High-hardness antibacterial coating and preparation method thereof
Through the synergistic effect of multifunctional acrylates and silicone-modified acrylates, combined with the coordination bonding of side chain nitrogen-containing heterocycles with metal ions, a high-hardness antibacterial coating is prepared, which solves the shortcomings of existing coatings in hardness, flexibility, light transmittance and antibacterial properties, and meets the high performance requirements of medical equipment.
Patent Information
- Application Number
- CN202511103083.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-07
- Publication Date
- 2025-10-17
AI Technical Summary
Existing electronic touch screen coatings have insufficient synergistic optimization in terms of hardness, flexibility and optical transmittance, and lack long-term antibacterial function, making it difficult to meet the high hygiene and safety requirements of medical equipment.
The synergistic effect of multifunctional acrylates, chain-extending and cross-linking silicone-modified acrylates is used to prepare high-hardness antibacterial coatings through hydrosilylation and ring-opening polymerization. Nitrogen-containing heterocycles are introduced into the side chains to coordinate and bond with metal ions to form a three-dimensional network structure, thereby enhancing the density and antibacterial properties of the coating.
The coating has high hardness, excellent flexibility, long-lasting antibacterial effect and high light transmittance, meeting the durability and hygiene and safety requirements of medical equipment, and has good wear resistance and resistance to erosion by alcohol detergents.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of coatings for electronic screens, in particular to a high-hardness antibacterial coating and a preparation method thereof. BACKGROUND
[0002] In the field of electronic touch screen protection, especially in the application scenarios of high hygiene and safety requirements such as medical equipment, the synergistic optimization of high hardness, antibacterial property and optical transmittance is a key challenge for coating technology. In the prior art, the mainstream solution of UV-cured coatings mainly improves the hardness through chemical structure design or nano-composite modification, but still has significant defects. For example, the introduction of epoxy groups (such as epoxy acrylate resin) can effectively increase the crosslinking density and hardness of the coating, but the rigid molecular chain easily leads to an increase in curing shrinkage, causing an increase in coating brittleness and a decrease in flexibility, and micro-cracks are easily generated in the scenario of frequent contact with alcohol cleaning agents in medical equipment, affecting the durability. In addition, the absorption characteristics of the epoxy group to ultraviolet light may cause the coating to yellow, reducing the light transmittance and making it difficult to meet the optical requirements of high-resolution touch screens.
[0003] Another technical route relies on the addition of nano-fillers, such as nano-aluminum oxide and fumed silica, to improve the hardness through physical reinforcement effect. However, the high surface energy of nano-particles easily leads to agglomeration, not only reducing the dispersion uniformity, but also leading to a decrease in the light transmittance of the coating. In addition, the rigid filler increases the brittleness of the coating and decreases the flexibility, and the imbalance between rigidity and toughness is not conducive to improving the wear resistance. More importantly, existing high-hardness coatings generally lack long-term antibacterial function, and medical equipment touch screens are often exposed to a bacterial-rich environment, posing a biological safety risk. SUMMARY
[0004] The present application provides a high-hardness antibacterial coating and a preparation method thereof, which can effectively solve the synergistic problem of hardness, flexibility and optical transmittance of the screen protection coating, and realize its antibacterial function.
[0005] In a first aspect, the present application provides a high-hardness antibacterial coating, comprising the following raw materials by mass:
[0006] 40-60 parts of multifunctional acrylate, 5-10 parts of chain-extended organosilicon modified acrylate, 2-5 parts of crosslinking organosilicon modified acrylate, 0.5-1.5 parts of antibacterial agent, 1-2 parts of photoinitiator, 50-80 parts of diluent; the chain-extended organosilicon modified acrylate is prepared by the silicon-hydrogen addition of end-hydrogen silicone oil and diacrylate monomer with a molar ratio of 1:2-2.1; the crosslinking organosilicon modified acrylate is prepared by the ring-opening polymerization of chain-extended organosilicon modified acrylate and tetramethylcyclotetrasiloxane with a molar ratio of 1:2-6 under the action of a cationic catalyst to obtain a side hydrogen-containing intermediate, and then by the silicon-hydrogen addition of diacrylate monomer.
[0007] The present application realizes the balance of coating rigidity, flexibility and chemical resistance through the synergistic effect of multifunctional acrylate, chain-extended and cross-linked silicone-modified acrylate. Multifunctional acrylate as the main framework provides high cross-linking density and hardness, but its rigid segment is easy to cause brittleness. Chain-extended silicone-modified acrylate has a linear flexible long chain structure. In the UV curing process, the long chain silicone segment of the chain-extended monomer gives the coating flexibility, reduces the curing shrinkage stress and relieves the risk of brittle cracking.
[0008] The cross-linked silicone-modified acrylate introduces side chain hydrogen through ring-opening polymerization of tetramethylcyclotetrasiloxane (D4H), and further reacts with diacrylate to form a structure containing acrylate groups in the side chain. Both the side chain and the end group can participate in cross-linking to form a three-dimensional network structure, which not only improves the density and hardness of the coating, but also inhibits the swelling and erosion of the coating by alcohol and cleaning agent through the hydrophobicity and low surface energy of the silicone segment. The coating system avoids the problems of reduced light transmittance or deteriorated flexibility caused by traditional epoxy groups or nano fillers. Under the synergistic effect of the three, the coating hardness and flexibility are balanced, it has good wear resistance, and at the same time has resistance to alcohol and cleaning agent, meeting the use requirements of medical equipment which are frequently cleaned.
[0009] In any of the above technical solutions, the hydrogen content of the end-hydrogen silicone oil is 0.04-0.19.
[0010] The hydrogen content directly affects the efficiency of silicon-hydrogen addition reaction and the structure of the product. When the hydrogen content is too low (<0.04), the reaction activity is insufficient, the synthesis efficiency of the chain-extended monomer is low, and the compatibility with multifunctional monomers is reduced.
[0011] The end-hydrogen silicone oil is a hydrogen-terminated polysiloxane, and its molecular structure is as follows.
[0012]
[0013] The molecular structure of the chain-extended silicone-modified acrylate is as follows, wherein Acrylate is a diacrylate monomer.
[0014]
[0015] The molecular structure of the side-hydrogen intermediate is as follows, wherein Acrylate is a diacrylate monomer, and m = 2-6.
[0016]
[0017] In any of the above technical solutions, the diacrylate monomer is selected from one or more of dipropylene glycol diacrylate, tripropylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, tricyclodecane dimethanol diacrylate and polyethylene glycol diacrylate.
[0018] In any of the above technical solutions, the multi-functional acrylate is a monomer containing at least 3 acrylate functional groups, preferably one or more of trimethylolpropane triacrylate, pentaerythritol triacrylate, 3 (propoxy) glyceryl triacrylate, di (trimethylolpropane) tetraacrylate.
[0019] In any of the above technical solutions, the temperature of the hydrosilylation reaction is 90-120°C, and the amount of platinum catalyst is 10-50 ppm (calculated as Pt) based on the total mass of the vinyl-containing monomer and the vinyl monomer.
[0020] In any of the above technical solutions, the cationic catalyst is a sulfonated cationic resin.
[0021] In any of the above technical solutions, the reaction temperature of the ring-opening polymerization is 80-100°C.
[0022] In any of the above technical solutions, in the preparation of the cross-linked silicone-modified acrylate, the raw materials for the hydrosilylation reaction contain a vinyl-containing nitrogen heterocycle, and the molar ratio of the vinyl-containing nitrogen heterocycle to the diacrylate monomer is 1-2:1-2; the antibacterial agent is a metal ion.
[0023] In any of the above technical solutions, the vinyl-containing nitrogen heterocycle is at least one of vinylpyridine, vinylpyrrolidone, and vinylimidazole.
[0024] In the synthesis of the cross-linked silicone-modified acrylate, a vinyl-containing nitrogen heterocycle is introduced and connected to the side of the molecular chain through a hydrosilylation reaction. The lone pair of electrons of the nitrogen heterocycle can form a stable coordination bond with a metal ion antibacterial agent (such as silver ion), anchoring the antibacterial agent within the coating network and avoiding the ion migration and antibacterial performance decay caused by traditional physical mixing. This coordination not only prolongs the antibacterial time, but also enhances the cross-linking density of the coating through the coordination of the metal ion and the heterocycle, further improving the hardness and solvent resistance.
[0025] At the same time, the non-chemical (coordination) bonding of the nitrogen-containing heterocycle with the metal ion gives the coating certain energy dissipation capacity, which relieves stress concentration through bond rupture and recombination when subjected to external force impact, reduces the flexibility degradation caused by traditional chemical bonding, and is beneficial to maintaining high wear resistance.
[0026] In any of the above technical solutions, the diluent is selected from at least one of ethyl acetate, propylene glycol methyl ether acetate, butyl acetate, acetone, cyclohexanone, toluene, and xylene.
[0027] In any of the above technical solutions, the photoinitiator is selected from at least one of benzoin and its derivatives, phenylethanone compounds, and aromatic ketone compounds.
[0028] In any of the above technical solutions, the metal ion antibacterial agent is at least one of a silver ion antibacterial agent, a copper ion antibacterial agent, or a zinc ion antibacterial agent; preferably a silver ion antibacterial agent.
[0029] In a second aspect, the application provides a preparation method of the high-hardness antibacterial coating, comprising:
[0030] According to the ratio of any of the above coatings, the multifunctional acrylate, the chain-extended organosilicon-modified acrylate, and the cross-linked organosilicon-modified acrylate are uniformly mixed to obtain a premix;
[0031] The antibacterial agent, the photoinitiator, and the diluent are added to the premix, stirred and mixed, and filtered to obtain the antibacterial coating.
[0032] In summary, the application has the following beneficial effects:
[0033] The application constructs a rigid skeleton through a multifunctional acrylate, a cross-linked organosilicon-modified monomer improves the compactness and chemical resistance through three-dimensional cross-linking, and a chain-extended organosilicon-modified monomer provides a flexible segment to balance brittleness. The coordination between the side chain nitrogen heterocycle and the metal ion stabilizes the antibacterial agent and enhances the coating network, balancing long-acting antibacterial and mechanical properties. The hydrophobicity of the organosilicon segment significantly improves the alcohol and cleaner resistance, avoiding the yellowing of traditional epoxy groups or the decrease in light transmittance of nano fillers. In the preparation process, the molecular structure is accurately controlled through hydrosilylation and ring-opening polymerization, ensuring high light transmittance and rapid curing characteristics of the coating. The coating exhibits high hardness (≥4H), excellent flexibility and wear resistance, long-acting antibacterial rate (>99.9%), and high light transmittance in medical device touch screen applications, meeting the stringent durability and hygiene safety requirements. DETAILED DESCRIPTION
[0034] Preparation Example
[0035] Preparation Example 1-1, a chain-extended organosilicon-modified acrylate, is prepared according to the following steps:
[0036] Take 1 mol of hydrogen-terminated silicone oil (hydrogen content 0.11%) and 2 mol of dipropylene glycol diacrylate and add them to a reaction kettle, replace with nitrogen for 3 times, and heat to 100°C. Slowly add 20 ppm of platinum catalyst (Karstedt catalyst, Pt content 2%) dropwise, maintain the temperature at 100°C ± 2°C, and stir for 4 hours. After the reaction is completed, heat to 140°C, and distill under reduced pressure (-0.1 MPa) for 1 hour to remove low molecular weight impurities.
[0037] Preparation Example 1-2, a chain-extended organosilicon-modified acrylate, is prepared according to the following steps:
[0038] Take 1 mol end hydrogen silicone oil (hydrogen content 0.04%) and 2.0 mol tripropylene glycol diacrylate into the reaction kettle, nitrogen replacement 3 times, temperature to 90°C. Slowly drop platinum catalyst (Karstedt catalyst, Pt content 2%) 50 ppm, maintain temperature 95°C ± 2°C, stirring reaction 5 hours. After the reaction, temperature to 130°C, reduced pressure distillation (-0.1 MPa) 1 h, remove low molecular impurities, get.
[0039] Preparation example 1-3, a chain extension type silicone modified acrylate, is prepared according to the following steps:
[0040] Take 1 mol end hydrogen silicone oil (hydrogen content 0.18%) and 2.1 mol, 1,6-hexanediol diacrylate into the reaction kettle, nitrogen replacement 3 times, temperature to 115°C. Slowly drop platinum catalyst (Karstedt catalyst, Pt content 2%) 10 ppm, maintain temperature 115°C ± 2°C, stirring reaction 3 hours. After the reaction, temperature to 140°C, reduced pressure distillation (-0.1 MPa) 1 h, remove low molecular impurities, get.
[0041] Preparation example 2-1, a crosslinking type silicone modified acrylate, is prepared according to the following steps:
[0042] Take 1 mol chain extension type silicone modified acrylate of preparation example 1-1 and 5 mol tetramethylcyclotetrasiloxane mixture, stirring uniformity to get premix. Add 6 wt% of the premix sulfonated cation exchange resin (NKC-9), temperature to 90°C, reaction 6 hours (water control <50 ppm). After the reaction, cool and filter to remove resin catalyst, temperature to 140°C, reduced pressure distillation (-0.1 MPa) 1 h, remove low molecular impurities, add sodium bicarbonate to adjust pH value to neutral, the product is treated with activated carbon for 48 h, then filter to get side hydrogen containing intermediate (m=5).
[0043] Mix the above prepared hydrogen containing intermediate with 3 mol dipropylene glycol diacrylate, 2 mol vinyl pyridine, temperature to 110°C under nitrogen protection; add platinum catalyst 10 ppm, reaction 6 hours. Vacuum reduced pressure distillation (-0.1 MPa, 170°C) to remove unreacted monomer, get hydrophobic modifier.
[0044] Preparation example 2-2, a crosslinking type silicone modified acrylate, is prepared according to the following steps:
[0045] Take 1 mol of chain extension type silicone modified acrylate prepared in Preparation Example 1-2 and 2 mol of tetramethylcyclotetrasiloxane, mix and stir to obtain a premix. Add 5 wt% of sulfonated cation exchange resin (NKC-9) to the premix, heat to 80°C, and react for 5 hours (moisture control < 50 ppm). After the reaction is completed, remove the resin catalyst by cooling and filtering, heat to 130°C, and distill under reduced pressure (-0.1 MPa) for 1 hour to remove low molecular weight impurities. Add sodium bicarbonate to adjust the pH to neutral, treat the product with activated carbon for 48 hours, filter again, and obtain a side hydrogen-containing intermediate (m = 2).
[0046] Mix the side hydrogen-containing intermediate prepared above with 1 mol of dipropylene glycol diacrylate and 1 mol of 1-vinylimidazole, heat to 95°C under nitrogen protection, add 20 ppm of platinum catalyst, and react for 4 hours. Distill under reduced pressure (-0.1 MPa, 160°C) in a vacuum to remove unreacted monomers, and obtain a hydrophobic modifier.
[0047] Preparation Example 2-3, a crosslinking type silicone modified acrylate, is prepared according to the following steps:
[0048] Take 1 mol of chain extension type silicone modified acrylate prepared in Preparation Example 1-3 and 6 mol of tetramethylcyclotetrasiloxane, mix and stir to obtain a premix. Add 10 wt% of sulfonated cation exchange resin (NKC-9) to the premix, heat to 100°C, and react for 5 hours (moisture control < 50 ppm). After the reaction is completed, remove the resin catalyst by cooling and filtering, heat to 130°C, and distill under reduced pressure (-0.1 MPa) for 1.5 hours to remove low molecular weight impurities. Add sodium bicarbonate to adjust the pH to neutral, treat the product with activated carbon for 48 hours, filter again, and obtain a side hydrogen-containing intermediate (m = 6).
[0049] Mix the side hydrogen-containing intermediate prepared above with 4 mol of dipropylene glycol diacrylate and 2 mol of vinylpyrrolidone, heat to 100°C under nitrogen protection, add 20 ppm of platinum catalyst, and react for 5 hours. Distill under reduced pressure (-0.1 MPa, 170°C) in a vacuum to remove unreacted monomers, and obtain a hydrophobic modifier.
[0050] Preparation Example 2-4, a crosslinking type silicone modified acrylate, differs from Preparation Example 2-1 in that the amount of dipropylene glycol diacrylate used in the silicon-hydrogen addition reaction step is 1 mol, and the amount of vinylpyridine used is 4 mol.
[0051] Preparation Example 2-5, a crosslinking type silicone modified acrylate, differs from Preparation Example 2-1 in that the amount of dipropylene glycol diacrylate used in the silicon-hydrogen addition reaction step is 4 mol, and the amount of vinylpyridine used is 1 mol.
[0052] Preparation Example 2-6, a crosslinking type silicone-modified acrylate, differs from Preparation Example 2-1 in that, in the hydrosilylation reaction step, dipropylene glycol diacrylate is used instead of vinylpyridine in an equimolar amount.
[0053] Preparation Example 2-7, a crosslinking type silicone-modified acrylate, differs from Preparation Example 2-1 in that, in the hydrosilylation reaction step, vinylpyridine is used instead of dipropylene glycol diacrylate in an equimolar amount.
[0054] Example
[0055] Example 1, a high-hardness antibacterial coating, is prepared as follows:
[0056] 500 g of trimethylolpropane triacrylate, 72 g of the chain-extended silicone-modified acrylate of Preparation Example 1-1, 38 g of the crosslinking type silicone-modified acrylate of Preparation Example 2-1 are mixed uniformly, and stirred at 500 rpm for 10 min to obtain a premix.
[0057] To the premix, 10 g of silver ion antibacterial agent (Dime DM-Ag06), 15 g of benzophenone, and 350 g of ethyl acetate, 300 g of propylene glycol methyl ether acetate are added, stirred at 500 rpm for 20 min, and filtered through a 400-mesh screen to obtain the antibacterial coating.
[0058] Example 2, a high-hardness antibacterial coating, is prepared as follows:
[0059] 400 g of pentaerythritol triacrylate, 55 g of the chain-extended silicone-modified acrylate of Preparation Example 1-2, 20 g of the crosslinking type silicone-modified acrylate of Preparation Example 2-2 are mixed uniformly, and stirred at 500 rpm for 10 min to obtain a premix.
[0060] To the premix, 5 g of silver ion antibacterial agent (Dime DM-Ag06), 10 g of benzophenone, and 500 g of ethyl acetate are added, stirred at 500 rpm for 20 min, and filtered through a 400-mesh screen to obtain the antibacterial coating.
[0061] Example 3, a high-hardness antibacterial coating, is prepared as follows:
[0062] 600 g of di(trimethylolpropane) tetraacrylate, 100 g of the chain-extended silicone-modified acrylate of Preparation Example 1-3, 45 g of the crosslinking type silicone-modified acrylate of Preparation Example 2-3 are mixed uniformly, and stirred at 500 rpm for 10 min to obtain a premix.
[0063] To the premix, 15 g of MED-500 copper ion antibacterial agent, 20 g of benzoin, and 50 g of cyclohexanone, 30 g of xylene are added, stirred at 500 rpm for 30 min, and filtered through a 400-mesh screen to obtain the antibacterial coating.
[0064] Example 4, a high hardness antibacterial coating, differs from Example 1 in that the crosslinking type silicone-modified acrylate of Preparation Example 2-4 is substituted for the crosslinking type silicone-modified acrylate of Preparation Example 2-1 in equal mass.
[0065] Example 5, a high hardness antibacterial coating, differs from Example 1 in that the crosslinking type silicone-modified acrylate of Preparation Example 2-5 is substituted for the crosslinking type silicone-modified acrylate of Preparation Example 2-1 in equal mass.
[0066] Example 6, a high hardness antibacterial coating, differs from Example 1 in that the crosslinking type silicone-modified acrylate of Preparation Example 2-6 is substituted for the crosslinking type silicone-modified acrylate of Preparation Example 2-1 in equal mass.
[0067] Example 7, a high hardness antibacterial coating, differs from Example 1 in that the silicone quaternary ammonium salt (dimethyloctadecyl [3-(trimethoxysilyl) propyl) is substituted for the silver ion antibacterial agent (Dyma DM-Ag06) in equal mass.
[0068] Example 8, a high hardness antibacterial coating, differs from Example 6 in that the silicone quaternary ammonium salt (dimethyloctadecyl [3-(trimethoxysilyl) propyl) is substituted for the silver ion antibacterial agent (Dyma DM-Ag06) in equal mass.
[0069] Comparative Example
[0070] Comparative Example 1, a high hardness antibacterial coating, differs from Example 8 in that the crosslinking type silicone-modified acrylate of Preparation Example 2-7 is substituted for the crosslinking type silicone-modified acrylate of Preparation Example 2-1 in equal mass.
[0071] Comparative Example 2, a high hardness antibacterial coating, differs from Example 8 in that the crosslinking type silicone-modified acrylate of Preparation Example 2-1 is substituted for the chain extension type silicone-modified acrylate of Preparation Example 1-1 in equal mass.
[0072] Comparative Example 3, a high hardness antibacterial coating, differs from Example 8 in that the chain extension type silicone-modified acrylate of Preparation Example 1-1 is substituted for the crosslinking type silicone-modified acrylate of Preparation Example 2-1 in equal mass.
[0073] Comparative Example 4, a high hardness antibacterial coating, differs from Example 8 in that tripropylene glycol diacrylate is substituted for trimethylolpropane triacrylate in equal mass.
[0074] Performance Test Test
[0075] Test 1: Coating Hardness Test
[0076] Reference Standard: GB / T 6739-2022 "Pencil hardness of paint films by pencil test".
[0077] Test Procedure: The paint was spin-coated on the surface of a polycarbonate plate, and the dry film thickness of the sample after curing (light source: 365-395 nm LED light source, light intensity: 300-500 mW / cm 2 ) was 20±2 μm. According to the standard, a pencil hardness tester was used to apply uniform pressure (750 g) at a 45° angle to the surface of the coating, starting from the softest pencil (6B). Higher hardness pencils were gradually replaced until visible scratches appeared on the surface of the coating. The highest pencil hardness grade without scratching the coating was recorded.
[0078] Test 2: Coating flexibility test
[0079] Reference Standard: ASTM D522-D522M-17 "Standard Test Methods for Sustained (Constant) Load Hardness of Organic Coatings by Reversed-Method".
[0080] Test Procedure: The paint was spin-coated on the surface of a medical-grade PET film (thickness 100 μm), and the dry film thickness of the sample after curing (light source: 365-395 nm LED light source, light intensity: 300-500 mW / cm 2 ) was 15±1 m. Using a cylindrical shaft bender (Elcometer 1540), the sample was bent 180° around a cylindrical shaft of different diameters with the coating facing outward, and the presence of cracks or peeling in the coating was observed. The smallest bending shaft diameter without cracks was recorded.
[0081] Test 3: Coating abrasion resistance test
[0082] Reference Standard: GB / T 1768-2006 "Determination of abrasion resistance of paints and varnishes".
[0083] Test Procedure: The paint was spin-coated on the surface of a polycarbonate plate, and the dry film thickness of the sample after curing (light source: 365-395 nm LED light source, light intensity: 300-500 mW / cm 2 ) was 20±2 μm. According to GB / T 1768-2006, a Cs-10 type rubber grinding wheel was selected, with a weight of 1Kg, and the specified number of revolutions was 2000. Five samples were taken for each group, and the average mass loss of the samples was calculated. The test result was accurate to 0.1 mg.
[0084] Test 4: Coating light transmittance test
[0085] Reference Standard: ASTM D1003-21 "Standard Test Methods for Haze and Luminous Transmittance of Transparent Plastics".
[0086] Test procedure: The coating was spin-coated on the surface of a transparent glass sheet (size 50 x 50 mm), and the dry film thickness of the sample after curing (light source: 365-395 nm LED light source, light intensity 300-500 mW / cm 2 ) was 20 ± 2 μm. The test was performed using a spectrophotometer (HunterLab UltraScan VIS), and the test conditions were: D65 light source, wavelength range 380-780 nm, incident angle 0°, and integrating sphere measurement to determine the light transmittance (%).
[0087] Test 5: Coating resistance to ethanol test
[0088] Test procedure: The coating was spin-coated on the surface of a polycarbonate plate, and the dry film thickness of the sample after curing (light source: 365-395 nm LED light source, light intensity 300-500 mW / cm 2 ) was 20 ± 2 μm. The sample was immersed in a 75% ethanol solution (25 ± 1 °C) for 24 hours. After removal, it was rinsed with water and dried at room temperature for 24 hours. The hardness after immersion was tested according to Test 1, and the hardness retention rate was calculated.
[0089] Table 1, Test results
[0090]
[0091] Analysis of test results:
[0092] 1) Compared with Comparative Examples 1-4, the synergistic combination of multifunctional acrylate, chain-extending type and crosslinking type silicone-modified acrylate in Examples 1-8 achieved a balance between coating rigidity and flexibility, and thus obtained a protective coating with excellent abrasion resistance and chemical resistance (ethanol).
[0093] 2) Compared with Examples 7-8, Examples 1-3 introduced a nitrogen-containing heterocyclic group into the side chain of the crosslinking type silicone-modified acrylate, and cooperated with the metal ion antibacterial agent, which could improve the coating hardness (from 4H to 5H), and did not deteriorate the flexibility of the coating (the minimum bending diameter was maintained at 5 mm).
[0094] Test 6: Antibacterial performance test
[0095] Reference standard: Refer to ISO 22196-2011
[0096] Sample preparation: The coating was coated on a sterile polyester film (50 x 50 mm) to obtain a sheet-shaped sample.
[0097] Bacteriostatic rate test: According to ISO 22196-2011, Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 6538) were inoculated, and the bacterial solution concentration was 1 x 10 5CFU / mL. After the sample was contacted with the bacteria for 24 hours, it was eluted and counted. The inhibition rate was calculated according to the formula: inhibition rate = (bacterial colony count of the blank group - bacterial colony count of the sample group) / bacterial colony count of the blank group x 100%.
[0098] Long-term antibacterial performance test: the sample was soaked in a solution containing 1% detergent, 50 cycles (5 minutes each time), and the inhibition rate test was repeated.
[0099] Table 2, antibacterial performance test results
[0100] Sample Antibacterial rate / % Long-lasting antibacterial rate / % Example 1 99.9 93.5 Example 2 99.9 91.3 Example 3 99.9 94.9 Example 4 99.9 94.4 Example 5 99.9 90.4 Example 6 99.9 89.2 Example 7 99.9 76.2 Example 8 99.9 77.6 Comparative Example 1 99.9 96.2 Comparative Example 2 99.9 95.7 Comparative Example 3 99.9 74.1 Comparative Example 4 99.9 88.3
[0101] The specific embodiments are only an explanation of the present application, which is not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.
Claims
1. A high-hardness antibacterial coating, characterized in that: Including the following raw materials by weight: 40 to 60 parts of multifunctional acrylate, 5 to 10 parts of chain-extending organosilicon-modified acrylate, 2 to 5 parts of cross-linking organosilicon-modified acrylate, 0.5 to 1.5 parts of antibacterial agent, 1 to 2 parts of photoinitiator, and 50 to 80 parts of diluent; the chain-extending organosilicon-modified acrylate is prepared by hydrosilylation of terminal hydrogen silicone oil and diacrylate monomer in a molar ratio of 1:2 to 2.1; the cross-linking organosilicon-modified acrylate is prepared by ring-opening polymerization of chain-extending organosilicon-modified acrylate and tetramethylcyclotetrasiloxane in a molar ratio of 1:2 to 6 in the presence of a cationic catalyst to obtain a side hydrogen-containing intermediate, which is then reacted with diacrylate monomer through hydrosilylation.
2. The high-hardness antibacterial coating according to claim 1, characterized in that: The hydrogen content of the hydrogen-terminated silicone oil is 0.04-0.19%.
3. The high-hardness antibacterial coating according to claim 1, characterized in that: The diacrylate monomer is selected from one or more of dipropylene glycol diacrylate, tripropylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, tricyclodecane dimethanol diacrylate, and polyethylene glycol diacrylate.
4. The high-hardness antibacterial coating according to claim 1, characterized in that: The multifunctional acrylate is selected from one or more of trimethylolpropane triacrylate, pentaerythritol triacrylate, 3 (propoxy) glycerol triacrylate, and di (trimethylolpropane) tetraacrylate.
5. The high-hardness antibacterial coating according to claim 1, characterized in that: The temperature of the hydrosilylation reaction is 90-120° C., and the amount of the platinum catalyst used is 10-50 ppm.
6. The high-hardness antibacterial coating according to claim 1, characterized in that: The reaction temperature of the ring-opening polymerization is 80-100°C.
7. The high-hardness antibacterial coating according to claim 1, characterized in that: In the preparation of the cross-linked organosilicon-modified acrylate, the raw materials for the hydrosilylation reaction include a vinyl nitrogen-containing heterocycle, and the molar ratio of the vinyl nitrogen-containing heterocycle to the diacrylate monomer is 1-2:1-2; and the antibacterial agent is a metal ion.
8. The high-hardness antibacterial coating according to claim 7, characterized in that: The vinyl nitrogen-containing heterocycle is at least one of vinyl pyridine, vinyl pyrrolidone, and vinyl imidazole.
9. The high-hardness antibacterial coating according to claim 1, characterized in that: The diluent is selected from at least one of ethyl acetate, propylene glycol methyl ether acetate, butyl acetate, acetone, cyclohexanone, toluene, and xylene.
10. A method for preparing a high-hardness antibacterial coating, characterized in that: include: According to the ratio of any one of claims 1 to 9, pentaerythritol triacrylate, chain-extended organosilicon-modified acrylate, and cross-linked organosilicon-modified acrylate are uniformly mixed to obtain a premix; Add the antibacterial agent, photoinitiator and diluent to the premix, stir and mix, and filter to obtain the product.