JP3168761B2 - Manufacturing method of metal coated powder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a resin base material suitable for use as an electromagnetic shield material, a radio wave absorber, a heating element, various resin fillers, conductive paints, conductive inks, coloring agents, and the like. And a method for producing a metal-coated powder comprising:

[0002]

2. Description of the Related Art Conventionally, methods for producing a metal-coated powder obtained by coating a metal on a resin powder include an electroless plating method, a sputtering method, and an electroplating method.

[0003]

Although the electroless plating method is excellent in metal covering property due to its characteristics, as a pretreatment for plating, treatments such as hydrophilization by etching and the like, porosification treatment, and catalyst application are performed. This is necessary, the process becomes complicated, and depending on the resin material, the treatment may not be performed in some cases. In addition, the sputtering method has problems that the apparatus is expensive, the processing time is long, and the resin is limited to a resin having high heat resistance. Furthermore, although the electroplating method can be applied to the case where the size of the resin powder is large, it cannot be applied to fine particles, and the plating pretreatment is required as in the case of the electroless plating. There were problems such as becoming.

[0004] Among these prior arts, particularly, a method of coating a resin powder with a metal by an electroless plating method has a problem of uniformity of metal.
It is an excellent method because it is easy to control the metal thickness etc., but since the electroless plating solution has a high self-decomposition property, the etching solution in the hydrophilic treatment in the pretreatment of the resin is mixed into the plating solution, Alternatively, a colloid of a noble metal such as Pd is generally supported as a catalyst in order to cause an initial precipitation reaction of the plating.
There is a problem that the dissolution induces decomposition of the plating solution.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a metal coating method for a resin powder which does not require an etching treatment for hydrophilizing the surface of the resin powder and does not need to support a noble metal catalyst. The purpose is to adhere semiconductor particles on the resin powder, after fixing, after dispersing the powder in an aqueous solution containing at least a reducing agent and a metal salt,
The gist of the present invention is a method for producing a metal-coated powder obtained by irradiating ultraviolet rays to precipitate a metal outside semiconductor fine particles.

[0006] First, as a resin powder as a base material, natural fibers, natural resins, polyethylene, polystyrene, polyester, polypropylene, polyamide resins, polyacetal resins, polycarbonates, ABS, AS, styro-
Resin, vinyl chloride resin, polyacrylic acid resin, polyacrylonitrile, fluororesin, silicone resin, phenol
Resin, urea resin, urea resin, polyurethane resin, melamine resin, epoxy resin and the like.

The outer shape of these resin powders is spherical, fibrous, scaly, amorphous or the like, and the inner shape is various such as solid, hollow, or porous. It is possible. The size of these powders is preferably about 1 to 200 μm.

Next, TiO ₂ ,
WO ₃ , ZnO, SnO ₂ , V ₂ O ₅ , CdS, CdSe,
SrTiO ₃ , SiC, etc., and the particle size may be １ ／ or less of the particle size of the resin powder used. or,
As the shape of the semiconductor fine particles, various shapes such as a fibrous shape, a spherical shape, a scaly shape, and an amorphous shape can be used. Further, fine particles may be used alone, or two or more kinds may be mixed and used. By irradiating these semiconductor fine particles with ultraviolet rays,
It produces excited electrons and holes, which have high energy and are known to have strong oxidizing and reducing powers.

The method of attaching and fixing the semiconductor fine particles on the resin powder includes mortar, automatic mortar, ball mill, mechano mill (manufactured by Okada Seiko Co., Ltd.), mechano fusion system (manufactured by Hosokawa Micron Corporation), Hybridization system (Nara Machinery Co., Ltd.), Dispaco
(Nisshin Flour Milling Co., Ltd.), Coatmizer (Freund Co., Ltd.) or the like. In the case of a colloidal dispersion solution, a resin powder is dispersed in a colloidal solution, It may be prepared by adsorbing and adhering to the surface, taking out by filtration, drying and pulverizing.

Next, a solution containing a metal salt and a reducing agent will be described. Au, Ag, Pt, Pd, R
h, sulfates such as Cu, Ni, Co, and Sn, halides, nitrates, oxyacid salts, cyanide compounds, and aliphatic carboxylate salts. NaH ₂ PO ₂ , N
a ₂ HPO ₃ , KBH ₄ , NaBH ₄ , N ₂ H ₄ , hydrazine sulfate, dimethylamine borane, formaldehyde, glyoxal, glucose, tartaric acid and their sodium, potassium salts, citric acid and their sodium and potassium salts, Ferrous salts such as oxalic acid and ferrous chloride, Sn
Examples include stannous salts such as Cl ₂ , ferrocyanide hydroacid and their sodium and potassium salts, and H ₂ O ₂ .

The mixing ratio between the metal salt and the reducing agent may be 1 mol to a maximum of about 10 mol per 1 mol of the metal salt, and the concentration of the metal salt in the solution is 0.005 mol / l. ~ 2
It may be about mol / l. Further, for stabilizing the metal salt, various chelating agents, pH buffers, stabilizers and the like may be contained. In addition, as the aqueous solution containing the metal salt and the reducing agent, a commercially available electroless plating solution can also be used.

Ultraviolet rays for causing a metal deposition reaction may be irradiated with light having a wavelength of 10 nm to 400 nm, and may be a high-pressure mercury lamp, a xenon short arc lamp, an ultraviolet fluorescent lamp, a carbon arc lamp. , A metal halide lamp, a germicidal lamp, and the like.

The basic method for producing the metal-coated powder of the present invention is as described above. In addition to the above, for example, the method may be applied to the outside of the semiconductor fine particles adhered and fixed on the resin powder according to the purpose of use. After depositing and coating the metal, a coating of the same metal or another metal may be formed by a conventional electroless plating method, electroplating method, sputtering method, vacuum deposition method, or the like. May be performed.

[0014]

According to the present invention, semiconductor fine particles are deposited on a resin powder,
After fixing, the powder is dispersed in an aqueous solution containing at least a reducing agent and a metal salt, and then irradiated with ultraviolet light to deposit a metal on the outside of the semiconductor fine particles to obtain a metal-coated powder. In the case of obtaining a metal-coated powder by an electroless plating method, hydrophilic treatment by etching or the like and support of a catalyst such as Pd were necessary, but these treatments became unnecessary, and contamination of an aqueous solution containing a metal salt was required. Decomposition due to, for example, is eliminated, and a stable metal coating treatment becomes possible, and various resin powders can be treated.

[0015]

【Example】

Example 1 Nylon 12 powder (manufactured by Toray Industries, Inc., SP
-500, average particle diameter 5 μm), TiO ₂ (AK15, manufactured by Titanium Industry Co., Ltd.) as semiconductor fine particles, 100 parts of nylon 12 powder and 48 parts of TiO ₂ were mixed, and a hybridization system ( (Manufactured by Nara Machinery Co., Ltd.) using 8000 rpm for 5 minutes to adhere TiO ₂ on nylon 12 powder,
A fixed powder was obtained. Next, the nylon 12 powder to which TiO ₂ was attached and fixed was treated with copper sulfate 15 g / l, NaOH
8 g / l, Rossel salt 8 g / l, formaldehyde 37
% Aqueous solution 40 ml / l, pH1 containing 2 g / l of EDTA
The mixture was dispersed in the aqueous solution of No. 2 and irradiated with an ultraviolet lamp (manufactured by Oilrex Co., Ltd., Lab Cure) for 60 minutes while stirring at 30 ° C. to obtain a powder coated with copper.

Example 2 Silicon resin powder (Toray Silicon Co., Ltd., Trefil E-501, average particle diameter 5 μm) was used as the resin powder.
And ZnO (Sakai Chemical Co., Ltd.)
100 parts of the silicon resin powder and 50 parts of ZnO were mixed and treated in an automatic mortar for 4 hours to deposit ZnO on the silicon resin powder.
A fixed powder was obtained. Next, the silicon resin powder obtained by adhering fixing the ZnO, PDC1 ₂ 0.01 mol /
, 0.08 mol / l of ethylenediamine, 20 mg / l of thiodiglycolic acid and 0.06 mol / l of NaH ₂ PO ₂ , dispersed in an aqueous solution having a pH of 8 and stirred at 40 ° C. with a sterilizing lamp (Toshiba Lighting & Technology Corp.) ) Was irradiated for 30 minutes to obtain a powder coated with Pd.

Example 3 As the resin powder, polystyrene resin powder (fine par 3000 SP, manufactured by Sumitomo Chemical Co., Ltd., average particle diameter 6)
μm), using WO ₃ (manufactured by Nippon Tungsten Co., Ltd., average particle diameter 0.5 μm) as semiconductor fine particles, mixing 100 parts of polystyrene resin powder with 59 parts of WO ₃ ,
By treating with a hybridization system (manufactured by Nara Kikai Seisakusho Co., Ltd.) at a rotation speed of 8000 rpm for 5 minutes, a powder obtained by adhering and fixing WO ₃ on a polystyrene resin powder was obtained. Next, nickel chloride 30 g / l, N
aH ₂ PO ₂ 10 g / l, sodium hydroxyacetate 50
The polystyrene resin powder obtained by attaching and fixing WO ₃ to an aqueous solution having a pH of 6.3 containing g / l is dispersed, and irradiated with a UV lamp (manufactured by Oilrex Corp., Lab Cure) for 120 minutes. A coated powder was obtained.

Claims (1)

(57) [Claims] 1. After adhering and fixing semiconductor fine particles on a resin powder, dispersing the powder in an aqueous solution containing at least a reducing agent and a metal salt, and then irradiating with ultraviolet light to deposit a metal outside the semiconductor fine particles. A method for producing a metal-coated powder.