JP2008102340A - Visible light absorbing filter, optical filter for flat panel display and plasma display panel using them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visible light absorbing filter having visible light absorption power in near 590 mm and high transparency in a visible range except near 590 mm, high durability, small environmental effect and manufactured with high productivity and low cost and to provide an optical filter and a plasma display having the filter. <P>SOLUTION: The visible light absorbing filter has a polymer layer obtained from a dye having the maximum absorption in 570-610 nm and an aqueous dispersion of a polymer on a support and the polymer layer is cross-linked by a cross-linking agent and has the minimum transmittance in 570-610 nm. The optical filter having the filter and the plasma display panel using them are provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a composition and filter having a maximum absorption at 570 to 610 nm, which is installed on the front surface of a plasma display and selectively absorbs unnecessary light emission from the plasma display panel.
The present invention also relates to a filter that absorbs visible light and near-infrared light, which is installed in front of a plasma display panel (PDP).

  The plasma display panel (PDP) displays an image by applying a high voltage to a gas such as xenon and emitting plasma, but when the excited gas molecules such as xenon and neon become more stable, 570 ~ Visible light having a peak at 610 nm and near infrared rays are emitted. This visible light is unnecessary light emission at a shorter wavelength than the red light emission required for the PDP, and there is a problem that if this light is not cut, red will be expressed in an orangeish color. On the other hand, near-infrared rays from the PDP cause a harmful effect such as a malfunction of the remote control device, and thus it is necessary to take a shielding measure such as absorbing and removing it. Actually, a filter having a maximum absorption at 570 to 610 nm and a near-infrared absorbing film are mounted on the front of a television using PDP, that is, a so-called plasma television.

Conventionally, several pigments and dyes having a maximum absorption at 570 to 610 nm are known, and a visible light absorption filter using them is known.
Examples thereof include organic dyes as exemplified in Patent Document 1, which are used for optical filters for PDP and the like. For PDP use, this organic dye is dissolved or dispersed together with an organic solvent and a binder resin, and applied to the film to form a film having a filter function having a maximum absorption at 570 to 610 nm. Further, an organic dye is applied to a film together with an adhesive and an organic solvent, and the dye is contained in the adhesive layer.
However, since this use mode uses an organic solvent, it has a drawback of having a great influence on the environment. In addition, the manufacturing equipment needs to be explosion-proof equipment, which requires a large capital investment.
As a method with little or no such problem, there is a method using a water-soluble dye as exemplified in Patent Document 2. It has been proposed that this dye is dissolved in water together with a water-soluble binder, specifically gelatin, and applied to a film to form a film having a filter function having a maximum absorption at 570 to 610 nm and used for PDP. .

JP 2002-251144 A JP 2003-29022 A

The patent documents described above in the background art section are disclosures of techniques that have been improved for each purpose, but the following problems remain.
For water-soluble dyes that can be applied to films without using a large amount of organic solvent, there is a problem that durability, especially light resistance and absorption ability at 570 to 610 nm under high temperature and high humidity are reduced, and improvement is required. It was.
When we examined these water-soluble dyes, it was found that the water-soluble dye was decomposed in the gelatin binder and the absorption ability at 570 to 610 nm was lowered.

The present invention has been made in view of such circumstances, and the object of the present invention is to have a high durability while having an absorption ability of 570 to 610 nm, and has a low adverse effect on the environment, and a high productivity. An object of the present invention is to provide a film having an absorption ability of 570 to 610 nm and having low cost.
Another object of the present invention is to provide an optical filter having the film and a flat panel display panel such as a plasma display panel equipped with the optical filter.

The above problems have been solved by the following invention.
As a result of repeated studies, the present inventor has made it possible to suppress the degradation of the dye by allowing the water-soluble dye to be present in the polymer layer obtained from the polymer aqueous dispersion. Based on this discovery, the present invention has been made. Moreover, the coating of the composition in which the aqueous dispersion of the polymer and the water-soluble dye are dispersed using an aqueous solvent does not require expensive capital investment, unlike the organic solvent coating equipment. The benefits are also great. Furthermore, the use of the organic solvent can be remarkably reduced or it can be produced without using it at all, and the environmental influence due to the release of the organic solvent to the environment can be avoided.
(1)
On a support, it has a polymer layer obtained from a dye having an absorption maximum at 570 to 610 nm and an aqueous dispersion of the polymer, and the polymer layer is crosslinked with a crosslinking agent. A visible light absorbing filter having a minimum value of transmittance.
(2)
The visible light absorptive filter having a minimum transmittance of 570 to 610 nm according to (1), wherein the water-soluble polymer mass ratio in the polymer layer is 0 to 50%.
(3)
The visible light absorptive filter having a minimum value of transmittance at 570 to 610 nm according to (1) or (2), wherein a water-soluble polymer mass ratio in the polymer layer is 10% or less.
(4)
The crosslinking agent contains at least a carbodiimide compound, an epoxy compound, an active vinyl compound, an active halogen compound, or a haloamidinium salt, wherein the transmittance is minimal at 570 to 610 nm according to any one of (1) to (3) A visible light absorbing filter having a value.
(5)
The visible light-absorbing filter having a minimum value of transmittance at 570 to 610 nm according to any one of (1) to (4), wherein the dye having an absorption maximum at 570 to 610 nm has a water-soluble group.
(6)
The visible light-absorbing filter having a minimum transmittance at 570 to 610 nm according to any one of (1) to (5), wherein the aqueous polymer dispersion contains an acrylic resin.
(7)
The visible light absorptive filter having a minimum value of transmittance at 570 to 610 nm according to any one of (1) to (6), wherein the support is a transparent plastic film.
(8)
The visible light absorptive filter having a minimum value of transmittance at 570 to 610 nm according to any one of (1) to (7), wherein the transmittance of light at 590 nm is 60% or less.
(9)
The visible light absorbing filter having a minimum value of transmittance at 570 to 610 nm according to any one of (1) to (8), comprising a near infrared absorbing dye.
(10)
The visible light absorption filter having a minimum value of transmittance at 570 to 610 nm according to any one of (1) to (9), wherein the visible light absorption filter has a conductive pattern made of metal.
(11)
The visible light absorption filter having a minimum value of transmittance at 570 to 610 nm according to (10), which has a conductive pattern containing metallic silver.
(12)
The visible light absorption filter having a minimum value of transmittance at 570 to 610 nm according to (10) or (11), wherein the conductive pattern contains developed silver.
(13)
An optical filter for a flat panel display using the visible light absorption filter having a minimum transmittance of 570 to 610 nm according to any one of (1) to (12).
(14)
The optical filter for a flat panel display according to (13), which is used for a plasma display.
(15)
The visible light absorption filter having a minimum value of transmittance at 570 to 610 nm according to any one of (1) to (12) or the optical filter for a flat panel display panel according to any one of (13) to (14) A plasma display panel comprising:

According to the present invention, it has high durability (heat resistance, moist heat resistance, light resistance) while having an absorption ability of 570 to 610 nm, and has high productivity and low cost with little adverse effect on the environment. It is possible to provide a filter having an absorption ability of 570 to 610 nm. In addition, the image quality can be improved without significantly deteriorating the brightness of the plasma display, and an optical filter having excellent optical characteristics can be provided. Furthermore, it excels in electromagnetic wave shielding ability to block electromagnetic waves that have been pointed out to be harmful to health generated from plasma displays. Furthermore, near-infrared rays in the vicinity of 800 to 1000 nm emitted from plasma displays are efficiently produced. Therefore, it is possible to provide an optical filter that does not adversely affect the wavelengths used by the remote control of peripheral electronic devices, transmission optical communication, and the like, and can prevent malfunctions thereof.
Furthermore, an optical filter having excellent weather resistance can be provided at a low cost.
Moreover, the plasma display equipped with the optical filter which has the said film which has 570-610 nm absorption ability can be provided.

The present invention is described in further detail below. In the present specification, “to” is used as a meaning including numerical values described before and after the lower limit value and the upper limit value.
The filter of the present invention absorbs visible light of 570 to 610 nm and has a minimum value of transmittance at 570 to 610 nm. As described above, since PDP emits unnecessary visible light in this wavelength region, it is necessary to cut the light in this region to a level where there is no practical problem using an optical filter. %, Preferably 60% or less and 2% or more, and the transmittance at 625 nm and 450 nm is preferably 50% or more.

  As described above, it is difficult to form a filter using an organic solvent as a solvent for a visible light absorbing dye having a wavelength of 570 to 610 nm in the sense of minimizing atmospheric and working environment regulations, explosion prevention, and environmental impact. There was a problem that required capital investment. On the other hand, the method of forming a visible light absorbing dye layer of 570 to 610 nm using a water-soluble solvent-dispersible dye and gelatin can avoid these problems, but the durability of the dye. There was an inferior problem. That is, there was a problem in practical use regardless of which one was used. However, a polymer dispersion dispersed in an aqueous dispersion medium can solubilize or disperse a visible light absorbing pigment of 570 to 610 nm, and a filter obtained from the composition uses a dye having a hydrophilic group. It is a major feature of the present invention that it has been found that the above-mentioned durability defect of the dye does not occur.

The filter of the present invention can be produced by applying a coating composition containing a visible light absorbing dye having a wavelength of 570 to 610 nm, a solvent, a resin, and the like described below onto a support.
As a method for applying the visible light absorbing layer, for example, a dip coating method, a roller coating method, a spray coating method, a gravure coating method, a die coating method, a bar coating method, or the like can be selected. These coating methods can perform continuous processing, and are more productive than batch-type vapor deposition methods. Also, a spin coating method that can form a thin and uniform coating film can be employed.
Application to a support (for example, a plastic film such as polyester, which will be described later) applied to a support layer is performed before sequential biaxial stretching, before simultaneous biaxial stretching, after uniaxial stretching, before re-stretching, or after biaxial stretching. Any of these may be used. The surface of the plastic support to which the coating solution is applied is preferably subjected to surface treatment such as ultraviolet irradiation treatment, corona discharge treatment, glow discharge treatment, etc. in advance.

(1) Dye having maximum absorption at 570 to 610 nm The dye having the maximum absorption at 570 to 610 nm applied to the present invention is a dye that can be stably dissolved or dispersed in an aqueous dispersion of a polymer. If it is dye which has, it can become an object of application.
Two or more visible light absorbing layers having a wavelength of 570 to 610 nm may be provided.
The film thickness of the visible light absorbing layer of 570 to 610 nm is preferably 0.1 μm or more in order to effectively obtain the visible light absorbing effect of 570 to 610 nm, and the film forming operation is such that the solvent during film formation hardly remains. The thickness is preferably 20 μm or less from the viewpoint of easy properties. In particular, the thickness is preferably 0.2 to 10 μm.

Examples of the dye having a maximum absorption at 570 to 610 nm used in the present invention include cyanine, squarylium, anthraquinone, phthalocyanine, porphyrin, tetraazaporphyrin, polymethine, azomethine, azurenium, and diphenylmethane. Among organic pigments such as triphenylmethane, dibenzofuranone, diketopyrrolopyrrole, rhodamine, xanthene, pyromethene, quinacridone, oxonol, oxazine, styryl, coumarin, etc. The dye which has can be used preferably. Those preferably used in the present invention are preferably cyanine, squarylium, anthraquinone, tetraazaporphyrin, and pyromethene, more preferably cyanine, squarylium, tetraazaporphyrin, and pyromethene, and most preferably cyanine.
Examples of cyanine dyes include monomethine cyanine dyes, trimethine cyanine dyes, and menthamethine cyanine dyes, among which trimethine cyanine dyes are preferable, and the cyclic groups of cyanine dyes are oxazole rings, thiazole rings, indolenine rings, Those having an imidazolium ring are preferred.
These dyes preferably have a water-soluble group. Examples of the water-soluble group include a carboxyl group and a salt thereof, a sulfo group and a salt thereof, and the like.
Furthermore, the water-soluble dye suitably used in the present invention is preferable from the viewpoint of environmental influences and from the viewpoint of reducing the coating cost in that it can be applied as an aqueous solution or an aqueous dispersion without dissolving in an organic solvent. .

These dyes are preferably used as aggregates, and particularly preferably used as J aggregates. By using a J aggregate, first, the absorption waveform becomes sharp and suitable for selectively cutting the emission peak around 590 nm. Second, the heat resistance, moisture heat resistance, light resistance, etc. of the dye are suitable. Durability can be improved, and thirdly, there is an advantage that the amount of dye used can be reduced because the absorbance increases.
It is also a preferred form to use these dyes by adjusting the water-solubility and making them insoluble, or in other words, a rake dye and making the dye into an aqueous dispersion. This also makes it possible to improve the durability of the dye, such as heat resistance, moist heat resistance, and light resistance, which is preferable. On the other hand, it is difficult to sharpen the absorption waveform, and it is more preferable to use a water-soluble dye than to use a lake dye in terms of the sharpness of the absorption waveform.
As these dyes having maximum absorption at 570 to 610 nm, dyes described in JP-A-2001-228324 can be used.

  In order to obtain the effect effectively, the amount of the dye having the maximum absorption at 570 to 610 nm is preferably 0.001% by mass or more with respect to the polymer contained in the aqueous dispersion of the polymer. 05 mass% or more is preferable. Moreover, in order to maintain the physical properties of the polymer layer obtained from the aqueous dispersion of the polymer, it is preferable to suppress the amount of the dye having the maximum absorption at 570 to 610 nm to 10% by mass or less.

  In addition, for example, the plasma display panel has a high panel surface temperature, and particularly when the environmental temperature is high, the temperature of the visible light absorbing filter of 570 to 610 nm also rises. It preferably has heat resistance that does not deteriorate. In addition to heat resistance, some dyes have poor light resistance. If degradation of the plasma display light emission or external light due to ultraviolet or visible light becomes a problem, use a member containing an ultraviolet absorber or a member that does not transmit ultraviolet light, or use an ultraviolet absorber and an aqueous dispersion of a polymer together with a visible light absorbing dye. It is important to reduce the deterioration of the dye due to ultraviolet rays by using it in the product, or to use a dye that does not significantly deteriorate due to ultraviolet rays or visible light. The same applies to humidity and a combined environment in addition to heat and light. When it deteriorates, the transmission characteristics of the visible light absorbing filter of 570 to 610 nm change, and the color tone changes or the visible light absorbing ability of 570 to 610 nm decreases. Furthermore, in order to disperse in a medium or a coating film, solubility and dispersibility in an appropriate solvent are also important. In the present invention, two or more kinds of dyes having different absorption wavelengths may be contained in one medium or a coating film, or two or more mediums and coating films containing a pigment may be included.

  The visible light absorbing filter having a wavelength of 570 to 610 nm is preferably imparted with an ultraviolet cutting property for the purpose of preventing deterioration of the visible light absorbing dye having a wavelength of 570 to 610 nm. As the ultraviolet ray cutting ability necessary for protecting the dye, the transmittance in the ultraviolet region shorter than the wavelength of 380 nm is 20% or less, preferably 10% or less, more preferably 5% or less. The ultraviolet cut property can be obtained by forming a layer containing an ultraviolet absorber or an inorganic compound that reflects or absorbs ultraviolet rays on a transparent substrate. It is also preferable to make it contain in the aqueous dispersion of a polymer. Conventionally known UV absorbers such as benzotriazoles and benzophenones can be used, and their types and concentrations are dispersibility / solubility in the medium to be dispersed or dissolved, absorption wavelength / absorption coefficient, thickness of the medium. It is determined from the above and is not particularly limited.

  In addition, it is preferable that the visible light absorptive filter which has ultraviolet-cutting property has little absorption of a visible light region, and a visible light transmittance | permeability does not fall remarkably or exhibits colors, such as yellow.

  Examples of ultraviolet absorbers that can be preferably used in the present invention include those disclosed in JP-A Nos. 58-185677, 61-190537, JP-A-2-782, JP-A-5-97075, and JP-A-9-34057. The described benzotriazole compounds, benzophenone compounds described in JP-A No. 46-2784, JP-A No. 5-194443, US Pat. No. 3,214,463, etc., JP-B No. 48-30492, No. 56- 21141, JP-A-10-88106, etc., cinnamic acid compounds, JP-A-4-298503, 8-53427, 8-239368, 10-182621, The triazine compounds described in JP-T-8-501291 and the like, Research Disclosure No. Compounds described in No. 24239, compounds that emit fluorescence by absorbing ultraviolet rays typified by stilbene-based compounds and benzoxazole-based compounds, so-called fluorescent brighteners, can also be used.

  In the present invention, an antioxidant is preferably used for improving the stability of the dye, and various organic and metal complex antifading agents can be used as the antioxidant. Organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, etc. Complex, zinc complex and the like. More specifically, Research Disclosure No. No. 17643, No. VII, I to J, ibid. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544, page 527, ibid. No. 307105, page 872, ibid. The compounds described in the patent cited in No. 15162 and the compounds included in the general formulas and compound examples of the representative compounds described in pages 127 to 137 of JP-A-62-215272 can be used.

(2) Aqueous Polymer Dispersion The aqueous polymer dispersion used in the present invention is a dispersion in which a synthetic resin is dispersed in a dispersion medium whose main component is water (sometimes referred to herein as an aqueous solvent). It is.
The content of water contained in the aqueous solvent is preferably 30% by mass to 100% by mass, and more preferably 50% by mass to 100% by mass. As the solvent other than water, a solvent having solubility in water such as alcohols such as methanol, ethanol and isopropyl alcohol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran and butyl cellosolve is preferably used.
As the synthetic resin (polymer), various polymers such as an acrylic resin, a vinyl resin, a polyurethane resin, and a polyester resin can be used. The synthetic resin (polymer) layer is crosslinked by a crosslinking agent (for example, a carbodiimide compound). It was found that the cross-linking not only improved the adhesion to the support, but also unexpectedly improved the light resistance of the visible light absorbing filter of 570-610 nm. This is another major feature of the present invention. In the present invention, from the viewpoint of maintaining a good working environment and preventing air pollution, it is preferable to use both a polymer and a curing agent such as a carbodiimide compound in an aqueous dispersion state in an emulsion form. Moreover, it is preferable that a polymer has any group of a methylol group, a hydroxyl group, a carboxyl group, and an amino group so that a crosslinking reaction with hardening | curing agents, such as a carbodiimide compound, is possible. Of these, a hydroxyl group and a carboxyl group are preferable, and a carboxyl group is particularly preferable. The content of the hydroxyl group or carboxyl group in the polymer is preferably 0.0001 to 1 equivalent / kg, particularly preferably 0.001 to 1 equivalent / kg.

  Acrylic resins include acrylic acid esters such as acrylic acid and alkyl acrylate, acrylamide, acrylonitrile, methacrylic acid esters such as methacrylic acid and alkyl methacrylate, and homopolymers of any monomer of methacrylamide and methacrylonitrile. Or the copolymer obtained by superposition | polymerization of 2 or more types of these monomers can be mentioned. Among these, homopolymers of monomers of acrylic acid esters such as alkyl acrylates and methacrylic acid esters such as alkyl methacrylates, or copolymers obtained by polymerization of two or more of these monomers preferable. For example, mention may be made of homopolymers of monomers of acrylic acid esters and methacrylic acid esters having an alkyl group having 1 to 6 carbon atoms, or copolymers obtained by polymerization of two or more of these monomers. it can. The acrylic resin has the above composition as a main component and, for example, partially uses a monomer having any group of a methylol group, a hydroxyl group, a carboxyl group, and an amino group so that a crosslinking reaction with a carbodiimide compound is possible. The resulting polymer.

  Examples of the vinyl resin include polyvinyl formal, polyvinyl butyral, polyvinyl methyl ether, polyolefin, ethylene / butadiene copolymer, polyvinyl acetate, vinyl chloride / vinyl acetate copolymer, vinyl chloride / (meth) acrylic acid ester copolymer. And an ethylene / vinyl acetate copolymer (preferably ethylene / vinyl acetate / (meth) acrylic acid ester copolymer). Among these, polyvinyl alcohol, acid-modified polyvinyl alcohol, polyvinyl polymer, polyolefin, ethylene / butadiene copolymer and ethylene / vinyl acetate copolymer (preferably ethylene / vinyl acetate / acrylic acid ester copolymer). Is preferred. The vinyl resin can be crosslinked with a carbodiimide compound so that, for example, polyvinyl alcohol, acid-modified polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyvinyl methyl ether, and polyvinyl acetate leave a vinyl alcohol unit in the polymer. Thus, the polymer having a hydroxyl group is used, and the other polymer is, for example, a crosslinkable polymer by partially using a monomer having any of a methylol group, a hydroxyl group, a carboxyl group, and an amino group.

  Examples of the polyurethane resin include polyhydroxy compounds (eg, ethylene glycol, propylene glycol, glycerin, trimethylolpropane), aliphatic polyester polyols obtained by reaction of polyhydroxy compounds and polybasic acids, polyether polyols (eg, Polyurethane derived from poly (oxypropylene ether) polyol, poly (oxyethylene-propylene ether) polyol), polycarbonate-based polyol, and polyethylene terephthalate polyol, or a mixture thereof and polyisocyanate can be given. In the polyurethane resin, for example, the hydroxyl group remaining unreacted after the reaction between polyol and polyisocyanate can be used as a functional group capable of crosslinking reaction with a carbodiimide compound.

  As the polyester resin, generally used is a polymer obtained by reacting a polyhydroxy compound (eg, ethylene glycol, propylene glycol, glycerin, trimethylolpropane) with a polybasic acid. In the polyester resin, for example, after the reaction between the polyol and the polybasic acid is completed, the hydroxyl group and carboxyl group remaining unreacted can be used as a functional group capable of crosslinking reaction with the carbodiimide compound. Of course, a third component having a functional group such as a hydroxyl group may be added.

  Among the above polymers, acrylic resins and polyurethane resins are preferable, and acrylic resins are particularly preferable.

In the present invention, the support has a polymer layer obtained from a dye having an absorption maximum at 570 to 610 nm and an aqueous dispersion of the polymer on the support, and the water-soluble polymer content in the polymer layer is expressed by mass ratio. It is preferably 0 to 50%, and more preferably 0 to 10%. Here, the water-soluble polymer includes, for example, gelatin, polyvinyl alcohol, polyvinyl pyrrolidone, carboxymethyl cellulose, and the like, and refers to a polymer that dissolves in water of 40% by mass or more.
In the present invention, it is more preferable that the water-soluble polymer is not substantially contained, and it means that the water-soluble polymer mass ratio in the polymer layer obtained from the aqueous dispersion of the polymer is 3% or less. It shows that there is.

The crosslinking agent used in the present invention will be further described.
As the carbodiimide compound which is a crosslinking agent particularly preferably used in the present invention, a compound having a plurality of carbodiimide structures in the molecule is preferably used.
Polycarbodiimide is usually synthesized by a condensation reaction of organic diisocyanate. Here, the organic group of the organic diisocyanate used for the synthesis of the compound having a plurality of carbodiimide structures in the molecule is not particularly limited, and either aromatic or aliphatic, or a mixed system thereof can be used. An aliphatic system is particularly preferred from the viewpoint of reactivity.
As the synthetic raw material, organic isocyanate, organic diisocyanate, organic triisocyanate and the like are used.
As examples of organic isocyanates, aromatic isocyanates, aliphatic isocyanates, and mixtures thereof can be used.
Specifically, 4,4′-diphenylmethane diisocyanate, 4,4-diphenyldimethylmethane diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, cyclohexane Diisocyanate, xylylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 1,3-phenylene diisocyanate, etc. are used. As organic monoisocyanates, isophorone isocyanate, phenyl isocyanate are used. Cyclohexyl isocyanate, butyl isocyanate, naphthyl isocyanate and the like are used.
Moreover, the carbodiimide compound which can be used for this invention is also available as commercial items, such as carbodilite V-02-L2 (brand name: Nisshinbo Co., Ltd. product).
The carbodiimide compound is preferably added in an amount of 1 to 200% by mass, more preferably 5 to 100% by mass with respect to the binder (the above-mentioned resin and a water-soluble polymer used in combination as required).

As the other crosslinking agent, an epoxy compound can be preferably used.
Examples of the epoxy compound include 1,4-bis (2 ′, 3′-epoxypropyloxy) butane, 1,3,5-triglycidyl isocyanurate, 1,3-diglycidyl-5- (γ-acetoxy-β-oxy Propyl) isosinurate, sorbitol polyglycidyl ethers, polyglycerol polyglycidyl ethers, pentaerythritol polyglycidyl ethers, diglycerol polyglycidyl ether, 1,3,5-triglycidyl (2-hydroxyethyl) isocyanurate, glycerol poly Epoxy compounds such as glycerol ethers and trimethylolpropane polyglycidyl ethers are preferred, and specific examples of commercially available products include Denacol EX-521 and EX-614B (manufactured by Nagase Chemical Industries). Although it is not intended to be limited thereto.

  Further, it can be used in combination with other crosslinkable compounds, for example, “The Theory of the Photographic Process” by CEKMees and TH James, 3rd edition (1966), US Pat. No. 2,732,303, No. 3,635,718, No. 3,323,763, No. 2,732,316, No. 2,586,168, No. 3,103,437, No. 30,17280, No. 2,983611, No. 2,725,294, No. 2,725,295, No. 3,100,704, No. 3091537, Examples thereof include curing agents described in JP-A Nos. 3321313, 3543292, and 3125449, and British Patent Nos. 994869 and 1167207.

  As a typical example, a melamine compound containing at least one of two or more (preferably three or more) methylol groups and an alkoxymethyl group or a condensation polymer thereof, a melamine resin or a melamine urea resin, Mucochloric acid, mucobromic acid, mucofenoxycyclolic acid, mucophenoxypromic acid, formaldehyde, glyoxal, monomethylglioxal, 2,3-dihydroxy-1,4-dioxane, 2,3-dihydroxy-5-methyl-1,4 Aldehyde compounds such as dioxane succinaldehyde, 2,5-dimethoxytetrahydrofuran and glutaraldehyde and derivatives thereof; divinylsulfone-N, N′-ethylenebis (vinylsulfonylacetamide), 1,3-bis (vinylsulfonyl) -2 − Lopanol, methylene bismaleimide, 5-acetyl-1,3-diaacryloyl-hexahydro-s-triazine, 1,3,5-triacryloyl-hesahydro-s-triazine and 1,3,5-trivinylsulfonyl-hexahydro- active vinyl compounds such as s-triazine; 2,4-dichloro-6-hydroxy-s-triazine sodium salt, 2,4-dichloro-6- (4-sulfoanilino) -s-triazine sodium salt, 2,4- Active halogen compounds such as dichloro-6- (2-sulfoethylamino) -s-triazine and N, N′-bis (2-chloroethylcarbamyl) piperazine; bis (2,3-epoxypropyl) methylpropylammonium P-toluenesulfonate, 2,4,6-triethylene-s-triazine, Ethyleneimine compounds such as 1,6-hexamethylene-N, N′-bisethyleneurea and bis-β-ethyleneiminoethylthioether; 1,2-di (methanesulfoneoxy) ethane, 1,4-di (methanesulfone) Oxy) butane and methanesulfonic acid ester compounds such as 1,5-di (methanesulfoneoxy) pentane; carbodiimide compounds such as dicyclohexylcarbodiimide and 1-dicyclohexyl-3- (3-trimethylaminopropyl) carbodiimide hydrochloride; Isoxazole compounds such as 5-dimethylisoxazole; inorganic compounds such as chromium alum and chromium acetate; N-carboethoxy-2-isopropoxy-1,2-dihydroquinoline and N- (1-morpholinocarboxy)- 4-methylpyridinium chloride, etc. Dehydrated condensation type peptide reagents; active ester compounds such as N, N′-adipoyldioxydisuccinimide and N, N′-terephthaloyldioxydisuccinimide: toluene-2,4-diisocyanate and 1,6- Examples thereof include, but are not limited to, isocyanates such as hexamethylene diisocyanate; and epichlorohydrin compounds such as polyamide-polyamine-epichlorohydrin reactant.

Other useful crosslinking agents include, for example, active vinyl compounds (1,3,5-triacryloyl-hexahydro-s-triazine, bis (vinylsulfonylmethyl) ether, N, N'-methylenebis- [β- (vinylsulfonyl ) Propionamide], etc.), active halogen compounds (mucohalic acid represented by mucochloric acid), and haloamidinium salts (1- (1-chloro-1-pyridinomethylene) pyrrolidinium-2-naphthalenesulfonate, etc.) alone Or they can be used in combination. Further, active vinyl compounds described in JP-A-53-41220, JP-A-53-57257, JP-A-59-162546, JP-A-60-80846, and the like, and U.S. Pat. No. 3,325,287. The active halogen compounds are also preferred.
The above various crosslinking agents can also be used in the same amount as described for the carbodiimide compound.

(3) Support As the support used in the present invention, a transparent substrate such as a plastic film, a plastic plate, and a glass plate can be used.
Examples of the raw material for the plastic film and the plastic plate include: polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate; polyolefins such as polyethylene (PE), polypropylene (PP), polystyrene, and EVA; Vinyl resins such as polyvinylidene chloride; polyether ether ketone (PEEK), polysulfone (PSF), polyether sulfone (PES), polycarbonate (PC), polyamide, polyimide, acrylic resin, triacetyl cellulose (TAC) Etc. can be used.
In the present invention, the plastic film is preferably a polyethylene terephthalate film or triacetyl cellulose (TAC) from the viewpoints of transparency, heat resistance, ease of handling, and price.

Since the visible light absorption filter for display requires transparency, it is desirable that the support has high transparency. In this case, the total visible light transmittance of the plastic film or plastic plate is preferably 70 to 100%, more preferably 85 to 100%, and particularly preferably 90 to 100%. Moreover, in this invention, what was colored to such an extent that the objective of this invention is not disturbed can also be used as the said plastic film and a plastic board.
The plastic film and plastic plate in the present invention can be used as a single layer, but can also be used as a multilayer film in which two or more layers are combined.

  When a glass plate is used as the support in the present invention, the type thereof is not particularly limited. However, when used as an application for an electromagnetic wave shielding film for a display, it is preferable to use tempered glass having a tempered layer on the surface. There is a high possibility that tempered glass can prevent breakage compared to glass that has not been tempered. Furthermore, the tempered glass obtained by the air cooling method is preferable from the viewpoint of safety because even if it is broken, the crushed pieces are small and the end face is not sharp.

(4) Electromagnetic wave shielding layer The visible light absorbing filter of the present invention preferably has a conductive pattern containing metallic silver. By making this conductive pattern into a lattice shape made of fine lines, it can be used as an optical filter for display having an electromagnetic wave shielding function.
The conductive pattern containing metallic silver can be formed by printing a paste or ink comprising fine silver particles in a pattern, and development obtained by developing a film coated with a silver halide emulsion. It can be formed by using silver. The electroconductive pattern containing these silver can improve electromagnetic wave shielding capability by performing a plating process and improving electroconductivity.

(5) Other functional layers In the present invention, if necessary, further functionality may be imparted to the visible light absorbing layer. Alternatively, a functional layer having functionality may be provided separately from the layer. This functional layer can have various specifications for each application. For example, as an electromagnetic shielding material for a display, an antireflection layer provided with an antireflection function by adjusting a refractive index or a film thickness, a non-glare layer or an antiglare layer (both have a glare prevention function), a specific wavelength region Layers that have a color tone adjustment function that absorbs visible light, antifouling layers that have the ability to easily remove dirt such as fingerprints, hard-coat layers that are difficult to scratch, layers that have an impact absorption function, and glass scattering when glass is broken A layer having a prevention function or the like can be provided. These functional layers may be provided on the opposite side of the silver salt-containing layer and the support, or may be provided on the same side.
These functional films may be directly bonded to the PDP, or may be bonded to a transparent substrate such as a glass plate or an acrylic resin plate separately from the plasma display panel main body. These functional films are called optical filters (or simply filters).

(Anti-reflection and anti-glare properties)
The translucent electromagnetic wave shielding film has anti-reflection (AR: anti-reflection) properties to suppress external light reflection, or anti-glare (AG: anti-glare) properties to prevent reflection of mirror images, or both characteristics. It is preferable to provide any of the antireflection antiglare (ARAG) properties provided.
With these performances, it is possible to prevent the display screen from becoming difficult to see due to the reflection of a lighting fixture or the like. Further, by reducing the visible light reflectance of the film surface, not only the reflection can be prevented but also the contrast and the like can be improved. When a functional film having antireflection properties and antiglare properties is attached to a visible light absorption filter, the visible light reflectance is preferably 2% or less, more preferably 1.3% or less, and still more preferably 0. .8% or less.

The functional film as described above can be formed by providing a functional layer having antireflection properties and antiglare properties on a suitable transparent substrate.
As the antireflection layer, for example, a fluorine-based transparent polymer resin, magnesium fluoride, a silicon-based resin, a thin film of silicon oxide, etc., which is formed as a single layer with an optical film thickness of 1/4 wavelength, for example, having a different refractive index, It may be formed of a multi-layered laminate of thin films of inorganic compounds such as metal oxides, fluorides, silicides, nitrides, sulfides, or organic compounds such as silicon resins, acrylic resins, and fluorine resins. it can.

The antiglare layer can be formed from a layer having a minute uneven surface state of about 0.1 μm to 10 μm. Specifically, acrylic resin, silicon resin, melamine resin, urethane resin, alkyd resin, thermosetting resin such as fluorine resin, photocurable resin, silica, organosilicon compound, melamine, acrylic, etc. It is possible to form by coating and curing an ink in which particles of the inorganic compound or organic compound are dispersed.
The average particle size of the particles is preferably about 1 to 40 μm.
Further, the antiglare layer can also be formed by applying the thermosetting or photocurable resin described above and then pressing and curing a mold having a desired gloss value or surface state.
When the antiglare layer is provided, the haze of the visible light absorption filter is preferably 0.5% or more and 20% or less, more preferably 1% or more and 10% or less. If the haze is too small, the antiglare property is insufficient, and if the haze is too large, the transmitted image sharpness tends to be low.

(Hard coat property)
In order to add scratch resistance to the visible light absorption filter, it is also preferable that the functional film has a hard coat property. Examples of the hard coat layer include acrylic resins, silicon resins, melamine resins, urethane resins, alkyd resins, and thermosetting resins such as fluorinated resins. There is no particular limitation. The thickness of the hard coat layer is preferably about 1 to 50 μm. When the antireflection layer and / or the antiglare layer is formed on the hard coat layer, a functional film having scratch resistance, antireflection property and / or antiglare property is preferably obtained.
As for the surface hardness of the visible light absorption filter to which hard coat properties are imparted, the pencil hardness according to JIS (K-5400) is preferably at least H, more preferably 2H, and even more preferably 3H or more.

(Antistatic property)
In order to prevent dust adhesion due to electrostatic charging and electrostatic discharge due to contact with the human body, it is preferable that the visible light absorption filter is provided with antistatic properties.
As the functional film having antistatic properties, a film having high electrical conductivity can be used. For example, the electrical conductivity may be about 10 ¹¹ Ω / □ or less in terms of surface resistance.
A highly conductive film can be formed by providing an antistatic layer on a transparent substrate. Specific examples of the antistatic agent used in the antistatic layer include trade name Pelestat (manufactured by Sanyo Kasei Co., Ltd.), trade name electro slipper (manufactured by Kao Corporation), and the like. In addition, the antistatic layer may be formed of a known transparent conductive film such as ITO, or a conductive film in which conductive ultrafine particles such as ITO ultrafine particles and tin oxide ultrafine particles are dispersed. Antistatic properties may be imparted to the above hard coat layer, antireflection layer, antiglare layer and the like by adding conductive fine particles.

(Anti-fouling property)
It is preferable that the visible light absorption filter has antifouling property because it can prevent fingerprints and the like and can be easily removed when they are attached.
The functional film having antifouling properties can be obtained, for example, by applying a compound having antifouling properties on a transparent substrate. The compound having antifouling property may be a compound having non-wetting property with respect to water and / or fats and oils, and examples thereof include fluorine compounds and silicon compounds. Specific examples of the fluorine compound include trade name Optool (manufactured by Daikin), and examples of the silicon compound include trade name Takata Quantum (manufactured by Nippon Oil & Fats Co., Ltd.).

(UV-cutting property)
The visible light absorbing filter is preferably imparted with UV-cutting properties for the purpose of preventing the deterioration of the dye and transparent substrate described later. The functional film having ultraviolet cut-off property can be formed by a method in which the transparent substrate itself contains an ultraviolet absorber or by providing an ultraviolet absorbing layer on the transparent substrate.
As the ultraviolet ray cutting ability necessary for protecting the dye, the transmittance in the ultraviolet region shorter than the wavelength of 380 nm is 20% or less, preferably 10% or less, more preferably 5% or less. A functional film having an ultraviolet cutting property can be obtained by forming a layer containing an ultraviolet absorber or an inorganic compound that reflects or absorbs ultraviolet rays on a transparent substrate. Conventionally known UV absorbers such as benzotriazole and benzophenone can be used, and their types and concentrations are dispersibility / solubility in the medium to be dispersed or dissolved, absorption wavelength / absorption coefficient, thickness of the medium. It is determined from the above and is not particularly limited.

In addition, it is preferable that the functional film which has ultraviolet cut-off property has little absorption of visible light region, and does not show visible light transmittance | permeability remarkably or exhibit colors, such as yellow.
Moreover, when the layer containing the pigment | dye mentioned later is formed in the functional film, it is desirable that the layer which has ultraviolet-cutting property exists outside the layer.

(Gas barrier properties)
When the visible light absorption filter is used in a temperature / humidity environment higher than normal temperature and humidity, the pigment described later deteriorates due to moisture, or the moisture aggregates in the adhesive used for bonding and the bonding interface, and becomes cloudy. Since the adhesive may phase-separate and precipitate and become cloudy due to the influence of moisture, the translucent electromagnetic wave shielding film preferably has a gas barrier property.
In order to prevent such pigment deterioration and fogging, it is important to prevent moisture from entering the pigment-containing layer and the adhesive layer, and the water vapor permeability of the functional film is 10 g / m ² · day or less, Preferably it is 5 g / m ² · day or less.

(Other optical properties)
Moreover, when using a visible light absorption filter for a plasma display, it is preferable that the transmitted color is neutral gray or blue gray. This is because the light emission characteristics and contrast of the plasma display are maintained or improved, and white having a slightly higher color temperature than standard white may be preferred.

  Further, the optical filter used in the plasma display is required to have a transmission color of neutral gray or blue gray. This is because it is necessary to maintain or improve the light emission characteristics and contrast of the plasma display, and a white having a slightly higher color temperature than the standard white may be preferred. Furthermore, it is said that a color plasma display has insufficient color reproducibility, and it is preferable to selectively reduce unnecessary light emission from the phosphor or discharge gas which is the cause. In particular, the emission spectrum of red display shows several emission peaks ranging from about 580 nm to about 700 nm, and the emission intensity on the short wavelength side is relatively strong and the red emission is not good in color purity close to orange. There is a problem. These optical properties can be controlled by using a dye. In other words, a near-infrared absorber is used for near-infrared cut, and a dye that selectively absorbs unnecessary luminescence is used to reduce unwanted luminescence. The color tone can also be made suitable by using a dye having appropriate absorption in the visible region.

  As a method of containing a dye, (1) at least one kind of dye, a polymer film or a resin plate kneaded with a transparent resin, (2) at least one kind of dye, resin or resin monomer / organic system A polymer film or resin plate dispersed and dissolved in a solvent concentrate of a solvent and prepared by a casting method. (3) At least one dye is added to a resin binder and an organic solvent to form a paint, a polymer film or Any one or more of those coated on a resin plate and (4) a transparent adhesive material containing at least one pigment can be selected, but the invention is not limited thereto. The term “inclusion” as used in the present invention means that it is contained in a layer such as a base material or a coating film or an adhesive material, and of course, is applied to the surface of the base material or layer.

  The above dye is a general dye or pigment having a desired absorption wavelength in the visible region, and the type thereof is not particularly limited. For example, anthraquinone, phthalocyanine, methine, azomethine, and oxazine , Imonium, azo, styryl, coumarin, porphyrin, dibenzofuranone, diketopyrrolopyrrole, rhodamine, xanthene, pyromethene, dithiol and diiminium compounds are also commercially available. Organic dyes are included. The type / concentration is determined by the absorption wavelength / absorption coefficient of the dye, the transmission characteristics / transmittance required for the optical filter, and the type / thickness of the medium or coating film to be dispersed, and is not particularly limited.

  The conductive portion may be a mesh pattern layer or an unpatterned layer of metal foil, for example, but the metal foil solid layer may be used for good electrical contact with the ground portion of the display body. It is preferable that the conductive portion is not patterned like a layer.

  For example, when the conductive part is not patterned like a solid metal foil and / or when the conductive part has a sufficiently strong mechanical strength, the conductive part itself can be used as an electrode.

In order to protect the conductive part and / or to make good electrical contact with the ground part when the conductive part is a mesh pattern layer, it may be preferable to form an electrode on the conductive part. The electrode shape is not particularly limited, but is preferably formed so as to cover all the conductive portions.
The material used for the electrode is a single or a combination of two or more of silver, copper, nickel, aluminum, chromium, iron, zinc, carbon, etc. in terms of conductivity, resistance to contact and adhesion to a transparent conductive film. Alternatively, a paste made of a synthetic resin and a mixture of these simple substances or alloys, or a paste made of a mixture of borosilicate glass and these simple substances or alloys can be used. Conventionally known methods can be employed for printing and coating the paste. Moreover, a commercially available conductive tape can also be used conveniently. The conductive tape has conductivity on both sides, and a single-sided adhesive type and a double-sided adhesive type using a carbon-dispersed conductive adhesive can be suitably used. The thickness of the electrode is not particularly limited, but is about several μm to several mm.

  The features of the present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[Production of visible light absorbing filter of 570 to 610 nm]
(Preparation of a dye composition having an absorption maximum at 570 to 610 nm)
0.2 parts by weight of trimethine cyanine dye (I-1) as a first dye, 100 parts by weight of water, and a polymer emulsion (aqueous dispersion of acrylic resin) manufactured by Nippon Pure Chemical Co., Ltd .; Jurimer ET-410: The visible light absorptive composition A which mixed 100 mass parts was created.
Trimethine dye (I-1)

  Trimethine dye (I-2)

  Trimethine dye (I-3)

(Coating of a dye composition having an absorption maximum at 570 to 610 nm)
A filter layer (Comparative Sample 101) was prepared by laminating a PET resin film (thickness: 96 μm) manufactured by FUJIFILM with 41 ml / m ² of the visible light absorbing composition A and a dye layer having an absorption maximum at 587 mm. A minimum transmittance of 570 to 610 nm (40%) was obtained.
Moreover, the visible light absorptive composition which mixed 3 mass parts of epoxy-type crosslinking agents (hardening agent; Denacol EX614B) with the said composition A was prepared, and the filter 102 of this invention was created similarly to the above ( (Minimum transmittance of 570 to 610 nm 41%). Further, a visible light absorbing composition prepared by mixing 13 parts by mass of a carbodiimide-based crosslinking agent (Nisshinbo Co., Ltd., carbodilite) with the composition A was prepared, and the filter 103 of the present invention was prepared in the same manner as above (570) (Minimum transmittance of ˜610 nm 39%).

(Preparation of comparative sample 104)
A comparative sample 104 was prepared in the same manner as described above except that the above dye was dissolved in an aqueous gelatin solution, which is a water-soluble polymer, instead of the polymer dispersion. 43%).

(Evaluation of visible light absorption ability)
The transmittance was measured using a spectrometer U-3500 manufactured by Hitachi, Ltd.

(Evaluation of heat and humidity resistance)
The sample was stored at 80 ° C. and 90% relative humidity for 4 days, and the transmittance at 587 nm was measured. A case where the change in the transmittance was remarkable (5% or more) was evaluated as x, and a case where the transmittance was hardly changed was evaluated as ◯.
(Evaluation of light resistance)
The sample was irradiated with light from a xenon lamp and stored for 4 days, and the transmittance at 587 nm was measured. The case where the change in the transmittance was remarkable was evaluated as x, and the case where the transmittance was hardly changed was evaluated as ◯.
(Evaluation of adhesion)
After the Nitto Denko adhesive tape and the coated surface of the above sample were bonded together, both were peeled off to evaluate the degree of adhesion of the applied product to the adhesive tape. The case where a large amount was adhered was evaluated as x, and the case where almost no adhesion was observed was evaluated as ◯.

From the above results, it can be seen that Samples 101 to 103 using a polymer emulsion as a binder are excellent in heat and moisture resistance. On the other hand, the comparative sample 104 using gelatin, which is a water-soluble polymer, as a binder has a problem in stability as a visible light absorption filter because its transmittance increases under wet heat conditions.
In addition, the samples 102 and 103 of the present invention using a cross-linking agent are superior in adhesion to the samples 101 and 104 not using a cross-linking agent, and surprisingly, light resistance is remarkable due to the use of the cross-linking agent. It can be seen that
In addition, as described above, it is not necessary to use a volatile organic solvent as a solvent in the present invention, so that it is understood that there is no problem in terms of environmental safety. Further, the visible light absorbing layer is produced by dispersing the coating composition by water dispersion, and is provided on the support by a coating method, whereby a realistic production cost is achieved.
In addition, when the same evaluation was performed by changing the dye (I-1) to (I-2) and (I-3), the same result as above was obtained.
The filter 102 is prepared by using an anionic surfactant as the aqueous dispersion of the dye (I-4) in which both the N-position and N′-position sulfobutyl groups of the dye (I-1) are changed to methyl groups. When the filter was prepared in the same manner as described above, the same results were obtained in terms of wet heat resistance and light resistance, but there was a problem that absorption at 570 to 610 nm was broad and haze was high. .

Claims (15)

  On a support, it has a polymer layer obtained from a dye having an absorption maximum at 570 to 610 nm and an aqueous dispersion of the polymer, and the polymer layer is crosslinked with a crosslinking agent. A visible light absorbing filter having a minimum value of transmittance.   2. The visible light absorbing filter having a minimum value of transmittance at 570 to 610 nm according to claim 1, wherein the mass ratio of the water-soluble polymer in the polymer layer is 0 to 50%.   The visible light absorptive filter having a minimum value of transmittance at 570 to 610 nm according to claim 1 or 2, wherein the polymer layer has a water-soluble polymer mass ratio of 10% or less.   The minimum value of transmittance at 570 to 610 nm according to any one of claims 1 to 3, wherein the crosslinking agent contains at least a carbodiimide compound, an epoxy compound, an active vinyl compound, an active halogen compound, or a haloamidinium salt. A visible light absorbing filter.   The visible light absorbing filter having a minimum transmittance at 570 to 610 nm according to any one of claims 1 to 4, wherein the dye having an absorption maximum at 570 to 610 nm has a water-soluble group.   The visible light-absorbing filter having a minimum value of transmittance at 570 to 610 nm according to any one of claims 1 to 5, wherein the aqueous polymer dispersion contains an acrylic resin.   The visible light absorbing filter having a minimum value of transmittance at 570 to 610 nm according to any one of claims 1 to 6, wherein the support is a transparent plastic film.   The visible light absorptive filter having a minimum value of transmittance at 570 to 610 nm according to any one of claims 1 to 7, wherein the transmittance of light at 590 nm is 60% or less.   The visible light absorptive filter which has the minimum value of the transmittance | permeability in 570-610 nm in any one of Claims 1-8 characterized by containing a near-infrared absorptive dye.   The visible light absorption filter having a minimum value of transmittance at 570 to 610 nm according to any one of claims 1 to 9, wherein the visible light absorption filter has a conductive pattern made of metal.   The visible light absorption filter having a minimum value of transmittance at 570 to 610 nm according to claim 10, wherein the visible light absorption filter has a conductive pattern containing metallic silver.   The visible light absorption filter having a minimum value of transmittance at 570 to 610 nm according to claim 10 or 11, wherein the conductive pattern contains developed silver.   An optical filter for a flat panel display, wherein the visible light absorption filter having a minimum transmittance of 570 to 610 nm according to any one of claims 1 to 12 is used.   The optical filter for a flat panel display according to claim 13, which is used for a plasma display.   It has the visible light absorption filter which has the minimum value of the transmittance | permeability in 570-610nm in any one of Claims 1-12, or the optical filter for flat panel display panels in any one of Claims 13-14. Plasma display panel.