Anti-ultraviolet aging titanium dioxide modified epoxy resin coating and preparation method thereof

Abstract

The invention relates to the technical field of epoxy resin, and discloses an anti-ultraviolet aging titanium dioxide modified epoxy resin coating. Isocyanated titanium dioxide can react with polycarbonate diol to obtain hydroxyl-terminated polycarbonate modified titanium dioxide, and the hydroxyl-terminated polycarbonate modified titanium dioxide reacts with maleic anhydride to obtain carboxylated polycarbonate modified titanium dioxide; the preparation method comprises the following steps: by taking hindered amine polycarbonate as a raw material, further reacting hindered amine polycarbonate with 2, 2, 6, 6-tetramethyl-4-(oxirane-2-methoxyl) piperidine to obtain hindered amine polycarbonate modified titanium dioxide, and mixing the hindered amine polycarbonate modified titanium dioxide with epoxy resin to obtain the anti-ultraviolet aging titanium dioxide modified epoxy resin coating. The hindered amine group can capture active free radicals generated by photooxidative degradation and inhibit ultraviolet degradation of the composite coating, and the ultraviolet absorption performance of the nano titanium dioxide is matched, so that the ultraviolet aging phenomenon of the composite coating is slowed down, and the ultraviolet aging resistance of the composite coating is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of epoxy resins, in particular to a titanium dioxide modified epoxy resin coating resistant to ultraviolet aging and a preparation method thereof. Background Art

[0002] Epoxy resin is a widely used thermosetting material, which has been gradually applied to various fields of the national economy such as adhesives, casting materials, molding materials and coatings. Among them, epoxy resin coatings have excellent bonding properties, electrical insulation properties and chemical resistance, so they are favored by the public. However, epoxy resin is brittle, has poor impact resistance and is prone to stress cracking. In addition, its resistance to ultraviolet aging cannot meet the market demand, which greatly limits the research and development of epoxy resin. Therefore, it is necessary to modify traditional epoxy resin. Research has found that whether it is filled with inorganic nanomaterials or blended with organic polymer materials, it can have a certain strengthening and toughening effect on epoxy resin. However, there are relatively few reports on combining nanomaterials with organic polymer materials to modify epoxy resin.

[0003] Nano titanium dioxide is a good inorganic ultraviolet absorber. When it is filled into organic polymer materials, a composite hybrid material with excellent mechanical properties and strong anti-ultraviolet aging performance can be generated. For example, Chinese patents such as CN108948657A and CN102690620A disclose a feasible method for blending nano titanium dioxide with epoxy resin to form a hybrid material with excellent comprehensive performance. However, the specific surface area of ​​traditional nano titanium dioxide is small, the ability to absorb ultraviolet energy is not strong, and the dispersibility of nano titanium dioxide is poor, so it is often unable to achieve the ideal modification effect on organic polymer materials. Therefore, it is necessary to modify nano titanium dioxide, and further introduce functional hindered amines and other ultraviolet absorbers or toughening modifiers for organic polymer materials through the hydroxyl groups on its surface, which can enrich the functionality of nano titanium dioxide and further expand its application range. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a titanium dioxide modified epoxy resin coating with UV aging resistance and a preparation method, which solves the problem of poor toughness and UV aging resistance of the epoxy resin coating.

[0005] To achieve the above object, the present invention provides the following technical solution: a titanium dioxide modified epoxy resin coating resistant to ultraviolet aging, wherein the preparation method of the titanium dioxide modified epoxy resin coating resistant to ultraviolet aging comprises the following steps: (1) adding anhydrous toluene solvent, nano-titanium dioxide and toluene-2,4-diisocyanate in a mass ratio of 350-1000:10:2.5-6 into a reactor, mixing them evenly, reacting them at 70-90° C. for 2-8 hours, and cooling the product to obtain isocyanate titanium dioxide; (2) Add ethyl acetate solvent, N-methylpyrrolidone and isocyanate-modified titanium dioxide into the reactor, disperse them uniformly by ultrasonication, continue to add polycarbonate diol and dibutyltin dilaurate, mix them uniformly and transfer them to an oil bath, stir and react at 60-80°C for 4-12h, centrifuge, wash and dry after the reaction to obtain hydroxyl-terminated polycarbonate-modified titanium dioxide; (3) Adding dimethyl sulfoxide solvent and hydroxyl-terminated polycarbonate-modified titanium dioxide into a reactor, dispersing them by ultrasonication until they are completely dissolved, then adding maleic anhydride, mixing them evenly, and transferring them to an oil bath for reaction. After the reaction is completed, centrifuging, washing, and drying are performed to obtain carboxylated polycarbonate-modified titanium dioxide; (4) Add dimethyl sulfoxide solvent and carboxylated polycarbonate modified titanium dioxide to the reactor, perform ultrasonic dispersion for 20-40 minutes, and continue to add 2,2,6,6-tetramethyl-4-(ethylene oxide-2-methoxy)piperidine (C 12 H 23 NO 2 ), after being mixed evenly, transferred to an oil bath pot for reaction, centrifuged after the reaction, washed and dried to obtain hindered amine polycarbonate modified titanium dioxide; (5) Add epoxy resin emulsion, hindered amine polycarbonate modified titanium dioxide, defoaming agent silicone, leveling agent acrylate and curing agent diaminodiphenylmethane into a high-speed mixer, mix well and then package to obtain a titanium dioxide modified epoxy resin coating that is resistant to ultraviolet aging.

[0006] Preferably, in step (2), the mass ratio of ethyl acetate solvent, N-methylpyrrolidone, isocyanate titanium dioxide, polycarbonate diol and dibutyltin dilaurate is 500-1200:200-500:10:15-40:0.01-0.03.

[0007] Preferably, in step (3), the mass ratio of dimethyl sulfoxide solvent, hydroxyl-terminated polycarbonate-modified titanium dioxide and maleic anhydride is 200-850:10:0.8-2.

[0008] Preferably, the reaction temperature in step (3) is 120-140° C. and the reaction time is 2-6 hours.

[0009] Preferably, in step (4), the dimethyl sulfoxide solvent, carboxylated polycarbonate-modified titanium dioxide and 2,2,6,6-tetramethyl-4-(ethylene oxide-2-methoxy)piperidine (C 12H 23 NO 2 )’s mass ratio is 350-1000:10:1.2-4.

[0010] Preferably, the reaction temperature in step (4) is 110-130° C. and the reaction time is 3-12 h.

[0011] Preferably, in step (5), the mass ratio of the epoxy resin emulsion, the hindered amine polycarbonate modified titanium dioxide, the defoaming agent silicone, the leveling agent acrylate and the curing agent diaminodiphenylmethane is 100:8-25:1-3:0.2-1:20-40.

[0012] Compared with the prior art, the present invention has the following beneficial technical effects: The titanium dioxide modified epoxy resin coating resists ultraviolet aging. The surface of the nano titanium dioxide modified by toluene-2,4-diisocyanate contains a large number of isocyanate groups, which can react with the hydroxyl group in the polycarbonate diol under the action of the catalyst dibutyltin dilaurate to obtain the terminal hydroxyl polycarbonate modified titanium dioxide. The terminal hydroxyl group in the structure can undergo a ring-opening esterification reaction with maleic anhydride at high temperature to obtain the carboxylated polycarbonate modified titanium dioxide, and further undergo a ring-opening reaction with the epoxy group in 2,2,6,6-tetramethyl-4-(ethylene oxide-2-methoxy)piperidine at high temperature to obtain the hindered amine polycarbonate modified titanium dioxide. Thus, the polycarbonate toughening macromolecule and the hindered amine ultraviolet absorber are covalently connected on the surface of the nano titanium dioxide through chemical bond connection, thereby effectively enriching the functionality of the nano titanium dioxide and providing convenience for its further application.

[0013] The titanium dioxide modified epoxy resin coating with UV aging resistance is prepared by mixing epoxy resin, hindered amine polycarbonate modified titanium dioxide and various additives. When the composite epoxy resin matrix is ​​subjected to external force, the stress will be gradually transferred from the epoxy resin group to the nano titanium dioxide matrix to form a stress concentration point. As an inorganic nano material with high strength, nano titanium dioxide can absorb a large amount of stress energy and quickly transfer the stress to the polycarbonate molecular chain through chemical bonds, effectively weakening the stress impact on the composite epoxy resin matrix. The damage to the composite epoxy resin matrix, while polycarbonate as a flexible long chain can effectively enhance the ability of the composite epoxy resin matrix to absorb plastic deformation work, further enhancing the toughness of the epoxy resin matrix, and the hindered amine groups grafted on the surface of nano-titanium dioxide can form nitroxide free radicals after absorbing light energy in the presence of oxygen, further capturing the active free radicals produced by photo-oxidative degradation, inhibiting the ultraviolet degradation of the composite epoxy resin coating, and combining with the ultraviolet absorption performance of nano-titanium dioxide to slow down the ultraviolet aging phenomenon of the composite epoxy resin coating, thereby effectively improving the anti-ultraviolet aging performance of the composite epoxy resin coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of 2,2,6,6-tetramethyl-4-(2-methoxyethylene oxide)piperidine. DETAILED DESCRIPTION

[0015] To achieve the above object, the present invention provides the following specific implementation methods and examples: A titanium dioxide modified epoxy resin coating resistant to ultraviolet aging, the preparation method comprising the following steps: (1) adding anhydrous toluene solvent, nano-titanium dioxide and toluene-2,4-diisocyanate in a mass ratio of 350-1000:10:2.5-6 into a reactor, mixing them evenly, reacting them at 70-90° C. for 2-8 hours, and cooling the product to obtain isocyanate titanium dioxide; (2) Add ethyl acetate solvent, N-methylpyrrolidone and isocyanate titanium dioxide to the reactor, disperse them uniformly by ultrasonication, and continue to add polycarbonate diol and dibutyltin dilaurate, wherein the mass ratio of ethyl acetate solvent, N-methylpyrrolidone, isocyanate titanium dioxide, polycarbonate diol and dibutyltin dilaurate is 500-1200:200-500:10:15-40:0.01-0.03, mix them uniformly and transfer them to an oil bath pot, stir and react at 60-80°C for 4-12h, centrifuge after the reaction, wash and dry to obtain terminal hydroxyl polycarbonate modified titanium dioxide; (3) Add dimethyl sulfoxide solvent and terminal hydroxyl polycarbonate modified titanium dioxide into the reactor, disperse by ultrasonic until completely dissolved, and then continue to add maleic anhydride, wherein the mass ratio of dimethyl sulfoxide solvent, terminal hydroxyl polycarbonate modified titanium dioxide and maleic anhydride is 200-850:10:0.8-2. After mixing evenly, transfer to an oil bath pot, react at 120-140°C for 2-6h, centrifuge after the reaction, wash and dry to obtain carboxylated polycarbonate modified titanium dioxide; (4) Add dimethyl sulfoxide solvent and carboxylated polycarbonate modified titanium dioxide to the reactor, perform ultrasonic dispersion for 20-40 minutes, and continue to add 2,2,6,6-tetramethyl-4-(ethylene oxide-2-methoxy)piperidine (C 12 H 23 NO 2 ), wherein dimethyl sulfoxide solvent, carboxylated polycarbonate modified titanium dioxide and 2,2,6,6-tetramethyl-4-(oxirane-2-methoxy)piperidine (C 12 H 23 NO 2 ) in a mass ratio of 350-1000:10:1.2-4, and after being evenly mixed, transferred to an oil bath pot, reacted at 110-130° C. for 3-12 hours, and after the reaction, centrifuged, washed and dried to obtain hindered amine polycarbonate modified titanium dioxide; (5) Add epoxy resin emulsion, hindered amine polycarbonate modified titanium dioxide, defoaming agent silicone, leveling agent acrylate and curing agent diaminodiphenylmethane in a mass ratio of 100:8-25:1-3:0.2-1:20-40 into a high-speed mixer, mix well and encapsulate to obtain a titanium dioxide modified epoxy resin coating that is resistant to ultraviolet aging. Example 1

[0016] (1) Add 210 mL of anhydrous toluene solvent, 5 g of nano-titanium dioxide and 1.25 g of toluene-2,4-diisocyanate into a reactor and mix them evenly. React at 70 °C for 2 h. After the product is cooled, isocyanate titanium dioxide is obtained. (2) Add 280 mL of ethyl acetate solvent, 100 mL of N-methylpyrrolidone, 5 g of isocyanate-modified titanium dioxide into the reactor, disperse them evenly by ultrasonication, continue to add 7.5 g of polycarbonate diol and 0.005 g of dibutyltin dilaurate, mix evenly and transfer to an oil bath, stir and react at 60 ° C for 4 h, centrifuge, wash and dry after the reaction to obtain hydroxyl-terminated polycarbonate-modified titanium dioxide; (3) Add 95 mL of dimethyl sulfoxide solvent and 5 g of terminal hydroxyl polycarbonate modified titanium dioxide into the reactor, disperse by ultrasonic until completely dissolved, then add 0.4 g of maleic anhydride, mix well and transfer to an oil bath, react at 120 °C for 2 h, centrifuge after the reaction, wash and dry to obtain carboxylated polycarbonate modified titanium dioxide; (4) Add 160 mL of dimethyl sulfoxide solvent and 5 g of carboxylated polycarbonate-modified titanium dioxide to the reactor, perform ultrasonic dispersion for 20 min, and then add 0.24 g of 2,2,6,6-tetramethyl-4-(2-methoxyethylene oxide)piperidine (C 12 H 23 NO 2 ), mixed evenly and then transferred to an oil bath, reacted at 110° C. for 3 h, centrifuged, washed and dried after the reaction to obtain hindered amine polycarbonate modified titanium dioxide; (5) Add 50 g of epoxy resin emulsion, 4 g of hindered amine polycarbonate modified titanium dioxide, 0.5 g of defoaming agent silicone, 0.1 g of leveling agent acrylate and 10 g of curing agent diaminodiphenylmethane into a high-speed mixer, mix well and package to obtain a titanium dioxide modified epoxy resin coating that is resistant to ultraviolet aging. Example 2

[0017] (1) Add 300 mL of anhydrous toluene solvent, 5 g of nano-titanium dioxide and 1.8 g of toluene-2,4-diisocyanate into a reactor, mix well, react at 75 ° C for 4 h, and after cooling the product, obtain isocyanate titanium dioxide; (2) Add 400 mL of ethyl acetate solvent, 140 mL of N-methylpyrrolidone and 5 g of isocyanate-modified titanium dioxide into the reactor, disperse them evenly by ultrasonication, continue to add 12 g of polycarbonate diol and 0.008 g of dibutyltin dilaurate, mix evenly and transfer to an oil bath, stir and react at 65 °C for 6 h, centrifuge, wash and dry after the reaction to obtain hydroxyl-terminated polycarbonate-modified titanium dioxide; (3) Add 150 mL of dimethyl sulfoxide solvent and 5 g of terminal hydroxyl polycarbonate modified titanium dioxide into the reactor, disperse by ultrasonic until completely dissolved, then add 0.6 g of maleic anhydride, mix well and transfer to an oil bath, react at 125 °C for 3 h, centrifuge after the reaction, wash and dry to obtain carboxylated polycarbonate modified titanium dioxide; (4) Add 200 mL of dimethyl sulfoxide solvent and 5 g of carboxylated polycarbonate-modified titanium dioxide to the reactor, perform ultrasonic dispersion for 25 min, and then add 0.4 g of 2,2,6,6-tetramethyl-4-(2-methoxyethylene oxide)piperidine (C 12 H 23 NO 2), mixed evenly and then transferred to an oil bath, reacted at 115° C. for 6 h, centrifuged, washed and dried after the reaction to obtain hindered amine polycarbonate modified titanium dioxide; (5) Add 50 g of epoxy resin emulsion, 7 g of hindered amine polycarbonate modified titanium dioxide, 0.8 g of defoaming agent silicone, 0.2 g of leveling agent acrylate and 12 g of curing agent diaminodiphenylmethane into a high-speed mixer, mix well and package to obtain a titanium dioxide modified epoxy resin coating that is resistant to ultraviolet aging. Example 3

[0018] (1) Add 400 mL of anhydrous toluene solvent, 5 g of nano-titanium dioxide and 2.4 g of toluene-2,4-diisocyanate into a reactor, mix well, react at 80 ° C for 6 h, and after cooling the product, obtain isocyanate titanium dioxide; (2) Add 500 mL of ethyl acetate solvent, 200 mL of N-methylpyrrolidone and 5 g of isocyanate-modified titanium dioxide into the reactor, disperse them evenly by ultrasonication, continue to add 16 g of polycarbonate diol and 0.012 g of dibutyltin dilaurate, mix evenly and transfer to an oil bath, stir and react at 70 °C for 8 h, centrifuge, wash and dry after the reaction to obtain hydroxyl-terminated polycarbonate-modified titanium dioxide; (3) Add 260 mL of dimethyl sulfoxide solvent and 5 g of terminal hydroxyl polycarbonate modified titanium dioxide into the reactor, disperse by ultrasonic until completely dissolved, then add 0.8 g of maleic anhydride, mix well and transfer to an oil bath, react at 130 ° C for 4 h, centrifuge after the reaction, wash and dry to obtain carboxylated polycarbonate modified titanium dioxide; (4) Add 300 mL of dimethyl sulfoxide solvent and 5 g of carboxylated polycarbonate-modified titanium dioxide to the reactor, perform ultrasonic dispersion for 30 min, and then add 0.6 g of 2,2,6,6-tetramethyl-4-(oxirane-2-methoxy)piperidine (C 12 H 23 NO 2 ), mixed evenly and then transferred to an oil bath, reacted at 120° C. for 8 h, centrifuged, washed and dried after the reaction to obtain hindered amine polycarbonate modified titanium dioxide; (5) Add 50 g of epoxy resin emulsion, 10 g of hindered amine polycarbonate modified titanium dioxide, 1.2 g of defoaming agent silicone, 0.3 g of leveling agent acrylate and 16 g of curing agent diaminodiphenylmethane into a high-speed mixer, mix well and package to obtain a titanium dioxide modified epoxy resin coating that is resistant to ultraviolet aging. Example 4

[0019] (1) Add 570 mL of anhydrous toluene solvent, 5 g of nano-titanium dioxide and 3 g of toluene-2,4-diisocyanate into a reactor and mix them evenly. React at 90 °C for 8 h. After the product is cooled, isocyanate titanium dioxide is obtained. (2) Add 660 mL of ethyl acetate solvent, 240 mL of N-methylpyrrolidone and 5 g of isocyanate-modified titanium dioxide into the reactor, disperse them evenly by ultrasonication, continue to add 20 g of polycarbonate diol and 0.015 g of dibutyltin dilaurate, mix evenly and transfer to an oil bath, stir and react at 80 °C for 12 h, centrifuge, wash and dry after the reaction to obtain hydroxyl-terminated polycarbonate-modified titanium dioxide; (3) Add 380 mL of dimethyl sulfoxide solvent and 5 g of terminal hydroxyl polycarbonate modified titanium dioxide into the reactor, disperse by ultrasonic until completely dissolved, then add 1 g of maleic anhydride, mix well and transfer to an oil bath, react at 140 ° C for 6 h, centrifuge after the reaction, wash and dry to obtain carboxylated polycarbonate modified titanium dioxide; (4) Add 450 mL of dimethyl sulfoxide solvent and 5 g of carboxylated polycarbonate-modified titanium dioxide to the reactor, perform ultrasonic dispersion for 40 min, and then add 0.8 g of 2,2,6,6-tetramethyl-4-(oxirane-2-methoxy)piperidine (C 12 H 23 NO 2 ), mixed evenly and then transferred to an oil bath, reacted at 130° C. for 12 h, centrifuged, washed and dried after the reaction to obtain hindered amine polycarbonate modified titanium dioxide; (5) Add 50 g of epoxy resin emulsion, 12.5 g of hindered amine polycarbonate modified titanium dioxide, 1.5 g of defoaming agent silicone, 0.5 g of leveling agent acrylate and 20 g of curing agent diaminodiphenylmethane into a high-speed mixer, mix well and package to obtain a titanium dioxide modified epoxy resin coating that is resistant to ultraviolet aging.

[0020] Comparative Example 1 (1) Add 240 mL of anhydrous toluene solvent, 5 g of nano-titanium dioxide and 1.4 g of toluene-2,4-diisocyanate into a reactor and mix them evenly. React at 75 °C for 3 h. After the product is cooled, isocyanate titanium dioxide is obtained. (2) Add 300 mL of ethyl acetate solvent, 120 mL of N-methylpyrrolidone, 5 g of isocyanate-modified titanium dioxide into the reactor, disperse them evenly by ultrasonication, continue to add 8 g of polycarbonate diol and 0.006 g of dibutyltin dilaurate, mix evenly and transfer to an oil bath, stir and react at 65 °C for 5 h, centrifuge, wash and dry after the reaction to obtain hydroxyl-terminated polycarbonate-modified titanium dioxide; (3) Add 50 g of epoxy resin emulsion, 5 g of terminal hydroxyl polycarbonate modified titanium dioxide, 0.6 g of defoaming agent silicone, 0.2 g of leveling agent acrylate and 12 g of curing agent diaminodiphenylmethane into a high-speed mixer, mix well and package to obtain a polycarbonate grafted titanium dioxide modified epoxy resin coating.

[0021] Comparative Example 2 (1) Add 550 mL of anhydrous toluene solvent, 5 g of nano-titanium dioxide and 2.8 g of toluene-2,4-diisocyanate into a reactor and mix them evenly. React at 85 °C for 6 h. After the product is cooled, isocyanate titanium dioxide is obtained. (2) Add 50 g of epoxy resin emulsion, 10 g of isocyanate-modified titanium dioxide, 1 g of defoaming agent silicone, 0.4 g of leveling agent acrylate and 18 g of curing agent diaminodiphenylmethane into a high-speed mixer, mix well and package to obtain titanium dioxide-modified epoxy resin coating.

[0022] The composite coatings in the examples and comparative examples were poured into a mold for curing and injection molded into square specimens with a size of 4 mm×6 cm×6 cm. The fracture strength of the specimens was tested using a JDL-10KN fracture strength tester.

[0023]

[0024] The composite coatings in the examples and comparative examples were poured into a mold for curing and injection molded into square specimens of 4 mm×6 cm×6 cm. They were irradiated with a 300 W ultraviolet lamp for 360 h, and their color difference values ​​were measured using a CM-2300D colorimeter.

[0025]

Claims

1. A titanium dioxide modified epoxy resin coating resistant to ultraviolet aging, characterized in that: The following steps are involved: (1) Anhydrous toluene solvent, nano-titanium dioxide and toluene-2,4-diisocyanate in a mass ratio of 350-1000:10:2.5-6 are mixed evenly, reacted at 70-90° C. for 2-8 hours, and the product is cooled to obtain isocyanate titanium dioxide; (2) adding isocyanate-modified titanium dioxide to a mixed solvent of ethyl acetate and N-methylpyrrolidone, dispersing the mixture evenly by ultrasonication, adding polycarbonate diol and dibutyltin dilaurate, mixing evenly, transferring the mixture to an oil bath, stirring the mixture at 60-80°C for 4-12 hours, centrifuging, washing and drying the mixture after the reaction is completed, and obtaining hydroxy-terminated polycarbonate-modified titanium dioxide; (3) Adding hydroxyl-terminated polycarbonate-modified titanium dioxide to dimethyl sulfoxide solvent, dispersing by ultrasonic until completely dissolved, adding maleic anhydride, mixing evenly and transferring to an oil bath for reaction, centrifuging after the reaction, washing and drying to obtain carboxylated polycarbonate-modified titanium dioxide; (4) Add carboxylated polycarbonate modified titanium dioxide to dimethyl sulfoxide solvent, disperse ultrasonically for 20-40 min, and continue to add 2,2,6,6-tetramethyl-4-(ethylene oxide-2-methoxy)piperidine (C 12 H 23 NO2), mixed evenly and then transferred to an oil bath for reaction. After the reaction, centrifuged, washed and dried to obtain hindered amine polycarbonate modified titanium dioxide; (5) Add epoxy resin emulsion, hindered amine polycarbonate modified titanium dioxide, defoaming agent silicone, leveling agent acrylate and curing agent diaminodiphenylmethane into a high-speed mixer, mix well and then package to obtain a titanium dioxide modified epoxy resin coating that is resistant to ultraviolet aging.

2. The titanium dioxide modified epoxy resin coating with UV aging resistance according to claim 1, characterized in that: In the step (2), the mass ratio of ethyl acetate solvent, N-methylpyrrolidone, isocyanate titanium dioxide, polycarbonate diol and dibutyltin dilaurate is 500-1200:200-500:10:15-40:0.01-0.

03.

3. The titanium dioxide modified epoxy resin coating with UV aging resistance according to claim 1, characterized in that: In the step (3), the mass ratio of the dimethyl sulfoxide solvent, the terminal hydroxyl polycarbonate modified titanium dioxide and maleic anhydride is 200-850:10:0.8-2.

4. The titanium dioxide modified epoxy resin coating with UV aging resistance according to claim 1, characterized in that: The reaction temperature in step (3) is 120-140° C. and the reaction time is 2-6 hours.

5. The titanium dioxide modified epoxy resin coating with UV aging resistance according to claim 1, characterized in that: In the step (4), the dimethyl sulfoxide solvent, carboxylated polycarbonate-modified titanium dioxide and 2,2,6,6-tetramethyl-4-(oxirane-2-methoxy)piperidine (C 12 H 23 The mass ratio of NO2 is 350-1000:10:1.2-4.

6. The titanium dioxide modified epoxy resin coating with UV aging resistance according to claim 1, characterized in that: The reaction temperature in step (4) is 110-130° C. and the reaction time is 3-12 hours.

7. The titanium dioxide modified epoxy resin coating with UV aging resistance according to claim 1, characterized in that: In the step (5), the mass ratio of the epoxy resin emulsion, the hindered amine polycarbonate modified titanium dioxide, the defoaming agent silicone, the leveling agent acrylate and the curing agent diaminodiphenylmethane is 100:8-25:1-3:0.2-1:20-40.

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