JP2002260539A - Plasma display panel and plasma display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma display panel, on which an optical filter having an antireflection coating is given, and capable of improving impact resistance and the absorbing power of near-infrared radiation. SOLUTION: This plasma display panel is capable of increasing the breaking energy of impact test to not less than 0.5 joules by sticking a specified optical filter having an antireflection coating on the front surface of a panel via a specified adhesive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display in which an optical filter is attached to a front surface of a display to cut off near-infrared light emitted from the display and has excellent impact resistance.

[0002]

2. Description of the Related Art In recent years, the development of plasma displays (PDPs) for large thin televisions, thin display applications, and the like has been rapidly progressing and has already begun to appear on the market. However, since this plasma display emits near infrared rays due to its structure, it is necessary to block them. For this reason, various filters have already been developed.
JP-B-78509 discloses that 800 nm to 120 nm
A plasma display filter containing at least one near-infrared absorbing compound having a maximum absorption wavelength at 0 nm is disclosed, and JP-A-2000-258624 also discloses a filter capable of selectively cutting light of a specific wavelength. It has been disclosed. Also, JP-A-2000-25
No. 8626 discloses a filter for use by attaching to a front surface of a plasma display panel, in which a near-infrared absorbing layer is provided on a transparent resin base material and an adhesive layer is provided on the surface thereof. -299
No. 593 discloses an electromagnetic wave shielding filter having a plastic film adhesive layer.

[0003] On the other hand, as the size of plasma display devices increases, the weight and thickness of the plasma display devices are required to be reduced, and the impact resistance in a state in which a filter is provided is increasingly required.

[0004] However, in the prior art, sufficient impact resistance cannot be obtained in a state in which a filter is combined, and how to improve the impact resistance of a plasma display in which a filter is combined, Is a problem to be solved.

Further, in the prior art, it is common to include a near-infrared absorbing compound in an optical filter, and heating during resin molding may cause the near-infrared absorbing compound to deteriorate. There have been many problems to be solved, such as how to effectively perform neon light cutting (cutting of 595 nm light), which has become important.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, the present invention provides a plasma display panel incorporating a filter, which has an impact resistance of a specific value or more,
An object of the present invention is to effectively perform near-infrared cut and neon light cut.

[0007]

The present invention provides a plasma display panel comprising an optical filter having an anti-reflection film on the front surface of a display and an adhesive layer attached to the front surface of the display via an adhesive layer. 2. The plasma display panel according to claim 1, wherein the thickness of the pressure-sensitive adhesive layer is 0.5 to 2.0 mm, and (3) the base material of the optical filter is UL94 standard. 3. The plasma display panel according to claim 1, wherein the resin is a resin having flame retardancy of V-2 or more, and the thickness of the optical filter is 1.0 to 5.0 mm. The plasma display panel according to any one of claims 1 to 3, further comprising an antireflection film, (5) a pressure-sensitive adhesive layer containing a near-infrared absorbing compound. The plasma display panel according to any one of claims 1 to 4, (6) the plasma display panel according to any one of claims 1 to 5, wherein the adhesive layer contains a dye, and (7) the adhesive layer is attached to an optical filter. The plasma display panel according to any one of claims 1 to 6, wherein an optical filter having a pressure-sensitive adhesive layer is attached to a display, and (8) a layer containing a near-infrared absorbing compound and / or a dye. A plasma display panel according to any one of claims 1 to 7, and a plasma display device having the plasma display panel according to any one of claims 1 to 8. "

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is a plasma display panel in which an optical filter having an antireflection film on the front surface of a display is adhered via an adhesive layer.

The plasma display panel of the present invention includes a general plasma display panel component such as a glass substrate, a gas, an electrode, an electrode lead material, a thick-film printing material, and a phosphor, and a filter member including an adhesive layer. It is. By further combining the housings, a plasma display device is obtained. Two glass substrates, a front glass substrate and a rear glass substrate, are used. An electrode and a dielectric layer are formed on the two glass substrates, and a phosphor layer is formed on the rear glass substrate. A gas made of helium, neon, xenon, or the like is sealed between the two glass substrates. Then, an optical filter is attached to the front glass substrate via an adhesive layer.

[0010] The plasma display of the present invention is required to have a destruction energy by an impact test of 0.5 Joules or more. Preferably it is 1 joule or more. The test method is as follows.

When the display screen is kept horizontal on a plasma display panel set on a chassis via a heat transfer sheet and a steel ball (SUS) having a diameter of 20 mm is naturally dropped from a predetermined height, the plasma display panel is activated. It is required that the surface has no abnormality. The test can be performed by gradually increasing the height from the display screen, and the breaking energy can be calculated from the height when an abnormality occurs.

Usually, the plasma display panel is attached to a chassis made of aluminum via a heat transfer sheet. Although the breaking energy changes when the material of the heat transfer sheet is changed, it must be measured with the PDP set in the chassis. The present invention provides a plasma display panel having a destruction energy of 0.5 joules or more when set in a chassis portion irrespective of a change in the material of a heat transfer sheet.

The material of the pressure-sensitive adhesive layer of the present invention is not particularly limited as long as it achieves the object of improving the impact resistance and is suitable for containing a near-infrared absorbing compound or dye. For example, rubber-based adhesives such as natural rubber, styrene-butadiene rubber, neoprene, and butyl rubber, polymer-based adhesives such as alkyl acrylate, and various types of room-temperature-curable and heat-curable silicone resins can be used. An acrylic pressure-sensitive adhesive having good transparency is preferably used. As the acrylic pressure-sensitive adhesive, a relatively soft pressure-sensitive adhesive having a low glass transition temperature (10 ° C. or lower) is preferable. An ionomer resin obtained by cross-linking a metal ion with a (meth) acrylate copolymer can be suitably used for bonding at room temperature while maintaining transparency. Further, by adjusting the refractive index of the adhesive layer, a plasma display panel with higher transparency can be produced.

The thickness of the pressure-sensitive adhesive layer is determined from the viewpoint of impact resistance.
0.1 to 2.0 mm is preferable, and more preferably 0.5 to 2.0 mm.
２．０2.0 mm. Within this range, both excellent impact resistance and adhesiveness can be achieved.

In the present invention, the adhesive layer preferably contains a near infrared absorbing compound. In general, a near-infrared absorbing compound is unstable to heat, and may be deteriorated by heating when it is mixed with an optical filter made of a transparent resin substrate and molded. As near-infrared absorbing compounds, anthraquinone compounds, phthalocyanine compounds, naphthalocyanine compounds, metal oxide fine powder, immonium compounds, diimonium compounds, aminium salt compounds, thiourea compounds, bisthiourea compounds, squaric acid compounds And metal complex compounds. Cyanine dye, merocyanine dye, (thio) pyrylium dye, naphtholactam dye, pentacene dye, oxyindolizine dye, quinoid dye, aminium dye, diimmonium dye, indoaniline dye,
And nickel thio complex dyes.

It is preferable to add a dye to the adhesive layer. In particular, by cutting off the wavelength of 595 nm, which is called neon light, the color purity of red and the color reproducibility can be improved. Examples of the dye used in the present invention include cyanine compounds, oxonol compounds, triphenylmethane compounds, diphenylmethane compounds, xanthene compounds, oxazine compounds, xanthene compounds, and thiazine compounds. In addition, the contrast can be improved by neutralizing by using various dyes. Although it is not particularly limited, a dye having a small absorption of the three primary colors of light used in the PDP is preferable. For example, squarylium-based, cyanine-based, azo-based, azomethine-based, oxonol-based, benzylidene-based, and xanthene-based metrocyanine-based systems can be used. When a resin having a low glass transition temperature is used for the adhesive layer, it is easy to adjust a dye that better achieves the purpose of neon light cutting.

In the present invention, the optical filter may contain a near infrared absorbing compound or dye. Further, a layer containing a near-infrared absorbing compound and / or a dye may be provided separately from the optical filter and the pressure-sensitive adhesive layer. In this case, it is preferable to provide this layer between the optical filter and the pressure-sensitive adhesive layer. The layer containing the near-infrared absorbing compound and / or the dye includes a thermoplastic resin such as an acrylic resin, a polyester resin and a styrene resin, a thermosetting resin such as an epoxy resin and a polyurethane resin, and a polyfunctional such as an epoxy acrylate and a urethane acrylate. It is possible to use a thin film having, as a matrix component, a crosslinkable monomer, oligomer, or a cured product of a curable compound such as a silane compound such as tetraalkylsilane or a hydrolyzate thereof. These are preferably formed by applying a coating material containing the matrix component on a transparent substrate by a wet coating method such as a spin coating method, a die coating method, and a dipping method.

In the present invention, a pigment for color adjustment together with a dye or a pigment alone may be contained in an optical filter, an adhesive layer or a layer between the optical filter and the adhesive layer.

The optical filter constituting the present invention is made of a transparent base material, and may be any material such as glass or transparent resin that is substantially transparent and does not absorb or scatter light. There is no particular limitation as long as it is satisfactory. As glass, generally available glass such as soda glass and tempered glass can be used. Hard to break, light,
A transparent resin is preferably used because it is easy to process and easy to handle. The resin here is not particularly limited, but polymethacrylic acid-based resin, polycarbonate-based resin, polyester-based resin, polyolefin-based resin, and the like can be used.As a member of a plasma display panel, as long as it is distributed in the market, The flame retardancy preferably has a standard of V-2 or more.

The flame retardancy can be evaluated for five test pieces in accordance with the evaluation standard defined in UL94 for a test piece for evaluating 1/16 ″ thickness flame retardancy obtained by injection molding. The flame retardancy level is V-0>V-1> V
-2> HB.

As a resin satisfying V-2 and having excellent transparency, a polycarbonate resin is preferably used. The polycarbonate resin is obtained by reacting an aromatic dihydric phenol compound with phosgene or a carbonic acid diester. The aromatic homo- or copolycarbonate resin has a viscosity average molecular weight of 10,000 to 1,000,000
Are preferred. Here, as the dihydric phenol compound, 2,2-bis (4-hydroxyphenyl)
Propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4 -Hydroxyphenyl)
Butane, 2,2-bis (4-hydroxy-3,5-diphenyl) butane, 2,2-bis (4-hydroxy-3,
5-diethylphenyl) propane, 2,2-bis (4-
(Hydroxy-3,5-diethylphenyl) propane,
1,1-bis (4-hydroxyphenyl) cyclohexane, 1-phenyl-1,1-bis (4-hydroxyphenyl) ethane and the like can be used, and these can be used alone or as a mixture.

An anti-reflection film is formed on the optical filter constituting the present invention. By providing a visible light antireflection film on one or both surfaces of the transparent substrate, the reflectance in visible light can be efficiently suppressed. From the viewpoint of antireflection, the transparent substrate usually has at least one antireflection layer composed of a low refractive index layer and a high refractive index layer on at least one surface.
In the present invention, since the optical filter is attached to the front display via the adhesive layer, the object can be achieved if the antireflection layer is provided only on one side,
It can also contribute to cost reduction.

The antireflection film of the present invention is preferably composed of three layers of a low refractive index layer, a high refractive index layer, and a low refractive index layer from the substrate to the outside. It is only necessary to achieve the purpose described above. As another preferable example of the three layers, a medium refractive index layer is provided outward from the substrate, a high refractive index layer having a higher refractive index than the first layer, and a low refractive index layer having a lower refractive index than the middle refractive index layer. You can give what you have.

Examples of the material of a thin film called a low refractive index layer of the antireflection film include SiO ₂ , MgF ₂ , AlF ₃ ,
BaF ₂ , LiF, Na ₃ AlF ₆ , Na ₅ Al ₃ F ₁₄ , N
aF, SrF _{2 and the} like, and a single substance of these substances or a mixture containing one or more of these substances.
Among them, SiO ₂ and MgF ₂ are preferably used. Two or more thin films made of these substances may be stacked to form a low refractive index layer.

A thin film called a high refractive index layer of an antireflection film
The substance is ZrO_Two, TiO_Two, SiO, Y_TwoO_Three, Y
b_TwoO_Three, Sb_TwoO_Three, Sb_TwoO_Five, SnO_Two, In_TwoO_Three, I
TO, Ta_TwoO_Five, CeO_Two, MgO, HfO_Two, Pr
_TwoO_Three, Pr₆O₁₁, Bi_TwoO_Three, Cr _TwoO_Three, Eu_TwoO_Three, Fe
_TwoO_Three, La_TwoO_Three, MoO_Three, Nd_TwoO_Three, PbO, Sm_TwoO
_Three, Sc_TwoO_Three, ZnO, CaF_Two, SmF_Three, ZnS, G
e, Si, and the like.
Mixtures containing one or more of these substances are mentioned. in
Also ZrO_Two, TiO_Two, Ta_TwoO_Five, ZnO, ITO, Sn
O_Two, Y_TwoO_Three, MgO are preferably used. these
A high refractive index layer is formed by stacking two or more
You may. In the present invention, ITO refers to indium oxide
Is a mixture of aluminum oxide and tin oxide, and the mixing ratio is indium oxide to
90 to 95 to 10 to 5 tin oxide is preferred.

Examples of the material of the thin film called the middle refractive index layer of the antireflection film include Al ₂ O ₃ , WO ₃ , CeF ₃ , LaF ₃ ,
Examples thereof include NdF ₃ , PbF ₂ , and MgO, and a single substance of these substances or a mixture containing one or more of these substances. Among them, Al ₂ O ₃ is preferably used. In the case of the medium refractive index layer, a high refractive index substance and a low refractive index substance are often used as a mixture or as an equivalent film.
The equivalent film is, for example, a film having Al ₂ O ₃ is made of ZrO ₂ and S
Optically equivalent replacement with a combination of iO ₂ films. That is, a medium-refractive-index layer may be formed by combining two or more layers of a thin-film forming a high-refractive-index layer and a thin-film forming a low-refractive-index layer.

In the present invention, the preferred structure of the antireflection film is as follows: from the side of the transparent substrate, “the low refractive index layer is composed of a SiO ₂ film layer, the high refractive index layer is composed of an ITO film layer, and the low refractive index layer is composed of SiO ₂ made of film layer ", SiO ₂ film layer counted" medium refractive index layer from the transparent substrate side, ZrO ₂ layer, SiO ₂
The high-refractive-index layer is counted from the substrate side and has a T
iO ₂ film layer made of two layers of ITO film layer, those having a low refractive index layer made of SiO ₂ film layer ", SiO ₂ film layer counted" medium refractive index layer from the transparent substrate side, the ITO film layer, three layers of SiO ₂ film layer, the high refractive index layer is made of an ITO film layer, those having a low refractive index layer made of SiO ₂ film layer ", SiO ₂ counted" medium refractive index layer from the transparent substrate side Film layer, ZrO ₂ film layer, Si
O ₂ a three-layered structure including the film layer, the high refractive index layer is made of TiO ₂ layer, a low refractive index layer is made of SiO ₂ film layer "and the like.

With such a structure, SiO ₂ ,
By using a general and inexpensive deposition material such as ZrO ₂ or TiO ₂ , reflection from external light can be suppressed to be low over a wide wavelength range, and the luminous reflectance can be reduced. Also, IT
By using O, conductivity can be imparted, electric field cut,
Functions such as static electricity prevention can be added.

For the formation of the anti-reflection film, a usual method such as a vacuum deposition method, a sputtering method, an ion plating method and the like can be used.

When the transparent substrate of the optical filter constituting the present invention is made of a resin, it is preferable to apply a hard coat for preventing damage. As the hard coat, a heat-curable organopolysiloxane-based hard coat or an ultraviolet-curable acrylic hard coat is preferable. More preferably, when a hard coat having a refractive index equal to the refractive index of the substrate is used, an optical filter in which interference fringes are hardly seen is obtained.

Further, it is preferable to apply a water-repellent treatment to the outermost layer of the antireflection film in order to prevent contamination. Examples of the water-repellent processing include a wet method and a vacuum evaporation method. Among them, when the antireflection processing is performed by the vacuum evaporation method, the processing is preferably performed by the vacuum evaporation method from the viewpoint of production efficiency.

The thickness of the optical filter of the present invention is preferably 0.5 to 5.0 mm, more preferably 1.0 to 5.0 mm, from the viewpoint of achieving both impact resistance and thinning.

In the present invention, there is no particular limitation on the method of attaching the optical filter portion to the front surface of the display via the adhesive layer. A method of pasting an adhesive layer on the display first,
Any of a method of first attaching the pressure-sensitive adhesive layer to the optical filter and a method of simultaneously attaching the display, the pressure-sensitive adhesive layer and the optical filter can be adopted. However, it is preferable to attach the optical filter to the display first, and then attach the optical filter to the display via the pressure-sensitive adhesive layer. When the optical filter is attached to the display via the pressure-sensitive adhesive layer, there is a possibility that air bubbles causing defective products are generated. Since the defective product after attaching to the display adversely affects the production efficiency, it is preferable to first attach the optical filter to the optical filter side and minimize the adverse effect in the event that a defective product occurs.

In the present invention, it is also possible to provide a plurality of optical filters and a plurality of pressure-sensitive adhesive layers. As an example, the adhesive layer, optical filter, adhesive layer,
It is a combination of optical filters. In this case, the antireflection layer may be provided on at least one of the optical filters. The thickness of each of the plurality of optical filters is preferably 0.5 to 5.0 mm, and the thickness of the plurality of pressure-sensitive adhesive layers is preferably 0.1 to 2 mm.

[0035]

EXAMPLES The present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.
The antireflection performance and near-infrared blocking performance were measured with a spectrophotometer (U-3410, manufactured by Hitachi, Ltd.).

Example 1 A partially hydrolyzed γ-glycidoxypropylmethyldiethoxysilane and a bisphenol A type epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd.) were applied on both sides of a transparent polycarbonate resin plate having a thickness of 3 mm by an immersion method. Product name "Epicoat"
827) and methanol silica sol (particle size: about 13 nm)
And a 5 μm-thick hard coat film containing 5 wt% of an ultraviolet absorber (trade name “Tinuvin” 326 manufactured by Ciba Geigy Co., Ltd.) with respect to the main component. On one side of the hard coat film, a 95 nm-thick S
SiO ₂ film, ITO film with a thickness of 62 nm, S film with a thickness of 95 nm
An anti-reflection film made of an iO ₂ film was formed, and an optical filter with an anti-reflection film was obtained. The antireflection performance was 0.5%.

Next, in order to attach the optical filter to the front surface of the PDP panel, n-butyl acrylate: 78.4% by weight, 2-ethylhexyl acrylate: 19.6% by weight, and acrylic acid: 2 .0
Acrylate copolymer 10 copolymerized by weight%
With respect to 0 parts by weight, zinc salt of acetylacetone: 0.5 parts by weight and aluminum salt of acetylacetone:
After melt-stirring 0.7 parts by weight, 0.03 parts by weight of a near-infrared absorbing agent [0.05 parts by weight (trade name “E-X Color” TX-EX-805K manufactured by Nippon Shokubai Co., Ltd.), and ( Nippon Carlit Co., Ltd. product name "CIR-
1080 ") 0.015 parts by weight] and 0.0001 part by weight of a dye (trade name" PS Blue BN "manufactured by Mitsui Chemicals, Inc.), and a pressure-sensitive adhesive sheet formed into a sheet with a predetermined thickness (0.5 mm). Using.

The above adhesive sheet was attached to an optical filter and then attached to a plasma display. The obtained PDP panel did not generate air bubbles or peel off the filter. The obtained PDP panel was made to have a silicon-based thickness of 1.8.
Combined with an aluminum chassis used for a 42-inch commercial display device via a heat transfer sheet,
The S ball was dropped on the surface to test the impact resistance. 0.
There were no cracks or cracks in the PDP panel against an impact of 5 joules. The near-infrared shielding performance in a state where the pressure-sensitive adhesive sheet was stuck to the filter was 85% or more at a wavelength of 800 to 1200 nm.

Example 2 A γ-glycidoxypropylmethyldiethoxysilane partially hydrolyzed product and a bisphenol A type epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd.) were applied on both sides of a transparent polycarbonate resin plate having a thickness of 3 mm by an immersion method. Product name "Epicoat"
827) and methanol silica sol (particle size: about 13 nm)
As a main component, and 4 wt% of a near-infrared absorber based on the main component
[(Nippon Shokubai Co., Ltd., product name "E EX Color" T
X-EX-805K) 2 wt%, and (Nippon Carlit Co., Ltd. product name "CIR-1080") 2 wt%],
Dye (trade name “PS Blue BN” manufactured by Mitsui Chemicals, Inc.)
A film thickness 3 containing 0.01 wt% and 5 wt% of an ultraviolet absorber (trade name “Tinuvin” 326 manufactured by Ciba Geigy Co., Ltd.)
A μm hard coat film was formed. On one side of the hard coat film, SiO ₂ film having a thickness of 95nm by vacuum deposition, ITO film having a thickness of 62 nm, to form an antireflection film made of SiO ₂ film having a thickness of 95nm, the anti-reflection film to shield near infrared rays An optical filter was obtained. Anti-reflection performance is 0.5
%, Near-infrared shielding performance was 85% or more at a wavelength of 800 to 1200 nm.

Next, in order to attach the above filter to the front surface of the plasma display, the distance between the display and the filter was maintained at 1 mm, and the transparent thermosetting silicone (trade name “S” manufactured by Dow Corning Toray Silicone Co., Ltd.) was used.
Using E1740A / B ″), heat treatment was performed at 70 ° C. for 30 minutes to perform bonding. The resulting PDP panel did not show generation of air bubbles or separation of the filter.
The DP panel was combined with a 42-inch aluminum chassis used for a commercially available display device via a silicon-based heat transfer sheet having a thickness of 1.8 mm, and a predetermined SUS ball was dropped on the surface to test impact resistance. . There was no crack or crack in the PDP panel against a shock of 0.5 joule.

COMPARATIVE EXAMPLE 1 Instead of the optical filter of Example 1, the thickness was 188 μm.
The PET film was bonded by using a silicone-based adhesive, and an impact of 0.3 Joule was naturally dropped on the SUS sphere. As a result, the PDP panel was broken.

[0042]

As described above, by adopting the structure of the present invention, a plasma display panel incorporating a filter has an impact resistance of a specific value or more, and is effective in cutting near infrared rays and neon light. Can be done.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G09F 9/00 313 G02B 1/10 Z F term (reference) 2H048 CA04 CA12 CA19 2K009 AA05 AA06 AA15 CC03 CC24 CC42 DD03 DD04 5C040 FA10 GH10 MA04 MA08 MA09 5G435 AA00 BB06 DD12 FF01 GG11 HH03 KK07

Claims (9)

[Claims] 1. A plasma display panel in which an optical filter having an antireflection film on the front surface of a display is adhered via an adhesive layer, wherein the destruction energy by an impact test is 0.5 joules or more. 2. The plasma display panel according to claim 1, wherein the pressure-sensitive adhesive layer has a thickness of 0.5 to 2.0 mm. 3. The base material of the optical filter is UL94 standard V
The plasma display panel according to claim 1, wherein the resin is a resin having a flame retardancy of −2 or more, and the thickness of the optical filter is 1.0 to 5.0 mm. 4. The plasma display panel according to claim 1, wherein the optical filter has an antireflection film only on one side. 5. The plasma display panel according to claim 1, wherein the pressure-sensitive adhesive layer contains a near-infrared absorbing compound. 6. The plasma display panel according to claim 1, wherein the pressure-sensitive adhesive layer contains a dye. 7. The plasma display panel according to claim 1, wherein the pressure-sensitive adhesive layer is attached to an optical filter, and then the optical filter is attached to the display via the adhesive layer. 8. The plasma display panel according to claim 1, wherein a layer containing a near infrared absorbing compound and / or a dye is provided between the optical filter and the pressure-sensitive adhesive layer. 9. A plasma display device comprising the plasma display panel according to claim 1.