Antibacterial repulpable functional paper coating and preparation method thereof

Abstract

The invention relates to the technical field of paper coatings, and discloses an antibacterial repulpable functional paper coating and a preparation method thereof, and the paper coating is formed by coating the surface of raw paper with a paper coating liquid; the paper coating liquid is prepared from the following raw materials: acrylic acid, 2-ethylhexyl acrylate, glycidyl methacrylate, hydroxyethyl methylacrylate, an antibacterial modified component, deionized water, azodiisobutyronitrile, a filler, a coalescing agent, a flatting agent and a defoaming agent; according to the antibacterial modified component, a polymeric intermediate containing guanidyl and a Schiff base structure is grafted to the surface of zinc oxide, and an organic-inorganic multi-synergistic antibacterial effect is generated in a matrix, so that the antibacterial property of a paper coating can be effectively improved with a small addition amount, and the antibacterial property of the paper coating is improved. The negative influence caused by poor antibacterial property of the paper coating is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of paper coatings, and in particular to an antibacterial repulpable functional paper coating and a preparation method thereof. Background Art

[0002] With the rapid economic growth and continuous technological advancement, environmental protection and resource recycling have become core issues in today's social development. People's increasing attention to environmental protection and resource recycling has made the recycling of various resource materials more and more important, such as paper, plastic, rubber, steel and metal products. Among them, paper is a material with a three-dimensional network structure made from plant fibers as the main raw material. It has the advantages of renewable sources, biodegradability, and easy recycling. It can be widely used in the production of packaging paper bags, cartons, paper cups, etc.

[0003] As we all know, paper products generally adopt the method of coating a layer of plastic coating on the surface of base paper to obtain barrier properties against water, oil, etc. At present, most of the paper products on the market are PE coating, but PE coated paper products have problems such as non-degradability, non-repulpability, and difficulty in recycling. The market has gradually replaced it. Due to the advantages of water-based coatings such as recyclability and repulpability, it has been used in paper coating. With the improvement of people's awareness of health and safety, the antibacterial properties of paper products have also received more and more attention. A large number of microorganisms are easily attached to the surface of ordinary paper products, which will not only affect the quality of paper products, but also have a negative impact on the health of consumers. This has greatly restricted the further application of paper products. Therefore, it is urgent to develop a paper coating with good antibacterial properties.

[0004] In the prior art, the patent with the announcement number CN115928501B discloses an antibacterial wrapping paper and a preparation method thereof, wherein the wrapping paper is composed of a wrapping base paper and a hydrophobic antibacterial coating on its surface, wherein the hydrophobic antibacterial coating is obtained by sizing the surface of an antibacterial coating liquid, and the antibacterial property of the coating is improved by adding a multi-effect antibacterial agent and nano zinc oxide to the antibacterial coating liquid, so that the prepared wrapping paper has good antibacterial property. Therefore, by adding optimized components in a targeted manner during the preparation process of the paper coating, the paper coating can be endowed with good antibacterial property. Summary of the invention

[0005] In order to solve the problems mentioned in the background technology, the object of the present invention is to provide an antibacterial repulpable functional paper coating and a preparation method thereof.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] The invention discloses an antibacterial repulpable functional paper coating, wherein the paper coating is formed by coating a paper coating liquid on the surface of base paper; the paper coating liquid comprises the following raw materials in parts by weight: 30 to 40 parts of acrylic acid, 15 to 25 parts of isooctyl acrylate, 10 to 20 parts of glycidyl methacrylate, 5 to 15 parts of hydroxyethyl methacrylate, 5 to 8 parts of antibacterial modified components, 40 to 60 parts of deionized water, 3 to 5 parts of azobisisobutyronitrile, 8 to 12 parts of filler, 1 to 2 parts of film-forming aid, 1 to 3 parts of leveling agent, and 2 to 3 parts of defoaming agent.

[0008] Furthermore, the preparation method of the antibacterial modified component comprises the following steps:

[0009] S1: 1,3-diaminoguanidine hydrochloride and dimethyl sulfoxide are mixed, poured into a reaction kettle, and stirred until a uniform solution is formed. Then, 4-hydroxyisophthalaldehyde is added under continuous nitrogen conditions. After the addition is completed, the temperature is raised to 50-55° C., stirred at this temperature for 4-9 hours, and the solvent is removed by rotary evaporation to obtain a polymer intermediate;

[0010] S2: Under nitrogen protection, zinc oxide and N-methylpyrrolidone are mixed, and after ultrasonic treatment, a dispersion is formed, 2-chloroacrylic acid and catalyst A are added to the dispersion, and the system temperature is raised to 90-110° C. under stirring conditions, and after heat preservation for 5-7 hours, the solid material is separated, and the modified zinc oxide is obtained after washing and drying.

[0011] S3: Ultrasonic dispersion of modified zinc oxide in N,N-dimethylformamide to form a uniform dispersion, nitrogen is introduced for deoxygenation, polymer intermediate and sodium carbonate solution are added to the dispersion, heating is started, and after the system temperature reaches 70-80°C, constant temperature stirring is performed for 8-12 hours, and then filtration is performed to collect the product, and the product is washed and dried to obtain an antibacterial modified component.

[0012] Furthermore, in step S2, the average particle size of the zinc oxide is 5 μm.

[0013] Furthermore, in step S2, the catalyst A is any one of tetrabutyl titanate, tetraethyl titanate or tetraisopropyl titanate.

[0014] Furthermore, in step S2, the mass ratio of zinc oxide to 2-chloroacrylic acid is 1:0.1-0.3.

[0015] Furthermore, in step S3, the mass fraction of the sodium carbonate solution is 5% to 30%.

[0016] It can be inferred that the principle of the above scheme is: in step S1, the amino group can react with the aldehyde group, and 1,3-diaminoguanidine hydrochloride and 4-hydroxyisophthalaldehyde are used as raw materials to undergo continuous Schiff base reaction with each other, and the molecular chain is continuously extended to eventually form a polymer intermediate having a guanidine group, a hydroxyl group and a Schiff base structure; in step S2, the hydroxyl group on the surface of zinc oxide is catalyzed by catalyst A to undergo an esterification reaction with the carboxyl group in the 2-chloroacrylic acid structure, thereby introducing a halogen functional group and an unsaturated olefin functional group on the surface of zinc oxide to obtain a modified zinc oxide; in step S3, the halogen functional group on the surface of the modified zinc oxide can undergo a substitution reaction with the hydroxyl group in the polymer intermediate structure under the action of a sodium carbonate solution, thereby grafting the polymer intermediate to the surface of zinc oxide to obtain an antibacterial modified component.

[0017] A method for preparing an antibacterial repulpable functional paper coating comprises the following steps:

[0018] Step 1: Add acrylic acid, isooctyl acrylate, glycidyl methacrylate, hydroxyethyl methacrylate, antibacterial modified components and deionized water into a reaction kettle, ultrasonically disperse until a uniform liquid is formed, fill with inert gas protection, add azobisisobutyronitrile to the liquid, turn on heating after the addition, control the temperature to 60-80°C, keep warm and stir for 1-3h to obtain an acrylic polymer emulsion;

[0019] Step 2: Add filler, film-forming aid, leveling agent and defoamer to the acrylic polymer emulsion, stir and mix at a rate of 400-600 r / min for 30-50 min, let stand to defoam, and discharge the material to obtain a paper coating liquid;

[0020] Step 3: Evenly apply the paper coating liquid on the surface of the base paper and cure it at room temperature for 2 to 4 hours to obtain the paper coating.

[0021] Furthermore, in step 1, during the ultrasonic dispersion, the ultrasonic frequency is 70 to 90 kHz.

[0022] Furthermore, in step 1, the inert gas is any one of argon, neon or helium.

[0023] Furthermore, in step 2, the filler is any one of talc, calcium carbonate or titanium dioxide; the film-forming aid is any one of propylene glycol, propylene glycol methyl ether or dipropylene glycol methyl ether; the leveling agent is any one of polybutyl acrylate or polyethyl acrylate; the defoaming agent is any one of dimethyl silicone oil or fatty alcohol polyoxyethylene ether.

[0024] Beneficial effects of the present invention:

[0025] (1) The present invention uses water-based acrylic coating as the base of the coating material, so that the prepared paper coating has the advantages of being recyclable and repulpable, which is in line with the development concept of environmental protection and resource recycling in today's society. In addition, the prepared antibacterial modified component is added to the base material, which effectively improves the antibacterial property of the paper coating, overcomes the problem of poor antibacterial property of ordinary paper products, and has broad application prospects.

[0026] (2) The present invention prepares an antibacterial modified component as an additive. Since the antibacterial modified component contains an unsaturated olefinic functional group, it can be cross-linked with the matrix during the polymerization of monomers such as acrylic acid, isooctyl acrylate, and glycidyl methacrylate, so that the molecular chains are intertwined and fused with each other, making the paper coating show higher density, while avoiding the precipitation of the antibacterial modified component, thereby maintaining long-term antibacterial properties. On the one hand, after organic modification, zinc oxide improves its dispersibility in the matrix, making it less likely to agglomerate during use, and because of its special photocatalytic antibacterial effect, it significantly enhances the antibacterial properties of the paper coating. On the other hand, the antibacterial modified component contains not only guanidine antibacterial agents but also Schiff base structures. Therefore, the dual antibacterial effects of the guanidine group and the Schiff base structure can be utilized to make the prepared paper coating have excellent antibacterial properties, which can work together with zinc oxide to produce an organic-inorganic multiple synergistic antibacterial effect, thereby achieving the goal of effectively improving the antibacterial properties of the paper coating with a relatively small addition amount, thereby avoiding the negative impact caused by the poor antibacterial properties of paper products.

[0027] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0029] Figure 1 This is an infrared spectrum test chart of the antibacterial modified component prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] 1. Preparation of antibacterial modified components

[0033] S1: 2 g of 1,3-diaminoguanidine hydrochloride and dimethyl sulfoxide were mixed, poured into a reaction kettle, and stirred until a uniform solution was formed. Then, 2.2 g of 4-hydroxyisophthalaldehyde was added under continuous nitrogen conditions. After the addition was completed, the temperature was raised to 52° C., stirred at this temperature for 6 h, and the solvent was removed by rotary evaporation to obtain a polymer intermediate;

[0034] S2: Under nitrogen protection, 5 g of zinc oxide and N-methylpyrrolidone were mixed and subjected to ultrasonic treatment to form a dispersion, and 1.2 g of 2-chloroacrylic acid and 0.05 g of tetrabutyl titanate were added to the dispersion. The system temperature was raised to 100°C under stirring conditions. After heat preservation for 6 hours, the solid material was separated, washed and dried to obtain modified zinc oxide;

[0035] S3: Ultrasonic disperse 4 g of modified zinc oxide in N, N-dimethylformamide to form a uniform dispersion, introduce nitrogen to deoxygenate, add 3.4 g of polymer intermediate and 0.1 g of 20% sodium carbonate solution to the dispersion, turn on the heating, and after the system temperature reaches 75°C, stir at a constant temperature for 10 hours, then filter and collect the product, wash and dry the product to obtain an antibacterial modified component.

[0036] The antibacterial modified components were analyzed by infrared spectroscopy using a Thermo Scientific Nicolet IS50 Fourier transform infrared spectrometer. Figure 1 As shown by Figure 1 It can be seen that in the infrared spectrum of the antibacterial modified component, 1735cm -1 The absorption peak of the ester group C=O appears at 3015cm -1 The absorption peak of the carbon-hydrogen bond in the carbon-carbon double bond appears at 1661 cm -1 The absorption peak of Schiff base C=N appears at 3055cm -1 The absorption peak of the carbon-hydrogen bond in the benzene ring appears at 1030cm -1 The absorption peak of ether bond COC appears at 3381 cm -1 The absorption peak of NH in the guanidine group appears at

[0037] 2. Preparation of paper coating

[0038] Step 1: 30g of acrylic acid, 15g of isooctyl acrylate, 10g of glycidyl methacrylate, 5g of hydroxyethyl methacrylate, 5g of antibacterial modified component and 40g of deionized water are added to a reactor, ultrasonically dispersed at an ultrasonic frequency of 70kHz to form a uniform liquid, filled with argon for protection, 3g of azobisisobutyronitrile is added to the liquid, and after the addition, heating is turned on, the temperature is controlled to 60°C, and the mixture is kept warm and stirred for 1 to 3 hours to obtain an acrylic polymer emulsion;

[0039] Step 2: Add 8g of talc, 1g of propylene glycol, 1g of polyethyl acrylate and 2g of dimethyl silicone oil to the acrylic polymer emulsion, stir and mix at a speed of 400r / min for 30min, let it stand for defoaming, and discharge the material to obtain a paper coating liquid;

[0040] Step 3: Evenly apply the paper coating liquid on the surface of the base paper and cure it at room temperature for 2 hours to obtain the paper coating.

[0041] Example 2

[0042] Preparation of paper coating

[0043] Step 1: 35g of acrylic acid, 20g of isooctyl acrylate, 15g of glycidyl methacrylate, 10g of hydroxyethyl methacrylate, 7g of antibacterial modified component and 50g of deionized water are added to a reactor, ultrasonically dispersed at an ultrasonic frequency of 80kHz to form a uniform liquid, filled with argon for protection, 4g of azobisisobutyronitrile is added to the liquid, and after the addition, heating is turned on, the temperature is controlled to 70°C, and the mixture is kept warm and stirred for 2h to obtain an acrylic polymer emulsion;

[0044] Step 2: Add 10g of talc, 1.5g of propylene glycol, 2g of polyethyl acrylate and 2.5g of dimethyl silicone oil to the acrylic polymer emulsion, stir and mix at a speed of 500r / min for 40min, let it stand for defoaming, and discharge the material to obtain a paper coating liquid;

[0045] Step 3: Evenly apply the paper coating liquid on the surface of the base paper and cure it at room temperature for 3 hours to obtain the paper coating.

[0046] The preparation method of the antibacterial modified component is the same as that in Example 1.

[0047] Example 3

[0048] Preparation of paper coating

[0049] Step 1: 40g of acrylic acid, 25g of isooctyl acrylate, 20g of glycidyl methacrylate, 15g of hydroxyethyl methacrylate, 8g of antibacterial modified component and 60g of deionized water are added to a reactor, ultrasonically dispersed at an ultrasonic frequency of 90kHz to form a uniform liquid material, filled with argon for protection, 5g of azobisisobutyronitrile is added to the liquid material, and after the addition, heating is turned on, the temperature is controlled to 80°C, and the mixture is kept warm and stirred for 3h to obtain an acrylic polymer emulsion;

[0050] Step 2: Add 12g talcum powder, 2g propylene glycol, 3g polyethyl acrylate and 3g dimethyl silicone oil to the acrylic polymer emulsion, stir and mix at a rate of 600r / min for 50min, let stand to defoam, and discharge to obtain a paper coating liquid; 185

[0051] Step 3: Evenly apply the paper coating liquid on the surface of the base paper and cure it at room temperature for 4 hours to obtain the paper coating.

[0052] The preparation method of the antibacterial modified component is the same as that in Example 1.

[0053] Comparative Example 1

[0054] Preparation of paper coating

[0055] Step 1: 35 g of acrylic acid, 20 g of isooctyl acrylate, 15 g of glycidyl methacrylate, 10 g of hydroxyethyl methacrylate, 7 g of zinc oxide and 50 g of deionized water are added to a reaction kettle, and ultrasonically dispersed at an ultrasonic frequency of 80 kHz to form a uniform liquid material, and argon gas is filled for protection. 4 g of azobisisobutyronitrile is added to the liquid material. After the addition is completed, heating is turned on, the temperature is controlled to 70°C, and the mixture is stirred for 2 hours to obtain an acrylic polymer emulsion;

[0056] Step 2: Add 10g of talc, 1.5g of propylene glycol, 2g of polyethyl acrylate and 2.5g of dimethyl silicone oil to the acrylic polymer emulsion, stir and mix at a speed of 500r / min for 40min, let it stand for defoaming, and discharge the material to obtain a paper coating liquid;

[0057] Step 3: Evenly apply the paper coating liquid on the surface of the base paper and cure it at room temperature for 3 hours to obtain the paper coating.

[0058] Comparative Example 2

[0059] Preparation of paper coating

[0060] Step 1: 35g of acrylic acid, 20g of isooctyl acrylate, 15g of glycidyl methacrylate, 10g of hydroxyethyl methacrylate, 7g of polymerizable intermediate and 50g of deionized water are added to a reactor, ultrasonically dispersed at an ultrasonic frequency of 80kHz until a uniform liquid is formed, and argon gas is filled for protection. 4g of azobisisobutyronitrile is added to the liquid. After the addition is completed, heating is turned on, the temperature is controlled to 70°C, and the mixture is stirred for 2h to obtain an acrylic polymer emulsion;

[0061] Step 2: Add 10g of talc, 1.5g of propylene glycol, 2g of polyethyl acrylate and 2.5g of dimethyl silicone oil to the acrylic polymer emulsion, stir and mix at a speed of 500r / min for 40min, let it stand for defoaming, and discharge the material to obtain a paper coating liquid;

[0062] Step 3: Evenly apply the paper coating liquid on the surface of the base paper and cure it at room temperature for 3 hours to obtain the paper coating.

[0063] The preparation method of the polymerizable intermediate is the same as that in Example 1.

[0064] Comparative Example 3

[0065] Preparation of paper coating

[0066] Step 1: 35 g of acrylic acid, 20 g of isooctyl acrylate, 15 g of glycidyl methacrylate, 10 g of hydroxyethyl methacrylate and 50 g of deionized water are added to a reaction kettle, and ultrasonically dispersed at an ultrasonic frequency of 80 kHz to form a uniform liquid material, and argon gas is filled for protection. 4 g of azobisisobutyronitrile is added to the liquid material. After the addition is completed, heating is turned on, the temperature is controlled to 70°C, and the mixture is kept warm and stirred for 2 hours to obtain an acrylic polymer emulsion;

[0067] Step 2: Add 10g of talc, 1.5g of propylene glycol, 2g of polyethyl acrylate and 2.5g of dimethyl silicone oil to the acrylic polymer emulsion, stir and mix at a speed of 500r / min for 40min, let it stand for defoaming, and discharge the material to obtain a paper coating liquid;

[0068] Step 3: Evenly apply the paper coating liquid on the surface of the base paper and cure it at room temperature for 3 hours to obtain the paper coating.

[0069] Performance Testing

[0070] The paper coatings prepared in Examples 1 to 3 of the present invention and Comparative Examples 1 to 3 were tested for antibacterial properties and antibacterial durability according to GB / T 21866-2008 "Determination of antibacterial properties and antibacterial effects of antibacterial coatings (paint films)", and Staphylococcus aureus was selected as the test strain. The specific test results are shown in Table 1:

[0071] Table 1 - Performance Test

[0072]

[0073] From the test results in Table 1, it can be seen that the paper coatings prepared in Examples 1 to 3 have excellent antibacterial properties and show good antibacterial persistence; in the paper coating prepared in Comparative Example 1, unmodified zinc oxide is used to replace the antibacterial modified component. Compared with the examples, the antibacterial performance of the paper coating is average. It is speculated that this may be because the added zinc oxide cannot be evenly dispersed in the matrix, resulting in a decrease in the antibacterial performance of the paper coating and poor antibacterial persistence; in the paper coating prepared in Comparative Example 2, a polymeric intermediate is used to replace the antibacterial modified component. Compared with the examples, after irradiation with ultraviolet light for 2 hours, the antibacterial performance of the paper coating is average. It is speculated that this may be because it cannot synergize with zinc oxide to produce an organic-inorganic multiple synergistic antibacterial effect, resulting in a decrease in the antibacterial performance of the paper coating, and it cannot be cross-linked with the matrix, so it also performs poorly in antibacterial persistence; in the paper coating prepared in Comparative Example 3, no antibacterial modified component is added, so the antibacterial performance and antibacterial durability of the paper coating are the worst.

[0074] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. An antibacterial repulpable functional paper coating, characterized in that: The paper coating is formed by coating a paper coating liquid on the surface of base paper; the paper coating liquid comprises the following raw materials in parts by weight: 30 to 40 parts of acrylic acid, 15 to 25 parts of isooctyl acrylate, 10 to 20 parts of glycidyl methacrylate, 5 to 15 parts of hydroxyethyl methacrylate, 5 to 8 parts of antibacterial modified components, 40 to 60 parts of deionized water, 3 to 5 parts of azobisisobutyronitrile, 8 to 12 parts of filler, 1 to 2 parts of film-forming aid, 1 to 3 parts of leveling agent, and 2 to 3 parts of defoaming agent.

2. The antibacterial repulpable functional paper coating according to claim 1, characterized in that: The preparation method of the antibacterial modified component comprises the following steps: S1: 1,3-diaminoguanidine hydrochloride and dimethyl sulfoxide are mixed, poured into a reaction kettle, and stirred until a uniform solution is formed. Then, 4-hydroxyisophthalaldehyde is added under continuous nitrogen conditions. After the addition is completed, the temperature is raised to 50-55° C., stirred at this temperature for 4-9 hours, and the solvent is removed by rotary evaporation to obtain a polymer intermediate; S2: Under nitrogen protection, zinc oxide and N-methylpyrrolidone are mixed, and after ultrasonic treatment, a dispersion is formed, 2-chloroacrylic acid and catalyst A are added to the dispersion, and the system temperature is raised to 90-110° C. under stirring conditions, and after heat preservation for 5-7 hours, the solid material is separated, and the modified zinc oxide is obtained after washing and drying. S3: Ultrasonic dispersion of modified zinc oxide in N,N-dimethylformamide to form a uniform dispersion, nitrogen is introduced for deoxygenation, polymer intermediate and sodium carbonate solution are added to the dispersion, heating is started, and after the system temperature reaches 70-80°C, constant temperature stirring is performed for 8-12 hours, and then filtration is performed to collect the product, and the product is washed and dried to obtain an antibacterial modified component.

3. The antibacterial repulpable functional paper coating according to claim 2, characterized in that: In step S2, the average particle size of the zinc oxide is 5 μm.

4. The antibacterial repulpable functional paper coating according to claim 2, characterized in that: In step S2, the catalyst A is any one of tetrabutyl titanate, tetraethyl titanate or tetraisopropyl titanate.

5. The antibacterial repulpable functional paper coating according to claim 2, characterized in that: In step S2, the mass ratio of zinc oxide to 2-chloroacrylic acid is 1:0.1-0.

3.

6. The antibacterial repulpable functional paper coating according to claim 2, characterized in that: In step S3, the mass fraction of the sodium carbonate solution is 5% to 40%.

7. A method for preparing the antibacterial repulpable functional paper coating according to claim 1, characterized in that: The following steps are involved: Step 1: Add acrylic acid, isooctyl acrylate, glycidyl methacrylate, hydroxyethyl methacrylate, antibacterial modified components and deionized water into a reaction kettle, ultrasonically disperse until a uniform liquid is formed, fill with inert gas protection, add azobisisobutyronitrile to the liquid, turn on heating after the addition, control the temperature to 60-80°C, keep warm and stir for 1-3h to obtain an acrylic polymer emulsion; Step 2: Add filler, film-forming aid, leveling agent and defoamer to the acrylic polymer emulsion, stir and mix at a rate of 400-600 r / min for 30-50 min, let stand to defoam, and discharge the material to obtain a paper coating liquid; Step 3: Evenly apply the paper coating liquid on the surface of the base paper and cure it at room temperature for 2 to 4 hours to obtain the paper coating.

8. The method for preparing an antibacterial repulpable functional paper coating according to claim 7, characterized in that: In step 1, during the ultrasonic dispersion, the ultrasonic frequency is 70 to 90 kHz.

9. The method for preparing an antibacterial repulpable functional paper coating according to claim 7, characterized in that: In step 1, the inert gas is any one of argon, neon or helium.

10. The method for preparing an antibacterial repulpable functional paper coating according to claim 7, characterized in that: In step 2, the filler is any one of talc, calcium carbonate or titanium dioxide; the film-forming aid is any one of propylene glycol, propylene glycol methyl ether or dipropylene glycol methyl ether; the leveling agent is any one of polybutyl acrylate or polyethyl acrylate; the defoaming agent is any one of dimethyl silicone oil or fatty alcohol polyoxyethylene ether.

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