Medicinal chlorinated butyl rubber sealing ring and preparation method thereof

Abstract

The invention relates to the technical field of rubber sealing rings, and particularly discloses a medicinal chlorinated butyl rubber sealing ring and a preparation method thereof. The medicinal chlorinated butyl rubber sealing ring is prepared from the following raw materials in parts by weight: 60-85 parts of chlorinated butyl rubber, 1-3 parts of a vulcanizing agent, 0.5-2 parts of an accelerant, 10-30 parts of a reinforcing filler, 0.5-2 parts of an anti-aging agent and 5-15 parts of a softening plasticizer, wherein the reinforcing filler is CaCO3 (at) SiO2 (at) PDA (at) G composite particles. The medicinal chlorinated butyl rubber sealing ring prepared by the invention has relatively good air tightness and mechanical properties.

Description

Technical Field

[0001] This application relates to the field of rubber sealing ring technology, and more specifically, it relates to a pharmaceutical chlorinated butyl rubber sealing ring and its preparation method. Background Technology

[0002] Pharmaceutical sealing rings are a key component of pharmaceutical packaging systems, primarily used to seal containers such as injection vials, infusion bags, and pharmaceutical bottle caps, preventing drug leakage, contamination, and the intrusion of external microorganisms. Their performance directly affects the safety, stability, and efficacy of the drug. Butyl rubber (IIR) is a commonly used material for pharmaceutical sealing rings due to its excellent airtightness, chemical stability, and aging resistance. Its molecular structure contains a small number of unsaturated double bonds, which can form a network structure through vulcanization cross-linking. However, butyl rubber suffers from drawbacks such as slow vulcanization speed, poor mutual adhesion, poor compatibility with other rubbers, and weak interaction with reinforcing agents. These shortcomings significantly limit the application of butyl rubber.

[0003] To address the shortcomings of butyl rubber, chlorinated butyl rubber was developed. As a modified product of butyl rubber, chlorinated butyl rubber retains the inherent excellent properties of butyl rubber. At room temperature, its air permeability is only 1 / 4 that of natural rubber and 1 / 9 that of styrene-butadiene rubber. In addition, chlorinated butyl rubber also has a series of advantages such as fast vulcanization speed, co-vulcanization with other rubbers, better heat resistance, and low compression set.

[0004] Patent application CN103398306A discloses a high-sealing and high-heat-dissipation LED lamp. An O-ring is provided between the lamp housing and the lamp cover. The components and weight parts of the O-ring are: 100 parts of chlorinated butyl rubber, 15-25 parts of magnesium borate, 50-85 parts of carbon black, 10-15 parts of silicon carbide, 1-3 parts of zinc oxide, and 1-5 parts of stearic acid. Due to the high price of raw rubber and the problem of unsatisfactory mechanical properties in rubber compositions, in order to reduce material costs and improve mechanical properties, it is necessary to add low-cost inorganic fillers to reduce the rubber content. However, the reduction of rubber content will have a certain impact on the airtightness of the rubber composition. Moreover, the compatibility between inorganic fillers and other raw materials in the rubber composition is not ideal, and there are problems of migration, precipitation, and agglomeration, which leads to unstable mechanical properties of the rubber composition and further deterioration of airtightness. Summary of the Invention

[0005] To improve the airtightness of chlorinated butyl rubber, this application provides a pharmaceutical chlorinated butyl rubber sealing ring and its preparation method.

[0006] In a first aspect, this application provides a pharmaceutical-grade chlorinated butyl rubber sealing ring, employing the following technical solution: A pharmaceutical-grade chlorinated butyl rubber sealing ring is made from the following raw materials in parts by weight: 60-85 parts chlorinated butyl rubber, 1-3 parts vulcanizing agent, 0.5-2 parts accelerator, 10-30 parts reinforcing filler, 0.5-2 parts antioxidant, and 5-15 parts softening plasticizer. The method for preparing the reinforcing filler includes the following steps: (1) Fill the pores of porous silica with nano-calcium carbonate to form core-shell CaCO3@SiO2 particles; (2) CaCO3@SiO2 particles were added to Tris-HCl buffer and ultrasonically dispersed. Dopamine hydrochloride was then added and stirred for 6-12 hours. The filler was obtained by filtration and washing. The filler was then added to water and ultrasonically dispersed to form a filler suspension. (3) After ultrasonically dispersing graphene in water, it is added to the filler suspension, stirred and reacted, and then centrifuged and dried to obtain CaCO3@SiO2@PDA@G composite particles; The mass ratio of dopamine hydrochloride, graphene, and CaCO3@SiO2 particles is (10-20):(2-5):100.

[0007] By adopting the above technical solution, nano-calcium carbonate is filled into the pores of porous silica to form a "hard core-elastic shell" structure. This structure utilizes the rigid support of calcium carbonate while mitigating filler agglomeration through the porous silica shell, achieving a balance between rigidity and flexibility. At the same time, polydopamine (PDA) is coated on the surface of CaCO3@SiO2 particles through self-polymerization. PDA combines with graphene through multiple interactions such as π-π stacking, hydrogen bonding, and covalent bonding to obtain CaCO3@SiO2@PDA@G composite particles.

[0008] The CaCO3@SiO2@PDA@G composite particles prepared in this application exhibit good bonding with chlorinated butyl rubber through polar group interaction, chemical bonding, and filler network, significantly improving the mechanical properties and airtightness of the rubber sealing ring.

[0009] Preferably, step (1), the method for preparing the CaCO3@SiO2 particles, includes the following steps: S1, nano-calcium carbonate is ultrasonically dispersed in deionized water to obtain a suspension; S2, the suspension is added to porous silica and vacuumed, and the CaCO3@SiO2 particles are obtained by negative pressure adsorption for 1-3 hours. The mass ratio of the nano-calcium carbonate to the porous silica is 1:(3-7).

[0010] By employing the above technical solution, air or moisture is often present in the pores of porous silica. A negative pressure environment, by reducing air pressure, allows the gas within the pores to escape, creating a local vacuum, thus providing the impetus for the permeation of the nano-calcium carbonate suspension. Simultaneously, under negative pressure conditions, the nano-calcium carbonate suspension can enter the pores of porous silica more efficiently through the pressure difference, fixing the particles through physical adsorption (such as van der Waals forces) or chemical reactions (such as hydrogen bonding between the hydroxyl groups on the calcium carbonate surface and the silanol groups of porous silica). Since porous silica is relatively expensive, filling the pores of porous silica with nano-calcium carbonate not only replaces porous silica as a reinforcing filler for rubber but also offers economic benefits.

[0011] Preferably, the porous silica is a mixture of mesoporous silica and macroporous silica in a mass ratio of (5-7):(3-5).

[0012] By adopting the above technical solution, the combined use of mesoporous silica and macroporous silica can not only meet the filling requirements of nano-calcium carbonate with different particle sizes and improve the filling rate of nano-calcium carbonate, thereby improving the reinforcing effect of the prepared CaCO3@SiO2 particles on the rubber matrix; moreover, mesoporous silica has a high specific surface area and can be tightly bonded to the chlorinated butyl rubber molecular chains through a hydrogen bond network, thereby improving the tensile strength of the sealing ring. At the same time, the large pores of macroporous silica can enable the rubber molecular chains to cross-link and form a mechanical spring structure with strong stress dispersion ability, which can reduce the risk of cracking of the sealing ring. This application, by filling nano-calcium carbonate with different particle sizes into matching mesoporous silica and macroporous silica, can not only improve the reinforcing effect of CaCO3@SiO2 particles on the rubber matrix, but also enable the rubber sealing ring to have high tensile strength and tear resistance.

[0013] Preferably, the method for preparing the macroporous silica includes the following steps: The carbohydrate compound was dissolved in water, ultrasonically dispersed, and then silica sol was added and stirred evenly to obtain a mixture. The mixture is spray-dried to obtain spherical particles; the spherical particles are immersed in acid solution for reaction, and the solid phase obtained by centrifugation is calcined to obtain macroporous silica with a pore size of 50-100 nm. The calcium carbonate whiskers have a diameter of 20-50 nm and a length of 500-1000 nm. The carbohydrate compound is one or more of starch, glucose, sucrose and fructose; the mass ratio of the carbohydrate compound to the silica sol is 1:(5-10).

[0014] By adopting the above technical solution, this application utilizes the synergistic effect of dual templates in macroporous silica. Calcium carbonate provides a rigid template, while carbohydrate compounds act as a soft template to assist in pore formation and enhance moldability, reducing dependence on a single template. Acid immersion dissolves calcium carbonate and partially etches the template, while calcination removes the carbohydrate template and solidifies the silica framework. Both the carbohydrate compounds and calcium carbonate used in this preparation method are inexpensive raw materials, making it economically viable. Furthermore, no organic solvents are used in the template removal process, and the calcination exhaust gas mainly consists of CO2 and water vapor, making it environmentally friendly.

[0015] Preferably, the method for preparing the mesoporous silica includes the following steps: Polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer (P123) was added to water and stirred until completely dissolved. Concentrated hydrochloric acid was added to adjust the pH to 1-2, and the mixture was stirred until homogeneous to form a transparent solution. 1,3,5-trimethylbenzene (TMB) was added to the transparent solution and stirred until homogeneous. Then, tetraethyl orthosilicate (TEOS) was added dropwise and stirred until homogeneous to obtain a reaction solution. The reaction solution was aged and hydrothermally cured to obtain the product. The product was filtered, dried, and calcined to obtain mesoporous silica with a pore size of 20-40 nm.

[0016] The molar ratio of TMB to TEOS is (3-5):(4-6). The molar ratio of P123 to TEOS is 1:(8-10).

[0017] By employing the above technical solution, the mesoporous silica preparation method of this application uses triblock copolymer P123 as a template agent and trimethylbenzene (TMB) as a pore-expanding agent for synthesis. In acidic solution, P123 forms spherical or rod-shaped micelles, with hydrophobic PPO segments agglomerating to form the core, and hydrophilic PEO segments facing outwards in contact with the aqueous phase. TEOS hydrolyzes under acidic conditions to generate silicic acid, which is adsorbed onto the micelle surface through hydrogen bonding or electrostatic interactions, gradually condensing to form a silica network. TMB, as an oil phase molecule, dissolves in the PPO core, increasing the micelle size and thus forming larger mesopores after calcination. Finally, low-temperature aging promotes further condensation of silicic acid, enhancing the integrity of the silica framework. High-temperature hydrothermal curing induces a more ordered micelle arrangement, forming a hexagonal mesoporous structure, while simultaneously improving pore thickness and stability. The mesoporous silica prepared by this method possesses the advantages of ordered structure, adjustable pore size, and high stability.

[0018] Preferably, in S1, the nano-calcium carbonate undergoes modification treatment, specifically by: dispersing nano-calcium carbonate in deionized water and adjusting the pH to 8-9 to obtain a calcium carbonate suspension; dissolving a long-chain quaternary ammonium salt in hot water at 60-70°C, adding the calcium carbonate suspension, stirring and reacting for 1-2 hours, and after the reaction is completed, naturally cooling and washing, centrifuging and drying to obtain modified nano-calcium carbonate.

[0019] By adopting the above technical solution, the long-chain quaternary ammonium salt on the surface of calcium carbonate can form hydrogen bonds or dipole-dipole interactions with the silanol groups on the surface of silica, thereby enhancing the interfacial bonding force and preventing particle desorption after filling. At the same time, the hydrophobic alkyl chain of the long-chain quaternary ammonium salt can interact with the organic template remaining in the silica pores through van der Waals forces, further anchoring the calcium carbonate particles and improving the bonding between nano-calcium carbonate and silica.

[0020] Preferably, the chlorinated butyl rubber is subjected to plasma treatment using argon or nitrogen.

[0021] By adopting the above technical solution, plasma treatment of chlorinated butyl rubber can reduce surface polar groups and form a nanoscale rough structure, thereby reducing the adsorption of biomolecules such as proteins. This results in chlorinated butyl rubber that is chemically inert and has low adsorption, meeting pharmaceutical standards.

[0022] Preferably, the vulcanizing agent is a mixture of pharmaceutical-grade magnesium oxide and pharmaceutical-grade zinc oxide in a mass ratio of (5-7):(3-5); the accelerator is stearic acid.

[0023] By adopting the above technical solution, the chlorine atoms in chlorinated butyl rubber react with metal oxides to form chemical bonds and achieve cross-linking. It is sulfur-free and nitrogen-free, and the vulcanization products have high chemical inertness, allowing direct contact with pharmaceuticals. At the same time, the vulcanization process is stable and does not easily produce by-products.

[0024] In rubber vulcanization systems, stearic acid can react with magnesium oxide and zinc oxide. It can form zinc stearate with zinc oxide, which can promote the vulcanization reaction, increase the degree of cross-linking between rubber molecular chains, and improve the physical properties of vulcanized rubber. At the same time, stearic acid can also improve the dispersion of magnesium oxide and zinc oxide in rubber, allowing them to be more evenly distributed in the rubber matrix and fully exert their vulcanization activity.

[0025] Preferably, the softening plasticizer is a mixture of pharmaceutical petrolatum and low molecular weight polyisobutylene in a mass ratio of (1-3):1.

[0026] By adopting the above technical solution, both petrolatum (a nonpolar alkane) and low molecular weight polyisobutylene (PIB) are highly compatible with the nonpolar segments of CIIR, forming a homogeneous system. Petrolatum is a semi-solid at room temperature, providing moderate softness and internal lubrication to prevent the rubber compound from sticking to rollers. During high-temperature mixing, it melts into a liquid, improving the dispersibility of reinforcing fillers. Low molecular weight PIB, on the other hand, is a viscous liquid at room temperature, which can penetrate between rubber molecular chains, lowering the glass transition temperature and enhancing the ductility of the rubber compound. Both petrolatum and PIB molecules contain saturated C-C / CH bonds and lack active groups such as hydroxyl, carboxyl, and double bonds. They do not chemically react with vulcanizing agents (MgO, ZnO) and accelerators (stearic acid), thus avoiding delayed vulcanization or reduced crosslinking density. Rubber products made from them can withstand acidic and alkaline substances in pharmaceuticals and polar solvents, and are not easily swollen or degraded. At the same time, both petrolatum and PIB have antioxidant and ozone-resistant properties, which can delay the hardening or embrittlement of rubber products during long-term storage. When used in combination, the crystalline network of petrolatum complements the amorphous segments of PIB, achieving stable performance over a wide temperature range.

[0027] Preferably, the antioxidant is a mixture of di-tert-butyl-p-cresol (BHT), antioxidant 1010, and vitamin E in a mass ratio of (3-5):(3-5):2.

[0028] By employing the above-mentioned technical solutions, BHT rapidly captures free radicals generated by rubber oxidation, exhibiting significant initial antioxidant effects. However, its low molecular weight may lead to higher volatility and migration. Antioxidant 1010, on the other hand, has a large molecular weight, excellent long-term heat aging resistance, and can remain stable in the rubber matrix, making it suitable for long-term protection. Vitamin E, with its biocompatibility and low toxicity, can assist in the scavenging of free radicals. The combination of BHT, antioxidant 1010, and vitamin E in this application, through a synergistic mechanism of rapid onset of action at low molecular weight, long-term stability at high molecular weight, and safe enhancement from natural ingredients, can significantly improve the antioxidant properties of pharmaceutical rubber.

[0029] Secondly, this application provides a method for preparing a pharmaceutical-grade chlorinated butyl rubber sealing ring, employing the following technical solution: A method for preparing a pharmaceutical-grade chlorinated butyl rubber sealing ring includes the following steps: Weigh the raw materials according to the compounding ratio, add chlorinated butyl rubber to the mixer and mix, add softening plasticizer after wrapping the roller and continue mixing, then add reinforcing filler and antioxidant in sequence and mix evenly, finally add vulcanizing agent and accelerator and continue mixing until uniform to obtain the mixture. The mixture is vulcanized at a temperature of 140-160℃ and a pressure of 10-20 MPa for 10-30 minutes to obtain the pharmaceutical chlorinated butyl rubber sealing ring.

[0030] In summary, this application has the following beneficial effects: 1. The reinforcing filler in this application is a CaCO3@SiO2@PDA@G composite particle. Through the interaction of polar groups, chemical bonding and filler network, the binding of the reinforcing filler with chlorinated butyl rubber is improved, which significantly enhances the mechanical properties and air tightness of the rubber.

[0031] 2. The porous silica in this application is a mixture of mesoporous silica and macroporous silica, which can not only improve the reinforcing effect of CaCO3@SiO2 particles on the rubber matrix, but also give the rubber sealing ring higher tensile strength and tear resistance.

[0032] 3. After plasma treatment, the polarity of the rubber surface is enhanced, the interfacial force with the filler is increased, and agglomeration is reduced; at the same time, the surface roughness is increased after treatment, the mechanical meshing effect with the metal / plastic interface is enhanced, and the sealing performance of the sealing ring is improved. Attached Figure Description

[0033] Figure 1 TEM image of SiO2 prepared in Preparation Example 5; Figure 2 TEM image of CaCO3@SiO2 prepared in Preparation Example 11. Detailed Implementation

[0034] The present application will be further described in detail below with reference to the embodiments.

[0035] Unless otherwise specified, the raw materials used in the preparation examples, embodiments, and comparative examples of this application are all commercially available.

[0036] Preparation Examples 1-3 Macroporous Silica Preparation Example 1 This preparation example discloses a method for preparing macroporous silica, specifically including the following steps: Add 5g of glucose to 100ml of deionized water and sonicate until completely dissolved to obtain a sugar solution. Slowly pour 25g of silica sol (silica content of 40%) into the sugar solution while stirring. After the addition is complete, sonicate for 20 minutes to obtain mixture A. Weigh 2.5g of calcium carbonate whiskers with an average diameter of 20nm and a length of 500-1000nm, and add them to mixture A in 5 portions. While adding the whiskers, stir with a magnetic stirrer at 400rpm for 30min to obtain the mixture. Start the spray dryer, set the inlet temperature to 180℃ and the outlet temperature to 80℃. After the temperature stabilizes, start feeding by pouring the mixture into the feed tank, adjusting the feed rate to 5ml / min and the atomization pressure to 0.2Mpa, forming droplets that are sprayed into the drying chamber for drying to obtain spherical particles. Spherical particles were poured into a 1 mol / L hydrochloric acid solution and magnetically stirred at 250 rpm at room temperature. The solution gradually became turbid until no more bubbles were produced, indicating the end of the reaction. The resulting mixture was centrifuged at 6000 rpm for 10 min, the supernatant was discarded, and the solid phase was collected. The solid phase was washed with deionized water until the washings were neutral and no Cl- was detected using silver nitrate solution. - ; The washed solid phase was dried in an oven at 70°C for 18 hours to remove moisture and obtain a dried precursor. The precursor was transferred to a crucible and placed in a muffle furnace. The temperature was increased from room temperature to 550°C at a rate of 5°C / min. After holding at this temperature for 2 hours, the furnace was cooled to room temperature to obtain macroporous silica powder with an average pore size of 50 nm.

[0037] Preparation Example 2 This preparation example discloses a method for preparing macroporous silica, specifically including the following steps: Add 5g of starch to 100ml of deionized water and sonicate until completely dissolved to obtain a sugar solution. Slowly pour 40g of silica sol (silica content of 40%) into the sugar solution while stirring. After the addition is complete, sonicate for 20 minutes to obtain mixture A. Weigh 4g of calcium carbonate whiskers with an average diameter of 30nm and a length of 500-1000nm, and add them to mixture A in 4 portions. While adding the whiskers, stir with a magnetic stirrer at 400rpm for 30min to obtain the mixture. Start the spray dryer, set the inlet temperature to 180℃ and the outlet temperature to 80℃. After the temperature stabilizes, start feeding by pouring the mixture into the feed tank, adjusting the feed rate to 5ml / min and the atomization pressure to 0.2Mpa, forming droplets that are sprayed into the drying chamber for drying to obtain spherical particles. Spherical particles were poured into a 1 mol / L hydrochloric acid solution and magnetically stirred at 250 rpm at room temperature. The solution gradually became turbid until no more bubbles were produced, indicating the end of the reaction. The resulting mixture was centrifuged at 6000 rpm for 10 min, the supernatant was discarded, and the solid phase was collected. The solid phase was washed with deionized water until the washings were neutral and no Cl- was detected using silver nitrate solution. - ; The washed solid phase was dried in an oven at 70°C for 18 hours to remove moisture and obtain a dried precursor. The precursor was transferred to a crucible and placed in a muffle furnace. The temperature was increased from room temperature to 550°C at a rate of 5°C / min. After holding at this temperature for 2 hours, the furnace was cooled to room temperature to obtain macroporous silica powder with an average pore size of 70 nm.

[0038] Preparation Example 3 This preparation example discloses a method for preparing macroporous silica, specifically including the following steps: Add 5g of sucrose to 100ml of deionized water and sonicate until completely dissolved to obtain a sugar solution. Slowly pour 50g of silica sol (silica content of 40%) into the sugar solution while stirring. After the addition is complete, sonicate for 20 minutes to obtain mixture A. Weigh 5g of calcium carbonate whiskers with an average diameter of 50nm and a length of 500-1000nm, and add them to mixture A in 4 portions. While adding the whiskers, stir with a magnetic stirrer at 400rpm for 30min to obtain the mixture. Start the spray dryer, set the inlet temperature to 180℃ and the outlet temperature to 80℃. After the temperature stabilizes, start feeding by pouring the mixture into the feed tank, adjusting the feed rate to 5ml / min and the atomization pressure to 0.2Mpa, forming droplets that are sprayed into the drying chamber for drying to obtain spherical particles. Spherical particles were poured into a 1 mol / L hydrochloric acid solution and magnetically stirred at 250 rpm at room temperature. The solution gradually became turbid until no more bubbles were produced, indicating the end of the reaction. The resulting mixture was centrifuged at 6000 rpm for 10 min, the supernatant was discarded, and the solid phase was collected. The solid phase was washed with deionized water until the washings were neutral and no Cl- was detected using silver nitrate solution. - ; The washed solid phase was dried in an oven at 70°C for 18 hours to remove moisture and obtain a dried precursor. The precursor was transferred to a crucible and placed in a muffle furnace. The temperature was increased from room temperature to 550°C at a rate of 5°C / min. After holding at this temperature for 2 hours, the furnace was cooled to room temperature to obtain macroporous silica powder with an average pore size of 100 nm.

[0039] Preparation Examples 4-6: Mesoporous Silica Preparation Example 4 This preparation example discloses a method for preparing mesoporous silica, specifically including the following steps: Dissolve 14.5g P123 in 80ml deionized water, heat in a water bath to 40°C, stir magnetically until completely dissolved, cool to room temperature, and add 37wt% concentrated hydrochloric acid dropwise while stirring until the pH reaches 1 to form a mixture. Add 2.09 ml of TMB to the mixture using a pipette at a rate of 1 drop / second, and continue stirring for 30 min to obtain a clear solution; add 4 ml of TEOS to the clear solution at a rate of 1 drop / second, and after the addition is complete, stir magnetically at room temperature for 24 h to obtain the reaction solution; The reaction solution was poured into a hydrothermal reactor lined with polytetrafluoroethylene. The hydrothermal reactor was placed in an oven and heated to 100°C at a rate of 5°C / min. After holding at this temperature for 24 hours, the mixture was naturally cooled to room temperature to obtain the hydrothermal product. The hydrothermal product was filtered and the filter cake was collected. The filter cake was washed three times with 50 ml of anhydrous ethanol, and then washed with deionized water until the pH of the filtrate was 7. The filter cake was placed in a vacuum drying oven and dried at 60 °C for 12 h to obtain the precursor. The precursor was placed in a muffle furnace and heated to 150°C at a rate of 1°C / min, and held for 1 hour; then heated to 550°C at a rate of 2°C / min and held for 4 hours, and cooled with the furnace to obtain mesoporous silica with an average pore size of 20 nm.

[0040] Preparation Example 5 This preparation example discloses a method for preparing mesoporous silica, specifically including the following steps: Dissolve 16.119g P123 in 80ml of deionized water, heat in a water bath to 40°C, stir magnetically until completely dissolved, cool to room temperature, and add 37wt% concentrated hydrochloric acid dropwise while stirring until the pH reaches 1 to form a mixture. Add 2.78 ml of TMB to the mixture using a pipette at a rate of 1 drop / second, and continue stirring for 30 min to obtain a clear solution; add 5 ml of TEOS to the clear solution at a rate of 1 drop / second, and after the addition is complete, stir magnetically at room temperature for 24 h to obtain the reaction solution; The reaction solution was poured into a hydrothermal reactor lined with polytetrafluoroethylene. The hydrothermal reactor was placed in an oven and heated to 100°C at a rate of 5°C / min. After holding at this temperature for 24 hours, the mixture was naturally cooled to room temperature to obtain the hydrothermal product. The hydrothermal product was filtered and the filter cake was collected. The filter cake was washed three times with 50 ml of anhydrous ethanol, and then washed with deionized water until the pH of the filtrate was 7. The filter cake was placed in a vacuum drying oven and dried at 60 °C for 12 h to obtain the precursor. The precursor was placed in a muffle furnace and heated to 150°C at a rate of 1°C / min, and held at that temperature for 1 hour; then heated to 550°C at a rate of 2°C / min and held for 4 hours. After furnace cooling, mesoporous silica with an average pore size of 30 nm was obtained, and the TEM image is shown below. Figure 1 As shown.

[0041] Preparation Example 6 This preparation example discloses a method for preparing mesoporous silica, specifically including the following steps: Dissolve 17.4g P123 in 40ml deionized water, heat in a water bath to 40°C, stir magnetically until completely dissolved, cool to room temperature, and add 37wt% concentrated hydrochloric acid dropwise while stirring until the pH reaches 1 to form a mixture. Add 3.48 ml of TMB to the mixture using a pipette at a rate of 1 drop / second, and continue stirring for 30 min to obtain a clear solution; add 6 ml of TEOS to the clear solution at a rate of 1 drop / second, and after the addition is complete, stir magnetically at room temperature for 24 h to obtain the reaction solution; The reaction solution was poured into a hydrothermal reactor lined with polytetrafluoroethylene. The hydrothermal reactor was placed in an oven and heated to 100°C at a rate of 5°C / min. After holding at this temperature for 24 hours, the mixture was naturally cooled to room temperature to obtain the hydrothermal product. The hydrothermal product was filtered and the filter cake was collected. The filter cake was washed three times with 50 ml of anhydrous ethanol, and then washed with deionized water until the pH of the filtrate was 7. The filter cake was placed in a vacuum drying oven and dried at 60 °C for 12 h to obtain the precursor. The precursor was placed in a muffle furnace and heated to 150°C at a rate of 1°C / min, and held for 1 hour; then heated to 550°C at a rate of 2°C / min and held for 4 hours, and cooled with the furnace to obtain mesoporous silica with an average pore size of 40 nm.

[0042] Preparation Example 7-20: CaCO3@SiO2 Particles Preparation Example 7 This preparation example discloses a method for preparing CaCO3@SiO2 particles, which specifically includes the following steps: S1. Add 5g of nano calcium carbonate to 100ml of deionized water and ultrasonically disperse for 30min at a power of 200W and a frequency of 40KHz to obtain a suspension. S2, take a 50mm diameter Buchner funnel, place a filter membrane on it, connect a vacuum pump, spread 15g of macroporous silica evenly on the filter membrane, pour the suspension onto the filter membrane, turn on the vacuum pump, and adsorb for 1h under a negative pressure of -0.07Mpa. After washing with deionized water, dry in a vacuum drying oven at 60℃ for 12h to obtain CaCO3@SiO2 particles. The average particle size of the nano-calcium carbonate is 40 nm, and the macroporous silica comes from Preparation Example 1.

[0043] Preparation Example 8 This preparation example discloses a method for preparing CaCO3@SiO2 particles, which specifically includes the following steps: S1. Add 5g of nano calcium carbonate to 100ml of deionized water and ultrasonically disperse for 30min at a power of 200W and a frequency of 40KHz to obtain a suspension. S2, take a 50mm diameter Buchner funnel, place a filter membrane on it, connect a vacuum pump, spread 20g of macroporous silica evenly on the filter membrane, pour the suspension onto the filter membrane, turn on the vacuum pump, and adsorb for 1h under a negative pressure of -0.07Mpa. After washing with deionized water, dry in a vacuum drying oven at 60℃ for 12h to obtain CaCO3@SiO2 particles. The average particle size of the nano-calcium carbonate is 50 nm, and the macroporous silica comes from preparation example 2.

[0044] Preparation Example 9 This preparation example discloses a method for preparing CaCO3@SiO2 particles, which specifically includes the following steps: S1. Add 5g of nano calcium carbonate to 100ml of deionized water and ultrasonically disperse for 30min at a power of 200W and a frequency of 40KHz to obtain a suspension. S2, take a 50mm diameter Buchner funnel, place a filter membrane on it, connect a vacuum pump, spread 25g of macroporous silica evenly on the filter membrane, pour the suspension onto the filter membrane, turn on the vacuum pump, and adsorb for 1h under a negative pressure of -0.07Mpa. After washing with deionized water, dry in a vacuum drying oven at 60℃ for 12h to obtain CaCO3@SiO2 particles. The average particle size of the nano-calcium carbonate is 80 nm, and the macroporous silica comes from preparation example 3.

[0045] Preparation Example 10 This preparation example discloses a method for preparing CaCO3@SiO2 particles, which specifically includes the following steps: S1. Add 5g of nano calcium carbonate to 100ml of deionized water and ultrasonically disperse for 30min at a power of 200W and a frequency of 40KHz to obtain a suspension. S2, take a 50mm diameter Buchner funnel, place a filter membrane on it, connect a vacuum pump, spread 25g of mesoporous silica evenly on the filter membrane, pour the suspension onto the filter membrane, turn on the vacuum pump, and adsorb for 1h under a negative pressure of -0.07Mpa. After washing with deionized water, dry in a vacuum drying oven at 60℃ for 12h to obtain CaCO3@SiO2 particles. The average particle size of the nano-calcium carbonate is 10 nm, and the mesoporous silica comes from preparation example 4.

[0046] Preparation Example 11 This preparation example discloses a method for preparing CaCO3@SiO2 particles, which specifically includes the following steps: S1. Add 5g of nano calcium carbonate to 100ml of deionized water and ultrasonically disperse for 30min at a power of 200W and a frequency of 40KHz to obtain a suspension. S2, take a 50mm diameter Buchner funnel, place a filter membrane on it, connect a vacuum pump, and evenly spread 30g of mesoporous silica on the filter membrane. Pour the suspension onto the filter membrane, turn on the vacuum pump, and adsorb for 1 hour under a negative pressure of -0.07Mpa. After washing with deionized water, dry in a vacuum drying oven at 60℃ for 12 hours to obtain CaCO3@SiO2 particles, and their TEM image is shown below. Figure 2 As shown.

[0047] The average particle size of the nano-calcium carbonate is 20 nm, and the mesoporous silica comes from Preparation Example 5.

[0048] Combination Figure 1 and Figure 2 It can be seen that, from Figure 1 The nanoparticle channels of mesoporous silica are clearly visible; while... Figure 2 In the image, no pores are visible, but it can be seen that nano-calcium carbonate fills the pores of mesoporous silica.

[0049] Preparation Example 12 This preparation example discloses a method for preparing CaCO3@SiO2 particles, which specifically includes the following steps: S1. Add 5g of nano calcium carbonate to 100ml of deionized water and ultrasonically disperse for 30min at a power of 200W and a frequency of 40KHz to obtain a suspension. S2, take a 50mm diameter Buchner funnel, place a filter membrane on it, connect a vacuum pump, spread 35g of mesoporous silica evenly on the filter membrane, pour the suspension onto the filter membrane, turn on the vacuum pump, and adsorb for 1h under a negative pressure of -0.07Mpa. After washing with deionized water, dry in a vacuum drying oven at 60℃ for 12h to obtain CaCO3@SiO2 particles. The average particle size of the nano-calcium carbonate is 30 nm, and the mesoporous silica comes from preparation example 6.

[0050] Preparation Example 13 In this preparation example, the CaCO3@SiO2 particles were a mixture of 3g macroporous CaCO3@SiO2 particles and 7g mesoporous CaCO3@SiO2 particles, wherein the macroporous CaCO3@SiO2 particles were from Preparation Example 7 and the mesoporous CaCO3@SiO2 particles were from Preparation Example 10.

[0051] Preparation Example 14 In this preparation example, the CaCO3@SiO2 particles were a mixture of 4g macroporous CaCO3@SiO2 particles and 6g mesoporous CaCO3@SiO2 particles, wherein the macroporous CaCO3@SiO2 particles were from Preparation Example 7 and the mesoporous CaCO3@SiO2 particles were from Preparation Example 10.

[0052] Preparation Example 15 In this preparation example, the CaCO3@SiO2 particles are a mixture of 5g macroporous CaCO3@SiO2 particles and 5g mesoporous CaCO3@SiO2 particles, wherein the macroporous CaCO3@SiO2 particles are from Preparation Example 7 and the mesoporous CaCO3@SiO2 particles are from Preparation Example 10.

[0053] Preparation Example 16 In this preparation example, the CaCO3@SiO2 particles were a mixture of 4g macroporous CaCO3@SiO2 particles and 6g mesoporous CaCO3@SiO2 particles, wherein the macroporous CaCO3@SiO2 particles were from Preparation Example 7 and the mesoporous CaCO3@SiO2 particles were from Preparation Example 11.

[0054] Preparation Example 17 In this preparation example, the CaCO3@SiO2 particles were a mixture of 4g macroporous CaCO3@SiO2 particles and 6g mesoporous CaCO3@SiO2 particles, wherein the macroporous CaCO3@SiO2 particles were from Preparation Example 7 and the mesoporous CaCO3@SiO2 particles were from Preparation Example 12.

[0055] Preparation Example 18 In this preparation example, the CaCO3@SiO2 particles were a mixture of 4g macroporous CaCO3@SiO2 particles and 6g mesoporous CaCO3@SiO2 particles, wherein the macroporous CaCO3@SiO2 particles were from Preparation Example 8 and the mesoporous CaCO3@SiO2 particles were from Preparation Example 11.

[0056] Preparation Example 19 In this preparation example, the CaCO3@SiO2 particles were a mixture of 4g macroporous CaCO3@SiO2 particles and 6g mesoporous CaCO3@SiO2 particles, wherein the macroporous CaCO3@SiO2 particles were from Preparation Example 9 and the mesoporous CaCO3@SiO2 particles were from Preparation Example 11.

[0057] Preparation Example 20 This preparation example is basically the same as Preparation Example 18, except that the nano-calcium carbonate used in the preparation of macroporous CaCO3@SiO2 particles and mesoporous CaCO3@SiO2 particles has been modified. Specifically, 5g of nano-calcium carbonate particles were added to 50ml of deionized water and ultrasonically dispersed for 30min at a power of 300W. The pH was adjusted to 8 with ammonia to obtain a suspension. 1g of hexadecyltrimethylammonium bromide was added to 50ml of deionized water and heated to 60℃ to form a mixture. The suspension was added to the mixture, and the system temperature was maintained at 60℃. The mixture was stirred for 2h, and the solid and liquid phases were separated. The obtained solid phase was repeatedly washed with deionized water and ethanol and dried at 60℃ to constant weight to obtain modified nano-calcium carbonate particles. The potential of the modified nano-calcium carbonate particles was tested using a Zeta potentiometer, and it was found that the surface of the modified nano-calcium carbonate was positively charged.

[0058] Preparation Examples 21-36 Reinforcing Fillers Preparation Example 21 This preparation example discloses a method for preparing a reinforcing filler, which specifically includes the following steps: (1) Add 1g of CaCO3@SiO2 particles to 100ml of Tris-HCl buffer solution with pH 8.5 and sonicate for 15min at 300W to obtain a suspension; dissolve 100mg of dopamine hydrochloride in 10ml of deionized water and add it dropwise to the suspension. Stir magnetically at room temperature for 6h, centrifuge, and sonicate the precipitate with a mixture of 50mL of deionized water and 20mL of anhydrous ethanol for 5min. Repeat centrifugation and washing 2-3 times until the supernatant is colorless to obtain the filler; add 1g of filler to 50ml of deionized water and sonicate for 10min to form a filler suspension; (2) 20 mg of graphene was added to 50 ml of deionized water and sonicated at 400 W for 30 min to form a graphene suspension. The graphene suspension was added to the filler suspension and magnetically stirred at 300 rpm for 2 h at room temperature. After centrifugation, the precipitate was washed twice with a mixture of 50 mL of deionized water and 50 mL of anhydrous ethanol. After ultrasonic dispersion for 5 min, it was centrifuged and dried in a vacuum drying oven at 60 °C for 12 h to obtain CaCO3@SiO2@PDA@G composite particles. The CaCO3@SiO2 particles were prepared in Example 7.

[0059] Preparation Example 22 This preparation example discloses a method for preparing a reinforcing filler, which specifically includes the following steps: (1) Add 1g of CaCO3@SiO2 particles to 100ml of Tris-HCl buffer solution with pH 8.5 and sonicate at 300W for 15min to obtain a suspension; dissolve 150mg of dopamine hydrochloride in 10ml of deionized water and add it dropwise to the suspension. Stir magnetically at room temperature for 6h, centrifuge, and sonicate the precipitate with a mixture of 50mL of deionized water and 20mL of anhydrous ethanol for 5min. Repeat centrifugation and washing 2-3 times until the supernatant is colorless to obtain the filler; add 1g of filler to 50ml of deionized water and sonicate for 10min to form a filler suspension; (2) 40 mg of graphene was added to 50 ml of deionized water and sonicated at 400 W for 30 min to form a graphene suspension. The graphene suspension was added to the filler suspension and magnetically stirred at 300 rpm for 2 h at room temperature. After centrifugation, the precipitate was washed twice with a mixture of 50 mL of deionized water and 50 mL of anhydrous ethanol. After ultrasonic dispersion for 5 min, it was centrifuged and dried in a vacuum drying oven at 60 °C for 12 h to obtain CaCO3@SiO2@PDA@G composite particles. The CaCO3@SiO2 particles were prepared in Example 7.

[0060] Preparation Example 23 This preparation example discloses a method for preparing a reinforcing filler, which specifically includes the following steps: (1) Add 1g of CaCO3@SiO2 particles to 100ml of Tris-HCl buffer solution with pH 8.5 and sonicate at 300W for 15min to obtain a suspension; dissolve 200mg of dopamine hydrochloride in 10ml of deionized water and add it dropwise to the suspension. Stir magnetically at room temperature for 6h, centrifuge, and sonicate the precipitate with a mixture of 50mL of deionized water and 20mL of anhydrous ethanol for 5min. Repeat centrifugation and washing 2-3 times until the supernatant is colorless to obtain the filler; add 1g of filler to 50ml of deionized water and sonicate for 10min to form a filler suspension; (2) 50 mg of graphene was added to 50 ml of deionized water and sonicated at 400 W for 30 min to form a graphene suspension. The graphene suspension was added to the filler suspension and magnetically stirred at 300 rpm for 2 h at room temperature. After centrifugation, the precipitate was washed twice with a mixture of 50 mL of deionized water and 50 mL of anhydrous ethanol. After ultrasonic dispersion for 5 min, it was centrifuged and dried in a vacuum drying oven at 60 °C for 12 h to obtain CaCO3@SiO2@PDA@G composite particles. The CaCO3@SiO2 particles were prepared in Example 7.

[0061] Preparation Example 24 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 8.

[0062] Preparation Example 25 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 9.

[0063] Preparation Example 26 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 10.

[0064] Preparation Example 27 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 11.

[0065] Preparation Example 28 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 12.

[0066] Preparation Example 29 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 13.

[0067] Preparation Example 30 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 14.

[0068] Preparation Example 31 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 15.

[0069] Preparation Example 32 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 16.

[0070] Preparation Example 33 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 17.

[0071] Preparation Example 34 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 18.

[0072] Preparation Example 35 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 19.

[0073] Preparation Example 36 This preparation example is basically the same as preparation example 22, except that the CaCO3@SiO2 particles are from preparation example 20.

[0074] Example 1 This embodiment provides a pharmaceutical-grade chlorinated butyl rubber sealing ring, comprising 60g of chlorinated butyl rubber, 0.5g of pharmaceutical-grade magnesium oxide, 0.5g of pharmaceutical-grade zinc oxide, 0.5g of stearic acid, 30g of reinforcing filler, 0.15g of BHT, 0.25g of antioxidant 1010, 0.1g of vitamin E, 11.25g of pharmaceutical-grade petrolatum, and 3.75g of polyisobutylene; The reinforcing filler was from Preparation Example 21, and the polyisobutylene had a molecular weight of 1000.

[0075] This embodiment also provides a method for preparing the above-mentioned pharmaceutical chlorinated butyl rubber sealing ring, comprising the following steps: Chlorinated butyl rubber was added to a mixer according to the above proportions and mixed at a speed of 60 r / min until it wrapped the rollers. Pharmaceutical petrolatum and low molecular weight polyisobutylene were added and mixed for another 5 min. Then, reinforcing filler, BHT, antioxidant 1010 and vitamin E were added in sequence and mixed for another 5 min. Finally, pharmaceutical grade magnesium oxide, pharmaceutical grade zinc oxide and stearic acid were added and mixed at a speed of 40 r / min for another 4 min to obtain the mixture. Preheat the mold to 150°C, put the mixture into the mold cavity, and vulcanize it under a pressure of 15 MPa for 20 minutes to obtain a pharmaceutical chlorinated butyl rubber sealing ring.

[0076] Example 2 This embodiment is basically the same as Embodiment 1, except that it includes 75g of chlorinated butyl rubber, 1.2g of pharmaceutical grade magnesium oxide, 0.8g of pharmaceutical grade zinc oxide, 1.5g of stearic acid, 20g of reinforcing filler, 0.6g of BHT, 0.6g of antioxidant 1010, 0.3g of vitamin E, 6.7g of pharmaceutical grade petrolatum, and 3.3g of polyisobutylene.

[0077] Example 3 This embodiment is basically the same as Embodiment 1, except that it includes 85g of chlorinated butyl rubber, 1.4g of pharmaceutical grade magnesium oxide, 0.6g of pharmaceutical grade zinc oxide, 2g of stearic acid, 10g of reinforcing filler, 1g of BHT, 0.6g of antioxidant 1010, 0.4g of vitamin E, 2.5g of pharmaceutical grade petrolatum, and 2.5g of polyisobutylene.

[0078] Example 4 This embodiment is basically the same as Embodiment 2, except that the chlorinated butyl rubber is treated with plasma. Specifically, the chlorinated butyl rubber is placed in the plasma chamber, the vacuum pump is started, the pressure inside the chamber is reduced to a low vacuum state, argon gas is introduced at a flow rate of 15 sccm to maintain the pressure inside the chamber, and the modified chlorinated butyl rubber is obtained after treatment at a power of 100W for 20 minutes.

[0079] Example 5 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 22.

[0080] Example 6 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 23.

[0081] Example 7 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 24.

[0082] Example 8 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 25.

[0083] Example 9 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 26.

[0084] Example 10 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 27.

[0085] Example 11 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 28.

[0086] Example 12 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 29.

[0087] Example 13 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 30.

[0088] Example 14 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 31.

[0089] Example 15 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 32.

[0090] Example 16 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 33.

[0091] Example 17 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 34.

[0092] Example 18 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 35.

[0093] Example 19 This embodiment is basically the same as Example 4, except that the reinforcing filler is from Preparation Example 36.

[0094] Comparative Example 1 The difference between this comparative example and Example 1 is as follows: The reinforcing filler consists of 0.6g graphene, 24.5g macroporous silica, and 4.9g nano-calcium carbonate. The average particle size of the nano-calcium carbonate is 40 nm, and the macroporous silica comes from Preparation Example 1.

[0095] Comparative Example 2 The difference between this comparative example and Example 9 is as follows: The reinforcing filler consists of 0.6g graphene, 24.5g mesoporous silica, and 4.9g nano-calcium carbonate. The average particle size of the nano-calcium carbonate is 10 nm, and the mesoporous silica comes from preparation example 4.

[0096] Performance testing Testing standards: Air tightness: GB7755-87 Tensile strength: GB / T528-1992 Tear resistance: GB / T529-1999 The chlorinated butyl rubber sealing rings prepared in Examples 1-19 and Comparative Examples 1-2 were subjected to the above tests, and the test results are shown in Table 1.

[0097] Table 1. Performance test data of chlorinated butyl rubber seals in Examples 1-19 and Comparative Examples 1-2.

[0098] Referring to Table 1, and in conjunction with Example 1 and Comparative Example 1, it can be seen that the CaCO3@SiO2 formed by filling the pores of macroporous silica with nano-calcium carbonate and then combining it with graphene through the bridging effect of polydopamine to form CaCO3@SiO2@PDA@G composite particles have a good bonding effect with other components of chlorinated butyl rubber sealing rings, thereby improving the airtightness, tensile properties and tear resistance of the prepared sealing rings.

[0099] Referring to Table 1, and in conjunction with Example 9 and Comparative Example 2, it can be seen that this application forms a "hard core-elastic shell" structure by filling nano-calcium carbonate into the pores of mesoporous silica. This utilizes the rigid support of calcium carbonate while mitigating filler agglomeration through the porous silica shell, achieving a balance between rigidity and flexibility. Simultaneously, polydopamine (PDA) coats the surface of CaCO3@SiO2 particles through self-polymerization, and it combines with graphene through multiple interactions such as π-π stacking, hydrogen bonding, and covalent bonds. The resulting CaCO3@SiO2@PDA@G composite particles exhibit good bonding with chlorinated butyl rubber through polar group interactions, chemical bonding, and filler network, significantly improving the mechanical properties and airtightness of the rubber sealing ring.

[0100] Referring to Table 1 and in conjunction with Examples 1 and 4, it can be seen that this application modifies chlorinated butyl rubber by argon plasma. After plasma treatment, the surface polarity of the rubber is enhanced, the interfacial force with the filler is increased, and agglomeration is reduced. At the same time, the surface roughness increases after treatment, the mechanical meshing effect with the metal / plastic interface is enhanced, and the sealing performance of the sealing ring is improved.

[0101] Referring to Table 1 and in conjunction with Examples 5, 9, and 12, it can be seen that the porous silica in this application uses a mixture of macroporous silica and mesoporous silica. The combined use of mesoporous and macroporous silica not only satisfies the filling requirements of nano-calcium carbonate with different particle sizes, but also improves the filling rate of nano-calcium carbonate, thereby enhancing the reinforcing effect of the prepared CaCO3@SiO2 particles on the rubber matrix. Furthermore, mesoporous silica has a high specific surface area, which tightly binds to the chlorinated butyl rubber molecular chains through a hydrogen bond network, increasing the tensile strength of the sealing ring. Simultaneously, the large pores of macroporous silica allow the rubber molecular chains to cross-link and form a mechanical spring structure, exhibiting strong stress dispersion capabilities and reducing the risk of cracking in the sealing ring. By filling nano-calcium carbonate of different particle sizes into matching mesoporous and macroporous silica, this application not only improves the reinforcing effect of CaCO3@SiO2 particles on the rubber matrix but also gives the rubber sealing ring higher strength and tear resistance.

[0102] Referring to Table 1 and in conjunction with Examples 17 and 19, it can be seen that this application modifies the surface of nano-calcium carbonate to make its surface cationic. The cationic forms hydrogen bonds or dipole-dipole interactions with the silanol groups on the surface of silica, enhancing the interfacial bonding force and preventing particle desorption after filling. At the same time, the hydrophobic alkyl chain of the long-chain quaternary ammonium salt can interact with the organic template remaining in the silica pores through van der Waals forces, further anchoring the calcium carbonate particles, improving the adsorption of nano-calcium carbonate on porous silica, and further improving the airtightness and mechanical properties of the prepared sealing ring.

[0103] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A pharmaceutical-grade chlorinated butyl rubber sealing ring, characterized in that, It is made from the following raw materials in parts by weight: 60-85 parts chlorinated butyl rubber, 1-3 parts vulcanizing agent, 0.5-2 parts accelerator, 10-30 parts reinforcing filler, 0.5-2 parts antioxidant, and 5-15 parts softening plasticizer; the preparation method of the reinforcing filler includes the following steps: (1) Fill the pores of porous silica with nano-calcium carbonate to form core-shell CaCO3@SiO2 particles; (2) CaCO3@SiO2 particles were added to Tris-HCl buffer and ultrasonically dispersed. Dopamine hydrochloride was then added and stirred for 6-12 hours. The filler was obtained by filtration and washing. The filler was then added to water and ultrasonically dispersed to form a filler suspension. (3) After ultrasonically dispersing graphene in water, it is added to the filler suspension, stirred and reacted, and then centrifuged and dried to obtain CaCO3@SiO2@PDA@G composite particles; The mass ratio of dopamine hydrochloride, graphene, and CaCO3@SiO2 particles is (10-20):(2-5):

100.

2. The pharmaceutical-grade chlorinated butyl rubber sealing ring according to claim 1, characterized in that, Step (1), the method for preparing the CaCO3@SiO2 particles, includes the following steps: S1, nano-calcium carbonate is ultrasonically dispersed in deionized water to obtain a suspension; S2, the suspension is added to porous silica and vacuumed, and the CaCO3@SiO2 particles are obtained by negative pressure adsorption for 1-3 hours. The mass ratio of the nano-calcium carbonate to the porous silica is 1:(3-7).

3. The pharmaceutical-grade chlorinated butyl rubber sealing ring according to claim 2, characterized in that, The porous silica is a mixture of mesoporous silica and macroporous silica in a mass ratio of (5-7):(3-5).

4. The pharmaceutical-grade chlorinated butyl rubber sealing ring according to claim 3, characterized in that, The method for preparing the macroporous silica includes the following steps: The carbohydrate compound was dissolved in water, ultrasonically dispersed, and then silica sol was added and stirred evenly to obtain a mixture. The mixture is spray-dried to obtain spherical particles; the spherical particles are immersed in acid solution for reaction, and the solid phase obtained by centrifugation is calcined to obtain macroporous silica with a pore size of 50-100 nm. The calcium carbonate whiskers have a diameter of 20-50 nm and a length of 500-1000 nm. The carbohydrate compound is one or more of starch, glucose, sucrose and fructose; the mass ratio of the carbohydrate compound to the silica sol is 1:(5-10).

5. The pharmaceutical-grade chlorinated butyl rubber sealing ring according to claim 3, characterized in that, The method for preparing the mesoporous silica includes the following steps: Polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer was added to water and stirred until completely dissolved. Concentrated hydrochloric acid was added to adjust the pH to 1-2, and the mixture was stirred until a transparent solution was formed. 1,3,5-trimethylbenzene was added to the transparent solution and stirred until homogeneous. Tetramethyl orthosilicate was then added dropwise and stirred until homogeneous to obtain a reaction solution. The reaction solution was aged and hydrothermally cured to obtain the product. The product was filtered, dried, and calcined to obtain mesoporous silica with a pore size of 20-40 nm. The molar ratio of 1,3,5-trimethylbenzene to tetraethyl orthosilicate is (3-5):(4-6). The molar ratio of the polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer to tetraethyl orthosilicate is 1:(8-10).

6. The pharmaceutical-grade chlorinated butyl rubber sealing ring according to claim 2, characterized in that, In S1, the nano-calcium carbonate undergoes modification treatment, specifically: the nano-calcium carbonate is dispersed in deionized water and the pH is adjusted to 8-9 to obtain a calcium carbonate suspension; a long-chain quaternary ammonium salt is dissolved in hot water at 60-70℃, added to the calcium carbonate suspension, stirred and reacted for 1-2 hours, and after the reaction is completed, it is naturally cooled, washed, centrifuged, and dried to obtain modified nano-calcium carbonate.

7. The pharmaceutical-grade chlorinated butyl rubber sealing ring according to claim 1, characterized in that, The chlorinated butyl rubber is subjected to plasma treatment using argon or nitrogen.

8. The pharmaceutical-grade chlorinated butyl rubber sealing ring according to claim 1, characterized in that, The vulcanizing agent is a mixture of pharmaceutical-grade magnesium oxide and pharmaceutical-grade zinc oxide in a mass ratio of (5-7):(3-5); the accelerator is stearic acid.

9. The pharmaceutical-grade chlorinated butyl rubber sealing ring according to claim 1, characterized in that, The softening plasticizer is a mixture of pharmaceutical petrolatum and low molecular weight polyisobutylene in a mass ratio of (1-3):1; the antioxidant is a mixture of di-tert-butyl-p-cresol, antioxidant 1010 and vitamin E in a mass ratio of (3-5):(3-5):

2.

10. A method for preparing a pharmaceutical-grade chlorinated butyl rubber sealing ring as described in any one of claims 1-9, characterized in that, Includes the following steps: Weigh the raw materials according to the compounding ratio, add chlorinated butyl rubber to the mixer and mix, add softening plasticizer after wrapping the roller and continue mixing, then add reinforcing filler and antioxidant in sequence and mix evenly, finally add vulcanizing agent and accelerator and continue mixing until uniform to obtain the mixture. The mixture is vulcanized at a temperature of 140-160℃ and a pressure of 10-20 MPa for 10-30 minutes to obtain the pharmaceutical chlorinated butyl rubber sealing ring.

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