JPS60131239A - Resin molded shape - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Technical Field - This invention relates to a resin molded product consisting of a light-transmitting part and a light-shielding part, such as an automobile instrument panel or various meter panels.
Specifically, the present invention relates to a resin molded product whose entire surface is made conductive.

Conventional technology Resin molded products such as automobile instrument panels and various meter panels have transparent or semi-transparent transparent parts not only for light-shielding parts, but also for viewing meters inside the molded product and recognizing the light from lighting indicators. It has a light part, and is formed by fitting the light-transmitting part into the light-shielding part or by two-color molding.

Incidentally, modern automobiles are rapidly becoming electronic, with microcontrollers controlling various parts such as the engine combustion system, air conditioning, suspension, speedometer, and warning devices.
C, clock IC, and other electronic components are installed at various locations. Electric circuits made up of these electronic components may malfunction when exposed to electromagnetic waves from the outside, or may cause problems such as emitting electromagnetic waves themselves and preventing other devices from malfunctioning.

Therefore, if the electrical circuit is installed inside the instrument panel, etc., which is not conductive, most of the electromagnetic waves will pass through the instrument panel, making it defenseless against the electromagnetic waves. There was a risk of malfunction. Even if a conductive paint was applied to the instrument panel, it could not be applied to the light-transmitting parts because it would impair its light-transmitting properties, and a sufficient shielding effect could not be obtained.

Furthermore, various general-purpose computers, word processors, and the like are sometimes covered with synthetic resin cases having a light-transmitting part and a light-blocking part, but the same problems as above occur in this case as well.

Conventionally, electronic circuits have been shielded with metal boxes to prevent malfunctions such as those described above, but there have been problems such as increased cost, increased size of electronic devices, poor assembly performance, and increased product weight.

Purpose This invention was made in order to solve the problems that existed in the past as described above, and the purpose is to make the entire transparent part conductive and to sufficiently block electromagnetic waves without impairing the transparency of the transparent part. The object of the present invention is to provide a new resin molded product that can prevent malfunctions of electric circuits such as microcomputers set inside or outside.

Structure This invention provides a resin molded article consisting of a light-transmitting part and a light-shielding part, in which a transparent conductive film made of a metal oxide is formed and covered on at least one side of the light-transmitting part, and a paint made of a conductive paint is formed on at least one side of the light-shielding part. The transparent conductive film and the paint conductive film are electrically connected to each other.

EXAMPLE A first example in which the present invention is embodied in an automobile instrument panel will be described below with reference to FIGS. 1 to 3.

1 in the drawing indicates the entire instrument panel of the automobile. Reference numeral 2 denotes a plurality of transparent light-transmitting parts provided in the instrument panel 1, which are made of a transparent methacrylic resin (PMMA) plate. Each light-transmitting part 2 is provided so that a speedometer 3, a bar graph tachometer 4, a fuel gauge 5, a water temperature gauge 6, etc., which are installed inside the instrument panel 1 and are made of LEDs, etc. can be viewed from the front. There is. 7 is a plurality of translucent parts having translucency, including a milky white translucent PM.
It is made of MA resin plate and is installed to transmit light from lighting indicators (illustrated paths) for recognizing oil pressure, door ajar, far-sight switching of headlights, underside braking, etc.

Reference numeral 8 denotes a transparent conductive film formed by sputtering on the back surface 5 of each of the transparent and translucent light-transmitting parts 2 and 7, and is made of ITO with a film thickness of approximately 1000 Å (angstroms).
(indium tin oxide) film and has a surface resistance of approximately 5 x 100 cm. Since this transparent conductive film 8 has high transparency, it does not impair the light transmittance of each light transmitting portion 2.7. The method and conditions for forming the transparent conductive film 8 will be described in detail later.

Reference numeral 9 denotes a light-shielding part molded in two colors around all the light-transmitting parts 2.7, and is made of a black ABS resin plate, and its back surface is the back surface of the light-transmitting parts 2, 7. They are almost flush with each other. The light shielding portion 9 blocks light,
The interior parts such as the speedometer 3 are made to stand out. The two-color molding method will be described later.

1O is an edge 8a having a width of approximately 2 mm that extends over the entire back surface of the light-shielding portion 9 and the entire circumference of the transparent conductive film 8 of all the light-transmitting portions 2.7.
The conductive paint film is formed by coating so as to be electrically conductive to each other, and an acrylic conductive paint containing nickel powder is used, and has a surface resistance of about 10 6 -Cm.

Due to the transparent conductive film 8 and the paint conductive film 10, the entire back surface of the instrument panel 1 is electrically conductive without any incisions.

Regarding the first embodiment configured as described above, the manufacturing method thereof will be explained next.

First, the sputtering apparatus will be explained according to FIG. 2. Reference numeral 11 indicates a vertical sputtering apparatus.

Reference numeral 12 denotes a flat target, at least the surface of which is made of ITO. 13 is a high frequency power source, 15, 16, and 17 are a vacuum pump, an argon gas cylinder, and a leak valve, each connected to a sputtering device, and a flow rate pipe 18 is connected to the argon gas cylinder 16.

To form the transparent conductive film 8 on the transparent parts 2 and 7 of the instrument panel 1, the transparent parts 2 and 7 are temporarily attached to the support plate 14 so that their back surfaces are exposed, and then the inside of the sputtering device 11 is evacuated. The pressure is reduced to approximately 2.0×10 −2 Torr using the pump 15 .

Next, open the cylinder 16 and check the inside of the device 11 at 8.0×10 T.
Maintain an argon gas atmosphere of about 13.6 orr.
Apply 1KW of MH2 high frequency.

Then, the argon gas is dissociated into positive and negative shapes, and the argon ions accelerated in the direction of the target 12 knock out the ITO on the surface of the target 12. The ITo scatters and adheres to the back surface of the transparent portion 2.7, forming the transparent conductive film 8.

Next, the two-color molding will be explained. Each transparent part 2.7 on which the transparent conductive film 8 has been formed as described above is set in a predetermined position in the mold of an injection molding machine (not shown), and the black area around the transparent part 2.7 is By injection molding ABS resin, the light-shielding portion 9 is integrally formed with the light-transmitting portion 2°7.

After molding as described above, the transparent conductive film 8 on the back surface of the transparent parts 2, 7 is masked leaving the edge 8a. Then, the conductive paint is applied to the back surface of the instrument panel 1 to a thickness of 20 μm, and after heating and drying at 70° C. for 45 minutes, the masking material is removed to form the paint conductive film 10, completing the present embodiment.

The instrument panel 1 of this first embodiment has electrical conductivity over the entire back surface due to the transparent conductive film 8 and the paint conductive film 10 that are electrically conductive to each other.

According to experiments, data was obtained that a remarkable electromagnetic shielding effect appears when the average surface resistance of the entire instrument panel 1 is 1 to 20 cm or less (of course, even if it is 20 cm or more, a certain electromagnetic shielding effect appears). . In this embodiment, since the surface resistance of the transparent conductive film 8 is extremely low at 5×1 O''Ωcm, the surface resistance of the entire instrument panel 1 is
It is approximately 1 Ωc'm, dominated by a surface resistance of 0, and exhibits a practically sufficient electromagnetic shielding effect.

Therefore, if a speedometer, warning device, etc. are installed inside the instrument panel 1, the CP
The electric circuit consisting of the U1 memory IC, clock IC, and other electronic components is shielded and protected from electromagnetic waves outside the instrument panel 1, thereby preventing malfunctions. It also prevents electromagnetic waves generated from the same electric circuit from being radiated outside the instrument panel 1, thereby preventing other external devices (for example, a microcomputer built into the steering wheel pad, etc.) from malfunctioning. Nor.

To explain, this embodiment differs from the □ first embodiment only in that a transparent conductive film 8 and a paint conductive film 16 are provided on the front surface of the light-transmitting portions 2 and 7 and on the front surface of the light-shielding portion 9, respectively. There is. ' Therefore, the second embodiment has the same effects and effects as the first embodiment, and the color type of the conductive paint is arbitrarily determined and the light-shielding portion 96 is
It can also be used as a colored coating.

Next, a third embodiment of the present invention will be described with reference to FIG. 5. In this embodiment, each transparent portion 2,
7 to the light-shielding portion 9, and the paint conductive film 10.
is placed in front of the light-shielding part 9, and then attached to the light-transmitting part 2.
7 is different from the first embodiment in that it is electrically connected to the transparent conductive film 8 on the back surface. That is, the light-shielding portion 9 is first molded independently, and a fitting portion 95 that is folded back in five steps toward the back side is formed at a location where the light-transmitting portion accommodates 2.7 gates. and,
Paint conductive film 101. It is formed on the front surface of the t' light-shielding portion 9 so as to curve around the insertion portion 9a. Transparent conductor 10 - The transparent part 2.7 with the electrical film 8 formed on the back side is the fitted part 9a
The transparent conductive film 8 and the paint conductive film 10 are electrically connected to each other.

Therefore, this third embodiment also has the same effects as the first embodiment and the second embodiment.

Note that, compared to the second embodiment, the transparent conductive film 8 is located on the back surface side of the first embodiment and the third embodiment, so that the protection thereof is excellent.

Next, a fourth embodiment of the present invention will be described in accordance with FIG. This embodiment differs from the third embodiment in that it is provided.

Therefore, this embodiment also has the same effects as the first embodiment.

It should be noted that the present invention is not limited to the configurations of each of the embodiments described above, and can be embodied as follows, for example.

(1) As a material for the transparent conductive film 8, various metal oxides having conductivity and transparency, such as tin oxide, indium oxide, zinc oxide, titanium oxide, and aluminum oxide, can be used in addition to the above-mentioned 1TO.

The thickness of the transparent conductive film 8 is not particularly limited unless the surface resistance is particularly high (for example, 20 cm or more).

In the case of ITO, the surface resistance was measured while increasing or decreasing its thickness in the range of 800 to 12000, and it was found to be constant at about 5 x 10' Ωcm regardless of the film thickness. Further, the transparent conductive film 8 may be formed by a vacuum evaporation method, an ion blating method, etc. other than sputtering.

(2) As the conductive paint, acrylic, epoxy, polyester, or other paints containing various conductive powders such as nickel powder, copper powder, silver powder, or carbon black can be used. The thickness of the paint conductive II*10 is not limited as long as the surface resistance does not become particularly high. Since the surface resistance varies depending on the type of conductive paint, the degree of coating, etc., the thickness of the conductive paint film 1O cannot be determined in part. −
As an example, the thickness of the paint conductive film 1O of the above example is 10 μm.
m, the surface resistance was approximately 1.5 Ωcm.

(3) Various synthetic resin materials can be used for the light-transmitting parts 2, 7 and the light-shielding part 9, and the method of joining them is not limited.

(4) In addition to the instrument panel 1 of an automobile, it can be embodied in various resin molded products such as cases and panels of various computers, word processors, televisions and audio equipment with built-in microcomputers.

(5) The transparent conductive film 8 may be formed on both sides of the transparent parts 2 and 7. The same applies to the paint conductive film 10.

Effects As detailed above, the present invention provides a resin molded product consisting of a light-transmitting part and a light-shielding part, in which a transparent conductive film made of a metal oxide is formed on at least one side of the light-transmitting part, and
By forming a paint conductive film made of a conductive paint on at least one side of the light-shielding part and making the transparent conductive film electrically conductive with the paint conductive film, the entire conductivity can be increased without impairing the transparency of the transparent part. This has an excellent effect in that it can sufficiently block electromagnetic waves and prevent malfunctions of electrical circuits such as microcomputers installed inside or outside.

[Brief explanation of drawings]

FIG. 1 is a front view of the first embodiment embodying the present invention, and FIG.
The figure is a schematic sectional view showing a part of the manufacturing method (sputtering), FIG. 3 is a sectional view of the main part, and FIGS. 4, 5, and 6 are the second and third embodiments of the present invention, respectively. FIG. 4 is a sectional view of a main part of a fourth embodiment. Instrument panel 1, light-transmitting parts 2, 7, transparent conductive film 8, light-shielding part 9, paint conductive film 10° Patent applicant Toyoda Gosei Co., Ltd. Representative Patent attorney On 1) Hiroshi Nobu 14- Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. In a resin molded product (1) consisting of a light-transmitting part (2, 7) and a light-shielding part (9), at least one side of the light-transmitting part (2.7) is transparent made of a metal oxide. In addition to forming a conductive film (8), a paint conductive film (1O) made of a conductive paint is formed on at least one side of the light-shielding portion (9), and a transparent conductive film (
8) and a paint conductive film (10) are electrically connected to each other. 2. The resin molded article according to claim 1, wherein the transparent conductive film (8) is formed by sputtering. 3. A transparent conductive film (8) is formed on one side of the light-transmitting part (2, 7), and a light-blocking part (9) is formed on the light-transmitting part (2, 7).
2-color molding, and a paint conductive film (1O) is formed on one side of the light-shielding portion (9) on the same side as the transparent conductive film (8), or The resin molded product according to item 2. 4. Transparent conductive film on one side of the transparent part (2, 7)! (8)
A light-transmitting part (9a) is formed in the light-shielding part (9), a paint conductive film (10) is formed on one side opposite to the transparent conductive film (8), and a light-transmitting part (9a) is provided in the light-shielding part (9). Part (2
, 7> is fitted.
2. Resin molded product according to item 2 or item 2.