Environment-friendly heat-insulating automotive interior material and preparation method thereof

Abstract

The application relates to the field of thermal insulation materials, and more particularly to an environment-friendly thermal insulation automotive interior material and a preparation method thereof.The environment-friendly thermal insulation automotive interior material comprises, in mass parts, at least: low-density polyethylene 40-60 parts, polyester functional resin 15-30 parts, POE elastomer 20-30 parts, foaming agent 5-15 parts, crosslinking agent 0.5-2 parts and composite flame retardant 20-35 parts.The environment-friendly thermal insulation automotive interior material prepared through the application not only has excellent environment-friendly and thermal insulation properties, but also can maintain excellent durability, heat resistance, waterproofness and corrosion resistance and other performances of the interior material under the premise of limited cost, so as to meet the environment-friendly, thermal insulation and multifunctional requirements of the existing automotive field and consumers for the material.

Description

Technical Field

[0001] This application relates to the field of thermal insulation materials, and more specifically mentions an environmentally friendly thermal insulation automotive interior material and its preparation method. Background Technology

[0002] With the rapid development of the global automotive industry and consumers' increasing focus on in-vehicle environmental quality, the functionality and environmental friendliness of automotive interior materials have become core directions for industry research and development. As the direct contact medium within the vehicle's interior space, interior materials not only affect driving and riding comfort but are also closely related to the health and safety of occupants and the sustainable development of automobiles. Among these, the synergistic optimization of "environmental protection" and "thermal insulation" is a key requirement for the current technological upgrade of automotive interior materials.

[0003] Currently available automotive interior insulation materials mainly consist of EVA (ethylene-vinyl acetate copolymer) + PUR (polyurethane), EVA + polypropylene felt, or rigid felt + two-component sound-absorbing cotton. While these materials can meet basic heat and sound insulation requirements to some extent, they generally have some shortcomings. For example, improper control of the proportion of scrap materials mixed in EVA can affect the product's molding effect, aging properties, and sound insulation performance. Furthermore, heat insulation pads produced using foaming processes face problems such as complex processes, long production cycles, and poor on-site environments. Moreover, these products are mostly made of chemical materials with high levels of volatile substances, which can negatively impact the air quality inside the vehicle with long-term use.

[0004] Although researchers in this field have adopted other materials to replace the aforementioned materials in recent years to overcome these problems, thus solving the environmental and performance issues of traditional materials to some extent, some limitations still exist. For example, there is the issue of cost; the production cost of some high-performance new materials is relatively high, which limits the possibility of their large-scale application. In addition, some environmentally friendly materials still need further optimization in terms of durability, heat resistance, water resistance, and corrosion resistance before they can completely replace traditional materials. Summary of the Invention

[0005] In summary, addressing the issues of poor overall performance of existing automotive interior materials and high costs of new materials has become a crucial research topic for those skilled in the art. Through in-depth research in this technical field, the applicant proposes an environmentally friendly, heat-insulating automotive interior material and its preparation method in this application. The resulting environmentally friendly, heat-insulating automotive interior material not only possesses excellent environmental and heat insulation properties but also maintains good durability, heat resistance, water resistance, and corrosion resistance within a limited cost increase. Therefore, it can replace ordinary interior materials and meet the multifunctional needs of the automotive industry and consumers for such materials.

[0006] An environmentally friendly heat-insulating automotive interior material, by weight, comprises at least the following raw materials: 40-60 parts of low-density polyethylene, 15-30 parts of polyester functional resin, 20-30 parts of POE elastomer, 5-15 parts of foaming agent, 0.5-2 parts of crosslinking agent, and 20-35 parts of composite flame retardant.

[0007] In a preferred embodiment, the mass ratio of the low-density polyethylene, polyester functional tree and POE elastomer is (4.5~6):(1.8~2.5):(2.5~3).

[0008] In a preferred embodiment, the mass ratio of the low-density polyethylene, polyester functional tree, and POE elastomer is (4.5~5.5):(1.8~2.2):(2.5~2.8).

[0009] In a preferred embodiment, the ethylene content of the POE elastomer is 70-85 wt%.

[0010] In a preferred embodiment, the melt index of the POE elastomer is 1~1.5 g / 10min (190℃, 2.16kg).

[0011] In a preferred embodiment, the preparation method of the polyester functional resin specifically includes the following steps: S1: Dissolve the polyester resin in a solvent and purge with nitrogen to remove oxygen, add a mixture of trifluoroethyl methacrylate and N-phenylmaleimide dropwise, add dicumyl peroxide solution dropwise, react and keep stirring to obtain a prepolymer liquid; S2: Heat the prepolymer liquid, add vinyltris(2-methoxyethoxy)silane, stir evenly, add acetic acid and keep the reaction at a constant temperature, then add dibutyltin dilaurate and keep the reaction at a constant temperature, recover cyclohexanone after completion, and obtain the polyester functional resin from the remaining material.

[0012] In a preferred embodiment, the preparation method of the polyester functional resin specifically includes the following steps: S1: Dissolve the polyester resin in a solvent at 75~80℃ and purge with nitrogen for 25~30 min to remove oxygen, add a mixture of trifluoroethyl methacrylate and N-phenylmaleimide dropwise, add dicumyl peroxide solution dropwise, react at 80~85℃ for 4~4.5 h, and stir at 200~300 rpm to obtain a prepolymer solution; S2: Heat the prepolymer solution to 100~110℃, add vinyltris(2-methoxyethoxy)silane, stir evenly at 150~200 rpm, add 0.1~0.15 wt% acetic acid of total reactants, keep warm for 1~1.5 h, then add 0.03~0.05 wt% dibutyltin dilaurate of total reactants, keep warm at 120~125℃ for 1.5~2 h, after completion, recover cyclohexanone, and the remaining material is the polyester functional resin.

[0013] In a preferred embodiment, the mass ratio of the polyester resin, trifluoroethyl methacrylate, N-phenylmaleimide, and vinyltris(2-methoxyethoxy)silane is (12~15):(1.5~2.5):(0.8~1.6):(1~1.4).

[0014] In a preferred embodiment, the mass ratio of the polyester resin, trifluoroethyl methacrylate, N-phenylmaleimide, and vinyltris(2-methoxyethoxy)silane is (12~13):(1.5~2):(0.9~1.2):(1.2~1.3).

[0015] In a preferred embodiment, the melt index of the polyester resin is 5~7 g / 10min (230℃, 2.16 kg).

[0016] In a preferred embodiment, the foaming agent is at least one of azodicarbonamide, 4,4'-oxobis(benzenesulfonyl)hydrazine, and sodium bicarbonate.

[0017] In a preferred embodiment, the foaming agent is azodicarbonamide or 4,4'-oxobisbenzenesulfonylhydrazine.

[0018] In a preferred embodiment, the foaming agent is 4,4'-oxobisbenzenesulfonylhydrazine.

[0019] In a preferred embodiment, the crosslinking agent is at least one selected from dicumyl peroxide, tert-butyl peroxide, dicyclohexyl peroxide, and BIPB.

[0020] In a preferred embodiment, the crosslinking agent is BIPB or tert-butyl peroxide.

[0021] In a preferred embodiment, the crosslinking agent is BIPB.

[0022] In a preferred embodiment, the composite flame retardant is a composition of ammonium polyphosphate, magnesium hydroxide, red phosphorus, and aluminum hypophosphite.

[0023] In a preferred embodiment, the mass ratio of ammonium polyphosphate, magnesium hydroxide, red phosphorus and aluminum hypophosphite is (10~14):(6~8):(6~8):(3~5).

[0024] In a preferred embodiment, the mass ratio of ammonium polyphosphate, magnesium hydroxide, red phosphorus, and aluminum hypophosphite is (10~12):(6~7):(7~8):(3~4).

[0025] In a preferred embodiment, the environmentally friendly heat-insulating automotive interior material, by weight, further comprises: 5-12 parts of a composite composition, 0.5-2 parts of a lubricant, 1-3 parts of zinc oxide, and 1-3 parts of a colorant.

[0026] In a preferred embodiment, the mass ratio of the low-density polyethylene to the composite composition is (4.5~6):(0.6~1).

[0027] In a preferred embodiment, the mass ratio of the low-density polyethylene to the composite composition is (4.5~5.5):(0.8~1).

[0028] In a preferred embodiment, the composite composition is a combination of a hindered amine, an organosilicon polyether copolymer, and a polyphosphazene.

[0029] In a preferred embodiment, the mass ratio of the hindered amine, the organosilicon polyether copolymer, and the polyphosphazene is (0.1~0.4):(2~3):(4~8).

[0030] In a preferred embodiment, the mass ratio of the hindered amine, the organosilicon polyether copolymer, and the polyphosphazene is (0.2~0.3):(2~2.2):(4.5~5).

[0031] In a preferred embodiment, the lubricant is at least one of zinc stearate, ethylene bis-stearamide, and polyethylene wax.

[0032] In a preferred embodiment, the lubricant is zinc stearate or ethylene bis-stearamide.

[0033] In a preferred embodiment, the lubricant is zinc stearate.

[0034] In a preferred embodiment, the colorant is carbon black or titanium dioxide.

[0035] In a preferred embodiment, the colorant is carbon black.

[0036] A method for preparing an environmentally friendly heat-insulating automotive interior material includes the following steps: S1: Low-density polyethylene, POE elastomer, and composite flame retardant are premixed in a twin-screw mixer at 110-120℃ for 4-5 minutes at a speed of 150-200 rpm, then cooled to 85-90℃. After adding polyester functional resin, the mixture is mixed at a low speed of 80-100 rpm for 3-4 minutes; S2: A foaming agent and crosslinking agent are added, and the mixture is mixed at 60-80 rpm for 3-5 minutes under nitrogen protection, with the temperature controlled ≤ 55℃, then add the remaining raw materials and mix evenly; S3: Extrude and granulate in an extruder at 90~100℃ in zone 1, 130~140℃ in zone 2, 150~160℃ in zone 3, and 115~120℃ at the die. Then preheat at 130~140℃ for 2~3 minutes, raise the temperature to 185~195℃ for 30~40 seconds, maintain the foaming ratio at 15~40 times, then immediately cool down to 160~170℃ and hold for 2~3 minutes. Finally, gradually cool down to 55~60℃ to obtain the final product.

[0037] This application has practical significance and beneficial effects:

[0038] 1. The environmentally friendly and heat-insulating automotive interior material finally obtained in this application not only has excellent environmental protection and heat insulation properties, but also maintains good durability, heat resistance, water resistance and corrosion resistance of interior materials under the premise of limited cost. Thus, it can replace ordinary interior materials and meet the multi-functional needs of the current automotive industry and consumers for such materials.

[0039] 2. The core advantage of the environmentally friendly heat-insulating automotive interior material finally obtained in this application lies in its ability to effectively balance the performance contradictions of traditional materials while maintaining excellent heat insulation, water resistance, corrosion resistance and mechanical strength. It also successfully takes into account the requirements of high flame retardancy and environmental protection, greatly satisfying the environmental requirements of this type of material. Moreover, the material has a long service life and does not need to be replaced frequently, effectively avoiding the usage dilemma for consumers. Its excellent overall performance makes it particularly suitable for promotion and use in private cars, public transportation vehicles and other public transportation vehicles.

[0040] 3. The environmentally friendly heat-insulating automotive interior material finally obtained in this application can be used as an automotive interior component to create a high-end interior space, improve the sound insulation, heat insulation, waterproof performance and comfort of the car, and can be effectively applied to automotive door panels, headliners, dashboards, seats, sun visors, carpets, floor mats, luggage compartment interiors and other materials, and can also be used for heat insulation of bus air conditioning and wiring protection and decorative materials for various vehicles. Attached Figure Description

[0041] Figure 1 This is a physical image of the environmentally friendly heat-insulating automotive interior material prepared according to Example 1 of this application.

[0042] Figures 2-5 This is a diagram showing the flame retardant test results of the environmentally friendly heat-insulating automotive interior material prepared in Example 1 of this application. Detailed Implementation

[0043] Example 1

[0044] The environmentally friendly heat-insulating automotive interior material, by weight, comprises the following raw materials: 52.5 parts low-density polyethylene, 20 parts polyester functional resin, 26 parts POE elastomer, 8.5 parts foaming agent, 1.4 parts crosslinking agent, 25 parts composite flame retardant, 9.5 parts composite composition, 1.1 parts lubricant, 2 parts zinc oxide, and 1.6 parts colorant.

[0045] The low-density polyethylene has a melt index of 2 g / 10 min, a melt flow rate of 2.16 kg at 190℃, and is grade 2420H, sourced from Sinopec.

[0046] The POE elastomer has an ethylene content of 80 wt%, a melt index of 1.2 g / 10 min (190℃, 2.16 kg), and is brand name Engage-8842, sourced from Dow Chemical Company, USA.

[0047] The preparation method of polyester functional resin, by weight, specifically includes the following steps: S1: Dissolve 12.5 parts of polyester resin in 50 parts of cyclohexanone at 80℃ and purge with nitrogen for 30 min to remove oxygen. Add dropwise a mixture of 2 parts of trifluoroethyl methacrylate and 1 part of N-phenylmaleimide. Add dropwise a solution containing 0.05 parts of dicumyl peroxide and 1 part of cyclohexanone. React at 80℃ for 4 h while stirring at 200 rpm to obtain a prepolymer solution. S2: Heat the prepolymer solution to 110℃, add 1.3 parts of vinyltris(2-methoxyethoxy)silane, stir evenly at 200 rpm, add 0.1 wt% acetic acid (total reactant mass), keep warm for 1.5 h, then add 0.04 wt% dibutyltin dilaurate (total reactant mass), keep warm at 120℃ for 2 h. After completion, recover cyclohexanone. The remaining material is the polyester functional resin.

[0048] The polyester resin has a melt index of 6.5 g / 10 min (203℃, 2.16 kg), grade 5555HS, and is from DuPont, USA.

[0049] The foaming agent is 4,4'-oxobis(benzenesulfonyl)hydrazine; the crosslinking agent is BIPB; the composite flame retardant is a composition of ammonium polyphosphate, magnesium hydroxide, red phosphorus and aluminum hypophosphite in a mass ratio of 11:6:5:3.5.

[0050] The composite composition is a combination of hindered amine Tinuvin® 944, organosilicon polyether copolymer DC-580 and polyphosphazene in a mass ratio of 0.2:2.2:4.5.

[0051] The polyphosphazene is a phenoxy polyphosphazene, produced by Wuhan Smike Biotechnology Co., Ltd., China.

[0052] The lubricant is zinc stearate; the colorant is carbon black.

[0053] The preparation method of environmentally friendly heat-insulating automotive interior materials includes the following steps: S1: Low-density polyethylene, POE elastomer and composite flame retardant are premixed in a twin-screw mixer at 120℃ for 5 minutes at 180 rpm, then cooled to 90℃. After adding polyester functional resin, the mixture is mixed at 90 rpm for 4 minutes. S2: Foaming agent and crosslinking agent are added and mixed at 60 rpm for 5 minutes under nitrogen protection, with the temperature controlled at ≤55℃. Then the remaining raw materials are added and mixed evenly. S3: The mixture is extruded and granulated in an extruder at 100℃ in zone 1, 140℃ in zone 2, 155℃ in zone 3 and 120℃ at the die. After preheating at 135℃ for 3 minutes, the temperature is raised to 190℃ for 35 seconds to foam, maintaining a foaming ratio of 25 times. Then the temperature is immediately lowered to 170℃ and held for 2 minutes. Finally, the temperature is gradually lowered to 55℃ to obtain the final product.

[0054] The actual product of the environmentally friendly heat-insulating automotive interior material obtained in this embodiment is as follows: Figure 1 As shown.

[0055] Example 2

[0056] The only difference between this embodiment and Embodiment 1 is as follows: The environmentally friendly heat-insulating automotive interior material, by weight, comprises the following raw materials: 48 parts low-density polyethylene, 18 parts polyester functional resin, 28 parts POE elastomer, 8.5 parts foaming agent, 1.4 parts crosslinking agent, 25 parts composite flame retardant, 9.5 parts composite composition, 1.1 parts lubricant, 2 parts zinc oxide, and 1.6 parts colorant.

[0057] All other implementation schemes are the same.

[0058] Example 3

[0059] The only difference between this embodiment and Embodiment 1 is as follows: The environmentally friendly heat-insulating automotive interior material, by weight, comprises the following raw materials: 55 parts low-density polyethylene, 20 parts polyester functional resin, 26 parts POE elastomer, 8.5 parts foaming agent, 1.4 parts crosslinking agent, 25 parts composite flame retardant, 8 parts composite composition, 1.1 parts lubricant, 2 parts zinc oxide, and 1.6 parts colorant.

[0060] All other implementation schemes are the same.

[0061] Comparative Example 1

[0062] The only difference between this comparative example and Example 1 is as follows: the environmentally friendly heat-insulating automotive interior material, by weight, comprises: 67.5 parts low-density polyethylene, 5 parts polyester functional resin, 26 parts POE elastomer, 8.5 parts foaming agent, 1.4 parts crosslinking agent, 25 parts composite flame retardant, 9.5 parts composite composition, 1.1 parts lubricant, 2 parts zinc oxide, and 1.6 parts colorant.

[0063] All other implementation schemes are the same.

[0064] Comparative Example 2

[0065] The only difference between this comparative example and Example 1 is as follows: the environmentally friendly heat-insulating automotive interior material, by weight, comprises: 60 parts of low-density polyethylene, 20 parts of polyester functional resin, 26 parts of POE elastomer, 8.5 parts of foaming agent, 1.4 parts of crosslinking agent, 25 parts of composite flame retardant, 2.5 parts of composite composition, 1.1 parts of lubricant, 2 parts of zinc oxide, and 1.6 parts of colorant.

[0066] All other implementation schemes are the same.

[0067] Comparative Example 3

[0068] The only difference between this comparative example and Example 1 is as follows: The preparation method of the polyester functional resin, by mass, specifically includes the following steps: S1: 12.5 parts of polyester resin are dissolved in 50 parts of cyclohexanone at 80°C and nitrogen gas is passed through for 30 min to remove oxygen. A mixture of 0.5 parts of trifluoroethyl methacrylate and 2.5 parts of N-phenylmaleimide is added dropwise. A solution containing 0.05 parts of dicumyl peroxide and 1 part of cyclohexanone is added dropwise. The mixture is reacted at 80°C for 4 h while stirring at 200 rpm to obtain a prepolymer solution; S2: The prepolymer solution is heated to 110°C, and 0.2 parts of vinyltris(2-methoxyethoxy)silane are added. After stirring evenly at 200 rpm, 0.1 wt% acetic acid is added according to the total reactant mass. The mixture is kept at this temperature for 1.5 h. Then, 0.04 wt% dibutyltin dilaurate is added according to the total reactant mass. The mixture is kept at 120°C for 2 h. After completion, cyclohexanone is recovered, and the remaining material is the polyester functional resin.

[0069] All other implementation schemes are the same.

[0070] Comparative Example 4

[0071] The only difference between this comparative example and Example 1 is as follows: The preparation method of the polyester functional resin, by mass, specifically includes the following steps: S1: 20.5 parts of polyester resin are dissolved in 50 parts of cyclohexanone at 80°C and nitrogen gas is passed through for 30 min to remove oxygen. A mixture of 4 parts of trifluoroethyl methacrylate and 0.2 parts of N-phenylmaleimide is added dropwise. A solution containing 0.05 parts of dicumyl peroxide and 1 part of cyclohexanone is added dropwise. The mixture is reacted at 80°C for 4 h while stirring at 200 rpm to obtain a prepolymer solution; S2: The prepolymer solution is heated to 110°C, 0.8 parts of vinyltris(2-methoxyethoxy)silane are added, and the mixture is stirred evenly at 200 rpm. Then, 0.1 wt% acetic acid is added based on the total reactant mass, and the mixture is kept at this temperature for 1.5 h. Then, 0.04 wt% dibutyltin dilaurate is added based on the total reactant mass, and the mixture is kept at 120°C for 2 h. After completion, cyclohexanone is recovered, and the remaining material is the polyester functional resin.

[0072] All other implementation schemes are the same.

[0073] Comparative Example 5

[0074] The only difference between this comparative example and Example 1 is that the composite composition is a combination of hindered amine Tinuvin® 944, organosilicon polyether copolymer DC-580 and polyphosphazene in a mass ratio of 0.2:0.5:8.

[0075] All other implementation schemes are the same.

[0076] Comparative Example 6

[0077] The only difference between this comparative example and Example 1 is that the composite composition is a combination of hindered amine Tinuvin® 944, organosilicon polyether copolymer DC-580 and polyphosphazene in a mass ratio of 0.2:5:2.

[0078] All other implementation schemes are the same.

[0079] Performance testing

[0080] 1. The elongation at break test shall be performed in accordance with the standard GBT6344. The transverse elongation at break shall be recorded and the average value of 10 tests shall be recorded in Table 1.

[0081] 2. The tear strength test shall be performed in accordance with the standard GBT10808. The transverse tear strength shall be recorded and the average value of 10 tests shall be recorded in Table 1.

[0082] 3. The thermal conductivity test shall be performed in accordance with the standard GBT3399, and the average value of 10 tests shall be recorded in Table 1.

[0083] 4. Waterproofing - water absorption rate test reference standard GBT8810, and the result is the average of 10 tests recorded in Table 1.

[0084] 5. The compression set test shall be performed in accordance with standard GB / T 6669. The average value of 10 tests shall be recorded in Table 1.

[0085] 6. Corrosion resistance test: Prepare 50 mm × 25 mm × 5 mm material samples, vacuum dry at 60℃ for 24 h, and then cool to room temperature (23~26℃). Then, completely immerse the test samples in 10 wt% sodium hydroxide solution for 720 h and 50 wt% ethylene glycol solution for 360 h. After immersion, observe whether the surface of the sample is still smooth and undamaged (10 wt% sodium hydroxide solution) and whether there is edge warping (50 wt% ethylene glycol solution). The results are recorded in Table 1.

[0086] 7. The flame retardant test report of the environmentally friendly heat-insulating automotive interior material prepared in Example 1 is as follows: Figures 2-5 As shown.

[0087] Table 1 Performance Test Results

[0088]

[0089] Based on the final performance test results of the examples and comparative examples, comparative examples 1 and 2 did not use the correct ratio of raw materials for polyester functional resin and composite composition, resulting in lower performance than the examples in the corresponding tests.

[0090] Comparative Examples 3 to 6, on the other hand, did not use the raw material ratio scheme of the composite composition specified in this application and did not prepare the polyester functional resin according to the specified method, which resulted in a significant decrease in its effect in the system and ultimately a significant decrease in its overall performance.

Claims

1. An environmentally friendly heat-insulating automotive interior material, characterized in that: By weight, the raw materials include: 40-60 parts of low-density polyethylene, 15-30 parts of polyester functional resin, 20-30 parts of POE elastomer, 5-15 parts of foaming agent, 0.5-2 parts of crosslinking agent, 20-35 parts of composite flame retardant, 5-12 parts of composite composition, 0.5-2 parts of lubricant, 1-3 parts of zinc oxide, and 1-3 parts of colorant; The preparation method of the polyester functional resin includes: S1: dissolving the polyester resin in a solvent and purging with nitrogen to remove oxygen, adding a mixture of trifluoroethyl methacrylate and N-phenylmaleimide dropwise, adding dicumyl peroxide solution dropwise, reacting and stirring to obtain a prepolymer; S2: heating the prepolymer, adding vinyltris(2-methoxyethoxy)silane, stirring, adding acetic acid and maintaining the temperature for reaction, adding dibutyltin dilaurate, maintaining the temperature for reaction, recovering cyclohexanone after completion, and obtaining the remaining material. The mass ratio of the polyester resin, trifluoroethyl methacrylate, N-phenylmaleimide, and vinyltris(2-methoxyethoxy)silane is (12~15):(1.5~2.5):(0.8~1.6):(1~1.4). The polyester resin has a melt index of 6.5 g / 10 min, 203 °C, and a yield of 2.16 kg, and its grade is 5555HS. The mass ratio of the low-density polyethylene to the composite composition is (4.5~6):(0.6~1). The composite composition is a combination of hindered amine, organosilicon polyether copolymer and polyphosphazene, in a mass ratio of (0.1~0.4):(2~3):(4~8).

2. The environmentally friendly heat-insulating automotive interior material according to claim 1, characterized in that: The mass ratio of the low-density polyethylene, polyester functional tree and POE elastomer is (4.5~6):(1.8~2.5):(2.5~3).

3. The environmentally friendly heat-insulating automotive interior material according to claim 2, characterized in that: The foaming agent is at least one of azodicarbonamide, 4,4'-oxobis(benzenesulfonylhydrazine) and sodium bicarbonate.

4. The environmentally friendly heat-insulating automotive interior material according to claim 3, characterized in that: The POE elastomer has an ethylene content of 70-85 wt%, a melt index of 1-1.5 g / 10 min, a melting point of 190℃, and a yield of 2.16 kg.

5. The environmentally friendly heat-insulating automotive interior material according to claim 4, characterized in that: The crosslinking agent is at least one of dicumyl peroxide, tert-butyl peroxide, dicyclohexyl peroxide, and BIPB.

6. The environmentally friendly heat-insulating automotive interior material according to claim 5, characterized in that: The composite flame retardant is a composition of ammonium polyphosphate, magnesium hydroxide, red phosphorus and aluminum hypophosphite, in a mass ratio of (10~14):(6~8):(6~8):(3~5).

7. A method for preparing an environmentally friendly heat-insulating automotive interior material according to any one of claims 1 to 6, characterized in that: Specifically, the following steps are included: S1: Premix low-density polyethylene, POE elastomer, and composite flame retardant in a twin-screw mixer at 110-120℃ for 4-5 minutes at a speed of 150-200 rpm, then cool to 85-90℃. After adding the polyester functional resin, mix at a low speed of 80-100 rpm for 3-4 minutes. S2: Add the foaming agent and crosslinking agent and mix at 60-80 rpm for 3-5 minutes under nitrogen protection, controlling the temperature to ≤55℃. Then add the remaining raw materials. Mix evenly; S3: Extrude and granulate in an extruder at 90~100℃ in zone 1, 130~140℃ in zone 2, 150~160℃ in zone 3, and 115~120℃ at the die. Then preheat at 130~140℃ for 2~3 minutes, raise the temperature to 185~195℃ for 30~40 seconds, maintain the foaming ratio at 15~40 times, then immediately cool down to 160~170℃ and hold for 2~3 minutes. Finally, gradually cool down to 55~60℃ to obtain the final product.

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