KR102119002B1 - Metal nanoparticle ink for flexographic printing and manufacturing method of laminate using same - Google Patents

Abstract

The present invention is a metal nanoparticle ink for flexographic printing containing a complex of metal nanoparticles (A) and an organic compound (B) and an aqueous medium (C) containing water and monoalcohols having 1 to 3 carbon atoms. It provides a metal nanoparticle ink for flexographic printing, characterized in that the content of the monoalcohol having 1 to 3 carbon atoms in the aqueous medium (C) is 45% by mass or more.
When the ink is printed on a substrate that is difficult to absorb a solvent, it is difficult to generate splashes of the ink, and it is possible to stably produce a highly accurate and uniform pattern.

Description

Metal nanoparticle ink for flexographic printing and manufacturing method of laminate using same

The present invention relates to a metal nanoparticle ink for flexographic printing that can be used in the manufacture of electronic circuits, antenna wiring, electromagnetic shields, and the like.

In recent years, with the increase in size, size, and thickness of electronic devices, high density and thinning of electronic circuits and integrated circuits used therein have been strongly demanded.

In addition, in recent years, the process of efficiently producing electronic circuits and integrated circuits by continuously printing roll-to-roll on film substrates, etc., is also called printed electronics, and development has been active, and flexo printing is a method for printing at high speed. Law is gaining attention as a useful tool. However, in the case of the flexographic printing method, since printing at a high speed is essential at a printing speed of 20 to 200 m/min, in the printing of the metal nanoparticle ink described later, many defects of the print due to the frying of the ink occur. , It is not leading to practical use.

As a metal nanoparticle ink that can be used for the production of the above-mentioned electronic circuits, for example, conductivity using flexographic printing on a cellulose substrate using a conductive water-based ink comprising water, conductive particles, water-soluble resin, surfactant, and antifoaming agent A method of forming a pattern has been proposed (for example, see Patent Document 1). However, with this method, when printing and patterning ink on an organic film substrate that is difficult to absorb an ink solvent, the frying of the ink or the metal nanoparticles become non-uniform due to the coffee stain phenomenon, and a uniform pattern cannot be printed. There was a problem.

In addition, a method of flexo printing on an organic film using a conductive ink containing silver particles, water, or resin has been proposed (for example, see Patent Document 2). However, since this method also has a high water content in the conductive ink, it is difficult to form the conductive pattern with high precision by generating frying of the ink.

Therefore, even if it is used for a substrate that is difficult to absorb a solvent, there is a need for a metal ink for flexographic printing that is difficult to generate frying of ink and can stably produce a high precision and uniform pattern.

Japanese Patent Application No. 2015-72914 Japanese Patent Application No. 2010-268073

The problem to be solved by the present invention is that when printing on a substrate that is difficult to absorb a solvent, it is difficult to generate an ink splash, and a metal nanoparticle ink for flexographic printing that can stably produce a high precision and uniform pattern is produced. It also provides a method for producing a laminate using the ink.

The present inventors, as a result of earnest research to solve the above problems, by increasing the alcohol content in the aqueous medium contained in the metal nanoparticle ink for flexographic printing, it is possible to stably produce a high precision, uniform pattern Found and completed the present invention.

That is, the present invention is a metal nanoparticle ink for flexographic printing containing a complex of metal nanoparticles (A) and an organic compound (B) and an aqueous medium (C) containing water and monoalcohols having 1 to 3 carbon atoms. To provide a metal nanoparticle ink for flexographic printing, characterized in that the content of the monoalcohol having 1 to 3 carbon atoms in the aqueous medium (C) is 45% by mass or more.

In addition, the present invention is a method for producing a laminate, characterized in that the metal nanoparticle ink for flexographic printing is printed on a substrate surface by a flexo printing method, a resin having a reactive functional group (Y) on the substrate surface (d After forming the primer layer (D) containing ), the organic compound (B) has a reactive functional group (X) to form a bond by reacting with the reactive functional group (Y) The metal nanoparticle ink for flexographic printing On the surface of the ink layer formed of a metal nanoparticle ink for flexographic printing of a laminate obtained by a method for producing a laminate, and moreover, a laminate obtained by printing by a flexographic printing method, It also provides a method of manufacturing a laminate, characterized in that a metal plating layer (E) is formed by electroless plating and/or electrolytic plating.

When the metal nanoparticle ink for flexographic printing of the present invention is used, even if the metal nanoparticle ink containing metal particles is printed on the surface of a substrate that does not absorb a solvent, such as an organic film, it is difficult to splash, stably high precision Patterns of metal nanoparticles can be prepared. In addition, by flexographic printing, it is possible to continuously print roll-to-roll onto the substrate, and a pattern of metal nanoparticles can be produced with high efficiency. Therefore, the metal nanoparticle ink for flexographic printing of the present invention is, for example, an electronic circuit that has been densified by lamination, an inorganic or organic solar cell that needs to be bonded to other members, an organic EL device, an organic transistor, or a flexible print. It can be suitably used in the manufacture of various electronic members such as each layer constituting RFID, such as a substrate, a non-contact IC card, peripheral wiring members, and electromagnetic shields.

1 is a schematic diagram when printing a metal nanoparticle ink for flexographic printing with a straight line parallel to the printing direction.
Figure 2 is a schematic diagram when printing a straight line that is perpendicular to the printing direction of the metal nanoparticle ink for flexographic printing.
3 is a schematic diagram when printing a solid part with a metal nanoparticle ink for flexographic printing.

The metal nanoparticle ink for flexographic printing of the present invention contains a complex of metal nanoparticles (A) and an organic compound (B), and an aqueous medium (C) containing water and a monoalcohol having 1 to 3 carbon atoms. As a metal nanoparticle ink for flexographic printing, the content of the monoalcohol having 1 to 3 carbon atoms in the aqueous medium (C) is 45% by mass or more.

As said metal nanoparticle (A), a transition metal or its compound is mentioned. Among these, transition metals are preferable, and examples thereof include copper, silver, gold, nickel, palladium, platinum, and cobalt. Moreover, among these transition metals, copper, silver, and gold are preferable because they have low electrical resistance and can form metal nanoparticle patterns resistant to corrosion, and silver is more preferable. In addition, when the metal nanoparticle ink for flexographic printing of the present invention is used as a catalyst for electroless plating described later, it is preferable to use silver and/or palladium as the metal nanoparticles (A).

As the average particle diameter of the metal nanoparticles (A), since a fine metal nanoparticle pattern can be formed and the resistance value can be further reduced, the range of 1 to 100 nm is preferable, and the range of 1 to 50 nm is more desirable. In addition, in this invention, "average particle diameter" is the volume average value measured by diluting the said metal nanoparticle (A) with a dispersion good solvent and measuring by dynamic light scattering method. This average particle diameter can be measured, for example, with "NanoTrack UPA-150" manufactured by Nikkiso Corporation.

As the organic compound (B), since the dispersibility of the metal nanoparticles in an aqueous medium is improved, it is preferable to have a cationic group or anionic group. As said cationic group, an amino group, a quaternary ammonium base, etc. are mentioned, for example. Moreover, as said anionic group, a carboxyl group, a carboxylate group, a phosphoric acid group, a phosphorous acid group, a sulfonic acid group, a sulfonate group, a sulfinic acid group, a sulfenic acid group etc. are mentioned, for example.

About the complex with the said metal nanoparticle (A) using the said organic compound (B) which has the said anionic group, it is obtained by the method of description of Unexamined-Japanese-Patent No. 5648232, for example.

Moreover, as said organic compound (B), the compound which has both the functional group and hydrophilic group coordinated with a metal is preferable.

Examples of the functional group coordinated to the metal include a pyridinium group, a triphenylphosphine group, a nitric acid group, a carboxy group, an acetylacetonato group, an amino group, a thiol group, a thioether group, and a thiocyanate group. . Among these, an amino group or a carboxy group is preferable because it has a high coordination power to the metal and is easily detached from the metal after printing, and an amino group or a carboxy group in a three-dimensional configuration capable of double-coordination with the metal is preferable.

Examples of the hydrophilic group include a nonionic group other than the anionic group and cationic group. Examples of the nonionic group include polyoxyalkylene chains, polyvinyl alcohol chains, polyvinylpyrrolidone chains, etc., and polyoxyethylene chains are preferred because of their high affinity for water.

The complex with the metal nanoparticles (A) using the organic compound (B) having a polyethyleneimine chain and a polyoxyethylene chain is obtained, for example, by the method described in Japanese Patent No. 5,564,029. In addition, in the case of this organic compound (B), the amino group (imino group) in the polyethyleneimine chain functions as a cationic group.

Moreover, when using what formed the primer layer (D) mentioned later as a base material on the surface of a base material, as the said organic compound (B), the reactive functional group (Y) which resin (d) used for the said primer layer (D) has. It is preferable to have a reactive functional group (X) that reacts with to form a bond.

Examples of the functional group (X) include carboxyl groups, isocyanate groups, block isocyanate groups, epoxy groups, hydroxyl groups, oxazoline groups, N-methylol groups, N-alkoxymethylol groups, amino groups, and alkoxysilyl groups. Moreover, the said organic compound (B) may have 2 or more types of these functional groups.

When the functional group (X) is an amino group, the organic compound having the polyethyleneimine chain as the organic compound (B) can be used to make the amino group (imino group) in the polyethyleneimine chain as the functional group (X).

Moreover, the acrylic resin which polymerized the acrylic monomer which has the said functional group (X) can also be used as the said organic compound (B) which has the said functional group (X).

When the functional group (X) is a carboxy group, as a raw material for the acrylic resin, for example, (meth)acrylic acid, β-carboxyethyl (meth)acrylate, 2-(meth)acryloyl propionic acid, crotonic acid, ita Conic acid, maleic acid, fumaric acid, itaconic acid half ester, maleic acid half ester, maleic anhydride, itaconic anhydride, citraconic anhydride, β-(meth)acryloyloxyethylhydrogen succinate, citraconic acid, sheet Raconic acid half ester, anhydrous citraconic acid, and the like are used.

When the functional group (X) is an isocyanate group, as a raw material for the acrylic resin, for example, a monomer having a block isocyanate group such as "Carens MOI-BM" manufactured by Showa Denko Co., Ltd. is used.

When the functional group (X) is an epoxy group, as a raw material for the acrylic resin, for example, a monomer having an epoxy group such as glycidyl (meth)acrylate or allyl glycidyl ether is used.

When the functional group (X) is a hydroxyl group, a monomer having a hydroxyl group such as 2-hydroxyethyl (meth)acrylate is used as a raw material for the acrylic resin.

When the functional group (X) is an oxazoline group, a monomer having an oxazoline group such as 2-isopropenyl-2-oxazoline is used as a raw material for the acrylic resin.

When the functional group (X) is an N-methylol group, a monomer having an N-methylol group such as N-methylol (meth)acrylamide is used as a raw material for the acrylic resin.

When the functional group (X) is an N-alkoxymethylol group, as a raw material for the acrylic resin, for example, N-methoxymethylol (meth)acrylamide, N-ethoxymethylol (meth)acrylamide, N -Propoxymethylol (meth)acrylamide, N-isopropoxymethylol (meth)acrylamide, Nn-butoxymethylol (meth)acrylamide, N-isobutoxymethylol (meth)acrylamide, N- Monomers having N-alkoxymethylol groups such as pentoxymethylol (meth)acrylamide are used.

When the functional group (X) is an amino group, a monomer having an amino group such as N,N-dimethylaminoethyl methacrylate is used as a raw material for the acrylic resin.

When the functional group (X) is an alkoxysilyl group, a monomer having an alkoxysilyl group such as 3-methacryloxypropyltrimethoxysilane is used as a raw material for the acrylic resin.

The said acrylic resin may copolymerize with the acrylic monomer other than the monomer which has the said functional group.

As the method for producing the acrylic resin, it can be produced by a known method. Among them, a solution polymerization method is preferable because it improves the dispersion stability of the metal nanoparticles.

In addition, in this invention, "(meth)acrylate" means one or both of acrylate and methacrylate, and "(meth)acrylamide" means one or both of acrylamide and methacrylamide. .

Examples of the method for producing the composite of the metal nanoparticles (A) and the organic compound (B) used in the present invention include the methods described in Japanese Patent No. 5648232, Japanese Patent No. 5,564,291, and the like. In addition, the powder of the complex of the metal nanoparticles (A) and the organic compound (B) is obtained by freeze-drying the aqueous dispersion of the complex.

The aqueous medium (C) used in the present invention contains water and a monoalcohol having 1 to 3 carbon atoms, and the content of the monoalcohol having 1 to 3 carbon atoms contained therein is 45% by mass or more.

Examples of the monoalcohol having 1 to 3 carbon atoms include methanol, ethanol, n-propanol and isopropanol. By using these monoalcohols, it is possible to suppress frying of the ink and non-uniformity of the metal nanoparticles due to the coffee stain phenomenon.

Although the content of the monoalcohol having 1 to 3 carbon atoms in the aqueous medium (C) is 45% by mass or more, the range of 45 to 95% by mass is preferable. Moreover, in order to print with the content rate of the metal nanoparticles of the ink mentioned later or the ink viscosity at that time, the content rate of the said monoalcohol is more preferably 60 to 90 mass %.

In addition, in the aqueous medium (C), alcohol solvents such as ethyl carbitol, ethyl cellosolve, and butyl cellosolve, if necessary, in addition to the above water and monoalcohol having 1 to 3 carbon atoms; Ketone solvents such as acetone and methyl ethyl ketone; Alkylene glycol solvents such as ethylene glycol, diethylene glycol, propylene glycol, and butyl glycol; glycerin; Alkyl ethers of polyalkylene glycols; You may use water-soluble solvents, such as lactam solvents, such as N-methyl-2-pyrrolidone.

The content of the metal nanoparticles (A) used in the present invention in the ink is preferably in the range of 1 to 60% by mass. Moreover, when forming the metal plating layer (E) in the plating processing process mentioned later, the content rate of the ink of the metal nanoparticles (A) can further suppress the adverse effect on the metal plating layer obtained in the plating processing process, 1 to The range of 20 mass% is more preferable.

The viscosity of the metal nanoparticle ink for flexographic printing of the present invention is preferably in the range of 0.1 to 300 mPa·s. In addition, when forming the metal plating layer (E) in the plating process described later, as described above, the content in the ink of the metal nanoparticles (A) is preferably in the range of 1 to 20% by mass, and for flexo printing at this time The viscosity of the metal nanoparticle ink is preferably in the range of 0.1 to 25 mPa·s. Moreover, since the viscosity of the metal nanoparticle ink for flexographic printing becomes easy to follow fine irregularities of the base material, the range of 0.1 to 10 mPa·s is more preferable. Even if the viscosity of the ink is in such a low range, the metal nanoparticle ink for flexographic printing of the present invention contains a certain amount of a predetermined monoalcohol, thereby suppressing the frying of the ink and the non-uniformity of the metal nanoparticles due to coffee stain phenomenon. can do.

In addition, the viscosity of the ink in the present invention is a value measured with an E-type viscometer (measurement temperature: 25°C, contortor: 1°34' x R24, rotation speed: 50 rpm).

The metal nanoparticle ink for flexographic printing of the present invention comprises the dispersion stability of the composite of the metal nanoparticles (A) and the organic compound (B) in an aqueous medium (C), a base material or a primer layer (D) described below. From the viewpoint of improving the wettability of the resin (d) to be formed on the surface of the coating film, etc., a pH adjusting agent, a surfactant, an antifoaming agent, a rheology adjusting agent, a leveling agent, etc. may be used as necessary.

The metal nanoparticle ink for flexographic printing of the present invention may be directly printed on a substrate that is an object to be printed to form a laminate, but by forming a primer layer (D) on the substrate surface in advance and printing on the surface, the substrate and It is preferable because a laminate having improved adhesion to the ink layer can be obtained.

Examples of the substrate include polyimide resin, polyamideimide resin, polyamide resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polycarbonate resin, acrylonitrile-butadiene-styrene (ABS) resin, and poly(metha) ) Acrylic resins such as methyl acrylate, polyvinylidene fluoride resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, polycarbonate resin, polyethylene resin, polypropylene resin, urethane resin, liquid crystal polymer (LCP), Polyether ether ketone (PEEK) resins, polyphenylene sulfide (PPS) resins, polyphenylene sulfone (PPSU) resins, cellulose nanofibers, silicon, ceramics, substrates made of glass, etc., porous substrates made of them, Substrates made of a metal such as a steel sheet or copper, and substrates on which their surfaces are deposited with silicon carbide, diamond-like carbon, aluminum, copper, titanium, or the like can be used. In addition, when a conductive material is used for the substrate, the primer layer (D) to be described later can be used as the substrate in the present invention by forming it as an insulating layer on its surface.

In addition, when the laminate produced by the present invention is used for a circuit board or the like, polyimide, polyethylene terephthalate, polyethylene naphthalate, liquid crystal polymer (LCP), polyether ether ketone (PEEK), glass, cellulose nanofiber It is preferable to use a substrate made of or the like.

Moreover, when using the laminated body manufactured by this invention for the application which requires flexibility, it is preferable to use a film-like or sheet-like substrate rich in flexibility as said base material.

As said film-like or sheet-like base material, a polyethylene terephthalate film, a polyimide film, a polyethylene naphthalate film, etc. are mentioned, for example.

In addition, as the film-like or sheet-like base material, since it is possible to realize weight reduction and thinning of the laminate produced by the present invention, it is preferable that the thickness is 1 to 2,000 µm, more preferably 1 to 100 µm. desirable. Further, when more flexibility is required, it is more preferable that the thickness is 1 to 80 µm.

It is preferable that the resin (d) forming the primer layer (D) has the functional group (Y) forming a chemical bond by reacting with the functional group (X) contained in the organic compound (B), The resin species is not limited, but urethane resin, acrylic resin, or a combination thereof is preferred. Moreover, the said resin (d) can be used individually by 1 type and can also use 2 or more types together.

In addition, examples of the functional group (Y) include carboxyl groups, isocyanate groups, block isocyanate groups, epoxy groups, hydroxyl groups, oxazoline groups, N-methylol groups, N-alkoxymethylol groups, amino groups, and alkoxysilyl groups. have. Moreover, the said resin (d) may have 2 or more types of these functional groups. Moreover, the said carboxy group may be derived from an acid anhydride. Further, the amino group may be any of primary to tertiary amino groups.

As the resin (d), for example, those described in Japanese Patent No. 5,238,279 can be used. Moreover, about the method of introduce|transducing the said functional group (Y) to the said resin (d), the method of the said publication can be used.

It is preferable that the reactive functional group (X) of the organic compound (B) and the reactive functional group (Y) of the resin (d) react efficiently to form a bond. As the combination, when the functional group (X) is a carboxy group, the functional group (Y) is preferably an epoxy group, and when the functional group (X) is an isocyanate group or a block isocyanate group, the functional group (Y) is preferably a hydroxyl group or an amino group. And, when the functional group (X) is an epoxy group, the functional group (Y) is preferably a carboxy group or an amino group, and when the functional group (X) is an oxazoline group, the functional group (Y) is preferably a carboxy group, and the functional group ( When X) is a hydroxyl group, the functional group (Y) is preferably an isocyanate group or a block isocyanate group, and when the functional group (X) is a methylol group or an N-alkoxymethyl group, the functional group (Y) is a methylol group or N-alkoxy A methylol group and an amino group are preferred, and when the functional group (X) is an amino group, the functional group (Y) is preferably an epoxy group, an isocyanate group, a block isocyanate group, an N-methylol group, an N-alkoxymethylol group, and the functional group ( When X) is an alkoxysilyl group, the functional group (Y) is preferably an alkoxysilyl group.

As a method of printing the metal nanoparticle ink for flexo printing of the present invention on the surface of a base material or a primer layer (D) formed on a base material, flexo using a flexible rubber-like plate in terms of simple printing and printing The printing method is preferred.

In the flexographic printing method, anilox rolls are used to uniformly transfer ink to the plate, but by controlling the number of lines of the anilox rolls, the film thickness of the ink layer after printing and drying can be adjusted. have. For example, when the metal nanoparticle ink for flexographic printing of the present invention is used as a plating catalyst for electroless plating to be described later, the film thickness of the ink layer is preferably 100 nm or less. In order to make this film thickness, the number of lines of the anilox roll is preferably in the range of 160 to 600 lines/cm, and more preferably in the range of 200 to 400 lines/cm. Further, the cell volume is preferably in the range of 2 to 6 cm 3 /m 2.

In addition, in the flexographic printing method, the printing speed is preferably adjusted in the range of 20 to 200 m/min, and when printing quality and productivity are considered, the printing speed is preferably in the range of 30 to 150 m/min. Do. In this case, the conveyance of the base material may be conveyed in a single sheet, but in the case of a continuous base material such as a film base material wound with a roll, it may also be conveyed in roll-to-roll.

The resin (d) contained in the primer layer (D) by printing the metal nanoparticle ink for flexographic printing of the present invention on the surface of the primer layer (D) formed on the substrate, and then performing heat treatment as necessary. ) Has the functional group (Y) and the functional group (X) of the organic compound (B) contained in the flexographic printing metal nanoparticle ink reacts, and thus the interlayer between the primer layer (D) and the ink layer Can further improve the adhesion.

It is preferable to perform the temperature of the said heat treatment in 50-300 degreeC for 2 to 200 minutes. The heat treatment may be performed in the atmosphere, but since the oxidation of the metal nanoparticles (A) in the conductive layer can be prevented, part or all of the heating step may be performed in a reducing atmosphere.

In addition, the said heat treatment can be performed by an oven, a hot-air drying furnace, an infrared drying furnace, laser irradiation, microwave, light irradiation, etc., for example.

To the surface of the ink layer of the laminate obtained by printing the metal nanoparticle ink for flexographic printing of the present invention on the surface of a base material or a primer layer (D) formed on a base material, for further electroless plating and/or electrolytic plating It can also be set as the laminated body in which the metal plating layer (E) was formed. Here, electroless plating and electrolytic plating may be performed individually, but electrolytic plating may be performed after electroless plating.

The electroless plating and electrolytic plating forming the metal plating layer (E) can be performed by a known method.

Even if the laminate obtained by the production method of the present invention is subjected to a plating treatment step, the conductive layer does not peel off from the primer layer (D), can maintain good electrical conductivity, and has excellent durability. Suitable for the formation of circuit boards used in circuits, integrated circuits, etc., organic solar cells, electronic book terminals, organic ELs, organic transistors, flexible printed circuit boards, RFID, etc. do. In particular, since the laminate subjected to the plating treatment does not generate disconnection or the like over a long period of time, it is possible to maintain good electrical conductivity and form a highly reliable wiring pattern. For example, a flexible printed circuit board (FPC) ), tape automatic bonding (TAB), chip-on film (COF), printed wiring boards (PWB), and the like can be used for applications commonly referred to as copper clad laminate (CCL).

(Example)

Hereinafter, the present invention will be described in detail by examples.

[Production Example 1: Preparation of anionic silver nanoparticles]

Into a 4-necked flask equipped with a thermometer, stirrer, dropping funnel, nitrogen introduction tube, and reflux cooler, 32 parts by mass of methyl ethyl ketone (hereinafter MEK) and 32 parts by mass of ethanol were introduced and heated to 80° C. while stirring in a nitrogen stream. did. Next, 20 parts by mass of phosphooxyethyl methacrylate, 70 parts by mass of methoxy polyethylene glycol methacrylate (molecular weight 1,000), 10 parts by mass of glycidyl methacrylate, 4.1 parts by mass of methyl mercaptopropionate, and 80 parts by mass of MEK Mixture consisting of parts, and 0.5 parts by weight of polymerization initiator (Wakojunyaku Co., Ltd. product "V-65", 2,2'-azobis (2,4-dimethylvaleronitrile)), 5 parts by weight of MEK Each was dripped over 2 hours. After completion of the dropwise addition, 0.3 parts by mass of a polymerization initiator ("Perbutyl O" manufactured by Nichi Oil Co., Ltd.) was added twice every 4 hours, followed by stirring at 80 DEG C for 12 hours. Water was added to the obtained resin solution to emulsify the whole phase. ), and then desorbed under reduced pressure, water was added to adjust the concentration to obtain an aqueous solution of an acrylic polymer having a glycidyl group having a non-volatile content of 76.8% by mass.Weight measured by gel permeation chromatography of the resin. The average molecular weight was 4,200 in terms of polystyrene, and the acid value was 96.2 mgKOH/g.

A reducing agent solution comprising 5.56 g (53.0 mmol) of 85% by mass N,N-diethylhydroxylamine, the acrylic polymer obtained above (equivalent to 106 mg of nonvolatiles), and 15 g of water was prepared. Separately, the acrylic polymer (equivalent to 106 mg of non-volatile matter) obtained above was dissolved in 5 g of water, and a solution in which 6 g (35.3 mmol) of silver nitrate was dissolved in 10 g of water was added and stirred well. The above reducing agent solution was added dropwise to this mixture at room temperature (25°C) over 2 hours. The obtained reaction mixture was concentrated at 40° C. under reduced pressure (1 Torr) for 4 hours, and an aqueous dispersion of silver nanoparticles having a nonvolatile content of about 30% by mass was obtained. The particle diameter of the silver nanoparticles was estimated from 10 to 40 nm from the TEM image. In addition, the dispersion was left to stand in a freezer at -40°C for one day and frozen, and this was treated with a freeze dryer ("FDU-2200" manufactured by Tokyo Rikakikai Co., Ltd.) for 24 hours, thereby allowing silver nanoparticles and anionic groups (phosphoric acid groups). ) And an anionic silver nanoparticle consisting of a lump of grayish metal flake flakes, which is a complex with an organic compound having a glycidyl group.

[Production Example 2: Preparation of cationic silver nanoparticles]

In accordance with Example 1 described in Japanese Patent No. 4573138, cationic silver nanoparticles composed of a grayish green metallic shiny flake mass, which is a complex of silver nanoparticles and an organic compound having a cationic group (amino group), are prepared. Got.

[Production Example 3: Preparation of resin for primer layer having carboxyl group]

In a reaction vessel equipped with a stirrer, reflux cooling tube, nitrogen introduction tube, thermometer, and dropping funnel, 450 parts by mass of methyl ethyl ketone, 46 parts by mass of methyl methacrylate, 45 parts by mass of n-butyl acrylate, and 9 mass of methacrylic acid After adding 5 parts by mass of 100 parts by mass of the acrylic monomer mixture in which the parts were mixed, 0.5 parts by weight of benzoyl peroxide was added. Then, while maintaining the temperature in the reaction vessel at 80°C, 95 parts by mass of the remainder of the acrylic monomer mixture was added dropwise over 120 minutes to polymerize, thereby obtaining a methyl ethyl ketone solution of a primer layer-containing resin having a carboxy group.

[Production Example 4: Preparation of resin for primer layer having glycidyl group]

In a reaction vessel equipped with a stirrer, reflux cooling tube, nitrogen introduction tube, thermometer and dropping funnel, 450 parts by mass of methyl ethyl ketone, 46 parts by mass of methyl methacrylate, 45 parts by mass of n-butyl acrylate, glycidyl methacryl After adding 5 parts by mass of 100 parts by mass of the acrylic monomer mixture in which 9 parts by mass of the rate was mixed, 0.5 parts by weight of benzoyl peroxide was added. Then, while maintaining the temperature in the reaction vessel at 80°C, 95 parts by mass of the remainder of the acrylic monomer mixture was added dropwise over 120 minutes to polymerize, thereby obtaining a methyl ethyl ketone solution of the primer layer resin having a glycidyl group.

[Example 1]

By mixing 5 g of anionic silver nanoparticles obtained in Production Example 1, 45 g of ethanol, 29 g of ion-exchanged water, and a leveling agent ("KF-351A" manufactured by Shinko Silicone Co., Ltd.) and stirring for 3 hours, flexo printing A metal nanoparticle ink 1 was prepared (69% by mass alcohol content of 1 to 3 carbon atoms in an aqueous medium, 4.7% by mass silver content, and 1.0mPa·s viscosity).

On the surface of the polyimide film ("Kapton150ENC" manufactured by Toray Dupont Co., Ltd., 50 µm thick), the metal nanoparticle ink 1 for flexographic printing obtained above was applied to a flexographic printing machine ("Plexix, manufactured by Matsuo Sangyo Co., Ltd."). Proof 100”), the pad portion of a square solid having 2 mm on one side is connected to both ends of a straight line parallel to the printing direction having a line width of 100 µm and a length of 64 mm, and the pad sections are set to 1 mm with 20 pad sections. The listed pattern (FIG. 1), the pattern of FIG. 1 as a straight line orthogonal to the printing direction (FIG. 2), and a square solid pattern (FIG. 3) with one side of 60 mm were printed at a printing speed of 50 m/min. Then, it dried at 120 degreeC for 10 minutes, and the laminated body was obtained.

[Example 2]

By mixing 5 g of cationic silver nanoparticles obtained in Production Example 2, 63 g of methanol, 29 g of ion-exchanged water, 3 g of glycerin, and 0.1 g of a leveling agent ("KF-351A" manufactured by Shinko Silicone Co., Ltd.) and stirred for 3 hours, A metal nanoparticle ink 2 for flexographic printing (68% by mass of the alcohol content of 1 to 3 carbon atoms in an aqueous medium, 4.8% by mass of the silver content, and a viscosity of 1.5 mPa·s) was prepared. Using the obtained metal nanoparticle ink for flexo printing (2), the same procedure as in Example 1 was carried out to obtain a laminate.

[Example 3]

To the surface of the polyimide film ("Kapton150ENC" manufactured by Toray and DuPont Co., Ltd., 50 mu m thick) so that the methyl ethyl ketone solution of the resin for the primer layer having the carboxyl group obtained in Production Example 3 had a dry film thickness of 0.3 mu m, Coating was performed using a spin coater and dried at 80°C for 3 minutes using a hot air dryer to obtain a base material on which a primer layer was formed.

By mixing with 5 g of anionic silver nanoparticles obtained in Production Example 1, 30 g of ethanol, 30 g of isopropanol, 30 g of ion-exchanged water, and 0.1 g of a leveling agent ("KF-351A" manufactured by Shinko Silicone Co., Ltd.) and stirred for 3 hours, A metal nanoparticle ink 3 for flexographic printing (63% by mass alcohol content of 1 to 3 carbon atoms in an aqueous medium, 4.7% by mass silver content, and viscosity of 1.0 mPa·s) was prepared.

The obtained metal nanoparticle ink 3 for flexo printing was printed in the same manner as in Example 1 on the surface of the primer layer of the base material on which the obtained primer layer was formed. Then, drying was performed at 120°C for 10 minutes to obtain a laminate in which the carboxyl group in the primer layer of the substrate reacted with the glycidyl group in the anionic silver nanoparticles.

[Comparative Example 1]

By mixing 5 g of anionic silver nanoparticles obtained in Production Example 1, 9 g of ethanol, 86 g of ion-exchanged water, and a leveling agent ("KF-351A" manufactured by Shinko Silicone Co., Ltd.) and stirring for 3 hours, flexo printing A metal nanoparticle ink (R1) (an alcohol content of 1 to 3 carbon atoms in an aqueous medium was 9% by mass, a silver content of 4.5% by mass, and a viscosity of 1.0 mPa·s) was prepared.

The ink R1 obtained above was printed on the surface of the primer layer of the substrate on which the primer layer obtained in the same manner as in Example 3 was formed, as in Example 1. Then, drying was performed at 120°C for 10 minutes to obtain a laminate in which the carboxyl group in the primer layer of the substrate reacted with the glycidyl group in the anionic silver nanoparticles.

[Examples 4 to 10 and Comparative Examples 2 to 4]

Using the cationic silver nanoparticles obtained in Production Example 2, except that the composition shown in Tables 2 and 3 was changed, the same procedure as in Example 1 was carried out, and the metal nanoparticle inks for flexographic printing (4) to (10) and (R2) to (R4) were prepared.

Flexo obtained above on the surface of the primer layer of the substrate on which the primer layer obtained in the same manner as in Example 3 was formed, except that the methyl ethyl ketone solution of the primer layer resin having a glycidyl group obtained in Production Example 4 was used. The printing metal nanoparticle inks (4) to (10) and (R2) to (R4) were printed in the same manner as in Example 1. Then, drying was performed at 120°C for 10 minutes to obtain a laminate in which the glycidyl group in the primer layer of the substrate reacted with the amino group in the cationic silver nanoparticles.

[Example 11]

A polyimide film ("Kapton150ENC" manufactured by Toray and Dupont Co., Ltd.) having a thickness of 0.1 mu m of the primer layer after drying the methyl ethyl ketone solution of the primer layer resin having the glycidyl group obtained in Production Example 4, thickness 50 On the surface of µm, length of 1000 m), a small base gravure coater was applied and dried at 80° C. for 3 minutes using a hot air dryer to obtain a roll substrate of a polyimide film having a primer layer.

On the surface of the primer layer of the base material on which the obtained primer layer was obtained, the metal nanoparticle ink 4 for flexographic printing obtained in Example 4 was printed using a flexographic printing machine ("SOLOFLEX" manufactured by WINDMOELLER & HOLSCHER). The printing pattern (FIGS. 1 to 3) was printed 1000 m at 100 m/min, as in Example 1 with roll-to-roll. Then, by drying at 120°C for 10 minutes, a laminate was obtained by reacting glycidyl groups in the primer layer of the substrate and amino (imino) groups in the cationic silver nanoparticles.

[Evaluation of printability]

The laminates obtained in Examples 1 to 11 and Comparative Examples 1 to 4 described above were evaluated for printability by the following method.

[Method for evaluating printing aptitude of ink]

The solid portion of the print pattern (FIG. 3) obtained above was randomly photographed at a magnification of 180 times using a microscope (VHX-900, manufactured by Giens Corporation), and then subjected to binarization treatment to evaluate the proportion of the area where the ink was splashed.

A: The ink did not splash at all.

B: Ink fry in the range of less than 1%.

C: Ink fry in the range of 1% or more and less than 10%.

D: Ink fry in the range of 10% or more and less than 30%.

E: Ink fry in the range of 30% or more.

[Evaluation method of plated film defects]

For the laminates obtained in Examples 1 to 10 and Comparative Examples 1 to 4, the surface of the solid portion of the printed pattern (FIG. 3) obtained above was used as the cathode, and the copper foil was used as the anode to contain copper sulfate. An electrolytic plating solution was used for electrolytic plating at a current density of 2 A/dm ² for 15 minutes to deposit a copper plating layer having a thickness of 8 μm on the surface of the conductive layer. As the electrolytic plating solution, those containing 70 g/L of copper sulfate, 200 g/L of sulfuric acid, 50 mg/L of chlorine ions, and 5 g/L of Topplatin SF (brightener manufactured by Okuno Seiya Kogyo Co., Ltd.) were used. Subsequently, the surface of the plated layer of the solid portion of the printed pattern obtained by laminating the obtained copper plated layer was photographed randomly at a magnification of 180 times using a microscope ("VHX-900" manufactured by Giens Corporation), followed by binarization, The area ratio of the plating film defect was evaluated.

A: There were no defects at all.

B: There was a defect in the range of less than 1%.

C: There was a defect in the range of 1% or more and less than 10%.

D: There was a defect in the range of 10% or more and less than 30%.

E: There was a defect in the range of 30% or more.

The laminate obtained in Example 11 was first immersed in an electroless copper plating solution ("OIC kappa" manufactured by Okuno Seiya Chemical Co., pH 12.5) at 55 DEG C for 20 minutes, and an electroless copper plating film (0.5 µm thick). Formed. Then, the surface of the solid portion of the printed pattern (FIG. 3) was used as a cathode, and copper was used as an anode, and electrolytic plating was performed for 15 minutes at a current density of 2 A/dm ² using an electrolytic plating solution containing copper sulfate, A copper plating layer having a thickness of 8 μm was laminated on the surface of the conductive layer. As the electrolytic plating solution, those containing 70 g/L of copper sulfate, 200 g/L of sulfuric acid, 50 mg/L of chlorine ions, and 5 g/L of Topplatin SF (brightener manufactured by Okuno Seiya Kogyo Co., Ltd.) were used. About the surface of the plating layer of the solid part of the printed pattern which laminated|stacked the obtained copper plating layer, the area ratio of the plating film defect was evaluated like the above.

[Evaluation method of electrical conductivity after lamination of plating layer]

For the laminates obtained in Examples 1 to 10 and Comparative Examples 1 to 4, a pad portion of a square solid having a side width of 2 mm was connected to both ends of a straight line having a line width of 100 µm and a length of 6 cm, obtained above. The current density of 2A/dm using an electrolytic plating solution containing copper sulfate using the surface of the printing pattern (FIG. 1) and the surface of the printing pattern (FIG. 2) in which 20 pads are arranged at 1 mm as the cathode, and the copper foil as the anode. By electrolytic plating for ² minutes for 15 minutes, a copper plating layer having a thickness of 8 µm was laminated on the surface of the conductive layer. As the electrolytic plating solution, those containing 70 g/L of copper sulfate, 200 g/L of sulfuric acid, 50 mg/L of chlorine ions, and 5 g/L of Topplatin SF (brightener manufactured by Okuno Seiya Kogyo Co., Ltd.) were used. Next, an electrode of a tester was placed on the pad portion of two types of printed patterns (FIGS. 1 and 2) on which the obtained copper plating layer was laminated, and the disconnected ratio among 40 (20 x 2 patterns) was evaluated.

The laminate obtained in Example 11 was first immersed in an electroless copper plating solution ("OIC kappa" manufactured by Okuno Seiya Chemical Co., pH 12.5) at 55 DEG C for 20 minutes, and an electroless copper plating film (0.5 µm thick). Formed. Then, the pattern (FIG. 1) in which a pad portion of a square solid having 2 mm on one side was connected to both ends of a straight line having a line width of 100 µm and a length of 6 cm obtained from the above (FIG. 1) and 20 pad portions between 1 mm By using the electrolytic plating solution containing copper sulfate as the anode, using the surface of the pattern (FIG. 2) as the cathode, and copper phosphorus as the anode, electrolytic plating was performed for 15 minutes at a current density of 2 A/dm ² to the surface of the conductive layer. A copper plating layer having a thickness of 8 µm was laminated. As the electrolytic plating solution, those containing 70 g/L of copper sulfate, 200 g/L of sulfuric acid, 50 mg/L of chlorine ions, and 5 g/L of Topplatin SF (brightener manufactured by Okuno Seiya Kogyo Co., Ltd.) were used. Subsequently, among the two types of print patterns (FIGS. 1 and 2) in which the obtained copper plating layers were laminated, one pair of print patterns was arbitrarily selected, and a tester electrode was placed on the pad portion of the print pattern, and 40 ( The disconnected ratio among 20 x 2 patterns) was evaluated.

Tables 1 to 3 summarize the evaluation results such as the composition of the metal nanoparticle ink for flexo printing, the type of resin used for the primer layer (D) formed on the surface of the substrate (described by the number of the manufacturing example), and printability. .

[Table 1]

[Table 2]

[Table 3]

In Examples 1 to 10 using the metal nanoparticle ink of the present invention, it was confirmed that the printability to the surface of the substrate or the primer layer formed on the substrate was good. In addition, Example 11 is an example of using an actual metal flexographic printing machine using the metal nanoparticle ink of the present invention, but it is possible to perform flexo printing by roll-to-roll without problems, and printing It was confirmed that the aptitude was also good.

In addition, it was confirmed that the metal plating layers of Examples 3 to 10 can be laminated without problems by electrolytic plating, and the metal plating layers have a high electrical conductivity. Further, in Example 11, after the metal plating layer was laminated by electroless plating, the metal plating layer was further thickened by electrolytic plating, but similarly, the metal plating layer can be laminated without problems. It was confirmed that the metal plating layer had a high electric conductivity.

On the other hand, the print patterns obtained in Comparative Examples 1 to 4 are examples in which the content of alcohols having 1 to 3 carbon atoms in the aqueous medium (C) is less than 45% by mass. Since these print patterns had poor printability to the base material and the primer layer and bounced immediately after printing, there was a problem that the plated layer of the desired pattern could not be laminated.

Claims (8)

After forming a primer layer (D) containing a resin (d) having a reactive functional group (Y) on the surface of the substrate, a reactive functional group that forms a bond by reacting with the metal nanoparticles (A) and the reactive functional group (Y) For flexographic printing comprising a complex of an organic compound (B) having (X), an aqueous medium (C) comprising water and a monoalcohol having 1 to 3 carbon atoms, and the content of the monoalcohol being 45% by mass or more A method for producing a laminate, characterized in that the metal nanoparticle ink is printed by flexographic printing. According to claim 1,
The manufacturing method of the laminated body whose content rate in the ink of the said metal nanoparticle (A) is the range of 1-20 mass %. The method according to claim 1 or 2,
A method for producing a laminate having a viscosity in the range of 0.1 to 25 mPa·s. The method according to claim 1 or 2,
The said organic compound (B) is a manufacturing method of a laminated body which has a cationic group or an anionic group. The method according to claim 1 or 2,
Method of producing a laminate of the metal nanoparticles (A) is a metal paper, silver, gold, copper or palladium. A metal plating layer (E) on the surface of the ink layer formed of the metal nanoparticle ink for flexographic printing of the laminate obtained by the method for manufacturing the laminate according to claim 1 or 2, and also by electroless plating and/or electrolytic plating. ). delete delete

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