High-heat-resistance long-service-life rubber composition for curing bladder and preparation method thereof

Abstract

The invention provides a high-heat-resistance long-service-life rubber composition for a curing bladder and a preparation method thereof. The invention relates to a high-heat-resistance long-life rubber composition for a curing bladder. The high-heat-resistance long-life rubber composition comprises the following components in parts by weight: 90-100 parts of butyl rubber; 3-10 parts of low unsaturation butyl rubber; 40 to 70 parts of reinforcing filler; 3-10 parts of a phenolic resin vulcanizing agent; 2-8 parts of an active agent; and 1-10 parts of functionalized liquid butyl rubber. The functional liquid butyl rubber with active functional groups is used for replacing traditional castor oil to prepare the rubber composition for the curing capsule, and the prepared rubber composition has excellent heat resistance and long flex life.

Description

Technical Field

[0001] This invention relates to a high-performance rubber material for tire vulcanization processes, specifically to a high-heat-resistant, long-life vulcanizing bladder rubber composition and its preparation method, belonging to the field of rubber production technology. Background Technology

[0002] In the manufacturing process of pneumatic tires, vulcanization is a crucial step that determines the final performance of the tire. The vulcanizing bladder, as a core component of the vulcanizing machine, operates under harsh conditions of high temperature, high pressure, and repeated expansion and contraction. As the inner core of the mold, it supports the green tire blank from the inside, ensuring it fits tightly against the tread pattern of the outer mold, and completes the vulcanization and shaping of the tire under the action of a heat medium. Therefore, the vulcanizing bladder must possess excellent heat aging resistance, flexural fatigue resistance, low permanent deformation, and good thermal conductivity. Currently, the mainstream base material for vulcanizing bladders in industry is butyl rubber (IIR), especially resin-vulcanized butyl rubber systems. However, to ensure the flexibility of the bladder during repeated expansion and contraction and to reduce the Mooney viscosity of the rubber compound for easier processing, traditional bladder formulations must include a softener (plasticizer). For a long time, castor oil, due to its wide availability and certain plasticizing effect on butyl rubber, has become the standard softener in the industry.

[0003] However, castor oil is a physical plasticizer, prone to migration and extraction. Castor oil molecules are not chemically bonded to the butyl rubber matrix; they are physically mixed only by intermolecular forces. At the high operating temperatures of 170-190°C in vulcanized bladders, accompanied by hundreds of high-ratio stretching and shrinking cycles, small-molecule castor oil easily migrates from the rubber network to the bladder surface. This not only causes the bladder body to gradually harden and lose elasticity, leading to premature cracking and shortening its lifespan, but the migrated castor oil can also contaminate the tire's inner wall or form carbon deposits on the bladder surface, affecting the tire's dynamic balance and appearance.

[0004] Secondly, although castor oil has relatively good heat resistance compared to other vegetable oils, it can still undergo oxidation, decomposition, or polymerization reactions under long-term high-temperature and aerobic conditions. Its decomposition products are often acidic, which can accelerate the degradation of the butyl rubber backbone, causing the capsule to become soft and sticky, increasing the difficulty of demolding, and even causing the capsule to stick to the inside of the tire, resulting in serious production accidents.

[0005] Furthermore, traditional butyl rubber capsule formulations typically use a large amount of carbon black to improve thermal conductivity and provide reinforcement. Castor oil, as a polar molecule, does not have perfect compatibility with the non-polar surfaces of butyl rubber and carbon black. During the mixing process, uneven dispersion can easily create microscopic stress concentration points. These microscopic defects can rapidly expand into macroscopic cracks under repeated flexing, leading to sudden capsule rupture.

[0006] Existing technologies have attempted to use paraffin oil or aromatic oil to replace castor oil, but these mineral oils have poorer compatibility with the resin vulcanization system and interfere with the crosslinking reaction of the resin on butyl rubber, resulting in slower vulcanization speed and reduced crosslinking density. Other technologies have attempted to use low molecular weight polyisobutylene as a plasticizer, which solves the compatibility problem, but due to the lack of active functional groups, it remains a physical filler and cannot solve the problems of migration at high temperatures and contribution to modulus. Summary of the Invention

[0007] Based on the above background, the purpose of this invention is to provide a rubber composition for high heat resistance and long life vulcanized capsules and its preparation method, thereby solving the technical problems in the prior art such as easy migration and extraction, poor heat aging resistance, short service life, and easy contamination of tires caused by the use of physical plasticizers such as castor oil in vulcanized capsules.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0009] A rubber composition for high heat resistance and long life vulcanized capsules comprises the following components in parts by weight:

[0010] 90-100 parts of butyl rubber;

[0011] 3-10 parts of low-unsaturation butyl rubber;

[0012] 40-70 parts of reinforcing filler;

[0013] 3-10 parts of phenolic resin vulcanizing agent;

[0014] Surfactant 2-8 parts; and,

[0015] Functionalized liquid butyl rubber 1-10 parts.

[0016] Preferably, the functionalized liquid butyl rubber is a liquid butyl rubber with phenolic hydroxyl groups, maleic anhydride or benzyl halogen functional groups grafted onto its molecular chain; the functional group content of the functionalized liquid butyl rubber is 0.05-0.5 mol / 100g, and its number average molecular weight Mn is 8000-15000.

[0017] Preferably, the functionalized liquid butyl rubber is prepared by a solution grafting method, which includes the following steps:

[0018] The base liquid butyl rubber is dissolved in a non-polar solvent to form a glue solution;

[0019] Under nitrogen protection, grafting monomers and initiators are added to the adhesive solution, and the grafting reaction is carried out at a temperature of 80-120°C.

[0020] After the grafting reaction is completed, unreacted monomers and solvents are removed by precipitation, washing and drying to obtain functionalized liquid butyl rubber;

[0021] The grafting monomer is selected from maleic anhydride, p-hydroxystyrene, or p-chloromethylstyrene.

[0022] Preferably, the initiator is benzoyl peroxide or azobisisobutyronitrile, and the amount of the initiator added is 0.5-2.0% of the mass of the base liquid butyl rubber; the gel content of the functionalized liquid butyl rubber prepared by the solution grafting method is less than 0.1%.

[0023] Preferably, the activator includes zinc oxide and magnesium oxide, and the mass ratio of magnesium oxide to zinc oxide is 1:2-4; the magnesium oxide is capable of forming ionic bonds with the functional groups on the molecular chain of the functionalized liquid butyl rubber.

[0024] Preferably, the reinforcing filler comprises carbon black.

[0025] The present invention also provides a method for preparing the above-mentioned high heat-resistant and long-life vulcanized capsule rubber composition, the method comprising the following steps:

[0026] S1. First stage mixing: Add 90-100 parts by weight of butyl rubber, 3-10 parts by weight of low-unsaturated butyl rubber, 40-70 parts by weight of reinforcing filler, and 2-8 parts by weight of activator to a mixer and mix.

[0027] S2, Two-stage mixing: Add 3-10 parts by weight of phenolic resin vulcanizing agent and 1-10 parts by weight of functionalized liquid butyl rubber, mix and discharge the glue;

[0028] S3. Filtering and open milling: The rubber material after de-draining is filtered through a filter machine, and then thin-passed, triangularly wrapped, and sheeted on an open mill.

[0029] S4, vulcanization molding.

[0030] Preferably, the method further includes the following steps:

[0031] Before step S1, the functionalized liquid butyl rubber and a portion of phenolic resin vulcanizing agent are pre-mixed at 130-150°C for 3-8 minutes to obtain a pre-crosslinked plasticizing masterbatch; in step S2, the pre-crosslinked plasticizing masterbatch is used to replace the directly added functionalized liquid butyl rubber.

[0032] Preferably, in step S3, the filtration is performed at 90-110°C through a 150-200 mesh filter.

[0033] Preferably, in step S4, the vulcanization molding conditions are: vulcanization temperature 170-190℃, vulcanization time t90+10 minutes, and vulcanization pressure not less than 15MPa.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] This invention discloses a high-heat-resistant, long-life vulcanized capsule rubber composition and its preparation method. The method utilizes functionalized liquid butyl rubber with active functional groups to replace traditional castor oil in preparing the vulcanized capsule rubber composition. During vulcanization, the functionalized liquid butyl rubber is firmly grafted onto the butyl rubber matrix network through chemical bonds, achieving permanent plasticization. Because easily oxidized castor oil is eliminated, and the functionalized liquid butyl rubber itself has a saturated carbon chain skeleton, combined with the ionic bond reinforcement network formed by magnesium oxide, the vulcanized capsules prepared by this invention exhibit excellent thermal stability at high temperatures. By introducing a filtration process combined with solution grafting to prepare high-purity functionalized liquid butyl rubber, this invention effectively controls gel particles and hard impurities in the rubber compound, significantly reducing the risk of early fatigue fracture of the vulcanized capsules due to microscopic defects. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0037] Figure 1 This is a microscopic image of the surface morphology of the vulcanized capsule prepared in Example 1 of the present invention after high-temperature aging and fatigue testing;

[0038] Figure 2 This is a microscopic image of the surface morphology of the vulcanized capsule prepared in Comparative Example 4 of this invention after high-temperature aging and fatigue testing. Detailed Implementation

[0039] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any modifications and / or alterations made to the present invention will fall within the protection scope of the present invention.

[0040] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art. Unless otherwise specified, the components or equipment in the following embodiments are general standard parts or components known to those skilled in the art, and their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0041] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In this detailed description, numerous specific details are set forth to facilitate explanation and provide a thorough understanding of the embodiments of the present invention. However, one or more embodiments may be practiced by those skilled in the art without these specific details.

[0042] I. Specifications of main raw materials:

[0043] Butyl rubber (IIR): Unsaturation degree approximately 1.7 mol%

[0044] Low-unsaturation butyl rubber: unsaturation controlled at 0.5-0.8 mol%, Mooney viscosity ML(1+8) 45 at 125℃;

[0045] Basic liquid butyl rubber: with a number average molecular weight (Mn) of approximately 10,000, serving as a basic raw material for functional modification;

[0046] Reinforcing filler: Carbon black N330;

[0047] Phenolic resin vulcanizing agent: Octylphenol resin;

[0048] Activators: Indirect zinc oxide, purity 99.7%; Highly active magnesium oxide, iodine uptake value 120 mg / g;

[0049] Grafting monomers: maleic anhydride (MAH), p-hydroxystyrene, and p-chloromethylstyrene, all of which were chemically pure;

[0050] Initiators: benzoyl peroxide (BPO), azobisisobutyronitrile (AIBN).

[0051] II. Preparation of Functionalized Liquid Butyl Rubber

[0052] The core of this invention lies in the use of liquid butyl rubber with specific functional groups. The following are preparation methods of several liquid butyl rubbers modified with different functional groups.

[0053] Synthesis Example 1: Maleic anhydride-grafted liquid butyl rubber (L-IIR-g-MAH)

[0054] 100g of base liquid butyl rubber was dissolved in 500mL of toluene to form a glue solution, which was then placed in a reaction vessel equipped with a stirrer and a condenser.

[0055] Nitrogen gas was introduced for protection, and the temperature was raised to 110℃;

[0056] Dissolve 5g of maleic anhydride (grafted monomer) and 1.0g of benzoyl peroxide (initiator) in a small amount of toluene and slowly add the solution dropwise into the reaction vessel.

[0057] Maintain the reaction temperature at 110℃ for 4 hours;

[0058] After the reaction was complete, the gel was poured into excess acetone to precipitate, washed three times to remove unreacted monomers, and then dried under vacuum.

[0059] Test results: The number-average molecular weight (Mn) of the obtained product was 11500, the grafting rate was 0.35 mol / 100g, and the gel content was <0.05%.

[0060] Synthesis Example 2: Phenolic hydroxyl-grafted liquid butyl rubber (L-IIR-g-OH)

[0061] The steps are the same as in Example 1, except that:

[0062] The grafting monomer was replaced with p-hydroxystyrene, the initiator was azobisisobutyronitrile, and the reaction temperature was set to 90℃.

[0063] The test results showed that the number-average molecular weight (Mn) of the obtained product was 12000, and the content of phenolic hydroxyl functional groups was 0.28 mol / 100g.

[0064] Synthesis Example 3: Benzyl halide-grafted liquid butyl rubber (L-IIR-g-Cl)

[0065] The steps are the same as in Example 1, except that:

[0066] The grafting monomer was replaced with p-chloromethylstyrene, and the reaction temperature was set to 100℃.

[0067] Detection results: The number-average molecular weight (Mn) of the obtained product was 13500, and the content of benzyl chloride functional groups was 0.40 mol / 100g.

[0068] III. Preparation of Rubber Compositions

[0069] The preparation of each embodiment and comparative example was carried out according to the following process steps, wherein Example 2 also adopted a pre-crosslinking process.

[0070] S1, Stage 1 Mixing (Base Material Mixing):

[0071] In the internal mixer, set the initial temperature to 60℃ and the rotor speed to 60rpm. Add butyl rubber and low-unsaturated butyl rubber, and mix for 1 minute. Then add activators (zinc oxide and magnesium oxide) and reinforcing fillers (carbon black), and mix until 135℃ for discharge.

[0072] S2, Two-stage mixing (sulfurization and plasticization):

[0073] Return a section of the compound to the internal mixer, add phenolic resin vulcanizing agent and functionalized liquid butyl rubber (or a comparative proportion of ordinary liquid butyl rubber / castor oil).

[0074] Example 2 uses a pre-crosslinked plasticizer masterbatch in this step.

[0075] S3, Filtering and Open Mixing:

[0076] The rubber compound is filtered through a 200-mesh filter at 100°C, then passed through a two-roll mill five times, formed into triangular sheets, and then sheeted and left to stand for 8 hours.

[0077] S4, vulcanization molding:

[0078] Vulcanization conditions: 180℃×(t90+10min), pressure 16MPa.

[0079] IV. Specific Formulations of Examples and Comparative Examples

[0080] To verify the technical effect of the present invention, the formulations shown in Table 1 were designed (unit: parts by weight, phr).

[0081] Table 1. Specific Formulations of Examples and Comparative Examples

[0082]

[0083] Example 1 uses the maleic anhydride-grafted liquid butyl rubber from Synthetic Example 1, and is conventionally compounded.

[0084] Example 2 uses the maleic anhydride-grafted liquid butyl rubber of Example 1, but adopts a pre-crosslinking process (that is, in step S2, the maleic anhydride-grafted liquid butyl rubber is premixed with 2 parts of phenolic resin vulcanizing agent at 140°C for 5 minutes to make a masterbatch before being added).

[0085] Example 3 uses the phenolic hydroxyl-grafted liquid butyl rubber from Example 2.

[0086] Example 4 uses the benzyl halide-grafted liquid butyl rubber from Synthetic Example 3.

[0087] Comparative Example 1 uses unfunctionalized ordinary liquid butyl rubber.

[0088] Comparative Example 2 does not contain low-unsaturation butyl rubber; it is entirely composed of ordinary butyl rubber.

[0089] Comparative Example 3 did not contain magnesium oxide, but only zinc oxide, which disrupted the ionic bonding conditions.

[0090] Comparative Example 4 uses castor oil instead of functionalized liquid butyl rubber, which is a common softener solution in the current vulcanized capsule industry.

[0091] V. Performance Test Results and Analysis

[0092] After vulcanizing the rubber compounds of Examples 1-4 and Comparative Examples 1-4, their physical and mechanical properties and aging properties were tested (aging conditions were 180℃ × 72 hours), and the results are shown in Table 2.

[0093] Table 2 Comparison of performance test results between Examples 1-4 and Comparative Examples 1-4

[0094]

[0095] Comparing Example 1 and Comparative Example 4, it can be seen that Comparative Example 4 has a better initial softening effect and lower hardness, but its tensile stress and tensile strength are both lower than those of Example 1. This indicates that although the small-molecule castor oil softens the rubber compound, it also weakens the cross-linking network. After aging at 180°C, the performance of Comparative Example 4 drops sharply, with a surge in hardness, a change in tensile strength of up to +72%, and a flexural life that drops from 32,000 cycles to 8,000 cycles, with a life retention rate of only 25%. This is because castor oil is a small-molecule ester compound, which is prone to migration, volatilization, or extraction under the high-temperature vulcanization and use environment of 180°C. Once the castor oil is lost, micropores are left inside the rubber, leading to stress concentration and loss of plasticizing effect, causing the rubber compound to harden and become brittle rapidly. In contrast, the functionalized liquid butyl rubber of Example 1 has a macromolecular structure and is chemically or ionicly bonded to magnesium oxide / zinc oxide and the resin system through side chain functional groups. This anchoring effect prevents the plasticizer from migrating at high temperatures, thus ensuring the performance stability of the capsule after long-term high-temperature use.

[0096] Comparing Example 1 and Comparative Example 1, it can be seen that after using functionalized liquid butyl rubber grafted with maleic anhydride, the rate of change of tensile stress after aging is significantly reduced, and the flexural life retention rate after aging is greatly improved. The ordinary liquid rubber in Comparative Example 1 only acts as a physical plasticizer and is easily migrated or extracted at high temperatures. In contrast, the functionalized liquid rubber in Example 1 forms ionic bonds with the magnesium oxide / zinc oxide system through the anhydride groups on its side chains, and even participates in the crosslinking network of the resin, thereby being anchored in the rubber matrix, achieving long-lasting plasticization and anti-aging properties.

[0097] Comparing Example 1 and Comparative Example 2, it can be seen that Comparative Example 2, which removed the low-unsaturation butyl rubber, although its initial performance was acceptable, had a significantly lower lifespan retention rate after aging than Example 1. This indicates that the addition of a small amount of low-unsaturation component effectively blocked the oxidative chain reaction during the aging process and improved heat resistance.

[0098] Comparing Example 1 and Comparative Example 3, it can be seen that Comparative Example 3, which removed magnesium oxide and used only zinc oxide, showed a larger change in elongation after aging and a decreased lifespan retention rate. Magnesium oxide not only acts as an acid scavenger, but more importantly, its Mg content... 2+ Ions can form stable ionic bonds with carboxyl or phenolic hydroxyl groups on functionalized liquid rubber. These ionic bonds are thermally reversible and can provide additional physical crosslinking points at high temperatures, restricting molecular chain slippage and thus inhibiting deformation and hardness increase.

[0099] Comparing Example 2 and Example 1, it can be seen that Example 2 adopted a pre-crosslinked plasticizing masterbatch process. The results show that Example 2 had the best flexural life among all examples. Pre-mixing the functionalized liquid rubber with a small amount of resin at high temperature allows the liquid rubber molecular chains to undergo partial branching or chain extension reactions and be better dispersed. In subsequent mixing, this microgel-like plasticizing phase can more effectively dissipate stress, thereby significantly improving fatigue resistance.

[0100] To further and more intuitively verify the anti-aging mechanism of the present invention, the samples of Example 1 and Comparative Example 4 were aged at 180°C for 72 hours and subjected to 30,000 flexural fatigue tests. Their surface morphology was then observed and compared using an optical microscope. The results are as follows: Figure 1 and Figure 2 As shown.

[0101] from Figure 1 As can be seen, despite undergoing rigorous high-temperature aging and fatigue testing, the surface of the sample in Example 1 remained relatively dense and smooth, with only a small number of micropores and no obvious macroscopic cracks. This indicates that the pre-crosslinked functionalized liquid butyl rubber used in this invention was successfully anchored in the rubber matrix, did not migrate at high temperatures, and continued to play a plasticizing and toughening role, allowing the rubber compound to retain sufficient elasticity to resist flexural stress after aging.

[0102] from Figure 2 As can be seen, the sample surface of Comparative Example 4 exhibits numerous deep and wide cracks, displaying a severe mud-crack-like failure morphology, which is typical of thermo-oxidative aging and stress cracking. This is because the castor oil used in Comparative Example 4 undergoes significant volatilization and extraction at high temperatures, leading to shrinkage of the rubber compound, a sharp increase in hardness, and loss of elasticity. The brittle surface cannot withstand repeated flexural deformation, ultimately resulting in severe surface cracking. Such cracks will rapidly propagate in actual use, causing the capsule to leak or rupture, thus greatly shortening its service life.

[0103] In summary, this invention introduces functionalized liquid butyl rubber to replace traditional castor oil and ordinary liquid rubber, and combines it with a specific low-unsaturation butyl rubber and activator system to successfully prepare a rubber composition with excellent heat resistance and long flexural life. This solves the problem of early hardening and cracking of capsules caused by easy migration of plasticizers in the prior art, and significantly extends the service life of vulcanized capsules.

[0104] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A rubber composition for high heat resistance and long lifespan vulcanized capsules, characterized in that: This high heat-resistant, long-life vulcanized capsule rubber composition comprises the following components in parts by weight: 90-100 parts of butyl rubber; 3-10 parts of low-unsaturation butyl rubber; 40-70 parts of reinforcing filler; 3-10 parts of phenolic resin vulcanizing agent; Surfactant 2-8 parts; and, Functionalized liquid butyl rubber 1-10 parts.

2. The rubber composition for high heat resistance and long life vulcanized capsules according to claim 1, characterized in that: The functionalized liquid butyl rubber is a liquid butyl rubber with phenolic hydroxyl groups, maleic anhydride or benzyl halogen functional groups grafted onto its molecular chain; the functional group content of the functionalized liquid butyl rubber is 0.05-0.5 mol / 100g, and its number average molecular weight Mn is 8000-15000.

3. The rubber composition for high heat resistance and long life vulcanized capsules according to claim 2, characterized in that: The functionalized liquid butyl rubber was prepared by a solution grafting method, which includes the following steps: The base liquid butyl rubber is dissolved in a non-polar solvent to form a glue solution; Under nitrogen protection, grafting monomers and initiators are added to the adhesive solution, and the grafting reaction is carried out at a temperature of 80-120°C. After the grafting reaction is completed, unreacted monomers and solvents are removed by precipitation, washing and drying to obtain functionalized liquid butyl rubber; The grafting monomer is selected from maleic anhydride, p-hydroxystyrene, or p-chloromethylstyrene.

4. The rubber composition for high heat resistance and long life vulcanized capsules according to claim 3, characterized in that: The initiator is benzoyl peroxide or azobisisobutyronitrile, and the amount of the initiator added is 0.5-2.0% of the mass of the base liquid butyl rubber; the gel content of the functionalized liquid butyl rubber prepared by the solution grafting method is less than 0.1%.

5. The rubber composition for high heat resistance and long life vulcanized capsules according to claim 1, characterized in that: The activator includes zinc oxide and magnesium oxide, and the mass ratio of magnesium oxide to zinc oxide is 1:2-4; the magnesium oxide can form ionic bonds with the functional groups on the molecular chain of the functionalized liquid butyl rubber.

6. The rubber composition for high heat resistance and long life vulcanized capsules according to claim 1, characterized in that: The reinforcing filler includes carbon black.

7. A method for preparing a high heat-resistant, long-life vulcanized capsule rubber composition as described in any one of claims 1-6, characterized in that: The method includes the following steps: S1. First stage mixing: Add 90-100 parts by weight of butyl rubber, 3-10 parts by weight of low-unsaturated butyl rubber, 40-70 parts by weight of reinforcing filler, and 2-8 parts by weight of activator to a mixer and mix. S2, Two-stage mixing: Add 3-10 parts by weight of phenolic resin vulcanizing agent and 1-10 parts by weight of functionalized liquid butyl rubber, mix and discharge the glue; S3. Filtering and open milling: The rubber material after de-draining is filtered through a filter machine, and then thin-passed, triangularly wrapped, and sheeted on an open mill. S4, vulcanization molding.

8. The method for preparing a high heat-resistant, long-life vulcanized capsule rubber composition according to claim 7, characterized in that: The method further includes the following steps: before step S1, the functionalized liquid butyl rubber and a portion of phenolic resin vulcanizing agent are pre-mixed at 130-150°C for 3-8 minutes to obtain a pre-crosslinked plasticizing masterbatch; in step S2, the pre-crosslinked plasticizing masterbatch is used to replace the directly added functionalized liquid butyl rubber.

9. The method for preparing a high heat-resistant, long-life vulcanized capsule rubber composition according to claim 7, characterized in that: In step S3, the filtration is performed at 90-110°C through a 150-200 mesh filter.

10. The method for preparing a high heat-resistant, long-life vulcanized capsule rubber composition according to claim 7, characterized in that: In step S4, the conditions for vulcanization molding are: vulcanization temperature 170-190℃, vulcanization time t90+10 minutes, and vulcanization pressure not less than 15MPa.

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