Preparation method of self-healing non-vulcanized butyl sealant and application of self-healing non-vulcanized butyl sealant in tires

Abstract

The invention relates to the technical field of sealants, in particular to a preparation method of a self-healing non-vulcanized butyl sealant and application of the self-healing non-vulcanized butyl sealant in tires. The sealant is prepared from the following raw materials in parts by weight: 10-30 parts of butyl rubber, 20-40 parts of polyisobutene, 10-30 parts of styrene-isoprene-styrene, 5-30 parts of poly-alpha olefin, 5-15 parts of petroleum resin, 1-5 parts of an antioxidant, 1-5 parts of a coloring agent and 10-20 parts of rubber filling oil, and is prepared by the following steps: weighing the butyl rubber and other materials, mixing and stirring; adding part of polyisobutene, stirring uniformly, and then adding the rest polyisobutene and poly alpha olefin to be uniform; and adding the rubber filling oil, uniformly stirring, vacuumizing until the pressure is greater than or equal to 0.08 MPa, and discharging. The sealant prepared by the invention can still be normally used at low temperature and high temperature, a tire can have enough adhesive force to resist the centrifugal force of rotation of the tire during high-speed driving, meanwhile, a pricking nail does not leak air, normal driving of an automobile is maintained, and after the nail is pulled out, the sealant rapidly fills a gap of the pricking nail and does not leak air continuously.

Description

Technical Field

[0001] The present application relates to the technical field of sealants, and in particular to a preparation method of a self-healing non-sulfurized butyl sealant and its application in tires. Background Art

[0002] With the continuous improvement of productivity, cars have changed from a luxury item to a popular means of transportation that is now found in thousands of households. Tires, as key components for automobiles, are composed of treads, steel belt layers, steel carcass cord fabrics, airtight layers and tire rims, and they undertake indispensable support and driving duties. However, their soft rubber material can easily cause a sudden drop in internal air pressure or even tire bursts when punctured by sharp objects such as nails, posing a serious threat to the lives of drivers and passengers.

[0003] In order to deal with the problem of pressure loss after a tire is punctured, the industry often adds self-repairing sealants to the airtight layer to ensure that the tire can maintain a certain internal pressure after being damaged. Chinese invention patent CN113502135A introduces a self-repairing rubber composition for tires, which includes multiple ingredients such as reverse vulcanized rubber prepolymer, liquid isoprene rubber, and silica-gel-catalytic repair polymerizer double-shell microspheres. Among them, the double-shell microspheres can break and release catalysts when the tire is punctured, thereby promoting the healing of the puncture. However, this solution is a two-component reactive sealant system. If the tire is punctured multiple times at the same position, self-repair cannot be achieved.

[0004] In addition, extreme high temperatures have occurred frequently in summer in recent years, and traditional self-repairing sealants tend to soften and flow under high temperatures; in the low temperature environment of high-latitude areas, sealants tend to harden, causing air leakage after the tire is punctured. At the same time, low temperatures will also reduce the adhesion of the colloid, causing low-temperature embrittlement problems, which not only weakens the self-repair ability of the tire, but may also destroy the power balance and bring driving safety hazards. Summary of the invention

[0005] The purpose of the present application is to overcome the shortcomings of existing tire sealants, thereby providing a self-healing non-vulcanized butyl sealant for tires, so that the sealant can still maintain normal use at low and high temperatures, and ultimately the sealant has sufficient adhesion to resist the centrifugal force of tire rotation when the tire is running at high speed, and at the same time, there is no leakage when the nail is punctured, thereby maintaining the normal driving of the car. After the nail is pulled out, the sealant quickly fills the nail gap to reduce the possibility of leakage.

[0006] In the first aspect, the present application provides a self-healing non-vulcanized butyl sealant using the following technical solution: A self-healing non-sulfurized butyl sealant, wherein the raw materials for preparing the sealant include the following components in parts by weight: Butyl rubber 10-30 parts Polyisobutylene 20-40 parts Styrene-isoprene-styrene 10-30 parts Polyalphaolefin 5-30 parts Petroleum resin 5-15 parts 1-5 parts of antioxidant Colorant 1-5 parts Rubber filler oil 10-20 parts.

[0007] Further, optionally, the sealant preparation raw materials include the following components in parts by weight: Butyl rubber 15 parts 25 parts of polyisobutylene Styrene-isoprene-styrene 25 parts Polyalphaolefin 15 parts 5 parts of petroleum resin 1 part antioxidant 2 parts colorant 12 parts of rubber filler oil.

[0008] By adopting the above technical solution: the sealant can maintain normal performance in both low and high temperature environments, which is mainly due to the characteristics of raw materials such as butyl rubber and polyisobutylene, which can maintain good elasticity and viscosity under different temperature conditions, thereby ensuring the stability and reliability of the sealant under various climatic conditions; The butyl rubber and styrene-isoprene-styrene (SIS) components in the formula have good self-healing properties. When the tire is damaged by nails, these components can quickly respond and fill the nail gap to reduce the possibility of air leakage. This self-healing ability can significantly improve the safety and service life of the tire; In addition, the formula of this self-healing non-vulcanized butyl sealant is able to maintain sufficient adhesion to resist the centrifugal force generated by the rotation of the tire when driving at high speeds through careful selection of raw materials and their proportions. This ensures the stability and safety of the tire during high-speed driving and avoids air leakage problems caused by sealant shedding or failure.

[0009] Further, optionally, the molecular weight of the polyisoolefin is one or more of 1300, 2400, and 50000.

[0010] Further, optionally, the antioxidant is one or more of an aromatic amine antioxidant, a hindered phenol antioxidant, and an auxiliary antioxidant.

[0011] Further, optionally, the colorant is pigment carbon black, and the rubber filler oil is cyclohexane oil.

[0012] In the second aspect, the present application provides a method for preparing a self-healing non-sulfurized butyl sealant using the following technical scheme: A method for preparing a self-healing non-sulfurized butyl sealant comprises the following steps: S1. Weigh butyl rubber, styrene-isoprene-styrene, antioxidant, colorant and petroleum resin according to the predetermined amount, mix and stir, then continue to add part of polyisobutylene and stir until the rubber material is uniform and free of particles, then add the remaining polyisobutylene and polyalphaolefin until the rubber material is uniform and free of particles; S2. Then continue to add rubber filling oil and stir until it is uniform and free of lumps. Finally, evacuate the system and discharge the material after the pressure is ≥0.08MPa.

[0013] Further, optionally, step S1 is specifically as follows: butyl rubber, styrene-isoprene-styrene, antioxidant, colorant and petroleum resin are weighed according to a predetermined amount, mixed and stirred for 10-30 minutes, and then 40% of polyisobutylene is added and stirred for 10-25 minutes, and after stirring until the mixture is uniform and free of particles, the remaining polyisobutylene and polyalphaolefin are added until the rubber material is uniform and free of particles.

[0014] By adopting the above technical solution: adding polyisobutylene in stages and controlling the stirring time of each stage, the sufficient mixing and uniform dispersion of the raw materials are ensured. This refined operation process helps to improve the uniformity and stability of the sealant, thereby improving its overall performance. The preparation method has clear steps, simple operation, and is easy to realize industrial production.

[0015] In the third aspect, the application of a self-healing non-sulfurized butyl sealant provided in the present application adopts the following technical scheme: the application of the above-mentioned self-healing non-sulfurized butyl sealant or the self-healing non-sulfurized butyl sealant prepared by the preparation method of the above-mentioned self-healing non-sulfurized butyl sealant in self-repairing tires.

[0016] In summary, this application has the following beneficial effects: 1. The present application uses poly-alpha olefin, polyisobutylene and liquid C5 petroleum resin in combination, so that the sealant prepared has better flexibility under low temperature conditions, the bonding performance will not decrease, and it will not become brittle. It can still be used normally under -25°C environment. In addition, the addition of butyl rubber and styrene-isoprene-styrene also greatly improves the heat resistance of the sealant, solving the problem of colloid flowing at high temperature; 2. When the sealant prepared in the present application is used in self-repairing tires, the tires can have sufficient adhesion to resist the centrifugal force of tire rotation when running at high speeds, and at the same time, there will be no air leakage when nailed, thus maintaining the normal driving of the car. After the nails are pulled out, the sealant can quickly fill the gaps of the nails without further leakage. DETAILED DESCRIPTION

[0017] The present application is further described in detail below in conjunction with specific embodiments.

[0018] The raw materials used in this application are all commercially available materials unless otherwise specified below.

[0019] Table 1: Sources of raw material components Example 1 A self-healing non-sulfurized butyl sealant, the raw material components and amounts used in its preparation are shown in the following table: Table 2: Raw material components and their dosage (kg) Raw material components Dosage Butyl rubber 15 Polyisobutylene 25 SIS 25 Polyalphaolefin 15 Petroleum resin 5 Antioxidants 1 Colorants 2 Rubber filling oil 12 The above self-healing non-vulcanized butyl sealant is prepared by the following method: S1. Weigh butyl rubber, styrene-isoprene-styrene, antioxidant, colorant and petroleum resin according to the given amount, mix and stir for 10-30 minutes, then continue to add 40% polyisobutylene and stir for 10-25 minutes, stir until it is uniform and free of particles, then add the remaining polyisobutylene and polyalphaolefin until the rubber material is uniform and free of particles; S2, then continue to add rubber filling oil, stir until it is uniform and free of lumps, and finally evacuate the system until the pressure is ≥0.08MPa and then discharge the material; The butyl rubber is common non-halogenated butyl rubber, specifically Yanshan Petrochemical 1751; the antioxidant is selected from hindered phenol antioxidants, specifically BASF Irganox 1010; the molecular weight of the polyisoolefin is 1300, specifically Dalin PB1300.

[0020] Embodiment 2-5 A self-healing non-sulfurized butyl sealant, the only difference from Example 1 is that the amounts of each component are different, as shown in the table below.

[0021] Table 3: Raw material components and their dosage in Examples 2-5 (kg) Comparative Example 1-2 A self-healing non-vulcanized butyl sealant is different from Example 1 in that the components are used differently, petroleum resin is not used in Comparative Example 1, and butyl rubber is not used in Comparative Example 2. The specific details are shown in the table below.

[0022] Table 4: Comparative Examples 1-2 and their dosage (kg) Comparative Example 3 A self-healing non-vulcanized butyl sealant is prepared by the same method as in Example 1, except that an equal amount of polyurethane is used to replace the butyl rubber.

[0023] The sealants prepared in the above-mentioned embodiments and comparative examples were tested for their performance, and the test results are shown in the table below.

[0024] Table 4: Test results of sealant properties obtained in Examples 1-5 and Comparative Examples 1-3 From the data in Table 4 in the above table, it can be seen that the ratio of butyl rubber and polyalphaolefin is changed in Examples 2 and 3 compared with Example 1. Although Examples 2 and 3 meet the requirements of low-temperature flexibility, heat resistance and relevant requirements in GB / T 38510-2020, the annular initial adhesion is about 25% lower than that in Example 1; Compared with Example 1, Example 4 changes the ratio of polyisobutylene and SIS, and its various indicators are close to those of Example 1. However, due to the excessive content of the polyisobutylene component, displacement also occurs during the high-speed performance test; Comparative Example 1 omits the petroleum resin component and increases the amount of rubber filler oil. Other properties are satisfactory, the ring initial adhesion is lower than that of Example 1, but the low-temperature flexibility is unqualified; Comparative Example 2 omits butyl rubber and increases the amount of polyalphaolefin, but the tire pressure is lower than 90% of the initial pressure in multiple test items; Example 5 increases the amount of petroleum resin, although the ring initial adhesion is about 10% higher than that of Example 1, the heat resistance and high-speed performance both show different degrees of slippage and displacement; In addition, in Comparative Example 3, an equal amount of polyurethane was used to replace butyl rubber. In multiple test items, the tire pressure was lower than 90% of the initial pressure, and the pressure drop trend was more obvious at low temperatures. It could even reach a low value of 66% under continuous cruising, and displacement also occurred.

[0025] The above data show that: the ratio of butyl rubber and polyalphaolefin can affect the annular initial adhesion of the sealant to a small extent, but if butyl rubber is not used or other rubber matrix is ​​used, it will directly affect the sealing performance after the tire is punctured; the ratio of polyisobutylene and SIS can also affect the annular initial adhesion to a small extent, but if SIS is not used, displacement will occur during the high-speed performance test; the liquid petroleum resin component has a greater impact on the annular initial adhesion and low-temperature flexibility, but if the amount is too much, heat resistance slip and high-speed performance test displacement will also occur. In summary, the formula of the self-healing non-vulcanized butyl sealant is carefully selected through the raw materials and their ratios, so that the sealant can maintain normal performance in both low and high temperature environments, and can maintain good elasticity and viscosity under different temperature conditions, thereby ensuring the stability and reliability of the sealant under various climatic conditions; The above are all modifications without creative contribution or solutions that obviously constitute technical inspiration that can be made to the present embodiment as needed by technical personnel in this field after reading this specification, but they should be protected by patent law as long as they are within the scope of the claims of this application.

Claims

1. A self-healing non-vulcanized butyl sealant, characterized in that: The raw materials for preparing the sealant include the following components in parts by weight: Butyl rubber 10-30 parts Polyisobutylene 20-40 parts Styrene-isoprene-styrene 10-30 parts Polyalphaolefin 5-30 parts Petroleum resin 5-15 parts 1-5 parts of antioxidant Colorant 1-5 parts Rubber filler oil 10-20 parts.

2. The self-healing non-vulcanized butyl sealant according to claim 1, characterized in that: The raw materials for preparing the sealant include the following components in parts by weight: Butyl rubber 15 parts 25 parts of polyisobutylene Styrene-isoprene-styrene 25 parts Polyalphaolefin 15 parts 5 parts of petroleum resin 1 part antioxidant 2 parts colorant 12 parts of rubber filler oil.

3. The self-healing non-vulcanized butyl sealant according to claim 1 or 2, characterized in that: The molecular weight of the polyisoolefin is one or more of 1300, 2400 and 50000.

4. The self-healing non-vulcanized butyl sealant according to claim 1 or 2, characterized in that: The antioxidant is one or more of an aromatic amine antioxidant, a hindered phenol antioxidant, and an auxiliary antioxidant.

5. The self-healing non-vulcanized butyl sealant according to claim 1 or 2, characterized in that: The colorant is carbon black, and the rubber filler oil is naphthenic oil.

6. The method for preparing the self-healing non-sulfurized butyl sealant according to any one of claims 1 to 2, characterized in that: The steps include: S1. Weigh butyl rubber, styrene-isoprene-styrene, antioxidant, colorant and petroleum resin according to the predetermined amount, mix and stir, then continue to add part of polyisobutylene and stir until the rubber material is uniform and free of particles, then add the remaining polyisobutylene and polyalphaolefin until the rubber material is uniform and free of particles; S2. Then continue to add rubber filling oil and stir until it is uniform and free of lumps. Finally, evacuate the system and discharge the material after the pressure is ≥0.08MPa.

7. The method for preparing the self-healing non-sulfurized butyl sealant according to claim 6, characterized in that: Step S1 is specifically as follows: butyl rubber, styrene-isoprene-styrene, antioxidant, colorant and petroleum resin are weighed according to a predetermined amount, mixed and stirred for 10-30 minutes, and then 40% of polyisobutylene is added and stirred for 10-25 minutes. After stirring until the mixture is uniform and free of particles, the remaining polyisobutylene and polyalphaolefin are added until the rubber material is uniform and free of particles.

8. Use of the self-healing non-sulfurized butyl sealant according to claim 1 or 2 and / or the self-healing non-sulfurized butyl sealant prepared by the preparation method of the self-healing non-sulfurized butyl sealant according to any one of claims 6 to 7 in self-repairing tires.

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