JPH0346903Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a flexible sheet that can effectively prevent electrical disturbances. [Prior Art] Conventionally, flexible sheets made of various synthetic resins or synthetic or natural rubber have been used as equipment covers and other flexible covering materials, and many of these are reinforced with fiber materials. However, these sheets are electrically insulating in nature, typically 10 ¹⁰ to 10 ¹⁷ Ω cm,
Many have specific resistance values of 10 ¹² Ω·cm or more. Therefore, these sheets generate static electricity when rubbed, resulting in poor handling properties. Also, for example,
When these sheets are used as covers for wind pipes in coal mines or on tankers, they are used to prevent static electricity on the surface, but if the resistance is lowered more than necessary, it may cause leakage depending on the application Due to the dangers involved, and due to the unique requirements of each application, they were individually made and used as antistatic sheets or conductive sheets. [Problem that the invention aims to solve] However, as the development of electrical equipment progresses in recent years, the occurrence of electrical interference and electromagnetic interference has become a serious problem.
In addition, there is a need to make the antistatic function of antistatic sheets permanent and highly reliable, so there is a demand for the development of drastic measures to solve the electrical problems with such sheets. . The present invention was completed as a result of studies to satisfy the above requirements, and is capable of suppressing the generation of static electricity and preventing static electricity interference.Moreover, the effect is permanent, and it also prevents radio interference. It is an object of the present invention to provide a flexible sheet that can effectively suppress the effects of oxidation, and can respond extremely favorably to various situations. [Means for Solving the Problems] The flexible sheet for preventing electrical disturbances of the present invention includes at least one layer containing a flexible resin or rubber material as a matrix component and having a specific resistance value of 10 ³ Ω·cm or less. A flexible conductive sheet part, a flexible resin or rubber material as a matrix component, a specific resistance value of 10 ⁵ to ^{10 8} Ωcm, and laminated with the conductive sheet part, at least It is characterized by comprising one layer of a flexible semiconductive sheet part, and a flexible reinforcing sheet part made of a fiber fabric and combined with at least one layer of the conductive sheet part and the semiconductive sheet part. That is. In the flexible sheet of the present invention, semiconductive sheet portions are formed on both the front and back surfaces of the conductive sheet portion. Further, the specific resistance value of the above-mentioned conductive sheet portion (hereinafter referred to as the conductive sheet portion) is 10 ³ Ω・cm or less, and the resistance value of the semiconductive sheet portion is 10 ⁵ to 10 ⁸ Ω.・cm, and it is preferably 10 ⁶ to 10 ⁸ Ω·cm especially for applications where electric leakage is strictly avoided. In addition, the difference in specific resistance between the conductive sheet portion and the semiconductive sheet portion is at least
Preferably, it is on the order of 10 ² Ω·cm. If the specific resistance value of the semiconductive sheet portion is less than 10 ⁵ Ω·cm, the leakage prevention effect of the obtained flexible sheet will be insufficient, and various troubles due to current leakage may occur, which is dangerous. In order to achieve the purpose of the invention, the sheet of the invention must be flexible in nature. Therefore, when manufacturing the sheet of the present invention,
In general, it is best to mix a conductive material into a matrix made of synthetic resin, synthetic rubber, or natural rubber and adjust the resistance to a predetermined value to form a sheet.
Alternatively, the sheet may be formed only from semiconductive resin or rubber material. As described above, a matrix made of synthetic resin, synthetic rubber, or natural rubber is used for the conductive sheet portion and the semiconductive sheet portion constituting the flexible sheet of the present invention. Examples of preferred synthetic resins include polyvinyl chloride (PVC), polyurethane, ethylene-vinyl acetate copolymer, isotactic polypropylene, polyethylene, polyacrylonitrile, polyester and polyamide, and other known materials. Examples of preferable synthetic rubbers include styrene-butadiene rubber (SBR), chlorosulfonated polyethylene rubber,
Examples include polyurethane rubber, butyl rubber, isoprene rubber, and other known materials. The most preferred synthetic resin is PVC, which may contain plasticizers, fillers, colorants, stabilizers and/or other modifiers. Further, depending on the use and purpose, these matrices may contain bubbles or may be porous. The conductive material blended into these matrices to control the resistance value of each sheet may be a liquid, powder, fiber, foil, wire or sheet conductive material, such as carbon. Black, metal such as Al, Au, Ag, Pt, Cu,
Cr, Ni, Zn, Ti, Pb, Sn, Pd and their compounds, Ni-Cr alloys, or other conductive compounds,
For example, indium oxide. The amount of the conductive substance to be blended is determined by taking into account the conductivity and properties inherent to the substance and the desired degree of conductivity, but it is preferably at least 5% by weight, and preferably 10 to 70% by weight. is even more preferable. Of course, the blending amount of the conductive substance is not limited to 70% by weight or less,
Particularly in the case of the conductive sheet portion, the amount may be greater than 70% by weight as long as the desired flexible sheet properties (strength, flexibility, appearance, etc.) are achieved. For reference, the specific resistance values of various materials are shown below.

【table】

[Effect]

In the flexible sheet according to the present invention, at least one outermost surface layer consists of a semiconductive sheet part (it is particularly preferable that both outer surface layers consist of a semiconductive sheet part), and the lower layer or middle layer is the entire The sheet may be composed of a conductive sheet portion or a layer partially including a conductive sheet portion. The conductive sheet portion is effective in assisting electrical dissipation in the semiconductive sheet portion,
It also has the effect of discharging static electricity generated in the semiconductive sheet portion by transmitting it through the sheet itself and having a grounding effect, without discharging it to the outside. Therefore, it is preferable that the sheet be in close contact with the semiconductive sheet portion. In this case, the difference in resistivity between the conductive sheet portion and the semiconductive sheet portion is at least
Since it is on the order of 10 ² Ω・cm, the current flows particularly concentrated in the conductive sheet part, and the discharge of static electricity generated in the semiconductive sheet part to the outside is more effectively prevented. be. Further, in the sheet of the present invention, since at least one of the outermost surface layers is made of a semiconductive sheet portion, the sheet has an extremely large shielding effect against radio waves and the like. If this semiconductive sheet portion is not semiconductive and is made of a nonconductive material having a specific resistance value of 10 ¹⁰ Ω·cm or more, the antistatic effect and radio wave shielding effect will be significantly reduced. In addition, this semiconductive sheet part has a resistance of 10 ² Ω・
If the composite sheet is made of a material having a resistivity smaller than cm, the resulting composite sheet loses its leakage prevention effect. Conventionally, the layer constituting the outer surface was made of an insulating material (10 ¹⁰ Ω cm or more), and conductive and semiconductive parts were formed in spots on the surface.
Some materials have a closed structure with an insulating part, but in this case, there is no place for static electricity or charged electricity to escape, and it is undesirable because it partially accumulates and discharges. There were also ideas to actively provide protrusions and the like to facilitate discharge, but these were not desirable. Furthermore, the purpose of the conductive sheet part is to shield penetrating radio waves, and for this purpose, the semiconductive sheet part and the conductive sheet part do not need to be in close contact with each other, or a reinforcing sheet part may be interposed between them. You can leave it there. Particularly in the case of a sheet having semiconductive sheet portions on both outer surfaces, great effects can be obtained even if the sheet has at least one conductive sheet portion as an intermediate layer. In addition, it goes without saying that such a sheet may have one or more reinforcing sheet portions 6 at any location within the sheet of the present invention, as shown in Fig. 2 A, B, and C. . Similarly, as shown in FIG. 1, the outer surface can be a semiconductive sheet part 2, the lower part can be a conductive sheet part 1, and the lower part can be a reinforcing sheet part 6. In this case, the sheet has a configuration that meets the required performance when using the upper and lower surfaces, and the upper and lower surfaces contact each other arbitrarily.
This does not cause problems such as sticking during handling. In the case of the sheet shown in FIG. 2A, in addition to the above-mentioned effects, both the front and back surfaces can be used for different purposes, and if the reinforcing sheet portion 6 is divided into sections, different electrical performances can be achieved. It can also be used for partially required applications. The surface of the sheet can be colored in any color and pattern, and when creating the sheet,
Calendar method, topping method, date ping method,
A coating method, a lamination method, an extrusion molding method, a spreading method and other arbitrary methods can be used. [Example] The present invention will be further explained by the following example. Example 1 A plain woven fabric with a gray weight of 90 g/m ² was prepared by inserting 45 250 denier polyester filaments into the warp and weft at a rate of 45/inch each, and this fabric was
After immersing and impregnating 100 parts by weight of PVC in a processing solution containing 50 parts by weight of DOP and 40 parts by weight of carbon black (Ketin black), pick up 100 parts by weight.
%, then dried, and gelatinized and fixed at 180° C. to form a conductive sheet combined with the reinforcing sheet portion. The thickness of this sheet was approximately 0.25 mm, and the specific resistance value was 10 ⁰ Ω·cm. For this sheet, then for 100 parts by weight of PVC,
DOP50 parts by weight and Kechin Carbon Black 5.5
A processing liquid to which parts by weight were added was applied to both sides one at a time, dried, and fixed by gelling heat treatment to obtain a flexible sheet having semiconductive sheet portions with a thickness of about 0.1 mm on both the front and back sides, respectively. The specific resistance value of this semiconductive sheet portion was 10 ⁸ Ω·cm, and the thickness of the entire flexible sheet was approximately 0.5 mm. The handling properties of this sheet were extremely good, no sticking was observed as with conventional sheets, and the sheet could be handled extremely easily. In addition, when we created a simple box in the laboratory using this sheet and performed sewing work using a high-frequency sewing machine in the box, we observed no noise at all when we observed a television screen that was lit just outside. . Further, the following charging property test and electric shockability test were conducted on this flexible sheet. Charging property test JIS
L1021, 6.16.1 "Rug test method, Stroll method" was applied to frictional charging treatment, and the static electricity charging status was measured. Electric Shock Test Two electrodes are placed on the upper surface of the flexible sheet under test with an interval of 50 cm between them.
A voltage of volts was applied and the amount of current flowing between both electrodes was measured. The performance and test results of the flexible sheet are shown in Table 1. Example 2 The same operation as in Example 1 was performed. However, the amount of carbon black added to the processing liquid for forming the conductive sheet portion was 20 parts by weight. Table 1 shows the performance and test results of the obtained flexible sheet. Example 3 The same operation as in Example 1 was performed. However, instead of carbon black, 60 parts by weight of nickel powder was added to the processing liquid for forming the conductive sheet portion. Table 1 shows the performance and test results of the obtained flexible sheet. Comparative Example 1 The same operation as in Example 1 was performed. However, the amount of carbon black added to the processing liquid for forming the conductive sheet portion was 5 parts by weight. Table 1 shows the performance and test results of the obtained flexible sheet. Comparative Example 2 The same operation as in Example 1 was performed. However, the amount of carbon black added to the processing liquid for forming the conductive sheet portion was 6.5 parts by weight. Table 1 shows the performance and test results of the obtained flexible sheet. Comparative Example 3 The same operation as in Example 1 was performed. However, the amount of carbon black added to the processing liquid for forming the conductive sheet portion was 5 parts by weight, and the amount of carbon black added to the processing liquid for forming the semiconductive sheet portion was 5 parts by weight. Table 1 shows the performance and test results of the obtained flexible sheet. Comparative Example 4 The same operation as in Example 1 was performed. However, the amount of carbon black added to the processing liquid for forming the conductive sheet portion was 7 parts by weight, and the amount of carbon black added to the processing liquid for forming the semiconductive sheet portion was 5 parts by weight. Table 1 shows the performance and test results of the obtained flexible sheet. Comparative Example 5 The same operation as in Example 1 was performed. However, the amount of carbon black added to the processing liquid for forming the semiconductive sheet portion was 5 parts by weight. Table 1 shows the performance and test results of the obtained flexible sheet. Comparative Example 6 The same operation as in Example 1 was performed. However, 60 parts by weight of nickel powder was used instead of carbon black in the processing liquid for forming the conductive sheet, and the amount of carbon black added to the processing liquid for forming the semiconductive sheet was 5 parts by weight. Table 1 shows the performance and test results of the obtained flexible sheet. Comparative Example 7 The same operation as in Example 1 was performed. However, the amount of carbon black added to the processing liquid for forming the conductive sheet portion was 40 parts by weight, and the amount of carbon black added to the processing liquid for forming the semiconductive sheet portion was 20 parts by weight. Table 1 shows the performance and test results of the obtained flexible sheet.

[Effect of idea]

As described above, the sheet of the present invention prevents static electricity, prevents charging, does not cause radio wave interference, and has no risk of electrical leakage, and has extremely innovative combined effects. Therefore, this sheet also has the surprising advantage of being suitable for multiple purposes by itself, and is of great industrial value. Furthermore, since this sheet is flexible, it can be used to cover any article in its own shape, and it can also be used by sewing it onto wind pipes or other arbitrary shapes. This makes it possible to easily supply a wide variety of products.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are sectional views each schematically showing an example of the flexible sheet of the present invention,
FIG. 3 is a schematic diagram showing an example of a reinforcing sheet fabric that can be used in the seat of the present invention. 1... Conductive sheet part, 2... Semi-conductive sheet part, 3... Warp, 4... Weft, 5... Leno thread,
6...Reinforcement sheet section.

Claims (1)

[Claims for Utility Model Registration] At least one flexible conductive sheet portion containing a flexible resin or rubber material as a matrix component and having a specific resistance value of 10 ³ Ωcm or less; a flexible resin; or at least one flexible semiconductive sheet portion containing a rubber material as a matrix component, having a specific resistance value of 10 ⁵ to ^{10 8} Ω·cm, and laminated and integrated with the conductive sheet portion; A flexible sheet for preventing electrical disturbances, comprising a flexible reinforcing sheet part made of fiber cloth, which is combined with at least one layer of the conductive sheet part and the semiconductive sheet part.