JP4957364B2 - Translucent conductive pattern material, electromagnetic wave shielding filter, and frequency selective electromagnetic wave shielding film - Google Patents

Description

  The present invention relates to a translucent conductive pattern material having high conductivity and translucency, and an electromagnetic wave shielding filter and a frequency selective electromagnetic wave shielding film using the same.

  In recent years, there has been a growing need to reduce electromagnetic interference (EMI) due to increased use of electronic devices. It has been pointed out that electromagnetic waves emitted from equipment cause malfunctions and failures of electronic and electrical equipment, as well as harm the human body. For this reason, electronic devices are required to suppress the intensity of electromagnetic wave emission within the standard or within the standard.

  In particular, a plasma display panel (PDP) generates electromagnetic waves in principle because it is based on the principle that a rare gas is put into a plasma state to emit ultraviolet rays and phosphors emit light with the ultraviolet rays. The electromagnetic wave shielding ability can be simply expressed by a surface resistance value, and 10 Ω / □ or less is required for a light-transmitting electromagnetic wave shielding material for PDP, and 2 Ω / □ or less for a consumer plasma television using PDP. There is a high need for this to be achieved, and extremely high conductivity of 0.2Ω / □ or less is more desirable. The mainstream of EMI prevention filters for PDP is a type in which a metal thin film is bonded to a transparent plastic support and a fine conductive mesh pattern is formed by chemical etching, and a metal thin film is formed on glass by vapor deposition. Yes, it achieves high transparency and low surface resistance. In view of the performance of high transmittance / low surface resistance, which is regarded as important as an electromagnetic wave shielding film for PDP, the etching method is excellent, and this method is adopted in many products.

  In addition, as a manufacturing method that replaces the etching method, a method for producing a conductive pattern using the sharpness of a silver salt photosensitive material (for example, see Patent Documents 1 and 2) is disclosed. In this method, an emulsion coating solution having a high silver / binder ratio is coated on a transparent substrate, a desired pattern is exposed, a metallic silver pattern is formed by processing a known photographic material, and only the pattern portion is plated by plating. It is possible to produce an electromagnetic wave shielding film for PDP without passing through a complicated process like an etching method by a method (silver salt method) that imparts high conductivity to the film.

  However, since this method is a photosensitive layer having a high silver / binder ratio and undergoes a wet and dry process during pattern formation, it is obvious that the photosensitive layer film surface is cracked and is not preferable in appearance. However, there is a possibility of causing an increase in haze and disconnection of the pattern in severe cases. Although a technique for adding various additives to the emulsion layer (for example, see Patent Documents 3 and 4) as disclosed in known silver halide methods is also disclosed, it is particularly limited. In other words, it was not out of the well-known photographic material technology. Although a technique for improving the coating property by using a specific material (for example, see Patent Document 5) for an additive, particularly a hydrophobic resin dispersion (latex) used in the present invention, is disclosed. The binder ratio is within the range of known photographic light-sensitive materials, and there is no description about changes in the film surface such as cracks.

  Furthermore, due to the recent spread of the wireless environment, there is a technology to add an electromagnetic wave shielding function to the window glass in order to maintain wireless data security and communication quality. As a result, FSS (Frequency Selective Surface) capable of shielding electromagnetic waves in a frequency selective manner is attracting attention. The feature of FSS is that a conductive independent pattern corresponding to the frequency of the electromagnetic wave to be shielded is formed on the substrate surface. Since this pattern is not continuously joined in the plane, the surface resistance is high, but each pattern itself needs high conductivity in order to reflect electromagnetic waves.

  A conductive pattern that is translucent and has frequency selectivity (shielding only electromagnetic waves in a specific frequency band) is formed on a transparent or translucent electrically insulating substrate such as glass or synthetic resin film. In addition, an antenna element pattern is known in which the frequency band desired to be shielded can be arbitrarily selected by appropriately designing the shape and density of the conductive pattern.

  Frequency selective electromagnetic shielding using an antenna element pattern is a conductive metal film such as iron, aluminum, copper, gold, nickel, etc., and a regular linear pattern with a size matched to the frequency. These antenna element patterns are conventionally formed by sputtering and etching, printing by metal paste, etc. (see, for example, Patent Documents 6 to 10), and applied to windows. Therefore, a technique for blackening a metal pattern for the purpose of improving visibility, and a technique for thinning the pattern have been disclosed.

However, the etching method is complicated and incurs high costs. In the case of printing with a metal paste, baking at a temperature close to 200 ° C. is necessary to develop high conductivity, and it is made of ordinary PET resin. Since the film is deformed, sufficient conductivity cannot be given to the pattern.
JP 2004-221564 A JP 2006-010795 A JP-A-8-286301 JP 2000-112078 A JP 2005-165005 A JP-A-10-169039 Japanese Patent Laid-Open No. 11-195890 Japanese Patent Laid-Open No. 11-251784 JP 2000-196288 A JP 2001-53484 A

  Accordingly, an object of the present invention is to provide a light-transmitting conductive pattern material that has high conductivity and light-transmitting property, and that does not cause cracks on the film surface even when treated by wet and dry, and an electromagnetic wave shielding filter using the same. It is to provide a frequency-selective electromagnetic wave shielding film.

  The above object of the present invention is achieved by the following configurations.

1. A silver halide photosensitive layer is provided on a transparent plastic support, and the silver halide photosensitive layer is exposed and chemically developed to form a metal silver pattern, and then the conductivity is improved by physical development, plating, or plating after physical development. In the light-transmitting conductive pattern material produced by amplification, the silver halide photosensitive layer contains a hydrophilic polymer and a hydrophobic polymer, and the hydrophobic polymer is a water-dispersible latex. A translucent conductive pattern material having an average particle diameter of 200 nm or less and a ratio R1 / R2 of the refractive index R1 of the hydrophilic polymer and the refractive index R2 of the hydrophobic polymer satisfies the following formula .
1.0 ≦ R1 / R2 ≦ 1.1

  2. 2. The translucent conductive pattern material according to 1 above, wherein the silver halide photosensitive layer has a silver / binder mass ratio of 4 to 20.

  3. 3. The translucent conductive pattern material as described in 1 or 2 above, wherein the haze is 5% or less and the visible light transmittance is 90% or more.

4). 4. The translucent conductive pattern material according to any one of 1 to 3 , wherein the hydrophobic polymer is contained in an amount of 5 to 40% by mass with respect to the hydrophilic polymer.

5. 5. The translucent conductive pattern according to any one of 1 to 4 , wherein the hydrophobic polymer includes a low Tg polymer having Tg ≦ 0 ° C. and a high Tg polymer having Tg ≧ 50 ° C. material.

6). 6. The translucent conductive pattern material according to 5 , wherein the high Tg polymer is contained in an amount of 10 to 30% by mass relative to the low Tg polymer.

7). 7. The translucent conductive pattern material according to any one of 1 to 6 , wherein a dry film thickness of only the binder of the silver halide photosensitive layer is 50 to 500 nm.

8). 8. The translucent conductive pattern material according to any one of 1 to 7 , wherein the silver halide photosensitive layer is an outermost layer.

9. 9. An electromagnetic wave shielding filter using the translucent conductive pattern material according to any one of 1 to 8 above, wherein the conductive pattern is a continuous pattern.

10. A frequency-selective electromagnetic wave shielding film using the translucent conductive pattern material according to any one of 1 to 8 above, wherein the conductive pattern is an independent pattern that reflects an electromagnetic wave having a specific frequency.

  According to the present invention, the drawing performance of a fine line pattern is improved without going through a complicated process such as etching, and further, there is no occurrence of cracks even after going through a wet and dry treatment process, optical performance such as transmittance, haze, It has become possible to provide a light-transmitting conductive pattern material excellent in both pattern conductivity, an electromagnetic wave shielding filter using the same, and a frequency-selective electromagnetic wave shielding film.

  Hereinafter, the best mode for carrying out the present invention will be described in detail.

[Electromagnetic wave shielding filter]
First, an aspect as an electromagnetic wave shielding filter for PDP (plasma display panel) will be described.

  In general, a conductive mesh, an etching mesh, a film on which a conductive printing mesh is formed, a transparent conductive film, or the like is used as an electromagnetic wave shielding filter for PDP.

  The conductive mesh is preferably, for example, one having a wire diameter of 1 to 100 μm and an aperture ratio of 60 to 95% in order to improve light transmission and prevent moire phenomenon. When the wire diameter exceeds 40 μm, the aperture ratio decreases, and when the wire diameter is lower than 1 μm, the electromagnetic wave shielding performance is lowered, and at the same time the establishment of a disconnection defect is increased. A preferable wire diameter is 10 to 30 μm, and an aperture ratio is 70 to 90%. The aperture ratio of a mesh means the area ratio which the opening part occupies in the projection area of the said mesh.

  As an etching mesh, a metal film of copper, aluminum, stainless steel, chromium, etc. is formed on a transparent base film such as PET, PC, PMMA, etc., and etched into an arbitrary shape such as a grid or punching metal using a photolithography technique. Can be used. Moreover, you may use what bonded metal foil to the transparent base film with adhesives, such as an epoxy type and a urethane type.

  Also, gravure obtained by mixing non-metallic conductive particles such as silver, copper, aluminum, nickel, etc., or non-metallic conductive particles such as carbon, with binders such as epoxy, urethane, EVA, melanin, cellulose, acrylic, etc. A conductive printing mesh printed in a pattern such as a lattice pattern on a transparent base film such as PET, PC, or PMMA by printing, offset printing, screen printing, or the like can be used.

  Moreover, as a transparent conductive film, what formed the transparent conductive layer in the resin film which disperse | distributed electroconductive particle, or a base film can be used.

  In the present invention, in particular, in order to maintain the aperture ratio and the wire diameter, from a conductive pattern master provided with a silver halide photosensitive layer (a layer containing silver salt particles), this is exposed to a mesh pattern and chemically developed. After processing to form a metallic silver pattern, a silver mesh whose conductivity is amplified by physical development, plating or plating after physical development is used.

[Frequency selective electromagnetic shielding film]
Next, FSS (Frequency Selected Surface) that shields only electromagnetic waves of a specific frequency will be described.

  FSS is a technology that can shield only electromagnetic waves of a specific frequency by forming a linear antenna pattern corresponding to the electromagnetic waves of a specific frequency on the surface of the equipment and resonantly reflecting only the electromagnetic waves of the specific frequency. In the linear antenna element, the end is opened, and the length (electric length) of one side extending from the center is set to ¼ wavelength (1/2 wavelength in one shape) of the radio wave to be shielded. In this way, resonance is made with the wavelength to be shielded. Further, it may be an annular line shape similar to the wavelength of the radio wave to be shielded from the perimeter (electric length).

  The arrangement interval is determined between the linear antenna elements in consideration of the relationship of attenuation. That is, the electromagnetic field reflection equivalent area (scattering aperture area) or the electromagnetic field reflection equivalent volume (scattering aperture volume) of the element is arranged to scatter and attenuate radio waves.

When a half-wavelength (λ / 2) linear antenna element (dipole) placed parallel to a plane electromagnetic field, for example, a linear antenna element 1 (dipole) as shown in FIG. 1, the linear antenna element 1 is an antenna. Not only the area occupied by the conductor (metal) part reflects the energy of the incident electromagnetic wave 2 but reflects a certain range of electromagnetic fields in the vicinity of the metal part (reflected electromagnetic wave 3). This is the electromagnetic field reflection equivalent sectional area 4 (scattering aperture area; Ae≈0.13λ ² (area of λ / 2 × λ / 4)) or the electromagnetic field reflection equivalent volume 5 (scattering aperture volume).

Accordingly, electromagnetic shielding can be performed by arranging the linear antenna elements in a plane or in a three-dimensional manner in space or on a non-conductive material in consideration of these. As the linear antenna element, it is necessary to select a material with low volume resistivity and loss (desirably 5 × 10 ⁻⁸ (Ω · m) or less), and for example, a metal material such as silver is preferable. The pattern of the antenna element is spaced and does not cover the entire surface, so that translucency and visibility are not impaired. Accordingly, it is preferable that the thickness of the conducting wire of the linear antenna element is thin and has little loss so as not to disturb the field of view.

  Patterned small linear antenna elements can be shielded from specific frequencies by specifying their length, and as a result, other radio waves can be passed through, so it is possible to collect information from outside such as radio and TV radio waves. Necessary radio waves are not shielded, but only specific radio waves can be shielded.

  In actual radio waves, the plane of polarization is not uniform and has various inclinations. However, by making the linear antenna element into an annular line shape or an open end with directionality, any polarization plane can be obtained. It can also be made to handle radio waves.

  The present invention is a conductive pattern in which a mesh pattern of an electromagnetic wave shielding filter for PDP requiring high conductivity or a linear antenna pattern such as FSS is provided, and a photosensitive layer containing silver halide grains is provided on a support. This is prepared by exposing a desired conductive pattern to the original plate, performing a chemical development treatment to form a metallic silver pattern, and further performing physical development, plating, or plating after physical development. is there.

[Silver halide photosensitive layer]
The conductive pattern master used to produce the conductive patterned film according to the present invention is a photosensitive material, a silver halide photographic emulsion is used as an optical sensor, and the silver halide grains are used as a binder resin such as gelatin. A dispersed silver halide photosensitive layer is coated on a support. The silver halide photosensitive layer can contain a binder, a solvent and the like in addition to the silver salt.

(Silver salt)
Examples of the silver salt include inorganic silver salts such as silver halide and organic silver salts such as silver acetate, but it is preferable to use silver halide having excellent characteristics as an optical sensor.

  The silver halide preferably used in the present invention will be further described.

  In the silver halide used in the present invention, the silver halide emulsion technique used in silver salt photographic film, photographic paper, printing plate-making film, photomask emulsion mask and the like can be used as it is.

  The halogen element contained in the silver halide may be any of chlorine, bromine, iodine and fluorine, or a combination thereof. For example, silver halide mainly composed of AgCl, AgBr, and AgI is preferably used, and silver halide mainly composed of AgCl is preferably used.

  Here, “silver halide mainly composed of AgCl (silver chloride)” refers to silver halide in which the molar fraction of chloride ions in the silver halide composition is 50% or more. The silver halide grains mainly composed of AgCl may contain bromide ions and iodide ions in addition to chloride ions.

  Silver halide is in the form of solid grains. From the viewpoint of image quality of the patterned metallic silver layer formed after exposure and chemical development, the average grain size of silver halide is 0.1 to 1000 nm in terms of sphere equivalent diameter. It is preferable that it is 0.1-100 nm, and it is more preferable. The sphere equivalent diameter of silver halide grains is the diameter of grains having the same volume and having a spherical shape.

  The shape of the silver halide grains is not particularly limited. For example, various shapes such as a spherical shape, a cubic shape, a flat plate shape (hexagonal flat plate shape, triangular flat plate shape, tetragonal flat plate shape, etc.), octahedral shape, tetrahedral shape, etc. Can be.

The silver halide used in the present invention may further contain other elements. For example, in a photographic emulsion, it is also useful to dope metal ions used to obtain a high-contrast emulsion. In particular, transition metal ions such as rhodium ions and iridium ions are preferably used because a difference between an exposed portion and an unexposed portion tends to occur clearly when a metallic silver image is generated. Transition metal ions represented by rhodium ions and iridium ions can also be compounds having various ligands. Examples of such a ligand include cyanide ions, halogen ions, thiocyanate ions, nitrosyl ions, water, hydroxide ions, and the like. Specific examples of the compound include K ₃ Rh ₂ Br ₉ and K ₂ IrCl ₆ .

In the present invention, the content of the rhodium compound and / or iridium compound contained in the silver halide is 10 ⁻¹⁰ to 10 ⁻² mol / mol Ag with respect to the number of moles of silver in the silver halide. Preferably, it is 10 ⁻⁹ to 10 ⁻³ mol / mol Ag.

  In addition, in the present invention, silver halides containing Pd (II) ions and / or Pd metals can also be preferably used. Pd may be uniformly distributed in the silver halide grains, but is preferably contained in the vicinity of the surface layer of the silver halide grains. Here, Pd “contains in the vicinity of the surface layer of the silver halide grains” means that the Pd content is higher than the other layers within 50 nm in the depth direction from the surface of the silver halide grains. means. Such silver halide grains can be prepared by adding Pd in the course of forming silver halide grains. After adding silver ions and halogen ions to 50% or more of the total addition amount, Pd Is preferably added. It is also preferred that Pd (II) ions be present in the surface layer of the silver halide by a method such as addition at the time of post-ripening.

  The Pd-containing silver halide grains increase the speed of physical development and electroless plating, increase the production efficiency of a desired electromagnetic shielding material, and contribute to the reduction of production cost. Pd is well known and used as an electroless plating catalyst. However, in the present invention, Pd can be unevenly distributed on the surface layer of silver halide grains, so that extremely expensive Pd can be saved. is there.

In the present invention, the content of Pd ions and / or Pd metal contained in the silver halide is preferably 10 ⁻⁸ to 10 ⁻⁴ mol / mol Ag with respect to the number of moles of silver in the silver halide, More preferably, it is 10 ⁻⁶ to 10 ⁻⁵ mol / mol Ag. Further, in order to suppress the binding with gelatin and coordinate more efficiently to AgX, it is preferably added as a Pd (SCN) ₂ complex or palladium glycinate.

Examples of the Pd compound used include PdCl ₄ and Na ₂ PdCl ₄ .

  In the present invention, in order to further improve the sensitivity as an optical sensor, chemical sensitization performed with a photographic emulsion can be performed. As chemical sensitization, for example, noble metal sensitization such as gold sensitization, chalcogen sensitization such as sulfur sensitization, reduction sensitization or the like can be used.

(Hydrophilic polymer)
In the present invention, the binder (resin) can be used for the purpose of uniformly dispersing the silver salt particles and assisting the adhesion between the silver salt-containing layer and the support. In the present invention, both a hydrophilic polymer and a hydrophobic polymer can be used as a binder. However, as a main binder (a resin occupying 50% by volume or more of all binder components), a hydrophilic high It is preferable to use molecules (water-soluble binder).

  Examples of the water-soluble binder include gelatin, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), starch and other polysaccharides, cellulose and derivatives thereof, polyethylene oxide, polyvinylamine, chitosan, polylysine, polyacrylic acid, polyalginic acid. , Polyhyaluronic acid, carboxycellulose and the like. These have neutral, anionic, and cationic properties depending on the ionicity of the functional group.

  Since a photographic silver halide gelatin emulsion is used as the silver halide grains, gelatin is most preferred in the binder resin.

  Examples of gelatin include lime-processed gelatin, acid-processed gelatin, and various modified gelatins such as phthalated gelatin and phenylcarbamoylated gelatin.

  The amount of the binder contained in the silver halide photosensitive layer according to the present invention is not particularly limited and can be appropriately determined within a range in which dispersibility and adhesion can be exhibited. The binder content in the silver halide photosensitive layer is preferably 4 to 20 in terms of silver / binder mass ratio. If the silver halide photosensitive layer contains a binder in a silver / binder mass ratio of 4 or more, the metal particles can easily come into contact with each other in the physical development and / or plating process, and high conductivity can be obtained. preferable.

(Hydrophobic polymer)
The coating liquid of the present invention contains a hydrophobic polymer in addition to the hydrophilic polymer and water described above. As the hydrophobic polymer, an aqueous dispersion (latex) of a hydrophobic resin can be contained.

  In order to ensure transparency, the latex used in the present invention has an average particle diameter of 200 nm or less, and the ratio R1 / R2 of the refractive index of the hydrophilic polymer and the refractive index of the dispersed hydrophobic polymer is R1 / R2. It is necessary to satisfy the following formula.

1.0 ≦ R1 / R2 ≦ 1.1
The translucent conductive pattern material of the present invention preferably has a haze of 5% or less, but when a latex having an average particle size (dispersion average particle size) larger than 200 nm is used, the refractive index with the hydrophilic binder is used. Even if the ratio is within the above relationship, non-uniformity larger than the visible light wavelength size exists, so it is difficult to reduce the haze after film formation to 5% or less, and the dispersion average particle size is Even if it is 200 nm or less, if the refractive index ratio is outside the above range, scattering of visible light occurs, and it becomes difficult to make the haze after film formation 5% or less.

  If the above relationship is satisfied, the resin can be used without any particular limitation, but it does not affect the silver halide and is generally easy to obtain and inexpensive. Therefore, acrylic resin, vinylidene chloride resin, vinyl acetate It is preferable to use a latex using a resin whose main component is a resin. Moreover, it is preferable that the addition amount of hydrophobic resin shall be 5-40 mass% with respect to hydrophilic resin. If the amount is less than 5% by mass, the effect of adding the hydrophobic resin cannot be obtained. If the amount added is 40% by mass or more, the presence of silver halide grains tends to become non-uniform after film formation.

  In addition, the hydrophobic polymer contains a low Tg polymer having a Tg ≦ 0 ° C. and a high Tg polymer having a Tg ≧ 50 ° C. in order to prevent cracking, adherence to the substrate, and pressure fogging of silver halide. Two or more types of polymers are preferably included. The low Tg polymer alone has an effect on cracking and adhesion, but the film becomes too flexible, so when external force is applied to the silver halide layer, a large force is applied to the silver halide grains, making it photosensitive. Even if not, the so-called pressure fog that forms developed silver increases. When a low Tg polymer is added, the hardness of the film increases, so that external force can be dispersed in the lateral direction of the film, so that pressure fogging can be prevented, but cracks are rather worsened.

  Furthermore, in order for the average refractive index of two or more composite hydrophobic resins to satisfy the relationship with the refractive index of the hydrophilic resin, the mass of the high Tg polymer is 10 to 10% of the mass of the low Tg polymer. It is preferably contained in the range of 30% by mass. High Tg polymers generally have a high refractive index. When the mass of the high Tg polymer exceeds 30% by mass with respect to the mass of the low Tg polymer, the relationship between the refractive index and the hydrophilic polymer. Therefore, it becomes difficult to reduce the haze after film formation to 5% or less.

(solvent)
The solvent used in the silver halide photosensitive layer of the present invention is not particularly limited. For example, water, organic solvents (for example, alcohols such as methanol, ketones such as acetone, amides such as formamide, Sulfoxides such as dimethyl sulfoxide, esters such as ethyl acetate, ethers, etc.), ionic liquids, and mixed solvents thereof. Since photographic silver halide gelatin emulsions are used, water-based solvents are preferred.

(Coating of silver halide photosensitive layer)
In the production of the conductive pattern master of the present invention, a coating solution corresponding to the silver halide photosensitive layer is prepared by an ordinary coating method such as a dip coating method, a slide coating method, or a bar coating method, which is known in photographic methods. What is necessary is just to apply | coat on a support body. In order to improve wettability and adhesion to the support, an easy-adhesion layer known in photographic methods may be provided in advance, and further known plasma treatment and flame treatment represented by glow discharge and corona discharge. May be applied.

[Transparent plastic support]
In the present invention, a plastic film, a plastic plate, or the like is used as a transparent plastic support (hereinafter also simply referred to as a support) used for a conductive pattern-equipped film, and hence a conductive pattern original (silver halide photosensitive material). However, the material of the support that can be used in the conductive pattern film of the present invention is preferably one that can be processed into a flexible sheet or roll.

  Examples of raw materials for plastic films and plastic plates include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefins such as polyethylene (PE), polypropylene (PP), polystyrene and EVA, polyvinyl chloride, and polychlorinated chloride. Use vinyl resins such as vinylidene, polyether ether ketone (PEEK), polysulfone (PSF), polyether sulfone (PES), polycarbonate (PC), polyamide, polyimide, acrylic resin, triacetyl cellulose (TAC), etc. Can do.

  From the viewpoint of transparency, heat resistance, ease of handling and price, the plastic film is preferably a polyethylene terephthalate film.

  Since transparency is required for a display, it is desirable that the support has high transparency. The total visible light transmittance of the plastic film or plastic plate is preferably 70 to 100%, more preferably 90 to 100%. %. A plastic film (eg, cellulose acetate film, polyester film, polyethylene terephthalate film, polyethylene naphthalate film, polyamide film, polyimide film, cellulose triacetate film, or polycarbonate film) is used.

  As a support body of the electroconductive pattern material of this invention, thickness of 70-180 micrometers is preferable, More preferably, it is 80-120 micrometers.

  In order to reduce curling and curling, the polyester support is 0.1% in the temperature range below the glass transition temperature after film formation of the polyester support as described in JP-A-51-16358. Heat treatment for ˜1500 hours may be performed to reduce curling.

(exposure)
In the present invention, the silver halide photosensitive layer provided on the support is exposed. The exposure can be performed using electromagnetic waves. Examples of the electromagnetic wave include light such as visible light and ultraviolet light, and radiation such as X-rays. Furthermore, a light source having a wavelength distribution may be used for exposure, or a light source having a specific wavelength may be used.

  Examples of the light source include scanning exposure using a cathode ray tube (CRT). The cathode ray tube exposure apparatus is simpler and more compact and less expensive than an apparatus using a laser. Also, the adjustment of the optical axis and color is easy. As the cathode ray tube used for image exposure, various light emitters that emit light in the spectral region are used as necessary. For example, one or more of a red light emitter, a green light emitter, a blue light emitter, and a near infrared light emitter are used. The spectral region is not limited to the above-mentioned near infrared, red, green, and blue, and a phosphor that emits light in the yellow, orange, purple, or infrared region is also used. In particular, a cathode ray tube that emits white light by mixing these light emitters is often used. An ultraviolet lamp is also preferable, and g-line of a mercury lamp, i-line of a mercury lamp, etc. are also used.

In the present invention, exposure can be performed using various laser beams. For example, a monochromatic high-density light such as a gas laser, a light emitting diode, a semiconductor laser, a semiconductor laser, or a second harmonic light source (SHG) that combines a nonlinear laser and a solid state laser using a semiconductor laser as an excitation light source was used. A scanning exposure method can be preferably used, and a KrF excimer laser, an ArF excimer laser, an F ₂ laser, or the like can also be used. In order to make the system compact and inexpensive, the exposure is preferably performed using a semiconductor laser, a semiconductor laser, or a second harmonic generation light source (SHG) that combines a solid-state laser and a nonlinear optical crystal. In order to design an apparatus that is particularly compact, inexpensive, long-life, and highly stable, it is preferable to perform exposure using a semiconductor laser.

  As the laser light source, specifically, a blue semiconductor laser having a wavelength of 430 to 460 nm (Nichia Chemical presentation at the 48th Applied Physics Related Conference in March 2001) is preferably used.

  The method for exposing the silver halide photosensitive layer in a pattern may be performed by surface exposure using a photomask or by scanning exposure using a laser beam. At this time, refractive exposure using a lens or reflection exposure using a reflecting mirror may be used, and exposure methods such as contact exposure, proximity exposure, reduced projection exposure, and reflection projection exposure can be used.

(Chemical development processing)
In the present invention, the chemical developing process is further performed after exposing the original plate for an electromagnetic wave shielding material having a silver halide photosensitive layer. The chemical development processing can be performed by a general chemical development processing technique used for silver salt photographic film, photographic paper, printing plate-making film, photomask emulsion mask, and the like. The developer is not particularly limited, but a PQ developer, MQ developer, MAA developer, etc. can also be used. For example, CN-16, CR-56, CP45X, FD-3, Papitol manufactured by FUJIFILM Corporation Developers such as C-41, E-6, RA-4, D-19, and D-72 manufactured by KODAK, Inc., or developers included in kits thereof, and lith developers such as D-85 are used. be able to.

  In the present invention, by performing the above exposure and chemical development treatment, a metallic silver portion, preferably a patterned metallic silver portion, is formed, and a light transmissive portion described later is formed.

  The chemical development process in the present invention can include a fixing process performed for the purpose of removing and stabilizing the silver salt in the unexposed part. For the fixing process in the present invention, a fixing process technique used for a silver salt photographic film, photographic paper, a printing plate-making film, a photomask emulsion mask, or the like can be used.

  The developer used in the chemical development processing can contain an image quality improver for the purpose of improving the image quality. Examples of the image quality improver include nitrogen-containing heterocyclic compounds such as benzotriazole. In addition, it is also preferable to use polyethylene glycol, particularly when a lith developer is used.

  In order to obtain high conductivity, the mass of metallic silver contained in the exposed portion after chemical development is 50% by mass or more based on the mass of silver contained in the exposed portion before exposure. It is preferably 80% by mass or more.

  The gradation after chemical development in the present invention is not particularly limited, but is preferably more than 4.0. When the gradation after the chemical development processing exceeds 4.0, the conductivity of the conductive metal portion can be increased while keeping the transparency of the light transmissive portion high. Examples of means for setting the gradation to 4.0 or higher include the aforementioned doping of rhodium ions and iridium ions.

  In order to obtain a pattern made of a metal film having sufficient conductivity, the metal silver pattern formed from the conductive pattern master is further subjected to physical development, plating or plating after physical development using this as a core. It is preferable to apply.

  By physical development or plating treatment, sufficient conductivity can be imparted to the metallic silver pattern obtained by the first development treatment, and the light transmittance can be kept high.

(Physical development and plating)
In the present invention, physical development and / or plating treatment is performed on the metallic silver for the purpose of further adding conductivity to the conductive antenna element pattern made of metallic silver formed by the exposure and chemical development processing to reduce loss. It is preferable to further carry conductive metal particles.

  “Physical development” in the present invention means that metal particles such as silver ions are reduced with a reducing agent on metal or metal compound nuclei to deposit metal particles. This physical phenomenon is used for instant B & W film, instant slide film, printing plate manufacturing, and the like, and the technology can be used in the present invention.

  Further, the physical development may be performed simultaneously with the development processing after exposure or separately after the development processing.

  In the present invention, the plating process can be performed using electroless plating (chemical reduction plating or displacement plating), electrolytic plating, or both electroless plating and electrolytic plating.

  When the patterns in the present invention are continuously joined, the surface resistance is reduced to 300Ω / □ or less, preferably 150Ω / □ or less by physical development, and then electroplating is performed to obtain a desired surface resistance value. It is preferable to finish. In electrolytic plating, it is possible to plate a fine pattern with good selectivity by appropriately adjusting the current density, the ion concentration of the electrolytic solution, the processing temperature, and the processing time. Electrolytic plating is preferable because, in principle, the plating metal can be deposited only on the portion where current flows, and therefore, the plating selectivity is excellent in principle.

  In the case of plating in the present invention, when each pattern is independent, after reducing the resistivity of the pattern to 1000 μΩm or less by physical development, a plating catalyst such as Pd is replaced with silver on the pattern surface as necessary. The resistivity of the pattern can be made 100 to 1 μΩm by electroless plating. Chemical species contained in the electroless copper plating solution include copper sulfate and copper chloride, formalin and glyoxylic acid as the reducing agent, EDTA and triethanolamine as the copper ligand, and other bath stabilization and plating film Examples of the additive for improving the smoothness include polyethylene glycol, yellow blood salt, and bipyridine. Examples of the electrolytic copper plating bath include a copper sulfate bath and a copper pyrophosphate bath. In order to improve the selectivity of plating, it is preferable to perform bubble stirring with air or nitrogen.

  The plating speed at the time of plating in the present invention can be performed under moderate conditions, and high-speed plating of 5 μm / hour or more is also possible. In the plating treatment, various additives such as a ligand such as EDTA can be used from the viewpoint of improving the stability of the plating solution.

  In addition, the silver halide photosensitive layer according to the present invention contains a hydrophobic polymer. By containing the hydrophobic polymer, the same amount of binder can be produced using only a hydrophilic polymer (for example, gelatin). It was found that the conductivity amplification by physical development and plating easily proceeds as compared with the case of the above.

  The reason is not clear, but I guess as follows. When viewed microscopically, the silver halide grains are dispersed only in the hydrophilic polymer, and the metallic silver formed after chemical development is also present only in the hydrophilic polymer. Since the physical developing solution and the plating solution are aqueous solutions, it is considered that the physical developing solution and the plating solution penetrate only into the hydrophilic polymer portion and the silver precipitation reaction and the plating metal precipitation reaction occur. In such a state, the amplification of conductivity proceeds. Therefore, in the conductivity amplification treatment by the aqueous treatment, when materials of the same amount of binder are compared, the material containing the hydrophobic polymer is substantially (described above). Since silver / binder is in a high state, it is considered that the progress of conductivity amplification is facilitated.

(Oxidation treatment)
In the present invention, oxidation treatment is preferably performed on the metallic silver portion after chemical development and the conductive metal portion formed after physical development and / or plating. By performing the oxidation treatment, for example, when a metal is slightly deposited on the light transmissive portion, the metal can be removed and the light transmissive portion can be made almost 100% transparent.

  Examples of the oxidation treatment include known methods using various oxidizing agents such as Fe (III) ion treatment. The oxidation treatment can be performed after exposure and development processing of the silver salt-containing layer, or after physical development or plating treatment, and may be performed after development processing and after physical development or plating treatment.

  In the present invention, the metallic silver portion after the exposure and development treatment can be further treated with a solution containing Pd. Pd may be a divalent palladium ion or metallic palladium. This treatment can accelerate electroless plating or physical development speed.

(Conductive metal part)
Next, the pattern which consists of an electroconductive metal part formed in this invention is demonstrated.

  In the present invention, the conductive metal pattern is exposed to the pattern and then subjected to chemical development treatment, and the metal silver pattern formed by the chemical development treatment is subjected to physical development or plating treatment so that the metal silver portion is electrically conductive. It is formed by supporting the conductive metal particles.

  In the present invention, metallic silver is preferably formed in the exposed portion in order to increase transparency.

  In addition to the silver described above, the conductive metal particles supported on the metallic silver portion by physical development and / or plating treatment are copper, aluminum, nickel, iron, gold, cobalt, tin, stainless steel, tungsten, chromium, titanium. , Palladium, platinum, manganese, zinc, rhodium and other metals, or alloys of these in combination. From the viewpoint of conductivity, cost, etc., copper, aluminum or nickel particles are preferred. Moreover, when providing magnetic field shielding, it is preferable to use a paramagnetic metal particle.

  In the conductive metal part, from the viewpoint of enhancing contrast and preventing oxidation and fading over time, the conductive metal part contained in the conductive metal part is preferably a copper particle, and the surface thereof is black. More preferably, it has been subjected to a chemical treatment. The blackening treatment can be performed using a method performed in the printed wiring board field. For example, blackening treatment is performed by treating at 95 ° C. for 2 minutes in an aqueous solution of sodium chlorite (31 g / L), sodium hydroxide (15 g / L), and trisodium phosphate (12 g / L). Can do.

  The conductive metal part preferably contains 50% by mass or more, and more preferably 60% by mass or more of silver with respect to the total mass of the metal contained in the conductive metal part. If silver is contained in an amount of 50% by mass or more, the time required for physical development and / or plating can be shortened, productivity can be improved, and cost can be reduced.

  Furthermore, when copper and palladium are used as the conductive metal particles forming the conductive metal part, the total mass of silver, copper and palladium is 80% by mass or more based on the total mass of the metal contained in the conductive metal part. It is preferable that it is 90 mass% or more.

  Since the conductive metal portion in the present invention carries conductive metal particles, good conductivity can be obtained. For this reason, in the case of an independent pattern, the resistivity of the pattern is preferably 100 μΩm or less, and more preferably 1 μΩm or less. Further, when a mesh pattern continuously bonded in-plane as an electromagnetic wave shielding film for PDP is prepared, the surface resistance value is preferably 103Ω / □ or less, more preferably 2.5Ω / □ or less. Preferably, it is 1.5Ω / □ or less, and most preferably 0.1Ω / □ or less.

  In the conductive pattern, the conductive metal part preferably has a line width of 20 μm or less and a line interval of 50 μm or more. The conductive metal portion may have a portion whose line width is wider than 20 μm for the purpose of ground connection or the like. Further, from the viewpoint of making the image inconspicuous, the line width of the conductive metal part is preferably less than 18 μm, more preferably less than 15 μm, further preferably less than 14 μm, and less than 10 μm. Even more preferably, it is most preferably less than 7 μm.

  The conductive metal portion in the present invention has an aperture ratio of preferably 85% or more, more preferably 90% or more, and most preferably 95% or more from the viewpoint of visible light transmittance. When the conductive pattern is an electromagnetic wave shielding film for PDP, for example, the aperture ratio is the ratio of the portion without fine wires forming the mesh to the whole. For example, the aperture ratio of a square grid mesh with a line width of 10 μm and a pitch of 200 μm Is 90%.

(Light transmissive part)
The “light transmissive part” in the present invention means a part having transparency other than the conductive metal part in the light transmissive electromagnetic wave shielding material. As described above, the visible light transmittance in the light transmissive portion is 90% or more, preferably the transmittance indicated by the minimum value of the transmittance in the wavelength region of 380 to 780 nm excluding the contribution of light absorption and reflection of the support. Is 95% or more, more preferably 97% or more, even more preferably 98% or more, and most preferably 99% or more.

  The light-transmitting part in the present invention is formed together with the metallic silver part in the unexposed part by exposing and chemically developing the halogenated photosensitive layer. From the viewpoint of improving the transmittance, the light transmissive portion is preferably subjected to an oxidation treatment after the chemical development treatment, and further after a physical treatment or a plating treatment.

(Layer structure of translucent conductive pattern material)
The thickness of the support in the translucent conductive pattern material of the present invention is preferably 5 to 200 μm, and more preferably 30 to 150 μm. If it is the range of 5-200 micrometers, the transmittance | permeability of a desired visible light will be obtained and handling will also be easy.

  Since the silver halide photosensitive layer is subjected to physical development and / or plating after chemical development, it is preferably the outermost layer of the translucent conductive pattern material.

  The thickness of the metallic silver portion provided on the support before physical development and / or plating can be appropriately determined by the coating thickness of the coating solution for the halogenated photosensitive layer applied on the support. The thickness of the metallic silver part is preferably 30 μm or less, more preferably 20 μm or less, further preferably 0.01 to 9 μm, and most preferably 0.05 to 5 μm. Moreover, it is preferable that a metal silver part is pattern shape.

  As an application of the electromagnetic wave shielding material for the display, the thinner the conductive metal part, the wider the viewing angle of the display, which is preferable. As the conductive wiring material, thinning and high density are required, and from such a viewpoint, the thickness of the layer made of the conductive metal supported on the conductive metal part is preferably less than 9 μm, It is more preferably 0.1 μm or more and less than 5 μm, and further preferably 0.1 μm or more and less than 3 μm.

  In the present invention, a metal silver portion having a desired thickness is formed by controlling the coating thickness of the above-mentioned halogenated photosensitive layer and physical development and / or plating, and the thickness of the layer made of conductive metal particles can be freely adjusted. Therefore, even a conductive pattern having a thickness of less than 5 μm, preferably less than 3 μm can be easily formed.

  The translucent conductive pattern material of the present invention forms a conductive pattern by amplifying the conductivity of the metal silver pattern portion by physical development and plating by forming metallic silver in the exposed portion. The thickness of the unexposed portion of the layer (the portion without the conductive pattern) is preferably 50 to 500 nm, and more preferably 100 to 300 nm. If the thickness is less than 50 nm, the holding property of the conductive pattern deteriorates. If the thickness exceeds 500 nm, a minute film thickness unevenness causes Newton's ring due to light interference, and it becomes easy to recognize as a rainbow-colored unevenness.

(Functions other than conductive pattern)
In the translucent conductive pattern material of the present invention, a functional layer may be separately provided as necessary. For example, as an electromagnetic shielding material for displays, an antireflection layer with an adjusted refractive index and film thickness, an antiglare layer, a near infrared absorption layer, an ultraviolet absorption layer, and a color tone adjustment functional layer that absorbs visible light in a specific wavelength range. An antifouling layer, a hard coat layer, a shock absorbing functional layer, and the like can be provided. These functional layers may be provided on the opposite side of the conductive pattern-containing layer (silver halide photosensitive layer) and the support, or may be provided on the same side. These functional layer films can be appropriately selected according to the purpose.

  Since the translucent conductive pattern material of the present invention has good electromagnetic shielding properties and light transmissivity, it can be used as a translucent electromagnetic shielding material. Moreover, it can also be used as various conductive wiring materials such as circuit wiring. In particular, the translucent electromagnetic wave shielding film of the present invention is applied not only to the front filter of the PDP but also to the front surface of a display such as CRT (cathode ray tube), liquid crystal, EL (electroluminescence), microwave oven, electronic equipment, printed wiring board, etc. It can be used suitably.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented.

Examples Preparation of silver halide fine grain emulsion
The following solution A was kept at 34 ° C. in a reaction vessel, and the pH was adjusted to 2.95 using nitric acid (concentration 6%) while stirring at high speed using a mixing and stirring device described in JP-A-62-2160128. It was adjusted. Subsequently, the following solution B and the following solution C were added at a constant flow rate over 8 minutes and 6 seconds using the double jet method. After completion of the addition, the pH was adjusted to 5.90 using sodium carbonate (concentration 5%), and then the following solution D and solution E were added.

(Solution A)
Alkali-treated inert gelatin (average molecular weight 100,000) 18.7g
Sodium chloride 0.31g
Solution I 1.59ml
Pure water 1246ml
(Solution B)
169.9g of silver nitrate
Nitric acid (concentration 6%) 5.89ml
Finish to 317.1 ml with pure water (Solution C)
Alkali-treated inert gelatin (average molecular weight 100,000) 5.66 g
Sodium chloride 58.8g
13.3 g of potassium bromide
Solution I 0.85ml below
Solution II below 2.72 ml
Finish to 317.1 ml with pure water (Solution D)
2-Methyl-4hydroxy-1,3,3a, 7-tetraazaindene 0.56 g
112.1 ml of pure water
(Solution E)
Alkali-treated inert gelatin (average molecular weight 100,000) 3.96 g
Solution I 0.40ml
128.5 ml of pure water
(Solution I)
Surfactant: 10% by weight methanol solution of polyisopropylene polyethylene oxydisuccinate sodium salt (Solution II)
10% by mass aqueous solution of rhodium hexachloride complex After the above operation is completed, desalting and water washing are performed using a flocculation method at 40 ° C. according to a conventional method, and the following solution F and antibacterial agent are added, and may be 60 ° C. After dispersion, the pH was adjusted to 5.90 at 40 ° C., and finally a silver chlorobromide cubic grain emulsion having an average grain diameter of 0.09 μm and a variation coefficient of 10% containing 10 mol% of silver bromide was obtained. . The silver / binder mass ratio of this emulsion was 4.7.

(Solution F)
Alkali-treated inert gelatin (average molecular weight 100,000) 16.5g
Pure water 139.8ml
(Underdrawn PET film support)
The both sides of a 100 μm biaxially stretched PET support were subjected to a corona discharge treatment of 12 W · min / m ² , and the following undercoat coating solution B1 was applied to each surface so as to have a dry film thickness of 0.1 μm. Then, a corona discharge treatment of 12 W · min / m ² was performed, and the following undercoat coating solution B2 was applied to a dry film thickness of 0.06 μm. Thereafter, heat treatment was performed at 120 ° C. for 1.5 minutes to obtain an underdrawn PET film support.

<Undercoat coating liquid B1>
Copolymer latex liquid of 20 parts by mass of styrene, 40 parts by mass of glycidyl methacrylate and 40 parts by mass of butyl acrylate (solid content: 30%) 50 g
SnO ₂ sol 440g
Compound (UL-1) 0.2g
Finish with water 1000ml
<Undercoat coating liquid B2>
10g gelatin
Compound (UL-1) 0.2g
Compound (UL-2) 0.2g
Silica particles (average particle size 3μm) 0.1g
Hardener (UL-3) 1g
Finish with water 1000ml
SnO ₂ sol (Synthesis example of SnO ₂ sol)
65 g of SnCl ₄ .5H ₂ O was dissolved in 2000 ml of distilled water to obtain a homogeneous solution, which was then boiled to obtain a precipitate. The formed precipitate was taken out by decantation and washed with distilled water many times. Silver nitrate was added dropwise to distilled water in which the precipitate was washed, and after confirming that there was no reaction of chlorine ions, distilled water was added to the washed precipitate to make a total volume of 2000 ml. To this, 40 ml of 30% aqueous ammonia was added and heated to obtain a uniform sol. Further, while adding ammonia water, the solution was concentrated by heating until the solid content concentration of SnO ₂ became 8.3%, thereby obtaining a SnO ₂ sol.

[Preparation of conductive pattern material master]
<Preparation of conductive pattern material master 1 (Comparative Example 1)>
After adding Na ₂ PdCl ₄ to the prepared emulsion and further performing sulfur sensitization with sodium thiosulfate, together with the hardener (UL-3), the silver coating amount is 1 g / m ^2. Then, after coating and drying on the undercoated PET film support, a curing process was performed at 55 ° C. for 20 hours to prepare an original plate 1 for conductive pattern material. The dry film thickness of only the binder was 152 nm.

<Preparation of conductive pattern material master 2 (Example 1)>
16.5 g of gelatin added at the end of the preparation of the emulsion was changed to 15.2 g, and 1.3 g (20% by mass of dispersion 6) of the following latex 1 was added at the timing of adding a hardener (UL-3). 0.5 g) A conductive pattern material master 2 was prepared in the same manner as the conductive pattern material master 1 except that it was added. This photosensitive layer has a binder composition in which a hydrophobic polymer is contained in an amount of 20% with respect to gelatin which is a hydrophilic polymer. The dry film thickness of only the binder was 152 nm.

(Latex 1)
Butyl acrylate / vinylidene chloride = 50/50
Tg = −29 ° C.
Refractive index = 1.44
Average particle size = 150 nm
Solid content = 20%
R1 / R2 = 1.06 (gelatin R1 = 1.52, latex 1 resin R2 = 1.44)
<Preparation of conductive pattern material master 3 (Example 2)>
Except that the hydrophobic polymer to be added was changed to 1.1 g of latex 1 in solid content and the following latex 2 to 0.2 g in solid content (4.44% by weight dispersion liquid 4.54 g). In the same manner as in Example 2, a conductive pattern material original plate 3 was produced.

(Latex 2)
Vinyl acetate / vinyl pivalate = 50/50 (colloidal silica composite)
Tg = 59 ° C
Refractive index = 1.46
Average particle size = 200 nm
Solid content concentration = 4.4% by mass
R1 / R2 = 1.04 (gelatin R1 = 1.52, latex mixed resin R2 = 1.46)
<Preparation of conductive pattern material master 4 (Example 3)>
A conductive pattern material master 4 was produced in the same manner as the conductive pattern material master 3 except that the amount of silver was changed to 4 g / m ² . The dry film thickness of only the binder was 610 nm.

<Preparation of conductive pattern material master 5 (Comparative Example 2)>
A conductive pattern material master 5 was produced in the same manner as the conductive pattern material master 1 except that the amount of silver was changed to 4 g / m ² . The dry film thickness of only the binder was 610 nm.

<Preparation of conductive pattern material master 6 (Comparative Example 3)>
16.5 g of gelatin added at the end of preparation of the above emulsion was changed to 14.1 g, and 2.4 g of latex 1 (20% by weight dispersion 12.0 g) was added at the timing when gelatin hardener was added. A conductive pattern material original plate 6 was produced in the same manner as the conductive pattern material original plate 2 except that. This silver halide photosensitive layer has a binder structure in which the hydrophobic polymer is contained in an amount of 44% by mass with respect to gelatin, which is a hydrophilic polymer.

<Preparation of conductive pattern material master 7 (Comparative Example 4)>
The hydrophobic polymer to be added is the same as the conductive pattern material master 3 except that the latex 1 is changed to 0.7 g in solid content and the latex 2 is changed to 0.6 g in solid content. Was made.

[Production of electromagnetic wave shielding film for PDP]
The produced conductive pattern material masters 1 to 7 were exposed using an ultraviolet lamp through a lattice-like photomask having a line width of 8 μm and a distance between lines of 300 μm. At this time, for the measurement evaluation, the 1 cm width of the end portion of the sample was irradiated with light through a raw glass instead of a lattice pattern. Next, after developing for 30 seconds at 35 ° C. using the following developer (DEV1), fixing treatment for 60 seconds was performed at 35 ° C. using the following fixing solution (FIX1), followed by washing with water. . Furthermore, physical development was performed at 30 ° C. for 5 minutes using the following physical developer (PD1), followed by washing with water. Then, after cutting a sample into A4 size, the electrolytic copper plating process was performed at 25 degreeC using the plating liquid (EPL1). The current control in the electrolytic copper plating was performed at 3A for 1 minute, then at 1A for 9 minutes, for a total of 10 minutes. In this way, transparent electromagnetic wave shielding films having metal mesh layers (referred to as SF-1 to 7 respectively) were produced.

(DEV1: Developer)
500 ml of pure water
Metol 2g
80 g of anhydrous sodium sulfite
Hydroquinone 4g
4g borax
Sodium thiosulfate 10g
Potassium bromide 0.5g
Add water to bring the total volume to 1 liter (FIX1: Fixer)
750 ml of pure water
Sodium thiosulfate 250g
Anhydrous sodium sulfite 15g
Glacial acetic acid 15ml
Potash alum 15g
Add water to bring the total volume to 1 liter (PD1: Physical developer)
800ml of pure water
Citric acid 31g
Hydroquinone 7.8g
Disodium hydrogen phosphate 1.1g
Ammonia water (28%) 2.2ml
Silver nitrate 1.5g
Add water to bring the total volume to 1 liter (EPL1: Electrolytic plating solution)
Copper sulfate (pentahydrate) 200g
50g of sulfuric acid
Sodium chloride 0.1g
Add water to make the total volume 1 liter [Evaluation of electromagnetic wave shielding film for PDP]
The PDP electromagnetic shielding films SF-1 to SF-7 produced as described above were evaluated by the following methods. The results are shown in Table 1.

(Visible light transmittance, haze)
The transmittance (integrated value) and haze (ratio of scattered light in the transmitted light) in the visible light region (360 to 700 nm) were measured using a Hitachi spectrophotometer U-4000 type. The higher the transmittance (%) and the smaller the haze (%), the higher the transparency without haze.

(Surface resistance)
Four-terminal measurement was performed using a resistivity meter (Loresta GP (MCP-T610 type): manufactured by Dia Instruments Co., Ltd.). An EPS type probe was used as the probe.

(Crack test)
An unexposed conductive pattern material master conditioned at 23 ° C. and 55% RH for 24 hours is cut into a strip of 10 cm width and 1 m length, and halogenated at a winding tension of 39.2 N (3.92 N / cm). The silver photosensitive layer surface was wound outwardly and wound around a paper core having an inner diameter of 3 inches. Each was sealed with a polysheet and placed in a 55 ° C. oven for 15 hours. Then, after being left for 15 hours in an environment of 23 ° C. and 55% RH, exposure to plating was performed as described above to produce an electromagnetic wave shielding film for PDP. Thus, the visible light transmittance, haze, and surface resistance of the electromagnetic wave shielding film subjected to the crack test treatment were measured by visual observation of the presence or absence of cracks and the above-described methods.

(Adhesion)
Adhesion was carried out according to the cross-cut adhesion test method of JIS-K5600-5-6. The cellophane tape includes cellophane tape No. manufactured by Nitto Denko Corporation. 29 was used. Use a cutter to make 11 scratches at 1mm vertical and horizontal intervals to make 100 squares of 1mm square (cross cut), and after attaching cellophane tape to the cross cut part, peel test in the direction of about 60 ° above Went. This test was repeated three times, and the average value of the number of cells that did not peel was determined. It shows that adhesiveness is so favorable that this numerical value is large.

(Scratch resistance)
The sample was fixed on a horizontal desk, steel wool was rubbed 10 times with a load of 0.49 N / cm ² to make a scratch, and the haze of the damaged portion was measured by the method described above. The haze increase rate (%) was calculated by dividing the value by the value when there was no scratch, and the evaluation was performed according to the following criteria.

○: 100 to less than 110% Δ: 110 to less than 120% ×: 120% or more

  The sample of the present invention has a high transmittance and a low haze of 5% or less, and is excellent in transparency, is free from cracks, and has no haze increase due to cracks or scratches. Further, the surface resistance is further lowered by the same time treatment, and the treatment time can be shortened when designing to the same surface resistance.

[Fabrication of Frequency Selective Electromagnetic Wave Shielding Film SSF-1 (Example 4)]
As the antenna element pattern having a reflection characteristic of 2.5 G band (2.45 GHz; wavelength 122 mm) using the conductive pattern material original plate 3, the linear antenna element (unit length 61 mm) shown in FIGS. After exposing the antenna element pattern to a line width of 15 μm after plating and a linear antenna element interval of 300 μm using a glass mask having a line width of 8 μm, and performing physical development in the same manner as the production of the electromagnetic wave shielding film for PDP. The following EPL2 electroless copper plating solution was subjected to an electroless copper plating treatment at 45 ° C. for 10 minutes, followed by an oxidation treatment with an aqueous solution containing 10 ppm of Fe (III) ions, and a frequency selective electromagnetic shielding film. (SSF-1) was produced.

(EPL2; electroless plating solution)
Copper sulfate 0.06mol / L
Formalin 0.22 mol / L
Triethanolamine 0.12 mol / L
Polyethylene glycol 100ppm
Yellow blood salt 50ppm
α, α'-Bipyridine 20ppm
pH = 12.5
[Fabrication of Frequency Selective Electromagnetic Wave Shielding Film SSF-2 (Example 5)]
Similarly to SSF-1, a frequency selective electromagnetic wave shielding film SSF-2 having an antenna element pattern in which only the unit length of the element was 29.2 mm so as to correspond to the frequency of 5.15 GHz was produced.

[Evaluation of Frequency Selective Electromagnetic Wave Shielding Film (Example 4)]
About the frequency selective electromagnetic wave shielding film, in addition to the same evaluation as the electromagnetic wave shielding film for PDP, the transmission attenuation characteristic of the electromagnetic wave was measured by the following method.

(Evaluation of electromagnetic wave transmission attenuation rate)
FIG. 3 is a schematic diagram showing the arrangement of apparatuses in the transmittance attenuation rate evaluation method.

  A vector network analyzer (HP 8150B) is connected to a pair of dielectric lenses 1 and 2 placed facing each other, and a film sample cut to a size of 20 cm square is placed between each selective electromagnetic wave shielding film. Then, an electromagnetic wave having a design frequency was made incident, and the attenuation rate (dB) of the electromagnetic wave of each wavelength was measured from the intensity of the incident electromagnetic wave (2.5 GHz, 5.1 GHz, and 10 GHz, respectively) and the intensity of the transmitted electromagnetic wave.

  Table 2 shows the evaluation results of the frequency selective electromagnetic shielding film.

  As is apparent from the above, the translucent conductive pattern material of the present invention is excellent in transparency (high visible light transmittance and low haze), has high efficiency of conductive intensification treatment, and can shorten the treatment time. . Furthermore, it has become possible to produce a translucent conductive pattern material that is excellent in adhesion and scratch resistance and that can be handled easily even after a fine conductive pattern is produced.

  Moreover, also when it is set as the electromagnetic wave shielding film for PDP which requires a fine conductive pattern, and a frequency selective electromagnetic wave shielding film, preparation of the film with the high electromagnetic wave shielding ability according to the objective is possible.

It is a figure which shows reflection of a linear antenna element and electromagnetic waves. It is a figure which shows some examples of the electromagnetic wave reflective surface which has an antenna element pattern. It is a schematic diagram showing arrangement | positioning of the evaluation apparatus of an attenuation factor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Linear antenna element 2 Incident electromagnetic wave 3 Reflected electromagnetic wave 4 Electromagnetic field reflection equivalent cross-section 5 Electromagnetic field reflection equivalent volume

Claims (10)

A silver halide photosensitive layer is provided on a transparent plastic support, and the silver halide photosensitive layer is exposed and chemically developed to form a metal silver pattern, and then the conductivity is improved by physical development, plating, or plating after physical development. In the light-transmitting conductive pattern material produced by amplification, the silver halide photosensitive layer contains a hydrophilic polymer and a hydrophobic polymer, and the hydrophobic polymer is a water-dispersible latex. A translucent conductive pattern material having an average particle diameter of 200 nm or less and a ratio R1 / R2 of the refractive index R1 of the hydrophilic polymer and the refractive index R2 of the hydrophobic polymer satisfies the following formula .
1.0 ≦ R1 / R2 ≦ 1.1   2. The translucent conductive pattern material according to claim 1, wherein the silver halide photosensitive layer has a silver / binder mass ratio of 4 to 20.   The translucent conductive pattern material according to claim 1 or 2, wherein the haze is 5% or less and the visible light transmittance is 90% or more. The translucent conductive pattern material according to any one of claims 1 to 3 , wherein the hydrophobic polymer is contained in an amount of 5 to 40% by mass with respect to the hydrophilic polymer. Wherein the hydrophobic polymer, translucent conductive according to any one of claims 1 to 4, characterized in that it comprises a low Tg polymer and Tg ≧ 50 ° C. High Tg polymer of Tg ≦ 0 ° C. Pattern material. The translucent conductive pattern material according to claim 5 , wherein the high Tg polymer is contained in an amount of 10 to 30% by mass with respect to the low Tg polymer. The translucent conductive pattern material according to any one of claims 1 to 6 , wherein the dry film thickness of only the binder of the silver halide photosensitive layer is 50 to 500 nm. Translucent conductive pattern material according to any one of claims 1 to 7, wherein the silver halide light-sensitive layer, characterized in that the outermost layer. An electromagnetic wave shielding filter using the translucent conductive pattern material according to any one of claims 1 to 8 , wherein the conductive pattern is a continuous pattern. The frequency-selective electromagnetic wave shielding film using the translucent conductive pattern material according to any one of claims 1 to 8 , wherein the conductive pattern is an independent pattern that reflects an electromagnetic wave having a specific frequency.

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