Method for producing a sealant and sealant

Abstract

The application provides a sealant preparation method and sealant. 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 in an internal mixer to obtain a mixing masterbatch, adding the prepared mixing masterbatch into a single-screw extruder or a conical twin-screw extruder, preheating and pre-plasticizing, and then feeding into a parallel co-rotating twin-screw extruder, adding polyisobutylene through multiple liquid injection ports on the barrel for multiple times, and extruding to obtain the sealant. The application adopts a series screw extruder set of a single-screw pretreatment extruder and a twin-screw mixing and exhaust extruder, adds tackifying resin and a large amount of liquid rubber in the formula, is short in time, high in efficiency, continuous and automatic in process, saves labor, is stable and controllable in production process, and can prepare the sealant with excellent performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rubber, further relates to a preparation method of sealant and the sealant. BACKGROUND

[0002] In order to solve the problems of easy tire burst when traditional tire leaks and expensive but poor performance of run-flat tire, Michelin, Hankook, Kumho and other tire manufacturers began to research tire sealant. The core of the tire technology with self-repairing function is a layer of self-sealing glue with "memory function" uniformly coated on the inner wall of the tire. The layer of self-sealing glue not only has good stress response viscoelasticity, air tightness, tensile strength and aging resistance, but also can still maintain good viscosity and adhesion to the inner layer of the tire under high and low temperature conditions (-40℃-120℃). However, the current self-repairing tire has the problems of diffusion of the adhered self-sealing glue to the periphery (viscosity problem) and local self-sealing glue falling off from the surface of the tire (adhesion problem) during use.

[0003] US9556329B2 discloses a method for preparing self-repairing material. First, a diene solid rubber is mixed with 30 parts of resin above the softening point of the resin by using an internal mixer, and then a crosslinking system is added in the internal mixer or a single screw extruder, and mixed again at 100℃. Thus, the self-repairing rubber material is prepared. The method only uses a small amount of resin in the formula system, and does not use liquid rubber. The viscosity of the obtained self-repairing material is high, which makes it difficult to coat on the inner layer of the tire, and it is difficult to ensure the adhesion and flow properties of the self-repairing material. Therefore, it has not been commercialized.

[0004] The self-repairing tire sealant of the prior art has the disadvantages of high viscosity of the self-sealing glue, poor flowability, poor high temperature resistance, easy softening of the glue and poor strength of the glue after temperature rise, and poor adhesion of the self-sealing glue, which can cause glue falling off, turning up, displacement and glue accumulation during tire running. Therefore, it is necessary to develop a sealant with better performance. SUMMARY

[0005] In order to solve the technical problems in the prior art, the present application provides a preparation method of sealant and the sealant.

[0006] The present application designs a preparation method of sealant. By reasonably designing the formula system, the final product can meet the requirements of various properties. The solid mixing masterbatch is prepared by using an internal mixer, and then the solid mixing masterbatch is uniformly mixed with high content of liquid polyisobutylene by using a screw extruder. Through the control of process parameters, the self-sealing glue product with excellent performance can be obtained, which can be used for self-repairing tire.

[0007] One of the purposes of the present application is to provide a preparation method of sealant, comprising:

[0008] (1) uniformly mixing raw materials including raw rubber, carbon black, white carbon black, antioxidant, tackifying resin, plasticizer, crosslinking agent, crosslinking aid in an internal mixer to obtain a mixed masterbatch; the tackifying resin is at least one of C5 resin, C9 resin, rosin, terpene resin;

[0009] (2) adding the prepared mixed masterbatch into a single screw extruder or a conical twin screw extruder, preheating and preplasticizing, then feeding into a parallel co-rotating twin screw extruder, adding polyisobutylene through multiple liquid injection ports on the barrel in multiple times, and then extruding to obtain the sealant.

[0010] In a preferred embodiment of the present application,

[0011] The mass of the tackifying resin accounts for 10-20% of the total mass of the mixed masterbatch;

[0012] The mass ratio of the mixed masterbatch and polyisobutylene is 1:(1.2-2.8), preferably 1:(1.6-2.6);

[0013] The Mooney viscosity of the mixed masterbatch is 15-35, preferably 20-35;

[0014] The number average molecular weight of the polyisobutylene is 600-2500, preferably 800-1200.

[0015] In a preferred embodiment of the present application,

[0016] The raw rubber is at least one of butyl rubber, natural rubber, isoprene rubber, and thermoplastic elastomer;

[0017] The carbon black is a commonly used commercial carbon black in the art, preferably at least one of N330, N234 or N550;

[0018] The white carbon black is a commonly used commercial white carbon black in the art, preferably at least one of precipitated white carbon black or fumed white carbon black;

[0019] The antioxidant is a commonly used antioxidant in the art, preferably at least one of antioxidant 4020, antioxidant RD, antioxidant 2246;

[0020] The tackifying resin is at least one of C5 resin, C9 resin, rosin, and terpene resin;

[0021] The plasticizer is a commonly used plasticizer in the art, preferably at least one of paraffin oil, naphthenic oil, and environmentally friendly aromatic hydrocarbon oil;

[0022] The crosslinking agent is at least one of sulfur or organic peroxide;

[0023] The crosslinking coagent is a crosslinking coagent commonly used in the art, preferably at least one of zinc oxide, accelerator DM, accelerator CZ, accelerator NS.

[0024] In a preferred embodiment of the present application,

[0025] 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; and / or,

[0026] The addition temperature of the polyisobutylene is 55-100°C, preferably 65-85°C; and / or,

[0027] The barrel temperature of the feeding and conveying premixing section is 50-95°C, preferably 55-65°C; and / or,

[0028] The temperature of the mixing and compounding section is 55-85°C, preferably 65-85°C; and / or,

[0029] The temperature of the compression and exhaust section is 80-120°C, preferably 90-100°C; and / or,

[0030] The residence time in the parallel co-rotating twin screw extruder is 1-4 minutes.

[0031] In a preferred embodiment of the present application,

[0032] The feeding and conveying premixing section and the mixing and compounding section of the 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.

[0033] In a preferred embodiment of the present application,

[0034] The single screw extruder is provided with a forced compression device; and / or,

[0035] The compression ratio of the single screw extruder is 1.05-2.5, and the temperature is 50-100°C; and / or, the conical twin screw extruder is internally provided with a heat conducting oil heating, and the temperature is 60-135°C.

[0036] In a preferred embodiment of the present application,

[0037] 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, preferably 6-8, 3-5, 2 and 1, respectively.

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

[0039] The screw of the parallel co-rotating twin-screw extruder is composed of screw elements on a mandrel;

[0040] The screw elements of the feeding and conveying premixing section are at least two of conveying elements, shearing elements and meshing blocks;

[0041] The elements of the mixing and compounding section are at least two of conveying elements, shearing elements, meshing blocks and toothed discs;

[0042] The compression and exhaust section is at least one of conveying elements and shearing elements.

[0043] In a preferred embodiment of the present application,

[0044] 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);

[0045] 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);

[0046] 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);

[0047] 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).

[0048] The second object of the present application is to provide a sealant prepared by the above method.

[0049] The application is realized by the following process: a method for quickly preparing a sealant for self-repairing tires, characterized in that raw rubber, carbon black, white carbon black, antioxidant, tackifying resin, plasticizer, crosslinking agent and crosslinking aid are uniformly mixed 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 into a single-screw feeding extruder or a conical twin-screw feeding extruder, the end of the extruder is connected with a rubber metering and conveying device, and the preheated and preplasticized mixing masterbatch is quantitatively butted into a parallel co-rotating twin-screw extruder, three or four or five or six liquid injection ports are opened on the feeding and conveying premixing section of the twin-screw extruder, 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 at 55-100℃, the barrel temperature of the feeding section is 50-95℃, then the mixture is extruded through the mixing and compounding section (temperature 55-85℃), the compression and exhaust section (temperature 80-120℃) of the twin-screw extruder, stays for 1-4 minutes, and then is extruded through the exhaust and discharge section (temperature 70-110℃) and the extruder head to obtain the sealant which is uniformly mixed, free of solid particles and bubbles.

[0050] The raw rubber used is preferably a mixture of one or more of butyl rubber, natural rubber, isoprene rubber and thermoplastic elastomer.

[0051] The tackifying resin used is preferably 8%-20% by weight of the mixing masterbatch, and is preferably a mixture of one or more of C5 resin, C9 resin, rosin and terpene resin.

[0052] The single-screw feeding extruder used is preferably provided with a forced compression device, and the compression ratio of the single-screw extruder is preferably 1.05-2.5 and the temperature is preferably 50-100℃.

[0053] The screw of the conical twin-screw feeding extruder used is preferably heated by a heat conducting oil, and the temperature is preferably 60-135℃.

[0054] 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 discharge section of the co-rotating twin-screw extruder used is preferably 4-10, 3-8, 1 and 1-2 respectively.

[0055] The screw of the co-rotating twin-screw extruder used 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 elements, shearing elements and intermeshing blocks, the elements of the mixing and compounding section are preferably two, three or four of conveying elements, shearing elements, intermeshing blocks and toothed discs, and the elements of the compression and exhaust section are preferably one or two of conveying elements and shearing elements.

[0056] 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.

[0057] Compared with the prior art, the present application has the following advantages:

[0058] By comparing and analyzing the current self-sealing adhesive products and the disclosed technical means, the key problems of the self-sealing adhesive products are: high viscosity, poor flowability, poor high temperature resistance, easy to cause the softening of the adhesive and the deterioration of the adhesive strength after temperature rise, and reduce the adhesion of the adhesive; in addition, the adhesion of the self-sealing adhesive is poor, and the tire will produce adhesive falling, turning, displacement and adhesive accumulation during driving. In order to solve the problems existing in the prior art, the present application firstly 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-sealing adhesive still has good flowability and sealing property under low temperature condition; the crosslinking system is added in the formula, so that the self-sealing adhesive is micro-crosslinked during spraying, and a certain degree of network structure is formed, so that the self-sealing adhesive will not flow under high temperature condition; 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-sealing adhesive. The self-sealing adhesive attached to the tire surface spreads to the surrounding, and the viscosity problem; the local self-sealing adhesive falls off from the tire surface, and the adhesion problem.

[0059] In addition, the sealant must be evenly coated on the inside of the tire, and the sealant product has no obvious particles, no bubbles, which is the premise of realizing the uniform coating of the sealant, that is, to ensure that the sealant is a homogeneous system. Because more than 120 parts of PIB liquid are designed to be added in the formula system, and 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, adding a large amount of liquid in the internal mixer will cause slipping phenomenon and is difficult to process, 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 addition amount of liquid PIB in the running process of the mixing masterbatch, the uniform mixing of 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 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 viscosity evolution and uniformity distribution in the extrusion process, the screw element combination of the feeding and conveying premixing section of the twin screw extruder is simulated to make the uniform mixing and dispersion of a large amount of liquid in the rubber continuous phase during the running process of the solid mixing masterbatch, gradually change the viscosity gradient and compatibility, and eliminate the existence of solid particles; at the same time, in the mixing and mixing section of the twin screw extruder, the distribution and mixing of the material are further realized to form a homogeneous system; in the exhaust extrusion section, on the one hand, the screw mixing is used while reducing the screw groove depth, and the material is discharged by the way of mixing and exhausting; on the other hand, in the material discharge section, by increasing the lead and groove depth of the screw element, the material internal gas and the dynamic gas wrapped in the material conveying are further extracted from the outside by vacuumizing.

[0060] 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 master batch and liquid mixing and mixing stage, the time is short, the efficiency is high, the process is continuous and automatic, the labor is saved, and the production process is stable and controllable. Finally, the sealant product obtained by using the present application is not only uniformly mixed, particle-free and bubble-free, which is beneficial to the next coating process, but also has excellent performance after being coated on the inner wall of the tire: under low temperature conditions, it still has good flowability and adhesion strength to the tire; under high temperature conditions, it still has good aging resistance and tensile strength without softening and flowing. DETAILED DESCRIPTION

[0061] The following specific description of the present application is made in conjunction with specific examples, and it is necessary to point out 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, and 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 fall within the protection scope of the present application.

[0062] The raw materials used in the examples are all conventional commercially available raw materials.

[0063] The parts in the examples all refer to weight parts.

[0064] Example 1

[0065] Butyl rubber, isoprene rubber, carbon black N330, white carbon black, antioxidant 4020, C5 tackifying resin (accounting for 12% of the total mass of the mixed rubber), plasticizer paraffin oil, crosslinking agent sulfur and crosslinking aid were uniformly mixed in an internal mixer to prepare a mixed master batch with a Mooney viscosity of 20;

[0066] 100 parts (weight parts) of the mixed master batch were added into a single screw extruder with a forced pressure device, the diameter of the single screw extruder was 120 mm, the length-diameter ratio was 8:1, the compression ratio of the single screw extruder was 2.5, and the temperature was 100℃. The end of the single screw extruder was connected with a rubber metering conveying device, and the preheated and preplasticized mixed master batch was quantitatively butted into a parallel co-rotating twin screw extruder (the diameter was 90 mm, the length-diameter ratio was 60:1, and the number of barrels was 15). The feeding conveying pre-mixing section was 8 sections, and the screw elements included conveying elements, shearing elements and engagement blocks. The mixing and mixing section was 4 sections, and the elements were conveying elements, engagement blocks and toothed discs. The compression and exhaust section was 2 sections, and the elements were shearing and compression elements. The number of barrels of the exhaust and discharge section was 1 section.

[0067] The feeding and conveying premixing section and the mixing and kneading section of the twin-screw extruder have six liquid injection ports. The first and second injection ports are in the feeding and conveying premixing section, and the two injection ports are spaced apart by one barrel section. The third injection port is at the end of the feeding and conveying premixing section, and the third injection port is spaced apart from the second injection port by two barrel sections. Further preferably, the fourth, fifth, and sixth injection ports are arranged in the mixing and kneading section. A total of 260 parts by weight of polyisobutylene PIB having a number average molecular weight of 1200 is added in sequence through the liquid metering feeding device, and the proportions of the six liquid injection ports are 1:1.1:2.5:4:6:8. The addition temperature of the polyisobutylene at the first three injection ports is 65°C, the addition temperature of the polyisobutylene at the fourth and fifth injection ports is 75°C, and the addition temperature of the polyisobutylene at the sixth injection port is 85°C. The barrel temperature of the feeding section is 60°C. Then, the product is extruded through the mixing and kneading section (temperature 80°C) and the compression venting section (temperature 90°C) of the twin-screw extruder, stays for 4 minutes, and is then extruded through the discharge section and the extruder head to obtain a self-sealing adhesive product.

[0068] The obtained sealing adhesive product has no particles, and no obvious solid particles are observed under a microscope at 30 times magnification. After standing for 24 hours, the product surface has no obvious bubbles. The adhesion strength at -40°C is 5% lower than that at 20°C, and the adhesion strength retention rate is good. At 150°C, the viscosity of the product is 2% lower than that at 20°C, and the viscosity retention rate is good, and no softening and flowing phenomenon occurs. In the subsequent spraying process, spraying at 135°C can uniformly coat the inside of the tire.

[0069] Example 2

[0070] Butyl rubber, thermoplastic elastomer, carbon black N330, white carbon black, antioxidant 4020, C9 tackifying resin (20% of the total mass of the mixed rubber), plasticizer paraffin oil, crosslinking agent sulfur, and crosslinking aid are uniformly mixed in an internal mixer to obtain a mixed masterbatch with a Mooney viscosity of 35;

[0071] The 100 parts (by weight) of the mixed masterbatch is added into a conical twin-screw feeding extruder, the internal heat conduction oil temperature of the screw is 95°C, the end of the conical twin-screw extruder is connected with a rubber metering conveying device, and the preheated and preplasticized mixed masterbatch is quantitatively connected into a parallel co-rotating twin-screw extruder (the diameter is 85 mm, the length-diameter ratio is 48:1, and the number of barrels is 12) in a quantitative manner. The feeding and conveying pre-mixing section is 6 barrels, and the screw elements include conveying elements, shearing elements, and meshing blocks. The mixing and mixing section is 3 barrels, and the elements are conveying elements, meshing blocks, and toothed discs. The compression and exhaust section is 2 barrels, and the elements adopt shearing and compression elements. The number of barrels of the exhaust and discharge section is 1. The feeding and conveying pre-mixing section and the mixing and mixing section of the twin-screw extruder are provided with 5 liquid injection ports. The first and second injection ports are in the feeding and conveying pre-mixing section, and the two injection ports are spaced apart by 1 barrel. The third injection port is at the end of the feeding and conveying pre-mixing section, and the third injection port is spaced apart from the second injection port by 2 barrels. Further preferably, the fourth and fifth injection ports are arranged in the mixing and mixing section. A total of 180 parts (by weight) of polyisobutylene PIB with a number average molecular weight of 800 is added through a liquid metering feeding device in sequence, the ratio of the 5 liquid injection ports is 1:1.5:3:5:10, the addition temperature of the polyisobutylene in the first 3 injection ports is 60°C, the addition temperature of the polyisobutylene in the last 2 injection ports is 70°C, the barrel temperature of the feeding section is 65°C, and then the product of the self-sealing glue is obtained after the mixture is extruded through the mixing and mixing section (temperature 85°C) of the twin-screw extruder, the compression and exhaust section (temperature 100°C), the residence time is 3 minutes, and the discharge section and the extruder head.

[0072] The obtained sealant product has no particles, and no obvious solid particles are observed under a microscope with 30 times magnification. After standing for 24 hours, there is no obvious bubble on the surface of the product. The adhesion strength at -40°C is decreased by 2% compared with that at 20°C, and the adhesion strength retention rate is good. At 150°C, the viscosity of the product is decreased by 5% compared with that at 20°C, and the viscosity retention rate is good, and no softening and flowing phenomenon occurs. In the subsequent spraying process, spraying at 130°C can be used to uniformly coat the inside of the tire.

[0073] Example 3

[0074] The natural rubber, butyl rubber, carbon black N330, white carbon black, antioxidant 4020, C5 tackifying resin (10% of the total mass of the mixed rubber), plasticizer paraffin oil, crosslinking agent sulfur, and crosslinking aid are uniformly mixed in an internal mixer to prepare a mixed masterbatch with a Mooney viscosity of 21.

[0075] 100 parts by weight of the mixed masterbatch is added into a conical twin-screw feeding extruder, the internal heat conduction oil temperature of the screw is 85°C, the end of the conical twin extruder is connected with a rubber metering conveying device, and the preheated and preplasticized mixed masterbatch is quantitatively butted into a parallel and co-directional twin-screw extruder (the diameter is 60 mm, the length-diameter ratio is 60:1, and the number of barrels is 15); the feeding and conveying pre-mixing section is 7, the screw elements include conveying elements, shearing elements and meshing blocks; the mixing and mixing section is 5, the elements are conveying elements, meshing blocks and toothed discs, the compression and exhaust section is 2, the elements adopt shearing and compression elements, and the number of barrels of the exhaust and discharge section is 1; the feeding and conveying pre-mixing section and the mixing and mixing section of the twin-screw extruder are provided with four liquid injection ports, the first and second injection ports are in the feeding and conveying pre-mixing section, and the two injection ports are spaced apart by 1 barrel; the third injection port is at the end of the feeding and conveying pre-mixing section, and the third injection port is spaced apart from the second injection port by 2 barrels; further preferably, the fourth injection port is arranged in the mixing and mixing section. A total of 160 parts (by weight) of polyisobutylene PIB with a number average molecular weight of 1000 is added through a liquid metering feeding device in sequence, the ratio of the four liquid injection ports is 1:2:4:10, the addition temperature of the polyisobutylene in the first two injection ports is 65°C, the addition temperature of the polyisobutylene in the last two injection ports is 75°C, the barrel temperature of the feeding section is 55°C, then the product is obtained by extruding through the mixing and mixing section (temperature 65°C) of the twin-screw extruder, the compression and exhaust section (temperature 90°C) with a residence time of 2 minutes, and the discharge section and the extruder head.

[0076] The obtained sealant product has no particles, and no obvious solid particles are observed under a microscope with a magnification of 50 times. After standing for 24 hours, the product surface has no obvious bubbles, the adhesion strength at -40°C is decreased by 2.5% compared with that at 20°C, the adhesion strength retention rate is good; at 150°C, the viscosity of the product is decreased by 1.5% compared with that at 20°C, the viscosity retention rate is good, and no softening and flowing phenomenon occurs. In the subsequent spraying process, spraying at 150°C can be used to uniformly coat the inside of the tire.

Claims

1. A method for preparing a sealant, characterized by The method comprises: (1) uniformly mixing raw materials including raw rubber, carbon black, white carbon black, antioxidant, tackifying resin, plasticizer, crosslinking agent, crosslinking aid in an internal mixer to prepare a mixed masterbatch; the tackifying resin is at least one of C5 resin, C9 resin, rosin, terpene resin; (2) adding the prepared mixed masterbatch into a single-screw extruder or a conical twin-screw extruder, preheating and preplasticizing, then feeding into a parallel co-rotating twin-screw extruder, adding polyisobutylene through multiple liquid injection ports on the barrel in multiple times, and extruding to obtain the sealant; In step (1), the mass of the tackifying resin accounts for 10-20% of the total mass of the mixed masterbatch; the Mooney viscosity of the mixed masterbatch is 15-35; 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 venting section, and a venting and discharging section; The number of barrels of the feeding and conveying premixing section, the mixing and compounding section, the compression and venting section, and the venting and discharging section of the parallel co-rotating twin-screw extruder is 4-10 sections, 3-8 sections, 1-2 sections, and 1 section, respectively; The feeding and conveying premixing section and the mixing and compounding section of the parallel co-rotating twin-screw extruder have 3-6 liquid injection ports; the first and second injection ports are in the feeding and conveying premixing section, and the two injection ports are at least separated by 1 section of barrel; the third injection port is at the end of the feeding and conveying premixing section, and the third injection port is separated from the second injection port by at least 2 sections of barrel; 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 3 liquid injection ports, the mass ratio of the addition in the order of sequence is 1:(1.3-3): (1.5-10); When the polyisobutylene is added through 4 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); When the polyisobutylene is added through 5 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); When the polyisobutylene is added through 6 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); The addition temperature of the polyisobutylene is 55-100℃; The barrel 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 venting section is 80-120℃.

2. The preparation method of the sealant according to claim 1, characterized in that: The mass ratio of the mixed masterbatch to the polyisobutylene is 1:(1.6-2.6); and / or, The Mooney viscosity of the mixed masterbatch is 20-35; and / or, The number average molecular weight of the polyisobutylene is 800-1200.

3. The preparation method of the sealant according to claim 1, characterized in that: The raw rubber is at least one of butyl rubber, natural rubber, isoprene rubber, and thermoplastic elastomer; and / or, The white carbon black is at least one of precipitated white carbon black and fumed white carbon black; and / or, The plasticizer is at least one of paraffin oil, naphthenic oil, and environmentally friendly aromatic oil; and / or, The crosslinking agent is at least one of sulfur and organic peroxide; and / or, The crosslinking coagent is at least one of zinc oxide, accelerator DM, accelerator CZ, and accelerator NS.

4. The method for preparing the sealant according to claim 1, wherein: The residence time in the parallel co-rotating twin-screw extruder is 1-4 minutes.

5. The method for preparing the sealant according to claim 4, wherein: The addition temperature of polyisobutylene is 65-85°C; and / or, The barrel temperature of the feeding and conveying premixing section is 55-65°C; and / or, The temperature of the mixing and compounding section is 65-85°C; and / or, The temperature of the compression and venting section is 90-100°C.

6. The method for preparing the sealant according to claim 1, wherein: The single-screw extruder is provided with a forced pressure device; and / or, The compression ratio of the single-screw extruder is 1.05-2.5, and the temperature is 50-100°C; and / or, The conical twin-screw extruder is internally provided with a heat-conducting oil heating system, and the temperature is 60-135°C.

7. The method for preparing the sealant according to claim 1, wherein: The number of barrels of the feeding and conveying premixing section, the mixing and compounding section, the compression and venting section, and the venting and discharging section of the parallel co-rotating twin-screw extruder is 6-8, 3-5, 2, and 1, respectively.

8. The method for preparing the sealant according to claim 1, wherein: The screw of the parallel co-rotating twin-screw extruder is composed of screw elements on a mandrel; and / or, The screw elements of the feeding and conveying premixing section are at least two of conveying elements, shearing elements, and intermeshing blocks; and / or, The elements of the mixing and compounding section are at least two of conveying elements, shearing elements, intermeshing blocks, and toothed discs; and / or, The elements of the compression and venting section are at least two of conveying elements and shearing elements.

9. A sealant prepared by the method according to any one of claims 1-8.