A kind of water-based UV wear-resistant coating and preparation method thereof
By using isothiazolinone and benzotriazole structure additives to form a hybrid network structure in aqueous UV coatings, the poor film forming performance and bacterial contamination of aqueous UV coatings are solved, and high wear resistance and protection are achieved Improved antibacterial properties.
Patent Information
- Application Number
- CN202410188168.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-20
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2044-02-20
AI Technical Summary
The existing water-based UV coatings must be dehydrated and dried before photocuring. The system has low gloss, poor solvent resistance, poor abrasion resistance, poor film formation performance, and are susceptible to bacterial contamination, resulting in physical and chemical changes.
Using additives containing isothiazolinone and benzotriazole structures, the hybrid network structure is formed through nucleophilic substitution reaction and silane coupling reaction, which improves the anti-mildew, wear resistance and hardness of the coating, and is combined with Nanosilicon dioxide forms covalent bonds, enhancing the stability of the coating.
It significantly improves the wear resistance, hardness and anti-bacterial properties of water-based UV coatings, ensures the stability and long-term antibacterial effect of the coating, and improves the comprehensive performance of the coating.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of coatings, and in particular relates to a water-based UV wear-resistant coating and a preparation method thereof. Background Art
[0002] Traditional coatings contain a large amount of organic solvents, which seriously harm human health and affect the ecological environment. Therefore, solvent-free coatings, water-based coatings, UV coatings, etc. have become hot topics in recent years. Water-based ultraviolet (UV) coatings have excellent properties such as environmental protection, fast curing rate, and energy saving, which meet people's increasing environmental protection needs and have become an important direction for the development of coatings.
[0003] However, water-based UV coatings must be dehydrated and dried before light curing, and the system has low gloss, poor solvent resistance, poor scratch resistance, and poor film-forming properties, especially poor comprehensive properties such as weather resistance, hardness, wear resistance and toughness. In addition, the coating contains water and nutrients, which are easily contaminated by bacteria, resulting in harmful physical and chemical changes in the coating. Therefore, it is also very necessary to treat the coating with mildew and antibacterial treatment. Summary of the invention
[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a water-based UV wear-resistant coating and a preparation method thereof.
[0005] The purpose of the present invention can be achieved through the following technical solutions:
[0006] A water-based UV wear-resistant coating comprises the following components in parts by weight: 85-90 parts of epoxy acrylate, 12-15 parts of polyurethane prepolymer, 20-25 parts of acrylate, 4-6 parts of photoinitiator, 30-40 parts of water, 10-15 parts of nano silicon dioxide, 4-7 parts of cosolvent, 2-3 parts of auxiliary agent, 0.5-0.8 parts of defoamer, 0.3-0.4 parts of leveling agent and 0.3-0.4 parts of dispersant.
[0007] Furthermore, the photoinitiator is one or more of hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylphenyl acetone, 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, benzophenone, dialkoxyacetophenone, and coumarone.
[0008] Furthermore, the co-solvent is one or more of ethanol, methanol, isopropanol, butanol, propylene glycol ethyl ether, ethylene glycol ethyl ether, butanone, and acetone.
[0009] Furthermore, the defoamer is BYK-024 defoamer, the leveling agent is BYK-323 leveling agent, and the dispersant is BYK-2013 dispersant.
[0010] Furthermore, the auxiliary agent is prepared by the following steps:
[0011] S1. Under nitrogen protection, add isothiazolinone and ethanol into a dry four-necked flask, stir to fully mix, then add anhydrous sodium carbonate, heat to reflux, then slowly add 1,3-propylenediamine while stirring, and continue to reflux and stir for 4 hours. After the reaction is completed, cool to room temperature and distill under reduced pressure to obtain intermediate 1; the dosage ratio of isothiazolinone, 1,3-propylenediamine, anhydrous sodium carbonate and ethanol is 12mL:9.85mL:11.5g:120mL.
[0012] Under base catalysis, when the molar ratio of 1,3-propylenediamine to isothiazolinone is 1.0-1.2:1, isothiazolinone and 1,3-propylenediamine undergo a nucleophilic substitution reaction, and the reaction process is as follows:
[0013]
[0014] S2. Under nitrogen protection, add 2-(1-benzotriazole)acetic acid, intermediate 1, N,N-dimethylformamide (DMF) and concentrated sulfuric acid in a dry four-necked flask in sequence, stir thoroughly until mixed, heat the system to 120°C, and heat under reflux at this temperature for 8 hours. After the reaction is completed, pour the reactant into deionized water, shake and let stand to separate, wash the organic layer 3 times with 0.1 mol / L sodium bicarbonate solution, then wash with deionized water 3 times, and finally dry in a vacuum oven at 60°C to obtain intermediate 2; the dosage ratio of 2-(1-benzotriazole)acetic acid, intermediate 1, DMF and concentrated sulfuric acid is 10.6 g:13.5 g:120 mL:0.4 mL.
[0015] Under the catalytic action of concentrated sulfuric acid, -COOH on 2-(1-benzotriazole)acetic acid and -NH2 on the modifier molecule undergo dehydration condensation reaction to obtain intermediate 2. The reaction equation is as follows:
[0016]
[0017] S3. Under nitrogen protection, add 3-chloro-1-propanol, DMF and triethylamine into a dry brown four-necked flask, stir thoroughly until mixed, then slowly add intermediate 2, stir thoroughly, then heat to 85°C, reflux at 85°C for 4 hours, cool to room temperature after the reaction, evaporate the solvent, purify by column chromatography (the eluent is a mixed solvent of benzene and acetone, the volume ratio of benzene and acetone is 9:1), evaporate the solvent to obtain intermediate 3; the usage ratio of 3-chloro-1-propanol, intermediate 2, triethylamine and DMF is 2.1mL:9.1g:3.6mL:110mL.
[0018] Under base catalysis, 3-chloro-1-propanol reacts with intermediate 2 to undergo a nucleophilic substitution reaction. The reaction process is as follows:
[0019]
[0020] S4. Add γ-(methacryloyloxy)propyltrimethoxysilane (silane coupling agent KH570), intermediate 3, DMF and tetraisopropyl titanate to a dry three-necked flask under nitrogen protection, stir thoroughly until mixed, heat the system to 100°C, react at 100°C for 36 hours, cool to room temperature after the reaction, and distill under reduced pressure to obtain an auxiliary agent. The dosage ratio of silane coupling agent KH570, intermediate 3, DMF and tetraisopropyl titanate is 7mL:10.1g:120mL:0.21g.
[0021] Under the catalytic action of tetraisopropyl titanate, the molar ratio of silane coupling agent KH570 and intermediate 2 is controlled to be 1.0-1.2:1, and the two undergo the following chemical reaction, and the reaction process is as follows:
[0022]
[0023] The isothiazolinone structure can effectively kill bacteria and fungi, and is non-toxic and pollution-free. It has a wide range of pH applications and is easily biodegraded into non-toxic and harmless substances. The benzotriazole structure can interfere with the metabolic process of microorganisms and molds. The three nitrogen atoms in its molecular structure can bind to the antibacterial substances in the cell membrane and cells, thereby preventing the growth and reproduction of microorganisms and molds. It plays a synergistic role with the isothiazolinone structure, giving the additive excellent mildew and antibacterial properties. The additive molecule contains silane alkoxy groups, which are easily hydrolyzed and condensed in water, and then covalently bonded with the hydroxyl groups on the nano-silica, so that the nano-silica is highly dispersed and stably present in the coating, thereby improving the wear resistance and hardness of the coating. The Si-O-Si chain between the additive and the nano-silica forms a hybrid network structure in the coating, which also improves the mechanical properties of the coating to a certain extent. The additive molecule also contains methacrylate groups, which can be cross-linked with the matrix resin under the action of a photoinitiator, thereby firmly binding to the coating, thereby giving the coating excellent and stable mildew and antibacterial properties.
[0024] A method for preparing a water-based UV wear-resistant coating comprises the following steps:
[0025] Add epoxy acrylate, polyurethane prepolymer, acrylate, water and cosolvent into a stirring kettle in proportion, stir at 400 r / min for 5 min, then slowly add additives, nano-silica, defoamer, leveling agent and dispersant while stirring, stir at 600 r / min for 5 min, finally slowly add photoinitiator, stir and disperse at 1000 r / min for 1 h to obtain a water-based UV wear-resistant coating.
[0026] The beneficial effects of the present invention are as follows: the additive containing isothiazolinone structure and benzotriazole structure successfully bridges between the inorganic raw materials and the organic raw materials of the coating through methacrylate group and silaneoxy group to form a hybrid network structure, thereby giving the coating excellent and stable mildew and antibacterial properties, wear resistance and hardness. DETAILED DESCRIPTION
[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0028] Example 1
[0029] Preparation of auxiliary agent, the specific steps are as follows:
[0030] S1. Under nitrogen protection, 12 mL of isothiazolinone and 120 mL of ethanol were added to a dry 250 mL four-necked flask. After stirring to fully mix, 11.5 g of anhydrous sodium carbonate was added, and the mixture was heated to reflux. Then, 9.85 mL of 1,3-propylenediamine was slowly added while stirring. The mixture was refluxed and stirred for 4 h. After the reaction was completed, the mixture was cooled to room temperature and distilled under reduced pressure to obtain intermediate 1.
[0031] S2. In a dry 250 mL four-necked flask under nitrogen protection, 10.6 g of 2-(1-benzotriazole)acetic acid, 120 mL of DMF and 0.4 mL of concentrated sulfuric acid were added in sequence, and the mixture was stirred thoroughly until uniformly mixed. The system was heated to 120° C. and heated under reflux at this temperature for 8 h. After the reaction was completed, the reactant was poured into deionized water, shaken and allowed to stand for stratification. The organic layer was washed 3 times with 0.1 mol / L sodium bicarbonate solution, and then washed 3 times with deionized water, and finally dried in a vacuum oven at 60° C. to obtain intermediate 2.
[0032] S3. Under nitrogen protection, add 2.1 mL of 3-chloro-1-propanol, 110 mL of DMF and 3.6 mL of triethylamine to a dry 250 mL brown four-necked flask, stir thoroughly until mixed, then slowly add 9.1 g of intermediate 2, stir thoroughly, then heat to 85°C, reflux at 85°C for 4 h, cool to room temperature after the reaction, evaporate the solvent, purify by column chromatography (the eluent is a mixed solvent of benzene and acetone, the volume ratio of benzene and acetone is 9:1), evaporate the solvent to obtain intermediate 3;
[0033] S4. Under nitrogen protection, add 7 mL of γ-(methacryloyloxy)propyltrimethoxysilane, 10.1 g of intermediate 3, 120 mL of DMF and 0.21 g of tetraisopropyl titanate into a dry 250 mL three-necked flask, stir thoroughly until the mixture is uniform, heat the system to 100 °C, react at 100 °C for 36 h, cool to room temperature after the reaction is completed, and distill under reduced pressure to obtain an auxiliary agent.
[0034] Example 2
[0035] Preparation of auxiliary agent, the specific steps are as follows:
[0036] The remaining steps remain unchanged, and step S4 of Example 1 is removed to prepare the auxiliary agent.
[0037] Example 3
[0038] Preparation of water-based UV wear-resistant coating, the specific steps are as follows:
[0039] 87 parts of epoxy acrylate, 13 parts of polyurethane prepolymer, 23 parts of acrylate, 35 parts of water and 6 parts of isopropanol were added to a stirring tank and stirred at 400 r / min for 5 minutes. Then, 2 parts of the additive of Example 1, 10 parts of nano-silicon dioxide, 0.6 parts of BYK-024 defoamer, 0.35 parts of BYK-323 leveling agent and 0.35 parts of BYK-2013 dispersant were slowly added while stirring, and stirred at 600 r / min for 5 minutes. Finally, hydroxycyclohexyl phenyl ketone was slowly added, and stirred and dispersed at 1000 r / min for 1 hour to obtain a water-based UV wear-resistant coating.
[0040] Example 4
[0041] Preparation of water-based UV wear-resistant coating, the specific steps are as follows:
[0042] 90 parts of epoxy acrylate, 12 parts of polyurethane prepolymer, 20 parts of acrylate, 40 parts of water and 7 parts of ethylene glycol ether were added to a stirring kettle and stirred at 400 r / min for 5 min. Then, 3 parts of the additive of Example 1, 15 parts of nano-silicon dioxide, 0.8 parts of BYK-024 defoamer, 0.4 parts of BYK-323 leveling agent and 0.4 parts of BYK-2013 dispersant were slowly added while stirring, and stirred at 600 r / min for 5 min. Finally, benzophenone was slowly added, and stirred and dispersed at 1000 r / min for 1 h to obtain a water-based UV wear-resistant coating.
[0043] Example 5
[0044] Preparation of water-based UV wear-resistant coating, the specific steps are as follows:
[0045] 85 parts of epoxy acrylate, 15 parts of polyurethane prepolymer, 25 parts of acrylate, 30 parts of water and 4 parts of acetone were added to a stirring kettle, stirred at 400 r / min for 5 minutes, then 2.2 parts of the additive of Example 1, 11 parts of nano-silicon dioxide, 0.5 parts of BYK-024 defoamer, 0.3 parts of BYK-323 leveling agent and 0.3 parts of BYK-2013 dispersant were slowly added while stirring, stirred at 600 r / min for 5 minutes, and finally 2-hydroxy-2-methylphenylacetone was slowly added, and stirred and dispersed at 1000 r / min for 1 hour to obtain a water-based UV wear-resistant coating.
[0046] Comparative Example 1
[0047] The specific steps for preparing the coating are as follows:
[0048] The remaining steps remain unchanged, and the additives in Example 3 are removed to prepare the coating.
[0049] Comparative Example 2
[0050] The specific steps for preparing the coating are as follows:
[0051] The remaining steps remain unchanged, and the auxiliary agent in Example 3 is replaced by the auxiliary agent in Example 2 to prepare the coating.
[0052] Performance Testing
[0053] The coatings of Examples 3-5 and Comparative Examples 1-2 were coated on the surface of plastic materials and cured by UV radiation to form films, and then tested. The test results are shown in Table 1 below:
[0054] Table 1 Coating properties
[0055]
[0056] It can be seen from the above data that the water-based UV wear-resistant coatings prepared in Examples 3-5 of the present invention have excellent hardness and wear resistance.
[0057] The coatings prepared in Examples 3-5 and Comparative Examples 1-3 were tested according to the HG / T3950-2007 method. The test results are shown in Table 2 below:
[0058] When the antibacterial rate is ≥99%, the antibacterial performance is level I; when it is ≥90%, the antibacterial performance is level II;
[0059] Antibacterial rate ≥95%, antibacterial durability is level I, ≥85%, antibacterial performance is level II;
[0060] Mold growth level: Level 0 - no growth, that is, no growth is observed under a microscope; Level 1 - trace growth, the growth coverage area is less than 10%; Level 2 - the growth coverage area is greater than 10%;
[0061] When the anti-mildew durability performance is level I, the mildew growth level is level 0; when the anti-mildew durability performance is level II, the mildew growth level is level 1.
[0062] Table 2 Antibacterial and antifungal properties
[0063]
[0064] It can be seen from the data in Table 2 that the water-based UV wear-resistant coatings prepared in Examples 3-5 of the present invention have excellent mildew and antibacterial properties, and the additives play an important role in improving the mildew and antibacterial durability of the coatings.
[0065] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
[0066] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.
Claims
1. A water-based UV wear-resistant coating, characterized in that: The invention comprises the following components in parts by weight: 85-90 parts of epoxy acrylate, 12-15 parts of polyurethane prepolymer, 20-25 parts of acrylate, 4-6 parts of photoinitiator, 30-40 parts of water, 10-15 parts of nano silicon dioxide, 4-7 parts of cosolvent, 2-3 parts of auxiliary agent, 0.5-0.8 parts of defoamer, 0.3-0.4 parts of leveling agent and 0.3-0.4 parts of dispersant; Wherein, the auxiliary agent is prepared by the following steps: S1. Add isothiazolinone and ethanol into a flask, add anhydrous sodium carbonate after stirring, heat to reflux, add 1,3-propylenediamine, stir for 4 hours, cool, and distill under reduced pressure to obtain intermediate 1; the dosage ratio of isothiazolinone, 1,3-propylenediamine, anhydrous sodium carbonate and ethanol is 12mL:9.85mL:11.5g:120mL; S2. Add 2-(1-benzotriazole)acetic acid, intermediate 1, DMF and concentrated sulfuric acid into a flask, stir and heat to 120°C, reflux for 8 hours, pour the reactants into deionized water after completion, let stand, wash the organic layer with sodium bicarbonate solution, then with deionized water, and dry to obtain intermediate 2; the dosage ratio of 2-(1-benzotriazole)acetic acid, intermediate 1, DMF and concentrated sulfuric acid is 10.6g:13.5g:120mL:0.4mL; S3, add 3-chloro-1-propanol, DMF and triethylamine to a flask, stir, then add intermediate 2, react at 85°C for 4h, cool, evaporate the solvent, purify by column chromatography, evaporate the solvent to obtain intermediate 3; the amount ratio of 3-chloro-1-propanol, intermediate 2, triethylamine and DMF is 2.1mL:9.1g:3.6mL:110mL; S4. Add silane coupling agent KH570, intermediate 3, DMF and tetraisopropyl titanate into a flask, stir, heat to 100°C to react for 36 hours, cool, and distill under reduced pressure to obtain an auxiliary agent; the dosage ratio of silane coupling agent KH570, intermediate 3, DMF and tetraisopropyl titanate is 7 mL:10.1 g:120 mL:0.21 g.
2. A water-based UV wear-resistant coating according to claim 1, characterized in that: The photoinitiator is one or more of hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylphenyl acetone, 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, benzophenone, dialkoxy acetophenone and coumarone.
3. A water-based UV wear-resistant coating according to claim 1, characterized in that: The co-solvent is one or more of ethanol, methanol, isopropanol, butanol, propylene glycol ethyl ether, ethylene glycol ethyl ether, butanone and acetone.
4. A water-based UV wear-resistant coating according to claim 1, characterized in that: The defoaming agent is BYK-024 defoaming agent, the leveling agent is BYK-323 leveling agent, and the dispersant is BYK-2013 dispersant.
5. The method for preparing a water-based UV wear-resistant coating according to claim 1, characterized in that: The steps include: Add epoxy acrylate, polyurethane prepolymer, acrylate, water and cosolvent into a stirring kettle in proportion, stir at 400 r / min for 5 min, then slowly add additives, nano-silica, defoamer, leveling agent and dispersant while stirring, stir at 600 r / min for 5 min, finally slowly add photoinitiator, stir and disperse at 1000 r / min for 1 h to obtain a water-based UV wear-resistant coating.