Thermoplastic vulcanized rubber, preparation method thereof, sealing strip and container

Abstract

The invention relates to thermoplastic vulcanized rubber and a preparation method thereof, a sealing strip and a container. The thermoplastic vulcanized rubber is prepared from the following raw materials in percentage by weight: 20 to 40 percent of ethylene propylene diene monomer, 10 to 25 percent of polypropylene, 4 to 10 percent of polyphenyl ether, 5 to 25 percent of styrene thermoplastic elastomer, 1 to 6 percent of vulcanizing agent, 3 to 5 percent of compatilizer and 20 to 40 percent of filling oil. According to the thermoplastic vulcanized rubber disclosed by the invention, through the matching of the preparation raw materials, the thermoplastic vulcanized rubber has excellent tensile strength and also shows a relatively low compression set rate.

Description

Technical Field

[0001] The present application relates to the field of rubber, and particularly to a thermoplastic vulcanizate, a preparation method thereof, a sealing strip, and a container. Background Art

[0002] When ethylene propylene diene monomer (EPDM) rubber is used as a sealing strip material, the EPDM raw rubber often needs to be mixed with a reinforcing material, carbon black, clay, a softening agent, and other auxiliary materials. This process requires high-temperature vulcanization, has a complex processing technology, and the high-temperature vulcanization process has an odor. The waste materials cannot be recycled and are difficult to degrade, which is not conducive to promoting green development.

[0003] A thermoplastic vulcanizate refers to a high molecular elastomer material prepared by using plastic as the continuous phase and rubber as the dispersed phase through a dynamic vulcanization process with polypropylene and EPDM rubber. The thermoplastic vulcanizate has the characteristics of easy processing of plastic. Compared with the processing of EPDM rubber, the thermoplastic vulcanizate can omit the rubber mixing section in the front stage of processing and the vulcanization section in the later stage, and the scraps can be recycled; moreover, the production process of the thermoplastic vulcanizate has little pollution and high production efficiency, and has the advantages of energy conservation and environmental protection.

[0004] However, traditional thermoplastic vulcanizate materials are difficult to simultaneously achieve high tensile strength performance and low compression set rate, and it is difficult to widely promote thermoplastic vulcanizate materials in some industries with high requirements for material performance. Summary of the Invention

[0005] Based on this, it is necessary to provide a thermoplastic vulcanizate, a preparation method thereof, a sealing strip, and a container to overcome the disadvantage that traditional thermoplastic vulcanizate materials are difficult to balance high tensile strength performance and low compression set rate.

[0006] In the first aspect of the present application, a thermoplastic vulcanizate is provided.

[0007] A thermoplastic vulcanizate, in terms of weight percentage, the preparation raw materials of the thermoplastic vulcanizate include:

[0008] Ethylene propylene diene monomer (EPDM) rubber 20% - 40%;

[0009] Polypropylene 10% - 25%;

[0010] Polyphenylene ether 4% - 10%;

[0011] Styrenic thermoplastic elastomer 5% - 25%;

[0012] Vulcanizing agent 1% - 6%;

[0013] Compatibilizer 3% - 5%; and

[0014] Filling oil 20% - 40%.

[0015] In some embodiments, the styrenic thermoplastic elastomer includes one or more of styrene-ethylene-butene-styrene triblock copolymer, styrene-isoprene-styrene triblock copolymer, and styrene-ethylene-isoprene-styrene triblock copolymer.

[0016] In some embodiments, the compatibilizer includes one or both of polypropylene grafted maleic anhydride and ethylene propylene diene monomer grafted maleic anhydride.

[0017] In some embodiments, based on the mass percentage of the vulcanizing agent, the vulcanizing agent includes 70% - 90% of the main vulcanizing agent and 10% - 30% of the co-vulcanizing agent;

[0018] The main vulcanizing agent includes a peroxide vulcanizing agent or a phenolic vulcanizing agent;

[0019] The co-vulcanizing agent includes one or more of triglycidyl isocyanurate, trimethylolpropane trimethacrylate, stannous chloride dihydrate, stearic acid, and zinc oxide.

[0020] In the second aspect of the present application, a method for preparing the above-mentioned thermoplastic vulcanizate is provided.

[0021] A method for preparing the above-mentioned thermoplastic vulcanizate, comprising the following steps:

[0022] Based on the mass percentage of the filling oil, the filling oil is divided into 10% - 40% of the first filling oil and the remaining second filling oil;

[0023] Mix the first filling oil with the styrenic thermoplastic elastomer to form a first oil-filled material;

[0024] Mix the second filling oil, the polypropylene, the ethylene propylene diene monomer, and the polyphenylene ether to form a second oil-filled material;

[0025] Mix 25% - 50% of the vulcanizing agent based on the mass percentage of the vulcanizing agent with the first oil-filled material, the second oil-filled material, and the compatibilizer, and perform primary vulcanization to form a pre-vulcanized rubber; mix the pre-vulcanized rubber with the remaining vulcanizing agent, and perform secondary vulcanization to form the thermoplastic vulcanizate.

[0026] In some embodiments, the mass ratio of the second filling oil to the ethylene propylene diene monomer is 1:(0.8 - 1.5).

[0027] In some embodiments, the primary vulcanization is carried out in a twin-screw extruder, and the process parameters of the twin-screw extruder include one or more of the following conditions:

[0028] (1)The host speed is 200 r / min to 300 r / min;

[0029] (2)The temperature in zones 1 to 4 is 150 °C to 170 °C;

[0030] (3)The temperature from zone 5 to the extrusion die is 180 °C to 200 °C.

[0031] In some embodiments, the secondary vulcanization is carried out in a twin-screw extruder, and the process parameters of the twin-screw extruder include one or more of the following conditions:

[0032] (1)The host speed is 300 r / min to 400 r / min;

[0033] (2)The temperature in zones 1 to 4 is 150 °C to 170 °C;

[0034] (3)The temperature from zone 5 to the extrusion die is 180 °C to 240 °C.

[0035] In the third aspect of the present application, a sealing strip is provided, and at least a part of the sealing strip has the above-mentioned thermoplastic vulcanizate.

[0036] In the fourth aspect of the present application, a container is provided, and the container includes the above-mentioned sealing strip.

[0037] The preparation raw materials of the thermoplastic vulcanizate of the present application include a combination of ethylene propylene diene monomer (EPDM), polypropylene, polyphenylene ether, styrene-based thermoplastic elastomer, vulcanizing agent, filling oil, and compatibilizer. Among them, EPDM as the rubber phase endows the thermoplastic vulcanizate with good elasticity, and polypropylene as the plastic phase endows the thermoplastic vulcanizate with better tensile resistance. On this basis, by introducing polyphenylene ether and styrene-based thermoplastic elastomer, the properties of the plastic phase and the rubber phase are further balanced and exerted; at the same time, by introducing a compatibilizer, the tendency of polyphenylene ether and styrene-based thermoplastic elastomer to separate in the system is effectively reduced, so that the continuous phase (plastic phase) and the dispersed phase (rubber phase) of the thermoplastic vulcanizate are not easily separated and broken, and thus the thermoplastic vulcanizate exhibits a low compression set rate while having excellent tensile strength.

[0038] The preparation method of the thermoplastic vulcanizate of the present application regulates the oil filling method, oil filling degree, vulcanization method, and vulcanizing agent addition amount in the vulcanization stage, achieving the effect of optimizing the dynamic vulcanization process of the thermoplastic vulcanizate material, which helps to obtain a thermoplastic vulcanizate with high vulcanization degree, good component compatibility, and uniform dispersion. Detailed Embodiments

[0039] To make the above objects, features, and advantages of the present application more apparent and understandable, the following provides a detailed description of the specific embodiments of the present application. Many specific details are set forth in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0040] In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. In the present application, the meaning of "at least one" is more than one, such as one, two, and more than two. The meaning of "a variety" or "several" is at least two, such as two, three, etc.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs. The terms used in the description of the present application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0042] When a numerical range is disclosed herein, the above range is considered continuous and includes the minimum and maximum values of the range, as well as each value therebetween. Further, when the range refers to an integer, each integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0043] If there is no special indication, all steps of the present application can be carried out sequentially or randomly. For example, the method includes steps (a) and (b), which means that the method can include steps (a) and (b) carried out sequentially, or can also include steps (b) and (a) carried out sequentially. For example, it is mentioned that the method may further include step (c), which means that step (c) can be added to the method in any order. For example, the method can include steps (a), (b), and (c) in sequence, or can also include steps (a), (c), and (b), or can also include steps (c), (a), and (b), etc.

[0044] In the present application, "above" or "below" both include the number itself. For example, below 1 includes 1.

[0045] The temperature parameter in this application, unless otherwise specified, allows for both constant temperature treatment and variation within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within ranges such as ±5°C, ±4°C, ±3°C, ±2°C, ±1°C are allowed.

[0046] Traditional thermoplastic vulcanizate materials are difficult to simultaneously achieve high tensile strength performance and low compression set rate.

[0047] Based on this, it is necessary to provide a thermoplastic vulcanizate, its preparation method, and a sealing strip to overcome the drawback that traditional thermoplastic vulcanizate materials are difficult to balance high tensile strength performance and low compression set rate.

[0048] In the first aspect of this application, a thermoplastic vulcanizate is provided.

[0049] In terms of weight percentage, the raw materials for preparing the thermoplastic vulcanizate include 20% - 40% of ethylene propylene diene monomer (EPDM), 10% - 25% of polypropylene, 4% - 10% of polyphenylene ether, 5% - 25% of styrenic thermoplastic elastomer, 1% - 6% of vulcanizing agent, 3% - 5% of compatibilizer, and 20% - 40% of filling oil. Among them, choosing EPDM as the rubber phase helps to improve the elasticity of the thermoplastic vulcanizate; choosing polypropylene as the plastic phase helps to improve properties such as the mechanical strength and heat resistance of the thermoplastic vulcanizate. On this basis, by introducing polyphenylene ether and styrenic thermoplastic elastomer, it helps to further balance and exert the properties of the plastic phase and the rubber phase. At the same time, through the introduction of the compatibilizer, the tendency of polyphenylene ether and styrenic thermoplastic elastomer to separate in the melt is effectively reduced, making it difficult for the continuous phase (plastic phase) and the dispersed phase (rubber phase) of the thermoplastic vulcanizate to separate and break. As a result, the thermoplastic vulcanizate exhibits excellent tensile strength while showing a low compression set rate.

[0050] Optionally, in the raw materials for preparing the thermoplastic vulcanizate, the content of EPDM can be 20%, 25%, 30%, 35%, 40% or other values within 20% - 40%.

[0051] Optionally, in the raw materials for preparing the thermoplastic vulcanizate, the content of polypropylene can be 10%, 12%, 15%, 18%, 20%, 22%, 23%, 24%, 25% or other values within 10% - 25%.

[0052] In some of these embodiments, the Mooney viscosity (ML1+4, 125 °C) of the ethylene propylene diene monomer rubber is 60 to 120. Optionally, the Mooney viscosity (ML1+4, 125 °C) of the ethylene propylene diene monomer rubber can be 60, 70, 80, 90, 100, 110, 120 or any value within the range of 60 to 120.

[0053] When the viscosity of the ethylene propylene diene monomer rubber is within the above range, it helps to maintain a suitable viscosity relationship between the phases, so as to obtain better compatibility, and then obtain a uniformly dispersed phase structure.

[0054] In some of these embodiments, the ethylene propylene diene monomer rubber includes granular ethylene propylene diene monomer rubber with an ethylene content of 60% to 80% and an ENB content of 4% to 5%.

[0055] In some of these embodiments, the ethylene propylene diene monomer rubber includes one or both of ExxonMobil's EPDM 5601 and EPMD 7001.

[0056] In some of these embodiments, the polypropylene includes homopolymer polypropylene with a melt index of 0.5 g / 10 min to 3 g / 10 min (230 °C, 2.16 kg). Keeping the melt index of the polypropylene within the above range helps to maintain a suitable viscosity relationship between the systems during processing, so as to obtain better compatibility, and then obtain a uniformly dispersed phase structure.

[0057] Optionally, in the raw materials for preparing the thermoplastic vulcanizate, the content of polyphenylene ether can be 4%, 5%, 6%, 7%, 8%, 9%, 10% or other values within the range of 4% to 10%. Polyphenylene ether has a relatively high glass transition temperature and melting point, and can maintain stable properties at high temperatures. In addition, the characteristics of large rigidity and high strength of polyphenylene ether can effectively resist deformation at high temperatures, which helps to improve the high-temperature resilience and tensile strength of the thermoplastic vulcanizate material.

[0058] In some of these embodiments, the intrinsic viscosity of the polyphenylene ether is 0.35 dl / g to 0.45 dl / g. Keeping the viscosity of the polyphenylene ether within the above range helps to maintain a suitable viscosity relationship between the phases, so as to obtain better compatibility, and then obtain a uniformly dispersed phase structure. Optionally, the intrinsic viscosity of the polyphenylene ether can be 0.35 dl / g, 0.4 dl / g, 0.45 dl / g or other parameters within the range of 0.35 dl / g to 0.45 dl / g.

[0059] In some of these embodiments, the polyphenylene ether is in powder form, and the powder mesh number is 100 mesh to 500 mesh. Optionally, the powder mesh number of the polyphenylene ether can be 100 mesh, 200 mesh, 300 mesh, 400 mesh, 500 mesh or other parameters within the range of 100 mesh to 500 mesh.

[0060] Optionally, in the raw materials for preparing the thermoplastic vulcanizate, the content of the styrenic thermoplastic elastomer can be 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, or other values within 5% - 25%.

[0061] In some embodiments, the styrenic thermoplastic elastomer includes one or more of styrene - ethylene - butylene - styrene triblock copolymer (SEBS), styrene - isoprene - styrene triblock copolymer (SEPS), and styrene - ethylene - isoprene - styrene triblock copolymer (SEEPS).

[0062] In some embodiments, the styrenic thermoplastic elastomer includes SEBS with a number - average molecular weight of 250,000 - 400,000 and a styrene content of 30% - 40%. Selecting SEBS with a styrene content of 30% - 40% helps to improve the overall hardness and crystallinity; when the molecular weight of SEBS is 250,000 - 400,000, due to the high molecular weight, the molecular chain movement is restricted, and it is not easy to generate deformation under external force, which helps to improve the compression set resistance and tensile strength of the thermoplastic vulcanizate.

[0063] Optionally, the content of the compatibilizer can be 3%, 4%, 5%, or other values within 3% - 5%. The raw materials for preparing the thermoplastic vulcanizate include various materials. The addition of the compatibilizer helps to further form an integral and tightly - bound whole of various components in the thermoplastic vulcanizate, reducing the tendency of low - molecular - weight polymer components to separate from the melt. In addition, improving compatibility also helps to reduce the generation of slag due to die friction during the extrusion molding of the thermoplastic vulcanizate material and avoid the problem of die slag accumulation.

[0064] In some embodiments, the compatibilizer includes one or two of polypropylene grafted maleic anhydride (polypropylene - G - MAH) and ethylene - propylene - diene monomer rubber grafted maleic anhydride (EPDM - G - MAH).

[0065] Optionally, in the raw materials for preparing the thermoplastic vulcanizate, the content of the vulcanizing agent can be 1%, 2%, 3%, 4%, 5%, 6%, or other values within 1% - 6%.

[0066] In some embodiments, calculated by mass percentage of the vulcanizing agent, the vulcanizing agent includes 30% - 70% of the main vulcanizing agent and 30% - 70% of the co - vulcanizing agent.

[0067] In some embodiments, the main vulcanizing agent includes a peroxide vulcanizing agent or a phenolic vulcanizing agent. Optionally, the phenolic vulcanizing agent includes octylphenol formaldehyde resin.

[0068] In some of these embodiments, the co-vulcanizing agent includes one or more of triglycidyl isocyanurate (TGIC), trimethylolpropane trimethacrylate (TMPTMA), stannous chloride dihydrate, stearic acid, and zinc oxide. During the dynamic vulcanization of thermoplastic vulcanizate, if only phenolic resin is used for the vulcanization reaction, the vulcanization rate is slow and the degree of vulcanization is not high. Adding a catalyst can not only increase the vulcanization rate but also improve the degree of vulcanization, which helps to reduce the compression set rate of thermoplastic vulcanizate.

[0069] In some of these embodiments, based on the mass parts of the co-vulcanizing agent, the co-vulcanizing agent includes 2 - 4 parts of stannous chloride dihydrate, 3 - 5 parts of zinc oxide, and 3 - 5 parts of stearic acid. Zinc oxide can absorb hydrogen chloride generated during vulcanization, accelerate the vulcanization reaction, increase the crosslinking degree of the rubber, and enhance the physical and mechanical properties of thermoplastic vulcanizate; stearic acid, as a vulcanization activator, can react with zinc oxide to form zinc soap, help control the vulcanization process, affect the formation of the crosslinking network, and thus affect the physical properties such as the hardness and elasticity of the rubber.

[0070] Optionally, in the preparation raw materials of thermoplastic vulcanizate, the content of the filling oil can be 20%, 25%, 30%, 35%, 40%, or other values within 20% - 40%. The filling oil can lubricate the molecular chains and improve the fluidity and processing performance of the preparation raw materials.

[0071] In some of these embodiments, the filling oil includes one or both of white oil and paraffin oil.

[0072] In some of these embodiments, the filling oil uses paraffin oil with a kinematic viscosity of 60 mm 2 / s - 150 mm 2 / s and an open flash point greater than 230°C. Maintaining the filling oil at the above viscosity helps to improve the processing performance of the preparation raw materials.

[0073] In some of these embodiments, the filling oil is divided into a first filling oil and a second filling oil. Based on the mass percentage of the filling oil, the content of the first filling oil is 10% - 40%, and the balance is the second filling oil.

[0074] In some of these embodiments, the mass ratio of the first filling oil to the styrenic thermoplastic elastomer is 1:(0.5 - 2).

[0075] In some of these embodiments, the mass ratio of the second filling oil to the ethylene propylene diene monomer rubber is 1:(0.8 - 1.5).

[0076] In some of these embodiments, the raw materials for preparing the thermoplastic vulcanizate further include 1% to 5% of an auxiliary agent by weight percentage. Optionally, in the raw materials for preparing the thermoplastic vulcanizate, the content of the auxiliary agent can be 1%, 2%, 3%, 4%, 5% or other values within 1% to 5%.

[0077] In some of these embodiments, the auxiliary agent includes one or more of a lubricant, an antioxidant, and a light stabilizer.

[0078] In some of these embodiments, the raw materials for preparing the thermoplastic vulcanizate include 20% to 35% of ethylene propylene diene monomer rubber, 15% to 20% of polypropylene, 4% to 10% of polyphenylene ether, 5% to 20% of styrenic thermoplastic elastomer, 1% to 3% of a vulcanizing agent, 3% to 5% of a compatibilizer, 30% to 40% of a filling oil, and 1% to 5% of an auxiliary agent, all by weight percentage.

[0079] In the second aspect of the present application, a method for preparing the above-mentioned thermoplastic vulcanizate is provided.

[0080] The method for preparing the thermoplastic vulcanizate includes the following steps:

[0081] Taking the mass percentage of the filling oil as a basis, the filling oil is divided into 10% to 40% of a first filling oil and the remaining second filling oil;

[0082] Mix the first filling oil with the styrenic thermoplastic elastomer to form a first oil-filled material;

[0083] Mix the second filling oil, polypropylene, ethylene propylene diene monomer rubber, and polyphenylene ether to form a second oil-filled material;

[0084] Mix 25% to 50% of the vulcanizing agent by mass percentage of the vulcanizing agent with the first oil-filled material, the second oil-filled material, and the compatibilizer, and perform primary vulcanization to form a pre-vulcanized rubber;

[0085] Mix the pre-vulcanized rubber with the remaining vulcanizing agent, and perform secondary vulcanization to form a thermoplastic vulcanizate.

[0086] In some of these embodiments, the mass ratio of the first filling oil to the styrenic thermoplastic elastomer is 1:(0.5 to 2).

[0087] In some of these embodiments, the mass ratio of the second filling oil to the ethylene propylene diene monomer rubber is 1:(0.8 to 1.5).

[0088] The method for preparing the thermoplastic vulcanizate of the present application helps to obtain a thermoplastic vulcanizate with high vulcanization degree, good component compatibility, and uniform dispersion by precisely controlling the oil filling method, oil filling degree, vulcanization method, and vulcanizing agent addition amount during the vulcanization stage.

[0089] The addition amount of the vulcanizing agent has a great influence on the dynamic vulcanization of thermoplastic vulcanizate. By adopting the above-mentioned stepwise vulcanization method and the setting of the addition amount of the vulcanizing agent, the vulcanization speed can be effectively controlled, ensuring that the rubber particles can be sheared into particles with a micron-sized dimension, which is beneficial to improving the crosslinking density and physical and mechanical properties of the product and reducing the compression set rate.

[0090] In some of the embodiments, the first filling oil and the styrenic thermoplastic elastomer are mixed in a stirring pot to form a first oil-filled material.

[0091] In some of the embodiments, the second filling oil, polypropylene, ethylene-propylene-diene monomer rubber and polyphenylene ether are mixed by a twin-screw extruder to form a second oil-filled material.

[0092] In some of the embodiments, polypropylene, ethylene-propylene-diene monomer rubber and polyphenylene ether are first mixed evenly and then poured into the main feeding barrel of the twin-screw extruder. The second filling oil is injected from the third zone of the twin-screw by a metering oil pump, and after oil filling, it is extruded and pelletized to form a second oil-filled material. Among them, the main machine speed of the twin-screw extruder is 200 r / min to 300 r / min, and the melting temperature is 200 °C to 230 °C.

[0093] In some of the embodiments, the ratio of the length to the diameter of the screw of the twin-screw extruder is 48:80. In the screw combination of the twin-screw extruder, one reverse-thread element is arranged in the fourth to sixth zones to enhance the shearing and processing ability of the material.

[0094] In some of the embodiments, the primary vulcanization is carried out in a twin-screw extruder. When carrying out the primary vulcanization, the process parameters of the twin-screw extruder include one or more of the following conditions:

[0095] (1) The main machine speed is 200 r / min to 300 r / min;

[0096] (2) The temperature of the first to fourth zones is 150 °C to 170 °C;

[0097] (3) The temperature of the fifth zone to the extrusion outlet is 180 °C to 200 °C.

[0098] In some of the embodiments, the steps of the primary vulcanization include: after mixing 25% to 50% of the vulcanizing agent by mass percentage of the vulcanizing agent with the first oil-filled material, the second oil-filled material and the compatibilizer, pouring them into the main feeding barrel of the twin-screw extruder, and through the process control of the extruder, pre-vulcanized rubber is obtained.

[0099] In some of the embodiments, the secondary vulcanization is carried out in a twin-screw extruder. When carrying out the secondary vulcanization, the process parameters of the twin-screw extruder include one or more of the following conditions:

[0100] (1)The rotational speed of the main engine is 300 r / min to 400 r / min;

[0101] (2)The temperatures in the first to fourth zones are 150 °C to 170 °C;

[0102] (3)The temperatures from the fifth zone to the extrusion outlet are 180 °C to 240 °C.

[0103] In some of the embodiments, the steps of secondary vulcanization include: uniformly mixing the pre-vulcanized rubber with the remaining vulcanizing agent, pouring it into the main feeding barrel of a twin-screw extruder, and obtaining thermoplastic vulcanized rubber through process control of the extruder.

[0104] In the third aspect of the present application, a sealing strip is provided. At least a part of the sealing strip has the above-mentioned thermoplastic vulcanized rubber.

[0105] In the fourth aspect of the present application, a container is provided, including the sealing strip of the third aspect.

[0106] In some of the embodiments, the performance of the sealing strip meets the performance requirements for tensile strength and compression set in "GB / T 15846-2006 Container Door Frame Sealing Strip" and can be used as a container door frame sealing strip.

[0107] The following further elaborates on the present application in combination with specific embodiments.

[0108] In the following specific embodiments and comparative examples, unless otherwise specified, the raw materials used are commercially available products; the instruments used, unless otherwise specified, are commercially available products; the processes used, unless otherwise specified, are the conventional selections of those skilled in the art.

[0109] Example 1

[0110] This example provides a thermoplastic vulcanized rubber material.

[0111] The mass percentages of the raw materials for preparing the thermoplastic vulcanized rubber are shown in Table 1. Among them, the filling oil is paraffin oil with a kinematic viscosity of 120 mm 2 / s and an open flash point of 265 °C; the ethylene-propylene-diene monomer rubber is EPDM 5601 of ExxonMobil; the polypropylene is PPH-T03 (homopolymer polypropylene) of Sinopec; the polyphenylene ether is powdery polyphenylene ether with an intrinsic viscosity of 0.4 dl / g; the styrenic thermoplastic elastomer is styrene-ethylene-butene-styrene triblock copolymer (the content of styrene is 35%); the vulcanizing agent is composed of 40% octylphenol formaldehyde resin, 15% stannous chloride dihydrate, 22% zinc oxide, and 23% stearic acid; the compatibilizer is polypropylene grafted maleic anhydride; the auxiliary agents are lubricants, antioxidants, and light stabilizers.

[0112] The preparation process of the thermoplastic vulcanized rubber material is as follows:

[0113] The filling oil is divided into a first filling oil and a second filling oil, and the first filling oil accounts for 22% of the mass of the filling oil.

[0114] The first filling oil and the styrenic thermoplastic elastomer are mixed by a stirring pot to form a first oil-filled material.

[0115] The polypropylene, ethylene-propylene-diene monomer rubber and polyphenylene ether are uniformly mixed and poured into the main feeding barrel of a twin-screw extruder. The second filling oil is injected from the third zone of the twin-screw through a metering oil pump. After oil filling, pelletizing is carried out to form a second oil-filled material. Vulcanization is carried out using a twin-screw extruder. 35% of the vulcanizing agent by mass is mixed with the first oil-filled material, the second oil-filled material and the compatibilizer, and poured into the main feeding barrel of the twin-screw extruder. Through the process control of the twin-screw extruder, pre-vulcanized rubber (primary vulcanization) is obtained.

[0116] The pre-vulcanized rubber is mixed with the remaining vulcanizing agent and poured into the main feeding barrel of the twin-screw extruder. Through the process control of the extruder, thermoplastic vulcanizate (secondary vulcanization) is formed.

[0117] In the above process, the ratio of the length to the diameter of the screw of the twin-screw extruder is 48:80; one reverse-thread element is arranged in the fourth to sixth zones of the twin-screw extruder.

[0118] When carrying out primary vulcanization, the process parameters of the twin-screw extruder are: the main machine speed is 250 r / min, and the temperatures of the first to fourth zones are 150 °C, 160 °C, 165 °C and 170 °C in sequence, and the temperatures of the fifth zone to the extrusion outlet are 180 °C, 190 °C, 200 °C, 200 °C, 200 °C, 200 °C, 200 °C and 200 °C in sequence.

[0119] When carrying out secondary vulcanization, the process parameters of the twin-screw extruder are: the main machine speed is 350 r / min, and the temperatures of the first to fourth zones are 150 °C, 160 °C, 165 °C and 170 °C in sequence, and the temperatures of the fifth zone to the extrusion outlet are 180 °C, 190 °C, 200 °C, 210 °C, 220 °C, 230 °C, 240 °C and 220 °C in sequence.

[0120] Example 2

[0121] This example provides a thermoplastic vulcanizate material.

[0122] The preparation raw materials and the preparation method of this example are basically the same as those of Example 1, the difference being that: the polyphenylene ether is increased to 9%, and the ethylene-propylene-diene monomer rubber is reduced to 25%.

[0123] Example 3

[0124] This example provides a thermoplastic vulcanizate material.

[0125] The preparation raw materials and preparation method of this example are basically the same as those of Example 1, with the differences being that the styrenic thermoplastic elastomer is increased to 20% and the ethylene propylene diene monomer (EPDM) rubber is decreased to 20%.

[0126] Example 4

[0127] The preparation raw materials and preparation method of this example are basically the same as those of Example 1, with the differences being that the styrenic thermoplastic elastomer is decreased to 5% and the EPDM rubber is increased to 35%.

[0128] Example 5

[0129] The preparation raw materials and preparation method of this example are basically the same as those of Example 1, with the differences being that the styrenic thermoplastic elastomer is increased to 20%, the polyphenylene ether is increased to 9%, the EPDM rubber is decreased to 20%, and the polypropylene is decreased to 12%.

[0130] Example 6

[0131] The preparation raw materials and preparation method of this example are basically the same as those of Example 1, with the differences being that the styrenic thermoplastic elastomer is increased to 25%, the EPDM rubber is decreased to 20%, and the polypropylene is decreased to 12%.

[0132] Example 7

[0133] The preparation raw materials and preparation method of this example are basically the same as those of Example 1, with the difference being that stepwise vulcanization is not carried out, and all raw materials are processed with the parameters set for secondary vulcanization.

[0134] Comparative Example 1

[0135] The preparation raw materials and preparation method of this comparative example are basically the same as those of Example 1, with the difference being that polyphenylene ether is not added and the proportion of filling oil is increased to 36%.

[0136] Comparative Example 2

[0137] The preparation raw materials and preparation method of this comparative example are basically the same as those of Example 1, with the difference being that styrenic thermoplastic elastomer is not added and the proportions of filling oil and EPDM rubber are increased.

[0138] Comparative Example 3

[0139] The preparation raw materials and preparation method of this comparative example are basically the same as those of Example 1, with the differences being that the content of polyphenylene ether is increased to 14%, the EPDM rubber is decreased to 23%, and the polypropylene is decreased to 14%.

[0140] The formulation compositions of the examples and comparative examples are shown in Table 1, and the performance test results are shown in Table 2.

[0141] Table 1

[0142]

[0143] Table 2

[0144]

[0145] As can be seen from Table 2, in this application, through the combination of ethylene propylene diene monomer rubber, polyphenylene ether, polypropylene, styrene thermoplastic elastomer, vulcanizing agent, filling oil and compatibilizer with specific contents, and through the precise regulation of the oil filling method, oil filling degree, vulcanization method and vulcanizing agent addition amount in the vulcanization stage, while ensuring that the thermoplastic vulcanizate material has excellent tensile strength, the compression set rate of the thermoplastic vulcanizate is effectively reduced, which is beneficial to expanding the application range of the thermoplastic vulcanizate material.

[0146] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0147] The above-described embodiments only represent several implementation manners of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application patent shall be subject to the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A thermoplastic vulcanized rubber, characterized in that: In terms of weight percentage, the raw materials for preparing the thermoplastic vulcanizate include: EPDM 20%~40%; Polypropylene 10%~25%; Polyphenylene ether 4%~10%; Styrene thermoplastic elastomer 5%~25%; Vulcanizing agent 1%~6%; Compatibilizer 3%~5%; and Filler oil 20%~40%.

2. The thermoplastic vulcanizate according to claim 1, characterized in that The styrene-based thermoplastic elastomer includes one or more of a styrene-ethylene-butylene-styrene triblock copolymer, a styrene-isoprene-styrene triblock copolymer, and a styrene-ethylene-isoprene-styrene triblock copolymer.

3. The thermoplastic vulcanizate according to claim 1, characterized in that The compatibilizer includes one or two of polypropylene grafted with maleic anhydride and ethylene propylene diene monomer rubber grafted with maleic anhydride.

4. The thermoplastic vulcanizate according to any one of claims 1 to 3, characterized in that The vulcanizing agent comprises 70% to 90% of a main vulcanizing agent and 10% to 30% of an auxiliary vulcanizing agent, in terms of mass percentage of the vulcanizing agent; The main vulcanizing agent includes a peroxide vulcanizing agent or a phenolic vulcanizing agent; The co-vulcanizing agent includes one or more of triglycidyl isocyanurate, trimethylolpropane trimethacrylate, stannous chloride dihydrate, stearic acid and zinc oxide.

5. A method for preparing a thermoplastic vulcanizate according to any one of claims 1 to 4, characterized in that: The following steps are involved: The filler oil is divided into 10% to 40% of the first filler oil and the remainder of the second filler oil in terms of mass percentage of the filler oil; the first filler oil is mixed with the styrene-based thermoplastic elastomer to form a first filler oil; the second filler oil, the polypropylene, the EPDM rubber and the polyphenylene ether are mixed to form a second filler oil; The vulcanizer accounting for 25% to 50% of the mass percentage of the vulcanizer is mixed with the first oil-filled material, the second oil-filled material and the compatibilizer, and a pre-vulcanized rubber is formed through a primary vulcanization; the pre-vulcanized rubber is mixed with the remaining vulcanizer, and a thermoplastic vulcanized rubber is formed through a secondary vulcanization.

6. The method for preparing a thermoplastic vulcanizate according to claim 5, characterized in that: The mass ratio of the second filler oil to the EPDM rubber is 1:(0.8-1.5).

7. The method for preparing a thermoplastic vulcanizate according to claim 5 or 6, characterized in that: The primary vulcanization is carried out in a twin-screw extruder, and the process parameters of the twin-screw extruder include one or more of the following conditions: (1) The main engine speed is 200r / min~300r / min; (2) The temperature of zone 1 to zone 4 is 150℃~170℃; (3) The temperature from zone 5 to the extrusion outlet is 180℃~200℃.

8. The method for preparing a thermoplastic vulcanizate according to claim 5 or 6, characterized in that: The secondary vulcanization is carried out in a twin-screw extruder, and the process parameters of the twin-screw extruder include one or more of the following conditions: (1) The main engine speed is 300r / min~400r / min; (2) The temperature of zone 1 to zone 4 is 150℃~170℃; (3) The temperature from zone 5 to the extrusion outlet is 180℃~240℃.

9. A sealing strip, characterized in that: At least a portion of the sealing strip comprises the thermoplastic vulcanizate according to any one of claims 1 to 6.

10. A container, characterized in that: The container comprises the sealing strip of claim 9.

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