JPH0313317B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for partial electroplating on plastic, and more specifically, when electroplating on plastic, the non-plated portion is formed into a closed loop shape, and the loop-shaped non-plating portion is closed. The part surrounded by the plating part and the outside thereof can be respectively formed as an electroplating part, so that, for example, the number 0, the Roman letter A, and various other closed loop designs and patterns can be created in an openwork-like manner. It is possible to freely form electroplated parts with different colors, and the part surrounded by the loop-shaped non-plated part and the part outside this loop-shaped non-plated part can be made into electroplated parts of different colors. This invention relates to a method of electroplating onto plastics which gives a highly decorative and glazed appearance to plastics.

Conventionally, as a method for partial electroplating on plastic, a polymer compound solution or a coloring agent, which is less likely to roughen the surface of the plastic fabric with a surface roughening liquid, is partially applied to the plastic fabric, and then the surface is coated with a coloring agent. A method is known in which roughening is performed, followed by chemical plating, and then electroplating (Special Publications No. 16987-1987, Publication No. 29959-1971).
issue).

However, in this method, the non-plated portion is formed into a closed loop, and it is difficult to form the portion surrounded by the loop-shaped non-plated portion as an electroplated portion. For example, as shown in Figure 1, the number 0 is drawn on a rectangular box-shaped plastic molded article a with an open back side using the above-mentioned polymer compound solution or coloring agent, and the surface is roughened. When chemical plating is applied, the 0 part b is not chemically plated, and the inner part c and the outer part d are each chemically plated. However, as shown in Fig. 2, the back side of the chemically plated plastic molded product a is supported by the tips g, g of the ramus f, f of the rack e, and these tips g, g are used as contact points. When electroplating is carried out, electricity from the rack e flows through the contacts g and g to the outer part d, but the part b of 0, which is not chemically plated, flows to the inner part c.
It is cut off and no electricity flows. Therefore, any part of the outer part d of part b of 0 is electroplated, but the inner part c ends up not being electroplated.

In this case, if you make an electrical contact also to the part surrounded by the closed loop (part c inside part b of 0) and allow electricity to flow from the rack, electroplating to the inside part c will be possible. It is possible, but
It is troublesome and impractical to make an electrical contact also to the inner part c. Especially the inner part c
If it is a small part, it is very difficult to make contact here. In addition, such contact points are
In particular, when plastic is plated with electricity, these areas tend to remain as marks (contact marks).
Because of this, the appearance of the plating may be impaired, so even if contact marks occur, they are not noticeable and are usually placed on the back side of the object to be plated, where there is less risk of deteriorating the appearance. However, the inner part c
(This part should have a beautiful appearance) If you make an electrical contact, there is a risk that a contact mark will be created at this contact point and spoil the appearance. It is impractical to make contact.

The present invention has been made in order to improve the above-mentioned situation, and includes openwork-like characters in which the non-plated part is in the form of a closed loop, and the part surrounded by it and the part outside thereof are electroplated parts. Designs and patterns can be easily, reliably, and freely formed on plastic, and the part surrounded by the loop-shaped non-plating part and the part outside of the loop-shaped non-plating part have different colors. It is an object of the present invention to provide a method of partial electroplating on plastic which can be used as an electroplated part of plastics and which gives a highly decorative and glazed appearance.

That is, in order to achieve the above object, the present invention roughens the surface of plastic, attaches catalytic metal nuclei to the roughened surface, and then performs chemical plating, after which a part of the chemically plated film is blocked. A non-conductive masking layer was formed to form a desired character, design or pattern including loops, and then electroplating was performed to form an electroplated film on the chemically plated film other than the masking layer. After that, removing the masking layer,
Furthermore, the chemically plated film in the part that appeared by removing this masking layer is removed, and the text, design, or pattern part containing the closed loop is made into a non-plated part, and finally from this loop-shaped non-plated part. Electroplating is performed on the outer electroplated film to form an electroplated film having a different color from the surface layer of this plated film, and the area surrounded by the loop-shaped non-plated portion and this loop-shaped non-plated part are separated. The outer portions are electroplated with different colors.

According to the present invention, the non-conductive masking layer is formed in a closed loop shape, and the chemically plated film is formed in the portion surrounded by the loop-shaped masking layer and the chemically plated portion in the outside portion thereof. The film is continuous with the chemically plated film below the loop masking layer, so if you make a contact at a desired point on the chemically plated film outside the loop masking layer and apply electricity, the loop masking layer will be connected to the film. Electricity also flows through the area surrounded by the layer, and this area is also well electroplated. After electroplating is performed in this manner, the masking layer is removed, and the chemically plated film in the area exposed by the removal of the masking layer is removed to form a character including the closed loop. , the design or pattern part is used as a non-plated part, and finally the electroplated film outside the loop-shaped non-plated part is electroplated to form an electroplated film with a different color from the surface layer of this plated film. As a result, the part surrounded by the loop-shaped non-plated part is blocked by this non-plated part and no electricity flows, so the part surrounded by the loop-shaped non-plated part is not plated. , only the part outside the loop-shaped non-plated part is plated, and this makes it very easy to differentiate the part surrounded by the loop-shaped non-plated part and the part outside this loop-shaped non-plated part from each other. It can be used as an electroplating part. Therefore, it is not necessary to make an electrical contact in the area surrounded by the loop-shaped masking layer, and contact marks that spoil the plating appearance are not generated in this area. It is possible to improve the electroplating appearance of the portion surrounded by the non-plated portion (non-plated portion), and to easily and reliably electroplate this portion.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

In the present invention, the type of plastic to be plated is not particularly limited, and plastics commonly used for plating, such as ABS resin, polycarbonate resin, and polypropylene resin, can be used.

In electroplating on plastic according to the present invention, the surface of the plastic to be plated is first subjected to a roughening treatment. This roughening treatment is carried out by adopting an appropriate physical or chemical roughening treatment method depending on the type of plastic used and its surface condition. For example, in the case of ABS resin, chromic acid
Commonly used roughening treatment methods include etching with a sulfuric acid solution, or pre-etching with an appropriate solvent in the case of polycarbonate resin, followed by etching with the above-mentioned chromic acid-sulfuric acid solution. is used.

After the surface of the plastic is roughened, an activation treatment is performed to attach catalytic metal nuclei to the roughened surface. A commonly used activation method can also be used for this activation process. for example,
A method of immersing in an acidic solution of stannous chloride (sensitizing treatment) and then immersing it in an acidic palladium chloride solution (activating treatment), a method of immersing a colloid of stannous chloride and palladium chloride in an acidic solution, and then immersing it in an acid or alkali solution. Various methods can be selected and adopted as appropriate, such as immersion in a solution, immersion in an acidic palladium chloride solution, and then immersion in a reducing agent solution, which attach catalytic metal nuclei such as metallic palladium to the plastic surface. be.

Next, after the above activation treatment, chemical plating is performed to form a chemically plated film on the surface to which the catalyst metal nuclei are attached. The type of chemical plating is not particularly limited, and chemical plating can be performed using a commonly used chemical copper plating solution, chemical nickel plating solution, or the like. In this case, the thickness of the chemically plated film is not necessarily limited, but it is preferably about 0.1 to 1 μm thick.

FIG. 3 shows the chemically plated film 2 formed on the plastic molded article 1 through the above processing steps.

In the present invention, after chemical plating, a desired character containing a partially closed loop on the chemical plating film,
A non-conductive masking layer forming a design or pattern is formed. This masking layer can be formed using a solution of resist ink or other appropriate non-conductive substance, and by employing an appropriate method such as a printing method.

4 and 5 show a state in which a non-conductive masking layer 3 forming a square frame pattern including closed loops 3a is formed on the chemically plated film 2. FIG.

Next, after forming a masking layer, electroplating is performed. In this case, as shown in FIG. 5, the contact points are located at appropriate locations on the chemically plated film 2a outside the loop-shaped masking layer 3, preferably on the back side of the object to be plated (plastic molded product). The location should be such that the appearance of the plating will not be impaired even if it occurs (in Fig. 5, 4 is the rack, 5 is the ramus, and 6 is the contact point C of the tip of the ramus).

Here, the type of electroplating is not limited, and the electroplating film may be a single layer or a multilayer. for example,
A three-layer structure of copper-nickel-chromium can be used as multilayer plating.

During this electroplating process, the chemically plated film portion 2b surrounded by the loop-shaped masking layer 3a is separated from the chemically plated film portion 2a on the outside and under the loop-shaped masking layer 3a, as shown in FIG. Since it is continuous through the chemically plated film portion 2c, the contact 6 is connected only to the outer chemically plated film portion a.
Even if you just remove the loop-shaped masking layer 3,
Electricity also flows through the chemically plated film portion 2b inside a.
Therefore, as shown in FIG. 6, the electroplated film 7 is formed not only on the outer chemically plated film portion 2a of the loop-shaped masking layer 3a but also on the inner chemically plated film portion 2b.

After forming the electroplated film in this way,
By removing the masking layer using an appropriate dissolving solution (Fig. 7), and then removing the chemically plated film revealed by the removal of the masking layer using an appropriate dissolving solution (Fig. 8). As shown in FIG. 9, the character, design, or pattern portion including the closed loop becomes the non-plated portion 8, and the outside and inside of this loop-shaped non-plated portion 8a are respectively electroplated portions 7.
a, 7b, openwork-like display (letters,
A design or pattern) is formed on the plastic material 1.

Note that when a dissolving solution is used to remove the masking layer and the chemically plated film, it is preferable to select a dissolving solution that does not dissolve the electroplated film.

After the above-mentioned chemical plating film removal process, contacts are made again at appropriate locations on the electroplated part 7a outside the loop-shaped non-plated part, and the electroplated part 7a is further placed on this electroplated part 7a. , 7b, electroplating is performed to form an electroplated film with a different color. In this case, the inner part surrounded by the loop-shaped non-plated part is blocked by the loop-shaped non-plated part and no electricity flows, so no further electroplated film is formed in this inner part. . Therefore, when this method is used, electroplated films of different colors can be formed inside and outside the loop-shaped non-plated portion, and an interesting electroplated appearance can be provided.

In addition, when transparent plastic is used, when forming a non-conductive masking layer that forms letters, designs, or patterns containing partially closed loops on the chemically plated film, a masking layer corresponding to this masking layer is used. Forming a non-conductive masking layer with the same letters, designs or patterns on the back side of the plated object, or forming a non-conductive masking layer at the required location including the masking layer corresponding part on the back side of the plated object, When removing the non-conductive masking layer and chemical plating film on the front side after electroplating, the non-conductive masking layer and chemical plating film on the back side can be removed at the same time. When used, a very sharp raised loop-shaped display can be formed.

As explained above, according to the present invention, a closed loop-shaped character is formed in which the non-plated portion is closed and the portion surrounded by the loop-shaped non-plated portion and the outside thereof are electroplated portions, To easily, reliably, and freely produce a pattern or pattern in an openwork-like electroplated appearance. Furthermore,
The part surrounded by the loop-shaped non-plated part and the part outside of this loop-shaped non-plated part can be made into electroplated parts of different colors, making the plating very attractive and highly decorative. can give an appearance.

Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the following Examples.

Example An ABS resin molded product was etched by immersing it in the following etching solution CrO ₃ 400 g/H ₂ SO ₄ 200 ml/ at 65°C for 10 minutes, followed by water washing, neutralization, and water washing. After rinsing with water, immerse in the following activating solution PdCl _{2 2} g/HCl PH2 for 1 minute at room temperature, and then apply chemical nickel plating to approximately 0.2 μm. A chemically plated film was formed.

Next, a non-conductive masking layer consisting of a square frame pattern as shown in Figure 4 was formed using PR3003 metal resist manufactured by Hi-Sot Japan Co., Ltd., followed by bright copper sulfate plating and bright nickel plating. Then, chrome plating was applied sequentially. In this case, the contact was placed on the back side of the covered object as shown in FIG.

After electroplating, the masking layer was dissolved and removed using a 15% caustic soda solution, and then the chemical nickel plating film revealed by the removal of the masking layer was removed using a 15% caustic soda solution.
It was dissolved and removed using % nitric acid. With this, the 9th
As shown in the figure, an electroplated film was formed which had an openwork-like display area with a square frame-shaped pattern as a non-plated area. In this case, the electroplated appearance surrounded by the loop-shaped non-plated portion was good.

The contacts were then made as shown in Figure 5 and electrolyzed in a caustic soda solution with the item as the anode. As a result, the chrome plating film on the electroplated part outside the loop-shaped non-plated part was electrolytically peeled off and the nickel plating film was exposed, but the chrome plating film in the part surrounded by the loop-shaped non-plated part was removed. The film was not peeled off because it was in an electrically disconnected state.

After the chrome plating film on the electroplated portion outside the loop-shaped non-plated portion was peeled off in this manner, gold plating was applied. As a result, a gold-plated film is formed only on the nickel-plated film of the electroplated part outside the loop-shaped non-plated part, while the electroplated part surrounded by the loop-shaped non-plated part is formed as described above. As the chrome plating film is not peeled off and the gold plating film is not formed, electroplated films of different colors are formed inside and outside the loop-shaped non-plated part, and
The loop-shaped non-plated portions are multi-colored partial plating with an extremely excellent appearance that gives an openwork-like interest.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing the state in which a non-plated part consisting of closed loop-shaped characters is formed on a plastic molded product, and Figure 2 shows the support mode and contact points of the rack when electroplating a plastic molded product. 3 to 9 are side sectional views showing an embodiment of the method of the present invention. FIG. 3 is a sectional view of a plastic molded product with a chemically plated film formed thereon, and FIG. is a plan view of a state in which a non-conductive masking layer consisting of characters including closed loops is formed;
Fig. 5 is a cross-sectional view showing how the plastic molded product is supported by the rack and the contact points, Fig. 6 is a cross-sectional view showing the state after the electroplated film is formed, and Fig. 7 is a cross-sectional view showing the state after the masking layer is removed. 8 are cross-sectional views showing the state after the chemical plating film has been removed, and FIG. 9 is a plan view thereof. 1... Plastic molded product, 2... Chemically plated film, 3... Masking layer, 7... Electroplated film,
8...Non-metal part.

Claims (1)

[Claims] 1. After roughening the plastic surface, adhering catalytic metal nuclei to this roughened surface, and then applying chemical plating, desired characters, designs, or patterns containing partially closed loops are formed on the chemically plated film. a non-conductive masking layer is formed, and then electroplating is performed to form an electroplated film on the chemically plated film other than the masking layer, the masking layer is removed, and the masking layer is removed. The portion of the chemically plated film that appears when the layer is removed is removed, and the character, design, or pattern portion containing the closed loop is made into a non-plated portion, and finally, the area outside of this loop-shaped non-plated portion is electrically coated. Electroplating is performed on the plated film to form an electroplated film having a different color from the surface layer of the plated film, and the area surrounded by the loop-shaped non-plated part and the outside of the loop-shaped non-plated part are A method for partial electroplating on plastic, characterized in that the parts are electroplated parts of different colors.