A kind of elastic texture coating which resists color decay and its preparation method

Abstract

The present invention relates to the technical field of water-based coatings, and in particular to a kind of elastic textured coating resistant to color decay and a preparation method thereof. When preparing the coating, an elastic anti-oxidation UV-absorbing urea monomer and a pyrrolopyrrole diketo pigment derivative containing a carbon-carbon double bond are first prepared, which is then mixed with an acrylate monomer such as methyl methacrylate, and 3-vinyl-1,4-pentadiene is added as a branching center for copolymerization to form a coating with a three-dimensional network structure. The elastic textured coating resistant to color decay of the present invention has the characteristics of good color decay resistance, high elasticity and excellent weather resistance, and the preparation process is controllable, and is suitable for coating requirements in the fields of construction, automobiles, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of water-based coatings, and in particular to an elastic textured coating resistant to color decay and a preparation method thereof. Background Art

[0002] In the field of water-based coatings, coatings that are both elastic and durable are in widespread demand in the fields of construction, automobiles, homes, etc. However, in the existing technology, traditional elastic textured coatings generally have problems such as easy color fading, insufficient resistance to UV aging and antioxidant properties. On the one hand, the pigments and polymer matrices of conventional coatings are mostly physically dispersed and combined, and the pigments are prone to fall off or molecular chain breakage under ultraviolet irradiation, resulting in color degradation; on the other hand, there is a lack of efficient antioxidant groups and ultraviolet absorbing components, or the related components exist in the form of physical mixtures, which are easy to migrate and lose, making it difficult to achieve long-term protection. In addition, the cross-linking structure design of traditional coatings is simple. For example, the linear acrylic system lacks branching centers, resulting in insufficient elasticity or poor weather resistance of the coating, and is prone to cracking and loss of gloss in thermal expansion and contraction or in hot and humid environments.

[0003] While existing technologies have addressed performance improvements by adding UV absorbers or antioxidants, these often suffer from weak group bonding and insufficient synergy. For example, phenolic antioxidants, if not covalently linked to the polymer chain, can easily escape from the system due to solvent erosion or molecular motion. Similarly, pigments, if not chemically anchored, can gradually flake off over time due to environmental factors. Therefore, developing coatings that effectively combine UV- and antioxidant groups with an elastic polymer network, while also achieving a rationally branched structure to impart three-dimensional elasticity and enhance overall performance, has become both a challenging and exciting research topic in this field. Summary of the Invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an elastic textured coating that is resistant to color decay and a preparation method thereof.

[0005] Based on the above objectives, the present invention provides a method for preparing an elastic textured coating that resists color decay, comprising the following steps:

[0006] S1. In a reaction vessel, paeonol is added to acetic acid, the temperature is lowered to 0-5°C, and nitric acid is added dropwise. After the addition is complete, the mixture is returned to room temperature and reacted for 2-3 hours. The reaction solution is added to 0-5°C ice water. The resulting solid is filtered, washed, and dried, then added to methanol. 5% palladium on carbon is added, and the pH is adjusted to 3-4 with 1 mol / L hydrochloric acid solution. The mixture is replaced with hydrogen three times and reacted at room temperature for 3-4 hours. The filtrate is then filtered to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone. The reaction process is schematically shown below:

[0007] Formula (1), the product was characterized by H NMR. The amino group in the product acts as an active group and participates in the subsequent reaction with the isocyanate group. At the same time, the keto configuration in the product structure provides mononuclear conjugation due to the benzene ring. After being excited by ultraviolet light, the molecule enters an excited state, and the proton is rapidly transferred through the hydrogen bond network to form a high-energy enol form. The enol form releases heat energy through non-radiative transition and returns to the ground state keto form, achieving an anti-ultraviolet effect. The chemical process diagram of the conformational transition is as follows:

[0008] Formula (2), the phenolic hydroxyl group in the product directly neutralizes its reactivity by providing hydrogen atoms to free radicals (such as ·OH, ROO·), thereby blocking the oxidation chain reaction. Specifically, the free radical (R·) attacks the hydrogen atom in the phenolic hydroxyl group, causing the phenolic hydroxyl group to lose a hydrogen atom and generate a phenoloxyl free radical (PhO·): Ph-OH+R·→Ph-O·+RH. The generated phenoloxyl free radical (PhO·) is stabilized by the conjugation effect and resonance of the aromatic ring, and its energy is reduced and its activity is greatly weakened. It cannot continue to oxidize and initiate a chain reaction, thereby achieving an antioxidant effect. Finally, the methoxy group in the structure expands the conjugated system of the molecule through the electron-donating conjugation effect, thereby improving the ultraviolet absorption range. Specifically, the oxygen atom in the methoxy group contains a lone pair of electrons, which can form p-π conjugation with the adjacent conjugated group, so that the electron delocalization range is extended to the entire molecular system. This process reduces the energy difference between molecular orbitals, resulting in a reduction in the energy required for electron transition, and the absorption wavelength moves toward the long-wave direction, ultimately expanding the ultraviolet absorption range.

[0009] S2. Add 11-isocyanato-1-undecene and 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone to tetrahydrofuran, cool to 0-5°C, stir and react for 1-3 hours, then return to room temperature and stir and react for 8-10 hours. Add to diethyl ether, collect the precipitate by filtration, wash, and dry to obtain an elastic antioxidant UV-absorbing urea monomer. The chemical reaction equation is as follows:

[0010] Formula (3), the product was characterized by H NMR;

[0011] S3. Under nitrogen protection, the aldehyde-substituted diketopyrrolopyrrole pigment derivative, cyanoacetamide, and a catalyst are added to N,N-dimethylformamide, heated to 100-120°C, reacted for 4-6 hours, cooled to room temperature, filtered, and washed with ethanol until the filtrate is colorless. The filtrate is then washed with deionized water and dried to obtain a diketopyrrolopyrrole pigment derivative containing a carbon-carbon double bond. The chemical reaction equation is as follows:

[0012] Formula (4), the product was characterized by H NMR; the molecular structure of the aldehyde-substituted pyrrolopyrrole diketo pigment derivative is as follows:

[0013] Formula (5), wherein the aldehyde group is independently located at one of the ortho, meta, and para positions of the benzene ring;

[0014] S4. The emulsifier was added to deionized water and stirred for 10-20 min, potassium persulfate was added, the temperature was raised to 60-80 ° C, methyl methacrylate and ethyl acrylate were added dropwise for 1-2 h, and the reaction was continued for 2-4 h after the addition was completed. After cooling to room temperature, a linear acrylic prepolymer emulsion was obtained;

[0015] S5. Add potassium persulfate and dispersant to the linear acrylic prepolymer emulsion, raise the temperature to 70-90°C, add 3-vinyl-1,4-pentadiene, isooctyl acrylate, elastic antioxidant UV-absorbing urea monomer and pyrrolopyrrole dione pigment derivative containing carbon-carbon double bonds, react for 1-3 hours, return to room temperature, adjust the pH to 7-10 with ammonia water, filter, add thickener, anti-sagging agent and defoaming agent to the filtrate, stir evenly to obtain an elastic textured coating that is resistant to color fading.

[0016] Preferably, the weight ratio of paeonol, acetic acid, nitric acid, 0-5°C ice water, methanol, and 5% palladium on carbon in S1 is 1:4-6:1.2-2:6-10:4-6:0.01-0.03.

[0017] Preferably, the weight ratio of 11-isocyanato-1-undecene, 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone, tetrahydrofuran and diethyl ether in S2 is 1:1:8-12:10-20.

[0018] Preferably, the weight ratio of the aldehyde-substituted diketopyrrolopyrrole pigment derivative, cyanoacetamide, catalyst and N,N-dimethylformamide in S3 is 1:1:0.05-0.08:8-12.

[0019] Preferably, for the synthesis method of the aldehyde-substituted pyrrolopyrrole diketo pigment derivative in S3, please refer to the patent (application number 201810464899). In the technical solution disclosed in the patent, this pyrrolopyrrole diketo pigment derivative is condensed with aldehyde-substituted benzonitrile whose aldehyde group is protected by ethylene glycol and diisosuccinate, wherein there are three aldehyde substitution positions, namely, the ortho position, the meta position and the para position on the benzene ring, and the obtained condensation product is hydrolyzed to remove the protection of the aldehyde group by ethylene glycol, and finally a pyrrolopyrrole diketo pigment derivative containing aldehyde groups at different substitution positions is synthesized.

[0020] Preferably, the catalyst in S3 is one of piperidine or 4-methylpiperidine.

[0021] Preferably, the weight ratio of methyl methacrylate, ethyl acrylate, deionized water, emulsifier and potassium persulfate in S4 is 20-30:10-20:100:1-3:0.3-0.5.

[0022] Preferably, the emulsifier in S4 is a mixture of fatty alcohol polyoxyethylene ether and sodium lauryl sulfate in a weight ratio of 1:1.

[0023] Preferably, the linear acrylic prepolymer emulsion, 3-vinyl-1,4-pentadiene, isooctyl acrylate, elastic antioxidant UV-absorbing urea monomer, pyrrolopyrrole dione pigment derivative containing carbon-carbon double bonds, thickener, anti-sagging agent, defoamer, dispersant and potassium persulfate in the S5 are in a weight ratio of 100:0.6-1:20-30:10-20:3-8:0.6-1:0.4-0.6:0.1-0.3:0.4-0.6:0.2-0.6.

[0024] Preferably, the thickener in S5 is one of TEGO3000 and TEGO3030.

[0025] Preferably, the anti-sagging agent in S5 is fumed silica.

[0026] Preferably, the defoaming agent in S5 is one of Defom W-082, XP-502E, and BYK-024.

[0027] Preferably, the dispersant in S5 is one of Disponer W-511, Disponer W-920, and DispexAA4140.

[0028] Furthermore, the present invention also provides an elastic textured coating that is resistant to color decay, which is prepared using the above preparation method.

[0029] Beneficial effects of the present invention:

[0030] 1. The present invention constructs a multiple anti-UV and antioxidant system through molecular design. In the elastic antioxidant UV-absorbing urea monomer, the phenolic hydroxyl group and the methoxy group are conjugated through the benzene ring to form a large π-electron system. The electron-donating effect of the methoxy group expands the UV absorption range. At the same time, the phenolic hydroxyl group can convert light energy into heat energy through the keto-enol conformational transition, effectively dissipating UV energy. The pyrrolopyrrole diketo pigment derivative introduces a carbon-carbon double bond through the reaction of the aldehyde group and cyanoacetamide, and is covalently cross-linked with the polymer network to form a "pigment-polymer" conjugated whole, avoiding the shedding and fading caused by the physical dispersion of the pigment. In addition, the phenolic hydroxyl group can directly capture oxidative free radicals to generate stable phenoloxy free radicals, blocking the oxidative chain reaction. The hydrogen bond network of the urea bond further enhances the molecular stability, achieving dual inhibition of UV aging and oxidative degradation, and significantly extending the color retention period of the coating.

[0031] 2. The present invention constructs a three-dimensional elastic network through the synergistic effect of long-chain alkyl groups and branching centers. The long-chain alkyl groups provided by 11-isocyanato-undecene serve as a flexible skeleton, giving the molecular chain segments freedom of movement. The urea bonds generated by the reaction of its isocyanate groups with amino groups enhance the intermolecular forces through hydrogen bonds, forming a basic network with both flexibility and cohesive strength; 3-vinyl-1,4-pentadiene serves as a branching center, and copolymerizes with acrylic ester monomers through double bonds to introduce branching points into the system, forming a three-dimensional spatial structure of "linear chain-branched cross-linking". This structure enables the coating to dissipate energy through chain segment stretching and branch point deformation when subjected to stress, thereby having both high elongation at break and rapid rebound ability, while avoiding the problem of insufficient rigidity or elasticity loss caused by excessive cross-linking of traditional linear structures, and is suitable for application scenarios with large substrate deformation.

[0032] 3. The present invention improves the comprehensive stability of the coating through chemical crosslinking and physical structure design. The carbon-carbon double bonds of pyrrolopyrrole dione derivatives participate in copolymerization, covalently anchoring the pigment molecules in the acrylic network, inhibiting pigment agglomeration or shedding; high-density branched crosslinking points enhance the density of the coating, reduce water molecule penetration and oxygen diffusion paths, and resist hydrolysis and oxidative corrosion; the hydrophobic effect of long-chain alkyl groups and the polar groups of urea bonds and ester groups form a "hydrophobic barrier-hydrogen bond network" dual protection, improving the coating's resistance to moisture and heat aging; the elastic recovery characteristics of the three-dimensional network structure enable the coating to maintain structural integrity during thermal expansion and contraction, avoiding cracking, loss of gloss or powdering. The above design enables the coating to maintain a smooth surface and stable performance under the influence of multiple environmental factors such as ultraviolet rays, moisture and heat, and mechanical stress.

[0033] 4. This invention utilizes an aqueous dispersion system, avoiding the use of organic solvents and complying with environmental standards. No volatile organic compounds are released during construction, making it suitable for both indoor and outdoor environmentally friendly coating applications. The preparation process utilizes step-by-step control to precisely control the molecular structure and network crosslink density. The raw material ratio and reaction conditions facilitate industrial scale-up, resulting in highly reproducible product performance. Furthermore, by introducing copolymerizable functional monomers, chemical bonding of functional groups such as antioxidants, UV inhibitors, and elasticity enhancers is achieved with the polymer matrix, preventing group loss or performance degradation caused by physical mixing and enhancing the long-term reliability of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The H NMR spectrum of 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone prepared in Example 2 of the present invention;

[0035] Figure 2 This is the H NMR spectrum of the elastic antioxidant UV-absorbing urea monomer prepared in Example 2 of the present invention;

[0036] Figure 3This is the HNMR spectrum of the diketopyrrolopyrrole pigment derivative containing a carbon-carbon double bond prepared in Example 2 of the present invention;

[0037] Figure 4 This is the HNMR spectrum of the diketopyrrolopyrrole pigment derivative containing a carbon-carbon double bond prepared in Example 5 of the present invention;

[0038] Figure 5 This is the HNMR spectrum of the diketopyrrolopyrrole pigment derivative containing a carbon-carbon double bond prepared in Example 6 of the present invention. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0040] The sources of the reagents and raw materials used in the examples of the present invention are as follows:

[0041] Paeonol was purchased from Shanghai MacLean Biochemical Technology Co., Ltd. with a purity of 99%; 5% palladium on carbon was purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd., containing 55% water; 11-isocyanato-1-undecene was purchased from Shanghai MacLean Biochemical Technology Co., Ltd. with a purity of 98%; cyanoacetamide was purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd. with a purity of 98%; potassium persulfate was purchased from Shanghai Bid Pharmaceutical Technology Co., Ltd. with a purity of 99%; methyl methacrylate was purchased from Shanghai MacLean Biochemical Technology Co., Ltd. with a purity of 98%; ethyl acrylate was purchased from Shanghai MacLean Biochemical Technology Co., Ltd. with a purity of 99%; 2-ethylhexyl acrylate was purchased from Shanghai MacLean Biochemical Technology Co., Ltd. with a purity of 99%; 3-vinyl-1- 4-Pentadiene was purchased from Shandong Mopai Biotechnology Co., Ltd. with a purity of 97%; piperidine was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. with a purity of 98%; 4-Methylpiperidine was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. with a purity of 98%; fatty acid polyoxyethylene ether was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. with a purity of biotechnology grade; sodium lauryl sulfate was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. with a purity of 97%; TEG03000 was purchased from Guangzhou Yehusheng Chemical Co., Ltd. with a purity of 99.5%; TEG03030 was purchased from Guangzhou Yehusheng Chemical Co., Ltd. with a purity of 99.5%; fumed silica was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. with a specific surface area of 400 m 2 / g; Defom W-082 was purchased from Shanghai Buding Chemical Co., Ltd.; XP-502E was purchased from Nantong Yongle Chemical Co., Ltd.; BYK-024 was purchased from Shandong Tunan New Materials Co., Ltd.; Disponer W-511 was purchased from Guangzhou Si Tuyuan Chemical Co., Ltd.; Disponer W-920 was purchased from Guangzhou Si Tuyuan Chemical Co., Ltd.; Dispex AA4140 was purchased from Shanghai Kaiyin Chemical Co., Ltd.; 2-Hydroxyacetophenone was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., purity: 98%; 6-Isocyanato-1-hexene was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., purity: 98%; 18-Isocyanato-1-octadecene was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., purity: 98%; Pigment Red 255 was purchased from Henan Alpha Chemical Co., Ltd., purity: 98%.

[0042] Example 1: A specific preparation method of a color-fading-resistant elastic textured coating, comprising the following steps:

[0043] S1. In a reaction vessel, 80 g of paeonol was added to 320 g of acetic acid, cooled to 0 ° C, and then 96 g of nitric acid was added dropwise. After the addition was complete, the mixture was returned to room temperature and reacted for 2 h. The reaction solution was added to 480 g of 0 ° C ice water, and the obtained solid was filtered, washed, and dried, and then added to 320 g of methanol. 0.8 g of 5% palladium carbon was added, and the pH was adjusted to 3 with a 1 mol / L hydrochloric acid solution. The mixture was replaced with hydrogen three times and reacted at room temperature for 3 h. The filtrate was then filtered to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone. After concentration under vacuum, the filtrate was washed and dried to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone.

[0044] S2. 60 g of 11-isocyanato-1-undecene and 60 g of 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone were added to 480 g of tetrahydrofuran, cooled to 0 ° C, stirred for 1 h, then returned to room temperature, stirred for 8 h, added to 600 g of diethyl ether, the precipitate was collected by filtration, washed, and dried to obtain an elastic antioxidant UV absorbing urea monomer;

[0045] S3. Under nitrogen, 40 g of a para-aldehyde-substituted pyrrolopyrrole diketo pigment derivative, 40 g of cyanoacetamide and 1.5 g of piperidine were added to 320 g of N, N-dimethylformamide, heated to 100 ° C, reacted for 4 h, cooled to room temperature, filtered, washed with ethanol until the filtrate was colorless, then washed with deionized water, and dried to obtain a pyrrolopyrrole diketo pigment derivative containing a carbon-carbon double bond;

[0046] S4. 10 g of an emulsifier (a mixture of fatty acid polyoxyethylene ether and sodium lauryl sulfate in a weight ratio of 1:1) was added to 1 kg of deionized water and stirred for 10 min. 3 g of potassium persulfate was then added, the temperature was raised to 60°C, and 200 g of methyl methacrylate and 100 g of ethyl acrylate were added dropwise over a period of 1 h. After the addition was complete, the mixture was reacted for 2 h and cooled to room temperature to obtain a linear acrylic prepolymer emulsion.

[0047] S5. Add 2g of potassium persulfate and 4g of dispersant to the linear acrylic prepolymer emulsion, raise the temperature to 70°C, add 6g of 3-vinyl-1,4-pentadiene, 200g of isooctyl acrylate, 100g of elastic antioxidant UV-absorbing urea monomer and 30g of pyrrolopyrrole dione pigment derivative containing carbon-carbon double bonds, react for 1h, return to room temperature, adjust the pH to 7 with ammonia water, filter, add 6g of thickener, 4g of anti-sagging agent and 1g of defoaming agent to the filtrate, stir evenly to obtain an elastic textured coating that is resistant to color fading.

[0048] Example 2: A specific preparation method of an elastic textured coating that resists color decay, comprising the following steps:

[0049] S1. In a reaction vessel, 100 g of paeonol was added to 500 g of acetic acid, the temperature was lowered to 3 ° C, and 160 g of nitric acid was added dropwise. After the addition was complete, the mixture was returned to room temperature and reacted for 2.5 h. The reaction solution was added to 800 g of 3 ° C ice water. The obtained solid was filtered, washed, and dried, and then added to 500 g of methanol. 2 g of 5% palladium carbon was added, and the pH was adjusted to 3.5 with a 1 mol / L hydrochloric acid solution. The mixture was replaced with hydrogen three times and reacted at room temperature for 3.5 h. The filtrate was then filtered to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone. After concentration under vacuum, the filtrate was washed and dried to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone.

[0050] S2. 90 g of 11-isocyanato-1-undecene and 90 g of 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone were added to 900 g of tetrahydrofuran, cooled to 3 ° C, stirred and reacted for 2 h, then returned to room temperature, stirred and reacted for 9 h, added to 1350 g of diethyl ether, the precipitate was collected by filtration, washed, and dried to obtain an elastic antioxidant UV absorbing urea monomer;

[0051] S3. Under nitrogen, 80 g of a para-aldehyde-substituted pyrrolopyrrole diketo pigment derivative, 80 g of cyanoacetamide and 5.2 g of piperidine were added to 800 g of N, N-dimethylformamide, heated to 110 ° C, reacted for 5 h, cooled to room temperature, filtered, washed with ethanol until the filtrate was colorless, then washed with deionized water, and dried to obtain a pyrrolopyrrole diketo pigment derivative containing a carbon-carbon double bond;

[0052] S4. 20 g of an emulsifier (a mixture of fatty acid polyoxyethylene ether and sodium lauryl sulfate in a weight ratio of 1:1) was added to 1 kg of deionized water and stirred for 15 min. 4 g of potassium persulfate was then added, the temperature was raised to 70 ° C, and 250 g of methyl methacrylate and 150 g of ethyl acrylate were added dropwise over a period of 1.5 h. After the addition was complete, the mixture was reacted for 3 h and cooled to room temperature to obtain a linear acrylic prepolymer emulsion.

[0053] S5. Add 4g of potassium persulfate and 5g of dispersant to the linear acrylic prepolymer emulsion, raise the temperature to 80°C, add 8g of 3-vinyl-1,4-pentadiene, 250g of isooctyl acrylate, 150g of elastic antioxidant UV-absorbing urea monomer and 60g of pyrrolopyrrole dione pigment derivative containing carbon-carbon double bonds, react for 2h, return to room temperature, adjust the pH to 8.5 with ammonia water, filter, add 8g of thickener, 5g of anti-sagging agent and 2g of defoaming agent to the filtrate, stir evenly to obtain an elastic textured coating that is resistant to color fading.

[0054] Example 3: A specific method for preparing an elastic textured coating that resists color decay, comprising the following steps:

[0055] S1. In a reaction vessel, 180g of paeonol was added to 1.08kg of acetic acid, cooled to 5°C, and then 360g of nitric acid was added dropwise. After the addition was complete, the mixture was returned to room temperature and reacted for 3h. The reaction solution was added to 1.8kg of 5°C ice water, and the obtained solid was filtered, washed, and dried, and then added to 1.08kg of methanol. 5.4g of 5% palladium carbon was added, and the pH was adjusted to 4 with a 1mol / L hydrochloric acid solution. The mixture was replaced with hydrogen three times and reacted at room temperature for 4h. The filtrate was then filtered to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone. After concentration under vacuum, the filtrate was washed and dried to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone.

[0056] S2. 150 g of 11-isocyanato-1-undecene and 150 g of 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone were added to 1.8 kg of tetrahydrofuran, cooled to 5 ° C, stirred for 3 h, then returned to room temperature, stirred for 10 h, added to 3 kg of diethyl ether, the precipitate was collected by filtration, washed, and dried to obtain an elastic antioxidant UV absorbing urea monomer;

[0057] S3. Under nitrogen protection, 100 g of a para-aldehyde-substituted pyrrolopyrrole diketo pigment derivative, 100 g of cyanoacetamide and 8 g of piperidine were added to 1.2 kg of N, N-dimethylformamide, heated to 120 ° C, reacted for 6 h, cooled to room temperature, filtered, washed with ethanol until the filtrate was colorless, then washed with deionized water, and dried to obtain a pyrrolopyrrole diketo pigment derivative containing a carbon-carbon double bond;

[0058] S4. 3 g of an emulsifier (a mixture of fatty acid polyoxyethylene ether and sodium lauryl sulfate in a weight ratio of 1:1) was added to 1 kg of deionized water and stirred for 20 min. 5 g of potassium persulfate was then added, the temperature was raised to 80°C, and 300 g of methyl methacrylate and 200 g of ethyl acrylate were added dropwise over a period of 2 h. After the addition was complete, the mixture was reacted for 4 h and cooled to room temperature to obtain a linear acrylic prepolymer emulsion.

[0059] S5. Add 6 g of potassium persulfate and 6 g of dispersant to the linear acrylic prepolymer emulsion, raise the temperature to 90°C, add 10 g of 3-vinyl-1,4-pentadiene, 300 g of isooctyl acrylate, 200 g of elastic antioxidant UV-absorbing urea monomer and 80 g of pyrrolopyrrole dione pigment derivative containing carbon-carbon double bonds, react for 3 hours, return to room temperature, adjust the pH to 10 with ammonia water, filter, add 10 g of thickener, 6 g of anti-sagging agent and 3 g of defoaming agent to the filtrate, stir evenly to obtain an elastic textured coating that is resistant to color fading.

[0060] Example 4: The difference between Example 4 and Example 2 is that piperidine is replaced by 4-methylpiperidine.

[0061] Example 5: The difference between Example 5 and Example 2 is that the diketopyrrolidine pigment derivative substituted with an aldehyde group at the para position is replaced with a diketopyrrolidine pigment derivative substituted with an ortho position.

[0062] Example 6: The difference between Example 6 and Example 2 is that the diketopyrrolidine pigment derivative substituted with an aldehyde group at the para position is replaced with a diketopyrrolidine pigment derivative substituted with an aldehyde group at the meta position.

[0063] Comparative Example 1: The difference between Comparative Example 1 and Example 2 is that steps S1 and S2 in the preparation method are omitted, and paeonol is added together with the thickener, anti-sagging agent and defoaming agent in the last step. The specific steps are as follows: A specific preparation method of an elastic textured coating that resists color decay comprises the following steps:

[0064] S1. Under nitrogen protection, 80 g of a para-aldehyde-substituted pyrrolopyrrole diketo pigment derivative, 80 g of cyanoacetamide, and 5.2 g of piperidine were added to 800 g of N,N-dimethylformamide, heated to 110 ° C, reacted for 5 h, cooled to room temperature, filtered, washed with ethanol until the filtrate was colorless, then washed with deionized water, and dried to obtain a pyrrolopyrrole diketo pigment derivative containing a carbon-carbon double bond;

[0065] S2. 20 g of an emulsifier (a mixture of fatty acid polyoxyethylene ether and sodium lauryl sulfate in a weight ratio of 1:1) was added to 1 kg of deionized water and stirred for 15 min. 4 g of potassium persulfate was then added, the temperature was raised to 70°C, and 250 g of methyl methacrylate and 150 g of ethyl acrylate were added dropwise over a period of 1.5 h. After the addition was complete, the mixture was reacted for 3 h and cooled to room temperature to obtain a linear acrylic prepolymer emulsion.

[0066] S3. Add 4g of potassium persulfate and 5g of dispersant to the linear acrylic prepolymer emulsion, raise the temperature to 80°C, add 8g of 3-vinyl-1,4-pentadiene, 250g of isooctyl acrylate, 75g of 11-isocyanato-1-undecene and 60g of pyrrolopyrrole dione pigment derivative containing a carbon-carbon double bond, react for 2h, return to room temperature, adjust the pH to 8.5 with ammonia water, filter, add 75g of paeonol, 8g of thickener, 5g of anti-sagging agent and 2g of defoaming agent to the filtrate, stir evenly to obtain an elastic textured coating that is resistant to color fading.

[0067] Comparative Example 2: The difference between Comparative Example 2 and Example 2 is that paeonol is replaced by 2-hydroxyacetophenone.

[0068] Comparative Example 3: The difference between Comparative Example 3 and Example 2 is that step S2 in the preparation method is omitted, and 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone is not reacted with 11-isocyanato-1-undecene for grafting. The specific preparation process is as follows: A specific preparation method of an elastic textured coating that resists color fading comprises the following steps:

[0069] S1. In a reaction vessel, 100 g of paeonol was added to 500 g of acetic acid, the temperature was lowered to 3 ° C, and 160 g of nitric acid was added dropwise. After the addition was complete, the mixture was returned to room temperature and reacted for 2.5 h. The reaction solution was added to 800 g of 3 ° C ice water. The obtained solid was filtered, washed, and dried, and then added to 500 g of methanol. 2 g of 5% palladium carbon was added, and the pH was adjusted to 3.5 with a 1 mol / L hydrochloric acid solution. The mixture was replaced with hydrogen three times and reacted at room temperature for 3.5 h. The filtrate was then filtered to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone. After concentration under vacuum, the filtrate was washed and dried to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone.

[0070] S2. Under nitrogen, 80 g of a para-aldehyde-substituted pyrrolopyrrole diketo pigment derivative, 80 g of cyanoacetamide, and 5.2 g of piperidine were added to 800 g of N, N-dimethylformamide, heated to 110 ° C, reacted for 5 h, cooled to room temperature, filtered, washed with ethanol until the filtrate was colorless, then washed with deionized water, and dried to obtain a pyrrolopyrrole diketo pigment derivative containing a carbon-carbon double bond;

[0071] S3. 20 g of an emulsifier (a mixture of fatty acid polyoxyethylene ether and sodium lauryl sulfate in a weight ratio of 1:1) was added to 1 kg of deionized water and stirred for 15 min. 4 g of potassium persulfate was then added, the temperature was raised to 70 ° C, and 250 g of methyl methacrylate and 150 g of ethyl acrylate were added dropwise for 1.5 h. After the addition was complete, the reaction was allowed to proceed for 3 h. After cooling to room temperature, a linear acrylic prepolymer emulsion was obtained.

[0072] S4. Add 4g of potassium persulfate and 5g of dispersant to the linear acrylic prepolymer emulsion, raise the temperature to 80°C, add 8g of 3-vinyl-1,4-pentadiene, 250g of isooctyl acrylate, 75g of 11-isocyanato-1-undecene and 60g of pyrrolopyrrole dione pigment derivative containing a carbon-carbon double bond, react for 2h, return to room temperature, adjust the pH to 8.5 with ammonia water, filter, add 75g of 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone, 8g of thickener, 5g of anti-sagging agent and 2g of defoaming agent to the filtrate, stir evenly to obtain an elastic textured coating that is resistant to color fading.

[0073] Comparative Example 4: The difference between Comparative Example 4 and Example 2 is that 11-isocyanato-1-undecene is replaced by 6-isocyanato-1-hexene.

[0074] Comparative Example 5: The difference between Comparative Example 5 and Example 2 is that 11-isocyanate-1-undecene is replaced by 10-isocyanate-1-octadecene.

[0075] Comparative Example 6: The difference between Comparative Example 6 and Example 2 is that step S3 in the preparation method is omitted and Pigment Red 255 is directly used, and the structure is:

[0076] Formula (6), the specific preparation method is as follows: A specific preparation method of an elastic textured coating that resists color decay, comprising the following steps:

[0077] S1. In a reaction vessel, 100 g of paeonol was added to 500 g of acetic acid, the temperature was lowered to 3 ° C, and 160 g of nitric acid was added dropwise. After the addition was complete, the mixture was returned to room temperature and reacted for 2.5 h. The reaction solution was added to 800 g of 3 ° C ice water. The obtained solid was filtered, washed, and dried, and then added to 500 g of methanol. 2 g of 5% palladium carbon was added, and the pH was adjusted to 3.5 with a 1 mol / L hydrochloric acid solution. The mixture was replaced with hydrogen three times and reacted at room temperature for 3.5 h. The filtrate was then filtered to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone. After concentration under vacuum, the filtrate was washed and dried to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone.

[0078] S2. 90 g of 11-isocyanato-1-undecene and 90 g of 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone were added to 900 g of tetrahydrofuran, cooled to 3 ° C, stirred and reacted for 2 h, then returned to room temperature, stirred and reacted for 9 h, added to 1350 g of diethyl ether, the precipitate was collected by filtration, washed, and dried to obtain an elastic antioxidant UV absorbing urea monomer;

[0079] S3. 20 g of an emulsifier (a mixture of fatty acid polyoxyethylene ether and sodium lauryl sulfate in a weight ratio of 1:1) was added to 1 kg of deionized water and stirred for 15 min. 4 g of potassium persulfate was then added, the temperature was raised to 70 ° C, and 250 g of methyl methacrylate and 150 g of ethyl acrylate were added dropwise for 1.5 h. After the addition was complete, the reaction was allowed to proceed for 3 h. After cooling to room temperature, a linear acrylic prepolymer emulsion was obtained.

[0080] S4. Add 4g of potassium persulfate and 5g of dispersant to the linear acrylic prepolymer emulsion, raise the temperature to 80°C, add 8g of 3-vinyl-1,4-pentadiene, 250g of isooctyl acrylate, 150g of elastic antioxidant UV-absorbing urea monomer and 60g of Pigment Red 255, react for 2h, return to room temperature, adjust the pH to 8.5 with ammonia water, filter, add 8g of thickener, 5g of anti-sagging agent and 2g of defoaming agent to the filtrate, stir evenly to obtain an elastic textured coating that is resistant to color fading.

[0081] Comparative Example 7: The difference between Comparative Example 7 and Example 2 is that 3-vinyl-1,4-pentadiene is not added.

[0082] Comparative Example 8: The difference between Comparative Example 8 and Example 2 is that steps S4 and S5 in the preparation method are combined, and the linear acrylic prepolymer is not prepared in advance. The specific preparation process is as follows: A specific preparation method of an elastic textured coating that resists color decay comprises the following steps:

[0083] S1. In a reaction vessel, 100 g of paeonol was added to 500 g of acetic acid, the temperature was lowered to 3 ° C, and 160 g of nitric acid was added dropwise. After the addition was complete, the mixture was returned to room temperature and reacted for 2.5 h. The reaction solution was added to 800 g of 3 ° C ice water. The obtained solid was filtered, washed, and dried, and then added to 500 g of methanol. 2 g of 5% palladium carbon was added, and the pH was adjusted to 3.5 with a 1 mol / L hydrochloric acid solution. The mixture was replaced with hydrogen three times and reacted at room temperature for 3.5 h. The filtrate was then filtered to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone. After concentration under vacuum, the filtrate was washed and dried to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone.

[0084] S2. 90 g of 11-isocyanato-1-undecene and 90 g of 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone were added to 900 g of tetrahydrofuran, cooled to 3 ° C, stirred and reacted for 2 h, then returned to room temperature, stirred and reacted for 9 h, added to 1350 g of diethyl ether, the precipitate was collected by filtration, washed, and dried to obtain an elastic antioxidant UV absorbing urea monomer;

[0085] S3. Under nitrogen, 80 g of a para-aldehyde-substituted pyrrolopyrrole diketo pigment derivative, 80 g of cyanoacetamide and 5.2 g of piperidine were added to 800 g of N, N-dimethylformamide, heated to 110 ° C, reacted for 5 h, cooled to room temperature, filtered, washed with ethanol until the filtrate was colorless, then washed with deionized water, and dried to obtain a pyrrolopyrrole diketo pigment derivative containing a carbon-carbon double bond;

[0086] S4. Add 20g of emulsifier (fatty acid polyoxyethylene ether and sodium lauryl sulfate mixed in a weight ratio of 1:1) to 1kg of deionized water, stir for 15min, then add 8g of potassium persulfate and 5g of dispersant, raise the temperature to 80°C, add 8g of 3-vinyl-1,4-pentadiene, 250g of isooctyl acrylate, 150g of elastic antioxidant UV-absorbing urea monomer and 60g of pyrrolopyrrole dione pigment derivative containing carbon-carbon double bonds, 250g of methyl methacrylate and 150g of ethyl acrylate, react for 3h, cool to room temperature, adjust the pH to 8.5 with aqueous ammonia, filter, add 8g of thickener, 5g of anti-sagging agent and 2g of defoaming agent to the filtrate, stir evenly to obtain an elastic textured coating that is resistant to color fading.

[0087] Performance testing:

[0088] 1. Elasticity test: The coatings prepared in Examples 1-6 and Comparative Examples 1-8 were evenly coated on a polytetrafluoroethylene plate with a thickness of 3 mm. After drying, the coatings were peeled off to prepare 100 mm × 50 mm specimens. The tensile strength and elongation at break of the specimens were measured using a universal material testing machine at a rate of 10 mm / min. The rebound rate of the coatings was tested using a falling ball rebound tester. , and record the rebound time. The experimental results are shown in Table 1.

[0089] 2. Anti-ultraviolet aging performance test: The coatings prepared in Examples 1-6 and Comparative Examples 1-8 were evenly coated on an aluminum plate. After drying, they were placed in a UV aging test chamber (irradiance 0.68 W / m², temperature 60°C, humidity 50%) and irradiated for 500 hours. The CIELAB color value of the coating was measured before and after the test using a colorimeter, and the CIELAB color value change ΔE was calculated. The smaller the ΔE, the better the UV resistance of the coating. The experimental results are shown in Table 2.

[0090] 3. Antioxidation performance test: The coatings prepared in Examples 1-6 and Comparative Examples 1-8 were evenly coated on an aluminum plate. After drying, they were placed in an oven (80°C, 72h) to simulate an oxidative environment. The tensile strength and elongation at break after aging were measured, and the retention rate was calculated. , the experimental results are shown in Table 2.

[0091] 4. Weathering Resistance Test: The coatings prepared in Examples 1-6 and Comparative Examples 1-8 were evenly coated on a glass plate. After drying, the coatings were tested for specular gloss at a 60° angle using a gloss meter in accordance with the test standard GB / T 9754-2007. The coatings were then placed in a xenon lamp aging test chamber (wavelength 300-800nm, irradiance 1000W / m², temperature 65°C, humidity 60%) for 1000 hours. The coatings were then tested for specular gloss at a 60° angle using a gloss meter again, and the gloss retention was calculated. , and observed the surface condition of the coating. The experimental results are shown in Table 3.

[0092] 5. Ultraviolet Absorption Capacity Test: The coatings prepared in Example 2 and Comparative Example 2 were evenly coated on a quartz glass sheet. After drying, the coatings were scanned in the 200-400 nm wavelength range using a UV-visible spectrophotometer, and the maximum absorption wavelength (λmax) and absorbance (A) were recorded. The experimental results are shown in Table 4.

[0093] Table 1 Elastic properties

[0094]

[0095] Table 2 Anti-ultraviolet / anti-oxidation properties

[0096]

[0097] Table 3 Weather resistance

[0098]

[0099] Table 4 UV absorption capacity

[0100]

[0101] Performance Analysis:

[0102] According to the experimental data in Tables 1-4, the elastic textured coatings prepared by Examples 1-6 using the present invention exhibit significant advantages in elasticity, resistance to UV aging, anti-oxidation and weather resistance, among which Example 2 has the best comprehensive performance.

[0103] In terms of elastic properties, the elastic properties of Example 2 depend on the synergistic effect of the long carbon chain compound and the branching center. This may be because Example 2 is through the long chain alkyl of 11-isocyanato-undecene (11 The isocyanate group of the 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone reacts with the amino group of the 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone to form a urea bond, and the hydrogen bonding of the urea bond enhances the intermolecular force. At the same time, 3-vinyl-1,4-pentadiene serves as a branching center, and its double bond copolymerizes with the acrylic ester monomer to form a three-dimensional network structure, so that the molecular chain can dissipate energy through the flexible extension of the long-chain alkyl group when subjected to force, and can also quickly rebound through cross-linking of the branching points. Comparative Example 4 has strong rigidity and low elongation at break due to insufficient chain length, Comparative Example 5 has reduced elasticity due to excessive entanglement, Comparative Example 7 has a significantly reduced rebound rate due to the lack of energy dissipation nodes in the linear structure, and Comparative Example 8 has uneven branching due to the merging step, and the cross-linking density fluctuates, resulting in reduced strength. The "long-chain flexibility + branched cross-linking" mode of Example 2 achieves optimization of elastic properties.

[0104] In terms of anti-ultraviolet performance, the anti-ultraviolet performance of Example 2 is derived from multiple ultraviolet absorption and energy dissipation mechanisms. This may be because in the elastic antioxidant ultraviolet absorbing urea monomer of Example 2, the phenolic hydroxyl group and the methoxy group are conjugated through the benzene ring to form a large π system. The electron-donating effect of the methoxy group causes the ultraviolet absorption wavelength to red-shift, covering a wider ultraviolet band. At the same time, the pyrrolopyrrole diketone derivative introduces a carbon-carbon double bond through the reaction of the aldehyde group and cyanoacetamide, forming a conjugated extension with the pigment aromatic ring, and is covalently connected to the acrylic acid network through the double bond to form a "urea monomer + pigment" dual ultraviolet absorption barrier. In contrast, in Comparative Example 1, paeonol is not covalently connected to the polymer network through the urea bond. The phenolic hydroxyl group and the methoxy group exist in a physically mixed form, are easy to migrate and lose, and the conjugated system is unstable. In Comparative Example 2, paeonol is replaced by 2-hydroxyacetophenone, which lacks methoxy and urea bonds, has a small conjugated system, a short absorption wavelength, and weak intermolecular forces. In Comparative Example 3, 1-(5-aminophenone) is not covalently connected to the polymer network through the urea bond. The free phenolic hydroxyl compound is loosely bound to the polymer and its conformation is easily destroyed by ultraviolet light. All three cannot form a stable large π conjugated system and an effective energy dissipation mechanism, resulting in a significant reduction in UV resistance. Comparative Examples 4 and 5 replace the isocyanate carbon chain. The short chain causes the conjugated system to have a large steric hindrance and the long chain causes molecular entanglement, both of which destroy the conjugated integrity. Comparative Example 6 does not introduce the carbon-carbon double bond into the pigment. The pigment red 255 used is easy to fall off due to physical dispersion and lacks "pigment-polymer" covalent anchoring. Comparative Example 7 has no 3-vinyl-1,4-pentadiene branching center, the linear structure has low density, and ultraviolet light is easy to penetrate. The merging step of Comparative Example 8 leads to uneven distribution of branching centers, disordered embedding of the conjugated system, and decreased ultraviolet absorption efficiency. The above factors all cause the key anti-ultraviolet structure to fail or weaken, and the final ΔE value is significantly increased.

[0105] In terms of antioxidant performance, the reason for the excellent performance of Example 2 may be due to the free radical capture mechanism of phenolic hydroxyl groups. The phenolic hydroxyl groups of the elastic antioxidant UV-absorbing urea monomer can directly provide hydrogen atoms, neutralize (・OH, ROO・, etc.) oxidative free radicals, generate stable phenolic oxygen free radicals, and block the oxidation chain reaction; at the same time, the carbonyl group and amino group in the urea bond structure form a resonance system, which enhances molecular stability and inhibits oxidative degradation. In contrast, in Comparative Examples 1 and 3, the phenolic hydroxyl groups are not covalently incorporated into the polymer chain through the urea bond. The antioxidant groups exist in a physically mixed or free state and are easily migrated and lost. Comparative Example 2 uses 2-hydroxyacetophenone without amino groups instead. Paeonol cannot form urea bonds to enhance molecular stability. Comparative Examples 4 and 5 have elastic carbon chains that are too short or too long, resulting in distorted or entangled molecular conformations, which weakens the efficiency of capturing phenolic hydroxyl radicals. Comparative Example 6 uses Pigment Red 255 without carbon-carbon double bonds, and the pigment cannot be evenly grafted onto the polymer chain, which easily leads to agglomeration, deterioration of local performance, and accelerated oxidation. Comparative Example 7 has no branching center, and Comparative Example 8 has uneven crosslinking, all due to loose or defective coating structures, which accelerate oxygen penetration and induce oxidative degradation. The above factors reduce the long-term effectiveness or efficiency of the key antioxidant groups, and ultimately lead to a significant decrease in performance retention after aging.

[0106] In terms of weather resistance, Example 2 benefits from the dual stabilization effect of chemical crosslinking and physical structure. The branching center of 3-vinyl-1,4-pentadiene copolymerizes with the acrylic ester monomer to form a high-density crosslinking point, thereby enhancing the density of the coating. The carbon-carbon double bond of the pyrrolopyrrole diketopyrrolidine derivative participates in crosslinking, covalently connecting the pigment molecules to the polymer network to avoid pigment agglomeration or shedding. The hydrophobic effect of the long-chain alkyl group reduces the penetration of water molecules and inhibits hydrolysis and degradation. The urea bond and the polar group of the acrylate group form intermolecular hydrogen bonds, which improves the cohesive energy density of the coating and resists chain breakage and surface cracking caused by xenon lamp aging. The elastic recovery ability of the three-dimensional network structure enables the coating to maintain structural integrity during thermal expansion and contraction. Compared with Example 2, the weather resistance of Comparative Examples 1-8 is reduced. , mainly due to coating structure defects or insufficient chemical cross-linking: Comparative Examples 1, 3, and 6 did not fix the pigment or antioxidant group through covalent bonds, resulting in the physical dispersion of paeonol, pigment, etc., which was easy to fall off and lose, causing powdering and wrinkling. Comparative Examples 2, 4, and 5 had improper replacement groups or carbon chain lengths, which destroyed the molecular conjugation integrity or caused interchain entanglement, and the rigidity was too strong, causing the coating to crack and curl. Comparative Examples 7 and 8 lacked 3-vinyl-1,4-pentadiene branching centers or combined cross-linking steps to form linear structures or uneven cross-linking. The coating had low density and high porosity, and was easily eroded by UV-humidity and heat, resulting in loss of gloss and cracks. The above factors made it impossible for the coating to form a stable three-dimensional covalent cross-linking network and anti-penetration barrier, ultimately leading to a decrease in gloss retention and damage to the surface structure.

[0107] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing an elastic textured coating that resists color decay, characterized in that: The following steps are involved: S1. In a reaction vessel, paeonol is added to acetic acid, the temperature is lowered to 0-5°C, and nitric acid is added dropwise. After the addition is complete, the mixture is returned to room temperature and reacted for 2-3 hours. The reaction solution is added to 0-5°C ice water, the resulting solid is filtered, washed, and dried, and then added to methanol. 5% palladium on carbon is added, and the pH is adjusted to 3-4 with 1 mol / L hydrochloric acid solution. The mixture is replaced with hydrogen three times and reacted at room temperature for 3-4 hours. The filtrate is then filtered to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone. After vacuum concentration, the filtrate is washed and dried to obtain 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone. S2. 11-isocyanato-1-undecene and 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone were added to tetrahydrofuran, cooled to 0-5°C, stirred and reacted for 1-3 hours, then returned to room temperature, stirred and reacted for 8-10 hours, added to diethyl ether, and the precipitate was collected by filtration, washed, and dried to obtain a flexible antioxidant UV-absorbing urea monomer; S3. Under nitrogen protection, an aldehyde-substituted diketopyrrolopyrrole pigment derivative, cyanoacetamide, and a catalyst are added to N,N-dimethylformamide, heated to 100-120°C, reacted for 4-6 hours, cooled to room temperature, filtered, and washed with ethanol until the filtrate is colorless. The filtrate is then washed with deionized water and dried to obtain a diketopyrrolopyrrole pigment derivative containing a carbon-carbon double bond. The molecular structure of the aldehyde-substituted diketopyrrolopyrrole pigment derivative is as follows: Formula (1), wherein the aldehyde group is independently located at one of the ortho, meta, and para positions of the benzene ring; S4. The emulsifier was added to deionized water and stirred for 10-20 min, potassium persulfate was added, the temperature was raised to 60-80 ° C, methyl methacrylate and ethyl acrylate were added dropwise for 1-2 h, and the reaction was continued for 2-4 h after the addition was completed. After cooling to room temperature, a linear acrylic prepolymer emulsion was obtained; S5. Add potassium persulfate and dispersant to the linear acrylic prepolymer emulsion, raise the temperature to 70-90°C, add 3-vinyl-1,4-pentadiene, isooctyl acrylate, elastic antioxidant UV-absorbing urea monomer and pyrrolopyrrole dione pigment derivative containing carbon-carbon double bonds, react for 1-3 hours, return to room temperature, adjust the pH to 7-10 with ammonia water, filter, add thickener, anti-sagging agent and defoaming agent to the filtrate, stir evenly to obtain an elastic textured coating that is resistant to color fading.

2. The method for preparing the color-fading-resistant elastic textured coating according to claim 1, characterized in that: In the S1, the weight ratio of paeonol, acetic acid, nitric acid, 0-5°C ice water, methanol, and 5% palladium on carbon is 1:4-6:1.2-2:6-10:4-6:0.01-0.

03.

3. The method for preparing the color fading resistant elastic textured coating according to claim 1, characterized in that: In the S2, the weight ratio of 11-isocyanato-1-undecene, 1-(5-amino-2-hydroxy-4-methoxyphenyl)ethanone, tetrahydrofuran and diethyl ether is 1:1:8-12:10-20.

4. The method for preparing the color fading resistant elastic textured coating according to claim 1, characterized in that: The weight ratio of the aldehyde-substituted diketopyrrolopyrrole pigment derivative, cyanoacetamide, catalyst and N,N-dimethylformamide in S3 is 1:1:0.05-0.08:8-12.

5. The method for preparing the color fading resistant elastic textured coating according to claim 1, characterized in that: The catalyst in S3 is one of piperidine or 4-methylpiperidine.

6. The method for preparing the color fading resistant elastic textured coating according to claim 1, characterized in that: The weight ratio of methyl methacrylate, ethyl acrylate, deionized water, emulsifier and potassium persulfate in S4 is 20-30:10-20:100:1-3:0.3-0.

5.

7. The method for preparing the color fading resistant elastic textured coating according to claim 1, characterized in that: The emulsifier in S4 is a mixture of fatty alcohol polyoxyethylene ether and sodium lauryl sulfate in a weight ratio of 1:

1.

8. The method for preparing the color fading resistant elastic textured coating according to claim 1, characterized in that: The S5 comprises linear acrylic prepolymer emulsion, 3-vinyl-1,4-pentadiene, isooctyl acrylate, elastic antioxidant UV-absorbing urea monomer, pyrrolopyrrole dione pigment derivative containing carbon-carbon double bonds, thickener, anti-sagging agent, defoamer, dispersant and potassium persulfate in a weight ratio of 100:0.6-1:20-30:10-20:3-8:0.6-1:0.4-0.6:0.1-0.3:0.4-0.6:0.2-0.

6.

9. The method for preparing the color fading resistant elastic textured coating according to claim 1, characterized in that: The thickener in S5 refers to one of TEGO3000 and TEGO3030, the anti-sagging agent refers to fumed silica, the defoaming agent refers to one of Defom W-082, XP-502E, and BYK-024, and the dispersant refers to one of Disponer W-511, Disponer W-920, and Dispex AA4140.

10. An elastic textured coating that resists color fading, prepared by the preparation method according to any one of claims 1 to 9.

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