Composition and preparation method of a UV-curable self-cleaning antibacterial coating

Abstract

The present invention relates to a composition and preparation method for a UV-curable self-cleaning antibacterial coating. The composition comprises: an imidazole-modified fluoroacrylate resin, a reactive diluent, a photoinitiator, a wear-resistant powder, and an additive. First, imidazole ethyl methacrylate and acetonitrile are added to a reactor, and brominated dodecane is slowly added dropwise to synthesize a brominated imidazole acrylate monomer BA. Hydroxyethyl acrylate, styrene, isooctyl acrylate, perfluorodecyl acrylate, brominated imidazole acrylate monomer BA, and ethyl acetate are reacted in the presence of a catalyst to produce an imidazole-modified fluoroacrylate resin. The imidazole-modified fluoroacrylate resin and isocyanoethyl acrylate are then introduced into the imidazole-modified fluoroacrylate resin in the presence of a catalyst and a polymerization inhibitor to introduce functional groups required for photocuring, thereby producing a photosensitive imidazole-modified fluoroacrylate resin. The coating is then mixed with other components to produce a product. The product has good antibacterial and self-cleaning properties, excellent adhesion and wear resistance, fast curing speed, and is environmentally friendly and energy-saving.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, in particular to an ultraviolet (UV) curing functional coating, and is a composition of an ultraviolet curing self-cleaning antibacterial coating and a preparation method thereof. Background Art

[0002] UV curing is a type of radiation curing and an environmentally friendly curing method. It can significantly reduce curing energy consumption and has high energy utilization. It can be applied to heat-sensitive substrates and has the advantages of being pollution-free, fast curing, high coating quality, and suitable for continuous large-scale production. However, the coating is prone to breeding bacteria when exposed to the air for a long time, which has a great impact on the aesthetics and use value of the coating, and also threatens human health. In order to solve these problems, it is necessary to modify the UV curing coating. The UV curing self-cleaning antibacterial coating is prepared by using a special macromolecular imidazole-modified fluoroacrylate resin as the main body, and then combining it with an active diluent, a photoinitiator, and an auxiliary agent. In the field of UV curing coatings, obtaining a coating with sustained excellent antibacterial properties, chemical resistance, and excellent adhesion has always been a difficult problem that is difficult to be effectively solved. The performance and function of the UV curing self-cleaning antibacterial coating can meet the current market requirements for the environmental protection of coating products. It not only has the functions of self-cleaning and continuous antibacterial, but also has excellent wear resistance and adhesion, which can meet users' high-end requirements for environmentally friendly coatings.

[0003] At present, in China, the antibacterial modification and anti-adhesion modification of materials can be used to prevent bacteria from growing on the surface of materials. One method is to add metal ions to obtain antibacterial effects, but this cold-mixing method has migration problems, poor antibacterial durability, and safety issues. Another method is to fix antibacterial molecules in the coating in the form of covalent bonds, thereby avoiding the migration of antibacterial components and the harm caused by the release of antibacterial agents into the environment. However, this method of single organic modification has poor antibacterial effect. Combining inorganic and organic modified antibacterial technologies will cause compatibility problems. Yang Jun et al. reported in CN 101353545B "Ultraviolet antibacterial coating and its preparation method" uses a combination of heterocyclic acrylates containing special antibacterial groups and nanosilver to achieve good antibacterial effects, but there is a compatibility problem; Professor Wang Zhongming's research group at Beijing University of Chemical Technology has been engaged in the research of UV-curable antibacterial coatings for many years. By modifying the molecular chain of polyurethane oligomers with multiple antibacterial groups and cold-blending fluorine-containing acrylate monomers, an antibacterial adhesion coating is obtained, which has a synergistic antibacterial effect. The ability of small-molecule fluorine-containing acrylates to quickly migrate to the coating surface is limited, resulting in a short-term antibacterial adhesion ability, and the special antibacterial groups and fluorine elements are not organically combined. Summary of the Invention

[0004] In order to overcome the technical problems of existing UV-curable antibacterial coatings, such as poor sustained antibacterial ability and compatibility, the purpose of the present invention is to synthesize a high-molecular-weight imidazole-modified fluoroacrylate resin containing special antibacterial groups, and prepare a UV-curable self-cleaning antibacterial coating. The antibacterial groups, through mutual electrostatic interaction, enable quaternary ammonium cations to bind to bacterial cell membranes with negative charges on the surface. The hydrophobic components of the quaternary ammonium salt bind to the phospholipid bilayer of the bacterial cell membrane and lyse the cell membrane, allowing proteins and other components of the bacterial cell to flow out and kill the bacteria. The introduction of long-chain fluorine enables the coating to obtain a lower surface energy, greatly improves the anti-adhesion performance against bacteria, prevents the formation of biofilm on the coating surface, achieves a self-cleaning effect, and forms a synergistic antibacterial effect. The introduction of hydroxyethyl acrylate greatly increases the adhesion to the substrate. Moreover, due to the introduction of light-curable acrylate groups, the migration safety problem of the antibacterial groups is effectively solved, which conforms to the trend of green, environmental protection and energy saving.

[0005] The technical solution of the present invention is: a UV-curable self-cleaning antibacterial coating, which is prepared from the following components by weight:

[0006]

[0007] Among them, the imidazole-modified fluoroacrylate resin is composed of the following raw materials in parts by weight:

[0008]

[0009] Wherein, the catalyst is azo or organotin, and the polymerization inhibitor is p-hydroxyanisole.

[0010] The imidazole-modified fluoroacrylate resin is synthesized by the following method:

[0011] Imidazole ethyl methacrylate and acetonitrile are added to a reaction kettle, and brominated dodecane is slowly added dropwise for 1-2 hours, and the mixture is reacted at 60-75°C for 16 hours to synthesize a brominated imidazole acrylate monomer BA for use in a subsequent reaction. Hydroxyethyl acrylate, styrene, isooctyl acrylate, perfluorodecyl acrylate, brominated imidazole acrylate monomer BA, and ethyl acetate are added dropwise under the initiation of a catalyst for 3-4 hours, and the mixture is reacted at 50-60°C for 12 hours to obtain an imidazole-modified fluoroacrylate resin. The imidazole-modified fluoroacrylate resin is then reacted with isocyanoethyl acrylate under the action of a catalyst and an inhibitor at 50-60°C for 5-7 hours to introduce functional groups required for photocuring and obtain a photosensitive imidazole-modified fluoroacrylate resin.

[0012] The catalyst comprises any one or more of azobisisobutyronitrile, azobisisoheptanenitrile and dibutyltin dilaurate.

[0013] The active diluent is one or more of tripropylene glycol diacrylate, trihydroxymethane triacrylate, 1,6-hexanediol diacrylate and pentaerythritol triacrylate.

[0014] The photoinitiator is one or more of 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, benzophenone, and methyl o-benzoylbenzoate.

[0015] The wear-resistant powder is one or more of nano silicon dioxide and nano aluminum oxide.

[0016] The auxiliary agent is one or more of BYK333, BYK088 and BYK055.

[0017] The method for preparing the UV-curable self-cleaning antibacterial coating comprises first preparing the imidazole-modified fluoroacrylate resin, and then uniformly mixing it with other components to prepare the coating, and controlling relevant indicators; fineness: <30um; viscosity: 1000-2500mpas / 25°C.

[0018] The curing process of the UV-curable self-cleaning antibacterial coating is to use a roller coater to coat the coating, and the coating amount is controlled at 10-15g / cm 2 , through UVA greater than 400mj / cm 2 The energy is fully cured, and the obtained coating has an anti-Escherichia coli and Staphylococcus aureus rate of more than 99.5%.

[0019] Beneficial effects:

[0020] The present invention prepares a UV-curable self-cleaning antibacterial coating, in which the raw material imidazole-modified fluoroacrylate resin used has brominated imidazole antibacterial groups and fluorine elements that provide low surface energy. The antibacterial groups, through mutual electrostatic interaction, enable quaternary ammonium cations to bind to bacterial cell membranes with negative surface charges, and the hydrophobic components of the quaternary ammonium salt bind to the phospholipid bilayer of the bacterial cell membrane and lyse the cell membrane, allowing proteins and other components of the bacterial cells to flow out and kill the bacteria. The introduction of long-chain fluorine enables the coating to obtain lower surface energy, greatly improves the anti-adhesion performance against bacteria, prevents the formation of biofilm on the coating surface, achieves a self-cleaning effect, and forms a synergistic antibacterial effect. The introduction of hydroxyethyl acrylate into the main chain of the acrylate resin further greatly improves the adhesion to the substrate. Therefore, the final antibacterial coating has good antibacterial and self-cleaning properties, excellent adhesion and wear resistance, fast curing speed, environmental protection, and energy saving.

[0021] When the coating amount reaches 10-15g / m 2 When the UVA is greater than 400mj / cm 2The energy is fully cured, and the obtained coating has an anti-Escherichia coli and Staphylococcus aureus rate of more than 99.5%, and is long-lasting. DETAILED DESCRIPTION

[0022] The preparations used in the present invention are all commercially available conventional products, regardless of the manufacturer, as long as they are qualified industrial products.

[0023] Throughout this application, the following terms have the designated meanings:

[0024] Code or term Chinese name PFB Imidazole-modified fluoroacrylate resin, homemade PETA Pentaerythritol triacrylate, TMPTA Trimethylolpropane triacrylate, obtained from Shanghai Allnex TPGDA Tripropylene glycol diacrylate, obtained from Shanghai Allnex TPO 2,4,6-Trimethylbenzoyl-diphenylphosphine oxide, obtained from Tianjin Jiuri Chemical 1173 2-Hydroxy-2-methyl-1-phenyl-1-propanone, obtained from Tianjin Jiuri Chemical BKY055 Defoamer from BYK BYK333 Leveling agent from BYK Wear-resistant powder Alumina wear-resistant powder, obtained from Hangzhou Wanjing New Materials

[0025] The present invention will be further described below with reference to the embodiments.

[0026] A composition and preparation method of a UV-curable self-cleaning antibacterial coating, comprising:

[0027]

[0028] The imidazole-modified fluoroacrylate resin is the product of the following reactants: hydroxyethyl acrylate, with an amount of 10%-15% of the total reaction amount, styrene, with an amount of 5%-10% of the total reaction amount, isooctyl acrylate, with an amount of 5%-10% of the total reaction amount, perfluorodecyl acrylate, with an amount of 5%-15% of the total reaction amount, imidazole ethyl methacrylate, with an amount of 10%-20% of the total reaction amount, dodecane bromide, with an amount of 10%-20% of the total reaction amount, acetonitrile, with an amount of 5%-10% of the total reaction amount, and isocyanoethyl acrylate, with an amount of 10%-15% of the total reaction amount. The catalyst is azo, organotin, but not limited to, azobisisobutyronitrile, azobisisoheptonitrile, and dibutyltin dilaurate, and the amount is 0.3%-0.5% of the total reaction amount.

[0029] The imidazole-modified fluoroacrylate resin has a brominated imidazole antibacterial group and a fluorine element that provides low surface energy, which prevents the formation of biofilm on the coating surface, achieves a self-cleaning effect, and forms a synergistic antibacterial effect.

[0030] The introduction of hydroxyethyl acrylate into the main chain of acrylate resin greatly improves the adhesion to the substrate.

[0031] The imidazole-modified fluoroacrylate resin is synthesized as follows:

[0032] Imidazole ethyl methacrylate and acetonitrile are added to a reaction kettle, and brominated dodecane is slowly added dropwise for 1-2 hours, and the mixture is reacted at 60-75°C for 16 hours to synthesize a brominated imidazole acrylate monomer BA, which is used for the subsequent reaction. Hydroxyethyl acrylate, styrene, isooctyl acrylate, perfluorodecyl acrylate, brominated imidazole acrylate monomer BA, and ethyl acetate are added dropwise under the initiation of azobisisobutyronitrile for 3-4 hours, and the mixture is reacted at 50-60°C for 12 hours to obtain an imidazole-modified fluoroacrylate resin. The imidazole-modified fluoroacrylate resin is then reacted with isocyanoethyl acrylate in the presence of a catalyst and an inhibitor at 50-60°C for 5-7 hours to introduce functional groups required for photocuring, thereby obtaining a photosensitive imidazole-modified fluoroacrylate resin.

[0033] The content of the imidazole-modified fluoroacrylate resin is 45wt%-65wt%;

[0034] The active diluent is one or more of tripropylene glycol diacrylate, trihydroxymethane triacrylate, 1,6-hexanediol diacrylate, and pentaerythritol triacrylate; the photoinitiator is one or more of 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, benzophenone, and methyl o-benzoylbenzoate; the wear-resistant powder is one or more of nano-silica and nano-alumina; and the auxiliary agent is one or more of BYK333, BYK088, and BYK055.

[0035] The curing process of the coating is to use a roller coater to apply the coating at a coating amount of 10-15g / cm 2 , through UVA greater than 400mj / cm 2 Energy fully cured, the obtained coating has an anti-Escherichia coli and Staphylococcus aureus rate of more than 99.5%, and is long-lasting. Example 1 Preparation of PFB from imidazole-modified fluoroacrylic resin

[0036] The synthesis of imidazole-modified fluoroacrylate resin was carried out according to the three groups of data listed in Table 1.

[0037]

[0038]

[0039] Example 1 Synthetic resin

[0040] First, imidazole ethyl methacrylate is pumped into a reactor, acetonitrile is added, and then bromide dodecane is slowly added dropwise for 1-2 hours, and the mixture is reacted at 60-75°C for 16 hours to synthesize a bromimidazole acrylate monomer BA for use in the subsequent reaction. Ethyl acetate is pumped into a reactor, hydroxyethyl acrylate, styrene, isooctyl acrylate, perfluorodecyl acrylate, bromimidazole acrylate monomer BA, and azobisisobutyronitrile are premixed, and then the mixture is added dropwise to the reactor for 3-4 hours, and the mixture is reacted at 50-60°C for 12 hours until the monomer reaction is complete. Subsequently, the temperature of the reaction system is lowered to 40°C, and isocyanoethyl acrylate, dibutyltin dilaurate, and p-hydroxyanisole are added dropwise. The mixture is reacted at 50-60°C for 5-7 hours until the -NCO in the system is completely reacted, thereby introducing the functional group required for photocuring and preparing a photosensitive imidazole-modified fluoroacrylate resin. The relevant indicators of this PFB are: viscosity 3000-5000mPa.s / 40℃; NCO<0.1%.

[0041] Example 2 Preparation of PFB from Imidazole-Modified Fluoroacrylic Resin

[0042] The synthesis of imidazole-modified fluoroacrylate resin was carried out according to the three groups of data listed in Table 2.

[0043]

[0044]

[0045] Example 2 Synthetic resin

[0046] First, imidazole ethyl methacrylate is pumped into a reactor, acetonitrile is added, and then bromide dodecane is slowly added dropwise for 1-2 hours, and the mixture is reacted at 60-75°C for 16 hours to synthesize a bromimidazole acrylate monomer BA for use in the subsequent reaction. Ethyl acetate is pumped into a reactor, hydroxyethyl acrylate, styrene, isooctyl acrylate, perfluorodecyl acrylate, bromimidazole acrylate monomer BA, and azobisisobutyronitrile are premixed, and then the mixture is added dropwise to the reactor for 3-4 hours, and the mixture is reacted at 50-60°C for 12 hours until the monomer reaction is complete. Subsequently, the temperature of the reaction system is lowered to 40°C, and isocyanoethyl acrylate, dibutyltin dilaurate, and p-hydroxyanisole are added dropwise. The mixture is reacted at 50-60°C for 5-7 hours until the -NCO in the system is completely reacted, thereby introducing the functional group required for photocuring and preparing a photosensitive imidazole-modified fluoroacrylate resin. The relevant indicators of this PFB are: viscosity 3000-5000mPa.s / 40℃; NCO<0.1%.

[0047] Example 3 Preparation of UV-curable self-cleaning antibacterial coating

[0048] The paint is prepared according to the three sets of data formulas in Table 3 below.

[0049]

[0050] The above components are prepared into coatings and relevant indicators are controlled; fineness: <30um; viscosity: 1000-2500mpas / 25℃.

[0051] Example 4 Preparation of UV-curable self-cleaning antibacterial coating

[0052] The paint is prepared according to the three sets of data formulas in Table 4 below.

[0053]

[0054] The above components are prepared into coatings and relevant indicators are controlled; fineness: <30um; viscosity: 1000-2500mpas / 25℃.

[0055] Example 5 Preparation of UV-curable self-cleaning antibacterial coating

[0056] The paint is prepared according to the three sets of data formulas in Table 5 below.

[0057]

[0058] The above components were prepared into a coating, and the relevant indicators were controlled: fineness: <30 μm; viscosity: 1000-2500 mPas / 25°C. Example 6 Preparation of UV-curable self-cleaning antibacterial coating

[0059] The paint is prepared according to the three sets of data formulas in Table 6 below.

[0060]

[0061] The above components are prepared into coatings and relevant indicators are controlled; fineness: <30um; viscosity: 1000-2500mpas / 25℃.

[0062] Example 7 Preparation of UV-curable self-cleaning antibacterial coating

[0063] The paint is prepared according to the three sets of data formulas in Table 7 below.

[0064] The above components are prepared into coatings and relevant indicators are controlled; fineness: <30um; viscosity: 1000-2500mpas / 25℃.

[0065] Example 8 Preparation of UV-curable self-cleaning antibacterial coating

[0066] The paint is prepared according to the three sets of data formulas in Table 8 below.

[0067]

[0068]

[0069] The above components are prepared into coatings and relevant indicators are controlled; fineness: <30um; viscosity: 1000-2500mpas / 25℃.

[0070] Example 9 Antibacterial Performance Test:

[0071] 1. Determination of general conditions

[0072] Ambient temperature 20-25℃; relative humidity 40-60%; ambient pressure 1.013*10 5 5% pa; the laboratory cleanliness meets the requirements of GB50073-2001, and the 10,000-level cleanliness level has a dust content of ≧0.5um ≤ 350 particles / L.

[0073] 2. Preparation of coating samples

[0074] On the plastic surface, use a roller coater to apply 10-15g / m 2 , film is formed by UV curing, and the curing energy UVA is greater than 400mj / cm 2 After curing, place it for 24 hours to cool and then test. The wear resistance is tested according to GB / T1768-2006 and the antibacterial performance is tested according to HG / T3950-2007. Tables 9 and 10 are the antibacterial performance tests of the three groups of experiments 3, 4, 5, 6, 7, and 8 above.

[0075] Table 9 Performance test of UV-curable self-cleaning antibacterial coating

[0076]

[0077] Table 10 Performance test of UV-curable self-cleaning antibacterial coating

[0078]

[0079]

[0080] From the above data, it can be seen that the UV-curing coating with imidazole-modified fluoroacrylic resin has greatly improved the antibacterial properties of the coating, which is mainly due to the addition of special brominated imidazole antibacterial groups. The antibacterial groups, through mutual electrostatic interaction, allow quaternary ammonium cations to bind to the bacterial cell membrane with a negative charge on the surface. The hydrophobic components of the quaternary ammonium salt bind to the phospholipid bilayer of the bacterial cell membrane and lyse the cell membrane, allowing proteins and other components of the bacterial cell to flow out and kill the bacteria. The introduction of long-chain fluorine enables the coating to obtain a lower surface energy, greatly improving the anti-adhesion properties to bacteria, preventing the formation of biofilm on the coating surface, achieving a self-cleaning effect, and forming a synergistic antibacterial effect. Because it contains light-curable double bonds, it participates in the cross-linking reaction of the coating, so that the fluorine element and the antibacterial group can be riveted to the coating surface, avoiding the migration of the antibacterial agent and achieving continuous antibacterial ability. With the increase of antibacterial groups and fluorine content, the antibacterial durability of the coating also increases.

Claims

1. A UV-curable self-cleaning antibacterial coating, characterized in that: It is prepared from the following components by weight: 45-65 parts of imidazole-modified fluoroacrylate resin, 20~35 parts of active diluent, 3.0~5.0 parts of photoinitiator, 2.0~5.0 parts of wear-resistant powder, 1~3 parts of additives; Among them, the imidazole-modified fluoroacrylate resin is composed of the following raw materials in parts by weight: Hydroxyethyl acrylate, 10-15 parts, Styrene, 5-10 parts, Isooctyl acrylate, 5-10 parts, Perfluorodecyl acrylate, 5-15 parts, Imidazole ethyl methacrylate, 10-20 parts, Bromododecane, 10-20 parts, Acetonitrile, 5-10 parts, Ethyl acetate, 10-20 parts, Isocyanoethyl acrylate, 10-15 parts, 0.3-0.5 parts of catalyst, 0.3-0.5 parts of polymerization inhibitor, Wherein, the catalyst is azo or organotin, and the polymerization inhibitor is p-hydroxyanisole; The imidazole-modified fluoroacrylate resin is synthesized by the following method: Imidazole ethyl methacrylate and acetonitrile are added to a reaction kettle, and brominated dodecane is slowly added dropwise for 1-2 hours, and the mixture is reacted at 60-75°C for 16 hours to synthesize a brominated imidazole acrylate monomer BA for use in a subsequent reaction. Hydroxyethyl acrylate, styrene, isooctyl acrylate, perfluorodecyl acrylate, brominated imidazole acrylate monomer BA, and ethyl acetate are added dropwise under the initiation of a catalyst for 3-4 hours, and the mixture is reacted at 50-60°C for 12 hours to obtain an imidazole-modified fluoroacrylate resin. The imidazole-modified fluoroacrylate resin is then reacted with isocyanoethyl acrylate under the action of a catalyst and an inhibitor at 50-60°C for 5-7 hours to introduce functional groups required for photocuring and obtain a photosensitive imidazole-modified fluoroacrylate resin.

2. The UV-curable self-cleaning antibacterial coating according to claim 1, characterized in that: The catalyst comprises any one or more of azobisisobutyronitrile, azobisisoheptanenitrile and dibutyltin dilaurate.

3. The UV-curable self-cleaning antibacterial coating according to claim 1, characterized in that: The active diluent is one or more of tripropylene glycol diacrylate, trihydroxymethane triacrylate, 1,6-hexanediol diacrylate and pentaerythritol triacrylate.

4. The UV-curable self-cleaning antibacterial coating according to claim 1, characterized in that: The photoinitiator is one or more of 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, benzophenone, and methyl o-benzoylbenzoate.

5. The UV-curable self-cleaning antibacterial coating according to claim 1, characterized in that: The wear-resistant powder is one or more of nano silicon dioxide and nano aluminum oxide.

6. The UV-curable self-cleaning antibacterial coating according to claim 1, characterized in that: The auxiliary agent is one or more of BYK333, BYK088 and BYK055.

7. A method for preparing the UV-curable self-cleaning antibacterial coating according to any one of claims 1 to 6, characterized in that: First, the imidazole-modified fluoroacrylate resin is prepared, and then evenly mixed with other components to prepare a coating, and relevant indicators are controlled: fineness: <30um; viscosity: 1000-2500mpas / 25℃.

8. A curing process for a UV-curable self-cleaning antibacterial coating according to any one of claims 1 to 6, characterized in that: Use roller coater to apply the coating, and control the coating amount to 10-15g / cm 2 , through UVA greater than 400mj / cm 2 The energy is fully cured, and the obtained coating has an anti-Escherichia coli and Staphylococcus aureus rate of more than 99.5%.

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