JP2001358496A - Electromagnetic-wave shielding plate and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic-wave shielding plate which can be manufactured simply even when it is large-sized and whose electromagnetic-wave shielding property and visibility are superior. SOLUTION: In one electromagnetic-wave shielding plate, a conductive geometric pattern is formed on a transparent substrate (1). The geometric pattern is constituted of an innermost layer (21) which is formed of a resin composition containing a metal and/or an inorganic substance, a first conductive layer (22) which is formed on the surface of the innermost layer by an electroless plating operation, and a second conductive layer (23) which is formed on the surface of the first conductive layer by an electroless plating operation. In another electromagnetic-wave shielding plate, a geometric pattern is lattice-shaped, and it is constituted of an innermost layer which is formed of the resin composition by a printing operation in such a way that the direction of its lattices is at 5 to 85 deg. to a printing direction, and a conductive layer which is formed on the surface of the innermost layer by a plating operation. The shielding plates are useful as a front plate for a display. Also a manufacturing method for the shielding plates is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shield plate and a method for manufacturing the same.

[0002]

2. Description of the Related Art Electromagnetic wave shielding plates are widely used as front protection plates mounted on the front of a display, for example, to shield electromagnetic waves leaking from the front side of the display. The electromagnetic wave shielding plate used as the front protection plate is required to not only reduce the electromagnetic wave but also not to reduce the visibility of the display screen of the display.

[0003] As such an electromagnetic wave shield plate, there is known an electromagnetic wave shield plate provided with a lattice-like geometric pattern (2) on the surface of a transparent substrate (1) as shown in Figs. FIG.
Is a schematic plan view of an electromagnetic wave shielding plate having a general lattice pattern, and FIG. 2 is a schematic side view of the same.

[0004] Geometric patterns (2) shown in these figures
Is formed, for example, by attaching a conductive mesh to the transparent substrate (1). The conductive mesh is formed by knitting conductive fibers in a lattice shape. As the conductive fibers, for example, a polyester fiber or the like having a metal thin film formed on the surface thereof is used. However, the electromagnetic wave shielding plate using such a conductive mesh needs to use a knitted conductive mesh in a manufacturing process, and since it easily expands and contracts, there is a problem that its handling is not easy. Was. When an electromagnetic wave shielding plate is used as a front protective plate, it is necessary to increase the transmittance of visible light.To do so, it is necessary to increase the lattice spacing of the conductive mesh and reduce the fiber diameter. Therefore, it was necessary to use a conductive mesh which is more easily stretched and contracted and which is difficult to handle. Further, such a conductive mesh that easily expands and contracts has a problem that it tends to be accompanied by a shift in lattice spacing and a distortion of a lattice pattern when being bonded to a transparent substrate.

[0005] In order to solve such a problem, it is conceivable to attach an etching sheet in which a metal foil is etched in a lattice shape to the surface of the transparent substrate (1). However, in order to manufacture a front panel applied to a display having a large screen size such as a plasma display or a large cathode ray tube (CRT) by using an etching sheet, a large-area metal foil corresponding to the screen size is formed in a lattice shape. However, this requires a large-scale photolithography step, and thus cannot be said to be a method that can be easily manufactured.

On the other hand, Japanese Patent Application Laid-Open Nos. Sho 62-57297 and
JP-52499A proposes an electromagnetic wave shielding plate formed by printing a conductive paint in a grid or stripes. The electromagnetic wave shielding plates described in these publications have a lattice spacing of 1,
Approximately 000 μm and a line width of approximately 100 μm, the electromagnetic wave shielding property was not always sufficient, and the visibility was insufficient because the grid lines were easily visible.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electromagnetic wave shielding plate which can be easily manufactured even if it is large in size, and is excellent in electromagnetic wave shielding property and visibility. As a result of the research, an electromagnetic wave shielding plate formed by providing a geometric pattern made of a resin composition on a transparent base material, further providing a conductive plating layer on the surface of the geometric pattern, and combining them in a predetermined form The present invention has been found to have excellent electromagnetic wave shielding properties and excellent performance with almost no appearance defects such as uneven plating, and completed the present invention.

[0008]

That is, according to the present invention, from a first aspect, there is provided an electromagnetic wave shielding plate having a conductive geometric pattern formed on a transparent substrate, wherein the geometric pattern is formed. , An innermost layer formed from a resin composition containing a metal and / or an inorganic substance, a first conductive layer provided on the surface of the innermost layer by an electroless plating method, and an electrolytic coating on the surface of the first conductive layer. An electromagnetic wave shield plate provided by a second conductive layer provided by a plating method is provided, and from a second viewpoint, an electromagnetic wave shield plate in which a conductive geometric pattern is formed on a transparent substrate. hand,
The geometric pattern is a grid, so that the direction of the lines constituting the grid forms an angle of 5 to 85 ° with the printing direction,
Provided is an electromagnetic wave shield plate including an innermost layer formed by a printing method from a resin composition containing a metal and / or an inorganic substance, and a conductive layer provided on a surface of the innermost layer by a plating method.

Further, according to the present invention, there is provided a front panel for a display comprising any one of these electromagnetic wave shielding plates. Also, a geometric pattern is provided on a transparent substrate using a resin composition containing a metal and / or an inorganic substance, and then subjected to an electroless plating treatment to form a first conductive layer on the surface of the geometric pattern. A method for producing an electromagnetic wave shielding plate specified from the first aspect by further performing electrolytic plating to form a second conductive layer on the surface of the first conductive layer, And a resin composition containing a metal and / or an inorganic substance, and printed on a transparent substrate such that the direction of lines constituting the grid forms an angle of 5 to 85 ° with the printing direction, thereby forming a grid-like geometric shape. A method is also provided for producing an electromagnetic wave shielding plate specified from the second aspect by forming a geometric pattern and then performing a plating treatment to form a conductive layer on the surface of the geometric pattern.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electromagnetic wave shielding plate according to the present invention has a transparent base material (1) provided with a conductive geometric pattern (2), as in the case shown in FIGS. .
The transparent substrate (1) can be used without any particular limitation as long as it is a transparent substrate that can be arranged on the front surface of the display. For example, a glass substrate or a synthetic resin substrate can be used. Examples of the synthetic resin substrate include an acrylic resin plate, a polycarbonate resin plate, a polyester resin plate such as a polyethylene terephthalate plate, a polyolefin resin plate such as a polyethylene plate and a polypropylene plate, and a polyether sulfone plate. The electromagnetic wave shielding plate of the present invention is usually used by being mounted on the front surface of a flat display such as a plasma display panel. In this case, the thickness of the transparent substrate (1) is usually about 0.5 to 20 mm,
Preferably, it is in the range of about 1 to 10 mm. Further, as another usage form, it can be used by directly bonding to the front glass of the display with an adhesive or the like. In this case, the transparent substrate (1) is preferably flexible and has a thickness of usually about 0.02 to 2 mm, preferably 0.1.
About 1 mm.

[0011] In the electromagnetic wave shield plate of the present invention, a conductive geometric pattern is provided on the surface of the transparent base material.
This conductive geometric pattern may be provided directly on the surface of the transparent substrate, or may be provided by bonding a film provided with the conductive geometric pattern to the surface of the transparent substrate. Good. When providing a conductive geometric pattern on the film, as the film used therefor, for example, a polyester resin film such as a polyethylene terephthalate film, a polyolefin resin film such as a polyethylene film or a polypropylene film, a polycarbonate resin film And a synthetic resin film such as a poly (meth) acrylate-based resin film, the thickness of which is usually in the range of about 0.04 to 0.3 mm.

The transparent substrate used in the present invention may be colored with a coloring agent such as a dye or a pigment. Coloring is often used to enhance the legibility of the display. The transparent substrate may contain other additives.For example, when the electromagnetic wave shielding plate is used as a front plate of a plasma display panel, it absorbs near infrared rays generated from the front of the panel. May be contained. When a synthetic resin plate is used as the transparent substrate, a hard coat layer may be provided on the surface thereof. Such a transparent substrate may be a single plate as a single layer, or may be a laminated plate composed of two or more identical or different layers.

The conductive geometric pattern provided on the surface of the transparent substrate is obtained by forming an innermost layer in advance using a resin composition and forming a conductive layer on the surface by plating. The resin composition used to form the innermost layer contains metal particles and / or inorganic particles and a binder,
Metal particles and / or inorganic particles are dispersed in a binder. As the metal particles, for example, particles of silver, an alloy containing silver, gold, nickel, aluminum, or the like can be used. Usually, silver particles having a particle diameter of about 0.1 to 3 μm and flaky silver having a length of about 1 to 20 μm are preferably used. On the other hand, as the inorganic substance, for example, various metal oxides such as iron oxide and titanium oxide can be used.

Examples of the binder include polyester resins, epoxy resins, acrylic resins, phenol resins and the like. Such a binder may be uncolored or colored. When particles that easily reflect visible light, such as silver particles and nickel particles, are used as the metal particles, the side on which the geometric pattern is provided is the display side, and the opposite side is the viewer side. If the scenery is reflected on the back side of the geometric pattern, and the side where the geometric pattern is provided is the viewer side and the opposite side is the display side, the screen displayed on the display will be the geometric pattern May be reflected on the back surface and reflected on the display. Therefore, if the binder is made black, it is possible to suppress the reflection of visible light due to the geometric pattern. To make the binder black, a colorant such as a black dye or pigment may be mixed with the binder. As a black pigment,
For example, carbon, iron oxide, titanium black, or the like can be used.

The ratio of the metal particles and / or the inorganic substance to the binder in the resin composition is determined in accordance with the desired electrical resistance of the geometric pattern, the adhesive strength to the transparent substrate, and the like.
It is appropriately selected. If the amount of metal particles used is small,
Although the adhesive strength with the transparent substrate increases, the conductive resistance increases. Conversely, when the amount of the binder used is small, the adhesive strength with the transparent substrate decreases instead of reducing the conductive resistance. This resin composition may contain other additives, similarly to the ordinary resin composition. Usually, the resin composition is used by mixing with a solvent and adjusting the viscosity.

The geometric pattern of the electromagnetic wave shielding plate of the present invention may be any of the squares shown in FIG. 1, triangles including equilateral triangles, isosceles triangles, right triangles, etc., rectangles, parallelograms, rhombuses, trapezoids and the like. Includes other n-gons (n, including squares, hexagons, octagons, dodecagons, etc.)
Is an integer of 5 or more), a circle, an ellipse, a three-leaf shape, a petal shape, a star shape, or the like, and a pattern composed of any of these alone or a combination of two or more of these can be used. it can.

Such a conductive geometric pattern may be provided on both sides of the substrate, but is usually provided on one side. In order to provide a geometric pattern on the surface of the transparent substrate, for example, the resin composition may be printed so as to form a geometric pattern. According to the printing method, it is possible to suppress a shift in line interval and a distortion of a geometric pattern, which are likely to occur when a conductive mesh is provided, and to manufacture an electromagnetic wave shielding plate having a large area.

A method for printing a geometric pattern is as follows.
Offset printing methods such as intaglio offset printing, letterpress offset printing, lithographic offset printing, and stencil offset printing, as well as screen printing and gravure printing are applied. Above all, the offset printing method is preferable in that the lines constituting the geometric pattern can be provided without being disconnected in the middle. The offset printing method is 4
Even in the case of a geometric pattern having a small line width of 0 μm or less, it is preferable in that the geometric pattern can be provided without disconnection in the middle. In particular, the intaglio offset printing method is preferable in that a thick pattern is easily formed. Is more preferred.

In the electromagnetic wave shielding plate of the present invention, as shown in an enlarged schematic sectional view of FIG. 3, a resin composition provided on a transparent substrate (1) in order to enhance the ability to effectively shield electromagnetic waves. A conductive layer (22, 23) made of metal is provided on the surface of the innermost layer (21) made of an object. Examples of the metal constituting the conductive layer include copper, nickel, and the like. The metal layer may be a single layer, or may be a multilayer including two, three, or more layers. Top layer (2
3) The black layer suppresses the reflection of visible light,
It is preferable to enhance visibility. The thickness of the metal layer is usually 20 μm or less, preferably 5 μm or less, and usually 0.1 μm or more.

In a first aspect of the present invention, a first conductive layer (22) is provided on the surface of the innermost layer (21) by electroless plating, and a first conductive layer (22) is formed thereon by electrolytic plating at a predetermined thickness. A second conductive layer (23) is provided. First, a first conductive layer (22) having uniform conductivity is provided over the entire innermost layer (21) by electroless plating, and then the second conductive layer (23) having a desired thickness is formed by electrolytic plating. ) Makes it possible to form a conductive layer having a uniform thickness over a large area. The conditions of the electroless plating and the electrolytic plating are appropriately selected according to the physical properties of the resin composition used and the target performance of the obtained electromagnetic wave shielding plate.

When a geometric pattern is formed on a transparent base material by using a printing method, the line width of the obtained geometric pattern tends to be different between a direction parallel to the printing direction and a direction perpendicular to the printing direction. This is especially true in the case of a lattice pattern. Here, the printing direction means a driving direction of an inking roller, a squeegee, a doctor blade, a blanket cylinder and the like in a printing machine, in other words, a moving direction of a printing resin composition (ink). In the grid pattern, if the line width is different between the direction parallel to the printing direction and the direction perpendicular to the printing direction, a difference in conductivity occurs when providing a conductive layer by electrolytic plating, which is not preferable because it causes plating unevenness. The difference in conductivity due to the difference in line width becomes more pronounced as the specified line width is smaller. In order to reduce unevenness in line width due to the printing direction, it is preferable to design the grid pattern so that the printing direction differs from the grid direction.

In view of the above, in the second aspect of the present invention, when forming a grid-like geometric pattern on a transparent substrate from a resin composition by a printing method, the direction of the lines constituting the grid is the same as the printing direction. Make an angle in the range of ゜ to 85 °. Preferably, the direction of the lines constituting the grid and the printing direction are 10 ° to 70 °. Here, the direction of the line forming the grid means the smaller of the angles formed by the graticule of the grid and the printing direction.

FIG. 4 is a schematic plan view showing one embodiment of this case. In this example, a blanket cylinder (3) in which a resin composition for printing is held in a predetermined shape is rotationally imprinted on a transparent substrate (1), and a grid-like geometry is formed on the transparent substrate (1). In providing the pattern (2), the direction of printing by the blanket cylinder (3) indicated by the arrow and the direction of the line of the grid (2) make an angle of about 45 °. FIG. 4
Then, the resin composition for printing is held on the surface of the blanket cylinder (3) at right angles to the oblique direction, and this is rotationally imprinted in a direction perpendicular to the short side of the transparent substrate (1).
Although an oblique lattice is formed on the transparent substrate (1), the present invention is not limited to this. For example, the resin composition is held on the surface of the blanket cylinder (3) in a direction perpendicular to the oblique direction, and the resin composition is rotationally stamped in the oblique direction with respect to the transparent substrate (1).
It is also possible to form a grid substantially parallel to each side of the above, in other words, a grid substantially similar to that shown in FIG.

Note that, depending on the printing method, the step of driving the squeegee or the doctor blade appears multiple times, and as a result, the printing direction may be plural. Taking an intaglio offset printing method as an example, first, printing ink was filled using a squeegee on an intaglio having a pattern to be printed, and then excess ink on the intaglio was scraped off with a doctor blade, and then a blanket was wound. The ink filled in the intaglio is transferred onto the blanket by rolling the blanket cylinder onto the intaglio, and then the blanket cylinder is rolled onto the substrate to be printed, and the ink on the blanket is transferred onto the substrate. It has a series of steps. The driving directions of the squeegee, doctor blade, and blanket copper described above are usually designed to be on the same straight line, but may be designed to be driven in a different direction as necessary. In a series of printing steps, when the driving directions of the squeegee and the doctor blade are designed to be different, the direction of the lattice pattern may be optimized mainly on the step that most affects the unevenness of the line width. For example, when scraping the ink on the intaglio with a doctor blade, by using an intaglio having a grid pattern formed at an angle of 5 ° to 85 ° with respect to the driving direction of the doctor blade, By adjusting the scraping direction so that the doctor blade forms a predetermined angle, the same effect as in the case where the predetermined angle is provided in the driving direction of the blanket cylinder and the direction of the lattice pattern described above can be achieved. it can.

As described above, when printing is performed at an angle so that the direction of the grid lines and the printing direction are different, unevenness in the line width of the grid pattern due to the printing direction is reduced.
It is not always necessary to provide two conductive layers by electroless plating and electrolytic plating on the surface of the formed innermost layer, and a single conductive layer may be provided. In this case, the conductive layer may be formed by any method of electrolytic plating and electroless plating. Of course, even in the case of printing at an angle such that the direction of the grid line and the printing direction are different in this way, as in the case of specifying from the first viewpoint described above, it was formed from the resin composition. It is also effective to provide a first conductive layer by electroless plating on the surface of the innermost layer, and to provide a second conductive layer by electrolytic plating thereon.

In any case specified from the first viewpoint and the second viewpoint, the outermost surface of the geometric pattern is formed as a black layer, which suppresses reflection of visible light and improves visibility. Above. To make the outermost surface a black layer, a method of coating with a black metal layer or a black electrodeposition layer,
An oxidation or sulfidation method can be employed. To cover with a black metal layer, for example, black nickel plating treatment, chromate plating treatment, black ternary alloy plating treatment using tin, nickel and copper, black ternary alloy plating treatment using tin, nickel and molybdenum, etc. I just need. The black electrodeposition layer is a black layer provided by electrodeposition, and can be provided by, for example, electrodeposition coating using a black paint in which a black pigment is dispersed in an electrodeposition resin. Examples of the black pigment include carbon black and the like, and a conductive black pigment is preferable.
The electrodeposition resin may be an anionic resin or a cationic resin, and specifically, an acrylic resin,
These electrodeposition resins, such as polyester resin and epoxy resin, can be used alone or in combination of two or more. Further, the metal surface can be blackened by an oxidation treatment or a sulfuration treatment. The oxidation treatment and the sulfidation treatment can be performed by a known method.

As described above, the geometric pattern in the electromagnetic wave shielding plate of the present invention is constituted by the line in which the conductive layer by plating is provided on the surface of the innermost layer made of the resin composition.
The lines forming the conductive grid pattern are usually about 100 to 500 μm in width and usually about 10 to 80 μm in width with the conductive layer provided. Preferably, the line spacing is about 125-500 μm and the line width is about 10-40
μm. If the distance between the lines is larger than 500 μm, the geometric pattern tends to be noticeable and the visibility of the display screen tends to decrease. On the other hand, if it is smaller than 100 μm, the geometric pattern becomes finer and the transmittance of visible light is reduced. And the display screen tends to be dark.
Also, when the line width exceeds about 80 μm, the grid pattern tends to be noticeable and the visibility of the display screen tends to decrease, and a conductive geometric pattern having a line width smaller than about 10 μm should be provided. The line width is usually 10 μm or more. Preferably, the thickness of the line is about 1 μm or more, and usually about 30 μm or less. If the thickness is less than about 1 μm, the shielding of electromagnetic waves tends to be insufficient. When adjusting the line spacing to make the brightness (light transmittance) the same, printing becomes difficult. However, the electromagnetic wave shielding ability increases when the line width is reduced to about 40 μm or less and the line spacing is reduced. It is preferred. In the case of a pattern other than a square, the line interval is a value converted into a square, which is obtained from the measured values of the line width and the light transmittance.

The electromagnetic wave shielding plate of the present invention may have a functional film laminated thereon. Examples of the functional film include, for example, an antireflection film provided with an antireflection layer for preventing light reflection on the film surface, a colored film colored by a coloring agent or an additive, and a near infrared shielding film that absorbs or reflects near infrared light. And antifouling films for preventing contaminants such as fingerprints from adhering to the surface.

The electromagnetic wave shielding plate thus obtained has excellent electromagnetic wave shielding properties and visibility, and also has excellent dimensional accuracy of the geometric pattern. Therefore, this electromagnetic wave shield plate is particularly useful as a front plate of a display having a large display screen such as a cathode ray tube (CRT) or a plasma display panel.

[0030]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Parts in the following examples are on a weight basis unless otherwise specified. Further, with respect to the electromagnetic wave shielding plates obtained in some examples, the line width and the electromagnetic wave shielding property were measured by the following methods.

(1) Line width The line width of the sample was measured with a microscope.

(2) Electromagnetic Wave Shielding Property Using an electromagnetic wave shielding effect measuring apparatus [“TR17301 type” manufactured by Advantest Co., Ltd.] and a network analyzer [“8753A” manufactured by Hewlett-Packard Company) at a frequency of 1 MHz to 1 GHz. The intensity of the electromagnetic wave was measured, and the value calculated by the following equation was defined as the electromagnetic wave shielding property.

Electromagnetic wave shielding property (dB) = 20 × log ₁₀ (X ₀ / X) In the equation, X ₀ represents the intensity of the electromagnetic wave when the electromagnetic wave shielding plate is not used, and X is the electromagnetic wave when the electromagnetic wave shielding plate is used. Indicates strength.

The measurement was carried out using a test piece in which a square sample having a side of 200 mm was cut out from the obtained electromagnetic wave shielding plate and the ground was formed around the side surface with a copper tape. When the test piece was a film, it was measured by attaching it to an acrylic plate of the same size and 3 mm thick.

The resin compositions used for printing in the respective examples are as follows.

Resin composition A: 800 parts of silver particles as metal particles (“Silcoat AgC-D” manufactured by Fukuda Metal Foil & Powder Co., Ltd., average particle diameter 7.0 μm, flake shape), and oxidized as inorganic particles 90 parts of iron particles were mixed, 60 parts of a polyester resin (manufactured by Sumitomo Rubber Industries, Ltd.) and n-solvent as a solvent.
Resin composition A was prepared by mixing 50 parts of butyl carbitol acetate with a roll disperser and uniformly dispersing particles in a binder. The binder was black-grey due to the iron oxide.

Resin composition B: 800 parts of the same silver particles and 50 parts of iron oxide particles as used in resin composition A were mixed, and 100 parts of the same polyester resin as used in resin composition A were mixed with the mixture. And 50 parts of n-butyl carbitol acetate as a solvent mixed with a roll disperser to uniformly disperse the particles in a binder, to obtain a resin composition B
And The binder was black-grey due to the iron oxide.

Resin composition C: 890 parts of the same silver particles as used in Resin composition A and 0.9 parts of a black colorant ("DJ-600" manufactured by Degussa, Inc.) are mixed. ,
Into this, 60 parts of the same polyester resin as used for the resin composition A and 50 parts of n-butyl carbitol acetate as a solvent were mixed with a roll disperser to uniformly disperse the particles and the colorant in the binder. The resin composition C
And The binder was blackened by the colorant (carbon).

Example 1 On a polyester film having a size of 650 mm × 1,000 mm and a thickness of 100 μm, the resin composition A was used, and an intaglio offset printing method was used to obtain a lattice spacing of 200 μm and a line width of 22 μm.
m grid patterns were provided. The two films with the lattice pattern were degreased by immersion in a 50 g / L solution of a degreasing agent “A-screen A-220” (manufactured by Okuno Pharmaceutical Co., Ltd.) kept at 50 ° C. for 10 minutes, and then 100 cc / l It was immersed in an aqueous solution of sulfuric acid for about 30 seconds at room temperature. This is immersed in a catalyst solution for electroless plating "TMP Activator" (200 ml / L concentration, manufactured by Okuno Pharmaceutical Co., Ltd.) at room temperature for 5 minutes, and then a catalyst reduction solution "OPC 150 Cryster" [Okuno Pharmaceutical Co., Ltd.] Immersed in a 150 ml / L concentration manufactured by Co., Ltd.] for 5 minutes at room temperature, and then electroless plating solution “OPC 750” [Okuno Pharmaceutical
(Concentration: 100 ml / L) manufactured at room temperature for 10 minutes to form a copper film on the pattern surface. Next, 100cc
/ L sulfuric acid aqueous solution at room temperature for about 30 seconds, 70 g of copper sulfate pentahydrate, 200 g of sulfuric acid and ion-exchanged water were mixed and immersed in a 1 liter copper plating solution at room temperature.
Electroplating treatment was performed at 1.7 V for 5 minutes. further,
500 ml of "BKN-Conch" (trade name, manufactured by Murata Co., Ltd.)
It was immersed in a black nickel plating solution composed of L solution at a temperature of 35 ° C., and subjected to electrolytic plating at 1.4 V for 5 minutes. Table 1 shows the evaluation results of the obtained electromagnetic wave shielding plates.

Example 2 One polyester film having a lattice pattern similar to that used in Example 1 was subjected to electroless copper plating in the same manner as in Example 1, and the electrolytic copper plating conditions were changed to 1 Electrolytic copper plating was performed in the same manner as in Example 1 except that the voltage was changed to 0.8 V for 5 minutes. Thereafter, using a stainless steel plate as a cathode and a printed film as an anode, the surface was blackened by anodic oxidation to produce an electromagnetic wave shield plate. Anodization is performed in a 200 g / L aqueous sodium hydroxide solution at 50
The treatment was performed at 1.5 ° C for 5 minutes. Table 1 shows the evaluation results of the obtained electromagnetic wave shielding plates.

Example 3 On a polyester film having a size of 480 mm.times.950 mm and a thickness of 100 .mu.m, the resin composition B was used, and an intaglio offset printing method was used to obtain a grid spacing of 200 .mu.m and a line width of 22 .mu.m.
Grid pattern was provided. The direction of the grid was 0 ° with respect to the side of the film. In the printing process, the direction of scraping the ink from the intaglio plate and the direction of transferring the ink from the blanket cylinder to the film were parallel to the long side of the film. An electromagnetic wave shield plate was produced in the same manner as in Example 1 except that one obtained film with a lattice pattern was used and the conditions of electrolytic copper plating were changed to 1.0 V for 5 minutes. Table 1 shows the evaluation results of the obtained electromagnetic wave shielding plates.

Example 4 On a polyester film having a size of 500 mm × 500 mm and a thickness of 100 μm, using a resin composition C, an intaglio offset printing method was used to obtain a lattice spacing of 200 μm and a line width of 17 μm.
Grid pattern was provided. The direction of the grid was 0 ° with respect to the side of the film. In the printing process, the direction of scraping the ink from the intaglio plate and the direction of transferring the ink from the blanket cylinder to the film were parallel to the long side of the film. Film 2 with lattice pattern thus obtained
An electromagnetic wave shielding plate was produced in the same manner as in Example 1 except that the sheets were used and the conditions for electrolytic copper plating were 1.5 V for 5 minutes. Table 1 shows the evaluation results of the obtained electromagnetic wave shielding plates.

Comparative Example 1 An electromagnetic wave shielding plate was produced in the same manner as in Example 3, except that the copper film was formed only by the electrolytic plating step. Table 1 shows the evaluation results of the obtained electromagnetic wave shielding plates.

Comparative Example 2 An electromagnetic wave shielding plate was produced in the same manner as in Example 4 except that the copper film was formed only by the electrolytic plating step. Table 1 shows the evaluation results of the obtained electromagnetic wave shielding plates.

Example 5 On a polyester film having a size of 500 mm × 500 mm and a thickness of 100 μm, the resin composition B was used and the intaglio offset printing method was used to perform a grid spacing of 200 μm and a line width of 14 μm.
Grid pattern was provided. The direction of the grid was 45 ° with respect to the side of the film, and in the printing process, the direction of scraping the ink from the intaglio and the direction of transferring the ink from the blanket copper to the film were parallel to the long side of the film. . Two pieces of the thus-obtained polyester film with a lattice pattern were degreased by immersing in a 50 g / L aqueous solution of a degreasing agent “A-screen A-220” (manufactured by Okuno Pharmaceutical Co., Ltd.) maintained at 50 ° C. for 5 minutes. Thereafter, it was immersed in a 100 cc / L sulfuric acid aqueous solution at room temperature for 2 minutes. Next, 70 g of copper sulfate pentahydrate, 200 g of sulfuric acid and ion-exchanged water were mixed and immersed in a 1 liter copper plating solution at room temperature.
For 5 minutes. Then, "BKN-
Immersion at a temperature of 35 ° C. in a black nickel plating solution consisting of a 500 ml / L solution of Konku (trade name, manufactured by Murata Co., Ltd.)
Electroplating was performed at 1.5 V for 5 minutes. Table 1 shows the evaluation results of the obtained electromagnetic wave shielding plates.

Example 6 On a polyester film having a size of 500 mm × 500 mm and a thickness of 100 μm, using a resin composition C, an intaglio offset printing method was used to obtain a lattice spacing of 200 μm and a line width of 22 μm.
Grid pattern was provided. The direction of the grid was 10 ° with respect to the side of the film, and the direction of scraping the ink from the intaglio and the direction of driving the blanket cylinder were parallel to the side of the film. 100 from the obtained film
A square sample of mm was cut out, and using two sheets of the film, the conditions of electrolytic copper plating were changed to 1 V for 5 minutes.
Copper plating was performed in the same manner as in Example 5. Table 1 shows the evaluation results of the obtained electromagnetic wave shielding plates.

Example 7 An electromagnetic wave shielding plate was produced in the same manner as in Example 6, except that printing was performed so that the direction of the grid was 20 ° with respect to the direction of scraping the ink from the intaglio and the direction of driving the blanket cylinder. did. Table 1 shows the evaluation results of the obtained electromagnetic wave shielding plates.
Shown in

Example 8 An electromagnetic wave shield plate was produced in the same manner as in Example 6, except that the printing was performed so that the direction of the grid was 45 ° with respect to the direction of scraping the ink from the intaglio and the direction of driving the blanket cylinder. did. Table 1 shows the evaluation results of the obtained electromagnetic wave shielding plates.
Shown in

Comparative Example 3 An electromagnetic wave shielding plate was produced in the same manner as in Example 6, except that the direction of the lattice was parallel to the direction of scraping ink from the intaglio plate and the direction of driving the blanket cylinder. Table 1 shows the evaluation results of the obtained electromagnetic wave shielding plates.

[0050]

[Table 1] 幅 Linewidth Electromagnetic wave shielding plating unevenness 100 MHz 300 MHz ━━━━━━━ ━━━━━━━━━━━━━━━━━━━━━━ Example 1 27μm 51 dB 53 dB None 〃2 26μm 50 dB 55 dB None ３3 23μm 49 dB 50 dB None ４ 4---None Comparative Example 1---No plating at the center 〃 2---Streaks in printing direction ─────────────────── ５ Example 5 16 μm 48 dB 53 dB None 〃 6---None ７ 7---None ８ 8---None Comparative Example 3---In the printing direction Streak-like unevenness ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[0051]

The electromagnetic wave shielding plate of the present invention has excellent electromagnetic wave shielding properties and visibility, and has high accuracy. Further, according to the method of the present invention, a conductive geometric pattern can be formed accurately and simply by a printing method. In particular,
Even an electromagnetic wave shield plate used as a front plate applied to a display having a large display area can be easily manufactured. Therefore, this electromagnetic wave shield plate is useful as a front plate used for a display having a large display screen such as a plasma display panel, in addition to a cathode ray tube (CRT).

[Brief description of the drawings]

FIG. 1 is a schematic plan view of an electromagnetic wave shield plate having a general lattice pattern.

FIG. 2 is a schematic side view of an electromagnetic wave shield plate having a general lattice pattern.

FIG. 3 is an enlarged schematic cross-sectional view of an electromagnetic wave shield plate specified from a first viewpoint in the present invention.

FIG. 4 is a schematic plan view showing a manufacturing process of an electromagnetic wave shield plate specified from a second viewpoint in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transparent base material 2 ... Lattice pattern 3 ... Blanket cylinder 21 ... Innermost layer formed from resin composition 22 ... First conductive layer by electroless plating 23 ... First by electroplating Second conductive layer.

Continued on the front page F term (reference) 5E321 AA04 BB23 BB25 BB32 GG05 GH01 5G435 AA16 BB02 BB06 GG33 HH02 HH12 HH14

Claims (13)

[Claims] 1. An electromagnetic wave shield plate comprising a conductive geometric pattern formed on a transparent substrate, wherein the geometric pattern is formed of a resin composition containing a metal and / or an inorganic substance. An inner layer, a first conductive layer provided on the surface of the innermost layer by electroless plating, and a second conductive layer provided on the surface of the first conductive layer by electrolytic plating. Characteristic electromagnetic wave shielding plate. 2. The electromagnetic wave shield plate according to claim 1, wherein the innermost layer is formed by a printing method using a resin composition. 3. An electromagnetic wave shielding plate having a conductive geometric pattern formed on a transparent substrate, wherein the geometric pattern is in a lattice shape, and a direction of a line constituting the lattice is a printing direction. An innermost layer formed by a printing method from a resin composition containing a metal and / or an inorganic substance so as to form an angle of 5 to 85 °, and a conductive layer provided on a surface of the innermost layer by a plating method. An electromagnetic wave shield plate, characterized in that: 4. The electromagnetic wave shielding plate according to claim 1, wherein the resin composition forming the innermost layer of the geometric pattern contains a black binder. 5. The electromagnetic wave shield plate according to claim 1, wherein the outermost surface of the geometric pattern is covered with a black metal layer or a black electrodeposition layer. 6. The electromagnetic wave shield plate according to claim 1, wherein the outermost surface of the geometric pattern is blackened by an oxidation or sulfurization treatment. 7. The geometric pattern having a line spacing of 100 to 500 μm and a line width of 10 to 80 μm.
An electromagnetic wave shield plate according to any one of the above. 8. A front panel for a display, comprising the electromagnetic wave shield plate according to claim 1. 9. A geometric pattern is formed on a transparent substrate using a resin composition containing a metal and / or an inorganic substance, and then subjected to an electroless plating treatment to form a first conductive layer on the surface of the geometric pattern. Forming a second conductive layer on the surface of the first conductive layer by performing an electrolytic plating process. 10. The method of claim 9, wherein the geometric pattern is formed by printing. 11. Using a resin composition containing a metal and / or an inorganic substance, printing is performed on a transparent base material such that the direction of a line constituting the grid forms an angle of 5 to 85 ° with the printing direction, A method for manufacturing an electromagnetic wave shielding plate, comprising forming a lattice-like geometric pattern, and then performing plating to form a conductive layer on the surface of the geometric pattern. 12. The printing according to claim 10, wherein the printing is performed by offset printing, screen printing, or gravure printing.
The described method. 13. The method according to claim 12, wherein the printing is performed by intaglio offset printing.