Elastic damping rubber with good shock absorption and noise reduction effects for elevator car

Abstract

The invention discloses elastic damping rubber with good shock absorption and noise reduction effects for an elevator car, and relates to the technical field of rubber, the elastic damping rubber comprises the following components: 50-75 parts of carboxylated ethylene propylene diene monomer rubber as matrix rubber for providing basic elasticity and crosslinkable sites, 15-30 parts of ionized polyisobutene for endowing the material with ionic conductivity and a unique ionic damping mechanism, the liquid crystal enhanced nano clay is used for enhancing mechanical strength and damping performance and improving dynamic mechanical behaviors at the same time. The polyisobutene main chain is grafted with the ionic liquid to form a dynamic network, low-frequency vibration energy is efficiently dissipated through ionic migration, the damping effect during starting and stopping of an elevator is remarkably improved, the high-temperature migration problem of a traditional plasticizer is avoided in a chemical grafting mode, and the long-term stability of the material is guaranteed; meanwhile, the instantaneous impact buffering capacity is enhanced through the synergistic effect of the ionic liquid and the carboxylated rubber.

Description

Technical Field

[0001] The invention relates to the technical field of rubber, in particular to an elastic damping rubber for an elevator car with good vibration and noise reduction effects. Background Art

[0002] Rubber is an elastic polymer. It can be obtained from the sap of certain plants or be man-made. Rubber is categorized by source and use into natural rubber and synthetic rubber. Synthetic rubber is further divided into general-purpose and specialty synthetic rubbers. Both types have numerous applications and products, such as tires and vibration-damping and noise-reducing pads for elevator cars.

[0003] The defects of existing elastic damping rubber are: 1. Patent document US5402861A discloses an elevator car and a device for evaluating elevator ride quality. However, the rubber structure used in the elevator car in the above document has technical problems such as poor shock absorption and poor impact buffering capacity. 2. Patent document JPS57195943A discloses vibration protection rubber for elevator doors. However, the vibration protection rubber in the above document has a technical problem of being unable to maintain temperature damping performance under high temperature conditions. 3. Patent document JP2001171955A discloses an elevator machine tool and a method for replacing a rubber vibration isolator on the machine. However, the rubber vibration isolation device in the above document suffers from a technical problem of being unable to achieve self-repair of local damage, resulting in a reduced service life. 4. Patent document CN206000915U discloses a composite shock-absorbing pad. However, the composite shock-absorbing pad in the above document has a technical problem of being unable to simultaneously maintain low-temperature flexibility. Summary of the Invention

[0004] The object of the present invention is to provide an elastic damping rubber with good vibration and noise reduction effects for an elevator car, so as to solve the technical problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: an elastic damping rubber with good vibration and noise reduction effect for an elevator car, comprising the following components in parts by weight: 50-75 parts of carboxylated EPDM rubber, as the base rubber, providing basic elasticity and cross-linkable sites; 15-30 parts of ionized polyisobutylene, which gives the material ionic conductivity and a unique ionic damping mechanism; 3-8 parts of liquid crystal enhanced nanoclay, used to enhance mechanical strength and damping performance, while improving dynamic mechanical behavior; 5 to 15 parts of multi-stage core-shell damping microspheres are used to broaden the effective damping temperature range and dissipate vibration energy; 1.5 to 4 parts of the multiple dynamic cross-linking system to provide adaptive network structure and energy dissipation pathways; 5-12 parts of topological plasticizer to optimize processing performance and dynamic mechanical properties; The ionized polyisobutylene is composed of a polyisobutylene main chain grafted with 1-butyl-3-methylimidazolium bromide, and the grafting rate of the ionic liquid is 5-10wt%.

[0006] Preferably, the carboxyl content of the carboxylated EPDM rubber is 0.8-1.8 mol%, the ethylene content is 58-65%, the Mooney viscosity is 45-75, and the propylene monomer unit accounts for ≤5 mol%.

[0007] Preferably, the preparation steps of the liquid crystal enhanced nanoclay are as follows: A1. Dispersing the organized montmorillonite in N-methylpyrrolidone solvent to form a stable suspension with a concentration of 8 to 12 wt%; A2. Adding a thermotropic liquid crystal polymer having a melting temperature of 225-245°C and a silane coupling agent KH-550 to the suspension, wherein the mass ratio of the thermotropic liquid crystal polymer to the organized montmorillonite is 1:3-4; A3, at a temperature of 90-110°C and a shear rate of 1500-2500S -1 The reaction is continued for 2.5 to 3.5 hours, so that the molecular chains of the thermotropic liquid crystal polymer are effectively inserted and anchored between the soil layers under the action of the shear force field and the coupling agent; A4. The reaction product is treated by a spray drying process to obtain a liquid crystal reinforced nanoclay composite with an interlayer spacing of 3.9 to 4.5 nm.

[0008] Preferably, the thermotropic liquid crystal polymer in S2 is specifically a copolyester of p-hydroxybenzoic acid and 2,6-naphthalene dicarboxylic acid, and has an intrinsic viscosity of 0.6 to 0.9 dL / g.

[0009] Preferably, the multi-stage core-shell damping microspheres include a three-layer structure: Core: Made of hollow microspheres composed of alumina and zirconia composite ceramics, with a particle size range of 35-45 μm, a wall thickness of 1.2-1.8 μm, and a compressive strength of ≥180 MPa; Middle layer: a polyurethane phase formed by 4,4'-diphenylmethane diisocyanate and polycaprolactone diol and a polyacrylate phase formed by butyl acrylate are in situ polymerized to form an interpenetrating polymer network layer with a thickness of 2.5 to 3.5 μm; Shell: A polydopamine deposition layer formed on the surface of the intermediate layer by dopamine self-polymerization reaction, with a thickness of 150 to 250 nm and a surface oxygen content of ≥15 at%.

[0010] Preferably, the multiple dynamic cross-linking system is composed of three cross-linking agents with different action mechanisms and dynamic properties: Diels-Alder crosslinker: 0.8-1.5 parts of maleimidized EPDM rubber, with a maleimide group content of 0.4-0.7 mol%; Ionic crosslinking agent: 0.4-0.7 parts of zinc methacrylate; Free radical crosslinking agent: 0.6 to 1.0 parts of 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane.

[0011] Preferably, the topological plasticizer is a hyperbranched polyester-polyolefin block copolymer, and its structural characteristics are: Polyolefin block: Ethylene-1-octene copolymer, density 0.865~0.880g / cm 3 ; Hyperbranched core: a hyperbranched polyester core with a generation number of G=4; Overall properties: hydroxyl value is 40-60 mg KOH / g.

[0012] Preferably, in the interpenetrating polymer network structure of the intermediate layer: The glass transition temperature of the polyurethane phase is -45 to -35°C; The glass transition temperature of the polyacrylate phase is -10 to 5°C; The glass transition temperature difference between the two phases is ≥40°C.

[0013] Preferably, the steps for preparing the elastic damping rubber with good vibration and noise reduction effect for the elevator car are as follows: S1. Raw material pretreatment: obtaining the prepared liquid crystal enhanced nanoclay, synthesized ionized polyisobutylene and constructed multi-level core-shell damping microspheres respectively; S2. Initial mixing: Add carboxylated EPDM rubber, ionized polyisobutylene and topological plasticizer into an internal mixer, raise the temperature in the internal mixer to 80°C, rotate the rotor at 40 rpm, and mix for 5 minutes to form a homogeneous mass; S3, mid-section enhancement: Increase the rotor speed to 60 rpm, add liquid crystal enhanced nanoclay and multi-level core-shell damping microspheres in batches, and control the temperature to ≤ 90 ° C. Mix for 8 minutes to avoid damage to the microsphere structure; S4, terminal dynamic crosslinking: reduce the rotor speed to 30 rpm, add the multiple dynamic crosslinking system, maleimidized EPDM, zinc methacrylate and 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, and mix at 70°C for 3 minutes to ensure uniform dispersion of the crosslinker; S5, dynamic vulcanization molding: step-by-step temperature-controlled vulcanization treatment in a flat vulcanizing press; The first stage: the vulcanization temperature is 120℃ and the vulcanization treatment time is 10min to activate the Diels-Alder crosslinker to form a reversible network; The second stage: the vulcanization temperature is 160℃ and the vulcanization treatment time is 15min, which triggers the free radical crosslinking agent to build a permanent network; The third stage: the vulcanization temperature is 115℃ and the vulcanization treatment time is 5min, which promotes the aggregation of ion clusters of the ionic crosslinker; And maintain a pressure of 15MPa throughout the vulcanization process; S6. Preparation: Curing at room temperature for 24 hours to stabilize the ion cross-linking network, and cutting into the required car shock-absorbing rubber gasket.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention forms a dynamic network by grafting ionic liquid onto a polyisobutylene backbone. This utilizes ion migration to efficiently dissipate low-frequency vibration energy, significantly improving the shock absorption effect during elevator start-up and shutdown. Chemical grafting avoids the high-temperature migration problem of traditional plasticizers, ensuring the long-term stability of the material. The synergistic effect of the ionic liquid and carboxylated rubber enhances the instantaneous impact cushioning capability. 2. This invention uses a ceramic core to provide rigid support to resist creep, a middle interpenetrating network layer to absorb vibrations over a wide temperature range using a dual-phase glass transition temperature difference, and a polydopamine shell to strengthen the interface and inhibit crack propagation, achieving full-band noise reduction from low-frequency car vibration to high-frequency motor noise while maintaining high impact toughness. 3. This invention uses thermotropic liquid crystal polymers to be directionally inserted between clay layers under a shear field, significantly increasing the interfacial contact area. This enhances the efficiency of high-frequency vibration dissipation through molecular chain friction. Combined with the reinforcing effect of nanoclay, this technology maintains stable damping performance even under high-temperature conditions. 4. This invention achieves autonomous repair of local damage through a reversible cross-linked network, ensures high-temperature strength through a permanent covalent network, and optimizes medium-temperature damping through ionic cross-linked clusters. These three elements work together to overcome the limitations of traditional materials in achieving both high damping and long life, thereby doubling fatigue life and extending service life. 5. This invention uses a hyperbranched core to anchor the nanofiller to prevent agglomeration, and the polyolefin block is compatible with the rubber matrix to inhibit migration. This improves filler dispersibility while maintaining low-temperature flexibility, resolving the contradiction between mechanical strength and processing performance of highly filled systems. 6. This invention activates different crosslinking mechanisms in stages: first, building a reversible network to retain dynamic bond activity, then forming a permanent covalent backbone, ultimately promoting the orderly aggregation of ion clusters. This sequential design avoids network conflicts, achieving synergistic optimization of damping performance and mechanical strength, making the material adaptable to year-round operating conditions from extremely cold to high temperatures. DETAILED DESCRIPTION

[0015] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0016] Example 1: An embodiment provided by the present invention: an elastic damping rubber with good vibration and noise reduction effect for an elevator car, comprising the following components in parts by weight: 65 parts of carboxylated EPDM rubber; 22 parts of ionized polyisobutylene; 6 parts of liquid crystal enhanced nanoclay; 10 parts of multi-stage core-shell damping microspheres; 3 parts of multiple dynamic cross-linking system; 9 parts of topological plasticizer; Among them, the ionized polyisobutylene is composed of a polyisobutylene backbone grafted with 1-butyl-3-methylimidazolium bromide, and the ionic liquid grafting rate is 8wt%; The carboxyl content of carboxylated EPDM rubber is 1.4 mol%, the ethylene content is 61%, the Mooney viscosity is 60, and the propylene monomer unit accounts for ≤5 mol%; The preparation steps of liquid crystal enhanced nanoclay are as follows: A1. Dispersing the organized montmorillonite in N-methylpyrrolidone solvent to form a stable suspension with a concentration of 10 wt%; A2. Adding a thermotropic liquid crystal polymer with a melting temperature of 235°C and a silane coupling agent KH-550 to the suspension, wherein the mass ratio of the thermotropic liquid crystal polymer to the organized montmorillonite is 1:3.5; A3, at a temperature of 100°C and a shear rate of 2000S -1 The reaction was continued for 3 hours, so that the molecular chains of the thermotropic liquid crystal polymer were effectively inserted and anchored between the soil layers under the action of the shear force field and the coupling agent. A4. The reaction product is treated by a spray drying process to obtain a liquid crystal reinforced nanoclay composite with an interlayer spacing of 4.2 nm; The thermotropic liquid crystal polymer in S2 is specifically a copolyester of p-hydroxybenzoic acid and 2,6-naphthalene dicarboxylic acid, and has an intrinsic viscosity of 0.8 dL / g; The multi-level core-shell damping microspheres consist of three layers: Core: Made of hollow microspheres composed of alumina and zirconia composite ceramics, with a particle size range of 40μm, a wall thickness of 1.5μm, and a compressive strength of ≥180MPa; Middle layer: A polyurethane phase formed by 4,4'-diphenylmethane diisocyanate and polycaprolactone diol and a polyacrylate phase formed by butyl acrylate are in situ polymerized to form an interpenetrating polymer network layer with a thickness of 3 μm; Shell: A polydopamine deposition layer formed on the surface of the intermediate layer by dopamine self-polymerization reaction, with a thickness of 200 nm and a surface oxygen content of ≥15 at; The multiple dynamic cross-linking system is composed of three cross-linking agents with different action mechanisms and dynamic properties: Diels-Alder crosslinker: 1.2 parts of maleimidized EPDM rubber with a maleimide group content of 0.6 mol%; Ionic crosslinking agent: 0.5 parts of zinc methacrylate; Free radical crosslinking agent: 0.8 parts of 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane; Topological plasticizer: It is a hyperbranched polyester-polyolefin block copolymer with the following structural characteristics: Polyolefin block: Ethylene-1-octene copolymer, density 0.870g / cm 3 ; Hyperbranched core: a hyperbranched polyester core with a generation number of G=4; Overall properties: hydroxyl value is 50mgKOH / g; In the interpenetrating polymer network structure of the middle layer: The glass transition temperature of the polyurethane phase is -40°C; The glass transition temperature of the polyacrylate phase is 0°C; The glass transition temperature difference between the two phases is 40°C; The preparation steps of the elastic damping rubber with good vibration and noise reduction effect for elevator cars are as follows: S1. Raw material pretreatment: obtaining the prepared liquid crystal enhanced nanoclay, synthesized ionized polyisobutylene and constructed multi-level core-shell damping microspheres respectively; S2. Initial mixing: Add carboxylated EPDM rubber, ionized polyisobutylene and topological plasticizer into an internal mixer, raise the temperature in the internal mixer to 80°C, rotate the rotor at 40 rpm, and mix for 5 minutes to form a homogeneous mass; S3, mid-section enhancement: Increase the rotor speed to 60 rpm, add liquid crystal enhanced nanoclay and multi-level core-shell damping microspheres in batches, and control the temperature to ≤ 90 ° C. Mix for 8 minutes to avoid damage to the microsphere structure; S4, terminal dynamic crosslinking: reduce the rotor speed to 30 rpm, add the multiple dynamic crosslinking system, maleimidized EPDM, zinc methacrylate and 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, and mix at 70°C for 3 minutes to ensure uniform dispersion of the crosslinker; S5, dynamic vulcanization molding: step-by-step temperature-controlled vulcanization treatment in a flat vulcanizing press; The first stage: the vulcanization temperature is 120℃ and the vulcanization treatment time is 10min to activate the Diels-Alder crosslinker to form a reversible network; The second stage: the vulcanization temperature is 160℃ and the vulcanization treatment time is 15min, which triggers the free radical crosslinking agent to build a permanent network; The third stage: the vulcanization temperature is 115℃ and the vulcanization treatment time is 5min, which promotes the aggregation of ion clusters of the ionic crosslinker; And maintain a pressure of 15MPa throughout the vulcanization process; S6. Preparation: Curing at room temperature for 24 hours to stabilize the ion cross-linking network, and cutting into the required car shock-absorbing rubber gasket.

[0017] Example 2: An embodiment provided by the present invention: an elastic damping rubber with good vibration and noise reduction effect for an elevator car, comprising the following components in parts by weight: 50 parts of carboxylated EPDM rubber; 30 parts of ionized polyisobutylene; 3 parts of liquid crystal enhanced nanoclay; 15 parts of multi-stage core-shell damping microspheres; 1.5 parts of multiple dynamic cross-linking system; 12 parts of topological plasticizer; Among them, the ionized polyisobutylene is composed of a polyisobutylene backbone grafted with 1-butyl-3-methylimidazolium bromide, and the ionic liquid grafting rate is 5wt%; The carboxyl content of carboxylated EPDM rubber is 1.8 mol%, the ethylene content is 58%, the Mooney viscosity is 75, and the propylene monomer unit accounts for ≤5 mol%; The preparation steps of liquid crystal enhanced nanoclay are as follows: A1. Dispersing the organized montmorillonite in N-methylpyrrolidone solvent to form a stable suspension with a concentration of 8 wt%; A2. Adding a thermotropic liquid crystal polymer with a melting temperature of 245°C and a silane coupling agent KH-550 to the suspension, wherein the mass ratio of the thermotropic liquid crystal polymer to the organized montmorillonite is 1:3; A3, at a temperature of 110°C and a shear rate of 1500s -1 The reaction was continued for 3.5 hours, so that the molecular chains of the thermotropic liquid crystal polymer were effectively inserted and anchored between the soil layers under the action of the shear force field and the coupling agent. A4. The reaction product was treated by spray drying to obtain a liquid crystal reinforced nanoclay composite with an interlayer spacing of 3.9 nm. The thermotropic liquid crystal polymer in S2 is specifically a copolyester of p-hydroxybenzoic acid and 2,6-naphthalene dicarboxylic acid, and has an intrinsic viscosity of 0.9 dL / g; The multi-level core-shell damping microspheres consist of three layers: Core: Made of hollow microspheres composed of alumina and zirconia composite ceramics, with a particle size range of 44μm, a wall thickness of 1.2μm, and a compressive strength of ≥180MPa; Middle layer: A polyurethane phase formed by 4,4'-diphenylmethane diisocyanate and polycaprolactone diol and a polyacrylate phase formed by butyl acrylate are in situ polymerized to form an interpenetrating polymer network layer with a thickness of 3.5 μm; Shell: A polydopamine deposition layer formed on the surface of the intermediate layer by dopamine self-polymerization reaction, with a thickness of 160nm and a surface oxygen content of ≥15at%; The multiple dynamic cross-linking system is composed of three cross-linking agents with different action mechanisms and dynamic properties: Diels-Alder crosslinker: 1.5 parts of maleimidized ethylene propylene rubber with a maleimide group content of 0.5 mol%; Ionic crosslinking agent: 0.7 parts of zinc methacrylate; Free radical crosslinking agent: 0.6-1.0 parts of 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane; Topological plasticizer: It is a hyperbranched polyester-polyolefin block copolymer with the following structural characteristics: Polyolefin block: Ethylene-1-octene copolymer, density 0.865 / cm 3 ; Hyperbranched core: a hyperbranched polyester core with a generation number of G=4; Overall properties: hydroxyl value 60 mg KOH / g; In the interpenetrating polymer network structure of the middle layer: The glass transition temperature of the polyurethane phase is -45°C; The glass transition temperature of the polyacrylate phase is 5°C; The glass transition temperature difference between the two phases is 50°C; The preparation steps of the elastic damping rubber with good vibration and noise reduction effect for elevator cars are as follows: S1. Raw material pretreatment: obtaining the prepared liquid crystal enhanced nanoclay, synthesized ionized polyisobutylene and constructed multi-level core-shell damping microspheres respectively; S2. Initial mixing: Add carboxylated EPDM rubber, ionized polyisobutylene and topological plasticizer into an internal mixer, raise the temperature in the internal mixer to 80°C, rotate the rotor at 40 rpm, and mix for 5 minutes to form a homogeneous mass; S3, mid-section enhancement: Increase the rotor speed to 60 rpm, add liquid crystal enhanced nanoclay and multi-level core-shell damping microspheres in batches, and control the temperature to ≤ 90 ° C. Mix for 8 minutes to avoid damage to the microsphere structure; S4, terminal dynamic crosslinking: reduce the rotor speed to 30 rpm, add the multiple dynamic crosslinking system, maleimidized EPDM, zinc methacrylate and 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, and mix at 70°C for 3 minutes to ensure uniform dispersion of the crosslinker; S5, dynamic vulcanization molding: step-by-step temperature-controlled vulcanization treatment in a flat vulcanizing press; The first stage: the vulcanization temperature is 120℃ and the vulcanization treatment time is 10min to activate the Diels-Alder crosslinker to form a reversible network; The second stage: the vulcanization temperature is 160℃ and the vulcanization treatment time is 15min, which triggers the free radical crosslinking agent to build a permanent network; The third stage: the vulcanization temperature is 115℃ and the vulcanization treatment time is 5min, which promotes the aggregation of ion clusters of the ionic crosslinker; And maintain a pressure of 15MPa throughout the vulcanization process; S6. Preparation: Curing at room temperature for 24 hours to stabilize the ion cross-linking network, and cutting into the required car shock-absorbing rubber gasket.

[0018] Example 3: An embodiment provided by the present invention: an elastic damping rubber with good vibration and noise reduction effect for an elevator car, comprising the following components in parts by weight: 75 parts of carboxylated EPDM rubber; 15 parts of ionized polyisobutylene; 8 parts of liquid crystal enhanced nanoclay; 5 parts of multi-stage core-shell damping microspheres; 4 parts of multiple dynamic cross-linking system; 5 parts of topological plasticizer; The ionized polyisobutylene is composed of a polyisobutylene backbone grafted with 1-butyl-3-methylimidazolium bromide, and the ionic liquid grafting rate is 10 wt %. The carboxyl content of carboxylated EPDM rubber is 0.8 mol%, the ethylene content is 65%, the Mooney viscosity is 45, and the propylene monomer unit accounts for ≤5 mol%; The preparation steps of liquid crystal enhanced nanoclay are as follows: A1. Dispersing the organized montmorillonite in N-methylpyrrolidone solvent to form a stable suspension with a concentration of 12 wt%; A2. Adding a thermotropic liquid crystal polymer with a melting temperature of 225°C and a silane coupling agent KH-550 to the suspension, wherein the mass ratio of the thermotropic liquid crystal polymer to the organized montmorillonite is 1:4; A3, at a temperature of 90°C and a shear rate of 2500s -1 The reaction was continued for 2.5 hours, so that the molecular chains of the thermotropic liquid crystal polymer were effectively inserted and anchored between the soil layers under the action of the shear force field and the coupling agent. A4. The reaction product is treated by a spray drying process to obtain a liquid crystal reinforced nanoclay composite with an interlayer spacing of 4.5 nm; The thermotropic liquid crystal polymer in S2 is specifically a copolyester of p-hydroxybenzoic acid and 2,6-naphthalene dicarboxylic acid, and has an intrinsic viscosity of 0.6 dL / g; The multi-level core-shell damping microspheres consist of three layers: Core: Made of hollow microspheres composed of alumina and zirconia composite ceramics, with a particle size range of 45μm, a wall thickness of 1.2μm, and a compressive strength of ≥180MPa; Middle layer: A polyurethane phase formed by 4,4'-diphenylmethane diisocyanate and polycaprolactone diol and a polyacrylate phase formed by butyl acrylate are in situ polymerized to form an interpenetrating polymer network layer with a thickness of 3.5 μm; Shell: A polydopamine deposition layer formed on the surface of the intermediate layer by dopamine self-polymerization reaction, with a thickness of 150 nm and a surface oxygen content of ≥15 at; The multiple dynamic cross-linking system is composed of three cross-linking agents with different action mechanisms and dynamic properties: Diels-Alder crosslinker: 1.5 parts of maleimidized ethylene propylene rubber with a maleimide group content of 0.4 mol%; Ionic crosslinking agent: 0.4 parts of zinc methacrylate; Free radical crosslinking agent: 1.0 part of 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane; Topological plasticizer: It is a hyperbranched polyester-polyolefin block copolymer with the following structural characteristics: Polyolefin block: Ethylene-1-octene copolymer, density 0.880g / cm 3 ; Hyperbranched core: a hyperbranched polyester core with a generation number of G=4; Overall properties: hydroxyl value 40 mg KOH / g; In the interpenetrating polymer network structure of the middle layer: The glass transition temperature of the polyurethane phase is -35°C; The glass transition temperature of the polyacrylate phase is 5°C; The glass transition temperature difference between the two phases is 40°C; The preparation steps of the elastic damping rubber with good vibration and noise reduction effect for elevator cars are as follows: S1. Raw material pretreatment: obtaining the prepared liquid crystal enhanced nanoclay, synthesized ionized polyisobutylene and constructed multi-level core-shell damping microspheres respectively; S2. Initial mixing: Add carboxylated EPDM rubber, ionized polyisobutylene and topological plasticizer into an internal mixer, raise the temperature in the internal mixer to 80°C, rotate the rotor at 40 rpm, and mix for 5 minutes to form a homogeneous mass; S3, mid-section enhancement: Increase the rotor speed to 60 rpm, add liquid crystal enhanced nanoclay and multi-level core-shell damping microspheres in batches, and control the temperature to ≤ 90 ° C. Mix for 8 minutes to avoid damage to the microsphere structure; S4, terminal dynamic crosslinking: reduce the rotor speed to 30 rpm, add the multiple dynamic crosslinking system, maleimidized EPDM, zinc methacrylate and 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, and mix at 70°C for 3 minutes to ensure uniform dispersion of the crosslinker; S5, dynamic vulcanization molding: step-by-step temperature-controlled vulcanization treatment in a flat vulcanizing press; The first stage: the vulcanization temperature is 120℃ and the vulcanization treatment time is 10min to activate the Diels-Alder crosslinker to form a reversible network; The second stage: the vulcanization temperature is 160℃ and the vulcanization treatment time is 15min, which triggers the free radical crosslinking agent to build a permanent network; The third stage: the vulcanization temperature is 115℃ and the vulcanization treatment time is 5min, which promotes the aggregation of ion clusters of the ionic crosslinker; And maintain a pressure of 15MPa throughout the vulcanization process; S6. Preparation: Curing at room temperature for 24 hours to stabilize the ion cross-linking network, and cutting into the required car shock-absorbing rubber gasket.

[0019] Example 4: An embodiment provided by the present invention: an elastic damping rubber with good vibration and noise reduction effect for an elevator car, comprising the following components in parts by weight: 72 parts of carboxylated EPDM rubber; 17 parts of ionized polyisobutylene; 7 parts of liquid crystal enhanced nanoclay; 14 parts of multi-stage core-shell damping microspheres; 2 parts of multiple dynamic cross-linking system; 6 parts of topological plasticizer; Among them, the ionized polyisobutylene is composed of a polyisobutylene backbone grafted with 1-butyl-3-methylimidazolium bromide, and the ionic liquid grafting rate is 7wt%; The carboxyl content of carboxylated EPDM rubber is 0.9 mol%, ethylene content is 60%, Mooney viscosity is 70, and the proportion of propylene monomer units is ≤5 mol%; The preparation steps of liquid crystal enhanced nanoclay are as follows: A1. Dispersing the organized montmorillonite in N-methylpyrrolidone solvent to form a stable suspension with a concentration of 11 wt%; A2. Adding a thermotropic liquid crystal polymer with a melting temperature of 230°C and a silane coupling agent KH-550 to the suspension, wherein the mass ratio of the thermotropic liquid crystal polymer to the organized montmorillonite is 1:3; A3, at a temperature of 95°C and a shear rate of 1750s -1 The reaction was continued for 2.8 hours, so that the molecular chains of the thermotropic liquid crystal polymer were effectively inserted and anchored between the soil layers under the action of the shear force field and the coupling agent. A4. The reaction product was treated by spray drying to obtain a liquid crystal reinforced nanoclay composite with an interlayer spacing of 3.9 nm. The thermotropic liquid crystal polymer in S2 is specifically a copolyester of p-hydroxybenzoic acid and 2,6-naphthalene dicarboxylic acid, and has an intrinsic viscosity of 0.8 dL / g; The multi-level core-shell damping microspheres consist of three layers: Core: Made of hollow microspheres composed of alumina and zirconia composite ceramics, with a particle size range of 38μm, a wall thickness of 1.4μm, and a compressive strength of ≥180MPa; Middle layer: A polyurethane phase formed by 4,4'-diphenylmethane diisocyanate and polycaprolactone diol and a polyacrylate phase formed by butyl acrylate are in situ polymerized to form an interpenetrating polymer network layer with a thickness of 2.8 μm; Shell: A polydopamine deposition layer formed on the surface of the intermediate layer by dopamine self-polymerization reaction, with a thickness of 170nm and a surface oxygen content of ≥15at%; The multiple dynamic cross-linking system is composed of three cross-linking agents with different action mechanisms and dynamic properties: Diels-Alder crosslinker: 1.2 parts of maleimidized EPDM rubber with a maleimide group content of 0.6 mol%; Ionic crosslinking agent: 0.4 parts of zinc methacrylate; Free radical crosslinking agent: 0.9 parts of 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane; Topological plasticizer: It is a hyperbranched polyester-polyolefin block copolymer with the following structural characteristics: Polyolefin block: Ethylene-1-octene copolymer, density 0.875g / cm 3 ; Hyperbranched core: a hyperbranched polyester core with a generation number of G=4; Overall properties: hydroxyl value 55 mg KOH / g; In the interpenetrating polymer network structure of the middle layer: The glass transition temperature of the polyurethane phase is -40°C; The glass transition temperature of the polyacrylate phase is 5°C; The glass transition temperature difference between the two phases is 45°C; The preparation steps of the elastic damping rubber with good vibration and noise reduction effect for elevator cars are as follows: S1. Raw material pretreatment: obtaining the prepared liquid crystal enhanced nanoclay, synthesized ionized polyisobutylene and constructed multi-level core-shell damping microspheres respectively; S2. Initial mixing: Add carboxylated EPDM rubber, ionized polyisobutylene and topological plasticizer into an internal mixer, raise the temperature in the internal mixer to 80°C, rotate the rotor at 40 rpm, and mix for 5 minutes to form a homogeneous mass; S3, mid-section enhancement: Increase the rotor speed to 60 rpm, add liquid crystal enhanced nanoclay and multi-level core-shell damping microspheres in batches, and control the temperature to ≤ 90 ° C. Mix for 8 minutes to avoid damage to the microsphere structure; S4, terminal dynamic crosslinking: reduce the rotor speed to 30 rpm, add the multiple dynamic crosslinking system, maleimidized EPDM, zinc methacrylate and 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, and mix at 70°C for 3 minutes to ensure uniform dispersion of the crosslinker; S5, dynamic vulcanization molding: step-by-step temperature-controlled vulcanization treatment in a flat vulcanizing press; The first stage: the vulcanization temperature is 120℃ and the vulcanization treatment time is 10min to activate the Diels-Alder crosslinker to form a reversible network; The second stage: the vulcanization temperature is 160℃ and the vulcanization treatment time is 15min, which triggers the free radical crosslinking agent to build a permanent network; The third stage: the vulcanization temperature is 115℃ and the vulcanization treatment time is 5min, which promotes the aggregation of ion clusters of the ionic crosslinker; And maintain a pressure of 15MPa throughout the vulcanization process; S6. Preparation: Aging at room temperature for 24 hours to stabilize the ion cross-linking network, and cutting into the required elevator car shock-absorbing rubber gasket.

[0020] Comparative Example 1: prepared by referring to the method of Example 1, except that ionized polyisobutylene was eliminated and replaced with an equal amount of ordinary polyisobutylene. Other raw materials, steps and parameters were the same as those in Example 1.

[0021] Comparative Example 2: prepared by referring to the method of Example 1, the difference from Example 1 is that no liquid crystal enhanced nanoclay is added, and other raw materials, steps and parameters are the same as those of Example 1.

[0022] Comparative Example 3: prepared by referring to the method of Example 1, the difference from Example 1 is that the multi-stage core-shell damping microspheres are eliminated and replaced with an equal amount of single ceramic microspheres. Other raw materials, steps and parameters are the same as those in Example 1.

[0023] Comparative Example 4: prepared according to the method of Example 1, the difference from Example 1 is that: the multiple dynamic cross-linking system is simplified, only the free radical cross-linking agent is retained, and the Diels-Alder cross-linking agent and the ionic cross-linking agent are eliminated. Other raw materials, steps and parameters are the same as those in Example 1.

[0024] Comparative Example 5: prepared by referring to the method of Example 1, the difference from Example 1 is that the topological plasticizer is eliminated and replaced with an equal amount of linear dioctyl phthalate, and the other raw materials, steps and parameters are the same as those in Example 1.

[0025] Comparative Example 6: prepared by referring to the method of Example 1, the difference from Example 1 is that the vulcanization process is changed to a full-stage vulcanization temperature of 150°C, a vulcanization treatment time of 30 minutes, and other raw materials, steps and parameters are the same as those in Example 1.

[0026] Performance testing: Test 1, tensile properties test, the car shock-absorbing rubber gaskets obtained in Examples 1-4 and Comparative Examples 1-6 were tested using a universal material testing machine with a tensile rate of 500 mm / min, and the breaking strength, elongation at break and 100% modulus of elongation were recorded.

[0027] Test 2, damping performance test, the car shock-absorbing rubber gaskets obtained in Examples 1-4 and Comparative Examples 1-6 were tested using a dynamic thermomechanical analyzer with a frequency of 10 Hz, a temperature range of -40 to 80 ° C, and a heating rate of 3 ° C / min, and the tan δ peak value and the corresponding temperature were recorded.

[0028] Test 3: Dynamic fatigue test: The car shock-absorbing rubber gaskets obtained in Examples 1-4 and Comparative Examples 1-6 were tested using a dynamic fatigue testing machine with a strain amplitude of 50%, a frequency of 5 Hz, and 500,000 cycles, and the strength retention rate was recorded.

[0029] Test 4: Drop hammer impact test: The car shock-absorbing rubber gaskets obtained in Examples 1-4 and Comparative Examples 1-6 were tested using a drop hammer impact tester with a hammer weight of 5 kg and a height of 1 m. The maximum impact force and the absorption rate were recorded.

[0030] Test 5, actual working condition simulation test, the car shock-absorbing rubber gaskets obtained in Examples 1-4 and Comparative Examples 1-6 were tested by using an elevator car vibration table to simulate a 1.5m / s 2Acceleration vibration, measuring vibration transmissibility and noise attenuation value.

[0031] Table 1. Tensile performance test data

[0032]

[0033] Table 2. Damping performance test data

[0034] Table 3. Dynamic fatigue and impact performance test data

[0035]

[0036] Table 4. Actual working condition simulation performance test data

[0037] Furthermore, by grafting ionic liquid onto the polyisobutylene backbone to form a dynamic network, ion migration is used to efficiently dissipate low-frequency vibration energy, significantly improving the shock absorption effect during elevator start-up and shutdown. Chemical grafting avoids the high-temperature migration problem of traditional plasticizers, ensuring the long-term stability of the material. At the same time, the synergistic effect of ionic liquid and carboxylated rubber enhances the instantaneous impact cushioning capacity. The ceramic core provides rigid support to resist creep, the interpenetrating network layer in the middle utilizes the dual-phase glass transition temperature difference to cover a wide temperature range of vibration absorption, and the polydopamine shell strengthens the interface bonding to inhibit crack propagation, achieving full-band noise reduction from low-frequency car vibration to high-frequency motor noise while maintaining high impact toughness. By inserting thermotropic liquid crystal polymers into the clay layers in a shear field, the interfacial contact area is greatly increased. The high-frequency vibration dissipation efficiency is enhanced through molecular chain friction. Combined with the reinforcing effect of nanoclay, stable damping performance is maintained under high temperature conditions. The reversible cross-linking network enables autonomous repair of local damage, the permanent covalent network ensures high-temperature strength, and the ion-crosslinked clusters optimize medium-temperature damping. These three elements work together to overcome the limitations of traditional materials that cannot achieve both high damping and long life, and double the fatigue life. The hyperbranched core anchors the nanofiller to prevent agglomeration, and the polyolefin block is compatible with the rubber matrix to inhibit migration, improving filler dispersion while maintaining low-temperature flexibility, thus resolving the contradiction between mechanical strength and processing performance of highly filled systems. By activating different crosslinking mechanisms in stages—first building a reversible network to retain dynamic bond activity, then forming a permanent covalent backbone, and ultimately promoting the orderly aggregation of ion clusters—this sequential design avoids network conflicts and achieves synergistic optimization of damping performance and mechanical strength, enabling the material to adapt to year-round operating conditions from extremely cold to high temperatures.

[0038] Working principle: a dynamic network is formed by grafting ionic liquids onto the polyisobutylene main chain, and ion migration is used to efficiently dissipate low-frequency vibration energy, significantly improving the shock absorption effect when the elevator starts and stops. The problem of high-temperature migration of traditional plasticizers is avoided through chemical grafting, ensuring the long-term stability of the material. At the same time, the synergistic effect of ionic liquids and carboxylated rubber enhances the instantaneous impact buffering capacity, and the ceramic core provides rigid support to resist creep. The middle interpenetrating network layer uses the two-phase glass transition temperature difference to cover a wide temperature range of vibration absorption. The polydopamine shell strengthens the interface bonding to inhibit crack propagation, achieving full-band noise reduction from low-frequency car vibration to high-frequency motor noise, while maintaining high impact toughness. The thermotropic liquid crystal polymer is directionally inserted into the clay layer under the shear field to greatly increase the interface contact area. Molecular chain friction enhances high-frequency vibration dissipation efficiency, while nanoclay reinforcement maintains stable damping performance even under high-temperature conditions. A reversible crosslinking network enables autonomous repair of localized damage, a permanent covalent network ensures high-temperature strength, and ionic crosslinked clusters optimize damping at medium temperatures. These three elements work together to overcome the traditional material's "high damping and long life" trade-off, resulting in exponentially increased fatigue life. A hyperbranched core anchors the nanofiller to prevent agglomeration, while the polyolefin block is compatible with the rubber matrix and inhibits migration, improving filler dispersion while maintaining low-temperature flexibility. This addresses the conflict between mechanical strength and processability in highly filled systems. The system activates different crosslinking mechanisms in stages: first, a reversible network is constructed to preserve dynamic bond activity, then a permanent covalent backbone is formed, ultimately promoting the orderly aggregation of ionic clusters. This sequential design avoids network conflicts, achieving synergistic optimization of damping performance and mechanical strength, making the material suitable for year-round operating conditions from extreme cold to high temperatures.

[0039] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. An elastic damping rubber with good vibration and noise reduction effect for an elevator car, characterized by: Calculated by weight, it includes the following components: 50-75 parts of carboxylated EPDM rubber; 15-30 parts of ionized polyisobutylene; 3-8 parts of liquid crystal enhanced nanoclay; 5-15 parts of multi-stage core-shell damping microspheres; Multiple dynamic cross-linking system 1.5-4 parts; 5-12 parts of topological plasticizer; The ionized polyisobutylene is composed of a polyisobutylene main chain grafted with 1-butyl-3-methylimidazolium bromide, and the grafting rate of the ionic liquid is 5-10wt%.

2. The elastic damping rubber with good vibration and noise reduction effect for an elevator car according to claim 1, characterized in that: The carboxyl content of the carboxylated EPDM rubber is 0.8-1.8 mol%, the ethylene content is 58-65%, the Mooney viscosity is 45-75, and the propylene monomer unit accounts for ≤5 mol%.

3. The elastic damping rubber with good vibration and noise reduction effect for an elevator car according to claim 1, characterized in that: The preparation steps of the liquid crystal enhanced nanoclay are as follows: A1. Dispersing the organized montmorillonite in N-methylpyrrolidone solvent to form a stable suspension with a concentration of 8 to 12 wt%; A2. Adding a thermotropic liquid crystal polymer having a melting temperature of 225-245°C and a silane coupling agent KH-550 to the suspension, wherein the mass ratio of the thermotropic liquid crystal polymer to the organized montmorillonite is 1:3-4; A3, at a temperature of 90-110°C and a shear rate of 1500-2500S -1 The reaction is continued for 2.5 to 3.5 hours, so that the molecular chains of the thermotropic liquid crystal polymer are effectively inserted and anchored between the soil layers under the action of the shear force field and the coupling agent; A4. The reaction product is treated by a spray drying process to obtain a liquid crystal reinforced nanoclay composite with an interlayer spacing of 3.9 to 4.5 nm.

4. The elastic damping rubber with good vibration and noise reduction effect for an elevator car according to claim 3, characterized in that: The thermotropic liquid crystal polymer in S2 is specifically a copolyester of p-hydroxybenzoic acid and 2,6-naphthalene dicarboxylic acid, and has an intrinsic viscosity of 0.6 to 0.9 dL / g.

5. The elastic damping rubber with good vibration and noise reduction effect for an elevator car according to claim 1, characterized in that: The multi-level core-shell damping microspheres include a three-layer structure: Core: Made of hollow microspheres composed of alumina and zirconia composite ceramics, with a particle size range of 35-45 μm, a wall thickness of 1.2-1.8 μm, and a compressive strength of ≥180 MPa; Middle layer: a polyurethane phase formed by 4,4'-diphenylmethane diisocyanate and polycaprolactone diol and a polyacrylate phase formed by butyl acrylate are in situ polymerized to form an interpenetrating polymer network layer with a thickness of 2.5 to 3.5 μm; Shell: A polydopamine deposition layer formed on the surface of the intermediate layer by dopamine self-polymerization reaction, with a thickness of 150 to 250 nm and a surface oxygen content of ≥15 at%.

6. The elastic damping rubber with good vibration and noise reduction effect for an elevator car according to claim 1, characterized in that: The multiple dynamic cross-linking system is composed of three cross-linking agents with different action mechanisms and dynamic properties: Diels-Alder crosslinker: 0.8-1.5 parts of maleimidized EPDM rubber, with a maleimide group content of 0.4-0.7 mol%; Ionic crosslinking agent: 0.4-0.7 parts of zinc methacrylate; Free radical crosslinking agent: 0.6 to 1.0 parts of 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane.

7. The elastic damping rubber with good vibration and noise reduction effect for an elevator car according to claim 1, characterized in that: The topological plasticizer is a hyperbranched polyester-polyolefin block copolymer, and its structural characteristics are: Polyolefin block: Ethylene-1-octene copolymer, density 0.865~0.880g / cm 3 ; Hyperbranched core: a hyperbranched polyester core with a generation number of G=4; Overall properties: hydroxyl value is 40-60 mg KOH / g.

8. The elastic damping rubber with good vibration and noise reduction effect for an elevator car according to claim 5, characterized in that: In the interpenetrating polymer network structure of the intermediate layer: The glass transition temperature of the polyurethane phase is -45 to -35°C; The glass transition temperature of the polyacrylate phase is -10 to 5°C; The glass transition temperature difference between the two phases is ≥40°C.

9. A method for preparing elastic damping rubber with good vibration and noise reduction effects for elevator cars according to any one of claims 1 to 8, characterized in that: The steps for preparing the elastic damping rubber with good vibration and noise reduction effect for elevator cars are as follows: S1. Raw material pretreatment: obtaining the prepared liquid crystal enhanced nanoclay, synthesized ionized polyisobutylene and constructed multi-level core-shell damping microspheres respectively; S2. Initial mixing: Add carboxylated EPDM rubber, ionized polyisobutylene and topological plasticizer into an internal mixer, raise the temperature in the internal mixer to 80°C, rotate the rotor at 40 rpm, and mix for 5 minutes to form a homogeneous mass; S3, mid-section enhancement: Increase the rotor speed to 60 rpm, add liquid crystal enhanced nanoclay and multi-level core-shell damping microspheres in batches, and control the temperature to ≤ 90 ° C. Mix for 8 minutes to avoid damage to the microsphere structure; S4, terminal dynamic crosslinking: reduce the rotor speed to 30 rpm, add the multiple dynamic crosslinking system, maleimidized EPDM, zinc methacrylate and 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, and mix at 70°C for 3 minutes to ensure uniform dispersion of the crosslinker; S5, dynamic vulcanization molding: step-by-step temperature-controlled vulcanization treatment in a flat vulcanizing press; The first stage: the vulcanization temperature is 120℃ and the vulcanization treatment time is 10min to activate the Diels-Alder crosslinker to form a reversible network; The second stage: the vulcanization temperature is 160℃ and the vulcanization treatment time is 15min, which triggers the free radical crosslinking agent to build a permanent network; The third stage: the vulcanization temperature is 115℃ and the vulcanization treatment time is 5min, which promotes the aggregation of ion clusters of the ionic crosslinker; And maintain a pressure of 15MPa throughout the vulcanization process; S6. Preparation: Curing at room temperature for 24 hours to stabilize the ion cross-linking network, and cutting into the required car shock-absorbing rubber gasket.

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