JP2006154516A - Near ir beams absorption filter for plasma display panels, and plasma display panel using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a near IR absorption filter for PDP which is high in near IR absorptive power, is excellent in durability and can be inexpensively produced. <P>SOLUTION: Tungsten oxide particulates are produced by dissolving tungsten hexachloride by a slight amount each into ethanol to obtain a solution and drying the solution to a powder form, then heating the powder in a reducing atmosphere and heating the powder in an argon atmosphere after once restoring the powder to room temperature. The tungsten oxide particulates are dispersed into a UV curing resin and are allowed to cure after coating application onto a suitable substrate, and thereby, the near IR absorption filter for PDP which is high in visible light transmittance and the near IR absorptive power, is excellent in the durability and can be inexpensively produced is obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical filter for a plasma display panel (hereinafter also referred to as PDP), and in particular, a near-PDP for absorbing near-infrared rays emitted from a light emitting portion of a PDP main body toward the front surface of the PDP screen. The present invention relates to an infrared absorption filter and a PDP using the filter.

  In recent years, PDPs have attracted attention as displays become larger and thinner. A general configuration of this PDP will be described with reference to the drawings. FIG. 1 is an enlarged cross-sectional view showing an outline of a light emitting portion of an AC type (AC type) PDP. In FIG. 1, reference numeral 11 denotes a front glass substrate (front cover plate), and display electrodes 12 are formed on the front glass substrate 11. Further, the front glass substrate 11 on which the display electrodes 12 are formed is covered with a dielectric glass layer 13 and a protective layer 14 made of magnesium oxide (MgO) (see, for example, Patent Document 1). Reference numeral 15 denotes a rear glass substrate (back plate). On the rear glass substrate 15, address electrodes 16, partition walls 17, and a phosphor layer 18 are provided. Reference numeral 19 encloses a discharge gas. It is a discharge space.

  The light emission principle of the PDP is that a voltage is applied between the display electrode 12 and the address electrode 16 to cause discharge in the discharge space 19 and excite the mixed gas of xenon and neon introduced into the discharge space. A vacuum ultraviolet ray is emitted, and the phosphor layer 18 that emits red, green, and blue fluorescence is caused to emit light by the vacuum ultraviolet ray, thereby enabling color display.

  However, xenon gas also generates near infrared rays in addition to the vacuum ultraviolet rays, and a part of the near infrared rays is emitted forward of the PDP. In particular, near-infrared rays having a wavelength range of 800 nm to 1100 nm cause problems such as malfunctioning of cordless phones and remote controls of home appliances, and adverse effects on transmission optical communication. For this reason, the near-infrared shielding process is performed on the front surface of the PDP for the purpose of preventing the malfunction and the like.

  These near-infrared shielding processes are performed by providing a near-infrared absorber as a filter on the front surface of the PDP. The near-infrared absorber has a visible light region (wavelength region, wavelength region, so as not to adversely affect the luminance of the PDP). Light with a wavelength of about 380 nm to 780 nm) is sufficiently transmitted, and near infrared rays with a wavelength range of 800 nm to 1100 nm are required to be shielded. Conventionally, as a PDP filter that absorbs near-infrared rays, filters or the like in which multiple types of organic dyes and metal complexes are used in combination or in multiple layers (see Patent Document 2, Patent Document 3, etc.) have been proposed.

  When an organic compound or a metal complex is used as a filter, a method of coating a base material on the surface of the PDP with a solution obtained by dissolving the organic compound or the metal complex in a solvent is generally used. Here, as a near-infrared absorber such as organic compounds and metal complexes, diimonium compounds, aminium compounds, phthalocyanine compounds, organometallic complexes, cyanine compounds, azo compounds, polymethine compounds, quinone compounds, diphenylmethane compounds Compounds, triphenylmethane compounds, etc., but these have low resistance to heat and light and are likely to deteriorate over time, so when these organic compounds and metal complexes are used alone, long-term performance is achieved. There was a problem that it was difficult to hold.

  Therefore, in order to effectively block near infrared rays using organic compounds and metal complexes, it is necessary to coexist two or more substances, but this time, each substance reacts and the characteristics deteriorate, The metal complex has a problem of poor solubility in a solvent and does not sufficiently dissolve. Therefore, when each single solution is prepared in consideration of the solubility of each near-infrared absorber, there is a problem that it takes time since it is necessary to recoat each solution.

JP-A-5-342991 JP 2001-228324 A JP 2001-133624 A

  The present invention has been made paying attention to such problems, and the problem is that the near-infrared absorbing filter for PDP, which has a large near-infrared absorbing power, has excellent durability, and can be manufactured at low cost, and the filter. It is to provide a PDP using the.

  In order to solve the above-mentioned problems, the present inventor conducted intensive research focusing on inorganic materials that absorb near infrared rays from the viewpoint of improving the weather resistance of the near infrared absorption filter for PDP. By using tungsten oxide having an average dispersed particle diameter of 800 nm or less and / or composite tungsten oxide fine particles as inorganic material fine particles having good weather resistance capable of shielding near infrared rays, a wavelength of 380 nm to 780 nm can be obtained. It is possible to obtain a near-infrared absorption filter for PDP in which the maximum value of light transmittance in the visible region is 50% or more and the minimum value of light transmittance in the near-infrared region of wavelengths from 800 nm to 1100 nm is 30% or less. I found it. By using the inorganic material fine particles, a near-infrared absorption filter for PDP that has a large near-infrared absorptivity and excellent durability and can be produced at low cost has been developed.

That is, the first invention of the present invention,
A plasma display panel having a base material and a resin or metal oxide film provided on the surface of the base material, wherein particles of a near-infrared absorbing material are dispersed in the base material and / or in the film Near-infrared absorbing material filter for
The near-infrared absorbing material particles include tungsten oxide fine particles and / or composite tungsten oxide fine particles having an average dispersed particle size of 800 nm or less,
A near-infrared absorbing material filter for a plasma display panel, wherein the maximum value of visible light transmittance at a wavelength of 380 nm to 780 nm is 50% or more and the minimum value of near-infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less I will provide a.

The second invention of the present invention is:
A near-infrared absorbing material filter for a plasma display panel in which a sheet-like or film-like resin is sandwiched between base materials and particles of the near-infrared absorbing material are dispersed in the resin or / and the base material,
The near-infrared absorbing material particles include tungsten oxide fine particles and / or composite tungsten oxide fine particles having an average dispersed particle size of 800 nm or less,
A near-infrared absorbing material filter for a plasma display panel, wherein the maximum value of visible light transmittance at a wavelength of 380 nm to 780 nm is 50% or more and the minimum value of near-infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less I will provide a.

The third invention of the present invention is:
The resin or coating is a laminate of two or more layers having different refractive indexes, and has a structure that exhibits an antireflection function due to a difference in refractive index between the laminates, and at least one of the laminates The near-infrared absorption for a plasma display panel according to the first or second invention, wherein tungsten oxide fine particles and / or composite tungsten oxide fine particles having an average dispersed particle diameter of 800 nm or less are dispersed in the layer. Provide a filter.

The fourth invention of the present invention is:
The near-infrared absorbing material further comprises a diimonium compound, an aminium compound, a phthalocyanine compound, an organometallic complex, a cyanine compound, an azo compound, a polymethine compound, a quinone compound, a diphenylmethane compound, or a triphenylmethane compound. A near-infrared absorption filter for a plasma display panel according to any one of the first to third inventions, comprising one or more selected organic compounds.

The fifth invention of the present invention is:
The tungsten oxide fine particles are tungsten oxide fine particles represented by a general formula WyOz (W is tungsten, O is oxygen, 2.2 ≦ z / y ≦ 2.999). A near-infrared absorption filter for a plasma display panel according to any one of the first to third aspects is provided.

The sixth invention of the present invention is:
The composite tungsten oxide fine particles have the general formula MxWyOz (where the M element is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir). Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti , Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, one or more elements, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1. 1. Near-infrared absorption for plasma display panel according to any one of the first to third inventions, characterized in that the composite tungsten oxide fine particles are represented by the following formula: 1, 2.2 ≦ z / y ≦ 3.0) Provide a filter.

The seventh invention of the present invention is
The tungsten oxide fine particles or / and the composite tungsten oxide fine particles are composed of a magnetic phase having a composition ratio represented by the general formula WyOz (W is tungsten, O is oxygen, 2.45 ≦ z / y ≦ 2.999). The near-infrared absorption filter for plasma display panels according to any one of the first to third inventions is provided.

The eighth invention of the present invention is:
The composite tungsten oxide fine particles include one or more kinds of crystal structures of hexagonal crystal, tetragonal crystal, and cubic crystal.

The ninth invention of the present invention is:
M element of the composite tungsten oxide fine particles is one or more elements selected from Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn, and the composite tungsten oxide fine particles Has a hexagonal crystal structure. The near-infrared absorption filter for plasma display panels according to the eighth invention is provided.

The tenth aspect of the present invention is:
The surface of the tungsten oxide fine particles or / and the composite tungsten oxide fine particles is coated with an oxide containing one or more elements selected from Si, Ti, Zr, and Al. A near-infrared absorption filter for a plasma display panel according to any one of the ninth to ninth aspects is provided.

The eleventh aspect of the present invention is
The near-infrared ray for a plasma display panel according to any one of the first to third inventions, wherein the substrate is composed of one or more types of substrates selected from a plastic board, a plastic film, and glass. Provide an absorption filter.

The twelfth aspect of the present invention is
The base material is selected from polyolefin resin, polyester resin, polycarbonate resin, poly (meth) acrylate resin, polystyrene, polyvinyl chloride, polyvinyl acetate, polyarylate resin, and polyethersulfone resin. The near-infrared absorption filter for a plasma display panel according to claim 11, wherein the near-infrared absorption filter is a plastic board or plastic film containing one or more kinds of resins.

The thirteenth aspect of the present invention is
The coating film has one or more components selected from an ultraviolet curable resin, a thermoplastic resin, a thermosetting resin, a room temperature curable resin, a metal alkoxide, a hydrolysis polymer of a metal alkoxide, and an adhesive material. A near-infrared absorption filter for a plasma display panel according to any one of the first to third aspects is provided.

The fourteenth invention of the present invention is
The sheet-like or film-like resin is polyvinyl butyral. The near-infrared absorption filter for a plasma display panel according to the second invention is provided.

The fifteenth aspect of the present invention is
A near-infrared absorption filter for a plasma display panel according to any one of the first to third inventions, further comprising a color tone adjusting component.

The sixteenth invention of the present invention is
A near-infrared absorption filter for a plasma display panel according to any one of the first to fifteenth inventions is provided.

  The near-infrared absorption filter for PDP according to the first or second invention includes tungsten oxide fine particles and / or composite tungsten oxide fine particles having an average dispersed particle size of 800 nm or less, and thus has heat resistance and weather resistance. Therefore, it can be dispersed in a variety of resins and metal oxides, and a variety of curing methods can be employed. Therefore, it has excellent durability and high productivity, and can be manufactured at low cost. Furthermore, since the maximum value of visible light transmittance at a wavelength of 380 nm to 780 nm is 50% or more, the near infrared transmittance at a wavelength of 800 nm to 1100 nm is as large as 30% or less, and the near infrared absorptivity is large. Without lowering, it was possible to avoid a situation in which a surrounding electronic device malfunctioned due to near infrared rays generated from the PDP main body.

  The near-infrared absorption filter for PDP according to the third invention is a PDP that exhibits an antireflection function by forming a layer in which two or more layers of tungsten oxide fine particles and / or composite tungsten oxide fine particles are dispersed. By using the high refractive index layer in the front panel, the near-infrared absorption effect and the antireflection effect can be exhibited simultaneously, thereby improving the optical characteristics and reducing the production cost.

  The near-infrared absorption filter for PDP according to the fourth aspect of the invention uses a tungsten oxide fine particle or / and a composite tungsten oxide fine particle in combination with an organic compound such as a diimonium compound or an organometallic complex, whereby the organic compound is Compensating for the weakness of being inferior in heat resistance, weather resistance, etc., it was possible to exhibit the advantages of each other in inorganic and organic near infrared absorbing materials.

  The near-infrared absorption filters for PDPs according to the fifth to tenth inventions all exhibited excellent optical characteristics and durability.

  Since the near-infrared absorption filter for PDP according to the 11th to 12th or 14th invention exhibits excellent optical characteristics, durability and mechanical characteristics, it has become a near-infrared absorption filter for PDP according to various embodiments.

  The near-infrared absorption filter for PDP according to the thirteenth invention exhibits excellent optical properties, durability, and mechanical diversity, so that it becomes a near-infrared absorption filter for PDP according to various aspects.

  The near-infrared absorption filter for PDP according to the fifteenth aspect of the invention can contribute to improving the contrast of the PDP main body in addition to excellent optical characteristics and durability.

  The PDP according to the sixteenth aspect of the present invention can prevent the surrounding electronic devices from malfunctioning due to near infrared rays generated from the main body.

Hereinafter, embodiments of the present invention will be described in detail.
The near-infrared absorption filter for PDP according to the present invention has a base material and a resin or transparent metal oxide material film formed on the surface of the base material, in the base material and / or in the film. A near-infrared absorbing filter for PDP in which particles of near-infrared absorbing material are dispersed, wherein the near-infrared absorbing material includes tungsten oxide fine particles and / or composite tungsten oxide fine particles having an average dispersed particle diameter of 800 nm or less. The maximum value of the light transmittance in the visible light region having a wavelength of 380 nm to 780 nm is 50% or more, and the minimum value of the light transmittance in the near infrared light region having a wavelength of 800 nm to 1100 nm is 30% or less.

  According to the test results of the present inventors, if the minimum value of the near-infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less, it is avoided that the surrounding electronic equipment malfunctions due to the near-infrared light generated from the PDP main body. It has been found that it can be done. On the other hand, if the maximum value of the visible light transmittance in the wavelength region of 380 nm to 780 nm is 50% or more, it is preferable that the luminance of the PDP main body can be avoided and the image is not darkened. Therefore, in the near infrared filter for PDP, when the maximum value of the visible light transmittance in the wavelength range of 380 nm to 780 nm is required to be 50% or more, and the minimum value of the near infrared transmittance of the wavelength 800 nm to 1100 nm is required to be 30% or less. Conceivable.

  Further, as a preferred modification of the near infrared absorption filter for PDP, the coating film is a multilayer laminate of two or more layers, and the refractive index of the multilayer laminate is made different so that the refractive index at the boundary surface of the multilayer laminate is different. It has a structure that exhibits an antireflection function due to a difference in rate, and tungsten oxide fine particles and / or composite tungsten oxide fine particles having an average dispersed particle size of 800 nm or less are dispersed in at least one layer of the multilayer laminate. This is a near-infrared absorption filter for plasma display panels.

  As another preferred modification of the near-infrared absorption filter for PDP, the sheet-like or film-like resin is sandwiched between transparent substrates, and the tungsten oxide or There is a near infrared absorption filter for PDP in which fine particles of composite tungsten oxide are dispersed. It is composed of fine particles having an average dispersed particle diameter of 800 nm or less, the maximum value of light transmittance in the visible light region with a wavelength of 380 nm to 780 nm is 50% or more, and the light in the near infrared light region with a wavelength of 800 nm to 1100 nm The minimum value of the transmittance is 30% or less.

The near-infrared absorbing material according to the present invention includes tungsten oxide fine particles and / or composite tungsten oxide having an average dispersed particle diameter of 800 nm or less.
First, the fine particles of tungsten oxide applied to the present invention are represented by the general formula WO _X (W is tungsten, O is oxygen, 2.45 ≦ X ≦ 2.999). The tungsten oxide fine particles function effectively as a near-infrared absorbing component.

Here, examples of the tungsten oxide fine particles represented by the general formula WO _X (2.45 ≦ X ≦ 2.999) include W ₁₈ O ₄₉ , W ₂₀ O ₅₈ , and W ₄ O ₁₁ . If the value of X is 2.45 or more, it is possible to completely avoid the appearance of an undesired WO ₂ crystal phase in the heat ray absorbing material and to obtain the chemical stability of the material. I can do it. On the other hand, if the value of X is 2.999 or less, a sufficient amount of free electrons is generated, and an efficient near-infrared absorbing material is obtained. A WO _X compound having an X range of 2.45 ≦ X ≦ 2.95 is a compound called a so-called Magneli phase and has excellent durability.

Next, the general formula M _Y WO _Z (wherein M element is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, One or more elements selected from Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, and I, W is tungsten, O is oxygen, 0.001 ≦ Y ≦ 1.0, 2 The composite tungsten oxide fine particles represented by .2 ≦ Z ≦ 3.0) function effectively as a near-infrared absorbing component.

  The composite tungsten oxide fine particles represented by the general formula MxWyOz are selected from the hexagonal, tetragonal, and cubic crystals because they have excellent durability when they have a hexagonal, tetragonal, or cubic crystal structure. Preferably it contains one or more crystal structures. For example, in the case of composite tungsten oxide fine particles having a hexagonal crystal structure, preferable M elements include Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn. Examples thereof include composite tungsten oxide fine particles containing one or more selected elements.

At this time, the addition amount Y of the added M element is preferably 0.001 or more and 1.0 or less, and more preferably around 0.33. This is because the Y value theoretically calculated from the hexagonal crystal structure is 0.33, and preferable optical characteristics can be obtained with the addition amount before and after this value. On the other hand, the abundance Z of oxygen is preferably 2.2 or more and 3.0 or less. Typical examples include Cs _0.33 WO ₃ , Rb _0.33 WO ₃ , K _0.33 WO ₃ , Ba _0.33 WO _{3 and the} like, but Y and Z fall within the above ranges. If it is a thing, a useful near-infrared absorption characteristic can be acquired.

The tungsten oxide fine particles and the composite tungsten oxide fine particles described above may be used alone or in combination.
Further, if the surfaces of the tungsten oxide fine particles and / or composite tungsten oxide fine particles are covered with an oxide containing one or more elements of Si, Ti, Zr, and Al, the weather resistance is further improved. Can be preferred.

  Since the near-infrared absorbing filter having a coating film in which the near-infrared absorbing material is dispersed is a near-infrared absorbing filter for PDP, the near-infrared absorbing material can efficiently absorb near-infrared while maintaining transparency. Is required. Here, the near-infrared absorbing component containing the tungsten oxide fine particles and / or composite tungsten oxide fine particles according to the present invention greatly absorbs light in the near-infrared region, particularly in the vicinity of a wavelength of 900 to 2200 nm. There are many things that turn from blue to green.

On the other hand, the tungsten oxide fine particles and / or composite tungsten oxide fine particles, which are the near-infrared absorbing material, are contained in the base material, in the film containing a resin or metal oxide formed on the base material, or both Although the dispersed, its content, when expressed in content per unit area is preferably between ^{0.01g / m 2 ~10g / m 2} . If the content is more than 0.01 g / m ² , a sufficient near-infrared absorption effect appears, and if it is 10 g / m ² or less, a sufficient amount of visible light can be transmitted.

  When the tungsten oxide fine particles or / and the composite tungsten oxide fine particles are applied as a near-infrared absorbing material, the transmittance in the visible light region at a wavelength of 380 nm to 780 nm is high, and the transmittance in the near infrared region at a wavelength of 780 nm to 1500 nm. Lower. The decrease in transmittance at the wavelength of 780 nm to 1500 nm is considered to be caused by absorption reflection caused by plasmon resonance due to conduction electrons in the tungsten oxide or composite tungsten oxide. Further, in the visible light region in the wavelength range of 380 nm to 780 nm, the amount of absorption is small compared to the absorption in the vicinity of the wavelength of 1000 nm, and thus visibility is maintained well. As a result, even if a near-infrared absorbing filter having a film in which the near-infrared absorbing material is dispersed is installed on the front surface of the display, the screen display can be confirmed sufficiently clearly, which is preferable.

  When the tungsten oxide and / or composite tungsten oxide is used as a near-infrared absorber, it is preferable to use a fine particle dispersion method as an industrially inexpensive and simple method. This is a method in which the tungsten oxide fine particles or the composite tungsten oxide fine particles are uniformly dispersed in a filter base material or a resin or coating provided on the filter base material, and a near infrared ray transmitted therethrough is shielded. It is.

  When producing a near-infrared absorption filter for a plasma display panel by the fine particle dispersion method, the particle diameter of the fine particles of the tungsten oxide and / or composite tungsten oxide needs to be 800 nm or less, preferably 200 nm or less, More preferably, it is 100 nm or less. When the particle diameter of tungsten oxide or composite tungsten oxide fine particles exceeds 800 nm, the light in the visible light region having a wavelength of 380 nm to 780 nm emitted from the PDP is scattered by geometrical scattering or Mie scattering. This is because it looks like frosted glass and a clear screen display cannot be obtained. When the particle diameter is 200 nm or less, the geometric scattering or Mie scattering is reduced, and a Rayleigh scattering region is obtained. In the Rayleigh scattering region, the scattered light is reduced in inverse proportion to the sixth power of the particle diameter, so that the visible light scattering is reduced and a clear screen display is possible. Further, it is more preferable that the particle diameter is 100 nm or less because scattered light is extremely reduced. On the other hand, if the particle diameter is 1 nm or more, industrial production is easy.

  Various methods such as a dry method and a wet method can be used to disperse the tungsten oxide and composite tungsten oxide fine particles, but the wet method is particularly effective when dispersing tungsten oxide and composite tungsten oxide of 200 nm or less. Specific examples include a ball mill, a sand mill, a medium stirring mill, and ultrasonic irradiation. Further, when dispersing the fine particles, it is easy to stably hold the tungsten oxide and composite tungsten oxide fine particles of 200 nm or less in the liquid by adding various dispersants or adjusting the pH. Various types of dispersants can be selected depending on the compatibility with the solvent and binder used, and typical examples include silane coupling agents and various surfactants.

Next, a method for producing a near-infrared absorbing filter for a plasma display panel according to the present invention using a dispersion of a near-infrared absorber in which fine particles are dispersed in a liquid medium will be specifically described below.
In the following description, a method for manufacturing a near-infrared absorption filter for a plasma display panel, in which tungsten oxide and composite tungsten oxide fine particles are dispersed in a filter base material, will be described as an example.

  First, a near-infrared absorbing material dispersion in which tungsten oxide fine particles and / or composite tungsten oxide fine particles exemplified in the examples described later are dispersed in a liquid medium is prepared, and the solvent component is removed from the dispersion. Thus, a powder of the fine particles is obtained. In addition, by dispersing the tungsten oxide fine particles and the composite tungsten oxide fine particles, which are raw materials, in the liquid medium, the fine particles bonded at the initial raw material stage are separated from each other to obtain a powder in which fine fine particles are dispersed. Is possible. However, when the particle diameter of the fine particles is miniaturized at the initial raw material stage, the treatment may be omitted.

  The powder of the tungsten oxide fine particles and / or the composite tungsten oxide fine particles can be kneaded as they are in the resin constituting the filter base material to produce a plastic board or a plastic film. Here, when the powder of the near-infrared absorbing material is kneaded into the resin, it is generally heated and mixed at a temperature near the melting point of the resin (around 200 to 300 ° C.). When an organic compound is used, the heat resistance of the organic compound is limited, and the kneading work is difficult. However, in the present invention, since the powder of inorganic oxide fine particles having high heat resistance is used, mixing at around 200 ° C. to 300 ° C., which is the melting point of a normal resin, is also possible.

  As described above, the resin mixed with the tungsten oxide fine particles and / or the composite tungsten oxide fine particles can be pelletized, and further formed into a plastic film by each method. For example, a transparent resin film can be formed by selecting a transparent resin and using a known T-die molding method, calendar molding method, compression forming method, casting method, or the like.

  About the thickness of a base material, although based on a use purpose, the film and board-shaped thing of the range of 10 micrometers-3 mm are desirable. At this time, the compounding amount of the tungsten oxide fine particles or / and the composite tungsten oxide fine particles with respect to the base resin can be arbitrarily set according to the thickness of the base material and required optical characteristics. Therefore, the blending amount is such that the optical characteristics of the obtained near-infrared absorption filter are such that the maximum value of the transmittance in the visible light region with a wavelength of 380 nm to 780 nm is 50% or more and the minimum value of the near-infrared transmittance with a wavelength of 800 nm to 1100 nm. May be appropriately set within a range of 30% or less.

Specific examples of the base resin include polyolefin resin, polyester resin, polycarbonate resin, poly (meth) acrylate ester resin, polystyrene, polyvinyl chloride, from the viewpoint of optical properties and mechanical properties. Polyvinyl acetate, polyarylate resin, polyethersulfone resin and the like can be mentioned. Among these resins, amorphous polyolefin resin, polyester resin, polycarbonate resin, poly (meth) acrylate resin, polyarylate resin, and polyethersulfone resin are preferable. Among amorphous polyolefin resins, Among the polyester-based resins, the cyclic polyolefin is more preferably polyethylene terephthalate. As the base material other than the resin, glass is preferable from the viewpoint of optical properties and mechanical properties.
Further, by selecting a polyvinyl butyral (PVB) resin as a base resin, and sandwiching a plastic sheet or plastic film in which near-infrared absorbing material particles are dispersed in the base resin with a transparent base material such as glass, The near-infrared absorbing filter for laminated glass is also a preferable configuration as a near-infrared absorbing filter for PDP.

Next, an example of a method for producing a near infrared absorption filter for PDP in which fine particles are dispersed in a film formed on a substrate will be described.
First, a near-infrared absorbing material dispersion in which tungsten oxide fine particles and / or composite tungsten oxide fine particles are dispersed in a liquid solvent is prepared, and this dispersion is applied to the surface of a substrate such as a plastic board, plastic film, or glass. Coat evenly. And if this liquid solvent is evaporated, the near-infrared absorption filter for PDP by which microparticles | fine-particles were disperse | distributed in the film formed on the base material can be obtained. In the filter, the near-infrared absorption efficiency can be adjusted by changing the film thickness of the coating. Furthermore, by adding an appropriate binder or the like to the dispersion of the near-infrared absorbing material, the binding property of the film to the substrate is improved, and the protection function on the filter surface is improved and the adhesion to the main body is improved. It is also a preferable configuration to provide functions.

  In addition, a multilayer laminated film having an antireflection function may be formed on the front panel surface of the PDP. The multilayer laminated coating is an antireflection coating using light interference utilizing a refractive index difference, and has, for example, a structure in which high refractive index layers and low refractive index layers are alternately laminated. Here, since the near-infrared absorbing material used in the present invention has a refractive index as high as 2.3 or more, by forming a film in which the near-infrared absorbing material is dispersed by blending with an appropriate binder or the like, The coating can be applied as a part of the antireflection film as a high refractive index layer.

  Here, a variety of binders can be used, but may be appropriately selected depending on the type of base material, required characteristics of the filter, filter configuration, and the like. Specific examples include ultraviolet curable resins, thermosetting resins, thermoplastic resins, room temperature curable resins, metal alkoxides, sol-gel solutions using metal alkoxide hydrolysis polymers, and various adhesive materials. In particular, when an ultraviolet curable resin is used, the production efficiency in the manufacturing process is high, and since the ultraviolet curable resin also has a hard coat property, by using an ultraviolet curable hard coat resin as a binder, It becomes possible to obtain a near-infrared absorbing material filter that achieves both wear resistance imparting to a substrate and a near-infrared absorbing function in a single layer.

  In the above coating, the film thickness of the coating and the blending amount of the tungsten oxide fine particles and / or the composite tungsten oxide fine particles are determined so that the optical characteristics of the obtained near-infrared absorption filter are transmitted in the visible light region having a wavelength of 380 nm to 780 nm. What is necessary is just to set suitably in the range from which the maximum value of a ratio is 50% or more and the minimum value of the near-infrared transmittance of wavelengths 800nm-1100nm is 30% or less.

  Near-infrared absorbing materials such as organic compounds and metal complexes are decomposed by ultraviolet rays and heat. Disperse them in ultraviolet curable resins, use in combination with binders that cure at high temperatures, and use low-solubility alcohol or water as a solvent. However, in the present invention, since the powder of inorganic oxide fine particles having high stability is applied as described above, it can be kneaded into an ultraviolet curable resin. The UV curing can cure the film with an irradiation time of several seconds or less, and the present invention is extremely useful because it is a method with very high production efficiency.

When glass is used as the filter substrate, a metal alkoxide such as silicate can be used as the binder. By applying a mixture of tungsten oxide fine particles or / and composite tungsten oxide fine particles and a metal alkoxide uniformly onto glass and baking, it is possible to obtain a near-infrared absorbing material filter having high surface strength. The film thickness of the fired film and the compounding amount of the tungsten oxide fine particles and / or the composite tungsten oxide fine particles are such that the optical characteristics of the near-infrared absorbing material filter are the maximum transmittance in the visible light region with a wavelength of 380 nm to 780 nm. May be set appropriately within a range where the minimum value of the near-infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less.
The obtained near-infrared absorbing material filter is provided on the front surface of the PDP main body by an appropriate method such as a mechanical method or an adhesion method, thereby avoiding a situation in which surrounding electronic devices malfunction due to near-infrared rays generated from the PDP. We were able to.

  Further, by selecting a material having adhesiveness as a binder, the PDP main body is provided with a near infrared absorption function for an adhesive layer when a plastic film or board is bonded to the front glass of the PDP main body. It is also possible to make a near-infrared absorbing material filter using the front glass as a base material and the adhesive layer as a near-infrared absorbing layer.

  In addition, by selecting the binder, the dispersion of the near-infrared absorbing material according to the present invention is directly applied to the front glass of the PDP main body, and after evaporating the solvent, various optimal curing methods are used. It is also possible to use a near-infrared absorbing material filter in which a front glass of the PDP main body is used as a base material and a coating film in which a near-infrared absorbing material is dispersed is provided on the base material.

  On the other hand, dyes and pigments can be added to the dispersion of the near-infrared absorbing material for color tone adjustment. In particular, color tone adjustment that contributes to improving the contrast of the PDP main body is an effective method for improving the image quality of the PDP.

  Further, tungsten oxide fine particles or / and composite tungsten oxide fine particles, and near infrared absorbing materials such as organic compounds and metal complexes such as diimonium compounds, aminium compounds, phthalocyanine compounds, organometallic complexes, cyanine compounds It is also a preferred configuration to use in combination with an azo compound, a polymethine compound, a quinone compound, a diphenylmethane compound, a triphenylmethane compound, or the like. As described above, near-infrared absorbing materials such as organic compounds and metal complexes have difficulty in heat resistance, weather resistance and the like, and have limited use alone. However, tungsten oxide fine particles and / or composite tungsten oxide fine particles and It has been found that the effect of improving weather resistance can be obtained by the combined use. For this reason, mixed use of both near-infrared absorbing materials is also a preferred configuration.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not necessarily limited to these Examples.
In each of the following examples, light transmittance was measured by a method according to JIS A 5759 (however, the measurement was performed without attaching the sample to glass). That is, the transmittance was measured using a spectrophotometer (U-4000 manufactured by Hitachi, Ltd.) at 5 nm intervals in the wavelength range of 300 nm to 2600 nm.
The haze value of the film was measured based on JIS K 7105.
The average dispersed particle size was measured with a measuring device (ELS-800 manufactured by Otsuka Electronics Co., Ltd.) using a dynamic light scattering method, and the obtained values were averaged to obtain a measured value.

Example 1
Tungsten hexachloride was dissolved in ethanol little by little to obtain a solution. This solution was dried at 130 ° C. to obtain a powdery starting material. This starting material was heated at 550 ° C. for 1 hour in a reducing atmosphere (argon / hydrogen = 95/5 volume ratio). Then, after once returned to room temperature, by heating 1 hour at 800 ° C. in an argon atmosphere to prepare a W ₁₈ O ₄₉ (WO _2.72) powder.
As a result of identification of the crystal phase by X-ray diffraction, this WO _2.72 powder was observed to have a W ₁₈ O ₄₉ crystal phase and a specific surface area of 30 m ² / g.

10 parts by weight of this WO _2.72 powder, 85 parts by weight of toluene and 5 parts by weight of a dispersant were mixed and subjected to dispersion treatment to obtain a dispersion liquid (A liquid) having an average dispersed particle diameter of 80 nm. 10 parts by weight of this liquid A and 10 parts by weight of an ultraviolet curable resin for hard coat (solid content: 100%) were mixed to obtain a near-infrared absorbing material fine particle dispersion. This dispersion was applied and formed on a PET resin film (HPE-50) using a bar coater. The film thickness of the film formation was such that the maximum value of transmittance in the visible light region with a wavelength of 380 nm to 780 nm was about 70 to 80%. This film was dried at 60 ° C. for 30 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to obtain a film.

When the optical properties of this film were measured, it showed a transmittance of 71% at a wavelength of 430 nm, the maximum value of the visible light transmittance at a wavelength of 380 nm to 780 nm was 50% or more, and sufficiently transmitted light in the visible light region. Further, the transmittance is 29% at a wavelength of 800 nm, the transmittance is 19% at a wavelength of 1100 nm, the minimum value of the near infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less, and the shielding factor in the near infrared is I found it expensive. Furthermore, the haze value was 0.9%, and it was found that the transparency was extremely high. The transmission color tone was beautiful blue. Here, since the PDP generally has low blue luminance, it is effective that the film has a blue color tone.
The transmittance profile of the obtained membrane is shown in FIG.

(Example 2)
A predetermined amount of an aqueous metatungsten ammonium solution (50 wt% in terms of WO ₃ ) and an aqueous solution of thallium formate are weighed so that the molar ratio of W to Tl is 1: 0.33, and both solutions are mixed to obtain a mixed solution. It was. This mixed solution was dried at 130 ° C. to obtain a powdery starting material. This starting material was heated at 550 ° C. for 1 hour in a reducing atmosphere (argon / hydrogen = 95/5 volume ratio). Then, once After returning to room temperature, by heating 1 hour at 800 ° C. in an argon atmosphere to prepare a Tl _0.33 WO ₃ powder. The specific surface area of this powder was 20 m ² / g. Also. As a result of identifying the crystal phase of the Tl _0.33 WO ₃ powder by X-ray diffraction, a crystal phase of hexagonal tungsten bronze (composite tungsten oxide fine particles) was observed.

20 parts by weight of this Tl _0.33 WO ₃ powder, 75 parts by weight of toluene, and 5 parts by weight of a dispersant were mixed and subjected to dispersion treatment to obtain a dispersion liquid (liquid B) having an average dispersed particle diameter of 80 nm. 10 parts by weight of this B liquid and 10 parts by weight of an ultraviolet curable resin for hard coat (solid content: 100%) were mixed to obtain an infrared shielding material fine particle dispersion liquid. This infrared shielding material fine particle dispersion was applied and formed on a PET resin film (HPE-50) using a bar coater. The film thickness of the film formation was such that the maximum value of transmittance in the visible light region with a wavelength of 380 nm to 780 nm was about 70 to 80%. This film was dried at 60 ° C. for 30 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to obtain an infrared shielding film.

When the optical characteristics of this film were measured, it showed a transmittance of 75% at a wavelength of 475 nm, the maximum value of the visible light transmittance at a wavelength of 380 nm to 780 nm was 50% or more, and sufficiently transmitted light in the visible light region. Furthermore, the transmittance is 33% at a wavelength of 800 nm, the transmittance is 6% at a wavelength of 1100 nm, the minimum value of the near-infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less, and the near-infrared shielding rate is high. I understood. Furthermore, the haze value was 0.9%, and it was found that the transparency was extremely high. The transmission color tone was beautiful blue. Here, since the PDP generally has low blue luminance, it is effective that the film has a blue color tone.
The transmittance profile of the obtained film is shown in FIG.

(Example 3)
A predetermined amount of an aqueous metatungsten ammonium solution (50 wt% in terms of WO ₃ ) and an aqueous rubidium chloride were weighed so that the molar ratio of W and Rb was 1: 0.33, and both solutions were mixed to obtain a mixed solution. . This mixed solution was dried at 130 ° C. to obtain a powdery starting material. This starting material was heated at 550 ° C. for 1 hour in a reducing atmosphere (argon / hydrogen = 95/5 volume ratio). Then, once After returning to room temperature, by heating 1 hour at 800 ° C. in an argon atmosphere to prepare a Rb _0.33 WO ₃ powder. The specific surface area of this powder was 20 m ² / g. Also. As a result of identifying the crystal phase of the Rb _0.33 WO ₃ powder by X-ray diffraction, a crystal phase of hexagonal tungsten bronze (composite tungsten oxide fine particles) was observed.

20 parts by weight of this Rb _0.33 WO ₃ powder, 75 parts by weight of toluene, and 5 parts by weight of a dispersant were mixed and subjected to dispersion treatment to obtain a dispersion liquid (liquid C) having an average dispersed particle diameter of 80 nm. 10 parts by weight of this C liquid and 10 parts by weight of an ultraviolet curable resin for hard coat (solid content: 100%) were mixed to prepare an infrared shielding material fine particle dispersion liquid. This infrared shielding material fine particle dispersion was applied and formed on a PET resin film (HPE-50) using a bar coater. The film thickness of the film formation was such that the maximum value of transmittance in the visible light region with a wavelength of 380 nm to 780 nm was about 70 to 80%. This film was dried at 60 ° C. for 30 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to obtain an infrared shielding film.

When the optical properties of this film were measured, it showed a transmittance of 76% at a wavelength of 465 nm, the maximum value of visible light transmittance at a wavelength of 380 nm to 780 nm was 50% or more, and sufficiently transmitted light in the visible light region. Furthermore, the transmittance is 24% at a wavelength of 800 nm, the transmittance is 4% at a wavelength of 1100 nm, the minimum value of the near infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less, and the shielding rate in the near infrared is low. I found it expensive. Furthermore, the haze value was 0.9%, and it was found that the transparency was extremely high. The transmission color tone was beautiful blue. Here, since the PDP generally has low blue luminance, it is effective that the film has a blue color tone.
The transmittance profile of the obtained film is shown in FIG.

Example 4
A predetermined amount of an aqueous metatungsten ammonium solution (50 wt% in terms of WO ₃ ) and an aqueous potassium chloride solution were weighed so that the molar ratio of W and K was 1: 0.33, and both solutions were mixed to obtain a mixed solution. . This mixed solution was dried at 130 ° C. to obtain a powdery starting material. This starting material was heated at 550 ° C. for 1 hour in a reducing atmosphere (argon / hydrogen = 95/5 volume ratio). Then, once After returning to room temperature, by heating 1 hour at 800 ° C. in an argon atmosphere to prepare a K _0.33 WO ₃ powder. The specific surface area of this powder was 20 m ² / g. Also. As a result of identifying the crystal phase of the K _0.33 WO ₃ powder by X-ray diffraction, a crystal phase of hexagonal tungsten bronze (composite tungsten oxide fine particles) was observed.

20 parts by weight of this K _0.33 WO ₃ powder, 75 parts by weight of toluene, and 5 parts by weight of a dispersant were mixed and subjected to dispersion treatment to obtain a dispersion liquid (P liquid) having an average dispersed particle diameter of 80 nm. 10 parts by weight of this P solution and 10 parts by weight of an ultraviolet curable resin for hard coat (solid content: 100%) were mixed to prepare an infrared shielding material fine particle dispersion liquid. This infrared shielding material fine particle dispersion was applied and formed on a PET resin film (HPE-50) using a bar coater. The film thickness of the film formation was such that the maximum value of transmittance in the visible light region with a wavelength of 380 nm to 780 nm was about 70 to 80%. This film was dried at 60 ° C. for 30 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to obtain an infrared shielding film.

When the optical characteristics of this film were measured, it showed a transmittance of 76% at a wavelength of 460 nm, the maximum value of the visible light transmittance at a wavelength of 380 nm to 780 nm was 50% or more, and sufficiently transmitted light in the visible light region. Further, the transmittance is 39% at a wavelength of 800 nm, the transmittance is 10% at a wavelength of 1100 nm, the minimum value of the near infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less, and the shielding rate in the near infrared is low. I found it expensive. Furthermore, the haze value was 0.9%, and it was found that the transparency was extremely high. The transmission color tone was beautiful blue. Here, since the PDP generally has low blue luminance, it is effective that the film has a blue color tone.
The transmittance profile of the obtained membrane is shown in FIG.

(Example 5)
A predetermined amount of a tungsten trioxide hydrate powder and a cesium carbonate powder described in WO ₃ · H ₂ O are weighed to a molar ratio of W to Cs of 1:33, The mixed powder was used as a starting material. This starting material was heated in a reducing atmosphere (argon / hydrogen = 97/3 volume ratio) at 600 ° C. for 1 hour, replaced with an argon atmosphere, and then heated at 800 ° C. for 1 hour to obtain Cs _0.33 WO ₃ powder. Produced. The specific surface area of this powder was 20 m ² / g. As a result of identifying the crystal phase of the Cs _0.33 WO ₃ powder by X-ray diffraction, a crystal phase of hexagonal tungsten bronze (composite tungsten oxide fine particles) was observed.

20 parts by weight of this Cs _0.33 WO ₃ powder, 75 parts by weight of toluene and 5 parts by weight of a dispersant were mixed and subjected to dispersion treatment to obtain a dispersion liquid (R liquid) having an average dispersed particle diameter of 80 nm. 10 parts by weight of the R liquid and 10 parts by weight of an ultraviolet curable resin for hard coat (solid content: 100%) were mixed to obtain an infrared shielding material fine particle dispersion liquid. This infrared shielding material fine particle dispersion was applied and formed on a PET resin film (HPE-50) using a bar coater. The film thickness of the film formation was such that the maximum value of transmittance in the visible light region with a wavelength of 380 nm to 780 nm was about 70 to 80%. This film was dried at 60 ° C. for 30 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to obtain an infrared shielding film.

When the optical characteristics of this film were measured, it showed a transmittance of 77% at a wavelength of 480 nm, the maximum value of visible light transmittance at a wavelength of 380 nm to 780 nm was 50% or more, and sufficiently transmitted light in the visible light region. Further, the transmittance is 19% at a wavelength of 800 nm, the transmittance is 6% at a wavelength of 1100 nm, the minimum value of the near infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less, and the near infrared shielding factor is I found it expensive. Furthermore, the haze value was 0.9%, and it was found that the transparency was extremely high. The transmission color tone was beautiful blue. Here, since the PDP generally has low blue luminance, it is effective that the film has a blue color tone.
The transmittance profile of the obtained film is shown in FIG.

(Example 6)
A predetermined amount of tungsten trioxide hydrate powder and sodium carbonate powder described in WO ₃ · H ₂ O are weighed to a molar ratio of W to Na of 1:50, The mixed powder was used as a starting material. This starting material was heated in a reducing atmosphere (argon / hydrogen = 97/3 volume ratio) at 600 ° C. for 1 hour, and after replacing with an argon atmosphere, it was heated at 800 ° C. for 1 hour, whereby Na _0.5 WO ₃ The powder of was produced. The specific surface area of this powder was 20 m ² / g. Further, as a result of identification of the crystal phase of the Na _0.5 WO ₃ powder by X-ray diffraction, a crystal phase of cubic tungsten bronze (composite tungsten oxide fine particles) was observed.

20 parts by weight of this Na _0.5 WO ₃ powder, 75 parts by weight of toluene and 5 parts by weight of a dispersant were mixed and subjected to dispersion treatment to obtain a dispersion liquid (R liquid) having an average dispersed particle diameter of 80 nm. 10 parts by weight of the R liquid and 10 parts by weight of an ultraviolet curable resin for hard coat (solid content: 100%) were mixed to obtain an infrared shielding material fine particle dispersion liquid. This infrared shielding material fine particle dispersion was applied and formed on a PET resin film (HPE-50) using a bar coater. The film thickness of the film formation was such that the maximum value of transmittance in the visible light region with a wavelength of 380 nm to 780 nm was about 70 to 80%. This film was dried at 60 ° C. for 30 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to obtain an infrared shielding film.

When the optical properties of this film were measured, it showed a transmittance of 72% at a wavelength of 465 nm, the maximum value of the visible light transmittance at a wavelength of 380 nm to 780 nm was 50% or more, and the light in the visible light region was sufficiently transmitted. Further, the transmittance is 16% at a wavelength of 800 nm, the transmittance is 5.8% at a wavelength of 1100 nm, the minimum value of the near infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less, and the near infrared shielding factor It turned out to be expensive. Furthermore, the haze value was 0.9%, and it was found that the transparency was extremely high. The transmission color tone was beautiful blue. Here, since the PDP generally has low blue luminance, it is effective that the film has a blue color tone.
The transmittance profile of the obtained film is shown in FIG.

(Example 7)
A predetermined amount of tungsten trioxide hydrate powder and potassium carbonate powder described in WO ₃ · H ₂ O are weighed to a molar ratio of W to K of 1 to 0.55. The mixed powder was used as a starting material. This starting material was heated in a reducing atmosphere (argon / hydrogen = 97/3 volume ratio) at 600 ° C. for 1 hour, replaced with an argon atmosphere, and then heated at 800 ° C. for 1 hour, whereby K _0.55 WO ₃ A powder was prepared. The specific surface area of this powder was 30 m ² / g. Further, as a result of identification of the crystal phase of the K _0.55 WO ₃ powder by X-ray diffraction, a crystal phase of tetragonal tungsten bronze (composite tungsten oxide fine particles) was observed.

20 parts by weight of this K _0.55 WO ₃ powder, 75 parts by weight of toluene and 5 parts by weight of a dispersant were mixed and subjected to dispersion treatment to obtain a dispersion liquid (S liquid) having an average dispersed particle diameter of 80 nm. 10 parts by weight of this S liquid and 10 parts by weight of an ultraviolet curable resin for hard coat (solid content: 100%) were mixed to prepare an infrared shielding material fine particle dispersion liquid. This infrared shielding material fine particle dispersion was applied and formed on a PET resin film (HPE-50) using a bar coater. The film thickness of the film formation was such that the maximum value of transmittance in the visible light region with a wavelength of 380 nm to 780 nm was about 70 to 80%. This film was dried at 60 ° C. for 30 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to obtain an infrared shielding film.

When the optical properties of this film were measured, it showed a transmittance of 75% at a wavelength of 460 nm, the maximum visible light transmittance at a wavelength of 380 nm to 780 nm was 50% or more, and the light in the visible light region was sufficiently transmitted. Furthermore, the transmittance is 21% at a wavelength of 800 nm, the transmittance is 10% at a wavelength of 1100 nm, the minimum near infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less, and the near infrared shielding rate is high. I understood. Furthermore, the haze value was 0.9%, and it was found that the transparency was extremely high. The transmission color tone was beautiful blue. Here, since the PDP generally has low blue luminance, it is effective that the film has a blue color tone.
The transmittance profile of the obtained film is shown in FIG.

(Example 8)
20 parts by weight of Cs _0.33 WO ₃ powder prepared in Example 5, 75 parts by weight of toluene, and 5 parts by weight of a dispersant were mixed and dispersed to obtain a dispersion having an average dispersed particle diameter of 80 nm. . Using a vacuum dryer, the solvent component of the dispersion was removed at 50 ° C. to obtain a powder. After this powder and PET resin are dry-mixed in a V-blender, the temperature is raised to around the melting temperature of the PET resin, sufficiently closed and mixed to form a mixture, and the mixture is melt-extruded to have a film thickness of about 50 μm. The film was formed into a near infrared absorbing film. At this time, Cs _0.33 WO ₃ fine particles were prepared so as to be contained in the obtained film at about 1.3 g / m ² .

  When the optical properties of this film were measured, it showed a transmittance of 70% at a wavelength of 475 nm, the maximum value of the visible light transmittance at a wavelength of 380 nm to 780 nm was 50% or more, and sufficiently transmitted light in the visible light region. Further, the transmittance is 10% at a wavelength of 800 nm, the transmittance is 2% at a wavelength of 1100 nm, the minimum value of the near-infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less, and the near-infrared shielding rate is high. I understood. Furthermore, the haze value was 0.9%, and it was found that the transparency was extremely high. The transmission color tone was beautiful blue. Here, since the PDP generally has low blue luminance, it is effective that the film has a blue color tone.

(Comparative Example 1)
The optical properties of the 50 μm-thick PET film itself used as the substrate in Examples 1 to 8 were measured. Then, the transmittance is 88% at a wavelength of 550 nm, the maximum value of visible light transmittance at a wavelength of 380 nm to 780 nm is 50% or more, and the visible light region is sufficiently transmitted, but the transmittance is 85% at a wavelength of 1000 nm. It was found that the minimum value of the near-infrared transmittance at wavelengths of 800 nm to 1100 nm exceeded 30%, and almost all the near-infrared light was transmitted.

(Comparative Example 2)
IRG-022 manufactured by Nippon Kayaku Co., Ltd., which is an organic near-infrared absorbing dye, is dissolved in dimethylformamide (DMF), 10 parts by weight of this solution, and 10 parts by weight of an ultraviolet curable resin for hard coat (solid content 100%). Were mixed to obtain a coating solution. This coating liquid was applied and formed on a PET resin film (HPE-50) using a bar coater. This film was dried at 60 ° C. for 30 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to obtain an infrared shielding film. Then, the obtained film was changed from a green color tone immediately after coating (before drying) to a yellow color tone. This is presumably because the organic near-infrared absorbing dye deteriorated during UV curing. Because of this deterioration, a resin that absorbs near-infrared rays cannot be produced using a highly productive UV curing method, which is not industrially useful.

(Comparative Example 3)
Tungsten hexachloride was dissolved in ethanol little by little to obtain a solution. This solution was dried at 130 ° C. to obtain a powdery starting material. This starting material was heated at 550 ° C. for 1 hour in a reducing atmosphere (argon / hydrogen = 95/5 volume ratio). Then, after once returned to room temperature, by heating 1 hour at 800 ° C. in an argon atmosphere to prepare a W ₁₈ O ₄₉ (WO _2.72) powder.
As a result of identification of the crystal phase by X-ray diffraction, the WO _2.72 powder was observed to have a W ₁₈ O ₄₉ crystal phase and a specific surface area of 30 m ² / g.

10 parts by weight of this WO _2.72 powder, 85 parts by weight of toluene, and 5 parts by weight of a dispersant were mixed, and only agitation was performed without performing a dispersion treatment. The average dispersed particle size at this time was about 2000 nm. 10 parts by weight of this liquid and 10 parts by weight of an ultraviolet curable resin for hard coat (solid content: 100%) were mixed to obtain a near-infrared absorbing material fine particle dispersion. This dispersion was applied and formed on a PET resin film (HPE-50) using a bar coater. The film thickness of the film formation was such that the maximum value of transmittance in the visible light region with a wavelength of 380 nm to 780 nm was about 70 to 80%. This film was dried at 60 ° C. for 30 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to obtain a film.
When the optical properties of this film were measured, the haze value was 18.8%, and it was difficult to project a clear image with large light scattering.

(Comparative Example 4)
Tungsten hexachloride was dissolved in ethanol little by little to obtain a solution. This solution was dried at 130 ° C. to obtain a powdery starting material. This starting material was heated in the atmosphere at 800 ° C. for 1 hour to produce WO ₃ powder. As a result of identification of the crystal phase of the WO ₃ powder by X-ray diffraction, the crystal phase of WO ₃ was observed and the specific surface area was 30 m ² / g.

10 parts by weight of this WO ₃ powder, 85 parts by weight of toluene, and 5 parts by weight of a dispersant were mixed and subjected to dispersion treatment to obtain a dispersion having an average dispersed particle diameter of 80 nm. 10 parts by weight of this dispersion and 10 parts by weight of an ultraviolet curable resin for hard coat (solid content: 100%) were mixed to obtain a fine particle dispersion. This fine particle dispersion was applied and formed on a PET resin film (HPE-50) using a bar coater. The film thickness of the film formation was such that the maximum value of transmittance in the visible light region with a wavelength of 380 nm to 780 nm was about 70 to 80%. This film was dried at 60 ° C. for 30 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to obtain a film.

When the optical properties of this film were measured, it showed a transmittance of 82.5% at a wavelength of 550 nm, the maximum value of visible light transmittance at a wavelength of 380 nm to 780 nm was 50% or more, and sufficiently transmitted light in the visible light region. However, the transmittance was 82.2% at a wavelength of 800 nm, the transmittance was 77.9% at a wavelength of 1100 nm, and the minimum value of the near infrared transmittance at a wavelength of 800 nm to 1100 nm exceeded 30%. It was found that the infrared absorptivity is low and the function as a near infrared absorbing material is inferior.
The transmittance profile of the obtained film is shown in FIG.

It is an expanded sectional view which shows the outline of the light emission part of PDP. 2 is a transmittance profile of the film according to Example 1. 4 is a transmittance profile of a film according to Example 2. 10 is a transmittance profile of a film according to Example 3. 10 is a transmittance profile of a film according to Example 4; 10 is a transmittance profile of a film according to Example 5. 10 is a transmittance profile of a film according to Example 6. 10 is a transmittance profile of a film according to Example 7. It is the transmittance | permeability profile of the film | membrane which concerns on the comparative example 4.

Explanation of symbols

11. Front glass substrate (front cover plate)
12 Display electrode 13. Dielectric glass layer 14. Protective layer 15. Back glass substrate 16. Address electrode 17. Septum 18. Phosphor layer 19. Discharge space

Claims (16)

A plasma display panel having a base material and a resin or metal oxide film provided on the surface of the base material, wherein particles of a near-infrared absorbing material are dispersed in the base material and / or in the film Near-infrared absorbing material filter for
The near-infrared absorbing material particles include tungsten oxide fine particles and / or composite tungsten oxide fine particles having an average dispersed particle size of 800 nm or less,
A near-infrared absorbing material filter for a plasma display panel, wherein the maximum value of visible light transmittance at a wavelength of 380 nm to 780 nm is 50% or more and the minimum value of near-infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less . A near-infrared absorbing material filter for a plasma display panel in which a sheet-like or film-like resin is sandwiched between base materials and particles of the near-infrared absorbing material are dispersed in the resin or / and the base material,
The near-infrared absorbing material particles include tungsten oxide fine particles and / or composite tungsten oxide fine particles having an average dispersed particle size of 800 nm or less,
A near-infrared absorbing material filter for a plasma display panel, wherein the maximum value of visible light transmittance at a wavelength of 380 nm to 780 nm is 50% or more and the minimum value of near-infrared transmittance at a wavelength of 800 nm to 1100 nm is 30% or less .   The resin or coating is a laminate of two or more layers having different refractive indexes, and has a structure that exhibits an antireflection function due to a difference in refractive index between the laminates, and at least one of the laminates 3. The near-infrared absorption filter for plasma display panel according to claim 1, wherein tungsten oxide fine particles and / or composite tungsten oxide fine particles having an average dispersed particle diameter of 800 nm or less are dispersed in the layer.   The near-infrared absorbing material further includes a diimonium compound, an aminium compound, a phthalocyanine compound, an organometallic complex, a cyanine compound, an azo compound, a polymethine compound, a quinone compound, a diphenylmethane compound, and a triphenylmethane compound. The near-infrared absorption filter for a plasma display panel according to any one of claims 1 to 3, comprising one or more selected organic compounds.   The tungsten oxide fine particles are tungsten oxide fine particles represented by a general formula WyOz (W is tungsten, O is oxygen, 2.2 ≦ z / y ≦ 2.999). Item 4. A near-infrared absorption filter for a plasma display panel according to any one of Items 1 to 3.   The composite tungsten oxide fine particles have the general formula MxWyOz (where the M element is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir). Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti , Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, one or more elements, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1. The near-infrared absorption filter for a plasma display panel according to any one of claims 1 to 3, wherein the fine particle is a composite tungsten oxide represented by (1, 2.2≤z / y≤3.0). .   The tungsten oxide fine particles or / and the composite tungsten oxide fine particles are composed of a magnetic phase having a composition ratio represented by the general formula WyOz (W is tungsten, O is oxygen, 2.45 ≦ z / y ≦ 2.999). The near-infrared absorption filter for plasma display panels according to any one of claims 1 to 3, wherein   The near-infrared absorption filter for a plasma display panel according to claim 6, wherein the composite tungsten oxide fine particles include one or more crystal structures of hexagonal, tetragonal, and cubic.   M element of the composite tungsten oxide fine particles is one or more elements selected from Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn, and the composite tungsten oxide fine particles 9. The near-infrared absorption filter for a plasma display panel according to claim 8, wherein has a hexagonal crystal structure.   The surface of the tungsten oxide fine particles and / or composite tungsten oxide fine particles is coated with an oxide containing one or more elements selected from Si, Ti, Zr, and Al. The near-infrared absorption filter for plasma display panels in any one of 5-9.   The near-infrared absorption for a plasma display panel according to any one of claims 1 to 3, wherein the substrate is composed of one or more types of substrates selected from a plastic board, a plastic film, and glass. filter.   The base material is selected from polyolefin resin, polyester resin, polycarbonate resin, poly (meth) acrylate resin, polystyrene, polyvinyl chloride, polyvinyl acetate, polyarylate resin, and polyethersulfone resin. The near-infrared absorption filter for a plasma display panel according to claim 11, which is a plastic board or a plastic film containing one or more kinds of resins.   The coating film has one or more components selected from an ultraviolet curable resin, a thermoplastic resin, a thermosetting resin, a room temperature curable resin, a metal alkoxide, a hydrolysis polymer of a metal alkoxide, and an adhesive material. Item 4. A near-infrared absorption filter for a plasma display panel according to any one of Items 1 to 3.   The near-infrared absorbing filter for a plasma display panel according to claim 2, wherein the sheet-like or film-like resin is polyvinyl butyral. A near-infrared absorption filter for a plasma display panel according to any one of claims 1 to 3,
Furthermore, the near-infrared absorption filter for plasma display panels characterized by containing a color tone adjustment component.   A near-infrared absorption filter for a plasma display panel according to any one of claims 1 to 15, wherein the plasma display panel is provided.

Images