Mildew-proof antibacterial water-based paint and preparation method thereof

Abstract

The invention discloses a mildew-proof and antibacterial water-based coating and a preparation method thereof, and belongs to the technical field of coatings. The water-based paint is prepared from the following raw materials: 60 to 70 parts of emulsion, 15 to 25 parts of auxiliaries, 6 to 12 parts of deionized water, 3 to 8 parts of coalescing agent, 2 to 5 parts of dispersing agent, 2 to 4 parts of pigment, 0.5 to 1 part of defoaming agent, 0.5 to 1 part of flatting agent, 0.2 to 0.8 part of wetting agent, 0.1 to 1 part of thickening agent, 0.1 to 0.5 part of pH regulator and 0.05 to 0.1 part of initiator. Nano titanium dioxide, talcum powder, a sulfadimidine structure and an organosilicon quaternary ammonium salt structure in the auxiliary agent have a synergistic effect, so that the auxiliary agent has excellent antibacterial property and ultraviolet resistance, the compatibility between the auxiliary agent and other raw materials is good, and chemical action exists between the auxiliary agent and an emulsion, so that the auxiliary agent is not easy to migrate and fall off and can play a role to the maximum extent, and the service life of the auxiliary agent is prolonged. Therefore, the water-based paint disclosed by the invention is endowed with efficient and lasting antibacterial performance and anti-ultraviolet performance.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to a mildew-proof and antibacterial water-based coating and a preparation method thereof. Background Art

[0002] Paints are widely used in construction and daily life to protect, decorate or mark the surfaces of building materials, furniture or toys. Paints are divided into oil-based paints and water-based paints. Since oil-based paints easily volatilize harmful substances and affect human health, water-based paints are increasingly used.

[0003] However, water-based paint contains water, which can easily breed bacteria, affecting the appearance and use of the paint, and more seriously affecting health. At present, mildew and antibacterial agents are usually added to the paint to reduce bacterial growth. This method is simple to apply and widely used, but mildew and antibacterial agents in the prior art are mostly added to the system in a physical way, which has the disadvantages of easy migration and short-lasting effect, and cannot meet the market requirements. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a mildew and antibacterial water-based paint and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A mildew-proof and antibacterial water-based paint comprises the following raw materials in parts by weight: 60-70 parts of emulsion, 15-25 parts of additives, 6-12 parts of deionized water, 3-8 parts of film-forming additives, 2-5 parts of dispersants, 2-4 parts of pigments, 0.5-1 parts of defoamers, 0.5-1 parts of leveling agents, 0.2-0.8 parts of wetting agents, 0.1-1 parts of thickeners, 0.1-0.5 parts of pH regulators, and 0.05-0.1 parts of initiators.

[0006] Furthermore, the emulsion is one of styrene-acrylic emulsion, silicone-acrylic emulsion and pure acrylic emulsion.

[0007] Furthermore, the auxiliary agent is prepared by the following steps: S1. Add trimethylolpropane triacrylate, DBU (1,8-diazobisspiro[5.4.0]undec-7-ene) and dimethyl sulfoxide into a dry three-necked flask, stir and dissolve, then heat to 65°C, slowly add a mixed solution of meglumine and dimethyl sulfoxide under nitrogen protection, keep warm at 65°C for 24h after the addition, cool to room temperature after the reaction, and distill under reduced pressure to obtain intermediate 1; the amount ratio of trimethylolpropane triacrylate, meglumine, DBU and dimethyl sulfoxide is 29mL:19.5g:3mL:200mL; Under the catalytic action of DBU, the molar ratio of trimethylolpropane triacrylate to meglumine is controlled to be 1.05-1.1:1, and trimethylolpropane triacrylate and meglumine undergo Michael addition reaction under heating. The reaction process is as follows:

[0008] S2, nitrogen was blown into a dry three-necked flask to expel air and moisture in the flask, and then intermediate 1, pyridine and dimethyl sulfoxide were added, stirred and dissolved, and the temperature was raised to 60°C, and 3-chloropropyltrimethoxysilane was slowly added. After the addition was completed, the temperature was kept at 60°C for 3 hours. After the reaction was completed, the mixture was cooled to room temperature and distilled under reduced pressure to obtain intermediate 2; the usage ratio of intermediate 1, 3-chloropropyltrimethoxysilane, pyridine and dimethyl sulfoxide was 39.4g:15.9mL:7.8mL:220mL; Pyridine is used as an acid binding agent, and the molar ratio of intermediate 1 and 3-chloropropyltrimethoxysilane is controlled to be 1:1.05-1.1. The -NH- of intermediate 1 and the -Cl of 3-chloropropyltrimethoxysilane undergo a substitution reaction under heating. The reaction process is shown below:

[0009] S3, add intermediate 2, DBU (1,8-diazobisspiro[5.4.0]undec-7-ene) and DMF (N,N-dimethylformamide) into a dry brown three-necked flask, stir to dissolve and then heat to 70°C, then slowly add a mixed solution of sulfadimethoxine and DMF, keep warm at 70°C for 24h after the addition is complete, cool to room temperature after the reaction is completed, and distill under reduced pressure to obtain intermediate 3; the usage ratio of intermediate 2, sulfadimethoxine, DBU and DMF is 41.4g:17.2g:1.8mL:240mL; Under the catalytic effect of DBU, the molar ratio of intermediate 2 to sulfamethazine is controlled to be 1:1-1.05, and intermediate 2 and sulfamethazine undergo Michael addition reaction under heating. The reaction process is as follows:

[0010] S4. Evenly mix nano titanium dioxide, talcum powder and deionized water in a three-necked flask, then slowly add glacial acetic acid to adjust the pH to 4, then slowly add the mixed solution of intermediate 3 and DMF while stirring, heat to 65°C after the addition is completed, keep warm for 1 hour, cool to room temperature after the reaction is completed, centrifuge, take the lower layer of precipitate after centrifugation, ultrasonically disperse it in anhydrous ethanol for 1 hour, and finally dry it at 80°C for 12 hours to obtain an auxiliary agent; the dosage ratio of nano titanium dioxide, talcum powder, intermediate 3, DMF and deionized water is 20g:20g:4g:20mL:250mL.

[0011] The surfaces of nano-titanium dioxide and talcum powder are rich in hydroxyl groups. The silaneoxy groups on the surface of the intermediate 3 are hydrolyzed under heating and acidic conditions to form chemical bonds with the hydroxyl groups on the surfaces of the nano-titanium dioxide and talcum powder, thereby finally obtaining an additive.

[0012] The additive contains nano titanium dioxide and talcum powder. Nano titanium dioxide can give the additive good antibacterial and UV resistance; adding additives containing talcum powder to the paint can increase the hardness, wear resistance and adhesion of the paint, making the paint more weather-resistant and durable.

[0013] The additive contains sulfadimethoxine structure, which is a broad-spectrum antibacterial agent. It can compete with p-aminobenzoic acid on difolate synthase in bacteria, thereby preventing p-aminobenzoic acid from being used as a raw material to synthesize folic acid required by bacteria, and reducing the amount of metabolically active tetrahydrofolate, which is an essential substance for bacteria to synthesize purines, thymidine and deoxyribonucleic acid. Therefore, the sulfadimethoxine structure can inhibit the growth and reproduction of bacteria.

[0014] The additive contains organosilicon quaternary ammonium salt structure, which uses organosilicon as a medium to strongly adsorb the ammonium cation group with bactericidal properties on the surface of bacteria, change the permeability of bacterial cell walls, and make the enzymes, coenzymes and metabolic intermediates in the bacteria overflow, causing the microorganisms to stop breathing and die, thereby achieving the effect of bactericidal and antibacterial. Organosilicon quaternary ammonium salt structure is resistant to high temperatures and has a wide range of antibacterial properties, and can effectively inhibit Gram-positive bacteria, Gram-negative bacteria, yeasts and fungi.

[0015] The inorganic components and organic components in the additives work synergistically, so that the water-based paint of the present invention has excellent antibacterial and anti-ultraviolet properties.

[0016] The auxiliary agent contains abundant hydroxyl groups, which can produce hydrogen bonding with hydroxyl groups in raw materials such as deionized water, so that the auxiliary agent can be uniformly dispersed in the water-based paint. The auxiliary agent contains terminal carbon-carbon double bonds, which can produce chemical reactions with unreacted carbon-carbon double bonds in the emulsion under the action of an initiator during the curing process, so that the auxiliary agent can stably exist in the water-based paint. There is a chemical reaction between the auxiliary agent of the present invention and the raw materials in the system, so the auxiliary agent can be highly dispersed and exist in the water-based paint for a long time, is not easy to migrate and come out, and fully exerts its function, so that the water-based paint of the present invention has efficient and lasting antibacterial and anti-ultraviolet properties.

[0017] Furthermore, the film-forming aid is one or more of polyethylene glycol, propylene glycol phenyl ether, and dodecyl alcohol ester.

[0018] Furthermore, the dispersant is one or more of SN-5040 dispersant, SN-5027 dispersant, sodium polyphosphate, and potassium tripolyphosphate.

[0019] Furthermore, the pigment is one or more of iron oxide red, iron oxide black, iron oxide brown, phthalocyanine blue, phthalocyanine green, and permanent yellow.

[0020] Furthermore, the defoaming agent is one or more of a mineral oil defoaming agent and a polysiloxane defoaming agent.

[0021] Furthermore, the leveling agent is one or more of BYK-346 leveling agent, BYK-333 leveling agent, BYK-349 leveling agent, and BYK-381 leveling agent.

[0022] Furthermore, the wetting agent is one or more of HY-1600 wetting agent, HY-1608 wetting agent, HY-1608A wetting agent, HY-352 wetting agent, and HY-6170 wetting agent.

[0023] Furthermore, the thickener is one or more associative polyurethane thickeners.

[0024] Furthermore, the pH regulator is 2-amino-2-methyl-1-propanol.

[0025] Furthermore, the initiator is one or more of di-tert-butyl peroxide, diisopropylbenzene peroxide, and benzoyl peroxide.

[0026] A method for preparing a mildew-proof and antibacterial water-based coating comprises the following steps: Weigh each raw material by weight; first, stir the emulsion, auxiliary agent, initiator and 20% deionized water to obtain a mixed solution for use; then add a wetting agent, a dispersant, a defoaming agent and 80% deionized water to the mixed solution and stir evenly; then add a film-forming auxiliary agent, a leveling agent, a thickener and a pH adjuster and stir evenly; finally, add a pigment and adjust the viscosity to 65-90KU to prepare a mildew-proof and antibacterial water-based coating.

[0027] The beneficial effects of the present invention are as follows: the inorganic components (nano titanium dioxide, talc) and the organic components (sulfamethazine structure, organosilicon quaternary ammonium salt structure) in the auxiliary agent are combined into one by covalent bonds and work synergistically, so that the auxiliary agent has excellent antibacterial and anti-ultraviolet properties. In addition, the auxiliary agent has good compatibility with other raw materials of the water-based coating, and there is a chemical reaction between the auxiliary agent and the emulsion. Therefore, the auxiliary agent of the present invention can be highly dispersed and stably present in the water-based coating, is not easy to migrate and come out, and plays a role to the maximum extent, thereby giving the water-based coating of the present invention efficient and lasting antibacterial and anti-ultraviolet properties. DETAILED DESCRIPTION

[0028] 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 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. Example 1

[0029] Preparation of auxiliary agent, the specific steps are as follows: S1, add 29mL trimethylolpropane triacrylate, 3mL DBU and 140mL dimethyl sulfoxide into a 500mL dry three-necked flask, stir and dissolve, then heat to 65°C, then slowly add a mixed solution of 19.5g meglumine and 60mL dimethyl sulfoxide under nitrogen protection, keep warm at 65°C for 24h after the addition, cool to room temperature after the reaction, and distill under reduced pressure to obtain intermediate 1; S2. Blow nitrogen into a 500 mL dry three-necked flask to expel air and moisture from the flask, then add 39.4 g of intermediate 1, 7.8 mL of pyridine and 220 mL of dimethyl sulfoxide, stir to dissolve, then heat to 60°C, then slowly add 15.9 mL of 3-chloropropyltrimethoxysilane, and continue to react at 60°C for 3 h after the addition is completed. After the reaction is completed, cool to room temperature, and distill under reduced pressure to obtain intermediate 2; S3, add 41.4g of intermediate 2, 1.8mL of DBU and 180mL of DMF into a 500mL dry brown three-necked flask, stir to dissolve and then heat to 70°C, then slowly add 17.2g of sulfadimethoxine and 60mL of DMF, keep warm at 70°C for 24h after the addition is complete, cool to room temperature after the reaction is completed, and distill under reduced pressure to obtain intermediate 3; S4. Mix 20g of nano titanium dioxide, 20g of talcum powder and 250mL of deionized water in a 500mL three-necked flask, then slowly add glacial acetic acid to adjust the pH to 4, then slowly add 4g of intermediate 3 and 20mL of DMF while stirring. After the addition is completed, heat to 65°C and keep the reaction for 1h. After the reaction is completed, cool to room temperature and centrifuge. After centrifugation, take the lower layer of precipitate and ultrasonically disperse it in anhydrous ethanol for 1h, and finally dry it at 80°C for 12h to obtain an auxiliary agent. Example 2

[0030] Preparation of auxiliary agent, the specific steps are as follows: The remaining steps remain unchanged, only steps S1 to S3 of Example 1 are removed, and the intermediate 3 in step S4 is modified to 3-aminopropyltrimethoxysilane to prepare an auxiliary agent. Example 3

[0031] The preparation of mildew-proof and antibacterial water-based coatings is carried out in the following specific steps: Weigh each raw material by weight; first, stir 60 parts of styrene-acrylic emulsion, 15 parts of the auxiliary agent prepared in Example 1, 0.05 parts of dicumyl peroxide and 1.2 parts of deionized water to obtain a mixed solution for use; then add 0.2 parts of HY-1600 wetting agent, 2 parts of SN-5040 dispersant, 0.5 parts of Tego Foamex 825 defoaming agent and 4.8 parts of deionized water to the mixed solution and stir evenly; then add 3 parts of polyethylene glycol 200, 0.5 parts of BYK-346 leveling agent, 0.1 parts of Rheolate 210 thickener and 0.1 parts of 2-amino-2-methyl-1-propanol and stir evenly; finally, add 2 parts of phthalocyanine blue and adjust the viscosity to 65-90KU to prepare a mildew-proof and antibacterial water-based coating. Example

[0032] The preparation of mildew-proof and antibacterial water-based coatings is carried out in the following specific steps: Weigh each raw material by weight; first, stir 65 parts of silicone acrylic emulsion, 20 parts of the additive prepared in Example 1, 0.08 parts of benzoyl peroxide and 2 parts of deionized water to obtain a mixed solution for use; then add 0.6 parts of HY-1608 wetting agent, 4 parts of sodium polyphosphate, 0.8 parts of Surfynol MD 20 defoaming agent and 8 parts of deionized water to the mixed solution and stir evenly; then add 8 parts of propylene glycol phenyl ether, 0.8 parts of BYK-349 leveling agent, 0.3 parts of Borchi Gel 0434 thickener, 0.3 parts of TegoViscoPlus 3010 thickener and 0.3 parts of 2-amino-2-methyl-1-propanol and stir evenly; finally, add 3 parts of red iron oxide and adjust the viscosity to 65-90KU to prepare a mildew-proof and antibacterial water-based coating. Example 4

[0033] The preparation of mildew-proof and antibacterial water-based coatings is carried out in the following specific steps: Weigh each raw material by weight; first, stir 70 parts of pure acrylic emulsion, 25 parts of the auxiliary agent prepared in Example 1, 0.1 part of di-tert-butyl peroxide and 2.4 parts of deionized water to obtain a mixed solution for use; then add 0.4 parts of HY-1608 wetting agent, 0.4 parts of HY-6170 wetting agent, 2 parts of SN-5027 dispersant, 3 parts of potassium tripolyphosphate, 0.5 parts of Surfynol MD 20 defoamer, 0.5 parts of Agitan 315 defoamer and 9.6 parts of deionized water to the mixed solution and stir evenly; then add 4 parts of polyethylene glycol 400, 4 parts of dodecyl alcohol ester, 0.5 parts of BYK-333 leveling agent, 0.5 parts of BYK-381 leveling agent, 1 part of Tego ViscoPlus 3010 thickener and 0.5 parts of 2-amino-2-methyl-1-propanol were stirred evenly; finally, 4 parts of permanent yellow were added and the viscosity was adjusted to 65-90 KU to prepare a mildew-proof and antibacterial water-based coating.

[0034] Comparative Example 1 The specific steps for preparing water-based coatings are as follows: The remaining steps remain unchanged, only the auxiliary agent in Example 3 is replaced by the auxiliary agent prepared in Example 2 to prepare the water-based coating.

[0035] Comparative Example 2 The specific steps for preparing water-based coatings are as follows: The remaining steps remain unchanged, and only the auxiliary agent in Example 3 is replaced by 13.5 parts of the auxiliary agent prepared in Example 2, 0.75 parts of sulfadimethoxine, and 0.75 parts of didodecyldimethylammonium chloride to prepare a water-based coating.

[0036] Performance Testing The water-based coatings prepared in Examples 3-5 and Comparative Examples 1-2 were sprayed on the surface of the strip samples, respectively, and the antibacterial performance test was carried out according to GB / T21866-2008 "Antibacterial Property Determination Method and Antibacterial Effect of Antibacterial Coatings (Paint Films)" to obtain the antibacterial rate. The test results are shown in Table 1 below: Table 1

[0037] The water-based coatings prepared in Examples 3-5 and Comparative Examples 1-2 were subjected to the following performance tests, and the test results are shown in Table 2 below: Table 2

[0038] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0039] The above contents are merely examples and explanations of the present invention. Those skilled in the art 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 invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A mildew and antibacterial water-based paint, characterized in that: The invention comprises the following raw materials in parts by weight: 60-70 parts of emulsion, 15-25 parts of auxiliary agent, 6-12 parts of deionized water, 3-8 parts of film-forming auxiliary agent, 2-5 parts of dispersant, 2-4 parts of pigment, 0.5-1 parts of defoamer, 0.5-1 parts of leveling agent, 0.2-0.8 parts of wetting agent, 0.1-1 parts of thickener, 0.1-0.5 parts of pH regulator and 0.05-0.1 parts of initiator; Wherein, the auxiliary agent is prepared by the following steps: S1, trimethylolpropane triacrylate, 1,8-diazobisspiro[5.4.0]undec-7-ene and dimethyl sulfoxide were added into a flask, heated to 65°C with stirring, meglumine and dimethyl sulfoxide were added, reacted for 24 hours, cooled, and distilled under reduced pressure to obtain intermediate 1; S2, after nitrogen blowing into the flask, add intermediate 1, pyridine and dimethyl sulfoxide, stir and heat to 60°C, add 3-chloropropyltrimethoxysilane, react for 3h, cool, and distill under reduced pressure to obtain intermediate 2; S3, add intermediate 2, 1,8-diazobispiro[5.4.0]undec-7-ene and DMF into a flask, heat to 70°C, add sulfadimethoxine and DMF, react for 24 hours, cool, and distill under reduced pressure to obtain intermediate 3; S4. Mix nano titanium dioxide, talcum powder and deionized water in a flask, adjust the pH to 4, add intermediate 3 and DMF, heat to 65°C for reaction for 1 hour, cool, centrifuge, take the precipitate, ultrasonically disperse it in anhydrous ethanol, and dry it to obtain an auxiliary agent.

2. The mildew-proof and antibacterial water-based paint according to claim 1, characterized in that: The amount ratio of trimethylolpropane triacrylate, meglumine, DBU and dimethyl sulfoxide in step S1 is 29mL:19.5g:3mL:200mL; the amount ratio of intermediate 1, 3-chloropropyltrimethoxysilane, pyridine and dimethyl sulfoxide in step S2 is 39.4g:15.9mL:7.8mL:220mL; the amount ratio of intermediate 2, sulfadimethoxine, DBU and DMF in step S3 is 41.4g:17.2g:1.8mL:240mL; the amount ratio of nano titanium dioxide, talc, intermediate 3, DMF and deionized water in step S4 is 20g:20g:4g:20mL:250mL.

3. The mildew-proof and antibacterial water-based paint according to claim 1, characterized in that: The emulsion is one of styrene acrylic emulsion, silicone acrylic emulsion and pure acrylic emulsion.

4. The mildew-proof and antibacterial water-based paint according to claim 1, characterized in that: The film-forming aid is one or more of polyethylene glycol, propylene glycol phenyl ether, and dodecyl alcohol ester; the dispersant is one or more of SN-5040 dispersant, SN-5027 dispersant, sodium polyphosphate, and potassium tripolyphosphate.

5. The mildew-proof and antibacterial water-based paint according to claim 1, characterized in that: The pigment is one or more of iron oxide red, iron oxide black, iron oxide brown, phthalocyanine blue, phthalocyanine green and permanent yellow; the defoamer is one or more of mineral oil defoamers and polysiloxane defoamers.

6. The mildew-proof and antibacterial water-based paint according to claim 1, characterized in that: The leveling agent is one or more of BYK-346 leveling agent, BYK-333 leveling agent, BYK-349 leveling agent, and BYK-381 leveling agent; the wetting agent is one or more of HY-1600 wetting agent, HY-1608 wetting agent, HY-1608A wetting agent, HY-352 wetting agent, and HY-6170 wetting agent.

7. The mildew and antibacterial water-based paint according to claim 1, characterized in that: The thickener is one or more associative polyurethane thickeners.

8. The mildew-proof and antibacterial water-based paint according to claim 1, characterized in that: The pH regulator is 2-amino-2-methyl-1-propanol.

9. The mildew-proof and antibacterial water-based paint according to claim 1, characterized in that: The initiator is one or more of di-tert-butyl peroxide, diisopropylbenzene peroxide and benzoyl peroxide.

10. The method for preparing a mildew-proof and antibacterial water-based coating according to claim 1, characterized in that: The following steps are involved: Weigh each raw material by weight; first, stir the emulsion, auxiliary agent, initiator and 20% deionized water to obtain a mixed solution for use; then add a wetting agent, a dispersant, a defoaming agent and 80% deionized water to the mixed solution and stir evenly; then add a film-forming auxiliary agent, a leveling agent, a thickener and a pH adjuster and stir evenly; finally, add a pigment and adjust the viscosity to 65-90KU to prepare a mildew-proof and antibacterial water-based coating.

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