JP2948366B2 - Partial plating method for plastic moldings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of partially plating plastic molded articles.

[0002]

2. Description of the Related Art As a method of giving decorations such as initials to the surface of a plastic molded body such as a button, a method of printing using a paint of a required hue is generally used. However, this method has a disadvantage that if a metal layer is formed on the button surface in advance, the surface is a smooth surface, so that the coating layer is peeled off and the quality of the appearance is likely to deteriorate. Such a drawback can be solved by a method of selectively forming a metal layer, particularly an electroplated metal layer, only in a predetermined region of a plastic molded body.

[0003]

However, the conventional methods for selectively forming a metal layer have extremely low production efficiencies, such as providing a masking layer. It could not be applied to articles that were required to be inexpensive.

[0004] In view of the above problems, the object of the present invention is to:
Using plastic plating technology and laser processing technology,
An object of the present invention is to realize a partial plating method of a plastic molded body that can form an electrolytic plating layer only in a predetermined region without lowering production efficiency.

[0005]

Means for Solving the Problems In order to solve the above problems, in the method for partially plating a plastic molded article according to the present invention, the means taken is to pattern an electroless plating layer formed by plastic plating by laser processing. After that, an electrolytic plating process is performed. That is, a plastic molded body having a predetermined shape is immersed in an etching solution to roughen the outer peripheral surface (roughening step), and then the roughened molded body is immersed in an activating liquid. A metal catalyst core is attached to the outer peripheral surface (activation step). Next, the molded body in this state is immersed in an electroless plating solution to form an electroless plating layer on the outer peripheral surface thereof (electroless plating step). It is hollowed out so that the surface of the molded body is exposed at that part (laser processing step). Thereafter, electrolytic plating is performed on the electroless plating layer left on the outer peripheral surface of the molded body to form an electrolytic plating layer (electrolytic plating step).

[0006]

In the partial plating method having the above structure,
When electroplating is applied to the electroless plating layer formed by plastic plating in the state where the non-electrolytic plating layer non-forming area is provided by using laser processing, the electroless plating layer causes the electroless plating layer to become conductive. Only in the region where the electroplating layer has grown and the electroless plating layer has been hollowed out, the electroplating layer does not grow. Here, the electroless plating layer
It is a power supply portion in electrolytic plating, and its thickness, for example, about 0.2 μm is sufficient.
Therefore, the processing time required to cut out the electroless plating layer by laser processing is extremely short, so that the production efficiency does not decrease.

[0007]

Next, a method for partially plating a button according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic sectional view of the button of the embodiment, and FIG. 2 is a perspective view of the button.

As shown in these figures, the base of the button 1 is a molded body 10 made of a disc-shaped milky white ABS resin, and an initial part 2 as a decorative part 2 is formed on the surface 1a side. "TH" is marked.
On the other hand, on the side of the back surface 1b, there is provided a button mounting portion 3 having a mounting hole 3a. The outer peripheral surface of the molded body 10 is covered with an electroless Ni plating layer 4 having a thickness of about 0.2 μm.
An electrolytic Cu plating layer 5 having a thickness of about 10 μm;
an electrolytic Ni plating layer 6 having a thickness of about 5 μm on the u plating layer 5 and a thickness of about 0.03 μm on the electrolytic Ni plating layer 6;
μm electrolytic Au plating layer 7. Here, on the surface side of the molded body 10, there is a region where these plating layers are not formed, and this region is the decorative processed portion 2. In the decorative processing part 2, the surface of the molded body 10 is in an exposed state.

In the button 1 having this configuration, the decorative processing portion 2 is different from the one printed on the surface, due to the difference between the hue of the electrolytic Au plating layer 7 as the outermost surface layer and the hue of the base of the molded body 10. Because it is formed, it does not disappear during use. Therefore, the appearance quality is maintained high for a long time.

Next, a method of manufacturing the button 1 having this configuration will be described.

First, a milky white disk-shaped molded body 10 made of ABS resin is prepared.

Next, the molded body 10 is immersed in an etching solution having the following composition at about 65 ° C. for about 10 minutes.

Etching solution composition Chromic anhydride about 400 g / l Sulfuric acid about 400 g / l As a result, the outer peripheral surface of the molded body 10, that is, the surface 1a
And the back surface 1b as well. (Roughening step).

Next, after performing washing, neutralization and washing with water, the molded body 10 is immersed sequentially in a catalyst solution and an accelerator solution of about 35 ° C. having the following composition to obtain a roughened molded body. Palladium as a metal catalyst nucleus is attached to the surface of 10 (activation step).

Catalyst liquid composition Palladium chloride Approx. 50 g / L Hydrochloric acid (35% by volume) Approx. 200 cc / L Accelerator liquid composition Hydrochloric acid (35% by volume) Approx. 20 cc / L Ni with
By dipping in an electroless plating solution, an electroless Ni plating layer 4 is formed on the entire outer peripheral surface of the molded body 10 as shown in FIG.
(Electroless plating step).

Ni electroless plating composition Nickel sulfate about 20 g / l Sodium acetate about 5 g / l sodium hypophosphite about 10 g / l sodium citrate about 5 g / l Next, with respect to the surface 1a side of the molded body 10, By irradiating a laser beam along the pattern of “TH”, as shown in FIG. 4, the electroless Ni plating layer 4 is partially hollowed out and the surface of the molded body 10 is exposed there (laser Processing step).

Next, an inconspicuous portion of the electroless Ni plating layer 4 left on the molded body 10, for example, the electroless Ni plating layer 4 of the fixing portion 3 is used as a power supply portion, and the following electrolytic plating process is performed. I do. This electrolytic plating step may be performed only once, but may be performed a plurality of times by changing the type of plating solution depending on the use of the button 1 or the like. In this example, three electrolytic plating steps are performed as follows to form three electrolytic plating layers as shown in FIG.

First, the gloss of the surface of the button 1 is increased,
In order to improve the quality of the appearance, as a first electrolytic plating step, the molded body 10 is subjected to electrolytic Cu plating in an electrolytic Cu plating solution having the following composition to form the electroless Ni plating layer 2. An electrolytic Cu plating layer 5 having a thickness of about 10 μm is formed thereon. Here, since the electrolytic Cu plating layer 5 grows only on the electroless Ni plating layer 4, the electroless Cu
The electrolytic processing part 2 in which the i-plated layer 4 is hollow
The u-plated layer 5 does not grow, and the surface of the molded body 10 remains exposed (first electrolytic plating step).

Cu plating composition Copper sulfate about 200 g / l Sulfuric acid about 50 g / l Next, as a second electrolytic plating step, electrolytic Ni plating is performed in an electrolytic Ni plating solution having the following composition, and electrolytic Cu plating is performed. An electrolytic Ni plating layer 6 having a thickness of about 5 μm is formed only on the plating layer 5 (second electrolytic plating step).

Ni Plating Composition Nickel sulfate about 300 g / l Nickel chloride about 50 g / l Finally, as a third electrolytic plating step, electrolytic Au plating treatment is performed in an Au plating solution having the following composition,
Only on the electrolytic Ni plating layer 6, the thickness is about 0.03 μm
Is formed (third electrolytic plating step).

Au plating composition Approximately 10 g / liter of potassium gold cyanide Approximately 35 g / liter of potassium cyanide Approximately 35 g / liter of potassium carbonate Approximately 35 g / liter of dibasic potassium phosphate
An electrolytic Cu plating layer 5 and an electrolytic Cu
The plating layer 5 and the electrolytic Au plating layer 7 are formed,
In the decorative processed part 2 from which the electroless Ni plating layer 3 is hollowed out, the surface of the molded body 10 remains exposed, and since this region is not conductive, no electrolytic plating layer is formed. Therefore, the initial “TH” as the decorative part 2 is formed in a state in which it is cut into each electrolytic plating layer.

Here, the decorative processed part 2 is one in which each electrolytic plating layer is formed as a result of the formation area defined by the electroless plating layer 4 in which a hollow part is formed using a laser, The entire plating layers are not hollowed out by laser processing. That is, only the electroless plating layer 4 having a thickness of about 0.2 μm is cut out by laser processing, and the time required for laser processing can be shortened because the cutout thickness is small. Therefore, since the production efficiency is not reduced, the laser processing step can be applied to the production of an inexpensive product such as the button 1. In addition, when the boundary between the decorative processed part 2 and each plating layer is observed, the parting surface is beautiful.

The etching solution, the activating solution, and the electroless plating solution are not limited to the above-described solution compositions. For example, electroless Cu plating may be used instead of electroless Ni plating. .

In the electrolytic plating step, the type of plating is not limited. For example, electrolytic black chrome plating may be used instead of electrolytic Au plating. That is,
Each plating type, composition of each processing solution, and the like have properties to be set according to the type of button to be manufactured, the type of molded article to be manufactured, the application, and the like.

Further, treatments such as washing and drying may be performed in each step or between each step, and in addition, various post-treatments may be performed on the formed outermost surface layer. It is.

The material of the molded body is not limited to the ABS resin, but may be any of acrylic, polycarbonate, polyacetal, polyimide, noryl, polypropylene, and any other materials that can be plated with plastic. May be used.

[0028]

As described above, the present invention is characterized in that, in the laser processing step, the electroplating step is performed after the electroless plating layer formed by plastic plating is partially hollowed out. Therefore, according to the present invention, since the region where the electrolytic plating layer is formed is defined by the partially left electroless plating layer, the following effects are obtained. An electroless plating layer can be partially formed without forming a masking layer or the like. Moreover, since the laser processing is performed only on the electroless plating layer, the processing time is short. Therefore, since the production efficiency does not decrease, the range in which this method can be adopted is wide, and it can be applied to the manufacture of low-priced products such as buttons. Further, since the electrolytic plating layer grows along the region where the electroless plating layer is formed, the quality of the parting surface at the boundary between the region where the electrolytic plating layer is formed and the region where it is not formed is high.

[Brief description of the drawings]

FIG. 1 is a sectional view of a button according to an embodiment of the present invention.

FIG. 2 is a perspective view of a button according to the embodiment of the present invention.

FIG. 3 is a process cross-sectional view showing a part of the method for manufacturing a button according to the embodiment of the present invention.

FIG. 4 is a process cross-sectional view illustrating a part of the method of manufacturing the button according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Button 2 ... Decorative processing part 4 ... Electroless Ni plating layer 5 ... Electrolytic Cu plating layer 6 ... Electrolytic Ni plating layer 7 ... Electrolytic Au plating layer

Claims (2)

(57) [Claims] 1. A roughening step of immersing a plastic molded body having a predetermined shape in an etching solution to roughen an outer peripheral surface thereof, and immersing the roughened molded body in an activating liquid. An activation step of attaching a metal catalyst nucleus to an outer peripheral surface thereof; and an electroless plating method comprising: immersing the molded body having the metal catalyst nucleus attached thereto in an electroless plating solution to form an electroless plating layer on the outer peripheral surface thereof. A plating step; a laser processing step of partially hollowing out the electroless plating layer formed on the outer peripheral surface of the molded body by using a laser to expose the surface of the molded body at that portion; On the other hand, electrolytic molding is performed by using the electroless plating layer left on the outer peripheral surface thereof, and an electrolytic plating step of forming an electrolytic plating layer on the electroless plating layer is provided. Body partial plating method 2. A method for partially plating a plastic button, wherein the method according to claim 1 is used.