Long-acting antibacterial silver ion coating and preparation method thereof

Abstract

The application relates to a long-acting antibacterial silver ion coating and a preparation method thereof. The long-acting antibacterial silver ion coating comprises the following components in parts by weight: 20-45 parts of an epoxy resin, 20-45 parts of a polyester resin, 1-1.5 parts of a leveling agent, 3-8 parts of an antibacterial agent and 15-35 parts of pigments and fillers; the antibacterial agent is modified porous carbon loaded with silver ions. The scheme provided by the application can enhance the adhesion and stability of silver ions, make the coating have higher environmental resistance, achieve long-acting antibacterial function, meet the demand of consumers for antibacterial coatings, and solve the problem that traditional silver ion antibacterial agents easily cause discoloration of paint films.

Description

Technical Field

[0001] This application relates to the field of coating technology, and in particular to a long-lasting antibacterial silver ion coating and its preparation method. Background Technology

[0002] Paint is a widely used material in construction, industry, and home decoration. It not only protects the surface of objects but also serves a decorative purpose. There are many types of paint, which can be divided into water-based paints, oil-based paints, powder coatings, etc., according to their composition and uses. They can provide different colors, glosses, and textures to meet diverse aesthetic and functional needs.

[0003] With societal development, antibacterial requirements exist in many areas, including daily life, buildings, ships, and circulating cooling water systems. Therefore, adding specific antibacterial components to coatings to inhibit microbial growth and reproduction, thus achieving an antibacterial effect, results in antibacterial coatings. Antibacterial coatings are mainly classified into three categories: natural antibacterial coatings, organic antibacterial coatings, and inorganic antibacterial coatings. Natural antibacterial coatings primarily utilize chitosan and natural plant extracts as antibacterial materials; however, their application is greatly limited due to issues such as source, extraction level, cost, and stability. Organic antibacterial coatings mainly include isothiazolinones, formaldehyde releasers, and organic amines. While they offer significant short-term antibacterial effects and strong resistance to discoloration, they suffer from poor heat resistance, easy decomposition, short lifespan, and some even have toxic side effects, further limiting their application. Inorganic antibacterial coatings primarily utilize the bactericidal or bacteriostatic abilities of metals such as silver, copper, and zinc, and their ions, to disrupt bacterial structures. They feature high-efficiency sterilization, long-lasting effects, and no drug resistance, making them one of the main directions for the development of the antibacterial coating industry.

[0004] Antibacterial agents such as silver ions added to inorganic antibacterial coatings have a good bactericidal effect, but the drawback is that silver ions are chemically active and sensitive to light and heat. In particular, they are easily reduced to black elemental silver when exposed to ultraviolet light, which affects the appearance of white or light-colored coatings and limits their application. Summary of the Invention

[0005] To address or partially address the problems existing in related technologies, this application provides a long-lasting antibacterial silver ion coating and its preparation method, which can enhance the adhesion and stability of silver ions, making the coating more resistant to the environment, achieving long-lasting antibacterial function, and meeting consumers' demand for antibacterial coatings; at the same time, it can solve the problem that traditional silver ion antibacterial agents easily cause discoloration of the paint film.

[0006] The first aspect of this application provides a long-lasting antibacterial silver ion coating, comprising the following components in parts by weight: 20-45 parts epoxy resin, 20-45 parts polyester resin, 1-1.5 parts leveling agent, 3-8 parts antibacterial agent, and 15-35 parts pigments and fillers.

[0007] The antibacterial agent is modified porous carbon loaded with silver ions.

[0008] In some embodiments of this application, the method for preparing the antibacterial agent includes:

[0009] 1) Dissolve 2-aminoterephthalic acid and titanium tetrachloride in anhydrous ethanol, mix them evenly under high temperature conditions, and then filter to obtain a titanium metal organic framework.

[0010] 2) The titanium metal-organic framework is pyrolyzed under a protective atmosphere, washed with ethanol, and dried to obtain porous carbon;

[0011] 3) Mix porous carbon with silver nitrate solution, filter after reaction, dry and grind to obtain modified porous carbon loaded with silver ions.

[0012] In some embodiments of this application, the mass ratio of 2-aminoterephthalic acid and titanium tetrachloride in step 1) is (1-3):1, and the mixing temperature is 100-125°C.

[0013] In some embodiments of this application, in step 1), 2-aminoterephthalic acid and titanium tetrachloride are dissolved in anhydrous ethanol and then subjected to ultrasonic treatment for 12-25 minutes at an ultrasonic frequency of 10-30 kHz.

[0014] In some embodiments of this application, the pyrolysis temperature in step 2) is 1000-1200°C.

[0015] In some embodiments of this application, the concentration of silver nitrate solution in step 3) is 0.15-0.25 mol / L, the solid-liquid ratio of porous carbon to silver nitrate solution is 0.8-1.2 g / 10 mL, and the reaction time is 2-3 hours.

[0016] In some embodiments of this application, in step 3), the modified porous carbon loaded with silver ions is ground to pass through a 300-mesh sieve.

[0017] In some embodiments of this application, the epoxy equivalent of the epoxy resin is 750-900 g / mol.

[0018] In some embodiments of this application, the pigments and fillers are a mixture of titanium dioxide, barium sulfate, and zirconium phosphate.

[0019] The second aspect of this application provides a method for preparing a long-lasting antibacterial silver ion coating, wherein epoxy resin, polyester resin, leveling agent, antibacterial agent, pigments and fillers as described in the first aspect of this application are mixed in parts by weight and then extruded, ball-milled and sieved to obtain an antibacterial silver ion powder coating.

[0020] The technical solution provided in this application may include the following beneficial effects: by using an antibacterial agent in combination with epoxy resin and polyester resin, the antibacterial agent can be uniformly dispersed in the cross-linked network structure formed by epoxy resin and polyester resin, thereby utilizing the cross-linked network structure formed by epoxy resin and polyester resin to encapsulate the porous carbon structure loaded with silver ions. The cross-linking effect of epoxy resin and polyester resin works together with the porous carbon structure to reduce the influence of light and heat on the release of silver ions, avoid the excessively rapid dissolution of silver ions, and achieve a long-lasting antibacterial effect; at the same time, it reduces the probability of oxidation and discoloration of silver ions and improves the anti-discoloration ability of the coating film.

[0021] Furthermore, the antibacterial agent of this application has a porous carbon structure loaded with titanium dioxide, and its porosity and stability are increased after pyrolysis. It has good silver ion adsorption and fixation effects. The synergistic effect of titanium dioxide and silver ions can enable less antibacterial agent to exert better antibacterial and bactericidal effects. In the early stage of film formation, silver ions and titanium dioxide can release active oxygen, thereby exerting good early antibacterial properties and long-term antibacterial properties. At the same time, it can also act as a whitening filler, further improving the weather resistance and anti-discoloration ability of the coating film.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Detailed Implementation

[0023] To facilitate understanding of the present invention, it will be described in detail below. However, before describing the present invention in detail, it should be understood that the present invention is not limited to the specific embodiments described. It should also be understood that the terminology used herein is for describing specific embodiments only and is not intended to be restrictive.

[0024] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0025] Where numerical ranges are provided, it should be understood that every intermediate value between the upper and lower limits of the range and any other specified or intermediate value within the specified range is covered within the present invention. The upper and lower limits of these smaller ranges may be independently included in the smaller range and are also covered within the present invention, subject to any explicitly excluded limits within the specified range. Where a specified range includes one or two limits, the range excluding any or both of those included limits is also included within the present invention. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While any methods and materials, or equivalents thereof, may be used in the practice or testing of this invention, preferred methods and materials are now described.

[0027] Antibacterial agents such as silver ions added to inorganic antibacterial coatings have a good bactericidal effect, but the drawback is that silver ions are chemically active and sensitive to light and heat. In particular, they are easily reduced to black elemental silver when exposed to ultraviolet light, which affects the appearance of white or light-colored coatings and limits their application.

[0028] To address the aforementioned issues, this application provides a long-lasting antibacterial silver ion coating and its preparation method, which enhances the adhesion and stability of silver ions, making the coating more resistant to the environment and achieving long-lasting antibacterial function, thus meeting consumers' demand for antibacterial coatings; at the same time, it can solve the common problem of traditional silver ion antibacterial agents causing discoloration of the paint film.

[0029] The long-lasting antibacterial silver ion coating of this application embodiment includes the following components in parts by weight: 20-45 parts epoxy resin, 20-45 parts polyester resin, 1-1.5 parts leveling agent, 3-8 parts antibacterial agent, and 15-35 parts pigments and fillers; wherein the antibacterial agent is modified porous carbon loaded with silver ions.

[0030] In one specific embodiment, the epoxy resin is selected as a bisphenol A type epoxy resin with an epoxy equivalent of 750-900 g / mol. In this embodiment, selecting an epoxy resin with the above-mentioned epoxy equivalent ensures that the curing efficiency is maintained while maintaining its flow properties, thus ensuring that the coating has good application performance; moreover, its high crosslinking density and stable network structure help improve the adhesion strength and thermal stability of the coating.

[0031] The polyester resin is selected from one or more of UR-3500, UR1350, and UR-1400 resins, or a combination thereof.

[0032] In one specific embodiment, the mass ratio of epoxy resin to polyester resin is 1:1. Using epoxy resin and polyester resin as the base resins for the powder coating, and with the polyester resin containing amine groups, which can act as a curing agent for the epoxy resin, reacting with the epoxy groups in the epoxy resin, avoids the need for additional curing agents such as amine curing agents and organic acid glycoside curing agents. This improves the curing speed and crosslinking density of the coating, while avoiding environmental and health hazards, and problems such as yellowing of the coating. Furthermore, adjusting the ratio of epoxy resin to polyester resin helps to accelerate the curing of the coating, while also enhancing the toughness and impact strength of the coating.

[0033] The leveling agent should be one or a combination of BYK330, BYK364, BYK3932, and BYK3902. Choosing these leveling agents can effectively adjust the surface properties of the coating, provide good leveling effects, and ensure good application performance. It can also reduce defects such as pinholes, fisheyes, and graininess, and improve the smoothness and gloss of the coating.

[0034] In one specific embodiment, the antibacterial agent is modified porous carbon loaded with silver ions. The porous carbon structure has a large specific surface area and high porosity, which is beneficial for adsorbing silver ions. This allows the antibacterial agent to have long-lasting antibacterial properties when applied to coatings. Furthermore, because the modified porous carbon aggregates and adsorbs silver ions to a certain extent, the silver ion distribution throughout the coating is uniform. This not only inhibits the dissolution of silver ions but also ensures their uniform release, avoiding uneven antibacterial performance after the coating film is formed.

[0035] Furthermore, due to the skeletal structure of porous carbon, when used in combination with epoxy resin and polyester resin, it can act as a supporting skeleton, improving the crack resistance and impact strength of the coating formed by epoxy resin and polyester resin. At the same time, porous carbon can be evenly distributed in the cross-linked network structure of epoxy resin and polyester resin, playing a filling and toughening role, improving the heat resistance, cold resistance, weather resistance and other properties of the coating, improving the problem of easy discoloration of the coating when exposed to ultraviolet radiation, maintaining the antibacterial properties and anti-discoloration ability of the coating, which is beneficial for the application of this coating on light-colored objects.

[0036] In one specific embodiment, the amount of antibacterial agent is 5%-8% of the total mass of epoxy resin and polyester resin; preferably 6%. By adjusting the amount of antibacterial agent, the coating film's crack resistance and stability can be enhanced while ensuring sufficient adhesion. If the amount of antibacterial agent is too low, it will be difficult to enhance the crack resistance, stability, and antibacterial properties; if the amount of antibacterial agent is too high, it will easily affect the viscosity.

[0037] In one specific embodiment, the antibacterial agent is prepared using the following method:

[0038] 1) Dissolve 2-aminoterephthalic acid and titanium tetrachloride in anhydrous ethanol, mix them evenly under high temperature conditions, and then filter to obtain a titanium metal organic framework.

[0039] 2) The titanium metal-organic framework is pyrolyzed under a protective atmosphere, washed with ethanol, and dried to obtain porous carbon;

[0040] 3) Mix porous carbon with silver nitrate solution, filter after reaction, dry and grind to obtain modified porous carbon loaded with silver ions.

[0041] The titanium-organic framework prepared by 2-aminoterephthalic acid and titanium tetrachloride has a polyhedral three-dimensional framework structure. The presence of the titanium metal network structure can improve the thermal stability and light resistance of the porous carbon structure, and increase the ion exchange rate, which is beneficial to the adsorption and fixation of silver ions, thereby improving the bactericidal and antibacterial effect and duration of the coating. Moreover, the porous carbon structure formed after further pyrolysis has high porosity, which allows silver ions to be evenly distributed in the porous structure. The high pore structure complexity makes it difficult for external oxygen to directly contact the silver ions in the pores, thereby avoiding excessively rapid dissolution of silver ions and deactivation, and maintaining the long-lasting antibacterial effect of the coating. Furthermore, when the antibacterial agent is used in combination with epoxy resin and polyester resin, the antibacterial agent can be uniformly dispersed in the network structure formed by epoxy resin and polyester resin. The cross-linked network structure formed by epoxy resin and polyester resin can then encapsulate the porous carbon structure. The cross-linking effect of epoxy resin and polyester resin makes it difficult for the gaps in the porous carbon structure to expand or change. Working together with the porous carbon structure, it reduces the influence of light and heat on the release of silver ions, avoids the excessive dissolution of silver ions, and achieves a long-lasting antibacterial effect.

[0042] Moreover, due to the increased porosity of the porous carbon structure after pyrolysis, the silver ion adsorption and fixation effect is good, which enables less antibacterial agent to exert a higher antibacterial and bactericidal effect. In addition, silver ions can be released in the early stage of film formation, which can exert good early antibacterial performance and long-term antibacterial performance.

[0043] In step 1), the mass ratio of 2-aminoterephthalic acid to titanium tetrachloride is (1-3):1, for example, it can be 1:1, 2:1, or 3:1, preferably 1:1. In step 1), the mixing temperature of 2-aminoterephthalic acid and titanium tetrachloride is 100-125℃, for example, 100℃, 110℃, 115℃, 120℃, or 125℃.

[0044] In step 1), 2-aminoterephthalic acid and titanium tetrachloride are dissolved in anhydrous ethanol and then subjected to ultrasonic treatment for 12-25 minutes at an ultrasonic frequency of 10-30 kHz.

[0045] Specifically, step 1) can be to dissolve 2-aminoterephthalic acid and titanium tetrachloride in anhydrous ethanol at a mass ratio of 1:1, sonicate the dissolved mixture for 14-18 min, and then place it in a high temperature environment of 100-125℃ for 36-48 hours to continue mixing. The resulting reaction mixture is cooled and filtered, the precipitate is washed with ethanol, filtered and separated, and then dried at 70℃ to obtain the titanium metal organic framework.

[0046] The prepared titanium-containing organic framework not only has high structural strength, but also good heat and light stability. When used in powder coatings, its color is not easily affected by factors such as light and heat.

[0047] In step 2), the pyrolysis temperature of the titanium metal-organic framework is 1000-1200℃, for example, 1000℃, 1100℃, 1200℃, etc. The protective atmosphere can be nitrogen, helium, etc.

[0048] Specifically, step 2) can be to carry out a pyrolysis reaction of titanium metal-organic framework under a nitrogen protective atmosphere. First, maintain the environment at 1000℃ for 1 hour, and then increase the temperature by 100℃ every hour until the reaction is carried out at 1200℃ for 2 hours. After the reaction product is taken out and cooled to room temperature, it is washed with ethanol to remove pores, and then vacuum dried at 70℃ to obtain a titanium dioxide supported nanoporous carbon structure.

[0049] In step 3), the concentration of the silver nitrate solution is 0.15-0.25 mol / L, such as 0.15 mol / L, 0.20 mol / L, 0.25 mol / L, etc., preferably 0.25 mol / L.

[0050] In step 3), the solid-liquid ratio of porous carbon to silver nitrate solution is 0.8-1.2 g / 10 mL, and the reaction time is 2-3 hours.

[0051] In step 3), the modified porous carbon loaded with silver ions is ground to pass through a 300-mesh sieve.

[0052] Specifically, step 3) can be to react porous carbon with a silver nitrate solution with a concentration of 0.15-0.25 mol / L, at a reaction temperature of 60-80℃, a solid-liquid ratio of 0.8-1.2 g / 10 mL, and a reaction time of 2-3 hours. After the reaction is completed, the carbon is washed with ethanol, filtered, dried at 70℃, and then ground to pass through a 300-mesh sieve. The modified porous carbon framework exhibits high silver ion adsorption rate after reaction and can maintain its antibacterial properties for a long time after the coating film is formed. Moreover, since the porous carbon structure is an organometallic framework loaded with titanium dioxide, titanium dioxide not only acts as a whitening filler to prevent the coating from yellowing and discoloring rapidly, thus improving the coating's resistance to discoloration, but also generates reactive oxygen species under light. The oxidizing power of reactive oxygen species can destroy the cell walls of bacteria and the envelopes of viruses, thereby achieving a bactericidal effect. When loaded with silver ions, it has a synergistic effect, greatly enhancing the bactericidal effect of the coating and maintaining it for a long time, giving the coating long-lasting bactericidal performance. Furthermore, by utilizing the combined action of the titanium dioxide organometallic framework and silver ions, the amount of silver ions used can be reduced, lowering the production costs of antibacterial agents and coatings, making it suitable for large-scale use.

[0053] In one specific embodiment, the pigment / filler is a mixture of titanium dioxide, barium sulfate, and zirconium phosphate. Further, the mass ratio of titanium dioxide, barium sulfate, and zirconium phosphate is 1:1:1. Using a mixture of titanium dioxide, barium sulfate, and zirconium phosphate as a pigment / filler not only effectively functions as a whitening filler, facilitating its application in coatings on white or light-colored surfaces, but also, the three-dimensional crystalline and layered structure of the pigment / filler, when filled into the network structure formed by the crosslinking of epoxy and polyester resins, increases the complexity of ion exchange channels, which helps reduce the dissolution rate of silver ions, allowing the antibacterial agent to exert a better and longer-lasting antibacterial and bactericidal effect.

[0054] This application also provides a method for preparing a long-lasting antibacterial silver ion coating, comprising:

[0055] An antibacterial silver ion powder coating is prepared by mixing epoxy resin, polyester resin, leveling agent, antibacterial agent, pigments and fillers in a certain weight ratio, followed by extrusion, ball milling and sieving.

[0056] Specifically, epoxy resin, polyester resin, leveling agent, antibacterial agent, pigments and fillers can be mixed in a certain weight ratio at 600℃ for 15 minutes and then melt-extruded. The mixture is then ball-milled in a ball mill at 1500 rpm and passed through a 200-mesh sieve to obtain an antibacterial silver ion powder coating.

[0057] To make the present invention easier to understand, the present application will be further described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and are not limited to the scope of application of the present application. Unless otherwise specified, the raw materials or components used in the present application can be obtained commercially or by conventional methods.

[0058] Example 1

[0059] 30 parts of epoxy resin (epoxy equivalent 900 g / mol), 45 parts of polyester resin (UR-3500), 1.5 parts of leveling agent BYK364, 3 parts of antibacterial agent, and 20.5 parts of pigment and filler (titanium dioxide) were mixed at 600℃ for 15 min and then melt-extruded. The mixture was then ball-milled in a ball mill at 1500 rpm and passed through a 200-mesh sieve to obtain an antibacterial silver ion powder coating.

[0060] The antibacterial agent is prepared using the following method:

[0061] (1) Dissolve 2-aminoterephthalic acid and titanium tetrachloride in anhydrous ethanol at a mass ratio of 1:1. Sonicate the dissolved mixture for 15 min, and then place it in a high temperature environment of 100-125℃ for 48 hours. Cool and filter the resulting reaction mixture, wash the precipitate with ethanol, filter and separate it, and dry it at 70℃ to obtain the titanium metal organic framework.

[0062] (2) The titanium metal-organic framework was pyrolyzed under a nitrogen protective atmosphere. First, it was kept at 1000℃ for 1 hour, and then the temperature was increased by 100℃ every hour until it was reacted at 1200℃ for 2 hours. The reaction product was taken out, cooled to room temperature, washed with ethanol to remove pores, and then vacuum dried at 70℃ to obtain the nanoporous carbon structure supported by titanium dioxide.

[0063] (3) The porous carbon was reacted with a silver nitrate solution with a concentration of 0.15-0.25 mol / L at a reaction temperature of 65℃, a solid-liquid ratio of 1.2 g / 10 mL, and a reaction time of 3 hours. After the reaction was completed, the carbon was washed with ethanol, filtered, dried at 70℃, and then ground to pass through a 300-mesh sieve.

[0064] Example 2

[0065] 45 parts of epoxy resin (epoxy equivalent 800 g / mol), 20 parts of polyester resin (UR-3500), 1.5 parts of leveling agent BYK364, 3 parts of antibacterial agent, and 30.5 parts of pigment and filler (titanium dioxide) were mixed at 600℃ for 15 min and then melt-extruded. The mixture was then ball-milled in a ball mill at 1500 rpm and passed through a 200-mesh sieve to obtain an antibacterial silver ion powder coating.

[0066] The antibacterial agent was prepared using the same method as the antibacterial agent in Example 1.

[0067] Example 3

[0068] 33 parts of epoxy resin (epoxy equivalent 900 g / mol), 33 parts of polyester resin (UR-3500), 1 part of leveling agent BYK364, 3 parts of antibacterial agent, and 30 parts of pigment and filler (titanium dioxide) were mixed at 600℃ for 15 min and then melt-extruded. The mixture was then ball-milled in a ball mill at 1500 rpm and passed through a 200-mesh sieve to obtain an antibacterial silver ion powder coating.

[0069] The antibacterial agent was prepared using the same method as the antibacterial agent in Example 1.

[0070] Example 4

[0071] 33 parts of epoxy resin (epoxy equivalent 900 g / mol), 33 parts of polyester resin (UR-3500), 1 part of leveling agent BYK364, 5 parts of antibacterial agent, and 28 parts of pigment and filler (titanium dioxide) were mixed at 600℃ for 15 min and then melt-extruded. The mixture was then ball-milled in a ball mill at 1500 rpm and passed through a 200-mesh sieve to obtain an antibacterial silver ion powder coating.

[0072] The antibacterial agent was prepared using the same method as the antibacterial agent in Example 1.

[0073] Example 5

[0074] 28 parts of epoxy resin (epoxy equivalent 900 g / mol), 28 parts of polyester resin (UR-3500), 1 part of leveling agent BYK364, 8 parts of antibacterial agent, and 35 parts of pigment and filler (titanium dioxide) were mixed at 600℃ for 15 min and then melt-extruded. The mixture was then ball-milled in a ball mill at 1500 rpm and passed through a 200-mesh sieve to obtain an antibacterial silver ion powder coating.

[0075] The antibacterial agent was prepared using the same method as the antibacterial agent in Example 1.

[0076] Example 6

[0077] 32 parts of epoxy resin (epoxy equivalent 900 g / mol), 32 parts of polyester resin (UR-3500), 1 part of leveling agent BYK364, 3.8 parts of antibacterial agent, and 31.2 parts of pigment and filler (titanium dioxide) were mixed at 600℃ for 15 min and then melt-extruded. The mixture was then ball-milled in a ball mill at 1500 rpm and passed through a 200-mesh sieve to obtain an antibacterial silver ion powder coating.

[0078] The antibacterial agent was prepared using the same method as the antibacterial agent in Example 1.

[0079] Example 7

[0080] 32 parts of epoxy resin (epoxy equivalent 900 g / mol), 32 parts of polyester resin (UR-3500), 1 part of leveling agent BYK364, 3.8 parts of antibacterial agent, and 31.2 parts of pigments and fillers (titanium dioxide, barium sulfate, and zirconium phosphate in a mass ratio of 1:1:1) were mixed at 600℃ for 15 min and then melt-extruded. The mixture was then ball-milled in a ball mill at 1500 rpm and passed through a 200-mesh sieve to obtain an antibacterial silver ion powder coating.

[0081] The antibacterial agent was prepared using the same method as the antibacterial agent in Example 1.

[0082] Example 8

[0083] The difference from Example 1 is that the preparation process of the antibacterial agent is as follows:

[0084] (1) Dissolve 2-aminoterephthalic acid and titanium tetrachloride in anhydrous ethanol at a mass ratio of 1:1. Sonicate the dissolved mixture for 15 min, and then place it in a high temperature environment of 100-125℃ for 48 hours. Cool and filter the resulting reaction mixture, wash the precipitate with ethanol, filter and separate it, and dry it at 70℃ to obtain the titanium metal organic framework.

[0085] (2) The titanium metal organic framework was reacted with silver nitrate solution with a concentration of 0.15-0.25 mol / L at a reaction temperature of 65℃, a solid-liquid ratio of 1.2 g / 10 mL, and a reaction time of 3 hours. After the reaction was completed, the mixture was washed with ethanol, filtered, dried at 70℃, and then ground to pass through a 300-mesh sieve.

[0086] Example 9

[0087] The difference from Example 1 is that the preparation process of the antibacterial agent is as follows:

[0088] (1) Dissolve 2-aminoterephthalic acid and aniline in anhydrous ethanol, sonicate the dissolved substance for 15 min, and then place it in a high temperature environment of 100-125℃ to continue the reaction for 48 hours. Cool and filter the obtained reaction mixture, wash the precipitate with ethanol, filter and separate it, and dry it at 70℃ to obtain the organic framework.

[0089] (2) The organic framework was pyrolyzed under a nitrogen protective atmosphere. First, it was kept at 1000℃ for 1 hour, and then the temperature was increased by 100℃ every hour until it was reacted at 1200℃ for 2 hours. The reaction product was taken out, cooled to room temperature, washed with ethanol to remove pores, and then vacuum dried at 70℃ to obtain a nanoporous carbon structure.

[0090] (3) The porous carbon was reacted with a silver nitrate solution with a concentration of 0.15-0.25 mol / L at a reaction temperature of 65℃, a solid-liquid ratio of 1.2 g / 10 mL, and a reaction time of 3 hours. After the reaction was completed, the carbon was washed with ethanol, filtered, dried at 70℃, and then ground to pass through a 300-mesh sieve.

[0091] Example 10

[0092] The difference from Example 1 is that the epoxy equivalent of the epoxy resin is 2000 g / mol.

[0093] Comparative Example 1

[0094] The difference from Example 1 is that the preparation process of the antibacterial agent is as follows:

[0095] Zeolite was reacted with a silver nitrate solution with a concentration of 0.15-0.25 mol / L at a reaction temperature of 65℃, a solid-liquid ratio of 1.2 g / 10 mL, and a reaction time of 3 hours. After the reaction was completed, the solution was washed with ethanol, filtered, dried at 70℃, and then ground to pass through a 300-mesh sieve to obtain an antibacterial agent.

[0096] Comparative Example 2

[0097] The difference from Example 1 is that the antibacterial agent used is commercially available nano silver powder (CAS No.: 7440-22-4).

[0098] The antibacterial coatings obtained in Examples 1-10 and Comparative Examples 1-2 were sprayed onto stainless steel plates using electrostatic spraying. After drying, a dry film with a thickness of 80 μm was prepared. The antibacterial performance and antibacterial durability were tested in accordance with GB / T 21866-2008 "Determination of Antibacterial Properties and Antibacterial Effects of Antibacterial Coatings (Films)". The test results are recorded in Table 1.

[0099] Table 1 Test Results

[0100]

[0101] As shown in Table 1, the antibacterial coatings provided in Examples 1-10 of this application achieve antibacterial activity against Staphylococcus aureus and Escherichia coli at a rate exceeding 99.00%, demonstrating excellent antibacterial performance. Furthermore, after 100 hours of UV irradiation, their antibacterial activity against Staphylococcus aureus and Escherichia coli reaches over 91.00%, meeting the standard for Class II antibacterial coatings. Moreover, the antibacterial agent prepared using the method described in the examples of this application, when used in antibacterial coatings, achieves over 95.00% antibacterial activity against Staphylococcus aureus and Escherichia coli after 100 hours of UV irradiation, meeting the standard for Class II antibacterial coatings and demonstrating excellent antibacterial durability.

[0102] The difference between Comparative Example 1 and Example 1 is that the antibacterial agent used is a zeolite-loaded silver ion antibacterial agent, which has an antibacterial activity of 95.20% and an antibacterial durability of 84.75% against Staphylococcus aureus, and an antibacterial activity of 94.85% and an antibacterial durability of 85.62% against Escherichia coli. Its antibacterial activity and antibacterial durability are far below the standard of Class I antibacterial coatings.

[0103] The difference between Comparative Example 2 and Example 2 is that the antibacterial agent used is commercially available nano silver powder, which has an antibacterial activity of 93.25% and an antibacterial durability of 83.45% against Staphylococcus aureus, and an antibacterial activity of 93.77% and an antibacterial durability of 82.28% against Escherichia coli. Its antibacterial activity and antibacterial durability are far below the standard of Class I antibacterial coatings.

[0104] The difference between Examples 8 and 9 and Example 1 is that the antibacterial agent in Example 8 was not subjected to pyrolysis treatment during preparation, and the antibacterial agent in Example 9 did not contain titanium during preparation. Therefore, their antibacterial properties and durability are slightly lower than those of Example 1, especially in terms of durability. In Example 8, the lack of pyrolysis treatment during preparation likely resulted in a lower silver ion loading compared to Example 1, making it more prone to dissolution and negatively impacting the coating's antibacterial durability. In Example 9, the absence of titanium in the carrier not only prevented it from functioning as a whitening agent but also reduced the structural stability of the antibacterial agent, making silver ions more susceptible to dissolution and further compromising the coating's antibacterial durability.

[0105] The difference between Example 10 and Example 1 is that the epoxy equivalent of the epoxy resin in Example 10 is too high, which reduces the stability of the cross-linked network structure and the viscosity. This is not only beneficial to the curing of the coating, but also detrimental to the long-term antibacterial properties of the coating film.

[0106] The difference between Example 7 and Example 1 is that the amount of antibacterial agent added is between 5% and 8% of the total mass of epoxy resin and polyester resin, and the mass ratio of epoxy resin to polyester resin is 1:1. In addition, the pigments and fillers used are a mixture of titanium dioxide, barium sulfate and zirconium phosphate in a mass ratio of 1:1:1. This not only improves the weather resistance of the coating film, making it less susceptible to discoloration or cracking due to environmental factors such as light and heat, but also facilitates the filling of the filler and the compounding of the antibacterial agent, which is conducive to further improving its antibacterial durability.

[0107] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A long-lasting antibacterial silver ion coating, characterized in that, It includes the following components in parts by weight: 20-45 parts epoxy resin, 20-45 parts polyester resin, 1-1.5 parts leveling agent, 3-8 parts antibacterial agent, and 15-35 parts pigments and fillers; The antibacterial agent is modified porous carbon loaded with silver ions; The method for preparing the antibacterial agent includes: 1) Dissolve 2-aminoterephthalic acid and titanium tetrachloride in anhydrous ethanol, mix them evenly under high temperature conditions, and then filter to obtain a titanium metal organic framework. 2) The titanium metal-organic framework is pyrolyzed under a protective atmosphere, washed with ethanol, and dried to obtain porous carbon; 3) Mix porous carbon with silver nitrate solution, filter after reaction, dry and grind to obtain modified porous carbon loaded with silver ions; The epoxy resin has an epoxy equivalent of 750-900 g / mol; the pigments and fillers are a mixture of titanium dioxide, barium sulfate and zirconium phosphate.

2. The long-lasting antibacterial silver ion coating according to claim 1, characterized in that: In step 1), the mass ratio of 2-aminoterephthalic acid to titanium tetrachloride is (1-3):1, and the mixing temperature is 100-125℃.

3. The long-lasting antibacterial silver ion coating according to claim 1, characterized in that: In step 1), 2-aminoterephthalic acid and titanium tetrachloride are dissolved in anhydrous ethanol and then subjected to ultrasonic treatment for 12-25 minutes at an ultrasonic frequency of 10-30 kHz.

4. The long-lasting antibacterial silver ion coating according to claim 1, characterized in that: In step 2), the pyrolysis temperature is 1000-1200℃.

5. The long-lasting antibacterial silver ion coating according to claim 1, characterized in that: In step 3), the concentration of silver nitrate solution is 0.15-0.25 mol / L, the solid-liquid ratio of porous carbon to silver nitrate solution is 0.8-1.2 g / 10 mL, and the reaction time is 2-3 hours.

6. The long-lasting antibacterial silver ion coating according to claim 1, characterized in that: In step 3), the modified porous carbon loaded with silver ions is ground to pass through a 300-mesh sieve.

7. A method for preparing a long-lasting antibacterial silver ion coating, characterized in that, An antibacterial silver ion powder coating is prepared by mixing epoxy resin, polyester resin, leveling agent, antibacterial agent, pigments and fillers as described in any one of claims 1-6 in parts by weight, followed by extrusion, ball milling and sieving.

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