A uv coating with antifouling effect and a preparation method thereof

Abstract

This invention relates to the field of coating technology and discloses a UV coating with antifouling effect and its preparation method. The UV coating of this invention comprises a UV polyurethane emulsion, an active diluent, a photoinitiator, and an alkenyl fluorinated silicone oil in a ratio of 100g:(10-14)g:(3-3.6)g:(4-10)g. The alkenyl fluorinated silicone oil contains hydrophobic, low surface energy polysiloxane molecular chains and perfluoroalkyl groups, which are uniformly dispersed in the polyurethane emulsion and the coating film, reducing the surface energy and water contact angle of the coating film, thus improving waterproof and antifouling performance, and significantly enhancing salt spray resistance. The alkenyl fluorinated silicone oil contains alkenyl groups, which can undergo alkenyl crosslinking polymerization with UV polyurethane, introducing flexible polysiloxane molecular chains into the polyurethane coating film, thereby improving the impact resistance and flexibility of the coating film.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a UV coating with antifouling effect and its preparation method. Background Technology

[0002] Polyurethane acrylates possess excellent UV curing properties, exhibiting rapid curing, good film-forming properties, high adhesion, and environmental friendliness, making them widely used in coatings and inks. To improve the anti-pollution and salt spray resistance properties of UV polyurethane coatings and expand their practical applications in high-salt and high-humidity environments, chemical modification is necessary.

[0003] Adding low-surface-energy hydrophobic substances such as fluorosilicone to polyurethane can effectively reduce the surface energy of the coating film and improve its hydrophobic, oleophobic, anti-fouling, and salt spray corrosion resistance properties. Patent CN111748275B discloses the introduction of organosilicon and organofluoropolymers into polyurethane coatings, giving them properties such as low surface energy, acid and alkali resistance, and good transparency. However, this patent does not improve the impact resistance and flexibility of the polyurethane coating film. Summary of the Invention

[0004] (I) Technical problem to be solved: In view of the shortcomings of the existing technology, the present invention provides a UV coating with antifouling effect and its preparation method, which solves the problem of poor antifouling and anticorrosion performance of polyurethane coatings.

[0005] (II) Technical solution: A UV coating with antifouling effect, comprising a UV polyurethane emulsion, an active diluent, a photoinitiator, an alkenyl fluorinated silicone oil, a surfactant, and a wetting and leveling agent in a ratio of 100g:(10-14)g:(3-3.6)g:(4-10)g:(0.04-0.12)g:(0.1-0.3)g.

[0006] Furthermore, the surfactant is a fluorosilicone surfactant.

[0007] Furthermore, the reactive diluents include tripropylene glycol diacrylate, dipropylene glycol diacrylate, and 1,6-hexanediol diacrylate.

[0008] Furthermore, the photoinitiator includes 1173.

[0009] Furthermore, the preparation method of alkenyl fluorinated silicone oil includes:

[0010] (1) Add perfluorinated acid, double-ended epoxy silicone oil and catalyst to toluene, stir and react, then evaporate by rotary evaporation. Centrifuge the product to remove solids, collect the oil layer, and obtain perfluorinated acid modified double-ended epoxy silicone oil.

[0011] (2) Add perfluorinated acid-modified double-ended epoxy silicone oil, isocyanate methacrylate, and triethylamine to dichloromethane, stir and react, then rotary evaporate. Add the product to water, stir, and allow to stand to separate into layers. Remove the water layer and dry the oil layer to obtain alkenyl fluorinated silicone oil. The preparation reaction formula is as follows:

[0012] .

[0013] Furthermore, in the preparation method of perfluorinated acid modified double-ended epoxy silicone oil in (1), the reaction is carried out at 80-110℃ for 4-7h.

[0014] Furthermore, in (1), the ratio of perfluorinated acid, double-ended epoxy silicone oil, and catalyst is (83-88) g: 100 g: (1.2-1.6) g.

[0015] Furthermore, in (1), perfluoroacid is C n F 2n+1 COOH, n is 2-10.

[0016] Furthermore, in (1), the catalyst is N,N-dimethylaniline or N,N-dimethylbenzylamine.

[0017] Furthermore, in (2), the ratio of perfluorinated acid modified double-ended epoxy silicone oil, isocyanate methacrylate, and triethylamine is 100g: (18-23)g: (0.3-0.4)g.

[0018] Furthermore, the reaction in (2) is carried out at 25-40℃ for 12-18h.

[0019] Furthermore, the preparation method of UV coating with antifouling effect includes: adding an active diluent, an alkenyl fluorinated silicone oil, a surfactant, and a wetting and leveling agent to a UV polyurethane emulsion, dispersing it in a shear mill, adding a photoinitiator, mixing it evenly, and obtaining a UV coating with antifouling effect.

[0020] (III) Beneficial Technical Effects of the Invention: The present invention adds an active diluent, an alkenyl fluorinated silicone oil, and a surfactant to a UV polyurethane emulsion to obtain a UV coating. The alkenyl fluorinated silicone oil contains urethane groups, which have good compatibility with the polyurethane molecular chain. Furthermore, under the action of the fluorinated silicone surfactant, the alkenyl fluorinated silicone oil can be uniformly dispersed in the polyurethane emulsion, preventing the emulsion from separating and ensuring good storage stability.

[0021] The alkenyl fluorinated silicone oil of the present invention contains hydrophobic, low surface energy polysiloxane molecular chains and perfluoroalkyl groups, which are uniformly dispersed in polyurethane emulsions and paint films. This significantly reduces the surface energy of the paint film, thereby reducing the water contact angle, which is beneficial to improving waterproof and anti-pollution performance, and also significantly improves salt spray resistance.

[0022] The alkenyl fluorinated silicone oil of the present invention contains alkenyl groups, which can undergo alkenyl crosslinking polymerization with UV polyurethane and reactive diluents, introducing flexible polysiloxane molecular chains into the polyurethane coating film, thereby improving the impact resistance and flexibility of the coating film. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] The following UV polyurethane emulsion is model number 33G32A, a waterborne polyurethane acrylate with a solid content of approximately 65%, manufactured by Guangdong Xidun New Materials. The double-ended epoxy silicone oil has an average molecular weight of approximately 1000, manufactured by Wuhan Kemike Biopharmaceutical. The wetting and leveling agent is model number TEGO500.

[0025] Example 1

[0026] (1) Add 16.6g of perfluorooctanoic acid, 20g of double-ended epoxy silicone oil and 0.32g of N,N-dimethylbenzylamine to 250mL of toluene, heat to 110℃, stir and react for 4h, reflux during the reaction, evaporate by rotary evaporation, separate the product by centrifugation to remove solids, collect the oil layer, and obtain perfluoroacid modified double-ended epoxy silicone oil.

[0027] (2) Add 50g of perfluorinated acid modified double-ended epoxy silicone oil, 10.2g of isocyanate methacrylate and 0.15g of triethylamine to 400mL of dichloromethane. Stir and react at 30℃ for 18h. Rotary evaporate the product and add it to water. After stirring, let it stand to separate the layers. Remove the water layer and dry the oil layer to obtain alkenyl fluorinated silicone oil.

[0028] (3) Add 140g of tripropylene glycol diacrylate, 40g of alkenyl fluorinated silicone oil, 0.4g of fluorosilicone surfactant and 1.5g of wetting and leveling agent to 1kg of UV polyurethane emulsion, disperse in a shearing machine, add 36g of photoinitiator 1173, mix well, and obtain a UV coating with antifouling effect.

[0029] Example 2

[0030] (1) Add 16.8g of perfluorooctanoic acid, 20g of double-ended epoxy silicone oil and 0.24g of N,N-dimethylaniline to 300mL of toluene, heat to 100℃, stir and react for 5h, reflux during the reaction, evaporate by rotary evaporation, separate the product by centrifugation to remove solids, collect the oil layer, and obtain perfluoroacid modified double-ended epoxy silicone oil.

[0031] (2) Add 50g of perfluorinated acid modified double-ended epoxy silicone oil, 9g of isocyanate methacrylate and 0.2g of triethylamine to 500mL of dichloromethane. Stir the reaction at 40℃ for 12h. During the reaction, reflux the solution and evaporate it by rotary evaporation. Add the product to water, stir and let it stand to separate the layers. Remove the water layer and dry the oil layer to obtain alkenyl fluorinated silicone oil.

[0032] (3) Add 127g of 1,6-hexanediol diacrylate, 70g of alkenyl fluorinated silicone oil, 0.8g of fluorosilicone surfactant, and 1g of wetting and leveling agent to 1kg of UV polyurethane emulsion, disperse in a shearing machine, add 34g of photoinitiator 1173, mix well, and obtain a UV coating with antifouling effect.

[0033] Example 3

[0034] (1) Add 17.6g of perfluorooctanoic acid, 20g of double-ended epoxy silicone oil and 0.3g of N,N-dimethylaniline to 300mL of toluene, heat to 80℃, stir and react for 7h, evaporate by rotary evaporation, remove solids by centrifugation, collect oil layer to obtain perfluoroacid modified double-ended epoxy silicone oil.

[0035] (2) Add 50g of perfluorinated acid modified double-ended epoxy silicone oil, 11.5g of isocyanate methacrylate and 0.2g of triethylamine to 400mL of dichloromethane. Stir and react at 25℃ for 18h. Rotary evaporate the product and add it to water. After stirring, let it stand to separate into layers. Remove the water layer and dry the oil layer to obtain alkenyl fluorinated silicone oil.

[0036] (3) Add 100g dipropylene glycol diacrylate, 100g alkenyl fluorinated silicone oil, 1.2g fluorosilicone surfactant, and 3g wetting and leveling agent to 1kg UV polyurethane emulsion, disperse in a shearing machine, add 30g photoinitiator 1173, mix well, and obtain a UV coating with antifouling effect.

[0037] Comparative Example 1

[0038] (1) Add 140g of tripropylene glycol diacrylate, 0.4g of fluorosilicone surfactant and 1.5g of wetting and leveling agent to 1kg of UV polyurethane emulsion, disperse in a shearing machine, add 36g of photoinitiator 1173, mix well, and obtain UV coating.

[0039] Comparative Example 2

[0040] (1) Prepare perfluorinated acid modified double-ended epoxy silicone oil according to the method of Example 1.

[0041] (2) Add 140g of tripropylene glycol diacrylate, 40g of perfluorinated acid modified double-ended epoxy silicone oil, 0.4g of fluorosilicone surfactant, and 1.5g of wetting and leveling agent to 1kg of UV polyurethane emulsion, disperse in a shearing machine, add 36g of photoinitiator 1173, mix well, and obtain UV coating.

[0042] Comparative Example 3

[0043] (1) Add 5.77 g of octanoic acid, 20 g of double-ended epoxy silicone oil and 0.32 g of N,N-dimethylbenzylamine to 250 mL of toluene, heat to 110 °C, stir and react for 4 h, reflux during the reaction, evaporate by rotary evaporation, centrifuge the product to remove solids, collect the oil layer, and obtain octanoic acid modified double-ended epoxy silicone oil.

[0044] (2) Add 35.2g of octanoic acid modified double-ended epoxy silicone oil, 10.2g of isocyanate methacrylate and 0.15g of triethylamine to 400mL of dichloromethane. Stir and react at 30℃ for 18h. Rotary evaporate the product and add it to water. After stirring, let it stand to separate into layers. Remove the water layer and dry the oil layer to obtain alkenyl silicone oil.

[0045] (3) Add 140g of tripropylene glycol diacrylate, 40g of alkenyl silicone oil, 0.4g of fluorosilicone surfactant and 1.5g of wetting and leveling agent to 1kg of UV polyurethane emulsion, disperse in a shearing machine, add 36g of photoinitiator 1173, mix well, and obtain a UV coating with antifouling effect.

[0046] Comparative Example 4

[0047] (1) Prepare perfluorinated acid modified double-ended epoxy silicone oil according to the method of Example 1.

[0048] (2) Add 50g of perfluorinated acid modified double-ended epoxy silicone oil, 5.96g of acryloyl chloride and 6.65g of triethylamine to 400mL of dichloromethane. Stir and react at 30℃ for 18h. Evaporate by rotary evaporation. Add the product to water. Stir and let stand to separate the layers. Remove the water layer and dry the oil layer to obtain alkenyl fluorinated silicone oil.

[0049] (2) Add 140g of tripropylene glycol diacrylate, 40g of alkenyl fluorinated silicone oil, 0.4g of fluorosilicone surfactant and 1.5g of wetting and leveling agent to 1kg of UV polyurethane emulsion, disperse in a shearing machine, add 36g of photoinitiator 1173, mix well, and obtain UV coating.

[0050] Comparative Example 5

[0051] (1) The method for preparing fluorosilyl acrylates, with the structural formula [not specified], is described in the journal article "Synthesis and Performance Characterization of Fluorosilicone Ester Crosslinked Acrylic Resins" published in Volume 45, Issue 8, August 2015, *Coatings Industry*. .

[0052] (2) Add 140g of tripropylene glycol diacrylate, 40g of fluorosilyl acrylate, 0.4g of fluorosilicone surfactant and 1.5g of wetting and leveling agent to 1kg of UV polyurethane emulsion, disperse in a shearing machine, add 36g of photoinitiator 1173, mix well, and obtain UV coating.

[0053] The coating was left at room temperature for 30 days to observe its storage stability.

[0054] The UV coating was sprayed onto the surface of a tinplate substrate and cured for 40 seconds in a 2kW UV curing machine. The water contact angle was tested according to GB / T30693-2014 standard. The impact resistance of the coating film was tested according to GB / T 1732-2020 standard. The salt spray resistance was tested according to GB / T1771-2007 standard.

[0055] Table 1 Performance of Coatings

[0056]

[0057] Comparative Example 1 has a low water contact angle and a large surface energy, which is not conducive to improving the waterproof and anti-pollution properties of the paint film. It also has low impact resistance and poor salt spray corrosion resistance.

[0058] In Examples 1-3, alkenyl fluorinated silicone oil was added to the polyurethane UV coatings. This oil contains urethane groups, which have good compatibility with the polyurethane molecular chain. Furthermore, under the action of fluorosilicone surfactants, the alkenyl fluorinated silicone oil can be uniformly dispersed in the polyurethane emulsion, preventing emulsion stratification and exhibiting good storage stability. The alkenyl fluorinated silicone oil contains hydrophobic, low surface energy polysiloxane molecular chains and perfluoroalkyl groups, which are uniformly dispersed in the polyurethane emulsion and coating film, significantly reducing the surface energy of the coating film and lowering the water contact angle. This improves waterproof and anti-fouling performance, and also significantly enhances salt spray resistance. Moreover, the alkenyl fluorinated silicone oil contains alkenyl groups, which can undergo alkenyl crosslinking polymerization with UV polyurethane and reactive diluents, thereby introducing flexible polysiloxane molecular chains into the polyurethane coating film, improving the impact resistance and flexibility of the coating film.

[0059] Compared with Example 1, the perfluorinated acid modified double-ended epoxy silicone oil in Comparative Example 2 does not contain urethane groups, resulting in poor compatibility with polyurethane emulsions. The silicone oil is prone to precipitating on the coating layer, affecting the storage stability and mechanical properties such as impact resistance of the coating. Furthermore, the perfluorinated acid modified double-ended epoxy silicone oil does not contain alkenyl groups, making it unable to undergo alkenyl crosslinking polymerization with UV polyurethane and reactive diluents, which affects the impact resistance and salt spray resistance of the coating film.

[0060] The alkenyl silicone oil in Comparative Example 3 does not contain fluorine, and the water contact angle and surface energy of the coating film are low, resulting in poor waterproof, anti-pollution, and salt spray resistance.

[0061] Comparative Example 4 utilizes the hydroxyl groups of perfluorinated modified double-ended epoxy silicone oil to undergo esterification with acryloyl chloride. The resulting alkenyl fluorinated silicone oil does not contain urethane groups and has poor compatibility with polyurethane emulsions. The silicone oil is prone to precipitate on the coating layer, affecting the storage stability and mechanical properties of the coating, such as impact resistance.

[0062] The fluorosilyl acrylate in Comparative Example 5 is a small molecule compound that does not contain polysiloxane polymer chains, and the impact resistance and flexibility of the coating film are significantly lower than those in Example 1.

[0063] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A UV coating with anti-fouling effect, characterized in that, The UV coating comprises a UV polyurethane emulsion, an active diluent, a photoinitiator, an alkenyl fluorinated silicone oil, a surfactant, and a wetting and leveling agent in a ratio of 100g:(10-14)g:(3-3.6)g:(4-10)g:(0.04-0.12)g:(0.1-0.3)g. The surfactant is a fluorosilicone surfactant; The preparation method of the alkenyl fluorinated silicone oil includes: adding perfluoroacid modified double-ended epoxy silicone oil, isocyanate methacrylate and triethylamine to dichloromethane, stirring and reacting, rotary evaporation, adding the product to water, stirring and allowing it to stand and separate into layers, removing the water layer, drying the oil layer to obtain alkenyl fluorinated silicone oil. The preparation method of the perfluorinated acid modified double-ended epoxy silicone oil includes: adding perfluorinated acid, double-ended epoxy silicone oil and catalyst to toluene, stirring and reacting, rotary evaporation, centrifuging the product, collecting the oil layer, and obtaining perfluorinated acid modified double-ended epoxy silicone oil.

2. The UV coating with antifouling effect according to claim 1, characterized in that, The reactive diluents include tripropylene glycol diacrylate, dipropylene glycol diacrylate, and 1,6-hexanediol diacrylate; the photoinitiator includes 1173.

3. The UV coating with antifouling effect according to claim 1, characterized in that, The ratio of the perfluorinated acid-modified double-ended epoxy silicone oil, isocyanate methacrylate, and triethylamine is 100g:(18-23)g:(0.3-0.4)g.

4. The UV coating with antifouling effect according to claim 1, characterized in that, The reaction was carried out at 25-40°C for 12-18 hours.

5. The UV coating with antifouling effect according to claim 1, characterized in that, In the preparation method of the perfluorinated acid modified double-ended epoxy silicone oil, the reaction is carried out at 80-110℃ for 4-7 hours.

6. The UV coating with antifouling effect according to claim 1, characterized in that, The ratio of perfluorinated acid, double-ended epoxy silicone oil, and catalyst is (83-88) g: 100 g: (1.2-1.6) g.

7. The UV coating with antifouling effect according to claim 1, characterized in that, The perfluoroacid is C n F 2n+ 1COOH, n is 2-10.

8. The UV coating with antifouling effect according to claim 1, characterized in that, The catalyst is N,N-dimethylaniline or N,N-dimethylbenzylamine.

9. A method for preparing a UV coating with antifouling effect as described in any one of claims 1-8, characterized in that, The preparation method includes: adding an active diluent, an alkenyl fluorinated silicone oil, a surfactant, and a wetting and leveling agent to a UV polyurethane emulsion, dispersing it in a shear mill, adding a photoinitiator, and mixing it to obtain a UV coating with antifouling effect.

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