A sealing agent that does not cover passivation color and its preparation method

Abstract

This invention proposes a sealing agent that does not obscure passivation color and its preparation method, belonging to the field of zinc plating and zinc alloy post-treatment technology. The method involves synthesizing a stable sol-gel polymer and adding it to water. After stirring until homogeneous, sodium molybdate and vanadium oxysulfate are added separately. After stirring to dissolve, ethylene acrylate phosphate copolymer, a wetting surfactant, and a bactericide are added and stirred until homogeneous to obtain the sealing agent that does not obscure passivation color. This sealing agent can form a thin nano-coating on the passivated metal surface without obscuring the passivation color, and it provides good uniformity of the sealed workpiece appearance, making it particularly suitable for barrel plating. Furthermore, utilizing the characteristics of a stable sol-gel polymer, the sealing agent can be infinitely diluted with water and remains stable, exhibiting low VOCs and environmental friendliness, and the film layer is water-resistant.

Description

Technical Field

[0001] This invention belongs to the field of zinc plating and zinc alloy post-treatment technology, specifically relating to a sealant that does not cover passivation color and its preparation method. Background Technology

[0002] Zinc plating and zinc alloy plating are widely used as anti-corrosion coatings for steel plates and steel components. Post-plating passivation treatment is then employed to further enhance the corrosion resistance of the coating, meeting customer requirements for corrosion resistance. Common passivating agents include blue-white passivation, colored passivation, black passivation, and military green passivation. Zinc / zinc alloy coatings treated with different passivating agents exhibit different appearance colors. To further improve the corrosion resistance of the passivated coating and meet certain fingerprint resistance and colorfastness requirements, a sealing treatment is necessary after passivation.

[0003] Currently, commonly used sealants on the market have a good masking effect on passivation colors, meaning that the sealed workpiece appears to have the original color of galvanized or zinc alloy. However, some customers require that while improving fingerprint resistance and corrosion resistance, the original passivated appearance of the workpiece should also be retained after sealing. Most existing sealants achieve their protective effect on the plated parts by curing a film layer on the metal surface, which will have a masking effect on the passivation color. For the need for sealants that do not mask passivation colors, there are already relevant sealant products on the market, but they do not achieve a completely non-masking effect. Even when the workpiece is treated with a low concentration of sealing working solution, the appearance color is still uneven after drying. At the same time, no patent literature has been found to report on sealants that do not mask passivation colors. Summary of the Invention

[0004] This invention addresses the problem in existing technologies where sealants, by curing a film on the metal surface to protect the plated part from passivation color, can have a masking effect. It provides a sealant that does not mask the passivation color and its preparation method. By preparing a stable sol-gel composition that can be infinitely diluted with water as the main film-forming component of the sealant, the sealed substrate exhibits certain fingerprint resistance and colorfastness while meeting the requirement of not masking the passivation color. Furthermore, by introducing a composite organic-inorganic corrosion inhibitor to enhance salt spray resistance, the corrosion resistance of the passivated substrate is further improved.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0006] A sealing agent that does not mask passivation color comprises 10-20 parts of a stable sol-gel polymer, 0.1-0.5 parts of sodium molybdate, 0.5-1 parts of vanadium oxysulfate, 0.1-0.3 parts of ethylene acrylate phosphate copolymer, 0.1-0.4 parts of a wetting surfactant, 0.05-0.1 parts of a bactericide, and 80-90 parts of water.

[0007] Preferably, the specific synthesis steps of the stable sol-gel polymer are as follows: an inorganic acid is added to pure water as a catalyst, and a certain amount of organometallic salt is added as a crosslinking agent; then a hydrophilic silane coupling agent is added, and the reaction is carried out at a temperature of 50 ℃-70 ℃ for 0.5 h-1 h; then an acidic silica sol with a solid content of more than 20% is added, and the reaction is carried out at a temperature of 70-90 ℃ for 3 h-4 h; after cooling, the stable sol-gel polymer is obtained.

[0008] Preferably, the inorganic acid catalyst is any one or more of sulfuric acid, nitric acid, and sulfuric acid; the amount of inorganic acid added is 0.05‰-0.15‰ of the mass of the sol-gel polymer; halogen-containing inorganic acids, such as hydrochloric acid, are not selected as they easily corrode the substrate; organic acids that easily undergo esterification reactions in the system, such as acetic acid, are not selected, and organic acids catalyze reactions slowly in this synthesis system; nitric acid is preferred as the acidic catalyst.

[0009] As a preferred embodiment, the sealing agent that does not cover the passivation color according to claim 2 is characterized in that the organometallic salt is one or more of aluminum isopropoxide, aluminum triacetylacetonate, aluminum triacetylacetonate, titanium acetylacetonate, and zirconium n-propoxide; the amount of the organometallic salt added is 0.4%-1.0% of the mass of the sol-gel polymer; such organometallic salts play a crosslinking role, improving the hardness of the film layer after the sol-gel is cured and reducing the brittleness of the film layer.

[0010] Preferably, the hydrophilic silane coupling agent is any one or more of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-(2,3-epoxypropoxy)propyltriethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, and 3-(methacryloyloxy)propyltriethoxysilane; the amount of the hydrophilic silane coupling agent added is 20%-25% of the mass of the sol-gel polymer.

[0011] Preferably, the acidic silica sol with a solid content greater than 20% is a transparent gel-like aqueous solution; the silica content of the acidic silica sol with a solid content greater than 20% is 20%-30%, the pH value is 2-5, and the particle size range is 5nm-20nm; the amount of acidic silica sol with a solid content greater than 20% added is 25%-65% of the mass of the sol-gel polymer; this type of silane coupling agent contains hydrophilic functional groups, has good water solubility, and can remain stable after catalytic polymerization under acidic conditions and can be diluted with water; controlling the mass ratio of the acidic silica sol solid mass to the silane coupling agent within the range of 0.2-0.6 helps to extend the stable storage time of the system.

[0012] A method for preparing a non-obscuring passivation color blocking agent is as follows: a stable sol-gel polymer is added to water and stirred evenly, followed by the addition of sodium molybdate and vanadium oxysulfate; after stirring to dissolve, ethylene acrylate phosphate copolymer, wetting surfactant, and bactericide are added and stirred evenly to obtain the non-obscuring passivation color blocking agent.

[0013] Preferably, the ethylene acrylate phosphate copolymer is a copolymer of polyvinyl phosphate and polyvinyl phosphate esters with methacrylic acid or hydroxyethyl methacrylate, or similar copolymers; the amount of the ethylene acrylate phosphate copolymer added is 1‰-4‰ of the mass of the sealant; this copolymer can combine a passivation film layer and a sealing layer to help improve the corrosion resistance of the treated workpiece.

[0014] Preferably, the wetting surfactant is a nonionic surfactant; the amount of the wetting surfactant added is 1‰-4‰ of the mass of the sealing agent; the wetting surfactant is a nonionic surfactant with no specific structural requirements, and its main function is to reduce the surface tension of the system and improve the wetting performance of the sealing agent.

[0015] Preferably, the bactericide is a broad-spectrum isothiazolinone bactericide; the amount of bactericide added is 0.5‰-1‰ of the mass of the blocking agent; the broad-spectrum isothiazolinone bactericide is one or a combination of two of the following: 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, and 5-chloro-2-methyl-4-isothiazolin-3-one.

[0016] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0017] 1. The present invention discloses a non-obscuring passivation color sealing agent and its preparation method. One of its raw materials, a stable sol-gel polymer, has the following advantages in synthesis: it is completed in a one-pot process, making operation simple; no other alcohols are introduced as co-solvents or other auxiliary inhibitory solvents, resulting in low VOCs and environmental friendliness; the obtained sol-gel composition can be infinitely diluted with water and remains stable for more than six months in the diluted state, thus achieving the sealing agent of the present invention's stability after infinite dilution with water, low VOCs, environmental friendliness, and water resistance of the film layer; the copolymer can be cured at 80-100℃, and the cured film layer exhibits excellent water resistance and scratch resistance; it overcomes the problems of silane-like sol-gel oligomers requiring high-temperature curing and having poor water resistance.

[0018] 2. The sealant of the present invention can form a thin nano-coating on the passivated metal surface without obscuring the passivation color, and the sealed workpiece has good uniformity of appearance, making it particularly suitable for barrel plating; in addition, the sealant of the present invention can further improve the passivation film's resistance to neutral salt spray by 2 to 3 times. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a diagram showing the sealing effect of the sealant without color coverage in Example 2;

[0021] Figure 2 This is a diagram illustrating the effect of passivation treatment on a workpiece subjected to neutral salt spray for 72 hours after sealing with an unmasked passivation sealant, as shown in Example 2.

[0022] Figure 3 This is a diagram illustrating the effect of a workpiece sealed with an unmasked passivation sealant in Example 2, followed by passivation treatment and further sealing treatment, after 72 hours of resistance to neutral salt spray.

[0023] Figure 4 This is a diagram illustrating the effect of passivation treatment for 200 hours after sealing the workpiece with an unmasked passivation sealant in Example 2.

[0024] Figure 5 This is a diagram illustrating the effect of a workpiece sealed with an unmasked passivation sealant in Example 2, followed by passivation treatment and further sealing treatment to withstand 200 hours of neutral salt spray.

[0025] Figure 6 The graph shows the corrosion polarization comparison after blue-white passivation treatment and further sealing. Detailed Implementation

[0026] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0027] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0028] like Figures 1-6 As shown, a sealing agent that does not cover passivation color comprises 10-20 parts of a stable sol-gel polymer, 0.1-0.5 parts of sodium molybdate, 0.5-1 parts of vanadium oxysulfate, 0.1-0.3 parts of ethylene acrylate phosphate copolymer, 0.1-0.4 parts of a wetting surfactant, 0.05-0.1 parts of a bactericide, and 80-90 parts of water;

[0029] The specific steps for preparing the stable sol-gel polymer contained in the blocking agent are as follows:

[0030] The first stabilized sol-gel polymer: 0.02 g of concentrated nitric acid was added to 27.4 g of pure water as a catalyst, and 0.6 g of aluminum acetylacetonate was added as a crosslinking agent. After stirring evenly, 23 g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane was added in small batches over 10 min. The mixture was heated to 60 ℃ and reacted for 30 min until the mixture became transparent. Then, 49 g of acidic silica sol with a solid content greater than 20% was added, and the mixture was heated to 80 ℃ and reacted for 3-4 h. After cooling, the stabilized sol-gel polymer was obtained.

[0031] The second stabilized sol-gel polymer: Add 0.02 g of concentrated nitric acid to 27.4 g of pure water as a catalyst. Add 23 g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane in small batches over 10 min. Heat to 60 ℃ and react for 10-20 min until the mixture becomes transparent. Then add 0.6 g of aluminum acetylacetonate as a crosslinking agent and react at 60 ℃ for 30 min until the mixture becomes transparent. Finally, add 49 g of acidic silica sol with a solid content greater than 20% and react at 80 ℃ for 3-4 h. Cool to obtain the stabilized sol-gel polymer.

[0032] The third type of stabilized sol-gel polymer: Add 0.02 g of concentrated nitric acid as a catalyst to 38 g of pure water, add 0.6 g of aluminum acetylacetonate as a crosslinking agent, stir evenly, and then add 25 g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane in small batches over 10 min. Heat to 60 ℃ and react for 30 min until the mixture becomes transparent. Then add 36 g of acidic silica sol with a solid content greater than 20%, and heat to 80 ℃ and react for 3-4 h. Cool to obtain the stabilized sol-gel polymer.

[0033] Basic performance tests were performed on the first, second, and third stabilized sol-gel polymers, including:

[0034] Appearance: Visual inspection is used to check whether the polymer is colorless and transparent.

[0035] Water dilution test: Dilute the sol-gel polymer with pure water at a mass fraction of 0.1% and observe whether any precipitation is formed. Place the diluted solution in a 50 ℃ oven for 30 days and observe whether any precipitation is formed. If the diluted solution is normal, it indicates that the sol-gel polymer can be stably maintained after dilution with water.

[0036] Sol-gel polymer stability test: According to the national standard GB / T 6753.3-1986, the sol-gel polymer is placed in a 50 ℃ oven for 30 days and then observed to see if the polymer gels. If the polymer does not gel, it means that the polymer can be stored in the natural environment for 6-12 months.

[0037] Water resistance test of the film layer: The polymer was diluted with pure water at a mass fraction of 10%. After the workpiece was galvanized and passivated with blue and white galvanizing, it was immersed in the diluted polymer and sealed for 20 seconds. Then it was placed in an 80 ℃ oven for curing for 20 minutes. After the workpiece cooled, 1-2 drops of water were dripped onto the surface. After 1 minute, the film layer at the water droplet area was gently wiped with a non-woven cloth. The film layer was observed to see if it was easily wiped off, exposing the passivation color. If the film layer was wiped off, it indicated that the polymer had poor water resistance after curing.

[0038] The basic performance test results of the first, second, and third stabilized sol-gel polymers are shown in Table 1.

[0039] Table 1. Test results of basic properties of the first to third stabilized sol-gel polymers.

[0040]

[0041] The results showed that the order of addition of aluminum acetylacetonate affected the appearance of the sol-gel polymer; later addition easily caused the polymer to yellow. The mass ratio of acidic silica sol solids to silane coupling agent was key to the water resistance of the cured film; when the ratio was <0.3, the water resistance of the cured film deteriorated. Based on the data, the first stable sol-gel polymer was preferred as one of the components of the non-masking passivation color-sealing agent.

[0042] A method for preparing a sealing agent that does not obscure passivation color, the specific steps of which are as follows:

[0043] Example 1: 10 g of the first sol-gel polymer mentioned above was added to 88.8 g of water and stirred evenly. Then, 0.3 g of sodium molybdate and 0.6 g of vanadium oxysulfate were added and stirred until dissolved. Then, 0.2 g of ethylene acrylate phosphate copolymer, 0.1 g of wetting surfactant and 0.05 g of bactericide were added and stirred evenly to obtain a sealing agent that does not cover the passivation color.

[0044] Example 2: 15 g of the first sol-gel polymer was added to 83.8 g of water and stirred evenly. Then, 0.3 g of sodium molybdate and 0.6 g of vanadium oxysulfate were added and stirred until dissolved. Then, 0.2 g of ethylene acrylate phosphate copolymer, 0.1 g of wetting surfactant and 0.05 g of bactericide were added and stirred evenly to obtain a sealing agent that does not cover the passivation color.

[0045] In Example 3, 20 g of the first sol-gel polymer was added to 78.8 g of water and stirred until homogeneous. Then, 0.3 g of sodium molybdate and 0.6 g of vanadium oxysulfate were added and stirred until dissolved. Then, 0.2 g of ethylene acrylate phosphate copolymer, 0.1 g of wetting surfactant, and 0.05 g of bactericide were added and stirred until homogeneous to obtain a sealing agent that does not cover the passivation color.

[0046] Performance tests were conducted on the non-masking passivation color sealants from Examples 1 to 3 above:

[0047] The workpiece substrate used in this application for performance testing includes various metals and their alloys, such as iron, nickel, copper, and aluminum. Conventional methods are used to galvanize and alloy the substrate. Examples of galvanizing include alkaline zinc or acid zinc, and examples of zinc alloys include zinc-iron alloys, zinc-nickel alloys, zinc-cobalt alloys, and tin-zinc alloys. The thickness of the galvanized and alloyed plating can be arbitrary, but is preferably 5 μm or more.

[0048] For the passivation process before sealing, this application can use zinc plating and zinc alloy blue-white passivation or colored passivation, preferably alkaline zinc blue-white passivation. In this test, the passivation treatment before the sealing agent non-coverage effect test of Examples 1 to 3 of this application adopted alkaline zinc plating on tinplate sheet, with a zinc plating thickness of 7 μm-9 μm, and adopted the 922P trivalent chromium blue-white passivation process of Dexi Chemical Co., Ltd. The original solution was diluted with pure water at a mass ratio of 4% of the original solution, the pH value was 2.0-2.5, and the passivation was carried out at a temperature of 20 ℃-35 ℃ for 35 s-40 s to complete the blue-white passivation treatment process before non-coverage sealing.

[0049] The specific tests are as follows:

[0050] 1. Test of passivation effect without masking

[0051] In the sealing process, the sealant stock solutions from Examples 1 to 3 are diluted with pure water at a mass ratio of 15% to obtain the sealant working solution. The workpiece treated according to the above passivation process is immersed in the sealant working solution for 20-30 seconds, then removed and cured in an 80℃ oven for 10-20 minutes. The color difference value ΔE before and after sealing is measured using an X-rite SP60 colorimeter to determine the color change before and after sealing. When ΔE is in the range of 0.5 to 1.5, the color difference is small, and the human eye can perceive a slight color change. The color difference value generated before and after sealing with the non-masking passivation sealant within this range can be judged as qualified. The color changes slightly but still maintains a uniform blue-white appearance, and has a certain degree of fingerprint resistance, meeting customer requirements. When ΔE is in the range of 1.5 to 3.0, the color difference is large, and the human eye can perceive a significant color change. The color difference value generated before and after sealing within this range is judged as unqualified. The color difference values ​​ΔE before and after the sealing agent treatment in Examples 1 to 3 are shown in Table 2. Based on the color difference values, the sealing agents in Examples 1 and 5 meet the requirements of non-occlusive passivation color.

[0052] Table 2. Test results of unmasked passivation color and fingerprint resistance in Examples 1-3 (△E)

[0053]

[0054] 2. Fingerprint resistance test

[0055] To prevent fingerprints from remaining on the surface of components during assembly, which could affect coating adhesion and appearance quality, the surface-treated workpiece must possess a certain degree of fingerprint resistance. This patent uses white petroleum jelly to simulate human sweat in its fingerprint resistance test. A small amount of petroleum jelly is applied evenly to the sealed plate surface using a non-woven fabric. After one hour, the petroleum jelly is wiped off with a clean non-woven fabric. The color difference value ΔE is measured using an X-rite SP60 colorimeter before and after applying and wiping the petroleum jelly. ΔE < 3 indicates that the unmasked passivation color sealing film has fingerprint resistance; ΔE < 1 indicates that the unmasked passivation color sealing film has excellent fingerprint resistance. The test results are shown in Table 2. Example 3 shows the best fingerprint resistance; this indicates that the higher the sol-gel polymer content in the unmasked passivation color sealant, the better the fingerprint resistance of the film, and vice versa. Considering both performance test results, Example 2 is preferred as the optimal formulation for unmasked passivation color sealing, and its unmasked passivation color effect is as follows: Figure 1 As shown.

[0056] 3. Corrosion resistance test

[0057] The salt spray test standard (NSS) for the sealant in Example 2 was performed using the national standard GB / T2423.17-93 after blue-white passivation and sealing. The results are shown in [Figure number missing]. Figures 2-5.

[0058] Data from neutral salt spray resistance shows that the time for white rust to appear in neutral salt spray on workpieces that have only undergone passivation treatment is approximately 72 hours. However, the time for white rust to appear on workpieces that have undergone further sealing agent treatment can reach over 200 hours, meeting the requirements of most customers for highly corrosion-resistant sealing agents.

[0059] 4. Using a KOST CS series electrochemical workstation, the passivated zinc plating layer was coated with the sealing agent from Example 2 (the original solution was diluted with pure water at a mass ratio of 15%) on one side. After curing and drying at 80 ℃, its potentiodynamic scanning was measured. A three-electrode system was used: a platinum electrode as the auxiliary electrode and a saturated calomel electrode as the reference electrode. The working area was 1 square centimeter, the scanning range was between -1.5 V and -0.5 V, the scanning speed was 0.5 mV / s, and the corrosive medium was 3.5% NaCl solution. Data processing and analysis were performed using the system's built-in analysis software. The results are shown in [Figure 1]. Figure 6 ; Figure 6 The figure shows the corrosion polarization curves after blue-white passivation treatment and further sealing. The corrosion current and corrosion potential values ​​are shown in Table 3.

[0060] Table 3 Corrosion current and corrosion potential values

[0061]

[0062] Combined with Table 3 and Figure 4 It can be seen that the level of the self-corrosion potential reflects the corrosion resistance of the passivation layer or the sealing film, and characterizes the tendency of the passivation or sealing film to corrode. The more positive the corrosion potential, the less likely corrosion is to occur. The smaller the self-corrosion current in the conductive solution, the better the corrosion resistance of the protective film. The fitted data show that the sample after passivation and sealing treatment has a smaller self-corrosion current and a positive potential shift, indicating that the corrosion resistance is significantly improved compared to the film treated with passivation alone, which is consistent with the measured neutral salt spray.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a non-hiding passivating color sealer, characterized in that, The sealing agent comprises, by weight parts: 10-20 parts of stabilized sol-gel polymer, 0.1-0.5 parts of sodium molybdate, 0.5-1 part of vanadium oxysulfate, 0.1-0.3 parts of ethylene acrylate phosphate copolymer, 0.1-0.4 parts of wetting surfactant, 0.05-0.1 parts of bactericide, and 80-90 parts of water; The specific preparation method is as follows: Add a stable sol-gel polymer to water, stir evenly, and then add sodium molybdate and vanadium oxysulfate respectively; after stirring to dissolve, add ethylene acrylate phosphate copolymer, wetting surfactant and bactericide, and stir evenly to obtain a sealing agent that does not cover the passivation color. The ethylene phosphate copolymer is a copolymer of polyvinyl phosphate and polyvinyl phosphate esters with methacrylic acid or hydroxyethyl methacrylate; the amount of the ethylene phosphate copolymer added is 1‰-4‰ of the mass of the blocking agent; The specific synthesis steps of the stabilized sol-gel polymer are as follows: an inorganic acid is added to pure water as a catalyst, and a certain amount of organometallic salt is added as a crosslinking agent; then a hydrophilic silane coupling agent is added, and the reaction is carried out at 50℃-70℃ for 0.5h-1h; then an acidic silica sol with a solid content of more than 20% is added, and the reaction is carried out at 70-90℃ for 3h-4h; after cooling, the stabilized sol-gel polymer is obtained. The organometallic salt is one or more of aluminum triacetylacetonate, aluminum ethyl triacetate, and titanium triacetylacetonate; the amount of the organometallic salt added is 0.4%-1.0% of the mass of the sol-gel polymer; The amount of the hydrophilic silane coupling agent added is 20%-25% of the mass of the sol-gel polymer; The amount of acidic silica sol with a solid content greater than 20% added is 25%-65% of the mass of the sol-gel polymer; The mass ratio of acidic silica sol solids to hydrophilic silane coupling agent is controlled to be greater than 0.3 and less than 0.

6.

2. The method of claim 1, wherein the non-occulsive passivation color sealant is prepared by the steps of: The wetting surfactant is a nonionic surfactant; the amount of the wetting surfactant added is 1‰-4‰ of the mass of the sealing agent.

3. The method of claim 1, wherein the non-occulsive passivation color sealant is prepared by the steps of: The bactericide is a broad-spectrum bactericide of the isothiazolinone class; the amount of bactericide added is 0.5‰-1‰ of the mass of the sealing agent.

4. The method for preparing a non-occlusive passivating color sealant according to claim 1, characterized in that, The inorganic acid is any one or more of sulfuric acid and nitric acid; the amount of inorganic acid added is 0.05‰-0.15‰ of the mass of the sol-gel polymer.

5. The method for preparing a non-occlusive passivating color sealant according to claim 1, characterized in that, The hydrophilic silane coupling agent is any one or more of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-(2,3-epoxypropoxy)propyltriethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, and 3-(methacryloyloxy)propyltriethoxysilane.

6. The method for preparing a non-occlusive passivating color sealant according to claim 1, characterized in that, The acidic silica sol with a solid content greater than 20% is a transparent gel-like aqueous solution; the acidic silica sol with a solid content greater than 20% has a silica content of 20%-30%, a pH value of 2-5, and a particle size range of 5nm-20nm.

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