JPH0221507A - Electric conductive sheet - Google Patents

Abstract

PURPOSE:To make it possible to obtain an electric conductive sheet with permeability between the front side and the rear side by forming metallic evaporation layers on both sides of a base material and also forming the metallic evaporation layers at the inner walls of penetrating holes of the basic material. CONSTITUTION:On both sides of a basic material 1 which furnishes penetrating holes 2, metallic evaporation layers 3 are formed, and at least at some of the penetrating holes, metallic evaporation layer 3 are formed at their inner walls. And the metallic evaporation layers 3 on the front side and the rear side are connected electrically through the penetrating holes 2. Since the metallic evaporation layers 3 are formed at the inner walls 4 of the penetrating holes 2 when the metallic evaporation layers 3 are formed on the both surfaces of the basic material 1, the electric conductibility can be obtained between the front side and the rear side of the basic material 1 through the metallic evaporation layers 3. Furthermore, the electric conductibility can be controlled by the number of the holes 2, the size of the holes 2, the thickness of the metallic evaporation layers 3, and the thickness of the basic material 1, and the air permeability and the slipping property can be also controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a conductive sheet. More specifically, the present invention relates to a conductive sheet having conductivity in both the surface direction and the thickness direction.

[Conventional Technique #FI] A conductive plastic film (for example, US Pat. No. 4,103,066), which is formed by kneading a conductive material (for example, carbon) into a resin, has been known.

[Problems to be Solved by the Invention] However, the conductive sheet in the conventional example has the following problems.

(b) High electrical resistance.

(a) No breathability.

(1) The properties of the film resin are impaired by incorporating the conductive material.

) Decorative or not good.

((e) Cost is high.

In view of the above points, the present invention has excellent electrical conductivity, air permeability, and decorative properties without impairing the resin properties, and is low in cost. The object of the present invention is to provide a conductive sheet suitable for use as a coating base material for signboards, marking sheets, dry battery checkers, etc., as well as for shielding materials.

[Means for Solving the Problems] In the conductive sheet of the present invention, metal vapor deposited layers are formed on both the front and back sides of a base material having one through hole, and at least a part of the through hole is also formed on the inner wall of the through hole. It is characterized in that a metal vapor deposited layer is formed, and the metal vapor deposited layers on both the front and back surfaces are electrically connected through a through hole.

[Function] The base material has a through hole, and when a metal vapor deposited layer is formed on both the front and back surfaces of the base material, the metal vapor deposited layer is also formed on the inner wall of the through hole, so the base material is formed through the metal vapor deposited layer. Not only does it have the ability to obtain electrical conductivity between the front and back surfaces of the material, but it also has the ability to control electrical conductivity by controlling the number of holes, the size of the holes, the thickness of the metal deposited layer, and the thickness of the base material. . It also has the effect of controlling air permeability and slipperiness. Furthermore, by changing the type of metal in the metal vapor deposited layer, the characteristics of the metal can be utilized, and the metal vapor deposited layer has the effect that the surface thereof has a metallic luster peculiar to metals and is excellent in decorative properties.

[Example] Next, the conductive sheet of the present invention will be explained based on the drawings.

Both FIG. 1 and FIG. 2 are schematic partial cross-sectional views showing examples of the conductive sheet of the present invention, and the one shown in FIG. A metal vapor deposited layer (3) is formed on both the front and back surfaces, and at least a part of the through hole (2) also has a metal vapor deposited layer (3) on the inner wall (2) of the through hole (2).
The basic structure of the conductive sheet of the present invention is shown in FIG. 9 shows the structure of another example of the conductive sheet of the present invention, in which (1) is the base material and (2) is the base material.
) is the through hole provided in the base material (1), (4 is the metal vapor deposited layer provided in the base material (1), (4) is the inner wall of the through hole (2), and (5) is the metal vapor deposited layer provided in the base material (1). ) is a conductive adhesive layer provided on the surface of the metal vapor deposited layer (3).

As the base material (1), any material can be used as long as it has a certain degree of self-retention, such as polyester resin, polyamide resin, polyamideimide resin,
Resins such as polyethylene resin, polypropylene resin, cellulose acetite resin, polycarbonate resin, polyvinyl chloride resin, polyetherimide resin, polyimide resin, acrylic resin, fluorine resin, cellophane paper, Western paper Film-like materials or sheet-like materials such as , Japanese paper, and nonwoven fabrics may be mentioned, and these materials may be a single layer or two or more layers bonded together.

In particular, when the base material (1) is a film of the above-mentioned resins, there is no particular restriction on the thickness, and a range of 6 to 250 M is usually preferred. If the thickness is less than 6 μs, drilling and vapor deposition workability will be reduced. If the thickness exceeds 250 μs, the workability of drilling and vapor deposition is also poor and impractical.

In addition, in the case of sheet-like materials such as cellophane paper, Western paper, Japanese paper, and non-woven fabric, there is no particular limit to the basis weight, or it is usually 10 to 10.
The range of 1000g/■2 is preferable.6 The tsubo weight is 10g/m.
If it is less than 1, the strength of the product will be weak and it will not be practical.

If the basis weight exceeds 1000 g/2, a large amount of gas is released in the vapor deposition apparatus, resulting in poor vapor deposition efficiency and impractical use.

The size of the through hole (2) is not particularly limited, and is usually 50 to 1000 μm depending on the thickness of the base material (11).
s (diameter equivalent) is preferable, and the thicker the base material (1) is, the larger the hole size is, which is preferable because it improves electrical conductivity, and there is no particular restriction on the number of through holes (2). The thickness of the base material (1) according to the desired electrical resistance value,
It is determined by taking into consideration the size of the hole, the thickness of the metal vapor deposited layer (3), the type of metal, etc., and usually 10,000 to 2 million pieces 7.2
be selected as appropriate from the range.

Examples of the metal vapor deposited layer (3) include gold, silver, aluminum, copper, nickel, zinc, gallium, indium, tin, silicon, chromium, titanium, platinum, palladium, nickel-chromium, stainless steel, Examples include vapor-deposited metals such as Hastelloy, which are made of a single substance, a mixture, or an alloy. Gold, silver, copper, aluminum, platinum, nickel, and palladium are particularly preferably used because of their electrical conductivity and ease of vapor deposition. In particular, the metal vapor-deposited layer (6) is one in which the metal is vapor-deposited, and its thickness is not particularly limited, and is preferably in the range of 10 to 1100 nm. If the thickness is less than IOr+■, the electrical conductivity and metallic luster will be insufficient, making it impractical; on the other hand, even if the thickness exceeds 1100 nm, the V between the metal thin film and the base material, adhesion strength, workability, etc. Since the metallic luster remains the same, it is less economical and not practical.

In this specification, vapor deposition refers to the formation of thin films of metals, etc., by ordinary thin film forming methods of metals (including alloys and metal compounds, the same shall apply hereinafter) such as vacuum evaporation, sputtering, and ion blating. means. Note that the metal vapor deposition layer is not limited to one layer, but may be composed of two or more layers in order to prevent corrosion, reduce costs, and obtain a desired color tone.

The metal adhesion layer (3) includes all of the metal thin films formed by these metal thin film forming methods.

If necessary, a conductive adhesive layer (5) is used in the conductive sheet of the present invention. The conductive adhesive layer (5).

It is required to have excellent adhesion to the metal vapor deposited layer (3) and the object to be adhered. Examples of adhesives that meet this requirement are 1, for example, polyethylene resin, polyamide resin,
Polyester resin system, polybutyral resin system, polyvinyl acetate resin system, cellulose resin system, polymethyl methacrylate resin system, polyvinyl ether resin system, polycarbonate resin system, ethylene-vinyl acetate copolymer, chlorinated polypropylene resin system, vinyl chloride - Metal powders (silver, copper, , aluminum, nickel, etc.), non-metal powders (amorphous carbon, graphite), and some metal oxides such as tin oxide and indium oxide. The amount of conductive material added is appropriately determined depending on the degree of electrical conductivity expected of the adhesive.

Is there any particular restriction on the thickness of the conductive adhesive layer? A range of 5 to 20 μs is preferable. If the thickness is less than 5 μs, sufficient adhesive strength will not be obtained and the surface resistance value will decrease. On the other hand, if the thickness exceeds 20 μs, solvent may remain or the conductive adhesive layer (
It is not practical because it may cause fluidization of the liquid (f) and impede the flow of the process.

In addition, a conductive anti-corrosion layer should be provided on the surface of the metal vapor deposited layer (3), as silver, aluminum, and copper are particularly susceptible to corrosion due to their weak mechanical strength and are susceptible to damage due to friction. You can.

There is no particular limit to the thickness, but it is preferably in the range of 5 to 20. If the thickness is less than 5 μs, the corrosion prevention effect will be small, the surface resistance will be high, and it will not be practical as a conductive corrosion prevention layer.
On the other hand, even if the thickness exceeds 20 mm, the effect remains the same, making it uneconomical and impractical.

As the resin coating for forming such a conductive corrosion prevention layer, a coating made of, for example, a thermoplastic resin, a thermosetting resin, an electron beam curable resin, or an ultraviolet curable resin is used, such as an acrylic resin-based coating. , styrene resin system, acrylic-styrene copolymer, vinyl chloride resin system, vinyl acetate resin system, vinyl chloride-vinyl acetate copolymer, polyamide resin system, polyvinyl-butyral copolymer, polycarbonate resin system, nitrocellulose resin system , cellulose acetate resin system, urethane resin system, urea resin system, melamine resin system, urea-melamine resin system, epoxy resin system,
Resin paints made of alkyd resins, aminoalkyd resins, rosin-modified maleic acid resins, etc. alone or in combination, include total bending powders (silver, copper, aluminum, nickel, etc.), nonmetallic powders (amorphous carbon, graphite), A conductive material such as a metal oxide such as tin oxide or indium oxide may be added or mixed therein. The amount of conductive material added is appropriately determined depending on the degree of electrical conductivity expected of the adhesive.

There is no particular limit to the thickness of the conductive adhesive layer, but
A range of 20 μs is preferable. If the thickness is less than 51 μs, sufficient adhesive strength cannot be obtained and the resistance value is high, making it impractical. On the other hand, if the thickness exceeds 20 μs, solvent may remain or be used during various subsequent processing steps. This is of no practical use because it may cause the conductive adhesive layer (5) to become fluidized, thereby interfering with the flow of the process.

The conductive corrosion prevention layer can be formed by applying the resin paint to form the conductive corrosion prevention layer using well-known general methods such as roll coating, gravure coating, reverse coating, spray coating, dip coating, etc. Apply by standard coating method and dry (thermosetting resin).

In the case of electron beam curable resins, ultraviolet ray curable resins, etc., this can be done by curing), or it can also be done by laminating a pre-formed film.

Example 1 Holes (hole diameter 100 μs, hole distribution density 10
Aluminum was deposited on both sides of a perforated film with 70,000 holes/m" perforated by high frequency heating vacuum deposition method to a thickness of 70 mm on each side.
A conductive sheet of the present invention was obtained by forming an n- metal vapor deposition layer.

The obtained conductive sheet is suitable for use as a shielding material, for example, and has conductivity on both sides, allowing easy grounding. Also, its shield effect is 55d in SOOMIIz.
B (the same applies hereinafter for TtL field waves).

Example 2 A polyethylene terephthalate film with a thickness of 125 μs was perforated with holes (diameter of 250-1 holes, distribution density: 300,000/2) using a hot needle.The surface of the perforated film was coated with metal using a water-soluble paint. A vapor-deposited layer was applied to areas that did not require it, and a figure with a thickness of 3 μs was drawn. Next, aluminum was vapor-deposited using a high-frequency heating vacuum evaporation method on the surface on which the figure was drawn, to a thickness of 70 μs.
A metal vapor deposited layer of n■ was formed, and then washed with water to dissolve and remove the pattern of the water-soluble paint and the metal vapor deposited layer on its surface to form a metal vapor deposited layer with a desired pattern. A conductive sheet of the present invention was obtained by depositing aluminum using a high frequency heating vacuum deposition method to form a metal deposited layer with a thickness of 70 nm.

The obtained conductive sheet is suitable for use as a substrate for coating liquid crystals, viologen, etc., and has conductivity on both sides, so by passing a current through it from the opposite side to the side coated with liquid crystal, viologen, etc., the liquid crystal molecules are aligned. However, viologen is reduced by electron injection from the electrode and changes color from colorless to blue to purple, so it can be used for signboards, cutting sheets, battery checkers, etc.

Implementation N3: A polyethylene terephthalate film with a thickness of 188 μs was made with holes (diameter of 600-1 holes, distribution density: 500,000/2) using a laser, and nickel was deposited on both sides of the perforated film using a sputtering deposition method. Then, metal vapor deposited layers each having a thickness of 60 nm were formed to obtain a conductive sheet of the present invention.

Since the obtained conductive sheet has conduction between both surfaces, it is suitable for use in, for example, a laminated printed circuit board.

Comparative Example 1 A polyethylene terephthalate film with a thickness of 38 μs was used in the same manner as in Example 1, except that no holes were formed, and aluminum was vapor-deposited on both sides of the film by high-frequency heating vacuum evaporation method. A double-sided metal-deposited sheet was obtained by forming a metal-deposited layer.

The obtained double-sided metal vapor-deposited sheet was used, for example, as a shielding material, and its effectiveness was 40 dB at 500 MHz. Furthermore, since there is no conductivity between both surfaces, grounding is complicated.

The relationship between the conductivity between both surfaces of the obtained conductive sheet of the present invention, the diameter of the pores, the distribution density of the pores, the thickness of the film, and the thickness of the metal vapor deposited layer is as shown in Tables 1 to 4. there were. Table 1 shows the distribution density of pores (10,000/12) and the conductivity between both surfaces (Ω) when the film thickness, metal vapor deposition layer thickness, and pore diameter are constant for 25 μs, 80 μs, and 100 μs, respectively.
Table 2 shows the relationship between film thickness, Kanai vapor M layer thickness, and pore distribution density of 25 μs and 80 μs, respectively.
n■.

900,000/proverb 2 Table 3 shows the relationship between the diameter (trend) of the pores and the conductivity between both surfaces (Ω/cm') at a constant value. distribution density or 25 μs each,
Table 4 shows the relationship between the thickness of the metal vapor deposited layer (n■) and the conductivity between both sides (Ω/C■2) at a constant value of 900,000 pieces/party 2. , pore diameter, and pore distribution density are 80n■, 100μs, and 900,000 pieces/■, respectively! Film thickness (μs) and conductivity between both sides (Ω/
Measurement of the relationship between C and 2) [Effects of the invention] Example 1. As explained in Example 2, Example 3, and Comparative Example 1, according to the present invention, a completely novel and excellent conductive sheet having conductivity between the front and back surfaces can be obtained.

No. No. table table Table 1 No. table

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the basic structure of the conductive sheet of the present invention, and FIG. 2 is a cross-sectional view showing the structure of another embodiment of the conductive sheet of the present invention. (Numbers in drawings) (1) Two base materials (2): Through hole (3): Metal vapor deposited layer G4): Inner wall (5): Conductive adhesive layer Fig. 1

Claims (1)

[Claims] 1 A metal vapor deposited layer is formed on both the front and back surfaces of a base material having a through hole, a metal vapor deposited layer is also formed on the inner wall of at least a part of the through hole, and the metal vapor deposited layer on both the front and back surfaces is formed. A conductive sheet that is electrically connected through through holes.