JPH1073721A - Optical filter for display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical filter for a display having excellent resistance against environment and cutting property for near IR ray emitted by a plasma display. SOLUTION: This filter for a display consists of a transparent base body (A) 20 and a light-controlling film (B) 10 laminated to one principal plane of the body 20. The film (B) 10 is produced by successively laminating a high refractive index transparent thin film layer (D) and a metal thin layer (E) as (D)/(E) repeating unit, repeating to deposit the units four or more times on one principal plane of a transparent polymer film (C), and further forming a high refractive index transparent thin film layer (D) and a transparent resin layer (F) thereon. Before the transparent resin layer is formed, the surface of the laminated film is treated with at least one kind of compd. selected from triazine amine compds. mercapto benzoimidazole compds., thiodipropionate compds., benzoimidazole compds., benzotriazole compds. and thiocarbamates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical filter for a display, and more particularly to an optical filter for a display. The present invention relates to an optical filter having excellent environmental resistance.

[0002]

2. Description of the Related Art Optoelectronics-related components and equipment have been remarkably advanced and spread as society has become highly information-oriented. Among them, displays have become extremely popular for televisions, personal computers, etc., and their thickness and size have been reduced.

[0003] In recent years, plasma displays have attracted attention for applications such as large-sized thin TVs and thin displays, and have already begun to appear on the market. However, a plasma display generates a strong leakage electromagnetic field due to its structural principle, and the effects of the leakage electromagnetic field on the human body and other devices in recent years have been investigated.
It is necessary to clear safety standards such as CC. Furthermore, in the plasma display, there is a problem that near-infrared light emitted from excited atoms in the plasma acts on peripheral electronic devices such as a cordless phone to cause a malfunction. 820 nm, which is used in remote control and transmission optical communication, is a particularly problematic wavelength.
And 880 nm and 980 nm. Therefore, it is necessary to cut light in the near-infrared wavelength range of 820 to 1000 nm.

On the other hand, if the transmittance of visible light is low, the sharpness of the image is reduced. Therefore, the visible light transmittance of the filter is preferably as high as possible, at least 40% or more, preferably 50%.
It is necessary.

The antistatic ability can be solved by directly forming a conductive film on the display surface or by attaching a member having the conductive film to the display surface and grounding the conductive film. In this case, the conductive film has a sheet resistance of 10 ^8.
What is necessary is just about Ω / □ or less. However, the transparency and resolution of the display screen must not be impaired.

On the other hand, in order to shield a leakage electromagnetic field (electromagnetic wave), it is necessary to cover the display surface with a conductive material having higher conductivity. Generally, a grounded metal mesh or a mesh of a synthetic resin or metal fiber coated with a metal is used.However, these methods may cause a portion that does not transmit light emitted from the display, generate moire, and increase costs due to poor yield. It becomes a problem.

Therefore, ITO (Indium Tin O)
xide) is used for the electromagnetic wave shielding layer. In that case, the conductivity usually required is a sheet resistance of 10 ⁵ Ω / □ or less, preferably 10 ³ Ω / □.
It is as follows. As the transparent conductive film, gold, silver, copper, platinum,
Metal thin film such as palladium, indium oxide, second oxide
There is a multilayer thin film in which an oxide semiconductor thin film such as tin or zinc oxide or a metal thin film and a high refractive index transparent thin film are laminated. Among them, a metal thin film can have conductivity, but cannot have a high visible light transmittance due to reflection and absorption of metal over a wide wavelength range. Further, the oxide semiconductor thin film is superior in transparency to the metal thin film, but inferior in conductivity, and has no near-infrared reflectivity. In contrast, a multilayer thin film composed of a metal thin film and a high-refractive-index transparent thin film is formed by the conductivity and optical properties of a metal such as silver and by preventing the high-refractive-index transparent thin film from being reflected by the metal in a certain wavelength region. It has favorable characteristics in all of electrical conductivity, near-infrared cut ability, and visible light transmittance.

That is, by alternately stacking a metal layer mainly composed of silver and a transparent high refractive index layer, for example, indium oxide, titanium oxide, zinc oxide and tin oxide,
They have found that a film having both transparency and the above-mentioned light control properties can be obtained. However, the silver layer has a disadvantage that it is unstable in a humid environment. According to our study, an optical filter in which a silver layer and a high refractive index layer are alternately stacked is actually used in an environment at 60 ° C. and a relative humidity of 90%. , It was found that holding for about 500 hours significantly impaired performance such as light transmittance.

[0009]

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, an object of the present invention is to generate a plasma display,
An object of the present invention is to provide a filter for a display that has excellent near-infrared ray blocking properties that block near-infrared rays that may cause erroneous operation of peripheral electronic devices, has anti-Newton ring properties, and is excellent in environmental resistance. That is, a metal layer mainly composed of silver and a transparent high-refractive index layer, for example, indium oxide, titanium oxide, zinc oxide, and tin oxide are alternately stacked,
In an optical filter using a film having both transparency and the above-mentioned dimming property, the surface on which a multilayer laminated film of the above-mentioned thin film is laminated is formed by triazineamine-based compound, mercaptobenzimidazole-based compound, thiodipropion. After treatment with at least one compound selected from the group consisting of an acid ester compound, a benzimidazole compound, a benzotriazole compound and a thiocarbamate, the environmental resistance is improved by forming a transparent resin layer. And reached the present invention.

[0010]

That is, the present invention provides a display filter in which at least one light control film (B) is bonded to one main surface of a transparent substrate (A). (B) is that at least one high refractive index transparent thin film layer (D) and a metal thin film layer (E) are sequentially formed on one main surface of the transparent polymer film (C) by (D) /
(E) is repeated four or more times as a repeating unit, and at least a high-refractive-index transparent thin film layer (D) is further laminated thereon, and a transparent resin layer (F) is further laminated thereon.
Having a visible light transmittance of 50% or more,
A film having a light transmittance of 10% or less for light having a wavelength of 820 nm to 1000 nm, wherein the surface of the laminated film is formed before forming the transparent resin layer (F).
Triazineamine compound, mercaptobenzimidazole compound, thiodipropionate compound,
An optical filter for a display treated with at least one compound selected from the group consisting of a benzimidazole compound, a benzotriazole compound and a thiocarbamate; The optical filter for a display described above, wherein the metal thin film layer (E) is silver or an alloy mainly containing silver, or the optical filter for a display described above. An optical filter for display having a structure in which an anti-Newton ring film is further attached to at least one main surface of the above, or an anti-Newton layer is formed, and the optical filter for display according to any one of-, which can be suitably used for a plasma display. Filter.

[0011]

DETAILED DESCRIPTION OF THE INVENTION As shown in FIG. 1 and FIG. 2, the present invention provides a light control film 10 on one main surface of a transparent substrate 20 by using an adhesive layer or an adhesive layer 70. Is a display filter on which the high-refractive-index transparent thin film layer 50 and the metal thin film layer 40 are repeatedly laminated on one main surface of the transparent polymer film 30 to form a transparent resin layer 60. Before formation, the surface of the laminated film is treated 90 with a specific compound.

As the transparent substrate (A) in the present invention,
An inorganic compound molded product such as glass and quartz and a transparent organic polymer molded product can be used, but the polymer molded product is light and hard to be broken, so that it can be more suitably used. The polymer molded product only needs to be transparent in the visible wavelength region, and specific examples thereof include an acrylic resin such as polymethyl methacrylate (PMMA), a polycarbonate resin, and a transparent AB.
S resins and the like can be used, but are not limited to these resins. In particular, PMMA can be suitably used because of its high transparency in a wide wavelength region and high mechanical strength. The thickness of the plastic plate is not particularly limited as long as sufficient mechanical strength and rigidity for maintaining flatness without sagging are obtained, and are not particularly limited, but are usually about 1 mm to 10 mm.

Light control film (B) in the present invention
Is a general term for a film that controls transmission and reflection of light.For example, in the present invention, visible light is easily transmitted,
A film that reflects infrared light. The light control film in the present invention is obtained by forming a thin multilayer film on at least one principal surface of the essentially transparent polymer film (C). The transparent polymer film (C) as a base material of the light control film is made of polyethylene terephthalate, polyether sulfone, polystyrene, polyethylene naphthalate, polyarylate, polyether ether ketone, polycarbonate, polypropylene, polyimide, polymethyl methacrylate, or the like. However, polyethylene terephthalate is preferably used because it has appropriate heat resistance. Since the base material is a film, the high-refractive-index transparent thin film layer and the metal thin film layer can be formed continuously by a roll-to-roll method. Is a film,
By sticking the light control film to the glass of the display, it is possible to prevent scattering when the glass is broken. In this case, a film having a thickness of usually 10 to 250 μm is used. If the thickness of the film is too small, the mechanical strength of the base material is insufficient. If the thickness is too large, the flexibility is insufficient, so that the film is not suitable for being wound on a roll and used.

The transparent polymer film as a base material is formed on the surface by subjecting the surface thereof to an etching treatment such as a glow discharge treatment, a corona treatment, a flame treatment, an ultraviolet ray irradiation, an electron beam irradiation, etc., or an undercoat treatment. The treatment for improving the adhesion of the high refractive index transparent thin film layer to the substrate may be performed. Further, an inorganic layer may be formed between the transparent laminate for electromagnetic wave shielding in order to improve the bending resistance and the like and further enhance the adhesion between the transparent polymer film and the high refractive index transparent thin film layer. Specific materials include
Nickel, chromium, gold, silver, platinum, zinc, zirconium, titanium, tungsten, tin, palladium and the like, or alloys composed of two or more of these materials, but are not particularly limited thereto. The thickness may be a thickness that does not impair the transparency, and is preferably about 0.02 nm to 10 nm. If the thickness is too small, a sufficient effect of improving the adhesion cannot be obtained, and if it is too large, the transparency is impaired. When the high refractive index transparent thin film layer is an oxide, part or all of the inorganic metal is actually a metal oxide, but there is no problem in its effect.
Before forming the high-refractive-index transparent thin film layer, dust-proofing treatment such as solvent cleaning or ultrasonic cleaning may be performed as necessary.

In the present invention, a high refractive index transparent thin film layer and a metal thin film layer are formed on one main surface of such a transparent polymer film. Since a plasma display emits strong near-infrared rays, it is in the near-infrared region of 800 to 1000.
It is necessary to cut off light in the wavelength region of nm. For example,
The light transmittance at least at 820 nm is preferably 10% or less, more preferably 5% or less.

The near-infrared ray can be cut off by reflection of free electrons of the metal. However, when the metal thin film layer is thickened, the visible light transmittance is lowered as described above, and when it is too thin, the near-infrared ray reflection is weakened. . Therefore, the visible light transmittance is increased and the overall thickness of the metal thin film layer is increased by stacking one or more layers of a laminated structure in which a metal thin film layer of a certain thickness is sandwiched between high refractive index transparent thin film layers. Can be. Further, by controlling the thickness of each layer, the visible light transmittance, the near-infrared transmittance, and the color tone can be changed within a certain range. If the visible light transmittance is low, the sharpness of the image is reduced when the display is installed. Therefore, the higher the visible light transmittance of the filter, the better, at least 50%.
And more preferably 55% or more.

The tint of the optical filter greatly affects the contrast and the like of the display. In the optical filter used in the present invention, green due to violet opacity is unsuitable, and it is required to be neutral gray or blue due to red-yellow opacity. For controlling the color tone, visible light transmittance and near-infrared transmittance for this purpose, it is generally easier to optically design a multilayer laminate.

That is, the light control film (B) is repeatedly laminated with a high refractive index transparent thin film layer (D) and a metal thin film layer (E) sequentially on one main surface of the transparent polymer film (C), The above effects can be obtained. The number of repeated laminations is 4 or more, preferably 4 to 6 times. That is,
Transparent polymer film / high refractive index transparent thin film layer / metal thin film layer / high refractive index transparent thin film layer / metal thin film layer / high refractive index transparent thin film layer / metal thin film layer / high refractive index transparent thin film layer / metal thin film layer / high Refractive index transparent thin film layer, or transparent polymer film / high refractive index transparent thin film layer / metal thin film layer / high refractive index transparent thin film layer / metal thin film layer / high refractive index transparent thin film layer / metal thin film layer / high refractive index transparent Thin film layer / metal thin film layer / high refractive index transparent thin film layer / metal thin film layer / high refractive index transparent thin film layer or transparent polymer film / high refractive index transparent thin film layer / metal thin layer / high refractive index transparent thin film layer / Metal thin film layer / High refractive index transparent thin film layer / Metal thin film layer /
High refractive index transparent thin film layer / metal thin film layer / high refractive index transparent thin film layer / metal thin film layer / high refractive index transparent thin film layer / metal thin film layer / high refractive index transparent thin film layer.

If the number of repetitions is three or less, the problem is that the interface for reflecting electromagnetic waves is small and it is difficult to achieve the required optical characteristics. By repeating a large number of times, the optical characteristics can be designed more strictly. However, when the number is seven or more times, the problem of difficulty in stable production increases.

In order to control the visible light transmittance, the transmittance of near-infrared light, and the color tone in a multilayer laminate of a high refractive index transparent thin film layer and a metal thin film layer, the refractive index and extinction of the transparent polymer film and thin film material are controlled. An optical design is performed using a vector method using coefficients, a method using an admittance diagram, and the like, and the thin film material, the number of layers, the film thickness, and the like of each layer are determined. In addition, film formation can be performed by controlling the number of layers, film thickness, and the like while observing optical characteristics.

The thickness of the metal thin film layer is determined optically and experimentally from the viewpoint of conductivity, optical characteristics, etc., and is not particularly limited as long as the required characteristics are obtained. However, it is preferable that the thickness be 4 nm or more because it is preferable that the thin film has a continuous state rather than an island structure due to conductivity and the like. If the metal thin film layer is too thick, transparency becomes a problem. Specific materials for the metal thin film include silver,
Examples include gold, platinum, palladium, nickel, chromium, zinc, zirconium, titanium, tungsten, tin, and the like, and alloys composed of two or more of these materials. Among them, silver is preferably used because it has excellent conductivity, infrared reflectivity, and visible light transmittance when laminated in multiple layers.
However, silver is not always excellent in chemical and physical stability, so it is degraded by environmental pollutants, heat, light, etc., so silver is stable in gold, platinum, palladium, indium, tin, etc. An alloy mainly composed of silver containing one or more kinds of metals is also preferably used. However, adding other metals to silver will impair its excellent conductivity,
If possible, it is preferable to use at least one of the layers without alloying silver.

When the adjacent high refractive index transparent thin film layer is an oxide, a part of the metal of the metal thin film layer may actually be a metal oxide, but is a very thin region. Therefore, there is no particular problem in optical design and film formation. Further, the first layer, the second layer, the third layer,... The nth layer (n ≧ 4) of the metal thin film
Are not necessarily the same thickness, and may not be the same metal or alloy. For the formation of the metal thin film layer, any of conventionally known methods such as sputtering, ion plating, vacuum deposition, plating and the like can be adopted.

The material of the transparent thin film forming the high refractive index transparent thin film layer is not particularly limited as long as it has transparency in the visible region and has an effect of preventing light reflection in the visible region of the metal thin film layer. It is not something to be done. Preferably, a material having a high refractive index to visible light of 1.6 or more, more preferably 1.7 or more, is used.
Specific materials for forming such a transparent thin film include:
Indium, titanium, zirconium, bismuth, tin,
Zinc, antimony, tantalum, cerium, neodymium,
Examples thereof include oxides of lanthanum, thorium, magnesium, gallium and the like, a mixture of these oxides, and zinc sulfide. These oxides or sulfides, even if there is a shift in the stoichiometric composition of the metal and oxygen or sulfur,
It does not matter if the optical characteristics are not largely changed. Above all, indium oxide or a mixture of indium oxide and tin oxide (ITO), in addition to transparency and refractive index,
It can be suitably used because it has a high deposition rate and good adhesion to the metal thin film layer. In addition, by using an oxide semiconductor thin film having relatively high conductivity such as ITO, the number of electromagnetic wave absorbing layers can be increased, and the conductivity of the electromagnetic wave shield can be increased.

The thickness of the high refractive index transparent thin film layer is determined optically and experimentally from the optical characteristics of the transparent polymer film, the thickness and optical characteristics of the metal thin film layer, the refractive index of the transparent thin film layer, and the like. Although not particularly limited, it is preferably from 5 nm to 200 nm, more preferably from 10 nm to 100 nm. Also, the first layer, second layer, third layer,... N-th layer (n ≧ n) of the high refractive index transparent thin film
5) is not limited to the same thickness and may not be the same transparent thin film material. Sputtering, ion plating, ion beam assist,
Any of conventionally known methods such as vacuum deposition and wet coating can be employed.

Among them, sputtering is suitable for controlling the film thickness and laminating a plurality of layers, and can easily and continuously form a metal thin film layer and a high-refractive-index transparent thin film layer. As will be described later in the examples as specific examples, a high-refractive-index transparent thin film layer mainly composed of indium oxide and a metal thin film layer composed of silver or an alloy containing silver are continuously formed by a sputtering method. The formation of the high-refractive-index transparent thin film layer mainly composed of indium oxide is performed by reactive sputtering using a metal target containing indium as a main component or a sintered body target containing indium oxide as a main component. In the reactive sputtering method, an inert gas such as argon is used as a sputtering gas and oxygen is used as a reactive gas, and a pressure of 0.1 to 20 mTorr and a direct current (DC) or high frequency (RF) magnetron sputtering method are used. it can. The oxygen gas flow rate is experimentally determined from the obtained deposition rate and the like, and is controlled so as to obtain a thin film having desired transparency.

The metal thin film layer made of silver or an alloy containing silver is formed by sputtering using silver or an alloy containing silver as a target. An inert gas such as argon is used as a sputtering gas, and the pressure is usually 0.1 to 20 mTorr,
Direct current (DC) or high frequency (RF) magnetron sputtering can be used.

The atomic composition of the high refractive index transparent thin film layer and the metal thin film layer formed by the above method is measured by Auger electron spectroscopy (AES), inductively coupled plasma method (ICP), Rutherford backscattering method (RBS) or the like. it can. The layer configuration and the film thickness can be measured by Auger electron spectroscopy observation in the depth direction, cross-sectional observation using a transmission electron microscope, or the like. The film thickness is controlled by clarifying the relationship between the film forming conditions and the film forming speed in advance and by monitoring the film thickness during the film formation using a quartz oscillator or the like.

In the present invention, the surface on which the multilayer film is formed is treated, and the compounds used for the treatment include triazineamine compounds, thiodipropionate compounds, mercaptobenzimidazole compounds, and benzimidazole compounds. There is at least one compound selected from the group consisting of compounds, benzotriazole compounds and thiocarbamates. These compounds are added to a suitable solvent, for example, water, a toluene solvent, an alcohol solvent, or an aqueous solution of 5% NaOH in an amount of 0.001 to 0.001
It is dissolved at a rate of 0.5% by weight, preferably 0.005 to 0.1% by weight, and the solution is applied to the surface on which the laminated film is formed and dried. After drying, the end face may be washed with water or an alcohol solvent. As a coating method, there are a dipping method, a spin coating method, a microgravure method, a reverse roll method, and the like, and each of them can be applied. When the specimen is small, the spin coating method can be suitably used.

Further, on the surface of the light control film including the silver thin film layer on which the multilayer film is formed, a transparent resin layer is provided after the above treatment.
Examples of the transparent resin layer include an acrylic resin, a silicon resin, a melamine resin, a urethane resin, and a fluorine resin. Particularly preferably, an ultraviolet curable resin is preferably used. For the formation of the transparent resin layer, a conventionally known method such as a printing method or a coating method can be selected and used depending on the resin to be used, and the thickness thereof is not particularly limited. About 50 μm. The transparent resin layer may be a single layer or a plurality of resin layers. Furthermore, in order to improve the stability of the thin film layer of the light control film including the silver thin film layer, the transparent resin is made of a triazineamine compound, a thiodipropionate compound, a percaptobenzimidazole compound, a benzimidazole compound. UV-curable resins containing at least one compound selected from the group consisting of benzotriazole-based compounds and thiocarbamates. Needless to say, even if the metal layer is a silver alloy, the treatment is effective for improving environmental resistance.

In the present invention, the above-mentioned light control film (B) is bonded on one main surface of the transparent substrate (A), and any adhesive or adhesive can be used for this bonding. . The pressure-sensitive adhesive or adhesive may be on the sheet or in a liquid state as long as it has a practical adhesive strength. After the pressure-sensitive adhesive sheet is attached, or after the adhesive is applied, the members are laminated by laminating each member. . The liquid material is an adhesive that is cured by being left at room temperature or heated after application and bonding, and examples of application methods include a bar coating method, a reverse coating method, a gravure coating method, a die coating method, and a roll coating method. Which one to westernize is selected in consideration of the type of adhesive, viscosity, application amount, and the like. The thickness of the pressure-sensitive adhesive or adhesive layer is not particularly limited, but is 0.5 μm to 50 μm, and preferably 1 μm to 30 μm.

In the present invention, as shown in FIGS. 3 and 4, an anti-Newton ring film is further laminated on at least one principal surface of the optical filter manufactured as described above, or A Newton ring layer may be formed. The anti-Newton ring film referred to in the present invention is a film in which the film is in contact with a highly rigid substrate, for example, a glass plate, by providing fine irregularities of about 0.1 to 10 μm on the surface of the transparent polymer film. In this case, the film can prevent Newton's ring from being generated between the film and the substrate. As the transparent polymer film that can be used for the above purpose, polyethylene terephthalate, polyether sulfone, polystyrene, polyethylene naphthalate, polyarylate, polyether ether ketone, polycarbonate, polypropylene, polyimide,
Triacetyl cellulose, polymethyl methacrylate and the like can be mentioned, but polyethylene terephthalate is preferably used because it has appropriate heat resistance.

As a method of providing minute irregularities on the surface,
There is a method of mechanically making the surface uneven, and a method of applying a filler (particle) having an appropriate particle size together with the resin.
In short, it is important to provide appropriate unevenness, and it is not always limited to the above method. The thickness of the anti-Newton ring film is limited only in terms of work and process, and is not limited in principle. In operation, 25 to 200 μm is appropriate.
Specifically, particles of a thermosetting or light-curing resin such as an acrylic resin, a silicone resin, a melamine resin, a urethane resin, or an alkyd resin, silica, melamine, particles of an inorganic compound or an organic compound such as acryl, Is dispersed on a substrate and applied and cured by a bar coating method, a reverse coating method, a gravure coating method, a die coating method, a roll coating method, or the like. The average particle size of the particles is 1
The non-glare layer or the anti-Newton ring layer has a haze of 0.5% to 5%, preferably 0.5% to 3%. When the haze is too small, the anti-Newton ring ability is insufficient, and when the haze is too large, the parallel light transmittance is reduced, and the visibility of the display may be deteriorated.

Further, the anti-Newton ring film has an effect of preventing external light from being reflected on the surface of the display, and both anti-Newton ring performance and anti-glare performance can be expected.

Thus, the constitution of the optical filter for display in the present invention is as follows: transparent substrate (A) 20 / light control film (B) 10, anti-Newton ring film / transparent substrate (A) as shown in FIG. ) / Light control film (B), transparent substrate (A) / light control film (B) /
An anti-Newton ring film, an anti-Newton ring film 80 / a transparent substrate (A) 20 / a light control film (B) 10 / an anti-Newton ring film 80 as shown in FIG. 3 can be obtained. In addition,
An optical filter can be formed by bonding a transparent substrate and a light control film or an anti-Newton ring film with an adhesive or an adhesive, but instead of bonding an anti-Newton ring film, as shown in FIG. It is also possible to form the anti-Newton ring layer 80 on the substrate surface or the light control film surface by a coating method. The anti-Newton ring layer in this case is a layer having the same function and effect as the above-mentioned anti-Newton ring film.

In the present invention, it is easily understood by those skilled in the art that the introduction of an organic or inorganic dye for adjusting the tint or chromaticity or for absorbing near-infrared rays is effective for improving the performance. There will be. At this time, as a method for introducing the dye, it goes without saying that the dye can be kneaded into a film or contained in a coating resin and applied to a transparent substrate.

The anti-reflection treatment can be performed instead of or in combination with the anti-Newton ring treatment or the anti-glare treatment, and the surface can be subjected to a hydrophobic anti-fouling treatment. Properly providing a conductive layer for this would be within the purview of those skilled in the art.

[0037]

Next, the present invention will be described in detail with reference to examples. The present invention is not limited by these. Note that the thicknesses of the thin films shown in the following examples and comparative examples are values obtained from film forming conditions, and are not actually measured film thicknesses.

Example 1 A polyethylene terephthalate film (thickness: 50 μm) as a transparent polymer film
m) on one main surface, indium as a target, and an argon / oxygen mixed gas (total pressure 266 mP) as a sputtering gas.
a: an indium oxide thin film using oxygen partial pressure of 80 mPa), silver as a target, silver thin film using an argon gas (total pressure of 266 mPa) as a sputtering gas, and an indium oxide thin film 40 by a magnetron DC sputtering method.
nm, silver thin film 12 nm, indium oxide thin film 70 nm,
Silver thin film 10 nm, indium oxide thin film 70 nm, silver thin film 12 nm, indium oxide thin film 70 nm, silver thin film 10 n
m, and an indium oxide thin film of 30 nm. Here, 0.01% by weight of benzimidazole was added to the surface of the laminated film.
The dissolved ethanol solution is applied and dried, and an acrylic resin is further formed as a transparent resin layer by screen printing.
The light modulating film of the present invention was formed by forming a film having a thickness of μm and curing the resin with ultraviolet rays. Next, the above-mentioned light control film was bonded to a 2 mm thick PMMA plate (both sides flat) so that the transparent resin was on the outside, to produce an optical filter for a display of the present invention. An optical filter was obtained.

Example 2 On one main surface of a polyethylene terephthalate film (thickness: 50 μm), indium oxide was used as a target, and a mixed gas of argon and oxygen (total pressure 266 mPa: oxygen partial pressure 3 mPa) was used as a sputtering gas. Then, an indium oxide thin film, a silver thin film using an argon gas (total pressure: 266 mPa) as a sputtering gas, a silver thin film as a target, an indium oxide thin film by a magnetron DC sputtering method, and an indium oxide thin film by a magnetron DC sputtering method. 40 nm, silver thin film 10 nm, indium oxide thin film 70 nm, silver thin film 10 n
m, an indium oxide thin film 70 nm, a silver thin film 10 nm, an indium oxide thin film 60 nm, a silver thin film 8 nm, an indium oxide thin film 40 nm, a silver thin film 12 nm, and an indium oxide thin film 20 nm, stacked in this order, and further, benzimidazole thiol was added to the multilayer film laminated surface. A 0.02% by weight ethanol solution was applied and dried. Next, as a transparent resin layer, an acrylic resin was formed to a thickness of 20 μm by screen printing, and the resin was cured by ultraviolet rays, thereby producing a light control film of the present invention. Next, a PMM with a thickness of 2 mm
An optical filter for a display of the present invention was prepared by laminating the light control film on an A plate (both flat surfaces) so that the transparent resin was on the outside, and an optical filter for a display as shown in FIG. 2 was obtained.

Example 3 On one main surface of a polyethylene terephthalate film (thickness: 50 μm), indium oxide (containing 5% by weight of tin oxide) was used as a target, and an argon / oxygen mixed gas (total pressure: 266 mPa) was used as a sputtering gas. :
Using an oxygen partial pressure of 4 mPa), the indium oxide thin film is
A silver thin film was formed by using silver as a target, an argon gas (total pressure of 266 mPa) as a sputtering gas, an indium oxide thin film by a magnetron DC sputtering method, and a silver thin film of 40 nm and a silver thin film of 10 nm by a magnetron DC sputtering method. Indium thin film 70 nm, silver thin film 10 nm, indium oxide thin film 70 n
m, silver thin film 10 nm, indium oxide thin film 60 nm, silver thin film 6 nm, indium oxide thin film 40 nm, silver thin film 6 n
m, an indium oxide thin film of 40 nm, a silver thin film of 6 nm, and an indium oxide thin film of 20 nm in this order, and an ethanol solution in which benzotriazole was dissolved at 0.05% by weight was applied to the multilayer film laminated surface by a dip method and dried. Next, an acrylic resin was formed to a thickness of 20 μm by screen printing as a transparent resin layer, and the resin was cured by ultraviolet rays. Next, it was bonded to a 2 mm thick PMMA plate (both sides flat).

Further, 3 g of thermosetting varnish (SF-C-335) manufactured by Dainippon Ink and Chemicals, Inc. was applied to one main surface of the polyethylene terephthalate film (thickness: 50 μm).
To a toluene / methyl ketone (10: 1) mixed solvent 10
0 g, applied, air dried, cured at 150 ° C. for 20 seconds to form an anti-Newton ring film having a thickness of 1 μm to form an anti-Newton ring film, which was laminated to form an anti-Newton ring film. / Acrylic plate / Light control film / Anti-Newton ring film
The optical filter for a display shown in FIG. 3 was obtained.

Example 4 Example 1 was repeated except that a triazineamine compound was used instead of benzimidazole.
An optical filter for a display was produced in the same procedure as described above, and an optical filter for a display shown in FIG. 2 was obtained.

Example 5 An optical filter for a display was produced in the same procedure as in Example 1 except that thiocarbamate was used instead of benzimidazole, and an optical filter for a display shown in FIG. 2 was obtained. Was.

Comparative Example 1 An optical filter for a display was manufactured in the same procedure as in Example 1 except that the surface treatment of the laminated film was not performed.

Comparative Example 2 An optical filter for a display was manufactured in the same procedure as in Example 2 except that the surface treatment of the laminated film was not performed.

Comparative Example 3 An optical filter for a display was manufactured in the same procedure as in Example 3 except that the surface treatment of the laminated film was not performed.

Visible light transmittance (Tvis) and near-infrared light transmittance The parallel light transmittance of 300 to 1000 nm was measured with a spectrophotometer (U-3400) manufactured by Hitachi, Ltd. Tvis was calculated from the transmittance determined here. The near-infrared transmittance was evaluated at 820 nm, 850 nm, and 1000 nm. The above results are shown in [Table 1].

[0048]

[Table 1] As is clear from Table 1, Examples 1 to 5 and Comparative Examples 1 to 3 have a large infrared ray suppressing ability.

Next, the optical filters produced in Examples 1 to 5 and Comparative Examples 1 to 3 were left in a wet heat tank at 60 ° C. and a relative humidity of 90% for 500 hours, taken out, and examined for optical characteristics. The results are shown in [Table 2].

[0050]

[Table 2]

In Examples 1 to 5, there was no particular change in appearance, but in Comparative Examples 1 to 3, the entire surface of the filter was 5%.
After 00 hours, it turned white. From Examples 1 to 5 and Comparative Examples 1 to 3, it can be seen that the optical filter for a display of the present invention not only has excellent near-infrared shielding ability but also has excellent environmental resistance.

[0052]

As described above, according to the present invention, the surface of the laminated film of the light control film has a triazineamine compound, a mercaptobenzimidazole compound, a thiodipropionate compound, a benzimidazole compound, a benzotriazole compound. By being treated with at least one compound selected from the group consisting of a compound and a thiocarbamate, the composition has excellent environmental resistance,
In addition, an optical filter having excellent near-infrared blocking ability can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of the configuration of a light control film used for an optical filter for a display according to the present invention.

FIG. 2 is a cross-sectional view illustrating an example of a configuration of an optical filter for a display according to the present invention.

FIG. 3 is a cross-sectional view illustrating an example of the configuration of an optical filter for a display according to the present invention.

FIG. 4 is a sectional view showing an example of the configuration of the optical filter for a display of the present invention.

[Explanation of symbols]

Reference Signs List 10 light control film 20 transparent substrate 30 transparent polymer film 40 metal thin film layer (silver or silver-based alloy thin film layer 9 50 high refractive index transparent thin film layer 60 transparent resin layer 70 adhesive layer or adhesive layer 80 anti Newton ring film or anti-Newton ring layer 90 Treated surface

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Masato Koyama 2-1-1 Tango-dori, Minami-ku, Nagoya-shi, Aichi Mitsui Toatsu Chemicals Co., Ltd.

Claims (5)

[Claims] 1. A display filter comprising at least one light control film (B) laminated on one main surface of a transparent substrate (A), wherein the light control film (B) is a transparent polymer film ( At least one high refractive index transparent thin film layer (D) and a metal thin film layer (E) are sequentially formed on one main surface of C).
(D) / (E) is repeated four or more times as a repeating unit, and at least a high-refractive-index transparent thin film layer (D) is further laminated thereon, and a transparent resin layer (F) is further formed thereon. A film having a visible light transmittance of 50% or more and a light transmittance of 10% or less for light having a wavelength of 820 nm to 1000 nm before forming the transparent resin layer (F). The laminated film surface has at least one compound selected from the group consisting of a triazineamine compound, a mercaptobenzimidazole compound, a thiodipropionate compound, a benzimidazole compound, a benzotriazole compound and a thiocarbamate. Optical filters for displays that have been treated with. 2. The high-refractive-index transparent thin film layer (D) is mainly composed of indium oxide.
The optical filter for a display according to the above. 3. The optical filter for a display according to claim 1, wherein the metal thin film layer (E) is silver or an alloy mainly containing silver. 4. An optical filter for a display, wherein an anti-Newton ring film is further attached to at least one main surface of the optical filter according to claim 1, or an anti-Newton layer is formed. 5. The optical filter for a display according to claim 1, which can be suitably used for a plasma display.