Preparation method of foamed TPV (thermoplastic vulcanizate) material for automobile sealing strip containing regenerated polypropylene

Abstract

The invention discloses a preparation method of a foamed TPV (thermoplastic vulcanizate) material containing regenerated polypropylene for an automobile sealing strip. The foamed TPV material comprises ethylene propylene diene monomer, regenerated polypropylene, a filler, filling oil, a vulcanizing agent, an auxiliary vulcanizing agent, a foaming agent and an antioxidant. The ethylene propylene diene monomer is prepared from the following raw materials in parts by mass: 100 parts of ethylene propylene diene monomer, 40-60 parts of regenerated polypropylene, 40-60 parts of filler, 60-80 parts of filling oil, 1-3 parts of vulcanizing agent, 0.5-1 part of auxiliary vulcanizing agent, 2-4 parts of foaming agent and 0.5-1 part of antioxidant. The foamed TPV material for the automobile sealing strip, prepared from the regenerated polyethylene, has a uniform closed-cell material structure, is good in mechanical property and is green and environment-friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of production and processing of thermoplastic elastomers, and specifically relates to a method for preparing a foamed TPV material for automobile sealing strips containing recycled polypropylene. Background Art

[0002] Automobile sealing strips are a type of strip-shaped sealing product made of rubber or plastic. They are widely used in car doors, windows, trunks, engine compartments and other parts to fill the gaps between various parts. They have functions such as shock absorption, isolation, and decoration.

[0003] At present, automotive sealing strips generally use ethylene propylene diene monomer (EPDM) or polyvinyl chloride (PVC) as raw materials. EPDM has excellent mechanical properties and is mainly used in various dynamic sealing parts. EPDM sealing strips may undergo a vulcanization process during the production process, which produces odor and cannot be recycled or degraded, causing certain pressure on the environment. PVC sealing strips have the advantages of a smooth and beautiful appearance and easy coloring, but due to their poor dynamic elasticity. With the development of new environmentally friendly materials, thermoplastic elastomers (TPE), especially EPDM / PP-TPV made by full dynamic vulcanization of EPDM and polypropylene (PP), are becoming more and more widely used in the automotive sealing strip industry due to their excellent mechanical properties, good processing performance and repeatable recycling.

[0004] Waste plastics are increasingly polluting the environment. How to recycle waste plastics and solve the problem of making full use of recycled plastics has attracted widespread attention from researchers. The main treatment methods for waste plastics are landfill, incineration and recycling. Among them, recycling is the most beneficial way to protect the environment and recycle resources. Using recycled polypropylene to prepare EPDM / PP-TPV is an effective way to solve the pollution of waste polypropylene and realize the rational use of resources.

[0005] Foam rubber refers to various types of rubber with a pore structure. According to the shape of the pores, it is generally divided into closed-cell foam rubber and open-cell foam rubber. Since the foam rubber with a closed-cell structure has both the characteristics of a solid and the typical characteristics of a gas, it has the advantages of low density, high elasticity, sound insulation, heat insulation, shock absorption and good mechanical properties. In traditional physical and chemical foaming technology, the foaming effect is affected by many factors such as the type, dosage and process conditions of the foaming agent. After foaming, there may be problems such as uneven pores and pore rupture, which affect the overall performance of the material. The existing expandable microsphere foaming agent is a new type of special foaming agent. It is a milky white tiny spherical plastic particle with a diameter of 10 to 45 μm. After the microsphere is heated, the polymer shell softens and the gas in the shell expands, expanding to 20 to 50 times the original volume in a very short time. The shell of the microsphere after foaming will not break, and it still maintains a complete sealed sphere, thereby avoiding the shortcomings of uneven pores, pore rupture, poor pore resilience, etc., and ensuring good mechanical properties. In addition, polymer microspheres are non-toxic and pollution-free and can be used as environmentally friendly foaming agents.

[0006] At present, there is no report on the use of waste plastics in the preparation of automotive sealing strips. Summary of the invention

[0007] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0008] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0009] Therefore, the object of the present invention is to overcome the deficiencies in the prior art and provide a foamed TPV material for automobile sealing strips containing recycled polypropylene.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions: A foamed TPV material for automobile sealing strips containing recycled polypropylene, comprising:

[0011] EPDM rubber, recycled polypropylene, filler, filler oil, vulcanizer, co-vulcanizer, foaming agent and antioxidant;

[0012] Calculated by weight of each raw material, the EPDM rubber is 100 parts, the recycled polypropylene is 40-60 parts, the filler is 40-60 parts, the filler oil is 60-80 parts, the vulcanizer is 1-3 parts, the co-vulcanizer is 0.5-1 part, the foaming agent is 2-4 parts, and the antioxidant is 0.5-1 part.

[0013] As a preferred embodiment of the TPV material of the present invention, the filler is a composition of ultrafine calcium carbonate and carbon black, and the mass ratio thereof is 1:1.

[0014] As a preferred solution of the TPV material of the present invention, the filler oil is one of paraffin oil and cyclohexane oil.

[0015] As a preferred embodiment of the TPV material of the present invention, the vulcanizing agent is one of dicumyl peroxide and di-tert-butylcumyl peroxide or a combination thereof.

[0016] As a preferred embodiment of the TPV material of the present invention, the co-vulcanizing agent is triallyl isocyanate.

[0017] As a preferred embodiment of the TPV material of the present invention, the foaming agent is Expancel920DU40 microsphere foaming agent.

[0018] As a preferred embodiment of the TPV material of the present invention, the antioxidant is a hindered phenol antioxidant, including 2-6-di-tert-butyl-4-methylphenol.

[0019] Another object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a TPV material, comprising:

[0020] Add recycled polypropylene, EPDM rubber, filler, filler oil and antioxidant, which account for 2 / 3 of the weight of recycled polypropylene, into a mixer and mix evenly, and then send into a twin-screw extruder for extrusion granulation to obtain semi-finished product particles a;

[0021] The remaining 1 / 3 weight of the recycled polypropylene is mixed evenly with the vulcanizing agent and the co-vulcanizing agent, and then sent to a twin-screw extruder for extrusion granulation to obtain semi-finished product particles b;

[0022] The particles a, particles b and microsphere foaming agent are mixed and then fed into a twin-screw extruder. After extrusion, the mixture is cooled and shaped to obtain a foamed TPV material for automobile sealing strips.

[0023] As a preferred embodiment of the preparation method of the present invention, the extrusion parameters of the twin-screw extruder for preparing the semi-finished particles a are:

[0024] The operating temperature of the twin-screw extruder is 170-210°C, and the screw speed is 300-350rpm;

[0025] The screw extruder extrusion parameters for preparing the semi-finished particles b are:

[0026] The operating temperature of the twin-screw extruder is 160-190°C, and the screw speed is 250-300rpm.

[0027] As a preferred embodiment of the preparation method of the present invention, the particles a, particles b and microsphere foaming agent are mixed and then fed into a twin-screw extruder, wherein the operating temperature of the twin-screw extruder is 170-180° C. and the screw speed is 250-300 rpm.

[0028] Beneficial effects of the present invention:

[0029] (1) The present invention uses recycled polypropylene as one of the main raw materials. The selected recycled polypropylene undergoes a strict cleaning and impurity removal process, thereby ensuring the quality stability of the recycled polypropylene, developing new uses for the recycled polypropylene, reducing production costs, and meeting environmental protection requirements;

[0030] (2) The application of the microsphere foaming agent of the present invention simplifies the foaming process, improves the foaming stability and uniformity, and at the same time, the formed closed-cell bubbles of uniform size and uniform dispersion make the density and cross-sectional size fluctuation of the foamed TPV product small during the extrusion process, and the product quality and dimensional stability are significantly improved, and its sound insulation performance and mechanical properties are also improved;

[0031] (3) The present invention uses microsphere foaming technology to successfully prepare TPV materials for automotive foam sealing strips, which reduces product weight, saves materials, and meets the demand for lightweight in the automotive field. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0034] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0035] In the embodiment of the present invention:

[0036] EPDM rubber comes from Shanghai Sinopec Mitsui Elastomer Co., Ltd., with an ethylene content between 45% and 60%, an ENB type third monomer, and an ENB content of more than 7.5%, and a Mooney viscosity of 50 to 70;

[0037] Recycled polypropylene comes from Changzhou Boyi Plastic Co., Ltd.;

[0038] Ultrafine calcium carbonate is a commercially available light calcium carbonate with a particle size of less than 0.2 μm;

[0039] Carbon black is N326, a product of Jinneng Technology Co., Ltd.;

[0040] The microsphere foaming agent is Expancel 920DU40 microsphere foaming agent from Nouryon Group;

[0041] AC foaming agent comes from Zhejiang Shuntai Rubber and Plastic Technology Co., Ltd.

[0042] Example 1

[0043] A foamed TPV material for automobile sealing strips containing recycled polypropylene, comprising the following components in parts by mass:

[0044] EPDM rubber: 100 parts;

[0045] Recycled polypropylene: 50 parts;

[0046] Filler: 1:1 composition of ultrafine calcium carbonate and carbon black, 50 parts;

[0047] Filler oil: paraffin oil, 70 parts;

[0048] Curing agent: dicumyl peroxide, 2 parts;

[0049] Co-vulcanizing agent: triallyl isocyanate, 1 part;

[0050] Foaming agent: Expancel 920DU40 microsphere foaming agent, 3 parts;

[0051] Antioxidant: 2-6 di-tert-butyl-4-methylphenol, 0.8 parts.

[0052] The preparation process is as follows:

[0053] Two-thirds of recycled polypropylene, EPDM rubber, filler, filling oil and antioxidant are added into a mixer and mixed evenly, and then sent into a twin-screw extruder for extrusion granulation to obtain semi-finished particles a. The operating temperature of the twin-screw extruder is 170-210°C, and the screw speed is 330rpm;

[0054] The remaining one third of the recycled polypropylene is mixed evenly with the vulcanizing agent and the co-vulcanizing agent, and then sent to a twin-screw extruder for extrusion granulation to obtain semi-finished product particles b. The operating temperature of the twin-screw extruder is 160-190°C, and the screw speed is 250rpm;

[0055] After the particles a, particles b and microsphere foaming agent are mixed, they are sent into a twin-screw extruder at a temperature of 170-180° C. and a screw speed of 300 rpm. After extrusion, they are cooled and shaped to obtain a foamed TPV material for automobile sealing strips.

[0056] Example 2

[0057] A foamed TPV material for automobile sealing strips containing recycled polypropylene, comprising the following components in parts by mass:

[0058] EPDM rubber: 100 parts;

[0059] Recycled polypropylene: 60 parts;

[0060] Filler: 1:1 composition of ultrafine calcium carbonate and carbon black, 60 parts;

[0061] Filler oil: paraffin oil, 80 parts;

[0062] Curing agent: di-tert-butyl peroxide isopropylbenzene, 3 parts;

[0063] Co-vulcanizing agent: triallyl isocyanate, 1 part;

[0064] Blowing agent: Expancel 920DU40 microsphere blowing agent, 4 parts;

[0065] Antioxidant: 2-6 di-tert-butyl-4-methylphenol, 1 part.

[0066] The preparation process is as follows:

[0067] Two-thirds of recycled polypropylene, EPDM rubber, filler, filler oil and antioxidant are added into a mixer and mixed evenly, and then sent into a twin-screw extruder for extrusion granulation to obtain semi-finished particles a. The operating temperature of the twin-screw extruder is 170-210°C, and the screw speed is 350rpm;

[0068] The remaining one third of the recycled polypropylene is mixed evenly with the vulcanizing agent and the co-vulcanizing agent, and then sent to a twin-screw extruder for extrusion granulation to obtain semi-finished product particles b. The operating temperature of the twin-screw extruder is 160-190°C, and the screw speed is 300rpm;

[0069] After the particles a, particles b and microsphere foaming agent are mixed, they are sent into a twin-screw extruder at a temperature of 170-180° C. and a screw speed of 300 rpm. After extrusion, they are cooled and shaped to obtain a foamed TPV material for automobile sealing strips.

[0070] Example 3

[0071] A foamed TPV material for automobile sealing strips containing recycled polypropylene, comprising the following components in parts by mass:

[0072] EPDM rubber: 100 parts;

[0073] Recycled polypropylene: 40 parts;

[0074] Filler: 1:1 composition of ultrafine calcium carbonate and carbon black, 50 parts;

[0075] Filler oil: naphthenic oil, 60 parts;

[0076] Curing agent: dicumyl peroxide, 1 part;

[0077] Co-vulcanizing agent: triallyl isocyanate, 0.5 parts;

[0078] Blowing agent: Expancel 920DU40 microsphere blowing agent, 2.5 parts;

[0079] Antioxidant: 2-6 di-tert-butyl-4-methylphenol, 0.5 parts.

[0080] The preparation process is as follows:

[0081] Two thirds of recycled polypropylene, EPDM rubber, filler, filling oil and antioxidant are added into a mixer and mixed evenly, and then sent into a twin-screw extruder for extrusion and granulation to obtain semi-finished particles a. The operating temperature of the twin-screw extruder is 170-210°C and the screw speed is 300rpm;

[0082] The remaining one third of the recycled polypropylene is mixed evenly with the vulcanizing agent and the co-vulcanizing agent, and then sent to a twin-screw extruder for extrusion granulation to obtain semi-finished product particles b. The operating temperature of the twin-screw extruder is 160-190°C, and the screw speed is 300rpm;

[0083] After the particles a, particles b and microsphere foaming agent are mixed, they are sent into a twin-screw extruder at a temperature of 170-180° C. and a screw speed of 300 rpm. After extrusion, they are cooled and shaped to obtain a foamed TPV material for automobile sealing strips.

[0084] Example 4

[0085] A foamed TPV material for automobile sealing strips containing recycled polypropylene, comprising the following components in parts by mass:

[0086] EPDM rubber: 100 parts;

[0087] Recycled polypropylene: 45 parts;

[0088] Filler: 1:1 composition of ultrafine calcium carbonate and carbon black, 50 parts;

[0089] Filler oil: naphthenic oil, 75 parts;

[0090] Curing agent: di-tert-butyl peroxide isopropylbenzene, 1.5 parts;

[0091] Co-vulcanizing agent: triallyl isocyanate, 0.5 parts;

[0092] Foaming agent: Expancel 920DU40 microsphere foaming agent, 2 parts;

[0093] Antioxidant: 2-6 di-tert-butyl-4-methylphenol, 0.6 parts.

[0094] The preparation process is as follows:

[0095] Two-thirds of recycled polypropylene, EPDM rubber, filler, filler oil and antioxidant are added into a mixer and mixed evenly, and then sent into a twin-screw extruder for extrusion granulation to obtain semi-finished particles a. The operating temperature of the twin-screw extruder is 170-210°C, and the screw speed is 350rpm;

[0096] The remaining one third of the recycled polypropylene is mixed evenly with the vulcanizing agent and the co-vulcanizing agent, and then sent to a twin-screw extruder for extrusion granulation to obtain semi-finished particles b. The operating temperature of the twin-screw extruder is 160-190°C, and the screw speed is 280rpm;

[0097] After the particles a, particles b and microsphere foaming agent are mixed, they are sent into a twin-screw extruder at a temperature of 170-180° C. and a screw speed of 250 rpm. After extrusion, they are cooled and shaped to obtain a foamed TPV material for automobile sealing strips.

[0098] Example 5

[0099] A foamed TPV material for automobile sealing strips containing recycled polypropylene, comprising the following components in parts by mass:

[0100] EPDM rubber: 100 parts;

[0101] Recycled polypropylene: 40 parts;

[0102] Filler: 1:1 composition of ultrafine calcium carbonate and carbon black, 60 parts;

[0103] Filler oil: paraffin oil, 80 parts;

[0104] Curing agent: dicumyl peroxide, 2 parts;

[0105] Co-vulcanizing agent: triallyl isocyanate, 0.5 parts;

[0106] Blowing agent: Expancel 920DU40 microsphere blowing agent, 4 parts;

[0107] Antioxidant: 2-6 di-tert-butyl-4-methylphenol, 1 part.

[0108] The preparation process is as follows:

[0109] Two thirds of recycled polypropylene, EPDM rubber, filler, filling oil and antioxidant are added into a mixer and mixed evenly, and then sent into a twin-screw extruder for extrusion and granulation to obtain semi-finished particles a. The operating temperature of the twin-screw extruder is 170-210°C and the screw speed is 300rpm;

[0110] The remaining one third of the recycled polypropylene is mixed evenly with the vulcanizing agent and the co-vulcanizing agent, and then sent to a twin-screw extruder for extrusion granulation to obtain semi-finished product particles b. The operating temperature of the twin-screw extruder is 160-190°C, and the screw speed is 300rpm;

[0111] After the particles a, particles b and microsphere foaming agent are mixed, they are sent into a twin-screw extruder at a temperature of 170-180° C. and a screw speed of 300 rpm. After extrusion, they are cooled and shaped to obtain a foamed TPV material for automobile sealing strips.

[0112] Example 6

[0113] A foamed TPV material for automobile sealing strips containing recycled polypropylene, comprising the following components in parts by mass:

[0114] EPDM rubber: 100 parts;

[0115] Recycled polypropylene: 50 parts;

[0116] Filler: 1:1 composition of ultrafine calcium carbonate and carbon black, 40 parts;

[0117] Filler oil: naphthenic oil, 60 parts;

[0118] Curing agent: dicumyl peroxide, 1 part;

[0119] Co-vulcanizing agent: triallyl isocyanate, 1 part;

[0120] Blowing agent: Expancel 920DU40 microsphere blowing agent, 4 parts;

[0121] Antioxidant: 2-6 di-tert-butyl-4-methylphenol, 1 part.

[0122] The preparation process is as follows:

[0123] Two-thirds of recycled polypropylene, EPDM rubber, filler, filling oil and antioxidant are added into a mixer and mixed evenly, and then sent into a twin-screw extruder for extrusion granulation to obtain semi-finished particles a. The operating temperature of the twin-screw extruder is 170-210°C, and the screw speed is 330rpm;

[0124] The remaining one third of the recycled polypropylene is mixed evenly with the vulcanizing agent and the co-vulcanizing agent, and then sent to a twin-screw extruder for extrusion granulation to obtain semi-finished product particles b. The operating temperature of the twin-screw extruder is 160-190°C, and the screw speed is 300rpm;

[0125] After the particles a, particles b and microsphere foaming agent are mixed, they are sent into a twin-screw extruder at a temperature of 170-180° C. and a screw speed of 300 rpm. After extrusion, they are cooled and shaped to obtain a foamed TPV material for automobile sealing strips.

[0126] Comparative Example 1

[0127] The specific gravity of each component in Comparative Example 1 is the same as that in Example 1, except that the foaming agent used is AC (azodicarbonamide).

[0128] The preparation process of Comparative Example 1 is the same as that of Example 1.

[0129] Comparative Example 2

[0130] The specific gravity of each component in Comparative Example 2 is the same as that in Example 1, except that the filler used is ultrafine calcium carbonate.

[0131] The preparation process of Comparative Example 2 is the same as that of Example 1.

[0132] Comparative Example 3

[0133] The specific gravity of each component in Comparative Example 3 is the same as that in Example 1, except that the filler used is carbon black.

[0134] The preparation process of Comparative Example 3 is the same as that of Example 1.

[0135] Comparative Example 4

[0136] The specific gravity of each component in Comparative Example 4 is the same as that in Example 1, except that the filler used is a 1:1 composition of ordinary calcium carbonate with a particle size greater than 1 μm and carbon black.

[0137] The preparation process of Comparative Example 4 is the same as that of Example 1.

[0138] The materials prepared in Examples 1-6 and Comparative Examples 1-4 were subjected to performance tests, and the test methods for various properties were as follows:

[0139] (1) Density determination method: Determined in accordance with GB / T533-1991.

[0140] (2) Shore hardness test method: Tested in accordance with GB / T531.1-2008.

[0141] (3) Tensile strength determination method: Determined in accordance with GB / T528-2009.

[0142] (4) Elongation at break: Determined in accordance with GB / T528-2009.

[0143] (5) Compression set determination method: Determined in accordance with GB / T7759.1-2015.

[0144] The performance test results of the TPV materials prepared in Examples 1-6 and Comparative Examples 1-4 are shown in Table 1:

[0145] Table 1 Performance test results of embodiments and comparative examples

[0146]

[0147] It can be seen from Table 1 that the TPV materials containing recycled polypropylene foam prepared in Examples 1-6 have lower density and better mechanical properties.

[0148] In Comparative Example 1, the foaming agent used is AC foaming agent, and the pore size of the prepared TPV is larger and non-uniform. Although the density is smaller, its physical and mechanical properties are poor.

[0149] In Comparative Example 2, ultrafine calcium carbonate is used alone as a filler, which causes agglomeration of the filler and affects the foaming and vulcanization processes.

[0150] It can be seen from Comparative Examples 2-3 that the performance of the prepared foamed TPV material will be reduced when ultrafine calcium carbonate or carbon black is used alone, or ordinary calcium carbonate-carbon black is used as filler.

[0151] In summary, the foamed TPV material containing recycled polypropylene provided by the present invention can reduce the weight of the TPV material and achieve the purpose of lightweighting the material; at the same time, although recycled polypropylene is used as the raw material, the enhanced modification of the filler ultimately enables the product to still maintain good mechanical properties, which can meet the use requirements of automobile sealing strips and bring a more sound-insulating, energy-saving and environmentally friendly experience to the car.

[0152] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims

1. A foamed TPV material for automobile sealing strips containing recycled polypropylene, characterized in that: include, EPDM rubber, recycled polypropylene, filler, filler oil, vulcanizer, co-vulcanizer, foaming agent and antioxidant; Calculated by weight of each raw material, the EPDM rubber is 100 parts, the recycled polypropylene is 40-60 parts, the filler is 40-60 parts, the filler oil is 60-80 parts, the vulcanizer is 1-3 parts, the co-vulcanizer is 0.5-1 part, the foaming agent is 2-4 parts, and the antioxidant is 0.5-1 part.

2. The TPV material according to claim 1, characterized in that: The filler is a composition of ultrafine calcium carbonate and carbon black, and the mass ratio thereof is 1:

1.

3. The TPV material according to claim 1 or 2, characterized in that: The filler oil is one of paraffin oil and naphthenic oil.

4. The TPV material according to claim 3, characterized in that: The vulcanizing agent is one of dicumyl peroxide and di-tert-butylcumyl peroxide or a combination thereof.

5. The TPV material according to claim 4, characterized in that: The co-vulcanizing agent is triallyl isocyanate.

6. The TPV material according to claim 5, characterized in that: The foaming agent is Expancel920DU40 microsphere foaming agent.

7. The TPV material according to claim 6, characterized in that: The antioxidant is a hindered phenol antioxidant, including 2-6 di-tert-butyl-4-methylphenol.

8. The method for preparing the TPV material according to any one of claims 1 to 7, characterized in that: include, Add recycled polypropylene, EPDM rubber, filler, filler oil and antioxidant, which account for 2 / 3 of the weight of recycled polypropylene, into a mixer and mix evenly, and then send into a twin-screw extruder for extrusion granulation to obtain semi-finished product particles a; The remaining 1 / 3 weight of the recycled polypropylene is mixed evenly with the vulcanizing agent and the co-vulcanizing agent, and then sent to a twin-screw extruder for extrusion granulation to obtain semi-finished product particles b; The particles a, particles b and microsphere foaming agent are mixed and then fed into a twin-screw extruder. After extrusion, the mixture is cooled and shaped to obtain a foamed TPV material for automobile sealing strips.

9. The preparation method according to claim 7, characterized in that: The extrusion parameters of the twin-screw extruder for preparing the semi-finished particles a are: The operating temperature of the twin-screw extruder is 170-210°C, and the screw speed is 300-350rpm; The screw extruder extrusion parameters for preparing the semi-finished particles b are: The operating temperature of the twin-screw extruder is 160-190°C, and the screw speed is 250-300rpm.

10. The preparation method according to claim 7, characterized in that: The particles a, particles b and microsphere foaming agent are mixed and then fed into a twin-screw extruder, wherein the operating temperature of the twin-screw extruder is 170-180° C. and the screw speed is 250-300 rpm.

Images