JPH10186128A - Front surface plate for plasma display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a front surface plate for a plasma display which shields electromagnetic waves and simultaneously has excellent visibility by including a conductive layer into an antireflection layer. SOLUTION: The one surface of a transparent substrate provided with the antireflection layer including the conductive layer and another surface is provided with the antireflection layer. The conductive layer included in the antireflection layer includes metal oxide thin films consisting of zinc oxide, tin oxide, indium oxide, etc., and metallic thin films consisting of silver, gold, copper, aluminum, etc. The thin films which are transparent and have low electric resistance are recommended. The thin film contg. the indium oxide and/or tin oxide is more preferable. The antireflection layer including the conductive layer is formed by combining the conductive layer and magnesium fluoride, silicon oxide, titanium oxide, tantalum oxide, tin oxide, indium oxide, zirconium oxide, zinc oxide, etc. Above all, the layer formed by combining a layer (ITO layer) consisting of the indium oxide and tin oxide and a layer consisting of the silicon oxide is preferable. A hard coating layer may be directly formed on the transparent substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is installed on the front of a plasma display used as a large screen flat display, and has excellent antireflection performance and electromagnetic wave shielding performance.
Further, the present invention relates to a light-transmitting front plate having near-infrared shielding performance.

[0002]

2. Description of the Related Art A front plate of a display has an anti-reflection property for the purpose of preventing blurring of a screen due to reflection of illumination light or a background, protection of a display surface, and prevention of dirt on a display surface. Various products having scratch resistance and stain resistance have been proposed. On the other hand, the plasma display has attracted attention as a large-screen flat display that has never been seen before, but there is a concern that electromagnetic waves generated from the screen and its surroundings may affect the human body. As a method of shielding electromagnetic waves of a display, Japanese Patent Publication No. Hei 6-91340 proposes a method of using a fiber net having a metalized filament surface.

[0003]

However, a display front panel having antireflection properties, scratch resistance and antifouling properties conventionally proposed cannot shield electromagnetic waves generated from the screen and its surroundings. In addition, the method using a fiber mesh having a metalized filament surface is extremely excellent in electromagnetic wave shielding performance, but has problems such as generation of moire and reduction in visibility. Therefore, the present inventors have screened and electromagnetic waves generated from the surroundings, and excellent antireflection properties, that is, as a result of intensive study on the front panel for plasma display excellent in visibility, as a result of including a conductive layer in the antireflection layer By doing so, it has been found that a front panel for a plasma display having excellent visibility can be obtained at the same time as shielding electromagnetic waves.

[0004]

That is, the present invention provides a plasma display characterized in that an antireflection layer including a conductive layer is provided on one surface of a transparent substrate, and an antireflection layer is provided on the other surface. It is a front plate for use. Hereinafter, the present invention will be described in detail.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The front plate of the present invention is a film or a sheet attached to the front of a plasma display. The size of the front plate is arbitrarily selected according to the display screen size of the plasma display. Although the thickness can be arbitrarily selected, it is generally about 0.01 to 10 mm.

The transparent substrate in the present invention is made of acrylic resin, polycarbonate resin, polystyrene, MMA
-A resin plate such as a styrene copolymer resin may be used, but an acrylic resin plate is preferable because of ease of processing. The transparent substrate of the present invention has a light transmittance of 50% at a wavelength of 400 to 600 nm.
The above is used. The front panel for a plasma display preferably blocks near infrared rays generated from a screen, and preferably has a transmittance of 20% or less at a wavelength of 850 to 1000 nm.

The front plate for a plasma display of the present invention may be a resin composition having near-infrared shielding performance on a substrate having no near-infrared shielding performance, or a substrate having no near-infrared shielding performance. May be formed. Examples of the resin composition having near-infrared shielding performance include the following. (1) It contains a monomer having an unsaturated double bond, a copolymer obtained by copolymerizing a phosphorus atom-containing monomer, and a copper atom as disclosed in JP-A-6-118228. A resin composition containing a compound. (2) A resin composition containing a copper compound and a phosphorus compound as described in JP-B-62-5190. (3) A resin composition containing a copper compound and a thiourea derivative as described in JP-A-6-73197. (4) A resin composition containing a tungsten compound as described in US Pat. No. 3,647,729.

[0008] The surface of the transparent substrate, particularly the surface that is likely to be in contact with humans during use, is easily damaged. Therefore, it is preferable to increase the hardness of the surface by forming a hard coat layer on the surface. Known hard coat layers used for this purpose are used as the hard coat layer. For example,
A cured film obtained by polymerizing and curing a coating agent containing a polyfunctional monomer as a main component can be given. Specifically, urethane (meth) acrylate, polyester (meth) acrylate, polyether (meth)
A layer obtained by polymerizing and curing a polyfunctional polymerizable compound containing two or more acryloyl groups or methacryloyl groups such as acrylates by activation energy rays such as ultraviolet rays and electron beams; or a silicon-based, melamine-based, or epoxy-based crosslinkable resin A material obtained by crosslinking and curing a material by heat can be used.

As a method for forming a hard coat layer, first, a coating agent is used in a usual coating operation, that is, a spin coating method, a dip coating method, a roll coating method, a gravure coating method, a curtain flow coating method. And the like.

Subsequently, the composition is cured by a method corresponding to the coating agent used. At this time, the coating agent may be diluted with various solvents in order to facilitate coating or to adjust the thickness of the coating film. Curing of the applied coating agent is performed by thermal polymerization in which the temperature is increased by heating, or photopolymerization by irradiation with an active energy ray such as an ultraviolet ray or an electron beam.

The thickness of the hard coat layer is not particularly limited, but is preferably 1 to 20 μm. If it is less than 1 μm, a light interference pattern appears due to the influence of the upper antireflection layer,
Not desirable in appearance. On the other hand, if the thickness exceeds 20 μm, the coating film is undesirably strong, such as cracks.

In order to improve the adhesion between the transparent substrate and the hard coat layer, an adhesive layer may be provided between the transparent substrate and the hard coat layer. The adhesive layer may be a known one used for this purpose.

In the front plate of the present invention, antireflection layers are provided on both surfaces of a transparent substrate for improving visibility. An antireflection layer including a conductive layer is provided on one surface to improve visibility and shield electromagnetic waves.

As the conductive layer contained in the antireflection layer, a metal oxide thin film such as zinc oxide, tin oxide, and indium oxide;
A metal thin film of silver, gold, copper, aluminum or the like can be considered, but a transparent thin film having a low electric resistance is preferable, and a film containing indium oxide and / or tin oxide is preferable.

The anti-reflection layer including the conductive layer is formed by combining the above-described conductive layer with magnesium fluoride, silicon oxide, titanium oxide, tantalum oxide, tin oxide, indium oxide, zirconium oxide, zinc oxide and the like. . Among them, a combination of a layer made of indium oxide and tin oxide (ITO layer) and a layer made of silicon oxide is preferable because of its excellent conductivity, surface hardness, adhesion, and economy.

The anti-reflection layer including the conductive layer also serves to prevent dust from adhering to the surface due to charging, and is preferably formed on the outermost side of the display screen. On the side surface. As described above, the antireflection layer including the conductive layer is formed on the outside where there is a high possibility of contact with humans, and thus is preferably formed on a hard coat.

In the front plate for a plasma display of the present invention, the antireflection layer formed on the surface opposite to the antireflection layer including the conductive layer is made of a low refractive index substance such as magnesium fluoride or silicon oxide and titanium oxide. , Tantalum oxide, tin oxide,
Multi-layer anti-reflective coating combining high refractive index materials such as indium oxide, zirconium oxide, zinc oxide, or single-layer anti-reflective coating mainly composed of low-refractive index substance, and adhesive layer and surface for improving its adhesion and hardness Although a product having a modified layer is considered, an antireflection layer using magnesium fluoride as a low refractive index layer is preferably used from the viewpoint of ease of processing and antireflection performance.

Since this antireflection layer is used on the display screen side of a plasma display, it is required that the antireflection layer be excellent in durability against temperature change due to heat from the screen, such as aluminum oxide, magnesium fluoride, and silicon oxide. It is preferable to use three layers.

The anti-reflection layer including the conductive layer of the present invention and the anti-reflection layer formed on the surface opposite to the anti-reflection layer are formed by a known method such as coating, vacuum deposition, sputtering, and ion plating.

In the front plate for a plasma display of the present invention, an antireflection layer containing a conductive layer, an antireflection layer, or a hard coat layer may be formed directly on a transparent substrate,
A transparent film with an anti-reflection layer containing a conductive layer formed on the surface, a transparent film with an anti-reflection layer formed on the surface, or a transparent film with a hard coat layer and an anti-reflection layer containing a conductive layer formed on the transparent film May be formed by sticking on a transparent substrate.

[0021]

The front panel for a plasma display of the present invention is integrally mounted in front of the plasma display to improve the visibility and to improve the electromagnetic wave,
Further, it is suitable for shielding near infrared rays and preventing adverse effects on human bodies and peripheral devices.

[0022]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. In addition, the evaluation method is as follows. (1) Light transmittance: 400 to 100 of the obtained sample
The spectral transmittance in the range of 0 nm was measured by using a self-recording spectrophotometer model 330 manufactured by Hitachi, Ltd. (2) Visibility: The front panel obtained on the front of the 20-inch plasma display was attached and viewed through, and the difference between the color and the contour of the image before the attachment was confirmed. (3) Electromagnetic shielding performance: shielding material evaluation system R2
Evaluation was performed using Model 547 (manufactured by Advantest Corporation). (4) Near-infrared shielding performance: (Remote control test) Install the front panel obtained in front of the remote control light receiving unit of the home TV,
A remote control signal (signal wavelength of 950 nm) was sent from a remote controller at a distance of m from the remote controller, and it was confirmed whether or not a reaction occurred. The near-infrared ray generated from the display is weaker than that generated from the remote controller, so if this test does not respond, it is possible to prevent the remote control from being damaged by the near-infrared ray generated from the display.

Example 1 (1) Preparation of Transparent Substrate 100 parts by weight of a mixture composed of 45% by weight of methyl methacrylate, 25% by weight of isobornyl methacrylate, and 30% by weight of polyethylene glycol (average molecular weight: 200) dimethacrylate were added with the following chemical formula. 4 parts by weight of the phosphorus atom-containing compound represented by Chemical Formula 1 and 10 parts by weight of the phosphorus atom-containing compound represented by Chemical Formula 2 were added. 5 parts by weight of copper benzoate anhydride as a copper atom-containing compound, and t-butyl peroxy-2-ethylhexanoate 0.1 as a radical polymerization initiator.
5 parts by weight were dissolved. This solution was poured into a polymerization cell consisting of a 3 mm-thick polyvinyl chloride gasket and two glass plates of 620 × 420 × 10 mm, and heated and polymerized at 50 ° C. for 12 hours and at 100 ° C. for 2 hours to obtain a size of 600 × 40
A plate-like near-infrared absorbing material having a thickness of 0 mm and a thickness of 3 mm was obtained.
This was used as it was as a front panel. The visibility was good. Table 1 shows the light transmittance of this transparent substrate.

[0024]

Embedded image CH ₂ CC (CH ₃ ) COO—CH ₂ CH ₂ OP (O) (OH) ₂

[0025]

Embedded image [CH ₂ CHC (CH ₃ ) COO-CH ₂ CH ₂ O] ₂ P (O) -OH

(2) Preparation of antireflection film including conductive layer PET film (188 μm thick) subjected to hard coating treatment
m: manufactured by Toyobo) by DC magnetron sputtering using indium oxide-tin oxide (ITO), silicon oxide, IT
O and silicon oxide were sequentially laminated to form an anti-reflection layer containing ITO. At this time, the surface resistivity of the ITO layer is 180
Ω / □.

(3) Preparation of antireflection film Aluminum oxide, magnesium fluoride, and PET film (thickness: 188 μm, manufactured by Toyobo) were vacuum-deposited.
Silicon oxide was sequentially stacked to form an antireflection layer.

(4) Preparation of Front Panel for Plasma Display One side of the transparent substrate obtained in the above (1) is laminated with the antireflection film containing the conductive layer obtained in the above (2), and The antireflection film obtained in the above (3) was bonded to obtain a front panel for a plasma display. This front plate was mounted on the front surface of the plasma display with the antireflection layer including the conductive layer facing outside. This front panel was light blue in transmission color, had a very beautiful appearance, and had very few reflected images. The front panel did not respond in the remote control test. Further, the tobacco ash was brought close to the front plate, but the ash did not adhere. Table 1 shows the light reflectance of the front plate, and Table 2 shows the electromagnetic wave shielding performance.
It was shown to.

Comparative Example 1 The front substrate for a plasma display was obtained by laminating the antireflection film obtained in (3) on both sides of the transparent substrate obtained in (1). This front plate was mounted on the front of the plasma display. This front plate had a good appearance, had little reflected image reflection, and was good in appearance, but had no electromagnetic wave shielding performance at all. Table 2 shows the electromagnetic wave shielding performance of this front plate.

[0030]

[Table 1]

[0031]

[Table 2]

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01J 17/16 G02B 1/10 Z

Claims (10)

[Claims] 1. A front panel for a plasma display, wherein an anti-reflection layer including a conductive layer is provided on one surface of a transparent substrate, and an anti-reflection layer is provided on the other surface. 2. The front plate for a plasma display according to claim 1, wherein the conductive layer is a layer containing indium oxide and tin oxide. 3. The front panel for a plasma display according to claim 1, wherein a hard coat layer is provided on the transparent substrate, and an antireflection layer including a conductive layer is provided thereon. 4. The front plate for a plasma display according to claim 1, wherein an anti-reflection layer including a conductive layer is formed on a surface of the transparent substrate opposite to a display surface of the plasma display. 5. The front plate for a plasma display according to claim 1, wherein the antireflection layer formed on the surface of the transparent substrate opposite to the antireflection layer including the conductive layer is an antireflection layer including magnesium fluoride. . 6. The anti-reflection layer formed on the surface of the transparent substrate opposite to the anti-reflection layer including the conductive layer is an anti-reflection layer composed of three layers of aluminum oxide, magnesium fluoride and silicon oxide. Item 2. A front panel for a plasma display according to Item 1. 7. The front plate for a plasma display according to claim 1, wherein the transparent substrate has an average light transmittance of 20% or less at a wavelength of 850 to 1000 nm. 8. The front plate for a plasma display according to claim 1, wherein the transparent substrate is a resin plate containing an acrylic resin as a main component. 9. The front plate for a plasma display according to claim 1, wherein the transparent substrate is a resin plate containing a polycarbonate resin as a main component. 10. The front plate for a plasma display according to claim 1, wherein the transparent substrate is a resin plate containing a polystyrene resin as a main component.