JP2007096111A - Composite filter for display and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite filter for display excellent in transparency, and to provide a method for manufacturing a high transparency composite filter inexpensively with a favorable yield by reducing the burden of a facility or an extra material through a short process and preventing bubbles from mixing into a mesh opening. <P>SOLUTION: In the composite filter for display where at least a conductor mesh layer 12 having a mesh-like region, an adhesive layer 22, and an optical filter 21 are formed in this order on one side of a transparent substrate 11, a height at a line in the mesh-like region of the conductor mesh layer 12 is 3 μm or lower, the width of an opening in the mesh-like region is 150 μm or larger, and the adhesive layer 22 is formed of an adhesive having a storage modulus E'(Pa) at 20°C of dynamic viscoelasticity at a frequency of 1 Hz not higher than 9.5×10<SP>5</SP>. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a composite filter for display comprising an electromagnetic wave shielding sheet and an optical filter for shielding (shielding) electromagnetic waves generated from a display such as a CRT and a PDP, and a manufacturing method of the composite filter for display. The present invention relates to a composite filter for a display with less air bubbles and excellent transparency, and a method for producing the composite filter for a display with high productivity.

  In recent years, with the advancement of functions and increased use of electrical and electronic equipment, electromagnetic noise interference (EMI) has increased, and electromagnetic waves are also generated in displays such as cathode ray tubes (referred to as CRT) and plasma display panels (referred to as PDP). appear. A plasma display panel is a combination of a glass having a data electrode, a fluorescent layer, and a glass having a transparent electrode, and generates a large amount of electromagnetic waves, near infrared rays, and heat when operated.

  Usually, an electromagnetic wave shielding sheet is provided as a front plate on the front surface of the plasma display panel in order to shield electromagnetic waves. The shielding property of electromagnetic waves generated from the front surface of the display requires a function of 30 dB or more at 30 MHz to 1 GHz. Furthermore, in order to make the display image easy to see, it is difficult to see the metal mesh (line part) for shielding electromagnetic waves, and the mesh pattern accuracy is good and the mesh is not disturbed. ).

In addition, near infrared rays having a wavelength of 800 to 1,100 nm generated from the front of the display also cause other devices such as VTRs to malfunction, and need to be shielded. Further, there is a case where a function for shielding unnecessary light having a specific wavelength generated from the image display device or providing various functions necessary for the image display device is required.
In order to realize the above functions with as few layer configurations as possible, the electromagnetic wave shielding sheet and an optical filter layer including a near-infrared absorption filter or the like are laminated to generate unnecessary electromagnetic waves and specific wavelengths generated from the image display device. It has been studied to use a composite filter as a front panel of a display panel that can shield various light and can provide various functions required for an image display device.

  Conventionally, as a method for manufacturing an electromagnetic wave shielding sheet having a mesh-like metal layer, a metal foil is bonded to a transparent plastic substrate via an adhesive layer, and then the metal foil is geometrically formed by a chemical etching process (photolithography process). Methods for forming academic figures are known. However, according to this method, although the pattern accuracy of the mesh is good, since different materials are laminated, warping is likely to occur. Further, since the roughness of the metal foil is transferred and remains uneven on the surface of the adhesive at the mesh opening, light is irregularly reflected by the roughness, and the transparency of the mesh opening is poor. There is. Further, in the step of laminating the electromagnetic shielding sheet and the optical filter, since the opening of the electromagnetic shielding sheet is dented, if the optical filter is laminated directly using an adhesive, bubbles are mixed into the mesh opening. The transparency of the composite filter may deteriorate due to light scattering of the bubbles. As long as the method for bonding the metal foil is selected, it is necessary to ensure the film thickness of the metal foil to 10 μm or more in order to maintain the strength that the metal foil does not break in the bonding process. That means that the depth (step) of the mesh opening is 10 μm or more. Therefore, conventionally, in order to fill the roughness of the adhesive surface of the mesh opening and / or to prevent contamination by bubbles and to make the mesh transparent, the mesh opening is previously referred to as a flattening resin. An additional step of filling with resin and providing a planarization layer was necessary. Such a transparentization process requires an extra material and also increases the number of processes, so that it has been desired to omit it.

  On the other hand, research to eliminate the problem of air bubbles mixing by improving the physical properties of the adhesive is also underway. For example, Patent Document 1 discloses an electromagnetic wave shielding film having a geometrical figure drawn with a conductive metal for the purpose of obtaining an adhesive film that sufficiently satisfies electromagnetic wave shielding properties, transparency / non-visibility, adhesiveness and the like simultaneously. There has been proposed an electromagnetic wave shielding adhesive film in which the conductive metal side is coated with an adhesive having a storage elastic modulus of 25 ° C. or more and a specific value at 80 ° C. or less. The adhesive for the electromagnetic wave shielding adhesive film is assumed to be tack-free (non-tacky) for free alignment at room temperature, and the conductive metal side is coated with the adhesive by heating lamination at 80 ° C. Therefore, it is not suitable for lamination by room temperature lamination.

JP 2000-294982 A

  The present invention has been made to solve the above-mentioned problems, and is a composite filter for display having excellent transparency, and in a short process, the burden of equipment and extra material is reduced, and the mesh opening is reduced. An object of the present invention is to provide a method for producing a composite filter that can prevent air bubbles from being mixed and can be obtained at a low cost without being heated to a high temperature with a high transparency composite filter.

As a result of intensive studies to achieve the above object, the present inventor has obtained a composite filter in which a conductive mesh layer having a specific shape and a pressure sensitive adhesive layer formed of a specific pressure sensitive adhesive are laminated. The knowledge that it can be achieved has been found and the present invention has been completed.
That is, the composite filter for display of the present invention is a composite filter for display in which a conductive mesh layer having a mesh region, an adhesive layer, and an optical filter are provided in this order on one surface of a transparent substrate. The height of the line portion of the mesh-like region in the conductor mesh layer is 3 μm or less, the opening width of the opening of the mesh-like region is 150 μm or more, and the adhesive layer is dynamic at a frequency of 1 Hz. The storage elastic modulus E ′ (Pa) at 20 ° C. of viscoelasticity is E ′ ≦ 9.5 × 10 ⁵
It is formed with the adhesive which is.

In the method for producing a composite filter for display according to the present invention, (A) a conductive material having a mesh-like region having a line portion height of 3 μm or less and an aperture width of 150 μm or more on one surface of a transparent substrate. A step of preparing an electromagnetic wave shielding sheet in which at least a body mesh layer is laminated, and (B) a storage elastic modulus E ′ (Pa) at 20 ° C. of dynamic viscoelasticity at a frequency of 1 Hz on one surface of the optical filter. '≦ 9.5 × 10 ⁵
A step of preparing a pressure-sensitive adhesive filter formed by laminating a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive, and (C) the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive optical filter, the conductor mesh of the electromagnetic wave shielding sheet It is characterized by comprising a laminate of an electromagnetic wave shielding sheet and an adhesive optical filter having a step of laminating toward the layer side.

  By using a combination of a mesh area with a specific shape and a specific pressure-sensitive adhesive layer, while eliminating the vacuum suction process such as autoclaving and the laminating process on the mesh surface, and heating during lamination, Since it is possible to prevent air bubbles from being mixed into the openings of the mesh-like region during the lamination and adhesion of the shielding sheet and the optical filter, it is possible to avoid the disadvantage that the haze of the composite filter due to light scattering of the air bubbles increases, A highly transparent composite filter can be obtained with high production efficiency.

  According to the manufacturing method of the present invention, in addition to the above merits, in particular, in the case where the optical filter is laminated only in a region having a specific shape and size centering on the central portion in the mesh-like region of the electromagnetic wave shielding sheet, Compared with a method in which the adhesive layer is applied in advance to the mesh region and then laminated with the optical filter, there is also an advantage that the adhesive layer hardly oozes out of the optical filter attaching region. This is because when the adhesive layer is applied on the mesh-like region, the adhesive is applied to the adhesive region that has been diluted with the solvent to reduce the viscosity. In the case where the adhesive layer is coated on the optical filter, it is inevitable that the adhesive layer is laminated on the mesh region by drying and removing the solvent to increase the viscosity. This is because it becomes difficult for the adhesive to flow out of the sticking part.

  The composite filter for display according to the present invention has excellent transparency and high productivity because there is no mixing of bubbles. In addition, according to the method for manufacturing a composite filter for display of the present invention, it is possible to prevent air bubbles from being mixed even if heating is not performed at a high temperature (for example, 80 ° C.) or more and the burden of equipment and extra materials is reduced in a short process. Therefore, a composite filter with high transparency can be obtained with good yield and at low cost.

The composite filter for display of the present invention is a composite filter for display in which a conductive mesh layer having a mesh-like region, an adhesive layer, and an optical filter are provided in this order at least on one surface of a transparent substrate, The height of the line portion of the mesh region in the conductor mesh layer is 3 μm or less, the opening width of the opening of the mesh region is 150 μm or more, and the adhesive layer has dynamic viscoelasticity at a frequency of 1 Hz. Storage elastic modulus E ′ (Pa) at 20 ° C. of E ′ ≦ 9.5 × 10 ⁵
It is formed with the adhesive which is.

  The composite filter for display according to the present invention includes an electromagnetic wave shielding sheet having a mesh-like conductor layer having a relatively thin thickness and a wide opening width, and an adhesive having a specific storage elastic modulus E ′. By combining the adhesive optical filter having the formed adhesive layer, the adhesive layer spreads to every corner in the opening of the mesh-like conductor layer, and the adhesive layer is difficult to take in bubbles, Even if the pressurized portion is laminated without heating to a high temperature under an atmospheric pressure atmosphere, mixing of bubbles can be suppressed and transparency can be improved.

〔Layer structure〕
FIG. 1 is a cross-sectional view illustrating a basic form of a composite filter for display according to the present invention.
In FIG. 1A, the conductive mesh layer 12 is formed on the transparent base material 11, and the surface of the transparent base material 11 on which the conductive mesh layer 12 is formed and the optical filter 21 are the adhesive layer 22. It is the structure laminated | stacked through. The optical filter 21 is a layer having various filter functions such as a sheet, plate, or coating film, such as a reflection (including antiglare) prevention filter, a near infrared absorption filter, and the like. The optical filter usually also serves as a protective film for the conductor mesh layer. In the present invention, the conductor mesh layer 12 includes a conductive treatment layer 13, a metal layer 14, and other layers having conductivity, which are conductive thin layers serving as a base layer for electrolytic plating. It is.

  FIG. 1B is an example of a layer structure when a composite filter is formed by an electrolytic plating method, and a conductive treatment is applied to the transparent substrate 11 so as to provide conductivity sufficient for electrolytic plating. A layer 13 is formed, a metal layer 14 is further laminated thereon by electrolytic plating, and the surface on which the metal layer 14 is formed on the transparent substrate 11 and the optical filter 21 are interposed via the adhesive layer 22. It is the structure laminated | stacked.

  Further, the composite filter of the present invention may be formed by further laminating a blackening layer and / or a rust preventive layer on the front and back surfaces of the conductor mesh layer as necessary. In order to improve the visibility of the image of the display by reducing the rate and giving a sense of contrast, the composite filter of the present invention has the metal layer 14 and the pressure-sensitive adhesive layer 22 as shown in FIG. A blackened layer may be provided between them.

  FIG. 2 is a perspective view illustrating only the transparent base material layer 11, the conductive treatment layer 13, and the metal layer 14 in the composite filter of FIG. 1C, and is an example of an electromagnetic wave shielding sheet. The conductive treatment layer 13 and the metal layer 14 have a mesh shape in which the openings 103 are densely arranged, and the mesh region 101 is composed of the openings 103 and a line portion 104 that forms a frame. A blackened layer (not shown) provided on the surface of the metal layer 14 is integrated with the conductive treatment layer 13 and the metal layer 14 to form the mesh region 101.

3 is a cross-sectional view taken along line AA and BB in FIG. 3A shows an AA cross section that crosses the opening, and the openings 103 and the lines 104 are alternately formed. FIG. 3B shows a BB cross section that cuts through the line 104, and the metal layer 14 and the conductive treatment. A line portion 104 made of the layer 13 is continuously formed. In addition, all the sectional views of the composite filter shown in FIG. 1 correspond to the AA sectional view.
In addition, the above illustration does not limit the aspect of the composite filter of this invention. Any device that has substantially the same structure as the technical idea described in the claims of the present invention and that exhibits the same effect can be included in the technical scope of the present invention. .

Hereinafter, the composite filter of this invention is demonstrated in order for every layer from a transparent base material.
[Transparent substrate]
The transparent substrate is a layer for reinforcing a copper mesh layer having a low mechanical strength. Therefore, as long as it has light transmittance as well as mechanical strength, it may be selected and used depending on the application, taking into account heat resistance, insulation, etc. as appropriate. Specific examples of the transparent substrate include, for example, plates and sheets (or films; the same applies hereinafter) made of an organic material such as a resin, and plates made of an inorganic material such as glass.

  Examples of transparent resins used as plates and sheets made of the above organic materials include, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, terephthalic acid-isophthalic acid-ethylene glycol copolymer, terephthalic acid-cyclohexanedimethanol-ethylene glycol. Polyester resins such as copolymers, polyamide resins such as nylon 6, polyolefin resins such as polypropylene and polymethylpentene, acrylic resins such as polymethyl methacrylate, styrene resins such as polystyrene and styrene-acrylonitrile copolymers And cellulose resins such as triacetyl cellulose, imide resins, polycarbonate resins and the like.

In addition, these resins are used as a single or a plurality of types of mixed resins (including polymer alloys) as a resin material, and as a layer, they are used as a single layer or a laminate of two or more layers. In the case of a resin sheet, a uniaxially stretched or biaxially stretched sheet is more preferable in terms of mechanical strength.
Moreover, you may add additives, such as a ultraviolet absorber, a filler, a plasticizer, an antistatic agent, in these resins suitably as needed.

Further, as the glass of the glass plate, there are quartz glass, borosilicate glass, soda lime glass, etc. More preferably, the thermal expansion coefficient is small, the dimensional stability and the workability in high-temperature heat treatment are excellent, and the glass contains an alkali. Examples include alkali-free glass that does not contain a component, and can also be used as an electrode substrate that serves as a front substrate of a display.
The thickness of the transparent substrate is not particularly limited as long as it depends on the application. When the transparent substrate is made of a transparent resin, it is usually about 12 to 1000 μm, preferably 50 to 500 μm. On the other hand, when a transparent base material is a glass plate, about 1-5 mm is usually suitable. In any material, when the thickness is less than the above, the mechanical strength is insufficient and warping, loosening, breakage, and the like occur. When the thickness exceeds the above, the cost is increased due to excessive performance and it is difficult to reduce the thickness.

In addition, the transparent base material may also be used as a front substrate, which is a component of the display main body including the front substrate and the rear substrate, but in the form using an electromagnetic wave shielding filter as a front filter disposed in front of the front substrate. The sheet is superior to the plate in terms of thinness and lightness, and the resin sheet is superior to the glass plate in that it is not broken.
In this respect, a resin sheet is a preferable material for the transparent substrate, but among the resin sheets, in particular, polyester resin sheets such as polyethylene terephthalate and polyethylene naphthalate have transparency, heat resistance, cost, and the like. In view of this, a biaxially stretched polyethylene terephthalate sheet is more preferable. In addition, although the transparency of a transparent base material is so good that it is high, Preferably the light transmittance which becomes 80% or more by visible light transmittance | permeability is good.

[Conductor mesh layer]
The conductor mesh layer is a layer having conductivity and is responsible for the electromagnetic wave shielding function, and is itself opaque but has an electromagnetic wave shielding performance due to the presence of an opening in a mesh shape. And light transmission.
For the conductor mesh layer, in addition to the metal layer, for example, a conductive layer serving as a base layer for the metal layer, which is necessary when the metal layer is formed by an electrolytic plating method that facilitates the formation of a thin metal layer of less than 10 μm. And a thin layer (conductive treatment layer) having conductivity, a blackening layer and / or a rust prevention layer having conductivity, and the like. For example, in FIG. 1C, when the blackened layer 15 has conductivity, the conductive mesh layer includes the conductive treatment layer 13, the metal layer 14, and the blackened layer 15. On the other hand, when the blackening layer 15 does not have conductivity, the conductive mesh layer includes only the conductive treatment layer 13 and the metal layer 14.

  The shape in plan view of the conductor mesh layer is not particularly limited, but a square is typical as the shape of the opening. Examples of the shape of the opening include a triangle such as a regular triangle, a square such as a square, a rectangle, a rhombus, and a trapezoid, a polygon such as a hexagon, a circle, and an ellipse. The mesh has a plurality of openings having these shapes, and the openings are usually line-like line portions having a uniform width, and the openings and the openings are generally the same shape and the same size on the entire surface. For example, the width of the line portion 104 between the openings, that is, the line width W is preferably 25 μm or less, and preferably 20 μm or less, in view of the aperture ratio and the invisibility of the mesh. However, it is preferable to secure at least 5 μm or more for the expression of the electromagnetic wave shielding effect and prevention of breakage. The opening width of the opening is represented by (line pitch P) − (line width W). In the present invention, the width is 150 μm or more, preferably 200 μm or more. From the point that air bubbles hardly remain in the opening during lamination. However, in order to exhibit electromagnetic wave shielding properties in the MHz to GHz band, the maximum is 3000 μm or less.

  In the present invention, the thickness of the finally obtained mesh region of the conductor mesh layer, that is, the height H of the line portion 104 between the openings is set to 3 μm or less. In such a case, it is a case where the flattening step of filling the mesh openings with a transparent resin called a flattening resin in advance and laminating the flattening layer before lamination with the adhesive optical filter layer is omitted. This is also because the pressure-sensitive adhesive layer easily enters the openings of the mesh-shaped region at the time of laminating and bonding the mesh-shaped region and the pressure-sensitive adhesive layer, and bubbles do not easily remain in the openings. In this case, it is possible to avoid the disadvantage that the haze of the composite filter is increased due to light scattering of the bubbles, and a highly transparent composite filter for display can be obtained with high production efficiency. However, if the thickness of the conductor mesh layer is too thin, the electric resistance value of the metal increases and the electromagnetic wave shielding effect is likely to be impaired. Considering the electromagnetic shielding function, when the opening shape of the mesh region is in the above range, the thickness of the mesh layer needs to be 1 μm or more. Therefore, it is more preferable that the height of the line portion of the mesh region is 1 to 3 μm. If the height of the line portion of the mesh region is less than this, the electric resistance value of the metal is increased and the electromagnetic wave shielding effect tends to be impaired. The level difference of the part becomes large, and bubbles tend to remain when the adhesive layer is laminated.

  In addition, the height of the line part of a mesh-like area | region is all the thickness of the layer which forms the opening part and forms the line part 104 among the conductor mesh layers 12 and the layer which is not further laminated | stacked. Total thickness including. In addition, the bias angle of the mesh region (angle formed between the mesh line portion and the outer periphery of the electromagnetic wave shielding sheet) may be appropriately set to an angle at which moire is difficult to occur in consideration of the pixel pitch of the display and the light emission characteristics. .

(Conductive treatment layer)
The conductive treatment layer is preferably a thin film of a known conductive material, and is made of a metal such as gold, silver, copper, iron, nickel, chromium, or an alloy of these metals. Moreover, transparent metal oxides, such as a tin oxide, ITO, and ATO, may be sufficient. The conductive treatment layer may be a single layer or a multilayer. The thickness of the conductive treatment layer is preferably an extremely thin layer of about 0.001 to 1 μm, as long as necessary conductivity can be obtained at the time of plating.

(Metal layer)
As a material of the metal layer 14, for example, a metal having sufficient conductivity to shield electromagnetic waves, such as gold, silver, copper, iron, nickel, chromium, or an alloy containing these metals can be applied. The metal layer 14 may be a single layer or multiple layers. In the present invention, as described above, the thickness of the metal layer 14 is preferably about 1 to 2 μm in order to set the height of the line portion of the mesh region to 1 to 3 μm.
A blackened layer and / or a rust preventive layer may be further laminated on the front and back surfaces of the conductor mesh layer as necessary. These are included in the conductor mesh layer when having conductivity, but form a mesh-like region integrally with the conductor layer regardless of the presence or absence of conductivity.

(Blackening layer)
In order to absorb the external light to the electromagnetic wave shielding sheet and improve the visibility of the display image, the composite filter of the present invention is provided with a blackening layer between the metal layer and the adhesive layer. It is preferable from the viewpoint of improving the contrast.
In some blackened layers, the surface of the layer becomes rough and adhesion can be enhanced.
The blackening layer may be any layer that exhibits a dark color such as black, and may be any layer that satisfies basic physical properties such as adhesion, and a known blackening layer may be appropriately employed. Further, it does not matter whether the blackened layer has conductivity.

Therefore, as the blackening layer, an inorganic material such as a metal, an organic material such as a black colored resin, or the like can be used. For example, as the inorganic material, a metal compound such as a metal, an alloy, a metal oxide, or a metal sulfide is used. It is formed as a metal-based layer. As a method for forming the metal layer, various conventionally known blackening methods can be appropriately employed. Especially, the blackening process by a plating method is preferable at adhesiveness, uniformity, ease, etc. As a material for the plating method, for example, a metal such as copper, cobalt, nickel, zinc, molybdenum, tin, or chromium, a metal compound, or the like is used. These are superior to the case of cadmium or the like in terms of adhesion and blackness.
Moreover, as a blackening layer, black chrome, black nickel, a nickel alloy, etc. are preferable, and as this nickel alloy, they are a nickel-zinc alloy, a nickel-tin alloy, and a nickel-tin-copper alloy. In particular, the nickel alloy has a good degree of blackness and conductivity, can also impart a rust prevention function to the blackened layer (becomes a blackened layer and a rustproof layer), and can omit the rustproof layer. In addition, since the particles of the blackened layer are usually needle-like, the appearance is likely to change due to external force, but the blackened layer made of nickel alloy is difficult to deform and the appearance is difficult to change in the post-processing step. Benefits.

  A preferable black density of the blackened layer is 0.6 or more. In addition, the measurement method of black density was set to the density standard ANSIT as an observation viewing angle of 10 degrees, an observation light source D50, and an illumination type using GRETAG SPM100-11 (trade name, manufactured by Kimoto Co., Ltd.) of COLOR CONTROL SYSTEM. The specimen is measured after calibration. Further, the light reflectance of the blackened layer is preferably 5% or less. The light reflectance is measured using a haze meter HM150 (trade name, manufactured by Murakami Color Co., Ltd.) in accordance with JIS-K7105. In addition, instead of measuring the reflectance, the Y value of reflection may be expressed by a color difference meter. In this case, the Y value is preferably 10 or less.

(Rust prevention layer)
Furthermore, when the blackened layer is provided so as to cover at least one side of the metal layer 14, the rust preventive layers 16A and / or 16B are provided so as to cover at least one side of the blackened layers 15A and / or 15B. Can be provided.
The rust prevention layers 16A and 16B are preferably provided at least on the blackening layer in order to prevent the rust prevention function and the blackening layer from dropping or deforming. As the rust prevention layer 16B, nickel, zinc, and / or copper oxide, or a chromate treatment layer can be applied. As thickness, it is about 0.001-1 micrometer, Preferably it is 0.001-0.1 micrometer.

  The blackening layers 15A and 15B and the rust prevention layers 16A and 16B may be provided at least on the observation side, and the contrast is improved and the visibility of the image on the display is improved. Further, it may be provided on the other surface, that is, on the display surface side, and stray light generated from the display can be suppressed, so that the visibility of the image is further improved.

[Adhesive layer]
The adhesive layer according to the present invention has a storage elastic modulus E ′ (Pa) at 20 ° C. of dynamic viscoelasticity at an excitation frequency of 1 Hz. E ′ ≦ 9.5 × 10 ⁵
It is formed with the adhesive which is.
When the storage elastic modulus of the pressure-sensitive adhesive used is within the above range, it is possible to prevent bubbles from entering the openings of the mesh-like region of the conductor mesh layer. The inconvenience that the value (haze) increases can be avoided, and a highly transparent composite filter can be obtained. When the storage elastic modulus exceeds the above range, bubbles are likely to be mixed and transparency may be insufficient.

  Here, the storage elastic modulus E 'is an index that can be obtained by a general dynamic viscoelasticity measurement and that indicates the difficulty of deformation strain due to external stress of the sample or the magnitude of the restoring force at the time of strain deformation. The storage elastic modulus E ′ can be obtained by the following method, for example. After rolling the pressure-sensitive adhesive into a spherical shape having a diameter of 5 mm, a dynamic viscoelasticity measuring device (manufactured by Rheometric Scientific, trade name “Solid Viscoelasticity Analyzer RSA-II”) , Measurement attachment; using a parallel plate fixture (RSA-SL-PP4.75HT), a dynamic viscoelasticity measurement is performed under the control of a measurement frequency of 1 Hz, a measurement temperature of 10 to 30 ° C., and a heating rate of 5 ° C./min. The storage elastic modulus E ′ (Pa) at 20 ° C. can be determined.

(Adhesive)
The pressure-sensitive adhesive used in the present invention refers to one type of adhesive. Among the adhesives, the adhesiveness of the surface can be obtained only by pressing moderately, usually lightly by hand, at the time of bonding. It can only be bonded. In order to develop the adhesive strength of the pressure-sensitive adhesive, usually, physical energy or action such as heating, humidification, radiation (ultraviolet ray, electron beam, etc.) irradiation is unnecessary, and chemical reaction such as polymerization reaction is also unnecessary. In addition, the pressure-sensitive adhesive can maintain the adhesive strength to the extent that it can be re-peeled after bonding. There are no particular limitations on such an adhesive, and among those commonly used as known adhesives, appropriate adhesiveness (adhesive force), transparency, and coating suitability as well as the above specific storage elastic modulus. And those that do not substantially change the transmission spectrum of the optical filter used in the present invention.

  The pressure-sensitive adhesive according to the present invention is sufficient if the storage elastic modulus at 20 ° C. satisfies the above range, and the weight of the pressure-sensitive adhesive itself in a natural rubber or a synthetic resin or a polymerization reactive monomer having the above storage elastic modulus at 20 ° C. A syrup-type pressure-sensitive adhesive in which the coalescence is dissolved may be used. It may be a pressure-sensitive adhesive containing a polymerization reactive monomer having the above storage elastic modulus at 20 ° C. and may be cured by light and / or heat after lamination.

  An acrylic adhesive is mentioned as an adhesive suitably used. The acrylic pressure-sensitive adhesive is a polymer containing at least a (meth) acrylic acid alkyl ester monomer. Generally, it is a copolymer of a (meth) acrylic acid alkyl ester monomer having an alkyl group having about 1 to 18 carbon atoms and a monomer having a carboxyl group. In the present invention, (meth) acrylic acid refers to acrylic acid and / or methacrylic acid.

Examples of (meth) acrylic acid alkyl ester monomers used here include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, sec-propyl (meth) acrylate, N-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, Examples thereof include n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, undecyl (meth) acrylate, and lauryl (meth) acrylate.
Moreover, the said (meth) acrylic-acid alkylester is copolymerized in the quantity of 30-99.5 weight part normally in an acrylic adhesive.
Moreover, as a monomer which has a carboxyl group which forms an acrylic adhesive, monomers containing a carboxyl group such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, monobutyl maleate and β-carboxyethyl acrylate are used. Can be mentioned.

  Furthermore, in addition to the above, the acrylic pressure-sensitive adhesive used in the present invention may be copolymerized with a monomer having another functional group within a range that does not impair the characteristics of the acrylic pressure-sensitive adhesive. Examples of monomers having other functional groups include monomers containing hydroxyl groups such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and allyl alcohol; (meth) acrylamide, N-methyl Monomers containing amide groups such as (meth) acrylamide and N-ethyl (meth) acrylamide; Monomers containing amide groups and methylol groups such as N-methylol (meth) acrylamide and dimethylol (meth) acrylamide; Monomers having functional groups such as monomers containing amino groups such as (meth) acrylate, dimethylaminoethyl (meth) acrylate and vinylpyridine; epoxy group-containing monomers such as allyl glycidyl ether and (meth) acrylic acid glycidyl ether Can be mentioned. In addition to these, fluorine-substituted (meth) acrylic acid alkyl ester, (meth) acrylonitrile, and the like, vinyl group-containing aromatic compounds such as styrene and methylstyrene, vinyl acetate, and vinyl halide compounds can be used.

  Furthermore, in the acrylic pressure-sensitive adhesive used in the present invention, in addition to the monomer having other functional groups as described above, another monomer having an ethylenic double bond can be used. Examples of monomers having an ethylenic double bond include diesters of α, β-unsaturated dibasic acids such as dibutyl maleate, dioctyl maleate and dibutyl fumarate; vinyl esters such as vinyl acetate and vinyl propionate. Vinyl ether; vinyl aromatic compounds such as styrene, α-methylstyrene and vinyl toluene; (meth) acrylonitrile and the like.

  In addition to the monomer having an ethylenic double bond as described above, a compound having two or more ethylenic double bonds may be used in combination. Examples of such compounds include divinylbenzene, diallyl malate, diallyl phthalate, ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, methylene bis (meth) acrylamide, and the like.

  Furthermore, in addition to the above-described monomers, monomers having an alkoxyalkyl chain can be used. Examples of alkoxyalkyl esters of (meth) acrylic acid include 2-methoxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, 2-methoxypropyl (meth) acrylate, 3-methoxypropyl (meth) acrylate , 2-Methoxybutyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 4-ethoxybutyl (meth) acrylate And so on.

Moreover, the homopolymer of a (meth) acrylic-acid alkylester monomer may be sufficient. For example, (meth) acrylic acid ester homopolymers include poly (meth) acrylate methyl, poly (meth) ethyl acrylate, poly (meth) acrylate propyl, poly (meth) acrylate butyl, poly (meth) Examples include octyl acrylate.
As a copolymer containing 2 or more types of acrylate units, methyl (meth) acrylate- (meth) ethyl acrylate copolymer, (meth) methyl acrylate- (meth) butyl acrylate copolymer, ( Examples include methyl (meth) acrylate- (meth) acrylic acid 2-hydroxyethyl copolymer, methyl (meth) acrylate- (meth) acrylic acid 2-hydroxy-3-phenyloxypropyl copolymer, and the like.
As a copolymer of (meth) acrylic acid ester and other functional monomers, (meth) methyl acrylate-styrene copolymer, (meth) methyl acrylate-ethylene copolymer, (meth) acrylic An acid methyl- (meth) acrylic acid 2-hydroxyethyl-styrene copolymer may be mentioned.

As the rubber-based adhesive, the main component is, for example, natural rubber, polyisoprene rubber, polyisobutylene, polybutadiene rubber, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, etc. Those containing at least one selected are used.
As a commercial item of the pressure-sensitive adhesive of the present invention, for example, trade name: TU-41A modified (manufactured by Yodogawa Paper Mill), trade name: PD-S1 (manufactured by Panac), etc. are preferably used.

Moreover, it is preferable to mix | blend antioxidant with an adhesive layer. It is possible to prevent the color change from occurring due to oxidation of the conductor layer by the acid component contained in the adhesive at the interface between the pressure-sensitive adhesive layer and the conductor mesh layer of the obtained composite filter.
Furthermore, a tackifier, a silane coupling agent, a filler, etc. can be mix | blended with an adhesive layer as needed.

  Further, the pressure-sensitive adhesive layer may contain one or more near-infrared absorbing dyes, ultraviolet absorbers, and / or neon light absorbing dyes as described below. By doing in this way, the function of a plurality of filters (layers) can be combined with one layer, and this can also be integrated with the adhesive layer, thereby reducing the total thickness, the number of processes, and the cost of the composite filter. Is possible and preferable. In that case, in order to provide the near-infrared absorption filter function, the light transmittance in the wavelength region of 800 nm to 1100 nm is 20% or less, especially 10% or less. In order to provide the neon light absorption filter function, 560 to 630 nm. The light transmittance in the wavelength region is preferably 30% or less, more preferably 25% or less. Moreover, in order to provide an ultraviolet absorption filter function, the light transmittance in a wavelength region of 380 nm or less is preferably 10% or less.

  In this invention, it is preferable that the film thickness of such an adhesive layer exists in the range of 5-40 micrometers. This is because, by setting this range, it is possible to satisfactorily flatten the unevenness of the mesh in the electromagnetic wave shielding sheet, particularly when the electromagnetic wave shielding sheet and the optical filter are laminated and bonded. More preferably, it is 10-30 micrometers.

[Optical filter]
The optical filter constituting the composite filter for display according to the present invention is composed of layers having various filter functions such as a sheet, plate, or coating film, such as a reflection (including antiglare) prevention filter and a near infrared absorption filter. .
The optical filter is not particularly limited, and examples thereof include a near infrared absorption filter, a neon light absorption filter, an ultraviolet absorption filter, an antireflection filter, and an antiglare filter. The optical filter may be one layer or two or more layers, and each layer may have a plurality of different filter functions.

Depending on the manufacturing method of the composite filter for display, the layer configuration of the optical filter may be a single layer, or a transparent substrate may be used as a support substrate, and a layer having a filter function may be laminated thereon, There may be a configuration in which a layer having a filter function and a transparent substrate are laminated to each other.
An adhesive layer may be provided between the filters. Each of the transparent substrate and the pressure-sensitive adhesive layer may be a single layer or a multilayer.

  As the near-infrared absorbing filter, a commercially available film having a near-infrared absorber (for example, Toyobo Co., Ltd., trade name No. 2832) is used, or a composition containing a near-infrared absorbing dye in a binder is formed, or The composition may be applied and laminated on a transparent substrate. As a near-infrared absorbing dye, when an optical filter is applied to the front surface of a plasma display panel, it absorbs a near-infrared region caused by a xenon gas discharge emitted by the plasma display panel, that is, a wavelength region of 800 nm to 1100 nm. Is used. The near-infrared transmittance of the band is preferably 20% or less, more preferably 10% or less. At the same time, it is desirable that the near-infrared absorbing filter has a sufficient light transmittance in the visible light region, that is, in the wavelength region of 380 nm to 780 nm.

  Specific examples of near-infrared absorbing dyes include polymethine compounds, cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, naphthoquinone compounds, anthraquinone compounds, dithiol compounds, imonium compounds, diimonium compounds, and aminium. Compounds, pyrylium compounds, cerium compounds, squarylium compounds, copper complexes, nickel complexes, dithiol metal complexes organic near infrared absorbing dyes, tin oxide, indium oxide, magnesium oxide, titanium oxide, chromium oxide Zirconium oxide, nickel oxide, aluminum oxide, zinc oxide, iron oxide, ammonium oxide, lead oxide, bismuth oxide, inorganic near-infrared absorbing dyes such as lanthanum oxide, etc. can be used alone or in combination of two or more. . As the binder resin, a resin such as a polyester resin, a polyurethane resin, an acrylic resin, or an epoxy resin is used. Binder resin drying and curing methods include a drying and solidification method by drying a solvent (or dispersion medium) from a solution (or emulsion), a polymerization method using heat, ultraviolet light, electron beam energy, and a crosslinking reaction. Alternatively, a curing method utilizing a reaction such as crosslinking or polymerization between a functional group such as a hydroxyl group or an epoxy group in a resin and an isocyanate group in a curing agent can be applied.

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

  Moreover, as an ultraviolet absorption filter, it can form by disperse | distributing an ultraviolet absorber to binder resin, for example. Examples of the ultraviolet absorber include organic compounds such as benzotriazole and benzophenone, and inorganic compounds composed of particulate zinc oxide, cerium oxide, and the like. As the binder resin, resins such as those listed above for the near infrared absorption filter can be used.

Moreover, as an antireflection (AR) filter, for example, a multi-layer structure in which low refractive index layers and high refractive index layers are alternately laminated is generally used, and a dry method such as vapor deposition or sputtering, or coating is used. The wet method can also be used. Note that silicon oxide, magnesium fluoride, fluorine-containing resin, or the like is used for the low refractive index layer, and titanium oxide, zinc sulfide, zirconium oxide, niobium oxide, or the like is used for the high refractive index layer.
In addition, anti-glare (AG) filters can be applied to the surface of the layer by forming a coating using an inorganic filler such as silica in a resin binder, or by shaping using a shaping sheet or shaping plate. It can be formed as a layer provided with fine irregularities that diffusely reflect. 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 described below because surface strength is desired as the surface layer.

In addition, you may laminate | stack the protective film for protecting these layers from an abrasion and contamination on the surface of a conductor mesh layer and an optical filter layer as needed. Examples of the protective film include a hard coat layer (HC layer) and an antifouling layer.
Among the protective films, as the hard coat layer, for example, a polyfunctional (meth) acrylate prepolymer such as polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, or trimethylolpropane tri (meth) Ionization in which trifunctional or higher polyfunctional (meth) acrylate monomers such as acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. are used alone or in combination of two or more selected from these It can be formed as a coating film using a radiation curable resin. Here, (meth) acrylate is a composite notation meaning acrylate or methacrylate.

Of the protective films, the antifouling layer is generally a water-repellent or oil-repellent coat, and a siloxane-based or fluorinated alkylsilyl compound can be applied. A fluorine-based or silicone-based resin used as a water-repellent paint can be preferably used. For example, when the low refractive index layer of the antireflection filter is formed of SiO ₂ , a fluorosilicate water-repellent paint is preferably used.
In addition, the material used with the electromagnetic wave shielding sheet mentioned above can be used suitably for the transparent base material and adhesive layer which comprise an optical filter.

Next, the manufacturing method of the composite filter for displays which concerns on this invention is demonstrated.
In the method for producing a composite filter for display according to the present invention, (A) a conductor having a mesh-like region having a line portion height of 3 μm or less and an opening width of 150 μm or more on one surface of a transparent substrate. A step of preparing an electromagnetic wave shielding sheet in which at least a mesh layer is laminated; and (B) a storage elastic modulus E ′ (Pa) at 20 ° C. of dynamic viscoelasticity at a frequency of 1 Hz on one surface of the optical filter. ≦ 9.5 × 10 ⁵
A step of preparing a pressure-sensitive adhesive filter formed by laminating a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive, and (C) the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive optical filter, the conductor mesh of the electromagnetic wave shielding sheet It is characterized by comprising a laminate of an electromagnetic wave shielding sheet and an adhesive optical filter having a step of laminating toward the layer side.

<(A) Step of preparing an electromagnetic wave shielding sheet>
First, an electromagnetic wave shielding sheet is prepared in which a conductive mesh layer having a mesh-like region having a line portion height of 3 μm or less and an opening width of 150 μm or more is laminated on one surface of a transparent substrate. .

First, a transparent substrate is prepared. As a transparent base material, it can select and use from the base material mentioned above.
When the transparent base material is a resin base material, it can be handled in the form of a continuous belt-like sheet at least at the initial stage of production, such as mesh layer formation, in that the electromagnetic shielding filter can be continuously manufactured to improve productivity. Is preferred.
The transparent substrate is appropriately subjected to known easy adhesion treatment such as corona discharge treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, pre-heat treatment, dust removal treatment, vapor deposition treatment, alkali treatment, etc. May be.

  Next, a conductor mesh layer is formed on the transparent substrate. In the present invention, the formation method of the conductor mesh layer is not particularly limited, and various formation methods in a conventionally known light-transmitting composite filter can be appropriately employed. In the present invention, in particular, it is possible to obtain a desired thin mesh thickness in the present invention, and it is possible to manufacture a thin metal film on one surface of a transparent substrate because it can be manufactured in a short process with good yield and low cost. A transparent substrate on which a metal layer is formed as a metal layer by electrolytic plating is prepared, and the metal layer and the conductive layer on the metal-plated transparent substrate are photo-coated. It is particularly preferable to use a method of forming a mesh by lithography (for example, Japanese Patent No. 3502979, Japanese Patent Application Laid-Open No. 2004-241761). According to this method, a composite filter having excellent transparency and mesh accuracy can be obtained. Therefore, a method for preparing an electromagnetic wave shielding sheet having a mesh region by the above method will be described in detail.

  Conductive treatment is performed on the transparent substrate as described above prior to metal electroplating, which will be described later, to form a conductive treatment layer. As a method for the conductive treatment, a thin film of the above-described known conductive material may be formed. The conductive treatment may be a single layer or multiple layers, and these materials are formed by a known method such as vacuum deposition, sputtering, or electroless plating to form a conductive treatment layer.

  Next, a metal layer is formed on the surface of the conductive treatment layer by electrolytic plating. As the material for the metal layer, a metal having conductivity sufficient to shield electromagnetic waves as described above, or an alloy containing these metals can be used. The metal layer may be a single layer or a multilayer, and copper or a copper alloy is preferable from the viewpoint of ease of electrolytic plating and conductivity. Moreover, when providing an electroconductive blackening layer and / or a chromate (treatment) layer, copper or a copper alloy is preferable also from the adhesive force of a metal layer, a blackening layer, or a chromate layer.

  Further, as shown in FIG. 4A, blackening layers 15A and / or 15B are provided on the front surface, back surface, or both front and back surfaces of the metal layer 14 as necessary. The blackening layer is performed by either roughening the surface of the metal layer 14, providing light absorption over the entire visible light spectrum (blackening), or using both in combination. Further, when the blackened layer 15A is provided on the surface of the transparent substrate 11, the metal layer 14 may be provided after conducting the conductive treatment on the transparent substrate and providing the black plating layer.

As the blackening layers 15A and 15B, formation of metal oxides and metal sulfides and various methods can be applied. In the case of iron, it is usually exposed to steam at a temperature of about 450 to 470 ° C. for 10 to 20 minutes to form an oxide film (blackened film) of about 1 to 2 μm. An oxide film (blackened film) may be used. Further, in the case of copper, cathodic electrodeposition in which the cathode particles are attached by performing cathodic electrolysis in an electrolytic solution composed of sulfuric acid, copper sulfate, cobalt sulfate, and the like is preferable. By providing the cationic particles, the surface becomes more rough, and at the same time, black is obtained. As the cationic particles, copper particles and alloy particles of copper and other metals can be used, but copper-cobalt alloy particles are preferred. The average particle diameter of the cationic particles is preferably about 0.1 to 1 μm from the viewpoint of black density. The cathodic electrodeposition method is also preferable in that the average particle size of the cationic particles to be adhered is adjusted to 0.1 to 1 μm.
When a nickel alloy is used as the material for the blackened layer, the blackened layer may be formed by a known electrolytic or electroless plating method, and the nickel alloy may be formed after nickel plating.

Furthermore, when the rust prevention layer 16B is provided on the blackening layer 15B, a known plating method is used to form an oxide of nickel, zinc and / or copper applied as a material of the rust prevention layer 16B. Further, when the rust preventive layer 16A is provided on the blackened layer 15A surface of the transparent substrate 11, the conductive treatment is performed on the transparent substrate, and the rust preventive layer 16A is provided by the same material and method as the above 16B. Just do it. In this case, a black plating layer (corresponding to the blackening layer 15A), the metal layer 14, and, if necessary, a blackening layer 15B and a rust prevention layer 16B are sequentially provided on the surface of the rust prevention layer 16A.
From the above, as shown in FIG. 4A, a laminate 2 is obtained in which the conductive treatment layer 13, the metal layer 14, the blackening layer 15, and the rust prevention layer 16 are provided on the transparent substrate.

Next, the process of making the conductor layer on the transparent substrate provided as described above into a mesh by a photolithography method will be described.
First, a resist layer is provided in a mesh pattern on the conductive layer on the transparent substrate prepared as described above, for example, the surface of the metal layer 14 on the transparent substrate, and the portion of the metal layer 14 that is not covered with the resist layer. After the etching is removed by etching, a mesh-like metal layer is formed by a so-called photolithography method in which the resist layer is removed. Note that, in that case, in addition to the conductor layer, when other layers having no conductivity are stacked, the other layers are also etched away together with the conductor layer in a region corresponding to the opening.

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

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

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

Etching is performed after masking. As the etching solution used for the etching, an aqueous solution of ferric chloride or cupric chloride that can be easily circulated is preferable in the present invention in which etching is continuously performed. The etching is basically the same as the equipment and process for manufacturing a shadow mask for a color TV cathode ray tube that etches a strip-like continuous steel material, particularly a thin plate having a thickness of 20 to 80 μm. Single-wafer processing in the case of using glass as the transparent substrate 11 has also been performed for a long time. After etching, the substrate may be dried after washing with water, stripping the resist with an alkaline solution, and washing. In this way, the transparent substrate is exposed at the mesh opening.
As described above, the electromagnetic wave shielding sheet 3 as shown in FIG.

<(B) Step of preparing an adhesive optical filter>
Next, on one surface of the optical filter, the storage elastic modulus E ′ (Pa) at 20 ° C. of dynamic viscoelasticity at a frequency of 1 Hz is E ′ ≦ 9.5 × 10 ^5.
An adhesive optical filter in which an adhesive layer formed of an adhesive is laminated is prepared. FIG. 5 shows a cross-sectional view of an example of the adhesive optical filter 4 used in the present invention.

  The optical filter 21 according to the present invention is a filter having one or more functions such as an antireflection filter and a near-infrared absorption filter as described above, and is composed of one or more layers. These can be prepared by a conventionally known method. The shape of the optical filter may be a continuous belt shape or a single wafer shape depending on the method of laminating with the electromagnetic wave shielding sheet.

  The pressure-sensitive adhesive layer 22 is obtained by applying a coating solution for forming a pressure-sensitive adhesive layer obtained by adding an additive or a pigment as necessary to the pressure-sensitive adhesive having the specific storage elastic modulus E ′, and further adding a solvent as necessary. A known layer forming method, for example, a coating method such as roll coating, comma coating, die coating, or gravure coating, or a printing method such as screen printing or gravure printing that allows easy partial formation of an arbitrary shape on at least one surface of 21 Can be formed as appropriate, or can be formed by preparing a sheet-like pressure-sensitive adhesive and laminating it with an optical filter. The optical filter after the adhesive processing is preferably protected with a known separator or the like if necessary. As the separator, a resin sheet such as a biaxially stretched polyethylene terephthalate film whose surface is release-treated with silicone or the like may be used.

<(C) Step of Laminating Electromagnetic Wave Shielding Sheet and Adhesive Optical Filter>
Finally, the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive optical filter is laminated toward the conductor mesh layer side of the electromagnetic wave shielding sheet to obtain the composite filter for display of the present invention.
FIG. 6 is a schematic view for obtaining a composite filter for display by laminating an electromagnetic wave shielding sheet and an adhesive optical filter used in the present invention.
6A, the adhesive layer 22 side having the specific storage elastic modulus E ′ of the adhesive optical filter 4 is placed on the electromagnetic wave shielding sheet 3 as shown in FIG. The composite filter 1 as shown in FIG. 6B can be obtained by arranging the layers so as to face the mesh region 101 and laminating them.

  A method for producing a composite filter by adhering and laminating the pressure-sensitive adhesive layer 22 laminated on the optical filter 21 and the mesh-like region of the electromagnetic wave shielding sheet to produce a composite filter is not particularly limited, but includes a pressure part such as a pressure roll. The method of making it adhere | attach and laminate | stack by pressing simultaneously from the transparent base material 11 side and the optical filter 21 side using a laminator is mentioned. In the present invention, in order to laminate the mesh region having the specific dimensions as described above and the pressure-sensitive adhesive layer formed of the specific pressure-sensitive adhesive as described above, the pressurizing portion is placed under an atmospheric pressure atmosphere. In particular, it is possible to prevent bubbles from being mixed even if the layers are stacked at room temperature without heating. According to the present invention, even when heating, it is sufficient to heat a roll or the like to about 60 ° C., and particularly vacuum suction from the pressure-sensitive adhesive layer side or high-temperature heating at 80 ° C. or higher is unnecessary. . In any case, according to the present invention, there is no need to use special equipment such as autoclave treatment, the equipment burden can be reduced in a short process, and treatment for eliminating mixed bubbles is also unnecessary. . Of course, there is no need to add a process using an extra material such as a transparent treatment.

  However, depending on the case, it is often the case that the heating is also used at a higher speed, more reliably preventing air bubbles from being mixed, so that lamination is possible. It does not hinder the application of the flattening process.

Further, an example in which the layers are laminated further shows that the adhesive layer side of the resin sheet for the continuous band-shaped optical filter and the conductor layer side of the continuous band-shaped electromagnetic wave shielding sheet in which the mesh-shaped region is formed are The method of laminating using a roll type laminator by a roll method is mentioned.
Lamination method using roll-to-roll method is preferable because of its high production efficiency and low cost. However, either one or both of the electromagnetic wave shielding sheet and the adhesive optical filter are made into a single wafer shape and laminated using various laminators. May be.

The laminator may be a roll type, a flat plate type, etc., as long as it can pressurize the electromagnetic wave shielding sheet and the adhesive optical filter, but corresponds to the roll-to-roll method and prevents air bubbles from being mixed. It is preferable to use a roll laminator because it is easy and continuous production is possible.
Although the pressurization at the time of lamination is not particularly limited, for example, when a roll laminator is used, the linear pressure is preferably 1 to 20 kgf / cm. Although the temperature of the pressurizing part at the time of lamination | stacking is not specifically limited, either the low temperature is preferable from the point of an equipment burden, and it is more preferable that it is the normal room temperature range 20-40 degreeC without special heating. The room temperature is a normal room temperature in a temperate region including Japan, and is in the above temperature range. However, if it is below this temperature range in winter, or if it is desired to reliably prevent bubbles from being mixed even if the layers are laminated at a higher speed, the temperature may be increased to over 40 ° C. as necessary. In the case of heating, the temperature is usually set to about 40 to 60 ° C. from the viewpoints of saving of utility costs and capital investment, ensuring safety during work, preventing deterioration of the optical filter due to heat, and the like.

  FIG. 7 shows an example of a lamination process of an electromagnetic wave shielding sheet and an adhesive optical filter using a laminator. The first sheet feeding unit 31 of the laminator is arranged with the electromagnetic shielding sheet wound up, and the second sheet feeding unit 32 is arranged with the laminated sheet composed of the release film / adhesive layer / optical filter. To do. Next, the electromagnetic wave shielding sheet is fed out from the first paper feed unit 31, while the laminated sheet composed of the release film / adhesive layer / optical filter is fed out from the second paper feed unit 32 and simultaneously the release film is taken up. 34, the electromagnetic wave shielding sheet and the optical filter with the adhesive layer are sandwiched between the pair of pressure rollers by the first laminating unit 35 and laminated at a laminating pressure of about 10 kgf / cm, and then the second laminating. A unit 36 can be laminated at a laminating pressure of about 10 kgf / cm and wound on a take-up roll 37 to obtain a composite filter comprising an electromagnetic wave shielding sheet / adhesive layer / optical filter laminated sheet.

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

  Hereinafter, the present invention will be specifically described with reference to examples. These descriptions do not limit the present invention. In the examples, parts represent parts by weight unless otherwise specified.

<Example 1>
A composite filter having a layer structure shown in FIG. 1C was manufactured as follows.
(1) Production of Electromagnetic Wave Shielding Sheet First, as a transparent base material 11, a continuous belt-shaped uncolored transparent biaxially stretched polyethylene terephthalate film having a thickness of 100 μm and a polyester resin primer layer formed on one side was prepared.
On the primer layer of the transparent substrate, a nickel-chromium alloy layer having a thickness of 0.1 μm and a copper layer having a thickness of 0.2 μm (a part of the conductor layer) are sequentially provided by sputtering. Treatment layer 13 was obtained.

  A copper metal layer 14 (remaining portion of the conductor layer) having a thickness of 2.0 μm is provided on the surface of the conductive treatment layer by an electrolytic plating method using a copper sulfate bath. Both layers were formed as the conductor layer 12, and the copper-clad laminate sheet was produced in which the conductor layer was directly formed on the transparent substrate without interposing the adhesive layer therebetween.

Next, a blackening layer 15 was formed on the conductor layer. Specifically, a nickel plate is used for the anode, and the mesh-like conductor layer is formed on a transparent base material in a blackening plating bath made of a mixed aqueous solution of a nickel ammonium sulfate aqueous solution, a zinc sulfate aqueous solution and a sodium thiocyanate aqueous solution. The laminated sheet formed above is immersed and electroplated to perform blackening treatment, and a blackened layer 15 made of a nickel-zinc alloy is formed on the entire surface of the exposed conductor layer so as to be conductive. A sheet on which the body layer 12 (the conductive treatment layer 13, the metal layer 14, and the blackening layer 15) was laminated was obtained.
Next, a mesh region 101 including an opening 103 and a line portion 104 was formed on the laminated sheet by etching the conductor layer using a photolithography method.

  Specifically, using a production line for a color TV shadow mask, the etching was performed consistently from masking to etching on the continuous belt-like laminated sheet. That is, after applying a photosensitive etching resist to the entire surface of the conductor layer of the laminated sheet, a desired mesh pattern is closely exposed, developed, hardened, and baked on the area corresponding to the line portion of the mesh. After processing the resist layer into a pattern in which the resist layer remains and there is no resist layer on the area corresponding to the opening, the conductor layer including the blackened layer is etched away with an aqueous ferric chloride solution. Then, a mesh-shaped opening was formed, and then water washing, resist peeling, washing, and drying were sequentially performed.

  The mesh shape of the mesh region is such that the line width of the linear portion where the opening is a square and a non-opening is 10 μm, the line interval (pitch) is 300 μm, the height of the line is 2.3 μm, rectangular When cut into single sheets, the bias angle defined as the minor angle with respect to the long side of the rectangle was 49 degrees. In addition, when the completed composite filter is mounted on the front surface of the image display device (display), the mesh region 101 has a portion facing the image display region of the display, and the mesh region 101 is located at the periphery of the mesh region. Is designed in such a pattern that when the electromagnetic wave shielding sheet is cut into a rectangular sheet, a frame portion having a width of 15 mm without an opening is left as a grounding region on the outer periphery of the four sides. Thus, the electromagnetic wave shielding sheet of Example 1 having no planarization layer was obtained.

(2) Manufacture of sheet-fed adhesive optical filter (adhesive optical filter) Next, a sheet-fed adhesive optical filter (adhesive optical filter) to be laminated on the electromagnetic wave shielding sheet was prepared. As the layer configuration of the optical filter, an anti-reflection filter / ultraviolet absorption filter / adhesive layer 22 (adhesive layer 22 also serves as a near infrared absorption filter and a neon light absorption filter) was prepared.
As the ultraviolet absorbing filter, a Tetron film (trade name “HB type” manufactured by Teijin Ltd.), which is a transparent biaxially stretched PET film having a thickness of 50 μm and kneaded with an ultraviolet absorber, was used. The ultraviolet absorbing filter is also used as a base material for coating and forming an antireflection filter.

The antireflection filter was formed by sequentially forming a high refractive index layer and a low refractive index layer on the ultraviolet absorption filter.
Here, the high refractive index layer is a cured product having a thickness of 3 μm and a refractive index of 1.69 of a composition (trade name “KZ7973” manufactured by JSR Corporation) in which ultrafine zirconia particles are dispersed in an ultraviolet curable resin. Consists of layers.
The low refractive index resin layer is made of a cured product having a thickness of 100 nm and a refractive index of 1.41 of a fluororesin-based ultraviolet curable resin (manufacturer; JSR Corporation, trade name “TM086”).

An adhesive layer 22 was formed on the opposite side of the ultraviolet absorber layer from the antireflection filter. As the pressure-sensitive adhesive, a sheet-like acrylic resin-based pressure-sensitive adhesive having a release paper / pressure-sensitive adhesive layer 25 μm / release paper layer structure (manufacturer: Yodogawa Paper Mill, trade name: “TU-41A Kai”, storage at 20 ° C. Elastic modulus: 4.72 × 10 ⁵ Pa) was used. One of the sheet-like adhesive release papers was peeled off, and the exposed adhesive layer and the ultraviolet absorption filter of the optical filter were adhered and laminated together. As lamination conditions at this time, lamination was carried out by applying a maximum pressure of 10 kg / cm with a rubber roller at a room temperature of 20 ° C.
The adhesive optical filter having the above configuration is cut in the same shape as the part (rectangular) facing the image display area on the mesh area of the electromagnetic wave shielding sheet, and the dimensions are cut large by 4 mm in both the vertical and horizontal directions. A foliated adhesive optical filter was obtained.

(3) Manufacture of composite filter Then, the obtained electromagnetic wave shielding filter and the single-wafer adhesive optical filter are arranged in a direction in which the adhesive layer faces the mesh-like region of the conductor mesh layer, and The single-wafer adhesive optical filters were aligned so as to cover the entire portion of the mesh-like region facing the image display region, and then laminated to each other. As lamination conditions at this time, lamination was carried out by applying a maximum pressure of 10 kg / cm with a rubber roller at a room temperature of 20 ° C. Thus, the composite filter for display of Example 1 was manufactured.

<Example 2>
In the composite filter of Example 1, the pressure-sensitive adhesive was a release paper / pressure-sensitive adhesive layer 25 μm / sheet-shaped acrylic resin-based pressure-sensitive adhesive having a layer configuration of release paper (manufacturer; Panac, trade name; “PD-S1”, Storage modulus at 20 ° C .: 9.29 × 10 ⁵ Pa). Otherwise, the composite filter of Example 2 was manufactured in the same manner as Example 1.

<Comparative Example 1>
In the composite filter of Example 1, the pressure-sensitive adhesive was a sheet-shaped acrylic resin-based pressure-sensitive adhesive having a release paper / pressure-sensitive adhesive layer of 25 μm / release paper (manufacturer; Yodogawa Paper Mill, trade name; “TD-06A”). ”, Storage elastic modulus at 20 ° C .: 9.87 × 10 ⁵ Pa). Otherwise, the composite filter of Comparative Example 1 was produced in the same manner as Example 1.

<Comparative example 2>
In the composite filter of Example 1, the thickness of the conductor layer was changed to 10 μm as follows. Otherwise, the composite filter of Comparative Example 2 was produced in the same manner as in Example 1.
(1) Production of electromagnetic wave shielding sheet The electromagnetic wave shielding sheet shown in FIG. 1 was produced as follows. First, as a metal foil used as the conductor layer 12, a continuous strip-shaped electrolytic copper foil having a thickness of 10 μm and having a blackened layer 15A made of copper-cobalt alloy particles formed on one surface was prepared.
In addition, a continuous strip-shaped uncolored transparent biaxially stretched polyethylene terephthalate film having a thickness of 100 μm and a polyester resin primer layer formed on one surface was prepared as the transparent substrate 11.
And after carrying out galvanization with respect to both surfaces of the said copper foil, the well-known chromate process was performed by the dipping method, and the antirust layers 16A and 16B were formed in both front and back surfaces.

Next, the copper foil is composed of 12 parts by mass of a polyester polyurethane polyol having an average molecular weight of 30,000 and a curing agent of 1 part by mass of a xylene diisocyanate-based prepolymer on the transparent substrate primer layer on the blackened layer surface side. After dry laminating with a transparent two-component curable urethane resin adhesive, it is cured at 50 ° C. for 3 days to have a transparent adhesive layer having a thickness of 10 μm between the copper foil (rust preventive layer) and the transparent substrate. A continuous belt-like copper-clad laminate sheet was obtained.
Next, a mesh-like region 101 composed of the opening 103 and the line portion 104 was formed on the copper-clad laminate sheet by etching the conductor layer and the blackened layer using a photolithography method.
The etching process is the same as in Example 1. The height of the line portion of the mesh region is 10 μm, but the shape and dimensions of the other mesh regions are the same as those in the first embodiment.
Thus, the electromagnetic wave shielding sheet of Comparative Example 2 was obtained.

(2) Manufacture of sheet-fed adhesive optical filter In the same manner as in Example 1, a sheet-fed adhesive optical filter (adhesive optical filter) was obtained.
(3) Manufacture of composite filter And in the same manner as in Example 1, a single-wafer adhesive optical filter was bonded and laminated on the mesh area of the obtained electromagnetic shielding sheet.
In this way, a composite filter of Comparative Example 2 was obtained.

[Performance evaluation method]
The following points were evaluated with respect to the above examples and comparative examples. The evaluation results are shown in Table 1.
(1) Dynamic viscoelasticity of pressure-sensitive adhesive After a sheet-like acrylic pressure-sensitive adhesive layer having a layer structure of release paper / pressure-sensitive adhesive layer 25 μm / release paper is rolled into a spherical shape having a diameter of 5 mm, about 3 mm What was cut into thickness is a dynamic viscoelasticity measuring device (Rheometric Scientific, trade name “Solid Viscoelasticity Analyzer RSA-II”, Measurement Attachment; Parallel Plate Fixture RSA-SL-PP4.75HT) Is used to perform dynamic viscoelasticity measurement under temperature rise control at a measurement frequency of 1 Hz, a measurement temperature of 10 to 30 ° C., and a temperature rise rate of 5 ° C./min, and a storage elastic modulus E ′ (Pa) at 20 ° C. is obtained. It was.

(2) Transparency of composite filter The composite filter was visually seen through and compared.
Cloudy (cloudy), or the presence of bubbles is not recognized; ○
Those that are cloudy or have the presence of bubbles; x

<Summary of results>
The following can be seen from the above examples and comparative examples.
Although the composite filter of the present invention obtained in Examples 1 and 2 was pressure-laminated at room temperature (20 ° C.) without vacuuming such as an autoclave, there was no mixing of bubbles in the mesh region, Excellent transparency.

On the other hand, in the composite filter obtained in Comparative Example 1 in which the storage elastic modulus of the pressure-sensitive adhesive exceeded the range of the present invention, the presence of bubbles was recognized and the transparency was insufficient.
In addition, the presence of bubbles was observed in the composite filter obtained in Comparative Example 2 in which the height of the line portion of the mesh region exceeded the range of the present invention, and the transparency was insufficient.

It is sectional drawing of an example of the composite filter for displays of this invention. It is a perspective view of an example of the electromagnetic wave shielding sheet of the present invention. It is sectional drawing which shows an example of the electromagnetic wave shielding sheet of this invention. It is sectional drawing which shows an example of the process of the electromagnetic wave shielding sheet used for this invention. It is sectional drawing which shows an example of the adhesive optical filter used for this invention. It is sectional drawing which shows an example of the composite filter for a display of this invention. It is process drawing which shows an example of the lamination | stacking process of an electromagnetic wave shielding sheet and an adhesive optical filter among the manufacturing methods of the composite filter for displays of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Composite filter for displays 2 Laminated body 3 Electromagnetic wave shielding sheet 4 Adhesive optical filter 11 Transparent base material 12 Conductor mesh layer (conductor layer)
DESCRIPTION OF SYMBOLS 13 Conductive treatment layer 14 Metal layer 15 Blackening layer 16 Rust prevention layer 21 Optical filter 22 Adhesive layer 31 1st paper feed part 32 2nd paper feed part 34 Release film winding roll 35 1st laminating unit 36 2nd lamination Unit 37 Winding roll 101 Mesh area 103 Opening 104 Line

Claims (2)

A composite filter for display in which a conductive mesh layer having a mesh region, an adhesive layer, and an optical filter are provided at least in this order on one surface of a transparent substrate, and the mesh shape in the conductive mesh layer The height of the line portion of the region is 3 μm or less, the opening width of the opening of the mesh region is 150 μm or more, and the adhesive layer has a storage elastic modulus E ′ at 20 ° C. of dynamic viscoelasticity at a frequency of 1 Hz. (Pa) is E ′ ≦ 9.5 × 10 ⁵
A composite filter for a display formed by an adhesive. (A) An electromagnetic wave shielding sheet prepared by laminating at least a conductor mesh layer having a mesh-like region having a line portion height of 3 μm or less and an opening width of 150 μm or more on one surface of a transparent substrate is prepared. And a process of
(B) On one surface of the optical filter, the storage elastic modulus E ′ (Pa) at 20 ° C. of dynamic viscoelasticity at a frequency of 1 Hz is E ′ ≦ 9.5 × 10 ^5.
A step of preparing an adhesive optical filter formed by laminating an adhesive layer formed of an adhesive that is:
(C) For a display comprising a laminate of an electromagnetic wave shielding sheet and an adhesive optical filter, wherein the adhesive layer side of the adhesive optical filter is laminated toward the conductor mesh layer side of the electromagnetic wave shielding sheet. A method for manufacturing a composite filter.

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