JPS5863198A - Rubber product for shielding microwave - 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] Recently, the development of electronics has been remarkable, and micro devices are increasingly being used in many devices and electrical products, and advanced functions are being added to these devices. It contains an integrated circuit and generates microwave noise. Furthermore, as these electronic elements have become smaller and faster, the current they use has become weaker, and as a result, the intensity and frequency of noise entering from the outside has become close to that of signal radio waves. This causes malfunctions. Therefore, electronic devices are not allowed to emit noise to the outside or pick up noise from the outside, so microwaves are used for computers and other information devices surrounding them, office equipment, electronic medical equipment, automobiles, etc. Recently, there has been a particular demand for countermeasures against microwave noise in a wide range of fields. In response to this need, the present invention provides an inexpensive microwave device with excellent microwave effects.

The conventionally known method is as shown in Publication No. 44-8394, where the frequency of the irradiated microwave is approximately 9X109H.
In Z, the amount of backside reduction is 21.8 to 26.9 digihels, that is ■
(2) The effectiveness was less than 27% and it could not be put to practical use. In addition, the inventions of Japanese Patent Application Laid-open No. 47-83357 and Japanese Patent Publication No. 54-36441, both of which were invented by the author earlier, showed a reduction amount of 90 decihers or more when irradiated with microwaves of 1×1010 Hz, and the microwave ■■ effect was 90%. The above is excellent, but since the conductive material of this product uses silver powder, after the oil shock, the price of silver skyrocketed in reaction to the oil shock, jumping 2 to 3 times, resulting in an extremely high material cost. The cost has become significantly higher. No matter how effective the product is, if it is too expensive, the field of demand will be limited and it will become impractical, leading to a decline in demand. To improve this economical defect, the amount of expensive silver powder, which is a conductive material, should be reduced by 1/2.
If the weight can be reduced by 2, or 1/5, or even 1/10, it is inevitable that the cost will be reduced to 1/2, 1/5, or 1/10. However, since the surface area of the silver powder is contacted and connected by the rubber medium to form a conductive mechanism, and it is electrically a conductor similar to metal, it has excellent microwave effects. The conductive mechanism is 102 cm, 108 cm, 1015 cm,
The electrical resistance increases and it finally becomes an insulator, and microwave ■
■Function disappears. Therefore, the amount (weight) of silver must be reduced without destroying the conductive mechanism. As mentioned above, the conductive mechanism is constituted by the surface area of the silver particles contacting each other, so by reducing the amount of silver inside the constituent silver particles, which is not related to this surface area contact, it is possible to reduce the cost. This goal can be achieved by constructing a conductive mechanism using hollow, strong silver particles like soap bubbles as a medium and the same volume using rubber as a medium.
The weight can be reduced to 1/2, 1/5, or 1/10 if necessary. However, this is a technical idea, and in reality, hollow silver particles with grain sizes of 50 μm or less are not commercially available, so the present invention uses silver coating on the surface of hollow glass spheres with grain size of 44 μm or less. Add 150 to 250 parts (by weight) of the conductive particles to 100 parts (by weight) of methyl vinyl silicone rubber using a mixing roll, and then add an appropriate amount of crosslinking agent and a small amount of coloring agent to mix well and homogenize. After being dispersed in
It provides a superconducting rubber that is less than ■ cm and highly effective in microwave ■■.

Next, examples will be explained.

The example is silicone rubber KE-530U (Shin-Etsu Chemical Co., Ltd.
Product name Silver coated glass beads S-3000S2 (manufactured by Toshiba Balloteini KK) 150 parts (parts by weight) made of silver coated glass beads coated with a silver film on the surface of a 30μ hollow glass sphere ) and 0.8 parts (parts by weight) of the crosslinking agent dicromyl peroxide. Ordinary colorant Bengara 2
(parts by weight) etc. are mixed with a mixing roll and dispersed uniformly, then rolled out to any size using a pressure roll, inserted into a mold of any shape, and vulcanized by heating and pressurizing with a vulcanizer. The product taken out from the mold has an electrical resistance of 2.7 x 10-1cm and physical properties of a specific gravity of 1.74, hardness of 53 degrees, elasticity of 53%, and elongation of 250%.
, and the tensile strength was 40 kg/cm2.

Example 2 is an example in which the types of raw materials and the blending ratio are exactly the same, but the type of conductive material is different.

Silicone rubber KE-530U (manufactured by Shin-Etsu Chemical KK) 1
00 parts (by weight), 150 parts of silver-coated glass beads S-5000S2 (manufactured by Toshiba Ballotini KK) with an average particle diameter of 15μ, 0.8 parts (by weight) of dicrosilver oxide as a crosslinking agent, and Bengara or Ultramarine 2 colorant. (parts by weight) etc. are mixed with a mixing roll, dispersed uniformly, rolled out to any size with a rolling roll, inserted into a mold of any shape, and vulcanized by heating and pressurizing with a vulcanizer. The product taken out has an electrical resistance of 2
．． Physical properties are 55% elasticity and specific gravity 1.7 at 2 x 10-1 cm.
5. Hard wave 50 degrees, elongation 300%, tensile strength 43 kg/cm
In Example 3, 100 parts (by weight) of silicone rubber KE-530U (manufactured by Shin-Etsu Chemical KK) were coated with silver-coated glass beads S3000S2 (manufactured by Toshiba Ballotini KK).
200 parts (parts by weight), 0.8 parts (parts by weight) of cross-linking agent dicromyl peroxide, 2 parts (parts by weight) of coloring agent Bengara or Ultramarine, etc. are mixed with a mixing roll and dispersed uniformly, and then optionally The product is rolled out with a rolling roll, inserted into a mold of any shape, vulcanized by pressure and heating in a vulcanizer, and then taken out from the mold.The product has an electrical resistance of 2.8 x 10-2 cm and a specific gravity. is 1.8, hardness 57 degrees, elasticity 45%, elongation 250%,
The tensile strength was 40 kg/cm2.

In Example 4, the type of raw rubber was KE-951U (manufactured by Shin-Etsu Chemical KK), and the compounding ratio, mixing, rolling, crosslinking,
Since the above is exactly the same, I will omit the description. The electrical resistance of the product is 4.5 x 10-2 cm, and the physical property is specific gravity 1.8.
Hardness 68 degrees Elasticity 35% Elongation 200% Tensile strength 35kg
/cm2.

In Example 5, the type of raw rubber is KE-742U (manufactured by Shin-Etsu Chemical Co., Ltd.), and the other steps are exactly the same as in Example 3, such as the compounding ratio, mixing rolling, and crosslinking, so the electrical resistance of the omitted products is as follows. 6.5X10-2cm, specific gravity 1.8,
Elasticity: 40% elongation, 200% tensile strength: 25kg/cm2. Example 6 is silicone rubber KE-530U (manufactured by Shin-Etsu Chemical KK) with silver coated glass beads S-30.
00S2 (manufactured by Toshiba Baloini KK) 250 parts (parts by weight)
, crosslinking agent dicromyl peroxide 0.8 parts (parts by weight)
, 2 parts (by weight) of Bengara or Ultramarine coloring agent is mixed with a mixing roll, dispersed uniformly, cut out into a sheet of any size with a rolling roll, inserted into a mold of any shape, and placed in a vulcanizer. After being vulcanized by heating under pressure, the product was removed from the mold and its physical properties and electrical resistance were measured. The electrical resistance was 8×10 −3 cm, the specific gravity was 1.95, the hardness was 67, the elasticity was 30%, the elongation was 150%, and the tensile strength was 20 kg/cm 2 . Next, Examples 1 to 6 are shown in Table 1.

▲The electrical resistance value is measured using the Wheatstone bridge method.

▲▲The physical property test values were determined using the test method of JIS-K6301.

▲▲▲Microwave irradiation test has a frequency of 1,0000MHz
Measure with.

▲▲▲▲Silicone rubber KE-530U, KE-742U
, KE-951U was manufactured by Shin-Etsu Chemical KK.

▲▲▲▲▲The conductive material silver-coated glass beads were manufactured by Toshiba Balloini KK.

▲▲▲▲▲▲ The color tone can be determined freely using any dye. Next, the performance of the conventional method and the method of the present invention is shown in FIG.

▲ For the microwave irradiation test and microwave attenuation test, the sample was attached to a rectangular waveguide flange for bands specified in JIS-C-6605 and JIS-C-6606, respectively, at 8.2G.
Microwaves of Hz and 10 GHz were respectively irradiated.

▲▲The cost is 1
This is a comparison of other things when it is set to 00.

The product of the present invention is made of non-polar material, so it is 10G
Even when exposed to microwave irradiation at a frequency of Hz, it does not deteriorate due to heat generation and has a long service life.

Also, since the composition of the mechanism is rubber containing silver-coated glass hollow beads, it is rich in elasticity, flexibility and flexibility peculiar to rubber, and has an excellent sealing effect.

Furthermore, the amount of silver, which is a conductive material, used can be drastically reduced, and the specific gravity of conductive rubber, which is a constituent material, is reduced to approximately 1/2, resulting in a significant cost reduction to 1/4 of that of conventional products.
This is due to the following low ■.

Incidentally, the microwave ■■ effect is also over 90 decibels as shown by the amount of attenuation, which is comparable to that of JP-A No. 49-39037.

In this way, the present invention has made it possible to provide economically valuable products without damaging the microwave effects.

Patent applicant: Nobu Kiyomizu

Claims (1)

[Claims] 100 parts (parts by weight) of methyl vinyl-based silicone rubber are uniformly mixed with 150 to 250 parts (parts by weight) of particles made of hollow glass beads with a grain size of 40μ or less coated with silver, and then an appropriate amount of a crosslinking agent and A rubber product characterized by having a specific gravity of 2 or less and an electrical resistance of 5 x 10-1cm or less after adding a coloring agent and uniformly dispersing it, inserting it into a mold of any shape and pressurizing and vulcanizing it. .