A high-adhesion silicone resin antibacterial and anticorrosive coating and its preparation method

Abstract

The present invention belongs to the field of intelligent organosilicon polymer materials, and provides a kind of high-adhesion silicone resin antibacterial, anticorrosive coating and preparation method thereof.By organosilane modified natural antibacterial agent dehydroabietic acid, it is introduced into silicone resin system, and the antibacterial performance of silicone resin coating is improved.Using 3-aminopropyl triethoxysilane (KH-550) and γ-glycidyl ether oxygen propyl trimethoxysilane (KH-560) as raw materials, multifunctional siloxane (MF-S) is synthesized, as epoxy-amine curing agent, by condensation reaction, the cross-linking density of methylphenyl silicone resin is increased, so that it has excellent mechanical properties.After the obtained coating is cured at room temperature, the hardness reaches more than 6H, the adhesion reaches 1 grade, and the tensile strength of the obtained film reaches 9MPa.The silicone resin coating prepared by the present invention has good antibacterial performance, antifouling performance and anticorrosive performance, and the preparation method is simple and efficient, strong in practicality, has broad application prospects, and is conducive to realizing industrialized production.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent organosilicon polymer materials, and in particular relates to a high-adhesion silicone resin antibacterial and anticorrosive coating and a preparation method thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Silicone resins are a class of highly cross-linked polysiloxanes with a three-dimensional network structure. Due to their excellent heat resistance, insulation properties, low dielectric constant, and high carbon yield, they have been used as high-temperature-resistant coatings, low-dielectric materials, ablative materials, thermal protection materials, and insulation materials. Furthermore, their low surface energy and modulus can weaken the adhesion of fouling organisms, leading to their widespread application in antifouling and anticorrosion coatings for ships. However, their low strength, poor mechanical properties, susceptibility to external damage, and low adhesion to substrates limit their application.

[0004] Existing methods for improving the mechanical properties of silicone resins often involve adding other functional resins and inorganic fillers. For example, patent CN 117363218 A discloses a method for preparing and applying a transparent silicone coating. This method utilizes a mixture of silicone-modified hydroxyl acrylic resin, polyester resin, isocyanate curing agent, and filler to produce a silicone-modified hydroxyl acrylic resin coating. This coating is then mixed with a self-made silicone resin to produce a transparent silicone coating with excellent adhesion and high hardness. However, the structure and composition of the silicone resin prepolymer depend on the curing reaction and the desired product properties. Silicone resins can be cross-linked and cured through condensation reactions, organic peroxide-initiated reactions, platinum-catalyzed addition reactions, grafting or copolymerization with other active silicone materials, or curing through a cross-linking curing reaction. For example, patent CN 115141486 A discloses a method for preparing a toughened, high-temperature-resistant silicone resin and a toughened, high-temperature-resistant silicone resin. The method uses a photopolymerization method to prepare a silane coupling agent polymer with photoreactive groups. This polymer serves as a toughening phase for a pendant methoxysiloxane. After room-temperature curing, the resulting toughened, high-temperature-resistant silicone resin exhibits excellent heat resistance and toughness. Therefore, preparing a cross-linked silicone resin can enhance its compactness and improve the mechanical strength and mechanical properties of the coating.

[0005] In order to further realize the wide applicability of the coating, functional monomers can be introduced through chemical reactions to achieve the desired performance. For example, rosin is a renewable natural resource that is abundant in my country and has high antibacterial activity and biocompatibility. The carboxyl group and unsaturated conjugated double bond reactive groups in the rosin molecular structure can be introduced into various groups through a variety of chemical reactions, thereby realizing the modification of rosin and further synthesizing high-value-added polymer materials with different performance and varieties. For example, the invention patent CN 116376005 A discloses a method for preparing a rosin-based water-based resin, and compounding it with a wetting agent as a film-forming agent, which has good compatibility, provides good protection for glass fibers in the glass fiber preparation process, reduces the amount of wool yarn, and significantly improves the smoothness and bundling of glass fiber bundles.

[0006] The paper "Synthesis, Characterization and Antibacterial Activity of Dehydroabietic Acid Derivatives" discloses a variety of dehydroabietic acid derivatives, but the inventors found that the improvement effect of existing modified dehydroabietic acid on the antibacterial properties of silicone resins still needs to be improved.

[0007] There is an urgent need for methods that can simultaneously improve the adhesion, antibacterial and antiseptic properties of silicone resins. Summary of the Invention

[0008] To address the above-mentioned problems, the present invention provides a high-adhesion silicone resin antibacterial and anticorrosive coating and its preparation method. The present invention uses 3-aminopropyltriethoxysilane (KH-550) and γ-glycidyloxypropyltrimethoxysilane (KH-560) as raw materials to synthesize a multifunctional siloxane (MF-S). As an epoxy-amine curing agent, it can increase the crosslinking density of methylphenyl silicone resin, giving it excellent mechanical properties. Furthermore, the natural antibacterial agent dehydroabietic acid is modified with organosilane and introduced into the silicone resin system, further improving the antibacterial properties of the silicone resin. The preparation method of the present invention is simple, efficient, highly practical, and easy to promote.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] The first aspect of the present invention provides a high-adhesion silicone antibacterial and anticorrosive coating, comprising:

[0011] Mixing methylphenyl silicone resin, silylated dehydroabietic acid and multifunctional siloxane uniformly and reacting to obtain a reaction product;

[0012] The reaction product is coated on a carrier and cured to obtain a high-adhesion silicone resin antibacterial and anticorrosive coating;

[0013] Wherein, the silylated dehydroabietic acid has a structure shown in formula (II):

[0014]

[0015] The present invention uses methylphenyl silicone resin (MPSR) as the main component, uses silylated dehydroabietic acid (DAS) to provide antibacterial properties, and uses multifunctional siloxane (MF-S) as a curing agent to improve the crosslinking density and curing speed of the silicone resin. The high-adhesion silicone resin antibacterial and anticorrosive coating is prepared through the dehydration reaction of silanols.

[0016] In some embodiments, the mass ratio of the methylphenyl silicone resin, silylated dehydroabietic acid, and multifunctional siloxane is 10:0.3-1.0:0.2-0.5.

[0017] In some embodiments, the reaction is carried out at room temperature for 20-30 minutes.

[0018] More specifically, the steps include:

[0019] 10g of methylphenyl silicone resin (MPSR), 0.7g of silylated dehydroabietic acid (DAS) and 0.5g of multifunctional siloxane (MF-S) were added to a conical flask, stirred and reacted for 20min, and then coated on various substrates and cured at room temperature for 24h.

[0020] In some embodiments, the method for preparing silylated dehydroabietic acid comprises:

[0021] Dehydroabietic acid and γ-glycidyloxypropyltrimethoxysilane are mixed evenly, degassed with N2, and reacted in the presence of a catalyst to obtain the product.

[0022] The invention improves the antibacterial property of the silicone resin coating by introducing silylated dehydroabietic acid. As the content of silylated dehydroabietic acid increases, the antibacterial property of the silicone resin coating gradually improves.

[0023] In some embodiments, the catalyst is triethylbenzylammonium chloride. Preferably, the amount of the catalyst added is 0.5-0.7% of the mass of the dehydroabietic acid.

[0024] In some embodiments, the reaction temperature is 105-120°C for 3-8 hours, preferably 110°C.

[0025] In some embodiments, the molar ratio of dehydroabietic acid to γ-glycidyloxypropyltrimethoxysilane is 1:1-1.1, preferably 1:1.

[0026] More specifically, the steps are as follows:

[0027] Dehydroabietic acid and γ-glycidyloxypropyltrimethoxysilane were added in a 1:1 molar ratio into a three-necked flask equipped with a mechanical stirring blade and a condensation system. The mixture was degassed with N2 and heated at 80°C for 30 minutes. The catalyst triethylbenzyl ammonium chloride was added and reacted at 110°C for 4 hours to obtain the product.

[0028] In some embodiments, the multifunctional siloxane has a structure shown in formula (III):

[0029]

[0030] In some embodiments, the preparation method of the multifunctional siloxane (MF-S) comprises the following steps:

[0031] Add 3-aminopropyltriethoxysilane and γ-glycidyloxypropyltrimethoxysilane into a three-necked flask equipped with a mechanical stirring paddle and react at 60-70° C. for 5-8 hours to obtain the product.

[0032] Preferably, the molar ratio of 3-aminopropyltriethoxysilane to γ-glycidoxypropyltrimethoxysilane is 1:2.

[0033] Preferably, the reaction temperature is 60-70°C, most preferably 70°C.

[0034] In the present invention, methylphenyl silicone resin (MPSR) has the structure shown in formula (I):

[0035]

[0036] According to the present invention, the preparation method of the above-mentioned methylphenyl silicone resin (MPSR) comprises the following steps:

[0037] Add methyltriethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, and solvent to a three-necked flask equipped with a mechanical stirring paddle and condensation system and stir at room temperature. Then, evenly mix the catalyst and deionized water and add it dropwise to the above solution at 50-70°C. After stirring for 5-8 hours, adjust the pH of the solution to neutral, let it stand to separate, and remove the lower layer to dry.

[0038] According to the present invention, preferably, the molar ratio of methyltriethoxysilane, phenyltrimethoxysilane and dimethyldimethoxysilane is 1:(0.1-0.5):(0.05-0.4), more preferably 1:0.14:0.13.

[0039] According to the present invention, preferably, the catalyst is hydrochloric acid;

[0040] Preferably, the added amount of the catalyst is 1-1.5% of the total mass of methyltriethoxysilane, phenyltrimethoxysilane and dimethyldimethoxysilane.

[0041] According to the present invention, preferably, the solvent is xylene.

[0042] According to the present invention, preferably, the reaction temperature is 60-70°C, most preferably 65°C.

[0043] According to the present invention, a preferred embodiment of the method for preparing the methylphenyl silicone resin comprises the following steps:

[0044] Methyltriethoxysilane, phenyltrimethoxysilane and dimethyldimethoxysilane are added in a molar ratio of 1:0.14:0.13 into a three-necked flask equipped with a mechanical stirring paddle and a condensation system. The solvent is xylene, and hydrochloric acid is used as a catalyst in an amount of 1.5% of the total mass of the siloxane. Deionized water is added, and the reaction is carried out at 65°C for 6 hours. After adjusting the pH of the solution to neutral, the solution is allowed to stand for stratification, and the lower layer of solution is taken out and dried to obtain the product.

[0045] The second aspect of the present invention provides a high-adhesion silicone antibacterial and anticorrosive coating prepared by the above method.

[0046] The third aspect of the present invention provides the application of the above-mentioned high-adhesion silicone resin antibacterial and anticorrosive coating in the antifouling / anticorrosion field.

[0047] Beneficial effects of the present invention

[0048] (1) The present invention introduces multifunctional siloxane to effectively increase the crosslinking density of silicone resin and enhance the mechanical properties.

[0049] (2) The present invention modifies dehydroabietic acid by silanization to obtain silylated dehydroabietic acid. By introducing Si-OH groups, the dehydroabietic acid can react with the Si-OH groups in the silicone resin system, thereby improving its compatibility with the silicone resin system. This not only simplifies the preparation method but also makes the silicone resin have better antibacterial properties and toughness.

[0050] (3) The high-adhesion silicone resin coating of the present invention can be cured at room temperature and has high mechanical and physical stability.

[0051] (4) The high-adhesion silicone resin antibacterial and anticorrosive coating of the present invention has a simple operation method during the preparation process and is easy to produce on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their description are used to explain the present invention and do not constitute improper limitations on the present invention.

[0053] Figure 1This is a real picture of the antibacterial effect of the silicone resin coatings prepared in Examples 4-7 of the present invention and Comparative Example 1 on Staphylococcus aureus (S. aureus).

[0054] Figure 2 The antibacterial efficiency of the silicone resin coatings prepared in Examples 4-7 of the present invention and Comparative Example 1 against Staphylococcus aureus (S. aureus) is shown.

[0055] Figure 3 is the pencil hardness of the silicone resin coatings prepared in Examples 8-11 of the present invention and Comparative Example 1.

[0056] Figure 4 3 is a stress-strain curve diagram of the silicone resin film prepared in Examples 8-11 of the present invention.

[0057] Figure 5 1 is a graph showing the adhesion test results of the silicone resin coatings prepared in Examples 8-11 of the present invention and Comparative Example 1.

[0058] Figure 6 3. It is the Nyquist plot of the silicone resin coatings prepared in Examples 8-11 of the present invention and Comparative Example 1 after being immersed in a 3.5 wt % NaCl solution for 2 hours.

[0059] Figure 7 3. It is the Bode plot of the silicone resin coatings prepared in Examples 8-11 of the present invention and Comparative Example 1 after being immersed in a 3.5 wt % NaCl solution for 2 hours. DETAILED DESCRIPTION

[0060] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0061] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are intended to explain the present invention rather than to limit it.

[0062] Example 1

[0063] 178.3 g of methyltriethoxysilane, 27.8 g of phenyltrimethoxysilane, and 15.2 g of dimethyldimethoxysilane were added to a three-necked flask equipped with a mechanical stirring paddle and a condensation system, 60 g of xylene was added, mixed evenly, and then 3.4 g of hydrochloric acid and 66 g of deionized water were added. After reacting at 65 ° C for 6 hours, the pH of the solution was adjusted to neutral, and the solution was allowed to stand for stratification. The lower layer of solution was removed and dried to obtain a transparent colorless solution of methylphenyl silicone resin.

[0064] Example 2

[0065] 30 g of dehydroabietic acid and 24 g of γ-glycidyloxypropyltrimethoxysilane were added to a three-necked flask equipped with a mechanical stirring paddle and a condensation system. The mixture was degassed with N2 and heated at 80°C for 30 min. 0.18 g of triethylbenzylammonium chloride was added and the mixture was reacted at 110°C for 4 h to obtain a transparent yellow viscous liquid silanized dehydroabietic acid (DAS).

[0066] Example 3

[0067] 22 g of 3-aminopropyltriethoxysilane (KH-550) and 46 g of γ-glycidyloxypropyltrimethoxysilane (KH-560) were added to a three-necked flask equipped with a mechanical stirring paddle and reacted at 70° C. for 6 h to obtain multifunctional siloxane (MF-S).

[0068] Example 4

[0069] 10 g of methylphenyl silicone resin and 0.3 g of DAS were mixed and stirred for 20 minutes before coating on a glass slide. The coating was cured at room temperature for at least 5 days to ensure complete curing, resulting in a MPSR-3% DAS coating.

[0070] Example 5

[0071] 10 g of methylphenyl silicone resin and 0.5 g of DAS were mixed and stirred for 20 minutes before coating on a glass slide. The coating was cured at room temperature for at least 5 days to ensure complete curing, resulting in a MPSR-5% DAS coating.

[0072] Example 6

[0073] 10 g of methylphenyl silicone resin and 0.7 g of DAS were mixed and stirred for 20 minutes before coating on a glass slide. The coating was cured at room temperature for at least 5 days to ensure complete curing, resulting in an MPSR-7% DAS coating.

[0074] Example 7

[0075] 10 g of methylphenyl silicone resin and 1.0 g of DAS were mixed and stirred for 20 minutes before coating on a glass slide. The coating was cured at room temperature for at least 5 days to ensure complete curing, yielding a MPSR-10% DAS coating.

[0076] Example 8

[0077] 10 g of methylphenyl silicone resin, 0.7 g of DAS and 0.2 g of MF-S were mixed and stirred for 20 minutes and then coated on a carbon steel plate. The coating was cured at room temperature for at least 5 days to ensure complete curing, obtaining MPSR-7% DAS-2 coating.

[0078] Example 9

[0079] 10 g of methylphenyl silicone resin, 0.7 g of DAS and 0.3 g of MF-S were mixed and stirred for 20 minutes and then coated on a carbon steel plate. The coating was cured at room temperature for at least 5 days to ensure complete curing, obtaining an MPSR-7% DAS-3 coating.

[0080] Example 10

[0081] 10 g of methylphenyl silicone resin, 0.7 g of DAS and 0.4 g of MF-S were mixed and stirred for 20 minutes and then coated on a carbon steel plate. The coating was cured at room temperature for at least 5 days to ensure complete curing, obtaining an MPSR-7% DAS-4 coating.

[0082] Example 11

[0083] 10 g of methylphenyl silicone resin, 0.7 g of DAS and 0.5 g of MF-S were mixed and stirred for 20 minutes and then coated on a carbon steel plate. The coating was cured at room temperature for at least 5 days to ensure complete curing, obtaining an MPSR-7% DAS-5 coating.

[0084] Comparative Example 1

[0085] 10 g of methylphenyl silicone resin was coated on a glass slide and a carbon steel plate. The coating was cured at room temperature for at least 5 days to ensure complete curing to obtain an MPSR coating.

[0086] Comparative Example 2

[0087] Compared with Example 10, without adding DAS, the MPSR-4 coating was obtained, with a hardness of 6H, an elongation at break of 5.8%, a tensile strength of 8.1 MPa, an adhesion level of 1, and |Z| 0.01Hz 1.5×10 9 Ω·cm 2 .

[0088] Test Example 1

[0089] In order to evaluate the antibacterial properties of the silicone resin coating, the present invention conducted an antibacterial experiment using Staphylococcus aureus. The silicone resin was coated on a glass slide (2×2 cm 2 ) and solidified at room temperature for 5 days. Antibacterial experiment: LB liquid medium was used to dilute the bacterial solution to 10 8 CFU / mL, put into the culture dish, add the diluted bacterial solution (10mL). Place the culture dish containing the sample and bacterial solution in a constant temperature incubator and incubate at 30℃ for 12h. After the incubation is completed, dilute 10 3The diluted liquid culture sample (10 μL) was evenly scraped onto LB solid culture medium and incubated at 30°C for 48 hours. The number of colonies adhering to different types of polymers was determined by plate count. The number of colonies growing on the solid culture medium was recorded as N1, and the number of colonies in the control group was recorded as N2. The antibacterial efficiency (AE) was calculated according to formula (1):

[0090] AE=(1-N1 / N2)×100% (1)

[0091] like Figure 1 and Figure 2 Shown are images of Staphylococcus aureus (S. aureus) colonies and their antibacterial efficacy on solid culture medium for the coatings prepared in Examples 4-7 and Comparative Example 1. The control group exhibits a large number of bacterial colonies. With increasing DAS content, the colony count gradually decreases, demonstrating that the silicone coating exhibits a certain degree of resistance to S. aureus. The MPSR coating exhibits an antibacterial efficacy of 7% against S. aureus, while the MPSR-7% DAS coating exhibits an antibacterial efficacy exceeding 98%. This evidence demonstrates that silylated dehydroabietic acid imparts excellent antibacterial properties to silicone resins. Furthermore, a comparison of Example 10 and Comparative Example 2 demonstrates that the addition of DAS increases the toughness of the silicone resin.

[0092] Figure 3 The pencil hardness of the coatings prepared in Examples 8-11 and Comparative Example 1 is shown. As the MF-S content increases, the hardness of the coating gradually increases. The pencil hardness of the MPSR coating is 2H, and the hardness of the MPSR-7% DAS-4 coating and the MPSR-7% DAS-5 coating both reach above 6H. Figure 4 The tensile properties of the films prepared in Examples 8-11 are shown, wherein the elongation at break of the MPSR-7% DAS-2 film is 11.2% and the tensile strength is 8.9 MPa, and the elongation at break of the MPSR-7% DAS-5 film is 9% and the tensile strength reaches 9.2 MPa. Figure 5 Figure 1 shows the adhesion test results of the coatings prepared in Examples 8-11 and Comparative Example 1 on carbon steel plates using the cross-hatch method. The MPSR coating exhibited relatively weak adhesion, while the MPSR-7% DAS-2, MPSR-7% DAS-3, MPSR-7% DAS-4, and MPSR-7% DAS-5 coatings all achieved Grade 1 adhesion. This evidence demonstrates that the multiple crosslinking sites provided by the epoxy-amine system increase the crosslink density, significantly enhancing the mechanical strength of the coating.

[0093] The corrosion behavior of the samples was evaluated by AC impedance spectroscopy. The Nyquist and Bode plots of the coatings (180 μm thick) prepared in Examples 8-11 and Comparative Example 1 after immersion in 3.5 wt% NaCl solution for 2 h are shown in Figure 1. Figure 6and Figure 7 As shown. Generally speaking, the diameter of the capacitive reactance arc is proportional to the corrosion resistance. The larger the radius of the capacitive reactance arc, the stronger the corrosion resistance of the coating. The impedance modulus at the lowest frequency (|Z| 0.01Hz ) is proportional to the corrosion resistance. The coatings of Examples 8-11 have |Z| 0.01Hz The value reaches 10 9 Ω·cm 2 above( Figure 7 ), the results show that the coatings prepared in Examples 8-11 have good protective effects on Q235 carbon steel.

[0094] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A high-adhesion silicone antibacterial and anticorrosive coating, characterized in that: include: Mixing methylphenyl silicone resin, silylated dehydroabietic acid and multifunctional siloxane uniformly and reacting to obtain a reaction product; The reaction product is coated on a carrier and cured to obtain a high-adhesion silicone resin antibacterial and anticorrosive coating; Wherein, the silylated dehydroabietic acid has a structure shown in formula (II): Formula (II).

2. The high-adhesion silicone antibacterial and anticorrosive coating according to claim 1, characterized in that: The mass ratio of the methylphenyl silicone resin, silylated dehydroabietic acid and multifunctional siloxane is 10:0.3-1.0:0.2-0.

5.

3. The high-adhesion silicone antibacterial and anticorrosive coating according to claim 1, characterized in that: The reaction conditions are room temperature for 20-30 min.

4. The high-adhesion silicone antibacterial and anticorrosive coating according to claim 1, characterized in that: The preparation method of the silylated dehydroabietic acid comprises: Dehydroabietic acid and γ-glycidyloxypropyltrimethoxysilane are mixed evenly, degassed with N2, and reacted in the presence of a catalyst to obtain the product.

5. The high-adhesion silicone antibacterial and anticorrosive coating according to claim 4, characterized in that: The catalyst is triethylbenzylammonium chloride.

6. The high-adhesion silicone antibacterial and anticorrosive coating according to claim 4, characterized in that: During the preparation of the silylated dehydroabietic acid, the reaction conditions are 105° C.-120° C. for 3-8 hours.

7. The high-adhesion silicone antibacterial and anticorrosive coating according to claim 4, characterized in that: The molar ratio of the dehydroabietic acid to gamma-glycidyloxypropyltrimethoxysilane is 1:1-1.

1.

8. The high-adhesion silicone antibacterial and anticorrosive coating according to claim 1, characterized in that: Multifunctional siloxane having the structure shown in formula (III): Formula (III).

9. Use of the high-adhesion silicone resin antibacterial and anticorrosive coating according to any one of claims 1 to 8 in the field of antifouling or anticorrosion.

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