An environmentally friendly antibacterial coating and its preparation method

Abstract

This invention belongs to the field of coating technology. Specifically, it discloses an environmentally friendly antibacterial coating and its preparation method, comprising the following components by weight: 45-55 parts waterborne epoxy emulsion, 14-18 parts modified shell powder, 6-10 parts film-forming aid, 3-6 parts pigment, 2-4 parts wetting agent, 0.2-0.8 parts leveling agent, 0.2-0.8 parts defoamer, and 15-20 parts water. The film-forming aid includes hydroxyl-containing waterborne acrylic resin and diatomaceous earth, wherein the mass ratio of the waterborne acrylic resin to diatomaceous earth is 1:(0.2-0.5). The coating exhibits excellent antibacterial properties.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to an environmentally friendly antibacterial coating and its preparation method. Background Technology

[0002] As people's living standards improve and their environmental awareness increases, the requirements for coating products are also becoming more stringent. Traditional coating products, during long-term use, are prone to the growth of bacteria, mold, and other microorganisms, posing a potential threat to human health.

[0003] While existing antibacterial coatings possess certain antibacterial properties, they often contain toxic and harmful antibacterial agents, causing adverse effects on human health and the environment. Therefore, developing a coating product that combines excellent antibacterial properties with environmental friendliness is of significant practical importance and has broad application prospects.

[0004] Therefore, this application is submitted. Summary of the Invention

[0005] This invention provides an environmentally friendly antibacterial coating and its preparation method, wherein the coating has excellent antibacterial properties.

[0006] The present invention solves its technical problem by adopting the following technical solution:

[0007] An environmentally friendly antibacterial coating comprises the following components in parts by weight: 45-55 parts waterborne epoxy emulsion, 14-18 parts modified shell powder, 6-10 parts film-forming aid, 3-6 parts pigment, 2-4 parts wetting agent, 0.2-0.8 parts leveling agent, 0.2-0.8 parts defoamer, and 15-20 parts water;

[0008] The film-forming aid includes a hydroxyl-containing aqueous acrylic resin and diatomaceous earth, wherein the mass ratio of the aqueous acrylic resin to diatomaceous earth is 1:(0.2~0.5).

[0009] This invention creatively incorporates modified shell powder into an aqueous epoxy emulsion, significantly enhancing its antibacterial effect. The film-forming aid comprises a hydroxyl-containing aqueous acrylic resin and diatomaceous earth. The hydroxyl-containing aqueous acrylic resin possesses abundant functional groups and high compatibility, improving the compatibility of diatomaceous earth and modified shell powder in the system. Through intermolecular interactions and functional group reactions, it promotes the curing of the coating, fostering the formation of a continuous, uniform, and dense film. Furthermore, due to the charge repulsion between the aqueous acrylic resin and the dimethyl diallyl ammonium chloride groups in the modified shell powder, it promotes the migration of more modified shell powder to the coating surface, resulting in a more uniform dispersion on the coating surface and more effective... Antibacterial properties; the diatomaceous earth described herein has a microporous structure, which can adsorb and fix resin molecules and pigments in the coating, improve the bonding force between the coating and the substrate (the substrate to which the coating is applied), and enable the coating to adhere better to the substrate, promoting the formation of a more stable and smoother coating film. The two work together to effectively promote the formation of a smooth, continuous, uniform, and dense coating film, improve the compatibility of raw materials in the formulation system, and promote more migration of modified shell powder to the surface. Thus, the specific film-forming aid of this invention can improve the antibacterial effect to a certain extent (indirectly). In addition, the film-forming aid of this invention does not use traditional ethers and alcohols, reducing the release of volatile organic compounds and resulting in low VOC emissions.

[0010] As a preferred embodiment of the present invention, it comprises the following components in parts by weight: 50 parts of aqueous epoxy emulsion, 16 parts of modified shell powder, 8 parts of film-forming aid, 4 parts of pigment, 3 parts of wetting agent, 0.5 parts of leveling agent, 0.5 parts of defoamer, and 18 parts of water.

[0011] As a preferred embodiment of the present invention, the solid content of the aqueous epoxy emulsion is 52-53%, and the epoxy equivalent is 950-1050 g / eq.

[0012] In a preferred embodiment of the present invention, the solid content of the hydroxyl-containing waterborne acrylic resin is 37-39%; the viscosity of the hydroxyl-containing waterborne acrylic resin at 25°C is 700-2000 mPa·s; and the hydroxyl content of the hydroxyl-containing waterborne acrylic resin is 4.6-4.8 wt%.

[0013] As a preferred embodiment of the present invention, the method for preparing the modified seashell powder is as follows:

[0014] (1) Crush oyster shells to 50-400 mesh to obtain shell powder, and calcine the shell powder to obtain calcined shell powder;

[0015] (2) Add the calcined shell powder to the nitric acid solution, disperse it evenly, add γ-glycidoxypropyltrimethoxysilane, stir evenly, and obtain the first mixture;

[0016] (3) Add dimethyl diallyl ammonium chloride to water and disperse it evenly to obtain a modified solution;

[0017] (4) The modified liquid is added to the first mixture, stirred evenly, filtered, dried to obtain the precursor, and the precursor is irradiated in an oxygen-free environment to obtain modified shell powder.

[0018] This invention creatively activates and treats seashell powder with silane, then adsorbs dimethyl diallyl ammonium chloride onto the surface of the seashell powder. After irradiation, it is grafted onto the surface of the seashell powder. The grafting of dimethyl diallyl ammonium chloride effectively improves the compatibility of the seashell powder in the system, promotes its migration to the surface, and enables it to be evenly dispersed in the system. Furthermore, the grafting of dimethyl diallyl ammonium chloride further improves the antibacterial effect, combining inorganic and organic antibacterial agents for synergistic antibacterial action.

[0019] In a preferred embodiment of the present invention, the calcination temperature is 150~200℃ and the calcination time is 0.5~2h.

[0020] In a preferred embodiment of the present invention, the concentration of the nitric acid solution is 1~4 mol / L;

[0021] The mass ratio of the calcined shell powder, nitric acid solution, and γ-glycidoxypropyltrimethoxysilane is 1:(4~10):(0.01~0.04).

[0022] In a preferred embodiment of the present invention, the mass ratio of dimethyl diallyl ammonium chloride to water is 1:(4~10).

[0023] The mass ratio of the modified liquid to the first mixture is 1:(4~6).

[0024] In a preferred embodiment of the present invention, the irradiation dose rate is 40~50kGy / h and the irradiation time is 3~5h.

[0025] In a preferred embodiment of the present invention, the defoamer is an organosilicon defoamer, and a representative defoamer is byk066N.

[0026] As a preferred embodiment of the present invention, the leveling agent is an organosilicon twin structure surfactant, and a representative leveling agent is TEGO-4100.

[0027] In a preferred embodiment of the present invention, the wetting agent is a polyether siloxane copolymer type wetting agent, with Wet 280 being a representative example.

[0028] In a preferred embodiment of the present invention, the pigment is at least one of carbon black, titanium dioxide, iron oxide, iron oxide brown, cobalt oxide, phthalocyanine blue, iron oxide yellow, and iron oxide red.

[0029] This invention also provides a method for preparing an environmentally friendly antibacterial coating, comprising the following steps:

[0030] Water-based epoxy emulsion, modified shell powder, diatomaceous earth, pigment, wetting agent, and water are mixed evenly and ground until the particle size is below 40μm. Then, water-based acrylic resin, leveling agent, and defoamer are added and mixed evenly to obtain an environmentally friendly antibacterial coating.

[0031] The beneficial effects of this invention are as follows: This invention creatively incorporates modified shell powder into an aqueous epoxy emulsion, significantly improving its antibacterial effect. The film-forming aid includes a hydroxyl-containing aqueous acrylic resin and diatomaceous earth. The hydroxyl-containing aqueous acrylic resin possesses abundant functional groups and high compatibility, enhancing the compatibility between diatomaceous earth and modified shell powder in the system. Through intermolecular interactions and functional group reactions, it promotes the curing of the coating, fostering the formation of a continuous, uniform, and dense film. Furthermore, due to the charge repulsion between the aqueous acrylic resin and the dimethyl diallyl ammonium chloride groups in the modified shell powder, it promotes the migration of more modified shell powder to the coating surface, resulting in a more uniform dispersion of the shell powder on the coating surface. More effective antibacterial properties; the diatomaceous earth has a microporous structure, which can adsorb and fix resin molecules and pigments in the coating, improve the bonding force between the coating and the substrate (the substrate to which the coating is applied), and make the coating adhere better to the substrate, promoting the formation of a more stable and smoother coating film. The two work together to effectively promote the formation of a smooth, continuous, uniform and dense coating film, improve the compatibility of raw materials in the formulation system, and promote more migration of modified shell powder to the surface. Thus, the use of the specific film-forming aid of the present invention can improve the antibacterial effect to a certain extent (indirectly). In addition, the film-forming aid of the present invention does not use traditional ethers and alcohols, reducing the release of volatile organic compounds and resulting in low VOC emissions. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In this invention, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions that include the listed features.

[0034] In this invention, numerical ranges are involved. Unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe features or characteristics, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0035] In this invention, there are no particular limitations on the specific dispersion and stirring methods.

[0036] Unless otherwise specified, all reagents or instruments used in this invention are commercially available conventional products. Unless otherwise specified, the raw materials used in each comparative example and the parallel experiments of each embodiment are the same commercially available products.

[0037] The raw materials used in the examples and comparative examples are sourced from the following sources:

[0038] Waterborne epoxy emulsion-1: Solid content is 52%, epoxy content is 1050wt%, Guangdong Huaguoshan Environmental Protection Technology, Houxian® EP305.

[0039] Waterborne epoxy emulsion-1: Solid content is 53%, epoxy content is 980wt%, Guangdong Huaguoshan Environmental Protection Technology, Houxian®EP363.

[0040] Defoamer: BYK, BYK066N.

[0041] Leveling agent: TEGO-4100, TEGO Corporation.

[0042] Wetting agent: Evonik, Wet 280.

[0043] Hydroxyl-containing waterborne acrylic resin: solid content 37~39%; viscosity at 25℃ 700~2000mPa·S, hydroxyl content 4.7wt%; Opaldi Resins Company, AC 27401.

[0044] Example 1

[0045] An environmentally friendly antibacterial coating comprises the following components in parts by weight: 50 parts waterborne epoxy emulsion-1, 16 parts modified shell powder, 8 parts film-forming aid, 4 parts titanium dioxide, 3 parts wetting agent, 0.5 parts leveling agent, 0.5 parts defoamer, and 18 parts water.

[0046] The film-forming aid comprises a hydroxyl-containing aqueous acrylic resin and diatomaceous earth, wherein the mass ratio of the aqueous acrylic resin to the diatomaceous earth is 1:0.25.

[0047] The modified seashell powder is prepared by:

[0048] (1) Crush the oyster shells to 200 mesh to obtain shell powder, and calcine the shell powder at 180℃ for 1 hour to obtain calcined shell powder;

[0049] (2) Add the calcined shell powder to a 2 mol / L nitric acid solution and disperse it evenly at 500 rpm. Add γ-glycidoxypropyltrimethoxysilane and stir at 500 rpm for 30 min to obtain the first mixture. The mass ratio of the calcined shell powder, nitric acid solution and γ-glycidoxypropyltrimethoxysilane is 1:6:0.03.

[0050] (3) Dimethyl diallyl ammonium chloride is added to water and dispersed evenly at a speed of 500 rpm to obtain a modified solution; the mass ratio of dimethyl diallyl ammonium chloride to water is 1:6.

[0051] (4) The modified liquid is added dropwise to the first mixture, stirred evenly, filtered, and dried to obtain the precursor. The precursor is then irradiated in an oxygen-free environment to obtain modified shell powder. The mass ratio of the modified liquid to the first mixture is 1:5, the radiation source is Co-60, the irradiation dose rate is 45 kGy / h, and the irradiation time is 4h.

[0052] The preparation method of the aforementioned environmentally friendly antibacterial coating includes the following steps:

[0053] Waterborne epoxy emulsion, modified shell powder, diatomaceous earth, titanium dioxide, wetting agent, and water are mixed evenly and ground until the particle size is below 40μm. Then, waterborne acrylic resin, leveling agent, and defoamer are added and mixed evenly to obtain an environmentally friendly antibacterial coating.

[0054] Example 2

[0055] An environmentally friendly antibacterial coating comprises the following components in parts by weight: 55 parts waterborne epoxy emulsion, 14 parts modified shell powder, 6 parts film-forming aid, 6 parts titanium dioxide, 2 parts wetting agent, 0.8 parts leveling agent, 0.2 parts defoamer, and 16 parts water.

[0056] The film-forming aid comprises a hydroxyl-containing aqueous acrylic resin and diatomaceous earth, wherein the mass ratio of the aqueous acrylic resin to the diatomaceous earth is 1:0.25.

[0057] The modified seashell powder is prepared by:

[0058] (1) Crush the oyster shells to 200 mesh to obtain shell powder, and calcine the shell powder at 180℃ for 1 hour to obtain calcined shell powder;

[0059] (2) Add calcined shell powder to a 2 mol / L nitric acid solution and disperse it evenly at 500 rpm. Add γ-glycidoxypropyltrimethoxysilane and stir at 500 rpm for 30 min to obtain the first mixture. The mass ratio of the calcined shell powder, nitric acid solution and γ-glycidoxypropyltrimethoxysilane is 1:6:0.03.

[0060] (3) Dimethyl diallyl ammonium chloride is added to water and dispersed evenly at a speed of 500 rpm to obtain a modified solution; the mass ratio of dimethyl diallyl ammonium chloride to water is 1:6.

[0061] (4) The modified liquid is added dropwise to the first mixture, stirred evenly, filtered, and dried to obtain the precursor. The precursor is then irradiated in an oxygen-free environment to obtain modified shell powder. The mass ratio of the modified liquid to the first mixture is 1:5, the radiation source is Co-60, the irradiation dose rate is 45 kGy / h, and the irradiation time is 4h.

[0062] The preparation method of the aforementioned environmentally friendly antibacterial coating includes the following steps:

[0063] Waterborne epoxy emulsion, modified shell powder, diatomaceous earth, titanium dioxide, wetting agent, and water are mixed evenly and ground until the particle size is below 40μm. Then, waterborne acrylic resin, leveling agent, and defoamer are added and mixed evenly to obtain an environmentally friendly antibacterial coating.

[0064] Example 3

[0065] An environmentally friendly antibacterial coating comprises the following components in parts by weight: 45 parts waterborne epoxy emulsion, 18 parts modified shell powder, 10 parts film-forming aid, 3 parts titanium dioxide, 4 parts wetting agent, 0.2 parts leveling agent, 0.8 parts defoamer, and 19 parts water.

[0066] The film-forming aid comprises a hydroxyl-containing aqueous acrylic resin and diatomaceous earth, wherein the mass ratio of the aqueous acrylic resin to the diatomaceous earth is 1:0.25.

[0067] The modified seashell powder is prepared by:

[0068] (1) Crush the oyster shells to 200 mesh to obtain shell powder, and calcine the shell powder at 180℃ for 1 hour to obtain calcined shell powder;

[0069] (2) Add the calcined shell powder to a 2 mol / L nitric acid solution and disperse it evenly at 500 rpm. Add γ-glycidoxypropyltrimethoxysilane and stir at 500 rpm for 30 min to obtain the first mixture. The mass ratio of the calcined shell powder, nitric acid solution and γ-glycidoxypropyltrimethoxysilane is 1:6:0.03.

[0070] (3) Dimethyl diallyl ammonium chloride is added to water and dispersed evenly at a speed of 500 rpm to obtain a modified solution; the mass ratio of dimethyl diallyl ammonium chloride to water is 1:6.

[0071] (4) The modified liquid is added dropwise to the first mixture, stirred evenly, filtered, and dried to obtain the precursor. The precursor is then irradiated in an oxygen-free environment to obtain modified shell powder. The mass ratio of the modified liquid to the first mixture is 1:5, the radiation source is Co-60, the irradiation dose rate is 45 kGy / h, and the irradiation time is 4h.

[0072] The preparation method of the aforementioned environmentally friendly antibacterial coating includes the following steps:

[0073] Waterborne epoxy emulsion, modified shell powder, diatomaceous earth, titanium dioxide, wetting agent, and water are mixed evenly and ground until the particle size is below 40μm. Then, waterborne acrylic resin, leveling agent, and defoamer are added and mixed evenly to obtain an environmentally friendly antibacterial coating.

[0074] Example 4

[0075] An environmentally friendly antibacterial coating comprises the following components in parts by weight: 50 parts waterborne epoxy emulsion-2, 16 parts modified shell powder, 8 parts film-forming aid, 4 parts titanium dioxide, 3 parts wetting agent, 0.5 parts leveling agent, 0.5 parts defoamer, and 18 parts water.

[0076] The film-forming aid comprises a hydroxyl-containing aqueous acrylic resin and diatomaceous earth, wherein the mass ratio of the aqueous acrylic resin to the diatomaceous earth is 1:0.25.

[0077] The modified seashell powder is prepared by:

[0078] (1) Crush the oyster shells to 200 mesh to obtain shell powder, and calcine the shell powder at 180℃ for 1 hour to obtain calcined shell powder;

[0079] (2) Add the calcined shell powder to a 2 mol / L nitric acid solution and disperse it evenly at 500 rpm. Add γ-glycidoxypropyltrimethoxysilane and stir at 500 rpm for 30 min to obtain the first mixture. The mass ratio of the calcined shell powder, nitric acid solution and γ-glycidoxypropyltrimethoxysilane is 1:6:0.03.

[0080] (3) Dimethyl diallyl ammonium chloride is added to water and dispersed evenly at a speed of 500 rpm to obtain a modified solution; the mass ratio of dimethyl diallyl ammonium chloride to water is 1:6.

[0081] (4) The modified liquid is added dropwise to the first mixture, stirred evenly, filtered, and dried to obtain the precursor. The precursor is then irradiated in an oxygen-free environment to obtain modified shell powder. The mass ratio of the modified liquid to the first mixture is 1:5, the radiation source is Co-60, the irradiation dose rate is 45 kGy / h, and the irradiation time is 4h.

[0082] The preparation method of the aforementioned environmentally friendly antibacterial coating includes the following steps:

[0083] Waterborne epoxy emulsion, modified shell powder, diatomaceous earth, titanium dioxide, wetting agent, and water are mixed evenly and ground until the particle size is below 40μm. Then, waterborne acrylic resin, leveling agent, and defoamer are added and mixed evenly to obtain an environmentally friendly antibacterial coating.

[0084] Example 5

[0085] An environmentally friendly antibacterial coating comprises the following components in parts by weight: 50 parts waterborne epoxy emulsion-2, 16 parts modified shell powder, 8 parts film-forming aid, 4 parts titanium dioxide, 3 parts wetting agent, 0.5 parts leveling agent, 0.5 parts defoamer, and 18 parts water.

[0086] The film-forming aid includes a hydroxyl-containing aqueous acrylic resin and diatomaceous earth, wherein the mass ratio of the aqueous acrylic resin to the diatomaceous earth is 1:0.5.

[0087] The modified seashell powder is prepared by:

[0088] (1) Crush the oyster shells to 200 mesh to obtain shell powder, and calcine the shell powder at 180℃ for 1 hour to obtain calcined shell powder;

[0089] (2) Add the calcined shell powder to a 2 mol / L nitric acid solution and disperse it evenly at 500 rpm. Add γ-glycidoxypropyltrimethoxysilane and stir at 500 rpm for 30 min to obtain the first mixture. The mass ratio of the calcined shell powder, nitric acid solution and γ-glycidoxypropyltrimethoxysilane is 1:6:0.03.

[0090] (3) Dimethyl diallyl ammonium chloride is added to water and dispersed evenly at a speed of 500 rpm to obtain a modified solution; the mass ratio of dimethyl diallyl ammonium chloride to water is 1:6.

[0091] (4) The modified liquid is added dropwise to the first mixture, stirred evenly, filtered, and dried to obtain the precursor. The precursor is then irradiated in an oxygen-free environment to obtain modified shell powder. The mass ratio of the modified liquid to the first mixture is 1:5, the radiation source is Co-60, the irradiation dose rate is 45 kGy / h, and the irradiation time is 4h.

[0092] The preparation method of the aforementioned environmentally friendly antibacterial coating includes the following steps:

[0093] Waterborne epoxy emulsion, modified shell powder, diatomaceous earth, titanium dioxide, wetting agent, and water are mixed evenly and ground until the particle size is below 40μm. Then, waterborne acrylic resin, leveling agent, and defoamer are added and mixed evenly to obtain an environmentally friendly antibacterial coating.

[0094] Example 6

[0095] An environmentally friendly antibacterial coating comprises the following components in parts by weight: 50 parts waterborne epoxy emulsion-2, 16 parts modified shell powder, 8 parts film-forming aid, 4 parts titanium dioxide, 3 parts wetting agent, 0.5 parts leveling agent, 0.5 parts defoamer, and 18 parts water.

[0096] The film-forming aid comprises a hydroxyl-containing aqueous acrylic resin and diatomaceous earth, wherein the mass ratio of the aqueous acrylic resin to the diatomaceous earth is 1:0.2.

[0097] The modified seashell powder is prepared by:

[0098] (1) Crush the oyster shells to 200 mesh to obtain shell powder, and calcine the shell powder at 180℃ for 1 hour to obtain calcined shell powder;

[0099] (2) Add the calcined shell powder to a 2 mol / L nitric acid solution and disperse it evenly at 500 rpm. Add γ-glycidoxypropyltrimethoxysilane and stir at 500 rpm for 30 min to obtain the first mixture. The mass ratio of the calcined shell powder, nitric acid solution and γ-glycidoxypropyltrimethoxysilane is 1:6:0.03.

[0100] (3) Dimethyl diallyl ammonium chloride is added to water and dispersed evenly at a speed of 500 rpm to obtain a modified solution; the mass ratio of dimethyl diallyl ammonium chloride to water is 1:6.

[0101] (4) The modified liquid is added dropwise to the first mixture, stirred evenly, filtered, and dried to obtain the precursor. The precursor is then irradiated in an oxygen-free environment to obtain modified shell powder. The mass ratio of the modified liquid to the first mixture is 1:5, the radiation source is Co-60, the irradiation dose rate is 45 kGy / h, and the irradiation time is 4h.

[0102] The preparation method of the aforementioned environmentally friendly antibacterial coating includes the following steps:

[0103] Waterborne epoxy emulsion, modified shell powder, diatomaceous earth, titanium dioxide, wetting agent, and water are mixed evenly and ground until the particle size is below 40μm. Then, waterborne acrylic resin, leveling agent, and defoamer are added and mixed evenly to obtain an environmentally friendly antibacterial coating.

[0104] Comparative Example 1

[0105] The difference between Comparative Example 1 and Example 1 is that the film-forming aid in Comparative Example 1 is a single hydroxyl-containing aqueous acrylic resin, while all other aspects are the same.

[0106] An environmentally friendly antibacterial coating comprises the following components in parts by weight: 50 parts waterborne epoxy emulsion-1, 16 parts modified shell powder, 8 parts film-forming aid, 4 parts titanium dioxide, 3 parts wetting agent, 0.5 parts leveling agent, 0.5 parts defoamer, and 18 parts water.

[0107] The film-forming aid is a waterborne acrylic resin containing hydroxyl groups.

[0108] Comparative Example 2

[0109] The difference between Comparative Example 2 and Example 1 is that the film-forming aid in Comparative Example 2 is a single diatomaceous earth, while everything else is the same.

[0110] An environmentally friendly antibacterial coating comprises the following components in parts by weight: 50 parts waterborne epoxy emulsion-1, 16 parts modified shell powder, 8 parts film-forming aid, 4 parts titanium dioxide, 3 parts wetting agent, 0.5 parts leveling agent, 0.5 parts defoamer, and 18 parts water.

[0111] The film-forming aid is diatomaceous earth.

[0112] Comparative Example 3

[0113] The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 uses a dodecyl alcohol ester instead of a hydroxyl-containing aqueous acrylic resin, while all other aspects are the same.

[0114] An environmentally friendly antibacterial coating comprises the following components in parts by weight: 50 parts waterborne epoxy emulsion-1, 16 parts modified shell powder, 8 parts film-forming aid, 4 parts titanium dioxide, 3 parts wetting agent, 0.5 parts leveling agent, 0.5 parts defoamer, and 18 parts water.

[0115] The film-forming aid comprises dodecyl alcohol ester and diatomaceous earth, wherein the mass ratio of dodecyl alcohol ester to diatomaceous earth is 1:0.25.

[0116] Comparative Example 4

[0117] The difference between Comparative Example 4 and Example 1 is that Comparative Example 4 uses shell powder instead of modified shell powder, but everything else is the same.

[0118] An environmentally friendly antibacterial coating comprises the following components in parts by weight: 50 parts waterborne epoxy emulsion-1, 16 parts shell powder, 8 parts film-forming aid, 4 parts titanium dioxide, 3 parts wetting agent, 0.5 parts leveling agent, 0.5 parts defoamer, and 18 parts water.

[0119] The film-forming aid comprises a hydroxyl-containing aqueous acrylic resin and diatomaceous earth, wherein the mass ratio of the aqueous acrylic resin to the diatomaceous earth is 1:0.25.

[0120] The method for preparing the shell powder is as follows:

[0121] (1) Crush the oyster shells to 200 mesh and calcine them at 180°C for 1 hour to obtain shell powder.

[0122] Comparative Example 5

[0123] The difference between Comparative Example 5 and Example 1 is that the preparation method of the modified shell powder in Comparative Example 5 is different from that in Example 1, but all other aspects are the same.

[0124] The modified seashell powder is prepared by:

[0125] (1) Crush the oyster shells to 200 mesh to obtain shell powder, and calcine the shell powder at 180℃ for 1 hour to obtain calcined shell powder;

[0126] (2) Add calcined shell powder to a 2 mol / L nitric acid solution and disperse it evenly at 500 rpm. Add γ-glycidoxypropyltrimethoxysilane and stir at 500 rpm for 30 min to obtain the first mixture. Filter and dry to obtain modified shell powder. The mass ratio of calcined shell powder, nitric acid solution and γ-glycidoxypropyltrimethoxysilane is 1:6:0.03.

[0127] Comparative Example 6

[0128] The difference between Comparative Example 6 and Example 1 is that the preparation method of the modified shell powder in Comparative Example 6 is different from that in Example 1, but all other aspects are the same.

[0129] The modified seashell powder is prepared by:

[0130] (1) Crush the oyster shells to 200 mesh to obtain shell powder, and calcine the shell powder at 180℃ for 1 hour to obtain calcined shell powder;

[0131] (2) Add the calcined shell powder to a 2 mol / L nitric acid solution and disperse it evenly at 500 rpm. Add γ-glycidoxypropyltrimethoxysilane and stir at 500 rpm for 30 min to obtain the first mixture. The mass ratio of the calcined shell powder, nitric acid solution and γ-glycidoxypropyltrimethoxysilane is 1:6:0.03.

[0132] (3) Dimethyl diallyl ammonium chloride is added to water and dispersed evenly at a speed of 500 rpm to obtain a modified solution; the mass ratio of dimethyl diallyl ammonium chloride to water is 1:6.

[0133] (4) Add the modified liquid dropwise into the first mixture, stir evenly, filter, and dry to obtain modified seashell powder. The mass ratio of the modified liquid to the first mixture is 1:5.

[0134] Test case

[0135] The antibacterial rate and antibacterial durability were tested according to GB / T 21866-2008, and the test strain was Escherichia coli ATCC25922.

[0136] Table 1

[0137]

[0138] As can be seen from Table 1, the coating described in this invention has excellent antibacterial effect and good antibacterial durability.

[0139] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An environmentally friendly antibacterial coating, characterized in that, It comprises the following components in parts by weight: 45-55 parts waterborne epoxy emulsion, 14-18 parts modified shell powder, 6-10 parts film-forming aid, 3-6 parts pigment, 2-4 parts wetting agent, 0.2-0.8 parts leveling agent, 0.2-0.8 parts defoamer, and 15-20 parts water; The film-forming aid includes a hydroxyl-containing aqueous acrylic resin and diatomaceous earth, wherein the mass ratio of the aqueous acrylic resin to diatomaceous earth is 1:(0.2~0.5). The modified seashell powder is prepared by: (1) Crush oyster shells to 50-400 mesh to obtain shell powder, calcine the shell powder to obtain calcined shell powder; the calcination temperature is 150-200℃ and the calcination time is 0.5-2h; (2) Add the calcined shell powder to the nitric acid solution, disperse it evenly, add γ-glycidoxypropyltrimethoxysilane, stir evenly to obtain the first mixture; the mass ratio of the calcined shell powder, nitric acid solution and γ-glycidoxypropyltrimethoxysilane is 1:(4~10):(0.01~0.04). (3) Dimethyl diallyl ammonium chloride is added to water and dispersed evenly to obtain a modified solution. The mass ratio of dimethyl diallyl ammonium chloride to water is 1: (4~10). (4) The modified liquid is added dropwise into the first mixture, stirred evenly, filtered, dried to obtain the precursor, and the precursor is irradiated in an oxygen-free environment to obtain modified shell powder. The mass ratio of the modified liquid to the first mixture is 1:(4~6), the irradiation dose rate is 40~50kGy / h, and the irradiation time is 3~5h.

2. The environmentally friendly antibacterial coating according to claim 1, characterized in that, The product comprises the following components in parts by weight: 50 parts waterborne epoxy emulsion, 16 parts modified shell powder, 8 parts film-forming aid, 4 parts pigment, 3 parts wetting agent, 0.5 parts leveling agent, 0.5 parts defoamer, and 18 parts water.

3. The environmentally friendly antibacterial coating according to claim 1, characterized in that, The aqueous epoxy emulsion has a solid content of 52-53% and an epoxy equivalent of 950-1050 g / eq.

4. The environmentally friendly antibacterial coating according to claim 1, characterized in that, The solid content of the hydroxyl-containing waterborne acrylic resin is 37-39%; the viscosity of the hydroxyl-containing waterborne acrylic resin at 25°C is 700-2000 mPa·s; and the hydroxyl content of the hydroxyl-containing waterborne acrylic resin is 4.6-4.8 wt%.

5. The environmentally friendly antibacterial coating according to claim 1, characterized in that, The concentration of the nitric acid solution is 1~4 mol / L.

6. The method for preparing the environmentally friendly antibacterial coating according to any one of claims 1 to 5, characterized in that, Includes the following steps: Waterborne epoxy emulsion, modified shell powder, diatomaceous earth, pigment, wetting agent, and water are mixed evenly and ground until the particle size is below 40μm. Then, waterborne acrylic resin containing hydroxyl groups, leveling agent, and defoamer are added and mixed evenly to obtain an environmentally friendly antibacterial coating.

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