KR20080001690A - Method of manufacturing steel pipe for water with antimicrobial and antipollution function - Google Patents

Abstract

A method of manufacturing a steel pipe for water having antimicrobial and antipollution functions is provided to reduce the roughness of an inner wall surface of a steel pipe for water to have an antipollution function. A method of manufacturing a steel pipe for water having antimicrobial and antipollution functions is to form a resin coating layer on the inner wall surface of the steel pipe for water by applying a resin coating agent in which epoxy paint, a diluting agent and a thinner are mixed to the inner wall surface. Nano-silver is added and mixed to the resin coating agent to be used in the coating of the inner wall surface of the steel pipe for water to make the inner wall surface of the steel pipe for water have antimicrobial effects and to reduce the roughness of the inner wall surface.

Description

METHOD OF MANUFACTURING STEEL PIPE FOR WATER WITH ANTIMICROBIAL AND ANTIPOLLUTION FUNCTION}

The present invention relates to a method for manufacturing water pipes (water and sewage pipes, agricultural water pipes, cast iron pipes, mold release pipes) having antibacterial and antifouling properties, and more specifically, of steel pipes for supplying water (water, sewage, agricultural water, industrial water). Manufacturing a water-resistant steel pipe having antibacterial and antifouling properties to coat the resin coating agent containing nano-silver particles on the inner wall surface to exhibit antibacterial function on the inner wall surface and to improve the antifouling property of the inner wall surface. It is about a method.

In general, water pipes for drinking water and sewage pipes for sewage / wastewater are classified into metal steel pipes mainly made of metal (eg, cast iron or zinc) and synthetic water pipes formed by molding of synthetic resin.

Among them, in the case of metal steel pipes, the inner surface of the metal pipe is likely to be corroded, and so-called 'scale' or foreign matter is deposited on the inner wall surface of the water pipe and provides an environment where various bacteria can inhabit. Therefore, there have been various attempts to prevent this and supply sanitary water.

For example, Korean Patent No. 10-384929 discloses a resin composition for antibacterial and antifungal water and sewage pipes, and an antibacterial and antifungal water and sewage pipe produced by the composition.

As another example of the synthetic resin water pipe, the plastic water pipe disclosed in Korean Patent No. 10-518960 may be mixed with charcoal powder having a particle size of 300 μm or less in a synthetic resin, and heated and kneaded and extruded in an extruder-type compounding machine to pellet chips. The chip was made by raw material or masterbatch and manufactured by extrusion molding method to have antibacterial, sterilization, deodorization, far infrared emission and heavy metal removal of charcoal in water pipe.

As another example, Korean Patent Publication No. 10-2006-68616 proposes a water pipe excellent in both tensile strength and low temperature impact strength due to the structural characteristics of the triple wall as well as the antimicrobial effect of preventing the habitat of microorganisms.

Here, in the case of the synthetic resin water pipes proposed in the above-mentioned Patent No. 10-384929 and Patent Publication No. 10-2006-68616, various kinds of additives (in addition to the antimicrobial component) are added to the resin composition as a main agent. 10-384929, dispersing and antioxidants and carriers, oxidizing agents, heat stabilizers, lubricants, etc .; in the case of Patent Publication No. 10-2006-68616, antistatic agents, heat stabilizers, impact modifiers, UV inhibitors, processing aids, etc.) are also added. Since water pipes made of synthetic resin are molded in the state of addition, various chemical components may be eluted (Elution, Migration) to plastic surface after molding, and may be mixed with drinking water (drinking water). Because the shape is made while passing through the dies of the extruder during the process, the surface is rough, unlike the injection products, in which the shape is formed in the mold mold under constant pressure. It is given, that harsh has the technical limit to prevent the foreign matter adhering to the inner wall surface of the resin.

In addition, the patent publications or patents use inorganic zeolite or charcoal as the antimicrobial agent, which is largely different from using silver (Ag), which is a nanoparticle of metal in terms of efficacy and durability of antimicrobial activity. There is no technique for preventing foreign matter deposited on the inner surface of the water pipe.

Accordingly, the present invention has been made in view of the above-described prior art, and coating a resin coating material containing an epoxy paint on the inner wall surface of a metal water pipe applied for drinking water or water supply, wherein the resin coating material is nano-antibacterial metal particles. Mixing silver ensures good antimicrobial properties on the inner wall even after a long time, and the surface roughness of the inner wall surface by the resin coating material mixed with the nano-silver is alleviated, so that the antifouling properties to improve the antifouling properties steel pipe for water The purpose is to provide a method of manufacturing.

In order to achieve the above object, according to a preferred embodiment of the present invention, in a water pipe for drinking water, such as water, the inner wall surface of the water pipe for diluents such as epoxy paints and curing agents and resin mixed with thinner for viscosity adjustment Coating with a coating agent to form a resin coating layer, by adding and mixing nano silver (silver (Ag) nanoparticles) to the resin coating agent to coat the inner wall surface of the steel pipe for water, to have an antimicrobial power on the inner wall surface of the steel pipe for water. At the same time, there is provided a method for producing a water steel pipe having an antimicrobial and anti-pollution in which an average surface roughness of the inner wall surface of the water pipe is reduced.

Preferably, the silver (Ag) nanoparticles added to the resin coating agent has a particle size of 1 to 20 nm, and the added concentration is 0.001 to 0.05% (10 to 500 ppm) based on the weight of the mixture of the epoxy paint and the diluent. Is set to.

The silver (Ag) nanoparticles are prepared from a metal salt and a material selected from raw materials of silver nitrate (AgNO ₃ ), silver chloride (AgCl), and silver acetate (CH ₃ COOAg) as compounds. And pulverized silver (Ag) particles physically small to nano size, and those prepared by pulverizing silver (Ag) in a wire state and then pulverizing it by an electrical explosion.

In addition, the silver (Ag) nanoparticles obtained through the dispersion and stabilization of silver (Ag) nanoparticles from the metal salt and the compound containing silver (Ag) contain a surfactant as the acceptor and contain the silver (Ag). The metal salts and compounds were dissociated and ion-reduced to extract silver (Ag) of the metal, and the metal salts and compounds containing silver (Ag) were dissociated and ion-reduced to extract silver (Ag) of the metal, and silica and zeolite and Manufactured by stabilizing one selected from zirconium phosphate as a carrier, and prepared by dispersing and stabilizing by coating and mixing silicon oxide on the surface of silver nanoparticles, and silver ( Ag) -containing metal salts and compounds are prepared by mixing a polymer stabilizer, dissolved in a solvent, purged with nitrogen and then irradiated with gamma rays.

Preferably, when the silver (Ag) nanoparticles are manufactured in colloidal form, the solvent used is isopropyl alcohol, methyl ethyl ketone, in order not to inhibit the physical properties of the epoxy paint. It is assumed that a solvent in which one or two or more of toluene is mixed is used.

In the production of water pipes having antibacterial and antifouling properties according to the present invention, the inner wall surface of the applied metal steel pipe is a mixture of epoxy paint, diluent and thinner, and has a nano silver particle size of 1-20 nm as an antimicrobial agent. Since it is coated with a resin coating agent obtained by adding at a concentration of ˜500 ppm, the amount of nano silver used as an antimicrobial agent is minimized, and excellent antimicrobial effect can be continuously obtained even during long-term use.

In addition, since the nano silver particles are mixed with the resin coating agent coated on the inner wall surface of the water pipe, the nanoparticles are mixed with epoxy paint to fill the rough grooves on the surface thereof, thereby making common resin coating agents on the inner wall surface. Compared to the case where only coating is performed, the surface roughness is gentle, thereby reducing the possibility of adsorbing or depositing foreign substances.

In general, foreign matter is adsorbed on the inner surface of the water pipe, the organic material mixed in the water flowing into the water pipe is adsorbed and deposited, the organic material is attached to the irregular and rough surface of the inner surface of the steel pipe This means that bacteria form biofilms (bacterial membranes) in the process, or bacterial membranes are formed and bacteria are accelerated in the process of decomposing bacteria by feeding plastics or metals.

Therefore, when the metal nano silver is mixed with epoxy resin on the inner wall of the water pipe, the surface roughness of the inner surface of the conduit is alleviated, and at the same time, the surface area of the inner pipe of the water pipe is reduced, thereby reducing the adsorption of foreign substances and at the same time, Since the formation of this biofilm (bacterial film) can be initially blocked, it is possible to obtain an effect of simultaneously solving a problem that conventional synthetic conduits cannot solve while using a metal water pipe.

Hereinafter, preferred embodiments of the present invention will be described in detail.

First, according to the water-resistant steel pipe made of, for example, metal having antibacterial and antifouling properties produced by the present invention, the outer surface of the water-steel pipe having a predetermined diameter and having a predetermined length is extruded as an anticorrosive layer to prevent corrosion. It is preferable that the polyethylene (PE) formed by the formula and powder welding is coated with three layers of the polyethylene (PE) formed by the extrusion type and powder welding as the anticorrosive protective layer.

According to the present invention, in order to prevent corrosion by dissolved oxygen in water on the inner wall surface of such a metal water steel pipe, a coating is performed by a liquid resin coating agent mainly based on epoxy paint, and the resin coating agent is nanosilver. (That is, silver (Ag) nanoparticles) by mixing the appropriate amount to be coated on the inner wall surface of the steel pipe for water to obtain long-term antimicrobial effect and improved antifouling effect by nano silver.

More specifically, according to the present invention, the resin coating agent is mixed with 0.1 to 0.5wt% of a diluent and a small amount of thinner for viscosity adjustment with respect to 18 liters of liquid epoxy paint (l), and the epoxy paint and the diluent are mixed. The silver (Ag) nanoparticles having a size of 1 to 20 nm as an antimicrobial agent were mixed with the prepared mixture at a concentration of 0.001 to 0.05% (10 to 500 ppm) based on the mixed weight of the epoxy paint and the diluent.

In the present invention, the silver (Ag) nanoparticles are one of the metal salts and the raw material of silver nitrate (AgNO _{3 )} , silver chloride (AgNO _{3 )} , silver acetate (Silver acetate; CH ₃ COOAg) as the metal salt and compound It is selected from the ones made from the material, the finely pulverized silver (Ag) particles in the nano-size, and the one produced by the production of silver (Ag) in a wire state and then crushed by an electrical explosion, the present invention The selected silver nanoparticles are characterized in that they are mixed with the resin coating agent of the epoxy paint and the diluent.

 Examples of the silver (Ag) nanoparticles obtained through dispersion and stabilization of silver (Ag) nanoparticles from the metal salts and compounds containing silver (Ag) include metal salts containing a surfactant as the acceptor and Compounds obtained by dissociating and ion-reducing the compound to extract silver (Ag), and metal salts and compounds containing silver (Ag) are dissociated and ion-reduced to extract silver (Ag) of the metal, and silica, zeolite and zirconium phosphate are extracted. And a metal salt and a compound containing silver (Ag) prepared by coating and mixing the silicon oxide on the surface of the silver nanoparticles to have dispersion and stability. It includes a polymer stabilizer is mixed by dissolving in a solvent and purged with nitrogen and then irradiated with gamma rays.

In addition, according to the present invention, when the silver (Ag) nanoparticles are prepared in a colloidal form, the solvent used is isopropyl alcohol, isopropyl alcohol, methyl ethyl ketone, or toluene. It is characterized by including two or more mixtures.

In the manufacturing process of the water-resistant steel pipe having antibacterial and antifouling properties according to the present invention, after the metal water pipe having a constant diameter and length is formed, the polyethylene (PE) 3-layer coating and anticorrosion formed by extrusion and powder welding as an anticorrosive layer on the outer surface thereof. As the protective layer, polyethylene (PE) formed by extrusion and powder welding is coated with three layers.

The water pipe for which the polyethylene (PE) is coated on the outer surface with three layers of the anticorrosive layer polyethylene (PE) coating and the anticorrosive protective layer is subjected to a surface treatment to remove foreign substances such as oil or rust or dust on the inner surface. do.

After the surface treatment is performed on the inner wall surface of the steel pipe for water, the resin coating agent mixed with the epoxy paint, the diluent, and the nano silver is coated on the inner surface by a spray coater.

Here, the resin coating layer by the resin coating material formed on the inner wall surface of the water steel pipe is sprayed to be formed to 300 ~ 500㎛.

Therefore, the metal water steel pipe according to the present invention can be continuously obtained antimicrobial effect even after long-term use because nano silver is applied as an antimicrobial agent on the inner wall surface, hygienic water supply as well as the inner wall surface of the conduit eroded by bacteria Can be prevented.

At the same time, according to the present invention, the surface roughness of the inner wall surface is gentler than the general water steel pipe forming the resin coating layer to which the nanosilver is not applied. The coefficient of friction and the surface area of the inner wall are reduced, which is desirable because the likelihood that foreign matter, an organic substance called 'scale', is deposited on the inner wall of the water pipe is reduced.

That is, Figure 1a is a scanning probe microscope image photograph of the surface roughness by coating the inner wall surface of the steel pipe for water with a resin coating agent mixed with an epoxy paint and a diluent is not mixed with nano silver, Figure 1b The measurement data of the surface roughness of the atomic force microscope image photograph shown in 1a is a diagram showing the average surface roughness (average roughness) of the inner wall surface of the steel pipe for water in that case was 0.282㎛.

On the other hand, Figure 2a is a mixture of the above-described epoxy paint and diluent, for example, nano silver nano-silver having an average particle size of 7nm at a concentration of 100ppm (ie 0.01% by weight of the mixed weight of the epoxy paint and diluent) for the water It is an atomic force microscope image photographed on the inner wall surface of the steel pipe to measure the surface roughness, Figure 2b is a diagram showing the measurement data showing the surface roughness of the atomic microscope image photograph shown in Figure 2a.

3 is a TEM (Transmission Electronic Microscope) photograph showing a state in which nanosilver having an average particle size of 7 nm is distributed on the inner wall surface of a water pipe according to the present invention.

According to the present invention, the inner wall surface of the water steel pipe in the state in which the nano-silver having an average particle size of 7 nm shown in the TEM picture of FIG. 3 is coated on the inner wall surface of the water steel pipe by a resin coating agent mixed with an epoxy paint and a diluent The average surface roughness of was observed to be 0.114 μm (see FIG. 2B), and it can be seen that the surface of the inner wall has a surface roughly 50% or more smoother than that of FIGS. 1A and 1B.

Therefore, the average surface roughness of the inner wall surface when the resin coating layer is formed by coating a resin coating agent mixed with nano silver on the inner wall surface of the steel pipe for water from the comparison result of the atomic microscope image shown in FIGS. 1A and 2A It can be seen that the reduction of the surface roughness decreases the coefficient of friction with the flowing water on the inner wall surface, which leads to the reduction of the surface area of the inner wall surface, thereby reducing the possibility of depositing foreign substances on the inner wall surface of the water pipe. It can be seen.

In addition, in order to measure the antimicrobial activity of the steel pipe for water according to the present invention spraying the resin coating agent mixed with the epoxy paint, diluent and nanosilver on the inner wall surface of the water pipe according to the present invention to form a resin coating layer and then tested the antimicrobial activity on the inner wall surface of the water pipe Proceeded, and the results are as follows.

First, as a control specimen, nano silver was not mixed, and a resin coating agent of only epoxy paint and diluent was prepared with a sample surface area of 25 cm 3. ATCC 8739; strain 2), Stomacher 400® POLY-BAG as standard coating film, and the test cell was cultured at RH 90 ± 5% for 24 hours under 35 ± 1 ℃. Was measured (antibacterial activity JIS2801 mutatis mutandis) (test 1), and the results are shown in Table 1.

In Table 1 below, the antimicrobial activity value (S) is log (Mb / Mc), reduction rate (%): [(Mb-Mc) / Mb] × 100, proliferation value (F): log (Mb / Ma) ( 1.5 or more), and Ma is the average number of viable cells immediately after inoculation of the test bacteria of the sample (3 samples), Mb: average number of viable cells (3 samples) after culturing for a predetermined time (24 hours) of the standard sample, and Mc: The average number of viable cells (3 samples) after incubation for 24 hours in antimicrobial samples.

                      Test strain contents   Strain 1: Staphylococcus aureus ATCC 6538P     Inoculation bacteria concentration (CFU / mL) 2.6 × 10 ⁵     Proliferation Rate (F)                  1.6       Ma 2.6 × 10 ⁵       Mb 1.1 × 10 ⁷       Mc 9.0 × 10 ⁶     Antibacterial Activity (S)-Reduction (%)               (0.1) 18.4     Nonionic Surfactant Type              TWEEN 80 (0.05%)

                      Test strain contents   Strain 2: Escherichia coli ATCC 8739     Inoculation bacteria concentration (CFU / mL) 2.5 × 10 ⁵     Proliferation Rate (F)                  1.7       Ma 2.5 × 10 ⁵       Mb 1.4 × 10 ⁷       Mc 1.1 × 10 ⁷     Antibacterial Activity (S)-Reduction (%)               (0.2) 24.9     Nonionic Surfactant Type              TWEEN 80 (0.05%)

CFU = Colony Forming Unit

As can be seen from Table 1 as a result of the above test 1, the reduction rate of strain 1 (yellow staphylococcus) and strain 2 (E. coli) as test strains in the case of only the nano-silver is not mixed and the epoxy paint and diluent only 19.4 It can be seen that the antibacterial activity is not exhibited because only% and 24.9% are reduced.

On the other hand, according to the present invention, the sample was prepared by mixing a 1-20 nm size silver (Ag) nanoparticles with a concentration of 10 ppm with an epoxy paint and a diluent to prepare a sample surface area of 25 cm 3 and the same test conditions as in the above Test 1. The antimicrobial activity was tested (test 2) under Table 2. Table 2 shows the antimicrobial test results of the test 2.

                      Test strain contents   Strain 1: Staphylococcus aureus ATCC 6538P     Inoculation bacteria concentration (CFU / mL) 2.6 × 10 ⁵     Proliferation Rate (F)                  1.6       Ma 2.6 × 10 ⁵       Mb 1.1 × 10 ⁷       Mc 2.2 × 10 ⁴     Antibacterial Activity (S)-Reduction (%)               (2.7) 99.8     Nonionic Surfactant Type              TWEEN 80 (0.05%)

                      Test strain contents   Strain 2: Escherichia coli ATCC 8739     Inoculation bacteria concentration (CFU / mL) 2.5 × 10 ⁵     Proliferation Rate (F)                  1.7       Ma 2.5 × 10 ⁵       Mb 1.4 × 10 ⁷       Mc               <10 (= less than 10)     Antibacterial Activity (S)-Reduction (%)               (6.2) 99.9     Nonionic Surfactant Type              TWEEN 80 (0.05%)

CFU = Colony Forming Unit

As shown in Table 2 as a result of the above test 2, the reduction rate of strain 1 (Staphylococcus aureus) and strain 2 (E. coli) as the test strain is reduced by 99.8% and 99.9%, respectively, it can be seen that sufficient antibacterial activity is exhibited. have.

In addition, according to the present invention, a sample prepared by mixing a 1-20 nm size silver (Ag) nanoparticle with a concentration of 50 ppm with an epoxy paint and a diluent at a sample surface area of 25 cm 3 was prepared under the same test conditions as in Test 1 above. Antibacterial activity was tested (test 3), Table 3 shows the results of the test 3.

                      Test strain contents   Strain 1: Staphylococcus aureus ATCC 6538P     Inoculation bacteria concentration (CFU / mL) 2.6 × 10 ⁵     Proliferation Rate (F)                  1.6       Ma 2.6 × 10 ⁵       Mb 1.1 × 10 ⁷       Mc               <10 (= less than 10)     Antibacterial Activity (S)-Reduction (%)               (6.2) 99.9     Nonionic Surfactant Type              TWEEN 80 (0.05%)

                      Test strain contents   Strain 2: Escherichia coli ATCC 8739     Inoculation bacteria concentration (CFU / mL) 2.5 × 10 ⁵     Proliferation Rate (F)                  1.7       Ma 2.5 × 10 ⁵       Mb 1.4 × 10 ⁷       Mc               <10 (= less than 10)     Antibacterial Activity (S)-Reduction (%)               (6.2) 99.9     Nonionic Surfactant Type              TWEEN 80 (0.05%)

CFU = Colony Forming Unit

As shown in Table 3 as a result of the above test 3, in the case of applying the resin coating material mixed with the epoxy paint and the diluent in a concentration of 50ppm silver (Ag) nanoparticles of 1 to 20nm size according to the present invention As the test strains were reduced by 99.9% and 99.9%, respectively, strains 1 (yellow staphylococcus aureus) and strain 2 (coliform bacillus) were found to exhibit complete antibacterial activity.

Meanwhile, the present invention is not limited to the above-described application examples, and various changes and modifications can be made within the scope not departing from the technical gist and gist of the invention.

That is, although the present invention has been described in the case where the present invention is applied to a water pipe, the present invention is not necessarily limited to a metal water pipe.

Figure 1a is an atomic force microscope image photograph of the surface roughness of the coating of the inner wall surface of the steel pipe for water by the resin coating agent, except for the nano-silver (silver (Ag) nanoparticles) and the epoxy paint and the diluent is mixed according to the present invention ( Average roughness 0.282 μm),

Figure 1b is a diagram showing measurement data showing the surface roughness of the atomic force microscope image photograph shown in Figure 1a,

Figure 2a is an atomic force microscope image photograph of the surface of the inner wall of the water pipes by coating the resin coating agent, except for the nano-silver (silver (Ag) nanoparticles) and the epoxy paint and the diluent is mixed according to the present invention ( Average roughness 0.114 μm),

FIG. 2B is a diagram schematically showing measurement data showing surface roughness of the AFM image photograph shown in FIG. 2A;

3 is a TEM (Transmission Electronic Microscope) photograph showing a state in which a nano silver having an average particle size of 7 nm is distributed on an inner wall surface of a water pipe according to the present invention.

Claims (5)

In the metal water supply pipe for supplying water (water, sewage, agricultural water, industrial water), On the inner wall surface of the steel pipe for water is coated with a resin coating agent mixed with an epoxy paint, a diluent and a thinner to form a resin coating layer, By adding and mixing nano silver (silver (Ag) nanoparticles) to the resin coating agent to coat the inner wall surface of the steel pipe for water to have an antimicrobial force on the inner wall surface of the steel pipe for water and at the same time rough surface of the inner wall surface of the steel pipe for water Method of producing a steel pipe for water having antibacterial and antifouling properties, characterized in that to be reduced. The method of claim 1, wherein the silver (Ag) nanoparticles added to the resin coating agent has a particle size of 1 ~ 20nm, the concentration is added 0.001 ~ 0.05% (10 ~ 10% by weight of the mixture of the epoxy paint and diluent) Method of producing a steel pipe for water having antibacterial and antifouling properties, characterized in that (500ppm). The method of claim 1, wherein the silver (Ag) nanoparticles are selected from a metal salt and a raw material of silver nitrate, silver chloride, silver acetate as a metal salt and compound. One of a kind selected from one material, one that is physically small to crush silver particles (Ag), and one that is prepared by sintering silver (Ag) in a wire state and then pulverizing it by electrical explosion The method for producing a water pipe having antibacterial and antifouling properties, characterized in that the nanoparticles are mixed with a resin coating agent consisting of the epoxy paint and the diluent. According to claim 3, The silver (Ag) nanoparticles obtained through the dispersion and stabilization of silver (Ag) nanoparticles from the metal salt and compound containing silver (Ag) is a surfactant as the acceptor and the silver (Ag) Obtained by extracting silver (Ag) of the metal by dissociating and ion-reducing the metal salt and the compound containing the A metal salt and a compound containing silver (Ag) are dissociated and ion-reduced to extract silver (Ag) of the metal, and stabilized by using one selected from silica, zeolite and zirconium phosphate as a carrier, After the silicon oxide is coated and mixed on the surface of the silver nanoparticles to disperse and stabilize, the metal salt and compound containing silver (Ag) are mixed with a polymer stabilizer, dissolved in a solvent, and purged with nitrogen. Method for producing a water steel pipe having antibacterial and antifouling properties, characterized in that it comprises one prepared by irradiation with gamma rays. According to claim 3, When the silver (Ag) nanoparticles are prepared in the colloidal phase, the solvent used is isopropyl alcohol (isopropyl alcohol), methyl ethyl ketone (methyl ethyl ketone), toluene (toluene) any one Or a method for producing a steel pipe for water having antibacterial and antifouling properties characterized in that two or more are mixed.

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