Coating agent for lift-off process and method for producing multilayer object

Abstract

The present disclosure makes it possible to provide a coating agent for a lift-off process including a step for pattern formation without exposure to light, the coating agent being excellent in terms of fine-line reproduction, immersion cleaning, printability, and long-term stability. This coating agent for a lift-off process including a step for pattern formation without exposure to light comprises an aqueous resin having an acidic group and fine inorganic particles.

Description

Coating agent for lift-off process and method for manufacturing laminate

[0001] The present invention relates to a coating agent for a lift-off process and a method for producing a laminate.

[0002] Conventionally, lift-off and photolithography methods have been the main methods used to form finely patterned electrode layers on the substrates of electronic components such as semiconductors and solar cell panels. However, from the perspective of improving productivity, the lift-off method (lift-off process), which does not require an etching process, is attracting attention.

[0003] The lift-off process generally involves the following steps: (1) forming a resist layer by applying a photoresist film or a photoresist liquid to a substrate, (2) exposing the resist layer using a photomask, (3) removing unnecessary resist layer using a developer to form a resist pattern, (4) forming an electrode layer on the substrate and the resist layer by sputtering or vapor deposition, and (5) finally removing the resist pattern to form a patterned electrode layer. However, this method still requires many steps and is a bottleneck in the production of semiconductors and solar cell panels, so further improvements in production efficiency are required. To improve productivity, processes are being developed in which a patterned resist layer is formed by printing in the above step (1) and does not include the above steps (2) and (3), and these processes are also included in the lift-off process. Specifically, (1') a patterned resist film (resist pattern) is formed on a substrate by gravure printing or the like without exposure, (2') an electrode layer is formed on the substrate and the resist layer by sputtering or vapor deposition, and (3') finally, the resist pattern is removed to form a patterned electrode layer.

[0004] Patent Document 1 proposes a method of pattern-coating a coating agent containing hydroxypropyl cellulose by gravure printing instead of the resist film formed by steps (1) to (3) of the lift-off process. Patent Document 2 proposes a method of pattern-coating a coating agent containing hydroxypropyl cellulose and inorganic fine particles by silk screen printing instead of the resist film formed by steps (1) to (3) of the lift-off process. However, the coating agents containing hydroxypropyl cellulose described in Patent Documents 1 and 2 do not contain a resin with an acidic group and have low solubility in water, so there is a concern that they may not be sufficiently removed when washed with water.

[0005] JP 2002-200833 A JP 2013-258215 A JP 2013-257669 A

[0006] Patent Literature 3 discloses a method for manufacturing a touch panel substrate, comprising a transparent substrate, a transparent electrode, and a metal electrode, in which at least one of the transparent electrode and the metal electrode is formed by a lift-off method using a water-soluble resist agent containing at least one of a water-soluble polyester and a hydroxyalkyl cellulose, in order to improve the manufacturing efficiency of the touch panel substrate. In the examples disclosed in Patent Literature 3, hydroxypropyl cellulose is used, so there is a concern that the resist film may not be sufficiently removed by washing with water. Furthermore, in the examples disclosed in Patent Literature 3, the same level of releasability is achieved by using a water-soluble polyester as well as hydroxypropyl cellulose, so there is a concern that the resist film may not be sufficiently removed by washing with water, as in the prior art.

[0007] When printing coating agents, fine print reproducibility becomes important as electrode layer patterns become finer. Because coating agents contain inorganic fine particles, a decrease in the dispersibility of the inorganic fine particles results in insufficient fine print reproducibility in printing. Therefore, a coating agent that has excellent dispersibility of inorganic fine particles in the coating agent and high cleanability when washed with water is desired. While water-soluble polymers are expected to be cleanable by washing with water, they do not improve the dispersibility of inorganic fine particles. The water-soluble polyester disclosed in Patent Document 3 is rendered water-soluble by using 5-sodium sulfonate dimethylisophthalate as the polycarboxylic acid component, but the technology disclosed in Patent Document 3 relates to a high-viscosity resist agent and does not consider the dispersibility of inorganic fillers.

[0008] The present invention relates to a coating agent for a lift-off process, which includes a pattern formation step that does not rely on exposure, and which has excellent fine line reproducibility, immersion cleanability, printability, and stability over time.

[0009] As a result of extensive research into the above-mentioned problems, the inventors have found that the above-mentioned problems can be solved by using the packaging material described below, and have thus completed the present invention.

[0010] That is, the present invention relates to the following [1] to

[14] .

[0011] [1] A coating agent for a lift-off process including a pattern formation step that does not rely on exposure, the coating agent comprising an aqueous resin having acidic groups and inorganic fine particles.

[0012] [2] The coating agent according to [1], wherein the aqueous resin having an acidic group comprises at least one selected from the group consisting of a polyvinyl alcohol-based resin (A) having an acidic group and a polysaccharide-based resin having an acidic group.

[0013] [3] The coating agent according to [1] or [2], wherein the content of the inorganic fine particles is 3 to 20 mass % in 100 mass % of the coating agent.

[0014] [4] The coating agent according to any one of [1] to [3], which is for gravure printing or flexographic printing.

[0015] [5] The coating agent according to any one of [1] to [4], further comprising an aqueous resin having no acidic group.

[0016] [6] The coating agent according to [5], wherein the mass ratio of the aqueous resin having an acidic group to the aqueous resin not having an acidic group is 9:1 to 1:9.

[0017] [7] The coating agent according to any one of [1] to [6], wherein the inorganic fine particles are at least one selected from the group consisting of calcium carbonate, barium sulfate, magnesium carbonate, silica, titanium oxide, talc, montmorillonite, kaolin, and mica.

[0018] [8] The coating agent according to any one of claims [1] to [7], wherein the inorganic fine particles have an average particle size of 5 μm or less as measured by a laser scattering method.

[0019] [9] The coating agent according to any one of [1] to [8], wherein the mass ratio of the aqueous resin having acidic groups to the inorganic fine particles is 1:0.2 to 1:3.

[0020]

[10] The coating agent according to any one of [1] to [9], further comprising an alcohol-based organic solvent.

[0021]

[11] The coating agent according to

[10] , wherein the alcohol-based organic solvent is at least one selected from the group consisting of methanol, ethanol, isopropanol, and n-propanol.

[0022]

[12] The coating agent according to any one of [1] to

[12] , having a viscosity of 20 to 450 mPa·s at 25°C and a solid content of 18% by mass, as measured in accordance with JIS K 7117-1.

[0023]

[13] The coating agent according to any one of [1] to

[12] , wherein the pH of the water extracted with the inorganic fine particles is 7.5 to 14.0 as measured by the following measurement method: (Measurement method) 5 parts of the inorganic fine particles and 100 parts of ion-exchanged water are mixed and boiled for 5 minutes, and after stirring for 30 minutes, the pH of the supernatant water is measured with a pH meter in accordance with JIS Z 8802.

[0024]

[14] A method for producing a laminate, comprising: a step of printing a coating agent for lift-off, which contains an aqueous resin having acidic groups and inorganic fine particles, onto a part of a substrate to form a patterned coating layer without exposure to light; a step of forming electrode layers on the substrate and on the coating layer, thereby obtaining a laminate (C) having the coating layer and the electrode layer on the substrate; and a step of immersing the laminate (C) having the coating layer and the electrode layer on the substrate in a coating layer removal liquid to remove the coating layer, thereby obtaining a laminate (D) having a patterned electrode layer on the substrate.

[0025] The present invention makes it possible to provide a coating agent for a lift-off process, including a pattern formation step that does not rely on exposure, that is excellent in fine line reproducibility, immersion cleanability, printability, and stability over time.

[0026] Fig. 1 is an image showing a state in which a pattern coating layer is formed by printing the coating agent of the present invention on a substrate in a lift-off process. Fig. 2 is an image showing a state in which an electrode layer is formed on the substrate and the pattern coating layer shown in Fig. 1 in a lift-off process. Fig. 3 is an image showing a state in which an electrode layer is formed on the substrate by removing the pattern coating layer shown in Fig. 2 using a coating layer removal liquid in a lift-off process.

[0027] The following describes in detail the embodiments of the present invention, but the embodiments or explanations of the requirements described are examples of the embodiments of the present invention, and the present invention is not limited to these contents as long as it does not exceed the gist of the present invention.

[0028] <Coating Agent for Lift-Off Process> The coating agent of the present invention is characterized by comprising an aqueous resin having acidic groups and inorganic fine particles, and being used for a lift-off process including a pattern formation step that does not involve exposure. In a typical lift-off process, the method for forming a patterned resist film is not limited, but the "lift-off process" of the present invention is one in which a coating layer (resist film) made of a coating agent is removed to form a layer having a patterned electrode layer. Specifically, it can be a process in which a patterned resist film is formed using a known printing method such as gravure printing and then removed. In the present invention, by forming a patterned resist film without exposure, an exposure step is not required when forming a patterned resist film, and this process differs from known techniques in which an exposure step is essential. The present invention relates to a coating agent for a lift-off process which includes a pattern formation step not involving exposure, and is preferably used in the steps of: printing the coating agent of the present invention onto a part of a substrate to form a patterned coating layer; forming electrode layers on the substrate and on the coating layer to obtain a laminate (C) having a coating layer and an electrode layer on the substrate; and immersing the substrate in a coating layer removal liquid to remove the coating layer and the electrode layer to obtain a laminate (D) having a patterned electrode layer on the substrate.

[0029] As described above, the lift-off process of the present invention, which includes a pattern formation step not involving exposure, is a process in which a release layer such as a resist is patterned using a known printing method such as gravure printing, followed by the formation of a film of an electrode material, and the release layer such as the resist is peeled off to form an electrode. The lift-off process is also known as the scheelite process or scheelite processing, but these are the same process. The lift-off process, which includes a pattern formation step not involving exposure, includes, for example, gravure printing the coating agent of the present invention to form a pattern coating layer 2 in areas of a substrate 1 where an electrode layer 3 is not required ( FIG. 1 ), then forming an electrode layer 3 on the substrate 1 and the pattern coating layer 2 using an electrode material such as indium tin oxide by a method such as sputtering ( FIG. 2 ), and finally removing the pattern coating layer 2 using a coating layer remover described below. This allows the electrode layer 3 to be formed only in the necessary areas ( FIG. 3 ). The thin line reproducibility, which is the objective of the present invention, is evaluated by evaluating whether or not the thin lines in the final electrode layer break. By using the coating agent of the present invention, the above-mentioned pattern coating layer can be formed with high precision, thereby suppressing electrode layer breakage. The coating agent of the present invention can be used in a lift-off process including a pattern formation step that does not rely on exposure, and is preferably used to form a finely patterned electrode layer on the substrate of an electronic component used in the manufacture of, for example, a semiconductor or solar panel.

[0030] The coating agent of the present invention preferably has a viscosity of 20 to 450 mPa·s, more preferably 100 to 300 mPa·s, and even more preferably 200 to 280 mPa·s, at 25°C and a solids content of 18% by mass, as measured in accordance with JIS K7117-1. When the viscosity of the coating agent at 25°C and a solids content of 18% by mass is within the above range, viscosity adjustment for printing, etc. using a dilution solvent is possible while maintaining the necessary solids content, resulting in good fine-line reproducibility, printability, and stability over time. Furthermore, from the viewpoint of the appropriate viscosity for gravure printing and flexographic printing, which are capable of high-speed printing, the viscosity at 25°C and a 10% solids content is preferably 20 to 200 mPa·s, more preferably 50 to 150 mPa·s. When the viscosity of the coating agent at 25°C and a 10% solids content is within the above range, good fine-line reproducibility and printability are achieved.

[0031] The coating agent of the present invention contains an aqueous resin having acidic groups and inorganic fine particles, and the acidic groups of the aqueous resin are adsorbed onto the surface of the inorganic fine particles, forming a highly stable inorganic fine particle dispersion. This dispersion has viscoelasticity suitable for high-speed printing and high solubility in water. Furthermore, since the inorganic fine particle dispersion has viscoelasticity suitable for high-speed printing, it is possible to form a highly accurate pattern coating layer, thereby suppressing breakage of the electrode layer. Therefore, excellent fine line reproducibility, immersion cleanability, and stability over time can be achieved. However, the above-mentioned effects are based on scientific considerations, and the present invention is not limited to those that exhibit only these effects.

[0032] For the reasons described above, the coating agent of the present invention is suitable for printing at a printing speed of, for example, 10 m / min or more, and also suitable for high-speed printing at 50 m / min or more, 100 m / min or more, or 120 m / min or more. The coating agent of the present invention can exhibit excellent fine-line reproducibility even in high-speed printing at a printing speed of 120 m / min or more, particularly in gravure printing, which has high productivity.

[0033] <Aqueous Resin Having Acidic Groups> The coating agent of the present invention contains an aqueous resin having acidic groups. The aqueous resin is a resin that is miscible with the aqueous solvent described below and is soluble in an aqueous coating layer removal solution. The acidic group preferably has the ability to adsorb to inorganic fine particles, and known acidic groups such as sulfonic acid groups, carboxyl groups, and phenolic hydroxyl groups can be used, with carboxyl groups being preferred.

[0034] Examples of the resin skeleton of the aqueous resin having an acidic group include polyvinyl alcohol-based resins, acrylic resins, styrene-acrylic resins, styrene-maleic acid resins, urethane resins, polylactic acid resins, resol-type phenolic resins, methylolated urea resins, methylolated melamine resins, polyethylene oxide, polyacrylamide, polysaccharide-based resins, and modified resins thereof. These aqueous resins having an acidic group can be used alone or in combination of two or more. Among the above, one or more selected from the group consisting of polyvinyl alcohol-based resins, acrylic resins, and polysaccharide-based resins are preferred, polyvinyl alcohol-based resins and / or polysaccharide-based resins are more preferred, and polyvinyl alcohol-based resins are even more preferred. The polysaccharide-based resin may be any known compound in which two or more monosaccharides are bonded, such as cellulose-based resins, pullulan, starch, agarose, and gum arabic, with one or more selected from the group consisting of cellulose-based resins, pullulan, and starch being preferred. In the case of a resin skeleton that does not have an acidic group, acidic groups can be added by acid modification using a known method.

[0035] Polyvinyl alcohol-based resins tend to thicken in aqueous solution, making them difficult to remove when washed with water. However, when polyvinyl alcohol-based resins contain acidic groups, the acidic groups can stabilize the dispersibility of inorganic fine particles, further increasing their solubility in water and improving their cleanability when washed with water. Polysaccharide-based resins also tend to thicken in aqueous solution, but when polysaccharide-based resins contain acidic groups, the dispersibility of inorganic fine particles and their cleanability when washed with water can be improved. Carboxymethyl cellulose (CMC) can be preferably used as a polysaccharide-based resin having acidic groups. Carboxymethyl cellulose can improve the dispersibility of inorganic fine particles. From the viewpoint of suppressing thickening and improving cleanability with water, it is preferable that the etherification degree of carboxymethyl cellulose is 0.5 or more, 0.6 or more, or 0.7 or more. Within these ranges, thickening of carboxymethyl cellulose can be suppressed and cleanability with water can be improved, even when affected by environmental factors such as temperature and pH.

[0036] From the viewpoints of fine line reproducibility, immersion cleanability, printability, and stability over time, the content of the aqueous resin having an acidic group is preferably 1 to 30 mass %, more preferably 2 to 15 mass %, and even more preferably 3 to 8 mass %, relative to 100 mass % of the coating agent.

[0037] <Polyvinyl alcohol-based resin (A)> As described above, the aqueous resin having an acidic group is preferably a polyvinyl alcohol-based resin (A) having an acidic group. The polyvinyl alcohol-based resin (A) may be any resin having the above-mentioned acidic group and vinyl alcohol units, and may further be an ethylene-vinyl alcohol resin containing ethylene-derived structural units.

[0038] The degree of polymerization of the polyvinyl alcohol-based resin (A) is preferably 100 to 3,000, and more preferably 500 to 2,400. When the degree of polymerization of the polyvinyl alcohol-based resin (A) is within the above range, the immersion cleanability, fine line reproducibility, printability, and stability over time are improved.

[0039] The content of ethylene-derived structural units in the polyvinyl alcohol-based resin (A) is preferably 1 to 40 mol%, more preferably 3 to 20 mol%, and even more preferably 5 to 15 mol%. When the content of ethylene-derived structural units is within the above range, the immersion cleanability and stability over time are improved.

[0040] The polyvinyl alcohol-based resin (A) can be used that has been crosslinked with a crosslinking agent. Examples of the crosslinking agent that can be used include known crosslinking agents such as an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, a melamine-based crosslinking agent, an oxazoline-based crosslinking agent, and a silane coupling-based crosslinking agent, and the oxazoline-based crosslinking agent and / or a silane coupling-based crosslinking agent are preferred.

[0041] The degree of saponification of the polyvinyl alcohol-based resin (A) is represented by the following formula (2), and is preferably 80 mol% or more, more preferably 90 mol% or more, and preferably 95 mol% or more. When the degree of saponification of the polyvinyl alcohol-based resin (A) is within the above range, the immersion cleanability and stability over time are improved. (Formula 2) Saponification degree: (number of hydroxyl groups) / {(number of hydroxyl groups)+(number of acetate groups)}×100 [mol%]

[0042] Commercially available polyvinyl alcohol resins (A) include, for example, Kuraray Poval 25-88KL (manufactured by Kuraray Co., Ltd., itaconic acid-modified polyvinyl alcohol resin), 6-77KL (manufactured by Kuraray Co., Ltd., acid-modified polyvinyl alcohol resin), Gohsenex L-3266, and CKS-50 (manufactured by Mitsubishi Chemical Corporation, sulfonic acid-modified polyvinyl alcohol resin).

[0043] <Aqueous Resin Not Having Acidic Groups> The coating agent of the present invention preferably further contains an aqueous resin not having acidic groups. Examples of aqueous resins not having acidic groups include polyvinyl alcohol-based resins, acrylic resins, styrene-acrylic resins, styrene-maleic acid resins, urethane resins, polylactic acid resins, polysaccharide-based resins, and modified resins thereof. These hydrophilic resins can be used alone or in combination of two or more. Among the above, it is preferable to contain a polyvinyl alcohol-based resin.

[0044] From the viewpoints of fine line reproducibility, printability and immersion cleanability, the content of the aqueous resin having no acidic group is preferably 0.1 to 30 mass %, more preferably 1 to 15 mass %, and even more preferably 2 to 8 mass %, relative to 100 mass % of the coating agent.

[0045] When the coating agent of the present invention contains both an aqueous resin having an acidic group and an aqueous resin not having an acidic group, the total content of the aqueous resin having an acidic group and the aqueous resin not having an acidic group is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, and even more preferably 5 to 15% by mass, based on 100% by mass of the coating agent, from the viewpoints of fine line reproducibility, immersion cleanability, printability, and stability over time. By making this total content 20% by mass or less, 18% by mass or less, or 15% by mass or less, the dispersibility of inorganic fine particles and the washability with water can be further improved. Furthermore, the coating agent can be made low-viscosity while maintaining the dispersibility of inorganic fine particles, and can have viscoelasticity suitable for high-speed printing.

[0046] When the coating agent of the present invention contains both an aqueous resin having an acidic group and an aqueous resin not having an acidic group, the mass ratio of the aqueous resin having an acidic group to the aqueous resin not having an acidic group is preferably 9:1 to 1:9, and more preferably 7:3 to 3:7. When the mass ratio is within the above range, fine line reproducibility, immersion cleanability, printability, and stability over time are improved.

[0047] <Polyvinyl alcohol-based resin (B)> As described above, the coating agent of the present invention preferably contains a polyvinyl alcohol-based resin (B) that does not have an acidic group, in addition to the aqueous resin having an acidic group. The polyvinyl alcohol-based resin (B) may be any resin that does not have an acidic group and has a vinyl alcohol unit, and may further contain a structural unit derived from ethylene. For example, it may be an ethylene-vinyl alcohol resin. The description of the above <Polyvinyl alcohol-based resin (A)> can be used to refer to preferred aspects of the degree of polymerization, crosslinking, and degree of saponification of the polyvinyl alcohol-based resin (B).

[0048] The polyvinyl alcohol-based resin (B) preferably contains structural units derived from ethylene, and the content of the structural units derived from ethylene in the polyvinyl alcohol-based resin (B) is preferably 1 to 40 mol %, more preferably 3 to 20 mol %, and even more preferably 5 to 15 mol %. When the content of the structural units derived from ethylene is within the above range, the immersion cleanability and stability over time are improved.

[0049] <Inorganic Fine Particles> The coating agent of the present invention contains inorganic fine particles. The inorganic fine particles are preferably particles that have been miniaturized to a degree that allows them to be dispersed in the coating agent. The inorganic fine particles may be any of metal fine particles, alloy fine particles, and inorganic compound fine particles. The inorganic fine particles may be inorganic compound fine particles, and may include at least one selected from the group consisting of inorganic oxide fine particles, inorganic carbonate fine particles, inorganic sulfate fine particles, and mineral fine particles. Examples of inorganic fine particles include titanium oxide, zinc oxide, zinc sulfide chromium oxide, aluminum particles, mica, bronze powder, chrome vermilion, yellow lead, cadmium yellow, cadmium red, ultramarine, Prussian blue, red iron oxide, yellow iron oxide, iron black, silica, barium sulfate, mica, montmorillonite, kaolin clay, talc, calcium carbonate, magnesium carbonate, etc. Preferably, the inorganic fine particles are at least one selected from the group consisting of calcium carbonate, barium sulfate, magnesium carbonate, silica, titanium oxide, talc, montmorillonite, kaolin, and mica, and more preferably calcium carbonate. From the viewpoint of suppressing sedimentation in the coating agent, the specific gravity of the inorganic fine particles is preferably 1.5 to 6, 2 to 4, or 2.4 to 2.7. Calcium carbonate is preferable because it has a low specific gravity and is less likely to sediment, thereby improving the stability of the coating agent and minimizing the increase in viscosity of the coating agent due to its oil absorption amount or shape.

[0050] The inorganic fine particles have an average particle size measured by a laser scattering method of preferably 5 μm or less, more preferably 2 μm or less, even more preferably 1 μm or less, particularly preferably 0.5 μm or less, and most preferably 0.01 to 0.1 μm. When the inorganic fine particles have an average particle size measured by a laser scattering method within the above range, fine line reproducibility, printability, and stability over time are improved.

[0051] The pH of the water extracted from the inorganic fine particles is preferably neutral to alkaline, preferably 7.5 to 14, more preferably 7.8 to 12, and even more preferably 8.0 to 9.0. When the water is alkaline, the acidic groups of the aqueous resin are easily adsorbed, thereby improving fine-line reproducibility, immersion cleaning properties, and stability over time. The pH of the water extracted from the inorganic fine particles can be determined by mixing 5 parts of the inorganic fine particles with 100 parts of ion-exchanged water, boiling the mixture for 5 minutes, stirring for 30 minutes, and then measuring the pH of the supernatant water with a pH meter in accordance with JIS Z 8802.

[0052] The specific surface area of ​​the inorganic particles is 10 to 100 m ２ / g, and 10 to 80m ２ When the specific surface area of ​​the inorganic fine particles is in the above range, the reproducibility of fine lines, printability, and stability over time are improved.

[0053] The inorganic fine particles may have any known shape, such as a spherical, square, cubic, or lamellar shape, but are preferably spherical from the viewpoint of dispersibility. When the inorganic fine particles are spherical, the fine line reproducibility, immersion cleaning property, printability, and stability over time are improved.

[0054] <Calcium Carbonate> Calcium carbonate includes natural calcium carbonate (heavy calcium carbonate) and synthetic calcium carbonate (light calcium carbonate). Natural calcium carbonate is produced directly from limestone, for example, by mechanically crushing and classifying raw limestone. Synthetic calcium carbonate is produced from calcium hydroxide, for example, by reacting calcium hydroxide with carbon dioxide. Calcium carbonate that has been surface-treated with a fatty acid, a resin acid, a silane coupling agent, or the like can also be used.

[0055] The content of inorganic fine particles in the coating agent is preferably 3 to 20 mass %, more preferably 5 to 15 mass %, based on 100 mass % of the coating agent. When the content of inorganic fine particles is within the above range, fine line reproducibility, immersion cleanability, printability, and stability over time are improved.

[0056] The mass ratio of the aqueous resin having acidic groups to the inorganic fine particles is preferably 1:0.2 to 1:3, and more preferably 1:0.8 to 1:2. When the mass ratio of the aqueous resin having acidic groups to the inorganic fine particles is within the above range, fine line reproducibility, immersion cleanability, printability, and stability over time are improved.

[0057] <Aqueous Solvent> The coating agent of the present invention preferably contains an aqueous solvent. The main component of the aqueous solvent is preferably water, but a water-soluble organic solvent can be used in addition to water. Specifically, alcohol-based organic solvents, glycol-based organic solvents, etc. can be contained depending on the printing conditions (speed, plate depth, design, drying temperature). Among these, it is preferable to contain an alcohol-based organic solvent from the viewpoints of fine line reproducibility, printability, and stability over time. Here, in the present invention, "the main component is water" means that the water content is the highest in the aqueous solvent. Furthermore, a water-soluble organic solvent refers to one that is liquid at 25°C and has a solubility in water at 25°C of 1% by mass or more.

[0058] From the viewpoints of fine line reproducibility, printability and stability over time, the content of the aqueous solvent is preferably 50 to 95 mass %, more preferably 70 to 90 mass %, relative to 100 mass % of the coating agent.

[0059] From the viewpoints of fine line reproducibility, printability and stability over time, the water content is preferably 70 to 100% by mass, and more preferably 85 to 95% by mass, based on 100% by mass of the aqueous solvent.

[0060] The content of the water-soluble organic solvent, such as an alcohol-based organic solvent or a glycol-based organic solvent, is preferably 0.1 to 30% by mass, and more preferably 1 to 15% by mass, relative to 100% by mass of the coating agent, from the viewpoints of stability over time, printability, and fine line reproducibility.

[0061] Examples of the alcohol-based organic solvent include methanol, ethanol, n-propanol, isopropanol, isobutanol, normal butanol, tertiary butanol, hexanol, octanol, decanol, etc. In the case of a coating method using gravure printing or flexographic printing, at least one solvent selected from the group consisting of methanol, ethanol, n-propanol, and isopropanol is preferred, and n-propanol is more preferred in terms of stability.

[0062] When the aqueous solvent contains water and an alcohol-based organic solvent, the mass ratio of water to alcohol-based organic solvent is preferably 70:30 to 97:3, and more preferably 85:15 to 95:5, from the viewpoints of stability over time, printability, and fine-line reproducibility.

[0063] Examples of the glycol-based organic solvent include acetylene diol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monooctyl ether, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ether, tripropylene glycol monobutyl ether, and dibutyl glycol. Among these, at least one selected from the group consisting of diethylene glycol monoethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monopropyl ether is preferred, and propylene glycol and / or propylene glycol monopropyl ether is more preferred. These water-soluble organic solvents may be used alone or in combination of two or more.

[0064] When the aqueous solvent contains water and a glycol-based organic solvent, the mass ratio of water to glycol-based organic solvent is preferably 100:10 to 100:0.2, and more preferably 100:5 to 100:0.2. When the mass ratio of water to glycol-based organic solvent is within the above range, fine line reproducibility, printability, and stability over time are improved.

[0065] <Additives> The coating agent of the present invention may contain known additives such as an isocyanate compound, a silane coupling agent, a dispersant, a stabilizer, a viscosity modifier, a colorant, etc., within the range that does not impair the effects of the present invention.

[0066] <Method for producing coating agent for lift-off process> The coating agent of the present invention can be produced, for example, by mixing an aqueous resin having acidic groups, inorganic fine particles, and, if necessary, an aqueous solvent, etc., dispersing the inorganic fine particles using a disperser, and then mixing the obtained dispersion with various additives, organic solvents, etc. As the disperser, a commonly used one, for example, a roller mill, a ball mill, a pebble mill, an attritor, or a sand mill, can be used.

[0067] <Formation of Coating Layer> A coating layer can be formed by coating the coating agent of the present invention on a substrate and removing the volatile components. The coating method is preferably printing, and examples of the printing method include conventionally known methods such as gravure printing, flexographic printing, dipping, roll coating, screen printing, and spraying. However, gravure printing and / or flexographic printing are preferred, and gravure printing is more preferred. That is, the coating agent of the present invention is preferably for gravure printing or flexographic printing, and more preferably for gravure printing.

[0068] For example, the coating agent is diluted with a dilution solvent to a viscosity and concentration suitable for gravure printing, and then supplied to each printing unit, either alone or in a mixture, and applied. The coating is then fixed by drying in an oven or the like to obtain a coating layer. The thickness of the coating layer is preferably 0.1 μm to 10 μm, more preferably 0.2 to 5 μm, even more preferably 0.3 to 3 μm, and particularly preferably 0.6 to 2 μm. The printing speed is not particularly limited, but from the viewpoint of productivity, it is preferably 10 to 300 m / min, more preferably 50 to 200 m / min, and even more preferably 80 to 150 m / min.

[0069] <Gravure Printing> (Gravure Plate) A gravure plate is a cylindrical metal plate. Methods for forming cells on a gravure plate include engraving and etching (photosensitive film application - exposure - development - etching). The etching method, which can form cells along the edges of an image, is preferred in terms of sharpening the contours of the coating layer. Furthermore, with the etching method, the accuracy of the cells can be improved by increasing the resolution during exposure. As a platemaking device, for example, a Think Laboratory laser automatic platemaking system FXIII (laser drawing resolution: longitudinal direction 3200 dpi / circumferential direction 12800 dpi) or an MDC laser platemaking device / electronic engraving machine DIGILAS5000 is preferably used, and an MDC laser platemaking device / electronic engraving machine DIGILAS5000 is more preferably used.

[0070] The line frequency, which is a parameter corresponding to the resolution during printing, is preferably 200 to 350 lines / inch. When the line frequency is 200 lines / inch or more, the edge shape of the printed portion becomes good, which tends to improve fine line reproducibility, and when it is 350 lines / inch or less, the cell opening becomes large, which improves ink transfer, which tends to improve fine line reproducibility.

[0071] The plate depth, which is a parameter that controls the amount of ink transferred, is preferably 15 to 25 μm. When the plate depth is 15 μm or more, smearing of the coating layer can be suppressed, which tends to improve fine line reproducibility. When the plate depth is 25 μm or less, the amount of coating agent applied is appropriate, which suppresses bleeding of the coating layer, which tends to improve fine line reproducibility. Furthermore, by setting the plate depth to 25 μm or less, the amount of coating agent applied can be reduced, which also reduces drying energy and improves printing speed, i.e., productivity.

[0072] In the case of slow-drying aqueous inks or polyester films with good wet spreadability, the pattern line width of the printed product tends to be wider than the plate pattern line width due to the coating agent wetting and spreading on the film. In such cases, from the viewpoint of suppressing bleeding due to the wetting and spreading of the coating layer, the ratio of the plate pattern line width to the target pattern line width (plate pattern line width / target pattern line width) is preferably 75 to 90%, more preferably 77 to 85%. When the plate pattern line width / target pattern line width is within the above range, good thin line reproducibility is achieved.

[0073] (Printing press) In a gravure printing press, one printing unit is equipped with the gravure plate and doctor blade. There are multiple printing units, and printing units corresponding to organic solvent-based printing inks and pattern inks can be set, and each unit has an oven drying unit. Printing is carried out by rotary printing, and a roll-to-roll printing method is used. The type of plate and the type of doctor blade are selected appropriately and can be selected according to specifications.

[0074] <Method for producing a laminate (D) having a patterned electrode layer on a substrate> The method for producing a laminate having a patterned electrode layer on a substrate using the coating agent for lift-off process of the present invention is characterized by the following steps: (1) a step of printing a coating agent for lift-off, which includes an aqueous resin having acidic groups and inorganic fine particles, onto a part of a substrate to form a patterned coating layer without exposure to light; (2) a step of forming electrode layers on the substrate and on the coating layer to obtain a laminate (C) having a coating layer and an electrode layer on the substrate; and (3) a step of immersing the laminate (C) having a coating layer and an electrode layer on the substrate in a coating layer removal liquid to remove the coating layer and the electrode layer formed on the coating layer.

[0075] <Example of Use> The laminate (D) having a patterned electrode layer on a substrate can be used as a part of a semiconductor, a solar cell panel, or the like, and can be used, for example, as "substrate / transparent conductive film (-)" in an example of a layered structure of a perovskite solar cell, "substrate / transparent conductive film (-) / metal oxide layer / perovskite / hole transport layer / electrode (+)."

[0076] <Substrate> The substrate is not particularly limited, but a lightweight and flexible plastic film is preferably used as the substrate, particularly for next-generation solar cells, the development of which has been heating up in recent years in an effort to realize a decarbonized society. As plastic films, polyester films, polyimide films, etc. are preferred for their weather resistance, and preferred examples of polyester films include polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). To provide the laminate with water vapor barrier properties, the substrate itself may have a barrier layer, such as a transparent vapor-deposited layer of an inorganic oxide. Furthermore, the substrate may be surface-treated, such as corona treated or flame treated, to provide easy adhesion for printing and post-processing, or may have a coating layer.

[0077] <Electrode Layer> The electrode layer can be formed by depositing a conductor on a substrate by a dry method such as vapor deposition or sputtering. Among these, sputtering is preferred, as it is suitable for forming large-area films suitable for mass production. Examples of conductors include metals such as Al, Ti, Pb, Ni, Cu, Ag, Au, Cr, Sn, and In, and oxides such as ITO, Al2O3, and SiO2. For next-generation solar cell applications, ITO is particularly suitable as a transparent electrode and is Pb-free.

[0078] <Method for Removing Coating Layer> The coating layer is exposed to the coating layer removal liquid by an appropriate method. For example, the coating layer removal liquid is sprayed onto the conductor covering the coating layer, or the coating layer and the conductor covering it are immersed in the coating layer removal liquid, thereby exposing the coating layer to the coating layer removal liquid. Immersion in the coating layer removal liquid is a preferred method for removing the coating layer.

[0079] <Coating Layer Removal Liquid> From the viewpoint of environmental friendliness, such as facilitating waste liquid treatment, it is preferable to use water as the coating layer removal liquid. Alternatively, a mixed liquid containing a water-soluble organic solvent may also be used as the coating layer removal liquid. Examples of water-soluble organic solvents include alcohols such as methanol, ethanol, 2-propanol, and 1,2-propanediol; glycol ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethyl cellosolve, propylene glycol monopropyl ether, propylene glycol monoisopropyl ether, butyl cellosolve, ethylene glycol monoisobutyl ether, propylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and dipropylene glycol monomethyl ether; and cyclohexanone. It is also preferable that the coating layer removal liquid contain at least one surfactant selected from the group consisting of nonionic surfactants, anionic surfactants, and cationic surfactants. When a mixed solution of the above solvents is used, the water content in the mixed solution is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, based on 100% by mass of the mixed solution. When the water content in the mixed solution is within the above range, fine line reproducibility tends to be improved.

[0080] <Residual Rate of Coating Layer> In the present invention, the residual rate of the coating layer is a value represented by the following formula (1) after a laminate obtained by applying a coating agent to a substrate and forming a coating layer with a thickness of 1 μm is treated under the following conditions. The residual rate of the coating layer is preferably less than 80% by mass, more preferably less than 50% by mass, even more preferably less than 10% by mass, and particularly preferably less than 5% by mass. When the residual rate of the coating layer is within the above range, the removal rate of the coating layer and unnecessary electrode layer portions during immersion cleaning is improved, which tends to improve fine line reproducibility. (Treatment Conditions) The laminate was immersed in ion-exchanged water at 40°C for 10 minutes, and then dried in an oven at 80°C for 1 minute. (Formula 1) Residual rate of coating layer (mass %) = (mass of coating layer after treatment) / (mass of coating layer before treatment) × 100

[0081] In an embodiment of the coating agent of the present invention that satisfies the requirement for the coating layer retention rate represented by the above (Equation 1), the aqueous resin having acidic groups preferably has a sulfonic acid group, a carboxyl group, or a phenolic hydroxyl group as the acidic group. The resin skeleton of the aqueous resin having acidic groups is preferably, for example, a polyvinyl alcohol-based resin (A), an acrylic resin, a styrene-acrylic resin, a styrene-maleic acid resin, a urethane resin, a polylactic acid resin, a resol-type phenolic resin, a methylolated urea (urea) resin, a methylolated melamine resin, polyethylene oxide, polyacrylamide, a polysaccharide-based resin, or a modified resin thereof. The use of the resin having the above acidic groups and a resin skeleton improves solubility in the coating agent removal solution, thereby increasing the tendency to satisfy the coating layer retention rate requirement. Furthermore, the inorganic fine particles are preferably at least one selected from the group consisting of calcium carbonate, barium sulfate, magnesium carbonate, silica, titanium oxide, talc, montmorillonite, kaolin, and mica. The inorganic fine particles are preferably spherical in shape. When the inorganic fine particles have the above-described configuration, the dispersibility between the resin having acidic groups and the inorganic fine particle dispersion formed by the inorganic fine particles is improved, and the solubility in water is improved, which increases the tendency for the residual rate of the coating layer to be satisfied.

[0082] The content of the aqueous resin having acidic groups in the coating agent is preferably 1 to 30% by mass, more preferably 2 to 15% by mass, and even more preferably 3 to 8% by mass, based on 100% by mass of the coating agent. Furthermore, the content of inorganic fine particles in the coating agent is preferably 3 to 20% by mass, based on 100% by mass of the coating agent, and the mass ratio of the aqueous resin having acidic groups to the inorganic fine particles is preferably 1:0.2 to 1:3. When inorganic fine particles are dispersed in the aqueous resin having acidic groups, their solubility in solvents such as water is improved. Therefore, when the aqueous resin having acidic groups and the mass ratio of the aqueous resin having acidic groups to the inorganic fine particles in the coating agent are within the above ranges, the tendency to satisfy the above-mentioned coating layer retention rate is enhanced.

[0083] The coating agent of the present invention preferably further contains an aqueous resin free of acidic groups, preferably a polyvinyl alcohol resin (B). The polyvinyl alcohol resin (B) preferably contains structural units derived from ethylene. The content of ethylene-derived structural units in the polyvinyl alcohol resin (B) is preferably 1 to 40 mol%, more preferably 3 to 20 mol%, and even more preferably 5 to 15 mol%. Aqueous resins tend to exhibit poor water solubility due to hydrogen bonding upon drying. Therefore, the combined use of resins with different structures reduces the hydrogen bonding strength, thereby increasing the tendency for the coating layer to satisfy the required residual rate. In particular, using a polyvinyl alcohol resin (B) containing structural units derived from ethylene as the aqueous resin free of acidic groups reduces the total amount of hydroxyl groups in the coating layer, thereby further increasing the tendency for the coating layer to satisfy the required residual rate.

[0084] The content of the aqueous resin having no acidic groups is preferably 0.1 to 30% by mass, and particularly preferably 2 to 8% by mass, relative to 100% by mass of the coating agent, and the mass ratio of the aqueous resin having acidic groups to the aqueous resin having no acidic groups is preferably 9:1 to 1:9, and particularly preferably 7:3 to 3:7. When the content of the aqueous resin having no acidic groups and the mass ratio of the aqueous resin having acidic groups to the aqueous resin having no acidic groups are within the above ranges, a good balance is achieved between the hydrogen bonding strength and the dispersibility of the inorganic fine particles, and the tendency to satisfy the above-mentioned residual rate of the coating layer is increased.

[0085] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the present invention, parts and % represent parts by mass and % by mass unless otherwise noted.

[0086] <Method for measuring pH of water extracted from inorganic fine particles> Five parts of inorganic fine particles and 100 parts of ion-exchanged water were mixed and heated for 5 minutes at 100° C. Thereafter, the mixture was cooled to room temperature, and ion-exchanged water was added so that the total amount of the inorganic fine particles and ion-exchanged water was 105 parts. After stirring, the pH was measured using a multi-pH meter (manufactured by AS ONE Corporation) in accordance with JIS Z 8802.

[0087] <Viscosity Measurement> The viscosity of the coating agent was measured in accordance with JIS K 7117-1 using a Viscometer TUB-10 manufactured by Toki Sangyo Co., Ltd. under the following conditions. When the solid content concentration was low, the solid content was adjusted by opening the lid of the storage container of the coating agent and leaving it to stand to volatilize the solvent. <Measurement Conditions> Rotor: M1 Rotation speed: 6 rpm Liquid temperature: 25°C Solid content at viscosity measurement before dilution: 18% by mass Solid content at viscosity measurement after dilution: 10% by mass

[0088] <Weight-average molecular weight measurement> The weight-average molecular weight was determined as a converted molecular weight using polyethylene glycol as a standard substance. The measuring device used was a GPC device: Shodex GPC-401 manufactured by Showa Denko K.K. The column was a Shodex OHpak LB-805 manufactured by Showa Denko K.K. The detector was an RI (differential refractometer). The eluent was 0.1N NaNO. ３The measurements were carried out using an aqueous solution at a column temperature of 35° C. and a flow rate of 3 mL / min.

[0089] <Preparation of Resin Solution> (Preparation Example 1) Resin Solution V01 12 parts of polyvinyl alcohol-based resin PVA1 and 88 parts of ion-exchanged water were heated with stirring, and the heating and stirring were continued at 90°C for 1 hour. Thereafter, heating was stopped, and stirring was continued until the temperature returned to room temperature, thereby obtaining Resin Solution V01.

[0090] (Preparation Examples 2 to 6) Resin solutions V02 to 06 Resin solutions V02 to 06 were obtained in the same manner as in Preparation Example 1, except that the raw materials and blending ratios were changed as shown in Table 1. The properties of the raw materials used in Preparation Examples 1 to 6 are as follows. Polyvinyl alcohol resin PVA1: itaconic acid-modified polyvinyl alcohol, degree of polymerization = 1800, viscosity (20°C, 4% aqueous solution) = 25 mPa·s, degree of saponification = 88%, solids content 100% Polyvinyl alcohol resin PVA2: sulfonic acid-modified polyvinyl alcohol, degree of polymerization = 300, viscosity (20°C, 4% aqueous solution) = 2.5 mPa·s, degree of saponification = 98%, solids content 100% Polyvinyl alcohol resin PVA3: ethylene vinyl alcohol resin, ethylene content: 8 mol%, degree of polymerization = 400, viscosity (20°C, 4% aqueous solution) = 4 mPa·s, degree of saponification = 98%, solids content 100% Polyvinyl alcohol-based PVA4: Kuraray Co., Ltd., Poval 28-98, unmodified polyvinyl alcohol, degree of polymerization = 1700, viscosity (20°C, 4% aqueous solution) = 28 mPa·s, degree of saponification = 98%, solids content 100% Cellulose-based resin CE1: Daicel Corporation, CMC Daicel #2200, carboxymethyl cellulose, viscosity (25°C, 1% aqueous solution) = 2200 mPa·s, solids content 100% Cellulose-based resin CE2: Nippon Soda Co., Ltd., HPC-SL, hydroxypropyl cellulose, viscosity (25°C, 10% aqueous solution) = 150 mPa·s, solids content 100%

[0091]

[0092] <Production of Coating Agent for Lift-Off Process> (Example 1) Coating Agent C1 for Lift-Off Process 75.0 parts of resin solution V01, 9.0 parts of calcium carbonate, 8.0 parts of ion-exchanged water, and 8.0 parts of n-propyl alcohol were mixed and dispersed in a bead mill for 20 minutes to obtain Coating Agent C1 for the lift-off process.

[0093] (Examples 2 to 29, Comparative Examples 1 and 2) Coating agents C2 to 31 for the lift-off process Coating agents C2 to 31 for the lift-off process were obtained in the same manner as in Example 1, except that the raw materials and blending ratios were changed as shown in Table 2. The properties of the raw materials used are as follows. The pH is the pH of the respective extracted water. Calcium carbonate CA1: Homocal D, manufactured by Shiraishi Calcium Co., Ltd., synthetic calcium carbonate, average particle size 0.08 μm, pH 8.6, solids content 100% Calcium carbonate CA2: average particle size 0.3 μm, pH 8 Calcium carbonate CA3: average particle size 1.5 μm, pH 9 Calcium carbonate CA4: average particle size 4.5 μm, pH 8.9 Silica: Sylysia 310, manufactured by Fuji Silysia Chemical Ltd., gel method silica, average particle size 1.7 μm, pH 7.5 Barium sulfate: Variace B31, manufactured by Sakai Chemical Industry Co., Ltd., precipitated barium sulfate, average particle size 0.3 μm, pH 7 Montmorillonite: Kunipia F, manufactured by Kunimine Industries Co., Ltd., swelling montmorillonite, particle aspect ratio 500, particle thickness 1 μm, average particle size 0.5 μm, pH 8 to 8.5 Titanium oxide: Titanix JR-808, manufactured by Teika Corporation, average particle size 2.3 μm, pH 7.7 Mica: average particle size 6 μm, aspect ratio 100, specific surface area 9 m ２ / g, pH 8 Kaolin: average particle size 1.2 μm, aspect ratio 100, specific surface area 10 m ２ / g, pH 6 Talc: Specialty Minerals, AlBACAR 5970, average particle size 1.9 μm, pH 8

[0094] <Production of a laminate using the coating agent of Example 1> A dilution solvent (water / n-propyl alcohol = 92 / 8) was added to the coating agent C1 for the lift-off process so that the solid content of the coating agent was 10%, and the mixture was stirred and mixed. Thereafter, the diluted lift-off process coating agent C1 was printed on the corona-treated surface of the corona-treated biaxially stretched polyester film (PET) (thickness: 50 μm) using a gravure printing machine equipped with a gravure plate (cell formation method: corrosion method, laser platemaking device D1: MDC laser platemaking device / electronic engraving machine DIGILAS5000, line count: 300 lines / inch, plate depth: 20 μm, plate pattern line width / target pattern line width: 90%) at a printing speed of 120 m / min and an in-line oven temperature of 80°C to form a coating layer, thereby obtaining an intermediate laminate having fine line patterns of the lift-off process coating agent with line widths of 20 μm, 50 μm, 100 μm, and 200 μm. The surface of the intermediate laminate printed with the fine line pattern by the coating agent for the lift-off process and the substrate without the pattern were vacuumed to a degree of 10 using an SPC series vacuum cleaner manufactured by Canon Anelva Corporation. －４ A transparent electrode layer having a thickness of 0.4 μm was formed by sputtering ITO at a pressure of 100 Pa and an applied voltage of 5.1 kV, thereby obtaining a laminate. The laminate had a substrate / coating layer / electrode layer component and a substrate / electrode layer component.

[0095] <Production of laminates using the coating agents of Examples 2 to 29 and Comparative Examples 1 and 2> Laminates were produced in the same manner as in <Production of laminates using the coating agent of Example 1>, except that the coating agents for the lift-off process and dilution solvents in Table 2 were used.

[0096] <Production of laminates in Examples 30 to 43> Laminates were produced in the same manner as in <Production of laminates using the coating agent of Example 1>, except that the coating agents and plates for the lift-off process in Table 3 were used. The plate production equipment used was as follows: Laser platemaking device D1: DIGILAS5000 manufactured by MDC Laser platemaking device D2: HelioKlischograph K500 G4 manufactured by Heliograph Japan Laser platemaking device D3: newFXIII manufactured by Think Laboratory

[0097] <Evaluation of Coating Agent and Laminate> The obtained coating agent and laminate were evaluated as follows. The results are shown in Tables 2 and 3.

[0098] <Immersion Cleanability> The obtained laminate was cut into 10 mm x 50 mm pieces, immersed in 40°C ion-exchanged water for 10 minutes, and then dried in an 80°C oven for 1 minute. The remaining rate (mass %) of the coating layer before and after cleaning was calculated and evaluated using the following formula 1. AA to C represent practical levels. When the coating agent of the present invention is used in a lift-off process, it is preferable to remove the coating layer only by immersion in ion-exchanged water in order to achieve high productivity. Therefore, the immersion cleanability test of the present invention involved only immersion in ion-exchanged water. Conventional cleanability tests involve removing the coating layer by applying pressure, such as with a water flow. However, the immersion cleanability test of the present invention differs from conventional cleanability tests in that no pressure, such as with a water flow, is applied, and is a strict test method that requires higher solubility in the cleaning solution. (Formula 1) Residual rate of coating layer (mass %) = (mass of coating layer after treatment) / (mass of coating layer before treatment) x 100 AA: Residual rate of coating layer (mass %) is less than 5 mass % A: Residual rate of coating layer (mass %) is 5 mass % or more but less than 10 mass % B: Residual rate of coating layer (mass %) is 10 mass % or more but less than 50 mass % C: Residual rate of coating layer (mass %) is 50 mass % or more but less than 80 mass % D: Residual rate of coating layer (mass %) is 80 mass % or more

[0099] <Fine Line Reproducibility> The fine line stripe pattern of the obtained laminate after the immersion cleaning test was visually observed and evaluated according to the following criteria. AA to C are practical levels. AA: No breaks in any stripe pattern. A: There are breaks in the 20 μm fine line stripe pattern, but there are no breaks in the 50 μm, 100 μm, and 200 μm fine line stripe pattern. B: There are breaks in the 50 μm fine line stripe pattern, but there are no breaks in the 100 μm and 200 μm fine line stripe pattern. C: There are breaks in the 100 μm fine line stripe pattern, but there are no breaks in the 200 μm fine line stripe pattern. D: There are breaks in the 200 μm stripe pattern.

[0100] <Stability over time> The coating agent for the lift-off process was filled into a 225 g mayonnaise bottle (body diameter 62 mm / total length 109 mm), and layer separation was confirmed after 7 days at 40°C and evaluated according to the following criteria. The length in each criterion is the layer length measured when viewing the mayonnaise bottle from the horizontal direction. A to C are practical levels. A: No layer separation B: Layer separation occurred, and a separated layer of less than 10 mm occurred C: Layer separation occurred, and a separated layer of 10 mm or more but less than 20 mm occurred D: Layer separation occurred, and a separated layer of 20 mm or more occurred

[0101] <Printability> A coating agent for the lift-off process diluted with a dilution solvent shown in Table 2 was poured into a printing ink container of a printing press, and the plate was rotated at a printing speed of 120 m / min for 60 minutes. The colored area of ​​the non-image areas on the plate was then visually evaluated, and printability was evaluated according to the following criteria. Note that in Examples 1 to 29 and Comparative Examples 1 and 2, plate D1 was used, and in Examples 30 to 45, the plates shown in Table 3 were used. Note that A to C are practical levels. A: No coloring of the non-image areas. B: Coloring of the non-image areas occurred, and the colored area was less than 5 area%. C: Coloring of the non-image areas occurred, and the colored area was 5 area% or more but less than 30 area%. D: Coloring of the non-image areas occurred, and the colored area was 30 area% or more.

[0102]

[0103]

[0104]

[0105]

[0106]

[0107] From the above results, Comparative Example 1 did not contain an aqueous resin having an acidic group, and therefore had poor fine line reproducibility, immersion cleanability, printability, and stability over time. Comparative Example 2 did not contain inorganic fine particles, and therefore had poor fine line reproducibility and immersion cleanability. On the other hand, Examples contained an aqueous resin having an acidic group and inorganic fine particles, and therefore had good fine line reproducibility, immersion cleanability, printability, and stability over time.

[0108] Although the present invention has been described with reference to the above-mentioned several embodiments, the present invention is not limited to these several embodiments. Various modifications can be made to the configuration and details of the present invention within the scope of the present invention.

[0109] The disclosure of this application is related to the subject matter described in Japanese Patent Application No. 2023-218790 filed on December 26, 2023 and the subject matter described in Japanese Patent Application No. 2024-165463 filed on September 24, 2024, the entire disclosures of which are incorporated herein by reference.

[0110] 1 substrate, 2 pattern coating layer, 3 electrode layer, 4 laminate

Claims

1. A coating agent for a lift-off process including a pattern formation process not relying on exposure, the coating agent including an aqueous resin having an acidic group and inorganic fine particles.

2. The coating agent according to claim 1, wherein the aqueous resin having an acidic group includes at least one selected from the group consisting of a polyvinyl alcohol-based resin (A) having an acidic group and a polysaccharide-based resin having an acidic group.

3. The coating agent according to claim 1, wherein the content of the inorganic fine particles is 3 to 20% by mass in 100% by mass of the coating agent.

4. The coating agent according to claim 1 or 2, which is for gravure printing or flexographic printing.

5. The coating agent according to claim 1 or 2, further including an aqueous resin having no acidic group.

6. The coating agent according to claim 5, wherein the mass ratio of the aqueous resin having an acidic group to the aqueous resin having no acidic group is 9:1 to 1:

9.

7. The coating agent according to claim 1 or 2, wherein the inorganic fine particles are at least one selected from the group consisting of calcium carbonate, barium sulfate, magnesium carbonate, silica, titanium oxide, talc, montmorillonite, kaolin, and mica.

8. The coating agent according to claim 1 or 2, wherein the average particle diameter of the inorganic fine particles by the laser scattering method is 5 μm or less.

9. The coating agent according to claim 1 or 2, wherein the mass ratio of the aqueous resin having an acidic group to the inorganic fine particles is 1:0.2 to 1:

3.

10. The coating agent according to claim 1 or 2, further including an alcohol-based organic solvent.

11. The coating agent according to claim 10, wherein the alcohol-based organic solvent is at least one selected from the group consisting of methanol, ethanol, isopropanol, and n-propanol.

12. The coating agent according to claim 1 or 2, wherein the viscosity at 25 °C and a solid content of 18% by mass measured according to JIS K 7117-1 is 20 to 450 mPa·s.

13. The coating agent according to claim 1 or 2, wherein the pH of the extracted water of the inorganic fine particles measured by the following measurement method is 7.5 to 14.

0. (Measurement method) Mix 5 parts of inorganic fine particles and 100 parts of ion-exchanged water, boil for 5 minutes, stir for 30 minutes, and measure the pH of the supernatant water with a pH meter in accordance with JIS Z 8802.

14. A step of printing a lift-off coating agent containing an aqueous resin having an acidic group and inorganic fine particles on a part of a substrate to form a patterned coating layer without exposure; a step of obtaining a laminate (C) having the coating layer and the electrode layer on the substrate by forming an electrode layer on the substrate and on the coating layer; and a step of obtaining a laminate (D) having a patterned electrode layer on the substrate by immersing the laminate (C) having the coating layer and the electrode layer on the substrate in a coating layer removing liquid to remove the coating layer. A method for manufacturing a laminate, comprising these steps.

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