JP6164378B2 - Plating primer composition, substrate to be plated, composite of insulating substrate and metal layer, method of manufacturing substrate to be plated, and method of manufacturing composite of insulating substrate and metal layer - Google Patents

Description

  The present invention relates to a primer composition for plating for forming a metal layer on an insulating substrate by plating treatment, a substrate to be plated having a primer layer for plating, and an insulation obtained by plating the substrate to be plated. The present invention relates to a composite of a conductive substrate and a metal layer and a method for producing them.

  The technology for forming metal layers on insulating substrates such as plastic, glass, and ceramics is widely applied to decorative plating that gives a metal-like texture, electrical circuit formation for electronics mounting, electromagnetic wave shield formation, etc. . On the other hand, these insulating base materials and metal layers are generally difficult to form strong bonds, and in order to obtain good adhesion, the surface of the insulating base material is used for the purpose of utilizing the anchor effect. A method of roughening the film by chemical etching is known. However, the method of roughening the surface is a complicated process using a strong oxidizing agent such as chromic acid or permanganic acid, and there are concerns about the environmental load of these etching agents.

  On the other hand, a method of applying a primer for electroless plating on an insulating substrate has been proposed as a method that does not require a roughening step of the substrate surface. For example, Patent Document 1 discloses a plating that can be applied with a catalyst by using a hydroxyl group formed by hydrolyzing an ester bond of a polymer having a (meth) acrylic acid ester structure after a strong alkaline aqueous solution treatment. Primer compositions have been proposed. However, in this method, it is necessary to perform a complicated process of providing a primer layer on an insulating substrate, performing a pretreatment for applying a catalyst, and further activating the catalyst.

  Patent Document 2 proposes a coating composition for electroless plating containing a composite of palladium particles and a dispersant, a solvent, and a binder resin. In this method, since the palladium particles that serve as a catalyst for electroless plating are directly dispersed, the catalyst activation step can be omitted, and the surface of the concavo-convex structure formed on the surface of the coating film in the drying step of the coating composition can be omitted. It is disclosed that palladium particles are unevenly distributed, an anchor effect is generated by this uneven structure, and the adhesion of the plating film can be improved. However, in this method, since the catalyst is segregated on the surface of the concavo-convex structure generated in the drying process of the coating film, it is difficult to make the density of the catalyst present on the surface uniform, and uneven plating occurs, resulting in a uniform metal layer. There was a possibility of causing trouble in formation. In recent years, the price of palladium catalysts has soared, and the development of alternative catalyst technology has been demanded.

  Patent Document 3 proposes a primer composition for electroless plating characterized by containing colloidal metal particles, a curable composition curable at 120 ° C. or less, and a solvent. In addition to palladium colloid, cheaper silver colloid particles and silver / palladium composite colloid particles are also disclosed. In this proposed technology, the metal colloid is fixed on the non-conductive substrate by curing the curable composition, and the fixed metal colloid becomes an electroless plating nucleus, so that the plating film is also adhered to the substrate. It is explained that it is possible. Therefore, in this method, the adhesion of the plating film on the non-conductive substrate depends on the adhesion between the metal colloid particles that are plating nuclei and the plating film, and in order to improve the adhesion strength. There was a need to improve the adhesion between the curable composition after curing formed on the non-conductive substrate and the plating film.

JP 10-317153 A JP 2014-65909 A JP 2008-07849 A

  In view of the above circumstances, the problem to be solved by the present invention is to form a low-cost, high-adhesion metal layer on an insulating base material by a simple plating process without roughening the surface. Is to provide technology for

  As a result of intensive studies to solve the above problems, the inventors of the present invention are silver and copper nanoparticles that are less expensive than palladium, or composite nanoparticles of silver core-copper shell, The composition containing the blocked isocyanate was found to be effective as a primer layer for forming a highly adhesive metal layer on an insulating substrate by a simple plating treatment, and the present invention was completed. .

That is, the present invention relates to at least one metal nanoparticle (A) selected from the group consisting of silver nanoparticles, copper nanoparticles, silver core-copper shell nanoparticles, and silver-copper anisotropic composite particles, and blocked isocyanate ( B) and a plating primer composition containing a solvent (C), characterized in that the blocked isocyanate (B) is obtained by blocking with phenol isocyanurate of 4,4'-diphenylmethane diisocyanate A primer composition for plating, a substrate to be plated using the primer composition for plating, a composite of an insulating substrate and a metal layer having a plating layer on the substrate to be plated, and the substrate to be plated The manufacturing method of this, and the manufacturing method of the composite_body | complex of an insulating base material and a metal layer are provided.

  According to the present invention, a metal layer that does not require surface roughening, exhibits high adhesion, and has excellent adhesion heat stability can be formed on an insulating substrate by a simple plating process. It shows a particularly remarkable effect. According to the present invention, it becomes possible to easily manufacture a composite having a metal layer on an insulating substrate, and a decorative object having a metal-like texture on resin, glass, ceramics, etc. It can be used for the production of circuits, electromagnetic wave shields and the like.

It is the figure which showed typically the cross-sectional form of the primer layer for plating obtained using the primer composition for plating of this invention. It is the figure which showed typically the cross-sectional form of the primer layer for plating obtained using the primer composition for plating of this invention. It is the figure which showed typically the cross-sectional form of the primer layer for plating obtained using the primer composition for plating of this invention. It is the figure which showed typically the cross-sectional form of the primer layer for plating obtained using the primer composition for plating of this invention. It is the figure which showed typically the cross-sectional form of the primer layer for plating obtained using the primer composition for plating of this invention. It is the figure which showed typically the cross-sectional form of the primer layer for plating obtained using the primer composition for plating of this invention. Scanning electron microscope image (scale bar: 100 nm) of the surface of the primer layer for plating produced in Example 1 Enlarged view (scale bar: 100 nm) of a scanning electron microscope image of the surface of the primer layer for plating produced in Example 1 Scanning electron microscope observation image (scale bar: 100 nm) of the cross section of the primer layer for plating produced in Example 3 Scanning electron microscope image (scale bar: 100 nm) of the surface of the primer layer for plating prepared in Example 3

The contents of the present invention will be specifically described below.
<Insulating base material>
In the present invention, for example, polyimide resin; polyamideimide resin; polyamide resin; polyester resin such as polyethylene terephthalate, polyethylene naphthalate, and liquid crystal polymer; acrylic resin; polycarbonate Cycloolefin polymer; paper phenol; paper epoxy; glass epoxy; ABS resin; glass; Moreover, the said insulating base material can use the thing of any form of a flexible material, a rigid material, and a rigid flexible material. These insulating substrates may be thin films as films, and thick ones may be molded products having complicated shapes in addition to sheets and plates.

  In addition, as the insulating base material used in the present invention, for example, a commercially available material formed into a film, a sheet, or a plate shape may be used, or any shape from a solution, a melt, or a dispersion of the material. You may use the material shape | molded.

  For the insulating base material for flexible use, films such as polyimide, polyamideimide, polyester resin, polyamide, polyphenylene sulfide (PPS), polyetheretherketone (PEEK) can be used, and as commercially available polyimide resins, For example, Kapton (Toray Dupont, registered trademark), Upilex (Ube Industries, registered trademark), Apical (Kaneka, registered trademark), Pomilan (Arakawa Chemical, registered trademark), Neoprim (Mitsubishi Gas Chemical, registered trademark), etc. A film can be suitably used. Examples of commercially available polyester resins include polyethylene terephthalate films such as Lumirror (Toray, registered trademark) and Mylar (Teijin DuPont). Polyethylene naphthalate (Teonex; Teijin DuPont), liquid crystal polymer Bexter series (Kuraray and Bexter are registered trademarks) can also be suitably used. In addition, these films may be used in a state of being cut into a certain size, or may be used in a continuous film state.

  The insulating base material used in the present invention is coated with a plating primer composition for the purpose of improving the adhesion between the insulating base material and the primer layer formed using the plating primer composition of the present invention. Surface treatment may be performed before the treatment. As a surface treatment method for the insulating base material, a known and commonly used method may be appropriately selected. For example, physical methods such as UV treatment, ozone treatment, corona treatment, and plasma treatment can be suitably used. As for these processing methods, one type of method may be performed alone, or a plurality of methods may be combined. Moreover, when the insulating base material is a polyimide resin, a chemical method of treating the surface of the base material of the polyimide resin with an alkaline aqueous solution may be used. When the insulating substrate is a polyester resin, the surface of the polyester resin is preferably subjected to UV treatment, corona treatment, or plasma treatment. These surface treatment methods may be performed singly or in combination of a plurality of methods. These surface treatment methods do not perform roughening on the order of sub-μm to μm as in a normal roughening process, but do not convert the functional groups present on the surface of the insulating substrate or the surface at the nano level. Only irregularities are formed.

<Metal nanoparticles (A)>
The metal nanoparticles (A) used in the present invention have conductivity capable of electroplating in a state where they are assembled in a primer layer for plating described later, and a comparison that functions effectively as a catalyst for electroless plating. It is preferable to use silver or copper nanoparticles or silver and copper composite nanoparticles, that is, silver-copper core-shell particles or silver-copper anisotropic composite particles. Can do. Among these, silver nanoparticles are more preferable. In this invention, the said metal nanoparticle (A) may use only 1 type, and may use what mixed multiple types. Moreover, even if an oxide film or a sulfide film exists on the surface of the metal nanoparticles, it does not matter as long as it functions as an electroless plating catalyst.

  The shape of the metal nanoparticles (A) is not particularly limited as long as it is a shape that is stably dispersed in the primer composition for plating of the present invention, and is spherical, lenticular, polyhedral, flat, rod, wire The metal fine particles having various shapes such as a single shape or a mixture of a plurality of types can be appropriately selected and used according to the purpose.

  As for the size of the metal nanoparticles (A), the particle shape is observed with an electron microscope. When the observation shape is a circle or a polyhedron, the diameter is preferably 1 to 200 nm. From the viewpoint of dispersibility and stability of the metal nanoparticles in the primer composition for plating, it is more preferable to use one having a thickness of 2 to 100 nm. Furthermore, from the viewpoint of the activity of the electroless plating catalyst contained in the conductive primer layer for plating, it is particularly preferably a metal fine particle of 5 to 50 nm.

  When the observation image of the metal nanoparticles (A) in the electron microscope has a shape that is symmetrical with respect to the short axis and the long axis, such as a lens shape, a rod shape, or a wire shape, the short diameter is preferably 1 to 200 nm. Is 2 to 100 nm, more preferably 5 to 50 nm. The particle size distribution of the metal nanoparticles (A) may be monodispersed, or may be a mixture of particles having a particle size in the above preferred particle size range.

  There is no restriction | limiting in particular as a manufacturing method of the metal nanoparticle (A) used by this invention, It can manufacture using various methods, For example, vapor phase methods, such as a low-vacuum gas evaporation method, are used. Alternatively, the metal compound may be reduced in a liquid phase to directly prepare a dispersion of metal fine particles. Among the gas phase and liquid phase methods, the liquid phase method can be particularly suitably used because of its stability in the primer composition for plating and the simplicity of the production process.

  The metal nanoparticles (A) used in the present invention maintain the dispersion stability without being aggregated, fused or precipitated in the plating primer composition of the present invention, and are formed by the primer composition. The surface of the metal nanoparticles (A) was protected with an organic compound protective agent (also referred to as an organic protective agent (P) in the present specification) in order to develop a function of being firmly fixed therein. A composite is preferred. As a protective agent for such an organic compound, it is preferable to use a protective agent having a hydroxyl group or an amino group that is reactive with an isocyanate group when the blocking agent is dissociated, such as polyvinyl alcohol, polyallylamine, polyethyleneimine. A compound having a block such as polypropyleneimine can be preferably used. In addition to these structures, it is preferable to introduce a polyethylene glycol part because the dispersion stability of the metal nanoparticles (A) can be improved. Among these, the compound (P1) having a polyethyleneimine block and a polyethylene glycol block is preferable. It can be particularly preferably used.

  The compound (P1) having a polyethyleneimine block and a polyethyleneglycol block can be obtained, for example, by introducing a functional group into the terminal of a commercially available polyethyleneglycol and chemically bonding this to a commercially available polyethyleneimine. A compound in which polyethylene glycol (x2) having a number average molecular weight of 500 to 5,000 is bonded to an amino group in polyethyleneimine (x1) having a number average molecular weight of 500 to 50,000 is particularly preferably used. Can do. The compound (P1) having a polyethyleneimine block and a polyethyleneglycol block that can be used in the present invention only needs to have a specific structure of a polyethyleneimine block and a polyethyleneglycol block, and further has other structures introduced. It may be.

  As a method for producing a dispersion of metal nanoparticles (A) by the liquid phase method, a method of reducing a metal compound in the presence of the organic protective agent (P) in the liquid phase can be suitably used. It can be produced using the methods described in JP 2008-037884 A, JP 2008-037949 A, JP 2008-03818 A, and JP 2010-007124 A. For example, after the compound (P1) having the polyethyleneimine block and the polyethylene glycol block described above is dissolved or dispersed in an aqueous medium, that is, water described later or a mixed solvent of water and a water-soluble organic solvent, After adding a metal compound here and using a complexing agent together as necessary to form a uniform dispersion or simultaneously with the complexing agent, the reduced metal is mixed with nanoparticles ( Metal nanoparticles (A) can be obtained by forming fine particles having a size on the order of nanometers. In this method, the organic protective agent (P1) protects the surface of the metal nanoparticles (A) simultaneously with the formation of the metal nanoparticles (A), and the composite of the metal nanoparticles (A) and the organic protective agent (P1). The body is formed.

  In the production of the primer composition for plating of the present invention, the metal nanoparticles (A) of the present invention are preferably in a form in which the metal nanoparticles (A) are dispersed in a solvent. As the solvent (C-1) for dispersing the metal nanoparticles (A), the metal nanoparticles (A) can be stably dispersed, and the blocked isocyanate (B) described later can be directly dissolved or dispersed, or the blocked isocyanate ( There is no particular limitation as long as the solution or dispersion of B) can be mixed, and various solvents can be used. Any of water, a mixed solvent of water and a water-soluble organic solvent, or an organic solvent not containing water can be used. It may be. At this time, the surface of the metal nanoparticles (A) may be a composite of the metal nanoparticles (A) and the organic protective agent (P) protected by the organic protective agent (P). It is preferable for enhancing the effect of the invention. The said organic protective agent (P) used by this invention may be added at the time of manufacture of a metal nanoparticle (A), and may be added after manufacturing a metal nanoparticle (A).

  As an organic protective agent (P) used by this invention, it is preferable that it is 20 mass% or less with respect to a metal nanoparticle (A) from a dispersion-stable viewpoint, and it is a seed for electroplating, and for electroless plating. From the viewpoint of a catalyst, it is preferably 10% by mass or less.

  An aqueous dispersion of the metal nanoparticles (A) of the present invention or a mixed solvent dispersion of water and a water-soluble organic solvent can be produced by the above-described liquid phase synthesis method. Thus, it is possible to change the solvent composition of the dispersion liquid at the time of production and the dispersion liquid of the nanometal (A) for producing the primer composition for plating by solvent exchange or solvent addition.

  Examples of the water-soluble solvent that can be mixed with water include alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, acetone, -Ketones such as butanone, polyhydric alcohols such as ethylene glycol and glycerin and other esters, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, propylene glycol methyl ether acetate, butyl diethylene glycol acetate Glycol ethers such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethyl Such as amide solvents such as formamide can be exemplified, these solvents singly, or a plurality of the may be used in admixture with water.

  As the organic solvent, a water-soluble solvent that can be mixed with water may be used alone, or a mixture of a plurality of water-soluble solvents may be used without mixing water. In this case, water may be contained a little due to moisture absorption or the like, but since it is not intended to be mixed with water, it is treated as an organic solvent not containing water in the present invention.

<Block isocyanate compound (B)>
The blocked isocyanate (B) used in the present invention has a functional group [b] formed by blocking an isocyanate group with a blocking agent, and a commercially available blocked isocyanate may be used or produced as necessary. May be used.

  The blocked isocyanate (B) can be produced by reacting a part or all of the isocyanate groups of the isocyanate compound (b-1) with a blocking agent.

  As an isocyanate compound (b-1) which can be used for manufacture of the said block isocyanate (B), what has an isocyanate group can be used, for example, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate. Carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate and other polyisocyanate compounds, hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate , Tetramethylxylylenedi Aliphatic polyisocyanate compounds such as cyanate, polyisocyanate compounds having an aliphatic cyclic structure, their biuret, isocyanurate, can be used an adduct and the like.

  Moreover, as said isocyanate compound (b-1), what is obtained by making the said polyisocyanate compound and the compound which has a hydroxyl group or an amino group react can be used.

  As the compound having a hydroxyl group, a compound having a hydrophilic group and a hydroxyl group is preferably used from the viewpoint of adhesion between the primer composition for plating of the present invention and the insulating substrate. Further, when the blocked isocyanate (B) is used in combination with an aqueous medium, good water dispersion stability can be imparted to the blocked isocyanate (B) by using a compound having a hydrophilic group and a hydroxyl group. Therefore, it is preferable.

  Examples of the compound having a hydrophilic group and a hydroxyl group include a polyol having a carboxyl group such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolvaleric acid; Polyols having a sulfonic acid group such as isophthalic acid, sulfoterephthalic acid, 4-sulfophthalic acid, and 5- (4-sulfophenoxy) isophthalic acid can be used.

  Examples of the compound having a nonionic hydrophilic group and a hydroxyl group include polyethylene glycol, polyethylene-polypropylene copolymer, polyethylene glycol monomethyl ether, polyethylene glycol monoethyl ether, polyethylene glycol monopropyl ether, polyethylene glycol monobutyl ether, and the like. Can be used.

  As the compound having an amino group, a compound having a hydrophilic group and an amino group can be used. For example, 2-aminopropionic acid, 2-aminoethylsulfonic acid, 4-aminobenzenesulfonic acid, 2 , 6-diaminohexanoic acid, 2,5-diaminovaleric acid and the like can be used.

  From the viewpoint of improving the adhesion between the primer layer for plating obtained using the primer composition for plating of the present invention and the insulating substrate, the isocyanate compound (b-1) is aromatic to the blocked isocyanate (B). It is preferable to use one having a structure introduced, and it is preferable to use a polyisocyanate compound having an aromatic structure. Of these, 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, isocyanurate of 4,4'-diphenylmethane diisocyanate, and isocyanurate of tolylene diisocyanate are more preferably used.

  Examples of the blocking agent that can be used in the production of the blocked isocyanate (B) include phenol compounds such as phenol and cresol; lactams such as ε-caprolactam, δ-valerolactam, and γ-butyrolactam; formamide oxime, acetoaldoxime, and acetone. In addition to oximes such as oxime, methyl ethyl ketoxime, methyl isobutyl ketoxime, cyclohexanone oxime, 2-hydroxypyridine, butyl cellosolve, propylene glycol monomethyl ether, benzyl alcohol, methanol, ethanol, n-butanol, isobutanol, dimethyl malonate, malonic acid Diethyl, methyl acetoacetate, ethyl acetoacetate, acetylacetone, butyl mercaptan, dodecyl mercaptan, acetanilide, acetic acid acetate Succinimide, maleic imide, imidazole, 2-methylimidazole, urea, thiourea, ethylene urea, diphenylaniline, aniline, carbazole, ethyleneimine, polyethyleneimine, 1H-pyrazole, 3-methylpyrazole, 3,5 -Dimethylpyrazole etc. can be used. Among them, it is preferable to use a blocking agent that can be dissociated by heating to 70 ° C. to 200 ° C., more preferably 110 ° C. to 180 ° C. to generate an isocyanate group, and the phenol compound, lactam, or oxime is used. More preferably it is used.

  The blocked isocyanate (B) may be produced by mixing and reacting the isocyanate compound (b-1) produced in advance with the blocking agent, and for producing the isocyanate compound (b-1). It can manufacture by mixing the said blocking agent with the raw material to be used, and making it react.

  More specifically, the blocked isocyanate (B) used in the present invention has an isocyanate group at the end by reacting the polyisocyanate compound (b-1-1) with a compound having a hydroxyl group or an amino group. The isocyanate compound (b-1) can be produced, and then the isocyanate compound (b-1) and the blocking agent can be mixed and reacted.

  For the purpose of imparting water dispersion stability and storage stability to the blocked isocyanate (B), a method using a blocked isocyanate having a hydrophilic group as the blocked isocyanate (B), a method using a surfactant in combination, etc. Is mentioned.

  As said hydrophilic group, an anionic group, a cationic group, and a nonionic group can be used, for example, It is more preferable to use an anionic group.

  As the anionic group, for example, a carboxyl group, a carboxylate group, a sulfonic acid group, a sulfonate group, and the like can be used. Among them, a part or all of the carboxyl group or sulfonic acid group is neutralized by a basic compound. It is preferable to use the formed carboxylate group or sulfonate group in order to impart excellent water dispersion stability.

  Examples of basic compounds that can be used to neutralize the anionic group include organic amines such as ammonia, triethylamine, pyridine, morpholine, alkanolamines such as monoethanolamine, metal bases including sodium, potassium, lithium, and calcium. Compounds. For the purpose of producing a conductive material by plating, it is preferable to use the organic amine or alkanolamine because the metal base compound may inhibit the conductivity.

  Moreover, as said cationic group, a tertiary amino group can be used, for example. Examples of the acid that can be used for neutralizing part or all of the tertiary amino group include organic acids such as acetic acid, propionic acid, lactic acid, and maleic acid, and organic acids such as sulfonic acid and methanesulfonic acid. You may use inorganic acids, such as a sulfonic acid, hydrochloric acid, a sulfuric acid, orthophosphoric acid, orthophosphorous acid, individually or in combination of 2 or more types. For the purpose of producing a conductive material by plating treatment, it may be preferable to use acetic acid, propionic acid, lactic acid, maleic acid, etc., because chlorine and sulfur may hinder the conductivity.

  Examples of the nonionic group include polyoxyalkylene groups such as a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a poly (oxyethylene-oxypropylene) group, and a polyoxyethylene-polyoxypropylene group. Can be used. Among these, it is preferable to use a polyoxyalkylene group having an oxyethylene unit in order to further improve the hydrophilicity.

  In producing the blocked isocyanate (A), the hydrophilic group is a compound having a hydrophilic group such as 2,2-dimethylolpropionic acid and a hydroxyl group, and the isocyanate compound (b1-1). It can introduce | transduce into blocked isocyanate (B) by making it react.

  Examples of surfactants that can be used for the purpose of imparting water dispersion stability to the blocked isocyanate (B) include, for example, anionic surfactants, nonionic surfactants, and cationic surfactants. And zwitterionic surfactants.

  Examples of the anionic surfactant include sulfates of higher alcohols and salts thereof, alkylbenzene sulfonates, polyoxyethylene alkylphenyl sulfonates, polyoxyethylene alkyl diphenyl ether sulfonates, and polyoxyethylene alkyl ethers. Examples include non-ionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylene alkyl phenyl ether. Ethylene diphenyl ether, polyoxyethylene-polyoxypropylene block copolymer, acetylenic diol surfactant and the like can be used.

  Moreover, as said cationic surfactant, alkyl ammonium salt etc. can be used, for example.

  In addition, as the zwitterionic surfactant, for example, alkyl (amido) betaine, alkyldimethylamine oxide and the like can be used.

  As the surfactant, in addition to those described above, fluorine-based surfactants, silicone-based surfactants, and the like can be used.

  In producing the primer composition for plating of the present invention, the blocked isocyanate (B) used in the present invention is preferably mixed with the metal nanoparticle (A) dispersion in the form of a solution or dispersion.

  As the solvent (C-2) for dissolving or dispersing the blocked isocyanate (B) used in the present invention, water, a mixture of water and a water-soluble organic solvent, or an organic solvent not containing water can be used. From the solvent group illustrated as a solvent which disperse | distributes a nanoparticle (A), it can select and use. As the solvent to be selected, the same solvent as the solvent in which the metal nanoparticles (A) are dispersed may be selected, or another solvent may be selected.

<Solvent (C)>
The solvent (C) constituting the primer composition for plating of the present invention is not particularly limited as long as it forms a stable dispersion in the state containing the metal nanoparticles (A) and the blocked isocyanate (B). However, any of water, a mixed solvent of water and a water-soluble organic solvent, and an organic solvent not containing water may be used.

  Examples of the water-soluble solvent that can be mixed with water include alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, acetone, -Ketones such as butanone, polyhydric alcohols such as ethylene glycol and glycerin and other esters, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, propylene glycol methyl ether acetate, butyl diethylene glycol acetate Glycol ethers such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethyl Can be mentioned amide solvents such as formamide, these solvents singly, or a plurality of the may be used in admixture with water.

  As the organic solvent, a water-soluble solvent that can be mixed with water may be used alone, or a mixture of a plurality of water-soluble solvents may be used without mixing water. In this case, water may be contained a little due to moisture absorption or the like, but since it is not intended to be mixed with water, it is treated as an organic solvent not containing water in the present invention.

  As said solvent (C) which comprises the primer composition for metal plating of this invention, manufacture of the primer composition for metal plating of this invention is the solution or dispersion | distribution of the dispersion liquid of a metal nanoparticle (A), and blocked isocyanate (B). When the liquid is mixed, it is a mixed solvent of the solvent (C-1) in which the metal nanoparticles are dispersed and the solvent (C-2) in which the blocked isocyanate is dissolved or dispersed. One or a plurality of solvents selected from the solvent group may be mixed.

<Compound (D) having reactivity with isocyanate>
In the primer composition for plating of this invention, the primer composition for plating containing a metal nanoparticle (A), blocked isocyanate (B), and a solvent (C) from a viewpoint of improving the intensity | strength of the primer layer for plating formed. The product can further contain a compound (D) having reactivity with an isocyanate group. The compound (D) can be stably dissolved or dispersed together with the metal nanoparticles (A) and the blocked isocyanate (B) in the solvent (C), and an isocyanate group formed by dissociation of the blocking agent. A compound having a functional group capable of reacting can be used.

  Examples of the functional group capable of reacting with the isocyanate group generated by dissociation of the blocking agent include a carboxyl group, a hydroxyl group, and an amino group. A compound having two or more of these functional groups in the structure is preferable. Can be used. In the primer composition for plating of the present invention, when the surface of the metal nanoparticles (A) is protected with a compound having a block such as polyallylamine, polyethyleneimine, and polypropyleneimine, From the viewpoint of compatibility, a compound having an amino group is more preferable.

  Examples of such compounds include acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, ethylene glycol, diethylene recall, triethylene glycol, propylene glycol, 1,3-propanediol, and 1,3-butanediol. 1,4-butanediol, hexamethylene glycol, saccharose, methylene glycol, glycerin, sorbitol and other relatively low molecular weight polyols, 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropion Acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, lysine, arginine, hydrazine, ethylenediamine, propylenediamine, hexamethyle Diamine, 1,2-diaminoethane, 1,2-diaminopropane, 1,3-diaminopentane, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 4,4'-methylenedianiline, polyethylene One kind or a plurality of kinds selected from polyalkyleneimines such as imine and polypropyleneimine, polyallylamine and the like can be selected and used. In the primer composition for plating according to the present invention, when the surface of the metal nanoparticles (A) is protected with a compound having a block such as polyethyleneimine or polypropyleneimine, the compatibility in the primer composition. In view of the above, polyalkylenimine is more preferable.

<Primer composition for plating>
One suitable form of the primer composition for plating of the present invention comprises the metal nanoparticles (A), the blocked isocyanate (B), and the solvent (C). Moreover, the suitable one form of the primer composition for plating of this invention has the reactivity with respect to an isocyanate group further in the said metal nanoparticle (A), the said block isocyanate (B), and the said solvent (C). The compound (D) is contained.

  In the primer composition for plating of the present invention, a component for forming a primer layer (that is, the metal nanoparticles (A) and the blocked isocyanate (B), and further a compound (D) having reactivity with an isocyanate group) The concentration of the added component) with respect to the total amount of the primer composition may be appropriately adjusted in accordance with various printing, coating methods and surface conditions and shapes of the insulating base material described later, and those of 1% by mass to 70% by mass It is preferable to use 1% by mass to 50% by mass from the viewpoint of coating properties on an insulating substrate. When a thin primer layer for plating of 500 nm or less is formed by various printing / coating methods described later, those having a mass of 1% by mass to 20% by mass can be more suitably used.

  In the primer composition for plating of the present invention, the mass of the metal nanoparticles (A) in the composition, the organic protective agent (P) of the metal nanoparticles (A), the blocked isocyanate (B), and the isocyanate group The ratio of the mass of the compound (D) having reactivity with respect to the compound, that is, (the compound having reactivity to the organic protective agent (P) + block isocyanate (B) + isocyanate group of the metal nanoparticles (A)) (D)) / Metal nanoparticles (A) are preferably from 0.01 to 0.5, more preferably from 0.05 to 0.4. If this ratio is too low, the strength of the plating primer layer itself is lowered, and the film collapses with respect to the peeling behavior of the formed plating film, and sufficient adhesion strength cannot be maintained. On the other hand, when the ratio becomes too high, the metal nanoparticles (A) in the plating primer layer are completely buried in the primer layer, and are used as a conductive or electroless plating catalyst necessary for the electroplating process. The function of can not be expressed.

  In the primer composition for plating of the present invention, the addition amount of the compound (D) having reactivity with the isocyanate group is equivalent to the isocyanate functional group equivalent in the state where the blocking agent is eliminated in the blocked isocyanate (B). The reactive functional group equivalent to the isocyanate in the compound (D) having reactivity with respect to the isocyanate, ie (the reactive functional group equivalent of (D)) / (the NCO equivalent of (B)) is 10/1. It is preferable to adjust so as to be ˜1 / 5. As for the functional group equivalent and the NCO equivalent, for commercially available materials, values described in catalogs and data sheets may be used, or may be measured using known and commonly used methods. A product obtained by dividing the molecular weight by the number of functional groups may be used for convenience.

  In the primer composition for plating of the present invention, various surface tension adjusting agents and leveling agents can be added and used as needed mainly for the purpose of improving coating film-forming properties. The addition amount of these surface tension adjusting agent and leveling agent is preferably 1.0% by mass or less, particularly preferably 0.5% by mass or less of the active ingredient, with respect to the primer composition.

<Formation of a primer layer for plating using the primer composition for plating of the present invention>
In the present invention,
(1) On an insulating substrate, at least one metal nanoparticle (A) selected from the group consisting of silver nanoparticles, copper nanoparticles, silver core-copper shell nanoparticles, and silver-copper anisotropic composite particles (A) And a step of coating a primer composition for plating containing the block isocyanate (B) and the solvent (C),
(2) A plating primer layer can be formed through a step of heating the insulating substrate coated with the plating primer composition.

  In the step (1), the method for coating the plating primer composition of the present invention on an insulating substrate is not particularly limited, and various known and commonly used printing and coating techniques are insulated. The shape may be selected as appropriate depending on the shape, size, degree of flexibility, etc., specifically, gravure method, offset method, letterpress method, letterpress inversion method, screen method, microcontact method, reverse method, air doctor Coater method, blade coater method, air knife coater method, squeeze coater method, impregnation coater method, transfer roll coater method, kiss coater method, cast coater method, spray coater method, ink jet method, die method, spin coater method, bar coater method, dip Examples thereof include a coating method.

  In the step (1), the plating primer composition of the present invention may be applied to the entire surface of the insulating substrate, or may be partially applied / printed, and only a part thereof. It is also possible to coat and print on. When coating / printing is performed in a pattern, a metal plating film corresponding to the coating / printing pattern can be formed in a plating process described later.

  In the heating step described in the step (2), various known and commonly used heating methods can be used. An electric furnace, a muffle furnace, a vacuum furnace, an atmosphere furnace, a light irradiation heating device, an infrared heating device, a far infrared ray. One or a plurality of heating devices such as a heating device, a microwave heating device, and an electron beam heating device can be used. In addition, the heat treatment can be performed in air, vacuum, nitrogen atmosphere, argon atmosphere, or hydrogen atmosphere below the lower explosion limit as required. Moreover, when the base material to which the primer composition for plating is applied is a sheet film, sheet, or plate, it may be carried out in the apparatus of the heat treatment apparatus. , Light heating, (far) infrared heating, and microwave heating can be performed by continuously moving the sheet into the space.

  In the present invention, the heat treatment described in the step (2) may be performed simultaneously with drying after applying the primer composition for plating (B) on the insulating base material (A), or may be performed by drying. And heat treatment may be performed separately.

  In the present invention, the heat treatment in the step (2) may be performed at a temperature higher than the temperature at which the blocking agent of the blocked isocyanate (B) contained in the primer composition for plating dissociates, and the heat resistance of the insulating base material used. What is necessary is just to set suitably according to temperature and the block isocyanate (B) contained in this composition. For example, if the insulating substrate (A) is a polyimide resin, it is 400 ° C. or less, preferably 300 ° C. or less, polyethylene terephthalate is 150 ° C. or less, polyethylene naphthalate is 200 ° C. or less, liquid crystal polymer is 380 ° C. or less, paper phenol, Heat treatment is preferably performed at 130 ° C. or less for paper epoxy, 150 ° C. or less for glass epoxy, and 100 ° C. or less for ABS resin. In the plating primer composition of the present invention, it is preferable to use a block agent having a dissociation temperature in the range of 70 ° C. to 200 ° C., and the heat treatment temperature is preferably higher than the dissociation temperature. What is necessary is just to select at the temperature of 70 to 400 degreeC according to the kind of block isocyanate. The heat treatment may be performed in a constant temperature state, or the temperature may be changed with time. In the case of changing with time, it may be changed from the vicinity of the dissociation temperature of the blocking agent to a higher temperature, or may be changed from the dissociation temperature to the lower temperature side. The heat treatment time may be appropriately selected depending on the heating device to be used, the type of the insulating base material, and the like. However, from the viewpoint of productivity, it is preferable to perform the heat treatment time within one hour.

  The plating primer composition of the present invention can form a plating primer layer by heating in the step (2), but the blocking agent is dissociated from the blocked isocyanate (B) by the heat treatment, and the isocyanate The group regenerates and self-crosslinks. Further, the regenerated isocyanate group can react with the organic protective agent (P) of the metal nanoparticles (A), and further has a reactivity with the isocyanate group in the primer composition for plating. When the compound (D) is contained, a cross-linked structure is formed in the primer layer by reacting the isocyanate group and the reactive compound (D). Thus, by forming a crosslinked structure in the primer layer for plating, the strength of the primer layer is improved, and the metal nanoparticles (A) are firmly fixed in the primer layer.

  The primer layer for plating of the present invention is a form in which the metal nanoparticles (A) are immobilized in the resin layer, and the self-crosslinked resin of the blocked isocyanate (B) or the blocking agent is detached. In this form, the metal nanoparticles (A) are immobilized by a resin formed by the reaction between the isocyanate to be produced and the compound (D) having reactivity with the isocyanate group. One form thereof is a form in which a part of the surface of the metal nanoparticles (A) in the outermost layer is exposed on the surface of the resin layer (FIGS. 1 to 3). The outermost surface of the primer layer is the resin layer surface, and the metal nanoparticles (A) are present in the resin layer (FIGS. 4 to 6).

  The primer composition for plating of the present invention can form a primer layer for plating by heating in the step (2), but is occupied because the blocking agent is detached from the blocked isocyanate (B) by the heat treatment. In the primer layer due to volume reduction, self-crosslinking by the regenerated isocyanate group, reaction of the isocyanate group with the organic protective agent of the metal nanoparticles (A), and reaction of the isocyanate group and the reactive compound (D) As a result of the formation of the crosslinked structure, the resin part constituting the primer layer contracts, and as a result of the shrinkage, the metal nanoparticles (A) are closely packed in the primer layer. As a result, the conductivity of the primer layer is improved. A primer layer effective for the electroplating process can be formed. By including the metal nanoparticles (A) in the cross-linked structure, the interface between the plating primer layer and the insulating substrate and the primer layer itself are maintained without collapsing. When a large number of microcracks are formed on the outermost surface of a certain resin layer, and the heat treatment is higher than the volatilization temperature or thermal decomposition temperature of the desorbed blocking agent, the desorbed block is further removed. The formation of microcracks on the outermost surface of the primer layer is promoted by the evaporation of the agent or the evaporation of the pyrolyzate (FIGS. 1 to 6).

  In the primer layer for plating of the present invention, the plating solution penetrates into the micro cracks generated by the heat treatment in the subsequent plating process, and forms a good plating film by contacting the metal nanoparticles (A). be able to. In this case, when the plating process is an electroplating process, the metal nanoparticles (A) function as a conductive path. When the plating process is an electroless plating process, the metal nanoparticles (A) are electroless plated. Functions as a catalyst. For this reason, in both the electroplating process and the electroless plating process, the metal nanoparticles (A) contacted by the plating solution through the microcracks generated on the surface of the primer layer become the growth starting point of the plated metal film. In the plating primer layer of the present invention, in addition to the metal nanoparticles (A) being firmly fixed to the primer layer, the microcracks generated on the surface of the primer layer are anchor points of the plating metal film. By functioning as, it is possible to impart high adhesion to the plated metal film.

  When the primer layer for plating of the present invention is used as a primer layer for electroplating, it is necessary that at least one layer composed of metal nanoparticles (A) exists in the cross-sectional direction of the primer layer. It is preferable from the viewpoint of providing conductivity necessary for electroplating that a layer to 10 layers are present. From the viewpoint of conductivity, it is preferable to have a large number of layers. However, since the cost is high, it is more preferable that the number of layers is about 2 to 6. It is necessary to prioritize conductivity or prioritize cost. Select according to your needs. In this case, the layer composed of the metal nanoparticles (A) does not need to be close-packed in the planar direction, and there are contact points between the metal nanoparticles (A), and the overall conductivity in the surface is low. It only needs to be confirmed.

  When the primer layer for plating of the present invention is used as a primer layer for electroless plating, the primer layer for electroplating can also be suitably used as a primer layer for electroless plating. As a primer layer for electroless plating, it is not always necessary that one or more layers of metal nanoparticles (A) exist in the cross-sectional direction, and discrete single metal nanoparticles are immobilized in the resin layer. Although the structure can be used, from the viewpoint of ensuring stable plating property and adhesion of the plated metal film, the layer made of the metal nanoparticles (A) has about 1 to 6 layers in the cross-sectional direction of the layer. It is preferable to exist in a laminated state. When used as a primer layer for electroless plating, the layer composed of the metal nanoparticles (A) does not necessarily have to have a contact point between the metal nanoparticles (A) in the entire plane. The layer which consists of the metal nanoparticle (A) laminated | stacked to a certain extent may exist separately in a primer layer, respectively (FIGS. 5 and 6).

  What is necessary is just to adjust suitably as the thickness of the primer layer for plating of this invention with the particle size of the metal nanoparticle (A) contained in the primer composition for plating. As described above, in the present primer layer, it is desirable that the metal nanoparticles (A) are laminated in two to ten layers, so that the thickness of the primer layer is as follows in the primer composition used for plating. What is necessary is just to set so that it may become a film thickness which multiplied the particle size of the metal nanoparticle (A) contained in the number of layers. Actually, since the particles are not simply stacked and filled, a film thickness of about ± 20% of the calculated film thickness is suitable. For example, when a metal nanoparticle (A) having an average particle diameter of 20 nm is used to form a layer made of 10 metal nanoparticles (A), a primer layer having a thickness of about 160 to 240 nm is used. Is good. In consideration of cost and the like, about 6 layers are more preferable, and a primer layer having a thickness of about 100 nm to 150 nm can be used.

  What is necessary is just to perform the thickness of a primer layer by adjusting the density | concentration of the primer layer formation component contained in the said primer composition for plating.

<Plating treatment>
As a plating treatment for forming a metal layer on an insulating substrate using the primer composition for plating treatment of the present invention, either an electroless plating treatment or an electroplating treatment may be used. An electroplating process may be performed later. Electroless plating is advantageous when the shape of the object to be plated and the pattern to be plated are complex and it is difficult to supply power. However, since the metal layer formation speed is slow, power can be supplied and a thick metal layer is formed. If desired, electroplating is more advantageous.

<Electroless plating treatment>
As the electroless plating treatment method for the substrate to be plated of the present invention (the insulating substrate on which the primer layer for plating of the present invention is formed), a publicly known and commonly used method may be used. In the plating primer layer, metal nanoparticles (A) that function as a catalyst for electroless plating are present in the primer layer, so electroless plating is performed without applying a catalyst and activating step in the conventional plating process. This has the advantage of shortening the process. Although the to-be-plated base material of this invention can perform the process with an electroless-plating liquid after a degreasing process, you may perform washing | cleaning operation by an acid or an alkali after degreasing.

  In the present invention, the type of the plating metal is not particularly limited. However, when the conductivity of the metal layer is necessary, it is preferable to perform electroless copper plating from the viewpoint of conductivity and industrial utility. In this electroless copper plating, a bath may be used with the composition of the electroless copper plating solution described in the literature, or a commercially available electroless plating reagent may be used. Commercially available electroless plating reagents are sold for various uses such as thickening, thinning, selective deposition, etc., and may be appropriately selected according to the purpose. For example, OPC Copper Series manufactured by Okuno Pharmaceutical Co., Ltd. An OIC copper or the like can be used particularly preferably.

<Electrolytic plating>
There is no restriction | limiting in particular when performing an electroplating process with respect to the to-be-plated base material of this invention, It can carry out easily by a well-known and usual method. As the plating solution, a solution having a composition described in various documents may be prepared and used, or a commercially available electroplating solution may be purchased and used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited to these Examples. Unless otherwise specified, “%” represents “mass%”.

<Description of equipment used in the present invention>
The equipment used in the present invention is as follows.
For analysis of the synthesized organic protective agent, AL300, 300 Hz ¹ H-NMR manufactured by JEOL Ltd. was used, and the amount of the organic protective agent combined with metal nanoparticles was estimated by TG / SII Nano Technology Co., Ltd. It calculated from the result of the thermogravimetric analysis using DTA6300. The plasmon absorption spectrum of the metal nanoparticles was a UV-3500 UV-visible absorptiometer manufactured by Hitachi, Ltd.

  A JEM-2200FS transmission electron microscope manufactured by JEOL Ltd. was used for morphological observation and particle size measurement of the metal nanoparticles.

  SEM observation of the surface and cross section of the primer layer for plating was performed using a JSM-7800F Schottky field emission scanning electron microscope manufactured by JEOL Ltd.

  A low resistivity meter Loresta EP (4-terminal method) manufactured by Mitsubishi Chemical Corporation was used for measuring the surface resistance values of the primer layer and the metal plating layer.

  To measure the peel strength of the plating film, attach a special attachment to the bond tester SS-30WD manufactured by Saishin Shoji Co., Ltd., peel the plating film from the substrate into a 1 cm strip, and determine the tensile strength in the 90 ° C direction. It was measured.

Synthesis Example 1 Synthesis of Compound (P1) Having Polyethyleneimine (PEI) Block and Polyethylene Glycol (PEG) Block 1-1 [Synthesis of Tosylated Polyethylene Glycol]
A solution of 150 ml of chloroform mixed with 150 g [30 mmol] of one-end methoxylated polyethylene glycol (hereinafter referred to as “PEGM” [number average molecular weight (Mn) 5000] (manufactured by Aldrich)) and 24 g (300 mmol) of pyridine, and 29 g (150 mmol) of tosyl chloride ) And 30 ml of chloroform were mixed uniformly.
While stirring a mixed solution of PEGM and pyridine at 20 ° C., a toluene solution of tosyl chloride was added dropwise thereto. After completion of the dropping, the reaction was carried out at 40 ° C. for 2 hours. After completion of the reaction, the reaction mixture was diluted with 150 ml of chloroform, washed with 250 ml (340 mmol) of 5% aqueous HCl, and then washed with saturated brine and water. The obtained chloroform solution was dried over sodium sulfate, and then the solvent was distilled off with an evaporator and further dried. The yield was 100%. Each peak was assigned by ¹ H-NMR spectrum (2.4 ppm: methyl group in tosyl group, 3.3 ppm: methyl group at PEGM terminal, 3.6 ppm: EG chain of PEG, 7.3-7.8 ppm) : Benzene ring in tosyl group) and tosylated polyethylene glycol.

1-2 [Synthesis of Compound (P1) Having (Polyethyleneimine (PEI) Block and Polyethylene Glycol (PEG) Block)]
Tosylated polyethylene glycol 23.2 g (4.5 mmol) obtained in 1-1 above and 15.0 g (1.5 mmol) of polyethyleneimine (hereinafter referred to as PEI, Nippon Shokubai Co., Ltd., Epomin SP200) were added to dimethylacetamide (hereinafter referred to as , DMA) After dissolving in 180 ml, 0.12 g of potassium carbonate was added, and the mixture was reacted at 100 ° C. for 6 hours in a nitrogen atmosphere. After completion of the reaction, the solid residue was removed, and a mixed solvent of 150 ml of ethyl acetate and 450 ml of hexane was added to obtain a precipitate. The precipitate was dissolved in 100 ml of chloroform and reprecipitated again by adding a mixed solvent of 150 ml of ethyl acetate and 450 ml of hexane. This was filtered and dried under reduced pressure. Each peak was assigned by ¹ H-NMR spectrum (2.3 to 2.7 ppm: ethylene of PEI, 3.3 ppm: methyl group at the PEG end, 3.6 ppm: EG chain of PEG), and the PEI-PEG structure was determined. It was confirmed that the compound was (P1). The yield was 99%.

<Manufacture of metal nanoparticles (A)>
Synthesis example 2
10.0 g of silver oxide was added to 138.8 g of an aqueous solution containing 0.592 g of the compound (P1) obtained in Synthesis Example 1, and the mixture was stirred at 25 ° C. for 30 minutes. Subsequently, when 46.0 g of dimethylethanolamine was gradually added with stirring, the reaction solution turned black-red and slightly exothermic, but was left as it was and stirred at 25 ° C. for 30 minutes. Thereafter, 15.2 g of a 10% ascorbic acid aqueous solution was gradually added with stirring. While maintaining the temperature, stirring was continued for another 20 hours to obtain a black-red dispersion.

  A mixed solvent of 200 ml of isopropyl alcohol and 200 ml of hexane was added to the dispersion obtained after completion of the reaction and stirred for 2 minutes, followed by centrifugal concentration at 3000 rpm for 5 minutes. After removing the supernatant, a mixed solvent of 50 ml of isopropyl alcohol and 50 ml of hexane was added to the precipitate and stirred for 2 minutes, followed by centrifugal concentration at 3000 rpm for 5 minutes. After removing the supernatant, 20 g of water was further added to the precipitate, followed by stirring for 2 minutes, and the organic solvent was removed under reduced pressure to obtain an aqueous dispersion of silver nanoparticles.

  The obtained dispersion was sampled, and a peak of a plasmon absorption spectrum was observed at 400 nm by measuring a visible absorption spectrum of a 10-fold diluted solution, thereby confirming the formation of silver nanoparticles. Moreover, spherical silver nanoparticles (average particle diameter: 17.5 nm) were confirmed by TEM observation. As a result of measuring the silver content in the solid using TG-DTA, it was 97.2%. From this, the silver nanoparticles obtained by this synthesis method are a complex with an organic protective agent (P1) composed of PEI-PEG, and the content of the organic protective agent (P1) composed of PEI-PEG in the complex is It can be estimated at 2.8%.

<Production of blocked isocyanate (B)>
Synthesis example 3
In a nitrogen-substituted reaction vessel equipped with a thermometer, a nitrogen gas introduction tube, and a stirrer, 6.3 parts by mass of 2,2-dimethylolpropionic acid and a nurate 71.1 of 4,4′-diphenylmethane diisocyanate After preparing an isocyanate compound by reacting with parts by mass in 2-butanone, 17.8 parts by mass of phenol is supplied as a blocking agent to the reaction vessel and reacted to produce a blocked polyisocyanate (B-1). A solvent solution was prepared. Then, 2-butanone was supplied and the solid content was adjusted to obtain a methyl ethyl ketone solution (solid content 10%) of the block polyisocyanate (B-1).

Example 1
(Preparation of primer composition for plating)
The silver nanoparticle aqueous dispersion obtained in Synthesis Example 2 is left to stand in a freezer at −40 ° C. for one day to freeze, and this is treated with a freeze dryer (FDU-2200, manufactured by Tokyo Rika Kikai Co., Ltd.) for 24 hours. As a result, an organic protective agent composite powder composed of silver nanoparticles composed of flaky lumps having a grayish green metallic luster and PEI-PEG was obtained. Ethanol was added to the powder and stirred to obtain a 70% ethanol dispersion of a complex of silver nanoparticles and an organic protective agent composed of PEI-PEG.

Vernock D-500 (DIC aromatic group isocyanate) 0.039 g, polyethyleneimine (PEI, Nippon Shokubai Co., sp-200) 1% ethanol solution 0.852 g was added and stirred, dissolved sufficiently After confirming that it was added to 0.304 g of an ethanol dispersion of a complex of the silver nanoparticles obtained in the above step and an organic protective agent composed of PEI-PEG, the mixture was stirred. Further, 3.4 g of ethanol was added, 0.4 g of 1% ethanol solution of KF-351A (manufactured by Shin-Etsu Silicone) was added, and the active ingredient concentration was 5.29% (an organic protective agent composed of silver nanoparticles and PEI-PEG) (4.14% of the composite) was prepared as a primer composition for plating.
(Metal nanoparticle (A) organic protective agent (P) + block isocyanate (B) + compound having reactivity with isocyanate group (D)) / metal nanoparticle (A) in the primer composition for plating Was 0.20 and the amine / NCO ratio was 2.

(Preparation of primer layer for plating on insulating substrate)
The plating primer composition thus obtained was subjected to the condition of speed scale 10 of K-control coater (K101, manufactured by RK Print Coat Instruments) using No. 0 K101 bar (wet film thickness 4 μm). Then, it was applied (bar coat) on a polyimide film (Upilex SGA, 50 μm thickness, manufactured by Ube Industries) as an insulating substrate. The film was dried at room temperature and then baked at 210 ° C. for 5 minutes to form a plating primer layer on the polyimide film. When the resistance of the primer layer for plating was measured, measurement was impossible due to overrange, and it was confirmed that the primer layer was a non-conductive film. When the surface of the prepared primer layer was observed with a scanning electron microscope, it was confirmed that the silver nanoparticles were fixed in the resin and a part of the surface of the silver nanoparticles was exposed on the resin surface (Fig. 7). Further magnification observation confirmed a large number of holes around the silver nanoparticles in the resin layer on which the silver nanoparticles were fixed (FIG. 8).

(Electroless copper plating process)
Electroless copper plating was performed using the polyimide film having a plating primer layer on the surface as described above. The process of electroless copper plating was performed through the steps of degreasing, washing with water, pickling, washing with water, electroless plating, and washing with water. The washing was performed with running water for 2 minutes.
1. Degreasing: Using a degreasing agent (ICP cleaner SC, manufactured by Okuno Pharmaceutical Co., Ltd.), it was immersed in a treatment liquid at 40 ° C. for 5 minutes.
2. Pickling: It was immersed in an aqueous sulfuric acid solution (6%) at 25 ° C. for 2 minutes.
3. Electroless plating: It was immersed in an electroless copper plating solution (OPC copper ARG, manufactured by Okuno Pharmaceutical Co., Ltd.) at 45 ° C. for 30 minutes.

  In the test piece taken out from the electroless copper plating solution, the entire surface of the silver particle coated side became light red, and it was confirmed that the electroless plating of copper proceeded well. The test piece was baked at 100 ° C. for 60 minutes after washing with water and air drying. The surface resistance value of the copper film formed by electroless plating is 0.04Ω / □, and a conductive material having a copper conductive layer on a 38 μm-thick polyimide film that is an insulating substrate is prepared. I was able to. As a result of the tape peeling test using the cellophane tape (manufactured by Nichiban), the copper conductive layer thus formed was not peeled off and had good adhesion.

(Electroplating process)
As described above, electro (copper sulfate) plating was performed using a film-like material in which a copper layer was formed on a polyimide film by electroless copper plating. Copper sulfate plating was performed through the steps of pickling, copper sulfate plating, water washing, rust prevention treatment, and water washing based on a conventional method.
1. Pickling: It was immersed in a sulfuric acid aqueous solution (9%) at 25 ° C. for 1 minute.
2. Copper sulfate plating: A copper sulfate plating solution to which Top Lucina SF-M (Okuno Pharmaceutical Co., Ltd.) was added was used and immersed for 43 minutes at 23 ° C. and 1.66 A / dm ² .
3. Rust prevention treatment: A rust inhibitor (Top Rinse CU-5, manufactured by Okuno Pharmaceutical Co., Ltd.) was used and immersed for 1 minute at 25 ° C.

  The electroplated sample was washed with water, wiped off moisture, dried with hot air, and baked at 120 ° C. for 60 minutes. The average thickness of the copper layer formed on the polyimide film after electroplating is 16 μm, and the insulating substrate-metal composite having a 16 μm-thick copper layer on the 50 μm-thick polyimide film as the insulating substrate. I was able to form. The peel strength of copper formed on the polyimide film shows good adhesion of more than 0.5 kgf / cm, and excellent heat resistance stability of 0.75 kgf / cm even after holding at 150 ° C. for 50 hours High peel strength.

Example 2
Bernock D-500, an ethanol dispersion of a complex of polyethyleneimine 1% ethanol solution, silver nanoparticles, and an organic protective agent composed of a compound (P1) having a polyethyleneimine (PEI) block and a polyethyleneglycol (PEG) block, Ethanol, KF-351 A) 1% ethanol solution was mixed in the same manner as in Example 1 except that the amount was changed to 0.092 g, 1.996 g, 0.356 g, 2.984 g, and 0.5 g, respectively. Then, a primer composition for plating having an active ingredient concentration of 6.18% (a complex of silver nanoparticles and an organic protective agent composed of PEI-PEG 4.09%) was prepared.

  (Metal nanoparticle (A) organic protective agent (P) + block isocyanate (B) + compound having reactivity with isocyanate group (D)) / metal nanoparticle (A) in the primer composition for plating Was 0.33 and the amine / NCO ratio was 2.

  Insulating group having a 16 μm thick copper layer on a 50 μm thick polyimide film, which is an insulating substrate, by forming a primer layer for plating in the same manner as in Example 1, performing electroless copper plating and electrolytic copper plating. A material-metal composite was formed. When the peel strength test of the copper layer on the insulating substrate was performed, the initial peel strength was 0.5 kgf / cm, and the peel strength was excellent at 0.6 kgf / cm even after holding at 150 ° C. for 144 hours. Was holding.

Example 3
The silver nanoparticle aqueous dispersion obtained in Synthesis Example 2 is left to stand in a freezer at −40 ° C. for one day to freeze, and this is treated with a freeze dryer (FDU-2200, manufactured by Tokyo Rika Kikai Co., Ltd.) for 24 hours. Composite powder of silver nanoparticles composed of grey-green metallic luster flakes and an organic protective agent composed of a compound (P1) having a polyethyleneimine (PEI) block and a polyethyleneglycol (PEG) block Got the body. Ethanol was added to this powder and stirred to obtain a 64.5% ethanol dispersion of a complex of silver nanoparticles and an organic protective agent composed of PEI-PEG.

  To 0.26 g of 10% 2-butanone solution of blocked isocyanate obtained in Synthesis Example 3, 3.05 g of 1% dimethylacetamide solution of PEI was added and stirred. In addition, 0.59 g of an ethanol dispersion of a complex of silver nanoparticles and an organic protective agent composed of PEI-PEG was added and stirred. Further, 0.3 g of ethanol was added, 0.8 g of ethanol solution of KF-351A (manufactured by Shin-Etsu Silicone) was added, and the active ingredient concentration was 8.9% (composite of an organic protective agent composed of silver nanoparticles and PEI-PEG). A primer composition for plating with a body of 7.4%) was produced.

  (Metal nanoparticle (A) organic protective agent (P) + block isocyanate (B) + compound having reactivity with isocyanate group (D)) / metal nanoparticle (A) in the primer composition for plating Was 0.15 and the amine / NCO ratio was 1.

  A primer layer for plating was formed on a 50 μm-thick polyimide film in the same manner as in Example 1 except that the firing conditions were changed from 210 ° C. for 5 minutes to 30 minutes. The average thickness of the primer layer estimated from the SEM observation image of the cross section of the film is about 100 nm (FIG. 9), and the surface of the primer layer has silver nanoparticles fixed in the resin and a part of the surface of the silver nanoparticles. Are exposed on the resin surface, and many holes were observed in the resin part around the silver nanoparticles (FIG. 10).

  The substrate to be plated with the primer layer for plating thus obtained was subjected to electroless copper plating and electrolytic copper plating in the same manner as in Example 1, and a polyimide having a thickness of 50 μm, which was an insulating substrate. An insulating substrate-metal composite having a 16 μm thick copper layer could be formed on the film. When the peel strength test of the copper layer on the insulating substrate was conducted, the initial peel strength was 0.55 kgf / cm, and after holding at 150 ° C. for 144 hours, the peel strength was 0.7 kgf / cm and excellent heat resistance and excellent peel strength. Was holding.

Example 4
The primer composition for plating obtained in Example 3 was coated on a 38 μm-thick polyimide film (manufactured by Toray DuPont, Kapton 150EN-C) in the same manner as in Example 1. A substrate to be plated on which a primer composition for plating was formed was prepared. When the surface resistance of the primer layer for plating was measured, the resistance value was 10 ³ Ω / □.
In the same manner as in Example 1, an electroplating treatment was performed to form an insulating substrate-metal composite having a 16 μm thick copper layer on a 38 μm thick polyimide film as an insulating substrate. When the peel strength test of the copper layer on the insulating substrate was performed, a good peel strength of 0.55 kgf / cm was exhibited even after holding at 150 ° C. for 24 hours.

Comparative Example 1
In Example 1, a composite of silver nanoparticles, an organic protective agent comprising a compound (P1) having a polyethyleneimine (PEI) block and a polyethylene glycol (PEG) block, for plating containing Vernock D-500 and PEI Instead of using the primer composition, Example 1 was used except that a 5% ethanol dispersion (adjusted based on Example 1) of a complex of silver nanoparticles and an organic protective agent composed of PEI-PEG was used. In the same manner as above, a composite of an organic protective agent composed of silver nanoparticles and PEI-PEG was applied on a 50 μm-thick polyimide film (Upilex SGA) to prepare a substrate to be plated.

  When this substrate to be plated was plated in the same manner as in Example 1 and subjected to a peel strength test, the peel strength of the plated film was about 0.2 to 0.3 kgf / cm, and the primer layer for plating As a result, the adhesiveness was lower than that of the case where the film was provided.

1: Metal nanoparticles 2: Primer layer for plating 3: Resin layer 4: Insulating substrate 5: Crack

Claims (11)

At least one metal nanoparticle (A) selected from the group consisting of silver nanoparticles, copper nanoparticles, silver core-copper shell nanoparticles and silver-copper anisotropic composite particles, blocked isocyanate (B) and solvent (C ) and a plating primer composition containing the blocked isocyanate (B) is, plating primers, characterized in der Rukoto and blocked by phenol isocyanurate of 4,4'-diphenylmethane diisocyanate Composition . Further, the plating primer composition according to 請 Motomeko 1 you containing a compound having a reactive (D) to isocyanate groups. The compound (D) is a compound having two or more functional groups in the structure, and the functional group is at least one selected from the group consisting of a carboxyl group, a hydroxyl group and an amino group. The primer composition for plating as described in 2 . The primer composition for plating according to claim 3, wherein the functional group in the structure of the compound (D) is a polyalkyleneimine. The primer composition for plating according to any one of claims 1 to 4, wherein the metal nanoparticles (A) are a composite with an organic protective agent (P). The primer composition for plating according to claim 5, wherein the organic protective agent (P) is composed of a compound having any one or more of a polyethyleneimine block, a polypropyleneimine block, and a polyallylamine block in the molecule. The primer composition for plating according to claim 6, wherein the organic protective agent (P) is composed of a compound having a polyethyleneimine block and a polyethylene glycol block. A plated base having a plating primer layer formed of the primer composition for plating according to any one of claims 1 to 7 on an insulating base material that has not been subjected to surface roughening. Wood. A composite of an insulating base material and a metal layer, comprising a plating layer on the plating primer layer of the base material to be plated according to claim 9. (1) Not subjected to surface roughening on an insulating substrate, a step you coating the plating primer composition according to any one of claims 1-7,
(2) having a step of forming a plating primer layer having cracks on the surface thereof by heating the insulating base material coated with the plating primer composition at a temperature of 70 ° C. to 400 ° C. A method for producing a substrate to be plated. A step of further performing a plating treatment on the surface having cracks of the primer layer for plating of the substrate to be plated obtained by the method for producing a substrate to be plated according to any one of claims 1 to 8 was added. wherein the method of producing a composite body of the insulating substrate and the metal layer.

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