JPH0748593B2 - Manufacturing method of packing material for electromagnetic wave shield - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an electromagnetic wave shielding packing material which is interposed between a main body of a housing for electric / electronic equipment and a lid to perform electromagnetic wave shielding.

[Prior Art] In a housing for an electric / electronic device such as a communication device, a body and a lid having electromagnetic wave shielding properties are used, but since electromagnetic waves leak from between the body and the lid,
It is required to use a packing material having an electromagnetic wave shielding property.

Conventionally, a packing material has been manufactured by inserting and arranging an elastic core material such as a rubber tube inside a tubular metal mesh. However, since the tubular metal mesh only covers the elastic core material by simply inserting and arranging it, a When the packing material is cut to an appropriate length, the metal wire is loosened from the cut end. B) When the packing material is cut, a gap may occur between the two. C Especially when the cutting length is short, the tubular metal mesh may come off from the elastic core material, and There were problems such as the broken pieces of the mesh falling off and dropping onto the mounting electronic board to adhere to them, which could cause a short circuit.

Therefore, as disclosed in Japanese Utility Model Laid-Open No. 61-79597, there is known one manufactured by integrating a tubular metal mesh and an elastic core material. Then, the manufacturing method is such that a metal mesh is embedded in at least the electromagnetic wave receiving surface of the outer surface of the packing body made of conductive rubber, and a part of the metal mesh is exposed on the outer surface of the packing body. is there.

[Problems to be Solved by the Invention] However, in order to embed a metal mesh on the surface of the packing body and expose a part of the metal mesh on the outer surface of the packing body as in the conventional case described above, for example, After applying an adhesive or the like to the surface of the elastic core material, the elastic core material must be covered with a tubular metal mesh. This method has a disadvantage in that when the elastic core material is covered with the metal mesh, the metal mesh easily sticks to the adhesive before the metal mesh is completely covered. If they stick to each other on the way, they have to be removed and covered again each time, which takes time to finish placing them at the desired positions. Especially for long ones, the work becomes very difficult.

The present invention has been made in view of these problems, and provides a method for manufacturing a packing material for electromagnetic wave shielding, in which the work of fixing a metal mesh to a core material and exposing a part of the metal mesh is easy. It was made for the purpose.

[Means for Solving the Problems] In order to solve the above-mentioned object, the present invention provides an elastic core material inserted and arranged inside a tubular metal mesh formed by braiding metal wires, A polymer coating layer having adhesiveness with the elastic core material is formed from the outside, and at least a part of the polymer coating layer attached to the metal mesh is solidified before the polymer coating layer is solidified. And finally, the polymer coating layer is hardened to shrink the polymer coating layer, and the metal mesh is exposed on the surface of the polymer coating layer after being solidified. The manufacturing method is as the gist.

As a method for solidifying the polymer coating layer, a polymer melted by heat is applied from the outside of the metal mesh and then solidified by cooling, a polymer dissolved in a solvent is applied on the metal mesh,
There are a method of evaporating a solvent to solidify it, a method of coating a polymer on a metal mesh and then solidifying it by the action of water, heat, ultraviolet rays, contact with a curing agent, or the like.

[Operation] In the method of manufacturing the packing material of the present invention, first, the elastic core material is inserted and arranged inside the tubular metal mesh formed by braiding the metal wires. Further, the elastic core material may be inserted simultaneously with the braiding of the metal wire. Then, a polymer coating layer is provided on the outside of the tubular metal mesh around the elastic core material, and at least a part of the polymer coating layer attached to the metal mesh is solidified before it solidifies. Remove and then solidify. The metal mesh is exposed on the surface of the polymer coating layer after solidification by the removal process and the subsequent contraction due to solidification.

EXAMPLES Next, the present invention will be further described with reference to examples.

FIG. 1 shows a cut end view in the manufacturing process of the packing material of the present embodiment, and (a) shows the polymer coating layer 3
Of the polymer coating layer 3 on the metal mesh 2 of the polymer coating layer 3 of (b). FIG. 7 is a radial cross-sectional end view showing a state in which a part of the attached portion is removed. In the figure, 1 is an elastic core material, 2 is a metal mesh,
3 is a polymer coating layer. Also, FIG. 2 is shown in FIG.
FIG. 4 is an axially cut end view in FIG.

Examples of the elastic core material 1 include silicone rubber, natural rubber, styrene-butadiene rubber, butyl rubber, ethylene-propylene rubber, chloroprene rubber, nitrile rubber, urethane rubber, epichlorohydrin rubber, acrylic rubber, fluororubber, and tetrafluoroethylene resin. A molded product made of rubber, a polyolefin-based, polyester-based, polyurethane-based, polyamide-based, or other elastomer, or a nonwoven fabric or sponge is preferably used.

Since the electroconductivity is obtained by the metal mesh 2 described below, the elastic core material 1 itself does not need to have electroconductivity, but the electroconductivity may be imparted.

The shape of the elastic core material 1 is a pipe shape, a round bar shape, a rectangular columnar shape such as a square shape, a hexagonal shape, an octagonal shape, a flat shape, a V shape, a U shape,
The shape is Y-shaped, or a fibrous shape made of these materials is twisted or braided, but is often a pipe shape or a round bar shape. Further, when it is desired to increase the adhesive force between the elastic core material 1 and the metal mesh 2, a core agent made of a fiber material is preferably used.

Examples of the metal wire forming the metal mesh 2 include a metal wire made of copper, a copper alloy, a copper covered steel, aluminum, an aluminum alloy, an aluminum covered steel wire, a plated wire, or the like.

A tubular metal mesh 2 that covers the elastic core material 1 is formed by braiding the elastic core material 1 around one or more metal wires. Depending on the shape of the elastic core material 1, a die matching the shape may be used to
It is also possible to fit the braided metal mesh 2 to the elastic core material 1.

In this embodiment, an outer diameter of 6 mm as an example of the elastic core material 1,
A tubular metal mesh 2 was formed by braiding tin-plated copper wires by knitting around a silicone rubber tube having an inner diameter of 4 mm.

Then, a polymer coating layer 3 having adhesiveness with the elastic core material 1 is formed from the outside of the metal mesh 2. The application is performed by means such as dipping and spraying.
When the elastic core material 1 is a rubber-based polymer, it is desirable that the polymer coating layer 3 is also a rubber-based polymer coating layer of the same type. The polymer coating layer is more preferably flame-retardant, and for example, UL standard flame-retardant silicone rubber may be used.

In this example, the polymer coating layer 3 was uncured after being dipped in a colored curable silicone rubber liquid and then pulled up.
Was formed. Note that the coloring is for making it easier to see the adhesion state, and may or may not be actually colored.

Then, at least a part of the part of the polymer coating layer 3 attached to the metal mesh 2 is scraped while it is uncured. As the scraping method, for example, there is a method of inserting a metal hole, a ceramic hole, or a plastic hole.

In the present embodiment, when the polymer coating layer 3 is still wet and not cured, the polymer coating layer 3 is passed through a metal hole having a diameter substantially the same as the diameter of the cylindrical metal mesh 2 and adheres onto the metal mesh 2. The applied polymer coating layer 3 was scraped off by the metal holes, and the metal mesh 2 was partially exposed.

Then, after the above-mentioned scraping process, a curing means (heating, heat, ultraviolet irradiation, contact with a curing agent, etc.) suitable for the curing characteristics of the polymer coating layer 3 is taken to finally cure the polymer coating layer 3. Let The metal mesh 2 is exposed on the surface of the polymer coating layer 3 after the curing due to the shrinkage due to the above-mentioned scraping and the subsequent curing treatment.

In this example, the polymer coating layer 3 was crosslinked and cured by heating at 180 ° C. for 3 minutes, and due to shrinkage during curing,
The degree of exposure of the metal mesh 2 was further improved compared to immediately after sneaking. Visual observation revealed that the degree of exposure of the tubular metal mesh 2 was about 70%.

Of the metal mesh 2 of FIG. 1 (c), the rubber-based polymer coating layer 3 remains on the outer periphery of 2a and 2d.
In b, 2c and 2e, the polymer coating layer 3 is removed from the outer periphery thereof. Similarly, 2D of the metal mesh 2 in FIG.
In, the polymer coating layer 3 remains on its outer periphery,
In 2A, 2B and 2C, the polymer coating layer 3 is removed from the outer periphery thereof.

The packing material manufactured in this manner was cut to an appropriate length, but there was no deviation between the elastic core material 1 and the metal mesh 2, and the cut end of the metal mesh 2 was loosened. It did not occur and the scrap did not fall off.

The packing material manufactured by this manufacturing method is useful as an electromagnetic wave shielding packing material that is interposed between the main body and the lid of the housing for electric / electronic devices to be airtight. An example of its use is shown.

FIG. 3 is a cross-sectional view of a housing equipped with the packing material of this embodiment.

In FIG. 3, 4 is a main body of a control box as an example of a housing, 5 is a lid of the housing, 6 is a tightening screw, and the inner surface of the main body 4, the inner surface of the lid 5, and the facing surface of the main body 4 and the lid 5 All are made of a conductive material. 7 is a packing material.

The cut packing material 7 was attached to the housing as shown in FIG. 3, but the electromagnetic wave shield was perfect.

[Effect of the Invention] In the production method of the present invention, the elastic core material is inserted and arranged inside the tubular metal mesh, and the polymer coating layer is provided from the outside of the metal mesh. At least a part of the portion adhered on the mesh is removed before it is solidified, and finally solidified by an appropriate method. The metal mesh is exposed on the surface of the polymer coating layer after the solidification by the removal process and the subsequent contraction due to the solidification.

Therefore, when the elastic core material is inserted and arranged inside the metal mesh, there is no polymer coating layer on the surface of the elastic core material, and the insertion can be smoothly performed. Then, a part of the polymer coating layer provided from the outside of the metal mesh is removed before it hardens,
Eventually, only by solidifying, a part of the metal mesh can be exposed, and the work is very easy.

[Brief description of drawings]

FIG. 1 is a cut end view of each manufacturing process by a packing material manufacturing method according to an embodiment of the present invention.
(A) is a sectional view in a radial direction before the polymer coating layer is provided,
(B) is a radial cross-section end view after the polymer coating layer is provided,
(C) is a radial cross-section view showing the state when a part of the polymer coating layer in (B) attached to the metal mesh is scraped before it hardens and then solidified. Is. FIG. 2 is an axially cut end view in FIG. FIG. 3 is a cross-sectional view of a housing equipped with the packing material of this embodiment. 1 ... Resilient core material 2, 2a-2e, 2A-2D ... Metal mesh 3 ... Curable polymer coating layer 4 ... Body of the housing, 5 ... Lid of housing 6 ... Tightening screw, 7 ... … Packing material

Claims (1)

[Claims] 1. A polymer coating layer in which an elastic core material is inserted and arranged inside a tubular metal mesh formed by braiding metal wires, and which has adhesiveness with the elastic core material from the outside of the metal mesh. Forming at least part of the polymer coating layer adhering to the metal mesh before the polymer coating layer hardens, and finally solidifying the polymer coating layer. The metal mesh is exposed on the surface of the polymer coating layer after being contracted and solidified by the method for producing an electromagnetic wave shielding packing material.