Antifouling auxiliary agent and application thereof in ultraviolet curing coating

Abstract

The invention discloses an anti-fouling auxiliary agent and an application thereof in an ultraviolet curing coating. The anti-fouling auxiliary agent is specifically fluorine-containing light-cured hyperbranched polyester containing acrylic ester. Under the irradiation of ultraviolet light, double bonds of acrylate in the assistant structure can be crosslinked and cured with double bonds of acrylate resin and acrylate monomers in the coating to form a coating with excellent hydrophobic and oleophobic properties, so that the coating has an excellent anti-fouling effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultraviolet light-curing antifouling materials, and relates to an antifouling auxiliary agent and the application thereof in ultraviolet light-curing coatings, and specifically to a preparation method of a fluorine-containing photocurable hyperbranched polyester containing an acrylate structure and the application thereof as an antifouling auxiliary agent in ultraviolet light-curing coatings. Background Art

[0002] Ultraviolet curing coatings (UV coatings) have been widely used in the hardening of plastic substrate surfaces of electronic products such as mobile phones, tablet computers, optical lenses, machine control panels, GPS panels, etc., due to their advantages of high efficiency, energy saving, environmental protection, economy, etc., as well as the excellent scratch resistance, chemical resistance, high gloss and other characteristics of their coating films, thereby improving the hardness, transparency, wear resistance, impact resistance and other properties of the plastic substrates. However, during the use of these electronic products, the screen surface is easily left with fingerprints, skin oils, ink stains and other stains, and the stains are difficult to remove, thereby reducing the surface transparency and affecting the practicality and aesthetics. In particular, in recent years, based on the popularity of 3C products such as touch-screen mobile phones, computers, and televisions, in addition to the hardness, transparency, and wear resistance of the coating, higher requirements have been put forward for the anti-fouling performance of the coating.

[0003] With the rise and development of fluorine chemistry, people gradually realized the special properties of fluorine-containing compounds / resins. Fluorine has the highest electronegativity, and the CF bond formed by it and carbon atoms is the shortest and has low polarizability. Therefore, the fluorine atoms in the fluorine-containing polymer chain repel each other and are densely wrapped on the outside of the main chain to form a dense spiral shielding layer. In addition, the bond energy of the CF bond is relatively high, and it is difficult for general ultraviolet radiation to break the CF bond and destroy the resin structure. It is this special structural feature that gives fluorine-containing resins excellent special properties such as low surface tension, water and oil resistance, chemical stability and weather resistance. However, fluorine-containing compounds have the disadvantage of high cost, so the method of using cheap and low-surface-energy organosilicon compounds to cooperate with fluorine-containing compounds to reduce surface tension, improve hydrophobic and oleophobic effects, and thus achieve anti-fouling functions has attracted widespread attention.

[0004] Chinese patent CN103665022A discloses an anti-fouling auxiliary agent of perfluoropolyether alkoxysilane, but the auxiliary agent is synthesized by a two-step synthesis method, the first step adopts flammable solvent ether, and the expensive perfluoropolyether acyl fluoride is reacted with allylamine to obtain allyl perfluoropolyether amide, and the synthesis time is long, and the solvent needs to be removed before the second step reaction. The second step reaction adopts dichloromethane, a low-boiling solvent with large toxicity, and requires a more expensive platinum catalyst. The above-mentioned product allyl perfluoropolyether amide is reacted with trimethoxysilane, and the reaction time is long, and the solvent needs to be removed. However, despite such a complicated synthesis process, the expensive final product obtained is only a compound with perfluoropolyether group and trimethoxysilane, which does not have a photocurable group at all, so it cannot be photocrosslinked with the resin and monomer in the photocurable coating system. In addition, because the product has a trimethoxysilane structure, it is unstable to water and easily hydrolyzed, so there is a storage stability problem. On the other hand, the patent does not provide the use effect of the synthetic product in anti-fouling coatings.

[0005] Chinese patent CN104755514A discloses a kind of antifouling coating composition, which includes fluorine-containing hyperbranched polymer and siloxane oligomer.But fluorine-containing hyperbranched polymer and siloxane oligomer need to be prepared separately, and the former also needs to carry out desolventizing and vacuum drying steps, and the operation is complicated.The preparation of siloxane oligomer is prepared by hydrolysis of methacryloxypropyltriethoxysilane under acidic conditions in ethanol solution. Although the preparation process is simple, it is difficult to obtain oligomers of expected molecular weight. If the operation is improper, crosslinking will occur.In addition, the fluorine-containing hyperbranched polymer mentioned in the invention is only a multi-functional random binary copolymer containing double bonds in the side chain, and its fluorine content is relatively low, because its fluorine raw material is only 2-(perfluorohexyl) ethyl acrylate containing 6 fluorine atoms, the fluorine-containing chain segment is relatively short, so the hydrophobic and oleophobic effect is low, and the polymer does not have the structural regularity of hyperbranched polymer, so the viscosity is relatively high, which will cause poor compatibility with other components in the coating system and affect the coating effect.

[0006] Chinese patent CN103237848B discloses a photocurable composition for coating containing a fluorine-containing hyperbranched polymer with excellent anti-fingerprint performance. However, the preparation of the fluorine-containing hyperbranched polymer requires desolventization, precipitation and vacuum drying, which is complicated to operate and has a low yield. In addition, the hyperbranched polymer is prepared by free radical polymerization, and a saturated fluorine-containing polymer is obtained, and there is no unsaturated group that can be UV-cured, such as an acrylate double bond. Therefore, in the photocurable composition, it cannot react with other polyfunctional photocurable monomers containing unsaturated double bonds, but only exists as a free auxiliary agent. In addition, the polymer does not have the structural regularity of a hyperbranched polymer, so the viscosity is high, which will cause poor compatibility with other components in the coating system and affect the coating effect.

[0007] China CN107266687A discloses an anti-fouling agent with a fluorosilicone photocurable hyperbranched polyester structure having an acrylate structure. However, the fluorine-containing structure in this patent comes from a perfluoroalkyl group, and its only feature is that because the fluorine-containing part is relatively high, its surface tension is very low, and it is easy to migrate to the coating surface after photocuring, and has anti-fouling properties. However, since there is no partially hydrophilic polyether segment introduced into its structure, it has no surface activity, which leads to poor compatibility with other photocurable resins or photocurable monomers in the system, and the coating is prone to leveling problems. Summary of the invention

[0008] The purpose of the present invention is to overcome the defects of the prior art and provide an anti-fouling agent and its application in ultraviolet light-curing coatings. The anti-fouling agent contains a photocurable hyperbranched polyester with a fluorinated polyether structure of an acrylate structure, so as to effectively improve the hydrophobic and oleophobic properties of the photocured coating on the surface of a transparent plastic substrate, so as to achieve excellent anti-fouling effect.

[0009] The purpose of the present invention can be achieved by the following scheme:

[0010] In a first aspect, the present invention provides an antifouling agent, wherein the antifouling agent is a fluorine-containing photocurable hyperbranched polyester containing an acrylate structure; the structure of the antifouling agent is shown in Formula I:

[0011]

[0012] R F The structure is shown in Formula II:

[0013]

[0014] Wherein, R is a straight chain or branched alkyl group having 6-10 carbon atoms, or R is a cycloalkane group containing 1-2 5-membered rings or 6-membered rings, m is an integer of 5-10; n is an integer of 2-10, and P is an integer of 1-5.

[0015] The fluorine-containing photocurable hyperbranched polyester containing an acrylate structure of the present invention can undergo polymerization reaction with acrylic resin and monomers in the ultraviolet light-curable coating under ultraviolet light irradiation and in the presence of a photoinitiator to crosslink and cure, thereby forming a super hydrophobic and oleophobic coating film on the surface of the plastic substrate.

[0016] As an embodiment of the present invention, the cycloalkane group containing 1-2 5-membered rings or 6-membered rings. The 5-membered rings may be cyclopentane or cyclopentane substituted with 1-3 methyl or ethyl groups. The 6-membered rings may be cyclohexane or cyclohexane substituted with 1-3 methyl or ethyl groups.

[0017] In a second aspect, the present invention provides a method for preparing the anti-fouling agent, the method comprising the following steps:

[0018] S1, under the protection of an inert gas (nitrogen, argon or helium, preferably nitrogen) and in the presence of a catalyst, a perfluoropolyether diol and a diisocyanate react to obtain a perfluoropolyether compound 1 having isocyanate groups at both ends;

[0019] S2, adding hydroxy acrylate to the perfluoropolyether compound 1, reacting in the presence of an inhibitor and a catalyst to obtain a perfluoropolyether compound 2 having an isocyanate group at one end and an acrylate double bond at the other end;

[0020] S3, adding hyperbranched polyester polyol (HBP for short) to the perfluoropolyether compound 2, reacting in the presence of a solvent, an inhibitor and a catalyst to obtain a solution of a fluorine-containing photocurable hyperbranched polyester containing an acrylate structure, that is, an anti-fouling additive.

[0021] As an embodiment of the present invention, in step S1, the molecular formula of the perfluoropolyether diol is as follows:

[0022] HO(CH2CH2O) p CH2CF2O(CF2CF2O) n (CF2O) m CF2CH2O(CH2CH2O) p H; wherein m is an integer of 5-10; n is an integer of 2-10, and P is an integer of 1-5.

[0023] As an embodiment of the present invention, the diisocyanate includes one of hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, cyclohexyl dimethylene diisocyanate, norbornane diisocyanate, and methylcyclohexane diisocyanate. Preferably, it is one of hexamethylene diisocyanate, isophorone diisocyanate, and 1,4-cyclohexane diisocyanate, and more preferably one of hexamethylene diisocyanate and isophorone diisocyanate. More preferably, the diisocyanate is hexamethylene diisocyanate.

[0024] As an embodiment of the present invention, in step S1, the theoretical molar ratio of diisocyanate to perfluoropolyether diol is 2:1.

[0025] As an embodiment of the present invention, in step S2, the hydroxy acrylate includes one of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate, preferably hydroxyethyl acrylate.

[0026] As an embodiment of the present invention, in step S2, the theoretical molar number of the hydroxy acrylate is the same as that of the perfluoropolyether diol in step S1.

[0027] As an embodiment of the present invention, in step S3, the structure of the hyperbranched polyester polyol is as shown in Formula III:

[0028]

[0029] As an embodiment of the present invention, in step S3, the theoretical molar number of hydroxyl groups of the hyperbranched polyester polyol (HBP for short) is the same as the theoretical molar number of the hydroxyl acrylate in step S2.

[0030] As an embodiment of the present invention, the catalyst is selected from one of dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate, preferably dibutyltin dilaurate.

[0031] As an embodiment of the present invention, the polymerization inhibitor is selected from one of p-hydroxyanisole, hydroquinone, p-tert-butylcatechol, 2,4-di-tert-butylphenol, phenothiazine, etc., preferably p-hydroxyanisole.

[0032] As an embodiment of the present invention, the solvent is selected from toluene, ethyl acetate, butyl acetate, butanone, preferably toluene.

[0033] As an embodiment of the present invention, in steps S1, S2 and S3, the reaction temperature is 65-70°C and the reaction time is 2-4h.

[0034] In some implementation examples, in step S1, the reaction temperature is 65-70°C and the reaction time is 3 hours. In step S2, the reaction temperature is 65-70°C and the reaction time is 2-3 hours. In step S3, the reaction temperature is 65-70°C and the reaction time is 3-4 hours.

[0035] In some specific embodiments, the fluorine-containing photocurable hyperbranched polyester containing an acrylate structure is prepared by a method comprising the following steps:

[0036] S1', under nitrogen protection, using dibutyltin dilaurate as a catalyst, perfluoropolyether diol and diisocyanate as raw materials, react at a temperature of 65-70°C for 3 hours to obtain a perfluoropolyether compound with isocyanate groups at both ends; wherein the theoretical molar ratio of diisocyanate to perfluoropolyether diol is 2:1.

[0037] S2', adding the polymerization inhibitor p-hydroxyanisole, the catalyst dibutyltin dilaurate, and the hydroxy acrylate with the same theoretical molar number as the perfluoropolyether diol to the reactants of step S1, and reacting at 65-70° C. for 2-3 hours to react the hydroxyl group with an isocyanate group to obtain a perfluoropolyether compound having an isocyanate group at one end and an acrylate double bond at the other end.

[0038] S3', add toluene, polymerization inhibitor p-hydroxyanisole, catalyst dibutyltin dilaurate, and hyperbranched polyester polyol to the reaction solution of step S2. React at 65-70°C for 3-4 hours to obtain a toluene solution of fluorine-containing photocurable hyperbranched polyester containing an acrylate structure. The theoretical molar number of hydroxyl groups in the hyperbranched polyester polyol is the same as the theoretical molar number of hydroxyl acrylate in step S2.

[0039] In a third aspect, the present invention further provides a use of the anti-fouling additive of the present invention in ultraviolet light curing coatings.

[0040] As an embodiment of the present invention, the antifouling agent is used to prepare an antifouling UV-curing coating, and the amount of the antifouling agent added to the UV-curing coating is 0.2-3.0 wt %. In some implementation examples, the amount of the antifouling agent added to the UV-curing coating is 1.0-3.0 wt %. In this case, no other antifouling agent is used.

[0041] As an embodiment of the present invention, the system also contains other antifouling agents. For example, Shin-Etsu antifouling agent KY1203. The antifouling agent and Shin-Etsu antifouling agent KY1203 can be used in conjunction to prepare an antifouling UV-curing coating. The total amount of the antifouling agent and Shin-Etsu antifouling agent KY1203 added to the UV-curing coating is 1.0-3.0wt%. Preferably, the weight ratio of the antifouling agent and Shin-Etsu antifouling agent KY1203 is 1:1-1.2.

[0042] As an embodiment of the present invention, the system further contains other anti-fouling agents, such as acrylic anti-fouling and wear-resistant agent Lencolo 3007A. In the system, the weight ratio of the anti-fouling agent to the acrylic anti-fouling and wear-resistant agent Lencolo 3007A is 1:5-10.

[0043] As an embodiment of the present invention, the unsaturated double bonds of the acrylate in the anti-fouling agent are photo-crosslinked with the acrylic resin and acrylate monomer in the photocurable coating under light conditions.

[0044] As some implementation examples, the UV curable coating includes the following components in parts by weight:

[0045]

[0046]

[0047] Furthermore, the acrylic oligomer may be 50 parts. In some implementation examples, the acrylic oligomer is at least one of 6195 resin from Changxing Company and CN9010 resin from Sartomer Company.

[0048] Furthermore, the acrylic monomer may be at least one of dipentaerythritol hexaacrylate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane triacrylate, and 1,6-hexanediol diacrylate.

[0049] Furthermore, the photoinitiator may be at least one of benzophenone and 1-hydroxyphenylcyclohexanone.

[0050] Furthermore, the auxiliary agent includes at least one of a polymerization inhibitor, a leveling agent, and a dispersant. The polymerization inhibitor includes one of p-hydroxyanisole, hydroquinone, p-tert-butylcatechol, 2,4-di-tert-butylphenol, phenothiazine, etc., preferably p-hydroxyanisole.

[0051] Furthermore, the solvent is selected from at least one of ethyl acetate, butyl acetate, n-butanol, isopropanol, and ethylene glycol methyl ether acetate.

[0052] As an embodiment of the present invention, the UV-curable coating is used for the surface layer of a transparent plastic substrate, and the transparent plastic substrate includes at least one of PET, PMMA, PC, and PVC.

[0053] The photocurable hyperbranched polyester of the fluorinated polyether of acrylate in the present invention has the structural characteristics that the fluorinated part is located at the end of the hyperbranched polyester. Since the surface energy of the fluorinated polyether chain segment is extremely low, the fluorinated polyether chain segment is very easy to migrate to the surface of the coating to form a surface with very low surface energy, so it has excellent hydrophobic, oleophobic and anti-fouling effects. Because the hyperbranched structure contains many unsaturated double bonds of acrylate that can be photocured, it can be photo-crosslinked with the acrylic resin and acrylate monomer in the photocurable coating under light conditions. Therefore, these hydrophobic and oleophobic fluorinated polyether chain segments are firmly fixed on the coating, so that the coating has a lasting anti-fouling effect. Moreover, the photocurable hyperbranched polyester containing fluorinated polyether contains several forms of polyether segments, specifically two hydrophilic ethoxy segments with a structural formula of (CH2CH2O)p, 50% fluorinated ethoxy segments with a structural formula of CH2CF2O, fully fluorinated ethoxy segments with a structural formula of (CF2CF2O)n, and fully fluorinated methoxy segments with a structural formula of (CF2O)m. Because of these structures, R FPart of it has a structure similar to that of a nonionic surfactant, so that the photocurable hyperbranched polyester of the fluorinated polyether of the acrylate of the present invention has a property similar to that of a nonionic surfactant, which can make it added as an auxiliary agent to the photocurable coating and have good compatibility with acrylate photocurable resins and monomers. Due to having a certain surface activity, it also contains a lot of fluorinated structural units, so the surface tension of the coating can be effectively reduced, and the leveling property of the coating can be made good, that is, it can play the role of a part of leveling agent. The fluorinated structural part in CN107266687A comes from perfluoroalkyl, and its characteristic is that because the fluorinated part is higher, its surface tension is very low, and it is easy to migrate to the coating surface after photocuring, and has anti-fouling performance. However, since the polyether segment with partial hydrophilicity is not introduced in its structure, it does not have surface activity, which will lead to poor compatibility with other photocurable resins or photocurable monomers in the system, and the coating is prone to leveling problems.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] 1. The fluorine-containing photocurable hyperbranched polyester with an acrylate structure designed and synthesized in the present invention has a hyperbranched structure, so it has high functionality; and the photocurable hyperbranched polyester has many fluorine-containing polyether segments with low surface energy. This structure enables it to be quickly cross-linked and cured with acrylate resins and acrylate monomers to form a dense network when used in photocurable coatings.

[0056] 2. The fluorine-containing photocurable hyperbranched polyester with an acrylate structure designed and synthesized in the present invention has a very low surface energy of fluorine atoms, which makes it easy for the fluorine-containing polyether chain segments to migrate to the surface and densely distribute on the coating surface, thereby effectively improving the hydrophobic and oleophobic properties of the coating and achieving an anti-fouling effect; it also has the function of a partial leveling agent.

[0057] 3. Since the fluorine-containing photocurable hyperbranched polyester of the acrylic ester in the present invention forms a cross-linked network with the resin and monomer in the coating system after photocuring, even if the fluorine-containing chain segment is partially distributed on the coating surface, it will not be removed due to external friction or solvent wiping and lose its anti-fouling performance, thereby further enhancing the anti-fouling effect.

[0058] 4. The fluorine-containing photocurable hyperbranched polymer of acrylate in the present invention can be synthesized by a one-pot method, which is simple and easy to realize industrial production. In addition, no additional post-processing process such as solvent removal is required, and it can be directly used as an anti-fouling additive in the form of a solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0060] Figure 1 This is an infrared spectrum analysis chart of the fluorine-containing photocurable hyperbranched polyester containing acrylate in Example 1. DETAILED DESCRIPTION

[0061] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The following examples are implemented on the premise of the technical solution of the present invention, provide detailed implementation methods and specific operation processes, and will help those skilled in the art to further understand the present invention. It should be pointed out that the protection scope of the present invention is not limited to the following embodiments, and several adjustments and improvements made under the premise of the concept of the present invention all belong to the protection scope of the present invention.

[0062] Preparation method of fluorine-containing photocurable hyperbranched polyester of acrylate:

[0063] A perfluoropolyether diol Flurolink E10H from Solvay Specialty Polymers of Italy is used, and its structural formula is as follows:

[0064] HO(CH2CH2O) p CH2CF2O(CF2CF2O) n (CF2O) m CF2CH2O(CH2CH2O) p H, m = 6, n = 5, p

[0065] =2.

[0066] The hyperbranched polyester polyol used was P500 produced by Swedish Pasto Company, and the hydroxyl value was 592.2 mgKOH / g.

[0067] Synthesis example 1

[0068] In a 100 ml four-necked flask equipped with magnetic stirring, a serpentine condenser, and a thermometer, 3.48 g of hexamethylene diisocyanate (0.02 mol), 16.44 g of perfluoropolyether diol Flurolink E10H (0.01 mol), and 0.002 g of dibutyltin dilaurate were added under nitrogen protection, and the mixture was reacted at 65° C. for 3 hours. Then, 0.04 g of p-hydroxyanisole, 0.002 g of dibutyltin dilaurate, and 1.16 g of hydroxyethyl acrylate were added, and the mixture was reacted at 65° C. for 3 hours. Then add 22g toluene, 0.04g p-hydroxyanisole, 0.002g dibutyltin dilaurate, 0.99g hyperbranched polyester polyol (hydroxyl value 592.2mgKOH / g, 0.01mol-OH), react at 65°C for 4 hours to obtain fluorine-containing photocurable hyperbranched polyester with a solid content of 50% acrylate. Because it is used as an anti-fouling agent, the amount added is generally very small, so it is diluted with ethyl acetate to 20% solid content as the final product, named anti-fouling agent A.

[0069] The obtained product was subjected to rotary evaporation to remove the solvent, and then dried in vacuum at 40°C for 24 hours. The obtained sample was analyzed by infrared spectroscopy ( Figure 1 ). 1720cm -1 The carbonyl absorption peaks at 1406 cm-1 come from hyperbranched polyester and acrylate. -1 =CH in-plane bending vibration absorption peak from acrylate; 1690cm -1 is the carbonyl absorption peak of the carbamate bond, 1200 cm -1 It is the stretching vibration absorption peak of COC of hyperbranched polyester. 1093cm -1 is the stretching vibration absorption peak from the CF bond; 810cm -1 It is the absorption peak of the unsaturated double bond C=C of acrylate. Therefore, infrared spectrum analysis shows that the product is a fluorine-containing photocurable hyperbranched polyester of acrylate.

[0070] Synthesis example 2

[0071] In a 100 ml four-necked flask equipped with magnetic stirring, a snake-shaped condenser, and a thermometer, 4.44 g of isophorone diisocyanate (0.02 mol), 16.44 g of perfluoropolyether diol Flurolink E10H (0.01 mol), and 0.002 g of dibutyltin dilaurate were added under nitrogen protection, and the mixture was reacted at 65° C. for 3 hours. Then, 0.04 g of p-hydroxyanisole, 0.002 g of dibutyltin dilaurate, and 1.16 g of hydroxyethyl acrylate were added, and the mixture was reacted at 65° C. for 3 hours. Then add 22g toluene, 0.04g p-hydroxyanisole, 0.002g dibutyltin dilaurate, 0.99g hyperbranched polyester polyol (hydroxyl value 592.2mgKOH / g, 0.01mol-OH), react at 65°C for 4 hours to obtain fluorine-containing photocurable hyperbranched polyester with a solid content of 50% acrylate. Because it is used as an anti-fouling agent, the amount added is generally very small, so it is diluted with ethyl acetate to 20% solid content as the final product. Named anti-fouling agent B.

[0072] Application in light-curing coatings

[0073] Add a certain amount of synthetic antifouling agent A (solid content 20%), antifouling agent B (solid content 20%), commercially available fluorinated acrylate anti-fingerprint agent KY1203 (solid content 20%) or fluorinated modified acrylate antifouling and wear-resistant agent Lencolo 3007A (solid content 50%, diluted to 20% with ethyl acetate before use) to the UV light-curing hard coating of the formula shown in Table 1, and stir magnetically for 30 minutes at room temperature to mix evenly. Use PET as the substrate, use a No. 10 rod roller to coat, dry at 65°C for 2 minutes, and then perform UV light curing to obtain a plate, with a curing energy of 300mJ / cm2 .

[0074] Table 1. UV light curing hard coating formula

[0075]

[0076] Performance Testing

[0077] 1. Anti-fouling evaluation: water contact angle and oil pen

[0078] 1.1. Initial water contact angle: measured by DSA25 standard contact angle meter (Krüss, Germany), measured three times at different positions, and the results were averaged.

[0079] 1.2. Oil-resistant pen wipe times: Draw a horizontal line on the same position of the coating with an oil-resistant pen, wipe it with a dust-free cloth, test it repeatedly, and record the number of times the writing is completely wiped off.

[0080] 2. Anti-fingerprint performance test: Press the fingerprint on the coating, wipe it with a dust-free cloth, and observe the fingerprint residue; ○ means that the fingerprint is easy to wipe and there is no fingerprint residue after wiping, and the anti-fouling effect is still there after wiping more than 50 times, and △ means that it can be wiped between 20 and 30 times and still has an effect. × means that the fingerprint can be wiped but it is difficult to wipe off, and the anti-fouling effect is not good.

[0081] 3. Durable antifouling - water contact angle after wiping with steel wool: The water contact angle after wiping 100 times with 0000# steel wool at 1000 grams of force (measured by DSA25 standard contact angle meter (Krüss, Germany), measured three times at different positions, and the results were averaged.

[0082] The coating components and their test results are shown in Table 2:

[0083] Table 2 Application of antifouling additives in light-curing hard coatings

[0084]

[0085] It can be seen from Examples 1 and 4 in Table 2 that when 0.5% of antifouling agent A or B is added to the UV-cured hard coating and applied to the surface of the PET substrate, the initial water contact angle of the coating on the substrate surface after light curing exceeds 100 degrees; but the anti-fingerprint performance is average. The number of oil-resistant pens is more than 100 times. The water contact angle of 0000# steel wool after wiping 100 times under a load of 1000 grams is also around 100 degrees, which shows that the coating has a good continuous antifouling performance.

[0086] It can be seen from Examples 2, 3, 5, and 6 that increasing the amount of additive A or B to 1.0% and 1.5% improves all properties. In particular, the water contact angle can reach more than 110 degrees, and after wiping with steel wool, the water contact angle exceeds 105 degrees, and even reaches 110 degrees, and the anti-fingerprint performance is also very good. From an economic point of view, 1% addition is sufficient.

[0087] Comparative Examples 1-3 are the results of adding 1%, 1.5% and 2.0% of the commercially available Japanese Shin-Etsu fluorinated acrylate anti-fingerprint additive KY-1203, respectively. The water contact angle of 1.0% does not meet the requirement of 100 degrees, and the oil pen does not meet the requirement of more than 100 times. Moreover, the anti-fingerprint property is average. After adding 1.5%, it can basically meet the requirements, but the steel wool wiping performance is slightly lacking. After adding 2%, various properties can reach the level of 1% addition of self-synthesized additives A and B, that is, the initial water contact angle is close to 110 degrees, the number of oil-resistant pens is more than 110 times, and after steel wool wiping, the water contact angle exceeds 105 degrees. However, the coating has poor leveling properties.

[0088] In Examples 7 and 8, 0.5% of additives A and B were added respectively, and 0.5% of KY-1203 was added to each of them. The UV light-cured coating had a very good anti-fouling effect, indicating that the anti-fouling additives A and B had a very good synergistic effect with Shin-Etsu's anti-fouling additive KY1203.

[0089] Comparative Examples 4-6 respectively added 2%, 5% and 10% of the commercially available fluorine-modified acrylate anti-fouling and wear-resistant additive Lencolo 3007A, and the anti-fouling effects were all unsatisfactory.

[0090] In Examples 9 and 10, 0.5% of the additive A was added, and then 2% and 5% of the commercially available fluorine-modified acrylic ester anti-fouling and wear-resistant additive Lencolo 3007A were added, respectively. The effect of adding only 5% was acceptable. However, compared with Example 7 in which KY-1203 was added, the effect was poor. However, the amount of Lencolo 3007A was large, while KY-1203 was effective when only 0.5% was added. This shows that the synergistic effect of the acrylic ester fluorine-containing photocurable hyperbranched polyester anti-fouling additive A and KY-1203 is better than Lencolo 3007A.

[0091] It should be noted that the hyperbranched fluorinated acrylate antifouling agent in this study can be used in addition to polyester (PET) and can also be used in the surface coating of various transparent plastic substrates such as PMMA, PC, PVC, etc. to meet different needs. The hyperbranched fluorinated acrylate antifouling agent has a simple synthesis process and readily available raw materials, and has good application value.

[0092] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. An anti-fouling agent, characterized in that: The anti-fouling agent is a fluorine-containing photocurable hyperbranched polyester containing an acrylate structure; the structure of the anti-fouling agent is shown in Formula I: R F The structure is shown in Formula II: Wherein, R is a straight chain or branched alkyl group having 6-10 carbon atoms, or R is a cycloalkane group containing 1-2 5-membered rings or 6-membered rings, m is an integer of 5-10; n is an integer of 2-10, and P is an integer of 1-5.

2. A method for preparing the antifouling agent as claimed in claim 1, characterized in that: The preparation method comprises the following steps: S1. Under the protection of an inert gas and in the presence of a catalyst, a perfluoropolyether diol and a diisocyanate react to obtain a perfluoropolyether compound 1 having isocyanate groups at both ends; S2, adding hydroxy acrylate to the perfluoropolyether compound 1, reacting in the presence of an inhibitor and a catalyst to obtain a perfluoropolyether compound 2 having an isocyanate group at one end and an acrylate double bond at the other end; S3, adding hyperbranched polyester polyol to the perfluoropolyether compound 2, reacting in the presence of a solvent, an inhibitor and a catalyst to obtain a solution of fluorine-containing photocurable hyperbranched polyester containing an acrylate structure, that is, an anti-fouling auxiliary agent.

3. The preparation method according to claim 2, characterized in that: In step S1, the molecular formula of the perfluoropolyether diol is as follows: HO(CH2CH2O) p CH2CF2O(CF2CF2O) n (CF2O) m CF2CH2O(CH2CH2O) p H; wherein m is an integer of 5-10; n is an integer of 2-10, and P is an integer of 1-5.

4. The preparation method according to claim 2, characterized in that: The diisocyanate includes one of hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, cyclohexyl dimethylene diisocyanate, norbornane diisocyanate, and methylcyclohexane diisocyanate.

5. The preparation method according to claim 2, characterized in that: The hydroxy acrylate includes one of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate.

6. The preparation method according to claim 2, characterized in that: The catalyst is selected from one of dibutyltin dilaurate, stannous octoate and dibutyltin diacetate; the inhibitor is selected from one of p-hydroxyanisole, hydroquinone, p-tert-butylcatechol, 2,4-di-tert-butylphenol and phenothiazine; the solvent is selected from toluene, ethyl acetate, butyl acetate and butanone.

7. The preparation method according to claim 2, characterized in that: In steps S1, S2 and S3, the reaction temperature is 65-70°C and the reaction time is 2-4h.

8. Use of the antifouling agent according to claim 1, or the antifouling agent obtained by the method according to any one of claims 2 to 7 in ultraviolet light curing coatings.

9. The use according to claim 8, characterized in that: The anti-fouling agent is added in an amount of 0.2-3.0 wt % in the UV-curable coating.

10. The use according to claim 8, characterized in that: The ultraviolet curing coating is used for the surface layer of a transparent plastic substrate, and the transparent plastic substrate comprises at least one of PET, PMMA, PC and PVC.

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