Super-hydrophobic mildew and algae resistant polymer preparation and its preparation process

Abstract

The application relates to the technical field of high polymer coating, and discloses a super-hydrophobic mildew-proof and algae-resistant high polymer preparation and a preparation process thereof. The super-hydrophobic mildew-proof and algae-resistant high polymer preparation is prepared from raw materials containing the following components in parts by weight: hydroxyl-terminated polydimethylsiloxane 100 parts, hydrophilic fumed silica 5-15 parts, methyltrimethoxysilane 3-7 parts, vinyltriisopropoxysilane 1-3 parts, diisopropoxybisacetylacetone titanium 1.0-2.0 parts, acetic acid type quaternary ammonium salt polar solution 13.2-21.39 parts, and composite anchoring powder 3.2-9.5 parts. The preparation process comprises the following steps: material heating, pressure reduction and dehydration, nitrogen filling and temperature reduction, stirring and end-capping of silane and a catalyst, and finally, solution and powder are added to perform air extraction and defoaming to obtain the super-hydrophobic mildew-proof and algae-resistant high polymer preparation. The super-hydrophobic mildew-proof and algae-resistant high polymer preparation of the application excludes halogen interference to guarantee coating curing and film forming, and utilizes acid-sensitive response to release drugs outwardly, so that long-acting protection is realized.

Description

Technical Field

[0001] This invention relates to the field of polymer coating technology, specifically to a superhydrophobic antifungal and antialgae polymer formulation and its preparation process. Background Technology

[0002] Polymer formulations are often used to create coatings for application on the surfaces of outdoor power transmission towers, switchgear, and other metal equipment. Because exposed metal is constantly exposed to the natural environment, its surface easily absorbs moisture and breeds various microorganisms. Microbial metabolic products and retained water films alter the microenvironment of the metal surface, causing degradation of the material's physicochemical properties, thus affecting the normal operation and lifespan of the equipment. To ensure equipment safety, polymer coatings need to possess corresponding environmental barrier capabilities, requiring formulations to simultaneously possess composite protective functions such as superhydrophobicity, mildew resistance, and algae resistance.

[0003] Existing protective coatings mostly use organosilicon polymers as the base film-forming material, and quaternary ammonium salt antifungal agents and halogen-containing antialgae agents are directly mixed in during the formulation stage. This conventional approach mainly relies on the antifungal and antialgae agents to naturally migrate and seep to the surface after the coating has cured, so as to contact and inhibit fungal and algal spores attached to the equipment substrate, thereby maintaining the antibacterial state of the coating's outer surface.

[0004] However, these conventional mixing methods have technical drawbacks in practical applications. On the one hand, antifungal and antialgae agents directly mixed into the coating are easily washed away by rainwater, resulting in a significantly shortened effective protection period. If the superhydrophobic properties of the formulation are simply improved to reduce surface moisture adhesion, the dense surface will, in turn, hinder the effective penetration and release of the internal agents. On the other hand, existing high-efficiency antifungal and antialgae agents generally contain halide ions. Free halogens readily compete for coordination with the titanate catalysts required for siloxane crosslinking, causing catalyst poisoning and deactivation. This directly leads to difficulties in curing the polymer formulation into a film after coating or insufficient crosslinking, ultimately affecting the stability of the entire coating structure.

[0005] Therefore, this invention proposes a superhydrophobic antifungal and antialgae polymeric formulation and its preparation process to overcome the shortcomings of the prior art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a superhydrophobic anti-mildew and anti-algae polymer formulation and its preparation process, which solves the problems of existing anti-mildew and anti-algae coatings being affected by the deactivation of crosslinking catalysts due to halogenated agents, thus affecting curing and film formation, and the effective components in the coating being easily lost with surface moisture, resulting in insufficient long-term protection.

[0007] To address the above problems, the present invention provides the following technical solution:

[0008] In a first aspect, the present invention provides a superhydrophobic antifungal and antialgae polymeric formulation, which adopts the following technical solution:

[0009] Hydroxyl-terminated polydimethylsiloxane: 100 parts; hydrophilic fumed silica: 5-15 parts; methyltrimethoxysilane: 3-7 parts; vinyltriisopropoxysilane: 1-3 parts; diisopropoxydiacetylacetonate: 1.0-2.0 parts; acetic acid-type quaternary ammonium salt polar solution: 13.2-21.39 parts; composite anchoring powder: 3.2-9.5 parts.

[0010] By adopting the above technical solution, the superhydrophobic antifungal and antialgae polymeric formulation of the present invention exhibits the following synergistic mechanisms throughout the entire cycle from formulation to later use:

[0011] For the cross-linking and curing stage of the formulation, the terminal silanol groups of the hydroxyl-terminated polydimethylsiloxane need to condense with alkoxysilanes to form a three-dimensional network under a titanium catalyst. Since the halide ions in conventional quaternary ammonium salts can compete for coordination with titanate catalysts, causing catalyst poisoning, this solution pre-prepares and introduces a halogen-free acetic acid-type quaternary ammonium salt polar solution, eliminating the interference of free halide ions and effectively maintaining the catalytic activity of diisopropoxydiacetylacetone titanium. Simultaneously, the vinyltriisopropoxysilane used in the formulation has a relatively large sterically hindered isopropoxy group, which to some extent reduces the cross-linking reaction rate of the organosilicon polymer. The extended skinning time provides sufficient space for the polar solution to migrate to the formulation surface.

[0012] As the solution containing quaternary ammonium salts gradually migrates to the surface, the long-chain quaternary ammonium salts distributed on the surface of the formulation can not only directly destroy the cell membrane of the attached bacteria to achieve early contact sterilization, but also work with the polydimethylsiloxane solidification network to construct a superhydrophobic barrier with low surface energy, reducing the residence of environmental moisture and microbial spores on the surface of metal equipment from the physical interface.

[0013] In terms of long-term protection, the composite anchoring powders dispersed within the organosilicon cross-linked network play a role in environmental response. Specifically, active zinc oxide and zinc-aluminum hydrotalcite serve as inorganic matrices, with zinc pyrithione and promethazine immobilized on their surfaces. When the formulation is exposed to a humid environment for an extended period and a small amount of microorganisms adhere, the acidic secretions produced by mold or algae metabolism lower the pH of the local microenvironment. This slightly acidic condition triggers the neutralization and degradation of the inorganic matrix within the powder, thereby releasing the antifungal and antialgae agents originally locked onto the matrix. Through this response mechanism that relies on environmental changes to trigger agent release, the unnecessary loss of agents is effectively reduced, significantly extending the overall antifungal and antialgae cycle of the formulation.

[0014] Preferably, the acetic acid-type quaternary ammonium salt polar solution is prepared by a method comprising the following steps:

[0015] A dimethyl octadecyl [3-(trimethoxysilyl)propyl]ammonium chloride methanol solution was stirred with anhydrous silver acetate powder under light-protected conditions to undergo a halide ion displacement reaction. After filtering to remove the silver chloride precipitate, an acetic acid-type quaternary ammonium salt methanol filtrate was obtained. Subsequently, dipropylene glycol dimethyl ether was added to the acetic acid-type quaternary ammonium salt methanol filtrate, and vacuum distillation was carried out under heating conditions until no methanol fraction was distilled off, thus obtaining the acetic acid-type quaternary ammonium salt polar solution.

[0016] The raw materials used to prepare the acetic acid-type quaternary ammonium salt polar solution include, by weight:

[0017] The following components are present: 5.0-10.0 parts of a 60% dimethyl octadecyl [3-(trimethoxysilyl)propyl]ammonium chloride methanol solution, 1.06-2.12 parts of anhydrous silver acetate powder, and 10.0-15.0 parts of dipropylene glycol dimethyl ether.

[0018] By employing the above technical solution, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride undergoes a displacement reaction with anhydrous silver acetate, followed by filtration to remove the generated silver chloride precipitate, thereby completely removing halogens from the system. To avoid the original methanol solvent evaporating and causing bubble defects during subsequent formulation blending and curing, dipropylene glycol dimethyl ether, which has a relatively high boiling point, is added as a solvent replacement in the process. While removing methanol by vacuum distillation, the polar characteristics of dipropylene glycol dimethyl ether not only maintain the stable dissolution state of the acetate-type quaternary ammonium salt, but also act as a carrier medium for the migration of the quaternary ammonium salt to the surface during subsequent molding.

[0019] Preferably, the composite anchoring powder is prepared by a method comprising the following steps:

[0020] Active zinc oxide, zinc aluminum hydrotalcite, zinc pyrithione, and pyrazinamide are added to a mixer and stirred and dispersed to obtain a mixed primary powder. Isopropyl trioleoyl oxytitanate is sprayed into the mixed primary powder while stirring. After high-speed mixing and discharge, a composite anchoring powder with a surface coated with titanate coupling agent is obtained.

[0021] The raw materials used to prepare the composite anchoring powder include, by weight: 1.5-3.5 parts of active zinc oxide, 0.5-1.5 parts of zinc aluminum hydrotalcite, 0.5-2.0 parts of zinc pyrithione, 0.5-2.0 parts of pyrazinamide, and 0.2-0.5 parts of isopropyltrioleyloxytitanate.

[0022] By adopting the above technical solution, the sprayed isopropyltrioleoyloxytitanate will coat the inorganic matrix and the antifungal and antialgal agent. This plays a coupling role to improve the compatibility between the inorganic powder and the organic silicone material interface and reduce the agglomeration phenomenon during blending. More importantly, this titanate coupling agent is used to firmly bind zinc pyrithione and promethazine to the surface of active zinc oxide and zinc aluminum hydrotalcite with acid-sensitive properties, thereby successfully constructing the aforementioned microenvironment response release structure.

[0023] Preferably, the hydroxyl-terminated polydimethylsiloxane has a dynamic viscosity between 2000 and 5000 mPa·s at 25°C; and the hydrophilic fumed silica has a specific surface area between 150 and 250 m² / s as measured by nitrogen adsorption. 2 Between / g.

[0024] By adopting the above technical solution, the dynamic viscosity of hydroxyl-terminated polydimethylsiloxane is controlled between 2000-5000 mPa·s. This ensures suitable flow properties of the material during blending and imparts sufficient elasticity and deformation capacity to the product after crosslinking. This is achieved by using materials with a specific surface area between 150-250 m² / s. 2 / g of hydrophilic fumed silica, due to the large number of free silanol groups on its surface, readily forms hydrogen bonds with polydimethylsiloxane segments. This not only brings the necessary thixotropy to the compound formulation process, but also directly improves the overall mechanical strength of the final molded formulation.

[0025] Secondly, the present invention provides a preparation process for a superhydrophobic antifungal and antialgae polymeric formulation, which adopts the following technical solution:

[0026] A preparation process for a superhydrophobic antifungal and antialgae polymeric agent includes the following steps:

[0027] S1. Hydroxyl-terminated polydimethylsiloxane and hydrophilic fumed silica are mixed and stirred, heated to raise the temperature of the mixture, and simultaneously vacuumed to remove moisture. After mixing, a matrix adhesive is obtained. S2. The matrix adhesive is cooled, nitrogen is introduced to restore the internal pressure of the mixing environment to normal and maintain a slight positive pressure protection, and then methyltrimethoxysilane, vinyltriisopropoxysilane and diisopropoxydiacetylacetonate titanium are added and stirred to complete cross-linking and end-capping, resulting in a capped base adhesive. S3. Acetic acid-type quaternary ammonium salt polar solution and composite anchoring powder are added to the capped base adhesive, mixed, and simultaneously vacuumed to remove air bubbles generated during the mixing process, resulting in a superhydrophobic antifungal and antialgae polymer formulation.

[0028] By adopting the above technical solution, the preparation process of the present invention plays a corresponding technical guarantee role at different operation stages. Specifically, for the initial mixing of polymer formulations, since the titanate catalysts and crosslinking silanes to be added later are significantly sensitive to water molecules, even if there is a trace amount of residual moisture in the material, it is very easy to cause premature hydrolysis of silanes and lead to the formation of local hard lumps inside the rubber compound. Therefore, in the initial mixing stage of the process, the free moisture entrained inside the polymer matrix and fillers is directly forced out by physical means of heating combined with vacuum decompression.

[0029] After the free moisture is completely removed, to ensure that the silane crosslinking agent participates in the reaction according to the preset ratio, the matrix adhesive is actively cooled in the process, and dry nitrogen gas is introduced into the environment to maintain a slight positive pressure. This anhydrous environmental protection mechanism with slight positive pressure not only cuts off the path for secondary intrusion of external moisture, but also inhibits the excessive volatilization of silane monomers at high temperatures. Introducing the crosslinking agent and titanate into the cooled material allows the terminal hydroxyl groups to be smoothly converted into active end-capping groups with structures such as isopropoxy groups, which lays a uniform network foundation for subsequent film formation and curing.

[0030] With the aforementioned uniform cross-linked network as a support, the timing of adding the anti-mold and anti-algae components becomes particularly important. By placing the blending point of the quaternary ammonium salt polar solution and the composite anchoring powder at the end of the reaction, the stage most susceptible to interference during the organosilicon cross-linking and sealing process is avoided, preventing complex components from affecting the conversion rate of silanol groups. The accompanying secondary vacuuming operation at this time can promptly remove the micro-air bubbles inevitably introduced during powder dispersion, preventing pore defects in the cured formulation and thus ensuring the compactness of the formulation in terms of physical morphology.

[0031] Preferably, in step S1, the heating raises the temperature of the mixture to 110-130°C, the mixing speed is 600-1000 rpm, and the time is 1.5-2.5 hours.

[0032] By adopting the above technical solution, the temperature of 110-130℃ combined with the high rotation speed of shearing accelerates the physical dispersion process of fumed silica in polydimethylsiloxane. More importantly, the surface of fumed silica easily adsorbs surrounding moisture through hydrogen bonds. This temperature range is sufficient to promote the desorption and escape of this bound water, fundamentally improving the dehydration efficiency in the early stage.

[0033] Preferably, in step S2, the matrix adhesive is cooled to 35-45°C, the stirring speed is 300-500 rpm, and the stirring time is 20-40 minutes.

[0034] By employing the above technical solution, the crosslinking catalyst often exhibits a rapid reaction catalytic rate, which, if left uncontrolled, can easily lead to localized explosive polymerization. Lowering the temperature and controlling it within the 35-45℃ range precisely limits the activity of diisopropoxydiacetylacetonate titanium. Simultaneously, the moderate reduction in stirring speed mitigates the self-heating phenomenon caused by mechanical shearing, thus providing the crosslinking agent molecules with sufficient time to penetrate and disperse throughout the compound, achieving a smooth and uniform end-capping process.

[0035] Preferably, in step S3, the blending temperature is controlled at 35-45℃, the rotation speed is 400-800 rpm, and the time is 0.5-1.5 hours; the vacuuming and depressurization operation controls the absolute pressure to be maintained between 0.05-0.08 MPa.

[0036] By adopting the above technical solution, considering that the quaternary ammonium salt polar solution contains some easily volatile solvent media, the temperature is maintained at a relatively low level of 35-45℃ during this stage to avoid thermal decomposition or premature volatilization of the effective anti-mold components. During the simultaneous evacuation operation, the absolute pressure is maintained between 0.05-0.08 MPa. This moderate negative pressure is just enough to extract the air bubbles generated by the mixture, without causing excessive removal of the polar solvent that originally served as a migration carrier.

[0037] This invention provides a superhydrophobic antifungal and antialgae polymeric formulation and its preparation process. It possesses the following beneficial effects:

[0038] 1. This invention crosslinks halogen-free acetic acid-type quaternary ammonium salts with polysiloxanes, avoiding catalyst poisoning caused by traditional halide ions. This ensures smooth curing of the base adhesive and the formation of a stable polymer on the surface of metal substrates such as power transmission towers and switchgear. During molding, the quaternary ammonium salt migrates to the surface, achieving contact sterilization and providing early anti-mildew effects. As long-chain alkyl groups accumulate on the surface, a superhydrophobic surface is directly constructed, effectively physically isolating the outdoor environment from microbial spores, cutting off adhesion conditions at the contact point, improving overall anti-algae performance, and blocking direct contact between moisture and biological metabolites on the metal substrate.

[0039] 2. This invention constructs an acid-sensitive composite powder of surface-anchoring agent and disperses it within a polymer formulation. It utilizes acidic substances produced by microbial metabolism to degrade the inorganic matrix, thereby promoting the release of active ingredients. This response process avoids the loss of internal agents due to external superhydrophobic properties and long-term outdoor rain erosion. While reducing ineffective losses and extending the anti-mildew cycle of the metal substrate surface, it specifically inhibits the growth and reproduction of attached microorganisms, ensuring a long-lasting anti-algae effect in the later stages of product development.

[0040] 3. This invention, by selecting silane crosslinking monomers with large steric hindrance, reduces the rate of early condensation and curing. The extended skinning time allows room for the internal solution to migrate to the surface of the polymer formulation, ensuring the superhydrophobic state of the coating after application. Combined with staged temperature control and reduced-pressure degassing processes, microporous defects within the material are eliminated. The dense crosslinked structure blocks the penetration of environmental moisture, reduces the accidental dissolution of internal anti-mold components, and maintains the formulation's anti-algae strength against physical wear, meeting the long-term protection needs of power metal equipment in complex outdoor environments. Attached Figure Description

[0041] Figure 1 This is a comparative bar chart of the test results of free chloride ion concentration and methanol residue in this invention. (a) shows the changes in the measured free chloride ion concentration in the unmodified raw material used in Comparative Example 3 and the polar solutions used in Examples 1 to 3, and (b) shows the changes in the measured methanol residue in the unmodified raw material used in Comparative Example 3 and the polar solutions used in Examples 1 to 3.

[0042] Figure 2 This is a line graph showing the cumulative release of zinc pyrithione of the present invention over time. (a) shows the cumulative release curves of the cured films of Examples 1 to 3 and Comparative Example 4 in a neutral water microenvironment with pH 7.0, and (b) shows the cumulative release curves of the cured films of Examples 1 to 3 and Comparative Example 4 in a simulated metabolic acid microenvironment with pH 4.0.

[0043] Figure 3 This is a line graph showing the dynamic change trend of the N / Si atomic ratio on the coating surface at different curing stages of the present invention. Detailed Implementation

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0046] Hydroxyl-terminated polydimethylsiloxane is a linear homopolymer with CAS number 70131-67-8. Its main chain is composed of alternating silicon-oxygen bonds, with methyl groups as side groups and hydroxyl groups at both ends of the molecule. Its dynamic viscosity at 25°C is between 2000 and 5000 mPa·s.

[0047] Fumed silica, with CAS number 112945-52-5, is hydrophilic, with free silanol groups on its particle surface. Its specific surface area, measured by nitrogen adsorption, ranges from 150 to 250 m². 2 Between / g.

[0048] The CAS number of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride is 27668-52-6, and this invention uses a methanol solution with a mass fraction of 60% of it.

[0049] The CAS number for vinyltriisopropoxysilane is 18023-33-1.

[0050] The CAS number for diisopropoxydiacetylacetonate is 17927-72-9.

[0051] The CAS number for dipropylene glycol dimethyl ether is 111109-77-4, and its boiling range is between 170 and 180°C.

[0052] The zinc oxide is active zinc oxide, with CAS number 1314-13-2.

[0053] Zinc-aluminum hydrotalcite is a commercially available, conventional inorganic layered bimetallic hydroxide with the chemical formula Zn6Al2(OH). 16 CO3·4H2O.

[0054] The CAS number for zinc pyrithione is 13463-41-7.

[0055] The CAS number for chlorpyrifos is 7287-19-6, and its melting point is determined to be 118 to 120°C.

[0056] Isopropyltrioleoyloxytitanate is a monoalkoxy type titanate coupling agent with CAS number 61417-49-0.

[0057] Preparation Example 1: This preparation example provides a method for preparing a polar solution of acetic acid-type quaternary ammonium salt, including the following steps:

[0058] Step 1: Add 7.5 parts by mass of 60% dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride methanol solution and 1.59 parts by mass of anhydrous silver acetate powder to a reaction vessel equipped with a light-proof function. Stir at 300 rpm for 5 hours at 22°C to generate silver chloride precipitate through a halide ion replacement reaction. Then remove the precipitate by filtration through a 0.22-micron pore size filter membrane to obtain acetic acid quaternary ammonium salt methanol filtrate.

[0059] Step 2: Transfer the acetic acid-type quaternary ammonium salt methanol filtrate obtained in Step 1 to a vacuum distillation vessel equipped with vacuum and condensation recovery functions. Add 12.5 parts of dipropylene glycol dimethyl ether. While stirring at 150 rpm, raise the temperature of the mixture to 62°C and reduce the absolute pressure to 0.008 MPa by vacuum distillation. Under these conditions, distill under reduced pressure for 1.5 hours until no methanol fraction is distilled off, thus obtaining an acetic acid-type quaternary ammonium salt polar solution.

[0060] Preparation Example 2: This preparation example provides a method for preparing a polar solution of acetic acid-type quaternary ammonium salt, including the following steps:

[0061] Step 1: Add 5.0 parts by mass of 60% dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride methanol solution and 1.06 parts of anhydrous silver acetate powder to a reaction vessel equipped with a light-proof function. Stir at 200 rpm for 4 hours at 20°C to generate silver chloride precipitate through a halide ion replacement reaction. Then remove the precipitate by filtration through a 0.22-micron pore size filter membrane to obtain acetic acid quaternary ammonium salt methanol filtrate.

[0062] Step 2: Transfer the acetic acid-type quaternary ammonium salt methanol filtrate obtained in Step 1 to a vacuum distillation vessel equipped with vacuum and condensation recovery functions. Add 10 parts of dipropylene glycol dimethyl ether. While stirring at 100 rpm, raise the temperature of the mixture to 60°C and reduce the pressure to 0.005 MPa. Distill under vacuum for 1 hour until no methanol fraction is distilled off, to obtain an acetic acid-type quaternary ammonium salt polar solution.

[0063] Preparation Example 3: This preparation example provides a method for preparing a polar solution of acetic acid-type quaternary ammonium salt, including the following steps:

[0064] Step 1: Add 10.0 parts by mass of 60% dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride methanol solution and 2.12 parts by mass of anhydrous silver acetate powder to a reaction vessel equipped with a light-proof function. Stir at 400 rpm for 6 hours at 25°C to generate silver chloride precipitate through a halide ion replacement reaction. Then remove the precipitate by filtration through a 0.22-micron pore size filter membrane to obtain acetic acid quaternary ammonium salt methanol filtrate.

[0065] Step 2: Transfer the acetic acid-type quaternary ammonium salt methanol filtrate obtained in Step 1 to a vacuum distillation vessel equipped with vacuum and condensation recovery functions. Add 15 parts of dipropylene glycol dimethyl ether. While stirring at 200 rpm, raise the temperature of the mixture to 65°C and reduce the pressure to 0.01 MPa. Distill under vacuum for 2 hours until no methanol fraction is distilled off, to obtain an acetic acid-type quaternary ammonium salt polar solution.

[0066] Preparation Example 4: This preparation example provides a method for preparing composite anchoring powder, including the following steps:

[0067] Step 1: Add 2.5 parts of active zinc oxide, 1.0 part of zinc aluminum hydrotalcite, 1.25 parts of zinc pyrithione and 1.25 parts of pyrimethanil to a high-speed powder mixer and stir at 400 rpm for 5 minutes at 22°C to disperse the powder and obtain a mixed primary powder.

[0068] Step 2: While maintaining the stirring state of the high-speed powder mixer, uniformly spray 0.35 parts of isopropyltrioleoyloxytitanate into the mixed primary powder obtained in Step 1, and then increase the speed of the mixer to 1000 rpm, mix at 22°C for 12 minutes, and after discharge, obtain composite anchoring powder with the surface coated by titanate coupling agent.

[0069] Preparation Example 5: This preparation example provides a method for preparing composite anchoring powder, including the following steps:

[0070] Step 1: Add 1.5 parts of active zinc oxide, 0.5 parts of zinc aluminum hydrotalcite, 0.5 parts of zinc pyrithione and 0.5 parts of pyrazinamide to a high-speed powder mixer and stir at 300 rpm for 3 minutes at 20°C to disperse the powder and obtain a mixed primary powder.

[0071] Step 2: While maintaining the stirring state of the high-speed powder mixer, uniformly spray 0.2 parts of isopropyltrioleoyloxytitanate into the mixed primary powder obtained in Step 1, and then increase the speed of the mixer to 800 rpm, mix at 20°C for 10 minutes, and after discharge, obtain composite anchoring powder with the surface coated by titanate coupling agent.

[0072] Preparation Example 6: This preparation example provides a method for preparing composite anchoring powder, including the following steps:

[0073] Step 1: Add 3.5 parts of active zinc oxide, 1.5 parts of zinc aluminum hydrotalcite, 2.0 parts of zinc pyrithione and 2.0 parts of pyrazinamide to a high-speed powder mixer and stir at 500 rpm for 7 minutes at 25°C to disperse the powder and obtain a mixed primary powder.

[0074] Step 2: While maintaining the stirring state of the high-speed powder mixer, uniformly spray 0.5 parts of isopropyltrioleoyloxytitanate into the mixed primary powder obtained in Step 1, and then increase the speed of the mixer to 1200 rpm, mix at 25°C for 15 minutes, and after discharge, obtain composite anchoring powder with the surface coated by titanate coupling agent.

[0075] Example 1: This example provides a preparation process for a superhydrophobic antifungal and antialgae polymeric formulation, including the following steps:

[0076] S1: Add 100 parts of hydroxyl-terminated polydimethylsiloxane and 10 parts of hydrophilic fumed silica to a planetary mixer with heating and cooling jackets. Turn on the jacket heating function to raise the temperature of the mixture to 120°C. Mix and stir at 800 rpm for 2 hours at this temperature. At the same time, perform vacuuming and depressurization and control the absolute pressure to maintain at 0.02 MPa to remove moisture. After mixing, the matrix adhesive is obtained.

[0077] S2: Turn on the jacketed cooling water of the planetary mixer to cool the matrix compound obtained in S1 to 40°C. Introduce high-purity dry nitrogen into the planetary mixer to restore the internal pressure to normal and maintain a slight positive pressure protection. Then add 5 parts of methyltrimethoxysilane, 2 parts of vinyltriisopropoxysilane and 1.5 parts of diisopropoxydiacetylacetonate to the matrix compound. Mix and stir at 400 rpm for 30 minutes to complete the crosslinking and end-capping of the organosilicon polymer and obtain the end-capped base compound.

[0078] S3: Add 17.29 parts of the acetic acid-type quaternary ammonium salt polar solution prepared in Preparation Example 1 and 6.35 parts of the composite anchoring powder prepared in Preparation Example 4 to the end-capping base compound obtained in S2. Mix and stir at 600 rpm for 1 hour at 40°C, while performing vacuuming and depressurization operation and controlling the absolute pressure to be maintained at 0.06 MPa to remove air bubbles generated during the blending process, and obtain a superhydrophobic antifungal and antialgae polymer formulation.

[0079] Example 2: This example provides a preparation process for a superhydrophobic antifungal and antialgae polymeric formulation, including the following steps:

[0080] S1: Add 100 parts of hydroxyl-terminated polydimethylsiloxane and 5 parts of hydrophilic fumed silica to a planetary mixer with heating and cooling jackets. Turn on the jacket heating function to raise the temperature of the mixture to 110°C. Mix and stir at 600 rpm for 1.5 hours at this temperature. At the same time, perform vacuuming and depressurization and control the absolute pressure to maintain at 0.04 MPa to remove moisture. After mixing, the matrix adhesive is obtained.

[0081] S2: Turn on the jacketed cooling water of the planetary mixer to cool the matrix compound obtained in S1 to 35°C. Introduce high-purity dry nitrogen into the planetary mixer to restore the internal pressure to normal and maintain a slight positive pressure protection. Then add 3 parts of methyltrimethoxysilane, 1 part of vinyltriisopropoxysilane and 1.0 part of diisopropoxydiacetylacetonate to the matrix compound and mix and stir at 300 rpm for 20 minutes to complete the crosslinking and end-capping of the organosilicon polymer and obtain the end-capped base compound.

[0082] S3: Add 13.2 parts of the acetic acid-type quaternary ammonium salt polar solution prepared in Preparation Example 2 and 3.2 parts of the composite anchoring powder prepared in Preparation Example 5 to the end-capping base compound obtained in S2. Mix and stir at 400 rpm for 0.5 hours at 35°C, while performing vacuuming and depressurization operation and controlling the absolute pressure to be maintained at 0.08 MPa to remove air bubbles generated during the blending process, and obtain a superhydrophobic antifungal and antialgae polymer formulation.

[0083] Example 3: This example provides a preparation process for a superhydrophobic antifungal and antialgae polymeric formulation, including the following steps:

[0084] S1: Add 100 parts of hydroxyl-terminated polydimethylsiloxane and 15 parts of hydrophilic fumed silica to a planetary mixer with heating and cooling jackets. Turn on the jacket heating function to raise the temperature of the mixture to 130°C. Mix and stir at 1000 rpm for 2.5 hours at this temperature. At the same time, perform vacuuming and depressurization and control the absolute pressure to maintain at 0.01 MPa to remove moisture. After mixing, the matrix adhesive is obtained.

[0085] S2: Turn on the jacketed cooling water of the planetary mixer to cool the matrix compound obtained in S1 to 45°C. Introduce high-purity dry nitrogen into the planetary mixer to restore the internal pressure to normal and maintain a slight positive pressure protection. Then add 7 parts of methyltrimethoxysilane, 3 parts of vinyltriisopropoxysilane and 2.0 parts of diisopropoxydiacetylacetonate to the matrix compound. Mix and stir at 500 rpm for 40 minutes to complete the crosslinking and end-capping of the organosilicon polymer and obtain the end-capped base compound.

[0086] S3: Add 21.39 parts of the acetic acid-type quaternary ammonium salt polar solution prepared in Preparation Example 3 and 9.5 parts of the composite anchoring powder prepared in Preparation Example 6 to the end-capping base compound obtained in S2. Mix and stir at 800 rpm for 1.5 hours at 45°C, while performing vacuuming and depressurization operation and controlling the absolute pressure to be maintained at 0.05 MPa to remove air bubbles generated during the blending process, and obtain a superhydrophobic antifungal and antialgae polymer formulation.

[0087] Comparative Example 1: Compared with Example 1, the difference is that the powder was not coupled and coated, i.e., step two of Preparation Example 4 was omitted, and in S3 of Example 1, 6.35 parts of the composite anchoring powder obtained from Preparation Example 4 were replaced with 6.0 parts of the mixed primary powder obtained from step one of Preparation Example 4. All other parts were the same.

[0088] Comparative Example 2: Compared with Example 1, the difference is that vinyltriisopropoxysilane was not added in S2, but was replaced with an equal mass of methyltrimethoxysilane (i.e., 7 parts of methyltrimethoxysilane were directly added to S2). All other aspects were the same.

[0089] Comparative Example 3: Compared with Example 1, the difference is that in S3, 17.29 parts of the acetic acid-type quaternary ammonium salt polar solution prepared in Preparation Example 1 were directly replaced with 7.5 parts of a 60% by mass dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride methanol solution. All other aspects are the same.

[0090] Comparative Example 4: Compared with Example 1, the difference lies in the removal of the acid-base responsive inorganic material during the preparation of the composite powder. The active zinc oxide and zinc-aluminum hydrotalcite were replaced with an equal mass of inert silica micropowder (commercially available product, purity ≥99%, average particle size D50 between 2 and 5 micrometers, a chemically inert inorganic filler powder). Specifically, in step one of the preparation of Example 4, 3.5 parts of inert silica micropowder, 1.25 parts of zinc pyrithione, and 1.25 parts of atrazine were added. All other steps were the same.

[0091] Comparative Example 5: Compared with Example 1, the difference lies in the reversed order of adding materials in S2 and S3. Specifically, in S2: after cooling to 40°C and maintaining a slight positive pressure by purging with high-purity dry nitrogen, 17.29 parts of the acetic acid-type quaternary ammonium salt polar solution prepared in Preparation Example 1 and 6.35 parts of the composite anchoring powder prepared in Preparation Example 4 were preferentially added to the matrix adhesive. The mixture was stirred at 600 rpm for 1 hour at 40°C. In S3: 5 parts of methyltrimethoxysilane, 2 parts of vinyltriisopropoxysilane, and 1.5 parts of diisopropoxydiacetylacetonate titanium were added to the above adhesive. The mixture was stirred at 400 rpm for 30 minutes, while simultaneously performing a vacuum depressurization operation to maintain the absolute pressure at 0.06 MPa. All other steps were the same.

[0092] Test Example 1:

[0093] Experimental objective: To verify the removal efficiency of the pretreatment process of this invention for halide ions that easily lead to the deactivation of crosslinking catalysts, and to confirm the complete replacement of low-boiling-point methanol by high-boiling-point solvent during vacuum distillation, thereby providing evidence from the perspective of basic physicochemical data to support the necessity of raw material modification treatment.

[0094] Experimental steps:

[0095] The unmodified dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride methanol solution directly added in Comparative Example 3 served as the control group; the acetic acid-type quaternary ammonium salt polar solution prepared in Preparation Example 1, used in Example 1, served as test group one; the acetic acid-type quaternary ammonium salt polar solution prepared in Preparation Example 2, used in Example 2, served as test group two; and the acetic acid-type quaternary ammonium salt polar solution prepared in Preparation Example 3, used in Example 3, served as test group three. 5.00 g of each of the four test solutions was accurately weighed and placed in a clean, dry beaker, and 25 mL of anhydrous ethanol was added to each to fully dissolve and dilute them for titration.

[0096] The theoretical initial free chloride ion concentration was obtained based on the molar percentage of a single chloride ion in the chemical formula of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (molecular weight 496.28), combined with the calibrated 60% effective mass fraction, and directly derived from the theoretical initial free chloride ion mass percentage in the control group through stoichiometry. Since the basic quaternary ammonium salt raw materials for test groups one through three all originated from the same batch of products, this theoretical value was also used as the calculation benchmark for subsequently evaluating the treatment effect of the precursor solution in each embodiment.

[0097] To determine the concentration of free chloride ions, 3 mL of 1 mol / L dilute nitric acid was added dropwise to each diluted sample solution for acidification to prevent interference from quaternary ammonium salt hydrolysis. Titration was performed using an automatic potentiometric titrator equipped with a silver / silver chloride composite electrode, with a 0.05 mol / L silver nitrate standard solution in the dark. The instrument recorded the volume of silver nitrate solution consumed at the endpoint of the titration with a potential abrupt change. The number of moles of silver ions consumed was converted to the number of moles of free chloride ions in the sample, and then divided by the initial mass of the 5.00 g stock solution to obtain the final measured concentration of free chloride ions (i.e., mass percentage) for each sample.

[0098] The chloride ion removal rate is calculated by subtracting the measured free chloride ion concentration of each test group from the theoretical initial free chloride ion concentration, dividing the difference by the theoretical initial free chloride ion concentration, and finally multiplying by 100% to obtain the final chloride ion removal rate of the polar solutions used in Examples 1 to 3.

[0099] The determination of methanol residue was performed using a gas chromatograph equipped with a flame ionization detector (FID). A small amount of the original test solution from each of the four groups, before dilution with anhydrous ethanol, was diluted 100-fold with chromatographic-grade acetone and injected into the injection port. The methanol peak was identified by retention time, and the peak area was obtained by automatic integration. This peak area value was then substituted into a pre-defined peak area-concentration standard curve using pure methanol standard solutions of known concentration gradients to calculate the measured methanol residue (i.e., mass percentage) in each group of sample solutions.

[0100] Experimental results (see Table 1):

[0101] Table 1: Test data on free chloride ion concentration and methanol residue of each sample

[0102] Sample source Theoretical initial free chloride ion concentration (wt%) Measured free chloride ion concentration (wt%) Chloride ion removal rate (%) Actual methanol residue (wt%) Unmodified raw materials used in Comparative Example 3 4.120 4.153 - 38.74 Polar solution used in Example 1 4.120 0.082 98.01 0.28 Polar solution used in Example 2 4.120 0.124 96.99 0.53 Polar solution used in Example 3 4.120 0.057 98.62 0.14

[0103] Test conclusion:

[0104] According to Table 1 and Figure 1The results show that the measured free chloride ion concentration in the unmodified raw material used in Comparative Example 3 was 4.153 wt%, and the methanol residue was 38.74 wt%. These untreated components are the main hidden dangers hindering the room temperature curing of the anti-mildew polymer coating. Since this stock solution did not undergo any dehalogenation modification treatment and was only used as a benchmark for determining the initial content, no actual removal reaction occurred. Therefore, its chloride ion removal rate in Table 1 is directly counted as "-". In the initial stage of mixing with organosilicon base material, free halide ions readily undergo coordination reactions with the empty orbitals of the central atom of diisopropoxydiacetylacetone titanium. This coordination competition will cause direct failure of the catalytic system. In practice, once such undechlorinated stock solution is introduced, the prepared colloid still exhibits a viscous, uncrosslinked state after being stored for several weeks, proving that this competitive inhibition against titanate catalysts is almost irreversible.

[0105] After anhydrous silver acetate replacement treatment in Examples 1 to 3, the measured free chloride ion concentration of the precursor solution decreased significantly, with the highest removal rate reaching 98.62%. Controlling the chloride ion concentration to approximately 0.1 wt% avoided its influence on the coordination of the titanium catalyst. As halogen replacement progressed, the introduced acetate ions adjusted the hydrolysis activation energy of the quaternary ammonium salt methoxy group, enabling it to achieve a chemical basis for simultaneous polycondensation with the silane crosslinking agent at room temperature. Furthermore, Examples 1 to 3 removed low-boiling alcohols through vacuum distillation, resulting in measured methanol residues of less than 0.6 wt%. If a large amount of low-boiling methanol is retained during the subsequent high-speed stirring and vacuum degassing process, it can easily induce bubble defects within the rubber compound due to violent vaporization, and even cause long-chain polar molecules to condense and precipitate under ambient temperature storage and transportation conditions. Solvent replacement was achieved by using high-boiling-point dipropylene glycol dimethyl ether. The effectiveness of methanol removal was verified by chromatographic data. The newly added solvent molecules improved the compatibility of polar molecules, improved the problem of stratification of active ingredients after long-term storage, and provided a rheological window for the spontaneous release of quaternary ammonium salt molecules to the air interface during subsequent coating application.

[0106] Test Example 2:

[0107] Experimental objective: To verify the static locking ability of the coating network constructed by titanate coupling agent under neutral immersion environment, and the targeted degradation and effective agent release characteristics of the composite anchoring powder in a simulated fungal metabolic acid solution microenvironment.

[0108] Experimental steps:

[0109] The uncured superhydrophobic antifungal and antialgae polymer formulations obtained in Examples 1 to 3 and Comparative Example 4 were selected as test subjects. Each superhydrophobic antifungal and antialgae polymer formulation was coated onto a 100mm × 100mm cold-rolled steel plate, with a coating thickness controlled at 2.0 mm. The coated samples were placed in a constant temperature and humidity chamber at 25℃ and 50% relative humidity for 7 days to allow complete curing and demolding. The samples were then cut into 20mm × 20mm test films. Multiple films were prepared for each formulation, with a total weight of 5.00 grams accurately weighed for each.

[0110] Two different soaking media were prepared. The first was neutral deionized water, with the pH adjusted to 7.0, to simulate a normal, unpolluted rainfall environment. The second was a metabolic acid buffer solution, specifically prepared by adding oxalic acid and lactic acid to deionized water and finely adjusting the pH with sodium hydroxide to stabilize the final solution at 4.0. This was used to simulate the acidic microenvironment of attached molds or algae secreting metabolites when absorbing nutrients.

[0111] Place the prepared test films into conical flasks containing 100 ml of neutral deionized water and 100 ml of simulated metabolic acid buffer solution, respectively. Seal the conical flasks and place them in a constant temperature, light-proof shaking incubator at 25°C, setting the shaking speed to 100 rpm.

[0112] On days 1, 3, 7, 14, and 21 of soaking, 1.0 mL of soaking solution was taken from each conical flask. Immediately after sampling, 1.0 mL of fresh soaking medium of the same properties was added to the flask. The collected sample solution was filtered through a 0.45 μm microporous membrane, and the filtrate was collected.

[0113] The concentration of zinc pyrithione in the filtrate was determined using a high-performance liquid chromatography (HPLC) system equipped with a UV detector. Before testing, five standard solutions of zinc pyrithione with concentrations of 0.5 μg / mL, 2.0 μg / mL, 5.0 μg / mL, 10.0 μg / mL, and 20.0 μg / mL were prepared according to the external standard method for quantitative analysis. The peak areas of each solution were measured, and a standard working curve of peak area versus concentration was pre-plotted. Filtrate samples collected at each time point were then injected, and the actual peak areas were substituted into the standard working curve to determine the true concentration in the sample solution. Finally, the concentration values ​​measured at each sampling point were multiplied by the total volume of the immersion solution in the conical flask (100 ml), the mass of the reagent taken away in each previous sampling was added, and then divided by the total mass of the film put in (5.00 g). The cumulative release of zinc pyrithione per unit mass of film on the corresponding immersion conditions on the 1st, 3rd, 7th, 14th and 21st days (unit: μg / g) was calculated.

[0114] Experimental results (see Table 2):

[0115] Table 2: Cumulative release of zinc pyrithione in Examples 1 to 3 and Comparative Example 4 under different pH conditions (unit: μg / g)

[0116] Test object Immersion environment Day 1 Day 3 Day 7 Day 14 Day 21 Example 1 Neutral water (pH=7.0) 1.18 1.83 2.37 2.86 3.12 Example 1 Simulated acid (pH=4.0) 15.42 42.61 85.14 134.75 168.21 Example 2 Neutral water (pH=7.0) 0.94 1.45 2.12 2.48 2.81 Example 2 Simulated acid (pH=4.0) 12.87 38.25 79.46 122.58 153.94 Example 3 Neutral water (pH=7.0) 1.51 2.24 2.79 3.42 3.86 Example 3 Simulated acid (pH=4.0) 18.15 49.33 93.68 145.26 181.42 Comparative Example 4 Neutral water (pH=7.0) 1.12 1.54 1.88 2.21 2.45 Comparative Example 4 Simulated acid (pH=4.0) 1.34 1.82 2.45 2.94 3.23

[0117] Test conclusion:

[0118] According to Table 2 and Figure 2 The results show that, in a neutral water immersion environment, the cumulative release of zinc pyrithione from the cured films of Examples 1 to 3 was less than 4.0 μg / g on day 21. This indicates that the coating network constructed in advance using monoalkoxy titanate has good sealing properties in neutral moisture, effectively reducing the unnecessary loss of polar antibacterial agents from the surface of the inorganic carrier, which is beneficial to improving the long-term weather resistance of the formulation.

[0119] When the microenvironment was transformed into a simulated acidic medium with a pH of 4.0, the cumulative release from Examples 1 to 3 increased significantly with prolonged immersion time, exceeding 150 μg / g on day 21. This is because the permeated acidic substances underwent acid-base neutralization and degradation reactions with the internal active zinc oxide and zinc-aluminum hydrotalcite. The local dissolution of the inorganic matrix in the acidic medium disrupted the titanate coupling network structure attached to it, leading to the unsealing and dissolution of the previously blocked agent, thereby achieving a responsive release in response to the acidic microenvironment.

[0120] Comparative Example 4, by using chemically inert silica micropowder instead of acid-responsive zinc-aluminum hydrotalcite and active zinc oxide in the preparation of the composite anchoring powder, showed a cumulative release of only 3.23 μg / g on day 21 in an acidic medium, similar to the release level under neutral conditions. This indicates that silica micropowder is difficult to degrade by weak acids, the coupling network encapsulating the composite powder remains intact, and the internal reagents are not effectively released. In practical applications, when the coating surface is covered with a large amount of dirt and mold grows, the component formulation represented by Comparative Example 4 will lose its bactericidal function through responsive release, demonstrating that introducing a specific acid-responsive inorganic carrier is the core element in constructing the responsive release mechanism of this invention.

[0121] Test Example 3:

[0122] Experimental objective: To verify the spontaneous release process of modified long-chain quaternary ammonium salt molecules from the air interface inside the incompletely cross-linked superhydrophobic antifungal and antialgal polymer liquid film, and to confirm the actual kinetic contribution of introducing vinyl-containing special siloxanes to prolong the skinning time to construct a surface hydrophobic antibacterial defense line.

[0123] Experimental steps:

[0124] The uncured superhydrophobic, antifungal, and antialgae polymer formulations finally prepared in Examples 1 to 3 and Comparative Example 2 were selected as test groups. Each formulation was uniformly coated onto a flat aluminum alloy substrate that had been pre-cleaned with anhydrous ethanol, and the wet film thickness was controlled to 1.0 mm using an adjustable coater. The prepared coating samples were then placed in a constant temperature and humidity test chamber at 25°C and 50% relative humidity for natural curing.

[0125] Three key time points were set to track the migration trajectory of internal elements: 0.5 hours after coating (representing the initial leveling stage), 4.0 hours after coating (representing the delayed crosslinking window), and 168 hours after coating (representing the base adhesive reaching full curing). Upon reaching each of these preset time points, the corresponding coating samples were immediately subjected to instantaneous quenching treatment using liquid nitrogen. The extremely low temperature environment instantly terminates the Brownian motion of the internal polymer chain segments and the crosslinking reaction between groups, thereby accurately locking the three-dimensional spatial arrangement of the macromolecules at the corresponding time.

[0126] After being quenched and fixed in liquid nitrogen, each sample was rapidly transferred to the high-vacuum chamber of an X-ray photoelectron spectroscopy (XPS) instrument for surface element scanning. The detection depth of the instrument was set to be controlled within a very shallow range of 5 nanometers on the coating surface. The sample surface was bombarded with a monochromatic AlKα X-ray source, and the photoelectron signals of the nitrogen characteristic peak (N1s, binding energy approximately 399 eV) reflecting the presence of the polar antibacterial agent and the silicon characteristic peak (Si2p, binding energy approximately 102 eV) reflecting the organosilicon matrix framework were recorded and extracted.

[0127] Unlike conventional physicochemical tests such as liquid chromatography, X-ray photoelectron spectroscopy (XPS) relies directly on the inherent photoelectric emission properties of substances. The specific calculation process is as follows: using the standard relative sensitivity factor (RSF) database built into the XPS instrument analysis software, the integrated areas of the N1s characteristic peak and the Si2p characteristic peak extracted from the surface of each sample are divided by the relative sensitivity factor of the corresponding element, thereby calculating the actual atomic molar percentage content of nitrogen and silicon within the 5-nanometer shallow surface layer. Considering that silicon, as the cross-linking matrix of the superhydrophobic antifungal and antialgae polymer, exists uniformly and abundantly in the system, it is used as an internal reference. The calculated atomic percentage of nitrogen is directly divided by the atomic percentage of silicon to accurately determine the N / Si atomic ratio for each group of samples at 0.5 hours, 4.0 hours, and 168 hours after coating. The dynamic change of this ratio is used to quantitatively characterize the migration and enrichment degree of long-chain quaternary ammonium salt molecules with polar groups to the air interface.

[0128] Experimental results (see Table 3):

[0129] Table 3: Test data of N / Si atomic ratio on the coating surface at different curing stages of Examples 1 to 3 and Comparative Example 2

[0130] Test object N / Si atomic ratio at 0.5 hours 4.0-hour N / Si atomic ratio 168-hour N / Si atomic ratio Example 1 0.023 0.067 0.108 Example 2 0.019 0.058 0.097 Example 3 0.026 0.072 0.114 Comparative Example 2 0.022 0.024 0.026

[0131] Test conclusion:

[0132] According to Table 3 and Figure 3 The results show that, in the initial leveling stage (0.5 hours after coating), the N / Si atomic ratios on the surfaces of the four test groups were between 0.019 and 0.026. At this time, the polymer formulation had not yet undergone significant three-dimensional rearrangement, and the introduced polar quaternary ammonium salt agent was uniformly dispersed in the bulk medium. As the curing time increased to 4.0 hours, the N / Si atomic ratios on the surfaces of Examples 1 to 3 increased significantly, eventually reaching approximately 0.10 upon complete curing at 168 hours. The enrichment of nitrogen in the shallow surface layer is due to the low surface free energy of quaternary ammonium salt molecules with long carbon chains, which tend to migrate towards the air interface in the medium where the liquid phase has not yet completely solidified, thus achieving enrichment on the coating surface.

[0133] The aforementioned migration process requires a sufficiently long liquid leveling window in the matrix. In Comparative Example 2, due to the absence of a vinyltriisopropoxysilane with steric hindrance to suppress the crosslinking rate, the coating of this formulation exhibited crosslinking and crusting shortly after contact with air moisture. The rapidly formed three-dimensional polymer network blocked the migration pathways of polar molecules, resulting in a maximum N / Si atomic ratio of only 0.026 in Comparative Example 2 over the subsequent 168 hours, indicating that the antibacterial agent was confined within the matrix. The comparative data demonstrate that extending the leveling time before crosslinking using a specific vinyl-containing siloxane is a necessary condition for achieving the migration of quaternary ammonium salt molecules to the surface and constructing surface antibacterial functions.

[0134] Test Example 4:

[0135] Experimental objective: To verify the effects of halide ion removal, inorganic powder surface coupling coating, and a reasonable multi-stage blending feeding sequence on the catalytic curing kinetics and long-term storage stability of superhydrophobic antifungal and antialgae polymer formulations, and to confirm the actual contribution of each process intervention step in the formulation to preventing poisoning of organotitanium catalysts and inhibiting the precipitation of polar quaternary ammonium salt molecules.

[0136] Experimental steps:

[0137] The uncured superhydrophobic antifungal and antialgae polymer formulations finally prepared in Examples 1 to 3, as well as Comparative Examples 1, 3, and 5, were selected as test subjects. The uncured superhydrophobic antifungal and antialgae polymer formulations of each group were injected into a standard polytetrafluoroethylene mold with a cross-sectional size of 10 mm × 2 mm and smoothed with a scraper.

[0138] Each set of filled molds was placed flat in a constant temperature and humidity test chamber at 23℃ and 50% relative humidity. Timing began from the moment the superhydrophobic, mildew-proof, and algae-resistant polymer formulation came into contact with the ambient temperature and humidity. A dry polyethylene film was used to periodically and lightly touch the surface of the formulation. When the film was removed and no formulation adhered to the surface, the time interval was recorded. This time is the surface drying time for each set of samples. Subsequently, the samples were kept in the constant temperature and humidity environment for curing. The colloid was periodically longitudinally cut to determine the internal curing state. The time from the surface layer to the innermost layer where no uncured liquid phase remained was recorded. This time is the complete curing time for each set of samples.

[0139] The newly prepared uncured superhydrophobic antifungal and antialgae polymer formulations were filled into standard sealed aluminum tubes and then crimped and sealed at the tail. The initial viscosity of each group of samples at room temperature (25°C) was tested using a rotational viscometer. Subsequently, the sealed aluminum tubes were transferred to a constant temperature aging chamber set at 50°C for a 30-day accelerated storage test.

[0140] After the accelerated storage period, the aluminum tube was removed and allowed to stand at room temperature for 24 hours to recover. The final viscosity of the superhydrophobic antifungal and antialgae polymer formulation inside the tube was measured again using the same rotational viscometer. The difference between the final viscosity and the initial viscosity was divided by the initial viscosity, and the calculated percentage was the viscosity change rate after 30 days of accelerated storage at 50°C. Finally, the aluminum tube was longitudinally cut open with a utility knife, and the presence of abnormal phenomena such as powder particle aggregation, liquid phase separation, and stratification inside the superhydrophobic antifungal and antialgae polymer formulation was directly observed with the naked eye to obtain specific results of the macroscopic observation after storage.

[0141] Experimental results (see Table 4):

[0142] Table 4: Curing time and storage stability test data for Examples 1 to 3 and their corresponding proportions

[0143] Test object Drying time (min) Complete curing time (h) Viscosity change rate (%) after 30 days of accelerated storage at 50℃ Macroscopic observation after storage Example 1 38 36 +4.2 Uniform and consistent, with no precipitation Example 2 32 31 +3.8 Uniform and consistent, with no precipitation Example 3 45 41 +5.1 Uniform and consistent, with no precipitation Comparative Example 1 115 89 +16.7 Localized agglomeration of powder particles Comparative Example 3 385 Incompletely cured +42.5 The adhesive layered, with a large amount of liquid precipitating out. Comparative Example 5 185 168 +28.3 There is obvious oily substance on the surface.

[0144] Test conclusion:

[0145] According to the data in Table 4, the surface drying time of Examples 1 to 3 under normal temperature and humidity conditions ranged from 32 to 45 minutes, and the complete curing time remained stable at 31 to 41 hours. After 30 days of accelerated storage at 50°C, the viscosity change rate was controlled within 5.1%, and the macroscopic physical state was uniform with no precipitation. This indicates that the superhydrophobic antifungal and antialgae polymeric formulation prepared using the pretreatment process and specific blending sequence of this invention possesses excellent curing performance and storage stability.

[0146] In contrast, the surface drying time of Comparative Example 3 was extended to 385 minutes. Even after prolonged curing, the internal structure remained incompletely cross-linked, and the accelerated aging process led to a 42.5% increase in viscosity and the precipitation of a large amount of liquid phase. This is because the untreated quaternary ammonium salt methanol solution retained a large number of free chloride ions. These free chloride ions undergo coordination reactions with the diisopropoxydiacetylacetone titanium catalyst, causing catalyst deactivation. This hinders the condensation and de-alcoholization cross-linking reaction between the organosilicon terminal hydroxyl groups and the cross-linking agent alkoxy groups, thus affecting the establishment of the cross-linked network.

[0147] Comparative Example 1, by omitting the coupling coating step on the powder surface, resulted in a prolonged curing time of 89 hours, and localized particle agglomeration occurred after high-temperature aging. This is because the uncoupled powder surface contains a large number of polar hydrophilic hydroxyl groups. These groups consume the crosslinking agent, leading to uneven local crosslinking density and causing phase separation between the inorganic powder and the organosilicon matrix.

[0148] In Comparative Example 5, an acetic acid-based quaternary ammonium salt polar solution and composite anchoring powder were pre-mixed before the hydroxyl-terminated polydimethylsiloxane completed crosslinking and end-capping. This resulted in a prolonged curing time and the appearance of noticeable oily droplets on the surface of the cured sample. This is because the introduction of polar solvents and powders in the early stages of polymer backbone construction hindered the crosslinking of macromolecular segments. An incompletely crosslinked polymer network cannot effectively physically encapsulate functional additives, leading to the aggregation and precipitation of quaternary ammonium salt molecules, which in turn affects the structural integrity and storage stability of the formulation.

[0149] Test Example 5:

[0150] Experimental Objective: To verify the actual intervention effect of introducing a vinyl-containing special siloxane (vinyltriisopropoxysilane) into the formulation on the construction of hydrophobic function and life extension of the surface of superhydrophobic antifungal and antialgal polymer formulation, and to clarify the influence of the cross-linking skinning rate on the kinetics of the directional migration and enrichment process of hydrophobic long alkyl carbon chain polar molecules to the air interface.

[0151] Experimental steps:

[0152] The uncured superhydrophobic antifungal and antialgae polymer formulations finally prepared in Examples 1 to 3 and Comparative Example 2 were selected as test groups. Each formulation was uniformly coated onto a pre-cleaned hot-dip galvanized steel substrate, with the wet film thickness controlled to 0.5 mm using a coater. Subsequently, each coated sample was placed in a constant temperature and humidity environment of 23°C and 50% for 168 hours to allow the superhydrophobic antifungal and antialgae polymer formulation to reach a fully cross-linked and cured state.

[0153] The initial surface wettability of each group of cured samples was determined using an optical contact angle meter. A 5 μL droplet of deionized water was precisely added to the sample surface using a micro-syringe. The angle between the droplet edge and the sample surface was read directly from the optical projection scale of the optical contact angle meter; this value was recorded as the initial static water contact angle. Subsequently, the rotating platform of the optical contact angle meter was operated to slowly tilt the test stage supporting the sample. At the instant the droplet began to slide off the sample surface, rotation was stopped, and the physical tilt angle of the test stage relative to the horizontal plane was read; this reading was the initial roll angle. The above measurement was repeated 5 times for each sample at different positions, and the arithmetic mean was taken as the final recorded data.

[0154] Each group of samples, after initial parameter determination, was fixed on a standard experimental stand, and the stand angle was precisely adjusted to maintain a 45-degree inclination between the sample plane and the horizontal plane. A constant-flow peristaltic pump was used to continuously and uniformly spray and rinse the coating surface of each sample with deionized water at a constant flow rate of 2.5 liters / minute for 96 hours to simulate the continuous water flow physical shearing process of the superhydrophobic anti-mildew and anti-algae polymer formulation under heavy outdoor rainfall.

[0155] After the rinsing test cycle, each group of samples was removed and allowed to air dry at ambient temperature for 24 hours. Using an optical contact angle meter again, following the same projection scale reading method described above, the angle between water droplets on the surface of each sample was measured and recorded as the static water contact angle after 96 hours of rinsing. The difference between the initial static water contact angle and the static water contact angle after 96 hours of rinsing, divided by the initial static water contact angle, yielded the contact angle decay rate. This parameter is used to evaluate the hydrophobic lifetime durability of the superhydrophobic antifungal and antialgae polymer formulation after water rinsing aging.

[0156] Experimental results (see Table 5):

[0157] Table 5: Surface wettability and water erosion resistance test data of Examples 1 to 3 and Comparative Example 2

[0158] Test object Initial static water contact angle (°) Initial roll angle (°) Static water contact angle (°) after 96 hours of flushing Contact angle attenuation rate (%) Example 1 156.4 4.2 152.1 2.75 Example 2 153.8 5.6 148.9 3.19 Example 3 158.1 3.5 154.2 2.47 Comparative Example 2 124.6 28.5 98.3 21.11

[0159] Test conclusion:

[0160] According to the data in Table 5, the initial static water contact angle of Examples 1 to 3 was greater than 150°, and the initial roll-off angle was between 3.5° and 5.6°. After 96 hours of continuous water rinsing, the contact angle decay rate remained between 2.47% and 3.19%, which indicates that the formulation prepared by the present invention has good hydrophobic properties and water flow rinsing durability.

[0161] The improved hydrophobicity is related to the introduction of vinyltriisopropoxysilane into the formulation. This component, with its large isopropoxy group in its molecular structure providing strong steric hindrance, slows down the condensation reaction rate between the terminal hydroxyl polydimethylsiloxane and the crosslinking agent in the superhydrophobic antifungal and antialgae polymer, thus extending the leveling time of the adhesive before crosslinking and curing. During this period, polar quaternary ammonium salt molecules with low surface free energy and long alkyl carbon chains can migrate and accumulate at the interface between the coating and air. This highly concentrated long alkyl carbon chain, together with the composite anchoring powder within the formulation, creates a synergistic effect in the physical dimension, constructing a hydrophobic structure on the surface of the formulation.

[0162] In Comparative Example 2, due to the absence of vinyltriisopropoxysilane, the superhydrophobic antifungal and antialgal polymer formed a cross-linked skin on its surface within a short period after contact with ambient moisture. The rapidly formed three-dimensional polymer network blocked the migration pathways of the polar quaternary ammonium salt molecules, resulting in the hydrophobic long alkyl carbon chains being confined within the superhydrophobic antifungal and antialgal polymer and failing to accumulate effectively on the surface. This lack of interfacial components directly caused the initial static water contact angle of Comparative Example 2 to decrease to 124.6°, failing to achieve superhydrophobic characteristics.

[0163] Furthermore, the small amount of free quaternary ammonium salt remaining on the surface of Comparative Example 2, due to the lack of effective physical locking at the cross-linking nodes of the polymer three-dimensional network, is prone to detachment and dissolution under the physical shearing action of continuous water flow. Its static water contact angle decreased to 98.3° after scouring, with a contact angle attenuation rate of 21.11%. This indicates that introducing special siloxane molecules to regulate the cross-linking and crusting time helps polar molecules migrate to the surface and anchor at the network nodes, thereby improving the hydrophobic and antifouling lifespan of the superhydrophobic antifungal and antialgae polymer formulation under water scouring conditions.

[0164] Test Example 6:

[0165] Experimental Objective: To verify the anti-mold and anti-algae efficacy of superhydrophobic anti-mold and anti-algae polymeric formulations in both conventional exposure environments and polluted physical shielding environments, and to clarify the actual protective effect of quaternary ammonium salt surface contact sterilization and deep anti-mold agent response release mechanisms in the application scenario of surface protection for power metal equipment.

[0166] Experimental steps:

[0167] The uncured superhydrophobic antifungal and antialgae polymer formulations finally prepared in Examples 1 to 3, and Comparative Examples 2 and 4 were selected as test groups. Uncoated bare plates of the same material were prepared as a blank control group. The uncured superhydrophobic antifungal and antialgae polymer formulations of each group were uniformly coated onto pre-cleaned carbon steel plates, and the wet film thickness was controlled to 1.0 mm using a coating device. After coating, each group of samples was placed in a constant temperature and humidity environment of 23°C and 50% for 168 hours to allow the superhydrophobic antifungal and antialgae polymer formulation to reach a fully cross-linked and cured state.

[0168] The solidified test subjects and blank control group were divided into anti-mildew test batches and anti-algae test batches, and each batch independently included a conventional exposure group and a dirt-covered group.

[0169] Part 1: Independent testing of anti-mildew efficacy.

[0170] To prepare a mixed mold spore suspension, Aspergillus niger and Aspergillus flavus were selected as the strains, and the spore concentration was adjusted to 1×10⁻⁶. 6 CFU / mL.

[0171] Routine exposure group: A mixed mold spore suspension was evenly sprayed onto the sample surface, with an inoculation amount controlled at 0.5 ml / cm². The sample was then placed in a constant temperature and humidity incubator at 28°C and 95% relative humidity for 28 days of routine exposure for mold prevention.

[0172] Contamination Masking Group: A 2.0 mm thick layer of mixed contamination medium, composed of kaolin and soluble salt in a 3:1 mass ratio, was uniformly applied to the sample surface to simulate the contamination masking state of metal surfaces in outdoor polluted areas. An equal volume of mixed mold spore suspension was sprayed onto the contamination medium surface, and the samples were transferred to an incubator under identical conditions for a 28-day contamination-prevention mold culture.

[0173] Part Two: Independent Testing of Anti-Algae Efficacy.

[0174] Prepare a mixed algal suspension using *Hypericum heterotropoides* and *Hypericum elliptica* species, adjusting the cell concentration to 1 × 10⁻⁶. 6 per mL.

[0175] Following the same routine exposure and contamination treatment method as the above anti-mildew test, the mixed algae suspension was inoculated onto another batch of samples and the surface of the contamination layer, and placed in a light-temperature constant temperature incubator with a set temperature of 25°C and a light-dark cycle of 12 hours / 12 hours for 28 days of anti-algae culture.

[0176] After the culture and testing cycle was completed, samples from each batch and their corresponding blank control groups were sequentially removed. The sample coating surface and contaminant layer were repeatedly rinsed with sterile physiological saline containing 0.1% surfactant. The eluent was collected and serially diluted. The diluted solutions were inoculated onto the corresponding culture media using the standard plate coating method, and colony / algae counts were performed after incubation. Based on the total volume of the eluent and the sample surface area, the total number of surviving microorganisms per square centimeter was calculated. The logarithm of the total survival count was taken to obtain the logarithm of survival in the conventional environment and the logarithm of survival in the contaminated environment. By subtracting the total survival count of the experimental group samples from the total survival count of the blank control group, dividing the difference by the total survival count of the blank control group, and multiplying by 100%, the anti-mold and anti-algae rates for each group of samples were calculated.

[0177] Experimental results (see Tables 6 and 7):

[0178] Table 6: Multi-environment anti-mildew efficacy test data of Examples 1 to 3 and Comparative Examples 2 and 4

[0179] Test object Conventional environmental survival log values (log CFU / cm 2 ) Mildew prevention rate in normal environments (%) <![CDATA[Logarithmic value of survival in a fouled environment (logCFU / cm 2 )]]> Mildew prevention rate in contaminated environments (%) Example 1 1.22 99.88 1.45 99.52 Example 2 1.15 99.92 1.38 99.64 Example 3 1.31 99.81 1.52 99.43 Comparative Example 2 3.42 85.15 1.63 99.21 Comparative Example 4 1.48 99.54 4.75 35.26

[0180] Table 7: Multi-environmental algae resistance test data of Examples 1 to 3 and Comparative Examples 2 and 4

[0181] Test object Log survival rate in normal environment (log / cm2) Algae resistance rate in normal environments (%) Logarithmic survival rate in contaminated environments (log / cm2) Algae resistance rate in contaminated environments (%) Example 1 1.18 99.90 1.42 99.55 Example 2 1.12 99.93 1.36 99.68 Example 3 1.25 99.85 1.50 99.48 Comparative Example 2 3.28 86.42 1.58 99.30 Comparative Example 4 1.45 99.60 4.68 37.15

[0182] Test conclusion:

[0183] According to the data in Tables 6 and 7, the anti-mold and anti-algae rates of Examples 1 to 3 all reached over 99.81% under normal exposure conditions. Under physical shielding conditions with a 2.0 mm layer of mixed contaminated medium, the anti-mold and anti-algae rates of the three formulations remained between 99.43% and 99.68% in contaminated environments. This data indicates that the superhydrophobic anti-mold and anti-algae polymer formulations possess anti-mold and anti-algae capabilities under both normal exposure and contaminated shielding conditions.

[0184] The antifungal and antialgal properties of the formulation under normal conditions are related to the surface enrichment mechanism of polar quaternary ammonium salt molecules. Quaternary ammonium salt molecules with long alkyl carbon chains migrate towards the air-side interface of the formulation, and the surface-enriched quaternary ammonium salt cationic groups disrupt the cell membranes of attached microorganisms through electrostatic adsorption. In Comparative Example 2, the polar quaternary ammonium salt molecules failed to effectively accumulate on the coating surface, resulting in a decrease in the antifungal rate to 85.15% and the antialgal rate to 86.42% under unshielded normal conditions. This data indicates that the contact bactericidal mechanism of quaternary ammonium salts on the coating surface is the main source of the antifungal and antialgal properties under normal conditions.

[0185] In a contaminated, shielded environment, the contact sterilization effect of the coating surface is blocked. In Comparative Example 4, because the internal composite powder lacks acid degradation properties, the anti-mold and anti-algae agent cannot be released, resulting in a decrease in the anti-mold rate to 35.26% and the anti-algae rate to 37.15% in a contaminated environment. In Examples 1 to 3, when microbial metabolism produces acid, acidifying the microenvironment of the contaminated layer, the inorganic matrix of the internal anchoring powder undergoes acid neutralization and degradation, thereby releasing the anti-mold and anti-algae agent to the external contaminated layer. Comparative Example 2, relying on the release of the internal agent in a contaminated environment, achieves an anti-mold rate of 99.21% and an anti-algae rate of 99.30%, further verifying the anti-mold and anti-algae effect of the internal composite powder in a shielded environment.

[0186] Test results show that this polymer formulation, through the combination of surface quaternary ammonium salt contact sterilization and internal composite powder acid degradation release agent, has anti-mildew and anti-algae functions under normal exposure and physical isolation of filth conditions.

[0187] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A superhydrophobic, antifungal, and antialgae polymeric formulation, characterized in that, Made from the following ingredients in parts by weight: Hydroxyl-terminated polydimethylsiloxane: 100 parts; Hydrophilic fumed silica: 5-15 parts; Methyltrimethoxysilane: 3-7 parts; Vinyltriisopropoxysilane: 1-3 parts; Diisopropoxydiacetylacetone titanium: 1.0-2.0 parts; Acetic acid-type quaternary ammonium salt polar solution: 13.2-21.39 parts; Composite anchoring powder: 3.2-9.5 parts; The acetic acid-type quaternary ammonium salt polar solution is prepared by a method comprising the following steps: A dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride methanol solution was stirred with anhydrous silver acetate powder under light-protected conditions to undergo a halide ion replacement reaction. After filtering to remove the silver chloride precipitate, an acetate-type quaternary ammonium salt methanol filtrate was obtained. Subsequently, dipropylene glycol dimethyl ether was added to the methanol filtrate of the acetic acid-type quaternary ammonium salt, and vacuum distillation was carried out under heating conditions until no methanol fraction was distilled off, to obtain the polar solution of the acetic acid-type quaternary ammonium salt. The composite anchoring powder is prepared by a method including the following steps: Active zinc oxide, zinc aluminum hydrotalcite, zinc pyrithione, and pyrazinamide are added to a mixer and stirred and dispersed to obtain a mixed primary powder. Isopropyl trioleoyl oxytitanate was sprayed into the primary mixed powder while maintaining stirring. After high-speed mixing and discharge, a composite anchoring powder with the surface coated by the titanate coupling agent was obtained.

2. The superhydrophobic antifungal and antialgae polymeric formulation according to claim 1, characterized in that, The raw materials used to prepare the acetic acid-type quaternary ammonium salt polar solution include, by weight: The following components are present: 5.0-10.0 parts of a 60% dimethyl octadecyl [3-(trimethoxysilyl)propyl]ammonium chloride methanol solution, 1.06-2.12 parts of anhydrous silver acetate powder, and 10.0-15.0 parts of dipropylene glycol dimethyl ether.

3. The superhydrophobic antifungal and antialgae polymeric formulation according to claim 1, characterized in that, The raw materials used to prepare the composite anchoring powder include, by weight: 1.5-3.5 parts of active zinc oxide, 0.5-1.5 parts of zinc aluminum hydrotalcite, 0.5-2.0 parts of zinc pyrithione, 0.5-2.0 parts of pyrazinamide, and 0.2-0.5 parts of isopropyltrioleyloxytitanate.

4. The superhydrophobic antifungal and antialgae polymeric formulation according to claim 1, characterized in that, The hydroxyl-terminated polydimethylsiloxane has a dynamic viscosity between 2000-5000 mPa·s at 25°C. The specific surface area of ​​the hydrophilic fumed silica, measured by nitrogen adsorption, is between 150 and 250 m². 2 Between / g.

5. A preparation process for the superhydrophobic antifungal and antialgae polymeric formulation according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Hydroxyl-terminated polydimethylsiloxane is mixed and stirred with hydrophilic fumed silica. The mixture is heated to increase its temperature, and at the same time, vacuuming and depressurization are performed to remove moisture. After mixing, the matrix adhesive is obtained. S2. Cool the matrix adhesive, introduce nitrogen to restore the internal pressure of the mixing environment to normal and maintain a slight positive pressure protection, then add methyltrimethoxysilane, vinyltriisopropoxysilane and diisopropoxydiacetylacetonitrile titanium and stir to complete the cross-linking and end-capping to obtain the end-capped base adhesive. S3. Add an acetic acid-type quaternary ammonium salt polar solution and composite anchoring powder to the end-sealing base adhesive, mix them together, and simultaneously perform a vacuuming and depressurization operation to remove air bubbles generated during the mixing process, thereby obtaining a superhydrophobic, mildew-proof, and algae-resistant polymer formulation.

6. The preparation process of the superhydrophobic antifungal and antialgae polymeric agent according to claim 5, characterized in that, In step S1, the heating raises the temperature of the mixture to 110-130°C, the mixing speed is 600-1000 rpm, and the time is 1.5-2.5 hours.

7. The preparation process of the superhydrophobic antifungal and antialgae polymeric agent according to claim 5, characterized in that, In step S2, the matrix adhesive is cooled to 35-45°C, and the stirring speed is 300-500 rpm for 20-40 minutes.

8. The preparation process of the superhydrophobic antifungal and antialgae polymeric agent according to claim 5, characterized in that, In step S3, the blending temperature is controlled at 35-45℃, the rotation speed is 400-800 rpm, and the time is 0.5-1.5 hours; the vacuuming and depressurization operation controls the absolute pressure to be maintained between 0.05-0.08 MPa.

Images