Transparent plate with conductive metal mesh as well as preparation method and application of transparent plate

Abstract

The invention relates to a transparent plate with a conductive metal mesh as well as a preparation method and application of the transparent plate. The preparation method comprises the following steps: S1, dissolving an acidic complex and nitrate in water, adding polyethylene glycol after the acidic complex and nitrate are completely dissolved, then adjusting the pH value to 1-3, and stirring at room temperature for 1-3 hours to obtain sol; s2, arranging the sol on the surface of a base material, and drying to enable the sol to form a cracking template; s3, a metal layer is arranged on the cracking template; the material of the metal layer comprises a conductive metal simple substance; s4, removing the cracking template by using an alkaline solution and / or water, and drying to obtain a transparent plate with a conductive metal mesh; the concentration of the alkaline solution is less than or equal to 0.1 mol / L. The technical problem to be solved is how to provide the preparation method of the transparent plate with the conductive metal mesh, the metal mesh made of elemental metal can be prepared by the method, the preparation is simple, the cost is low, and a cracked template is easy to remove.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal grids, and in particular relates to a transparent plate with a conductive metal grid, and a preparation method and application thereof. Background Art

[0002] Metal grid is a grid-like microstructure whose structural parameters (shape, period and line width, etc.) can be flexibly adjusted according to the use environment. The traditional preparation and processing methods of metal grid, such as direct writing, imprinting, photolithography, etc., are limited by the shape of the substrate, the processing area and the processing cost, and are difficult to apply to daily life. Therefore, people use the crack template method to prepare metal grid. The specific steps are as follows:

[0003] First, choose a suitable cracking liquid. If titanium dioxide is selected as the cracking liquid, first, apply the titanium dioxide cracking liquid on the surface of the transparent substrate and dry it. During the drying process, the titanium dioxide cracking liquid gradually dries and cracks to form a cracking template; secondly, set a metal layer on the cracking template; finally, remove the cracking template by mechanical friction to obtain a metal grid. However, when removing the cracking template, since the physical and chemical properties of titanium dioxide are too stable, the cracking template made of it can only be removed by mechanical friction. This removal method is not only complicated in process, but also mechanical friction will wear the substrate and the metal layer, affecting product performance.

[0004] Another method for preparing metal grids is to select a cracking paint containing water-based acrylic resin as the cracking liquid. First, the cracking liquid is coated on the surface of a transparent substrate and dried to form a crack template; second, a metal layer is set on the crack template; finally, the crack template is removed by using chloroform or propylene glycol methyl ether acetate (PGMEA) solution to obtain a metal grid. However, this method has very strict requirements on the drying time. If the drying time or drying temperature is not properly controlled, the crack width of the crack template will be uneven, thereby affecting the quality of the metal grid; and when the sprayed metal is a metal element, chloroform and PGMEA may react with the metal element, which will also affect the performance of the product. In addition, chloroform is considered a clear carcinogen, and PGMEA is flammable. These factors further limit the scope of use and promotion of this method. Summary of the invention

[0005] The main purpose of the present invention is to provide a transparent plate with a conductive metal grid, a preparation method and application thereof. The technical problem to be solved is how to provide a preparation method for a transparent plate with a conductive metal grid. The method can prepare a metal grid made of a single metal, has simple preparation, low cost, and easy removal of cracked templates.

[0006] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. According to the present invention, a method for preparing a transparent plate having a conductive metal grid comprises the following steps:

[0007] S1. dissolving the acidic complex and nitrate in water, adding polyethylene glycol after they are completely dissolved, and then adjusting the pH to 1-3, stirring at room temperature for 1-3 hours to obtain a sol;

[0008] S2. The sol is disposed on the surface of the substrate and dried to form a crack template of the sol;

[0009] S3. A metal layer is provided on the crack template; the material of the metal layer comprises a conductive metal element;

[0010] S4. Use an alkaline solution and / or water to remove the cracked template, dry it, and obtain a transparent plate with a conductive metal grid; the concentration of the alkaline solution is ≤0.1 mol / L.

[0011] Preferably, in the aforementioned preparation method, the nitrate is selected from at least one of ferric nitrate, cobalt nitrate, manganese nitrate and ammonium nitrate; and the acid complex is selected from any one of oxalic acid, citric acid and ethylenediaminetetraacetic acid.

[0012] Preferably, in the aforementioned preparation method, the added mass ratio of the acid complex to the nitrate is 1:1-3.3; the added mass ratio of the acid complex to the polyethylene glycol is 1:0.01-0.04.

[0013] Preferably, in the aforementioned preparation method, the alkaline solution is selected from at least one of sodium carbonate, sodium bicarbonate and ammonia water.

[0014] Preferably, in the aforementioned preparation method, the concentration of the alkaline solution is 0.05-0.1 mol / L.

[0015] Preferably, in the aforementioned preparation method, the material of the metal layer is selected from at least one of silver, copper and aluminum.

[0016] Preferably, in the aforementioned preparation method, the specific method of step S2 includes:

[0017] The sol with a thickness of 40 to 60 μm is disposed on the surface of the substrate, and then dried at room temperature for 8 to 12 hours or at 70 to 90° C. for 2 to 3 hours to form a crack template.

[0018] Preferably, in the aforementioned preparation method, the thickness of the metal layer is 100 to 300 nm.

[0019] The purpose of the present invention and the technical problems solved therein are also achieved by adopting the following technical solutions: A transparent plate with a conductive metal grid proposed in the present invention is prepared by the above-mentioned method for preparing a transparent plate with a conductive metal grid.

[0020] The purpose of the present invention and the technical problems solved therein are also achieved by adopting the following technical solutions: According to a metal grid electromagnetic shielding window proposed in the present invention, the electromagnetic shielding window comprises the above-mentioned transparent plate with a conductive metal grid.

[0021] By means of the above technical solution, the transparent plate with a conductive metal grid and its preparation method and application proposed by the present invention have at least the following advantages:

[0022] The traditional crack template method requires the use of solvents such as chloroform to remove the crack template due to the lysis solution, and chloroform will affect the formation of the single metal grid, resulting in a decrease in the performance of the obtained product. The present invention uses the crack template method to prepare a metal grid made of a single metal, and the material of the metal grid includes a conductive metal single substance, such as aluminum, silver, copper and other metal single substances; by setting a sol on the surface of the substrate and forming a crack template after drying, the formed crack template can be easily removed by water, dilute alkaline solution, etc., without damaging the metal layer, and the cracks of the crack template can be controlled by adjusting the raw materials of the sol, thereby controlling the line width of the metal grid, and obtaining a metal grid with desired performance.

[0023] The present invention uses a crack template method to prepare a metal grid, and the most important thing is the selection of a cracking liquid. The present invention forms a specific coordination compound by reacting an acidic complex with a nitrate, and then forms a corresponding sol system. This sol not only has a high viscosity and can be well coated on the surface of transparent materials such as PMMA and PC, but also forms a dry gel attached to the surface of the substrate after being completely dried, thereby forming a crack template. In the process of dry gel formation, due to the influence of the stress inside the sol itself, criss-cross cracks will be generated on the dry gel; then a layer of metal film is plated on the crack template, and the metal film layer at the crack is left on the transparent substrate after removing the dry gel mask using an alkaline solution or deionized water, and the corresponding transparent metal grid can be obtained after drying. The preparation method of the present invention can easily remove the crack template using a dilute alkaline solution and / or water, and the concentration of the alkaline solution is low, which can avoid corrosion of the single metal layer and the substrate, thereby ensuring the performance of the product; in addition, the method of removing the crack template of the present invention is simple and easy, and the production cost is low, and a metal grid with excellent performance can be prepared, which has a wide range of application prospects and promotion value.

[0024] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the preparation process of the transparent metal grid of the present invention. DETAILED DESCRIPTION

[0026] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of a transparent plate with a conductive metal grid and its preparation method and application according to the present invention, its specific implementation method, structure, characteristics and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0027] The present invention provides a method for preparing a transparent plate having a conductive metal grid, such as Figure 1 As shown, it includes the following steps:

[0028] S1. dissolving the acidic complex and the nitrate in water, adding polyethylene glycol after they are completely dissolved, and then adjusting the pH to 1-3, stirring at room temperature for 1-3 hours to obtain a sol; the added mass ratio of the acidic complex to the nitrate is 1:1-3.3; the added mass ratio of the acidic complex to the polyethylene glycol is 1:0.01-0.04; the nitrate is selected from at least one of ferric nitrate, cobalt nitrate, manganese nitrate and ammonium nitrate; the acidic complex is selected from any one of oxalic acid, citric acid and ethylenediaminetetraacetic acid; the water is preferably deionized water;

[0029] The present invention uses an acidic complex, a nitrate and polyethylene glycol to prepare a cracking liquid (inorganic coordination reaction), and the crack template prepared by using this cracking liquid can be easily removed by alkaline solutions and water. Compared with traditional cracking liquids such as titanium dioxide, the cracking liquid of the present invention has the advantages of being simple and fast, easy to operate and not easy to damage the formed metal grid when removing the crack template. In addition, the preparation method of the present invention also has higher flexibility and customizability, and the composition and concentration of the cracking liquid can be adjusted according to actual needs to adapt to substrate materials of different materials and specifications. At the same time, the size, shape and distribution of the cracks can be controlled by adjusting the process parameters to obtain a metal grid with the desired performance.

[0030] During the preparation process, adjusting the pH value of the reaction system is one of the key steps, and the pH value has a significant impact on the stability of the sol. Therefore, by adding ammonia water, the pH value of the system is adjusted to 1-3 to ensure the stability of the obtained sol, thereby avoiding the problem of uneven crack distribution and width of the crack template, and thus preventing the performance of the metal grid from deteriorating.

[0031] During the preparation process, the mixture needs to be stirred at room temperature for 1 to 3 hours until the reaction system begins to become viscous.

[0032] The substrate described in the present invention is a common transparent substrate on the market, and its material is polymethyl methacrylate (PMMA) or polycarbonate (PC) and other organic materials. The size of the substrate is 50mm×50mm×20mm (length×width×height), which is a size commonly used in laboratories, not the size of the product in actual production. The size of the substrate described in the present invention can be adjusted according to actual production needs. In addition, the surface of the substrate can be a flat surface or a curved surface, which can be adjusted according to actual production needs.

[0033] The present invention can adjust the reaction rate and reaction degree between the acid complex and the nitrate by controlling the ratio of the two, thereby affecting the formation and properties of the sol. In the present invention, the added mass ratio of the acid complex and the nitrate is controlled to be 1:1-3.3, and the added mass ratio of the acid complex and the polyethylene glycol is also required to be controlled to be 1:0.01-0.04. By accurately controlling the added amount of the raw materials, on the one hand, a sol with a suitable viscosity can be prepared so that it can be well adhered to the surface of transparent materials such as PMMA and PC; on the other hand, the internal stress of the sol itself can also be controlled so that the cracks on the formed crack template are evenly distributed and the width of the cracks is even, thereby improving the light transmittance and conductivity of the metal grid.

[0034] S2. The sol having a thickness of 40 to 60 μm is provided on the surface of the substrate, and then dried at room temperature for 8 to 12 h or at 70 to 90 ° C for 2 to 3 h to form a crack template;

[0035] The present invention uses a dropper or a coating machine to coat the sol on the surface of the substrate.

[0036] The present invention adopts the sol-gel method to prepare the crack mask. The generation of cracks is due to the formation of large stress at the central atom during the formation of the dry gel, which pulls the dry gel apart. The depth and width of the cracks can be regulated by controlling the content of the central atom and selecting different central atoms to adjust the stress of the dry gel. Compared with the traditional use of water-based acrylic resin as a crack mask, which utilizes the internal cracking caused by the water loss of water-based acrylic ester during the drying process, the method of the present invention can control the distribution and width of the cracks in the crack template, thereby obtaining a metal grid with the desired performance.

[0037] S3. A metal layer is provided on the crack template; the material of the metal layer comprises a conductive metal element; wherein the material of the metal layer is selected from at least one of silver, copper and aluminum;

[0038] S4. Use alkaline solution and / or water to remove the cracked template, dry it, and obtain a transparent plate with a conductive metal grid; the concentration of the alkaline solution is ≤0.1 mol / L; the alkaline solution is selected from at least one of sodium carbonate, sodium bicarbonate and ammonia water; the water is preferably deionized water.

[0039] The crack template prepared by the present invention can be easily removed by alkaline solution and water. This removal method is simple and fast. Compared with traditional chloroform or PGMEA, the use of alkaline solution and water is not easy to damage the metal grid formed by the conductive metal element, thereby ensuring the quality of the product.

[0040] The alkaline solution can be selected from common strong base and weak acid salts, such as sodium carbonate, sodium bicarbonate and other dilute solutions, which can effectively remove cracked templates without causing too much harm to the environment and human body. In addition, ammonia and other weakly alkaline substances can also be selected as alkaline solutions.

[0041] After removing the cracked template with alkaline solution and / or water, it is necessary to put it into an oven and dry it at 50-70° C. for 5-7 hours to finally obtain a transparent plate with a conductive metal grid.

[0042] Preferably, in the aforementioned preparation method, the nitrate is selected from at least one of ferric nitrate, cobalt nitrate, manganese nitrate and ammonium nitrate; and the acid complex is selected from any one of oxalic acid, citric acid and ethylenediaminetetraacetic acid.

[0043] The acidic complex of the present invention is selected from oxalic acid, citric acid and ethylenediaminetetraacetic acid (EDTA), etc., and other acidic raw materials that can be used as complexes can be used. Preferably, the acidic complex of the present invention is selected from oxalic acid or citric acid. In addition, the oxalic acid and citric acid used in the present invention are solid raw materials. In the preparation process, the citric acid or oxalic acid needs to be mixed with nitrate first, and then added to water together, wherein the mass ratio of citric acid or oxalic acid to water is 1:1 to 4.

[0044] The nitrate of the present invention is selected from at least one of ferric nitrate, cobalt nitrate, manganese nitrate and ammonium nitrate; preferably, the nitrate is selected from at least one of ferric nitrate, cobalt nitrate and manganese nitrate. When selecting the type of nitrate, one or more types can be selected for mixing, preferably one type. When one type of nitrate is selected as the raw material, it is easier to control the stress inside the sol.

[0045] Preferably, in the aforementioned preparation method, the added mass ratio of the acid complex to the nitrate is 1:1-3.3; the added mass ratio of the acid complex to the polyethylene glycol is 1:0.01-0.04.

[0046] The polyethylene glycol used in the present invention is polyethylene glycol 200 solution.

[0047] Preferably, in the aforementioned preparation method, the alkaline solution is selected from at least one of sodium carbonate, sodium bicarbonate and ammonia water.

[0048] Preferably, the alkaline solution is aqueous ammonia with a concentration of 0.05 to 0.1 mol / L.

[0049] Preferably, in the aforementioned preparation method, the concentration of the alkaline solution is 0.05-0.1 mol / L.

[0050] The concentration of the alkaline solution of the present invention is controlled at 0.05-0.1 mol / L. Too high a concentration will corrode the metal layer, resulting in a decrease in product performance.

[0051] Preferably, in the aforementioned preparation method, the material of the metal layer is selected from at least one of silver, copper and aluminum.

[0052] The metal layer of the present invention is provided by vacuum coating or evaporation coating, and vacuum coating is preferred.

[0053] Preferably, in the aforementioned preparation method, the specific method of step S2 includes:

[0054] The sol with a thickness of 40 to 60 μm is disposed on the surface of the substrate, and then dried at room temperature for 8 to 12 hours or at 70 to 90° C. for 2 to 3 hours to form a crack template.

[0055] Preferably, in the aforementioned preparation method, the thickness of the metal layer is 100 to 300 nm.

[0056] The present invention also provides a transparent plate with a conductive metal grid, which is prepared by the above-mentioned method for preparing the transparent plate with a conductive metal grid.

[0057] The present invention further provides a metal grid electromagnetic shielding window, which comprises the above-mentioned transparent plate material with a conductive metal grid.

[0058] The present invention will be further described below in conjunction with specific embodiments, but this should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0059] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0060] Example 1

[0061] The material of the substrate is PMMA, and the size of the substrate is 50 mm×50 mm×20 mm.

[0062] A method for preparing a transparent plate having a conductive metal grid comprises the following steps:

[0063] S1. Weigh 10 g of citric acid and 5 g of 50% manganese nitrate solution using an electronic balance;

[0064] S2. Mix citric acid and manganese nitrate solution in a round-bottom flask, add 20 g of deionized water, stir magnetically at room temperature until completely dissolved, add 0.2 parts of polyethylene glycol 200 solution, and after stirring completely, add 36% concentrated ammonia solution dropwise to adjust the solution pH to 2, stir magnetically at room temperature for 2 hours until the solution becomes partially viscous, and then stop to obtain a sol;

[0065] S3. The sol was coated on a PMMA transparent plate using a coating machine and dried at room temperature for 12 hours to obtain a crack template;

[0066] S4. A 200 nm thick metal Al film is deposited on the crack template using a vacuum coating machine, and the vacuum coating machine has a background vacuum of 1×10 -6 Torr, working vacuum is 1×10 -4 Torr, DC sputtering coating; then placed in a water tank filled with deionized water, after the dry gel crack template is completely removed, placed in an oven at 60°C for 6 hours, and finally a PMMA sheet with a transparent Al metal grid with a transmittance of 88% and a line width of 12 to 15 μm is obtained.

[0067] Example 2

[0068] A method for preparing a transparent plate having a conductive metal grid comprises the following steps:

[0069] S1. Weigh 5 g of oxalic acid and 3 g of 50% ferric nitrate solution using an electronic balance;

[0070] S2. The oxalic acid and ferric nitrate solution were mixed in a round-bottom flask, 10 g of deionized water was added, and after complete dissolution by magnetic stirring at room temperature, 0.1 parts of polyethylene glycol 200 solution was added thereto, and after complete stirring, a 36% concentrated ammonia solution was added dropwise to adjust the solution pH to 1, and magnetic stirring was stopped at room temperature for 1 hour until the solution became partially viscous to obtain a sol;

[0071] S3. The sol was coated on a PMMA transparent plate using a coating machine and dried at room temperature for 8 hours to obtain a crack template;

[0072] S4. A 100 nm thick silver film is plated on the crack template using a vacuum coating machine, and the vacuum coating machine has a background vacuum of 1×10 -6 Torr, working vacuum is 1×10 -4 Torr, DC sputtering coating was carried out; then it was placed in a water tank filled with deionized water, and after the dry gel crack template was completely removed, it was placed in an oven at 50°C for 5 hours to finally obtain a PMMA sheet with a transparent silver metal grid with a transmittance of 88% and a line width of about 10μm.

[0073] Example 3

[0074] A method for preparing a transparent plate having a conductive metal grid comprises the following steps:

[0075] S1. Weigh 8 g of citric acid and 4 g of 50% manganese nitrate solution using an electronic balance;

[0076] S2. Mix citric acid and manganese nitrate solution in a round-bottom flask, add 17 g of deionized water, stir magnetically at room temperature until completely dissolved, add 0.16 parts of polyethylene glycol 200 solution, add 36% concentrated ammonia solution dropwise after stirring, adjust the solution pH to 3, stir magnetically at room temperature for 3 hours until the solution becomes partially viscous, and then stop to obtain a sol;

[0077] S3. The sol was coated on a PMMA transparent plate using a coating machine and dried at room temperature for 10 hours to obtain a crack template;

[0078] S4. A 300 nm thick copper film is plated on the crack template using a vacuum coating machine, and the vacuum coating machine has a background vacuum of 1×10 -6 Torr, working vacuum is 1×10 -4Torr, DC sputtering coating; then placed in a water tank filled with deionized water, after the dry gel crack template is completely removed, placed in an oven at 70°C for 7 hours to finally obtain a PMMA sheet with a transparent copper metal grid with a transmittance of 85% and a line width of 20 to 30 μm.

[0079] Comparative Example 1

[0080] Compared with Example 1, this comparative example adopts the common crack template method on the market to prepare the metal grid, and the cracking liquid used is a crack film paint of water-based acrylic resin; chloroform is used to remove the crack template.

[0081] By comparison, it was found that the metal layer of Comparative Example 1 was corroded. This was because the metal grid was a single metal Al, which had a certain activity that could accelerate the decomposition or reaction of chloroform, resulting in certain damage to the metal grid by chloroform during immersion in the chloroform solution. However, the immersion in water in Example 1 of the present invention was much lower, and no corrosion occurred.

[0082] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0083] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a transparent plate having a conductive metal grid, It is characterized in that It includes the following steps: S1. dissolving the acidic complex and nitrate in water, adding polyethylene glycol after they are completely dissolved, and then adjusting the pH to 1-3, stirring at room temperature for 1-3 hours to obtain a sol; S2. The sol is disposed on the surface of the substrate and dried to form a crack template of the sol; S3. A metal layer is provided on the crack template; the material of the metal layer comprises a conductive metal element; S4. Use an alkaline solution and / or water to remove the cracked template, dry it, and obtain a transparent plate with a conductive metal grid; the concentration of the alkaline solution is ≤0.1 mol / L.

2. The preparation method according to claim 1, It is characterized in that The nitrate is selected from at least one of ferric nitrate, cobalt nitrate, manganese nitrate and ammonium nitrate; and the acid complex is selected from any one of oxalic acid, citric acid and ethylenediaminetetraacetic acid.

3. The preparation method according to claim 1, It is characterized in that The added mass ratio of the acid complex to the nitrate is 1:1-3.3; the added mass ratio of the acid complex to the polyethylene glycol is 1:0.01-0.

04.

4. The preparation method according to claim 1, It is characterized in that The alkaline solution is selected from at least one of sodium carbonate, sodium bicarbonate and ammonia water.

5. The preparation method according to claim 1, It is characterized in that The concentration of the alkaline solution is 0.05-0.1 mol / L.

6. The preparation method according to claim 1, It is characterized in that The material of the metal layer is selected from at least one of silver, copper and aluminum.

7. The preparation method according to claim 1, It is characterized in that The specific method of step S2 includes: The sol with a thickness of 40 to 60 μm is disposed on the surface of the substrate, and then dried at room temperature for 8 to 12 hours or at 70 to 90° C. for 2 to 3 hours to form a crack template.

8. The preparation method according to claim 1, It is characterized in that The thickness of the metal layer is 100-300 nm.

9. A transparent plate having a conductive metal grid, It is characterized in that The transparent plate material is prepared by the method for preparing a transparent plate material with a conductive metal grid as claimed in any one of claims 1 to 8.

10. A metal grid electromagnetic shielding window, It is characterized in that The electromagnetic shielding window comprises the transparent plate material having a conductive metal grid as claimed in claim 9.

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