JP2004195930A - Impact absorbing sheet for front surface of plasma display panel and plasma display panel using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact absorbing sheet for a front surface of a PDP which is of low cost and light weight and can protect a PDP against outer impact and prevent effectively reflection of an outer light so that a high-quality display image can be obtained and a PDP device. <P>SOLUTION: The impact absorbing sheet for a front surface of a PDP for protecting the PDP, which is composed of a laminated material, is characterized in that one layer of the laminated material is composed of an elastic resin sheet and an elastic adhesive layer to be attached to the front surface of the PDP is adhered to one surface of the resin sheet. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a front impact absorbing sheet for a plasma display panel (hereinafter, referred to as a PDP) used for various thin display panels and a PDP device using the same.
[0002]
[Prior art]
The PDP can drastically reduce the depth compared to a CRT direct-view display device or a rear-projection display device, and is expected to be a promising means for realizing a wall-mounted large-screen television in the future. However, since various electrodes are provided on the glass substrate and the phosphor is caused to emit light by causing discharge between the electrodes, various types of protection such as protection of the glass substrate, prevention of reflection of external light, and prevention of unnecessary radiation are provided. It is also necessary to have functions.
[0003]
FIG. 3 is a perspective view showing a configuration of the PDP, wherein 1 is a front glass, 2 is a rear glass, 3 is a partition, 4 is an address electrode, 5R, 5G, 5B is a phosphor, 6 is a display electrode, and 7 is a display electrode. The dielectric layer 8 is a protective film. However, hatching representing a cross section may be omitted in the drawings in this specification.
[0004]
The PDP 11 has a configuration in which a front glass 1 and a rear glass 2 face each other while sandwiching a partition wall 3.
[0005]
A display electrode 6 is formed inside the front glass 1 and an address electrode 4 is formed inside the rear glass 2 by photo-etching or the like. The display electrodes 6 formed inside the front glass 1 and the address electrodes 4 formed inside the rear glass 2 are arranged so as to be orthogonal to each other.
[0006]
The display electrode 6 on the front glass 1 is covered with a dielectric layer 7 having a predetermined thickness formed by printing and firing low-melting glass, and a protective film 8 is formed thereon.
[0007]
On the back glass 2, the partition walls 3 are stacked by thick film printing for each address electrode 4, and the space between the adjacent partition walls 3 forms a cell. The phosphors 5R, 5G, and 5B are applied so as to cover the address electrodes 4, respectively.
[0008]
Further, a discharge gas mainly composed of neon is sealed in the cell space, and therefore, each cell forms a discharge cell.
[0009]
A discharge cell is located at each intersection of the orthogonal address electrode 4 and display electrode 6, and each discharge cell forms a pixel. Therefore, a plurality of pixels are arranged in a matrix.
[0010]
Next, FIG. 4 is a configuration diagram showing a conventional PDP device provided with a protection plate on the PDP shown in FIG. 3, where 11 is a PDP and 21 is a protection plate.
[0011]
The above-described PDP 11 is mounted in a housing of a PDP device (not shown), and a protection plate 21 is mounted on the front glass 1 side of the PDP 11 in the housing.
[0012]
In the protective plate 21, reference numeral 12 denotes an anti-reflection or anti-glare film, 13 denotes a heat-treated glass, 14 denotes an electrode, 15 denotes an adhesive layer, and 16 denotes a sputtered layer. These members are integrated to form the protection plate 21.
[0013]
The front glass 1 of the PDP 11 is very fragile, and if it is directly exposed to the outside, a slight impact may cause cracks. In addition, if the surface of the front glass 1 becomes dirty due to dust or a person easily touching the image, the displayed image becomes difficult to see. In order to prevent such a situation, a protection plate 21 is provided in front of the front glass 1. The user looks at the image displayed on the PDP 11 through the protection plate 21. For this reason, the protective plate 21 uses the heat-treated glass 13 so as not to be affected by a certain degree of impact, to prevent the occurrence of stains such as fingerprints (anti-stain), and to prevent the occurrence of bleeding. (Low haze), not to scratch even nails.
[0014]
When the heat-treated glass 13 is provided in front of the PDP 11, external light is reflected on the surface of the heat-treated glass 13. The reflection includes reflection at the front surface 13a of the heat-treated glass and reflection at the rear surface 13b of the heat-treated glass. As for the reflection of external light, there is a type in which external light transmitted through the protective plate 21 is reflected on the surface of the front glass 1, but this reflection occurs regardless of the presence or absence of the protective plate 21. For example, when such reflection is caused by light from an illumination lamp such as a fluorescent lamp, the illumination lamp is reflected on the heat-treated glass 13 as a reflection image, and the reflection is generated as described above. Since the reflection images occur in different paths, the reflection images appear in both double and triple, making the displayed image very difficult to see. In order to suppress the reflection of external light, an anti-reflection or anti-glare film 12 (for example, an AR film) is attached to the front surface 13a and the back surface 13b of the heat-treated glass.
[0015]
Further, in the PDP 11, light emission is performed by discharge, and this discharge generates a considerable amount of electromagnetic waves. In order to reduce this electromagnetic wave (that is, unnecessary radiation), a sputter layer 16 (for example, a film obtained by sputtering Ag) is provided on the surface of the protective plate 21 and the electrode 14 is provided on the lateral portion. Have good conductivity, thereby blocking electromagnetic waves. Further, in the PDP 11, infrared rays are generated due to excitation of the phosphor by discharge or the like, and the infrared rays adversely affect the remote control function of the own apparatus or another apparatus. Therefore, by coloring the adhesive layer 15 and the like, the generated infrared rays are prevented from going outside.
[0016]
In the adhesive layer 15, the light transmittance is reduced by adding a pigment or the like, and the contrast in a bright area of the image is increased (high contrast).
[0017]
The PDP device as described above functions as a front filter by providing various functions, but is heavy and expensive because the heat-treated glass 13 is used for the protection plate 21. Moreover, the effect on the antireflection function was far from desired. That is, although the protection plate 21 is originally provided as protection means for the front glass 1, the provision of the protection plate 21 increases the number of external light reflection surfaces and causes a problem that reflected images are reflected multiple times. For this reason, antireflection means was required, but the effect was not so much expected.
[0018]
As a method for preventing this reflection, there is a method in which the protective plate 21 is directly adhered to the front glass 1 of the PDP 11, but since there is an air interface between them, there is no drastic multiple reflection countermeasure. In this case, there is a problem that a Newton ring appears and the displayed image is difficult to see. To prevent this, the surface on the front glass 1 side of the protection plate 21 is made rough to scatter light, but this also deteriorates the quality of the displayed image.
[0019]
For this purpose, there is a method of providing a protective layer on a front glass substrate of a PDP without using a heat-treated glass (for example, see Patent Document 1). Such a protective film was insufficient to protect the front glass substrate from external impact.
[0020]
[Patent Document 1]
JP-A-11-260265
[0021]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and can protect a PDP from external impact, and is inexpensive, lightweight, and can effectively prevent reflection of external light. An object of the present invention is to provide a PDP front impact absorbing sheet capable of obtaining a display image of image quality, and a PDP device using the same.
[0022]
[Means for Solving the Problems]
In order to achieve the object, the present invention provides a plasma display panel front impact absorbing sheet comprising a laminate for protecting a plasma display panel, wherein one layer of the laminate comprises an elastic resin sheet; One side of the resin sheet is provided with an elastic adhesive layer that is attached to the front surface of the plasma display panel.
[0023]
When adhered to the front surface of the PDP by the adhesive layer, an external impact can be absorbed by the elastic adhesive layer and the elastic resin sheet, and the front glass of the PDP can be protected. That is, since a heavy and expensive heat-treated glass is not required, the PDP device can be made inexpensive and lightweight. Further, since the heat-treated glass is eliminated, the number of external light reflecting surfaces is reduced, and reflected light is significantly reduced. Furthermore, since an adhesive layer is present between the PDP front impact absorbing sheet and the PDP, there is no air layer, so that there is no problem that a Newton ring appears and the displayed image becomes difficult to see. Therefore, a display image with good image quality can be obtained.
[0024]
Further, since the PDP front impact absorbing sheet can be directly adhered to the PDP, the step of applying an adhesive or the like can be omitted, so that the PDP device can be easily assembled.
[0025]
Further, it is preferable that an elastic coat is provided on the opposite side of the resin sheet where the adhesive layer is provided.
[0026]
Further, it is preferable that the resin sheet is at least one selected from a silicone-based, a rubber-based, and a urethane-based resin.
[0027]
Further, it is preferable that at least one layer of the laminate is an antireflection or antiglare film.
[0028]
Further, it is preferable that the laminate has at least one function of reducing unnecessary radiation, cutting infrared rays, and adjusting light transmittance.
[0029]
Then, a plasma display panel device can be configured using the above-described plasma display panel front impact absorbing sheet.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0031]
The present invention includes a PDP front impact absorbing sheet alone or a PDP device using a PDP front impact absorbing sheet.
[0032]
FIG. 1 is a side view showing an example of an embodiment of the PDP device of the present invention, wherein 11 is a PDP, and 31 is a PDP front impact absorbing sheet.
[0033]
The above-mentioned PDP 11 is mounted in a housing of a PDP device (not shown), and a PDP front impact absorbing sheet 31 is mounted on the front glass side of the PDP 11 in this housing.
[0034]
The PDP front impact absorbing sheet 31 is a laminate, 30 is an adhesive layer, 32 is an antireflection or anti-glare film, 34 is an electrode, 35A is an adhesive layer, 35B is a toning adhesive layer, 36 is a sputter layer, 37 is a resin sheet. These members are integrated to constitute a PDP front impact absorbing sheet 31.
[0035]
In FIG. 1, a PDP front impact absorbing sheet 31 is adhered and fixed to the front glass surface of the PDP 11 by an elastic adhesive layer 30.
[0036]
Further, on the surface of the adhesive layer opposite to the PDP 11 (hereinafter referred to as the front surface), an elastic resin sheet 37, an adhesive layer 35A, a sputter layer 36 for reducing unnecessary radiation, and infrared rays do not go outside. The toning adhesive layer 35 </ b> B for performing the color correction is provided in this order.
[0037]
An anti-reflection or anti-glare film 32 is provided on the front surface of the PDP front impact absorbing sheet 31.
[0038]
Further, an electrode 34 for grounding is provided on a lateral portion of the PDP front impact absorbing sheet 31.
[0039]
The resin sheet is preferably made of at least one selected from a silicone-based, rubber-based, and urethane-based resin.
[0040]
Further, the thickness of the resin sheet is preferably 1 to 1000 μm. If the thickness of the resin sheet exceeds 1000 μm, the thickness of the PDP device cannot be reduced, and if the thickness of the resin sheet is less than 1 μm, an external impact is transmitted to the front glass of the PDP 11 to cause an obstacle such as cracking. May occur.
[0041]
The elastic modulus of the resin sheet is 1 × 10 ^Five ~ 1 × 10 ⁷ dyn / cm ^Two It is preferable that This is because if the thickness is in this range, the resin sheet absorbs the impact even from an external impact, so that the PDP is hardly damaged.
[0042]
Further, the transmittance of the resin sheet is preferably 80% or more, more preferably 91% or more. The haze is preferably at most 2%, more preferably at most 1.5%. The refractive index is preferably from 1.45 to 1.70.
[0043]
Next, as the adhesive layer, there are acrylic, rubber, polyester and the like, and it is particularly preferable to use an acrylic adhesive. Acrylic pressure-sensitive adhesives include, as a main monomer for imparting appropriate wettability and flexibility as a pressure-sensitive adhesive, a (meth) acrylic acid alkyl ester having a glass transition point of −10 ° C. or less when polymerized. One or two or more, and if necessary, a functional group-containing monomer such as acrylic acid, methacrylic acid, or 2-hydroxyethyl acrylate, and another copolymerizable monomer are appropriately dissolved using a polymerization catalyst. An acrylic polymer obtained by polymerization by a polymerization method, an emulsion polymerization method, a bulk polymerization method (particularly, a polymerization method using ultraviolet light), a suspension polymerization method, or the like, to which various additives such as a crosslinking agent are added is used. . A thermal crosslinking type, a light (ultraviolet ray, electron beam) crosslinking type, or the like may be used.
[0044]
Further, the thickness of the pressure-sensitive adhesive layer is 10 to 500 μm, and more preferably 25 to 300 μm. If the thickness of the adhesive layer exceeds 500 μm, the thickness of the PDP device cannot be reduced, and if the thickness of the adhesive layer is less than 10 μm, an external impact is transmitted to the front glass of the PDP 11 to cause a failure such as a crack. May occur.
[0045]
The elastic coefficient of the adhesive layer is 1 × 10 ^Five ~ 1 × 10 ⁷ dyn / cm ^Two It is preferable that Within this range, even if an external impact is applied, the adhesive layer absorbs the impact, so that the PDP is not easily damaged, and the adhesive thickness is instantaneously reduced, but the self-recovery is immediately achieved. This is because the smooth surface is restored as if nothing had occurred. In addition, when directly adhered to the PDP, it absorbs undulations on the PDP surface, and the lamination becomes good.
[0046]
In the above configuration, since the front surface of the PDP has an elastic adhesive layer and an elastic resin sheet, it absorbs an external impact and does not transmit the impact to the PDP, so that the front glass of the PDP can be protected. Become. Therefore, since heavy and expensive heat-treated glass is not used, the PDP device can be protected from external impact, and can be made inexpensive and lightweight.
[0047]
External light is applied to the PDP front shock absorbing sheet 31, but the reflection on the front of the PDP front shock absorbing sheet 31 is suppressed by the anti-reflection or anti-glare film 32 on the PDP front shock absorbing sheet 31, so that the PDP front shock absorbing sheet 31 is suppressed. It enters the shock absorbing sheet 31. External light that has passed through the inside of the PDP front impact absorbing sheet 31 travels into the PDP 11 with little reflection because the heat-treated glass forming the external light reflecting surface is not used. Therefore, it is excellent without causing reflection. For this reason, it is unnecessary to prevent reflection on the surface of the PDP 11.
[0048]
Furthermore, since the adhesive layer 30 exists between the PDP front impact absorbing sheet 31 and the PDP 11, there is no air layer, so that there is no problem that a Newton ring appears and the displayed image is difficult to see. That is, a display image with good image quality can be obtained.
[0049]
In addition, since the PDP front impact absorbing sheet 31 can be directly adhered to the PDP 11, the step of applying an adhesive or the like can be omitted, so that the PDP device can be easily assembled.
[0050]
FIG. 2 is a side view showing another example of the embodiment of the PDP device of the present invention, in which 11 is a PDP, and 41 is a PDP front impact absorbing sheet.
[0051]
The above-described PDP 11 is mounted in a housing of a PDP device (not shown), and a PDP front impact absorbing sheet 41 is mounted on the front glass 1 side of the PDP 11 in this housing.
[0052]
The PDP front impact absorbing sheet 41 is a laminate, 40 is an adhesive layer, 50 is a coat, 52 is an antireflection or antiglare film, 54 is an electrode, 55A is an adhesive layer, 55B is a toning adhesive layer, 46 Denotes a sputter layer, and 57 denotes a resin sheet. These members are integrated to constitute a PDP front impact absorbing sheet 41.
[0053]
FIG. 2 is the same as FIG. 1 except that a coat 50 is provided.
[0054]
That is, on the front surface of the adhesive layer, an elastic resin sheet 57, an elastic coat 50, an adhesive layer 55A, a sputter layer 56 for reducing unnecessary radiation, and infrared rays are prevented from going outside. A toning adhesive layer 55B for performing color correction is provided in this order.
[0055]
The coat is preferably made of at least one selected from a silicone-based, a rubber-based, and a urethane-based adhesive.
[0056]
Further, the thickness of the coat is preferably 0.1 to 5 mm. If the thickness of the coat exceeds 5 mm, the thickness of the PDP device cannot be reduced. If the thickness of the coat is less than 0.1 mm, a strong external impact is transmitted to the front glass of the PDP 11 to cause cracks. Failure may occur.
[0057]
The elastic modulus of the coat is 1 × 10 ^Five ~ 1 × 10 ⁷ dyn / cm ^Two It is preferable that This is because in this range, even if a strong external shock is applied, the shock is absorbed and the PDP is hardly damaged.
[0058]
In the above configuration, since the PDP has the elastic adhesive layer, the elastic sheet, and the elastic coat on the front surface, the same effects as those of the embodiment shown in FIG. 3 can be obtained. Further, since the coat 50 is provided as compared with the embodiment shown in FIG. 3, it can be protected from a stronger impact.
[0059]
In the PDP front impact-absorbing sheet of the present invention, at least one layer of the laminate is preferably an anti-reflection or anti-glare film. This is because the reflection on the front surface of the PDP front impact absorbing sheet is suppressed by the antireflection or antiglare film.
[0060]
The reflectance of the antireflection or antiglare film is preferably 3.0% or less as a regular reflectance, more preferably 1.5% or less. Usually, a low refractive index layer is provided as an antireflection or antiglare film. The low refractive index layer has a lower refractive index than the lower layer. The refractive index of the low refractive index layer is preferably from 1.2 to 1.55, more preferably from 1.20 to 1.50. The thickness of the low refractive index layer is preferably from 0.05 to 0.4 μm, and more preferably from 0.05 to 0.2 μm.
[0061]
In order to prevent reflection in a wide wavelength range, it is preferable to alternately stack layers having a high refractive index (medium / high refractive index) and layers having a low refractive index. The refractive index of the high refractive index layer is preferably from 1.65 to 2.40, and more preferably from 1.70 to 2.20. The refractive index of the middle refractive index layer is adjusted to be an intermediate value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably 1.50 to 1.90. The thickness of the middle / high refractive index layer is preferably from 0.005 to 100 μm, more preferably from 0.01 to 10 μm, and most preferably from 0.03 to 1 μm. The haze of the middle / high refractive index layer is preferably 5% or less, more preferably 3% or less, and most preferably 1.5% or less. The middle / high refractive index layer can be formed using a polymer having a relatively high refractive index. Examples of the polymer having a high refractive index include polystyrene, styrene copolymer, polycarbonate, melamine resin, phenol resin, epoxy resin, and polyurethane obtained by reacting a cyclic (alicyclic or aromatic) isocyanate with a polyol. It is. Other examples include a polymer having a cyclic (aromatic, heterocyclic, or alicyclic) group, and a polymer having a halogen atom other than fluorine as a substituent. A polymer may be formed by a polymerization reaction of a monomer capable of radical curing by introducing a double bond.
[0062]
In order to obtain a higher refractive index, inorganic fine particles may be dispersed in a polymer binder. The refractive index of the inorganic fine particles is preferably from 1.80 to 2.80. The inorganic fine particles are preferably formed from a metal oxide or sulfide. Examples of metal oxides or sulfides include titanium dioxide (eg, rutile, mixed crystals of rutile / anatase, anatase, amorphous structure), tin oxide, indium oxide, zinc oxide, zirconium oxide, zinc sulfide, and the like. . Titanium oxide, tin oxide and indium oxide are particularly preferred. The inorganic fine particles contain oxides or sulfides of these metals as main components and may further contain other elements. The main component means a component having the largest content (% by weight) of the components constituting the particles. Examples of other elements include Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P and S. Inorganic materials that are film-forming and dispersible in solvents or are themselves liquid, such as alkoxides of various elements, salts of organic acids, coordination compounds (eg, chelating compounds) combined with coordinating compounds, activity The middle / high refractive index layer can also be formed using an inorganic polymer.
[0063]
In the PDP front impact-absorbing sheet of the present invention, the laminate preferably has at least one function of reducing unnecessary radiation, cutting infrared rays, and adjusting light transmittance. This is because electromagnetic waves and / or infrared rays can be prevented from going outside. Also, high contrast can be achieved.
[0064]
In FIGS. 3 and 4, the sputtered layer has a function of reducing unnecessary radiation, and the toning adhesive layer has a function of cutting infrared rays and adjusting light transmittance.
[0065]
The surface resistance of the sputtered layer is 0.01 to 500 Ω / □ (also referred to as Ω / sq), and more preferably 0.01 to 10 Ω / □. The sputtered layer is preferably a transparent conductive layer so as not to lower the transmittance. Examples of the sputtered layer include a metal layer, a metal oxide layer, and a conductive polymer layer. Examples of the metal forming the metal layer include silver, palladium, gold, platinum, rhodium, aluminum, iron, cobalt, nickel, copper, zinc, ruthenium, tin, tungsten, iridium, and lead alone or an alloy of two or more of these. Among them, silver, palladium, gold, platinum, rhodium alone or an alloy thereof is preferable. Among them, an alloy of silver and palladium is preferable. At this time, the silver content is preferably 60 to 99% by weight, more preferably 80 to 98% by weight. The thickness of the metal layer is preferably 0.001 to 0.1 μm, more preferably 0.005 to 0.04 μm, and most preferably 0.01 to 0.03 μm. If the thickness is less than 000.1 μm, the electromagnetic wave shielding effect is poor, and if it exceeds 0.1 μm, the transmittance of visible light decreases. Examples of the metal oxide forming the metal oxide layer include tin oxide, indium oxide, antimony oxide, zinc oxide, ITO, and ATO. This film thickness is preferably from 0.020 to 1 μm. More preferably, it is 0.04 to 0.1 μm. It is also preferable to use a combination of the transparent conductive layer made of a metal layer and the transparent conductive layer made of a metal oxide layer. It is also preferable that a metal and a metal oxide coexist in the same layer. A transparent oxide layer can be laminated to protect the metal layer, prevent oxidative deterioration, and increase visible light transmittance. This transparent oxide layer may or may not be conductive. Examples of the transparent oxide layer include thin films of oxides of divalent to tetravalent metals, zirconium oxide, titanium oxide, magnesium oxide, silicon oxide, aluminum oxide, and metal alkoxide compounds. The method for forming the transparent conductive layer and the transparent oxide layer is not particularly limited, and an arbitrary processing method can be selected. For example, any known technique such as a sputtering method, a vacuum deposition method, an ion plating method, a plasma CVD method or a PVD method, application of ultrafine particles of a corresponding metal or metal oxide, and adhesion of a metal sheet can be used.
[0066]
Next, the adhesive layer and the toning adhesive layer will be described.
[0067]
Examples of the adhesive layer and the toning adhesive layer include hot melt adhesives such as ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, polyester, and polyamide, urethane-based, epoxy-based, and amino resin. Thermosetting or ultraviolet curable adhesives such as phenolic, phenolic and acrylate resins.
[0068]
From the simplicity of the manufacturing process, a hot-melt type adhesive (a film is also possible) or an ultraviolet curable type adhesive (the bonding process is performed in a short time without heating) is preferably used. Among these, an acrylic adhesive, for example, a solution-type or water-dispersion-type acrylate copolymer is preferably used because particularly good optical properties, heat resistance, moisture resistance, and the like are obtained.
[0069]
Colorants used for coloring the toning adhesive layer include dyes and pigments.As the dye, oil-soluble dyes such as azo, phthalocyanine, anthraquinone, and triallylmethane are preferably used, and Examples of the pigment include azo, phthalocyanine, anthraquinone, and quinacridone organic pigments. These colorants are used alone or in combination, and can perform color correction for cutting off extra wavelengths. The amount of the colorant used varies depending on the type, but in the case of a dye, it is about 0.01 to 1 part by weight per 100 parts by weight of an adhesive, and in the case of a pigment, it is about 0.01 to 10 parts by weight. It is about.
[0070]
As the near-infrared absorber added to the toning adhesive layer, a nitroso compound and a metal complex salt thereof, which are organic substances, a cyanine compound, a squarylium compound, a thiol nickel complex compound, a phthalocyanine compound, a naphthalocyanine compound, Triallylmethane compounds, immonium compounds, diimonium compounds, naphthoquinone compounds, anthraquinone compounds, or amino compounds, aminium salt compounds, or inorganic carbon black, indium tin oxide, antimony tin oxide, Periodic Table 4A And oxides, carbides, and borides of metals belonging to Group 5A or 6A. At least two of these are used. Further, it is preferable to use at least one kind of near-infrared absorber selected from an immonium-based compound, a diimonium-based compound, and an aminium salt-based compound. More preferably, at least one selected from the above-mentioned near-infrared absorbers other than the immonium compound, the diimonium compound and the aminium salt compound is used in combination.
[0071]
The near-infrared absorbing agent is mixed at a ratio of 0.1 to 60 parts by weight with respect to 100 parts by weight of the adhesive, and is adjusted to a solid concentration suitable for coating with an organic solvent or the like. The solid content concentration is preferably adjusted to a concentration of 5 to 50% by weight.
[0072]
Such a toning adhesive is usually used in the presence of an appropriate solvent, if necessary, an adhesive, a colorant, and a near-infrared absorber, using a general stirrer, a kneader, or the like, to obtain a colorant and a near-infrared ray. The absorbent is dissolved and dispersed, and the adhesive liquid is applied and dried on at least one layer constituting the PDP front impact absorbing sheet by a general coating means such as a blade coater or a roll coater. It is used so as to form a toning adhesive layer. It is also possible to use a hot melt type adhesive which has been formed into a film in advance. The thicknesses of the adhesive layer and the toning adhesive layer thus formed are generally preferably thinner. However, if the thickness is too small, a problem of the adhesive force occurs. On the other hand, if the thickness is too large, the light transmittance is reduced. The preferable thickness of the adhesive layer and the toning adhesive layer is about 10 μm to 1 mm.
[0073]
Further, an ultraviolet absorber may be added to the toning adhesive layer in order to improve the light resistance of the near infrared absorber. As the ultraviolet absorber to be added, salicylic acid esters, benzophenones, benzotriazoles, hydroxybenzoates, cyanoacrylates, and the like can be used. The amount of the ultraviolet absorber added is 0.3 to 30% by weight, preferably 0.3 to 10% by weight.
[0074]
In the infrared cut function, infrared rays from 800 nm to 1200 nm are the most problematic, and it is preferable to have a cut function in this region. In order to provide an infrared cut function, a method of mixing a near-infrared absorber with the above-described adhesive layer or the like, or a method of applying a solution or dispersion of these near-infrared absorbers can be used. Further, a method of forming a sputtered layer with silver is inexpensive and particularly preferable as a method of providing an infrared cut function in addition to an electromagnetic wave shielding function.
[0075]
Although the preferred embodiment has been described above, the PDP front impact absorbing sheet of the present invention may have any number of layers, such as anti-reflection or anti-glare, reduction of unnecessary radiation, infrared cut, and / or light transmittance. It preferably has an adjustment function.
[0076]
Further, the PDP front impact absorbing sheet of the present invention may be provided with a hard coat layer, a lubricating layer, an antifouling layer, an antistatic layer or an intermediate layer. The hard coat layer preferably contains a cross-linked polymer. The hard coat layer can be formed using an acrylic, urethane, epoxy, or siloxane-based polymer, oligomer, or monomer (eg, an ultraviolet curable resin). A silica-based filler can be added to the hard coat layer. A lubricating layer may be formed on the outermost surface of the anti-reflection or anti-glare film. The lubricating layer has a function of imparting a slipperiness to the antireflection or antiglare film surface and improving the scratch resistance. The lubricating layer can be formed using polyorganosiloxane (eg, silicone oil), natural wax, petroleum wax, higher fatty acid metal salt, fluorine-based lubricant or a derivative thereof. The thickness of the lubricating layer is preferably 0.002 to 0.02 μm. Alternatively, an antifouling layer can be provided on the outermost surface of the antireflection or antiglare film. The antifouling layer lowers the surface energy of the antireflection or antiglare film and makes it difficult to adhere to hydrophilic and lipophilic stains. Therefore, the antifouling layer is formed using a fluoropolymer. The thickness of the antifouling layer is 0.002 to 0.1 μm, preferably 0.005 to 0.03 μm.
[0077]
Various layers in the PDP front impact-absorbing sheet of the present invention, that is, an adhesive layer, an antireflection or antiglare film, a sputter layer, an adhesive layer, a toning adhesive layer, and the like can be formed by a general coating method. Examples of the coating method include a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method, and the like. Two or more layers may be formed by simultaneous coating. Further, as a method of forming a layer in the PDP front impact absorbing sheet of the present invention, a sputtering method, a vacuum deposition method, an ion plating method, a plasma CVD method, or a PVD method can be appropriately selected.
[0078]
The PDP front impact absorbing sheet of the present invention is used for an image display device such as a liquid crystal display (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), and a cathode ray tube display (CRT). In particular, a remarkable effect can be obtained by using the PDP front impact absorbing sheet of the present invention for a plasma display panel (PDP) and its PDP device.
[0079]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples. However, it is needless to say that the present invention should not be limitedly interpreted based on the description of the examples.
[0080]
(Example 1)
(1) Formation of electromagnetic wave and infrared cut layer (see FIG. 3)
An acrylic adhesive layer (adhesive layer 35A) was formed on the front side of a transparent silicon sheet (resin sheet 37) having a thickness of 50 μm. Further, a three-layer thin film of ZnO / Ag / ZnO (sputtering layer 36) was provided via the adhesive layer 35A by sputtering. The surface resistance of the three-layer thin film system was 5Ω / □, and the transmittance of infrared light having a wavelength of 800 nm or more was 20% or less.
[0081]
(2) Formation of anti-reflection or anti-glare filter
1.3 g of t-butanol was added to 2.50 g of a reactive fluoropolymer (JN-7219, manufactured by Nippon Synthetic Rubber Co., Ltd.), stirred at room temperature for 10 minutes, and filtered with a 1 μm polypropylene filter. The obtained anti-reflection or anti-glare filter coating solution is applied on the sputter layer 36 via an acrylic toning adhesive layer (toning adhesive layer 35B) with a dry coat thickness of 0.096 μm using a bar coater. And dried and cured at 120 ° C. for 15 minutes to form an anti-reflection or anti-glare filter 32.
[0082]
The toning adhesive used for the toning adhesive layer 35B was produced as follows. To 5 kg of the acrylate copolymer pressure-sensitive adhesive composition, 1.42 g of CI (Color Index) Solvent Red 111 (red oil-soluble dye) and 1.23 g of CI Solvent Blue 36 (blue oil-soluble dye) were added, The mixture was mixed with a kneader to obtain a toning adhesive.
[0083]
(3) Formation of adhesive layer
A pressure-sensitive adhesive surface of a 38 μm-thick polyethylene terephthalate film coated with a 25 μm-thick acrylic pressure-sensitive adhesive is closely adhered to the rear surface side of the resin sheet 37 and laminated to form an adhesive layer 30 having a protective film ( (Not shown), a PDP front impact absorbing sheet 31 of the present invention was produced.
[0084]
(Evaluation of PDP front impact absorbing sheet)
The front panel of the PDP (PDS4202J-H, manufactured by Fujitsu Ltd.) was removed, and the PDP front impact absorbing sheet prepared in Example 1 was attached to the PDP body with the adhesive layer 30 to produce a PDP device. Then, in the PDP front impact absorbing sheet of this embodiment, the front impact absorbing function, the reflectance, the electromagnetic wave and infrared ray shielding function, the measurement of the contrast of the displayed image, and the evaluation of the color reproducibility by visual observation were evaluated as evaluation items. went. The front shock absorption function achieved the same level as before the front panel was replaced. The reflectivity was 1.5% or less, and good results were obtained. The electromagnetic wave shielding function provided a minimum of 9 dB or more in the frequency range of 10 MHz to 200 MHz, and achieved the external leakage level of electromagnetic waves regulated by information processing devices and the like. In addition, the infrared region shielding function can be evaluated based on the low transmittance, which is about 8% at 800 nm and 3% or less at 850 nm, and can prevent interference with an infrared remote control device installed in the periphery. Contrast and visual color reproducibility were significantly improved. The contrast was 10: 1 before replacing the front panel, but was 15: 1 in Example 1. Before replacing the front panel, it was confirmed that orange with red was improved to pure red, greenish blue to vivid blue, and yellowish white to pure white.
[0085]
【The invention's effect】
As described above, according to the present invention, when adhered to the front surface of the PDP by the adhesive layer, the external impact is absorbed by the elastic adhesive layer and the elastic resin sheet, and the front glass of the PDP is absorbed. Can be protected. That is, since a heavy and expensive heat-treated glass is not required, the PDP device can be made inexpensive and lightweight. Further, since the heat-treated glass is eliminated, the number of external light reflecting surfaces is reduced, and reflected light is significantly reduced. Furthermore, since an adhesive layer is present between the PDP front impact absorbing sheet and the PDP, there is no air layer, so that there is no problem that a Newton ring appears and the displayed image becomes difficult to see. Therefore, a display image with good image quality can be obtained.
[0086]
Further, since the PDP front impact absorbing sheet can be directly adhered to the PDP, the step of applying an adhesive or the like can be omitted, so that the PDP device can be easily assembled.
[Brief description of the drawings]
FIG. 1 is a side view showing an example of an embodiment of a PDP device of the present invention.
FIG. 2 is a side view showing another example of the embodiment of the PDP device of the present invention.
FIG. 3 is a perspective view showing a configuration of a PDP.
4 is a configuration diagram showing a conventional PDP device provided with a protection plate on the PDP shown in FIG.
[Explanation of symbols]
1 front glass
2 Back glass
3 partition
4 Address electrode
5 phosphor
6 Display electrode
7 Dielectric layer
8 Protective film
11 PDP
12, 32, 52 Anti-reflective or anti-glare film
13 Heat treated glass
14, 34, 54 electrodes
15, 35, 55 adhesive layer
16, 36, 46 Sputtered layer
21 Protection plate
30, 40 adhesive layer
31, 41 PDP front impact absorption sheet
37, 57 resin sheet
50 coats

Claims (6)

A plasma display panel front impact absorbing sheet made of a laminate for protecting the plasma display panel,
One layer of the laminate is made of an elastic resin sheet,
An impact-absorbing sheet for a front surface of a plasma display panel, wherein an elastic adhesive layer is attached to one side of the resin sheet and is adhered to a front surface of the plasma display panel. 2. The shock absorbing sheet according to claim 1, wherein an elastic coat is provided on the opposite side of the resin sheet on which the adhesive layer is provided. 3. The plasma display panel front impact absorbing sheet according to claim 1 or 2, wherein the resin sheet is at least one selected from a silicone-based, a rubber-based, and a urethane-based resin. The plasma display panel front impact absorbing sheet according to any one of claims 1 to 3, wherein at least one layer of the laminate is an anti-reflection or anti-glare film. The plasma display panel front impact absorbing sheet according to any one of claims 1 to 4, wherein the laminate has at least one function of reducing unnecessary radiation, cutting off infrared rays, and adjusting light transmittance. A plasma display panel device using the plasma display panel front impact absorbing sheet according to claim 1.

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