JP2009004617A - Transparent base material with electromagnetic wave shielding film, and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent base material with an electromagnetic wave shielding film which has high conductivity and superior transparency and also has a high-precision pattern through a short stage and a low-cost manufacturing processes, and to provide a manufacturing method for the material. <P>SOLUTION: In this transparent base material 10 with the electromagnetic wave shielding film, in which a transparent base material 1 with flexibility, a primer layer 2 formed on the transparent base material 1, a first metal layer 3 formed on the primer layer 2 and having a predetermined pattern, and a second metal layer 4 formed on the first metal layer 3 are unified, the first metal layer 3 is formed by transferring conductive paste onto the primer layer 2, by pressing the primer layer against the transparent base material 1 against the conductive paste on a printing cylinder for gravure printing, and the second metal layer 4 is formed by electrolytic printing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transparent substrate with an electromagnetic wave shielding film and a method for producing the same, and more specifically, is suitably used for various flat panel displays (FDP) such as a plasma display panel (PDP), and has high conductivity and excellent transparency. In addition, the present invention relates to a transparent substrate with an electromagnetic wave shielding film having a high-precision pattern in a short process and an inexpensive manufacturing process, and a method for manufacturing the same.

Conventionally, as a transparent base material with an electromagnetic wave shielding film used for a display such as a CRT, an electromagnetic wave shielding film formed on a transparent base material such as a polyethylene terephthalate (PET) film by a sputtering method or the like can be mentioned. .
As the electromagnetic wave shielding film, a sputter film such as a tin-added indium oxide (ITO) thin film or a silver thin film is used. Moreover, in various flat panel displays (FPD) such as a plasma display panel (PDP), which is a large display which has recently been attracting attention, a higher electromagnetic wave shielding ability is required, so that it is mainly formed on a transparent film. An etching mesh film in which a copper foil is formed into a lattice shape by photolithography is used.

By the way, with the conventional etching mesh film, it is difficult to blacken the front surface, both side surfaces, and the back surface, particularly the side surfaces, and there is a problem in that it adversely affects the contrast of the image when mounted on a display. Therefore, a method of oxidizing and blackening the copper surface of the etching mesh film is mainly used. However, this method has a problem that the surface resistance of the etching mesh film is increased.
In addition, the etching mesh film has many manufacturing processes, and it is difficult to manage the etching conditions, so that there is a problem that the cost is high due to a low yield. In particular, in order to popularize various flat panel displays (FPD) such as plasma display panels (PDP) for consumer use, total cost reduction including manufacturing costs is required, and the electromagnetic shielding film is also low in price. Is required.

Therefore, as a method for obtaining an electromagnetic wave shielding film having high conductivity and high transmittance at a relatively low cost, a paste containing a noble metal catalyst is printed on a transparent film by a screen printing method to form an underlayer of a fine pattern. A method for electroless plating of copper on the underlayer has been proposed (see, for example, Patent Documents 1 and 2).
JP 11-170420 A JP 2003-145709 A

  However, with the conventional screen printing method, an electromagnetic wave shielding film can be obtained relatively easily and at a low cost. However, since the screen printing method itself is sheet-fed printing, the printing speed is limited and further productivity is achieved. There was a problem that it was difficult to improve.

  The present invention has been made in order to solve the above-described problems, and has high conductivity and excellent transparency, and also has an electromagnetic wave shield having a high-precision pattern in a short process and an inexpensive manufacturing process. It aims at providing the transparent base material with a film | membrane, its manufacturing method, and a manufacturing apparatus.

  As a result of intensive studies on a transparent base material with an electromagnetic wave shielding film that can be patterned with high accuracy and a short process, the present inventors have adopted a gravure printing method as a printing method, and a plate for gravure printing. It has been found that an electromagnetic wave shielding film patterned with high precision on a transparent substrate can be formed at low cost and at low cost by pressing the primer layer on the transparent substrate for a predetermined time to the conductive paste on the trunk. The present invention has been completed.

  That is, the transparent substrate with an electromagnetic wave shielding film of the present invention is a transparent substrate having flexibility, a primer layer formed on the transparent substrate, a first layer formed on the primer layer and having a predetermined pattern. A transparent substrate with an electromagnetic wave shielding film in which one metal layer and a second metal layer formed on the first metal layer are integrated, wherein the first metal layer is for gravure printing The conductive paste on the plate cylinder is pressed on the primer layer on the transparent substrate to transfer the conductive paste onto the primer layer, and the second metal layer is formed by electrolytic plating. It is formed.

In this transparent base material with an electromagnetic wave shielding film, the first metal layer was transferred onto the primer layer by pressing the primer layer on the transparent base material for a predetermined time onto the conductive paste on the plate cylinder for gravure printing. As a result, the first metal layer has a highly accurate pattern.
Moreover, by transferring the conductive paste on the gravure printing cylinder to the primer layer on the transparent substrate, the pattern accuracy of the electromagnetic wave shielding film becomes high.

  The method for producing a transparent base material with an electromagnetic wave shielding film of the present invention includes a transparent base material having flexibility, a primer layer formed on the transparent base material, and a predetermined pattern formed on the primer layer. A method for producing a transparent base material with an electromagnetic wave shielding film in which a first metal layer and a second metal layer formed on the first metal layer are integrated, and on a plate cylinder for gravure printing A conductive paste containing at least conductive particles, a binder resin and a solvent is applied in a predetermined pattern, and then the conductive paste on the plate cylinder and the primer layer formed on the transparent substrate Press and hold for a predetermined time, and then transfer the conductive paste on the plate cylinder onto the primer layer on the transparent substrate by separating the transparent substrate and the plate cylinder, and then Heat treatment pattern of conductive paste A first metal layer formed Te, and forming the second metal layer by performing electrolytic plating on said first metal layer.

In the method for producing a transparent substrate with an electromagnetic wave shielding film of the present invention, the conductive paste on the plate cylinder applied in a predetermined pattern and the primer layer formed on the transparent substrate are pressed and held for a predetermined time. Then, by separating the transparent substrate and the plate cylinder and transferring the conductive paste on the plate cylinder onto the primer layer of the transparent substrate, a short process and an inexpensive manufacturing process High-accuracy patterning of the electromagnetic shielding film becomes possible.
Thereby, the transparent base material with the electromagnetic wave shielding film which has a high electroconductivity, the outstanding transparency, and a highly accurate pattern can be manufactured in a short process and an inexpensive manufacturing process.

The holding time is preferably 0.5 seconds or more and 10 seconds or less.
For the primer layer, a primer-forming paint containing oxide fine particles, a binder resin, and a solvent, and having an oil absorption amount of 0.5 ml / g or more and a specific surface area of 50 m ² / g or more is used. It is preferable to form them.

According to the transparent substrate with an electromagnetic wave shielding film of the present invention, a transparent substrate having flexibility, a primer layer formed on the transparent substrate, and a first layer formed on the primer layer and having a predetermined pattern. A transparent substrate with an electromagnetic wave shielding film in which one metal layer and a second metal layer formed on the first metal layer are integrated, wherein the first metal layer is for gravure printing The conductive paste on the plate cylinder is pressed on the primer layer on the transparent substrate to transfer the conductive paste onto the primer layer, and the second metal layer is formed by electrolytic plating. Since it forms, the pattern of the 1st metal layer which consists of an electrically conductive paste can be made highly accurate, and the pattern precision of an electromagnetic wave shielding film can be made highly accurate.
Therefore, a transparent substrate with an electromagnetic wave shielding film having high conductivity, excellent transparency, and a high-accuracy pattern can be easily realized.

According to the method for producing a transparent substrate with an electromagnetic wave shielding film of the present invention, a transparent substrate having flexibility, a primer layer formed on the transparent substrate, and a predetermined pattern formed on the primer layer A method for producing a transparent base material with an electromagnetic wave shielding film in which a first metal layer having a first metal layer and a second metal layer formed on the first metal layer are integrated, and a plate for gravure printing On the cylinder, a conductive paste containing at least conductive particles, a binder resin and a solvent is applied in a predetermined pattern, and then the conductive paste on the plate cylinder and the primer layer formed on the transparent substrate Are pressed and held for a predetermined time, and then the conductive paste on the plate cylinder is transferred onto the primer layer on the transparent substrate by separating the transparent substrate and the plate cylinder, and then The pattern of the conductive paste The first metal layer is formed by treatment, and the second metal layer is formed by electrolytic plating on the first metal layer. Accurate patterning can be performed.
Therefore, a transparent substrate with an electromagnetic wave shielding film having high conductivity, excellent transparency, and a high-precision pattern can be manufactured by a short process and an inexpensive manufacturing process.

The transparent substrate with an electromagnetic wave shielding film of the present invention and the best mode for carrying out the manufacturing method thereof will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

"Transparent substrate with electromagnetic shielding film"
FIG. 1 is a plan view showing an embodiment of a transparent substrate with an electromagnetic wave shielding film of the present invention. FIG. 2 is an enlarged cross-sectional view taken along the line AA in FIG.
1 and 2, reference numeral 1 is a transparent substrate, 2 is a primer layer (underlayer), 3 is a first metal layer (lower metal layer), 4 is a second metal layer (upper metal layer), and 5 is The electromagnetic wave shielding pattern 10 indicates a transparent substrate with an electromagnetic wave shielding film, respectively.

The transparent base material 10 with an electromagnetic wave shielding film of this embodiment is formed on the transparent base material 1, the primer layer 2 formed on the entire main surface 1a of the transparent base material 1, the primer layer 2, and a predetermined pattern. And a second metal layer 4 formed on the first metal layer 3. The transparent base material 1, the primer layer 2, and the first metal layer 3. And the 2nd metal layer 4 is integrated.
The first metal layer 3 and the second metal layer 4 form an electromagnetic wave shielding film 5 having a predetermined pattern.

The first metal layer 3 is formed on the primer layer 2 by pressing the primer layer 2 on the transparent substrate 1 for a predetermined time against the conductive paste on the gravure printing cylinder. Transferred and heat treated.
The second metal layer 4 is formed by electrolytic plating on the first metal layer 3.
For example, the first metal layer 3 and the second metal layer 4 have a lattice shape in which the line width L is 5 μm to 200 μm and the line interval S is 150 μm to 500 μm.

  As the transparent substrate 1, a transparent and flexible film or sheet resin substrate is used. For example, a polyester resin substrate such as polyethylene terephthalate (PET), a polycarbonate resin substrate, a polyamide resin. Examples of the base material include polyolefin resin base materials such as polypropylene (PP) and polyethylene (PE), and acrylic resin base materials.

The primer layer 2 is composed of a composite material containing oxide fine particles and a binder resin.
Examples of the oxide fine particles include metal oxides such as alumina, titania and zirconia, and inorganic oxides such as silica. Two or more kinds of these may be mixed.
As the binder resin, a resin having resistance to a plating bath when the first metal layer 3 is electrolytically plated, for example, a resin having a heat resistance of 40 to 80 ° C. and excellent in chemical resistance can be used. Examples thereof include cellulose derivatives such as ethyl cellulose and propyl cellulose, poly vinyl butyral, acrylic resin, polyurethane resin, rosin ester resin, and the like, and two or more of these may be mixed.

  In particular, if a resin having flexibility such as polyurethane resin is used, the primer layer 2 itself has flexibility, and when the conductive paste is transferred from the cylinder to the primer layer 2 by the gravure printing method, Since the primer layer 2 follows and contacts the pattern groove of the cylinder and is pressed into the pattern groove, the transferability is improved, which is preferable.

The ratio (M / R) of these oxide fine particles (M) to the binder resin (R) is preferably 90/10 to 10/90, more preferably 60/40 to 40/60, by weight.
When the ratio of the oxide fine particles is lower than the above range, the adhesion strength between the primer layer 2 and the transparent substrate 1 is weakened, and the receiving layer when the first metal layer 3 is formed by the gravure printing method. This is because there is a risk of dripping and spreading on the printed conductive paste. On the other hand, if the ratio of the oxide fine particles is higher than the above range, the primer layer 2 and the transparent substrate 1 This is because the adhesion strength is weakened, the transmittance of the obtained transparent base material 10 with an electromagnetic wave shielding film itself is lowered, and haze is increased.

Further, the thickness of the primer layer 2 is preferably 0.5 μm to 10 μm, more preferably 1 μm to 3 μm.
This is because if the thickness of the primer layer 2 is thinner than the above range, the effect as a receiving layer when the first metal layer 3 is formed by the gravure printing method is reduced, whereas the thickness is smaller than the above range. This is because if the thickness is thick, the printed first metal layer 3 may be cracked.

The first metal layer 3 is composed of a composite material containing conductive particles, an organic polymer resin, and a black pigment or thixotropic agent added as necessary.
The conductive particles are added to impart conductivity to the first metal layer 3 so that electroplating is possible.
Examples of such conductive particles were selected from the group of silver (Ag), palladium (Pd), platinum (Pt), gold (Au), ruthenium (Ru), copper (Cu), and nickel (Ni). Examples include fine particles such as metals or alloys containing elements, or oxides. These conductive particles may be used in combination of two or more.

The average particle size of the conductive particles is preferably 0.001 μm to 5 μm, more preferably 0.001 μm to 2 μm.
If the average particle diameter of the conductive particles is less than 0.001 μm, sufficient conductivity cannot be obtained. On the other hand, if the average particle diameter exceeds 5 μm, the first metal layer 3 may not form fine lines. is there.

  The organic polymer resin may be any resin that is suitable for gravure printing and has resistance to an electrolytic plating solution, and examples thereof include ethyl cellulose, rosin ester resin, acrylic resin, polyvinyl butyral resin, and polyurethane resin. These resins may be used in combination of two or more.

Further, the ratio (NM / R) between the conductive particles (NM) and the organic polymer resin (R) is preferably 40/60 to 80/20, more preferably 60/40 to 70/30 in weight ratio. It is.
If the ratio of the conductive particles is lower than the above range, the conductive particles are almost covered with the organic polymer resin, and a surface resistance value (50Ω / □ or less) that enables electrolytic plating cannot be obtained. On the other hand, if the ratio of the conductive particles is higher than the above range, the printability is deteriorated, and the curing of the printed film with the organic polymer resin is insufficient, and the first metal layer 3 and the primer layer 2 This is because adhesion cannot be obtained.

The black pigment is added as necessary to blacken the bottom surface of the electromagnetic wave shielding film 5 having a predetermined pattern in order to improve contrast.
Examples of such a black pigment include carbon black.
In the above composite material, the black pigment content is preferably 0.03% by weight to 3.0% by weight, more preferably 0.1% by weight to 1.0% by weight.
If the black pigment content is less than 0.03% by weight, the blackness of the mesh on the back surface of the printed film is insufficient, and when mounted on the display surface of a display such as a PDP, good contrast cannot be obtained. If the content exceeds 3.0% by weight, the blackness of the mesh on the back surface of the printed film becomes good and good contrast is obtained, but the printability is deteriorated.

The thixotropic agent is added to improve the printability of the conductive paste.
Examples of such thixotropic agents include oxide fine particles having a large oil absorption amount; clay minerals such as organic solvent-soluble bentonite and smectite; organic thixotropic agents.
Here, the oil absorption is a value measured in accordance with JIS K5101 “Pigment Test Method” using a solvent in a conductive paste containing oxide fine particles.
Examples of the oxide fine particles having a large oil absorption include metal oxide fine particles such as alumina, zinc oxide, zirconia, and titania, and inorganic oxide fine particles such as silica. Two or more kinds of these metal oxide fine particles may be mixed and used.

  The second metal layer 4 is for imparting conductivity necessary for shielding electromagnetic waves to the electromagnetic wave shielding film 5, for example, having a one-layer structure composed of an electrolytic copper plating layer or an electrolytic nickel plating layer, Or the thing of the two-layer structure which formed black plating layers, such as a black nickel plating layer, a black chromium plating layer, a nickel-tin alloy plating layer, on an electric copper plating layer is mentioned, for example. In particular, when it is desired to obtain the electromagnetic wave shielding film 5 having a low resistance, a two-layer structure is preferable. This black plating layer can simultaneously blacken the surface and both side surfaces of the second metal layer 4 (electromagnetic wave shielding film 5), and does not lower the conductivity.

Next, the manufacturing method of the transparent base material with an electromagnetic wave shielding film of this embodiment is demonstrated.
"Formation of primer layer"
First, the primer layer 2 is formed by applying a primer layer-forming paint on the transparent substrate 1 by a printing method such as a gravure printing method, a bar coat printing method, or an offset printing method, and then drying.

As the primer layer forming coating material, a coating material containing the oxide fine particles, the binder resin, and an organic solvent is preferably used.
The amount of solid content in the primer layer-forming coating material is not particularly limited, and for example, 10 to 90% by weight is preferable from the viewpoint of coatability.

The oxide fine particles preferably have an oil absorption of 0.5 ml / g or more and a specific surface area of 50 m ² / g or more.
Here, the oil absorption is a value measured in accordance with JIS K5101 “Pigment Test Method” using a solvent in a conductive paste containing oxide fine particles. By including such oxide fine particles, it is possible to promote drying shrinkage due to solvent absorption during printing of the first metal layer 3, thereby strengthening the contact between the particles, and as a result, the first The conductivity of the metal layer 3 can be improved.
On the other hand, when the oil absorption of the oxide fine particles is less than 0.5 ml / g, the drying shrinkage effect is not exhibited and the width of the first metal layer 3 is increased. Further, although there is no particular upper limit on the oil absorption amount of the oxide fine particles, those having an oil absorption amount of 5 ml / g or less are generally preferably used from the viewpoint of availability and handleability.

Further, the specific surface area of the oxide fine particles is preferably 50 m ² / g or more, more preferably 100 m ² / g or more.
When the specific surface area of the oxide fine particles is less than 50 m ² / g, the drying shrinkage effect is small, and the width of the first metal layer 3 is large. In addition, although there is no particular upper limit on the specific surface area of the oxide fine particles, those having a specific surface area of 1000 m ² / g or less are generally preferably used in view of availability and handling properties.
The particle size of the oxide fine particles used is not particularly important, but generally has a relationship with the oil absorption amount and the specific surface area, and the oil absorption amount is 0.5 ml / g or more and the specific surface area is 50 m ² / g or more. As oxide fine particles, there are usually many particles having a primary particle diameter of 0.1 μm or less. A preferable primary particle diameter of the oxide fine particles is in the range of 0.01 μm to 0.1 μm.

The organic solvent only needs to be able to disperse oxide fine particles and dissolve or disperse the binder resin. For example, aromatic hydrocarbons such as toluene and xylene; cyclized aliphatic carbonization such as cyclohexanone. Hydrogen; ketones such as methyl ethyl ketone (MEK); alcohols such as isopropyl alcohol are preferably used.
In order to facilitate dispersion of the oxide fine particles, a phosphate ester-based dispersant or the like may be added to the organic solvent.

  The drying conditions after application of the primer layer-forming coating material are not particularly limited, but in a normal hot air drying, drying is performed at a temperature of 80 ° C. to 160 ° C. for several minutes to sufficiently remove the organic solvent in the coating film. It is desirable to volatilize.

"Formation of the first metal layer"
Next, the first metal layer 3 is formed by applying a conductive paste in a predetermined pattern on the primer layer 2 by a gravure printing method and then performing a heat treatment.

As the conductive paste, a paste containing the above conductive particles, an organic polymer resin, an organic solvent, and a black pigment or thixotropic agent added as necessary is suitably used.
The amount of solid content in the conductive paste is not particularly limited, and for example, 30 to 90% by weight is preferable from the viewpoint of coatability.

  As the organic solvent, it is possible to dissolve or disperse the organic polymer resin and to be suitable for gravure printing. For example, toluene, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), butyl acetate, cyclohexanone, Examples include butyl carbitol, butyl carbitol acetate, and α-terpineol.

The viscosity of the conductive paste is preferably 0.5 Pa · s to 500 Pa · s, more preferably 50 Pa · s to 200 Pa · s.
This is because if the viscosity of the conductive paste is less than 0.5 Pa · s, the thixotropic property of the conductive paste is lost and defects such as stringing occur and a good printed shape cannot be obtained, while the viscosity is 500 Pa · s. This is because the conductive paste cannot be supplied during gravure printing and printing unevenness occurs.

The formation of the first metal layer 3 on the primer layer 2 is performed using the apparatus shown in FIG.
FIG. 3 is a schematic configuration diagram illustrating an example of an apparatus for producing a transparent base material with an electromagnetic wave shielding film used in the method for producing a transparent base material with an electromagnetic wave shielding film of the present embodiment.
In FIG. 3, reference numeral 11 is a cylindrical gravure printing cylinder, 12 is a pattern groove formed on the surface of the plate copper 11, 13 is a dispenser for applying the conductive paste C to the surface of the printing cylinder 11, and 14 is Blades for removing surplus portions other than the pattern grooves 12 in the applied conductive paste C, 15 and 16 are plates for the transparent substrate F for gravure printing in which the primer layer 2 is formed on one main surface of the transparent substrate 1 A backup roll that presses the barrel 11 for a predetermined time.

First, in order to cause the plate cylinder 11 to press the transparent base material F and hold it for a predetermined time, the position of the backup roll 16 is adjusted so as to obtain a fixed holding time according to the printing speed. This holding time is preferably 0.5 or more and 10 seconds or less, more preferably 1 second or more and 5 seconds or less.
When the holding time is less than 0.5 seconds, absorption of the organic solvent contained in the conductive paste C into the primer layer 2 becomes insufficient, and the viscosity of the conductive paste C filled in the pattern groove 12 of the plate cylinder 11 is high. This is because defects such as stringing occur and a good print pattern cannot be obtained. On the other hand, when the holding time exceeds 10 seconds, the organic solvent contained in the conductive paste C is applied to the primer layer 2. It is because it is absorbed too much and the viscosity of the conductive paste C becomes too high and transfer to the transparent substrate F becomes difficult.

Next, the conductive paste C is applied to the surface of the plate cylinder 11 by the dispenser 13, and surplus portions other than the pattern grooves 12 are removed from the applied conductive paste C by the blade 14.
Next, the transparent base material F is rotated against the plate cylinder 11 while being pressed against the plate cylinder 11 from the backup rolls 15 and 16, whereby the conductive paste C on the plate cylinder 11 and the primer layer of the transparent substrate F are obtained. 2 and is held for a predetermined time as described above.
Next, the transparent base material F is pulled out by the backup roll 16, and the transparent base material F is separated from the plate cylinder 11, thereby transferring the conductive paste C on the plate cylinder 11 onto the primer layer 2 of the transparent base material F. .

Next, heat treatment is performed using a dryer or the like to form the first metal layer 3. This heat treatment is preferably performed at 180 ° C. or lower in consideration of heat resistance of the transparent substrate F and dry cracking of the transfer film of the conductive paste C.
By the above, the 1st metal layer 3 of a predetermined pattern can be formed on the primer layer 2 of the transparent base material F by the gravure printing method.

  Thus, by using the primer layer-forming paint and conductive paste having the above-described composition, it is excellent in transferability and transfer rate to the transparent substrate F, and without using a transfer sheet (blanket), the plate cylinder The “gravure direct printing method” in which the conductive paste C is directly transferred from 11 to the transparent base material F becomes possible.

Further, this gravure direct printing method eliminates the need for a blanket, and by using a cylindrical plate cylinder 11, an endless plate using a cylinder plate can be realized.
Further, by using the plate cylinder 11, the plate cylinder 11 can be manufactured by maskless direct drawing. Further, by adjusting the depth of the pattern groove 12 of the plate cylinder 11, it is possible to print a thicker film than in the case of gravure printing using a blanket. Therefore, the surface resistance is 50 Ω / □ or less depending on the thickness of the conductive paste, and the deposition of electrolytic plating can be facilitated.

Further, by pressing the transparent substrate F against the plate cylinder 11 for a predetermined time, the solvent in the conductive paste filled in the pattern groove 12 is absorbed into the primer layer 2 as the receiving layer, so that the conductive paste The viscosity rapidly increases, and the conductive paste filled in the pattern groove 12 can be transferred to the transparent substrate F side while maintaining the image shape of the plate as it is.
Further, the solvent absorbed in the primer layer 2 once dissolves the resin on the surface of the primer layer 2 and is compatible with the conductive paste at the interface, so that the transparent substrate F after drying and the first metal layer 3 Adhesion strength increases. As described above, a fine pattern having a line width L of about 5 μm to 20 μm can be printed at a high speed of about 10 m / min while maintaining the designed image shape.

"Formation of second metal layer"
Next, the transparent base material F on which the first metal layer 3 is formed is immersed in an electrolytic copper plating bath or an electrolytic nickel plating bath, and a metal is deposited on the first metal layer 3, whereby the second A metal layer 4 is formed.
Further, black plating is performed as necessary. The black plating preferably does not deteriorate the conductivity of the second metal layer 4, and examples thereof include black nickel plating, black chrome plating, and nickel-tin alloy plating.

This black plating can simultaneously blacken the three surfaces of the mesh film (second metal layer 4 and electromagnetic wave shielding film 5) and both side surfaces, and does not deteriorate the conductivity.
On the other hand, since the mesh portion on the back side of the first metal layer 3 also has a good black color due to the black pigment in the conductive paste, it is possible to blacken the four sides of the mesh film surface, both side surfaces, and the back surface. Yes, good contrast can be obtained even when mounted on a display.
As described above, a transparent base material with an electromagnetic wave shielding film having high conductivity and excellent transparency and excellent blackness of a mesh pattern can be manufactured by a short process and an inexpensive manufacturing process.

FIG. 4 is a schematic configuration diagram illustrating a modification of the manufacturing apparatus for the transparent base material with an electromagnetic wave shielding film used in the method for manufacturing the transparent base material with an electromagnetic wave shielding film of the present embodiment.
The manufacturing apparatus for the transparent base material with an electromagnetic wave shielding film shown in FIG. 4 differs from the manufacturing apparatus for the transparent base material with an electromagnetic wave shielding film shown in FIG. 2), the blade 21 is provided, and after the blade 14 removes the surplus portion other than the pattern groove 12 in the conductive paste C, the blade 21 further removes the surplus portion of the conductive paste C. It is.

Also in this manufacturing apparatus, there can exist the same effect as the manufacturing apparatus shown in FIG.
In addition, since the surplus portions other than the pattern grooves 12 are removed from the conductive paste C applied using the blades 14 and 21, the pattern accuracy of the conductive paste C transferred onto the primer layer 2 is further improved. be able to.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to a following example.

"Example 1"
"Preparation of primer layer coating and formation of primer layer"
240 g of alumina ultrafine particles (Al ₂ O ₃ -C, average particle size: 13 nm, oil absorption: 1.32 ml / g, specific surface area: 100 m ² / g, manufactured by Nippon Aerosil Co., Ltd.), 28 g of a phosphoric ester dispersant are added to toluene The mixture was added to 1332 g and dispersed using a sand mill to prepare an alumina dispersion.
Next, 240 g of ethyl cellulose was dissolved in 1808 g of toluene, and the above alumina dispersion, 552 g of cyclohexanone, and 1800 g of methyl ethyl ketone (MEK) were added to this solution and mixed with a homogenizer to prepare a primer layer forming coating material.
Next, this primer layer forming coating was applied by gravure printing on a PET film having a thickness of 125 μm, a width of 1500 mm, and a total length of 1200 m, and then dried to obtain a transparent film. The obtained primer layer had a thickness of 2 μm.

"Preparation of conductive paste and formation of first metal layer"
Silver powder (Ag-1S, average particle size: 0.9 μm, shape: granular, manufactured by Dowa Hitech) 67.0 parts by weight and terpineol 28.5 parts by weight, ethyl cellulose (EC (100 cP), manufactured by Nisshin Kasei Co., Ltd.) ) After compounding 4.5 parts by weight of the resin solution and pre-kneading, it is sufficiently pulverized and kneaded by a three-roll mill so that the maximum particle size by the particle gauge is 5 μm or less. Produced.

Next, using this conductive paste and the above transparent film, a mesh pattern was gravure-printed on the transparent film at a speed of 10 m / min with a gravure plate of L / S = 20/280 μm using the manufacturing apparatus shown in FIG. And dried at 120 ° C. for 3 minutes to obtain a printed mesh film.
The obtained mesh pattern was L / S = 16/284 μm, the film thickness was 2 μm, the shape was linear, and there was no problem in appearance. The surface resistance of the mesh pattern was 10Ω / □.

"Formation of second metal layer"
The printed mesh film is immersed in an electrolytic copper plating solution (Top Lucina SF, manufactured by Okuno Seiyaku Co., Ltd.) at 25 ° C., phosphorous copper is used for the anode, and the cathode is used as the PET film with the above mesh pattern. A DC current of / m ² was applied for 10 minutes to deposit copper on the mesh pattern to form an electrolytic copper plating film having a thickness of 2 μm.
Thereafter, nickel / tin alloy plating with a film thickness of 0.3 μm was applied to blacken the surface of the mesh pattern.
The obtained metal mesh film had L / S = 20/280 μm, a surface resistance of 0.1Ω / □, and a total light transmittance of 84%. Moreover, the size had a favorable external appearance over width 1500mm and full length 1000m.

"Comparative Example 1"
"Preparation of primer layer coating and formation of primer layer"
In the same manner as in Example 1, a primer layer was formed on a PET film to produce a transparent film.
"Preparation of conductive paste and formation of first metal layer"
A conductive paste was produced in the same manner as in Example 1.
Next, using this conductive paste and the above transparent film, a normal gravure printing with no adhesion time is performed on the transparent film at a speed of 10 m / min, and a mesh pattern with a gravure plate of L / S = 20/280 μm. Was gravure-printed and dried at 120 ° C. for 3 minutes to obtain a printed mesh film.
The obtained mesh pattern had a large amount of bleeding and chipping partially, resulting in appearance defects that lacked linearity. Further, this mesh pattern had L / S = 30/270 μm, a film thickness of 1.0 μm, and a surface resistance of 100Ω / □.

"Formation of second metal layer"
An attempt was made to form an electrolytic copper plating film on the above printed mesh film in the same manner as in Example 1, but the copper deposition was poor and electrolytic plating could not be performed.

"Comparative Example 2"
"Preparation of primer layer coating and formation of primer layer"
In the same manner as in Example 1, a primer layer was formed on a PET film to produce a transparent film.
"Preparation of conductive paste and formation of first metal layer"
A conductive paste was produced in the same manner as in Example 1.
Next, using this conductive paste and the above transparent film, L / S = 30/270 μm on the transparent film at several printing speeds by the screen printing method disclosed in JP-A-2003-145709. A mesh pattern was screen-printed using a screen plate of No. 1 and dried at 120 ° C. for 3 minutes to obtain a printed mesh film.
There was no defect in the appearance of the mesh pattern, and the limit printing speed at which a good shape of the printing mesh was obtained was 1 m / min, and the productivity was low.
The printed mesh obtained at a printing speed of 1 m / min had L / S = 25/275 μm, a film thickness of 5 μm, and a surface resistance value of 5Ω / □.

  The transparent substrate with an electromagnetic wave shielding film of the present invention is a method in which a primer layer on a transparent substrate is pressed against a conductive paste on a plate cylinder for gravure printing on one main surface of the transparent substrate having flexibility. A mesh pattern comprising a first metal layer having a mesh pattern formed by transferring a conductive paste onto a primer layer, and a second metal layer formed by electrolytic plating on the first metal layer A transparent base material with an electromagnetic wave shielding film having excellent transparency, a small haze value, a high precision and a thin film pattern could be easily realized by laminating an electromagnetic wave shielding layer having Therefore, it can be applied not only to various flat panel displays (FPD) such as plasma display panels (PDP) but also to other display devices and building materials. Value is quite large.

It is a top view which shows one Embodiment of the transparent base material with an electromagnetic wave shielding film of this invention. It is an expanded sectional view which follows the AA line of FIG. It is a schematic block diagram which shows an example of the manufacturing apparatus of the transparent base material with an electromagnetic wave shielding film used for the manufacturing method of the transparent base material with an electromagnetic wave shielding film of this invention. It is a schematic block diagram which shows the modification of the manufacturing apparatus of the transparent base material with an electromagnetic wave shielding film used for the manufacturing method of the transparent base material with an electromagnetic wave shielding film of this invention.

Explanation of symbols

1 Transparent substrate 2 Primer layer (underlayer)
3 First metal layer (lower metal layer)
4 Second metal layer (upper metal layer)
5 Electromagnetic wave shielding pattern 10 Transparent substrate with electromagnetic wave shielding film

Claims (4)

A transparent base material having flexibility, a primer layer formed on the transparent base material, a first metal layer formed on the primer layer and having a predetermined pattern, and on the first metal layer A transparent base material with an electromagnetic wave shielding film integrated with the formed second metal layer,
The first metal layer is formed by transferring the conductive paste onto the primer layer by pressing the primer layer on the transparent substrate against the conductive paste on the plate cylinder for gravure printing,
The transparent base material with an electromagnetic wave shielding film, wherein the second metal layer is formed by electrolytic plating. A transparent base material having flexibility, a primer layer formed on the transparent base material, a first metal layer formed on the primer layer and having a predetermined pattern, and on the first metal layer A method for producing a transparent base material with an electromagnetic wave shielding film in which the formed second metal layer is integrated,
On a plate cylinder for gravure printing, a conductive paste containing at least conductive particles, a binder resin and a solvent is applied in a predetermined pattern,
Next, the conductive paste on the plate cylinder and the primer layer formed on the transparent substrate are pressed and held for a predetermined time,
Next, the conductive paste on the plate cylinder is transferred onto the primer layer on the transparent substrate by separating the transparent substrate and the plate cylinder,
Next, the conductive paste pattern is heat-treated to form a first metal layer, and the second metal layer is formed by electroplating the first metal layer. A manufacturing method of a transparent substrate with an adhesive.   The method for producing a transparent base material with an electromagnetic wave shielding film according to claim 2, wherein the holding time is 0.5 seconds or more and 10 seconds or less. For the primer layer, a primer-forming paint containing oxide fine particles, a binder resin, and a solvent, and having an oil absorption amount of 0.5 ml / g or more and a specific surface area of 50 m ² / g or more is used. The method for producing a transparent substrate with an electromagnetic wave shielding film according to claim 2, wherein the transparent substrate is formed.

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