KR100983807B1 - Method for electroless deposition of metalic silver and reflector of high reflectance deposited by metalic silver using the same - Google Patents

Abstract

PURPOSE: A method for electroless deposition of metal silver and a reflector of high reflectance deposited by metal silver using the same are provided to form a silver foil in a nano size by producing silver particles. CONSTITUTION: A method for electroless deposition of metal silver comprises next steps. Silver solution and reduction solution are respectively prepared. The silver solution and the prepared reduction solution are sprayed together to a fixed space, apart from substrate, in order to perform silver mirror reaction. The silver screen layer, in which the metallic silver is deposited, is formed. The silver screen layer has film density less than 3nm. The silver solution comprises ionic silver which can be reduced to the metallic silver.

Description

Method for Electroless Deposition of Metalic Silver and Reflector of High Reflectance deposited by Metalic Silver Using The same}

The present invention relates to electroless deposition of nano metallic silver, and is particularly useful when high reflectivity such as mirrors is required. For example, by spraying together a silver solution containing ionic silver which can be reduced to metallic silver and a reducing solution containing the silver solution reducing agent together in a predetermined area on the substrate (glass plate or quartz substrate) Metallic silver particles are produced, and the nano-sized metallic silver thus formed forms a silver film layer. The reflective plate thus obtained can exhibit high reflectance characteristics.

2. Description of the Related Art Conventionally, there are two main methods for imparting metallic luster to plastic molded articles such as automobiles and home electronic components. Among them, chrome plating and wet vacuum deposition are widely used. However, in the case of chromium plating, the toxic wastewater caused by hexavalent chromium is caused, and regulations are expanding around the world. In the case of vacuum deposition, productivity is low due to throughput limitations depending on facility investment cost and equipment size.

Also, generally, a reflecting plate such as a mirror is composed of a thin plate of a reflective metal film coated on a glass plate and its back surface. The metal film layer directly coated on the glass is usually a silver film, but other metal films such as copper may be used. When silver is used as the main reflective layer, it is usually protected with a second metal film layer of copper to suppress corrosion of the silver layer. In addition, paint layers are typically used in the silver or copper layers to enhance corrosion and wear resistance.

Here, the method for forming the silver film layer to be used as the reflective layer, as generally shown in US Patent 4,737,188, silver film by spray-blending a mixed solution of a silver ammonium nitrate solution and a reducing agent solution containing a strong base on the sensitized glass surface To calm.

However, as described above, when the silver film layer is formed by a general plating method of spraying a mixed solution of silver ammonium nitrate solution mixed with a reducing agent solution on a substrate, the film density of the formed silver film layer is low, and thus the reflectance is low to 70 to 80%. However, there is a disadvantage in that light leaks out, and there is a serious problem that the reflectance drops significantly when exposed to external environmental conditions.

In particular, even in the case of a large-scale solar reflector used for solar power generation, even if the reflectance of 1% can be increased, the operating period of the solar power plant can be extended to at least 20 years, and the operation rate by the reflectance, that is, the energy conversion rate can be increased. Can produce effect. Therefore, there is always a need to manufacture a reflector with a high reflectance even at 1%.

On the other hand, the Republic of Korea Patent No. 10-0766715 (electroless silver plating method using an amine) relates to the electroless silver plating method of generating a silver thin film on the substrate using an electroless plating solution containing silver ions and reducing agents. It controls the relative concentration of silver ions and amines to arbitrarily control the size of the silver particles constituting the silver thin film from tens of nanometers to several tens of micrometers, and the electroless silver plating to control the thickness of the silver thin film formed on the substrate. It is to provide a law. However, the film density of the specimen thus obtained was prepared at a level of 25 μm or less, which may have some optical and glossiness properties, but may not have a high reflectance, and no description of reflectance is given.

Further, Japanese Laid-Open Patent Publication No. 2001-46958 (Method of Forming a Coating Film with Metallic Gloss) is a method of forming a coating film having a metallic gloss characteristic on the surface of a plastic molded article such as an automobile part or a home appliance. Although two nozzles for spraying silver nitrate and a reducing agent at the same time are described, it is a wet plating method to have a metallic gloss on the surface of the plastic, but not for a reflecting plate having a high reflectance.

Accordingly, the present invention is to solve the above problems, in the electroless deposition of metallic silver and the like on a variety of substrates, including ionic silver which can be reduced to metallic silver, rather than electroless plating process by the deposition method. By spraying together a silver solution and a reducing solution containing the silver solution reducing agent together in a predetermined area on the substrate to produce metallic silver particles of 30 μs or less, and thus forming a silver film layer on which nano-sized metallic silver is deposited. It is about. In addition, the nano-sized metallic silver film layer thus formed is formed on the substrate with a thickness of 110 nm or more to provide a non-electrolytic deposition method of nano metallic silver to have a high reflectivity.

In addition, through the substrate on which the nano-sized metallic silver is deposited, it is intended to provide a reflector having a high reflectance with a high film density and a remarkably excellent reflectance characteristic.

The present invention for achieving the above object, preparing a reducing solution containing a silver solution containing ionic silver which can be reduced to metallic silver, and a reducing solution for the silver solution for reducing the silver solution; And spraying the prepared silver solution and the reducing solution together in a predetermined space away from the substrate, such that the silver mirror reaction is performed in the predetermined space away from the substrate. A deposited silver film layer is formed, and the silver film layer is an electroless deposition method of metallic silver, characterized in that it has a film density of 3 nm or less.

Here, it is preferable that the said board | substrate is a glass plate.

In addition, the present invention is a non-electrolytic deposition method of the metallic silver, wherein the silver solution further comprises other ionic metal in addition to the ionic silver, spraying the prepared silver solution and the reducing solution, the other ionic Heat-treating the silver solution further comprising a metal at a temperature within a range of 20 ° C. to 60 ° C. for a time within a range of 0.5 hours to 2 hours; Irradiating a neutron to the heat-treated silver solution; And spraying the neutron-irradiated silver solution and the prepared reducing solution together in a predetermined space away from the substrate.

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On the other hand, another embodiment of the present invention may be a reflecting plate comprising a silver film layer deposited by the above-described electroless deposition method of metallic silver and having a film density of 3 nm or less.

Here, the nano-size is preferably a diameter in the range of 2 ~ 30㎛, more preferably, the silver film layer has a thickness within the range of 110nm to 150nm.

Specific details of other embodiments are included in the detailed description and the drawings.

According to the present invention, a silver solution containing ionic silver which can be reduced to metallic silver and a reducing solution containing the reducing solution for the silver solution are sprayed together in a predetermined region on the substrate, thereby reducing the metallic silver particles of 30 μs or less. In addition, the nano-sized metallic silver thus produced has the effect of forming a silver film layer deposited at a thickness of 110 nm or more on the substrate.

In addition, by forming the silver particles of the silver film layer in the nano-size as described above, it is possible to provide a reflecting plate having a high film density and a remarkably excellent reflectance.

Since the reflector according to the present invention has a significantly higher reflection efficiency than the conventional solar reflector, it is possible to maximize the reflection efficiency by minimizing the light energy loss generated during the solar reflection, accordingly the solar power plant and the solar using the solar energy It is possible to improve the energy production characteristics in the optical CPV power generation system.

In addition, even when used as a reflector there is an effect that can image more sharp images.

Hereinafter, one preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is a method for electroless deposition of nano metallic silver. To this end, first, a silver solution containing ionic silver which can be reduced to metallic silver and a reducing solution containing the reducing agent for the silver solution are prepared, respectively.

The silver solution is a source of metallic silver (Ag) for forming the silver film layer. When the reducing solution is sprayed together with the silver solution, the ionic silver is reduced in a predetermined region in the process to precipitate metallic silver. Therefore, in a later step, when the silver solution and the reducing solution are sprayed together on a predetermined area on the substrate, nano metallic silver is precipitated by the silver mirror reaction, and the thus deposited metallic silver falls on the substrate to form a silver film layer.

The ionic silver may include all kinds of metal compounds, salts thereof, inclusion complexes, coordination compounds suitable for use as a reflective layer, and may be, for example, Ag ⁺ , and may be a reducing agent for the silver solution. Includes all kinds of reducing agents suitable for reducing the ionic silver contained in the silver solution to metallic silver.

Subsequently, the present invention sprays the silver solution and the reducing solution prepared as described above together in a predetermined region on the substrate. That is, the silver solution and the reducing solution are sprayed together, but sprayed together so that the sprayed silver solution and the reducing solution meet in a predetermined area on the substrate. In other words, even when the silver solution and the reducing solution are sprayed simultaneously, the sprayed silver solution and the reducing solution are sprayed so that the sprayed silver solution and the reducing solution meet in the air to achieve a silver mirror reaction. For example, the predetermined region on the substrate is preferably a constant space away from the substrate.

In general, a conventional spraying device is a nozzle is usually in a vertical direction from the top to the bottom, even if spraying a silver solution and a reducing solution at the same time, it must be sprayed separately to different areas on the substrate, accordingly While one solution of a silver solution and a reducing solution is already deposited on the substrate, and then another solution is deposited, a silver mirror reaction occurs on the surface of the substrate, but the present invention is intended to deposit metallic silver in a constant space away from the substrate. It is characterized by one.

To this end, the nozzle for spraying the silver solution and the reducing solution is preferably sprayed while inclined at an angle within the range of more than 0 ° to less than 90 ° with respect to the substrate, more preferably inclined to about 45 ° It is less.

As such, when the silver mirror reaction is carried out in a predetermined area on the substrate (preferably, a predetermined space away from the substrate), metal silver particles having a finer size than the conventional one can be formed. It is effective to increase the reflectance by increasing.

After numerous experiments and years of research, the inventors have found that the silver solution and the reducing solution have a temperature in the range of 20 ° C. to 35 ° C., and the silver solution and the reducing solution range from 1 to 2 equivalents with respect to 1 equivalent of the ionic silver. By volume of air in the range of 2 kg / cm 2 to 7 kg / cm 2, it is possible to form nano-sized particles having a diameter in the range of 2 kPa to 30 kPa when sprayed, at a rate in the range of 100 ml / min to 300 ml / min. Confirmed that the present invention, the present invention was completed.

Meanwhile, the silver solution may further include other ionic metals such as ionic aluminum, gold, nickel, and the like, in addition to the ionic silver, and the other ionic metal may be ionic aluminum.

When the silver solution contains only ionic silver, the silver nanoparticles of the nano-sized particles obtained by reduction are preferably contained in 99.95% by weight or more, and the silver solution further comprises another ionic metal. The silver nanoparticles are more preferably contained 99.75% by weight or more. This is because if included in the range below the reflectance in the short wavelength region can be lowered.

As such, the silver solution containing other ionic metals in addition to the ionic silver may be prepared by various methods. For example, aluminum nanoparticle powder may be mixed with a first solution containing ionic silver, or a first solution containing ionic silver and a second solution containing ionic aluminum may be mixed and prepared. It is also possible to prepare a silver solution containing both a salt form of silver and a salt form of aluminum.

Accordingly, in spraying the silver solution and the reducing solution, in order to prevent aggregation of the ionic silver and the other ionic metal contained in the silver solution, the silver solution further comprising the other ionic metal is 20 ℃ to It is possible to heat-treat for a time in the range of 0.5 to 2 hours at a temperature in the range of 60 ° C. Further, when irradiating the thermal neutron for several minutes to the heat-treated silver solution, there is an effect that can further reduce the aggregation of the particles.

According to the electroless deposition method of nano metallic silver as described above, it is possible to form a silver film layer in which nano-sized metallic silver is deposited on a substrate, and the present invention includes such a silver film layer. It may be a substrate.

Here, the nano-size is preferably a diameter in the range of 2 kHz to 30 kHz, because the reflectance and durability is lowered outside the range. In addition, it is more preferable that the silver film layer has a thickness within the range of 110 nm to 150 nm, because if it is less than the above range, ultraviolet rays or visible rays are likely to leak out, and even if the above range is exceeded, the effect does not increase significantly.

In addition, in the above-described non-electrolytic deposition method of the metallic silver and thus the substrate on which the metallic silver is deposited, the substrate may be a glass plate or a quartz substrate, and low iron glass is preferable as the glass plate. The reflector plate in which nano-sized metallic silver is deposited on the glass plate is used as a reflector, which is suitable for imaging a sharper image than before.

The invention may be better understood by the following examples, which are intended for purposes of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example 1 Electroless Deposition by Nano Silver Preparation

First, the silver solution was prepared as follows. That is, after dissolving 25.4 g of silver nitrate in 100 g of distilled water (pure water), the pH was adjusted to 10 to 11 using 10% ammonia water, and 2.5 g of a dispersant was added thereto, followed by 500 g of pure water using pure water. Adjusted to ml. The thus prepared solution was stirred and used as a silver solution while maintaining at -2 to 4 ° C.

As a reducing solution, 15 g of hydrazine hydrate and 30 ml of ethanol were dissolved in 455 ml of pure water, which was kept at 0 to 4 ° C and used as a reducing solution.

Then, while maintaining the temperature of the prepared silver solution and the reducing solution at 20 ~ 35 ℃, the silver solution and the reducing solution in an amount of 1 equivalent of hydrazine hydrate per 1 equivalent, glass plate (Asahi glass, thickness 3.2 mm, size 1m * 1m) was sprayed at a rate of 100 ~ 300ml / min by 2 ~ 7kg / ㎠ air pressure through each nozzle inclined at about 45 ° in the space 1 ~ 10cm above.

The inventors have confirmed that only nano-sized particles (preferably silver particles of 2 to 30 microns in size) can be obtained under the above air pressure conditions, equivalent conditions, temperature conditions and liquid volume conditions. Tables 1 to 5 below It is the result of such experiment.

Table 1: Results according to air pressure

       Less than 2 kg / ㎠        2-5 kg / ㎠      More than 5 kg / ㎠   10 ~ 200nm nonuniform particle formation         2 ~ 30 yen      Nanoparticles not formed

As a result of the air pressure, it was possible to obtain nanoparticles of 2 to 30 mm 3 only at 2 to 5 kg / cm 2.

Table 2: Results of Equivalent Changes

       Less than 1 equivalent        1-2 equivalents      More than 2 equivalents Nano Silver Metal Film Thickness is Inconsistent    Easy to control film thickness    Nano silver metal film not formed

As a result of the equivalent change, the thickness of the nano silver metal was not constant at less than 1 equivalent, the nano silver metal film was not formed at more than 2 equivalents, and the film thickness was easily adjusted only at 1 to 2 equivalents.

Table 3: Result of temperature change

       Less than 20 ℃        20 ~ 35 ℃            Above 35 ℃ Nanoparticles and metal film not formed, smeared         2 ~ 30 yen Agglomeration occurs, causing surface roughness

As a result of the temperature change, the nanoparticles and the metal film were not formed at less than 20 ℃, stains were formed, and the coagulation phenomenon occurred over 35 ℃ was a problem of surface roughness.

Table 4: Results according to the amount of liquid

        Less than 100ml        100-300 ml       Over 300 ml  Nano silver metal film thickness not controlled    Easy to control film thickness Nano Silver Metal Film Thickness Uncontrolled

Result of changes in liquid volume. At less than 100 ml and at more than 300 ml, the thickness of the nano-silver metal film could not be controlled.

Table 5: Thickness of Nano Silver Metal Membrane with Spray Time in 100 ~ 300ml Tank

         30 seconds       45 sec       50 seconds       60 seconds      90 sec          50 nm       70 nm     90 to 100nm      110 nm      150 nm

When the spraying time was set to 30 seconds, 45 seconds, 50 seconds, 60 seconds, and 90 seconds at a liquid amount of 100 to 300 ml, nano silver metal films having different thicknesses could be formed.

According to the above conditions, while the silver solution and the reducing solution is mixed in the space on the glass plate and the ionic silver contained in the silver solution is reduced, silver particles having a diameter of 2 ~ 30Å size was formed, the nano-formed thus Silver particles of size were deposited on the glass plate (see FIG. 1) to form a silver film layer having a thickness of 5 nm to 1 μm. Here, the thickness of the silver film layer may vary depending on the amount and time of spraying the silver solution and the reducing solution and the amount of the reducing agent, and in this embodiment, the thickness of the silver film layer is 50, 70, 100, 120 according to the spraying time. , Substrates of 130 and 150 nm were prepared, respectively.

Thereafter, it was sufficiently washed with pure water to remove unreacted material.

Nano silver particles in the substrate thus prepared were identified using a battery microscope Model Joel JSM 2401F.

Example 2: Non-electrolytic Deposition by Manufacturing Process Including Nano Silver and Aluminum

First, a silver solution containing ionic silver was prepared in the same manner as in Example 1.

In addition, an aluminum solution was prepared by dissolving 0.045 g of aluminum nitrate in 30 g of pure water separately, and mixing the silver solution with the prepared silver solution to prepare a silver solution containing ionic silver and ionic aluminum.

In addition, a total of 500 ml of reducing solution was prepared by mixing 8% d + glucose, 2% ethanol, and 3% caustic soda as reducing agents.

Then, while maintaining the temperature of the prepared silver solution and the reducing solution containing ionic aluminum and the reducing solution at 20 ~ 35 ℃, the nitric acid in the amount of d + glucose 2 equivalents to 1 equivalent, reducing with the silver solution 2-7 kg / ㎠ air pressure through each nozzle inclined at about 45 ° in a space 1-30 cm above the glass plate (Asahi glass, 3.2 mm thick glass plate, horizontal size * vertical size = 1 m * 1 m) Sprayed at a rate of 100-300 ml / min.

Accordingly, the silver solution and the reducing solution are mixed in the space on the glass plate and at the same time ionic silver (including ionic aluminum) contained in the silver solution is reduced, and silver particles having a diameter of 2 to 30 mm 3 (aluminum particles). And silver nanoparticles (including aluminum particles) thus formed were deposited on the glass plate (see FIG. 1) to form a silver film layer having a thickness of 5 nm to 1 μm. Here, the thickness of the silver film layer may vary depending on the amount and time of spraying the silver solution and the reducing solution and the amount of the reducing agent.

Thereafter, it was sufficiently washed with pure water to remove unreacted material.

Example 3: Electroless Deposition of Nanoparticles After Heat Treatment and Neutron Irradiation

First, silver solution was dissolved in 100g of distilled water (pure water), 17g of silver nitrate and 0.94g of aluminum nitrate, and then adjusted to pH 9.5 ~ 10.5 using 10% ammonia water, 2.5g of dispersant was added thereto, and then pure water The total solution was adjusted to 500 ml using. Thus prepared solution was stirred while maintaining at 2 ~ 4 ℃ was used as a silver solution containing ionic silver and ionic aluminum.

Here, unreacted ionic silver and ionic aluminum were removed through an ion exchange resin, in order to prevent the ionic silver and ionic aluminum from agglomerating, a silver solution containing the ionic silver and ionic aluminum. Was heat treated at a temperature of 25-50 ° C. for 0.5-2 hours, and heat neutrons were irradiated at 1.25 × 10 ⁹ n / cm ² / sec for 3 minutes.

And, the reducing solution was prepared in the same manner as in Example 2.

Thereafter, a silver solution containing ionic silver and ionic aluminum irradiated with the neutron and a reducing solution were sprayed in the same manner as in Example 2 to form a silver film layer on the glass plate. Here, the thickness of the silver film layer may vary depending on the amount and time of spraying the silver solution and the reducing solution and the amount of the reducing agent.

Comparative Examples 1 to 5: Reflective Plates Having Conventional Silver Film Layers

As a comparative example, a reflecting plate having the following structure was prepared.

Comparative Example 1: The reflection plate in which the silver plating layer was formed by the wet method on the glass plate was prepared. It has a structure in which a glass plate, a wet silver plating layer, a copper layer, and a plurality of paint layers are laminated in order, and is a reflector for solar energy which is widely used in the prior art commercially.

Comparative Example 2: A reflecting plate having a silver plated layer formed on an aluminum plate by a dry method was prepared. This is a vacuum deposition of 99.9% silver on an aluminum plate at 10 ^-6 Torr, the thickness of the silver plated layer is 3 kPa, and is a reflector for solar energy that has been widely used in the past for commercial purposes.

Comparative Example 3: The commercial plate which anodized the surface of the aluminum plate was prepared. This is an oxide film of the surface of an aluminum plate, and is a solar energy reflector plate which has been widely used for commercial purposes.

Comparative Example 4: A reflecting plate having a structure opposite to that of a conventional reflecting plate for solar energy, that is, having a protective layer instead of glass was prepared. This was spray coated with a polyester resin with a thickness of 20 μm on a silver film layer prepared according to Example 3 and dried to have a structure of a polymer coating surface layer / nano silver film / glass plate, and the polymer coating surface layer was tested as a front surface. .

Comparative example 5: The general mirror which laminated | stacked the silver film layer and the copper layer on the glass plate was prepared.

Experimental Example 1: Reflectance Measurement Test

The reflectance of the reflecting plates manufactured according to the above Examples and Comparative Examples was measured using Model Shimadzu UV-3100PC.

First, reflectance measurement results of a substrate (reflective plate) having a silver film layer having a thickness of 110 nm according to Example 1 and reflectors according to Comparative Examples 1 and 2 are as shown in FIG. 2. ④ in FIG. 2 is a spectrum of typical solar energy values. As shown here, in Comparative Examples 1 and 2 compared with Example 1, the reflectance was lowered in the visible-infrared region (approximately 380-1,000 nm), particularly in the short wavelength region (350-400 nm). Did not work well, the reflection efficiency fell.

And the reflectance measurement result of the board | substrate with which the silver film layer was formed in 110 nm thickness according to Example 1, and the reflecting plates which concerns on Comparative Examples 3 and 4 is shown in FIG. As shown here, in Comparative Examples 3 and 4, the decrease in reflectance in the visible light region (about 380 to 780 nm) was particularly severe as compared with Example 1.

In addition, as shown in FIG. 4, the reflectance measurement results of the substrate on which the silver film layer was formed to have a thickness of 110 nm according to Example 1 and the reflecting plate according to Comparative Example 5 were measured, in which the reflectance of Example 1 was measured to be high.

Experimental Example 2: Membrane Density Test

The film density of the reflecting plates manufactured according to the above Examples and Comparative Examples was measured by the light interference method using the Zaigo NV6300 model.

That is, as shown in FIG. 5, the substrate on which the silver film layer was formed with a thickness of 110 nm according to Example 1 can be confirmed that the surface of the silver film layer is densely flat, and the film density value measured by the Zaigo NV6300 model is also PV. 2.279 Ra 0.273 was excellent.

In contrast, in the reflective plate having the silver film layer formed by vacuum deposition according to Comparative Example 2, as shown in FIG. 6, the film density value was analyzed as PV 3.47 Ra 0.51, so that the film density of the reflective plate according to the present invention was remarkably increased. It can be seen that excellent.

7 is a schematic view for explaining the principle of the reflection efficiency according to the film density, as described above, the present invention has an excellent film density, it can have a high reflectance.

Experimental Example 3: Reflectance Test According to Silver Film Thickness

With respect to the reflective plate on which the silver film layer was formed in accordance with Example 1, light leakage was tested for each thickness of the silver film layer.

That is, in the reflector according to Example 1, the thickness of the silver film layer was differently formed into 50 nm, 70 nm, 100 nm, 110 nm, and 150 nm, respectively, and light leakage was measured by measuring reflectance using a Model Shimadzu UV-3100PC. .

As a result, as shown in FIG. 8 and the following [Table 6], when the thickness of the silver film layer is less than 100nm, light leakage was confirmed, and considering the generation level of infrared rays (light leakage level), It was found that the case of more than 110nm is the most preferable.

Table 6: Reflectance according to the thickness of the silver film layer of the present invention

 Silver layer thickness (nm)                  Light leaking by analysis (%)       UV-rays   Visible light infrared ray    50      Occur   Occur Occur    70      Occur   Occur Occur   100      None   None 0.06 level   110      None   None 0.03 level   120      None   None 0.03 level   150      None   None 0.03 level

Experimental Example 4: Measurement of reflectance of a reflector having a thickness of 110 nm

With respect to the reflector plate having the silver film layer formed according to Example 1 and Comparative Examples 1 to 5, the reflectance was measured to compare the quality with the existing reflector.

That is, in the reflector according to Example 1, the thickness of the silver film layer was formed to be 110 nm or more, and the reflectance was measured using a Model Perkin Elmer 1050. The results are shown in FIGS. 2, 3, 4, and [Table 7].

Table 7: Reflectance of the Invention

 Test Items     Contents   temperament Reflector material Initial reflectance
550nm (%) Total reflectance
350 ~ 2500nm  Short wavelength  Example 1  Example Sample    Glass   silver    96.4      -  Comparative Example 1 Commercial Solar Reflector    Glass   silver    93.5      90 Unreflected  Comparative Example 2  aluminum   silver    91.5      91  Comparative Example 3  aluminum Anodizing    89.0      87  Comparative Example 4 Reflector Front Resin Layer *    Glass   silver    87.0      89 No reflection  Comparative Example 5  Plain mirror    Glass   silver    87.0      80 No reflection

Experimental Example 5: Reflectance test according to the change over time

For the reflectors according to Examples 1 and 2 and Comparative Example 1, the initial reflectance in the visible region and the reflectance with time change were measured using Model Shimadzu UV-3100PC.

The reflectance according to the change over time is to check whether it maintains the continuous quality under external conditions such as high temperature, cold temperature, high humidity, and wind day and night. 3000 Xenon lamp, 2800KJ / ㎡ / Hr), humidity of 85% at a temperature of 60 ℃ temperature 500 hours, 1000 hours, 2000 hours, was exposed to 3000 hours, and then reflectance was measured to test the durability.

The results are as shown in Table 8 below. The initial reflectance was about 3% higher than the reflectors of Comparative Examples 1, and the reflectivity of the reflectors according to Examples 1 and 2 was about 3 to 4% superior after the durability test.

Table 8: Reflectance before and after durability test

 Test Items Early
reflectivity(%)      Reflectance after Durability Test (%)  500 hours 1,000 hours 2,000 hours 3,000 hours  Example 1    96.4    96.0    95.5    94.9    94.0  Example 2    96.6    96.2    95.6    95.2    94.1  Comparative Example 1    93.5    93.0    92.2    91.8    90.2

As shown in Table 2, even if the reflectance of the reflector according to the present invention is improved by only about 2%, an area of 2,000,000㎡ * energy conversion rate * reflectance according to 200MW SEGS Modeling Simulation at the annual unit productivity based on 200MW solar power plant It can have savings.

On the other hand, while the present invention has been shown and described with respect to certain preferred embodiments, the invention is variously modified and modified without departing from the technical features or fields of the invention provided by the claims below It will be apparent to those skilled in the art that such changes can be made.

The present invention is useful in the non-electrolytic deposition of metallic silver or the like on various ceramic substrates such as glass and quartz, particularly when high reflectivity such as mirrors is required. For example, by spraying together a silver solution containing ionic silver which can be reduced to metallic silver and a reducing solution containing the silver solution reducing agent together in a predetermined area on the substrate (glass plate or quartz substrate) By providing an electroless deposition method of metallic silver that can produce metallic silver particles and form a silver film layer on which the nano-sized metallic silver is deposited to a thickness of 110 nm, a highly efficient reflector on which nano-sized metallic silver is deposited is provided. can do.

1 is a photograph of an electron microscope (model name Joel JSM 2401F) of metallic nano silver having a size of 30 μs or less obtained by spraying together in a certain area of a spraying process according to the present invention.

2 is a graph showing the reflectance measurement results of the reflector according to Example 1 and Comparative Examples 1 and 2 according to the present invention,

3 is a graph showing reflectance measurement results of reflectors according to Example 1 and Comparative Examples 3 and 4 according to the present invention;

4 is a graph showing the reflectance measurement results of the reflector according to Example 1 and Comparative Example 5 according to the present invention,

5 is a photomicrograph showing a cross section of a reflector of Example 1 according to the present invention, and a graph photograph showing a film density value,

6 is a graph showing the film density value of the reflector of Comparative Example 2 according to the prior art,

7 is a schematic diagram for explaining the principle of reflection efficiency according to the film density in accordance with the present invention,

8 is a graph illustrating a result of measuring light transmittance according to the thickness of the silver film layer of the reflector according to Example 1 of the present invention.

Claims (5)

Preparing a silver solution containing ionic silver which can be reduced to metallic silver, and a reducing solution including a reducing agent for silver solution for reducing the silver solution; And, Spraying the prepared silver solution and the reducing solution together in a predetermined space away from the substrate, such that the silver mirror reaction is performed in the predetermined space away from the substrate; To form a silver film layer on which metallic silver having a diameter in the range of 2 GPa to 30 GPa is deposited, And said silver film layer has a film density of 3 nm or less. delete A reflecting plate comprising a silver film layer deposited by the deposition method according to claim 1 and having a film density of 3 nm or less. The method of claim 1, wherein the substrate is a glass plate. The method of claim 1, wherein the silver solution further comprises an ionic metal other than ionic silver, Spraying the prepared silver solution and reducing solution, Heat-treating the silver solution further comprising the other ionic metal at a temperature in a range of 20 ° C. to 60 ° C. for a time in a range of 0.5 hours to 2 hours; Irradiating a neutron to the heat-treated silver solution; And And spraying together the silver solution irradiated with the neutrons and the prepared reducing solution in a predetermined space away from the substrate.

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