Image recording method

Abstract

An image recording method includes a step of imparting a conductive ink to a substrate by an inkjet recording method, and a step of forming a conductive layer by irradiating the conductive ink imparted to the substrate with ultraviolet rays, the content of a liquid component of the conductive ink at the point of time when the irradiation of the ultraviolet rays is started being 5% by mass or more relative to the content of the liquid component of the conductive ink at the point of time when imparted to the substrate.

Description

Technical Field

[0001] This invention relates to an image recording method. Background Technology

[0002] Sometimes, electromagnetic noise, electrostatic noise, and other noises become problems for printed circuit boards. Previously, methods were known to form conductive layers by thermal sintering silver particle ink.

[0003] For example, Japanese Patent Application Publication No. 2014-529875 discloses a method for producing a conductive network of sintered silver, comprising: (a) preparing a conductive ink containing a silver compound and a binder; (b) depositing the conductive ink on a substrate and drying the deposited conductive ink by irradiation with an external energy source; and (c) irradiating the dried conductive ink with an external energy source to decompose the silver compound into silver elements, and sintering the silver elements to form a conductive network. Furthermore, US Patent No. 10,597,547 discloses an ink composition containing a silver complex.

[0004] Furthermore, International Publication No. 2020 / 094583 discloses a method for manufacturing a semiconductor package that is at least partially covered by a battery interference shielding layer. Summary of the Invention

[0005] The technical problem to be solved by the invention

[0006] When using conductive inks to form images on a substrate, higher image quality is required.

[0007] The present invention was made in view of the above circumstances, and one embodiment of the present invention aims to solve the problem of providing an image recording method capable of recording high-quality images.

[0008] means for solving technical problems

[0009] The present invention includes the following methods.

[0010] <1> An image recording method includes: a step of applying conductive ink to a substrate using an inkjet recording method; and a step of irradiating the conductive ink applied to the substrate with ultraviolet light to form a conductive layer, wherein the content of the liquid component of the conductive ink at the start of ultraviolet irradiation is 5% by mass or more relative to the content of the liquid component of the conductive ink at the time of application to the substrate.

[0011] <2> According to the image recording method described in <1>, wherein,

[0012] Conductive inks contain metal salts or metal complexes.

[0013] <3> According to the image recording method described in <2>, wherein,

[0014] Metal complexes are metal complexes having a structure derived from at least one of the following groups: ammonium carbamate compounds, ammonium carbonate compounds, amines, and carboxylic acids having 8 to 20 carbon atoms.

[0015] The metal salt is a metal carboxylate.

[0016] <4> The image recording method according to any one of <1> to <3>, wherein,

[0017] The time from when the conductive ink falls onto the substrate to when UV irradiation begins is within 60 seconds.

[0018] <5> The image recording method according to any one of <1> to <4>, wherein,

[0019] The time from when the conductive ink falls onto the substrate to when the ultraviolet light irradiation begins is within 10 seconds.

[0020] <6> The image recording method according to any one of <1> to <5> performs one or more stacking processes, the stacking process including:

[0021] The process of applying conductive ink to a conductive layer using inkjet recording; and the process of further forming a conductive layer by irradiating the conductive ink applied to the conductive layer with ultraviolet light, wherein the average thickness of each conductive layer is set to 1.5 μm or less.

[0022] <7> According to the image recording method described in <6>, wherein,

[0023] Each time the conductive ink is applied, the ink is exposed to ultraviolet light.

[0024] <8> The image recording method according to any one of <1> to <7> includes the steps of applying insulating ink to a substrate using an inkjet recording method, a dispensing coating method, or a spraying method, and forming an insulating layer by curing the insulating ink.

[0025] The process of applying conductive ink is the process of applying conductive ink to an insulating layer.

[0026] <9> The image recording method according to any one of <1> to <8>, wherein,

[0027] Ultraviolet light is light with a peak wavelength below 400 nm.

[0028] <10> The image recording method according to any one of <1> to <9>, wherein,

[0029] The substrate is a substrate for printed circuit boards.

[0030] Invention Effects

[0031] According to one embodiment of the present invention, an image recording method capable of recording high-quality images is provided. Detailed Implementation

[0032] The image recording method of the present invention will now be described in detail.

[0033] In this specification, the numerical range indicated by “~” represents the range within which the values ​​recorded before and after “~” are included as the minimum and maximum values, respectively.

[0034] In the numerical ranges described in this specification, the upper or lower limit value recorded within a certain numerical range can be replaced with the upper or lower limit value of other numerical ranges described in different stages. Furthermore, in the numerical ranges described in this specification, the upper or lower limit value recorded within a certain numerical range can be replaced with the value shown in the embodiments.

[0035] In this specification, when a composition contains multiple substances corresponding to each component, unless otherwise specified, the amount of each component in the composition refers to the total amount of the multiple substances present in the composition.

[0036] In this specification, a combination of two or more preferred methods is a more preferred method.

[0037] In this specification, the term "process" includes not only independent processes, but also processes that can be clearly distinguished from other processes, as long as the intended purpose of the process can be achieved.

[0038] In this specification, "image" refers to the entire membrane, and "image recording" refers to the formation of an image (i.e., the membrane). Furthermore, the concept of "image" in this specification also includes solid images.

[0039] [Image recording method]

[0040] The image recording method of the present invention includes: a step of applying conductive ink to a substrate using an inkjet recording method; and a step of irradiating the conductive ink applied to the substrate with ultraviolet light to form a conductive layer, wherein the liquid component content of the conductive ink at the start of ultraviolet irradiation is 5% by mass or more relative to the liquid component content of the conductive ink at the time of application to the substrate. The image recording method of the present invention enables the recording of high-quality images. The reason for this can be inferred as follows.

[0041] In the image recording method of the present invention, the content of the liquid component of the conductive ink at the start of ultraviolet irradiation is 5% by mass or more relative to the content of the liquid component of the conductive ink at the time of application to the substrate. That is, in the image recording method of the present invention, ultraviolet light is irradiated while the liquid component of the conductive ink remains, causing the components contained in the conductive ink to sinter. Since sintering occurs before the conductive ink wets and diffuses, it is inferred that high-quality images can be recorded.

[0042] For example, Japanese Patent Publication No. 2014-529875 describes a method of heating conductive ink at 120°C or 130°C for 30 minutes and then irradiating it with ultraviolet light. The method described in Japanese Patent Publication No. 2014-529875 assumes that at the start of ultraviolet irradiation, almost no liquid components of the conductive ink remain.

[0043] Furthermore, U.S. Patent No. 10,597,547 describes an ink composition containing a silver complex, and while International Publication No. 2020 / 094,583 describes a method for manufacturing a semiconductor package that is at least partially covered by a battery interference shielding layer, it does not describe the content of the liquid component of the conductive ink at the point at which ultraviolet irradiation begins.

[0044] <Conductive Ink Application Process>

[0045] The image recording method of the present invention includes a step of applying conductive ink to a substrate using an inkjet recording method (hereinafter referred to as the "conductive ink application step").

[0046] (Substrate)

[0047] The material of the substrate is not particularly limited and can be selected according to the purpose. Specifically, substrate materials include polyimide, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycarbonate, polyurethane, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, acrylic resin, AS resin (acrylonitrile-butadiene-styrene resin), ABS resin (acrylonitrile-butadiene-styrene copolymer), triacetyl cellulose, polyamide, polyacetal, polyphenylene sulfide, polysulfone, epoxy resin, glass epoxy resin, melamine resin, phenolic resin, urea resin, alkyd resin, fluororesin, polylactic acid, and other synthetic resins; inorganic materials such as copper, steel, aluminum, silicon, sodium glass, alkali-free glass, and indium tin oxide (ITO); and paper types such as base paper, coated paper, coated paper, cast-coated paper, plastic-coated photographic paper, and synthetic paper. Furthermore, the substrate can be one layer or two or more layers. When there are two or more substrates, two or more substrates with different materials can be stacked.

[0048] The substrate is preferably in sheet or film form. The thickness of the substrate is preferably 20 μm to 2000 μm.

[0049] The substrate may have an ink-receiving layer, the thickness of which is preferably 1 μm to 20 μm. A thickness of 1 μm to 20 μm allows for more stable retention of the ink-receiving layer. The ink-receiving layer refers to a coating formed on the substrate to absorb and fix the ink.

[0050] Before applying conductive ink, the substrate can be pretreated. Examples of pretreatment methods include ozone treatment, plasma treatment, corona treatment, primer treatment, and roughening treatment.

[0051] The substrate can be a substrate for printed circuit boards. A printed circuit board can be manufactured by applying insulating ink (described later) to the substrate, forming an insulating layer, then applying conductive ink to the insulating layer, and recording an image as a wiring pattern. Furthermore, a printed circuit board can be manufactured by mounting electronic components such as chips on the substrate, applying insulating ink to the mounted electronic components, forming an insulating layer, and then applying conductive ink to the insulating layer to form a conductive layer.

[0052] Electromagnetic shielding components can be manufactured by applying insulating ink to a substrate, forming an insulating layer, then applying conductive ink to the insulating layer, and finally covering the entire surface of the insulating layer with the conductive layer.

[0053] (Inkjet recording method)

[0054] Inkjet recording methods can be any of the following: charge control method that uses electrostatic induction to eject ink; on-demand ejection method (pressure pulse method) that uses the vibration pressure of piezoelectric elements; acoustic inkjet method that converts electrical signals into sound beams and irradiates ink, and ejects ink using radiation pressure; and thermal inkjet method (Bubble jet) that forms bubbles by heating ink and uses the resulting pressure.

[0055] In particular, an inkjet recording method is one that can effectively utilize the method described in Japanese Patent Application Publication No. 54-59936 to cause a drastic volume change in ink subjected to heat energy, and eject ink from a nozzle by the force caused by this change in state.

[0056] Furthermore, regarding the inkjet recording method, one can refer to the method described in paragraphs 0093 to 0105 of Japanese Patent Application Publication No. 2003-306623.

[0057] Examples of inkjet heads used in inkjet recording methods include a shuttle method that uses a short serial head to scan and record along the width of the substrate, and a line method that uses recording elements arranged in a line corresponding to the entire area of ​​one side of the substrate.

[0058] In the online mode, patterns can be formed on the entire surface of the substrate by scanning the substrate in a direction that intersects with the arrangement direction of the recording elements, eliminating the need for a short-headed transport system such as a carriage.

[0059] Furthermore, the movement of the carriage and the complex scanning control of the substrate are no longer required. Since only the substrate moves, the recording speed can be increased significantly compared to the shuttle method.

[0060] The amount of insulating ink ejected from the inkjet head is preferably 1 pL (picoliter) to 100 pL, more preferably 3 pL to 80 pL, and even more preferably 3 pL to 20 pL.

[0061] (The temperature of the substrate when applying ink)

[0062] In the conductive ink application process, the temperature of the substrate during conductive ink application is preferably 20°C to 120°C, more preferably 28°C to 80°C. If the substrate temperature is 20°C to 120°C, the residual amount of the liquid component described later can be set to 5% by mass or more.

[0063] (Conductive ink)

[0064] In this invention, conductive ink refers to ink used to form a conductive layer with conductive properties. Conductivity refers to a volume resistivity of less than 10⁻⁶. 8 Properties of Ωcm. The conductive layer can be formed on the entire surface of the substrate or on a portion of the substrate. If formed on a portion of the substrate, it can be linear.

[0065] The conductive ink is an ink containing metal particles (hereinafter also called "metal particle ink"), preferably an ink containing metal complexes (hereinafter also called "metal complex ink") or an ink containing metal salts (hereinafter also called "metal salt ink"), and more preferably a metal salt ink or a metal complex ink.

[0066] <<Metal Particle Ink>>

[0067] Metal particle inks are, for example, ink compositions in which metal particles are dispersed in a dispersion medium.

[0068] -Metal particles-

[0069] Examples of metals constituting metal particles include base metals and noble metals. Examples of base metals include nickel, titanium, cobalt, copper, chromium, manganese, iron, zirconium, tin, tungsten, molybdenum, and vanadium. Examples of noble metals include gold, silver, platinum, palladium, iridium, osmium, ruthenium, rhodium, rhenium, and alloys containing these metals. From the viewpoint of electrical conductivity, the metal constituting the metal particles preferably includes at least one selected from the group consisting of silver, gold, platinum, nickel, palladium, and copper, and more preferably includes silver.

[0070] The average particle size of the metal particles is not particularly limited, but is preferably 10 nm to 500 nm, more preferably 10 nm to 200 nm. If the average particle size is within this range, the calcination temperature of the metal particles is reduced, and the processability of the conductive ink film is improved. In particular, when applying ink to the metal particles using a spraying or inkjet recording method, there is a tendency to improve ejectibility, pattern formation, and the uniformity of the conductive ink film thickness. The average particle size mentioned here refers to the average value of the primary particle size of the metal particles (average primary particle size).

[0071] The average particle size of the metal particles is measured by laser diffraction / scattering. The average particle size of the metal particles is, for example, a value obtained by measuring the 50% volume cumulative diameter (D50) three times and calculating the average of the three measurements. This value can be measured using a laser diffraction / scattering type particle size distribution measuring device (product name "LA-960", manufactured by HORIBA, Ltd.).

[0072] Furthermore, the metal particle ink can contain metal particles with an average particle size of 500 nm or more, as needed. When containing metal particles with an average particle size of 500 nm or more, the nm-sized metal particles can bond to the conductive ink film by lowering the melting point around the μm-sized metal particles.

[0073] In metallic particle inks, the content of metallic particles relative to the total amount of metallic particle ink is preferably 10% to 90% by mass, more preferably 20% to 50% by mass. If the content of metallic particles is 10% by mass or more, the surface resistivity is further reduced. If the content of metallic particles is 90% by mass or less, the ejectibility is improved when the metallic particle ink is applied using an inkjet recording method.

[0074] In addition to metal particles, metal particle inks may contain, for example, dispersants, resins, dispersion media, thickeners, and surface tension modifiers.

[0075] -Dispersant-

[0076] Metal particle inks may contain a dispersant that adheres to at least a portion of the surface of the metal particles. The dispersant essentially forms metal colloidal particles together with the metal particles. The dispersant has the function of coating the metal particles, thereby improving their dispersibility, and preventing aggregation. The dispersant is preferably an organic compound capable of forming metal colloidal particles. From the viewpoint of conductivity and dispersion stability, the dispersant is preferably an amine, carboxylic acid, alcohol, or resin dispersant.

[0077] The dispersant contained in the metal particle ink can be one type or two or more types.

[0078] Examples of amines include saturated or unsaturated aliphatic amines. Preferably, the amine is an aliphatic amine with 4 to 8 carbon atoms. Aliphatic amines with 4 to 8 carbon atoms can be linear or branched, and can have a cyclic structure.

[0079] Examples of aliphatic amines include butylamine, n-pentylamine, isopentylamine, hexylamine, 2-ethylhexylamine, and octylamine.

[0080] Examples of cycloalkylamines that are amines with an alicyclic structure include cyclopentylamine and cyclohexylamine.

[0081] Aniline is an example of an aromatic amine.

[0082] Amines can have functional groups other than amino groups. Examples of functional groups other than amino groups include hydroxyl, carboxyl, alkoxy, carbonyl, ester, and mercapto groups.

[0083] Examples of carboxylic acids include formic acid, oxalic acid, acetic acid, hexanoic acid, acrylic acid, octanoic acid, oleic acid, tartaric acid, ricinoleic acid, gallic acid, and salicylic acid. The carboxyl group, which is part of a carboxylic acid, can form a salt with a metal ion. The metal ion forming the salt can be one or more different metals.

[0084] Carboxylic acids can have functional groups other than the carboxyl group. Examples of functional groups other than the carboxyl group include amino, hydroxyl, alkoxy, carbonyl, ester, and mercapto groups.

[0085] Examples of alcohols include terpenoid alcohols, allyl alcohols, and oleyl alcohols. Alcohols readily coordinate with the surface of metal particles, thus inhibiting the aggregation of metal particles.

[0086] Examples of resin dispersants include those that have nonionic groups as hydrophilic groups and are uniformly soluble in solvents. Examples of resin dispersants include polyvinylpyrrolidone, polyethylene glycol, polyethylene glycol-polypropylene glycol copolymer, polyvinyl alcohol, polyallylamine, and polyvinyl alcohol-polyvinyl acetate copolymer. Regarding the molecular weight of the resin dispersant, the weight-average molecular weight is preferably 1000 to 50000, more preferably 1000 to 30000.

[0087] In metal particle inks, the content of dispersant relative to the total amount of metal particle ink is preferably 0.5% to 50% by mass, more preferably 1% to 30% by mass.

[0088] -Dispersion medium-

[0089] Metal particle inks preferably contain a dispersion medium. The type of dispersion medium is not particularly limited; for example, hydrocarbons, alcohols, and water can be included.

[0090] The dispersion medium contained in the metal particle ink can be one type or two or more types. Preferably, the dispersion medium contained in the metal particle ink is volatile. The boiling point of the dispersion medium is preferably 50℃ to 250℃, more preferably 70℃ to 220℃, and even more preferably 80℃ to 200℃. If the boiling point of the dispersion medium is 50℃ to 250℃, it tends to balance the stability and calcinability of the metal particle ink.

[0091] Examples of hydrocarbons include aliphatic hydrocarbons and aromatic hydrocarbons.

[0092] Examples of aliphatic hydrocarbons include, for example, tetradecane, octadecane, heptamethylnonane, tetramethylpentadecanane, hexane, heptane, octane, nonane, decane, tridecane, methylpentane, n-alkanes, isoalkanes, and other saturated or unsaturated aliphatic hydrocarbons.

[0093] Examples of aromatic hydrocarbons include, for example, toluene and xylene.

[0094] Examples of alcohols include aliphatic alcohols and alicyclic alcohols. When an alcohol is used as a dispersion medium, an amine or carboxylic acid is preferred as the dispersant.

[0095] Examples of aliphatic alcohols include, for instance, aliphatic alcohols with 6 to 20 carbon atoms that contain ether bonds in saturated or unsaturated chains such as heptanol, octanol (e.g., 1-octanol, 2-octanol, 3-octanol, etc.), decanol (e.g., 1-decanol, etc.), lauryl alcohol, tetradecyl alcohol, hexadecyl alcohol, 2-ethyl-1-hexanol, octadecanol, hexadecyl alcohol, oleyl alcohol, etc.

[0096] Examples of alicyclic alcohols include, for example, cycloalkanols such as cyclohexanol; terpenols (including α, β, γ isomers or any mixture thereof), dihydroterpenols such as dihydroterpenol; hydrogenated terpenols, myrtol, menthol, carvyl alcohol, perillyl alcohol, rosinol, sobryl alcohol, and verbenol.

[0097] The dispersion medium can be water. From the viewpoint of adjusting physical properties such as viscosity, surface tension, and volatility, the dispersion medium can be a mixture of water and other solvents. Alcohols are preferably the other solvents mixed with water. The alcohol used simultaneously with water is preferably an alcohol with a boiling point below 130°C that is miscible with water. Examples of alcohols include 1-propanol, 2-propanol, 1-butanol, 2-butanol, tert-butanol, 1-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and propylene glycol monomethyl ether.

[0098] In metallic particle inks, the content of the dispersion medium relative to the total amount of metallic particle ink is preferably 1% to 50% by mass. If the content of the dispersion medium is 1% to 50% by mass, sufficient conductivity can be obtained as a conductive ink. More preferably, the content of the dispersion medium is 10% to 45% by mass, and even more preferably 20% to 40% by mass.

[0099] -Resin-

[0100] Metal particle inks may contain resins. Examples of resins include polyester, polyurethane, melamine resin, acrylic resin, styrene resin, polyether and terpene resin.

[0101] The resin contained in the metal particle ink can be one type or two or more types.

[0102] In metal particle inks, the resin content relative to the total amount of metal particle ink is preferably 0.1% to 5% by mass.

[0103] -Thickener-

[0104] Metal particle inks may contain thickeners. Examples of thickeners include clay minerals such as clay, bentonite, and lithium montmorillonite; cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose; and polysaccharides such as xanthan gum and guar gum.

[0105] The thickener contained in the metal particle ink can be one type or two or more types.

[0106] In metallic particle inks, the content of thickener relative to the total amount of metallic particle ink is preferably 0.1% to 5% by mass.

[0107] -surfactant-

[0108] Metal particle inks can contain surfactants. If a metal particle ink contains a surfactant, it is easier to form a uniform conductive ink film.

[0109] The surfactant can be any of anionic, cationic, or nonionic surfactants. From the viewpoint of being able to adjust surface tension with a small amount, a fluorinated surfactant is preferred. Furthermore, the surfactant is preferably a compound with a boiling point exceeding 250°C.

[0110] The viscosity of the metal particle ink is not particularly limited, as long as it is between 0.01 Pa·s and 5000 Pa·s, preferably between 0.1 Pa·s and 100 Pa·s. When the metal particle ink is applied by spraying or inkjet recording, the viscosity of the metal particle ink is preferably between 1 mPa·s and 100 mPa·s, more preferably between 2 mPa·s and 50 mPa·s, and even more preferably between 3 mPa·s and 30 mPa·s.

[0111] The viscosity of metallic particle ink is measured using a viscometer at 25°C. For example, the viscosity is measured using a VISCOMETER TV-22 viscometer (manufactured by TOKI SANGYO CO.,LTD.).

[0112] The surface tension of the metal particle ink is not particularly limited, but is preferably 20mN / m to 45mN / m, and more preferably 25mN / m to 40mN / m.

[0113] The surface tension is the value measured using a surface tension meter at 25°C.

[0114] For example, the DY-700 (manufactured by Kyowa Interface Science Co., Ltd.) is used to measure the surface tension of metallic particle inks.

[0115] -Methods for manufacturing metal particles-

[0116] Metal particles can be commercially available products or manufactured using known methods. Examples of methods for manufacturing metal particles include wet reduction, gas-phase methods, and plasma methods. A preferred method for manufacturing metal particles is the wet reduction method, which can produce metal particles with an average particle size of 200 nm or less with a narrow particle size distribution. Regarding methods for manufacturing metal particles based on the wet reduction method, examples include: a process of mixing a metal salt and a reducing agent as described in Japanese Patent Application Publication No. 2017-37761, International Publication No. 2014-57633, etc., to obtain a complexing reaction solution; and a process of reducing the metal ions in the complexing reaction solution by heating it to obtain a slurry of metal nanoparticles.

[0117] In the manufacturing process of metallic particle ink, heat treatment can be performed to adjust the content of each component in the ink to a specified range. Heat treatment can be performed under reduced pressure or at atmospheric pressure. Furthermore, if performed at atmospheric pressure, it can be carried out in the atmosphere or in an inert gas atmosphere.

[0118] <<Metal Complex Ink>>

[0119] Metal complex inks are, for example, ink compositions obtained by dissolving metal complexes in a solvent.

[0120] -Metal complex-

[0121] Examples of metals constituting a metal complex include silver, gold, aluminum, magnesium, tungsten, molybdenum, zinc, nickel, iron, platinum, tin, copper, and lead. From the viewpoint of electrical conductivity, the metal constituting the metal complex preferably includes at least one selected from the group consisting of silver, gold, platinum, nickel, palladium, and copper, and more preferably includes silver.

[0122] The metal content in the metal complex ink, relative to the total amount of the metal complex ink, is preferably 1% to 40% by mass, more preferably 5% to 30% by mass, and even more preferably 7% to 20% by mass, calculated in terms of metal elements.

[0123] Metal complexes are obtained, for example, by reacting a metal salt with a complexing agent. As a method for producing metal complexes, one example is adding the metal salt and the complexing agent to an organic solvent and stirring for a specified time. The stirring method is not particularly limited, and can be appropriately selected from known methods such as stirring with a stirring rod, stirring blades, or a mixer, or applying ultrasound.

[0124] Examples of metal salts include metal oxides, thiocyanates, sulfides, chlorides, cyanides, nitrites, carbonates, acetates, nitrates, nitrites, sulfates, phosphates, perchlorates, tetrafluoroborates, acetylacetone salts, and carboxylates.

[0125] Examples of complexing agents include amines, ammonium carbamate compounds, ammonium carbonate compounds, ammonium bicarbonate compounds, and carboxylic acids. From the viewpoint of conductivity and the stability of the metal complex, the complexing agent is preferably composed of at least one selected from the group consisting of ammonium carbamate compounds, ammonium carbonate compounds, amines, and carboxylic acids having 8 to 20 carbon atoms.

[0126] The metal complex is preferably a metal complex having a structure derived from a complexing agent and having at least one structure derived from the group consisting of ammonium carbamate compounds, ammonium carbonate compounds, amines, and carboxylic acids having 8 to 20 carbon atoms.

[0127] Amines that can act as complexing agents include, for example, ammonia, primary amines, secondary amines, tertiary amines, and polyamines.

[0128] Examples of primary amines having a straight-chain alkyl group include methylamine, ethylamine, 1-propylamine, n-butylamine, n-pentylamine, n-hexylamine, heptamine, octylamine, nonylamine, n-decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptylamine, and octadecylamine.

[0129] Examples of primary amines having branched alkyl groups include isopropylamine, sec-butylamine, tert-butylamine, isopentylamine, 2-ethylhexylamine, and tert-octylamine.

[0130] Examples of primary amines with an alicyclic structure include cyclohexylamine and dicyclohexylamine.

[0131] Examples of primary amines having a hydroxyalkyl group include ethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, propanolamine, isopropanolamine, dipropanolamine, diisopropanolamine, tripropanolamine, and triisopropanolamine.

[0132] Examples of primary amines with aromatic rings include benzylamine, N,N-dimethylbenzylamine, phenylamine, diphenylamine, triphenylamine, aniline, N,N-dimethylaniline, N,N-dimethyl-p-toluidine, 4-aminopyridine, and 4-dimethylaminopyridine.

[0133] Examples of secondary amines include dimethylamine, diethylamine, dipropylamine, dibutylamine, diphenylamine, dicyclopentylamine, and methylbutylamine.

[0134] Examples of tertiary amines include trimethylamine, triethylamine, tripropylamine, and triphenylamine.

[0135] Examples of polyamines include, for example, ethylenediamine, 1,3-diaminopropane, diethylenetriamine, triethylenetetramine, tetramethylenepentamine, hexamethylenediamine, tetraethylenepentamine, and combinations thereof.

[0136] The amine is preferably an alkylamine, more preferably an alkylamine with 3 to 10 carbon atoms, and more preferably a primary alkylamine with 4 to 10 carbon atoms.

[0137] The amines that constitute the metal complex can be one type or two or more types.

[0138] When reacting a metal salt with an amine, the molar ratio of the amine to the metal salt is preferably 1 to 15 times, more preferably 1.5 to 6 times. If the ratio is within the above range, the complex formation reaction is complete, and a transparent solution is obtained.

[0139] Ammonium carbamate compounds that can act as complexing agents include ammonium carbamate, methyl carbamate, ethyl carbamate, 1-propylammonium-1-propylcarbamate, isopropylaminoisopropylcarbamate, butylaminobutylcarbamate, isobutylaminoisobutylcarbamate, pentylaminopentylcarbamate, hexylaminohexylcarbamate, heptylaminoheptylcarbamate, octylaminooctylcarbamate, 2-ethylhexylammonium-2-ethylhexylcarbamate, nonylaminononylcarbamate, and decylaminodecylcarbamate.

[0140] Ammonium carbonate compounds that can act as complexing agents include ammonium carbonate, methyl ammonium carbonate, ethyl ammonium carbonate, 1-propyl ammonium carbonate, isopropyl ammonium carbonate, butyl ammonium carbonate, isobutyl ammonium carbonate, pentyl ammonium carbonate, hexyl ammonium carbonate, heptyl ammonium carbonate, octyl ammonium carbonate, 2-ethylhexyl ammonium carbonate, nonyl ammonium carbonate, and decyl ammonium carbonate.

[0141] Ammonium bicarbonate compounds that can act as complexing agents include ammonium bicarbonate, methyl ammonium bicarbonate, ethyl ammonium bicarbonate, 1-propyl ammonium bicarbonate, isopropyl ammonium bicarbonate, butyl ammonium bicarbonate, isobutyl ammonium bicarbonate, pentyl ammonium bicarbonate, hexyl ammonium bicarbonate, heptyl ammonium bicarbonate, octyl ammonium bicarbonate, 2-ethylhexyl ammonium bicarbonate, nonyl ammonium bicarbonate, and decyl ammonium bicarbonate.

[0142] When a metal salt reacts with an ammonium carbamate compound, an ammonium carbonate compound, or an ammonium bicarbonate compound, the molar ratio of the ammonium carbamate compound, the ammonium carbonate compound, or the ammonium bicarbonate compound to the molar ratio of the metal salt is preferably 0.01 to 1, more preferably 0.05 to 0.6.

[0143] Examples of carboxylic acids that can act as complexing agents include, for example, lanolinic acid, tartaric acid, 2-ethylhexanoic acid, decadecanoic acid, neodecanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, palmitic acid, oleic acid, linoleic acid, and linolenic acid. Preferably, the carboxylic acid has 8 to 20 carbon atoms, and more preferably, it has 10 to 16 carbon atoms.

[0144] In metal complex inks, the content of the metal complex relative to the total amount of the metal complex ink is preferably 10% to 90% by mass, more preferably 10% to 40% by mass. If the content of the metal complex is 10% by mass or more, the surface resistivity is further reduced. If the content of the metal complex is 90% by mass or less, the ejectibility is improved when the metal complex ink is applied using an inkjet recording method.

[0145] -solvent-

[0146] Metal complex inks preferably contain a solvent. The solvent is not particularly limited as long as it can dissolve the components contained in the metal complex ink, such as metal complexes. From the viewpoint of ease of manufacture, the boiling point of the solvent is preferably 30°C to 300°C, more preferably 50°C to 200°C, and even more preferably 50°C to 150°C.

[0147] Regarding the solvent content in the metal complex ink, the concentration of metal ions in the metal complex (the amount of metal present as free ions in 1g of the metal complex) is preferably 0.01 mmol / g to 3.6 mmol / g, more preferably 0.05 mmol / g to 2 mmol / g. If the concentration of metal ions is within the above range, the metal complex ink exhibits excellent flowability and conductivity.

[0148] Examples of solvents include, for example, hydrocarbons, cyclic hydrocarbons, aromatic hydrocarbons, carbamates, alkenes, amides, ethers, esters, alcohols, terpenes, terpenes, thiols, thioethers, phosphine, and water. Metal complex inks may contain only one solvent or two or more.

[0149] The hydrocarbon is preferably a straight-chain or branched hydrocarbon with 6 to 20 carbon atoms. Examples of hydrocarbons include pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, octadecane, nonadecane, and eicosane.

[0150] The cyclic hydrocarbon is preferably a cyclic hydrocarbon with 6 to 20 carbon atoms. Examples of cyclic hydrocarbons include cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, and decahydronaphthalene.

[0151] Examples of aromatic hydrocarbons include benzene, toluene, xylene, and tetrahydronaphthalene.

[0152] Ethers can be any of straight-chain ethers, branched-chain ethers, and cyclic ethers. Examples of ethers include diethyl ether, dipropyl ether, dibutyl ether, methyl-tert-butyl ether, tetrahydrofuran, tetrahydropyran, dihydropyran, and 1,4-dioxane.

[0153] Alcohols can be any of the primary, secondary, and tertiary alcohols.

[0154] Examples of alcohols include ethanol, 1-propanol, 2-propanol, 1-methoxy-2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 1-hexanol, 2-hexanol, 3-hexanol, 1-octanol, 2-octanol, 3-octanol, tetrahydrofurfuryl alcohol, cyclopentanol, terpineol, decanol, isodecanol, lauryl alcohol, isolaryl alcohol, myristol, isomyristol, cetyl alcohol (cetyl alcohol), isochetol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, isoleyl alcohol, linoleyl alcohol, isoleyl alcohol, palmitol, isopaltol, eicosanol, and isoeicosanol.

[0155] Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0156] Examples of esters include methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, methoxybutyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, and 3-methoxybutyl acetate.

[0157] Terpenes are derived from (C5H8) n The composition represents hydrocarbons. Examples of terpenes include monoterpenes (C...). 10 H 16 ), sesquiterpenes (C 15 H 24 ) and diterpenes (C 20 H 32 Specifically, examples include α-pinene, β-pinene, dipentene, limonene, laurylene, allocarpine, aubergine, α-phellandrene, α-terpinene, γ-terpinene, and isoterpinene.

[0158] Examples of terpenes include, for example, laurylene, aubergine, geraniol, nerol, linalool, citronellol, citral, menthene, limonene, dipentene, isoterpinene, terpinene, phellandrene, fenestration, menthol, terpineol, menthene monool, isopreneol, azelaic acid, piperone, dihydrocarvone, carvone, pinene, pinene, baicalein, juniperene, carene, pinene, bornene, fenestration, camphene, and carvone.

[0159] -reducing agent-

[0160] Metal complex inks may contain reducing agents. If a reducing agent is present in a metal complex ink, it promotes the reduction of the metal complex to a metal.

[0161] Examples of reducing agents include boron hydride metal salts, aluminum hydride salts, amines, alcohols, organic acids, reducing sugars, sugar alcohols, sodium sulfite, hydrazine compounds, dextrin, hydroquinone, hydroxylamine, ethylene glycol, glutathione, and oxime compounds.

[0162] The reducing agent can be an oxime compound described in Japanese Patent Application Publication No. 2014-516463. Examples of oxime compounds include acetone oxime, cyclohexanone oxime, 2-butanone oxime, 2,3-butanedione monooxime, dimethylglyoxime, methyl acetoacetate monooxime, methyl pyruvate monooxime, benzaldehyde oxime, 1-indanone oxime, 2-adamantaneone oxime, 2-methylbenzamide oxime, 3-methylbenzamide oxime, 4-methylbenzamide oxime, 3-aminobenzamide oxime, 4-aminobenzamide oxime, acetophenone oxime, benzamide oxime, and tert-butylacetophenone oxime.

[0163] The reducing agent contained in the metal complex ink can be one type or two or more types.

[0164] The content of reducing agent in the metal complex ink is not particularly limited, but is preferably 0.1% to 20% by mass relative to the total amount of the metal complex ink, more preferably 0.3% to 10% by mass, and even more preferably 1% to 5% by mass.

[0165] -Resin-

[0166] Metal complex inks may contain resins. The presence of resins in metal complex inks improves their adhesion to the substrate.

[0167] Examples of resins include polyester, polyethylene, polypropylene, polyacetal, polyolefin, polycarbonate, polyamide, fluoropolymer, silicone resin, ethyl cellulose, hydroxyethyl cellulose, rosin, acrylic resin, polyvinyl chloride, polysulfone, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene resins, polyacrylonitrile, polysulfide, polyamide-imide, polyether, polyarylate, polyetheretherketone, polyurethane, epoxy resin, vinyl ester resin, phenolic resin, melamine resin, and urea resin.

[0168] The resin contained in the metal complex ink can be one type or two or more types.

[0169] -additive-

[0170] The metal complex ink may further contain inorganic salts, organic salts, inorganic oxides such as silicon dioxide, and additives such as surface conditioners, wetting agents, crosslinking agents, antioxidants, rust inhibitors, heat stabilizers, surfactants, plasticizers, curing agents, thickeners, and silane coupling agents, without impairing the effects of the present invention. The total content of additives in the metal complex ink is preferably 20% by mass or less relative to the total amount of the metal complex ink.

[0171] The viscosity of the metal complex ink is not particularly limited, as long as it is between 0.01 Pa·s and 5000 Pa·s, preferably between 0.1 Pa·s and 100 Pa·s. When the metal complex ink is applied by spraying or inkjet recording, the viscosity of the metal complex ink is preferably between 1 mPa·s and 100 mPa·s, more preferably between 2 mPa·s and 50 mPa·s, and even more preferably between 3 mPa·s and 30 mPa·s.

[0172] The viscosity of the metal complex ink is the value measured using a viscometer at 25°C. For example, the viscosity is measured using a VISCOMETER TV-22 viscometer (manufactured by TOKI SANGYO CO.,LTD.).

[0173] The surface tension of the metal complex ink is not particularly limited, but is preferably 20 mN / m to 45 mN / m, more preferably 25 mN / m to 35 mN / m. The surface tension is the value measured using a surface tension meter at 25°C.

[0174] The surface tension of metal complex inks can be measured, for example, using a DY-700 (manufactured by Kyowa Interface Science Co., Ltd.).

[0175] <<Metal Salt Ink>>

[0176] Metal salt inks are, for example, ink compositions obtained by dissolving metal salts in a solvent.

[0177] -Metal Salts-

[0178] Examples of metals constituting a metal salt include silver, gold, aluminum, magnesium, tungsten, molybdenum, zinc, nickel, iron, platinum, tin, copper, and lead. From the viewpoint of electrical conductivity, the metal constituting the metal salt preferably includes at least one selected from the group consisting of silver, gold, platinum, nickel, palladium, and copper, and more preferably includes silver.

[0179] The metal content in the metal salt ink, relative to the total amount of the metal salt ink, is preferably 1% to 40% by mass, more preferably 5% to 30% by mass, and even more preferably 7% to 20% by mass (calculated as metal elements).

[0180] The content of metal salt in the metal salt ink is preferably 10% to 90% by mass relative to the total amount of metal salt ink, more preferably 10% to 60% by mass. If the content of metal salt is 10% by mass or more, the surface resistivity is further reduced. If the content of metal salt is 90% by mass or less, the ejectibility is improved when the metal salt ink is applied using a spray method or an inkjet recording method.

[0181] Examples of metal salts include, for example, metal benzoates, halides, carbonates, citrates, iodides, nitrites, nitrates, acetates, phosphates, sulfates, sulfides, trifluoroacetates, and carboxylates. Furthermore, salts can be composed of two or more elements.

[0182] From the viewpoint of conductivity and storage stability, the metal salt is preferably a metal carboxylate. The carboxylic acid forming the carboxylate is preferably at least one selected from the group consisting of formic acid and carboxylic acids having 1 to 30 carbon atoms, more preferably a carboxylic acid having 8 to 20 carbon atoms, and even more preferably a fatty acid having 8 to 20 carbon atoms. The fatty acid can be linear or branched and may have substituents.

[0183] Examples of straight-chain fatty acids include acetic acid, propionic acid, butyric acid, valeric acid, valeric acid, hexanoic acid, heptanoic acid, icosanoic acid, oleic acid, caprylic acid, nonanoic acid, decanoic acid, caprylic acid, lanolinic acid, grapeseed acid, caprylic acid, geraniic acid, decadecanoic acid, and undecanoic acid.

[0184] Examples of branched-chain fatty acids include isobutyric acid, isovaleric acid, ethylhexanoic acid, neodecanoic acid, trimethylacetic acid, 2-methylvaleric acid, 3-methylpentanoic acid, 4-methylvaleric acid, 2,2-dimethylbutyric acid, 2,3-dimethylbutyric acid, 3,3-dimethylbutyric acid, and 2-ethylbutyric acid.

[0185] Examples of carboxylic acids with substituents include hexafluoroacetylacetonate, 3-hydroxybutyric acid, 2-methyl-3-hydroxybutyric acid, 3-methoxybutyric acid, acetone dicarboxylic acid, 3-hydroxyglutaric acid, 2-methyl-3-hydroxyglutaric acid, and 2,2,4,4-hydroxyglutaric acid.

[0186] Metal salts can be commercially available or manufactured using known methods. Silver salts, for example, are manufactured using the following methods.

[0187] First, a silver compound (e.g., silver acetate) serving as a silver source and formic acid or a fatty acid with 1 to 30 carbon atoms, in an organic solvent such as ethanol, are added. The mixture is stirred for a specified time using an ultrasonic stirrer, and the resulting precipitate is washed with ethanol and then decanted. All these steps can be performed at room temperature (25°C). The molar ratio of the silver compound to formic acid or the fatty acid with 1 to 30 carbon atoms is preferably 1:2 to 2:1, more preferably 1:1.

[0188] Metal salt inks may contain solvents, reducing agents, resins, and additives. The preferred methods for including solvents, reducing agents, resins, and additives are the same as those for inclusion in metal complex inks.

[0189] The viscosity of the metal salt ink is not particularly limited, as long as it is between 0.01 Pa·s and 5000 Pa·s, preferably between 0.1 Pa·s and 100 Pa·s. When the metal salt ink is applied by spraying or inkjet recording, the viscosity of the metal salt ink is preferably between 1 mPa·s and 100 mPa·s, more preferably between 2 mPa·s and 50 mPa·s, and even more preferably between 3 mPa·s and 30 mPa·s.

[0190] The viscosity of metal salt inks is measured using a viscometer at 25°C. For example, the viscosity can be measured using a VISCOMETER TV-22 viscometer (manufactured by TOKI SANGYO CO.,LTD.).

[0191] The surface tension of the metal salt ink is not particularly limited, but is preferably 20 mN / m to 45 mN / m, more preferably 25 mN / m to 35 mN / m. The surface tension is the value measured using a surface tension meter at 25°C.

[0192] The surface tension of metal salt inks can be measured, for example, using a DY-700 (manufactured by Kyowa Interface Science Co., Ltd.).

[0193] The conductive ink used in the image recording method of the present invention preferably contains a metal complex or a metal salt. The metal complex is a metal complex having a structure derived from at least one of the following groups: ammonium carbamate compounds, ammonium carbonate compounds, amines, and carboxylic acids having 8 to 20 carbon atoms. The metal salt is preferably a metal carboxylate salt.

[0194] <Conductive layer formation process>

[0195] The image recording method of the present invention includes a step of forming a conductive layer by irradiating conductive ink applied to a substrate with ultraviolet light (hereinafter referred to as the "conductive layer forming step").

[0196] In the image recording method of the present invention, the content of the liquid component of the conductive ink at the start of ultraviolet irradiation is 5% by mass or more relative to the content of the liquid component of the conductive ink at the time of application to the substrate. Hereinafter, the content of the liquid component of the conductive ink at the start of ultraviolet irradiation relative to the content of the liquid component of the conductive ink at the time of application to the substrate will be referred to as "liquid component residue".

[0197] In addition, as will be described later, in the case of multiple ultraviolet irradiations, the residual amount of liquid components is calculated as the average of the residual amount of liquid components at the start time of each ultraviolet irradiation.

[0198] The liquid component of conductive ink refers to the component that can evaporate through external factors such as heat and light. Examples of liquid components in conductive ink include water and organic solvents.

[0199] The residual liquid component is 5% by mass or more, preferably 20% by mass or more, and more preferably 50% by mass or more. If the residual liquid component is 5% by mass or more, it cures before the conductive ink wets and spreads, thus obtaining a high-quality image.

[0200] The upper limit for the residual amount of liquid components is not specifically limited, and the residual amount of liquid components can be 100% by mass.

[0201] The content of the liquid component in the conductive ink at the point of application to the substrate can be obtained by calculating the content of the liquid component contained in the conductive ink housed in the ink canister of the inkjet recording apparatus just before application to the substrate. The content of the liquid component in the conductive ink can be calculated, for example, by the following method.

[0202] First, take an arbitrary amount of conductive ink contained in the ink container and weigh it. Set the weighed value as A1. Next, heat the weighed conductive ink in an oven at 200°C for 60 minutes. Weigh the cured product obtained by heating. Set the weighed value as A2. The content X of the liquid component contained in the conductive ink is calculated using the following formula.

[0203] Liquid component content X (mass%) = {(A1-A2) / A1} × 100

[0204] Furthermore, the content of the liquid component of the conductive ink at the point when ultraviolet irradiation begins can be calculated, for example, by the following method.

[0205] First, inkjet paper (product name "Hasai", manufactured by FUJIFILM Corporation) was cut to the image size (2cm × 3cm) as a substrate, and the cut substrate was weighed. The value obtained by weighing is set as B1. The substrate was placed in the inkjet recording device, and conductive ink was jetted 1 million times at a jet volume of 10 pL under ambient temperature (23°C) without ultraviolet light. Within 3 seconds after the jetting ended, the substrate with conductive ink was weighed. The value obtained by weighing is set as B2. The amount of conductive ink Y applied to the substrate at the point in time is calculated using the following formula.

[0206] The amount of conductive ink applied to the substrate at any given time is Y = B2 - B1

[0207] Furthermore, as a substrate, a substrate actually used for image recording is cut to an arbitrary size, and the cut substrate is weighed. The value obtained by weighing is set as C1. The substrate is placed in an inkjet recording device, and conductive ink is jetted 1 million times at a jet volume of 10 pL under arbitrary temperature conditions without ultraviolet irradiation. After jetting, after an arbitrary time, the substrate with conductive ink is weighed. The value obtained by weighing is set as C2. After an arbitrary time, under ultraviolet irradiation, the amount of conductive ink Z at the time when ultraviolet irradiation begins is calculated by the following formula.

[0208] The amount of conductive ink at the start of ultraviolet irradiation is Z = C2 - C1.

[0209] The amount of liquid component reduction at the start of ultraviolet radiation irradiation is calculated using the following formula.

[0210] The reduction in liquid components = YZ

[0211] The residual amount of liquid components is calculated using the following formula.

[0212] Liquid component residual amount (mass%) = {(Y×X / 100)-(YZ)} / (Y×X / 100)×100

[0213] The peak wavelength of the ultraviolet light is preferably below 405 nm, more preferably below 400 nm, and even more preferably below 390 nm. The lower limit of the peak wavelength of the ultraviolet light is not particularly limited, for example, it is 200 nm.

[0214] If the peak wavelength of ultraviolet light is below 405nm, the conductivity of the obtained image will be improved.

[0215] The preferred exposure dose when irradiated with ultraviolet light is 0.1 J / cm. 2 ~1000J / cm 2 More preferably 0.5 J / cm 2 ~100J / cm 2 As will be described later, when subjected to multiple ultraviolet radiation exposures, the exposure amount refers to the total exposure amount (total exposure) across all exposures.

[0216] As light sources for ultraviolet (UV) irradiation, mercury lamps, gas lasers, and solid-state lasers are mainly used, with mercury lamps, metal halide lamps, and UV fluorescent lamps being the most well-known. Furthermore, UV-LEDs (light-emitting diodes) and UV-LDs (laser diodes) are expected to be used as UV irradiation light sources due to their small size, long lifespan, high efficiency, and low cost. Among these, metal halide lamps, high-pressure mercury lamps, medium-pressure mercury lamps, low-pressure mercury lamps, or UV-LEDs are preferred light sources for UV irradiation.

[0217] In the image recording method of the present invention, the time from the moment the conductive ink falls onto the substrate to the start of ultraviolet irradiation (hereinafter referred to as "time A") is preferably within 150 seconds, more preferably within 60 seconds, and even more preferably within 10 seconds. If time A is within 150 seconds, the image quality of the obtained image is improved because the conductive ink cures before it wets and diffuses. The lower limit of time A is not particularly limited, for example, it is 1 microsecond.

[0218] <Layering Process>

[0219] In the image recording method of the present invention, after applying conductive ink to a substrate, conductive ink can be further applied. Hereinafter, the layer formed by applying conductive ink once will be referred to as a "conductive layer", and the layer formed by applying conductive ink multiple times will also be referred to as the "conductive layer as a whole".

[0220] In the image recording method of the present invention, ultraviolet light can be irradiated after the conductive ink is applied to the substrate two or more times. Furthermore, in the image recording method of the present invention, after the conductive ink is applied to the substrate once, ultraviolet light is irradiated, and conductive ink is further applied to the formed conductive layer.

[0221] The image recording method of the present invention includes a step of applying conductive ink to a substrate and a step of irradiating the conductive ink applied to the substrate with ultraviolet light to form a conductive layer. In the image recording method of the present invention, it is preferable to perform one or more lamination steps, which include: a step of applying conductive ink to a conductive layer using an inkjet recording method; and a step of irradiating the conductive ink applied to the conductive layer with ultraviolet light to further form a conductive layer.

[0222] The overall thickness of the conductive layer can be increased by applying the conductive ink more times.

[0223] When applying conductive ink two or more times, the types of conductive ink can be the same or different, but from the viewpoint of manufacturing efficiency, it is preferable to use the same type. Same type of conductive ink means that the components and contents contained in the conductive ink are the same. Different types of conductive ink mean that at least one of the components and contents contained in the conductive ink is different.

[0224] The number of lamination steps is not particularly limited and can be adjusted appropriately according to the overall thickness of the desired conductive layer. From the viewpoint of conductivity, the overall thickness of the conductive layer is preferably 0.1 μm to 30 μm, more preferably 0.3 μm to 15 μm.

[0225] The overall thickness of the conductive layer was measured using a laser microscope (product name "VK-X1000", manufactured by KEYENCE CORPORATION).

[0226] The average thickness of each conductive layer is obtained by dividing the overall thickness of the conductive layer by the number of times the conductive layer is formed (i.e., the number of times the conductive ink is applied).

[0227] In the image recording method of the present invention, the average thickness of each conductive layer is preferably set to 1.5 μm or less, more preferably 1.2 μm or less.

[0228] If the average thickness of each conductive layer is set to less than 1.5 μm, the conductivity will be further improved.

[0229] In the lamination process, the following steps can be performed: after performing multiple steps of applying conductive ink to the conductive layer using inkjet recording, the conductive ink applied to the conductive layer is irradiated with ultraviolet light to further form a conductive layer.

[0230] From the viewpoints of image quality, conductivity, and adhesion, the lamination process preferably includes the following step: after performing one step of applying conductive ink to the conductive layer using inkjet recording, the conductive ink applied to the conductive layer is irradiated with ultraviolet light to further form a conductive layer. That is, it is preferable to perform ultraviolet irradiation each time the conductive ink is applied.

[0231] <Calcination Process>

[0232] The image recording method of the present invention may include a calcination process in which the conductive layer is calcined after being irradiated with ultraviolet light.

[0233] The calcination temperature is preferably below 250°C, more preferably 50°C to 200°C, and even more preferably 80°C to 150°C. Furthermore, the calcination time is preferably 1 minute to 120 minutes, more preferably 1 minute to 40 minutes. If the calcination temperature and calcination time are within the above ranges, the effects of heat-induced deformation of the substrate can be reduced.

[0234] In particular, when the conductive ink contains metal salts or metal particles, it is preferable to calcine the conductive layer after irradiation with ultraviolet light.

[0235] <Insulation layer formation process>

[0236] The image recording method of the present invention preferably includes a step of applying insulating ink to a substrate using an inkjet recording method, a dispensing coating method, or a spraying method, and forming an insulating layer by curing the insulating ink. Furthermore, the step of applying conductive ink is preferably a step of applying conductive ink to the insulating layer.

[0237] From the viewpoint of reducing the thickness of the insulating ink film formed by applying it in a single, small-volume spray, the preferred method for applying insulating ink is inkjet recording. Details of the inkjet recording method are as follows.

[0238] The method of curing insulating ink is not particularly limited; for example, the method of irradiating the insulating ink applied to the substrate with active energy rays can be cited.

[0239] Examples of active energy rays include ultraviolet light, visible light, and electron beams, with ultraviolet light (hereinafter also referred to as "UV") being preferred.

[0240] The peak wavelength of the ultraviolet light is preferably 200nm to 405nm, more preferably 250nm to 400nm, and even more preferably 300nm to 400nm.

[0241] The preferred exposure dose for irradiation with active energy rays is 100 mJ / cm. 2 ~5000mJ / cm 2More preferably 300 mJ / cm 2 ~1500mJ / cm 2 .

[0242] As light sources for ultraviolet (UV) irradiation, mercury lamps, gas lasers, and solid-state lasers are mainly used, with mercury lamps, metal halide lamps, and UV fluorescent lamps being the most well-known. Furthermore, UV-LEDs (light-emitting diodes) and UV-LDs (laser diodes) are expected to be used as UV irradiation light sources due to their small size, long lifespan, high efficiency, and low cost. Among these, metal halide lamps, high-pressure mercury lamps, medium-pressure mercury lamps, low-pressure mercury lamps, or UV-LEDs are preferred light sources for UV irradiation.

[0243] In the process of obtaining the insulating layer, in order to obtain an insulating layer of the desired thickness, it is preferable to repeat the process of applying insulating ink and irradiating with active energy rays more than twice.

[0244] The thickness of the insulating layer is preferably 5μm to 5000μm, and more preferably 10μm to 2000μm.

[0245] (Insulating ink)

[0246] In this invention, insulating ink refers to ink used to form an insulating layer with insulating properties. Insulation property refers to a volume resistivity of 10⁻⁶. 10 Properties above Ωcm.

[0247] The insulating ink preferably contains polymerizable monomers and polymerization initiators.

[0248] -polymerizable monomers-

[0249] A polymerizable monomer is a monomer having at least one polymerizable group in one molecule. The polymerizable group in a polymerizable monomer can be a cationic polymerizable group or a free radical polymerizable group; from the viewpoint of curability, a free radical polymerizable group is preferred. Furthermore, from the viewpoint of curability, it is preferred that the free radical polymerizable group be an olefinically unsaturated group.

[0250] In this invention, a monomer refers to a compound with a molecular weight of 1000 or less. Molecular weight can be calculated by the types and numbers of atoms that constitute the compound.

[0251] Polymerizable monomers can be monofunctional polymerizable monomers with one polymerizable group, or polyfunctional polymerizable monomers with two or more polymerizable groups.

[0252] Monofunctional polymerizable monomers are not particularly limited as long as they have one polymerizable group. From the viewpoint of curability, monofunctional polymerizable monomers are preferably monofunctional free radical polymerizable monomers, and more preferably monofunctional olefin unsaturated monomers.

[0253] Examples of monofunctional olefinic unsaturated monomers include, for example, monofunctional (meth)acrylates, monofunctional (meth)acrylamides, monofunctional aromatic vinyl compounds, monofunctional vinyl ethers, and monofunctional N-vinyl compounds.

[0254] Examples of monofunctional (meth)acrylates include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, tert-octyl (meth)acrylate, isoamyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate, 4-n-butyl(meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, borneol (meth)acrylate, and isoborneol (meth)acrylate. 2-Ethylhexyl diethylene glycol (meth)acrylate, butoxy (meth)acrylate, 2-chloroethyl (meth)acrylate, 4-bromobutyl (meth)acrylate, cyanoethyl (meth)acrylate, benzyl (meth)acrylate, butoxy (meth)acrylate, methyl butoxy (meth)acrylate, 3-methoxy (meth)acrylate, ethyl 2-(2-methoxyethoxy)(meth)acrylate, 2-(2-butoxyethoxy)ethyl (meth)acrylate, 2,2,2-tetrafluoro (meth)acrylate, 1H,1H,2H,2H-decyl perfluoro (meth)acrylate, 4-butylphenyl (meth)acrylate, phenyl (meth)acrylate, 2,4,5-Tetramethylphenyl(meth)acrylate, 4-chlorophenyl(meth)acrylate, 2-phenoxy(meth)acrylate methyl methacrylate, 2-phenoxy(meth)acrylate ethyl methacrylate, (meth)acrylate glycidyl acrylate, (meth)acrylate glycidyl oxybutyl acrylate, (meth)acrylate glycidyl oxyethyl acrylate, (meth)acrylate glycidyl oxypropyl acrylate, (meth)acrylate tetrahydrofurfuryl acrylate, 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 3-hydroxybutyl 4-Hydroxybutyl methacrylate, cyclic trimethylolpropane acetal (meth)acrylate, phenyl glycidyl ether (meth)acrylate, dimethylamino(meth)acrylate ethyl acrylate, diethylamino(meth)acrylate ethyl acrylate, dimethylamino(meth)acrylate propyl acrylate, diethylamino(meth)acrylate propyl acrylate, trimethoxysilyl(meth)acrylate propyl acrylate, trimethylsilyl(meth)acrylate propyl acrylate, polyoxyethylene monomethyl ether (meth)acrylate, polyoxyethylene (meth)acrylate, polyoxyethylene monoalkyl ether (meth)acrylate 2-Methacrylate, dipropylene glycol (meth)acrylate, polypropylene oxide monoalkyl ether (meth)acrylate, 2-methacryloyloxyethyl succinate, 2-methacryloyloxyhexahydrophthalate, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, ethoxydiethylene glycol (meth)acrylate, butoxydiethylene glycol (meth)acrylate, trifluoroethyl (meth)acrylate, perfluorooctyl ethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, ethylene oxide (EO) modified phenol (meth) Acrylates, EO-modified cresol (meth)acrylates, EO-modified nonylphenol (meth)acrylates, propylene oxide (PO)-modified nonylphenol (meth)acrylates, EO-modified 2-ethylhexyl (meth)acrylates, dicyclopentenyl (meth)acrylates, dicyclopentenoxyethyl (meth)acrylates, dicyclopentyl (meth)acrylates, (3-ethyl-3-oxetanemethyl (meth)acrylates), phenoxyethylene glycol (meth)acrylates, 2-carboxyethyl (meth)acrylates, and 2-(meth)acryloyloxyethyl succinate.

[0255] Examples of monofunctional (meth)acrylamides include (meth)acrylamide, N-methyl (meth)acrylamide, N-ethyl (meth)acrylamide, N-propyl (meth)acrylamide, N-n-butyl (meth)acrylamide, N-tert-butyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, and (meth)methacryloylmorpholine.

[0256] Examples of monofunctional aromatic vinyl compounds include, for example, styrene, dimethylstyrene, trimethylstyrene, isopropylstyrene, chloromethylstyrene, methoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, methyl vinyl benzoate, 3-methylstyrene, 4-methylstyrene, 3-ethylstyrene, 4-ethylstyrene, 3-propylstyrene, 4-propylstyrene, 3-butylstyrene, 4-butylstyrene, 3-hexylstyrene, 4-hexylstyrene, 3-octylstyrene, 4-octylstyrene, 3-(2-ethylhexyl)styrene, 4-(2-ethylhexyl)styrene, allylstyrene, isopropylstyrene, butenylstyrene, octenylstyrene, 4-tert-butoxycarbonylstyrene, and 4-tert-butoxystyrene.

[0257] Examples of monofunctional vinyl ethers include, for example, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, tert-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, cyclohexylmethyl vinyl ether, 4-methylcyclohexylmethyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether, methoxy polyethylene glycol vinyl ether, tetrahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexylmethyl vinyl ether, diethylene glycol monovinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether, chloroethoxyethyl vinyl ether, phenethyl vinyl ether, and phenoxy polyethylene glycol vinyl ether.

[0258] Examples of monofunctional N-vinyl compounds include, for example, N-vinyl-ε-caprolactam and N-vinylpyrrolidone.

[0259] Multifunctional polymerizable monomers are not particularly limited as long as they have two or more polymerizable groups. From the viewpoint of curability, multifunctional polymerizable monomers are preferably multifunctional free radical polymerizable monomers, and more preferably multifunctional olefin unsaturated monomers.

[0260] Examples of polyfunctional olefinic unsaturated monomers include, for example, polyfunctional (meth)acrylate compounds and polyfunctional vinyl ethers.

[0261] Examples of multifunctional (meth)acrylates include, for example, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, propylene glycol dimethacrylate, dipropylene glycol dimethacrylate, tripropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, butylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 3-methyl-1,5-pentanediol dimethacrylate, 1,6-hexanediol dimethacrylate, heptanediol dimethacrylate, EO-modified neopentyl glycol dimethacrylate, PO-modified neopentyl glycol dimethacrylate, EO-modified hexanediol dimethacrylate, PO-modified hexanediol dimethacrylate, and octyl glycol dimethacrylate. Ester, nonanediol di(meth)acrylate, decanediol di(meth)acrylate, dodecanediol di(meth)acrylate, glycerol di(meth)acrylate, pentaerythritol di(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, tricyclodecanediethanol di(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane EO addition tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tri(methacryloyloxyethoxytrimethylolpropane, glycerol polyglycidyl ether poly(meth)acrylate and tris(2-acryloyloxyethyl)isocyanurate.

[0262] Examples of multifunctional vinyl ethers include, for example, 1,4-butanediol divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediethanol divinyl ether, bisphenol A epoxy alkyl divinyl ether, bisphenol F epoxy alkyl divinyl ether, trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, and ditrimethylolpropane. Tetravinyl ether, trivinyl glycerol, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexavinyl ether, EO addition trimethylolpropane trivinyl ether, PO addition trimethylolpropane trivinyl ether, EO addition ditrimethylolpropane tetravinyl ether, PO addition ditrimethylolpropane tetravinyl ether, EO addition pentaerythritol tetravinyl ether, PO addition pentaerythritol tetravinyl ether, EO addition dipentaerythritol hexavinyl ether and PO addition dipentaerythritol hexavinyl ether.

[0263] The content of polymerizable monomers relative to the total amount of insulating ink is preferably 10% to 98% by mass, more preferably 50% to 98% by mass.

[0264] -Polymerization initiator-

[0265] Examples of polymerization initiators included in insulating inks include oxime compounds, alkylbenzene compounds, acylphosphine compounds, aromatic onium salt compounds, organic peroxides, thio compounds, hexaaryl diimidazole compounds, borate ester compounds, azadinium compounds, diaceticotinamide compounds, reactive ester compounds, compounds with carbon-halogen bonds, and alkylamines.

[0266] From the viewpoint of further improving conductivity, the polymerization initiator contained in the insulating ink is preferably selected from at least one of the group consisting of oxime compounds, alkyl phenyl ketone compounds and diocene compounds, more preferably alkyl phenyl ketone compounds, and even more preferably at least one of the group consisting of α-aminoalkylphenyl ketone compounds and benzyl ketal alkyl phenyl ketones.

[0267] The content of the polymerization initiator relative to the total amount of the insulating ink is preferably 0.5% to 20% by mass, more preferably 2% to 10% by mass.

[0268] In this invention, the insulating ink may contain components other than polymerization initiators and polymerizable monomers. Examples of such components include sensitizers, surfactants, and additives.

[0269] (Sensitizer)

[0270] Insulating inks may contain at least one sensitizer.

[0271] Examples of sensitizers include, for example, polynuclear aromatic compounds (e.g., pyrene, perylene, triphenylene, and 2-ethyl-9,10-dimethoxyanthracene), xanthones (e.g., fluorescein, eosin, erythrosine, rhodamine B, and rose red), anthocyanins (e.g., thiocyanocyanine and oxocyanocyanine), piracetins (e.g., piracetin and carbonylpiracetin), thiazide compounds (e.g., thiamethoxam, methylene blue, and toluidine blue), acridine compounds (e.g., acridine orange, chloroflavin, and acridine flavin), anthraquinones (e.g., anthraquinones), squaricine compounds (e.g., squaricine), coumarin compounds (e.g., 7-diethylamino-4-methylcoumarin), thioxanthone compounds (e.g., isopropylthioxanthone), and dihydrobenzothiazenone compounds (e.g., dihydrobenzothiazenone). Among these, thioxanthone compounds are preferred.

[0272] When the insulating ink contains a sensitizer, the content of the sensitizer is not particularly limited, but is preferably 1.0% to 15.0% by mass relative to the total amount of the insulating ink, more preferably 1.5% to 5.0% by mass.

[0273] (Chain transfer agent)

[0274] The ink used to form the insulating protective layer may contain at least one chain transfer agent.

[0275] From the perspective of improving the reactivity of photopolymerization, the chain transfer agent is preferably a polyfunctional thiol.

[0276] Examples of polyfunctional thiols include: aliphatic thiols such as hexane-1,6-dithiol, decane-1,10-dithiol, dimercaptodiethyl ether, and dimercaptodiethyl sulfide; aromatic thiols such as xylene dithiol, 4,4′-dimercaptodiphenyl sulfide, and 1,4-phenyldithiol.

[0277] Poly(thioglycolic acid esters) of polyols such as ethylene glycol bis(thioglycolic acid ester), polyethylene glycol bis(thioglycolic acid ester), propylene glycol bis(thioglycolic acid ester), glyceryl tri(thioglycolic acid ester), trimethylolethane tri(thioglycolic acid ester), trimethylolpropane tri(thioglycolic acid ester), pentaerythritol tetra(thioglycolic acid ester), and dipentaerythritol hexa(thioglycolic acid ester);

[0278] Poly(3-mercaptopropionate) compounds of polyols such as ethylene glycol bis(3-mercaptopropionate), polyethylene glycol bis(3-mercaptopropionate), propylene glycol bis(3-mercaptopropionate), glyceryl tri(3-mercaptopropionate), trimethylolethane tri(mercaptopropionate), trimethylolpropane tri(3-mercaptopropionate), pentaerythritol tetra(3-mercaptopropionate), and dipentaerythritol hexa(3-mercaptopropionate); and

[0279] Poly(mercaptobutyrates) such as 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, pentaerythritol tetra(3-mercaptobutyrate) ester, etc.

[0280] (surfactant)

[0281] Insulating inks may contain at least one surfactant.

[0282] Examples of surfactants include those described in Japanese Patent Application Publication Nos. 62-173463 and 62-183457. Furthermore, examples of surfactants include anionic surfactants such as dialkyl sulfosuccinates, alkylnaphthalene sulfonates, and fatty acid salts; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, ethylene glycol ethynylene, and polyoxyethylene-polyoxypropylene block copolymers; and cationic surfactants such as alkylamine salts and quaternary ammonium salts. Additionally, the surfactant can be a fluorinated surfactant or a polysiloxane surfactant.

[0283] When the insulating ink contains a surfactant, the surfactant content is preferably 1% by mass or less, more preferably 0.5% by mass or less, relative to the total amount of the insulating ink. The lower limit for the surfactant content is not particularly limited.

[0284] (Organic solvents)

[0285] Insulating inks may contain at least one organic solvent.

[0286] Examples of organic solvents include: ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether (PGME), dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, and other (poly)alkylene glycol monoalkyl ethers.

[0287] Ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol diethyl ether, tetraethylene glycol dimethyl ether, and other (poly)alkylene glycol dialkyl ethers;

[0288] Diethylene glycol acetate and other (poly)alkylene glycol acetates;

[0289] Ethylene glycol diacetate, propylene glycol diacetate, and other (poly)alkylene glycol diacetates;

[0290] Ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate and other (poly)alkylene glycol monoalkyl ether acetates, methyl ethyl ketone, cyclohexanone and other ketones;

[0291] Lactones such as γ-butyrolactone;

[0292] Esters such as ethyl acetate, propyl acetate, butyl acetate, 3-methoxybutyl acetate (MBA), methyl propionate, and ethyl propionate;

[0293] Tetrahydrofuran, dioxane, and other cyclic ethers; and

[0294] Amides such as dimethylformamide and dimethylacetamide.

[0295] When the insulating ink contains organic solvents, the content of organic solvents relative to the total amount of the insulating ink is preferably 70% by mass or less, more preferably 50% by mass or less. The lower limit of the content of organic solvents is not particularly limited.

[0296] (additive)

[0297] Insulating inks can contain additives such as co-sensitizers, UV absorbers, antioxidants, anti-fading agents, and alkaline compounds, as needed.

[0298] (physical properties)

[0299] From the viewpoint of improving jetting stability when applying inkjet recording, the pH of the insulating ink is preferably 7 to 10, more preferably 7.5 to 9.5. The pH is measured using a pH meter at 25°C, for example, using a pH meter (model "HM-31") manufactured by DKK-TOACORPORATION.

[0300] The viscosity of the insulating ink is preferably 0.5 mPa·s to 60 mPa·s, more preferably 2 mPa·s to 40 mPa·s. The viscosity is measured using a viscometer at 25°C, for example, using a TV-22 type viscometer manufactured by TOKI SANGYOCO.,LTD.

[0301] The surface tension of the insulating ink is preferably below 60 mN / m, more preferably 20 mN / m to 50 mN / m, and even more preferably 25 mN / m to 45 mN / m. The surface tension is measured using a surface tension meter at 25°C, for example, using an automatic surface tension meter (product name "CBVP-Z") manufactured by Kyowa Interface Science Co., Ltd., and measured by the plate method.

[0302] Example

[0303] The present invention will be described in more detail below through embodiments, but the present invention is not limited to the following embodiments as long as it does not depart from its spirit.

[0304] <Preparation of Insulating Ink 1>

[0305] The following ingredients were mixed and stirred for 20 minutes at 25°C and 5000 rpm using a mixer (product name "L4R", manufactured by Silverson Machines Ltd.) to obtain insulating ink 1.

[0306] • Omni. 379: 2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)-butane-1-one (product name "Omnirad 379", manufactured by IGM Resins BV)... 4.0% by mass

[0307] • ITX: 2-Isopropylthioxanthone (product name "SPEEDCURE ITX", manufactured by Lambson)... 2.0% by mass

[0308] • PEA: Ethyl phenoxyacrylate (manufactured by FUJIFILM Wako Pure Chemical Corporation) … 49.0% by mass

[0309] • NVC: N-vinylcaprolactam (manufactured by FUJIFILM Wako Pure Chemical Corporation)……22.0% by mass

[0310] • TMPTA: Trimethylolpropane triacrylate (manufactured by FUJIFILM Wako Pure Chemical Corporation) … 23.0% by mass

[0311] <Preparation of Conductive Ink 1>

[0312] 25.1 g of 1-propanol, 20 g of silver acetate, and 5 g of formic acid were added to a 300 mL three-necked flask and stirred for 20 minutes. The resulting silver salt precipitate was decanted three times with 1-propanol and washed. 14.4 g of 1-propylamine and 25.1 g of 1-propanol were added to the precipitate and stirred for 30 minutes. Then, 10 g of water was added and the mixture was stirred further to obtain a solution containing a silver complex. The solution was filtered using a PTFE (polytetrafluoroethylene) membrane filter with a pore size of 0.45 μm to obtain conductive ink 1.

[0313] <Preparation of Conductive Ink 2>

[0314] In a 300 mL three-necked flask, 46 g of water, 20.0 g of silver acetate, 20 g of ethylenediamine, and 20 g of pentylamine were added and stirred for 20 minutes. 4 g of formic acid was then added to the resulting solution, and the mixture was stirred for another 30 minutes to obtain a solution containing a silver complex. This solution was filtered using a PTFE (polytetrafluoroethylene) membrane filter with a pore size of 0.45 μm to obtain conductive ink 2.

[0315] <Preparation of Conductive Ink 3>

[0316] In conductive ink 1, conductive ink 3 was obtained by the same method as conductive ink 1, except that the type and amount of complexing agent and the type and amount of solvent were changed to the substances listed in Table 1.

[0317] <Preparation of Conductive Ink 4>

[0318] 30g of dehydrated oxalic acid was dissolved in 350mL of water to prepare an oxalic acid aqueous solution. 30g of silver nitrate was dissolved in 120mL of water to prepare a silver nitrate aqueous solution. The silver nitrate aqueous solution was added dropwise to the oxalic acid aqueous solution while stirring. After the reaction was complete, the silver oxalate precipitate was isolated separately. 18g of the isolated silver oxalate and 36.50g of ethanol were added to a 200mL three-necked flask. 36g of isopropanolamine was added dropwise to the obtained suspension over 10 minutes in a water bath. 12.5g of octylamine was added, and the mixture was stirred at room temperature (23°C) for 2 hours to obtain a solution containing a silver complex. 1.2g of polyvinylpyrrolidone was added to 98.8g of the complex solution. The solution was filtered using a PTFE (polytetrafluoroethylene) membrane filter with a pore size of 0.45μm to obtain conductive ink 4.

[0319] <Preparation of Conductive Ink 5 to Conductive Ink 7>

[0320] In conductive ink 4, conductive ink 5 to conductive ink 7 were obtained by the same method as conductive ink 4, except that the type and content of the metal salt before the formation of the complex, the type and content of the solvent, and the type of the reducing agent were changed to the substances listed in Table 1.

[0321] <Preparation of Conductive Ink 8>

[0322] 40 g of silver neodecanoate was added to a 200 mL three-necked flask. Then, 30.0 g of trimethylbenzene and 30.0 g of terpineol were added and stirred to obtain a solution containing silver salt. The solution was filtered using a PTFE (polytetrafluoroethylene) membrane filter with a pore size of 0.45 μm to obtain conductive ink 8.

[0323] <Preparation of Conductive Ink 9>

[0324] In a 200 mL three-necked flask, 25.0 g of silver neodecanoate, 35 g of xylene, and 30.0 g of terpineol were added and dissolved. Then, 10 g of tert-octylamine was added and the mixture was stirred to obtain a solution containing a silver complex. The reaction was carried out at room temperature (23 °C) for 2 hours to obtain a homogeneous solution. This solution was filtered using a PTFE (polytetrafluoroethylene) membrane filter with a pore size of 0.45 μm to obtain conductive ink 9.

[0325] <Preparation of Conductive Ink 10>

[0326] Conductive ink 10 was obtained using the same method as conductive ink 9, except that tert-octylamine in conductive ink 9 was replaced with pentanamine.

[0327] <Preparation of Conductive Ink 11>

[0328] Except for replacing 1g of tert-octylamine in conductive ink 9 with 0.5g of pentylamine and 0.5g of octylamine, conductive ink 11 was obtained using the same method as conductive ink 9.

[0329] <Preparation of Conductive Ink 12>

[0330] 26.14 g of isobutylammonium carbonate and 64.0 g of isopropanol were added to a 200 mL three-necked flask and dissolved. Then, 9.0 g of silver oxide was added, and the mixture was reacted at room temperature (23 °C) for 2 hours to obtain a homogeneous solution. Next, 1.29 g of 2-hydroxy-2-methylpropylamine was added and stirred to obtain a solution containing a silver complex. This solution was filtered using a PTFE (polytetrafluoroethylene) membrane filter with a pore size of 0.45 μm to obtain conductive ink 12.

[0331] <Preparation of Conductive Ink 13>

[0332] In conductive ink 3, conductive ink 13 was obtained in the same manner as conductive ink 3, except that the amounts of complexing agent and reducing agent were changed to the substances listed in Table 1.

[0333] <Preparation of Conductive Ink 14>

[0334] As a dispersant, solution a was prepared by dissolving 6.8 g of polyvinylpyrrolidone (weight-average molecular weight 3000, manufactured by Sigma-Aldrich) in 100 mL of water. Solution b was prepared by dissolving 50.00 g of silver nitrate in 200 mL of water. To the mixture obtained by mixing and stirring solutions a and b, 78.71 g of an 85% by mass N,N-diethylhydroxylamine aqueous solution was added dropwise at room temperature (23°C), followed by the slow addition of a solution containing 6.8 g of polyvinylpyrrolidone dissolved in 1000 mL of water at room temperature. The resulting suspension was passed through an ultrafiltration unit (Vivaflow50 manufactured by Sartorius Stedim Japan Co., Ltd., fractionated molecular weight: 100,000, number of units: 4), and purified water was allowed to flow through until approximately 5 L of permeate was extracted from the ultrafiltration unit, and purification was performed. The supply of purified water was stopped and the mixture was concentrated to obtain 30 g of silver particle dispersion 1. The solid content of the dispersion was 50% by mass, and the silver content in the solid component was measured by TG-DTA (differential thermal gravimetric analysis) (manufactured by Hitachi High-Tech Corporation, model: STA7000 series), yielding a result of 96.0% by mass. The obtained silver particle dispersion 1 was diluted 20 times with deionized water, and the volume average particle size of the silver particles was determined using an FPAR-1000 particle size analyzer (manufactured by Otsuka Electronics Co., Ltd.). The volume average particle size of silver particle dispersion 1 was 60 nm.

[0335] 2g of 2-propanol and 0.1g of OLFINE E-1010 (manufactured by Nissin Chemical Industry Co., Ltd.) as a surfactant were added to 10g of silver particle dispersion, and water was added until the silver concentration reached 40% by mass to obtain conductive ink 14.

[0336] Table 1 shows the types and contents (mass %) of each component contained in conductive inks 1 to 14. First, it describes the form of the metal compound contained in the conductive ink, namely, a metal complex, a metal salt, or metal particles. Furthermore, in the case of a metal complex, it also describes the type of metal salt and the type of complexing agent before the formation of the complex.

[0337] The detailed information for the abbreviations in Table 1 is as follows.

[0338] -Complexing agents-

[0339] PA: 1-Propylamine

[0340] EDA: Ethylenediamine

[0341] EA: Ethylamine

[0342] iPrOHA: Isopropanolamine

[0343] AA: Pentylamine

[0344] EtOHA: Ethanolamine

[0345] OA: Octylamine

[0346] 2HMPA: 2-Hydroxy-2-methylpropylamine

[0347] tOA: tert-octylamine

[0348] IBAC: Isobutylammonium carbonate

[0349] -solvent-

[0350] 1PrOH: 1-Propanol

[0351] H2O: water

[0352] MeOH: Methanol

[0353] EtOH: Ethanol

[0354] IPA: Isopropyl alcohol

[0355] TO: Terpineol

[0356] TMB: Trimethylbenzene

[0357] XL: Xylene

[0358] -reducing agent-

[0359] FA: Formic acid

[0360] -Resin-

[0361] PVP: Polyvinylpyrrolidone

[0362]

[0363] [Example 1]

[0364] -Preparation of Laminated Sample 1-

[0365] A polyimide film (product name "Kapton", manufactured by DU PONT-TORAY CO., LTD.) was prepared as the substrate. Insulating ink 1 was filled into the inkjet head (product name "SG1024", manufactured by FUJIFILM DIMATIX, INC.). Image recording conditions were set to a resolution of 1200 dpi (dots per inch) and an ejection volume of 10 pL per dot. A UV lamp-type irradiator (365nm LED, peak intensity 8 W / cm²) was prepared next to the inkjet head. 2 (Irradiation area 2×8cm, company internal product). The process of repeatedly recording images on the substrate while simultaneously exposing it was repeated resulted in a stereoscopic image with a width of 10cm, a length of 5cm, and a thickness of 100μm. This formed an insulating layer on the substrate.

[0366] The substrate to which the insulating layer is formed is preheated to 45°C. Conductive ink is sprayed from the insulating layer, and 5.0 seconds after the ink lands, at a rate of 4 W / cm². 2 The sample was irradiated with ultraviolet light for 10 seconds, and an image measuring 5 cm in width and 2.0 cm in length was recorded. After irradiation for 5.0 seconds following the point where conductive ink was ejected and landed, the ultraviolet irradiation process was repeated, and images were recorded. This process was repeated 8 times in the same area (lamination process), resulting in a laminate sample 1 with a conductive layer of 3.2 μm thickness and a metallic luster. The total ultraviolet exposure was 40 J / cm². 2 .

[0367] -Preparation of laminated sample 2-

[0368] Using the same method as that used to prepare laminate sample 1, a three-dimensional image with a width of 2.5 cm, a length of 2.5 cm, and a thickness of 100 μm was recorded on the substrate using insulating ink 1. This formed an insulating layer on the substrate.

[0369] As a line and space pattern image, a four-line image with a length of 5 cm was recorded instead of an image with a width of 5 cm and a length of 2.5 cm. A laminated sample 2, having a conductive layer with a metallic luster and a thickness of 3.2 μm, was obtained using the same method as that used for laminated sample 1. Furthermore, the L / S ratios for the line and space pattern images were set to 100 μm / 75 μm, 100 μm / 100 μm, 100 μm / 125 μm, and 100 μm / 150 μm. L refers to the line width, and S refers to the space width.

[0370] - Fabrication of laminated sample 3-

[0371] As a substrate, except for a substrate in which solder resist (PSR-4000AM02, TAIYO HOLDINGS CO.,LTD.) was pre-coated in a polyimide film (product name "Kapton", manufactured by DU PONT-TORAY CO.,LTD.), laminate sample 3 was prepared using the same method as laminate sample 1.

[0372] - Fabrication of laminated sample 4-

[0373] As a substrate, except for a substrate in which solder resist (PSR-4000AM02, TAIYO HOLDINGS CO.,LTD.) was pre-coated in a polyimide film (product name "Kapton", manufactured by DU PONT-TORAY CO.,LTD.), laminate sample 4 was prepared in the same manner as laminate sample 2.

[0374] - Fabrication of laminated sample 5-

[0375] As the substrate, a rectangular electronic component (manufactured by Spansion LLC) with a thickness of 1mm and a diameter of 1mm and insulated with epoxy molding compound (EMC) was prepared. The substrate was preheated to 45°C, and conductive ink was ejected from an inkjet printhead (product name "SG1024", manufactured by FUJIFILM DIMATIX, INC.) at a resolution of 1200 dpi (dots per inch) and a jetting volume of 10 pL per dot. 5.0 seconds after the conductive ink fell, an illumination of 4 W / cm² was applied. 2 Images measuring 1.2 cm wide and 1.4 cm long were recorded after irradiating with ultraviolet light for 10 seconds, in a manner similar to coating electronic components. The irradiation process was repeated 5.0 seconds after the conductive ink was ejected and landed, and images were recorded. This process was repeated 8 times in the same area (lamination process), resulting in sample 1 of a laminate with a conductive layer of 3.2 μm thickness and a metallic luster. The total ultraviolet exposure was 40 J / cm². 2 .

[0376] [Examples 2-7, Examples 9-13]

[0377] In Examples 2 to 7 and Examples 12 to 13, except that the type of conductive ink was changed to the substance listed in Table 2, laminated sample 1 to laminated sample 4 were prepared in the same way as in Example 1.

[0378] In Examples 9 to 11, except that the type of conductive ink was changed to the substance listed in Table 2 and the substrate on which the insulating layer was formed was preheated to 60°C, laminate samples 1 to 4 were prepared in the same manner as in Example 1.

[0379] [Examples 8 and 14]

[0380] In Example 8, the conductive ink 1 used in Example 1 was replaced with conductive ink 8. Furthermore, the substrate to which the insulating layer was formed was preheated to 60°C. Except for performing eight cycles of irradiation with ultraviolet light 5.0 seconds after the conductive ink was ejected and landed, and then heating in an oven at 160°C for 20 minutes 10 seconds after the end of ultraviolet irradiation, laminated sample 1 to laminated sample 4 were produced using the same method as in Example 1.

[0381] In Example 14, the conductive ink 1 used in Example 1 was replaced with conductive ink 14. Furthermore, except for the following steps: after irradiating with ultraviolet light 5.0 seconds after the point where the conductive ink was ejected and landed 8 times, and then heating in an oven at 160°C for 20 minutes 10 seconds after the end of ultraviolet irradiation, laminated sample 1 to laminated sample 4 were prepared using the same method as in Example 1.

[0382] [Examples 15-33, Comparative Examples 2-3]

[0383] In Examples 15 to 33, laminate samples 1 to 4 were prepared using the same method as in Example 1, except that the number of times the conductive ink was applied, the number of exposures, the type of light source, the total exposure, the time from the moment the conductive ink fell to the start of ultraviolet irradiation (referred to as "time until exposure" in the table), and the temperature of the substrate when the conductive ink was sprayed (referred to as "substrate temperature" in the table) were changed to the substances described in Table 2. For Examples 20 to 24, laminate sample 5 was also prepared. Furthermore, in Example 15, a metal halide lamp (product name "F300S-6SYSTEM(H-BULB)", manufactured by Heraeus Corporation, referred to as "MH" in the table) was used.

[0384] [Example 34]

[0385] In Example 34, the amount of conductive ink ejected was set to 20 pL, and the resolution in the scanning direction was set to 2400 dpi. Furthermore, except for performing two separate operations of irradiating with ultraviolet light 5.0 seconds after the conductive ink was ejected and landed, laminated samples 1 to 4 were prepared using the same method as in Example 1.

[0386] [Example 35]

[0387] In Example 35, conductive ink was continuously sprayed onto the insulating layer four times, and ultraviolet light was irradiated 5.0 seconds after the fourth conductive ink fell. Furthermore, except for continuously spraying conductive ink four times and irradiating ultraviolet light 5.0 seconds after the fourth (out of eight) conductive ink fell, laminated sample 1 to laminated sample 4 were prepared using the same method as in Example 1.

[0388] [Example 36]

[0389] In Example 36, except that conductive ink was sprayed onto the insulating layer and the conductive ink was sprayed eight times in succession, and ultraviolet light was irradiated 5.0 seconds after the point when the eighth conductive ink landed, laminated sample 1 to laminated sample 4 were prepared in the same way as in Example 1.

[0390] [Comparative Example 1]

[0391] In Comparative Example 1, laminated sample 1 to laminated sample 4 were prepared in the same manner as in Example 4, except that ultraviolet light was irradiated 1800 seconds after the conductive ink fell using a pulse generator (product name "SINTERON2000", manufactured by Xenon Corporation).

[0392] Laminate samples 1 to 5, obtained in each embodiment and comparative example, were used to evaluate image quality, conductivity, and adhesion properties. The measurement and evaluation methods are as follows. The measurement and evaluation results are shown in Table 2.

[0393] <Image Quality>

[0394] The conductive layers in laminated samples 2 and 4 were observed using a microscope (product name "VK-X1000 Laser Microscope", manufactured by KEYENCE CORPORATION) under a 5x objective lens. The preservation of space between lines was confirmed in the line and spatial pattern images, and image quality was evaluated. The evaluation criteria are as follows. The evaluation results are shown in Table 2.

[0395] 5: Space was preserved in widths of 75μm, 100μm, 125μm and 150μm.

[0396] 4: In a space width of 75μm, the space was not preserved, but in other space widths, the space was preserved.

[0397] 3: Space was not preserved in widths of 75μm and 100μm, but it was preserved in other widths.

[0398] 2: Space was not preserved in widths of 75μm, 100μm and 125μm, but it was preserved in width of 150μm.

[0399] 1: Space was not preserved in the space widths of 75μm, 100μm, 125μm and 150μm.

[0400] <Electrical Conductivity>

[0401] For each conductive layer in laminated sample 1 and laminated sample 3, the surface resistivity [Ω / □] was measured at room temperature (23°C) using a resistivity meter (product name "Lorester GP", manufactured by Mitsubishi Chemical Corporation) via a 4-terminal method. The evaluation criteria are as follows. Level 2 and above indicates a level that poses no problems in practical applications.

[0402] 5: Surface resistivity is less than 100 mΩ / □.

[0403] 4: Surface resistivity is above 100mΩ / □ and less than 250mΩ / □.

[0404] 3: The surface resistivity is above 250mΩ / □ and less than 500mΩ / □.

[0405] 2: The surface resistivity is above 500mΩ / □ and less than 1Ω / □.

[0406] 1: Surface resistivity is above 1Ω / □.

[0407] <Adhesion>

[0408] After fabricating laminated sample 1 and laminated sample 3, they were placed at 25°C for 1 hour. After 1 hour, transparent adhesive tape (registered trademark, No. 405, manufactured by NICHIBAN CO.,LTD., width 12 mm or less, also referred to as "tape") was attached to the conductive layer of laminated sample 1 and laminated sample 3. The adhesion between the insulating layer and the conductive layer was then evaluated by peeling the tape from an image.

[0409] The application and removal of tape are specifically carried out using the following methods.

[0410] The tape was removed at a constant speed and cut into pieces approximately 75mm in length, yielding tape sheets.

[0411] The obtained tape sheet was overlapped on the conductive layer of the laminate sample 1, and the central area of ​​the tape sheet, which is 12 mm wide and 25 mm long, was rubbed vigorously with the fingertip.

[0412] After applying the tape, hold one end of the tape and peel it off at an angle as close to 60° as possible for 0.5 to 1.0 seconds.

[0413] Visual inspection was conducted to check for any adhering substances in the peeled tape and to determine if the conductive layer in sample 1 of the laminate had been peeled off. The adhesion between the insulating and conductive layers was evaluated according to the following evaluation criteria. The evaluation criteria are as follows. The evaluation results are shown in Table 2.

[0414] 5: No attached material or conductive layer peeling was found on the tape.

[0415] 4: Some residue was found on the tape, but no peeling of the conductive layer was found.

[0416] 3: The following attachments were found on the tape, and some conductive layer peeling was also found, but this is within the range that is permissible in practical applications.

[0417] 2: Adhesive residue was found on the tape, and the conductive layer was also found to be peeled off, exceeding the allowable range in practical applications.

[0418] 1: Adhesive was found on the tape sheet, and the conductive layer was almost completely peeled off, revealing the insulating layer.

[0419] <Coating properties>

[0420] In laminated sample 5, the coating condition of the coated electronic components on the upper and side surfaces was observed using an optical microscope. Coating performance was evaluated based on the coating condition. The evaluation criteria are as follows: Level 3 and above indicates a level where there are no problems in practical applications. The evaluation results are shown in Table 3.

[0421] 3: All surfaces were coated.

[0422] 2: The top surface is coated, but there are uncoated parts on the sides.

[0423] 1: All surfaces have uncoated areas.

[0424] Table 2 records the type of conductive ink, the average thickness of each layer, the number of times the conductive ink was applied, the number of exposures, the type of light source, the substrate temperature during the application of the conductive ink, the exposure time until exposure, the total exposure amount, and the residual liquid component. Furthermore, the image quality evaluation results for sample 2 using the laminate were the same as those for sample 4 using the laminate. Additionally, the evaluation results for the conductivity and adhesion of sample 1 using the laminate were the same as those for sample 3 using the laminate.

[0425] [Table 2]

[0426]

[0427] As shown in Table 2, it can be seen that in Examples 1 to 36, since the process of applying conductive ink to a substrate using inkjet recording and the process of irradiating the aforementioned conductive ink applied to the substrate with ultraviolet light to form a conductive layer are included, and the content of the liquid component of the conductive ink at the start of ultraviolet irradiation is 5% by mass or more relative to the content of the liquid component of the conductive ink at the time of application to the substrate, a high-quality image can be obtained.

[0428] On the other hand, in Comparative Examples 1 to 3, since the liquid component content of the conductive ink at the start of ultraviolet irradiation is less than 5% by mass relative to the liquid component content of the conductive ink at the time of application to the substrate, the image quality of the obtained image is poor.

[0429] In Examples 1 to 13, it is known that the conductive ink contains metal salts or metal complexes. Compared with Example 14, which contains metal particles, the conductive ink has superior image quality, conductivity, and adhesion.

[0430] In Example 25, it is known that the time from when the conductive ink falls onto the substrate to the start of ultraviolet irradiation is within 60 seconds, and a higher image quality can be obtained compared to Example 26.

[0431] In Example 23, it is known that the time from when the conductive ink falls onto the substrate to the start of ultraviolet irradiation is within 10 seconds, and a higher image quality can be obtained compared to Example 24.

[0432] In Example 1, it is known that the average thickness of each conductive layer is less than 1.5 μm, which is superior to Example 34 in terms of image quality, conductivity and adhesion.

[0433] In Example 1, it is evident that since ultraviolet irradiation is performed each time the conductive ink is applied, the image quality, conductivity, and adhesion are superior compared to Examples 35 and 36.

[0434] In Example 1, it is known that the peak wavelength of the ultraviolet light is below 400nm, and the conductivity is excellent compared to Example 17.

[0435] [Table 3]

[0436]

[0437] As shown in Table 3, the coating properties are excellent in Examples 1, 20 to 24.

[0438] Additionally, the publication of U.S. Patent Application No. 63 / 105,913, filed October 27, 2020, is incorporated herein by reference in its entirety. Furthermore, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as those specifically and separately described and incorporated herein by reference.

Claims

1. An image recording method, comprising: The process of applying conductive ink to a substrate using inkjet recording; and The process of forming a conductive layer by irradiating the conductive ink applied to the substrate with ultraviolet light. The content of the liquid component of the conductive ink at the start of ultraviolet irradiation is 5% to 100% by mass relative to the content of the liquid component of the conductive ink at the time of application to the substrate. The time from when the conductive ink falls onto the substrate to when the ultraviolet irradiation begins is 1 microsecond to 150 seconds. The conductive ink contains a metal salt or a metal complex. The metal complex is a metal complex having a structure derived from at least one of the groups consisting of ammonium carbamate compounds, ammonium carbonate compounds, amines, and carboxylic acids having 8 to 20 carbon atoms. The metal salt is a metal carboxylate.

2. The image recording method according to claim 1, wherein, The time from when the conductive ink falls onto the substrate to when the ultraviolet light irradiation begins is 1 microsecond to 60 seconds.

3. The image recording method according to claim 1, wherein, The time from when the conductive ink falls onto the substrate to when the ultraviolet light irradiation begins is 1 microsecond to 10 seconds.

4. The image recording method according to any one of claims 1 to 3, wherein it performs one or more stacking processes, the stacking process comprising: The process of applying conductive ink onto the conductive layer using an inkjet recording method; and The process of further forming a conductive layer by irradiating the conductive ink applied to the conductive layer with ultraviolet light. The average thickness of the conductive layer in each layer is set to be less than 1.5 μm.

5. The image recording method according to claim 4, wherein, The ultraviolet light is applied each time the conductive ink is applied.

6. The image recording method according to any one of claims 1 to 3, comprising the steps of applying insulating ink to the substrate using an inkjet recording method, a dispensing coating method, or a spraying method, and forming an insulating layer by curing the insulating ink. The process of applying the conductive ink is the process of applying the conductive ink onto the insulating layer.

7. The image recording method according to any one of claims 1 to 3, wherein, The ultraviolet light is light with a peak wavelength of 200nm to 400nm.

8. The image recording method according to any one of claims 1 to 3, wherein, The substrate is a substrate for printed circuit boards.

Images