JP2009051009A - Front filter for plasma display panel and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a front filter for a plasma display panel which has a simple layer composition and a few manufacturing processes, is excellent in productivity, has high total light transmittance, and can be inexpensively obtained, and to provide a method of manufacturing the same. <P>SOLUTION: In the front filter 1 for the plasma display panel, a hard coat layer 5 having antistatic performance is provided directly or through one or more layers on the front side of transparent resin film 6 having ultraviolet shielding performance, and transparent laminated film 3 having a near infrared ray shielding layer and a transparent substrate 10 having an electromagnetic wave shielding layer 9 are affixed through an adhesive layer 8 on the rear side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a front filter for a plasma display panel that has a simple layer structure, has few manufacturing steps, is excellent in productivity, has high total light transmittance, and can be realized at low cost, and a method for manufacturing the same.

Since a plasma display (PDP, Plasma Display Panel) uses plasma discharge for light emission, electromagnetic waves over a wide frequency range are radiated.
In recent years, the influence of leakage electromagnetic waves from digital devices on the human body and other devices has been studied, and the FCC (Federal Communications Commission) standard in the United States and the Japanese VCCI (information processing equipment, etc.) It is necessary to keep it within the standard value by Voluntary Control Council for Information Technology Equipment.
Moreover, it is known that PDP emits near-infrared rays, which may cause malfunction of electronic devices such as cordless headphones and remote controllers. For this reason, it is necessary to suppress near infrared rays to a level where there is no practical problem.
Furthermore, the PDP is required to have less reflection of a light source irradiated from an external light source such as a fluorescent lamp in order to improve its visibility. It is also important to correct the color tone of the luminescent color. Furthermore, from the viewpoint of use, an antistatic function is required so that dust does not adhere to the display surface.

In response to these requirements, a front plate having at least three functional films of an electromagnetic wave shielding film, a near-infrared shielding film, and an antireflection film having an antistatic function is generally used on the display screen. Measures have been taken to arrange the surfaces (see, for example, Patent Document 1).
However, in this case, at least three functional films must be prepared separately and bonded to each other, resulting in poor productivity.

  On the other hand, in recent years, from the viewpoint of cost reduction, in the outermost antireflection film, by providing a near-infrared shielding layer on the surface opposite to the antireflection layer of the base material, it is possible to reflect with one film A functional film having a prevention performance and a near-infrared shielding layer has been developed (see, for example, Patent Document 2).

JP 2005-72472 A (pages 5 and 6) JP 11-305033 A (page 3)

However, even when a front filter for PDP is prepared using the functional film described in Patent Document 2, as described in Patent Document 1, the electromagnetic wave shielding layer is conventionally formed on a transparent resin film. For this reason, since a minimum of two films and a two-step bonding process are required, there are many manufacturing processes and the manufacturing yield is poor. Furthermore, since many films and pressure-sensitive adhesive layers that are not necessary as functions are used, there have been problems such as deterioration in total light transmittance and increase in material costs.
In addition, as an electromagnetic wave shielding layer conventionally used for an electromagnetic wave shielding layer, an etching mesh obtained by lithography such as photolithography, a transparent conductive film prepared by forming a thin film on a substrate by sputtering, a paste containing a catalyst A plating mesh produced by printing a mesh pattern on a film and then plating is mentioned. However, in these production methods, there are many production steps, production yield is poor, and cost is high. Moreover, since the plating mesh requires a plating process, there is a concern about the problem of environmental pollution.

  Under such circumstances, the present invention sufficiently satisfies all of antistatic performance, ultraviolet shielding performance, near infrared shielding performance and electromagnetic shielding performance, preferably antireflection performance, and has a simple layer structure and a production process. The purpose of the present invention is to provide a front filter for a PDP that has a small amount, excellent productivity, high total light transmittance, and can be realized at low cost.

  In order to achieve the above object, the PDP front filter of the first invention in the present invention has antistatic performance directly or through one or more layers on the front side of the transparent resin film having ultraviolet shielding performance. A hard coat layer is provided, and a transparent laminated film provided with a near-infrared shielding layer on the rear surface side and a transparent substrate provided with an electromagnetic wave shielding layer are bonded together via an adhesive layer. is there.

  The front surface (side) and the rear surface (side) refer to positions relative to the PDP, and the viewer side is the front surface side, and the inside of the display (inside the apparatus) is the rear surface side.

  The front filter for PDP of the second invention is characterized in that the electromagnetic wave shielding layer is a layer (mesh-like metal layer) formed by pattern-printing a conductive material in a grid pattern.

  In the front filter for PDP of the third invention, the pressure-sensitive adhesive layer is a layer having a color correction function.

  According to a fourth aspect of the present invention, there is provided a PDP front filter, wherein a dereflection layer is provided on the front side of the hard coat layer.

  The PDP front filter according to a fifth aspect of the present invention is characterized in that all the layers constituting the PDP front filter are all formed by wet coating.

  According to a sixth aspect of the present invention, there is provided a method for producing a PDP front filter, wherein all the layers constituting the PDP front filter are formed by wet coating.

According to the present invention, the following effects can be exhibited.
The front filter for PDP according to the first aspect of the invention is produced with a single layer (transparent laminated film) having ultraviolet shielding performance, antistatic performance, and near infrared shielding performance, so the layer structure is simple and the number of manufacturing processes is small. Excellent in properties. Furthermore, in order to construct the front filter for PDP by laminating the transparent laminated film and a transparent base material having electromagnetic wave shielding performance via an adhesive layer, it is necessary to use only one transparent resin film, Compared to the conventional configuration using a plurality of films, the total light transmittance is improved, and furthermore, only one bonding step for reducing the yield is required, which is excellent in productivity and can be realized at low cost. .

  In addition to the above-described effect, the PDP front filter according to the second aspect of the invention is an electromagnetic wave formed by etching or plating because the electromagnetic wave shielding layer is a layer (mesh-like metal layer) obtained by pattern-printing a conductive material in a grid pattern. Compared to the shielding layer, the number of manufacturing steps is small, and it is excellent in productivity and can be realized at low cost.

  In addition to the above effects, the PDP front filter of the third invention can provide a PDP front filter having excellent color purity because the pressure-sensitive adhesive layer has a color correction function.

  In addition to the above effects, the front filter for PDP of the fourth invention has a reflection-reducing layer on the front surface side of the hard coat layer, so that there is little reflection of the light source irradiated from an external light source such as a fluorescent lamp Visibility can be improved.

  In addition to the above effects, the PDP front filter according to the fifth aspect of the invention is excellent in productivity and low cost because all the layers constituting the PDP front filter are all formed by wet coating.

  Since the manufacturing method of the front filter for PDP of 6th invention forms all the layers which comprise the said front filter for PDP by wet coating as demonstrated in the said 5th invention, the said outstanding characteristic The front filter for PDP having the above can be easily mass-produced and has high practical value.

FIG. 1 shows a longitudinal sectional view of an example of a front filter for PDP of the present invention. In each figure, the upper side is the front side (front side), and the lower side is the back side (rear side = side where the PDP is arranged). In FIG. 1, a PDP front filter 1 includes a transparent resin film 6 having ultraviolet shielding performance and a hard coat layer 5 having antistatic performance formed on the surface side thereof (in the drawing, the antireflection layer 11 is further provided on the surface side). A near-infrared shielding layer 7 formed on the back side, a transparent laminated film 3 provided with a pressure-sensitive adhesive layer 8 having color correcting ability on the back side, and an electromagnetic wave shielding layer 9 It is formed by pasting together a transparent substrate (glass substrate) 10. Reference numeral 2 denotes a hard coat film, and 4 denotes a glass with an electromagnetic wave shielding layer.
In the present specification, the term “transparency” or “transparency” does not limit the light transmittance or transparency, and is used in the sense that it does not impede the visual recognition of the PDP as much as possible.

(Transparent resin film 6 having ultraviolet shielding performance)
Although it does not specifically limit as a transparent resin film in this invention as long as it has transparency and ultraviolet-ray shielding performance, In order to suppress reflection, refractive index (n) exists in the range of 1.55-1.70. Are preferred. Examples of the material of the transparent resin film include polyesters such as polyethylene terephthalate (PET, n = 1.65), polycarbonate (PC, n = 1.59), polyarylate (PAR, n = 1.60), and polyether. Sulfone (PES, n = 1.65) or the like is preferable. Among these, a polyester film, particularly a polyethylene terephthalate film is preferable in terms of ease of molding, availability, and cost.
Moreover, the thickness of a transparent resin film becomes like this. Preferably it is 25-400 micrometers, More preferably, it is 50-200 micrometers.
As the transparent resin film having the ultraviolet shielding performance, an ultraviolet absorber may be mixed in the transparent resin film as long as the transparency is not impaired. As this ultraviolet absorber, a known ultraviolet absorber is used, for example, a salicylic acid compound, a benzophenone compound, a benzotriazole compound, a cyclic imino ester compound, etc., among which a benzophenone compound and a benzotriazole compound are preferable. A cyclic imino ester compound is particularly preferable. The content of these ultraviolet absorbers is preferably added so that the light transmittance of ultraviolet rays having a wavelength of 380 nm or less is 5% or less, more preferably 3% or less. It is particularly preferable to add so as to be as follows. When the light transmittance at a wavelength of 380 nm or less exceeds 5%, a sufficient ultraviolet shielding effect cannot be expected for the dye in the pressure-sensitive adhesive layer, which is not preferable. In addition, the transparent resin film may contain various additives. Examples of such additives include ultraviolet absorbers other than those mentioned above, antistatic agents, stabilizers, plasticizers, lubricants, flame retardants and the like. In addition, as the transparent resin film having the ultraviolet shielding performance, since a PET film already kneaded with an ultraviolet absorber is available on the market, it may be used (used in Examples described later). ).

(Hard coat layer 5)
The hard coat layer in the present invention has antistatic properties, and is preferably formed from a material (= hard coat layer forming composition) containing an ultraviolet curable resin, an antistatic agent, and a photopolymerization initiator. The

The ultraviolet curable resin added to the composition for forming a hard coat layer is a resin that undergoes a curing reaction when irradiated with ultraviolet rays, and the type thereof is not particularly limited. Specifically, for example, monofunctional (meth) acrylate [in the present specification, (meth) acrylate means a generic name including both acrylate and methacrylate. ], Polyfunctional (meth) acrylates. Among these, from the viewpoint of achieving both productivity and hardness, a composition containing an ultraviolet curable polyfunctional acrylate as a main component is preferable. The composition containing such an ultraviolet curable polyfunctional acrylate is not particularly limited. For example, a mixture of two or more known ultraviolet curable polyfunctional acrylates is commercially available as an ultraviolet curable hard coat material. The thing that is.
The ultraviolet curable polyfunctional acrylate is not particularly limited, and examples thereof include dipentaerythritol hexaacrylate, tetramethylol methane tetraacrylate, tetramethylol methane triacrylate, trimethylol propane triacrylate, and 1,6-hexanediol diester. Acrylic derivatives of polyfunctional alcohols such as acrylate and 1,6-bis (3-acryloyloxy-2-hydroxypropyloxy) hexane, polyethylene glycol diacrylate and polyurethane acrylate are preferred.

  As the antistatic agent added to the hard coat layer forming composition, known ones can be used. Examples of the metal oxide include ITO (indium-tin composite oxide) and ATO (antimony-tin composite oxide). ), Tin oxide, antimony pentoxide, zinc oxide, zirconium oxide, titanium oxide, zinc antimonate, and aluminum oxide. Moreover, it is preferable that the compounding quantity is normally selected in the range of 1-20 mass parts with respect to 100 mass parts of said ultraviolet curable resins.

Subsequently, the method for forming the hard coat layer having the above-described configuration is preferably formed by wet coating, and specifically, a general wet coat method such as a roll coat method, a coil bar method, a die coat method, an ink jet method or the like is employed. The
Further, the hard coat layer may contain other components in addition to the above compounds (ultraviolet curable resin, antistatic agent) as long as the effects of the present invention are not impaired. Other components are not particularly limited as long as they do not hinder the action of each of the above components, for example, inorganic or organic pigments, polymers, polymerization initiators, photopolymerization initiators, polymerization inhibitors, antioxidants, Examples thereof include additives such as a dispersant, a surfactant, a light stabilizer, and a leveling agent. Further, any amount of solvent can be added as long as it is dried after film formation by the wet coating method.
Furthermore, this hard coat layer can be formed by preferably carrying out a curing reaction by irradiation with active energy rays such as ultraviolet rays and electron beams and heating, if necessary, after being formed by a wet coating method. Such a curing reaction using active energy rays is preferably performed in an atmosphere of an inert gas such as nitrogen or argon.
The thickness of the hard coat layer is usually preferably in the range of 1 to 20 μm. When the thickness is less than 1 μm, it is difficult to impart sufficient hardness, which is not preferable. On the other hand, when the thickness exceeds 20 μm, problems such as a decrease in flex resistance occur, which is not preferable.

(Near-infrared shielding layer 7)
Next, the near infrared shielding layer will be described.
The near-infrared absorber contained in the near-infrared shielding layer in this invention is divided into an organic near-infrared absorber and an inorganic near-infrared absorber.
Examples of the inorganic near infrared absorber include tungsten oxide, titanium oxide, zirconium oxide, tantalum oxide, zinc oxide, indium oxide, tin-doped indium oxide, tin oxide, and antimony-doped tin oxide. Cesium oxide, zinc oxide, and the like. Among them, a tungsten oxide type is preferable because the transmittance of near infrared rays is low and the transmittance of visible light is high, and cesium-containing tungsten oxide is particularly preferable.
Examples of the organic near-infrared absorber include dyes such as polymethine, cyanine, phthalocyanine, naphthalocyanine, dithiol metal complex, naphthoquinone, anthroquinone, triphenylmethane, aminium, and diimmonium. Can be mentioned. Of these, diimonium salts containing sulfonimide as an anionic component are preferably used. As the diimonium salt, bis {bis (trifluoromethanesulfone) imidic acid} -N, N, N ′, N′-tetrakis (p-dibenzylaminophenyl) -p-phenylenediimonium, bis (1,3-disulfonyl) Hexafluoropropylimidic acid) -N, N, N ', N'-tetrakis (p-dibenzylaminophenyl) -p-phenylenediimonium and the like. These diimonium salts may be used alone or in combination of two or more.
Although the said diimonium salt can be used independently, unless the effect of this invention is impaired, it can be used in combination with another organic near-infrared absorber. When forming a near-infrared shielding layer, it can carry out using the organic binder which dissolved or disperse | distributed the said near-infrared absorber. Examples of the organic binder include polyolefins, polystyrene compounds, styrene-acrylic acid ester copolymers, poly (meth) acrylate alkyls, epoxy resins, and ultraviolet curable polyfunctional acrylates.
The near-infrared shielding layer may contain other components in addition to the organic binder as long as the effects of the present invention are not impaired. Other components are not particularly limited, and examples thereof include additives such as a polymerization inhibitor, an antioxidant, a dispersant, a surfactant, and a photopolymerization initiator.
Subsequently, the method for forming the near-infrared shielding layer is not particularly limited as long as it is based on wet coating, and general wet coating methods such as a roll coating method, a coil bar method, a die coating method, and an ink jet method are employed.
The thickness of the near infrared shielding layer is preferably in the range of usually 2 to 20 μm. When this thickness is less than 2 μm, it is difficult to sufficiently exhibit near-infrared shielding performance, which is not preferable. On the other hand, when the thickness exceeds 20 μm, problems such as a decrease in flex resistance occur, which is not preferable.

(Adhesive layer 8)
The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer in the present invention is not particularly limited as long as it has transparency. For example, an acrylic pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, and a silicone pressure-sensitive adhesive are preferably used. You may mix | blend a hardening | curing agent (crosslinking agent) etc. suitably as needed. The thickness of this pressure-sensitive adhesive layer is usually preferably in the range of 5 to 50 μm. The pressure-sensitive adhesive layer preferably contains a dye in order to correct the color tone of the display device. The dye may be a general dye or pigment having a desired absorption wavelength in the visible region, and the kind thereof is not particularly limited. For example, organic dyes such as anthraquinone, phthalocyanine, azo, and porphyrin are used. Can be mentioned. The type / concentration is determined by the absorption wavelength / absorption coefficient of the dye and the type / thickness of the medium or coating film to be dispersed, and is not particularly limited. In addition, although this adhesive layer was provided in the back surface side of the near-infrared shielding layer of a transparent laminated film in the said illustration example, you may make it provide in the surface side of the electromagnetic wave shielding layer of a transparent base material.

(Electromagnetic wave shielding layer 9)
The electromagnetic wave shielding layer in the present invention is not particularly limited in composition and composition, and may be any film formed so as to have electromagnetic wave shielding performance and image transparency. For example, the electromagnetic wave shielding layer was produced by etching a metal foil. Etching mesh, transparent conductive film prepared by forming a thin film on the surface of a transparent substrate by vapor deposition, sputtering, etc., paste containing catalyst such as palladium is printed on the surface of the transparent substrate in a grid pattern A plating mesh subjected to metal plating, and a coating mesh formed by baking a conductive paste after pattern printing on the surface of a transparent base material in a grid pattern can be used.
In particular, a coating mesh formed by pattern-printing a conductive paste on the surface of a transparent base material and then baking it is preferable for the electromagnetic wave shielding layer. Examples of the metal fine particles contained in the conductive paste include metals having excellent conductivity such as gold, silver, and copper. Furthermore, the particle diameter of the metal fine particles is preferably 5 μm or less, more preferably 1 μm or less from the viewpoint of printing.
Furthermore, the thickness of the electromagnetic shielding layer of the etching mesh, plating mesh, and coating mesh is preferably 1 to 10 μm, and the line width is preferably 30 μm or less.
The method for forming the electromagnetic wave shielding layer is not particularly limited as long as it is based on wet coating, and general wet coating methods such as direct gravure printing, offset gravure printing, and ink jet printing are employed.

(Transparent substrate 10)
The transparent substrate in the present invention is not particularly limited as long as it has transparency, but preferably can form the electromagnetic wave shielding layer, and mainly refers to a glass substrate, but is a transparent resin excellent in heat resistance. A molded body or the like may be used. More specifically, for example, a non-strengthened soda lime float glass substrate or the like can be used.

(Non-reflection layer 11)
The anti-reflection layer in the present invention can have a single layer structure or a multilayer structure. In the case of a single layer configuration, one layer having a refractive index lower than that of the hard coat layer (low refractive index layer) is formed on the front side of the hard coat layer. In the case of a multilayer structure, layers having different refractive indexes are laminated in a multilayer form on the front side of the hard coat layer. By adopting a multilayer structure, the reflectance can be lowered more effectively. From the viewpoint of the antireflection effect, a structure of three or more layers is preferable, and from the viewpoint of productivity and production cost, a single-layer structure or a two-layer structure is preferable.
The method for forming the antireflection layer is not particularly limited, and for example, a dry coating method, a wet coating method, or the like is employed. Among these methods, the wet coating method is particularly preferable in terms of productivity and production cost. The wet coating method may be a known method, and for example, a roll coating method, a spin coating method, a coil bar method, a dip coating method, etc. are representative methods. In these, the method which can form a low reflection layer continuously, such as a roll coat method, is preferable from the point of productivity and production cost. In order to express the function of the reduced reflection layer, it is a requirement that the formed layer has a lower refractive index than the layer immediately below, and the refractive index of the low refractive index layer is 1.20 to 1.55. It is preferable that it exists in the range. When the refractive index exceeds 1.55, it is difficult to obtain a sufficient antireflection effect by the wet coating method, whereas when it is less than 1.20, it tends to be difficult to form a sufficiently hard layer.
Examples of the material constituting the low refractive index layer include inorganic fine particles such as hollow silicon oxide, colloidal silicon oxide, lanthanum fluoride, and magnesium fluoride, organic polymer fine particles, and a simple substance or a mixture of fluorine-containing organic compounds. Can be used. In addition, a simple substance, a mixture, or a polymer of an organic compound not containing fluorine (hereinafter abbreviated as a non-fluorine organic compound) can be used as the binder resin.
The antireflection layer may contain other components in addition to the above compounds as long as the effects of the present invention are not impaired. Other components are not particularly limited. For example, inorganic or organic pigments, polymers, polymerization initiators, photopolymerization initiators, polymerization inhibitors, antioxidants, dispersants, surfactants, light stabilizers, leveling agents. And additives. Further, any amount of solvent can be added as long as it is dried after film formation by the wet coating method.
Further, the anti-reflection layer can be formed by preferably performing a curing reaction by irradiation with an active energy ray such as an ultraviolet ray or an electron beam or heating, if necessary, after being formed by a wet coating method. Such a curing reaction using active energy rays is preferably performed in an atmosphere of an inert gas such as nitrogen or argon.

(PDP front filter manufacturing method)
The manufacturing method of the front filter for PDP of this invention is demonstrated referring drawings.
A method for manufacturing the PDP front filter 1 illustrated in FIG. 1 will be described.
First, after applying the composition for forming a hard coat layer (coating solution) to the surface side (front side) of the transparent resin film 6 having the ultraviolet shielding performance of the above configuration, it is cured by irradiating with ultraviolet rays. A hard coat layer 5 is obtained. In the drawing, the antireflection layer 11 having the above-described configuration is further formed on the surface side (front side).
Moreover, the near-infrared shielding layer 7 of the said structure is obtained by apply | coating the near-infrared shielding layer coating liquid to the back surface side (rear surface side) of the said transparent resin film 6, and drying.
The formation of the hard coat layer 5 on the front side (front side) (and the formation of the antireflection layer 11) and the formation of the near-infrared shielding layer 7 on the back side (rear side) must be performed first. The hard coat film 2 may be produced.
Furthermore, the adhesive layer 8 of the said structure is formed by apply | coating the coating liquid as an adhesive to the back surface side (rear surface side) of the said near-infrared shielding layer 7, and drying and aging, and it is set as the transparent laminated film 3. .
Further, the conductive paste is pattern-printed in a lattice pattern on the front side (front side) of the transparent substrate (glass substrate) 10 having the above-described configuration, and the electromagnetic wave shielding layer 9 having the above-described configuration is formed by baking. Let it be the glass 4 with a layer.
Finally, the PDP front filter 1 of the present invention can be obtained by laminating the transparent laminated film 3 and the transparent substrate (glass substrate) 10 on which the electromagnetic wave shielding layer 9 is formed.

  Hereinafter, the embodiment will be described more specifically with reference to production examples, examples and comparative examples, but the present invention is not limited to these examples. The performance of the front filter for PDP in each example was evaluated according to the following method.

[Evaluation methods]
(1) Total light transmittance:
Measured using a haze meter (Nippon Denshoku Co., Ltd., model: NDH 2000) (2) Haze value:
Measured using a haze meter (Nippon Denshoku, Model: NDH 2000) (3) Minimum reflectance:
Measured using an ultraviolet-visible spectrophotometer (manufactured by JASCO, model: V-560) (4) UV and near-infrared transmittance:
The sample was measured using an ultraviolet-visible spectrophotometer (manufactured by JASCO, model: V-560), and ultraviolet and near-infrared transmittances (%) at wavelengths of 380 nm or less, 590 nm, 850 nm, and 950 nm were read.
(5) Adhesion:
A cross-cut peeling tape test was performed on the surface side provided with the hard coat layer in accordance with JIS D0202-1998. After using cellophane tape (manufactured by Nichiban Co., Ltd., CT24) to adhere to the film, it was peeled off. Judgment is represented by the number of squares that do not peel out of 100 squares, and the case where peeling does not occur is 100/100, and the case where peeling completely occurs is represented as 0/100.
(6) Pencil hardness:
A scratch test was performed with a pencil in accordance with JISK5400.
(7) Surface resistivity:
Based on JISK6911-1995, it measured using the digital insulation meter ([SM-8220], the Toa DK Corporation make).
(8) Electromagnetic wave shielding properties:
Measurements were made using the KEC method.

[Example 1]
A 100 μm thick PET film (trade name: HB3, manufactured by Teijin DuPont Films Ltd.) is used as a transparent resin film having an ultraviolet shielding property, and 95 parts by mass of dipentaerythritol hexaacrylate on the surface side (front side), antistatic Hardware containing 17 parts by mass of antimony-doped tin oxide (Ishihara Sangyo Co., Ltd., trade name: SNS-10M) and 4 parts by mass of a photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure 184) The coating material for the coat layer was applied so that the dry film thickness was about 5 μm, and after drying, a hard coat layer was formed by irradiating with ultraviolet rays.
Next, 5.0 parts by mass of an organic near-infrared absorber (manufactured by Nippon Carlit Co., Ltd., trade name; CIR-1085F) on the back side (rear side), an acrylic resin (manufactured by Mitsubishi Rayon Co., Ltd.) as a binder resin , Trade name: Dianal BR-80) A near-infrared shielding layer coating solution containing 100 parts by weight, 450 parts by weight of methyl ethyl ketone and 450 parts by weight of toluene is applied so that the dry film thickness is about 10 μm and dried. A near-infrared shielding layer was formed.
Subsequently, 100 parts by weight of a pressure-sensitive adhesive (main agent) (manufactured by Soken Chemical Co., Ltd., trade name; SK-2094) on the near-infrared shielding layer, a cross-linking agent (manufactured by Soken Chemical Co., Ltd., trade name: E-AX) ) A coating containing 2.7 parts by mass was applied so that the dry film thickness was about 25 μm, and after drying, an adhesive layer was formed by aging to obtain a transparent laminated film.
Subsequently, an electromagnetic wave shielding layer was formed on the glass substrate. Conductive paste (Daiken Chemical Co., Ltd., trade name: NAG-10) is patterned in a lattice pattern of L / S (line width / space width) = 30/270 (μm) so that the dry film thickness is 10 μm. It was printed and then dried at 300 ° C. for 10 minutes.
Finally, by laminating the transparent laminated film obtained as described above and the glass substrate on which the electromagnetic wave shielding layer obtained as described above is laminated, the structure shown in FIG. 1 (however, no antireflection layer is provided). ) PDP front filter was formed.
The obtained front filter for PDP was evaluated for “total light transmittance”, “minimum reflectance”, “transmittance”, “adhesion”, “pencil hardness”, “surface resistivity”, and “electromagnetic wave shielding”. . The evaluation results are shown in Table 1.

[Example 2]
A front filter for PDP was formed in the same manner as in Example 1 except that the pressure-sensitive adhesive in the pressure-sensitive adhesive layer was changed to a color correction pressure-sensitive adhesive. As this color correction adhesive, 100 parts by mass of an adhesive (main agent) (manufactured by Soken Chemical Co., Ltd., trade name: SK-2094), a crosslinking agent (trade name: E-AX, manufactured by Soken Chemical Co., Ltd.) 2 0.7 parts by mass, dye 1 (manufactured by Yamada Chemical Co., Ltd., trade name: TAP-2) 0.02 parts by mass, dye 2 (Orient Chemical Co., Ltd., trade name: VR. 3304) 02 parts by mass, Dye 3 (Orient Chemical Industry Co., Ltd., trade name: OB 613) 0.01 part by mass, Dye 4 (Orient Chemical Industry Co., Ltd., trade name; VG 2520) 0. A coating material for an adhesive layer containing 01 parts by mass and 23 parts by mass of methyl ethyl ketone (MEK) as a solvent was used. The evaluation results are shown in Table 1.

Example 3
A front filter for PDP was formed in the same manner as in Example 2 except that the antireflection layer was formed on the surface side of the hard coat layer. This antireflection layer was formed as follows. 104 parts by mass of perfluoro- (1,1,9,9-tetrahydro-2,5-bisfluoromethyl-3,6-dioxanonenol) and bis (2,2,3,3,4,4,4) 5,5,6,6,7,7-dodecafluoroheptanoyl) peroxide-containing fluorine-containing allyl ether polymer (number average molecular weight 72) obtained by polymerization reaction of 11 parts by mass of an 8% by mass perfluorohexane solution Fluorine-containing reactive heavy having a polymerizable double bond from 5 parts by mass, 43 parts by mass of methyl ethyl ketone (MEK), 1 part by mass of pyridine, and 1 part by mass of α-fluoroacrylic acid fluoride. A combined solution (solid content 13% by mass, α-fluoroacryloyl group introduction rate 40 mol%) was prepared. Also, hollow silica sol (manufactured by Catalyst Kasei Kogyo Co., Ltd., trade name: ELCOM NY-1001SIV, 25% dispersion of hollow silica sol with isopropyl alcohol, average particle size: 60 nm) 2000 parts by mass, γ-acryloyloxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., trade name: KBM5103) 70 parts by mass and 80 parts by mass of distilled water were mixed to prepare modified hollow silica fine particles (sol) (average particle size: 60 nm). And 50 parts by mass of the fluorine-containing reactive polymer solution, 50 parts by mass of the modified hollow silica fine particles, 2 parts by mass of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure 907), and isopropyl alcohol 2000 parts by mass was mixed to obtain a low refractive index layer coating solution. Then, the low refractive index layer coating solution obtained as described above is applied to the surface side of the hard coat layer by a gravure coating method so that the optical film thickness after drying becomes 110 to 125 nm, and after drying, nitrogen A reduced reflection layer was prepared by irradiating and curing ultraviolet rays at an output of 400 mJ / cm 2 under an atmosphere. The evaluation results are shown in Table 1.

As is apparent from the results of Example 1 in Table 1, the front filter for PDP of the present invention sufficiently satisfies the antistatic property, the near infrared shielding property, the ultraviolet shielding property, and the electromagnetic wave shielding property. Since the layer is formed by wet coating, it can be realized at low cost.
Moreover, it was confirmed from the result of Example 2 using the adhesive which has a color correction function that the transmittance | permeability of 590 nm is cut moderately and the front filter for PDP excellent in color reproducibility is producible.
Finally, since the anti-reflection layer is formed in Example 3, it is possible to provide a front filter for PDP that further suppresses reflection and reflection of external light.

It is longitudinal cross-sectional explanatory drawing which shows typically one Example of the front filter for PDP of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front filter for PDP 2 Hard coat film 3 Transparent laminated film 4 Glass with electromagnetic shielding layer 5 Hard coating layer 6 Transparent resin film 7 Near infrared shielding layer 8 Adhesive layer 9 Electromagnetic shielding layer 10 Transparent substrate (glass substrate)
11 Anti-reflection layer

Claims (6)

  A transparent laminated film having an antistatic performance provided directly on the front side of a transparent resin film having an ultraviolet shielding performance or via one or more layers and a near-infrared shielding layer on the rear side, and an electromagnetic wave A front filter for a plasma display panel, wherein a transparent substrate having a shielding layer is bonded to each other through an adhesive layer.   The front filter for a plasma display panel according to claim 1, wherein the electromagnetic wave shielding layer is a layer formed by pattern-printing a conductive material in a lattice pattern.   3. The front filter for a plasma display panel according to claim 1, wherein the pressure-sensitive adhesive layer is a layer having a color correction function.   The front filter for a plasma display panel according to any one of claims 1 to 3, wherein a dereflection layer is provided on the front side of the hard coat layer.   5. The front filter for a plasma display panel according to claim 1, wherein each layer constituting the front filter for the plasma display panel is formed by wet coating.   A transparent laminated film having an antistatic performance provided directly on the front side of a transparent resin film having an ultraviolet shielding performance or via one or more layers and a near-infrared shielding layer on the rear side, and an electromagnetic wave A front filter for a plasma display panel, wherein each layer constituting the front filter for a plasma display panel, which is formed by bonding a transparent substrate having a shielding layer to each other via an adhesive layer, is formed by wet coating. Manufacturing method.

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