Method for preparing antifouling coating through electrophoretic deposition

Abstract

The invention discloses a method for preparing an antifouling coating through electrophoretic deposition, and belongs to the technical field of multifunctional coatings. According to the method, the polyurethane-epoxy resin coating is firstly subjected to electrophoretic deposition on the base material, the ultrathin polyurethane-epoxy resin coating can be obtained through electrophoretic deposition, and the polyurethane-epoxy resin coating is arranged on the bottom layer of the base material, so that the adhesive force between the coating and the base material can be increased; then an organic silicon solution is sprayed to form an organic silicon coating, a polyurethane network and an organic silicon polymer network are fused and anchored, two layers of interacted three-dimensional networks are obtained after curing and crosslinking, and the flexibility of the antifouling coating is improved through the polyurethane-epoxy resin coating; and the organic silicon coating on the upper layer can form a dynamic liquid-like interface layer by utilizing a silicon chain to prevent adhesion of various liquids, so that the antifouling coating which is high in adhesion capacity and good in flexibility and can repel adhesion of various liquids and prevent adhesion of bacteria is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of multifunctional coatings, and in particular relates to a method for preparing an antifouling coating by electrophoretic deposition. Background Art

[0002] Antifouling coatings play a vital role in inhibiting the adhesion of various types of oil, bacteria, blood and other materials to the surface. However, the current antifouling coatings have poor mechanical properties and adhesion, as well as easy to cause microbial corrosion, which has adverse effects on the environment, economy and human health. Therefore, the development of non-toxic and efficient antifouling coatings is related to major national needs such as energy, medical care, and the environment. At present, silicone coating materials have gradually replaced toxic fluorine-containing antifouling coatings due to their advantages such as low surface energy and non-toxicity. The silicone coatings made by filling inorganic fillers (such as SiO2) in organic coatings lack compatibility and are prone to rapid failure of the antifouling effect; while silicone oil is grafted into the polymer chain segment and migrates to the coating surface during the curing process to form a weak liquid-like interface layer. This interface layer forms a physical dynamic surface that repels various liquids and has a good antifouling effect. However, there are also problems such as poor mechanical properties of the coating, poor adhesion to the substrate, and limited application scenarios.

[0003] Chinese patent CN202310800739.X discloses a method for preparing a high-hardness organic silicon coating. The invention uses silane coupling agents, silicone oil-based liquid low-surface energy compounds, and multifunctional acrylates to prepare a polymer network with flexible silicon chains, and obtains an organic silicon coating with high hardness and good antifouling effect. However, the curing temperature of the coating is relatively high (the curing temperature is 80-150°C), and the coating has a high hardness and cannot be flexibly folded, which limits the application scenarios.

[0004] Therefore, there is an urgent need for an antifouling coating with low curing temperature, strong adhesion, good flexibility and good antifouling effect. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a method for preparing an antifouling coating by electrophoretic deposition.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing an antifouling coating by electrophoretic deposition, comprising the following steps:

[0008] (1) mixing diisocyanate, polyester polyol, crosslinking agent, catalyst and solvent for a first reaction, then adding epoxy resin solution for a second reaction, then adding lactic acid for neutralization, and then adding water for dispersion to obtain cationic resin electrophoretic paint;

[0009] (2) mixing a silane coupling agent, an organic solvent and water and performing constant temperature hydrolysis to obtain a hydrolyzate; adding a silicone oil-based liquid low surface energy compound and a multifunctional acrylate to the obtained hydrolyzate, mixing well, and obtaining an organosilicon solution;

[0010] (3) placing the conductive substrate in the cationic resin electrophoretic paint obtained in step (1) for electrophoresis to form a polyurethane-epoxy resin coating, and then spraying the organic silicon solution obtained in step (2) on the conductive substrate after electrophoresis, and curing to obtain an antifouling coating;

[0011] There is no order of precedence for steps (1) and (2).

[0012] Preferably, in step (1), the molar ratio of the diisocyanate, polyester polyol and cross-linking agent is (10-20):(3-5):(5-10); and the molar ratio of the hydroxyl group of the epoxy resin in the epoxy resin solution to the remaining NCO group in the diisocyanate is 1:1.

[0013] Preferably, in step (1), the diisocyanate is at least one of L-lysine diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and tetramethylxylene diisocyanate; the polyester polyol is polytetrahydrofuran with M=2000; the cross-linking agent is N-methyldiethanolamine; and the catalyst is at least one of dibutyltin dilaurate, stannous octoate, and azobisisobutyronitrile.

[0014] Preferably, in step (1), the epoxy resin in the epoxy resin solution is E51 epoxy resin, and the molar mass is 400 to 1000.

[0015] Preferably, in step (1), the temperature of the first reaction and the second reaction are both 60-100° C., and the time of the first reaction and the second reaction are both 2-4 hours; and / or,

[0016] The solid content of the cationic resin electrophoretic paint is 0-50% and is not 0.

[0017] Preferably, in step (2), the chemical composition of the silane coupling agent is Y(CH2) n SiX3, wherein n=1-3, X is a hydrolyzable group, and Y is an organic functional group; the silicone oil-based liquid low surface energy compound is one of amino-terminated silicone oil, aminophenyl silicone oil, and aminohydroxy silicone oil; the multifunctional acrylate is one of pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol pentaacrylate.

[0018] Preferably, in step (2), the mass ratio of the silane coupling agent, the organic solvent and water is 10:10:(1-2); and / or,

[0019] The mass ratio of the hydrolyzate, the multifunctional acrylate and the silicone oil-based liquid low surface energy compound is (1-2): (3-5): (0.1-0.5).

[0020] Preferably, in step (3), the electrophoresis voltage is 10 to 30 V, and the electrophoresis time is 10 to 60 s.

[0021] Preferably, in step (3), the curing temperature is 80 to 120° C., and the curing time is 1 to 5 hours.

[0022] The present invention also provides an antifouling coating prepared by the method for preparing an antifouling coating based on electrophoretic deposition described in the above technical solution.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] The invention first electrophoretically deposits a polyurethane-epoxy resin coating on a substrate, and the electrophoretic deposition can obtain an ultra-thin polyurethane-epoxy resin coating. The polyurethane-epoxy resin coating is arranged on the bottom layer of the substrate to increase the adhesion between the coating and the substrate; then, an organic silicon solution is sprayed to form an organic silicon coating, and a polyurethane network and an organic silicon polymer network are fused and anchored, and two layers of interacting three-dimensional networks are obtained after curing and cross-linking. The polyurethane-epoxy resin coating improves the flexibility of the antifouling coating, and the upper organic silicon coating can form a dynamic liquid-like interface layer by using silicon chains to prevent the adhesion of various liquids, thereby obtaining an antifouling coating with strong adhesion ability, good flexibility, and the ability to repel the adhesion of various liquids and prevent the adhesion of bacteria.

[0025] The present invention utilizes electrophoretic deposition to prepare an antifouling coating. On the one hand, the thickness of the polyurethane-epoxy resin coating can be controlled by selecting the process parameters of the electrophoretic deposition. On the other hand, the electrophoretic deposition is applicable to complex devices of various materials and structures, and has a wide range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0027] Figure 1 This is a physical picture of the electrophoretic deposition in step (3) of Examples 1 to 6;

[0028] Figure 2 It is a line graph of the water contact angle and sliding angle of the antifouling coating prepared in Examples 1 to 4;

[0029] Figure 3 It is a line graph of the peanut oil contact angle and sliding angle of the antifouling coating prepared in Examples 1 to 4;

[0030] Figure 4 This is a real picture of the oil droplet just coming into contact with the antifouling coating prepared in Example 1;

[0031] Figure 5 This is a diagram showing the adhesion of oil droplets on the surface of the antifouling coating prepared in Example 1 after 2 minutes;

[0032] Figure 6 The anti-bacterial adhesion performance of the anti-fouling coatings prepared in Examples 1 to 4 of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in 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.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] The embodiment of the present invention provides a method for preparing an antifouling coating by electrophoretic deposition, comprising the following steps:

[0036] (1) mixing diisocyanate, polyester polyol, crosslinking agent, catalyst and solvent for a first reaction, then adding epoxy resin solution for a second reaction, then adding lactic acid for neutralization, and then adding water for dispersion to obtain cationic resin electrophoretic paint;

[0037] (2) mixing a silane coupling agent, an organic solvent and water and performing constant temperature hydrolysis to obtain a hydrolyzate; adding a silicone oil-based liquid low surface energy compound and a multifunctional acrylate to the obtained hydrolyzate, mixing well, and obtaining an organosilicon solution;

[0038] (3) placing the conductive substrate in the cationic resin electrophoretic paint obtained in step (1) for electrophoresis to form a polyurethane-epoxy resin coating, and then spraying the organic silicon solution obtained in step (2) on the conductive substrate after electrophoresis, and curing to obtain an antifouling coating;

[0039] There is no order of precedence for steps (1) and (2).

[0040] In a preferred embodiment, in step (1), the molar ratio of the diisocyanate, polyester polyol and cross-linking agent is (10-20):(3-5):(5-10), and more preferably (15-20):(3-5):(6-10).

[0041] In a preferred embodiment, in step (1), the diisocyanate is at least one of L-lysine diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and tetramethylxylylene diisocyanate. The present invention has been verified by experiments that the antifouling coatings prepared by the above diisocyanates have equivalent technical effects. In the embodiment, isophorone diisocyanate is selected as an example, which is typical but not restrictive.

[0042] In a preferred embodiment, in step (1), the polyester polyol is polytetrahydrofuran with M=2000; the polytetrahydrofuran needs to be dehydrated before use.

[0043] In a preferred embodiment, in step (1), the cross-linking agent is N-methyldiethanolamine.

[0044] In a preferred embodiment, in step (1), the catalyst is at least one of dibutyltin dilaurate, stannous octoate, and azobisisobutyronitrile, and more preferably dibutyltin dilaurate; the amount ratio of the catalyst to diisocyanate is 4.45 g: 20 μL.

[0045] In a preferred embodiment, in step (1), the solvent is at least one of N-methylpyrrolidone, propylene glycol methyl ether acetate, and acetone, and is more preferably N-methylpyrrolidone; and the mass ratio of the solvent to the diisocyanate is 4.45:(10-20).

[0046] In a preferred embodiment, in step (1), the epoxy resin in the epoxy resin solution is E51 epoxy resin with a molar mass of 400 to 1000; the solvent in the epoxy resin solution includes N-methylpyrrolidone; and the mass ratio of the solvent to the epoxy resin in the epoxy resin solution is 5:2. The E51 epoxy resin used in the present invention has the advantages of strong adhesion and high toughness.

[0047] In a preferred embodiment, in step (1), the molar ratio of the hydroxyl group of the epoxy resin to the residual NCO group of the diisocyanate in the epoxy resin solution is 1: 1. The present invention combines the advantages of polyurethane and epoxy resin by preparing the polyurethane-epoxy resin coating on the bottom layer, and then combines it with electrodeposition to obtain an ultra-thin polyurethane-epoxy resin coating with strong adhesion and high softness, thereby improving the flexibility of the antifouling coating and obtaining an antifouling coating that can be flexibly folded.

[0048] In a preferred embodiment, in step (1), the temperature of the first reaction and the second reaction are both 60-100° C., and the time of the first reaction and the second reaction are both 2-4 hours.

[0049] In a preferred embodiment, in step (1), the mass ratio of the lactic acid to the epoxy resin in the epoxy resin solution is 2:0.7.

[0050] In a preferred embodiment, in step (1), the neutralization time is 1 hour.

[0051] In a preferred embodiment, in step (1), the solid content of the cationic resin electrophoretic paint is 0-50%, and is not 0; more preferably, it is 20-40%. In an embodiment of the present invention, the less the solid content of the cationic resin electrophoretic paint, the thinner the electrophoretic paint, and the thinner the electrophoretic coating obtained.

[0052] In a preferred embodiment, in step (2), the chemical composition of the silane coupling agent is Y(CH2) n SiX3, wherein n=1-3, X is a hydrolyzable group, and Y is an organic functional group; the silane coupling agent is one of γ-methacryloxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, vinylmethyldimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, N-(β-aminoethyl-γ-aminopropyl)methyltrimethoxysilane, and vinyltrimethoxysilane, and is further preferably one of 3-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, and vinyltrimethoxysilane.

[0053] In a preferred embodiment, in step (2), the mass ratio of the silane coupling agent, the organic solvent and water is 10:10:(1-2); and the organic solvent includes ethanol.

[0054] In a preferred embodiment, in step (2), the temperature of the isothermal hydrolysis is 40 to 80° C., more preferably 40 to 60° C.; the time of the isothermal hydrolysis is 2 to 8 hours, more preferably 2 to 4 hours.

[0055] In a preferred embodiment, in step (2), the silicone oil-based liquid low surface energy compound is one of amino-terminated silicone oil, aminophenyl silicone oil, and aminohydroxy silicone oil, and is further preferably one of amino-terminated silicone oil and aminohydroxy silicone oil.

[0056] In a preferred embodiment, in step (2), the multifunctional acrylate is one of pentaerythritol triacrylate, pentaerythritol tetraacrylate and dipentaerythritol pentaacrylate, and more preferably one of pentaerythritol triacrylate and dipentaerythritol pentaacrylate.

[0057] In a preferred embodiment, in step (2), the mass ratio of the hydrolyzate, the multifunctional acrylate and the silicone oil-based liquid low surface energy compound is (1-2):(3-5):(0.1-0.5), and more preferably (1-2):(3-5):(0.1-0.3).

[0058] In a preferred embodiment, in step (3), the conductive substrate includes one of an iron sheet, a titanium sheet, and a stainless steel sheet.

[0059] In a preferred embodiment, in step (3), the electrophoresis voltage is 10 to 30 V, more preferably 15 to 25 V; the electrophoresis time is 10 to 60 s, more preferably 20 to 40 s. The present invention can adjust the thickness of the polyurethane-epoxy resin coating by selecting the process parameters of electrophoretic deposition. The higher the electrophoresis voltage, the thicker the obtained coating, and the longer the electrophoresis time, the thicker the obtained coating; when the cations in the cationic resin electrophoretic paint are consumed, the thickness of the coating no longer changes.

[0060] In a preferred embodiment, in step (3), the thickness of the polyurethane-epoxy resin coating is 0.05-0.2 mm.

[0061] In a preferred embodiment, in step (3), the curing temperature is 80 to 120° C., more preferably 80 to 100° C.; the curing time is 1 to 5 hours, more preferably 1 to 4 hours.

[0062] The present invention also provides an antifouling coating prepared by the method for preparing an antifouling coating by electrophoretic deposition described in the above technical solution.

[0063] The antifouling coating provided by the invention has strong adhesion ability and good flexibility, and can also repel adhesion of various liquids and prevent adhesion of bacteria.

[0064] Unless otherwise specified, the raw materials in the examples of the present invention were purchased from commercial sources.

[0065] Example 1

[0066] A method for preparing an antifouling coating by electrophoretic deposition:

[0067] (1) Dehydrate polytetrahydrofuran (M=2000) for later use, dissolve 4.45 g (0.02 mol) of isophorone diisocyanate (IPDI), 10 g (0.005 mol) of polytetrahydrofuran (PTMG), 0.9 g (0.008 mol) of N-methyldiethanolamine (MDEA), and 20 μL of dibutyltin dilaurate in 20 g of N-methylpyrrolidone, mix in a three-necked flask, and heat to 80° C. for reaction. After reacting for 3 h, add E51 epoxy resin solution obtained by dissolving 2 g of E51 epoxy resin (the molar ratio of the hydroxyl group in the E51 epoxy resin to the remaining NCO group in the diisocyanate is 1:1) in 5 g of N-methylpyrrolidone (NMP), react for 2 h, then add 0.7 g of lactic acid for neutralization for 1 h, and finally add 112 g of water and stir evenly to obtain a cationic resin electrophoretic paint with a solid content of 20%;

[0068] (2) 5 g of 3-aminopropyltriethoxysilane (KH-550) and 5 g of ethanol were mixed evenly, and then 0.5 g of water was added and mixed evenly, and hydrolysis reaction was carried out at a constant temperature of 60° C. for 4 h to obtain a hydrolyzate; 1 g of the above hydrolyzate, 3 g of pentaerythritol triacrylate, 1 g of ethanol, 3 g of propylene glycol methyl ether acetate and 0.1 g of amino-terminated silicone oil were weighed and mixed, and stirred for 24 h to obtain an organosilicon solution;

[0069] (3) placing the iron sheet in the cationic resin electrophoretic paint obtained in step (1), setting the electrophoretic voltage to 15 V and the electrophoretic time to 20 s, to form a 0.05 mm thick polyurethane-epoxy resin coating, and then spraying the organosilicon solution obtained in step (2) on the iron sheet after electrophoresis, and then placing it in a 100° C. oven for curing for 4 h to cross-link it into a film, thereby obtaining an antifouling coating.

[0070] Example 2

[0071] A method for preparing an antifouling coating by electrophoretic deposition:

[0072] (1) Dehydrate polytetrahydrofuran (M=2000) for later use, dissolve 4.45 g (0.02 mol) of isophorone diisocyanate (IPDI), 10 g (0.005 mol) of polytetrahydrofuran (PTMG), 0.9 g (0.008 mol) of N-methyldiethanolamine (MDEA), and 20 μL of dibutyltin dilaurate in 20 g of N-methylpyrrolidone solvent, mix in a three-necked flask, and heat to 80° C. for reaction. After reacting for 3 h, add E51 epoxy resin solution obtained by dissolving 2 g of E51 epoxy resin (the molar ratio of the hydroxyl group in the E51 epoxy resin to the remaining NCO group in the diisocyanate is 1:1) in 5 g of N-methylpyrrolidone (NMP), react for 2 h, then add 0.7 g of lactic acid for neutralization for 1 h, and finally add 42 g of water and stir evenly to obtain a cationic resin electrophoretic paint with a solid content of 40%;

[0073] (2) 5 g of 3-aminopropyltriethoxysilane (KH-550) and 5 g of ethanol were mixed evenly, and then 0.5 g of water was added and mixed evenly, and the mixture was hydrolyzed at a constant temperature of 60° C. for 4 h to obtain a hydrolyzate; 1 g of the above hydrolyzate, 3 g of pentaerythritol triacrylate, 1 g of ethanol, 3 g of propylene glycol methyl ether acetate, and 0.1 g of amino-terminated silicone oil were weighed and mixed, and stirred for 24 h to obtain an organosilicon solution;

[0074] (3) placing the iron sheet in the cationic resin electrophoretic paint obtained in step (1), setting the electrophoretic voltage to 15 V and the electrophoretic time to 20 s, to form a 0.12 mm polyurethane-epoxy resin coating, and then spraying the organosilicon solution obtained in step (2) on the iron sheet after electrophoresis, and then placing it in a 100° C. oven for curing for 4 h to cross-link it into a film, thereby obtaining an antifouling coating.

[0075] Example 3

[0076] A method for preparing an antifouling coating by electrophoretic deposition:

[0077] (1) Dehydrate polytetrahydrofuran (M=2000) for later use, dissolve 4.45 g (0.02 mol) of isophorone diisocyanate (IPDI), 10 g (0.005 mol) of polytetrahydrofuran (PTMG), 0.9 g (0.008 mol) of N-methyldiethanolamine (MDEA), and 20 μL of dibutyltin dilaurate in 20 g of N-methylpyrrolidone solvent, mix in a three-necked flask, and heat to 80° C. for reaction. After reacting for 3 h, add an E51 epoxy resin solution obtained by dissolving 2 g of E51 epoxy resin (the molar ratio of the hydroxyl group in the E51 epoxy resin to the remaining NCO group in the diisocyanate is 1:1) in 5 g of N-methylpyrrolidone (NMP), react for 2 h, then add 0.7 g of lactic acid for neutralization for 1 h, and finally add 112 g of water and stir evenly to obtain a cationic resin electrophoretic paint with a solid content of 20%;

[0078] (2) 5 g of 3-aminopropyltriethoxysilane (KH-550) and 5 g of ethanol were mixed evenly, and then 0.5 g of water was added and mixed evenly, and the mixture was hydrolyzed at a constant temperature of 60° C. for 4 h to obtain a hydrolyzate; 1 g of the above hydrolyzate, 3 g of pentaerythritol triacrylate, 1 g of ethanol, 3 g of propylene glycol methyl ether acetate, and 0.2 g of amino-terminated silicone oil were weighed and mixed, and stirred for 24 h to obtain an organosilicon solution;

[0079] (3) placing the iron sheet in the cationic resin electrophoretic paint obtained in step (1), setting the electrophoretic voltage to 15 V and the electrophoretic time to 20 s, to form a 0.08 mm thick polyurethane-epoxy resin coating, and then spraying the organosilicon solution obtained in step (2) on the iron sheet after electrophoresis, and then placing it in a 100° C. oven for curing for 4 h to cross-link it into a film, thereby obtaining an antifouling coating.

[0080] Example 4

[0081] A method for preparing an antifouling coating by electrophoretic deposition:

[0082] (1) Dehydrate polytetrahydrofuran (M=2000) for later use, dissolve 4.45 g (0.02 mol) of isophorone diisocyanate (IPDI), 10 g (0.005 mol) of polytetrahydrofuran (PTMG), 0.9 g (0.008 mol) of N-methyldiethanolamine (MDEA), and 20 μL of dibutyltin dilaurate in 20 g of N-methylpyrrolidone solvent, mix in a three-necked flask, and heat to 80° C. for reaction. After reacting for 3 h, add an E51 epoxy resin solution obtained by dissolving 2 g of E51 epoxy resin (the molar ratio of the hydroxyl group in the E51 epoxy resin to the remaining NCO group in the diisocyanate is 1:1) in 5 g of N-methylpyrrolidone (NMP), react for 2 h, then add 0.7 g of lactic acid for neutralization for 1 h, and finally add 112 g of water and stir evenly to obtain a cationic resin electrophoretic paint with a solid content of 20%;

[0083] (2) 5 g of 3-aminopropyltriethoxysilane (KH-550) and 5 g of ethanol were mixed evenly, and then 0.5 g of water was added and mixed evenly, and the mixture was hydrolyzed at a constant temperature of 60° C. for 4 h to obtain a hydrolyzate; 1 g of the above hydrolyzate, 3 g of pentaerythritol triacrylate, 1 g of ethanol, 3 g of propylene glycol methyl ether acetate, and 0.3 g of amino-terminated silicone oil were weighed and mixed, and stirred for 24 h to obtain an organosilicon solution;

[0084] (3) placing the iron sheet in the cationic resin electrophoretic paint obtained in step (1), setting the electrophoretic voltage to 30 V and the electrophoretic time to 30 s, to form a 0.1 mm polyurethane-epoxy resin coating, and then spraying the organosilicon solution obtained in step (2) on the iron sheet after electrophoresis, and then placing it in a 100° C. oven for curing for 4 hours to cross-link it into a film, thereby obtaining an antifouling coating.

[0085] Figure 1 This is a physical picture of the electrophoretic deposition in step (3) of Examples 1 to 6. Figure 1 It can be seen that the present invention prepares a polyurethane-epoxy resin coating on the surface of the substrate by placing the conductive substrate in a cationic resin electrophoretic paint for electrophoretic deposition.

[0086] The contact angle (CA) and sliding angle (SA) of the antifouling coatings prepared in the embodiments and comparative examples with water were measured using a CA meter (JC2000A, Dongguan Shengding Precision Instruments, Dongguan, China): at 25°C, the droplet volumes used in the CA and SA measurements were 5 μL and 20 μL, respectively, and each average value was calculated from 3 different areas of the sample.

[0087] Table 1 Performance of antifouling coatings prepared in Examples 1 to 4

[0088] Example 1 Example 2 Example 3 Example 4 Contact angle / ° 105 108 112 110 Sliding angle / ° 35 52 21 15

[0089] Figure 2It is a line graph of the water contact angle and sliding angle of the antifouling coating prepared in Examples 1 to 4.

[0090] Depend on Figure 2 As can be seen from Table 1, the contact angles of the antifouling coatings prepared in Examples 1 to 4 with water are 105 to 110°, and the sliding angles are 15 to 52°, indicating that the antifouling coatings prepared in the present invention can effectively prevent water adhesion.

[0091] The contact angle (CA) and sliding angle (SA) of the antifouling coatings prepared in the examples and comparative examples with peanut oil were measured using a CA measuring instrument (JC2000A, Dongguan Shengding Precision Instruments, Dongguan, China). At 25°C, the droplet volumes used in the CA and SA measurements were 5 μL and 20 μL, respectively, and each average value was calculated from 3 different areas of the sample. The test results are shown in Table 2.

[0092] Table 2 Oil contact angle and sliding angle of antifouling coatings prepared in Examples 1 to 4

[0093] Example 1 Example 2 Example 3 Example 4 Contact angle / ° 12 10 13 12 Sliding angle / ° 15 23 12 10

[0094] Figure 3 It is a line graph of the peanut oil contact angle and sliding angle of the antifouling coating prepared in Examples 1 to 4.

[0095] Depend on Figure 3 As can be seen from Table 2, the contact angles of the antifouling coatings prepared in Examples 1 to 4 with peanut oil are 10 to 13°, and the sliding angles are 10 to 23°, indicating that the antifouling coatings prepared in the present invention can effectively prevent the adhesion of peanut oil.

[0096] Figure 4 This is a real picture of the oil droplet just coming into contact with the antifouling coating prepared in Example 1. Figure 5 The figure is a diagram showing the adhesion of oil droplets on the surface of the antifouling coating prepared in Example 1 after 2 minutes. Figure 4 and Figure 5 It can be seen that the antifouling coating prepared in Example 1 of the present invention can effectively prevent the adhesion of oil.

[0097] 0.5 mL of E. coli solution (concentration of the solution: 107 / mL) was added to the antifouling coating (1 cm×1 cm) prepared in Examples 1-4 and a blank glass substrate, and then inoculated and cultured for 12 h in a test tube containing 4.5 mL of PBS solution. After the culture was completed, 500 μL of the cultured liquid was diluted and shaken in 4.5 mL of PBS solution, and then 100 μL of the diluted solution was taken in an agar medium and evenly spread with a coating rod. Finally, the culture dish was placed in a constant temperature incubator at 37°C for 14 h, the culture dish phenomenon was observed, and photos were taken.

[0098] Figure 6The anti-bacterial adhesion performance of the anti-fouling coatings prepared in Examples 1 to 4 of the present invention. Figure 6 From left to right, they are blank group, Example 1, Example 2, Example 3, and Example 4. Figure 6 It can be seen that the culture dish of the blank group is full of bacteria, while the antifouling coating prepared by the present invention can effectively prevent the adhesion of Escherichia coli.

[0099] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing an antifouling coating by electrophoretic deposition, characterized in that: The following steps are involved: (1) mixing diisocyanate, polyester polyol, crosslinking agent, catalyst and solvent for a first reaction, then adding epoxy resin solution for a second reaction, then adding lactic acid for neutralization, and then adding water for dispersion to obtain cationic resin electrophoretic paint; (2) mixing a silane coupling agent, an organic solvent and water and performing constant temperature hydrolysis to obtain a hydrolyzate; adding a silicone oil-based liquid low surface energy compound and a multifunctional acrylate to the obtained hydrolyzate, mixing well, and obtaining an organosilicon solution; (3) placing the conductive substrate in the cationic resin electrophoretic paint obtained in step (1) for electrophoresis to form a polyurethane-epoxy resin coating, and then spraying the organic silicon solution obtained in step (2) on the conductive substrate after electrophoresis, and curing to obtain an antifouling coating; There is no order of precedence for steps (1) and (2).

2. The method for preparing an antifouling coating by electrophoretic deposition according to claim 1, characterized in that: In step (1), the molar ratio of the diisocyanate, polyester polyol and cross-linking agent is (10-20): (3-5): (5-10); and / or, The molar ratio of the hydroxyl group of the epoxy resin to the remaining NCO group of the diisocyanate in the epoxy resin solution is 1:

1.

3. The method for preparing an antifouling coating by electrophoretic deposition according to claim 1, characterized in that: In step (1), the diisocyanate is at least one of L-lysine diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and tetramethylxylylene diisocyanate; and / or, The polyester polyol is polytetrahydrofuran with M=2000; and / or, The cross-linking agent is N-methyldiethanolamine; and / or, The catalyst is at least one of dibutyltin dilaurate, stannous octoate and azobisisobutyronitrile.

4. The method for preparing an antifouling coating by electrophoretic deposition according to claim 1, characterized in that: In step (1), the epoxy resin in the epoxy resin solution is E51 epoxy resin, and the molar mass is 400-1000.

5. The method for preparing an antifouling coating by electrophoretic deposition according to claim 1, characterized in that: In step (1), the temperature of the first reaction and the second reaction are both 60-100° C., and the time of the first reaction and the second reaction are both 2-4 hours; and / or, The solid content of the cationic resin electrophoretic paint is 0-50% and is not 0.

6. The method for preparing an antifouling coating by electrophoretic deposition according to claim 1, characterized in that: In step (2), the chemical composition of the silane coupling agent is Y(CH2) n SiX3, wherein n=1-3, X is a hydrolyzable group, and Y is an organic functional group; the silicone oil-based liquid low surface energy compound is one of amino-terminated silicone oil, aminophenyl silicone oil, and aminohydroxy silicone oil; the multifunctional acrylate is one of pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol pentaacrylate.

7. The method for preparing an antifouling coating by electrophoretic deposition according to claim 1, characterized in that: In step (2), the mass ratio of the silane coupling agent, the organic solvent and water is 10:10:(1-2); and / or, The mass ratio of the hydrolyzate, the multifunctional acrylate and the silicone oil-based liquid low surface energy compound is (1-2): (3-5): (0.1-0.5).

8. The method for preparing an antifouling coating by electrophoretic deposition according to claim 1, characterized in that: In step (3), the electrophoresis voltage is 10 to 30 V, and the electrophoresis time is 10 to 60 s.

9. The method for preparing an antifouling coating by electrophoretic deposition according to claim 1, characterized in that: In step (3), the curing temperature is 80 to 120° C., and the curing time is 1 to 5 hours.

10. The antifouling coating prepared by the method for preparing an antifouling coating by electrophoretic deposition according to any one of claims 1 to 9.

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