JP2012164885A - Electromagnetic wave shield material, manufacturing method thereof, and plasma display panel equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic wave shield materials which prevent firing of solvents and guarantees safe work environment in the manufacturing processes.SOLUTION: An electromagnetic wave shield material 1 is rolled up. The electromagnetic wave shield material 1 includes a long PET base layer 4. An ink receptive layer 6 is provided on the PET base layer 4 for preventing bleeding of a conductive paste ink. Multiple lattice shape electromagnetic wave shield mesh layers 7 are provided on the ink receptive layer 6 so as to be spaced away from each other in the longitudinal direction of the PET base layer 4. Belt like conductive layers 11, each of which connects the adjacent electromagnetic wave shield mesh layers 7, are provided on the ink receptive layer 6. A function layer 5 is provided on the ink receptive layer 6 so as to cover the electromagnetic wave shield mesh layers 7 and the belt like conductive layers 11.

Description

  The present invention generally relates to an integrated electromagnetic shielding material that can be wound into a roll, and more specifically, an improved electromagnetic shielding that can be continuously screen-printed while grounding. Regarding materials. The present invention also relates to a method for producing such an electromagnetic shielding material. The present invention further relates to a plasma display panel provided with such an electromagnetic wave shielding material.

  FIG. 4A is a conceptual diagram of a conventional plasma display panel. FIG. 4B is a cross-sectional view taken along line BB in FIG.

  With reference to these drawings, a filter 23 is disposed on the front side of the display unit 22 of the plasma display panel 21. The filter 23 includes a glass substrate layer 24, an antireflection film 25, a mesh film 26 and a protective film 27. The antireflection film 25 is formed by coating an antireflection film 5a on a PET film. The mesh film 26 is formed by forming a conductive mesh 6a on a PET film. The protective film 27 is formed of a PET film. The glass base material layer 24, the antireflection film 25, the mesh film 26, and the protective film 27 are bonded together with adhesive layers 8a, 8b, and 8c, respectively.

  Referring to FIG. 4C, the conductive mesh 6a is formed in a lattice shape by screen printing using, for example, a silver paste. A connection pad 6b connected to a conductive gasket 29 described later is also formed simultaneously with the conductive mesh 6a by screen printing so as to surround the lattice.

  As shown in FIG. 4B, the filter 23 is pressed and fixed to the front surface of the plasma display panel 21 so that the conductive gasket 29 and the connection pad 6b are in contact with each other.

  The harmful electromagnetic wave emitted from the plasma display panel 21 is captured by the conductive mesh 6a, passes through the connection pad 6b, the conductive gasket 29, and the casing, and is connected to the ground to escape.

  In the conventional method, as described above, since the number of adhesive / film layers is large, the number of parts is large, the work is complicated, and the cost is high. In addition, since the optical filter is formed of a glass substrate, it is easy to break, the roll-to-roll flow operation cannot be performed, and the work efficiency is lowered.

  Therefore, the applicants proposed an integrated electromagnetic shielding material that can realize roll-to-roll and can be wound into a roll (Patent Document 1).

  FIG. 5A is a conceptual diagram of a plasma display panel equipped with an electromagnetic wave shielding material including a transparent conductive sheet disclosed in Patent Document 1. FIG. 5B is a plan view of the electromagnetic wave shielding material. FIG. 5C is a cross-sectional view taken along the line CC in FIG.

  With reference to these drawings, the electromagnetic wave shielding material 1 is used by being mounted on the display unit 3 of the plasma display panel 2 and blocks electromagnetic waves emitted from the plasma television. The electromagnetic wave shielding material 1 includes a composite base material in which a PET base material layer 4 (100 μm) and a functional layer 5 are integrated.

  A transparent porous layer (1 μm) which is an ink receiving layer 6 for preventing bleeding (line thickening) of the conductive paste ink is formed on the other surface of the PET base material layer 4 (side to be attached to the plasma display panel PDP). Is provided. On the ink receiving layer 6, there is provided an electromagnetic wave shielding mesh layer 7 formed by screen-printing conductive paste ink and firing it.

  In this manner, functions such as antireflection, hard coat, antiglare, antistatic, and magnetic wave shielding can be created on a single base film (for example, PET film) by coating or printing. Therefore, basically, the front filter can be constituted by a single bonding, and a roll-to-roll operation can be performed.

Japanese Patent Application No. 2010-136340

  By the way, since the electromagnetic shielding material of patent document 1 is thin, in order to raise intensity | strength, as shown in FIG. 6, the case where it sticks to the glass substrate 8 with the adhesive agent 9 may be preferable. In that case, the order of laminating the electromagnetic wave shielding material 1 is, conversely, the ink receiving layer 6, the electromagnetic wave shielding mesh layer 7, and the functional layer 5 on the PET base material layer 4 as shown in FIG. preferable.

  Such an electromagnetic wave shielding material is manufactured through the process shown in FIG. That is, with reference to FIG. 7 (A), the PET base material layer 4 is prepared. With reference to FIG. 7 (B), the ink receiving layer 6 is formed on the PET base material layer 4, and FIG. With reference to C), the electromagnetic wave shielding mesh layer 7 is laminated thereon, and with reference to FIG. 7D, the functional layer 5 is formed thereon. The functional layer 5 is formed by dissolving a resin in, for example, a solvent of methyl ethyl ketone and applying and drying. A problem arises here, which will be described later.

  Next, the above problem will be described.

  FIG. 8 is a plan view of the laminate obtained in the step of FIG. An electromagnetic wave shielding mesh layer 7 is formed side by side in the longitudinal direction of the PET base material layer 4. This step is realized by screen printing shown in FIG. That is, in the screen printing, the long PET base material layer 4 on which the ink receiving layer 6 shown in FIG. 7B is formed is conveyed to a screen printer by a roll, and the first screen shown in FIG. 9 moves up and down. This is done by passing under 10. A pattern of the electromagnetic wave shielding mesh layer 7 is formed in the first screen 10. Conductive silver paste ink is supplied to the first screen 10 and the electromagnetic wave shielding mesh layer 7 is continuously printed. The problem is that the pattern of the electromagnetic wave shielding mesh layer 7 is not continuous at this time, so even if the earth is taken from a part of the electromagnetic wave shielding mesh layer 7, the entire roll cannot be grounded. The static electricity is charged on the PET base material layer 4. As a result, referring again to FIG. 7D, when the raw material resin solution of the functional layer 5 is applied onto the charged PET base material layer 4, there is a risk that methyl ethyl ketone (MEK), which is the solvent, will ignite. There was sex.

  This invention was made in order to solve the said subject, and it aims at providing the electromagnetic wave shielding material improved so that the ignition of a solvent may not be produced in the process of forming a functional layer.

  Another object of the present invention is to provide an electromagnetic shielding material manufacturing method improved so as not to cause solvent ignition.

  Still another object of the present invention is to provide a plasma display panel on which such an electromagnetic wave shielding material is mounted.

  The present invention is an electromagnetic wave shielding material wound up in a roll shape, and has a long PET base material layer and bleeding of conductive paste ink (line thickening) provided on the PET base material layer. A grid-like electromagnetic wave shielding mesh provided in a longitudinal direction on the PET base material layer and arranged in a row at intervals on the ink receiving layer A layer-like conductive layer provided on the ink-receiving layer and connecting the adjacent electromagnetic shielding mesh layers, and the ink-receiving layer so as to cover the electromagnetic shielding mesh layer and the belt-like conductive layer. And a functional layer provided on the surface.

  The functional layer is formed by curing a polymerizable binder coating solution, and includes a hard coat functional layer having a hard coat function, an antireflection functional layer having an antireflection function, and an antiglare functional layer having an antiglare function. An antistatic functional layer having an antistatic function, and the like. The functional layer is a single layer or a plurality of layers having a plurality of functions among the above functions.

  The polymerizable binder coating liquid contains an ultraviolet curable resin, a photopolymerizable initiator, and the like. A hard coat layer is obtained by applying a known polymerizable binder coating solution and curing by irradiation with ultraviolet rays or heating. This polymerizable binder coating solution may contain other components in addition to the above resin as long as the effects of the present invention are not impaired. Other components are not particularly limited, and for example, translucent organic fine particles may be added to the polymerizable binder coating liquid in order to develop an antiglare function in the hard coat layer. In order to develop an antistatic function in the hard coat layer, conductive fine particles such as ITO (indium-tin composite oxide) fine particles, ATO (antimony-tin composite oxide) fine particles, zinc antimonate fine particles, and polythiophenes Π-conjugated conductive polymers such as polypyrroles and polyanilines, and cationic, anionic, and nonionic surfactants may be added.

  Furthermore, in order to express the antireflection function, an antireflection layer can be provided on the hard coat layer.

  The antireflection layer is formed by applying and curing a high refractive index layer / low refractive index layer or a low refractive index layer on the coating surface of the functional layer.

  The high refractive index layer is formed by curing a high refractive index layer coating liquid containing an inorganic material, an ultraviolet curable resin, or the like.

  As the inorganic material, zinc oxide, titanium oxide, cerium oxide, tin oxide, aluminum oxide, zirconium oxide, or the like can be used.

  The refractive index of the high refractive index layer needs to be higher than that of the low refractive index layer formed immediately above the high refractive index layer, and the refractive index is preferably in the range of 1.55 to 1.90. Is within.

  The optical film thickness (nd) of the high refractive index layer is preferably 100 nm to 250 nm.

  The low refractive index layer is formed by curing a coating solution for forming a low refractive index layer containing silica fine particles, a binder component and the like.

  As the silica fine particles, silica sol, porous silica fine particles, hollow silica fine particles and the like can be used. As the binder component, a simple substance or a mixture of a fluorine-containing organic compound, a simple substance or a mixture of a fluorine-free organic compound, a polymer, or the like can be used.

  The refractive index of the low refractive index layer is preferably in the range of 1.20 to 1.45. The optical film thickness (nd) of the low refractive index layer is preferably 100 nm to 175 nm.

  A method according to another aspect of the present invention is a method for producing an electromagnetic wave shielding material wound up in a roll shape, the step of preparing a long PET base material layer, on the PET base material layer, A step of forming an ink receiving layer for preventing bleeding (line thickening) of the conductive paste ink; and a grid-like electromagnetic shielding mesh layer on the ink receiving layer, and a longitudinal direction of the PET base material layer A step of screen printing with a plurality of intervals, a step of screen printing a pattern of a strip-like conductive layer so as to connect the adjacent grid-like electromagnetic shielding mesh layer on the ink receiving layer, and And a step of forming a functional layer on the ink receiving layer so as to cover the electromagnetic shielding mesh layer and the belt-like conductive layer.

  Since screen printing is performed so that adjacent electromagnetic shielding mesh layers are connected by a band-shaped conductive layer, the grounding of the entire roll can be obtained by grounding from a part of the electromagnetic shielding mesh layer. Even when static electricity is generated in the PET base material layer during screen printing, the static electricity escapes to the adjacent electromagnetic shielding mesh layer through the belt-like conductive layer and is not charged.

  According to the present invention, even when static electricity is generated in the PET base material layer when screen printing the electromagnetic shielding mesh layer, the static electricity is removed from the adjacent electromagnetic shielding mesh by grounding from a part of the electromagnetic shielding mesh layer. Since it escapes to the layer and the PET base material layer is not charged, the solvent does not ignite in the step of forming the functional layer.

(A) It is a top view of the electromagnetic wave shielding material which concerns on Example 1, (B) It is sectional drawing which follows the BB line in FIG. 1 (A). The screen printing process of the electromagnetic wave shielding material which concerns on Example 1 is illustrated. (A) is a printing process of an electromagnetic wave shielding mesh layer, and (B) is a printing process of a strip-shaped conductive layer. 6 is a plan view of an electromagnetic shielding material according to various aspects according to Embodiment 2. FIG. (A) is an exploded perspective view of a functional film to be mounted on a conventional plasma display panel, (B) is a cross-sectional view taken along line BB in FIG. 4 (A), and (C) is a conductive mesh. It is a top view. (A) is a conceptual diagram of a plasma display panel equipped with an electromagnetic wave shielding material, (B) is a plan view of the electromagnetic wave shielding material, (C) is a cross-sectional view taken along line CC in FIG. 5 (B). It is. It is sectional drawing of the electromagnetic wave shielding material of the aspect used sticking to a glass substrate with an adhesive agent. It is sectional drawing of the process of the manufacturing method of the electromagnetic wave shielding material which concerns on FIG. FIG. 7C is a plan view of the step (C). It is a conceptual diagram of the screen printing process which implement | achieves the process of FIG.7 (C).

  The purpose of obtaining an improved electromagnetic shielding material manufacturing method so as not to cause solvent ignition is to connect the adjacent electromagnetic shielding mesh layers with a band-shaped conductive layer, thereby grounding from a part of the electromagnetic shielding mesh layer. Realized by taking. Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1A is a plan view of the electromagnetic shielding material according to the first embodiment. FIG. 1B is a cross-sectional view taken along line BB in FIG.

  With reference to these drawings, the electromagnetic shielding material 1 is wound up in a roll shape. The electromagnetic shielding material 1 includes a long PET base material layer 4. On the PET base material layer 4, an ink receiving layer 6 is provided for preventing bleeding (line thickening) of the conductive paste ink. A plurality of lattice-shaped electromagnetic wave shielding mesh layers 7 are provided side by side at intervals in the longitudinal direction of the PET base material layer 4 on the ink receiving layer 6. A band-like conductive layer 11 connecting adjacent electromagnetic shielding mesh layers 7 is provided on the ink receiving layer 6. A functional layer 5 is provided on the ink receiving layer 6 so as to cover the electromagnetic shielding mesh layer 7 and the strip-shaped conductive layer 11.

  2A and 2B are sectional views showing a screen printing process which is one process of manufacturing the electromagnetic shielding material 1 according to the embodiment. Two screen printers are used. Referring to FIG. 2A, the first screen 10 has a pattern of the electromagnetic wave shielding mesh layer 7 formed therein. 7A and 7B, the PET base material layer 4 having the ink receiving layer 6 is continuously conveyed to a screen printing machine (not shown) and under the first screen 10 that moves up and down. Pass through. A conductive silver paste is supplied to the first screen 10, and a grid-like electromagnetic shielding mesh layer 7 is stamped on the ink receiving layer 6 by its vertical movement.

  Subsequently, referring to FIG. 2B, a second screen printing machine having a second screen 12 that moves up and down, in which a pattern of a strip-like conductive layer 11 is formed, in front of the conveyance direction. The PET base material layer 4 having the ink receiving layer 6 is continuously conveyed to the second screen 12. The second screen 12 is supplied with a conductive copper paste or a conductive silver paste, and the vertical movement of the second screen 12 causes the strip-shaped conductive material to connect adjacent electromagnetic shielding mesh layers 7 on the ink receiving layer 6. Layer 11 is imprinted.

  Thereafter, an electromagnetic wave shielding material is completed through the same process as in FIG.

  According to the present invention, the belt-like conductive layer 11 is screen-printed so as to connect the adjacent electromagnetic shielding mesh layers 7, so that it can be continuously printed while grounding, and static electricity is applied to the PET base material layer 4. Not charged. As a result, the solvent does not ignite in the step of forming the functional layer 5 shown in FIG.

  In the electromagnetic wave shielding material shown in FIG. 1, the PET base material layer 4 is preferably polyethylene phthalate (PET) having a thickness of 75 to 100 μm. The ink receiving layer 6 is formed of a transparent porous material that is an aggregate of fine particles mainly composed of silica, titania, alumina, or the like.

  The functional layer 5 includes a hard coat layer formed by curing a polymerizable binder coating liquid containing ATO (antimony-tin composite oxide) fine particles, and an antireflection layer provided thereon. The antireflection layer comprises an optical film thickness (nd): 150 nm, a refractive index (n): 1.60, a high refractive index layer, and an optical film thickness (nd) provided on the high refractive index layer: 140 nm, Refractive index (n): It consists of a low refractive index layer of 1.35.

  Examples of the coating method of the functional layer 5 include a method of applying ultraviolet rays after coating and drying on a base film by a roll coating method, a spin coating method, a coil bar method, a dip coating method, a die coating method or the like. A method capable of continuous coating such as a roll coating method is preferred from the viewpoint of productivity and production cost.

  In the above embodiment, the case where one band-like conductive layer 11 linearly connects the adjacent electromagnetic shielding mesh layers 7 is illustrated, but the present invention is not limited to this, and FIG. As shown, the two strip-like conductive layers 11 may be connected. The number is not limited.

  Further, as shown in FIG. 3B, the conductive layer 11 may be connected to the adjacent electromagnetic shielding mesh layer 7 in a U shape. Even such a conductive layer can be continuously printed while grounding, and as a result, the static electricity is not charged in the PET base material layer.

  Further, as shown in FIG. 3C, adjacent electromagnetic shielding mesh layers 7 may be connected by two U-shaped conductive layers 11.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the method for manufacturing an electromagnetic wave shielding material according to the present invention, ignition does not occur in the manufacturing process, and the safety of the working environment is ensured.

DESCRIPTION OF SYMBOLS 1 Electromagnetic wave shielding material 2 Plasma display panel 3 Display part 4 PET base material layer 5 Functional layer 6 Ink receiving layer 7 Electromagnetic wave shielding mesh layer 8 Glass substrate 9 Adhesive 10 First screen 11 Band-shaped conductive layer 12 Second screen

Claims (7)

An electromagnetic shielding material wound in a roll shape,
A long PET substrate layer;
An ink receiving layer provided on the PET substrate layer for preventing bleeding of the conductive paste ink;
In the longitudinal direction of the PET base material layer, a plurality of lattice-shaped electromagnetic wave shielding mesh layers provided side by side on the ink receiving layer at intervals, and
An electromagnetic wave shielding material provided on the ink receiving layer and having a band-like conductive layer connecting the adjacent electromagnetic wave shielding mesh layers.   The electromagnetic wave shielding material according to claim 1, wherein a functional layer is provided on the ink receiving layer so as to cover the electromagnetic wave shielding mesh layer and the belt-like conductive layer. The electromagnetic wave shielding material according to claim 2, wherein the functional layer is at least one functional layer among a hard coat functional layer, an antireflection functional layer, an antiglare functional layer, and an antistatic functional layer.   The electromagnetic wave shielding material according to any one of claims 1 to 3, wherein the electromagnetic wave shielding mesh layer is formed by printing a conductive silver paste by a screen printing method.   The electromagnetic wave shielding material according to any one of claims 1 to 4, wherein the conductive layer is formed by printing a conductive copper paste by a screen printing method.   The plasma display panel formed by mounting | wearing with the electromagnetic wave shielding member obtained by cutting the electromagnetic wave shielding material of any one of Claims 1-5. A method for producing an electromagnetic shielding material wound in a roll,
Preparing a long PET substrate layer;
Forming an ink receiving layer for preventing bleeding of the conductive paste ink on the PET substrate layer;
On the ink-receiving layer, a grid-shaped electromagnetic wave shielding mesh layer is screen-printed with a plurality of intervals in the longitudinal direction of the PET base material layer; and
On the ink receiving layer, a step of screen printing a pattern of a strip-like conductive layer so as to connect the adjacent grid-like electromagnetic shielding mesh layers;
Forming a functional layer on the ink receiving layer so as to cover the electromagnetic shielding mesh layer and the belt-like conductive layer.

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