JPH03234975A - Gasket and its manufacture - Google Patents

Abstract

PURPOSE:To give an excellent productivity and a secure EMI countermeasure aptitude by covering an elastic long-size core with a metallic knetted mesh, through an adhesive layer formed at the peripheral surface of the core. CONSTITUTION:An adhesive is coated at the peripheral surface of an elastic long-size rubber 1, and dried when necessary to form an unhardened or imperfectly hardened adhesive layer (process A). After the process A is finished, the long size core 1 with adhesive layer is made as a core, metal wire lines are knitted, and the long size core 1 with the adhesive layer is covered with a metallic knitted mesh 3 (process B). And by promoting the hardening reaction of the adhesive layer by applying a hardening promoting process to the coverage body after the process B is finished, the long size core 1 and the metallic knitted mesh 3 are incorporated through the adhesive layer 2(process C). The series of processes can be carried out continuously. In this case, since the adhesive layer 2 does not appear to the upper surface of the mesh 3, the gasket has an electric continuety along the whole length.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a gasket for EMI countermeasures. It also relates to a method of manufacturing such a gasket.

BACKGROUND OF THE INVENTION A gasket intended to be interposed between the main body and the lid of a housing for an electronic device is not only required to have I71+ strength and resilience, but also to be suitable for EMI countermeasures.

One of the preferred EMI countermeasure gaskets is a gasket in which a long core made of an elastic material such as synthetic rubber is covered with a metal knitted mesh (for example, " Table 2 on page 60 of ``Noise Countermeasures, Shielding Materials and Methods 1 Published by Information Research Committee Co., Ltd.''
20). In order to cover a long core with a metal stockinette mesh, a method is adopted in which the core is used as a core and metal filaments are knitted around it.

Japanese Utility Model Application Publication No. 63-174496 discloses that ``In a backing material in which an elastic core material is inserted and arranged inside a cylindrical metal mesh, a polymer coating layer is formed from the outside of the metal mesh, and the polymer "An electromagnetic shielding packing material having a structure in which at least a part of the coating layer adhering to the metal mesh is removed until the metal mesh is exposed."

The problem that Isuzu 1 aims to solve Gaskets, which have a long core made of synthetic rubber or the like covered with a metal stockinette mesh, are suitable for EMI countermeasures, but when cut to the desired length for use. Debris from stockinette knitting may be generated and cause short circuits in electronic circuits.

Therefore, the mesh is fixed to the core by covering the cut part with resin, rubber adhesive, solder, etc., but this work is cumbersome and it is difficult to completely prevent the generation of chips. There was a problem.

The idea disclosed in Japanese Utility Model Application Publication No. 63-174496 is intended to solve this problem, but since the polymer coating layer formed on the metal mesh is removed until the metal mesh is exposed, The manufacturing process becomes complicated, and if the removal is incomplete, there is a risk that conductivity will be incomplete when used as a backing material.

In view of the above circumstances, the present invention has been made for the purpose of providing a gasket that is highly productive and has reliable EMI countermeasure suitability.

The one-stage gasket of the present invention to solve the problem has a long core (1) having elasticity.
are coated and integrated with a metal stockinette mesh (3) via an adhesive layer (2) formed on the circumferential surface thereof.

As the elastic elongated core (1), a elongated material made of an elastic material such as polyurethane, silicone, neoprene rubber, synthetic rubber such as EPDM, or elastomer is used.

The shape can be arbitrary such as circular, rectangular, polygonal, solid,
It may be hollow.

The metal stockinette mesh (3) is obtained by stockinette knitting metal filaments. A metal foil wire, a metal wire, or the like is used as the metal filament, and a metal foil wire is particularly advantageous because it is easy to bond. Various materials can be selected for the stockinette mesh (3), including Monel, Katzuku-weld, aluminum, and tin-plated copper.

There is no particular limitation on the type of adhesive in the adhesive layer (2), and examples include thermosetting (including vulcanization) adhesives, active energy ray-curing adhesives, moisture-curing adhesives, and room-temperature-curing adhesives. , catalytic curing adhesives, etc. can be used. In terms of types of 81 resins, rubber-based, urethane-based, polyester-based, epoxy-based, acrylic-based, phenol resin-based, etc. can be exemplified. When neorene-based rubber is used as the long core (1), it is also advantageous to use an adhesive that is the same type as the material of the long core (1), such as using a neorene-based adhesive. .

Since the gasket of the present invention has elasticity, it may take time and effort to install it at a target site (for example, a site without a groove or a bent portion) when applying it to an object. Therefore, in such a case, it is preferable to provide an adhesive layer (4) in the length direction on a part of the circumferential surface of the gasket, and further laminate a releasable sheet (5) on the adhesive layer (4). . In use, the releasable sheet (5) may be peeled off and then adhered to the target area of the object. Note that the above-mentioned adhesive layer (4) can also be provided discontinuously (for example, in spots at regular intervals) in the length direction of the elongated core (+).

When providing an adhesive layer (4), the presence of a core (substrate) may adversely affect conductivity, so it is desirable to configure the layer with only the adhesive. If the width is too wide, it may have a negative effect on conductivity. For example, if the gasket is rectangular, the adhesive layer (
4) is desirable.

The gasket of the present invention having the above configuration is preferably manufactured according to Step A, Step B, and Step C described below.

Step A is by applying an adhesive to the circumferential surface of the elastic long core (1) and drying it if necessary.
This is a step of forming an uncured or incompletely cured adhesive layer (2a).

In step B, metal filaments are knitted using the elongated core (1) with the adhesive layer (2a) as a core after the completion of the step A, thereby forming the elongated core with the adhesive layer (2a) ( This is a step of covering 1) with a metal stockinette mesh (3).

In step C, the coating after the completion of step B is subjected to a curing accelerating process to advance the curing reaction of the adhesive layer (2a), thereby forming the elongated core (1) and the metal stockinette mesh (
3) and are integrated through the adhesive layer (2). Measures to accelerate curing include heating,
Treatments such as irradiation with active energy rays, application of moisture, leaving, and contact treatment with catalysts are employed.

By performing such steps, the gasket of the present invention can be manufactured with high productivity.

Function and Effects of the Invention In the gasket of the present invention, since the long core (1) having elasticity is covered with the metal stockinette mesh (3), it has elasticity and restorability as well as excellent elasticity. It has EMI countermeasure suitability.

In addition, the elongated core (1) and the metal stockinette mesh (3) are connected to the contact agent layer (2) formed on the circumferential surface of the elongated core (1).
), there is no risk of generating chips from the stockinette mesh (3) even if it is cut to the desired length during use.

Moreover, since the adhesive layer (2) does not appear on the upper surface of the metal stockinette mesh (3), conductivity is not impaired over the entire length of the gasket, and the original metal of the stockinette mesh (3) is maintained. performance.

If the gasket of the present invention is manufactured according to the above steps A, B, and C, it can be mass-produced without requiring post-processing.
And you can always get products of constant quality.

Example Next, the present invention will be further explained with reference to Examples.

Example 1 FIG. 1 is a cut end view schematically showing an example of the gasket of the present invention, in which (1) is a long core, (2) is an adhesive layer, and (3) is a metal stockinette mesh. It is.

For example, the long core (1) with elasticity has a cross section of 3
A long neoprene rubber sponge having a rectangular shape of mm×5 am (other cross-sectional shapes or other elastic materials can also be used) was prepared.

After applying a neoprene rubber adhesive solution (other adhesives can also be used) on the circumferential surface of the elongated core (1),
It was dried at 80 to 100°C to volatilize most of the solvent components, forming a substantially uncured (unvulcanized) adhesive layer (2a). (Process A) After completion of Step 8A, the long core (1) with the adhesive layer (2a) is used as the core, and the metal foil wire (other metal wires can also be used) is wired at a speed of 3 shoulders/in. By stockinette knitting, the long core (1) with adhesive layer (2a) was covered with a metal stockinette mesh (3). (Step B) The coated body after Step B is passed through a heating furnace and cured for a short time at a temperature of 100 to 120°C to form an adhesive layer (2a).
A curing reaction (vulcanization reaction) was allowed to proceed, and the long core and the metal stockinette mesh (3) were integrated via the adhesive layer (2). (Step C) These series of steps was performed continuously.

As a result, the gasket shown in No. ti was obtained, which was cut into a predetermined product length and placed in a heating furnace for complete vulcanization.

The adhesive layer (2) is made of metal stockinette mesh (3)
It did not appear on the surface at all.

The product gasket thus obtained was cut to the length for use, but no chips of the stockinette mesh (3) were generated.

Example 2 FIG. 2 is a cut end view schematically showing another example of the gasket of the present invention, in which (1) is a long core, (2) is an adhesive layer, and (3) is a metal knitted fabric. The knitted mesh, (4) is an adhesive layer, and (5) is a releasable sheet.

An acrylic adhesive solution was applied to one peripheral surface of the rectangular gasket obtained in Example 1 so that the width was narrower than the width of the surface, and dried to form an adhesive layer (4). A releasable sheet (5) made of silicone-treated kraft paper was laminated on the adhesive layer (4).

As a result, a gasket with an adhesive layer (marked with 0) as shown in FIG. 2 was obtained.

Embodiment 3 FIG. 3 is an apparatus diagram showing an example of the gasket manufacturing method of the present invention, and FIG. 4 is a sectional view showing the liquid tank (8).

In FIGS. 3 and 4, (1) is a long core, (2) is an adhesive layer, and (3) is a metal stockinette mesh.

In this example, a silicone tube with an outer diameter of 2.0 mm and an inner diameter of 1.6 mm is used as the long core (1), and a silicone adhesive is used as the adhesive in the adhesive layer (2). As the metal stockinette mesh (3), a Monel stockinette mesh with a wire diameter of 0.08 mm is used.

(6) is a supply reel, on which the long core (1) is wound. (7) is a guide roll.

(8) is a liquid tank, and (8) is a bush with a hole diameter of 2.4+ug provided through the bottom of the liquid tank (8). The liquid tank (8) contains an adhesive for forming the adhesive layer (2).

(10) is a heating furnace, but in this example, a solvent-free silicone adhesive is used as the adhesive, so the installation of this heating furnace (10) itself may be omitted or the installation may be unnecessary. However, the heating operation can be omitted.

A wire bobbin (11) is wound with a wire (3a) for forming a metal stockinette mesh (3).

(12) is a stockinette knitting machine, (13) is a cylinder,
(+4a) and (14b) are cams, and (15) is a stockinette needle.

(16) is a bush with a pore diameter of 2.5 cm.

(17) is a heating furnace, and the adhesive layer (2) is cured at 200 to 400°C while passing through the heating furnace (17).

(18) is a pair of take-up rollers.

5 to 8 are points A in FIG. 3, respectively.

Cut end view in the radial direction at point B, point 0, and point D, No. 9
The figure is a sectional view taken along line XX in FIG.

Using the apparatus shown in Fig. 3, the adhesive layer (
A product gasket was manufactured by forming 2) and covering it with a metal stockinette mesh (3). The adhesive layer (2) did not appear on the surface of the metal stockinette mesh (3) at all.

This gasket was cut to a predetermined length, but no chips of stockinette mesh (3) were generated.

Figure 1O is a partial cross-sectional view of a housing using the gasket obtained in this way, (18) is the housing, (19a
) is the main body of the housing (19), (19b) is the lid of the housing (19), (20) is the mounting screw, and (g) is the gasket.

Example 4 A neoprene rubber having a circular cross section with a diameter of 2 shoulders was used as the long core (1), a neoprene rubber adhesive solution was used as the adhesive in the adhesive layer (2), and a metal stockinette knitted mesh (3 ), a knitted monel acid mesh with a wire diameter of 0.08 mm was used, and dried in a heating furnace (10) at a temperature of 50 to 70°C, and cured for a short time at a temperature of 150°C in a heating furnace (17). Other than that, the gasket was manufactured according to the equipment diagram shown in Figure 3.

3 4 The adhesive layer (2) did not appear on the surface of the metal stockinette mesh (3), and although this gasket was cut to a predetermined length, no chips were generated from the stockinette mesh (3). There were none.

[Brief explanation of drawings]

FIG. 1 is a cut end view schematically showing an example of the gasket of the present invention. FIG. 2 is a cut end view schematically showing another example of the gasket of the present invention. FIG. 3 is an apparatus diagram showing an example of the gasket manufacturing method of the present invention, and FIG. 4 is a sectional view showing the liquid tank (8). Figures 5 to 8 are points A, B, and 0 in Figure 3, respectively.
FIG. 9 is a radial cut end view at point D and FIG. 9 is a sectional view taken along line xx in FIG. 8. FIG. 10 is a partial sectional view of a housing using the gasket/gasket of the present invention in this manner.

Claims (1)

[Claims] 1. A long elastic core (1) is covered and integrated with a metal stockinette mesh (3) via an adhesive layer (2) formed on its circumferential surface. A gasket. 2. A gasket formed by providing an adhesive layer (4) in the longitudinal direction on a part of the circumferential surface of the gasket according to claim 1, and further laminating a releasable sheet (5) on the adhesive layer (4). 3. Step A of forming an uncured or incompletely cured adhesive layer (2a) by applying an adhesive to the circumferential surface of the elastic long core (1) and further drying if necessary.
, Long core (1) with adhesive layer (2a) after completion of the step A
Step B of covering the elongated core (1) with adhesive layer (2a) with a metal stockinette mesh (3) by stockinette knitting metal filaments with the core as the core; after the completion of step B; By applying curing acceleration measures to the coating to advance the curing reaction of the adhesive layer (2a), the elongated core (1) and the metal stockinette mesh (3) are bonded together through the adhesive layer (2). A method for manufacturing a gasket, characterized by comprising the steps of integrating: C.