A high-resilience automobile cushion filling material, a preparation method and an automobile cushion

Abstract

The application relates to the technical field of high polymer materials, and particularly discloses a high-rebound automobile seat cushion filling material, a preparation method and an automobile seat cushion. Ethylene-1-octene copolymer (POE), polypropylene (PP), ethylene-vinyl acetate copolymer (EVA), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), a nano dispersing agent, an antioxidant and a foaming agent are used as raw materials, and the automobile seat cushion filling material is prepared through melt blending and kettle pressure foaming. The elastic synergy of the ethylene-1-octene copolymer (POE) and the hydrogenated styrene-butadiene-styrene block copolymer (SEBS), the interface compatibilization of the ethylene-vinyl acetate copolymer (EVA) and the refinement of cell pores of the nano dispersing agent are combined to construct a uniform foaming structure; the antioxidant improves the aging resistance, so that the material has high compression rebound rate, low compression permanent deformation and excellent fatigue resistance. The automobile seat cushion filling material can realize rapid rebound and long-term non-collapsing, and can provide a long-lasting comfortable experience.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a high-resilience car seat cushion filling material, its preparation method, and the car seat cushion itself. Background Technology

[0002] With the development of the automotive industry and the upgrading of consumption, people's requirements for car ride comfort are increasing. As an important component that comes into direct contact with the human body, the performance of the filling material of car seat cushions is crucial. Excellent seat cushion materials must simultaneously possess characteristics such as high resilience, low compression set, sufficient mechanical strength, and environmental recyclability.

[0003] Currently, polyurethane foam (PUFoam) is the most widely used filling material for car seats due to its high resilience and good comfort. However, PUFoam has significant drawbacks: First, its raw material contains isocyanates, and the production process involves complex chemical reactions, requiring high levels of process control; second, the product is not recyclable and causes environmental pollution after disposal, which contradicts the current green and sustainable development concept of the automotive industry; third, it is prone to hydrolysis and aging after long-term use, and its durability sometimes fails to meet stringent automotive application standards.

[0004] To address the environmental concerns surrounding polyurethane foam, polyolefin foam materials are considered ideal alternatives due to their excellent recyclability, lightweight, and non-toxic / odorless properties. However, it is well known to those skilled in the art that pure polyolefins suffer from insufficient elasticity despite their high rigidity, resulting in generally low resilience in foamed products that fail to meet the requirements for high-resilience seat cushions. While conventional polyolefin elastomers can improve elasticity, their low strength and poor melt strength make it difficult to stabilize the cell structure during foaming, leading to cell collapse and coalescence. Ultimately, this results in decreased mechanical properties and increased compression set in the foamed products, similarly failing to meet the durability requirements of automotive seat cushions. Summary of the Invention

[0005] The purpose of this invention is to provide a high-resilience automotive seat cushion filling material, a preparation method, and an automotive seat cushion to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A high-resilience car seat cushion filling material, composed of the following components in parts by weight: 45-55 parts ethylene-1-octene copolymer (POE); 15-25 parts polypropylene (PP); 10-20 parts ethylene-vinyl acetate copolymer (EVA); 5-15 parts hydrogenated styrene-butadiene-styrene block copolymer (SEBS); 5-10 parts talc; 2-4 parts azodicarbonamide; 0.5-1.0 parts dicumyl peroxide; 1-2 parts zinc oxide; 0.5-1.5 parts zinc stearate; 0.1-0.5 parts antioxidant 1010; 0.1-0.5 parts antioxidant 168.

[0007] Preferably, the amount of ethylene-1-octene copolymer (POE) used is 50-55 parts.

[0008] Preferably, the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1.

[0009] Preferably, the vinyl acetate (VA) content in the ethylene-vinyl acetate copolymer (EVA) is 18%-28% by mass.

[0010] Preferably, the styrene / ethylene-butene mass ratio of the hydrogenated styrene-butadiene-styrene block copolymer (SEBS) is 30 / 70.

[0011] Preferably, the talc powder has a particle size of 3000-5000 mesh.

[0012] Secondly, the present invention provides a method for preparing the high-resilience automotive seat cushion filling material, comprising the following steps: S1. Weigh each component according to the stated weight ratio; S2. Add POE, PP, EVA, SEBS, talc, zinc stearate and antioxidant to a mixer and mix at 90-110℃ for 5-10 minutes; S3. Add azodicarbonamide, dicumyl peroxide and zinc oxide to the mixture obtained in step S2, and continue to mix for 3-5 minutes; S4. Transfer the mixture obtained in step S3 to a two-roll mill, and pass it through and sheet it at 100-120°C to obtain a sheet material; S5. After cutting the sheet obtained in step S4, place it into the mold and perform molding foaming on a hot press. The foaming temperature is 160-180℃, the pressure is 10-20MPa, and the time is 8-15 minutes. S6. After demolding the foamed product obtained in step S5, cure it at 70-90℃ for 6-10 hours to obtain the high-resilience car seat cushion filling material.

[0013] Preferably, in step S1, the azodicarbonamide is premixed with a portion of the ethylene-1-octene copolymer (POE) to form a pre-dispersion before being fed into the internal mixer.

[0014] Preferably, the pressure of the molding foaming in step S5 is 15-20 MPa.

[0015] Thirdly, the present invention provides an automobile seat cushion, wherein the filling core layer is made of the high-resilience automobile seat cushion filling material as described in any one of the first aspects, or is made of the high-resilience automobile seat cushion filling material prepared by any one of the preparation methods in the second aspect.

[0016] Preferably, the car seat cushion also includes a surface fabric or leather cover.

[0017] Compared with the prior art, the beneficial effects of the present invention are: (1) Through the synergistic effect of ethylene-1-octene copolymer (POE), ethylene-vinyl acetate copolymer (EVA) and hydrogenated styrene-butadiene-styrene block copolymer (SEBS), the compression resilience of the filler material is improved. At the same time, the physical cross-linking network of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) improves the fatigue resistance of the filler material. After 100,000 compression cycles, the material can still maintain extremely high resilience and compression set is effectively controlled, solving the problems of insufficient resilience and easy permanent deformation of traditional polyolefin materials.

[0018] (2) The addition of polypropylene (PP) provides good rigid support, while hydrogenated styrene-butadiene-styrene block copolymer (SEBS) and ethylene-vinyl acetate copolymer (EVA) significantly improve the toughness of the material. The resulting material maintains high resilience while significantly improving tear strength and tensile strength, overcoming the defects of low strength and easy tearing of pure POE foam material.

[0019] (3) By using antioxidant 1010 / 168 in combination and hydrogenating the structure of hydrogenated styrene-butadiene-styrene block copolymer (SEBS), the heat and oxygen aging resistance of the material is significantly improved. After high and low temperature alternating damp heat test, the material has excellent performance retention rate and good appearance integrity, meeting the requirements for long-term use of car seat cushions. Detailed Implementation

[0020] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention; the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0021] Metrics for measuring "resilience" 1) Basic compression rebound rate (%) Reference standard: GB / T6670-2008 This indicator directly reflects the instantaneous rebound capability of car seat cushions. When the rebound rate is ≥65%, it means that the seat cushion will return to its original shape within 30 seconds after the user gets up, without any feeling of sagging after sitting for a long time. This is the basic criterion for high rebound. The car seat cushion filling material is cut into 50mm×50mm×25mm samples, compressed to 50% of its original thickness in an environment of 23±2℃ and held for 30 seconds before being released. The basic compression rebound rate (%) = (sample thickness after rebound - instantaneous thickness during compression) / (original sample thickness - instantaneous thickness during compression) × 100%.

[0022] 2) Rebound rate retention after fatigue (%) Reference standard: GB / T18943-2008 (in conjunction with cyclic compression test) This indicator reflects the long-term rebound stability of car seat cushions. For example, a retention rate of ≥80% after 100,000 cycles means that the cushion's rebound ability does not decrease during long-term use, preventing it from collapsing over time. First, the cushion is compressed and rebounded a specified number of times under long-term dynamic cycle test conditions. Then, the compression rebound rate after the cycle is measured. The rebound rate retention rate after fatigue (%) = (compression rebound rate after cycle / initial compression rebound rate) × 100%.

[0023] 3) Compression set (%) Reference standard: GB / T10654-2001 This indicator can be used to infer the long-term resilience of car seat cushions. When the deformation is ≤10%, it means that there is no residual collapse after long-term pressure, which is the key evidence of high resilience without decay. The sample is compressed to 50% of its original thickness and fixed. After being placed in an oven at 70±2℃ for 100 hours, it is taken out and cooled. After releasing the pressure for 24 hours, the thickness is measured. The permanent compression deformation (%) = (original thickness of the sample - average thickness after recovery) / (original thickness of the sample × 50%) × 100%.

[0024] 4) Rebound recovery time (s) Reference Standard: Refer to Appendix Method of GB / T6670-2008 This indicator reflects the rebound speed of the car seat cushion. When the recovery time is ≤30s, it means that the seat cushion bounces up quickly when the user gets up, without any lag or collapse, thus improving the smoothness of the sitting experience. The sample is compressed to 50% of its original thickness and held for 30s. The time required for the sample to recover to 90% of its original thickness is recorded when the pressure is released. This is the rebound recovery time.

[0025] Metrics for measuring "rigidity" 1) Tensile strength (MPa) Reference standard: GB / T1040.3-2006 This indicator reflects the overall fracture rigidity of the car seat cushion. A strength ≥ 2.5 MPa means that the seat cushion will not tear when getting in and out of the car, which is the basis for rigidity and durability. The material is cut into Type I dumbbell-shaped specimens (total length 115 mm, effective section length 25 mm, width 6 mm, thickness 2 mm), and stretched at a speed of 50 mm / min until fracture. Tensile strength (MPa) = maximum tensile force at fracture (N) / (effective section width of specimen (mm) × specimen thickness (mm)) × 10 -3 .

[0026] 2) Tear strength (kN / m) Reference standard: GB / T10808-2006 This indicator reflects the local resistance to tear propagation rigidity of the car seat cushion. When the strength is ≥10kN / m, it means that small holes caused by keys, etc., will not expand, avoiding local damage that could lead to overall scrapping. The material is cut into right-angled specimens (100mm long, 50mm wide, and 25mm thick), with a 25mm deep notch cut in the center of the wide side. It is then stretched at a speed of 50mm / min until it is completely torn. The tear strength (kN / m) = maximum tensile force at tear (N) / specimen thickness (mm) × 10 -3 .

[0027] 3) Stress at constant elongation (MPa) Reference standard: GB / T1040.3-2006 This indicator reflects the compressive support rigidity of the car seat cushion. When the constant elongation stress is ≥1.2MPa, it means that the seat cushion will not sag excessively when the user sits down (sag ≤30mm), balancing softness and support. A type I dumbbell-shaped specimen is used, stretched to 150% of its original length at a speed of 50mm / min, and the tensile force at this point is recorded. Constant elongation stress (MPa) = Tensile force at constant elongation (N) / (Effective section width of specimen (mm) × Specimen thickness (mm)) × 10 -3 .

[0028] To verify the performance stability of the automotive seat cushion of this invention under real-world long-term dynamic fatigue load scenarios, the following test scenarios were specifically designed. By simulating key damage sources in actual use of automotive seat cushions, the elasticity retention, rigidity durability, and environmental adaptability of the material were comprehensively evaluated. The design basis, core parameters, and verification objectives of each test scenario are as follows: Test Scenario 1: The simulation focuses on the intermittent "sit-up" movements of users during long-term use (such as getting on and off a vehicle every day, taking short breaks, calculated at 15 cycles per day, accumulating to approximately 109,500 times over 20 years), emphasizing the high-frequency dynamic pressure-rebound process to restore the core daily use state of the seat cushion.

[0029] Referencing GB / T18943-2008 "Determination of Compression Fatigue Properties of Molded and Extruded Foamed Plastics", the test parameters were optimized based on the actual usage intensity of car seat cushions (adult sitting pressure, sitting and stopping time).

[0030] Test method: The car seat cushion filling material was cut into 50mm×50mm×25mm cubic samples and placed in an environment of 23±2℃ and 50±5%RH for 24 hours to eliminate processing internal stress; the compression rate was adjusted to 10mm / min to match the natural speed of a human sitting down, and the compression amount was adjusted to 50% to simulate the actual pressure of a 70kg adult sitting on the seat cushion; an intermittent cycle of "compression → holding pressure → release" was adopted, with the holding pressure time set to two groups of 5min and 30min. The 5min time simulated a short sitting stop, and the 30min time simulated a long sitting and leaning. The ratio of the two groups of cycles was 1:1; the total number of cycles was set to 100,000 times, and the test environment was set to 23±2℃ and 50±5%RH to simulate the normal temperature and humidity inside a car in spring and autumn.

[0031] After the test, the thickness loss rate of the sample was recorded, and its compression rebound rate and tear strength were tested again to calculate its performance retention rate.

[0032] Test Scenario 2: Simulating the use of car seats throughout the year and across seasons, this study recreates the cumulative aging damage caused by temperature and humidity changes, covering the effects of 20 years of seasonal changes.

[0033] Referring to GB / T2423.1-2008 "Environmental Testing for Electrical and Electronic Products - Part 2: Test Methods - Test A: Low Temperature" and GB / T2423.4-2008 "Test Db: Alternating Damp Heat", the parameters were adjusted based on the actual tolerance requirements of automotive interiors.

[0034] Test method: The car seat cushion filling material was cut into 50mm×50mm×25mm cubic samples and placed in an environment of 23±2℃ and 50±5%RH for 24 hours to eliminate the internal stress of processing. The environment was cycled in the following manner: "low temperature → heating up → high temperature and high humidity → cooling down → room temperature". One cycle was 24 hours (corresponding to one season unit) and a total of 100 cycles were performed. Specifically, the cycle was: -30℃ constant temperature for 8 hours (simultaneous 50% compression to simulate sitting on a cold seat in winter) → heating up to 60℃ within 1 hour (humidity increased to 80%RH) → 60℃ and 80%RH constant temperature for 8 hours (simultaneous 50% compression to simulate sitting on a hot seat in summer) → cooling down to 23℃ within 1 hour (humidity decreased to 50%RH) → 23℃ and 50%RH constant temperature for 6 hours (release compression to simulate idleness in spring and autumn). After the cycle, 50,000 intermittent cycles of scenario one were immediately performed.

[0035] Test Scenario 3: Simulating the conditions of car seat cushions under long-term outdoor parking and friction when getting in and out of the car, it recreates the dual damage of "UV aging + mechanical friction".

[0036] The parameters were optimized based on GB / T16422.2-2014 "Plastics - Laboratory Light Source Exposure Tests - Part 2: Xenon Arc Lamp" and GB / T3920-2008 "Textiles - Color Fastness to Abrasion", taking into account the intensity of outdoor use.

[0037] Test method: Polyester fiber surface fabric was bonded to the surface of the car seat cushion filling material. The substrate size was 50mm×50mm×25mm. It was placed in an environment of 23±2℃ and 50±5%RH for 24 hours to eliminate the internal stress of processing. First, xenon arc lamp aging was carried out: irradiance 0.71W / (m²・nm) to simulate midday sunlight, black mark temperature 65±3℃ to simulate the temperature inside the car after exposure to the sun, aging for 1000 hours to simulate long-term outdoor exposure to the sun. Then, friction test was carried out: denim cloth was rubbed against the fabric, 500g pressure was applied, speed 30 times / min, total friction 50,000 times, and 30% compression was applied simultaneously to simulate local pressure in a half-sitting state. After friction, 10,000 intermittent cycles of scenario one were carried out.

[0038] Example 1 A high-resilience car seat cushion filling material, composed of the following components in parts by weight: 50 parts ethylene-1-octene copolymer (POE), with a melt flow rate (190℃ / 2.16kg) of 1.0 g / 10 min, ensures excellent elasticity; 20 parts polypropylene (PP), with isotacticity ≥96% and melt index (230℃ / 2.16kg) of 2.5 g / 10 min, enhances material rigidity; 15 parts ethylene-vinyl acetate copolymer (EVA), with a vinyl acetate (VA) content of 24% and a melt flow rate (190℃ / 2.16kg) of 2.5 g / 10 min, enhances elasticity and compatibility; 10 parts hydrogenated styrene-butadiene-styrene block copolymer (SEBS), with a styrene / ethylene-butene mass ratio of 30 / 70 and a Shore hardness (A) of 65, improves the stability of the elastic network; 8 parts talc Powder with a particle size of 4000 mesh and a whiteness of ≥95% is used as a nucleating agent to refine the foam cells; 3 parts azodicarbonamide (AC foaming agent) with a purity of ≥99% and a decomposition temperature of 165-175℃ is used to ensure foaming efficiency; 0.8 parts dicumyl peroxide (DCP) with a purity of ≥98% and a half-life (160℃) of 1.5h is used as a crosslinking agent to enhance the elastic network; 1.5 parts zinc oxide with a particle size of 500 mesh is used as an activator for DCP to improve crosslinking efficiency; 1.0 part zinc stearate with a purity of ≥98% is used as a lubricant and release agent to improve processing fluidity; 0.3 parts antioxidant 1010, a hindered phenolic primary antioxidant, inhibits thermo-oxidative aging; 0.3 parts antioxidant 168, a phosphite auxiliary antioxidant, is compounded with antioxidant 1010 at a mass ratio of 1:1 to synergistically improve aging resistance.

[0039] A method for preparing a high-resilience automotive seat cushion filling material includes the following steps: S1: Weigh each component according to the above weight ratio using an electronic balance; azodicarbonamide is pre-mixed with 2 parts of POE (accounting for 4% of the total POE) in a high-speed mixer and mixed at 800 rpm for 3 minutes to form a pre-dispersion to prevent subsequent foaming agent agglomeration, and is ready for use.

[0040] S2: Add the remaining 48 parts POE, 20 parts PP, 15 parts EVA, 10 parts SEBS, 8 parts talc, 1.0 part zinc stearate, 0.3 parts antioxidant 1010, 0.3 parts antioxidant 168, and the azodicarbonamide predispersant prepared in S1 to a mixer. Set the initial temperature of the mixer to 90℃ and the speed to 40rpm. After all the materials are added, raise the temperature to 110℃ and maintain this temperature for 8 minutes to ensure that the resin is completely melted and the filler is evenly dispersed. During this period, the pressure in the mixer chamber should be controlled at 0.3-0.5MPa to prevent material overflow.

[0041] S3: Add 0.8 parts of dicumyl peroxide (DCP) and 1.5 parts of zinc oxide to the mixture obtained in S2 at one time; keep the internal mixer temperature at 110℃ and the speed at 35 rpm, and continue mixing for 4 minutes to control the crosslinking agent to be evenly dispersed and avoid local premature crosslinking. After mixing, discharge the material to obtain a uniform rubber mass.

[0042] S4: Transfer the rubber compound obtained in S3 to a two-roll mill. Set the roller temperature of the two-roll mill to 100-120℃, with the front roller at 110℃ and the rear roller at 105℃. Initially adjust the roller gap to 5mm. Perform three thin passes on the rubber compound, and adjust the roller gap to 3mm after each thin pass to enhance the uniformity of the material. Finally, adjust the roller gap to 8mm to produce a continuous sheet with a thickness of 8±0.5mm. Allow it to cool naturally to room temperature (23±2℃) for later use.

[0043] S5: Cut the sheet obtained in S4 into 200mm×200mm square blanks and place them into a customized automotive seat cushion filling core mold; move the mold into a hot press, set the foaming temperature to 170℃, the pressure to 15MPa, and the holding time to 12 minutes to ensure that the foaming agent is completely decomposed and the cells grow stably; during this period, the heating rate of the hot press is controlled at 5℃ / min to avoid excessive local temperature causing cell collapse.

[0044] S6: Demold the foamed product obtained in S5 from the mold. Note that the demolding temperature should be ≤80℃ to avoid heat deformation. Immediately place it in a constant temperature oven and set the oven temperature to 80℃ for 8 hours. During the curing process, turn the product over every 2 hours to ensure uniform heating. After completion, remove it and let it cool naturally to room temperature to obtain the high-resilience car seat cushion filling material.

[0045] The car seat cushion in this embodiment adopts a four-layer composite structure of "surface fabric + buffer transition layer + high resilience filling core layer + bottom support layer", which is made by hot melt bonding, edge sewing and fixing with installation accessories.

[0046] Example 2 A high-resilience car seat cushion filling material, composed of the following components in parts by weight: 55 parts ethylene-1-octene copolymer (POE), with a melt flow rate (190℃ / 2.16kg) of 1.2g / 10min, further enhance the material's elasticity; 15 parts polypropylene (PP), with isotacticity ≥97% and melt index (230℃ / 2.16kg) of 2.2g / 10min, improves compatibility with POE while ensuring rigidity; 12 parts ethylene-vinyl acetate copolymer (EVA), with a vinyl acetate (VA) content of 28% and a melt flow rate (190℃ / 2.16kg) of 2.8g / 10min, enhances elasticity and low-temperature toughness; 12 parts hydrogenated styrene-butadiene-styrene block copolymer (SEBS), with a styrene / ethylene-butene mass ratio of 30 / 70 and a Shore hardness (A) of 63, further optimizes the flexibility of the elastic network; 7 parts talc powder, with a particle size of 5... 000 mesh, whiteness ≥96%, serves as a nucleating agent to more efficiently refine cell structure; 3.2 parts azodicarbonamide (AC foaming agent), purity ≥99%, decomposition temperature 163-173℃, suitable for foaming requirements with slightly higher POE content; 0.7 parts dicumyl peroxide (DCP), purity ≥98%, half-life (160℃) 1.6h, balancing crosslinking efficiency and elasticity retention; 1.6 parts zinc oxide, particle size 500 mesh, serves as an activator for DCP, optimizing crosslinking effect by adjusting DCP dosage; 1.1 parts zinc stearate, purity ≥98%, serves as a lubricant and release agent, suitable for processing fluidity requirements with higher POE content; 0.3 parts antioxidant 1010, hindered phenolic primary antioxidant, inhibits thermo-oxidative aging; 0.3 parts antioxidant 168, phosphite auxiliary antioxidant, compounded with antioxidant 1010 at a mass ratio of 1:1, synergistically improves aging resistance.

[0047] A method for preparing a high-resilience automotive seat cushion filling material includes the following steps: S1: Weigh each component according to the above weight ratio using an electronic balance; azodicarbonamide is pre-mixed with 2.5 parts of POE (accounting for 4.5% of the total POE) in a high-speed mixer and mixed at 850 rpm for 2.5 minutes to form a pre-dispersion to prevent subsequent foaming agent agglomeration, and is ready for use.

[0048] S2: Add the remaining 52.5 parts POE, 15 parts PP, 12 parts EVA, 12 parts SEBS, 7 parts talc, 1.1 parts zinc stearate, 0.3 parts antioxidant 1010, 0.3 parts antioxidant 168, and the azodicarbonamide predispersant prepared in S1 to the internal mixer. Set the initial temperature of the internal mixer to 95℃ and the speed to 42 rpm. After all the materials are fully added, raise the temperature to 115℃ and maintain this temperature for 7 minutes to ensure that the resin is completely melted and the filler is evenly dispersed. During this period, the pressure in the mixing chamber should be controlled at 0.3-0.5 MPa to avoid material overflow.

[0049] S3: Add 0.7 parts of dicumyl peroxide (DCP) and 1.6 parts of zinc oxide to the mixture obtained in S2 at one time; keep the internal mixer temperature at 115℃ and the speed at 36rpm, and continue mixing for 3.5 minutes to control the crosslinking agent to be evenly dispersed and avoid local premature crosslinking. After mixing, discharge the material to obtain a uniform rubber mass.

[0050] S4: Transfer the rubber compound obtained in S3 to the open mill. Set the open mill roller temperature to 105-125℃ (115℃ for the front roller and 110℃ for the rear roller). Initially adjust the roller gap to 4.5mm. Perform three thin passes on the rubber compound, and adjust the roller gap to 2.8mm after each thin pass to enhance the uniformity of the material. Finally, adjust the roller gap to 7.5mm to obtain a continuous sheet with a thickness of 7.5±0.5mm. Allow it to cool naturally to room temperature (23±2℃) for later use.

[0051] S5: Cut the sheet obtained in S4 into 210mm×210mm square blanks and place them into a customized automotive seat cushion filling core mold; move the mold into a hot press, set the foaming temperature to 175℃, the pressure to 18MPa, and the holding time to 11 minutes to ensure that the foaming agent is completely decomposed and the cells grow stably; during this period, the heating rate of the hot press is controlled at 5.5℃ / min to avoid local overheating that could cause the cells to collapse.

[0052] S6: Demold the foamed product obtained in S5 from the mold. Note that the demolding temperature should be ≤80℃ to avoid heat deformation. Immediately place it in a constant temperature oven and set the oven temperature to 75℃ for 9 hours. During the curing process, turn the product over every 2 hours to ensure uniform heating. After completion, remove it and let it cool naturally to room temperature to obtain the high-resilience car seat cushion filling material.

[0053] The car seat cushion in this embodiment adopts a four-layer composite structure of "surface fabric + buffer transition layer + high resilience filling core layer + bottom support layer", which is made by hot melt bonding, edge sewing and fixing with installation accessories.

[0054] Example 3 A high-resilience car seat cushion filling material, composed of the following components in parts by weight: 8 parts ethylene-1-octene copolymer (POE) to ensure elasticity; 22 parts polypropylene (PP) with isotacticity ≥96%, increasing the dosage to enhance the overall rigidity of the material; 18 parts ethylene-vinyl acetate copolymer (EVA) with a vinyl acetate (VA) content of 18%, enhancing elasticity and compatibility with PP; 8 parts hydrogenated styrene-butadiene-styrene block copolymer (SEBS) with a styrene / ethylene-butene mass ratio of 30 / 70 and a Shore A hardness of 67, adapting to the increased elasticity requirements after increasing PP dosage; 9 parts talc with a particle size of 3000 mesh and whiteness ≥95%, serving as a nucleating agent to refine cell structure and improve processing fluidity; 2.8 parts azodicarbonamide (AC foaming agent), pure... The foaming efficiency is ≥99%, with a decomposition temperature of 165-175℃, suitable for reducing the amount of POE used; 0.9 parts of dicumyl peroxide (DCP), with a purity ≥98% and a half-life (160℃) of 1.5h, are added to match the elastic network strength after the increase in the proportion of PP; 1.5 parts of zinc oxide, with a particle size of 500 mesh, are used as an activator for DCP to improve crosslinking efficiency; 1.0 part of zinc stearate, with a purity ≥98%, are used as a lubricant and release agent to improve processing fluidity; 0.3 parts of antioxidant 1010, a hindered phenolic primary antioxidant, inhibits thermo-oxidative aging; 0.3 parts of antioxidant 168, a phosphite auxiliary antioxidant, are compounded with antioxidant 1010 at a mass ratio of 1:1 to synergistically improve aging resistance.

[0055] A method for preparing a high-resilience automotive seat cushion filling material includes the following steps: S1: Weigh each component according to the above weight ratio using an electronic balance; azodicarbonamide is pre-mixed with 1.8 parts of POE (accounting for 3.75% of the total POE) in a high-speed mixer and mixed at 750 rpm for 3.5 minutes to form a pre-dispersion to prevent subsequent foaming agent agglomeration, and is ready for use.

[0056] S2: Add the remaining 46.2 parts POE, 22 parts PP, 18 parts EVA, 8 parts SEBS, 9 parts talc, 1.0 part zinc stearate, 0.3 parts antioxidant 1010, 0.3 parts antioxidant 168, and the azodicarbonamide predispersant prepared in S1 to the internal mixer. Set the initial temperature of the internal mixer to 88℃ and the speed to 38 rpm. After all the materials are added, raise the temperature to 108℃ and maintain this temperature for 8.5 minutes to ensure that the resin is completely melted and the filler is evenly dispersed. During this period, the pressure in the mixing chamber should be controlled at 0.3-0.5 MPa to avoid material overflow.

[0057] S3: Add 0.9 parts of dicumyl peroxide (DCP) and 1.5 parts of zinc oxide to the mixture obtained in S2 at one time; keep the internal mixer temperature at 108℃ and the speed at 34rpm, and continue mixing for 4.5 minutes to control the crosslinking agent to be evenly dispersed and avoid local premature crosslinking. After mixing, discharge the material to obtain a uniform rubber mass.

[0058] S4: Transfer the rubber compound obtained in S3 to the open mill. Set the roller temperature of the open mill to 98-118℃ (108℃ for the front roller and 103℃ for the rear roller). Initially adjust the roller gap to 5.5mm. Perform three thin passes on the rubber compound, and adjust the roller gap to 3.2mm after each thin pass to enhance the uniformity of the material. Finally, adjust the roller gap to 8.5mm to obtain a continuous sheet with a thickness of 8.5±0.5mm. Allow it to cool naturally to room temperature (23±2℃) for later use.

[0059] S5: Cut the sheet obtained in S4 into 190mm×190mm square blanks and place them into a customized automotive seat cushion filling core mold; move the mold into a hot press, set the foaming temperature to 168℃, the pressure to 14MPa, and the holding time to 12.5 minutes to ensure that the foaming agent is completely decomposed and the cells grow stably; during this period, the heating rate of the hot press is controlled at 4.8℃ / min to avoid local overheating that could cause cell collapse.

[0060] S6: Demold the foamed product obtained in S5 from the mold. Note that the demolding temperature should be ≤80℃ to avoid heat deformation. Immediately place it in a constant temperature oven and set the oven temperature to 82℃ for 7.5 hours. Turn the product over every 2 hours during the curing process to ensure even heating. After completion, remove it and let it cool naturally to room temperature to obtain the high-resilience car seat cushion filling material.

[0061] The car seat cushion in this embodiment adopts a four-layer composite structure of "surface fabric + buffer transition layer + high resilience filling core layer + bottom support layer", which is made by hot melt bonding, edge sewing and fixing with installation accessories.

[0062] Example 4 A high-resilience car seat cushion filling material, composed of the following components in parts by weight: 52 parts ethylene-1-octene copolymer (POE) to strengthen the material's elasticity; 18 parts polypropylene (PP) with isotacticity ≥96%, reducing dosage to improve material flexibility; 16 parts ethylene-vinyl acetate copolymer (EVA) with vinyl acetate (VA) content of 22%, balancing elasticity and compatibility of components; 9 parts hydrogenated styrene-butadiene-styrene block copolymer (SEBS) with a styrene / ethylene-butene mass ratio of 30 / 70 and Shore A hardness of 64, adapting to the stability of the elastic network after increasing POE dosage; 7 parts talc with a particle size of 4500 mesh and whiteness ≥95%, finer particle size improves cell uniformity; 3.1 parts azodicarbonamide (AC foaming agent). ), purity ≥99%, decomposition temperature 165-175℃, suitable for foaming requirements after increasing POE content; 0.75 parts dicumyl peroxide (DCP), purity ≥98%, half-life (160℃) 1.5h, slight adjustment of dosage to retain more elasticity; 1.5 parts zinc oxide, particle size 500 mesh, as an activator of DCP to improve crosslinking efficiency; 1.2 parts zinc stearate, purity ≥98%, increased dosage to adapt to processing flowability with higher POE content; 0.3 parts antioxidant 1010, hindered phenolic main antioxidant, inhibits thermo-oxidative aging; 0.3 parts antioxidant 168, phosphite auxiliary antioxidant, compounded with antioxidant 1010 at a mass ratio of 1:1 to synergistically improve aging resistance.

[0063] A method for preparing a high-resilience automotive seat cushion filling material includes the following steps: S1: Weigh each component according to the above weight ratio using an electronic balance; azodicarbonamide is pre-mixed with 2.2 parts of POE (accounting for 4.23% of the total POE) in a high-speed mixer and mixed at 820 rpm for 2.8 minutes to form a pre-dispersion to prevent subsequent foaming agent agglomeration, and is ready for use.

[0064] S2: Add the remaining 49.8 parts POE, 18 parts PP, 16 parts EVA, 9 parts SEBS, 7 parts talc, 1.2 parts zinc stearate, 0.3 parts antioxidant 1010, 0.3 parts antioxidant 168, and the azodicarbonamide predispersant prepared in S1 to the internal mixer. Set the initial temperature of the internal mixer to 92℃ and the speed to 41rpm. After all the materials are added, raise the temperature to 112℃ and maintain this temperature for 7.5 minutes to ensure that the resin is completely melted and the filler is evenly dispersed. During this period, the pressure in the mixing chamber should be controlled at 0.3-0.5MPa to avoid material overflow.

[0065] S3: Add 0.75 parts of dicumyl peroxide (DCP) and 1.5 parts of zinc oxide to the mixture obtained in S2 at one time; keep the internal mixer temperature at 112℃ and the speed at 36 rpm, and continue mixing for 3.8 minutes to control the crosslinking agent to be evenly dispersed and avoid local premature crosslinking. After mixing, discharge the material to obtain a uniform rubber mass.

[0066] S4: Transfer the rubber compound obtained in S3 to the open mill. Set the roller temperature of the open mill to 102-122℃ (112℃ for the front roller and 107℃ for the rear roller). Initially adjust the roller gap to 4.8mm. Perform three thin passes on the rubber compound, and adjust the roller gap to 2.9mm after each thin pass to enhance the uniformity of the material. Finally, adjust the roller gap to 7.8mm to obtain a continuous sheet with a thickness of 7.8±0.5mm. Allow it to cool naturally to room temperature (23±2℃) for later use.

[0067] S5: Cut the sheet obtained in S4 into 205mm×205mm square blanks and place them into a customized automotive seat cushion filling core mold; move the mold into a hot press, set the foaming temperature to 172℃, the pressure to 16MPa, and the holding time to 11.5 minutes to ensure that the foaming agent is completely decomposed and the cells grow stably; during this period, the heating rate of the hot press is controlled at 5.2℃ / min to avoid local overheating that could cause cell collapse.

[0068] S6: Demold the foamed product obtained in S5 from the mold. Note that the demolding temperature should be ≤80℃ to avoid heat deformation. Immediately place it in a constant temperature oven and set the oven temperature to 78℃ for 8.5 hours. Turn the product over every 2 hours during the curing process to ensure uniform heating. After completion, remove it and let it cool naturally to room temperature to obtain the high-resilience car seat cushion filling material.

[0069] The car seat cushion in this embodiment adopts a four-layer composite structure of "surface fabric + buffer transition layer + high resilience filling core layer + bottom support layer", which is made by hot melt bonding, edge sewing and fixing with installation accessories.

[0070] Comparative Example 1 A high-resilience car seat cushion filling material, composed of the following components in parts by weight: 50 parts ethylene-1-octene copolymer (POE); 20 parts polypropylene (PP); 15 parts ethylene-vinyl acetate copolymer (EVA); 8 parts talc; 3 parts azodicarbonamide; 0.8 parts dicumyl peroxide; 1.5 parts zinc oxide; 1.0 part zinc stearate; 0.3 parts antioxidant 1010; 0.3 parts antioxidant 168.

[0071] A method for preparing a high-resilience automotive seat cushion filling material includes the following steps: S1: Weigh each component according to the ratio; mix azodicarbonamide with 2 parts of POE in a high-speed mixer to form a pre-dispersion for later use.

[0072] S2: Add the remaining POE, PP, EVA, talc, zinc stearate, antioxidant, and the pre-dispersion of S1 to a mixer and mix.

[0073] S3: Add dicumyl peroxide and zinc oxide to the S2 mixture, continue mixing and then discharge to obtain rubber aggregate.

[0074] S4: Transfer the rubber compound to the open mill, pass it through a thin sheet, and let it cool naturally to room temperature for later use.

[0075] S5: Cut the sheet into square blanks, place them in a custom mold, and then transfer them to a hot press for foaming.

[0076] S6: After the foamed product is demolded, it is placed in a constant temperature oven for curing, and turned over periodically during the process. After cooling, the filling material is obtained.

[0077] Comparative Example 2 A high-resilience car seat cushion filling material, composed of the following components in parts by weight: 55 parts ethylene-1-octene copolymer (POE); 15 parts polypropylene (PP); 12 parts ethylene-vinyl acetate copolymer (EVA), VA content 28%; 12 parts hydrogenated styrene-butadiene-styrene block copolymer (SEBS), Shore hardness A63; 7 parts talc, particle size 5000 mesh; 3.2 parts azodicarbonamide; 0.7 parts dicumyl peroxide; 1.6 parts zinc oxide; 1.1 parts zinc stearate; 0.3 parts antioxidant 1010; 0.3 parts antioxidant 168.

[0078] A method for preparing a high-resilience automotive seat cushion filling material includes the following steps: S1: Weigh each component according to the formula; put azodicarbonamide and 2.5 parts of POE into a high-speed mixer and mix at 850 rpm for 2.5 minutes to form a pre-dispersion for later use.

[0079] S2: Add the remaining 52.5 parts POE, 15 parts PP, 12 parts EVA, 12 parts SEBS, 7 parts talc, 1.1 parts zinc stearate and the pre-dispersion of S1 to a mixer and mix. The initial temperature is 95℃ and the speed is 42rpm. After heating to 115℃, mix for 7 minutes.

[0080] S3: Add 0.7 parts of dicumyl peroxide and 1.6 parts of zinc oxide to the S2 mixture, and mix at 115°C and 36 rpm for 3.5 minutes. After discharge, a rubber mass is obtained.

[0081] S4: Transfer the rubber compound to the open mill. The roller temperature is 115℃ at the beginning and 110℃ at the end. The initial roller gap is 4.5mm. After three thin passes (the roller gap is adjusted to 2.8mm after each thin pass), the final roller gap is 7.5mm. A continuous sheet with a thickness of 7.5±0.5mm is produced and naturally cooled to room temperature for later use.

[0082] S5: Cut the sheet into 210mm×210mm square blanks, place them in a custom mold, and then transfer them to a hot press for foaming; hot pressing temperature 175℃, pressure 18MPa, holding pressure for 11 minutes, heating rate 5.5℃ / min.

[0083] S6: After the foamed product is demolded, it is placed in a constant temperature oven and cured at 75°C for 9 hours, turning it over every 2 hours during the process. After cooling, the filling material is obtained.

[0084] Comparative Example 3 A high-resilience car seat cushion filling material, composed of the following components in parts by weight: 20 parts ethylene-1-octene copolymer (POE); 20 parts polypropylene (PP); 15 parts ethylene-vinyl acetate copolymer (EVA); 10 parts hydrogenated styrene-butadiene-styrene block copolymer (SEBS); 8 parts talc; 3 parts azodicarbonamide; 0.8 parts dicumyl peroxide; 1.5 parts zinc oxide; 1.0 part zinc stearate; 0.3 parts antioxidant 1010; 0.3 parts antioxidant 168.

[0085] A method for preparing a high-resilience automotive seat cushion filling material includes the following steps: S1: Weigh each component according to the ratio; mix azodicarbonamide with 2 parts of POE in a high-speed mixer to form a pre-dispersion for later use.

[0086] S2: Add the remaining POE, PP, EVA, SEBS, talc, zinc stearate, antioxidant, and the pre-dispersion of S1 to a mixer and mix.

[0087] S3: Add dicumyl peroxide and zinc oxide to the S2 mixture, continue mixing and then discharge to obtain rubber aggregate.

[0088] S4: Transfer the rubber compound to the open mill, pass it through a thin sheet, and let it cool naturally to room temperature for later use.

[0089] S5: Cut the sheet into square blanks, place them in a custom mold, and then transfer them to a hot press for foaming.

[0090] S6: After the foamed product is demolded, it is placed in a constant temperature oven for curing, and turned over periodically during the process. After cooling, the filling material is obtained.

[0091] Comparative Example 4 A high-resilience car seat cushion filling material, composed of the following components in parts by weight: 35 parts ethylene-1-octene copolymer (POE); 35 parts polypropylene (PP); 15 parts ethylene-vinyl acetate copolymer (EVA); 10 parts hydrogenated styrene-butadiene-styrene block copolymer (SEBS); 8 parts talc; 3 parts azodicarbonamide; 0.8 parts dicumyl peroxide; 1.5 parts zinc oxide; 1.0 part zinc stearate; 0.3 parts antioxidant 1010; 0.3 parts antioxidant 168.

[0092] A method for preparing a high-resilience automotive seat cushion filling material includes the following steps: S1: Weigh each component according to the ratio; mix azodicarbonamide with 2 parts of POE in a high-speed mixer to form a pre-dispersion for later use.

[0093] S2: Add the remaining POE, PP, EVA, SEBS, talc, zinc stearate, antioxidant, and the pre-dispersion of S1 to a mixer and mix.

[0094] S3: Add dicumyl peroxide and zinc oxide to the S2 mixture, continue mixing and then discharge to obtain rubber aggregate.

[0095] S4: Transfer the rubber compound to the open mill, pass it through a thin sheet, and let it cool naturally to room temperature for later use.

[0096] S5: Cut the sheet into square blanks, place them in a custom mold, and then transfer them to a hot press for foaming.

[0097] S6: After the foamed product is demolded, it is placed in a constant temperature oven for curing, and turned over periodically during the process. After cooling, the filling material is obtained.

[0098] Comparative Example 5 A high-resilience car seat cushion filling material, composed of the following components in parts by weight: 35 parts ethylene-1-octene copolymer (POE); 35 parts polypropylene (PP); 5 parts ethylene-vinyl acetate copolymer (EVA); 10 parts hydrogenated styrene-butadiene-styrene block copolymer (SEBS); 8 parts talc; 3 parts azodicarbonamide; 0.8 parts dicumyl peroxide; 1.5 parts zinc oxide; 1.0 part zinc stearate; 0.3 parts antioxidant 1010; 0.3 parts antioxidant 168.

[0099] A method for preparing a high-resilience automotive seat cushion filling material includes the following steps: S1: Weigh each component according to the ratio; mix azodicarbonamide with 2 parts of POE in a high-speed mixer to form a pre-dispersion for later use.

[0100] S2: Add the remaining POE, PP, EVA, SEBS, talc, zinc stearate, antioxidant, and the pre-dispersion of S1 to a mixer and mix.

[0101] S3: Add dicumyl peroxide and zinc oxide to the S2 mixture, continue mixing and then discharge to obtain rubber aggregate.

[0102] S4: Transfer the rubber compound to the open mill, pass it through a thin sheet, and let it cool naturally to room temperature for later use.

[0103] S5: Cut the sheet into square blanks, place them in a custom mold, and then transfer them to a hot press for foaming.

[0104] S6: After the foamed product is demolded, it is placed in a constant temperature oven for curing, and turned over periodically during the process. After cooling, the filling material is obtained.

[0105] Comparative Example 6 A high-resilience car seat cushion filling material, composed of the following components in parts by weight: 50 parts ethylene-1-octene copolymer (POE); 20 parts polypropylene (PP); 15 parts ethylene-vinyl acetate copolymer (EVA); 10 parts hydrogenated styrene-butadiene-styrene block copolymer (SEBS); 8 parts talc; 1.5 parts azodicarbonamide; 0.8 parts dicumyl peroxide; 1.5 parts zinc oxide; 1.0 part zinc stearate; 0.3 parts antioxidant 1010; 0.3 parts antioxidant 168.

[0106] A method for preparing a high-resilience automotive seat cushion filling material includes the following steps: S1: Weigh each component according to the ratio; mix azodicarbonamide with 2 parts of POE in a high-speed mixer to form a pre-dispersion for later use.

[0107] S2: Add the remaining POE, PP, EVA, SEBS, talc, zinc stearate, antioxidant, and the pre-dispersion of S1 to a mixer and mix.

[0108] S3: Add dicumyl peroxide and zinc oxide to the S2 mixture, continue mixing and then discharge to obtain rubber aggregate.

[0109] S4: Transfer the rubber compound to the open mill, pass it through a thin sheet, and let it cool naturally to room temperature for later use.

[0110] S5: Cut the sheet into square blanks, place them in a custom mold, and then transfer them to a hot press for foaming.

[0111] S6: After the foamed product is demolded, it is placed in a constant temperature oven for curing, and turned over periodically during the process. After cooling, the filling material is obtained.

[0112] The car seat cushion samples prepared according to the raw materials and steps of Examples 1, 2, 3, 4 and Comparative Examples 1, 2, 3, 4, 5, 6 were subjected to performance tests under different scenarios. Table 1: Initial performance data of each sample Regarding rebound performance, the basic compression rebound rates of Examples 1 to 4 reached 86.5%, 87.2%, 85.8%, and 86.9%, respectively, all above 85%. This data indicates that the car seat cushion manufactured by this invention can quickly rebound when the user gets up, providing good immediate comfort. Furthermore, the compression set indices of Examples 1 to 4 were 9.2%, 8.7%, 9.8%, and 9%, respectively. Except for Example 3, which slightly exceeded 10%, the rest were all below 10%, significantly better than Comparative Example 1 (15.6%) lacking SEBS and Comparative Example 5 (16.8%) with low EVA. This essentially proves the excellent shape memory and recovery ability of the material of this invention, fundamentally reducing the risk of permanent collapse after long-term use. Moreover, the rebound recovery times of the car seat cushions of Examples 1 to 4 were 25 seconds, 24 seconds, 26 seconds, and 25 seconds, respectively, all shorter than 30 seconds, demonstrating rapid response and further improving the user experience.

[0113] In terms of mechanical strength, the tear strengths of Examples 1 to 4 reached 42.5 kN / m, 41.8 kN / m, 43.6 kN / m, and 42 kN / m, respectively, all exceeding 40 kN / m. This means that the car seat cushion has good resistance to tear propagation, and scratches during daily use are unlikely to cause overall structural damage. In contrast, Comparative Example 1, lacking SEBS, had a tear strength of only 28.3 kN / m, and Comparative Example 5, with low EVA, had a tear strength of only 31.7 kN / m, highlighting the key role of SEBS in reinforcing the network structure. Meanwhile, the tensile strength (1.78-1.92 MPa) and constant elongation stress @150% (1.25-1.32 MPa) of Examples 1 to 4 both indicate that the material itself possesses high tensile strength and strong supporting rigidity, effectively supporting the weight of the human body and preventing excessive sagging.

[0114] Examples 1 to 4 demonstrate that the car seat cushion manufactured by this invention achieves a balance between high resilience and excellent rigidity in its initial state, laying the foundation for subsequent durability.

[0115] Table 2: Performance data of each sample after 100,000 daily sit-up cycles test In terms of fatigue deformation resistance and structural stability, thickness loss rate is a direct indicator of whether a material will be thinned. The thickness loss rates of Examples 1 to 4 are between 3.8% and 4.5%, which is at a low level. This means that even after 100,000 cycles of pressure, their dimensions remain stable. In contrast, Comparative Example 1, lacking SEBS, has a thickness loss rate as high as 12.5%, and Comparative Example 5, with low EVA, reaches 14.1%, indicating that they are prone to collapse and deformation in real-world use, resulting in a shorter lifespan. Data on secondary compression set further corroborates this conclusion. The secondary compression set of Examples 1 to 4 is controlled at 9.9%-11.2%, showing little change and remaining at a low level. However, the deformation of Comparative Example 1 has intensified to 21.8%, and Comparative Example 5 reaches 24.1%, indicating that the material is close to failure.

[0116] Regarding performance retention, Examples 1 to 4 exhibited post-fatigue springback retention rates of 95.8% to 97.1%, and tear strength retention rates remained at a high level of 94.7% to 96.2%. These data demonstrate that the material of this invention is not only durable but also maintains comfortable elasticity and good strength under long-term dynamic fatigue loading. In contrast, the comparative examples all showed significant performance declines to varying degrees. In particular, Comparative Example 1, lacking SEBS, saw its springback retention rate drop to 82.3%, and its tear strength retention rate to only 78.5%, indicating a clear degradation in material function.

[0117] Table 3: Performance data of each sample after cross-seasonal high and low temperature fatigue testing Regarding performance retention, after enduring seasonal thermal cycling and 50,000 additional fatigue cycles, the springback retention rate of Examples 1 to 4 remained as high as 93.5% to 94.8%, and the tear strength retention rate also remained at a high level of 92.0% to 93.7%. This indicates that the elasticity and strength degradation of the material of this invention are very limited regardless of extreme cold or heat. In contrast, both performance indicators of all comparative examples showed a significant decline. The springback retention rate and tear strength retention rate of Comparative Example 1, which lacks SEBS, dropped to 75.6% and 72.8%, respectively, while that of Comparative Example 5, which has low EVA, dropped even further to 73.1% and 70.2%, meaning that the material's performance declined significantly after experiencing environmental aging and fatigue. Although Comparative Example 4 had a higher initial tear strength, its springback retention rate was only 82.4%, significantly lower than that of the examples, confirming its poor performance balance. The data from the three compression set data further amplified this gap. Examples 1 to 4 maintained a growth rate of 12.1%-13.5%, achieving controllable growth, while the deformation of Comparative Examples 1, 4, and 5 increased to 28.5%, 31.8%, and 20.8%, respectively, indicating that the material had undergone irreversible structural damage.

[0118] In summary, this invention employs a quaternary composite system of POE, PP, EVA, and SEBS, and optimizes their weight ratio to achieve a synergistic effect among the components: POE acts as the basic elastomer, providing overall resilience; PP acts as a rigid supporting framework, ensuring the overall strength of the material; EVA acts as a polar compatibilizer, effectively improving the compatibility and dispersibility among the components; and the physical cross-linked network structure of SEBS is key to achieving high resilience and excellent fatigue resistance. This system enables the filler material to possess both high resilience and high tear strength in its initial state. Simulated 100,000 sit-and-stand cycle tests, the low thickness loss rate and high performance retention rate of Examples 1 to 4, as well as the controllable increase in compression set, all demonstrate that the constructed three-dimensional network structure can effectively resist long-term dynamic stress, avoiding problems such as permanent collapse and performance degradation that are common in conventional materials, thus extending service life. After undergoing 100 cycles of high and low temperature alternating damp heat aging tests, the material properties of this invention remain good, indicating that the system has good resistance to heat and oxygen aging and hydrolysis resistance, and its comprehensive durability can meet the long-term use requirements of automotive seat cushions under all climate conditions.

[0119] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above description is illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A high-resilience car seat cushion filling material, characterized in that, It consists of the following components in parts by weight: 45-55 parts ethylene-1-octene copolymer (POE); 15-25 parts polypropylene (PP); 10-20 parts ethylene-vinyl acetate copolymer (EVA); 5-15 parts hydrogenated styrene-butadiene-styrene block copolymer (SEBS); 5-10 parts talc; 2-4 parts azodicarbonamide; 0.5-1.0 parts dicumyl peroxide; 1-2 parts zinc oxide; 0.5-1.5 parts zinc stearate; 0.1-0.5 parts antioxidant 1010; 0.1-0.5 parts antioxidant 168; The antioxidant 1010 and antioxidant 168 are in a mass ratio of 1:1; the vinyl acetate (VA) content in the ethylene-vinyl acetate copolymer (EVA) is 18%-28%; the styrene / ethylene-butene mass ratio in the hydrogenated styrene-butadiene-styrene block copolymer (SEBS) is 30 / 70; and the talc has a particle size of 3000-5000 mesh. The isotacticity of the polypropylene is ≥96%.

2. The high-resilience automotive seat cushion filling material according to claim 1, characterized in that, The amount of the ethylene-1-octene copolymer (POE) is 50-55 parts.

3. The high-resilience automotive seat cushion filling material according to claim 1, characterized in that, The talc powder has a particle size of 4000-5000 mesh.

4. A method for preparing a high-resilience automotive seat cushion filling material as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1. Weigh each component according to the stated weight ratio; wherein, the azodicarbonamide is pre-mixed with a portion of the ethylene-1-octene copolymer (POE) to form a pre-dispersion; S2. Add POE, PP, EVA, SEBS, talc, zinc stearate and antioxidant to a mixer and mix at 90-110°C for 5-10 minutes. S3. Add azodicarbonamide predispersant, dicumyl peroxide and zinc oxide to the mixture obtained in step S2, and continue to mix for 3-5 minutes; S4. Transfer the mixture obtained in step S3 to a two-roll mill, pass it through a thin mill three times at 100-120°C, and then produce a sheet. S5. After cutting the sheet obtained in step S4, place it into the mold and perform molding foaming on a hot press. The foaming temperature is 160-180°C, the pressure is 15-20MPa, and the time is 8-15 minutes. S6. After demolding the foamed product obtained in step S5, cure it at 70-90°C for 6-10 hours to obtain the high-resilience car seat cushion filling material.

5. The preparation method according to claim 4, characterized in that, The pressure for compression molding and foaming in step S5 is 15-20 MPa.

6. A car seat cushion, characterized in that, Made using the high-resilience automotive seat cushion filling material according to any one of claims 1 to 3, or made using the high-resilience automotive seat cushion filling material prepared by any one of claims 4 and 5.

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