A layered rubber material, its preparation and use

Abstract

The application relates to the technical field of medical rubber materials, in particular to a layered rubber material and a preparation method and application thereof. The layered rubber material comprises, from top to bottom, a puncture rubber layer, a bacteriostatic rubber layer and a contact rubber layer; the raw materials of the puncture rubber layer mainly comprise ethylene-propylene-diene rubber, hydrogenated styrene-butadiene block copolymer and inorganic fillers; the raw materials of the bacteriostatic rubber layer mainly comprise aramid fiber modified butadiene styrene rubber and paeonol microcapsule modified isoprene rubber; and the raw materials of the contact rubber layer mainly comprise butyl rubber and chitosan. The layered rubber material has good puncture resistance and air tightness, is good in compatibility with medicines, and can effectively guarantee the quality of medicines by utilizing the synergistic effect of the raw material components. The application effectively solves the problems of poor air tightness, low compatibility with medicines and poor puncture resistance of the medical rubber plug in the prior art, and provides a new idea for the preparation of medical rubber materials.

Description

Technical Field

[0001] This invention relates to the field of medical rubber material preparation technology, specifically to a layered rubber material, its preparation method, and its application. Background Technology

[0002] Medical rubber stoppers play a crucial role in pharmaceutical packaging, sealing containers such as medicine bottles and infusion bottles to prevent leakage or contamination, while ensuring the stability of drug quality during storage and transportation. With the rapid development of the pharmaceutical industry, the requirements for drug quality and safety are increasingly stringent, prompting continuous research and innovation in medical rubber stopper materials. Ideal medical rubber stopper materials should possess excellent sealing properties, chemical stability, and biocompatibility to meet the packaging needs of various pharmaceutical products.

[0003] Existing medical rubber stopper materials mainly include butyl rubber, which has long been the primary material for medical rubber stoppers due to its excellent airtightness, chemical corrosion resistance, and low permeability. However, butyl rubber has a slow vulcanization rate, low production efficiency, and poor compatibility with certain drugs, potentially leading to visible foreign matter or chemical reactions in the drug, affecting drug quality. To address this, researchers have proposed materials such as silicone rubber, halogenated butyl rubber, or thermoplastic elastomers as alternatives to butyl rubber. However, silicone rubber has relatively poor airtightness, failing to meet the high airtightness requirements of pharmaceutical packaging; halogenated butyl rubber presents issues with extractable and leachable substances when exposed to oxidizing drugs, and also exhibits poor puncture resistance; thermoplastic elastomers still lag behind traditional butyl rubber in terms of sealing performance and long-term stability.

[0004] Therefore, developing a rubber material with good airtightness and high drug compatibility is of great practical significance for the development and innovation of medical rubber stoppers. Summary of the Invention

[0005] To address the problems of poor airtightness, low drug compatibility, and poor puncture resistance in existing medical rubber stoppers, this invention provides a layered rubber material, its preparation method, and its applications. The layered rubber material comprises a puncture rubber layer, an antibacterial rubber layer, and a contact rubber layer. Utilizing the synergistic effect of the various raw material components, the layered rubber material exhibits excellent puncture resistance and airtightness, good drug compatibility, and effectively ensures drug quality and stability, providing a new approach to the preparation of medical rubber materials.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: The first aspect of this invention provides a layered rubber material, which comprises, from top to bottom, a puncture rubber layer, an antibacterial rubber layer, and a contact rubber layer; wherein the puncture rubber layer comprises the following raw material components in parts by weight: 40-50 parts of ethylene propylene diene monomer (EPDM) rubber, 10-15 parts of hydrogenated styrene-butadiene block copolymer, 10-20 parts of inorganic filler, 1-5 parts of antioxidant, 1-3 parts of activator, and 1-3 parts of vulcanization aid; wherein the inorganic filler comprises titanium dioxide powder and phlogopite powder; The antibacterial rubber layer comprises the following raw material components in parts by weight: 30-50 parts of aramid fiber modified styrene-butadiene rubber, 15-20 parts of paeonol microcapsule modified isoprene rubber, 1-5 parts of antioxidant, 1-3 parts of activator and 1-3 parts of vulcanization aid. The contact rubber layer comprises the following raw material components in parts by weight: 40-60 parts butyl rubber, 1-5 parts chitosan, 1-5 parts antioxidant, 1-3 parts activator, and 1-3 parts vulcanization aid.

[0007] This invention designs a layered rubber material, comprising, from top to bottom, a puncture rubber layer, an antibacterial rubber layer, and a contact rubber layer. The puncture rubber layer exhibits excellent puncture resistance and abrasion resistance, serving as the surface material for medical rubber stoppers in contact with the external environment. The antibacterial rubber layer also acts as a supporting and connecting layer, not only connecting the surface material and the drug contact layer material but also preventing external bacterial contamination of the drug, thus improving drug quality and stability. The contact rubber layer material does not chemically react with the drug, exhibiting good drug compatibility and ensuring stable drug performance.

[0008] Hydrogenated styrene-butadiene block copolymers, due to their unique block structure, possess ethylene-butene blocks that provide excellent flexibility and elasticity. When blended with EPDM rubber, they make the rubber molecular chains more compliant, allowing for better slippage and rearrangement under puncture force, thus absorbing and dispersing puncture energy. Simultaneously, the strong entanglement between the hydrogenated styrene-butadiene block copolymer molecular chains and the rubber molecular chains makes the overall structure of the blend system more stable, improving the puncture resistance of the rubber material. Titanium dioxide significantly enhances the reinforcing properties of rubber, making rubber products more tough and wear-resistant, greatly extending the service life of rubber materials. Phlogopite powder added to rubber can significantly improve the mechanical strength and toughness of rubber materials; synergistically with titanium dioxide, it can enhance the puncture resistance of rubber.

[0009] Aramid fibers possess high tensile strength and modulus, as well as excellent heat resistance and chemical corrosion resistance. They can enhance the mechanical properties of styrene-butadiene rubber (SBR), improving its tear resistance, abrasion resistance, and puncture resistance. They also enhance SBR's resistance to chemical corrosion, maintaining better performance in environments exposed to oils, acids, alkalis, and other chemicals. The addition of paeonol microcapsules to modify isoprene rubber can improve the antibacterial properties and thermal stability of layered rubber materials. Paeonol has antibacterial and anti-inflammatory effects. When paeonol is made into microcapsules and added to isoprene rubber, the microcapsules slowly release paeonol through diffusion and permeation during rubber use, continuously exerting its properties. Furthermore, the interaction between the microcapsule wall material and the rubber molecular chains enhances the cohesive force of the isoprene rubber, improving the mechanical properties and thermal stability of the rubber material.

[0010] Since the contact rubber layer comes into direct contact with the pharmaceutical product, this invention adds chitosan to the contact rubber layer. Chitosan has certain barrier properties, which can improve the rubber's barrier properties against gases and liquids, enhance the sealing effect, and extend the service life of rubber products. Chitosan also has good antibacterial properties, and when used with butyl rubber, it can endow the rubber with antibacterial function, effectively inhibiting the growth and reproduction of bacteria and improving the safety performance of pharmaceutical products.

[0011] In summary, the layered rubber material of the present invention has good airtightness, puncture resistance and biocompatibility, which can effectively solve the problems of poor airtightness, low drug compatibility and poor puncture resistance of medical rubber stoppers in the prior art, and provides a new approach for the preparation of medical rubber stopper materials.

[0012] Preferably, the preparation method of the paeonol microcapsule modified isoprene rubber includes the following steps: S1. Dissolve the wall material in deionized water to obtain a wall material solution; add an alcoholic solution of paeonol to the wall material solution and mix well to obtain a core-wall mixture; spray dry the core-wall mixture to obtain paeonol microcapsules. S2. Isoprene rubber is subjected to intensive mixing at 50℃-60℃ to obtain intensively mixed rubber; the paeonol microcapsules are added to the intensively mixed rubber and then mixed to obtain a mixed rubber. S3. Add vulcanizing agent, accelerator and reinforcing agent to the mixed rubber, mix evenly, and vulcanize at 100℃-110℃ to obtain paeonol microcapsule modified isoprene rubber.

[0013] More preferably, in S1, the wall material is gum arabic or gelatin.

[0014] More preferably, in S1, the mass ratio of the wall material to the deionized water is 1:20-1:30.

[0015] More preferably, in S1, the mass ratio of the paeonol alcohol solution to the wall material solution is 1:10-1:20.

[0016] More preferably, in S1, the paeonol alcohol solution contains 60%-70% paeonol by mass.

[0017] More preferably, in S1, the inlet air temperature of the spray dryer is 90℃-100℃, the outlet air temperature is 80℃-90℃, the feed rate is 2mL / min-5mL / min, and the atomization pressure is 0.2MPa-0.4MPa.

[0018] More preferably, in S2, the mixing time is 5-10 minutes.

[0019] More preferably, in S2, the mass ratio of the paeonol microcapsules to the isoprene rubber is 3:100-8:100.

[0020] More preferably, in S2, the mixing temperature is 70-80℃ and the mixing time is 10-15 minutes.

[0021] More preferably, in S3, the amount of the vulcanizing agent added is 2%-3% of the mass of the mixed rubber.

[0022] More preferably, in S3, the amount of the accelerator added is 1%-2% of the mass of the mixed adhesive.

[0023] More preferably, in S3, the amount of reinforcing agent added is 5%-10% of the mass of the mixed adhesive.

[0024] More preferably, in S3, the vulcanizing agent is tetramethylthiuram disulfide.

[0025] More preferably, in S3, the accelerator is zinc diethyldithiocarbamate.

[0026] More preferably, in S3, the reinforcing agent is carbon black.

[0027] More preferably, in S3, the vulcanization time is 4 min-6 min, and the vulcanization pressure is 8 MPa-10 MPa.

[0028] Preferably, the preparation method of the aramid fiber modified styrene-butadiene rubber includes the following steps: Step a: Crush the aramid fiber to obtain short aramid fiber; disperse the short aramid fiber in a low-boiling-point organic solvent, filter, dry, and perform thermal oxidation treatment at 180℃-220℃ for 30min-50min to obtain pretreated aramid fiber; Step b: Mix the styrene-butadiene rubber at 65℃-75℃ for 10min-15min to obtain mixed styrene-butadiene rubber; add the pretreated aramid fiber to the mixed styrene-butadiene rubber and mix at 60℃-85℃ for 20min-25min to obtain a compound. Step c: Add vulcanizing agent, accelerator and reinforcing agent to the compound, mix evenly, and vulcanize at 150℃-170℃ to obtain aramid fiber modified styrene-butadiene rubber.

[0029] More preferably, in step a, the length of the short aramid fiber is 0.5mm-1.5mm.

[0030] More preferably, in step a, the low-boiling-point solvent is acetone.

[0031] More preferably, in step a, the mass-to-volume ratio of the short aramid fiber to the low-boiling-point organic solvent is 1g:3mL-1g:5mL.

[0032] More preferably, in step b, the mass ratio of the pretreated aramid fiber to the styrene-butadiene rubber is 1:10-1:20.

[0033] More preferably, in step c, the vulcanization pressure is 10MPa-20MPa, and the vulcanization time is 4min-8min.

[0034] More preferably, in step c, the amount of vulcanizing agent added is 2%-3% of the mass of the mixed rubber.

[0035] More preferably, in step c, the amount of the accelerator added is 1%-2% of the mass of the mixed adhesive.

[0036] More preferably, in step c, the amount of reinforcing agent added is 5%-8% of the mass of the mixed adhesive.

[0037] More preferably, in step c, the vulcanizing agent is sodium hexamethylenediamine carbamate.

[0038] More preferably, in step c, the accelerator is sodium dimethyl dithiocarbamate.

[0039] More preferably, in step c, the reinforcing agent is carbon black.

[0040] Preferably, the inorganic filler comprises titanium dioxide powder and phlogopite powder in a mass ratio of 1:2 to 1:5.

[0041] Preferably, the thickness of the puncture rubber layer is 450μm-800μm.

[0042] Preferably, the thickness of the antibacterial rubber layer is 250μm-500μm.

[0043] Preferably, the thickness of the contact rubber layer is 450μm-600μm.

[0044] Preferably, the antioxidant is antioxidant MB.

[0045] Preferably, the activator is stearic acid.

[0046] Preferably, the vulcanizing aid is sulfur and ethylene thiourea in a mass ratio of 1:2 to 1:3.

[0047] A second aspect of the present invention provides a method for preparing the aforementioned layered rubber material, comprising the following steps: Step 1: Weigh the raw materials of each component of the puncture rubber layer according to the design ratio, mix them evenly, vulcanize them at 160℃-180℃, and extrude them to obtain the puncture rubber layer material. Step 2: Weigh the raw materials of each component of the antibacterial rubber layer according to the design ratio, mix them evenly, vulcanize them at 160℃-180℃, and extrude them to obtain the antibacterial rubber layer material. Step 3: Weigh the raw materials of each component of the contact rubber layer according to the design ratio, mix them evenly, vulcanize them at 160℃-180℃, and extrude them to obtain the contact rubber layer material. Step 4: Stack the puncture rubber layer material, antibacterial rubber layer material and contact rubber layer material in sequence, and extrude them to obtain a layered rubber material.

[0048] Preferably, in step one, the vulcanization pressure is 10MPa-15MPa, and the vulcanization time is 4min-8min.

[0049] Preferably, in step two, the vulcanization pressure is 10MPa-15MPa, and the vulcanization time is 5min-10min.

[0050] Preferably, in step three, the vulcanization pressure is 10MPa-15MPa, and the vulcanization time is 5min-8min.

[0051] The third aspect of this invention provides an application of the layered rubber material described above, or the layered rubber material prepared by the method described above, in the field of preparing medical rubber stopper materials.

[0052] In summary, this invention provides a layered rubber material comprising a puncture-resistant rubber layer, an antibacterial rubber layer, and a contact rubber layer. By utilizing the interaction of the raw materials in each rubber layer, the layered rubber material exhibits excellent puncture resistance and airtightness, good compatibility with pharmaceuticals, and effectively ensures the quality and stability of pharmaceuticals. The technical solution of this invention effectively solves the problems of poor airtightness, low pharmaceutical compatibility, and poor puncture resistance in existing medical rubber stoppers, providing a new approach to the preparation of medical rubber materials. Detailed Implementation

[0053] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] Example 1 This embodiment provides a layered rubber material and its preparation method, specifically including the following: The layered rubber material comprises, from top to bottom, a puncture rubber layer, an antibacterial rubber layer, and a contact rubber layer; wherein, the puncture rubber layer comprises the following raw material components in parts by weight: 50 parts of EPDM rubber, 12 parts of hydrogenated styrene-butadiene block copolymer, 15 parts of inorganic filler, 3 parts of antioxidant MB, 2 parts of stearic acid, and 2 parts of sulfur and ethylene sulfur in a mass ratio of 1:2.5; wherein, the inorganic filler comprises titanium dioxide powder and phlogopite powder in a mass ratio of 1:4. The antibacterial rubber layer comprises the following raw material components in parts by weight: 35 parts of aramid fiber modified styrene-butadiene rubber, 18 parts of paeonol microcapsule modified isoprene rubber, 3 parts of antioxidant MB, 2 parts of stearic acid, and 2 parts of sulfur and ethylene sulfur in a mass ratio of 1:2.5. The contact rubber layer comprises the following raw material components in parts by weight: 50 parts butyl rubber, 3 parts chitosan, 3 parts antioxidant MB, 2 parts stearic acid, and 2 parts sulfur and ethylene thiourea in a mass ratio of 1:2.5.

[0055] The preparation method of the layered rubber material includes the following steps: Step 1: Weigh the raw materials of each component of the puncture rubber layer according to the design ratio, mix them evenly, vulcanize at 170℃ and 10MPa for 6 minutes, and extrude to obtain a puncture rubber layer material with a thickness of 680μm. Step 2: Weigh the raw materials of each component of the antibacterial rubber layer according to the design ratio, mix them evenly, vulcanize at 165℃ and 12MPa for 6 minutes, and extrude to obtain an antibacterial rubber layer material with a thickness of 370μm. Step 3: Weigh the raw materials of each component of the contact rubber layer according to the design ratio, mix them evenly, vulcanize at 175℃ and 13MPa for 8 minutes, and extrude to obtain a contact rubber layer material with a thickness of 500μm. Step 4: Stack the puncture rubber layer material, antibacterial rubber layer material and contact rubber layer material in sequence, and extrude them to obtain a layered rubber material.

[0056] The preparation method of the paeonol microcapsule-modified isoprene rubber includes the following steps: S1. Dissolve 30g of gum arabic in 800g of deionized water and heat to dissolve, obtaining a wall material solution; add 50g of an alcoholic solution of paeonol to the wall material solution and mix evenly to obtain a core-wall mixture; spray dry the core-wall mixture, setting the inlet air temperature to 95℃, the outlet air temperature to 85℃, the feed rate to 3mL / min, and the atomization pressure to 0.3MPa, to obtain paeonol microcapsules; S2. Mix 1 kg of isoprene rubber at 55°C for 8 min to obtain mixed rubber; add 50 g of paeonol microcapsules to the mixed rubber and mix at 75°C for 12 min to obtain mixed rubber. S3. Add 50g tetramethylthiuram disulfide, 30g zinc diethyldithiocarbamate and 100g carbon black to the mixed rubber, mix evenly, and vulcanize at 105℃ and 9MPa for 5min to obtain paeonol microcapsule modified isoprene rubber.

[0057] The preparation method of the aramid fiber modified styrene-butadiene rubber includes the following steps: Step a: Crush 200g of aramid fiber to obtain short aramid fiber with a length of 1mm; disperse the short aramid fiber in 800mL of acetone, filter, dry, and perform thermal oxidation treatment at 200℃ for 40min to obtain pretreated aramid fiber. Step b: Mix 3000g of styrene-butadiene rubber at 70°C for 12 minutes to obtain mixed styrene-butadiene rubber; add the pretreated aramid fiber to the mixed styrene-butadiene rubber and mix at 75°C for 20 minutes to obtain a compound. Step c: Add 80g of sodium hexamethylenediamine carbamate, 45g of sodium dimethyl dithiocarbamate and 200g of carbon black to the compound, mix evenly, and vulcanize at 165℃ and 15MPa for 5min to obtain aramid fiber modified styrene-butadiene rubber.

[0058] Example 2 This embodiment provides a layered rubber material and its preparation method, specifically including the following: The layered rubber material comprises, from top to bottom, a puncture rubber layer, an antibacterial rubber layer, and a contact rubber layer; wherein, the puncture rubber layer comprises the following raw material components in parts by weight: 45 parts EPDM rubber, 10 parts hydrogenated styrene-butadiene block copolymer, 12 parts inorganic filler, 5 parts antioxidant MB, 3 parts stearic acid, and 2 parts sulfur and ethylene sulfur in a mass ratio of 1:2.5; wherein, the inorganic filler comprises titanium dioxide powder and phlogopite powder in a mass ratio of 1:3; The antibacterial rubber layer comprises the following raw material components in parts by weight: 32 parts of aramid fiber modified styrene-butadiene rubber, 15 parts of paeonol microcapsule modified isoprene rubber, 5 parts of antioxidant MB, 3 parts of stearic acid, and 3 parts of sulfur and ethylene sulfur in a mass ratio of 1:2.5. The contact rubber layer comprises the following raw material components in parts by weight: 60 parts butyl rubber, 5 parts chitosan, 3 parts antioxidant MB, 2 parts stearic acid, and 2 parts sulfur and ethylene thiourea in a mass ratio of 1:2.

[0059] The preparation method of the layered rubber material includes the following steps: Step 1: Weigh the raw materials of each component of the puncture rubber layer according to the design ratio, mix them evenly, vulcanize at 160℃ and 10MPa for 8 minutes, and extrude to obtain a puncture rubber layer material with a thickness of 560μm. Step 2: Weigh the raw materials of each component of the antibacterial rubber layer according to the design ratio, mix them evenly, vulcanize at 165℃ and 12MPa for 7 minutes, and extrude to obtain an antibacterial rubber layer material with a thickness of 470μm. Step 3: Weigh the raw materials of each component of the contact rubber layer according to the design ratio, mix them evenly, vulcanize at 175℃ and 13MPa for 6 minutes, and extrude to obtain a contact rubber layer material with a thickness of 600μm. Step 4: Stack the puncture rubber layer material, antibacterial rubber layer material and contact rubber layer material in sequence, and extrude them to obtain a layered rubber material.

[0060] The preparation method of the paeonol microcapsule-modified isoprene rubber includes the following steps: S1. Dissolve 30g of gum arabic in 800g of deionized water and heat to dissolve, obtaining a wall material solution; add 50g of an alcoholic solution of paeonol to the wall material solution and mix evenly to obtain a core-wall mixture; spray dry the core-wall mixture, setting the inlet air temperature to 100℃, the outlet air temperature to 90℃, the feed rate to 3mL / min, and the atomization pressure to 0.3MPa, to obtain paeonol microcapsules; S2. Mix 1 kg of isoprene rubber at 55°C for 8 min to obtain mixed rubber; add 50 g of paeonol microcapsules to the mixed rubber and mix at 75°C for 12 min to obtain mixed rubber. S3. Add 50g tetramethylthiuram disulfide, 30g zinc diethyldithiocarbamate and 100g carbon black to the mixed rubber, mix evenly, and vulcanize at 110℃ and 9MPa for 5min to obtain paeonol microcapsule modified isoprene rubber.

[0061] The preparation method of the aramid fiber modified styrene-butadiene rubber includes the following steps: Step a: Crush 200g of aramid fiber to obtain short aramid fiber with a length of 1mm; disperse the short aramid fiber in 800mL of acetone, filter, dry, and perform thermal oxidation treatment at 200℃ for 40min to obtain pretreated aramid fiber. Step b: Mix 3000g of styrene-butadiene rubber at 70°C for 12 minutes to obtain mixed styrene-butadiene rubber; add the pretreated aramid fiber to the mixed styrene-butadiene rubber and mix at 75°C for 20 minutes to obtain a compound. Step c: Add 80g of sodium hexamethylenediamine carbamate, 45g of sodium dimethyl dithiocarbamate and 200g of carbon black to the compound, mix evenly, and vulcanize at 165℃ and 15MPa for 5min to obtain aramid fiber modified styrene-butadiene rubber.

[0062] Example 3 This embodiment provides a layered rubber material and its preparation method, specifically including the following: The layered rubber material comprises, from top to bottom, a puncture rubber layer, an antibacterial rubber layer, and a contact rubber layer; wherein, the puncture rubber layer comprises the following raw material components in parts by weight: 40 parts EPDM rubber, 15 parts hydrogenated styrene-butadiene block copolymer, 20 parts inorganic filler, 3 parts antioxidant MB, 2 parts stearic acid, and 3 parts sulfur and ethylene sulfur in a mass ratio of 1:2; wherein, the inorganic filler comprises titanium dioxide powder and phlogopite powder in a mass ratio of 1:3.5; The antibacterial rubber layer comprises the following raw material components in parts by weight: 40 parts of aramid fiber modified styrene-butadiene rubber, 15 parts of paeonol microcapsule modified isoprene rubber, 3 parts of antioxidant MB, 3 parts of stearic acid, and 3 parts of sulfur and ethylene sulfur in a mass ratio of 1:2.5. The contact rubber layer comprises the following raw material components in parts by weight: 40 parts butyl rubber, 5 parts chitosan, 5 parts antioxidant MB, 3 parts stearic acid, and 2 parts sulfur and ethylene thiourea in a mass ratio of 1:2.5.

[0063] The preparation method of the layered rubber material includes the following steps: Step 1: Weigh the raw materials of each component of the puncture rubber layer according to the design ratio, mix them evenly, vulcanize at 170℃ and 10MPa for 8 minutes, and extrude to obtain a puncture rubber layer material with a thickness of 540μm. Step 2: Weigh the raw materials of each component of the antibacterial rubber layer according to the design ratio, mix them evenly, vulcanize at 165℃ and 12MPa for 8 minutes, and extrude to obtain an antibacterial rubber layer material with a thickness of 390μm. Step 3: Weigh the raw materials of each component of the contact rubber layer according to the design ratio, mix them evenly, vulcanize at 175℃ and 13MPa for 6 minutes, and extrude to obtain a contact rubber layer material with a thickness of 600μm. Step 4: Stack the puncture rubber layer material, antibacterial rubber layer material and contact rubber layer material in sequence, and extrude them to obtain a layered rubber material.

[0064] The preparation method of the paeonol microcapsule-modified isoprene rubber includes the following steps: S1. Dissolve 30g of gum arabic in 800g of deionized water and heat to dissolve, obtaining a wall material solution; add 50g of an alcoholic solution of paeonol to the wall material solution and mix evenly to obtain a core-wall mixture; spray dry the core-wall mixture, setting the inlet air temperature to 90℃, the outlet air temperature to 80℃, the feed rate to 3mL / min, and the atomization pressure to 0.3MPa, to obtain paeonol microcapsules; S2. Mix 1 kg of isoprene rubber at 55°C for 8 min to obtain mixed rubber; add 50 g of the paeonol microcapsules to the mixed rubber and mix at 75°C for 12 min to obtain a mixed rubber. S3. Add 50g tetramethylthiuram disulfide, 30g zinc diethyldithiocarbamate and 100g carbon black to the mixed rubber, mix evenly, and vulcanize at 100℃ and 10MPa for 5min to obtain paeonol microcapsule modified isoprene rubber.

[0065] The preparation method of the aramid fiber modified styrene-butadiene rubber includes the following steps: Step a: Crush 200g of aramid fiber to obtain short aramid fiber with a length of 1mm; disperse the short aramid fiber in 800mL of acetone, filter, dry, and perform thermal oxidation treatment at 200℃ for 40min to obtain pretreated aramid fiber. Step b: Mix 3000g of styrene-butadiene rubber at 70°C for 12 minutes to obtain mixed styrene-butadiene rubber; add the pretreated aramid fiber to the mixed styrene-butadiene rubber and mix at 75°C for 20 minutes to obtain a compound. Step c: Add 80g of sodium hexamethylenediamine carbamate, 45g of sodium dimethyl dithiocarbamate and 200g of carbon black to the compound, mix evenly, and vulcanize at 165℃ and 15MPa for 5min to obtain aramid fiber modified styrene-butadiene rubber.

[0066] Comparative Example 1 This comparative example provides a layered rubber material, which differs from Example 1 in that the hydrogenated styrene-butadiene block copolymer is replaced with an equal amount of styrene-butadiene block copolymer, while other components and processes remain unchanged, and will not be described in detail here.

[0067] Comparative Example 2 This comparative example provides a layered rubber material, which differs from Example 1 in that the inorganic filler is replaced with an equal amount of attapulgite clay, while other components and processes remain unchanged, and will not be described in detail here.

[0068] Comparative Example 3 This comparative example provides a layered rubber material, which differs from Example 1 in that the aramid fiber modified styrene-butadiene rubber is replaced with an equal amount of styrene-butadiene rubber, while other components and processes remain unchanged, and will not be described in detail here.

[0069] Comparative Example 4 This comparative example provides a layered rubber material, which differs from Example 1 in that: the paeonol microcapsule modified isoprene rubber is replaced with an equal amount of chitosan quaternary ammonium salt modified isoprene rubber, while other components and processes remain unchanged, and will not be described in detail here.

[0070] The preparation method of the chitosan quaternary ammonium salt modified isoprene rubber includes the following steps: S1. Mix 1 kg of isoprene rubber at 55°C for 8 min to obtain mixed rubber; add 50 g of chitosan quaternary ammonium salt to the mixed rubber and mix at 75°C for 12 min to obtain mixed rubber. S2. Add 50g tetramethylthiuram disulfide, 30g zinc diethyldithiocarbamate and 100g carbon black to the mixed rubber, mix evenly, and vulcanize at 105℃ and 9MPa for 2h to obtain chitosan quaternary ammonium salt modified isoprene rubber.

[0071] To further demonstrate the technical effects of the present invention, the layered rubber materials obtained in Examples 1-3 and Comparative Examples 1-4 were tested as follows: According to the standard YBB00052005-2015, the rubber stoppers prepared in each example and comparative example were subjected to performance tests. The chemical performance tests included the detection of ammonium and zinc ions. The test solution was prepared according to the standard YBB00052005-2015 and then quantitatively tested to calculate the content of ammonium and zinc ions in the test solution. The rubber material was also tested for its antibacterial activity against Escherichia coli. The specific testing procedure was as follows: The rubber material was cleaned with sterile physiological saline, dried, and placed in a sterile culture dish. 1 mL of cultured Escherichia coli solution (concentration 10) was pipetted into the dish. 7CFU / mL was added around the rubber material, and the inoculated petri dishes were placed in a constant temperature incubator at 37℃. The growth of colonies on the surface of the rubber material was observed, the number of colonies was recorded, and the antibacterial effect of the rubber material was evaluated. The control group was a petri dish without rubber material. The formula for calculating the antibacterial rate was: Antibacterial rate (%) = (number of colonies in the control group - number of colonies in the experimental group) / number of colonies in the control group × 100%. The test results are shown in Table 1.

[0072] Table 1 Performance test results of various layered rubber materials

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A layered rubber material, characterized in that: The layered rubber material comprises, from top to bottom, a puncture rubber layer, an antibacterial rubber layer, and a contact rubber layer; wherein, the puncture rubber layer comprises the following raw material components in parts by weight: 40-50 parts of EPDM rubber, 10-15 parts of hydrogenated styrene-butadiene block copolymer, 10-20 parts of inorganic filler, 1-5 parts of antioxidant, 1-3 parts of activator, and 1-3 parts of vulcanization aid; wherein, the inorganic filler comprises titanium dioxide powder and phlogopite powder; The antibacterial rubber layer comprises the following raw material components in parts by weight: 30-50 parts of aramid fiber modified styrene-butadiene rubber, 15-20 parts of paeonol microcapsule modified isoprene rubber, 1-5 parts of antioxidant, 1-3 parts of activator and 1-3 parts of vulcanization aid. The contact rubber layer comprises the following raw material components in parts by weight: 40-60 parts butyl rubber, 1-5 parts chitosan, 1-5 parts antioxidant, 1-3 parts activator, and 1-3 parts vulcanization aid.

2. The layered rubber material as described in claim 1, characterized in that: The preparation method of the paeonol microcapsule modified isoprene rubber includes the following steps: S1. Dissolve the wall material in deionized water to obtain a wall material solution; add an alcoholic solution of paeonol to the wall material solution and mix well to obtain a core-wall mixture; spray dry the core-wall mixture to obtain paeonol microcapsules. S2. Isoprene rubber is subjected to intensive mixing at 50-60°C to obtain intensively mixed rubber; the paeonol microcapsules are added to the intensively mixed rubber and then mixed to obtain a mixed rubber. S3. Add vulcanizing agent, accelerator and reinforcing agent to the mixed rubber, mix evenly, and vulcanize at 100℃-110℃ to obtain paeonol microcapsule modified isoprene rubber.

3. The layered rubber material as described in claim 2, characterized in that: In S1, the wall material is gum arabic or gelatin; and / or In S1, the mass ratio of the wall material to the deionized water is 1:20-1:30; and / or In S1, the mass ratio of the paeonol alcohol solution to the wall material solution is 1:10-1:20; and / or In S1, the paeonol alcohol solution contains 60%-70% paeonol by mass.

4. The layered rubber material as described in claim 2, characterized in that: In S1, the inlet air temperature of the spray dryer is 90℃-100℃, the outlet air temperature is 80℃-90℃, the feed rate is 2mL / min-5mL / min; the atomization pressure is 0.2MPa-0.4MPa; and / or In S2, the mixing time is 5-10 minutes; and / or In S2, the mass ratio of the paeonol microcapsules to the isoprene rubber is 3:100-8:100; and / or In S2, the mixing temperature is 70℃-80℃, and the mixing time is 10min-15min.

5. The layered rubber material as described in claim 2, characterized in that: In S3, the amount of the vulcanizing agent added is 2%-3% of the mass of the mixed rubber; and / or In S3, the amount of the accelerator added is 1%-2% of the mass of the mixed adhesive; and / or In S3, the amount of reinforcing agent added is 5%-10% of the mass of the mixed adhesive; and / or In S3, the vulcanization time is 4 min-6 min, and the vulcanization pressure is 8 MPa-10 MPa.

6. The layered rubber material as described in claim 1, characterized in that: The preparation method of the aramid fiber modified styrene-butadiene rubber includes the following steps: Step a: Crush the aramid fiber to obtain short aramid fiber; disperse the short aramid fiber in a low-boiling-point organic solvent, filter, dry, and perform thermal oxidation treatment at 180℃-220℃ for 30min-50min to obtain pretreated aramid fiber, wherein the low-boiling-point organic solvent is acetone. Step b: Mix the styrene-butadiene rubber at 65℃-75℃ for 10min-15min to obtain mixed styrene-butadiene rubber; add the pretreated aramid fiber to the mixed styrene-butadiene rubber and mix at 60℃-85℃ for 20min-25min to obtain a compound. Step c: Add vulcanizing agent, accelerator and reinforcing agent to the compound, mix evenly, and vulcanize at 150℃-170℃ to obtain aramid fiber modified styrene-butadiene rubber.

7. The layered rubber material as described in claim 6, characterized in that: In step a, the length of the short aramid fiber is 0.5mm-1.5mm; and / or In step a, the mass-to-volume ratio of the short aramid fiber to the low-boiling-point organic solvent is 1g:3mL-1g:5mL; and / or In step b, the mass ratio of the pretreated aramid fiber to the styrene-butadiene rubber is 1:10-1:20; and / or In step c, the vulcanization pressure is 10MPa-20MPa, and the vulcanization time is 4min-8min.

8. The layered rubber material as described in claim 1, characterized in that: The inorganic filler comprises titanium dioxide powder and phlogopite powder in a mass ratio of 1:2 to 1:5; and / or The thickness of the puncture rubber layer is 450μm-800μm; and / or The thickness of the antibacterial rubber layer is 250μm-500μm; and / or The thickness of the contact rubber layer is 450μm-600μm.

9. A method for preparing a layered rubber material as described in any one of claims 1-8, characterized in that: Includes the following steps: Step 1: Weigh the raw materials of each component of the puncture rubber layer according to the design ratio, mix them evenly, vulcanize them at 160℃-180℃, and extrude them to obtain the puncture rubber layer material. Step 2: Weigh the raw materials of each component of the antibacterial rubber layer according to the design ratio, mix them evenly, vulcanize them at 160℃-180℃, and extrude them to obtain the antibacterial rubber layer material. Step 3: Weigh the raw materials of each component of the contact rubber layer according to the design ratio, mix them evenly, vulcanize them at 160℃-180℃, and extrude them to obtain the contact rubber layer material. Step 4: Stack the puncture rubber layer material, antibacterial rubber layer material and contact rubber layer material in sequence, and extrude them to obtain a layered rubber material.

10. The application of a layered rubber material as described in any one of claims 1-8 or a layered rubber material prepared by the method for preparing a layered rubber material as described in claim 9 in the field of preparing medical rubber stopper materials.

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