A kind of anticorrosive water-based acrylic resin and preparation method thereof

Abstract

The present invention discloses an anti-corrosion water-based acrylic resin and a preparation method thereof. The anti-corrosion water-based acrylic resin comprises the following components: butyl acrylate, methyl methacrylate, hydroxypropyl acrylate, glycidyl methacrylate, a modified nanosol, an emulsifier, an initiator, aqueous ammonia, and deionized water. The modified nanosol is obtained by first preparing an inorganic nanosol using a sol-gel method and then modifying the inorganic nanosol using a silane coupling agent. The present invention modifies the inorganic nanosol prepared by the sol-gel method using a silane coupling agent, and polymerizes the obtained modified nanosol with an acrylic acid monomer. The resulting water-based acrylic resin has excellent pencil hardness, adhesion, impact resistance, salt spray resistance, and high elongation at break, and has excellent overall performance, and can be widely used in the field of metal corrosion protection.

Description

Technical Field

[0001] The invention relates to an anti-corrosion water-based acrylic resin and a preparation method thereof, belonging to the technical field of acrylic resins. Background Art

[0002] Metal corrosion is a slow, irreversible, and destructive process that occurs when metal materials react with environmental media under certain conditions. Metal corrosion can cause economic losses and environmental pollution, presenting a significant challenge for countries worldwide. Applying a layer of water-based industrial coating to metal surfaces is an effective, cost-effective, and widely used method to prevent corrosion by blocking contact between corrosive media and the metal surface.

[0003] Water-based acrylic resin is the most widely used variety in water-based coatings. However, due to the presence of hydrophilic groups and lack of film density, water-based acrylic resin has poor barrier ability to corrosive media such as air and water, and cannot provide long-term and effective corrosion protection for metals and other substrates. This restricts the application of water-based acrylic resin in metal corrosion protection, so modification of water-based acrylic resin is imperative.

[0004] In recent years, organic-inorganic hybrid composite emulsions have attracted much attention from researchers because they have the advantages of easy processing, versatility and softness of organic materials, and the characteristics of wear resistance, high hardness and excellent corrosion resistance of inorganic nanomaterials, making them one of the popular materials for research. Inorganic nanoparticles have unique nano effects, such as small size effect, surface effect, synergistic effect, etc., and their particle size is usually 1-100nm, making them a popular research direction at home and abroad. The addition of inorganic nanoparticles can significantly improve the various properties of the original coating, such as wear resistance, water resistance, heat resistance, radiation resistance, aging resistance and corrosion resistance, and nanomaterials of different components have different degrees of influence. Adding inorganic nanoparticles (for example, nano zinc oxide, silicon dioxide, titanium dioxide, aluminum oxide, etc.) to acrylic resin to modify the acrylic resin is currently a commonly used method for modifying acrylic resin.

[0005] However, inorganic nanoparticles, especially the widely used nano-SiO2, have a large number of active hydroxyl groups on their surfaces, making them highly hydrophilic. This makes them prone to forming agglomerates or secondary aggregation, which is not conducive to dispersion and thus affects the structure and performance of the material. Therefore, it is necessary to modify the surface of inorganic nanoparticles to ensure their stable storage and improve their dispersibility in acrylic resins. Summary of the Invention

[0006] In view of the above problems existing in the prior art, the object of the present invention is to provide an anti-corrosion water-based acrylic resin and a preparation method thereof.

[0007] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows:

[0008] An anti-corrosion water-based acrylic resin having the following composition and proportions:

[0009] Butyl acrylate: 12.41wt% to 14.12wt%;

[0010] Methyl methacrylate: 5.54wt% to 6.30wt%;

[0011] Hydroxypropyl acrylate: 3.93wt%~4.47wt%;

[0012] Glycidyl methacrylate: 1.8 wt% to 2.05 wt%;

[0013] Modified nanosol: 0.48wt%~14.28wt%;

[0014] Emulsifier: 0.37wt%~0.42wt%;

[0015] Initiator: 0.06wt% to 0.07wt%;

[0016] Ammonia water: 0.01wt% to 0.05wt%;

[0017] Deionized water: 63.29wt% to 72.01wt%;

[0018] The modified nano sol is prepared by firstly adopting a sol method to prepare an inorganic nano sol, and then modifying the inorganic nano sol with a silane coupling agent.

[0019] In one embodiment, the emulsifier is a composition of an anionic emulsifier and a nonionic emulsifier, the anionic emulsifier is selected from any one of disodium dodecyl diphenyl ether sulfonate, sodium dodecylbenzene sulfonate, and sodium lauryl sulfate, and the nonionic emulsifier is selected from any one of alkylphenol polyoxyethylene ether (OP-10), Tween 20, and Tween 80, wherein the mass ratio of anionic emulsifier to nonionic emulsifier is 2:1.

[0020] In one embodiment, the initiator is any one of persulfate, hydrogen peroxide, dibenzoyl peroxide and tert-butyl peroxide hydroxide, and the persulfate is selected from any one of sodium persulfate, potassium persulfate and ammonium persulfate.

[0021] In one embodiment, the silane coupling agent is selected from any one of KH570, KH560, and KH550.

[0022] In one embodiment, the modified nano-sol is a modified nano-SiO2 sol, a modified nano-TiO2 sol, or a combination of a modified nano-SiO2 sol and a modified nano-TiO2 sol.

[0023] In a preferred embodiment, in the composition of the modified nano-SiO2 sol and the modified nano-TiO2 sol, the molar ratio of the modified nano-SiO2 sol to the modified nano-TiO2 sol is 3:1.

[0024] A preferred embodiment, the preparation of the modified nano-SiO2 sol comprises the following operations:

[0025] a) adding anhydrous ethanol, deionized water, and aqueous ammonia to a reaction vessel and stirring at room temperature for 10 to 15 minutes to obtain a mixed solution;

[0026] b) heating the mixture to 55-65° C., adding anhydrous ethanol containing ethyl orthosilicate to the mixed solution obtained in step a), stirring and reacting for 2-3 hours to obtain a nano-SiO sol;

[0027] c) heating the reaction vessel to 90-95° C., adding an ethanol aqueous solution containing a silane coupling agent to the reaction vessel of the nano-SiO 2 sol obtained in step b), and stirring the reaction for 5-6 hours to obtain a modified nano-SiO 2 sol.

[0028] In a preferred embodiment, in step a), the volume ratio of anhydrous ethanol: deionized water: ammonia water is (112.0-115.0): (112.0-115.0): (13.5-15.0), and more preferably 25:25:3.

[0029] In a preferred embodiment, the volume ratio of ethyl orthosilicate in step b) to ammonia water in step a) is 1:1.

[0030] In a preferred embodiment, in step b), the volume ratio of ethyl orthosilicate to anhydrous ethanol is (13.5-15.0): (150.0-160.0).

[0031] In a preferred embodiment, the molar ratio of the silane coupling agent in step c) to the ethyl orthosilicate in step b) is 0.5:1.

[0032] In a preferred embodiment, in step c), the volume ratio of silane coupling agent: ethanol aqueous solution is (7.0-8.0): (40.0-44.0); in the ethanol aqueous solution, the volume ratio of anhydrous ethanol: deionized water is 3:1.

[0033] A preferred embodiment, the preparation of the modified nano-TiO2 sol comprises the following operations:

[0034] ① Add butyl titanate and anhydrous ethanol into a reaction vessel and stir at room temperature to mix them evenly to obtain a mixed solution A;

[0035] ② Mix anhydrous ethanol, deionized water and hydrochloric acid at room temperature to obtain mixed solution B;

[0036] ③ Add mixed solution B dropwise to mixed solution A at room temperature. After the addition is complete, stir and react at room temperature for 0.5 to 1 hour to obtain nano-TiO2 sol;

[0037] ④ Add silane coupling agent dropwise to the reaction vessel of the nano-TiO2 sol obtained in step ③. After the addition is completed, the resulting reactant is stirred and reacted at room temperature for 23 to 25 hours, and then heated to 90 to 95°C for 1 to 2 hours to obtain a modified nano-TiO2 sol.

[0038] In a preferred embodiment, in step ①, the volume ratio of butyl titanate: anhydrous ethanol is 1:1.

[0039] In a preferred embodiment, in step ②, the volume ratio of anhydrous ethanol: deionized water: hydrochloric acid is (25.0-27.0): (25.0-27.0): (1.6-2.0), and more preferably 25:25:2.

[0040] In a preferred embodiment, the molar ratio of the silane coupling agent in step ④ to the butyl titanate in step ① is 0.5:1.

[0041] A method for preparing the anticorrosive water-based acrylic resin of the present invention comprises the following steps:

[0042] 1) adding a proportion of emulsifier, a portion of deionized water and a proportion of modified nanosol into a pre-emulsification reactor, stirring at 28-30° C. to mix uniformly to obtain a mixed solution;

[0043] 2) adding a proportion of butyl acrylate, methyl methacrylate, hydroxypropyl acrylate, and glycidyl methacrylate to the mixed solution obtained in step 1), and pre-emulsifying at 28-30° C. for 0.5-1 hour to obtain a monomer pre-emulsion;

[0044] 3) dissolving a proportion of the initiator in a portion of the proportion of deionized water to obtain an initiator solution;

[0045] 4) adding the initiator solution obtained in step 3) into the polymerization reactor, then slowly adding 2 / 3 of the monomer pre-emulsion obtained in step 2) into the polymerization reactor, and then heating to 82-85° C.;

[0046] 5) After the temperature stabilizes at 82-85° C., the remaining monomer pre-emulsion is delivered to the polymerization reactor using a peristaltic pump. During the delivery process, the peristaltic pump silicone tube in the polymerization reactor is always below the liquid level. After the monomer pre-emulsion is delivered, the pre-emulsification reactor is rinsed with the remaining amount of deionized water and then delivered to the polymerization reactor again using the peristaltic pump;

[0047] 6) Keeping the mixture at 82-85° C. for 2 hours, then cooling to room temperature, and adjusting the pH of the mixture to 7-8 with aqueous ammonia to obtain an anticorrosive water-based acrylic resin.

[0048] In a preferred embodiment, in step 1), the amount of the emulsifier added is 2.0 wt% of the monomer mass.

[0049] In a preferred embodiment, in step 2), the molar ratio of methyl methacrylate (MMA): butyl acrylate (BA): glycidyl methacrylate (GMA): hydroxypropyl acrylate (hydroxypropyl acrylate) is 4:7:1:2, wherein the molecular weight of methyl methacrylate is 100.116 g / mol, the molecular weight of butyl acrylate is 128.169 g / mol, the molecular weight of glycidyl methacrylate is 130.142 g / mol, and the molecular weight of hydroxypropyl acrylate is 142.15 g / mol.

[0050] In a preferred embodiment, in step 3), the amount of the initiator added is 5.0 wt% of the monomer mass.

[0051] In a preferred embodiment, in step 4), the temperature is slowly increased to 82-85°C at a heating rate of 5°C / min.

[0052] In a preferred embodiment, in step 5), the rate of the peristaltic pump is 4 to 6 mL / min.

[0053] Compared with the prior art, the present invention has the following significant beneficial effects:

[0054] The present invention first prepares an inorganic nanosol by a sol method, then modifies the inorganic nanosol with a silane coupling agent to obtain a modified nanosol, and polymerizes the obtained modified nanosol with an acrylic monomer. As a result, the water-based acrylic resin of the present invention has excellent pencil hardness, adhesion, impact resistance, salt spray resistance and high elongation at break, and has excellent comprehensive performance. It can be widely used in the field of metal corrosion protection and has great potential value. In addition, the preparation method of the present invention is economical and practical, with a simple preparation process and low cost. It does not require special equipment and harsh conditions, is easy to achieve large-scale production, and has strong industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 IR spectra of nano-SiO2 and KH570@SiO2 prepared in Example 1 of the present invention;

[0056] Figure 2 XRD patterns of nano-SiO2 and KH570@SiO2 prepared in Example 1 of the present invention;

[0057] Figure 3The SEM images of nano-SiO2 and KH570@SiO2 prepared in Example 1 of the present invention are shown;

[0058] Figure 4 The following are photos of the nano-SiO2 sol and KH570@SiO2 sol prepared in Example 1 of the present invention;

[0059] Figure 5 The water contact angle test diagram of the nano-SiO2 sol and KH570@SiO2 sol prepared in Example 1 of the present invention;

[0060] Figure 6 This is a photo of the antiseptic water-based acrylic resin prepared in Example 1 of the present invention;

[0061] Figure 7 The infrared spectra of nano-TiO2 and KH570@TiO2 prepared in Example 2 of the present invention are shown;

[0062] Figure 8 XRD patterns of nano-TiO2 and KH570@TiO2 prepared in Example 2 of the present invention;

[0063] Figure 9 SEM images of nano-TiO2 and KH570@TiO2 prepared in Example 2 of the present invention;

[0064] Figure 10 This is a photo of the antiseptic water-based acrylic resin prepared in Example 3 of the present invention;

[0065] Figure 11 This is a photo of the comparative acrylic resin prepared in Comparative Example 1 of the present invention;

[0066] Figure 12 The XRD pattern of the hydrothermal SiO2 nanoparticles prepared in Comparative Example 3 of the present invention;

[0067] Figure 13 This is a SEM image of the hydrothermal SiO2 nanoparticles prepared in Comparative Example 3 of the present invention;

[0068] Figure 14 This is a photo of the hydrothermal SiO2 nanoparticles prepared in Comparative Example 3 of the present invention;

[0069] Figure 15 This is a photo of the comparative acrylic resin prepared by the grafting method in Comparative Example 4 of the present invention. DETAILED DESCRIPTION

[0070] The technical scheme of the present invention is further described in detail and completely below with reference to the examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the invention. The experimental methods in the following examples, for which specific conditions are not specified, are generally carried out under conventional conditions or as recommended by the manufacturer.

[0071] Example 1

[0072] 1. Preparation of modified nano-SiO2 sol:

[0073] a) adding anhydrous ethanol (112.5 mL), deionized water (112.5 mL) and aqueous ammonia (13.5 mL) to a reaction vessel and stirring at room temperature (the room temperature in the present invention is 25° C.) for 15 minutes to obtain a mixed solution;

[0074] b) heating the mixture to 60° C., adding ethyl orthosilicate (13.5 mL) dissolved in anhydrous ethanol (150.0 mL) to the mixed solution obtained in step a), and stirring the mixture for 2 hours (stirring speed: 450 rpm / min) to obtain a nano-SiO sol;

[0075] c) raising the temperature to 90° C., adding a silane coupling agent KH570 (7.2 mL) dissolved in an ethanol aqueous solution (47.2 mL, anhydrous ethanol:deionized water volume ratio of 3:1) to the reaction vessel of the nano-SiO sol obtained in step b), and stirring the reaction for 5 hours to obtain a modified nano-SiO sol, which was recorded as KH570@SiO sol.

[0076] 2. Preparation of anti-corrosion water-based acrylic resin:

[0077] 1) OP-10 (1.0 g), sodium lauryl sulfate (1.0 g), deionized water (100.0 mL), and KH570@SiO2 sol (58.0 mL) were added to a pre-emulsification reactor and stirred at 28°C (at a stirring speed of 450 rpm / min) to mix uniformly to obtain a mixed solution;

[0078] 2) Butyl acrylate (BA, 50.00 g), methyl methacrylate (MMA, 22.32 g), hydroxypropyl acrylate (HPA, 15.84 g), and glycidyl methacrylate (GMA, 7.26 g) were added to the mixed solution obtained in step 1), and pre-emulsified at 28° C. for 30 minutes (stirring speed was 12000 rpm / min during the pre-emulsification process) to obtain a monomer pre-emulsion solution for later use;

[0079] 3) Dissolve an initiator (potassium persulfate, 0.25 g) in deionized water (150.0 mL) to prepare an initiator solution;

[0080] 4) adding the initiator solution obtained in step 3) to the polymerization reactor, and then slowly adding 2 / 3 of the monomer pre-emulsion obtained in step 2) to the polymerization reactor, and then slowly heating the reactor to 82° C. at a heating rate of 5° C. / min. During this process, the shear rate was 450 rpm / min;

[0081] 5) After the temperature stabilized at 82° C., the remaining monomer pre-emulsion was transferred to the polymerization reactor using a peristaltic pump. During the transfer process, the peristaltic pump silicone tube in the polymerization reactor was always below the liquid level. The peristaltic pump rate was 4.0 mL / min and the shear rate was 450 rpm / min. After the monomer pre-emulsion was transferred, the pre-emulsion reactor was rinsed with deionized water (5.0 mL) and then transferred to the polymerization reactor again using the peristaltic pump;

[0082] 6) The mixture was kept at 82° C. for 2 hours and then cooled to room temperature. The pH of the mixture was adjusted to about 7 with aqueous ammonia to obtain an anticorrosive water-based acrylic resin.

[0083] The nano-SiO2 sol and KH570@SiO2 sol obtained in step b) and step c) were placed in a drying oven at 60°C for 24 hours to obtain nano-SiO2 solid and KH570@SiO2 solid. The nano-SiO2 solid and KH570@SiO2 solid were washed with alcohol three times by centrifugation to remove excess KH570 and other impurities, and the SiO2 powder and KH570@SiO2 powder for testing were obtained. The SiO2 powder and KH570@SiO2 powder were tested by infrared spectroscopy and XRD. The test results are as follows: Figure 1 and Figure 2 shown.

[0084] Figure 1 The infrared spectra of nano-SiO2 and KH570@SiO2 prepared in this embodiment are as follows; Figure 1 It can be seen that the modified SiO2@KH570 has not only the peak of SiO2, but also the peak at 2950cm -1 The characteristic peak of methyl appeared near 2850cm -1 The characteristic peak of methylene appears near 1700 cm -1 The characteristic peak of C=O appears near 1631cm -1 The appearance of a C=C stretching vibration peak nearby indicates the presence of organic matter on the surface of the modified nano-SiO2. That is, after the hydrolysis of the silane coupling agent KH570, a dealcoholization reaction occurs with the ─OH group on the surface of the nano-SiO2 particles to form a covalent bond. The appearance of the characteristic peak indicates that KH570 is successfully grafted to the SiO2 surface in this embodiment.

[0085] Figure 2 The XRD patterns of nano-SiO2 and KH570@SiO2 prepared in this embodiment are as follows; Figure 2It can be seen that compared with the PDF standard card, no new diffraction peaks appear in the SiO2@KH570 during the modification process, and there is a broader diffraction peak at 2θ=21.98°, which is consistent with the SiO2 spectrum, indicating that the KH570 modified nano-SiO2 in this embodiment does not change its crystal form and phase composition.

[0086] The SiO2 powder and KH570@SiO2 powder obtained after drying and alcohol washing were ultrasonically dispersed in ethanol aqueous solution for 10 minutes respectively. After uniform dispersion, their micromorphology was observed by scanning electron microscope. The results are as follows: Figure 3 shown.

[0087] Figure 3 The SEM images of nano-SiO2 and KH570@SiO2 prepared in this embodiment; Figure 3 It can be seen that most of the nano-SiO2 particles are spherical, the particle size of the agglomerates is uneven, and the number of single particles contained in each agglomerate is also very different. The dispersibility of the nano-SiO2 modified with KH570 has been improved to some extent. The particles in the field of view exist in agglomerates of relatively uniform size, but the distribution is relatively loose. The agglomerates are no longer tightly entangled together, but are separated by some gaps, and the agglomerates are in a dispersed state. This shows that KH570 can improve the dispersibility of nano-SiO2 to a certain extent; at the same time, compared with the unmodified SiO2 particles, a soft "film"-like wrapping state can be observed on the surface of the modified agglomerates. It can be inferred that this is because after the nano-SiO2 is modified with KH570, KH570 is grafted and coated on the surface of the nano-SiO2, thus forming a "fluffy" state in the aqueous phase system.

[0088] Figure 4 The actual photos of the nano-SiO2 sol and KH570@SiO2 sol prepared in this example are shown in Figure 2. Figure 4 It can be seen that compared with the nano-SiO2 sol, the KH570@SiO2 sol after KH570 grafting is darker white and opaque. This is because the chemical structure of KH570 contains organic chains, which affects the optical properties of the sol and causes the color to change. The color change indicates that KH570 has been successfully grafted to the SiO2 surface, changing the overall optical properties of the sol through chemical reactions.

[0089] Figure 5 The water contact angle test diagram of the nano-SiO2 sol and KH570@SiO2 sol prepared in this embodiment; Figure 5 It can be seen that the hydrophilic nano-SiO2 sol was modified into the hydrophobic KH570@SiO2 sol, which is more conducive to the subsequent emulsion polymerization with acrylic resin.

[0090] In addition, after testing: in this embodiment, the particle size of the prepared nano-SiO2 sol is 62nm, and the particle size of the KH570@SiO2 sol is 53nm. Compared with the unmodified SiO2 sol, the particle size of the sol particles modified by KH570 is smaller. This is because the agglomeration effect between SiO2 particles is significantly improved after modification by KH570, and the particle size is reduced.

[0091] In this embodiment, the surface hydroxyl value of the prepared nano-SiO2 sol is 1.14, and the surface hydroxyl value of the KH570@SiO2 sol is 0.13. Compared with the unmodified nano-SiO2 sol, the surface hydroxyl value of the KH570@SiO2 sol modified with KH570 becomes smaller, which also indirectly indicates that after the introduction of KH570, the hydrophobicity of KH570@SiO2 is greatly enhanced compared with the unmodified SiO2.

[0092] The monomer conversion rate during the preparation of the acrylic resin in this example was tested using the following method: a certain amount of the emulsion sample was added to a weighed container m1, and a small amount of hydroquinone was added dropwise, with the total weight m2 being included. The container was then placed in an oven and dried to a constant weight. After cooling to room temperature, the weight m3 was recorded again, and the monomer conversion rate Y was calculated using the following formula:

[0093]

[0094] In the formula: m1 represents the weight of the container, g; m2 represents the mass of the sample, g; m3 represents the mass of the sample after drying to constant weight, g; A represents the total mass of the feed, g; B represents the mass of non-volatile matter in the feed, g; C represents the total mass of the monomers in the feed, g.

[0095] The test results show that in this embodiment, the monomer conversion rate is 99.90%, indicating that all acrylic acid monomers have participated in the polymerization reaction and there are relatively few free monomers.

[0096] Figure 6 This is a photo of the antiseptic waterborne acrylic resin prepared in this embodiment. Figure 6 It can be seen that the modified acrylic emulsion prepared in this embodiment has the appearance of a milky white liquid with a blue light. The blue light is a phenomenon of the emulsion caused by light scattering when the emulsion latex particle size is less than 400 nm, and the intensity of the blue light is closely related to the particle size of the emulsion. The smaller the particle size, the more significant the blue light.

[0097] Furthermore, testing showed that the solid content of the modified acrylic emulsion prepared in this example was 38.27%, close to the theoretical solid content; and no precipitation occurred during storage at room temperature for half a year, indicating that the modified acrylic emulsion had excellent storage stability.

[0098] The prepared anti-corrosion water-based acrylic resin was coated on a substrate with a wet film thickness of 100±10 μm. The resin was first dried and cured at room temperature for 72 hours and then placed in a 60°C oven for 10 days to form a film. The performance of the film-formed anti-corrosion water-based acrylic resin was then tested. The test results are shown in Table 1.

[0099] Example 2

[0100] 1. Preparation of modified nano-TiO2 sol:

[0101] ① Add butyl titanate (50.0 mL) and anhydrous ethanol (50.0 mL) into a reaction vessel and stir at room temperature to mix them uniformly to obtain a mixed solution A;

[0102] ② Mix anhydrous ethanol (25.0 mL), deionized water (25.0 mL) and hydrochloric acid (hydrochloric acid concentration is 37.5%, 1.6 mL) at room temperature to obtain mixed solution B. The obtained mixed solution B can be placed in a constant pressure separatory funnel for later use;

[0103] ③ Add the mixed solution B dropwise to the mixed solution A at room temperature, and control the dripping to be completed within 15 minutes. After the dripping is completed, stir and react at room temperature for 0.5 hours to obtain a nano-TiO2 sol;

[0104] ④ Add silane coupling agent (7.2 mL) dropwise to the reaction vessel of the nano-TiO2 sol obtained in step ③. After the addition is complete, the reactant is stirred and reacted at room temperature for 24 hours, and then heated to 90°C for 1.5 hours to obtain a modified nano-TiO2 sol, which is recorded as KH570@TiO2 sol.

[0105] 2. Preparation of anti-corrosion water-based acrylic resin:

[0106] 1) OP-10 (1.0 g), sodium lauryl sulfate (1.0 g), deionized water (100.0 mL), and KH570@TiO2 sol (2.2 mL) were added to a pre-emulsification reactor and stirred at 28°C (450 rpm / min) to mix uniformly to obtain a mixed solution;

[0107] 2) Butyl acrylate (BA, 50.00 g), methyl methacrylate (MMA, 22.32 g), hydroxypropyl acrylate (HPA, 15.84 g), and glycidyl methacrylate (GMA, 7.26 g) were added to the mixed solution obtained in step 1), and pre-emulsified at 28° C. for 30 minutes (stirring speed was 12000 rpm / min during the pre-emulsification process) to obtain a monomer pre-emulsion solution for later use;

[0108] 3) Dissolve an initiator (potassium persulfate, 0.25 g) in deionized water (150.0 mL) to prepare an initiator solution;

[0109] 4) adding the initiator solution obtained in step 3) to the polymerization reactor, and then slowly adding 2 / 3 of the monomer pre-emulsion obtained in step 2) to the polymerization reactor, and then slowly heating the reactor to 82° C. at a heating rate of 5° C. / min. During this process, the shear rate was 450 rpm / min;

[0110] 5) After the temperature stabilized at 82° C., the remaining monomer pre-emulsion was transferred to the polymerization reactor using a peristaltic pump. During the transfer process, the peristaltic pump silicone tube in the polymerization reactor was always below the liquid level. The peristaltic pump rate was 4.0 mL / min and the shear rate was 450 rpm / min. After the monomer pre-emulsion was transferred, the pre-emulsion reactor was rinsed with deionized water (5.0 mL) and then transferred to the polymerization reactor again using the peristaltic pump;

[0111] 6) The mixture was kept at 82° C. for 2 hours and then cooled to room temperature. The pH of the mixture was adjusted to about 7 with aqueous ammonia to obtain an anticorrosive water-based acrylic resin.

[0112] The nano-TiO2 sol and KH570@TiO2 sol obtained in step b) and step c) were placed in a drying oven at 60°C for 24 hours to obtain nano-TiO2 solid and KH570@TiO2 solid. The nano-TiO2 solid and KH570@TiO2 solid were centrifuged and washed with alcohol three times to remove excess KH570 and other impurities, thereby obtaining TiO2 powder and KH570@TiO2 powder for testing. The TiO2 powder and KH570@TiO2 powder were subjected to infrared spectroscopy and XRD tests, and the test results were as follows: Figure 7 and Figure 8 shown.

[0113] Figure 7 The infrared spectra of nano-TiO2 and KH570@TiO2 prepared in this embodiment are as follows; Figure 7 Visible, 641.8cm -1 It is the absorption peak of Ti-O and Ti-O-Ti bonds. After modification, it is at 1100.2cm -1 The stretching vibration peak of Si-O in KH570 appears at 1720.1cm -1 A weak peak appeared at 2850.3 cm, corresponding to the stretching vibration peak of C=O in KH570. -1 and 2925.4cm -1 The stretching vibration peaks of -CH2- and -CH3 on KH570 appeared at , which shows that the modification of TiO2 by KH570 in this example was successful.

[0114] Figure 8 The XRD patterns of nano-TiO2 and KH570@TiO2 prepared in this example are as follows; Figure 8It can be seen that there are diffraction peaks at 2θ values ​​of 25.2, 37.7, 48.0, 54.2, 55.1, 62.4, 68.7, 70.3, and 75.1, which are basically consistent with the standard peak positions of anatase TiO2. It can be determined that the products are all anatase titanium dioxide, and compared with the spectrum of unmodified TiO2, KH570@TiO2 does not have other impurity phases, indicating that KH570 modification does not change the TiO2 crystal structure and phase composition; the diffraction peaks in the figure are narrow and sharp, indicating that the product has excellent crystallinity; there are no other impurity phases in the figure, indicating that the product is of high purity; the peak shape in the figure is relatively wide, indicating that the product particle size is very small.

[0115] The TiO2 powder and KH570@TiO2 powder obtained after drying and alcohol washing were ultrasonically dispersed in ethanol aqueous solution for 10 minutes respectively. After uniform dispersion, their micromorphology was observed by scanning electron microscopy. The results are as follows: Figure 9 shown.

[0116] Figure 9 The SEM images of nano-TiO2 and KH570@TiO2 prepared in this example are as follows: Figure 9 It can be seen that TiO2 has extremely strong agglomeration before modification, and the shape of the particles is basically invisible. After modification, the agglomeration performance is improved and the outline of the particles can be seen.

[0117] In this embodiment, the particle size of the TiO2 sol was measured to be 1990 nm using a laser force analyzer, and the particle size of the KH570@TiO2 sol was measured to be 898 nm using a laser particle size analyzer. Compared with the particle size before and after modification, the particle size decreased by about half, indicating that the agglomeration effect of TiO2 was significantly improved after modification with KH570. When used in the preparation of acrylic resin, it is easier to graft and polymerize with acrylic monomers without flocculation, thereby improving the monomer conversion rate of the subsequent emulsion.

[0118] The monomer conversion rate during the preparation of the acrylic resin in this embodiment was tested (the testing method for the monomer conversion rate was specifically described). The test results showed that in this embodiment, the monomer conversion rate was 96.23%, indicating that all the acrylic monomers in this embodiment had participated in the polymerization reaction and there were few free monomers.

[0119] The prepared anti-corrosion water-based acrylic resin was coated on a substrate with a wet film thickness of 100±10 μm. The resin was first dried and cured at room temperature for 72 hours and then placed in a 60°C oven for 10 days to form a film. The performance of the film-formed anti-corrosion water-based acrylic resin was then tested. The test results are shown in Table 1.

[0120] Example 3

[0121] 1. Preparation of modified nano-SiO2 sol:

[0122] a) adding anhydrous ethanol (112.5 mL), deionized water (112.5 mL) and aqueous ammonia (13.5 mL) to a reaction vessel and stirring at room temperature (the room temperature in the present invention is 25° C.) for 15 minutes to obtain a mixed solution;

[0123] b) heating the mixture to 60° C., adding ethyl orthosilicate (13.5 mL) dissolved in anhydrous ethanol (150.0 mL) to the mixed solution obtained in step a), and stirring the mixture for 2 hours (stirring speed: 400 rpm / min) to obtain a nano-SiO sol;

[0124] c) raising the temperature to 91° C., adding silane coupling agent KH570 (7.2 mL) dissolved in ethanol aqueous solution (47.2 mL, anhydrous ethanol:deionized water volume ratio of 3:1) to the reaction vessel of the nano-SiO sol obtained in step b), and stirring the reaction for 5 hours to obtain a modified nano-SiO sol, which was recorded as KH570@SiO sol.

[0125] 2. Preparation of modified nano-TiO2 sol:

[0126] ① Add butyl titanate (50.0 mL) and anhydrous ethanol (50.0 mL) into a reaction vessel and stir at room temperature to mix them uniformly to obtain a mixed solution A;

[0127] ② Mix anhydrous ethanol (25.0 mL), deionized water (25.0 mL) and hydrochloric acid (hydrochloric acid concentration is 37.7%, 1.6 mL) at room temperature to obtain mixed solution B. The obtained mixed solution B can be placed in a constant pressure separatory funnel for later use;

[0128] ③ Add the mixed solution B dropwise to the mixed solution A at room temperature, and complete the addition within 15 minutes. After the addition is complete, stir the mixture at room temperature for 0.5 hours (stirring speed is 400 rpm / min) to obtain a nano-TiO2 sol;

[0129] ④ Add silane coupling agent (7.2 mL) dropwise to the reaction vessel of the nano-TiO2 sol obtained in step ③. After the addition is complete, the reactant is stirred and reacted at room temperature for 24 hours, and then heated to 91°C for 1.5 hours to obtain a modified nano-TiO2 sol, which is recorded as KH570@TiO2 sol.

[0130] 3. Preparation of anti-corrosion water-based acrylic resin:

[0131] 1) OP-10 (1.0 g), sodium lauryl sulfate (1.0 g), deionized water (100.0 mL), KH570@TiO2 sol (6.62 mL), and KH570@SiO2 sol (11.53 mL) (the molar ratio of KH570@TiO2 to KH570@SiO2 was 3:1) were added to a pre-emulsification reactor and stirred at 28°C (400 rpm / min) to mix uniformly to obtain a mixed solution;

[0132] 2) Butyl acrylate (BA, 50.00 g), methyl methacrylate (MMA, 22.32 g), hydroxypropyl acrylate (HPA, 15.84 g), and glycidyl methacrylate (GMA, 7.26 g) were added to the mixed solution obtained in step 1), and pre-emulsified at 28° C. for 30 minutes (stirring speed was 12000 rpm / min during the pre-emulsification process) to obtain a monomer pre-emulsion solution for later use;

[0133] 3) Dissolve an initiator (potassium persulfate, 0.25 g) in deionized water (150.0 mL) to prepare an initiator solution;

[0134] 4) adding the initiator solution obtained in step 3) to the polymerization reactor, then slowly adding 2 / 3 of the monomer pre-emulsion obtained in step 2) to the polymerization reactor, and then slowly heating the reactor to 85° C. at a heating rate of 5° C. / min. During this process, the shear rate was 400 rpm / min;

[0135] 5) After the temperature stabilized at 85° C., the remaining monomer pre-emulsion was transferred to the polymerization reactor using a peristaltic pump. During the transfer process, the peristaltic pump silicone tube in the polymerization reactor was always below the liquid level. The peristaltic pump rate was 4.0 mL / min and the shear rate was 400 rpm / min. After the monomer pre-emulsion was transferred, the pre-emulsion reactor was rinsed with deionized water (5.0 mL) and then transferred to the polymerization reactor again using the peristaltic pump;

[0136] 6) The mixture was kept at 82° C. for 2 hours and then cooled to room temperature. The pH of the mixture was adjusted to about 7 with aqueous ammonia to obtain an anticorrosive water-based acrylic resin.

[0137] The monomer conversion rate during the preparation of the acrylic resin in this embodiment was tested. The test results showed that in this embodiment, the monomer conversion rate was 98.95%, indicating that all acrylic monomers had participated in the polymerization reaction and there were relatively few free monomers.

[0138] Figure 10 is a physical photo of the antiseptic water-based acrylic resin prepared in this embodiment; Figure 10 It can be seen that the acrylic resin prepared in this embodiment is in the form of an emulsion.

[0139] After testing, the anti-corrosion water-based acrylic resin prepared in this embodiment had a solid content of 47.76%, which is close to the theoretical solid content; when stored at room temperature, no precipitation occurred within half a year, indicating that it has excellent storage stability.

[0140] The prepared anti-corrosion water-based acrylic resin was coated on a substrate with a wet film thickness of 100±10 μm. The resin was first dried and cured at room temperature for 72 hours and then placed in a 60°C oven for 10 days to form a film. The performance of the film-formed anti-corrosion water-based acrylic resin was then tested. The test results are shown in Table 1.

[0141] Comparative Example 1

[0142] The difference between this comparative example and the embodiment is that no modified nanosol is added during the preparation of the acrylic resin. Specifically, the preparation process of the comparative acrylic resin is as follows:

[0143] 1) OP-10 (1.0 g), sodium lauryl sulfate (1.0 g), and deionized water (100.0 mL) were added to a pre-emulsification reactor and stirred at 28° C. (at a stirring speed of 450 rpm / min) to mix uniformly to obtain a mixed solution;

[0144] 2) Butyl acrylate (BA, 50.00 g), methyl methacrylate (MMA, 22.32 g), hydroxypropyl acrylate (HPA, 15.84 g), and glycidyl methacrylate (GMA, 7.26 g) were added to the mixed solution obtained in step 1), and pre-emulsified at 28° C. for 30 minutes (stirring speed was 12000 rpm / min during the pre-emulsification process) to obtain a monomer pre-emulsion solution for later use;

[0145] 3) Dissolve an initiator (potassium persulfate, 0.25 g) in deionized water (150.0 mL) to prepare an initiator solution;

[0146] 4) adding the initiator solution obtained in step 3) to the polymerization reactor, and then slowly adding 2 / 3 of the monomer pre-emulsion obtained in step 2) to the polymerization reactor, and then slowly heating the reactor to 82° C. at a heating rate of 5° C. / min. During this process, the shear rate was 450 rpm / min;

[0147] 5) After the temperature stabilized at 82° C., the remaining monomer pre-emulsion was transferred to the polymerization reactor using a peristaltic pump. During the transfer process, the peristaltic pump silicone tube in the polymerization reactor was always below the liquid level. The peristaltic pump rate was 4.0 mL / min and the shear rate was 450 rpm / min. After the monomer pre-emulsion was transferred, the pre-emulsion reactor was rinsed with deionized water (5.0 mL) and then transferred to the polymerization reactor again using the peristaltic pump;

[0148] 6) The mixture was kept at 82° C. for 2 hours and then cooled to room temperature. The pH of the mixture was adjusted to about 7 with aqueous ammonia to obtain a comparative acrylic resin.

[0149] The monomer conversion rate during the preparation of the comparative acrylic resin in this comparative example was tested. The test results showed that the monomer conversion rate in this comparative example was 89.90%, which is relatively low. After the reaction is completed, a large amount of raw monomer remains in the reaction system without participating in polymerization. Generally speaking, a low monomer conversion rate indicates problems such as low product quality, waste of resources, low reaction efficiency, negative impacts on the human body and the environment, and poor economic benefits.

[0150] Combining the monomer conversion rates of Examples 1-3 and Comparative Example 1, it can be seen that the modified nanosol can effectively improve the monomer conversion rate when used to prepare propylene resin.

[0151] Figure 11 This is a photo of the comparative acrylic resin prepared in this comparative example. Figure 11 It can be seen that the comparative acrylic resin prepared in this comparative example is in the form of an emulsion.

[0152] After testing, the solid content of the comparative acrylic resin prepared in this comparative example is 38.76%. Combining the analysis of actual examples 1-3 and comparative example 1, it can be seen that the actual solid content of comparative example 1 is quite different from the theoretical solid content. This further illustrates that when the modified nanosol is not added during the preparation of the acrylic resin, a large amount of acrylic monomer does not participate in the reaction, which will cause unstable product performance and waste of resources.

[0153] The prepared comparative acrylic resin was coated on a substrate with a wet film thickness of 100±10 μm. The coated film was first dried and cured at room temperature for 72 hours and then placed in a 60°C oven for 10 days to form a film. The performance of the comparative acrylic resin after film formation was then tested. The test results are shown in Table 1.

[0154] Comparative Example 2

[0155] The difference between this comparative example and Example 3 is that, in the preparation process of the acrylic resin, the monomer pre-emulsion is not delivered by a peristaltic pump, but is delivered by titration with a constant pressure burette. Specifically, the preparation process of the comparative acrylic resin is as follows:

[0156] 1. Preparation of modified nano-SiO2 sol:

[0157] a) adding anhydrous ethanol (112.5 mL), deionized water (112.5 mL) and aqueous ammonia (13.5 mL) to a reaction vessel and stirring at room temperature (the room temperature in the present invention is 25° C.) for 15 minutes to obtain a mixed solution;

[0158] b) heating the mixture to 60° C., adding ethyl orthosilicate (13.5 mL) dissolved in anhydrous ethanol (150.0 mL) to the mixed solution obtained in step a), and stirring the mixture for 2 hours (stirring speed: 400 rpm / min) to obtain a nano-SiO sol;

[0159] c) raising the temperature to 91° C., adding silane coupling agent KH570 (7.2 mL) dissolved in ethanol aqueous solution (47.2 mL, anhydrous ethanol:deionized water volume ratio of 3:1) to the reaction vessel of the nano-SiO sol obtained in step b), and stirring the reaction for 5 hours to obtain a modified nano-SiO sol, which was recorded as KH570@SiO sol.

[0160] 2. Preparation of modified nano-TiO2 sol:

[0161] ① Add butyl titanate (50.0 mL) and anhydrous ethanol (50.0 mL) into a reaction vessel and stir at room temperature to mix them uniformly to obtain a mixed solution A;

[0162] ② Mix anhydrous ethanol (25.0 mL), deionized water (25.0 mL) and hydrochloric acid (hydrochloric acid concentration is 37.5%, 1.6 mL) at room temperature to obtain mixed solution B. The obtained mixed solution B can be placed in a constant pressure separatory funnel for later use;

[0163] ③ Add the mixed solution B dropwise to the mixed solution A at room temperature, and complete the addition within 15 minutes. After the addition is complete, stir the mixture at room temperature for 0.5 hours (stirring speed is 400 rpm / min) to obtain a nano-TiO2 sol;

[0164] ④ Add silane coupling agent (7.2 mL) dropwise to the reaction vessel of the nano-TiO2 sol obtained in step ③. After the addition is complete, the reactant is stirred and reacted at room temperature for 24 hours, and then heated to 91°C for 1.5 hours to obtain a modified nano-TiO2 sol, which is recorded as KH570@TiO2 sol.

[0165] 3. Comparative preparation of acrylic resin:

[0166] 1) OP-10 (1.0 g), sodium lauryl sulfate (1.0 g), deionized water (100.0 mL), KH570@TiO2 sol (6.62 mL), and KH570@SiO2 sol (11.53 mL) (the molar ratio of KH570@TiO2 to KH570@SiO2 was 3:1) were added to a pre-emulsification reactor and stirred at 28°C (400 rpm / min) to mix uniformly to obtain a mixed solution;

[0167] 2) Butyl acrylate (BA, 50.00 g), methyl methacrylate (MMA, 22.32 g), hydroxypropyl acrylate (HPA, 15.84 g), and glycidyl methacrylate (GMA, 7.26 g) were added to the mixed solution obtained in step 1), and pre-emulsified at 28° C. for 30 minutes (stirring speed was 12000 rpm / min during the pre-emulsification process) to obtain a monomer pre-emulsion solution for later use;

[0168] 3) Dissolve an initiator (potassium persulfate, 0.25 g) in deionized water (150.0 mL) to prepare an initiator solution;

[0169] 4) adding the initiator solution obtained in step 3) to the polymerization reactor, then slowly adding 2 / 3 of the monomer pre-emulsion obtained in step 2) to the polymerization reactor, and then slowly heating the reactor to 85° C. at a heating rate of 5° C. / min. During this process, the shear rate was 400 rpm / min;

[0170] 5) After the temperature stabilized at 85° C., the remaining monomer pre-emulsion was added dropwise to the polymerization reactor using a constant pressure burette. During the addition process, the dropwise addition rate was 1 drop / s and the shear rate was 400 rpm / min. After the monomer pre-emulsion was delivered, the pre-emulsion reactor was rinsed with deionized water (5.0 mL) and the mixture was added dropwise to the polymerization reactor again using a constant pressure burette.

[0171] 6) The mixture was kept at 82° C. for 2 hours and then cooled to room temperature. The pH of the mixture was adjusted to about 7 with aqueous ammonia to obtain a comparative acrylic resin.

[0172] The monomer conversion rate during the preparation of the comparative acrylic resin in this comparative example was tested (the testing method for the monomer conversion rate was specifically described). The test results showed that in this comparative example, the monomer conversion rate was 86.08%, which was lower than that in Example 3. This shows that the present invention uses a peristaltic pump instead of a constant pressure burette to transport the pre-emulsion, and at the same time extends the silicone tube of the peristaltic pump below the liquid surface, which can effectively improve the monomer conversion rate.

[0173] The prepared comparative acrylic resin was coated on a substrate with a wet film thickness of 100±10 μm. The coated film was first dried and cured at room temperature for 72 hours and then placed in a 60°C oven for 10 days to form a film. The performance of the comparative acrylic resin after film formation was then tested. The test results are shown in Table 1.

[0174] Comparative Example 3

[0175] Preparation of SiO2 nanoparticles by hydrothermal method:

[0176] Measure 100 mL of water glass (modulus: 2.25, content 29.99%), dilute it with 400 mL of deionized water, then add 1.6 g of stearic acid, and stir with a glass rod to prepare the reaction solution; prepare a sulfuric acid solution with a volume ratio of 10%; slowly add the prepared sulfuric acid solution to the reaction solution, and adjust the pH to 10-11; transfer the solution to an autoclave, heat it to 180°C, and react at a constant temperature for 4 hours to terminate the reaction; cool it, and centrifuge and wash it until the washing liquid contains no sulfate, thereby obtaining SiO2 nanoparticles.

[0177] Figure 12 The XRD pattern of the hydrothermal SiO2 nanoparticles prepared in this comparative example is as follows: Figure 12 It can be seen that the SiO2 synthesized by the hydrothermal method has a lot of impurity peaks, indicating that a lot of impurities are produced in the process of forming SiO2 particles, and high-purity SiO2 nanoparticles cannot be directly formed.

[0178] Figure 13 The SEM image of the hydrothermal SiO2 nanoparticles prepared in this comparative example is as follows: Figure 13 It can be seen that the agglomeration effect of silica prepared by the hydrothermal method is relatively serious, and the nano-silica prepared is not completely regular small spheres. Most of them are spherical, and a small part is randomly dispersed in the shape of pears.

[0179] Figure 14 The actual photo of the hydrothermal SiO2 nanoparticles prepared in this comparative example is shown in FIG. Figure 14 It can be seen that the SiO2 nanoparticles prepared by the hydrothermal method are milky white agar-like, and their consistency is significantly higher than that of the nano-silica sol prepared by the sol method in Example 1.

[0180] Combining the SiO2 nanoparticles prepared by the sol-gel method in Example 1 and the SiO2 nanoparticles obtained by the hydrothermal method in Comparative Example 3, it can be seen that the SiO2 nanoparticles prepared by the hydrothermal method are not suitable for subsequent graft copolymerization with acrylic monomers to obtain modified acrylic resins. If the SiO2 prepared by the hydrothermal method is subsequently graft copolymerized with acrylic monomers to obtain modified acrylic resins, the following problems will arise: 1) Increased difficulty in reaction control, as the gel-like SiO2 may not be easily evenly dispersed in the reaction system, affecting the uniformity and controllability of the reaction; 2) Impact on monomer conversion rate, as the structure of the SiO2 gel may subsequently interact with the monomer or polymer in unexpected ways, resulting in reduced reaction efficiency or the occurrence of side reactions; 3) Reduced reaction rate, as the SiO2 gel may interfere with the conversion of acrylic monomers, reducing the reaction rate or causing incomplete reactions; 4) Impact on the performance of the acrylic resin, as the gel-like SiO2 may have an adverse effect on the physical properties of the final product, such as increasing the viscosity of the product or reducing the purity of the product.

[0181] Comparative Example 4

[0182] Preparation of acrylic resin by grafting method:

[0183] 1) OP-10 (1.0 g), sodium lauryl sulfate (1.0 g), deionized water (100.0 mL), and KH570@SiO2 sol (58.0 mL, prepared by the method of Example 1) were added to a reactor and stirred at 28° C. (at a stirring speed of 450 rpm / min) to mix uniformly to obtain a mixed solution;

[0184] 2) Add D012 acrylic emulsion (95.42 g) to the mixed solution and pre-emulsify at 28° C. for 30 minutes (stirring speed during pre-emulsification is 12000 rpm / min) to obtain a monomer pre-emulsion for later use;

[0185] 3) Dissolve an initiator (potassium persulfate, 0.25 g) in deionized water (150.0 mL) to prepare an initiator solution;

[0186] 4) adding the initiator solution obtained in step 3) to the polymerization reactor, and then slowly adding 2 / 3 of the monomer pre-emulsion obtained in step 2) to the polymerization reactor, and then slowly heating the reactor to 82° C. at a heating rate of 5° C. / min. During this process, the shear rate was 450 rpm / min;

[0187] 5) After the temperature stabilized at 82° C., the remaining monomer pre-emulsion was added to the polymerization reactor using a peristaltic pump at a shear rate of 450 rpm / min. After the monomer pre-emulsion was delivered, the pre-emulsion reactor was rinsed with deionized water (5.0 mL) and then added to the polymerization reactor again using the peristaltic pump;

[0188] 6) The mixture was kept at 82° C. for 2 hours and then cooled to room temperature. The pH of the mixture was adjusted to about 7 with aqueous ammonia to obtain a comparative acrylic resin.

[0189] Figure 15 This is a photo of the comparative acrylic resin prepared by the grafting method in this comparative example. Figure 15 It can be seen that the comparative acrylic resin prepared by the grafting method is in a latex-like state as a whole, indicating that the modified nanosol is used to directly graft the acrylic resin, the grafting rate is low, and sedimentation or aggregation problems are prone to occur, resulting in the product being in a latex-like state, and an emulsion-like acrylic resin cannot be obtained as in the example.

[0190] Table 1 Performance test data of acrylic resins prepared in Examples 1-3 and comparative acrylic resins prepared in Comparative Examples 1, 2, and 4

[0191]

[0192]

[0193] As shown in Table 1, compared with the unmodified comparative acrylic resin under the same conditions, the anti-corrosion water-based acrylic resin obtained by modifying the nanosol in the present invention has excellent pencil hardness, adhesion, impact resistance, salt spray resistance and high elongation at break, and has excellent comprehensive performance, and all items meet national standards.

[0194] Moreover, compared with the anti-corrosion water-based acrylic resin modified by a single modified nano-SiO2 sol or modified nano-TiO2 sol, the anti-corrosion water-based acrylic resin modified by a combination of modified nano-SiO2 sol and modified nano-TiO2 sol has more excellent salt spray resistance and better anti-corrosion performance; compared with the traditional semi-continuous seed emulsion polymerization method and the acrylic resin prepared by directly grafting and modifying the acrylic resin with modified nano-sol, the anti-corrosion water-based acrylic resin prepared by the semi-continuous seed emulsion polymerization method in the embodiment of the present invention has more excellent salt spray resistance and high elongation at break, and better anti-corrosion performance and mechanical properties.

[0195] Finally, it should be pointed out that the above are only some preferred embodiments of the present invention and should not be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above contents of the present invention fall within the scope of protection of the present invention.

Claims

1. An anticorrosive water-based acrylic resin, characterized in that: It has the following composition and ratio: Butyl acrylate: 12.41wt%~14.12wt%; Methyl methacrylate: 5.54wt%~6.30wt%; Hydroxypropyl acrylate: 3.93wt%~4.47wt%; Glycidyl methacrylate: 1.8wt%~2.05wt%; Modified nanosol: 0.48wt%~14.28wt%; Emulsifier: 0.37wt%~0.42wt%; Initiator: 0.06wt%~0.07wt%; Ammonia: 0.01wt%~0.05wt%; Deionized water: 63.29wt%~72.01wt%; The sum of the proportions of the above components is 100%; The modified nanosol is a composition of modified nano-SiO2 sol and modified nano-TiO2 sol, and the modified nanosol is prepared by firstly using a sol method to prepare an inorganic nanosol, and then modifying the inorganic nanosol with a silane coupling agent KH570; The preparation of the anticorrosive water-based acrylic resin comprises the following steps: 1) Adding a proportion of emulsifier, a portion of deionized water and a proportion of modified nanosol into a pre-emulsification reactor, stirring at 28-30° C. to mix them uniformly to obtain a mixed solution; 2) adding a proportion of butyl acrylate, methyl methacrylate, hydroxypropyl acrylate, and glycidyl methacrylate to the mixed solution obtained in step 1), and pre-emulsifying at 28-30° C. for 0.5-1 hour to obtain a monomer pre-emulsion; 3) dissolving a proportion of the initiator in a portion of the deionized water to obtain an initiator solution; 4) adding the initiator solution obtained in step 3) into the polymerization reactor, and then slowly adding 2 / 3 of the monomer pre-emulsion obtained in step 2) into the polymerization reactor, and then heating to 82-85° C.; 5) After the temperature stabilizes at 82-85°C, use a peristaltic pump to deliver the remaining monomer pre-emulsion to the polymerization reactor. During the delivery process, the peristaltic pump silicone tube in the polymerization reactor is always below the liquid level. After the monomer pre-emulsion is delivered, rinse the pre-emulsification reactor with the remaining amount of deionized water and deliver it to the polymerization reactor again through the peristaltic pump; 6) The reaction was maintained at 82-85°C for 2 hours, and then cooled to room temperature. The pH of the resulting mixture was adjusted to 7-8 with aqueous ammonia to obtain an anti-corrosion water-based acrylic resin.

2. The anticorrosive water-based acrylic resin according to claim 1, characterized in that: The emulsifier is a combination of an anionic emulsifier and a nonionic emulsifier, the anionic emulsifier is selected from any one of disodium dodecyl diphenyl ether sulfonate, sodium dodecylbenzene sulfonate, and sodium lauryl sulfate, and the nonionic emulsifier is selected from any one of alkylphenol polyoxyethylene ether, Tween 20, and Tween 80, wherein the mass ratio of the anionic emulsifier to the nonionic emulsifier is 2:

1.

3. The anticorrosive water-based acrylic resin according to claim 1, characterized in that: The initiator is any one of persulfate, hydrogen peroxide, dibenzoyl peroxide and tert-butyl peroxide hydroxide, and the persulfate is any one of sodium persulfate, potassium persulfate and ammonium persulfate.

4. The anticorrosive water-based acrylic resin according to claim 1, characterized in that: The preparation of the modified nano-SiO2 sol comprises the following operations: a) adding anhydrous ethanol, deionized water, and aqueous ammonia to a reaction vessel and stirring at room temperature for 10 to 15 minutes to obtain a mixed solution; b) heating the mixture to 55-65° C., adding anhydrous ethanol containing ethyl orthosilicate to the mixed solution obtained in step a), stirring and reacting for 2-3 hours to obtain a nano-SiO sol; c) raising the temperature to 90-95° C., adding an ethanol aqueous solution containing a silane coupling agent to the reaction vessel of the nano-SiO 2 sol obtained in step b), and stirring the reaction for 5-6 hours to obtain a modified nano-SiO 2 sol.

5. The anticorrosive water-based acrylic resin according to claim 4, characterized in that: The volume ratio of ethyl orthosilicate in step b) to ammonia water in step a) is 1:1; the molar ratio of silane coupling agent in step c) to ethyl orthosilicate in step b) is 0.5:

1.

6. The anticorrosive water-based acrylic resin according to claim 1, characterized in that The preparation of the modified nano-TiO2 sol includes the following operations: ① Add butyl titanate and anhydrous ethanol into a reaction vessel and stir at room temperature to mix them evenly to obtain a mixed solution A; ② Mix anhydrous ethanol, deionized water and hydrochloric acid at room temperature to obtain mixed solution B; ③ Add mixed solution B dropwise to mixed solution A at room temperature. After the addition is complete, stir and react at room temperature for 0.5 to 1 hour to obtain nano-TiO2 sol; ④ Add silane coupling agent dropwise to the reaction vessel of the nano-TiO2 sol obtained in step ③. After the addition is completed, the resulting reactant is stirred and reacted at room temperature for 23 to 25 hours, and then heated to 90 to 95°C for 1 to 2 hours to obtain a modified nano-TiO2 sol.

7. The anticorrosive water-based acrylic resin according to claim 6, characterized in that: The molar ratio of the silane coupling agent in step ④ to the butyl titanate in step ① is 0.5:1.

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