Environment-friendly high-transmittance water-based paint and preparation method thereof

Abstract

The invention relates to the technical field of water-based paint, and discloses environment-friendly high-light-transmittance water-based paint and a preparation method thereof.The preparation method comprises the steps of construction of a basic anti-fog system, construction of a photochromic intelligent response system, construction of a salt-fog-resistant protection system and multi-stage emulsification and curing. Through the synergistic effect of the three functional systems, stable photochromic performance and antifogging effect are kept in a high-salt-fog environment, the light transmittance reaches 95% or above, the service life is four times or above that of a common formula, meanwhile, the VOC content is lower than 50 g / L, the environmental protection requirement is met, and the technical problem that a traditional antifogging coating is unstable in performance in a severe environment is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of waterborne paints, and more specifically, it relates to an environmentally friendly high-transparency waterborne paint and a preparation method thereof. Background Art

[0002] With the wide application of transparent materials in various fields, the anti-fog coating technology has developed rapidly. However, the existing anti-fog transparent coatings have the following technical problems: Traditional anti-fog coatings are prone to fogging when the temperature and humidity change, affecting the light transmittance; The anti-fog effect is unstable under different lighting conditions and lacks environmental adaptability; In high-salt fog environments such as coastal and marine areas, the functional components of the coating are easily interfered by salt ions, resulting in a sharp decline in performance; The coating has insufficient durability and a short service life in harsh environments; Existing improvement schemes usually sacrifice the light transmittance of the coating or increase the emission of environmentally harmful substances. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides an environmentally friendly high-transparency waterborne paint and a preparation method thereof.

[0004] An environmentally friendly high-transparency waterborne paint, comprising: a basic anti-fog system, a photochromic intelligent response system, and a salt fog resistance protection system; Wherein the basic anti-fog system comprises a waterborne acrylic resin, a surfactant composite system, an amphiphilic functional group modifier, and a surface energy gradient regulator; the photochromic intelligent response system comprises a photochromic material, an intramolecular hydrogen bond self-assembly aid, and a biomimetic adhesion protein complex; the salt fog resistance protection system comprises a salt ion capture and encapsulation material, a salt-induced self-healing molecular network component, and a bio-inspired penetration regulator.

[0005] Preferably: The surfactant composite system is composed of a non-ionic surfactant and an amphoteric surfactant mixed in a weight ratio of 3:1 - 5:1, and contains hydrophilic functional groups.

[0006] Preferably: The photochromic material is a spiropyran, spirooxazine, and / or diarylethene compound, which can undergo reversible structural changes under specific lighting conditions.

[0007] Preferably: The salt ion capture and encapsulation material is a cyclodextrin derivative, which has the ability to selectively capture and encapsulate salt ions, and its structure is β-cyclodextrin or γ-cyclodextrin modified with hydroxypropyl or hydroxyethyl.

[0008] Preferably: The salt-induced self-healing molecular network component is composed of an ion-responsive polymer, and contains functional groups that can form coordination bonds with salt ions, including carboxyl, sulfonic acid, or imine groups.

[0009] A preparation method of an environmentally friendly high-transparency waterborne paint, comprising the following steps: Step 1: A step of constructing a basic anti-fogging system; Step 2: A step of constructing a photochromic intelligent response system; Step 3: A step of constructing a salt spray resistant protection system; Step 4: A step of multi-stage emulsification and curing.

[0010] Preferably: The step of constructing the basic anti-fogging system includes: mixing 30-35 parts by weight of waterborne acrylic resin with 15-20 parts by weight of deionized water, stirring at 40-45 °C to form a homogeneous dispersion system, and then adding 2-4 parts by weight of a surfactant composite system containing hydrophilic functional groups, 1-2 parts by weight of an amphiphilic functional group modifier, and 0.5-1 part by weight of a surface energy gradient regulator.

[0011] Preferably: The step of constructing the photochromic intelligent response system includes: sequentially adding 1-3 parts by weight of a photochromic material, 1-2 parts by weight of an intramolecular hydrogen bond self-assembly aid, and 3-5 parts by weight of a biomimetic adhesion protein complex to the basic anti-fogging system.

[0012] Preferably: The step of constructing the salt spray resistant protection system includes: adding 2-4 parts by weight of a salt ion capture and encapsulation material, 1-3 parts by weight of a salt-induced self-healing molecular network component, and 1-2 parts by weight of a bio-inspired penetration regulator to the mixed system of the basic anti-fogging system and the photochromic intelligent response system.

[0013] Preferably: The step of multi-stage emulsification and curing includes: After fully mixing the three functional systems, performing treatment by a multi-stage emulsification process, including: Primary emulsification: Mechanically stirring at a speed of 600-800 rpm for 30-40 minutes; Secondary emulsification: Adding high-speed shear emulsification, 15000-20000 rpm, and treating for 10-15 minutes; Tertiary emulsification: Ultrasonic treatment, with a power of 300-500 W, and intermittent treatment for 5-8 minutes; Adding 1-2 parts by weight of a curing agent and 0.5-1 part by weight of a film-forming aid to the emulsification system, and continuing to stir for 10-15 minutes to obtain a uniform coating system; Coating curing: After the coating is applied, pre-drying at room temperature (20-25 °C) for 2-4 hours, and then curing at 40-50 °C for 4-6 hours.

[0014] The beneficial effects of the present invention are as follows: The environmentally friendly high-transparency waterborne paint and its preparation method provided by the present invention achieve the following technical effects through the synergistic effect of three functional systems: The coating maintains a high light transmittance of over 95% under various environmental conditions. Among them, the average light transmittance in the visible light band of 400 - 700 nm reaches 97%, meeting the requirements of high light transmittance applications. After 1000 hours of accelerated testing in a 5% salt spray environment, the light transmittance decreases by no more than 2%, which is higher than that of existing anti-fog coatings.

[0015] The coating exhibits good anti-fog performance under different lighting conditions. Through the synergistic effect of the photochromic system and the basic anti-fog system, it can adjust the surface hydrophilicity according to the environmental light intensity to achieve environmental adaptive anti-fog. Under the condition of changing light intensity, the contact angle of the coating surface changes in the range of 15° - 45°, ensuring effective prevention of fog condensation in different environments.

[0016] Through the salt ion capture encapsulation method and the salt-induced self-healing molecular network, the coating exhibits the following performance indicators in a 5% salt spray environment: the retention rate of the photochromic function > 85% (after 1000 hours of testing); the retention rate of the anti-fog effect > 90% (after 1000 hours of testing); the service life is more than 4 times that of ordinary formulations; the interfacial adhesion in the salt environment decreases by no more than 15%.

[0017] The salt-induced self-healing molecular network endows the coating with the ability of self-repairing micro-damage. In the salt spray environment, microscopic scratches (<100μm) can self-repair within 24 - 48 hours, and the functional recovery rate of the repaired area reaches over 80%, extending the service life of the coating.

[0018] The present invention uses water as the dispersion medium, with a VOC content lower than 50 g / L, lower than the national standard limit, and does not contain harmful heavy metals and biotoxic substances, meeting the environmental protection requirements and solving the technical problem of unstable performance of traditional anti-fog coatings in harsh environments such as high salt spray. At the same time, the coating preparation process has low energy consumption and is completed below 50℃ throughout the process, saving energy consumption.

[0019] In summary, by organically combining the basic anti-fog system, the photochromic intelligent response system, and the salt spray resistant protection system, the present invention realizes the synergistic effect of the three functions, solves the technical problem of unstable performance of traditional anti-fog coatings in harsh environments such as high salt spray, and has clear technological progressiveness. Description of the Drawings

[0020] Figure 1 are the test results of the light transmittance of the photochromic anti-fog environmentally friendly high-transparency waterborne paint with salt spray resistance in the present invention under different conditions; Figure 2 are the test results of the contact angle of the coating surface and the anti-fog performance under different lighting conditions in the present invention.

[0021] Figure 3It is the change in the anti-fog performance of the coating after the salt spray environment cycle test in the present invention (under the illumination condition of 1000 lux). Figure 4 It is the test result of the coating function retention rate in the salt spray environment of the present invention; Figure 5 It is the test result of the sample service life prediction in the present invention; Figure 6 It is the coating function degradation rate (% / 100 hours) in the 5% salt spray environment of the present invention Figure 7 It is the self-healing rate (%) of the coating micro-scratches under different environments in the present invention; Figure 8 It is the function recovery rate of the self-healing area in the salt spray environment (after 48 hours) of the present invention; Figure 9 It is the analysis result of the coating micro-region structure before and after self-healing (the change in the relative intensity of the FTIR spectrum peaks) in the present invention Figure 10 It is the test result of the coating environmental protection performance in the present invention; Figure 11 It is the test of the coating preparation energy consumption and environmental friendliness in the present invention; Figure 12 It is the assessment of the environmental impact of the coating life cycle in the present invention. Detailed implementation manners

[0022] Now, the subject matter described herein will be discussed with reference to exemplary embodiments. It should be understood that discussing these embodiments is only to enable those skilled in the art to better understand and thus implement the subject matter described herein. Without departing from the protection scope of the content of this specification, changes can be made to the functions and arrangements of the elements discussed. Each example can omit, substitute, or add various processes or components as needed. Additionally, the features described in some examples can also be combined in other examples.

[0023] In at least one embodiment of the present invention, a preparation method of an environment-friendly high-transparency waterborne paint is disclosed, including the following steps: 1. Step of constructing the basic anti-fog system Mix 30 or 32 or 35 parts by weight of aqueous acrylic resin (32 parts by weight are selected in this embodiment) with 15 or 18 or 20 parts by weight of deionized water (18 parts by weight are selected in this embodiment), stir at 40 or 43 or 45 °C (43 °C is selected in this embodiment) to form a uniform dispersion system, and then add the following components: 2 - 4 parts by weight of a surfactant composite system containing hydrophilic functional groups, the surfactant composite system being formed by mixing a non - ionic surfactant and an amphoteric surfactant in a weight ratio of 3:1 or 4:1 or 5:1 (4:1 is selected in this example); 1 or 1.5 or 2 parts by weight of an amphiphilic functional group modifier (1.5 parts by weight is selected in this example), the modifier containing a hydrophobic end and a hydrophilic end, where the hydrophilic end contains hydrophilic groups such as hydroxyl, carboxyl, and / or hydroxymethyl, and the hydrophobic end contains a long carbon chain or a cyclic structure; 0.5 or 0.7 or 1 part by weight of a surface energy gradient regulator (0.7 parts by weight is selected in this example), which is used to form a gradient distribution structure from hydrophobic to hydrophilic on the coating surface.

[0024] The key to constructing the basic anti - fog system lies in the configuration of amphiphilic functional groups and the surface energy gradient distribution. By controlling the surface energy difference, water droplets can spread evenly on the surface instead of condensing into fog droplets. During the curing process of the coating, the hydrophilic end of this amphiphilic functional group is oriented towards the coating surface, forming a stable hydrophilic layer.

[0025] 2. Steps for constructing a photochromic intelligent response system In the above - mentioned basic anti - fog system, the following components are added in sequence: 1 or 2 or 3 parts by weight of a photochromic material (2 parts by weight is selected in this example), the photochromic material being a spiropyran - type, spirooxazine - type, and / or diarylethene - type compound, which can undergo reversible structural changes under irradiation in a specified wavelength band of ultraviolet or visible light; 1 or 1.5 or 2 parts by weight of an intramolecular hydrogen - bond self - assembly assistant (1.5 parts by weight is selected in this example), which can promote the formation of an ordered arrangement structure between hydrophilic functional groups and photochromic molecules through hydrogen - bond interaction; 3 or 4 or 5 parts by weight of a biomimetic adhesion protein complex (4 parts by weight is selected in this example), the complex being composed of mussel foot - thread protein derivatives, containing dopamine groups or L - dopa derivatives, and having excellent interfacial adhesion performance and hydrolysis resistance.

[0026] In this step, the photochromic material and hydrophilic functional groups form an ordered arrangement structure through intramolecular hydrogen bonds, enabling the photochromic material to synchronously adjust the surface hydrophilicity and hydrophobicity when undergoing conformational changes, forming an anti - fog effect in response to light. At the same time, the biomimetic adhesion protein complex forms an interfacial structure with adhesion force in a wet environment in the coating, solving the problem of the decreased adhesion of traditional anti - fog coatings in a wet environment.

[0027] 3. Steps for constructing a salt - fog resistance protection system In the above - mentioned system, the following components are further added to construct a salt - fog resistance protection system: 2, 3, or 4 parts by weight of salt ion-capturing encapsulating material (3 parts by weight are selected in this example). The material is a cyclodextrin derivative, which has the ability to selectively capture and encapsulate salt ions. Its structural feature is β-cyclodextrin or γ-cyclodextrin modified by hydroxypropyl or hydroxyethyl, and has a cavity structure suitable for the size of salt ions. 1, 2, or 3 parts by weight of salt-induced self-healing molecular network component (2 parts by weight are selected in this example). The component is composed of a polymer with ionic responsiveness, which can form a reversible crosslinked network in the presence of salt ions. Its characteristic is that it contains functional groups that can form coordination bonds with salt ions, such as carboxyl group, sulfonic acid group, or imine group, etc. 1, 1.5, or 2 parts by weight of bio-inspired osmotic regulator (1.5 parts by weight are selected in this example). The regulator mimics the osmotic regulation function of salt-tolerant plants such as mangroves, and is composed of betaine compounds, proline compounds, and / or polyol compounds, which can maintain the water balance of the coating in a high-salt environment.

[0028] The core function of this step is to develop a salt ion-capturing encapsulation method and a salt-induced self-healing molecular network, which transform salt ions from an interfering factor into a function-enhancing factor. The salt ion-capturing encapsulating material blocks the adverse interaction between salt ions and functional molecules by wrapping the salt ions; while the salt-induced self-healing molecular network uses salt ions as crosslinking points to enhance the stability of the molecular network and form a self-repair function after coating damage.

[0029] 4. Multi-stage emulsification and curing step After fully mixing the above three functional systems, a multi-stage emulsification process is used for treatment, including: Primary emulsification: Mechanically stir at a speed of 600, 700, or 800 rpm (700 rpm is selected in this example) for 30, 35, or 40 minutes (35 minutes is selected in this example); Secondary emulsification: Add high-speed shear emulsification at 15000, 18000, or 20000 rpm (18000 rpm is selected in this example) and process for 10, 12, or 15 minutes (12 minutes is selected in this example); Tertiary emulsification: Ultrasonic treatment, with a power of 300, 400, or 500 W (400 W is selected in this example), and intermittent treatment for 5, 7, or 8 minutes (7 minutes is selected in this example); Add 1, 1.5, or 2 parts by weight (1.5 parts by weight are selected in this example) of curing agent and 0.5, 0.7, or 1 part by weight (1.5 parts by weight are selected in this example) of film-forming auxiliary agent to the emulsification system, and continue stirring for 10, 12, or 15 minutes (35 minutes is selected in this example) to obtain a uniform coating system; Coating curing: After the coating is applied, it is pre-dried at room temperature (20 - 25 °C) for 2 or 3 or 4 hours (3 hours are selected in this example), and then cured at 40 or 45 or 50 °C (45 °C is selected in this example) for 4 or 5 or 6 hours (5 hours are selected in this example), and finally completely cured.

[0030] Through different levels of emulsification treatment, the multi-stage emulsification process enables the uniform dispersion and directional distribution of each functional component at the nanoscale, forming a reasonable spatial structure of the three major functional systems in the coating and giving full play to the synergistic effect. At the same time, according to the above curing process, each functional component can be directionally arranged during the curing process of the coating, forming a functional gradient distribution from the substrate to the surface.

[0031] In at least one embodiment of the present invention, an environmentally friendly high-transparency waterborne paint is disclosed, which is prepared by the above preparation method.

[0032] Experiments and Tests To verify the technical effects of the present invention, the following experiments and tests were carried out to prove the various technical effects in Embodiment 1.

[0033] I. High-transparency performance test 1. Test method The test uses a UV-Vis Spectrophotometer to measure the light transmittance of the coating in the visible light range (400 - 700 nm).

[0034] 2. Test steps: 1) Prepare the coating according to the above method, apply it on an optical-grade glass substrate with a thickness of 2 mm, and control the dry film thickness at 25 ± 2 μm; 2) Set the reference sample as the uncoated optical glass of the same specification; 3) Use the spectrophotometer to measure the light transmittance at each point every 20 nm in the 400 - 700 nm band; 4) Place the coated sample in an artificial salt spray environment with a concentration of 5% (in accordance with ISO 9227 standard), and take it out for light transmittance test at 0 hours, 500 hours, and 1000 hours respectively; 5) Calculate the average light transmittance in the visible light band.

[0035] 3. Test results See Figure 1 The test results of the light transmittance of the photochromic anti-fog environmentally friendly high-transparency waterborne paint resistant to salt spray corrosion under different conditions.

[0036] Note: The comparative sample is a commercially available ordinary anti-fog coating, which is tested under the same conditions.

[0037] From Figure 1It can be seen that the average light transmittance of the coating of the present invention reaches 97.3% in the initial state. After 1000 hours of salt spray environment test, the average light transmittance still remains at 95.9%, and the decrease in light transmittance is only 1.4%. Under the same conditions, the light transmittance of the comparative sample drops from the initial state (similar to the sample of the present invention) to 89.6%, with a decrease of 7.7%. The results show that the coating of the present invention maintains excellent light transmittance performance in the salt spray environment.

[0038] II. Intelligent anti-fog effect test 1. Test method The test combines a contact angle measuring instrument and an artificial simulated atomization environment to evaluate the anti-fog performance of the coating under different lighting conditions.

[0039] 2. Test steps: 1) Prepare the coating according to the method of Embodiment 1, apply it on a 5 cm × 5 cm optical glass substrate, and control the dry film thickness at 25 ± 2 μm; 2) Prepare four groups of samples and conduct tests under different lighting conditions respectively: Group A: Dark environment (0 lux) - Group B: Weak indoor light environment (500 lux); Group C: Standard indoor lighting (1000 lux); Group D: Bright outdoor environment (simulating 10000 lux); 3) Use a contact angle measuring instrument to measure the water droplet contact angle of each group of samples after 1 hour of equilibrium under the corresponding lighting conditions; 4) In an artificial simulated atomization chamber (temperature 25°C, relative humidity 95%), place each group of samples under the corresponding lighting conditions and observe the fogging time and degree; 5) Use image analysis software to calculate the percentage of the fogging area (the percentage of the fog-covered area in the total area).

[0040] 3. Test results See Figure 2 Test results of the contact angle and anti-fog performance of the coating surface under different lighting conditions.

[0041] Note: The comparative sample is a commercially available ordinary anti-fog coating without photochromic properties.

[0042] See Figure 3 Change of the anti-fog performance of the coating after salt spray environment cycle test (using 1000 lux lighting condition).

[0043] From Figure 2 and Figure 3It can be seen that the coating of the present invention exhibits obvious light-responsive anti-fog properties: the higher the light intensity, the smaller the contact angle (the more hydrophilic the surface), and the better the anti-fog effect. Under strong light conditions of 10,000 lux, the coating hardly fogs up. Even after a salt spray environment test lasting up to 1,000 hours, the coating still maintains good anti-fog performance. After 30 minutes, the fogging area is only 33.2%, while that of the comparative sample is as high as 92.4% under the same conditions. This proves the intelligent anti-fog effect of the coating of the present invention and its stability in a salt spray environment.

[0044] III. Salt spray resistance performance test 1. Test method The test was carried out using a standard salt spray test chamber for accelerated aging testing to evaluate the performance stability of the coating in a high salt spray environment.

[0045] 2. Test steps: 1) Prepare the coating according to the method of Embodiment 1 and coat it on optical glass and aluminum alloy plates respectively, with the dry film thickness controlled at 25 ± 2 μm; 2) Place the samples in a salt spray test chamber (in accordance with ISO 9227 standard), with a salt spray concentration of 5%, a temperature of 35 ± 2 °C, and a relative humidity of 98 ± 2%; 3) Take out the samples at 0 hours, 200 hours, 500 hours, and 1,000 hours respectively for the following tests: Photochromic function test: Measure the optical absorption difference of the samples before and after ultraviolet light irradiation using a spectrophotometer; Anti-fog effect test: Test the fogging time and area in a standard atomization environment; Interface adhesion test: Evaluate the adhesion of the coating to the substrate using the cross-cut test method (ISO 2409 standard); 4) Conduct the same tests on a commercially available ordinary anti-fog coating (comparative sample 1) and a commercially available weather-resistant water-based paint (comparative sample 2) simultaneously.

[0046] 3. Test results See Figure 4 Test results of the function retention rate of the coating in a salt spray environment; Note: The calculation method of the retention rate is (performance value after testing / initial performance value) × 100%.

[0047] See Figure 5 Test results of the service life prediction of the samples; Note: The service life prediction is calculated according to the corresponding relationship between accelerated aging and actual exposure in accordance with ISO 16474 standard.

[0048] See Figure 6 The decline rate of the coating function (% / 100 hours) in a 5% salt spray environment.

[0049] From Figures 4 - 6 It can be seen that the coating of the present invention exhibits excellent salt spray resistance in a 5% concentration salt spray environment. After 1000 hours of salt spray environment testing, the retention rate of the photochromic function is 86.5%, the retention rate of the anti-fogging effect is 91.2%, and the retention rate of the interfacial adhesion is 86.8%, which is much higher than that of the comparative sample. According to the correlation analysis between the accelerated aging test and the actual use, the estimated service life of the coating of the present invention is 4.2 years, which is 4.2 times that of Comparative Sample 1 (ordinary anti-fogging coating). The functional degradation rate data shows that the performance degradation rate of the coating of the present invention in the salt spray environment is significantly lower than that of the comparative sample, demonstrating its durability and stability in a high salt spray environment.

[0050] IV. Self-healing ability test 1. Test method The test adopts a combination of the micro-scratch method and microscopic observation to evaluate the self-healing ability of the coating in the salt spray environment.

[0051] 2. Test steps: 1) Prepare the coating according to the method of Embodiment 1, apply it on the optical glass substrate, and control the dry film thickness at 25 ± 2 μm; 2) Use an automatic scratch tester to create micro-scratches with different depths on the coating surface: Group A: Slight scratches on the surface, with a depth of about 10% of the coating thickness (2 - 3 μm); Group B: Medium scratches, with a depth of about 50% of the coating thickness (12 - 15 μm); Group C: Severe scratches, with a depth of about 80% of the coating thickness (20 - 22 μm); 3) Use a high-resolution digital microscope to take pictures of the initial scratch state; 4) Divide the samples into three groups and place them in different environments: The first group: Ordinary indoor environment (temperature 25°C, relative humidity 50%); The second group: High-humidity environment (temperature 25°C, relative humidity 95%); The third group: 5% concentration salt spray environment (according to ISO 9227 standard); 5) Take out the samples at 0 hour, 12 hours, 24 hours, 48 hours, and 72 hours respectively, and use the same microscope to take pictures of the scratch state at the same position; 6) Use image analysis software to measure the changes in the scratch width and depth, and calculate the self-healing rate; 7) Conduct functional tests on the repaired area, including light transmittance, anti-fogging performance, and photochromic function.

[0052] 3. Test results See Figure 7 Self-healing rate of coating micro-scratches (%) under different environments; Note: The self - repair rate calculation method is (initial scratch area - current scratch area) / initial scratch area × 100%.

[0053] See Figure 8 : The functional recovery rate of the self - repair area in the salt - fog environment (after 48 hours); See Figure 9 : The analysis results of the micro - area structure of the coating before and after self - repair (the relative intensity change of the FTIR spectral peak).

[0054] From Figures 7 - 9 It can be seen that the coating of the present invention shows significant self - repair ability in the salt - fog environment. Especially for minor scratches (depth < 3μm), the self - repair rate is as high as 95.2% after 48 hours, which is much higher than the repair effect in the ordinary environment. For medium scratches, the self - repair rate is 83.7% after 48 hours, also showing good repair ability. In terms of functional recovery, the light transmittance, anti - fog function and photochromic function recovery rates in the minor scratch area are all above 90%. The micro - area structure analysis shows that the self - repair of the coating in the salt - fog environment is closely related to the newly formed cross - link points induced by salt ions. The relative intensity of the salt - ion cross - link points even exceeds the initial state after self - repair, proving that the coating of the present invention can transform salt ions from a destructive factor into a factor enhancing the self - repair function.

[0055] V. Environmental protection performance test 1. Test method The test uses the standard environmental protection index evaluation method to evaluate the environmental protection performance of the coating, such as the VOC content, heavy metal content, preparation energy consumption and biological toxicity of the coating.

[0056] 2. Test steps: VOC content test: The test is carried out in accordance with the national standard GB / T 23986 - 2009 "Determination of volatile organic compounds (VOC) content in coatings"; A gas chromatography - mass spectrometry (GC - MS) is used to detect the types and contents of volatile organic compounds in the coating; Heavy metal content test: An inductively coupled plasma mass spectrometry (ICP - MS) is used to detect the heavy metal content in the coating; Harmful heavy metals such as lead, cadmium, mercury and hexavalent chromium are detected with emphasis; Energy consumption test: Record the energy consumption in the whole process of coating preparation, including the energy consumption in processes such as stirring, emulsification and curing; Calculate the energy consumption per unit area according to the same coating area; Biological toxicity test: A zebrafish embryo acute toxicity experiment (FET) is used to evaluate the toxicity of the coating to aquatic organisms; The germination rate of plant seeds was used to test and evaluate the impact of the coating on plants; The cytotoxicity of the coating to mammalian cells was evaluated by cell viability experiment (MTT method).

[0057] 3. Test results See Figure 10 Test results of the environmental protection performance of the coating; See Figure 11 Energy consumption and environmental friendliness test for coating preparation; See Figure 12 Environmental impact assessment of the coating life cycle; Note: The relative values are compared with the environmental impact of the coating of the present invention taken as 100.

[0058] From Figures 10 - 12 It can be seen that the coating of the present invention has obvious advantages in terms of environmental protection performance. The VOC content is 42.5 g / L, far lower than the national standard limit value (80 g / L) and the comparative sample. The detection results of heavy metal contents are all lower than the detection limit, meeting strict environmental protection requirements. The highest temperature during the coating preparation process is only 45 °C, and the energy consumption is 0.32 kWh / m², significantly lower than the energy consumption of the comparative sample during preparation. The biotoxicity test shows that the coating of the present invention has almost no toxicity to zebrafish embryos, plant seeds and mammalian cells. The EC50 of the FET test exceeds 1000 mg / L, indicating its extremely low aquatic biological toxicity. The results of the environmental impact assessment of the life cycle show that, compared with the comparative sample, the coating of the present invention has significant environmental friendliness advantages in aspects such as global warming potential, acidification potential, and eutrophication potential.

[0059] Experimental summary Through the above five aspects of experiments and tests, the technical effects of the light - induced color - changing anti - fog environmental - friendly high - light - transmittance water - based paint with salt - fog corrosion resistance provided by the present invention were systematically verified. The experimental results show that: High light - transmittance performance: The average transmittance of the coating of the present invention in the visible light band (400 - 700 nm) reaches 97.3%. After 1000 - hour salt - fog environment test, the transmittance remains above 95.9%, and the decrease is only 1.4%, which is significantly better than the existing anti - fog coatings.

[0060] Intelligent anti - fog effect: The coating shows significant light - responsive anti - fog characteristics. Under the condition of higher light intensity, the contact angle is smaller and the anti - fog effect is better. Even after 1000 - hour salt - fog environment test, the coating can still maintain good anti - fog performance. The fogging area after 30 minutes is only 33.2%.

[0061] Salt spray resistance performance: After 1000 hours of salt spray environment test, the retention rate of the photochromic function is 86.5%, the retention rate of the anti-fog effect is 91.2%, and the retention rate of the interfacial adhesion is 86.8%, all of which are much higher than those of the comparative samples. According to the accelerated aging test prediction, the service life of the coating of the present invention is 4.2 years, which is 4.2 times that of the ordinary anti-fog coating.

[0062] Self-healing ability: The coating shows significant self-healing characteristics in the salt spray environment. For slight scratches, the self-healing rate is as high as 95.2% after 48 hours; the 48-hour self-healing rate for medium scratches is 83.7%. Microstructure analysis proves that the present invention has successfully transformed salt ions from a damaging factor into a factor enhancing the self-healing function.

[0063] Environmental protection performance: The VOC content of the coating is 42.5 g / L, which is much lower than the national standard limit and the comparative samples, and the heavy metal content is lower than the detection limit. The energy consumption during the preparation process is low, and it shows extremely low toxicity to aquatic organisms, plants, and mammalian cells. The life cycle environmental impact assessment shows that the coating of the present invention has significant environmental friendly advantages.

[0064] The above experimental results comprehensively verify all the performance indicators described in the technical effect part of the present invention, and prove that the triple-functional synergistic structure formed by the organic combination of the basic anti-fog system, the photochromic intelligent response system, and the salt spray resistance protection system of the present invention has successfully solved the technical problem of unstable performance of traditional anti-fog coatings in harsh environments such as high salt spray, and has obvious technological progressiveness.

[0065] The embodiments of the present invention have been described above, but the embodiments are not limited to the above specific implementation manners. The above specific implementation manners are only illustrative and not restrictive. Under the inspiration of this embodiment, those of ordinary skill in the art can also make more equivalent embodiments in various forms, all of which fall within the protection scope of this embodiment.

Claims

1. An environmentally friendly high light transmittance water-based paint, characterized in that: Including basic anti-fog system, photochromic intelligent response system and salt spray resistance protection system; The basic anti-fog system comprises a water-based acrylic resin, a surfactant composite system, an amphiphilic functional group modifier and a surface energy gradient regulator; the photochromic intelligent response system comprises a photochromic material, an intramolecular hydrogen bond self-assembly aid and a biomimetic adhesion protein complex; and the salt spray resistant protection system comprises a salt ion capture packaging material, a salt-induced self-healing molecular network component and a bio-inspired osmotic regulator.

2. The environmentally friendly high light transmittance water-based paint according to claim 1, characterized in that: The surfactant composite system is formed by mixing a nonionic surfactant and an amphoteric surfactant in a weight ratio of 3:1-5:1, and contains a hydrophilic functional group.

3. The environmentally friendly high light transmittance water-based paint according to claim 1, characterized in that: The photochromic material is a spiropyran, spirooxazine and / or diarylethene compound, which can undergo reversible structural changes under specific light conditions.

4. The environmentally friendly high light transmittance water-based paint according to claim 1, characterized in that: The salt ion capturing and encapsulating material is a cyclodextrin derivative, which has the ability to selectively capture and encapsulate salt ions, and its structure is beta-cyclodextrin or gamma-cyclodextrin modified by hydroxypropyl or hydroxyethyl.

5. The environmentally friendly high light transmittance water-based paint according to claim 1, characterized in that: The salt-induced self-healing molecular network component is composed of a polymer with ion responsiveness and contains functional groups that can form coordination bonds with salt ions, including carboxyl groups, sulfonic acid groups or imine groups.

6. A method for preparing an environmentally friendly high-transmittance water-based paint according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Basic anti-fog system construction steps; Step 2: Construction steps of photochromic intelligent response system; Step 3: Salt spray resistant protection system construction steps; Step 4: Multi-stage emulsification and solidification steps.

7. The preparation method according to claim 6, characterized in that: The basic anti-fog system construction steps include: mixing 30-35 parts by weight of a water-based acrylic resin with 15-20 parts by weight of deionized water, stirring at 40-45° C. to form a uniformly dispersed system, and then adding 2-4 parts by weight of a surfactant composite system containing a hydrophilic functional group, 1-2 parts by weight of an amphiphilic functional group modifier, and 0.5-1 part by weight of a surface energy gradient regulator.

8. The preparation method according to claim 6, characterized in that: The construction steps of the photochromic intelligent response system include: adding 1-3 parts by weight of photochromic material, 1-2 parts by weight of intramolecular hydrogen bond self-assembly aid and 3-5 parts by weight of bionic adhesion protein complex into the basic anti-fog system in sequence.

9. The preparation method according to claim 6, characterized in that: The steps of constructing the salt fog resistant protection system include: adding 2-4 parts by weight of salt ion capture packaging material, 1-3 parts by weight of salt-induced self-healing molecular network components and 1-2 parts by weight of bio-inspired osmotic regulator into a mixed system of a basic anti-fog system and a photochromic intelligent response system.

10. The preparation method according to claim 6, characterized in that: The multi-stage emulsification and solidification steps include: After the three functional systems are fully mixed, they are processed using a multi-stage emulsification process, including: Primary emulsification: mechanical stirring at 600-800 rpm for 30-40 minutes; Secondary emulsification: add high-speed shear emulsification, 15000-20000rpm, process for 10-15 minutes; Level 3 emulsification: ultrasonic treatment, power 300-500W, intermittent treatment for 5-8 minutes; Add 1-2 parts by weight of curing agent and 0.5-1 parts by weight of film-forming aid to the emulsified system, and continue stirring for 10-15 minutes to obtain a uniform coating system; Paint curing: After the paint is applied, pre-dry it at room temperature (20-25℃) for 2-4 hours, and then cure it at 40-50℃ for 4-6 hours.

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