Self-repairing tire inner coating sealant material and preparation method thereof

Abstract

The invention provides a self-repairing tire inner coating sealant material and a preparation method thereof, the sealant material adopts a three-layer composite coating structure, and the sealant material sequentially comprises an anti-puncture coating, an anti-leakage self-repairing coating and a noise reduction and sound insulation coating from the inner wall of a tire to the inner side of the tire. The defects of failure at a low temperature of-15 DEG C, easiness in melting and falling at a high temperature of 90 DEG C and short service life of the existing tire internally coated with sealant are overcome. The bottom layer anti-puncture coating is formed by compounding Hua Da 1044 / 44 polyester polyol and diisocyanate, the hardness reaches Shore A90, and the bottom layer anti-puncture coating is excellent in anti-puncture performance; the middle-layer leakproof self-repairing coating and the inner-layer noise-reducing and sound-insulating coating adopt polyether polyol with specific molecular weight and an amine chain extender, so that stable work in a wide temperature range from-45 DEG C to 90 DEG C is realized, the self-repairing response is quick, and the airtight effect is good; the service life of the product is prolonged to 8 years, and the product can be directly coated on the inner wall of a tire for use and is suitable for sealing protection of various motor vehicle tires.

Description

Technical Field

[0001] This invention belongs to the field of self-healing tire technology, and particularly relates to a self-healing tire inner coating sealant and its preparation method. Background Technology

[0002] Tire internal sealant is a functional material coated on the inner wall of a tire. Through its self-healing and sealing properties, it automatically seals the tire after a foreign object punctures, preventing the risk of tire blowout and improving driving safety. Existing tire internal sealants are mostly made from polyether polyols and isocyanates as base materials, combined with chain extenders. However, they have significant technical drawbacks: at low temperatures (below -15℃), the sealant loses its resilience and repair capabilities, making it unsuitable for use in cold regions; at temperatures exceeding 90℃, the sealant easily melts and detaches, losing its airtight effect; and its service life is relatively short, lasting only 3 years or 60,000-90,000 kilometers, requiring frequent reapplication or tire replacement, resulting in high operating costs. These shortcomings limit the application scenarios and promotion of tire internal sealants. Therefore, there is an urgent need to develop a self-healing tire internal sealant material with a wide temperature range, strong durability, and stable coating effect. Summary of the Invention

[0003] This invention addresses the problems of poor low-temperature resistance, easy failure at high temperatures, and short service life of existing tire inner coating sealants by providing a self-healing tire inner coating sealant with a wide temperature range of -45℃ to 90℃, a service life of up to 8 years, and the ability to be stably coated on the inner wall of tires, as well as its preparation method.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A self-healing tire inner coating sealant has a three-layer composite coating structure, consisting of a puncture-resistant coating, a leak-proof self-healing coating, and a noise-reducing and sound-insulating coating, from the inner wall of the tire to the inner side of the tire. The puncture-resistant coating comprises the following components by mass fraction: 550-760 parts of polyester polyol I, 180-230 parts of polyester polyol II, 180-230 parts of diisocyanate, and 11-15 parts of chain extender; wherein the molecular weight of polyester polyol I and polyester polyol II is 800-2200, the diisocyanate is selected from one or more of MDI, TDI, PPDI, IPDI, and XDI, and the chain extender is an amine chain extender; The leak-proof self-healing coating is a two-component system. Component A contains 450-550 parts of polyether polyol I, 450-550 parts of polyether polyol II, 1-5 parts of catalyst, and 1-5 parts of antioxidant. Component B contains 210-300 parts of polyether polyol I, 210-300 parts of polyether polyol II, 450-550 parts of diisocyanate, and 1-5 parts of catalyst. The polyether polyols are bifunctional or multifunctional and have a molecular weight of 1000-5000. The noise reduction and sound insulation coating is a two-component system. Component A contains 260-330 parts of polyether polyol I, 120-180 parts of polyether polyol II, 120-180 parts of polyether polyol III, 350-450 parts of plasticizer, 1-5 parts of catalyst, and 1-5 parts of antioxidant. Component B contains 160-230 parts of polyether polyol I, 160-230 parts of polyether polyol II, 90-120 parts of diisocyanate I, 90-120 parts of diisocyanate II, 1-5 parts of catalyst, and 350-450 parts of plasticizer. The molecular weight of the polyether polyol is 2000-6000.

[0005] As a preferred option, the mass ratio of raw materials for each layer is as follows: Puncture-resistant coating: 600 parts polyester polyol I, 200 parts polyester polyol II, 200 parts diisocyanate, and 11-15 parts chain extender; Leak-proof self-healing coating: Component A: 500 parts polyether polyol I, 500 parts polyether polyol II, 1-5 parts catalyst, 1-5 parts antioxidant; Component B: 250 parts polyether polyol I, 250 parts polyether polyol II, 500 parts diisocyanate, 1-5 parts catalyst. Noise-reducing and sound-insulating coating component A: 300 parts polyether polyol I, 150 parts polyether polyol II, 150 parts polyether polyol III, 400 parts plasticizer, 1-5 parts catalyst, 1-5 parts antioxidant; component B: 200 parts polyether polyol I, 200 parts polyether polyol II, 100 parts diisocyanate I, 100 parts diisocyanate II, 1-5 parts catalyst, 400 parts plasticizer.

[0006] As a preferred option, the polyester polyol I in the puncture-resistant coating is CMA-1044 polyester polyol produced by Huada Chemical Group, and the polyester polyol II is CMA-44 polyester polyol produced by Huada Chemical Group. Both of them contain bifunctional groups and form a high-density cross-linked structure after reacting with amine chain extenders, thus ensuring puncture resistance.

[0007] Preferably, the plasticizer in the noise reduction and sound insulation coating is DOP or DBP, and the antioxidant is a phosphite antioxidant adapted to the polyurethane system. Its core function is to inhibit the thermal oxidative degradation of polyether polyol and polyurethane molecular chains. It has good compatibility with polyether polyol and plasticizer (DOP / DBP). The catalyst is a tertiary amine polyurethane catalyst. The amine chain extender is selected from aliphatic amines or aromatic amines, preferably one or more of ethylenediamine, diethylenetriamine, and MDA, to ensure the balance between the crosslinking density and flexibility of the polyurethane molecular chains.

[0008] Preferably, the puncture-resistant coating has a Shore A90 hardness and a coating thickness of 1-2 mm; the leak-proof self-healing coating has a coating thickness of 2-2.5 mm; and the noise-reducing and sound-insulating coating has a coating thickness of 1-2 mm.

[0009] This invention also proposes a method for preparing the above-mentioned self-healing tire inner coating sealant, comprising the following steps: Preparation of puncture-resistant coating: Polyester polyol I and polyester polyol II are heated to 45°C under nitrogen protection, diisocyanate is added and then the temperature is raised to 80-90°C. The mixture is stirred for 2-3 hours. When the NCO content of the system reaches 10.5-11.5%, a chain extender is added and stirred. Vacuum degassing is performed to obtain the puncture-resistant coating material. Preparation of leak-proof self-healing coating: Polyether polyol I and polyether polyol II in component B are vacuum dehydrated for 1.5-2 hours, heated to 45°C under nitrogen protection, diisocyanate and catalyst are added, and then heated to 80-90°C and stirred for 2-3 hours. When the NCO content of the system reaches 10.5-12%, a prepolymer is obtained. Component A is mixed completely, heated to 50-70°C and stirred for 1-2 hours to obtain the chain-extended modified component. The prepolymer and the chain-extended modified component are mixed at a mass ratio of 1:5-6 and stirred evenly. Vacuum degassing is then performed to obtain the leak-proof self-healing coating material. Preparation of noise reduction and sound insulation coating: Polyether polyol I and polyether polyol II in component B are vacuum dehydrated for 1.5-2 hours, heated to 45°C under nitrogen protection, diisocyanate I and diisocyanate II, catalyst and plasticizer are added, and the mixture is heated to 80-90°C and stirred for 2-3 hours. When the NCO content of the system reaches 8.5-9.5%, the prepolymer is obtained. Component A is mixed completely, heated to 40-60°C and stirred for 1-2 hours to obtain the chain extension modified component. The prepolymer and the chain extension modified component are mixed at a mass ratio of 1:6-8 and stirred evenly. Vacuum degassing is then performed to obtain the noise reduction and sound insulation coating material.

[0010] Preferably, the mixing ratio of components A and B in the leak-proof self-healing coating is 100:14-17, and the mixing ratio of components A and B in the noise reduction and sound insulation coating is 100:17-19.

[0011] Preferably, the catalyst is added at a rate of 0.1-0.5% of the total mass of the raw materials for each layer of rubber compound.

[0012] The present invention also proposes a self-healing tire, wherein the inner wall of the tire is sequentially coated with the above-mentioned puncture-resistant coating, leak-proof self-healing coating and noise-reducing and sound-insulating coating, and the coating process adopts the above-mentioned method.

[0013] This invention employs a three-layer composite coating structure design, with each layer of rubber having a clear function and working synergistically to achieve sealing and self-healing functions when directly coated onto the inner wall of the tire. Puncture-resistant coating: Huada 1044 / 44 polyester polyol is compounded with a specific diisocyanate and amine chain extender to form a high-strength, high-tear-resistant protective rubber with a Shore A90 hardness, which is higher than the hardness of tire rubber. It can effectively resist foreign object puncture and provide protection for the inner layer seal. Leak-proof self-healing coating: It adopts a two-component polyether polyol system, combined with special catalysts and antioxidants, to give the adhesive rapid shape recovery and self-healing function. After puncture, it can quickly wrap foreign objects and prevent gas leakage. Noise-reducing and sound-insulating coating: Designed with an ultra-low hardness semi-gel state as the goal, the coating optimizes the molecular weight of polyether polyol and the ratio of plasticizer, mainly to improve the sound insulation and noise reduction function, while enhancing the airtight sealing effect.

[0014] Each layer of the adhesive material is prepared through precise proportioning and specific processes. The catalyst is a tertiary amine polyurethane catalyst, the antioxidant is a phosphite antioxidant, and the plasticizer is DOP / DBP, which ensures the stability of the adhesive material under extreme temperatures, making it less prone to peeling after coating and extending its service life to 8 years.

[0015] Compared with the prior art, the advantages and positive effects of the present invention are as follows: The self-healing tire inner coating sealant of this invention has a wide temperature resistance range and can work stably in environments from -45℃ to 90℃. It does not lose its repair ability at low temperatures and does not melt or fall off at high temperatures, making it suitable for tire use needs under different climatic conditions. With excellent self-healing and sealing performance, the three-layer coating structure works synergistically to achieve puncture prevention, foreign object wrapping, and nail hole sealing in stages, resulting in good airtightness, rapid repair response, and effective prevention of tire leakage. The rubber compound adheres tightly to the inner wall of the tire, making it difficult to fall off even after long-term use, with a service life of up to 8 years, far exceeding existing products; Each layer of adhesive is prepared using conventional reaction equipment, with mild operating conditions and a convenient coating process, making it suitable for industrial-scale mass application. Detailed Implementation

[0016] To better understand the present invention, specific details are provided below with reference to embodiments. Example 1

[0017] A method for preparing a self-healing tire inner sealant includes the following steps: 1. Raw material preparation Puncture-resistant coating raw materials: 600 parts of polyester polyol I (Huada 1044), 200 parts of polyester polyol II (Huada 44), 200 parts of diisocyanate (MDI), and 13 parts of amine chain extender; Leak-proof self-healing coating raw materials: Component A: 500 parts of polyether polyol I (bifunctional, molecular weight 2000), 500 parts of polyether polyol II (trifunctional, molecular weight 4000), 3 parts of catalyst (Shanghai Zhengui New Material Technology Co., Ltd. H05 type, main component is triethylenediamine modified material) (0.3% of the total mass of component A), and 3 parts of antioxidant (BASF IRGAFOS 168, Germany) (0.3% of the total mass of component A). Component B: 250 parts of polyether polyol I (bifunctional, molecular weight 2000), 250 parts of polyether polyol II (trifunctional, molecular weight 4000), 500 parts of diisocyanate (TDI), and 3 parts of catalyst (H05 type from Shanghai Zhengui New Material Technology Co., Ltd.) (0.3% of the total mass of component B). Raw materials for noise reduction and sound insulation coating: Component A: 300 parts of polyether polyol I (bifunctional, molecular weight 3000), 150 parts of polyether polyol II (bifunctional, molecular weight 4000), 150 parts of polyether polyol III (bifunctional, molecular weight 6000), 400 parts of plasticizer (DOP), 3 parts of catalyst (H08 type from Shanghai Zhengui New Material Technology Co., Ltd.) (0.3% of the total mass of component A), and 3 parts of antioxidant (IRGAFOS 168 from BASF, Germany) (0.3% of the total mass of component A). Component B: 200 parts of polyether polyol I (bifunctional, molecular weight 3000), 200 parts of polyether polyol II (bifunctional, molecular weight 4000), 100 parts of diisocyanate I (IPDI), 100 parts of diisocyanate II (XDI), 3 parts of catalyst (H08) (0.3% of the total mass of component B), and 400 parts of plasticizer (DOP); Auxiliary equipment: vacuum dehydrator, nitrogen-protected reaction vessel, high-speed stirrer, vacuum degassing machine, coating equipment (scraper coating machine), Shore hardness tester, NCO content analyzer.

[0018] 2. Preparation of each layer of adhesive 2.1 Preparation of puncture-resistant coating compound Raw material pretreatment: Polyester polyol I (Huada 1044) and polyester polyol II (Huada 44) were respectively put into a vacuum dehydrator and vacuum dehydrated for 2 hours at 80℃ and -0.09MPa to remove moisture from the raw materials (ensuring moisture content <0.03%) to avoid affecting subsequent reactions; Prepolymer preparation: Dehydrated polyester polyols I and II were added to a nitrogen-protected reactor in proportion, and stirring was started (300 r / min). The nitrogen flow rate was controlled at 0.5 L / min. The temperature was raised to 45℃ and held for 15 min. Then, MDI was slowly added dropwise at a rate of 5 parts / min, and the temperature was kept stable at 45±2℃ during the addition. After the addition was completed, the temperature was gradually raised to 85℃ and stirred for 2.5 h. During this period, samples were taken every 30 min. The NCO content of the system was determined by di-n-butylamine titration. When the NCO content reached 11.0%, the heating was stopped. Chain extension and degassing: The temperature of the reactor was lowered to 60℃, amine chain extender was added, the stirring speed was adjusted to 500r / min, and the mixture was stirred for 30min until the chain extender was completely dissolved and the system was uniform and free of particles; then the material was transferred to a vacuum degassing machine and degassed for 40min at -0.095MPa and 50℃ to remove air bubbles from the material, and the puncture-resistant coating material was sealed for later use.

[0019] 2.2 Preparation of Leak-Proof Self-Healing Coating Material Preparation of component B (prepolymer): Raw material dehydration: Polyether polyols I and II from component B are fed into a vacuum dehydrator and dehydrated under vacuum at 100℃ and -0.09MPa for 1.8 hours to ensure a moisture content of <0.03%; Prepolymerization reaction: Dehydrated polyether polyols I and II were added to a nitrogen-protected reactor and stirred at 250 r / min. The temperature was raised to 45°C under nitrogen protection. TDI was slowly added at a dropping rate of 3 parts / min. After the addition, the temperature was raised to 85°C and stirred for 2.5 h. The NCO content was measured periodically. When the NCO content reached 11.2%, the reaction was stopped, the temperature was lowered to 50°C, catalyst H05 was added, and the mixture was stirred for 15 min to obtain the prepolymer of component B, which was then sealed and stored. Preparation of Component A (Chain Extender / Modifier): Mixing and stirring: Add polyether polyols I and II and antioxidants from component A to a stirring vessel, heat to 60°C, stir at 400 r / min, and mix for 1.5 h. During this period, check the uniformity of the system every 20 min to ensure no stratification and no precipitation. Catalyst addition: Cool to 40℃, add catalyst H05, and continue stirring for 20 min to obtain component A, which is then sealed for later use. Mixing the adhesive: Before use, add the two components (A and B) to a high-speed mixer at a mass ratio of 100:15 and stir for 10 minutes at 800 r / min until the system is uniform in color and free of flocculation. Then transfer it to a vacuum degassing machine and degas for 30 minutes at -0.09 MPa and 45°C to obtain the leak-proof self-healing coating adhesive, which can be used immediately.

[0020] 2.3 Preparation of Noise Reduction and Sound Insulation Coating Adhesive Preparation of component B (prepolymer): Raw material dehydration: Polyether polyols I and II from component B were fed into a vacuum dehydrator and dehydrated under vacuum at 90℃ and -0.09MPa for 1.5 hours, with the moisture content controlled at <0.03%; Prepolymerization reaction: Dehydrated polyether polyols I and II were added to a nitrogen-protected reactor, and plasticizer DOP was added. The stirring speed was 250 r / min, and the temperature was raised to 45℃ under nitrogen protection. IPDI and XDI (mixed at a mass ratio of 1:1) were slowly added at a dropping rate of 2 parts / min. After the addition, the temperature was raised to 85℃ and stirred for 2.5 h. The NCO content was measured by sampling. When the NCO content reached 9.0%, the reaction was stopped, the temperature was lowered to 45℃, catalyst H08 was added, and the mixture was stirred for 15 min to obtain component B prepolymer, which was then sealed and stored. Preparation of Component A (Chain Extender / Modifier): Add polyether polyols I, II, and III, plasticizer DOP, and antioxidant from component A to a stirred tank, heat to 50°C, stir at 350 r / min, and mix for 1.5 h to ensure complete fusion of all components; cool to 35°C, add catalyst H08, and continue stirring for 20 min to obtain the chain-extended modified component A, which is then sealed for later use. Mixing the adhesive: Before use, add the two components (A and B) to a high-speed mixer at a mass ratio of 100:18 and stir for 12 minutes at 900 r / min until the system is a homogeneous gel. Transfer the mixture to a vacuum degassing machine and degas for 40 minutes at -0.095 MPa and 40°C to remove microbubbles and obtain the noise reduction and sound insulation coating adhesive, which can be used immediately.

[0021] The self-healing tire inner coating sealant prepared by the above method was applied to the inner wall of the tire according to the following steps, and its performance was tested. The specific steps are as follows: (1) Tire pretreatment: Select a passenger car tire with a specification of 195 / 65R15, remove impurities and oil stains from the inner wall, and lightly sand it with sandpaper (roughness Ra=0.8-1.2μm) to enhance the adhesion of the rubber compound; then wipe the inner wall with anhydrous ethanol and let it air dry naturally; (2) Puncture-resistant coating: Pour the prepared puncture-resistant coating material into the material tank of the coating equipment, use a scraper coating machine, adjust the scraper gap to 1.5mm, and coat a layer evenly on the inner wall of the tire at a speed of 5m / min; after coating, put the tire into a constant temperature oven and cure at 80℃ for 2h to form a Shore A90 puncture-resistant coating with a thickness of 1.5mm. (3) Leakage-proof self-healing coating application: After the anti-puncture coating has cured and cooled to room temperature, pour the mixed and degassed leakage-proof self-healing coating material into the coating equipment, adjust the scraper gap to 2.2mm, and apply it evenly to the surface of the anti-puncture coating; after coating, place it in a constant temperature oven and cure it at 70℃ for 1.5h to form a self-healing gel coating layer with a thickness of 2.2mm. (4) Noise reduction and sound insulation coating: After the intermediate coating has cured and cooled to room temperature, pour the mixed and degassed noise reduction and sound insulation coating material into the coating equipment, adjust the scraper gap to 1.5mm, and coat it evenly on the surface of the intermediate coating; after coating, put it in a constant temperature oven and cure it at 60℃ for 2 hours to form a noise reduction and sound insulation coating with a thickness of 1.5mm. (5) Finished product post-treatment: After all three coating layers have cured, remove the tire and allow it to cool naturally to room temperature. Check the coating surface for bubbles, cracks, or peeling. This indicates that the tire is a finished self-healing tire. Example 2

[0022] Puncture-resistant coating: 11 parts chain extender, prepolymerization reaction temperature 80℃, stirring time 2h, NCO content 10.5%; coating thickness 1mm, curing temperature 75℃, curing time 1.5h; other raw materials, preparation steps and coating process are the same as in Example 1; Leak-proof self-healing coating: Component A: Component B = 100:14, coating thickness 2mm, curing temperature 65℃, curing time 1.2h; the rest is the same as in Example 1; Noise reduction and sound insulation coating: Component A: Component B = 100:17, coating thickness 1mm, curing temperature 55℃, curing time 1.5h; the rest is the same as in Example 1. Example 3

[0023] Puncture-resistant coating: 15 parts chain extender, prepolymerization reaction temperature 90℃, stirring time 3h, NCO content 11.5%; coating thickness 2mm, curing temperature 85℃, curing time 2.5h; other raw materials, preparation steps and coating process are the same as in Example 1; Leak-proof self-healing coating: Component A: Component B = 100:17, coating thickness 2.5mm, curing temperature 75℃, curing time 1.8h; the rest is the same as in Example 1; Noise reduction and sound insulation coating: Component A: Component B = 100:19, coating thickness 2mm, curing temperature 65℃, curing time 2.5h; the rest is the same as in Example 1.

[0024] The self-healing tire inner sealant prepared in Examples 1-3 and the finished tires were subjected to performance testing. High and low temperature resistance testing was conducted according to GB / T 1690-2010; puncture repair leakage testing was conducted according to HG / T 4383-2012; accelerated aging life was equivalently calculated according to Method B of GB / T 3512-2014. The experimental results are shown in Table 1. Table 1. Performance of self-healing tire inner coating sealant prepared in Examples 1-3

[0025] Test results show that the self-healing tire inner coating sealant prepared by this invention has stable performance over a wide temperature range, and its self-healing effect, sealing performance and service life far exceed those of existing products, meeting the sealing and protection requirements of various motor vehicle tires.

[0026] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A self-healing tire inner sealant, characterized in that, It adopts a three-layer composite coating structure, which consists of a puncture-resistant coating, a leak-proof self-healing coating, and a noise-reducing and sound-insulating coating, from the inner wall of the tire to the inner side of the tire. The puncture-resistant coating comprises the following components by mass fraction: 550-760 parts of polyester polyol I, 180-230 parts of polyester polyol II, 180-230 parts of diisocyanate, and 11-15 parts of chain extender; wherein the molecular weight of polyester polyol I and polyester polyol II is 800-2200, the diisocyanate is selected from one or more of MDI, TDI, PPDI, IPDI, and XDI, and the chain extender is an amine chain extender; The leak-proof self-healing coating is a two-component system. Component A contains 450-550 parts of polyether polyol I, 450-550 parts of polyether polyol II, 1-5 parts of catalyst, and 1-5 parts of antioxidant. Component B contains 210-300 parts of polyether polyol I, 210-300 parts of polyether polyol II, 450-550 parts of diisocyanate, and 1-5 parts of catalyst. The polyether polyols are bifunctional and / or trifunctional, with a molecular weight of 1000-5000. The noise reduction and sound insulation coating is a two-component system. Component A contains 260-330 parts of polyether polyol I, 120-180 parts of polyether polyol II, 120-180 parts of polyether polyol III, 350-450 parts of plasticizer, 1-5 parts of catalyst, and 1-5 parts of antioxidant. Component B contains 160-230 parts of polyether polyol I, 160-230 parts of polyether polyol II, 90-120 parts of diisocyanate I, 90-120 parts of diisocyanate II, 1-5 parts of catalyst, and 350-450 parts of plasticizer. The polyether polyols have bifunctional molecular weights of 2000-6000.

2. The self-healing tire inner sealant according to claim 1, characterized in that, The mass ratio of raw materials for each layer is as follows: Puncture-resistant coating: 600 parts polyester polyol I, 200 parts polyester polyol II, 200 parts diisocyanate, and 11-15 parts chain extender; Leak-proof self-healing coating: Component A: 500 parts polyether polyol I, 500 parts polyether polyol II, 1-5 parts catalyst, 1-5 parts antioxidant; Component B: 250 parts polyether polyol I, 250 parts polyether polyol II, 500 parts diisocyanate, 1-5 parts catalyst. Noise reduction and sound insulation coating component A: 300 parts of polyether polyol I, 150 parts of polyether polyol II, 150 parts of polyether polyol III, 400 parts of plasticizer, 1-5 parts of catalyst, and 1-5 parts of antioxidant; Component B: 200 parts of polyether polyol I, 200 parts of polyether polyol II, 100 parts of diisocyanate I, 100 parts of diisocyanate II, 1-5 parts of catalyst, and 400 parts of plasticizer.

3. The self-healing tire inner sealant according to claim 1, characterized in that: The puncture-resistant coating uses polyester polyol I, which is CMA-1044 polyester polyol produced by Huada Chemical Group, and polyester polyol II, which is CMA-44 polyester polyol produced by Huada Chemical Group.

4. The self-healing tire inner sealant according to claim 1, characterized in that: The antioxidants in the noise-reducing and sound-insulating coatings and the leak-proof self-healing coatings are phosphite antioxidants; the catalysts in the noise-reducing and sound-insulating coatings and the leak-proof self-healing coatings are tertiary amine polyurethane catalysts; and the plasticizers in the noise-reducing and sound-insulating coatings are DOP or DBP.

5. The self-healing tire inner coating sealant according to claim 1, characterized in that: The puncture-resistant coating has a Shore A90 hardness and a coating thickness of 1-2 mm; the leak-proof self-healing coating has a coating thickness of 2-2.5 mm; and the noise-reducing and sound-insulating coating has a coating thickness of 1-2 mm.

6. A method for preparing a self-healing tire inner coating sealant as described in any one of claims 1-5, characterized in that, Includes the following steps: Preparation of puncture-resistant coating: Polyester polyol I and polyester polyol II are heated to 45°C under nitrogen protection, diisocyanate is added and then the temperature is raised to 80-90°C. The mixture is stirred for 2-3 hours. When the NCO content of the system reaches 10.5-11.5%, a chain extender is added and stirred. Vacuum degassing is performed to obtain the puncture-resistant coating material. Preparation of leak-proof self-healing coating: Polyether polyol I and polyether polyol II in component B are vacuum dehydrated for 1.5-2 hours, heated to 45°C under nitrogen protection, diisocyanate and catalyst are added, and then heated to 80-90°C and stirred for 2-3 hours. When the NCO content of the system reaches 10.5-12%, a prepolymer is obtained. Component A is mixed completely, heated to 50-70°C and stirred for 1-2 hours to obtain the chain-extended modified component. The prepolymer and the chain-extended modified component are mixed in proportion and stirred evenly, and then vacuum degassed to obtain the leak-proof self-healing coating material. Preparation of noise reduction and sound insulation coating: Polyether polyol I and polyether polyol II in component B are vacuum dehydrated for 1.5-2 hours, heated to 45°C under nitrogen protection, diisocyanate I and diisocyanate II, catalyst and plasticizer are added, and the mixture is heated to 80-90°C and stirred for 2-3 hours. When the NCO content of the system reaches 8.5-9.5%, the prepolymer is obtained. Component A is mixed completely, heated to 40-60°C and stirred for 1-2 hours to obtain the chain extension modified component. The prepolymer and the chain extension modified component are mixed in proportion and stirred evenly, and vacuum degassing is performed to obtain the noise reduction and sound insulation coating material.

7. The preparation method according to claim 6, characterized in that, The mixing ratio of components A and B in the leak-proof self-healing coating is 100:14-17, and the mixing ratio of components A and B in the noise reduction and sound insulation coating is 100:17-19.

8. The preparation method according to claim 6, characterized in that, The catalyst is added at a rate of 0.1-0.5% of the total mass of the raw materials for each layer of rubber compound.

9. A self-healing tire, characterized in that: The inner wall of the tire is sequentially coated with the anti-puncture coating, the anti-leakage self-healing coating, and the noise reduction and sound insulation coating as described in any one of claims 1-5, and the coating process adopts the method described in any one of claims 6-8.

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