JP2008083647A - Optical filter for display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical filter that can be inexpensively manufactured while maintaining an excellent electromagnetic wave shielding effect and a near IR ray shielding effect. <P>SOLUTION: In the optical filter 10 for a display to be disposed on a front face P of a display, the structural layers of the filter include an electromagnetic wave shielding layer 15, an NIR reflecting agent dispersion layer 17 prepared by dispersing a near IR ray reflecting agent in a transparent resin layer, and an NIR absorbing pigment dispersion layer 16 prepared by dispersing a near IR ray absorbing pigment in a tacky adhesive layer. Thereby, the optical filter can be inexpensively manufactured by reducing the use amount of the near IR ray absorbing pigment while maintaining an excellent electromagnetic wave shielding effect and a near IR ray shielding effect. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an optical filter used for various displays such as a CRT and a PDP (plasma display), and an optical that can be manufactured at low cost while maintaining a particularly excellent electromagnetic shielding effect and a near infrared shielding effect. Regarding filters.
In the present invention, “near infrared (NIR)” means light having a wavelength of 800 to 1100 nm.

  In recent years, in displays such as a plasma display panel (PDP), electromagnetic waves generated from the front of the display have a bad influence on the human body and malfunction of surrounding electronic devices has become a problem. At the same time, countermeasures against the influence of the display on the surrounding area are becoming more important.

In particular, in PDPs where demand is increasing as large thin displays, in addition to electromagnetic wave shielding films, near-infrared absorbing films for preventing malfunctions of various remote control switches using the near-infrared wavelength region, UV light absorbing film used to prevent near-infrared absorbers used for near-infrared absorbing film over time, neon light cut film for adjusting color tone in the visible light region, and external light reflected on the surface of optical filters An antireflection film or the like for preventing this is combined and configured according to the required function.
By using these films as optical filters for displays, measures are taken to improve the image appearance and to reduce the influence on the surroundings.

  Conventionally, various transparent conductive films and electromagnetic wave shielding films have been developed in response to the requirement to prevent the electromagnetic waves generated from the display from leaking to the outside and adversely affecting the human body. Known electromagnetic shielding materials can be broadly classified into two types: an electromagnetic shielding material made of a transparent conductive film and an electromagnetic shielding material made of a conductive metal mesh. Among these, the electromagnetic shielding material using a transparent conductive film is superior in transparency to the electromagnetic shielding material using a metal mesh, but has a large surface resistivity and inferior electromagnetic shielding performance. For this reason, in the use which shields the electromagnetic waves from the apparatus which generate | occur | produces strong electromagnetic waves, such as PDP, the electromagnetic wave shielding material by a metal mesh is preferable.

  Further, as a method for producing an electromagnetic wave shielding material using a conductive metal mesh, (1) a metal foil is bonded to a transparent substrate, or a metal thin film is deposited on the transparent substrate, and then a conductive metal is obtained by a photolithographic method. An etching method for forming a pattern (for example, refer to Patent Document 1), and (2) a thin metal pattern formed with developed silver produced by a photographic method, and then plated on the developed silver thin film to form a conductive metal Examples thereof include a photographic silver-plating method for forming a pattern (see, for example, Patent Document 2).

On the other hand, as a near-infrared absorbing film, a near-infrared absorbing filter in which a near-infrared absorbing layer made of a near-infrared absorbing composition made of a dithiol nickel compound and / or a diimmonium compound is formed on one side of a transparent substrate is disclosed ( (See Patent Document 3).
Also disclosed is a near-infrared absorbing film having at least two near-infrared absorbing layers each absorbing in the near-infrared region between wavelengths of 800 to 1100 nm, and comprising at least three layers including a substrate. (See Patent Document 4).
Furthermore, a near-infrared absorption filter formed by laminating a composition in which a near-infrared absorption pigment is dispersed in a binder resin on a substrate is disclosed (see Patent Document 5).

As for the entire optical filter, for example, Patent Document 6 discloses a neon light cut layer (absorption wavelength: 580 to 620 nm) for color correction, an antireflection film for preventing reflection of external light, and neon by external light. A filter for plasma display having an adhesive layer containing an ultraviolet absorber for preventing deterioration of the light-cutting dye and sputtered glass having electromagnetic wave shielding ability is disclosed.
Patent Document 7 discloses an optical filter having an electromagnetic shielding property and a near-infrared cutting property by a transparent conductive film having a structure in which metal thin film layers and high refractive index transparent thin film layers are alternately laminated.
Patent Document 8 discloses an optical filter for plasma display in which a metal mesh having electromagnetic wave shielding properties, an infrared absorber-containing adhesive layer having infrared absorbing ability, an antireflection layer, and a neon light absorbing layer are laminated. Yes.
In Patent Document 9, in order to reduce the cost of a near-infrared absorbing dye, a multilayer film that selectively reflects near infrared rays in which a plurality of dielectrics having different refractive indexes are laminated, and a dye layer that selectively absorbs near infrared rays Is disclosed.
Japanese Patent Laid-Open No. 10-075087 International Publication No. 2004/007810 Pamphlet JP 2005-054031 A JP 2002-156521 A JP 2000-227515 A JP 2004-325532 A Japanese Patent Laid-Open No. 10-217380 JP 2004-333743 A JP 2006-098749 A

  In the prior art, there has been a demand for an optical filter that avoids an increase in price and weight due to an increase in the size of the screen of a PDP (plasma display panel), and further reduces the weight and costs. Another problem is to reduce costs while maintaining an excellent electromagnetic shielding effect and near infrared shielding effect.

  Each of the near-infrared absorbing films incorporated in the optical filters described in Patent Documents 3 to 5 is obtained by laminating a near-infrared absorbing layer containing a near-infrared absorbing pigment on one side of a transparent substrate. However, the near-infrared shielding effect of these optical filters depends on the content of the near-infrared absorbing dye, and since an expensive near-infrared absorbing dye is used, the cost can be reduced while maintaining the near-infrared shielding effect. There was a problem that could not.

  The optical filter described in Patent Document 9 uses a near-infrared absorbing dye that is used in combination by using a multilayer film in which a plurality of dielectrics having different refractive indexes are laminated to selectively reflect and attenuate near-infrared rays. The amount is reduced and the price is low. However, although the performance of the multilayer film is increased by increasing the number of layers, there has been a problem that the manufacturing cost, the layer thickness, and the weight of the optical filter increase as the number of layers increases.

  Thus, in the prior art, the near-infrared reflector (A) made of metal oxide fine particles and the near-infrared absorbing dye (B) are used in combination to maintain an excellent electromagnetic wave shielding effect and near-infrared shielding effect. However, an optical filter that can be manufactured at low cost has not been provided.

  This invention is made | formed in view of the said situation, By using together the near-infrared reflector (A) which consists of metal oxide microparticles | fine-particles, and a near-infrared absorption pigment | dye (B), it is excellent in the electromagnetic wave shielding effect. It is an object to provide an optical filter that can be manufactured at low cost while maintaining the near-infrared shielding effect.

  In order to solve the above-described problems, the present invention provides an optical filter for display provided on the front surface of a display, and a near-infrared reflector (A) comprising an electromagnetic wave shielding layer and metal oxide fine particles in a constituent layer of the optical filter. ) Is dispersed in the transparent resin layer and / or the pressure-sensitive adhesive layer, and the NIR absorbing dye is formed by dispersing the near-infrared absorbing dye (B) in the transparent resin layer and / or the pressure-sensitive adhesive layer. And an optical filter for display, comprising: a dispersion layer.

In addition, the near-infrared reflector (A) is natural mica or synthetic mica coated with ruthenium oxide, titanium oxide, iron oxide, titanium oxide and / or iron oxide at a coverage of 10% or more, zinc oxide, zirconium oxide. It is preferable that it is 1 or more types selected from the metal oxide group which consists of aluminum oxide.
The near-infrared absorbing dye (B) is composed of two types of absorbing dye for long wavelength and absorbing dye for short wavelength each having a maximum absorption capacity in different wavelength bands in the absorption wavelength band of 850 nm to 1100 nm. The near-infrared absorbing dye for long wavelengths is one selected from diimmonium salt compounds, and the near-infrared absorbing dye for short wavelengths is a phthalocyanine compound, cyanine compound, thiol nickel complex salt One or more dyes selected from the compounds are preferred.

  It is preferable that the transmittance for near infrared rays having a wavelength of 800 nm to 1100 nm by the NIR reflector dispersion layer and the NIR absorbing dye dispersion layer is 20% or less. More preferably, it is 10% or less.

The electromagnetic wave shielding layer is preferably made of a conductive metal mesh.
The electromagnetic wave shielding layer is preferably a conductive metal mesh in which a fine line pattern is formed by electroless plating and / or electrolytic plating of a metal using physically developed metallic silver as a catalyst core.

The optical filter preferably has one or more layers among an ultraviolet absorption layer, a neon light absorption layer, an antireflection layer, and an antiglare layer.
The display is preferably a plasma display.

  According to the optical filter for display of the present invention, the image light from the display is relatively well transmitted in the visible light region due to the function of the near-infrared reflector (A) in the NIR reflector dispersion layer. Light in the outer region is reflected and attenuated.

Next, attenuated near-infrared light is absorbed by the NIR absorbing dye dispersion layer, so that the amount of near-infrared absorbing dye (B) used can be reduced, and an optical filter can be manufactured at low cost. .
Further, the NIR reflector dispersion layer and the NIR absorbing dye dispersion layer are composed of two transparent resin layers and / or pressure-sensitive adhesive layers, and a significant increase in the thickness and weight of the optical filter can be avoided.

  Thus, in the present invention, by using the near-infrared reflector (A) made of metal oxide fine particles and the near-infrared absorbing dye (B) in combination, an excellent electromagnetic shielding effect and a near-infrared shielding effect can be obtained. It is possible to obtain an optical filter that can be manufactured at low cost while being maintained.

The display optical filter of the present invention (hereinafter sometimes simply referred to as “optical filter”) will be described in detail below based on the best mode.
FIG. 1 is a schematic cross-sectional view showing an example of the layer configuration of the optical filter of the present invention. FIG. 2 is a schematic cross-sectional view showing another example of the layer configuration of the optical filter of the present invention. These optical filters can be used by being directly attached to a front panel P of a display such as a plasma display panel (PDP). 1 and 2, the eye E represents the visual side.

In the optical filter 10 shown in FIG. 1, an antireflection layer 11, a transparent base material 12, an adhesive layer 13, a transparent base material 14, an electromagnetic wave shielding layer 15, and a near-infrared absorbing dye (B) are added in order from the visual side. A pressure-sensitive adhesive layer (NIR absorbing dye dispersion layer) 16, a transparent resin layer (NIR reflector dispersion layer) 17 to which a near-infrared reflective agent (A) is added, and a pressure-sensitive adhesive layer 18 are laminated.
The optical filter 20 shown in FIG. 2 includes, in order from the visual side, an antireflection layer 21, a transparent base material 22, an adhesive layer 23, a transparent base material 24, an electromagnetic wave shielding layer 25, an adhesive layer 26, a near-infrared absorbing dye (B ) Added transparent resin layer (NIR absorbing dye dispersion layer) 28, adhesive layer 29, transparent resin layer (NIR reflector dispersion layer) 27 added with near infrared reflector (A), and adhesive layer 19 It is a layered product.

In the case of the optical filters 10 and 20 shown in FIGS. 1 and 2, both the NIR reflector dispersion layer and the NIR absorbing dye dispersion layer function as a near-infrared shielding layer.
In FIG. 1, a near-infrared absorbing dye (B) is added to the pressure-sensitive adhesive layer 16 in contact with the electromagnetic wave shielding layer 15 to form a NIR absorbing dye-dispersed layer, and a near-infrared reflecting agent (A) is added to the transparent resin layer 17. Is added to the transparent resin layers 27 and 28 through the pressure-sensitive adhesive layer 26 in contact with the electromagnetic wave shielding layer 25, respectively. Although the example which added the near-infrared absorption pigment | dye (B) and became the NIR reflector dispersion layer and the NIR absorption pigment | dye dispersion layer is shown, this invention is not limited to this illustration.
Moreover, the combination of the layers employ | adopted for an optical filter among an ultraviolet-ray absorption layer, a neon light absorption layer, and an antireflection layer is not limited to said illustration. A neon light absorption layer (not shown) can be realized, for example, by an adhesive layer to which a neon light absorber is added.

(Antireflection layer)
Here, the antireflection layers 11 and 21 are for preventing reflection of visible light from the outside of the optical filters 10 and 20. In the case of a single layer, the refractive index is lower than that of the transparent base materials 12 and 22. A thin film such as a fluorine-containing organic compound having a low substance, for example, a polysiloxane structure is formed. In the case of a multi-layer structure, a material having a higher refractive index than that of the transparent substrates 12 and 22, such as a vapor-deposited thin film of titanium oxide, and a material having a lower refractive index than that of the transparent substrate, such as a thin film of silicon oxide are alternately provided Laminate. The formation method of such a metal oxide thin film is not particularly limited, and a thin film of zirconium oxide, ITO, silicon oxide, or the like can be formed by a sputtering method, a vacuum evaporation method, or a wet coating method.
However, in the case of an optical filter for display, since a plurality of films are laminated, reflection occurs at the laminated film interface. For this reason, since the reflectance of the entire optical filter increases, only the outermost antireflection layers 11 and 21 prevent the whitening of the image and the decrease in black-and-white contrast due to the reflection of external light, thereby clearing the image. The current situation is that we have not been able to solve the problem of making it.

  Therefore, a light absorbing material that absorbs external light that has passed through the antireflection layers 11 and 21 is dispersed in the pressure-sensitive adhesive layers 13 and 23 or the transparent base materials 12 and 22 so that external light enters the optical filters 10 and 20. Then, the scattered light derived from the external light incident on the optical filters 10 and 20 is emitted to the outside of the filter again, or becomes stray light and interferes with the image on the display, thereby reducing the whitening of the image. It is possible to prevent the display image from being whitened by the incidence of external light and stray light, and to increase the black-and-white contrast. In addition, from the viewpoint of suppressing whitening due to stray light, the layer in which the light absorbing material is dispersed is preferably located on the outer side (visual side) as much as possible.

As the light absorbing material used in the present invention, particles of black pigments such as carbon black, graphite, aniline black, cyanine black, titanium black, black iron oxide, chromium oxide, and manganese oxide can be used. These black pigments can be used alone or in combination of two or more. Among the black pigments, carbon black is particularly preferably used. The preferable particle size distribution range of the black pigment (light absorbing material) is in the range of 0.01 to 0.5 μm, and more preferably in the range of 0.05 to 0.3 μm. In addition, in order to adjust the color tone of the entire optical filter to an achromatic color or a preferable color tone, a plurality of other color materials may be used as necessary.
Increasing the amount of black pigment (light absorber) added to increase black and white contrast causes the phenomenon that the total light transmittance decreases and the image becomes dark, so the amount of black pigment (light absorber) added is unlimited. However, it is possible to achieve sufficiently satisfactory black and white contrast by adjusting the addition condition of the black pigment (light absorbing material) according to the allowable total light transmittance.

(Transparent substrate)
As a transparent material constituting each transparent base material 12, 14, 17, 22, 24, 27, 28, a plastic made of a resin that is transparent in the visible region, has flexibility, and preferably has good heat resistance. It is a film. Examples of such films include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), diacetate resins, triacetate resins, acrylic resins, polycarbonate resins, triacetyl cellulose, polystyrene, polyolefins, polyurethane resins, Examples thereof include a single layer or a composite film having a thickness of 10 to 600 μm made of polyvinyl chloride, polyimide resin, polyamide resin or the like. Each transparent substrate is coated with a functional layer such as an antireflection layer, an electromagnetic wave shielding layer, an ultraviolet absorption layer, a neon light absorption layer, and a near infrared reflector and / or a near infrared absorption pigment is mixed in as it is. Present in the construction of the filter to be laminated. From the viewpoint of suppressing the decrease in the total light transmittance, it is preferable to reduce the number of transparent base layers as much as possible. As such a combined method, a method of sequentially forming a plurality of functional layers on one transparent substrate or transferring a functional layer formed on a release paper can be mentioned.

(Adhesive layer)
The pressure-sensitive adhesive constituting each pressure-sensitive adhesive layer 13, 16, 18, 19, 23, 26, 29 is not particularly limited as long as it is transparent in the visible region (that is, has sufficient transmittance). , Rubber adhesives, acrylic adhesives, silicone adhesives and the like may be used, but acrylic adhesives are particularly preferable. Thereby, it is excellent in transparency and the weather resistance of the adhesive layers 13, 16, 18, 19, 23, 26, 29 can be maintained well.
Examples of such an acrylic pressure-sensitive adhesive component include a low-Tg main monomer that provides tackiness, a high-Tg comonomer that provides adhesion and cohesion, and a functional group for improving crosslinking and adhesion. Those composed of a group-containing monomer (monoethylenically unsaturated monomer) and the like are used.
Examples of the main monomer include alkyl acrylates such as ethyl acrylate, butyl acrylate, amyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, cyclohexyl acrylate, benzyl acrylate, butyl methacrylate, and methacrylic acid. Examples thereof include methacrylic acid alkyl esters such as 2-ethylhexyl, cyclohexyl methacrylate and benzyl methacrylate, and these can be used alone or in combination of two or more.
Examples of the comonomer include vinyl group-containing compounds such as methyl acrylate, methyl methacrylate, ethyl methacrylate, vinyl acetate, vinyl propionate, vinyl ether, styrene, acrylonitrile, and methacrylonitrile.
Examples of functional group-containing monomers include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meta ) Acrylate, 4-hydroxybutyl (meth) acrylate, N-methylolacrylamide, hydroxyl group-containing monomers such as allyl alcohol, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) ) Tertiary amino group-containing monomers such as acrylate, amide group-containing monomers such as acrylamide and methacrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide N- ethoxymethyl (meth) acrylamide, N-t-butyl acrylamide, N- substituted amide group-containing monomers such as N- octyl acrylamide, an epoxy group-containing monomers such as glycidyl methacrylate.
By using such a material, it is excellent in adhesiveness, cohesiveness, and durability, and arbitrary quality and characteristics according to the application can be obtained by selecting the kind and combination of monomers.
The weight average molecular weight of the pressure-sensitive adhesive component is preferably 300,000 to 3,000,000, more preferably 500,000 to 2,000,000. If the molecular weight of the pressure-sensitive adhesive component is too low, the pressure-sensitive adhesive strength and cohesive strength of the pressure-sensitive adhesive will be poor, and sufficient blister resistance will not be obtained. Workability of sticking deteriorates.

Moreover, it is preferable that the glass transition point (Tg) of an adhesive component is -20 degrees C or less. When the glass transition point exceeds −20 ° C., the pressure-sensitive adhesive becomes hard depending on the use temperature, and the adhesiveness may not be maintained.
As the above-mentioned pressure-sensitive adhesive, either a crosslinked type or a non-crosslinked type can be used. In the case of the crosslinking type, examples include methods using various crosslinking agents such as epoxy compounds, isocyanate compounds, metal chelate compounds, metal alkoxides, metal salts, amine compounds, hydrazine compounds, aldehyde compounds, etc. The functional group is appropriately selected.
The curable component contained in the pressure-sensitive adhesive layers 13, 16, 18, 19, 23, 26, 29 is not particularly limited, but has a thermosetting property such as an epoxy resin, a phenol resin, a melamine resin, or a polyester resin, or described later. The thing which has radiation curability to perform is mentioned, Especially the thing which has radiation curability is preferable. As a result, the curable component can be cured at room temperature or low temperature in a very short time, and the handleability is excellent.
The term “radiation curable” as used herein means, for example, that molecular chain growth or crosslinking reaction is induced by irradiation with ultraviolet rays, laser beams, α rays, β rays, γ rays, X rays, or electron beams, and the curable components are cured. Means nature.
Such a radiation curable component is not particularly limited, but for example, a component having an acrylic monomer or oligomer is preferable. Thereby, an adhesive layer having excellent weather resistance can be formed.
Examples of such radiation curable acrylic monomers and / or oligomers include hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and pentaerythritol tri (meth) acrylate. , Trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, urethane acrylate, epoxy acrylate, polyester acrylate, and the like. These may be used alone or in combination.

Further, the acrylic monomer or oligomer preferably includes a reactive monomer or oligomer having an acryloyl group, and more preferably has two or more acryloyl groups. By including two or more acryloyl groups, the network structure is sufficiently formed, the cohesiveness of the pressure-sensitive adhesive is further improved, and a good pressure-sensitive adhesive layer is obtained.
0.05-50 weight part is preferable with respect to 100 weight part of said adhesive components, and, as for content of curable components, such as the said radiation-curable component, 0.1-20 weight part is more preferable. If the amount of the curable component is too small, the effect of suppressing foaming and swelling due to the generated gas may not be sufficiently obtained due to the cohesive force of the pressure-sensitive adhesive. On the other hand, when there is too much quantity of a sclerosing | hardenable component, the adhesive layers 13, 16, 18, 19, 23, 26, and 29 will become hard too much and there exists a possibility that adhesive force may fall.
When the curable component is blended with the pressure-sensitive adhesive component, those having good compatibility with the pressure-sensitive adhesive component are preferable. In addition, the curable component can be used as a copolymer with the main polymer of the pressure-sensitive adhesive component.
When the radiation curable component is cured by ultraviolet irradiation or the like, the pressure-sensitive adhesive layers 13, 16, 18, 19, 23, 26, and 29 are preferably light-transmitting, for example, substantially transparent or translucent (colorless) Or, it is preferable that the pressure-sensitive adhesive layers 13, 16, 18, 19, 23, 26, and 29 can be easily cured.
When the radiation curable component is cured by ultraviolet irradiation or the like, a polymerization initiator may be added. For example, benzoin, benzoin methyl ether, benzoin ethyl ether, o-benzoylbenzoic acid methyl-p-benzoin ethyl ether, Benzoins such as benzoin isopropyl ether and α-methylbenzoin, dimethylbenzyl ketal, trichloroacetophenone, acetophenones such as 2,2-diethoxyacetophenone and 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, Propiophenones such as 2-hydroxy-4′-isopropyl-2-methylpropiophenone, benzophenone, methylbenzophenone, p-chlorobenzophenone, p-dimethylaminobenzophenone, etc. Benzophenone compounds, 2-black thio xanthone, 2-ethyl thioxanthone, thioxanthone such as 2-isopropylthioxanthone, benzyl, dibenzosuberone, alpha-acyl oxime esters.

The addition amount of such a polymerization initiator is preferably about 0.5 to 30 parts by weight, and more preferably about 1 to 20 parts by weight with respect to 100 parts by weight of the radiation curable component.
On the other hand, when the radiation curable component is cured by electron beam irradiation, the addition of the polymerization initiator is not necessary, but in this case, since the curing reaction is significantly inhibited by the presence of oxygen, nitrogen or the like is not necessary. It is necessary to carry out under an active gas atmosphere. Or it is preferable to carry out in the state which stuck the peeling film which consists of transparent resin.
Moreover, a polymerization accelerator can be used together with the above polymerization initiator. Examples of such a polymerization accelerator include 4,4′-bis (diethylamine) benzophenone, ethyl N-dimethylaminobenzoate, and dimethylethanolamine. , Glycine and the like.
The polymerization initiator and polymerization accelerator as described above can be added in microcapsules in order to improve the stability during storage.
Furthermore, various additives such as a tackifier, a softener (plasticizer), a filler, an anti-aging agent, a silane coupling agent, and the like can be added as other additives as necessary.
Examples of the tackifier include rosin and derivatives thereof, polyterpene, terpene phenol resin, coumarone-indene resin, petroleum resin, styrene resin, and xylene resin.
Examples of the softening agent include liquid polyether, glycol ester, liquid polyterpene, liquid polyacrylate, phthalic acid ester, trimellitic acid ester, and the like.
Examples of the method for forming the pressure-sensitive adhesive layers 13, 16, 18, 19, 23, 26, and 29 mainly composed of the above pressure-sensitive adhesive component and curable component include coating with a die or a comma coater. It is done. Examples of the coating method include a flow coater, a knife coater, a roll coater, and dipping.
The thickness (dry film thickness) of the pressure-sensitive adhesive layers 13, 16, 18, 19, 23, 26, and 29 is not particularly limited, but is preferably about 5 to 100 μm, particularly about 10 to 60 μm.

(NIR reflector dispersed layer in which near infrared reflector is dispersed)
The function of the NIR reflector dispersion layer in which the near-infrared reflector (A) is dispersed is to reduce the near-infrared transmittance in the wavelength region of 850 to 1100 nm to about 50 to 70%, preferably about 30 to 50%. It is desirable that
In the present invention, by providing an NIR reflector dispersion layer, light in the visible light region of an image emitted from the display is relatively well transmitted, and light in the near infrared region is reflected and attenuated.
The near-infrared reflector (A) used in the present invention is a metal oxide fine particle having high light transmittance in the visible light region and low light transmittance in the near-infrared region. One selected from a metal oxide group consisting of natural mica or synthetic mica coated with titanium, iron oxide, titanium oxide and / or iron oxide at a coverage of 10% or more, zinc oxide, zirconium oxide, aluminum oxide That's it.
The near-infrared reflector (A) is composed of ruthenium oxide, titanium oxide, iron oxide, zinc oxide, zirconium oxide, other than natural mica or synthetic mica coated with titanium oxide and / or iron oxide at a coverage of 10% or more. In the case of fine particles of a metal oxide selected from the group consisting of aluminum oxide, the average particle size is preferably 0.01 to 0.5 μm. More preferably, it is 0.02-0.3 micrometer. When the particle diameter is in this range, it is excellent in visible light transmission when a near-infrared reflector dispersion layer is formed, has good near-infrared reflection, and has good dispersibility in the near-infrared reflector (A). It is.
Further, since it has a high light transmittance in the visible light region and a low light transmittance in the near infrared region, it is a natural mica or synthetic mica coated with titanium oxide and / or iron oxide at a coverage of 10% or more ( Hereinafter, it is preferably referred to as coated mica.

This coated mica is obtained by forming a fine particle layer of titanium oxide and / or iron oxide on the surface of scaly natural mica or synthetic mica.
In the NIR reflector dispersion layer in which the coated mica is dispersed, when the scaly particles of each coated mica are captured, a titanium oxide layer having a high refractive index, a natural mica or synthetic mica having a low refractive index, and a near infrared reflector ( A) At the boundary with the surrounding transparent resin layer or pressure-sensitive adhesive layer, light in the visible light region is relatively well transmitted, but light in the near infrared region is reflected, and the amount of near infrared light transmitted through the coated mica is small. Attenuated.
The adjustment of the near-infrared reflecting performance in the NIR reflector-dispersed layer is performed by the addition amount of the near-infrared reflector (A), but the addition amount is not particularly limited and depends on the type of the near-infrared reflector (A). What is necessary is just to select suitably.
The coated mica has a scaly shape and is manufactured with a particle size of about 5 to 60 μm. In order to improve the near-infrared reflection performance, it is necessary to make the reflective surface of the coated mica dispersed inside the NIR reflector dispersion layer as smooth as possible, and it is preferable that the particle diameter of the coated mica is smaller.
The NIR reflector dispersion layer in which the near-infrared reflector (A) is dispersed can be formed by dispersing the near-infrared reflector in a binder or adhesive made of a transparent resin.

Examples of the resin used as the binder include (meth) acrylic resins, (meth) acrylic urethane resins, polyvinyl chloride resins, polyvinylidene chloride resins, melamine resins, urethane resins, styrene resins, Alkyd resins, phenolic resins, epoxy resins, polyester resins, (meth) acrylic silicone resins, alkylpolysiloxane resins, silicone resins, silicone alkyd resins, silicone urethane resins, silicone polyester resins, silicone acrylic resins, etc. Modified silicone resin, polyvinylidene fluoride, fluoroolefin resin such as fluoroolefin vinyl ether polymer, etc., may be thermoplastic resin, thermosetting resin, moisture curable resin, ultraviolet curable resin, electron beam curable resin, etc. Of curable resin Good. Also, organic binder resins such as synthetic rubber such as ethylene-propylene copolymer rubber, polybutadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber or natural rubber; silica sol, alkali silicate, silicon alkoxide and their (hydrolysis) Conventionally known binder resins such as inorganic binders such as condensates and phosphates may be mentioned. These may be used alone or in combination of two or more.
Among these, (meth) acrylic resins, (meth) acrylic urethane resins, (meth) acrylic silicone resins, polyesters can be dried at a relatively low temperature to form a near-infrared absorbing coating film. It is preferably a fluorine-based resin such as a modified resin such as a vinyl resin, a silicone resin, a silicone alkyd resin, a silicone urethane resin, a silicone polyester resin, or a silicone acrylic resin, a polyvinylidene fluoride, or a fluoroolefin vinyl ether polymer. Note that acrylic resins and methacrylic resins are also referred to as acrylic resins.
The glass transition temperature (Tg) is preferably -80 to 160 ° C. As a result, the weather resistance of the binder resin itself is improved, the near infrared shielding performance of the near infrared shielding coating film is maintained, and the weather resistance and physical properties of the near infrared shielding coating itself are further improved. Become. Preferably, it is -50-130 degreeC, More preferably, it is 20-110 degreeC, More preferably, it is 40-100 degreeC.
When dispersed in the pressure-sensitive adhesive, the same pressure-sensitive adhesive as the pressure-sensitive adhesives 13, 16, 18, 19, 23, 26, and 29 is used.

When forming the NIR reflector dispersion layer in which the near-infrared reflector (A) is dispersed, for example, one or more solvents, additives and the like may be included as a composition other than those described above. Such a solvent is not particularly limited, and examples thereof include aromatic solvents such as toluene and xylene; alcohol solvents such as iso-propyl alcohol, n-butyl alcohol, propylene glycol methyl ether, and dipropylene glycol methyl ether; Examples include ester solvents such as butyl acetate, ethyl acetate, and cellosolve acetate; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and one or more organic solvents such as dimethylformamide.
In addition, as the additive, a conventionally known additive generally used in a resin composition for forming a film, a coating film, or the like can be used. For example, a leveling agent; inorganic fine particles such as colloidal silica and alumina sol; Antifoaming agent, anti-sagging agent, silane coupling agent, viscosity modifier, metal deactivator, peroxide decomposer, plasticizer, lubricant, rust preventive agent, organic and inorganic UV absorber, inorganic System heat ray absorbent, organic / inorganic flameproofing agent, antistatic agent and the like.

Examples of the method for applying the NIR reflector dispersed layer in which the near infrared reflector (A) is dispersed include immersion, spraying, brush coating, curtain flow coating, gravure coating, roll coating, spin coating, blade coating, and bar coating. , Reverse coating, die coating, spray coating, electrostatic coating, and the like. In these cases, the organic solvent described above can be appropriately mixed and applied to the resin composition of the NIR reflector dispersion layer.
The thickness of the NIR reflector dispersion layer is not particularly limited as long as it is appropriately set depending on the intended use. For example, the thickness upon drying may be 1 to 50 μm, preferably 2 to 30 μm.

(NIR absorbing dye dispersed layer in which near infrared absorbing dye is dispersed)
As a function of the NIR absorbing dye dispersion layer in which the near infrared absorbing dye (B) is dispersed, the near infrared transmittance in the wavelength region of 850 to 1100 nm is 70% or less in advance in the NIR reflector dispersion layer, preferably 50% or less. It is desirable to further reduce the content of the material to 15% or less, preferably 10% or less.
Specific examples of the near-infrared absorbing dye (B) include an immonium salt compound, a diimmonium salt compound, an aminium salt compound, a nitroso compound and a metal complex thereof, a cyanine compound, a squarylium compound, a thiol nickel complex compound, Aminothiol nickel complex compound, phthalocyanine compound, naphthalocyanine compound, triarylmethane compound, naphthoquinone compound, anthraquinone compound, amino compound, carbon black, antimony oxide, tin oxide doped with indium oxide, periodic table Examples thereof include oxides, carbides or borides of metals belonging to Group 4, Group 5 or Group 6.
These near-infrared absorbing dyes (B) can be used alone or in combination of two or more. By providing the NIR absorbing dye dispersion layer, near infrared rays emitted from the display can be absorbed and shielded.

The near-infrared absorbing dye (B) of the present invention has a long-wavelength near-infrared absorbing dye and a short-wavelength near-infrared absorbing dye each having a maximum absorption capacity in different wavelength bands in the absorption wavelength band of 850 to 1100 nm. It is preferable that it consists of 2 or more types of pigment | dye.
The near-infrared absorbing dye for long wavelengths is one selected from diimmonium salt compounds, and the near-infrared absorbing dye for short wavelengths is phthalocyanine compounds, cyanine compounds, thiol nickel complex compounds It is preferable that it is 1 type, or 2 or more types of pigment | dyes selected from these.
The NIR absorbing dye dispersion layer in which the near infrared absorbing dye (B) is dispersed can be formed by dispersing the near infrared absorbing dye in a binder or pressure-sensitive adhesive made of a transparent resin.

Examples of the resin used as the binder include (meth) acrylic resins, (meth) acrylic urethane resins, polyvinyl chloride resins, polyvinylidene chloride resins, melamine resins, urethane resins, styrene resins, Alkyd resins, phenolic resins, epoxy resins, polyester resins, (meth) acrylic silicone resins, alkylpolysiloxane resins, silicone resins, silicone alkyd resins, silicone urethane resins, silicone polyester resins, silicone acrylic resins, etc. Modified silicone resin, polyvinylidene fluoride, fluoroolefin resin such as fluoroolefin vinyl ether polymer, etc., may be thermoplastic resin, thermosetting resin, moisture curable resin, ultraviolet curable resin, electron beam curable resin, etc. Of curable resin Good. Also, organic binder resins such as synthetic rubber such as ethylene-propylene copolymer rubber, polybutadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber or natural rubber; silica sol, alkali silicate, silicon alkoxide and their (hydrolysis) Conventionally known binder resins such as inorganic binders such as condensates and phosphates may be mentioned. These may be used alone or in combination of two or more.
Among these, (meth) acrylic resins, (meth) acrylic urethane resins, (meth) acrylic silicone resins, polyesters can be dried at a relatively low temperature to form a near-infrared absorbing coating film. It is preferably a fluorine-based resin such as a modified resin such as a vinyl resin, a silicone resin, a silicone alkyd resin, a silicone urethane resin, a silicone polyester resin, or a silicone acrylic resin, a polyvinylidene fluoride, or a fluoroolefin vinyl ether polymer. Note that acrylic resins and methacrylic resins are also referred to as acrylic resins.
When dispersed in the pressure-sensitive adhesive, the same pressure-sensitive adhesive as the pressure-sensitive adhesives 13, 16, 18, 19, 23, 26, and 29 is used.

When forming the NIR absorbing dye-dispersed layer in which the near infrared absorbing dye (B) is dispersed, for example, one or more of solvents, additives and the like may be included as a composition other than those described above. Such a solvent is not particularly limited, and examples thereof include aromatic solvents such as toluene and xylene; alcohol solvents such as iso-propyl alcohol, n-butyl alcohol, propylene glycol methyl ether, and dipropylene glycol methyl ether; Examples include ester solvents such as butyl acetate, ethyl acetate, and cellosolve acetate; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and one or more organic solvents such as dimethylformamide.
In addition, as the additive, a conventionally known additive generally used in a resin composition for forming a film, a coating film, or the like can be used. For example, a leveling agent; inorganic fine particles such as colloidal silica and alumina sol; Antifoaming agent, anti-sagging agent, silane coupling agent, viscosity modifier, metal deactivator, peroxide decomposer, plasticizer, lubricant, rust preventive agent, organic and inorganic UV absorber, inorganic System heat ray absorbent, organic / inorganic flameproofing agent, antistatic agent and the like.
In order to improve the durability of the dye, a quencher or an antioxidant can be added.
Examples of such quenchers include metal complex materials, such as “MIR101” manufactured by Midori Chemical Co., “EST5” manufactured by Sumitomo Seika Co., Ltd., and the like.
Representative antioxidants include hindered amine compounds, hindered phenol compounds, phosphite compounds, and the like, and these can be used alone or in combination of two or more.

Examples of the method for applying the NIR absorbing dye dispersed layer in which the near infrared absorbing dye (B) is dispersed include dipping, spraying, brush coating, curtain flow coating, gravure coating, roll coating, spin coating, blade coating, and bar coating. , Reverse coating, die coating, spray coating, electrostatic coating, and the like. In these cases, the organic solvent described above can be appropriately mixed and applied to the resin composition of the NIR absorbing dye dispersion layer.
The thickness of the NIR absorbing dye dispersion layer is not particularly limited as long as it is appropriately set depending on the intended use. For example, the thickness during drying may be 1 to 50 μm, preferably 1 to 20 μm.

(UV absorbing layer)
If necessary, one or more ultraviolet absorbing layers can be provided at an appropriate position of the optical filter. As a method for forming the ultraviolet absorbing layer, a method of mixing an ultraviolet absorber in a transparent substrate, a transparent resin layer, or an adhesive layer, a coating solution containing the ultraviolet absorber is directly or otherwise applied to the transparent substrate. The method of apply | coating through the layer of this is mentioned. The ultraviolet absorbing layer is provided closer to the visual side than the near infrared absorbing layer in order to prevent the near infrared absorbing layer from being deteriorated by external light. As the ultraviolet absorber, either an organic ultraviolet absorber or an inorganic ultraviolet absorber can be used, but the wavelength at 50% transmittance is preferably 350 to 420 nm, more preferably 360 to 400 nm, and 350 nm. At a lower wavelength, the ultraviolet blocking ability is weak, and at a wavelength higher than 420 nm, the coloring becomes strong, which is not preferable.

  Examples of organic ultraviolet absorbers include 2- (2′-hydroxy-5′-t-butylphenyl) benzotriazole, 2- (2-hydroxy-3 ′, 5′-di-t-butylphenyl) benzotriazole, and the like. Benzotriazole compounds, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone and other benzophenone compounds, phenyl salicylate, 4-t-butylphenyl salicylate, 2,5 Hydroxybenzoate compounds such as -t-butyl-4-hydroxybenzoic acid n-hexadecyl ester and 2,4-di-t-butylphenyl-3 ', 5'-di-t-butyl-4'-hydroxybenzoate Etc. Examples of inorganic ultraviolet absorbers include titanium oxide, zinc oxide, cerium oxide, iron oxide, and barium sulfate. These ultraviolet absorbers can be used alone or in combination of two or more.

(Neon light absorption layer)
One or more neon light absorbing layers can be provided at an appropriate position of the optical filter as necessary. The neon light absorption layer is for making the red color of an image clearer by removing neon light (absorption wavelength: 580 to 620 nm) emitted from the PDP using a neon light absorber. As a method for forming a neon light absorbing layer, a neon light absorbing agent is mixed in a transparent base material, a transparent resin layer, or an adhesive layer, and a coating liquid containing a neon light absorbing agent is applied on the transparent base material. The method of apply | coating directly or through another layer is mentioned. Examples of the neon light absorber include suitable dyes having a maximum absorption wavelength in a wavelength range of 580 to 620 nm among dyes such as cyanine, squarylium, azomethine, xanthene, oxonol, and azo. It is done. These neon light absorbers can be used alone or in combination of two or more.

(Electromagnetic wave shielding layer)
Conventionally, various transparent conductive films and electromagnetic wave shielding films have been developed in response to the requirement that electromagnetic waves generated from a display leak outside and prevent adverse effects on the human body. The known electromagnetic shielding layer is roughly classified into an electromagnetic shielding layer made of a transparent conductive film and an electromagnetic shielding layer made of a conductive metal mesh. An electromagnetic wave shielding layer made of a transparent conductive film is superior in transparency to an electromagnetic wave shielding layer made of a metal mesh, but has a large surface resistivity and inferior electromagnetic wave shielding performance. Since a plasma display generates a strong electromagnetic wave, an electromagnetic wave shielding layer made of a metal mesh is preferable.
Furthermore, as a method for producing a conductive metal mesh, the following methods (1) to (3) may be mentioned.
(1) An etching method in which a metal foil is bonded to a transparent substrate, or a metal thin film is deposited on the transparent substrate, and then a conductive metal pattern is formed by a photolithographic method.
(2) A printing-plating method in which a conductive metal pattern is printed on a transparent substrate and then plated to form a conductive metal pattern.
(3) An exposure development method of forming a conductive metal pattern by forming a fine line pattern with exposed and developed metallic silver and then physically developing and / or plating the metallic silver.
The exposure development method is a method described in Japanese Patent Application Laid-Open No. 2004-221564, that is, a silver salt-containing layer containing a silver salt provided on a support is exposed and developed to form metallic silver. Forming a conductive metal part having conductive metal particles supported on the metal silver part by forming a part and a light transmissive part, and further subjecting the metal silver part to physical development and / or plating treatment; There is a method (herein referred to as DTR-plating method) described in WO2004 / 007810.

  The configuration and manufacturing method of the electromagnetic wave shielding layer applicable to the present invention are not particularly limited, but a method of manufacturing with a conductive metal mesh is preferable. In particular, (3) the exposure development method, in particular, the DTR-plating method is excellent in that both a high electromagnetic shielding effect and high transparency (high total light transmittance) can be achieved, and an electromagnetic shielding layer by other methods. Compared with the above, since higher transparency (high total light transmittance) can be obtained, it is possible to make the additive concentration of the black pigment (light absorbing material) higher and to further increase the black and white contrast.

(DTR-plating method)
Hereinafter, a method for producing an electromagnetic wave shielding layer by the above-described DTR-plating method will be described.
It is preferable that a physical development nucleus layer is provided in advance on the transparent base material (the transparent base materials 14 and 24 in FIGS. 1 and 2) on which the electromagnetic wave shielding layers 15 and 25 are formed. As the physical development nuclei, fine particles (having a particle size of about 1 to several tens of nm) made of heavy metals or sulfides thereof are used. Examples thereof include colloids such as gold and silver, metal sulfides obtained by mixing water-soluble salts such as palladium and zinc and sulfides, and the like. The fine particle layer of these physical development nuclei can be provided on the transparent substrate by a vacuum deposition method, a cathode sputtering method, a coating method or the like. From the viewpoint of production efficiency, a coating method is preferably used. The content of physical development nuclei in the physical development nuclei layer is suitably about 0.1 to 10 mg per square meter in solid content.

  The transparent substrate can be provided with an adhesive layer of a polymer latex layer such as vinylidene chloride or polyurethane, and an intermediate layer made of a hydrophilic binder such as gelatin can be provided between the adhesive layer and the physical development nucleus layer. it can.

  The physical development nucleus layer preferably contains a hydrophilic binder. The amount of the hydrophilic binder is preferably about 10 to 300% by mass with respect to the physical development nucleus. As the hydrophilic binder, gelatin, gum arabic, cellulose, albumin, casein, sodium alginate, various starches, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, a copolymer of acrylamide and vinyl imidazole, and the like can be used. The physical development nucleus layer may also contain a hydrophilic binder crosslinking agent.

  The physical development nucleus layer and the intermediate layer can be applied by an application method such as dip coating, slide coating, curtain coating, bar coating, air knife coating, roll coating, gravure coating, spray coating, and the like. In the present invention, the physical development nucleus layer is preferably provided as a continuous and uniform layer by the above-described coating method.

  The supply of silver halide for depositing metallic silver on the physical development nucleus layer is performed by a method in which the physical development nucleus layer and the silver halide emulsion layer are integrally formed in this order on a transparent substrate, or another paper or plastic resin. There is a method of supplying a soluble silver complex salt from a silver halide emulsion layer provided on a substrate such as a film. From the viewpoint of cost and production efficiency, it is preferable to provide the former physical development nucleus layer and silver halide emulsion layer integrally.

The silver halide emulsion can be produced according to a general method for producing a silver halide emulsion of a silver halide photographic light-sensitive material. The silver halide emulsion is usually prepared by mixing and ripening an aqueous silver nitrate solution, an aqueous halogen solution of sodium chloride or sodium bromide in the presence of gelatin.
The silver halide composition of the silver halide emulsion layer preferably contains 80 mol% or more of silver chloride, and more preferably 90 mol% or more is silver chloride. The conductivity of the physically developed silver formed by increasing the silver chloride content is improved.

  The silver halide emulsion layer is sensitive to various light sources. As one method for producing an electromagnetic wave shielding material, for example, formation of physically developed silver having a fine line pattern such as a mesh shape can be mentioned. In this case, the silver halide emulsion layer is exposed in the form of a fine line pattern. As an exposure method, a method in which a transparent original having a fine line pattern and the silver halide emulsion layer are in close contact with each other and exposed with ultraviolet light, or various laser beams are used. Scanning exposure method. The former contact exposure using ultraviolet light is possible even if the silver halide has relatively low photosensitivity, but in the case of scanning exposure using laser light, relatively high photosensitivity is required. Therefore, when the latter exposure method is used, the silver halide may be subjected to chemical sensitization or spectral sensitization with a sensitizing dye in order to increase the sensitivity of the silver halide. Chemical sensitization includes metal sensitization using a gold compound or silver compound, sulfur sensitization using a sulfur compound, or a combination thereof. Gold-sulfur sensitization using a gold compound and a sulfur compound in combination is preferable. In the exposure method using the laser beam described above, a laser beam having an oscillation wavelength of 450 nm or less, for example, a blue semiconductor laser (also referred to as a violet laser diode) having an oscillation wavelength of 400 to 430 nm is used. It can be handled even under a yellow fluorescent lamp.

  Halation or irradiation on an arbitrary position on the transparent substrate on which the physical development nucleus layer is provided, for example, an adhesive layer, an intermediate layer, a physical development nucleus layer or a silver halide emulsion layer, or a backing layer provided with a support interposed therebetween You may contain the dye or pigment for prevention.

  When producing an electromagnetic shielding material using a photosensitive material in which a silver halide emulsion layer is coated directly on the physical development nucleus layer or via an intermediate layer, an arbitrary fine line pattern such as a mesh pattern is used. After exposing a transparent original and the photosensitive material in close contact, or by scanning and exposing a digital image of an arbitrary fine line pattern onto the photosensitive material with various laser light output machines, in the presence of a soluble silver complex salt forming agent and a reducing agent. Silver complex diffusion transfer development (DTR development) occurs by processing in an alkaline solution, the silver halide in the unexposed area is dissolved to form a silver complex salt, which is reduced on the physical development nuclei, and metallic silver is precipitated to form a fine line. A physically developed silver thin film with a pattern can be obtained. The exposed portion is chemically developed in the silver halide emulsion layer to become blackened silver. After development, the silver halide emulsion layer and the intermediate layer, or the protective layer provided as necessary, are washed away with water, and a physically developed silver thin film having a fine line pattern is exposed on the surface.

  After DTR development, the silver halide emulsion layer or the like provided on the physical development nucleus layer may be removed by washing with water or transferring and peeling to a release paper or the like. There are two methods for removing the water washing: a method of removing hot water using a scrubbing roller or the like while jetting it with a nozzle or the like, and a method of removing hot water by jetting with a nozzle or the like.

  On the other hand, when the soluble silver complex salt is supplied from a silver halide emulsion layer provided on a substrate different from the transparent substrate on which the physical development nucleus layer is coated, the silver halide emulsion layer is exposed as described above. After that, a transparent substrate coated with a physical development nucleus layer and another photosensitive material coated with a silver halide emulsion layer are superposed in an alkaline solution in the presence of a soluble silver complexing agent and a reducing agent. After several tens of seconds to several minutes after taking out from the alkaline solution, the both are removed to obtain a physically developed silver thin film having a fine line pattern deposited on the physical development nuclei.

  Next, a soluble silver complex salt forming agent, a reducing agent, and an alkali solution necessary for silver complex diffusion transfer development will be described. The soluble silver complex salt forming agent is a compound that dissolves silver halide to form a soluble silver complex salt, and the reducing agent is a compound that reduces this soluble silver complex salt to precipitate metallic silver on physical development nuclei. These actions are performed in an alkaline solution.

  Examples of the soluble silver complex forming agent used in the present invention include sodium thiosulfate, thiosulfate such as ammonium thiosulfate, thiocyanate such as sodium thiocyanate and ammonium thiocyanate, alkanolamine, sodium sulfite, and potassium bisulfite. Sulfites such as T. H. Examples include the compounds described in 474-475 (1977) of James The Theory of the Photographic Process 4th edition.

  As the reducing agent, a developing agent known in the field of photographic development can be used. For example, polyhydroxybenzenes such as hydroquinone, catechol, pyrogallol, methylhydroquinone, chlorohydroquinone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-3-pyrazolidone, 1-phenyl-4-methyl- Examples include 3-pyrazolidones such as 4-hydroxymethyl-3-pyrazolidone, paramethylaminophenol, paraaminophenol, parahydroxyphenylglycine, paraphenylenediamine, and the like.

  The above-mentioned soluble silver complex salt forming agent and reducing agent may be applied to the transparent substrate together with the physical development nucleus layer, added to the silver halide emulsion layer, or contained in the alkaline solution. It may be allowed to be contained, and may be further contained in a plurality of positions, but is preferably contained at least in the alkaline liquid.

  The content of the soluble silver complex salt forming agent in the alkaline solution is suitably used in the range of 0.1 to 5 mol per liter of the developer, and the reducing agent is 0.05 to 1 per liter of the developer. It is suitable to use in the molar range.

  The pH of the alkaline solution is preferably 10 or more, and more preferably in the range of 11-14. Application of the alkaline solution for silver complex diffusion transfer development may be an immersion method or a coating method. The immersion method is, for example, transporting while immersing a transparent substrate provided with a physical development nucleus layer and a silver halide emulsion layer in an alkaline solution stored in a large amount in a tank. For example, about 40 to 120 ml of an alkali solution per square meter is coated on the silver halide emulsion layer.

As described above, there are fine line patterns in which, for example, fine lines having a line width of about 10 to 100 μm are provided in a grid pattern in the vertical and horizontal directions. If the narrow line width is reduced and the interval between the gratings is increased, the translucency increases. However, the conductivity decreases, and conversely, if the fine line width is increased to reduce the lattice spacing, the translucency is decreased and the conductivity is increased. The physically developed silver having an arbitrary fine line pattern formed on the transparent substrate according to the present invention simultaneously satisfies the light transmittance of 50% or more of the total light transmittance and the conductivity of 10 ohm / □ or less of the surface resistivity. It is difficult. Specifically, this physically developed silver has a surface resistivity of 50 ohms / square or less, preferably 20 ohms / square or less, but has a fine line width of 50 μm or less, for example, a pattern with a fine line width of 20 μm. When the light transmittance is 50% or more, the surface resistivity becomes several hundred ohms / square to 1000 ohms / square or more. However, since this physical development silver itself has a conductive silver image with a solid silver image formed, the fine line pattern is reduced to 0 by applying plating (plating) with a metal such as copper or nickel, particularly electrolytic plating. When the thickness is 5 to 15 μm and the line width is 10 to 50 μm, the surface resistivity is 10 ohms / square or less even for a translucent thin line pattern having a total light transmittance of 50% or more, preferably 60% or more. Preferably, the conductivity of 7 ohm / square or less can be maintained.
In order to improve the total light transmittance of the metal mesh, it is necessary to sufficiently increase the area of the light transmission portion between the fine lines with respect to the area of the region where the fine lines are provided. For this reason, it is preferable that the space | interval of a thin wire | line is 100-900 micrometers, More preferably, it is 150-700 micrometers.

  The thickness of the metal-plated fine line pattern can be arbitrarily changed according to desired characteristics, but is in the range of 0.5 to 15 μm, preferably 2 to 12 μm. Moreover, the electromagnetic shielding material produced by the above-mentioned method can obtain a shielding effect of 30 dB or more over a wide frequency band such as 30 MHz to 1,000 MHz.

  The thin line pattern of physically developed silver can be plated by either electroless plating, electrolytic plating, or a combination of the two. However, when preparing an electromagnetic shielding layer on a transparent substrate, From the viewpoint that at least a series of treatments of fine line pattern exposure, development treatment and plating treatment can be applied to a roll-like long web provided with a physical development nucleus layer and a silver halide emulsion layer, electrolytic plating or A method combining electroless plating is preferred.

  In the present invention, the metal plating method can be performed by a known method. For example, the electrolytic plating method is a conventionally known method such as copper, nickel, silver, gold, solder, or a multilayer or composite system of copper / nickel. For these, reference can be made to documents such as “Surface Treatment Technology Overview; Technical Data Center, Inc., December 21, 1987, first edition, pages 281 to 422”.

It is preferable to use copper and / or nickel for reasons such as easy plating, excellent electrical conductivity, plating on a thick film, and low cost. As an example of electrolytic plating, the transparent base material on which the above-described physically developed silver is formed is immersed in a bath mainly composed of copper sulfate, sulfuric acid and the like, and a current density of 1 to 20 amperes / percent at 10 to 40 ° C. Plating can be performed by energizing at dm ² .

  The electromagnetic wave shielding layer obtained by the above method has a total light transmittance of 50% or more and a surface resistivity of 10 ohm / □ or less when the fine line pattern has a thickness of 0.5 to 15 μm and a line width of 10 to 50 μm. It has excellent light transmission performance and conductive performance, and can exhibit a shielding effect of 30 dB or more over a wide frequency band such as 30 MHz to 1,000 MHz.

  In the case of the above-described DTR-plating method, physical development nuclei remain on the entire surface of the transparent substrate. Thereby, although there is a theory that the DTR-plating method is insufficient in terms of transparency and conductivity, there are few physical development nuclei remaining after development, and the influence on the transparency of the electromagnetic wave shielding layer is very small. Since it is possible to physically develop metallic silver having high conductivity with respect to the catalyst core more efficiently than that, it is possible to carry out good electroless plating and / or electrolytic plating on the metallic silver. Transparency and conductivity can be obtained.

(Optical filter manufacturing method)
Although the manufacturing method of the optical filters 10 and 20 shown in FIG.1 and FIG.2 is not specifically limited, For example, the method shown below can be used. In addition, in order to protect an adhesive layer during a manufacturing process or after a process, you may laminate | stack release paper arbitrarily.

(1) In the case of the optical filter 10 shown in FIG.
The first laminated body A is produced by providing the antireflection layer 11 on one side of the first transparent substrate 12.
In the second laminate (electromagnetic wave shielding film) B, an electromagnetic wave shielding layer 15 is formed on one surface of the second transparent base material 14 by a DTR-plating method or the like, and the near-infrared absorbing dye is further formed on the electromagnetic wave shielding layer 15. By forming the pressure-sensitive adhesive layer 16 to which (B) is added and forming the pressure-sensitive adhesive layer 13 in which the black pigment is dispersed on the surface of the second transparent substrate 14 opposite to the electromagnetic wave shielding layer 15. Make it.
The third laminate C is prepared by adding a near-infrared reflective agent (A) to the third transparent substrate 17.
The first laminated body A, the second laminated body B, and the third laminated body C are arranged in an arbitrary order (or simultaneously).
The optical filter 10 is obtained by laminating through the pressure-sensitive adhesive layers 13 and 16. That is, the laminates A, B, and C are laminated in this order via the adhesive layers 13 and 16.

(2) In the case of the optical filter 20 shown in FIG.
The first laminate A is produced by providing the antireflection layer 21 on one side of the first transparent base material 22.
In the second laminate (electromagnetic wave shielding film) B, an electromagnetic wave shielding layer 25 is formed on one surface of the second transparent base material 24 by a DTR-plating method or the like, and an ultraviolet absorber is added on the electromagnetic wave shielding layer 25. The pressure-sensitive adhesive layer 26 is formed, and the pressure-sensitive adhesive layer 23 in which the black pigment is dispersed is formed on the surface of the second transparent base 24 opposite to the electromagnetic wave shielding layer 25.
The third laminate C is obtained by adhering a transparent resin layer prepared by adding a near-infrared reflector (A) and a near-infrared absorbing dye (B) to the third transparent substrates 27 and 28, respectively. It is produced by laminating via the agent 29.
The first laminated body A, the second laminated body B, and the third laminated body C are laminated in any order (or simultaneously) via the pressure-sensitive adhesive layers 23 and 26 to obtain the optical filter 20. That is, the laminates A, B, and C are laminated in this order via the adhesive layers 23 and 26.

  The optical filters 10 and 20 of the present embodiment can be used by sticking to the front panel P of the display or the like with the adhesive layers 18 and 19 provided on the innermost side.

  According to the optical filter for display of this embodiment, the electromagnetic wave shielding layer, the NIR reflector dispersed layer in which the near infrared reflector (A) is dispersed in the transparent resin layer and / or the adhesive layer, and the near infrared absorption By providing the NIR absorbing dye dispersed layer in which the dye (B) is dispersed in the transparent resin layer and / or the pressure-sensitive adhesive layer, the function of shielding near infrared rays is exhibited together with the electromagnetic shielding properties. When near-infrared rays from the display are incident on the optical filter, the near-infrared rays are reflected by the NIR reflector dispersion layer and the amount of near-infrared rays is reduced. Next, attenuated near infrared rays are absorbed by the NIR absorbing dye dispersion layer, so that the amount of the near infrared absorbing dye (B) used can be reduced, and the excellent electromagnetic shielding effect and near infrared shielding effect are maintained. However, it can be manufactured at low cost.

  The present invention can be used for optical filters used in various displays such as CRT and PDP (plasma display).

It is typical sectional drawing which shows an example of the layer structure of the optical filter of this invention. It is typical sectional drawing which shows the other example of the layer structure of the optical filter of this invention.

Explanation of symbols

P ... front panel of display, 10, 20 ... optical filter for display, 11, 21 ... antireflection layer, 15, 25 ... electromagnetic wave shielding layer, 16 ... adhesive layer in which near infrared absorbing dye is dispersed (NIR absorbing dye dispersion) Layers), 17, 27 ... transparent resin layer (NIR reflector dispersion layer) in which a near infrared reflecting agent is dispersed, 28 ... transparent resin layer (NIR absorbing dye dispersion layer) in which a near infrared absorbing pigment is dispersed

Claims (8)

  In the optical filter for display provided on the front surface of the display, an electromagnetic wave shielding layer and a near-infrared reflective agent (A) made of metal oxide fine particles are transparent resin layer and / or adhesive layer in the constituent layers of the optical filter. A NIR reflector dispersion layer dispersed therein, and a NIR absorption dye dispersion layer in which the near-infrared absorbing dye (B) is dispersed in the transparent resin layer and / or the pressure-sensitive adhesive layer. Optical filter for display.   Natural mica or synthetic mica coated with the near-infrared reflector (A) at a coverage of 10% or more with ruthenium oxide, titanium oxide, iron oxide, titanium oxide and / or iron oxide, zinc oxide, zirconium oxide, oxidation 3. The optical filter for display according to claim 1, wherein the optical filter is one or more selected from the group of metal oxides made of aluminum.   The near-infrared absorbing dye (B) is composed of two types of absorbing dye for long wavelength and absorbing dye for short wavelength each having a maximum absorption capacity in different wavelength bands in the absorption wavelength band of 850 nm to 1100 nm. The near-infrared absorbing dye for long wavelengths is one selected from diimmonium salt compounds, and the near-infrared absorbing dye for short wavelengths is a phthalocyanine compound, cyanine compound, thiol nickel complex salt The optical filter for display according to any one of claims 1 to 2, wherein the optical filter for display is one or more dyes selected from compounds.   The display according to any one of claims 1 to 3, wherein a transmittance for near infrared rays having a wavelength of 800 nm to 1100 nm by both of the NIR reflector dispersion layer and the NIR absorbing dye dispersion layer is 20% or less. Optical filter.   The optical filter for display according to any one of claims 1 to 4, wherein the electromagnetic wave shielding layer is made of a conductive metal mesh.   The electromagnetic wave shielding layer is a conductive metal mesh in which a fine line pattern is formed by electroless plating and / or electrolytic plating of a metal using a physically developed metallic silver as a catalyst core. 5. The optical filter for display according to any one of 5 above.   The display optical according to claim 1, wherein the optical filter has one or more layers among an ultraviolet absorption layer, a neon light absorption layer, an antireflection layer, and an antiglare layer. filter.   The optical filter for display according to any one of claims 1 to 7, wherein the display is a plasma display.

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