JP4848150B2 - Manufacturing method of electromagnetic shielding mesh, electromagnetic shielding mesh manufactured by the method, and display including the electromagnetic shielding mesh - Google Patents

Description

  The present invention relates to a method for producing an electromagnetic wave shielding mesh for shielding electromagnetic waves generated from the front surface of a display such as a CRT (cathode ray tube), plasma, liquid crystal, EL (electroluminescence), etc., an electromagnetic wave shielding mesh produced by the method, The present invention relates to a display in which an electromagnetic shielding mesh is bonded to the surface.

In recent years, as the use of various electrical equipment and electronic application equipment has increased, noise interference due to electromagnetic waves generated from the front of displays such as CRT (cathode ray tube), plasma, liquid crystal, EL (electroluminescence) has increased, It is a problem.
In order to shield electromagnetic waves generated from the front of various displays, an electromagnetic shielding structure having both electromagnetic shielding properties and transparency is attached to various displays, and the electromagnetic shielding structure is connected to an external electrode for grounding. Has been done.

  Such an electromagnetic wave shielding structure is formed by pressing an electromagnetic wave shielding film and a plastic plate. As an electromagnetic wave shielding film, for a display comprising a plastic film, an adhesive layer provided on the plastic film, and a geometrical figure drawn from a metal foil of a conductive material adhered on the adhesive layer An electromagnetic shielding film, wherein the metal foil of the conductive material has a roughened bonding surface to the adhesive layer, and the geometric figure is drawn by a chemical etching process on the metal foil. A conductive frame portion electrically connected to the geometric figure on the outer periphery of the geometric figure, and the adhesive layer flows by heating or pressurization, and It has a roughened surface that has been roughened by transferring the roughened shape by adhesion to the metal foil, and is further bonded by heating or pressing on the roughened surface of the geometric figure and the adhesive layer. Transparent layer Those provided are known.

However, the conventional electromagnetic wave shielding film produced by chemically etching the metal foil after laminating the metal foil with the roughened bonding surface to the adhesive layer and the adhesive layer is made of a roughened metal. Since the uneven surface is transferred to the adhesive layer, and the image is viewed through the adhesive layer having the unevenness, the image is not always clearly visible.
In order to overcome this problem, in Japanese Patent No. 3480898, an electromagnetic wave shielding film for display having a transparent adhesive layer to which a roughened metal surface has been transferred, specifically, a roughened metal There has been proposed a structure in which a transparent layer bonded by heating or pressurization is provided on an adhesive layer to which an uneven surface is transferred, and the surface of the adhesive layer is made transparent by wetting.
Japanese Patent No. 3480898 JP 2000-323890 A JP 2000-323891 A

In the electromagnetic wave shielding film for display disclosed in Japanese Patent No. 3480898, minute air tends to remain on the uneven surface of the adhesive layer, and the remaining air portion becomes a defective portion as a display. Moreover, no matter how much the transparent layer is bonded by heating or pressurization, when a transparent layer having a refractive index different from that of the adhesive layer is provided, the transparent layer is not completely transparent and a slight whitish color remains.
Therefore, in the present invention, as compared with a conventional method in which a blackened metal and a transparent film are laminated with an adhesive, and then a metal mesh is formed by etching, the unevenness of the transmission site (etched portion) is smaller. It aims at providing the method of manufacturing the electromagnetic wave shielding film for displays which is excellent in permeability.
Another object of the present invention is to reliably and easily provide an electromagnetic wave shielding film having high resistance.
Furthermore, this invention aims at provision of the electromagnetic wave shield display which is excellent in the transmittance | permeability.

The present invention is performed in the following order (1) to (5), and active energy ray irradiation is performed at least once between (4) and (5). Manufacturing method.
(1) Affixing a metal foil and a substrate film via an active energy ray adhesive strength disappearance type pressure-sensitive adhesive;
(2) forming a metal mesh by selective etching of the metal foil;
(3) blackening the metal foil or the metal mesh;
(4) Affixing the metal mesh surface of the laminate comprising the active energy ray-adhesive strength pressure-sensitive adhesive and the metal mesh to the transfer support, and (5) peeling the said substrate film before Symbol metal mesh.

Furthermore, it is preferable to perform active energy ray irradiation before the selective etching (2) of the metal foil .
Moreover, it is also preferable to perform active energy ray irradiation before the selective etching (2) of the metal foil, and further to perform active energy ray irradiation before peeling the base film from the metal mesh.
Moreover, it is also preferable to perform active energy ray irradiation after the selective etching (2) of the metal foil.

In the present invention, the peel strength between the metal foil and the base film is 200 g / 25 mm (90 ° peel peel) or more and 3000 g / 25 mm (90 ° peel peel) or less before irradiation with active energy rays. When peeling a material film from a metal mesh, it is preferable that it is less than 30g / 25mm (90 degree peel peeling).
Moreover, when active energy ray irradiation is performed before the selective etching (2) of the metal foil, the peel strength between the metal foil and the base film is 200 g / 25 mm (90 ° peel peel before the active energy ray irradiation). ) Or more and 3000 g / 25 mm (90 ° peel peeling) or less, and when the active energy ray irradiation is performed before the selective etching (2) of the metal foil, it is 30 g / 25 mm (90 ° peel peeling) or more and 3000 g / 25 mm. (90 ° peel peeling) or less, and when peeling the substrate film from the metal mesh, it is preferably less than 30 g / 25 mm (90 ° peel peeling).

In the present invention, when active energy ray irradiation is performed after the selective etching (2) of the metal foil, the loop tack between the metal foil and the base film is 100 g / 25 mm or more before being exposed to the etching solution. And when active energy rays are irradiated after exposure to the etching solution, it is preferably less than 100 g / 25 mm.
Moreover, it is preferable that the metal atom density | concentration on the metal mesh after peeling a base film is 50% or more.

Further, in the present invention, the active energy ray-adhesive strength pressure-sensitive adhesive preferably contains an elastic polymer having a reactive functional group, an active energy ray-reactive compound, and a curing agent, and is photopolymerized. It is more preferable to contain an initiator.

  Furthermore, this invention relates to the electromagnetic wave shielding mesh for displays manufactured with said manufacturing method. The present invention also relates to an electromagnetic wave shield display, characterized in that the electromagnetic wave shield mesh for display is bonded to the surface of the display.

The manufacturing method of the electromagnetic wave shielding mesh for displays of the present invention has the following effects. (A) Since the bonding surface does not become uneven, the surface is originally transparent, and it is not necessary to heat and press the transparent resin.
(B) In the conventional method, the metal foil whose surface has been blackened in advance is made into a geometric figure, and then the blackening treatment of the lateral surface that appears by etching is performed in a separate process. In addition, the degree of the blackening process can be adjusted by performing the blackening process on the horizontal surface at least once or more at any time.
(C) It is not necessary to use a metal foil that has been previously blackened.
(D) Even when a metal foil that has been blackened in advance is used, the same effect as (A) can be obtained after etching, and a suitable electromagnetic shielding mesh can be provided.
(E) An electromagnetic wave shield mesh having high etching resistance can be easily manufactured by adjusting the timing and number of times of active energy ray irradiation.
(F) Damage to the metal mesh opening and adhesion of foreign matter can be prevented.

First, the manufacturing method of the electromagnetic wave shielding mesh for display of this invention is demonstrated.
The present invention is a method for producing an electromagnetic wave shielding mesh for a display, wherein the following (1) to (5) are performed in an arbitrary order, and active energy ray irradiation is performed at an arbitrary number of times at an arbitrary time. is there.
(1) Affixing a metal foil and a substrate film via an active energy ray adhesive strength disappearance type pressure-sensitive adhesive;
(2) forming a metal mesh by selective etching of the metal foil;
(3) blackening the metal foil or the metal mesh;
(4) Affixing the metal mesh surface of the laminate comprising the active energy ray-adhesive pressure-reducing adhesive and the metal mesh to the transfer support, and (5) Peeling the base film from the metal foil or the metal mesh.

Although the order of said (1)-(5) is arbitrary, Preferably it is performed in order of the following (i)-(v), and it is a manufacturing method characterized by performing active energy ray irradiation.
(I) affixing a metal foil and a substrate film via an active energy ray adhesive strength disappearance type pressure-sensitive adhesive;
(Ii) forming a metal mesh by selective etching of the metal foil;
(Iii) blackening the metal mesh;
(Iv) Affixing the metal mesh surface of the laminate comprising the base film, the active energy ray adhesive strength-dissipating pressure-sensitive adhesive and the metal mesh, and the transfer support via an adhesive. And (v) peeling the base film from the metal mesh.

In the present invention, the base film is a plastic film having flexibility, typically polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, polystyrene, ethylene / vinyl acetate. Examples include polyolefins such as copolymers (EVA), vinyls such as polyvinyl chloride and polyvinylidene chloride, films such as polysulfone, polyethersulfone, polyphenylene sulfide, polycarbonate, polyamide, polyimide, acrylic resin, and cycloolefin resin. It is done.
Since the base film is peeled off after the etching step, it is sufficient if it has heat resistance and etching resistance.
The thickness of the base film is preferably about 5 to 200 μm. When the thickness is less than 5 μm, the handleability is deteriorated, and when it exceeds 200 μm, the flexibility is lost and the handleability is deteriorated.
The surface of the base film to be attached to the metal foil may be subjected to an easy adhesion treatment in order to improve the adhesion with the active energy ray adhesive strength disappearance type pressure sensitive adhesive. As the easy adhesion treatment, there are dry treatment such as corona discharge treatment, plasma treatment and flame treatment, and wet treatment such as primer treatment.

Active energy ray pressure-sensitive adhesive is a pressure-sensitive adhesive whose adhesive strength is reduced by irradiating active energy rays, and because it is pressure sensitive, it applies pressure to bond the metal foil and the base film. Let As the active energy ray adhesive strength disappearance type pressure-sensitive adhesive, those containing an elastic polymer having a reactive functional group, an active energy ray reaction ray compound, a photopolymerization initiator and a curing agent are preferably used.
In the active energy ray pressure-sensitive adhesive, a known tackifying resin, a known fine particle, a known polymerization inhibitor, a known rust inhibitor, a known plasticizer, a known ultraviolet absorber, and the like are blended. be able to.
Known tackifying resins include rosin esters. Known fine particles include inorganic fine particles such as silica compounds, and organic fine particles formed of acrylic resin or nylon resin. However, the average particle diameter of the fine particles is preferably 20 μm or less. Examples of the polymerization inhibitor include hydroquinone.

As the elastic polymer having a reactive functional group, an acrylic polymer and a urethane polymer are preferable, and examples of the reactive functional group include a carboxyl group, a hydroxyl group, an amide group, a glycidyl group, and an isocyanate group.
As an acrylic polymer, a monomer having a reactive functional group and a copolymer of another (meth) acrylic acid ester monomer, a monomer having a reactive functional group, another (meth) acrylic acid ester monomer, Copolymers with other vinyl monomers copolymerizable with the monomers can be used. The acrylic polymer is synthesized by a known method. The acrylic polymer preferably has a glass transition point of 10 ° C. or lower in order to impart tackiness. The weight average molecular weight of the acrylic polymer is preferably 200,000 to 2,000,000, more preferably 400,000 to 1,500,000 from the viewpoint of the balance between the adhesive force and the cohesive force.

As monomers having reactive functional groups, acrylic acid, methacrylic acid, itaconic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, -4 hydroxybutyl acrylate, acrylamide, glycidyl methacrylate, 2-methacryloyloxyethyl An isocyanate etc. can be mentioned.
Other (meth) acrylate monomers include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, isopropyl acrylate, acrylic acid Examples include 2-ethylhexyl, 2-ethylhexyl methacrylate, lauryl acrylate, dimethylaminomethyl methacrylate, dimethylaminoethyl methacrylate, and the like.
Examples of the other vinyl monomer copolymerizable with the (meth) acrylic acid ester monomer include vinyl acetate, styrene, α-methylstyrene, acrylonitrile, vinyltoluene and the like.

As the urethane polymer, a polymer obtained by reacting organic polyisocyanate with polyurethane polyol having a terminal hydroxyl group obtained by reacting polyol and organic polyisocyanate can be used.
Examples of the polyol include known polyester polyols and polyether polyols. Examples of the acid component of the polyester polyol include terephthalic acid, adipic acid, and azelaic acid. Examples of the glycol component include ethylene glycol, propylene glycol, and diethylene glycol. Examples of the polyol component include glycerin, totimethylolpropane, and pentaerythritol. Is mentioned. As the polyether polyol, those having 2 or more functional groups such as polypropylene glycol, polyethylene glycol, polytetramethylene glycol and the like are used. The weight average molecular weight of the polyester polyol and the polyester polyol is preferably 1000 to 5000, and more preferably 2500 to 3500. A polyester polyol and a polyester polyol having a weight average molecular weight of 1000 or less react quickly and easily gel, and a polyester polyol and a polyester polyol having a weight average molecular weight of 5000 or more have low reactivity and low cohesion. When the polyol and the organic polyisocyanate are reacted, polyvalent amines can be used in combination.

As said organic polyisocyanate, well-known aromatic polyisocyanate, aliphatic polyisocyanate, araliphatic polyisocyanate, alicyclic polyisocyanate, etc. are mentioned. Examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 4,4-diphenyl diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, and the like. Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate. Examples of the araliphatic polyisocyanate include ω, ω′-diisocyanate-1,3-dimethylbenzene, ω, ω′-diisocyanate-1,4-dimethylbenzene, ω, ω′-diisocyanate-1,4-diethylbenzene, and the like. Can be mentioned. Examples of the aliphatic polyisocyanate include isophorone diisocyanate, 1,3-cyclopentane diisocyanate, and 1,4-cyclohexane diisocyanate.
The organic polyisocyanate may be used in combination with a trimethylolpropane adduct of the organic polyisocyanate, a burette reacted with water, a trimer having an isocyanurate ring, or the like.
The weight average molecular weight of the urethane-based polymer is preferably 5,000 to 300,000, more preferably 10,000 to 200,000, from the viewpoint of the balance between adhesive force and cohesive force.

Examples of the active energy ray reaction line compound include monomers and oligomers that are three-dimensionally crosslinked by irradiation with active energy rays. These preferably have two or more acryloyl groups or methacryloyl groups in the molecule.
Examples of the monomer include 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, and the like.
Examples of the oligomer include urethane acrylate oligomers. Urethane acrylate oligomers include polyols such as polyester polyols and polyether polyols and organic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3 xylylene diisocyanate, and 1,4-xylylene diene. A terminal isocyanate prepolymer obtained by reacting isocyanate, diphenylmethane 4,4-diisocyanate, etc. with an acrylate or methacrylate having a hydroxyl group, such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, polyethylene glycol acrylate, polyethylene glycol methacrylate Further, those obtained by reacting pentaerythritol triacrylate or the like can be used. The number average molecular weight of the urethane acrylate oligomer is preferably 500 to 30,000, more preferably 1,000 to 20,000. The urethane acrylate oligomer preferably has 2 to 10 acryloyl groups or methacryloyl groups, more preferably 4 to 10, and particularly preferably 6 to 10.

  Examples of the photopolymerization initiator include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, benzoin dimethyl ketal, acetophenone dimethyl ketal, 2, 4-Diethyloxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, bisimidazole, β-chloroanthraquinone and the like can be mentioned.

  The photopolymerization initiator having a reactive functional group such as a hydroxyl group in the molecule may be blended as it is, but is preferably blended with a high molecular weight or incorporated into a polymer. The reason for this is that by increasing the molecular weight or incorporating it into the polymer, the contamination of the unreacted photopolymerization initiator on the adherend is reduced, and the photopolymerization initiator elutes into the chemical solution during the etching process and adheres after irradiation with active energy rays. It is because it can prevent that a force becomes difficult to fall. Examples of the photopolymerization initiator having a hydroxyl group as a reactive functional group include 1- (4- (2-hydroxyethoxy) phenyl) -2-hydroxy-2-methyl-1-propan-1-one (Ciba Specialty). -“Irgacure 2959” manufactured by Chemicals, Inc.).

  As a method for incorporating a photopolymerization initiator into a polymer, for example, after reacting a photopolymerization initiator having a hydroxyl group with one isocyanate group of a diisocyanate compound, for example, isophorone diisocyanate, another isocyanate group is combined with a hydroxyl group of the polymer. A method of reacting, a method of reacting an acid anhydride having a carbon-carbon double bond, such as maleic anhydride or itaconic anhydride, with a photopolymerization initiator having a hydroxyl group, and then copolymerizing with another monomer, carbon-carbon A method of reacting a compound having a double bond and an isocyanate group, such as 2-methacryloyloxyisocyanate and a photopolymerization initiator having a hydroxyl group, and then copolymerizing with another monomer, a carbon-carbon double bond and a carboxyl group. Light having a hydroxyl group with a compound having, for example, acrylic acid or methacrylic acid How copolymerized with other monomers from the initiator are reacted and the like.

  A method for increasing the molecular weight or incorporating the photopolymerization initiator into the polymer is not limited, and can be performed using a known compound and a known reaction. The destination for incorporating the photopolymerization initiator is not necessarily a polymer, but the photopolymerization initiator having a high molecular weight and the photopolymerization initiator incorporated in the polymer preferably have a weight average molecular weight of 500 to 2,000,000, and more preferably 1000 to 1.5 million is preferred. High molecular weight photopolymerization initiators having a weight average molecular weight of less than 500 and photopolymerization initiators incorporated into polymers have little effect on reducing adherence contamination and elution to chemicals, while those exceeding 2 million have increased viscosity. And productivity is bad.

The curing agent is a known isocyanate compound that reacts with an elastic polymer having a reactive functional group to give a cohesive force to the pressure-sensitive adhesive, and has reactivity to the functional group of the elastic polymer, Polyfunctional compounds such as epoxy compounds and aziridinyl compounds are used.
Isocyanate compounds include diisocyanates such as tolylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate, trimethylolpropane adducts thereof, burettes reacted with water, and isocyanurate rings. The trimer which has is mentioned.

Epoxy compounds include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, resorcin diglycidyl ether, metaxylenediamine tetra Examples thereof include glycidyl ether and hydrogenated products thereof.
Examples of aziridinyl compounds include N, N′-diphenylmethane-4,4-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β--. Examples thereof include aziridinyl propionate, N, N′-toluene-2,4-bis (1-aziridinecarboxyamide) triethylenemelamine, and the like.

As the metal foil, a foil made of a metal such as copper, aluminum, nickel, iron, gold, silver, stainless steel, tungsten, chromium, or titanium, or a foil made of an alloy combining two or more of them can be used. Copper, aluminum and nickel foils are suitable in terms of conductivity (electromagnetic shielding), ease of forming a mesh pattern, and cost. In addition, a foil made of a paramagnetic metal such as nickel, iron, stainless steel, or titanium is preferable because of its excellent magnetic shielding properties.
The thickness of the metal foil is preferably 0.5 to 40 μm. If it exceeds 40 μm, it becomes difficult to form fine lines and the viewing angle becomes narrow. On the other hand, when the thickness is less than 0.5 μm, the surface resistance increases and the electromagnetic shielding effect tends to be inferior. From the viewpoint of electromagnetic shielding properties, 1 to 20 μm is more preferable.

  Usually, when producing an electromagnetic wave shielding mesh sheet using a metal foil, a metal foil that has been blackened in advance is often used, but in the present invention, it is not always necessary to use a metal foil that has been blackened in advance. That is, in the method for producing an electromagnetic wave shielding mesh according to the present invention, the metal blackening surface for improving the contrast of the display is attached to the transfer support, so that the blackened metal foil is used from the beginning. There is no need. Of course, a blackened metal foil may be used. In other words, the method for producing an electromagnetic wave shielding mesh according to the present invention performs a blackening process after making a metal mesh, and then transfers the metal mesh to a transfer support as a final base material. The feature is that the unevenness associated with the blackening treatment is not transferred to the adhesive for affixing the support.

Depending on the timing of the blackening treatment (3) of the metal foil, the following variations of the electromagnetic shielding mesh can be produced.
(A) When the metal foil is blackened in advance, an electromagnetic wave shielding mesh in which only one surface (surface) of the metal mesh is blackened can be manufactured.
(B) Using a base material that has been previously blackened, and after the formation of the metal mesh, when the blackening treatment is further performed, the upper and lower sides (both sides) and the left and right (side surfaces) of the electromagnetic shield are blackened. Mesh can be manufactured.
(C) Using a base material that has been blackened in advance, forming a metal mesh, bonding (transferring) to the transfer support, and then performing a blackening treatment, the top and bottom of the metal mesh (front and back) ) An electromagnetic shielding mesh in which the left and right (side) four surfaces are blackened can be manufactured.
(D) When the blackening process is performed after the metal mesh is formed, an electromagnetic wave shielding mesh in which the lower (back surface), left and right (both sides) three surfaces are blackened can be manufactured.
In the above (a) to (d), the upper surface (front surface) and the lower surface (back surface) represent one side of the metal mesh. Among the above (a) to (d), (a) or (d) is preferable in the present invention.

In the present invention, the active energy ray irradiation can be performed at any time and any number of times.
Examples of active energy rays used in the present invention include electromagnetic waves such as electron beams, ultraviolet rays, and radiation. In the present invention, ultraviolet rays are preferable. The ultraviolet irradiation can be performed using a known light source such as a metal halide lamp, a high-pressure mercury lamp, an electrodeless lamp, a pulsed UV lamp, a light emitting diode lamp, or a semiconductor laser.
The active energy ray irradiation in the present invention can be performed once or a plurality of times. What is necessary is just to reach the target integrated dose by one or more times of irradiation. The integrated irradiation amount is not particularly limited as long as it can reduce the adhesive strength of the active energy ray adhesive disappearance type pressure-sensitive adhesive, but in the case of ultraviolet rays, it is preferably 20 to 3000 mJ / cm <2>, and 50 to 2000 mJ / cm <2>. Is more preferable. When the irradiation dose is less than 20 mJ / cm 2, it is difficult to eliminate the adhesive strength of the active energy ray-adhesive pressure-sensitive adhesive, and irradiation exceeding 3000 mJ / cm 2 is economically disadvantageous.

  The sticking of the metal foil and the base film in the above (1) is performed by, for example, laminating an active energy ray adhesive disappearance type pressure sensitive adhesive on one surface of the base film, for example. It can carry out by producing a carrying | supporting protective film and bonding the adhesive bond layer surface of this protective film, and metal foil. There are two methods for producing the protective film, one is a method of laminating an active energy ray pressure-sensitive adhesive directly on the base film, and the other is an active energy ray adhesive on the separator. This is a method in which a force-dissipating pressure-sensitive adhesive is applied and bonded to a base film.

Examples of the application method of the pressure-sensitive adhesive that loses the active energy ray adhesive strength include comma coat, lip coat, curtain coat, blade coat, gravure coat, kiss coat, reverse coat, and micro gravure coat. It is not limited to.
The thickness of the active energy ray-adhesive strength pressure-sensitive adhesive is preferably about 0.5 μm to 50 μm. If the thickness of the pressure sensitive adhesive is less than 0.5 μm, sufficient adhesion cannot be obtained, and if it exceeds 50 μm, it is economically disadvantageous.
Examples of a method for bonding the base film and the separator coated with the active energy ray-adhesive pressure-sensitive adhesive include room temperature lamination, heating lamination, pressure lamination, and heat pressure lamination. When air enters between the base film and the pressure-sensitive adhesive layer, the desired performance cannot be obtained, so that vacuum lamination is preferably performed.

In the formation of the metal mesh in (2) above, after forming a mesh-like etching resist pattern on the surface of the metal foil using a microlithographic method, a screen printing method, an intaglio offset printing method, etc., it is corrosive to the metal. This can be done by selectively etching the gold foil using an etchant having
Examples of the microlithographic method used for forming the etching resist pattern include a photolithographic method, an X-ray lithographic method, an electron beam lithographic method, and an ion beam lithographic method. Among these, the photolithographic method is the most efficient in terms of its simplicity and mass productivity. Among these, the photolithographic method using chemical etching is most preferable from the viewpoints of simplicity, economy, and metal mesh processing accuracy.
In the photolithography method, either negative type or positive type etching resist can be used. The etching resist ink is not particularly limited as long as the cured product has resistance to a metal etching process, and generally known photoresist compositions, photosensitive resin compositions, and thermosetting resin compositions are used. is there.

  As a method for etching the metal foil, there is a chemical etching method. The chemical etching method is a method in which a metal foil other than a portion protected by an etching resist is dissolved and removed with an etching solution. Examples of the etching solution include a ferric chloride aqueous solution, a cupric chloride aqueous solution, and an alkaline etching solution. Among these, aqueous solutions of ferric chloride and cupric chloride that are low-contamination and can be reused are preferable. The concentration of the etching solution is usually about 150 to 250 g / liter although it depends on the thickness of the metal foil and the processing speed. The liquid temperature is preferably in the range of 60 to 80 ° C. Methods for exposing the metal foil to the etchant include immersion of the metal foil in the etchant, showering of the etchant into the metal foil, exposure of the metal foil into the gas phase of the etchant, etc. From the viewpoint of stability, showering of the etching solution onto the metal foil is preferable.

  In the above (2), a step of exposing to an aqueous alkali solution is subsequently performed to remove the etching resist. The etching resist can be removed by a known method used in printed circuit board manufacture. For example, caustic soda having a concentration of 3 to 5% can be used as the alkaline aqueous solution at a temperature of 40 to 50 ° C. After the etching resist removal step, it is preferable to perform neutralization with an acid such as 3% sulfuric acid after washing with water.

  In the above (2), the metal mesh is formed by the method as described above. The unit shape constituting the mesh is a triangle such as an equilateral triangle, an isosceles triangle, a right triangle, a square, a rectangle, a rhombus, and a parallelogram. And quadrangles such as trapezoids, hexagons, octagons, dodecagons, and dodecagons (n is a positive number), circles, ellipses, and star shapes. The shape of the mesh is composed of one or more combinations of the unit shapes. As the unit shape constituting the mesh, a triangle is most effective from the viewpoint of electromagnetic shielding properties, but from the viewpoint of visible light transmittance, it is preferable that n of the n-gon is larger.

Moreover, it is preferable that the width of the line which comprises a metal mesh is 40 micrometers or less, the space | interval of a line is 100 micrometers or more, and the thickness of a line is 40 micrometers or less. Further, from the viewpoint of non-visibility of the mesh, the line width is preferably 25 μm or less, the line interval is 120 μm or more and the line thickness is 18 μm or less from the viewpoint of visible light transmittance. The line width is preferably 40 μm or less, particularly 25 μm or less, and if it is too small or thin, the surface resistance becomes too large and the shielding effect is poor, so that it is preferably 1 μm or more. The thickness of the line is preferably 40 μm or less, and if the thickness is too thin, the surface resistance becomes too large and the shielding effect is poor. The larger the line interval, the better the aperture ratio and the visible light transmittance. As described above, when used on the front surface of the display, the aperture ratio is preferably 50% or more, more preferably 60% or more. When the line interval becomes too large, the electromagnetic wave shielding property is lowered. Therefore, the line interval is preferably set to 1000 μm (1 mm) or less. Here, the aperture ratio is a percentage of the ratio of the area obtained by subtracting the area of the metal mesh from the effective area to the effective area of the electromagnetic wave shielding film.

The blackening treatment of the metal mesh in (3) can be performed using a blackening treatment liquid by a method performed in the printed wiring board field. In (3), the surface and side surfaces of the metal mesh are blackened.
The blackening treatment is performed, for example, by treating at 95 ° C. for 2 minutes in an aqueous solution of sodium chlorite (31 g / liter), sodium hydroxide (15 g / liter), and trisodium phosphate (12 g / liter). Can do.

In the attaching of the metal mesh surface and the transfer support in (4) above, for example, an adhesive-carrying transfer support is prepared by laminating an adhesive on the transfer support, and the adhesive-carrying transfer support is prepared. This can be done by transferring a metal mesh to the adhesive surface. Since the transfer support is used as a part of the display, it is preferable that the transfer support has high transparency. Specifically, it is preferable that the total light transmittance is 70% or more. The transfer support may be in the form of a flexible film / sheet or in the form of a plate having no flexibility.
Supports for transfer include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyesters such as polybutylene terephthalate, polyolefins such as polyethylene, polypropylene, polystyrene, ethylene-vinyl acetate copolymer (EVA), poly Vinyls such as vinyl chloride and polyvinylidene chloride, polysulfone, polyethersulfone, polyphenylene sulfide, polycarbonate, polyamide, polyimide, polyamideimide, polyetherimide, cycloolefin resin, acrylic resin such as polymethyl methacrylate, polyether ketone , Thermoplastic resins such as polyarylate, polyacetal, cellulose triacetate, fluororesin plate, polymethylpentene, polyurethane, diallyl phthalate resin, thermosetting A plastic film or a plastic plate such as sexual resin known film sheets include use of polyethylene terephthalate is preferable in terms of price and characteristics.

  As the transfer support, the resin can be used as a single layer, but two or more types can be laminated and used as a multilayer resin. Among the above supports, polyethylene terephthalate, polycarbonate, and cycloolefin resin are preferable from the viewpoints of transparency, heat resistance, handleability, and cost.

As the transfer support, it is also preferable to use a release paper obtained by applying a release treatment by applying silicon, fluorine, or the like on the film or sheet. Single-sided release paper when a metal mesh is attached to a transfer support by using a transfer support that uses two types of release paper with different peel strength from the transfer adhesive on the front and back of the transfer adhesive An attached electromagnetic shielding mesh is obtained.

  The thickness of the transfer support is preferably 5 to 500 μm, the appropriate thickness varies depending on the shape, and more preferably 10 to 200 μm in the case of a film shape. When the thickness is less than 5 μm, the handleability is deteriorated, and when it exceeds 500 μm, the visible light transmittance is deteriorated. In the case of a plate shape, a thickness of 5 to 500 μm is preferable from the viewpoint of display protection, strength, and handleability.

  Adhesives and transparency are required for an adhesive (hereinafter referred to as a transfer adhesive) used when attaching a metal mesh and a transfer support. When this transparency is described in detail, the electromagnetic shielding mesh produced by the method of the present invention, in which the metal mesh and the support for transfer are pasted via an adhesive, is stuck to the surface of the display. The difference in refractive index between the adhesive and the transfer support is preferably as small as possible, and is preferably about 0.1.

The transfer adhesive is generally referred to as a pressure-sensitive adhesive (pressure-sensitive adhesive) or an adhesive, and is an acrylic resin-based, urethane resin-based, blend of both, or a composite resin-based pressure-sensitive adhesive or adhesive. Can be used.
The acrylic resin transfer adhesive is composed of an acrylic resin obtained by copolymerizing a known acrylic monomer and a curing agent added for the purpose of ensuring cohesive strength, heat resistance, weather resistance, and the like. . Examples of the curing agent include isocyanate-based, epoxy-based, and aziridine-based curing agents.
Only one kind of these curing agents may be used, or two or more kinds may be used in combination.
The amount of the curing agent may be determined in consideration of the type of acrylic monomer and the adhesive strength, and is not particularly limited, but 0.1 to 15 parts by weight is added to 100 parts by weight of the acrylic resin. It is preferably 0.1 to 10 parts by weight. If the amount is less than 0.1 parts by weight, the degree of crosslinking decreases and the cohesive force becomes insufficient.

The urethane resin transfer adhesive is composed of a urethane resin obtained by reacting a known polyol with an organic polyisocyanate. The urethane resin may be obtained by reacting a polyol with a polybasic acid or an anhydride thereof and then reacting with an organic polyisocyanate.
Known polyols include one or more high molecular weight polyols, bisphenols such as bisphenol A and bisphenol F, glycols obtained by adding alkylene oxides such as ethylene oxide and propylene oxide to bisphenols, and the like. Polyols can also be used. Furthermore, compounds having two or more hydroxyl groups obtained by reacting one or more of these with other compounds such as olefins and aromatic hydrocarbons can also be used.
As organic polyisocyanate, the organic polyisocyanate illustrated as a raw material of the urethane-type polymer which comprises an active energy ray adhesive force disappearance type pressure-sensitive adhesive can be used.

A curing agent is preferably used for the urethane resin transfer adhesive. As the curing agent, an isocyanate curing agent exemplified as the curing agent constituting the active energy ray adhesive strength disappearing pressure-sensitive adhesive can be used. The amount of the curing agent may be determined in consideration of the type and adhesive strength of the urethane resin, and is not particularly limited, but 0.1 to 15 parts by weight is added to 100 parts by weight of the urethane resin. It is preferably 0.1 to 10 parts by weight. If the amount is less than 0.1 parts by weight, the degree of crosslinking decreases and the cohesive force becomes insufficient. If the amount exceeds 15 parts by weight, the adhesive force to the adherend tends to decrease, which is not preferable.
For transfer adhesives, known tackifiers, plasticizers, thickeners, antioxidants, UV absorbers, various stabilizers, wetting agents, various agents, fillers, pigments, dyes, diluents, curing accelerators Various additives such as an agent may be included. Only one type of these additives may be used, or two or more types may be appropriately used. Further, the amount of the additive added is not particularly limited as long as the desired physical properties can be obtained.

Examples of the tackifier include terpene resin, aliphatic petroleum resin, aromatic petroleum resin, coumarone-indene resin, phenol resin, terpene-phenol resin, rosin derivative (rosin, polymerized rosin, hydrogenated rosin and glycerin thereof. , Esters with pentaerythritol, resin acid dimers, etc.) can be used. In addition, an infrared absorbing material may be added to the transfer adhesive for the purpose of cutting infrared rays. Infrared absorbing materials include metal oxides such as iron oxide, cerium oxide, tin oxide, antimony oxide, indium-tin oxide (ITO), tungsten hexachloride, tin chloride, cupric sulfide, chromium-cobalt complex, Examples include thiol-nickel complexes and anthraquinones.

  Although the time and number of times of active energy ray irradiation are not particularly limited, it is preferable to irradiate before applying the transfer support to the metal mesh surface. When UV light is used as the active energy ray after the transfer support has been applied to the metal mesh surface, the adhesive layer of the transfer support is softened by the heat generated by the UV lamp, and other than the mesh part in the metal mesh surface. This is because there is a possibility that the active energy ray-adhesion-dissipating pressure-sensitive adhesive may come into contact with the exposed surface, and the peelability of the metal mesh surface may be lowered.

  In the peeling of the base film from the metal mesh in (5), the adhesive force of the pressure-sensitive adhesive for pasting the metal mesh and the base film is lowered by irradiation with active energy rays in advance before the peeling step. To do.

  Said (4 and said (5) can be performed simultaneously. That is, after reducing the adhesive force of the pressure sensitive adhesive which bonds the said metal mesh and the said base film by active energy ray irradiation, the said While peeling the base film from the metal mesh, the metal mesh can be transferred to the adhesive surface of the adhesive-carrying / transferring support, and the steps (4) and (5) are performed simultaneously. Since it can be simplified, it is economically preferable.

  The present invention is also characterized in that active energy ray irradiation can be performed at any time during the steps (1) to (5). As the timing of the active energy ray irradiation, it is preferable to irradiate the metal foil before chemical etching. The active energy ray adhesive strength disappearance type pressure-sensitive adhesive is cured by irradiation with the active energy ray, and chemical resistance to an etching solution, an alkaline solution or the like is imparted.

  The number of times of active energy ray irradiation may be one time or a plurality of times, and is not limited. Preference is given to performing active energy ray irradiation in two stages. Specifically, the first active energy ray irradiation is performed before the metal foil is chemically etched, and the second irradiation is performed before the metal mesh is peeled off. By the first irradiation, the active energy ray adhesive strength disappearance type pressure-sensitive adhesive is cured and etching resistance can be imparted. For example, when the metal foil is not irradiated before chemical etching and the etching conditions such as the etching solution type, temperature, and solution concentration are severe, the active energy ray adhesive disappearance type pressure sensitive adhesive is affected by the etching solution. Flows up to the side of the metal mesh, and the pressure-sensitive adhesive surface is damaged by chemicals such as alkaline solution and blackening solution in subsequent processes, and the adhesive strength disappears after irradiation with active energy rays. There is a risk of lack of sex.

Also, if the active energy ray irradiation before chemical etching of the metal foil is excessive, the adhesive force of the active energy ray adhesive strength disappearing pressure-sensitive adhesive is greatly reduced, and the process from etching to blackening treatment In some cases, the metal mesh peels from the pressure-sensitive adhesive that loses the adhesive strength of the active energy ray, and the electromagnetic shielding mesh cannot be manufactured.
Therefore, when the active energy ray is irradiated in two stages in the method for producing an electromagnetic wave shielding mesh of the present invention, the peel strength between the metal foil and the base film is 200 g / 25 mm (90 ° peel) before the active energy ray irradiation. Peeling) or more and 3000 g / 25 mm (90 ° peel peeling) or less, and 30 g / 25 mm (90 ° peel peeling) or more and 3000 g / when the first active energy ray irradiation is performed before selective etching of the metal foil. 25 mm (90 ° peel peeling) or less, and 30 g / 25 mm (90 ° peel peeling) when the substrate film is peeled off from the metal mesh by performing the second active energy ray irradiation after the selective etching of the metal foil. ) Is preferable.
When the peel strength before irradiation with the active energy ray is less than 30 g / 25 mm (90 ° peel peel), the metal mesh is removed from the pressure-sensitive adhesive layer that loses the active energy ray adhesive force during the process from etching to blackening treatment. There is a fear of peeling, and if it exceeds 3000 g / 25 mm (90 ° peel peeling), the peeling strength is not sufficiently lowered even when irradiated with active energy rays. Further, if the peel strength at the time of peeling the metal mesh is 30 g / 25 mm (90 ° peel peel) or more, the metal mesh formed by etching cannot be stably attached to the transfer support, and the mesh There is a risk of deformation and breakage. The second active energy ray irradiation may be performed at any time from etching to before metal mesh peeling, and may be performed a plurality of times.

  However, when the etching conditions such as the etchant type, temperature, and solution concentration are relatively gentle, the active energy ray irradiation does not necessarily have to be performed in the two steps. That is, it is also preferable to carry out after the etching and blackening process. At that time, the peel strength between the metal foil and the base film is 200 g / 25 mm (90 ° peel peel) or more and 3000 g / 25 mm (90 ° peel peel) or less before irradiation with the active energy ray. The peel strength is preferably less than 30 g / 25 mm (90 ° peel peel).

  Here, the reason why the peeling strength between the metal foil and the base film is evaluated by 90 ° peel peeling is that it is realistic peeling accuracy. Generally, there are 180 ° peeling and 90 ° peeling as peeling methods, but 180 ° is stronger than 90 °. In other words, when the base film is peeled by 180 ° peeling after the active energy ray is irradiated to reduce the adhesive strength of the pressure-sensitive adhesive, the peel strength becomes very large. On the other hand, when peeling is performed by 90 ° peeling, the peel strength is reduced. Since peeling with a peeling angle at which the peeling strength is small can be stably peeled, 90 ° peel peeling is more preferable when evaluating the peeling strength between the metal foil and the base film.

  Further, the loop tack between the metal foil and the substrate is 100 g / 25 mm or more before being exposed to an etching solution (for example, 200 g / liter aqueous solution of cupric chloride) and before irradiation with active energy rays, and the etching solution. After exposure to active energy rays, it is preferably less than 100 g / 25 mm. When the loop tack before irradiation with active energy rays is less than 100 g / 25 mm, there is a risk that the adhesion between the active energy ray adhesive strength disappearing pressure-sensitive adhesive and the metal foil is insufficient. When it exceeds 100 g / 25 mm after irradiation with active energy rays, the pressure-sensitive adhesive layer is not sufficiently lowered in adhesive force irradiation by irradiation with active energy rays, which may make it difficult to attach the metal mesh to the transfer support. The loop tack here is a method defined by “PSTC-16 Loop Tack” in the evaluation standard “TEST METHODS 14th Edition” (published Pressure Sensitive Tape Council) of adhesive tapes in the United States.

In addition, the metal on the metal after irradiating the active energy ray to the laminate in which the metal foil and the base material film are pasted via the active energy ray adhesive strength disappearance type pressure-sensitive adhesive and peeling the base material film The atomic concentration is preferably 50% or more. The metal atom concentration here is a value calculated from the abundance of metal elements on the surface of the metal foil measured by ESCA (Electron Spectroscopy for Chemical Analysis).
The metal atom concentration is based on the abundance of the metal element on the surface of the untreated metal foil, and this value is used as the denominator, and the active energy ray adhesion disappearance type pressure-sensitive adhesive is applied to one side of the metal foil. It is expressed as a percentage of a value obtained by irradiating active energy rays on the laminate to which the film is attached and peeling the base film, and using the abundance of the metal element on the surface of the metal foil as a molecule.

(Metal element abundance ratio on the surface of the metal foil after peeling the base film)
Metal atom concentration (%) = ―――――――――――――――――――――――――― × 100
(Metal element abundance ratio of untreated metal foil surface)

In the case of copper foil, which is a kind of metal foil, the copper surface is oxidized immediately, or since a rust inhibitor is applied for the purpose of suppressing oxidation, copper on the untreated copper foil surface Although the abundance of the element may not be 100%, there is no problem in calculating the metal atom concentration.

An electromagnetic wave shield mesh produced by the method of the present invention, in which a geometric figure (mesh) made of metal and a base film are attached via an adhesive, is a display such as a plasma display panel (PDP). It is pasted on the surface. Specifically, an electromagnetic wave shielding mesh is prepared by attaching an electromagnetic wave shielding mesh to at least one surface of a plastic plate or glass plate via an adhesive resin or the like. An electromagnetic wave shield display can be obtained by installing this electromagnetic wave shield constituting body on the front surface of the display. The electromagnetic wave shield mesh is preferably grounded through the conducting portion. Specifically, an electromagnetic wave shielding mesh corresponding to the size of the display is created, and its end is made into a frame shape in order to give physical strength to the electromagnetic wave shielding mesh. And it is preferable to make conduction | electrical_connection from a part of the edge part, and to ensure electromagnetic shielding property.

EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention. Moreover, evaluation was performed by the following method.
[Peel Peel Test] Evaluation was performed with a peel angle of 90 ° with reference to JIS Z 0237.
[Loop Tack Test] Evaluation was performed by the method defined in “PSTC-16 Loop Tack” in the evaluation standard “TEST METHODS 14th Edition” (published Pressure Sensitive Tape Council) of adhesive tape.
[Metal Atom Concentration] Measure the atomic concentration of the metal element using ESCA (X-ray photoelectron spectrometer, Shimadzu / Kratos “AXIS-HS”), and use the above formula from the abundance of the metal element, The metal atom concentration was calculated.
[Creation of shield mesh] The mesh shape when the formed shield mesh was transferred to the pressure sensitive adhesive carrying transfer support was observed with an electron microscope ("S-4300" manufactured by Hitachi, Ltd.), and the shield mesh maintained its shape. It was determined whether or not the transfer was possible. If the shape could be retained, it was judged acceptable, and if not, it was judged unacceptable.

Example 1
9.4 parts by weight of 2-methacryloyloxyethyl isocyanate, 1- (4- (2-hydroxyethoxy) phenyl) -2-hydroxy-2-methyl-1-propan-1-one (photopolymerization manufactured by Ciba Specialty Chemicals) Initiator "Irgacure 2959") 13.6 parts by weight, dibutyltin dilaurate 0.02 parts by weight, hydroquinone 0.02 parts by weight, methyl ethyl ketone 76.96 parts by weight in a mixed nitrogen and oxygen stream atmosphere at 80 ° C The mixture was reacted for -5 hours to obtain an intermediate solution for synthesizing a photopolymerization initiator graft polymer having a nonvolatile content of 22.5%. A mixture of 70 parts by weight of the intermediate solution, 113 parts by weight of butyl acrylate, 5 parts by weight of acrylic acid, 0.12 parts by weight of azobisisobutyronitrile, and 212 parts by weight of ethyl acetate was heated to reflux in a nitrogen atmosphere. The mixture was reacted for 7 hours to obtain a photopolymerization initiator graft polymer solution having a weight average molecular weight of 440,000 and a nonvolatile content of 33%. To 100 parts by weight of the resulting photopolymerization initiator graft polymer solution, 2.0 parts by weight of glycerol polyglycidyl ether (“Denacol EX-421” manufactured by Nagase ChemteX) as a curing agent and dimethylbenzylamine (tertiary amine) as a curing catalyst ) 0.05 part by weight, 25 parts by weight of a hexafunctional urethane acrylate oligomer ("Ebecryl 1290K" manufactured by Daicel UCB, weight average molecular weight 1000) was blended to obtain an active energy ray-adhesive pressure-sensitive adhesive.

Next, the obtained active energy ray adhesive disappearance type pressure-sensitive adhesive was applied to a 25 μm polyethylene terephthalate film (“E5100” manufactured by Toyobo Co., Ltd.) so as to have a thickness of 10 μm. A mold-type pressure-sensitive adhesive-carrying protective film was obtained.
A 12 μm copper foil (manufactured by Nikko Materials Co., Ltd.) was pressure-laminated (2 kg / cm 2) at room temperature on the obtained active energy ray-adhesive pressure-sensitive adhesive-carrying protective film. Here, the peel strength between the copper foil and the polyethylene terephthalate film was 600 g / 25 mm (90 ° peel peel).
Etching resist using a screen printing machine and a nickel alloy meshless metal plate and a squeegee on the copper foil of the laminated body in which the active energy ray adhesive strength disappearance type pressure-sensitive adhesive-carrying protective film is laminated on the copper foil (“RAYCAST” manufactured by Hitachi Chemical Co., Ltd.) was applied with a line width of 40 μm and a line interval of 250 μm. After the exposure, 200 g / liter cupric chloride aqueous solution was sprayed for 3 minutes for chemical etching to form a copper mesh pattern having a line width of 25 μm and a line interval of 250 μm. After washing with water, an aqueous caustic soda solution having a concentration of 5% was sprayed at 40 ° C. to remove the etching resist on the copper mesh. After washing with water, neutralization was performed by spraying with a 3% hydrochloric acid aqueous solution.

After washing with water, the copper mesh side of the obtained copper mesh laminate was exposed to an aqueous solution of sodium chlorite (31 g / liter) at 95 ° C. for 2 minutes to blacken the surface of the copper mesh.
Next, acrylic adhesive (Toyo Ink Manufacturing's main agent “BPS5896” and curing agent “BXX4773” blended in a weight ratio of 100: 0.5) to a 38 μm polyethylene terephthalate film (Toyobo “A4300”) Coating was performed so that the film thickness was 20 μm to obtain a support for pressure-sensitive adhesive-carrying transfer.
The obtained blackened copper mesh laminate and the pressure-sensitive adhesive-supporting transfer support were pressure-laminated (2 kg / cm 2) so that the copper mesh surface and the pressure-sensitive adhesive surface were in contact with each other. After laminating, the adhesive force disappears from the active energy ray pressure-sensitive adhesive-carrying protective film, using a metal halide lamp (UV) 120 W / cm 2 and irradiating 700 mJ / cm 2 of ultraviolet light to eliminate the pressure-sensitive adhesive pressure-sensitive adhesive. It was. Subsequently, the active energy ray adhesive strength disappearance type pressure-sensitive adhesive-carrying protective film was peeled off, and the blackened copper mesh was transferred to the pressure-sensitive adhesive surface of the pressure-sensitive adhesive-carrying support to obtain an electromagnetic wave shield mesh. . The ultraviolet illuminance was measured using an ultraviolet illuminometer UV-350 (Oak Seisakusho).

(Example 2)
A mixture consisting of 25.7 parts by weight of isophorone diisocyanate, 26.1 parts by weight of a photoinitiator “Irgacure 2959”, 0.04 parts by weight of dibutyltin dilaurate, and 148 parts by weight of ethyl acetate was added at 70 ° C.-5 under a nitrogen atmosphere. An intermediate solution for a photopolymerization initiator graft polymer having a nonvolatile content of 26% was obtained by reacting for a period of time. Meanwhile, 94.3 parts by weight of butyl acrylate, 3.2 parts by weight of 2-hydroxyethyl acrylate, 2.5 parts by weight of acrylic acid, 0.1 part by weight of azobisisobutyronitrile, 187.8 parts by weight of ethyl acetate The mixture was heated under reflux in a nitrogen atmosphere and reacted for 7 hours to obtain an acrylic polymer solution having a glass transition point of −51 ° C., a weight average molecular weight of 400,000, and a nonvolatile content of 35%. Then, a mixture of 12.9 parts by weight of the intermediate solution for the photopolymerization initiator graft polymer, 100 parts by weight of the acrylic polymer solution, and 15.0 parts by weight of ethyl acetate was heated to reflux in a nitrogen atmosphere for 7 hours. Thus, a photopolymerization initiator graft polymer solution having a nonvolatile content of 30% was obtained.
An active energy ray containing 100 parts by weight of the photopolymerization initiator graft polymer solution, 2 parts by weight of the curing agent “EX-421”, 0.05 part by weight of the curing catalyst dimethylbenzylamine, and 28 parts by weight of the urethane acrylate oligomer “Ebecry1290K”. A pressure-sensitive adhesive disappearing in adhesive strength was obtained.
An electromagnetic wave shielding mesh was obtained in the same manner as in Example 1 by using the obtained active energy ray-adhesive power loss-type pressure-sensitive adhesive.

(Example 3)
A monomer mixture consisting of 92 parts by weight of butyl acrylate, 6 parts by weight of methyl methacrylate, and 2 parts by weight of acrylic acid was heated to reflux with 0.04 parts by weight of azobisisobutyronitrile and 150 parts by weight of ethyl acetate to form nitrogen. The reaction was carried out in an atmosphere for 7 hours to obtain an acrylic polymer solution having a glass transition point of −46 ° C., an average molecular weight of 450,000, and a nonvolatile content of 40%. 1.5 parts by weight of glycerol polyglycidyl ether (“Denacol EX-421” manufactured by Nagase ChemteX) as a curing agent and 0.05 part of dimethylbenzylamine (tertiary amine) as a curing catalyst with respect to 100 parts by weight of the acrylic polymer solution Parts by weight, hexafunctional urethane acrylate oligomer ("Ebecryl 1290K" manufactured by Daicel UCB, weight average molecular weight 1000), 32 parts by weight, 2-methyl-1 (4-methylthio) phenyl) -2-morpholinopropane- as a photopolymerization initiator 1.6 parts by weight of 1-one (“Irgacure 907” manufactured by Ciba Specialty Chemicals) was blended to obtain a pressure-sensitive adhesive with loss of active energy ray adhesion.
An electromagnetic wave shielding mesh was obtained in the same manner as in Example 1 by using the obtained active energy ray-adhesive power loss-type pressure-sensitive adhesive.

Example 4
A monomer mixture composed of 91.5 parts by weight of butyl acrylate, 6 parts by weight of methyl methacrylate, 2 parts by weight of acrylic acid, and 0.5 parts by weight of 2-hydroxyethyl acrylate was added to 0.04 parts by weight of azobisisobutyronitrile. And 150 parts by weight of ethyl acetate was heated to reflux and reacted in a nitrogen atmosphere for 7 hours to obtain an acrylic polymer solution having a glass transition point of -46 ° C., an average molecular weight of 450,000, and a nonvolatile content of 40%. 1.0 part by weight of trimethylolpropane adduct of tolylene diisocyanate as a curing agent (“Coronate L” manufactured by Nippon Polyurethane), 32 parts by weight of urethane acrylate oligomer Ebecryl 1290K, Irgacure 907 1 per 100 parts by weight of the acrylic polymer solution .6 parts by weight was blended to obtain a pressure-sensitive adhesive with loss of active energy ray adhesion.
An electromagnetic wave shielding mesh was obtained in the same manner as in Example 1 by using the obtained active energy ray-adhesive power loss-type pressure-sensitive adhesive.

(Example 5)
Using the active energy ray adhesive strength disappearance type pressure sensitive adhesive obtained in Example 4, the obtained active energy ray adhesive strength disappearance type pressure sensitive adhesive was applied to a 25 μm polyethylene terephthalate film (“E5100” manufactured by Toyobo Co., Ltd.). The agent was applied to a thickness of 10 μm to obtain a pressure-sensitive adhesive-carrying protective film with loss of active energy ray adhesion.
Etching resist using a screen printing machine and a nickel alloy meshless metal plate and a squeegee on the copper foil of the laminated body in which the active energy ray adhesive strength disappearance type pressure-sensitive adhesive-carrying protective film is laminated on the copper foil (“RAYCAST” manufactured by Hitachi Chemical Co., Ltd.) was applied with a line width of 40 μm and a line interval of 250 μm. After light exposure and development, ultraviolet light of 50 mJ / cm ² was irradiated from the PET film side of the laminate using a high pressure mercury lamp (UV) 120 W / cm. Thereafter, a 200 g / liter cupric chloride aqueous solution was sprayed from the copper foil side for 3 minutes for chemical etching to form a copper mesh pattern having a line width of 25 μm and a line interval of 250 μm. After washing with water, an aqueous caustic soda solution having a concentration of 5% was sprayed at 40 ° C. to remove the etching resist on the copper mesh. After washing with water, neutralization was performed by spraying with a 3% hydrochloric acid aqueous solution.

After washing with water, the surface of the copper mesh was blackened by exposure to an aqueous solution of sodium chlorite (31 g / liter) at 95 ° C. for 2 minutes.
Next, acrylic adhesive (Toyo Ink Manufacturing's main agent “BPS5896” and curing agent “BXX4773” blended in a weight ratio of 100: 0.5) to a 38 μm polyethylene terephthalate film (Toyobo “A4300”) Coating was performed so that the film thickness was 10 μm to obtain a support for pressure-sensitive adhesive-carrying transfer.
The obtained blackened copper mesh laminate and the pressure-sensitive adhesive-supporting support were pressure-laminated (2 kg / cm ² ) so that the copper mesh surface and the pressure-sensitive adhesive surface were in contact with each other. After laminating, the adhesive strength disappears from the pressure-sensitive adhesive by irradiating 1000mJ / cm ² with UV light of 120W / cm ² from the active energy ray pressure-sensitive adhesive-carrying protective film side. I let you. Subsequently, the active energy ray adhesive strength disappearance type pressure-sensitive adhesive-carrying protective film was peeled off, and the blackened copper mesh was transferred to the pressure-sensitive adhesive surface of the pressure-sensitive adhesive-carrying support to obtain an electromagnetic wave shield mesh. .

(Comparative Example 1)
A normal pressure-sensitive adhesive that is not a loss of active energy ray adhesive strength by blending 1.5 parts by weight of the curing agent “EX-421” with respect to 100 parts by weight of the acrylic polymer solution obtained in Example 3 Obtained.
Using the obtained pressure-sensitive adhesive, an electromagnetic wave shielding mesh was prepared in the same manner as in Example 1. However, the polyethylene terephthalate film first bonded to the copper foil could not be smoothly peeled off, and force was peeled off. Then, the copper mesh was destroyed, and the desired electromagnetic shielding mesh was not obtained.

  About the laminated body which laminated | stacked the adhesive carrying | support protective film produced in Examples 1-5 and Comparative Example 1 on copper foil, the peel peeling test and loop tack test of copper foil and a base film were done. Further, the peel strength of the laminate before irradiation with active energy rays was measured in the same manner as in Example 1. Further, using a metal halide lamp (UV) 120 W / cm 2, after irradiating 700 mJ / cm 2 of ultraviolet rays, the peel strength after irradiation of active energy rays between the copper foil and the substrate film was measured. Moreover, after spraying cupric chloride aqueous solution (etching liquid) for 3 minutes to the laminated body which laminated | stacked the adhesive carrying | support protective film produced in Examples 1-4 and Comparative Example 1 on copper foil, all copper foil was melt | dissolved. Then, after washing and drying, a loop tack test was conducted after irradiating with 700 mJ / cm 2 of ultraviolet rays using a metal halide lamp (UV) 120 W / cm. Furthermore, a metal atom concentration test was performed on the surface of the metal mesh produced in Examples 1 to 5 and Comparative Example 1 from which the adhesive-carrying protective film was peeled off. The results are shown in Table 1.

It is typical sectional drawing which shows the process (1) of this invention. It is typical sectional drawing which shows the process (2) of this invention. It is typical sectional drawing which shows the process (3) of this invention. It is typical sectional drawing which shows the process (4) of this invention. It is typical sectional drawing which shows the process (5) of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal foil 2 Base film 3 Active energy ray adhesive strength disappearance type pressure-sensitive adhesive 4 Metal mesh 5 Metal mesh blackened 6 Transfer support 7 Transfer adhesive

Claims (12)

A method for producing an electromagnetic wave shielding mesh for display, which is performed in the order of the following (1) to (5), and active energy ray irradiation is performed at least once between (4) and (5).
(1) Affixing a metal foil and a substrate film via an active energy ray adhesive strength disappearance type pressure-sensitive adhesive;
(2) forming a metal mesh by selective etching of the metal foil;
(3) blackening the metal foil or the metal mesh;
(4) Affixing the metal mesh surface of the laminate comprising the active energy ray-adhesive strength pressure-sensitive adhesive and the metal mesh to the transfer support, and (5) Peeling the base film from the metal mesh. 2. The method for producing an electromagnetic wave shielding mesh for a display according to claim 1, further comprising irradiating active energy rays before the selective etching (2) of the metal foil . The active energy ray irradiation is performed before the selective etching (2) of the metal foil, and the active energy ray irradiation is further performed before the base film is peeled from the metal mesh. Manufacturing method of electromagnetic wave shielding mesh for display. 2. The method for producing an electromagnetic wave shielding mesh for a display according to claim 1, wherein the active energy ray is irradiated after the selective etching (2) of the metal foil. The peel strength between the metal foil and the base film is 200 g / 25 mm (90 ° peel peel) or more and 3000 g / 25 mm (90 ° peel peel) or less before irradiation with active energy rays, and the base film is made of metal mesh. The method for producing an electromagnetic wave shielding mesh for a display according to any one of claims 1 to 4, wherein when peeling, the thickness is less than 30 g / 25 mm (90 ° peel peeling). The peel strength between the metal foil and the base film is 200 g / 25 mm (90 ° peel peel) or more and 3000 g / 25 mm (90 ° peel peel) or less before the active energy ray irradiation, and the metal foil is selectively etched ( 2) 30 g / 25 mm (90 ° peel peeling) or more and 3000 g / 25 mm (90 ° peel peeling) or less when the active energy ray was irradiated before, and 30 g / 25 mm when peeling the base film from the metal mesh. The method for producing an electromagnetic wave shielding mesh for a display according to any one of claims 1 to 3, wherein the thickness is less than 25 mm (90 ° peel peeling). The loop tack between the metal foil and the base film is 100 g / 25 mm or more before being exposed to the etching solution, and less than 100 g / 25 mm when the active energy ray is irradiated after the exposure to the etching solution. The manufacturing method of the electromagnetic wave shielding mesh for displays of Claim 4. The method for producing an electromagnetic wave shielding mesh for a display according to any one of claims 1 to 7, wherein the metal atom concentration on the metal mesh after peeling the substrate film is 50% or more. 9. The active energy ray-adhesive strength pressure-sensitive adhesive contains an elastic polymer having a reactive functional group, an active energy ray-reactive compound, and a curing agent. The manufacturing method of the electromagnetic wave shielding mesh for displays as described in a term. 10. The method for producing an electromagnetic wave shielding mesh for a display according to claim 9, wherein the pressure-sensitive adhesive with loss of active energy ray adhesive strength further contains a photopolymerization initiator. The electromagnetic wave shielding mesh for displays manufactured by the method of any one of Claims 1-10. An electromagnetic wave shield display, wherein the electromagnetic wave shield mesh according to claim 11 is bonded to a surface of the display.

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