Slow-resilience polyurethane sponge for automobile and preparation method of slow-resilience polyurethane sponge

Abstract

The invention discloses slow-rebound polyurethane sponge for an automobile and a preparation method of the slow-rebound polyurethane sponge, and belongs to the field of preparation of polyurethane sponge for the automobile. Raw materials comprise hollow glass beads, short carbon fibers, hydrophobic nano silicon dioxide, a silane coupling agent, polyether triol, modified MDI, deionized water, a catalyst, silicone oil, an antioxidant, epoxy silane, grafted polyether, clay, absolute ethyl alcohol, a dispersing aid and a stabilizer, and the raw materials are treated. According to the slow-rebound polyurethane sponge for the automobile and the preparation method of the slow-rebound polyurethane sponge, composite reinforced particles containing hollow glass beads, short carbon fibers and hydrophobic nano silicon dioxide are prepared and added into the sponge to form three supporting force areas, differential supporting is achieved, collapse is prevented, and materials are saved; and meanwhile, the transition area is arranged, so that smooth connection can be achieved, and stability, comfort and durability are improved.

Description

Technical Field

[0001] This invention relates to the field of automotive polyurethane foam preparation technology, and more specifically, to an automotive slow-rebound polyurethane foam and its preparation method. Background Technology

[0002] In the automotive industry, slow-rebound polyurethane foam is a core material for seats, and its support performance, durability, and comfort directly affect user experience and product lifespan. Traditional automotive slow-rebound polyurethane foam often uses a single material or homogeneous structure design, making it difficult to address the stress requirements of different areas: high-frequency stress areas such as the center and front are prone to collapse due to insufficient support, while over-reinforcing the outer areas leads to material waste and reduced comfort, failing to meet the automotive industry's stringent requirements for durability, lightweight, and cost control of slow-rebound foam. Therefore, developing a slow-rebound polyurethane foam that can achieve differentiated support, optimize regional connections, and provide highly efficient reinforcement has become an urgent technical problem to be solved.

[0003] There are currently no effective solutions to the problems in the relevant technologies. Summary of the Invention

[0004] In view of the problems in related technologies, this invention proposes a slow-rebound polyurethane foam for automobiles and its preparation method, so as to overcome the above-mentioned technical problems existing in the existing related technologies.

[0005] Therefore, the specific technical solution adopted by the present invention is as follows:

[0006] A method for preparing slow-rebound polyurethane foam for automobiles, the method comprising the following steps:

[0007] S1. Prepare the mold and raw materials. The raw materials consist of hollow glass microspheres, short-cut carbon fibers, hydrophobic nano-silica, silane coupling agent, polyether triol, modified MDI, deionized water, catalyst, silicone oil, antioxidant, epoxy silane, grafted polyether, clay, anhydrous ethanol, dispersant (sodium pyrophosphate), and stabilizer (ammonium polyacrylate). The raw materials are then processed.

[0008] S2. Prepare composite reinforced particles, as well as raw materials for the central region, front region, transition region and peripheral region;

[0009] S3. The raw materials are injected in a gradient manner in sections, foamed, and then cured.

[0010] In a preferred embodiment, the preparation of the mold and raw materials, wherein the raw materials consist of hollow glass microspheres, chopped carbon fibers, hydrophobic nano-silica, silane coupling agent, polyether triol, modified MDI, deionized water, catalyst silicone oil, antioxidant, epoxy silane, grafted polyether, clay, anhydrous ethanol, dispersant, and stabilizer, and the processing of the raw materials includes the following steps:

[0011] S11. Fix the TPU mesh in the center area and front edge of the mold, and apply hot melt adhesive to the bottom of the mesh;

[0012] S12. Prepare raw materials, which consist of hollow glass microspheres, short-cut carbon fibers, hydrophobic nano-silica, silane coupling agent, polyether triol, modified MDI, deionized water, catalyst silicone oil, antioxidant, epoxy silane, grafted polyether, clay, anhydrous ethanol, dispersant, and stabilizer.

[0013] S13. Mix the silane coupling agent with deionized water and stir at room temperature for 15 minutes until completely hydrolyzed to prepare a hydrolysate. Then transfer the hollow glass microspheres into a high-speed mixer, add the hydrolysate dropwise, and stir at 1500 rpm for 60 minutes at 80°C.

[0014] S14. Lay the short-cut carbon fibers flat in the plasma treatment chamber, introduce a mixture of argon and oxygen with a volume ratio of 95:5, treat for 120 seconds at 200W power, then dissolve the silane coupling agent in anhydrous ethanol and spray it evenly onto the surface of the activated fiber through an ultrasonic atomizing nozzle. Set the spraying rate to 0.5mL / min and the distance from the fiber to 15cm. Finally, dry the sprayed fiber under 50℃ hot air circulation for 30 minutes.

[0015] S15. Add deionized water to the reactor, heat to 30°C and keep it constant. Add the dispersing agent, then slowly sprinkle in the nano clay, controlling the feeding rate to ≤5g / min. Simultaneously turn on the high-speed shear and continue shearing for 30 minutes. Then reduce the speed to 800rpm and stir. Add the stabilizer and mature for 60 minutes until the viscosity stabilizes at 250±50cP. Transfer the clay dispersion slurry to a nitrogen-protected storage tank.

[0016] In a preferred embodiment, the preparation of the composite reinforced particles, as well as the raw materials for the central region, front region, transition region, and peripheral region, includes the following steps:

[0017] S21. Hollow glass microspheres, chopped carbon fibers, and hydrophobic nano-silica are put into a high-speed mixer under nitrogen protection and premixed at 800 rpm for 5 minutes.

[0018] S22. Feed the premixed material into a twin-screw extruder, set six temperature zones: feed zone 1 to 120℃, melt zone 1 to 145℃, melt zone 2 to 155℃, mixing zone to 155℃, homogenization zone to 150℃, die head to 140℃, screw speed to 150 rpm, and maintain melt pressure at 10 ± 0.5 MPa.

[0019] S23. Inject silane coupling agent into the molten zone 2 and activate the high-shear interlocking block to promote the coating of nano-silica onto the microbead-fiber interface. Continue mixing for 90 seconds. The melt is extruded through a porous template into the pelletizing tank. Set the rotating blade speed to 3000 rpm for pelletizing. The particle diameter is controlled to be 1.0-1.2 mm.

[0020] S24. The particles are fed into a vibrating fluidized bed with an amplitude of 2mm and a frequency of 25Hz. They are dried in a counter-current hot air flow at 60℃ for 30 minutes, with the moisture content controlled to be ≤0.05%.

[0021] S25. Immerse the dried particles in an ethanol solution containing fluorosilane, with a solid-liquid ratio of fluorosilane to ethanol solution of 1:3. Set the power to 300W and ultrasonically treat at 60℃ for 20 minutes to improve surface hydrophobicity.

[0022] S26. The particles are then transferred into a vacuum drum and slowly cooled to ≤35°C at a vacuum of -0.095MPa and a rotation speed of 5rpm. The residual solvent is removed simultaneously to complete the passivation cooling. Finally, the particles are passed through a Gauss electromagnetic iron remover and a metal detector to ensure that the metal impurity content is ≤5ppm, thus obtaining composite reinforced particles.

[0023] S27. Prepare raw materials for the central region, front region, transition region and peripheral region.

[0024] In a preferred embodiment, the preparation of the raw materials for the central region, the front region, the transition region, and the peripheral region includes the following steps:

[0025] S271. Polyether triol, deionized water, amine catalyst, organotin, silicone oil and antioxidant are added to a mixing tank and stirred to obtain a base material. The mixing speed is set to 1200 rpm and mixed for 30 seconds. Then, composite reinforcing particles are added. The material temperature is kept constant at 40±1℃ and the viscosity is 2500±100cP to obtain the raw material for the central area and the front area.

[0026] S272. Take the base material and add flexible polyether and plasticizer and stir to obtain the outer zone raw material, and maintain the material temperature at 35±1℃ and the viscosity at 1800±50cP.

[0027] S273. Take 50% of the raw materials from the central and front regions and 50% of the raw materials from the outer regions, then add epoxy silane, grafted polyether and nano clay slurry. Set the speed to 1200 rpm and mix for 10 seconds to achieve a gradient transition, and control the temperature at 37±0.5℃.

[0028] In a preferred embodiment, the step of dividing the raw material into zones, gradient injection foaming, and curing treatment includes the following steps:

[0029] S31. Preheat the foaming mold to the set temperature, and use a high-pressure injection machine to inject high-pressure material into the central area and the front area respectively, use a high-pressure injection machine to inject medium-pressure material into the transition area, and use a low-pressure injection machine to inject low-pressure material into the outer area.

[0030] The injection pressure in each area is matched with the material properties, and the preheated mold ensures uniform foaming and stable molding, thereby improving the overall structure coordination and durability of the sponge.

[0031] S32. After the mold is closed, apply stepped pressure and cure independently by area.

[0032] A slow-rebound polyurethane foam for automotive use, wherein the foam is prepared using a method for preparing a slow-rebound polyurethane foam for automotive use as described in any one of the above methods, and the specific composition of the polyurethane foam is as follows:

[0033] S1, the ingredients of the central area and the front area are composed of polyether triol, modified MDI, composite reinforcing particles, deionized water, amine catalyst, organotin catalyst, silicone oil surfactant, and antioxidant, wherein the amine catalyst is A-33, the organotin catalyst is T-12, the silicone oil surfactant is L-580, and the antioxidant is Irganox1135.

[0034] S2. The composite reinforced particles are composed of hollow glass microspheres, short-cut carbon fibers, hydrophobic nano-silica, and silane coupling agent, wherein the silane coupling agent is KH550.

[0035] S3, the ingredients of the peripheral zone are polyether triol, flexible polyether, modified MDI, deionized water, amine catalyst, organotin catalyst, silicone oil, antioxidant, and plasticizer, wherein the amine catalyst is A-33, the organotin catalyst is T-12, the silicone oil surfactant is L-580, the antioxidant is Irganox1135, and the plasticizer is DINCH.

[0036] In a preferred embodiment, the mass fractions of the ingredients in the central area and the front area are as follows:

[0037] S11, 67.37 parts of polyether triol, 20.46 parts of modified MDI, 8 parts of composite reinforcing particles, 2.34 parts of deionized water, 0.2 parts of amine catalyst, 0.07 parts of organotin catalyst, 1.04 parts of silicone oil surfactant, and 0.52 parts of antioxidant.

[0038] In a preferred embodiment, the mass fraction of the composite reinforced particles is as follows:

[0039] S21, 60.3 parts hollow glass microspheres, 25.5 parts short-cut carbon fibers, 13.4 parts hydrophobic nano-silica, and 0.8 parts silane coupling agent.

[0040] In a preferred embodiment, the mass fraction of the ingredients in the peripheral zone is:

[0041] S31, 61.14 parts of polyether triol, 2.96 parts of flexible polyether, 32.25 parts of modified MDI, 1.78 parts of deionized water, 0.15 parts of amine catalyst, 0.05 parts of organotin catalyst, 0.79 parts of silicone oil, 0.39 parts of antioxidant, and 0.49 parts of plasticizer.

[0042] The beneficial effects of this invention are as follows:

[0043] 1. This invention creates a pad with three levels of support by incorporating composite reinforcing particles into a sponge. This provides differentiated support for different areas with varying stress requirements. The central and front areas have stronger support due to the addition of composite reinforcing particles, effectively resisting pressure from the human body or objects during long-term use, preventing collapse in the center and periphery, and extending the lifespan of the sponge. Meanwhile, the amount of material used in the outer area can be adjusted according to actual support needs, eliminating the need for high-strength materials throughout. This reduces material consumption while ensuring support performance, achieving efficient material utilization.

[0044] 2. This invention creates a transition zone by mixing 50% of the central and front zone materials with 50% of the peripheral zone materials and adding flexible polyether and plasticizer. This allows for a smooth connection between areas with different support strengths. Through the mixing of materials and the action of additives, the transition zone eliminates the rigid interface caused by differences in support strength between the central, front, and peripheral zones, avoiding material cracking or delamination due to stress concentration and enhancing the overall stability of the sponge structure. Furthermore, the addition of flexible polyether and plasticizer improves the flexibility and plasticity of the transition zone, enabling it to better adapt to the deformation of adjacent areas and ensuring consistent overall deformation of the sponge under stress, further enhancing the comfort and durability of the sponge.

[0045] 3. The composite reinforcing particles prepared by this invention contain hollow glass microspheres, chopped carbon fibers, and hydrophobic nano-silica in their raw materials. The hollow glass microspheres are lightweight and high-strength, providing rigid support. The chopped carbon fibers enhance the tensile and shear resistance of the particles, forming a three-dimensional reinforcing network. The hydrophobic nano-silica, after being coated with a silane coupling agent, strengthens the interfacial bonding with the microspheres and fibers, improving the overall structural stability of the particles. The properties of these raw materials allow the composite reinforcing particles, when added to the central and front regions, to effectively disperse external pressure and resist deformation, thereby significantly improving the support of the sponge and preventing collapse. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a flowchart of a method for preparing a slow-rebound polyurethane foam for automobiles according to an embodiment of the present invention.

[0048] Figure 2 This is a sectional demonstration diagram of a slow-rebound polyurethane foam for automobiles according to an embodiment of the present invention.

[0049] In the diagram: A, central area and front area; B, transition area; C, outer area. Detailed Implementation

[0050] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0051] According to an embodiment of the present invention, a slow-rebound polyurethane foam for automobiles and a method for preparing the same are provided.

[0052] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments, such as... Figures 1-2 As shown, a method for preparing slow-rebound polyurethane foam for automobiles according to an embodiment of the present invention includes the following steps:

[0053] S1. Prepare the mold and raw materials. The raw materials consist of hollow glass microspheres, short-cut carbon fibers, hydrophobic nano-silica, silane coupling agent, polyether triol, modified MDI, deionized water, catalyst, silicone oil, antioxidant, epoxy silane, grafted polyether, clay, anhydrous ethanol, dispersant sodium pyrophosphate, and stabilizer ammonium polyacrylate. The raw materials are then processed.

[0054] Further, prepare the mold and raw materials. The raw materials consist of hollow glass microspheres, chopped carbon fibers, hydrophobic nano-silica, silane coupling agent, polyether triol, modified MDI, deionized water, catalyst silicone oil, antioxidant, epoxy silane, grafted polyether, clay, anhydrous ethanol, dispersant, and stabilizer. The raw materials are then processed through the following steps:

[0055] S11. Fix the TPU mesh in the center area and front edge of the mold, and apply hot melt adhesive to the bottom of the mesh;

[0056] S12. Prepare raw materials, which consist of hollow glass microspheres, short-cut carbon fibers, hydrophobic nano-silica, silane coupling agent, polyether triol, modified MDI, deionized water, catalyst silicone oil, antioxidant, epoxy silane, grafted polyether, clay, anhydrous ethanol, dispersant, and stabilizer.

[0057] S13. Mix the silane coupling agent with deionized water and stir at room temperature for 15 minutes until completely hydrolyzed to prepare a hydrolysate. Then transfer the hollow glass microspheres into a high-speed mixer, add the hydrolysate dropwise, and stir at 1500 rpm for 60 minutes at 80°C.

[0058] S14. Lay the short-cut carbon fibers flat in the plasma treatment chamber, introduce a mixture of argon and oxygen with a volume ratio of 95:5, treat for 120 seconds at 200W power, then dissolve the silane coupling agent in anhydrous ethanol and spray it evenly onto the surface of the activated fiber through an ultrasonic atomizing nozzle. Set the spraying rate to 0.5mL / min and the distance from the fiber to 15cm. Finally, dry the sprayed fiber under 50℃ hot air circulation for 30 minutes.

[0059] S15. Add deionized water to the reactor, heat to 30°C and keep it constant. Add the dispersing agent, then slowly sprinkle in the nano clay, controlling the feeding rate to ≤5g / min. Simultaneously turn on the high-speed shear and continue shearing for 30 minutes. Then reduce the speed to 800rpm and stir. Add the stabilizer and mature for 60 minutes until the viscosity stabilizes at 250±50cP. Transfer the clay dispersion slurry to a nitrogen-protected storage tank.

[0060] It should be noted that pretreatment of raw materials can significantly improve the overall performance of slow-rebound polyurethane foam: silane coupling agent hydrolysis followed by treatment of hollow glass microspheres can improve their interfacial compatibility with the polyurethane matrix through chemical bonding, enhance dispersion uniformity, and improve the material's mechanical strength; plasma treatment of short-cut carbon fibers can introduce active groups, which, combined with silane coupling agent spraying, can strengthen the bond between the fiber and the matrix, resulting in a superior reinforcing effect; nano-clay, after high-speed shearing and treatment with dispersing agents, forms a stable dispersion slurry that can be uniformly embedded in the polyurethane system, effectively improving the material's heat resistance, dimensional stability, and mechanical properties, laying a good raw material foundation for subsequent foam preparation;

[0061] S2. Prepare composite reinforced particles, as well as raw materials for the central region, front region, transition region and peripheral region;

[0062] Furthermore, the preparation of composite reinforced particles, as well as the raw materials for the central region, front region, transition region, and peripheral region, includes the following steps:

[0063] S21. Hollow glass microspheres, chopped carbon fibers, and hydrophobic nano-silica are put into a high-speed mixer under nitrogen protection and premixed at 800 rpm for 5 minutes.

[0064] S22. Feed the premixed material into a twin-screw extruder, set six temperature zones: feed zone 1 to 120℃, melt zone 1 to 145℃, melt zone 2 to 155℃, mixing zone to 155℃, homogenization zone to 150℃, die head to 140℃, screw speed to 150 rpm, and maintain melt pressure at 10 ± 0.5 MPa.

[0065] S23. Inject silane coupling agent into the molten zone 2 and activate the high-shear interlocking block to promote the coating of nano-silica onto the microbead-fiber interface. Continue mixing for 90 seconds. The melt is extruded through a porous template into the pelletizing tank. Set the rotating blade speed to 3000 rpm for pelletizing. The particle diameter is controlled to be 1.0-1.2 mm.

[0066] S24. The particles are fed into a vibrating fluidized bed with an amplitude of 2mm and a frequency of 25Hz. They are dried in a counter-current hot air flow at 60℃ for 30 minutes, with the moisture content controlled to be ≤0.05%.

[0067] S25. Immerse the dried particles in an ethanol solution containing fluorosilane, with a solid-liquid ratio of fluorosilane to ethanol solution of 1:3. Set the power to 300W and ultrasonically treat at 60℃ for 20 minutes to improve surface hydrophobicity.

[0068] S26. The particles are then transferred into a vacuum drum and slowly cooled to ≤35°C at a vacuum of -0.095MPa and a rotation speed of 5rpm. The residual solvent is removed simultaneously to complete the passivation cooling. Finally, the particles are passed through a Gauss electromagnetic iron remover and a metal detector to ensure that the metal impurity content is ≤5ppm, thus obtaining composite reinforced particles.

[0069] S27. Prepare raw materials for the central region, front region, transition region and peripheral region;

[0070] Furthermore, the preparation of raw materials for the central region, front region, transition region, and peripheral region includes the following steps:

[0071] S271. Polyether triol, deionized water, amine catalyst, organotin, silicone oil and antioxidant are added to a mixing tank and stirred to obtain a base material. The mixing speed is set to 1200 rpm and mixed for 30 seconds. Then, composite reinforcing particles are added. The material temperature is kept constant at 40±1℃ and the viscosity is 2500±100cP to obtain the raw material for the central area and the front area.

[0072] S272. Take the base material and add flexible polyether and plasticizer and stir to obtain the outer zone raw material, and maintain the material temperature at 35±1℃ and the viscosity at 1800±50cP.

[0073] S273. Take 50% of the raw materials from the central and front regions and 50% of the raw materials from the outer regions, then add epoxy silane, grafted polyether and nano clay slurry. Set the speed to 1200 rpm and mix for 10 seconds to achieve a gradient transition, and control the temperature at 37±0.5℃.

[0074] S3. The raw materials are injected in a gradient manner in sections, foamed, and then cured.

[0075] Furthermore, S31, the foaming mold is preheated to the set temperature, and high-pressure injection is performed on the central area and the front area respectively through a high-pressure injection machine, medium-pressure injection is performed on the transition area through a high-pressure injection machine, and low-pressure injection is performed on the outer area through a low-pressure injection machine.

[0076] It should be noted that high-pressure injection is used in the central and front areas, which, together with the composite reinforcing particles, makes the material denser, enhances the support strength to resist long-term pressure, and effectively prevents collapse; medium-pressure injection is used in the transition area, which ensures that the transition area can connect the performance of different areas and has good flexibility; low-pressure injection is used in the outer area, which reduces material compression while meeting the basic support requirements, and avoids material waste caused by excessive density.

[0077] S32. After the mold is closed, apply stepped pressure and cure independently by area.

[0078] A slow-rebound polyurethane foam for automobiles, wherein the foam is prepared using any of the above-mentioned methods, and the specific composition of the polyurethane foam is as follows:

[0079] S1, the ingredients of the central area and the front area are composed of polyether triol, modified MDI, composite reinforcing particles, deionized water, amine catalyst, organotin catalyst, silicone oil surfactant, and antioxidant, wherein the amine catalyst is A-33, the organotin catalyst is T-12, the silicone oil surfactant is L-580, and the antioxidant is Irganox1135.

[0080] Furthermore, the mass fractions of the ingredients in the central and front sections are as follows:

[0081] S11, 67.37 parts of polyether triol, 20.46 parts of modified MDI, 8 parts of composite reinforcing particles, 2.34 parts of deionized water, 0.2 parts of amine catalyst, 0.07 parts of organotin catalyst, 1.04 parts of silicone oil surfactant, and 0.52 parts of antioxidant.

[0082] S2. The composite reinforced particles are composed of hollow glass microspheres, short-cut carbon fibers, hydrophobic nano-silica, and silane coupling agent, wherein the silane coupling agent is KH550.

[0083] Furthermore, the mass fractions of the composite reinforced particles are as follows:

[0084] S21, 60.3 parts hollow glass microspheres, 25.5 parts short-cut carbon fibers, 13.4 parts hydrophobic nano-silica, and 0.8 parts silane coupling agent.

[0085] S3, the ingredients of the peripheral zone are polyether triol, flexible polyether, modified MDI, deionized water, amine catalyst, organotin catalyst, silicone oil, antioxidant, and plasticizer, wherein the amine catalyst is A-33, the organotin catalyst is T-12, the silicone oil surfactant is L-580, the antioxidant is Irganox1135, and the plasticizer is DINCH.

[0086] Furthermore, the mass fractions of the ingredients in the outer area are as follows:

[0087] S31, 61.14 parts of polyether triol, 2.96 parts of flexible polyether, 32.25 parts of modified MDI, 1.78 parts of deionized water, 0.15 parts of amine catalyst, 0.05 parts of organotin catalyst, 0.79 parts of silicone oil, 0.39 parts of antioxidant, and 0.49 parts of plasticizer.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing slow-rebound polyurethane foam for automobiles, characterized in that, The method includes the following steps: S1. Prepare molds and raw materials. The raw materials consist of hollow glass microspheres, short-cut carbon fibers, hydrophobic nano-silica, silane coupling agent, polyether triol, modified MDI, deionized water, catalyst, silicone oil, antioxidant, epoxy silane, grafted polyether, clay, anhydrous ethanol, dispersant, and stabilizer. The raw materials are then processed. S2. Prepare composite reinforced particles, as well as raw materials for the central region, front region, transition region and peripheral region; S3. The raw materials are injected in a gradient manner in sections, foamed, and then cured.

2. The method for preparing a slow-rebound polyurethane foam for automobiles according to claim 1, characterized in that, The preparation of the mold and raw materials, the raw materials being composed of hollow glass microspheres, chopped carbon fibers, hydrophobic nano-silica, silane coupling agent, polyether triol, modified MDI, deionized water, catalyst silicone oil, antioxidant, epoxy silane, grafted polyether, clay, anhydrous ethanol, dispersant, and stabilizer, and the processing of the raw materials includes the following steps: S11. Fix the TPU mesh in the center area and front edge of the mold, and apply hot melt adhesive to the bottom of the mesh; S12. Prepare raw materials, which consist of hollow glass microspheres, short-cut carbon fibers, hydrophobic nano-silica, silane coupling agent, polyether triol, modified MDI, deionized water, catalyst silicone oil, antioxidant, epoxy silane, grafted polyether, clay, anhydrous ethanol, dispersant, and stabilizer. S13. Mix the silane coupling agent with deionized water and stir at room temperature for 15 minutes until completely hydrolyzed to prepare a hydrolysate. Then transfer the hollow glass microspheres into a high-speed mixer, add the hydrolysate dropwise, and stir at 1500 rpm for 60 minutes at 80°C. S14. Lay the short-cut carbon fibers flat in the plasma treatment chamber, introduce a mixture of argon and oxygen with a volume ratio of 95:5, treat for 120 seconds at 200W power, then dissolve the silane coupling agent in anhydrous ethanol and spray it evenly onto the surface of the activated fiber through an ultrasonic atomizing nozzle. Set the spraying rate to 0.5mL / min and the distance from the fiber to 15cm. Finally, dry the sprayed fiber under 50℃ hot air circulation for 30 minutes. S15. Add deionized water to the reactor, heat to 30°C and keep it constant. Add the dispersing agent, then slowly sprinkle in the nano clay, controlling the feeding rate to ≤5g / min. Simultaneously turn on the high-speed shear and continue shearing for 30 minutes. Then reduce the speed to 800rpm and stir. Add the stabilizer and mature for 60 minutes until the viscosity stabilizes at 250±50cP. Transfer the clay dispersion slurry to a nitrogen-protected storage tank.

3. The method for preparing a slow-rebound polyurethane foam for automobiles according to claim 1, characterized in that, The preparation of the composite reinforced particles, as well as the raw materials for the central region, front region, transition region, and peripheral region, includes the following steps: S21. Hollow glass microspheres, chopped carbon fibers, and hydrophobic nano-silica are put into a high-speed mixer under nitrogen protection and premixed at 800 rpm for 5 minutes. S22. Feed the premixed material into a twin-screw extruder, set six temperature zones: feed zone 1 to 120℃, melt zone 1 to 145℃, melt zone 2 to 155℃, mixing zone to 155℃, homogenization zone to 150℃, die head to 140℃, screw speed to 150 rpm, and maintain melt pressure at 10 ± 0.5 MPa. S23. Inject silane coupling agent into the molten zone 2 and activate the high-shear interlocking block to promote the coating of nano-silica onto the microbead-fiber interface. Continue mixing for 90 seconds. The melt is extruded through a porous template into the pelletizing tank. Set the rotating blade speed to 3000 rpm for pelletizing. The particle diameter is controlled to be 1.0-1.2 mm. S24. The particles are fed into a vibrating fluidized bed with an amplitude of 2mm and a frequency of 25Hz. They are dried in a counter-current hot air flow at 60℃ for 30 minutes, with the moisture content controlled to be ≤0.05%. S25. Immerse the dried particles in an ethanol solution containing fluorosilane, with a solid-liquid ratio of fluorosilane to ethanol solution of 1:

3. Set the power to 300W and ultrasonically treat at 60℃ for 20 minutes to improve surface hydrophobicity. S26. The particles are then transferred into a vacuum drum and slowly cooled to ≤35°C at a vacuum of -0.095MPa and a rotation speed of 5rpm. The residual solvent is removed simultaneously to complete the passivation cooling. Finally, the particles are passed through a Gauss electromagnetic iron remover and a metal detector to ensure that the metal impurity content is ≤5ppm, thus obtaining composite reinforced particles. S27. Prepare raw materials for the central region, front region, transition region and peripheral region.

4. The method for preparing a slow-rebound polyurethane foam for automobiles according to claim 3, characterized in that, The preparation of raw materials for the central region, front region, transition region, and peripheral region includes the following steps: S271. Polyether triol, deionized water, amine catalyst, organotin, silicone oil and antioxidant are added to a mixing tank and stirred to obtain a base material. The mixing speed is set to 1200 rpm and mixed for 30 seconds. Then, composite reinforcing particles are added. The material temperature is kept constant at 40±1℃ and the viscosity is 2500±100cP to obtain the raw material for the central area and the front area. S272. Take the base material and add flexible polyether and plasticizer and stir to obtain the outer zone raw material, and maintain the material temperature at 35±1℃ and the viscosity at 1800±50cP. S273. Take 50% of the raw materials from the central and front regions and 50% of the raw materials from the outer regions, then add epoxy silane, grafted polyether and nano clay slurry. Set the speed to 1200 rpm and mix for 10 seconds to achieve a gradient transition, and control the temperature at 37±0.5℃.

5. The method for preparing a slow-rebound polyurethane foam for automobiles according to claim 1, characterized in that, The step of dividing the raw material into zones, gradient injection foaming and curing processes includes the following steps: S31. Preheat the foaming mold to the set temperature, and use a high-pressure injection machine to inject high-pressure material into the central area and the front area respectively, use a high-pressure injection machine to inject medium-pressure material into the transition area, and use a low-pressure injection machine to inject low-pressure material into the outer area. S32. After the mold is closed, apply stepped pressure and cure independently by area.

6. A slow-rebound polyurethane foam for automobiles, characterized in that, The system employs a method for preparing automotive slow-rebound polyurethane foam as described in any one of 1-5 above, wherein the specific composition of the polyurethane foam is as follows: S1, the ingredients of the central area and the front area are composed of polyether triol, modified MDI, composite reinforcing particles, deionized water, amine catalyst, organotin catalyst, silicone oil surfactant, and antioxidant, wherein the amine catalyst is A-33, the organotin catalyst is T-12, the silicone oil surfactant is L-580, and the antioxidant is Irganox1135. S2. The composite reinforced particles are composed of hollow glass microspheres, short-cut carbon fibers, hydrophobic nano-silica, and silane coupling agent, wherein the silane coupling agent is KH550. S3, the ingredients of the peripheral zone are polyether triol, flexible polyether, modified MDI, deionized water, amine catalyst, organotin catalyst, silicone oil, antioxidant, and plasticizer, wherein the amine catalyst is A-33, the organotin catalyst is T-12, the silicone oil surfactant is L-580, the antioxidant is Irganox1135, and the plasticizer is DINCH.

7. The slow-rebound polyurethane foam for automobiles according to claim 6, characterized in that, The mass fractions of the ingredients in the central area and the front area are: S11, 67.37 parts of polyether triol, 20.46 parts of modified MDI, 8 parts of composite reinforcing particles, 2.34 parts of deionized water, 0.2 parts of amine catalyst, 0.07 parts of organotin catalyst, 1.04 parts of silicone oil surfactant, and 0.52 parts of antioxidant.

8. The slow-rebound polyurethane foam for automobiles according to claim 6, characterized in that, The mass fractions of the composite reinforced particles are as follows: S21, 60.3 parts hollow glass microspheres, 25.5 parts short-cut carbon fibers, 13.4 parts hydrophobic nano-silica, and 0.8 parts silane coupling agent.

9. The slow-rebound polyurethane foam for automobiles according to claim 6, characterized in that, The mass fractions of the ingredients in the peripheral zone are: S31, 61.14 parts of polyether triol, 2.96 parts of flexible polyether, 32.25 parts of modified MDI, 1.78 parts of deionized water, 0.15 parts of amine catalyst, 0.05 parts of organotin catalyst, 0.79 parts of silicone oil, 0.39 parts of antioxidant, and 0.49 parts of plasticizer.

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