A waterborne UV insulating coating, its preparation method and application

Abstract

The application provides an aqueous UV insulating coating, a preparation method and application thereof. The application controls the preparation method to obtain a star-shaped epoxy soybean oil prepolymer, introduces an acrylate, a siloxane chain segment and a mussel myoalbumin into the prepolymer with the star-shaped structure to obtain an insulating resin matrix, improves the electrical property, heat resistance, mechanical strength and adhesion to the substrate of the coating resin after curing of the coating, and further introduces a phosphoric acid group to react with the mussel myoalbumin to generate a mussel phosphate, so that the adhesion to the substrate of the coating can be significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of insulating materials, in particular to a water-based UV insulating paint, a preparation method and application thereof. BACKGROUND

[0002] Due to the vigorous development of new energy battery field, the use of batteries is becoming more and more widespread. At present, the insulation of batteries is mainly protected by blue film and paint. The insulating blue film has low breakdown voltage resistance, low shear strength, and defects such as bubbles in the rolled film, and major battery manufacturers urgently need a replacement insulating blue film solution. Ultraviolet (UV) curing paint is a new type of paint that is efficient, energy-saving and environmentally friendly. It has high mechanical properties and good insulation voltage resistance. Compared with powder paint, it does not require high temperature and can be packaged in advance to form a film in one step, and the coating preparation efficiency is extremely high, so it is becoming the preferred solution for high-end battery insulation.

[0003] Traditional UV insulating paint has excellent comprehensive performance and good insulation performance, but it needs to be diluted with active diluent, has a strong odor, is easy to evaporate, and has a great impact on the environment and construction personnel, and the coating shrinks greatly after curing. Water-based UV insulating paint uses water as a diluent and is non-toxic and non-irritating, which is the development direction of current ultraviolet curing paint.

[0004] In the field of insulation, epoxy resin has high strength, strong adhesion and good electrical performance, and is an excellent insulating material, but it has poor weather resistance and is prone to aging; acrylic resin has good weather resistance but general electrical performance; polymethylsiloxane has good resistance to severe high and low temperature changes and good insulation, and can still maintain good mechanical properties under harsh conditions. Therefore, combining the three and giving water-based UV curing ability will be a way to prepare water-based UV insulating paint with excellent comprehensive performance. However, due to the high crosslinking density and hardness of water-based UV paint, the adhesion on metal substrates is poor, and it is usually used on plastic paint and wood paint (such as patent CN108384317A - A kind of high temperature resistant type concave water-based ink and its preparation method discloses a water-based ink with polyurethane-acrylic-epoxy soybean oil composite emulsion as the base). It is rarely used in the field of insulating paint.

[0005] Therefore, it is necessary to provide a water-based UV insulating paint with good electrical performance, heat resistance, mechanical strength and adhesion performance. SUMMARY

[0006] The present application aims at overcoming the defects that the adhesion of the existing waterborne UV insulating coating to the substrate still needs to be improved, and providing a waterborne UV insulating coating with good electrical performance, heat resistance and adhesion to the substrate.

[0007] Another object of the present application is to provide a preparation method of the waterborne UV insulating coating.

[0008] Another object of the present application is to provide an application of the waterborne UV insulating coating in the field of corrosion prevention and / or insulation.

[0009] To achieve the above objects, the present application adopts the following technical solutions.

[0010] A waterborne UV insulating coating comprises the following components by weight:

[0011]

[0012] The epoxy-silicone-acrylic polyurethane emulsion is prepared by the following method comprising the following steps:

[0013] S1. The epoxy soybean oil, diisocyanate, catalyst and hydrophilic solvent are mixed uniformly, and then reacted under an inert atmosphere at 50-70 DEG C for 4-8 hours to obtain an isocyanate-terminated star-shaped prepolymer;

[0014] S2. The active H-terminated polymethylsiloxane, mussel adhesive protein and hydrophilic chain extender are added to the reaction system obtained in step S1, and then reacted under an inert atmosphere at 50-70 DEG C for 4-8 hours to obtain a hydrophilic prepolymer terminated by isocyanate;

[0015] S3. The hydroxyl-containing acrylic ester monomer is mixed with the isocyanate-terminated hydrophilic prepolymer obtained in step S2 under an inert atmosphere, and then reacted completely at 50-80 DEG C to obtain an acrylic ester-terminated polyurethane prepolymer;

[0016] S4. The phosphate monomer is added to the acrylic ester-terminated polyurethane prepolymer obtained in step S3 under an inert atmosphere, and then reacted under acid catalysis, and finally emulsified with water to obtain the modified epoxy-silicone-acrylic polyurethane emulsion.

[0017] The application selects a specific modified epoxy siloxane acrylic polyurethane emulsion as a curing matrix. In the process of synthesizing the modified epoxy siloxane acrylic polyurethane, first, a star-shaped prepolymer with a bio-based core is prepared by reacting an epoxy soybean oil containing multiple epoxy groups and hydroxyl groups with isocyanate. Compared with the current hyperbranched substance, the star-shaped prepolymer is more environmentally friendly, cheaper, and easier to synthesize, and also has the performance of high solid and low viscosity and more reactive sites. A polyalkylsiloxane containing active H is added to the star-shaped prepolymer capped with isocyanate to introduce a siloxane segment with good high and low temperature resistance and insulation performance. Then, the star-shaped prepolymer is hydrophilically modified. Finally, an acrylic ester monomer containing active H is used to cap the star-shaped prepolymer to introduce an acrylic resin segment and endow the resin with UV curing ability. The above synthesis scheme organically combines epoxy resin, siloxane resin and acrylic resin, and by adjusting the ratio of the three and the soft and hard segments, a water-based UV insulating coating with excellent electrical insulation performance, heat resistance, chemical resistance and mechanical performance can be obtained.

[0018] However, the simple mussel group is prone to oxidation and self-polymerization, and it is difficult to play its role well. The application also creatively introduces a phosphoric acid group. The phosphoric acid group reacts with mussel mucin to obtain mussel phosphate. During the curing and drying process of the coating, the phosphoric acid group and the catechol group are released. The strong adhesion of the catechol group and the phosphoric acid group to the substrate can make the coating tightly adhere to the substrate, thereby solving the problem that the high-hardness water-based UV coating is difficult to adhere to the metal substrate and is prone to cracking.

[0019] Preferably, the epoxy soybean oil is one or several of the structures (RC2H2OR'COO)3C3H5, wherein R is selected from at least one of C6H 12 , C7H 14 ; R' is selected from at least one of C9H 19 , C8OH 15 . Specifically, at least one of the products such as Macklin E808876, Ron R016786, etc. can be selected.

[0020] Preferably, the hydrophilic solvent includes but is not limited to at least one of dipropylene glycol dimethyl ether, dipropylene glycol dibutyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate, N,N-dimethylformamide (DMF). The amount of the hydrophilic solvent in step S1 is 0.5-1.0 times the weight of the epoxy soybean oil.

[0021] Preferably, the diisocyanate includes at least one of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI). The amount of the diisocyanate is (0.8-1.6):1 by weight ratio of diisocyanate to epoxy soybean oil.

[0022] Conventional catalysts in the art can be used in the present application to prepare the modified epoxysilicone acrylic polyurethane emulsion, including but not limited to at least one of dibutyltin dilaurate or n-butyl titanate. The amount of the catalyst is 100-300 ppm based on the total weight of diisocyanate and epoxidized soybean oil.

[0023] Preferably, the active H-terminated polymethylsiloxane can be at least one of dihydroxyl-terminated polymethylsiloxane, diamino-terminated polymethylsiloxane.

[0024] The dihydroxyl-terminated polymethylsiloxane has a structure of HO-Si(CH3)2O[Si(CH3)2O] n Si(CH3)2-OH, and can be specifically at least one of Sigma 481939, McIlvaine P856624, Shin-Etsu P-0444322.

[0025] The diamino-terminated polymethylsiloxane has a structure of NH2-Si(CH3)2O[Si(CH3)2O] n Si(CH3)2-NH2, and can be specifically at least one of products such as McIlvaine 829524.

[0026] Preferably, the mussel myoglobin is at least one of mussel byssin protein extract with catechol structure or modified product of mussel byssin protein extract with catechol structure, such as mussel myoglobin products of companies such as Guangdong Wengjiang Chemical Reagent Co., Ltd., Qiyuan (Guangdong) Pharmaceutical Chemical Co., Ltd., and Guangdong Yunxing Biotechnology Co., Ltd.

[0027] Conventional hydrophilic chain extenders can be used in the present application, including but not limited to at least one of 1,2-dihydroxy-3-propanesulfonic acid sodium, 1,4-butanediol disulfonic acid sodium, ethylenediamine sulfonic acid sodium, polyethylene glycol (PEG), and trimethylolpropane polyethylene glycol monomethyl ether.

[0028] Preferably, the weight ratio of the active H-terminated polymethylsiloxane, mussel myoglobin, hydrophilic chain extender, and epoxidized soybean oil is (0.3-2.0):(0.05-0.3):(0.1-0.5):1.

[0029] Preferably, the hydroxyl-containing acrylate monomer is at least one of hydroxyethyl acrylate (HEA), hydroxyethyl methacrylate (HEMA), acrylic acid-β-hydroxypropyl ester (HPA), methacrylic acid-β-hydroxypropyl ester (HPMA), and a hydroxyl-containing acrylic resin. The weight ratio of the hydroxyl-containing acrylate monomer and the epoxy soybean oil is (0.15-1.5):1.

[0030] Preferably, the phosphate monomer is a functional monomer containing both a double bond and a phosphate group, the phosphate monomer includes at least one of acrylic acid end group phosphate ester, the acrylic acid end group phosphate ester includes Sipomer PAM100, Sipomer PAM200, Sipomer PAM4000. The weight ratio of the phosphate monomer and the epoxy soybean oil is (0.05-0.2):1.

[0031] Preferably, the acid is at least one of volatile acid such as HCl, nitric acid, and the like. The addition amount of the volatile acid is added to the pH of the reaction system to 5-6.

[0032] Preferably, the inert atmosphere is an atmosphere formed by mixing at least one of nitrogen, argon, or helium.

[0033] Conventional photoinitiators in the art can be used in the present application, the photoinitiator includes but is not limited to at least one of the photoinitiator selected from 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, 2-hydroxy-2-methylbenzophenone, phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide.

[0034] Preferably, the pigment can be an organic pigment and / or an inorganic pigment, the organic pigment includes but is not limited to at least one of pigment red 254, phthalocyanine blue BGS; the inorganic pigment includes but is not limited to at least one of carbon black, titanium dioxide, iron red, iron black.

[0035] In the present application, an additive can also be added according to the processing and functional needs, the additive includes but is not limited to at least one or several of a leveling agent, a wetting agent, a defoaming agent, a rheological aid. The leveling agent, the wetting agent, the defoaming agent, and the rheological aid commonly used in the art can be used in the present application.

[0036] The present application also protects the preparation method of the water-based UV insulating coating, comprising the following steps:

[0037] According to the weight parts, the modified epoxy siloxane acrylic polyurethane emulsion, the photoinitiator, the additive, the pigment, and the water are uniformly mixed, and the water-based UV insulating coating can be obtained.

[0038] In order to improve the dispersion uniformity of each component in the coating, the pigment is mixed with water to form a color paste with a solid content of 20-50% before being mixed with the modified epoxy siloxane acrylic polyurethane emulsion, photoinitiator, auxiliary agent and water.

[0039] The application of the above-mentioned water-based UV insulating coating in the corrosion prevention field and / or the insulation field is also within the protection scope of the present application.

[0040] It should be noted that when the water-based UV insulating coating is used, the coating is sprayed onto the surface of the substrate, and is dried at 50-80℃ until the water volatilizes, and then, if the final required dry film thickness is ≦40, the coating can be directly cured and formed into a film under the irradiation of an ultraviolet lamp at 800-2000 mJ / cm 2 If the final required dry film thickness is 60 ≦ dry film thickness ≦ 120, it is recommended to cure the coating by multiple spraying, the curing energy of the previous coating is 300-700 mJ / cm 2 , and the curing energy of the last coating is 800-2000 mJ / cm 2 under the irradiation of an ultraviolet lamp.

[0041] Compared with the prior art, the present application has the following beneficial effects:

[0042] The present application controls the preparation method to obtain the star-shaped epoxy soybean oil prepolymer, and then introduces the acrylate, siloxane segment and mussel myoalbumin into the prepolymer with the star-shaped structure to obtain the insulating resin matrix, so as to improve the electrical performance, heat resistance, mechanical strength and adhesion performance of the coating resin after the coating is cured; further introducing the phosphoric acid group to react with the mussel myoalbumin to generate mussel phosphate can significantly improve the adhesion performance of the coating to the substrate.

[0043] In addition, when a thicker battery insulating paint is prepared, the present application optimizes the spraying times and the curing energy before and after the spraying, so as to greatly eliminate the coating defects, improve the electrical breakdown resistance and mechanical performance of the coating, and greatly improve the yield of the insulating paint. DETAILED DESCRIPTION

[0044] In order to better illustrate the purpose, technical scheme and advantages of the present application, the present application will be further described below in combination with specific examples, but the examples do not limit the present application in any form. Unless otherwise specified, the reagents, methods and devices used in the present application are conventional reagents, methods and devices in the technical field. Unless otherwise specified, the reagents and materials used in the present application are commercially available.

[0045] Example 1

[0046] The present embodiment provides a modified epoxy siloxane acrylic polyurethane emulsion, which is prepared according to the method comprising the following steps:

[0047] S1. Under nitrogen protection, 100 parts by mass of HDI were dissolved in 50 parts of dipropylene glycol dibutyl ether and mixed uniformly, then slowly added to 100 parts by mass of Macrolin E808876 epoxy soybean oil, continuously stirred, and the reaction temperature was controlled at 60°C while reflux condensing, 1 h after dropwise addition was completed, then 2-3 drops of catalyst dibutyl tin dilaurate were added, and incubation reaction was carried out for 6 h, to obtain an isocyanate-terminated star-shaped prepolymer;

[0048] S2. 30 parts by mass of Sigma 481939, 10 parts by mass of chain extender 1,2-dihydroxy-3-propanesulfonic acid sodium, and 10 parts by mass of mussel myoglobin were added to the isocyanate star-shaped prepolymer synthesized in the above step (1), and reacted under nitrogen protection, and continued to react at 60°C for 6 h to obtain a hydrophilic prepolymer terminated by isocyanate;

[0049] S3. 15 parts by mass of hydroxyethyl acrylate were slowly added to the isocyanate-terminated hydrophilic prepolymer synthesized in the above step (2), and reacted under nitrogen protection, and continued to react at 60°C for 4 h to obtain a PU prepolymer terminated by acrylate;

[0050] S4. 30 parts by mass of Sipomer PAM200 were added to the acrylate-terminated PU prepolymer obtained in step (3), hydrochloric acid was added to adjust pH = 5, and continued to react at 40°C for 2 h, and finally self-emulsified by adding deionized water under high-speed stirring to obtain an anti-UV cured epoxy siloxane polyurethane emulsion with a solid content of 65%, which is denoted as modified epoxy siloxane acrylate polyurethane emulsion I.

[0051] Example 2

[0052] The present embodiment provides a modified epoxy siloxane acrylate polyurethane emulsion, which is prepared according to a method comprising the following steps:

[0053] S1. Under nitrogen protection, 160 parts by mass of HMDI were dissolved in 80 parts of propylene glycol methyl ether acetate and mixed uniformly, then slowly added to 100 parts by mass of Rohn R016786 epoxy soybean oil, continuously stirred, and the reaction temperature was controlled at 60°C while reflux condensing, 1 h after dropwise addition was completed, then 2-3 drops of catalyst dibutyl tin dilaurate were added, and incubation reaction was carried out for 6 h, to obtain an isocyanate-terminated star-shaped prepolymer;

[0054] S2. 100 parts by mass of Macrolin 829524 diamino-terminated polymethylsiloxane, 25 parts by mass of chain extender PEG-400, and 30 parts by mass of mussel myoglobin were added to the isocyanate star-shaped prepolymer synthesized in the above step (1), and reacted under nitrogen protection, and continued to react at 60°C for 6 h to obtain a hydrophilic prepolymer terminated by isocyanate;

[0055] S3. Slowly add 80 parts by mass of β-hydroxypropyl methacrylate to the isocyanate-terminated hydrophilic prepolymer synthesized in step (2) above, and react under nitrogen protection, continue to react at 60°C for 4h to obtain an acrylate-terminated PU prepolymer.

[0056] S4. Add 20 parts by weight of Sipomer PAM100 to the acrylate-terminated PU prepolymer obtained in step (3), add nitric acid to adjust pH = 6, continue to react at 40°C for 2h, and finally add deionized water to self-emulsify under high-speed stirring to obtain a modified epoxy siloxane acrylate polyurethane emulsion with a solid content of 65%, which is denoted as modified epoxy siloxane acrylate polyurethane emulsion II.

[0057] Comparative Example 1

[0058] This comparative example provides a modified epoxy siloxane acrylate polyurethane emulsion, which is prepared according to the method of Example 1, and the difference from Example 1 is that no mussel adhesive protein is added in step S2, and after the reaction in step S3 is completed, the reaction in step S4 is not continued, and the emulsion obtained by directly adding water to emulsify is denoted as modified epoxy siloxane acrylate polyurethane emulsion III.

[0059] Comparative Example 2

[0060] This comparative example provides a modified epoxy siloxane acrylate polyurethane emulsion, which is prepared according to the method of Example 1, and the difference from Example 1 is that after the reaction in step S3 is completed, the reaction in step S4 is not continued, and the emulsion obtained by directly adding water to emulsify is denoted as modified epoxy siloxane acrylate polyurethane emulsion IV.

[0061] Comparative Example 3

[0062] This comparative example provides a modified epoxy siloxane acrylate polyurethane emulsion, which is prepared according to the method of Example 1, and the difference from Example 1 is that no mussel adhesive protein is added in step S2, and after the reaction in step S3 is completed, the reaction in step S4 is still continued, and the emulsion obtained is denoted as modified epoxy siloxane acrylate polyurethane emulsion V.

[0063] Comparative Example 4

[0064] This comparative example provides a modified epoxy siloxane acrylate polyurethane emulsion, which is prepared according to the method of Example 1, and the difference from Example 1 is that lauryl acrylate is used instead of Sipomer PAM200 in step S4, and the emulsion obtained by directly adding water to emulsify is denoted as modified epoxy siloxane acrylate polyurethane emulsion VI.

[0065] Application Example

[0066] The modified epoxy siloxane acrylic polyurethane emulsion prepared by using the above examples and comparative examples is prepared into an aqueous UV insulating coating, and is prepared according to the following method comprising the following steps:

[0067] According to the raw material formula described in Table 1, the pigment is first mixed with water to prepare a color paste with a solid content of 50%, and then the modified epoxy siloxane acrylic polyurethane emulsion, the photoinitiator, the additive, the pigment and water are uniformly mixed, to obtain the aqueous UV insulating coating.

[0068] Some raw material information used in the examples and comparative examples of the present application is as follows:

[0069] Pigment: titanium white, commercially available;

[0070] Additive:

[0071] Wetting agent: BYK346, purchased from BYK;

[0072] Defoaming agent: 902w, purchased from Degao;

[0073] Leveling agent: BYK-348, purchased from BYK;

[0074] Table 1 Formulation of the aqueous UV insulating coating (parts by weight)

[0075]

[0076] Performance test

[0077] The performance of the aqueous UV insulating coating obtained by the above examples and comparative examples is characterized, and the specific test items, test methods and results are as follows:

[0078] The above aqueous UV insulating coating is sprayed onto the surface of a metal substrate (6 series aluminum plate or soft rigid), and is dried at 60°C until the water is volatilized, and then is one-coated and cured to form a film under the irradiation of an ultraviolet lamp at 800-2000 mJ / cm 2 , if the final required dry film thickness is ≤40, or is multi-coated and cured, the previous coating curing energy is 300-700 mJ / cm 2 , and the last coating is cured to form a film under the irradiation of an ultraviolet lamp at 800-2000 mJ / cm 2 , if the final required dry film thickness is 60≤dry film thickness≤120.

[0079] The coating thickness is tested by a film thickness meter QNiX4500 to measure the dry film thickness after the coating is cured; the hardness is determined according to GB / T6739-2006; the adhesion is determined according to GB / T9286-1998, wherein the lower the grade number is, the better the adhesion is; the shear strength is tested according to GB / T7124-2008; the impact resistance is tested by using an impact tester; the voltage breakdown resistance is tested by using a voltage breakdown tester BJC-50KV according to GB / T 1695-2005; the high and low temperature resistance is tested by reversing the sample plate at 0℃, 110℃ for 48h and 300℃ for 1h to test the adhesion according to GB9286-98; the electrolyte resistance, 5% HCl resistance and 5% NaOH resistance are tested by immersing the sample plate in electrolyte at room temperature, and the adhesion and discoloration are tested after a specific time; the solvent resistance (95% ethanol) is tested by using a BGD rubbing tester to test the back-and-forth rubbing for 1 minute 30 times under a pressure of 500g, and the discoloration of the coating is observed; and the salt spray resistance is tested according to GB / T1771-2007.

[0080] The test results are shown in Table 2.

[0081] Table 2: Performance test results of the water-based UV insulating coating obtained in the application example

[0082]

[0083] From the above results, it can be seen that:

[0084] The water-based UV insulating coating prepared by the examples 1 and 2 of the present application has excellent adhesive properties, high hardness, good impact performance and high shear strength, and can withstand the long-time jolting of new energy vehicles, and has good electrical insulation performance, strong high and low temperature resistance, good electrolyte corrosion resistance, long chemical resistance and salt spray resistance, and can provide long-time insulation and corrosion protection for square aluminum box batteries even under harsh working conditions, and has good application potential in the field of battery insulation.

[0085] The adhesion and shear strength of the cured film in Comparative Example 1, which does not contain mussel adhesive protein and phosphoric functional groups, are significantly poorer than those of the examples. Since adhesion is a prerequisite for the coating to protect the substrate well, the high-hardness UV coating in Comparative Example 1 is difficult to adhere to the metal substrate due to the absence of mussel adhesive protein, resulting in poor overall performance of the coating. Although Comparative Examples 2 and 4 contain mussel adhesive protein, the absence of phosphoric functional monomer reaction leads to the oxidation and self-polymerization of the active groups in the mussel adhesive protein, greatly weakening the adhesion. Although Comparative Example 3 does not contain mussel adhesive protein, it does contain phosphoric functional groups, which also have the ability to increase adhesion to the metal substrate, so the overall performance of the coating in Comparative Example 3 is improved to some extent compared with Comparative Example 1. Since Comparative Examples 2, 3 and 4 only contain one of the mussel and phosphoric groups, compared with Examples 1 and 2, which contain both the mussel byssus and the phosphoric group reaction to obtain mussel phosphoric ester, there is still a significant gap in overall performance.

[0086] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and are not intended to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application.

Claims

1. An aqueous UV-insulating coating, characterized in that The aqueous UV insulating coating comprises the following components by weight: Modified epoxy siloxane acrylic polyurethane emulsion 50-90 parts; Photoinitiator 1-5 parts; Auxiliary 0-5 parts; Pigment 0.2-2.5 parts; Water to 100 parts; The modified epoxy siloxane acrylic polyurethane emulsion is prepared by the following method: S1. The epoxy soybean oil and diisocyanate, catalyst and hydrophilic solvent are mixed uniformly, and then reacted at 50-70℃ for 4-8h under inert atmosphere to obtain an isocyanate-terminated star-shaped prepolymer; S2. The active H-terminated polymethylsiloxane, mussel myoglobin and hydrophilic chain extender are added to the reaction system obtained in step S1, and then reacted at 50-70℃ for 4-8h under inert atmosphere to obtain a hydrophilic prepolymer terminated by isocyanate; S3. In an inert atmosphere, the hydroxyl-containing acrylic ester monomer is mixed with the isocyanate-terminated hydrophilic prepolymer obtained in step S2, and then reacted completely at 50-80℃ to obtain an acrylic ester-terminated polyurethane prepolymer; S4. In an inert atmosphere, the phosphate monomer is added to the acrylic ester-terminated polyurethane prepolymer obtained in step S3, and then reacted under acid catalysis, and finally emulsified with water to obtain the modified epoxy siloxane acrylic polyurethane emulsion.

2. The aqueous UV-insulating coating according to claim 1, characterized in that At least one of the following characteristics is included: 1) The epoxy soybean oil is at least one of Mcilin E808876, Ron R016786; 2) The diisocyanate includes at least one of toluene diisocyanate, isophorone diisocyanate, diphenyl methane diisocyanate, dicyclohexyl methane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate; 3) The catalyst includes at least one of dibutyltin dilaurate, n-butyl titanate; 4) The hydrophilic solvent includes at least one of dipropylene glycol dimethyl ether, dipropylene glycol dibutyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate, N,N-dimethylformamide; 5) The active H-terminated polymethylsiloxane includes at least one of double-hydroxyl-terminated polymethylsiloxane, double-amino-terminated polymethylsiloxane; 6) The chain extender includes at least one of 1,2-dihydroxy-3-propanesulfonic acid sodium, 1,4-butanediol disulfonic acid sodium, ethylenediamine sulfonic acid sodium, polyethylene glycol, trimethylolpropane polyethylene glycol monomethyl ether; 7) The hydroxyl-containing acrylic ester monomer includes at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, acrylic acid-β-hydroxypropyl ester, methacrylic acid-β-hydroxypropyl ester; 8) The phosphate monomer is a functional monomer containing both double bond and phosphate group, and the phosphate monomer includes at least one of Sipomer PAM100, Sipomer PAM200, Sipomer PAM4000; 9) The acid is a volatile acid, and the volatile acid includes at least one of hydrochloric acid, nitric acid.

3. The aqueous UV-insulating coating according to claim 1, characterized in that At least one of the following characteristics is included: 1) the weight ratio of the diisocyanate and the epoxy soybean oil is (0.8-1.6):1; 2) the weight ratio of the active H-terminated polymethylsiloxane, the mussel myoglobin, the hydrophilic chain extender and the epoxy soybean oil is (0.3-2.0):(0.05-0.3):(0.1-0.5):1; 3) the weight ratio of the hydroxyl-containing acrylate monomer and the epoxy soybean oil is (0.15-1.5):1; 4) the weight ratio of the phosphate monomer and the epoxy soybean oil is (0.05-0.2):1; 5) the acid is a volatile acid, and the addition amount of the volatile acid is to adjust the pH of the reaction system to 5-6.

4. The waterborne UV-insulating coating according to claim 1, characterized in that, The photoinitiator includes at least one of 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, 2-hydroxy-2-methylbenzophenone, and phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide.

5. The waterborne UV-insulating coating according to claim 1, characterized in that, The auxiliary agent includes at least one of a leveling agent, a wetting agent, and a defoaming agent.

6. The waterborne UV-insulating coating according to claim 1, characterized in that, The pigment includes at least one of an organic pigment and an inorganic pigment; the organic pigment includes at least one of pigment red 254 and phthalocyanine blue BGS; and the inorganic pigment includes at least one of carbon black, titanium white powder, iron red, and iron black.

7. Process for the production of the aqueous UV-insulating coating according to any one of claims 1 to 6, characterized in that The method includes the following steps: According to the weight parts, the modified epoxy siloxane acrylic polyurethane emulsion, the photoinitiator, the auxiliary agent, the pigment, and water are uniformly mixed to obtain the water-based UV insulating coating.

8. The preparation method according to claim 7, characterized in that, In the mixing process, the pigment is first mixed with water to form a color paste with a solid content of 20-50%, and then the modified epoxy siloxane acrylic polyurethane emulsion, the photoinitiator, the auxiliary agent, and water are uniformly mixed.

9. The water-based UV insulating coating according to any one of claims 1-6 is applied in the field of corrosion prevention and / or insulation.

10. Use according to claim 9, characterized in that, The water-based UV insulating coating according to any one of claims 1-6 is coated onto the surface of a metal substrate, dried at 50-80°C until the water is volatilized, and then cured into a film under the irradiation of a UV lamp.

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