Thermoplastic vulcanized rubber as well as preparation method and application thereof

Abstract

The invention relates to thermoplastic vulcanized rubber as well as a preparation method and application thereof. The thermoplastic vulcanized rubber is prepared from the following raw materials in parts by weight: 8 to 40 parts of heat-resistant rubber, 60 to 90 parts of plastic, 1 to 6 parts of anti-ant agent and 0.1 to 3 parts of vulcanizing agent. The invention provides a drug aggregation type thermoplastic vulcanizate which takes cross-linked rubber as an island phase and plastic as a marine phase, and most of pesticides are aggregated in a dispersed rubber phase. The rubber is stable in property, and most of the pesticide is concentrated in a dispersed rubber phase by means of rapid shearing and crosslinking of the rubber in the processing process by means of good compatibility of the rubber and the pesticide; the dispersion phase material in the thermoplastic vulcanized rubber is used for wrapping the pesticide, so that the volatilization, decomposition, oxidation and loss rate of the pesticide in the environment can be effectively inhibited, the pesticide can play a role more enduringly, and the utilization rate of the pesticide is improved. In addition, the preparation process is simple, the preparation cost can be reduced, the preparation time can be shortened, and the preparation method has great application value in industrial production.

Description

Technical Field

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

[0002] Thermoplastic vulcanizates are a class of polymer materials that combine the elasticity of rubber and the processing characteristics of thermoplastic plastics. From the perspective of the development of materials, traditional rubber materials, although having good elasticity and flexibility, have complex processing processes, usually requiring irreversible chemical reactions such as vulcanization cross-linking, and are difficult to recycle. Thermoplastic plastics, on the other hand, are easy to process and recyclable, but lack the excellent toughness and touch of rubber. The emergence of thermoplastic vulcanizates fills the gap between the two. In addition, thermoplastic vulcanizates also have good processing properties. They can be rapidly formed by conventional processing methods such as injection molding, extrusion, and blow molding like thermoplastic plastics, greatly shortening the production cycle and improving production efficiency. Moreover, the recyclability of thermoplastic vulcanizates gives them significant advantages in resource recycling. Under the background of the global advocacy of sustainable development, this characteristic makes them more competitive in the market.

[0003] Thermoplastic vulcanizates have a wide range of applications in industries such as construction, wire and cable, and sports equipment. For example, thermoplastic vulcanizates can be used to manufacture heat insulation materials such as heat insulation boards and heat insulation pipes. Thermoplastic vulcanizates can also be used to manufacture the insulation layer and sheath layer of wire and cable. As cable materials, due to long-term contact with underground soil, in addition to ensuring the functional characteristics of these materials themselves, it is also necessary to ensure their protection against pests. To ensure the long-term effective protection of cable materials against pests, pesticides are generally added during the production process of these materials. However, the drug loss of cable materials directly mixed with pesticides is fast, resulting in a short service life. In recent years, microencapsulated pesticides can reduce the impact of the external environment on pesticides and also reduce the volatilization, decomposition, and loss of pesticides. However, by microencapsulating pesticides and then introducing them into cable materials, not only does the preparation process increase, but the production cost is also greatly increased. Summary of the Invention

[0004] Based on this, the object of the present application includes providing a drug-aggregated thermoplastic vulcanizate, which has stable properties, can enable drugs such as ant repellents to play a role more persistently, and at the same time has a simple preparation process, can reduce the preparation cost and shorten the preparation time.

[0005] The technical solution of the present application is as follows:

[0006] In the first aspect of the present invention, there is provided a thermoplastic vulcanizate, the raw materials of which include the following components in parts by weight: 8-40 parts of heat-resistant rubber, 60-90 parts of plastic, 1-6 parts of ant repellent, and 0.1-3 parts of vulcanizing agent.

[0007] In one embodiment, the heat-resistant rubber is one or more of ethylene-vinyl acetate rubber, silicone rubber, acrylate rubber, hydrogenated nitrile rubber, nitrile rubber, chlorinated polyethylene rubber, and ethylene propylene diene monomer rubber.

[0008] In one embodiment, the plastic is one or more of high-density polyethylene, low-density polyethylene, polypropylene, polyvinylidene fluoride, and polyvinyl chloride.

[0009] In one embodiment, the antifeedant is one or more of imidacloprid, bifenthrin, avermectin, thiamethoxam, cypermethrin, chlorpyrifos, and fipronil; and / or

[0010] The vulcanizing agent is one or more of dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, sulfur, silane coupling agent, trithiocyanuric acid, 2,4-dichlorobenzoyl peroxide, and tert-butyl perbenzoate.

[0011] In one embodiment, the raw materials of the thermoplastic vulcanizate further include at least one of an antioxidant and an antiozonant;

[0012] Optionally, the raw materials of the thermoplastic vulcanizate include the following components in parts by weight: 8-40 parts of heat-resistant rubber, 60-90 parts of plastic, 1-6 parts of antifeedant, 0.1-3 parts of vulcanizing agent, 0.1-0.5 parts of antioxidant, and 0.5-1 part of antiozonant.

[0013] In one embodiment, the antioxidant is at least one of antioxidant 1010, antioxidant 264, antioxidant 168, and antioxidant 1067; and / or

[0014] The antiozonant is at least one of antiozonant 4010NA, antiozonant ODA, and antioxidant 264.

[0015] In a second aspect of the present invention, there is provided a method for preparing the thermoplastic vulcanizate as described above, including the following steps:

[0016] Mix the heat-resistant rubber, antifeedant, and vulcanizing agent to prepare a premix;

[0017] Blend the premix and the plastic to prepare a rubber-plastic mixture;

[0018] Perform dynamic vulcanization processing on the rubber-plastic mixture.

[0019] In one embodiment, the step of dynamic vulcanization processing satisfies at least one of the following conditions:

[0020] (1) The temperature is 160°C - 230°C;

[0021] (2) The rotational speed is 30 rpm - 90 rpm;

[0022] (3) The time is 5 min - 10 min.

[0023] In the third aspect of the present invention, there is provided an insect - repellent and insecticidal chemical product, and the raw materials for its preparation include the thermoplastic vulcanizate as described above.

[0024] In the fourth aspect of the present invention, there is provided a cable, including a cable body and the insect - repellent and insecticidal chemical product as described above attached to the surface of the cable body.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] The present application provides a drug - aggregated thermoplastic vulcanizate with cross - linked rubber as the island phase, plastic as the sea phase, and most of the pesticides aggregated in the dispersed rubber phase. Its properties are stable. By virtue of the good compatibility between rubber and pesticides, during the processing, with the help of a rapid shearing and cross - linking of the rubber, most of the pesticides are concentrated in the dispersed rubber phase. After the dispersed - phase material in the thermoplastic vulcanizate wraps the pesticides, it can effectively inhibit the volatilization, decomposition, oxidation, and loss rates of the pesticides in the environment, enabling the pesticides to play a role more persistently, thereby improving the utilization rate of the pesticides.

[0027] In addition, the present application provides a preparation method of a drug - aggregated thermoplastic vulcanizate by using the technology of rubber - plastic blending and dynamic vulcanization. Its preparation process is simple, which can reduce the preparation cost and shorten the preparation time. This method can effectively extend the thermal stability performance and service life of the pesticides in the whole material after encapsulating the pesticides in a special and simple processing manner; it has great industrial practical value in the field of integrated production of polymer materials; compared with directly adding micro - encapsulated pesticides to the substrate, it saves the operation of drug micro - encapsulation and greatly reduces the cost. Moreover, this method is suitable for large - batch industrial preparation and has great application value in actual industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is the SEM diagram of the thermoplastic vulcanizate prepared in Example 1.

[0030] Figure 2Thermogravimetric curves of the thermoplastic vulcanizate prepared in Example 1 and the raw materials used.

[0031] Figure 3 SEM images of the thermoplastic vulcanizate prepared in Example 4.

[0032] Figure 4 Thermogravimetric curves of the thermoplastic vulcanizate prepared in Example 4 and the raw materials used.

[0033] Figure 5 SEM images and EDS maps of the composite material prepared in Comparative Example 1

[0034] Figure 6 SEM images and EDS maps of the composite material prepared in Comparative Example 2. Detailed implementation manners

[0035] To make the above objects, features, and advantages of the present application more obvious and understandable, the following provides a detailed description of the specific implementation manners 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.

[0036] 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 this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0037] Unless otherwise stated or there are contradictions, the terms or phrases used herein have the following meanings:

[0038] As used herein, "one or more" refers to any one, any two, or any two or more of the listed items.

[0039] In this text, the optional scope of "and / or", "or / and", "and / or" includes any one of two or more related listed items, and also includes any and all combinations of the related listed items. The said any and all combinations include any two related listed items, any more related listed items, or the combination of all related listed items. (It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or", "or / and", "and / or", it should be understood that in this application, this technical solution undoubtedly includes the technical solution connected by "logical AND", and also undoubtedly includes the technical solution connected by "logical OR". For example, "A and / or B" includes three parallel solutions: A, B, and A + B. Another example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, the technical solution connected by "logical OR"), and also includes any and all combinations of A, B, C, and D, that is, it includes the combination of any two or any three of A, B, C, and D, and also includes the four-item combination of A, B, C, and D (that is, the technical solution connected by "logical AND").

[0040] In this text, words such as "further", "even further", "especially", etc. are used for descriptive purposes, indicating differences in content, but should not be construed as limiting the scope of protection of this application.

[0041] In this text, "first aspect", "second aspect", "third aspect", "fourth aspect", etc. are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or quantity, nor can it be construed as implicitly indicating the importance or quantity of the indicated technical features. In addition, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. In the description of this application, the meaning of "several" is at least one, such as one, two, etc., unless otherwise specifically defined.

[0042] In this application, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are considered continuous and include the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Further, when the range refers to integers, it includes every integer between the minimum and maximum values of the range. In addition, when multiple ranges are provided to describe features or characteristics, these 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] This text specifically discloses only some numerical ranges. However, any lower limit can be combined with any upper limit to form a range not explicitly recited; and any lower limit can be combined with other lower limits to form a range not explicitly recited, and similarly any upper limit can be combined with any other upper limit to form a range not explicitly recited. In addition, each individually disclosed point or single numerical value itself can be used as a lower limit or an upper limit and combined with any other point or single numerical value or combined with other lower limits or upper limits to form a range not explicitly recited. The use of numerical ranges expressed by endpoints includes all the numbers within that range and any sub-ranges within that range. For example, the range from 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, etc.

[0044] In this application, unless otherwise specified, the percentage content for solid-liquid mixing and solid-solid mixing refers to mass percentage, and for liquid-liquid mixing refers to volume percentage.

[0045] In this application, unless otherwise specified, the percentage concentration refers to the final concentration. The final concentration refers to the proportion of the added component in the system after adding this component.

[0046] In this application, unless otherwise specified, the temperature parameter allows both isothermal treatment and treatment within a certain temperature range. The isothermal treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within ranges such as ±5°C, ±2°C, ±1°C, ±0.5°C, ±0.4°C, ±0.3°C, ±0.2°C, ±0.1°C are allowed. Normal temperature or room temperature in this application refers to the situation without applying temperature control operations, generally referring to 4°C to 35°C, preferably 20 ± 5°C.

[0047] In this application, for the technical features described in an open-ended manner, it includes both the closed technical solutions composed of the recited features and the open technical solutions including the recited features.

[0048] Thermoplastic vulcanizate is a special thermoplastic elastomer obtained through a dynamic vulcanization reaction processing technology. When a small amount of plastic phase is melt-blended with a large amount of rubber, the rubber undergoes chemical cross-linking under the action of a vulcanizing agent, and its viscosity increases. Therefore, under the action of high-temperature mechanical shear, the rubber-plastic blend undergoes inversion, and a large amount of rubber phase is broken into micron-sized particles and evenly dispersed in a small amount of plastic phase. After the rubber is cross-linked, a special sea-island structure is formed. This special structure enables thermoplastic vulcanizate to possess both the high elasticity and softness of traditional rubber, and also has the properties of thermoplastic processing and recyclability of plastics, and is gradually replacing traditional thermosetting rubber.

[0049] In recent years, microencapsulated pesticides can reduce the impact of the external environment on pesticides and also reduce pesticide volatilization, decomposition, and loss. However, introducing pesticides into cable materials through microencapsulation not only increases the preparation process but also significantly raises the production cost. Based on this, after extensive research, the technical personnel of this application unexpectedly discovered a thermoplastic vulcanizate composition in which rubber and plastic can form a "sea-island structure", and the pesticide has good compatibility with the rubber phase; the pesticide is aggregated into the island-phase structure of the thermoplastic vulcanizate in a dynamically vulcanized cross-linking manner, thereby forming a thermoplastic vulcanizate with the pesticide as the core and the island-phase material as the shell.

[0050] In the first aspect of the present invention, there is provided a thermoplastic vulcanizate, and its raw materials include the following components by weight: 8-40 parts of heat-resistant rubber, 60-90 parts of plastic, 1-6 parts of antifeedant, and 0.1-3 parts of vulcanizing agent.

[0051] In some examples, the heat-resistant rubber is one or more of ethylene-vinyl acetate rubber, silicone rubber, acrylate rubber, hydrogenated nitrile rubber, nitrile rubber, chlorinated polyethylene rubber, and ethylene propylene diene monomer rubber. Further, the heat-resistant rubber is ethylene-vinyl acetate rubber, acrylate rubber, and hydrogenated nitrile rubber. Specifically, the vinyl acetate content in the ethylene-vinyl acetate rubber is 18%-80%; the higher the VA content, the greater the polar interaction between molecular chains, and the better its heat resistance. The double bond content of the hydrogenated nitrile rubber is 1%-5%, and the acrylonitrile content is 30%-70%; a higher acrylonitrile content will increase the polar interaction between molecular chains and enhance the interaction between molecular chains, significantly improving its thermal stability; the double bond content of the hydrogenated nitrile rubber will affect its thermal stability, and a higher double bond content will reduce its thermal stability. Therefore, controlling the double bond content and acrylonitrile content within the above ranges is beneficial to ensuring its good thermal stability. In the same region, there are more silicone rubber island phases in SEM than the chlorine element aggregation regions in EDS, indicating that part of the IMI is encapsulated, while part of the IMI diffuses into the high-density polyethylene matrix.

[0052] In some examples, the plastic is one or more of high-density polyethylene, low-density polyethylene, polypropylene, polyvinylidene fluoride, and polyvinyl chloride.

[0053] In some examples, the antifeedant is one or more of imidacloprid, bifenthrin, abamectin, thiamethoxam, cypermethrin, chlorpyrifos, and fipronil. The antifeedant has good compatibility with the rubber, which can improve the stability of the prepared thermoplastic vulcanizate.

[0054] In some of these examples, the vulcanizing agent is one or more of dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, sulfur, silane coupling agent, trithiocyanuric acid, 2,4-dichlorobenzoyl peroxide, and tert-butyl perbenzoate. Further, the vulcanizing agents are dicumyl peroxide and tert-butyl perbenzoate.

[0055] In some of these examples, the raw materials of the thermoplastic vulcanizate further include at least one of an antioxidant and an anti-aging agent.

[0056] In some of these examples, the raw materials of the thermoplastic vulcanizate by weight parts include the following components: 8-40 parts of heat-resistant rubber, 60-90 parts of plastic, 1-6 parts of ant-ants agent, 0.1-3 parts of vulcanizing agent, 0.1-0.5 parts of antioxidant, and 0.5-1 part of anti-aging agent.

[0057] In some of these examples, the antioxidant is at least one of antioxidant 1010, antioxidant 264, antioxidant 168, and antioxidant 1067.

[0058] In some of these examples, the anti-aging agent is at least one of anti-aging agent 4010NA, anti-aging agent ODA, and antioxidant 264. Specifically, anti-aging agent 4010NA is N-isopropyl-N'-phenyl-p-phenylenediamine, anti-aging agent ODA is octylated diphenylamine, and antioxidant 264 is 2,6-di-tert-butyl-4-methylphenol, and those skilled in the art can make a choice according to the actual situation.

[0059] It can be understood that the raw materials of the thermoplastic vulcanizate may further contain other additives added according to needs in the industry, such as plasticizers, calcium carbonate, montmorillonite, masterbatch, etc., and their dosages are conventional dosages, and those skilled in the art can add them according to the actual situation. Optionally, the plasticizer is at least one of dioctyl sebacate, triphenyl phosphate, epoxidized soybean oil, diisononyl phthalate, dioctyl phthalate, diisononyl phthalate, paraffinic oil, and naphthenic oil.

[0060] In the second aspect of the present invention, there is provided a method for preparing a thermoplastic vulcanizate as described above, including the following steps:

[0061] Mix the heat-resistant rubber, ant-ants agent, and vulcanizing agent to prepare a premix;

[0062] Blend the premix and the plastic to prepare a rubber-plastic mixture;

[0063] Perform dynamic vulcanization processing on the rubber-plastic mixture.

[0064] In some of these examples, a method for preparing a thermoplastic vulcanizate as described above includes the following steps:

[0065] Mix the heat-resistant rubber, ant repellent, and vulcanizing agent to prepare a premix;

[0066] Blend the premix, plastic, antioxidant, and anti-aging agent to prepare a rubber-plastic mixture;

[0067] Carry out dynamic vulcanization processing on the rubber-plastic mixture.

[0068] In some examples, a method for preparing a thermoplastic vulcanizate as described above includes the following steps:

[0069] (1) Premixing of rubber and ant repellent: Mix rubber, ant repellent, and vulcanizing agent evenly at a lower temperature (below the rubber crosslinking temperature) using a Banbury mixer, and then cool to room temperature;

[0070] (2) Mix the premix in (1) with the plastic, plasticizer, antioxidant, and anti-aging agent in the formula evenly at room temperature to obtain a rubber-plastic mixture;

[0071] (3) Dynamic vulcanization: Subject the mixed rubber-plastic mixture to shear vulcanization using a torque rheometer. The processing temperature is controlled at 160 - 230 °C, the processing speed is 30 - 90 rpm, and the processing time is 5 - 15 min.

[0072] In some examples, the conditions for dynamic vulcanization processing include: the temperature is 160 °C - 230 °C. It can be understood that the temperature for dynamic vulcanization processing includes but is not limited to 160 °C, 170 °C, 180 °C, 190 °C, 200 °C, 210 °C, 220 °C, 230 °C.

[0073] In some examples, the conditions for dynamic vulcanization processing include: the speed is 30 rpm - 90 rpm. It can be understood that the speed for dynamic vulcanization processing includes but is not limited to 30 rpm, 40 rpm, 50 rpm, 60 rpm, 70 rpm, 80 rpm, 90 rpm.

[0074] In some examples, the conditions for dynamic vulcanization processing include: the time is 5 min - 10 min. It can be understood that the time for dynamic vulcanization processing includes but is not limited to 5 min, 6 min, 7 min, 8 min, 9 min, 10 min.

[0075] In the third aspect of the present invention, there is provided an insect-proof and insecticidal chemical product, the preparation raw materials of which include the thermoplastic vulcanizate as described above.

[0076] In the fourth aspect of the present invention, there is provided a cable, including a cable body and the insect-proof and insecticidal chemical product as described above attached to the surface of the cable body.

[0077] The following is further described in conjunction with specific embodiments. The raw materials involved in the following specific embodiments, unless otherwise specified, can all be commercially available; the instruments used, unless otherwise specified, can all be commercially available; the processes involved, unless otherwise specified, are all routinely selected by those skilled in the art.

[0078] The following are specific embodiments.

[0079] Example 1

[0080] The basic composition and weight proportions of the raw materials selected in this embodiment are as follows: 16 weight parts of ethylene-vinyl acetate rubber (EVA) (the content of vinyl acetate (VA) in ethylene-vinyl acetate rubber is 26%), 80 weight parts of high-density polyethylene (HDPE), 4 weight parts of imidacloprid (IMI), 0.16 weight parts of diisopropyl peroxide, 0.5 weight parts of antioxidant 1010, and 1 weight part of antioxidant 4010NA.

[0081] The preparation process of drug-aggregated thermoplastic vulcanizate is as follows:

[0082] (1) Preliminary mixing of ethylene-vinyl acetate rubber, dicumyl peroxide and imidacloprid was performed in an internal mixer: the mixing temperature was 100° C., the mixing speed was 60 rpm, and the mixing time was 6 min;

[0083] (2) The premix in (1) is mixed uniformly with high-density polyethylene, antioxidant 1010 and antioxidant 4010NA at room temperature to obtain a rubber-plastic mixture;

[0084] (3) Dynamic vulcanization: The mixed rubber and plastic mixture is subjected to shear vulcanization by a torque rheometer. The processing temperature is 190°C, the processing speed is 60 rpm, and the processing time is 10 minutes.

[0085] The difference between Example 2 and Example 1 mainly lies in the difference in the raw material fractions: 8 parts by weight of ethylene-vinyl acetate rubber (EVA) (the content of vinyl acetate (VA) in ethylene-vinyl acetate rubber is 26%), 90 parts by weight of high-density polyethylene (HDPE), 2 parts by weight of imidacloprid (IMI), 0.08 parts by weight of diisopropylbenzene peroxide, 0.5 parts by weight of antioxidant 1010, and 1 part by weight of antioxidant 4010NA.

[0086] The difference between Example 3 and Example 1 is mainly the difference in the raw material fractions: 24 parts by weight of ethylene-vinyl acetate rubber (EVA) (the content of vinyl acetate (VA) in ethylene-vinyl acetate rubber is 26%), 70 parts by weight of high-density polyethylene (HDPE), 6 parts by weight of imidacloprid (IMI), 0.24 parts by weight of diisopropylbenzene peroxide, 0.5 parts by weight of antioxidant 1010, and 1 part by weight of antioxidant 4010NA.

[0087] Example 4

[0088] The basic composition and weight proportions of the raw materials selected in this embodiment are as follows: 16 weight parts of silicone rubber, 80 weight parts of high-density polyethylene (HDPE), 4 weight parts of imidacloprid (IMI), 0.8 weight parts of dicumyl peroxide, 0.5 weight parts of antioxidant 1010, and 1 weight part of antioxidant 4010NA.

[0089] The preparation process of drug-aggregated thermoplastic vulcanizate is as follows:

[0090] (1) Preliminary mixing of silicone rubber, dicumyl peroxide and imidacloprid was performed in an internal mixer: the mixing temperature was 100°C, the mixing speed was 60 rpm, and the mixing time was 6 min;

[0091] (2) The premix in (1) is mixed uniformly with high-density polyethylene, antioxidant 1010 and antioxidant 4010NA at room temperature to obtain a rubber-plastic mixture;

[0092] (3) Dynamic vulcanization: The mixed rubber and plastic mixture is subjected to shear vulcanization by a torque rheometer. The processing temperature is 190°C, the processing speed is 60 rpm, and the processing time is 10 minutes.

[0093] Example 5

[0094] The basic composition and weight proportions of the raw materials selected in this embodiment are as follows: 8 weight parts of silicone rubber, 90 weight parts of high-density polyethylene (HDPE), 2 weight parts of imidacloprid (IMI), 0.4 weight parts of dicumyl peroxide, 0.5 weight parts of antioxidant 1010, and 1 weight part of antioxidant 4010NA.

[0095] The preparation process of drug-aggregated thermoplastic vulcanizate is as follows:

[0096] (1) Preliminary mixing of silicone rubber, dicumyl peroxide and imidacloprid was performed in an internal mixer: the mixing temperature was 100°C, the mixing speed was 60 rpm, and the mixing time was 6 min;

[0097] (2) The premix in (1) is mixed uniformly with high-density polyethylene, antioxidant 1010 and antioxidant 4010NA at room temperature to obtain a rubber-plastic mixture;

[0098] (3)Dynamic vulcanization: The mixed rubber-plastic mixture is subjected to shear vulcanization through a torque rheometer. The processing temperature is 190 °C, the processing speed is 60 rpm, and the processing time is 10 min.

[0099] Example 6

[0100] The basic composition and weight parts of the raw materials selected in this example are as follows: acrylate rubber 16 parts by weight, high-density polyethylene (HDPE) 80 parts by weight, imidacloprid (IMI) 4 parts by weight, tert-butyl perbenzoate 0.48 parts by weight, antioxidant 1010 0.5 parts by weight, antioxidant 4010NA 1 part by weight.

[0101] The preparation process of the drug-aggregated thermoplastic vulcanizate is as follows:

[0102] (1)The acrylate rubber, tert-butyl perbenzoate, and imidacloprid are preliminarily mixed and premixed through a kneader: the mixing temperature is 100 °C, the mixing speed is 60 rpm, and the mixing time is 6 min;

[0103] (2)The premix in (1) is mixed evenly with high-density polyethylene, antioxidant 1010, and antioxidant 4010NA at room temperature to obtain a rubber-plastic mixture;

[0104] (3)Dynamic vulcanization: The mixed rubber-plastic mixture is subjected to shear vulcanization through a torque rheometer. The processing temperature is 190 °C, the processing speed is 60 rpm, and the processing time is 10 min.

[0105] Comparative Example 1

[0106] The basic composition and weight parts of the raw materials selected in this comparative example are as follows: high-density polyethylene (HDPE) 96 parts by weight, imidacloprid (IMI) 4 parts by weight, antioxidant 1010 0.5 parts by weight, antioxidant 4010NA 1 part by weight.

[0107] The preparation process is as follows:

[0108] Imidacloprid, high-density polyethylene, antioxidant 1010, and antioxidant 4010NA are directly mixed evenly in a torque rheometer under the processing conditions of 180 °C, 60 rpm, and 8 min to obtain an IMI / HDPE composite material.

[0109] Comparative Example 2

[0110] Comparative Example 2 is basically the same as Example 1, and the main difference is that: no vulcanizing agent is added in Comparative Example 2.

[0111] Comparative Example 3

[0112] Comparative Example 3 is basically the same as Example 1, and the main difference is that ethylene-vinyl acetate rubber is changed to silicone rubber (methyl vinyl silicone rubber), and high-density polyethylene is changed to polypropylene.

[0113] The thermoplastic vulcanizates prepared in the examples and comparative examples were subjected to performance tests:

[0114] (1) Microscopic morphology: In order to observe the microscopic morphology of the prepared drug-aggregated thermoplastic vulcanizate, the present invention used a field emission scanning electron microscope (SEM, Inspect-F, FEI, Finland) to observe the prepared drug-aggregated thermoplastic vulcanizate at an acceleration voltage of 5 kV.

[0115] (2) In order to prove that the thermal stability performance is improved after IMI is wrapped with EVA, the thermogravimetric curves of the original IMI drug and IMI / HDPE, IMI / EVA / HDPE were measured.

[0116] The test results are as Figure 1-6 shown.

[0117] As Figure 1 can be seen, the drug-aggregated thermoplastic vulcanizate prepared in Example 1 presents a sea-island structure, and the sizes of the dispersed rubber phases are mostly concentrated in the range of 2-10 μm, and its morphology presents an irregular ellipsoidal shape. HDPE, EVA, antioxidant 1010 and antiozonant 4010NA do not contain chlorine elements, while IMI contains a certain amount of chlorine elements; by performing elemental scanning on the entire cross-section of the material, it can be found that most of the chlorine elements in IMI are concentrated in the dispersed EVA rubber phase. The experimental results show that the dispersed EVA phase has preliminarily wrapped IMI.

[0118] As Figure 2 can be seen, the initial decomposition temperature of IMI is 240 °C. The thermogravimetric curves of IMI / EVA and IMI / EVA / HDPE composites both show three steps. The first thermogravimetric step of them is attributed to the decomposition of IMI in the composite material; the second and third thermogravimetric steps in the IMI / EVA composite are attributed to the decomposition of EVA in the composite material; the second and third thermogravimetric steps in the IMI / EVA / HDPE composite are attributed to the decomposition of EVA and HDPE; while the initial decomposition temperatures of IMI / EVA and IMI / EVA / HDPE are both 258 °C. The increase in the initial thermal decomposition temperature benefits from the wrapping of EVA on the outside, which reduces the transfer of part of the heat.

[0119] Figure 3It is the SEM image of IMI / silicone rubber / high-density polyethylene prepared in Example 4 and the EDS image of chlorine element in the composite material. From the microscopic schematic diagram of the composite material, it can be seen that the microscopic cross-section structure of the prepared material is a sea-island structure, and the particle size of the island-phase silicone rubber is distributed between 10 μm and 20 μm. From the EDS map of chlorine element, it can be seen that IMI shows an aggregated distribution. However, as a whole, it can be seen that in the same area, the silicone rubber island phase in the SEM is more than the chlorine element aggregation area in the EDS, indicating that part of IMI is encapsulated, while part of IMI diffuses into the high-density polyethylene matrix.

[0120] Figure 4 It is the thermogravimetric curve of IMI / silicone rubber / high-density polyethylene prepared in Example 4. The initial thermal decomposition temperature of IMI is 240 °C. The thermogravimetric curve of IMI / silicone rubber / high-density polyethylene shows three steps. The first step corresponds to the thermal decomposition of IMI. It can be clearly seen that the decomposition temperature of IMI in the composite material is significantly higher than the initial decomposition temperature of pure drug IMI.

[0121] Figure 5 It is the SEM image and EDS map of the composite material prepared in Comparative Example 1. It can be seen that when the traditional pesticide is directly added to the resin, the chlorine element shows a uniform distribution, indicating that IMI is uniformly dispersed in HDPE and is easily affected by the surrounding environment.

[0122] Figure 6 It is the SEM image and EDS map of the composite material prepared in Comparative Example 2. It can be seen that in the case of not adding a cross-linking agent, the chlorine element shows a uniform distribution, indicating that IMI does not aggregate into the island-phase EVA and is uniformly dispersed in HDPE.

[0123] 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 embodiments are described. However, as long as the combinations of these technical features do not conflict, they should be considered to be within the scope described in this specification.

[0124] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims, and the specification can be used to explain the content of the claims.

Claims

1. A thermoplastic vulcanizate, characterized in that: The raw materials include the following components by weight: 8-40 parts of heat-resistant rubber, 60-90 parts of plastic, 1-6 parts of anti-termite agent and 0.1-3 parts of vulcanizing agent.

2. The thermoplastic vulcanizate according to claim 1, characterized in that The heat-resistant rubber is one or more of ethylene-vinyl acetate rubber, silicone rubber, acrylic rubber, hydrogenated nitrile rubber, nitrile rubber, chlorinated polyethylene rubber and EPDM rubber.

3. The thermoplastic vulcanizate according to claim 1, characterized in that The plastic is one or more of high-density polyethylene, low-density polyethylene, polypropylene, polyvinylidene fluoride and polyvinyl chloride.

4. The thermoplastic vulcanizate according to claim 1, characterized in that The anti-ant agent is one or more of imidacloprid, bifenthrin, avermectin, thiamethoxam, cypermethrin, chlorpyrifos and fipronil; and / or The vulcanizing agent is one or more of dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, sulfur, silane coupling agent, thiocyanate, 2,4-dichlorobenzoyl peroxide and tert-butyl perbenzoate.

5. The thermoplastic vulcanizate according to any one of claims 1 to 4, characterized in that: The raw materials of the thermoplastic vulcanizate also include at least one of an antioxidant and an anti-aging agent; Optionally, the raw materials of the thermoplastic vulcanizate include the following components by weight: 8-40 parts of heat-resistant rubber, 60-90 parts of plastic, 1-6 parts of anti-termite agent, 0.1-3 parts of vulcanizer, 0.1-0.5 parts of antioxidant, and 0.5-1 parts of antioxidant.

6. The thermoplastic vulcanizate according to claim 5, characterized in that The antioxidant is at least one of antioxidant 1010, antioxidant 264, antioxidant 168 and antioxidant 1067; and / or The antioxidant is at least one of antioxidant 4010NA, antioxidant ODA and antioxidant 264.

7. A method for preparing a thermoplastic vulcanizate according to any one of claims 1 to 6, characterized in that: The following steps are involved: Mixing the heat-resistant rubber, the anti-termite agent and the vulcanizing agent to prepare a premix; blending the premix with plastic to prepare a rubber-plastic mixture; The rubber-plastic mixture is subjected to dynamic vulcanization processing.

8. The method for preparing a thermoplastic vulcanizate according to claim 7, characterized in that: The step of dynamic vulcanization processing satisfies at least one of the following conditions: (1) Temperature is 160℃-230℃; (2) The speed is 30 rpm-90 rpm; (3) The time is 5 minutes to 10 minutes.

9. An insect repellent and insecticide chemical product, characterized in that: The raw materials for its preparation include the thermoplastic vulcanizate described in any one of claims 1 to 5.

10. A cable, characterized in that: The invention comprises a cable body, and the insect repellent and insecticide chemical product as claimed in claim 9 attached to the surface of the cable body.

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