KR20210110906A - Method for coating silver on materials - Google Patents

Abstract

The present invention relates to a method for coating various materials with silver. The method for coating various materials with silver comprises: a step of processing the materials with plasma or corona by a plasma or corona generator apparatus; a step of soaking the plasma or corona-processed materials in a surface-active agent, and processing the materials for surface activation; a step of soaking the surface-activated materials in a mixture solution of a silver-stained material water solution and a reducing agent, and forming a silver film on a surface of the materials; a step of washing the materials with the silver film; and a step of drying the washed materials. In accordance with such a configuration, by coating the raw material particles with silver, the productivity is very excellent and the processing unit cost is low. The air pollution and water pollution can be minimized in the process of coating the materials with silver. The silver can be evenly dispersed in the materials of the finished products, so the sterilizing function can be constantly maintained.

Description

Method for coating silver on various materials {Method for coating silver on materials}

The present invention relates to a method for coating silver on various materials.

In general, silver (Ag) has an antibacterial or sterilizing function against 650 kinds of viruses and bacteria and is harmless to the human body.

Recently, silver having a unique sterilizing effect is contained and used in various household goods, factory equipment, public goods, clothing, bedding, and the like, and development to contain silver in products is continuously being made.

Conventionally, silver nano-materials are used to contain silver in products, functional polymer compounds are used, or some metals with partial antibacterial function are used to develop and supply products or materials that impart antibacterial function to the final finished product. .

However, in the case of a product using silver nanoparticles, there was a limit in increasing the content of silver nanoparticles in the raw material due to the increase in the difficulty and cost of the process for manufacturing the silver nanoparticles.

In addition, a method of coating silver nanoparticles on the surface of the final product using another coating medium has been proposed. There was a problem being

Another method was to crush the silver particles and mix them with the plastic material. However, the difference between the melting point of silver and the melting point of plastics was so large that in order to uniformly disperse the silver throughout the plastic, the silver particles had to be made very small. .

As described above, only a large amount of very expensive silver nanoparticles have to be injected into the plastic molded article or yarn to have effective antibacterial activity, thereby increasing the manufacturing cost of the product.

Accordingly, there is a need for a method capable of coating silver on various materials at a low cost and uniformly dispersing silver in the finished product material to maintain the sterilization function as in the initial stage of the product until the material itself is worn and completely disappeared.

Republic of Korea Patent Publication No. 10-2008-0031591

Therefore, the present invention was invented in consideration of the above circumstances, and by coating the raw material particles with silver, the productivity is very excellent and the processing cost is low, and the air and water pollution can be minimized in the process of coating silver on the material, , an object of the present invention is to provide a method of coating silver on various materials that can uniformly disperse silver in the finished product material and continuously maintain a sterilization function.

A method of coating silver on a material according to the present invention for realizing the object as described above, comprising the steps of plasma or corona treatment on the material by a plasma or corona generating device; Immerging the plasma or corona-treated material in a surface active agent for surface activation treatment on the material; forming a silver film on the surface of the material by immersing the surface-activation-treated material in a mixed solution in which a silver complex aqueous solution and a reducing agent are mixed; washing the material on which the silver film is formed; drying the washed material; includes

In addition, in the step of forming the silver film, the surface-activated material and the mixed solution are put into a stirring container and stirred.

In addition, in the step of forming the silver film, 40 to 90% of the silver complex aqueous solution and 10 to 60% of the reducing agent are mixed.

According to the present invention, by coating the raw material particles with silver, the productivity is very excellent, the processing unit cost is low, the air and water pollution can be minimized in the process of coating silver on the material, and the silver is uniformly dispersed in the finished product material Thus, it is possible to provide a method of coating silver on various materials that can continuously maintain a sterilization function.

1 is a process flow diagram illustrating a silver coating method according to the present invention.
2 is a configuration diagram for explaining a silver coating method according to the present invention.
3 is a view showing a step of producing a product by using the material manufactured according to the silver coating method of the present invention.
4 is a photograph showing the ABS material before and after coating silver.
5 is a photograph showing the PE material before and after silver coating.
6 is a photograph showing the PP material before and after coating silver.

Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Here, in adding reference numerals to the components of each drawing, it should be noted that only the same components are marked with the same reference numerals as much as possible even though they are displayed on different drawings.

1 is a process flow diagram illustrating a silver coating method according to the present invention. 2 is a configuration diagram for explaining a silver coating method according to the present invention. 3 is a view showing a step of producing a product by using the material manufactured according to the silver coating method of the present invention.

An object of the present invention is to provide a method of coating silver having an excellent function of neutralizing or killing 650 kinds of viruses and bacteria on various materials for manufacturing fibers, films, and plastic moldings.

1 and 2, the method of coating silver on the material of the present invention (hereinafter, silver coating method) includes a plasma or corona treatment step, a chemical surface activation treatment step, a silver film formation step, a water washing step, and a drying step do.

First, in the plasma or corona treatment step (S210), the material 10 in the form of granules supplied by a fixed amount from a supply unit such as the hopper 101 is poured onto the conveyor belt 110, and the material is uniform throughout the conveyor belt 110. The blade 115 is passed through so that it spreads to one thickness. For example, as the material, a number of materials such as Polyester, Nylon, Vinyl, PVC, HDPE, LDPE, PET, Urethane, Acryl, ABS, PC, PET-G, etc. can be applied.

The material has various shapes such as spherical, cylindrical, and pressed spherical depending on the characteristics of the material, and a diameter of 3 to 5 mm is suitable. If the diameter of the material is 3 mm or less, it is easy to detach from the conveyor belt during the manufacturing process. If the diameter of the material is 5 mm or more, the silver coating surface area is greatly reduced, and the silver content is reduced accordingly. In addition, if the thickness of the material is 5 mm or more, the output of the plasma or corona generating device (or plasma device) 120 must be greatly increased, so that suitability is deteriorated.

Next, the material is sensitized so that the silver particles can adhere well to the surface of the material while passing through the plasma device 120 . The plasma device 120 is manufactured by several domestic companies, and can be easily installed.

The plasma device 120 is installed to be close to the material within 10 mm according to the width of the conveyor belt 110 . The material passing through the blade 115 may be plasma-treated while passing through the plasma apparatus 120 . By plasma-treating the material, the surface adhesion of the material is improved, so that silver can be coated effectively in a later process.

Next, in the chemical surface activation treatment step (S220), in order to further increase the surface activity of the plasma-treated material, the surface of the material is immersed in the surface active agent, and then the material is sufficiently washed with ion-exchanged water. If the electrical resistance of deionized water used as washing water is 4~18MΩ, it can be used.

Next, in the silver film forming step ( S230 ), the silver complex aqueous solution and the reducing agent are mixed in a specific ratio and supplied into the stirring vessel 140 together with the surface-activated material. The stirring vessel 140 is equipped with a stirring blade 145 .

If the surface temperature of the inside of the stirring vessel 140, where the material and the chemical are in contact, is maintained at around 25°C to 40°C, it is the most efficient to uniformly adhere the silver particles to the surface of the material.

In order to perform uniform silver coating, the temperature of the mixed solution of the silver complex aqueous solution and the reducing agent in the stirring vessel 140 is adjusted to around 15 ~ 45 ° C. Keep it to move along the inside of the stirring vessel 140 for several tens of seconds so that the material can be coated with silver.

_{The silver complex aqueous solution can be prepared by dissolving silver nitrate (AgNO 3} ) or silver oxide (AgO) in purified water with a dilute aqueous sodium hydroxide solution or potassium hydroxide aqueous solution, and then adding aqueous ammonia.

The reducing agent may be an organic-inorganic composite reducing agent prepared by mixing various gluconic acid-based organic substances and sodium hydroxide or potassium hydroxide.

The ratio of the silver complex aqueous solution and the reducing agent supplied to the stirring vessel 140 is shown in Table 1.

Ingredient name Content (wt%) silver complex aqueous solution 40-90 reducing agent 60 to 10 Sum 100 1) The silver complex aqueous solution is prepared by mixing 1 mol of silver nitrate aqueous solution with potassium hydroxide aqueous solution.
2) As a reducing agent, 1 mol of sodium gluconate aqueous solution is used.

By this process, pure silver can be coated with a thickness of 0.1 to 0.4 μm on the surface of the material.

In order to minimize the external influence on each process and to increase the uniformity of the silver coating, the temperature of each chemical supplied into the container and the workplace, the temperature of the tank containing the chemical and the compressed air supplied, etc. are maintained at around 25℃. it is preferable

Next, in the washing step (S240), the silver film-coated material grains are discharged to the outside of the stirring vessel 140 and placed on the mesh-type conveyor belt 150, and the conveyor belt 150 is washed with purified water.

The waste liquid poured into the conveyor belt 150 together with the silver-coated grains passes through the conveyor belt 150 and is collected below. The collected waste liquid is transferred to a wastewater treatment company in a state where the outflow to the outside is blocked and undergoes a purification treatment process, so the leakage of chemical substances can be thoroughly prevented. In addition, odors or gases generated during the silver coating process are sucked into an exhaust duct installed on site, purified through nonwoven fabrics and carbon filters, and then exhausted.

In order to remove residues other than the pure silver film adhering to the material, a nozzle 155 is used to reciprocate in the washing section in the transverse direction to spray purified water. A control unit is installed so that the quantity, diameter, and injection quantity of the nozzles 155 can be adjusted.

Next, in the drying step (S240), compressed air is sprayed on the surface of the material with an intensity of about 2 to 3 bar from the air nozzle 156 installed on the conveyor belt 150 to remove moisture. In the same way as when the washing water is sprayed, the air nozzle 156 may reciprocate in the injection section in the transverse direction to spray compressed air. Alternatively, the conveyor belt 150 may reciprocate in the transverse direction.

Depending on the characteristics of the material, the moisture may be removed by dissipating heat of 30 to 90° C. from the hot air blower to dry it or by staying in the drying container 160 for 10 to 120 minutes.

In the method of coating silver of the present invention, volatile organic compounds are not used at all, and heavy metals or other regulated substances are not used at all to form a silver film, so it is eco-friendly.

In addition, since compressed air is not used in the steps of surface treatment, washing, and silver coating of the material, there is little concern about air pollution. In the process after the silver coating, compressed air can be used to blow out the ultrapure water (deionized water) used for washing. Therefore, it is possible to reduce the amount of air released into the atmosphere during the process.

In addition, it is possible to minimize the loss of a solution containing expensive silver by controlling the reaction rate and reaction concentration of the two solutions without using compressed air as a medium for moving the silver-containing complex and reducing agent. can

Referring to FIG. 3 , a process of injection into a plastic product or manufacturing into a fabric using a silver-coated material is described.

In the process of using a silver-coated material to inject into a plastic product, the silver-coated material is mixed with the plastic raw material and then injected. In the mixing step, the silver-coated plastic particles are uniformly melt-dispersed and mixed with the original uncoated silver particles in an appropriate ratio.

The high melt viscosity of the resin particles, high shear stress in the melt dispersion stage, and a very soft and extremely thin metal film, silver, can be uniformly distributed down to a size of ㎛ or less throughout the plastic.

In the injection stage, the particles that have passed through the mixing stage are injected into the designed shape through an injection molding machine. Since the injection molding machine uses the mixed particles as it is, it is possible to inject as it is in the same existing process without adding or removing process conditions or equipment.

For example, the products that contain silver of the present invention are plastic cups, cutlery, tableware, kitchenware such as knives and cutlery, toilet supplies, interior and exterior parts for water purifiers, etc. Various products that require an antibacterial or sterilizing effect harmless to the human body can be applied to

The process of manufacturing a fabric using a silver-coated material includes a mixing step, a yarn manufacturing step, and a fabric manufacturing step.

In the mixing step, the silver-coated material is uniformly melt-dispersed and mixed with the original uncoated silver material in an appropriate ratio. In the yarn manufacturing step, the yarn can be manufactured using the material that has undergone the mixing step. In the fabric manufacturing step, a fabric may be manufactured using a yarn containing silver.

The silver-containing fabric is manufactured by the silver coating method of the present invention, and thus it can be used for various fabrics such as clothes, bedding, and textiles requiring an antibacterial or sterilizing effect.

In the fabric manufactured by the present invention, silver is dispersed in a uniform concentration throughout the material, so as long as the shape of the material is maintained, the sterilization effect, which is an inherent function of silver, can be maintained.

In Table 2, the antibacterial effect of the injection-molded product containing silver according to the embodiment of the present invention and the general injection-molded product were compared.

The antibacterial performance standard in the government-approved antibacterial mark (SF mark) must be 2.0 (99.0%) or higher based on the antibacterial activity value or the bacteria reduction rate.

In this example, the antibacterial activity value for all four types of bacteria is 5.2 or more, which far exceeds 2.0 or more, which means that 99.99% or more of the initial bacteria are killed.

4 is a photograph showing the ABS material before and after coating silver. 5 is a photograph showing the PE material before and after silver coating. 6 is a photograph showing the PP material before and after coating silver.

4 to 6, the photo on the left shows the original material, and the photo on the right shows the silver-coated material. As shown in the photo, the silver film is uniformly coated on the material as a whole.

As described above, the silver coating method of the present invention can be applied simply and at low cost to various materials and equipment used for various purposes, household goods, and textiles with the antibacterial or sterilization function, which is a unique characteristic of silver metal. have.

In addition, by dispersing silver uniformly in the finished product material, it is possible to maintain the antibacterial or sterilization function against 650 types of viruses and bacteria at the same level as the initial product until the material itself is worn out and completely disappeared.

In addition, in the present invention, since a material other than silver is not contained in the coated material at all, if the raw material itself is not harmful to the human body, the finished product manufactured through the present invention is also not harmful to the human body.

It is obvious to those of ordinary skill in the art that the present invention is not limited to the above embodiments and can be implemented with various modifications or variations without departing from the technical gist of the present invention. will be.

10: material
101: Hopper
110: conveyor belt
115: blade
120: plasma device
130: immersion vessel
140: stirring vessel
145: stirring blade
150: conveyor belt
155: nozzle
156: air nozzle
160: drying container

Claims (3)

In the method of coating silver on a material,
Plasma or corona treatment on the material by a plasma or corona generating device;
Immerging the plasma or corona-treated material in a surface active agent for surface activation treatment on the material;
forming a silver film on the surface of the material by immersing the surface-activation-treated material in a mixed solution in which a silver complex aqueous solution and a reducing agent are mixed;
washing the material on which the silver film is formed;
drying the washed material;
A method of coating silver on a material containing According to claim 1,
In the step of forming the silver film, a method of coating silver on a material that is stirred by putting the surface-activated material and the mixed solution in a stirring container. According to claim 1,
In the step of forming the silver film, a method of coating silver on a material in which 40 to 90% of the aqueous silver complex solution and 10 to 60% of the reducing agent are mixed.

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