JPS5952626A - Molding method - Google Patents

Abstract

PURPOSE:To obtain a housing capable of being easily molded and having an insulating function, by a method wherein an injection-molded body of a synthetic resin is subjected to metal spraying in the condition of being fixed to one side of a metallic mold, and a synthetic resin is again injection molded onto the metal- sprayed surface. CONSTITUTION:After poducing a primarily molded article 2 by an injection device 1, the metallic mold with the article 2 fitted thereto is rotated by 90 deg. by driving a rotary base for the mold. After adhering a metallic layer onto a surface of the article 2 by metal spraying by using a plasma metal spraying equipment, the mold is rotated further by 90 deg., and a resin is injection-molded onto the metallic layer on the article 2 by an injection device 5. Metallic molds 7, 9 are designated on the basis of the thickness of a molded article to be finally obtained. The metal used in plasma metal spraying may be aluminum, iron, nickel, zinc or the like, and an economical range of the thickness of the metallic layer is 1-300mu.

Description

[Detailed Description of the Invention] The present invention is applicable to microcomputers, room coolers, etc. ! The object of the present invention is to provide an integrally molded product made of synthetic resin, metal, and synthetic resin that exhibits an electromagnetic wave shielding effect for electronic circuits and electronic components used in products.

Shielding boxes made of metal plates were used to prevent interference from electromagnetic waves, but since the advent of resin, they have come to be used as housings for microcomputers and home appliances, and shielding boxes made of metal plates are almost no longer used. No longer. This is because synthetic resins are suitable materials for housings because they can be easily molded into complex shapes and also function as electrical insulators. However, in recent years, the number of home appliances with built-in C microcomputers has increased, and there has been concern that they may cause radio wave interference. In response to this, methods for molding conductive polymers are being developed.

Adding carbon black or metal powder to a synthetic resin is effective in shielding radio waves, but there is a problem in that it requires a large number of added stars, which significantly inhibits moldability. Additionally, methods have been proposed in which metals, fibers, and carbon fibers are added to synthetic resins, but a method for uniformly dispersing fibers using injection molding has not been developed, and is considered unreliable in terms of radio wave shielding. It is said. Furthermore, when these conductive supramolecules are used, they lack the insulating function as a housing, so the current situation is that this method is not very satisfactory. JP-A-56-126] 89 proposed a sandwich-shaped toxing using conductive thermosetting resin (7), but there were limitations due to molding due to thermosetting and limitations on conductive performance itself. It was inadequate in certain respects.

An object of the present invention is to provide a housing for shielding Pi waves that can be easily molded (7) and also has an insulating function.

That is, the process of injection molding a synthetic resin, fixing this molded product to one side of a mold without demolding, and then metallizing one side of the molded product by spraying metal without removing it from the mold, and then molding the synthetic resin again. The present invention relates to a method for integrally molding an electromagnetic shielding molded product made of synthetic resin-Kanariichi synthetic resin by injection molding onto a metal sprayed surface.

According to the present invention, it is possible to easily obtain an electromagnetic wave shielding housing with excellent C while maintaining various properties of conventional housings made of synthetic resin.

The synthetic resin used in the present invention only needs to have fluidity suitable for injection molding, such as polyethylene, polypropylene, polystyrene, acrylonitrile-butadiene-styrene, and It can be applied to almost all synthetic resins, such as acrylonitrile-styrene copolymer, polymethyl methacrylate, polyamide, polyacetal, and polyphenylene oquinide (abbreviated as PPO), but dimensional molding In consideration of properties, flame retardancy, etc., polyacetal, polyphenylene oxide, A B 8 [J resin, flame retardant polyolefin, etc.] are preferable. According to the method of the present invention, it is possible to integrally mold the synthetic resin 1]i7 with two or more synthetic resins without limiting it to one type.

In addition, it is preferable to use injection molded resin as a conductive -1゛ pound because it is effective in shielding electromagnetic waves (7).The metal solvent method used in the present invention is plasma spraying or gas wire , human flame bathing such as arc type 4
Various methods such as C can be used, but when considering the bonding of synthetic resin and metal, plasma bath spraying is effective because it can be thermally sprayed all at once under powerful energy. The flame solvent method can also be used effectively depending on the gold 4 used.

As the injection molding method used in the present invention, it is desirable to use a special injection molding method that has been developed as a two-color molding method.

In other words, by providing an injection device with a number of seats and a core mold rotating device, a multilayer injection molded product provided with a conductive layer can be efficiently obtained.

FIG. 1 is an example N of a molding apparatus used in the present invention.

0), ■ are injection devices, ■, ■ are synthetic resin tP, Φ) are metal IPJ ti and (('+) 1. L Solas; - J is filled with Kamefu l setting uh.

■ and ■ are made with a molding die. ■The surface of the mold has a roughening effect or the effect of 2G of nolasma bathing.

In addition, (1) is a shielding plate for plasma spraying, and (2) prevents the metal mold from being sprayed with metal.

10 is a rotary table for the molding die.

Next, the main investigation. The following process is described according to the illustration in Fig. 1. The next molded product (in injection device D) is molded L flO et al., mold rotating table. By driving the -θ (molded product), the 13E metal plate is rotated by 90°. Next, metal spraying is carried out using the Zolazma bath spraying equipment, and the next molded product surface is coated with gold V~J. →
After forming the stone, the mold is rotated at the same time as the mold (9), and the injection device (5) is used to inject the metal layer into the metal layer of the blowing process (7) and (9). The molds are designed based on the principles of 1) [1] of the molded product to be obtained by C.J. Saihiragi, respectively, and the composition of the molding thickness of ■ and ■ is not particularly limited.

FIG. 2 is a sectional view of a molded product obtained by the method of the present invention. In the same figure, C1-7-(2+,■ha1'r r
A jVr, J IJi 7 layers, ■ is a metal layer.

Metals used for plasma spraying include aluminum,
These include iron, nickel, zinc, copper and their alloys. Among these, aluminum has a low melting point and excellent bondability with synthetic resins. The thickness of the metal layer is determined by the uniformity of the metal film thickness by plasma spraying, but is usually 1μ to 8μ.
A range of 00μ can be used economically.

Depending on the shape of the molded product, a uniform film thickness can be achieved by moving the plasma gun along the shape of the molded product.

Furthermore, by roughening the surface of the molded product before metal spraying, it is possible to further improve the adhesion between the plasma sprayed metal and the synthetic resin.

Methods for roughening the surface of the molded product include a method of roughening the surface of the mold, a method of sandblasting the surface of the molded product, and the like.

For synthetic resin-metal-synthetic resin integrally molded products, it is effective to roughen the surface of the plasma-sprayed metal surface to improve adhesion, and this can be done, for example, by sandblasting.

Hereinafter, the present invention will be specifically explained based on Examples ψ).

Example 1 A 5 mm qL ABS was first molded into a box shape using an injection molding machine having a rotary mold and two injection devices shown in FIG. After the mold was rotated 90' for one turn, aluminum was plasma sprayed onto the surface of the molded product.

The thickness of the aluminum film obtained was approximately 200μ.

The main conditions for plasma spraying were as follows.

Plasma So N METCO Plasma Gun 3M1
Type 3 Plasma Gas Alcon-Hydrogen Gas Pressure and flow rate of Alcon gas (indicator): 7Kg/'cr1.80 Power and flow rate of hydrogen gas (indicator): 8.5~/2J, 15 arc current and current If 500 Amps, 65 Volts Carrier Gas Argon Flow-87 Aluminum Particle Size Average 20
00 revolutions and injection molded ABS on the aluminum surface.

The obtained integrally molded product made of ABS-aluminum-AIi8 had excellent strength and molding accuracy, and had an electromagnetic wave shielding effect of 4 Q dB.

Example 2 Polypropine having a thickness of 5 mm was first molded into a box shape using an injection molding machine having a rotary mold and two injection devices shown in FIG.

The mold was rotated 90°, and aluminum plasma spraying was performed on the surface of the molded product in the same manner as in Example 1. The thickness of the aluminum film obtained was approximately 100μ. The mold was then rotated an additional 90° and polypropylene was injection molded onto the aluminum surface. The obtained polypropylene-aluminum-polypropylene integrally molded product has good strength and mold fidelity, with an immediate i' of 35 dB;
It had an electromagnetic wave shielding effect.

Example 8 Using an injection molding machine having a rotary mold and two injection devices shown in FIG. 1, a modified polyphenylene oxyhydride (Noryl (P)) having a thickness of 5 mm was first molded into a box shape. 90 molds
Rotate (hmm) Copper plasma spraying was performed on the surface of the molded product in almost the same manner as in Example 1.
I did it on 5th. The thickness of the copper film obtained was approximately 10011. The gold was then rotated an additional 90°, and Noryl was injection molded onto the copper coated surface. The resulting integrally molded part made of noryl-copper-noryl has high strength and rigidity, and is suitable for production J1.
It also had excellent e-accuracy and an excellent electromagnetic wave shielding effect of 49 dB.

Example 4 A 5 rmn thick A I+ 8 was first molded into a box shape using a pultrusion molding machine having a rotary mold and two injection devices shown in FIG. Next, the surface of the molded product is M E 'r
The surface was roughened by grid blasting at a pressure of 4 - using a sandblasting machine manufactured by EU.

The mold was rotated 90' and aluminum R71Z was plasma sprayed on the surface of the molded product in the same manner as in Example 1. 11% and 111% of aluminum is approximately 20,071%.

This A B S-aluminum laminated material has an excellent adhesive strength of 40 dJl for aluminum.
It had an L magnetic wave shielding effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a molding apparatus used in the present invention. ■, ■: Injection device ■, ■ 2 Synthetic resin layer ■: Metal layer ■: Plasma spray equipment ■, ■: Mold G): Plasma spray shielding plate O: Mold rotary table 2nd rec is obtained by the present invention It is a sectional view of an adult elbow product. ■、■ 2 Synthetic resin layer■): Gold dust layer

Claims (5)

[Claims] (1) The process of injection molding synthetic resin, then metallizing one side of the molded product by metal spraying while fixing the molded product to one side of the mold without removing it, and then turning the synthetic resin into metal again. A method of integrally molding an electromagnetic shielding molded product made of synthetic resin, metal, and synthetic resin by injection molding onto a thermally sprayed surface. (2) The method according to claim 1, wherein the method for metallizing one side of the molded product is a blastema spraying method. (3) The method according to claim 1, wherein the method of metallizing one side of the molded product is a plasma spraying method. (4) Claims l using an injection molding tool devised to roughen the 12 surfaces of the molded product to be metal sprayed
Method described. (5) The method according to claim 1, in which a sandblasting process is performed on the surface of the molded product before metal spraying or on the metal surface after metal spraying.