JP3436327B2 - Conductive electroless plating powder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroless plating powder capable of imparting excellent dispersibility and high conductivity when blended in various matrix materials. In particular, the present invention relates to a conductive electroless plating powder suitable for the purpose of electrically connecting minute parts of electronic devices by being composited with a plastic material. [0002] Plastic materials provided with conductivity are:
It is widely used as a member for preventing static electricity, absorbing radio waves or shielding electromagnetic waves of electronic devices and components thereof. As a method for imparting conductivity to plastic materials, means for dispersing and complexing a fine powdered conductive filler in a matrix resin component has been conventionally used as a main technique, and an electroless plating powder is used as a conductive filler. It is also known (Japanese Unexamined Patent Publication Nos. 59-188291, 60-181294, and
-242782 gazette). In addition, a conductive filler in which a base material is plated with a metal using a benzoguanamine-based resin (Japanese Patent Laid-Open No.
-49632) and a conductive filler obtained by plating a metal with a styrenic resin as a base material (Japanese Patent Laid-Open No. 60-12603).
Etc. have also been proposed. However, in the conductive plating powder obtained by the conventional technique, the base particles agglomerate during the electroless plating step, and as the thickness of the metal plating layer increases, the agglomeration becomes large and strong, and the dispersibility is impaired. There are difficulties. Since the dispersibility of the conductive powder has a significant effect on the conductive performance when mixed with plastic materials, plating powder should expect reproducible high conductive performance as long as this dispersive phenomenon is not eliminated. Can not. [0004] Recently, a minute part of electronic equipment such as a connection between an electrode of a liquid crystal display panel and a circuit board of a driving LSI chip and a connection between electrode terminals of a fine pitch have been developed. Plastic materials with conductivity added to conductive materials for electrical connection are used, but for these purposes, particularly high and reproducible conductive performance is required, and more dispersibility is required. Development of improved conductive fillers is awaited. Since it is effective to adjust the particle size range in order to enhance the dispersibility of the electroless electroless plating powder, it has been practiced to adjust the particle size to a certain level by sieving or grinding. However, it is difficult to completely remove the agglomerates generated in the manufacturing process even if a high-precision classification treatment is performed, and if the pulverization treatment is performed, the metal coating on the particle surface is destroyed, and the conductive performance is reduced. . Therefore, in order to obtain an electroless plating powder exhibiting excellent conductive performance, it is necessary to ensure good dispersibility and adhesion by examining the particle properties of the resin powder as a plating base material. The inventors of the present invention have conducted various studies on the particle properties of the resin powder serving as the plating base material from this viewpoint. As a result, a resin having a substantially spherical shape and a specific range of particle properties was used as the base material. If selected, and this surface is coated with metal by electroless plating, a plating film with excellent adhesion will be formed, and the dispersibility of the target matrix component will be effectively improved, and a high level of conductive performance will always be obtained. Clarified the facts to be granted. [0007] The present invention has been developed based on the above-mentioned findings, and it is an object of the present invention to provide a high-quality conductive material capable of always providing excellent dispersibility and high conductive performance to a matrix component. An object of the present invention is to provide an electroless plating powder. The electroless electroless plating powder according to the present invention for achieving the above object is substantially spherical particles, and has an average particle diameter of 1 to 30 μm. In the above, the particle ratio in the range of the average particle diameter of ± 20% occupies 90 % or more, and the particle ratio of the fine side of the particles out of the range of the average particle diameter ± 20% is 1 % or less. Ben prepared
Zoguanamine-based resin powder is used as a base material, and the surface of the base material is touched.
The configuration is characterized in that a metal film having a thickness of 10 to 200 nm is formed by an electroless plating method including a step of complexing the base material particles subjected to the solvation treatment . In the present invention, there is no particular restriction on the type of resin used as the electroless plating substrate. Examples of usable resins include polyolefins such as polyethylene, polyvinyl chloride, polypropylene, polystyrene and polyisobutylene, olefin copolymers such as styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene terpolymer, polyacrylate, polymethyl methacrylate, and polyolefin. Acrylic acid derivative such as acrylamide, polyvinyl acetate, polyvinyl compound such as polyvinyl alcohol, polyacetal, polyethylene glycol, polypropylene glycol, ether polymer such as epoxy resin, benzoguanamine, urea, thiourea, melamine, acetoguanamine, dicyanamide, aniline, etc. Amino compounds and like formaldehyde, paraformaldehyde, acetaldehyde, glyoxal Amino resin consisting of aldehyde, polyurethane, polyester, fluorine-containing resin, and nitrile resin. However, among these, a benzoguanamine resin such as a benzoguanamine-formaldehyde resin or a benzoguanamine-melamine-formaldehyde resin, or a styrene resin represented by a polystyrene resin is preferably used. Of these, benzoguanamine resins are disclosed in JP-B-46-9420, JP-B-52-27679, JP-A-52-16594 or JP-A-52-16594.
It can be produced by the method disclosed in JP-A-51493. Specifically, benzoguanamine or a mixture of benzoguanamine and melamine is added to, for example, formalin to adjust the pH to 5 to 10,
The reaction is carried out at a temperature of ~ 100 ° C until the reaction product becomes hydrophobic, and after the reaction is completed, an appropriate protective colloid solution is added under stirring at a ratio of 1 to 30 parts by weight to 100 parts by weight of the reaction product to emulsify. And then 50 to 10 in the presence of a polymerization catalyst.
Fine and substantially spherical particles can be obtained by a method of polymerizing and curing in an emulsified state at a temperature of 0 ° C. On the other hand, the styrene resin is a polymer mainly composed of styrene, but may be a crosslinked polymer obtained by copolymerizing styrene with a small amount of a polyfunctional monomer. As monomers copolymerizable with styrene, acrylic acid esters,
Examples include methacrylic acid esters, unsaturated carboxylic acids, acrylonitrile, and butadiene. The polyfunctional monomer that forms a crosslinked polymer by copolymerization is, for example, divinylbenzene, a di- or tri (meth) acrylate of a polyhydric alcohol, or the like. By stirring the mixture containing these monomers, the radical polymerization initiator and the suspension stabilizer under heating, a fine and substantially spherical styrene resin powder can be obtained. As the resin substrate, a powder having a substantially spherical particle shape is used. The term “substantially spherical” means that in addition to a perfect spherical shape, a shape close to a spherical shape such as an elliptical shape is included.
Powders exhibiting a spherical morphology in the range of 1.0 are of interest. The Wardel sphericity is an index obtained by measuring the sphericity of a particle by (diameter of a circle equal to the projected area of the particle) / (diameter of the smallest circle circumscribing the projected image of the particle).
Indicates that the particle is closer to a sphere as it approaches. If the sphericity is less than 0.5, the shape of the powder often exhibits sharp protruding pieces, which causes the adhesion of the plating film to be impaired or the dispersibility to be reduced. The particle properties of the resin base material are such that the average particle diameter is in the range of 1 to 30 μm, the average particle diameter is within ± 20%, the particle volume ratio occupies 70% or more, and the average particle diameter is ± 30%.
Of the particles out of the 20% range, those having a particle volume ratio on the fine side of 10% or less are selectively used. The reason for limiting the average particle diameter to the range of 1 to 30 μm is that it is substantially difficult to obtain ultrafine particles having an average particle diameter of less than 1 μm, and if it exceeds 30 μm, the specific surface area decreases. This is because the conductive performance is reduced. A more preferable range of the average particle size is 5 to 10 μm.
If the particle volume ratio in the particle diameter range of ± 20% with respect to the average particle diameter is less than 70%, the particle size distribution becomes broad, impairs uniform dispersibility, and the particle diameter out of the average particle diameter ± 20% range. When the particle volume ratio on the fine side exceeds 10%, the number of fine particles increases and aggregation in the electroless plating step easily occurs, and as a result, factors that lower the adhesion and dispersibility of the plating layer are considered. Become. More preferred particle size distribution is such that the particle volume ratio in the average particle diameter ± 20% range is 90% or more, and the particle volume ratio on the fine side is 1% or less among the particles outside the average particle diameter ± 20% range. is there. A metal film is formed on the surface of the resin substrate having the above-mentioned particle properties by electroless plating. The metal to be coated is a conductive metal capable of performing an electroless plating operation, for example, Au, Ag, Co, Cu, Ni, Pd, Pt, and Sn.
And the like, and these metals may be alloys,
Two or more multi-layer coatings may be used. However, for the purposes of the present invention, it is preferred that the metal coating is a Ni coating or a Ni-Au multilayer coating. The Ni coating can firmly adhere to the base resin particles to form an electroless plating layer having good peeling resistance, and when an Au multilayer is formed on the upper surface thereof, the Ni coating can be used as an upper plating coating layer. Has the advantage of effectively functioning as an intermediate layer that secures strong bonding properties. Also,
When the Ni—Au multilayer film is used, the conductive performance can be further improved as compared with a single film. The preferred thickness of the electroless plating layer to be formed is 10 to 200 nm for a single-layer film,
In the case of a multilayer coating, the thickness is in the range of 10 to 300 nm, but is not limited thereto. The conductive electroless plating powder according to the present invention comprises:
A base material is a resin powder having specific particle properties in a substantially spherical form, and after capturing palladium ions on the surface of the base material, a catalytic treatment step of reducing this and supporting palladium on the base material surface, An electroless plating step of adding a complexing agent to the aqueous slurry of the catalyzed substrate and dispersing it sufficiently, and then separately adding at least two metal electroless plating solutions to form a metal film. It can be manufactured by applying. Further, in order to form a multi-layer coating, a method in which another metal electroless plating is performed on the substrate on which the metal coating is formed in the above-described step, and another metal coating is coated on the upper surface of the initial metal plating layer. Has been adopted. The specific means of the electroless plating method is performed as follows. First, a modification treatment for imparting a catalyst capturing ability to the surface of the base resin particles serving as the base is performed. What is catalyst capture ability?
In the catalyzing treatment step, the surface of the substrate has a function of capturing palladium ions as a chelate or a salt, and the modification is performed by the method described in JP-A-61-64882, that is, an amino-substituted organosilane-based coupling agent or the like. It can be performed using an epoxy resin that is cured by an amine curing agent. In the catalyzing treatment step, the substrate provided with the catalyst-capturing ability by the reforming is sufficiently dispersed in a dilute acidic aqueous solution of palladium chloride to capture palladium ions on the surface, and then the captured palladium ions. Is carried out by a reduction treatment so that palladium is supported on the surfaces of the base particles. At this time, the concentration of the aqueous palladium chloride solution was 0.05
To 1 g / l, with sodium hypophosphite, sodium borohydride, potassium borohydride,
Dimethylamine borane, hydrazine or formalin is used. The amount of the reducing agent to be added varies depending on the particle size of the base material, but is preferably in the range of 0.01 to 10 g / lg / l with respect to the aqueous solution. In the electroless plating step, as a first step, the base particles subjected to the catalyzing treatment are dispersed sufficiently uniformly in water, and an aqueous slurry having a dispersion concentration of 2 to 500 g / l, preferably 5 to 300 g / l. Is prepared. The dispersing operation can be usually performed by stirring, high-speed stirring, or a shearing dispersing device such as a colloid mill or a homogenizer. Next, a complexing agent is added to the aqueous slurry to sufficiently disperse it. Examples of complexing agents include carboxylic acids (salts) such as citric acid, hydroxyacetic acid, tartaric acid, malic acid, lactic acid, gluconic acid or alkali metal salts and ammonium salts thereof, amino acids such as glycine, and amines such as ethylenediamine and alkylamine. At least one compound having a complexing effect on metal ions, such as an acid, other ammonium, EDTA, and pyrophosphate (salt) is used. The complexing agent is usually added in the form of an aqueous solution, and its concentration is set in the range of 1 to 100 g / l, preferably 5 to 50 g / l. The preferred pH of the aqueous slurry at this stage is in the range of 4-14. The aqueous slurry thus prepared is
The electroless plating reaction is performed by separately and simultaneously adding at least two aqueous solutions of a metal salt, sodium hypophosphite, and sodium hydroxide as the electroless plating solution, respectively. The plating reaction starts immediately when the electroless plating solution is added to the aqueous slurry, but the metal film formed can be controlled to a desired film thickness by adjusting the addition amount. After the completion of the addition of the electroless plating solution, the generation of hydrogen gas is completely stopped, and the stirring is continued while maintaining the solution temperature for a while to complete the reaction. Although the metal film is formed as a dense and continuous thin film by the above-described steps, a multi-layer film having more excellent conductivity can be formed by further performing another metal plating treatment on the surface. For example, in the formation of an Au film, a heating agent and an electroless plating solution in which the pH is adjusted to a weakly acidic region with a complexing agent such as EDTA-4Na and citric acid-2Na and potassium hydroxide cyanide with an aqueous solution of sodium hydroxide are used. After adding the plating powder with stirring to form a dispersion suspension, potassium potassium cyanide, EDTA-4Na
And a mixed aqueous solution of citric acid-2Na and a mixed aqueous solution of potassium borohydride and sodium hydroxide are separately added to perform a plating reaction. Hereinafter, the product is similarly recovered by post-processing by a conventional method. The conductive electroless plating powder coated with metal by the electroless plating method in this manner has a coated metal layer formed as a dense and continuous thin film. The particle size is slightly larger than that of the resin particles, and does not substantially change the particle size distribution or the like. According to the present invention, the resin powder serving as a base material for electroless plating of a conductive metal has a substantially spherical particle form, an average particle diameter in the range of 1 to 30 μm, and an average particle diameter of 1 to 30 μm. Particles having a particle volume ratio in the range of diameter ± 20% occupying 70% or more and having a particle property in which the particle volume ratio on the fine side is 10% or less among the particles outside the average particle diameter ± 20% range. There is a key feature in the selection and use. Among them, the substantially spherical particle form has excellent fluidity, and effectively functions to prevent a phenomenon in which individual particles agglomerate and to form a uniform plating layer. The average particle diameter in the range of 1 to 30 μm contributes to enhancing the conductive performance when the electroless plating powder is dispersed and composited in a matrix as fine particles having a large specific surface area. The particle volume ratio in the range of the average particle diameter of ± 20% occupies 70% or more, and the particle volume ratio on the fine side of the particles out of the range of the average particle diameter ± 20% is 10% or less. It has a particle distribution with a sharp distribution and a relatively small amount of fine particles that promote agglomeration, and has an effect of increasing the adhesion of the electroless plated metal and at the same time remarkably improving the dispersibility of the plating powder. Together with such actions, it is possible to provide an electroless plating powder that can always be blended with a matrix material with good dispersibility and that can impart high conductivity. EXAMPLES Examples of the present invention will be specifically described below in comparison with comparative examples. Examples 1 to 5 and Comparative Examples 1 to 4 (1) Base resin powder; a substantially spherical powder having a Wardel sphericity of 0.5 or more as a base, as shown in Table 1. A benzoguanamine-formaldehyde resin (BA), a benzoguanamine-melamine-formaldehyde resin (BMA) and a polystyrene resin (PS) having particle properties were used. [Table 1] [Table Note] BA: benzoguanamine / formaldehyde resin, BMA: benzoguanamine / melamine / formaldehyde resin, PS: polystyrene resin. (2) Ni electroless plating treatment: 10 g of each base resin powder shown in Table 1 was added to a conditioner liquid [manufactured by Shipley, "Cleaner Conditioner 231"] at 40 ml / l.
The solution was added to 200 ml of an aqueous solution with stirring, and then the surface was modified by stirring for 5 minutes. The aqueous solution was filtered, and the base resin powder washed once with reparable water was immersed in 200 ml of a 1 g / l stannous chloride aqueous solution at room temperature for 5 minutes, filtered, washed, and sensitized. Then, the mixture was charged with stirring into 200 ml of a catalyzed liquid comprising a 0.1 ml / l aqueous solution of palladium chloride and 0.1 ml / l of hydrochloric acid, followed by stirring for 5 minutes to capture palladium ions. The aqueous solution was filtered, and the substrate powder washed once with water was immersed in a 1 g / l aqueous solution of sodium hypophosphite at room temperature for 5 minutes to perform a reduction treatment, whereby palladium was supported on the surface of the substrate. The base was heated to a temperature of 65 ° C. and added to each of the complexing agent aqueous solutions shown in Table 2 with stirring, and sufficiently stirred and dispersed to prepare an aqueous slurry. Then, the Ni electroless plating solution shown in Table 3 was prepared. 80 ml of each of the liquid a and the liquid b was added simultaneously with stirring at an addition rate of 5 ml / min. [Table 2] [Table 3] After the total amount of the Ni electroless plating solution was added, stirring was continued while maintaining the temperature at 65 ° C. until the bubbling of hydrogen stopped. Then, the plating solution was filtered, and the filtrate was washed three times in a re-pulverized manner, and then dried at 100 ° C. with a vacuum drier to obtain a powder having a Ni film. All the filtrates after the plating reaction were colorless and transparent, and it was confirmed that the provided plating solution was completely consumed in the plating reaction. When the obtained Ni electroless plated particles were observed with an electron microscope,
Independent particles having almost no agglomerated particles, all substantially spherical particles exhibiting a uniform and smooth coating layer of fine Ni metal particles, and the plating film is formed as a dense and continuous film. It was confirmed that. (3) Au electroless plating treatment: 10.0 g of the Ni electroless plating particles obtained in
-4Na (10 g / l), citric acid-2Na (10 g / l) and potassium gold cyanide (3.0 g / l, 2.1 g / l as Au), adjusted to pH 6 with aqueous sodium hydroxide solution It was added to an electroless plating solution (solution A) at 60 ° C. while stirring, and subjected to Au plating for 10 minutes. Then, potassium potassium cyanide (10 g / l, 6.8 g / l as Au), EDT
A-4Na (10 g / l) and citric acid-2Na (10 g / l) mixed aqueous solution (solution B) and potassium borohydride (30 g / l)
Then, a mixed aqueous solution (solution C) of sodium hydroxide (60 g / l) was added separately and simultaneously over 20 minutes through a liquid sending pump. At this time, the liquid A amount, the liquid B amount, and the liquid C amount were set to the ratios shown in Table 4. [Table 4] Subsequently, the solution was filtered, and the filtrate was washed three times with a rebuilt filter, dried at a temperature of 100 ° C. with a hot air drier, and subjected to an Au electroless plating coating process on the Ni film, and the Ni surface was coated with Ni. -A multilayer coating of Au was formed. FIG. 1 shows a second embodiment.
FIG. 2 is an electron micrograph (magnification: about 330 times) showing the particle structure of a conductive electroless plating powder (average particle size: 4.84 μm) formed by a multilayer coating of Ni—Au obtained by the method of FIG. 5 is an electron micrograph (magnification: about 330 times) showing the particle structure of a conductive electroless plating powder (average particle size: 9.8 μm) formed by a Ni—Au multilayer film obtained in Example 4. (3) Evaluation of physical properties; average particle size of conductive electroless plating powder obtained in this way, film thickness of Ni film after Ni electroless plating treatment, conductivity, dispersibility, and peeling resistance , Ni—Au multilayer coating film thickness and conductivity, dispersibility,
The peel resistance was measured and evaluated, and the results are shown in Tables 5 and 6. In addition, each physical property evaluation was performed by the following method. Measurement of average particle diameter of plating powder; measured by Coulter counter method and laser diffraction method. Calculation of plating film thickness: The plating film thickness was calculated by the following equation. Where r is the radius of the base particles (μm) and t is the plating film thickness (μm).
m), d ₁ is the specific gravity of the plating film, d ₂ is the specific gravity of the base particle. Conductivity measurement: A method of measuring the electric resistance between the upper and lower electrodes under a state in which 1.5 g of the plating powder was placed in a vertically-standing resin cylinder having an inner diameter of 10 mm and a load of 5 kg was applied. Measurement of dispersibility: 0.1 g of plating powder was added to 1
Place in a 00 ml beaker, add 50 ml of toluene, and treat with an ultrasonic cleaner (Honda Electronics Co., Ltd., 28 kHz, 100 W) for 1 minute while stirring with a microspatula. The treated slurry is taken out with a microspatula and spread on a slide glass to a diameter of 1 cm. The slide glass is set on a stage of a metal microscope (manufactured by Olympus, 500 times), and a state one minute after irradiation with transmitted light is photographed.
In the evaluation method, the number of agglomerated plating particles in a size of 5 times or more in the vertical and horizontal directions of the average particle diameter in a visual field of 20 photographs taken by the above method is measured, and the evaluation is determined based on the following criteria. 5 or less: ◎, 5 to 10: 、, 10 or more: × Adhesion measurement: 2.2 g of plating powder and 90 g of zirconia beads were placed in a 100 ml mayonnaise bottle, and 10 ml of toluene was added with a whole pipette. . Stir at 400 rpm for 10 minutes with a stirrer (three one motor). After completion, aspirate the sample solution with a pipette,
Spread on a slide to a diameter of about 1 cm. After the toluene evaporates, add a drop of the dispersant and spread it evenly with a spatula. Observation with a metallurgical microscope, 5 field transmission photography (50
0), and observe the field of view where the plating layer is most severely peeled off, and evaluate from the number of peelings according to the following criteria. 2 or less: ◎, 2 to 10: 、, 10 or more: × Comparative Example 5 The electroless plating powder prepared in Comparative Example 1 was substantially mixed with the base particles in a ball mill containing alumina balls. Dry pulverization was performed until an equivalent particle distribution was obtained, and the properties of the powder were measured and evaluated. [Table 5] [Table 6] From the results shown in Tables 5 and 6, the electroless electroless plating powders of the examples are more excellent in conductivity, dispersibility and adhesion than the comparative examples which do not satisfy the requirements of the present invention. Is remarkably improved. Example 6 (1) Ag electroless plating treatment: The same benzoguanamine / formaldehyde resin powder as used in Example 1 shown in Table 1 was used as a base material, and 10 g of this resin powder was used as a conditioner solution [manufactured by Shipley, "Cleaner Conditioner". 231 "] 4
The solution was added to 200 ml of a 0 ml / l aqueous solution with stirring, followed by stirring for 5 minutes for surface modification. The aqueous solution was filtered, and the substrate powder washed once with repulped water was immersed in 200 ml of a 1 g / l aqueous solution of stannous chloride at room temperature for 5 minutes, filtered, washed and sensitized. Next, a catalyzed liquid 200 consisting of 0.1 ml / l aqueous palladium chloride and 0.1 ml / l hydrochloric acid was used.
Then, the mixture was charged into the ml with stirring, and subsequently stirred for 5 minutes to capture palladium ions. The aqueous solution was filtered, and the substrate powder washed once with reparable water was immersed in a 1 g / l aqueous solution of sodium hypophosphite at room temperature for 5 minutes to perform a reduction treatment, whereby palladium was carried on the surface of the substrate. Next, a solution containing 4 g / l each of sodium hydroxide and sodium cyanide was added to 8
Dispersed in a solution heated to 0 ° C., and in the same manner as in Example 1, the Ag electroless plating solution shown in Table 7 was divided into solution a and solution b, and 80 ml of each was stirred at an addition rate of 5 ml / min. Added at the same time. [Table 7] After the total amount of the Ag electroless plating solution was added, stirring was continued while maintaining the temperature at 65 ° C. until hydrogen bubbling stopped. Then, the plating solution was filtered, and the filtrate was washed three times by repulping, and dried at 100 ° C. with a vacuum dryer to obtain a powder having an Ag film. All the filtrates after the plating reaction were colorless and transparent, and it was confirmed that the provided plating solution was completely consumed in the plating reaction. Ag obtained
Observation of the electroless plated particles with an electron microscope shows that each of the particles is a spherical particle exhibiting a uniform and smooth coating layer of fine Ag metal particles, and the plating film is formed as a dense and substantially continuous film. Was confirmed. (2) Au electroless plating treatment: The Ag electroless silver plating powder obtained in the above step (1) was subjected to electroless Au plating treatment in the same manner as in Example 1. The thus obtained conductive electroless plating powder having the Ag-Au multilayer coating was evaluated for various physical properties in the same manner as in Example 1, and the results are shown in Table 8. Example 7 A conductive electroless plating powder having an Ag-Au multilayer coating was obtained by the same operation as in Example 6 except that the base resin powder was changed to the same benzoguanamine / formaldehyde resin as in Example 2. Produced. Various properties of this conductive electroless plating powder were evaluated in the same manner as in Example 1, and the results are shown in Table 8. Comparative Example 6 As a substrate, an average particle diameter was 9.6 μm, and an average particle diameter was ± 20.
% Particle volume ratio in the range of 44.7%, average particle diameter ± 20
% Of the fine particles out of the% range is 2
Using 5.6% of a substantially spherical benzoguanamine / melamine / formaldehyde resin powder, a conductive electroless plating powder having an Ag-Au multilayer coating was produced in the same manner as in Example 6. Various properties of this conductive electroless plating powder were evaluated in the same manner as in Example 1, and the results are shown in Table 8. [Table 8] As described above, according to the present invention, an electroless metal plating layer is formed on the surface by using a particulate resin powder of a specific range which is substantially spherical and has a sharp particle size distribution as a substrate. By coating, it becomes possible to provide a conductive electroless plating powder in which a dense and continuous plating layer is adhered with good adhesion and which has excellent dispersibility in a composite matrix material. Therefore, it is extremely useful for applications requiring high conductive performance, such as precision conductive materials for liquid crystal display panels.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an electron micrograph showing the particle structure of a conductive electroless plating powder (average particle size: 4.84 μm) with a Ni—Au multilayer coating obtained in Example 2. (Magnification: about 330 times). FIG. 2 is an electron micrograph (magnification: about 330 times) showing the particle structure of a conductive electroless plated powder (average particle size: 9.8 μm) obtained by a multilayer coating of Ni—Au obtained in Comparative Example 4. It is.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-33808 (JP, A) JP-A-7-118866 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 18/16 C08J 3/12 C23C 18/31 H01B 1/00

Claims (1)

(57) [Claims 1] Substantially spherical particles having an average particle diameter in a range of 1 to 30 µm, and a particle volume ratio in an average particle diameter ± 20% range of 90%. Occupy the above and average particle diameter ±
Substrate particles obtained by subjecting a benzoguanamine-based resin powder having a particle property of having a particle volume ratio on the fine side of 1% or less to a base material to the base material surface and subjecting the surface of the base material to catalysis treatment, out of the 20% range By the electroless plating method including the step of complexing
A conductive electroless plating powder comprising a metal film having a thickness of 10 to 200 nm .