JP2002069663A - Forming method of metal coating film on surface of resin compact - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily forming a metal coating film superior in film thickness accuracy and surface smoothness and with high peel strength on a surface of a resin compact. SOLUTION: This method is characterized by accommodating the resin compact and a producing substance of metal fine powder in a treatment vessel, producing the metal fine powder from the above producing substance of metal fine powder by fluid contacting the above producing substance for metal fine powder to the surface of the resin compact in the treatment vessel, forming a metal layer consisting of the metal fine powder on the surface of the resin compact, and then forming the metal coating film on the above metal layer. (However, an R-Fe-B based bond magnet is excluded from the above resin compact).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a metal film on a surface of a resin molded product. More specifically,
In the processing container, a metal fine powder generating substance that generates metal fine powder is brought into fluid contact with the surface of the resin molded body,
The present invention relates to a method for forming a metal layer made of fine metal powder on the surface of a resin molded body, and then forming a metal coating on the metal layer.

[0002]

2. Description of the Related Art For the purpose of imparting various functions such as decorativeness, weather resistance, surface conductivity, electromagnetic wave shielding property and antibacterial property to a resin molded product, it has been conventionally performed to form a metal coating on the surface of the resin molded product. I have. As the method, for example, a vacuum plating method such as vacuum evaporation or sputtering, an electroless plating method, an electroless / electroplating method of performing an electroplating process after the electroless plating process, and the like are known. These methods have been put to practical use in various fields since the resin molded body is non-conductive and cannot be directly electroplated. However, in the vacuum plating method, the peel strength of the obtained metal film is low, the durability is inferior, the application to a molded article having a complicated shape is difficult, and gas is generated depending on the type of resin. Therefore, there are problems that time is required during vacuum processing and that production costs are high. In the electroless plating treatment method, usually, in performing the treatment, it is necessary to perform an etching treatment on the surface of the resin molded body in advance, or to perform a catalyst application treatment such as a sensitizing → activation method, so that the process is complicated. However, there are problems such as the fact that it takes a long time to process, and the obtained plating thickness is thin. In the electroless / electroplating method, the peel strength of the obtained metal film is relatively good, and the durability is considerably better than that of the vacuum plating method, but the process becomes complicated and the process requires time. It has problems such as that. In addition, a method of applying a resin to which a metal powder is added to the surface of the resin molded body to impart conductivity and then performing an electroplating process has been proposed, but a resin layer is uniformly provided on the surface of the resin molded body. In general, it is difficult to form a metal film having excellent film thickness accuracy and surface smoothness due to the non-uniformity.

[0003]

In view of such circumstances, the present invention provides a method for easily forming a metal film having excellent film thickness accuracy and surface smoothness and high peel strength on the surface of a resin molded product. The purpose is to do.

[0004]

Means for Solving the Problems The present inventors have conducted various studies in order to solve the above-mentioned problems, and as a result, in the processing vessel, the metal fine powder-generating substance was caused to flow to the surface of the resin molded body. It has been found that upon contact, metal fine powder is generated from the metal fine powder generating substance, and the generated metal fine powder forms a strong and high-density metal layer on the surface of the resin molded product. Furthermore, since the metal layer thus formed functions as a conductive layer, it has been found that a metal coating can be easily formed on the surface of the resin molded article by performing electroplating in a subsequent step.

The present invention has been made on the basis of such knowledge. The method of forming a metal film on the surface of a resin molded product according to the present invention comprises treating a resin molded product and a metal fine powder-generating substance. In a processing container, the metal fine powder-generating substance is brought into fluid contact with the surface of the resin molded body in the processing container to generate metal fine powder from the metal fine powder-generating substance. Forming a metal layer made of the metal fine powder on the metal layer, and then forming a metal coating on the metal layer (however, R-
Fe-B based bonded magnets are excluded). According to a second aspect of the present invention, in the forming method of the first aspect, a vibration is applied to the resin molded body and the metal fine powder generating material, and / or the both are agitated, so that the surface of the resin molded body is agitated. And causing the metal fine-powder-producing substance to come into fluid contact. According to a third aspect of the present invention, in the method of the first or second aspect, the processing container is a processing tank of a barrel device. In a fourth aspect of the present invention, there is provided a method as set forth in any one of the first to third aspects, wherein a dry treatment is performed. Further, the forming method according to claim 5 is a method according to claims 1 to 4.
In the forming method according to any one of the above, the metal fine powder generating substance is Cu, Sn, Zn, Pb, Cd, In, Au,
It is a substance that generates fine powder of at least one metal selected from Ag, Fe, Ni, Co, Cr, and Al. According to a sixth aspect of the present invention, in the method of any one of the first to fifth aspects, the surface of the resin molded body is roughened in advance as a pre-process. According to a seventh aspect of the present invention, in the method of any one of the first to sixth aspects, the metal film is formed by electroplating or electroless plating. Further, the resin molded article of the present invention is characterized in that a metal coating is formed on a metal layer made of metal fine powder formed on the surface of the resin molded article as described in claim 8 (however, the resin R-Fe
-B-based bonded magnets are excluded).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION According to the method for forming a metal film on a resin molded product of the present invention, a resin molded product and a metal fine powder generating substance are accommodated in a processing container, and the surface of the resin molded product is treated in the processing container. Then, the metal fine powder generating substance is brought into fluid contact with the metal fine powder from the metal fine powder generating substance to form a metal layer made of the metal fine powder on the surface of the resin molded body. It is characterized in that a metal coating is formed (however, R-Fe-B-based bonded magnets are excluded from the resin molded body). Therefore, the shape of the resin molded body is not particularly limited as long as the metal fine powder generating substance is in fluid contact with the surface thereof.

The present invention is a method for forming a metal film on the surface of a resin molded body. Therefore, the resin molded body of the present invention includes not only the molded body itself made of resin but also only the surface made of resin. What is configured, the inside of the molded body contains components other than resin, but the surface is substantially composed of resin (for example, the inside of the molded body is composed of magnetic powder and resin, Bonded magnets whose surface is substantially made of resin) are also included (however, R-Fe-B-based bonded magnets are excluded from the resin molded body).

The resin constituting the resin molded body includes epoxy resin, polyvinyl chloride resin, acrylic resin, silicone rubber, fluorine resin such as Teflon (registered trademark),
BS resin (acrylonitrile-butadiene-styrene copolymer resin), polyolefin resin such as polyethylene and polypropylene, phenol resin, polycarbonate,
Polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polyimide resin, FRP
(Fiber-reinforced plastics), polyamide resins such as nylon, and thermoplastic elastomers such as polyester elastomer.

[0009] Examples of the metal fine powder generating material serving as a metal fine powder generating source include Cu, Sn, Zn, Pb, Cd, and I.
Substances that generate fine powder of at least one metal selected from n, Au, Ag, Fe, Ni, Co, Cr, and Al. Further, the metal fine powder generating substance may be a substance made of an alloy containing the above-mentioned metal component. Note that a plurality of metal fine powder generating substances may be used in combination so that a metal layer made of a desired alloy fine powder derived from the plurality of metal fine powder generating substances is formed on the surface of the resin molded body (for example, By using a Pb fine powder generating substance and a Sn fine powder generating substance in combination, Pb
A metal layer composed of Sn alloy fine powder can be formed, which can be used as an electric contact member such as an IC). Further, the metal fine-powder-producing substance may contain impurities that are inevitable in industrial production.

[0010] The metal fine-powder-producing substances include various kinds such as needle-like (wire-like), column-like, and lump-like pieces such as a metal piece composed of only a desired metal, a composite metal piece obtained by coating a core material composed of different metals with a desired metal. Although any shape can be used, from the viewpoint of efficiently generating metal fine powder, it is desirable to use a needle-like or column-like shape having a sharp end.
Such a desirable shape can be easily obtained by employing a known wire cutting technique.

[0011] The size (major axis) of the metal fine powder-producing substance is set at 0.1 from the viewpoint of efficiently generating metal fine powder.
It is preferably from 0.05 mm to 10 mm, more preferably from 0.
3 mm to 5 mm, more preferably 0.5 mm to
3 mm. The metal fine-powder-producing substances may have the same shape and the same size, or may have different shapes and the same size.

[0012] The method of fluidly contacting the metal fine powder-generating substance with the surface of the resin molded product is to efficiently generate metal fine powder from the metal fine powder-generating substance, and to efficiently form a metal layer using the generated metal fine powder. From
Applying vibration to the resin molded body and the metal fine powder generating substance, and / or
Alternatively, a method of stirring both is desirable. Such a method
For example, it can be performed using a processing tank of a barrel device or a ball mill device. For example, as the barrel device, a known device such as a rotary type, a vibration type, or a centrifugal type can be used. In the case of a rotary type, the rotation speed is 20 rpm to 5
It is desirable to set it to 0 rpm. In the case of the vibration type, the frequency is 50 Hz to 100 Hz, and the vibration amplitude is 0.3 mm to
It is desirable to set it to 10 mm. In the case of the centrifugal type, it is desirable that the rotation speed be 70 rpm to 200 rpm.

[0013] The amount of the resin molded product and the metal fine powder forming substance to be charged into the processing container is 20 vol% to 90% of the volume of the processing container.
vol% is desirable. If it is less than 20 vol%, the amount of treatment is too small to be practical, and if it exceeds 90 vol%, the metal layer may not be efficiently formed on the surface of the resin molded product. Further, the ratio of the resin molded body and the metal fine powder generating substance charged into the container is desirably 3 or less in terms of volume ratio (resin molded body / metal fine powder generating substance).
If the volume ratio exceeds 3, it takes a long time to form the metal layer, which may not be practical.

Although the processing time depends on the amount of processing, it is generally about 1 hour to about 10 hours.

It is desirable that the metal fine powder-generating substance be brought into fluid contact with the surface of the resin molding in a dry manner in consideration of the case where the metal fine powder-generating substance is easily oxidized and corroded.

The size (major axis) of the metal fine powder generated from the metal fine powder generating material by the flow contact of the metal fine powder generating material with the surface of the resin molded product is approximately 0.001 μm to 5 μm.
And its shape is various. The generated metal fines are
A portion of the surface of the resin molded body that collides with the contents (many of which are metal fine powder generating substances) in the processing container, whose tip is pierced and pressed into the surface of the resin molded body, and protrudes above the surface of the resin molded body. Deform (eg, spread) to cover its surface. This is a stepping stone for the formation of the metal layer. Thereafter, the metal fine powder laminated on the metal fine powder pressed into the surface of the resin molded product, the metal fine powder deformed from the metal fine powder, an aggregate of the metal fine powder, and a deformed product of the aggregate ( For example, the flakes are spread to form a scale), and a laminate of the aggregate contributes to the formation of the metal layer, and constitutes the metal layer as a whole.
Therefore, the metal layer made of metal fine powder in the present invention means a metal layer formed using metal fine powder generated from a metal fine powder generating substance as a forming source.

In the initial stage of forming the metal layer,
As an assisting means for the metal fine powder to be efficiently pressed into the surface of the resin molded body, the surface of the resin molded body may be previously roughened with emery abrasive paper or the like in the preceding step.

The metal layer formed of the metal fine powder thus formed functions as a conductive layer, so that it is possible to perform an electroplating process, and the resin molded body has excellent film thickness accuracy and excellent surface smoothness. A metal coating can be formed. Further, since the metal layer is formed based on the metal fine powder pressed into the surface of the resin molded body, it has an anchoring effect on the surface of the resin molded body, and thus is formed on the metal layer. The metal coating has a feature of high peel strength.
Further, there is an advantage that electroless plating can be performed on the metal layer without performing an etching process, a catalyst application process, or the like.

[0019]

EXAMPLES Reference Example 1 The following treatment was performed using a 3 cm square block made of epoxy resin as a sample. First, the surface of the sample was polished with # 280 emery abrasive paper to roughen the surface. Next, 10 samples whose surface was roughened (apparent volume 0.27 liter) and a short columnar Cu 2 mm in diameter and 2 mm in length having an apparent volume of 2 liters
1. Volume of fine powder-generating substance (cut wire)
It is charged into the processing tank of an 8 liter vibrating barrel device (total charging amount is 81 vol% of the processing tank internal volume), and the vibration frequency is 60H.
The treatment was performed dry for 4 hours under the conditions of z and a vibration amplitude of 1.5 mm. The Cu fine powder generated by this operation is a fine powder having a long diameter of 0.1 μm or less and a long fine powder having a long diameter of 5 μm.
m. When the sample surface after the treatment was observed with an optical microscope (100 times), Cu was found on the entire surface.
It was found that the metal layer composed of fine powder was formed uniformly.

Example 1 A sample having a metal layer made of fine Cu powder on the entire surface obtained in Reference Example 1 was subjected to ultrasonic cleaning for 1 minute, and then subjected to electric Ni plating by a trapping plating method and a current density of 2 A / dm. ² , plating time 60 minutes, pH
4.2, bath temperature 55 ° C, plating solution composition (nickel sulfate 24
0 g / l, nickel chloride 45 g / l, appropriate amount of nickel carbonate (pH adjustment), boric acid 30 g / l) to form a plating film having a thickness of 15 μm on a metal layer composed of Cu fine powder. Was completed.

Reference Example 2 The following treatment was performed using a 3 cm square block made of epoxy resin as a sample.
Treatment of 10 samples (apparent volume 0.27 liters) and 2 liters apparent volume 1 mm diameter, 1 mm long short columnar Al fine powder producing material (cut wire) in a 2.8 liter volume vibration barrel device Into the tank (total charge is 81 vol% of the inner volume of the processing tank),
4 and dry processing under the condition of
Time went. The Al fine powder generated by this operation is a fine powder having a major axis of 0.1 μm or less and the largest one having a major axis of 5 μm.
It was about μm. When the sample surface after the treatment was observed with an optical microscope (100 times), Al
It was found that the metal layer composed of fine powder was formed uniformly.

Example 2 A sample having a metal layer made of Al fine powder on the entire surface obtained in Reference Example 2 was subjected to ultrasonic cleaning for 1 minute, and then zinc-substituted at a bath temperature of 20 ° C. (liquid composition: sodium hydroxide). It was immersed in 50 g / l, zinc oxide 5 g / l, ferric chloride 2 g / l, Rochelle salt 50 g / l, sodium nitrate 1 g / l) for 1 minute to carry out zinc substitution treatment. After washing the sample, the electric Ni
The plating process was performed at a current density of 2 A / dm ² and a plating time of 60.
Min, pH 4.2, bath temperature 55 ° C, plating solution composition (nickel sulfate 240g / l, nickel chloride 45g / l, appropriate amount of nickel carbonate (pH adjustment), boric acid 30g / l). Film thickness of 16 on the metal layer made of
A plating film of μm could be formed.

Example 3 A sample having a metal layer made of fine Cu powder on the entire surface obtained in Reference Example 1 was subjected to ultrasonic cleaning for 1 minute, and then subjected to an electroless Cu plating solution (Sulcup ELC).
-SP: Uemura Industry Co., Ltd.) and plating time 3
When electroless Cu plating treatment was performed for 0 minute at a bath temperature of 60 ° C., the film thickness was 2 μm on a metal layer composed of Cu fine powder.
Could be formed.

Reference Example 3 A 3 cm square block made of the epoxy resin of Reference Example 1 was replaced with 3c made of a polyvinyl chloride resin.
Processing was performed in the same manner as in Reference Example 1 except that the m-block was replaced. As a result, it was possible to uniformly form a metal layer made of Cu fine powder on the entire block surface.

Reference Example 4 A treatment was performed in the same manner as in Reference Example 1 except that the 3 cm square block made of epoxy resin of Reference Example 1 was replaced with a 3 cm square block made of acrylic resin. As a result, it was possible to uniformly form a metal layer made of Cu fine powder on the entire block surface.

Reference Example 5 A treatment was performed in the same manner as in Reference Example 1 except that the 3 cm square block made of epoxy resin in Reference Example 1 was replaced with a 3 cm square block made of silicone rubber. As a result, it was possible to uniformly form a metal layer made of Cu fine powder on the entire block surface.

Reference Example 6 A treatment was performed in the same manner as in Reference Example 1 except that the 3 cm square block made of epoxy resin in Reference Example 1 was replaced with a 3 cm square block made of Teflon. As a result, it was possible to uniformly form a metal layer made of Cu fine powder on the entire block surface.

Reference Example 7: A 3 cm square block made of the epoxy resin of Reference Example 2 was replaced with 3c made of a polyvinyl chloride resin.
The processing was performed in the same manner as in Reference Example 2 except that the m-square block was used. As a result, a metal layer composed of Al fine powder could be uniformly formed on the entire block surface.

Reference Example 8 A treatment was performed in the same manner as in Reference Example 2 except that the 3 cm square block made of epoxy resin in Reference Example 2 was replaced with a 3 cm square block made of acrylic resin. As a result, a metal layer composed of Al fine powder could be uniformly formed on the entire block surface.

Reference Example 9 A treatment was performed in the same manner as in Reference Example 2 except that the 3 cm square block made of epoxy resin in Reference Example 2 was replaced with a 3 cm square block made of silicone rubber. As a result, a metal layer composed of Al fine powder could be uniformly formed on the entire block surface.

Reference Example 10 A treatment was performed in the same manner as in Reference Example 2 except that the 3 cm square block made of epoxy resin in Reference Example 2 was replaced with a 3 cm square block made of Teflon. As a result, a metal layer composed of Al fine powder could be uniformly formed on the entire block surface.

Reference Example 11: 70 vol% of strontium ferrite powder having an average particle diameter of 1.22 μm and 30 vol% of a polyester elastomer were mixed with a Hensyl mixer, and then formed by a biaxial co-extrusion molding machine. 10mm made of polyester elastomer
× 10 mm × 100 mm bonded magnets were manufactured. The surface of the bonded magnet was polished with a No. 280 emery abrasive paper to roughen the surface. Next, 20 bonded magnets whose surface was roughened (apparent volume: 0.2 liter) and a short columnar Cu of 2 mm in diameter and 2 mm in length having an apparent volume of 2 liters.
1. Volume of fine powder-generating substance (cut wire)
It is charged into the processing tank of an 8 liter vibrating barrel device (total charging amount is 79 vol% of the processing tank internal volume), and the vibration frequency is 60H.
The treatment was performed dry for 4 hours under the conditions of z and a vibration amplitude of 1.5 mm. The Cu fine powder generated by this operation is a fine powder having a long diameter of 0.1 μm or less and a long fine powder having a long diameter of 5 μm.
m. When the surface of the bonded magnet after the treatment was observed with an optical microscope (100 times), Cu
It was found that the metal layer composed of fine powder was formed uniformly.

Example 4: For the bonded magnet having a metal layer composed of Cu fine powder on the entire surface obtained in Reference Example 11,
When an electric Ni plating process was performed under the same conditions as in Example 1, a 13 μm-thick plated film could be formed on the metal layer made of Cu fine powder. As described above, the metal layer composed of the Cu fine powder formed on the entire surface of the bonded magnet whose surface is substantially made of the polyester elastomer is useful as an underlayer for performing an electroplating process on the bonded magnet. By forming a plating film on the surface of the metal layer by electroplating, the effect of improving the mechanical strength of the magnet (prevention of cracking) can be obtained,
The generation of magnetic fine powder due to cracking of the magnet was prevented.

Reference Example 12 A treatment was performed in the same manner as in Reference Example 1 except that the 3 cm square block made of epoxy resin in Reference Example 1 was replaced with a 3 cm square block made of FRP (fiber reinforced plastic). As a result, it was possible to uniformly form a metal layer made of Cu fine powder on the entire block surface.

Reference Example 13 The following treatment was performed using a 3 cm square block made of epoxy resin as a sample. First, the surface of the sample was polished with # 280 emery abrasive paper to roughen the surface. Next, 10 samples whose surface was roughened (apparent volume: 0.27 liter) and a short columnar Ni fine powder producing material having a diameter of 2 mm and a length of 2 mm (obtained by cutting a wire) having an apparent volume of 2 liters were used. It was charged into a processing tank of a 2.8-liter vibration barrel device (total charging amount was 81 vol% of the internal volume of the processing tank), and dry processing was performed for 4 hours under the conditions of a vibration frequency of 60 Hz and a vibration amplitude of 1.5 mm. . The Ni fine powder generated by this operation is:
From the fine powder having a major axis of 0.1 μm or less to the largest fine powder, the major axis was about 5 μm. Observation of the sample surface after the treatment with an optical microscope (100 times) revealed that a metal layer composed of Ni fine powder was uniformly formed on the entire surface.

Example 5: A sample having a metal layer made of Ni fine powder on the entire surface obtained in Reference Example 13 was subjected to ultrasonic cleaning for 1 minute, and then subjected to an electroless Ni plating solution (Nimden SX:
Electroless Ni plating was performed under the conditions of a plating time of 30 minutes and a bath temperature of 90 ° C. using a Uemura Kogyo Co., Ltd .; We were able to. Subsequently, when an electric Ni plating treatment was performed under the same conditions as in Example 1, a plating film having a thickness of 15 μm could be formed.

[0037]

According to the method for forming a metal film on the surface of a resin molded product of the present invention, a metal film excellent in film thickness accuracy and surface smoothness and having high peel strength can be easily formed on the surface of the resin molded product. be able to.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C23C 18/38 C23C 18/38 C25D 5/22 C25D 5/22 5/56 5/56 Z (72) Invention Sumitomo Kikui 2-15-17 Egawa, Shimamoto-cho, Mishima-gun, Osaka Prefecture Inside the Yamazaki Works, Sumitomo Special Metals Co., Ltd. F term (reference) in Yamazaki Works 4K022 AA14 AA15 AA16 AA18 AA19 AA20 AA23 AA25 AA35 BA02 BA08 BA14 CA02 CA11 DA09 DB16 4K024 AA03 AA09 AB15 BA13 BC08 CA03 CA04 CA06 DA10 4K044 AA16 AB01 BA06 BB11 CA29

Claims (8)

[Claims] 1. A method according to claim 1, wherein the resin compact and the metal fine powder-generating substance are accommodated in a processing vessel, and the metal fine powder-generating substance is brought into fluid contact with the surface of the resin molded body in the processing vessel. Metal fine powder is generated from the fine powder generating substance, and after forming a metal layer made of the metal fine powder on the surface of the resin molded body, a metal coating is formed on the metal layer. Method for forming a coating (however, R-Fe-B based bonded magnets are excluded from the resin molded body). 2. The method according to claim 1, wherein the metal fine powder-generating substance is brought into fluid contact with the surface of the resin molded body by applying vibration to the resin molded body and the metal fine-particle generating substance and / or stirring both of them. The method according to claim 1. 3. The method according to claim 1, wherein the processing container is a processing tank of a barrel device. 4. The method according to claim 1, wherein the treatment is performed dry. 5. The method according to claim 1, wherein the metal fine powder generating substance is Cu, Sn, Z.
n, Pb, Cd, In, Au, Ag, Fe, Ni, C
The method according to any one of claims 1 to 4, wherein the material is a substance that generates fine powder of at least one metal selected from o, Cr, and Al. 6. The method according to claim 1, wherein the surface of the resin molded body is roughened in advance as a pre-process. 7. The method according to claim 1, wherein the metal film is formed by an electroplating process or an electroless plating process. 8. A resin molded product, wherein a metal film is formed on a metal layer made of metal fine powder formed on the surface of the resin molded product.
-B-based bonded magnets are excluded).