JP2008147356A - Metal blackening treatment method, electromagnetic wave shielding filter, composite filter, and display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal blackening treatment method capable of easily forming a blackened layer for preventing the reflection of light emitted from the screen of a display and the incident light from the outside for improving the viewability of the display screen, and forming a thin blackened layer of superior adhesion at the base-metal layer interface. <P>SOLUTION: This metal blackening treatment method, for forming the blackened layer of an electromagnetic wave shielding filter for the display formed by laminating at least a transparent base, a copper mesh layer, and the blackened layer, comprises a process for forming the blackened layer on the surface of the copper mesh layer by bringing the laminate, including at least the transparent base and the copper mesh layer made to contact with a metal blackening treatment solution which is hydrochloric acid solution wherein tellurium is dissolved, the concentration (oxide-converted concentration) of tellurium in the hydrochloric acid solution is 0.01-0.45 wt.%, and the concentration of hydrochloric acid is 0.05-8 wt.%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is laminated on a copper mesh layer of an electromagnetic wave shielding filter that shields (shields) electromagnetic waves generated from a display such as a cathode ray tube (hereinafter also referred to as CRT) and a plasma display panel (hereinafter also referred to as PDP). The present invention relates to a metal blackening method for forming a blackening layer, an electromagnetic wave shielding filter, a composite filter, and a display including the electromagnetic wave shielding filter and the composite filter.

In recent years, with the advancement of functions and increased use of electrical and electronic equipment, electromagnetic noise interference (EMI) has increased, and electromagnetic waves are also generated in displays such as CRTs and PDPs. A PDP is a combination of a glass having a data electrode, a fluorescent layer, and a glass having a transparent electrode, and generates a large amount of electromagnetic waves, near infrared rays, and heat when activated.
Usually, an electromagnetic wave shielding sheet is provided as a front plate on the front surface of the plasma display panel in order to shield electromagnetic waves. The shielding property of electromagnetic waves generated from the front surface of the display requires a function of 30 dB or more at 30 MHz to 1 GHz. Furthermore, in order to make the display image easy to see, it is difficult to see the metal mesh part (line part) for shielding electromagnetic waves, and the mesh pattern accuracy is good and the mesh is not disturbed. ).

  A basic layer structure of the electromagnetic wave shielding filter is shown in FIG. The mesh-like conductor layer 12 is formed on the transparent substrate 11 directly or via an adhesive (adhesive) layer. When the mesh-like conductor layer includes a metal mesh layer having a metallic luster, a blackening layer is usually provided on the surface for the purpose of preventing the reflection of external light or display light and improving the visibility. .

For example, Patent Document 1 discloses a translucent electromagnetic wave shielding material characterized in that a surface layer portion of a metal layer formed in a pattern on a transparent substrate is a metal compound exhibiting a black color. According to the translucent electromagnetic wave shielding material disclosed in Patent Document 1, since the metal layer is covered with the black layer, it is possible to prevent a decrease in visibility due to the metallic luster of the metal layer.
Moreover, in patent document 2, in the shielding material which has the pattern of a metal layer on one surface of a transparent base material, it is fine on the surface at the side of the said transparent base material among the front and back both surfaces and side surfaces of the pattern of the said metal layer. And a metal oxide is formed on the other surface of the metal layer pattern, thereby blackening both sides and side surfaces of the metal layer pattern. Has been. According to the shield material disclosed in Patent Document 2, it is possible to prevent the light emitted from the display surface of the display or the incident light from the outside from being reflected, and thus the visibility of the display screen can be improved.
However, the blackening layers of Patent Documents 1 and 2 are obtained by immersing an electromagnetic wave shielding filter in a high-temperature alkaline aqueous solution and changing the composition of the surface of the metal mesh layer as a chemical conversion treatment. -Erosion (undercut) between metal layers may be a problem. In particular, in the case of bonding the substrate and the metal layer without interposing the adhesive layer, they are easily peeled off.

  Patent Document 3 discloses a translucent electromagnetic wave shielding material in which a black electroplating layer covering an electroless plating layer laminated in a pattern is laminated. The black plating layer is formed by an electrolytic plating method using an acidic black chrome plating solution and a black nickel plating solution. However, the blackened layer formed by the electrolytic plating method has a metallic luster, thus preventing reflection. The performance may be insufficient.

Patent Document 4 discloses a hydrochloric acid solution in which tellurium is dissolved, the tellurium concentration (oxide equivalent concentration) in the hydrochloric acid solution is in the range of 0.5 to 16% by weight, and the hydrochloric acid concentration is 9%. A metal blackening treatment liquid for blackening silver, copper, gold and alloys thereof characterized by being in the range of 0.5 to 36% by weight is disclosed.
The blackening treatment liquid disclosed in Patent Document 4 is suitable for the blackening treatment of jewelry metal, and is one-component, easy to operate and stable. However, when the blackening treatment liquid is used for forming the blackening treatment layer of the electromagnetic wave shielding filter, the blackening layer becomes too thick and the interface with the metal layer is liable to be peeled off. (Undercut) may be a problem. Also, the concentration of hydrochloric acid is high and the working environment is bad.

Japanese Patent Laid-Open No. 10-56290 Japanese Patent No. 3734683 Japanese Patent No. 2974655 JP 2006-233327 A

  The present invention has been made to solve the above-mentioned problems of the conventional blackening layer, and prevents the reflection of the emitted light from the display surface of the display and the incident light from the outside, thereby improving the visibility of the display screen. A metal blackening treatment method capable of forming a thin blackening layer that is easy to form a blackening layer for the purpose of improvement and has excellent adhesion at the interface between the substrate and the metal layer, and the metal black It is an object of the present invention to provide an electromagnetic wave shielding filter and a composite filter having a blackened layer formed by using the method for forming an electromagnetic wave, and a display including the electromagnetic wave shielding filter and the composite filter.

As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by treating the surface of the copper mesh layer with a metal blackening solution having a specific tellurium concentration and hydrochloric acid concentration. The present invention has been completed.
That is, the metal blackening treatment method of the present invention is a metal blackening treatment method for forming a blackening layer of an electromagnetic wave shielding filter in which at least a transparent substrate, a copper mesh layer, and a blackening layer are laminated. , A hydrochloric acid solution in which tellurium is dissolved, and the tellurium concentration (oxide equivalent concentration) in the hydrochloric acid solution is 0.01 to 0.45% by weight, and the hydrochloric acid concentration is 0.05 to 8% by weight. It includes a step of bringing a metal blackening treatment solution into contact with a laminate comprising at least a transparent substrate and a copper mesh layer to form a blackened layer on the surface of the copper mesh layer.
According to the above-described metal blackening treatment method of the present invention, the base material is compared with the conventional metal blackening treatment solution of tellurium in hydrochloric acid solution under mild conditions that the tellurium concentration and hydrochloric acid concentration are lower than those of the conventional treatment solution. -Erosion between metals is improved, and the vaporization of hydrochloric acid (or hydrogen chloride) or fog in the working atmosphere is reduced, resulting in a favorable working environment and depositing a blackened layer in a short time. be able to.
The electromagnetic wave shielding filter obtained by the metal blackening treatment method of the present invention has a thin blackening layer and high adhesion between the copper mesh layer-blackening layer and the copper mesh layer-transparent substrate. In addition, when used in front of the display, it exhibits excellent antireflection performance against external light in addition to the electromagnetic shielding function.

  The electromagnetic wave shielding filter for display according to the present invention is formed by laminating at least a transparent base material, a copper mesh layer, and a blackening layer containing tellurium chloride. The adhesion between the blackening layer and the copper mesh-transparent substrate is high, and when used in front of the display, it exhibits excellent antireflection performance against external light.

  In the electromagnetic wave shielding filter of the present invention, when the blackened layer is laminated on the surface and side surfaces of the copper mesh layer, it exhibits excellent antireflection performance against external light when used in preparation for the front surface of the display. preferable. The definition of “surface” will be described later.

The composite filter for display of the present invention includes the electromagnetic wave shielding filter for display, a near infrared absorption function, a neon light absorption function, a color tone adjustment function, an ultraviolet absorption function, an antireflection function, an antiglare function, an anti-scratch function, and an anti-scratch function. It is characterized in that it is formed by laminating one layer or two or more layers of filters having any one kind or two or more kinds of contamination functions.
Such a composite filter can be used as a display front plate to which various functions are added in addition to the antireflection performance and the electromagnetic wave shielding function.

The display of the present invention is characterized in that the electromagnetic wave shielding filter or the composite filter for display is arranged on a display surface of the display.
In addition to the electromagnetic wave shielding function, the display of the present invention has excellent antireflection performance against external light due to the blackened layer of the electromagnetic wave shielding filter or composite filter. Moreover, when the display of this invention is equipped with a composite filter, the merit by the various functional layers which the said filter has can also be enjoyed.

According to the metal blackening treatment method of the present invention, it is possible to form a blackened layer of an electromagnetic wave shielding filter formed by laminating at least a transparent base material, a copper mesh layer, and a blackened layer. Since the blackened layer can be deposited in a shorter time and under a milder condition than the processing method, the adhesion between the copper mesh layer and the blackened layer and between the copper mesh layer and the transparent substrate is high, and excellent against external light. In addition, an electromagnetic wave shielding filter for display having antireflection performance can be obtained.
Moreover, since the electromagnetic wave shielding filter for a display according to the present invention is manufactured using the metal blackening treatment method, the adhesion between the copper mesh layer-blackening layer and the copper mesh layer-transparent substrate is high, and the outside Excellent antireflection performance for light.

According to the composite filter for a display according to the present invention, one or more functional layers are laminated on the electromagnetic wave shielding filter, so that in addition to the antireflection function and the near electromagnetic wave shielding function, the front plate of the display is provided. It can be used as a display front plate to which various required functions are added.
Since the display according to the present invention includes the electromagnetic wave shielding filter or the composite filter, in addition to the electromagnetic wave shielding function, the blackening layer of the electromagnetic wave shielding filter or the composite filter provides excellent external light antireflection performance. To do. Moreover, when the display of this invention is equipped with a composite filter, the merit by the various functional layers which the said filter has can also be enjoyed.

1. Metal blackening treatment method The metal blackening treatment method of the present invention is a metal blackening treatment for forming a blackening layer of an electromagnetic wave shielding filter in which at least a transparent substrate, a copper mesh layer, and a blackening layer are sequentially laminated. This is a hydrochloric acid solution in which tellurium is dissolved, the tellurium concentration (oxide equivalent concentration) in the hydrochloric acid solution is 0.01 to 0.45% by weight, and the hydrochloric acid concentration is 0.05 to 8 A step of contacting a laminate comprising at least a transparent base material and a copper mesh layer with a metal blackening treatment solution of wt% to form a blackened layer on the surface of the copper mesh layer. And

According to the metal blackening treatment method of the present invention, since the tellurium concentration and the hydrochloric acid concentration are lower than those of the conventional treatment liquid, the blackening layer can be deposited under mild conditions as compared with the conventional metal blackening treatment liquid. it can.
The electromagnetic wave shielding filter obtained by the metal blackening treatment method of the present invention has a thin blackening layer and high adhesion between the copper mesh layer-blackening layer and the copper mesh layer-transparent substrate. Blackening, which was insufficient in the electromagnetic wave shielding filter obtained by performing conventional blackening treatment on a laminate in which a thin copper mesh layer was laminated on a transparent substrate without an adhesive layer The layer strength and the copper mesh layer-blackened interlayer and the copper mesh layer-excellent in terms of having sufficient adhesion between the transparent substrate. Further, when used in front of the display, it exhibits excellent antireflection performance in addition to the electromagnetic wave shielding function.

The metal blackening treatment liquid used in the present invention will be specifically described.
The metal blackening solution used in the present invention is a hydrochloric acid solution in which tellurium is dissolved, and it is preferable to use tellurium oxide as a source of this tellurium. Tellurium oxide is used as tellurium source in the present invention can be represented by TeO _2.
In the metal blackening solution (100% by weight) of the present invention, tellurium is an amount in the range of 0.01 to 0.45% by weight, preferably 0.05 to 0.40% by weight in terms of oxide. % Content. Since the metal blackening treatment liquid of the present invention has a tellurium concentration lower than that of the conventional treatment liquid, the deposition rate of the blackening layer is reduced, and a thin blackening layer having high adhesion between the metal-blackening layers is deposited. be able to. In the present invention, tellurium is present in the treatment liquid in a state dissolved in hydrochloric acid, has very good stability, and even when the metal blackening treatment liquid is allowed to stand for a long time, the compound is hardly precipitated. Therefore, the metal blackening treatment liquid of the present invention can be used as a one-pack type treatment agent. Furthermore, since the stability of the one-pack type metal blackening treatment liquid does not deteriorate even after being brought into contact with the treated metal, it can be used repeatedly.
When the amount of tellurium exceeds 0.45% by weight, the deposition rate of the blackened layer is too high, the blackened layer deposited on the metal surface is cracked, and the adhesion between the blackened layer and the metal is poor. If the amount is less than 0.01% by weight, the adhesion between the blackened layer and the metal is sufficient, but the deposition rate of the blackened layer is small and the processing efficiency may be inferior.
As the tellurium oxide used in the metal blackening treatment liquid of the present invention, industrially provided tellurium oxide can be used, but it is preferable to use a tellurium oxide having a high purity, and a purity of 99 to It is particularly preferred to use 100% tellurium oxide.

An aqueous hydrochloric acid solution that dissolves tellurium oxide is usually formed by blending water with 35% hydrochloric acid (hereinafter also simply referred to as hydrochloric acid). The concentration of HCl (hydrogen chloride) in the aqueous hydrochloric acid solution is in the range of 0.05 to 8% by weight, preferably 0.1 to 2% by weight, and more preferably 0.3 to 1% by weight. By using an aqueous hydrochloric acid solution having such a concentration, the tellurium oxide can be completely dissolved. Further, when the metal to be treated is a metal thin film directly laminated on a support, there is sufficient adhesion without causing erosion (undercut) between the support and the metal thin film.
Further, according to the blackening treatment liquid having the HCl concentration, the obtained blackening treatment product is excellent in antireflection performance. It was speculated that the blackening treatment liquid of the present invention had a lower surface roughness of the metal after the treatment than the conventional blackening treatment liquid having a high HCl concentration, and the antireflection performance due to the rough surface effect of the metal surface was inferior. However, the blackening layer obtained by the blackening treatment liquid of the present invention is actually superior in antireflection performance. The cause of this is not clear, but is presumed to be due to the difference in the shape and atomic arrangement of the formed blackened layer.
When HCl concentration exceeds 8 weight%, there exists a possibility that it may be inferior to the adhesiveness between a base material and a copper mesh layer, and an undercut may generate | occur | produce. In particular, in the case of a copper mesh layer in which the metal to be treated is directly laminated on the support, undercut is likely to occur. Moreover, the antireflection performance may be inferior.
Further, when the HCl concentration is less than 0.05% by weight, there is a possibility that tellurium oxide cannot be completely dissolved in the hydrochloric acid aqueous solution. As a result, the deposition rate of the blackened layer on the metal surface is reduced, and the treatment is performed. May be inefficient.

In addition to the aqueous hydrochloric acid solution as described above, any organic acid and inorganic acid may be added.
The metal blackening treatment liquid of the present invention preferably contains sulfuric acid as an inorganic acid, and the sulfuric acid concentration is preferably 90% by weight or less from the viewpoint that a blackening layer having a high black concentration can be formed.
When the sulfuric acid concentration exceeds 90% by weight, when the metal to be treated is a metal thin film directly laminated on a support, the adhesion between the support and the metal thin film is inferior, and undercutting may occur.
The sulfuric acid concentration is preferably 10 to 45% by weight, more preferably 15 to 30% by weight, because the treatment time can be shortened and the black density of the resulting blackened layer is excellent.

As the inorganic acid, nitric acid, phosphoric acid and the like can be used in addition to the sulfuric acid. As the organic acid, organic carboxylic acids such as acetic acid, formic acid, propionic acid, succinic acid, and benzoic acid, organic sulfonic acids such as methanesulfonic acid, and the like can be used. When the metal blackening treatment liquid of the present invention contains an inorganic acid and an organic acid other than the hydrochloric acid and sulfuric acid, it can be contained in an amount of about 0 to 90% by weight as necessary.
Moreover, you may add the 3rd component for improving the solubility of tellurium to the metal blackening process liquid used for this invention.

  The metal blackening solution used in the present invention is prepared by mixing hydrochloric acid and water to prepare an aqueous hydrochloric acid solution, blending tellurium oxide with the aqueous hydrochloric acid solution, and completely dissolving the tellurium oxide in the aqueous hydrochloric acid solution. be able to.

  In the metal blackening treatment method of the present invention, a laminate comprising at least a transparent substrate and a copper mesh layer is brought into contact with the metal blackening treatment liquid to form a blackened layer on the surface of the copper mesh layer. The process of carrying out is included. By the said process, the electromagnetic shielding filter by which a transparent base material, a copper mesh layer, and a blackening layer are laminated | stacked in order at least can be obtained.

FIG. 1 is a schematic cross-sectional view illustrating the basic form of a laminate comprising at least a transparent substrate and a copper mesh layer that is brought into contact with the metal blackening treatment liquid.
The laminated body 3 of FIG. 1 (A) has the structure which has the transparent base material 11 as an essential layer, and the copper mesh layer 14 was laminated | stacked on it. Although the transparent base material 11 and the copper mesh layer 14 are directly laminated, they may be laminated via other layers. For example, the laminate of FIG. 1B has a configuration in which a transparent adhesive layer 15 is interposed between the transparent base material 11 and the copper mesh layer 14 so that these layers are bonded and laminated. 1C is an example of a layer structure when an electromagnetic wave shielding filter is formed by an electrolytic plating method, and a conductive treatment layer 13 is formed on the transparent substrate 11, and copper is further formed thereon. The mesh layer 14 has a laminated structure.

Hereinafter, each layer of the laminate will be described.
(Transparent substrate)
A transparent base material is a layer used as the support body for reinforcing the copper mesh layer with weak mechanical strength. Therefore, as long as it has light transmittance as well as mechanical strength, it may be selected and used depending on the application, taking into account heat resistance, insulation, etc. as appropriate. Specific examples of the transparent substrate include, for example, plates and sheets (or films; the same applies hereinafter) made of an organic material such as a resin, and plates made of an inorganic material such as glass.

Examples of transparent resins used as plates and sheets made of the above organic materials include, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, terephthalic acid-isophthalic acid-ethylene glycol copolymer, terephthalic acid-cyclohexanedimethanol-ethylene glycol. Polyester resins such as copolymers, polyamide resins such as nylon 6, polyolefin resins such as polypropylene and polymethylpentene, acrylic resins such as polymethyl methacrylate, styrene resins such as polystyrene and styrene-acrylonitrile copolymers And cellulose resins such as triacetyl cellulose, imide resins, polycarbonate resins and the like.
In addition, these resins are used as a single or a plurality of types of mixed resins (including polymer alloys) as a resin material, and as a layer, they are used as a single layer or a laminate of two or more layers. In the case of a resin sheet, a uniaxially stretched or biaxially stretched sheet is more preferable in terms of mechanical strength.

Moreover, you may add additives, such as a ultraviolet absorber, a filler, a plasticizer, an antistatic agent, in these resins suitably as needed.
Further, as the glass of the glass plate, there are quartz glass, borosilicate glass, soda lime glass, etc. More preferably, the thermal expansion coefficient is small, the dimensional stability and the workability in high-temperature heat treatment are excellent, and the glass contains an alkali. Examples include alkali-free glass that does not contain a component, and can also be used as an electrode substrate that serves as a front substrate of a display.

The thickness of the transparent substrate is not particularly limited as long as it depends on the application. When the transparent substrate is made of a transparent resin, it is usually about 12 to 1000 μm, preferably 50 to 500 μm. On the other hand, when a transparent base material is a glass plate, about 1-5 mm is usually suitable. In any material, when the thickness is less than the above, the mechanical strength is insufficient and warping, loosening, breakage, and the like occur. When 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 base material may also be used as a front substrate, which is a component of the display main body including the front substrate and the rear substrate, but in the form using an electromagnetic wave shielding filter as a front filter disposed in front of the front substrate. The sheet is superior to the plate in terms of thinness and lightness, and the resin sheet is superior to the glass plate in that it is not broken.

  In this respect, a resin sheet is a preferable material for the transparent substrate, but among the resin sheets, in particular, polyester resin sheets such as polyethylene terephthalate and polyethylene naphthalate have transparency, heat resistance, cost, and the like. In view of this, a biaxially stretched polyethylene terephthalate sheet is more preferable. In addition, although the transparency of a transparent base material is so good that it is high, Preferably the light transmittance which becomes 80% or more by visible light transmittance | permeability is good.

(Copper mesh layer)
The copper mesh layer is composed of copper or an alloy mainly composed of copper (copper compounding ratio is 50% or more) (hereinafter, “copper” includes an alloy unless otherwise specified), and has conductivity. It is a layer that has an electromagnetic wave shielding function, and is itself opaque but has a mesh-like shape and has an opening so as to achieve both electromagnetic wave shielding performance and light transmittance. From the viewpoint of improving the electromagnetic wave shielding function, it is preferable that the conductivity is high. Therefore, the copper content is preferably high.
The total light transmittance of the copper mesh layer is usually 50% or more, more preferably 80% or more.
The copper mesh layer may be a single layer or a multilayer.

In general, the copper mesh layer is typically formed by etching a copper foil, but other layers can exhibit electromagnetic wave shielding performance and can be used in the present invention. Therefore, in the present invention, the method for forming the copper mesh layer is not particularly limited, and various copper mesh layers in conventionally known light-transmitting electromagnetic wave shielding filters can be appropriately employed. For example, a copper mesh layer formed in a mesh shape from the beginning on a transparent substrate using a printing method or a plating method, or initially a copper layer is formed on the entire surface of a transparent substrate by a plating method. After the formation, a copper mesh layer or the like formed into a mesh shape by etching or the like may be used.
For example, when the mesh shape of the copper mesh layer is formed by etching, it can be formed by patterning the copper foil laminated on the transparent base material by etching and opening the openings to form a mesh. To laminate a copper foil on a transparent substrate, the copper foil is laminated to the transparent substrate with an adhesive, or one or more of a copper layer is deposited, sputtered, plated, etc. without using a laminating adhesive It can also be laminated on a transparent substrate using the physical or chemical forming method.
The copper mesh layer by etching may be formed by laminating a single copper foil before lamination on a transparent base material into a mesh shape by etching, and then laminating the transparent copper base material with an adhesive or the like.

  In addition to the copper mesh layer, the layer having conductivity and the electromagnetic wave shielding function includes, for example, a conductive thin layer (hereinafter referred to as a conductive treatment layer) serving as a base layer for copper plating. In the present specification, these are collectively referred to as a mesh-like conductor layer.

The shape of the mesh-like conductor layer including the copper mesh layer is not particularly limited, but a square is typical as the shape of the opening. Examples of the shape of the opening include a triangle such as a regular triangle, a square such as a square, a rectangle, a rhombus and a trapezoid, a polygon such as a hexagon, a circle and an ellipse. The mesh has a plurality of openings having these shapes, and the openings are usually partitioned by a line portion having a uniform width. Usually, the openings and the openings have the same shape and the same size over the entire surface.
For example, in the case of a grid-like mesh-like conductor layer as shown in FIG. 3, the width of the line portion 104 between the openings is the line width W in terms of the opening ratio and mesh invisibility. It is preferable that it is 25 μm or less, preferably 20 μm or less. However, it is preferable to secure at least 5 μm or more for the expression of the electromagnetic wave shielding effect and prevention of breakage. The opening width is represented by (line pitch P) − (line width W). In the present invention, it is preferably 150 μm or more, preferably 200 μm or more from the viewpoint of light transmittance. However, in order to exhibit electromagnetic wave shielding properties in the MHz to GHz band, the maximum is 3000 μm or less.

The thickness of the copper mesh layer is usually about 1 to 100 μm, preferably 2 to 20 μm. If the thickness is too thin, it will be difficult to obtain sufficient electromagnetic wave 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 and the uniformity of the mesh shape will be reduced. .
The metal blackening treatment method of the present invention is applied to a conventional black body for a laminate having a thin copper mesh layer with a copper mesh layer of about 1 to 10 μm, particularly a laminate laminated without an adhesive layer. The strength of the blackened layer, and the adhesion between the copper mesh layer-blackened layer and the copper mesh layer-transparent substrate, which was insufficient in the electromagnetic wave shielding filter obtained by performing the blackening treatment, may be improved. It is particularly excellent in that it can

  Further, the bias angle of the mesh region (the angle formed between the mesh line portion and the outer periphery of the electromagnetic wave shielding filter) 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 mesh-like conductor layer may be meshed over the entire surface of the electromagnetic wave shielding filter. However, a portion requiring light transmission is used as a mesh-like mesh portion, and other portions (for example, a frame around all four sides) It may be a non-mesh part (enclosed in a shape). The non-mesh portion is a portion other than the mesh portion, and is a region where light transmittance is not required as a surface. Usually, a non-mesh part is provided on the outer periphery of the mesh part. The non-mesh part is usually used for grounding. The non-mesh part used for grounding is usually framed around all four sides. In addition, the frame-like non-mesh portion is an external image that enhances the appearance of the image seen through the mesh portion such as a display image by surrounding the image with a frame shape (for example, a black frame) to enhance the image. It can also be used as a frame. The non-mesh portion preferably exposes the conductor layer in at least a portion of the ground when it is grounded.
Although the specific size of the non-mesh part depends on how it is used, when the frame is in the shape of a ground part or outer frame, the width of the frame is about 15 to 100 mm, and in particular, it is generally 30 to 40 mm. It is.

(Other layers)
The laminate to be brought into contact with the metal blackening treatment liquid may have other layers as required in addition to the transparent base material and the copper mesh layer. For example, an adhesive layer for bonding the transparent base material and the copper mesh layer between the transparent base material and the copper mesh layer, and a conductive treatment layer as a base layer for copper plating are provided by a conventionally known material and technique. Can do.
Moreover, the blackening layer and / or the antirust layer may be previously provided by the conventionally well-known material and method in the surface at the side of the display apparatus of a copper mesh layer.

  When the metal blackening treatment liquid comes into contact with a laminate comprising at least a transparent substrate and a copper mesh layer, the following dissolution reactions (i) to (iii) and the following precipitation reaction (iv) are performed at the contact interface. It is expected that ~ (viii) has occurred.

TeO ₂ + 4HCl → Te ⁴⁺ + 4Cl ⁻ + 2H ₂ O (i)

Te ⁴⁺ + 2Cl ⁻ + 2e ⁻ → TeCl ₂ (iv)
Te ⁴⁺ + 4e ⁻ → Te (v)
Te ⁴⁺ + 4Cl ⁻ → TeCl ₄ (vi)
Cu ²⁺ + 2Cl ⁻ → CuCl ₂ (vii)
Cu ⁺ + Cl ⁻ → CuCl (viii)

The color of the compound expected to precipitate is TeCl ₂ is black, Te is silver gray to gray, TeCl ₄ is yellow, CuCl ₂ is white, and CuCl is brown yellow. From the color tone of the blackened layer, it is estimated that the blackened layer mainly contains TeCl _2, but at least one of Te, TeCl ₄ , CuCl ₂ , and CuCl is included depending on conditions. Further, in the air, compounds in which they are oxidized, that is, TeO ₂ , CuO, CuO ₂ , Cu ₂ Te, CuTe, and oxides thereof may be included.

The method for contacting the metal blackening solution with a laminate comprising at least a transparent base material and a copper mesh layer is not particularly limited. For example, the method of dipping (immersion), curtain coating, pouring, etc. Contact with the mesh layer.
The contact temperature between the blackening agent and the copper mesh layer in the present invention may be ordinary temperature, and is preferably in the range of 10 to 40 ° C. Thus, the blackening agent of the present invention does not need to be heated in particular, and can be stably blackened on the surface of the copper mesh layer by contacting with the copper mesh layer at room temperature.

Under the above temperature conditions, the contact time between the copper mesh layer and the blackening treatment agent is usually 15 minutes or less, preferably 1 second to 2 minutes, particularly preferably the contact time between the metal and the blackening treatment liquid. 5 to 30 seconds. Thus, according to the metal blackening method of the present invention, the surface of the copper mesh layer can be blackened in a very short time.
The contact temperature and the contact time are not limited to the above ranges, and can be changed according to the concentration of the metal blackening solution and the composition of the constituent elements of the copper mesh layer.

The blackening layer formed by the blackening treatment of the present invention is mainly composed of tellurium chloride (TeCl ₂ ). For details of the blackened layer, see 2. The electromagnetic wave shielding filter will be described.

2. Electromagnetic wave shielding filter The electromagnetic wave shielding filter of the present invention is an electromagnetic wave shielding filter in which at least a transparent substrate, a copper mesh layer, and a blackening layer are sequentially laminated, and the blackening layer contains tellurium chloride. Features. The electromagnetic wave shielding filter of the present invention has a thin blackening layer, high adhesion between the copper mesh layer and the blackening layer, and between the copper mesh and the transparent substrate. Excellent anti-reflection performance for light.
The manufacturing method of such an electromagnetic wave shielding filter is not particularly limited as long as the blackening layer contains tellurium chloride, but the blackening layer is formed using a metal blackening treatment method. Is preferred.

〔Layer structure〕
Hereinafter, the layer structure of the electromagnetic wave shielding filter of the present invention will be described.
First, FIG. 2 is a schematic cross-sectional view illustrating a basic form of the electromagnetic wave shielding filter according to the present invention.
The electromagnetic wave shielding filter of FIG. 2 (A) has a configuration in which a blackened layer 17 is laminated on a portion where the copper mesh layer is exposed with respect to a laminate in which the copper mesh layer 14 is laminated on the transparent substrate 11. is there. Although the transparent base material 11 and the copper mesh layer 14 are directly laminated, they may be laminated via other layers.
For example, in the electromagnetic wave shielding filter of FIG. 2B, the transparent adhesive layer 15 is interposed between the transparent base material 11 and the copper mesh layer 14 so that these layers are bonded and laminated. The figure shows a case where the copper mesh layer is formed from a copper foil, and as a result, the transparent adhesive layer 15 is present on the entire surface of the transparent substrate 11 including the opening 103 in the mesh region. .
FIG. 2C shows an example of the layer structure when an electromagnetic wave shielding filter is formed by electrolytic plating. A conductive treatment layer 13 is formed on the transparent substrate 11, and a copper mesh layer 14 is further formed thereon. And a blackening layer 17 is laminated on the exposed portion of the copper mesh.

FIG. 3 is a perspective view illustrating only the transparent substrate layer 11, the conductive treatment layer 13, and the copper mesh layer 14 in the electromagnetic wave shielding filter of FIG.
The conductive treatment layer 13 and the copper mesh layer 14 (hereinafter, both layers and other conductive layers are also simply referred to as a mesh-like conductor layer 12) are mesh-like in which the openings 103 are closely arranged. The mesh-like region 101 includes an opening 103 and a line portion 104 forming a frame. A blackened layer 17 (not shown) further laminated on the surface of the copper mesh layer 14 is integrated with the conductor layer 12 to form the mesh region 101.

  4 is an AA cross-sectional view and a BB cross-sectional view of FIG. 4A shows a cross section crossing the opening, the openings 103 and the lines 104 are alternately formed, and FIG. 4B shows a cross section longitudinally cutting the line 104, and the copper mesh layer 14 and the conductive processing layer. 13 line portions 104 are continuously formed. Note that all of the cross-sectional views of the electromagnetic wave shielding filter shown in FIG. 2 correspond to the AA cross-sectional view.

In the present invention, the “front side” and “surface” are the side on which the copper mesh layer is formed with respect to the transparent substrate as “front side” (also the side facing upward in the drawing), and the side on which the copper mesh layer is formed. The surface (also the upper surface in the drawing) that faces in the same direction is called “surface”. The “back side” and “back side” refer to the side (also the side facing the lower side of the drawing) or the side (also the lower side of the drawing) opposite to the “front side” and “front side”.
Further, when applied to a display application or the like, the surface on the observer side may be the back surface instead of the surface defined in the present invention.

  The above illustration does not limit the aspect of the electromagnetic wave shielding filter of the present invention. Any device that has substantially the same structure as the technical idea described in the claims of the present invention and that exhibits the same effect can be included in the technical scope of the present invention. .

  Hereinafter, the electromagnetic wave shielding sheet of the present invention will be described for each layer. The transparent substrate and the copper mesh layer are as described in 1. above. This is the same as described in the metal blackening method.

(Blackening layer)
When the blackening layer is used in front of the display, the surface of the copper mesh layer is formed by the metal blackening treatment method for the purpose of preventing external light from being reflected by absorbing the external light. And a layer formed on the side surface. By preventing reflection of outside light, the image contrast of the display is improved and the visibility is improved.

  In the electromagnetic wave shielding filter of the present invention, when the blackened layer is laminated on the surface and side surfaces of the copper mesh layer, it exhibits excellent antireflection performance against external light when used in preparation for the front surface of the display. preferable. According to the metal blackening method, a blackened layer can be formed not only on the surface but also on the side surface. The blackening layer is typically a general film shape, but is not necessarily limited to a continuous film, and may be a discontinuous film having a two-dimensional arrangement dispersed in an island shape.

The blackening layer laminated on the surface and side of the copper mesh layer is mainly made of tellurium chloride (TeCl ₂ ), and its color is usually black, but it is not limited to black and has sufficient antireflection function for external light. Any dark color can be used.

  A preferable black density of the blackened layer is 0.6 or more. In addition, the measurement method of black density was set to the density standard ANSIT as an observation viewing angle of 10 degrees, an observation light source D50, and an illumination type using GRETAG SPM100-11 (trade name, manufactured by Kimoto Co., Ltd.) of COLOR CONTROL SYSTEM. The specimen is measured after calibration. The total light reflectance of the blackened layer is preferably 10% or less, more preferably 5% or less. The total light reflectance is measured using a spectrocolorimeter such as a spectrophotometer CM-3600d manufactured by MINOLTA in accordance with JIS Z8722.

In addition, the blackening layer may be provided in the back surface of the copper mesh layer as needed. The blackening layer on the back surface is not limited to the blackening layer obtained by the blackening treatment method of the present invention as long as it exhibits a dark color such as black and satisfies basic physical properties such as adhesion. These blackening layers can be appropriately employed.
Therefore, as a blackening layer arbitrarily provided on the back side of the copper mesh layer, an inorganic material such as a metal, an organic material such as a black colored resin, or the like can be used. For example, as the inorganic material, a metal, an alloy, a metal It is formed as a metal layer such as an oxide or a metal compound of a metal sulfide. As a method for forming the metal layer, various conventionally known blackening methods can be appropriately employed. Especially, the blackening process by a plating method is preferable at adhesiveness, uniformity, ease, etc. As a material for the plating method, for example, a metal such as copper, cobalt, nickel, zinc, molybdenum, tin, or chromium, a metal compound, or the like is used. These are superior to the case of cadmium or the like in terms of adhesion and blackness.

(Rust prevention layer)
If there is a concern that the copper mesh layer will rust and deteriorate during manufacturing, handling, etc., and deteriorate the electromagnetic shielding performance, and if it is necessary to prevent rusting, the exposed surface of the copper mesh layer is covered with a rust prevention layer Good. The coating of the anticorrosive layer may be performed on a surface selected in consideration of the manufacturing cost or the like from one or more necessary surfaces among the front surface, the back surface, and the side surface of the mesh-like conductor layer.

  The rust preventive layer is not particularly limited as long as it is less likely to rust than the copper mesh layer to be coated thereon, such as an inorganic material such as metal, an organic material such as resin, or a combination thereof. In some cases, the blackened layer is also covered with a rust-preventing layer, so that the particles of the blackened layer can be prevented from falling off and deformed, and the blackness of the blackened layer can be increased. In this respect, it is preferable to provide on the display side before the lamination of the transparent base material and the copper mesh layer.

  A conventionally well-known thing should just be employ | adopted for a rust prevention layer suitably, for example, is a metal thru | or alloys, such as chromium, zinc, nickel, tin, copper, or the layer of a metal compound of a metal oxide. These can be formed by a known plating method or the like. Here, if an example of a preferable antirust layer is shown by points, such as a rust prevention effect and adhesiveness, the chromium compound layer obtained by carrying out a chromate process after galvanization will be mentioned. Moreover, the rust preventive layer by this chromium compound layer is a blackened layer, and a transparent adhesive layer (especially a two-component curable urethane resin-based adhesive) when the transparent base material and the mesh-like conductor layer are bonded and laminated. Excellent adhesion.

In the case of chromium, chromate (chromate) treatment or the like may be used. The chromate treatment is carried out by bringing the chromate treatment solution into contact with the treated surface. This contact is not limited to coating methods such as roll coating, curtain coating, squeeze coating, pouring (single-sided contact), and electrostatic fogging. According to the chemical method, the dipping method, etc., double-sided contact is also possible. Moreover, what is necessary is just to dry, without washing with water after a contact. In addition, an aqueous solution containing chromic acid is usually used for the chromate treatment liquid. Specifically, “Alsurf (registered trademark) 1000” (manufactured by Nippon Paint Co., Ltd.), “PM-284” (Nippon Parkerizing Co., Ltd.) A processing solution such as a company) can be used.
In the chromate treatment, galvanization before the treatment is preferable in terms of adhesion and rust prevention effect. In addition, the rust preventive layer may contain a silicon compound such as a silane coupling agent in order to improve acid resistance during etching or acid cleaning.
In addition, the thickness of a rust prevention layer is about 0.001-10 micrometers normally, Preferably it is 0.01-1 micrometer.

(Transparent adhesive layer)
In the method of preparing a mesh-like conductor layer (3) described later, a transparent adhesive layer is formed by forming a transparent substrate and a copper mesh layer (a blackened layer or a rust-preventing layer is formed on the transparent substrate side of the copper mesh layer). If it is, the blackening layer or the anticorrosive layer is interposed between the two layers, and these two layers are adhered and laminated. The transparent adhesive used for the transparent adhesive layer is not particularly limited except that it requires etching resistance against an etching solution described later, and a known adhesive may be appropriately employed.
Examples of the transparent adhesive include urethane adhesives, acrylic adhesives, epoxy adhesives, rubber adhesives, and the like.

  Specifically, polyurethane resins such as polyester urethane, acrylic urethane, polyether urethane, acrylic resin, polyester resin, polyvinyl alcohol alone or a partially saponified product thereof, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer Polyimide resin, epoxy resin, etc. can be preferably used. The transparent adhesive layer used in the present invention may be an ultraviolet curable type or a thermosetting type. In particular, an acrylic resin or a polyester resin is preferable from the viewpoints of adhesion to a transparent substrate, compatibility with a neon light absorbing pigment, and dispersibility.

  Metal foil for forming a transparent base material sheet or a mesh-like conductor layer can be bonded by a dry lamination method or the like through a transparent adhesive layer. Moreover, it is preferable that the film thickness of this adhesive bond layer is in the range of 0.5 μm to 50 μm, especially 1 μm to 20 μm. As a result, the transparent base sheet and the mesh-like conductor layer can be firmly bonded, and the transparent base sheet is affected by an etching solution such as iron oxide during the etching to form the mesh-like conductor layer. It is because it can prevent receiving.

The adhesive layer may contain one or more near infrared absorbing dyes, neon light absorbing dyes, toning dyes, and / or ultraviolet absorbers as described above. By doing so, a plurality of functions can be combined in one layer, and this can be integrated with the adhesive layer, which makes it possible to reduce the total thickness, the number of steps, and the cost of the front filter, which is preferable. . In that case, the light transmittance in the wavelength region of 800 nm to 1100 nm is 20% or less, particularly 15% or less, and the light transmittance in the wavelength region of 560 to 630 nm is preferably 30% or less, particularly preferably 25% or less. .
These adhesives may contain a known antioxidant in order to prevent discoloration due to oxidation of the surface of the copper mesh layer.

(Conductive treatment layer)
In the method of preparing a mesh-like conductor layer (4) described later, a conductive treatment is performed on the transparent substrate as described above prior to the metal electrolytic plating treatment for forming the copper mesh layer. Form. As a method for the conductive treatment, a thin film of a known conductive material may be formed. Examples of the conductive material include metals such as gold, silver, copper, iron, nickel, and chromium, or alloys of these metals. Moreover, transparent metal oxides, such as a tin oxide, ITO, and ATO, may be sufficient. The conductive treatment may be a single layer or multiple layers, and these materials are formed by a known method such as vacuum deposition, sputtering, or electroless plating to form a conductive treatment layer. The thickness of the conductive treatment layer is preferably an extremely thin layer of about 0.001 to 1 μm, as long as necessary conductivity can be obtained at the time of plating.

Hereinafter, although illustrated about the manufacturing method of the electromagnetic wave shielding filter of this invention, the aspect of a manufacturing method is not limited.
First, a transparent substrate is prepared. As a transparent base material, it can select and use from the base material mentioned above.
When the transparent base material is a resin base material, it can be handled in the form of a continuous belt-like sheet at least at the initial stage of production, such as mesh layer formation, in that the electromagnetic shielding filter can be continuously manufactured to improve productivity. Is preferred.
The transparent substrate is appropriately subjected to known easy adhesion treatment such as corona discharge treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, pre-heat treatment, dust removal treatment, vapor deposition treatment, alkali treatment, etc. May be.

Next, a mesh-like conductor layer is prepared. The method for preparing the mesh-like conductor layer is not particularly limited, and a method for laminating various mesh-like conductor layers in a conventionally known light-transmitting electromagnetic wave shielding filter can be appropriately adopted. For example, the following 5 There are two methods.
(1) A method of printing a conductive ink on a transparent base material in a pattern and copper plating on the conductive ink layer (for example, JP 2000-13088 A).
(2) A conductive ink or a photosensitive coating solution containing a chemical plating catalyst is applied to the entire surface of the transparent substrate, and the coating layer is formed into a mesh by etching using a photolithography method, and then copper plated onto the mesh. (For example, Sumitomo Osaka Cement Co., Ltd., New Materials Division, New Materials Research Laboratory, 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) After laminating a transparent base material and a copper foil with a transparent adhesive or the like, the copper foil is formed into a mesh shape by etching using a photolithography method (for example, JP-A-11-145678).
(4) A transparent substrate having a conductive layer formed on one surface of a transparent substrate and a copper layer formed as a metal plating layer thereon by electrolytic plating is prepared. The plating layer and the conductive treatment layer are formed into a mesh shape by a photolithography method (for example, Japanese Patent Application Laid-Open No. 2003-86991).
(5) A transparent base material is prepared by forming a copper thin film layer on one surface of the transparent base material by a physical thin film forming method such as vapor deposition or sputtering, and the copper thin film layer of the transparent base material is prepared by a photolithography method. A mesh shape is used (for example, JP-A-10-335883).

The copper foil used in the method (3) may have a blackened layer formed in advance on the display device side by a known method, if necessary. Moreover, you may form the said antirust layer by well-known methods, such as the method of performing a well-known chromate process after zinc plating, and forming a antirust layer with respect to both surfaces of this copper foil.
In the methods (1), (2), and (4), before the step of laminating the copper layer (foil) on the transparent substrate, the conductive treatment is performed by vapor deposition or the like on the transparent substrate, if necessary. The layers may be laminated, and a rust preventive layer made of nickel, zinc, and / or copper oxide may be laminated using a known plating method, and the blackening layer may be laminated by any blackening treatment method. Also good.

Hereinafter, in the methods (2) to (5), a process of forming a conductive layer laminated on the entire surface of the transparent substrate in a mesh shape by a photolithography method will be described.
First, a resist layer is provided in a mesh pattern on a conductor layer on a transparent substrate prepared as described above, for example, a copper layer surface on a transparent substrate, and a portion of the metal layer not covered with the resist layer is etched. After the removal, the mesh layer is formed by a so-called photolithography method in which the resist layer is removed. Note that, in that case, in addition to the conductor layer, when other layers having no conductivity are stacked, the other layers are also etched away together with the conductor layer in a region corresponding to the opening.

  Also in this step, it is preferable to process a roll-shaped laminate that is continuously wound in a band shape (referred to as winding processing or roll-to-roll processing). While the laminate is conveyed continuously or intermittently, masking, etching, and resist peeling are performed in a stretched state without looseness. When glass is used as the transparent substrate 11, it is processed one by one (referred to as single wafer processing or single wafer processing). By using existing equipment and performing many of these manufacturing processes continuously, quality can be improved, production efficiency is high, yield is high, and production can be performed at low cost.

Hereinafter, the photolithography method will be described.
First, for example, masking is performed by applying a photosensitive resist to the outermost surface on the side of the conductor layer, drying, and then performing close contact exposure with a photomask having a predetermined pattern, developing with water, performing a hardening process, Bake. Note that either a negative type or a positive type of photosensitive resist can be used. When the photosensitive resist is a negative type, a photomask mesh pattern having a transparent line part is used. When the photosensitive resist is a positive type, a photomask mesh pattern having a transparent opening is used. The exposure pattern is a desired pattern as an electromagnetic wave shielding filter, and is composed of a pattern of a minimum mesh area.

  In the winding process, the photosensitive resist is coated by dipping (immersing) resist such as casein, PVA, and gelatin onto the metal layer surface while carrying the belt-shaped laminate 2 continuously or intermittently, curtain coating, and pouring. Etc. Moreover, a dry film resist may be used instead of application | coating, and workability | operativity can be improved. In the case of a casein resist, baking is performed at 200 to 300 ° C., but the lowest possible temperature is preferable in order to prevent warping of the laminate.

  Etching is performed after masking. As the etching solution used for the etching, an aqueous solution of ferric chloride or cupric chloride that can be easily circulated is preferable in the present invention in which etching is continuously performed. The etching is basically the same as the equipment and process for manufacturing a shadow mask for a color TV cathode ray tube that etches a strip-like continuous steel material, particularly a thin plate having a thickness of 20 to 80 μm. Single-wafer processing in the case of using glass as a transparent substrate has been performed for a long time. After etching, the substrate may be dried after washing with water, stripping the resist with an alkaline solution, and washing. In this way, the transparent substrate is exposed at the mesh opening.

In the laminate of the mesh-like conductor layer and the transparent substrate thus obtained, the outer surface of the mesh-like conductor layer where the transparent substrate is not laminated is further applied to the metal blackening treatment method of the present invention. A blackening layer is formed.
From the above, the electromagnetic wave shielding filter of the present invention can be obtained.

2. Composite Filter The composite filter according to the present invention includes the display electromagnetic wave shielding filter, a near infrared absorption function, a neon light absorption function, a color tone adjustment function, an ultraviolet absorption function, an antireflection function, an antiglare function, an anti-scratch function, and It is characterized by being formed by laminating one or two or more functional filters having one or two or more types of antifouling functions.
Such a composite filter can be used as a thin front panel for an image display device to which various functions are added in addition to an electromagnetic wave shielding function and an antireflection function.
The functional filter includes an optical filter such as a near-infrared absorption filter, a neon light absorption filter, an antireflection (including antiglare) filter, and a protection filter such as an anti-scratch filter and an antifouling filter. The functional filter may be any of a sheet, a plate shape, and a coating shape, and the layer thickness and flexibility are not questioned.

Depending on the method of manufacturing the composite filter, a transparent substrate may be used as a support substrate, and a functional filter may be laminated thereon, or a certain functional filter may also function as a support substrate for another functional filter. There may be a configuration in which the functional filter and the transparent substrate are laminated on each other. A transparent adhesive layer may be provided between the functional filters or between the functional filter and the transparent substrate. Each of the transparent substrate and the transparent adhesive layer may be a single layer or multiple layers. The functional filter may be laminated on either the front surface or the back surface of the electromagnetic wave shielding filter.
As these functional filters, known composite filters may be used.

Hereinafter, each functional filter will be described in order.
[Near infrared absorption filter]
As the near-infrared absorbing filter, a commercially available film having a near-infrared absorber (for example, Toyobo Co., Ltd., trade name No. 2832) is used, or a composition containing a near-infrared absorbing dye in a binder is formed, or The composition may be applied and laminated on a transparent substrate. As a near-infrared absorbing dye, when a composite filter is applied to the front surface of a plasma display panel, it absorbs a near-infrared region caused by a xenon gas discharge emitted by the plasma display panel, that is, a wavelength region of 800 nm to 1100 nm. Is used. The near-infrared transmittance of the band is preferably 20% or less, more preferably 10% or less. At the same time, it is desirable that the near-infrared absorbing filter 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, dithiol compounds, imonium compounds, diimonium compounds, and aminium. Compounds, pyrylium compounds, cerium compounds, squarylium compounds, copper complexes, nickel complexes, dithiol metal complexes organic near infrared absorbing dyes, tin oxide, indium oxide, magnesium oxide, titanium oxide, chromium oxide Zirconium oxide, nickel oxide, aluminum oxide, zinc oxide, iron oxide, antimony oxide, lead oxide, bismuth oxide, inorganic near-infrared absorbing dyes such as lanthanum oxide, etc. can be used alone or in combination of two or more. . As the binder resin, a resin such as a polyester resin, a polyurethane resin, an acrylic resin, or an epoxy resin is used. Binder resin drying and curing methods include a drying and solidification method by drying a solvent (or dispersion medium) from a solution (or emulsion), a polymerization method using heat, ultraviolet light, electron beam energy, and 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.

[Neon light absorption filter]
The neon light absorption filter is installed to absorb neon light emitted from the plasma display panel, that is, an emission spectrum of neon atoms when the composite filter is used for a plasma display. Since the emission spectrum band of neon light has a wavelength of 550 to 640 nm, it is preferable to design the neon light absorption filter so that the spectral transmittance is 50% or less at the wavelength of 550 to 640 nm. The neon light absorption filter may be formed by dispersing a dye conventionally used as a dye having an absorption maximum in a wavelength region of at least 550 to 640 nm in a binder resin as mentioned in the near infrared absorption filter. it can. Specific examples of the dye include cyanine, oxonol, methine, subphthalocyanine or porphyrin.

[Toning filter]
The toning filter is for adjusting the color of the composite filter for display in order to improve the color purity of the light emitted from the PDP, the color reproduction range, the display color when the power is turned off, and the like. For example, a composition in which a toning pigment is dispersed in a binder resin can be formed into a film, or can be formed on a transparent substrate or other functional filter, and dried or cured as necessary. it can. As the toning dye, any known dye having a maximum absorption wavelength in the visible region of 380 to 780 nm may be used in combination according to the purpose. Known dyes that can be used as toning dyes include the dyes described in JP-A Nos. 2000-275432, 2001-188121, 2001-350013, 2002-131530, and the like. Can be preferably 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. As the binder resin, the resins mentioned in the above-mentioned near infrared absorption filter can be used.

[Ultraviolet absorption filter]
Since the ultraviolet absorption filter is provided mainly to prevent the near infrared absorption dye contained in the near infrared absorption filter from being decomposed by external light (ultraviolet rays), it is laminated on the viewer side from the near infrared absorption filter. The ultraviolet absorbing filter 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 above-mentioned near infrared absorption filter can be used.

[Antireflection filter]
The antireflection (AR) filter is a layer that plays a role of reducing the reflectance when external light (for example, a fluorescent lamp, natural light, etc.) is reflected on the surface of the optical laminate. The antireflection filter generally has a multilayer structure in which a plurality of low refractive index layers, high refractive index layers, and / or medium refractive index layers are formed. For example, the antireflective filter includes a low refractive index layer and a high refractive index layer. The structure which laminated | stacked alternately is mentioned. Each of these layers can be formed by a dry method such as vapor deposition or sputtering, or by using a wet method such as coating.
For the low refractive index layer, materials described in the description of the low refractive index layer and low refractive index agent of the antiglare filter described later are used, and for the high refractive index layer and medium refractive index layer, the antiglare filter described later is used. The materials mentioned in the description of the high refractive index agent / medium refractive index agent are used.

[Anti-glare filter]
The anti-glare (AG) filter is usually provided on the outermost surface of the composite filter on the viewer side, and it reflects strong light by specular reflection of external light incident on the filter (also referred to as regular reflection; both names are appropriately used hereinafter). It is a layer that exhibits anti-glare properties by preventing reflection and weakly reflecting (diffuse reflection) in all directions. Anti-glare filter has fine irregularities that irregularly reflect external light on the surface of the layer by forming a coating using an inorganic filler such as silica in a resin binder, or by shaping using a shaping sheet or shaping plate. It can be formed as a layer provided. As the resin for the resin binder, 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 below because surface strength is desired as the surface layer.

[Abrasion resistant filter]
Examples of the anti-scratch filter (hard coat layer) include polyfunctional (meth) acrylate prepolymers such as polyester (meth) acrylate, urethane (meth) acrylate, and epoxy (meth) acrylate, or trimethylolpropane tri (meth). An ionization compound containing trifunctional or higher polyfunctional (meth) acrylate monomers such as acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc., alone or in combination of two or more of these. It can be formed as a coating film using a radiation curable resin. Here, (meth) acrylate is a composite notation meaning acrylate or methacrylate.

[Anti-fouling filter]
As specific examples of the antifouling agent, additives that exhibit water repellency, oil repellency, and fingerprint wiping are effective. More specific examples include fluorine compounds, silicon compounds, or mixed compounds thereof. More specifically, silane coupling agents having a fluoroalkyl group, such as 2-perfluorooctylethyltriaminosilane, and the like can be mentioned, and those having an amino group can be preferably used.

[Other layers]
[Transparent substrate]
The transparent base material mentioned in description of the transparent base material of the said metal blackening process method can be used suitably.

[Adhesive layer]
An adhesive layer (or a pressure-sensitive adhesive layer) may be used to bond the above layers. The type of material and the like of the adhesive layer are not particularly limited as long as the layers to be bonded can be bonded to each other.
However, when the mesh-like conductor layer is an embodiment in which the metal foil and the transparent base material are bonded to each other through the adhesive layer, and then the metal foil is formed into a mesh shape by etching, the adhesive layer has an etching resistance. It is preferable to have.

  Specifically, polyurethane resins such as polyester urethane, acrylic urethane, polyether urethane, acrylic resin, polyester resin, polyvinyl alcohol alone or a partially saponified product thereof, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer Polyimide resin, epoxy resin, etc. can be preferably used. The adhesive layer (or pressure-sensitive adhesive layer) used in the present invention may be an ultraviolet curable type or a thermosetting type. In particular, an acrylic resin or a polyester resin is preferable from the viewpoints of adhesion to a transparent substrate, compatibility with a neon light absorbing pigment, and dispersibility.

  Metal foil for forming a transparent base material sheet or a mesh-like conductor layer can be bonded by a dry lamination method or the like through an adhesive layer. Moreover, it is preferable that the film thickness of this adhesive bond layer is in the range of 0.5 μm to 50 μm, especially 1 μm to 20 μm. As a result, the transparent base sheet and the mesh-like conductor layer can be firmly bonded, and the transparent base sheet is affected by an etching solution such as iron oxide during the etching to form the mesh-like conductor layer. It is because it can prevent receiving.

  The adhesive layer may contain one or more neon light absorbing dyes, color correcting dyes, and / or ultraviolet absorbers as described above. By doing so, a plurality of functions can be combined in one layer, and this can be integrated with the adhesive layer, which makes it possible to reduce the total thickness, the number of steps, and the cost of the front filter, which is preferable. .

  In addition to the transparent base material and the adhesive layer, in a mode in which the composite filter is directly bonded to the entire display surface, a known impact resistant layer is laminated on the display device side of the composite filter from the viewpoint of enhancing the impact resistance effect. May be. The impact resistant layer may contain one or more near infrared absorbing dyes, neon light absorbing dyes, and / or color correcting dyes as described above.

[Planarization layer]
In the method (3) for preparing the mesh-shaped conductor layer, the adhesive of the mesh opening of the electromagnetic wave shielding filter, that is, the surface of the transparent adhesive for bonding and laminating the transparent base material and the mesh-shaped conductor layer is used. In order to fill the roughness and / or to make transparent by preventing air bubbles from being mixed, the mesh opening is filled with a transparent resin called a flattening resin as necessary, and coated as a flattening layer. Also good.
The flattening layer may be any material that has high transparency, good adhesion to the conductive layer of the mesh, and good adhesion to the adhesive layered on the flattening layer. However, if there are protrusions, dents, or unevenness on the surface of the flattening layer, moire, interference unevenness, and Newton rings may occur when installed on the front surface of the display. In order to prevent such problems, as a preferable method, after applying a heat or ultraviolet curable resin as a resin, a substrate having excellent planarity and having a peelable property is laminated, and the applied resin is cured with heat or ultraviolet light to be peeled off. A method of peeling and removing the conductive substrate. As for the surface of the planarization layer, the surface of the planar substrate is transferred to form a smooth surface. The resin used for the flattening layer is not particularly limited, and various natural or synthetic resins, heat or ionizing radiation curable resins, etc. can be applied. From the viewpoint of durability, applicability, ease of flattening, flatness, etc. Acrylic ultraviolet curable resins are preferred.

[Shock resistant layer]
Further, in the case of a composite filter for use in direct bonding to the entire display surface, an impact resistant layer may be provided on the display device side surface of the composite filter from the viewpoint of enhancing the impact resistance effect. As the impact resistant layer, acrylic resin, rubber resin, silicone resin, vinyl resin, urethane resin, epoxy resin, polyester resin, and the like can be applied. Among these resins, acrylic resin or urethane resin is preferable. For example, what formed the 100-200-micrometer-thick adhesive layer using the adhesive used for the said adhesive bond layer can be used suitably.
The impact resistant layer may contain one or more near infrared absorbing dyes, neon light absorbing dyes, and / or toning dyes as described above.

3. Image display device An image display device according to the present invention is characterized in that the electromagnetic wave shielding filter for display or the composite filter for display is arranged on a display surface of a display.
In such an image display device, due to the action of the optical absorption layer of the electromagnetic wave shielding filter or the composite filter, the near-infrared emission generated from the main body of the image display device even under long-term use, particularly in a high-temperature and high-humidity environment. Is shielded. Moreover, when a composite filter is provided, the merit by the various functional layers which the said filter has can also be enjoyed.
Examples of the image display device include conventionally known displays such as CRT and PDP.

Hereinafter, the present invention will be specifically described with reference to examples. These descriptions do not limit the present invention. In the examples, parts represent parts by weight unless otherwise specified.
<Example 1>
The electromagnetic wave shielding filter having the layer structure shown in FIG.
First, as a transparent base material 11, a 10-μm thick electrolytic copper foil is bonded to a front surface of a continuous strip-shaped uncolored transparent biaxially stretched polyethylene terephthalate film (thickness: 100 μm). Dry lamination was performed through the agent layer 15 to prepare a continuous belt-like copper-clad laminated sheet.

Next, the copper foil of the copper-clad laminate sheet was processed into a mesh shape by etching using a photolithography method, and a mesh-like conductor layer composed of the copper mesh layer 14 was formed on the transparent substrate 11. A mesh laminated sheet was prepared. Specifically, a production line for a color TV shadow mask was used to perform masking to etching in a continuous band (winding).
First, a casein-based photosensitive negative resist was applied to the entire surface of the metal layer (copper foil) of the copper-clad laminate sheet by a dipping method. Conveyed intermittently to the next station, the opening is square, the line width is 10 μm, the line interval (pitch) is 300 μm, the bias angle is 49 degrees, and the outer periphery of the mesh is 15 mm wide. Using a negative pattern plate having a thickness, exposure was performed by irradiating with ultraviolet rays from a mercury lamp. While carrying the station one after another, it was developed with water, hardened, and baked at 100 ° C. Further, it was transported to the next station, and etching was carried out by spraying with a spray method using a ferric chloride solution of 50 ° C. and 42 ° Baume as an etching solution to form an opening. While transporting the stations one after another, washing was performed with water, the resist was peeled off, washed, and further dried at 60 ° C. to form a mesh, whereby a laminate 3 of the copper mesh layer 14 and the transparent substrate 11 was obtained.

Next, an aqueous solution of 0.25% by weight of tellurium dioxide (0.2% by weight of tellurium concentration), 0.45% by weight of hydrochloric acid, and 20% by weight of sulfuric acid is used as the metal blackening treatment solution, and the mesh lamination is performed on the treatment solution. The sheet was immersed for 30 seconds at a treatment temperature of 25 ° C., and a blackening layer 17 containing tellurium chloride (TeCl ₂ ) was formed on the exposed portion of copper.
Then, the electromagnetic wave shielding filter 1 was obtained through the water washing and the drying process.
<Example 2>
The composite filter 2 having the layer configuration shown in FIG.
First, an antireflection film (Dai Nippon Printing Co., Ltd., trade name “VB2”) was prepared.
Next, the antireflection film 18 is dry-laminated to the blackening layer side 17 of the electromagnetic wave shielding filter 1 obtained in Example 1 through a two-component curable urethane resin adhesive layer 19 to form a composite. Filter 2 was obtained.

<Comparative Example 1>
The electromagnetic wave shielding filter 1 having the layer configuration shown in FIG.
First, a continuous belt-like copper-clad laminated sheet was produced in the same manner as in Example 1, and then a mesh laminated sheet was produced.
Subsequently, the blackening layer 17 was formed in the part which copper exposed by the following processes.
First, as a blackening treatment plating bath, it is immersed in a mixed aqueous solution of nickel ammonium sulfate aqueous solution, zinc sulfate aqueous solution and sodium thiosulfate aqueous solution, and electroplating is performed at 0.2 A / dm ² and 30 ° C. for 5 minutes. Then, a blackening layer made of a nickel-zinc alloy was coated on a portion where copper was exposed. The thickness of the blackened layer measured on the mesh cut surface by magnified observation with a scanning electron microscope (manufactured by Hitachi High-Tech, product name “S-5000H”) was 0.2 μm.
Then, the electromagnetic wave shielding filter 1 was obtained through water washing, 50 degreeC hot water washing, and a drying process.

<Comparative example 2>
The composite filter 2 having the layer configuration shown in FIG.
First, the same antireflection film 18 as in Example 2 was prepared.
Next, the antireflection film 18 is dry-laminated to the blackening layer 17 side of the electromagnetic wave shielding filter 1 obtained in Comparative Example 1 via a two-component curable urethane resin adhesive layer 19 to form a composite. Filter 2 was obtained.

[Performance evaluation method]
The following points were evaluated with respect to the above examples and comparative examples.
(1) Reflection characteristics of the blackened layer The total light reflectance (%) measured in accordance with JIS Z8722 on the blackened treated surface is set to a spectrocolorimeter (manufactured by MINOLTA, CM-3600d) in the reflection mode. The light source is the standard light D65 and the field of view of 2 °, and the detector measures the (integrated) intensity of the total reflection light, which is the sum of both diffuse reflection light and specular reflection light. The Y value (Y of tristimulus values XYZ) was measured.
The total light reflectivity is preferably small. In particular, when the total light reflectivity is less than 10%, it is determined that the antireflection performance of the electromagnetic wave shielding filter and the composite filter is sufficient.

(2) Adhesive evaluation The blackened layer forming surface of the frame portion at the periphery of the electromagnetic wave shielding filter 1 is cut with a cutter knife to form a grid pattern (a total of 100 squares of 10 vertical × 10 horizontal) A scratch that reaches the middle of the copper foil is made. A cellophane adhesive tape (manufactured by Nichiban Co., Ltd., trade name “Cellotape” (registered trademark), width 24 mm) is stuck on the entire surface of the wound so that the adhesive layer side is the scratched surface. Thereafter, the cellophane adhesive tape is peeled off. The case where the number of cells peeled from the electromagnetic shielding filter side and attached to the cellophane adhesive tape side is 0 is passed, and the case where it is 1 or more is rejected.

<Result>
The electromagnetic wave shielding filter obtained in Example 1 had a total light reflectance of 9%, and was judged to have sufficient performance. On the other hand, the electromagnetic wave shielding filter obtained in Comparative Example 1 had a total light reflectance of 15%, and was judged to be insufficient in performance.
Further, the composite filter obtained in Example 2 had a sufficient performance with a total light reflectance of 4%. On the other hand, the composite filter obtained in Comparative Example 2 had an insufficient performance with a total light reflectance of 10%.
According to the blackening treatment of the present invention, it is possible to form an electromagnetic wave shielding filter and a composite filter that do not require electrolytic treatment and have a low reflectance in a short time.
In the electromagnetic wave shielding filter of Example 1, the adhesion of the blackened layer was acceptable. On the other hand, in Comparative Example 1, the blackened layer peeled off on the side close to the end of the frame portion, and the adhesion of the blackened layer was unacceptable.

It is sectional drawing of the typical example of the laminated body of the transparent base material obtained in the manufacture intermediate stage of the electromagnetic wave shielding filter which concerns on this invention, and a copper mesh layer. It is sectional drawing of the typical example of the electromagnetic wave shielding filter which concerns on this invention. It is a perspective view of an example (Drawing 1 (C)) of an electromagnetic wave shielding filter concerning the present invention. It is sectional drawing of an example (FIG. 3) of the electromagnetic wave shielding filter which concerns on this invention. It is sectional drawing of the Example of the electromagnetic wave shielding filter which concerns on this invention, and the composite filter for a display. It is sectional drawing of an example of the fundamental layer structure of an electromagnetic wave shielding filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electromagnetic wave shielding filter 2 Composite filter 3 Laminated body 11 Transparent base material 12 Mesh-like conductor layer (metal mesh layer)
DESCRIPTION OF SYMBOLS 13 Conductive treatment layer 14 Copper mesh layer 15 Adhesive layer 17 Blackening layer 18 Antireflection film 19 Adhesive layer 101 Mesh area 103 Opening part 104 Line part

Claims (6)

A metal blackening treatment method for forming a blackening layer of an electromagnetic wave shielding filter for a display in which at least a transparent substrate, a copper mesh layer, and a blackening layer are laminated,
A hydrochloric acid solution in which tellurium is dissolved, a tellurium concentration (oxide equivalent concentration) in the hydrochloric acid solution of 0.01 to 0.45 wt%, and a hydrochloric acid concentration of 0.05 to 8 wt% A metal blackening treatment method comprising a step of bringing a laminate comprising at least a transparent substrate and a copper mesh layer into contact with the blackening treatment liquid to form a blackening layer on the surface of the copper mesh layer.   The metal blackening treatment solution according to claim 1, wherein the metal blackening treatment solution contains sulfuric acid and the sulfuric acid concentration is 90% by weight or less.   An electromagnetic wave shielding filter for a display comprising a black base layer comprising at least a transparent substrate, a copper mesh layer, and tellurium chloride.   The electromagnetic wave shielding filter according to claim 3, wherein the blackening layer is laminated on a surface and a side surface of a copper mesh layer.   The electromagnetic wave shielding filter according to any one of claims 2 to 4, and a near-infrared absorption function, a neon light absorption function, a color tone adjustment function, an ultraviolet absorption function, an antireflection function, an antiglare function, an anti-scratch function, and an antifouling function A composite filter for display, which is formed by laminating one or two or more layers of filters having one or two or more functions.   A display comprising the electromagnetic wave shielding filter according to claim 2 or the display composite filter according to claim 5 arranged on a display surface of the display.

Images