JP2001215320A - Optical filter and display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical filter that coloring of the substrate due to UV rays is little even when the filter is used for a long time, so that there is little fear that the visibility is reduced as a whole. SOLUTION: The optical filter 2 has at least a transparent substrate 22 made of a polymerized material containing an alicyclic structure. The filter has >= 60% light transmittance at 365 nm wavelength before irradiation of UV rays and shows >=5% reduction in the light transmittance at 365 nm wavelength after the filter is irradiated with UV rays of 2000 mJ/cm2 energy for 24 hours. The filter preferably has a UV-absorbing layer 24 into which an UV absorbent is compounded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, an optical filter used in front of a plasma display panel (PDP) and a display device using the same.

[0002]

2. Description of the Related Art Recently, a plasma display panel (PDP) has attracted attention as a large-sized flat display device, and the PDP is a conventional cold cathode ray tube (CR).
T) and a liquid crystal display panel (LCD), etc., have higher strength of electromagnetic waves leaking from the front surface, and therefore, it is strongly required to have an excellent electromagnetic wave shielding function. In the PDP, near-infrared rays originating from the emission of inert gas in the cell are also emitted from the front surface, but the wavelength of the near-infrared rays is close to the operating wavelength of remote control devices of various home appliances, which may cause malfunction. Therefore, it is also required to have a function of sufficiently shielding near infrared rays. Further, it is naturally required that this type of display panel such as a PDP has an anti-reflection function and an anti-glare function from the viewpoint of improving image quality and visibility.

However, since it is extremely difficult to provide all these various functions to the panel itself, various functions such as the above-mentioned electromagnetic wave shielding function, near-infrared absorption function, anti-reflection function, and anti-glare function are provided. Conventionally, a method of appropriately disposing an optical filter provided on a transparent substrate on the front surface of a display panel has been adopted.

[0004]

A glass substrate has been used as a transparent substrate as a component of an optical filter. However, in recent years, there has been a demand for weight reduction and improvement in impact resistance, and replacement with a plastic substrate has been required. Are being considered. However, when acrylic resin (especially PMMA), polycarbonate, polyethylene terephthalate, or the like, which is generally used as a transparent plastic, is used as a plastic material constituting the plastic substrate, there is a problem that warpage due to moisture absorption occurs. .

On the other hand, Japanese Patent Application Laid-Open Nos. 11-77909 and 11-163587 propose a norbornene-based resin as a transparent plastic material suitable for optical applications such as lenses and optical disks. Describes that a norbornene-based resin can be used as a plastic material for forming a transparent substrate of a filter for PDP.

However, according to studies by the present inventors, an alicyclic structure-containing polymer such as a norbornene resin may be slightly colored (= decreased in transparency) when exposed to ultraviolet light for a long time. In addition, it has been found that ultraviolet light is also emitted from PDP, so that it cannot be used as it is as a transparent substrate of a filter for PDP.

[0007] It is an object of the present invention to provide an optical filter and a display device using the same, in which the substrate is less likely to be colored by ultraviolet rays even when used for a long time, and as a result, the overall visibility is less likely to be reduced. It is in.

[0008]

In order to achieve the above object, an optical filter according to the present invention is an optical filter having at least a transparent substrate made of an alicyclic structure-containing polymer, and has a wavelength before irradiation with ultraviolet light. The light transmittance at 365 nm is 60% or more, and 2000 mJ / cm ²
Of the light transmittance at a wavelength of 365 nm after irradiation with the ultraviolet ray for 24 hours is 5% or less.

[0009] The specific structure of the optical filter according to the present invention is not particularly limited, and even if the transparent substrate contains a predetermined amount of an ultraviolet absorber, the optical filter may be directly or otherwise formed on the transparent substrate. It may be a configuration in which an ultraviolet absorbing layer is laminated via a layer, or may be a configuration in which these are combined, but preferably, a predetermined amount of an ultraviolet absorbing agent is blended in the transparent substrate, Moreover, the structure is such that an ultraviolet absorbing layer is laminated on the transparent substrate directly or via another layer. In any case, it is desirable to blend the ultraviolet absorber so that the ultraviolet transmittance is preferably 5% or less, more preferably 3% or less, and still more preferably 2% or less.

The optical filter according to the present invention has various functions such as an electromagnetic wave shielding function, a near-infrared absorption function, an anti-reflection function, an anti-glare function, an anti-scratch function, and an anti-pollution function, in addition to the above-described ultraviolet absorption function. Is preferably provided. When the electromagnetic wave shielding function is provided,
Electromagnetic waves are effectively prevented from reaching the operator. When the near-infrared absorption function is provided, malfunction of remote control devices of various home appliances is effectively prevented.
When an anti-reflection function or an anti-glare function is provided, reflection by external light is prevented, and image quality and visibility are improved.
When the anti-scratch function is provided, the surface of the filter is effectively prevented from being scratched. When the antifouling function is provided, it is possible to prevent the adhesion of dirt due to hand marks, fingerprints, cosmetics, and the like, and to easily remove the adhering dirt.

[0011] The optical filter according to the present invention includes a plasma display panel (PDP) and a liquid crystal display (L).
CD), organic electroluminescence (EL) display, field emission type (FED) display, flat display such as light emitting diode (LED); curved display such as cathode ray tube; Although it is possible, it is particularly suitable as a front panel of a PDP. Further, when a specific structure of the optical filter according to the present invention adopts a configuration in which an ultraviolet absorbing layer is laminated on a transparent substrate, by disposing the ultraviolet absorbing layer so as to face the display panel side, a display is provided. Even if light is emitted (including the case where light is emitted indirectly using a backlight or the like), there is little risk that the transparent substrate constituting the optical filter will be colored (= transparency is reduced) by the ultraviolet light generated therefrom. As a result, a decrease in the visibility of the display is effectively prevented.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An optical filter according to the present invention comprises:
The light transmittance at a wavelength of 365 nm before UV irradiation is 6
0% or more (preferably 70% or more, more preferably 80% or more)
A% or higher), 2 with ultraviolet rays at 2000 mJ / cm ²
The rate of decrease in light transmittance at a wavelength of 365 nm after irradiation for 4 hours is 5% or less (preferably 4% or less, more preferably 3% or less). However, the irradiation time of ultraviolet rays is 2
In the case of 40 hours, the reduction rate is 7.5% or less, preferably 5.5% or less, more preferably 5% or less, and in the case of the irradiation time of 2400 hours, the reduction rate is 10% or less, preferably It is at most 7.5%, more preferably at most 5%.

The size of the optical filter according to the present invention is as follows:
There is no particular limitation, and it can be arbitrarily selected according to the screen size of the display to be applied. Although the thickness of the optical filter can be arbitrarily selected, it is usually 0.1 to 10 mm, preferably 1 to 10 mm.
About 5 mm.

An example of a specific structure of the optical filter according to the present invention will be described with reference to FIG. FIG. 1 is a sectional view showing an embodiment of the optical filter according to the present invention.

As shown in FIG. 1, an optical filter 2 according to the present embodiment is disposed on a side of an image display surface (glass substrate) 62 of a PDP unit 6 as an example of a display element via a predetermined space. However, they may be arranged in close contact with the image display surface 62. In any case, the optical filter 2 and the PDP unit 6 constitute a PDP device (an example of a display device) of the present invention. The PDP unit 6, for example, emits light in the visible light region by exciting phosphors applied in the tube by ultraviolet rays generated by discharge-exciting xenon gas molecules sealed in the tube to emit light in the visible light region. An image can be formed by emitting a desired amount of phosphor at a desired position at a desired timing in accordance with an image signal. Note that the symbol “X” in FIG.
Indicates the viewing direction of the operator.

The optical filter 2 according to the present embodiment has a transparent substrate 22 made of a polymer having an alicyclic structure, and a side of the transparent substrate 22 facing the PDP unit 6 includes:
An ultraviolet absorbing layer 24 is formed. The optical filter 2 is provided with an electromagnetic wave shielding function (electromagnetic wave shielding layer 26), a near infrared absorbing function (near infrared absorbing layer 28), and an antireflection function (antireflection layers 29a and 29b). Other functions such as a prevention function (hard coat layer, not shown) may be provided.

Transparent Substrate 22 The transparent substrate 22 is made of an alicyclic structure-containing polymer.

The alicyclic structure-containing polymer which can be used in the present invention has an alicyclic structure in the main chain and / or the side chain. From the viewpoint of transparency and heat resistance, the main chain has an alicyclic structure. Those containing a cyclic structure are preferred.

Examples of the alicyclic structure of the polymer include a cycloalkane structure and a cycloalkene structure. From the viewpoints of mechanical properties and heat resistance, a cycloalkane structure and a cycloalkene structure are preferred. Is most preferred.

The number of carbon atoms constituting the alicyclic structure is not particularly limited, but is usually 4 to 30, preferably 5 to 20.
When the number is within the range of 5 to 15, more preferably, the mechanical properties, heat resistance and the like are excellent.

The proportion of the repeating unit having an alicyclic structure in the polymer having an alicyclic structure used in the present invention may be appropriately selected according to the purpose of use, but is usually at least 30% by weight, preferably at least 30% by weight. Is at least 50% by weight, more preferably at least 70% by weight. If the proportion of the repeating unit having an alicyclic structure is too small, the heat resistance tends to be poor.

The alicyclic structure preferably contains a repeating unit having a ring structure other than the norbornane structure. The proportion of the repeating unit having a ring structure other than the norbornane structure contained in the alicyclic structure is usually at least 10% by weight, preferably at least 30% by weight. This is because the larger the proportion of the repeating unit having a ring structure other than the norbornane structure, the better the impact resistance and light resistance.

The remainder other than the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer is appropriately selected according to the purpose of use.

Specific examples of such an alicyclic structure-containing polymer include, for example, a norbornene-based polymer, a monocyclic cycloolefin-based polymer, a cyclic conjugated diene-based polymer, a vinyl alicyclic hydrocarbon polymer, and These hydrogenated products are exemplified. Among these, norbornene-based polymers and hydrogenated products thereof, cyclic conjugated diene-based polymers and hydrogenated products thereof are preferable, and norbornene-based polymers and hydrogenated products thereof are more preferable.

There is no particular limitation on the norbornene-based polymer, and for example, polymers disclosed in JP-A-3-14882 and JP-A-3-122137 are used. Specific examples include ring-opened polymers of norbornene-based monomers and hydrogenated products thereof, addition polymers of norbornene-based monomers, and addition-type polymers of norbornene-based monomers and vinyl monomers copolymerizable therewith. . Of these, in order to achieve a high balance between heat resistance, moldability and mechanical strength, it is preferable to use a hydrogenated product of a ring-opening polymer of a norbornene-based monomer, an addition-type polymer of a norbornene-based monomer, and a norbornene-based monomer. An addition copolymer with a polymerizable vinyl monomer, more preferably a hydrogenated ring-opening polymer of a norbornene monomer.

As the norbornene-based monomer, for example,
For example, bicyclo [2.2.1] -hept-2-ene (conventional)
Name: norbornene), 5-methyl-bicyclo [2.2.
1] -Hept-2-ene, 5,5-dimethyl-bicyclo
[2.2.1] -Hept-2-ene, 5-ethyl-bishi
Black [2.2.1] -hept-2-ene, 5-butyl-
Bicyclo [2.2.1] -hept-2-ene, 5-hex
Sil-bicyclo [2.2.1] -hept-2-ene, 5
-Octyl-bicyclo [2.2.1] -hept-2-e
5-octadecyl-bicyclo [2.2.1] -heptane
To-2-ene, 5-ethylidene-bicyclo [2.2.
1] -Hept-2-ene, 5-methylidene-bicyclo
[2.2.1] -Hept-2-ene, 5-vinyl-bishi
Black [2.2.1] -hept-2-ene, 5-propeni
Rubicyclo [2.2.1] -hept-2-ene, 5-
Methoxy-carbonyl-bicyclo [2.2.1] -hep
To-2-ene, 5-cyano-bicyclo [2.2.1]-
Hept-2-ene, 5-methyl-5-methoxycarboni
Rubicyclo [2.2.1] -hept-2-ene, 5-
Methoxycarbonyl-bicyclo [2.2.1] -hept
-2-ene, 5-ethoxycarbonyl-bicyclo [2.
2.1] -Hept-2-ene, 5-methyl-5-ethoxy
Cycarbonyl-bicyclo [2.2.1] -hept-2-
Ene, bicyclo [2.2.1] -hept-5-enyl-
2-methylpropionate, bicyclo [2.2.1]-
Hept-5-enyl-2-methyloctanate, bicyclic
B [2.2.1] -Hept-2-ene-5,6-dical
Boric anhydride, 5-hydroxymethyl-bicyclo [2.
2.1] -Hept-2-ene, 5,6-di (hydroxy
Methyl) -bicyclo [2.2.1] -hept-2-e
5-hydroxy-i-propyl-bicyclo [2.
2.1] -Hept-2-ene, bicyclo [2.2.1]
-Hept-2-ene, 5,6-dicarboxy-bicyclo
[2.2.1] -Hept-2-ene, bicyclo [2.
2.1] -Hept-2-ene-5,6-dicarboxylic acid
Mido, 5-cyclopentyl-bicyclo [2.2.1]-
Hept-2-ene, 5-cyclohexyl-bicyclo
[2.2.1] -Hept-2-ene, 5-cyclohexe
Nyl-bicyclo [2.2.1] -hept-2-ene, 5
-Phenyl-bicyclo [2.2.1] -hept-2-e
, Tricyclo [4.3.0.1^2,5]-Deca-
3,7-diene (common name dicyclopentadiene), tri
Cyclo [4.3.0.1^2,5] -Dec-3-ene,
Tricyclo [4.4.0.1^2,5]-Undeca-
3,7-diene, tricyclo [4.4.0.
1^2,5] -Undeca-3,8-diene, tricyclo
[4.4.0.1^2,5] -Undec-3-ene, te
Toracyclo [7.4.0.1 ^10,13.
0^2,7] -Trideca-2,4,6-11-tetrae
(1,4-methano-1,4,4a, 9a-tetrahydric
Rofluorene), tetracyclo [8.4.0.
1^11,14. 0^3,8] -Tetradeca-3,5
7,12-11-tetraene (1,4-methano-1,
4,4a, 5,10,10a-Hexahydroanthrace
Tetracyclo [4.4.0.1)
^2,5. 1^7,10] -Dodeca-3-ene (simply tet
Lacyclododecene), 8-methyl-tetracycline
B [4.4.0.1^2,5. 1^7,10]-Dodeca-
3-ene, 8-ethyl-tetracyclo [4.4.0.1
^2,5. 1^7,10] -Dodeca-3-ene, 8-methyl
Lidene-tetracyclo [4.4.0.1^2,5. 1
^7,10] -Dodeca-3-ene, 8-ethylidene-tet
Lacyclo [4.4.0.1^2,5. 1^7,10] -Do
Dec-3-ene, 8-vinyl-tetracyclo [4.4.
0.1^2,5. 1^7,10] -Dodeca-3-ene, 8
-Propenyl-tetracyclo [4.4.0.1^2,5 .
1^7,10] -Dodeca-3-ene, 8-methoxycarbo
Nyl-tetracyclo [4.4.0.1^2,5. 1
^7,10] -Dodeca-3-ene, 8-methyl-8-metho
Xycarbonyl-tetracyclo [4.4.0.1
^2,5. 1^7,10] -Dodeca-3-ene, 8-hide
Roxymethyl-tetracyclo [4.4.0.
1^{2 , 5}. 1^7,10] -Dodeca-3-ene, 8-ca
Ruboxy-tetracyclo [4.4.0.1^2,5. 1
^7,10] -Dodeca-3-ene, 8-cyclopentyl-
Tetracyclo [4.4.0.1^2,5. 1^7,10]
-Dodeca-3-ene, 8-cyclohexyl-tetracycline
B [4.4.0.1^2,5. 1^7,10]-Dodeca-
3-ene, 8-cyclohexenyl-tetracyclo [4.
4.0.1.^{2, 5}. 1^7,10] -Dodeka-3-e
8-phenyl-tetracyclo [4.4.0.1
^2,5. 1^7,10] -Dodeca-3-ene, pentacy
Black [6.5.1.1^3,6. 0^2,7. 0
^9,13] -Pentadeca-3,10-diene, pentacyclo
Black [7.4.0.1^3,6. 1^{10,1 3}. 0
^2,7] -Pentadeca-4,11-diene and the like
Can be

The norbornene monomers can be used alone or in combination of two or more.

Examples of the vinyl monomer copolymerizable with the norbornene monomer include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-
Methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1
-Hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1
-Ethylene or α-olefin having 2 to 20 carbon atoms such as hexadecene, 1-octadecene, 1-eicosene;
Cyclobutene, cyclopentene, cyclohexene, 3,
4-dimethylcyclopentene, 3-methylcyclohexene, 2- (2-methylbutyl) -1-cyclohexene,
Cyclooctene, 3a, 5,6,7a-tetrahydro-
Cycloolefins such as 4,7-methano-1H-indene; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7
Non-conjugated dienes such as octadiene;

These vinyl monomers can be used alone or in combination of two or more.

The polymerization method and hydrogenation method of the norbornene monomer or the norbornene monomer and a vinyl monomer copolymerizable therewith are not particularly limited, and can be carried out according to known methods.

The ring-opening (co) polymer of a norbornene-based monomer is prepared by converting a norbornene-based monomer into a ruthenium, rhodium, palladium, osmium,
Iridium, a metal halide such as platinum, a nitrate or acetylacetone compound and a catalyst system comprising a reducing agent, or titanium, vanadium, zirconium, tungsten, a metal halide such as molybdenum or an acetylacetone compound, and an organic aluminum compound Using a catalyst system consisting of: in a solvent or without a solvent, usually at a polymerization temperature of −50 to 100 ° C., 0 to 50 kg / cm
It can be obtained by performing ring-opening (co) polymerization at a polymerization pressure of ² .

The hydrogenated norbornene-based polymer can be obtained by a conventional method in which a ring-opened (co) polymer is hydrogenated with hydrogen in the presence of a hydrogenation catalyst.

The catalyst system includes molecular oxygen, alcohol, ether, peroxide, carboxylic acid, acid anhydride, acid chloride,
By adding a third component such as an ester, ketone, nitrogen-containing compound, sulfur-containing compound, halogen-containing compound, molecular iodine, or other Lewis acid, the polymerization activity and the selectivity of ring-opening polymerization can be increased.

The norbornene-based monomer or the addition copolymer of the norbornene-based monomer and a vinyl-based monomer copolymerizable with the norbornene-based monomer can be prepared, for example, by mixing a monomer component with a titanium, zirconium, or vanadium compound in a solvent or without a solvent. In the presence of a catalyst system comprising an organoaluminum compound, the polymerization temperature is usually -50 to 100C,
It can be obtained by a method of copolymerizing at a polymerization pressure of 50 kg / cm ² .

The monocyclic cyclic olefin polymer includes:
For example, addition polymers of monocyclic cycloolefin monomers such as cyclohexene, cycloheptene and cyclooctene disclosed in JP-A-64-66216 can be exemplified.

Examples of the cyclic conjugated diene-based polymer include, for example, JP-A-6-13657 and JP-A-7-258.
No. 318 discloses a cyclic conjugated diene monomer such as cyclopentadiene and cyclohexadiene,
Examples thereof include a polymer obtained by 2- or 1,4-addition polymerization and a hydrogenated product thereof.

As the vinyl alicyclic hydrocarbon-based polymer,
For example, polymers of vinyl alicyclic hydrocarbon monomers such as vinyl cyclohexene and vinyl cyclohexane disclosed in JP-A-51-59989 and hydrogenated products thereof, JP-A-63-43910, JP-A-64-
Examples include hydrogenated products of the aromatic ring portion of a polymer of a vinyl aromatic monomer such as styrene and α-methylstyrene disclosed in Japanese Patent No. 1706.

The molecular weight of the alicyclic structure-containing polymer is determined by gel permeation chromatography of a cyclohexane solution (a toluene solution if the polymer resin does not dissolve) or polystyrene-equivalent weight average molecular weight (Mw). The number average molecular weight (Mn) is usually 5000 or more, preferably 5000 to 500000, more preferably 800.
0 to 200,000, more preferably 10,000 to 10
0000.

The glass transition temperature (Tg) of the polymer having an alicyclic structure is usually 70 ° C. or higher, preferably 90 ° C. or higher.
It is more preferably at least 100 ° C.

The melt flow rate of the alicyclic structure-containing polymer measured at 280 ° C. under a load of 2.16 kgf according to JIS-K6719 is usually 0.1 to 100 g / 1.
0 min. , Preferably 1 to 50 g / 10 min. It is.

These alicyclic structure-containing polymers can be used alone or in combination of two or more.

The alicyclic structure-containing polymer may be colored with an antioxidant, an ultraviolet absorber, a light stabilizer, a near infrared absorber, a dye or a pigment, if necessary, as long as the transparency is not impaired. Various compounding agents such as an agent, a lubricant, a softening agent, an antistatic agent, a fluorescent whitening agent, and a filler can also be compounded. Especially, it is preferable to mix a predetermined amount of an ultraviolet absorber (UVA). The ultraviolet absorber is not particularly limited,
It is preferably at least one selected from benzotriazole, benzoate, benzophenone, acrylic and metal complex systems.

Examples of the benzotriazole type ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) 2H-benzotriazole and 2- (3-t-butyl-2-hydroxy-5-methylphenyl)- 5-chloro-2H-benzotriazole, 2- (3,5-di-t
-Butyl-2-hydroxyphenyl) -5-chloro-2
H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole, 5-chloro-2- (3,5-di-t-butyl-2)
-Hydroxyphenyl) -2H-benzotriazole,
2- (3,5-di-t-amyl-2-hydroxyphenyl) -2H-benzotriazole and the like.

Examples of the benzoate-based ultraviolet absorber include 4-t-butylphenyl-2-hydroxybenzoate, phenyl-2-hydroxybenzoate,
2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, hexadecyl-
3,5-di-t-butyl-4-hydroxybenzoate, 2- (2H-benzotriazol-2-yl) -4
-Methyl-6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 2- (2-hydroxy-5
-T-octylphenyl) -2H-benzotriazole, 2- (2-hydroxy-4-octylphenyl)-
2H-benzotriazole and the like.

As the benzophenone-based ultraviolet absorber,
For example, 2,4-dihydroxybenzophenone, 2-
Hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid 3
Hydrate, 2-hydroxy-4-octyloxybenzophenone, 4-dodecaroxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2, 2'-dihydroxy-4,4'-dimethoxybenzophenone and the like.

Examples of the acrylic ultraviolet absorber include ethyl-2-cyano-3,3-diphenyl acrylate, 2'-ethylhexyl-2-cyano-3,3-diphenyl acrylate, and the like.

Examples of the metal complex type ultraviolet absorber include [2,2'-thiobis (4-t-octylphenolate)]-2-ethylhexylamine nickel.

These ultraviolet absorbers can be used alone or in combination of two or more.

The amount of the ultraviolet absorber is preferably 0.01 to 2 parts by weight per 100 parts by weight of the alicyclic structure-containing polymer.
0 parts by weight, more preferably 0.02 to 10 parts by weight, still more preferably 0.05 to 5 parts by weight.

The alicyclic structure-containing polymer may be blended with a near-infrared absorbing agent in a predetermined amount. in this case,
The near-infrared absorbing layer 28 described later may be provided or may not be provided.

Examples of the near-infrared absorbing agent include cyanine, pyrylium, squarylium, croconium, azurenium, phthalocyanine, dithiol metal complex, naphthoquinone, anthraquinone, indophenol, and azimuth. Can be SIR-103 and SIR-103 are commercially available near-infrared absorbers.
-114, SIR-128, SIR-130, SIR-
132, SIR-152, SIR-159, SIR-1
62 (manufactured by Mitsui Toatsu Dye), Kayasorb I
R-750, Kayasorb IRG-002, Ka
yasorb IRG-003, IR-820B, Kay
assorb IRG-022, Kayasorb IR
G-023, Kayasorb CY-2, Kayas
orbCY-4, Kayasorb CY-9 (above,
Nippon Kayaku).

These near infrared absorbers can be used alone or in combination of two or more.

The amount of the near-infrared absorbing agent is preferably 0.01 to 100 parts by weight of the alicyclic structure-containing polymer.
5 parts by weight.

The transparent substrate 22 preferably has a thickness of 0.1
A transparent resin film having a light transmittance of preferably about 85% or more, more preferably about 90% or more, having a surface smoothness of preferably about 10 to 10 mm, more preferably about 0.5 to 5 mm, is suitably used.

In order to obtain a transparent resin film, an alicyclic structure-containing polymer (including a compounding agent compounded as necessary)
Can be molded using a method such as a melt extrusion method, a solvent casting method, or an injection molding method. In addition, the transparent resin film is not limited to a film composed of a single base material, and may be a composite film subjected to various undercoating or surface treatment. In the compounding, a known method such as coating or sputtering can be used.

Ultraviolet absorbing layer 24 The ultraviolet transmittance of the ultraviolet absorbing layer 24 at a wavelength of 350 nm or less is preferably 5% or less, more preferably 3% or less, and further preferably 2% or less.

As a method of forming the ultraviolet absorbing layer 24, usually, the ultraviolet absorbing layer 24 is formed directly on the transparent substrate 22 or via another layer (a near infrared absorbing layer, an electromagnetic wave shielding layer, an antireflection layer, a hard coat layer, etc.) described later. The above-described method of applying a paint in which the ultraviolet absorber is mixed with a transparent resin is used.

As the transparent resin, for example, an ultraviolet curing resin, an electron beam curing resin, a thermosetting resin, a thermoplastic resin and the like can be mentioned.

The amount of the ultraviolet absorber is usually 0.1 to 15 parts by weight, preferably 0.1 to 15 parts by weight, based on 100 parts by weight of the transparent resin.
3 to 10 parts by weight, and the thickness of the ultraviolet absorbing layer 24 is usually about 1 to 300 μm.

Electromagnetic wave shielding function (electromagnetic wave shielding layer 2
6) The electromagnetic wave shielding function preferably has a wavelength of 30 to 1
The electromagnetic wave shielding performance of 30 MHz is 30 dB or more. In order to provide such an electromagnetic wave shielding function, a transparent conductive film is laminated on the transparent substrate 22, a conductive network is laminated, or a conductive network is buried inside the transparent substrate 22 to be integrated. In this embodiment, the electromagnetic shield layer 26 made of a transparent conductive film is laminated on the transparent substrate 22.

As a method of laminating the transparent conductive film, for example, a method of forming one or more transparent conductive layers made of a metal and / or a metal oxide by means such as vacuum deposition or sputtering, metal fine particles and / or Alternatively, a method of coating a resin in which conductive fine particles such as metal oxide fine particles are dispersed can be used. Its thickness is usually about 10 to 500 nm.

Examples of usable metals include gold,
Silver, platinum, palladium, copper, titanium, chromium, molybdenum, nickel, zirconium and the like can be mentioned. Among them, silver is preferable because a conductive layer having more excellent conductivity can be easily obtained. When this metal layer is provided as a conductive layer, it is preferable to form a multilayer film with a dielectric layer in order to prevent reflection of the metal layer. Examples of such a dielectric layer include layers made of various metal oxides, metal nitrides, metal sulfides, and the like. Examples of usable metal oxides include silicon oxide, titanium oxide, tantalum oxide, tin oxide, indium oxide, zirconium oxide, zinc oxide, and a composite oxide of indium oxide and tin oxide. These metals and metal oxides can be used alone or in combination of two or more.

Examples of the method of laminating the conductive net include a method of laminating a metal net or a resin woven cloth having a surface coated with a metal layer, or a method of laminating a transparent resin plate using a conductive ink or the like. A method of printing a lattice pattern on the surface, a method of providing a metal thin film such as copper or aluminum on the surface of a transparent resin plate, and then forming a lattice pattern by means such as etching can be cited.

Near-infrared absorption function (near-infrared absorption layer 28) The near-infrared absorption function is preferably a wavelength of 800 to 1
Near-infrared transmittance at 000 nm is 10% or less. In order to provide such a near-infrared absorbing function, as described above, a near-infrared absorbing agent may be mixed into the transparent substrate 22 itself.
A near-infrared absorbing layer 28 is laminated on the second. Its thickness is usually about 0.1 to 10 μm.

The near infrared absorbing layer 28 is made of, for example, a resin composition having near infrared absorbing performance. Examples of the resin composition having near-infrared absorption performance include a monomer having an unsaturated double bond, a copolymer obtained by copolymerizing a phosphorus atom-containing monomer, and a compound containing a copper atom. Resin composition containing copper compound and phosphorus compound; Resin composition containing copper compound and thiourea derivative; Resin composition containing tungsten compound; Monomer having unsaturated double bond And a resin composition containing a copolymer obtained by copolymerizing a specific phosphorus atom-containing monomer and a copper atom-containing compound; containing a specific (meth) acrylate resin, a phosphorus atom-containing compound, and a copper atom A resin composition containing a compound; a resin obtained by polymerizing a monomer having an unsaturated double bond; a resin composition containing a phosphorus atom-containing compound and copper hydroxide; and the like.

Antireflection function (antireflection layers 29a, 29
b) In order to provide an antireflection function, for example, a layer made of a low-refractive-index substance such as magnesium fluoride or silicon oxide is laminated, or a layer made of this low-refractive-index substance and titanium oxide, tantalum oxide, A method of laminating a multilayer antireflection layer in combination with a layer made of a high refractive index substance such as tin oxide, indium oxide, zirconium oxide, and zinc oxide can be adopted. In the present embodiment, two layers are used as the outermost layers. Anti-reflection layers 29a and 29b are laminated. Among them, a multilayer antireflection layer in which a layer made of indium oxide and tin oxide (ITO layer) and a layer made of silicon oxide are combined,
Alternatively, it is preferable to use a multilayer antireflection layer composed of at least two layers of a layer composed of silicon oxide and a layer composed of titanium oxide.

Anti-scratch function (hard coat layer, not shown)
(Abbreviated) In order to impart the damage prevention function, a hard coat layer (not shown) can be formed at least on the front surface side. Its thickness is usually about 1 to 100 μm.

As the polymer film constituting the hard coat layer, those generally used as a protective coating agent and a hard coating agent can be used, and examples thereof include a silicone hard coating agent and an organic hard coating agent. It is possible, but not limited to these.

Examples of the silicone hard coat agent include partial hydrates of silane compounds.
Examples of the organic hard coat agent include acrylic, melamine, alkyd, urethane and other ultraviolet curable and thermosetting hard coat agents, and resins such as alicyclic structure-containing polymers. Among them, excellent in transparency and heat resistance, and from the viewpoint of adhesion with the adjacent layer, preferably acrylic, silicon-based hard coat agent, more preferably a curable acrylic hard coat agent, more preferably A UV-curable acrylic hard coat agent, particularly preferably a polyfunctional acrylic UV-curable hard coat agent.

As the usable acrylic ultraviolet type hard coat agent, those containing a reactive monomer and / or a reactive oligomer and a photopolymerization initiator are used.

Examples of the reactive monomer include monofunctional acrylate monomers such as cyclohexyl acrylate, cyclohexyl methacrylate, glycidyl methacrylate, isobornyl methacrylate and other higher alkyl acrylates; ethylene glycol, diethylene glycol, tripropylene glycol, butylene glycol, Polyacrylic acrylate monomers in which two or more acrylates are bonded to polyols such as methylolpropane, trimethylolpropane, and pentaerythrol; and the like. Among them, a 1- to 6-functional acrylate is preferable, a 2- or 3-functional acrylate is more preferable, and an acrylate having an alicyclic structure is more preferable.

Examples of the reactive oligomer include a polyester acrylate having an acroyl group at a terminal, an epoxy acrylate or a polyurethane acrylate having an epoxy group in a molecular chain and an acryloyl group at a terminal,
Unsaturated polyester having a double bond in the molecular chain, 1,2
-Polybutazine and other oligomers having an epoxy group.

As the photopolymerization initiator, for example, 2,2
Acetophenones such as dimethoxy-2phenylacetophenone, 2,2-diethoxy-2phenylacetophenone and chlorinated acetophenone; benzophenones; benzoin ethers such as benzyl, methylorthobenzoylbenzoate and benzoylalkyl ether;
Azo compounds such as α'-azoisobutylnitrile, 2,2'-azobispropane and hydrazone; organic peroxides such as benzoyl peroxide and ditertiary butyl peroxide; diphenyl disulfide such as diphenyl sulfide and dibenzoyl sulfide And the like.

The acrylic ultraviolet-curable hard coat agent may be diluted with a solvent, and the type of the solvent can be appropriately selected according to the type of the hard coat agent.
Aromatic hydrocarbon solvents such as toluene and xylene; alicyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane and decalin can be used.

By dispersing the fine particles in such a polymer film, an antiglare function can be further provided.

The fine particles are for forming irregularities for reducing the gloss of the surface. As the fine particles, fine particles of an inorganic compound are preferably used. Fine particles having a particle size of 0.002 to 20 μm are usually used. The amount of the fine particles is preferably 1 to 15 parts by weight based on 100 parts by weight of the polymerizable compound to be added. If the amount is less than 1 part by weight, the glossiness increases, and a sufficient antiglare effect cannot be obtained, which is not preferable. On the other hand, when the amount exceeds 15 parts by weight, the amount of light diffusion increases, and the transparency decreases, which is not preferable.

The inorganic compound is not particularly restricted but includes, for example, silicon dioxide, aluminum oxide, magnesium oxide, tin oxide, silicon monoxide, zirconium oxide,
Inorganic oxides such as titanium oxide are preferred. Above all, silica fine particles whose main component is silicon dioxide are particularly preferable from the viewpoint of obtaining inexpensive particles having a narrow particle size distribution.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments at all, and can be implemented in various modes without departing from the gist of the present invention. Of course.

For example, when various functions such as an electromagnetic wave shielding function, a near-infrared absorption function, and an anti-reflection function are provided to the optical filter of the present invention, the order of lamination of the layers is limited to that of the above-described embodiment. Instead, various changes are possible.

In the above-described embodiment, the ultraviolet ray absorbing layer 24 and the near infrared ray absorbing layer 28 are provided separately.
By blending a near-infrared absorbing agent into the ultraviolet absorbing layer 24, or blending an ultraviolet absorbing agent into the near-infrared absorbing layer 28, a single layer may serve each function. May be blended with the antireflection layer 29b on the side facing.

Further, in the above-described embodiment, the optical filter of the present invention is arranged on the front surface of the PDP unit 6, and
Although described as an example of configuring the DP device, it can be suitably used as a front panel for various displays including, for example, a CRT (cathode ray tube).

[0082]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Production Examples, Examples, and Comparative Examples, but the scope of the present invention is not limited to these examples. In these examples, [parts] are based on weight unless otherwise specified. The methods for measuring various physical properties are as follows.

The hydrogenation rate of the main chain and the “hydrogenation rate (nuclear hydrogenation rate)” of the aromatic ring were measured by 1 H-NMR. "Glass transition temperature (Tg)" is based on JIS-K712.
1 based on a differential scanning calorimeter (DSC method).

"Molecular weight" refers to gel permeation chromatograph (GP) of a cyclohexane solution (a toluene solution if the resin does not dissolve) unless otherwise specified.
It is a value in terms of polyisoprene (in terms of polystyrene in the case of a toluene solution) measured by the method C).

The evaluation of “Transmissivity drop 1” was conducted by first measuring the light transmittance (T1, unit:%) of the optical filter at a wavelength of 365 nm before irradiating with ultraviolet light, and then measuring the ultraviolet light with an irradiation energy of 2000 mJ / cm ² . Was irradiated for 24 hours, the light transmittance (T2) at a wavelength of 365 nm was measured in the same manner as before the irradiation, and the difference (T2-T1) was used to evaluate the degree of decrease in the transmittance before and after the irradiation with ultraviolet rays. The evaluation criteria for the transmittance decrease are “低下” when the transmittance is 0% or more and 3% or less, “○” when the transmittance is greater than 3% and 4% or less, and “△” when the transmittance is greater than 4% and 5% or less. "
The case where it was larger than 5% was evaluated as "x".

The evaluation of “Transmissivity drop 2” was made by first evaluating the transmittance.
As in the case of the excess ratio reduction 1, the light transmittance (T
1) and then irradiation energy 2000 mJ /
cm² After irradiating with UV light for 240 hours,
Similarly, the light transmittance (T3) at a wavelength of 365 nm was measured.
And transparent by the formula (T3-T1) before and after UV irradiation.
The degree of rate reduction was evaluated. The evaluation criteria for the decrease in transparency are as follows:
When the value is 0% or more and 4% or less, "◎" indicates that the value is greater than 4%.
When the value is 5.5% or less, "○" indicates that the value is greater than 5.5%.
"△" when it is 7.5% or less, larger than 7.5%
The case was marked "x".

The evaluation of “decrease in transmittance 3” was made by first evaluating the transmittance.
As in the case of the excess ratio reduction 1, the light transmittance (T
1) and then irradiation energy 2000 mJ /
cm² After irradiation for 2400 hours,
Similarly, the light transmittance (T4) at a wavelength of 365 nm is
Measured and measured by the formula (T4-T1),
The degree of decrease in lightness was evaluated. Evaluation criteria for transparency reduction
Is “◎” when it is 0% or more and 5% or less, and is larger than 5%.
When the value is 7.5 or less, "○" indicates that the value is larger than 7.5%.
If the value is less than 10%, it is marked as “△”.
The case was marked "x".

"Visibility 1 and 2" were evaluated based on the rate of decrease in luminance and color temperature. The luminance reduction rate was determined by placing a light diffusing sheet of product number PCMSA manufactured by Tsujimoto Electric Manufacturing Co., Ltd. on one side of the filter, and a tube diameter of 2.4 mmφ manufactured by Harrison Electric Co., Ltd. at a distance of 10 cm from the light diffusing sheet. A cold cathode lamp is installed to irradiate light, and on the opposite side, on the normal line connecting the lamp and the filter, the distance from the filter is 1
The luminance and the color temperature were measured at a position of 0 cm using a luminance meter manufactured by Topcon; BM-7. The decrease rate of the luminance and the color temperature after irradiation for 100 hours and 1000 hours with respect to the luminance and the color temperature immediately after the start of the light irradiation was measured. Was rated as Δ, and the case exceeding 15% was rated as ×.

Example 1 Preparation of a polymer having an alicyclic structure 1 Under a nitrogen atmosphere, tricyclo [4.3.0.1 ^2,5 ]
Deca-3,7-diene (dicyclopentadiene; hereinafter,
DCP) and 85 parts of 8-ethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -dodeca-3
-En (hereinafter abbreviated as ETD) 15 parts (total 100 parts)
Was polymerized with a known metathesis ring-opening polymerization catalyst system, and then hydrogenated by a known method to obtain a hydrogenated DCP / ETD ring-opening polymer.

After completion of the hydrogenation reaction, the hydrogenation catalyst is removed from the reaction solution by a known method, and the hydrogenated polymer solution is added to a benzotriazole-based ultraviolet absorber (UVA), 2- (2'-hydroxy-). t-butyl-5'-methylphenyl) -5-chloro-benzotriazole (SEE
SORB 703: Shiraishi calcium) was added to 100 parts of the hydrogenated polymer, and the mixture was desolvated by a known method and then pelletized. As a result of analyzing the solution after the polymerization reaction by gas chromatography, it was found that all of the charged monomers had been converted to a polymer. This DCP
/ ETD ring-opened polymer hydrogenated product has a number average molecular weight of 270
00, hydrogenation rate is 99.8% or more, Tg is 104 ° C.,
The content of the repeating unit having a ring structure other than the norbornane ring was 85%.

Production of Transparent Substrate 22 The obtained pellets were melted at a temperature of 220 ° C. and a T-die width of 500 m using a T-die type film melt extruder having a resin melt kneader equipped with a screw of 65 mmφ.
Under the molding conditions of m, 100 μm × 1 with a thickness of 300 μm
A 00 mm substrate film (transparent substrate 22) was extruded.

Electromagnetic wave shield layer 26 and antireflection layer 2
Forming 9a One side of the obtained substrate film (the side facing the human body)
On top of this, a 200 nm thick ITO by sputtering
A film (electromagnetic wave shield layer 26) was formed, and an antireflection layer 29a having a thickness of 90 μm was further formed thereon. The anti-reflection layer 29a was formed by e-beam evaporation of a silicon oxide thin film.

The ultraviolet absorbing layer 24, the near infrared absorbing layer 28 and
And the formation of the antireflection layer 29b On the other surface (the side facing the panel) of the above-mentioned substrate film on which the electromagnetic wave shielding layer 26 and the antireflection layer 29a are not formed, a 10 μm thick ultraviolet absorbing layer 24 is formed. A near-infrared absorbing layer 28 having a thickness of 5 μm and an anti-reflection layer 29 b having a thickness of 90 μm are formed, and a plasma display panel (P
A front panel (optical filter) for DP) was obtained. The ultraviolet absorbing layer 24 was formed as follows.

100 parts of an acrylic resin hard coating agent (manufactured by Mitsubishi Rayon Co., Ltd .: Diabeam UR4315: an acrylic resin, an acrylic monomer and a photopolymerization initiator are blended as main components) 100 parts (coat layer forming component) Against
UV absorber (SEESORB7 manufactured by Shiraishi Calcium Co., Ltd.)
09 (benzotriazole type) was dissolved in 7.5 parts to prepare a coating agent containing an ultraviolet absorber.

This ultraviolet absorbent-containing coating agent is sprayed on the surface of the molded article, and applied so that the cured coating layer (ultraviolet absorbing layer) has a thickness of about 10 μm.
After drying at ℃ for 3 minutes, the coating layer was cured by irradiating 3000 mJ with an ultraviolet irradiation device to form an ultraviolet absorbing layer.

The near-infrared absorbing layer 28 was formed as follows. 100 parts of PMMA binder "Dianal BR-80" manufactured by Mitsubishi Rayon Co., Ltd., 4 parts of NIRKA's near-infrared absorbing agent "IRG-022 (diimonium)",
Nippon Shokubai's near-infrared absorbing agent "EX Color IR-
3 (phthalocyanine) ", and a coating solution diluted with a methyl ethyl ketone solvent to a solid content of 10% was prepared. This coating solution was coated on the electromagnetic wave shielding layer and dried to obtain a near-infrared absorbing layer having a thickness of 5 μm.

The transmittance reduction 1, 2 and 3 and the visibility 1 and 2 of the PDP front panel thus obtained were evaluated. Table 1 shows the results.

Example 2 A front panel for PDP was obtained in the same manner as in Example 1 except that no ultraviolet absorber was added to the alicyclic structure-containing polymer.
The transmittance reduction 1, 2, 3 and the visibility 1, 2 were evaluated. Table 1 shows the results.

Example 3 A front panel for PDP was obtained in the same manner as in Example 1 except that the ultraviolet absorbing layer 24 was not provided, and the transmittance was reduced.
And the visibility 1 and 2 were evaluated. Table 1 shows the results.

Example 4 The procedure of Example 1 was repeated, except that the alicyclic structure-containing polymer of Preparation Example 2 was used in place of the alicyclic structure-containing polymer of Preparation Example 2 (including an ultraviolet absorber). In the same manner as in the above, a front panel for PDP was obtained, and the reduction in transmittance 1, 2 and 3 and the visibility 1 and 2 were evaluated. Table 1 shows the results.

[0101]Production Example 2 of alicyclic structure-containing polymer 1m with stirring blade³Tetracyclod from the top of the polymerization vessel
A cyclohexane solution of decene (TCD) is placed in a polymerization vessel.
Supply concentration of TCD is 60kg / m³So that
Were continuously fed. In addition, from the top of the polymerization reactor,
VO (OC ₂H₅) Cl₂The cyclohexa
The vanadium concentration in the polymerization vessel is 0.9 mol
/ M³So that ethyl aluminum
Lido (Al (C₂H₅)_1.5Cl_1.5)of
When the concentration of aluminum in the polymerization
7.2 mol / m³In the polymerization vessel so that
Feeded continuously. Also, using a bubbling tube for the polymerization system
85m ethylene³/ Hour, nitrogen 45m³/Time
Between, 6m of hydrogen³/ Hour. Outside the polymerization vessel
Polymerization by circulating a heating medium through a jacket attached to
The copolymerization reaction was carried out while maintaining the system at 10 ° C. Above
Polymerization solution of copolymer formed by polymerization reaction
From the top, the polymerization liquid in the polymerization vessel is always 1m³To be
(Ie, so that the average residence time is 0.5 hours)
Extracted continuously. To the extracted polymerization solution, add
Hexane / isopropyl alcohol (1: 1) mixture
The polymerization reaction was stopped by addition. Then 1m of water³To
An aqueous solution containing 5 liters of concentrated hydrochloric acid and a 1: 1 ratio
And the mixture was brought into contact with vigorous stirring to transfer the catalyst residue to the aqueous phase.
After allowing the contact mixture to stand, the aqueous phase is separated and removed.
Further, washing with water was performed twice, and the polymerization liquid phase was purified and separated. Next
The polymer solution purified and separated is strongly stirred with 3 times the amount of acetone.
After contacting underneath to precipitate the copolymer, the solid part (copolymer
Was collected by filtration and washed thoroughly with acetone.
In addition, extract unreacted monomers present in the polymer
In order to reduce the solid content to 40 kg / m³So that
After pouring into acetone, extract at 60 ° C for 2 hours
The operation was performed. After extraction, the solid part is collected by filtration
And under nitrogen flow at 130 ° C and 350 mmHg for 12 hours
Dried. The obtained ethylene / TCD copolymer is 13
0 ° C., intrinsic viscosity [η] in decalin solution is 0.42 dl
/ G, Tg is 140 ° C, TCD content is 31 mol%.
Was. A repeating unit consisting of a ring structure other than a norbornane ring
Was 0%.

Examples 5 to 7 The same procedures as in Example 1 were carried out except that the amount of the ultraviolet absorber added to the alicyclic structure-containing polymer was changed to 0.2 part, 0.1 part and 0.05 part, respectively. In the same manner, a front panel for PDP was obtained, and the reduction in transmittance 1, 2 and 3 and the visibility 1 and 2 were evaluated.
Table 1 shows the results.

Comparative Example 1 A front panel for PDP was obtained in the same manner as in Example 1 except that no ultraviolet absorber was added to the alicyclic structure-containing polymer and the ultraviolet absorbing layer 24 was not provided. Rate drop 1, 2,
3 and visibility 1 and 2 were evaluated. Table 1 shows the results.

[0104]

[Table 1]

As shown in Table 1, when the ultraviolet absorber was not added to the substrate and the ultraviolet absorbing layer was not separately provided as in Comparative Example 1, the transmittance before and after the ultraviolet irradiation decreased. It was confirmed that, as a result, the visibility was reduced. The same tendency was observed when the amount of the ultraviolet absorber added was too small as in Comparative Example 2. On the other hand, in Examples 1 to 7, it was confirmed that the transmittance did not decrease much before and after the irradiation of the ultraviolet rays, and that the visibility was good.

[0106]

As described above, according to the present invention, even when used for a long time, there is little coloring of the substrate due to ultraviolet rays, and as a result, there is little possibility of lowering the overall visibility, and A display device using this can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an optical filter according to the present invention.

[Explanation of symbols]

 2 Optical filter 22 Transparent substrate 24 Ultraviolet absorbing layer 26 Electromagnetic wave shielding layer 28 Near infrared absorbing layer 29a, 29b Antireflection layer 6 PDP unit 62 Image display surface

 ────────────────────────────────────────────────── ─── Continuing on the front page F term (reference) 2H048 AA05 AA07 AA15 AA16 AA18 AA28 4F100 AA20 AA28 AA33 AH08A AH08B AH08H AK02A AK25 AK25A AK25B AK25H AT00A BA02 BA03 BA04 BA05 BA07 CA07E07D09 J07 E07B09 J08 JD14 JD14B JN01A JN06 JN08A JN28 JN30 YY00A

Claims (6)

[Claims] 1. An optical filter having at least a transparent substrate made of a polymer having an alicyclic structure, wherein the light transmittance at a wavelength of 365 nm before irradiation with ultraviolet rays is 6
An optical filter having a transmittance of 0% or more and a decrease in light transmittance at a wavelength of 365 nm of 5% or less after irradiation with ultraviolet rays of 2000 mJ / cm ² for 24 hours. 2. The optical filter according to claim 1, further comprising an ultraviolet absorbing layer containing an ultraviolet absorbing agent. 3. The alicyclic structure-containing polymer constituting the transparent substrate is mixed with 0.01 to 20 parts by weight of an ultraviolet absorber based on 100 parts by weight of the alicyclic structure-containing polymer. The optical filter according to claim 1, wherein the optical filter is provided. 4. The ultraviolet absorber is at least one selected from a benzotriazole ultraviolet absorber, a benzoate ultraviolet absorber, a benzophenone ultraviolet absorber, an acrylic ultraviolet absorber, and a metal complex ultraviolet absorber. 4. The optical filter according to claim 2, wherein: 5. A display device, wherein the optical filter according to claim 1 is disposed on a front surface of a display element. 6. A plasma display device, wherein the optical filter according to claim 1 is arranged on a front surface of a plasma display panel.