阅读说明：本技术 层叠体、使用其的印刷布线板、挠性印刷布线板及成形品 (Laminate, printed wiring board using same, flexible printed wiring board, and molded article ) 是由 富士川亘 平林宪一 深泽宪正 白发润 于 2018-07-03 设计创作，主要内容包括：本发明提供一种层叠体,其特征在于,该层叠体为在支承体(A)上依次层叠有底漆层(B)、金属纳米粒子层(C)及金属镀敷层(D)的层叠体,上述底漆层(B)具有环氧基与羟基的树脂(b1)与含有多元羧酸的交联剂(b2)的固化物,本发明还提供使用该层叠体的印刷布线板、挠性印刷布线板及成形品。该层叠体可在不将支承体表面粗化的情况下,以简便的方法制造,且支承体与金属层(金属镀敷层)之间的密合性优异。(The present invention provides a laminate comprising a base coat layer (B), a metal nanoparticle layer (C) and a metal plating layer (D) laminated in this order on a support (A), wherein the base coat layer (B) comprises a cured product of an epoxy-and-hydroxyl-containing resin (B1) and a polycarboxylic acid-containing crosslinking agent (B2), and also provides a printed wiring board, a flexible printed wiring board and a molded article using the laminate. The laminate can be produced by a simple method without roughening the surface of the support, and has excellent adhesion between the support and the metal layer (metal plating layer).)

1. A laminate comprising a support (A) and, laminated thereon in this order, a primer layer (B) which is a cured product of a resin B1 having an epoxy group and a hydroxyl group and a crosslinking agent B2 containing a polycarboxylic acid, a metal nanoparticle layer (C), and a metal plating layer (D).

2. The laminate according to claim 1, wherein the polycarboxylic acid is an aromatic compound.

3. The laminate of claim 1 or 2, wherein the polycarboxylic acid is an anhydride.

4. The laminate according to any one of claims 1 to 3, wherein the resin b1 is a resin having an aromatic ring.

5. The laminate according to any one of claims 1 to 4, wherein the resin b1 is an acrylic resin.

6. The laminate according to any one of claims 1 to 5, wherein the molar ratio of the number of moles of carboxyl groups in the crosslinking agent b2 to the number of moles of epoxy groups in the resin b1 is 0.3 or more and 3 or less in [ carboxyl groups/epoxy groups ].

7. A printed wiring board using the laminate according to any one of claims 1 to 6.

8. A flexible printed wiring board, characterized by using the laminate according to any one of claims 1 to 6, wherein the support (A) is a film.

9. A molded article comprising the laminate according to any one of claims 1 to 6.

Technical Field

The present invention relates to a laminate useful for a printed wiring board, a flexible printed wiring board, a molded article, and the like.

Background

With the miniaturization and high speed of electronic devices, printed wiring boards are required to have higher density and higher performance, and in order to meet these requirements, printed wiring boards having a smooth surface and a sufficiently thin conductive layer (metal layer) are required. As a material constituting this printed wiring board, a flexible copper clad laminate (hereinafter, abbreviated as "FCCL") is known. FCCL is mainly produced by a method of bonding a heat-resistant polymer film and a copper foil using an epoxy resin adhesive.

However, in the FCCL using the copper foil, since the copper foil wound in a roll shape is pulled out and bonded, the copper foil cannot be sufficiently thinned in operation. Further, in order to improve the adhesion to the polymer film, the surface of the copper foil must be roughened, and therefore, there is a problem that transmission loss occurs in a field of high frequency (GHz band) and high transmission speed (several tens of Gbps) required for high density and high performance of the printed wiring board.

Here, as a method for making the copper layer of FCCL thin, there has been proposed a method in which a metal thin film is formed on the surface of a polyimide film by a vapor deposition method or a sputtering method, and then copper is formed on the metal thin film by an electroplating method, an electroless plating method, or a method combining both (for example, see patent document 1). However, in this method, since a vapor deposition method or a sputtering method is used to form a metal thin film, a large-scale vacuum apparatus is required, and there is a problem that the size of the substrate is limited in the apparatus.

Therefore, there is a need for a laminate which has sufficient adhesion to a support such as a polymer film without roughening the surface of a metal layer such as a copper foil, and which can be produced by a simple method without requiring a large-scale vacuum equipment when the metal layer is made thin.

In addition, conventionally, the metal plating is used as a decorative plating on a plastic molded product, for example, in a mobile phone, a personal computer, a mirror, a container, various switches, and a shower head. The supports for these applications are limited to acrylonitrile-butadiene-styrene copolymers (hereinafter, abbreviated as "ABS") or polymer alloys of ABS and polycarbonate (hereinafter, abbreviated as "ABS-PC"). The reason for this is that the surface of the substrate must be roughened in order to ensure adhesion between the substrate and the plating film, and in the case of ABS, for example, the surface can be roughened by etching and removing the polybutadiene component with a strong oxidizing agent such as hexavalent chromic acid or permanganate. However, hexavalent chromic acid and the like are environmentally-friendly substances and are preferably not used, and alternative methods have been developed (for example, see patent document 2).

Therefore, in plating for the purpose of decoration or the like on plastic molded articles, a method is required in which a metal plating film having excellent adhesion is obtained even with other types of plastics without limiting the substrate to ABS or ABS-PC, and the amount of environmental load substances to be used is reduced.

Disclosure of Invention

Technical problem to be solved

The present invention addresses the problem of providing a laminate which can be produced by a simple method without roughening the surface of a support and has excellent adhesion between the support and a metal layer (metal plating layer), and a printed wiring board, a flexible printed wiring board, and a molded article using the laminate.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems, and as a result, have found that the above problems can be solved by providing a layer containing a cured product of a resin having an epoxy group and a hydroxyl group and a crosslinking agent containing a carboxylic acid as a primer layer on a support, and sequentially laminating a metal layer comprising metal nanoparticles and a metal plating layer thereon, thereby completing the present invention.

That is, the present invention provides a laminate in which a primer layer (B), a metal nanoparticle layer (C), and a metal plating layer (D) are sequentially laminated on a support (a), wherein the primer layer (B) is a layer of a cured product of a resin (B1) having an epoxy group and a hydroxyl group and a crosslinking agent (B2) containing a polycarboxylic acid, and also provides a printed wiring board, a flexible printed wiring board, and a laminate using the laminate.

Effects of the invention

The laminate of the present invention has excellent adhesion between the support and the metal layer (metal plating layer) without roughening the surface of the support. In addition, when the metal layer is made thin, a laminate having a smooth surface and a sufficiently thin metal layer is obtained without using a large-scale vacuum apparatus.

The laminate of the present invention can be suitably used as electronic components such as printed wiring boards, flexible printed wiring boards, conductive films for touch panels, metal meshes for touch panels, organic solar cells, organic EL elements, organic transistors, RFIDs such as non-contact IC cards, electromagnetic wave barriers, LED lighting substrates, and digital signage by patterning the metal layer. In particular, it is most suitable for flexible printed wiring board applications such as FCCL. Further, the use of the resin composition in molded articles can be suitably applied to electronic components such as connectors, electric components, electric motor peripheral components, and battery components for connecting wires for optical communication and the like; automotive trim parts, lamp reflectors, mobile phones, personal computers, mirrors, containers, home appliances, various switches, faucet parts, sprinklers, and the like.

Detailed Description

The laminate of the present invention is a laminate in which a primer layer (B), a metal nanoparticle layer (C), and a metal plating layer (D) are laminated in this order on a support (a), wherein the primer layer (B) is a layer of a cured product of a resin (B1) having an epoxy group and a hydroxyl group and a crosslinking agent (B2) containing a polycarboxylic acid.

The laminate of the present invention may be a laminate in which a primer layer (B) or the like is sequentially laminated on one surface of the support (a), or may be a laminate in which a primer layer (B) or the like is sequentially laminated on both surfaces of the support (a).

Examples of the support (a) include supports comprising polyimide, polyamideimide, polyamide, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, acrylonitrile-butadiene-styrene (hereinafter abbreviated as "ABS") resin, a polymer alloy of ABS and polycarbonate, an acrylic resin such as poly (methyl (meth) acrylate), polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polycarbonate, polyethylene, polypropylene, polyurethane, Liquid Crystal Polymer (LCP), polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), epoxy resin, cellulose nanofiber, silicon, ceramics, glass, and the like, porous supports comprising these materials, supports comprising metal such as steel plate and copper, supports having silicon carbide, silicon nitride, silicon, And a support made of diamond-like carbon, aluminum, copper, titanium, stainless steel, or the like.

When the laminate of the present invention is used for a printed wiring board or the like, a support containing polyimide, polyethylene terephthalate, polyethylene naphthalate, Liquid Crystal Polymer (LCP), polyether ether ketone (PEEK), epoxy resin, glass, cellulose nanofibers, or the like is preferably used as the support (a).

When the laminate of the present invention is used for a flexible printed wiring board or the like, the support (a) is preferably a film-like or sheet-like support having flexibility capable of being bent.

When the support (A) is in the form of a film or a sheet, the thickness thereof is preferably 1 μm or more and 5000 μm or less, more preferably 1 μm or more and 300 μm or less, and particularly preferably 1 μm or more and 200 μm or less.

In addition, from the viewpoint of further improving the adhesion between the support (a) and the primer layer (B) described later, if necessary, fine irregularities may be formed on the surface of the support (a) to such an extent that smoothness is not lost, dirt may be washed off from the surface of the support (a), or a surface treatment may be performed for introducing a functional group such as a hydroxyl group, a carbonyl group, or a carboxyl group. Specifically, there may be mentioned a method of ion discharge treatment such as corona discharge treatment, dry treatment such as ultraviolet treatment, or wet treatment using an aqueous solution such as water or an acid-base or an organic solvent.

The primer layer (B) is a layer of a cured product of a resin (B1) having an epoxy group and a hydroxyl group and a crosslinking agent (B2) containing a polycarboxylic acid.

The resin (b1) has an epoxy group and a hydroxyl group in the molecule, and examples of the resin include epoxy resins and acrylic resins. The hydroxyl group of the resin (b1) may be an alcoholic hydroxyl group or a phenolic hydroxyl group. Further, 1 kind of the resin (b1) may be used, and 2 or more kinds of the plural resin types may be used in combination.

Examples of the epoxy resin used as the resin (b1) include a bisphenol a type epoxy resin, a bisphenol F type epoxy resin, a phenol novolac type epoxy resin, and the like. Bisphenol a epoxy resin and bisphenol F epoxy resin are obtained by reacting epichlorohydrin with bisphenol a or the like, and have an epoxy group and a hydroxyl group in the same molecule, and therefore, they can be preferably used as the resin (b1) as it is. In addition, since the phenol novolac epoxy resin reacts with epichlorohydrin to leave a phenolic hydroxyl group, it can be used as the resin (b 1). These epoxy resins may be used in 1 kind, or 2 or more kinds may be used in combination.

Examples of the acrylic resin used as the resin (b1) include resins obtained by copolymerizing, as essential raw materials, a (meth) acrylic monomer having an epoxy group and a (meth) acrylic monomer having a hydroxyl group. The term (meth) acrylic monomer means either or both of an acrylic monomer and a methacrylic monomer. The term (meth) acrylic acid means one or both of acrylic acid and methacrylic acid, and the term (meth) acrylate means one or both of acrylate and methacrylate.

Examples of the (meth) acrylic monomer having an epoxy group include glycidyl (meth) acrylate, 4-hydroxybutyl acrylate glycidyl ether, and allyl glycidyl ether. Among these (meth) acrylic monomers having an epoxy group, glycidyl methacrylate is preferable from the viewpoint of further improving the adhesion. Further, these epoxy group-containing (meth) acrylic monomers may be used in 1 kind, or 2 or more kinds may be used in combination.

In addition, examples of the (meth) acrylic monomer having a hydroxyl group include: 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) acrylate, glycerol (meth) acrylate, polyethylene glycol (meth) acrylate, N-hydroxyethyl (meth) acrylamide, N-hydroxypropyl (meth) acrylamide, N-hydroxybutyl acrylamide and the like. Among these hydroxyl group-containing (meth) acrylic monomers, 2-hydroxyethyl (meth) acrylate is preferable from the viewpoint of further improving the adhesion. Further, 1 kind of (meth) acrylic acid monomer having a hydroxyl group may be used, and 2 or more kinds may be used in combination.

As the other polymerizable monomers, there may be mentioned, for example, methyl (meth) acrylate, ethyl (meth) acrylate, N-propyl (meth) acrylate, isopropyl (meth) acrylate, N-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, N-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentanyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, 2,2, 2-trifluoroethyl (meth) acrylate, 2,2,3, 3-pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, 2, 2-ethylhexyl (meth) acrylate, bis (meth) ethylene glycol bis (meth) acrylate, bis (cyclohexyl) acrylate, bis (meth) acrylamide, bis (meth) acrylate, bis (ethylene glycol) acrylate, bis (ethylene glycol) acrylate, bis (.

The acrylic resin can be produced by polymerizing a mixture of the (meth) acrylic monomer and the like by a known method. Examples of the polymerization method include a solution polymerization method in which polymerization is carried out in an organic solvent, an emulsion polymerization method in which polymerization is carried out in an aqueous medium, a suspension polymerization method, a precipitation polymerization method, and a bulk polymerization method in which polymerization is carried out in the absence of a solvent.

Examples of the polymerization initiator used in the production of the acrylic resin include azo initiators such as azonitrile, azoester, azoamide, azoamidine, and azoimidazoline; organic peroxides such as peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, and peroxyesters; and inorganic peroxides such as ammonium persulfate, potassium persulfate, and hydrogen peroxide.

The radical polymerization may be carried out by using only the above peroxide, or by using a redox polymerization initiator system in which the above peroxide is used in combination with a reducing agent such as ascorbic acid, erythorbic acid, sodium erythorbate, a metal salt of formaldehyde sulfoxylate, sodium thiosulfate, sodium bisulfite, or ferric chloride.

The epoxy group concentration in the resin (b1) is preferably 0.05mmol/g or more and 8mmol/g or less, more preferably 0.5mmol/g or more and 3mmol/g or less, and particularly preferably 1mmol/g or more and 2mmol/g or less, from the viewpoint of further improving the adhesion.

The hydroxyl group concentration in the resin (b1) is preferably 0.05mmol/g or more and 3mmol/g or less, more preferably 0.1mmol/g or more and 2mmol/g or less, and particularly preferably 0.5mmol/g or more and 1.5mmol/g or less, from the viewpoint of further improving the adhesion.

Among the resins that can be used as the resin (b1), acrylic resins are preferred from the viewpoint of further improving adhesion.

The crosslinking agent (b2) contains a polycarboxylic acid. Anhydrides of the above polycarboxylic acids may also be used. Specific examples of the polycarboxylic acid include: aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, mellitic acid, biphenyldicarboxylic acid, biphenyltetracarboxylic acid, and naphthalenedicarboxylic acid, and anhydrides thereof; aliphatic polycarboxylic acids such as oxalic acid, malonic acid, succinic acid, methylsuccinic anhydride, ethylsuccinic anhydride, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, maleic acid, fumaric acid, 2, 3-butanedicarboxylic acid, 2, 4-pentanedicarboxylic acid, 3, 5-heptanedicarboxylic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, tetrahydrophthalic acid, norbornane-2, 3-dicarboxylic acid, methylnorbornane-2, 3-dicarboxylic acid, 1,2, 4-cyclohexanetricarboxylic acid, dodecylsuccinic acid, nadic acid, methylnadic acid, bicyclo [2.2.2] octane-2, 3-dicarboxylic acid and anhydrides thereof. Among these polycarboxylic acids, trimellitic anhydride is preferable from the viewpoint of further improving the adhesion. These polycarboxylic acids may be used in 1 kind, or 2 or more kinds may be used in combination.

The molar ratio [ carboxyl group/epoxy group ] of the number of moles of carboxyl groups in the crosslinking agent (b2) to the number of moles of epoxy groups in the resin (b1) is preferably 0.3 or more and 3 or less, more preferably 0.5 or more and 2.5 or less, from the viewpoint of further improving the adhesion.

In addition, a curing catalyst may be used to promote the reaction of the epoxy with the polycarboxylic acid. Examples of the curing catalyst include tertiary amines, imidazoles, organophosphines, and lewis acid catalysts.

Specific examples of the tertiary amine include: trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, trioctylamine, trilaurylamine, dimethylethylamine, dimethylpropylamine, dimethylbutylamine, dimethylpentylamine, dimethylhexylamine, dimethylcyclohexylamine, dimethyloctylamine, dimethyllaurylamine, triallylamine, tetramethylethylenediamine, triethylenediamine (triethylenetetramine: TETA), N-methylmorpholine, 4 '- (oxydi-2, 1-ethanediyl) bis-morpholine, N-dimethylbenzylamine, pyridine, picoline, dimethylaminomethylphenol, trisdimethylaminomethylphenol, triethanolamine, N' -dimethylpiperazine, tetramethylbutanediamine, bis (2, 2-morpholinoethyl) ether, bis (dimethylaminoethyl) ether, N, N ', N "-tris (dimethylaminopropyl) hexahydro-s-triazine, N ', N" -tris (dimethylaminoethyl) hexahydro-s-triazine, N ', N "-tris (2-hydroxyethyl) hexahydro-s-triazine, 2, 4-diamino-6- [2 ' -methylimidazolyl- (1 ') ] -ethyl-s-triazine, 1, 8-diazabicyclo [5.4.0] undec-1-ene, 1, 4-diazabicyclo [2.2.2] octane, 1, 8-diazabicyclo [5.4.0] undec-7-ene (DBU), and the like.

Specific examples of the imidazole compound include 1-benzyl-2-imidazole (1B2MZ), 2-ethyl-4-imidazole, 2-undecylimidazole, 1, 2-dimethylimidazole, 1-benzyl-2-phenylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (2P4 MHZ).

Specific examples of the organic phosphine include Triphenylphosphine (TPP), triphenylphosphine-triphenyl borate, tris (p-methoxyphenyl) phosphine, tetraphenylphosphonium-tetraphenyl borate, and the like.

Specific examples of the lewis acid catalyst include lewis acid catalysts such as boron trifluoride amine complex, boron trichloride amine complex, and boron trifluoride ethylamine complex.

Among these curing catalysts, tertiary amines and imidazole compounds are preferably used from the viewpoint of further improving the adhesion. Further, 1 kind of these curing catalysts may be used, or 2 or more kinds may be used in combination.

In order to form the primer layer (B) on the support (a), it is preferable to prepare a primer composition (B) containing the resin (B1) and the crosslinking agent (B2) and apply the primer composition (B) to the support (a). The primer composition (b) may contain, if necessary, other resins than the resin (b1) and the crosslinking agent (b 2). Examples of the other resin include urethane resin, acrylic resin, blocked isocyanate resin, melamine resin, and phenol resin. These other resins may be used in 1 kind, or 2 or more kinds may be used in combination.

In the primer composition (b), an organic solvent is preferably blended in order to obtain a viscosity that facilitates application when the primer composition is applied to the support (a). Examples of the organic solvent include toluene, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

The amount of the organic solvent used is preferably appropriately adjusted depending on the coating method used for coating the support (a) and the desired film thickness of the primer layer (B).

In addition, if necessary, known additives such as a film forming aid, a leveling agent, a thickener, a water repellent agent, an antifoaming agent, and an antioxidant may be added to the primer composition (b) and used as appropriate.

The primer layer (B) can be formed, for example, by applying the primer composition (B) to a part or the whole of the surface of the support (a) and removing the organic solvent contained in the primer composition (B).

Examples of the method for applying the primer composition (b) to the surface of the support (a) include gravure method, coating method, screen method, roll method, rotary method, spray method, capillary method, and the like.

After the primer composition (b) is applied to the surface of the support (a), the organic solvent contained in the coating layer is removed, for example, by drying with a dryer to evaporate the organic solvent. The drying temperature may be set within a range in which the organic solvent used is volatilized and the support (a) is not adversely affected by thermal deformation or the like.

The thickness of the primer layer (B) formed using the primer composition (B) varies depending on the application in which the laminate of the present invention is used, but is preferably within a range in which the adhesion between the support (a) and the metal nanoparticle layer (C) described later can be further improved, and the thickness of the primer layer is preferably 10nm or more and 30 μm or less, more preferably 10nm or more and 1 μm or less, and particularly preferably 10nm or more and 500nm or less.

From the viewpoint of further improving the adhesion to the metal nanoparticle layer (C), the surface of the primer layer (B) may be surface-treated by an ion discharge treatment method such as a corona discharge treatment method, a dry treatment method such as an ultraviolet treatment method, or a wet treatment method using water, an acidic or basic chemical solution, an organic solvent, or the like, as necessary.

The metal nanoparticle layer (C) is formed on the primer layer (B), and examples of the metal constituting the metal nanoparticle layer (C) include transition metals and compounds thereof, and among them, ionic transition metals are preferable. Examples of the ionic transition metal include copper, silver, gold, nickel, palladium, platinum, and cobalt. Among these, silver is preferable from the viewpoint of ease of formation of the metal plating layer (D).

Examples of the metal constituting the metal plating layer (D) include copper, nickel, chromium, cobalt, and tin. Among these, copper is preferable from the viewpoint of low electrical resistance and obtaining a laminate usable for a corrosion-resistant printed wiring board.

Examples of the method for producing the laminate of the present invention include: a method in which a primer layer (B) is formed on a support (a), a fluid containing nano-sized metal nanoparticles (C) is applied, an organic solvent or the like contained in the fluid is dried and removed to form a metal nanoparticle layer (C), and then the metal plating layer (D) is formed by electrolytic plating or electroless plating, or both.

The shape of the metal nanoparticles (C) for forming the metal nanoparticle layer (C) is preferably a particle shape or a fiber shape. The size of the metal nanoparticles (c) is a nanosize, and specifically, when the metal nanoparticles (c) are in a particle form, the average particle diameter is preferably 1nm or more and 100nm or less, more preferably 1nm or more and 50nm or less, from the viewpoint of forming a fine conductive pattern and further reducing the resistance value. The "average particle diameter" is a volume average value measured by a dynamic light scattering method using a well-dispersed solvent to dilute the conductive material. For this measurement, "NanotracUPA-150" manufactured by Microtrac corporation can be used.

On the other hand, when the metal nanoparticles (c) are in the form of fibers, the diameter of the fibers is also preferably in the range of 5nm to 100nm, more preferably in the range of 5nm to 50nm, from the viewpoint of forming a fine conductive pattern and further reducing the resistance value. The length of the fiber is preferably 0.1 to 100 μm, more preferably 0.1 to 30 μm.

The content of the metal nanoparticles (c) in the fluid is preferably 1 mass% or more and 90 mass% or less, more preferably 1 mass% or more and 60 mass% or less, and still more preferably 1 mass% or more and 10 mass% or less.

Examples of the component to be added to the fluid include a dispersant or a solvent for dispersing the metal nanoparticles (c) in a solvent, and if necessary, a surfactant, a leveling agent, a viscosity adjuster, a film-forming aid, an antifoaming agent, and an antiseptic agent, which will be described later.

In order to disperse the metal nanoparticles (c) in the solvent, it is preferable to use a low-molecular-weight or high-molecular-weight dispersant. Examples of the dispersant include dodecyl mercaptan, 1-octyl mercaptan, triphenylphosphine, dodecylamine, polyethylene glycol, polyvinylpyrrolidone, polyethyleneimine, and polyvinylpyrrolidone; fatty acids such as myristic acid, caprylic acid, and stearic acid; and polycyclic hydrocarbon compounds having a carboxyl group such as cholic acid, glycyrrhizic acid, and abietic acid. Among these, from the viewpoint of improving the adhesion between the metal nanoparticle layer (C) and the metal plating layer (D), a polymer dispersant is preferable, and examples of the polymer dispersant include polyethyleneimine such as polyethyleneimine or polypropyleneimine, a compound obtained by adding a polyoxyalkylene to the polyalkyleneimine, a urethane resin, an acrylic resin, and a compound containing a phosphoric group in the urethane resin or the acrylic resin.

The amount of the dispersant to be used for dispersing the metal nanoparticles (c) is preferably 0.01 to 50 parts by mass, more preferably 0.01 to 10 parts by mass, per 100 parts by mass of the metal nanoparticles (c).

As the solvent used in the fluid, an aqueous medium or an organic solvent can be used. Examples of the aqueous medium include distilled water, ion-exchanged water, pure water, and ultrapure water. Examples of the organic solvent include alcohol compounds, ether compounds, ester compounds, and ketone compounds.

Examples of the alcohol compound include: methanol, ethanol, n-propanol, isopropanol, n-butanol, i-butanol, sec-butanol, t-butanol, heptanol, hexanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, stearyl alcohol, allyl alcohol, cyclohexanol, terpineol, dihydroterpineol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, and the like.

In addition, in the fluid, ethylene glycol, diethylene glycol, 1, 3-butanediol, isoprene glycol, and the like may be used as necessary in addition to the metal nanoparticles (c) and the solvent.

As the surfactant, a common surfactant can be used, and examples thereof include di-2-ethylhexyl sulfosuccinate, dodecylbenzene sulfonate, alkyldiphenyl ether disulfonate, alkylnaphthalene sulfonate, hexametaphosphate, and the like.

As the leveling agent, a general leveling agent can be used, and examples thereof include silicone compounds, acetylene glycol compounds, fluorine compounds, and the like.

As the viscosity modifier, a general thickener can be used, and examples thereof include an acrylic polymer or a synthetic rubber latex which can be thickened by being adjusted to be alkaline, a urethane resin which can be thickened by molecular association, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol, hydrogenated castor oil, amide wax, oxidized polyethylene, a metal soap, dibenzylidene sorbitol, and the like.

As the above-mentioned film-forming assistant, a usual film-forming assistant can be used, and examples thereof include an anionic surfactant (e.g., dioctyl sodium sulfosuccinate), a hydrophobic nonionic surfactant (e.g., sorbitan monooleate), a polyether-modified silicone, and a silicone oil.

As the defoaming agent, a general defoaming agent can be used, and examples thereof include silicone defoaming agents, nonionic surfactants, polyethers, higher alcohols, and polymer surfactants.

As the preservative, a common preservative can be used, and examples thereof include an isothiazoline-based preservative, a triazine-based preservative, an imidazole-based preservative, a pyridine-based preservative, an azole-based preservative, an iodine-based preservative, and a pyrithione-based preservative.

The viscosity of the above-mentioned fluid (measured at 25 ℃ using a B-type viscometer) is preferably 0.1 to 500000 mPas, more preferably 0.2 to 10000 mPas. When the fluid is applied (printed) by an ink jet printing method, a relief reverse printing method, or the like, which will be described later, the viscosity is preferably 5mPa · s or more and 20mPa · s or less.

Examples of the method for applying or printing the fluid on the primer layer (B) include an inkjet printing method, a reverse printing method, a screen printing method, a lithographic printing method, a spin coating method, a spray coating method, a bar coating method, a die coating method, a slit coating method, a roll coating method, a dip coating method, a pad printing method, and a flexographic printing method.

Among these coating methods, for example, in forming the metal nanoparticle layer (C) patterned in a fine line shape of 0.01 μm or more and 100 μm or less, which is required for realizing high density of electronic circuits and the like, it is preferable to use an ink jet printing method or a reverse printing method.

As the above ink jet printing method, an apparatus generally called an ink jet printer can be used. Specific examples thereof include Konica-Minolta EB100, XY100(Konica-Minolta IJ Co., Ltd.), Dimatix-Material Printer DMP-3000, and Dimatix-Material Printer DMP-2831 (Fuji film Co., Ltd.).

As the reverse printing method, a relief reverse printing method and a gravure reverse printing method are known, and examples thereof include a method in which the fluid is applied to the surface of various blankets and brought into contact with a plate having a non-image area protruding therefrom, and the fluid corresponding to the non-image area is selectively transferred to the surface of the plate, thereby forming the pattern on the surface of the blanket or the like, and then the pattern is transferred to (on) the support (a).

Further, a pad printing method is known as pattern printing on a three-dimensional molded product. This is a method in which a printing ink is placed on a gravure plate, the printing ink is scraped by a doctor blade to uniformly fill the concave portion, a silicone rubber or urethane rubber gasket is pressed against the plate on which the printing ink is placed, and a pattern is transferred to the gasket, thereby transferring the pattern to a three-dimensional molded product.

The mass per unit area of the metal nanoparticle layer (C) is preferably 1mg/m ²Above 30000mg/m ²Hereinafter, more preferably 1mg/m ²Above 5000mg/m ²The following. The thickness of the metal nanoparticle layer (C) can be controlled by controlling the treatment time in the plating step in forming the metal plating layer (D),The current density, the amount of the plating additive used, and the like.

The metal plating layer (D) constituting the laminate of the present invention is a layer provided for the purpose of forming a highly reliable wiring pattern capable of maintaining good electrical continuity without causing disconnection or the like for a long period of time when the laminate is used for a printed wiring board or the like, for example.

The metal plating layer (D) is a layer formed on the metal nanoparticle layer (C), and is preferably formed by plating. Examples of the plating treatment include a wet plating method such as an electrolytic plating method and an electroless plating method, which can easily form the metal plating layer (D). In addition, 2 or more of these plating methods may be combined. For example, the metal plating layer (D) may be formed by performing electroless plating and then electrolytic plating.

The electroless plating method is a method of forming an electroless plating layer (coating) of a metal coating by bringing an electroless plating solution into contact with a metal constituting the metal nanoparticle layer (C) to deposit a metal such as copper contained in the electroless plating solution.

Examples of the electroless plating solution include a plating solution containing a metal such as copper, nickel, chromium, cobalt, tin, gold, or silver, a reducing agent, and a solvent such as an aqueous medium or an organic solvent.

Examples of the reducing agent include dimethylaminoborane, hypophosphorous acid, sodium hypophosphite, dimethylamine borane, hydrazine, formaldehyde, sodium borohydride, phenol, and the like.

Further, as the electroless plating solution, those containing monocarboxylic acids such as formic acid and acetic acid; dicarboxylic acid compounds such as malonic acid, succinic acid, adipic acid, maleic acid, and fumaric acid; hydroxycarboxylic acid compounds such as malic acid, lactic acid, glycolic acid, gluconic acid, and citric acid; amino acid compounds such as glycine, alanine, iminodiacetic acid, arginine, aspartic acid, and glutamic acid; and organic acids such as aminopolycarboxylic acid compounds such as iminodiacetic acid, nitrilotriacetic acid, ethylenediamine diacetic acid, ethylenediamine tetraacetic acid, and diethylenetriamine pentaacetic acid, and soluble salts (sodium salts, potassium salts, ammonium salts, etc.) of these organic acids, and amine compounds such as ethylenediamine, diethylenetriamine, and triethylenetetramine.

The electroless plating solution is preferably used under the conditions of 20 ℃ to 98 ℃.

The electrolytic plating method is, for example, a method of forming an electrolytic plating layer (metal film) by depositing a metal such as copper contained in an electrolytic plating solution on a conductive material constituting the metal nanoparticle layer (C) provided on a cathode or on the surface of an electroless plating layer (film) formed by the electroless plating treatment by applying an electric current in a state where the electrolytic plating solution is brought into contact with the metal constituting the metal nanoparticle layer (C) or the surface of the electroless plating layer (film) formed by the electroless plating treatment.

Examples of the electrolytic plating solution include a plating solution containing a sulfide of a metal such as copper, nickel, chromium, cobalt, or tin, sulfuric acid, and an aqueous medium. Specifically, a plating solution containing copper sulfate, sulfuric acid and an aqueous medium is exemplified.

The electrolytic plating solution is preferably used in the range of 20 ℃ to 98 ℃.

As a method for forming the metal plating layer (D), a method of performing electroless plating and then electrolytic plating is preferable from the viewpoint of easily controlling the film thickness of the metal plating layer (D) to a desired film thickness from a thin film to a thick film.

The film thickness of the metal plating layer (D) is preferably in the range of 1 μm to 50 μm. The film thickness of the metal plating layer (D) can be adjusted by controlling the processing time, current density, and amount of plating additive used in the plating process when forming the metal plating layer (D).