185] The content of the photopolymerizable compound (C) in the photosensitive resin composition of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, even more preferably 30% by mass or more, particularly preferably 40% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass or less, even more preferably 55% by mass or less, particularly preferably 50% by mass or less, based on the total solid content of the photosensitive resin composition. By making it equal to or greater than the lower limit, appropriate internal curing properties tend to be obtained. By making it equal to or less than the upper limit, developability tends to be good.

[0186] (D) Liquid-repellent Agent The liquid-repellent agent preferably contains an acrylic resin containing a repeating unit represented by the following general formula (II) and a fluorine atom (hereinafter also referred to as acrylic resin (D1)).

[0187]

[0188] (In formula (II), R １１ each independently represents a hydrogen atom or a methyl group, R １２ represents an alkylene group having 2 to 6 carbon atoms which may have a substituent, and may be interrupted by one or more of -O-, -C(=O)-, -S-, and -NH-. * represents a bond.

[0189] R １２ The number of carbon atoms in the alkylene group of R is usually 2 or more, preferably 4 or more, and usually 6 or less, preferably 5 or less. By making it equal to or more than the lower limit, synthesis becomes easy. On the other hand, by making it equal to or less than the upper limit, the degree of freedom of the ethylenically unsaturated bond increases, and curability and liquid repellency tend to improve. In addition, １２ The alkylene group in may be interrupted by one or more of -O-, -C(=O)-, -S-, and -NH-. In another embodiment, it may be interrupted by -O-, -C(=O)-, or -NH-, and in yet another embodiment, it may be interrupted by -O-C(=O)-NH-. １２ When has a substituent, examples of the substituent include a hydroxyl group and an alkoxy group having 1 to 3 carbon atoms. It is preferably unsubstituted or substituted with a hydroxyl group, and more preferably unsubstituted.

[0190] R １２ As for -(C ２ H ４ ) ２ -NHCOO-(C ２ H ４ ) ２ -, -(CH) ２ -CHOH-(CH ２ A group represented by -(C)- is preferred in terms of liquid repellency. ２ H ４ ) ２ -NHCOO-(C ２ H４ ) ２ A group represented by - is more preferred. Since the inclusion of the acrylic resin (D1) can impart liquid repellency to the surface of the resulting uneven structure, when a liquid conductive material is applied by an inkjet method or the like to form a conductive portion, adhesion of the conductive material to the convex surface is prevented, and mixing of the conductive materials injected into adjacent concave portions can be prevented. By using a liquid repellent agent having an ethylenically unsaturated group such as that represented by general formula (II), the crosslinking reaction on the surface can be accelerated when the formed coating film of the photosensitive resin composition is exposed to light, making it less likely for the liquid repellent agent to flow out during development. As a result, it is believed that the resulting convex surface can exhibit high liquid repellency. Furthermore, by using a resin containing fluorine atoms, the acrylic resin (D1) segregates on the convex surface, making the concave portions relatively more lyophilic, and the conductive material easily penetrates and spreads selectively into the concave portions. As a result, breakdown of the conductive material from within the concave portions to the convex surface can be prevented, allowing for the formation of highly precise conductive portion patterns. Furthermore, even when different conductive materials are placed in adjacent concave portions, mixing of different conductive materials can be prevented. More specifically, the group having a fluorine atom repels the conductive material and prevents the conductive material from crossing the convex portions of the concave-convex structure and entering adjacent regions, resulting in mixing of the conductive materials.

[0191] In the metasurface structure of the present invention, the contact angle, which is an index of liquid repellency, is preferably 20° or more on the upper surface of the convex portion. As described above, a contact angle of 20° or more allows the conductive material to be efficiently filled into the concave portions of the concave-convex structure. From the above perspective, the contact angle on the upper surface of the convex portion of the metasurface structure is more preferably 30° or more, and even more preferably 40° or more. The contact angle is a value measured using the method described in the examples.

[0192] In the metasurface structure of the present invention, the contact angle of the wall surfaces of the convex portions is preferably smaller than the contact angle of the upper surfaces of the convex portions, from the viewpoint of uniformly filling the entire recesses of the concave-convex structure with the conductive material. By making the contact angle of the wall surfaces of the convex portions smaller than the contact angle of the upper surfaces of the convex portions, the conductive material can be more easily transferred from the upper surfaces of the convex portions to the recesses, thereby enabling the recesses to be uniformly filled. The contact angle of the wall surfaces of the convex portions is preferably less than 20°, and more preferably 10° or less. The contact angle value is a value measured by the method described in the examples.

[0193] The acrylic resin (D1) preferably has either or both of a fluoroalkyl group and a fluoroalkylene group, more preferably either or both of a perfluoroalkyl group and a perfluoroalkylene ether chain. By having either or both of a fluoroalkyl group and a fluoroalkylene group, or either or both of a perfluoroalkyl group and a perfluoroalkylene ether chain, the fluorine atom-containing resin is more likely to segregate on the surface of the convex parts of the uneven structure, exhibiting higher liquid repellency and tending to promote the penetration of the conductive material into the concave parts.

[0194] Examples of the perfluoroalkyl group include a perfluorobutyl group, a perfluorohexyl group, and a perfluorooctyl group. Examples of the perfluoroalkylene ether chain include -CF ２ -O-, -(CF ２ ) ２ -O-, -(CF ２ ) ３ —O—, —CF ２ -CF (CF ３ ) -O-, -CF(CF ３ )-CF ２ Examples thereof include —O— and divalent groups having these repeating units.

[0195] The acrylic resin (D1) may have a structural unit other than the repeating unit represented by general formula (II) or the structural unit containing a fluorine atom. Examples of such a structural unit include a structural unit containing an epoxy group, a structural unit containing a carboxy group, and a structural unit having an alkylene oxide chain. As a commercially available acrylic resin (D1), a fluorine-containing organic compound available under the trade name "Megafac (registered trademark; the same applies hereinafter) RS-72-K" or "Megafac RS-90" manufactured by DIC Corporation can be used.

[0196] The fluorine atom content in the acrylic resin (D1) is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and even more preferably 25% by mass or more in the acrylic resin (D1). Also, it is preferably 50% by mass or less, more preferably 35% by mass or less. By making it equal to or greater than the lower limit, a high contact angle can be easily ensured, and by making it equal to or less than the upper limit, outflow to the conductive part can be suppressed.

[0197] The molecular weight of the acrylic resin (D1) is not particularly limited, and may be a low molecular weight compound or a high molecular weight compound. High molecular weight compounds are preferred because they suppress fluidity due to post-baking and can prevent outflow from the uneven structure. From this viewpoint, the weight average molecular weight of the acrylic resin (D1) is preferably 100 or more, more preferably 500 or more, and preferably 100,000 or less, more preferably 10,000 or less. The acrylic resin (D1) may be used alone or in combination of two or more. In addition, in the present invention, a liquid repellent other than the acrylic resin (D1) may be used in combination as the liquid repellent (D).

[0198] The liquid repellent agent also preferably contains a compound (D2) having a siloxane chain. Specifically, the siloxane chain of the compound (D2) is preferably a polysiloxane represented by the following structural formula: R １ R ２ R ３ Si—O—(SiR ４ R ５ —O)n-SiR ６ R ７ R ８ Here, R １ , R２ , R ３ , R ４ , R ５ , R ６ , R ７ , R ８ each independently represents a monovalent organic group or a hydrogen atom.

[0199] The monovalent organic group is preferably a hydrocarbon group having 1 to 10 carbon atoms, and specific examples thereof include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl; alkenyl groups such as vinyl, allyl, butenyl, pentenyl, and hexenyl; aryl groups such as phenyl, tolyl, and xylyl; aralkyl groups such as benzyl and phenethyl; and substituted alkyl groups such as chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, and nonafluorobutylethyl. These organic groups may have an ester bond. n is an integer of 0 or greater, preferably 5 or greater, more preferably 10 or greater, and 2000 or less, preferably 1500 or less, more preferably 1000 or less, even more preferably 500 or less, and particularly preferably 300 or less. Setting the n at or above the lower limit tends to improve liquid repellency (ink repellency). Setting the n at or below the upper limit tends to improve the uniformity of the coating film.

[0200] Examples of commercially available products of the compound (D2) containing a siloxane chain include compounds sold under the trade names "BYK-UV3500 series" manufactured by BYK-Chemie, "8SS" series manufactured by Taisei Fine Chemical Co., Ltd., and "KP series" manufactured by Shin-Etsu Chemical Co., Ltd.

[0201] The content of the liquid repellent agent (D) in the photosensitive resin composition of the present invention is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and particularly preferably 0.2% by mass or more, based on the total solid content of the photosensitive resin composition, and is also preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less. By making the content equal to or greater than the lower limit, the liquid repellency (ink repellency) tends to be improved. Furthermore, by making the content equal to or less than the upper limit, a uniform coating film tends to be obtained more easily when applying ink to pixel portions after forming the uneven structure.

[0202] When the photosensitive resin composition of the present invention contains an acrylic resin (D1), the content of the acrylic resin (D1) in the photosensitive resin composition of the present invention is not particularly limited, but is preferably 0.01 mass% or more, more preferably 0.11 mass% or more, even more preferably 0.2 mass% or more, and is preferably 5 mass% or less, more preferably 3 mass% or less, and even more preferably 1 mass% or less, based on the total solid content of the photosensitive resin composition. By making the content equal to or greater than the lower limit, the liquid repellency tends to be improved. Furthermore, by making the content equal to or less than the upper limit, a uniform coating film tends to be obtained more easily when a conductive material is applied after the formation of the uneven structure.

[0203] <Conductive Portion> As shown in FIG. 1, the metasurface structure of the present invention includes a conductive portion 12. The conductive portion is formed by filling at least a portion of the recesses of the concave-convex structure with a conductive material. The conductive material is applied by printing, such as an inkjet method. During this process, the convex portions of the concave-convex structure are liquid-repellent, allowing the conductive material to effectively fill the desired recesses. This prevents the conductive material from flowing beyond the convex portions into other regions, enabling finer and more precise conductive patterns. This is advantageous for forming metasurfaces targeted at high-frequency radio waves used in next-generation communications. Furthermore, because mixing with the conductive material in other regions is prevented, this method is particularly advantageous when different conductive materials are used in different regions. As shown in FIG. 1, the conductive portion 12 is formed by a single shape or a plurality of shapes periodically arranged, allowing for the formation of desired patterns useful for metasurface structures.

[0204] The height of the conductive portion is not particularly limited as long as it is within a range that achieves the effects of the present invention, but is preferably 5 nm or more and 10 μm or less. If the height of the conductive portion is 5 nm or more, the function of the metasurface structure can be fully exhibited. Furthermore, if the height of the conductive portion is 10 μm or less, sufficient surface smoothness for the metasurface structure can be obtained. From the above perspectives, the height of the conductive portion is more preferably 10 nm or more, and even more preferably 100 nm or more. On the other hand, the upper limit is more preferably 5 μm or less, and even more preferably 1 μm or less. Note that when the conductive portion has a concave meniscus shape as shown in FIG. 1, the height of the conductive portion is defined as the height from the substrate to the bottom surface of the concave meniscus if no resin layer or primer layer is provided in the recess, and is defined as the height from the substrate to the top surface of the conductive portion if the conductive portion is smooth. Furthermore, when a resin layer or a primer layer, or both, are provided in the recess, if the conductive portion has a concave meniscus shape, the height of the conductive portion is defined as the height from the surface of the resin layer or primer layer formed on the bottom surface of the recess to the lower surface of the concave meniscus. If the conductive portion is smooth, the height is defined as the height from the surface of the resin layer or primer layer formed on the bottom surface of the recess to the upper surface of the conductive portion. Furthermore, since the conductive portion is formed in a recess with a concave-convex structure, the height ratio of the conductive portion to the convex portion is also important. The ratio of the height of the conductive portion to the height of the convex portion (height of the conductive portion / height of the convex portion) is preferably 0.01 or more and 1 or less. If this ratio is 0.01 or more, the conductive portion is sufficiently thick and can fully function as a metasurface. On the other hand, if this ratio is 1 or less, the conductive material is embedded in the concave portion of the concave-convex structure and does not leak into other regions. In particular, in the metasurface structure of the present invention, the convex portion surfaces are liquid-repellent, so even if the ratio is 1, the leakage of the conductive material into other regions is suppressed. From the above viewpoints, the ratio is more preferably in the range of 0.05 to 0.9, and even more preferably in the range of 0.1 to 0.8.

[0205] Furthermore, the line width of the conductive portion is preferably 1 μm or more and 1 mm or less. If the line width is 1 μm or more, a uniform, high-definition pattern can be formed without the conductive material flowing into areas other than the recesses. On the other hand, if the line width is 1 mm or less, a fine conductive pattern can be obtained, and the metasurface structure can fully function. From the above perspectives, the line width of the conductive portion is more preferably 3 μm or more, and even more preferably 5 μm or more. On the other hand, the upper limit is more preferably 500 μm or less, and even more preferably 100 μm or less. Note that the line width of the conductive portion in the present invention is defined as the width of the conductive portion 12 formed between two adjacent convex portions, as shown in FIG. 1, and as the shortest length thereof.

[0206] The conductivity of the conductive portion is preferably 100 S / m or more. If the conductivity is 100 S / m or more, the metasurface structure can fully function. From the above viewpoint, the conductivity of the conductive portion is 1×10 ３ S / m or more is more preferable, and 1×10 ４ The higher the conductivity, the better. Therefore, there is no particular upper limit, but it is usually 1×10 ７ The conductivity is about S / m. The conductivity is measured by the method described in the examples.

[0207] The conductive material for forming the conductive portion is not particularly limited as long as it is a conductive material. Specifically, metals such as gold, platinum, silver, silver chloride, copper, titanium, palladium, aluminum, nickel, chromium, or cobalt, or alloys thereof, conductive polymers such as PEDOT / PSS, or carbon can be used. When transparency is required, ITO (indium tin oxide) may also be used. Other conductive metal oxides such as nickel oxide, tin oxide, indium oxide, indium-zirconium oxide (IZO), titanium oxide, or zinc oxide may also be used. In the present invention, metal nanoparticles are preferably used as the conductive material for forming the conductive portion. The use of metal nanoparticles allows for the use of inkjet printing, resulting in high productivity. The metal nanoparticles are filled into the recesses of the uneven structure by inkjet printing, forming conductive portions consisting of aggregates of metal nanoparticles and exhibiting conductivity. The particle size of the metal nanoparticles is preferably in the range of 1 to 100 nm. Within this range, it is easy to form aggregates of metal nanoparticles. From the above viewpoints, the particle size of the metal nanoparticles is more preferably in the range of 2 to 50 nm, and even more preferably in the range of 3 to 20 nm. The particle size of the metal nanoparticles is measured by observation with a transmission electron microscope.

[0208] The shape of the nanoparticles is not particularly limited as long as they can form a conductive portion, but they are usually spherical, and may also be disk-shaped, rod-shaped, ring-shaped, wire-shaped, etc., and these may be used alone or in combination of two or more types.

[0209] <Substrate> The metasurface structure of the present invention includes a substrate, and a resin portion having a concavo-convex structure is formed on the substrate. There are no particular limitations on the substrate as long as it is capable of forming a resin portion and a conductive portion. However, a glass substrate or a resin substrate is preferred for ease of handling and for increasing the production efficiency of the metasurface structure of the present invention. The thickness of the substrate is preferably in the range of 0.001 to 100 mm, and more preferably in the range of 0.01 to 10 mm. In addition, the surface of the substrate may be surface-treated to improve the wettability of the coating liquid and to increase adhesion to the resin portion and conductive portion, and a primer layer may be formed between the substrate and the resin portion.

[0210] [Method for manufacturing a metasurface structure] The method for manufacturing a metasurface structure of the present invention comprises the following steps (1) to (3): (1) a coating step of coating a substrate with a photosensitive resin composition containing (A) a photopolymerization initiator, (B) an alkali-soluble resin, (C) a photopolymerizable compound, and (D) a liquid-repellent agent; (2) a resin part formation step of exposing the substrate obtained in the coating step and then developing it to form a resin part having a concave-convex structure; and (3) a conductive part formation step of coating a composition containing a conductive material into the concave-convex structure obtained in the resin part formation step.

[0211] Step (1) is a step of applying a photosensitive resin composition containing (A) a photopolymerization initiator, (B) an alkali-soluble resin, (C) a photopolymerizable compound, and (D) a liquid-repellent agent to a substrate. The components of the photosensitive resin composition are as described above. Here, the liquid-repellent agent (D) in the photosensitive resin composition floats to the top after application, and when convex portions are formed in a later step, a high concentration of the liquid-repellent agent is generated near the tip of the convex portion. In particular, since a large amount of the liquid-repellent agent is present on the surface of the convex portion, the conductive material is efficiently filled into the concave portion in the later step (3). Furthermore, the presence of a large amount of the liquid-repellent agent on the surface of the convex portion can make the contact angle of the wall surface of the convex portion smaller than the contact angle of the upper surface of the convex portion. Examples of methods for applying the photosensitive resin composition to a substrate include methods using contact transfer coating devices such as roll coaters, reverse coaters, and bar coaters, and non-contact coating devices such as spinners (rotary coating devices) and curtain flow coaters. After the photosensitive resin composition is applied, the solvent is removed by drying, if necessary, to form a photosensitive resin composition layer.

[0212] Step (2) is a step of forming a resin portion by forming a concave-convex structure by photolithography. In the present invention, a photomask is used to irradiate the convex portions of the concave-convex structure with light to harden (expose), and the concave portions are removed (develop). An example of a method of forming a resin portion by forming a concave-convex structure by photolithography is shown below. First, a photomask is used to irradiate the photosensitive resin composition layer with active energy rays such as ultraviolet light or excimer laser light, thereby partially exposing the photosensitive resin composition layer according to the pattern of the concave-convex structure. For exposure, a light source that emits ultraviolet light such as a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, or a carbon arc lamp can be used. The exposure dose varies depending on the composition of the photosensitive resin composition, but is, for example, 10 to 400 mJ / cm. ２The photosensitive resin composition layer is preferably exposed to a light source at a temperature of about 1000°C. The exposed photosensitive resin composition layer is then developed with a developer to form a concave-convex pattern. The development method is not particularly limited, and immersion or spraying can be used. Specific examples of developers include organic developers such as dimethylbenzylamine, monoethanolamine, diethanolamine, and triethanolamine, as well as aqueous solutions of sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, and quaternary ammonium salts. A defoaming agent or surfactant can also be added to the developer. The developed concave-convex pattern may be exposed to light again. The developed concave-convex pattern is then post-baked and heat-cured to obtain the concave-convex structure. The post-baking is preferably performed at 150 to 250°C for 15 to 60 minutes. After the formation of the concave-convex structure, a cleaning process can be performed to clean the unexposed areas. The cleaning method is not particularly limited, and examples include plasma irradiation, excimer light irradiation, and UV irradiation.

[0213] Step (3) is a step of applying a composition containing a conductive material to the recesses. There are various application methods, but in the present invention, since it is important to selectively fill the recesses with the conductive material, an inkjet method in which application is performed using an inkjet printer is preferred. During inkjet printing, the effect of the liquid repellent present in the protrusions allows selective application to the desired recesses. Furthermore, the composition containing the conductive material can be applied to the recesses using a screen for screen printing, a bar coater, a spin coater, an air knife, or a press substrate. Even with these methods, the effect of the liquid repellent present in the protrusions allows selective application to the desired recesses.

[0214] In step (3), it is preferable to heat and dry the composition containing the conductive material at 100°C or higher within 40 minutes after application. This early heating and drying suppresses the flow of the conductive material, resulting in the formation of a conductive portion with high electrical conductivity. Furthermore, in step (3), it is preferable that the composition containing the conductive material contains a solvent with a boiling point of 180°C or higher. By containing a solvent with a boiling point of 180°C or higher, solidification of the conductive material due to evaporation of the coating liquid is prevented, and even if the coating liquid lands on the surface of the convex portion, the liquid is repelled and can enter the concave portion.

[0215] The composition containing the conductive material may contain, in addition to the conductive material, a solvent, a thickener, a dispersant, a binder, and the like, as necessary.

[0216] The present invention will be described below with reference to specific examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded. The components of the photosensitive resin composition used in the following examples and comparative examples are as follows.

[0217] [Materials Used] The materials used in the examples and comparative examples are as follows.

[0218] <Photopolymerization initiator> A compound having the following chemical structure was used as the photopolymerization initiator.

[0219]

[0220] <Alkali-Soluble Resin> A compound having the following structural units (acid value of solid content: 30 mg KOH / g, weight average molecular weight (Mw) measured by GPC in terms of polystyrene: 8000, a:b:c:d=5:2:83:10, double bond equivalent: 260 g / mol) was used as the alkali-soluble resin.

[0221]

[0222] <Photopolymerizable Compound> A mixture of pentaerythritol diacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate (mixing mass ratio of pentaerythritol diacrylate:pentaerythritol triacrylate:pentaerythritol tetraacrylate=5:65:30) was used as the photopolymerizable compound.

[0223] <Liquid repellent agent 1a> An acrylic copolymer resin (weight average molecular weight (Mw) of 90,000, content of fluorine atoms in the resin of 20% by mass) having a structural unit having a perfluoroalkyl group, a structural unit having an ethylenic double bond side chain, and a structural unit having a carboxy group was used as liquid repellent agent 1a.

[0224] <Liquid Repellent Agent 1b> A silicone compound (BYK-3570 manufactured by BYK-Chemie) was used as the liquid repellent agent 1b.

[0225] <Additives> KAYAMER PM-21 manufactured by Nippon Kayaku Co., Ltd. was used as an adhesion improver.

[0226] [Examples 1 to 10 and Comparative Examples 1 to 6] <Preparation of Photosensitive Resin Compositions> The photosensitive resin compositions of Examples 1 to 10 and Comparative Examples 1, 2, and 4 were prepared by using the components in the blending ratios shown in Table 1, and stirring the components until homogeneous using propylene glycol monomethyl ether acetate so that the content of the total solids of the photosensitive resin composition was 10% by mass in Examples 1, 5 to 10 and Comparative Examples 1, 2, and 4, and 6% by mass in Examples 2 to 4. The blending ratio (mass%) of each component in Table 1 means the value of the solids content of each component relative to the total solids content of the photosensitive resin composition.

[0227]

[0228] <Preparation of metasurface structure> Each photosensitive resin composition was applied to a glass substrate using a spinner. After vacuum drying for 60 seconds, the coated substrate was obtained by heating and drying on a hot plate at 80°C for 80 seconds. Using a photomask with openings corresponding to the convex shape, the coating film was exposed using a Canon exposure machine "MPA600FA". The exposure intensity was 500 mW / cm using an illuminance meter IUC-M3 attached to the exposure machine.２ , exposure dose 120 mJ / cm ２ , under air. Next, the substrate was spray-developed for 30 seconds with an aqueous solution containing 0.04 mass % KOH (potassium hydroxide) and 0.06 mass % nonionic surfactant ("A-60" manufactured by Kao Corporation) at 24°C, and then washed with pure water for 30 seconds. These operations removed unnecessary portions of the substrate, forming a pattern of a concave-convex structure. The substrate was then exposed to an exposure light of 40 mW / cm using an exposure machine MA-1100 manufactured by Dai Nippon Kaken Co., Ltd. and an illuminance meter UV-MO3 (detector SN35) manufactured by ORC Corporation. ２ , exposure dose 1000 mJ / cm ２After the entire surface was exposed to light with UV light, the substrate was heated and cured in an oven at 230°C for 30 minutes. Next, a silver nanoink (Smart Jet I S-CS01520 manufactured by GenesInk) diluted with diethylene glycol monobutyl ether using a Fujifilm DMP-2831 was inkjet coated into the recesses and dried by heating, forming the conductive portions of Examples 1 to 5. In Comparative Example 1, a concave-convex pattern was formed without using a liquid repellent agent, and the silver nanoink was inkjet coated in the same manner as in Examples 1 to 5. In Comparative Example 2, the silver nanoink was inkjet coated in the same manner as in Examples 1 to 5 without forming a concave-convex pattern. In Comparative Example 3, the silver nanoink was inkjet coated on the substrate before coating with the photosensitive resin composition in the same manner as in Examples 1 to 5. Furthermore, in Comparative Examples 4 and 5, no conductive portions were formed, and a cured coating film of the photosensitive resin composition without a concave-convex pattern was used as Comparative Example 4, and the substrate alone was used as Comparative Example 5. In Example 6, silver nanoink (Smart Jet I S-CS01520, manufactured by GenesInk) diluted with diethylene glycol monobutyl ether was dropped onto a screen to spread the ink over the mesh portion. A substrate having a concave-convex pattern prepared in the same manner as in Examples 1 to 5 was then placed below the mesh, and the ink was then swept with a urethane rubber squeegee to screen-print the silver nanoink onto the concave-convex pattern. This was then heated and dried to form a conductive portion. In Example 7, silver nanoink (Smart Jet I S-CS01520, manufactured by GenesInk) diluted with diethylene glycol monobutyl ether was dropped near the concave-convex pattern prepared in the same manner as in Examples 1 to 5, and a 4 mm diameter stainless steel rod was then swept over the concave-convex pattern to form a bar coat of the silver nanoink. This was then vacuum dried and heated to form a conductive portion. In Example 8, silver nanoink (Smart Jet I S-CS01520, manufactured by GenesInk) diluted with diethylene glycol monobutyl ether was dropped onto the concave-convex pattern prepared in the same manner as in Examples 1 to 5, and the silver nanoink was spin-coated at 2000 rpm for 5 seconds. After that, the silver nanoink was vacuum-dried and heated to form a conductive portion.In Example 9, silver nanoink (Smart Jet I S-CS01520, manufactured by GenesInk) diluted with diethylene glycol monobutyl ether was dropped onto a concave-convex pattern prepared in the same manner as in Examples 1 to 5, and the silver nanoink was spread using an air knife. Subsequently, the ink was vacuum dried and dried by heating to form a conductive portion. In Example 10, silver nanoink (Smart Jet I S-CS01520, manufactured by GenesInk) diluted with diethylene glycol monobutyl ether was dropped onto a concave-convex pattern prepared in the same manner as in Examples 1 to 5, and the ink was pressed onto a glass substrate to spread the silver nanoink. After peeling off the substrate, the ink was vacuum dried and dried by heating to form a conductive portion. The constituent materials and production conditions for Examples 1 to 10 and Comparative Examples 1 to 5 are listed in Table 2.

[0229]

[0230] <Preparation and Evaluation of Substrates for Contact Angle Measurement> Each photosensitive resin composition was applied to a glass substrate using a spinner so as to have the desired thickness after heat curing. After vacuum drying for 60 seconds, the composition was heated and dried on a hot plate at 80°C for 80 seconds to obtain a coated substrate. Next, the resulting coating film was exposed to an exposure device MA-1100 manufactured by Dai Nippon Kaken Co., Ltd. without using a photomask, and measured with an illuminance meter UV-MO3 (detector SN35) manufactured by ORC Corporation to obtain a contact angle of 40 mW / cm. ２ , exposure dose 60 mJ / cm ２ The entire surface was exposed to a 1000 mJ / cm 2 exposure using an exposure machine MA-1100 manufactured by Dai Nippon Kaken Co., Ltd. The substrate was then spray-developed with a 0.04% by mass aqueous solution of potassium hydroxide (KOH) at 24°C for 30 seconds, and then washed with pure water for 30 seconds. ２ The coating was then exposed to light at 2000 K and then cured by heating in an oven at 230°C for 30 minutes to obtain a fully coated substrate for contact angle measurement corresponding to the surface of the convex portions. Furthermore, by utilizing the fact that the durability to washing during the subsequent development process is reduced by reducing the exposure dose to the coating, segregated portions of the liquid repellent agent on the surface can be removed. As a result, the wettability of the wall surface of the convex portions where no liquid repellent agent is present can be simulated. Specifically, the exposure dose to the coating was 20 mJ / cm ２The same treatment as in the method for preparing the contact angle measurement substrate was carried out except that the surface roughness was reduced to 0.05, to obtain an entirely coated substrate for measuring the contact angle of the wall surface of the pseudo convex portion.

[0231] The contact angle was measured using a contact angle measuring device, Drop Master 500, manufactured by Kyowa Interface Science Co., Ltd., under conditions of 23°C and relative humidity of 50%. 0.7 μL of diethylene glycol monobutyl ether was dropped onto the contact angle measurement substrate, and the contact angle was measured after 1 second. The evaluation results are shown in Table 3.

[0232] <Evaluation of Conductive Part Pattern Formation> The conductive part shape of the metasurface conductive part pattern was a resonator shape similar to that shown in Figure 2. The black areas represent recesses and conductive parts, and the line width of the conductive part is 56 μm. The state of the conductive part of the fabricated pattern was observed using a reflected bright-field optical microscope (Nikon ECLIPSE L200) to evaluate whether the conductive part pattern for the metasurface could be formed. If the silver nanoink forms a smooth conductive film after application, the reflected light is observed to be stronger than that of the surrounding resin part, allowing the state of the conductive part to be evaluated.

[0233] For Examples 1 to 10, the evaluation results regarding the contact angle on the resin surface, the application of silver nanoink, the state of the conductive part after drying, and whether or not a conductive pattern for a metasurface could be created are shown in Table 3.

[0234]

[0235] In Examples 1 to 4, the conductive portions were formed along the recess pattern, and the uniform, strong reflected light was observed, indicating the formation of a uniform film. Observation using a scanning electron microscope (SU1510, manufactured by Hitachi High-Technologies Corporation) confirmed the formation of a uniform 100-nm film of deposited silver nanoparticles. In Examples 1 to 4, in addition to the presence of the recess pattern, the effect of the liquid-repellent agent 1a segregated on the convex surface resulted in a high surface contact angle, which is thought to be the reason why the coating liquid easily fell into the recesses. In Example 5, a different liquid-repellent agent 1b was used than in Examples 1 to 4, resulting in a small contact angle and some breakage. However, a better conductive pattern for the metasurface was formed compared to the comparative example. In Examples 6 to 10, ink was applied using a method other than inkjet printing. Although some unevenness was observed in the coated film obtained by screen printing in Example 6, a better conductive portion was formed compared to the comparative example. Uniform conductive films were obtained in Examples 7 to 10. Furthermore, good conductive patterns for the metasurface were formed using both application methods.

[0236] For Comparative Examples 1 to 5, the evaluation results regarding the contact angle on the resin surface, the application of silver nanoink, the state of the conductive part after drying, and whether or not a conductive pattern for a metasurface could be created are shown in Table 4.

[0237]

[0238] In Comparative Example 1, the resin portion did not contain a liquid-repellent agent, resulting in a low surface contact angle of the convex portions, preventing the silver nanoink from falling into the concave portions and remaining on the convex portions. This result suggests that in order to form a conductive pattern for a metasurface, not only the resin portion's uneven structure but also the convex portion's surface must be liquid-repellent. In Comparative Example 2, the resin portion did not contain an uneven structure, causing the applied silver nanoink droplets to aggregate and form a discontinuous pattern, preventing the formation of a conductive pattern for a metasurface. This result suggests that not only liquid-repellent properties but also an uneven structure of the resin portion are necessary. In Comparative Example 3, the resin portion was absent and the silver nanoink was applied to the surface of the substrate portion, causing the ink to spread throughout the entire periphery of the application area, preventing the formation of a conductive pattern for a metasurface. This result suggests that not only the substrate portion but also liquid-repellent properties and an uneven structure of the resin portion are necessary. In Comparative Example 4, there was no conductive portion, and in Comparative Example 5, there were no conductive portions or resin portions, making it impossible to form a conductive pattern for a metasurface.

[0239] Table 5 shows the contact angle measurements of the upper surface of the convex portion and the wall surface of the pseudo-convex portion under the same component conditions as in Example 1. The contact angle of the upper surface of the convex portion with diethylene glycol monobutyl ether was 47°, while the contact angle of the wall surface of the pseudo-convex portion was 4.4°. These results indicate that the upper surface of the convex portion has low ink wettability and is easily repelled, while the wall surface of the convex portion has high wettability, allowing the ink to easily spread into the concave portion. A concave-convex structure with different wettability between the convex surface and the concave portion is considered advantageous for forming a targeted metasurface structure, as it makes it easier to introduce conductive regions locally only within the concave portion, compared to a concave-convex structure with overall liquid repellency or an overall liquid-philic concave-convex structure. Furthermore, segregating the liquid repellent agent only on the upper surface of the convex portion is important for imparting different wettability to the convex surface and the concave portion.

[0240]

[0241] (Electromagnetic wave absorption rate measurement method) In order to confirm the metasurface performance of the metasurface structure, the electromagnetic wave response characteristics of Example 1 were measured by the free space method. The free space method is a method in which a measurement sample is placed in the center of the transmitting antenna and the receiving antenna, electromagnetic waves are irradiated perpendicularly onto the sample, and the S parameters of the reflected wave and transmitted wave are measured. The measurement frequency was 26.5 to 110 GHz. Since the metasurface shape of Example 1 produces strong absorption near the resonance frequency, the electromagnetic wave absorption rate was calculated using the following formula. Absorption rate (%) = (1 - |S １１ | ２ - | S １２ | ２ ) x 100 where S １１ represents the ratio of reflected power to incident power, and S １２ represents the ratio of transmitted power to incident power.

[0242] 1 were formed in an area of ​​60.12 mm x 60.12 mm on a glass substrate, with 90 electromagnetic wave resonators in each direction at a pitch of 668 μm, for a total of 8,100 resonators, and the samples were measured using the free space method. For comparison, measurements were also made on Comparative Example 4, in which a resin portion with a thickness of 500 nm was applied to the glass substrate and no uneven structure or conductive portion was present, and Comparative Example 5, in which only the glass substrate was used and no resin portion or conductive portion was present.

[0243] (Method for measuring the conductivity of the conductive portion) A conductive portion was formed in the same manner as in Example 1 so as to bridge between the electrodes formed on the glass substrate, and its conductivity was measured. The conductive portion had a line width of 45 μm, a thickness of 0.2 μm, and a length of 500 μm. The resistance value of this conductive portion was measured using a resistance measuring device (IDM 67 manufactured by ISO-TECH), and the conductivity was calculated using the following formula: Conductivity (S / m) = Volume of conductive portion / Resistance value

[0244] (Simulation method) A unit structure similar to that of Example 1 was reproduced in an RF module using simulation software COMSOL Multiphysics (registered trademark), and periodic boundary conditions were applied so that the units were arranged infinitely in the vertical and horizontal directions at a pitch of 0.668 mm. The parameters used in the simulation are shown in Table 6. The electromagnetic wave had an electric field parallel to the vertical direction in Figure 1 and was incident from the resin part side, and the S parameter was calculated to calculate the absorption rate using the following formula. Absorption rate (%) = (1 - |S１１ | ２ -|S １２ | ２ )×100 As Comparative Example 6, a structural model similar to that used in the simulation of Example 1 was prepared, except that a resin portion with a thickness of 0.1 μm was inserted below the conductive portion, and the absorption rate was calculated in the same manner as above.

[0245] In Table 6, j represents the imaginary unit.

[0246] The measurement and simulation results are shown in Table 7. In Example 1, a strong absorption peak appeared at 72 GHz, near the resonant frequency of the resonator, and the results were generally consistent with the simulation results. These results confirmed that Example 1 exhibited metasurface performance as predicted by the simulation. Furthermore, since similar shapes were formed in Examples 2 to 4 and 6 to 10, it is believed that equivalent performance was exhibited. On the other hand, in Comparative Examples 4 and 5, almost no absorption was observed, confirming that metasurface performance was not exhibited. Furthermore, in the simulation results for Comparative Example 6, in which a resin layer was present below the conductive portion, the peak frequency shifted to the higher frequency side and the absorption rate also decreased compared to the simulation results for Example 1. These results demonstrate that it is more preferable for the bottom of the recess to be the surface of the substrate, rather than a resin portion.

[0247]

[0248] According to the present invention, it is possible to provide a metasurface structure having a fine conductive material pattern as designed. Such a metasurface structure can exhibit desired radio wave control characteristics such as reflection, absorption, transmission, and refraction according to the designed shape, even when using highly directional millimeter waves, thereby reducing coverage holes. Therefore, the use of the metasurface structure of the present invention can ensure communication paths in next-generation communications without increasing the number of base stations, making it highly valuable for industrial use.

[0249] REFERENCE SIGNS LIST 10 metasurface structure 11 resin part 12 conductive part 13 substrate 14 liquid-repellent part

Claims

1. A metasurface structure comprising a resin part, a conductive part, and a substrate, wherein the resin part forms a concave-convex structure on the substrate, the convex part surfaces of the concave-convex structure have liquid repellency, and the conductive part is formed by filling a conductive material into at least a part of the concave-convex structure; A metasurface structure in which the contact angle after dropping diethylene glycol monobutyl ether onto the upper surface of the convex portion is 20° or more.

2. The metasurface structure according to claim 1 , wherein a single or multiple shapes made of the conductive portion are periodically and repeatedly arranged.

3. The metasurface structure according to claim 1 or 2, wherein at least a portion of the bottom surface of the recess is the substrate surface and the side surface is made of the resin portion.

4. The metasurface structure according to claim 1 or 2, wherein the contact angle of the wall surface of the convex portion is smaller than the contact angle of the upper surface of the convex portion.

5. A metasurface structure as described in claim 1 or 2, wherein the contact angle after diethylene glycol monobutyl ether is dropped onto the wall surface of the convex portion is less than 20°.

6. The metasurface structure according to claim 1 or 2, wherein the height of the convex portions of the uneven structure is 10 nm or more and 100 μm or less.

7. The metasurface structure according to claim 1 or 2, wherein the height of the conductive portion is 5 nm or more and 10 μm or less.

8. The metasurface structure according to claim 1 or 2, wherein the ratio of the height of the conductive portion to the height of the convex portion (height of the conductive portion / height of the convex portion) is 0.01 or more and 1 or less.

9. The metasurface structure according to claim 1 or 2, wherein the line width of the conductive portion is 1 μm or more and 1 mm or less.

10. The metasurface structure according to claim 1 or 2, wherein the conductivity of the conductive portion is 100 S / m or more.

11. The metasurface structure according to claim 1 or 2, wherein the conductive portion is made of an aggregate of metal nanoparticles.

12. The metasurface structure according to claim 1 or 2, wherein the cross-sectional shape of the concave portion of the uneven structure is approximately rectangular.

13. The metasurface structure according to claim 1 or 2, wherein the substrate is a glass substrate or a resin substrate.

14. The metasurface structure according to claim 1 or 2, wherein the resin portion is formed by curing a photosensitive resin composition containing (A) a photopolymerization initiator, (B) an alkali-soluble resin, (C) a photopolymerizable compound, and (D) a liquid-repellent agent.

15. The metasurface structure according to claim 14, wherein the content of the liquid repellent agent (D) in the solid content of the photosensitive resin composition is 0.01 mass% or more.

16. A method for manufacturing a metasurface structure, comprising the following steps (1) to (3). (1) A coating step of coating a substrate with a photosensitive resin composition containing (A) a photopolymerization initiator, (B) an alkali-soluble resin, (C) a photopolymerizable compound, and (D) a liquid repellent agent. (2) A resin part forming step in which the substrate coated with the photosensitive resin composition obtained in the coating step is exposed to light and then developed to form a resin part having a concave-convex structure. (3) a conductive portion forming step of applying a composition containing a conductive material to the recesses of the uneven structure obtained in the resin portion forming step;

17. The method for manufacturing a metasurface structure according to claim 16, wherein in the step (3), the composition containing the conductive material is applied using an inkjet printer.

18. The method for manufacturing a metasurface structure described in claim 16, wherein in the step (3), the composition containing the conductive material is applied using a screen for screen printing.

19. The method for manufacturing a metasurface structure according to claim 16, wherein in the step (3), the composition containing the conductive material is applied using a bar coater.

20. The method for manufacturing a metasurface structure according to claim 16, wherein in the step (3), the composition containing the conductive material is applied using a spin coater.

21. The method for manufacturing a metasurface structure described in claim 16, wherein in the step (3), the composition containing the conductive material is applied using an air knife.

22. The method for manufacturing a metasurface structure described in claim 16, wherein in the step (3), the composition containing the conductive material is applied using a pressing substrate.

23. The method for manufacturing a metasurface structure according to any one of claims 16 to 22, wherein in the step (3), the composition containing the conductive material is heated and dried at 100 ° C. or higher within 40 minutes after application.

24. The method for manufacturing a metasurface structure according to any one of claims 16 to 22, wherein in the step (3), the composition containing the conductive material contains a solvent having a boiling point of 180 ° C. or higher.