JP2011154211A - Composite filter for front of image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device in which appearance property of a composite filter is excellent even in a non-illuminated state of the image display device. <P>SOLUTION: The composite filter for the front of the image display device is made by arranging, in an observer's view, an external light reflection preventing layer on the outermost surface and an electromagnetic wave-shielding material layer on the rearmost surface and by laminating, in the middle, at least a pigment-containing layer and a microlouver layer in an appropriate order and the microlouver layer and the electromagnetic wave-shielding material layer, in an appropriate direction. The electromagnetic wave-shielding material layer includes: a transparent base material; a primer layer formed on the transparent base material; and a conductor pattern layer made of a conductor composition formed on the primer layer with a predetermined pattern. The portion where the conductor pattern layer is formed in the primer layer is thicker than the portion where the conductor pattern layer is not formed. The conductor composition contains conductor particles and a binder resin. The distribution of the conductor particles in the conductor pattern layer shows that the distribution in the vicinity of the primer layer is relatively non-dense and the distribution in the vicinity of the tip of the conductor pattern is dense. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a composite filter for a front surface of an image display device disposed on the front surface of an image display device such as a plasma display panel (hereinafter simply referred to as PDP).

In recent years, for example, large-sized image display devices such as plasma display panels (hereinafter sometimes referred to as “PDP”), liquid crystal display devices (LCD), cathode ray tube display devices (CRT), and electroluminescent display devices (ELD). As demands for further downsizing and thinning increase, PDPs are rapidly growing as a display medium that can cope with these demands. However, since PDP uses an inert gas discharge of xenon or helium, it emits near infrared rays having a wavelength of 800 to 1000 nm. Such near infrared rays may cause malfunction of cordless telephones, infrared remote controllers, and the like. Further, there has been a problem that the color purity is lowered due to orange light emission (Ne light) of the Ne component contained in the inert gas.
Further, the PDP has a problem in that the contrast is insufficient and the image quality is deteriorated under a bright external condition, that is, in a bright room condition.
Furthermore, although PDP can provide high-luminance display characteristics, it has been suggested that PDP emits strong electromagnetic waves in the kHz to GHz band, and has an obstacle to various instruments.

  In order to solve such problems, there is an increasing demand for a front filter capable of suppressing the emission of electromagnetic waves, near infrared rays, and Ne light as described above, and improving the contrast in a bright room. As a layer for improving the contrast, a PDP front filter having a multilayer structure having an external light shielding layer having a trapezoidal black matrix in a resin layer has been developed. Patent Document 1 proposes a composite filter for PDP in which a microlouver as an external light shielding layer, a dye filter, and an electromagnetic wave shielding filter made of a mesh printed with conductive ink are laminated.

  On the other hand, various electromagnetic shielding materials have been studied so far. For example, in Patent Document 2, a conductive ink composition is directly intaglio-printed on a transparent substrate with a mesh pattern, and the mesh pattern on the transparent substrate is applied. An electromagnetic shielding material obtained by electroplating a metal layer has been proposed.

JP 2007-272161 A Japanese Patent Laid-Open No. 11-174174 WO2008 / 149969 pamphlet

  However, since the near-infrared absorption and neon light absorption layer is configured as an independent layer in the front filter for PDP described in Patent Document 1, the layer configuration of the front filter is complicated and there is a limit to the reduction in manufacturing cost. there were.

  On the other hand, since the electromagnetic wave shielding material described in Patent Document 2 is a system in which a conductive ink composition is directly transferred from an intaglio to a transparent substrate, there is no problem of pattern distortion due to a blanket cylinder peculiar to offset printing, and silk screen Compared with printing, a fine pattern can be formed. However, when applied to an electromagnetic wave shielding material, it is necessary to transfer (also referred to as transfer) an ink having poor fluidity such as a conductor ink at a high coating amount. Therefore, as a new problem that arises, when transferring the conductive ink, an untransferred portion may occur, or a transfer defect having poor adhesion may occur.

  Generally, most of the low-flowing and high-viscosity conductive ink filled in fine intaglio depressions remains in the depressions in the normal intaglio printing system, so the transfer rate of the conductor ink [= (transfer from depression Ink volume / plate recess volume) x 100%, or if it is assumed that the change in line width between the printed material and the plate is negligible (thickness of ink transferred from recess / depth of plate recess) X is simply estimated by the equation of 100%], which is low, and the maximum is about 20%. Therefore, it has been difficult to form a pattern having a sufficient thickness and sufficient electric conductivity, and it has been difficult to obtain sufficient electromagnetic wave shielding properties.

  Therefore, the present applicant transfers a conductive material composition onto a transparent substrate by intaglio printing, and in an electromagnetic wave shielding material formed with a pattern having a conductive material, a pattern based on a transfer failure of the conductive material composition. Patent Document 3 proposes an electromagnetic wave shielding material that does not cause defects such as disconnection, shape failure, insufficient transition rate, and low adhesion. In the invention described in Patent Document 3, the primer layer 2 that can maintain fluidity until the dent 6 of the conductor ink composition 15 shown in FIG. 8 (A) is cured as shown in FIG. 8 (B). The pressure-sensitive adhesive layer is bonded to the transparent base material 1 so that the primer layer 2 and the conductor ink in the recess 6 are closely adhered to each other without a gap, the primer layer is cured, and the transparent base material is peeled off from the plate surface. The conductor ink composition in the recess 64 is transferred onto the cured primer layer 2.

However, in this method, it has been found that the following problem to be solved still remains. That is, when the line width of the conductor pattern layer (conductor pattern layer) made of the conductor composition including the conductor particles and the binder resin is reduced as described above;
(1) Generally, the electrical resistance R of an object is proportional to its length L and volume resistivity ρ, and inversely proportional to its cross-sectional area S. That is, R = ρL / S. Therefore, if the conductor composition is the same (constant ρ), the plan view pattern is the same (constant L), and the thickness is also the same, the cross-sectional area decreases in proportion to the decrease in line width, and the conductive pattern portion The electrical resistance increases. Along with this, the surface resistivity as a shielding member, which is an index of electromagnetic wave shielding properties, also increases.
(2) When the print thickness is constant, the pattern line width becomes narrower, and when the line width and the conductor particle diameter approach each other, even if the conductor particle has the same particle diameter and particle shape, the unit of the fine line pattern In the cross-sectional area, the ratio of the total area of the portion where the conductor particles are in contact with each other decreases. As a result, compared to the geometrical cross-sectional area S _GEO, the effective total cross-sectional area S _AV conductor particles that can be a real current path (s) is reduced (S _AV <S _GEO), an electrical conductive pattern portion Since the resistance R becomes higher than the influence of the geometric factor (cross-sectional area S) due to the reduction in the line width, the surface resistivity of the electromagnetic wave shielding material also rises to a value simply calculated from the line width. As a result, the electromagnetic wave shielding performance decreases.
Of course, if a low volume resistivity metal layer is formed on the conductor pattern layer by electrolytic plating or the like, this increase in electrical resistance can be offset. However, in this case, the number of processes and material costs increase and the yield decreases.
Also, due to the required reduction in electrical resistance, increasing the amount of added conductor particles does not necessarily reduce the electrical resistance. Increasing the added amount of conductor particles increases the material cost and inevitably increases the price. In particular, when the added amount of the conductive particles is large, there is a problem to be solved such as a problem that the printability of the ink is lowered, and problems such as disconnection, pattern formation failure, and transfer rate decrease occur.

[Problem 2]
In addition, since the conductive particles generally have a high visible light reflectance, the conductive composition has a high visible light reflectance. In particular, metal particles tend to have this tendency. In particular, in the case of scaly conductor particles that are usually employed to reduce resistance, a surface close to a mirror surface is formed on the surface of the conductor pattern when viewed globally. Therefore, such reflection becomes close to specular reflection. High visible light reflectivity, especially when there are many specular reflection components, the surface of the conductor pattern (both on the side of the transparent substrate and on the side opposite to the transparent substrate) from external light such as electric light, sunlight, or display device This causes the problem that the image light is reflected and the screen is whitened or the image contrast is lowered.
Of course, if conductor particles having low visible light reflectance such as graphite are used, such whitening of the screen and reduction of contrast due to the conductor pattern can be prevented. However, in that case, since the volume resistivity of graphite is higher than that of metal such as silver, electromagnetic wave shielding is inferior when the same conductive pattern is designed. This is less likely to be a problem when the line width is wide, but when the conductor pattern is thinned, the electromagnetic shielding performance is reduced due to the increase in electrical resistance due to geometric factors as described above. There arises a problem that leads to shortage. Furthermore, carbon particles such as graphite increase the structural viscosity of the conductor composition and decrease the fluidity in many cases. Therefore, the reproducibility of fine line patterns tends to be poor and the transition rate tends to decrease. Become.

  Further, the composite filter for the front surface of the image display device is provided with at least an antireflection layer for improving the contrast of the image display device and preventing reflection of a light source such as a surrounding fluorescent lamp, but the antireflection layer itself, Or due to the reflection from other functional layers combined, the color on the appearance of the composite filter, especially when the panel is not lit, does not match the surrounding environment and the taste of the viewer. It was.

The present invention has been made in view of the above problems, and is a composite filter for a front surface of an image display device having an antireflection function, a near-infrared / neon light absorption function, a contrast improvement function, and an electromagnetic wave shielding function. An object of the present invention is to provide a composite filter having excellent appearance characteristics when the image display device is not lit.
The present invention
(1) When viewed from the observer side, an external light antireflection layer is disposed on the outermost surface, an electromagnetic wave shielding material layer is disposed on the outermost surface, and at least a dye-containing layer and a microlouver layer are disposed in the middle of the microlouver. A composite filter for a front surface of an image display device in which a layer and an electromagnetic wave shielding layer are laminated in an appropriate direction,
(I) The external light antireflection layer comprises an antireflection layer or an antiglare layer comprising a low refractive index layer,
(Ii) The dye-containing layer is a dye having absorption in the near infrared region, a dye having an absorption region in the neon light region, a toning dye having an absorption region in the visible light region other than the neon light region, and absorbing in the ultraviolet region. Comprising at least one light absorbing dye selected from the group consisting of dyes having a region and a resin binder,
(Iii) The microlouver layer has a trapezoidal shape in which a linear cross-sectional shape orthogonal to the extension direction is arranged in parallel on the one surface of the transparent substrate along the in-plane direction of the transparent substrate. A substantially trapezoidal dark color part, and a translucent region between the adjacent dark color parts,
(Iv) The electromagnetic wave shielding material layer includes a transparent substrate, a primer layer formed on the transparent substrate, and a conductor pattern layer formed of a conductor composition formed in a predetermined pattern on the primer layer. The portion of the primer layer where the conductor pattern layer is formed is thicker than the portion where the conductor pattern layer is not formed, and the conductor composition is a conductor. Particles and a binder resin, and the distribution of the conductive particles in the conductive pattern layer is relatively sparse in the vicinity of the primer layer and close to the top of the conductive pattern. is there,
A composite filter for the front surface of the image display device, and (2) the composite filter described in (1) above is disposed on the front surface of the main body of the image display device.
An image display device characterized by that,
Is to provide.

Since the composite filter for the front surface of the image display device of the present invention has high visible transmittance, low reflectance, and the reflection color of the filter, that is, the chromaticity coordinates of the reflected light, is in a certain range,
It has excellent appearance characteristics, and the contrast does not decrease even when an image display device is used in a place where external light is incident, and the brightness and image quality of the image do not decrease. It is possible to prevent light and electromagnetic waves from being emitted to the viewer side.
Further, since the chromaticity coordinates of the reflected light change by changing the order of the constituent filters and / or the direction of the microlouver as the contrast improving layer, the hue as seen from the surface (antireflection layer) side of the composite filter The brightness can be appropriately selected according to the application, the demands of consumers and designers, and the performance.

  The electromagnetic wave shielding material layer used in the composite filter for the front surface of the image display device of the present invention is such that the conductive composition constituting the conductive pattern layer includes conductive particles and a binder resin, and the distribution of the conductive particles is relatively Specifically, the distribution is sparse in the vicinity of the primer layer and is dense in the vicinity of the top of the conductor pattern. For this reason, the conductor pattern is thinned, and in a geometrical factor (S = small in R = ρL / S), even in an environment of high electrical resistance, a limited amount of the conductor particles are added to the conductive pattern. The density in the vicinity of the top portion of the body pattern is kept high, and the electrical contact between the conductor particles is ensured here in a concentrated manner. At the same time, interfacial peeling and dropping near the primer layer are suppressed, and high adhesion is ensured. Therefore, even when the line width of the pattern is miniaturized, there is an effect that both high electromagnetic shielding properties, mechanical strength, and high resolution due to high transparency can be achieved.

  In addition, since the distribution of the conductive particles is sparse at the interface on the primer layer side of the conductive pattern layer, the specular reflectance of light here is reduced. For this reason, when the surface of the conductor particles having a sparse distribution is directed to the external light side (image observer side), whitening of the image and deterioration of contrast due to external light can be prevented. On the other hand, in the case where the surface side where the distribution of the conductive particles is sparse is directed to the display device side, whitening of the image and reduction in contrast due to reflection of image light on the screen can be prevented.

  In the composite filter for the front surface of the image display device, the conductor particles may be configured to have a polyhedral shape, a spherical shape, or a spheroid shape, or the conductor particles may have a relatively large particle diameter. It is configured to consist of a mixture of particles and small particle diameters, or the conductor particles are composed of particles having an average particle diameter of 1 μm or less, or a plurality of conductor particles are partially fused. Or the length of a series (path) in which a plurality of conductor particles are partially fused has at least one path exceeding 1/2 of the conductor pattern layer width, or the conductor pattern When the configuration is selected such that the line width of the layer is 30 μm or less and the surface resistivity of the conductor pattern layer is 0.8 Ω / □ or less, the above effects can be further achieved.

  Further, in the above composite filter for the front surface of the image display device, when the configuration is further selected so that a metal layer is further formed on the surface of the conductor pattern layer, the electrical resistance of the pattern is further increased. It also has an effect that it can be applied to applications that require high-performance electromagnetic shielding properties that are difficult to express with only the various configurations described above.

  In the composite filter for the front surface of the image display device, the thickness of the portion of the primer layer where the conductor pattern layer is formed is larger than the thickness of the portion where the convex mesh pattern layer is not formed. In addition, the interface between the primer layer and the conductor pattern layer in the convex mesh pattern layer forming part is (a) a cross-sectional configuration in which the interface between the primer layer and the conductor pattern layer is in a non-linear manner, (b) A cross-sectional form having a layer in which a component constituting the primer layer and a component constituting the conductor pattern layer are mixed, and (c) contained in the primer layer in the conductor composition constituting the conductor pattern layer When the cross-sectional form in which the component to be present is selected, the adhesion between the primer layer and the conductor composition layer is good. Is good, there is no transition defect, pattern reproducibility is good, and when the conductor composition is transferred from the intaglio, the surroundings of the conductor composition are prevented from being scattered, and the appearance of the opening is poor and light transmission is prevented. Prevent rate drop. As a result, there is also an effect that good electromagnetic wave shielding properties can be obtained.

  In addition, the image display device of the present invention has the composite filter having the above-described characteristics disposed on the front surface, so that it exhibits a predetermined reflected color even when not lit, and has excellent overall appearance characteristics. The conventional problem that the color of the panel does not match the surrounding environment can be solved.

It is typical sectional drawing which shows an example of the layer structure of the composite filter for image display apparatus front surfaces of this invention. It is typical sectional drawing which shows the optical filter layer of the composite filter for image display apparatus front surfaces of this invention. It is a typical top view of the electromagnetic wave shielding material layer which comprises the composite filter of this invention. FIG. 4 is an enlarged view of an A-A ′ cross section in FIG. 3. It is typical sectional drawing which expands and shows a part of FIG. It is process drawing which shows an example of the manufacturing method of the electromagnetic wave shielding material layer of the composite filter of invention. It is a schematic block diagram of the apparatus which manufactures the electromagnetic wave shielding material layer used for the composite filter of this invention. In manufacturing the electromagnetic wave shielding material layer used for the composite filter of this invention, it fills with the primer layer in the dent of the conductor material composition in a recessed part, and is a schematic diagram which shows the form which the conductor material composition transfers. In the electromagnetic wave shielding material layer used in the composite filter of the present invention, (A) a schematic diagram of the state of the conductor particles before the electrical resistance reduction process is performed on the conductor pattern layer, and (B) the conductor pattern layer It is a schematic diagram of the state of the conductor particle after performing an electrical resistance reduction process. It is a cross-sectional SEM photograph of the conductor pattern of Example 1 in the electromagnetic wave shielding material layer used for the composite filter of the present invention. It is (A) typical expanded sectional view and (B) top view which show an example of the micro louver which comprises the composite filter of this invention. (A) Schematic diagram showing the layer configuration of the composite filter of Example 1, (B) Schematic diagram showing the layer configuration of the composite filter of Example 2, (C) Schematic diagram showing the layer configuration of the composite filter of Example 3 It is.

  Next, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.

The composite filter for the front surface of the image display device of the present invention is formed by laminating an optical filter composed of at least an external light antireflection layer, a dye-containing layer, and a microlouver layer, and an electromagnetic wave shielding material layer. In addition, the composite filter for the front surface of the image display device of the present invention is provided with a dye-containing layer and a microlouver layer as appropriate except that the external light antireflection layer is disposed on the viewer side and the electromagnetic wave shielding material layer is disposed on the image display device side. In this order, the microlouver layer and the electromagnetic wave shielding layer are each laminated in an appropriate direction.
Hereinafter, the electromagnetic shielding material layer and the optical filter will be described in this order.

[Electromagnetic wave shielding material layer]
FIG. 3 is a schematic plan view showing an example of an electromagnetic wave shielding material layer (hereinafter sometimes simply referred to as “electromagnetic wave shielding material”) of the composite filter for the front surface of the image display device of the present invention. It is an enlarged view of the AA 'cross section in FIG. 3, and the metal layer 4 and the protective layer 9 are layers provided as needed.
5A is a schematic cross-sectional view showing a part of FIG. 4 further enlarged, and FIG. 5B has a metal layer 4 formed on the conductor pattern layer 3. Shows the case.
FIG. 6 is a process chart showing an example of a method for producing an electromagnetic wave shielding material.
As shown in FIG. 4, the electromagnetic wave shielding material 10 of the present invention has a primer layer 2 on the surface of a transparent substrate 1, and a conductor pattern layer 3 is formed on the surface of the primer layer 2, which depends on the manufacturing method. Reflecting the features, as shown in FIG. 5A, the thickness TA of the portion A where the conductor pattern layer 3 is formed in the primer layer 2 is not formed with the conductor pattern layer. The portion B is thicker than the thickness TB.
The conductor pattern layer 3 is composed of conductor particles 3a and a binder resin 3b, and at least a part of the conductor particles 3a is formed of the conductor pattern layer 3 as shown in FIG. 9B or FIG. In observation with an electron micrograph of a cross section, it is possible to form a portion having a chain in which adjacent particles are fused (fused) to each other.

(Transparent substrate)
The transparent substrate 1 which is one of the constituent elements of the electromagnetic wave shielding material layer is a known material and a transparent material (transparent) in the visible light region, considering required physical properties such as heat resistance, mechanical strength, and the like. What is necessary is just to select thickness suitably, and rigid board | plate rigid bodies, such as a transparent inorganic board, such as glass and ceramics, or a resin board, may be sufficient. However, in consideration of suitability for continuous processing with a roll-to-roll having excellent productivity, a flexible resin film (or sheet) is preferable. The roll-to-roll refers to a processing method in which the material is unwound and supplied from a winding (roll), appropriately processed, and then wound and stored in the winding.

Examples of resins for resin films and resin plates include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), ethylene glycol-1,4 cyclohexanedimethanol-terephthalic acid copolymer, ethylene glycol-terephthalic acid-isophthalic acid copolymer. Polymers, polyester resins such as polyester thermoplastic elastomers, acrylic resins such as polymethyl methacrylate, polyolefin resins such as polypropylene and cycloolefin polymers, cellulose resins such as triacetyl cellulose, polycarbonate resins, etc. . Among them, polyethylene terephthalate is a transparent base material whose biaxially stretched film is preferable in terms of heat resistance, mechanical strength, light transmittance, cost, and the like.
Examples of the transparent inorganic material include soda glass, potassium glass, borosilicate glass, lead glass, and other transparent ceramics such as PLZT, quartz, and the like.

The thickness of the transparent substrate is basically not particularly limited and is appropriately selected depending on the application. When a flexible resin film is used, it is, for example, about 12 to 500 μm, preferably about 25 to 200 μm. In the case of using a resin or transparent inorganic plate, the thickness is, for example, about 500 to 5000 μm.
Moreover, in order to ensure the adhesiveness with the primer layer 3, the surface treatment for an adhesive improvement, an easily bonding layer, a base layer, etc. may be provided in the transparent base material surface separately.
As the base layer, for example, when the material of the transparent substrate is made of a polyester resin and the primer layer is made of an acrylate-based ionizing radiation polymerizable composition, the thickness made of a polyester resin, an acrylic resin, a urethane resin, an epoxy resin, etc. A coating film with a thickness of about 0.1 to 1 μm may be used.

(Primer layer)
The primer layer 2 used for the electromagnetic wave shielding material layer of the composite filter is improved in ink (conductor composition) transferability from the plate to the printing material (transparent substrate) when the main purpose is the printing formation of the conductor pattern layer 3. And a layer for improving the adhesion between the conductor composition after transfer and the substrate. That is, both the transparent substrate and the conductor pattern layer have good adhesion, and are also a transparent layer for ensuring the light transmittance of the opening (conductor pattern layer non-formed part).
Further, the primer layer 2 is a layer that is provided on the transparent substrate 1 in a state where fluidity can be maintained, and is formed as a layer that solidifies from a liquid while in contact with the intaglio at the time of intaglio printing. This layer is solidified when a typical electromagnetic shielding material is formed.

The material constituting the primer layer is not particularly limited. However, in the present invention, an ionizing radiation curable composition containing a liquid (fluid) ionizing radiation polymerizable compound in an uncured state is applied and cured ( A layer formed by solidification) is preferably used. Hereinafter, this material will be mainly described in detail.
As the ionizing radiation polymerizable compound, monomers and / or prepolymers that are polymerized and cured by a reaction such as crosslinking with ionizing radiation are used.
Examples of such monomers include radically polymerizable monomers such as methyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, isobornyl (meth) acrylate, and dicyclopentenyl (meth) ) Monofunctional (meth) acrylates such as acrylate, dipropylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate , Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) a Polyfunctional (meth) acrylates of various (meth) acrylates such relations and the like. Here, the expression (meth) acrylate means acrylate or methacrylate. Examples of the cationic polymerizable monomer include alicyclic epoxides such as 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexene carboxylate, glycidyl ethers such as bisphenol A diglycidyl ether, 4-hydroxybutyl vinyl ether And vinyl ethers, and oxetanes such as 3-ethyl-3-hydroxymethyloxetane.
Such prepolymers (or oligomers) include, for example, urethane (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, triazine (meth) acrylate, and silicon (meth) acrylate as radical polymerizable prepolymers. And various (meth) acrylate prepolymers such as polythiol prepolymers such as trimethylolpropane trithioglycolate and pentaerythritol tetrathioglycolate, and unsaturated polyester prepolymers. Other examples of the cationic polymerizable prepolymer include novolac type epoxy resin prepolymer and aromatic vinyl ether type resin prepolymer.
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 employed as the ionizing radiation, a photopolymerization initiator is usually added. As a photopolymerization initiator, in the case of a radical polymerizable monomer or prepolymer, a compound such as a benzophenone-based, thioxanthone-based, benzoin-based, or acetophenone-based compound, or in the case of a cationic polymerization-based monomer or prepolymer, Metallocene, aromatic sulfonium and aromatic iodonium compounds are used. These photopolymerization initiators are added in an amount of about 0.1 to 5 parts by mass with respect to 100 parts by mass of the composition comprising the monomer and / or prepolymer.
In addition, as the ionizing radiation, ultraviolet rays or electron beams are typical, but in addition, electromagnetic waves such as visible rays, X-rays and γ rays, or charged particle beams such as α rays and various ion rays are used. You can also

  When peeling off after the primer layer is cured on the plate surface, if a material system with heavy peeling (good adhesion to the plate) is used, the plate surface may be subjected to release processing or a release agent may be applied. However, considering the processing cost and the life of the release ability, a release agent is added to the primer layer as necessary. The release agent used in the present invention means that the primer layer on the transparent substrate that has undergone the primer curing step in the production of the electromagnetic wave shielding material reduces the force (peeling force) required for peeling from the plate surface and peels off smoothly. Thus, it refers to an additive for improving peelability. Examples of such release agents include higher fatty acid esters, phosphate esters, silicone resin release agents, fluororesin release agents, and the like of mono- or polyhydric alcohols.

  The ionizing radiation curable composition may contain a solvent, but in that case, since a drying step is required after coating, it is a type that does not contain a solvent (non-solvent type or solvent-free type) in consideration of cost. preferable. When a solvent is added for the purpose of improving the appearance or coating applicability, drying is necessary. However, if the amount of the solvent is about several percent, it may be dried after curing. The amount of residual solvent is preferably as small as possible, but may not be completely zero as long as there is no influence on physical properties and durability.

  The thickness of the primer layer 2 [TB; as shown in FIG. 5A, the conductive pattern layer (evaluated by the thickness of the non-formed portion of the conductive pattern layer) is not particularly limited, but is usually 1 μm after curing. The thickness (TB) of the primer layer 2 is usually set to be between the conductor pattern layer 3 and the primer layer 2 and is preferably about 100 μm, preferably 2 μm to 50 μm, more preferably about 5 μm to 20 μm. As a ratio to the total value (total thickness. Altitude difference between the top of the conductor pattern layer 3 and the surface of the transparent substrate 1 in FIG. 5A), it is about 1 to 50%.

(Conductor pattern layer made of a conductor composition)
In the electromagnetic wave shielding material of the present invention, the conductor pattern layer 3 is provided on the primer layer 2 in a predetermined pattern. A typical shape of the pattern in plan view is a mesh shape (mesh or lattice), but other shapes such as a stripe shape (parallel line group or stripe pattern) and a spiral shape are also used. In the case of a mesh shape, the unit cell shape may be a triangle such as a regular triangle or an irregular triangle, a square such as a square, rectangle, trapezoid or rhombus, a polygon such as a hexagon or an octagon, a circle or an ellipse. Used. In addition, for the purpose of reducing moire, a random mesh pattern or a pseudo-random mesh pattern can be used. The line width and the inter-line pitch may be dimensions that are usually employed. For example, the line width can be 5 to 50 μm, and the line-to-line pitch can be 100 to 500 μm. The aperture ratio (ratio of the total area of the openings in the total area of the electromagnetic shielding pattern portion 7) is usually about 50 to 95%. In addition to the electromagnetic wave shielding pattern of the mesh, there may be a case where a grounding pattern such as all solids (no opening) adjacent to each other is provided around the entire periphery or a part of the periphery. This ground pattern may be formed at the same time as the shield pattern is formed, may be formed separately using conductive ink, or may be formed by applying a conductive metal tape or the like. In addition, as a printing method in the case of forming the ground pattern with such a separate conductive ink, since the fine pattern reproduction accuracy is not particularly required, a printing method similar to that of the conductor pattern layer 3 may be used, or a silk screen may be used. Various known printing methods such as print printing, flexographic printing, and offset printing may be used.
The line width is preferably 50 μm or less, preferably 30 μm or less, and particularly preferably 20 μm or less, from the viewpoint of further miniaturization in order to obtain a more highly transparent material.

Further, the thickness of the conductor pattern layer 3 varies depending on the resistance value of the conductor pattern layer 3, but the center of the conductor pattern layer 3 has a balance between electromagnetic shielding performance and suitability for adhesion of other members onto the conductor pattern layer. In the measurement at the part (the top of the projection pattern), it is usually 2 μm or more and 50 μm or less, preferably 5 μm or more and 20 μm or less.
The conductor pattern layer 3 can be obtained by forming a conductor composition (conductor ink or conductor paste) containing the conductor particles 3a and the binder resin 3b on the primer layer 2 by an intaglio printing method. .
In addition, in order that the metal layer 4 can be stably formed on the surface of the conductor pattern layer 3 by electrolytic plating, the surface resistivity of the conductor pattern layer made of the conductor composition is preferably as low as possible. Specifically, it is preferable that the surface resistivity be 2Ω / □ or less. Furthermore, without forming a metal layer on the surface of the conductor pattern layer, and for exhibiting sufficient electromagnetic wave shielding properties in an area where the line width frequently used as an electromagnetic wave shielding mesh is 25 μm or less and the line thickness is 20 μm or less. The lower the surface resistivity of the conductor pattern layer made of the conductor composition, the better. Specifically, the surface resistivity may be 1.2 Ω / □ or less, more preferably 0.8 Ω / □ or less. In order to set the surface resistivity of the conductor pattern layer to 0.8 Ω / □ or less, a metal having a low volume resistivity, such as silver, gold, or copper, is selected as the material of the conductor particles. The average particle diameter of the particles is 1 μm or less, the particle diameter of the conductor particles is a mixed system of small particle diameter particles and large particle diameter particles, the conductor at the top of the conductor pattern layer It is effective to increase the density of the particles and to perform acid treatment or hot water treatment after forming the conductor pattern layer.

The apparent value of the volume resistivity indicating the conductor of the conductor composition itself varies depending on the shape to be printed. For example, compared to the volume resistivity when a commercially available conductive paste is formed in a solid shape (a shape without an opening), the apparent volume resistivity when formed as a pattern is calculated by the following formula: The smaller the shape, the larger.
(Formula): Apparent volume resistivity [Ω · cm] = Surface resistivity of pattern portion [Ω / □] ×
Pattern portion thickness [cm] x pattern occupancy rate-Pattern portion thickness: thickness of pattern formation portion-total thickness of pattern non-formation portion (opening)-Pattern occupancy rate: area of pattern formed portion of unit area For example, the volume resistivity when a commercially available dry-curing silver paste is solidly applied and dried is usually on the order of 10 ⁻⁵ [Ω · cm] or less. Volume resistivity often increases by an order of magnitude or more. This is due to a reduction in the filling rate of silver particles and the chance of contact between the particles. For example, even when the pattern occupancy is the same, the resistance increases as the line width or thickness approaches the particle size of the conductive particles. If an acid treatment or warm water treatment means is used here, this increase in volume resistivity can be suppressed. In particular, by performing the hot water treatment after the acid treatment, the apparent volume resistivity is reduced to a value of 70 to 65% as compared to before the treatment.

The conductive particles constituting the conductive composition include low resistivity metal particles such as gold, silver, platinum, copper, nickel, tin, and aluminum, or high resistivity metal particles and resin particles as core particles. Examples thereof include particles whose surfaces such as inorganic nonmetallic particles are coated with a low resistivity metal such as gold or silver, graphite particles, conductive polymer particles, and conductive ceramic particles.
The shape of the conductor particles can be selected from various polyhedron shapes such as regular polyhedron shape, truncated polyhedron shape, spherical shape, spheroid shape, scaly shape, disc shape, dendritic shape, fibrous shape and the like. In particular, a polyhedral shape, a spherical shape, or a spheroid shape is preferable. These materials and shapes may be appropriately mixed and used.
The size of the conductor particles is arbitrarily selected according to the type, and thus cannot be specified unconditionally, but those having an average particle diameter of about 0.01 to 10 μm can be preferably used. In order to obtain a good electromagnetic wave shielding property by reducing the electric resistance of the obtained conductor pattern layer [as described above, preferably, the surface resistivity (simply abbreviated as surface resistance) is 0.8Ω / □ or less]. The average particle size is preferably small. From this viewpoint, the average particle size is preferably 0.1 to 1 μm. In general, particles having an average particle diameter as small as several tens of nanometers, which are called “nanoparticles”, lead to high costs, and when a binder resin is added, the performance decreases and the stability as an ink also decreases. In addition, regarding the particle size distribution, in order to reduce the electric resistance of the obtained conductor pattern, the distribution width is relatively smaller than that having a narrow distribution width and close to a single particle size. It is better to consist of a mixed system with small particles. For example, a mixed system of small particle diameter particles having a particle diameter of 0.01 μm to 1 μm and large particle diameter particles having a particle diameter of 5 to 10 μm is preferable.
The mixing ratio of both particles in such a mixed system is such that the number of small particles: the number of large particles: 1: 9 to 9: 1, in particular, the number of small particles: the number of large particles: 5: 5. A range of ˜9: 1 is preferred. Naturally, if particles larger than the line width and thickness of the pattern are mixed, the current path due to the contact between the conductive particles tends to be interrupted, and defects such as omissions and streaks occur frequently during printing. The average size or the maximum particle size of the large particle size varies depending on the pattern design. From this point of view, it is preferable that average particle diameter ≦ line width / 4 because these problems are practically solved.
In addition to mixing a plurality of types of particles having different average particle sizes, particles having a certain particle size distribution may be used from the beginning.

The reason why the surface resistivity of the conductor composition (the conductor pattern layer comprising the conductor composition) decreases when the particle diameter of the conductor particles is a mixed system of small and large particle diameters is that When the cross section of the conductive pattern layer formed is observed with a microscope, there is no contact between the large particle diameter particles, because a distributed form in which the small particle diameter particles are filled in the gaps in which the large particle diameter particles are distributed is observed. The gap between the portions is reinforced by the contact of the small particle diameter particles interposed therein, and the total of the electric contact areas between the large and small particles dispersed in the conductor composition is increased (the above formula R = ρL / S _AV It is considered that the effective sectional area S in FIG.
The distribution of the conductive particles in the conductive pattern layer can be selected from various forms according to desired characteristics and manufacturing suitability. As a particularly preferable form, as shown in FIG. In the vicinity of the top of the body pattern layer (in the direction away from the primer layer), the spacing between the particles is relatively small, and the particle number density, that is, the number of particles per unit volume is relatively high. In the vicinity of the bottom of the body pattern layer (direction approaching the primer layer), there is a distribution in which the interval between particles is relatively large and the particle number density is low (sparse or coarse).

In the case of such a distributed form, the electromagnetic wave shielding material of the present invention is installed on the screen of the image display device, that is, the conductor pattern layer side faces the observer side, and the transparent substrate side faces the image observer side. When used in a facing direction, the conductive particles facing the screen side are coarse in density, so that the image light is scattered and the image light is reflected on the screen, thereby causing image whitening and image contrast reduction. This can be prevented and is preferable.
On the other hand, when the conductor pattern layer side faces the image display device side and the transparent substrate side faces the image viewer side, the conductor particles facing the viewer side have a coarse density. Therefore, extraneous light (electric light, sunlight, etc.) is scattered to reduce reflected light, particularly specularly reflected light, that enters the viewer's eyes. As a result, the whitening of the image in the presence of extraneous light and the reflection of the surrounding scenery can be prevented, and the decrease in image contrast can be prevented, which is preferable.
In order to exhibit this effect more effectively, it is more preferable to select a polyhedral, spherical, or spheroid shape as the conductor particle shape rather than a scale shape. It is preferable because a surface close to a mirror surface is hardly formed on the primer layer side surface. Further, when a scale-like material is adopted as the conductor particle shape, the orientation direction of the scale-like conductor particles in the conductor pattern layer (for example, the normal direction of the widest surface of the scale) (Defined) is distributed randomly, which is preferable because specular reflection is reduced. In addition, even when the conductor particle shape is a polyhedral shape, a spherical shape, or a spheroid shape, it is preferable in terms of reducing specular reflection light to make the orientation direction random.
At the same time, the conductive particles facing the image display apparatus gather densely, and the electrical contact between the particles becomes good, the electric resistance is lowered, and the electromagnetic wave shielding effect is enhanced. Of course, the conductive particles distributed at a high density have a high visible light reflectance, but the conductive particles are located on the surface that is not in contact with the image observer (opposite to the observer). There is no worry about a decrease in image contrast or the like.
However, in the present application, since the conductor pattern layer is installed so as to be positioned on the image observer side, the surface of the conductor pattern layer may be subjected to blackening treatment or the like as necessary. .
Further, the structure in which particles are densely present in the vicinity of the top of the conductor pattern layer also has an effect of reducing contact resistance in contact with a grounding component when the mesh is used as an electromagnetic wave shielding member.

The density distribution of the conductor particles in the conductor pattern layer is controlled, and the distribution is relatively sparse in the vicinity of the primer layer as shown in the SEM sectional photograph of FIG. In order to make it dense in the vicinity of the top, or in the vicinity of the primer layer, the orientation direction of the particles becomes messy, and in order to orient the orientation direction in parallel or substantially parallel at the top of the conductor pattern layer, for example, In the method for producing an electromagnetic wave shielding material applying the intaglio printing method as described later (see FIG. 8), the depression on the upper surface of the conductive composition filled in the depression on the plate surface (see reference numeral 6 in FIG. 8A), The pressure for pressing the fluidized primer layer 2 on the transparent substrate is set high, the viscosity of the conductor composition in the uncured state is set low, and the conductor composition is further removed from the intaglio recess. Solidified within Without, it is effective to allowed to solidify after the release from the plate surface.
In addition, the density distribution and orientation state of these conductor particles are determined depending on the binder resin type of the conductor composition, the material and particle diameter and particle shape of the conductor particles, the blending ratio of the binder resin and the conductor particles, and the conductivity. It depends on the coating conditions and solidification conditions of the body composition. Actually, conditions that match the desired density distribution and orientation of the conductor particles are determined experimentally from various conditions that affect the density distribution and orientation state of the conductor particles.
The content of the conductor particles in the conductor composition is arbitrarily selected according to the conductor of the conductor particles and the form of the particles. For example, among the 100 parts by mass of the solid content of the conductor composition, Body particles can be contained in the range of 40 to 99 parts by mass. In the present specification, the average particle diameter refers to a value obtained by averaging the particle diameters measured by a particle size distribution meter or TEM (transmission electron microscope) observation.

As the binder resin constituting the conductor 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, phenol resin, polyimide resin, thermosetting acrylic resin, thermosetting polyurethane resin, and thermosetting polyester resin. As the ionizing radiation curable resin, the above-mentioned materials can be used as the primer material. The thermoplastic resin used alone or in combination of two or more is a thermoplastic polyester resin. , Polyvinyl butyral resin, thermoplastic acrylic resin, thermoplastic polyurethane resin, vinyl chloride-vinyl acetate copolymer, and the like. These may be used alone or in combination of two or more. In addition, when using a thermosetting resin, you may add a curing catalyst as needed. When using an ionizing radiation curable resin, a photopolymerization initiator may be added as necessary.
Further, in order to obtain fluidity suitable for filling the concave portion of the plate, these resins are usually used as a varnish dissolved in a solvent. There are no particular restrictions on the type of solvent used as the conductor paste, and it can be used by appropriately selecting from the solvents generally used in printing inks. Those which do not swell, whiten or dissolve the layer are preferred. The content of the solvent is usually about 10 to 70% by mass, but it is preferably as small as possible within a range where necessary fluidity is obtained. In addition, when an ionizing radiation curable resin is used, a solvent is not necessarily required because it is inherently fluid.

  In addition, in order to improve the fluidity and stability of the conductor composition, as long as it does not adversely affect the adhesion to the conductor, the transparent substrate or the primer layer, a filler, a thickener, and an antistatic agent. , Surfactants, antioxidants, dispersants, anti-settling agents and the like may be added.

Next, the manufacturing method of the electromagnetic wave shielding material will be described in detail with reference to the drawings.
FIG. 6 is a process diagram showing an example of a method for producing an electromagnetic wave shielding material used in the composite filter of the present invention. FIG. 7 is a schematic configuration diagram of an apparatus for carrying out the method for producing an electromagnetic wave shielding material used in the composite filter of the present invention, and FIG. It is a schematic diagram which shows the form which the conductor material composition transcribe | transfers.

In order to manufacture the electromagnetic wave shielding material used for the composite filter of the present invention, the transparent substrate 1 having a primer layer 2 that can maintain fluidity until cured as shown in FIG. 8A is formed on one surface S1. A conductive material composition 15 (3 ′) for forming a cured product having a conductive material after curing is applied to the transparent base material preparation step to be prepared and the plate or cylindrical plate surface 63 on which the conductive pattern is formed. After that, the filling material step of scraping off the conductive material composition adhering to other than the inside of the concave portion and filling the conductive material composition 15 into the concave portion 64, the concave portion 64 side of the plate surface 63 after the filling step, and the transparent substrate A pressure-bonding step (see FIG. 8B), in which the primer layer 2 side of the transparent substrate 1 after the preparation step is pressure-bonded, and the conductor material composition 15 and the primer layer 2 in the recess 64 are in close contact with each other without a gap; A primer that hardens the primer layer 2 after the crimping process A curing step, and a transfer step (see FIG. 8C) in which the transparent base material 1 is peeled off from the plate surface 63 after the primer curing step and the conductor material composition 15 (3 ′) in the recess is transferred onto the primer layer 2. And a curing step of forming a conductive layer formed by curing the conductor composition layer 3 ′ formed in a predetermined pattern on the primer layer 2 after the transfer step.
In addition, hardening of this primer layer and hardening of a conductor composition can also be performed simultaneously. In that case, the primer curing step and the curing step for forming the conductive layer are combined in one step. Thereafter, the transfer step is performed.

(Electrical resistance reduction treatment process)
After the conductive composition is cured to form a conductive layer, the surface resistivity of the conductive layer is reduced by passing through an acid treatment step, a hot water treatment step, or both an acid treatment and a hot water treatment step, thereby reducing electromagnetic waves. The shielding performance can be improved. This phenomenon is observed particularly when the conductive particles are silver or particles containing silver. This process is also referred to as an electrical resistance reduction process. Unlike so-called baking treatment, this is not a long-time heat treatment that damages a general film substrate such as PET, and is not a dispersion of nano-sized particles known as printing ink for low-temperature baking, but a resin It is extremely effective as a treatment method when a conductive ink having a general property including a binder is used.

[Conductor pattern layer]
The conductive pattern layer of the electromagnetic wave shielding material used for the composite filter of the present invention has a mesh shape (this form is also referred to as a conductive mesh pattern layer), and there are two or more parallel line groups having different directions. The line portions made of crossing each other and surrounded by these line portions form an opening (non-pattern forming portion). Even when three or more parallel line groups (line parts) cross, the basic design points and operational effects are the same. I will explain. Further, the crossing angle of each line group, that is, the crossing angle θ between the first direction line part and the second direction line part can be selected from the range of 0 ° <θ <180 °, but θ = 90 ° (square lattice) Is usually widely used.

[Metal layer (plating layer)]
The electromagnetic wave shielding material used in the composite filter of the present invention is shown in FIGS. 4 and 5 in order to further improve the conductor when only the conductor pattern layer 3 made of the conductor composition is insufficient for the desired conductor. As shown in (B), the low resistivity metal layer 4 can be formed as needed, and is formed on the conductor pattern layer 3 by plating. As plating methods, there are methods such as electrolytic plating and electroless plating, but electroplating can increase the plating rate several times by increasing the amount of current compared to electroless plating, which significantly improves productivity. This is preferable.
In the case of electrolytic plating, power supply to the conductive pattern layer 3 is performed from an electrode such as a current-carrying roll brought into contact with the surface on which the conductive pattern layer 3 is formed, but the conductive pattern layer 2 can be electroplated. Since it has a conductor (usually 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 the like, which have high conductivity and can be easily plated.
Since the metal layer generally has a volume resistivity smaller than that of the conductor pattern layer 3 by one digit or more, the amount of the conductor material required is smaller than when the conductor pattern layer alone secures electromagnetic wave shielding. There is an advantage that it can be reduced.
In FIG. 6, a metal plating process, a blackening process, or the like can be performed in the additional processing zone as necessary.

  Note that after the metal layer is formed, the metal layer may be blackened or a protective layer 9 (see FIG. 4) may be provided as necessary. Examples of the blackening treatment include blackening nickel plating and copper-cobalt alloy plating, but are not necessarily limited to these treatments. The protective layer is a layer that covers and protects the surface of the conductor pattern layer. Normally, as shown in FIG. 4, the protective layer also fills the irregularities of the conductor pattern layer 3 and also functions as a so-called flattening layer for flattening the surface. The protective layer can be formed using, for example, an acrylic ultraviolet curable resin. When the metal used for the conductor pattern layer or metal layer is a metal that tends to rust, such as copper, it is preferable to perform a rust prevention treatment, and a general rust prevention agent such as a chromate treatment agent can be used. May also serve as a blackening treatment or protective layer formation.

[Optical filter]
The composite filter for the front surface of the image display device of the present invention is a composite filter having both an electromagnetic shielding function and an optical function by laminating various functional layers including an optical functional layer on the surface of the electromagnetic shielding material. Is. In the composite filter according to the present invention, first, a layer selected from an antireflection layer made of a low refractive index layer or an antiglare layer is disposed on the viewer side as an external light antireflection layer. Further, as the optical functional layer, for example, a dye-containing layer having functions of near infrared absorption, neon light absorption, color matching, and / or ultraviolet absorption, and a microlouver layer as a contrast enhancement layer are arranged in an appropriate order. If necessary, the optical filter can be further combined with a functional layer that expresses functions other than the optical function. Examples of such a layer include an impact resistant layer, an antistatic layer, a hard coat layer, an antibacterial layer, and an antifouling layer.
Here, when the functional layer is formed on the surface of the electromagnetic wave shielding material layer on the conductor pattern layer side, there are a method of directly forming and a method of bonding a separately formed functional layer. In the case of direct formation, it is possible to use a method of applying a material exhibiting a function on the surface of the conductor pattern layer using a coating apparatus, or a general method such as sputtering or vapor deposition. In any case, when laminating on the electromagnetic wave shielding material layer side, it is preferable that the electromagnetic wave shielding material layer used in the present invention is a layer having good adhesion to the primer layer serving as an adhesive surface.

General equipment such as gravure (roll) coating, roll coating, comma coating, stencil printing, and die coating can be used to apply and form functional materials. Select as appropriate. In addition, if it is necessary to expose a part of the conductor pattern layer in the surface, pattern forming method during stencil pattern printing, intermittent coating, stripe coating, etc. It is possible to use a method of removing the mask after coating the entire surface by masking or removing a functional layer at an unnecessary portion.
When the directly formed functional layer is located at the interface (the outermost surface or the rearmost surface of the filter) in contact with air, it is flattened in order to suppress image quality degradation due to scattering of image light and external light and the lens effect. Preferably it is.
The directly formed functional layer may exhibit a function in a single layer or may exhibit a function in a plurality of layers. Examples of single layers include a hard coat function, a flattening function, a near infrared absorption function, a neon light absorption function, an ultraviolet absorption function, a toning function, an external light antireflection function (including an antiglare function), and an impact resistance function One or a plurality of functions such as an antistatic function and an antifouling function may be exhibited. In the case of a plurality of layers, for example, a flattening layer + an external light antireflection layer, an external light antireflection layer + a hard coat layer It is possible to share functions such as an infrared absorption layer + a hard coat layer.
When the functional layer to be applied and formed is a scratch-resistant (hard coat) layer, it is preferable that the pencil hardness test specified by JISK5600-5-4 (1999) exhibits a hardness of “H” or higher. The material is not particularly limited as long as such hardness and transparency similar to the above-described transparent (resin) substrate can be realized. As the curable resin to be used, an ionizing radiation curable resin, other known curable resins, or the like may be appropriately employed according to required performance. An example of the ionizing radiation curable resin is omitted here because it is exemplified in the description of the material of the primer layer of the electromagnetic wave shielding material layer.

[Outside light reflection prevention layer]
As an external light antireflection layer, external light (external light) incident on the image display device from the outside, such as sunlight and electric light, is reflected on the screen, particularly caused by specular reflection, and the screen is whitened or image contrast (white) This is a layer having a function of reducing a problem that a luminance ratio between an image and a black image is lowered or reflected on a main landscape image screen. As such an external light antireflection layer, an antireflection layer or an antiglare layer comprising a low refractive index layer is used. The external light antireflection layer is formed on the outermost surface (most image viewer side) of the composite filter for the front surface of the image display device.
The antireflective layer composed of the low refractive index layer may be a single low refractive index layer, or a low refractive index layer and a high refractive index layer alternately so that the low refractive index layer is positioned at the top layer. A laminated multilayer structure is common.
Here, the low refractive index layer means a layer having a relatively low refractive index compared to a layer adjacent to the layer (a transparent base sheet or a high refractive index layer). The high refractive index layer means a layer having a relatively high refractive index compared to a layer adjacent to the layer (transparent substrate sheet or low refractive index layer).
In general, on a substrate H having a relatively high refractive index n _H (when a low refractive index layer is laminated on a high refractive index layer, this corresponds to the high refractive index layer). It has a low refractive index n _L than, and the thickness is laminated a low refractive index layer L of h _L.
In this case, the refractive index of both is;
If it is selected to satisfy the above relationship, the reflectance of the surface of the low refractive index layer L is minimized. Even if the refractive index relationship exactly as shown in this equation cannot be realized, if the relationship as close as possible is as close as possible to this equation, the reflectance of the surface will be lower than when the low refractive index layer L is not provided.
Even when (Equation 1) is satisfied, the reflectance of the surface of the low refractive index layer L varies depending on the wavelength of light and the thickness h _L of the low refractive index layer L. And;
(Formula 2) h _L = λ _max / 4n _L1
At a wavelength λ _max that satisfies the above, the reflectivity is minimized. Along with this, the antireflection layer is somewhat colored by this wavelength λ _max (red, blue, green, etc.). Therefore, when it is desired to minimize the reflectance at a desired wavelength, or when the color tone of the antireflection layer surface is adjusted to a desired color tone, the thickness h _L of the low refractive index layer L is set by (Equation 2). design.

As a material constituting the low refractive index layer, silicon oxide, fluoride, or the like is used as an inorganic material. Specifically, SiO ₂ (refractive index n = 1.45), MgF ₂ (refractive index n = 1.38), CaF ₂ (refractive index n = 1.44), 3NaF · AlF ₃ (refractive index n = 1). .4) etc. Examples of the organic material include a fluorine-based organic compound (fluorine resin) and a silicon-based organic compound.
Further, fine particles having voids may be used for the low refractive index layer. The fine particles having voids form a structure in which fine particles are filled with gas and / or a porous structure containing gas, and are in inverse proportion to the gas occupancy ratio in the fine particles compared to the original refractive index of the fine particles. It means fine particles having a reduced refractive index.
Further, in the present invention, fine particles capable of forming a microporous structure inside and / or at least part of the surface depending on the form, structure, aggregated state, and dispersed state of the fine particles inside the coating film. Is also included. The fine particles having voids may be either inorganic or organic, and include, for example, those made of metal, metal oxide, and resin, and preferably silicon oxide (silica) fine particles.
Furthermore, a material obtained by mixing a sol obtained by dispersing ultrafine silica particles of 5 to 30 nm in water or an organic solvent and a film forming agent of a fluorine-based resin can be used.

As a method for forming a low refractive index layer (film forming method), in the case of an inorganic material, the above-mentioned material itself is formed by a vapor phase method such as vacuum deposition, sputtering, plasma CVD, ion plating, etc. The coating material, which is formed on the upper or high refractive index layer, or finely divided into the above materials and dispersed in an appropriate resin binder and diluted with a solvent, is applied by a wet coating method such as spin coating, roll coating, or die coating. Coating on the base material or high refractive index layer by the construction method, drying and removing the solvent, if necessary, curing by causing crosslinking or polymerization reaction with heat or radiation (ultraviolet rays, electron beam, etc.) It can be obtained by (or solidifying).
In the case of organic materials, this is dissolved or dispersed in a solvent as appropriate to form a paint, and then applied onto a transparent substrate film or high refractive index layer by a wet coating method such as spin coating, roll coating, or die coating. It can be formed by coating, removing the solvent by drying, and further curing (or solidifying) by causing a crosslinking or polymerization reaction with heat or radiation (ultraviolet rays, electron beam, etc.) as necessary. .

As materials constituting the high refractive index layer, inorganic materials such as ZnO (refractive index n = 1.9), TiO ₂ (refractive index n = 2.3 to 2.7), CeO ₂ (refractive index n) are used. = 1.95), ZrO ₂ (refractive index n = 2.05), and the like. Examples of organic materials include polyester resins and styrene resins.
As a method for forming a high refractive index layer (film forming method), in the case of an inorganic material, it is formed on a transparent base film or a low refractive index layer that is not the outermost surface layer by the vapor phase method as described above. Alternatively, it can be formed by wet coating.
In the case of an organic material, it can be formed by coating on a transparent substrate film or a low refractive index layer that is not the outermost surface layer by the wet coating method as described above.

The antiglare layer is basically roughened on the light incident surface in order to scatter or diffuse external light. In this roughening treatment, a method of forming a rough surface directly on the surface of the transparent substrate film by a sandblasting method or an embossing method; roughening the surface of the transparent substrate film by either radiation or heat or a combination thereof. A method of providing a roughened layer in a resin binder with a coating containing inorganic fillers such as silica or organic fillers such as resin particles as light diffusing particles; and forming a porous film with a sea-island structure on the substrate surface And the like. As the resin of 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 because surface strength is desired as the surface layer.
The thickness of the antiglare layer is not particularly limited, but is preferably 0.07 μm or more and 20 μm or less.
Further, when the average interval between the irregularities of such an antiglare layer is Sm, the average inclination angle of the irregularities is θa, and the ten-point average roughness of the irregularities is Rz, Sm is 60 μm or more and 250 μm or less, and θa Is preferably 0.3 ° to 1.0 °, and Rz is preferably 0.3 μm to 1.0 μm.
Here, Rz, Sm, and θa are defined as follows.
«Average interval of unevenness Sm (μm), average inclination angle θa, 10-point average roughness (Rz)»
When the surface of the antiglare layer has a concavo-convex shape, Sm (μm) represents the average interval of the concavo-convex of this antiglare layer, θa (degree) represents the average inclination angle of the concavo-convex part, and (Rz) is Represents 10-point average roughness.
The definitions of these terms are based on JIS B0601 1994 and are also described in the instruction manual (revised 1995, 07, 20) of the surface roughness measuring device (model number: SE-3400 / manufactured by Kosaka Laboratory).

(Dye-containing layer)
The dye-containing layer can be a dye-containing pressure-sensitive adhesive layer that also serves as a pressure-sensitive adhesive layer for adhering the functional layer constituting the composite filter, or can be an independent layer coated and formed on a transparent substrate. it can. In the dye-containing layer, an absorbent (dye) described below is appropriately blended.

(Near infrared absorber)
When the near-infrared absorber is applied to a PDP which is a typical use of the optical filter of the present invention, a near-infrared region generated when the PDP emits light using xenon gas discharge, that is, a wavelength region of 800 nm to 1100 nm. In the visible light region, that is, in the wavelength region of 380 nm to 780 nm, a dye having a sufficient light transmittance is preferable. And when adding to the adhesive layer, the near-infrared absorption amount in the near-infrared region is 20% or less in terms of transmittance, more preferably 10% or less, It is preferable to set the content of the near-infrared absorber in the adhesive layer, the thickness of the adhesive layer, and the like.
Specific examples of such near infrared absorbers include phthalocyanine, imonium, diimonium, dithiol metal complexes, cyanine compounds, azo compounds, polymethine compounds, quinone compounds, diphenylmethane compounds, triphenylmethane. Organic near-infrared absorbers composed of organic compounds such as organic compounds, or inorganic near-infrared absorbers composed of inorganic compounds such as metal oxides, metal borides, and metal nitrides. From the viewpoint of properties, an inorganic near-infrared absorber is preferable.
Among these, examples of the metal oxide include tungsten oxide compounds, titanium oxide, zirconium oxide, tantalum oxide, niobium oxide, zinc oxide, ruthenium oxide, indium oxide, tin-doped indium oxide (ITO), tin oxide, and antimony dope. Examples thereof include fine particles such as tin oxide (ATO) and cesium oxide.
Among these, tungsten oxide compounds are preferred from the viewpoint of compatibility between high absorption of near infrared rays and high transmittance of visible light, and durability against changes in spectral transmittance characteristics under high temperature and high humidity conditions, In particular, cesium-containing tungsten oxide is particularly suitable because it has a high near-infrared absorbing ability.
It is preferable that content of the said near-infrared absorber is about 0.1-15 mass% in an absorption layer.

(Neon light absorber)
The neon light absorber is a dye that absorbs neon light emitted from the PDP when applied to the PDP which is a typical use of the composite filter of the present invention. The neon light absorbs the emission spectrum band of neon atoms, that is, the wavelength region of 550 to 640 nm (neon light region), and absorbs as little as possible in the visible light region of 380 nm to 780 nm excluding the wavelength region. And a dye having sufficient light transmittance is preferred.
And when adding to the adhesive layer, if the central wavelength of the Ne light region is 590 nm, the adhesive agent of the neon light absorber is such that the light transmittance at 590 nm is 50% or less. It is preferable to set the content in the layer, the thickness of the adhesive layer, and the like.
Specific examples of such neon light absorbers include cyanine, oxonol, methine, subphthalocyanine or porphyrin. Among these, porphyrins are preferable, and tetraazaporphyrin-based dyes are preferable from the viewpoints of good dispersibility and good heat resistance, moisture resistance, and light resistance.
The neon light absorber content is preferably 0.05 to 5% by mass in the neon light absorption layer. If the content is 0.05% by mass or more, a sufficient neon light absorbing function can be exhibited, and if it is 5% by mass or less, a sufficient amount of visible light can be transmitted.

(Toning light absorber)
The toned light absorber is a pigment for correcting the display image to a desired color tone (natural color or a color slightly deviated from the natural color). As such a toned light absorber, organic dyes, inorganic dyes, and the like can be used alone or in combination of two or more. Specific examples include anthraquinone, naphthalene, azo, phthalocyanine, pyromethene, tetraazaporphyrin, squarylium, and cyanine dyes.
The content of the toning light absorber is appropriately adjusted according to the color to be corrected and is not particularly limited. Usually, about 0.01-10 mass% is contained in the toning layer.

(UV absorber)
Examples of the ultraviolet absorber include salicylate-based, benzophenone-based, benzotriazole-based, substituted acrylonitrile-based, triazine-based organic compounds, titanium dioxide, zinc oxide, cerium oxide, and the like, or titanium dioxide particles. Known compounds composed of inorganic compounds such as a hybrid inorganic powder obtained by complexing iron with iron oxide and a hybrid inorganic powder obtained by coating the surface of cerium oxide fine particles with amorphous silica can be used.
When an ultraviolet absorber is added, in order to protect other absorbers (dyes) from extraneous light, the layer is the same as the layer to which other absorbers (dyes) are added, or the observer side of the layer. Add to a layer close to. In addition, when a dye having a fast light resistance is used, it is not necessary to add an ultraviolet absorber.

[Microlouver layer]
As the micro louver layer, those described in JP 2007-272161 A can be suitably used. As shown in FIG. 11, the microlouver layer is formed by embedding a plurality of light-absorbing wedge-shaped portions 400 in parallel with each other at a constant period in a transparent resin layer 300. Such a microlouver layer (300 + 400; hereinafter, a combination thereof may be represented by the symbol CRF as shown in FIG. 12) selectively absorbs external light such as sunlight and electric light by the light-absorbing wedge 400, Light is transmitted from the transparent resin layer 300 between the light-absorbing wedge-shaped portions 400 to improve image contrast in the presence of external light.

  The microlouver layer (image contrast improving layer) used in the composite filter of the present invention is, for example, a straight line arranged in parallel on the viewer-side surface of the transparent substrate along the in-plane direction of the transparent substrate. A light-absorbing wedge-shaped portion 400 having a trapezoidal or substantially trapezoidal dark color portion and a transparent resin layer 300 forming a light-transmitting region between the adjacent dark color portions, The width of the dark color portion increases toward the viewer side, the width of the translucent region composed of the transparent resin layer 300 decreases toward the viewer side, or the width of the dark color portion composed of the light absorbing wedge-shaped portion 400 An image contrast improving layer that decreases toward the viewer side and the width of the translucent region increases toward the viewer side, wherein the dark color portion is in a groove-shaped recess having a trapezoidal or substantially trapezoidal cross section. It is filled with dark particles and transparent resin Translucent regions, those whose surface is covered with a transparent protective layer made of a transparent resin can be preferably used. Hereinafter, the configuration of the micro louver layer will be described.

(Transparent resin layer)
As the transparent resin layer 300, various kinds of resin materials such as ionizing radiation curable resins, thermosetting resins, and thermoplastic resins, or inorganic transparent materials such as glass can be used. Usually, a resin material is preferably used in that it is easy to form the groove-like recess 43, can be light and thin, and is excellent in flexibility. The ionizing radiation curable resin and the thermosetting resin can be selected from those similar to those exemplified in the explanation of the transparent resin of the primer layer. Examples of the thermoplastic resin include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin resins such as polyethylene, polypropylene, cyclic polyolefin, and polymethylpentene, polyvinyl chloride, and polyvinylidene chloride. Styrenic resins such as halogen resins, polystyrene, acrylonitrile-styrene copolymers, cellulose resins such as triacetyl cellulose, diacetyl cellulose, and acetate butyrate cellulose, thermoplastic polyurethane resins, polycarbonate resins, polyamide resins, and the like can be used.

  Since the groove-like recess 43 is formed in the transparent resin layer 300, the thickness thereof needs to be thicker than the depth H of the groove-like recess 43, and is usually in the range of about 20 μm to 5000 μm. That is, the transparent resin layer 300 can take various forms of a so-called film, sheet, or plate in terms of thickness.

(Absorbing wedge-shaped part)
The light-absorbing wedge-shaped portion (hereinafter, also referred to as “dark color portion”) 400 is formed on one surface S1 of the transparent resin layer 300, and is arranged in parallel along the in-plane direction of the transparent resin layer 300. The cross-sectional shape that is straight and orthogonal to the extending direction is a trapezoidal or substantially trapezoidal shape. The dark-colored portion 400 is configured by filling the dark-colored particles 41 and the transparent resin 42 in the groove-shaped concave portion 43 having a trapezoidal or substantially trapezoidal cross-sectional shape.

First, the shape of the groove-shaped recess 43 will be described. The groove-shaped recess 43 has a trapezoidal or substantially trapezoidal cross-sectional shape. Here, the cross-sectional shape refers to a cross-sectional shape orthogonal to the extending direction of the groove-shaped recess 43 extending linearly. Further, as shown in FIG. 11A, the trapezoidal groove-like recess has a width W of a side (lower base) on one surface S1 side (observer side or image display device side) of the transparent resin layer 300. It is configured in such a manner that the width of the side (upper base) on the other surface S2 side (image display device side or observer side) is narrow. In addition, the substantially trapezoidal groove-shaped recess includes a shape having a small difference in width between both sides (upper base and lower base), that is, a shape close to a rectangle or a square. Also included is a shape approximating a triangle cut parallel to the side (bottom base). The groove-shaped recess 43 is not limited to such a trapezoid or a substantially trapezoid, but may be a square such as a square or a rectangle, or a polygon such as a triangle or a pentagon, but is preferably a trapezoid or a substantially trapezoid as described above. is there.

  The angle θ between the inclined surface 45 formed by the interface between the groove-shaped recess 43 and the transparent resin layer 300 and the normal line of the light exit surface is preferably formed at a predetermined angle, for example, θ is in the range of 3 ° to 15 °. It is preferable that When θ is within this range, the display light from the image display device can sufficiently reach the viewer side, and an effect of improving luminance can be obtained. Moreover, external light incident on the screen in an oblique direction can be absorbed by the light-absorbing wedge 400 having a sufficient cross-sectional area, so that reflection of external light can be suppressed and image contrast can be improved.

  The length of the larger base of the groove-like recess 43 (that is, the maximum width W) is preferably about 10 μm to 100 μm, and the depth H is preferably about 10 μm to 200 μm. The period (pitch) is preferably about 10 μm to 900 μm, and the aperture ratio is preferably about 50% to 90%.

  Next, the material constituting the dark color portion 400, that is, the material filled in the groove-shaped recess 43 will be described. The dark color part 400 absorbs most of the visible light wavelength range and preferably absorbs incident visible light (external light) at a high rate. As a result, the external light reflected by the dark color part 400 is inconspicuous. Even if the reflected light is mixed into the image light, the decrease in the image contrast becomes inconspicuous. Therefore, it is desirable to set the dark color portion 400 to a color that exhibits such an effect. The dark color portion 400 is ideally completely black, but it is not necessary to be completely black for practical use, and may be a chromatic color as long as it exhibits the above action. Specifically, it may be an achromatic color such as black or dark gray, or a low-lightness chromatic color such as brown, rosy, dark blue, dark green, or dark purple.

  As the dark particles 41 constituting the dark portion 400, particles of each color having a predetermined particle diameter can be used. For example, as black particles, black pigments such as carbon black (black) and black iron oxide, resin particles obtained by staining transparent particles such as acrylic with black pigments such as carbon black, and the like are used.

The dark particles 41 may be pigment particles that are achromatic by mixing various pigments of blue, purple, yellow, and red other than black particles, or resin particles that are dyed with these pigments. Also good. Copper phthalocyanine blue, indanthrene blue, cobalt blue, ultramarine blue, etc. are used as the blue pigment, dioxazine violet etc. are used as the purple pigment, and disazo yellow, isoindolinone yellow, yellow lead are used as the yellow pigment. As the red pigment, chromophthal red typel, quinacridone red, petal or the like is used, and as the green pigment, copper phthalocyanine green, patina or the like is used. Further, it may be a dark particle 1 having a chromatic color with low brightness, and as an example, one or more of the above-mentioned blue, purple, yellow, red, or green pigments are appropriately mixed and dispersed. If necessary, it may be a colored pigment further mixed with a black pigment, or resin particles obtained by coloring transparent particles such as acrylic with these pigments. Among these dark particles 41, black particles are preferable because they have the highest light absorption and do not affect the hue of the image contrast improving layer itself.

The particle diameter of the dark color particles 41 is usually arbitrarily selected from the range of 0.1 μm to 100 μm.
Various materials such as ionizing radiation curable resin, thermosetting resin, and thermoplastic resin can be used as the transparent resin 42 that constitutes the dark color portion 400 together with the dark color particles 41. The ionizing radiation curable resin means a resin that is cured by crosslinking or polymerization reaction by irradiation with electromagnetic waves or charged particle beams such as ultraviolet rays or electron beams, as already described. As such an ionizing radiation curable resin, those already described for the primer layer can be used, and the description thereof is omitted here.

(Translucent area)
The translucent region 50 is located between the adjacent dark color portions 400, 400, and the surface S1 of the transparent resin layer 300 is covered with the transparent protective layer 42L. In the transparent protective layer 42L, only the transparent resin 42 filled in the groove-shaped recess 43 together with the dark particles 41 is a groove-shaped recess non-formation portion (also referred to as a protrusion or a translucent opening) of the transparent resin layer 300. That is, the light-transmitting region 50 is covered. The thickness t of the transparent protective layer 42L is defined by the relationship between the minimum particle size and the maximum particle size of the dark color particles 1 to be used, and is in a range of 0.1 μm to 30 μm as long as the relationship described later is satisfied. It is preferable. If the thickness t of the transparent protective layer 42L is less than 0.1 μm, the transparent protective layer 42L formed on the convex portion which is the flat portion 47 other than the groove-shaped concave portion 43 of the transparent resin layer 300 is polished or wiped in a normal manufacturing method. It is difficult to realize without the use, and it is insufficient as a protective layer mainly from contamination and scratches on the surface of the translucent region 50. On the other hand, when the thickness t of the transparent protective layer 42L exceeds 30 μm, it is not preferable because the surface protecting function becomes excessive quality and unnecessary price increases. In order to protect the transparent protective layer 42L from contamination and scratches, an ionizing radiation curable resin or a thermosetting resin having high hardness and excellent scratch resistance is preferable.

(Transparent adhesive layer)
An adhesive layer is a layer which has a role which adhere | attaches the front filter for display apparatuses of this invention to an image display apparatus main body. Even if bonding fails due to misalignment, wrinkles, etc., re-peeling and re-bonding are possible. Further, there is an advantage that the filter can be easily separated and collected when the display device is discarded.

The pressure-sensitive adhesive used for the pressure-sensitive adhesive layer is basically not particularly limited, and has a tackiness (adhesive force), transparency, coating suitability, etc., among the known pressure-sensitive adhesives, and preferably itself. An uncolored one is appropriately selected.
Adhesive layer has sufficient adhesive strength to prevent natural peeling and falling off under normal use conditions of storage, transportation, and image display device, and has re-peelability that can be reattached. The adhesive strength of 200 is preferably 5 to 8 N / 25 mm width (adhesive strength measured by a 180 ° C. peel test in accordance with JIS Z0237).
Examples of such adhesives include acrylic adhesives, rubber adhesives, and polyester adhesives.

  In the pressure-sensitive adhesive layer of the present invention, the coating liquid comprising a pressure-sensitive adhesive solution obtained by dissolving the pressure-sensitive adhesive in an appropriate solvent is used as the back surface of an arbitrary functional layer or (if it is not present) as an image contrast improving layer CRF. It is formed by coating on the back surface (S2 surface) of the microlouver layer (300 + 400), forming a coating film, and then drying.

The thickness of these pressure-sensitive adhesive layers is preferably in the range of 5 to 800 μm. When the thickness is 5 μm or more, the function as a pressure-sensitive adhesive can be sufficiently achieved, and sufficient adhesion with a glass substrate or an image display device can be obtained. The predetermined unnecessary radiation can be sufficiently absorbed. The thickness of the pressure-sensitive adhesive layer is more preferably in the range of 10 to 500 μm, particularly preferably in the range of 20 to 300 μm.
In addition, by setting the thickness of the pressure-sensitive adhesive layer to 200 μm or more, it is possible to provide a function as an impact resistant layer that absorbs and reduces the impact force applied to the image display device.

FIG. 2 shows a schematic cross-sectional view of one example of a specific example of the optical function layer Fopt laminated with the electromagnetic wave shielding material layer 10. The optical functional layer Fopt in FIG. 2 includes an external light antireflection layer 100, a transparent base sheet 200, a microlouver layer (300 and 400), and a blocking (barrier) layer in order from the image observer side (upper side in FIG. 2). 500 and the dye-containing pressure-sensitive adhesive layer 600 are laminated in this order.
The external light antireflection layer 100 is selected from an antireflection layer made of a low refractive index layer or an antiglare layer. In the case of the antireflection layer composed of a low refractive index layer, it is composed of a layer of a material having a lower refractive index than the adjacent transparent base sheet 200 immediately below. For example, a magnesium fluoride vapor-deposited film, a fluororesin coating film in which hollow silica particles are dispersed, and the like are used.
The transparent substrate sheet 200 is appropriately selected from the same materials as the transparent substrate 1. For example, a polyethylene terephthalate sheet is used.
The microlouver layers (300 and 400) are as described above, and a plurality of light-absorbing wedge-shaped portions 400 are embedded in the transparent resin layer 300 in parallel with each other at a constant period. Such a micro louver layer (300 + 400) selectively absorbs external light such as sunlight and electric light by the light absorbing wedge-shaped portion 400, and image light is transmitted through the transparent resin layer 300 between the light absorbing wedge-shaped portions 400 to be external. Improve image contrast in the presence of light.

  The blocking layer 500 is a layer for preventing the dye in the dye-containing pressure-sensitive adhesive layer 600 from reacting with the substance in the microlouver layer (300 + 400) and changing its absorption spectrum. Substances that can change the absorption spectrum of the dye include: (1) the transparent resin layer 300 of the microlouver layer when the dye-containing pressure-sensitive adhesive layer 600 contains an organic dye such as a diimonium compound or tetraazaporphyrin. Is made of a (meth) acrylate-based ultraviolet curable resin, an unreacted residue or decomposition product of a photoinitiator such as acetophenone or benzophenone, or (meth) acrylate constituting the ultraviolet curable resin composition In the case of containing a dye containing a transition metal atom such as iron oxide in the light-absorbing wedge 400, such as an unreacted monomer or (meth) acrylate prepolymer, a dye containing these transition metal atoms And an uncured residual resin of an ultraviolet curable resin. In the case of a combination of such a substance and a dye in the dye-containing pressure-sensitive adhesive layer, for example, a layer having a glass transition temperature of 80 ° C. or higher and a thickness of about 1 to 20 μm of polymethyl methacrylate can be mentioned.

FIG. 1 is a schematic cross-sectional view of a composite filter Fcom formed by laminating the optical function layer Fopt and the electromagnetic wave shielding material 10. The composite filter having the configuration shown in FIG. 1 has its transparent substrate 1 side directly bonded on the screen of the image display device via a transparent adhesive layer, or on the filter substrate via a transparent adhesive layer. Then, after being bonded, they are further mounted on the screen front of the image display device.
Note that the optical function layer Fopt in FIG. 1 or FIG. 2 is merely an example, and the configuration can be appropriately changed as necessary. As a modification of FIG. 1 or FIG. 2, for example, in FIGS. 1 and 2, the microlouver layers (300 and 400) are arranged on the image display device side (FIG. 1 and FIG. On the contrary, the bottom of the light-absorbing wedge-shaped portion 400 faces the image display device side (downward in FIGS. 1 and 2). May be.
Alternatively, in FIG. 1 and FIG. 2, an antireflection layer composed of a low refractive index layer is used as the external light antireflection layer 100. Instead of this, fine irregularities are formed on the surface of the transparent coating film. Alternatively, an antiglare layer having a configuration in which light diffusing particles are dispersed in a transparent coating film may be used.

Alternatively, in FIG. 1 and FIG. 2, all the dyes are added to the dye-containing pressure-sensitive adhesive layer 600, but instead, the dyes are dispersed in the dye-containing pressure-sensitive adhesive layer 600 and other layers. It may be added. For example, in the dye-containing pressure-sensitive adhesive layer 600, a coloring dye and a neon light absorbing dye are added, and the near infrared absorbing dye is a near infrared absorbing dye between the base sheet 200 and the transparent resin layer 300 of the microlouver layer. It can form as a coating film containing.
Furthermore, in FIG.1 and FIG.2, all the pigment | dyes are added in the pigment | dye containing adhesive layer 600, and the transparent base material sheet 200 and the transparent resin layer 300 are laminated | stacked directly, However, instead of this, for example, transparent A coating film containing a near-infrared absorbing dye in a resin binder is formed on the image display device side (the lower side in FIGS. 1 and 2) of the base sheet 200, and the coating film side and the transparent resin layer 300 are formed. The viewer side (the upper side in FIGS. 1 and 2) is laminated via a colorless transparent adhesive layer without addition of a dye, and in the dye-containing adhesive layer 600, colored dye and neon light are laminated. Absorbing dyes can be added.
Alternatively, in the various forms exemplified above, an ultraviolet absorbing dye may be further added to the base sheet 200.
When the intensity of the electromagnetic wave radiated from the image display device is relatively weak and the influence on surrounding devices can be ignored, the electromagnetic wave shielding material layer 10 is omitted and the optical function layer Fopt having the configuration as shown in FIG. Is adhered directly on the screen of the image display device via the dye-containing pressure-sensitive adhesive layer 600, or is adhered to the filter substrate via the dye-containing pressure-sensitive adhesive layer 600, and then the image display device. It can also be attached to the front of the screen.

(Image display device)
An image display device according to the present invention is characterized in that a composite filter including the electromagnetic wave shielding material and the optical filter is provided on a display surface of the image display device. In such an image display device, even if the image display device is used in a place where external light is incident, the contrast is not lowered, and the brightness and image quality of the image are not lowered. Infrared light, neon light, and electromagnetic waves can be prevented from being emitted to the viewer side.
Examples of the image display device include a conventionally known display, for example, LCD, CRT, ELD, etc. in addition to PDP.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

[Preparation of transparent substrate]
As a transparent substrate 1, a polyester resin-based easy-adhesion layer is applied on one side and subjected to an easy-adhesion treatment. ) Film was used. In addition, as an ultraviolet curable resin composition for the primer layer, 12 parts by mass of an epoxy acrylate prepolymer, 44 parts by mass of a monofunctional monomer composed of phenoxyethyl acrylate, 9 parts by mass of a trifunctional monomer composed of ethylene oxide-modified isocyanuric acid triacrylate, and light What added 3 mass parts of 1-hydroxy- cyclohexyl phenyl ketone (brand name; Irgacure 184, Ciba Specialty Chemicals company make) as an initiator was prepared. The PET film set in the supply unit was fed out, and the ultraviolet curable resin composition was coated on the easy-adhesion treated surface of the PET film to a thickness of 20 μm by a diagonal gravure reverse roll coating method to prepare a transparent substrate.

[Manufacture of electromagnetic shielding materials]
An electromagnetic wave shielding material was manufactured by the apparatus shown in FIG. First, using a gravure plate roll 62 with a plate pattern of 17 μm in line width, 270 μm in pitch, and 12 μm in plate depth, a silver paste ink (which has a substantially spherical shape and has a particle shape) filled in a filling container 68. In a mixed system of particles having a particle size distribution of 0.1 to 0.5 μm and particles having a particle size distribution of 1 to 3 μm, 93 parts by mass of silver particles having an average particle diameter of 2 μm are added to 4 parts by mass of a thermoplastic acrylic binder resin. The plate surface 63 coated with a pick-up roll 61 with a solid content of about 88.5% dispersed and the excess ink scraped off with a doctor blade 65, and a primer for a transparent substrate (PET film) on which a primer layer is formed The layer side is pressure-bonded with a nip roll 66, and subsequently an ultraviolet irradiation zone (not shown, but above the intaglio roll 62 at the site indicated as "UV zone" in FIG. 5). The UV curable resin of the primer layer is cured while traveling between the plate surface, the plate surface 63 is released from the plate surface 63 through the nip roll 67, and the surface of the plate cylinder is formed on the PET film through the primer layer. The conductive material composition 15 formed with the plate pattern was transferred to form a conductive pattern layer 3 ′ composed of mesh-shaped convex portions, and an electromagnetic wave shielding material (transfer film) was produced. The transparent substrate was an endless roll, and was printed by a roll-to-roll method at a printing speed of 10 m / min.
Next, the transition film was passed through a drying zone at 120 ° C. to evaporate and harden the solvent of the silver paste, thereby forming a conductor pattern layer 3 composed of a mesh pattern on the primer layer. The thickness of the conductor pattern layer at this time (thickness difference between the mesh pattern portion on which the conductor pattern layer is formed and the other portion) is 10 μm, and the silver paste in the concave portion of the plate is high. Metastasis was observed at a metastasis rate (83%). Moreover, neither disconnection nor shape defect was seen.
When the sample was cut out from the electromagnetic shielding material that had not been subjected to the electrical resistance reduction treatment and the surface resistivity was measured, it was 1.5Ω / □. Moreover, when what cut | disconnected the wire rod part of the conductor pattern layer 3 of the obtained electromagnetic wave shielding material in the cross section orthogonal to the extension direction was image | photographed with the transmission electron microscope, some adjacent conductor particles 3a Only points where they are in point contact are recognized.

[Electrical resistance reduction treatment]
Subsequently, the electrical resistance reduction process was performed by the following method.
The sample was immersed in an acid treatment tank filled with 25% hydrochloric acid aqueous solution containing 1% by mass of hydrochloric acid for 30 seconds, and then subjected to acid treatment. The sample was taken out of the acid treatment tank and made of pure water having a water temperature of 90 ° C. For 30 seconds, a hot water treatment was performed, and then dried to such an extent that moisture was removed to obtain a sample of an electromagnetic shielding material. The surface resistivity of this electromagnetic wave shielding material was 0.5Ω / □, and a decrease in surface resistivity of about 67% was confirmed. The surface resistivity of the electromagnetic wave shielding material after acid treatment was 0.8Ω / □.
When the wire rod part of the conductor pattern layer 3 of the obtained electromagnetic wave shielding material cut with a cross section perpendicular to the extending direction was photographed with a transmission electron microscope, the relative shape as shown in the SEM cross-sectional photograph of FIG. In particular, the distribution is sparse in the vicinity of the primer layer and dense in the vicinity of the top of the conductive pattern, and some of the adjacent conductive particles 3a have a surface (a line in the cross-sectional photograph). It can be seen that there are many things in contact with. From these, it is determined that the conductor particles 3a are fused together. Then, it can be seen that the left and right slope surfaces of the conductor pattern layer 2 communicate with each other by a series (cluster or agglomeration) of the fused conductor particles 3a.

Next, an optical filter layer of the front composite filter was prepared by a commercial product or by preparation.
[Outside light reflection prevention layer]
As the external light antireflection layer, Realic 1700 (manufactured by NOF Corporation), which is an antiglare low reflection film, was used as the antiglare layer.

[Preparation of micro louver layer]
A liquid mixture of a liquid urethane acrylate-based prepolymer, an acrylate-based monomer, and a benzophenone-based photoinitiator is formed on one surface of a transparent base sheet 200 made of a transparent biaxially stretched PET film having a thickness of 188 μm. A liquid ultraviolet curable resin comprising the following was applied so that the film thickness after curing would be 155 μm. Next, a cross-section that is linearly connected in the circumferential direction along the surface direction of the plate surface, and the cross section orthogonal to the extending direction has a height of 150 μm, the length of the bottom surface side of the plate surface is 30 μm, and the bottom side far from the plate. Between a PET roll and a roll mold formed with a group of convex ridges (same shape as dark ridges) in which a plurality of groove-shaped convex portions having a trapezoidal length of 6 μm are arranged in parallel with each other at a period of 60 μm The ultraviolet curable resin is irradiated with ultraviolet rays from a mercury lamp in a state where the coated ultraviolet curable resin is sandwiched so that the ultraviolet curable resin is cross-linked and cured to form a transparent resin layer, and then the roll mold is released from the transparent resin. A PET film that has a layer surface, a straight line extending in one direction along the surface direction of the transparent resin layer surface, a cross section orthogonal to the extending direction having a height of 150 μm, and the length of the bottom side of the transparent resin layer surface being 30 μm A trapezoid with a base length of 6 μm The transparent resin layer 300 having a surface 凹條 groove group consisting formed on one surface of the transparent substrate 200.
A black liquid material in which black light-absorbing particles are added to the transparent resin is applied to the entire surface of the transparent resin layer 300 including the concave groove group of the transparent resin layer 300 formed by the above-described process. Subsequently, the coating film is squeezed with an iron doctor blade to scrape and remove only the liquid material outside the concave groove, and the liquid material is filled only into the concave groove to form a dark-colored light-absorbing wedge 400. By forming, the micro louver layer CRF (300 + 400) was completed. Further, the angle θ between the inclined surface where the transparent resin layer 42 and the dark-colored convex portion 400 are in contact with the normal line V of the light exit surface was 45 degrees.

(Dye-containing layer)
(1. Production of adhesive film 1 for near infrared and neon light absorption and toning)
Acrylic resin-based pressure-sensitive adhesive (made by Toyo Ink Co., Ltd., pressure-sensitive pressure-sensitive adhesive BPS6212 (solid content 27%)) as a transparent resin, 100 parts by weight, and a solid content ratio of a composition comprising methyl isobutyl ketone as a solvent is 20% (mass In a resin solution dissolved so as to be a reference), 0.03 parts by mass of a diimonium-based near-infrared absorbing dye whose counter ion (X ⁻ ) is a “bistrifluoromethanesulfonyl imido ion” as a monovalent anion , And phthalocyanine-based near-infrared absorbing dye [IR-14: trade name, manufactured by Nippon Shokubai Co., Ltd.] 0.02 parts by mass, [IR-12: trade name, manufactured by Nippon Shokubai Co., Ltd.] 0.05 parts by weight, Three near-infrared absorbing pigments and clay mineral (trade name Kunipia D36); 0.05 part by mass of Kunimine Kogyo Co., Ltd., and tetraazaporphyrin-based Ne light absorbing compound “TAP-2” (trade name, Yamada Chemical Co., Ltd.) 0.01 parts by mass, “Kayaset BlueA-2R” (trade name, manufactured by Nippon Kayaku Co., Ltd.) as a toning pigment in the visible range, and UV absorber (Cytech) 4 parts by mass, CyasorbUV24), 2 parts by mass of a light stabilizer (manufactured by Ciba, TINUBIN 144), 0.015 parts by mass of an antioxidant (1,2,3 benzotriazole, manufactured by Tokyo Chemical Industry Co., Ltd.) Using a coating solution obtained by sufficiently dispersing, it is applied onto a release paper and dried, and then the composition surface is bonded with another release paper, and a near infrared / neon light absorbing and toning adhesive film having a thickness of 100 μm. It was obtained Lum 1.

(2. Near infrared absorption, neon light absorption, toning coating layer 2)
On the opposite side of the anti-glare layer of Realak 1700 (manufactured by NOF Corporation) which is an anti-glare low reflection film, the coating solution used for the near infrared / neon light absorbing and toning adhesive film 1 is applied and dried. A near infrared ray / neon light absorbing and toning coating layer having a thickness of 25 μm was obtained.

(Transparent adhesive layer)
An adhesive having a thickness of 25 μm (manufactured by Yodogawa Paper Co., Ltd., TD-06A) was used as an adhesive for bonding the constituent layers of the composite filter and the transparent substrate side of the electromagnetic wave shielding material.
On the other hand, in Example 2, an adhesive made of an acrylic resin was laminated to flatten the conductor pattern of the electromagnetic wave shielding material layer.

(Production of composite filter for the front of image display device)
Using each functional layer and the pressure-sensitive adhesive layer obtained as described above, a composite filter for the front surface of the image display device was obtained by laminating in a layer structure as shown in FIGS.

(Measurement of reflectance of front composite filter)
A black tape (Yamato vinyl tape, product number: No. 200 black) is affixed to the colorless transparent adhesive layer 700 on the substrate side of the electromagnetic wave shielding material layer of the produced composite filter for the front surface without bubbles, and the spectrometer UV The reflection measurement was carried out by SCE (Spectral Component Exclude) using -3100PC (manufactured by Shimadzu Corp.), using a C light source, setting the incident angle with respect to the normal line of the antireflection layer of the composite filter to 2 °.

(Measurement of reflection color of front composite filter)
In order to express the color tone of the reflection color on the antireflection layer side of the front composite filter with a color system “L ^* , a ^* , b ^* ” in accordance with JIS-Z8729, a spectroscopic color meter CM-600d (Konica Minolta, Inc.) And manufactured by SCE using an F10 light source. In addition to low L ^* (lightness), it is preferable that absolute values of “a ^* ” and “b ^* ” are small (saturation is low) because the composite filter has high non-visibility, and b ^* < It can be evaluated that 0 is stronger and more preferable.

Example 1
As shown in FIG. 12A, from the image display device (PDP) side, a colorless transparent adhesive layer 700, an electromagnetic wave shielding material layer 10, and a near-infrared / neon light absorption and toning dye-containing adhesive that also serves as a planarizing layer. The composite layer was obtained by laminating the agent layer 600, the transparent base material sheet, (the dark wedge PDP side direction) microlouver layer CRF (300 + 400), the colorless and transparent adhesive layer 700, the base material film, and the antireflection layer. In addition, the transparent base material sheet 200 shows the PET sheet used as a transparent base material of an electromagnetic wave shielding layer, a microlouver layer, and an antireflection layer.
Table 1 shows the results of measuring the reflectance (Y) and the reflection color (L *, a *, b *) of the obtained composite filter according to the measurement method described above.

Example 2
As shown in FIG. 12 (B), from the image display device (PDP) side, a colorless and transparent pressure-sensitive adhesive layer, a base material, an electromagnetic wave shielding material layer, a colorless and transparent pressure-sensitive adhesive layer that also serves as a flattening layer, a base material, PDP side direction) A micro louver layer, a colorless transparent adhesive layer, a near infrared ray / neon light absorption and toning coating layer, a substrate, and an antireflection layer were laminated in this order to obtain a composite filter.
Table 1 shows the results of measuring the reflectance (Y) and the reflection color (L *, a *, b *) of the obtained composite filter according to the measurement method described above.

Example 3
As shown in FIG. 12C, from the image display device (PDP) side, a near-infrared / neon light absorbing and toning adhesive that also serves as a colorless and transparent adhesive layer, a base material, an electromagnetic wave shielding material layer, and a flattening layer A composite filter was obtained by laminating a layer (film 1), a base material, a (directed toward the dark wedge observer) micro louver layer, a base material, and an antireflection layer in this order.
Table 1 shows the results of measuring the reflectance (Y) and the reflection color (L *, a *, b *) of the obtained composite filter according to the measurement method described above.

As shown in Table 1, all of the composite filters of the examples of the present invention had extremely low reflectance, and in Examples 1 and 2, the brightness and saturation of the reflected color were also approximated.
On the other hand, in Example 3, the microlouver layer wedge direction and the number of PET base material layers are 2 and the number is less than Examples 1 and 2, the lightness is the lowest, a * is large, and b * is small. Also, the tendency was almost colorless.

In the filter for the front surface of the image display device of the present invention, the reflectance (Y) is preferably 1.3% or less from the viewpoint of visibility of the display and reduction of reflection of the surrounding light source, indoor lighting device, and the like. .
In addition, regarding L *, a *, and b * in the chromaticity coordinates shown in the color system, L * depends on the specifications (transmittance) of the PDP. preferable. Moreover, it is preferable that −10 <a * <10 and −10 <b * <10 in view of the fact that a * and b * are in the following ranges, and redness and yellowness are not preferred. It is.

Since the composite filter for the front surface of the image display device of the present invention has high visible transmittance, low reflectance, and the reflection color of the filter, that is, the chromaticity coordinates of the reflected light, is in a certain range,
It has excellent appearance characteristics, and the contrast does not decrease even when an image display device is used in a place where external light is incident, and the brightness and image quality of the image do not decrease. The electromagnetic wave can be prevented from being emitted to the observer side, and can be effectively used as a composite filter for the front surface of the image display device.
Further, since the chromaticity coordinates of the reflected light change by changing the order of the constituent filters and / or the direction of the microlouver as the contrast improving layer, the hue as seen from the surface (antireflection layer) side of the composite filter The brightness can be appropriately selected according to the use, demand, and performance, and can be effectively used as a composite filter for the front surface of the image display apparatus that can meet various demands.
In addition, since the image display device of the present invention is provided with the composite filter having the above-mentioned features on the front surface, it can be used as an image display device that is excellent in appearance characteristics as a whole and adapted to customer preferences even when not lit. can do.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Primer layer 3 Conductor pattern layer (3 'conductor material composition layer)
DESCRIPTION OF SYMBOLS 4 Metal layer 5 Side edge 6 Recess 7 Electromagnetic wave shielding pattern part 8 Grounding part 9 Protective layer 10 Electromagnetic wave shielding material 15 Conductor material composition 41 Dark particle 42 Transparent resin 43 Groove-shaped recessed part 45 Slope 47 Flat part 50 Translucent area | region 51 Gravure roll 52 Backup roll 53 Resin composition filling container 54 Doctor blade 61 Pickup roll 62 Intaglio roll 63 Plate surface 64 Recess 65 Doctor blade 66 Nip roll 67 Nip roll 68 Filling container 100 Antireflection layer for external light (antireflection layer comprising low refractive index layer) (Or antiglare layer)
200 Transparent substrate sheet 300 Transparent resin layer of micro louver layer 400 Absorbing wedge-shaped portion of micro louver layer 500 Barrier layer 600 Dye-containing pressure-sensitive adhesive layer 700 Colorless transparent pressure-sensitive adhesive layer A A portion where a conductor material layer is formed TA A thickness B A portion where the conductive material layer is not formed TB B thickness Fcom Composite filter Fopt Optical functional layer S1 One surface of the transparent substrate S2 The other surface of the transparent substrate CRF (= 300 + 400) Microlouver layer (Contrast improvement layer)

Claims (2)

When viewed from the observer side, an external light antireflection layer is disposed on the outermost surface, and an electromagnetic wave shielding material layer is disposed on the outermost surface. A composite filter for the front surface of an image display device in which electromagnetic wave shielding layers are laminated in appropriate directions,
(I) The external light antireflection layer comprises an antireflection layer or an antiglare layer comprising a low refractive index layer,
(Ii) The dye-containing layer is a dye having absorption in the near infrared region, a dye having an absorption region in the neon light region, a toning dye having an absorption region in the visible light region other than the neon light region, and absorbing in the ultraviolet region. Comprising at least one light absorbing dye selected from the group consisting of dyes having a region and a resin binder,
(Iii) The microlouver layer has a trapezoidal shape in which a linear cross-sectional shape orthogonal to the extension direction is arranged in parallel on the one surface of the transparent substrate along the in-plane direction of the transparent substrate. A substantially trapezoidal dark color part, and a translucent region between the adjacent dark color parts,
(Iv) The electromagnetic wave shielding material layer includes a transparent substrate, a primer layer formed on the transparent substrate, and a conductor pattern layer formed of a conductor composition formed in a predetermined pattern on the primer layer. The portion of the primer layer where the conductor pattern layer is formed is thicker than the portion where the conductor pattern layer is not formed, and the conductor composition is a conductor. Particles and a binder resin, and the distribution of the conductive particles in the conductive pattern layer is relatively sparse in the vicinity of the primer layer and close to the top of the conductive pattern. is there,
A composite filter for a front surface of an image display device. The composite filter according to claim 1 is disposed on the front surface of the main body of the image display device.
An image display device characterized by that.