Preparation method of self-healing glue capable of being directly and efficiently coated and self-healing glue

Abstract

The application provides a preparation method of directly and efficiently coated self-healing rubber and self-healing rubber. The method comprises the following steps: uniformly mixing raw materials including raw rubber, carbon black, white carbon black, antioxidant, tackifying resin, plasticizer, crosslinking agent and crosslinking aid to obtain a mixed masterbatch; feeding the mixed masterbatch into a parallel co-rotating twin-screw extruder, adding polyisobutylene through multiple liquid injection ports on the cylinder for multiple times, and extruding into a single-screw extruder; the residence time in the single-screw extruder is 1 min to 2.5 min, and the temperature is 135 DEG C to 175 DEG C, and the directly and efficiently coated self-healing rubber is obtained after extrusion. After the pre-crosslinking reaction, the coating efficiency is greatly improved, the coating equipment and process matched with the self-healing rubber production line are reduced by half, the equipment investment is greatly reduced, the energy consumption is reduced, and obvious economic and social benefits are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rubber, further relates to a preparation method of self-healing rubber capable of being directly and efficiently coated and self-healing rubber. BACKGROUND

[0002] The preparation of self-healing tire coating includes two key procedures: preparation of high-performance self-healing rubber and uniform coating of self-healing rubber on the inner wall of tire.

[0003] The technical core of self-healing rubber is a layer of self-healing rubber with memory function uniformly coated on the inner wall of tire, which not only has good stress-responsive viscoelasticity, air tightness, tensile strength and aging resistance, but also maintains good viscosity and adhesion to the inner layer of tire under high and low temperature conditions (-40℃-120℃). However, the current self-healing tires generally have problems such as diffusion of the adhered self-healing rubber to the periphery (viscosity problem) and local self-healing rubber peeling off from the surface of tire (adhesion problem) during use.

[0004] Generally, the prepared self-healing rubber needs to be heated again and then pumped through a nozzle to be coated on the inner wall of tire. Since a certain chemical cross-linking reaction of the material needs to occur during the coating process, and the processing performance of the material cannot be prematurely scorching to cause nozzle blockage, the entire coating process takes 4-5 minutes. Although the current coating equipment generally uses a robot to reduce the work intensity, the efficiency is still low, and often a self-healing rubber production line needs to be equipped with 6-8 coating equipment and workstations, which greatly increases the equipment investment of the coating process. Moreover, in the traditional preparation process, the material undergoes a process of cooling and then re-heating, which also increases the additional energy consumption.

[0005] In view of the above technical problems, it is necessary to study a preparation method of self-healing rubber. SUMMARY

[0006] In order to solve the technical problems existing in the prior art, the present application provides a preparation method of self-healing rubber capable of being directly and efficiently coated and self-healing rubber.

[0007] The purpose of the present application is to overcome the deficiencies of the existing self-healing rubber preparation technology, especially the low efficiency of the existing self-healing rubber product in the coating process, and to provide a preparation method of self-healing rubber capable of being directly and efficiently coated.

[0008] One of the purposes of the present application is to provide a preparation method of self-healing rubber capable of being directly and efficiently coated, which comprises:

[0009] (1) mixing raw materials including raw rubber, carbon black, white carbon black, antioxidant, tackifying resin, plasticizer, crosslinking agent, crosslinking aid to obtain a mixed masterbatch;

[0010] (2) feeding the mixed masterbatch into a parallel co-rotating twin-screw extruder, adding polyisobutylene in multiple times through multiple liquid injection ports on the barrel, and extruding into a single-screw extruder;

[0011] (3) the residence time in the single-screw extruder is 1 min to 2.5 min, and the temperature is 135℃ to 175℃, and the extruded product is the directly high-efficiency coating self-healing rubber.

[0012] In a preferred embodiment of the present application,

[0013] The raw rubber is at least one of butyl rubber, natural rubber, isoprene rubber, and thermoplastic elastomer;

[0014] The carbon black is a commonly used commercial carbon black in the art, and is preferably at least one of N330, N234 or N550;

[0015] The white carbon black is a commonly used commercial white carbon black in the art, and is preferably at least one of precipitated white carbon black or fumed white carbon black;

[0016] The antioxidant is a commonly used antioxidant in the art, and is preferably at least one of antioxidant 4020, antioxidant RD, or antioxidant 2246;

[0017] The tackifying resin is at least one of C5 resin, C9 resin, rosin, and terpene resin;

[0018] The plasticizer is a commonly used plasticizer in the art, and is preferably at least one of paraffin oil, naphthenic oil, or environmentally friendly aromatic hydrocarbon oil;

[0019] The crosslinking agent is at least one of sulfur or organic peroxide;

[0020] The crosslinking aid is a commonly used crosslinking aid in the art, and is preferably at least one of zinc oxide, accelerator DM, accelerator CZ, or accelerator NS.

[0021] In a preferred embodiment of the present application,

[0022] Step (1),

[0023] mixing the masterbatch in an internal mixer; and / or,

[0024] The mixed masterbatch has a Mooney viscosity of 15 to 50, preferably 20 to 35; and / or,

[0025] The mass of the tackifying resin accounts for 8% to 20% of the total mass of the mixed masterbatch.

[0026] In one preferred embodiment of the present application,

[0027] Step (2),

[0028] The number average molecular weight of the polyisobutylene is 600-2500, preferably 800-1200; and / or,

[0029] The mass ratio of the mixed masterbatch to the polyisobutylene is 1:(1.2-2.8); preferably 1:(1.8-2.6).

[0030] In one preferred embodiment of the present application,

[0031] The parallel twin-screw extruder comprises a feeding and conveying premixing section, a mixing and compounding section, a compression and exhaust section, and an exhaust and discharging section; and / or,

[0032] The addition temperature of the polyisobutylene is 55-100°C, preferably 60-90°C; and / or,

[0033] The temperature of the feeding and conveying premixing section is 50-95°C, preferably 60-70°C; and / or,

[0034] The temperature of the mixing and compounding section is 55-85°C, preferably 75-85°C; and / or,

[0035] The temperature of the compression and exhaust section is 80-120°C, preferably 90-100°C; and / or,

[0036] The residence time in the parallel twin-screw extruder is 1-4 minutes, preferably 3-4 minutes; and / or,

[0037] The rubber compound is fed from the parallel twin-screw extruder into the single-screw extruder by means of butt joint or pumping.

[0038] In one preferred embodiment of the present application,

[0039] The feeding and conveying premixing section and the mixing and compounding section of the parallel twin-screw extruder are provided with 3-6 liquid injection ports, preferably 4-6 liquid injection ports; preferably, the first and second injection ports are in the feeding and conveying premixing section, and the two injection ports are spaced apart by at least one barrel section; the third injection port is at the end of the feeding and conveying premixing section or in the mixing and compounding section, and the third injection port is spaced apart from the second injection port by at least two barrel sections; further preferably, the fourth, fifth or sixth injection port is provided in the mixing and compounding section.

[0040] In one preferred embodiment of the present application,

[0041] The number of barrels of the feeding and conveying premixing section, the mixing and compounding section, the compression and exhaust section and the exhaust and discharging section of the parallel co-rotating twin-screw extruder is 4-10, 3-8, 1-2 and 1, respectively, and preferably 6-8, 3-5, 2 and 1, respectively.

[0042] In a preferred embodiment of the present application,

[0043] The screw of the parallel co-rotating twin-screw extruder is composed of screw elements on a mandrel;

[0044] The screw elements of the feeding and conveying premixing section are at least two of conveying elements, shearing elements and intermeshing blocks;

[0045] The elements of the mixing and compounding section are at least two of conveying elements, shearing elements, intermeshing blocks and toothed discs;

[0046] The elements of the compression and exhaust section are at least one of conveying elements and shearing elements.

[0047] In a preferred embodiment of the present application,

[0048] When the polyisobutylene is added through three liquid injection ports, the mass ratio of the addition in the order of sequence is 1:(1.3-3):(1.5-10);

[0049] When the polyisobutylene is added through four liquid injection ports, the mass ratio of the addition in the order of sequence is 1:(1.3-2.5):(1.5-6):(2-10);

[0050] When the polyisobutylene is added through five liquid injection ports, the mass ratio of the addition in the order of sequence is 1:(1.1-2):(1.5-5):(2-8):(2.5-10);

[0051] When the polyisobutylene is added through six liquid injection ports, the mass ratio of the addition in the order of sequence is 1:(1-2):(1.35-4):(1.5-6):(2-8):(2.5-10).

[0052] The second object of the present application is to provide a self-healing glue prepared by the above method, which can be directly and efficiently coated.

[0053] The present application can be implemented by the following technical solutions:

[0054] The raw rubber, carbon black, white carbon black, antioxidant, tackifying resin, plasticizer, crosslinking agent and crosslinking aid are mixed uniformly in an internal mixer to prepare a mixing masterbatch with a Mooney viscosity of 15-35. 100 parts by weight of the mixing masterbatch is added to a single screw extruder with a forced pressure device. The compression ratio of the single screw extruder is controlled to be 1.05-2.5 and the temperature is controlled to be 50-100℃. The end of the single screw extruder is connected to a rubber metering and conveying device. The preheated and preplasticized mixing masterbatch is quantitatively connected to a parallel co-rotating twin screw extruder. Three or four or five or six liquid injection ports are opened in the feeding and conveying premixing section of the twin screw extruder. A total of 120-280 parts by weight of polyisobutylene PIB with a number average molecular weight of 600-2500 is added through a liquid metering feeding device. The addition temperature of the polyisobutylene is controlled to be 55-100℃. The barrel temperature of the feeding section is controlled to be 50-95℃. Then the mixture is conveyed through the mixing and kneading section (temperature 55-85℃) and the compression and venting section (temperature 80-120℃) of the twin screw extruder. The residence time is 1-4 minutes. Then the mixture is conveyed through the exhaust and discharge section and the die head of the extruder. The mixture is connected or pumped into a single screw extruder. The temperature of the single screw extruder is controlled to be 135-175℃. The residence time is 1-2.5 minutes. The mixture is extruded from the die head of the single screw extruder to obtain a self-healing rubber which can be directly and efficiently coated.

[0055] The raw rubber is preferably a mixture of one or more of butyl rubber, natural rubber, isoprene rubber and thermoplastic elastomer.

[0056] The tackifying resin is preferably a mixture of one or more of C5 resin, C9 resin, rosin and terpene resin.

[0057] The crosslinking agent is preferably a mixture of one or both of sulfur crosslinking agent and peroxide crosslinking agent.

[0058] The number of barrels of the feeding and conveying premixing section, the mixing and kneading section, the compression and venting section and the exhaust and discharge section of the co-rotating twin screw extruder is preferably 4-10, 3-8, 1-2 and 1, respectively.

[0059] The screw of the co-rotating twin screw extruder is composed of screw elements on a mandrel. The screw elements of the feeding and conveying premixing section are preferably two or three of conveying element, shearing element and intermeshing block. The screw elements of the mixing and kneading section are preferably two, three or four of conveying element, shearing element, intermeshing block and toothed disc. The screw elements of the compression and venting section are preferably one or two of conveying element and shearing element.

[0060] The ratio of the polyisobutylene added through three liquid injection ports is preferably 1:1.3-3:1.5-10; the ratio of the polyisobutylene added through four liquid injection ports is preferably 1:1.3-2.5:1.5-6:2-10, the ratio of the polyisobutylene added through five liquid injection ports is preferably 1:1.1-2:1.5-5:2-8:2.5-10; the ratio of the polyisobutylene added through six liquid injection ports is preferably 1:1-2:1.35-4:1.5-6:2-8:2.5-10.

[0061] Compared with the prior art, the beneficial effects of the present application are:

[0062] By comparing and analyzing the current self-healing glue products and the disclosed technical means, the key problems of the self-healing glue products are: high viscosity, poor flowability, poor high temperature resistance, easy to cause glue softening and glue strength to deteriorate after temperature rise, and reduce the adhesion of the glue; in addition, the adhesion of the self-healing glue is poor, and the tire will produce glue falling, turning, displacement and glue accumulation during driving. In order to solve the problems existing in the prior art, the present application first adds a large amount of liquid polyisobutylene PIB with good air tightness, good flowability and good compatibility with the rubber matrix in the formula system design, to ensure that the self-healing glue still has good flowability and sealing property at low temperature; a crosslinking system is added in the formula, so that the self-healing glue is micro-crosslinked during spraying, and a certain degree of network structure is formed, so that the self-healing glue will not flow at high temperature; in addition, tackifying resin is added in the formula system to improve the adhesion property, and carbon black / white carbon black reinforcing agent and antioxidant are added to ensure the tensile strength and anti-aging property of the self-healing glue. The attached self-healing glue spreads to the periphery, the viscosity problem; the local self-healing glue falls off from the surface of the tire, the adhesion problem.

[0063] In addition, the self-healing glue must be evenly coated on the inner side of the tire, and the self-healing glue product has no obvious particles and no bubbles, which is the premise of realizing the uniform coating of the self-healing glue, that is, to ensure that the self-healing glue is a homogeneous system. Because more than 120 parts of PIB liquid are designed to be added in the formula system, the traditional rubber processing equipment such as the internal mixer and the open mill is difficult to mix and process the large amount of liquid and solid masterbatch. For example, if a large amount of liquid is added in the internal mixer, it will be difficult to process due to the slip phenomenon, and even the material cannot be discharged from the internal mixer. The present application adopts the linkage mixing equipment of single screw extruder and twin screw extruder for the formula system, and matches the appropriate process. First, on the basis of computer simulation calculation, the solid mixing masterbatch is formed by the design combination of screw elements to form multiple changes in flow direction and flow rate, and a twin screw extruder suitable for rubber mixing extrusion is designed, and through the control of screw configuration and combination, temperature control of each section, temperature control of solid masterbatch and liquid PIB, and control of the amount of liquid PIB added in the process of the advancing of the mixing masterbatch, the uniform mixing of the high-ratio liquid and solid mixing masterbatch is finally realized; through the viscosity change research of the solid mixing masterbatch under different temperature and time conditions, the solid mixing masterbatch is preheated to the appropriate viscosity in the first single screw extruder; through the research on the influence of different PIB liquid addition amount on the viscosity of the mixing masterbatch with different viscosity and temperature, the uniform dispersion of PIB liquid in the continuous phase of the mixing masterbatch in the mixing process, and the controllable technology research on the viscosity evolution and uniformity distribution in the extrusion process, the screw element combination of the different liquid injection sections of the pre-mixing section of the twin screw extruder is simulated, so that the uniform mixing and dispersion of a large amount of liquid in the rubber continuous phase is realized in the process of the solid mixing masterbatch advancing, the viscosity gradient change and compatibility are gradually realized, and the existence of solid particles is eliminated; at the same time, in the mixing section of the twin screw extruder, the distributed mixing of the material is further realized to form a homogeneous system; in the exhaust extrusion section, on the one hand, the material is discharged by using the mixing of the screw while reducing the screw groove depth; on the other hand, in the material discharge section, the screw thread element lead and groove depth are increased, and the material internal gas is further extracted from the outside by vacuumizing.

[0064] The present application comprehensively considers the material performance and process correlation of the self-healing glue preparation process and its coating process. In the self-healing glue preparation process, according to the material characteristics and the crosslinking characteristics of the crosslinking agent, a certain pre-crosslinking reaction of the material is continuously carried out after the self-healing glue is uniformly mixed. The pre-crosslinking reaction time is controlled within the scorch time range of the self-healing glue, which on the one hand ensures the processing performance of the material and avoids the nozzle blockage caused by premature scorching to affect the coating; on the other hand, it greatly reduces the chemical crosslinking reaction time required in the coating process, improves the coating efficiency, and reduces the entire coating time by 2-3 minutes, and the efficiency is more than doubled.

[0065] In addition, the whole preparation process of the present application is simple, the existing rubber mixing equipment is still used in the preparation stage of the mixed master batch, no new equipment investment is needed, the series screw extruder set of the single screw feeding pretreatment extruder and the double screw mixing exhaust extruder is used in the mixed and mixed stage of the mixed master batch and the liquid, a single screw extruder is continuously connected in series in the pre-crosslinking chemical reaction stage, the whole preparation process of the self-healing glue is continuous, short in time, high in efficiency, automatic in process, labor-saving, stable and controllable in production process. Finally, the self-healing glue product obtained by the present application is not only mixed uniformly, free of particles and bubbles, but also has good fluidity and adhesion strength to the tire under low temperature conditions, and can still maintain good aging resistance and tensile strength under high temperature conditions without softening and flowing; in addition, after the pre-crosslinking reaction, the coating efficiency is greatly improved, the coating equipment and process matched with the self-healing glue production line are reduced by half, the equipment investment is greatly reduced, the energy consumption is reduced, and obvious economic and social benefits are obtained. DETAILED DESCRIPTION

[0066] The present application will be described in detail below in combination with specific examples. It is necessary to point out here that the following examples are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Some non-essential improvements and adjustments of the present application made by those skilled in the art according to the content of the present application still belong to the protection scope of the present application.

[0067] The raw materials used in the examples are all conventional commercially available raw materials.

[0068] The parts in the examples all refer to parts by weight.

[0069] Example 1

[0070] The natural rubber, isoprene rubber, carbon black N330, white carbon black, antioxidant 4020, C5 tackifying resin (10% of the total mass of the mixed master batch), plasticizer paraffin oil, sulfur crosslinking agent and crosslinking aid, etc. are uniformly mixed in an internal mixer to prepare a mixed master batch with a Mooney viscosity of 22.

[0071] The 100 parts by weight of the mixed masterbatch is added into a single screw extruder with forced compression device, the diameter of the single screw extruder is 120 mm, the length-diameter ratio is 8:1, the compression ratio of the single screw extruder is 2.5, the temperature is 100℃, the single screw extruder is connected with the rubber metering conveying device at the end of the single screw extruder, the preheated and preplasticized mixed masterbatch is quantitatively connected into a parallel co-rotating twin screw extruder (the diameter is 90 mm, the length-diameter ratio is 64:1, 16 sections of the barrel), the feeding conveying and premixing section is 8 sections, the screw elements include conveying elements, shearing elements and meshing blocks; the mixing and compounding section is 5 sections, the elements are conveying elements, meshing blocks and toothed discs, the compression and exhaust section is 2 sections, the elements adopt shearing compression elements, the number of the barrel of the exhaust and discharge section is 1 section, the barrel of the twin screw extruder is provided with six liquid inlets, the first and second inlets are in the feeding conveying and premixing section, the two inlets are spaced by 1 section of the barrel; the third inlet is at the end of the feeding conveying and premixing section, the third inlet is spaced by 2 sections of the barrel from the second inlet; the fourth, fifth and sixth inlets are arranged in the mixing and compounding section, 260 parts by weight of polyisobutylene PIB with a number average molecular weight of 1200 is added through the liquid metering feeding device, the proportion of the six liquid inlets is 1:1.25:2:4:6:8, the adding temperature of the polyisobutylene at the first three inlets is 65℃, the adding temperature of the polyisobutylene at the fourth and fifth inlets is 75℃, the adding temperature of the polyisobutylene at the sixth inlet is 85℃, the barrel temperature of the feeding section is 60℃, then the product passes through the mixing and compounding section (the temperature is 80℃) and the compression and exhaust section (the temperature is 90℃) of the twin screw extruder, stays for 4 minutes, and is connected into a single screw extruder (the diameter is 150 mm, the length-diameter ratio is 24:1) at the head of the twin screw extruder, the temperature of the single screw extruder is controlled at 150℃, stays for 2 minutes, and is extruded from the head of the single screw extruder to obtain the sealant for high-efficiency coating.

[0072] The obtained sealant product has no particles, no obvious solid particles are observed under 30 times magnification of a microscope, the product surface has no obvious bubbles after standing for 24 hours, the adhesion strength at -40℃ is decreased by 4.5% compared with the adhesion strength at 20℃, the adhesion strength retention rate is good; the viscosity of the product at 150℃ is decreased by 2.5% compared with the viscosity at 20℃, the viscosity retention rate is good, and no softening and flowing phenomenon occurs. In the subsequent spraying process, spraying is carried out at 135℃, the coating time is 2.5 minutes, the sealant can be uniformly coated on the inner side of the tire, and the corresponding crosslinking chemical reaction is completed, so that the sealant reaches a suitable crosslinking degree.

[0073] Example 2

[0074] Butyl rubber, thermoplastic elastomer, carbon black N330, white carbon black, antioxidant 4020, C9 tackifying resin (20% of the total mass of the mixing masterbatch), plasticizer paraffin oil, peroxide crosslinking agent and crosslinking aid were mixed uniformly in an internal mixer to prepare a mixing masterbatch with a Mooney viscosity of 35. 100 parts by weight of the mixing masterbatch were added to a single screw extruder with a forced pressure device, with a diameter of 120 mm and a length-diameter ratio of 8:1. The compression ratio of the single screw extruder was 1.2 and the temperature was 80°C. The end of the single screw extruder was connected to a rubber metering conveyor, and the preheated and preplasticized mixing masterbatch was quantitatively connected to a parallel co-rotating twin screw extruder (diameter 75 mm, length-diameter ratio 48:1, 12 sections of barrel). The feeding and conveying pre-mixing section was 6 sections, and the screw elements included conveying elements, shearing elements and meshing blocks. The mixing and mixing section was 3 sections, and the elements were conveying elements, meshing blocks and toothed discs. The compression and exhaust section was 2 sections, and the elements were shearing and compression elements. The number of barrels in the exhaust and discharge section was 1 section. The barrel of the feeding and conveying pre-mixing section had 3 liquid inlets. The first and second inlets were in the feeding and conveying pre-mixing section, and the two inlets were spaced 1 section of the barrel apart. The third inlet was at the end of the feeding and conveying pre-mixing section, and the third inlet was spaced 2 sections of the barrel apart from the second inlet. A total of 180 parts by weight of polyisobutylene PIB with a number average molecular weight of 800 was added through a liquid metering feeder. The ratio of the 3 liquid inlets was 1:2:8. The addition temperature of the polyisobutylene at the first 2 inlets was 60°C, and the addition temperature of the polyisobutylene at the third inlet was 70°C. The barrel temperature of the feeding section was 65°C. Then the mixture passed through the mixing and mixing section of the twin screw extruder (temperature 85°C), the compression and exhaust section (temperature 100°C) and the exhaust section and the extruder head, with a residence time of 3 minutes. The mixture was then sent to a single screw extruder (diameter 150 mm, length-diameter ratio 24:1) through a pipeline from a melt pump. The temperature of the single screw extruder was controlled at 170°C, and the residence time was 2.5 minutes. The mixture was then extruded from the head of the single screw extruder to obtain a sealant for high efficiency coating.

[0075] The obtained sealant product had no particles, and no obvious solid particles were observed under a microscope at 30 times magnification. The product surface had no obvious bubbles after 24 hours of storage. The adhesion strength at -40°C was 1.5% lower than that at 20°C, and the adhesion strength retention was good. At 150°C, the viscosity of the product was 5% lower than that at 20°C, and the viscosity retention was good, without softening and flowing phenomenon. In the subsequent spraying process, spraying at 155°C for 2 minutes can uniformly coat the inside of the tire and complete the corresponding crosslinking chemical reaction, so that the self-sealing adhesive reaches the appropriate crosslinking degree.

Claims

1. A method for preparing a directly and efficiently coat self-healing glue, characterized in that The method comprises: (1) uniformly mixing raw materials including raw rubber, carbon black, white carbon black, antioxidant, tackifying resin, plasticizer, crosslinking agent, crosslinking aid to obtain a mixed masterbatch; (2) adding the mixed masterbatch into a single screw extruder with forced pressing device, the compression ratio of the single screw extruder is 1.05-2.5, the temperature is 50-100℃, the end of the single screw extruder is connected with a rubber metering conveying device, the preheated and preplasticized mixed masterbatch is quantitatively connected into a parallel co-rotating twin screw extruder, polyisobutylene is added through multiple liquid injection ports on the cylinder in multiple times, and then extruded into a single screw extruder B; (3) the residence time in the single screw extruder B is 1 min-2.5 min, the temperature is 135℃-175℃, and the extruded product is the directly high-efficiency coating self-healing rubber; In step (1), the raw rubber is at least one of butyl rubber, natural rubber, isoprene rubber and thermoplastic elastomer; the tackifying resin is at least one of C5 resin, C9 resin, rosin and terpene resin; the mixed masterbatch has a Mooney viscosity of 15-50; and the mass of the tackifying resin accounts for 8-20% of the total mass of the mixed masterbatch; In step (2), The parallel co-rotating twin screw extruder comprises a feeding and conveying premixing section, a mixing and compounding section, a compression and exhaust section and an exhaust and discharging section; The number of cylinder sections of the feeding and conveying premixing section, the mixing and compounding section, the compression and exhaust section and the exhaust and discharging section of the parallel co-rotating twin screw extruder is 4-10, 3-8, 1-2 and 1 respectively; The feeding and conveying premixing section and the mixing and compounding section of the parallel co-rotating twin screw extruder are provided with 3-6 liquid injection ports; the first and second injection ports are in the feeding and conveying premixing section, the two injection ports are spaced apart by at least one cylinder section; the third injection port is at the end of the feeding and conveying premixing section, the third injection port is spaced apart from the second injection port by at least two cylinder sections; when the fourth to sixth liquid injection ports are provided, the fourth, fifth or sixth injection port is arranged in the mixing and compounding section; The number average molecular weight of the polyisobutylene is 600-2500; the mass ratio of the mixed masterbatch to the polyisobutylene is 1:(1.2-2.8); When the polyisobutylene is added through three liquid injection ports, the mass ratio of the first to third injection ports in the order of addition is 1:(1.3-3): (1.5-10); When the polyisobutylene is added through four liquid injection ports, the mass ratio of the first to fourth injection ports in the order of addition is 1:(1.3-2.5):(1.5-6):(2-10); When the polyisobutylene is added through five liquid injection ports, the mass ratio of the first to fifth injection ports in the order of addition is 1:(1.1-2):(1.5-5):(2-8):(2.5-10); When the polyisobutylene is added through six liquid injection ports, the mass ratio of the first to sixth injection ports in the order of addition is 1:(1-2):(1.35-4):(1.5-6):(2-8):(2.5-10); The addition temperature of the polyisobutylene is 55℃-100℃; The temperature of the feeding and conveying premixing section is 50℃-95℃; The temperature of the mixing and compounding section is 55℃-85℃; The temperature of the compression and exhaust section is 80℃-120℃.

2. The preparation method according to claim 1, wherein: the white carbon black is at least one of precipitated white carbon black or fumed white carbon black; and / or, the plasticizer is at least one of paraffin oil, naphthenic oil, and environmentally friendly aromatic hydrocarbon oil; and / or, the crosslinking agent is at least one of sulfur or organic peroxide; and / or, the crosslinking co-agent is at least one of zinc oxide, accelerator DM, accelerator CZ, or accelerator NS.

3. The preparation method according to claim 1, wherein: step (1) is mixing the masterbatch in an internal mixer.

4. The preparation method according to claim 1, wherein: the mixed masterbatch has a Mooney viscosity of 20-35.

5. The preparation method according to claim 1, wherein: step (2) is mixing the masterbatch and polyisobutylene in a parallel twin-screw extruder.

6. The preparation method according to claim 1, wherein: step (2) is mixing the masterbatch and polyisobutylene in a parallel twin-screw extruder.

7. The preparation method according to claim 6, wherein: the polyisobutylene is added at a temperature of 60-90°C; and / or, the temperature of the feeding and conveying pre-mixing section is 60-70°C; and / or, the temperature of the mixing and kneading section is 75-85°C; and / or, the temperature of the compression and exhaust section is 90-100°C; and / or, the residence time in the parallel twin-screw extruder is 3-4 minutes.

8. The preparation method according to claim 1, wherein: the parallel twin-screw extruder has 6-8 sections of feeding and conveying pre-mixing section, 3-5 sections of mixing and kneading section, 2 sections of compression and exhaust section, and 1 section of exhaust and discharge section.

9. The preparation method according to claim 1, wherein: the screw of the parallel twin-screw extruder is composed of screw elements on a mandrel; the screw elements of the feeding and conveying pre-mixing section are at least two of conveying elements, shearing elements, and intermeshing blocks; the screw elements of the mixing and kneading section are at least two of conveying elements, shearing elements, intermeshing blocks, and toothed discs; and the screw elements of the compression and exhaust section are at least two of conveying elements and shearing elements.

10. A directly high-efficiency coating self-healing rubber prepared by the method of any one of claims 1-9. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​