Preparation of anti-yellowing auxiliary agent with self-repairing function and application of anti-yellowing auxiliary agent in synthetic leather

Abstract

The invention discloses a urea formaldehyde coated anti-yellowing auxiliary agent with a self-repairing function. The urea formaldehyde coated anti-yellowing auxiliary agent is prepared from the following raw material components: an anti-yellowing agent, a self-repairing functional component, a urea formaldehyde coating layer and a dispersing agent, the benzotriazole ultraviolet light absorber and the hindered amine light stabilizer are combined, so that the yellowing phenomenon of the synthetic leather under ultraviolet irradiation can be effectively delayed; the polymer containing the reversible covalent bond stably exists in the urea formaldehyde coating layer, and the damaged part is repaired; the urea formaldehyde coating layer effectively prevents migration, volatilization and degradation of the yellowing-resistant core component and the self-repairing functional component, and can still keep stable performance of the auxiliary agent and prolong the service life of the synthetic leather in severe environments such as high temperature and high humidity; through unique structural design and component combination, the yellowing resistance of the synthetic leather is remarkably improved, the synthetic leather is endowed with self-repairing capacity, and the service life of a synthetic leather product is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of synthetic leather auxiliaries, and specifically to the preparation of a urea-formaldehyde-coated yellowing-resistant auxiliary with self-healing function and its application in synthetic leather, aiming to improve the comprehensive performance of synthetic leather in complex usage environments. Background Technique

[0002] Synthetic leather is widely used in many fields such as footwear, furniture, and automotive interiors. However, in actual use, it faces problems such as yellowing and surface damage. Yellowing seriously affects the appearance of synthetic leather products, reduces their commercial value, and may lead to a decline in material properties. Although current yellowing-resistant auxiliaries can inhibit yellowing to a certain extent, they have deficiencies in terms of compatibility with the synthetic leather matrix and stability in complex environments. At the same time, damage to the surface of synthetic leather caused by daily friction, scratching, etc. is often difficult to automatically repair, affecting its service life. Developing an auxiliary that not only has excellent yellowing resistance but also can achieve self-healing is of great significance for improving the quality of synthetic leather products. Summary of the Invention

[0003] The purpose of the present invention is to provide a urea-formaldehyde-coated yellowing-resistant auxiliary with self-healing function. Through a unique structural design and component combination, it not only significantly improves the yellowing resistance of synthetic leather but also endows it with self-healing ability, extending the service life of synthetic leather products. At the same time, a method for applying this auxiliary in synthetic leather is provided to facilitate industrial production, so as to solve the problems raised in the above background technique.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] The present invention provides a yellowing-resistant auxiliary with self-healing function, and the raw materials include the following components:

[0006] 1) Yellowing-resistant agent: This yellowing-resistant agent is a composite of an ultraviolet absorber and a hindered amine light stabilizer, and preferably a mixture of a benzotriazole ultraviolet absorber and a hindered amine light stabilizer. The benzotriazole ultraviolet absorber can efficiently absorb ultraviolet rays and convert them into harmless forms such as heat energy and release them, thereby preventing the destruction of synthetic leather molecules by ultraviolet rays. The benzotriazole ultraviolet absorbers selected in the present invention are one or more of UV-1, UV-P, UV-234, UV-312, UV-328, UV-360, UV-384-2, UV-1130, UV-571, UV-928. The hindered amine light stabilizer can react with free radicals generated during the oxidation process, block the oxidation chain reaction, and prevent the yellowing of synthetic leather due to oxidation. The two act synergistically to effectively improve the yellowing resistance performance. The hindered amine light stabilizers selected in the present invention are one or more of LS-119, LS-944, LS-123, LS-292, LS-622, LS-770.

[0007] 2) Self-healing functional component: Introduce polymers containing reversible covalent bonds, such as polyurethane prepolymers modified with furan-maleimide adducts. When damage occurs on the surface of the synthetic leather, under the stimulation of weak external energy (such as environmental heat, light, etc.), the reversible covalent bonds break and recombine, prompting the movement and rearrangement of polymer molecular chains to achieve the repair of the damaged part.

[0008] 3) Urea-formaldehyde coating layer: Urea-formaldehyde is prepared by polycondensation reaction. Its good film-forming property and chemical stability can tightly coat the yellowing-resistant core component and self-healing functional component to form a stable microcapsule structure.

[0009] 4) Dispersant: The dispersant can reduce the surface tension between the additive particles, prevent agglomeration, and ensure the uniform dispersion of the additives in the synthetic leather matrix. In the present invention, one or more of BYK-185, BYK-190, BYK-2010, Tego Dispers 652, Solsperse36600, JF-680, and Tech-5076 are selected.

[0010] The present invention also provides a preparation method of a yellowing-resistant additive with self-healing function, including the following steps:

[0011] (1) Synthesis of self-healing component: After MDI is dissolved, polyethylene glycol is added, and the reaction is carried out for 15 min under nitrogen protection. After cooling, furfurylamine is slowly added, and the reaction is carried out for 30 min. After heating, bismaleimide is added, and the reaction is carried out for 24 h under nitrogen protection to obtain a thermoreversible self-healing polyurethane prepolymer;

[0012] (2) Pretreatment of yellowing-resistant core component and self-healing component: The hindered amine light stabilizer, ultraviolet absorber, and dispersant are dissolved in an organic solvent to form a uniform solution to obtain an organic solution containing the yellowing-resistant core component; the self-healing polyurethane prepolymer obtained in step (1) is dissolved in N,N-dimethylformamide to obtain an organic solution containing the self-healing functional component;

[0013] (3) Synthesis of urea-formaldehyde prepolymer: Urea and formaldehyde solution are mixed in a mass ratio of 1:2, the pH value is adjusted to 8, and the reaction is stirred at 80 °C for 1 hour to obtain a urea-formaldehyde prepolymer solution;

[0014] (4) Coating process: The organic solution containing the yellowing-resistant core component obtained in step (2) is mixed evenly with the organic solution containing the self-healing functional component, and slowly dropped into the urea-formaldehyde prepolymer solution obtained in step (3), and the rotation speed is adjusted to 800 r / min; then, the pH value of the reaction system is adjusted to 4, and the reaction is continued at 60 °C for 2 hours to make the urea-formaldehyde prepolymer undergo a polycondensation reaction to form microcapsules coating the yellowing-resistant core component and self-healing functional component;

[0015] (5) Post-treatment: After the reaction is completed, the reaction product is filtered and washed to remove unreacted raw materials and impurities; the obtained filter cake is vacuum dried at 60° C. for 24 hours to obtain a urea-formaldehyde-coated anti-yellowing additive product with self-repairing function.

[0016] Furthermore, in step (1), the mass ratio of MDI, polyethylene glycol, furfurylamine and bismaleimide is 5:20:2:10.

[0017] Furthermore, in step (2), the mass ratio of the hindered amine light stabilizer, the ultraviolet absorber, the dispersant, and the organic solvent is 15:15:1:20; and the organic solvent is one or more of toluene and xylene.

[0018] Furthermore, in step (2), the mass ratio of the self-healing polyurethane prepolymer to N,N-dimethylformamide is 2:1.

[0019] Furthermore, in step (4), the mass ratio of the organic solution containing the yellowing-resistant core component, the organic solution containing the self-repairing functional component, and the urea-formaldehyde prepolymer solution is 1:1:3.

[0020] The present invention also provides use of the above-mentioned anti-yellowing auxiliary agent with self-repairing function in the preparation of synthetic leather.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. Excellent yellowing resistance: The additive of the present invention combines benzotriazole UV absorbers and hindered amine light stabilizers through a unique anti-yellowing agent formula design, which can effectively delay the yellowing of synthetic leather under ultraviolet irradiation. After professional ultraviolet aging tests, the degree of yellowing of synthetic leather using this additive after long-term irradiation is significantly lower than that of synthetic leather without additives or using traditional additives.

[0023] 2. Significant self-repairing function: The polymer containing reversible covalent bonds exists stably in the urea-formaldehyde coating layer. When slight scratches, abrasions and other damages appear on the surface of the synthetic leather, the reversible covalent bonds will cause the polymer molecular chains to rearrange under the stimulation of environmental energy, thus repairing the damaged parts.

[0024] 3. High stability: The urea formaldehyde coating layer effectively prevents the migration, volatilization and degradation of the yellowing-resistant core components and self-repairing functional components. It can still maintain the stability of the auxiliary performance in harsh environments such as high temperature and high humidity, thereby extending the service life of synthetic leather.

[0025] 4. Simple preparation process and easy industrial production: The preparation method provided by the present invention has a simple operation process, low requirements for equipment, mild reaction conditions, easy to control, and can meet the needs of large-scale industrial production, providing a solid foundation for the wide application of this additive. At the same time, this additive is applicable to a variety of synthetic leather materials and has good versatility and compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a comparison chart of yellowing resistance performance for Example 1, Example 2, Example 3, Comparative Example 1, and Comparative Example 2. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Example 1

[0029] (1) Synthesis of self-healing component: Add 20 g of MDI to a dry three-necked flask and heat it to 45 °C. After it is dissolved, slowly add 80 g of polyethylene glycol. Under the condition of 80 °C, react for 15 min under nitrogen protection. Then cool the temperature to 0 °C and slowly add 8 g of furfurylamine, and react for 30 min. After the reaction is complete, raise the temperature of the system to 65 °C, slowly add 40 g of bismaleimide, and react for 24 h under nitrogen protection to obtain a thermoreversible self-healing polyurethane prepolymer.

[0030] (2) Pretreatment of yellowing resistance core component and self-healing component: Dissolve 15 g of hindered amine light stabilizer LS-119, 15 g of ultraviolet absorber UV-1, and 1 g of dispersant BYK-185 in 20 g of xylene to form a uniform solution; dissolve 20 g of thermoreversible self-healing polyurethane prepolymer in 10 g of N,N-dimethylformamide (DMF) respectively for standby.

[0031] (3) Synthesis of urea-formaldehyde prepolymer: Urea and formaldehyde solution are added to a reaction kettle equipped with a stirring device, a thermometer, and a reflux condenser according to a mass ratio of 1:2, adjust the pH value to 8, and stir and react at 80 °C for 1 hour to obtain a urea-formaldehyde prepolymer.

[0032] (4) Coating process: 20 g of an organic solution containing the core component for yellowing resistance is mixed evenly with 20 g of an organic solution containing the self-healing functional component, and the mixture is slowly added dropwise to 60 g of a urea-formaldehyde prepolymer solution. The rotation speed is adjusted to 800 r / min to uniformly disperse the two in the urea-formaldehyde prepolymer. Then, the pH value of the reaction system is adjusted to 4, and the reaction is continued at 60 °C for 2 hours to cause the urea-formaldehyde prepolymer to undergo a polycondensation reaction, forming microcapsules encapsulating the core component for yellowing resistance and the self-healing functional component.

[0033] (5) Post-treatment: After the reaction is completed, the reaction product is filtered and washed to remove unreacted raw materials and impurities. The obtained filter cake is vacuum dried at 60 °C for 24 h to obtain a urea-formaldehyde coated yellowing resistance aid product with self-healing function.

[0034] Example 2

[0035] (1) Synthesis of self-healing component: 20 g of MDI is added to a dry three-necked flask and heated to 45 °C. After it is dissolved, 80 g of polyethylene glycol is slowly added. Under the condition of 80 °C and nitrogen protection, the reaction is carried out for 15 min. The temperature is lowered to 0 °C and 8 g of furfurylamine is slowly added, and the reaction is carried out for 30 min. After the reaction is complete, the system temperature is raised to 65 °C, and 40 g of bismaleimide is slowly added, and the reaction is carried out for 24 h under nitrogen protection to obtain a thermoreversible self-healing polyurethane prepolymer.

[0036] (2) Pretreatment of the core component for yellowing resistance and the self-healing component: 15 g of the hindered amine light stabilizer LS-944, 15 g of the ultraviolet absorber UV-P, and 1 g of the dispersant BYK-190 are dissolved in 20 g of toluene to form a uniform solution; 20 g of the thermoreversible self-healing polyurethane prepolymer is dissolved in 10 g of N,N-dimethylformamide (DMF), and they are reserved separately.

[0037] (3) Synthesis of urea-formaldehyde prepolymer: Urea and formaldehyde solution are added to a reaction kettle equipped with a stirring device, a thermometer, and a reflux condenser according to a mass ratio of 1:2. The pH value is adjusted to 8, and the reaction is stirred at 80 °C for 1 hour to obtain a urea-formaldehyde prepolymer.

[0038] (4) Coating process: 20 g of an organic solution containing the core component for yellowing resistance is mixed evenly with 20 g of an organic solution containing the self-healing functional component, and the mixture is slowly added dropwise to 60 g of a urea-formaldehyde prepolymer solution. The rotation speed is adjusted to 800 r / min to uniformly disperse the two in the urea-formaldehyde prepolymer. Then, the pH value of the reaction system is adjusted to 4, and the reaction is continued at 60 °C for 2 hours to cause the urea-formaldehyde prepolymer to undergo a polycondensation reaction, forming microcapsules encapsulating the core component for yellowing resistance and the self-healing functional component.

[0039] (5) Post-treatment: After the reaction is completed, the reaction product is filtered and washed to remove unreacted raw materials and impurities. The obtained filter cake is dried in vacuo at 60 °C for 24 h to obtain a urea-formaldehyde-coated anti-yellowing additive product with self-healing function.

[0040] Example 3

[0041] (1) Synthesis of self-healing component: Add 20 g of MDI to a dry three-necked flask and heat it to 45 °C. After it is dissolved, slowly add 80 g of polyethylene glycol. Under the condition of 80 °C and nitrogen protection, react for 15 min. Then cool the temperature to 0 °C and slowly add 8 g of furfurylamine, and react for 30 min. After the reaction is complete, raise the temperature of the system to 65 °C and slowly add 40 g of bismaleimide, and react for 24 h under nitrogen protection to obtain a thermoreversible self-healing polyurethane prepolymer.

[0042] (2) Pretreatment of anti-yellowing core component and self-healing component: Dissolve 15 g of hindered amine light stabilizer LS-2921, 15 g of ultraviolet absorber UV-1130, and 1 g of dispersant Tego Dispers 652 in 20 g of xylene to form a homogeneous solution; dissolve 20 g of thermoreversible self-healing polyurethane prepolymer in 10 g of N,N-dimethylformamide (DMF) respectively for standby.

[0043] (3) Synthesis of urea-formaldehyde prepolymer: Urea and formaldehyde solution are added to a reaction kettle equipped with a stirring device, a thermometer and a reflux condenser according to a mass ratio of 1:2, adjust the pH value to 8, and stir and react at 80 °C for 1 hour to obtain a urea-formaldehyde prepolymer.

[0044] (4) Coating process: Mix 20 g of the organic solution containing the anti-yellowing core component and 20 g of the organic solution containing the self-healing functional component evenly, and slowly drop them into 60 g of the urea-formaldehyde prepolymer solution. Adjust the rotation speed to 800 r / min to make the two evenly disperse in the urea-formaldehyde prepolymer. Then, adjust the pH value of the reaction system to 4 and continue to react at 60 °C for 2 hours to cause the urea-formaldehyde prepolymer to undergo a polycondensation reaction to form microcapsules encapsulating the anti-yellowing core component and the self-healing functional component.

[0045] (5) Post-treatment: After the reaction is completed, the reaction product is filtered and washed to remove unreacted raw materials and impurities. The obtained filter cake is dried in vacuo at 60 °C for 24 h to obtain a urea-formaldehyde-coated anti-yellowing additive product with self-healing function.

[0046] Comparative Example 1

[0047] (1) Pretreatment of anti-yellowing component: Dissolve 15 g of hindered amine light stabilizer LS-119, 15 g of ultraviolet absorber UV-11, and 1 g of dispersant BYK-185 in 20 g of organic solvents such as toluene and xylene to form a homogeneous solution for standby.

[0048] (2) Synthesis of urea - formaldehyde prepolymer: Urea and formaldehyde solution are added to a reaction kettle equipped with a stirring device, a thermometer and a reflux condenser according to a mass ratio of 1:2. The pH value is adjusted to 8, and the reaction is stirred at 80 °C for 1 hour to obtain the urea - formaldehyde prepolymer.

[0049] (3) Coating process: 20 g of an organic solution containing the yellowing - resistant core component is slowly added dropwise to 60 g of the urea - formaldehyde prepolymer solution. The rotation speed is adjusted to 800 r / min to make the two evenly dispersed in the urea - formaldehyde prepolymer. Then, the pH value of the reaction system is adjusted to 4, and the reaction is continued at 60 °C for 2 hours to cause the urea - formaldehyde prepolymer to undergo a polycondensation reaction to form microcapsules coating the yellowing - resistant core component.

[0050] (4) Post - treatment: After the reaction is completed, the reaction product is filtered and washed to remove unreacted raw materials and impurities. The obtained filter cake is vacuum - dried at 60 °C for 24 h to obtain the urea - formaldehyde coated yellowing - resistant additive product.

[0051] Comparative Example 2

[0052] (1) Synthesis of self - healing component: 20 g of MDI is added to a dry three - necked flask and heated to 45 °C. After it is dissolved, 80 g of polyethylene glycol is slowly added. Under the condition of 80 °C and nitrogen protection, the reaction is carried out for 15 min. The temperature is lowered to 0 °C, and 8 g of furfurylamine is slowly added. The reaction is carried out for 30 min. After the reaction is complete, the system temperature is raised to 65 °C, and 40 g of bismaleimide is slowly added. The reaction is carried out for 24 h under nitrogen protection to obtain a thermoreversible self - healing polyurethane prepolymer.

[0053] (2) Pretreatment of yellowing - resistant core component and self - healing component: 15 g of hindered amine light stabilizer LS - 292, 15 g of ultraviolet absorber UV - 1130 and 1 g of dispersant Tego Dispers 652 are dissolved in organic solvents such as toluene and xylene to form a homogeneous solution; 20 g of the polymer containing reversible covalent bonds is dissolved in 10 g of N,N - dimethylformamide (DMF), and they are reserved separately.

[0054] (3) Coating process: 20 g of the organic solution containing the yellowing - resistant core component is mixed evenly with 20 g of the organic solution containing the self - healing functional component, and slowly added dropwise to 60 g of the polyvinyl alcohol solution. The rotation speed is adjusted to 800 r / min to make the two evenly dispersed in the polyvinyl alcohol solution to form microcapsules coating the yellowing - resistant core component and the self - healing functional component.

[0055] (4) Post - treatment: After the reaction is completed, the reaction product is filtered and washed to remove unreacted raw materials and impurities. The obtained filter cake is vacuum - dried at 60 °C for 24 h to obtain the urea - formaldehyde coated yellowing - resistant additive product with self - healing function.

[0056] Test experiment experimental procedure:

[0057] 1. Add 50 g of moisture-curing polyurethane resin (Shanghai Huide Technology Co., Ltd.; HDW-0051) + 50 g of solvent (DMF) + 5 g of titanium dioxide (Sichuan Longmang Group Co., Ltd.; R996) + 1% additive, and disperse for 20 min at 1000 r / min; 2. Take out the release paper, coat the mixed solution on the grooved side, scrape it evenly in parallel with a 15-thread or 25-thread roller, and then put the release paper into the oven and bake for about 5 s; 3. Make leather samples, mark them well, prepare 2 synthetic leathers, 1 for testing the self-healing efficiency, and 1 is placed in a 300 W aging lamp box (Gaotie Technology Co., Ltd.; GT-7035-EUAB yellowing resistance test chamber), observe the color change of the synthetic leather before and after 48 h, and the test results of the yellowing resistance test are shown in Table 1 and Figure 1 as follows.

[0058] Table 1 Test results of the yellowing resistance test

[0059]

[0060] Examples 1, 2, 3, Comparative Example 1, and Comparative Example 2 are placed in a 300 W aging lamp box, and the comparison before and after 48 h of testing is as Figure 1 shown. It can be seen from the pictures before and after the test that the colors of the synthetic leathers in Examples 1, 2, and 3 have basically not changed, while the synthetic leathers in Comparative Examples 1 and 2 have significantly turned yellow, indicating that Examples 1, 2, and 3 have excellent yellowing resistance performance. Looking at Table 1 comprehensively, Examples 1, 2, and 3 show good yellowing resistance performance under the test conditions in this test, while the yellowing resistance performance of Comparative Example 1 and Comparative Example 2 is relatively poor. In Comparative Example 2, when polyvinyl alcohol is used as the coating material for synthetic leather additives, it has deficiencies compared with urea formaldehyde. First, the coating layer formed by polyvinyl alcohol has limited affinity for the yellowing resistance agent and the self-healing component. During the synthetic leather processing, the additive components are likely to migrate out of the coating layer, reducing the long-term effectiveness of the additives, as can be seen from the yellowing resistance effect of Comparative Example 2. At the same time, during the preparation of the synthetic leather, the coating layer swells, affecting the uniform distribution and the effect of the additives in the synthetic leather.

[0061] Artificially make a 0.5 mm deep scratch on the synthetic leathers in Examples 1, 2, 3 and Comparative Example 1. After treating at 150 °C for 300 seconds, it can be observed with the naked eye that the scratches in Examples 1, 2, and 3 gradually heal and the scratches basically disappear. In Comparative Example 1, since it does not contain self-healing components, the scratches remain unchanged.

[0062] The anti-yellowing, mildew-proof and antibacterial additive provided by the present invention, verified by multiple embodiments, can significantly improve the anti-yellowing performance of synthetic leather and at the same time exhibit excellent self-repair effect. Application tests on various synthetic leather materials show that this additive can effectively solve problems such as yellowing and damage faced by synthetic leather during actual use, and has broad market application prospects. Whether in the fields of shoes, luggage, furniture or automotive interiors, etc., it can provide strong support for the quality improvement and performance optimization of synthetic leather products.

[0063] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0064] It should be noted that the above content only illustrates the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. For those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements all fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing an anti-yellowing additive with self-repairing function, characterized in that: The following steps are involved: (1) After MDI is dissolved, polyethylene glycol is added, and the reaction is carried out under nitrogen protection for 15 minutes. After cooling, furfurylamine is slowly added, and the reaction is carried out for 30 minutes. The temperature is raised, and then bismaleimide is added, and the reaction is carried out under nitrogen protection for 24 hours to obtain a thermally reversible self-healing polyurethane prepolymer; (2) dissolving a hindered amine light stabilizer, an ultraviolet absorber, and a dispersant in an organic solvent to form a uniform solution, thereby obtaining an organic solution containing a yellowing-resistant core component; dissolving the self-repairing polyurethane prepolymer obtained in step (1) in N,N-dimethylformamide to obtain an organic solution containing a self-repairing functional component; (3) urea and formaldehyde solution were mixed in a mass ratio of 1:2, the pH value was adjusted to 8, and the mixture was stirred and reacted at 80° C. for 1 hour to obtain a urea-formaldehyde prepolymer solution; (4) uniformly mixing the organic solution containing the yellowing-resistant core component obtained in step (2) and the organic solution containing the self-repairing functional component, and slowly dropping the mixture into the urea-formaldehyde prepolymer solution obtained in step (3), with the rotation speed adjusted to 800 r / min; then, adjusting the pH value of the reaction system to 4, and continuing the reaction at 60° C. for 2 hours to allow the urea-formaldehyde prepolymer to undergo a condensation reaction to form microcapsules encapsulating the yellowing-resistant core component and the self-repairing functional component; (5) After the reaction is completed, the reaction product is filtered and washed to remove unreacted raw materials and impurities; The obtained filter cake was vacuum dried at 60° C. for 24 h to obtain a urea-formaldehyde coated anti-yellowing additive product with self-repairing function.

2. The method for preparing a yellowing resistance additive with self-repairing function according to claim 1, characterized in that: In step (1), the mass ratio of MDI, polyethylene glycol, furfurylamine and bismaleimide is 5:20:2:

10.

3. The method for preparing a yellowing resistance additive with self-repairing function according to claim 1, characterized in that: In step (2), the mass ratio of the hindered amine light stabilizer, the ultraviolet absorber, the dispersant and the organic solvent is 15:15:1:20; and the organic solvent is one or more of toluene and xylene.

4. The method for preparing a yellowing resistance additive with self-repairing function according to claim 3, characterized in that: The hindered amine light stabilizer is one or more of LS-119, LS-944, LS-123, LS-292, LS-622, and LS-770; the ultraviolet absorber is one or more of UV-1, UV-P, UV-234, UV-312, UV-328, UV-360, UV-384-2, UV-1130, UV-571, and UV-928; and the dispersant is one or more of BYK-185 / BYK-190 / BYK-2010 / Tego Dispers652 / Solsperse 36600 / JF-680 / Tech-5076.

5. The method for preparing a yellowing resistance additive with self-repairing function according to claim 1, characterized in that: In step (2), the mass ratio of the self-healing polyurethane prepolymer to N,N-dimethylformamide is 2:

1.

6. The method for preparing a yellowing resistance additive with self-repairing function according to claim 1, characterized in that: In step (4), the mass ratio of the organic solution containing the yellowing-resistant core component, the organic solution containing the self-repairing functional component, and the urea-formaldehyde prepolymer solution is 1:1:

3.

7. An anti-yellowing additive with self-repairing function prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the anti-yellowing additive with self-repairing function as claimed in claim 7 in the preparation of synthetic leather.

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