JP2007017742A - Filter for display, and the display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter for a display free of changes in the spectral characteristics due to degradation of a near infrared absorbent, even under long-time use, thereby keeping its transparency, and to provide a display to which the filter for a display has been applied. <P>SOLUTION: The filter for a display has a near-infrared and ultraviolet absorbing layer, where at least a near-infrared absorbent and an ultraviolet absorber are contained in the same layer. Before and after the irradiation of the filter for display, with 255 W/m<SP>2</SP>of ultraviolet light at 43°C for 100 hours, the difference in haze value is ≤3%, and the maximum difference in transmission for a light flux having 800-1,100 nm is ≤3%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a display filter and a display using the same.
More specifically, the present invention relates to a display filter and a display in which the near-infrared absorber does not deteriorate or the transparency does not deteriorate even in an environment where it is directly exposed to external light.

In recent years, electronic displays such as CRTs (CRTs), LCDs (Liquid Crystal Displays), PDPs (Plasma Displays), organic / inorganic EL displays, FEDs (Field Emission Displays) have been used as display panels for various electronic devices.
A filter is installed on the front surface of such an electronic display in order to remove unnecessary light-emitting components and make the display color clear. For example, in a plasma display, near infrared rays of about 800 to 1100 nm are generated by plasma discharge of a mixed gas of xenon and neon, and the generated near infrared rays cause peripheral devices to malfunction. For this reason, in the plasma display, a filter having a function of absorbing and removing near infrared rays is installed on the front surface of the display. The above-mentioned near-infrared absorption and removal function is often expressed by a near-infrared absorbing layer containing a near-infrared absorber in a resin, but some near-infrared absorbers are decomposed by ultraviolet rays contained in sunlight. Some are promoted. Therefore, it was necessary to provide the display filter with a function of cutting out ultraviolet rays (light resistance).

  Various studies have been made to solve this problem. For example, Patent Document 1 describes a plasma display filter in which an ultraviolet absorbing layer for protecting the near infrared absorbing layer is separately provided. However, while this filter improves the light resistance of the near-infrared absorbing layer, there are problems that increase the thickness of the film due to the increase in layers, complicate the manufacturing process, and increase the cost. Patent Document 2 discloses a near-infrared absorbing film in which a near-infrared absorbing layer is formed on at least one surface of a base film via an adhesive property modification layer, and an ultraviolet absorber is contained in the base film. A near infrared absorbing film is described. Although this method does not increase the number of layers, since the base film is formed at a very high temperature, there is a problem that only an ultraviolet absorber having high heat resistance can be used. On the other hand, Patent Document 3 proposes a water-repellent ultraviolet and infrared absorbing glass including an ultraviolet and infrared absorbing thin film in which an infrared absorber and an ultraviolet absorber coexist.

JP 11-249576 A JP 2005-31654 A Japanese Patent Laid-Open No. 7-291667

The present inventors examined a method for obtaining a display filter by a method in which an infrared absorber and an ultraviolet absorber coexist, and the filter obtained by the method decreases the transparency of the display filter when used for a long time. It became clear. As a result of further investigation, it was found that the ultraviolet absorbent bleeded out on the surface of the ultraviolet and infrared absorption layer of the filter after long-term use. In particular, when a resin base material is used as the base material, it has moisture permeability and gas permeability, so that it easily receives external factors, and the ultraviolet absorbent tends to bleed out more easily. Patent Document 3 does not mention a decrease in transparency or bleed-out caused by long-term use.
The present invention has been made in consideration of the above problems, and a display filter that does not cause a change in spectral characteristics attributed to deterioration of a near-infrared absorber even under long-term use and does not deteriorate transparency. And a display to which the display filter is applied.

The display filter of the present invention is a display filter including a near-infrared ultraviolet absorbing layer containing at least a near-infrared absorber and an ultraviolet absorber in the same layer, and the display filter has an ultraviolet ray of 255 W / m ² . The difference in haze value before and after the irradiation of 100 ° C. at 43 ° C. for 100 hours is 3% or less, and the maximum value of the difference in light transmittance at 800 to 1100 nm is 3% or less.

  The display filter of the present invention preferably has a light transmittance of 10% or less in the entire wavelength region of less than 380 nm from the viewpoint of the ultraviolet absorption function.

In the display filter of the present invention, the molecular weight of the ultraviolet absorber is preferably 400 or more, particularly preferably 10,000 or more.
When the ultraviolet absorbent has such a molecular weight, the ultraviolet absorbent becomes difficult to move in the near-infrared ultraviolet absorbing layer. This is because it becomes difficult to bleed out to the surface, and as a result, a decrease in transparency can be prevented.

In the display filter of the present invention, the near-infrared ultraviolet absorbing layer preferably further contains a light stabilizer having a molecular weight of 300 or more, and in particular, the molecular weight of the light stabilizer is 10,000 or more. preferable.
When the light stabilizer is contained, it is possible to more effectively prevent a decrease in light transmittance due to long-term use. Further, when the molecular weight of the light stabilizer is large, it is possible to prevent the light stabilizer from bleeding out from the near-infrared ultraviolet absorbing layer to the surface thereof, as in the case of the ultraviolet absorber.

  In order to give various functions to the display filter, one or more functions of color tone adjustment function, electromagnetic wave shielding function, antireflection function, antiglare function, antifouling function, neon light absorption function It is preferable to further have one layer or two or more layers.

  The display according to the present invention is characterized in that the display filter is disposed on a display surface of the display.

  The display filter of the present invention includes a layer in which the near-infrared absorber and the ultraviolet absorber are contained in the same layer, so that the filter film is thin, the manufacturing process is simplified, and it can be manufactured at low cost. Good processability and productivity. Moreover, since the ultraviolet absorber does not include a step of exposing to a high temperature environment, the type of the ultraviolet absorber is not easily limited. Furthermore, it is excellent in environmental stability, and there is an effect that the spectral characteristics attributed to the deterioration of the near-infrared absorber does not occur even under long-term use, and the decrease in transparency is suppressed. In addition, the present invention can provide a display using such a display filter.

1 to 4 are cross-sectional views illustrating a laminated structure of a display filter according to the present invention.
The display filter according to the present invention is most basically a laminate 4 composed of a transparent substrate 2 and a near-infrared ultraviolet absorbing layer 3 as indicated by reference numeral 1 in FIG. The transparent substrate 2 may be subjected to a treatment for improving adhesiveness that can be performed during lamination. Moreover, you may have an adhesive bond layer between the transparent base material 2 and the near-infrared absorption layer 3 as needed.

  The display filter of the present invention may use a functional layer known in the field of optical filters instead of the transparent substrate 2. Examples of the functional layer include one or two or more of an electromagnetic shielding function, a color tone adjustment function, an antireflection function, an antiglare function, an antifouling function, an ultraviolet absorption function, and a neon light absorption function. The layer more than a layer can be mentioned.

In the present invention, for example, as shown in FIG. 2, a functional layer 5 known in the field of optical filters as necessary on a laminate 4 composed of a transparent substrate 2 and a near-infrared ultraviolet absorber layer 3. Can be further provided as the display filter 11. The functional layer 5 is a single layer or two or more layers having one or two or more of an electromagnetic wave shielding function, a color tone adjusting function, an antireflection function, an antiglare function, an antifouling function, and an ultraviolet absorbing function. It is preferable.
In FIG. 2, the functional layer 5 is laminated on the near-infrared ultraviolet absorbing layer 3, but the laminated structure is not limited to these. For example, as shown in FIG. A structure in which the layer 5 is laminated and the near-infrared ultraviolet absorbing layer 3 is laminated thereon may be used. Moreover, as FIG. 4 shows, the structure where another functional layer 5 'was laminated | stacked on the near-infrared ultraviolet absorption layer 3 in FIG. 3 may be sufficient. Moreover, the laminated structure of the display filter of the present invention is not limited to the above examples.
Hereinafter, each layer of the display filter will be described.

[Near-infrared UV absorbing layer]
The near-infrared ultraviolet absorbing layer of the present invention comprises a binder resin in addition to at least a near-infrared absorber and an ultraviolet absorber, and further contains additives such as a light stabilizer as necessary.

(Near infrared absorber)
The near-infrared absorber used in the present invention can be used as a near-infrared absorbing layer of a display filter, that is, it can be blended into a binder resin, and a near-infrared ultraviolet absorbing layer containing this near-infrared absorbing agent has Any compound can be selected as long as it can absorb a wavelength of at least 800 to 1100 nm.

Specific examples of near-infrared absorbers having a maximum absorption wavelength in a wavelength region of at least 800 to 1100 nm include polymethine compounds, cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, naphthoquinone compounds, anthraquinone compounds. , Dithiol compounds, immonium compounds, diimonium compounds, aminium compounds, pyrylium compounds, cerium compounds, squarylium compounds, copper complexes, nickel complexes, dithiol metal complexes organic near infrared absorbing dyes Inorganic near-infrared absorption colors such as tin oxide, indium oxide, magnesium oxide, titanium oxide, chromium oxide, zirconium oxide, nickel oxide, aluminum oxide, zinc oxide, iron oxide, ammonium oxide, lead oxide, bismuth oxide, lanthanum oxide It can be used in combination one kind or two or more. Among these, anthraquinone compounds, naphthoquinone compounds, phthalocyanine compounds, and diimmonium compounds are preferable.
The type and amount of addition may be appropriately selected according to the absorption wavelength and absorption coefficient of the near-infrared absorbing dye, the color tone, the transmittance required for the display front plate, and the like.
The blending amount of the near-infrared absorber is preferably 0.1 to 40% by weight, more preferably 1 to 20% by weight, based on the solid content of the entire near-infrared ultraviolet absorbing layer.

(UV absorber)
Examples of the ultraviolet absorber used in the present invention include organic ultraviolet absorbers. Any known organic ultraviolet absorber can be used.
UV absorption from the viewpoint of preventing the ultraviolet absorber present in the near infrared ultraviolet absorbing layer from bleeding out to the surface from the near infrared ultraviolet absorbing layer and using it for a long time, resulting in a decrease in transparency. It is preferable that the molecular weight of the agent is large. This is because when the molecular weight of the ultraviolet absorbent is large, the ultraviolet absorbent becomes difficult to move in the near infrared ultraviolet absorbing layer.

There are low molecular weight compound types and polymer types of organic ultraviolet absorbers, and either of them may be used, or they may be used in combination.
The low molecular compound type organic ultraviolet absorber is composed of a low molecular compound and is different from a polymer. Such an ultraviolet absorber is not particularly limited, but may be benzotriazole from the viewpoints of solubility in various organic solvents, compatibility with various binder resins, ultraviolet absorption coefficient, durability, and synergistic effect with a light stabilizer. , Benzophenone and cyclic imino ester UV absorbers are preferred. Two or more ultraviolet absorbers may be used in combination.

A benzotriazole type ultraviolet absorber, a triazine type ultraviolet absorber, a benzoxazine type ultraviolet absorber or a benzophenone type ultraviolet absorber is used. Of these, triazine-based ultraviolet absorbers that have large steric hindrance and are difficult to bleed out are preferred.
Examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole and 2- (2′-hydroxy-3 ′-(3,4,5,6-tetrahydrophthalimidomethyl). ) -5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy-5′-tert-octylphenyl) ) Benzotriazole, 2- (3'-tert-butyl-5'-methyl-2'-hydroxyphenyl) -5-chlorobenzotriazole, 2,2'-methylenebis (4- (1,1,3,3- Tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2′-hydroxy-3 ′, 5′-bis (α, α-dimethylben) L) phenyl) -2H-benzotriazole, 2- (3 ′, 5′-di-tert-amyl-2′-hydroxyphenyl) benzotriazole, 5-trifluoromethyl-2- (2-hydroxy-3- ( 4-methoxy-α-cumyl) -5-tert-butylphenyl) -2H-benzotriazole and the like. Among them, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′-(3,4,5,6-tetrahydrophthalimidomethyl) -5′-methylphenyl) Benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole, 2- (3 '-Tert-Butyl-5'-methyl-2'-hydroxyphenyl) -5-chlorobenzotriazole is preferred.
As the triazine-based ultraviolet absorber, hydroxyphenyltriazine-based, for example, trade name TINUVIN400 (manufactured by Ciba Specialty Chemicals) is preferable.
Examples of the benzoxazine-based ultraviolet absorber include 2-methyl-3,1-benzoxazin-4-one, 2-butyl-3,1-benzoxazine-4-one, 2-phenyl-3,1-benzoxazine -4-one, 2- (1- or 2-naphthyl) -3,1-benzoxazin-4-one, 2- (4-biphenyl) -3,1-benzoxazin-4-one, 2,2 ′ -Bis (3,1-benzoxazin-4-one), 2,2'-p-phenylenebis (3,1-benzoxazin-4-one, 2,2'-m-phenylenebis (3,1- Benzoxazin-4-one), 2,2 ′-(4,4′-diphenylene) bis (3,1-benzoxazin-4-one), 2,2 ′-(2,6 or 1,5-naphthalene) ) Bis (3,1-benzoxazin-4-one), 1,3 5-tris (3,1-benzoxazin-4-one-2-yl) benzene and the like are mentioned, among which 2,2′-p-phenylenebis (3,1-benzoxazin-4-one) is preferable. .
Examples of the benzophenone ultraviolet absorber include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2,4-dihydroxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone and the like can be mentioned, among which 2-hydroxy-4-n-octoxybenzophenone is preferable.
These ultraviolet absorbers may be used alone or in combination of two or more.

When the low molecular weight compound type ultraviolet absorber is used, the molecular weight is preferably 400 or more, particularly 500 or more. When the molecular weight is less than 400, the ultraviolet absorber is easy to move in the near infrared ultraviolet absorbing layer, and when the display is used for a long time, the ultraviolet absorber present in the near infrared ultraviolet absorbing layer is It tends to bleed out on the surface of the UV absorbing layer over time, and transparency tends to decrease.
Further, the molecular weight of the low molecular compound type ultraviolet absorber is preferably 2000 or less. When the molecular weight is larger than 2000, the amount of the UV absorber necessary for obtaining the UV absorbing effect may be increased. As a result, the transparency may be lowered or the required amount may not be compatible. Performance may not be obtained.

The polymer type UV absorber used in the present invention refers to a UV absorber made of a polymer. Examples thereof include a polymer obtained by polymerizing a raw material monomer having at least a residue of a compound used as an ultraviolet absorber and a carbon-carbon double bond for forming a polymer main chain. Here, the residue of the compound used as the ultraviolet absorber may be bonded to carbon constituting the carbon-carbon double bond via a linking group.
The polymer type ultraviolet absorber has a structure in which the residue of a low molecular weight compound used as an ultraviolet absorber is suspended in a pendant form on the main chain of a polymer formed by polymerizing a carbon-carbon double bond.

  Here, the residue of the compound used as the ultraviolet absorber is an organic group from which at least one hydrogen or functional group in the compound used as the ultraviolet absorber is removed. As a residue of a compound used as an ultraviolet absorber, the low molecular compound type ultraviolet absorber described above such as a benzotriazole ultraviolet absorber, a triazine ultraviolet absorber, a benzoxazine ultraviolet absorber or a benzophenone ultraviolet absorber The residue of the compound used as is mentioned.

Although it does not specifically limit as said coupling group, For example, C1-C10, such as a methylene group, ethylene group, trimethylene group, propylene group, tetramethylene group, pentamethylene group, hexamethylene group, octamethylene group, decamethylene group, etc. And an alkylene group having 1 to 10 carbon atoms such as an oxymethylene group, an oxyethylene group, and an oxypropylene group, an ester bond, an amide bond, an ether bond, and a urethane bond.
Further, the polymer has at least a residue of a compound used as an ultraviolet absorber and a monomer having a carbon-carbon double bond, and at least a carbon-carbon double without a residue of a compound used as an ultraviolet absorber. It may be a copolymer with a monomer having a bond.

The molecular weight of the polymer type ultraviolet absorber is preferably 10,000 or more, more preferably 50,000 or more. In the case of a polymer type, the molecular weight means a weight average molecular weight.
When the molecular weight is 10,000 or more, the ultraviolet absorber becomes difficult to move in the near-infrared ultraviolet absorbing layer, so that the ultraviolet absorber present in the near-infrared ultraviolet absorbing layer is present on the surface of the near-infrared ultraviolet absorbing layer. It is easy to prevent bleeding out over time, and it is possible to prevent a decrease in transparency. In addition, the effect is often higher than that of the low molecular compound type because it is more difficult to bleed out.

  The molecular weight of the polymer type ultraviolet absorber is preferably 400,000 or less. When the molecular weight is larger than 400,000, the ultraviolet absorbing ability per unit volume is relatively small, so that the content of the ultraviolet absorber necessary for obtaining the ultraviolet absorbing effect is increased, and as a result, the transparency is lowered. There are cases where there is a demerit that the required amount cannot be compatible and satisfactory performance cannot be obtained.

  From the viewpoint of making the ultraviolet absorber difficult to bleed out, it is preferable to consider the steric hindrance of the ultraviolet absorber and the similar structure or similar properties to the binder resin in addition to the molecular weight. The greater the steric hindrance of the UV absorber, the more difficult it is to bleed out. Moreover, as a similar structure with a binder resin, for example, there are cases in which aromatic groups have each other, and there are cases in which similar properties have the same degree of polarity with each other.

The blending amount of the ultraviolet absorber is preferably 0.5% by weight to 70% by weight with respect to the solid content of the entire near infrared ultraviolet absorbing layer. More preferably, it is 2 to 50% by weight, and particularly preferably 3 to 40%. When the blending amount is less than 0.5% by weight, it is difficult to obtain sufficient ultraviolet absorptivity. On the other hand, if the blending amount is more than 70% by weight, the ultraviolet absorber tends to bleed out and the transparency may be lowered. In addition, the near-infrared absorber may be easily deteriorated, and the near-infrared absorption and removal function may be insufficient.
(Binder resin)

  The binder resin used in the near infrared ultraviolet absorption layer of the present invention needs to have transparency. The transparency of the binder resin is not particularly limited as long as it is transparent to humans, but the haze according to JIS K7105 is preferably 5 or less, and particularly preferably 3 or less. For example, an acrylic resin, a urethane resin, a fluorine resin, a polyester resin, or the like can be used. Among them, those having a molecular weight of 10,000 or more are preferable, and particularly preferably 20000 or more. This is because the bleeding out of the ultraviolet absorber can be effectively suppressed.

  The blending amount of the binder resin is preferably 30 to 95% by weight with respect to the solid content of the entire near-infrared ultraviolet absorbing layer.

(Light stabilizer)
The light stabilizer used in the present invention is a component of a near-infrared absorber such as a near-infrared absorber by catalytically capturing and stabilizing radicals generated inside the near-infrared ultraviolet absorbing layer when exposed to light (ultraviolet rays). It is a component that can prevent deterioration and stably maintain the near infrared absorption function. Any known light stabilizers can be used. Among them, hindered amine light stabilizers are preferred in terms of solubility in various organic solvents, compatibility with various binder resins, durability, and synergistic effects with ultraviolet absorbers. (HALS) is preferred. Examples of the hindered amine light stabilizer include dibutylamine, 1,3,5-triazine, N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine, N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5- Triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], Bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, bis (2,2 , 6,6-tetramethyl And compounds such as -4-piperidyl) sebacate.

  The molecular weight of the light stabilizer is preferably 300 or more, more preferably 500 or more, and particularly preferably 10,000 or more, from the viewpoint of suppressing the light stabilizer from bleeding out when used for a long time. Further, the blending amount of the light stabilizer is preferably 0.1% by weight to 50% by weight with respect to the solid content of the entire near-infrared ultraviolet absorbing layer. More preferably, it is 0.5 to 40% by weight. When the blending amount is less than 0.1% by weight, a sufficient light stabilizer effect cannot be obtained. On the other hand, if the blending amount is more than 70% by weight, the light stabilizer tends to bleed out and the transparency may be lowered.

  The near-infrared ultraviolet absorbing layer of the present invention may contain additives as necessary in addition to the above-described ultraviolet absorber, near-infrared absorber, binder resin and light stabilizer. Further, a neon light absorbing dye and a color tone adjusting dye, which will be described later, may be included to serve also as a neon light absorbing function and / or a color tone adjusting function. As the additive, a conventionally known additive or the like generally used for a resin composition for forming a film, a coating film or the like can be used. For example, a leveling agent, an antifoaming agent, a sagging inhibitor, an antioxidant. , Viscosity modifiers, metal deactivators, peroxide decomposers, plasticizers, antistatic agents and the like.

  The near-infrared ultraviolet absorbing layer of the present invention can be formed by any appropriate method, but it causes deterioration of pigments, binder resins, etc. in order to prevent deterioration of the near-infrared absorber and binder resin. It is preferably formed by a method that does not use harmful components, or uses a small amount, and does not require excessive temperature and pressure. As one of such methods, for example, a near-infrared absorber and an ultraviolet absorber are added to a resin solution obtained by dissolving a binder resin in an organic solvent, or a resin wetted or softened with a solvent, and sufficiently dispersed. The composition obtained by making it apply | coat or extrude on the transparent base material mentioned later, is dried as needed, and also it hardens | cures with a heat | fever, an electron beam, etc. as needed, and the method of forming is mentioned.

  The solvent for dissolving the binder resin and dispersing the near-infrared absorber and the ultraviolet absorber is not particularly limited as long as the ultraviolet absorber, the near-infrared absorber, and the binder resin can be uniformly dissolved or dispersed. . For example, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, benzene, toluene, xylene, methanol, ethanol, isopropanol, chloroform, tetrahydrofuran, N, N-dimethylformamide, acetonitrile, trifluoropropanol, n-hexane, or Although n-heptane or water etc. are mentioned, things other than these may be sufficient.

  Examples of the method for applying the composition for forming a near-infrared ultraviolet absorbing layer on a transparent substrate include dipping, spraying, brush coating, Mayer bar coating, doctor blade coating, gravure coating, gravure reverse coating, kiss reverse coating, 3 Various coating methods such as roll reverse coating, slit reverse die coating, die coating, or comma coating can be used.

  The thickness of the near-infrared ultraviolet absorbing layer is not particularly limited as long as it is appropriately set depending on the intended use. For example, it is preferable to set the thickness at the time of drying to 0.5 to 1000 μm. More preferably, it is 1-100 micrometers. More preferably, it is 1-50 micrometers, Most preferably, it is 1-30 micrometers.

  When the near-infrared ultraviolet absorbing layer is applied to the front surface of a plasma display panel, in which a display filter is a typical application, the near-infrared region generated when the plasma display panel emits light using xenon gas discharge, that is, It absorbs a wavelength range of 800 nm to 1100 nm, and the near infrared transmittance of the band is preferably 20% or less, more preferably 15% or less. At the same time, the near-infrared absorbing layer desirably has a sufficient light transmittance in the visible light region, that is, in the wavelength region of 380 nm to 780 nm.

[Transparent substrate]
The transparent base material used in the display filter of the present invention is not particularly limited as long as a near-infrared ultraviolet absorbing layer can be laminated. However, the resin can be reduced in weight and can be continuously wound up with high efficiency. It is preferable that the equipment. Examples of the resin base material include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefins such as cyclic polyolefin, polyethylene, polypropylene and polystyrene, and vinyl resins such as polyvinyl chloride and polyvinylidene chloride. And a film made of a resin such as polycarbonate, acrylic resin, triacetyl cellulose (TAC), polyethersulfone, or polyetherketone, which may be used alone or in layers of the same or different types. it can.

  The transparency of the transparent substrate is preferably such that the light transmittance in the visible region is 80% or more when the transparent substrate is a single layer. Further, having transparency is preferably colorless and transparent, but is not necessarily colorless and transparent, and may be colored and transparent as long as the object of the present invention is not hindered. Although it is preferable that the light transmittance in the visible region is as high as possible, the final product needs to have a light transmittance in the visible region of 50% or more. A substrate having a light transmittance of 80% is suitable for the purpose. Since the higher the light transmittance is, the more transparent substrates can be laminated, the light transmittance of a single layer of the transparent substrate is more preferably 85% or more, and most preferably 90% or more. Reducing the thickness is also an effective means for improving the light transmittance.

  The thickness of the transparent substrate is not particularly limited as long as the transparency is satisfied, but it is preferably in the range of about 12 μm to 300 μm from the viewpoint of workability. When the thickness is less than 12 μm, the transparent substrate is too flexible, and stretch and wrinkles are likely to occur due to the tension during processing. In addition, when the thickness exceeds 300 μm, the flexibility of the film decreases, and continuous winding in each process becomes difficult, and the workability when laminating a plurality of transparent substrates is greatly inferior. There is also.

[Color tone adjustment function layer]
In the display filter of the present invention, the color tone adjusting functional layer that can be added to the near-infrared ultraviolet absorbing layer or the laminate thereof is for improving the color purity of light emitted from the panel, the color reproduction range, the display color when the power is turned off, and the like. This is for adjusting the color of the display filter. The color tone adjusting functional layer is a known dye having a maximum absorption wavelength in the visible region of 380 to 780 nm, optionally combined with a dye according to the purpose, and used as a coating liquid together with a binder resin. It can be formed similarly. Known pigments that can be used in the color tone adjusting functional layer are described in JP-A Nos. 2000-275432, 2001-188121, 2001-350013, and 2002-131530. These dyes can be preferably used. In addition, other dyes such as anthraquinone, naphthalene, azo, phthalocyanine, pyromethene, tetraazaporphyrin, squarylium, and cyanine that absorb visible light such as yellow light, red light, and blue light. Can be used.

[Electromagnetic wave shielding functional layer]
In the display filter of the present invention, the electromagnetic wave shielding functional layer that can be added to the near-infrared ultraviolet absorbing layer or the laminate thereof shields electromagnetic waves generated from an electrical or electronic device, particularly a plasma display. As the electromagnetic wave shielding layer, a metal mesh layer and a transparent conductive thin film layer are used, and a metal mesh having high electromagnetic wave shielding properties is preferable. Since the metal mesh layer is formed by laminating a metal foil on a transparent substrate and forming a mesh by etching, an adhesive layer is usually interposed between the transparent substrate and the metal mesh. Adhesive layer is acrylic resin, polyester resin, polyurethane resin, polyvinyl alcohol alone or a saponified product thereof, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, polyimide resin, epoxy resin, polyurethane ester It is composed of an adhesive such as resin. The metal mesh layer is not particularly limited as long as it has an electromagnetic wave shielding function. For example, copper, iron, nickel, chromium, aluminum, gold, silver, stainless steel, tungsten, chromium, Titanium or the like can be used, and copper is particularly preferable. Examples of the copper foil include rolled copper foil and electrolytic copper foil, and the electrolytic copper foil is particularly preferable. By selecting the electrolytic copper foil, it is possible to achieve a good uniformity with a thickness of 10 μm or less, and good adhesion to chromium oxide etc. when blackened. Because you can.

  Here, in this invention, it is preferable that the one side or both surfaces of the said metal mesh are blackened. The blackening treatment is a treatment for blackening the surface of the metal mesh with chromium oxide or the like. When applied to the near-infrared ultraviolet absorbing layer or a laminate thereof, this oxidation-treated surface is usually a surface on the observer side. It arrange | positions so that it may become. Since the external light on the surface of the metal mesh layer is absorbed by chromium oxide or the like formed on the surface of the metal mesh layer by the blackening treatment, it is possible to prevent light from being scattered on the surface of the metal mesh layer.

The aperture ratio of the metal mesh layer is preferably as low as possible from the viewpoint of electromagnetic wave shielding ability. However, since the light transmittance decreases as the aperture ratio decreases, the aperture ratio is preferably 50% or more.
Moreover, since the opening part and non-opening part of a metal mesh layer are uneven | corrugated, the planarization layer in which binder resin was formed in the thickness more than the thickness of a metal mesh layer is laminated | stacked on the metal mesh layer. Also good.

[Anti-reflective function layer]
In the display filter of the present invention, the antireflection functional layer that can be added to the near-infrared ultraviolet absorbing layer or a laminate thereof is typically a laminate formed by combining a high refractive index layer and a low refractive index layer. If it has an antireflection function, it may have a layer structure other than this. The high refractive index layer is, for example, a thin film of ZnO or TiO ₂ material, or a transparent binder resin film in which fine particles of these materials are dispersed. The low refractive index layer is a thin film made of SiO ₂ , a SiO ₂ gel film, or a binder resin film having transparency containing fluorine or fluorine and silicon. When an antireflection layer is laminated on the display filter of the present invention, it is possible to reduce reflection of unnecessary light such as outside light on the laminated side, and to increase the contrast of the image or video of the applied display. it can.

[Anti-glare functional layer]
In the display filter of the present invention, the anti-glare functional layer that can be added to the near-infrared ultraviolet absorbing layer or the laminate thereof is, for example, beads such as polystyrene resin or acrylic resin having a diameter of about several μm in a binder resin having transparency. Can be mentioned. This is for preventing scintillation occurring at a specific position and direction of the display when it is arranged on the front surface of the display due to the light spreading property of the layer.

[Contamination prevention function layer]
In the display filter of the present invention, the antifouling functional layer that can be added to the display filter is used when the near-infrared ultraviolet absorbing layer or the laminate thereof is used, and the surface thereof is inadvertently contacted or contaminated from the environment. Therefore, it is a layer formed to prevent dust and contaminants from adhering to it, or to make it easy to remove even if it adheres. For example, a fluorine-based coating resin, a silicon-based coating agent, a silicon / fluorine-based coating agent, or the like is used, and among them, a silicon-fluorine-based coating agent is preferably applied. The thickness of these antifouling layers is preferably 100 nm or less, more preferably 10 nm or less, and even more preferably 5 nm or less. When the thickness of these antifouling layers exceeds 100 nm, the initial value of antifouling properties is excellent, but the durability is inferior. 5 nm or less is the most preferable from the balance of antifouling property and its durability.

[Neon light absorption functional layer]
In the display filter of the present invention, the neon light absorbing functional layer that can be added to the near-infrared ultraviolet absorbing layer or the laminate thereof is emitted from the plasma display panel when the display filter according to the present invention is used for a plasma display. Installed to absorb neon light. The neon light absorption region has a wavelength of 550 to 640 nm, and is preferably designed so that the light transmittance at a wavelength of 550 nm is 50% or less.
The neon light absorption functional layer can be formed in the same manner as the above-described near infrared ultraviolet absorption layer by dispersing a dye conventionally used as a dye having an absorption maximum in a wavelength region of at least 550 to 640 nm in a binder resin. it can. Specific examples of the dye include cyanine, oxonol, methine, subphthalocyanine or porphyrin.

The display filter of the present invention obtained as described above preferably has a haze value of 6%, more preferably 3% or less from the viewpoint of transparency.
Moreover, it is preferable from the point of a near-infrared absorption function that the maximum value of the light transmittance in a near-infrared area | region, ie, 800 nm-1100 nm, is 20% or less, and also 15% or less.

The display filter of the present invention preferably has a light transmittance of 10% or less, and more preferably 7% or less, in the entire wavelength region of less than 380 nm.
When the light transmittance is within the above range, ultraviolet rays contained in electrical or electronic devices, natural light, and the like can be blocked or controlled. As a result, it is possible to suppress deterioration of the near-infrared absorber due to ultraviolet rays, and it is possible to obtain a display filter whose light absorption function and initial color are stable for a long time. Further, it is possible to further improve the durability of various resin materials and other constituent materials (for example, a binder resin material and a near-infrared absorber) that constitute the display.

The display filter of the present invention is evaluated for light resistance as follows.
Before and after the display filter was irradiated with ultraviolet rays at 255 W / m ² , 43 ° C. for 100 hours using a sunshine weatherometer (for example, model S80 manufactured by Suga Test Instruments Co., Ltd.) using a sunshine carbon arc as a light source. Then, the maximum value of the difference between the haze value difference and the light transmittance value at 800 to 1100 nm is obtained.
The haze value can be measured according to JIS K7105. The light transmittance can be measured using a spectrophotometer, for example (manufactured by Shimadzu Corporation, product number: “UV-3100PC”).
The display filter of the present invention has a difference in haze value of 3% or less and a maximum value of difference in light transmittance value of 3% or less, excellent environmental stability, and a near-infrared absorber by ultraviolet irradiation. The haze increase due to deterioration or bleeding out of the ultraviolet absorber is suppressed. The difference in haze value is further 2% or less, particularly 1% or less, and the difference in light transmittance is further 2% or less, particularly preferably 1% or less.

The display according to the present invention is characterized in that the display filter is arranged on a display surface of the display.
Examples of the display of the present invention include electronic displays such as CRT (CRT), LCD (Liquid Crystal Display), PDP (Plasma Display), organic / inorganic EL display, and FED (Field Emission Display), which are display panels of various electronic devices. Is mentioned.

  As shown in FIG. 2, when the display filter 11 according to the present invention is used in the display 7 of the present invention, the display is designed to cut undesired light rays such as near infrared rays emitted from the display panel 6 or electromagnetic waves. It is installed in front of the panel display surface 8.

The test methods performed in the examples described later are as follows.
(1) Light transmittance The light transmittance of the obtained display filter was measured using a spectrophotometer (manufactured by Shimadzu Corporation, product number: “UV-3100PC”).
(2) Haze The haze of the obtained display filter was measured according to JIS K7105.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. These descriptions do not limit the present invention. In the examples, parts represent parts by weight unless otherwise specified.
In the following examples, the obtained display filter was irradiated with ultraviolet rays at 255 W / m ² , 43 ° C. for 100 hours from the PET film side using a sunshine weatherometer (manufactured by Suga Test Instruments Co., Ltd.). The wavelength at which the difference in the value of light transmittance shows the maximum value in the range of 800 to 1100 nm was 1080 nm.

<Example 1>
An acrylic resin obtained by dissolving an acrylic resin (trade name: BR-80, manufactured by Mitsubishi Rayon Co., Ltd.) in methyl ethyl ketone / toluene (solvent blending ratio = 1: 1) so that the solid content ratio is 20% (mass basis). In 19.6 g of the solution, 0.25 g of diimmonium-based near infrared absorber (trade name: CIR1085, manufactured by Nippon Carlit Co., Ltd.) and benzotriazole-based ultraviolet absorber (trade name: TINUVIN 928, manufactured by Ciba Specialty Chemicals Co., Ltd.) , Molecular weight: 441.6) Using a coating solution obtained by adding 0.2 g and dispersing sufficiently, a commercially available polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., trade name: Cosmo Shine A4300), Apply to the top with a Meyer bar so that the dry film thickness is 5 μm, and hit with dry air with a wind speed of 5 m / sec. And dried for 1 minute at 100 ° C. to form a near infrared ultraviolet absorbing layer in Bun to obtain a near infrared ultraviolet absorbing function with a filter for a display.
The obtained display filter had a light transmittance at 1080 nm of 5.2% and a haze of 0.8%. The display filter was irradiated with ultraviolet rays from the PET film side using a sunshine weatherometer at 255 W / m ² at 43 ° C. for 100 hours. The light transmittance at 1080 nm was 6.3% and the haze was 0.3. It was 8%.
The difference in light transmittance at 1080 nm, which was the maximum value of the difference in light transmittance at 800 to 1100 nm before and after irradiation for 100 hours, was 1.1%, and the difference in haze value was 0%.

<Example 2>
A filter for display was carried out in the same manner as in Example 1 except that 0.15 g of a phthalocyanine-based near infrared absorber (manufactured by Nippon Shokubai Co., Ltd., trade name: IR-1) was further added as a near infrared absorber. Got.
The obtained display filter had a light transmittance of 4.8% at 1080 nm and a haze of 0.8%. The display filter was irradiated with ultraviolet rays at 255 W / m ² at 43 ° C. for 100 hours from the PET film side using a sunshine weatherometer. The light transmittance at 1080 nm was 6.1% and the haze was 0.00. It was 9%.
The difference in light transmittance value at 1080 nm, which was the maximum difference in light transmittance values at 800 to 1100 nm before and after irradiation for 100 hours, was 1.3%, and the difference in haze value was 0.1%. It was.

<Example 3>
The same procedure as in Example 1 was performed except that 0.2 g of a hydroxyphenyltriazine ultraviolet absorber (Ciba Specialty Chemicals, trade name: TINUVIN400, molecular weight: 647) was used as the ultraviolet absorber. A display filter was obtained.
The obtained display filter had a light transmittance at 1080 nm of 5.1% and a haze of 0.8%. When the above-mentioned display filter was irradiated with ultraviolet rays at 255 W / m ² at 43 ° C. for 100 hours from the PET film side using a sunshine weatherometer, the light transmittance at 1080 nm was 6.4%, and the haze was 0.9%. Met.
The difference in light transmittance value at 1080 nm, which was the maximum difference in light transmittance values at 800 to 1100 nm before and after irradiation for 100 hours, was 1.3%, and the difference in haze value was 0.1%. It was.

<Example 4>
A display filter was obtained in the same manner as in Example 3 except that the blending amount of the ultraviolet absorber was 1.5 g.
The obtained display filter had a light transmittance of 5.4% at 1080 nm and a haze of 0.9%. When the above-mentioned display filter was irradiated with UV light at 255 W / m ² at 43 ° C. for 100 hours from the PET film side with a sunshine weatherometer, the light transmittance at 1080 nm was 6.1% and the haze was 1.3%. there were.
The difference in light transmittance value at 1080 nm, which was the maximum difference in light transmittance values at 800 to 1100 nm before and after irradiation for 100 hours, was 0.7%, and the difference in haze value was 0.4%. It was.

<Example 5>
The same procedure as in Example 1 was performed except that 0.4 g of an ultraviolet absorbing resin having a benzotriazole skeleton (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: UVA1050S, molecular weight: 400,000) was used as the ultraviolet absorber. A display filter was obtained.
The obtained display filter had a light transmittance at 1080 nm of 5.1% and a haze of 0.9%. When the above-mentioned display filter was irradiated with ultraviolet rays at 255 W / m ² at 43 ° C. for 100 hours from the PET film side using a sunshine weatherometer, the light transmittance at 1080 nm was 6.4% and the haze was 1.0%. Met.
The difference in light transmittance value at 1080 nm, which was the maximum difference in light transmittance values at 800 to 1100 nm before and after irradiation for 100 hours, was 1.3%, and the difference in haze value was 0.1%. It was.

<Example 6>
As in Example 1 except that 0.4 g of a hindered amine light stabilizer (manufactured by Ciba Specialty Chemicals, trade name: TINUVIN292, molecular weight: 508.8) was further added as a light stabilizer. This was carried out to obtain a display filter.
The obtained display filter had a light transmittance at 1080 nm of 5.5% and a haze of 0.9%. When the display filter was irradiated with ultraviolet rays at 255 W / m ² at 43 ° C. for 100 hours from the PET film side using a sunshine weatherometer, the light transmittance at 1080 nm was 5.7% and the haze was 1.0%. Met.
The difference in light transmittance value at 1080 nm, which was the maximum difference in light transmittance values at 800 to 1100 nm before and after irradiation for 100 hours, was 0.2%, and the difference in haze value was 0.1%. It was.

<Example 7>
The same procedure as in Example 5 was performed except that 0.4 g of a hindered amine light stabilizer (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: HAL11025S, molecular weight: 400,000) was further added as a light stabilizer. A display filter was obtained.
The obtained display filter had a light transmittance of 5.7% at 1080 nm and a haze of 1.0%.
When the above-mentioned display filter was irradiated with ultraviolet rays at 255 W / m ² at 43 ° C. for 100 hours from the PET film side using a sunshine weatherometer, the light transmittance at 1080 nm was 6.1% and the haze was 1.0%. Met.
The difference in light transmittance value at 1080 nm, which was the maximum difference in light transmittance values at 800 to 1100 nm before and after irradiation for 100 hours, was 0.4%, and the difference in haze value was 0%.

<Comparative Example 1>
A display filter was obtained in the same manner as in Example 1 except that no ultraviolet absorber was used.
The obtained display filter had a light transmittance at 1080 nm of 5.5% and a haze of 0.9%. When the above-mentioned display filter was irradiated with UV light at 255 W / m ² at 43 ° C. for 100 hours from the PET film side using a sunshine weatherometer, the light transmittance at 1080 nm was 46.1%, and the haze was 1.0%. Met.
The difference in light transmittance value at 1080 nm, which was the maximum value of the light transmittance value at 800 to 1100 nm before and after 100 hours irradiation, was 40.6%, and the difference in haze value was 0.1%. It was.

<Comparative example 2>
The same procedure as in Example 1 was performed except that 0.2 g of a benzotriazole-based ultraviolet absorber (manufactured by Ciba Specialty Chemicals, trade name: TINUVIN327, molecular weight: 357.9) was used as the ultraviolet absorber. A display filter was obtained.
The obtained display filter had a light transmittance of 5.6% at 1080 nm and a haze of 0.9%. When the above-mentioned display filter was irradiated with ultraviolet rays at 255 W / m ² at 43 ° C. for 100 hours from the PET film side using a sunshine weatherometer, the light transmittance at 1080 nm was 5.9%, and the haze was 4.5%. Met.
The difference in light transmittance value at 1080 nm, which was the maximum difference in light transmittance values at 800 to 1100 nm before and after irradiation for 100 hours, was 0.3%, and the difference in haze value was 3.6%. It was.

<Summary of results>
The maximum difference in the light transmittance values at 800 to 1100 nm and the difference in the haze values before and after the display filters obtained in Examples 1 to 7 were irradiated with ultraviolet rays at 43 ° C. for 100 hours are the present invention. The near-infrared absorption ability and transparency before ultraviolet irradiation were maintained even after ultraviolet irradiation.
On the other hand, the display filter obtained in Comparative Example 1 that did not use an ultraviolet absorber maintained transparency before and after ultraviolet irradiation, but a decrease in near-infrared absorption ability was observed.
Further, the display filter obtained in Comparative Example 2 using a system ultraviolet absorber having a small molecular weight maintained the near infrared absorption ability before and after the ultraviolet irradiation, but the difference in haze value was larger than 3%. A decrease in transparency was observed. It is presumed to be mainly due to the bleeding out of the ultraviolet absorber.

It is a schematic sectional drawing which shows an example of the filter for displays of this invention. It is a schematic sectional drawing which shows an example of the display formed by arrange | positioning the display filter of this invention, and this display filter on the display surface. It is a schematic sectional drawing which shows an example of the filter for displays of this invention. It is a schematic sectional drawing which shows an example of the filter for displays of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display filter 2 Transparent base material 3 Near-infrared ultraviolet absorption layer 4 Laminated body 5 Functional layer 6 Display panel 7 Display 8 Display panel display surface 11 Display filter

Claims (8)

A display filter comprising a near-infrared ultraviolet absorbing layer containing at least a near-infrared absorber and an ultraviolet absorber in the same layer, wherein the display filter is irradiated with UV of 255 W / m ² at 43 ° C. for 100 hours. A display filter, wherein a difference in haze value between before and after is 3% or less and a maximum value of a difference in light transmittance at 800 to 1100 nm is 3% or less.   2. The display filter according to claim 1, wherein the light transmittance is 10% or less in all wavelength regions of less than 380 nm.   The display filter according to claim 1 or 2, wherein the ultraviolet absorber has a molecular weight of 400 or more.   The display filter according to any one of claims 1 to 3, wherein the ultraviolet absorbent has a molecular weight of 10,000 or more.   The display filter according to any one of claims 1 to 4, wherein the near-infrared ultraviolet absorbing layer further contains a light stabilizer having a molecular weight of 300 or more.   6. The display filter according to claim 5, wherein the light stabilizer has a molecular weight of 10,000 or more.   The display filter according to any one of claims 1 to 6, wherein any one or two of a color tone adjustment function, an electromagnetic wave shielding function, an antireflection function, an antiglare function, an antifouling function, and a neon light absorbing function. A display filter comprising a single layer or two or more layers having a function of more than one kind.   8. A display comprising the display filter according to claim 1 disposed on a display surface of the display.

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