Low-voc tpe material special for automotive interior and preparation method thereof

Abstract

The application discloses a kind of low VOC special TPE materials of automotive interior and preparation method thereof, belong to high polymer composite material technical field.The material is with SEBS as base material, cooperate reactive plasticizer, Meso-tetramethyl-meso-tetra-p-aminobenzyl cup [4] pyrrole, allyl β-cyclodextrin and other functional additives compound is formed;Its preparation method includes SEBS pre-baking, each component high-speed mixing, co-rotating twin-screw extrusion and other steps, extrusion process is accurately temperature-controlled by multi-temperature zone, combined with supercritical CO2 One-stage devolatilization and double-stage vacuum devolatilization process realizes high-efficiency VOC removal.The application is by component synergy and process optimization, so that material has low VOC release, low odor, excellent mechanical property and long-term stability, adapts to the stringent requirements of automotive interior material.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, and in particular to a low-VOC TPE material for automotive interiors and its preparation method. Background Technology

[0002] Thermoplastic elastomers (TPEs) combine the elasticity of rubber with the processability of plastics, offering advantages such as lightweight, recyclability, and a soft touch. They are widely used in automotive interiors and are a key material for achieving high-end and environmentally friendly automotive interiors. With the rapid development of the automotive industry and the increasing health awareness of consumers, in-vehicle air quality has become a focus of attention. Volatile organic compounds (VOCs), as a major factor affecting in-vehicle air quality, are subject to strict control over their release. Therefore, developing low-VOC, low-odor TPE materials specifically for automotive interiors has become an inevitable trend in the industry.

[0003] Traditional low-VOC TPE materials for automotive interiors are mostly simple additions of single adsorbent materials. These materials not only exhibit poor selectivity for both polar VOCs (such as formaldehyde and acetaldehyde) and non-polar VOCs (such as benzene and toluene), but also are prone to adsorption saturation, leading to insufficient long-term VOC release stability. This is especially problematic in the long-term high-temperature environment of automotive interiors, where adsorbed VOCs are easily desorbed and re-pollute the air inside the vehicle. Furthermore, there are bottlenecks in controlling the compatibility between the added adsorbent material and the TPE matrix. Increasing the amount of adsorbent to improve VOC removal efficiency severely damages the phase interface of the matrix, resulting in a significant decrease in the material's tensile strength, elongation at break, and other mechanical properties, failing to meet the dynamic usage requirements of automotive interior components. The manufacturing processes of commercially available low-VOC automotive interior TPE materials lack comprehensive control over the entire chain of VOC "source inhibition - process removal - terminal locking." Simply reducing VOCs through raw material screening or a single drying step fails to address the secondary VOC generation problems caused by component degradation and plasticizer migration during processing. These underlying issues prevent existing low-VOC TPE materials from simultaneously achieving environmental friendliness, mechanical properties, and long-term service stability, thus limiting their application in high-end new energy vehicle interiors.

[0004] To address the aforementioned issues, invention patent application CN117700875A discloses a TPE composite material capable of releasing negative oxygen ions and its preparation method. This invention proposes a TPE composite material capable of releasing negative oxygen ions, comprising the following raw materials in parts by weight: 20-50 parts of styrene-based thermoplastic elastomer; 15-30 parts of thermoplastic vulcanized rubber; 10-30 parts of polypropylene; 5-15 parts of polyolefin elastomer; 1-10 parts of negative ion additive; 0.1-0.5 parts of peroxide crosslinking agent; and 1-2 parts of slip agent. The TPE composite material provided by this invention not only possesses ultra-high fluidity but also releases a large amount of negative oxygen ions, effectively reducing VOCs and providing efficient sterilization. However, its peroxide crosslinking agent easily leads to a decrease in material toughness, and the negative ion additive has poor compatibility with the matrix, making it prone to precipitation with long-term use, thus making it difficult to guarantee the stability of VOC removal efficiency.

[0005] It is evident that the development of a TPE material specifically for automotive interiors, which combines high efficiency, long-lasting low VOC performance, excellent mechanical properties, and stable service capability, as well as its preparation method, is urgently needed. Summary of the Invention

[0006] To address the shortcomings of existing automotive interior TPE materials, such as high VOC emissions, difficulty in achieving both low VOC performance and mechanical properties, and unstable preparation processes, this invention provides a low-VOC automotive interior-specific TPE material and its preparation method. By optimizing component design and preparation process, it achieves precise VOC control and synergistic improvement in mechanical properties, meeting the stringent environmental protection and usage requirements of automotive interiors.

[0007] To achieve the above objectives, the present invention provides a low-VOC automotive interior TPE material, which, by weight, comprises the following components: 100 parts of SEBS, 10-15 parts of reactive plasticizer, 3-5 parts of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole, 3-5 parts of allyl β-cyclodextrin, 0.5-1 parts of dicumyl peroxide, 0.8-1.5 parts of functional additives, 0.8-1.2 parts of phenolic resin, 0.5-0.8 parts of vulcanization accelerator, 0.3-0.5 parts of coupling agent, and 3-5 parts of nano molecular sieve.

[0008] Preferably, the SEBS grade is 9901.

[0009] Preferably, the reactive plasticizer is epoxidized soybean oil acrylate.

[0010] Preferably, the preparation method of the Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole is described in: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and characterization of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole [J]. Chemical Reagents, 2002(6):344-345.

[0011] Preferably, the functional additive is a compound of antioxidant, light stabilizer and lubricant in a mass ratio of 1:(0.8-1.2):(0.5-0.8).

[0012] Preferably, the antioxidant is at least one of antioxidant 1010 and antioxidant 168.

[0013] Preferably, the light stabilizer is hindered amine light stabilizer HS-944.

[0014] Preferably, the lubricant is zinc stearate.

[0015] Preferably, the phenolic resin is 2123 phenolic resin; and the vulcanization accelerator is 2-mercaptobenzothiazole zinc salt.

[0016] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0017] Preferably, the nano molecular sieve is a nano ZSM-5 molecular sieve.

[0018] Another object of the present invention is to provide a method for preparing the low-VOC automotive interior-specific TPE material, comprising the following steps: Step S1, Pre-drying: Place SEBS in a vacuum oven at 78-82℃ and dry for 4-6 hours; Step S2, high-speed mixing: Add each component to a high-speed mixer according to the weight parts, and mix at 800-1200 rpm for 8-12 minutes to obtain a mixture. Step S3, Extrusion: The mixture is extruded using a co-rotating twin-screw extruder, and after washing and drying, a low-VOC TPE material for automotive interiors is obtained.

[0019] Preferably, in step S3, the twin-screw extruder is configured with ten temperature zones along the material feed direction, with the following temperatures: Zone 1 158-162℃, Zone 2 178-182℃, Zone 3 188-192℃, Zone 4 198-202℃, Zone 5 198-202℃, Zone 6 193-197℃, Zone 7 188-192℃, Zone 8 183-187℃, Zone 9 178-182℃, and Zone 10 173-178℃; the screw speed is 340-380 rpm, and supercritical CO2 is injected in Zone 8 of the screw for primary devolatilization; Zone 9 is equipped with a dual-stage vacuum port with a vacuum degree ≤-0.095 MPa and a residence time of 45 s.

[0020] Preferably, the flow rate of the supercritical CO2 is 3wt%-5wt% of the material mass flow rate.

[0021] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The low-VOC automotive interior TPE material disclosed in this invention uses the synergistic effect of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole and allyl β-cyclodextrin. The amino group in the calix[4]pyrrole molecule can irreversibly chemically combine with polar VOCs such as formaldehyde and acetaldehyde to form a stable Schiff base structure to achieve permanent locking. The hydrophobic cavity of allyl β-cyclodextrin can accurately encapsulate non-polar VOCs such as benzene and toluene through host-guest recognition. Combined with the high specific surface area physical adsorption of nano ZSM-5 molecular sieve, a triple VOC removal system of "chemical locking-cavity encapsulation-physical adsorption" is constructed, which completely solves the defects of the existing technology that the VOC removal effect is effective in the short term but easy to rebound in the long term.

[0022] (2) The low-VOC automotive interior TPE material disclosed in this invention uses reactive plasticizer epoxidized soybean oil acrylate. Its active groups in the molecular structure can interact with SEBS and phenolic resin to fix the plasticizer molecules in the matrix, which not only avoids the secondary pollution of VOC caused by the migration and precipitation of traditional plasticizers, but also improves the compatibility between components. By precisely controlling the component ratio and component compatibility, the synergistic optimization of low VOC performance and excellent mechanical properties is achieved, which fully meets the dynamic use requirements of automotive interior parts.

[0023] (3) The low-VOC automotive interior TPE material disclosed in this invention constructs a full-chain VOC control system of "pre-baking and impurity removal - reaction locking - precise devolatilization". The vacuum pre-baking in step S1 can remove the moisture and trace volatiles adsorbed in SEBS in advance, reducing the source of VOC from the source. The specific gradient temperature zone design in step S3 ensures that the components react and mix fully, and avoids the generation of VOC by high-temperature degradation. The supercritical CO2 primary devolatilization in zone 8 can efficiently extract unreacted small molecule VOCs in the melt. Combined with the dual-stage high vacuum devolatilization in zone 9 (vacuum degree ≤ -0.095MPa), the residual VOCs are further removed in depth. Compared with the traditional single drying or vacuum devolatilization process, the residual VOCs are significantly reduced, and the problem of secondary VOC generation caused by component degradation and plasticizer migration in the existing preparation process is completely solved.

[0024] (4) The low-VOC automotive interior TPE material disclosed in this invention forms an all-round functional protection system by compounding antioxidants, hindered amine light stabilizer HS-944 and lubricant zinc stearate, which can effectively inhibit the oxidation aging and degradation of the material under service environments such as light and high temperature; at the same time, each component exists stably in the matrix through chemical bonding or strong interfacial interaction, avoiding the defects of traditional negative ion additives and adsorbents that are easy to precipitate. Detailed Implementation

[0025] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0026] Example 1: A low-VOC automotive interior TPE material, by weight, includes the following components: 100 parts SEBS, 10 parts reactive plasticizer, 3 parts Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole, 3 parts allyl β-cyclodextrin, 0.5 parts dicumyl peroxide, 0.8 parts functional additives, 0.8 parts phenolic resin, 0.5 parts vulcanization accelerator, 0.3 parts coupling agent, and 3 parts nano molecular sieve.

[0027] The SEBS grade is 9901; the reactive plasticizer is epoxidized soybean oil acrylate; the preparation method of the Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole is described in: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and characterization of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole [J]. Chemical Reagents, 2002(6):344-345; the functional additive is a mixture of antioxidant, light stabilizer and lubricant in a mass ratio of 1:0.8:0.5; the antioxidant is antioxidant 1010; the light stabilizer is hindered amine light stabilizer HS-944; the lubricant is zinc stearate; the phenolic resin is 2123 phenolic resin; the vulcanization accelerator is 2-mercaptobenzothiazole zinc salt; the coupling agent is silane coupling agent KH550; the nano molecular sieve is nano ZSM-5 molecular sieve.

[0028] A method for preparing the low-VOC automotive interior-specific TPE material includes the following steps: Step S1, Pre-drying: Place SEBS in a vacuum oven at 78℃ and dry for 4 hours; Step S2, High-speed mixing: Add each component to a high-speed mixer according to the weight parts, mix at 800 rpm for 8 minutes to obtain a mixture; Step S3, Extrusion: The mixture is extruded using a co-rotating twin-screw extruder, and after washing and drying, a low-VOC TPE material for automotive interiors is obtained.

[0029] In step S3, the twin-screw extruder is equipped with ten temperature zones along the material feed direction, with the following temperatures: Zone 1 158℃, Zone 2 178℃, Zone 3 188℃, Zone 4 198℃, Zone 5 198℃, Zone 6 193℃, Zone 7 188℃, Zone 8 183℃, Zone 9 178℃, and Zone 10 173℃. The screw speed is 340 rpm. Supercritical CO2 is injected into Zone 8 of the screw for primary devolatilization. Zone 9 is equipped with a dual-stage vacuum port with a vacuum degree ≤ -0.095 MPa and a residence time of 45 s. The flow rate of the supercritical CO2 is 3 wt% of the material mass flow rate.

[0030] Example 2: A low-VOC automotive interior TPE material, by weight, includes the following components: 100 parts SEBS, 11 parts reactive plasticizer, 3.5 parts Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole, 3.5 parts allyl β-cyclodextrin, 0.6 parts dicumyl peroxide, 1 part functional additive, 0.9 parts phenolic resin, 0.6 parts vulcanization accelerator, 0.35 parts coupling agent, and 3.5 parts nano molecular sieve.

[0031] The SEBS grade is 9901; the reactive plasticizer is epoxidized soybean oil acrylate; the preparation method of the Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole is described in: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and characterization of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole [J]. Chemical Reagents, 2002(6):344-345; the functional additive is a compound of antioxidant, light stabilizer and lubricant in a mass ratio of 1:0.9:0.6; the antioxidant is antioxidant 168; the light stabilizer is hindered amine light stabilizer HS-944; the lubricant is zinc stearate; the phenolic resin is 2123 phenolic resin; the vulcanization accelerator is 2-mercaptobenzothiazole zinc salt; the coupling agent is silane coupling agent KH560; the nano molecular sieve is nano ZSM-5 molecular sieve.

[0032] Another object of the present invention is to provide a method comprising the following steps: Step S1, Pre-drying: Place SEBS in a vacuum oven at 79℃ and dry for 4.5 hours; Step S2, high-speed mixing: Add each component to a high-speed mixer according to the weight parts, mix at 900 rpm for 9 minutes to obtain a mixture; Step S3, Extrusion: The mixture is extruded using a co-rotating twin-screw extruder, and after washing and drying, a low-VOC TPE material for automotive interiors is obtained.

[0033] In step S3, the twin-screw extruder is equipped with ten temperature zones along the material feed direction, with the following temperatures: Zone 1 159℃, Zone 2 179℃, Zone 3 189℃, Zone 4 199℃, Zone 5 199℃, Zone 6 194℃, Zone 7 189℃, Zone 8 184℃, Zone 9 179℃, and Zone 10 174℃. The screw speed is 350 rpm. Supercritical CO2 is injected into Zone 8 of the screw for primary devolatilization. Zone 9 is equipped with a dual-stage vacuum port with a vacuum degree ≤ -0.095 MPa and a residence time of 45 s. The flow rate of the supercritical CO2 is 3.5 wt% of the material mass flow rate.

[0034] Example 3: A low-VOC automotive interior TPE material, by weight, includes the following components: 100 parts of SEBS, 13 parts of reactive plasticizer, 4 parts of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole, 4 parts of allyl β-cyclodextrin, 0.8 parts of dicumyl peroxide, 1.2 parts of functional additives, 1 part of phenolic resin, 0.65 parts of vulcanization accelerator, 0.4 parts of coupling agent, and 4 parts of nano molecular sieve.

[0035] The SEBS grade is 9901; the reactive plasticizer is epoxidized soybean oil acrylate; the preparation method of the Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole is described in: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and characterization of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole [J]. Chemical Reagents, 2002(6):344-345; the functional additive is a mixture of antioxidant, light stabilizer and lubricant in a mass ratio of 1:1:0.65; the antioxidant is antioxidant 1010; the light stabilizer is hindered amine light stabilizer HS-944; the lubricant is zinc stearate; the phenolic resin is 2123 phenolic resin; the vulcanization accelerator is 2-mercaptobenzothiazole zinc salt; the coupling agent is silane coupling agent KH570; the nano molecular sieve is nano ZSM-5 molecular sieve.

[0036] A method for preparing the low-VOC automotive interior-specific TPE material includes the following steps: Step S1, Pre-drying: Place SEBS in a vacuum oven at 80℃ and dry for 5 hours; Step S2, high-speed mixing: Add each component to a high-speed mixer according to the weight parts, mix at 1000 rpm for 10 minutes to obtain a mixture; Step S3, Extrusion: The mixture is extruded using a co-rotating twin-screw extruder, and after washing and drying, a low-VOC TPE material for automotive interiors is obtained.

[0037] In step S3, the twin-screw extruder is configured with ten temperature zones along the material feed direction, with the following temperatures: Zone 1 160℃, Zone 2 180℃, Zone 3 190℃, Zone 4 200℃, Zone 5 200℃, Zone 6 195℃, Zone 7 190℃, Zone 8 185℃, Zone 9 180℃, and Zone 10 175℃. The screw speed is 360 rpm. Supercritical CO2 is injected into Zone 8 for primary devolatilization. Zone 9 is equipped with a dual-stage vacuum port with a vacuum degree ≤ -0.095 MPa and a residence time of 45 s. The flow rate of the supercritical CO2 is 4 wt% of the material mass flow rate. Example 4: A low-VOC automotive interior TPE material, by weight, includes the following components: 100 parts of SEBS, 14 parts of reactive plasticizer, 4.5 parts of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole, 4.5 parts of allyl β-cyclodextrin, 0.9 parts of dicumyl peroxide, 1.3 parts of functional additives, 1.1 parts of phenolic resin, 0.75 parts of vulcanization accelerator, 0.45 parts of coupling agent, and 4.5 parts of nano molecular sieve.

[0038] The SEBS grade is 9901; the reactive plasticizer is epoxidized soybean oil acrylate; the preparation method of the Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole is described in: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and characterization of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole [J]. Chemical Reagents, 2002(6):344-345; The functional additives are antioxidants, light stabilizers and lubricants compounded in a mass ratio of 1:1.1:0.75; The antioxidants are antioxidant 1010 and antioxidant 168 compounded in a mass ratio of 3:5; The light stabilizer is hindered amine light stabilizer HS-944; The lubricant is zinc stearate; The phenolic resin is 2123 phenolic resin; The vulcanization accelerator is 2-mercaptobenzothiazole zinc salt; The coupling agent is silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570 compounded in a mass ratio of 1:2:3; The nano molecular sieve is nano ZSM-5 molecular sieve.

[0039] A method for preparing the low-VOC automotive interior-specific TPE material includes the following steps: Step S1, Pre-drying: Place SEBS in a vacuum oven at 81℃ and dry for 5.5 hours; Step S2, high-speed mixing: Add each component to a high-speed mixer according to the weight parts, mix at 1100 rpm for 11 min to obtain a mixture; Step S3, Extrusion: The mixture is extruded using a co-rotating twin-screw extruder, and after washing and drying, a low-VOC TPE material for automotive interiors is obtained.

[0040] In step S3, the twin-screw extruder is equipped with ten temperature zones along the material feed direction, with the following temperatures: Zone 1 161℃, Zone 2 181℃, Zone 3 191℃, Zone 4 201℃, Zone 5 201℃, Zone 6 196℃, Zone 7 191℃, Zone 8 186℃, Zone 9 181℃, and Zone 10 177℃. The screw speed is 370 rpm. Supercritical CO2 is injected into Zone 8 of the screw for primary devolatilization. Zone 9 is equipped with a dual-stage vacuum port with a vacuum degree ≤ -0.095 MPa and a residence time of 45 s. The flow rate of the supercritical CO2 is 4.5 wt% of the material mass flow rate.

[0041] Example 5 A low-VOC automotive interior TPE material, by weight, includes the following components: 100 parts SEBS, 15 parts reactive plasticizer, 5 parts Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole, 5 parts allyl β-cyclodextrin, 1 part dicumyl peroxide, 1.5 parts functional additives, 1.2 parts phenolic resin, 0.8 parts vulcanization accelerator, 0.5 parts coupling agent, and 5 parts nano molecular sieve.

[0042] The SEBS grade is 9901; the reactive plasticizer is epoxidized soybean oil acrylate; the preparation method of the Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole is described in: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and characterization of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole [J]. Chemical Reagents, 2002(6):344-345; The functional additives are antioxidants, light stabilizers and lubricants compounded in a mass ratio of 1:1.2:0.8; The antioxidants are antioxidant 1010 and antioxidant 168 compounded in a mass ratio of 1:3; The light stabilizer is hindered amine light stabilizer HS-944; The lubricant is zinc stearate; The phenolic resin is 2123 phenolic resin; The vulcanization accelerator is 2-mercaptobenzothiazole zinc salt; The coupling agent is silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570 compounded in a mass ratio of 1:2:1; The nano molecular sieve is nano ZSM-5 molecular sieve.

[0043] A method for preparing the low-VOC automotive interior-specific TPE material includes the following steps: Step S1, Pre-drying: Place SEBS in a vacuum oven at 82℃ and dry for 6 hours; Step S2, high-speed mixing: Add each component to a high-speed mixer according to the weight parts, mix at 1200 rpm for 12 minutes to obtain a mixture; Step S3, Extrusion: The mixture is extruded using a co-rotating twin-screw extruder, and after washing and drying, a low-VOC TPE material for automotive interiors is obtained.

[0044] In step S3, the twin-screw extruder is equipped with ten temperature zones along the material feed direction, with the following temperatures: Zone 1 162℃, Zone 2 182℃, Zone 3 192℃, Zone 4 202℃, Zone 5 202℃, Zone 6 197℃, Zone 7 192℃, Zone 8 187℃, Zone 9 182℃, and Zone 10 178℃. The screw speed is 380 rpm. Supercritical CO2 is injected into Zone 8 of the screw for primary devolatilization. Zone 9 is equipped with a dual-stage vacuum port with a vacuum degree ≤ -0.095 MPa and a residence time of 45 s. The flow rate of the supercritical CO2 is 5 wt% of the material mass flow rate.

[0045] Comparative Example 1 A low-VOC automotive interior TPE material and its preparation method are basically the same as those in Example 5, except that an equal amount of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole is used instead of allyl β-cyclodextrin.

[0046] Comparative Example 2 A low-VOC automotive interior TPE material and its preparation method are basically the same as those in Example 5, except that an equal amount of allyl β-cyclodextrin is used instead of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole.

[0047] Comparative Example 3 A low-VOC TPE material for automotive interiors and its preparation method are basically the same as those in Example 5, except that no phenolic resin and vulcanization accelerator are added.

[0048] Comparative Example 4 A low-VOC TPE material for automotive interiors and its preparation method are basically the same as those in Example 5, except that the supercritical CO2 injection step is not included.

[0049] To further illustrate the beneficial technical effects of the low-VOC automotive interior TPE material involved in the embodiments of the present invention, relevant performance tests were conducted on the low-VOC automotive interior TPE materials involved in Example 5 and Comparative Examples 1-4. The test results are shown in Table 1, and the test methods are as follows: VOC content: Referring to GB / T 42704-2023 "Determination of Volatile Organic Compounds in Textile Materials for Automotive Interiors - Chamber Method", a 1m³ test chamber was used, with a temperature of 65℃, relative humidity of 5%, gas exchange rate of 0.4m³ / h, and product loading rate of 0.4m² / m³. Sampling was performed after equilibration for 12 hours. VOCs were collected using Tenax tubes, and aldehydes and ketones were collected using DNPH tubes. Qualitative and quantitative analyses were performed by GC-MS and HPLC, respectively. TVOC was defined as the sum of volatile organic compounds with retention times between n-hexane and n-hexadecane.

[0050] Long-term stability test: After aging the sample in an 80℃ oven for 1000h, repeat the above VOC content detection steps and calculate the increase in TVOC release after aging.

[0051] Odor rating: In accordance with VDA 270 standard, the sample was placed in an 80℃ oven and heated for 2 hours. A 5-person evaluation team scored the odor level (1 point for no noticeable odor, 6 points for unacceptable odor), and the average value was taken.

[0052] Mechanical property testing: Refer to GB / T 1040.1-2006 "Determination of tensile properties of plastics - Part 1: General rules", use type A specimens, tensile speed 50 mm / min, and test tensile strength.

[0053] Table 1 shows that the low-VOC automotive interior TPE material of Example 5 is significantly better than the comparative examples in all aspects of performance. Its TVOC (65 μg / m³), formaldehyde (3.0 μg / m³), and toluene (8.5 μg / m³) content is the lowest, the odor level is only 1.2 points (which meets the rule of the average of 5 people's integer scores), the tensile strength reaches 19.3 MPa, and the TVOC increase after long-term aging is only 8.7%. In contrast, comparative examples 1-2 have problems of increased VOC content and deteriorated odor level due to the lack of synergistic effect of calix[4]pyrrole and allyl β-cyclodextrin, comparative example 3 has no phenolic resin and vulcanization accelerator, and comparative example 4 has canceled the supercritical CO2 devolatilization process. Among them, the TVOC content of comparative example 4 reaches 212 μg / m³ and the odor level is 4.2 points, and the tensile strength of comparative example 3 is only 10.8 MPa, which fully verifies the rationality and superiority of the component combination and preparation process of Example 5.

[0054] Table 1 Performance test results of low-VOC automotive interior TPE materials project TVOC (μg / m³) Formaldehyde (μg / m³) Toluene (μg / m³) Odor rating (points) Tensile strength (MPa) TVOC growth rate (%) Example 5 65 3.0 8.5 1.2 19.3 8.7 Comparative Example 1 102 4.8 15.2 2.2 16.5 15.3 Comparative Example 2 98 4.5 14.8 2.0 16.2 14.8 Comparative Example 3 185 8.2 28.6 3.4 10.8 32.6 Comparative Example 4 212 9.5 32.1 4.2 18.8 28.5 The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A low-VOC TPE material specifically for automotive interiors, characterized in that, By weight, it includes the following components: 100 parts SEBS, 10-15 parts reactive plasticizer, 3-5 parts Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole, 3-5 parts allyl β-cyclodextrin, 0.5-1 parts dicumyl peroxide, 0.8-1.5 parts functional additives, 0.8-1.2 parts phenolic resin, 0.5-0.8 parts vulcanization accelerator, 0.3-0.5 parts coupling agent, and 3-5 parts nano molecular sieve.

2. The low-VOC automotive interior-specific TPE material according to claim 1, characterized in that, The SEBS grade is 9901.

3. The low-VOC automotive interior-specific TPE material according to claim 1, characterized in that, The reactive plasticizer is epoxidized soybean oil acrylate.

4. The low-VOC automotive interior-specific TPE material according to claim 1, characterized in that, The functional additives are antioxidants, light stabilizers and lubricants compounded in a mass ratio of 1:(0.8-1.2):(0.5-0.8).

5. The low-VOC automotive interior-specific TPE material according to claim 4, characterized in that, The antioxidant is at least one of antioxidant 1010 and antioxidant 168.

6. The low-VOC automotive interior-specific TPE material according to claim 4, characterized in that, The light stabilizer is hindered amine light stabilizer HS-944; the lubricant is zinc stearate.

7. The low-VOC automotive interior-specific TPE material according to claim 1, characterized in that, The phenolic resin is 2123 phenolic resin; the vulcanization accelerator is 2-mercaptobenzothiazole zinc salt.

8. The low-VOC automotive interior-specific TPE material according to claim 1, characterized in that, The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the nano molecular sieve is nano ZSM-5 molecular sieve.

9. A method for preparing a low-VOC automotive interior-specific TPE material according to any one of claims 1-8, characterized in that, Includes the following steps: Step S1, Pre-drying: Place SEBS in a vacuum oven at 78-82℃ and dry for 4-6 hours; Step S2, high-speed mixing: Add each component to a high-speed mixer according to the weight parts, and mix at 800-1200 rpm for 8-12 minutes to obtain a mixture. Step S3, Extrusion: The mixture is extruded using a co-rotating twin-screw extruder, and after washing and drying, a low-VOC TPE material for automotive interiors is obtained.

10. The method for preparing the low-VOC automotive interior-specific TPE material according to claim 9, characterized in that, In step S3, the twin-screw extruder is configured with ten temperature zones along the material feed direction, with the following temperatures: Zone 1 158-162℃, Zone 2 178-182℃, Zone 3 188-192℃, Zone 4 198-202℃, Zone 5 198-202℃, Zone 6 193-197℃, Zone 7 188-192℃, Zone 8 183-187℃, Zone 9 178-182℃, and Zone 10 173-178℃. The screw speed is 340-380 rpm. Supercritical CO2 is injected into Zone 8 of the screw for primary devolatilization. Zone 9 is equipped with a dual-stage vacuum port with a vacuum degree ≤-0.095 MPa and a residence time of 45 s. The flow rate of the supercritical CO2 is 3wt%-5wt% of the material mass flow rate.