Polyacrylate / CaCO3 superhydrophobic self-cleaning coating, coating material and preparation method of coating material

Abstract

The application belongs to the technical field of functional polymer coating, and particularly discloses a polyacrylate / CaCO3 super-hydrophobic self-cleaning coating, a coating layer and a preparation method of the coating layer. Long-chain fatty carboxylic acid and acrylic acid are used as modifiers to prepare an ethanol solution with a certain concentration, and then the solution is used to modify calcium carbonate by atomization, so that the modified calcium carbonate has excellent hydrophobicity, and the contact angle can reach more than 150 degrees. Further, the modified calcium carbonate is directly mixed with long-chain acrylate resin, a free radical photoinitiator and a defoaming agent, and then is coated on the surface of a substrate and is irradiated under a UV lamp for a preset time, so that a polyacrylate / CaCO3 coating layer with super-hydrophobic self-cleaning performance is obtained. The super-hydrophobic self-cleaning coating has a wide market prospect, because the raw materials are cheap, the preparation process is simple, the coating is suitable for large-scale production, and the coating has excellent self-cleaning performance and good wear resistance.

Description

Technical Field

[0001] This invention belongs to the field of polymer coating materials technology, and relates to a polyacrylate / CaCO3 superhydrophobic self-cleaning coating, coating, and preparation method of the coating. Background Technology

[0002] Superhydrophobic materials have attracted widespread attention due to their broad application prospects in fields such as self-cleaning, corrosion prevention, anti-icing, oil-water separation, and drag reduction. In recent years, researchers have developed various methods for preparing superhydrophobic coatings, including etching, phase separation, self-assembly, hydrothermal methods, sol-gel methods, electrospinning, and template methods. However, these methods typically require specialized equipment or strict control of preparation conditions, and the preparation processes are relatively complex, sometimes necessitating the use of large amounts of organic solvents, which severely hinders the industrial application of superhydrophobic coatings.

[0003] Calcium carbonate is a very common inorganic powder material, characterized by its low cost, easy availability, non-toxicity, and harmlessness. As a filler, it offers advantages such as increasing the surface roughness of coatings and reducing the price of coating materials. However, calcium carbonate is hydrophilic with high surface free energy, making it difficult to integrate with organic polymers and prone to agglomeration. Therefore, to enhance the compatibility and dispersibility of calcium carbonate with polymer matrices, its surface needs to be modified with organic molecules. Chinese patent CN119662048A uses γ-mercaptopropyltriethoxysilane (silane coupling agent KH580) as a modifier and employs a specific modification method to modify calcium carbonate, achieving a contact angle of over 120°. However, the hydrophobicity of the modified calcium carbonate still needs improvement, making it difficult to meet the requirements for preparing high-performance superhydrophobic coatings. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide a polyacrylate / CaCO3 superhydrophobic self-cleaning coating, which has good hydrophobicity and excellent self-cleaning performance. Another objective of the present invention is to provide a method for preparing the polyacrylate / CaCO3 superhydrophobic self-cleaning coating, wherein the preparation method uses inexpensive raw materials, has a simple preparation process, and is applicable to a variety of different substrates and large-scale production.

[0005] This invention is achieved through the following technical solution: A polyacrylate / CaCO3 superhydrophobic self-cleaning coating, the coating being composed of the following components in parts by weight: 100 parts of long-chain acrylate resin, 50-500 parts of calcium carbonate modified by atomization of long-chain fatty carboxylic acid and acrylic acid, 3-10 parts of free radical photoinitiator, and 0.5-1 parts of defoamer.

[0006] A further improvement to the present invention is as follows: The long-chain acrylate resin is one or a mixture of two or more of the following: 1,12-dodecanediol dimethacrylate, 1,10-decanediol acrylate, 1,6-hexanediol acrylate, octadecyl acrylate, hexadecyl acrylate, dodecyl acrylate, dodecyl methacrylate, octadecyl methacrylate, and hexadecyl methacrylate.

[0007] Furthermore, the calcium carbonate co-modified by the long-chain fatty carboxylic acid and acrylic acid via atomization is prepared through the following steps: (1) Stearic acid is added to ethanol, heated and stirred until dissolved, then acrylic acid is added and stirred evenly to obtain an ethanol solution of long-chain fatty carboxylic acid and acrylic acid.

[0008] (2) Transfer the obtained solution to a sealed container and bubble it with air to prepare air containing the atomized solution. Then, introduce the atomized gas into a sealed stirring container containing calcium carbonate. After continuous aeration and stirring, stop introducing the atomized gas and switch to pure air. Continue stirring for a certain period of time to obtain calcium carbonate powder co-modified with long-chain fatty carboxylic acid and acrylic acid.

[0009] Furthermore, the free radical photoinitiator is one or a mixture of two or more of 2-hydroxy-2-methylphenylacetone, methyl benzoate, benzoin dimethyl ether, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, or 1-hydroxy-cyclohexyl-phenyl ketone.

[0010] Furthermore, the defoamer is one or a mixture of two or more of BYK055, BYK065, and BYK141.

[0011] A further improvement of the present invention is as follows: The present invention also provides a polyacrylate / CaCO3 superhydrophobic self-cleaning coating obtained by curing the above coating.

[0012] Furthermore, the preparation method of the polyacrylate / CaCO3 superhydrophobic self-cleaning coating includes the following steps: mixing long-chain acrylate resin, free radical photoinitiator and defoamer, stirring evenly under light, adding calcium carbonate modified by atomization with long-chain fatty carboxylic acid and acrylic acid, continuing to stir and mix under light to obtain a uniform slurry, coating the mixed slurry on the substrate surface, and irradiating it under a UV lamp for a preset time to obtain a polyacrylate / CaCO3 coating with superhydrophobic self-cleaning properties.

[0013] Furthermore, the time for stirring while shielding from light is 5-15 minutes; the time for continuing to stir while shielding from light is 10-20 minutes.

[0014] Furthermore, the power of the ultraviolet lamp is 100~500mW / cm². 2 .

[0015] Furthermore, the preset time is 2 to 30 minutes.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) Compared with the prior art, the preparation method provided by the present invention only uses long-chain acrylic resin and calcium carbonate co-modified by long-chain fatty carboxylic acid and acrylic acid to initiate polymerization. During the polymerization process, the modified calcium carbonate powder is used to generate a rough surface of the coating. At the same time, combined with the intrinsic hydrophobicity of long-chain acrylic resin and modified calcium carbonate, no additional low surface energy material is needed for modification, and no solvent is needed to obtain a polyacrylate / CaCO3 superhydrophobic coating.

[0017] (2) The present invention utilizes long-chain fatty carboxylic acid and acrylic acid to modify calcium carbonate. On the one hand, the modified grafted acrylic acid functional groups crosslink with the long-chain acrylic resin body during photopolymerization, thereby improving the wear resistance and mechanical strength of the coating. On the other hand, the modified grafted long-chain fatty carboxylic acid functional groups provide hydrophobicity to calcium carbonate and combine with the rough surface to obtain the superhydrophobic self-cleaning properties of the coating.

[0018] (3) The present invention innovatively developed a process for modifying calcium carbonate by mist polymerization. Not only does the modified calcium carbonate have excellent hydrophobic properties and a contact angle of more than 150°, but it also requires only a small amount of ethanol and does not require drying steps. It has the advantages of low solvent consumption, energy saving and environmental protection. Attached Figure Description

[0019] Figure 1 The image shows the infrared spectra of CaCO3 before and after modification in Example 1.

[0020] Figure 2 This is a scanning electron microscope image of the coating surface in Example 1. Detailed Implementation

[0021] This invention provides a polyacrylate / CaCO3 superhydrophobic self-cleaning coating, a coating layer, and a method for preparing the coating layer. In the specific embodiments, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available. The invention will be described in detail below with reference to specific embodiments.

[0022] Example 1 (1) Modification of calcium carbonate 0.005 mol of stearic acid was added to 1 L of ethanol, and the mixture was heated and stirred until the stearic acid dissolved. Then, 0.01 mol of acrylic acid was added, and the mixture was stirred for 20 min to obtain an ethanol solution of long-chain fatty carboxylic acid and acrylic acid. The resulting solution was then transferred to a sealed container, and air was bubbled through a conduit at a flow rate of 1 L / min. Then, air containing the atomized solution was bubbled through another conduit into a sealed stirred container containing 200 g of calcium carbonate. After stirring for 30 min, the atomized gas was stopped, and pure air was switched on. Stirring was continued for 60 min to obtain calcium carbonate powder co-modified with stearic acid and acrylic acid.

[0023] Infrared spectra of CaCO3 before and after modification are shown below. Figure 1 ,analyze Figure 1 It can be seen that modified CaCO3 at 2915 cm⁻¹ -1 and 2852cm -1 An absorption peak for the stretching vibration of CH appeared at 1642 cm⁻¹. -1 The presence of an absorption peak at C=C indicates that calcium carbonate has been successfully modified by stearic acid and acrylic acid. (2) Preparation of self-cleaning coating of CaCO3 / polyacrylic acid 40 parts of 1,10-decanediol acrylate, 60 parts of hexadecyl acrylate, 6 parts of 2-hydroxy-2-methylphenylacetone (free radical photoinitiator), and 0.5 parts of BYK141 defoamer were mixed in the dark and stirred for 10 minutes. Then, 260 parts of calcium carbonate (modified by atomization with stearic acid and acrylic acid) were added and stirred in the dark for 15 minutes. The mixture was then coated onto a glass surface and placed under a UV lamp at 200 mW / cm². 2 Irradiation for 10 minutes yields a polyacrylate / CaCO3 composite coating.

[0024] The scanning electron microscope image of the polyacrylate superhydrophobic coating surface is shown below. Figure 2 ,analyze Figure 2 It can be seen that the modified calcium carbonate is uniformly distributed in the coating and provides surface roughness, which helps to form the superhydrophobic properties of the coating.

[0025] Example 2 (1) Modification of calcium carbonate 0.005 mol of stearic acid was added to 1 L of ethanol, and the mixture was heated and stirred until the stearic acid dissolved. Then, 0.01 mol of acrylic acid was added, and the mixture was stirred for 20 min to obtain an ethanol solution of long-chain fatty carboxylic acid and acrylic acid. The resulting solution was then transferred to a sealed container, and air was bubbled through a conduit at a flow rate of 1 L / min. Then, air containing the atomized solution was bubbled through another conduit into a sealed stirred container containing 200 g of calcium carbonate. After stirring for 30 min, the atomized gas was stopped, and pure air was switched on. Stirring was continued for 60 min to obtain calcium carbonate powder co-modified with stearic acid and acrylic acid.

[0026] (2) Preparation of self-cleaning coating of CaCO3 / polyacrylic acid 40 parts of 1,10-decanediol acrylate, 60 parts of hexadecyl acrylate, 6 parts of 2-hydroxy-2-methylphenylacetone (free radical photoinitiator), and 0.5 parts of BYK141 defoamer were mixed in the dark and stirred for 10 minutes. Then, 100 parts of calcium carbonate (modified by atomization with stearic acid and acrylic acid) were added and stirred in the dark for 15 minutes. The mixture was then coated onto a glass surface and placed under a UV lamp at 200 mW / cm². 2 Irradiation for 10 minutes yields a polyacrylate / CaCO3 composite coating.

[0027] Example 3 (1) Modification of calcium carbonate 0.005 mol of stearic acid was added to 1 L of ethanol, and the mixture was heated and stirred until the stearic acid dissolved. Then, 0.01 mol of acrylic acid was added, and the mixture was stirred for 20 min to obtain an ethanol solution of long-chain fatty carboxylic acid and acrylic acid. The resulting solution was then transferred to a sealed container, and air was bubbled through a conduit at a flow rate of 1 L / min. Then, air containing the atomized solution was bubbled through another conduit into a sealed stirred container containing 200 g of calcium carbonate. After stirring for 30 min, the atomized gas was stopped, and pure air was switched on. Stirring was continued for 60 min to obtain calcium carbonate powder co-modified with stearic acid and acrylic acid.

[0028] (2) Preparation of self-cleaning coating of CaCO3 / polyacrylic acid 40 parts of 1,10-decanediol acrylate, 60 parts of hexadecyl acrylate, 6 parts of 2-hydroxy-2-methylphenylacetone (free radical photoinitiator), and 0.5 parts of BYK141 defoamer were mixed in the dark and stirred for 10 minutes. Then, 400 parts of calcium carbonate (modified by atomization with stearic acid and acrylic acid) were added and stirred in the dark for 15 minutes. The mixture was then coated onto a glass surface and placed under a UV lamp at 200 mW / cm². 2 Irradiation for 10 minutes yields a polyacrylate / CaCO3 composite coating.

[0029] Example 4 (1) Modification of calcium carbonate 0.001 mol of stearic acid was added to 1 L of ethanol, and the mixture was heated and stirred until the stearic acid dissolved. Then, 0.01 mol of acrylic acid was added, and the mixture was stirred for 20 min to obtain an ethanol solution of long-chain fatty carboxylic acid and acrylic acid. The resulting solution was then transferred to a sealed container, and air was bubbled through a conduit at a flow rate of 1 L / min. Then, air containing the atomized solution was bubbled through another conduit into a sealed stirred container containing 200 g of calcium carbonate. After stirring for 30 min, the atomized gas was stopped, and pure air was switched to the solution. Stirring was continued for another 60 min to obtain calcium carbonate powder co-modified with stearic acid and acrylic acid.

[0030] (2) Preparation of self-cleaning coating of CaCO3 / polyacrylic acid 40 parts of 1,10-decanediol acrylate, 60 parts of hexadecyl acrylate, 6 parts of 2-hydroxy-2-methylphenylacetone (free radical photoinitiator), and 0.5 parts of BYK141 defoamer were mixed in the dark and stirred for 10 minutes. Then, 260 parts of calcium carbonate (modified by atomization with stearic acid and acrylic acid) were added and stirred in the dark for 15 minutes. The mixture was then coated onto a glass surface and placed under a UV lamp at 200 mW / cm². 2 Irradiation for 10 minutes yields a polyacrylate / CaCO3 composite coating.

[0031] Example 5 (1) Modification of calcium carbonate 0.005 mol of stearic acid was added to 1 L of ethanol, and the mixture was heated and stirred until the stearic acid dissolved. Then, 0.001 mol of acrylic acid was added, and the mixture was stirred for 20 min to obtain an ethanol solution of long-chain fatty carboxylic acid and acrylic acid. The resulting solution was then transferred to a sealed container, and air was bubbled through a conduit at a flow rate of 1 L / min. Then, air containing the atomized solution was bubbled through another conduit into a sealed stirred container containing 200 g of calcium carbonate. After stirring for 30 min, the atomized gas was stopped, and pure air was switched to the solution. Stirring was continued for another 60 min to obtain calcium carbonate powder co-modified with stearic acid and acrylic acid.

[0032] (2) Preparation of self-cleaning coating of CaCO3 / polyacrylic acid 40 parts of 1,10-decanediol acrylate, 60 parts of hexadecyl acrylate, 6 parts of 2-hydroxy-2-methylphenylacetone (free radical photoinitiator), and 0.5 parts of BYK141 defoamer were mixed in the dark and stirred for 10 minutes. Then, 260 parts of calcium carbonate (modified by atomization with stearic acid and acrylic acid) were added and stirred in the dark for 15 minutes. The mixture was then coated onto a glass surface and placed under a UV lamp at 200 mW / cm². 2 Irradiation for 10 minutes yields a polyacrylate / CaCO3 composite coating.

[0033] Example 6 (1) Modification of calcium carbonate 0.005 mol of stearic acid was added to 1 L of ethanol, and the mixture was heated and stirred until the stearic acid dissolved. Then, 0.01 mol of acrylic acid was added, and the mixture was stirred for 20 min to obtain an ethanol solution of long-chain fatty carboxylic acid and acrylic acid. The resulting solution was then transferred to a sealed container, and air was bubbled through a conduit at a flow rate of 1 L / min. Then, air containing the atomized solution was bubbled through another conduit into a sealed stirred container containing 200 g of calcium carbonate. After stirring for 30 min, the atomized gas was stopped, and pure air was switched on. Stirring was continued for 60 min to obtain calcium carbonate powder co-modified with stearic acid and acrylic acid.

[0034] (2) Preparation of self-cleaning coating of CaCO3 / polyacrylic acid 40 parts of 1,10-decanediol acrylate, 60 parts of dodecyl acrylate, 6 parts of 2-hydroxy-2-methylphenylacetone (a free radical photoinitiator), and 0.5 parts of BYK141 defoamer were mixed in the dark and stirred for 10 minutes. Then, 260 parts of calcium carbonate (modified by atomization with stearic acid and acrylic acid) were added and stirred in the dark for 15 minutes. The mixture was then coated onto a glass surface and placed under a UV lamp at 200 mW / cm². 2 Irradiation for 10 minutes yields a polyacrylate / CaCO3 composite coating.

[0035] Comparative example: (1) Modification of calcium carbonate 0.005 mol of stearic acid was added to 1 L of ethanol, and the mixture was heated and stirred until the stearic acid dissolved. Then, 0.01 mol of acrylic acid was added, and the mixture was stirred for 20 min to obtain an ethanol solution of long-chain fatty carboxylic acid and acrylic acid. 200 g of calcium carbonate was then added to the resulting solution and stirred for 30 min. The solution was centrifuged, dried at 40 °C for 12 h, and ground to obtain calcium carbonate powder co-modified with stearic acid and acrylic acid.

[0036] (2) Preparation of self-cleaning coating of CaCO3 / polyacrylic acid 40 parts of 1,10-decanediol acrylate, 60 parts of hexadecyl acrylate, 6 parts of 2-hydroxy-2-methylphenylacetone (free radical photoinitiator), and 0.5 parts of BYK141 defoamer were mixed in the dark and stirred for 10 minutes. Then, 260 parts of calcium carbonate (modified by atomization with stearic acid and acrylic acid) were added and stirred in the dark for 15 minutes. The mixture was then coated onto a glass surface and placed under a UV lamp at 200 mW / cm². 2 Irradiation for 10 minutes yields a polyacrylate / CaCO3 composite coating.

[0037] Test case The coatings prepared in Examples 1-6 and the comparative examples were subjected to performance tests using the following methods. Specifically: Water contact angle test: A contact angle measuring instrument (model JC 2000C 2) from Shanghai Zhongchen Digital Technology Equipment Co., Ltd. was used. A standard droplet volume of 5 μL was used to determine the water contact angle value of the film sample. To reduce error, five different sites were randomly selected for testing for each sample, and the final result was the average of the measured values ​​at each point.

[0038] Pencil hardness test: conducted in accordance with national standard GB / T 6739-2022.

[0039] Adhesion test: conducted in accordance with national standard GB / T 9286-2021.

[0040] Hydrophobic surface abrasion resistance test: The prepared coating is placed on 1000-grit sandpaper, and a 200 g weight (1.02 kPa pressure) is placed on the coating. Then, it is dragged 10 cm in one direction, which is recorded as one abrasion test. One round trip is one abrasion cycle, and the test is repeated 100 times.

[0041] The test results are shown in Table 1.

[0042] Table 1. Test results of polyacrylate / CaCO3 composite coating Example 1 152 H 0 158 Example 2 134 2H 0 144 Example 3 154 2B 1 161 Example 4 136 H 0 129 Example 5 153 B 0 158 Example 6 148 H 0 153 Comparative Example 141 H 1 150 Analysis of the data in Table 1 shows that as the amount of modified CaCO3 increases, the hydrophobicity of the prepared composite coating is enhanced, but the pencil hardness of the coating decreases and the adhesion also decreases slightly (Example 3). Compared with Example 1 and Example 4, when the amount of stearic acid is significantly reduced, the hydrophobicity of the resulting composite coating decreases significantly. Compared with Example 1 and Example 5, when the amount of acrylic acid is significantly reduced, the pencil hardness of the resulting composite coating decreases significantly, indicating that the crosslinking effect of acrylic acid is very important for the mechanical strength of the coating. Compared with the comparative example, Example 1 shows that the atomization method for modifying calcium carbonate has more advantages than the traditional modification method in preparing superhydrophobic polyacrylate / CaCO3 composite coatings.

[0043] The above description of the embodiments is only for illustrating the technical concept and features of the present invention. Its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. Those skilled in the art can obviously easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative effort. Therefore, the above embodiments should not be used to limit the scope of protection of the present invention. All improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A polyacrylate / CaCO3 superhydrophobic self-cleaning coating, characterized in that, It is composed of the following components by weight: 100 parts of long-chain acrylate resin, 50-500 parts of calcium carbonate modified by atomization of long-chain fatty carboxylic acid and acrylic acid, 3-10 parts of free radical photoinitiator, and 0.5-1 parts of defoamer.

2. The polyacrylate / CaCO3 superhydrophobic self-cleaning coating according to claim 1, characterized in that: The long-chain acrylate resin is one or a mixture of two or more of the following: 1,12-dodecanediol dimethacrylate, 1,10-decanediol acrylate, 1,6-hexanediol acrylate, octadecyl acrylate, hexadecyl acrylate, dodecyl acrylate, dodecyl methacrylate, octadecyl methacrylate, and hexadecyl methacrylate.

3. The polyacrylate / CaCO3 superhydrophobic self-cleaning coating according to claim 1, characterized in that: The calcium carbonate, co-modified by the long-chain fatty carboxylic acid and acrylic acid via atomization, is prepared through the following steps: (1) Stearic acid is added to ethanol, heated and stirred until dissolved, then acrylic acid is added and stirred evenly to obtain an ethanol solution of long-chain fatty carboxylic acid and acrylic acid; (2) Transfer the obtained solution to a sealed container and bubble it with air to prepare air containing the atomized solution. Then, introduce the atomized gas into a sealed stirring container containing calcium carbonate. After continuous aeration and stirring, stop introducing the atomized gas and switch to pure air. Continue stirring for a certain period of time to obtain calcium carbonate powder co-modified with long-chain fatty carboxylic acid and acrylic acid.

4. The polyacrylate / CaCO3 superhydrophobic self-cleaning coating according to claim 1, characterized in that: The free radical photoinitiator is one or a mixture of two or more of 2-hydroxy-2-methylphenylpropanone, methyl benzoylformate, benzoin dimethyl ether, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, or 1-hydroxy-cyclohexyl-phenyl ketone.

5. The polyacrylate / CaCO3 superhydrophobic self-cleaning coating according to claim 1, characterized in that: The defoamer is one or a mixture of two or more of BYK055, BYK065, and BYK141.

6. A polyacrylate / CaCO3 superhydrophobic self-cleaning coating, characterized in that it is obtained by curing the coating described in any one of claims 1 to 5.

7. The method for preparing the polyacrylate / CaCO3 superhydrophobic self-cleaning coating as described in claim 6, characterized in that, The process includes the following steps: mixing long-chain acrylate resin, free radical photoinitiator and defoamer, stirring evenly under light, adding calcium carbonate modified by atomization with long-chain fatty carboxylic acid and acrylic acid, continuing to stir and mix under light to obtain a uniform slurry, coating the mixed slurry onto the substrate surface, and irradiating it under a UV lamp for a preset time to obtain a polyacrylate / CaCO3 coating with superhydrophobic self-cleaning properties.

8. The method for preparing the polyacrylate / CaCO3 superhydrophobic self-cleaning coating according to claim 7, characterized in that: The time for stirring under light is 5-15 minutes; the time for continuing stirring under light is 10-20 minutes.

9. The method for preparing the polyacrylate / CaCO3 superhydrophobic self-cleaning coating according to claim 7, characterized in that: The power of the ultraviolet lamp is 100~500mW / cm². 2 .

10. The method for preparing the polyacrylate / CaCO3 superhydrophobic self-cleaning coating according to claim 7, characterized in that: The preset time is 2 to 30 minutes.

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