Antibacterial environment-friendly color steel plate and manufacturing process thereof

Abstract

The invention relates to an antibacterial environment-friendly color steel plate and a manufacturing process thereof, and relates to the technical field of building materials, the antibacterial environment-friendly color steel plate comprises a metal base plate, a passivation layer is arranged on the surface of the metal base plate, the surface of the passivation layer is coated with an antibacterial coating, and the antibacterial coating adopts modified epoxy resin as a base material. The invention discloses an antibacterial coating, which is formed by doping nano-silver particles and a natural antibacterial plant extract, matching with a color pigment and an auxiliary agent in a specific proportion, and performing high-temperature curing, and the antibacterial coating is prepared from the following components in percentage by mass: 75-90% of modified epoxy resin, 0.1-0.5% of the natural antibacterial plant extract, 0.05-0.2% of the nano-silver particles, 5-10% of the color pigment, 5-10% of the auxiliary agent and the balance of water. The passivation layer is a chromium-free passivation layer; the nano-silver particles and the natural antibacterial plant extract are introduced, so that the antibacterial property of the color steel plate is enhanced, the adhesive force and weather resistance of the coating are improved through the modified epoxy resin, and the environmental protection requirement is met while the antibacterial durability problem is solved.

Description

Technical Field

[0001] The present application relates to the technical field of building materials, and in particular to an antibacterial and environmentally friendly color steel plate and a manufacturing process thereof. Background Art

[0002] Most of the color steel plates currently used in the market are made by coating the surface of metal substrates. Although they have good decorative and weather resistance, they generally lack antibacterial properties. They are prone to breed bacteria and mold in humid environments, affecting human health. There is still much room for improvement in antibacterial performance and environmental protection. In the prior art, although the existing color steel plates are rich in color and durable, the surface coating usually does not have antibacterial function, which makes them easy to become a breeding ground for bacteria under certain conditions. Especially when used in hospitals, food processing and other industries, the sanitary safety is questioned. Some manufacturers try to enhance the antibacterial properties of color steel plates by adding low-concentration silver ions, but such practices are often costly, and the release stability of silver ions is difficult to control, and the antibacterial effect is weakened after long-term use. In addition, harmful substances are discharged during the preparation process of traditional color steel plates, which is not conducive to environmental protection. Summary of the invention

[0003] The purpose of this application is to provide an antibacterial and environmentally friendly color steel plate and its manufacturing process.

[0004] In the first aspect, the present application provides an antibacterial and environmentally friendly color steel plate adopts the following technical solution: An antibacterial and environmentally friendly color steel plate, an antibacterial and environmentally friendly color steel plate, comprising a metal substrate, a passivation layer is arranged on the surface of the metal substrate, an antibacterial coating is coated on the surface of the passivation layer, the antibacterial coating adopts modified epoxy resin as a base material, doped with nano silver particles and natural antibacterial plant extracts, combined with color pigments and additives in a specific proportion, and cured at high temperature, the antibacterial coating is composed of the following components according to the mass percentage of each component: modified epoxy resin 75%-90%, natural antibacterial plant extracts 0.1%-0.5%, nano silver particles 0.05%-0.2%, color pigments 5%-10%, additives 5%-10%, and the balance is water, and the passivation layer is a chromium-free passivation layer.

[0005] By adopting the above technical scheme, the metal substrate 1 is the base material of the environmentally friendly color steel plate, and the corrosion resistance of the metal substrate is improved by the passivation layer 2. By introducing nano-silver particles and natural antibacterial plant extracts, not only the antibacterial properties of the color steel plate are enhanced, but also the adhesion and weather resistance of the coating are improved by modifying the epoxy resin, which solves the problem of antibacterial durability while taking into account environmental protection needs. The chromium-free passivation layer is a dense oxide film formed on the metal surface, and its main purpose is to improve the corrosion resistance of the metal. Unlike traditional chromate passivation, the chromium-free passivation layer does not contain harmful chromium ions and is therefore more environmentally friendly.

[0006] Modified epoxy resin 78%-88%, natural antibacterial plant extract 0.15%-0.45%, nano silver particles 0.08%-0.18%, color pigment 6%-9%, additive 6%-9%, and the balance is water.

[0007] By adopting the above technical solution, when the percentage of the antibacterial coating components changes, it will directly affect the antibacterial and durable effects. The effect of gradually increasing or decreasing the content of a single component on the effect of the composition is not linear. When the above percentage is selected, the antibacterial coating has better antibacterial and durable effects.

[0008] Modified epoxy resin 80%-85%, natural antibacterial plant extract 0.2%-0.4%, nano silver particles 0.1%-0.15%, color pigment 7%-8%, additive 7%-8%, and the balance is water.

[0009] By adopting the above technical solution, after a large number of experiments and explorations, it was found that when modified epoxy resin, natural antibacterial plant extracts, nanosilver particles, color pigments and additives are selected in the above percentages, the antibacterial coating has better antibacterial and durable effects.

[0010] The natural antibacterial plant extract is extracted by steam distillation or ultrasound-assisted extraction. The nanosilver particles are prepared by methods including but not limited to laser ablation, electron beam evaporation and high-energy ball milling. The particle size of the nanosilver particles is preferably controlled between 10 nm and 30 nm.

[0011] By adopting the above technical scheme, natural plant extracts have diversified antibacterial mechanisms and can cope with various complex microbial infections. Natural plant extracts are widely available and easy to regenerate, which is in line with the concept of sustainable development. Nanosilver particles can slowly release silver ions, which continue to play an antibacterial role in the environment surrounding cells. The release rate of silver ions depends on the size, shape, surface properties and surrounding conditions of the nanosilver particles. When the silver ions Ag on the surface of the nanosilver particles come into contact with the microbial cell membrane, the silver ions are firmly adsorbed on the cell membrane by Coulomb attraction because the cell membrane is negatively charged. The silver ions can penetrate the cell wall and enter the cell, react with the thiol-SH in the cell, coagulate the protein, and destroy the activity of the cell synthase, thereby causing the cell to lose its ability to divide and proliferate and die. In addition, silver ions can also destroy the electron transport system, respiratory system and material transport system of microorganisms. Nanosilver ions have excellent antibacterial properties and can effectively inhibit the growth and reproduction of microorganisms such as bacteria and fungi, thereby improving the hygienic safety and durability of steel plates.

[0012] The natural antibacterial plant extract is preferably sourced from tea tree oil or thyme essential oil.

[0013] By adopting the above technical solution, by introducing nanosilver particles and natural antibacterial plant extracts, not only the antibacterial properties of the color steel plate are enhanced, but also the adhesion and weather resistance of the coating are improved by modifying the epoxy resin, solving the problem of antibacterial durability while taking into account environmental protection needs.

[0014] The coating thickness of the antibacterial coating is 30 μm-50 μm.

[0015] By adopting the above technical solution, the antibacterial efficiency and safety are further improved through fine control of the particle size of nanosilver particles and the selection of antibacterial plant extracts. At the same time, the optimized coating thickness design ensures an effective balance between material performance and cost.

[0016] The metal substrate is a cold-rolled substrate, a hot-dip galvanized substrate or an electro-galvanized substrate.

[0017] By adopting the above technical solution, the metal substrate is a color steel plate substrate.

[0018] The color pigment includes but is not limited to one of polyester, high weather-resistant polyester and polyvinylidene fluoride materials.

[0019] By adopting the above technical solution, a rich color selection can be provided through color pigments, and the corrosion resistance and durability of the steel plate can also be enhanced.

[0020] The auxiliary agents include but are not limited to drying agents, toughening agents, emulsifiers, thickeners and pigment dispersants.

[0021] By adopting the above technical scheme, the additive of steel plate coating refers to a small amount of ingredients added to the coating formula to control or enhance the performance of the coating. The drying agent is a substance that can accelerate the drying of the coating, and promotes the absorption of oxygen and the polymerization of double bonds of the dry oil film, which can shorten the drying time of the oil film from several days to several hours. The construction is convenient and can prevent the stain and damage of the undried coating film. The plasticizer can increase the toughness of the coating after coating. Commonly used varieties include diethyl phthalate, dibutyl phthalate, dioctyl phthalate, etc. The emulsifier can make two immiscible liquids form a stable emulsion, improve the stability and construction performance of the coating, and the thickener can increase the viscosity of the coating and reduce its fluidity. The important purpose of using the thickener is to reduce the flow phenomenon after coating. The pigment dispersant is used to prevent the sedimentation or floating of the pigment, ensure the uniform distribution of the pigment in the coating, and improve the color stability and hiding power of the coating.

[0022] The manufacturing process of the antibacterial and environmentally friendly color steel plate comprises the following steps: Step 1: pickling the metal substrate, then immersing it in a chromium-free passivating agent for passivation to form a passivation layer, and drying the metal substrate with a hot air blower after passivation; Step 2: Mix the modified epoxy resin, nano silver particles, natural antibacterial plant extracts, color pigments and additives in a mixing tank in accordance with the percentages, and stir and mix them by a stirring device in the mixing tank for 5-10 minutes to fully mix them to form an antibacterial coating; Step 3: coating the mixed antibacterial coating on the pretreated surface of the metal substrate; Step 4: The metal substrate coated with the antibacterial coating enters the oven and is cured and dried at a temperature of 160℃-175℃ to form a color steel coating with antibacterial function.

[0023] In summary, the present application includes at least one of the following beneficial technical effects: 1. By introducing nano-silver particles and natural antibacterial plant extracts, not only the antibacterial properties of color-coated steel plates are enhanced, but also the adhesion and weather resistance of the coating are improved by modifying the epoxy resin, solving the problem of antibacterial durability while taking into account environmental protection needs. The antibacterial efficiency and safety are further improved by finely controlling the particle size of nano-silver particles and selecting the types of antibacterial plant extracts. At the same time, the optimized coating thickness design ensures an effective balance between material performance and cost; 2. By using environmentally friendly materials and improving production processes, the impact on the environment is reduced, which is in line with the concept of green building. By matching a specific proportion of modified epoxy resin and antibacterial ingredients, the physical properties of the coating are optimized, extending the service life of the color steel plate and reducing the maintenance frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application; Figure 2 It is a schematic diagram of the manufacturing process steps of an embodiment of the present application; Figure 3 It is a schematic diagram of the raw material ratio of the antibacterial coating of Examples 1-7 of the present application; Explanation of the accompanying drawings: 1. Metal substrate; 2. Passivation layer; 3. Antibacterial coating. DETAILED DESCRIPTION

[0025] The following is combined with Figure 1 - Attachment Figure 3 , further details of this application are given.

[0026] Embodiment 1: An antibacterial and environmentally friendly color steel plate comprises a metal substrate 1, a passivation layer 2 is arranged on the surface of the metal substrate, and an antibacterial coating 2 is coated on the surface of the passivation layer 2. The antibacterial coating 2 adopts modified epoxy resin as a base material, doped with nano silver particles and natural antibacterial plant extracts, and matched with color pigments and additives in a specific proportion, and is cured at high temperature. The antibacterial coating 3 can be specifically set according to the mass percentage of each component as follows: 84.5% of modified epoxy resin, 0.25% of natural antibacterial plant extracts, 0.15% of nano silver particles, 7.5% of color pigments, 7.5% of additives, and the balance is water. By introducing nano silver particles and natural antibacterial plant extracts, not only the antibacterial properties of the color steel plate are enhanced, but also the adhesion and weather resistance of the coating are improved by modifying the epoxy resin, solving the problem of antibacterial durability while taking into account environmental protection needs. The chromium-free passivation layer 2 is a dense oxide film formed on the metal surface, and its main purpose is to improve the corrosion resistance of the metal. Unlike traditional chromate passivation, the chromium-free passivation layer 2 does not contain harmful chromium ions and is therefore more environmentally friendly.

[0027] Natural antibacterial plant extracts are extracted by steam distillation or ultrasound-assisted extraction. Nanosilver particles are prepared by methods including but not limited to laser ablation, electron beam evaporation and high-energy ball milling. The particle size of nanosilver particles is preferably controlled between 10nm and 30nm. Natural plant extracts have diversified antibacterial mechanisms and can cope with various complex microbial infections. Natural plant extracts are widely available and easy to regenerate, which is in line with the concept of sustainable development. Nanosilver particles can slowly release silver ions, which continue to play an antibacterial role in the environment around cells. The release rate of silver ions depends on the size, shape, and surface properties of the nanosilver particles. The silver ions Ag on the surface of nanosilver particles come into contact with the cell membrane of microorganisms, and because the cell membrane is negatively charged, the silver ions are firmly adsorbed on the cell membrane by Coulomb attraction. The silver ions can penetrate the cell wall and enter the cell, react with the thiol-SH in the cell, coagulate the protein, destroy the activity of the cell synthase, and thus cause the cell to lose its ability to divide and proliferate and die. In addition, silver ions can also destroy the electron transport system, respiratory system and material transport system of microorganisms. Nanosilver ions have excellent antibacterial properties and can effectively inhibit the growth and reproduction of microorganisms such as bacteria and fungi, thereby improving the hygienic safety and durability of steel plates.

[0028] The source of natural antibacterial plant extracts is preferably tea tree oil or thyme essential oil. By introducing nanosilver particles and natural antibacterial plant extracts, not only the antibacterial properties of the color steel plate are enhanced, but also the adhesion and weather resistance of the coating are improved by modifying the epoxy resin, solving the problem of antibacterial durability while taking into account environmental protection needs.

[0029] The coating thickness of the antibacterial coating 3 is 30μm-50μm. The antibacterial efficiency and safety are further improved through the refined control of the particle size of nanosilver particles and the selection of antibacterial plant extracts. At the same time, the optimized coating thickness design ensures an effective balance between material performance and cost.

[0030] The metal substrate is a cold-rolled substrate, a hot-dip galvanized substrate or an electro-galvanized substrate, and the metal substrate 1 is a color steel plate substrate.

[0031] The color pigment includes but is not limited to one of polyester, high weather-resistant polyester and polyvinylidene fluoride materials. The color pigment can provide a rich color selection and can also enhance the corrosion resistance and durability of the steel plate.

[0032] Additives include but are not limited to drying agents, toughening agents, emulsifiers, thickeners and pigment dispersants. Additives for steel plate coatings refer to a small amount of ingredients added to the coating formula to control or enhance the performance of the coating. Driers are substances that can accelerate the drying of the coating, promote the absorption of oxygen and the polymerization of double bonds in the drying oil film, and can shorten the drying time of the oil film from several days to several hours. The construction is convenient and can prevent the stain and damage of the undried coating film. Plasticizers can increase the toughness of the coating after coating. Commonly used varieties include diethyl phthalate, dibutyl phthalate, dioctyl phthalate, etc. Emulsifiers can make two immiscible liquids form a stable emulsion, improve the stability and construction performance of the coating, and thickeners can increase the viscosity of the coating and reduce its fluidity. The important purpose of using thickeners is to reduce the flow phenomenon after coating. Pigment dispersants are used to prevent the sedimentation or floating of pigments, ensure the uniform distribution of pigments in the coating, and improve the color stability and hiding power of the coating.

[0033] A manufacturing process of an antibacterial and environmentally friendly color steel plate comprises the following steps: Step 1: pickling the metal substrate 1, then immersing it in a chromium-free passivating agent for passivation treatment to form a passivation layer 2, and drying the metal substrate 1 with a hot air blower after passivation; Step 2: Mix the modified epoxy resin, nanosilver particles, natural antibacterial plant extracts, color pigments and additives in a mixing tank in accordance with the percentages, and stir and mix them by a stirring device in the mixing tank for 5-10 minutes to fully mix them to form an antibacterial coating 2; Step 3: coating the mixed antibacterial coating 2 on the pretreated surface of the metal substrate 1; Step 4: The metal substrate 1 coated with the antibacterial coating 2 enters an oven and is cured and dried at a temperature of 160° C. to 180° C. to form a color steel coating with antibacterial function.

[0034] Example 2: According to the proportion of the basic scheme, the mass percentage of nanosilver particles is set to 0.1%, the mass percentage of natural antibacterial plant extract from tea tree oil is set to 0.3%, the rest of the formula is the same as Example 1, and the curing temperature is set to 170°C.

[0035] Example 3: Based on Example 2, the particle size of the nanosilver particles is optimized to 15 nm, the coating thickness is set to 40 μm, and the other parameters remain unchanged.

[0036] Example 4: This example is different from Example 1 in that thyme essential oil is selected to replace tea tree oil, with the same mass percentage of 0.3%, the coating thickness is increased to 45 μm, and the curing temperature is lowered to 165°C.

[0037] Example 5: This example is different from Example 1 in that the particle size of the nanosilver particles is refined to 20 nm, the coating thickness is fine-tuned to 42 μm, and the curing temperature is maintained at 170°C.

[0038] Example 6: On the basis of Example 4, a titanium dioxide photocatalyst, which is an intelligent responsive antibacterial ingredient, is added. Its content is 0.5% of the total weight of the coating. The antibacterial performance is activated when the light intensity is greater than a certain threshold. The remaining ingredients are the same as in Example 4. The addition of an intelligent responsive antibacterial ingredient allows the color steel plate to automatically adjust its antibacterial activity when the humidity or light changes to adapt to the sterilization needs under different environmental conditions.

[0039] Example 7: Based on Example 5, the waste color steel plate is crushed into powder, accounting for 10% of the total raw material, and mixed with fresh materials and sprayed on the metal substrate. The curing conditions are set according to the optimized Example 5.

[0040] The implementation principle of the embodiment of the present application is as follows: first, the metal substrate 1 is pickled, and then immersed in a chromium-free passivating agent for passivation treatment to form a passivation layer 2. The chromium-free passivation layer 2 is a dense oxide film formed on the metal surface. Its main purpose is to improve the corrosion resistance of the metal. Unlike traditional chromate passivation, the chromium-free passivation layer does not contain harmful chromium ions, so it is more environmentally friendly. After passivation, the metal substrate 1 is dried by a hot air blower, and the modified epoxy resin, nanosilver particles, natural antibacterial plant extracts, color pigments and additives are mixed in a stirring tank in turn according to percentages, and stirred and mixed by a stirring device in the stirring tank for 5-10 minutes to fully mix them to form an antibacterial coating 2. By introducing nanosilver particles and natural antibacterial plant extracts, not only the antibacterial properties of the color steel plate are enhanced, but also the adhesion and weather resistance of the coating are improved by modifying the epoxy resin, which solves the problem of antibacterial durability while taking into account environmental protection needs. By finely controlling the particle size of the nanosilver particles, Chemical control and the selection of antibacterial plant extracts further improve the antibacterial efficiency and safety. At the same time, the optimized coating thickness design ensures an effective balance between material performance and cost. The mixed antibacterial coating 2 is coated on the surface of the pretreated metal substrate 1. The metal substrate 1 coated with the antibacterial coating 2 enters the oven and is cured and dried at a temperature of 160°C-180°C to form a color steel coating with antibacterial function. The antibacterial coating 2 shown in the attached figure can ensure that the color steel plate still maintains a good appearance and antibacterial efficacy in harsh outdoor environments, significantly improves the long-term antibacterial performance of the color steel plate, and effectively inhibits the growth of common pathogenic microorganisms. By using environmentally friendly materials and improving production processes, the impact on the environment is reduced, which is in line with the concept of green building. The physical properties of the coating are optimized, the service life of the color steel plate is extended, the maintenance frequency is reduced, and the dual goals of cost savings and functional upgrades are achieved. The application of intelligent responsive antibacterial ingredients makes the material more adaptable and meets the needs of diverse application scenarios.

[0041] The embodiments of this specific implementation are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. The same components are represented by the same figure marks. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An antibacterial and environmentally friendly color steel plate, comprising a metal substrate (1), characterized in that: The surface of the metal substrate is provided with a passivation layer (2), and the surface of the passivation layer (2) is coated with an antibacterial coating (3). The antibacterial coating (2) uses a modified epoxy resin as a base material, is doped with nano silver particles and a natural antibacterial plant extract, and is mixed with a specific proportion of color pigments and additives, and is cured at high temperature. The antibacterial coating (3) is composed of the following components according to the mass percentage of each component: 75%-90% of modified epoxy resin, 0.1%-0.5% of natural antibacterial plant extract, 0.05%-0.2% of nano silver particles, 5%-10% of color pigments, 5%-10% of additives, and the balance is water. The passivation layer (2) is a chromium-free passivation layer.

2. The antibacterial and environmentally friendly colored steel plate according to claim 1, characterized in that: Modified epoxy resin 78%-88%, natural antibacterial plant extract 0.15%-0.45%, nano silver particles 0.08%-0.18%, color pigment 6%-9%, additive 6%-9%, and the balance is water.

3. The antibacterial and environmentally friendly colored steel plate according to claim 1, characterized in that: Modified epoxy resin 80%-85%, natural antibacterial plant extract 0.2%-0.4%, nano silver particles 0.1%-0.15%, color pigment 7%-8%, additive 7%-8%, and the balance is water.

4. The antibacterial and environmentally friendly colored steel plate according to claim 3, characterized in that: The natural antibacterial plant extract is extracted by steam distillation or ultrasound-assisted extraction. The nanosilver particles are prepared by one of the methods including but not limited to laser ablation, electron beam evaporation and high-energy ball milling. The particle size of the nanosilver particles is preferably controlled between 10nm and 30nm.

5. The antibacterial and environmentally friendly colored steel plate according to claim 3, characterized in that: The natural antibacterial plant extract is preferably sourced from tea tree oil or thyme essential oil.

6. The antibacterial and environmentally friendly colored steel plate according to claim 1, characterized in that: The coating thickness of the antibacterial coating (3) is 30 μm-50 μm.

7. The antibacterial and environmentally friendly colored steel plate according to claim 1, characterized in that: The metal substrate (1) is one of a cold-rolled substrate, a hot-dip galvanized substrate or an electro-galvanized substrate.

8. The antibacterial and environmentally friendly colored steel plate according to claim 3, characterized in that: The color pigment includes but is not limited to one of polyester, high weather-resistant polyester and polyvinylidene fluoride materials.

9. The antibacterial and environmentally friendly colored steel plate according to claim 3, characterized in that: The auxiliary agents include but are not limited to drying agents, toughening agents, emulsifiers, thickeners and pigment dispersants.

10. A process for manufacturing an antibacterial and environmentally friendly color steel plate, using the antibacterial and environmentally friendly color steel plate according to any one of claims 1 to 9, characterized in that: The manufacturing process of the antibacterial and environmentally friendly color steel plate comprises the following steps: Step 1: pickling the metal substrate (1), then immersing it in a chromium-free passivating agent for passivation treatment to form a passivation layer (2), and drying the metal substrate (1) with a hot air blower after passivation; Step 2: Mix the modified epoxy resin, nanosilver particles, natural antibacterial plant extracts, color pigments and additives in a mixing tank in accordance with the percentages, and stir and mix them by a stirring device in the mixing tank for 5-10 minutes to fully mix them to form an antibacterial coating (2); Step 3: coating the mixed antibacterial coating (2) on the surface of the pretreated metal substrate (1); Step 4: The metal substrate (1) coated with the antibacterial coating (2) enters an oven and is cured and dried at a temperature of 160° C. to form a color steel coating with antibacterial function.

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