TWI449804B - Metal layer-coated substrate and process for the production thereof - Google Patents

Description

Substrate coated metal layer and method of producing the same

The present invention relates to a substrate which can be used for a coated metal layer such as a conductive material or an electromagnetic wave sealing material, and a method for producing the same.

The method of coating a metal on a non-conductive substrate is generally an electroless plating method. An electroless plating method, for example, a method of forming a metal layer by immersing a substrate in an electroless plating solution containing a metal salt, a metal complex, a pH adjuster, a reducing agent, etc. (for example, refer to "electroless plating - basis and application - , 4th edition, compilation of gold-plated research conference, publication of the Nikkan Kogyo Shimbun, and issue date October 1999, pages 101~127).

In general, when a substrate coated with a metal layer is produced by electroless plating, it is necessary to perform a process called an activation treatment to cause a catalyst which is electrolessly plated to adhere to a substrate to activate the surface of the substrate. The pretreatment process is generally carried out as follows.

Before the substrate is subjected to electroless plating, it is contacted with an aqueous solution of tin chloride to adsorb tin ions, and then contacted with an aqueous solution of palladium chloride to adsorb a palladium colloid on the surface of the substrate by reduction of tin ions. The palladium gel system acts to start the electroless plating catalyst.

After the activation treatment, the substrate is immersed in an electroless plating bath containing a component other than a reducing agent such as a metal salt, a metal complexing agent, or a pH adjuster, and then a reducing agent is added or the substrate is immersed in a metal-containing material. In the electroless plating bath of a metal salt such as a complexing agent or a pH adjusting agent and a component other than the reducing agent, a metal layer is formed on the surface of the substrate by adding a reducing agent and a metal salt.

When the metal layer is deposited on the surface of the substrate by the above method, the distribution of tin or palladium is uneven due to the difference in adsorptivity or the like during the activation treatment of the surface of the substrate, and the surface potential is not uniform. Therefore, in the electroless plating, the metal layer generates a portion which is easily precipitated and a portion which is hard to be precipitated, and only a portion of the metal layer is formed, and an unprecipitated portion is generated, and a portion which exposes the surface of the substrate is generated. Therefore, there is a problem in that the substrate of the obtained metal layer to be coated cannot ensure stable conductivity. In addition, since the tin salt used in the activation treatment process is corrosive, in order to remove the residual tin salt, it is necessary to wash it before the start of electroless plating, but when it is washed frequently, there may be until The palladium colloid is reduced and it is difficult to perform electroless plating.

The present invention has been made in view of the above circumstances, and provides a substrate having a coated metal layer having a stable electrical conductivity, and the substrate of the coated metal layer is manufactured at a low cost and in a simple process without using a special equipment or device. The method of having less impact on the environment is for the purpose.

As a result of further intensive studies by the inventors of the present invention, it has been found that a substrate or a dispersion or layer of metal nanoparticles formed on the substrate via a chelating coupling agent containing a chelating forming functional group is used. a substrate of a novel metal-clad layer of a metal layer formed on a dispersion of a metal nanoparticle or a layer, by a substrate and a decane coupling agent containing a hydrolysis catalyst, a chelate-forming functional group, and a metal After contact with the aqueous solution of the nanoparticle-forming metal salt, it is treated with a reducing agent, and a dispersion or layer of metal nanoparticles is formed on the substrate via a decane coupling agent containing a chelating forming functional group, and then The present invention is completed by forming a metal layer on the dispersion or layer of the metal nanoparticle and obtaining a stable electrical conductivity of the substrate of the obtained metal layer.

In other words, the present invention provides (1) a substrate coated with a metal layer, characterized by comprising a substrate and metal nanoparticles formed on the substrate via a decane coupling agent containing a chelating forming functional group. A dispersion or layer, a metal layer formed on the dispersion or layer of the metal nanoparticle.

(2) The substrate of the metal-clad layer according to (1) above, wherein the substrate is formed by grouping at least one selected from the group consisting of ceria, ceramics, and glass.

(3) The substrate of the metal-clad layer according to the above (1) or (2), wherein the shape of the substrate is one selected from the group consisting of a spherical shape, a rod shape, a plate shape, a needle shape, a hollow shape, and a non-specific shape. Group of people.

(4) The substrate of the metal-clad layer according to (3) above, wherein the shape of the substrate is a fine particle shape having an average particle diameter of 0.1 to 100 μm.

(5) The base material of the metal-clad layer according to any one of the above-mentioned items, wherein the chelating-forming functional group has at least one selected from the group consisting of a nitrogen atom, a sulfur atom and an oxygen atom. The functional groups of a group of atoms.

(6) The substrate of the metal-clad layer according to the above (5), wherein at least one of the chelate-forming functional groups is selected from the group consisting of -SH, -CN, -NH ₂ , -SO ₂ OH, -SOOH, - A functional group of OPO(OH) ₂ and -COOH.

(7) The base material of the metal-clad layer according to any one of the above-mentioned, wherein the metal nanoparticles are in a group of at least one selected from the group consisting of gold, silver, copper, and nickel. Nanoparticles made of metal.

The substrate of the metal-clad layer according to any one of the above-mentioned items, wherein the metal layer is a layer made of silver.

(9) A method for producing a substrate coated with a metal layer, characterized in that after contacting the substrate with an aqueous solution containing a hydrolysis catalyst, a decane coupling agent containing a chelating forming functional group, and a metal nanoparticle forming metal salt Forming a dispersion or layer of metal nanoparticles through a decane coupling agent containing a chelating forming functional group on the substrate by treatment with a reducing agent, and then dispersing the metal nanoparticles Or a metal layer is formed on the layer.

(10) A method for producing a substrate coated with a metal layer according to (9) above, wherein the metal layer is formed by electroless plating.

By forming a dispersion or layer of metal nanoparticle on the substrate by the present invention, starting from each metal nanoparticle, a metal layer can be easily formed on the dispersion or layer of the metal nanoparticle. When a layer of metal nanoparticle is formed on the substrate, even if an unformed portion of the metal layer is formed on the metal nanoparticle layer, the resulting coated metal is present due to the presence of the metal nanoparticle layer between the substrate and the metal layer. The substrate of the layer is not exposed below the surface of the substrate, ensuring stable electrical conductivity.

Further, the present invention can provide a method in which the substrate of the above-mentioned metal-clad layer is produced in a low-cost and simple process without using a special equipment or apparatus, and which has little influence on the environment.

[In order to implement the best form of the invention]

First, a substrate relating to the coated metal layer of the present invention will be described.

The substrate for covering a metal layer of the present invention is characterized by comprising a substrate and a dispersion or layer of metal nanoparticles formed on the substrate via a decane coupling agent containing a chelating forming functional group, a metal layer formed on the dispersion or layer of the metal nanoparticle.

The substrate used in the substrate for coating a metal layer of the present invention preferably has an OH group on the surface of the substrate and interacts with a decane coupling agent, for example, at least one or more selected from the group consisting of Oxide, ceramics and glass are grouped together.

The cerium oxide is, for example, dry cerium oxide (crystalline halide) which is completely crystallized, water-dispersed cerium oxide (colloidal cerium oxide) or the like.

Further, ceramics such as alumina, sapphire, mullite, titania, tantalum carbide, tantalum nitride, aluminum nitride, zirconia, and the like.

Glass such as BK7, SF11, LaSFN9 and the like various kinds of sandblasted glass, optical round glass, alkali glass, soda lime glass, low expansion borosilicate glass, and the like.

Further, in addition to the above, the substrate may be a resin such as a polyoxyalkylene resin, a phenol resin, a natural modified phenol resin, an epoxy resin, or a polyvinyl alcohol under the conditions of interaction with a decane coupling agent. a resin, a cellulose resin, a polyamide resin, or a polyolefin resin, a styrene resin, an acrylic resin, or the like, or a modified product thereof or a surface treatment by corona discharge or the like Things.

The shape of the substrate is not particularly limited, and may be at least one selected from the group consisting of a spherical shape, a particle shape, a bead shape, a rod shape, a plate shape, a needle shape, a powder form, a hollow shape, a hollow fiber shape, and an unspecified shape. The group is better. The shape of the substrate is preferably in the form of fine particles, and the average particle diameter is preferably from 0.1 to 100 μm, more preferably from 1 to 20 μm. Further, in the present specification, the average particle diameter means a volume average particle diameter, and the volume average particle diameter can be measured, for example, by a particle size distribution measuring instrument or the like.

When the surface of the substrate has irregularities, it is easy to carry out the underlayer treatment, which is preferable. The substrate is, for example, a wipe glass, a porous particle or the like. Further, the substrate is preferably oxidized on its surface.

In the substrate coated with the metal layer of the present invention, the decane coupling agent having a chelate-forming functional group existing between the substrate and the dispersion or layer of the metal nanoparticle described below has a chelate at one end of the molecule It forms a functional group and has a decyl alcohol (Si-OH) at the other end and/or a compound which hydrolyzed the hydrolyzable functional group of the stanol group imparted by the hydrolysis.

The chelate-forming functional group such as a polar group or a hydrophilic group is preferably a functional group having at least one atom selected from the group consisting of a nitrogen atom, a sulfur atom and an oxygen atom, and at least one selected from the group consisting of -SH and - The functional groups of CN, -NH ₂ , -SO ₂ OH, -SOOH, -OPO(OH) ₂ , -COOH are more preferred.

Further, the hydrolyzable functional group is, for example, an alkoxy group (-OR) directly bonded to a Si atom, and the R constituting the alkoxy group is a linear, branched or cyclic group having a carbon number of 1 to 6. Any alkyl group is preferred, and specifically, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, 2-butyl, 3-butyl, pentyl, hexyl , cyclopentyl, cyclohexyl and the like.

Specific examples of the chelating-forming functional group-containing decane coupling agent used in the substrate for coating the metal layer of the present invention, such as 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane , N-2-(aminoethyl)-3-aminopropyltrimethoxydecane, N-2-(aminoethyl)-3-aminopropyltriethoxydecane, as a decane coupling agent The 3-aminopropyltrimethoxydecane is more preferable in terms of cost and ease of handling.

In the metal layer-coated substrate of the present invention, the chelate-forming functional group at one end of the decane coupling agent is coordinately bonded to the metal nanoparticle, the decyl alcohol group at the other end of the decane coupling agent and the OH group on the surface of the substrate. interaction.

Therefore, the dispersion or layer of the metal nanoparticles can be stabilized and fixed on the substrate via the decane coupling agent.

In the base material of the metal-clad layer of the present invention, the metal nanoparticle is preferably a nanoparticle composed of at least one metal selected from the group consisting of gold, silver, copper and nickel. It is preferable to form a metal layer (a metal layer made of silver) by a silver mirror reaction on a metal nanoparticle, and it is preferable to use a metal nanoparticle as a gold nanoparticle in consideration of good dyeing property with silver.

The metal nanoparticles may be at least partially adhered to the substrate via a decane coupling agent, and the metal nanoparticles may be present in a state of being dispersed on the substrate to form a dispersion, or may be attached to the substrate to form a layer. The state of the object. When the metal nanoparticles are not adhered to the substrate in the same manner and are dispersed, the metal layer described below can be used as a starting point for various metal nanoparticles, and the following metal layer can be formed on the dispersion of the metal nanoparticles to ensure the obtained coating. The substrate of the metal layer has a stable electrical conductivity.

Further, when the metal nanoparticles are attached to the substrate in the same manner to form a layer, it is of course possible to form the following metal layer on the entire surface of the metal nanoparticle layer, assuming that even if an unformed portion of the metal layer is generated, A metal nanoparticle layer is present between the substrate and the metal layer, and the obtained metal layer-coated substrate is ensured to have stable conductivity without being exposed to the surface of the substrate.

Further, in the present specification, the metal nanoparticle refers to an extremely small particle made of a metal having a particle diameter of 100 nm or less. When the large volume atom of the same volume is compared with the surface group of the nano particle, since the surface area of the nano particle is large and the surface energy is large (the ratio of all energy is high), it is expected to have characteristics different from those of the conventional particle. However, in the base material of the metal-clad layer of the present invention, when the metal layer is formed by electroless plating, it is considered that the metal nanoparticle acts as a catalyst.

In the base material of the metal-clad layer of the present invention, the metal species constituting the metal layer formed on the metal nanoparticle layer is not particularly limited, and silver, gold, copper, and nickel are preferably used, and the metal layer is borrowed. It is preferably formed by a silver mirror reaction, so that the metal species constituting the metal layer is more preferably silver.

The base material of the metal-clad layer of the present invention can be produced by the method for producing a substrate coated with a metal layer of the present invention described below.

A method for producing a metal layer-coated substrate according to the present invention, characterized in that after the substrate is brought into contact with an aqueous solution containing a hydrolysis catalyst, a chelating coupling functional group-containing decane coupling agent, and a metal nanoparticle-forming metal salt, Forming a dispersion or layer of metal nanoparticles via a decane coupling agent containing a chelating forming functional group on the substrate by treatment with a reducing agent, and then spreading the metal nanoparticle or A metal layer is formed on the layer.

The substrate used in the method for producing a metal layer-coated substrate of the present invention is, for example, the same as the substrate described above for the metal layer of the present invention, such as ceria, ceramics, glass, various resins, and the like.

The hydrolysis catalyst used in the method for producing a metal layer-coated substrate of the present invention is not particularly limited, and examples thereof include organic acids such as acetic anhydride, glacial acetic acid, propionic acid, citric acid, formic acid, and oxalic acid, and aluminum alkyl acetate. An aluminum chelate compound, an inorganic basic compound such as ammonium water, or the like. Among these, ammonium hydroxide is preferred in view of its reactivity with the 3-aminopropyltrimethoxydecane of the decane coupling agent and cost.

The chelating-forming functional group-containing decane coupling agent used in the method for producing a metal layer-coated substrate of the present invention has a chelate-forming functional group at one end of the molecule and a decane at the other end as described above. And/or by hydrolysis to impart a hydrolyzable functional group to the stanol group.

The chelate-forming functional group may be, for example, the same as the above, or may be provided in the form of a salt of each of the above functional groups. When the functional group is an acidic group such as -OH, -SH, -SO ₂ OH, -SOOH, -OPO(OH) ₂ or -COOH, the salt thereof is an alkali metal salt such as sodium, potassium or lithium, or an ammonium salt or the like. . Further, when it is a basic group such as -NH ₂ , the salt thereof is, for example, an inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid, an addition salt of an organic acid such as formic acid, acetic acid, propionic acid or trifluoroacetic acid.

Further, the hydrolyzable functional group can be, for example, the same as those described above for the base material of the coated metal layer of the present invention.

The metal species constituting the metal nanoparticle-forming metal salt used in the method for producing a metal layer of the coated metal layer of the present invention is the same as that described above for the substrate of the metal layer of the present invention, for example, gold or silver. , copper, nickel, etc. Metal salts such as gold chloride acid, silver nitrate, copper sulfate, nickel sulfate, and the like.

The aqueous solution to be used in the method for producing a metal layer of the metal layer of the present invention is not particularly limited as long as it is water-based, and may contain a water-water mixed organic compound. Here, examples of the water-miscible organic compound include low-alcohols such as methanol, ethanol, propanol, and butanol, and ketones such as acetone. In this case, the water-miscible organic compound may be used alone or in combination of two or more kinds with water.

The reducing agent is suitably used in consideration of the oxidation-reduction potential of the metal component of the metal nanoparticulate metal salt to be used. The reducing agent is not particularly limited as long as it is obtained by dissolving in an aqueous solution, and may be appropriately selected from the above-mentioned conventional reducing agents. The reducing agent is, for example, an inorganic reduction such as a borohydride such as sodium tetrahydroborate or an alkali metal hydride borate such as sodium borohydride or an ammonium hydride borate; a hydrazine compound or a hypochlorite. An organic reducing agent such as a formaldehyde, formaldehyde, acetaldehyde, citric acid or sodium citrate. These reducing agents may be used alone or in combination of two or more.

In the method for producing a substrate coated with a metal layer according to the present invention, the dispersion or layer of the metal nanoparticle is formed by contacting the substrate with a decane containing a hydrolysis catalyst and a chelating forming functional group. The coupling agent and the aqueous solution of the metal nanoparticle-forming metal salt are treated with a reducing agent. In a specific method, for example, a solution containing a chelating-forming functional group-containing decane coupling agent and a metal nanoparticle-forming metal salt is added to an aqueous solution (liquid A) containing a substrate and a hydrolyzable catalyst (solution B) After stirring, a solution containing a reducing agent (liquid C) is dropped into the mixed solution, and heating and stirring are carried out.

The temperature at which the liquid A and the liquid B are mixed and stirred is preferably 10 to 40 ° C, and the stirring time is preferably 1 to 30 minutes. The heating temperature after dropping the liquid C into the mixture of the A liquid and the B liquid is preferably 30 to 70 ° C, and the heating time is preferably 2 to 5 hours.

For a 1 molar chelating coupling functional decane coupling agent, the amount of the hydrolysis catalyst used is preferably 0.5 to 5.0 moles, more preferably 1.5 to 2.5 moles. Further, the metal nanoparticle-forming metal salt is preferably used in an amount of from 0.005 to 0.05 mol, more preferably from 0.015 to 0.025 mol, per mole of the decane coupling agent having a chelate-forming functional group. Further, for the 1 mol metal nanoparticle-forming metal salt, the reducing agent is preferably used in an amount of 0.025 to 0.25 mol, more preferably 0.075 to 0.125 mol.

In the method for producing a substrate coated with a metal layer of the present invention, a metal layer is formed on the dispersion or layer of the metal nanoparticle as a final process.

As the metal forming the metal layer, silver, gold, copper, nickel, or the like as described above can be used.

The method for forming the metal layer is preferably an electroless plating method, and the silver mirror reaction is more preferable in consideration of the progress of the reaction and the stability.

As described above, when a layer in which metal nanoparticles are attached to the substrate in the same manner is formed, the metal layer does not necessarily have to be coated on the entire surface of the metal nanoparticle layer.

In the method for producing a substrate coated with a metal layer according to the present invention, a dispersion of a stabilized metal nanoparticle or a layer is formed by coating a substrate with a decane coupling agent, and then forming a metal by electroless plating. The layer may form a metal layer on the substrate under an activation treatment process that does not necessarily have to be on the surface of the substrate for general electroless plating. Further, when a layer of metal nanoparticle is formed on a substrate, it is assumed that even if an unformed portion of the electroless plating layer of the metal layer is formed on the metal nanoparticle layer, metal exists between the substrate and the metal layer. Since the nanoparticle layer is formed, the substrate of the obtained metal layer can be ensured to have stable conductivity without exposing the surface of the substrate. Further, the substrate on which the metal layer is coated can be produced with little influence on the environment at a low cost and in a simple process without using a special equipment or apparatus.

[Examples]

Next, the present invention will be described in more detail by way of examples, but the invention is not limited by the examples.

Example 1 (Production Example of Cerium Oxide Particles Covered with Silver Layer)

(1) Formation of a layer of gold nanoparticles on cerium oxide particles 10 g of cerium oxide particles (average particle diameter: 6.4 μm) was placed in a 500 mL Erlenmeyer flask, and 63 g of isopropyl alcohol (IPA) was added thereto, and ultrasonic treatment was performed for 10 minutes. . Further, 63 g of methanol was added, and the mixture was stirred for 10 minutes with a magnetic stirrer, and 50 g of a 25% aqueous ammonium solution was added thereto, and the mixture was stirred in an oil bath at 30 ° C for 10 minutes (the solution was used as the solution A).

Add 50 mL of methanol to 0.23 g of gold chloride acid (HAuCl ₄ .4H ₂ O), stir for 10 minutes with a magnetic stirrer, then add 4.5 mL of 3-aminopropyltrimethoxydecane, and stir for another 10 minutes. (This solution is used as the B solution).

50 mL of methanol was added to 0.107 g of sodium tetrahydroborate (NaBH ₄ ), and the mixture was stirred with a magnetic stirrer for 10 minutes (this solution was used as the C solution).

The liquid B was added to the liquid A, and the mixture was stirred at 30 ° C for 5 minutes. Then, when the liquid C was slowly dropped, the reaction system was changed to red. After dropping the liquid C, the oil bath was overheated at 65 ° C and stirred for 3 hours. Stirring was stopped, and methanol fractionation was carried out three times, and then suction filtration was carried out, and cerium oxide particles having a layer of gold nanoparticles formed thereon were taken, and dried in an oven at 70 ° C for 3 hours. The resulting particles are red in color.

An electron microscope (SEM) photograph of the obtained cerium oxide particles having a gold nanoparticle layer formed is shown in Fig. 1. As can be seen from Fig. 1, the gold nanoparticles are uniformly adhered to the entire surface of the ceria particles.

(2) Forming a silver layer on the layer of gold nanoparticles. 1 g of 200 g of water was added to the cerium oxide particles having the layer of gold nanoparticles formed in the above (1), and ultrasonic treatment was carried out for 10 minutes, and then 0.65 g was added. Silver nitrate was stirred with a magnetic stirrer for 10 minutes. After adding 13 mL of a 25% aqueous ammonium solution, 20 mL of a 0.24 mmol/L aqueous formaldehyde solution was added and stirred for 5 minutes. The precipitated silver-coated cerium oxide particles were taken by suction filtration, washed with methanol, and dried in an oven at 70 ° C for 3 hours.

An electron microscope (SEM) photograph of the obtained silver-coated cerium oxide particles is shown in Fig. 2. As can be seen from Fig. 2, a layer made of silver is laminated on the entire layer of the gold nanoparticle layer.

The resistance values of the 20 silver-coated cerium oxide particles were measured by a micro compression tester, and the average value thereof was determined. The results obtained and the standard deviation are shown in Table 1.

As is clear from the results of Table 1, the cerium oxide particles coated with the silver layer obtained in Example 1 had a low average value of 3.9 Ω and a standard deviation of 2.2, and the conductivity was stable.

Example 2 (Production Example of Polyimine Particles Covered with Silver Layer)

To a 500 mL Erlenmeyer flask, 3 g of polyimide particles (manufactured by Sumitomo Beyton, Inc.: average particle diameter: 0.5 μm) were added, and 63 g of isopropyl alcohol (IPA) was added thereto, and ultrasonic treatment was performed for 10 minutes. Separately, 63 g of methanol was added, and the mixture was stirred for 10 minutes with a magnetic stirrer, and 50 g of a 25% aqueous ammonium solution was added thereto, and the mixture was stirred at 30 ° C for 10 minutes in an oil bath (the solution was used as the solution A).

50 mL of methanol was added to 0.50 g of gold chloride acid (HAuCl ₄ .4H ₂ O), and the mixture was stirred for 10 minutes with a magnetic stirrer. Then, 7.0 mL of 3-aminopropyltrimethoxydecane was added, followed by stirring for 10 minutes. (This solution is used as the B solution).

50 mL of methanol was added to 0.23 g of sodium tetrahydroborate (NaBH ₄ ), and the mixture was stirred with a magnetic stirrer for 10 minutes (this solution was used as the C solution).

The liquid B was added to the liquid A, and the mixture was stirred at 30 ° C for 5 minutes. Then, when the liquid C was slowly dropped, the reaction system was changed to red. After dropping the liquid C, the oil bath was overheated at 65 ° C and stirred for 3 hours. Stirring was stopped, and methanol fractionation was carried out three times, and then suction filtration was carried out, and cerium oxide particles having a layer of gold nanoparticles formed thereon were taken, and dried in an oven at 70 ° C for 3 hours. The resulting particles are red in color.

After 0.5 g of water was added to 0.5 g of the obtained polyimine particles having the gold nanoparticle layer, and ultrasonic treatment was performed for 15 minutes, 0.67 g of silver nitrate was added, and the mixture was stirred for 10 minutes with a magnetic stirrer. After adding 20 mL of a 25% ammonium aqueous solution, 30 mL of a 0.24 mmol/L aqueous formaldehyde solution was added and stirred for 5 minutes. The polyimine particles which were subjected to suction filtration to take the precipitated silver layer were washed with methanol, and then dried in an oven at 70 ° C for 3 hours.

An electron microscope (SEM) photograph of the obtained silver-coated polyimide layer particles is shown in Fig. 3. As can be seen from Fig. 3, a layer made of silver is laminated on the entire layer of the gold nanoparticle layer.

Example 3 (Production Example of Titanium Oxide Powder Covered with Silver Layer)

To a 300 mL Erlenmeyer flask, 5 g of titanium oxide powder (manufactured by Ishihara Sangyo Co., Ltd.: ST-01) was added, and 31.5 g of isopropyl alcohol (IPA) was added thereto, and ultrasonic treatment was performed for 10 minutes. Further, 31.5 g of methanol was added, and the mixture was stirred for 10 minutes with a magnetic stirrer, and 25 g of a 25% aqueous ammonium solution was added thereto, and the mixture was stirred in an oil bath at 30 ° C for 10 minutes (this solution was used as the solution A).

Add 50 mL of methanol to 0.20 g of gold chloride acid (HAuCl ₄ .4H ₂ O), stir for 10 minutes with a magnetic stirrer, then add 2.2 mL of 3-aminopropyltrimethoxydecane, and stir for another 10 minutes. (This solution is used as the B solution).

50 mL of methanol was added to 0.092 g of sodium tetrahydroborate (NaBH ₄ ), and the mixture was stirred for 10 minutes with a magnetic stirrer (the solution was used as the C solution).

The liquid B was added to the liquid A, and the mixture was stirred at 30 ° C for 5 minutes. Then, when the liquid C was slowly dropped, the reaction system was changed to purple. After dropping the liquid C, the oil bath was overheated at 65 ° C and stirred for 3 hours. Stirring was stopped, and methanol fractionation was carried out three times, and then suction filtration was carried out, and titanium oxide powder in which a layer of gold nanoparticles was formed was taken, and dried in an oven at 70 ° C for 3 hours. The resulting particles were purplish red.

300 mL of water was added to 3.0 g of the obtained titanium oxide powder layer having the gold nanoparticle layer, and after ultrasonic treatment for 15 minutes, 0.67 g of silver nitrate was added, and the mixture was stirred for 10 minutes with a magnetic stirrer. After adding 20 mL of a 25% ammonium aqueous solution, 30 mL of a 0.24 mmol/L aqueous formaldehyde solution was added and stirred for 5 minutes. The titanium oxide particles of the precipitated silver coating layer were subjected to suction filtration, washed with methanol, and dried in an oven at 70 ° C for 3 hours.

As a result of observing the obtained titanium oxide powder of the coated gold nanoparticle layer by an electron microscope (SEM), it was found that a layer made of silver was laminated on the entire surface of the gold nanoparticle layer.

Example 4 (Production Example of Polypropylene Powder Covered with Silver Layer)

In the third embodiment, the silver-coated polypropylene powder was obtained by performing the same operation except that the titanium oxide was changed to 5 g of polypropylene powder (manufactured by Brym Polymer Co., Ltd.).

As a result of observing electron microscopy (SEM) of the obtained silver-coated polypropylene powder, it was found that a layer made of silver was laminated on the entire surface of the gold nanoparticle layer.

Example 5 (Production Example of Glass Plate Covered with Silver Layer)

In the third embodiment, the same operation was carried out except that the titanium oxide was changed to a 1 × 1 cm ² micro glass plate (manufactured by Matsuron Glass Co., Ltd.) in an Erlenmeyer flask, and a silver-coated glass plate was obtained.

As a result of observing the obtained silver-coated glass plate by an electron microscope (SEM), it was found that a layer made of silver was laminated on the entire surface of the gold nanoparticle layer.

Example 6 (Production Example of Hollow Fiber Type Nylon 12 Covered with Silver Layer)

In the third embodiment, except that the titanium oxide was changed to a hollow fiber-like Nylon 12 (manufactured by Ube Industries, Ltd.) with an inner diameter of 48 mm, an outer diameter of 50 mm, and a length of 2 cm, the same operation was performed to obtain a hollow silver coating. Fibrous resistant dragon 12.

As a result of observing an electron microscope (SEM) of the obtained silver-coated hollow fiber-shaped nylon 12, it was found that a layer made of silver was laminated on the entire layer of the gold nanoparticle layer.

Example 7 (Production Example of Using Cerium Oxide Particles with Gold Nanoparticles Attached to 3-Mercaptopropyltrimethoxydecane)

In Example 1 (1), the same operation was carried out except that 4.5 mL of 3-aminopropyltrimethoxydecane was changed to 4.5 mL of 3-mercaptopropyltrimethoxydecane. When compared with the cerium oxide particle in which the gold nanoparticle layer obtained in Example 1 (1) was formed, the sample which adhered the aggregated gold nanoparticle to the cerium oxide particle was prepared. The SEM photograph is shown in Fig. 4.

Example 8 (Example in which no silver layer is laminated on a portion of the layer of gold nanoparticles)

To 1 g of the cerium oxide particles having the gold nanoparticle layer obtained in Example 1 (1), 200 mL of water was added thereto, and ultrasonic treatment was carried out for 10 minutes. Then, 0.41 g of silver nitrate was added, and the mixture was stirred for 10 minutes with a magnetic stirrer. After adding 8.2 mL of a 25% aqueous ammonium solution, 12.6 mL of a 0.24 mmol/L aqueous formaldehyde solution was added and stirred for 5 minutes. The cerium oxide particles of the precipitated silver-coated layer were subjected to suction filtration, washed with methanol, and dried in an oven at 70 ° C for 3 hours.

An electron microscope (SEM) photograph of the obtained silver-coated cerium oxide particles is shown in Fig. 5. As can be seen from Fig. 5, there is no silver layer laminated on a portion of the layer of gold nanoparticles.

The resistance values of the 20 silver-coated cerium oxide particles were measured by a micro compression tester, and the average value thereof was determined. The results obtained and the standard deviation are shown in Table 2.

As can be seen from the results of Table 2, the silver dioxide-coated cerium oxide particles obtained in Example 8 had no silver layer laminated on the partial gold nanoparticle layer, but it was found that the average resistance was present by the layer of the gold nanoparticle. The value is a low value of 11.8 Ω.

Example 9 (Example of production of soda lime glass beads coated with a silver layer)

(1) Forming a layer of gold nanoparticles on soda-lime glass beads: In the same manner as in Example 1 (1), in soda lime, except that soda lime glass beads (particle size: 5 to 63 μm) were used instead of cerium oxide particles. A layer of gold nanoparticles is formed on the glass beads.

(2) Forming a Silver Layer on the Gold Nanoparticle Layer Using the soda lime glass beads having the above-described gold nanoparticle layer, the silver layer was formed on the entire surface of the gold nanoparticle layer in the same manner as in Example 1 (2). .

An electron microscope (SEM) photograph of the obtained silver-coated soda lime glass beads is shown in Fig. 6.

The resistance values of the soda lime glass beads of 20 coated silver layers were measured by a micro compression tester, and the average value thereof was determined. The results obtained and the standard deviation are shown in Table 3.

As is clear from the results of Table 3, the soda lime glass beads of the silver-coated layer obtained in Example 9 had a low average value of 14.3 Ω.

Example 10 (Production Example of Cerium Oxide Particles Covered with Silver Layer)

(1) Forming a layer of gold nanoparticles on cerium oxide particles, except that N-2 (aminoethyl)-3-aminopropyltrimethoxy decane is substituted for 3-aminopropyltrimethoxy decane, A gold nanoparticle layer was formed on the ceria particles in the same manner as in Example 1 (1). An electron microscope (SEM) photograph of the obtained cerium oxide particles having a gold nanoparticle layer formed is shown in Fig. 7. When compared with the cerium oxide particles in which the gold nanoparticle layer obtained in Example 1 (1) was formed, it was found that the condensed gold nanoparticles adhered to the cerium oxide particles.

(2) Forming a Silver Layer on the Gold Nanoparticle Layer Using the above-described cerium oxide particles having the gold nanoparticle layer formed thereon, a silver layer was formed on the entire surface of the gold nanoparticle layer in the same manner as in Example 1 (2). .

Example 11 (Production Example of Cerium Oxide Particles Covered with Silver Layer)

(1) Forming a silver nanoparticle layer on the ceria particles, except that 0.23 g of gold chloride acid (HAuCl ₄ .4H ₂ O) is substituted with 0.48 silver nitrate, and 0.107 g of NaBH _{4 is} changed to 0.092 g, In the same manner as in Example 1 (1), cerium oxide particles having a silver nanoparticle layer formed thereon were obtained. An electron microscope (SEM) photograph of the obtained cerium oxide particles having a silver nanoparticle layer formed is shown in Fig. 8.

(2) Formation of Silver Layer on Silver Nanoparticle Layer Using the above-described cerium oxide particles having a silver nanoparticle layer formed thereon, a silver layer was formed on the entire silver nanoparticle layer in the same manner as in Example 1 (2). .

Example 12 (Production Example of Cerium Oxide Particles Covered with Gold Layer)

500 g of water was added to 1 g of the cerium oxide particles having the gold nanoparticle layer obtained in Example 1 (1), and after ultrasonic treatment for 10 minutes, 0.25 g of gold chloride was added to make the aqueous solution alkaline. Further, 5 ml of a 2.5% aqueous ammonium solution was added, and the mixture was stirred for 10 minutes with a magnetic stirrer. 250 mL of a 1.87 mmol/L hydrazine hydroxymethylphosphine chloride aqueous solution as a reducing agent was slowly added dropwise. The cerium oxide particles of the precipitated gold layer were subjected to suction filtration, washed with methanol, and dried in an oven at 70 ° C for 3 hours.

An electron microscope (SEM) photograph of the obtained gold-coated cerium oxide particles is shown in Fig. 9.

The resistance values of the ten silver-coated cerium oxide particles were measured by a micro compression tester, and the average value thereof was obtained. The results obtained and the standard deviation are shown in Table 4.

As is clear from the results of Table 4, the ruthenium dioxide particles coated with the gold layer obtained in Example 12 had a low average value of 22.2 Ω.

[industrial use value]

According to the present invention, it is possible to provide a substrate having a coated metal layer having a stable conductivity, and to make the substrate of the coated metal layer low-cost, simple process, and environment for use without using special equipment or devices. The impact is minimally manufactured.

The substrate coated with the metal layer of the present invention can be used for a conductive material, an electromagnetic wave sealing material, or the like.

[Fig. 1] is a SEM photograph of the cerium oxide particles forming the gold nanoparticle layer obtained in Example 1.

[Fig. 2] is a SEM photograph of the cerium oxide particles coated with the silver layer obtained in Example 1.

[Fig. 3] is a SEM photograph of the coated silver layer polyimine particles obtained in Example 2.

[Fig. 4] is a SEM photograph of the cerium oxide particles forming the gold nanoparticle layer obtained in Example 7.

[Fig. 5] A SEM photograph of the cerium oxide particles coated with the silver layer obtained in Example 8.

[Fig. 6] is a SEM photograph of the soda lime glass beads of the silver-coated layer obtained in Example 9.

[Fig. 7] is a SEM photograph of the cerium oxide particles forming the gold nanoparticle layer obtained in Example 10.

[Fig. 8] is a SEM photograph of the cerium oxide particles forming the silver nanoparticle layer obtained in Example 11.

[Fig. 9] is a SEM photograph of the coated metal cerium oxide particles obtained in Example 12.

Claims (7)

A substrate coated with a metal layer, characterized by comprising a substrate, a dispersion or layer of metal nanoparticles formed on the substrate via a decane coupling agent containing a chelating forming functional group, and a metal layer formed on the dispersion or layer of the metal nanoparticle, wherein the substrate is made of cerium oxide, and the metal nanoparticle is made of gold having a particle diameter of 100 nm or less, and the metal layer is composed of The layer made of silver. The base material of the coated metal layer according to claim 1, wherein the shape of the base material is one selected from the group consisting of a spherical shape, a rod shape, a plate shape, a needle shape, a hollow shape, and a non-specific shape. The substrate of the coated metal layer according to claim 2, wherein the shape of the substrate is a fine particle shape having an average particle diameter of 0.1 to 100 μm. The substrate of the metal-clad layer according to any one of claims 1 to 3, wherein the chelating-forming functional group is an atom having at least one selected from the group consisting of a nitrogen atom, a sulfur atom and an oxygen atom. Functional group. The substrate of the coated metal layer according to claim 4, wherein the chelating-forming functional group is at least one selected from the group consisting of -SH, -CN, -NH ₂ , -SO ₂ OH, -SOOH, -OPO ( OH) Functional groups in groups of ₂ and -COOH. A method for producing a substrate coated with a metal layer, which is a method for producing a substrate for coating a metal layer according to any one of claims 1 to 5, characterized in that the substrate is contacted with a hydrolysis catalyst, and a chelate is provided. After forming a water-soluble solution of a decane coupling agent and a metal nanoparticle-forming metal salt of a forming functional group, it is formed by chelating on a substrate by treatment with a reducing agent. A functional decane coupling agent to form a dispersion or layer of metal nanoparticles, and then a metal layer is formed on the dispersion or layer of the metal nanoparticles. The method for producing a substrate coated with a metal layer according to claim 6, wherein the metal layer is formed by electroless plating.