A highly water-resistant water-soluble hydroxy acrylic resin and a method for preparing the coating thereof

Abstract

The present invention relates to the technical field of resin coatings, and provides a highly water-resistant water-based hydroxy acrylic resin and a coating preparation method thereof. The resin is made of the following raw materials: an alcohol ether solvent, a mixed monomer, an initiator, 2-perfluorooctylethanol, water-resistant group surface-modified silica particles, deionized water, and a dimethylethanolamine neutralizer. Coating preparation process: S1. Preparation of water-based hydroxy acrylic resin; S2. Detection of water-based hydroxy acrylic resin; S3: Preparation of water-based hydroxy acrylic resin paint; S4: Preparation of water-based hydroxy acrylic resin coating, and obtaining water-based hydroxy acrylic resin coating. The water-resistant hydroxy acrylic resin significantly improves the water resistance by adding perfluorinated compounds, and the silica particles are modified to form a hydrophobic protective film, which further enhances the water resistance. This technology has important application value in the fields of coatings, waterproof materials, etc.

Description

Technical Field

[0001] The invention relates to the technical field of resin coatings, and in particular to a highly water-resistant water-soluble hydroxy acrylic resin and a coating preparation method thereof. Background Art

[0002] All coatings that use water as a solvent or dispersion medium can be called water-based coatings. Based on the type of binder in the coating, water-based coatings are divided into two categories: natural water-based coatings made of natural substances or minerals (such as potassium silicate) and petrochemical water-based coatings made of synthetic resins (such as acrylic resins). Only water-based coatings made of synthetic resins are described here.

[0003] Water-based paints include water-soluble paints, water-dilutable paints, and water-dispersible paints (latex paints). Water-soluble paints use water-soluble resins as film-forming materials, represented by polyvinyl alcohol and its various modified products. In addition, there are water-soluble alkyd resins, water-soluble epoxy resins, and inorganic polymer water-based resins.

[0004] With the strengthening of people's environmental awareness and environmental regulations, the research and development of environmentally friendly water-based acrylics has received increasing attention. Among them, water-based hydroxyl acrylic paints have excellent weather resistance and decorative properties and are widely used. However, due to the certain content of hydroxyl hydrophilic groups in its film-forming substance, the water-based acrylic resin, the water resistance of the paint is limited. Therefore, it is urgent to develop a highly water-resistant water-based hydroxyl acrylic paint. Summary of the invention

[0005] (1) Technical issues solved

[0006] The purpose of the present invention is to provide a highly water-resistant water-based hydroxy acrylic resin and a method for preparing a coating thereof, so as to solve the problem that the current water-based hydroxy acrylic resin has insufficient water resistance.

[0007] (2) Technical solution

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A highly water-resistant water-soluble hydroxy acrylic resin is prepared from the following raw materials in parts by weight: 2-4 parts of alcohol ether solvent, 34-62 parts of mixed monomers, 1.5-5 parts of initiator, 3-6 parts of 2-perfluorooctylethanol, 5-12 parts of silicon dioxide particles with water-resistant group surface modification, 35-55 parts of deionized water and 1-2 parts of dimethylethanolamine neutralizer.

[0010] The alcohol ether solvent is glycol methyl ether acetate or propylene glycol methyl ether.

[0011] The mixed monomer is a mixture of 15-25 parts of methyl methacrylate, 5-10 parts of butyl acrylate, 2-5 parts of 2-ethylhexyl acrylate, 7-10 parts of hydroxyethyl methacrylate, 3-7 parts of butyl methacrylate and 2-5 parts of acrylic acid.

[0012] The initiator is a mixture of 0.5-2 parts of n-dodecyl mercaptan and 1-3 parts of benzoyl peroxide.

[0013] The preparation method of the water-based hydroxylated acrylic resin coating comprises the following steps:

[0014] S1. Preparation of water-based hydroxy acrylic resin: 2 to 4 parts of alcohol ether solvent, 35 to 62 parts of mixed monomer, 1.5 to 5 parts of initiator, 3 to 6 parts of 2-perfluorooctylethanol, 5 to 12 parts of water-resistant group surface modified silica particles, 35 to 55 parts of deionized water and 1 to 2 parts of dimethylethanolamine neutralizer are prepared into water-based hydroxy acrylic resin;

[0015] S2. Testing of water-based hydroxyl acrylic resin: Testing the water-based hydroxyl acrylic resin synthesized in S1, including solid content, viscosity, pH value and hydroxyl value content. The next step is performed after the test meets the standards;

[0016] S3: Preparation of water-based hydroxyl acrylic resin paint: The water-based hydroxyl acrylic resin that meets the test standards in S2 is used to prepare water-based hydroxyl acrylic resin paint;

[0017] S4: Preparation of water-based hydroxy acrylic resin coating: The water-based hydroxy acrylic resin paint prepared in S3 is mixed with a water-based isocyanate curing agent to obtain a water-based hydroxy acrylic resin coating.

[0018] Preferably, the S1 comprises the following steps:

[0019] S11: Add alcohol ether solvent, 2-perfluorooctylethanol and silica particles with water-resistant group surface modification into the reaction kettle, raise the temperature from room temperature to 130°C, and stir for 2-4 hours;

[0020] S12: adding the mixed monomer and the initiator to the reactor simultaneously by dropwise addition, and the dropwise addition lasts for 3 to 4 hours;

[0021] S13: After the dropwise addition is completed, the temperature is kept at 0.5 to 1 h to terminate the reaction;

[0022] S14: After the reaction is completed, the temperature is lowered to 90°C and a dimethylethanolamine neutralizer is added. After sufficient neutralization, 35 to 55 parts of deionized water are added and stirred to emulsify the product. The emulsification time is 1 to 2 hours.

[0023] S15: Continue stirring for 1 to 1.5 hours, then cool to room temperature to obtain a water-based hydroxy acrylic resin.

[0024] Preferably, the preparation method of the water-resistant group surface-modified silica particles is as follows: by weight, 16 to 30 parts of isophorone diisocyanate and 8 to 15 parts of octadecyl alcohol are added to a beaker, heated to 65 to 80° C., and kept warm for 2 to 4 hours for grafting reaction, and then 30 to 65 parts of silane surface-modified silica particles and 2 to 4 parts of dibutyltin dilaurate are added, stirred for reaction for 24 to 36 hours, cooled and filtered, washed three times with butyl acetate, and then dried to obtain water-resistant group surface-modified silica particles.

[0025] Preferably, the mass ratio of isophorone diisocyanate to octadecyl alcohol is 2:1.

[0026] Preferably, the preparation method of the silane surface modified silica particles is as follows: in parts by weight, 10 to 20 parts of nano-SiO2 particles are added to 100 parts of a mixed solution of 50% ethanol and deionized water by mass, ultrasonically dispersed for 2 to 4 hours, and then 5 to 12 parts of silane coupling agent KH-570 and 3 to 8 parts of 50% oxalic acid solution by mass are added, and ultrasonic dispersion is continued for 1 hour, and then washed three times with a mixed solution of 50% ethanol and deionized water by mass to remove excess KH-570 and its by-products adsorbed on the surface of the nano-SiO2 particles, and then the filtrate is placed in a vacuum drying oven for drying to obtain silane surface modified silica particles.

[0027] Preferably, the detection indicators of the water-based hydroxylated acrylic resin in S2 are: solid content mass fraction of 44-46%, viscosity of 2000-5000 Pa.s, pH value of 7-9, and hydroxyl content mass fraction of 2.3-3.2%.

[0028] Preferably, the preparation method of the water-based hydroxy acrylic resin paint in S3 is as follows: in parts by weight, 60-80 parts of the water-based hydroxy acrylic resin that has passed the inspection in step S2, 10-15 parts of deionized water, 10-25 parts of pigment, 0.2-5 parts of dispersant, 0.2-5 parts of leveling agent, and 0.2-5 parts of defoaming agent are mixed evenly, and then ground evenly with a sand mill to a fineness of less than 10 um.

[0029] Preferably, the dispersant is organic bentonite 801-A;

[0030] The leveling agent is fluorine-modified acrylate leveling agent LD-1084;

[0031] The defoaming agent is AGITAN760;

[0032] The pigment is any one of phthalocyanine blue, carbon black, medium chrome yellow, red iron oxide and titanium dioxide.

[0033] Preferably, the water-based isocyanate curing agent in S4 is selected from Covestro XP2655 curing agent.

[0034] Preferably, the preparation method of the water-based hydroxy acrylic resin coating in S4 is: diluting Covestro XP2655 curing agent with propylene glycol methyl ether acetate to 60% solid content to obtain a curing agent solution, and then adding water-based hydroxy acrylic resin paint and water to the curing agent solution to obtain a water-based hydroxy acrylic resin coating, wherein the mass ratio of the water-based hydroxy acrylic resin paint, the curing agent solution and the deionized water is 100:20~25:10~20.

[0035] The present invention aims to prepare a water-resistant hydroxy acrylic resin, wherein perfluorooctylethanol is added to improve its water resistance. Perfluorooctylethanol is a hydrophobic compound, which reacts with the hydroxyl group in the hydroxy acrylic resin to form perfluorooctyl acetate propylene, and this reaction not only increases the hydrophobicity of the acrylic resin, but also improves its water resistance. The perfluorocarbon chain in perfluorooctyl acetate propylene has a very low surface energy, which can effectively inhibit the contact between water molecules and the surface of the material, thereby preventing water penetration. In addition, the perfluorocarbon chain in perfluorooctyl acetate propylene can also prevent the penetration of other liquids and solvents, thereby enhancing the chemical corrosion resistance of the acrylic resin. Therefore, adding perfluorooctylethanol to the preparation process of the water-resistant hydroxy acrylic resin can significantly improve the water resistance of the acrylic resin and enhance its chemical corrosion resistance.

[0036] The purpose of the present invention to modify silicon dioxide by using isophorone diisocyanate and octadecanol is to improve the water resistance of silicon dioxide. After the reaction of isophorone diisocyanate and octadecanol, the long-chain fatty alcohol group in octadecanol is introduced into the surface of silicon dioxide particles, making it hydrophobic, so that a hydrophobic layer is formed in the coating, reducing the surface area in contact with water, thereby reducing the rate of the hydrolysis reaction. This hydrophobic modification helps to improve the water resistance of the coating, is suitable for coatings, waterproof materials, anti-corrosion coatings and other fields, and improves the performance and service life of the material.

[0037] Beneficial technical effects

[0038] First, perfluorooctylethanol was added to the water-resistant hydroxy acrylic resin, and perfluorooctyl acetate was synthesized, which greatly enhanced the water resistance of the resin. The perfluorocarbon chain in perfluorooctyl acetate has excellent hydrophobicity, which can effectively prevent the penetration of water molecules, so that the resin can still maintain stable performance in the face of humid environments. Secondly, the silica particles were modified with isophorone diisocyanate and octadecyl alcohol to further improve their water resistance. During the modification process, isophorone diisocyanate reacted with octadecyl alcohol, and the long-chain fatty alcohol group of octadecyl alcohol was introduced into the surface of the silica particles, forming a hydrophobic protective film. This protective film effectively reduces the surface area of ​​the silica particles in contact with water, thereby reducing the rate of the hydrolysis reaction and significantly improving its water resistance. This hydrophobic modification technology has significant application value in the fields of coatings, waterproof materials, anti-corrosion coatings, etc. In these fields, materials often need to face harsh environments such as humidity and water immersion, and the improvement of water resistance can significantly improve the service life and stability of the materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is the FTIR spectrum of the water-based hydroxylated acrylic resin coating prepared in Example 1 of the present invention.

[0040] Figure 2 This is the SEM morphology of the silica particles with surface modified with water-resistant groups prepared in Example 1 of the present invention.

[0041] Figure 3 This is a surface morphology of the coating prepared in Example 1 of the present invention after the water resistance test. DETAILED DESCRIPTION

[0042] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0043] In the absence of specific conditions, the operations in the examples are carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not indicated, are all common products on the market. Parts not mentioned in the technical content of the present invention will be processed with reference to the prior art. Unless otherwise specified, the following examples and comparative examples will be tested in parallel and use the same processing steps and parameters. Table 1 shows the reagents required for the examples and comparative examples and the corresponding purchasing companies.

[0044] Table 1 Reagents required for the examples and comparative examples and the corresponding purchasing companies

[0045] Reagents company 2-Perfluorooctylethanol Zhejiang Hangyu Pharmaceutical Technology Co., Ltd. Glycol methyl ether acetate Shanghai Ruiyan Petrochemical Co., Ltd. Propylene glycol methyl ether Shanghai MacLean Biochemical Technology Co., Ltd. Methyl Methacrylate China National Pharmaceutical Group Corporation Butyl acrylate Shandong West Asia Chemical Co., Ltd. 2-Ethylhexyl acrylate Himaclin Biochemical Technology Co., Ltd. Hydroxyethyl Methacrylate Guangzhou Haoyu International Trade Co., Ltd. Butyl Methacrylate Shandong West Asia Chemical Co., Ltd. acrylic acid Jinan Jinhao Chemical Co., Ltd. Polycarbonate diol Shanghai Yuanye Biotechnology Co., Ltd. Trifluoroacetaldehyde hydrate Shandong West Asia Chemical Co., Ltd. Toluene diisocyanate Qianyan Chemical Technology (Wuhan) Co., Ltd. Dimethylbiphenyl diisocyanate Shanghai MacLean Biochemical Technology Co., Ltd. n-dodecanethiol Guangdong Wengjiang Chemical Reagent Co., Ltd. Benzoyl peroxide Shandong Mantanghong New Materials Co., Ltd. dimethylethanolamine Shandong West Asia Chemical Co., Ltd. Isophorone diisocyanate Shanghai MacLean Biochemical Technology Co., Ltd. Octadecanol Guangdong Wengjiang Chemical Reagent Co., Ltd. Silica particles Zhejiang Hangyu Pharmaceutical Technology Co., Ltd. Dibutyltin dilaurate Guangdong Wengjiang Chemical Reagent Co., Ltd. Butyl acetate Guangzhou Yuanda New Materials Co., Ltd. Ethanol Shandong Mantanghong New Materials Co., Ltd. Silane coupling agent KH-570 Shandong West Asia Chemical Co., Ltd. oxalic acid Shandong Mantanghong New Materials Co., Ltd. Organic bentonite 801-A Shanghai MacLean Biochemical Technology Co., Ltd. Propylene glycol methyl ether acetate Shanghai MacLean Biochemical Technology Co., Ltd. pigment Shandong Mantanghong New Materials Co., Ltd. Fluorine modified acrylate leveling agent LD-1084 Shandong Jiaying Chemical Technology Co., Ltd. AGITAN760 Germany Mingling Company XP2655 Curing Agent Covestro AG

[0046] Example 1

[0047] A highly water-resistant water-soluble hydroxy acrylic resin is prepared from the following raw materials in parts by weight: 2 parts of glycol methyl ether acetate, 34 parts of mixed monomers, 1.5 parts of initiator, 3 parts of 2-perfluorooctylethanol, 5 parts of water-resistant group surface-modified silica particles, 35 parts of deionized water and 1 part of dimethylethanolamine neutralizer.

[0048] The mixed monomer is a mixture of 15 parts of methyl methacrylate, 5 parts of butyl acrylate, 2 parts of 2-ethylhexyl acrylate, 7 parts of hydroxyethyl methacrylate, 3 parts of butyl methacrylate and 2 parts of acrylic acid.

[0049] The initiator is a mixture of 0.5 parts of n-dodecyl mercaptan and 1 part of benzoyl peroxide.

[0050] The preparation method of the above-mentioned water-based hydroxylated acrylic resin coating comprises the following steps:

[0051] S1. Preparation of water-based hydroxy acrylic resin: First, add glycol methyl ether acetate, 2-perfluorooctylethanol and water-resistant group surface modified silica particles into the reactor; then, raise the temperature from room temperature to 130°C, and stir the mixture at this temperature for 2 hours; then, add the mixed monomer and initiator to the reactor in a dropwise manner at the same time, and ensure that the dropwise addition process lasts for 3 hours; after the dropwise addition is completed, maintain the temperature at 130°C and continue stirring for 0.5 hours to terminate the reaction. After the reaction is completed, lower the temperature to 90°C, then add dimethylethanolamine neutralizer and fully neutralize it; then, add 35 parts of deionized water, and start stirring to gradually emulsify the product. This emulsification process needs to last for 1 hour. After emulsification is completed, continue stirring for 1 hour to ensure that the product is evenly mixed. Finally, after cooling to room temperature, the water-based hydroxy acrylic resin is obtained;

[0052] S2. Detection of water-based hydroxyl acrylic resin: The water-based hydroxyl acrylic resin synthesized in S1 was tested, and the test indicators were: solid content mass fraction of 44%, viscosity of 2000 Pa.s, pH value of 7, hydroxyl content mass fraction of 2.3%. After the test met the standards, the next step was performed;

[0053] S3: Preparation of water-based hydroxyl acrylic resin paint: The water-based hydroxyl acrylic resin that meets the standards in S2 is used to prepare water-based hydroxyl acrylic resin paint; the preparation method is as follows: by weight, 60 parts of the water-based hydroxyl acrylic resin that meets the standards in step S2, 10 parts of deionized water, 10 parts of phthalocyanine blue, 0.2 parts of organic bentonite 801-A, 0.2 parts of fluorine-modified acrylic leveling agent LD-1084, and 0.2 parts of AGITAN760 are mixed evenly, and then ground evenly with a sand mill to a fineness of less than 10 um;

[0054] S4: Preparation of water-based hydroxy acrylic resin coating: The water-based hydroxy acrylic resin paint prepared in S3 is mixed with Covestro XP2655 curing agent to obtain a water-based hydroxy acrylic resin coating. The preparation method is: Covestro XP2655 curing agent is diluted with propylene glycol methyl ether acetate to 60% solid content to obtain a curing agent solution, and then water-based hydroxy acrylic resin paint and water are added to the curing agent solution to obtain a water-based hydroxy acrylic resin coating, wherein the mass ratio of the water-based hydroxy acrylic resin paint, the curing agent solution and the deionized water is 100:20:10.

[0055] The preparation method of the above-mentioned water-resistant group surface modified silica particles is as follows: in parts by weight, 16 parts of isophorone diisocyanate and 8 parts of octadecyl alcohol are added to a beaker, heated to 65°C, and kept warm for 2 hours for grafting reaction, and then 30 parts of silane surface modified silica particles and 2 parts of dibutyltin dilaurate are added, stirred for reaction for 24 hours, cooled and filtered, washed three times with butyl acetate, and then dried to obtain water-resistant group surface modified silica particles.

[0056] The preparation method of the silane surface modified silica particles is as follows: in parts by weight, 10 to 20 parts of nano-SiO2 particles are added to 100 parts of a mixed solution of 50% ethanol and deionized water by mass, and ultrasonic dispersion is performed for 2 to 4 hours. Then, 5 to 12 parts of silane coupling agent KH-570 and 3 to 8 parts of 50% oxalic acid solution by mass are added, and ultrasonic dispersion is continued for 1 hour. Then, the particles are washed three times with a mixed solution of 50% ethanol and deionized water by mass to remove excess KH-570 and its by-products adsorbed on the surface of the nano-SiO2 particles. Then, the filtrate is placed in a vacuum drying oven and dried to obtain silane surface modified silica particles.

[0057] Example 2

[0058] A highly water-resistant water-soluble hydroxy acrylic resin is prepared from the following raw materials in parts by weight: 3 parts of propylene glycol methyl ether, 42 parts of mixed monomers, 2 parts of initiator, 4 parts of 2-perfluorooctylethanol, 7 parts of silicon dioxide particles with water-resistant group surface modification, 38 parts of deionized water and 1.2 parts of dimethylethanolamine neutralizer.

[0059] The mixed monomer is a mixture of 18 parts of methyl methacrylate, 6 parts of butyl acrylate, 3 parts of 2-ethylhexyl acrylate, 8 parts of hydroxyethyl methacrylate, 4 parts of butyl methacrylate and 3 parts of acrylic acid.

[0060] The initiator is a mixture of 1 part of n-dodecyl mercaptan and 1 part of benzoyl peroxide.

[0061] The preparation method of the above-mentioned water-based hydroxylated acrylic resin coating comprises the following steps:

[0062] S1. Preparation of water-based hydroxy acrylic resin: First, add alcohol ether solvents, 2-perfluorooctylethanol and water-resistant group surface modified silica particles to the reactor; then, raise the temperature from room temperature to 130°C, and stir the mixture at this temperature for 3 hours; then, add the mixed monomer and initiator to the reactor in a dropwise manner at the same time, ensuring that the dropwise addition process lasts for 3 hours; after the dropwise addition is completed, keep the temperature at 130°C and continue stirring for 1 hour to terminate the reaction. After the reaction is completed, the temperature is lowered to 90°C, and then dimethylethanolamine neutralizer is added and fully neutralized; then, 40 parts of deionized water are added and stirring is started to gradually emulsify the product. This emulsification process needs to last for 1.5 hours. After emulsification is completed, continue stirring for 1.2 hours to ensure that the product is evenly mixed. Finally, the water-based hydroxy acrylic resin is obtained after cooling to room temperature.

[0063] S2. Detection of water-based hydroxyl acrylic resin: The water-based hydroxyl acrylic resin synthesized in S1 was tested, and the test indicators were: solid content mass fraction of 45%, viscosity of 3000 Pa.s, pH value of 8, hydroxyl content mass fraction of 2.6%. After the test met the standards, the next step was performed;

[0064] S3: Preparation of water-based hydroxy acrylic resin paint: The water-based hydroxy acrylic resin that meets the standards in S2 is used to prepare water-based hydroxy acrylic resin paint; the preparation method is as follows: by weight, 65 parts of the water-based hydroxy acrylic resin that meets the standards in step S2, 12 parts of deionized water, 12 parts of carbon black, 0.8 parts of organic bentonite 801-A, 0.5 parts of fluorine-modified acrylic leveling agent LD-1084, and 0.5 parts of AGITAN760 are mixed evenly, and then ground evenly with a sand mill to a fineness of less than 10 um;

[0065] S4: Preparation of water-based hydroxy acrylic resin coating: The water-based hydroxy acrylic resin paint prepared in S3 is mixed with Covestro XP2655 curing agent to obtain a water-based hydroxy acrylic resin coating. The preparation method is: Covestro XP2655 curing agent is diluted with propylene glycol methyl ether acetate to 60% solid content to obtain a curing agent solution, and then water-based hydroxy acrylic resin paint and water are added to the curing agent solution to obtain a water-based hydroxy acrylic resin coating, wherein the mass ratio of the water-based hydroxy acrylic resin paint, the curing agent solution and the deionized water is 100:22:12.

[0066] The preparation method of the above-mentioned water-resistant group surface modified silica particles is as follows: in parts by weight, 18 parts of isophorone diisocyanate and 9 parts of octadecyl alcohol are added to a beaker, heated to 70°C, and kept warm for 3 hours for grafting reaction, and then 35 parts of silane surface modified silica particles and 3 parts of dibutyltin dilaurate are added, stirred for reaction for 28 hours, cooled and filtered, washed three times with butyl acetate, and then dried to obtain water-resistant group surface modified silica particles.

[0067] The preparation method of the silane surface modified silica particles is as follows: in parts by weight, 12 parts of nano-SiO2 particles are added to 100 parts of a mixed solution of 50% ethanol and deionized water by mass, and ultrasonic dispersion is performed for 3 hours. Then, 7 parts of silane coupling agent KH-570 and 4 parts of 50% oxalic acid solution by mass are added, and ultrasonic dispersion is continued for 1 hour. Then, the particles are washed three times with a mixed solution of 50% ethanol and deionized water by mass to remove excess KH-570 and its by-products adsorbed on the surface of the nano-SiO2 particles. Then, the filtrate is placed in a vacuum drying oven and dried to obtain silane surface modified silica particles.

[0068] Example 3

[0069] A highly water-resistant water-soluble hydroxy acrylic resin is prepared from the following raw materials in parts by weight: 3 parts of glycol methyl ether acetate, 52 parts of mixed monomers, 4 parts of initiator, 5 parts of 2-perfluorooctylethanol, 10 parts of water-resistant group surface-modified silica particles, 50 parts of deionized water and 1.5 parts of dimethylethanolamine neutralizer.

[0070] The mixed monomer is a mixture of 22 parts of methyl methacrylate, 8 parts of butyl acrylate, 4 parts of 2-ethylhexyl acrylate, 8 parts of hydroxyethyl methacrylate, 6 parts of butyl methacrylate and 4 parts of acrylic acid.

[0071] The initiator is a mixture of 1.5 parts of n-dodecyl mercaptan and 2.5 parts of benzoyl peroxide.

[0072] The preparation method of the above-mentioned water-based hydroxylated acrylic resin coating comprises the following steps:

[0073] S1. Preparation of water-based hydroxy acrylic resin: First, add alcohol ether solvent, 2-perfluorooctylethanol and water-resistant group surface modified silica particles to the reactor; then, raise the temperature from room temperature to 130°C, and stir the mixture at this temperature for 3 hours; then, add the mixed monomer and initiator to the reactor in a dropwise manner at the same time, ensuring that the dropwise addition process lasts for 4 hours; after the dropwise addition is completed, keep the temperature at 130°C and continue stirring for 1 hour to terminate the reaction. After the reaction is completed, the temperature is lowered to 90°C, and then dimethylethanolamine neutralizer is added and fully neutralized; then, 50 parts of deionized water are added and stirring is started to gradually emulsify the product, and this emulsification process needs to last for 2 hours. After emulsification is completed, continue stirring for 1.5 hours to ensure that the product is evenly mixed. Finally, the water-based hydroxy acrylic resin is obtained after cooling to room temperature.

[0074] S2. Detection of water-based hydroxyl acrylic resin: The water-based hydroxyl acrylic resin synthesized in S1 was tested, and the test indicators were: solid content mass fraction of 45%, viscosity of 4000 Pa.s, pH value of 8, hydroxyl content mass fraction of 3.0%, and the next step was performed after the test met the standards;

[0075] S3: Preparation of water-based hydroxy acrylic resin paint: The water-based hydroxy acrylic resin that meets the standards in S2 is used to prepare water-based hydroxy acrylic resin paint; the preparation method is as follows: by weight, 70 parts of the water-based hydroxy acrylic resin that meets the standards in step S2, 12 parts of deionized water, 20 parts of red iron oxide, 4 parts of organic bentonite 801-A, 44 parts of fluorine-modified acrylic leveling agent LD-108, and 4 parts of AGITAN760 are mixed evenly, and then ground evenly with a sand mill to a fineness of less than 10 um;

[0076] S4: Preparation of water-based hydroxy acrylic resin coating: The water-based hydroxy acrylic resin paint prepared in S3 is mixed with Covestro XP2655 curing agent to obtain a water-based hydroxy acrylic resin coating. The preparation method is: Covestro XP2655 curing agent is diluted with propylene glycol methyl ether acetate to 60% solid content to obtain a curing agent solution, and then water-based hydroxy acrylic resin paint and water are added to the curing agent solution to obtain a water-based hydroxy acrylic resin coating, wherein the mass ratio of the water-based hydroxy acrylic resin paint, the curing agent solution and the deionized water is 100:24:16.

[0077] The preparation method of the above-mentioned water-resistant group surface modified silica particles is as follows: 26 parts of isophorone diisocyanate and 13 parts of octadecyl alcohol are added to a beaker by weight, heated to 70°C, and kept warm for 3 hours for grafting reaction, and then 60 parts of silane surface modified silica particles and 3 parts of dibutyltin dilaurate are added, stirred for reaction for 30 hours, cooled and filtered, washed three times with butyl acetate, and then dried to obtain water-resistant group surface modified silica particles.

[0078] The preparation method of the silane surface modified silica particles is as follows: in parts by weight, 18 parts of nano-SiO2 particles are added to 100 parts of a mixed solution of 50% ethanol and deionized water by mass, and ultrasonic dispersion is performed for 3 hours. Then, 10 parts of silane coupling agent KH-570 and 7 parts of 50% oxalic acid solution by mass are added, and ultrasonic dispersion is continued for 1 hour. Then, the particles are washed three times with a mixed solution of 50% ethanol and deionized water by mass to remove excess KH-570 and its by-products adsorbed on the surface of the nano-SiO2 particles. Then, the filtrate is placed in a vacuum drying oven and dried to obtain silane surface modified silica particles.

[0079] Example 4

[0080] A highly water-resistant water-soluble hydroxy acrylic resin is prepared from the following raw materials in parts by weight: 4 parts of propylene glycol methyl ether, 62 parts of mixed monomers, 5 parts of initiators, 6 parts of 2-perfluorooctylethanol, 12 parts of silicon dioxide particles with water-resistant group surfaces modified, 55 parts of deionized water and 2 parts of dimethylethanolamine neutralizer.

[0081] The mixed monomer is a mixture of 25 parts of methyl methacrylate, 10 parts of butyl acrylate, 5 parts of 2-ethylhexyl acrylate, 10 parts of hydroxyethyl methacrylate, 7 parts of butyl methacrylate and 5 parts of acrylic acid.

[0082] The initiator is a mixture of 2 parts of n-dodecyl mercaptan and 3 parts of benzoyl peroxide.

[0083] The preparation method of the above-mentioned water-based hydroxylated acrylic resin coating comprises the following steps:

[0084] S1. Preparation of water-based hydroxy acrylic resin: First, add alcohol ether solvent, 2-perfluorooctylethanol and water-resistant group surface modified silica particles to the reactor; then, raise the temperature from room temperature to 130°C, and stir the mixture at this temperature for 4 hours; then, add the mixed monomer and initiator to the reactor in a dropwise manner at the same time, ensuring that the dropwise addition process lasts for 4 hours; after the dropwise addition is completed, keep the temperature at 130°C and continue stirring for 1 hour to terminate the reaction. After the reaction is completed, the temperature is lowered to 90°C, and then dimethylethanolamine neutralizer is added and fully neutralized; then, 55 parts of deionized water are added and stirring is started to gradually emulsify the product, and this emulsification process needs to last for 2 hours. After emulsification is completed, continue stirring for 1.5 hours to ensure that the product is evenly mixed. Finally, the water-based hydroxy acrylic resin is obtained after cooling to room temperature.

[0085] S2. Detection of water-based hydroxyl acrylic resin: The water-based hydroxyl acrylic resin synthesized in S1 was tested, and the test indicators were: solid content mass fraction of 46%, viscosity of 5000 Pa.s, pH value of 9, hydroxyl content mass fraction of 3.2%. After the test met the standards, the next step was performed;

[0086] S3: Preparation of water-based hydroxy acrylic resin paint: The water-based hydroxy acrylic resin that meets the standards in S2 is used to prepare water-based hydroxy acrylic resin paint; the preparation method is as follows: by weight, 80 parts of the water-based hydroxy acrylic resin that meets the standards in step S2, 15 parts of deionized water, 25 parts of titanium dioxide, 5 parts of organic bentonite 801-A, 45 parts of fluorine-modified acrylic leveling agent LD-108, and 5 parts of AGITAN760 are mixed evenly, and then ground evenly with a sand mill to a fineness of less than 10 um;

[0087] S4: Preparation of water-based hydroxy acrylic resin coating: The water-based hydroxy acrylic resin paint prepared in S3 is mixed with Covestro XP2655 curing agent to obtain a water-based hydroxy acrylic resin coating. The preparation method is: Covestro XP2655 curing agent is diluted with propylene glycol methyl ether acetate to 60% solid content to obtain a curing agent solution, and then water-based hydroxy acrylic resin paint and water are added to the curing agent solution to obtain a water-based hydroxy acrylic resin coating, wherein the mass ratio of the water-based hydroxy acrylic resin paint, the curing agent solution and the deionized water is 100:25:20.

[0088] The preparation method of the above-mentioned water-resistant group surface modified silica particles is as follows: by weight, 30 parts of isophorone diisocyanate and 15 parts of octadecyl alcohol are added to a beaker, heated to 80°C, and kept warm for 4 hours for grafting reaction, and then 65 parts of silane surface modified silica particles and 4 parts of dibutyltin dilaurate are added, stirred for reaction for 36 hours, cooled and filtered, washed three times with butyl acetate, and then dried to obtain water-resistant group surface modified silica particles.

[0089] The preparation method of the silane surface modified silica particles is as follows: in parts by weight, 20 parts of nano-SiO2 particles are added to 100 parts of a mixed solution of 50% ethanol and deionized water by mass, ultrasonically dispersed for 4 hours, and then 12 parts of silane coupling agent KH-570 and 8 parts of 50% oxalic acid solution by mass are added, and ultrasonic dispersion is continued for 1 hour, and then washed three times with a mixed solution of 50% ethanol and deionized water by mass to remove excess KH-570 and its by-products adsorbed on the surface of the nano-SiO2 particles, and then the filtrate is placed in a vacuum drying oven for drying to obtain silane surface modified silica particles.

[0090] Example 5

[0091] The method is basically the same as Example 1, except that 12 parts of silica particles with water-resistant groups surface-modified are added to prepare the water-based hydroxylated acrylic resin.

[0092] Comparative Example 1

[0093] The method is basically the same as Example 1, except that 2-perfluorooctylethanol is not added in the preparation of the water-based hydroxylated acrylic resin.

[0094] Comparative Example 2

[0095] The method is basically the same as Example 1, except that isophorone diisocyanate is not added in the preparation of the silica particles with water-resistant group surface modification.

[0096] Comparative Example 3

[0097] The method is basically the same as Example 1, except that octadecyl alcohol is not added in the preparation of the silica particles with surface modified with water-resistant groups.

[0098] Comparative Example 4

[0099] The method is basically the same as Example 1, except that the water-resistant group-surface-modified silica particles are not added in the preparation of the water-based hydroxylated acrylic resin.

[0100] Characterization Tests:

[0101] In order to evaluate the chemical composition and structure of waterborne hydroxylated acrylic resin coatings, Fourier transform infrared spectroscopy (FTIR) technology was used and detailed tests were carried out in attenuated total reflectance (ATR) mode. During the test, a specific spectral recording range was set, namely 4000cm -1 Up to 500cm -1 To ensure that all important chemical functional groups that may exist in the coating are covered. At the same time, the spectral resolution is set to 4cm -1 , this is to obtain a high enough spectral resolution to accurately identify and analyze the various chemical components in the coating. In addition, in order to improve the accuracy and reliability of the test, the number of scans was set to 32 times. By taking the average value of multiple scans, noise and interference were effectively reduced, and the signal-to-noise ratio of the spectral data was improved. This test method provides detailed information on the chemical composition and structure of water-based hydroxylated acrylic resin coatings, which helps to better understand its performance and application characteristics.

[0102] like Figure 1 This is the FTIR spectrum of water-based hydroxylated acrylic resin coating. -1 The characteristic peak of carbonyl (C=O) appeared at 1093cm, which was the characteristic peak of perfluorooctyl ethanol reacting with the hydroxyl group in the hydroxy acrylic resin to form perfluorooctyl acetate. -1 The absorption peak at 950 cm is attributed to the stretching vibration of Si-O-Si, while the absorption peak at 950 cm -1 The absorption peak at 2954cm -1 、2923cm -1 and 2860cm -1 The peaks at 1647 cm represent the symmetric stretching vibration absorption peak of –CH3 and the asymmetric stretching vibration absorption peak of –CH2. -1 The vibration at 1573 cm -1 The peak at comes from the vibration of the C–N bond of the water-resistant groups on the silica surface.

[0103] Morphology observation: Field emission scanning electron microscopy (FE-SEM) is an advanced microscopic imaging technology, which is mainly used to observe the surface morphology and size of samples with high resolution. Among them, the S-4700 field emission scanning electron microscope produced by Hitachi is widely recognized for its excellent performance and stable operation. The present invention uses the S-4700 FE-SEM to observe the morphology of the surface modified silica particles with water-resistant groups and the surface of the water-based hydroxy acrylic resin coating.

[0104] Figure 2 The SEM morphology of silica particles with water-resistant group surface modification shows that the modified silica particles have uniform particle size and good dispersibility, which creates conditions for their uniform dispersion in the coating. Figure 3 This is the surface morphology of the coating after the water resistance test. It can be seen that the coating has no wrinkles or damage, proving that it has excellent water resistance.

[0105] Performance Test:

[0106] Contact angle: A contact angle analyzer is a device used to measure the contact angle between a liquid and a solid surface. It can effectively evaluate the wettability and hydrophobicity of a solid surface. Among them, the Phoenix300 contact angle analyzer, produced by SEO, is widely used in scientific research and industry. In specific studies, the device is used to measure the water contact angle (WCA) of coatings. Through this method, researchers can gain a deeper understanding of the interaction between coatings and water and their wetting properties, thereby providing strong data support for the optimization and application of material surfaces.

[0107] Water resistance: Referring to GB / T1733-93 "Determination of water resistance of paint film", the water-based hydroxy acrylic resin coating prepared in the examples and comparative examples was evenly coated on a 5cm*10cm wooden block for water resistance determination. After curing, it was immersed in water at a constant temperature of 23°C deionized water for 24 hours. The water absorption rate was calculated based on the mass change of the wooden block before and after soaking in water, thereby evaluating its water resistance, and observing whether the surface was damaged or wrinkled.

[0108] The properties of the coatings of Examples 1 to 5 and Comparative Examples 1 to 4 are summarized in Table 2.

[0109] Table 2 Performance summary of coatings of Examples 1 to 5 and Comparative Examples 1 to 4

[0110]

[0111] The main difference between Comparative Example 1 and Example 1 is whether 2-perfluorooctylethanol is added in the preparation of the water-based hydroxy acrylic resin. It can be seen from Table 2 that the addition of 2-perfluorooctylethanol can increase the water resistance of the coating.

[0112] The main difference between Comparative Example 2 and Example 1 is whether isophorone diisocyanate is added in the preparation of the water-resistant group surface-modified silica particles. It can be seen that without the addition of isophorone diisocyanate, octadecyl alcohol cannot be effectively grafted onto the silica particles. Therefore, it can be seen from Table 2 that the addition of isophorone diisocyanate can increase the water resistance of the coating.

[0113] The main difference between Comparative Example 3 and Example 1 is whether octadecyl alcohol is added to the surface-modified silica particles with water-resistant groups. Therefore, the surface of the silica particles is not grafted with octadecyl alcohol water-resistant groups. Therefore, it can be seen from Table 2 that the addition of octadecyl alcohol can increase the water resistance of the coating.

[0114] The main difference between Comparative Example 4 and Example 1 is whether water-resistant group-surface-modified silica particles are added in the preparation of the water-based hydroxylated acrylic resin. Therefore, it can be seen from Table 2 that water-resistant group-surface-modified silica particles can significantly improve the water resistance of the coating.

[0115] In summary, the water-resistant hydroxy acrylic resin in the present invention significantly improves water resistance by adding perfluorinated compounds, and at the same time, the silica particles are modified to form a hydrophobic protective film, thereby achieving a synergistic effect. This technology has important application value in the fields of coatings, waterproof materials, etc., and can provide excellent performance and effects in multiple fields.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that all equivalent structural changes made under the concept of the present invention and using the contents of the present invention specification and drawings should be covered within the scope of protection of the claims of the present invention.

Claims

1. A highly water-resistant water-soluble hydroxy acrylic resin, prepared from the following raw materials by weight: 4 parts of alcohol ether solvent, 62 parts of mixed monomer, 5 parts of initiator, 6 parts of 2-perfluorooctylethanol, 12 parts of water-resistant group surface-modified silica particles, 55 parts of deionized water and 2 parts of dimethylethanolamine neutralizer; 2-perfluorooctylethanol is added to the water-resistant hydroxy acrylic resin to synthesize perfluorooctyl acetate propylene; The preparation method of the water-resistant group surface-modified silica particles is as follows: by weight, 16 to 30 parts of isophorone diisocyanate and 8 to 15 parts of octadecyl alcohol are added to a beaker, heated to 65 to 80° C., kept warm for 2 to 4 hours for grafting reaction, and then 30 to 65 parts of silane surface-modified silica particles and 2 to 4 parts of dibutyltin dilaurate are added, stirred for reaction for 24 to 36 hours, cooled and filtered, washed three times with butyl acetate, and then dried to obtain water-resistant group surface-modified silica particles; The mass ratio of isophorone diisocyanate to octadecyl alcohol is 2:1; The preparation method of the silane surface modified silica particles is as follows: by weight, 10 to 20 parts of nano-SiO2 particles are added to 100 parts of a mixed solution of 50% ethanol and deionized water, ultrasonically dispersed for 2 to 4 hours, and then 5 to 12 parts of a silane coupling agent KH-570 and 3 to 8 parts of a 50% oxalic acid solution are added, and ultrasonic dispersion is continued for 1 hour, and then washed three times with a mixed solution of 50% ethanol and deionized water to remove excess KH-570 and its byproducts adsorbed on the surface of the nano-SiO2 particles, and then the filtrate is placed in a vacuum drying oven for drying to obtain silane surface modified silica particles; The preparation method of the highly water-resistant water-based hydroxy acrylic resin is as follows: 4 parts of alcohol ether solvent, 62 parts of mixed monomer, 5 parts of initiator, 6 parts of 2-perfluorooctylethanol, 12 parts of water-resistant group surface-modified silica particles, 55 parts of deionized water and 2 parts of dimethylethanolamine neutralizer are used to prepare the water-based hydroxy acrylic resin; The preparation method comprises: S11: Add alcohol ether solvent, 2-perfluorooctylethanol and silica particles with water-resistant group surface modification into the reaction kettle, raise the temperature from room temperature to 130°C, and stir for 2-4 hours; S12: adding the mixed monomer and the initiator to the reactor simultaneously by dropwise addition, and the dropwise addition lasts for 3 to 4 hours; S13: After the dropwise addition is completed, the temperature is kept at 0.5 to 1 h to terminate the reaction; S14: After the reaction is completed, the temperature is lowered to 90°C and dimethylethanolamine is added as a neutralizer. After sufficient neutralization, deionized water is added and stirred to emulsify the product. The emulsification time is 1 to 2 hours. S15: Continue stirring for 1 to 1.5 hours, then cool to room temperature to obtain a water-based hydroxy acrylic resin.

2. A highly water-resistant water-soluble hydroxy acrylic resin as claimed in claim 1, characterized in that: The alcohol ether solvent is glycol methyl ether acetate or propylene glycol methyl ether acetate.

3. A highly water-resistant water-soluble hydroxy acrylic resin according to claim 1, characterized in that: The mixed monomer is a mixture of 15-25 parts of methyl methacrylate, 5-10 parts of butyl acrylate, 2-5 parts of 2-ethylhexyl acrylate, 7-10 parts of hydroxyethyl methacrylate, 3-7 parts of butyl methacrylate and 2-5 parts of acrylic acid.

4. A highly water-resistant water-soluble hydroxy acrylic resin according to claim 1, characterized in that: The initiator is a mixture of 0.5-2 parts of n-dodecyl mercaptan and 1-3 parts of benzoyl peroxide.

5. A method for preparing the water-based hydroxylated acrylic resin coating according to claim 1, characterized in that: The following steps are involved: S1. Preparation of water-based hydroxy acrylic resin: 4 parts of alcohol ether solvent, 62 parts of mixed monomer, 5 parts of initiator, 6 parts of 2-perfluorooctylethanol, 12 parts of water-resistant group surface-modified silica particles, 55 parts of deionized water and 2 parts of dimethylethanolamine neutralizer were prepared into a water-based hydroxy acrylic resin; The preparation method comprises: S11: adding alcohol ether solvent, 2-perfluorooctylethanol and silica particles with water-resistant group surface modification into a reaction kettle, raising the temperature from room temperature to 130° C., and stirring for 2 to 4 hours; S12: adding the mixed monomer and the initiator to the reactor simultaneously by dropwise addition, and the dropwise addition lasts for 3 to 4 hours; S13: After the dropwise addition is completed, the temperature is kept at 0.5 to 1 h to terminate the reaction; S14: After the reaction is completed, the temperature is lowered to 90°C and dimethylethanolamine is added as a neutralizer. After sufficient neutralization, deionized water is added and stirred to emulsify the product. The emulsification time is 1 to 2 hours. S15: Continue stirring for 1 to 1.5 hours, then cool to room temperature to obtain a water-based hydroxy acrylic resin; S2. Testing of water-based hydroxyl acrylic resin: Testing the water-based hydroxyl acrylic resin synthesized in S1, including solid content, viscosity, pH value and hydroxyl value content. The next step is performed after the test meets the standards; S3: Preparation of water-based hydroxyl acrylic resin paint: The water-based hydroxyl acrylic resin that meets the test standards in S2 is used to prepare water-based hydroxyl acrylic resin paint; S4: Preparation of water-based hydroxy acrylic resin coating: The water-based hydroxy acrylic resin paint prepared in S3 is mixed with a water-based isocyanate curing agent to obtain a water-based hydroxy acrylic resin coating.

6. The method for preparing the water-based hydroxylated acrylic resin coating according to claim 5, characterized in that: The detection indicators of the water-based hydroxyl acrylic resin in S2 are: solid content mass fraction of 44~46%, viscosity of 2000~5000 Pa.s, pH value of 7~9, and hydroxyl content mass fraction of 2.3~3.2%.

7. The method for preparing a water-based hydroxylated acrylic resin coating according to claim 5, characterized in that: The preparation method of the water-based hydroxy acrylic resin paint in S3 is as follows: by weight, 60-80 parts of the water-based hydroxy acrylic resin that meets the standards in step S2, 10-15 parts of deionized water, 10-25 parts of pigment, 0.2-5 parts of dispersant, 0.2-5 parts of leveling agent, and 0.2-5 parts of defoaming agent are mixed evenly, and then ground evenly with a sand mill to a fineness of less than 10 um.

8. The method for preparing a water-based hydroxylated acrylic resin coating according to claim 7, characterized in that: The dispersant is organic bentonite 801-A; The leveling agent is fluorine-modified acrylate leveling agent LD-1084; The defoaming agent is AGITAN760; The pigment is any one of phthalocyanine blue, carbon black, medium chrome yellow, red iron oxide and titanium dioxide.

9. The method for preparing a water-based hydroxylated acrylic resin coating according to claim 5, characterized in that: The water-based isocyanate curing agent in S4 is selected from Covestro XP2655 curing agent; The preparation method of the water-based hydroxy acrylic resin coating in S4 is: diluting Covestro XP2655 curing agent with propylene glycol methyl ether acetate to a solid content of 60% to obtain a curing agent solution, and then adding water-based hydroxy acrylic resin paint and water to the curing agent solution to obtain a water-based hydroxy acrylic resin coating, wherein the mass ratio of the water-based hydroxy acrylic resin paint, the curing agent solution and deionized water is 100:20~25:10~20.

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