JP2010098073A - Electromagnetic shield member and plasma display panel equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic shield member which is improved so as to dispense with a near infrared ray absorption film and a film for color correction and prevent photodegradation. <P>SOLUTION: An electromagnetic wave shield mesh layer 9, which is formed in the shape of a grid, is formed in one surface of a base layer 8. An adhesive layer 11, which is used for adhesion to a front side of a display part of plasma display panel, is formed on an electromagnetic wave shield mesh layer 9. The adhesive layer 11 contains near-infrared cut colorant, neon cut colorant, and ultraviolet absorber. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention generally relates to an electromagnetic shielding material, and more specifically, has a near-infrared absorbing function, can perform color correction with high accuracy, and can further suppress deterioration. The present invention relates to an improved electromagnetic shielding material. The present invention relates to a plasma display panel provided with such an electromagnetic shielding material.

  FIG. 4 is an exploded perspective view of a conventional plasma display panel provided with various functional films. On the front side of the display unit 2 of the plasma display panel 1, an electromagnetic shielding (EMI) film 3, a near infrared absorption (NIR) film 4, a tint correction film 5, and an antireflection (AR) film 6 are provided. Are provided in order. The near-infrared absorbing film 4 is provided to block the near-infrared rays radiated from the plasma display panel 1, and prevents a malfunction of a remote controller that works with the near-infrared rays. The color correction film 5 is provided in order to adjust the balance between hue and light and darkness, for example, by imparting bluishness. These functional films are attached with an adhesive or an adhesive at the plasma display panel manufacturing site.

  However, at the display panel assembly site, these films 3, 4, 5, and 6 (collectively referred to as functional films) are prepared and affixed to increase the number of parts and perform operations such as alignment. It was complicated.

  Therefore, the applicant does not use a near-infrared absorbing film and a color correction film as shown in FIG. 5 and includes a near-infrared (NIR) cut dye and a neon cut dye (color correction dye). An electromagnetic shielding material using an absorbent adhesive composition has been proposed (see Patent Document 1).

  5A is a plan view of the electromagnetic shielding material according to Patent Document 1, and FIG. 5B is a cross-sectional view taken along the line BB in FIG. 5A.

  With reference to these drawings, the electromagnetic shielding material 7 includes a transparent resin base material (PET) 8. An electromagnetic shielding mesh layer 9 is provided on one surface of the transparent resin substrate 8 to block electromagnetic waves with an ink receiving layer (not shown) interposed therebetween. An antireflection layer 10 is provided on the other surface of the transparent resin substrate 8. An adhesive layer 11 made of a near-infrared absorbing adhesive composition containing a near-infrared cut dye and a neon cut dye so as to cover the electromagnetic shielding mesh layer 9 is on one surface side of the transparent resin substrate 8. Is provided.

The electromagnetic shielding mesh layer 9 is formed in a lattice shape by screen printing using, for example, silver paste made of conductive powder and a binder. The pressure-sensitive adhesive layer 11 side is attached to the front side of the display portion of the plasma display panel to complete the panel.
Japanese Patent Application No. 2008-102860

  According to Patent Document 1, since the near-infrared absorbing film and the color correction film are unnecessary, there are advantages that the number of parts is reduced and the assembling work is simplified.

  However, the near-infrared cut dye and neon cut dye contained in the pressure-sensitive adhesive layer have a problem of causing photodegradation when light is continuously irradiated for a long time.

  The present invention has been made to solve the above-described problems, and provides an electromagnetic shielding material improved so as not to use a near-infrared absorbing film and a color correction film and to prevent light deterioration. It is in.

  The present invention relates to an electromagnetic shielding material attached to the front surface of a plasma display, and includes a base material layer, an electromagnetic shielding mesh layer provided on one surface of the base material layer, and formed in a lattice shape. Is provided. A pressure-sensitive adhesive layer is provided on one surface side or the other surface side of the base material layer. A near-infrared cut dye and a neon cut dye are added to the pressure-sensitive adhesive layer, and an ultraviolet absorber is further included.

  According to the present invention, in addition to including the near-infrared cut dye and the neon cut dye in the pressure-sensitive adhesive layer, an ultraviolet absorber is also included. Photodegradation can be suppressed.

  Now, when a near-infrared cut dye and a neon cut dye are dissolved in the pressure-sensitive adhesive layer, the amount of the solid solution is close to the limit, and the amount of the ultraviolet absorber that can be dissolved in the pressure-sensitive adhesive layer is limited. come. On the other hand, when the amount of the UV absorber is further increased, the haze is increased and precipitation of the dissolved dye is observed, and the near-infrared cut effect is lowered when left in a high temperature and humid heat environment, and Deterioration is seen. However, as a result of intensive studies, the inventors have found that the addition amount of the ultraviolet absorber can be reduced by combining the ultraviolet absorber and the electromagnetic shielding mesh layer, and have reached the present invention. Although the details of the reason why such a phenomenon occurs are not yet clear, a combination of the ultraviolet absorber and the electromagnetic shielding mesh layer causes a synergistic effect due to some interaction between them, and a small amount of the ultraviolet absorber. Even so, it is considered that it exhibited a sufficient UV resistance effect. As a result, the amount of UV absorber added can be reduced, so that the haze does not increase, the precipitation of the dissolved dye does not occur, and the dye deteriorates when left in a high temperature and humid environment. Absent.

  The adhesive resin is preferably an acrylic adhesive containing an acrylic polymer. When an alkyl alkyl ester having 4 to 8 carbon atoms in the alkyl group is used, the adhesive strength and flexibility of the resulting pressure-sensitive adhesive are improved. In particular, butyl acrylate and 2-ethylhexyl acrylate are preferred. When a carboxyl group-containing monomer and a hydroxyl group-containing monomer are copolymerized, crosslinking can be performed using an isocyanate-based crosslinking agent or the like.

  1 to 10 parts by weight of a diimonium dye having a solubility in 1 g of ethyl acetate at 25 ° C. of not less than 0.6 mg, 0.01 to 1 part by weight of a neon cut dye, and benzophenone based on 100 parts by weight of the acrylic pressure-sensitive adhesive It is preferable to contain 1-10 weight part of ultraviolet absorbers.

  0.001 to 10% by weight of at least one curing agent selected from the group consisting of an isocyanate curing agent, an epoxy curing agent and a metal chelate curing agent with respect to 100 parts by weight of the acrylic adhesive. It is preferable to include a part.

  It is preferable to contain 1 to 10 parts by weight of the diimonium dye and the phthalocyanine dye together with 100 parts by weight of the acrylic pressure-sensitive adhesive.

  The neon cut dye is preferably a cyanine dye, squarylium dye, porphyrin dye or indole compound dye.

  The benzophenone-based UV absorber preferably contains tetrahydroxybenzophenone.

  It is preferable that an antireflection layer is provided on the other surface side of the base material layer.

  The electromagnetic shielding mesh layer is preferably formed in a grid pattern by screen printing using a silver paste.

  The electromagnetic shielding mesh layer may be formed in a lattice shape by etching a copper foil.

  The pressure-sensitive adhesive layer is preferably provided so as to come into contact with and cover the electromagnetic shielding mesh layer.

  According to the electromagnetic shielding material according to the present invention, it is not necessary to separately prepare a near-infrared absorbing film and a color correction film, and the number of parts is reduced. In addition to containing near-infrared cut dyes and neon cut dyes in the adhesive layer, UV absorbers are also included, thus suppressing photodegradation of near-infrared cut dyes and neon cut dyes. can do. Then, due to the synergistic effect of the ultraviolet absorber and the electromagnetic shielding mesh layer, the addition amount of the ultraviolet absorber can be reduced, haze does not increase, and precipitation does not occur. Moreover, deterioration of the near-infrared cut pigment by the ultraviolet absorber can also be suppressed. Note that when a large amount of the ultraviolet absorber is added, the near-infrared cut pigment deteriorates, and the color change and the transmittance in the near-infrared region increase, but according to the present invention, the amount of the ultraviolet absorber can be reduced. This is prevented.

A near-infrared cut dye and a neon cut dye are applied to the adhesive layer for the purpose of obtaining an electromagnetic shielding material that does not require a near-infrared absorbing film and a color correction film and that does not cause light deterioration. In addition, it was realized by including a UV absorber. Hereinafter, the present invention will be described with reference to the drawings.
(Embodiment 1)

  FIG. 1 is a cross-sectional view of an electromagnetic shielding material 7 according to the present invention.

  An electromagnetic wave shield mesh layer 9 formed in a lattice shape is provided on one surface of the base material layer (PET film) 8. The electromagnetic shielding mesh layer 9 is formed on the ink receiving layer (not shown) on the transparent resin substrate 8 by screen printing with a conductive paste ink. The conductive paste ink is composed of conductive powder and a binder. For example, it is formed in a grid by screen printing using a silver paste. When the conductive paste ink is baked, the electromagnetic shielding mesh layer 9 is formed. On the electromagnetic shielding mesh layer 9, an adhesive layer 11 for adhering to the front surface of the plasma display panel is provided. The pressure-sensitive adhesive layer 11 includes a near-infrared cut dye, a neon cut dye, and an ultraviolet absorber.

  The near infrared cut dye used in the present invention may be a dye having a maximum absorption wavelength at 800 nm to 1100 nm, and examples thereof include diimonium dyes and phthalocyanine dyes. You may use these both individually or in combination of 2 or more types. Among these, a diimonium dye is preferable, and a diimonium dye is essential in the present invention. These dyes should have high solubility in a solvent or the like. Specifically, the solubility in 1 g of ethyl acetate at 25 ° C. under normal pressure (about 0.1 MPa) is 0.6 mg or more, preferably 0.8 to 300 mg, more preferably 1 to 200 mg. Here, the reason why ethyl acetate was used as a reference solvent is that the solubility parameter value (SP value) of ethyl acetate approximates that of acrylic adhesive (A).

  In the present invention, the content of the diimonium dye is 1 to 10 parts by weight, preferably 1.2 to 100 parts by weight (solid content) of the acrylic pressure-sensitive adhesive having a weight average molecular weight of 1,200,000 to 2,000,000. 8 parts by weight, more preferably 1.5 to 6 parts by weight.

  By using it in the above-mentioned amount, the diimonium dye can be stabilized by the acrylic pressure-sensitive adhesive, and excellent haze characteristics, transmittance reduction under a moist heat environment, and haze increase can be suppressed.

  Further, in addition to the diimonium dye, a phthalocyanine dye may be used in combination. In that case, the total amount of the diimonium dye and the phthalocyanine dye is 1 to 10 parts by weight, preferably 1.2 to 8 parts by weight, more preferably 1 to 100 parts by weight of the acrylic pressure-sensitive adhesive. .5 to 6 parts by weight. The content ratio (mass ratio) of the diimonium dye and the phthalocyanine dye is, for example, 100: 1 to 1: 1, preferably 20: 1 to 5: 4.

  The predetermined amount of the above-mentioned predetermined dye is used when the amount of the dye is small, the dye is often precipitated or deteriorated in the pressure-sensitive adhesive, and when the amount is large, the transmittance in the visible region is high. It is because it falls.

As the diimonium dye, the general formula (I):
The compound which has the partial structure represented by these is mentioned. Specifically, the general formula (Ia):
(Wherein R1 to R8 independently represent a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. An aryl group, a hydroxy group, an aryloxy group which may have a substituent, an alkoxy group which may have a substituent, or an acyloxy group, and X- represents an anion. .).

  Examples of the alkyl group of the alkyl group which may have a substituent include a linear, branched, or cyclic alkyl group having 1 to 20, preferably 4 to 8, more preferably 4 to 6 carbon atoms. It is done. When the carbon number is 4 or more, the solubility in an organic solvent is good, and when the carbon number is 8 or less, the heat resistance is good. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a t-butyl group, and a 3-methyl-butyl group. N-pentyl group, iso-pentyl group, neo-pentyl group, cyclopentyl group, 1,2-dimethylpropyl group, n-hexyl group, cyclohexyl group, 1,3-dimethylbutyl group, 1-iso-propylpropyl group 1,2-dimethylbutyl group, n-heptyl group, 1,4-dimethylpentyl group, 2-methyl-1-iso-propylpropyl group, 1-ethyl-3-methylbutyl group, n-octyl group, 2- Ethylhexyl group, 3-methyl 1-iso-propylbutyl group, 2-methyl-1-iso-propyl group, 1-t-butyl-2-methylpropyl group, n Nonyl, 3,5,5-trimethyl hexyl group.

  The alkyl group may have a substituent such as a hydroxyl group, a halogen atom, an amino group, an alkylamino group, an alkoxycarbonyl group, an acyl group, a sulfo group, or a carboxyl group.

  Examples of the alkenyl group of the alkenyl group that may have a substituent include linear, branched, or cyclic alkenyl groups having 2 to 20 carbon atoms, preferably 4 to 8 carbon atoms, and more preferably 4 to 6 carbon atoms. It is done. Examples of the alkenyl group include a vinyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, and an octenyl group.

  The alkenyl group may have a substituent such as a hydroxyl group, a halogen atom, an amino group, an alkylamino group, an alkoxycarbonyl group, an acyl group, a sulfo group, or a carboxyl group.

  Examples of the aralkyl group of the aralkyl group which may have a substituent include a benzyl group, a p-chlorobenzyl group, a p-methylbenzyl group, a 2-phenylethyl group, a 2-phenylpropyl group, and a 3-phenylpropyl group. , A naphthylmethyl group, or a 2-naphthylethyl group.

  The aralkyl group may have a substituent such as a hydroxyl group, a halogen atom, an amino group, an alkylamino group, an alkoxycarbonyl group, an acyl group, a sulfo group, or a carboxyl group on the aromatic ring.

  Examples of the aryl group of the aryl group which may have a substituent include a monocyclic or bicyclic aryl group, and examples thereof include a phenyl group, a naphthyl group, and a biphenyl group.

  The aryl group may have a substituent such as a hydroxyl group, a halogen atom, an amino group, an alkylamino group, an alkoxycarbonyl group, an acyl group, a sulfo group, or a carboxyl group.

  Examples of the aryloxy group of the aryloxy group which may have a substituent include monocyclic or bicyclic aryloxy groups, such as a phenyloxy group, a naphthyloxy group, and a biphenyloxy group. .

  The aryl group may have a substituent such as a hydroxyl group, a halogen atom, an amino group, an alkylamino group, an alkoxycarbonyl group, an acyl group, a sulfo group, or a carboxyl group.

  The alkoxy group of the alkoxy group which may have a substituent includes, for example, a linear, branched, or cyclic alkoxy group having 1 to 20 carbon atoms, preferably 4 to 8 carbon atoms, more preferably 4 to 6 carbon atoms. It is done. When the carbon number is 4 or more, the solubility in an organic solvent is good, and when the carbon number is 8 or less, the heat resistance is good. Examples of the alkyl group include methoxy group, ethoxy group, n-propyloxy group, iso-propyloxy group, n-butyloxy group, iso-butyloxy group, sec-butyloxy group, t-butyloxy group, 3-methyl- Butyloxy group, n-pentyloxy group, iso-pentyloxy group, neo-pentyloxy group, cyclopentyloxy group, 1,2-dimethylpropyloxy group, n-hexyloxy group, cyclohexyloxy group, 1,3-dimethylbutyl Oxy group, 1-iso-propylpropyloxy group, 1,2-dimethylbutyloxy group, n-heptyloxy group, 1,4-dimethylpentyloxy group, 2-methyl-1-iso-propylpropyloxy group, 1 -Ethyl-3-methylbutyloxy group, n-octyloxy group, 2 Ethylhexyloxy group, 3-methyl 1-iso-propylbutyloxy group, 2-methyl-1-iso-propyloxy group, 1-t-butyl-2-methylpropyloxy group, n-nonyloxy group, 3, 5, 5-trimethylhexyloxy group etc. are mentioned.

  The alkoxy group may have a substituent such as a hydroxyl group, a halogen atom, an amino group, an alkylamino group, an alkoxycarbonyl group, an acyl group, a sulfo group, or a carboxyl group.

  Examples of the acyloxy group include C2-10 alkanoyloxy groups such as acetyloxy group, propionyloxy group and butyryloxy group; and allyloyloxy groups such as benzoyloxy group and naphthoyloxy group.

  Examples of the anion represented by X- include chlorine ion, bromine ion, iodine ion, perchlorate ion, periodate ion, nitrate ion, benzenesulfonate ion, P-toluenesulfonate ion, methylsulfate ion, Ethyl sulfate ion, propyl sulfate ion, tetrafluoroborate ion, tetraphenylborate ion, hexafluorate ion, benzenesulfinate ion, acetate ion, trifluoroacetate ion, propionate acetate ion, benzoate ion, oxalate ion Succinate ion, malonate ion, oleate ion, stearate ion, citrate ion, monohydrogen diphosphate ion, dihydrogen monophosphate ion, pentachlorostannate ion, chlorosulfonate ion, fluorosulfonate ion , Trifluoromethanesulfo Acid ion, hexafluoroarsenate ion, hexafluoroantimonate ion, molybdate ion, tungstate ion, titanate ion, zirconate ion, bis (trifluoromethanesulfonyl) imide ion, naphthyl sulfonate ion and the like.

  Among these anions, perchlorate ion, iodine ion, tetrafluoroborate ion, hexafluorophosphate ion, hexafluoroantimonate ion, trifluoromethanesulfonate ion, bis (trifluoromethanesulfonyl) imido ion, etc. Bis (trifluoromethanesulfonyl) imido ion is preferred because it is most excellent in solubility and thermal stability.

A preferred anion-substituent combination is that the anion is a bis (trifluoromethanesulfonyl) imidate ion, and the substituent is an alkyl group, more preferably an n-butyl group.
The diimonium dye preferably has a molar extinction coefficient ε around 1000 nm of about 0.8 × 10 4 to 1.0 × 10 6. In addition, it is preferable to use a diimonium dye having a purity of 98% or higher, or a diimonium dye having a melting point of 160 ° C. or higher.

As the phthalocyanine-based dye, the general formula (II):
And a compound having a maximum absorption wavelength at 800 to 1000 nm. Examples thereof include fluorine-containing phthalocyanine dyes described in JP-A No. 2001-133623, phthalocyanine dyes described in Japanese Patent No. 3949603, and the like. Specifically, Nippon Shokubai Co., Ltd., Y-EXKARA-IR-10, Y-EXKARA-IR-10A, Y-EXKARA-IR-14, Y-EXKARA-IR-12, Y-EXKARA-IR-910, Y-EXCALA-IR-906, Y-EXKARA-IR-HA-1, and the like can be used.

  The central metal M of the phthalocyanine dye is not particularly limited, and is metal-free (hydrogen), metal such as iron, copper, zinc, vanadium, titanium, indium and tin, chloride, bromide, iodine of the metal. Metal halides such as fluoride, metal oxides such as vanadium oxide, titanyl oxide and copper oxide, organic acid metals such as acetate, complex compounds such as acetylacetonate, and metal carbonyls such as carbonyl iron, etc. . Of these, metals, metal oxides and metal halides are preferred. More preferred is vanadium oxide.

  As the phthalocyanine dye, when Pc is a phthalocyanine nucleus and Ph is a phenyl group, phthalocyanine [CuPc (2,5-C12PhO) 8 {2,6- (CH3) 2PhO} 4 (PhCH2NH) 4] (λmax 807 nm) ), Pc (2,5-Cl2PhO) 8 (2,6-Br2-4-CH3PhO) 4 {Ph (CH3) CHNH} 3F (λmax 835 nm), VOPc (2,5-Cl2PhO) 8 (2,6-Br2) -4-CH3PhO) 4 {PhCH2NH} 3F (λmax 840 nm), VOPc (2,5-Cl2PhO) 8 (2,6- (CH3) 2PhO) 4 {Ph (CH3) CHNH} 3F (λmax834 nm), VOPc (2, 6-Cl2PhO) 8 (2,6- (CH3) 2PhO) 4 {Ph (CH3) CHNH} F (λmax 835 nm), VOPc (4-CNPhO) 8 (2,6-Br2-4-CH3PhO) 4 {Ph (CH3) CHNH} 3F (λmax 836 nm), VOPc (4-CNPhO) 8 (2,6- (CH3) ) 2PhO) 4 {Ph (CH3) CHNH} 3F (λmax 834 nm). Further, those having the maximum absorption wavelength at 850 to 1000 nm include [VOPc (2,5-Cl 2 PhO) 8 {2,6- (CH 3) 2 PhO} 4 (PhCH 2 NH) 4] (λmax 870 nm), [VOPc (PhS) 8 {2,6- (CH3) 2PhO} 4 (PhCH2NH) 4] (λmax 912 nm), VOPc (2,5-Cl2PhO) 4 (2,6- (CH3) 2PhO) 4 {(C2H5) 2NCH2CH2NH} 4 (λmax 893 nm ) Etc.

  The neon cut dye used in the present invention will be described. The plasma display emits so-called neon orange light centered around 600 nm, and has a drawback that a bright red color cannot be obtained because the orange color is mixed with the red color. By including a neon cut pigment, the above problem can be solved.

  A neon cut dye is a dye having maximum absorption in a wavelength range of 550 nm to 620 nm, specifically, cyanine-based, squarylium-based, indolic compound-based, azomethine-based, xanthene-based, oxonol-based, Examples thereof include azo, phthalocyanine, quinone, azurenium, pyrylium, croconium, dithiol metal complex, pyromethene, and porphyrin. These dyes can be used alone or in admixture of two or more. In the present invention, cyanine dyes, squarylium dyes, porphyrin (tetraazoporphyrin compounds), indole compound dyes are used. It is preferable to use it.

  Specific examples include Yamada Chemical Co., Ltd., TAP-2 (tetraazoporphyrin compound), ADEKA Corporation, Adeka Cruz TY-100 (cyanine series), Adeka Cruz TY-102 (cyanine series), Adeka Accruz. TY-171 (cyanine type) can be mentioned, and Yamada Chemical Co., Ltd. and TAP-2 (tetraazoporphyrin compound) are preferable. Also, eosin Y (600 nm), Phloxine B (540 nm) [Red No. 104], Rose Bengal (550 nm) [Red No. 105] dye may be used.

  The neon-cut dye content is such that the obtained wavelength selective absorption filter has a sharp absorption in the wavelength region of 550 nm to 620 nm and the transmittance at the maximum absorption wavelength is 40% or less. It is preferable to adjust to. It is 0.001 weight part or more with respect to 100 weight part of said acrylic adhesives (A), Preferably it is 0.005-1 weight part, More preferably, it is 0.01-1 weight part.

  The pressure-sensitive adhesive layer of the present invention may further contain a curing agent. Examples of the curing agent include isocyanate curing agents, epoxy curing agents, metal chelate curing agents, and the like. Of these, isocyanate curing agents are preferred. Content of a hardening | curing agent is 0.001-10 weight part with respect to 100 weight part of said acrylic adhesives, Preferably it is 0.01-5 weight part. In particular, when an isocyanate curing agent and a metal chelate curing agent are used in combination, the content ratio (mass ratio) between the isocyanate curing agent and the metal chelate curing agent is 100: 1 to 1: 1. About 50, preferably about 50: 1 to 2: 1.

  Examples of the isocyanate curing agent include tolylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, Tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, tri Polyisocyanate compounds having two or more isocyanate groups in the molecule such as phenylmethane triisocyanate, polymethylene polyphenyl isocyanate; and the like such as trimethylolpropane, pentaerythritol, etc. Compounds obtained by addition reaction with a valent alcohol; these polyisocyanates Compound bullet type compounds and isocyanurate compounds; these polyisocyanate compounds and addition reactions with known polyester polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, etc. Examples thereof include compounds having two or more isocyanate groups in the urethane prepolymer type molecule.

  Among them, tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, a compound obtained by addition reaction of tetramethylene diisocyanate and trimethylolpropane has good reactivity. Therefore, it is preferably used.

  Such an isocyanate curing agent is used in an amount of 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the acrylic pressure-sensitive adhesive.

  When the acrylic pressure-sensitive adhesive has a carboxyl group, an epoxy-based compound can also be used as a curing agent. Examples of the epoxy compound include bisphenol A epichlorohydrin type epoxy resin, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1, 6-hexanediol glycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diamine glycidyl amine, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, 1,3-bis Examples thereof include compounds having two or more epoxy groups in the molecule such as (N, N′-diamine glycidylaminomethyl) cyclohexane.

  Among these, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine is preferably used because of its excellent reactivity with a carboxyl group.

  Such an epoxy curing agent is used in an amount of 0.001 to 2 parts by weight, preferably 0.01 to 0.5 parts by weight, based on 100 parts by weight (solid content) of the acrylic adhesive.

  As the metal chelate curing agent, for example, acetylacetone, ethyl acetoacetate and the like are coordinated to a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium. Compounds and the like.

  Among them, a compound in which acetylacetone and ethyl acetoacetate are arranged on aluminum is preferably used because it has an action of suppressing deterioration of the diimonium dye.

  Such a metal chelate curing agent is used in an amount of 0.01 to 1 part by weight, preferably 0.05 to 0.5 part by weight, based on 100 parts by weight of the acrylic pressure-sensitive adhesive (solid content).

  In order to control the reaction between the pressure-sensitive adhesive and the curing agent, an organometallic system, an amine system, or a mixture thereof is used as a catalyst. Representative examples of catalysts include dibutyltin dilaurate and stannous octylate for organometallics, and tertiary amines and amine salts such as triethylamine and triethylenediamine for amines, but are not limited thereto. It is not something.

  In the pressure-sensitive adhesive layer, a color tone correction dye having a maximum absorption wavelength in the range of 300 to 800 nm, a leveling agent, an antistatic agent, a thermal stabilizer, an antioxidant, a dispersion, as long as the effects of the present invention are not impaired. An agent, a flame retardant, a lubricant, and a plasticizer may be contained.

  The above-mentioned acrylic pressure-sensitive adhesive, a near-infrared cut dye containing a diimonium compound, a neon cut dye, an ultraviolet absorber, and if necessary a curing agent are mixed and dispersed by a known method to form a near-infrared absorbing adhesive composition. obtain. The mixing and dispersing method is not particularly limited, but it is preferable to use a disperser such as a dissolver, a high speed mixer, a homomixer, a sand mill, an attritor, a homogenizer, or a ball mill.

  The electromagnetic wave shielding material of the present invention is obtained by, for example, using a liquid obtained by dissolving or dispersing a near-infrared absorbing pressure-sensitive adhesive composition in an organic solvent (hereinafter referred to as a coating liquid) on a releasable substrate or support film. It can be formed by coating and drying.

  Examples of the organic solvent include aromatics such as toluene and xylene, amides such as N-methyl-2-pyrrolidone, dimethylformamide, and dimethylacetamide, ketones such as methyl ethyl ketone, methyl isobutyl ketone, and acetone, methanol, and ethanol. And alcohols such as alcohol and i-propyl alcohol, hydrocarbons such as hexane, tetrahydrofuran and the like.

  Examples of the method for applying the above-mentioned near-infrared absorbing pressure-sensitive adhesive composition on a substrate include a doctor blade, a bar coater, a gravure coater, a comma coater, and a river scale. -Well-known coating methods, such as a turter and a spray method, are mentioned.

  Examples of the substrate include a film-like or sheet-like plastic film and a glass plate. A plastic film is preferable in terms of transparency, cost, and ease of handling. Specific examples include polyester, acrylic, triacetyl cellulose, polyethylene, polypropylene, polyolefin, and polycycloolefin, and polyester films are preferred.

  The coating liquid is applied onto a substrate having a release property. Although it does not specifically limit about the thickness of an adhesion layer, 5 micrometers-50 micrometers, Preferably they are 10 micrometers-40 micrometers, More preferably, 20 micrometers-30 micrometers are good. Furthermore, the base material which gave mold release property is bonded together in the state which a bubble does not generate | occur | produce.

  Thus, after providing the near-infrared absorbing layer in the present invention on a peelable substrate or support film, it is possible to further attach a release film on the near-infrared absorbing layer. This is preferable. As the release film, the same as the above-described peelable substrate can be used.

  The ultraviolet absorber is a benzophenone-based ultraviolet absorber. Those having good compatibility with the pressure-sensitive adhesive are preferable, and specific examples include SEESORB100, SEESORB106, SEESORB107 manufactured by Sipro Kasei Co., Ltd. and the like. The synergistic action of the ultraviolet absorber and the electromagnetic shielding mesh layer suppresses photodegradation of the dye. An antireflection layer 10 is provided on the other surface of the base material layer (PET film) 8. When a protective film (not shown) is formed on the pressure-sensitive adhesive layer 11, a product called an electromagnetic shielding material 7 is completed.

  The electromagnetic shielding mesh layer is not particularly limited as long as it shields electromagnetic waves emitted from the plasma display, and the manufacturing method thereof is not particularly limited. For example, when the electromagnetic shielding material is formed of a transparent conductive film, a film obtained by vapor-depositing a thin film of metal, metal oxide, metal salt or the like on a transparent resin substrate (plastic film) is used. The lower the surface resistance of the conductive film, the higher the electromagnetic wave absorption ability, but conversely the visible light transmittance decreases as the vapor deposition layer becomes thicker. In addition, a conductive paint is printed in a mesh shape by screen printing or the like, or a conductive metal is laminated on a transparent resin base material (plastic film), and the conductive metal is formed in a mesh shape by etching or the like. Things can also be used.

  Furthermore, you may form an antireflection layer in the opposite surface to the surface in which the conductive thin film or conductive mesh-like material of a transparent resin base material is formed.

  The antireflection layer prevents surface reflection, increases visible light transmittance, and at the same time prevents glare, and a known layer can be used. As the formation method, any processing method can be selected, and there is no particular limitation. A method for reducing luminous reflectance by irregularly reflecting external light, for example, an antireflection film that causes irregular reflection of light by coating with coating fine particles of silicon dioxide, acrylic, melamine, etc. on one side of a plastic film A method of forming, or a method of forming a cured film on one side of a plastic film such as PET, and forming an antireflection layer on the magnesium fluoride layer by vapor deposition, or a refractive index of a thin film on one side or both sides of the plastic film A method is generally used in which a layer is formed and the reflectance is reduced by light interference between the surface reflected light of the thin film and the refracted reflected light at the interface.

  The electromagnetic shielding material of the present invention is a transparent resin substrate comprising a transparent porous layer containing as a main component at least one selected from the group consisting of oxide ceramics, non-oxide ceramics and metals. A conductive paste containing particulate silver oxide, tertiary fatty acid silver and a solvent is screen-printed on the geometric pattern on the porous layer surface, and the substrate after printing is further heated (baked). It is manufactured by forming a conductive portion of a geometric pattern on the surface of the transparent porous layer.

  FIG. 2 is a perspective view when the electromagnetic shielding material 7 is attached to the plasma display panel. The adhesive layer 11 is attached to the display unit 2 of the plasma display panel 1 and the electromagnetic shielding material 7 is attached. The harmful electromagnetic wave emitted from the plasma display panel 1 is captured by the electromagnetic shielding mesh layer 9 and escapes to the ground through a connection pad, a conductive gasket, and an earth (not shown).

  Since the near-infrared cut dye and the neon cut dye are included in the pressure-sensitive adhesive layer 11, it is not necessary to separately prepare a near-infrared absorbing film and a color correction film, and the number of parts is reduced. As a feature of this example, the adhesive layer 11 includes a near-infrared cut dye and a neon cut dye, and also includes an ultraviolet absorber, so that the near infrared cut dye and the neon cut dye are included. Can be suppressed. Further, it was found that the amount of the ultraviolet absorber added can be reduced by combining the ultraviolet absorber and the electromagnetic shielding mesh layer. By reducing the addition amount of the ultraviolet absorber, haze does not increase and precipitation does not occur.

  (Examples and comparative examples)

Acrylic adhesive PX4-IR-PT-076 (Nippon Catalyst solids concentration 37.5%)
100 parts by weight of diimmonium salt of bis (trifluoromethanesulfonyl) imidic acid (1085F manufactured by Nippon Carlit, 30 mg solubility in 1 g of ethyl acetate at 25 ° C.) 0.85 parts by weight, tetraazoporphyrin compound (Yamada Chemical) 0.075 part by weight of TAP-2) manufactured by industry, 0.19 part by weight of isocyanate-based curing agent (L-55E manufactured by Nippon Polyurethane Industry), 0.019 of curing accelerator (dibutyltin dilaurate manufactured by Tokyo Chemical Industry) An adhesive composition was prepared by adding parts by weight. Methyl ethyl ketone (MEK) was added thereto, and the mixture was put into a homogenizer and stirred at 10,000 rpm for 10 minutes to obtain a pressure-sensitive adhesive composition A having a solid content concentration of 10%.

  Add 0%, 0.5%, 1%, 2%, 3%, 5%, 10%, 15% UV absorber (SEPRORB106 manufactured by Sipro Kasei) to the solid content concentration of the adhesive composition A And 8 types of adhesive compositions B were obtained.

  The prepared pressure-sensitive adhesive composition B was applied onto a peelable substrate S-71 (manufactured by Teijin Limited) using a bar coater so that the thickness after drying was 20 μm, and dried at 90 ° C. Machine dried for 2 minutes. After drying, a peelable substrate A-31 (manufactured by Teijin Ltd.) is bonded to the pressure-sensitive adhesive layer side and aged at 23 ° C. for 7 days to obtain a near infrared absorbing pressure-sensitive adhesive sheet (transfer sheet). It was.

  The electromagnetic shielding material and the near-infrared absorbing adhesive sheet were bonded together by a laminating machine and further bonded to glass. Specifically, the peelable substrate A-31 (manufactured by Teijin Ltd.) of the near-infrared absorbing adhesive sheet is peeled, and the surface on which the electromagnetic shielding mesh of the electromagnetic shielding material is formed. The peelable substrate S-71 (manufactured by Teijin Ltd.) of the near-infrared absorbing adhesive sheet was peeled off and pasted with alkali glass (thickness 28 mm).

In Table 1, as an example, the addition amount (%) (% by weight) of the ultraviolet absorber with respect to the solid content of the adhesive in the case of mesh layer / near-infrared cut dye + neon cut dye + adhesive / glass, and ultraviolet rays The relationship with the color difference ΔEab before and after irradiation is shown. Addition amount (%) (% by weight) of ultraviolet absorber to solid content of adhesive in case of PET / Near cut dye + Neon cut dye + Adhesive / Glass (without mesh) as comparative example, and UV irradiation The relationship with the color difference ΔEab before and after is also shown. Presence / absence of pigment precipitation at the initial stage, color difference ΔEa before and after durability evaluation, and transmittances at 850 nm and 950 nm are also shown.

Here, the addition amount of the ultraviolet absorber is based on the solid content concentration of the pressure-sensitive adhesive. Here, the ultraviolet irradiation conditions were set to 63 ° C. 43% × 24 h and irradiation intensity setting 550 W / m ² using an ultraviolet auto fade meter U48AU (manufactured by Suga Test Instruments Co., Ltd.). This condition was the same in the comparative example.

  Those having ΔEab of 1.5 or less are acceptable. As is clear from Tables 1 and 2, when there is a mesh, the acceptance criterion is reached when the amount of the UV absorber added is 1%, but when there is no mesh, the acceptance criterion is that up to 5% is not added. Did not reach. Thereby, it turned out that the addition amount of a ultraviolet absorber can be decreased by combining the said ultraviolet absorber and electromagnetic shielding mesh layer. When ΔEab was 1.5 or less, the change in spectral transmittance in the near infrared region was 5% or less.

  “Transmittance at 850 nm and 950 nm” was measured using a spectrophotometer (JASCO V670) to measure the transmittance at 300 nm to 1600 nm and measure the transmittance at 850 nm and 950 nm. The transmittance was 10% or less under each environment as the acceptance standard.

Increasing the amount of UV absorber added showed an increase in transmittance in the environmental test (60 ° C., 90%, 1000 h). It is presumed that the addition of a large amount of ultraviolet absorber absorbed moisture and caused deterioration to the pigment.
(Embodiment 2)

  FIG. 3 is a conceptual diagram of a plasma display panel to which an electromagnetic shielding material according to Embodiment 2 is attached. Referring to FIG. 3, a filter 13 is disposed on the front side of the display unit of plasma display panel 1.

  The filter 13 includes a glass substrate layer 14, an antireflection film 15, and a mesh film 16. The antireflection film 15 is formed by coating an antireflection film 15a on a PET film. The mesh film 16 is formed by forming a conductive mesh 16a on a PET film. The glass base material layer 14, the antireflection film 15 and the mesh film 16 are bonded together with pressure-sensitive adhesive layers 18a and 18b, respectively. The conductive mesh 16a is formed in a grid by screen printing using, for example, silver paste. A connection pad 16b integrally formed with the grid connected to the conductive gasket 19 is also formed simultaneously with the conductive mesh 16a by screen printing.

  The filter 13 is pressed against the front surface of the plasma display panel 1 so that the conductive gasket 19 and the connection pad 16b are in contact with each other, and is fixed to the adhesive layer 18a. The feature of this example is that, in addition to the near-infrared cut pigment and neon cut pigment included in the pressure-sensitive adhesive layer 18c, an ultraviolet absorber is also included. Thereby, the photodegradation of a near-infrared cut pigment | dye and a neon cut pigment | dye can be suppressed. And since the synergistic action of the ultraviolet absorber and the conductive mesh 16a occurs, the amount of the ultraviolet absorber added can be reduced, the haze does not increase, and no precipitation occurs. The addition amount (%) of the ultraviolet absorber was the same as in the first embodiment.

  The harmful electromagnetic wave emitted from the plasma display panel 1 is captured by the conductive mesh 16a, and escapes to the ground through the connection pad 16b, the conductive gasket 19, and the ground.

  In the above embodiment, the case where the electromagnetic shielding mesh layer is formed by screen printing using silver paste is exemplified, but the present invention is not limited to this, and copper foil is used. The present invention can also be applied to the case where it is formed by etching in a lattice shape.

  The UV absorber was not added to the pressure-sensitive adhesive layer 18c, but was added to the pressure-sensitive adhesive layers 18a and 18b that were not in contact with the electromagnetic shielding mesh 16a. As a result, in the pressure-sensitive adhesive layers 18a and 18b that do not come into contact with the electromagnetic shielding mesh 16a, the effect of reducing the addition amount of the ultraviolet absorber was weak.

Moreover, in the said embodiment, although the case where the adhesive layer was provided so that it might contact and coat | cover the electromagnetic shielding mesh layer was illustrated, it does not coat | cover a mesh layer, Even when the electromagnetic shielding mesh layer is provided on the side opposite to the side on which the electromagnetic shielding mesh layer is formed, there is a considerable effect.
It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the present invention, the additive amount of the ultraviolet absorber can be reduced by the synergistic effect of the ultraviolet absorber and the electromagnetic shielding mesh layer.

It is sectional drawing of the electromagnetic wave shielding material which concerns on Embodiment 1 of this invention. It is a perspective view at the time of attaching an electromagnetic shielding material to a plasma display panel. It is a conceptual diagram of the plasma display panel which attached the electromagnetic wave shielding material which concerns on Embodiment 2. FIG. It is a disassembled perspective view of the conventional plasma display panel provided with various functional films. (A) It is a top view of the electromagnetic shielding material which concerns on a prior art. (B) It is sectional drawing which follows the BB line in FIG. 5 (A).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plasma display panel 2 Display part 3 Electromagnetic shielding film 4 Near-infrared absorption film 5 Film for color correction 6 Antireflection film 7 Electromagnetic shielding material 8 Transparent resin base material 9 Electromagnetic shielding mesh layer 10 Antireflection Layer 11 Adhesive layer 13 Filter 14 Glass substrate layer 15 Antireflection film 15a Antireflection film 16 Mesh film 16a Conductive mesh 16b Connection pad 18a, b, c Adhesive layer 19 Conductive gasket

Claims (12)

An electromagnetic shielding material attached to the front surface of the plasma display,
A base material layer;
An electromagnetic shielding mesh layer formed in a lattice shape, provided on one surface side of the base material layer;
A pressure-sensitive adhesive layer provided on one surface side or the other surface side of the base material layer,
An electromagnetic shielding material characterized by adding a near-infrared cut dye and a neon cut dye to the pressure-sensitive adhesive layer and further containing an ultraviolet absorber.   The electromagnetic wave shielding material according to claim 1, wherein the adhesive resin includes an acrylic adhesive.   With respect to 100 parts by weight (solid content) of the acrylic pressure-sensitive adhesive, 1 to 10 parts by weight of a diimonium dye having a solubility in 1 g of ethyl acetate at 25 ° C. of 0.6 mg or more and 0.01 to 1 weight by weight of a neon cut dye. The electromagnetic shielding material according to claim 2, comprising 1 to 10 parts by weight of a benzophenone ultraviolet absorber.   To 100 parts by weight (solid content) of the acrylic adhesive, at least one curing agent selected from the group consisting of an isocyanate curing agent, an epoxy curing agent and a metal chelate curing agent is further added. The electromagnetic wave shielding material according to claim 3, comprising 001 to 10 parts by weight.   The electromagnetic shielding material according to claim 4, comprising 1 to 10 parts by weight of the diimonium dye and the phthalocyanine dye together with 100 parts by weight (solid content) of the acrylic pressure-sensitive adhesive.   The electromagnetic shielding material according to claim 4, wherein the neon cut dye is a cyanine dye, a squarylium dye, a porphyrin dye, or an indole compound dye.   The electromagnetic shielding material according to claim 4, wherein the benzophenone-based ultraviolet absorber contains tetrahydroxybenzophenone.   The electromagnetic shielding material according to claim 1, wherein an antireflection layer is provided on the other surface side of the base material layer.   2. The electromagnetic shielding material according to claim 1, wherein the electromagnetic shielding mesh layer is formed in a lattice shape by screen printing using a silver paste.   2. The electromagnetic shielding material according to claim 1, wherein the electromagnetic shielding mesh layer is formed in a lattice shape by etching a copper foil.   2. The electromagnetic shielding material according to claim 1, wherein the pressure-sensitive adhesive layer is provided so as to be in contact with and cover the electromagnetic shielding mesh layer.   A plasma display panel on which the electromagnetic shielding material according to claim 1 is mounted.