JP2010080654A - Method of manufacturing composite filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a composite filter that reduces the increase of haze by preventing the mixing of air bubbles into an adhesive layer without increasing a burden of equipment. <P>SOLUTION: The method of manufacturing a composite filter has (A) a step of preparing a continuous belt-like electromagnetic wave shield sheet which has at least a conductive mesh layer in one surface of a first transparent resin base sheet; (B) a step of preparing a continuous belt-like optical filter with an adhesive layer in one surface of a second transparent resin base sheet to which an optical function is imparted; (C) a step of heating at least the adhesive layer of the continuous belt-like optical filter; (D) a step of obtaining a continuous belt-like composite sheet by cooling at least the adhesive layer of the continuous belt-like optical filter and bonding the surface of the adhesive layer side of the continuous belt-like optical filter to the surface of the conductive mesh layer side of the continuous belt-like electromagnetic wave shield sheet; and (E) a step of dividing the continuous belt-like composite sheet. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a composite filter including an electromagnetic wave shielding sheet that shields (shields) electromagnetic waves generated from a display (image display device) such as a PDP (plasma display panel) and an optical filter.

  In recent years, with the advancement of functions and increasing use of electrical and electronic equipment, electromagnetic noise interference (EMI) has increased, and electromagnetic waves are also generated in displays such as cathode ray tubes (referred to as CRT) and plasma display panels (referred to as PDP). appear. In order to shield this electromagnetic wave, an electromagnetic wave shielding sheet disposed on the front surface of the display is known. In the electromagnetic wave shielding sheet used for such applications, light transmittance is also required in addition to the electromagnetic wave shielding performance. Therefore, an electromagnetic wave shielding sheet provided with light transmittance by forming a conductive mesh layer made of a metal such as copper on the transparent substrate using a transparent substrate such as a resin film or a glass plate as the substrate. It has been known.

  In addition, near infrared rays having a wavelength of 800 to 1,100 nm generated from the front of the display also cause other devices such as VTRs to malfunction, and need to be shielded. Further, there is a case where a function for shielding unnecessary light having a specific wavelength generated from the image display device or providing various functions necessary for the image display device is required.

In order to realize the above function, the electromagnetic wave shielding sheet and a plurality of optical filters such as a near-infrared absorption filter and an antireflection filter are laminated to shield unnecessary electromagnetic waves generated from the image display device and light of a specific wavelength. However, it has been studied to use a plate-like composite filter capable of providing various functions required for the image display device as a front plate of the plasma display panel. For example, there is a composite filter having a configuration in which an optical filter (functional film) is bonded to the surface of the electromagnetic shielding sheet on the conductive mesh layer side through an adhesive layer (adhesive layer) (Patent Document 1).
However, in the step of laminating the electromagnetic wave shielding sheet and the optical filter, since the opening of the electromagnetic wave shielding sheet is recessed, when the optical filter is laminated directly using an adhesive (adhesive), the inside of the mesh opening is filled. There was a problem that bubbles were mixed in the pressure-sensitive adhesive, image light was scattered by the bubbles, and haze (cloudiness value) was increased.
On the other hand, the problem of air bubbles in the resulting composite filter can be solved by heating and laminating under a pressurized atmosphere using an autoclave, etc., but in that case, the number of processes increases and the equipment burden increases. There is a problem of doing.

JP 2005-277438 A

  The present invention has been made in view of the above-mentioned problems, and is a composite that can prevent bubbles from entering into the pressure-sensitive adhesive layer (adhesive layer) and suppress an increase in haze without increasing the equipment burden. It aims at providing the manufacturing method of a filter.

As a result of intensive studies, the present inventors turned the adhesive surface of the optical filter to the surface on the side of the conductive mesh layer of the electromagnetic wave shielding sheet, and bonded the adhesive layer through the adhesive layer. The inventors have found that the above problem can be solved by expelling the contained gas, and have completed the present invention.
That is, the method for manufacturing a composite filter according to the present invention includes:
(A) preparing a continuous band-shaped electromagnetic shielding sheet having at least a conductive mesh layer on one surface of the first transparent resin substrate sheet;
(B) A step of preparing a continuous band-shaped optical filter having an adhesive layer on one surface of the second transparent resin base sheet provided with an optical function;
(C) heating at least the pressure-sensitive adhesive layer of the continuous belt-shaped optical filter;
(D) While cooling at least the pressure-sensitive adhesive layer of the continuous band-shaped optical filter, the surface of the continuous band-shaped optical filter on the pressure-sensitive adhesive layer side is the surface on the conductive mesh layer side of the continuous band-shaped electromagnetic wave shielding sheet. Pasting together to obtain a continuous strip-shaped composite sheet,
(E) A step of forming the continuous strip-shaped composite sheet into sheets.

  According to the method for manufacturing a composite filter according to the present invention, the adhesive filter surface is attached to the surface of the electromagnetic wave shielding sheet on the conductive mesh layer side, and the adhesion surface of the optical filter is bonded through the adhesive layer. By heating the adhesive layer in an appropriate temperature range, the gas contained in the adhesive layer can be expelled and the viscosity of the adhesive layer can be lowered to increase the adhesiveness. Next, by cooling the pressure-sensitive adhesive layer warmed to a high temperature, the pressure-sensitive adhesive layer is maintained so that no gas is generated from the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is bonded from the edge of the laminate. It can control so that an agent may not leak. Accordingly, after the pressure-sensitive adhesive layer is heated to a high temperature and then cooled to an appropriate temperature, the electromagnetic wave shielding sheet is bonded to the surface on the conductive mesh layer side so that the surface to be attached of the optical filter faces, thereby While improving the adhesiveness of a shielding sheet and this optical filter, a bubble is not mixed in this adhesive layer, but the raise of a haze can be suppressed. In addition, since it is not necessary to place in a pressurized atmosphere using an autoclave after lamination, which has been conventionally used to prevent air bubbles from being mixed into the pressure-sensitive adhesive layer, it is possible to reduce the equipment burden.

In the method for producing a composite filter according to the present invention, the electromagnetic wave shielding sheet has a primer layer between the first transparent resin base sheet and the conductive mesh layer, The thickness of the portion where the conductive mesh layer is formed is thicker than the thickness of the portion where the conductive mesh layer is not formed, and the conductive mesh layer is the first transparent resin. It is preferable that the cross-sectional area cut | disconnected by the virtual surface parallel to the base material sheet surface is the decreasing function S (x) of the distance x from this 1st transparent resin base material sheet.
In the conductive mesh layer, the cross-sectional area cut by a virtual plane parallel to the surface of the first transparent resin base sheet is a decreasing function S (x) of the distance x from the transparent resin base sheet. The air bubbles between the conductive mesh layer and the pressure-sensitive adhesive layer are easily removed when laminating the surface of the optical filter on the pressure-sensitive adhesive layer side from the conductive mesh layer. It is possible to make it difficult for bubbles to remain.

In the method for producing a composite filter according to the present invention, the interface between the primer layer and the conductive mesh layer is interleaved and / or in the vicinity of the interface between the primer layer and the conductive mesh layer. A region where the primer component contained in the primer layer and the conductive composition constituting the conductive mesh layer are mixed, and / or in the conductive composition constituting the conductive mesh layer The primer component contained in the primer layer is preferably present.
Since the interface between the primer layer and the conductive mesh layer on the first transparent resin base sheet of the electromagnetic wave shielding sheet is not a simple interface structure, the adhesion between both layers is improved. Further, when the electromagnetic wave shielding sheet is produced, since the transfer (transfer) of the conductive composition filled in the plate surface to the transparent resin base sheet is reliably performed under a high transfer rate, the conductivity It can be set as the electromagnetic wave shielding sheet which does not produce malfunctions, such as a disconnection based on the transfer defect of a composition, a shape defect, and low adhesiveness.

  The method for producing a composite filter according to the present invention specifies the adhesive layer before attaching the optical filter to the surface on the conductive mesh layer side of the electromagnetic wave shielding sheet and bonding the adhesive layer through the adhesive layer. By heating in this temperature range, the gas contained in the pressure-sensitive adhesive layer can be expelled and the viscosity of the pressure-sensitive adhesive layer can be lowered to increase the pressure-sensitive adhesiveness. Next, by cooling the pressure-sensitive adhesive layer heated to a high temperature in a specific temperature range, it is possible to control the pressure-sensitive adhesive layer so that no gas is generated while maintaining the pressure-sensitive adhesive layer. it can. Therefore, by heating the pressure-sensitive adhesive layer to a high temperature and then cooling it to an appropriate temperature, the surface of the electromagnetic wave shielding sheet on the side of the conductive mesh layer is bonded to the surface on the base side of the optical filter, While improving the adhesiveness of this electromagnetic wave shielding sheet and this optical filter, a bubble is not mixed in this adhesive layer, but the raise of a haze can be suppressed. Moreover, since the process of heating and laminating in a vacuum atmosphere using an autoclave or the like, which has been conventionally used for preventing air bubbles from being mixed into the pressure-sensitive adhesive layer, is unnecessary, the equipment burden can be reduced.

  The method for producing a composite filter according to the present invention includes (A) a step of preparing a continuous band-shaped electromagnetic wave shielding sheet having at least a conductive mesh layer on one surface of a first transparent resin base sheet, and (B). A step of preparing a continuous band-shaped optical filter having an adhesive layer on one surface of the second transparent resin substrate sheet imparted with an optical function; and (C) at least an adhesive layer of the continuous band-shaped optical filter. A step of heating; (D) cooling at least the pressure-sensitive adhesive layer of the continuous band-shaped optical filter, and the surface of the continuous band-shaped optical filter on the pressure-sensitive adhesive layer side is electrically conductive mesh of the continuous band-shaped electromagnetic wave shielding sheet It is characterized by having a step of obtaining a continuous strip-shaped composite sheet by laminating toward the layer-side surface, and a step (E) of making the continuous strip-shaped composite sheet into a single sheet.

Hereinafter, the manufacturing method of the composite filter of this invention is demonstrated.
(A) Step of preparing a continuous belt-shaped electromagnetic shielding sheet Step (A) is a step of preparing a continuous strip of electromagnetic shielding sheet having at least a conductive mesh layer on one surface of the first transparent resin substrate sheet. It is.
In this step, first, a first transparent resin base sheet (hereinafter also simply referred to as “transparent resin base sheet”) is prepared, and a conductive mesh layer is formed on one surface of the transparent resin base sheet. Form. The method for forming the conductive mesh layer is not particularly limited, and examples thereof include the following four methods.
(1) Intaglio printing the conductive ink composition on a transfer body with a mesh pattern, transferring the mesh pattern on the transfer body onto a transparent resin base sheet, and applying a metal layer to the mesh pattern on the transparent resin base sheet A method of electroplating (for example, JP 2000-13088 A, JP 2001-102792 A, PCT / JP2008 / 60427).
(2) A method in which a conductive ink or a photosensitive coating solution containing a chemical plating catalyst is applied to the entire surface of a transparent resin base sheet, the coating layer is meshed by a photolithography method, and then metal plating is performed on the mesh. (For example, Sumitomo Osaka Cement Co., Ltd., New Materials Division, New Materials Research Institute, New Materials Research Group, “Photoresolvable Chemical Plating Catalyst”, [online], date not listed, Sumitomo Osaka Cement Co., Ltd., [Search on January 7, 2003], Internet <URL: http://www.socnb.com/product/hproduct/display.html>).
(3) A method in which a transparent resin base sheet and a metal foil are laminated using an adhesive as necessary, and then the metal foil is meshed by a photolithography method (for example, JP-A-11-145678).
(4) A transparent resin substrate sheet in which a metal thin film is formed on one surface of the transparent resin substrate sheet by sputtering or the like to form a conductive treatment layer, and a metal layer is formed thereon as a metal plating layer by electrolytic plating. In which the metal plating layer and the conductive treatment layer of the transparent resin base sheet subjected to metal plating are formed into a mesh by a photolithography method (for example, Japanese Patent No. 3502979, Japanese Patent Application Laid-Open No. 2004-241761).

In the present invention, a primer layer may be formed before forming the conductive mesh layer on one surface of the transparent resin substrate sheet. As a method for forming the primer layer on one surface of the transparent resin substrate sheet, for example, when using a wet film forming method, the primer layer resin composition is applied to one surface of the continuous transparent resin substrate sheet. It can be formed by coating (for example, 10 g / m ² ) by various coating methods such as a gravure reverse method.

Hereinafter, the electromagnetic wave shielding sheet used in the present invention will be described in order from the first transparent resin base sheet.
(First transparent resin base sheet)
The first transparent resin base sheet is a layer for reinforcing a mesh layer having a low mechanical strength. Therefore, as long as it has light transmission as well as mechanical strength, it may be selected and used depending on the application, taking into account heat resistance and the like as appropriate. A specific example of the transparent resin base sheet is a sheet (or a film; the same applies hereinafter) made of an organic material such as a resin.

  Examples of the transparent resin used as the sheet made of the organic material include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, terephthalic acid-isophthalic acid-ethylene glycol copolymer, and terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer. Polyester resins such as nylon 6, polyamide resins such as nylon 6, polyolefin resins such as polypropylene, polymethylpentene, and polycycloolefin, acrylic resins such as polymethyl methacrylate, styrene such as polystyrene and styrene-acrylonitrile copolymer Examples of the resin include cellulose resins such as triacetyl cellulose, imide resins, and polycarbonate resins.

These resins are used as a resin material alone or as a plurality of types of mixed resins (including polymer alloys), and as a layer, a single layer or a laminate of two or more layers is used. In the case of a resin sheet, a uniaxially stretched or biaxially stretched sheet is more preferable in terms of mechanical strength.
In addition, ultraviolet resins, fillers, plasticizers, antistatic agents, infrared absorbers, dyes (colored dyes, colored pigments), extender pigments, light diffusing agents, and the like are added to these resins as necessary. An agent may be added.

The thickness of the transparent resin base sheet is not particularly limited as long as it depends on the application, and when it is made of a transparent resin, it is usually about 12 to 500 μm, preferably 50 to 125 μm. If the thickness is less than the above, the mechanical strength is insufficient and warping, slackening, breakage or the like occurs, and if the thickness exceeds the above, the cost is increased due to excessive performance and it is difficult to reduce the thickness.
In addition, the transparent resin base material sheet is handled in the form of a continuous belt-like sheet in the stage before the step of making the composite sheet into a single sheet in that the electromagnetic wave shielding sheet can be continuously produced and productivity can be improved. Is preferred.

In this respect, as the transparent resin base sheet, in particular, polyester resin sheets such as polyethylene terephthalate and polyethylene naphthalate are preferable in terms of transparency, heat resistance, cost, and more preferably biaxial stretching. Polyethylene terephthalate sheet is most suitable. In addition, although the transparency of a transparent resin base material is so good that it is good, Preferably the light transmittance which becomes 80% or more by visible light transmittance | permeability is good.
In addition, a transparent resin base sheet such as a resin sheet is appropriately subjected to corona discharge treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, preheat treatment, dust removal treatment, vapor deposition treatment, alkali treatment, You may perform well-known easy-adhesion processing, such as.

(Primer layer)
In the present invention, it is particularly used when a conductive mesh layer made of a conductive composition (ink or paste) is formed using a specific intaglio printing method described later. The primer layer has a unique and novel function unique to the present invention as described below, in addition to the function of a conventionally known and commonly used simple adhesive primer for improving the adhesion between the transparent resin base sheet and the conductive mesh layer. And has a novel layer structure and form. The primer layer is preferably a material having good adhesion to both the transparent resin base sheet and the conductive mesh layer, and is preferably transparent for installation on the front surface of the display device. For example, a layer formed by coating a thermoplastic resin or an ionizing radiation curable resin is preferable. Various additives and modified resins may be used to improve adhesion, durability, and impart various physical properties.

  Examples of the thermoplastic resin include acrylic resins such as polymethyl methacrylate (PMMA), vinyl chloride-vinyl acetate copolymers, polyester resins, and polyolefin resins.

  As the ionizing radiation curable resin, a monomer (monomer) that is polymerized and cured by a reaction such as crosslinking with ionizing radiation, or a prepolymer or an oligomer is used. Examples of the monomer include a radical polymerizable monomer and a cationic polymerizable monomer. Examples of the radical polymerizable monomer include various (meth) acrylates such as 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. Examples of the cationic polymerizable monomer include alicyclic epoxides such as 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate, glycidyl ethers such as bisphenol A diglycidyl ether, 4-hydroxybutyl, and the like. Examples include vinyl ethers such as vinyl ether and oxetanes such as 3-ethyl-3-hydroxymethyloxetane. In addition, as the prepolymer (or oligomer), for example, a radical polymerizable prepolymer, specifically, urethane (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, triazine (meth) acrylate, and the like. Examples include various (meth) acrylate prepolymers and unsaturated polyester prepolymers. In addition, cationic polymerizable prepolymers such as novolac epoxy resin prepolymers, aromatic vinyl ether resin prepolymers, or polythiol prepolymers such as trimethylolpropane trithioglycolate prepolymer, pentaerythritol tetrathioglycol A rate prepolymer etc. are mentioned. Here, (meth) acrylate means acrylate and / or methacrylate.

  These monomers or prepolymers may be used alone or in combination of two or more types of monomers, two or more types of prepolymers, or one type of monomer, depending on the required performance, coating suitability, etc. A mixture of the above and one or more prepolymers can be used.

  When ultraviolet rays or visible rays are used as the ionizing radiation, a photopolymerization initiator is added. As the photopolymerization initiator, in the case of a radical polymerizable monomer or prepolymer, a compound such as benzophenone, thioxanthone, or benzoin is used, and in the case of a cationic polymerization monomer or prepolymer, a metallocene is used. , Aromatic sulfonium-based and aromatic iodonium-based compounds are used. These photopolymerization initiators are added in an amount of about 0.1 to 5 parts by weight with respect to 100 parts by weight of the composition comprising the monomer and / or prepolymer.

  The ionizing radiation is typically ultraviolet rays or electron beams, but in addition, electromagnetic waves such as visible rays, X rays and γ rays, or charged particle rays such as α rays and various ion rays are used. You can also.

  Moreover, an additive is suitably added as needed. Examples of the additive include a heat stabilizer, a radical scavenger, a plasticizer, a surfactant, an antistatic agent, an antioxidant, an ultraviolet absorber, an infrared absorber, a dye (colored dye, colored pigment), and an extender pigment. And a light diffusing agent.

  The primer layer used in the present invention can maintain two states, a fluid state and a cured state. The primer layer is provided on the transparent resin substrate sheet in a state where the fluidity can be maintained after coating, and after that, when the conductive composition layer is transferred and formed on the primer layer, the primer layer is formed in a short time. It is necessary to be able to change from a fluid state to a cured state. Specifically, the primer layer in a fluid state flows into a recess at the upper part of the conductive composition layer in the intaglio plate surface, and the inside of the recess is filled, and there is a gap between the primer layer and the conductive composition layer. There is no state. In this state, by applying pressure to the plate surface, the plate surface and the primer layer are pressure-bonded, and then the primer layer is cured. As a result, it is possible to eliminate the occurrence of a gap between the primer layer and the conductive composition layer, which may have occurred in the past, and the problem of poor transfer and poor adhesion due to the existence of the gap does not occur.

As used herein, “fluidity” or “fluid state” refers to a property or state that flows (deforms) by pressure when the primer layer is pressure-bonded to a printing plate filled with a conductive composition. It is not necessary to have a low viscosity. Further, it is not always necessary to have Newtonian viscosity, and it may have non-Newtonian viscosity such as thixotropic property or dilatancy property.
The viscosity of the primer layer in a fluid state is usually in the range of 1 mPa · s to 100,000 mPa · s, and preferably in the range of 50 mPa · s to 2000 mPa · s.

  When the ionizing radiation curable resin is used as the primer layer resin composition, the primer layer can be obtained by simply applying an ionizing radiation curable ink on the transparent resin base sheet. The ionizing radiation curable ink is generally composed of the above-mentioned monomer or oligomer having ionizing radiation curability, and further contains a photopolymerization initiator (in the case of ultraviolet curing or photocuring), various additives, and the like as necessary. It exhibits fluidity until cured with ionizing radiation. The ink may contain a solvent. In this case, since a drying step is necessary after coating, the ink is preferably of a type that does not contain a solvent (so-called non-solvent type).

  Moreover, when a thermoplastic resin composition is used as the resin composition for the primer layer, the thermoplastic resin composition is applied on the transparent resin substrate sheet and becomes a fluid state (for example, 50 ° C to 200 ° C). To a certain extent). If the primer layer in such a fluid state is pressure-bonded to the intaglio plate surface filled with the conductive composition and then cured by cooling to transfer the conductive composition, the conductive composition layer and the primer Transfer can be performed without any gap between the layers. Here, as a method of applying the thermoplastic resin composition on the transparent resin base sheet, there are a method of applying a solution of the thermoplastic resin composition and then drying, and a method of applying a resin in a hot melt state. The thermoplastic resin composition coated on the transparent resin base sheet may be heated before contacting the plate surface filled with the conductive composition, and a heating roll or the like may be used for pressure bonding to the plate surface. However, in any case, when the conductive composition layer is transferred to the primer layer, the primer layer needs to be cooled to such an extent that the fluidity of the primer layer is lost.

  Although the thickness of a primer layer is not specifically limited, Usually, it forms so that it may become about 1 micrometer-100 micrometers by the thickness after hardening. In addition, as shown in FIG. 1, the thickness (TB) of the primer layer 2 in the portion where the conductive mesh layer 3 is not formed (mesh opening) is normally set to be equal to that of the conductive mesh layer 3 and the primer layer 2. 1 (total thickness, altitude difference between the top of the conductive mesh layer 3 and the surface of the transparent resin base sheet 1 in FIG. 1) is about 1 to 50%. The primer layer after the conductive composition layer is transferred onto the primer layer 2 and the conductive composition layer is further cured to produce an electromagnetic wave shielding sheet is formed as shown in FIG. The thickness TA of the portion A where 3 is formed is thicker than the thickness TB of the portion B where the conductive mesh layer 3 is not formed. In the primer layer 2, the side edges 5, 5 of the thick part A are in a form in which the conductive mesh layer 3 wraps around the thin part B.

In the form shown in FIG. 1, the primer layer 2 in a fluidized state before curing and the intaglio surface for shaping with a predetermined pattern filled with the conductive composition 15 constituting the conductive mesh layer 3 are pressure-bonded, After adhering the primer layer 2 and the conductive composition 15 without gaps, the primer layer 2 is cured, or the primer layer 2 and the conductive composition 15 are simultaneously cured, and then the transparent from the intaglio This is caused by releasing the resin base sheet and the cured primer layer and transferring (transferring) the conductive composition in the plate recess onto the cured primer layer. Specifically, on the plate surface of the intaglio plate in which the conductive composition 15 is filled in the recess, the excess conductive composition other than the recess is scraped off by the doctor blade. At that time, the depression 6 as shown in the enlarged view of FIG. 8 is likely to be formed on the upper portion of the conductive composition 15 in the depression, and the primer layer 2 in a fluid state flows into the plate surface having the depression 6. The inside of the dent 6 is filled, and the primer layer 2 is filled between the transparent resin base sheet 1 and the conductive composition 15 without any gap. When the primer layer 2 is in an uncured state, pressure is applied to the plate surface filled with the primer layer 2 so that the plate surface and the primer layer 2 are pressure-bonded, resulting in the form shown in FIG. .
The primer layer 2 is a transparent resin group including not only the portion A where the conductive mesh layer 3 is formed, but also the portion B where the conductive mesh layer 3 is not formed. It is preferable to form over the entire surface of the material sheet 1 (however, the primer layer 2 may be indispensable on a region where the pattern of the conductive mesh layer 3 is not required). By forming the primer layer 2 on the entire surface of the transparent resin base sheet 1 on which the conductive mesh layer 3 is not formed, the primer layer 2 exists only under the conductive mesh layer 3 and does not exist in the opening. Compared to the case, there is an effect that peeling of the conductive mesh layer 3 from the transparent resin base sheet 1 hardly occurs.

(Conductive mesh layer)
The conductive mesh layer 3 is a layer that can have an electromagnetic wave shielding function by having conductivity, and is itself made of an opaque material, but by processing into a mesh-like shape having a large number of openings, It is a layer that achieves both electromagnetic shielding performance and light transmittance.

  The thickness of the conductive mesh layer 3 is about 1 to 50 μm, preferably 2 to 15 μm. If the thickness is too thin, it will be difficult to obtain sufficient electromagnetic shielding performance due to an increase in electrical resistance, and if the thickness is too thick, it will be difficult to obtain a high-definition mesh shape, which will reduce the uniformity of the mesh shape. .

[Mesh shape]
The shape of the conductive mesh layer 3 as a mesh (mesh or lattice) is not particularly limited, but a square is typical as the shape of the opening of the mesh. The plan view shape of the opening is, for example, a triangle such as a regular triangle, a square such as a square, a rectangle, a rhombus, or a trapezoid, a polygon such as a hexagon, a circle, an ellipse, or the like. The mesh has a plurality of openings having these shapes, and generally, the openings are line-like line portions having a uniform width, and the openings and the line portions have the same shape and the same size over the entire surface. As an example of a specific size, the width of the line part between the openings is preferably 5 to 100 μm in terms of the aperture ratio and the invisibility of the mesh. The size of the opening is [line interval or line pitch] − [line width]. In terms of this [line interval or line pitch], the opening size is 100 μm to 500 μm, and the opening ratio (the total area of the openings / mesh portion) Is preferably 60 to 97% from the viewpoint of compatibility between light transmittance and electromagnetic wave shielding properties.
Note that the bias angle (the angle formed between the mesh line portion and the outer periphery of the electromagnetic wave shielding sheet) may be appropriately set to an angle at which moire is difficult to occur in consideration of the pixel pitch of the display and the light emission characteristics.

  The conductive mesh layer 3 may be a mesh region over the entire surface of the electromagnetic wave shielding sheet. However, a portion that requires light transmission is formed into a mesh shape, and other portions (for example, all four sides are surrounded in a frame shape). ) It may be non-mesh. The non-mesh region is a portion other than the mesh region and is a region where light transmittance is not necessary as a surface, and is normally used as a grounding region. Although the specific size of the non-mesh area depends on how it is used, when the frame is in the shape of a ground or outer frame, the width of the frame is about 15 to 100 mm, especially 30 to 40 mm. It is common.

The conductive mesh layer 3 is not particularly limited as long as it is a substance having sufficient conductivity to exhibit electromagnetic wave shielding performance, and examples thereof include a metal layer and a conductive composition.
The metal layer can be formed by vapor deposition, plating, metal foil lamination, or the like. Examples of the metal material of the metal layer or metal foil include gold, silver, platinum, copper, iron, aluminum, nickel, and chromium. The metal of the metal layer may be an alloy, and the metal layer may be a single layer or multiple layers. For example, in the case of iron, low carbon steel such as low carbon rimmed steel and low carbon aluminum killed steel, Ni-Fe alloy, Invar alloy, and the like are preferable. On the other hand, when the metal is copper, the metal material is copper or a copper alloy, and there are rolled copper foil and electrolytic copper foil as the copper foil. From the viewpoint of thinness and uniformity, the electrolytic copper foil is preferable. . As aluminum, in order to enhance the linearity of the contour line of the edge of the line portion during etching (corrosion) processing, an aluminum oxide film having a thickness of 3 to 13 mm is formed on the etching processing side. It is preferable.
The conductive composition is not particularly limited as long as it has fluidity at the time of filling in the recesses of the intaglio, and exhibits desired conductivity at a time after being formed into a desired pattern and cured. Various materials and forms can be used. A typical example is an ink or paste-like material having fluidity containing a conductive powder and a resin, and further containing a solvent or a dispersant for dissolving or dispersing the resin as necessary. The conductive mesh layer 3 made of the conductive composition is a coating film made of a solid after the conductive composition is dried or cured.
Hereinafter, the conductive mesh layer 3 made of the conductive composition will be described in more detail.

  For example, as described later, the viscosity of the conductive composition is such that the primer component in the primer layer 2 penetrates into the conductive composition to increase the viscosity, or the primer layer 2 and the conductive composition are simultaneously cured. However, it is generally not possible to say the magnitude of the preferred viscosity in relation to the production process, but the usable range is usually in the range of several hundred mPa · s to several million mPa · s, Preferably, it is in the range of several thousand mPa · s to tens of thousands mPa · s.

  As the binder resin constituting the conductive composition, any of thermosetting resins, ionizing radiation curable resins, and thermoplastic resins can be used. Examples of the thermosetting resin include resins such as melamine resin, polyester-melamine resin, epoxy-melamine resin, polyimide resin, thermosetting acrylic resin, thermosetting polyurethane resin, and thermosetting polyester resin. Examples of the ionizing radiation curable resin include those described above as materials for the primer layer. Examples of the thermoplastic resin include thermoplastic polyester resin, polyvinyl butyral resin, acrylic resin, phenol resin, thermoplastic polyurethane resin, and the like. Can be mentioned. In addition, when using a thermosetting resin, you may add a curing catalyst as needed. When using an ionizing radiation curable resin such as a photocurable resin, a polymerization initiator may be added as necessary.

  Further, in order to obtain fluidity suitable for filling the recesses of the intaglio, these resins are usually used as a varnish dissolved in a solvent or a dispersant. There is no restriction | limiting in particular in the kind of solvent or a dispersing agent, The solvent or dispersing agent generally used for printing ink can be used. The content of the solvent or dispersant is usually about 10% to 70% by weight, but it is preferably as small as possible within a range where necessary fluidity can be obtained. In addition, when an ionizing radiation curable resin such as a photocurable resin is used, it is inherently fluid and does not necessarily require a solvent or a dispersant.

  In addition, as the conductive powder constituting the conductive composition, other than the low resistivity metal powder such as gold, silver, platinum, copper, tin, palladium, nickel, aluminum, or the low resistivity metal as the core particle The surface of the powder made of material (metal powder other than the above low resistivity metal, resin powder such as acrylic resin, melamine resin, inorganic powder such as silica, alumina, barium sulfate, zeolite, etc.) is coated with a low amount of gold or silver as a coating material. Preferable examples include powder obtained by plating a resistivity metal, and powder of conductive carbon such as graphite and carbon black. Also, conductive ceramics or conductive organic polymer powders can be used. The shape can also be selected from spherical, spheroid, polyhedral, truncated polyhedral, scaly, disk-shaped, fibrous (or needle-shaped), and the like. These materials and shapes may be appropriately mixed and used. Since the size of the conductive powder is arbitrarily selected according to the type, it cannot be specified unconditionally. For example, in the case of scale-like silver powder, the powder having an average particle diameter of about 0.1 to 10 μm is used. In the case of carbon black powder, those having an average particle diameter of about 0.01 to 1 μm can be used.

  The content of the conductive powder in the conductive composition is arbitrarily selected according to the conductivity of the conductive powder and the form of the powder. For example, the conductive powder is based on the total solid content of the conductive composition. Can be contained in the range of 40 to 99% by weight. In the present application, the average particle diameter refers to a particle size distribution diameter or a value measured by TEM observation. In the case of an aspherical shape such as a polyhedral shape or a fibrous shape, the particle diameter is usually defined by the diameter of the circumscribed sphere, the diagonal length, or the side length of the longest side.

Further, an appropriate additive may be added to the conductive composition for the purpose of improving the quality. For example, carbon black is not necessary because it is black in itself, but by adding a predetermined amount of black pigment or black dye as needed, it prevents reflection of external light when an electromagnetic wave shielding sheet is configured, thereby improving contrast. The visibility can be improved. Further, in order to prevent reflection on the back surface of the transparent resin substrate due to the metallic luster of the metal layer, which will be described later, and to suppress color unevenness, metal color, etc., it is desirable to contain such a black pigment or black dye. Examples of black pigments include carbon blacks which also functions as a conductive _{powder, Fe 3 O 4, CuO-} Cr 2 O 3, CuOFe 3 O 4 -Mn 2 O 3, CoO-Fe 2 O 3 -Cr 2 O 3 and the like The type and shape are not particularly limited, and a black pigment or black dye having an average particle diameter of 0.1 μm or less that is easily dispersed in the binder resin and having a large coloring power is preferable. In addition, when using carbon black, carbon black for coloring materials such as channel black, furnace black or lamp black, conductive carbon black, acetylene black and the like can be mentioned, and among them, the average particle diameter is 20 nm or less. Is preferably used. As the black dye, a dye such as aniline black can be used. In addition, in order to improve the fluidity and stability of the conductive composition, as long as the conductivity and adhesion to the primer layer 2 are not adversely affected, fillers, thickeners, surfactants, and antioxidants are appropriately used. An agent or the like may be added.

  When the metal layer is used, the conductive mesh layer 3 is formed by etching the metal foil into a predetermined mesh shape. When the conductive composition is used, it is formed into a mesh by a printing method, particularly preferably by specific intaglio printing using a primer layer as described later. Hereinafter, the latter forming method will be described. First, after applying a conductive composition to the plate surface of a plate-like or cylindrical plate (intaglio plate) in which concave portions are formed in a predetermined mesh pattern, the conductive composition adhering outside the concave portions is scraped off. The conductive composition is filled in the recess. Next, the transparent resin base material sheet 1 in which the primer layer 2 retaining fluidity is formed on one surface is prepared. More specifically, a plate surface having a concave portion having a predetermined pattern is formed as the intaglio plate, and the opening cross-sectional area of the concave portion cut by a virtual plane parallel to the surface of the plate surface is reduced by the distance x from the surface. A plate-shaped or cylindrical plate having a function S (x) is prepared. Next, a conductive composition capable of forming the conductive mesh layer 3 after curing is applied to the plate surface, and then the conductive composition adhering to other than the inside of the concave portion is scraped off with a doctor blade, and the conductive portion is conductive in the concave portion. The active composition is filled. Next, the primer layer 2 side of the transparent resin substrate sheet 1 and the plate surface filled with the conductive composition in the recesses are pressure-bonded to bring the conductive composition and the primer layer 2 into close contact with each other without gaps, In this state, the flowability of the primer layer 2 is eliminated (cured), and then the conductive composition is transferred onto the primer layer 2 so that the conductive composition layer having a predetermined mesh pattern is formed on the primer layer. To form. In addition, after transferring the conductive composition layer onto the primer layer 2, the conductive composition is subjected to curing treatment (for example, drying treatment, ultraviolet ray / electron beam irradiation treatment, heat treatment, cooling treatment, etc.). A conductive mesh layer 3 is formed.

In the present invention, as described above, when excessive conductive composition other than the inside of the recess is scraped off by the doctor blade, the inside of the undesired recess 6 inevitably generated on the upper portion of the conductive composition in the recess. In addition, the primer layer 2 that retains fluidity is filled and the primer layer 2 is cured in a state where the conductive composition and the primer layer 2 are in close contact with each other without gaps, so that the conductive composition is poorly transferred onto the primer layer 2. Can be transferred.
Moreover, since the transferability of the conductive composition can be improved, the thickness of the conductive composition after transfer can be increased as compared with a method using intaglio such as normal gravure printing. Therefore, by increasing the mesh pattern, it is possible to ensure the conductivity necessary for the electromagnetic wave shield.

  In the above, what was mainly comprised with electroconductive powder and resin was demonstrated as an electroconductive composition. The conductive composition itself becomes the conductive mesh layer 3, but other conductive compositions may be applied in the present invention. For example, a conductive mesh layer 3 made of a conductive metal or metal compound is prepared by using a sol (dispersion liquid) of an organometallic compound as a conductive composition, heated and solidified before and after the transfer step, and further fired as necessary. It is good. Further, for example, a known conductive resin such as polythiophene may be used as the conductive composition, and the conductive mesh layer 3 itself may be used.

[Form of conductive mesh layer]
FIG. 2 is an explanatory diagram of a cross-sectional area of the conductive mesh layer 3 cut along a virtual plane parallel to the transparent resin base sheet 1. In the present invention, the conductive mesh layer 3 after the transfer has a cross-sectional area cut along a virtual plane P parallel to the surface of the transparent resin base sheet 1 and a decreasing function S () of the distance x from the transparent resin base sheet 1 x). As shown in FIG. 2B, the distance x from the transparent resin substrate sheet 1 is not the surface of the primer layer 2 but the surface of the transparent resin substrate sheet 1 excluding the primer layer 2. The distance measured toward the direction away from the base material sheet 1 (upward in FIG. 2B). The cross-sectional area is compared with the cross-sectional area in the range of the predetermined length y in the line direction of the conductive mesh layer 3. Actually, for example, as shown in FIG. 2 (A), the measurement sample piece 20 cut out from the electromagnetic wave shielding sheet within a predetermined length y (for example, 50 μm) is embedded in the hardened resin for polishing, and FIG. 2 (B). As shown in Fig. 2, after being cured, it is polished so as to be parallel to the transparent resin substrate sheet 1, and the cross-sectional area at the virtual plane P is measured and evaluated with a microscope.

  FIG. 3 is a perspective view showing a spatial shape of the concave portion 54 of the plate surface 53 filled with the conductive composition. The cross-sectional shape of the conductive mesh layer 3 described above is the same as the space shape of the concave portion 54 of the printing plate 53 filled with the conductive composition. That is, the intaglio plate 52 filled with the conductive composition has a plate surface 53 having a concave portion 54 having a predetermined pattern, and the opening cross-sectional area of the concave portion 54 cut by a virtual plane P parallel to the surface of the plate surface 53 It is a decreasing function S (x) of the distance x from the surface. The distance x from the surface means a distance measured from the surface of the plate surface 53 toward the inside of the plate (upward in FIG. 2B) as shown in FIG. Therefore, the concave portion 54 of the plate surface 53 is filled with the conductive composition, and the conductive composition is transferred onto the primer layer 2 as the conductive mesh layer 3 at a high transfer rate. Then, it is transferred onto the primer layer 2 with the same sectional shape as the opening sectional shape of the recess 54.

  FIG. 4 is a specific example of the cross-sectional shape of the conductive mesh layer 3. As shown in FIG. 4, the cross-sectional shape perpendicular to the line direction of the conductive mesh layer 3 is trapezoidal (tetragonal), triangular, polygonal (pentagonal pentagon, hexagon, etc.), semi-elliptical, Any one selected from a parabolic shape, a sinusoidal shape, and similar shapes can be cited. Each of these shapes has a decreasing function S (x) of the distance x from the transparent resin substrate sheet 1 as a cross-sectional area cut along a virtual plane P parallel to the transparent resin substrate sheet 1.

For example, in the trapezoid shown in FIG. 4A, a trapezoid in which the angles α and α ′ on the bottom side are 20 ° to 85 ° and the angles β and β ′ on the top side are 95 ° to 160 °. Can be illustrated. In addition, in the triangle shown in FIG. 4B, a triangle having both the base side angles α and α ′ of 20 ° to 75 ° and the apex angle β of 30 ° to 140 ° can be exemplified. Further, in the pentagon shown in FIG. 4C, the angles α and α ′ on the base side are 20 ° to 85 ° and the angle β on the top is 30 ° to 170 °. A pentagon having an angle of '105 ° to 170 ° can be exemplified. Further, in the hexagon shown in FIG. 4D, the angles of the base side angles α, α ′ are 20 ° to 85 °, and the angles β, β ′ of the upper side angles are 95 ° to 160 °, An example is a hexagon in which the angles γ and γ ′ between the two angles are 105 ° to 170 °. Table In the semi-elliptical shown in FIG. 4 (E), the horizontal coordinate of the cross-section x, a vertical coordinate upon the ^{y, x 2 / a 2 +} y 2 / b 2 = 1, by the formula The semi-elliptical shape can be illustrated. The flatness of the ellipse is about 1/5 ≦ b / a ≦ 5/1 when evaluated by b / a. In addition, in the parabola shown in FIG. 4F, when the horizontal coordinate of the cross section is assumed to be x, and the vertical coordinate is assumed to be y, a parabola represented by the equation y = ax ² can be exemplified. In addition, in the sinusoidal shape shown in FIG. 4G, a curve represented by the equation y = asinbx can be exemplified when the horizontal coordinate of the cross section is x and the vertical coordinate is y.

  The present invention is not limited to the specific example of the cross-sectional shape shown in FIG. 4 and may have a cross-sectional shape having other angles. Also, α and α ′, β and β ′, and γ and γ ′ may be the same angle or different angles. Examples of cross-sectional shapes other than those shown in FIG. 4 include hyperbola, hyperbolic sine (or cosine) curve, normal distribution curve, elliptic function curve, Bessel function curve, cycloid curve, etc. it can.

  When the conductive mesh layer 3 having the above-described cross-sectional shape is laminated on the conductive mesh layer 3 with an optical filter having an adhesive layer to be described later, the conductive mesh layer 3 and the adhesive layer There is an effect that the air bubbles are easily removed and the air bubbles hardly remain in the pressure-sensitive adhesive layer.

  In the present invention, the ratio of the line width W of the base portion of the conductive mesh layer 3 to the height H from the base portion of the conductive mesh layer 3 (H / W: aspect ratio, FIG. (See FIG. 4A) is preferably 0.2 or more. By setting the aspect ratio (H / W) of the conductive mesh layer 3 to 0.2 or more, the ratio of the conductive composition in the cross section increases, so that the conductivity of the conductive mesh layer 3 can be increased. There is an advantage that the electromagnetic wave shielding property of the electromagnetic wave shielding sheet can be further improved. When the aspect ratio of the conductive mesh layer 3 is less than 0.2, the ratio of the conductive composition in the cross section is relatively small, so that the conductive mesh layer 3 can have sufficient conductivity. In addition, the electromagnetic shielding properties of the electromagnetic shielding sheet may be inferior. From the viewpoint of achieving both conductivity and transmission visibility, a more preferable value of the aspect ratio (H / W) of the conductive mesh layer 3 is 0.4 or more. In addition, although the upper limit of the aspect ratio (H / W) of the electroconductive mesh layer 3 is not specifically limited, For example, less than 2.0 can be mentioned from the viewpoint of the transferability in this system.

  The line width W of the base portion of the conductive mesh layer 3 is the distance between two intersections between the flat surface of the primer layer 2 and the contour of the conductive mesh layer 3 protruding on the primer layer 2. That is. Further, the height H from the base of the conductive mesh layer 3 is the height from the intersection point to the top of the conductive mesh layer 3 (distance in the normal direction of the transparent resin base sheet 1). .

[Mesh pattern cross section]
Next, the mesh pattern form of the conductive mesh layer 3 formed on the primer layer 2 will be described. Hereinafter, the form is also referred to as “mesh pattern 19”. 5 to 7 are schematic cross-sectional views showing first to third forms of the mesh pattern 19 (19A to 19C). In the present invention, the mesh pattern 19 includes the primer layer 2 and the conductive mesh layer 3 formed in a predetermined pattern on the primer layer 2. In any of the mesh patterns 19A to 19C, the thickness TA of the primer layer 2 where the conductive mesh layer 3 is formed is equal to the thickness of the primer layer 2 where the conductive mesh layer 3 is not formed. It is thicker than TB. Such a form has an effect derived from the form that the adhesion between the primer layer 2 and the conductive mesh layer 3 is excellent as compared with the case where the conductive mesh layer 3 is formed on the primer layer 2 having a flat surface. Further, such a form is caused by the manufacturing method as described above, and when the excess conductive composition other than the inside of the concave portion is scraped off by the doctor blade on the intaglio plate surface, A dent 6 tends to be formed on the upper part of the adhesive composition, and the primer layer 2 having fluidity is filled in the dent 6 by press-bonding the primer layer 2 to the plate surface with the dent 6, and after curing, This is caused by peeling. The mesh pattern 19A of the first form is such that the primer layer 2 is in close contact with the conductive mesh layer 3 (conductive composition 15) without voids, and the disconnection is based on poor transfer of the conductive mesh layer 3 (conductive composition 15). It can be set as the electromagnetic wave shielding sheet which does not produce defects, such as a shape defect and low adhesiveness.

  As shown in FIG. 5, the mesh pattern 19A of the first form is such that the interface 12 between the primer layer 2 and the conductive mesh layer 3 is alternately arranged on the primer layer 2 side and the conductive mesh layer 3 side. is there. In this embodiment, the interface 12 may be configured to be an interface between the resin constituting the primer layer 2 and the resin or filler constituting the conductive mesh layer 3. The “filler” in this case is an arbitrary powder and may be a conductive powder or a non-conductive powder. For example, when the conductive composition is composed of a conductive powder and a binder resin, the interface 12 is complicated by the conductive powder in the conductive mesh layer 3 and the resin constituting the primer layer 2. Formed in a manner. The degree of intricacy at this time depends on the shape and size of the conductive powder. In addition, for example, when the conductive composition does not contain a filler and contains a conductive resin or a conductive compound, the primer layer 2 and the conductive mesh are caused by the pressure when the primer layer 2 is pressure-bonded into the recess. The interface with the layer 3 is intricate. In the mesh pattern 19A of the first form, the complicated interface 12 has a mountain-shaped cross-sectional shape with a high center as a whole (an envelope surface or a virtual curved surface obtained by smoothing complicated irregularities).

  The mesh pattern 19A of the first form has good adhesion even if the conductive mesh layer 3 is formed on the mountain-shaped primer layer 2 which is not a flat surface in the first place, Thus, since the interface 12 is in a complicated form, the adhesion between the primer layer 2 and the conductive mesh layer 3 is remarkably increased due to the so-called anchoring effect. Furthermore, when forming the mesh pattern 19A, the conductive composition filled in the plate recess is transferred to the primer layer 2 with a very high transfer rate (approximately 100%). Yes.

  As shown in FIG. 6, the mesh pattern 19B of the second form constitutes a conductive mesh layer and a primer component contained in the primer layer 2 in the vicinity of the interface 12 between the primer layer 2 and the conductive mesh layer 3. It is the form where the area | region 14 with which a component mixes exists. Although the interface 12 is clearly expressed in FIG. 6, in the actual mixed region 14, the interface 12 does not appear clearly, and an unclear and ambiguous interface appears. In FIG. 6, the mixed region 14 exists so as to sandwich the interface 12 vertically. In this case, a primer component (for example, a solvent) in the primer layer 2 and an arbitrary component (for example, a monomer component) in the conductive mesh layer 3 penetrate into each other. Note that the mixed region 14 may exist above or below the interface 12. In the case where the mixed region 14 exists above the interface 12, the primer component in the primer layer 2 penetrates into the conductive mesh layer 3, and any component in the conductive mesh layer 3 penetrates into the primer layer 2. On the other hand, when the mixed region 14 exists below the interface 12, any component in the conductive mesh layer 3 enters the primer layer 2, and the primer component in the primer layer 2 This is a case where the conductive mesh layer 3 does not enter. The thickness of the mixed region 14 (the thickness in the vertical direction in FIG. 6) is not particularly limited.

  As in the case of the first embodiment, the mesh pattern 19B of the second embodiment also has adhesion even if the conductive mesh layer 3 is formed on the mountain-shaped primer layer 2 that is not a flat surface. In addition, since the mixed region 14 is provided in the vicinity of the interface 12 as described above, the adhesion between the primer layer 2 and the conductive mesh layer 3 is remarkably enhanced. Furthermore, when forming the mesh pattern 19B, the conductive composition filled in the plate recess is transferred to the primer layer 2 with an extremely high transfer rate (approximately 100%). Yes.

  As shown in FIG. 7, the mesh pattern 19 </ b> C of the third form is a form in which the primer component 16 included in the primer layer 2 is present in the conductive composition constituting the conductive mesh layer 3. FIG. 7 schematically shows an aspect in which the primer component 16 is large near the interface 12 and decreases toward the top, but is not particularly limited to such an aspect. In short, the primer component 16 includes the conductive mesh layer. 3 only needs to be present. The primer component 16 may penetrate into the conductive mesh layer 3 to the extent that it is detected from the top of the conductive mesh layer 3 or may be detected to the vicinity of the interface 12. In the third embodiment, in particular, when the region where the primer component 16 is present in the conductive mesh layer 3 is localized in the vicinity of the interface 12, the mixed region 14 is the interface 12 in the second embodiment. It can be said that it corresponds to a form existing only on the upper side.

  As in the case of the first and second forms, the mesh pattern 19C of the third form is formed by forming the conductive mesh layer 3 on the mountain-shaped primer layer 2 that is not a flat surface. In addition to the good adhesion, the primer component 16 penetrates to the extent that it exists in the conductive mesh layer 3 as described above, so the adhesion between the primer layer 2 and the conductive mesh layer 3 is remarkably increased. ing. Furthermore, when forming such a mesh pattern 19C, the conductive composition filled in the plate recess is transferred to the primer layer 2 with an extremely high transfer rate (approximately 100%). Yes.

  In the present invention, at least one of the features of the mesh pattern 19 of the first to third embodiments described above is included, but two or more of these features may be included, and all three are included. May be.

(Metal layer formed on the conductive composition layer)
If the metal layer formed on the conductive mesh layer made of the conductive composition layer is insufficient for the desired conductivity only with the conductive mesh layer 3, it is necessary to further improve the conductivity. To form. Usually, it is formed on the conductive mesh layer 3 by plating. As plating methods, there are methods such as electrolytic plating, electroless plating, etc. Electroplating can increase the plating speed several times by increasing the amount of current compared to electroless plating, which significantly improves productivity. It is preferable because it can be used.

  In the case of electrolytic plating, power feeding to the conductive mesh layer 3 is performed from an electrode such as a current-carrying roll brought into contact with the surface on which the conductive mesh layer 3 is formed. Since it has conductivity (for example, 100Ω / □ or less), electrolytic plating can be performed without any problem. Examples of the material constituting the metal layer include copper, silver, gold, chromium, nickel, and tin, which are highly conductive and can be easily plated. Since the metal layer generally has a volume resistivity smaller than that of the conductive mesh layer 3 by one digit or more, the amount of necessary conductive material can be reduced compared to the case where the conductive mesh layer alone secures electromagnetic wave shielding. There is an advantage.

  Note that after the metal layer is formed, the metal layer may be blackened or a protective layer may be provided as necessary. Examples of the blackening treatment include blackening nickel plating and copper-cobalt alloy plating, and the protective layer can be formed using, for example, an acrylic photocurable resin.

(B) The process of preparing a continuous strip-shaped optical filter The process (B) is a process of preparing a continuous strip-shaped optical filter having an adhesive layer on one surface of the second transparent resin base sheet provided with an optical function. It is.
In this step, first, a second transparent resin base sheet provided with an optical function (hereinafter, also simply referred to as “transparent resin base sheet”) is prepared, and on one surface of the transparent resin base sheet, An adhesive layer is provided.

As a method of imparting a function to the transparent resin substrate sheet, a method of laminating an optical functional layer on one surface or both surfaces of the second transparent resin substrate sheet, or in the second transparent resin substrate sheet There is a method of adding a material having an optical function. As a method of laminating such optical functional layers, there are a wet film forming method and a dry film forming method. For example, when the wet film-forming method is used, a layer-forming coating solution is prepared by diluting a constituent material of each layer having various optical functions, which will be described later, with a solvent as necessary. The layer-forming coating solution can be formed by coating (for example, 10 g / m ² ) on one surface of a continuous belt-shaped transparent resin substrate sheet by various coating methods such as a gravure reverse method. Examples of dry film forming methods include, for example, vacuum evaporation, sputtering, ion plating, chemical vapor deposition (CVD), electrolysis or electroless plating, thermal spraying, and the like, of materials having various optical functions. Is laminated on one surface of the continuous strip-shaped transparent resin substrate sheet by the above method.
As a method of adding such a material having an optical function, for example, a resin material component constituting the second transparent resin base sheet and a material having an optical function are mixed, and a composition that is appropriately dispersed or dissolved is mixed. It can form into a 2nd transparent resin base material sheet | seat by a well-known appropriate method.

Moreover, it does not specifically limit as a method of providing an adhesive layer in the one surface of the said transparent resin base material sheet, ie, a to-be-adhered surface, The method of coating an adhesive layer directly using various coating methods And a method in which a pressure-sensitive adhesive layer separately molded into a sheet is pasted together. Any method can be used in the present invention. Examples of the coating method include a roll coater, a die coater, a blade coater, a comma coater, and screen printing. As a bonding method, a bonding method similar to that described in the later-described step (D) can be used.
Further, since the formed pressure-sensitive adhesive layer has a coating function, until it is actually bonded to the electromagnetic wave shielding sheet, a temporary treatment such as a silicone-treated easy-peelable PET film or the like is used to prevent inadvertent adhesion. It is preferable to laminate a protective film (referred to as a release sheet or a separator).

Hereinafter, the optical filter used in the present invention will be described in order from the second transparent resin base sheet.
(Second transparent resin base sheet)
As a 2nd transparent resin base material sheet used for an optical filter, the transparent resin base material sheet similar to having described in the 1st transparent resin base material sheet used for an electromagnetic wave shielding sheet can be used.

(Optical function)
Although the function which comprises the optical filter of this invention is not specifically limited, There exist near-infrared absorption, ultraviolet absorption, neon light absorption, color tone adjustment (coloring), anti-glare, antireflection, etc. In addition to the optical function, the optical filter of the present invention may have other functions other than the optical function as necessary. Other functions include an abrasion resistance function, an antistatic function, an antifouling function, an impact resistance function, a viewing angle regulation function, an antibacterial function, an antifungal function, and the like. Such other functions are also imparted by laminating an independent layer on the second transparent resin base sheet or adding it to the inside. When such an optical function or other functions are realized by stacking functional layers, the functional layer may be one layer or two or more layers, and each layer may have a plurality of different functions. An adhesive layer may be provided between each functional layer.

Hereinafter, each function will be described by exemplifying a form in which this function is provided by stacking functional layers. For example, the near-infrared absorbing layer or the like means a layer provided with a near-infrared absorbing function that is laminated on the second transparent resin base sheet.
(1) Near-infrared absorption layer As a near-infrared absorption layer, a near-infrared absorption pigment | dye can be contained in binder resin and it can form by wet film-forming methods, such as coating, on the said transparent resin base material sheet. As the near-infrared absorbing dye, when an optical filter is applied to the front surface of a plasma display panel, which is a typical application, the plasma display panel generates a near-infrared region, that is, 800 nm generated when light is emitted using a xenon gas discharge. It is preferable that the near-infrared transmittance of the wavelength region of ˜1100 nm is 20% or less, more preferably 10% or less. At the same time, it is desirable that the near-infrared absorbing layer has a sufficient light transmittance in the visible light region, that is, in the wavelength region of 380 nm to 780 nm. Specific examples of near-infrared absorbing dyes include polymethine compounds, cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, naphthoquinone compounds, anthraquinone compounds, imonium compounds, diimonium compounds, aminium compounds, pyrylium. Compounds, cerium compounds, squarylium compounds, copper complexes, nickel complexes, dithiol metal complexes organic near infrared absorbing dyes, tin oxide, indium oxide, tungsten hexachloride, cesium-containing tungsten oxide, aluminum oxide, One or two or more inorganic near-infrared absorbing dyes composed of particles such as zinc oxide and iron oxide can be used in combination. As the binder resin, a resin such as a polyester resin, a polyurethane resin, an acrylic resin, or an epoxy resin is used. The binder resin can be dried and cured by drying and solidifying by drying a solvent (or dispersion medium) from a solution (or emulsion), polymerization by energy such as heat, ultraviolet rays and electron beams, and a curing method using a crosslinking reaction. Alternatively, a curing method using a reaction such as crosslinking or polymerization between a functional group such as a hydroxyl group or an epoxy group in a resin and an isocyanate group in a curing agent can be applied.
Alternatively, the near-infrared absorption layer may be formed by vacuum deposition, sputtering, chemical vapor deposition of a material having near-infrared absorption performance such as aluminum, gold, silver, copper, indium tin oxide (ITO), or the above-described inorganic near-infrared absorbing dye. It can also be formed by laminating on the surface of the second transparent resin substrate sheet by a dry film forming method such as a deposition method. However, in the application of the present invention, since it is necessary to transmit visible light sufficiently, the thickness of these layers is set to a thickness capable of transmitting visible light sufficiently. Although it depends on the material, it is generally less than 380 nm which is the shortest wavelength of visible light.

(2) Ultraviolet absorbing layer The ultraviolet absorbing layer can be formed, for example, by dispersing an ultraviolet absorber in a binder resin. Examples of the ultraviolet absorber include organic compounds such as benzotriazole and benzophenone, and inorganic compounds composed of particulate zinc oxide, cerium oxide, and the like. As the binder resin, the resins mentioned in the near infrared absorption layer can be used.

(3) Anti-glare layer Anti-glare layer (Anti Glare layer, abbreviated as AG layer) is formed by coating with an inorganic filler such as silica in a binder resin, or by shaping using a shaping plate Thus, the layer surface can be formed as a layer provided with fine irregularities for irregularly reflecting external light. As the binder resin, a curable acrylic resin, an ionizing radiation curable resin, or the like is preferably used in the same manner as the hard coat layer described later because surface strength is desired as the surface layer.

(4) Antireflective layer The antireflective layer (Anti Reflection layer, abbreviated as AR layer) is a low refractive index layer or a low refractive index layer and a high refractive index layer. A multilayer structure in which layers are alternately stacked so as to be positioned at the uppermost layer is generally used, and can be formed by a dry film formation method such as vapor deposition or sputtering, or by using a wet film formation method such as coating. The low refractive index layer is made of silicon oxide, magnesium fluoride, aluminum fluoride, cryolite, fluorine-containing resin, etc., and the high refractive index layer is made of titanium oxide, zinc sulfide, zirconium oxide, niobium oxide, etc. Is used. Here, the high (low) refractive index layer means that the refractive index of the layer is relatively high (low) compared to a layer adjacent to the layer (for example, a low (high) refractive index layer). Meaning.
When the antireflection layer is further provided with a scratch resistance function, the antireflection layer is appropriately formed using a material having high hardness described in the section of the scratch resistance function (hard coat) layer described later.

(5) Scratch-resistant functional layer The scratch-resistant (hard coat) layer has a hardness of “H” or higher in a pencil hardness test (500 g load) defined by JISK5600-5-4 (1999). The material is not particularly limited as long as such hardness and transparency similar to the transparent resin substrate can be realized.
The scratch-resistant layer (hard coat) layer is, for example, a polyfunctional (meth) acrylate prepolymer such as polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, or trimethylolpropane tri (meth) acrylate. , Pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and other polyfunctional (meth) acrylate monomers such as tri- or more functional compounds, either alone or in combination of two or more of these It can be formed as a coating film using a curable resin. Further, when an ionizing radiation curable resin is used as an ultraviolet curable resin, a sensitizer can be added as a photopolymerization initiator or a photopolymerization accelerator. The scratch resistance function (hard coat) can be formed by a wet film formation method such as coating on the transparent resin substrate sheet by diluting the material with a solvent as necessary.

(6) Other layers Examples of other layers include a neon light absorbing layer, a color tone adjusting layer, and an antifouling layer. However, from the viewpoint of production efficiency, the neon light absorbing layer and the color tone adjusting layer are combined with the above-mentioned near infrared absorbing layer containing the neon light absorbing dye and the color tone adjusting dye, rather than being formed as a single layer. A layer is preferred.
Examples of the neon light absorbing dye include cyanine, oxonol, methine, subphthalocyanine or porphyrin.
Examples of known dyes that can be used as the color tone adjusting dyes include the dyes described in JP 2000-275432 A, JP 2001-188121 A, JP 2001-350013 A, JP 2002-131530 A, and the like. Can be suitably used. In addition, other dyes such as anthraquinone, naphthalene, azo, phthalocyanine, pyromethene, tetraazaporphyrin, squarylium, and cyanine that absorb visible light such as yellow light, red light, and blue light. Can be used.
The antifouling layer is generally a water-repellent or oil-repellent coat, and a siloxane-based, fluorinated alkylsilyl compound or the like can be applied. A fluorine-based or silicone-based resin used as a water-repellent paint can be preferably used. For example, when the low refractive index layer of the antireflection layer is formed of SiO ₂ , a fluorosilicate water-repellent paint is preferably used.

(Adhesive layer)
The pressure-sensitive adhesive layer used in the present invention is provided on the adhesion surface of the optical filter in order to bond the optical filter and the electromagnetic wave shielding sheet while filling the unevenness of the conductive mesh layer of the electromagnetic wave shielding sheet.

(1) Pressure-sensitive adhesive Pressure-sensitive adhesive refers to one type of adhesive, and is only moderately pressured, usually lightly pressed by hand at room temperature (for example, 15 to 40 ° C.) during bonding. According to the above, it can be adhered only by the tackiness of the surface.
The pressure-sensitive adhesive used in the present invention is not particularly limited as long as it achieves film forming properties, transparency, and pressure-sensitive adhesive properties, and various conventionally known pressure-sensitive adhesives can be appropriately selected and used. The higher the transparency as the pressure-sensitive adhesive layer is, the better. However, the light transmittance in the visible light region of 380 to 780 nm is preferably 70% or more, more preferably 80% or more. Furthermore, the pressure-sensitive adhesive layer of the present invention also functions as an impact resistant layer by optimizing the pressure-sensitive adhesive and thickness used.

  Examples of the adhesive include natural rubber, synthetic rubber, acrylic resin (hereinafter also abbreviated as acrylic), silicone resin, polyester resin, and the like. Specific examples of synthetic rubbers include styrene-butadiene rubber, acrylonitrile-butadiene rubber, and polyisobutylene rubber. These pressure-sensitive adhesives can be used alone or in combination of two or more.

  An acrylic adhesive is mentioned as an adhesive suitably used. The acrylic pressure-sensitive adhesive is a polymer containing at least a (meth) acrylic acid alkyl ester monomer. A copolymer of a (meth) acrylic acid alkyl ester monomer having an alkyl group having about 1 to 18 carbon atoms and a monomer having a carboxyl group, or (meth) acrylic acid having an alkyl group having about 1 to 18 carbon atoms A copolymer using two or more kinds of alkyl ester monomers is generally used. Here, (meth) acrylic acid means acrylic acid and / or methacrylic acid.

  Examples of (meth) acrylic acid alkyl ester monomers used here include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, etc. Can be mentioned.

(2) Other components The pressure-sensitive adhesive layer in the present invention may contain a crosslinking agent such as an isocyanate compound, a tackifier, and the like as desired. In addition, the pressure-sensitive adhesive layer may contain an antioxidant such as a benzotriazole-based compound, various surfactants, a silane coupling agent, and the like.

(C) Step of heating the pressure-sensitive adhesive layer Step (C) is a step of heating at least the pressure-sensitive adhesive layer of the continuous band-shaped optical filter. The temperature at the time of a heating is 60-100 degreeC normally, Preferably it is 90-100 degreeC.
Examples of the method of heating the pressure-sensitive adhesive layer in the above temperature range include a method of allowing the optical filter to pass through the surface of a heating roll or a heating furnace. When using a heating roll, the surface temperature of the heating roll is preferably 70 to 105 ° C, and more preferably 90 to 100 ° C. Moreover, when using a heating furnace, it is preferable to set the temperature of this heating furnace to 70-110 degreeC, and also it is preferable to set to 90-100 degreeC.
Moreover, although the material of a heating roll is not specifically limited, From the point which makes the surface temperature of this heating roll 70-105 degreeC, it is preferable that they are metals, such as iron and copper. Such a metal roll has a desired temperature by making the inside hollow and circulating a heating medium such as heated steam and hot water, irradiating infrared rays, or using induction heating by an alternating magnetic field. Heat to.

In this step, by heating the pressure-sensitive adhesive layer of the optical filter at 60 to 100 ° C., the gas contained in the pressure-sensitive adhesive layer is expelled, the viscosity of the pressure-sensitive adhesive layer is lowered, the adhesiveness is increased and the conductivity is increased. It is possible to facilitate the inflow of the conductive mesh layer into the recess and the replacement with the air present therein. When the heating temperature of the pressure-sensitive adhesive layer is less than 60 ° C., the gas contained in the pressure-sensitive adhesive layer cannot be sufficiently expelled, and bubbles are mixed into the pressure-sensitive adhesive layer. When the heating temperature of the pressure-sensitive adhesive layer exceeds 100 ° C., the substrate temperature may exceed the softening point, and in the worst case, the substrate and / or the pressure-sensitive adhesive may be thermally damaged.
In addition, by heating the pressure-sensitive adhesive layer in the above temperature range, the viscosity of the pressure-sensitive adhesive layer can be set within the range of 150,000 to 200,000 cps (estimated because of no measurement).

(D) A step of obtaining a continuous band-shaped composite sheet by bonding the adhesive layer through the pressure-sensitive adhesive layer while cooling the pressure-sensitive adhesive layer. In step (D), at least the pressure-sensitive adhesive layer of the continuous band-shaped optical filter is cooled. On the other hand, the adhesive layer side surface of the continuous band-shaped optical filter is bonded to the conductive mesh layer side surface of the continuous band-shaped electromagnetic wave shielding sheet to obtain a continuous band-shaped composite sheet.
The temperature at the time of such cooling is 40-55 degreeC normally, Preferably it is 42-48 degreeC.
Such cooling is started at the time when the pressure-sensitive adhesive layer and the conductive mesh layer are in contact with each other and at an appropriate time thereafter, and is maintained for an appropriate period of time. For example, the cooling start time is either the moment when the pressure-sensitive adhesive layer and the conductive mesh layer are in contact with each other or the time when the pressure-sensitive adhesive layer and the conductive mesh layer are in contact with each other at a certain interval. It is possible. The cooling time is also usually between a few seconds and a few minutes. The specific cooling start time and cooling time are appropriately set according to the actual structure and state of the processing machine, the type of each material to be laminated, and the like.
By cooling the pressure-sensitive adhesive layer in the above temperature range, it is possible to prevent unnecessary flow of the pressure-sensitive adhesive layer and leakage from the edge of the laminate, while maintaining the pressure-sensitive adhesive layer. It can be controlled so that no new gas is generated from the pressure-sensitive adhesive layer. When the cooling temperature of the pressure-sensitive adhesive layer is lower than 40 ° C., the viscosity of the pressure-sensitive adhesive layer becomes high before the pressure-sensitive adhesive layer sufficiently flows into the recesses of the conductive mesh layer, and the electromagnetic wave shielding sheet, the optical filter, Inadequate adhesion. When the cooling temperature of the pressure-sensitive adhesive layer exceeds 55 ° C., gas continues to be generated from the pressure-sensitive adhesive layer, and bubbles are mixed into the pressure-sensitive adhesive layer.
In addition, by cooling the pressure-sensitive adhesive layer in the above temperature range, the viscosity of the pressure-sensitive adhesive layer can be set within the range of 250,000 to 300,000 cps (estimated because of no measurement).

  The method for bonding the continuous band-shaped electromagnetic wave shielding sheet and the continuous band-shaped optical filter via an adhesive layer is not particularly limited.

The laminator (lamination sticking machine) may be a roll type, a flat plate type, etc., as long as it can pressurize the optical filter and the electromagnetic wave shielding sheet, but unwinds the electromagnetic wave shielding sheet and the optical filter from the roll. It is easy to cope with the method of winding again on the roll after bonding (also referred to as “roll-to-roll processing method”) and to prevent air bubbles from being mixed into the adhesive layer. It is preferable to use a roll-type laminator from the possible point.
Although the pressurization at the time of lamination is not particularly limited, for example, when a roll laminator is used, the linear pressure is preferably 1 to 20 kgf / cm. Moreover, the surface temperature of the bonding roll (cooling roll) at the time of lamination | stacking is
It is preferably 40 to 50 ° C, and more preferably 42 to 48 ° C.
Moreover, although the material of a bonding roll is not specifically limited, Since a sheet | seat becomes slippery when both two rolls are metal, it is preferable that the surface of at least one roll is rubber | gum (a core is metal). .

  FIG. 9 is an example of a lamination process of an electromagnetic wave shielding sheet and an optical filter using a laminator. A sheet in which an electromagnetic wave shielding sheet is wound around the first sheet feeding unit 61 of the laminator, and a laminated sheet composed of a release film / (adhesive layer side) optical filter is wound on the second sheet feeding unit 62 Place. Next, while feeding out the electromagnetic wave shielding sheet from the first paper feeding unit 61, on the other hand, the laminated sheet composed of the release film / optical filter is fed out from the second paper feeding unit 62 and at the same time, the release film is taken up on the take-up roll 63. . Next, the surface of the optical filter with the pressure-sensitive adhesive layer exposed on the surface of the optical filter on which the pressure-sensitive adhesive layer is not formed is passed through a heating roll 64 made of iron (coated with a surface fluororesin) having a surface temperature of 100 ° C. The optical filter is laminated with a laminating roll (cooling roll) 65 having a surface temperature of 45 ° C. with a laminating pressure of about 10 kgf / cm, wound around the take-up roll 66, and from the electromagnetic wave shielding sheet / adhesive layer / optical filter. A laminated sheet is obtained. The ambient temperature around the laminator at this time is 23 ° C. After the lamination step is completed, the winding roll 66 is left in the atmosphere, and is cooled from 45 ° C. immediately after the lamination to 23 ° C. of the ambient temperature (room temperature) by natural cooling by heat conduction to reach thermal equilibrium.

(E) Step of making the continuous strip-shaped composite sheet into single sheets The composite sheet may be distributed in the form of a continuous strip, but finally it is made into a single sheet as a composite filter for display for one display. To do. The single filter means of the composite filter is not particularly limited, and various types of filter cutting means can be used.

  According to the method for producing a composite filter of the present invention including the above-described steps, the surface of the electromagnetic wave shielding sheet on the conductive mesh layer side is directed through the pressure-sensitive adhesive layer with the adherence surface on the substrate side of the optical filter facing the surface. Before combining, heating the pressure-sensitive adhesive layer of the optical filter in the specific temperature range expels the gas contained in the pressure-sensitive adhesive layer and lowers the viscosity of the pressure-sensitive adhesive layer to increase the adhesiveness. be able to. Next, by cooling the pressure-sensitive adhesive layer heated to a high temperature within the above specific temperature range, control is performed so that gas is not generated from the pressure-sensitive adhesive layer while maintaining the pressure-sensitive adhesive layer. Can do. Therefore, after the pressure-sensitive adhesive layer is heated to a high temperature, the electromagnetic wave shielding sheet is bonded to the surface of the electromagnetic shielding sheet facing the conductive mesh layer while being cooled to an appropriate temperature. While improving the adhesiveness of a sheet | seat and this optical filter, a bubble is not mixed in this adhesive layer, but the raise of a haze can be suppressed. Moreover, since the process of heating and laminating in a vacuum atmosphere using an autoclave or the like, which has been conventionally used for preventing air bubbles from being mixed into the pressure-sensitive adhesive layer, is unnecessary, the equipment burden can be reduced.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

It is typical sectional drawing which expands and shows a part of electromagnetic wave shielding sheet of this invention. It is explanatory drawing of the cross-sectional area of the electroconductive mesh layer cut | disconnected by the virtual surface parallel to a transparent resin base material sheet. It is a perspective view which shows the space shape of the recessed part of the printing plate filled with an electroconductive composition. It is a specific example of the cross-sectional shape of a conductive mesh layer. It is a schematic cross section which shows the electroconductive mesh layer in a 1st form. It is a schematic cross section which shows the electroconductive mesh layer in a 2nd form. It is a schematic cross section which shows the electroconductive mesh layer in a 3rd form. In the process of forming the electroconductive mesh layer of this invention, it is a schematic diagram which shows the form which fills the dent of the electroconductive composition in a recessed part with a primer layer, and this electroconductive composition transfers. It is process drawing which shows an example of the lamination | stacking process of an electromagnetic wave shielding sheet and an optical filter among the manufacturing methods of the composite filter of this invention.

Explanation of symbols

1 Transparent resin base sheet (first transparent resin base sheet)
2 Primer layer 3 Conductive mesh layer 3 ′ Conductive composition layer 5 Side edge 6 Recess 12 Interface between primer layer and conductive mesh layer 14 Mixed region 15 Conductive composition 16 Primer component 19A, 19B, 19C Mesh pattern 20 Measurement sample piece 52 Intaglio plate 53 Plate surface 54 Recess portion 61 First paper feed portion 62 Second paper feed portion 63 Release film winding roll 64 Heating roll 65 Bonding roll (cooling roll)
66 Winding roll A A portion where the conductive mesh layer is formed TA A thickness B A portion where the conductive mesh layer is not formed TB B thickness

Claims (3)

(A) preparing a continuous band-shaped electromagnetic shielding sheet having at least a conductive mesh layer on one surface of the first transparent resin substrate sheet;
(B) A step of preparing a continuous band-shaped optical filter having an adhesive layer on one surface of the second transparent resin base sheet provided with an optical function;
(C) heating at least the pressure-sensitive adhesive layer of the continuous belt-shaped optical filter;
(D) While cooling at least the pressure-sensitive adhesive layer of the continuous band-shaped optical filter, the surface of the continuous band-shaped optical filter on the pressure-sensitive adhesive layer side is the surface on the conductive mesh layer side of the continuous band-shaped electromagnetic wave shielding sheet. Pasting together to obtain a continuous strip-shaped composite sheet,
(E) The manufacturing method of the composite filter which has the process of making the said continuous strip-shaped composite sheet into a sheet. The electromagnetic wave shielding sheet has a primer layer between the first transparent resin substrate sheet and the conductive mesh layer,
The thickness of the portion of the primer layer where the conductive mesh layer is formed is thicker than the thickness of the portion where the conductive mesh layer is not formed,
In the conductive mesh layer, the cross-sectional area cut by a virtual plane parallel to the surface of the first transparent resin base sheet is a decreasing function S (x) of the distance x from the first transparent resin base sheet. The method for manufacturing a composite filter according to claim 1.   The interface between the primer layer and the conductive mesh layer is interleaved and / or in the vicinity of the interface between the primer layer and the conductive mesh layer, the primer component contained in the primer layer and the conductive layer There is a region where the conductive composition constituting the conductive mesh layer is mixed and / or the primer component contained in the primer layer is present in the conductive composition constituting the conductive mesh layer. The manufacturing method of the composite filter of Claim 2.

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