Laminate and method for manufacturing laminate

Abstract

The present invention provides: a laminate which is excellent in terms of adhesion after immersion in a plating solution; and a method for manufacturing the laminate. A laminate according to the present invention comprises: a base material; a metal oxide layer that contains a first metal atom which is selected from the group consisting of a titanium atom, a zirconium atom, and an aluminum atom; and a metal layer X that is disposed adjacent to the metal oxide layer and contains a second metal atom which is different from the first metal atom. The thickness of the metal oxide layer is 50-2,000 nm.

Description

Laminate and method for manufacturing laminate

[0001] The present invention relates to a laminate and a method for manufacturing the laminate.

[0002] A method for forming a conductive layer by applying a conductive ink containing a metal component onto a substrate using an inkjet recording method is widely known. As a laminate formed using the conductive ink used in such an inkjet recording method, Patent Document 1 discloses a substrate whose surface is treated with a predetermined coupling agent.

[0003] International Publication No. 2010 / 029934

[0004] The present inventors have studied the laminate described in Patent Document 1 and found that the metal layer is likely to peel off from the laminate when the laminate is immersed in a plating solution. Hereinafter, the fact that the metal layer is unlikely to peel off from the laminate when the laminate is immersed in a plating solution is also referred to as "excellent adhesion after immersion in a plating solution."

[0005] Therefore, an object of the present invention is to provide a laminate and a method for manufacturing the laminate that exhibits excellent adhesion after immersion in a plating solution.

[0006] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by the following configuration.

[0007] [1] A laminate comprising a substrate, a metal oxide layer containing first metal atoms selected from the group consisting of titanium atoms, zirconium atoms, and aluminum atoms, and a metal layer X disposed adjacent to the metal oxide layer and containing second metal atoms different from the first metal atoms, wherein the metal oxide layer has a thickness of 50 to 2000 nm. [2] The laminate according to [1], wherein the metal layer X contains silicon atoms. [3] The laminate according to [1] or [2], wherein the metal layer X contains silicon atoms, and the number of silicon atoms in the metal layer X is 0.1 to 10.0 atomic % relative to the total number of atoms in the metal layer X. [4] The laminate according to any one of [1] to [3], wherein the metal layer X contains silicon atoms, oxygen atoms, and carbon atoms, and the ratio of the number of silicon atoms to the total number of oxygen atoms and carbon atoms in the metal layer X is 0.25 or more. [5] The laminate according to any one of [1] to [4], wherein the thickness of the metal layer X is 0.1 to 3.0 μm. [6] The laminate according to any one of [1] to [5], wherein a metal layer Y containing a third metal atom different from both the first metal atom and the second metal atom is provided on the metal layer X. [7] A method for producing a laminate, comprising: Step 1: applying a composition containing a coupling agent selected from the group consisting of a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent onto a substrate to form a metal oxide layer containing a first metal atom selected from the group consisting of titanium atoms, zirconium atoms, and aluminum atoms; and Step 2: applying an ink containing a metal compound selected from the group consisting of a metal salt and a metal complex onto the metal oxide layer to form a metal layer X containing a second metal atom different from the first metal atom, wherein the thickness of the metal oxide layer is 50 to 2000 nm. [8] The method for producing a laminate according to [7], wherein the ink contains a silane coupling agent. [9] The method for producing a laminate according to [7] or [8], further comprising, after step 2, step 3 of plating the metal layer X to form a metal layer Y on the metal layer X, the metal layer Y including a third metal atom different from both the first metal atom and the second metal atom.

[0008] According to the present invention, it is possible to provide a laminate and a method for producing the laminate, which exhibit excellent adhesion after immersion in a plating solution.

[0009] The present invention will be described in detail below. The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the upper and lower limits. In the numerical ranges described in this specification, the upper or lower limit of a certain numerical range may be replaced with the upper or lower limit of another numerical range described in this specification. Furthermore, in the numerical ranges described in this specification, the upper or lower limit of a certain numerical range may be replaced with a value shown in the Examples. In this specification, each component may be a single substance corresponding to the component, or two or more substances may be used. When two or more substances are used for each component, the content of that component refers to the total content of the two or more substances, unless otherwise specified. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, the term "process" refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0010] [Laminate] The laminate includes a substrate, a metal oxide layer containing first metal atoms selected from the group consisting of titanium atoms, zirconium atoms, and aluminum atoms, and a metal layer X disposed adjacent to the metal oxide layer and containing second metal atoms different from the first metal atoms, wherein the thickness of the metal oxide layer is 50 to 2000 nm.

[0011] The reason why the laminate has excellent adhesion after immersion in a plating solution is unclear, but is presumed to be as follows. For example, when a laminate having a metal layer is plated to form a metal layer separate from the metal layer to increase the thickness of the metal layer, the metal layer may peel off from the laminate during the plating process. In contrast, the laminate of the present invention has a metal oxide layer containing first metal atoms arranged adjacent to the metal layer X, and the thickness of the metal oxide layer is within a specific range, so it is presumed that the metal layer X is less likely to peel off from the laminate.

[0012] Each of the components that the laminate may contain will be described in detail below.

[0013] <Substrate> The laminate includes a substrate. Examples of the material of the substrate include synthetic resins such as 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-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, and polylactic acid; inorganic materials such as copper, steel, aluminum, silicon, soda glass, alkali-free glass, and indium tin oxide (ITO); and papers such as base paper, art paper, coated paper, cast-coated paper, resin-coated paper, and synthetic paper. The substrate may be one layer or two or more layers. When the substrate has two or more layers, two or more substrates made of different materials may be laminated.

[0014] The substrate is preferably in the form of a sheet or film, and the thickness of the substrate is preferably 20 to 2000 μm.

[0015] The substrate may be surface-treated by known methods such as ozone treatment, plasma treatment, corona treatment, primer treatment, and roughening treatment.

[0016] <Metal Oxide Layer> The laminate includes a metal oxide layer having a thickness of 50 to 2000 nm, preferably 60 to 1000 nm, and more preferably 100 to 500 nm.

[0017] The metal oxide layer contains a first metal atom selected from the group consisting of titanium atoms, zirconium atoms, and aluminum atoms. The metal oxide layer preferably contains titanium atoms, as this provides better adhesion after immersion in a plating solution. The metal oxide layer also preferably contains an oxide of a first metal atom selected from the group consisting of titanium oxide, zirconium oxide, and aluminum oxide, and more preferably titanium oxide. As long as the metal oxide layer contains the first metal atom, it may also contain other metal atoms, or may contain two or more types of first metal atoms or other atoms.

[0018] In the metal oxide layer, the atomic number of the first metal atoms is preferably 80 to 100 atomic %, more preferably 90 to 100 atomic %, and even more preferably 99 to 100 atomic %, relative to the total number of metal atoms contained in the metal oxide layer. Furthermore, the content of the oxide of the first metal atoms is preferably 80 to 100 mass %, more preferably 90 to 100 mass %, and even more preferably 99 to 100 mass %, relative to the total mass of the metal oxide layer. The atomic number of the first metal atoms and the content of the oxide of the first metal atoms can be measured using, for example, an X-ray photoelectron spectrometer (XPS) and an X-ray fluorescence spectrometer (XRF).

[0019] <Metal Layer X> The laminate includes a metal layer X. The metal layer X is disposed adjacent to the metal oxide layer and includes a second metal atom of a different type from the first metal atom. "The metal layer X is disposed adjacent to the metal oxide layer" means that the metal layer X is disposed so as to be in contact with the metal oxide layer, and there is no other layer between the metal layer X and the metal oxide layer. The second metal atom is a different type from the first metal atom. The second metal atom may be a different type from the first metal atom selected from the group consisting of titanium atoms, zirconium atoms, and aluminum atoms. For example, when the first metal atom is a titanium atom, the second metal atom may be a metal atom other than a titanium atom, and may be a zirconium atom or an aluminum atom. Furthermore, it is preferable that the second metal atom be a different type from any of the metal atoms contained in the metal oxide layer. For example, when the metal oxide layer contains titanium atoms and zirconium atoms as the first metal atoms and indium atoms and tin atoms as the other metal atoms, it is preferable that the second metal atoms be of a type different from any of titanium atoms, zirconium atoms, indium atoms, and tin atoms.

[0020] Examples of the second metal atom include a silver atom, a copper atom, a gold atom, an aluminum atom, a magnesium atom, a tungsten atom, a molybdenum atom, a zinc atom, a nickel atom, a palladium atom, an iron atom, a platinum atom, a tin atom, and a lead atom. Among these, from the viewpoint of electrical conductivity, the second metal atom preferably contains at least one selected from the group consisting of a silver atom, a gold atom, a platinum atom, a nickel atom, a palladium atom, and a copper atom, more preferably contains at least one of a silver atom and a copper atom, and further preferably contains a silver atom.

[0021] The metal layer X preferably contains silicon atoms. When the metal layer X contains silicon atoms, the interaction with the metal oxide layer becomes stronger, resulting in better adhesion after immersion in a plating solution. In this specification, metalloid atoms such as boron atoms, silicon atoms, and germanium atoms are not included in the metal atoms.

[0022] The metal layer X preferably contains a second metal atom, a silicon atom, a carbon atom, and an oxygen atom. When the metal layer X contains a silicon atom, a carbon atom, and an oxygen atom, the silicon atom, the carbon atom, and the oxygen atom are preferably derived from the coupling agent used in Step 1 described below. In other words, the metal layer X preferably contains a second metal atom and a hydrolyzate or hydrolyzed condensate of the coupling agent. The coupling agent is the coupling agent used in Step 1 described below and is selected from the group consisting of titanium coupling agents, zirconium coupling agents, and aluminum coupling agents. The hydrolyzate of the coupling agent refers to a compound obtained by hydrolyzing the hydrolyzable groups in the coupling agent. The hydrolyzate may be one in which all of the hydrolyzable groups are hydrolyzed (complete hydrolyzate) or one in which only a portion of the hydrolyzable groups are hydrolyzed (partial hydrolyzate). In other words, the hydrolyzate may be a complete hydrolyzate, a partial hydrolyzate, or a mixture thereof. The hydrolyzed condensate of the coupling agent refers to a compound obtained by hydrolyzing the hydrolyzable groups in the coupling agent and condensing the resulting hydrolyzate. The hydrolysis condensate may be one in which all hydrolyzable groups are hydrolyzed and all of the hydrolyzates are condensed (complete hydrolysis condensate), or one in which some of the hydrolyzable groups are hydrolyzed and some of the hydrolyzates are condensed (partial hydrolysis condensate). That is, the hydrolysis condensate may be a complete hydrolysis condensate, a partial hydrolysis condensate, or a mixture thereof.

[0023] The atomic number of the second metal atoms is preferably 80 to 100 atomic %, more preferably 90 to 100 atomic %, and even more preferably 99 to 100 atomic %, relative to the total number of metal atoms contained in the metal layer X. The atomic number of the second metal atoms is preferably 30 to 99 atomic %, more preferably 50 to 95 atomic %, and even more preferably 60 to 95 atomic %, relative to the total number of atoms in the metal layer X. The atomic number of the second metal atoms can be measured, for example, by the measurement method for the first metal atoms described above.

[0024] The number of silicon atoms is preferably 0.1 to 20.0 atomic %, more preferably 0.1 to 10.0 atomic %, and even more preferably 0.1 to 7.0 atomic %, relative to the total number of atoms in the metal layer X. The number of carbon atoms is preferably 0 to 30.0 atomic %, more preferably 0.1 to 20.0 atomic %, and even more preferably 0.1 to 10.0 atomic %, relative to the total number of atoms in the metal layer X. The number of oxygen atoms is preferably 0 to 30.0 atomic %, more preferably 0.1 to 20.0 atomic %, and even more preferably 0.1 to 10.0 atomic %, relative to the total number of atoms in the metal layer X. The number of silicon atoms, the number of carbon atoms, and the number of oxygen atoms can be measured, for example, by the measurement method for the first metal atom described above.

[0025] When the metal layer X contains silicon atoms, oxygen atoms, and carbon atoms, the ratio of the number of silicon atoms to the total number of oxygen atoms and carbon atoms in the metal layer X (number of silicon atoms / total number of oxygen atoms and carbon atoms) is preferably 0.10 or more, and more preferably 0.25 or more in terms of excellent electrical conductivity and suppression of migration occurrence. The upper limit is preferably 0.90 or less, more preferably 0.70 or less.

[0026] The thickness of the metal layer X is preferably 0.1 to 5.0 μm, and more preferably 0.1 to 3.0 μm in terms of better adhesion after immersion in a plating solution.

[0027] <Metal Layer Y> The laminate may include a metal layer Y. The metal layer Y is disposed on the metal layer X and includes a third metal atom different from both the first metal atom and the second metal atom. The metal layer Y is preferably a metal layer formed in step 3 described below.

[0028] The third metal atom is a different type from the first metal atom and the second metal atom. The third metal atom may be any type as long as it is different from the first metal atom and the second metal atom. For example, when the first metal atom is a titanium atom and the second metal atom is a silver atom, the third metal atom is preferably a metal atom different from both titanium and silver atoms, i.e., the third metal atom is preferably a metal atom other than titanium and silver atoms. The third metal atom preferably includes at least one selected from the group consisting of gold atoms, silver atoms, copper atoms, platinum atoms, palladium atoms, nickel atoms, cobalt atoms, tin atoms, and iron atoms. Among these, in terms of conductivity, adhesion, and cost, the third metal atom is preferably a nickel atom, iron atom, or copper atom.

[0029] The metal layer Y may contain other atoms as long as it contains the third metal atom. Examples of the other atoms include atoms of various components that can be contained in the plating solution described below.

[0030] The number of atoms of the third metal atoms is preferably 80 to 100 atomic % of the total number of atoms in the metal layer Y, more preferably 90 to 100 atomic %, and even more preferably 99 to 100 atomic %.

[0031] The thickness of the metal layer Y is preferably 1 to 50 μm, more preferably 1 to 30 μm.

[0032] [Method for Producing Laminate] The method for producing the laminate is not particularly limited as long as it can produce the laminate described above. In particular, the method for producing the laminate includes the following steps: Step 1: applying a composition containing a coupling agent selected from the group consisting of a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent (hereinafter also referred to as the "specific coupling agent") to a substrate to form a metal oxide layer containing a first metal atom selected from the group consisting of titanium atoms, zirconium atoms, and aluminum atoms; and Step 2: applying an ink containing a metal compound selected from the group consisting of a metal salt and a metal complex to the metal oxide layer to form a metal layer X containing a second metal atom different from the first metal atom. The thickness of the metal oxide layer is preferably 50 to 2000 nm. When the metal layer X is formed from an ink containing a metal compound selected from the group consisting of a metal salt and a metal complex (particularly an ink containing the metal compound but not containing metal particles), the resulting metal layer X exhibits superior adhesion after immersion in a plating solution.

[0033] It is also preferable that the method for manufacturing the laminate further includes, after step 2, step 3 of plating the metal layer X to form a metal layer Y on the metal layer X, the metal layer Y including a third metal atom of a type different from both the first metal atom and the second metal atom.

[0034] <Step 1> Step 1 is a step of applying a composition containing a specific coupling agent onto a substrate to form a metal oxide layer containing a first metal atom selected from the group consisting of titanium atoms, zirconium atoms, and aluminum atoms. Step 1 allows the formation of a metal oxide layer on the substrate. It is preferable that the first metal atom contained in the metal oxide layer is a metal atom constituting the specific coupling agent contained in the composition. In other words, it is preferable that the first metal atom and the metal atom constituting the specific coupling agent are at least partially or entirely the same type of metal atom.

[0035] (Substrate) The substrate is the same as the substrate contained in the laminate, and the preferred embodiment is also the same.

[0036] (Composition) The composition contains a specific coupling agent. By using the specific coupling agent, it is possible to prevent the metal layer X from peeling off from the resulting laminate. The specific coupling agent preferably contains a titanium coupling agent.

[0037] Examples of titanium coupling agents include titanium tetraisopropoxide, titanium tetra-normal butoxide, titanium tetraoctoxide, titanium tetra-2-ethylhexoxide, titanium dioctyloxybis(octylene glycolate), tetramethyl titanate, titanium acetylacetonate, titanium diisopropoxybis(acetylacetonate), titanium tetraacetylacetonate, titanium diisopropoxybis(ethylacetoacetate), titanium ethylacetoacetate, titanium octanediolate, titanium diisopropoxybis(triethanolaminate), titanium triethanolaminate, titanium lactate ammonium salt, titanium lactate, polyhydroxytitanium stearate, and oligomers thereof. Among these, titanium coupling agents having tetravalent titanium are preferred, and titanium coupling agents having an alkoxy ligand having 3 to 10 carbon atoms and tetravalent titanium are more preferred. Examples of commercially available titanium coupling agents include KR38S, KR44, KR46B, KR55, KR9SA, KRTTS, KR41B, KR138S, KR238S, and KR338X (manufactured by Ajinomoto Fine-Techno Co., Inc.), Atron (NSi-500) manufactured by Nippon Soda Co., Ltd., and Orgathix TC-130, Orgathix PC-200, Orgathix PC-250, Orgathix PC-601, and Orgathix PC-620 manufactured by Matsumoto Fine Chemical Co., Ltd.

[0038] Examples of zirconia coupling agents include zirconium tetra-normal propoxide, zirconium tetra-normal butoxide, zirconium tetraacetylacetonate, zirconium tributoxy monoacetylacetonate, zirconium monobutoxy acetylacetonate bis(ethylacetoacetate), zirconium dibutoxy bis(ethylacetoacetate), zirconium tetraacetylacetonate, zirconium tributoxy monostearate, zirconium chloride compound aminocarboxylic acid, zirconium monoacetylacetonate, zirconium bisacetylacetonate, zirconium monoethylacetoacetate, zirconium acetylacetonate bisethylacetoacetate, zirconium acetate, zirconium monostearate, and their oligomers.Among these, as the zirconia coupling agent, the zirconia coupling agent having octavalent zirconia is preferred.

[0039] Examples of aluminum coupling agents include aluminum isopropylate, monosec-butoxyaluminum diisopropylate, aluminum sec-butylate, aluminum ethylate, ethylacetoacetate aluminum diisopropylate, aluminum tris(ethylacetoacetate), alkylacetoacetate aluminum diisopropylate, aluminum monoacetylacetonate bis(ethylacetoacetate), aluminum tris(acetylacetoacetate), aluminum bisethylacetoacetate monoacetylacetonate, and oligomers thereof.

[0040] The specific coupling agent may be used alone or in combination of two or more types. The content of the specific coupling agent is preferably 1 to 50 mass %, more preferably 2 to 40 mass %, based on the total solid content of the composition. In this specification, the "solid content" of the composition means the components that form a film formed using the composition. Typically, when the composition contains a solvent (e.g., an organic solvent and water), it means all components excluding the solvent. Furthermore, liquid components that form a film are also considered to be solid components.

[0041] The composition may include a solvent, such as hydrocarbons, cyclic hydrocarbons, aromatic hydrocarbons, carbamates, alkenes, amides, ethers, esters, alcohols, thiols, thioethers, phosphines, and water.

[0042] The hydrocarbon is preferably a linear or branched hydrocarbon having a carbon number of 6 to 20. Specific examples of the hydrocarbon include pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, octadecane, nonadecane, and icosane.

[0043] The cyclic hydrocarbon is preferably a cyclic hydrocarbon having a carbon number of 6 to 20. Specific examples of the cyclic hydrocarbon include cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, and decalin.

[0044] Specific examples of aromatic hydrocarbons include benzene, toluene, xylene, trimethylbenzene, and tetralin.

[0045] The ether may be a linear ether, a branched ether, or a cyclic ether. Specific examples of the ether include diethyl ether, dipropyl ether, dibutyl ether, methyl t-butyl ether, tetrahydrofuran, tetrahydropyran, dihydropyran, and 1,4-dioxane.

[0046] The alcohol may be any of a primary alcohol, a secondary alcohol, and a tertiary alcohol. Specific examples of the alcohol 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, isodecyl alcohol, lauryl alcohol, isolauryl alcohol, myristyl alcohol, isomyristyl alcohol, cetyl alcohol (cetanol), isocetyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, isooleyl alcohol, linolyl alcohol, isolinolyl alcohol, palmityl alcohol, isopalmityl alcohol, eicosyl alcohol, and isoeicosyl alcohol.

[0047] Specific examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0048] Specific 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.

[0049] (Procedure) Examples of methods for applying the composition include printing, spraying, roll coating, bar coating, curtain coating, spin coating, and die coating (slit coating). The coating film formed by applying the composition may be dried as needed. Examples of drying methods include natural drying and heat drying. Drying may also be performed under normal pressure or reduced pressure.

[0050] The thickness of the metal oxide layer is 50 to 2000 nm, preferably 60 to 1000 nm, and more preferably 100 to 500 nm.

[0051] <Step 2> Step 2 is a step of applying an ink containing a metal compound selected from the group consisting of metal salts and metal complexes onto the metal oxide layer to form a metal layer X containing second metal atoms of a different type from the first metal atoms.

[0052] The ink contains at least one of a metal complex and a metal salt. The ink preferably does not contain metal particles, as this provides excellent adhesion after immersion in a plating solution. Below, we will explain an ink containing a metal complex (hereinafter also referred to as a "metal complex ink") and an ink containing a metal salt (hereinafter also referred to as a "metal salt ink"). The ink preferably contains a second metal atom, and more preferably contains a metal compound containing the second metal atom. In other words, the ink is more preferably an ink containing a metal compound selected from the group consisting of metal salts and metal complexes and containing the second metal atom. The second metal atom is a metal atom of a different type from the first metal atom contained in the metal oxide layer formed in step 1. A preferred embodiment of the second metal atom is the second metal atom contained in the metal layer X described above.

[0053] (Metal Complex Ink) Metal complex ink is, for example, ink in which a metal complex is dissolved in a solvent.

[0054] -Metal Complex- Examples of metals constituting the metal complex include silver, copper, gold, aluminum, magnesium, tungsten, molybdenum, zinc, nickel, palladium, iron, platinum, tin, copper, and lead. Among these, from the viewpoint of electrical conductivity, the metal constituting the metal complex preferably contains at least one selected from the group consisting of silver, gold, platinum, nickel, palladium, and copper, more preferably contains at least one of silver and copper, and even more preferably contains silver.

[0055] The metal complex can be obtained, for example, by reacting a metal salt with a complexing agent. Examples of methods for producing a metal complex include adding a metal salt and a complexing agent to an organic solvent and stirring for a predetermined period of time. The stirring method is not particularly limited and can be appropriately selected from known methods such as stirring using a stirrer, stirring blades, or mixer, and using ultrasonic waves.

[0056] Examples of metal salts include metal oxides, thiocyanates, sulfides, chlorides, cyanides, cyanates, carbonates, acetates, nitrates, nitrites, sulfates, phosphates, perchlorates, tetrafluoroborates, acetylacetonate complex salts, and carboxylates.

[0057] Examples of the complexing agent include amines, ammonium carbamate compounds, ammonium carbonate compounds, ammonium bicarbonate compounds, and carboxylic acids. Among these, from the viewpoint of electrical conductivity and stability of the metal complex, it is preferable that the complexing agent contains 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.

[0058] The metal complex has a structure derived from a complexing agent, and is preferably a metal complex having a structure derived from at least one compound selected from the group consisting of ammonium carbamate compounds, ammonium carbonate compounds, amines, and carboxylic acids having 8 to 20 carbon atoms.

[0059] Examples of amine complexing agents include ammonia, primary amines, secondary amines, tertiary amines, and polyamines.

[0060] Specific examples of primary amines having a linear alkyl group include methylamine, ethylamine, 1-propylamine, n-butylamine, n-pentylamine, n-hexylamine, heptylamine, octylamine, nonylamine, n-decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, and octadecylamine.

[0061] Specific examples of primary amines having a branched alkyl group include isopropylamine, sec-butylamine, tert-butylamine, isopentylamine, 2-ethylhexylamine, and tert-octylamine.

[0062] Specific examples of primary amines having an alicyclic structure include cyclohexylamine and dicyclohexylamine.

[0063] Specific examples of primary amines having a hydroxyalkyl group include ethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, propanolamine, isopropanolamine, dipropanolamine, diisopropanolamine, tripropanolamine, and triisopropanolamine.

[0064] Specific examples of primary amines having an aromatic ring include benzylamine, N,N-dimethylbenzylamine, phenylamine, diphenylamine, triphenylamine, aniline, N,N-dimethylaniline, N,N-dimethyl-p-toluidine, 4-aminopyridine, and 4-dimethylaminopyridine.

[0065] Specific examples of secondary amines include dimethylamine, diethylamine, dipropylamine, dibutylamine, diphenylamine, dicyclopentylamine, and methylbutylamine.

[0066] Specific examples of tertiary amines include trimethylamine, triethylamine, tripropylamine, and triphenylamine.

[0067] Specific examples of polyamines include ethylenediamine, 1,3-diaminopropane, diethylenetriamine, triethylenetetramine, tetramethylenepentamine, hexamethylenediamine, tetraethylenepentamine, and combinations thereof.

[0068] The amine is preferably an alkylamine, more preferably an alkylamine having 3 to 10 carbon atoms, and even more preferably a primary alkylamine having 4 to 10 carbon atoms.

[0069] When reacting a metal salt with an amine, the ratio of the amount of amine to the amount of metal salt is preferably 1 to 15, more preferably 1.5 to 6. When the ratio is within the above range, the complex formation reaction is completed and a transparent solution is obtained.

[0070] Specific examples of the ammonium carbamate-based compound that is a complexing agent include ammonium carbamate, methylammonium methylcarbamate, ethylammonium ethylcarbamate, 1-propylammonium 1-propylcarbamate, isopropylammonium isopropylcarbamate, butylammonium butylcarbamate, isobutylammonium isobutylcarbamate, amylammonium amylcarbamate, hexylammonium hexylcarbamate, heptylammonium heptylcarbamate, octylammonium octylcarbamate, 2-ethylhexylammonium 2-ethylhexylcarbamate, nonylammonium nonylcarbamate, and decylammonium decylcarbamate.

[0071] Specific examples of the ammonium carbonate-based compound that is a complexing agent include ammonium carbonate, methylammonium carbonate, ethylammonium carbonate, 1-propylammonium carbonate, isopropylammonium carbonate, butylammonium carbonate, isobutylammonium carbonate, amylammonium carbonate, hexylammonium carbonate, heptylammonium carbonate, octylammonium carbonate, 2-ethylhexylammonium carbonate, nonylammonium carbonate, and decylammonium carbonate.

[0072] Specific examples of the ammonium bicarbonate compound that is a complexing agent include ammonium bicarbonate, methylammonium bicarbonate, ethylammonium bicarbonate, 1-propylammonium bicarbonate, isopropylammonium bicarbonate, butylammonium bicarbonate, isobutylammonium bicarbonate, amylammonium bicarbonate, hexylammonium bicarbonate, heptylammonium bicarbonate, octylammonium bicarbonate, 2-ethylhexylammonium bicarbonate, nonylammonium bicarbonate, and decylammonium bicarbonate.

[0073] When reacting a metal salt with an ammonium carbamate compound, an ammonium carbonate compound, or an ammonium bicarbonate compound, the ratio of the substance amount of the ammonium carbamate compound, the ammonium carbonate compound, or the ammonium bicarbonate compound to the substance amount of the metal salt is preferably 0.01 to 1 time, and more preferably 0.05 to 0.6 time.

[0074] Specific examples of the carboxylic acid as a complexing agent include caproic acid, caprylic acid, pelargonic acid, 2-ethylhexanoic acid, capric acid, neodecanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, palmitoleic acid, oleic acid, linoleic acid, and linolenic acid. Of these, the carboxylic acid is preferably a carboxylic acid having 8 to 20 carbon atoms, and more preferably a carboxylic acid having 10 to 16 carbon atoms.

[0075] The content of the metal in the metal complex ink is preferably 1 to 40 mass %, more preferably 5 to 30 mass %, and even more preferably 7 to 20 mass %, calculated as metal atoms, relative to the total mass of the metal complex ink.

[0076] The content of the metal complex in the metal complex ink is preferably 10 to 90% by mass, and more preferably 10 to 40% by mass, based on the total mass of the metal complex ink. When the content of the metal complex is 10% by mass or more, the surface resistivity is further reduced. When the content of the metal complex is 90% by mass or less, the ejection stability of the metal complex ink is further improved.

[0077] -Silane Coupling Agent- The metal complex ink preferably contains a silane coupling agent in view of excellent adhesion after immersion in a plating solution. The silane coupling agent is, for example, a compound having a hydrolyzable group directly bonded to a silicon atom. Examples of the hydrolyzable group include an alkoxy group (preferably having 1 to 10 carbon atoms) and a halogen atom such as a chlorine atom, with an alkoxy group being preferred in view of stability. The number of hydrolyzable groups directly bonded to a silicon atom in the silane coupling agent is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more. There is no upper limit to the number, and it may be, for example, 10,000 or less.

[0078] It is also preferable that the silane coupling agent has a reactive group. Specific examples of the reactive group include an epoxy group, an oxetanyl group, a vinyl group, a (meth)acrylic group, a styryl group, an amino group, an isocyanate group, a mercapto group, and an acid anhydride group. The number of reactive groups contained in the silane coupling agent is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more. There is no upper limit to the number, and it is, for example, 10,000 or less. The boiling point (standard boiling point) of the silane coupling agent is preferably 100°C or more, more preferably 180°C or more.

[0079] Examples of silane coupling agents include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and N-2-(aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, hexamethyldisilazane, 3-(2-aminoethylaminopropyl)dimethoxymethylsilane, 3-(2-aminoethylaminopropyl)trimethoxysilane, 2-(2-aminoethylthioethyl)diethoxymethylsilane, 2-(2-aminoethylthioethyl)triethoxysilane, 3-[2-(2-aminoethylaminoethylamino)propyl]trimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, imidazolylalkyl-trialkoxysilane, diphenyldimethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane, trifluoropropyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyltriethoxysilane, phenyltriethoxysilane, tris[3-(trimethoxysilyl)propyl] isocyanurate, and 3-trimethoxysilylpropylsuccinic anhydride. ,

[0080] The content of the silane coupling agent in the metal complex ink is preferably 0.1 to 5.0 mass %, more preferably 0.2 to 4.0 mass %, relative to the total mass of the metal complex ink, and even more preferably 0.5 to 3.0 mass %, from the viewpoint of achieving better conductivity and suppression of migration.

[0081] -Solvent- The metal complex ink preferably contains a solvent. The solvent is not particularly limited as long as it can dissolve the components contained in the metal complex ink, such as the metal complex. From the viewpoint of ease of production, the boiling point of the solvent is preferably 30 to 300°C, more preferably 50 to 200°C, and even more preferably 80 to 180°C.

[0082] The solvent is preferably contained in the metal complex ink so that the concentration of metal ions relative to the metal complex (the amount of metal present as free ions per gram of metal complex) is 0.01 to 3.6 mmol / g, and more preferably 0.05 to 2 mmol / g. When the metal ion concentration is within the above range, the metal complex ink exhibits excellent fluidity and excellent conductivity.

[0083] Examples of solvents include water, hydrocarbons, cyclic hydrocarbons, aromatic hydrocarbons, terpenes, carbamates, alkenes, amides, ethers, esters, alcohols, thiols, thioethers, phosphines, and water.

[0084] The hydrocarbon is preferably a linear or branched hydrocarbon having a carbon number of 6 to 20. Specific examples of the hydrocarbon include pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, octadecane, nonadecane, and icosane.

[0085] The cyclic hydrocarbon is preferably a cyclic hydrocarbon having a carbon number of 6 to 20. Specific examples of the cyclic hydrocarbon include cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, and decalin.

[0086] Specific examples of aromatic hydrocarbons include benzene, toluene, xylene, trimethylbenzene, and tetralin.

[0087] Specific examples of terpenes include α-bisabolol, borneol, camphene, camphor, δ-3-carene, β-caryophyllene, caryophyllene oxide, α-cedrene, β-eudesmol, fenchol, geraniol, guaiol, α-humulene, isoborneol, limonene, linalool, menthol, myrcene, nerol, cis-ocimene, trans-ocimene, α-phellandrene, α-pinene, β-pinene, sabinene, α-terpinene, α-terpineol, terpinolene, α-guaiene, elemene, farnesene, germacrene B, guaia-1(10),11-diene, trans-2-pinanol, serina-3,7(11)-diene, and eudesmu-7(11)-en-4-ol.

[0088] The ether may be a linear ether, a branched ether, or a cyclic ether. Specific examples of the ether include diethyl ether, dipropyl ether, dibutyl ether, methyl t-butyl ether, tetrahydrofuran, tetrahydropyran, dihydropyran, and 1,4-dioxane.

[0089] The alcohol may be any of a primary alcohol, a secondary alcohol, and a tertiary alcohol. Specific examples of the alcohol 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, isodecyl alcohol, lauryl alcohol, isolauryl alcohol, myristyl alcohol, isomyristyl alcohol, cetyl alcohol (cetanol), isocetyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, isooleyl alcohol, linolyl alcohol, isolinolyl alcohol, palmityl alcohol, isopalmityl alcohol, eicosyl alcohol, and isoeicosyl alcohol.

[0090] Specific examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0091] Specific 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.

[0092] - Reducing Agent - The metal complex ink may contain a reducing agent, which promotes the reduction of the metal complex to metal.

[0093] Specific examples of reducing agents include metal borohydrides, aluminum hydrides, amines, alcohols, organic acids, reducing sugars, sugar alcohols, sodium sulfite, hydrazine compounds, dextrin, hydroquinone, hydroxylamine, ethylene glycol, glutathione, and oxime compounds.

[0094] The reducing agent may be an oxime compound described in JP-A No. 2014-516463. Specific examples of the oxime compound 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-adamantanone oxime, 2-methylbenzamide oxime, 3-methylbenzamide oxime, 4-methylbenzamide oxime, 3-aminobenzamide oxime, 4-aminobenzamide oxime, acetophenone oxime, benzamide oxime, and pinacolone oxime.

[0095] The content of the reducing agent in the metal complex ink is preferably 0.1 to 20% by mass, more preferably 0.3 to 10% by mass, and even more preferably 1 to 5% by mass, based on the total mass of the metal complex ink.

[0096] Resin The metal complex ink may contain a resin, which improves the adhesion of the metal complex ink to the substrate.

[0097] Examples of resins include polyester, polyethylene, polypropylene, polyacetal, polyolefin, polycarbonate, polyamide, fluororesin, silicone resin, ethyl cellulose, hydroxyethyl cellulose, rosin, acrylic resin, polyvinyl chloride, polysulfone, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl resin, polyacrylonitrile, polysulfide, polyamideimide, polyether, polyarylate, polyether ether ketone, polyurethane, epoxy resin, vinyl ester resin, phenolic resin, melamine resin, and urea resin.

[0098] -Additives- The metal complex ink may contain additives such as inorganic salts, organic salts, inorganic oxides such as silica, surface conditioners, wetting agents, crosslinking agents, antioxidants, rust inhibitors, heat stabilizers, surfactants, plasticizers, curing agents, and thickeners. The content of the additives in the metal complex ink is preferably 20% by mass or less relative to the total mass of the metal complex ink. The lower limit may be 0% by mass or more.

[0099] -Physical Properties- The viscosity of the metal complex ink is preferably 1 to 100 mPa·s, more preferably 2 to 50 mPa·s, and even more preferably 3 to 30 mPa·s. The viscosity of the metal complex ink is a value measured at 25°C using a viscometer. The viscosity is measured, for example, using a VISCOMETER TV-22 viscometer (manufactured by Toki Sangyo Co., Ltd.).

[0100] The surface tension of the metal complex ink is not particularly limited, but is preferably 20 to 45 mN / m, and more preferably 25 to 35 mN / m. The surface tension is a value measured at 25°C using a surface tensiometer. The surface tension is measured, for example, using a DY-700 (manufactured by Kyowa Interface Science Co., Ltd.).

[0101] (Metal Salt Ink) Metal salt ink is, for example, a conductive ink in which a metal salt is dissolved in a solvent.

[0102] -Metal Salt- The metal constituting the metal salt is the same as the metal constituting the metal complex described above, and the preferred embodiments are also the same.

[0103] Examples of metal salts include metal benzoates, halides, carbonates, citrates, iodates, nitrites, nitrates, acetates, phosphates, sulfates, sulfides, trifluoroacetates, and carboxylates. Two or more types of salts may be used in combination.

[0104] The metal salt is preferably a metal carboxylate in terms of conductivity and storage stability. The carboxylic acid forming the metal 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 may be linear or branched, and may have a substituent.

[0105] Specific examples of straight-chain fatty acids include acetic acid, propionic acid, butyric acid, valeric acid, pentanoic acid, hexanoic acid, heptanoic acid, behenic acid, oleic acid, octanoic acid, nonanoic acid, decanoic acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, and undecanoic acid.

[0106] Specific examples of branched fatty acids include isobutyric acid, isovaleric acid, ethylhexanoic acid, neodecanoic acid, pivalic acid, 2-methylpentanoic acid, 3-methylpentanoic acid, 4-methylpentanoic acid, 2,2-dimethylbutanoic acid, 2,3-dimethylbutanoic acid, 3,3-dimethylbutanoic acid, and 2-ethylbutanoic acid.

[0107] Specific examples of substituted carboxylic acids include hexafluoroacetylacetonate, hydroangelic acid, 3-hydroxybutyric acid, 2-methyl-3-hydroxybutyric acid, 3-methoxybutyric acid, acetonedicarboxylic acid, 3-hydroxyglutaric acid, 2-methyl-3-hydroxyglutaric acid, and 2,2,4,4-hydroxyglutaric acid.

[0108] The metal salt may be a commercially available product or may be produced by a known method. The silver salt is produced, for example, by the following method.

[0109] First, a silver compound (e.g., silver acetate) that serves as a silver source and an equal amount of formic acid or a fatty acid having 1 to 30 carbon atoms to the molar equivalent of the silver compound are added to an organic solvent such as ethanol. The mixture is stirred for a predetermined time using an ultrasonic agitator, and the resulting precipitate is washed with ethanol and decanted. All of these steps can be carried out at room temperature (25°C). The mixing ratio of the silver compound to the formic acid or the fatty acid having 1 to 30 carbon atoms is preferably 1:2 to 2:1, and more preferably 1:1, in molar ratio.

[0110] The content of the metal in the metal salt ink is preferably 1 to 40 mass %, more preferably 5 to 30 mass %, and even more preferably 7 to 20 mass %, calculated as the metal element, relative to the total mass of the metal salt ink.

[0111] The content of the metal salt in the metal salt ink is preferably 10 to 90% by mass, and more preferably 10 to 60% by mass, based on the total mass of the metal salt ink. When the content of the metal salt is 10% by mass or more, the surface resistivity is further reduced. When the content of the metal salt is 90% by mass or less, the ejection stability is further improved when the metal salt ink is ejected from a nozzle.

[0112] Solvent The metal salt ink may contain a solvent, such as hydrocarbons, cyclic hydrocarbons, aromatic hydrocarbons, terpenes, carbamates, alkenes, amides, ethers, esters, alcohols, thiols, thioethers, phosphines, and water.

[0113] The hydrocarbon is preferably a linear or branched hydrocarbon having a carbon number of 6 to 20. Specific examples of the hydrocarbon include pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, octadecane, nonadecane, and icosane.

[0114] The cyclic hydrocarbon is preferably a cyclic hydrocarbon having a carbon number of 6 to 20. Specific examples of the cyclic hydrocarbon include cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, and decalin.

[0115] Specific examples of aromatic hydrocarbons include benzene, toluene, xylene, trimethylbenzene, and tetralin.

[0116] Specific examples of terpenes include α-bisabolol, borneol, camphene, camphor, δ-3-carene, β-caryophyllene, caryophyllene oxide, α-cedrene, β-eudesmol, fenchol, geraniol, guaiol, α-humulene, isoborneol, limonene, linalool, menthol, myrcene, nerol, cis-ocimene, trans-ocimene, α-phellandrene, α-pinene, β-pinene, sabinene, α-terpinene, α-terpineol, terpinolene, α-guaiene, elemene, farnesene, germacrene B, guaia-1(10),11-diene, trans-2-pinanol, serina-3,7(11)-diene, and eudesmu-7(11)-en-4-ol.

[0117] The ether may be a linear ether, a branched ether, or a cyclic ether. Specific examples of the ether include diethyl ether, dipropyl ether, dibutyl ether, methyl t-butyl ether, tetrahydrofuran, tetrahydropyran, dihydropyran, and 1,4-dioxane.

[0118] The alcohol may be any of a primary alcohol, a secondary alcohol, and a tertiary alcohol. Specific examples of the alcohol 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, isodecyl alcohol, lauryl alcohol, isolauryl alcohol, myristyl alcohol, isomyristyl alcohol, cetyl alcohol (cetanol), isocetyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, isooleyl alcohol, linolyl alcohol, isolinolyl alcohol, palmityl alcohol, isopalmityl alcohol, eicosyl alcohol, and isoeicosyl alcohol.

[0119] Specific examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0120] Specific 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.

[0121] Silane Coupling Agent The metal salt ink preferably contains a silane coupling agent. The silane coupling agent is the same as the silane coupling agent in the metal complex ink described above, and preferred embodiments are also the same.

[0122] Other Components The metal salt ink may contain a reducing agent, a resin, and an additive. The reducing agent, the resin, and the additive are the same as the various components in the metal complex ink described above, and preferred embodiments are also the same.

[0123] Physical Properties The viscosity and surface tension of the metal salt ink are the same as those of the metal complex ink described above, and the preferred embodiments are also the same.

[0124] Examples of the method for applying the ink include the method for applying the composition described above. The coating film formed by applying the ink may be dried as needed. Examples of the drying method include natural drying and heat drying. Drying may also be performed under normal pressure or reduced pressure.

[0125] The ink may be applied by an inkjet recording method, which may be any of a charge control method that uses electrostatic attraction to eject ink, a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezoelectric element, an acoustic inkjet method that converts an electric signal into an acoustic beam and irradiates the ink with the acoustic beam to eject the ink by using radiation pressure, and a thermal inkjet (Bubble Jet (registered trademark)) method that heats the ink to form bubbles and uses the resulting pressure.

[0126] The inkjet recording method is preferably the method described in JP-A-54-059936, and more preferably an inkjet recording method in which ink subjected to the action of thermal energy undergoes a sudden volume change, and the ink is ejected from a nozzle by the force caused by this state change. Further, as an inkjet recording method, for example, the method described in paragraphs 0093 to 0105 of JP-A-2003-306623 can also be mentioned.

[0127] Examples of inkjet heads used in inkjet recording methods include a shuttle method in which a short serial head is used to perform recording while scanning the head in the width direction of the substrate, and a line method in which a line head is used in which recording elements are arranged corresponding to the entire area of ​​at least one side of the substrate.

[0128] The line method can form a pattern over the entire surface of a substrate by scanning the substrate in a direction intersecting the array direction of the recording elements, eliminating the need for a transport system such as a carriage for scanning a short head. Furthermore, since complex scanning control of the carriage movement and the substrate is unnecessary and only the substrate moves, the formation speed can be increased compared to the shuttle method.

[0129] An example of an inkjet recording apparatus that applies insulating ink using an inkjet recording method is DMP-2850 (manufactured by FUJIFILM DIMATIX).

[0130] The amount of ink droplets ejected from the nozzles of the inkjet head is preferably 1 to 100 pL (picoliters) per dot, more preferably 2 to 80 pL, and even more preferably 2 to 20 pL.

[0131] The temperature of the substrate when the ink is applied is preferably 20 to 120° C., more preferably 40 to 100° C. When the temperature of the substrate is 20 to 100° C., drying of the ink can be promoted while deformation of the substrate due to heat, etc., can be suppressed.

[0132] (Curing Treatment) The method for producing a laminate may further include a curing treatment in which the ink (coating film) applied on the metal oxide layer is cured by at least one of heating and light irradiation. This cures the ink, forming a metal layer X on the metal oxide layer. Only one of heating and light irradiation may be performed, or both may be performed.

[0133] The temperature when heating (baking temperature) is preferably 80°C or higher, more preferably 100°C or higher. The baking temperature is preferably 250°C or lower, more preferably 200°C or lower, in order to reduce damage to the substrate, etc. The time when heating (baking time) is preferably 1 minute or longer. The baking temperature is preferably 120 minutes or lower, more preferably 60 minutes or lower, in order to reduce damage to the substrate, etc.

[0134] The substrate may be preheated before the ink is applied to the substrate. In the present invention, such heating is also considered to be one form of heating. The temperature of the substrate when the ink is applied is preferably 20 to 180°C, more preferably 40 to 150°C.

[0135] Specific examples of light for light irradiation include ultraviolet light and infrared light. The peak wavelength of ultraviolet light is preferably 200 to 405 nm, more preferably 250 to 400 nm, and even more preferably 260 to 400 nm. The exposure dose for light irradiation is 0.1 to 10,000 J / cm. ２ is preferred, and 1 to 500 J / cm ２ is more preferred.

[0136] In the present invention, the time from the time the ink lands on the substrate to the start of heating or light irradiation is preferably 1 second or less, more preferably 0.8 seconds or less, and even more preferably 0.6 seconds or less, which promotes the reduction of the metal complex and metal salt contained in the ink that has landed on the substrate to metal (i.e., prevents the reduction from being inhibited by oxygen in the air), allowing the formation of a metal layer X with improved conductivity.

[0137] Step 2 may be repeated. This allows the thickness of the metal layer X to be adjusted. The thickness of the metal layer X is preferably 0.1 to 5.0 μm, more preferably 0.1 to 3.0 μm. The thickness of the metal layer X can be measured by obtaining a cross-sectional image of the metal layer X using a scanning electron microscope, measuring the length of 10 different positions corresponding to the thickness of the metal layer X, and calculating the arithmetic mean value of the lengths at those 10 points. The volume resistivity of the metal layer X is preferably 6 μΩ·cm or less, more preferably 5 μΩ·cm or less, and even more preferably 4 μΩ·cm or less, in order to provide superior conductivity of the metal layer X. The lower limit is preferably 2 μΩ·cm or more. The porosity of the metal layer X is preferably 24% or less, more preferably 23% or less, and even more preferably 22% or less, in order to provide superior conductivity of the metal layer X. The lower limit of the porosity is not particularly limited, and is, for example, 0%.

[0138] <Step 3> Step 3 is a step of plating the metal layer X after step 2 to form a metal layer Y containing a third metal atom of a type different from both the first metal atom and the second metal atom on the metal layer X. The metal layer Y is the same as the metal layer Y that may be contained in the above-mentioned laminate, and the preferred embodiments are also the same. Examples of the plating method include an electroless plating method and an electrolytic plating method, and may be a known plating method.

[0139] In the electroless plating method, for example, an electroless plating solution is brought into contact with at least a portion or all of the surfaces of the substrate, the metal oxide layer, and the metal layer X, thereby depositing a metal such as copper contained in the electroless plating solution to form an electroless plated layer (film) consisting of a metal film. The electroless plating solution is preferably a solution containing the third metal atom contained in the metal layer Y, a reducing agent, and a solvent. Examples of reducing agents include dimethylaminoborane, hypophosphorous acid, sodium hypophosphite, dimethylamineborane, hydrazine, formaldehyde, sodium borohydride, and phenol. Examples of solvents include those that may be contained in the above-mentioned composition.

[0140] The electroless plating solution may contain a complexing agent. Examples of the complexing agent include organic acids and their salts (e.g., sodium salts, potassium salts, and ammonium salts), and amine compounds such as ethylenediamine, diethylenetriamine, and triethylenetetramine. Examples of the organic acids and their salts include monocarboxylic acids such as acetic acid and formic acid; dicarboxylic acids such as malonic acid, succinic acid, adipic acid, maleic acid, and fumaric acid; hydroxycarboxylic acids such as malic acid, lactic acid, glycolic acid, gluconic acid, and citric acid; amino acids such as glycine, alanine, iminodiacetic acid, arginine, aspartic acid, and glutamic acid; and aminopolycarboxylic acids such as iminodiacetic acid, nitrilotriacetic acid, ethylenediaminediacetic acid, ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic acid.

[0141] Electrolytic plating is a method in which, for example, an electroless plating layer (film) formed by electroless plating treatment is subjected to current application while the electrolytic plating solution is in contact with the surface of the electroless plating layer (film), thereby depositing metals such as copper contained in the electrolytic plating solution on the surface of the electroless plating layer (film) formed by electroless treatment, which is placed at a cathode, to form an electrolytic plating layer (film).

[0142] The electrolytic plating solution preferably contains the third metal atom contained in the metal layer Y, an acid such as sulfuric acid or a carboxylic acid, and a solvent. Examples of the solvent include the solvents that can be contained in the composition.

[0143] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment details, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0144] [Ink Preparation] <Ink 1> Silver neodecanoate was placed in a 2000 mL three-neck flask. Next, a limonene solution containing 3% by mass of 2,2,6,6-tetramethyl-3,5-heptanedione and 1.5% by mass of 3-glycidoxypropyltrimethoxysilane was added and stirred to obtain a solution containing a silver salt. This solution was filtered using a PTFE (polytetrafluoroethylene) membrane filter with a pore size of 0.45 μm to obtain Ink 1. The content of silver neodecanoate was 45% by mass relative to the total mass of the solution containing the silver salt, and the content of the limonene solution was 55% by mass relative to the total mass of the solution containing the silver salt.

[0145] <Inks 2 to 5> Inks 2 to 5 were prepared in the same manner as Ink 1, except that the content of 3-glycidoxypropyltrimethoxysilane in each ink was changed to the value in the table below.

[0146] [Example 1] <Step 1> A titanium coupling agent (PC200, manufactured by Matsumoto Fine Chemical Co., Ltd.) was diluted to 16 mass% with a solution containing ethyl acetate / butanol at a volume ratio of 1:1 to obtain a diluted solution. The diluted solution was applied to a slide glass (S9111, manufactured by Matsunami Glass Co., Ltd.) using a #4 bar coater and then dried at 120°C for 30 seconds to form a metal oxide layer on the substrate, thereby obtaining a substrate with a metal oxide layer. The thickness of the metal oxide layer was 200 nm.

[0147] <Step 2> Ink 5 was filled into an inkjet recording device (product name "Samba G3L", manufactured by FUJIFILM DIMATIX Corporation). The image recording conditions were a resolution of 1200 dpi (dots per inch) and a droplet volume of 5 pL per dot. A 3 mm x 50 mm, 40 μm (wet) image was printed at 23°C on the substrate with the metal oxide layer prepared in step 1. Thereafter, the substrate was sintered at 180°C for 60 minutes using a hot plate to form a metal layer X on the metal oxide layer, thereby obtaining the laminate of Example 1.

[0148] Examples 2 to 12 and Comparative Examples 1 to 3 Each laminate was obtained in the same manner as in Example 1, except that the conditions were changed as shown in the table below.

[0149] [Measurement of the number of atoms contained in the metal layer X] Each laminate was analyzed for Ag3d, C1s, O1s, Si2s, Ti2p, Zr3d, and Al2p in a 300 μm square area using an X-ray photoelectron spectrometer (XPS) (manufactured by UlvacPHI). Ar sputtering was used for depth direction analysis.

[0150] [Adhesion after immersion in plating solution] A 5 cm square solid image sample was prepared from each laminate. The obtained sample was immersed for 30 minutes in the following plating solution heated to 60°C. Thereafter, the sample was removed from the plating solution and dried at 60°C for 30 minutes.

[0151] -------------------------------------------------- Plating solution -------------------------------------------------- NiSO ４ ・6H ２ O 0.95mol / L ・NiCl ２ ・6H ２ O 0.17mol / L・H ３ BO ３ 0.49mol / L ・FeSO ４ ・7H ２ O 0.35mol / L・C ７ H ４ NNaO ３ S・2H ２ O 0.008 mol / L Malonic acid 0.1 mol / L -----------------------------------

[0152] The samples treated with the plating solution were subjected to a crosshatch test using the following method to evaluate the adhesion after immersion in the plating solution. Six notches were made in each of the directions perpendicular to each other on the surface of the metal layer X. A piece of cellophane tape (Cellotape (registered trademark) CT-18, manufactured by Nichiban Co., Ltd.) was attached to the metal layer X with the notches, and then the tape piece was peeled off from the metal layer X. The peeling of the metal layer X (exposure of the underlying layer) on the surface from which the tape piece had been peeled off and the amount of metal layer X adhering to the peeled tape piece were visually observed, and the adhesion after immersion in the plating solution was evaluated from the observation results based on the following evaluation criteria.

[0153] <Evaluation criteria for adhesion after immersion in plating solution> "5": No peeling is observed on the surface of the metal layer X, and no black or silver deposits are observed on the tape piece. "4": Slight peeling of the metal layer X is observed only at the intersections of the incisions on the surface of the metal layer X, and / or slight black or silver deposits are observed on the tape piece. "3": Slight peeling of the metal layer X is observed only at the intersections of the incisions on the surface of the metal layer X, and black or silver deposits are observed on the tape piece, covering an area less than 10% of the area of ​​the crosshatched incisions. "2": Peeling of the metal layer X is observed on the surface of the metal layer X, covering an area less than 10% of the area of ​​the crosshatched incisions, and / or black or silver deposits are observed on the tape piece, covering an area 10% to less than 50% of the area of ​​the crosshatched incisions. "1": Peeling of the metal layer X is observed on the surface of the metal layer X over an area of ​​10% or more of the area of ​​the crosshatched cuts, and / or black or silver deposits are observed on the tape piece over an area of ​​50% or more of the area of ​​the crosshatched cuts.

[0154] [Conductivity (Volume Resistivity)] The resistance of each prepared metal layer X was measured at room temperature (23°C) using a resistance meter (product name "DT4222", manufactured by Hioki E.E. Corporation). In addition, the cross-sectional area of ​​each laminate was measured at room temperature (23°C) using a scanning electron microscope (product name "S-4700", manufactured by Hitachi Corporation). The volume resistivity (μΩ cm) was calculated from the measured resistance value and cross-sectional area, and the obtained volume resistivity was evaluated based on the following evaluation criteria. The lower the volume resistivity, the better the conductivity of the laminate.

[0155] <Evaluation criteria for electrical conductivity> "5": Less than 10 μΩ·cm "4": 10 μΩ·cm or more and less than 15 μΩ·cm "3": 15 μΩ·cm or more and less than 17.5 μΩ·cm "2": 17.5 μΩ·cm or more and less than 20 μΩ·cm "1": 20 μΩ·cm or more

[0156] [Migration occurrence] The metal layer X of each laminate was etched into a comb-shaped pattern with a line and space (L / S) of 50 / 50 μm by photolithography to form a comb-shaped silver wiring. At this time, Photec H-7025 (trade name, manufactured by Hitachi Chemical Co., Ltd.) was used as the dry film resist, and Agripp 940 (trade name, manufactured by Meltex Corporation) was used as the silver etching solution. Furthermore, Cytop (registered trademark) CTL107MK (trade name, manufactured by AGC, amorphous fluororesin) was spin-coated onto the obtained silver wiring so that the film thickness after drying was 1 μm. After that, the substrate was dried in an oven at 140 ° C. for 20 minutes to form a sealing layer, and a wiring board for evaluation of migration occurrence was prepared. The obtained wiring board was subjected to a life test (apparatus used: EHS-221MD, manufactured by Espec Corporation) under conditions of relative humidity 85%, temperature 85 ° C., pressure 1.0 atm, and voltage 60 V. Specifically, under the above environment, the above voltage was continuously applied to the silver wirings between adjacent comb-shaped teeth (distance between silver wirings: 100 μm), and the time from the start of application of the voltage until a short circuit occurred between the silver wirings due to migration was measured.

[0157] <Evaluation criteria for migration occurrence> "3": Short circuit occurrence time is 400 minutes or more; "2": Short circuit occurrence time is 300 minutes or more but less than 400 minutes; "1": Short circuit occurrence time is less than 300 minutes

[0158] In the table, "SR" indicates E-green solder paste (SR) plate (FR-4, 1.6t) manufactured by Matsuwa Sangyo Co., Ltd. When the "First Metal Atom" column contains "Ti," the metal oxide layer was formed according to the procedure of Example 1 using a titanium coupling agent (PC200, manufactured by Matsumoto Fine Chemical Co., Ltd.); when the column contains "Zr," the metal oxide layer was formed according to the procedure of Example 1 using a zirconium coupling agent (Zr-540, manufactured by Matsumoto Fine Chemical Co., Ltd.) instead of the titanium coupling agent; when the column contains "Al," the metal oxide layer was formed according to the procedure of Example 1 using an aluminum coupling agent (ethyl acetoacetate aluminum diisopropylate, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) instead of the titanium coupling agent. "GSC Amount" indicates the content of 3-glycidoxypropyltrimethoxysilane (silane coupling agent) relative to the total mass of the ink. "Si / (O+C)" indicates the ratio of the number of silicon atoms to the total number of oxygen atoms and carbon atoms (number of silicon atoms / total number of oxygen atoms and carbon atoms). "Si content", "O content", and "C content" each indicate the content of each atom relative to the total number of atoms in the metal layer X.

[0159]

[0160] The evaluation results shown in the table confirm that the laminate of the present invention and the laminate produced by the laminate production method of the present invention exhibit excellent adhesion after immersion in a plating solution (Examples 1 to 12). It was confirmed that when the metal layer X contains silicon atoms, the adhesion after immersion in a plating solution is even better (e.g., comparison between Example 1 and Examples 2 to 12). It was confirmed that when the number of silicon atoms in the metal layer X is 0.1 to 10.0 atomic % relative to the total number of atoms in the metal layer X, the electrical conductivity is even better and migration can be suppressed even more effectively (Examples 1 to 9, 11 to 12). Furthermore, similar comparisons confirmed that when the metal layer X contains oxygen atoms and carbon atoms and the ratio of the number of silicon atoms to the total number of oxygen atoms and carbon atoms in the metal layer X is 0.25 or more, the electrical conductivity is even better and migration can be suppressed even more effectively. It was confirmed that when the first metal atoms include titanium atoms, the adhesion after immersion in a plating solution was superior (e.g., comparison between Examples 2 to 9 and Examples 11 and 12). It was confirmed that when the thickness of the metal layer X was 0.1 to 3.0 μm, the adhesion after immersion in a plating solution was superior (e.g., comparison between Examples 2 to 9).

Claims

1. A laminate comprising a substrate, a metal oxide layer containing a first metal atom selected from the group consisting of titanium atoms, zirconium atoms, and aluminum atoms, and a metal layer X disposed adjacent to the metal oxide layer and containing a second metal atom of a type different from the first metal atom, wherein the thickness of the metal oxide layer is 50 to 2000 nm.

2. The laminate according to claim 1, wherein the metal layer X contains a silicon atom.

3. The laminate according to claim 1 or 2, wherein the metal layer X contains a silicon atom, and the number of silicon atoms in the metal layer X is 0.1 to 10.0 atomic% with respect to the total number of atoms in the metal layer X.

4. The laminate according to claim 1 or 2, wherein the metal layer X contains a silicon atom, an oxygen atom, and a carbon atom, and the ratio of the number of silicon atoms to the total number of oxygen and carbon atoms in the metal layer X is 0.25 or more.

5. The laminate according to claim 1 or 2, wherein the thickness of the metal layer X is 0.1 to 3.0 μm.

6. The laminate according to claim 1 or 2, having a metal layer Y on the metal layer X and containing a third metal atom of a type different from both the first metal atom and the second metal atom.

7. A method for manufacturing a laminate, comprising: step 1 of applying a composition containing a coupling agent selected from the group consisting of a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent onto a substrate to form a metal oxide layer containing a first metal atom selected from the group consisting of titanium atoms, zirconium atoms, and aluminum atoms; and step 2 of applying an ink containing a metal compound selected from the group consisting of a metal salt and a metal complex onto the metal oxide layer to form a metal layer X containing a second metal atom of a type different from the first metal atom, wherein the thickness of the metal oxide layer is 50 to 2000 nm.

8. The method for manufacturing a laminate according to claim 7, wherein the ink contains a silane coupling agent.

9. The method for manufacturing a laminate according to claim 7 or 8, further comprising step 3 of performing a plating treatment on the metal layer X to form a metal layer Y on the metal layer X and containing a third metal atom of a type different from both the first metal atom and the second metal atom.

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