A low odor thermoplastic elastomer and its preparation method and application

Abstract

The application relates to a preparation method of a low-odor thermoplastic elastomer, which comprises the following steps: S1. stirring and mixing ethylene-propylene-diene rubber and polyolefin resin, then adding fillers, lubricants and antioxidants to continue stirring and mixing to obtain premix A; S2. continuously and quantitatively adding the premix A and plasticizers into an extruder respectively, melting, extruding and granulating to obtain an intermediate; S3. stirring and mixing a crosslinking agent and a deodorizing agent, then adding the intermediate and a crosslinking aid to continue stirring and mixing to obtain premix B; and S4. continuously and quantitatively adding the premix B and plasticizers into an extruder respectively, melting, extruding, granulating and drying to remove odor, so as to obtain the low-odor thermoplastic elastomer. The application takes ethylene-propylene-diene rubber (EPDM) as a main material, obtains a low-odor dynamic vulcanized rubber / resin mixture, and innovatively pre-disperses the crosslinking agent in the deodorizing agent, so that the dispersibility of the crosslinking agent is effectively improved, and the odor property and the amount of the crosslinking agent are reduced.

Description

Technical Field

[0001] This invention relates to the field of thermoplastic elastomer materials technology, and in particular to a low-odor thermoplastic elastomer, its preparation method, and its application. Background Technology

[0002] As a thermoplastic elastomer with a unique "island structure," TPV combines the elasticity of rubber with the plasticity of plastic. While being more environmentally friendly than rubber, it is similar to rubber in terms of functionality, feel, and aesthetics. With the continuous development of the automotive industry, new energy vehicles are increasingly becoming commonplace. Requirements such as softer interior materials and lighter vehicle bodies are driving the search for thermoplastic elastomers to replace rubber products other than pneumatic tires. Simultaneously, due to reduced engine intervention, passengers are becoming increasingly sensitive to odors and airtightness within the vehicle.

[0003] Currently, thermoplastic elastomers are widely used in automotive interior and exterior trim and sealing products. However, most injection-molded thermoplastic elastomers suffer from high emissions and strong odors. As a vulcanization product, TPV (thermoplastic polyvinyl chloride) negatively impacts odor and VOCs due to the high-odor vulcanizing machine and the generation of odorous small molecules during the vulcanization process. This limits the application of TPV materials in automotive interior trim and sealing components where increasingly lower odor requirements are needed. Summary of the Invention

[0004] Based on this, in view of the defects of high emission and strong odor of current TPV materials, the purpose of this invention is to provide a low-odor thermoplastic elastomer, its preparation method and application. This thermoplastic elastomer has heat resistance, weather resistance and high mechanical strength, as well as excellent low odor and low VOC properties.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a method for preparing a low-odor thermoplastic elastomer, which includes the following steps:

[0007] S1. After mixing EPDM rubber and polyolefin resin, add filler, lubricant and antioxidant and continue mixing to obtain premix A;

[0008] S2. The premix A and the plasticizer are continuously and quantitatively added to an extruder, and after melting, extrusion and granulation, an intermediate is obtained;

[0009] S3. After mixing the crosslinking agent and the deodorizing agent, add the intermediate and the crosslinking aid and continue mixing to obtain premix B;

[0010] S4. The premix B and plasticizer are continuously and quantitatively added to the extruder, and after melting, extrusion, granulation, drying and deodorization, a low-odor thermoplastic elastomer is obtained.

[0011] As a further improvement of the above-mentioned solution of the present invention, the low-odor thermoplastic elastomer contains the following components in parts by weight: 100 parts of EPDM rubber, 80-200 parts of polyolefin resin, 70-130 parts of plasticizer, 100-150 parts of filler, 0.1-1 parts of crosslinking agent, 1-10 parts of co-crosslinking agent, 1-20 parts of lubricant, 1-20 parts of antioxidant, and 10-50 parts of deodorizer.

[0012] As a further improvement to the above-mentioned scheme of the present invention, the third monomer in the EPDM rubber is one of ethylene norbornene, dicyclopentadiene, and 1,4-hexadiene, wherein the mass content of the third monomer is 3%-12%; and the Mooney viscosity value of the EPDM rubber is 25-110.

[0013] As a further improvement to the above-mentioned scheme of the present invention, the crosslinking agent is at least one selected from isopropyl carbonate tert-butyl peroxide, phenolic resin, modified methyltriacetoxysilane, octamethylcyclotetrasiloxane, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane.

[0014] As a further improvement to the above-mentioned solution of the present invention, the deodorizing agent is at least one of the following: deodorizing masterbatch, fragrance, sepiolite, MOFs, ZIFs, POCs, porous carbon, UIOs, and silica.

[0015] As a further improvement to the above-described scheme of the present invention, the polyolefin resin is at least one of polypropylene, polyethylene, and ethylene octene copolymer.

[0016] As a further improvement to the above-described solution of the present invention, the plasticizer has a flash point greater than 200°C and a kinematic viscosity greater than 100 mmHg at 40°C. 2 / s of at least one of paraffin oil, cycloalkane oil, aromatic oil, and straight-chain alkane oil;

[0017] And / or, the filler is at least one of calcium carbonate, talc, kaolin, mica, wollastonite, barium sulfate, carbon black, and titanium dioxide, and its mesh size is not greater than 6000 mesh;

[0018] And / or, the co-crosslinking agent is at least one of bismaleimide, trialenylmethyltriisocyanurate, trialenyl isocyanurate, N,N'-m-phenylenebismaleimide, diphenylsilanediol, and trialenyl cyanurate.

[0019] And / or, the lubricant is a silicone masterbatch;

[0020] And / or, the antioxidant is at least one of 1010, 1076, 1790, and 168.

[0021] As a further improvement to the above-mentioned solution of the present invention, in step S1, EPDM rubber and polyolefin resin are mixed by stirring at a stirring speed of 100-500 r / min for 5-10 minutes; after adding filler, lubricant and antioxidant, the mixture is stirred at a stirring speed of 100-500 r / min for 10-210 minutes.

[0022] And / or, in step S2, the premix A and the plasticizer are continuously and quantitatively added to the first and middle sections of the solid conveying zone of the extruder, respectively, and a vacuum pump is used to perform vacuum treatment at the tail section of the extruder; the extruder is a co-rotating twin-screw extruder with a feed speed of 60-300 r / min, a screw speed of 200-500 r / min, a screw length-to-diameter ratio of 52-64, a temperature of no more than 120°C in the first section of the solid conveying zone, and a temperature of 150-220°C in the remaining sections;

[0023] And / or, in step S3, the crosslinking agent and the deodorizing agent are mixed by stirring at a speed of 300-500 r / min for 5-10 minutes; after adding the intermediate and the crosslinking aid, the mixture is stirred at a speed of 100-500 r / min for 10-20 minutes.

[0024] And / or, in step S4, the premix B and the plasticizer are continuously and quantitatively added to the first section of the solid conveying zone of the extruder, and a vacuum pump is used to perform vacuum treatment at the tail section of the extruder; the extruder is a co-rotating twin-screw extruder with a feed speed of 60-300 r / min, a screw speed of 200-500 r / min, a screw length-to-diameter ratio of 52-64, a temperature of no more than 120°C in the first section of the solid conveying zone, and a temperature of 150-220°C in the remaining sections.

[0025] The present invention also proposes a low-odor thermoplastic elastomer, which is prepared by the method for preparing low-odor thermoplastic elastomers as described above.

[0026] The present invention also proposes the application of a low-odor thermoplastic elastomer as described above in automotive interiors and seals.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. This invention uses ethylene propylene diene monomer (EPDM) rubber as the main material to obtain a low-odor dynamically vulcanized rubber / resin mixture. It innovatively pre-disperses the crosslinking agent in an odor-removing agent, effectively improving the dispersibility of the crosslinking agent and reducing its odor and dosage. This reduces the generation of small molecules and allows existing small molecules to be further degraded into odorless gases, which are then expelled in the molten state through a vacuum tube. Simultaneously, the pre-dispersion of the crosslinking agent improves process stability, reduces the amount of crosslinking agent used, and allows for the batch addition of plasticizers, integrated synchronously into the production process. This effectively improves the solvent and heat resistance of the material, while also increasing production capacity and reducing energy consumption. Furthermore, in the optimized process, the final product can be produced through a two-step extrusion method. The product obtained through this two-step method has low odor, low VOC content, and maintains temperature resistance, aging resistance, weather resistance, and high mechanical strength.

[0029] 2. This invention uses ethylene propylene diene monomer (EPDM) rubber as the main material. The rational selection of materials helps reduce the generation and retention of odors, combining the effects of reducing small molecule sources, adsorbing existing small molecules, and catalyzing the degradation of small molecules to minimize the odor of TPV materials. The reasonable formulation and excellent processing technology of this invention result in high production stability and continuous production of this material. A two-step process can yield materials with good temperature resistance, aging resistance, low odor, and low VOC performance.

[0030] 3. In this invention, the plasticizer is added in two stages, which effectively ensures the plasticizing effect of each component, avoids uneven plasticizing, and reduces the difficulty of processing to a certain extent, improves production stability, and has a wider range of compatibility with screws and processes. Furthermore, adding the crosslinking agent after stepwise mixing effectively controls the dispersion and dosage of the crosslinking agent, facilitating control of the degree of crosslinking and preventing over- or under-vulcanization.

[0031] 4. This invention utilizes EPDM, polyolefin resin, plasticizer, filler, crosslinking agent, co-crosslinking agent, lubricant, antioxidant, and deodorizer, processed according to a certain proportion and technical conditions to prepare a thermoplastic elastomer material. This material can be customized to different levels of hardness and tactile feel according to customer needs. It combines excellent sealing, noise reduction, mechanical properties, and human contact safety. It features low odor and low VOCs, low emissions, and strong processing performance, resistance to high and low temperatures, and resistance to environmental changes. It can be widely used in automotive interiors and other applications where high requirements exist for odor and emission control, such as anti-slip mats, storage box mats, door panels, and other soft-touch materials for automotive interiors.

[0032] 5. This invention optimizes the production process through reasonable production process design, and only requires two extrusion steps to produce low-odor thermoplastic elastomers. The production process is simple, stable and easy to control, environmentally friendly and has low equipment requirements, which is beneficial for large-scale industrial production. Detailed Implementation

[0033] To facilitate understanding of the present invention, a more comprehensive description will be provided below with reference to specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0035] It should be noted that the percentages (%) in the following embodiments are all mass percentages.

[0036] Example 1

[0037] This embodiment proposes a low-odor thermoplastic elastomer, which comprises the following raw materials in parts by weight: 100 parts EPDM rubber, 120 parts polyolefin resin, 130 parts plasticizer, 150 parts filler, 0.1 parts crosslinking agent, 1 part co-crosslinking agent, 5 parts lubricant, 2 parts antioxidant, and 30 parts deodorizer; wherein:

[0038] The polyolefin resin is random copolymer polypropylene produced using the Spheripol process. The plasticizer is a cycloalkane oil with a flash point greater than 270℃ and a kinematic viscosity greater than 300 mm² / s at 40℃. The filler is 1250-mesh calcium carbonate. The crosslinking agent is tert-butyl peroxide carbonate. The co-crosslinking agent is a blend of 50% bismaleimide and 50% N,N'-m-phenylenebismaleimide. The antioxidant is a blend of 50% 1010 and 50% 168. The deodorizer is a blend of 70% sepiolite and 30% MOFs.

[0039] The method for preparing the low-odor thermoplastic elastomer in this embodiment includes the following steps:

[0040] S1. Add EPDM rubber and polyolefin resin to a high-speed mixer and stir at 100 r / min for 5 minutes; then add filler, lubricant and antioxidant, and continue stirring at 100 r / min for 10 minutes to obtain premix A;

[0041] S2. Using a metering pump, premix A is continuously and quantitatively added to the first section of the solid conveying zone of the extruder. Using a metering pump, 40 wt% of plasticizer is continuously and quantitatively added to the middle section of the extruder. Vacuuming is performed at the tail section of the extruder using a vacuum pump. After melting, extrusion, and granulation in the extruder, the intermediate is obtained.

[0042] S3. Add the crosslinking agent and deodorizing agent to a high-speed mixer and stir at 400 r / min for 10 min; then add the intermediate and the crosslinking aid to the high-speed mixer and continue stirring at 200 r / min for 15 min to obtain premix B;

[0043] S4. Premix B and the remaining plasticizer are continuously added to the first section of the solid conveying zone of the extruder using a metering pump. Vacuum treatment is performed at the tail end of the extruder using a vacuum pump. After melting, extrusion, and granulation in the extruder, the mixture is then placed in a circulating drying tank at 80°C for 4 hours to remove odor, thus obtaining a low-odor thermoplastic elastomer.

[0044] The extruders in steps S2 and S4 above are co-rotating twin-screw extruders with a feed speed of 150 r / min, a screw speed of 350 r / min, and a screw length-to-diameter ratio of 64. The temperature of the first section of the solid conveying zone of the extruder is 80℃, the temperature of the front section of the extruder is 180℃, and the temperature of the remaining sections is 200-220℃.

[0045] Example 2

[0046] This embodiment proposes a low-odor thermoplastic elastomer, which comprises the following raw materials in parts by weight: 100 parts EPDM rubber, 120 parts polyolefin resin, 130 parts plasticizer, 150 parts filler, 0.15 parts crosslinking agent, 1.5 parts co-crosslinking agent, 4 parts lubricant, 2 parts antioxidant, and 40 parts deodorizer; wherein:

[0047] The polyolefin resin is formed by mixing 80% of Spheripol process random copolymer polypropylene and 20% of Sumitimo process homopolymer polypropylene; the plasticizer is a naphthenic oil with a flash point greater than 270℃ and a kinematic viscosity greater than 300 mm2 / s at 40℃; the filler is a mixture of 90% 2500 mesh talc powder and 10% rutile titanium dioxide; the crosslinking agent is phenolic resin; the co-crosslinking agent is a mixture of 50% bismaleimide and 50% triallyl cyanurate; the antioxidant is a blend of 50% 1076 and 50% 168; and the deodorizing agent is a blend of 30% deodorizing masterbatch, 30% porous carbon, and 40% UIO-66.

[0048] The method for preparing the low-odor thermoplastic elastomer in this embodiment includes the following steps:

[0049] S1. Add EPDM rubber and polyolefin resin to a high-speed mixer and stir at 200 r / min for 5 minutes; then add filler, lubricant and antioxidant, and continue stirring at 300 r / min for 10 minutes to obtain premix A;

[0050] S2. Using a metering pump, premix A is continuously and quantitatively added to the first section of the solid conveying zone of the extruder. Using a metering pump, 30 wt% of plasticizer is continuously and quantitatively added to the middle section of the extruder. Vacuuming is performed at the tail section of the extruder using a vacuum pump. After melting, extrusion, and granulation in the extruder, the intermediate is obtained.

[0051] S3. Add the crosslinking agent and deodorizing agent to a high-speed mixer and stir at 500 r / min for 10 min; then add the intermediate and the crosslinking aid to the high-speed mixer and continue stirring at 200 r / min for 10 min to obtain premix B;

[0052] S4. Premix B and the remaining plasticizer are continuously added to the first section of the solid conveying zone of the extruder using a metering pump. Vacuum treatment is performed at the tail end of the extruder using a vacuum pump. After melting, extrusion, and granulation in the extruder, the mixture is then placed in a circulating drying tank at 80°C for 4 hours to remove odor, thus obtaining a low-odor thermoplastic elastomer.

[0053] The extruders in steps S2 and S4 above are co-rotating twin-screw extruders with a feed speed of 150 r / min, a screw speed of 350 r / min, and a screw length-to-diameter ratio of 64. The temperature of the first section of the solid conveying zone of the extruder is 90℃, the temperature of the front section of the extruder is 160℃, and the temperature of the remaining sections is 170-200℃.

[0054] Example 3

[0055] This embodiment proposes a low-odor thermoplastic elastomer, which comprises the following raw materials in parts by weight: 100 parts EPDM rubber, 200 parts polyolefin resin, 100 parts plasticizer, 130 parts filler, 0.1 parts crosslinking agent, 1.5 parts co-crosslinking agent, 8 parts lubricant, 2 parts antioxidant, and 40 parts deodorizer; wherein:

[0056] The polyolefin resin is formed by mixing 50% of Spheripol process random copolymer polypropylene and 50% of Spherizone process random copolymer polypropylene; the plasticizer is paraffin oil with a flash point greater than 270℃ and a kinematic viscosity greater than 300 mm2 / s at 40℃; the filler is formed by mixing 90% of 3500 mesh wollastonite and 10% of rutile titanium dioxide; the crosslinking agent is 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; the co-crosslinking agent is formed by mixing 50% of N,N'-m-phenylenebismaleimide and 50% triallyl cyanurate; the antioxidant is formed by compounding 50% of 1076 and 50% of 1790; and the deodorizer is formed by compounding 50% of sepiolite and 50% of POCs.

[0057] The method for preparing the low-odor thermoplastic elastomer in this embodiment includes the following steps:

[0058] S1. Add EPDM rubber and polyolefin resin to a high-speed mixer and stir at 200 r / min for 5 minutes; then add filler, lubricant and antioxidant, and continue stirring at 200 r / min for 10 minutes to obtain premix A;

[0059] S2. Using a metering pump, premix A is continuously and quantitatively added to the first section of the solid conveying zone of the extruder. Using a metering pump, 20 wt% of plasticizer is continuously and quantitatively added to the middle section of the extruder. Vacuuming is performed at the tail section of the extruder using a vacuum pump. After melting, extrusion, and granulation in the extruder, the intermediate is obtained.

[0060] S3. Add the crosslinking agent and deodorizing agent to a high-speed mixer and stir at 500 r / min for 5 min; then add the intermediate and the crosslinking aid to the high-speed mixer and continue stirring at 100 r / min for 10 min to obtain premix B;

[0061] S4. Premix B and the remaining plasticizer are continuously added to the first section of the solid conveying zone of the extruder using a metering pump. Vacuum treatment is performed at the tail end of the extruder using a vacuum pump. After melting, extrusion, and granulation in the extruder, the mixture is then placed in a circulating drying tank at 80°C for 4 hours to remove odor, thus obtaining a low-odor thermoplastic elastomer.

[0062] The extruders in steps S2 and S4 above are co-rotating twin-screw extruders with a feed speed of 200 r / min, a screw speed of 400 r / min, and a screw length-to-diameter ratio of 60. The temperature of the first section of the solid conveying zone of the extruder is 80℃, the temperature of the front section of the extruder is 170℃, and the temperature of the remaining sections is 170-220℃.

[0063] Comparative Example 1

[0064] This comparative example presents a thermoplastic elastomer. The raw materials and amounts used in this comparative example are the same as in Example 1. The only difference between this comparative example and Example 1 is the preparation step. The preparation method of the thermoplastic elastomer in this comparative example includes the following steps:

[0065] S1. Add EPDM rubber and polyolefin resin to a high-speed mixer and stir at 100 r / min for 5 minutes. Then add filler, lubricant, antioxidant and deodorizer and continue stirring at 100 r / min for 10 minutes to obtain premix A.

[0066] S2. Using a metering pump, premix A is continuously and quantitatively added to the first section of the solid conveying zone of the extruder. Using a metering pump, 40 wt% of plasticizer is continuously and quantitatively added to the middle section of the extruder. Vacuuming is performed at the tail section of the extruder using a vacuum pump. After melting, extrusion, and granulation in the extruder, the intermediate is obtained.

[0067] S3. Add the intermediate, crosslinking agent and co-crosslinking agent into a high-speed mixer and continue stirring at 200 r / min for 15 minutes to obtain premix B;

[0068] S4. Premix B and the remaining plasticizer are continuously added to the first section of the solid conveying zone of the extruder using a metering pump. Vacuum treatment is performed at the tail end of the extruder using a vacuum pump. After melting, extrusion, and granulation in the extruder, the mixture is then placed in a circulating drying tank at 80°C for 4 hours to remove odor, thus obtaining the thermoplastic elastomer.

[0069] The extruders in steps S2 and S4 above are co-rotating twin-screw extruders with a feed speed of 150 r / min, a screw speed of 350 r / min, and a screw length-to-diameter ratio of 64. The temperature of the first section of the solid conveying zone of the extruder is 80℃, the temperature of the front section of the extruder is 180℃, and the temperature of the remaining sections is 200-220℃.

[0070] Comparative Example 2

[0071] This comparative example presents a thermoplastic elastomer. The preparation method of the thermoplastic elastomer in this comparative example is the same as that in Example 1, except that the raw materials and amounts are different. The thermoplastic elastomer in this comparative example includes the following raw materials in parts by weight: 100 parts of EPDM rubber, 110 parts of polyolefin resin, 120 parts of plasticizer, 140 parts of filler, 0.2 parts of crosslinking agent, 2 parts of co-crosslinking agent, 5 parts of lubricant, 2 parts of antioxidant, and 50 parts of deodorizer; wherein: the polyolefin resin is Unipol process copolymerized polypropylene, and the plasticizer is a high flash point... The aromatic hydrocarbon oil has a kinematic viscosity greater than 100 mm² / s at 200℃ and 40℃. The filler is 1250 mesh calcium carbonate. The crosslinking agent is a mixture of 50% isopropyl tert-butyl peroxide carbonate and 50% 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane. The co-crosslinking agent is a compound of 50% bismaleimide and 50% diphenylsilanediol. The antioxidant is a compound of 50% 1010 and 50% 168. The deodorizing agent is a compound of 30% deodorizing masterbatch, 30% fragrance and 40% porous carbon.

[0072] Test case

[0073] The thermoplastic elastomers prepared in Examples 1-3 and Comparative Examples 1-2 were subjected to performance tests. The test results are shown in Table 1. The test methods are as follows:

[0074] Hardness, measured according to ISO 7619-1, Type A;

[0075] Tensile strength was tested according to ISO 37-1, using type I dumbbell-shaped specimens, at a tensile test rate of 500 mm / min.

[0076] Tear strength was tested according to ISO 34-1, Method B, using a right-angled specimen without cuts, at a test rate of 500 mm / min.

[0077] Odor properties were tested according to Q / MA P3107 and Q / MA T5507 at 23℃, 40℃ and 80℃ respectively.

[0078] VOC testing standard is GB / T27630, which tests the concentration of benzene, toluene, xylene, ethylbenzene, styrene, formaldehyde, acetaldehyde and acrolein in the material;

[0079] The atomization value is tested according to ISO 6452, and the test method is gravimetric method.

[0080] Weather resistance was tested according to SAE J2527;

[0081] Table 1. Performance test results of the thermoplastic elastomers prepared in Examples 1-3 and Comparative Examples 1-2

[0082]

[0083] As can be seen from the results in Table 1, the materials prepared in Examples 1-3 of the present invention have superior high, low, and room temperature odor properties. At the same time, the VOC and atomization of Examples 1-3 are generally better than those of Comparative Examples 1-2. Compared with Comparative Examples 1-2, Examples 1-3 have higher mechanical strength and better weather resistance.

[0084] In Example 1, the deodorizing agent was 30 parts, and the crosslinking agent and co-crosslinking agent were 0.1 parts and 1 part, respectively. Compared with Example 1, Example 2 has a larger amount of deodorizing agent and a larger amount of crosslinking agent and co-crosslinking agent. Compared with Example 1, Example 2 has better atomization performance and weather resistance, but the odor is not as good as Example 1. At the same time, its degree of crosslinking is not significantly improved compared with Example 1, and even the strength is lower than that of Example 1.

[0085] Compared with Example 2, Example 3 has the same amount of deodorizing agent, but the combination of deodorizing agents is different. The reduction in the amount of plasticizer, crosslinking agent and co-crosslinking agent makes Example 3 have lower odor, atomization and VOC performance.

[0086] Compared with Example 1, Comparative Example 1 used the same material formulation, but the processing was carried out according to the conventional method. The comparison shows that by improving the process, the crosslinking agent with obvious odor is pre-dispersed in the deodorizing agent with porous structure and embrittlement degradation effect. This helps to reduce the amount of crosslinking agent and co-crosslinking agent used, which not only reduces the cost but also helps to improve the stability of the process.

[0087] Compared to Example 1, the processing technology in Comparative Example 2 was the same as in Example 1, but the raw materials and amounts used were different. Comparative Example 2 had higher crosslinking strength, but poorer odor. The lower flash point plasticizer caused the atomization performance to seriously exceed the limit. At the same time, more deodorizing agent did not bring better odor, and the introduction of fragrance may even lead to more obvious odor. Therefore, a reasonable and efficient formulation design and process route have a significant impact on process stability and final product performance.

[0088] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a low-odor thermoplastic elastomer, characterized in that, It includes the following steps: S1. After mixing EPDM rubber and polyolefin resin, add filler, lubricant and antioxidant and continue mixing to obtain premix A; S2. The premix A and the plasticizer are continuously and quantitatively added to an extruder, and after melting, extrusion and granulation, an intermediate is obtained; S3. After mixing the crosslinking agent and the deodorizing agent, add the intermediate and the crosslinking aid and continue mixing to obtain premix B; S4. The premix B and plasticizer are continuously and quantitatively added to the extruder, and after melting, extrusion, granulation, drying and deodorization, a low-odor thermoplastic elastomer is obtained. The low-odor thermoplastic elastomer contains the following components in parts by weight: 100 parts EPDM rubber, 80-200 parts polyolefin resin, 70-130 parts plasticizer, 100-150 parts filler, 0.1-1 part crosslinking agent, 1-10 parts co-crosslinking agent, 1-20 parts lubricant, 1-20 parts antioxidant, and 10-50 parts deodorizer; the deodorizer is at least one of deodorizing masterbatch, sepiolite, MOFs, ZIFs, POCs, porous carbon, UIOs, and silica.

2. The method for preparing the low-odor thermoplastic elastomer according to claim 1, characterized in that, The third monomer in the EPDM rubber is one of ethylene norbornene, dicyclopentadiene, and 1,4-hexadiene, wherein the mass content of the third monomer is 3%-12%; the Mooney viscosity of the EPDM rubber is 25-110.

3. The method for preparing the low-odor thermoplastic elastomer according to claim 1, characterized in that, The crosslinking agent is at least one of the following: isopropyl carbonate tert-butyl peroxide, phenolic resin, modified methyltriacetoxysilane, octamethylcyclotetrasiloxane, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane.

4. The method for preparing the low-odor thermoplastic elastomer according to claim 1, characterized in that, The polyolefin resin is at least one of polypropylene, polyethylene, and ethylene octene copolymer.

5. The method for preparing a low-odor thermoplastic elastomer according to claim 1, characterized in that, The plasticizer has a flash point greater than 200℃ and a kinematic viscosity greater than 100 mmHg at 40℃. 2 / s of at least one of paraffin oil, cycloalkane oil, aromatic oil, and straight-chain alkane oil; And / or, the filler is at least one of calcium carbonate, talc, kaolin, mica, wollastonite, barium sulfate, carbon black, and titanium dioxide, and its mesh size is not greater than 6000 mesh; And / or, the co-crosslinking agent is at least one of bismaleimide, trialenylmethyltriisocyanurate, trialenyl isocyanurate, N,N'-m-phenylenebismaleimide, diphenylsilanediol, and trialenyl cyanurate. And / or, the lubricant is a silicone masterbatch; And / or, the antioxidant is at least one of 1010, 1076, 1790, and 168.

6. The method for preparing a low-odor thermoplastic elastomer according to claim 1, characterized in that, In step S1, EPDM rubber and polyolefin resin are mixed by stirring at a speed of 100-500 r / min for 5-10 minutes; after adding filler, lubricant and antioxidant, the mixture is stirred at a speed of 100-500 r / min for 10-210 minutes. And / or, in step S2, the premix A and the plasticizer are continuously and quantitatively added to the first and middle sections of the solid conveying zone of the extruder, respectively, and a vacuum pump is used to perform vacuum treatment at the tail section of the extruder; the extruder is a co-rotating twin-screw extruder with a feed speed of 60-300 r / min, a screw speed of 200-500 r / min, a screw length-to-diameter ratio of 52-64, a temperature of no more than 120°C in the first section of the solid conveying zone, and a temperature of 150-220°C in the remaining sections; And / or, in step S3, the crosslinking agent and the deodorizing agent are mixed by stirring at a speed of 300-500 r / min for 5-10 minutes; after adding the intermediate and the crosslinking aid, the mixture is stirred at a speed of 100-500 r / min for 10-20 minutes. And / or, in step S4, the premix B and the plasticizer are continuously and quantitatively added to the first section of the solid conveying zone of the extruder, and a vacuum pump is used to perform vacuum treatment at the tail section of the extruder; the extruder is a co-rotating twin-screw extruder with a feed speed of 60-300 r / min, a screw speed of 200-500 r / min, a screw length-to-diameter ratio of 52-64, a temperature of no more than 120°C in the first section of the solid conveying zone, and a temperature of 150-220°C in the remaining sections.

7. A low-odor thermoplastic elastomer, characterized in that, It is prepared using the method for preparing low-odor thermoplastic elastomers as described in any one of claims 1-6.

8. The application of a low-odor thermoplastic elastomer as described in claim 7 in automotive interiors and seals.

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