JP2009271515A - Near-infrared-shielding structure and optical filter for display employing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a near-infrared-shielding structure which is superior in the property of shielding near infrared rays. <P>SOLUTION: The optical filter for a display is characterized by having a near-infrared-shielding layer and at least another functional layer. The near-infrared-shielding layer includes: a tungsten oxide and/or a composite tungsten oxide; and a pressure-sensitive adhesive having acid groups. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a near-infrared shield having a near-infrared shielding function, a display optical filter having a near-infrared shielding function suitable for a plasma display panel (PDP) and the like.

  Usually, a front filter is always used for a PDP. This front filter is used for the purpose of near-infrared cut, color reproducibility improvement (light emission color purity improvement), electromagnetic wave shield, bright place contrast improvement (antireflection), light emission panel protection, heat insulation from the light emission panel, etc. .

  It is necessary to reduce the near infrared rays emitted from the light emitting panel of the PDP in order to avoid malfunctioning the remote control used for home television and video. In addition, it is necessary to suppress the electromagnetic waves emitted by the light emitting panel of the PDP in order to avoid adverse effects on the human body and precision equipment. Further, in order to make the light emitted from the light emitting panel of the PDP feel a natural color for human vision, there is a demand for improvement in color reproducibility (light emission color purity improvement) by correction with a filter. Furthermore, it is desirable that the display on the display be visually recognized with sufficient contrast without being hindered by reflection of light from the outside even in a bright place such as a bright room. In addition, even when the display product is directly touched by hand, it is desirable that the heat generated by the light emitting panel of the PDP is cut off in order to avoid a situation where the user is surprised by the high temperature.

  In general, optical filters having various functions such as antireflection, near-infrared shielding, and electromagnetic wave shielding are used as optical filters for PDPs that meet the above-mentioned purpose. However, in actuality, it is used as an optical filter for PDP by bonding optical filters having respective functions and optical filters having two functions in an appropriate combination.

  Near infrared rays emitted from the above-described plasma display cause malfunction of peripheral electronic devices, and therefore, particularly effective blocking is required.

  For example, as an optical filter having a function of blocking near infrared rays, Patent Document 1 (JP 2001-133624 A) discloses a transparent resin film layer (1) and a transparent near infrared ray containing a diimonium compound as a near infrared absorber. It has a multilayer structure in which a shielding layer (2), a transparent resin film layer (3), and a transparent color tone compensation layer (4) containing a color material that compensates the color tone of the transparent near-infrared shielding layer (2) are laminated. The near-infrared shielding film characterized by this is disclosed.

JP 2001-133624 A JP 2006-287236 A (described later)

  In order to simplify the structure of the optical filter, there are increasing demands for reducing the number of layers constituting the filter by imparting various functions to the pressure-sensitive adhesive layer.

  On the other hand, with respect to the near-infrared shielding effect, when a near-infrared shielding layer containing a diimonium compound as a near-infrared absorber as described in Patent Document 1 is used, the near-infrared absorbing function is maintained for a long time. However, it has been revealed by the inventor that the durability is not sufficient. Patent Document 2 (Japanese Patent Application Laid-Open No. 2006-287236) proposes a tungsten oxide and a composite tungsten oxide (hereinafter also referred to as (composite) tungsten oxide) excellent in near-infrared shielding properties.

  The (composite) tungsten oxide has a strong absorption in the near infrared and is extremely effective in preventing malfunction of the peripheral electronic device. Such (composite) tungsten oxide is generally commercially available as a dispersion in which fine particles are dispersed in a medium. In order to form the near-infrared blocking layer, it is necessary to mix this dispersion and the pressure-sensitive adhesive, but according to the study of the present inventors, the fine particles of (composite) tungsten oxide are likely to aggregate due to these mixing, It has been found that the obtained near-infrared shielding layer cannot obtain a predetermined near-infrared absorbing ability.

  Accordingly, an object of the present invention is to provide a near-infrared shield having excellent near-infrared shielding properties and durability that retains its function for a long period of time.

  Another object of the present invention is to provide an optical filter for a display that has excellent near-infrared blocking properties and durability for maintaining the function for a long period of time, and has improved display characteristics.

  Furthermore, an object of the present invention is to provide an optical filter for a plasma display panel which has excellent near-infrared shielding properties and durability for maintaining the function for a long period of time, and further has improved display characteristics.

  According to further studies by the present inventors, the pressure-sensitive adhesive that easily causes aggregation of fine particles of (composite) tungsten oxide is a general neutral pressure-sensitive adhesive and has an acidic group (particularly a carboxylic acid group). It has been clarified that the problem of aggregation is solved by using.

The present invention
A near-infrared shield comprising a tungsten oxide and / or a composite tungsten oxide and an adhesive having an acidic group;
It is in.

  In the present invention, the pressure-sensitive adhesive means a pressure-sensitive resin and is preferably used together with a curing agent.

Preferred embodiments of the near-infrared shield of the present invention are as follows.
(1) The acid value of the pressure-sensitive adhesive is 0.5 KOH mg / g or more. Tungsten oxide and / or composite tungsten oxide can be well dispersed.
(2) The pressure-sensitive adhesive is an acrylic resin-based pressure-sensitive adhesive.
(3) The acidic group of the pressure-sensitive adhesive is a carboxyl group. Tungsten oxide and / or composite tungsten oxide can be well dispersed.
(4) Tungsten oxide and / or composite tungsten oxide is in the form of fine particles. Good near-infrared shielding effect.
(5) The average particle diameter of the fine particles is 400 nm or less. Good near-infrared shielding effect.
(6) The tungsten oxide is represented by the general formula WyOz (where W represents tungsten, O represents oxygen, and 2.2 ≦ z / y ≦ 2.999),
The composite tungsten oxide has the general formula MxWyOz (where M 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, One or more elements selected from V, Mo, Ta, Re, Be, Hf, Os, Bi, I, W represents tungsten, O represents oxygen, and 0.001 ≦ x / y ≦ 1,2. 0.2 ≦ z / y ≦ 3). A composite tungsten oxide is preferable because of its excellent near-infrared absorptivity.
(7) It further contains a curing agent (preferably an isocyanate curing agent or an epoxy curing agent). Adhesion is improved.
(8) The minimum value of the transmittance of near infrared light in the wavelength region of 800 to 1100 nm is 30% or less. Good near-infrared shielding effect.
(9) Tungsten oxide and / or composite tungsten oxide is used in the state of dispersion. It is easy to form a near-infrared shielding layer.

The present invention also provides:
An optical filter for display comprising a near-infrared shielding layer, wherein the near-infrared shielding layer comprises tungsten oxide and / or composite tungsten oxide and an adhesive having an acidic group;
There is also.

Preferred embodiments of the optical filter for display according to the present invention are as follows.
(1) A preferred embodiment of the near-infrared shield of the present invention can also be applied to the optical filter for display of the present invention.
(2) The near-infrared shielding layer further contains a curing agent (preferably an isocyanate curing agent or an epoxy curing agent). Adhesion is improved.
(3) Further, at least one other functional layer is included. It is preferable that at least one other functional layer is an antireflection layer.
(4) A conductive layer is further included.
(5) A filter for a plasma display panel.
(6) A substrate having an antireflection layer on the front surface and a near infrared shielding layer on the back surface, and another substrate having a conductive layer on the front surface and an adhesive layer on the back surface, the near infrared shielding layer and the conductive layer face each other. A near-infrared shielding optical filter including a laminate bonded in a state,
An optical filter for display, wherein the near-infrared shielding layer contains tungsten oxide and / or composite tungsten oxide and an adhesive having an acidic group.

Furthermore, the present invention provides
A display optical filter in which a conductive layer and an antireflection layer are provided in this order on one surface of a substrate, and a near-infrared shielding layer is provided on the other surface of the substrate,
An optical filter for display, wherein the near-infrared shielding layer includes tungsten oxide and / or composite tungsten oxide and an adhesive having an acidic group;
There is also.

Preferred embodiments of the optical filter for display according to the present invention are as follows.
(1) A preferred embodiment of the near-infrared shield of the present invention can also be applied to the optical filter for display of the present invention.
(2) A curing agent (preferably an isocyanate curing agent or an epoxy curing agent) is further included. Adhesion is improved.
(3) Furthermore, an adhesive layer is included.
(4) A plasma display panel filter.

Preferred embodiments of all the optical filters for display described above are as follows.
(1) Any of the above layers (generally a near-infrared shielding layer or an adhesive layer) has a neon cut function.
(2) The conductive layer is a mesh-like metal conductive layer. The aperture ratio is preferably 50% or more.
(3) The minimum transmittance of visible light in the wavelength range of 560 to 610 nm is 60% or less in the wavelength range.
(4) The substrate is generally a transparent substrate (particularly a transparent plastic film).
(5) A display optical filter in which a display optical filter is attached to a glass substrate.

  Furthermore, it is natural that a display including the display optical filter; and a plasma display panel including the display optical filter exhibit excellent near-infrared shielding properties.

  The near-infrared shielding layer (near-infrared shielding body) suitable for the optical filter for display of this invention contains the tungsten oxide and / or composite tungsten oxide which cut off near infrared rays efficiently, and has an acidic group ( Binder resin). For this reason, the (composite) tungsten oxide is uniformly dispersed as fine fine particles in the pressure-sensitive adhesive, and exhibits excellent near-infrared shielding properties. Therefore, when the display optical filter having such a near-infrared shielding layer is used as an optical filter of a PDP, the display image of the obtained PDP is effectively cut off from near-infrared light. The malfunction is significantly prevented. Furthermore, such a near-infrared cut function can be maintained for a long time. At the same time, the visibility of the display image is excellent. For this reason, the optical filter for display of this invention has the outstanding near-infrared shielding property and durability, and shows the outstanding display characteristic.

  Moreover, since the near-infrared shielding body of this invention has the outstanding near-infrared shielding property as mentioned above, it is useful also for uses other than a display, for example, a window glass, a showcase, etc. from the same viewpoint.

It is a schematic sectional drawing of one typical example of the optical filter for displays of this invention. It is a schematic sectional drawing of an example of the suitable aspect of the optical filter for displays of this invention. It is a schematic sectional drawing of another example of the suitable aspect of the optical filter for displays of this invention. It is a schematic sectional drawing of another example of the suitable aspect of the optical filter for displays of this invention. It is a schematic sectional drawing of another example of the suitable aspect of the optical filter for displays of this invention. It is a schematic sectional drawing of an example of the state where the optical filter of this invention was affixed on the image display surface of the plasma display panel which is 1 type of a display.

  The display optical filter of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of the basic configuration of the optical filter of the present invention.

  The optical filter of the present invention has a configuration in which a transparent substrate 11, an antireflection layer 12 formed on one surface of the transparent substrate 11, and a near infrared shielding layer 13 formed on the other surface of the transparent substrate 11 are provided. Have. In the present invention, the near-infrared shielding layer 13 includes both tungsten oxide and / or composite tungsten oxide and an adhesive having an acidic group. Since the near-infrared shielding layer 13 has tungsten oxide and / or composite tungsten oxide dispersed finely in a pressure-sensitive adhesive having an acidic group, harmful near-infrared rays are efficiently cut. Such an optical filter generally has a minimum value of the transmittance of near-infrared light in the wavelength region of 800 to 1100 nm of 30% or less. It is preferable that the near-infrared shielding layer 13 is made sticky and used to adhere to another optical film or the display surface. In applications that do not require the antireflection function, the antireflection layer 12 may be omitted.

  FIG. 2 shows a schematic cross-sectional view of an example of a preferred embodiment of the optical filter of the present invention. This optical filter is provided with a transparent substrate 21A, an antireflection layer 22 formed on one surface of the transparent substrate 21A, and a near-infrared shielding layer 23 having adhesiveness formed on the other surface of the transparent substrate 21A. Laminated body (same aspect as previous FIG. 1), another transparent substrate 21B, mesh-like conductive layer 24 formed on one surface of transparent substrate 21B, and neon cut dye formed on the other surface of transparent substrate 21B And another laminated body provided with the pressure-sensitive adhesive layer 25 including the adhesive layer 25 is bonded via a sticky near-infrared shielding layer 23. In the present invention, the near-infrared shielding layer 23 includes both tungsten oxide and / or composite tungsten oxide and an adhesive having an acidic group. Since the near-infrared shielding layer 23 has tungsten oxide and / or composite tungsten oxide dispersed in a pressure-sensitive adhesive having fine particles and uniform acidic groups, harmful near-infrared rays are efficiently cut off. Such an optical filter generally has a minimum value of the transmittance of near-infrared light in the wavelength region of 800 to 1100 nm of 30% or less. For this reason, a display provided with such an optical filter, particularly a PDP, exhibits excellent display characteristics.

  Such an optical filter is generally adhered to the display surface via the pressure-sensitive adhesive layer 25, or is adhered to a glass plate via the pressure-sensitive adhesive layer 25 and disposed on the front surface of the PDP.

  An example of another preferred embodiment of the optical filter of the present invention is shown in FIG. A mesh-like conductive layer (electromagnetic wave shielding layer) 34 is provided on one surface of the transparent substrate 31, an antireflection layer 32 is further provided on the conductive layer 34, and a near-infrared shielding layer is provided on the other surface of the transparent substrate 31. 33 is provided, and an adhesive layer 35 is further provided thereon. Therefore, only one transparent substrate 31 is used as a substrate, and a thin substrate can be obtained as compared with the optical filter of FIG. In this optical filter, the near-infrared shielding layer 33 efficiently cuts harmful near-infrared rays because tungsten oxide and / or composite tungsten oxide is dispersed in a pressure-sensitive adhesive that is finely divided and uniformly has acidic groups. Is done. Such an optical filter generally has a minimum value of the transmittance of near-infrared light in the wavelength region of 800 to 1100 nm of 30% or less.

  Further, as described above, the antireflection layer in the optical filter can be omitted depending on the application. An example of another preferred embodiment of such an optical filter of the present invention is shown in FIG. In this optical filter, a transparent substrate 41A, a near-infrared shielding layer 43 formed on one surface of the transparent substrate 41A, and a mesh-like material adhered to the other surface of the transparent substrate 41A via an adhesive layer 46 are used. The laminate having the conductive layer 44 and the transparent substrate 41 </ b> B are laminated via the near infrared shielding layer 43. The optical filter has a simplified configuration because it does not have an antireflection layer, and is easy to manufacture. Further, such an optical filter can be disposed on the front surface of the PDP as it is. The near-infrared shielding layer 43 includes both tungsten oxide and / or composite tungsten oxide and an adhesive having an acidic group. Therefore, the tungsten oxide and / or the composite tungsten oxide are uniformly finely dispersed in the near infrared shielding layer, and the near infrared can be cut efficiently. In such an optical filter, as described above, generally, the minimum value of the transmittance of near infrared light in the wavelength region of 800 to 1100 nm is 30% or less.

  An example of still another preferred embodiment of the optical filter of the present invention is shown in FIG. In this optical filter, the transparent substrate 51A, the mesh-like conductive layer 54 attached on one surface of the transparent substrate 51A via the adhesive layer 56, and the near infrared ray formed on the mesh-like conductive layer 54 The laminate having the shielding layer 53 and the transparent substrate 51B have a configuration in which the near-infrared shielding layer 53 and the transparent substrate 51B are laminated so as to be adjacent to each other. The optical filter has a simplified configuration because it does not have an antireflection layer, and is easy to manufacture. Further, such an optical filter can also be arranged on the front surface of the PDP as it is. The near-infrared shielding layer 53 includes both tungsten oxide and / or composite tungsten oxide and an adhesive having an acidic group. Therefore, the tungsten oxide and / or the composite tungsten oxide are uniformly finely dispersed in the near infrared shielding layer, and the near infrared can be cut efficiently. In such an optical filter, as described above, generally, the minimum value of the transmittance of near infrared light in the wavelength region of 800 to 1100 nm is 30% or less.

  The optical filter of the present invention may have any configuration as long as it includes a layer in which tungsten oxide and / or composite tungsten oxide is dispersed in a pressure-sensitive adhesive having fine particles and uniformly having acidic groups. 1 to 5, for example, the positions of the layers shown above may be appropriately changed.

  In the optical filter of the present invention, the minimum value of the transmittance in the near infrared ray in the wavelength range of 800 to 1100 nm is preferably 30% or less in the wavelength range. Thereby, harmful near infrared rays are efficiently cut. In particular, it is more preferable that the minimum transmittance of visible light in the wavelength range of 560 to 610 nm is 60% or less in the wavelength range. This may be achieved by adding a neon cut dye to an appropriate layer such as an adhesive layer or a near infrared shielding layer.

  In the present invention, generally, the antireflection layers 12, 22, and 32 are hard coat layers; whether they are composed of a hard coat layer and a low refractive index layer having a lower refractive index than the hard coat layer (in this case, the hard coat layer is It is composed of a hard coat layer, a high refractive index layer having a higher refractive index than the hard coat layer, and a low refractive index layer having a lower refractive index than the hard coat layer (in this case, the hard coat layer is a metal conductive layer). In contact with the layer). The more layers, the better the antireflection properties are generally obtained. Alternatively, the antireflection layers 12, 22, and 32 may be composed of an antiglare layer, or an antiglare layer and a low refractive index layer having a lower refractive index than the antiglare layer (the antiglare layer is in contact with the metal conductive layer). preferable. The antiglare layer is a so-called antiglare layer, generally has an excellent antireflection effect, and it is often unnecessary to provide an antireflection layer such as a low refractive index layer.

  2 and 3 show examples of the near-infrared shielding layer and the pressure-sensitive adhesive layer, but a near-infrared shielding layer, a neon cut layer, and a pressure-sensitive adhesive layer may be used. Or it consists of the transparent adhesive layer which has a near-infrared absorption function and a neon cut function, or consists of the near-infrared shielding layer which has a neon cut function, and an adhesive layer (it is provided on the transparent substrate in this order). Or it is also preferable that it consists of a near-infrared shielding layer, a neon cut layer, and an adhesive layer (provided on the transparent substrate in this order).

  As the conductive layers 24, 34, 44, 54, a mesh-like metal layer or a metal-containing layer has been shown above, but in addition, a metal oxide layer (dielectric layer), or a metal oxide layer and a metal layer, Of course, an alternate laminated film of the above may be used. The mesh-like metal layer or metal-containing layer is generally formed by etching or printing, or is a metal fiber layer. This makes it easy to obtain low resistance. In general, the mesh gap of the mesh-like metal layer or metal-containing layer is filled with an adhesive (or an adhesive near-infrared shielding layer). This improves transparency. When not filled with an adhesive, it may be filled with another layer, for example, a hard coat layer or the like, or a transparent resin layer dedicated thereto.

  The near-infrared shielding layers 13, 23, 33, 43, and 53 have a function of blocking unnecessary light from the PDP. In general, it is a layer containing the tungsten oxide and / or composite tungsten oxide of the present invention (and a compound having a maximum absorption in a wavelength region of 300 to 500 nm if necessary). The pressure-sensitive adhesive layers 25 and 35 are provided for easy mounting on the display. A release sheet may be provided on the transparent adhesive layers 25 and 35.

  The optical filter for display of the present invention is obtained, for example, by forming an antireflection layer over the entire surface of the transparent substrate, and forming a near-infrared shielding layer on the back surface of the transparent substrate and a transparent adhesive layer thereon. . Further, for example, a mesh-like metal conductive layer is formed over the entire surface of the transparent substrate, then an antireflection layer is formed over the entire mesh-like metal conductive layer, and a near-infrared shielding layer and a back surface of the transparent substrate are formed. It can also be obtained by forming a transparent adhesive layer thereon. Alternatively, using two transparent substrates, for example, on the conductive layer of a transparent substrate having a mesh-like conductive layer (generally having a pressure-sensitive adhesive layer or the like on the back surface), an antireflection layer on the front surface and an adhesive near-infrared surface on the back surface It can also be obtained by laminating and bonding a transparent substrate having a shielding layer via a near-infrared shielding layer. Alternatively, an antireflection layer such as a mesh-like metal conductive layer, an antiglare layer and a low refractive index layer is provided in this order on the surface of the transparent substrate, and the near infrared shielding layer and the upper layer are provided on the surface of another transparent substrate. A transparent pressure-sensitive adhesive layer is provided on the surface, and the surfaces of the two transparent substrates that are not provided are bonded to each other. In this case, the former laminate is produced by the method of the present invention.

  The material used for the optical filter for display of this invention is demonstrated below.

  The substrate is generally a transparent substrate, and is preferably a transparent plastic film. The material is not particularly limited as long as it is transparent (meaning “transparent to visible light”). Examples of plastic films include polyester {eg, polyethylene terephthalate (PET), polybutylene terephthalate}, polymethyl methacrylate (PMMA), acrylic resin, polycarbonate (PC), polystyrene, triacetate resin, polyvinyl alcohol, polyvinyl chloride, poly Examples thereof include vinylidene chloride, polyethylene, ethylene-vinyl acetate copolymer, polyvinyl butyral, metal ion crosslinked ethylene-methacrylic acid copolymer, polyurethane, cellophane and the like. Among these, polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), etc. are highly resistant to loads during processing (heat, solvent, bending, etc.) and particularly highly transparent. preferable. In particular, PET is preferable because it has excellent processability. In addition, glass plates such as green glass, silicate glass, inorganic glass plate, and non-colored transparent glass plate are also preferable.

  The thickness of the transparent substrate varies depending on the use of the optical filter and the like, but is generally 1 μm to 10 mm, 1 μm to 5 mm, and particularly preferably 25 to 250 μm.

  The metal conductive layer of the present invention is set so that the surface resistance value of the obtained optical filter is generally 10Ω / □ or less, preferably in the range of 0.001 to 5Ω / □, particularly 0.005 to 5Ω / □. Is done. A mesh (lattice) conductive layer is preferred. Alternatively, the conductive layer may be a layer obtained by a vapor deposition method (a transparent conductive thin film of metal oxide (ITO or the like)). Further, it may be an alternate laminate of a metal oxide dielectric film such as ITO and a metal layer such as Ag (eg, ITO / silver / ITO / silver / ITO laminate).

  The mesh-like metal conductive layer is made of metal fibers and metal-coated organic fibers made of a metal, or a copper foil layer on a transparent substrate is etched into a mesh to provide openings, on a transparent substrate Examples thereof include a conductive ink printed in a mesh shape.

  In the case of a mesh-shaped metal conductive layer, the mesh preferably has a line width of 1 μm to 1 mm made of metal fibers and / or metal-coated organic fibers and an aperture ratio of 50% or more. A more preferable wire diameter is 10 to 500 μm, and an aperture ratio is 50 to 95%. In a mesh-like conductive layer, when the line width exceeds 1 mm, the electromagnetic wave shielding property is improved, but the aperture ratio is lowered and cannot be compatible. If it is less than 1 μm, the strength as a mesh is lowered and handling becomes difficult. Further, if the aperture ratio exceeds 95%, it is difficult to maintain the shape as a mesh. If the aperture ratio is less than 50%, the light transmittance decreases and the light amount from the display also decreases.

  The opening ratio of the conductive mesh refers to the area ratio occupied by the opening portion in the projected area of the conductive mesh.

  The metal fibers constituting the mesh-like conductive layer and the metal of the metal-coated organic fiber include copper, stainless steel, aluminum, nickel, titanium, tungsten, tin, lead, iron, silver, carbon or alloys thereof, preferably copper, Stainless steel and nickel are used.

  As the organic material for the metal-coated organic fiber, polyester, nylon, vinylidene chloride, aramid, vinylon, cellulose and the like are used.

  When a conductive foil such as a metal foil is subjected to pattern etching, copper, stainless steel, aluminum, nickel, iron, brass, or an alloy thereof, preferably copper, stainless steel, or aluminum is used as the metal of the metal foil.

  If the thickness of the metal foil is too thin, it is not preferable in terms of handleability and workability of pattern etching, and if it is too thick, it affects the thickness of the film obtained, and the time required for the etching process becomes long. The thickness is preferably about 1 to 200 μm.

  The shape of the etching pattern is not particularly limited, and examples thereof include a grid-like metal foil in which square holes are formed, and a punching metal-like metal foil in which circular, hexagonal, triangular or elliptical holes are formed. It is done. Further, the holes are not limited to those regularly arranged, and may be a random pattern. It is preferable that the area ratio of the opening part in the projection surface of this metal foil is 20 to 95%. Further, those having an aperture ratio of 50% or more are preferable, and particularly 50% or more and 95% or less. The line width is preferably 10 to 500 μm.

  In addition to the above, as a mesh-shaped metal conductive layer, dots are formed on the film surface by a material soluble in a solvent, and a conductive material layer made of a conductive material insoluble in a solvent is formed on the film surface. A mesh-like metal conductive layer obtained by removing the dots and the conductive material layer on the dots by bringing the film surface into contact with a solvent may be used.

  The conductive layer may be provided directly on the substrate, or may be provided via a pressure-sensitive adhesive layer or an adhesive layer. As this pressure-sensitive adhesive layer or adhesive layer, the same layer as described later as an adhesive layer for bonding the optical film to the display is used.

  A metal plating layer may be further provided on the mesh-like metal conductive layer in order to improve the conductivity (particularly in the case of forming dots with a material soluble in the solvent). The metal plating layer can be formed by a known electrolytic plating method or electroless plating method. As the metal used for plating, generally, copper, copper alloy, nickel, aluminum, silver, gold, zinc, tin or the like can be used, preferably copper, copper alloy, silver, or nickel, In particular, it is preferable to use copper or a copper alloy from the viewpoint of economy and conductivity.

  Moreover, you may give anti-glare performance. When this anti-glare treatment is performed, a blackening treatment may be performed on the surface of the (mesh) conductive layer. For example, oxidation treatment of a metal film, black plating such as chromium alloy, application of black or dark ink, and the like can be performed.

  The antireflection layer of the present invention is generally a composite film of a hard coat layer and a low refractive index layer having a lower refractive index than the hard coat layer provided thereon, or a hard coat layer and a low refractive index layer. It is a composite film in which a high refractive index layer is further provided therebetween. The antireflection film is effective even if it is only a hard coat layer having a refractive index lower than that of the substrate.

  The hard coat layer is a layer mainly composed of a synthetic resin such as an acrylic resin layer, an epoxy resin layer, a urethane resin layer, or a silicon resin layer. The thickness is usually 1 to 50 μm, preferably 1 to 10 μm. The synthetic resin is generally a thermosetting resin or an ultraviolet curable resin, and an ultraviolet curable resin is preferable. The ultraviolet curable resin is preferable because it can be cured in a short time and has excellent productivity.

  Examples of the thermosetting resin include phenol resin, resorcinol resin, urea resin, melamine resin, epoxy resin, acrylic resin, urethane resin, furan resin, and silicon resin.

  As the hard coat layer, a cured layer of a layer mainly composed of an ultraviolet curable resin composition (consisting of an ultraviolet curable resin (monomer and / or oligomer), a photopolymerization initiator, etc.) is preferable, and the thickness thereof is usually The thickness is 1 to 50 μm, preferably 1 to 10 μm.

  Examples of the ultraviolet curable resin (monomer, oligomer) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-ethylhexyl polyethoxy (meth) acrylate. , Benzyl (meth) acrylate, isobornyl (meth) acrylate, phenyloxyethyl (meth) acrylate, tricyclodecane mono (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, acryloylmorpholine , N-vinylcaprolactam, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, o-phenylphenyloxyethyl (meth) acrylate, neopentylglyce Di (meth) acrylate, neopentyl glycol dipropoxy di (meth) acrylate, neopentyl glycol di (meth) acrylate hydroxypivalate, tricyclodecane dimethylol di (meth) acrylate, 1,6-hexanediol di (meth) Acrylate, nonanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, ditrimethylolpropane (Meth) acrylate monomers such as tetra (meth) acrylate; polyol compounds (for example, ethylene glycol, propylene glycol, neopentyl glycol, , 6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butyl-1,3-propanediol, trimethylolpropane, diethylene glycol, dipropylene glycol, polypropylene Polyols such as glycol, 1,4-dimethylolcyclohexane, bisphenol A polyethoxydiol, polytetramethylene glycol, the polyols and succinic acid, maleic acid, itaconic acid, adipic acid, hydrogenated dimer acid, phthalic acid, isophthalic acid Polyester polyols which are reaction products of polybasic acids such as acid and terephthalic acid or acid anhydrides thereof, polycaprolactone polyols which are reaction products of the polyols and ε-caprolactone, the polyols and the above, Polybasic acid or this Reaction products of these acid anhydrides with ε-caprolactone, polycarbonate polyols, polymer polyols, etc.) and organic polyisocyanates (for example, tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane-4,4′-diisocyanate, diisocyanate) Cyclopentanyl diisocyanate, hexamethylene diisocyanate, 2,4,4′-trimethylhexamethylene diisocyanate, 2,2′-4-trimethylhexamethylene diisocyanate, etc.) and a hydroxyl group-containing (meth) acrylate (for example, 2-hydroxyethyl (meta ) Acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylic Rate, cyclohexane-1,4-dimethylol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin di (meth) acrylate, etc.) (Meth) such as bisphenol type epoxy (meth) acrylate, which is a reaction product of bisphenol type epoxy resin such as polyurethane (meth) acrylate, bisphenol A type epoxy resin, bisphenol F type epoxy resin and (meth) acrylic acid which is a reaction product Examples include acrylate oligomers. These compounds can be used alone or in combination. These ultraviolet curable resins may be used as a thermosetting resin together with a thermal polymerization initiator.

  For the hard coat layer, among the above-mentioned ultraviolet curable resins (monomer, oligomer), pentaerythritol tri (meth) acrylate, pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane It is preferable to mainly use a hard polyfunctional monomer such as tri (meth) acrylate.

  Any compound suitable for the properties of the ultraviolet curable resin can be used as the photopolymerization initiator for the ultraviolet curable resin. For example, acetophenone such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1 Benzoin series such as benzyldimethyl ketal, benzophenone, 4-phenylbenzophenone, benzophenone series such as hydroxybenzophenone, thioxanthone series such as isopropylthioxanthone, 2-4-diethylthioxanthone, and other special ones include methylphenyl glyoxylate Etc. can be used. Particularly preferably, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1, Examples include benzophenone. These photopolymerization initiators may be optionally selected from one or more known photopolymerization accelerators such as benzoic acid type or tertiary amine type such as 4-dimethylaminobenzoic acid. It can be used by mixing at a ratio. Moreover, it can be used by 1 type, or 2 or more types of mixture of only a photoinitiator. Particularly preferred is 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals).

  Generally the quantity of a photoinitiator is 0.1-10 mass% with respect to a resin composition, Preferably it is 0.1-5 mass%.

  Further, the hard coat layer may contain a small amount of an ultraviolet absorber, an infrared absorber, an anti-aging agent, a paint processing aid, a colorant and the like. In particular, it is preferable to contain an ultraviolet absorber (for example, a benzotriazole-based ultraviolet absorber or a benzophenone-based ultraviolet absorber), whereby yellowing of the filter can be efficiently prevented. The amount thereof is generally 0.1 to 10% by mass, preferably 0.1 to 5% by mass, based on the resin composition.

The high refractive index layer is made of a polymer (preferably UV curable resin composition), ITO, ATO, Sb ₂ O ₃ , SbO ₂ , In ₂ O ₃ , SnO ₂ , ZnO, Al-doped ZnO, TiO _2. It is preferable to use a layer in which is dispersed (cured layer). The metal oxide fine particles preferably have an average particle size of 10 to 10,000 nm, preferably 10 to 50 nm. In particular, ITO (especially having an average particle diameter of 10 to 50 nm) is preferable. Those having a refractive index of 1.64 or more are suitable. The film thickness is generally in the range of 10 to 500 nm, preferably 20 to 200 nm.

  When the high refractive index layer is a conductive layer, the minimum reflectance of the surface reflectance of the antireflection film should be within 1.5% by setting the refractive index of the high refractive index layer to 1.64 or more. The minimum reflectance of the surface reflectance of the antireflection film can be made to be within 1.0% by setting it to 1.69 or more, preferably 1.69 to 1.82.

  The low refractive index layer is a layer (cured) in which fine particles such as silica and fluororesin, preferably 10 to 40% by mass (preferably 10 to 30% by mass) of hollow silica are dispersed in a polymer (preferably UV curable resin). Layer). The refractive index of the low refractive index layer is preferably 1.45 or less. When the refractive index is more than 1.45, the antireflection characteristic of the antireflection film is deteriorated. The film thickness is generally in the range of 10 to 500 nm, preferably 20 to 200 nm.

  As the hollow silica, those having an average particle diameter of 10 to 100 nm, preferably 10 to 50 nm, and a specific gravity of 0.5 to 1.0, preferably 0.8 to 0.9 are preferable.

  The hard coat layer preferably has a visible light transmittance of 70% or more. Both the visible light transmittance of the high refractive index layer and the low refractive index layer are preferably 85% or more.

  When the antireflection layer is composed of the hard coat layer and the above two layers, for example, the thickness of the hard coat layer is 2 to 20 μm, the thickness of the high refractive index layer is 50 to 150 nm, and the thickness of the low refractive index layer is It is preferable that it is 50-150 nm.

  In order to form each layer of the antireflection layer, for example, as described above, the above-mentioned fine particles are blended with a polymer (preferably an ultraviolet curable resin) as necessary, and the obtained coating liquid is used as the transparent substrate. After coating on the surface and then drying, it may be cured by irradiation with ultraviolet rays. In this case, each layer may be applied and cured one by one, or all the layers may be applied and then cured together.

  As a specific method of coating, a method of coating a coating solution in which an ultraviolet curable resin containing an acrylic monomer or the like is made into a solution with a solvent such as toluene is coated with a gravure coater, and then dried, and then cured by ultraviolet rays. Can be mentioned. This wet coating method has the advantage that the film can be uniformly formed at high speed at low cost. After this coating, for example, by irradiating and curing with ultraviolet rays, the effect of improving the adhesion and increasing the hardness of the film can be obtained. The conductive layer can be formed similarly.

  In the case of ultraviolet curing, many light sources that emit light in the ultraviolet to visible range can be used as the light source, such as ultra-high pressure, high pressure, low pressure mercury lamp, chemical lamp, xenon lamp, halogen lamp, mercury lamp, carbon arc lamp, incandescent lamp. And laser light. The irradiation time cannot be determined unconditionally depending on the type of lamp and the intensity of the light source, but is about several seconds to several minutes. Moreover, in order to accelerate curing, the laminate may be preheated to 40 to 120 ° C. and irradiated with ultraviolet rays.

  It is also preferable to provide an antiglare layer instead of the hard coat layer as described above. What has a large antireflection effect is easily obtained. As the antiglare layer, for example, an antiglare layer obtained by applying and drying a liquid in which a transparent filler (preferably an average particle diameter of 1 to 10 μm) such as polymer fine particles (eg, acrylic beads) is dispersed in a binder, Or the anti-glare layer which has the hard-coat function which apply | coated and hardened the liquid which added the transparent filler (polymer fine particle; for example, acrylic beads) to the above-mentioned hard-coat layer formation material can be mentioned, and is preferable. The layer thickness of the antiglare layer is generally in the range of 0.01 to 20 μm.

  As described above, the optical filter of the present invention has a near-infrared shielding layer containing a tungsten oxide and / or composite tungsten oxide that efficiently cuts near-infrared rays and a resin having an acidic group. By using a pressure-sensitive adhesive having an acidic group, tungsten oxide and / or composite tungsten oxide can be uniformly dispersed in the resin in the form of fine particles, whereby the near infrared cut function of (composite) tungsten oxide. Can be fully exhibited. In general, (composite) tungsten oxide is commercially available in a dispersed state, and when the resin having an acidic group of the present invention is not used, it easily aggregates and a uniform dispersed state cannot be obtained. It is difficult to obtain an infrared cut function.

  The compound having the maximum absorption in the wavelength region of 300 to 500 nm is preferably included in any layer.

  The tungsten oxide is an oxide represented by the general formula WyOz (W is tungsten, O is oxygen, 2.2 ≦ z / y ≦ 2.999), and the composite tungsten oxide is the tungsten oxide. The element M (where M 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, 1 or more elements selected from Ta, Re, Be, Hf, Os, Bi, and I). As a result, free electrons are generated in WyOz, including the case of z / y = 3.0, and free electron-derived absorption characteristics are expressed in the near infrared region, which is effective as a near infrared absorbing material near 1000 nm. . In the present invention, composite tungsten oxide is preferable.

In the tungsten oxide fine particles represented by the general formula WyOz (W is tungsten, O is oxygen, 2.2 ≦ z / y ≦ 2.999), the preferable composition range of tungsten and oxygen is When the composition ratio of oxygen is less than 3 and the infrared shielding material is described as WyOz, 2.2 ≦ z / y ≦ 2.999. If the value of z / y is 2.2 or more, it is possible to avoid the appearance of a crystal phase of WO ₂ which is not intended in the infrared shielding material and to obtain chemical stability as a material. Therefore, it can be applied as an effective infrared shielding material. On the other hand, if the value of z / y is 2.999 or less, a required amount of free electrons is generated and an efficient infrared shielding material can be obtained.

  From the viewpoint of stability, the composite tungsten oxide fine particles are generally MxWyOz (where M 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, One or more elements selected from Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, and I, W is tungsten, O is oxygen, (0.001 ≦ x / Y ≦ 1, 2.2 ≦ z / y ≦ 3) The alkali metal is a group 1 element of the periodic table excluding hydrogen, and the alkaline earth metal is the second element of the periodic table. Group elements and rare earth elements are Sc, Y and lanthanoid elements.

  In particular, from the viewpoint of improving optical characteristics and weather resistance as an infrared shielding material, the M element is one or more of Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn. Some are preferred. The composite tungsten oxide is preferably treated with a silane coupling agent. Excellent dispersibility is obtained, and an excellent infrared cut function and transparency are obtained.

  If the value of x / y indicating the added amount of the element M is larger than 0.001, a sufficient amount of free electrons is generated, and a sufficient infrared shielding effect can be obtained. As the amount of the element M added increases, the supply amount of free electrons increases and the infrared shielding effect also increases, but the value of x / y is saturated at about 1. Moreover, if the value of x / y is smaller than 1, it is preferable because an impurity phase can be prevented from being generated in the fine particle-containing layer.

  Regarding the value of z / y indicating the control of the amount of oxygen, in the composite tungsten oxide represented by MxWyOz, the same mechanism as that of the infrared shielding material represented by WyOz described above works, and z / y = Even in 3.0, since there is a supply of free electrons due to the addition amount of the element M described above, 2.2 ≦ z / y ≦ 3.0 is preferable, and 2.45 ≦ z / y ≦ 3.0 is more preferable. It is.

  Further, when the composite tungsten oxide fine particles have a hexagonal crystal structure, the transmission of the fine particles in the visible light region is improved and the absorption in the near infrared region is improved.

When the cation of the element M is added to the hexagonal void, the transmission in the visible light region is improved and the absorption in the near infrared region is improved. Here, generally, when the element M having a large ionic radius is added, the hexagonal crystal is formed. Specifically, Cs, K, Rb, Tl, In, Ba, Sn, Li, Ca, Sr, When Fe is added, hexagonal crystals are easily formed. Of course, other elements may be added as long as the additive element M exists in the hexagonal void formed by the WO ₆ unit, and is not limited to the above elements.

  When the composite tungsten oxide fine particles having a hexagonal crystal structure have a uniform crystal structure, the addition amount of the additive element M is preferably 0.2 or more and 0.5 or less in terms of x / y, and more preferably 0. .33. When the value of x / y is 0.33, it is considered that the additive element M is arranged in all of the hexagonal voids.

  Besides hexagonal crystals, tetragonal and cubic tungsten bronzes also have an infrared shielding effect. These crystal structures tend to change the absorption position in the near infrared region, and the absorption position tends to move to the longer wavelength side in the order of cubic <tetragonal <hexagonal. Further, the accompanying absorption in the visible light region is small in the order of hexagonal crystal <tetragonal crystal <cubic crystal. For this reason, it is preferable to use hexagonal tungsten bronze for applications that transmit light in the visible light region and shield light in the infrared region.

  The particle diameter of the composite tungsten oxide fine particles used in the present invention preferably has a particle diameter (average particle diameter) of 800 nm or less from the viewpoint of maintaining transparency. This is because particles smaller than 800 nm do not completely block light due to scattering, can maintain visibility in the visible light region, and at the same time can efficiently maintain transparency. In particular, when importance is attached to transparency in the visible light region, it is preferable to further consider scattering by particles. When importance is attached to the reduction of scattering by the particles, the particle size is 400 nm or less, preferably 200 nm or less.

  Moreover, it is preferable from the viewpoint of improving weather resistance that the surface of the composite tungsten oxide fine particles of the present invention is coated with an oxide containing one or more of Si, Ti, Zr, and Al.

  The composite tungsten oxide fine particles of the present invention are produced, for example, as follows.

  The tungsten oxide fine particles represented by the general formula WyOz and / or the composite tungsten oxide fine particles represented by MxWyOz are obtained by heat-treating a tungsten compound starting material in an inert gas atmosphere or a reducing gas atmosphere. Can do.

  The tungsten compound starting material is obtained by dissolving tungsten trioxide powder, tungsten oxide hydrate, tungsten hexachloride powder, ammonium tungstate powder, or tungsten hexachloride in alcohol and then drying. Tungsten oxide hydrate powder, or tungsten oxide hydrate powder obtained by dissolving tungsten hexachloride in alcohol and then adding water to precipitate and drying it, or ammonium tungstate It is preferable that it is at least one selected from a tungsten compound powder obtained by drying an aqueous solution and a metal tungsten powder.

  Here, when producing tungsten oxide fine particles, it is preferable to use tungsten oxide hydrate powder or tungsten compound powder obtained by drying an ammonium tungstate aqueous solution from the viewpoint of the ease of the production process. More preferably, when producing the composite tungsten oxide fine particles, an ammonium tungstate aqueous solution or a tungsten hexachloride solution is further used from the viewpoint that each element can be easily and uniformly mixed when the starting material is a solution. preferable. These raw materials are used and heat-treated in an inert gas atmosphere or a reducing gas atmosphere to obtain tungsten oxide fine particles and / or composite tungsten oxide fine particles having the above-mentioned particle diameter.

  The composite tungsten oxide fine particles represented by the general formula MxWyOz containing the element M are the same as the tungsten compound starting material of the tungsten oxide fine particles represented by the general formula WyOz described above. A tungsten compound contained in the form of a simple substance or a compound is used as a starting material. Here, in order to produce a starting material in which each component is uniformly mixed at the molecular level, it is preferable to mix each material with a solution, and the tungsten compound starting material containing the element M is dissolved in a solvent such as water or an organic solvent. Preferably it is possible. Examples thereof include tungstate, chloride, nitrate, sulfate, oxalate, oxide, and the like containing element M, but are not limited to these and are preferably in the form of a solution.

Here, the heat treatment condition in the inert atmosphere is preferably 650 ° C. or higher. The starting material heat-treated at 650 ° C. or higher has sufficient coloring power and is efficient as infrared shielding fine particles. As the inert gas, an inert gas such as Ar or N ₂ is preferably used. As the heat treatment conditions in the reducing atmosphere, first, the starting material is heat-treated at 100 to 650 ° C. in a reducing gas atmosphere, and then heat-treated at a temperature of 650 to 1200 ° C. in an inert gas atmosphere. . The reducing gas at this time is not particularly limited, but H ₂ is preferable. When H ₂ is used as the reducing gas, the volume ratio of H ₂ is preferably 0.1% or more, more preferably 2% or more, as the composition of the reducing atmosphere. If it is 0.1% or more, the reduction can proceed efficiently.

The raw material powder reduced with hydrogen contains a magnetic phase, exhibits good infrared shielding properties, and can be used as infrared shielding particles in this state. However, since hydrogen contained in tungsten oxide is unstable, application may be limited in terms of weather resistance. Therefore, a more stable infrared shielding fine particle can be obtained by heat-treating the tungsten oxide compound containing hydrogen at 650 ° C. or higher in an inert atmosphere. The atmosphere during the heat treatment at 650 ° C. or higher is not particularly limited, but N ₂ and Ar are preferable from an industrial viewpoint. By the heat treatment at 650 ° C. or higher, a Magneli phase is obtained in the infrared shielding fine particles, and the weather resistance is improved.

  The composite tungsten oxide fine particles of the present invention are preferably surface-treated with a coupling agent such as a silane coupling agent, a titanate coupling agent, or an aluminum coupling agent. Silane coupling agents are preferred. Thereby, affinity with binders, such as an intermediate | middle layer, a hard-coat layer, and a heat ray cut layer, becomes favorable, and various physical properties improve other than transparency and heat ray cut property.

  Examples of silane coupling agents include γ-chloropropylmethoxysilane, vinylethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxy. Silane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β -(Aminoethyl) -γ-aminopropyltrimethoxysilane and trimethoxyacrylsilane can be mentioned. Vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, and trimethoxyacrylsilane are preferred. These silane coupling agents may be used alone or in combination of two or more. Moreover, it is preferable to use 5-20 mass parts of content of the said compound with respect to 100 mass parts of microparticles | fine-particles.

  As described above, (composite) tungsten oxide fine particles are generally commercially available in the state of a dispersion (particularly an aqueous dispersion).

  As the pressure-sensitive adhesive (adhesive resin) having an acidic group constituting the near-infrared shielding layer of the present invention, any pressure-sensitive adhesive having an acidic group can be used. Examples of the acidic group include a carboxyl group, a sulfo group, a sulfino group, a phosphoric acid group, a phosphonic acid group, and a sulfuric acid group. A carboxyl group and a sulfo group are preferable, and a carboxyl group is particularly preferable. It is easy to obtain a good dispersion state of the (composite) tungsten oxide fine particles. The acidic group should have an acid value in the adhesive resin so that the acid value of the adhesive is generally 0.5 KOH mg / g or more, preferably 2 to 50 KOH mg / g, and particularly preferably 2 to 20 KOH mg / g. Is appropriate.

  As a kind of resin of an adhesive, what is necessary is just a resin which has an acidic group, For example, synthetic resins, such as an acrylic resin, a polyester resin, a urethane resin, an epoxy resin, a silicon resin, can be mentioned. These resins are preferably used in combination with a curing agent.

  The pressure-sensitive adhesive having an acidic group constituting the near-infrared shielding layer is preferably an acrylic resin-based pressure-sensitive adhesive.

  Examples of the constituent component (monomer) of the preferable acrylic resin include the following compounds.

  Preferred examples of (meth) acrylic acid alkyl esters; (meth) acrylates having in the molecule an optionally branched alkyl group having 1 to 12 carbon atoms, such as methyl (meth) acrylate, ethyl (meth) acrylate, Propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, Nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate can be mentioned ((meth) acrylate means both acrylate and methacrylate). In particular, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are preferable.

  Particularly preferred examples of the (meth) acrylic acid alkoxyalkyl ester include methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate.

  Preferred examples of aromatic ring-containing monomers (copolymerizable compounds containing an aromatic group in the molecular structure) include: phenyl acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, ethylene Examples thereof include oxide-modified nonylphenol (meth) acrylate, hydroxyethylated β-naphthol acrylate, biphenyl (meth) acrylate, styrene, vinyltoluene, α-methylstyrene, and the like. In particular, phenyl acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, and phenoxydiethylene glycol (meth) acrylate are preferable.

  Examples of hydroxyl-containing monomers include: 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) ) Acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, chloro-2-hydroxypropyl acrylate, diethylene glycol mono (meth) acrylate, allyl alcohol and the like. In particular, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable.

  Furthermore, preferable examples of the monomer having a carboxyl group in the molecule include (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, and itacon. Examples thereof include acid, crotonic acid, maleic acid, fumaric acid and maleic anhydride. In particular, (meth) acrylic acid is preferred.

  Preferred examples of the amino group-containing monomer include aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, vinyl pyridine and the like. In particular, dimethylaminoethyl (meth) acrylate is preferable.

  Although the said monomer component is employ | adopted suitably according to the desired physical property, in this invention, it is necessary to use the monomer which has a carboxyl group at least.

  The blend amount of the monomer mixture of the acrylic resin of the present invention is preferably (meth) acrylic acid alkyl ester and / or (meth) acrylic acid alkoxyalkyl ester: 4.5 to 89% by mass (particularly 22.7 to 69% by mass). %), Aromatic ring-containing monomer 10 to 85% by mass (particularly 30 to 70% by mass), hydroxyl group-containing monomer: 1 to 10% by mass (particularly 0.05 to 0.5% by mass), monomer having a carboxyl group: 0 0.05 to 10% by mass (particularly 0.05 to 5% by mass), and amino group-containing monomer 0 to 0.5% by mass (particularly 0 to 0.3% by mass).

  The monomer mixture may be mixed with other monomers as necessary. Examples of other monomers include epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate; acetoacetyl group-containing (meth) acrylates such as acetoacetoxyethyl (meth) acrylate; vinyl acetate, vinyl chloride and ( And (meth) acrylonitrile. The mixing ratio of other monomers can be included at a ratio of 0 to 10% by mass.

  The acrylic resin can be produced by a conventionally known polymerization method such as a solution polymerization method, a bulk polymerization method, an emulsion polymerization method and a suspension polymerization method, but does not contain a polymerization stabilizer such as an emulsifier or a suspending agent. What was manufactured by the polymerization method and the block polymerization method is preferable. Moreover, the weight average molecular weight (Mw) by the gel permeation chromatography (GPC) of the said acrylic polymer is 800,000-1,600,000, Preferably it is 800,000-1,500,000. If the Mw is less than 800,000, the cohesive strength of the pressure-sensitive adhesive is not sufficient even when the curing agent is blended in a suitable range, and foaming tends to occur under high temperature conditions, exceeding 1.6 million. And the stress relaxation property of an adhesive tends to fall. It is preferable that ratio (Mw / Mn) of a weight average molecular weight and a number average molecular weight (Mn) is 10-50. Furthermore, it is suitable that it is 20-50. If the ratio (Mw / Mn) becomes too large, the low molecular weight polymer increases and foaming tends to occur. Conversely, if the ratio (Mw / Mn) becomes too small, the stress relaxation property tends to decrease. .

  The acrylic resin (adhesive) is preferably used together with a curing agent. Examples of the curing agent include an epoxy compound-based crosslinking agent, an isocyanate compound-based crosslinking agent, a metal chelate compound-based crosslinking agent, an aziridine compound-based crosslinking agent, and an amino resin-based crosslinking agent. Among them, an epoxy compound-based crosslinking agent having two or more epoxy groups in the molecule, an isocyanate compound-based crosslinking agent having two or more isocyanate groups in the molecule, and an aziridine compound-based crosslinking agent are preferable. A crosslinking agent is preferred.

  Examples of the epoxy compound-based crosslinking agent having two or more epoxy groups in the molecule include 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-m— Xylylenediamine, N, N, N ′, N′-tetraglycidylaminophenylmethane, triglycidyl isocyanurate, m-N, N-diglycidylaminophenyl glycidyl ether, N, N-diglycidyl toluidine, N, N -Compounds having two or more epoxy groups such as diglycidyl aniline, pentaerythritol polyglycidyl ether, 1,6-hexanediol diglycidyl ether are preferred.

  Examples of isocyanate compounds include isocyanate monomers such as tolylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like. Isocyanate compounds obtained by adding these isocyanate monomers with trimethylolpropane, isocyanurates, burette type compounds, and urethane prepolymer type products such as polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, etc. An isocyanate etc. can be mentioned.

  Further, examples of the aziridine compound-based crosslinking agent include trimethylolpropane tri-β-aziridinylpropionate, trimethylolpropane tri-β- (2-methylaziridine) propionate, tetramethylolmethanetri-β-aziridinini. Examples include lupropionate and triethylenemelamine.

  The amount of the crosslinking agent is preferably 0.0001 to 2.0 parts by weight with respect to 100 parts by weight of the acrylic resin.

  The pressure-sensitive adhesive composition containing an acrylic resin preferably used in the present invention is an ultraviolet absorber, an antioxidant, an antiseptic and an antifungal agent as long as the transparency, visibility and the effects of the present invention are not impaired. , Tackifier resins, plasticizers, antifoaming agents, wettability adjusting agents and the like may be blended.

  The near-infrared shielding layer is a layer mainly composed of the above tungsten oxide or composite tungsten oxide and a resin having an acidic group (preferably the above acrylic resin). The near-infrared shielding layer is obtained, for example, by coating, drying, and curing, if necessary, a coating solution containing the above (composite) tungsten oxide and a binder resin. Alternatively, it can also be obtained by applying a coating liquid containing the above (composite) tungsten oxide and a binder resin and simply drying it. When used as a film, it is generally a near infrared cut film, for example, a film containing (composite) tungsten oxide.

  In addition to the (composite) tungsten oxide, a dye may be used if necessary. The dye generally has an absorption maximum at a wavelength of 800 to 1200 nm. Examples include phthalocyanine dyes, metal complex dyes, nickel dithiolene complex dyes, cyanine dyes, squarylium dyes, polymethine dyes, Examples thereof include azomethine dyes, azo dyes, polyazo dyes, diimonium dyes, aminium dyes, and anthraquinone dyes, and cyanine dyes, phthalocyanine dyes, and diimonium dyes are particularly preferable. These dyes can be used alone or in combination. The near-infrared shielding layer is preferably an adhesive layer, and examples of the adhesive resin include thermoplastic resins such as acrylic resins.

  The near-infrared shielding layer preferably contains 0.1 to 20 parts by mass, more preferably 1 to 20 parts by mass, and particularly preferably 1 to 10 parts by mass of the (composite) tungsten oxide with respect to 100 parts by mass of the binder resin. The thickness of the near infrared shielding layer is generally 1 to 50 μm, preferably 5 to 50 μm.

  In the present invention, the near-infrared shielding layer may be provided with a function of adjusting the color tone by providing an absorption function of neon light emission. For this purpose, a neon-emission absorbing layer may be provided, but the near-infrared shielding layer may contain a neon-emission selective absorption dye. It is preferable to provide a pressure-sensitive adhesive layer having a function of absorbing neon light emission.

  Neon luminescent selective absorption dyes include cyanine dyes, squarylium dyes, anthraquinone dyes, phthalocyanine dyes, polymethine dyes, polyazo dyes, azurenium dyes, diphenylmethane dyes, and triphenylmethane dyes. it can. Such a selective absorption dye is required to have a selective absorption of neon emission near 585 nm and a small absorption at other visible light wavelengths, so that the absorption maximum wavelength is 575 to 595 nm and the absorption spectrum half width is What is 40 nm or less is preferable.

  Further, as long as the optical properties are not greatly affected, coloring pigments, ultraviolet absorbers, antioxidants and the like may be further added.

  The layer containing the compound (dye or pigment) is 0.1 to 20 parts by mass, more preferably 1 to 20 parts by mass, and particularly 1 to 10 parts by mass with respect to 100 parts by mass of the compound as a binder resin (resin for adhesive). It is preferable to contain a part. The thickness of such a layer is generally 1 to 50 μm, preferably 5 to 50 μm.

  The above-mentioned or normal pressure-sensitive adhesive layer is mainly a layer for adhering the optical film of the present invention to a display, and any resin having an adhesive function can be used. For example, acrylic adhesives, rubber adhesives, SEBS (styrene / ethylene / butylene / styrene) and SBS (styrene / butadiene / styrene) and other thermoplastic elastomers (TPE) as main components TPE-based pressure-sensitive adhesives and adhesives can also be used.

  The layer thickness is generally in the range of 5 to 500 μm, particularly 10 to 100 μm. In general, the optical filter can be equipped by pressing the pressure-sensitive adhesive layer on a glass plate of a display.

  As the near-infrared absorption characteristics of the optical filter of the present invention, the minimum value of the transmittance in the near-infrared wavelength range of 800 to 1100 nm is preferably 30% or less, particularly preferably 20% or less. As a result, there is an effect of reducing the transmittance in the wavelength region where malfunction of a peripheral device remote controller or the like is pointed out.

Further, as described above, it is preferable for the light transmitted through the optical filter L ^* a ^* b ^* display system of b ^* is -15 or more.

  When two transparent substrates are used in the present invention, these adhesions (adhesive layer) include, for example, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, acrylic resin (eg, ethylene- ( (Meth) acrylic acid copolymer, ethylene- (meth) ethyl acrylate copolymer, ethylene- (meth) methyl acrylate copolymer, metal ion crosslinked ethylene- (meth) acrylic acid copolymer), partially saponified ethylene -Ethylene copolymers such as vinyl acetate copolymer, carboxylated ethylene-vinyl acetate copolymer, ethylene- (meth) acryl-maleic anhydride copolymer, ethylene-vinyl acetate- (meth) acrylate copolymer ("(Meth) acryl" indicates "acryl or methacryl"). In addition, polyvinyl butyral (PVB) resin, epoxy resin, phenol resin, silicon resin, polyester resin, urethane resin, rubber adhesive, thermoplastic elastomers such as SEBS and SBS can be used, but good adhesion Acrylic resin adhesives and epoxy resins are easily obtained.

  The layer thickness is preferably in the range of 10 to 100 μm. In general, the optical filter can be equipped by pressing the pressure-sensitive adhesive layer on a glass plate of a display.

  When EVA is also used as the material for the pressure-sensitive adhesive layer, the EVA has a vinyl acetate content of 5 to 50% by mass, preferably 15 to 40% by mass. When the vinyl acetate content is less than 5% by mass, there is a problem in transparency, and when it exceeds 40% by mass, the mechanical properties are remarkably deteriorated and the film formation becomes difficult and the films tend to block each other.

  As the cross-linking agent, an organic peroxide is suitable for heat cross-linking and is selected in consideration of sheet processing temperature, cross-linking temperature, storage stability, and the like. The organic peroxide is usually kneaded with EVA using an extruder, a roll mill or the like, but may be dissolved in an organic solvent, a plasticizer, a vinyl monomer or the like and added to the EVA film by an impregnation method.

  The pressure-sensitive adhesive layer for the above-mentioned adhesion is, for example, a mixture of EVA and the above-mentioned additives, kneaded with an extruder, roll, etc., and then formed into a predetermined shape by a film forming method such as calendar, roll, T-die extrusion, inflation, etc. It is manufactured by forming a sheet.

  A protective layer may be provided on the antireflection layer. The protective layer is preferably formed in the same manner as the hard coat layer.

  As the material of the release sheet provided on the pressure-sensitive adhesive layer, a transparent polymer having a glass transition temperature of 50 ° C. or higher is preferable. Examples of such a material include polyesters such as polyethylene terephthalate, polycyclohexylene terephthalate, and polyethylene naphthalate. In addition to resins, nylon 46, modified nylon 6T, nylon MXD6, polyamide resins such as polyphthalamide, ketone resins such as polyphenylene sulfide and polythioether sulfone, and sulfone resins such as polysulfone and polyether sulfone. Mainly composed of polymers such as ether nitrile, polyarylate, polyetherimide, polyamideimide, polycarbonate, polymethyl methacrylate, triacetyl cellulose, polystyrene, polyvinyl chloride It can be used fat. Of these, polycarbonate, polymethyl methacrylate, polyvinyl chloride, polystyrene, and polyethylene terephthalate can be suitably used. The thickness is preferably 10 to 200 μm, particularly preferably 30 to 100 μm.

  FIG. 6 shows an example of a state where the optical filter of the present invention is affixed to the image display surface of a plasma display panel, which is a kind of display. An optical filter is bonded to the surface of the display surface of the display panel 60 via an adhesive layer 65. That is, the mesh-like conductive layer 64, the hard coat layer 62A, and the low refractive index layer 62B are provided in this order on one surface of the transparent substrate 61, and the near-infrared shielding layer 63 and the transparent layer are provided on the other surface of the transparent substrate 61. An optical filter provided with an adhesive layer 65 is provided on the display surface. The mesh-like conductive layer 64 'is exposed at the edge (side edge) of the filter (for example, obtained by removing each layer at the end with a laser). The exposed mesh-like conductive layer 64 ′ is brought into contact with a metal cover 69 provided around the plasma display panel 60 via a shield finger (plate spring-like metal part) 68. A conductive gasket or the like may be used instead of the shield finger (plate spring-like metal part). As a result, the optical filter and the metal cover 69 are brought into conduction, and grounding is achieved. The metal cover 69 may be a metal frame or a frame. As apparent from FIG. 6, the mesh-like conductive layer 64 faces the viewer side.

  Since the PDP display of the present invention generally uses a plastic film as the transparent substrate, the optical filter of the present invention can be directly bonded to the surface of the glass plate as described above. When one sheet is used, the PDP itself can contribute to weight reduction, thickness reduction, and cost reduction. Compared with the case where a front plate made of a transparent molded body is installed on the front side of the PDP, an air layer having a low refractive index can be eliminated between the PDP and the PDP filter, so that visible light reflection due to interface reflection can be achieved. Problems such as an increase in rate and double reflection can be solved, and the visibility of the PDP can be further improved.

  The near-infrared shielding body of the present invention has at least the near-infrared shielding layer described above, and may further have a functional layer such as a transparent substrate, an adhesive layer, or an antireflection layer, if necessary. good.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to a following example.

[Example 1]
<Preparation of optical filter for display>
(Preparation of film with near-infrared shielding layer)
On a PET film (thickness: 188 μm, A4300; manufactured by Toyobo Co., Ltd.), a coating solution for forming an adhesive near infrared shielding layer having the following composition was applied using an applicator so that the thickness would be 25 μm after drying. And dried in an oven at 80 ° C. for 2 minutes. This produced the optical filter for displays which has an adhesive near-infrared shielding layer (thickness 25 micrometers) on PET film.

(Composition of the coating liquid for forming the adhesive near-infrared shielding layer)
Acrylic resin adhesive (trade name: SK Dyne 1501BS4, manufactured by Soken Chemical Co., Ltd.,
Acid value: 4.7 KOHmg / g, solid content 20% by mass, ethyl acetate solution) 100 parts by mass Epoxy curing agent (trade name L-45, manufactured by Soken Chemical Co., Ltd.) 1 part by mass Cs _0.33 WO ₃
(Average particle diameter 80 nm, solid content 20 mass%, MIBK solution) 5 mass parts Thereby, the film (optical filter) which has a near-infrared shielding layer was obtained.

[Comparative Example 1]
<Preparation of optical filter for display>
An optical filter for display was obtained in the same manner as in Example 1 except that the following coating liquid for forming an adhesive near-infrared shielding layer was used.

(Composition of the coating liquid for forming the adhesive near-infrared shielding layer)
Acrylic adhesive (trade name SK Dyne 1811L, manufactured by Soken Chemical Co., Ltd.,
Acid value: 0.0 KOHmg / g, solid content 20% by mass, ethyl acetate solution) 100 parts by mass Epoxy curing agent (trade name L-45, manufactured by Soken Chemical Co., Ltd.) 1 part by mass Cs _0.33 WO ₃
(Average particle size 80 nm, solid content 20% by weight, MIBK solution) 5 parts by weight In addition, when an acrylic adhesive and Cs _0.33 WO ₃ dispersion were mixed, they became cloudy but were used as they were to produce an optical filter for display. did.

[Example 2]
<Preparation of film with mesh conductive layer>
A copper foil was laminated on one surface of a PET film (thickness: 100 μm) via an adhesive layer, and then the copper foil was etched by a photolithography method. Thereby, a film having a mesh-like conductive layer (average height 10 μm, average width 20 μm, pitch 250 μm, aperture ratio 85%) was obtained.

<Preparation of substrate with near-infrared shielding layer>
On the other surface of the PET film, a coating solution for forming an adhesive near-infrared shielding layer having the following composition was applied using an applicator so as to have a thickness of 25 μm after drying, and in an oven at 80 ° C. And dried for 2 minutes. Thus, the PET film having a mesh-like conductive layer laminated on one surface via an adhesive layer and an adhesive near-infrared shielding layer (thickness 25 μm) on the other surface (FIG. 4). ) Was produced.

(Coating liquid for forming adhesive near-infrared shielding layer)
Acrylic resin adhesive (trade name: SK Dyne 1501BS4, manufactured by Soken Chemical Co., Ltd.,
Acid value: 4.7 KOHmg / g, solid content 20% by mass, ethyl acetate solution) 100 parts by mass Epoxy curing agent (trade name L-45, manufactured by Soken Chemical Co., Ltd.) 1 part by mass Cs _0.33 WO ₃
(Average particle size 80 nm, solid content 20% by mass, MIBK solution) 5 parts by mass <Preparation of optical filter for display>
On the float glass (thickness 2.5 mm), the upper PET film was placed so that the near-infrared shielding layer and the float glass face each other, and these were pressure-bonded.

[Example 3]
<Preparation of film with mesh conductive layer>
In the same manner as in Example 2, a film having a mesh-like conductive layer (average height 10 μm, average width 20 μm, pitch 250 μm, aperture ratio 85%) was obtained.

<Preparation of substrate with near-infrared shielding layer>
An adhesive near-infrared shielding layer (thickness 25 μm) was produced in the same manner as in Example 2, except that the adhesive liquid for forming an adhesive near-infrared shielding layer was applied onto the mesh-shaped conductive layer produced above. . Thereby, the PET having a mesh-like conductive layer laminated on one surface via an adhesive layer, and an adhesive near-infrared shielding layer (thickness 25 μm) laminated on the mesh-like conductive layer A film (FIG. 5) was produced.

<Preparation of optical filter for display>
On the float glass (thickness 2.5 mm), the upper PET film was placed so that the near-infrared shielding layer and the float glass face each other, and these were pressure-bonded.

[Comparative Example 2]
In Example 2, an optical filter for display was obtained in the same manner except that the following coating liquid for forming an adhesive near-infrared shielding layer was used.

(Composition of the coating liquid for forming the adhesive near-infrared shielding layer)
Acrylic adhesive (trade name SK Dyne 1811L, manufactured by Soken Chemical Co., Ltd.,
Acid value: 0.0 KOHmg / g, solid content 20% by mass, ethyl acetate solution) 100 parts by mass Epoxy curing agent (trade name L-45, manufactured by Soken Chemical Co., Ltd.) 1 part by mass Cs _0.33 WO ₃
(Average particle size 80 nm, solid content 20% by mass, MIBK solution) 5 parts by mass In addition, when the acrylic adhesive and Cs _0.33 WO ₃ dispersion were mixed, they became cloudy but were used as they were to produce an optical filter for display. did.

[Evaluation of optical filter]
(1) Luminous transmittance The luminous transmittance (JIS-Z-8105-1982) of the optical filters obtained in Examples and Comparative Examples was measured with a spectrophotometer UV3100PC (manufactured by Shimadzu Corporation). .
(2) Minimum value of transmittance of near infrared light of 800 to 1100 nm For the optical filters obtained in Examples and Comparative Examples, the minimum value of transmittance of near infrared light was measured using a spectrophotometer UV3100PC (Shimadzu Corporation). Manufactured).
(3) Haze Fully automatic direct reading haze computer HGM-2DP (manufactured by Suga Test Instruments Co., Ltd.) according to the method of JIS-K-7105 (1981), using the haze values of the optical filters obtained in Examples and Comparative Examples. It measured using.

  The results are shown in Tables 1 and 2.

The optical filter for display obtained in Example 1 has a high total light transmittance, a low haze, and excellent transparency, while an effective near-infrared cut because the minimum value of the transmittance of 800 to 1100 nm is low. Indicates the function. This is considered because Cs _0.33 WO ₃ particles are finely and uniformly dispersed. On the other hand, the display optical filter obtained in Comparative Example 1 has a low total light transmittance and a high haze, so that the transparency is not sufficient, and the minimum value of the transmittance of 800 to 1100 nm is high. The cutting function is not satisfactory. This is considered because Cs _0.33 WO ₃ particles are not uniformly dispersed. Similar results were obtained in Examples 2 and 3 and Comparative Example 2.

11, 21A, 21B, 31 Transparent substrate 41A, 41B, 51A, 51B, 61 Transparent substrate 12, 22, 32, 62 Antireflection layer 13, 23, 33, 43, 53, 63 Near infrared shielding layer 14, 24, 34 , 44, 54, 64 Conductive layer 25, 35, 65 Adhesive layer 46, 56 Adhesive layer

Claims (16)

  The near-infrared shielding body characterized by including the adhesive which has a tungsten oxide and / or composite tungsten oxide, and an acidic group.   The near-infrared shielding body according to claim 1, wherein the acid value of the adhesive is 0.5 KOHmg / g or more.   The near-infrared shielding body according to claim 1 or 2, wherein the pressure-sensitive adhesive is an acrylic resin-based pressure-sensitive adhesive.   The near-infrared shielding body according to claim 1, wherein the acidic group of the pressure-sensitive adhesive is a carboxyl group.   The near-infrared shielding body according to any one of claims 1 to 4, wherein the tungsten oxide and / or the composite tungsten oxide is in the form of fine particles.   The near-infrared shield according to claim 5, wherein the average particle size of the fine particles is 400 nm or less. Tungsten oxide is represented by the general formula WyOz (where W is tungsten, O represents oxygen and 2.2 ≦ z / y ≦ 2.999), and the composite tungsten oxide is represented by the general formula MxWyOz. (However, M 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 One or more elements selected from Hf, Os, Bi, and I, W represents tungsten, O represents oxygen, and 0.001 ≦ x / y ≦ 1, 2.2 ≦ z / y ≦ 3 The near red according to any one of claims 1 to 6 represented by Line shield.   Furthermore, the near-infrared shielding body of any one of Claims 1-7 containing a hardening | curing agent.   The near-infrared shield according to any one of claims 1 to 8, wherein a minimum value of light transmittance in a wavelength region of 800 to 1100 nm is 30% or less.   An optical filter for display comprising a near-infrared shielding layer, wherein the near-infrared shielding layer contains a tungsten oxide and / or a composite tungsten oxide and an adhesive having an acidic group.   The optical filter for display according to claim 10, wherein the near-infrared shielding layer further contains a curing agent.   The optical filter for display according to 10 or 11, further comprising at least one other functional layer. A display optical filter in which a conductive layer and an antireflection layer are provided in this order on one surface of a substrate, and a near-infrared shielding layer is provided on the other surface of the substrate,
An optical filter for display, wherein the near-infrared shielding layer contains tungsten oxide and / or composite tungsten oxide and an adhesive having an acidic group.   The optical filter for display according to claim 13, wherein the near-infrared shielding layer further contains a curing agent.   Furthermore, the optical filter for displays of Claim 13 containing an adhesive layer. It is a filter for plasma display panels, The optical filter for displays of any one of Claims 10-15.

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