JP2007067270A - Electromagnetic wave shielding material roll body and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic wave shielding material to be fed in a roll which has less partial variations in performance of an electromagnetic wave shield and has stable performance, even if the lateral width dimension of a wound roll of a mesh pattern has a width of about 600 mm-1,600 mm in photographic silver-plating method, and to provide a manufacturing method thereof. <P>SOLUTION: The electromagnetic wave shielding material roll body is provided with the a metal mesh pattern 22, on at least one surface of a long transparent base material 21, and is fed in a rolled state. The metal mesh pattern 22 has a developing silver mesh pattern generated by a photographic process and a non-electrolytic plating layer laminated thereon, and the lateral width dimension of the wound roll of the metal mesh pattern 22 is 600-1,600 mm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electromagnetic wave shielding material and a manufacturing method thereof. More specifically, it is supplied in rolls used for manufacturing optical filters for various displays such as CRT and PDP (plasma display), and covering large areas such as window glass of large buildings. The present invention relates to an electromagnetic shielding material and a manufacturing method thereof.

  In recent years, in various displays such as CRT and PDP (plasma display), electromagnetic waves generated from the front of the display adversely affect the human body and malfunction of surrounding electronic devices has become a problem. Along with the clearness of the display, countermeasures against the influence of the display on the surroundings are becoming increasingly important. Furthermore, with the widespread use of wireless LAN, it is necessary to prevent communication data in the building from being leaked to the outside of the building and intercepted, and countermeasures against electromagnetic wave shielding are becoming important.

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

Furthermore, as a method for producing an electromagnetic wave shielding material using a conductive metal mesh, the following methods (1) to (3) are exemplified.
(1) An etching method in which a metal foil is bonded to a transparent substrate, or a metal thin film is deposited on the transparent substrate, and then a conductive metal pattern is formed by a photolithographic method (see, for example, Patent Document 1).
(2) A printing-plating method in which a conductive metal paste is printed on a transparent substrate and then plated to form a conductive metal pattern (see, for example, Patent Document 2).
(3) A photographic silver-plating method for forming a conductive metal pattern by forming a fine line pattern with metallic silver developed by a photographic method and then physically developing and / or plating the metallic silver (for example, Patent Document 3) And Patent Document 4).

  Then, there are two methods shown in the following (a) and (b) for forming a mesh pattern with metallic silver by a photographic manufacturing method.

(A) A silver salt-containing layer containing a silver salt provided on a support is exposed and developed to form a metallic silver part and a light-transmitting part, and the metallic silver part is further subjected to physical development and A method of forming a conductive metal part in which conductive metal particles are supported on the metal silver part by plating (see, for example, Patent Document 3). In this method, phenomenon silver does not appear in the portion that is covered with the exposure mask and is not exposed, and developed silver appears in the portion that is not covered with the exposure mask and exposed. Therefore, compared with the exposure mask. This is a negative exposure / development method in which developed silver appears in an inverted form.

(B) A light-sensitive material having a physical development nucleus layer and a silver halide emulsion layer in this order is exposed on a transparent substrate, and metallic silver is deposited on the physical development nucleus in an arbitrary fine line pattern. A method of plating a metal using the physically developed metallic silver as a catalyst nucleus after removing a layer provided on the development nucleus (see, for example, Patent Document 4). In this method, phenomenon silver appears in a portion that is covered with an exposure mask and is not exposed, and developed silver does not appear in a portion that is not covered with the exposure mask and is exposed. Is a positive exposure / development method (silver complex diffusion transfer method, hereinafter referred to as DTR method).
Japanese Patent Laid-Open No. 10-075087 JP 11-170420 A JP 2004-221564 A WO2004 / 007810

  In the etching method (1), it is a problem from the viewpoint of saving resources that only a very small portion which becomes a thin line portion is left by etching and most other metals are dissolved and removed. Moreover, when bonding metal foil, since it is calculated | required that the surface roughness of metal foil is small, the metal foil manufactured by the electrolytic method instead of the rolling method is used. However, when the metal foil is bonded to the transparent substrate, the metal foil is removed by etching because the surface side having the irregularities of the metal foil is bonded to the transparent substrate in order to improve the adhesion strength with the substrate. Unevenness remains on the surface of the transparent substrate. For this reason, in order to prevent light scattering, there has been a problem in that it is necessary to perform a transparent treatment for filling the unevenness with a transparent resin to make it flat. In addition, when a metal thin film is deposited, there is a problem that it cannot be easily manufactured because a huge equipment cost is required.

In the printing-plating method (2), it is difficult to reduce the line width of the mesh pattern to 30 μm or less, and there is a problem in that the adhesiveness between the transparent substrate and the mesh pattern is poor and is easily peeled off.
In the photographic silver-plating method of (3) above, high electromagnetic shielding properties are obtained, and there is no restriction on the dimensions of the transparent base material, so that it can be produced with a roll-to-roll and the productivity is very high. This is a preferred production method.

  By the way, in the photographic silver-plating method, a fine line pattern is formed by electroless plating and / or electrolytic plating on the metal silver having a mesh pattern developed by any of the photographic methods (a) and (b). In the case of electrolytic plating, the plating rate is faster than that of electroless plating, but the metal silver mesh pattern developed by the photographic method needs to have sufficiently high conductivity. When the electrical conductivity is low, there is a problem in that an electrolytic current required for performing electrolytic plating does not flow, and defective electrolytic plating occurs. In addition, when electrolytic plating is performed, if the roll winding width dimension (roll width dimension) of the mesh pattern becomes wider than about 600 mm, the distance between the power supply rolls arranged at both ends of the roll becomes long, and the mesh pattern passes through the mesh pattern. The current carrying resistance of the electrolysis current becomes excessive. For this reason, in the photographic silver-plating method, when the roll width of the mesh pattern becomes wider than about 600 mm, it is technically difficult to perform electrolytic plating uniformly on the developed silver constituting the mesh pattern. There was a problem. In addition, since the roll width dimension of the film normally used as a transparent base material is about about 1600 mm at the maximum, it is necessary to solve said subject in the range whose roll width dimension is about 600 mm-1600 mm.

  The present invention has been made in view of the above circumstances. In the photographic silver-plating method, even if the roll winding width of the mesh pattern is as wide as about 600 mm to 1600 mm, a partial performance of the electromagnetic wave shielding is achieved. It is an object of the present invention to provide a roll-supplied electromagnetic wave shielding material with little variation and stable performance, and a method for manufacturing the same.

  In order to solve the above problems, the present invention is an electromagnetic wave shielding material roll body provided with a metal mesh pattern on at least one surface of a long transparent base material and supplied in a roll state, wherein the metal mesh pattern Has a developed silver mesh pattern generated by a photographic method and an electroless plating layer laminated thereon, and the roll width of the metal mesh pattern is 600 to 1600 mm. An electromagnetic shielding material roll is provided.

The electroless plating layer is preferably an electroless copper plating layer or an electroless nickel plating layer.
It is preferable that an electrolytic plating layer is further laminated on the electroless plating layer.
As the developed silver mesh pattern, either a negative-type development method in which developed silver appears in the exposed portion or a positive-type development method in which developed silver appears in the unexposed portion is adopted. It is also possible to do.

  Further, the present invention is a method for producing an electromagnetic shielding material roll body in which a metal mesh pattern is provided on at least one surface of a long transparent substrate and is supplied in a roll state, wherein the transparent substrate is continuously formed. A developed silver mesh pattern having a roll winding width of 600 to 1600 mm is generated on at least one surface of the transparent substrate by a photographic method, and then an electroless plating layer is formed on the developed silver mesh pattern. Then, a method for producing an electromagnetic shielding material roll body is provided, which is wound up again to form a roll body.

After the development silver mesh pattern is generated, it is preferable that the electroless plating is continuously performed while the surface of the transparent substrate is kept wet.
The electroless plating is preferably electroless copper plating or electroless nickel plating.
After the electroless plating, an electrolytic plating layer is preferably laminated on the electroless plating layer.
The developed silver mesh pattern can be generated by either a negative developing method in which developed silver appears in the exposed portion or a positive developing method in which developed silver appears in the unexposed portion.

According to the present invention, in the photographic silver-plating method, even when the roll winding width of the mesh pattern is as wide as about 600 mm to 1600 mm, the electromagnetic shielding with stable performance with little variation in the performance of the electromagnetic shielding. It is possible to manufacture a material roll body. Since the electromagnetic shielding material can be continuously produced and supplied by roll-to-roll, the production cost can be significantly reduced.
When the developed silver mesh pattern is generated by the photographic process and then electroless plating is performed while the surface of the transparent substrate is kept moist, the microbubbles adhere to the surface of the developed silver mesh pattern and the electroless plating solution It is possible to reduce the cause of poor plating by interfering with the contact.

The present invention will be described below with reference to the drawings based on the best mode.
FIG. 1 is a schematic view showing an example of an apparatus for performing electroless plating subsequent to an exposure / development process using roll-to-roll in the present invention. FIG. 2 is a schematic view showing an example of an apparatus for performing electroless plating and electrolytic plating following the exposure / development process using roll-to-roll in the present invention. FIG. 3 is a partial plan view showing an example of the arrangement of the mesh pattern and the continuous feeding layer in the electromagnetic wave shielding material roll of the present invention. FIG. 4 is a partial plan view showing another example of the arrangement of the mesh pattern and the continuous feeding layer in the electromagnetic wave shielding material roll of the present invention. FIG. 5 is a partial plan view showing an example of the arrangement of mesh patterns and power feeding layers in a conventional electromagnetic wave shielding material for a display.

  In the electromagnetic shielding material manufacturing apparatus 1 shown in FIG. 1, an original fabric roll 2 is a roll sheet 3 in which a layer (details will be described later) containing a substance that deposits metallic silver by exposure and development is provided on a long transparent substrate. Is rolled up into a roll. The roll sheet 3 fed out from the raw roll 2 is transferred from left to right in the figure by transfer rolls 4, 4, 4,. The roll sheet 3 is first transferred to the exposure device 5 and baked (exposed) with a predetermined mask pattern. Next, the developed silver which has been transferred to the developing device 6 and has been photographic developed is fixed in a mesh pattern shape. Next, after passing through the water cleaning tank 7 and cleaning, unnecessary foreign matters and contaminants are removed, and then transferred to the electroless plating tank 8.

  In the electroless plating tank 8, electroless plating is performed through the electroless plating solution 9, and an electroless plating layer is deposited on the developed silver mesh pattern on the surface of the roll sheet 3. The temperature of the electroless plating solution 9 is controlled by a temperature regulator (not shown) so as to be a predetermined temperature. The electroless plating solution 9 can leak and fall from a gap (slit) through which the roll sheet 3 of the electroless plating tank 8 is passed. Therefore, a receiving tank 10 for receiving the leaked electroless plating solution 9 is installed below the electroless plating tank 8, and the electroless plating solution 9 received in the receiving tank 10 is supplied with the circulation pump 11 and the filter 12. Then, it is recirculated to the electroless plating tank 8 again.

  The roll sheet 3 that has exited the electroless plating tank 8 is washed away with an unnecessary electroless plating solution 9 in a water washing tank 13, drained and dried in a drier 14, wound up again, and rolled up to form a roll-shaped electromagnetic shielding material roll. It becomes the body 15.

Moreover, the electromagnetic wave shielding material manufacturing apparatus 1A shown in FIG. 2 is an apparatus that performs electrolytic plating after electroless plating. In this electromagnetic shielding material manufacturing apparatus 1A, since the structure from the raw fabric roll 2 to the electroless plating tank 8 is the same as that of the electromagnetic shielding material manufacturing apparatus 1 shown in FIG. 2 indicates that the left side and the right side of the apparatus are divided into two upper and lower stages due to dimensional limitations in the drawing, and the roll sheet 3 includes the upper right end of the solid line portion and the lower stage. Please understand that it is directly connected to the left end of the solid line.
The roll sheet 3 that has exited the electroless plating tank 8 is transferred to the electrolytic plating tank 16 after washing away unnecessary electroless plating solution 9 in the water washing tank 7.

  In the electrolytic plating tank 16, electrolytic plating is performed between the feeding rolls 17, 17 serving as the cathode and the positive electrode plates 18, 18 serving as the anode through the electrolytic plating solution 19, and is formed on the developed silver mesh pattern of the roll sheet 3. An electrolytic plating layer is deposited on the electroless plating layer. The temperature of the electrolytic plating solution 19 is controlled by a temperature regulator (not shown) so as to be a predetermined temperature. The power supply rolls 17 and 17 are provided at the entrance and exit for the roll sheet 3 to enter and exit the electrolytic plating tank 16, and the electrolytic plating solution 19 leaks from the gap between the power supply rolls 17 and 17 of the electrolytic plating tank 16. Can fall. Therefore, a receiving tank 10 that receives the leaked electrolytic plating solution 19 is installed below the electrolytic plating tank 16, and the electrolytic plating solution 19 received by the receiving tank 10 passes through the circulation pump 11 and the filter 12 again. It is configured to recirculate to the electrolytic plating tank 16.

  The roll sheet 3 exiting the electrolytic plating tank 16 is washed away with unnecessary electrolytic plating solution 19 in the water washing tank 13, drained and dried by a dryer 14, wound up again, and rolled up to form a roll-shaped electromagnetic shielding material roll 15. It becomes.

  In the prior art, as in the roll sheet 50 shown in FIG. 5, mesh patterns 52, 52,... .. Are used, and power supply layers 55 are provided on both outer sides in the width direction of the respective shield frames 53. The prior art in the case of performing electroplating is based on an intermittent method in which electroplating is intermittently performed by step-feeding the roll sheet 3 with transfer rolls 4, 4, 4,. For this reason, in the prior art, the supply and transfer of the roll sheet 3 are stopped for a certain period of time during each plating step in which each mesh pattern 52 is electroplated, so that productivity is limited to a low level. It was.

  Therefore, in the present invention, the roll sheet 3 that has not been exposed / developed is continuously fed out from the original fabric roll 2 and subjected to exposure / development to generate a developed silver mesh pattern, and then the transfer rolls 4, 4,. It transfers to the electroless-plating tank 8 by feeding, and performs electroless plating continuously without interruption.

In the present invention, electrolytic plating can be further performed following electroless plating (see FIG. 2 and the description thereof). When performing electroplating, in order to supply power to the developed silver mesh pattern, it is necessary to provide a power supply layer for electroplating on the transparent substrate. This power feeding layer can be provided in advance on a transparent base material used as the raw fabric roll 2, but this causes a problem that the previous step is complicated. For this reason, it is preferable to provide a power feeding layer between a series of steps by exposure / development by the exposure device 5 and the developing device 6 and / or electroless plating in the electroless plating tank 8.
Here, in the present invention, when electrolytic plating is performed in the electrolytic plating tank 16, there is a case where a feeding layer for electrolytic plating (hereinafter referred to as “continuous feeding layer”) provided continuously in the longitudinal direction on the roll sheet 3. ) To supply power to the developed silver mesh pattern.

  When further electrolytic plating is performed subsequent to electroless plating, mesh patterns 22, 22,... Are formed at a constant interval 24 on at least one surface of a long transparent base material 21, as in the roll sheet 20 shown in FIG. Are arranged around the mesh pattern 22, and the continuous feed layers 25, 25 having a constant width continuous in the longitudinal direction of the transparent substrate 21 are in contact with both outer sides in the width direction of the shield frame 23. The provided material is transferred to the electroplating tank 16 as the roll sheet 3 of FIG. As shown in FIG. 3, the size and shape of the mesh pattern 22 when the mesh patterns 22, 22,... Are provided with a constant interval 24 are not particularly limited. For example, the screen size of the display is preferable.

  Or the metal mesh pattern 32 provided in the at least one surface of the elongate transparent base material 31 like the roll sheet 30 shown in FIG. 2 is provided as a roll sheet 3 of FIG. 2 in which continuous feed layers 33, 33 having a constant width continuous in the longitudinal direction of the transparent substrate 31 are provided in contact with both outer sides in the width direction of the metal mesh pattern 32. 16 to be transferred. The form shown in FIG. 4 is suitable as an electromagnetic shielding material roll body supplied in a continuous roll sheet state for covering a wide area such as a window glass of a large building.

  The mesh patterns 22 and 32 provided on the roll sheet 3 before being transferred to the electrolytic plating tank 16 generate a developed silver mesh pattern by exposure and development using the exposure device 5 and the developing device 6 by a photographic method, An electroless plating layer is deposited in the electroless plating tank 8. If the continuous power feeding layers 25 and 33 and / or the shield frame 23 are necessary on the transparent base materials 21 and 31, these can also be generated on the transparent base material by the same method and process as the mesh patterns 22 and 32. In the present invention, the roll winding width of the mesh patterns 22 and 32 is 600 mm to 1600 mm.

  The continuous power supply layers 25 and 33 are in contact with the power supply rolls 17 and 17 serving as cathodes before and after the place where the roll sheet 3 is introduced into the electrolytic plating tank 16. As a result, during electrolytic plating, an electrolytic current is supplied to the mesh patterns 22 and 32 through the continuous power supply layers 25 and 33, and the electroless plating layer formed on the developed silver mesh pattern is subjected to electrolytic plating. A plating layer is deposited. As a result, the mesh patterns 22 and 32 in the electromagnetic wave shielding material roll 15 are obtained by forming a plating layer composed of an electroless plating layer and an electrolytic plating layer on the developed silver mesh pattern. The width of the continuous power feeding layers 25 and 33 is preferably 15 to 80 mm.

(Transparent substrate)
As the transparent base materials 21 and 31 used in the present invention, those having transparency in the visible region and generally having a total light transmittance of 90% or more are preferable. Especially, the resin film which has flexibility is used suitably at the point which is easy to handle. Specific examples of the transparent resin film used for the transparent substrates 21 and 31 include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylic resins, epoxy resins, fluorine resins, silicone resins, and polycarbonate resins. Single layer film having a thickness of 50 to 300 μm made of diacetate resin, triacetate resin, polyarylate resin, polyvinyl chloride, polysulfone resin, polyether sulfone resin, polyimide resin, polyamide resin, polyolefin resin, cyclic polyolefin resin, etc. A multi-layer composite film made of the transparent resin can be used.

(Metal mesh pattern production method)
The method for producing a conductive metal mesh applicable to the present invention is to form a conductive metal pattern by forming a fine line pattern with metallic silver developed by a photographic method and then physically developing and / or plating the metallic silver. This is due to the exposure development method.
In the exposure development method based on this photographic method applicable to the present invention, as described above, (a) developed silver appears in an exposed portion that is not covered with the exposure mask, that is, opposite to the exposure mask. A so-called negative-type exposure development method in which developed silver appears in the form, and (b) so-called developed silver appears in the same form as the exposure mask, that is, the phenomenon silver appears in the portion that is covered with the exposure mask and not exposed. There are two types of positive exposure development methods. Either (a) a negative exposure / development method or (b) a positive exposure / development method can be applied to the present invention.

  Hereinafter, a method for producing a metal mesh pattern using a positive exposure / development method (DTR method) and an electrolytic plating method will be described. In the case of the DTR method, it is preferable that a physical development nucleus layer is provided in advance on the transparent substrate surface. As the physical development nuclei, fine particles (having a particle size of about 1 to several tens of nm) made of heavy metals or sulfides thereof are used. Examples thereof include colloids such as gold and silver, metal sulfides obtained by mixing water-soluble salts such as palladium and zinc and sulfides, and the like. The fine particle layer of these physical development nuclei can be provided on the transparent substrate by a vacuum deposition method, a cathode sputtering method, a coating method or the like. From the viewpoint of production efficiency, a coating method is preferably used. The content of physical development nuclei in the physical development nuclei layer is suitably about 0.1 to 10 mg per square meter in solid content.

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

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

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

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

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

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

  Halation at any position on the transparent substrate on which the physical development nucleus layer is provided, for example, an adhesive layer, an intermediate layer, a physical development nucleus layer or a silver halide emulsion layer, a protective layer, or a backing layer provided with a support interposed therebetween Or a dye or pigment for preventing irradiation may be contained.

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

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

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

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

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

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

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

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

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

As described above, there are fine line patterns in which, for example, fine lines having a line width of about 10 to 100 μm are provided in a grid pattern in the vertical and horizontal directions. If the narrow line width is reduced and the interval between the gratings is increased, the translucency increases. However, the conductivity decreases, and conversely, if the fine line width is increased to reduce the lattice spacing, the translucency is decreased and the conductivity is increased. The silver image formed by physical development of an arbitrary fine line pattern formed on the transparent substrate according to the present invention has a translucency with a total light transmittance of 50% or more and a conductivity with a surface resistivity of 10 ohms / □ or less simultaneously. It is difficult to satisfy. Specifically, the silver image by this physical development has a conductivity of a surface resistivity of 50 ohms / square or less, preferably 20 ohms / square or less, but a pattern with a fine line width of 50 μm or less, for example, a fine line width of 20 μm. When the total light transmittance is 50% or more, the surface resistivity becomes several hundred ohms / square to 1000 ohms / square or more. However, the silver image by the physical development itself forms a silver image because the metallic silver particles forming the silver image obtained after the development processing are extremely small and the amount of the hydrophilic binder present in the silver image is extremely small. Since the silver image is formed in a state close to the close-packed state and the electroconductive property is obtained, the fine silver wire pattern can be obtained by plating with a metal such as copper or nickel, especially by electroplating. Is a transparent thin line pattern having a total light transmittance of 50% or more, preferably 60% or more, when the thickness is 0.5 to 15 μm and the line width is 10 to 50 μm. The conductivity of □ or less, preferably 7 ohm / □ or less can be maintained.
In order to improve the total light transmittance of the metal mesh, it is necessary to sufficiently increase the area of the light transmission portion between the fine lines with respect to the area of the region where the fine lines are provided. For this reason, it is preferable that the space | interval of a thin wire | line is 100-900 micrometers, More preferably, it is 150-700 micrometers.

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

  The thin line pattern of physically developed silver can be plated by any of electroless plating, electrolytic plating, or a combination of both, but when the roll width of the transparent substrate is 600 mm to 1600 mm, both ends of the roll The distance between the power supply rolls disposed in the battery becomes long, and the current-carrying resistance through the mesh pattern becomes excessive. For this reason, it becomes difficult to perform electrolytic plating uniformly on the developed silver constituting the mesh pattern.

  In order to solve this, in the present invention, an electroless plating layer is first laminated on a developed silver mesh pattern produced by a photographic method, and an electrolytic plating layer is further laminated as necessary. As the electroless plating, electroless copper plating or electroless nickel plating is preferably used. The type of electroless plating tank 8 (see FIGS. 1 and 2) to be used may be either a vertical type or a horizontal type, but a predetermined plating residence time required for the electroless plating reaction is ensured. The length of the electroless plating tank is determined according to the transfer speed of the roll sheet 3 so that it can be done.

  In the present invention, the metal plating method can be performed by a known method, and the electroless plating method can be a known electroless copper plating or electroless nickel plating. In addition, as the electrolytic plating method, conventionally known methods such as copper, nickel, silver, gold, solder, or a copper / nickel multilayer or composite system can be used, and these are described in “Surface Treatment Technology Overview; Reference can be made to Document Center, December 21, 1987, first edition, pages 281-242.

It is preferable to use copper and / or nickel for reasons such as easy plating, excellent electrical conductivity, plating on a thick film, and low cost. As an example of electrolytic plating, the transparent base material on which the above-described physically developed silver is formed is immersed in a bath mainly composed of copper sulfate, sulfuric acid and the like, and a current density of 1 to 20 amperes / percent at 10 to 40 ° C. Plating can be performed by energizing at dm ² . The electrolytic plating tank 16 (see FIG. 2) to be used may be either a vertical type or a horizontal type, but the electrolytic plating is performed according to the transfer speed of the roll sheet 3 so that a predetermined plating residence time can be secured. Determine the length of the tank.

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

  According to the present invention, it is possible to provide an electromagnetic wave shielding material that is supplied in a roll shape to a production process of an optical filter of a PDP, etc., which has a stable partial performance with little variation in the performance of the electromagnetic wave shield, and a method for producing the same. it can. In addition, it is possible to manufacture an electromagnetic shielding material that is wide and is supplied in a continuous roll sheet state to cover a large area such as a window glass of a large building, which cannot be handled by a conventional manufacturing method.

In this invention, it is the schematic which shows an example of the apparatus which performs electroless plating following an exposure and image development process with a roll to roll. In this invention, it is the schematic which shows an example of the apparatus which performs electroless plating and electrolytic plating following a light exposure / development process with a roll to roll. It is a fragmentary top view which shows an example of arrangement | positioning of the mesh pattern in the electromagnetic wave shielding material roll body of this invention, and a continuous electric power feeding layer. It is a fragmentary top view which shows the other example of arrangement | positioning of the mesh pattern in the electromagnetic wave shielding material roll body of this invention, and a continuous electric power feeding layer. It is a fragmentary top view which shows an example of arrangement | positioning of the mesh pattern and electric power feeding layer in the conventional electromagnetic wave shielding material for displays.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A ... Electromagnetic-shielding material manufacturing apparatus, 2 ... Original fabric roll, 3 ... Roll sheet, 4 ... Transfer roll, 5 ... Exposure apparatus, 6 ... Developing apparatus, 7 ... Water washing tank, 8 ... Electroless plating tank, 9 DESCRIPTION OF SYMBOLS ... Electroless plating solution, 10 ... Receiving tank, 11 ... Circulation pump, 12 ... Filter, 13 ... Water washing tank, 14 ... Dryer, 15 ... Electromagnetic shielding material roll body, 16 ... Electrolytic plating tank, 17 ... Feed roll, 18 ... Positive electrode plate, 19 ... Electrolytic plating solution, 20, 30 ... Roll sheet according to the present invention, 21, 31 ... Transparent substrate, 22, 32 ... Mesh pattern, 23 ... Shield frame, 24 ... Spacing, 25, 33 ... Continuous feeding layer.

Claims (11)

An electromagnetic shielding material roll body provided with a metal mesh pattern on at least one surface of a long transparent base material and supplied in a roll state,
The metal mesh pattern has a developed silver mesh pattern generated by a photographic method and an electroless plating layer laminated thereon, and the roll width of the metal mesh pattern is 600 to 1600 mm. An electromagnetic shielding material roll body characterized by the above.   The electromagnetic wave shielding material roll according to claim 1, wherein the electroless plating layer is an electroless copper plating layer or an electroless nickel plating layer.   The electromagnetic wave shielding material roll according to claim 1, wherein an electrolytic plating layer is further laminated on the electroless plating layer.   The electromagnetic wave shielding material roll according to any one of claims 1 to 3, wherein the developed silver mesh pattern is generated by a negative developing method in which developed silver is developed in an exposed portion.   The electromagnetic wave shielding material roll according to any one of claims 1 to 3, wherein the developed silver mesh pattern is generated by a positive developing method in which developed silver is developed in a portion not exposed to light. A metal mesh pattern is provided on at least one surface of a long transparent substrate, and is a method of manufacturing an electromagnetic shielding material roll body supplied in a roll state,
The transparent base material is continuously drawn out, and a developed silver mesh pattern having a roll winding width of 600 to 1600 mm is generated on at least one surface of the transparent base material by a photographic method, and subsequently the developed silver mesh pattern A method for producing an electromagnetic shielding material roll body, comprising forming an electroless plating layer on the substrate and then winding it again to form a roll body.   The method for producing an electromagnetic shielding material roll according to claim 6, wherein after the development silver mesh pattern is generated, the electroless plating is performed while the surface of the transparent substrate is kept wet. .   The said electroless plating is electroless copper plating or electroless nickel plating, The manufacturing method of the electromagnetic wave shielding material roll body of Claim 6 or 7 characterized by the above-mentioned.   The method for producing an electromagnetic wave shielding material roll according to any one of claims 6 to 8, wherein after the electroless plating, an electroplating layer is further laminated on the electroless plating layer.   10. The method for producing an electromagnetic wave shielding material roll according to claim 6, wherein the development silver mesh pattern is generated by a negative development method in which developed silver appears in an exposed portion.   The method for producing an electromagnetic wave shielding material roll according to any one of claims 6 to 9, wherein the development silver mesh pattern is generated by a positive development method in which developed silver appears in a portion not exposed to light.

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