JPH08800Y2 - Flexible sheet to prevent electrical and electromagnetic interference - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric and electromagnetic wave interference preventive flexible sheet capable of effectively preventing electric and electromagnetic wave interference and having practically sufficient mechanical strength.

[0002]

2. Description of the Related Art Conventionally, flexible sheets made of various synthetic resins or synthetic or natural rubber have been used as flexible covering materials for equipment covers and the like.
Many of these are reinforced with fiber materials. However, these sheets are electrically insulative in nature, typically 10 ¹⁰ to 10 ¹⁷ Ω · cm, often 10 ¹² Ω · cm.
It had the above specific resistance value. Therefore, these conventional sheets generate static electricity due to surface friction,
There was a strong tendency to be charged.

With the recent development and widespread use of various electric devices, the occurrence of static electricity and electromagnetic interference due to static electricity generation and electrification of the flexible sheet has been increasing, and a drastic solution to this problem is strongly required. Came.

In the case of such a flexible sheet, it is conceivable that the purpose can be achieved by applying a conductive paint or the like on the surface of a normal non-conductive sheet.
In that case, the adhesiveness of the conductive paint to the surface of the sheet becomes a problem, and the flexible sheet is easily bent due to severe bending, and it is difficult to obtain a sheet having a sufficient practical use life. . In addition, when applying a conductive paint, there are many problems in terms of hue and it is difficult to obtain a colorful sheet, and there are problems such as the coating technique and the performance of the coating film. It was difficult to form a flexible film.

Further, even if only one side of the sheet is made conductive, if the opposite side is insulative, the opposite side is easily charged with static electricity. Therefore, the electromagnetic shielding and charging due to only the conductive side is carried out. In terms of prevention, it could not be used in applications where electrostatic charging is extremely disliked.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a flexible sheet that does not generate static electricity and is not charged, and therefore does not generate electric and electromagnetic interference.

[0007]

A flexible sheet for preventing electrical and electromagnetic interference according to the present invention comprises a two-layer or three-layer conductive or semi-conductive flexible sheet portion having a specific resistance value of less than 10 ⁸ Ω · cm. , 1 layer or 2 layers of electrical insulation inserted / laminated between the 2 or 3 layers of conductive or semi-conductive flexible sheet portions and having a specific resistance value of 10 ¹⁰ Ω · cm or more A laminate having a flexible sheet portion, wherein both front and back surfaces of the laminate are formed by the conductive or semi-conductive flexible sheet portion, and the conductive or semi-conductive flexible sheet portion is an electric layer. The insulating flexible material comprises a matrix component consisting of at least one selected from an insulating rubber and a synthetic resin, and a conductive substance contained in the matrix component. The bull sheet portion is formed of at least one selected from an electrically insulating rubber and a synthetic resin, and at least one layer between the electrically insulating flexible sheet portion and the conductive or semi-conductive flexible sheet portion is provided. Another feature is that a reinforcing material layer made of a fibrous knitted fabric is sandwiched.

[0008]

[Function] A flexible sheet for preventing electric and electromagnetic interference of the present invention (hereinafter referred to as a flexible sheet of the present invention)
Is a laminate having one layer or two layers of electrically insulating flexible sheet portion and two layers or three layers of conductive or semi-conductive flexible sheet portion alternately laminated and adhered to the electrically insulating flexible sheet portion, The front and back surfaces of this laminate are each formed of one layer of the conductive or semiconductive flexible sheet portion. The insulating flexible sheet portion used in the present invention has a specific resistance value of 10 ¹⁰ Ω · cm or more,
It is preferably 10 ¹⁰ to 10 ¹⁸ Ω · cm.

The conductive or semi-conductive flexible sheet portion used in the present invention has a specific resistance value of 10 ⁸ Ω · cm.
However, the conductive flexible sheet portion having a specific resistance value of 10 ⁵ Ω · cm or less is preferable. In this case, the specific resistance value may be 10 ¹ Ω · cm or less, if necessary. .

In the flexible sheet of the present invention,
Each of the insulating sheet and the conductive or semiconductive sheet needs to be flexible. In the flexible sheet of the present invention, both front and back surfaces are formed by conductive or semi-conductive flexible sheet portions, and one layer of insulating property is provided between the front and back conductive or semi-conductive flexible sheet portions. A sheet-like base body composed of a flexible sheet part or composed of two layers of insulating flexible sheet parts and one layer of conductive or semi-conductive flexible sheet part inserted and laminated between them is sandwiched and laminated. There is. Further, a reinforcing material layer made of a fibrous knitted fabric is laminated and sandwiched between at least one layer between the insulating flexible sheet portion and the conductive or semi-conductive flexible sheet portion.

The conductive or semi-conductive flexible sheet portion used in the present invention is prepared by blending a conductive material in a matrix made of synthetic resin, synthetic rubber or natural rubber, and adjusting the specific resistance value of this blend to a predetermined value. Formed.

As described above, an electrically insulating synthetic resin, synthetic rubber or natural rubber is used for the matrix of the conductive or semi-conductive flexible sheet portion and the insulating flexible sheet portion constituting the flexible sheet of the present invention. . An example of a preferable synthetic resin is polyvinyl chloride (P
VC), polyurethane, ethylene-vinyl acetate copolymer, isotactic polypropylene, polyethylene,
There are polyacrylonitrile, polyester and polyamide and other known materials. Examples of preferable synthetic rubber include styrene-butadiene rubber (SBR), chlorosulfonated polyethylene rubber, polyurethane rubber, butyl rubber and isoprene rubber, and other known materials. The most preferred synthetic resin is PVC, which may include plasticizers, fillers, colorants, stabilizers, blowing agents and / or other modifiers. Further, these rubbers or synthetic resin materials may contain air bubbles or may be porous depending on the use or purpose.

The conductive material mixed in the matrix of the conductive or semi-conductive flexible sheet portion to control its specific resistance value to a desired value is liquid, powder, fibrous or foil-like. , Linear or sheet-like conductive material such as carbon black, metal such as Al, Au, Ag, Pt, Cu, Cr, Ni, Zn, T
i, Pb, Sn, Pd and their compounds or Ni-Cr
Alloys or other conductive compounds such as indium oxide. The amount of the conductive substance blended is determined in consideration of the conductivity unique to the substance, the property and the desired degree of conductivity, but is preferably at least 5% by weight,
More preferably, it is 70% by weight. Of course, the compounding amount of the conductive substance is not limited to 70% by weight or less, and particularly in the case of the conductive flexible sheet portion, desired flexible sheet properties (strength, flexibility, appearance, etc.)
May be more than 70% by weight, as long as it has For reference, the specific resistance values of various materials are shown below.

Material resistivity (Ω · cm) Natural asphalt 10 ¹⁵ to 10 ¹⁷ Vulcanized natural rubber 10 ¹⁵ to 10 ¹⁷ Butyl rubber 10 ¹⁵ to 10 ¹⁶ SBR 10 ¹² Polyisoprene 10 ¹⁵ Ethylene-propylene rubber 10 ¹⁵ to 10 ¹⁶ Neoprene 10 ¹⁰ to 10 ¹² Chlorosulfonated polyethylene rubber 10 ¹⁴ Urethane rubber 10 ¹⁴ to 10 ¹⁵ Polyethylene terephthalate 10 ¹⁹ Nylon 6 10 ¹² to 10 ¹⁵ Nylon 66 10 ¹³ to 10 ¹⁴ Polypropylene 10 ¹⁶ Polyvinyl chloride 10 ¹⁶ to 10 ¹⁷ Nomec paper 10 ¹⁶ cotton 10 ^{7 -10 12} carbon black, graphite 100 ^{0 -10 -3} stainless steel 10 ^{-4 -10 -6}

The thickness of each of the insulating flexible sheet portion and the conductive or semi-conductive flexible sheet portion is not particularly limited as long as the flexibility of the sheet is not impaired, but it is generally preferably 1 μm or more, More preferably 10 to 1000 μm,
Of course, it may be thicker than this.

As described above, the flexible sheet of the present invention made of the above materials is a combination of a conductive or semi-conductive flexible sheet portion, an insulating flexible sheet portion, and a fibrous knitted fabric reinforcing material layer. However, the structure of the flexible sheet of the present invention will be described in more detail below with reference to the accompanying drawings.

1 and 2 are cross-sectional views schematically showing an example of an electric and electromagnetic wave interference preventing flexible sheet according to the present invention in the accompanying drawings. In the flexible sheet of the present invention shown in FIG. 1, conductive or semi-conductive flexible sheet portions 2a and 2b are formed on both sides of a sheet-like base body made of an insulating flexible sheet portion 1a. And the conductive or semiconductive flexible sheet portion 2a, the fibrous knitted fabric reinforcing material layer 3a is sandwiched and sandwiched. This reinforcing material layer may be arranged between the insulating flexible sheet portion 1a and the conductive or semi-conductive flexible sheet portion 2b.

In the flexible sheet shown in FIG. 2, the sheet-like substrate 4 has two layers of insulating flexible sheet portions 1b and 1c and one layer of conductive or semiconductive flexible inserted and laminated between them. The sheet 2c and the conductive or semi-conductive flexible sheet portions 2a and 2b are disposed on both front and back surfaces thereof, and between the conductive or semi-conductive flexible sheet portion 2a and the insulating flexible sheet portion 1b. The fibrous knitted fabric reinforcing material layer 3b is laminated and sandwiched, and the fibrous knitted fabric reinforcing material layer 3c is laminated and sandwiched between the insulating flexible sheet portion 1c and the conductive or semi-conductive flexible sheet portion 2b. The fibrous knitted fabric reinforcing material layer may be laminated and sandwiched between one or both of the layers of the conductive or semi-conductive flexible sheet portion 2c of the sheet-like substrate 4 and the insulating flexible sheet portions 1b and 1c. Good. The flexible sheet of the present invention having the configuration shown in FIG. 2 is a particularly preferable embodiment because it can improve the safety and reliability even when the usage environment conditions on the front and back sides are different.

In the production of the flexible sheet of the present invention, the conductive or semi-conductive flexible sheet portion may be formed of a conductive or semi-conductive sheet (or film), or conductive or semi-conductive. It may be formed from a film forming liquid.

In order to carry out the above steps, calendering method, topping method, dipping method, coating method,
A laminating method, an extrusion molding method, a spreading method, and any other method can be used.

In the flexible sheet of the present invention, as shown in FIG. 1, two outer surfaces are formed by conductive or semi-conductive flexible sheet portions 2a and 2b, and a sheet-like substrate inside thereof is an insulating flexible sheet portion 1a only. It is also possible to dispose the fibrous knitted fabric reinforcing material layer 3a on one or two of these layers. In this case, the seat has a configuration that conforms to the required performance when using the upper and lower surfaces,
It does not cause problems such as clinging when handling.

As shown in FIG. 2, two layers of insulating flexible sheet portions 1b and 1c and one layer of conductive or semi-conductive flexible sheet portion 2c sandwiched between them are laminated. A sheet-shaped substrate 4 configured,
In the case of the flexible sheet of the present invention comprising a conductive or semi-conductive flexible sheet portion covering both front and back sides with fibrous knitted fabric reinforcing material layers 3b and 3c, the conductivity of the outermost surface on both front and back sides is improved. Flexible sheet portions 2a and 2b
Each of them has antistatic and electromagnetic wave blocking functions,
Insulating flexible sheet portions 1b and 1c therebelow prevent leakage, and conductive flexible sheet portions 2c therebelow.
The (central layer) blocks electromagnetic waves to prevent the interference, and the insulating flexible sheet portion 1c thereunder further improves the electrical insulation of the flexible sheet of the present invention. Therefore,
The electrical condition loaded (or generated) on one of the conductive or semi-conductive flexible sheet portions on the outermost surfaces of the front and back is
Without interlocking with the other, the effects of preventing static electricity and preventing electromagnetic interference can be independently achieved. Therefore, the flexible sheet of the present invention having this structure may be used by making the electric conditions on the front and back sides different from each other. For example, even if the flexible sheet of the present invention is used as a work sheet, it is possible to prevent electrical changes or troubles on the outer surface from affecting electric equipment or human bodies in contact with the inner surface.

The flexible sheet of the present invention includes a reinforcement layer. This reinforcement layer is formed of a fibrous knitted fabric. Fibrous knitted fabrics useful in the present invention include natural fibers such as cotton and linen, inorganic fibers such as glass fibers, regenerated fibers such as viscose rayon, cupra and the like, semi-synthetic fibers such as dice And at least one selected from synthetic fibers such as nylon 6, nylon 66, polyester (polyethylene terephthalate) fibers, aromatic polyamide fibers, acrylic fibers, polyvinyl chloride fibers, and polyolefin fibers. Can be used. The fibers in the knitted fabric may be of any shape such as short fiber spun yarn, long fiber yarn, split yarn, tape yarn, etc., and the knitted fabric may be a woven fabric, a knitted fabric or a composite fabric thereof. May be. Generally,
The fibers used in the flexible sheet of the present invention are preferably polyester fibers, and the fibers are preferably in the form of filaments. The fibrous knitted fabric is useful for maintaining the mechanical strength of the obtained flexible sheet of the present invention at a high level. Examples of useful woven fabrics include twill woven fabrics, plain woven fabrics and other woven fabrics having a general design.

In the present invention, the fibrous knitted fabric reinforcing material layer comprises:
The conductive or semi-conductive flexible sheet portion and the insulating flexible sheet portion are sandwiched and laminated in at least one of the layers. Of course, such a fibrous knitted fabric reinforcing material layer may be included not only in one layer but also in two or more layers.

The conductive or semi-conductive flexible sheet portion has the effect of preventing electrostatic charging and shielding of penetrating electromagnetic waves. The effect is that the insulating flexible sheet portion and the conductive or semi-conductive flexible sheet portion are directly adjacent to each other. Alternatively, the fibrous knitted fabric reinforcement layer can be obtained even if it is interposed between the layers.

The present invention will be further described below with reference to examples.

[0027]

EXAMPLE As an example of the flexible sheet of the present invention, a plain weave fabric was prepared by weaving 250 denier polyester filaments for warp and weft at a density of 45 filaments / 25.4 mm. An insulating sheet containing 100 parts by weight of a polyvinyl chloride resin, 60 parts by weight of dioctyl phthalate, and a predetermined amount of a stabilizer is prepared according to
Glued to the surface. The plain weave fabric / insulating flexible sheet adhesive was a flexible sheet having a thickness of about 0.25 mm. The specific resistance value of the insulating flexible sheet was 10 ¹⁶ Ω · cm.

Next, a conductive processing liquid containing 100 parts by weight of polyvinyl chloride resin and 250 parts by weight of carbon black was applied to both sides of the plain weave fabric / insulating sheet adhesive, dried, and dried at 180 ° C. A gelling heat treatment was performed to form a conductive flexible sheet portion having a thickness of 0.1 mm on each side and a specific resistance of 10 ⁴ to 10 ⁶ Ω · cm. The total thickness of the obtained flexible sheet was about 0.5 mm.

When a simple box was made in the laboratory using the flexible sheet of the present invention and sewing work was carried out using a high frequency sewing machine, no noise was generated on the television screen that was lit just outside. .
For comparison, a similar test was conducted using a conventional PVC sheet, but the TV screen was disturbed. In the test conducted with the conventional PVC sheet only subjected to the antistatic treatment, the TV screen was also disturbed.

In addition, the flexible sheet of the present invention does not generate static electricity or charge on either of the front and back surfaces thereof, and has relatively high conductivity on both surfaces. It is possible to block troubles such as electric leakage, and the flexible sheet as a whole is free from troubles such as charging, discharging, and electric leakage.
It was able to be used safely and effectively.

[0031]

[Effects of the Invention] The flexible sheet of the present invention prevents electrostatic charging on both the front and back surfaces and does not cause electromagnetic interference.
Further, there is no danger of electric leakage to the back surface side, and even if it is used for applications where surface friction is severe, the above-mentioned electrical characteristics can be maintained with excellent durability, and an extremely epoch-making composite effect is exhibited. Therefore, the flexible sheet of the present invention has an amazing advantage that it is suitable for various purposes by itself, and is of great industrial value. Furthermore, since the flexible sheet of the present invention is flexible,
Since it is possible to cover any article in its original shape and sew it into any shape, it is possible to easily supply a great variety of products. The flexible sheet of the present invention has practically sufficient mechanical strength.

[Brief description of drawings]

FIG. 1 is an explanatory cross-sectional view of an example of a flexible sheet of the present invention.

FIG. 2 is a cross-sectional explanatory view of another example of the flexible sheet of the present invention.

[Explanation of symbols]

1a, 1b, 1c ... Electrically insulating flexible sheet portion 2a, 2b, 2c ... Conductive or semi-conductive flexible sheet portion 3a, 3b, 3c ... Fibrous knitted fabric reinforcing material layer 4 ... Sheet-shaped substrate

Claims (8)

[Scope of utility model registration request] 1. A two-layer or three-layer conductive or semi-conductive flexible sheet portion having a specific resistance value of less than 10 ⁸ Ω · cm, and the two-layer or three-layer conductive or semi-conductive flexible sheet. It is inserted and laminated between layers of parts, and 1
A laminate having one or two layers of electrically insulating flexible sheet having a specific resistance value of 0 ¹⁰ Ω · cm or more, wherein the front and back surfaces of the laminate each have one layer of the conductive material. Alternatively, the conductive or semi-conductive flexible sheet portion is formed by a semi-conductive flexible sheet portion, and the conductive or semi-conductive flexible sheet portion comprises a matrix component consisting of at least one selected from an electrically insulating rubber and a synthetic resin, and a matrix component in the matrix component. And a conductive substance contained therein, wherein the insulating flexible sheet portion is formed of at least one selected from an electrically insulating rubber and a synthetic resin, and the electrically insulating flexible sheet portion And a reinforcing material layer made of a fibrous knitted fabric is sandwiched between at least one of the layers of the conductive or semi-conductive flexible sheet portion. It is, electrical and electromagnetic interference preventing flexible sheet characterized by. 2. The flexible sheet for preventing electric and electromagnetic interference according to claim 1, wherein the conductive flexible sheet portion has a specific resistance value of 10 ⁵ Ω · cm or less. 3. The flexible sheet for preventing electric and electromagnetic interference according to claim 1, wherein the insulating flexible sheet portion has a specific resistance value of 10 ¹⁰ to 10 ¹⁸ Ω · cm. 4. The electrical and electromagnetic interference prevention flexible according to claim 1, wherein the insulating rubber is selected from natural rubber, styrene-butadiene rubber (SBR), chlorosulfonated polyethylene rubber, polyurethane rubber, butyl rubber, and isoprene rubber. Sheet. 5. The insulating synthetic resin is polyvinyl chloride,
The flexible sheet for preventing electric and electromagnetic interference according to claim 1, which is selected from polyurethane, ethylene-vinyl acetate copolymer, polypropylene, polyethylene, polyacrylonitrile, polyester, and polyamide. 6. The flexible sheet for preventing electrical and electromagnetic interference according to claim 1, wherein the content of the conductive material is at least 5% by weight based on the conductive or semiconductive flexible sheet portion. 7. The flexible sheet for preventing electric and electromagnetic interference according to claim 6, wherein the content of the conductive material is 10 to 70% by weight. 8. The conductive material is carbon black,
The flexible sheet for preventing electric and electromagnetic interference according to claim 1, which is selected from a conductive metal, a conductive alloy and a conductive metal compound.