Stain-resistant self-repairing coating and preparation method thereof

Abstract

The invention provides the field of self-repairing coatings, and particularly discloses a stain-resistant self-repairing coating and a preparation method thereof.The stain-resistant self-repairing coating is prepared from mixed resin, a self-repairing agent, a stain-resistant auxiliary and a plant-based solvent; the preparation method comprises the following steps: weighing the mixed resin, the self-repairing agent, the stain-resistant auxiliary agent and the plant-based solvent in parts by weight for later use; adding deionized water into the mixed resin, and uniformly stirring to obtain a resin solution; the self-repairing agent, the stain-resistant auxiliary agent and the plant-based solvent are sequentially added into the resin solution, mixing and stirring are conducted again, a high-speed dispersion machine is used for coating dispersion after filtering is conducted, and the needed stain-resistant self-repairing coating is obtained and has excellent stain resistance and self-repairing performance.

Description

Technical Field

[0001] The present application relates to the field of self-repairing coatings, and in particular to a stain-resistant self-repairing coating and a preparation method thereof. Background Art

[0002] Anti-fouling self-healing coating is a coating with special properties. It can automatically remove stains after the surface is contaminated, and can self-repair after slight damage. It is usually some substances that can react or undergo physical changes under specific conditions to achieve damage repair. For example, microencapsulated repair agents, when cracks or scratches appear on the coating, the microcapsules rupture to release the repair agent, and the repair agent reacts with the resin to repair; some are based on reversible chemical bond systems, under certain conditions, chemical bonds break and reform to achieve self-repair.

[0003] The long-term use of the anti-fouling self-repairing coating is easily affected by temperature and water, and the coating will age, turn yellow and fall off, which will affect the anti-fouling self-repairing performance of the coating. Based on the above statement, the present application provides a anti-fouling self-repairing coating and a preparation method thereof. Summary of the invention

[0004] The purpose of the present application is to improve the timeliness of the anti-fouling self-repairing performance of the anti-fouling self-repairing coating, and to provide a anti-fouling self-repairing coating and a preparation method thereof compared to the prior art.

[0005] In a first aspect, the present application provides a stain-resistant self-repairing coating, comprising the following raw materials in parts by weight: 80-150 parts of mixed resin, 5-10 parts of self-repairing agent, 5-10 parts of stain-resistant additive, and 1-2 parts of plant-based solvent; The mixed resin is prepared by the following method: According to the mass ratio of 40-50:15-25:20-28:3, organic silicon modified acrylic resin, polyurethane resin, acrylic emulsion and nano zinc oxide are weighed for use, wherein the particle size of the nano zinc oxide particles is 10-30nm, the nano zinc oxide particles are prepared into sol A containing 20%-35% of nano zinc oxide particles, the sol A is mixed with the organic silicon modified acrylic resin, polyurethane resin and acrylic emulsion according to the mass ratio, and the stirring speed is 800-1500r / min. The sol A is combined with the organic silicon modified acrylic resin, polyurethane resin and acrylic emulsion through a sol-gel reaction to form a mixed resin.

[0006] Preferably, the self-healing agent comprises isocyanate microcapsules and nano-silicon dioxide in a mass ratio of 10-15:7.

[0007] Preferably, the isocyanate microcapsules are prepared by the following method: a. Mix formaldehyde, urea and alkaline pH regulator in a mass ratio of 2.5-4.6:3-5:0.05-0.1, and carry out condensation reaction at a pH of 9-10 and a temperature of 65-95°C for 1-5 hours to obtain a urea-formaldehyde resin prepolymer; b. mixing a urea-formaldehyde resin prepolymer with polyoxyethylene octylphenol ether, polyvinyl alcohol and water in a mass ratio of 10:0.1-0.5:0.2-0.4:30 to obtain an aqueous phase; Mixing isocyanate and isocyanate protective agent in a mass ratio of 1-2:0.1-0.15 to obtain an oil phase; emulsifying the water phase and the oil phase to obtain an emulsion; c. Mix the emulsion with an acidic pH regulator, and carry out a curing reaction at a pH of 3-5 and a temperature of 65-80°C for 0.5-2.5 hours to obtain isocyanate microcapsules.

[0008] By adopting the above scheme, the present application uses silicone-modified acrylic resin, polyurethane resin, acrylic emulsion and nano zinc oxide to prepare a mixed resin, which can improve the water resistance, weather resistance and flexibility of traditional resins, and can improve the hardness and wear resistance of the resin, while giving the coating a self-repairing function, thereby improving the performance and aging of the coating; at the same time, the self-repairing agent prepared by isocyanate microcapsules and nano-silica, when the surface of the coating is damaged, the isocyanate microcapsules rupture, releasing isocyanate and nano-silica to achieve self-repair, and at the same time, nano-silica can also fill the micropores in the coating, improve the density and stain resistance of the coating, and further improve the stain resistance and self-repairing properties of the coating.

[0009] Preferably, during the emulsification process of the water phase and the oil phase, mechanical stirring is used for stirring, the stirring speed is 2000 rpm-3500 rpm, and the stirring time is 0.1-0.3 h.

[0010] Preferably, the anti-fouling agent is a mixture of polydimethylsiloxane and nano-titanium dioxide in a mass ratio of 1-2:1.5-2.

[0011] Preferably, the plant-based solvent is a mixture of soybean oil methyl ester and limonene in a mass ratio of 4:3.

[0012] In a second aspect, the present application provides a method for preparing a stain-resistant self-repairing coating, comprising the following preparation steps: S1. Weigh the mixed resin, self-repairing agent, anti-fouling agent and plant-based solvent by weight for later use; S2, adding deionized water to the mixed resin and stirring evenly to obtain a resin solution; S3. Add the self-repairing agent, anti-fouling agent and plant-based solvent to the resin solution in sequence, mix and stir again, filter and then use a high-speed disperser to disperse the coating to obtain the desired anti-fouling self-repairing coating.

[0013] Compared with the prior art, the advantages of the present application are: the present application utilizes silicone-modified acrylic resin, polyurethane resin, acrylic emulsion and nano zinc oxide to prepare a mixed resin, which can improve the water resistance, weather resistance and flexibility of traditional resins, and can improve the hardness and wear resistance of the resin, while giving the coating a self-repairing function, thereby improving the performance and aging of the coating; at the same time, the self-repairing agent prepared by isocyanate microcapsules and nano-silica, when the coating surface is damaged, the isocyanate microcapsules rupture, releasing isocyanate and nano-silica to achieve self-repair, and at the same time, nano-silica can also fill the micropores in the coating, improve the density and stain resistance of the coating, and further improve the stain resistance and self-repairing properties of the coating. DETAILED DESCRIPTION

[0014] The present application is further described in detail below with reference to the embodiments.

[0015] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making any creative work shall fall within the scope of protection of this application.

[0016] Embodiment 1: A stain-resistant self-repairing coating, comprising the following raw materials in parts by weight: 80 parts of mixed resin, 5 parts of self-repairing agent, 5 parts of stain-resistant additive, and 1 part of plant-based solvent; The anti-fouling agent is a mixture of polydimethylsiloxane and nano-titanium dioxide in a mass ratio of 1:1.5, and the plant-based solvent is a mixture of soybean oil methyl ester and limonene in a mass ratio of 4:3.

[0017] The mixed resin is prepared by the following method: Organosilicon-modified acrylic resin, polyurethane resin, acrylic emulsion and nano zinc oxide are weighed and set aside in a mass ratio of 40:15:20:3, wherein the particle size of the nano zinc oxide particles is 10 nm. The nano zinc oxide particles are prepared into a sol A containing 20% ​​of the nano zinc oxide particles. The sol A is mixed with the organosilicon-modified acrylic resin, polyurethane resin and acrylic emulsion in a mass ratio at a stirring speed of 800 r / min. The sol A is combined with the organosilicon-modified acrylic resin, polyurethane resin and acrylic emulsion through a sol-gel reaction to form a mixed resin.

[0018] The self-healing agent includes isocyanate microcapsules and nano-silicon dioxide in a mass ratio of 10:7.

[0019] Furthermore, isocyanate microcapsules are prepared by the following method: a. Mix formaldehyde, urea and alkaline pH regulator in a mass ratio of 2.5:3:0.05, and carry out condensation reaction at a pH of 9 and a temperature of 65°C for 1 hour to obtain a urea-formaldehyde resin prepolymer; b. The urea-formaldehyde resin prepolymer is mixed with polyoxyethylene octylphenol ether, polyvinyl alcohol and water in a mass ratio of 10:0.1:0.2:30 to obtain an aqueous phase; Mixing isocyanate and isocyanate protective agent in a mass ratio of 1:0.1 to obtain an oil phase; Emulsifying the water phase and the oil phase to obtain an emulsion, wherein during the emulsification process of the water phase and the oil phase, mechanical stirring is used for stirring, the stirring speed is 2000 rpm, and the stirring time is 0.1 h; c. The emulsion was mixed with an acidic pH regulator, and a curing reaction was carried out at a pH of 3 and a temperature of 65° C. for 0.5 h to obtain isocyanate microcapsules.

[0020] A method for preparing a stain-resistant self-repairing coating comprises the following preparation steps: S1. Weigh the mixed resin, self-repairing agent, anti-fouling agent and plant-based solvent by weight for later use; S2, adding deionized water to the mixed resin and stirring evenly to obtain a resin solution; S3. Add the self-repairing agent, anti-fouling agent and plant-based solvent to the resin solution in sequence, mix and stir again, filter and then use a high-speed disperser to disperse the coating to obtain the desired anti-fouling self-repairing coating.

[0021] Embodiment 2: A stain-resistant self-repairing coating, comprising the following raw materials in parts by weight: 150 parts of mixed resin, 10 parts of self-repairing agent, 10 parts of stain-resistant additive, and 2 parts of plant-based solvent; The anti-fouling agent is a mixture of polydimethylsiloxane and nano-titanium dioxide in a mass ratio of 2:1.5, and the plant-based solvent is a mixture of soybean oil methyl ester and limonene in a mass ratio of 4:3.

[0022] The mixed resin is prepared by the following method: Organosilicon-modified acrylic resin, polyurethane resin, acrylic emulsion and nano zinc oxide were weighed at a mass ratio of 50:25:28:3 for later use, wherein the particle size of the nano zinc oxide particles was 30 nm. The nano zinc oxide particles were used to prepare a sol A containing 35% of the nano zinc oxide particles. The sol A was mixed with the organosilicon-modified acrylic resin, polyurethane resin and acrylic emulsion at a mass ratio of 1500 r / min. The sol A was combined with the organosilicon-modified acrylic resin, polyurethane resin and acrylic emulsion through a sol-gel reaction to form a mixed resin.

[0023] The self-healing agent includes isocyanate microcapsules and nano-silicon dioxide in a mass ratio of 15:7.

[0024] Furthermore, isocyanate microcapsules are prepared by the following method: a. Mix formaldehyde, urea and an alkaline pH regulator in a mass ratio of 4.6:5:0.1, and carry out a condensation reaction at a pH of 10 and a temperature of 95°C for 5 hours to obtain a urea-formaldehyde resin prepolymer; b. The urea-formaldehyde resin prepolymer is mixed with polyoxyethylene octylphenol ether, polyvinyl alcohol and water in a mass ratio of 10:0.5:0.4:30 to obtain an aqueous phase; Mixing isocyanate and isocyanate protective agent in a mass ratio of 2:0.15 to obtain an oil phase; Emulsifying the water phase and the oil phase to obtain an emulsion, wherein during the emulsification process of the water phase and the oil phase, mechanical stirring is used for stirring, the stirring speed is 3500 rpm, and the stirring time is 0.3 h; c. The emulsion was mixed with an acidic pH regulator, and a curing reaction was carried out at a pH of 5 and a temperature of 80° C. for 2.5 hours to obtain isocyanate microcapsules.

[0025] A method for preparing a stain-resistant self-repairing coating comprises the following preparation steps: S1. Weigh the mixed resin, self-repairing agent, anti-fouling agent and plant-based solvent by weight for later use; S2, adding deionized water to the mixed resin and stirring evenly to obtain a resin solution; S3. Add the self-repairing agent, anti-fouling agent and plant-based solvent to the resin solution in sequence, mix and stir again, filter and then use a high-speed disperser to disperse the coating to obtain the desired anti-fouling self-repairing coating.

[0026] Embodiment 3: A stain-resistant self-repairing coating, comprising the following raw materials in parts by weight: 100 parts of mixed resin, 7 parts of self-repairing agent, 8 parts of stain-resistant additive, and 1 part of plant-based solvent; The anti-fouling agent is a mixture of polydimethylsiloxane and nano-titanium dioxide in a mass ratio of 1.5:2, and the plant-based solvent is a mixture of soybean oil methyl ester and limonene in a mass ratio of 4:3.

[0027] The mixed resin is prepared by the following method: Organosilicon-modified acrylic resin, polyurethane resin, acrylic emulsion and nano zinc oxide are weighed and set aside in a mass ratio of 45:20:24:3, wherein the particle size of the nano zinc oxide particles is 25 nm. The nano zinc oxide particles are prepared into a sol A containing 30% of the nano zinc oxide particles. The sol A is mixed with the organosilicon-modified acrylic resin, polyurethane resin and acrylic emulsion in a mass ratio at a stirring speed of 1000 r / min. The sol A is combined with the organosilicon-modified acrylic resin, polyurethane resin and acrylic emulsion through a sol-gel reaction to form a mixed resin.

[0028] The self-healing agent includes isocyanate microcapsules and nano-silicon dioxide in a mass ratio of 13:7.

[0029] Furthermore, isocyanate microcapsules are prepared by the following method: a. Mix formaldehyde, urea and alkaline pH regulator in a mass ratio of 4:4:0.1, and carry out condensation reaction at a pH of 10 and a temperature of 80°C for 1-5 hours to obtain a urea-formaldehyde resin prepolymer; b. The urea-formaldehyde resin prepolymer is mixed with polyoxyethylene octylphenol ether, polyvinyl alcohol and water in a mass ratio of 10:0.4:0.3:30 to obtain an aqueous phase; Mixing isocyanate and isocyanate protective agent in a mass ratio of 2:0.15 to obtain an oil phase; Emulsifying the water phase and the oil phase to obtain an emulsion, wherein during the emulsification process of the water phase and the oil phase, mechanical stirring is used for stirring, the stirring speed is 3000 rpm, and the stirring time is 0.2 h; c. The emulsion was mixed with an acidic pH regulator, and a curing reaction was carried out at a pH of 4 and a temperature of 70° C. for 2 h to obtain isocyanate microcapsules.

[0030] A method for preparing a stain-resistant self-repairing coating comprises the following preparation steps: S1. Weigh the mixed resin, self-repairing agent, anti-fouling agent and plant-based solvent by weight for later use; S2, adding deionized water to the mixed resin and stirring evenly to obtain a resin solution; S3. Add the self-repairing agent, anti-fouling agent and plant-based solvent to the resin solution in sequence, mix and stir again, filter and then use a high-speed disperser to disperse the coating to obtain the desired anti-fouling self-repairing coating.

[0031] In order to verify the comprehensive performance of the anti-fouling self-repairing coating prepared in Examples 1-3 of the present application, the applicant set up Comparative Examples 1-2, which are as follows: Comparative Example 1: A stain-resistant self-repairing coating, comprising the following raw materials in parts by weight: 80 parts of mixed resin, 5 parts of self-repairing agent, 5 parts of stain-resistant additive, and 1 part of plant-based solvent; The anti-fouling agent is a mixture of polydimethylsiloxane and nano-titanium dioxide in a mass ratio of 1:1.5, and the plant-based solvent is a mixture of soybean oil methyl ester and limonene in a mass ratio of 4:3.

[0032] The mixed resin is silicone-modified acrylic resin.

[0033] The self-healing agent includes isocyanate microcapsules and nano-silicon dioxide in a mass ratio of 10:7.

[0034] Furthermore, isocyanate microcapsules are prepared by the following method: a. Mix formaldehyde, urea and alkaline pH regulator in a mass ratio of 2.5:3:0.05, and carry out condensation reaction at a pH of 9 and a temperature of 65°C for 1 hour to obtain a urea-formaldehyde resin prepolymer; b. The urea-formaldehyde resin prepolymer is mixed with polyoxyethylene octylphenol ether, polyvinyl alcohol and water in a mass ratio of 10:0.1:0.2:30 to obtain an aqueous phase; Mixing isocyanate and isocyanate protective agent in a mass ratio of 1:0.1 to obtain an oil phase; Emulsifying the water phase and the oil phase to obtain an emulsion, wherein during the emulsification process of the water phase and the oil phase, mechanical stirring is used for stirring, the stirring speed is 2000 rpm, and the stirring time is 0.1 h; c. The emulsion was mixed with an acidic pH regulator, and a curing reaction was carried out at a pH of 3 and a temperature of 65° C. for 0.5 h to obtain isocyanate microcapsules.

[0035] A method for preparing a stain-resistant self-repairing coating comprises the following preparation steps: S1. Weigh the mixed resin, self-repairing agent, anti-fouling agent and plant-based solvent by weight for later use; S2, adding deionized water to the mixed resin and stirring evenly to obtain a resin solution; S3. Add the self-repairing agent, anti-fouling agent and plant-based solvent to the resin solution in sequence, mix and stir again, filter and then use a high-speed disperser to disperse the coating to obtain the desired anti-fouling self-repairing coating.

[0036] Comparative Example 2: A stain-resistant self-repairing coating, comprising the following raw materials in parts by weight: 80 parts of mixed resin, 5 parts of self-repairing agent, 5 parts of stain-resistant additive, and 1 part of plant-based solvent; The anti-fouling agent is a mixture of polydimethylsiloxane and nano-titanium dioxide in a mass ratio of 1:1.5, and the plant-based solvent is a mixture of soybean oil methyl ester and limonene in a mass ratio of 4:3.

[0037] The mixed resin is prepared by the following method: Organosilicon-modified acrylic resin, polyurethane resin, acrylic emulsion and nano zinc oxide are weighed and set aside in a mass ratio of 40:15:20:3, wherein the particle size of the nano zinc oxide particles is 10 nm. The nano zinc oxide particles are prepared into a sol A containing 20% ​​of the nano zinc oxide particles. The sol A is mixed with the organosilicon-modified acrylic resin, polyurethane resin and acrylic emulsion in a mass ratio at a stirring speed of 800 r / min. The sol A is combined with the organosilicon-modified acrylic resin, polyurethane resin and acrylic emulsion through a sol-gel reaction to form a mixed resin.

[0038] Among them, the self-healing agent is nano-silicon dioxide.

[0039] A method for preparing a stain-resistant self-repairing coating comprises the following preparation steps: S1. Weigh the mixed resin, self-repairing agent, anti-fouling agent and plant-based solvent by weight for later use; S2, adding deionized water to the mixed resin and stirring evenly to obtain a resin solution; S3. Add the self-repairing agent, anti-fouling agent and plant-based solvent to the resin solution in sequence, mix and stir again, filter and then use a high-speed disperser to disperse the coating to obtain the desired anti-fouling self-repairing coating.

[0040] Performance testing: According to the test standards, the stain-resistant self-healing coatings prepared in Examples 1-3 of the present application and Comparative Examples 1-2 were respectively coated on the surface of the substrate to prepare test specimens, and the test specimens were placed in a test room at a temperature of 25°C and a relative humidity of 55% for 2 hours and then the performance of the specimens was tested.

[0041] According to GB / T 9755-2014 "Synthetic resin emulsion exterior wall paint", the stain resistance index of the test piece after coating was tested, and the coating range of the test piece was 40cmx40cm.

[0042] In accordance with T / SG MY0001-2021 "Self-healing optical thin film coating", the self-healing rate of the specimen was tested, and the specimen specifications were 40cmx40cm.

[0043] The test results are shown in Table 1 below:

[0044]

[0045] It can be seen from the data shown in Table 1 above that the stain-resistant self-repairing coatings prepared in Examples 1-3 of the present application have high stain resistance and self-repairing properties and excellent comprehensive performance.

[0046] It can be seen from the data shown in Example 1 and Comparative Example 1 that Example 1 of the present application prepares a mixed resin by using silicone-modified acrylic resin, polyurethane resin, acrylic emulsion and nano zinc oxide, which can significantly improve the stain resistance of the stain-resistant self-healing coating compared to Comparative Example 1 which directly uses silicone-modified acrylic resin.

[0047] It can be seen from the data shown in Example 1 and Comparative Example 2 that Example 1 of the present application can further enhance the self-repairing ability of the stain-resistant self-repairing coating by pre-preparing isocyanate microcapsules and nano-silica as self-repairing agents.

[0048] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed. However, as long as it is within the scope of the claims of the present application, it shall be protected by the patent law.

Claims

1. A stain-resistant self-repairing coating, It is characterized in that The raw materials include the following parts by weight: 80-150 parts of mixed resin, 5-10 parts of self-repairing agent, 5-10 parts of anti-fouling agent, and 1-2 parts of plant-based solvent; The mixed resin is prepared by the following method: According to the mass ratio of 40-50:15-25:20-28:3, organic silicon modified acrylic resin, polyurethane resin, acrylic emulsion and nano zinc oxide are weighed for use, wherein the particle size of the nano zinc oxide particles is 10-30nm, the nano zinc oxide particles are prepared into sol A containing 20%-35% of nano zinc oxide particles, the sol A is mixed with the organic silicon modified acrylic resin, polyurethane resin and acrylic emulsion according to the mass ratio, and the stirring speed is 800-1500r / min. The sol A is combined with the organic silicon modified acrylic resin, polyurethane resin and acrylic emulsion through a sol-gel reaction to form a mixed resin.

2. A stain-resistant self-repairing coating according to claim 1, It is characterized in that The self-repairing agent comprises isocyanate microcapsules and nano silicon dioxide in a mass ratio of 10-15:

7.

3. A stain-resistant self-repairing coating according to claim 2, It is characterized in that The isocyanate microcapsules are prepared by the following method: a. Mix formaldehyde, urea and alkaline pH regulator in a mass ratio of 2.5-4.6:3-5:0.05-0.1, and carry out condensation reaction at a pH of 9-10 and a temperature of 65-95°C for 1-5 hours to obtain a urea-formaldehyde resin prepolymer; b. mixing a urea-formaldehyde resin prepolymer with polyoxyethylene octylphenol ether, polyvinyl alcohol and water in a mass ratio of 10:0.1-0.5:0.2-0.4:30 to obtain an aqueous phase; Mixing isocyanate and isocyanate protective agent in a mass ratio of 1-2:0.1-0.15 to obtain an oil phase; emulsifying the water phase and the oil phase to obtain an emulsion; c. Mix the emulsion with an acidic pH regulator, and carry out a curing reaction at a pH of 3-5 and a temperature of 65-80°C for 0.5-2.5 hours to obtain isocyanate microcapsules.

4. A stain-resistant self-repairing coating according to claim 3, It is characterized in that During the emulsification process of the water phase and the oil phase, mechanical stirring is used for stirring, the stirring speed is 2000rpm-3500rpm, and the stirring time is 0.1-0.3h.

5. A stain-resistant self-repairing coating according to claim 3, It is characterized in that The anti-fouling auxiliary agent is a mixture of polydimethylsiloxane and nano titanium dioxide in a mass ratio of 1-2:1.5-2.

6. A stain-resistant self-repairing coating according to claim 3, It is characterized in that The plant-based solvent is a mixture of soybean oil methyl ester and limonene in a mass ratio of 4:

3.

7. A method for preparing a stain-resistant self-repairing coating according to any one of claims 1 to 6, It is characterized in that The method comprises the following preparation steps: S1. Weigh the mixed resin, self-repairing agent, anti-fouling agent and plant-based solvent by weight for later use; S2, adding deionized water to the mixed resin and stirring evenly to obtain a resin solution; S3. Add the self-repairing agent, anti-fouling agent and plant-based solvent to the resin solution in sequence, mix and stir again, filter and then use a high-speed disperser to disperse the coating to obtain the desired anti-fouling self-repairing coating.

Images