Antibacterial and antifouling additive, preparation method thereof, coating composition and plastic packaging product

Abstract

The present invention relates to the technical field of functional additives, and specifically to an antibacterial and antifouling additive, a preparation method thereof, a coating composition, and a plastic packaging product. The preparation method of the antibacterial and antifouling additive comprises the following steps: (1) surface-treating anion powder with a coupling agent containing an end amino group to obtain amino-coupled anion powder; (2) subjecting the amino-coupled anion powder to a dehydration condensation reaction with a carboxyl-containing RAFT agent in the presence of an acylation catalyst and a carboxyl activator to obtain an intermediate; and (3) subjecting the intermediate to a photopolymerization reaction with a monomer containing a quaternary ammonium group and a thioacrylate compound under the action of a photocatalyst under illumination to obtain the antibacterial and antifouling additive. The coating composition comprises the antibacterial and antifouling additive obtained by the preparation method, an adhesive, and a solvent, and may further comprise other additives. Spraying the antibacterial and antifouling additive on the surface of a polyolefin packaging product can impart good antibacterial and antifouling properties to the product.

Description

Technical Field

[0001] The present invention relates to the technical field of functional additives, and in particular to an antibacterial and antifouling additive and a preparation method thereof, a coating composition and a plastic packaging product. Background Art

[0002] Antimicrobials, a new class of plastic additives, have garnered significant attention, particularly as environmentally friendly antimicrobials have gradually replaced traditional antimicrobials. Antimicrobials are commonly used in daily necessities, toys, and other fields, where general-purpose plastics and engineering plastics are often used, and inorganic and / or organic antimicrobials are often employed.

[0003] Antimicrobial agents, even when added to plastics in very small quantities, can maintain their conventional properties and processing characteristics while maintaining their antibacterial efficacy, playing a crucial role in the development of plastic products. Antimicrobial products achieve their antibacterial properties by incorporating functional additives such as antimicrobials into the product. These agents kill or inhibit the growth of surface bacteria through surface contact, thereby maintaining the long-term hygienic properties of the product.

[0004] Currently, common antimicrobial agents can be divided into three categories: organic, inorganic, and natural, and are used in different fields. Among these three categories, organic antimicrobials have poor heat resistance and are easily decomposed. Natural antimicrobials also have poor heat resistance, are difficult to process, and require limited research time. Inorganic antimicrobials have good heat resistance, a broad antimicrobial spectrum, and a long effective period, making them the most widely used. However, in the plastics field, due to the interfacial effect between inorganic materials and polymers, even when using coupling agents, inorganic antimicrobials will still migrate to the surface of the polymer material, thereby losing their antimicrobial properties.

[0005] Common plastics such as polyolefins offer advantages such as good chemical stability, corrosion resistance, non-toxicity, and low cost. However, polyolefin products are prone to bacterial growth during use. Antimicrobial packaging products are often required in the plastic packaging industry. However, these products only have a limited antimicrobial function and have other drawbacks, such as difficulty cleaning surfaces contaminated with oil and other substances. Therefore, this patent develops an antimicrobial and antifouling additive and applies it to the surface of polyolefin packaging products to form an antimicrobial and antifouling coating, achieving an antimicrobial and antifouling effect on the packaging products. Summary of the Invention

[0006] In order to solve the above technical problems, an antibacterial and antifouling agent and its preparation method, a coating composition and a plastic packaging product are provided. The present invention has developed an antibacterial and antifouling agent, which can achieve antibacterial and antifouling effects when applied to packaging products.

[0007] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] The preparation method of the antibacterial and antifouling agent comprises the following steps:

[0009] (1) surface treating the negative ion powder with a coupling agent containing a terminal amino group to obtain an amino-coupled negative ion powder;

[0010] (2) Under the conditions of an acylation catalyst and a carboxyl activator, the amino coupling anion powder and a carboxyl-containing RAFT reagent are subjected to a dehydration condensation reaction to obtain an intermediate;

[0011] (3) The intermediate is subjected to photopolymerization reaction with a monomer containing a quaternary ammonium group and a thioacrylate compound under the action of a photocatalyst and irradiated with light to obtain an antibacterial and antifouling agent.

[0012] Furthermore, the coupling agent containing terminal amino groups is selected from one of KH540 (γ-aminopropyltrimethoxysilane), KH550 (γ-aminopropyltriethoxysilane), KH792 (N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane), and KH602 (N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane); the negative ion powder includes at least one of tourmaline, medical stone, opal, and wizard stone;

[0013] The acylation catalyst is 4-dimethylaminopyridine (DMAP); the carboxyl activator is 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC); the carboxyl-containing RAFT agent is trithiocarbonate (2-methyl-2-[(dodecylthiocarbonyl)thio]propionic acid);

[0014] The monomer containing a quaternary ammonium group is any one of (2-methacryloyloxy)ethyltrimethylammonium chloride, methacryloylpropyltrimethylammonium chloride, diallyldimethylammonium chloride, and (3-methacryloyloxy)-propyltrimethylammonium chloride; the thioacrylate compound is at least one of 2-(methylthio)ethyl acrylate, 2-(phenylthio)ethyl acrylate, 2-(methylthio)ethyl methacrylate, 2-acrylate-2-(phenylthio)-1-[(phenylthio)methyl]ethyl ester, 2-(ethylthio)ethyl acrylate, and 2-naphthylthioethyl acrylate; and the photocatalyst is zinc tetraphenylporphyrin (ZnTPP).

[0015] Furthermore, the surface treatment is to hydrolyze the coupling agent containing terminal amino groups at pH=8-10, then add the negative ion powder, react at 40-75°C for 2-4h under stirring, wash and dry to obtain amino-coupled negative ion powder.

[0016] Furthermore, the dehydration condensation reaction uses DMF as a solvent, reacts at room temperature for 48 hours, and then the product is washed and dried to obtain an intermediate.

[0017] Furthermore, the photopolymerization reaction uses DMSO as a solvent and is irradiated with light at a wavelength of 495-575 nm for 10-15 hours.

[0018] Furthermore, the mass ratio of the negative ion powder to the coupling agent containing a terminal amino group is 1:0.1-0.15; the mass ratio of the amino coupling negative ion powder, the carboxyl-containing RAFT agent, the carboxyl activator, and the acylation catalyst is (6-7):(4-5):0.5:0.3; the mass ratio of the intermediate, the monomer containing a quaternary ammonium group, the thioacrylate compound, and the photocatalyst is (1-1.2):(0.5-0.8):(0.4-0.6):0.01.

[0019] The reaction process for forming the antibacterial and antifouling additive is as follows, wherein the coupling agent containing an amino group is exemplified by KH540, the monomer containing a quaternary ammonium group is exemplified by (2-methacryloyloxy)ethyltrimethylammonium chloride, and the thioacrylate compound is exemplified by 2-(methylthio)ethyl acrylate:

[0020]

[0021] The second aspect of the present invention provides an antibacterial and antifouling agent obtained by the above preparation method.

[0022] The third aspect of the present invention provides a coating composition comprising the following materials in parts by weight: 20-25 parts of the antibacterial and antifouling agent obtained by the above preparation method, 10-15 parts of an adhesive, and 5-8 parts of a solvent.

[0023] Furthermore, the antibacterial and antifouling coating composition further comprises the following materials in parts by weight: 1-8 parts of an antibacterial adjuvant, 1-5 parts of a colorant, 1-4 parts of a filler, and 1-2 parts of an anti-settling agent.

[0024] Furthermore, the adhesive is one of epoxy resin and polyurethane adhesive; the antibacterial adjuvant includes at least one of silver nanoparticles, alkyl betaine, alkylamide betaine, hydroxysulfonpropyl betaine, and porous material ZIF-8.

[0025] A fourth aspect of the present invention provides a plastic packaging product, wherein the antibacterial and antifouling agent obtained by the above preparation method is directly used as a processing aid and melt-blended with a polyolefin material, extruded and granulated, and then molded to obtain an antibacterial and antifouling plastic packaging product;

[0026] Alternatively, the coating composition is directly sprayed on the surface of the polyolefin plastic packaging product.

[0027] Beneficial technical effects:

[0028] The negative ion powder is surface-modified by grafting a silane coupling agent containing an amino group, thereby imparting a certain degree of hydrophobicity to its surface. The hydrophobicity exhibits a certain degree of antifouling function. The negative ion powder with the grafted silane coupling agent is then bonded to the amide group with a long-chain antibacterial group containing a quaternary ammonium salt, a sulfur-containing acrylate containing a terminal methyl group, and a long-chain thiocarbonate using the photoinduced electron transfer-reversible addition fragmentation chain transfer radical polymerization (PET-RAFT) method. Due to the large molecular weight main chain in the molecular structure, the powder has good adhesion to polyolefins, improves its stability in polymer materials, achieves a long-lasting antibacterial effect, and improves its heat resistance. The terminal groups of the molecular structure have long aliphatic chains, multiple terminal methyl groups, and thio groups, which impart good and strong hydrophobicity. Since the negative ion powder itself has certain antibacterial properties, after the antibacterial groups and strong hydrophobic groups are grafted onto its surface, the powder can be used as an additive to prepare a coating composition, thereby imparting good antibacterial and strong hydrophobic antifouling properties to polyolefin packaging products. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, rather than all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] Unless otherwise specifically stated, the numerical value set forth in these embodiments does not limit the scope of the present invention. Technology and methods known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology and methods should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments can have different values.

[0031] In the following examples, experimental methods without specific conditions are generally measured according to national standards. If there are no corresponding national standards, they are measured according to the general international standards or the standards proposed by relevant companies. Unless otherwise stated, all parts are by weight and all percentages are by weight.

[0032] Example 1

[0033] 1. A method for preparing an antibacterial and antifouling agent, comprising the following steps:

[0034] (1) KH540 was added to water and stirred, and the pH was adjusted to 8 for hydrolysis. Then, an ethanol dispersion containing tourmaline powder was added, and the mixture was heated to 40° C. under stirring and reacted for 4 hours. The mixture was then filtered, washed with ethanol and water several times until neutral, and dried. Amino-coupled tourmaline powder was obtained through the above surface treatment.

[0035] The mass ratio of tourmaline powder to KH540 is 1:0.1; the tourmaline powder used is white powder with a particle size of less than 800 mesh;

[0036] (2) Amino-coupling tourmaline powder, 2-methyl-2-[(dodecylthiothiocarbonyl)thio]propionic acid, EDC carboxyl activator, and DMAP acylation catalyst were added to DMF in a mass ratio of 6:4:0.5:0.3, with the amount of DMF accounting for 2.6 times the mass of the total materials. After stirring at room temperature for 48 hours, the product was washed with DMF and methanol in turn, and dried to obtain an intermediate;

[0037] (3) The intermediate, (2-methacryloyloxy)ethyltrimethylammonium chloride, 2-(methylthio)ethyl acrylate, and photocatalyst ZnTPP were added to DMSO in a mass ratio of 1:0.5:0.4:0.01, and the amount of DMSO accounted for 1.8 times the mass of the total materials. Under stirring, a green LED lamp (λ = 495-575nm) was used to carry out photopolymerization reaction for 10 hours to obtain an antibacterial and antifouling agent.

[0038] 2. A coating composition comprising the following materials in parts by weight: 20 parts of the antibacterial and antifouling agent obtained by the above preparation method, 15 parts of an epoxy resin adhesive, and 10 parts of a benzene solvent, which are fully stirred to obtain a coating composition.

[0039] 3. Plastic packaging products: The surface of a polypropylene packaging barrel is pretreated by corona treatment, and then the coating composition is evenly sprayed on the surface of the polypropylene packaging barrel. After drying in a drying oven at 60-80°C, a plastic packaging product with an antibacterial and antifouling coating is obtained.

[0040] Example 2

[0041] 1. A method for preparing an antibacterial and antifouling agent, comprising the following steps:

[0042] (1) KH550 was added to water and stirred, and the pH was adjusted to 9 for hydrolysis. Then, an ethanol dispersion containing medical stone powder was added, and the mixture was heated to 55° C. and reacted for 3 h under stirring. The mixture was filtered, washed with ethanol and water several times until neutral, and then dried. Amino-coupled medical stone powder was obtained through the above surface treatment.

[0043] The mass ratio of medical stone powder to KH550 is 1:0.15; the particle size of the medical stone powder used is less than 800 mesh;

[0044] (2) amino coupling medical stone powder, 2-methyl-2-[(dodecylthiothiocarbonyl)thio]propionic acid, EDC carboxyl activator, and DMAP acylation catalyst were added to DMF in a mass ratio of 7:5:0.5:0.3, with the amount of DMF accounting for 3 times the mass of the total materials. After stirring at room temperature for 48 hours, the product was washed with DMF and methanol in turn, and dried to obtain an intermediate;

[0045] (3) The intermediate, methacryloylpropyltrimethylammonium chloride, 2-(phenylthio)ethyl acrylate, and photocatalyst ZnTPP were added to DMSO in a mass ratio of 1.1:0.7:0.6:0.01, and the amount of DMSO accounted for 1.8 times the mass of the total materials. Under stirring, a green LED lamp (λ = 495-575nm) was used to carry out photopolymerization reaction for 13 hours to obtain an antibacterial and antifouling agent.

[0046] 2. A coating composition comprising the following materials in parts by weight: 23 parts of the antibacterial and antifouling agent obtained by the above preparation method, 10 parts of an epoxy resin adhesive, and 18 parts of a benzene solvent, which are fully stirred to obtain a coating composition.

[0047] 3. Plastic packaging products: The surface of a polypropylene packaging barrel is pretreated by corona treatment, and then the coating composition is evenly sprayed on the surface of the polypropylene packaging barrel. After drying in a drying oven at 60-80°C, a plastic packaging product with an antibacterial and antifouling coating is obtained.

[0048] Example 3

[0049] 1. A method for preparing an antibacterial and antifouling agent, comprising the following steps:

[0050] (1) KH792 was added to water and stirred, and the pH was adjusted to 10 for hydrolysis. Then, an ethanol dispersion containing tourmaline powder was added, and the mixture was heated to 75° C. under stirring for 2 h. After that, the mixture was filtered, washed with ethanol and water several times until neutral, and then dried. Amino-coupled tourmaline powder was obtained through the above surface treatment.

[0051] The mass ratio of tourmaline powder to KH792 is 1:0.15; the tourmaline powder used is white powder with a particle size of less than 800 mesh;

[0052] (2) adding amino-coupled tourmaline powder, 2-methyl-2-[(dodecylthiothiocarbonyl)thio]propionic acid, EDC carboxyl activator, and DMAP acylation catalyst to DMF in a mass ratio of 7:5:0.5:0.3, with the amount of DMF accounting for 3.7 times the mass of the total materials, stirring at room temperature for dehydration condensation reaction for 48 hours, and then washing the product with DMF and methanol in sequence, and drying to obtain an intermediate;

[0053] (3) The intermediate, dimethyldiallylammonium chloride, 2-(methylthio)ethyl methacrylate, and photocatalyst ZnTPP were added to DMSO in a mass ratio of 1.2:0.8:0.5:0.01, and the amount of DMSO accounted for 2.6 times the mass of the total materials. Under stirring, a green LED lamp (λ = 495-575nm) was used to carry out photopolymerization reaction for 15 hours to obtain an antibacterial and antifouling agent.

[0054] 2. A coating composition comprising the following materials in parts by weight: 25 parts of the antibacterial and antifouling agent obtained by the above preparation method, 10 parts of a polyurethane resin adhesive, and 20 parts of a benzene solvent, which are fully stirred to obtain a coating composition.

[0055] 3. Plastic packaging products: The surface of a polypropylene packaging barrel is pretreated by corona treatment, and then the coating composition is evenly sprayed on the surface of the polypropylene packaging barrel. After drying in a drying oven at 60-80°C, a plastic packaging product with an antibacterial and antifouling coating is obtained.

[0056] Example 4

[0057] 1. A method for preparing an antibacterial and antifouling agent, comprising the following steps:

[0058] (1) KH602 was added to water and stirred, and the pH was adjusted to 10 for hydrolysis. Then, an ethanol dispersion containing medical stone powder was added, and the mixture was heated to 40°C for reaction for 4 hours under stirring. The mixture was then filtered, washed with ethanol and water several times until neutral, and then dried. The amino-coupled medical stone powder was obtained through the above surface treatment.

[0059] The mass ratio of medical stone powder to KH602 is 1:0.1; the particle size of the medical stone powder used is less than 800 mesh;

[0060] (2) amino coupling medical stone powder, 2-methyl-2-[(dodecylthiothiocarbonyl)thio]propionic acid, EDC carboxyl activator, and DMAP acylation catalyst were added to DMF in a mass ratio of 6:4:0.5:0.3, with the amount of DMF accounting for 4.4 times the mass of the total materials. After stirring at room temperature for 48 hours, the dehydration condensation reaction was carried out, and the product was washed with DMF and methanol in turn, and dried to obtain an intermediate;

[0061] (3) The intermediate, (3-methacryloyloxy)-propyltrimethylammonium chloride, 2-naphthylthioethyl acrylate, and photocatalyst ZnTPP were added to DMSO in a mass ratio of 1.2:0.8:0.5:0.01, and the amount of DMSO accounted for 1.8 times the mass of the total materials. Under stirring, a green LED lamp (λ = 495-575nm) was used to carry out photopolymerization reaction for 12 hours to obtain an antibacterial and antifouling agent.

[0062] 2. A coating composition comprising the following materials in parts by weight: 20 parts of the antibacterial and antifouling agent obtained by the above preparation method, 13 parts of an epoxy resin adhesive, and 15 parts of a benzene solvent, which are fully stirred to obtain a coating composition.

[0063] 3. Plastic packaging products: The surface of a polypropylene packaging barrel is pretreated by corona treatment, and then the coating composition is evenly sprayed on the surface of the polypropylene packaging barrel. After drying in a drying oven at 60-80°C, a plastic packaging product with an antibacterial and antifouling coating is obtained.

[0064] Example 5

[0065] 1. A method for preparing an antibacterial and antifouling agent, comprising the following steps:

[0066] (1) KH550 was added to water and stirred, and the pH was adjusted to 9 for hydrolysis. Then, an ethanol dispersion containing negative ion powder (tourmaline powder and medical stone powder in equal mass ratio) was added, and the mixture was heated to 55°C under stirring for 4 hours. The mixture was then filtered, washed with ethanol and water several times until neutral, and dried. The amino-coupled negative ion powder was obtained through the above surface treatment.

[0067] The mass ratio of negative ion powder to KH550 is 1:0.15; the particle size of the negative ion powder used is less than 800 mesh;

[0068] (2) adding amino coupling anion powder, 2-methyl-2-[(dodecylthiothiocarbonyl)thio]propionic acid, EDC carboxyl activator, and DMAP acylation catalyst to DMF in a mass ratio of 6:4:0.5:0.3, with the amount of DMF accounting for 3.2 times the mass of the total materials, stirring at room temperature for dehydration condensation reaction for 48 hours, and then washing the product with DMF and methanol in sequence, and drying to obtain an intermediate;

[0069] (3) The intermediate, (2-methacryloyloxy)ethyltrimethylammonium chloride, 2-acrylic acid-2-(phenylthio)-1-[(phenylthio)methyl]ethyl ester, and photocatalyst ZnTPP were added to DMSO in a mass ratio of 1.1:0.7:0.6:0.01, and the amount of DMSO accounted for 1.4 times the mass of the total materials. Under stirring, a green LED lamp (λ=495-575nm) was used to carry out photopolymerization reaction for 15 hours to obtain an antibacterial and antifouling agent.

[0070] 2. A coating composition comprising the following materials in parts by weight: 25 parts of an antibacterial and antifouling agent obtained by the above-mentioned preparation method, 15 parts of an epoxy resin adhesive, 5 parts of a porous material ZIF-8 antibacterial adjuvant, 5 parts of a coloring pigment, 3 parts of a filler (a mixture of talc, silica powder, and mica in equal mass ratios), 2 parts of an anti-settling agent polyethylene wax, and 18 parts of a toluene solvent. The mixture is thoroughly stirred to obtain a coating composition.

[0071] 3. Plastic packaging products: The surface of a polypropylene packaging barrel is pretreated by corona treatment, and then the coating composition is evenly sprayed on the surface of the polypropylene packaging barrel. After drying in a drying oven at 60-80°C, a plastic packaging product with an antibacterial and antifouling coating is obtained.

[0072] Example 6

[0073] 1. A method for preparing an antibacterial and antifouling agent, comprising the following steps:

[0074] (1) KH540 was added to water and stirred, and the pH was adjusted to 9 for hydrolysis. Then, an ethanol dispersion containing tourmaline powder was added, and the mixture was heated to 40° C. under stirring for 4 hours. After that, the mixture was filtered, washed with ethanol and water several times until neutral, and then dried. Amino-coupled tourmaline powder was obtained through the above surface treatment.

[0075] The mass ratio of tourmaline powder to KH540 is 1:0.1; the tourmaline powder used is white powder with a particle size of less than 800 mesh;

[0076] (2) Amino-coupling tourmaline powder, 2-methyl-2-[(dodecylthiothiocarbonyl)thio]propionic acid, EDC carboxyl activator, and DMAP acylation catalyst were added to DMF in a mass ratio of 6:4:0.5:0.3, with the amount of DMF accounting for 2.6 times the mass of the total materials. After stirring at room temperature for 48 hours, the product was washed with DMF and methanol in turn, and dried to obtain an intermediate;

[0077] (3) The intermediate, (2-methacryloyloxy)ethyltrimethylammonium chloride, 2-(methylthio)ethyl acrylate and 2-(phenylthio)ethyl acrylate, and photocatalyst ZnTPP are added to DMSO in a mass ratio of 1:0.5:0.4:0.01, and the amount of DMSO accounts for 1.7 times the mass of the total materials. Under stirring, a green LED lamp (λ = 495-575nm) is used to carry out photopolymerization reaction for 10 hours to obtain an antibacterial and antifouling agent.

[0078] 2. A coating composition comprising the following materials in parts by weight: 20 parts of an antibacterial and antifouling agent obtained by the above-mentioned preparation method, 15 parts of an epoxy resin adhesive, 5 parts of a silver nanoparticle antibacterial additive, 1 part of dodecyl dimethyl betaine, 3 parts of a coloring pigment, 2 parts of a filler (a mixture of talc, silica powder, and mica in equal mass ratios), 1 part of an anti-settling agent, polyethylene wax, and 10 parts of a toluene solvent. The mixture is thoroughly stirred to obtain a coating composition.

[0079] 3. Plastic packaging products: The surface of a polypropylene packaging barrel is pretreated by corona treatment, and then the coating composition is evenly sprayed on the surface of the polypropylene packaging barrel. After drying in a drying oven at 60-80°C, a plastic packaging product with an antibacterial and antifouling coating is obtained.

[0080] Example 7

[0081] 20 parts by weight of the antibacterial and antifouling agent prepared in Example 6 and 80 parts of polyolefin (PP) were added to an injection molding machine for melt blending, and then injection molded into an antibacterial and antifouling plastic packaging product. The melting and injection molding temperatures did not exceed 180°C.

[0082] Example 8

[0083] 25 parts by weight of the antibacterial and antifouling agent prepared in Example 6 and 75 parts of polyolefin (PP) were added to an injection molding machine for melt blending, and then injection molded into an antibacterial and antifouling plastic packaging product. The melting and injection molding temperatures did not exceed 180°C.

[0084] Example 9

[0085] 28 parts by weight of the antibacterial and antifouling agent prepared in Example 6 and 72 parts of polyolefin (PP) were added to an injection molding machine for melt blending, and then injection molded into an antibacterial and antifouling plastic packaging product. The melting and injection molding temperatures did not exceed 180°C.

[0086] Comparative Example 1

[0087] The coating composition comprises the following materials in parts by weight: 15 parts of epoxy resin adhesive, 5 parts of coloring pigment, 4 parts of filler, 1 part of anti-settling agent, and 10 parts of toluene solvent.

[0088] Plastic packaging products are sprayed with the coating composition of this comparative example.

[0089] Comparative Example 2

[0090] The coating composition comprises the following materials in parts by weight: 15 parts of epoxy resin adhesive, 8 parts of dodecyl dimethyl betaine, 5 parts of coloring pigment, 4 parts of filler, 1 part of anti-settling agent, and 10 parts of toluene solvent.

[0091] Plastic packaging products are sprayed with the coating composition of this comparative example.

[0092] Comparative Example 3

[0093] 100 parts by weight of polyolefin (PP) were added into an injection molding machine for melt blending, and then injection-molded into a mold to obtain a plastic packaging product.

[0094] The antibacterial and antifouling coatings produced on the surfaces of packaging barrels according to the above examples and comparative examples were tested for friction resistance, hydrophobicity, and antibacterial properties (Table 1). The antibacterial and antifouling plastic packaging products were tested for mechanical properties, heat resistance, hydrophobicity, and antibacterial properties (Table 2). Antibacterial properties were determined using the GB / T4789.2-2003 standard for antimicrobial flora testing; rub fastness was tested using a 100-grid test; and hydrophobicity was measured using a contact angle test.

[0095] Table 1 Examples and Comparative Examples Data

[0096]

[0097] Table 2 Examples and Comparative Examples Data

[0098]

[0099] As can be seen from Tables 1 and 2, the antifouling and antibacterial negative ion powder prepared in the present invention has excellent hydrophobic antifouling and antibacterial effects, with strong hydrophobicity even achieving super-hydrophobic, self-cleaning coating properties (a contact angle greater than 150° is considered a super-hydrophobic, self-cleaning surface). Compared to melt blending, the coating composition obtained by mixing the antifouling and antibacterial negative ion powder prepared in the present invention with other additives has better surface stain resistance and antibacterial properties.

[0100] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing an antibacterial and antifouling agent, characterized in that: The steps include: (1) surface treating the negative ion powder with a coupling agent containing a terminal amino group to obtain an amino-coupled negative ion powder; the surface treatment comprises first hydrolyzing the coupling agent containing a terminal amino group at pH = 8-10, then adding the negative ion powder, reacting at 40-75° C. for 2-4 hours under stirring, washing, and drying to obtain the amino-coupled negative ion powder; (2) Under the conditions of an acylation catalyst and a carboxyl activator, the amino coupling anion powder is subjected to a dehydration condensation reaction with a carboxyl-containing RAFT reagent to obtain an intermediate; the dehydration condensation reaction uses DMF as a solvent, reacts at room temperature for 48 hours, and then washes and dries the product to obtain the intermediate; (3) subjecting the intermediate to a monomer containing a quaternary ammonium group and a thioacrylate compound under the action of a photocatalyst and irradiating with light to perform a photopolymerization reaction to obtain an antibacterial and antifouling agent; the photopolymerization reaction is performed using DMSO as a solvent and irradiating with light at a wavelength of 495-575 nm for 10-15 hours; The coupling agent containing terminal amino groups is selected from one of KH540, KH550, KH792, and KH602; The negative ion powder includes at least one of tourmaline powder, medical stone powder, opal powder, and Qicai stone powder; The carboxyl activator is 1-ethyl-(3-dimethylaminopropyl)carbodiimide; The carboxyl-containing RAFT agent is a trithiocarbonate; The monomer containing a quaternary ammonium group is any one of (2-methacryloyloxy)ethyltrimethylammonium chloride, methacryloylpropyltrimethylammonium chloride, diallyldimethylammonium chloride, and (3-methacryloyloxy)-propyltrimethylammonium chloride; The thioacrylate compound is at least one of 2-(methylthio)ethyl acrylate, 2-(phenylthio)ethyl acrylate, 2-(methylthio)ethyl methacrylate, 2-(phenylthio)-1-[(phenylthio)methyl]ethyl 2-acrylate, 2-(ethylthio)ethyl acrylate, and 2-naphthylthioethyl acrylate; The mass ratio of the negative ion powder to the coupling agent containing the terminal amino group is 1:0.1-0.15; The mass ratio of the amino coupling anion powder, the carboxyl-containing RAFT agent, the carboxyl activator, and the acylation catalyst is (0.6-0.7):(0.4-0.5):0.05:0.03; The mass ratio of the intermediate, the monomer containing a quaternary ammonium group, the thioacrylate compound, and the photocatalyst is (1-1.2):(0.5-0.8):(0.4-0.6):0.

01.

2. The method for preparing the antibacterial and antifouling agent according to claim 1, wherein: The acylation catalyst is 4-dimethylaminopyridine; and the photocatalyst is tetraphenylporphyrin zinc.

3. The antibacterial and antifouling agent obtained according to the preparation method according to any one of claims 1 to 2.

4. A coating composition, characterized in that The invention comprises the following materials in parts by weight: 20-25 parts of an antibacterial and antifouling agent obtained by the preparation method according to any one of claims 1 to 2, 10-15 parts of an adhesive, and 5-8 parts of a solvent.

5. The coating composition according to claim 4, characterized in that The coating composition further comprises the following materials in parts by weight: 1-8 parts of an antibacterial adjuvant, 1-5 parts of a colorant, 1-4 parts of a filler, and 1-2 parts of an anti-settling agent.

6. The coating composition according to claim 5, characterized in that The adhesive is one of epoxy resin and polyurethane adhesive; the antibacterial adjuvant includes at least one of silver nanoparticles, alkyl betaine, alkyl amide betaine, hydroxysulfonpropyl betaine, and porous material ZIF-8.

7. Plastic packaging product, characterized in that, The antibacterial and antifouling additive obtained by the preparation method according to any one of claims 1 to 2 is directly used as a processing aid and melt-blended with a polyolefin material, extruded and granulated, and then molded to obtain an antibacterial and antifouling plastic packaging product; Alternatively, the coating composition according to any one of claims 4 to 6 is directly sprayed on the surface of the polyolefin plastic packaging product.

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