JP2016000842A - Manufacturing method of plating - Google Patents

Abstract

A method of manufacturing a plated article by forming a conductive film easily on the surface of an article to be plated having a simple process and having a complicated shape or being easily affected by heat treatment, and Provided is a plated product obtained by the manufacturing method. (I) a step of adsorbing a metal nanoparticle composite containing a metal nanoparticle protective compound (X) and a metal nanoparticle (Y) on the surface of an object to be plated; (II) the step (I) A step of drying the object to be plated on which the metal nanoparticle composite obtained by (3) is adsorbed, and (III) electroplating the object to be plated having a conductive film formed on the surface obtained in the step (II) It has a process, The manufacturing method of plated object characterized by the above-mentioned. [Selection figure] None

Description

  The present invention relates to a method for manufacturing a plated product and a plated product obtained by the manufacturing method.

The plating process is widely used in industry for the purpose of imparting functions such as decoration, environmental resistance, and conductivity to various substrates. In order to plate an insulating base material, first, a method of forming a thin seed layer having conductivity on the surface and further thickening the conductor layer by electroplating can be mentioned. As a method for forming the seed layer, in addition to a general electroless plating method, many direct plating methods that do not use electroless plating have been reported.
For example, Patent Document 1 uses a film obtained by adsorbing a palladium-tin colloid on a substrate and reducing it as a conductor layer. In Patent Document 2, a polymer having a functional group that interacts with a metal ion or a metal salt is provided on a substrate, and the conductor layer is formed by adsorbing the metal ion or the metal salt and then reducing the polymer. In Patent Document 3, a metal compound is impregnated into a surface layer of a base material or a film made of a polyimide precursor resin, and then a metal ion is reduced to form a conductor layer. However, these methods are not economical processes in that there are many steps and expensive palladium is used.
Patent Document 4 forms a conductive film by applying a metal nanoparticle paste on a plastic substrate and heat-sealing it. However, with this method, it is difficult to form a metal film on the surface of a resin molded product having a complicated shape.
As described above, the metal film can be easily formed on the surface of the object to be plated having a complicated shape or the property of being easily adversely affected by the heat treatment in a simple and low-cost process. At present, there is no method for providing high adhesion between the plated product and the metal film.

Japanese Patent Laid-Open No. 11-61425 JP 2007-131875 A Japanese Patent No. 5101623 JP 2010-251703 A

  In view of the above circumstances, the problem to be solved by the present invention is that a metal film (conductive film) can be easily applied to the surface of a plated object having a complicated shape or a surface of a plated object that is easily affected by heat treatment. An object of the present invention is to provide a method for easily producing a plated product having a desired thickness. Moreover, it is providing the plated article obtained by the said manufacturing method.

  The present inventors have focused on metal nanoparticle composites that can be stably dispersed in water and have the property of obtaining conductivity by drying at room temperature or by drying at low temperature, and can apply this to a direct plating process. I came up with the possibility.

  As a result of earnest research to solve the above problems, it is possible to easily form a metal film on the surface of the object to be plated having a complicated shape and the object to be adversely affected by heat treatment, The present inventors have found that a plated product having a desired thickness can be easily obtained and completed the present invention.

That is, the present invention
(1) (I) a step of adsorbing a metal nanoparticle composite containing a metal nanoparticle protective compound (X) and a metal nanoparticle (Y) on the surface of the object to be plated, (II) in the step (I) A step of drying the object to be plated on which the obtained metal nanoparticle composite is adsorbed; (III) a step of electroplating the object to be plated having a conductive film formed on the surface obtained in the step (II); A method for producing a plated product, comprising:
(2) The production method according to (1), wherein the metal nanoparticle protective compound (X) is an anionic compound (X1) or a cationic compound (X2).
(3) The anionic compound (X1) polymerizes at least a (meth) acrylic acid ester having a polyethylene glycol chain having a weight average molecular weight of 100 to 2,000 and a (meth) acrylic acid ester having a phosphate group. The production method according to (1) or (2), wherein the weight average molecular weight is a compound having a weight average molecular weight of 3,000 to 15,000,
(4) The production method according to (1) or (2), wherein the cationic compound (X2) is a phthalocyanine compound, an alkylamine, an alkyldiamine, or a mixture of an alkylamine and an alkyldiamine.
(5) The manufacturing method according to any one of (1) to (3), including a step of cationizing a surface of an object to be plated with a cationizing agent before performing the step (I).
(6) The method according to any one of (1) to (5), wherein the step of adsorbing the metal nanoparticle composite in the step (I) is a step of immersing an object to be plated in the metal nanoparticle composite dispersion. Manufacturing method,
(7) The manufacturing method according to any one of (1) to (6), wherein the metal nanoparticles (Y) are silver nanoparticles, and (8) any one of (1) to (7). The present invention provides a plated product obtained by the described production method.

The plating process of the present invention comprises:
1) Since the metal nanoparticle composite adsorption process for forming a metal film can be performed by immersion, a metal film can be easily formed on the surface of an object to be plated having a complicated shape,
2) Use of a metal nanoparticle composite that has the property of developing conductivity by drying or drying at a low temperature in a short time in addition to drying, so that the object to be plated is susceptible to adverse effects due to heat treatment. A metal film can be easily formed on the surface,
3) In addition, the process is very simple compared to the electroless plating process and the conventional direct plating process, and it is economical because it does not require expensive equipment and special equipment. Play.

<To be plated>
The object to be plated used in the present invention is not particularly limited as long as it is a solid capable of adsorbing the metal nanoparticle composite, but for example, resin molded products, other organic substances, various inorganic substances, organic-inorganic composites. Is mentioned.

  The composition of the resin molded product is not particularly limited. For example, ABS resin, polyimide, polyethylene, polypropylene, polyester, polyvinyl chloride, polystyrene, acrylic resin, urethane resin, epoxy resin, synthetic rubber, various engineering plastics Various natural resins can be suitably used.

  Examples of other organic substances include leather, wood, cloth, paper, and plants.

  Examples of the various inorganic materials include glass, magnets, earthenware, stone materials, metals, and metal oxides.

  Examples of the organic-inorganic composite include composite molded products of the above-described base materials, organic-inorganic composite materials in which an inorganic filler is dispersed in a resin, and biological minerals such as shells.

  Here, the shape of the object to be plated is not particularly limited. For example, the object to be plated may have a curved surface, irregularities, and through holes. That is, it may be a fiber, mesh, or film.

  Among these, those that are easily affected by heat treatment are ABS resin, polyethylene, polyester, polyvinyl chloride, polystyrene, acrylic resin, urethane resin, synthetic rubber, leather, wood, cloth, paper, plant, and the like.

<Cationization treatment of the object to be plated>
When the object to be plated has a negative surface charge and the metal nanoparticle composite has an anionic surface, the surface of the object to be plated is subjected to a cationization treatment agent before performing the step (I). It is preferable to cationize with.

  The cationizing agent is a composition containing a cationic compound, and a commercially available cationic surfactant or a compound having a cationic functional group (amino group or ammonium salt) is dissolved in an aqueous medium. Or it is preferably dispersed.

  Examples of the cationic compound include higher alkyl monoamine salts such as monoalkylamine salts (acetates), alkyldiamine salts such as N-alkylpropylenediaminediolein salts, and quaternary compounds such as alkyltrimethylammonium salts (chlorides). Cationic surfactants commercially available as ammonium salts and the like (the number of carbon atoms in the alkyl group is 6 to 32, preferably about 8 to 24), polyethyleneimine, polyallylamine, polyallylamine salts (hydrochloride, sulfate) Cationic polymers such as polyallylamine salt diallylamine salt copolymer and polyaniline (weight average molecular weight of 1,000 to 100,000, preferably 5000 to 20,000) can be suitably used.

  These cationic compounds are usually preferably adjusted in the range of 0.01 to 50 g / L, more preferably 0.1 to 20 g / L, using water as a medium. When using a compound that is difficult to dissolve uniformly within this range, an organic solvent compatible with water may be used in combination.

  As the pH buffering agent, boric acid, phosphoric acid, ammonium chloride, ammonia, carbonic acid, acetic acid, and the like can be used for the cationizing agent described above. 1-50 g / L is preferable and, as for the usage-amount of a pH buffer, 1-20 g / L is more preferable.

  In the cationization treatment, the simplest method is to perform the treatment by immersing an object to be plated that has been pretreated if necessary in a cationization treatment agent. Although the conditions are not particularly limited, the temperature of the cationization treatment agent is usually about 10 to 80 ° C., preferably 20 to 50 ° C., and the object to be plated is immersed therein. About immersion time, about 1 to 20 minutes are preferable and it is more preferable that it is the range of 2 to 10 minutes. The treatment with such a cationization treatment agent is generally that the surface of the object to be plated is mostly acidic, the cationization treatment for the object to be plated is a subsequent plating process including washing with water, soft etching, etc. This is because the effect is easy to maintain.

<Metal nanoparticle protective compound (X)>
The metal nanoparticle protective compound (X) used in the present invention (also referred to as a colloid protective agent in the present invention) has a metal nanoparticle protective function that suppresses aggregation of the metal nanoparticles and further enables dispersion stabilization. It is. Among these, the anionic compound (X1) and the cationic compound (X2) are preferably used in the present invention.

<Anionic compound (X1)>
The metal nanoparticle composite used in the present invention is a composite of an anionic compound (X1) and metal nanoparticles (Y), which is a composition dispersed in an aqueous medium.

  The anionic compound (X1) used here is a compound having a carboxy group, a phosphoric acid group, a phosphorous acid group, a sulfonic acid group, a sulfinic acid group, and a sulfenic acid group. These functional groups are adsorbed to the metal nanoparticles via the lone pair of heteroatoms, and at the same time, give a negative charge, preventing aggregation of the colloidal particles by charge repulsion between the particles.

  In addition, in order to utilize the colloid protection effect due to the steric repulsion effect at the same time as the repulsive force due to the electric charge, it is considered effective to coexist with a polymer dispersing group that causes dispersion stabilization by spreading with an appropriate volume in the medium. For this reason, polyethylene glycol chains, polyalkylene chains and the like were incorporated in the molecule.

  That is, a (meth) acrylic acid, a (meth) acrylic acid monomer having a phosphate ester, a compound having an anionic functional group having a sulfonic acid group and a (meth) acrylic acid monomer having a polyethylene glycol chain are condensed or The compound produced by polymerization is a suitable anionic compound having the above two colloid protection mechanisms.

  Especially, anionic compound (X1) polymerizes at least a (meth) acrylic acid ester having a polyethylene glycol chain having a weight average molecular weight of 100 to 2,000 and a (meth) acrylic acid ester having a phosphate group. When the compound has a weight average molecular weight of 3,000 to 15,000, it has a high ability to stabilize nanoparticles of noble metals, silver and copper, and is a preferable protective agent.

  When the surface of the object to be plated is cationic, the metal nanoparticles (Y) combined with such an anionic compound (X1) can be effectively adsorbed on the surface, and simply immersed in the solution, It becomes possible to adsorb the metal nanoparticle composite at a high concentration. In addition, the metal nanoparticle composite can be evenly adsorbed to minute recesses and through / non-through holes regardless of the shape of the object to be plated. Is possible.

  The anionic compound (X1) used in the present invention may be any one obtained by copolymerizing the above-mentioned two types of monomers. For example, commercially available 2-methacryloyloxyphosphate (for example, Kyoeisha Chemical's light ester P-1M) and a commercially available methacrylic acid ester monomer having a polyethylene glycol chain (for example, NOF's Blemmer PME-1000) can be arbitrarily initiated. The aforementioned compound (X1) can be obtained by copolymerization with an agent (for example, an oil-soluble azo polymerization initiator V-59).

  At this time, from the viewpoint of achieving both the adsorption of the anionic compound (X1) to the surface of the metal nanoparticles and the dispersion stability of the metal nanoparticles, the mass fraction of the (meth) acrylate monomer having a phosphate monoester Is preferably 5% or more and less than 30% with respect to the total polymerizable monomer.

  In order to adjust the weight average molecular weight of the anionic compound (X1) to the above range, a chain transfer agent described in a patent document (Japanese Patent Laid-Open No. 2010-265543) or the like may be used. You may control by polymerization conditions, without using.

<Cationic compound (X2)>
The metal nanoparticle composite used in the present invention is a composite of a cationic compound (X2) and metal nanoparticles (Y), which is a composition dispersed in an aqueous medium.

  Examples of the cationic compound (X2) used here include phthalocyanine compounds, alkylamines, alkyldiamines, or mixtures of alkylamines and alkyldiamines.

  Here, as the phthalocyanine compound, “2,3,9,10,16,17,23,24-octakis [(2-N, N-dimethylaminoethyl) thio] phthalocyanine” (OTAP), “2,3 , 11, 12, 20, 21, 29, 30-octakis [(2-N, N-dimethylaminoethyl) thio] naphthalocyanine "(OTAP).

  Here, the alkylamine means an alkylamine having one amino group, and the alkyldiamine means an alkylamine having two amino groups. For example, when the metal nanoparticles (Y) are silver nanoparticles, in the synthesis of the composite, the proportion of the alkyldiamine in the amine for forming a complex compound with the silver compound is appropriately determined according to the purpose of mixing. However, in order to ensure low-temperature sinterability of the coated silver nanoparticles, the content is preferably 90 mol% or less, and more preferably 70 mol% or less. Further, in order to increase the reaction rate when forming a complex compound with a silver compound, and from the viewpoint of performing thermal decomposition of the complex compound in a short time at a low temperature, 10% mol% or more, preferably 20% mol% or more alkyl. It is preferable to use diamine mixed with alkylamine. When an alkyldiamine and an alkylamine are added to form a complex compound of a silver compound and an amine, the molar ratio between the silver atoms contained in the silver compound and the total amount of the alkylamine or alkyldiamine is about 1: 1 to 4 It is preferable to do.

<Metal nanoparticle composite>
As the metal nanoparticle composite of the present invention, a known metal nanoparticle composite that exhibits conductivity only by drying at room temperature or by low-temperature heating at 100 ° C. or lower after drying at room temperature can be used.

  A composite of metal nanoparticles using the anionic compound (X1) as a colloid protective agent can also be suitably used. This is done by dissolving or dispersing the anionic compound (X1) synthesized by the above-mentioned method in an aqueous medium, and then adding a metal compound such as silver nitrate, copper acetate, palladium nitrate, etc., and complexing as necessary. These metal compounds are reduced by mixing a reducing agent together with a complexing agent or simultaneously with a complexing agent to reduce these metal compounds, and the reduced metal becomes nano-sized particles (on the order of nanometers). At the same time, an aqueous dispersion of metal nanoparticles (Y) combined with the anionic compound (X1) can be obtained.

  A composite of metal nanoparticles using the cationic compound (X2) as a colloid protective agent can also be suitably used. For example, gold nanoparticles described in the patent document (WO11 / 114713) can be given as examples using the above-mentioned phthalocyanine compounds, and silver nanoparticles described in the patent document (Japanese Patent Application Laid-Open No. 2010-265543) can be given as examples using alkylamines. Examples thereof include particles, and these can be suitably used in the present invention.

  In the present invention, an aqueous dispersion of a complex with metal nanoparticles obtained by such a method may be used as it is, or an excess complexing agent, a reducing agent, or a silver compound used as a raw material. The counter ions contained therein are subjected to a purification step in which various purification methods such as ultrafiltration, precipitation, centrifugation, vacuum distillation, and vacuum drying are carried out alone or in combination of two or more, and the concentration ( Non-volatile components) or aqueous media may be used and newly prepared as a dispersion may be used.

  The metal nanoparticle composite is composed of the above-mentioned metal nanoparticle protective compound (X) and metal nanoparticles having an average particle diameter of 1 to 100 nm.

  The size of the metal nanoparticles (Y) contained in the metal nanoparticle composite can be estimated by a transmission electron micrograph, and the average value of 100 particles is in the range of 0.5 to 100 nm. Can be easily obtained by following the methods of Japanese Patent No. 4697356 and Japanese Patent Application Laid-Open No. 2010-209421. Each of these metal nanoparticles exists independently, is protected by the compound (X), and does not melt at room temperature and exists stably. In particular, in the present invention, it is preferable to use one having an average particle diameter of 5 to 50 nm from the viewpoint of obtaining a denser and uniform plated substrate.

  The particle size of the metal nanoparticle (Y) is the type of metal compound, the molecular weight of the metal nanoparticle protective compound (X) as a colloid protective agent, the structure, the use ratio, the type of complexing agent and reducing agent, and the amount used. The temperature can be easily controlled by the temperature during the reduction reaction.

  Moreover, when using an anionic compound (X1) as a metal nanoparticle protection compound (X) for the said metal nanoparticle composite_body | complex, it is preferable that the ratio is 2-10 mass% in a composite_body | complex. That is, in this metal nanoparticle composite, the metal nanoparticle occupies most of the weight, so that the composite with the metal nanoparticle can be stably adsorbed to the object to be plated. In the plating process, it is easy to perform uniform plating.

  Such a metal nanoparticle composite can be uniformly dispersed in an aqueous medium, that is, a mixed solvent of water or an organic solvent compatible with water in a range of about 0.01 to 70% by mass. is there. Further, the dispersion can be stably stored at room temperature (˜25 ° C.) without aggregation for at least several months.

  When the metal nanoparticle composite is used as an aqueous dispersion for forming a metal conductor layer, its concentration (nonvolatile content concentration) is in the range of 5 to 200 g / L from the viewpoint of securing the amount of adsorption to the object to be plated. It is preferable that

  The complex of the anionic compound (X1) and the silver nanoparticles is most preferable because the solution has high stability, can exhibit sufficient conductivity, and has high economic efficiency. At this time, silver nanoparticles having an average particle diameter of 0.5 to 100 nm can be preferably used, but preferably 1 to 30 nm.

<Adsorption process>
The “adsorption” in the step (I) of the present invention is only required to be in a state where the metal nanoparticle composite is in contact with the object to be plated. As a method for achieving such a state, a coating method, a printing method, etc. Any conventionally known method can be used.

  Examples of the coating method include a dip coating method (dipping method), a spray coating method, a spin coating method, a bar coating method, and a die coating method.

  Examples of printing methods include screen printing, offset printing, gravure printing, flexographic printing, and ink jet printing.

  Among these, it is preferable to perform the treatment by the dipping method from the viewpoint of the properties of the metal nanoparticle composite and the ability to easily adsorb the object to be plated having a complicated shape. The conditions are not particularly limited, but the immersion time is preferably about 1 second to 10 minutes, and more preferably in the range of 1 second to 5 minutes.

<Heating process>
When the metal nanoparticle composite is adsorbed on the object to be plated as described above, a conductive film is formed. Although the drying temperature at this time is not specifically limited, it is preferable to heat at 100 ° C. or less because the electrical resistivity of the conductive film decreases as the temperature increases and the range of substrate selection increases as the temperature decreases. The heat drying time may be a time during which the resin molded product is dried and a conductive film of a level necessary for performing electroplating in a subsequent process is obtained. Moreover, in order to shorten heat drying time, it is preferable to carry out under ventilation.

  When the metal nanoparticle-protecting compound (X) is an anionic compound (P1) (see Synthesis Example 1), it is particularly preferable in that it can be dried at a low temperature. You may make it dry under and may heat and dry. The temperature for heating is preferably 100 ° C. or lower, and more preferably in the range of 20 ° C. to 100 ° C.

<Electroplating process>
As the electroplating solution and the electroplating step, any of various conventionally known electroplating solutions and steps can be used.

<Plating>
In addition to various chemical, electrical, magnetic, optical, and colorant properties of the metal nanoparticles (Y), the plated product obtained in the present invention is a metal nanoparticle protective compound that is an organic component. (X) has properties such as moldability, film-forming property, adhesiveness and flexibility. The application is not limited, and can be used in a very wide range of fields such as electronic materials, magnetic materials, optical materials, and various sensors.

  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 analytical instruments used in the present invention are as follows.
¹ H-NMR: manufactured by JEOL Ltd., AL300, 300 Hz
TEM observation: JEM-2200FS, manufactured by JEOL Ltd.
(Electrical conductivity: manufactured by HORIBA, Ltd., B-173)
SEM observation: KEY-9800, VE-9800
TG-DTA measurement: TG / DTA6300, manufactured by SII Nano Technology Co., Ltd.
Plasmon absorption spectrum: manufactured by Hitachi, Ltd., UV-3500
Dynamic scattering particle size measuring device: FPAR-1000 manufactured by Otsuka Electronics Co., Ltd.
Surface resistivity measurement: Mitsubishi Chemical Corporation, low resistivity meter Loresta EP (4-terminal method)
GPC: Tosoh Corporation HLC-8220

[Synthesis of aqueous dispersion of complex of anionic compound (X1) and metal nanoparticles (Y)]
The complex of the compound having an anionic functional group and the metal nanoparticle used in the present invention, and the aqueous dispersion thereof were carried out as follows based on JP2010-209421A and JP4697356A.

<Synthesis Example 1 Anionic Compound: Synthesis of Compound (P1) Having Phosphate Group>
Under a nitrogen atmosphere, 210 g of ethanol and 174 g of 2-butanone were placed in a reaction vessel and heated to 75 ° C. with stirring. Here, 120 g of light ester P-1M (manufactured by Kyoeisha Chemical Co., Ltd.), 450 g of Blemmer PME-1000 (manufactured by NOF Corporation), and 30 g of BLEMMER PME-100 (manufactured by NOF Corporation) are added to 90 g of ethanol and 90 g of 2-butanone. The dissolved mixed solution was dropped over 3.5 hours, and 3 g of a polymerization initiator (V-59) and 18 g of a chain transfer agent (methyl 3-mercaptopropionate) were dissolved in 30 g of 2-butanone. It was dripped simultaneously over 5 hours. Heating was stopped 21 hours after the start of the reaction, and after cooling to room temperature, 300 g of distilled water was added. The solvent was distilled off under reduced pressure using a rotary evaporator, 100 g of distilled water was added and distilled under reduced pressure again, and the remaining liquid was filtered through a polypropylene mesh to obtain an aqueous solution of a compound (P1) having a phosphate group as an anionic functional group. (950 g, nonvolatile content 62.6%, acid value 99).

The measurement result of ¹ H-NMR of the obtained product is shown below.
¹ H-NMR (CD ₃ OD) measurement results:
δ (ppm): 3.85 to 4.45 (bs), 3.45 to 3.75 (bs), 3.20 to 3.40, 2.65 to 2.95 (bs), 2.40 to 2.65 (bs), 1.75 to 2.35 (bs), 0.75 to 1.50 (m)

The measurement result of GPC of the obtained product is shown below.
GPC measurement conditions:
Column: TSK-GEL HXL-H + G5000HXL + G3000HXL + G2000HXL
Size: 7.8 mmI. D. × 30cm Exclusion limit molecular weight 4 million in polystyrene conversion Temperature: 40 ° C Column thermostat Solvent: THF grade 1 (Wako Pure Chemical Industries)
Flow rate: 1 mL / min
Sample: solid content concentration 0.5 wt%, THF solution, injection volume 50 μL
Calibration curve: TSK standard polystyrene (Tosoh) cubic approximation formula

GPC analysis method:
When the GPC profile consists of a plurality of peaks including peaks derived from the raw material, the analysis was performed excluding the low molecular weight component derived from the raw material. That is, the components detected on the higher molecular weight side than the “high molecular weight side ridge” of the peak of PME-1000 (near Mw 1,100), which is the raw material with the largest weight average molecular weight among the raw materials used in Synthesis Example 1, The weight average molecular weight Mw was calculated as a calculation target. When the component to be calculated includes a plurality of peaks, Mw was calculated by combining them.

GPC measurement results:
Mw: 8,900

<Synthesis Example 2 Synthesis of aqueous dispersion of composite of phosphoric acid group-containing compound (P1) and silver nanoparticles>
In a reaction vessel, 15.5 g of the aqueous solution of the compound (P1) obtained in Synthesis Example 1 is mixed with 31 g (0.35 mol) of 2-dimethylaminoethanol, 34 g (0.35 mol) of 65% nitric acid, and 39 g of distilled water. A solution in which 150 g of silver nitrate was dissolved in 150 g of distilled water was added, and finally 34.5 g (0.39 mol) of 2-dimethylaminoethanol was added. The reaction vessel was immersed in an oil bath and heated at an internal temperature of 50 ° C. for 4 hours to obtain a brownish black dispersion.

The dispersion obtained after completion of the reaction was subjected to ultrafiltration purification using a hollow fiber UF membrane module (manufactured by Daisen Membrane Systems Co., Ltd., membrane area 0.13 m ² ). The electrical conductivity of the filtrate was initially 20 mS / cm or more, and the ultrafiltration was terminated when it became 10 μS / cm or less. Next, in order to remove coarse particles from this residual component, suction filtration was performed with a membrane filter having a pore size of 0.45 μm to obtain an aqueous dispersion of a complex with silver nanoparticles as a filtrate (1,029 g, non-volatile content). 9.9%, yield 97%). The filtrate (coarse particles) at this time was 135 mg (0.14% in terms of silver of the raw material).

  When the obtained dispersion is sampled and becomes a 10-fold diluted solution, a yellow-brown solution is obtained. When the visible absorption spectrum is measured, a plasmon absorption spectrum peak is observed at 400 nm, confirming the formation of silver nanoparticles. did. Moreover, spherical silver nanoparticles (average particle diameter of 6.8 nm) were confirmed by TEM observation. As a result of measuring the silver content in the solid using TG-DTA, it was found to be 93.5%. From this, the content of the compound (P1) in the silver nanoparticle composite is estimated to be 6.5%. I was able to.

[Relationship between drying temperature and electrical resistivity of composite of phosphoric acid group-containing compound (P1) and silver nanoparticles]
The glass slide was immersed in a 1% aqueous solution of polyethyleneimine 10000 (manufactured by Junsei) for 10 seconds, washed with water, immersed in an aqueous silver nanoparticle composite dispersion (about 10%) for 1 second, taken out, and dried in cold air. Next, heat treatment was performed at a predetermined temperature and time, the sheet resistance and film thickness were measured, and the electrical resistivity was calculated from these values. The sheet resistance and film thickness were measured at three locations for each sample, and Table 1 lists the average values.

As shown in Table 1, after the silver nanoparticle composite aqueous dispersion is adsorbed on the substrate, it is dried at room temperature (20 ° C.) or heated at a predetermined temperature of 100 ° C. or lower in addition to drying. A sufficient conductive film was obtained for the treatment.
In order to confirm the adhesion between the object to be plated and the conductive film, a tape peeling test was performed.
After pressing the adhesive tape (manufactured by Nichiban Co., Ltd.) with a thumb firmly on the surface of the conductive film formed on the surface of the object to be plated, the adhesive tape was peeled off at once. No peeling of the conductive film was observed. It was.

Example 1
An ABS resin substrate (5 cm × 10 cm) was immersed in a 1% aqueous solution of polyethyleneimine 10000 (manufactured by Junsei Kagaku) for 2 minutes, taken out, and washed with water for 2 minutes. Subsequently, it was immersed in a 20% silver nanoparticle composite dispersion for 2 minutes, taken out and dried. When this was heated at 100 ° C. for 5 minutes, a silver conductive film having a sheet resistance of 1.6Ω / □ was obtained.
The ABS resin with a conductive film is pickled with 98% sulfuric acid 50 mL / L for 1 minute, and electroplated with a copper sulfate plating bath (CuSO ₄ .5H ₂ O 70 g / L, H ₂ SO ₄ 200 g / L) (current 2 0.5 A / dm ² , 30 minutes). Uniform copper plating films were formed on both sides, and the thickness was 15 μm.

Example 2
An ABS resin substrate (5 cm × 10 cm) was immersed in a 1% aqueous solution of polyethyleneimine 10000 (manufactured by Junsei Kagaku) for 2 minutes, taken out, and washed with water for 2 minutes. Subsequently, it was immersed in a 10% silver nanoparticle composite dispersion for 2 minutes, taken out and dried. When this was heated at 50 ° C. for 5 minutes, a silver conductive film having a sheet resistance of 4Ω / □ was obtained.
The ABS resin with a conductive film is pickled with 98% sulfuric acid 50 mL / L for 1 minute, and electroplated with a copper sulfate plating bath (CuSO ₄ .5H ₂ O 70 g / L, H ₂ SO ₄ 200 g / L) (current 2 0.5 A / dm ² , 30 minutes). Uniform copper plating films were formed on both sides, and the thickness was 15 μm.

From the above, according to the method of the present invention, the conductive film can be easily formed on the surface of the object to be plated having a simple process, a complicated shape, or the object to be adversely affected by heat treatment, A plated product having a desired thickness was obtained by electroplating.
In addition, before the electroplating treatment, a tape peeling test was performed to confirm the adhesion between the object to be plated and the conductive film. After pressing the adhesive tape (manufactured by Nichiban Co., Ltd.) with a thumb firmly on the surface of the conductive film formed on the surface of the object to be plated, the adhesive tape was peeled off at once. No peeling of the conductive film was observed. It was.

Claims (8)

(I) a step of adsorbing a metal nanoparticle composite containing the metal nanoparticle protective compound (X) and the metal nanoparticle (Y) on the surface of the object to be plated;
(II) a step of drying the object to be plated on which the metal nanoparticle composite obtained in the step (I) is adsorbed;
(III) A method for producing a plated product, comprising a step of performing electroplating on an object to be plated having a conductive film formed on the surface obtained in the step (II). The manufacturing method of Claim 2 whose said metal nanoparticle protection compound (X) is an anionic compound (X1) or a cationic compound (X2). The anionic compound (X1) is obtained by polymerizing at least a (meth) acrylic acid ester having a polyethylene glycol chain having a weight average molecular weight of 100 to 2,000 and a (meth) acrylic acid ester having a phosphate group. The production method according to claim 1 or 2, wherein the compound has a weight average molecular weight of 3,000 to 15,000. The production method according to claim 1 or 2, wherein the cationic compound (X2) is a phthalocyanine compound, an alkylamine, an alkyldiamine, or a mixture of an alkylamine and an alkyldiamine. The manufacturing method as described in any one of Claims 1-3 which has the process of cationizing the to-be-plated object surface with a cationization processing agent before performing the said process (I). The manufacturing method according to any one of claims 1 to 5, wherein the step of adsorbing the metal nanoparticle composite in the step (I) is a step of immersing an object to be plated in the metal nanoparticle composite dispersion. . The said metal nanoparticle (Y) is a silver nanoparticle, The manufacturing method as described in any one of Claims 1-6. A plated article obtained by the production method according to claim 1.