Antibacterial type silicone leveling agent, preparation method and application thereof

Abstract

The application relates to the technical field of fine chemical additives, in particular to an antibacterial organic silicon leveling agent and a preparation method and application thereof. The antibacterial organic silicon leveling agent comprises a comb structure polysiloxane and is prepared by chemically bonding specific proportions of alkyne diol blocks and eugenol antibacterial functional groups on a main chain. A step-by-step silicon hydrogen addition process is adopted in the preparation method, so that the antibacterial groups preferentially occupy the molecular chain ends, and the wetting and defoaming groups are distributed in the middle part. The application can reduce the dynamic surface tension by using the alkyne diol structure and inhibit bubbles, and simultaneously provide broad-spectrum and long-acting antibacterial performance through the chemically bonded eugenol. The leveling agent has stable solubility in a water-based or UV system, solves the problems of easy loss of the antibacterial agent and invalidation of the additive compounding, and significantly improves the comprehensive protection performance and leveling effect of a coating.

Description

Technical Field

[0001] This invention belongs to the field of fine chemical additives technology, specifically an antibacterial organosilicon leveling agent, its preparation method, and its application. Background Technology

[0002] Organosilicon additives, especially polyether-modified polysiloxanes, are an indispensable component of modern coatings and ink systems. They are widely used as leveling agents, defoamers, wetting agents, and slip agents, effectively improving the appearance and properties of coatings.

[0003] However, existing silicone additive technologies have many limitations. First, most commercial products have a single function. As a result, coating formulators need to compound multiple additives in the formulation, which not only increases the complexity and cost of the formulation, but may also lead to competition, repulsion, or even failure between additives, affecting the final performance of the coating film.

[0004] Secondly, with increasingly stringent environmental regulations, the demand for low-VOC (volatile organic compounds) and sustainable materials is becoming more urgent. Traditional silicone additives are mainly based on petroleum derivatives, with low bio-based content, which does not align with the development trend of green chemistry. In addition, some additives with special functions (such as antibacterial properties) usually need to be added separately through physical mixing, which may introduce compatibility issues or lead to short-lasting functionality.

[0005] Furthermore, as people's living standards continue to improve, hygiene conditions urgently need further optimization. In crowded public places such as hospitals, schools, and public transportation, frequently touched surfaces (such as door handles, handrails, and buttons) are breeding grounds for bacteria and viruses. Traditional cleaning methods have intermittent periods and limited continuous protective capabilities, leading to a significant increase in the risk of cross-infection.

[0006] Traditional polyether-modified polysiloxanes typically only improve leveling properties, and the polyether segments are mostly conventional ethylene oxide / propylene oxide copolymers, with room for improvement in bio-based content and antibacterial function. Therefore, there is an urgent need in this field to develop a novel, environmentally friendly, and high-performance additive that integrates multiple functions.

[0007] Patent CN113930172A discloses an antibacterial film composed of an acrylic ultraviolet resin, a silver nanoparticle antibacterial agent, and an organosilicon leveling agent for improving surface smoothness. This technology imparts coating functionality by physically compounding the antibacterial agent and the organosilicon leveling agent in the coating formulation. However, this method of physically adding antibacterial components can easily lead to limited compatibility and stability between the leveling agent and the antibacterial agent in the system, and challenges are posed to the uniformity and long-term effectiveness of the antibacterial components on the coating surface.

[0008] Patent CN107987693A discloses a durable antibacterial waterborne alkyd coating, composed of a structural antibacterial waterborne alkyd resin, fillers, leveling agents, etc. This technology fixes antibacterial groups onto the alkyd resin structure through chemical bonds, achieving antibacterial properties of the resin itself. However, the leveling agent in this solution is still added as an independent functional additive, and the leveling agent itself does not possess antibacterial activity. This results in a complex mixture of additives in the coating system, and the synergistic efficiency between additives and the degree of formulation simplification still need further optimization. Summary of the Invention

[0009] This application provides an antibacterial organosilicon leveling agent, its preparation method, and its application. The leveling agent forms a comb-like structure with multifunctional side chains by chemically bonding a specific ratio of acetylenic diol blocks and eugenol antibacterial functional groups to the polysiloxane backbone.

[0010] In a first aspect, this application provides a leveling agent that is a comb-shaped polysiloxane of the general formula shown, wherein the general formula of the comb-shaped polysiloxane is: ; in: a is a number from 1 to 15; b is a number from 1 to 10, satisfying b ≤ a ≤ 1.5b; R 1 It is a C1-C6 alkyl or phenyl group, wherein the methyl group is in the R group. 1 The proportion of the total number of functional groups shall not be less than 75%; R 2 R 3 For the side chains of the comb-like structure, at least one of structure P and structure T is: The structure P is a block formed by the hydrosilylation reaction of an acetylide diol compound. The structure T is an antibacterial functional group formed by the hydrosilylation reaction of eugenol and its derivatives derived from biological sources.

[0011] According to this application, by introducing structures P and T into the polysiloxane molecular chain, the low surface tension of the siloxane backbone is utilized to provide spreading properties. The acetylenic diol block in structure P contains symmetrical hydrophobic groups and a central polar hydroxyl group, generating dynamic wetting in the coating system. Structure T is derived from natural eugenol, and its phenolic hydroxyl and methoxy groups together constitute the antibacterial active center. By fixing structures P and T to the siloxane side chain through chemical bonds, the migration of additives during film formation is avoided, resulting in a uniformly functionally distributed layer on the coating surface.

[0012] In the general formula of the comb-like polysiloxane, the ratio of a to b has a decisive influence on the performance of the leveling agent. When a is controlled between 1 and 15, b is controlled between 1 and 10, and the a / b ratio is between 1 and 1.5, the length of the polysiloxane backbone and the density of the side chains reach equilibrium. This specific chain segment distribution allows the molecule to have a suitable hydrodynamic volume in the coating system, ensuring both solubility in the solvent and the formation of a tightly packed monomolecular layer at the interface. If the value of a is too large, the siloxane backbone will be too long, leading to a decrease in the compatibility of the additive in the aqueous system and making it prone to oil spots or haze; if the value of b is too large, the side chains will be too dense, and steric hindrance will limit the effective exposure of the eugenol antibacterial groups, reducing the antibacterial efficiency.

[0013] Preferably, the structure T is defined by the following general formula: In the eugenol structure, the propenyl group is attached to the silicon repeating unit via a hydrosilylation reaction, wherein the substituent R 4 It can be hydrogen, alkyl, aryl, or a functional fragment, wherein the functional fragment is a sugar, terpene, or steroid. In specific application scenarios, R 4 Preferably, it contains hydrogen or a water-soluble monosaccharide group. When R 4 When the group is a water-soluble monosaccharide, structure T regulates the hydrophilic equilibrium of the leveling agent in the aqueous system through the polyhydroxy structure of the sugar ring.

[0014] In structure T, the eugenol functional group is attached to the end or side of the polysiloxane via a hydrosilylation reaction. The methoxy and phenolic hydroxyl groups in the eugenol molecule are polar groups, while the benzene ring structure exhibits some hydrophobicity. This amphiphilic characteristic allows structure T to guide the migration of siloxane molecules to the surface. Simultaneously, chemical bonding replaces traditional physical mixing, making the antibacterial monomer part of the polymer chain. When the coating is subjected to mechanical wear or water erosion, the antibacterial components are not easily lost like small-molecule antibacterial agents, thus maintaining the long-term hygienic protective capability of the coating surface.

[0015] Preferably, the structure P is defined by the following general formula: It is an alkenylsilane group formed by the hydroaddition of a symmetrically structured acetylacetonate derivative with silylation. Wherein: R 5 R 6 It is a hydrogen-containing or polyether containing polyoxyethylene (EO) and polyoxypropylene (PO) groups, wherein the polyether is terminally capped with hydroxyl or acetyl groups. R 5 R 6 The molar ratio of EO segments to PO segments is controlled between 1:0.5 and 1:2.

[0016] The acetylinyl diol block introduced by structure P is key to resolving the contradiction between defoaming and wetting in this application. Traditional polyether-modified silicone oils often introduce excessive foam, while the acetylinyl diol structure, due to the rigidity of its central carbon-carbon triple bond and symmetrical alkyl side chains, can disrupt the surface pressure balance of the bubble-liquid film, thus producing a defoaming effect. In the synthesis process of this application, by adjusting R... 5 R 6 The ratio of EO to PO can fine-tune the HLB value (hydrophilic-lipophilic balance) of the leveling agent. When the EO content increases, the dispersion stability of the leveling agent in the aqueous system improves; when the PO content increases, its defoaming ability and smoothness are enhanced.

[0017] Preferably, in the polysiloxane with structure P, R 2 With R containing structure T 2 The molar ratio is 0.05:1 to 0.2:1, and R contains structure P. 3 Side chains and R containing structure T 3 The molar ratio of the side chains is 1:0.05 to 1:0.5. This ratio ensures that when the leveling agent is oriented on the coating surface, the antibacterial groups and wetting groups are arranged in an alternating pattern in both the horizontal and vertical directions.

[0018] Secondly, this application provides a method for preparing an antibacterial organosilicon leveling agent, comprising the following steps: S10: Provides a hydrogen-containing polysiloxane, wherein the molecular structure of the hydrogen-containing polysiloxane contains terminal hydrogen (Si-H) and side hydrogen (Si-H). The hydrogen-containing polysiloxane is prepared by an equilibrium reaction of octamethylcyclotetrasiloxane, a hydrogen-containing cyclic compound, and an end-capping agent in the presence of an acidic catalyst.

[0019] S20: Under the protection of an inert gas and in the presence of a platinum catalyst, the temperature of the reaction system is controlled at 70 to 100°C. Eugenol compounds are first added to the system to allow the terminal hydrogen in the hydrogen-containing polysiloxane to undergo a hydrosilylation reaction with the allyl group of the eugenol compound. The reaction time is 1 to 2 hours. The change of the Si-H signal of the terminal group is monitored by infrared spectroscopy to obtain a siloxane intermediate containing antibacterial groups. S30: To maintain the activity of the platinum catalyst, the temperature of the reaction system is raised to 90 to 110°C, and an acetylenic diol compound is added dropwise to the intermediate, so that the remaining side hydrogens undergo a hydrosilylation reaction with the unsaturated bonds in the acetylenic diol compound, and the reaction time is 4 to 8 hours. S40: Detection system at 2160cm using infrared spectroscopy. -1 The Si-H characteristic absorption peak was detected at the site. When the peak disappeared, the reaction was stopped, cooled to room temperature, and filtered to obtain an antibacterial organosilicon leveling agent.

[0020] According to this application, the preparation method employs a stepwise addition process. Due to the difference in reactivity between terminal and side hydrogens, and the difference in steric hindrance between eugenol compounds and acetylenol compounds, a programmed temperature increase method, first at low temperatures and then at high temperatures, allows the antibacterial groups to preferentially occupy the ends of the molecular chain, while the wetting and defoaming groups are distributed in the middle of the molecular chain. This structural distribution results in a more regular spreading morphology of the leveling agent molecules at the interface.

[0021] Preferably, in step S10, the raw materials for synthesizing hydrogen-containing polysiloxane include: 150 to 250 parts of octamethylcyclotetrasiloxane, 80 to 120 parts of 1,3,5,7-tetramethylcyclotetrasiloxane, and 70 to 110 parts of tetramethyldisiloxane; acidic clay or macroporous strong acidic cation exchange resin is used as a catalyst, and the equilibrium reaction is carried out at 70 to 90°C for 8 to 12 hours.

[0022] Preferably, in steps S20 and S30, the platinum catalyst is selected from an isopropanol solution of chloroplatinic acid, an ethanol solution of chloroplatinic acid, or a caster catalyst; the amount of platinum catalyst added, based on the mass of platinum metal, is 10 to 50 ppm of the total mass of the reactants. In a preferred embodiment, the concentration of platinum metal is controlled at 20 ppm.

[0023] Preferably, the eugenol compound used in step S20 is selected from at least one of eugenol, eugenol methyl ether, and acetyleugenol; the alkynyldiol compound used in step S30 is selected from 2,4,7,9-tetramethyl-5-decyn-4,7-diol, 1,4-butynyldiol and their polyoxyethylene / polyoxypropylene etherification products, wherein the molecular weight of the etherification product is 150 to 800.

[0024] Preferably, the preparation method further includes a decolorization step. Before filtration, 0.1% to 0.5% of activated carbon by weight of the total product is added to the product, and the mixture is stirred at 60 to 80°C for 1 to 2 hours to remove residual color produced by the platinum catalyst.

[0025] Thirdly, this application provides a coating or ink composition containing the aforementioned antibacterial silicone leveling agent, wherein the antibacterial silicone leveling agent accounts for 0.5% to 2.0% by mass in the composition.

[0026] Preferably, the composition is an aqueous industrial coating. Its formulation components include: 40 to 60 parts of film-forming resin, 10 to 30 parts of pigments and fillers, 15 to 30 parts of deionized water, 2 to 8 parts of film-forming aid, 0.1 to 0.5 parts of neutralizing agent, and 0.5 to 2.0 parts of the multifunctional silicone leveling agent described in this application.

[0027] Preferably, the composition is a UV-curable ink. Its formulation components include: 80 to 95 parts of a UV-curable resin, 2 to 6 parts of a photoinitiator, 5 to 15 parts of a functional monomer, and 0.5 to 1.5 parts of the multifunctional silicone leveling agent described in this application.

[0028] According to this application, the coating or ink composition utilizes the acetylenic diol structure in the leveling agent to reduce the dynamic surface tension of the system, suppressing bubble formation under construction shear force. Simultaneously, the siloxane backbone provides a smooth feel and scratch resistance. After curing, eugenol functional groups are anchored on the coating surface, interacting with bacterial cell walls through their phenolic hydroxyl structures to provide broad-spectrum antibacterial properties.

[0029] Fourthly, this application provides the application of antibacterial silicone leveling agents in the preparation of antibacterial coatings, wherein a coating containing the leveling agent is applied to the surface of a metal, wood, plastic or glass substrate and cured to form a surface layer with antibacterial activity.

[0030] Preferably, the substrate includes metal, wood, plastic, or glass. The coating thickness is controlled between 10 and 100 micrometers.

[0031] Preferably, the antibacterial properties were evaluated using the GB / T 21866-2008 standard. Experimental results showed that the coating containing the leveling agent of this application exhibited antibacterial rates of 95% to 99.9% against Staphylococcus aureus and Escherichia coli.

[0032] Preferably, the leveling performance of the coating is evaluated by measuring the RIQ (Reflection Image Quality) value. Experimental data show that in water-based wood coating systems, the RIQ value of the coating with the leveling agent of this application is distributed between 70 and 85, and the coating surface is free of pinholes and haze.

[0033] Preferably, the defoaming performance is evaluated through a shaking test. An aqueous solution containing 0.1% leveling agent is shaken at 500 rpm for 10 minutes, and the foam height is observed. The experimental results show that the foam height is maintained between 2.0 and 4.0 cm, and the defoaming rate reaches over 90% within 2 minutes after shaking stops.

[0034] The technical solution provided in this application integrates multiple functional groups into a single polysiloxane molecule through precise molecular structure design. The acetylenic diol block in structure P synergistically interacts with the polysiloxane backbone, enhancing dynamic antifoaming capabilities while providing static leveling. The introduction of structure T increases the product's bio-based content, utilizing the natural antibacterial properties of eugenol to overcome the technical bottlenecks of traditional antibacterial agents, such as easy loss and poor compatibility, through chemical bonding. This leveling agent exhibits stable solubility and surface activity in water-based, solvent-based, and UV systems, reducing the risk of failure associated with the compounding of multiple additives in coating formulations.

[0035] Through the implementation of the above-mentioned technical means, this application has successfully constructed an organosilicon additive that combines efficient leveling, dynamic defoaming, and long-lasting antibacterial functions. The specific ratio of side chains in its molecular structure ensures the directional arrangement of functional groups on the coating surface, solving the problems of single function, poor environmental performance, and stability caused by physical addition in the prior art.

[0036] The leveling agent preparation process described in this application does not involve the use of high-VOC solvents, and the product has a high bio-based content, which aligns with the development trend of green chemistry. In actual production, by controlling the parameters of the stepwise hydrosilylation reaction, the hydrophilicity / hydrophobicity and antibacterial strength of the leveling agent can be precisely controlled, enabling it to adapt to various application environments, from high-polarity water-based paints to low-polarity UV inks. Specific advantages are as follows: Functional Integration: Through ingenious molecular design, a polysiloxane backbone providing leveling / slipping properties, acetylation diol blocks providing wetting / compatibility, and eugenol and its derivatives providing long-lasting antibacterial functions are stably chemically bonded into a single molecule. A single product can replace multiple traditional additives, fundamentally eliminating interference between additives and simplifying formulation and manufacturing processes.

[0037] Excellent environmental performance: The leveling agent itself has extremely low VOC content. More importantly, its key linker—eugenol compounds—is derived from renewable plant resources, resulting in a significantly higher bio-based content in the final product compared to traditional petroleum-based products, thus meeting the requirements of sustainable development.

[0038] Synergistic performance enhancement: The structure of acetylenic diol itself has defoaming and wetting properties, which synergize with the defoaming properties of polysiloxane, enhancing dynamic defoaming ability. Eugenol is fixed to the molecular chain by chemical bonds, avoiding the disadvantages of easy migration and short-lasting effect of physically added antibacterial agents, and providing long-lasting and safe antibacterial properties.

[0039] With wide applications and good compatibility: Its unique comb-like structure and designable polyether segments enable it to exhibit excellent compatibility in water-based, solvent-based, and UV-cured systems with varying polarities, making it less prone to defects such as pinholes and haze, and suitable for a variety of high-end applications.

[0040] In summary, the method and product provided in this application represent a significant technological advancement in the field of chemical additives. Through the integrated design of chemical structures, it simplifies the formulation design difficulty for downstream coating companies and improves the overall protective performance and appearance quality of coatings. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the molecular structure of the hydrogen-containing polysiloxane used in Example 1 of the present invention.

[0042] Figure 2This is a schematic diagram of the first step synthesis route of the multifunctional organosilicon leveling agent described in this invention.

[0043] Figure 3 This is a schematic diagram of the second-step synthesis route of the multifunctional organosilicon leveling agent described in this invention.

[0044] Figure 4 This is a schematic diagram of the third step synthesis route of the multifunctional organosilicon leveling agent described in this invention. Detailed Implementation

[0045] The various embodiments or implementation schemes in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments.

[0046] See Figures 1-4 This application provides an antibacterial silicone leveling agent, which is a comb-shaped polysiloxane. In the comb-shaped polysiloxane structure, the specific parameters are defined as follows: a is a number from 1 to 15; b is a number from 1 to 10, and b is less than or equal to a, while a is less than or equal to 1.5b. 1 It is a C1 to C6 alkyl or phenyl group, wherein the methyl group is in the R group. 1 The proportion of R in the total number of groups is not less than 75%. 2 and R 3 The side chain of the comb-like structure is selected from at least one of structure P or structure T. Structure P is a block formed by a hydrosilylation reaction of an acetylenic diol compound; structure T is an antibacterial functional group formed by a hydrosilylation reaction of eugenol and its derivatives from biological sources.

[0047] In the general formula of the comb-like polysiloxane, the ratio of a to b has a regulatory effect on the physicochemical properties of the leveling agent. When a is controlled between 1 and 15, b is controlled between 1 and 10, and the ratio of a to b is between 1 and 1.5, the length of the polysiloxane backbone and the distribution density of the side chains are within a specific range. This chain segment distribution gives the molecules a specific hydrodynamic volume in the coating system, affecting the solubility of the additives in the solvent and their arrangement at the interface. If the value of a exceeds 15, the siloxane backbone is too long, which will cause the dispersion state of the additives in the aqueous system to shift; if the value of b is too large, the side chain density is too high, and steric hindrance will affect the effective exposure space of the eugenol antibacterial groups.

[0048] Regarding the detailed definition of structure T, the propenyl group in the eugenol structure is attached to the silicon repeating unit via a hydrosilylation reaction, and the substituent R on its benzene ring... 4 Selected from hydrogen, C1 to C12 alkyl, aryl, glycosidic, terpene, or steroidal fragments. In specific applications, R 4 It is a hydrogen or water-soluble monosaccharide group. When R 4When the group is a water-soluble monosaccharide, structure T regulates the hydrophilic equilibrium of the leveling agent in the aqueous system through the polyhydroxy structure of the sugar ring. The methoxy and phenolic hydroxyl groups in the eugenol molecule are polar, while the benzene ring structure is hydrophobic. This structural feature allows structure T to guide the migration of siloxane molecules to the surface.

[0049] A detailed definition of structure P is that it is an alkenylsilane group formed by the hydroaddition of a symmetrical acetylenic diol derivative with silylation. Wherein R... 5 and R 6 Independently selected from hydrogen or polyether segments containing polyoxyethylene (EO) and polyoxypropylene (PO) groups. The polyether segments are terminally capped with hydroxyl or acetyl groups. R 5 and R 6 The molar ratio of EO to PO segments was controlled between 1:0.5 and 1:2. Due to the rigidity of the central carbon-carbon triple bond and the symmetrical alkyl side chains, the alkynyl diol structure can influence the surface pressure balance of the bubble-liquid film. This can be achieved by adjusting R... 5 and R 6 The ratio of EO to PO can be used to fine-tune the hydrophilic-lipophilic balance of the leveling agent.

[0050] In the comb-like polysiloxane, the side chains are distributed in a specific molar ratio. The side chains R located at the ends... 2 In, R containing structure P 2 With R containing structure T 2 The molar ratio is 0.05:1 to 0.2:1. The side chain R located in the intermediate chain segment... 3 In, R containing structure P 3 With R containing structure T 3 The molar ratio is 1:0.05 to 1:0.5. By configuring the leveling agent in this ratio, the antibacterial groups and wetting groups form a specific arrangement sequence in the horizontal and vertical directions when the leveling agent is oriented on the coating surface.

[0051] This application provides a method for preparing the aforementioned multifunctional organosilicon leveling agent, comprising the following specific steps: S10: Provides a hydrogen-containing polysiloxane. The molecular structure of the hydrogen-containing polysiloxane contains terminal hydrogen (Si-H) and side hydrogen (Si-H). This hydrogen-containing polysiloxane is prepared by an equilibrium reaction of octamethylcyclotetrasiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, and tetramethyldisiloxane in the presence of an acidic catalyst. The acidic catalyst is selected from acidic clay or macroporous strong acidic cation exchange resin, and its amount is 1% to 5% of the total mass of the reactants. The equilibrium reaction temperature is 70 to 90°C, and the reaction time is 8 to 12 hours.

[0052] S20: Under inert gas protection and in the presence of a platinum catalyst, the reaction system temperature was controlled at 70 to 100 °C. Eugenol compounds were first added to the system. Due to the difference in reactivity between terminal and side hydrogens, the terminal hydrogen preferentially underwent a hydrosilylation reaction with the allyl group of the eugenol compound. The reaction time was controlled at 1 to 2 hours, and the reaction was monitored by infrared spectroscopy at 2160 cm⁻¹. -1 The change in the Si-H signal at the end group yielded a siloxane intermediate containing an antibacterial group.

[0053] S30: To maintain the activity of the platinum catalyst, raise the reaction system temperature to 90 to 110°C. Add an acetylenic diol compound dropwise to the intermediate, allowing the remaining side hydrogen atoms to undergo a hydrosilylation reaction with the unsaturated bonds in the acetylenic diol compound. The reaction time is 4 to 8 hours.

[0054] S40: The Si-H characteristic absorption peak in the system is detected by infrared spectroscopy. The reaction is stopped when the peak disappears or becomes stable. After the reaction is complete, the system is cooled to room temperature and filtered through a 0.5 to 2 micrometer filter to remove trace amounts of platinum and impurities from the reaction system.

[0055] In steps S20 and S30, the platinum catalyst is selected from an isopropanol solution of chloroplatinic acid, an ethanol solution of chloroplatinic acid, or a Karstedt catalyst. The amount of platinum catalyst added, based on the mass of platinum metal, is 10 to 50 ppm of the total mass of the reactants. The eugenol compound used in step S20 is selected from at least one of eugenol, eugenol methyl ether, and acetyleugenol. The purity of the eugenol compound is not less than 98%, and the water content is less than 500 ppm. The acetylenic diol compound used in step S30 is selected from 2,4,7,9-tetramethyl-5-decyn-4,7-diol, 1,4-butynediol, and their polyoxyethylene / polyoxypropylene etherification products. The molecular weight distribution of the etherification products is between 150 and 800.

[0056] In terms of the preparation process, the terminal hydrogen-preferential reaction technology in step S20 is the core process feature of this application. The terminal Si-H bonds in the hydrogen-containing silicone oil have lower steric hindrance, resulting in higher reactivity than the Si-H bonds on the side chains. By first adding eugenol compounds at a lower temperature (70 to 100°C), the antibacterial groups can be precisely bonded to both ends of the molecular chain. Subsequently, acetylenic diol compounds are introduced at a higher temperature (90 to 110°C) to occupy the side chain positions. This ordered molecular construction method allows the antibacterial groups at both ends of the molecular chain to be distributed like "anchors" at the coating interface during application, while the wetting and defoaming side chains in the middle are spread out on the surface, forming a functionally complementary molecular array.

[0057] The amount of platinum catalyst is controlled between 10 and 50 ppm to balance the reaction rate and product color. Too high a platinum content will cause the reaction to be too fast, resulting in local overheating, which will cause cross-linking of polysiloxane chains or oxidation and discoloration of eugenol; too low a platinum content will not be able to induce the sterically hindered unsaturated bonds in acetylenic diol compounds to react fully, resulting in residual Si-H bonds in the product, which will affect storage stability.

[0058] This application also provides a coating or ink composition containing a multifunctional silicone leveling agent prepared by the above method. In some embodiments, the multifunctional silicone leveling agent accounts for 0.5% to 2.0% by mass in the coating or ink composition. The composition can be a water-based industrial coating, the formulation of which includes: 40 to 60 parts of film-forming resin, 10 to 30 parts of pigments and fillers, 15 to 30 parts of deionized water, 2 to 8 parts of film-forming aid, 0.1 to 0.5 parts of neutralizing agent, and 0.5 to 2.0 parts of the multifunctional silicone leveling agent. The composition can also be a UV-curable ink, the formulation of which includes: 80 to 95 parts of UV-curable resin, 2 to 6 parts of photoinitiator, 5 to 15 parts of functional monomer, and 0.5 to 1.5 parts of the multifunctional silicone leveling agent.

[0059] The technical solution of this application will be described in detail below with reference to specific embodiments.

[0060] Example 1: Synthesis of hydrogen-containing polysiloxanes raw material: Octamethylcyclotetrasiloxane (D4): 192.2g 1,3,5,7-Tetramethylcyclotetrasiloxane (D4H hydrogen content ~1.58 wt%): 109.4 g Tetramethyldisiloxane (M'M'): 98.4g Acid clay: 4g step: D4, D4H, M'M' and acidic clay were added to a 500mL four-necked flask equipped with a condenser, thermometer and nitrogen inlet tube. Stirring was started and the temperature was raised to 80℃. After reaching the reaction temperature, the reaction was carried out for 10 hours. After the reaction was completed, the mixture was filtered to obtain a hydrogen-containing silicone oil with a number average molecular weight of 463 and a viscosity of 2.8 cSt (a=3, b=2).

[0061] Example 2: Synthesis of antibacterial organosilicon leveling agent Hydrogen-containing polysiloxane obtained in Example 1: 100g Butynediol ethoxylate (BEO, molecular weight 174): 100g Eugenol: 71g 0.18g of chloroplatinic acid in ethanol (Pt content 15000 ppm). step: Hydrogen-containing polysiloxane and eugenol were added to a 500 mL four-necked flask equipped with a thermometer and a nitrogen inlet tube. Stirring was started and the temperature was raised to 70 °C, followed by the addition of chloroplatinic acid and a reaction time of 30 min. Then, BEO was added to the system, and the temperature was raised back to 100 °C and maintained for 4 hours. The characteristic absorption peak of Si-H (2160 cm⁻¹) was monitored by infrared spectroscopy. -1 The ions basically disappear. A reddish-brown viscous liquid is obtained, which is the target product S1.

[0062] Example 3: Synthesis of antibacterial silicone leveling agent The results were essentially the same as in Example 2, except that the acetylenic diol compound was 82g of butynediol propoxylate (BMP), and the product obtained was S2.

[0063] Example 4: Synthesis of antibacterial organosilicon leveling agent The result is basically the same as in Example 2, except that the acetylenic diol compound is butynediol: 50g, and the product obtained is S3.

[0064] Example 5: Synthesis of antibacterial silicone leveling agent The results were essentially the same as in Example 2, except that the acetylide diol compound was 1,4-diacetoxy-2-butyne: 100g, and the product obtained was S4.

[0065] Example 6: Synthesis of Antibacterial Organosilicon Leveling Agent The product is basically the same as in Example 2, except that eugenol is replaced with eugenol methyl ether: 77g, and the resulting product is S5.

[0066] Comparative Example 1: Ordinary polyether modified silicone oil Comparative sample C1 was prepared by replacing the eugenol and butynediol compounds in Example 2 with conventional allyl polyoxyethylene ether (molecular weight ~600, EO / PO=4:1) and other conditions were the same as in Example 2.

[0067] Comparative Example 2: Polyether-modified silicone oil Comparative sample C2 was prepared by replacing eugenol in Example 1 with conventional allyl polyoxyethylene ether (molecular weight ~600, EO / PO=4:1) and keeping other conditions the same as in Example 1.

[0068] Performance testing experiment The leveling agent prepared according to this invention and the comparative product were added to the following basic formulations for testing.

[0069] Application Test 1: Performance Test in Aqueous Solutions Prepare a 0.1% deionized aqueous solution of the wetting agent to be tested. Compare the transparency of the aqueous solution of the sample, test the static surface tension of the aqueous solution, and weigh 50g of the aqueous solution into a 200ml transparent bottle. Shake at 500r / min for 10min and compare the foam height and defoaming rate of the sample.

[0070] Application Test 2: Two-component water-based wood coatings Add the following components sequentially while stirring at 1500 rpm: hydroxypropyl emulsion, hydroxypropyl dispersion, neutralizer DMEA, defoamer TEGO-810, dispersant BYK190, blue paste, polyurethane thickener, film-forming aid DPM, deionized water, and leveling agent to be tested (S1-S5 or C1-C2). Maintain this stirring speed for 20 minutes. Seal and let the prepared slurry stand at room temperature for 12 hours to allow all air bubbles in the coating to disappear completely.

[0071] Clean the surface of a 150*70*0.28mm tinplate (ensuring it is free of oil and water stains). Add the water-based isocyanate curing agent to the above-mentioned slurry after it has been left to stand, and stir at 50 rpm for 2 minutes. Apply the prepared coating evenly to the tinplate using an 80-micron wire rod, and cure at room temperature for 24 hours.

[0072] Table 1. Coating component data for this embodiment. Application Test 3: UV Curable Ink Accurately weigh the UV polyurethane resin, photoinitiator 819, photoinitiator 651, TEGO2500, and the leveling agent to be tested (S1-S5 or C1-C2) into a sample container, then add glass beads, seal, and shake for 30 minutes. Use an 80-micron wire rod to evenly coat the prepared coating onto a cardboard plate, then irradiate under a 360nm UV lamp for 10 seconds. After irradiation, cure at room temperature for 24 hours.

[0073] Table 2. Coating component data for this embodiment. Application Test 4: Single-component pure acrylic pore-shrinking paint Titanium dioxide, dispersant BYK-190, and deionized water were added sequentially while stirring at 1200 rpm for 20 minutes to obtain titanium dioxide slurry. Then, the titanium dioxide slurry was added to pure acrylic emulsion, and stirring was maintained at 100 rpm. Next, neutralizer DMEA, defoamer BYK-024, dispersant BYK190, polyurethane thickener, film-forming aid DPM, deionized water, and the leveling agent to be tested (S1-S5 or C1-C2) were added sequentially, maintaining the same stirring speed for 20 minutes. The prepared slurry was then sealed and allowed to stand at room temperature for 12 hours to allow all air bubbles in the coating to disappear completely.

[0074] Clean the surface of a 150*70*0.28mm tinplate (ensuring it is free of oil and water stains). Apply the prepared coating evenly to the tinplate using an 80-micron wire rod and cure at room temperature for 24 hours.

[0075] Table 3. Coating component data for this embodiment. Blank Test 1: Two-component water-based wood coating Add hydroxypropyl emulsion, hydroxypropyl dispersion, neutralizer DMEA, defoamer BYK-024, dispersant BYK190, blue paste, polyurethane thickener, film-forming aid DPM, and deionized water sequentially while stirring at 1500 rpm. Maintain this stirring speed for 20 minutes. Seal and let the prepared slurry stand at room temperature for 12 hours to allow all air bubbles in the coating to disappear completely.

[0076] Clean the surface of a 150*70*0.28mm tinplate (ensuring it is free of oil and water stains). Add the water-based isocyanate curing agent to the above-mentioned slurry after it has been left to stand, and stir at 50 rpm for 2 minutes. Apply the prepared coating evenly to the tinplate using an 80-micron wire rod, and cure at room temperature for 24 hours.

[0077] Table 4. Coating component data for this embodiment Blank Test 2: UV Curable Ink Accurately weigh UV polyurethane resin, photoinitiator 819, photoinitiator 651, and TEGO 2500 into a sample container, then add glass beads, seal, and shake for 30 minutes. Use an 80-micron wire rod to evenly coat the prepared coating onto a cardboard, then irradiate it under a 360nm UV lamp for 10 seconds, and cure it at room temperature for 24 hours after irradiation.

[0078] Table 5. Coating component data for this embodiment. Blank Test 3: Single-component pure acrylic pore-shrinking paint Titanium dioxide, dispersant BYK-190, and deionized water were added sequentially while stirring at 1200 rpm for 20 minutes to obtain titanium dioxide slurry. This titanium dioxide slurry was then added to pure acrylic emulsion, and stirred at 100 rpm. Next, neutralizer DMEA, defoamer BYK-024, dispersant BYK190, polyurethane thickener, film-forming aid DPM, and deionized water were added sequentially, and stirred at the same speed for 20 minutes. The prepared slurry was then sealed and allowed to stand at room temperature for 12 hours to allow all air bubbles in the coating to disappear completely.

[0079] Clean the surface of a 150*70*0.28mm tinplate (ensuring it is free of oil and water stains). Apply the prepared coating evenly to the tinplate using an 80-micron wire rod and cure at room temperature for 24 hours.

[0080] Table 6. Coating component data for this embodiment. Performance testing: The S1-S4 and C1-C2 prepared above were used for aqueous solution performance testing. The test results are shown in Table 7 below.

[0081] Table 7 Performance Tests of Aqueous Solutions S1-S4 and C1-C2 Performance testing: The S1-S4 and C1-C2 obtained above were used in two-component water-based wood coatings, and the test results are shown in Table 8 below.

[0082] Table 8. Test results of S1-S4 and C1-C2 in two-component waterborne wood coatings Performance testing: The S1-S4 and C1-C2 obtained above were used in UV-curable inks, and the test results are shown in Table 9 below.

[0083] Table 9. Test results of S1-S4 and C1-C2 in UV-curable inks Performance testing: The S1-S4 and C1-C2 obtained above were used in a single-component pure acrylic pore-shrinking paint. The test results are shown in Table 10 below.

[0084] Table 10 Test results of S1-S4 and C1-C2 in single-component pure acrylic pore-reducing paint Based on the above performance test results, S1-S4, as a novel antibacterial leveling agent, exhibited the following outstanding characteristics in multiple performance tests: Highly efficient antibacterial: Antibacterial rates exceeded 95% in various coating systems, significantly superior to traditional polyether silicone oil leveling agents. Excellent leveling and antifoaming properties: Effectively controls cratering and improves coating smoothness, while also possessing rapid defoaming capabilities. Strong system adaptability: Stable performance in various systems such as water-based wood coatings, UV inks, and pure acrylic coatings, demonstrating comprehensive functionality. Multifunctional integration: While providing excellent leveling effects, it also possesses long-lasting antibacterial properties, making it suitable for coating applications with high requirements for hygiene and appearance.

[0085] In summary, the S1-S4 series products not only possess the spreading and smoothing functions of traditional leveling agents, but also achieve functional integration by introducing an antibacterial structure, demonstrating significant technological advancement and application promotion value.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations 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 scope of the present invention.

Claims

1. An antibacterial organosilicon leveling agent, characterized in that, include: The leveling agent is a comb-shaped polysiloxane of the general formula shown, and the general formula of the comb-shaped polysiloxane is: ； in: a is a number from 1 to 15; b is a number from 1 to 10, satisfying b ≤ a ≤ 1.5b; R 1 It is a C1-C6 alkyl or phenyl group, wherein the methyl group is in the R group. 1 The proportion of the total number of functional groups shall not be less than 75%; R 2 R 3 For the side chains of the comb-like structure, at least one of structure P and structure T is: The structure P is a block formed by the hydrosilylation reaction of an alkynyl diol compound. The structure T is an antibacterial functional group formed by the hydrosilylation reaction of eugenol and its derivatives derived from biological sources.

2. The antibacterial organosilicon leveling agent according to claim 1, characterized in that, The general formula for the structure T is as follows: Among them, substituent R 4 It is hydrogen, alkyl, aryl, or a functional fragment, wherein the functional fragment is a sugar, terpene, or steroid.

3. The antibacterial silicone leveling agent according to claim 1, characterized in that, The structure P is defined by the following general formula: Where: R 5 R 6 It is a hydrogen or a polyether containing polyoxyethylene and polyoxypropylene groups, wherein the polyether is terminally capped with hydroxyl or acetyl groups.

4. The antibacterial silicone leveling agent according to claim 1, characterized in that, In the polysiloxane with the structure P, R 2 With R containing structure T 2 The molar ratio is 0.05:1 to 0.2:1, and R contains structure P. 3 Side chains and R containing structure T 3 The molar ratio of the side chains is 1:0.05 to 1:0.

5.

5. A method for preparing an antibacterial organosilicon leveling agent as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S10: Provides a hydrogen-containing polysiloxane, wherein the molecular structure of the hydrogen-containing polysiloxane contains terminal hydrogen and side hydrogen; S20: Under the protection of an inert gas and in the presence of a platinum catalyst, the temperature of the reaction system is controlled at 70 to 100°C. Eugenol compounds are first added to the system to allow the terminal hydrogen in the hydrogen-containing polysiloxane to undergo a hydrosilylation reaction with the allyl group of the eugenol compound. The reaction time is 1 to 2 hours to obtain a siloxane intermediate containing antibacterial groups. S30: To maintain the activity of the platinum catalyst, the temperature of the reaction system is raised to 90 to 110°C, and an acetylenic diol compound is added dropwise to the intermediate, so that the remaining side hydrogens undergo a hydrosilylation reaction with the unsaturated bonds in the acetylenic diol compound, and the reaction time is 4 to 8 hours. S40: Detection system at 2160cm using infrared spectroscopy. -1 The Si-H characteristic absorption peak was detected at the site. When the peak disappeared, the reaction was stopped, cooled to room temperature, and filtered to obtain an antibacterial organosilicon leveling agent.

6. The method for preparing the antibacterial organosilicon leveling agent according to claim 5, characterized in that, In step S10, the raw materials for synthesizing hydrogen-containing polysiloxane include: 150 to 250 parts of octamethylcyclotetrasiloxane, 80 to 120 parts of 1,3,5,7-tetramethylcyclotetrasiloxane, and 70 to 110 parts of tetramethyldisiloxane; acidic clay or macroporous strong acidic cation exchange resin is used as a catalyst, and the equilibrium reaction is carried out at 70 to 90°C for 8 to 12 hours.

7. The method for preparing the antibacterial organosilicon leveling agent according to claim 5, characterized in that, In steps S20 and S30, the platinum catalyst is selected from isopropanol solution of chloroplatinic acid, ethanol solution of chloroplatinic acid, or caster catalyst; the amount of platinum catalyst added is 10 to 50 ppm of the total mass of the reactants, based on the mass of platinum metal.

8. The method for preparing the antibacterial organosilicon leveling agent according to claim 5, characterized in that, The eugenol compound used in step S20 is selected from at least one of eugenol, eugenol methyl ether, and acetyleugenol; the alkynyldiol compound used in step S30 is selected from 2,4,7,9-tetramethyl-5-decyn-4,7-diol, 1,4-butynyldiol and their polyoxyethylene / polyoxypropylene etherification products, wherein the molecular weight of the etherification product is 150 to 800.

9. A coating or ink composition, characterized in that, The composition contains the antibacterial silicone leveling agent according to any one of claims 1 to 4, wherein the antibacterial silicone leveling agent is present in the composition at a mass percentage of 0.5% to 2.0%.

10. The application of the antibacterial organosilicon leveling agent according to any one of claims 1 to 4 in the preparation of antibacterial coatings, characterized in that, The coating containing the leveling agent is applied to the surface of a metal, wood, plastic or glass substrate and cured to form a surface layer with antibacterial activity.

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