JP2010093239A - Method for manufacturing board with metal particle laminated thereon like mesh and transparent conductive board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a board with metal particle laminated thereon like a mesh, which can manufacture the board with the metal particle laminated thereon like the mesh with excellent transparency and moire resistance at high productivity by a continuous application process, to provide the board with the metal particle laminated thereon like the mesh, and to provide a transparent conductive board using the board with the metal particle laminated thereon like the mesh. <P>SOLUTION: The method for manufacturing the board with the metal particle laminated thereon like the mesh, laminates a metal particle layer on a substrate like the mesh by applying a metal particle solution onto at least one surface of the substrate. In the method, after applying the metal particle solution, the substrate is placed under an airflow in a direction of within ±45° when defining a direction parallel to a substrate surface as 0° and the mesh like metal particle layer is formed by setting a wind velocity of the airflow to 1.0 to 10 m/sec to manufacture the board with the metal particle laminated thereon like the mesh with total light transmittance of 50% or more. The board with the metal particle laminated thereon like the mesh is manufactured by the manufacturing method and the transparent conductive board uses the board with the metal particle laminated thereon like the mesh. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a reticulated metal fine particle laminate substrate having excellent transparency and moiré resistance, a reticulated metal fine particle laminate substrate, and a transparent conductive substrate using the same.

  Transparent conductive substrates are used in various devices as circuit materials, and are used as electromagnetic shielding substrates and solar cell applications.

  The electromagnetic shielding substrate is used for the purpose of suppressing various electromagnetic waves radiated from electronic devices such as home appliances, mobile phones, personal computers, and televisions. Among digital home appliances that are growing rapidly, strong electromagnetic waves are emitted from flat panel displays such as plasma display panels and liquid crystal televisions, and there is concern about the effects on the human body. Since these displays observe images at a relatively short distance and in some cases for a long time, an electromagnetic wave shielding substrate that suppresses these electromagnetic waves is required and has been intensively studied.

  In general, a transparent conductive substrate is used for an electromagnetic wave shielding substrate used in a display panel, and various methods are employed for manufacturing a conductive substrate for an electromagnetic wave shielding substrate that is currently used. Yes. For example, a copper foil is bonded to a polyester film, a regular mesh shape is patterned by photolithography, and the copper foil is etched into a mesh shape, thereby creating a mesh-like conductive film whose conductive portion is copper. (See Patent Document 1).

  However, the above-described conventional technique has the following problems.

  The method of etching a copper foil described in Patent Document 1 is an excellent method for obtaining a highly accurate mesh shape. However, in the process of laminating a copper foil, a photolithography process, an etching process, etc. In particular, the yield was poor, and there was a problem that product loss in each process was likely to occur. In particular, there are many environmental issues such as the generation of harmful waste liquid in the etching process. Furthermore, if copper foil is used as a material and then the copper foil is etched to increase permeability, it is necessary to dissolve a large part of the copper foil by etching to make a waste liquid, which is an aspect of material recycling. But there were many issues.

  Moreover, since the lattice-like copper foil layer of this board | substrate has a regular structure, it also had the problem that a moire phenomenon generate | occur | produces.

  Here, the moire phenomenon is “a striped pattern generated when overlapping regularly distributed points or lines geometrically”, and according to Kojien, “a point or line is geometrically Stripe pattern that occurs when superposed distributions are superposed. This is likely to occur when a halftone is reproduced using a halftone print as a manuscript. " Pattern occurs. This is because, when a regular pattern such as a grid pattern is provided on the electromagnetic shielding substrate provided on the front surface of the display, it interacts with a regular grid-shaped partition wall that partitions the pixels of each RGB color on the back side of the display. This moire phenomenon occurs. Further, when a regular pattern such as a grid pattern is provided on the electromagnetic wave shield substrate, there is a problem that the moire phenomenon is more likely to occur as the line width of the grid increases.

  Then, in view of the background of such a prior art, when a reticulated metal fine particle laminated substrate was prepared using a metal fine particle solution, for example, CE103-7 manufactured by Cima NanoTech, a reticulated metal excellent in transparency and moire resistance. A method for producing a reticulated metal fine particle laminated substrate and a reticulated metal fine particle laminated substrate capable of producing a fine particle laminated substrate with high productivity were obtained.

JP 2001-210988 A

  However, when the metal fine particle solution described above is used, it takes a long time to form the network metal fine particle layer, and therefore it is difficult to apply it to a continuous coating process. Also, even if it can be applied to a continuous coating process, it takes a long time to form the mesh metal fine particle layer, which increases costs and may cause problems in terms of productivity. There is.

  In view of the background of the prior art, the present invention is a mesh metal fine particle that can be applied to a process of producing a mesh metal fine particle laminated substrate excellent in transparency and moire resistance with high productivity and continuously coating it. It is an object of the present invention to provide a method for producing a laminated substrate, a reticulated metal fine particle laminated substrate, and a transparent conductive substrate using the same.

The present invention employs the following means in order to solve such problems.
1) A method for producing a reticulated metal fine particle laminated substrate in which a metal fine particle layer is laminated on a substrate in a reticulated manner by applying a metal fine particle solution on at least one side of the substrate,
After coating, the substrate is placed in an airflow in a direction within ± 45 degrees with the direction parallel to the substrate surface being 0 degree, and the air velocity of the airflow is 1.0 m / second or more and 10 m / second or less. A method for producing a reticulated metal fine particle multilayer substrate having a total light transmittance of 50% or more.
2) The method for producing a reticulated metal fine particle laminated substrate as described in 1) above, wherein the temperature during application of the metal fine particle solution to the substrate in an air stream is 10 ° C. or higher and 50 ° C. or lower.
3) A mesh shape as described in 1) or 2) above, wherein the time for placing the substrate under an air flow in a direction within ± 45 degrees with the direction parallel to the substrate surface being 0 degrees is 30 seconds or less. Manufacturing method of metal fine particle laminated substrate.
4) The net-like metal according to any one of 1) to 3) above, wherein the variation in the wind speed of the airflow in the width direction of the substrate is within 2 m / second in difference between the maximum value and the minimum value of the wind speed. Manufacturing method of fine particle laminated substrate.
5) The metal fine particle layer of the network metal fine particle multilayer substrate produced by the method according to any one of 1) to 4) is treated with an organic solvent after heat treatment, and treated with an acid. A method for producing a transparent conductive substrate.
6) A transparent conductive substrate obtainable by the production method described in 5) above.
7) The transparent conductive substrate according to 6) above, having a surface specific resistance of 30Ω / □ or less.
8) A plasma display panel, wherein the transparent conductive substrate according to 6) or 7) is provided on the panel surface as an electromagnetic shielding substrate.

  According to the present invention, after the metal fine particle solution is applied, the substrate is placed under an airflow in a direction within ± 45 degrees with the direction parallel to the substrate surface being 0 degree, and the airflow velocity is 1.0 m / second or more. By forming a mesh metal fine particle layer at a speed of 10 m / second or less, it is applied to a process for continuously coating a mesh metal fine particle multilayer substrate having both excellent transparency and moire resistance and excellent productivity. be able to. Moreover, according to the manufacturing method of the more preferable aspect of this invention, the effect which suppresses further nonuniformity, such as the film thickness of a metal fine particle layer, can be acquired. The transparent conductive substrate using the network metal fine particle multilayer substrate of the present invention has transparency and a high level of conductivity, and also has excellent moire resistance. For example, flat panels such as plasma display panels and liquid crystal televisions It can be suitably used for a display.

It is a top view which shows an example of the network structure in the network metal fine particle laminated substrate of this invention. It is the schematic which shows typically the method to measure the airflow direction on a board | substrate. It is the schematic shown typically explaining the method to measure the wind speed of the airflow on a board | substrate. The figure which looked at FIG. 3 from the A direction in the wind speed measuring method.

  The present invention is excellent in both of the above-mentioned problems, that is, transparency and moire resistance, and is a process for continuously applying a network metal fine particle multilayer substrate, which can be manufactured with high productivity. When manufacturing a laminated substrate by applying a metal fine particle solution to at least one surface of the substrate and studying the manufacturing method, a short-formation method using a forming method that satisfies a specific condition is applied after the metal fine particle solution is applied to the substrate. As a result of laminating with time, it has been found that the above problems can be solved at once.

  In the present invention, as a method for forming the network metal fine particle layer in a short time, a substrate having excellent transparency can be produced in a short time for the first time by forming it with a forming method that satisfies a specific condition. It was made.

  In the present invention, after the metal fine particle solution is applied, the substrate is placed under an airflow in a direction within ± 45 degrees with the direction parallel to the substrate surface being 0 degree, but in the present invention, the airflow angle is Measurement was performed as follows. That is, in the manufacturing process of laminating a metal fine particle layer on a substrate, as shown in FIG. 2, a bar with a 2 cm thread at the tip was placed parallel to the substrate at a location of 2 cm on the substrate to be laminated.

  If the thread attached to the tip of the rod is fluttering parallel to the substrate surface, the airflow angle is 0 degree, if it is vertically fluttering, the airflow angle is 90 degrees, and if it is vertically fluttering, the airflow angle is -90 degrees. . It is important that the airflow angle is 0 ° or more and within ± 45 °, more preferably 0 ° or more and within ± 30 °, still more preferably 0 ° or more and within ± 15 °, and particularly preferably ± Within 5 degrees. If the airflow angle deviates from ± 45 degrees, the structure connected in a mesh shape will be removed when the wind speed of the airflow is increased. Therefore, when a transparent conductive substrate is formed using a mesh metal fine particle multilayer substrate. There may be a problem in terms of conductivity. By setting the airflow angle between 0 ° and ± 45 ° and controlling the air velocity of the airflow as described later, a network-like metal fine particle layer can be formed on the substrate in a very short time of 30 seconds or less. Is possible. In addition, if the time for forming the mesh-like metal fine particle layer on the substrate exceeds 30 seconds, it may not be applicable to a continuous coating process, which may cause problems in terms of productivity and cost. . By forming a network-like fine metal particle layer on a substrate in a very short time of 30 seconds or less, it can be applied to a continuous coating process, and productivity can be improved.

  In addition, when applied to a process of continuously applying a network metal fine particle laminated substrate, the direction of the airflow is preferably parallel to the longitudinal direction of the substrate. As long as it is parallel to the longitudinal direction, there is no particular problem even if the airflow is in the same direction as the flow direction of the substrate, or even in the direction opposite to the flow direction of the substrate. In the case of an airflow from the width direction of the substrate, there may be a problem that unevenness occurs in the coating film when a mesh-like metal fine particle laminated substrate is used.

  In the present invention, when the substrate is placed under an airflow within ± 45 degrees with the direction parallel to the substrate surface being 0 degree, the time when the substrate is placed under the airflow is always within ± 45 degrees. This means placing the substrate underneath. While the substrate is placed under an air current, the coating film (network metal fine particle layer) may be uneven if there is a slight air flow that deviates from the range of ± 45 ° with the direction parallel to the substrate surface being 0 °. Will occur. Therefore, when the airflow is turbulent, while the substrate is placed under the airflow, there are cases where the airflow is within ± 45 degrees with the direction parallel to the substrate surface being 0 degrees and where the airflow is deviating from that. It will change frequently, and a nonuniformity will arise in a coating film (mesh-like metal fine particle layer). More preferably, the airflow angle is always kept constant.

  In the present invention, after the metal fine particle solution is applied, the substrate is placed in an air flow in a direction within ± 45 degrees, with the direction parallel to the substrate surface being 0 degree, and the air velocity at this time is 1.0 m. It is the feature that it makes it to 10 m / second or more / second. And in this invention, the measurement of the wind speed of airflow is measured as follows using an anemometer. That is, in the manufacturing process of laminating a network metal fine particle layer on a substrate, an anemometer is used to measure the angle measured by the air flow angle measurement method described above on 1 cm above the surface of the substrate on which the metal fine particle solution is applied. Measure the speed of the airflow only. At a certain point on the substrate, the wind speed when the probe is placed to receive the wind speed of the airflow at the angle measured above is measured for 30 seconds in a stationary state (see FIGS. 3 and 4). The maximum value measured for 30 seconds is taken as the wind speed of the airflow.

  It is important that the wind speed of the air current is 1.0 m / second or more and 10 m / second or less, preferably 2.0 m / second or more and 8.0 m / second or less, more preferably 4.0 m / second or more and 8 or less. 0.0 m / sec or less, particularly preferably 6.0 m / sec or more and 7.5 m / sec or less. When the air velocity of the air flow is higher than 10 m / sec, the structure connected in a mesh shape is removed regardless of the air flow angle. For this reason, the conductivity when a transparent conductive substrate is formed using a mesh metal fine particle multilayer substrate is used. There may be problems in terms of sex. In addition, although it is possible to obtain a reticulated metal fine particle substrate if it is less than 1.0 m / sec, it takes a long time to form when considering application to a continuous process, which increases productivity such as cost increase. Problems can occur. By controlling the air flow angle between 0 ° and ± 45 ° and the air velocity of the air flow between 1.0 m / sec and 10 m / sec, the mesh-like metal is formed on the substrate in a very short time of 30 seconds or less. It is possible to form a fine particle layer.

  It is important for the air velocity of the air flow that there is no variation in the width direction of the substrate in order to obtain a network metal fine particle laminated substrate with stable characteristics, and the variation in the air velocity of the air flow in the width direction of the substrate is the wind velocity in the width direction. The difference between the maximum value and the minimum value is preferably within 2 m / second, more preferably within 1.5 m / second, and even more preferably within 1.0 m / second. If the variation in the wind speed of the airflow in the width direction of the substrate is within 2 m / sec between the maximum value and the minimum value of the wind speed, the variation in transparency can be suppressed, and the difference between the maximum value and the minimum value of the wind speed can be suppressed. Is larger than 2 m / sec, the time required for forming the mesh metal fine particle multilayer substrate varies in the width direction of the substrate, and when the mesh metal fine particle multilayer substrate is formed, the total light transmittance in the width direction of the substrate is Variations may occur and unevenness of the coating film may occur. For this reason, when a transparent conductive substrate is formed using the network metal fine particle multilayer substrate, there may be a problem in terms of transparency.

  Although the temperature of this airflow is not specifically limited, Preferably it is 10 to 50 degreeC, More preferably, it is 15 to 40 degreeC, More preferably, it is 15 to 30 degreeC. That is, when the temperature of the airflow is less than 10 ° C. or greater than 50 ° C., the total light transmittance is lowered, and there may be a problem in terms of transparency of the network metal fine particle laminated substrate. In addition, the structure connected in a mesh shape may be removed, which may cause a problem in terms of conductivity when the mesh-like metal fine particle laminated substrate is used as a transparent conductive substrate. As will be described later, it is important that the temperature on the substrate satisfies the condition of 10 ° C. or more and 50 ° C. or less, and it is preferable to adjust the temperature of the airflow itself so as to satisfy this condition.

  In the present invention, when applying the metal fine particle solution to at least one surface of the substrate, at least the temperature between the start of application of the metal fine particle solution and the completion of application, and the airflow in a direction within ± 45 degrees from the parallel to the substrate surface after application The temperature during the placement of the substrate underneath (that is, the temperature during the placement of the substrate under the airflow from the application of the metal fine particle solution) is not particularly limited, and can be appropriately selected depending on the solvent in the metal fine particle solution. However, it is preferable that the temperature on the substrate is controlled so as to satisfy the condition of 10 ° C. or more and 50 ° C. or less. The temperature on the substrate is more preferably 15 ° C. or higher and 40 ° C. or lower, and further preferably 15 ° C. or higher and 30 ° C. or lower. That is, when the solvent of the applied metal fine particle solution is removed at a high temperature, for example, at a temperature higher than 50 ° C., the solvent is rapidly removed, so that the metal fine particle layer is laminated in a network. In some cases, a problem occurs in the process, the total light transmittance is lowered, and there is a problem in terms of transparency of the network metal fine particle multilayer substrate. Further, when the temperature of the airflow exceeds 50 ° C., the structure connected to the network shape is removed by the rapid removal of the solvent. For this reason, when a transparent conductive substrate is formed using the network metal fine particle multilayer substrate There may be a problem in terms of conductivity. In addition, when the temperature on the substrate is lower than 10 ° C., the removal rate of the solvent is delayed, and it may take a long time to form the reticulated metal fine particle layer, which may not be applicable to a continuous coating process. Problems can arise in terms of productivity and cost. Therefore, it is preferable that the temperature during the placement of the substrate under the airflow after the application of the metal fine particle solution is 10 ° C. or more and 50 ° C. or less as the temperature on the substrate. It is preferable to adjust.

  The temperature on the substrate is measured using a thermometer as follows. That is, in the manufacturing process of laminating the mesh metal fine particle layer on the substrate, the temperature 1 cm above the center of the surface on which the metal fine particle solution is applied is measured using a thermometer.

  Moreover, although the humidity of this airflow itself is not specifically limited, Preferably it is 10-70% RH, More preferably, it is 20-60% RH, Most preferably, it is 30-50% RH. That is, if the humidity of the airflow is less than 1%, the total light transmittance is lowered, and there may be a problem in terms of transparency of the network metal fine particle multilayer substrate. Further, when the humidity on the substrate is higher than 85% RH, the structure connected in a mesh shape is removed, and therefore, in terms of conductivity when a transparent conductive substrate is formed using a mesh metal fine particle laminated substrate. Problems may arise. As will be described later, it is important that the humidity on the substrate satisfies the condition of 1 to 85% RH, and it is preferable to adjust the humidity of the airflow itself so as to satisfy this condition.

  In the method for producing a reticulated metal fine particle laminated substrate of the present invention, when applying the metal fine particle solution to at least one surface of the substrate, at least from the start of application of the metal fine particle solution to the completion of application, and further parallel to the substrate surface after application It is preferable to control the humidity on the substrate to an atmosphere satisfying the condition of 1 to 85% RH while the substrate is placed in an airflow in a direction within ± 45 degrees with the direction being 0 degrees. The humidity on the substrate is preferably 10 to 70% RH, more preferably 20 to 60% RH, and particularly preferably 30 to 50% RH. That is, when the humidity on the substrate is less than 1%, the total light transmittance is lowered, and there may be a problem in terms of transparency of the network metal fine particle laminated substrate. Further, when the humidity on the substrate is higher than 85% RH, the structure connected in a mesh shape is removed, and therefore, in terms of conductivity when a transparent conductive substrate is formed using a mesh metal fine particle laminated substrate. Problems may arise.

  The humidity on the substrate is measured using a hygrometer as follows. That is, in the manufacturing process of laminating a network metal fine particle layer on a substrate, the humidity above 1 cm from the center of the surface of the substrate on which the metal fine particle solution is applied is measured using a hygrometer.

  In the present invention, when a metal fine particle solution that self-assembles into a mesh shape is used as the metal fine particle solution, the substrate as described above at least from the start of application of the metal fine particle solution until the metal fine particle solution becomes a mesh shape. It is preferable to maintain the above humidity at specific conditions.

  In this airflow generation method, airflow can be generated by exhausting air on the substrate or supplying air onto the substrate.

  A method for exhausting or supplying air is not particularly limited, but it is important to create an air flow in a direction within ± 45 degrees by setting the direction parallel to the substrate surface as 0 degrees.

  For example, as a method of exhausting, exhaust can be performed using an exhaust fan or a draft. In addition, the air can be supplied by using a cooler or a dryer.

  After the metal fine particle solution is applied to the substrate, the time for placing the substrate under an air flow in a direction within ± 45 degrees with the direction parallel to the substrate surface being 0 degree is preferably 30 seconds or less, more preferably 25 seconds. Or less, more preferably 20 seconds or less. When the formation time is longer than 30 seconds, it is difficult to improve productivity because there is no production facility and the cost increases when considering application to a continuous coating process. In addition, after the metal fine particle solution is applied to the substrate, the time during which the substrate is placed in an air flow in a direction within ± 45 degrees with the direction parallel to the substrate surface being 0 degree is preferable, but the applied coating film has a mesh. In reality, it is difficult to make the time less than 5 seconds, and if it is about 5 seconds, it is practically sufficient.

  After applying the metal fine particle solution to the substrate, the time for placing the substrate in an air current is set to 30 seconds or less, and in order to suitably stack the metal fine particle layer in a network shape, after applying the metal fine particle solution to the substrate, the substrate This can be achieved by placing the substrate under an air flow in a direction within ± 45 ° with the direction parallel to the surface being 0 °, and further setting the air velocity of the air flow to 1.0 m / second or more and 10 m / second or less.

  In the present invention, in the method for producing a reticulated metal fine particle laminated substrate, the surface wet tension of the surface of the substrate on which the metal fine particle solution is applied is preferably 45 mN / m or more and 73 mN / m or less, more preferably. It is 50-73 mN / m, More preferably, it is 55-73 mN / m. The surface wetting tension of 73 mN / m is a measurement limit value, and when it is less than 45 mN / m, when the metal fine particle solution is applied to the surface of the substrate, the metal fine particle solution does not form a network, A uniform coating film is formed, and there may be a problem that the transparency of the metal fine particle laminated substrate is inferior.

  In order to adjust the surface wetting tension of the surface of the substrate to which the metal fine particle solution is applied to 45 mN / m to 73 mN / m, known methods such as corona discharge treatment and plasma treatment can be used.

  In the present invention, the surface of the substrate is subjected to a hydrophilic treatment by coating with an anchor coat agent or a primer, and the substrate is provided with a hydrophilic treatment layer on at least one side. It is also a preferred embodiment that the surface wetting tension of the surface is set to 45 mN / m or more and 73 mN / m or less.

  The total light transmittance of the network metal fine particle multilayer substrate is preferably 50% or more, more preferably 65% or more, and further preferably 75% or more. If the total light transmittance is less than 50%, there may be a problem in terms of transparency of the network metal fine particle multilayer substrate. Although it is preferable that the total light transmittance of the network-like fine metal particle multilayer substrate is high, the upper limit is considered to be about 90% due to the balance with conductivity.

  Such total light transmittance is measured by the following measuring method. That is, in a normal state (23 ° C., relative humidity 65%), the mesh metal fine particle multilayer substrate was allowed to stand for 2 hours, and then measured using a fully automatic direct reading haze computer “HGM-2DP” manufactured by Suga Test Instruments Co., Ltd. The average value measured three times was taken as the total light transmittance of the network metal fine particle laminated substrate. If the total light transmittance is 50% or more, the transparency is good. In the case of a network-like metal fine particle laminated substrate in which a metal fine particle layer is laminated only on one side of the substrate, the measurement is performed by placing the substrate so that light enters from the side on which the metal fine particle layer is laminated.

  In the present invention, when a network structure is formed using a metal fine particle solution, for example, a solid content solution (metal colloid solution) containing particles composed of metal fine particles and an organic component such as a dispersant is used. The method of performing can be used suitably. As the solvent for the metal colloid solution, water and various organic solvents can be used.

  Examples of the method for adjusting the metal fine particles include a chemical method in which metal ions are reduced to metal atoms in a liquid layer and grown into nanoparticles through atomic clusters, or bulk metal is evaporated in an inert gas. Physics of trapping metal in fine particles with a cold trap, physics of breaking metal thin film by heating metal thin film obtained by vacuum deposition on polymer thin film, and dispersing metal nanoparticles in polymer in solid state Or the like can be used.

  In the present invention, a metal fine particle solution that self-assembles can be preferably used as the metal fine particle solution. Here, the “self-organizing metal fine particle solution” means a solution that spontaneously forms a network structure on a substrate when it is applied to one surface of the substrate and left to stand. As such a metal fine particle solution, for example, CE103-7 manufactured by Cima NanoTech can be used.

  The network structure in the network metal fine particle multilayer substrate of the present invention is preferably irregular. That is, when the reticulated metal fine particle multilayer substrate of the present invention is used by being bonded to a plasma display, it is possible to obtain a structure in which the moire phenomenon does not occur by making the reticulated structure irregular.

  Such an irregular network structure is specified by an observation image of a differential interference microscope, and the network structure is in a state where the shape and size of the void portion are irregular in its shape, that is, as an irregular state. Therefore, the portion of the mesh, that is, the shape of the linear portion is not a straight line, but the line thickness is not uniform, that is, an irregular state. An example of an irregular mesh-like structure is shown in FIG. 1, but is not limited to this.

  In the method for producing a reticulated metal fine particle laminated substrate of the present invention, when applying the metal fine particle solution to at least one surface of the substrate, the specific condition that the metal fine particle solution is laminated by a non-contact coating method that does not contact the substrate is set. It is important to meet. The non-contact coating method is not limited as long as it does not contact the substrate, and a known coating method such as a die coating method, an applicator method, a comma coating method, a spray method, a dipping method and the like can be used. When a contact type coating method that contacts the substrate is used when applying the metal fine particle solution, the portion in contact with the substrate is scratched, or the portion in contact with the substrate when the metal fine particle solution is applied Problems such as streaking may occur, which is not preferable.

  Further, when a contact-type coating method is used in which a surface of the substrate having a surface wetting tension of 45 mN / m or more is further subjected to a hydrophilic treatment, the substrate is contacted with the substrate. Is not preferred because it may be scraped off and not reticulated. For example, a mesh-like metal fine particle laminated substrate obtained by laminating a metal fine particle solution using a wire bar that is in contact with the substrate is a portion that does not come into contact with the wire bar along the wire pitch of the wire bar. The size of the gap portion of the network structure is different, the gap is larger at the contacted portion, and the gap is smaller at the non-contact portion. The different large and small voids are alternately arranged in a streak pattern, resulting in a regular pattern, which may cause a moire phenomenon. In addition, a network-like metal fine particle multilayer substrate laminated using a gravure coater that is a contact type for contacting the substrate with the metal fine particle solution is in contact with the substrate so that the metal fine particle solution has a gravure plate shape. It may be applied and a gravure plate may be formed. Therefore, it is necessary to apply the metal fine particle solution by a non-contact application method that does not contact the substrate.

  The metal used for the metal fine particles in the present invention is not particularly limited, and examples thereof include platinum, gold, silver, copper, nickel, palladium, rhodium, ruthenium, bismuth, cobalt, iron, aluminum, zinc, and tin. A metal may be used by 1 type and may be used in combination of 2 or more type.

  The metal fine particle layer in the present invention is a layer composed of the metal fine particles as described above, and in addition to the metal fine particles, various other additives such as a dispersant, a surfactant, a protective resin, an antioxidant, It can contain an inorganic component such as a heat stabilizer, a weather stabilizer, an ultraviolet absorber, a pigment, a dye, organic or inorganic fine particles, a filler, an antistatic agent, and an organic component.

  In the present invention, by using a known method for enhancing the conductivity of the metal fine particle layer, such as heat treatment, the laminated metal fine particle layer is preferably used from the network metal fine particle laminated substrate by increasing the conductivity of the metal fine particle layer. A transparent conductive substrate can be obtained.

  And after apply | coating a metal fine particle solution to at least one surface of the board | substrate mentioned above, a board | substrate is set | placed on the airflow of the direction within ± 45 degree | times after setting the direction parallel to a substrate surface to 0 degree | times, and also the wind speed of this airflow is 1. The reticulated metal fine particle multilayer substrate obtained by the production method characterized in that the flow rate is 0 m / second or more and 10 m / second or less, and the metal fine particle layer of the reticulated metal particle multilayer substrate is further treated with an organic solvent after heat treatment. And the transparent conductive substrate excellent in electroconductivity can be manufactured by processing with an acid.

  In the present invention, the temperature of the heat treatment of the metal fine particle layer of the network metal fine particle laminated substrate for obtaining the transparent conductive substrate is preferably 100 ° C. or higher and lower than 200 ° C., more preferably 130 ° C. or higher and 180 ° C. or lower, Preferably they are 140 degreeC or more and 160 degrees C or less. That is, if it is performed at a high temperature of 200 ° C. or higher for a long time, problems such as substrate deformation may occur, which is not preferable. Further, if the heat treatment temperature is less than 100 ° C., there may be a problem in terms of conductivity when a network-like fine metal particle multilayer substrate is used to form a transparent conductive substrate.

  The heat treatment time is preferably 30 seconds or longer and 3 minutes or shorter, more preferably 1 minute or longer and 3 minutes or shorter, and further preferably 2 minutes or longer and 3 minutes or shorter. That is, in the heat treatment for a time shorter than 30 seconds, there may be a problem in terms of conductivity when a mesh-like fine metal particle multilayer substrate is used to form a transparent conductive substrate. Further, if the heat treatment is performed for longer than 3 minutes, considering the application to a continuous process, a heat treatment step is required for a long time, which may cause problems in productivity such as cost increase.

  In addition, after the heat treatment is performed on the metal fine particle layer of the network metal fine particle laminated substrate as described above, the transparent fine conductive substrate can be obtained by increasing the conductivity by subsequently treating the metal fine particle layer of the network metal fine particle laminated substrate with an acid. It is preferable to obtain Since the method of treating with an acid can increase the conductivity of the metal fine particles under mild processing conditions, if such mild processing conditions are selected, a material having poor heat resistance and light resistance, such as a thermoplastic resin, can be used as a substrate. Even when used as, it can be suitably acid-treated. In addition, this method is preferable in terms of productivity because it does not require complicated apparatuses or processes.

  Such an acid is not particularly limited, and can be selected from various organic acids and inorganic acids. Examples of the organic acid include acetic acid, oxalic acid, propionic acid, lactic acid, and benzenesulfonic acid. Examples of inorganic acids include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and the like. These may be strong acids or weak acids. Preferred are acetic acid, hydrochloric acid, sulfuric acid, and aqueous solutions thereof, and more preferred are hydrochloric acid, sulfuric acid, and aqueous solutions thereof.

  A specific method of treating with such an acid is not particularly limited. For example, the substrate on which the metal fine particle layer is laminated in an acid or an acid solution is immersed, or an acid or an acid solution is immersed in the metal fine particle layer. For example, a method of applying to the top or applying a vapor of an acid or an acid solution to the silver fine particle layer is used.

  Further, as described above, the metal fine particle layer is treated with an organic solvent after the heat treatment of the metal fine particle layer of the network metal fine particle laminated substrate and before the metal fine particle layer of the mesh metal fine particle laminated substrate is treated with an acid. Therefore, a method of increasing the conductivity and obtaining a transparent conductive substrate is preferable. Thus, after the heat treatment of the metal fine particle layer of the reticulated metal fine particle laminated substrate and before the metal fine particle layer of the reticulated metal fine particle laminated substrate is treated with an acid, the treatment with an organic solvent provides better conductivity. It becomes easy to obtain a transparent conductive substrate having

  As a step of treating such a metal fine particle layer with an organic solvent, a method of laminating metal fine particles in a network form on a substrate to form a network-like metal fine particle laminated substrate, and then treating with an organic solvent has an effect of increasing conductivity. Since it is excellent and efficient in terms of productivity, it is preferably used. In addition, before or after the treatment with the organic solvent, another layer may be printed on or applied to the substrate on which the metal fine particle layer is laminated. Further, before or after the treatment with the organic solvent, the substrate on which the metal fine particle layer is laminated may be dried, heat-treated, or subjected to an ultraviolet irradiation treatment.

  When the metal fine particle layer is treated with an organic solvent, the treatment temperature of the organic solvent is sufficient at room temperature. When the treatment is performed at a high temperature, when a thermoplastic resin film is used as the substrate, the substrate may be whitened and transparency may be impaired, which is not preferable. Such treatment temperature is preferably 40 ° C. or less, more preferably 30 ° C. or less, and particularly preferably 25 ° C. or less.

  The method for treating the metal fine particle layer with an organic solvent is not particularly limited. For example, the substrate on which the metal fine particle layer is laminated in a solution of the organic solvent, the organic solvent is applied on the metal fine particle layer, A method of applying a vapor of the solvent to the metal fine particle layer is used. Among these, a method of immersing a substrate in which a metal fine particle layer is laminated in an organic solvent or coating an organic solvent on the metal fine particle layer is preferable because of its excellent conductivity improving effect.

  Examples of such organic solvents include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol, 3-methoxy-3-methyl-1-butanol, 1,3-butanediol, 3-methyl-1,3 Alcohols such as butanediol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and cyclopentanone, esters such as ethyl acetate and butyl acetate, alkanes such as hexane, heptane, decane and cyclohexane, N- Dipolar aprotic solvents such as methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, toluene, xylene, aniline, ethylene glycol butyl ether, ethylene glycol, ethyl ether, ethylene glyco Methyl ether, chloroform, and may be used a mixture of these solvents. Among these, it is preferable that ketones, esters, and toluene are contained because the effect of improving conductivity is excellent, and ketones are particularly preferable.

  Regarding the conductivity of the transparent conductive substrate in the present invention, the surface specific resistance is preferably 30 Ω / □ or less. The surface specific resistance is more preferably 20Ω / □ or less, further preferably 10Ω / □ or less, and particularly preferably 4Ω / □ or less. When the surface specific resistance is 30 Ω / □ or less, a load due to resistance is reduced when the conductive substrate is energized, so that heat generation can be suppressed and the device can be used at a low voltage. Further, for example, when used as a transparent conductive substrate for an electromagnetic wave shielding substrate of a flat panel display such as a plasma display panel or a liquid crystal television, the electromagnetic wave shielding property is good, which is preferable. Although the lower surface specific resistance of the transparent conductive substrate is preferable, the lower limit that can be practically achieved is considered to be about 1Ω / □, and therefore about 1Ω / □ is considered the lower limit.

  For the measurement of the surface specific resistance, for example, the reticulated metal fine particle laminated substrate is heat-treated at 150 ° C. for 2 minutes, placed in 1N hydrochloric acid, and left for 1 minute. Thereafter, the network-like fine metal particle multilayer substrate is taken out, washed with water, dried, left in a normal state (23 ° C., relative humidity 65%) for 24 hours, and in that atmosphere, in accordance with JIS-K-7194 (1994). And it can be measured using Loresta-EP (Mitsubishi Chemical Corporation make, model number: MCP-T360). If the surface specific resistance thus obtained is 30 Ω / □ or less, the conductivity is good.

  The substrate in the present invention is not particularly limited, and various substrates such as glass and resin can be used. In addition, a combination of two or more substrates such as glass and resin can be used.

  In the present invention, when the hydrophilic treatment layer is laminated on the surface of the substrate, it is preferable because the metal fine particles are easily laminated in a network shape. Such hydrophilic treatment layer is not particularly limited, but natural resins such as polyester, acrylic-modified polyester, polyurethane, acrylic resin, methacrylate resin, polyamide, polyvinyl alcohol, starches, cellulose derivatives, gelatin and the like. Polyvinyl pyrrolidone, polyvinyl butyral, polyacrylamide, epoxy resin, melamine resin, urea resin, polythiophene, polypyrrole, polyacetylene, polyaniline, various silicone resins and modified silicone resins can be used.

  In this invention, when a board | substrate is a thermoplastic resin film, it is preferable at points, such as being excellent in transparency, a softness | flexibility, and workability. The thermoplastic resin film as used in the present invention is a general term for films that are melted or softened by heat, and is not particularly limited, but representative examples include polyolefins such as polyester films, polypropylene films, and polyethylene films. Films, polylactic acid films, polycarbonate films, acrylic films such as polymethyl methacrylate films and polystyrene films, polyamide films such as nylon, polyvinyl chloride films, polyurethane films, fluorine films, polyphenylene sulfide films, and the like can be used.

  These thermoplastic resin films may be composed of homopolymers or copolymer polymers, but among these, in terms of mechanical properties, dimensional stability, transparency, polyester films, polypropylene films, Polyamide films are preferred, and polyester films are particularly preferred from the viewpoints of mechanical strength and versatility.

  In such a polyester film, polyester is a general term for polymers having an ester bond as a main bond chain, and includes ethylene terephthalate, propylene terephthalate, ethylene-2,6-naphthalate, butylene terephthalate, propylene-2, It is preferable to use one having at least one component selected from 6-naphthalate, ethylene-α, β-bis (2-chlorophenoxy) ethane-4,4′-dicarboxylate as a main component. it can. These constituent components may be used alone or in combination of two or more. However, when quality, economy and the like are comprehensively judged, polyester having ethylene terephthalate as a main constituent, that is, polyethylene terephthalate is used. It is particularly preferable to use it. In addition, when heat or shrinkage stress acts on the substrate, polyethylene-2,6-naphthalate having excellent heat resistance and rigidity is more preferable. These polyesters may further be partially copolymerized with other dicarboxylic acid components and diol components, preferably 20 mol% or less.

  The intrinsic viscosity (measured in o-chlorophenol at 25 ° C.) of such polyester is preferably 0.4 to 1.2 dl / g, more preferably 0.5 to 0.8 dl / g. It is suitable for carrying out the invention.

  Further, in such a thermoplastic resin, for example, polyester, various additives such as an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, an organic lubricant, a pigment, a dye, organic or inorganic fine particles, Fillers, antistatic agents, nucleating agents and the like may be added to such an extent that the properties are not deteriorated.

  Such a thermoplastic resin film, such as a polyester film, is preferably biaxially oriented. Such a biaxially oriented polyester film is generally obtained by stretching an unstretched polyester sheet or film about 2.5 to 5 times in the longitudinal direction and in the width direction, and then performing heat treatment to complete the crystal orientation. Yes, it indicates a biaxially oriented pattern by wide-angle X-ray diffraction.

  The thickness of such a thermoplastic resin film, such as a polyester film, is not particularly limited and is appropriately selected depending on the application and type, but from the viewpoint of mechanical strength, handling properties, etc., preferably 10 to 500 μm, More preferably, it is 38-250 micrometers, Most preferably, it is 75-150 micrometers. For example, when a polyester film is used as the substrate, a composite film by coextrusion may be used. On the other hand, a film obtained by bonding the obtained film by various methods can also be used.

  In addition to the substrate and the metal fine particle layer, various layers may be laminated on the network metal fine particle laminated substrate of the present invention. For example, although not particularly limited, an undercoat layer for improving adhesion may be provided between the substrate and the metal fine particle layer, or a protective layer may be provided on the metal fine particle layer. In addition, an adhesive layer, a release layer, a protective layer, an adhesion-imparting layer, a weather-resistant layer, or the like may be provided on one side or both sides of the substrate. In addition, when various layers are formed on the substrate surface on the side not having the metal fine particle layer, various layers can be formed without any particular limitation, but when various layers are provided between the substrate and the metal fine particle layer Note the following points. That is, when such various layers are provided between the substrate and the metal fine particle layer, it is important that the surface wetting tension of the various layers on the substrate to which the metal fine particle solution is applied is 45 mN / m or more and 73 mN / m or less. As long as these layers have the surface wetting tension described above, various layers can be provided on the substrate in the present invention.

  Hereinafter, although the manufacturing method of the network metal fine particle laminated substrate of this invention is illustrated and demonstrated more concretely, this invention is not limited to this. That is, a hydrophilic treatment layer is laminated on a biaxially stretched polyester film having a surface wetting tension of 47 mN / m, a silver fine particle solution is applied by a die coating method that does not come into contact with the substrate, and the silver fine particle layer is laminated in a mesh shape. By using the method for producing a reticulated metal fine particle multilayer substrate of the present invention, a reticulated metal fine particle multilayer substrate having excellent transparency and moire resistance and having no scratches or streaks on the coating film is obtained by a method having excellent productivity. be able to. Since the biaxially stretched polyester film described here has a surface wetting tension of 47 mN / m, a relatively excellent network metal fine particle multilayer substrate can be obtained without providing a hydrophilic treatment layer.

  Further, in order to obtain a transparent conductive substrate from the thus obtained mesh-like metal fine particle laminated substrate, for example, the mesh-like metal fine particle laminated substrate is heat-treated at 150 ° C. for 2 minutes and treated with acetone for 30 seconds. Put in 1N hydrochloric acid and let stand for 1 minute. Thereafter, the network-like fine metal particle multilayer substrate is taken out, washed with water, and dried to be suitably obtained.

The transparent conductive substrate using the reticulated metal fine particle multilayer substrate of the present invention has transparency and a high level of conductivity, and therefore, an electromagnetic wave shielding film used for flat panel displays such as plasma display panels and liquid crystal televisions. In addition, it can be suitably used for various conductive substrate applications such as circuit material applications and solar cell applications.
[Characteristic measurement method and effect evaluation method]
The method for measuring the characteristics of the conductive substrates prepared in each of the examples and comparative examples and the method for evaluating the effects are as follows.
(1) Airflow angle during metal fine particle layer lamination
The airflow angle was measured in a manufacturing process of laminating a metal fine particle layer on a substrate by placing a bar with a 2 cm thread at the tip parallel to the substrate at a location of 2 cm on the substrate to be laminated, as shown in FIG. Here, for the measurement, a polyester filament multifilament having a thickness of 140 dtex was used. In this measurement, it is not necessary to limit to this as long as it is a multifilament, and in addition to the polyester fiber, a polyamide fiber, a polyurethane fiber, or the like may be used. Further, the thickness of the yarn is preferably 70 dtex or more and 500 dtex or less, that is, if it is thinner than 70 dtex, it is difficult to confirm the airflow angle, and if it is thicker than 500 dtex, there is a possibility that the yarn does not flutter even if an airflow occurs.

Also, if the yarn attached to the tip of the rod is fluttering parallel to the substrate surface, the airflow angle is 0 degree, if it is fluttering vertically upward, the airflow angle is 90 degrees, and if it is fluttering vertically downward, the airflow angle is -90 degrees. It was. If the measured airflow angle was within ± 45 degrees from the parallel to the substrate surface, it was considered good.
(2) Wind velocity of the air current when the metal fine particle layer is laminated The wind velocity of the air current is measured using an anemometer CLIMOMASTER (made by MODEL 6531 Nippon Kanomax Co., Ltd.) in the production process of laminating the mesh metal fine particle layer on the substrate. On 1 cm above the surface of the substrate on which the metal fine particle solution was applied, the wind speed of only the airflow at the angle measured by the method for measuring the airflow angle described above was measured. At a certain point on the substrate, the wind speed when the probe was placed to receive the wind speed of the air flow at the angle measured above was measured for 30 seconds in a stationary state (see FIGS. 3 and 4). The maximum value measured for 30 seconds was taken as the wind speed of the airflow.
(3) Variation in the wind speed of the airflow in the width direction of the substrate when the metal fine particle layer is laminated Measurement of the variation in the wind speed of the airflow in the width direction of the substrate is performed by an anemometer CLIMOMASTER. (MODEL 6531 manufactured by Nippon Kanomax Co., Ltd.), the measurement method of the wind velocity of the airflow described in (2) above is performed on the surface of the substrate to which the metal fine particle solution is applied at a distance of 5 cm in the width direction of the substrate. And measured. If the range of the difference between the maximum value and the minimum value of the wind speed of the obtained air current was within 2 m / second, it was considered good without affecting the unevenness.
(4) Surface Wetting Tension The surface wetting tension of the substrate was measured according to JIS- in the atmosphere after leaving the substrate used in each example and comparative example in a normal state (23 ° C., relative humidity 50%) for 6 hours. It carried out in the form based on K-6768 (1999).

  First, the surface to be measured of the substrate is placed on the base of the hand coater, a few drops of the surface wetting tension test liquid mixture are dropped, and a wire bar capable of applying a WET thickness of 12 μm is immediately drawn and spread.

  The surface wetting tension is judged by observing the liquid film of the test mixed solution in a bright place and in the state of the liquid film after 2 seconds. If the liquid film is not torn and remains in the applied state for 2 seconds or longer, it is wet. When the wetting is maintained for 2 seconds or more, the process further proceeds to a liquid mixture with a high surface wetting tension. Conversely, when the liquid film is broken in less than 2 seconds, the process proceeds to a liquid mixture with a low surface wetting tension. This operation is repeated, and a liquid mixture that can wet the surface of the substrate accurately for 2 seconds or more is selected to obtain the surface wet tension of the substrate. The maximum surface wetting tension by this measurement method is 73 mN / m.

  The unit of surface wetting tension is mN / m.

(5) Surface observation (shape observation)
The surface of the reticulated metal fine particle multilayer substrate was observed with a differential interference microscope (LEICA DMLM manufactured by Leica Microsystems Co., Ltd.) at a magnification of 100 to observe the shape of the reticulated mesh.

(6) Surface Specific Resistance For measurement of surface specific resistance, the metal fine particle laminated substrate obtained in each Example / Comparative Example is heat-treated at 150 ° C. for 2 minutes, placed in 1N hydrochloric acid and left for 1 minute. Thereafter, the metal fine particle multilayer substrate is taken out, washed with water, dried, left in a normal state (23 ° C., relative humidity 65%) for 24 hours, and then in that atmosphere, in accordance with JIS-K-7194 (1994). Then, it implemented using Loresta-EP (Mitsubishi Chemical Corporation make, model number: MCP-T360). The unit is Ω / □.

In addition, this measuring device can measure below 1 × 10 ⁶ Ω / □. If the surface specific resistance is 30Ω / □ or less, the conductivity is good.

(7) Total light transmittance The total light transmittance was measured in a normal state (23 ° C., relative humidity 65%). After leaving the mesh-like metal fine particle laminated substrate for 2 hours, a fully automatic direct reading haze computer manufactured by Suga Test Instruments Co., Ltd. It measured using "HGM-2DP". The average value measured three times was taken as the total light transmittance of the network metal fine particle laminated substrate.

  If the total light transmittance is 50% or more, the transparency is good. In addition, in the case of the laminated substrate which laminated | stacked the metal fine particle layer only on the single side | surface of the board | substrate, the board | substrate was installed so that light may enter from the surface side which laminated | stacked the metal fine particle layer.

(8) Humidity on the substrate when forming the metal fine particle layer In the manufacturing process of laminating the network metal fine particle layer on the substrate, the humidity is set to CLIMOMASTER (MODEL 6531 made by Nippon Kanomax Co., Ltd.) 1 cm above the laminated substrate. Measured. Humidity was measured for 15 seconds or more above 1 cm from the center of the surface of the substrate on which the metal fine particle solution was applied, and was taken as a stable value.

(9) Temperature on the substrate when forming the metal fine particle layer In the manufacturing process of laminating the mesh metal fine particle layer on the substrate, 1 cm above the substrate to be laminated is CLIMOMASTER (made by MODEL 6531 Nippon Kanomax Co., Ltd.). Measured. The temperature was measured at 1 cm above the center of the surface of the substrate on which the metal fine particle solution was applied for 30 seconds or more, and was taken as a stable value.

(10) Unevenness of coating film The total light transmittance of the reticulated metal fine particle multilayer substrate was measured at intervals of 5 cm in the width direction using the method for measuring the total light transmittance of (7) above. If the maximum value and the minimum value of the measured total light transmittance are within 3%, unevenness of the coating film is not visually observed.
According to the above measurement method, the maximum value and the minimum value of the total light transmittance measured are within 3% as “◯”, and those exceeding 3% as “X”. did.
(11) Moire resistance The anti-moire phenomenon is generally caused by using a VIERA TH-42PX50 manufactured by Matsushita Electric Industrial Co., Ltd. as a plasma display on which an image is projected. The substrate was held so as to be parallel, and the substrate was rotated 360 ° while the screen and the surface of the substrate were kept substantially parallel, and it was evaluated by visually observing whether the moire phenomenon occurred during the rotation.

  The case where no moiré was observed was indicated by “◯”, and the case where moiré was observed was indicated by “x”. A case where moiré was partially observed was indicated as “Δ”. If the visual observation was “◯”, the moire phenomenon was considered good.

  In addition, when the metal fine particle layer was laminated | stacked only on the single side | surface of the board | substrate, it had the mesh-like metal fine particle laminated board so that the surface side which has not laminated | stacked the metal fine particle layer may oppose a display screen.

(12) Time for forming the network metal fine particle layer When the metal fine particle solution is applied to one surface of the substrate, the substrate immediately after the application is not transparent but becomes transparent as time passes. Here, the “time for forming the mesh metal fine particle layer” was evaluated as the time from the application of the metal fine particle solution to the formation of a transparent substrate. The case where this time was 30 seconds or less was evaluated as productivity ○, and the case where it exceeded 30 seconds was evaluated as productivity ×.

  Next, the present invention will be described based on examples.

(Metal fine particle solution 1)
As the metal fine particle solution 1, CE103-7 manufactured by Cima NanoTech, which is a silver fine particle solution, was used.
Example 1
A primer was applied to one side of a biaxially stretched polyethylene terephthalate film (Lumirror (registered trademark) U46 manufactured by Toray Industries, Inc., surface wetting tension 47 mN / m), and hydrophilic treatment was performed. The surface wetting tension of the substrate subjected to the hydrophilic treatment was 73 mN / m. Subsequently, the inside of the draft is evacuated, the substrate is set to a humidity of 30% RH, a temperature of 25 ° C., and the substrate is placed under an air flow so that the air flow is in a direction of 0 degrees from parallel to the substrate surface. The wind speed of the airflow was adjusted to 4 m / sec (the maximum value in the width direction was 4.0 m / sec and the minimum value was 3.5 m / sec). In this draft, the metal fine particle solution 1 was applied on the hydrophilic treatment layer of the biaxially stretched polyethylene terephthalate film by using an applicator method not contacting the substrate so as to have a WET thickness of 30 μm.

  The coated metal fine particle layer formed a laminated substrate (network metal fine particle laminated substrate) in which the silver fine particle layer was laminated 22 seconds after the application. This laminated substrate was network-like, had a total light transmittance of 80%, had excellent coating unevenness and “◯”, and also had good moire resistance and “◯”.

  Next, this laminated substrate was heat-treated for 2 minutes in a hot air oven (PHH-200 manufactured by Tabai Espec Co., Ltd.) at 150 ° C. Subsequently, the laminated substrate was immersed in acetone (manufactured by Sasaki Chemical Co., Ltd.) at 25 ° C. for 30 seconds (acetone treatment), and the laminated substrate was taken out and dried at 25 ° C. for 3 minutes. Next, in order to acid-treat the silver particle layer of this laminated substrate, it was immersed in 1N hydrochloric acid (1N hydrochloric acid manufactured by Nacalai Tesque Co., Ltd.) for 1 minute. Thereafter, the multilayer substrate was taken out, washed with water, and then dried for 2 minutes in a hot air oven (PHH-200 manufactured by Tabai Espec Co., Ltd.) at 150 ° C. in order to remove moisture.

The surface specific resistance of this laminated substrate (transparent conductive substrate) was 4Ω / □.
(Example 2)
The metal fine particle solution 1 was applied in the same manner as in Example 1 except that the airflow on the substrate was placed under an airflow of 30 degrees parallel to the substrate surface.

  The coated metal fine particle layer formed a laminated substrate (network metal fine particle laminated substrate) in which the silver fine particle layer was laminated 22 seconds after the application. This laminated substrate was network-like, had a total light transmittance of 80%, had excellent coating unevenness and “◯”, and also had good moire resistance and “◯”.

  Next, similarly to Example 1, the obtained laminated substrate was subjected to heat treatment, acetone treatment, acid treatment, water washing, and drying in this order.

The surface specific resistance of this laminated substrate (transparent conductive substrate) was 4Ω / □.
(Example 3)
The metal fine particle solution 1 was applied in the same manner as in Example 1 except that the airflow on the substrate was placed under a 45 ° airflow parallel to the substrate surface.

  The coated metal fine particle layer formed a laminated substrate (network metal fine particle laminated substrate) in which the silver fine particle layer was laminated 22 seconds after the application. This laminated substrate was network-like, had a total light transmittance of 80%, had excellent coating unevenness and “◯”, and also had good moire resistance and “◯”.

  Next, similarly to Example 1, the obtained laminated substrate was subjected to heat treatment, acetone treatment, acid treatment, water washing, and drying in this order.

The surface specific resistance of this laminated substrate (transparent conductive substrate) was 4Ω / □.
Example 4
The metal fine particle solution 1 was applied in the same manner as in Example 1 except that the air velocity of the airflow on the substrate was 8 m / sec (the maximum value in the width direction was 8.0 m / sec and the minimum value was 7.0 m / sec). .

  The coated metal fine particle layer formed a laminated substrate (network metal fine particle laminated substrate) in which the silver fine particle layer was laminated 10 seconds after coating. This laminated substrate was network-like, had a total light transmittance of 78%, good coating unevenness and “◯”, and also had good moire resistance and “◯”.

  Next, similarly to Example 1, the obtained laminated substrate was subjected to heat treatment, acetone treatment, acid treatment, water washing, and drying in this order.

The surface specific resistance of this laminated substrate (transparent conductive substrate) was 4Ω / □.
(Example 5)
The metal fine particle solution 1 was applied in the same manner as in Example 1 except that the air velocity of the airflow on the substrate was 1 m / sec (the maximum value in the width direction was 1.0 m / sec and the minimum value was 0.9 m / sec). .

  The applied metal fine particle layer formed a laminated substrate (network metal fine particle laminated substrate) in which the silver fine particle layer was laminated 30 seconds after the application. This laminated substrate was network-like, had a total light transmittance of 80%, had excellent coating unevenness and “◯”, and also had good moire resistance and “◯”.

  Next, similarly to Example 1, the obtained laminated substrate was subjected to heat treatment, acetone treatment, acid treatment, water washing, and drying in this order.

The surface specific resistance of this laminated substrate (transparent conductive substrate) was 4Ω / □.
(Example 6)
A primer was applied to one side of a biaxially stretched polyethylene terephthalate film (Lumirror (registered trademark) U46 manufactured by Toray Industries, Inc., surface wetting tension 47 mN / m), and hydrophilic treatment was performed. The surface wetting tension of the film subjected to hydrophilic treatment was 73 mN / m. Subsequently, the airflow on the substrate was exhausted using an exhaust fan, and the airflow was placed in a direction of 0 degrees from parallel to the substrate surface (the temperature on the substrate at this time was 25 ° C., and the humidity was 40%). Further, when the wind speed of the air flow was measured in the width direction of the substrate, the maximum value of the wind speed was 7 m / sec and the minimum value was 6 m / sec.

  Under this air stream, the metal fine particle dispersion 1 was applied on the hydrophilic treatment layer of the biaxially stretched polyethylene terephthalate film to the substrate by a die coating method so as to have a WET thickness of 30 μm.

  The coated metal fine particle layer formed a laminated substrate (network metal fine particle laminated substrate) in which the silver fine particle layer was laminated in 15 seconds after coating. The obtained laminated film was continuously heat-treated in an oven at 150 ° C. for 1 minute to obtain a reticulated metal fine particle laminated film.

  This laminated substrate has a mesh shape, the total light transmittance is 81%, the unevenness of the coating film in the width direction is good and “◯”, and the moire resistance is also good and “◯”. It was.

  Next, similarly to Example 1, the obtained laminated substrate was subjected to acetone treatment, acid treatment, water washing, and drying in this order.

The surface specific resistance of this laminated substrate (transparent conductive substrate) was 4Ω / □.
(Example 7)
The metal fine particle solution 1 was applied in the same manner as in Example 6 except that the maximum value of the air velocity in the width direction of the substrate was 7 m / second and the minimum value was 5 m / second.

  The coated metal fine particle layer formed a laminated substrate (network metal fine particle laminated substrate) in which the silver fine particle layer was laminated in 15 seconds after coating. The obtained laminated film was continuously heat-treated in an oven at 150 ° C. for 1 minute to obtain a reticulated metal fine particle laminated film.

  This laminated substrate has a network shape, the total light transmittance is 79%, the unevenness of the coating film in the width direction is good and “◯”, and the moire resistance is also good and “◯”. It was.

  Next, similarly to Example 1, the obtained laminated substrate was subjected to acetone treatment, acid treatment, water washing, and drying in this order.

The surface specific resistance of this laminated substrate (transparent conductive substrate) was 4Ω / □.
(Example 8)
The metal fine particle solution 1 was applied in the same manner as in Example 6 except that the maximum value of the air velocity in the width direction of the substrate was 5.5 m / sec and the minimum value was 4 m / sec.

  The coated metal fine particle layer formed a laminated substrate (network metal fine particle laminated substrate) in which the silver fine particle layer was laminated 20 seconds after the application. The obtained laminated film was continuously heat-treated in an oven at 150 ° C. for 1 minute to obtain a reticulated metal fine particle laminated film.

  This laminated substrate has a network shape, the total light transmittance is 79%, the unevenness of the coating film in the width direction is good and “◯”, and the moire resistance is also good and “◯”. It was.

  Next, similarly to Example 6, the obtained laminated substrate was subjected to acetone treatment, acid treatment, water washing, and drying in this order.

The surface specific resistance of this laminated substrate (transparent conductive substrate) was 4Ω / □.
(Comparative Example 1)
The airflow on the substrate was changed to 60 degrees from parallel to the substrate surface, and the airflow velocity was 8 m / sec (maximum value in the width direction was 8.0 m / sec and minimum value was 7.0 m / sec). The metal fine particle solution 1 was applied in the same manner as in Example 1.

The coated metal fine particle layer formed a laminated substrate in which the silver fine particle layer was laminated 10 seconds after coating. The total light transmittance of this laminated substrate was 79%, and the moire resistance was good and “◯”. However, the structure connected to the network was peeled off, and then the obtained laminated substrate was heat treated. However, the surface resistivity was greater than 1 × 10 ⁶ Ω / □.
(Comparative Example 2)
The metal fine particle solution 1 was prepared in the same manner as in Example 1 except that the air velocity of the airflow on the substrate was 0.1 m / second (the maximum value in the width direction was 0.1 m / second and the minimum value was 0.08 m / second). Applied.

  The applied metal fine particle layer formed a laminated substrate (network metal fine particle laminated substrate) in which the silver fine particle layer was laminated 90 seconds after the application. This laminated substrate had a mesh shape, had a total light transmittance of 79%, had excellent coating unevenness and “◯”, and also had good moire resistance and “◯”.

  Next, similarly to Example 1, the obtained laminated substrate was subjected to heat treatment, acetone treatment, acid treatment, water washing, and drying in this order.

  The surface resistivity of this laminated substrate (transparent conductive substrate) was 4Ω / □.

However, since it takes a long time of 90 seconds to form the network metal fine particle layer, problems such as inapplicability to a continuous process and an increase in cost cause problems.
(Comparative Example 3)
The metal fine particle solution 1 was prepared in the same manner as in Example 1 except that the air velocity of the airflow on the substrate was 12.0 m / sec (the maximum value in the width direction was 12.0 m / sec and the minimum value was 11.5 m / sec). Applied.

The coated metal fine particle layer formed a laminated substrate in which the silver fine particle layer was laminated 5 seconds after coating. The total light transmittance of this multilayer substrate was 80%, the moire resistance was good, and it was “◯”. However, the structure connected to the network was peeled off, and then the resulting multilayer substrate was heat treated. However, the surface resistivity was greater than 1 × 10 ⁶ Ω / □.
(Comparative Example 4)
A primer was applied to one side of a biaxially stretched polyethylene terephthalate film (Lumirror (registered trademark) U46 manufactured by Toray Industries, Inc., surface wetting tension 47 mN / m), and hydrophilic treatment was performed. The surface wetting tension of the film subjected to hydrophilic treatment was 73 mN / m. Subsequently, the inside of the hot air oven (PHH-200 manufactured by Tabai Espec Co., Ltd.) is adjusted to 25 ° C., 50% RH, and the wind speed scale is adjusted to 5.0 m / sec on the substrate (the maximum value in the width direction is 5). 0.0 m / sec, with a minimum value of 1.0 m / sec). At this time, the airflow angle on the substrate is not constant and is a turbulent airflow that changes in all directions, and the airflow angle may deviate from 0 ° to ± 45 °. In this oven, the metal fine particle solution 1 was applied on the hydrophilic treatment layer of the biaxially stretched polyethylene terephthalate film using an applicator method that does not contact the substrate so as to have a WET thickness of 30 μm.
The coated metal fine particle layer formed a laminated substrate (network metal fine particle laminated substrate) in which the silver fine particle layer was laminated 20 seconds after the application. The obtained laminated film was continuously heat-treated in an oven at 150 ° C. for 1 minute to obtain a reticulated metal fine particle laminated film.

  This laminated substrate was network-like, had a total light transmittance of 77%, had good moire resistance and was “◯”, but had a coating unevenness and was “x”.

  Next, similarly to Example 6, the obtained laminated substrate was subjected to acetone treatment, acid treatment, water washing, and drying in this order.

  The surface resistivity of this laminated substrate (transparent conductive substrate) was 4Ω / □.

  Table 1 shows the evaluation of Examples 1, 2, 3, 4, 5, 6, 7, and 8, and Comparative Examples 1, 2, 3, and 4.

  According to the method for producing a reticulated metal fine particle laminate substrate of the present invention, it is applied to a process of continuously applying a reticulated metal fine particle laminate substrate having both excellent transparency and moire resistance and excellent productivity. Can do.

  The transparent conductive substrate using the network-like fine metal particle multilayer substrate of the present invention has transparency and a high level of conductivity, and also has excellent moire resistance. For example, a flat plate such as a plasma display panel or a liquid crystal television is used. It can be suitably used for a panel display.

DESCRIPTION OF SYMBOLS 1 Laminated substrate 2 Air flow angle 3 Yarn 4 Bar 5 Probe 6 Measurement hole 7 Air velocity

Claims (8)

A method for producing a network-like metal fine particle laminate substrate in which a metal fine particle layer is laminated in a network form on a substrate by applying a metal fine particle solution on at least one side of the substrate,
After coating, the substrate is placed in an airflow in a direction within ± 45 degrees with the direction parallel to the substrate surface being 0 degree, and the air velocity of the airflow is 1.0 m / second or more and 10 m / second or less. A method for producing a reticulated metal fine particle multilayer substrate having a total light transmittance of 50% or more.   2. The method for producing a reticulated metal fine particle laminated substrate according to claim 1, wherein the temperature during application of the metal fine particle solution to the substrate in an air stream is 10 ° C. or more and 50 ° C. or less.   3. The network-like fine metal particle laminate according to claim 1, wherein the time for placing the substrate in an air flow in a direction within ± 45 degrees with respect to a direction parallel to the substrate surface is set to 30 seconds or less. A method for manufacturing a substrate.   The mesh-like fine metal particle multilayer substrate according to any one of claims 1 to 3, wherein the variation in the wind speed of the airflow in the width direction of the substrate is within 2 m / sec as a difference between the maximum value and the minimum value of the wind speed. Manufacturing method.   A transparent conductive material, characterized in that the metal fine particle layer of the network metal fine particle laminated substrate produced by the method according to any one of claims 1 to 4 is treated with an organic solvent after heat treatment and treated with an acid. A method for manufacturing a substrate.   A transparent conductive substrate obtainable by the production method according to claim 5.   The transparent conductive substrate according to claim 6, wherein the surface specific resistance is 30 Ω / □ or less.   A plasma display panel, wherein the transparent conductive substrate according to claim 6 or 7 is provided on the panel surface as an electromagnetic wave shielding substrate.