JPS63283933A - Laminated sheet for shielding - Google Patents

Abstract

PURPOSE:To make processability good and to obtain excellent electromagnetic wave shielding property, sound shielding property and radiation shielding property, by laminating successively a self-adhesive layer and a release sheet layer on a lead alloy layer having a rough surface formed by means of an emboss processing or a cast molding. CONSTITUTION:As a lead alloy layer 1, a lead alloy sheet having a rough surface formed by an emboss processing or a cast molding is used. As a self-adhesive used for forming a self-adhesive layer 2, a composition whose main components are natural rubber, butadiene-styrene copolymerized rubber and so on, and if necessary, blended with a softening agent such as rosin, rosin ester and so on, a filler, a pigment, an aging resistant agent, a stabilizer and so on, is used. A release sheet layer 3 protects the self-adhesive layer 2 of the laminated sheet for shielding before use and as a representative one, a release paper can be cited. By laminating these sheets successively, it is possible to use it for various shielding purposes such as electromagnetic wave shielding, radiation shielding, sound shielding and so on.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a shielding laminated sheet used for purposes such as electromagnetic wave shielding, radiation shielding, and sound insulation.

Conventional technology Materials or methods for shielding electromagnetic waves include conductive paints,
Known examples include metal (zinc) thermal spraying, vacuum deposition, sputtering, and ion-blating metal plating, conductive filler-containing plastics, and metal foil. All of these have advantages and disadvantages, but metal foil is said to be the best in terms of electromagnetic wave shielding properties.

Here, as the metal foil, iron (rolled steel foil, electrolytic iron foil), copper foil (rolled copper foil, electrolytic copper foil), aluminum foil (rolled aluminum foil), etc. are used.

Problems to be Solved by the Invention However, when these metal foils are rolled foils, equipment costs and energy costs are large, and when electrolytic foils are manufactured, the manufacturing process is complicated and the manufacturing costs are high. There were disadvantages to being large.

The present inventors focused on lead, which has good workability and excellent electromagnetic wave shielding properties, sound insulation properties, and radiation shielding properties, and first produced a sheet with a mirror surface using a normal rolling method, and obtained some effects. However, as a result of various studies on further improving the shielding properties and improving the manufacturing technology, the present invention was achieved.

Means for Solving the Problems The shielding laminate sheet of the present invention comprises a lead alloy layer (1) having a rough surface formed by an embossing method or a casting method, an adhesive layer (2) and a release sheet layer ( 3) has a structure in which layers are stacked in this order.

The present invention will be explained in detail below.

(1) As the lead alloy layer (1), a lead alloy sheet having a rough surface formed by an embossing method or a casting method is used.

Since lead alone has poor strength, a lead alloy containing several percent or more of tin, zinc, or other metals is used.

Embossing can be performed in the rolling process when the lead alloy is rolled to a predetermined thickness, or in any subsequent process.

The pour molding method is a molding method in which lead alloy is poured in a molten state into a mold and then cooled.

Since the lead alloy sheet formed by the casting method itself has a rough surface, it does not require any special roughening means, and the sheet obtained by the casting method does not require the rolling method in terms of manufacturing cost. It is much more advantageous than the case.

There is no particular limit to the thickness of the lead alloy layer (1), but it is usually 0.
02~2!1 layer, especially 0.05~1mm, and even 0.02~2!1 layer.
The thickness is often about 1 to 0.8 m. If the thickness is too thin, the shielding effect will be insufficient, and if the thickness is too thick, the weight will increase and the practicality will be lost.

The adhesive used to form the adhesive layer (2) includes natural rubber, butadiene-styrene copolymer rubber, polyisobutylene, polyacrylic acid ester, polyvinyl ether,
The main component is polyisobutyl ether, and if necessary, tackifiers such as rosin, rosin ester, coumaron resin, terpene resin, hydrocarbon resin, oil-soluble phenol resin, fatty acid ester, animal and vegetable oils, wax,
A compound containing softeners such as petroleum heavy distillates, fillers, pigments, anti-aging agents, stabilizers, etc. is used.

The adhesive layer (2) includes not only a layer formed of an adhesive alone, but also a layer formed by impregnating or coating both sides of a continuous core material such as paper or plastic film with an adhesive.

Sheet 3 The release sheet layer (3) protects the adhesive layer (2) of the shielding laminated sheet before use, and typically includes release paper (i.e., kraft paper, glassine paper, parchment paper, etc.). In addition to release paper, non-woven fabrics, foamed or unfoamed plastic films, etc. that have been subjected to release treatment. is also used in the same way.

The method for manufacturing the laminated sheet for shielding pulleys is as follows: 1. An adhesive layer (2) is provided on the back side of the sheet-shaped lead alloy layer (1), and a release sheet layer (2) is provided to cover the adhesive layer (2). 3) method of coating, ■ providing an adhesive layer (2) on the release sheet layer (3);
A sheet-like lead alloy layer (1) is placed on top of the adhesive layer (2).
A method of stacking and crimping so that the back sides of the two are in contact with the adhesive layer (2), ■ A double-sided adhesive sheet-shaped adhesive is placed between the sheet-shaped lead alloy layer (1) and the release sheet layer (3). layer(
2) method of crimp-bonding with interposition, etc. can be adopted.

After the laminated sheet is manufactured, it is cut into predetermined dimensions and used as a product. In this case, it can also be cut into thin strips to form a tape.

The laminated sheet for shielding of the present invention can be used for various shielding purposes, including electromagnetic wave (including X-ray) shielding, radiation shielding, and sound insulation.

Function Lead alloy layer (1) / Adhesive layer (2) / Release sheet layer (3)
In the shielding laminated sheet of the present invention having the following structure, the lead alloy layer (1) has a shielding effect, the adhesive layer (2) has an adhesion effect to the object, and the release sheet layer (3) has an adhesive effect during the distribution or storage process. The protective effect of the agent layer (2) is shown below.

When using a laminated sheet, cut the laminated sheet to an appropriate size, peel off the release sheet layer (3), and stick it to the object using the adhesive force of the adhesive layer (2). Just that is enough.

For example, if the object is a housing with a window for electronic equipment, cut out the window before or after pasting.
If the object is a cord, cable, etc., wrap it around the tape-like laminated sheet so that the edge ends are slightly overlapped.

Such attachment prevents leakage of electromagnetic waves, radiation, noise, etc. emitted from the device itself, or conversely, prevents the influence of electromagnetic waves, radiation, noise, etc. emitted from others.

EXAMPLES Next, the shielding laminated sheet of the present invention will be further explained with reference to Examples.

Example 1 FIG. 1 is a sectional view showing an example of the shielding laminated sheet of the present invention, in which (1) is a lead alloy layer, (2) is an adhesive layer, (
3) is a release sheet layer.

Pour the molten lead alloy into a wooden frame and cool it to room temperature to form a wide sheet-like lead alloy layer (1) with a thickness of 0.3 mm.
I got it. The back surface of this lead alloy layer (1) was flat,
The surface had a rough surface.

In addition, a release sheet layer (3) was prepared, which was made of a release paper whose surface was treated with silicone on the surface of kraft paper anchor-coated with polyvinyl alcohol.

The back side of the above-mentioned lead alloy layer (1) and the above-mentioned release sheet layer (
Between 3), add a commercially available double-sided adhesive sheet-like adhesive layer (2)
A laminate sheet having a three-layer structure of lead alloy layer (1)/adhesive layer (2)/release sheet layer (3) was produced by pressing with a rubber roll.

Peel off from this laminated sheet)! (3) was peeled off and used as a shielding material for measurement.

Two 50Ω cables attached to a spectrum analyzer with a tracking generator were placed 1 cm apart from each other, so that the above-mentioned shielding material could be set between the two cables.

The state without the shielding material was set as a through state and normalized to the reference line. Next, the shielding material was inserted between the two cables, and the amount of attenuation from the reference line was measured, which was taken as the amount of shielding effect.

The measurement location, measurement equipment, and measurement conditions are shown below.

Target 1: Shiga Prefectural Industrial Technology Center Electromagnetic Shielding Room I-E 1 Spectrum Analyzer manufactured by Atopan Test Co., Ltd. TR4173 Shield material evaluator (for near field) manufactured by Atopan Test Co., Ltd. TR17301 Ezashi 1 Frequency range: 1 -11-1O0 Reference level: O or 20dB Layer display line: 0 or 20dB Resolution bandwidth: IKHz Video bandwidth = 300 or 30H2 sweep time: 1.
0sec Input attenuator: OdB The electromagnetic shielding performance measurement results are shown in solid line in Figure 2.

FIG. 2(a) shows the electric field shielding effect characteristics, and FIG. 2(b) shows the magnetic field shielding effect characteristics.

Comparative Example 1 A laminate sheet was prepared and the electromagnetic wave shielding properties were measured in the same manner as in Example 1, except that a lead alloy sheet having mirror surfaces on both sides with a thickness of 0.3 layers was formed by a rolling method. The results are shown by dotted lines in Figures 2 (a) and (b).

Example 2 An embossing roll was used as the last rolling roll in the rolling method to obtain a lead alloy sheet having a thickness of 0.51mm and having one side embossed.

This lead alloy sheet was used as the lead alloy layer (1), and an adhesive layer (2) in the form of a commercially available double-sided adhesive sheet was interposed between the non-embossed side and the release sheet layer (release paper) (3). Press with a rubber roll to form lead alloy layer (1)/adhesive layer (2)/
A laminated sheet having a three-layer structure including a release sheet layer (3) was produced.

The release sheet layer (3) was peeled off from this laminated sheet to provide a shielding material for measurement, and the laminated sheet was prepared and the electromagnetic wave shielding properties were measured in the same manner as in Example 1.

The results are shown as solid lines in FIG. 3. FIG. 3(a) shows the electric field shielding effect characteristics, and FIG. 3(b) shows the magnetic field shielding effect characteristics.

Comparative Example 2 A laminate sheet was prepared and the electromagnetic wave shielding properties were measured in the same manner as in Example 2, except that a lead alloy sheet having a mirror surface on both sides and having a thickness of 0.5 mm was formed by a rolling method. The results are shown by dotted lines in FIGS. 3(a) and 3(b).

Effects of the Invention The shielding laminated sheet of the present invention can be easily attached to an object by simply peeling off the release sheet layer (3) and pasting it on the object using the adhesive force of the adhesive layer (2). It is easy to cut and cut out with a cutter or scissors regardless of whether it is pasted or not, and it is also easy to bend, so it has good workability when shielding objects. If necessary, multiple layers can be applied.

By simply attaching it to an object, it is possible to reliably prevent the leakage of electromagnetic waves, radiation, noise, etc. emitted from the object, or conversely, the influence of electromagnetic waves, radiation, noise, etc. emitted from other sources.

Furthermore, since the lead alloy layer (1) has a rough surface, its shielding properties are further improved compared to the case where a lead alloy sheet formed by a normal rolling method and having a mirror surface is used.

Furthermore, when the lead alloy layer (1) is formed by a casting method, it is much more advantageous in terms of manufacturing cost than when a lead alloy sheet is obtained by a rolling method.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of the shielding laminated sheet of the present invention. Figures 2 (a) and (b) show Example 1 and Control Example 1.
3 is a graph showing the electromagnetic wave shielding effect characteristics of an electric field and a magnetic field in FIG. Figures 3 (a) and (b) show Example 2 and Control Example 2.
3 is a graph showing the electromagnetic wave shielding effect characteristics of an electric field and a magnetic field in FIG. (1)...Lead alloy layer, (2)...Adhesive layer, (3)
...Release sheet layer Figure 1 Frequency (MHz) Frequency (MHz) Figure 3 (A. Frequency (MHz)

Claims (1)

[Claims] 1. A shielding laminated sheet having a structure in which a lead alloy layer (1) having a rough surface formed by an embossing method or a casting method, an adhesive layer (2), and a release sheet layer (3) are laminated in this order.