JPS6245315B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to fiber-reinforced plastics (hereinafter referred to as
This relates to a method of metallizing the surface of plastic molded products such as FRP waveguides with good surface precision and good adhesion.

Conventionally, methods of metallizing the surface of plastic molded products include vapor phase plating methods such as vapor deposition, ion plating, and sputtering, electroless plating methods, and methods of applying conductive paint. However, the vapor phase plating method has poor weather resistance because the metal layer obtained is as thin as several microns or less, and if the shape of the object to be processed is curved, the thickness of the obtained metal layer may be uneven. However, there was a drawback that the size of the object to be processed was limited depending on the size of the bell gear used.

In addition, when electroless plating is applied to plastic molded products, it is difficult to activate the surface, except for some products (ABS resin, copper-clad laminates for printed wiring boards, etc.). If there are parts where the metal layer does not deposit, or if you try to deposit it uniformly, the surface to be treated will be extremely roughened mechanically or chemically, resulting in poor surface precision.

Further, even if it could be deposited uniformly, its adhesion was extremely weak, making it unsuitable for practical use.

On the other hand, with the method of applying conductive paint, it is difficult to apply a uniform film thickness depending on the shape of the object to be treated. It had the disadvantage that its properties such as hardness and hardness were significantly inferior to those of metals.

This invention was made in order to improve the above-mentioned drawbacks of the conventional ones, and it is possible to apply the metal layer necessary for the core metal for plastic molding made of aluminum alloy with the necessary thickness and combination by, for example, electrolytic plating. At the same time as depositing, a primer is applied on top of it to firmly adhere to the plastic to be molded. After that, it comes into close contact with the plastic to be molded,
A resin that cures at the same time as the primer is applied and cured. After molding the plastic and performing the necessary processing, the aluminum alloy core metal is melted and removed to create a metalized plastic molded product with good surface accuracy, adhesion, and excellent weather resistance. The purpose is to provide a manufacturing method that can obtain

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 7.

In FIG. 1, reference numeral 1 denotes a molding core metal made of aluminum alloy 5056, which has the same external shape as the required curved plastic molded product and the internal shape, and is finished with the required surface accuracy. 1 on this core metal
Then, as shown in FIG. 2, the necessary metal layers are plated to the required thickness in the order of, for example, copper strike plating 2, gold plating 3, and copper plating 4, using electrolytic plating. Next, add copper plating 4, which is the outermost plating layer.
Polish the surface using a polishing cloth to give it an uneven surface. Next, the copper surface is oxidized by immersing it in a solution consisting of 0.5 mole of sodium hydroxide and 0.19 mole of potassium persulfate at a temperature of 50° C. for about 2 minutes.

Next, as shown in Figure 3, apply EC-2290 to this surface.
(Manufactured by Sumitomo 3M Co., a coating material mainly composed of epoxy resin) Apply primer 5 to the entire surface, dry to the touch, and then dry at 80°C for 2 hours. If this primer 5 is not used, the subsequent plastic molding will be incomplete.

Next, as shown in Figure 4, a varnish or resin 6 consisting of 125 parts of DX210-80 (epoxy resin manufactured by Ciel), 3 parts of BF ₃ 400 (curing agent manufactured by Ciel) and 44 parts of methyl ethyl ketone is applied to the entire surface and cured. . If this resin layer 6 is not used, when plastic, especially fiber-reinforced plastic, is later molded, there will be areas where the fibers and the metallized layer come into direct contact, which will later become areas with poor adhesion. Next, as shown in Figure 5, DX-210-80 (Ciel epoxy resin) 125
A varnish consisting of 3 parts BF ₃ 400 (Ciel hardener) and 44 parts methyl ketone was applied to a glass cloth EC113.
(manufactured by Arisawa Seisakusho) and dried at room temperature for 30 minutes or more and at 80 to 100° C. for 10 minutes, the prepreg 7 is attached to the resin layer 6. Using an autoclave, the product prepared in this way is weighed at 0.5 to 4.5 kg/
Primary curing was performed at 150° C. for 30 minutes under a pressure of cm ² and secondary curing was further performed at 170° C. for 4 hours. Thereafter, as shown in FIG. 6, the core bar 1 is dissolved and removed in a solution containing 3 moles of sodium hydroxide at about 50°C. Next, as shown in FIG. 7, necessary machining is performed. After that, the copper strike plating layer 2 was immersed in a solution consisting of 12 mol of nitric acid for about 30 seconds at room temperature.
When removed by melting, a gold-plated 3-treated product with copper plating 4 as a base is obtained on the inner surface of the epoxy resin molded product reinforced with glass cloth. The metal layer obtained by this treatment has good peel strength, that is, good adhesion, and also has excellent surface accuracy because the surface condition of the aluminum alloy core is transferred as is. have In addition, a metal layer,
By providing the resin layer 6 between the reinforcing fibers, uniform adhesion can be obtained and weather resistance is also excellent.

In addition, in the example, the manufacturing method of the gold plating 5 treated product with the copper plating 4 as the base on the inner surface and flange joint surface of the epoxy resin molded product 7 reinforced with glass cloth was shown. Since the core metal 1 is used, any shape and surface precision that can be obtained by machining can be obtained, and the metal layer can be deposited directly on the core metal 1 by, for example, electrolytic plating. All types and combinations of metallization can be performed, and the film thickness can be obtained as required. In addition, by selecting a primer and resin that have good adhesion to the surface metal layer and the thermosetting resin to be molded, it can be applied to all thermosetting resins (including those reinforced with fibers).

[Brief explanation of the drawing]

1 to 7 are explanatory diagrams showing one embodiment of the method of metallizing the surface of a plastic molded product according to the present invention. In the figures, 1 is a core metal for plastic molding, and 2 is a copper strike plating layer. , 3 is a gold plating layer, 4 is a copper plating layer, 5 is a primer layer, 6 is a resin layer, and 7 is a glass cloth base epoxy molded product. It should be noted that the same or corresponding parts in the figures are indicated by the same reference numerals.

Claims (1)

[Claims] 1. Precipitate the necessary metal by electrolytic plating on a core metal for plastic molding made of aluminum alloy, apply a primer that adheres to the deposited metal, and then
A resin that adheres to the plastic to be molded and hardens at the same time as the primer is applied and cured, and then the plastic is molded on top of that, and then the aluminum alloy core metal is melted and removed, and the required processing is carried out. 1. A method for metallizing a surface of a plastic molded product, characterized in that a metal layer is attached to the surface of the plastic molded product by applying a metal layer to the surface of the plastic molded product.