JP2000162431A - Filter for plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter for a plasma display panel which shields near- infrared radiatiated from a plasma display panel without damaging a display performance. SOLUTION: This filter for a plasma display panel has a layer containing a squarilium compound represented by general formula I on a transparent board. In formula I, R1, R2 and R3 are each independently an alkyl group capable of having a hydrogen atom and substituent group, a cycloalkyl group capable of having a substituent group, and an aryl or heteroaryl group capable of having a substituent group, while a 5-or 6-membered ring or a part thereof can be formed by connecting R1 and R2, or R2 and R3 with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a filter for a plasma display panel. More particularly, the present invention relates to a filter for a plasma display panel that can effectively shield near infrared rays emitted from the plasma display panel.

[0002]

2. Description of the Related Art In recent years, plasma display panels have been used as display panels for various types of electronic devices such as large wall-mounted televisions, and their demand has been increasing, and it is expected that the number will increase further in the future. Thus, plasma displays emit near-infrared light. The development of technology to detect and read information data using near-infrared light is also progressing, and devices such as cordless horns or remote control devices, which are familiar to us, are being actively developed in various automatic control technology fields such as driving robots. The technology is becoming more and more accurate. If high-precision work using near-infrared light is to be controlled, the malfunction of information detection devices, reading devices, and other various instruments due to near-infrared light that enters from other devices and other places will accompany it. Troubles have increased, and in the medical and other fields,
Malfunctions of the therapy device can also be life-threatening for the patient.

Therefore, unless the emission of near-infrared light is prevented, it is not possible to install a plasma display panel in the vicinity of a device using near-infrared light, and the use of the plasma display panel is greatly increased. Will be narrowed down. Therefore, Japanese Patent Application Laid-Open No. 9-230134 proposes a filter using an infrared absorbing dye to cut off near infrared rays emitted from a plasma display panel. However, not all infrared absorbing dyes can be used for plasma display filters. It is necessary to be a dye that cuts near infrared rays emitted from the plasma display and has no fear of hindering the sharpness of the display.

[0004]

SUMMARY OF THE INVENTION The present invention cuts near infrared rays emitted from a plasma display,
An object of the present invention is to provide a plasma display filter that does not impair the function of the display. It is an object of the present invention to provide a filter which is excellent in light resistance and capable of blocking light rays having a wide range of wavelengths in the near infrared region.

[0005]

Means for Solving the Problems The present inventors have conducted various studies and found that the above object can be achieved by using a specific squarylium compound. That is, the gist of the present invention resides in a filter for a plasma display panel, comprising a layer containing a squarylium-based compound represented by the following general formula (I) on a transparent substrate.

[0006]

Embedded image

(Wherein R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, Represents an aryl group or a heteroaryl group which may have a substituent, and R ¹ and R ² or R ² and R ³ may be linked to each other to form a 5- or 6-membered ring or a part of a ring; good.)

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The squarylium-based compound used in the present invention is represented by the general formula (I). In the general formula (I), R ¹ ,
When R ² and R ³ are an alkyl group which may have a substituent, specifically, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group , Decyl, undecyl, dodecyl, tridecyl, pentadecyl, etc.
Straight-chain or branched-chain alkyl groups; alkyl groups substituted with halogen atoms such as chloromethyl group, dibromoethyl group, trifluoromethyl group; methoxyethyl group, ethoxyethyl group, propoxyethyl group, butoxyethyl group,
An ether group-containing alkyl group such as a methoxyethoxyethyl group or an ethoxyethoxyethyl group; a phenyl group substituted with an alkyl group such as a phenyl group, a 4-ethylphenyl group or a 4-butylphenyl group as a substituent, a 4-chlorophenyl group, 4-bromophenyl group, phenyl group substituted by halogen atom such as 4-fluorophenyl group, 4-methoxyphenyl group, 4-ethoxyphenyl group, 4-butoxyphenyl group, 4-hexyloxyphenyl group, 4-octyl A phenyl group, a naphthyl group, a furyl group, a thienyl group substituted with an alkoxy group such as an oxyphenyl group; an aromatic ring which may contain a nitrogen atom or a sulfur atom such as a pyridyl group; a phenyloxy group; Phenyl substituted with an alkyl group such as ethylphenyloxy group and 4-butylphenyloxy group A phenyloxy group substituted with a halogen atom such as an xy group, a 4-chlorophenyloxy group, a 4-bromophenyloxy group, or a 4-fluorophenyloxy group; a 4-methoxyphenyloxy group; a 4-ethoxyphenyloxy group; Butoxyphenyloxy group, 4-
Hexyloxyphenyloxy group, aryloxy group such as phenyloxy group substituted by alkoxy group such as 4-octyloxyphenyloxy group, cyclohexyl group,
A cycloalkyl group which may be substituted with an alkyl group such as a 4-ethylcyclohexyl group, a 4-n-butylcyclohexyl group, a 4-tert-butylcyclohexyl group,
Acetyloxy group, butyryloxy group, hexanoyloxy group, methyl group which may have an alkanoyloxy group such as nonanoyloxy group, ethyl group, propyl group,
Examples include an alkyl group such as a butyl group.

The cycloalkyl group in which R ¹ , R ² and R ³ may have a substituent includes a cyclohexyl group,
A cyclohexyl group substituted with an alkyl group such as an -ethylcyclohexyl group, a 4-n-butylcyclohexyl group, a 4-tert-butylcyclohexyl group, and a cyclopentyl group. When R ¹ , R ² , and R ³ are an aryl group or a heteroaryl group which may have a substituent, for example, a phenyl group; a 4-ethylphenyl group,
A phenyl group substituted with an alkyl group such as -butylphenyl group, a 4-chlorophenyl group, a 4-bromophenyl group,
A phenyl group substituted with a halogen atom such as a 4-fluorophenyl group; an alkoxy group such as a 4-methoxyphenyl group, a 4-ethoxyphenyl group, a 4-butoxyphenyl group, a 4-hexyloxyphenyl group, a 4-octyloxyphenyl group; A phenyl group substituted with a group; a naphthyl group; a heteroaryl group which may contain a nitrogen atom, a sulfur atom, or the like, such as a furyl group, a thienyl group, a pyridyl group, or a group substituted with a substituent as described above. And the like.

The squarylium-based compound of the formula (I) is preferably a compound wherein R ¹ is a hydrogen atom and R ² and R ³ are alkyl groups or R ² and R ³ are linked and substituted cycloalkylidene groups, R ¹ is a hydrogen atom, R ² , R ³
There aryl group as a substituent, an aryloxy group, an alkyl group which may have a alkanoyloxy group, the compound is a group selected from aryl group or a furyl group or R ¹ and R ² are linked 2 carbon atoms An alkylene group of 4,
A compound in which R ³ is a phenyl group. The squarylium-based compound of the general formula (I) is described in, for example, JP-A-10-366.
As described in Japanese Patent Publication No. 95, the following general formula (II)

[0011]

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(Wherein R ¹ , R ² , and R ³ have the same significance as described above), and 1 mol of squaric acid is added to 2 mol of the 2,3-dihydroperimidine compound represented by the following formula: It is synthesized by dehydration-condensation in a solvent such as butyl alcohol, n-amyl alcohol, n-hexyl alcohol or the like in the presence of an acid catalyst such as p-toluenesulfonic acid while heating to about 100 to 150 ° C. in the presence of an acid catalyst. be able to. The filter of the present invention is easily manufactured by applying a coating solution containing a squarylium-based compound of the general formula (I) on a transparent substrate formed into a film or a sheet.

The material of the transparent substrate constituting the filter for the plasma display panel of the present invention is not particularly limited as long as it is substantially transparent and does not have large absorption and scattering. Specific examples include glass, polyolefin resin, amorphous polyolefin resin, polyester resin, polycarbonate resin, poly (meth) acrylate resin, polystyrene, polyvinyl chloride, polyvinyl acetate, and polyarylate resin. And polyether sulfone resins. Among these, amorphous polyolefin resin, polyester resin, polycarbonate resin, poly (meth) acrylate resin, polyarylate resin, polyether sulfone resin and the like are particularly preferable.

The resins described above are generally known additives, for example, phenol-based, phosphorus-based antioxidants, halogen-based, phosphoric acid-based flame retardants, heat aging inhibitors, ultraviolet absorbers, lubricants. And an antistatic agent and the like. The resin is formed into a film or sheet (plate) using a known method such as injection molding, T-die molding, calender molding, or compression molding, or a method of melting and casting in an organic solvent. The thickness is preferably in the range of 10 μm to 5 mm depending on the purpose. The substrate constituting such a transparent substrate may be unstretched or stretched.
Further, it may be laminated with another base material. Further, the transparent substrate is subjected to a surface treatment by a conventionally known method such as a corona discharge treatment, a flame treatment, a plasma treatment, a glow discharge treatment, a surface roughening treatment, a chemical treatment, or a coating such as an anchor coating agent or a primer. Is also good.

The coating liquid applied on the substrate may be prepared by dissolving a squarylium compound of the general formula (I) in a solvent together with a binder, or a squarylium compound atomized to a particle size of 0.1 to 3 μm. It is prepared by a method of dispersing in a solvent together with a binder using a dispersant according to the above. The solid content of the squarylium-based compound, binder, dispersant and the like dissolved or dispersed in the coating liquid is 0.5 to 50% by weight, and the proportion of the squarylium-based compound in the binder and dispersant is 0%. .05-5
0% by weight, preferably 0.1 to 20% by weight.

[0016] The dispersant optionally used includes:
Examples thereof include polyvinyl butyral resin, phenoxy resin, rosin-modified phenol resin, petroleum resin, cured rosin, rosin ester, maleated rosin, and polyurethane resin. The amount used is 0.5 to 150 times by weight, preferably 10 to 100 times by weight, based on the squarylium-based compound. As the binder used, polymethyl methacrylate resin, polyethyl acrylate resin,
Examples thereof include a polycarbonate resin, an ethylene-vinyl alcohol copolymer resin, and a polyester resin. The used amount is 10 to 200 times by weight, preferably 50 to 150 times by weight based on the squarylium-based compound.

The solvent is not particularly limited. For example, aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and cyclohexanone; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol Glycol solvents such as glycol diethyl ether, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate; and ester solvents such as ethylethoxypropionate are used. Known coating methods such as a dipping method, a flow coating method, a spray method, a bar coating method, a gravure coating method, a roll coating method, a blade coating method, and an air knife coating method are used as a coating method of a coating liquid containing a squarylium-based compound. Adopted. The coating film thickness is 0.1 mm after drying.
It is coated so as to have a thickness of 1 to 30 μm, preferably 0.5 to 10 μm.

The squarylium-based compound obtained by directly dissolving or dispersing the squarylium-based compound represented by the general formula (I) in various resins or other resins constituting the transparent substrate is provided. The resin containing the compound can be manufactured by molding and forming into a film using a molding technique such as injection molding, T-die molding, calender molding or compression molding, and then bonding it to another transparent substrate as necessary.

Further, instead of the method of coating the coating solution, the squarylium-based compound represented by the general formula (I) is dyed on a resin sheet or film constituting a transparent substrate or another resin sheet (plate) or film. It can also be manufactured by adhering it and attaching it to another transparent substrate if necessary. Further, a transparent resin layer (UV cut film) containing an ultraviolet (UV) absorber may be laminated on the outside in order to increase the light resistance of the filter.

As a malfunction prevention filter for a plasma display, it is installed in front of a display for the purpose of cutting off near-infrared light emitted from the display. Therefore, if the transmittance of visible light is low, the sharpness of an image may be reduced. Therefore, the higher the visible light transmittance of the filter, the better, and it is required to be at least 40% or more, preferably 50% or more. In addition, the cut region of near-infrared light is a wavelength that is particularly problematic for remote control and transmission-based optical communication.
It is designed so that the average light transmittance in that region is 10% or less. If necessary, two or more squarylium compounds represented by the above general formula (I) may be used in combination, for example, a nitroso compound and a metal complex salt thereof, a cyanine compound, a dithiol nickel complex compound. , Phthalocyanine compounds, triallylmethane compounds, immonium compounds, diimmonium compounds, naphthoquinone compounds, anthraquinone compounds, amino compounds, aminium salt compounds, or carbon black, indium tin oxide, antimony tin oxide and the like It can also be used in combination with a near infrared absorbing dye.

The filter for a plasma display panel of the present invention may be provided with an electromagnetic wave cut layer, an antireflection layer for preventing reflection of external light such as a fluorescent lamp on the surface, and a glare prevention (non-glare) layer. it can. For the electromagnetic wave cut layer, a vapor deposition or sputtering method of a metal oxide or the like can be used. Usually, indium tin oxide (IT
O) is generally used, but a dielectric layer and a metal layer are alternately laminated on a base material by sputtering or the like to obtain a thickness of 1000 nm.
The above light can also be cut. The dielectric layer is a transparent metal oxide such as indium oxide or zinc oxide, and the metal layer is generally silver or a silver-palladium alloy. Usually, starting with the dielectric layer, three layers, five layers,
About 7 or 11 layers are laminated. As the substrate, a plasma display panel filter may be used as it is, or may be attached to the resin film or glass after being deposited or sputtered on the filter.

The antireflection layer is used to reduce the reflection on the surface and improve the transmittance of the filter by filtering inorganic materials such as metal oxides, fluorides, silicides, borides, carbides, nitrides and sulfides. A method of laminating in a single layer or a multilayer by a vacuum evaporation method, a sputtering method, an ion plating method, an ion beam assist method, etc., a method of laminating a resin having a different refractive index such as an acrylic resin or a fluororesin in a single layer or a multilayer. Etc. Further, a film that has been subjected to an antireflection treatment can be attached on the filter.

Further, an anti-glare (non-glare) layer may be provided. For the non-glare layer, for the purpose of widening the viewing angle of the filter, a method of coating fine particles of silica, melamine, acrylic or the like with an ink and coating the surface of the filter to scatter transmitted light can be used. The ink can be cured by heat or light. In addition, a non-glare-treated film can be attached to the filter. If necessary, a hard coat layer may be provided. Furthermore,
The filter for a plasma display panel of the present invention,
It can be used alone or as a laminate bonded to a transparent glass or another transparent resin plate.

[0024]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Example 1 Polyethylene terephthalate film (Diafoil Hoechst PET film “T100E”, thickness 10)
0 μm), in the general formula (I), R ¹ = H, R ² = R ³ =
0.033 g of a squarylium-based compound which is C ₂ H ₅ ,
A coating solution composed of a solution (solid content: 9% by weight) in which 2 g of polyvinyl butyral resin and 3 g of polymethyl methacrylate resin were dissolved and dispersed in toluene was applied using a bar coater # 20 to obtain a filter for a plasma display panel. The coating thickness after drying was 5 μm. The light transmittance of this filter was measured with a Hitachi spectrophotometer (U-3500). The visible light transmittance (Tv) is 97.3% (JIS
Calculated according to -R-3106. ), The transmittance at 810 nm was 2.0%.

Examples 2 to 12 The squarylium compounds shown in Table 1 were used.
Processing was performed in the same manner as in Example 1 to form a plasma display panel filter, which was evaluated.

[0026]

[Table 1]

Example 13 An ITO thin film was laminated on one surface of the filter prepared in Example 1 using an indium oxide-tin oxide sintered body using argon gas and oxygen gas. Further, a surface of the 3 mm-thick PMMA plate (Acrylic Filter MR-NG manufactured by Mitsubishi Rayon Co.) having an antiglare layer on one side, on which the non-glare layer is not formed, and the ITO surface of the above filter are bonded together to prevent an electromagnetic wave cut layer and glare prevention. A filter for a plasma display panel having a layer was prepared.

[0028]

The filter for a plasma display panel of the present invention having a layer containing a squarylium-based compound represented by the general formula (I) is excellent in near-infrared shielding performance, visible light transmission performance, light resistance, and plasma display. The radiated near infrared rays can be efficiently cut, and adverse effects that may cause malfunctions of devices using the near infrared rays can be prevented.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H048 CA04 CA05 CA09 CA12 CA19 CA23 CA27 CA29 4J002 AF02X BA01X BB22W BG05W BG06W CB00X CC08X CF00W CG00W CK02X EA057 ED027 EE037 EH017 EU136 FD206 FD207 AGO00 GG00A GG07A

Claims (7)

[Claims] 1. A filter for a plasma display panel, comprising a layer containing a squarylium-based compound represented by the following general formula (I) on a transparent substrate. Embedded image (Wherein, R ¹ , R ² , and R ³ each independently represent a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, represents which may have an aryl group or a heteroaryl group, R ¹
And R ² or R ² and R ³ may be linked together to form a 5- or 6-membered ring or a part of a ring. ) 2. The squarylium-based compound according to the formula (I), wherein R ¹ is a hydrogen atom and R ² and R ³ are alkyl groups, or R ² and R ³ are linked to each other to form a substituted cycloalkylidene group. 2. The filter for a plasma display panel according to claim 1, wherein: 3. The squarylium-based compound according to formula (I), wherein R ¹ is a hydrogen atom, and R ² and R ³ each have an aryl group, an aryloxy group, or an alkanoyloxy group as a substituent. 2. The filter for a plasma display panel according to claim 1, wherein the filter is a group selected from good alkyl groups, aryl groups and furyl groups. 4. The squarylium-based compound according to the general formula (I), wherein R ¹ and R ² are linked to each other to form an alkylene group having 2 to 4 carbon atoms, and R ³ is a phenyl group. Item 7. A filter for a plasma display panel according to Item 1. 5. The filter for a plasma display panel according to claim 1, further comprising an electromagnetic wave cut layer. 6. The plasma display panel filter according to claim 1, further comprising an anti-reflection layer. 7. The filter for a plasma display panel according to claim 1, further comprising an anti-glare layer.