Burning-resistant sealant applied to green building and preparation process of burning-resistant sealant

Abstract

The invention discloses a firing-resistant sealant applied to green buildings and a preparation process of the firing-resistant sealant, and the firing-resistant sealant comprises a core layer and covering adhesive layers arranged on two sides of the core layer. The covering rubber layer is prepared from the following components: 80 to 120 parts of butylbenzene sealant, 0.2 to 1.0 part of vulcanizing agent, 0.5 to 3.0 parts of accelerant, 2 to 6 parts of anti-aging agent, 3 to 7 parts of zinc oxide, 1.0 to 2.5 parts of stearic acid, 5 to 15 parts of coumarone, 40 to 60 parts of carbon black, 5 to 10 parts of zinc borate, 5 to 10 parts of aluminum hydroxide and 5 to 10 parts of glass fiber. The covering glue layer and the core layer are bonded and then vulcanized at the temperature of 140-155 DEG C and the pressure of 10-15 Mpa to obtain the firing-resistant sealant. Coumarone resin is added, the carbon forming effect is improved, a compact carbon layer is formed, heat transfer is isolated, the service life of the product is prolonged, the synergistic effect of zinc borate and aluminum hydroxide is matched, the carbon forming effect is improved, the flame retardant property is improved, a three-dimensional supporting framework is built through glass fibers, and collapse of the material at high temperature is delayed; zinc borate and aluminum hydroxide are synergistically decomposed to form a compact ceramic barrier layer, and the temperature resistance reaches 500 DEG C or above.

Description

Technical Field

[0001] The present invention relates to the field of green buildings, and particularly to a high-temperature-resistant sealant applied in green buildings and a preparation process thereof. Background Art

[0002] Green building is an inevitable trend in the future development of buildings. Its core lies in balancing human needs and natural ecology, and achieving sustainable development through technological innovation and scientific management. If the high-temperature-resistant sealant meets the requirements such as low VOC, fire resistance, and durability, it will become an indispensable environmental protection material in green buildings.

[0003] The current prior art has the following defects: Traditional silicone sealants have insufficient high-temperature resistance (usually ≤ 200 °C) and are prone to failure in case of fire; 2. Sealants containing halogen flame retardants release toxic gases when burning, which does not meet the environmental protection requirements of green buildings; 3. Some high-temperature-resistant materials (such as ceramic adhesives) have high costs and poor workability.

[0004] At the same time, the requirements of green buildings need to meet the requirements for material environmental protection, fire resistance, and durability in the "Green Building Assessment Standard"; and it needs to pass the certification of the National Quality Supervision and Inspection Center for Fireproof Building Materials (such as GB / T 2408-2008 V-0 level). Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a high-temperature-resistant sealant applied in green buildings and a preparation process thereof. By adding coumarone resin, the carbonization effect is improved, a dense carbon layer is formed to isolate heat transfer, and the service life of the product is extended. Then, the synergistic effect of zinc borate and aluminum hydroxide is combined to improve the carbonization effect and the flame retardant performance. By adding glass fibers, which are interspersed in the carbon layer, not only significantly improves the heat isolation effect, but also provides good supporting ability to prevent greater damage to the belt body by high-temperature materials and extends the service life of the product. The glass fibers build a three-dimensional support framework to delay the collapse of materials at high temperatures; zinc borate and aluminum hydroxide decompose synergistically to form a dense ceramic barrier layer with a temperature resistance of over 500 °C. The styrene-butadiene rubber matrix provides excellent elasticity (elongation at break ≥ 300%) to adapt to dynamic displacement; the antioxidant combination inhibits thermal oxygen aging, and the strength retention rate is ≥ 85% after 1000 hours of hot air aging at 150 °C.

[0006] The technical solution adopted by the present invention is as follows: a burn-resistant sealant applied in green buildings, which includes a core layer and covering adhesive layers arranged on both sides of the core layer. By weight, the covering adhesive layer is made of the following components: including 80-120 parts of styrene-butadiene sealant, 0.2-1.0 part of vulcanizing agent, 0.5-3.0 parts of accelerator, 2-6 parts of antioxidant, 3-7 parts of zinc oxide, 1.0-2.5 parts of stearic acid, 5-15 parts of coumarone, 40-60 parts of carbon black, 5-10 parts of zinc borate, 5-10 parts of aluminum hydroxide, and 5-10 parts of glass fiber. After the covering adhesive layer and the core layer are bonded, they are vulcanized at 140-155 °C under a pressure of 10 Mpa to 15 Mpa to obtain the burn-resistant sealant.

[0007] On the basis of the above solution, preferably, the accelerators are accelerator NS and accelerator DTDM; The vulcanizing agent is TMTD; The antioxidants are antioxidant RD, antioxidant 4020, and antioxidant MB, and the ratio is 1:2:1; The styrene-butadiene sealant is an un-oiled styrene-butadiene sealant, and the combined styrene content is 30%-35%; The carbon black is one or more of N115, N220, N550, and white carbon black; The glass fiber is long glass fiber with a size of 10-15 mm.

[0008] On the basis of the above solution, preferably, the core layer includes a reinforcing layer, and the reinforcing layer is woven from main warp yarns, binding warp yarns, and weft yarns.

[0009] On the basis of the above solution, preferably, the main warp yarn is a special cord made by re-twisting multiple strands of initially twisted cord. The initially twisted cord has ultra-high molecular weight polyethylene fiber or polyarylate fiber at the center as the core fiber, and the periphery of the core fiber is wrapped with an outer layer fiber that plays a role in improving the tensile strength and enhancing the interfacial adhesion. The outer layer fiber is wrapped around the core fiber in a parallel and side-by-side manner or by twisting in a spiral winding manner. The fiber materials of the special cord include one or several of ultra-high molecular weight polyethylene fiber, polyarylate fiber, polyaramide fiber, polyimide fiber, poly(p-phenylene benzobisoxazole) fiber, and polyvinyl acetal fiber. The elongation at break of the special cord is between 2% and 6%, and the fineness is 500 dtex to 6000 dtex. The molecular weight of the ultra-high molecular weight polyethylene fiber is higher than 1 million. The outer layer fiber includes one or several of polyarylate fiber, polyaramide fiber, polyimide fiber, poly(p-phenylene benzobisoxazole) fiber, and polyvinyl acetal fiber.

[0010] On the basis of the above solution, preferably, the bundling warp includes one or more of nylon 66, nylon 6, polyvinyl acetal fiber, and polyester fiber, with a fineness of 550 - 4000 dtex; the bundling warp is a twisted yarn formed by twisting 1 - 5 strands of bundling warp.

[0011] On the basis of the above solution, preferably, the weft includes one or more of nylon 66, nylon 6, polyvinyl acetal fiber, and polyester fiber, with a fineness of 550 - 4000 dtex; the weft is a twisted yarn formed by twisting 1 - 12 strands of weft.

[0012] A preparation process of a fire - resistant sealant, which is made using the above - mentioned raw materials, includes the following steps: Mixing process: Charge styrene - butadiene sealant, antioxidant, zinc oxide, stearic acid, coumarone resin, zinc borate, aluminum hydroxide, glass fiber, N220 carbon black, vulcanizing agent, and accelerator into a Banbury mixer in sequence according to the weight ratio for mixing. Calendering and forming: After the mixing is completed, calender the obtained mixed rubber sheet into a sheet shape by a three - roll calender to obtain a cover rubber layer. Vulcanization process: After thermally laminating the cover rubber sheet with the core layer, vulcanize to obtain the fire - resistant sealant.

[0013] On the basis of the above solution, preferably, the mixing time in the mixing process is 5 - 15 min.

[0014] On the basis of the above solution, preferably, the thickness of the cover rubber layer in the calendering and forming process is 1.2 ± 0.05 mm.

[0015] A post - treatment method for a reinforcing layer. After the reinforcing layer is prepared, the following treatment process is used for treatment: Step 1: First, impregnate with the first bath impregnating solution, dry and heat - treat at 100 - 120 °C for 20 - 50 min; Step 2: Then, impregnate with the second bath dipping solution, dry and heat - treat at 110 - 140 °C for 30 - 100 min to prepare an impregnated canvas that can be used for a high - temperature resistant rubber conveyor belt. The components of the first bath impregnating solution are: by mass fraction, 1% - 5% of water - soluble epoxy resin, 0 - 2% of blocked isocyanate, 0 - 2% of water - based curing agent for epoxy resin, and the rest is deionized water.

[0016] The second bath dipping latex comprises latex and an aqueous binder, and the mixing ratio of the latex to the aqueous binder is 85:15 to 60:40; the latex comprises one or more of butadiene-acrylonitrile latex, natural latex, styrene-butadiene latex, carboxylated styrene-butadiene, and carboxylated acrylonitrile-butadiene latex; the aqueous binder is an aqueous solution of phenolic resin or a mixed aqueous solution of blocked isocyanate, epoxy resin, and aqueous imidazole curing agent.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) By adding coumarone resin, the carbonization effect is improved to form a dense carbon layer, isolating heat transfer and enhancing the service life of the product. Then, in combination with the synergistic effect of zinc borate and aluminum hydroxide, the carbonization effect is further enhanced and the flame retardancy is improved.

[0018] (2) By adding glass fiber, which is interspersed in the carbon layer, not only significantly improves the heat isolation effect, but also provides good supporting ability, preventing greater damage to the belt body by high-temperature materials and enhancing the service life of the product.

[0019] (3) High-temperature resistance mechanism: Glass fiber constructs a three-dimensional support framework to delay the collapse of materials at high temperatures; zinc borate and aluminum hydroxide decompose synergistically to form a dense ceramic barrier layer with a temperature resistance of over 500 °C.

[0020] (4) Long-life design: The styrene-butadiene rubber matrix provides excellent elasticity (elongation at break ≥ 300%) to adapt to dynamic displacement; the antioxidant combination inhibits thermal-oxidative aging, and the strength retention rate is ≥ 85% after 1000 hours of hot air aging at 150 °C. Description of the Drawings

[0021] Figure 1 is a schematic structural view of the reinforcing layer of the present invention. Detailed Embodiments

[0022] The present invention will be further described below through examples, but the scope of the present invention is not limited thereto.

[0023] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] A high-temperature resistant sealant, comprising a core layer and covering rubber layers provided on both sides of the core layer. By weight, the covering rubber layer is made of the following components: 80-120 parts of styrene-butadiene sealant, 0.2-1.0 part of vulcanizing agent, 0.5-3.0 parts of accelerator, 2-6 parts of antioxidant, 3-7 parts of zinc oxide, 1.0-2.5 parts of stearic acid, 5-15 parts of coumarone, 40-60 parts of carbon black, 5-10 parts of zinc borate, 5-10 parts of aluminum hydroxide, and 5-10 parts of glass fiber; Among them: the accelerator is accelerator NS and accelerator DTDM; the vulcanizing agent is TMTD; the antioxidant is antioxidant RD, antioxidant 4020, and antioxidant MB, with a ratio of 1:2:1; the styrene-butadiene sealant is an un-oiled styrene-butadiene sealant with a bound styrene content of 30%; the carbon black is one or more of N115, N220, N550, and white carbon black; the glass fiber is long glass fiber with a size of 10-15 mm.

[0025] The core layer includes a reinforcing layer, as Figure 1 shown. The reinforcing layer is woven from main warp yarns, binding warp yarns, and weft yarns. The main warp yarns are special yarns made by re-twisting multiple strands of initially twisted yarn ropes. The initially twisted yarn ropes have ultra-high molecular weight polyethylene fibers or polyarylate fibers at the center as inner core fibers. The periphery of the inner core fibers is wrapped with outer layer fibers that play a role in improving the tensile strength and enhancing the interfacial adhesion. The outer layer fibers are wrapped around the inner core fibers in a parallel side-by-side manner or by twisting in a spiral winding manner. The fiber materials of the special yarn ropes include one or several of ultra-high molecular weight polyethylene fibers, polyarylate fibers, polyaramide fibers, polyimide fibers, poly(p-phenylene benzobisoxazole) fibers, and polyvinyl acetal fibers. The breaking elongation rate of the special yarn ropes is between 2% and 6%, and the fineness is between 500 dtex and 6000 dtex. The molecular weight of the ultra-high molecular weight polyethylene fibers is higher than 1 million. The outer layer fibers include one or several of polyarylate fibers, polyaramide fibers, polyimide fibers, poly(p-phenylene benzobisoxazole) fibers, and polyvinyl acetal fibers.

[0026] The binding warp yarns include one or several of nylon 66, nylon 6, polyvinyl acetal fibers, and polyester fibers, with a fineness of 550-4000 dtex; the binding warp yarns are twisted yarns formed by combining 1-5 strands of binding warp yarns.

[0027] The weft yarn includes one or more of nylon 66, nylon 6, polyvinyl acetal fiber, and polyester fiber, and has a fineness of 550 - 4000 dtex; the weft yarn is a twisted yarn formed by twisting 1 - 12 strands of weft yarn. Further, each component in the cover rubber layer is added to a mixer in the feeding order of raw rubber, small ingredients (anti - aging agent, zinc oxide, stearic acid, coumarone, carbon black, zinc borate, aluminum hydroxide, glass fiber), carbon black, and vulcanizing agent in the required weight parts and mixed for 5 - 15 minutes to obtain a mixed rubber sheet. Subsequently, the mixed rubber sheet is calendered to obtain a cover rubber sheet, and the cover rubber sheet is bonded to the core layer and vulcanized at 150°C ± 5 and a pressure of 10 Mpa - 15 Mpa to obtain the burn - resistant sealant.

[0028] There are no specific restrictions on the stearic acid, zinc oxide, zinc borate, etc. described in the present invention, as long as they do not limit the object of the present invention. Example 1

[0029] A burn - resistant sealant includes a core layer and cover rubber layers provided on both sides of the core layer. By weight, the cover rubber layer is made of the following components: 100 parts of styrene - butadiene sealant, 1.0 part of vulcanizing agent, 2.8 parts of accelerator, 4 parts of anti - aging agent, 7 parts of zinc oxide, 2 parts of stearic acid, 10 parts of coumarone, 50 parts of N220 carbon black, 6 parts of zinc borate, 6 parts of aluminum hydroxide, and 10 parts of glass fiber.

[0030] Each component in the cover rubber layer is added to a mixer in the feeding order of styrene - butadiene sealant, anti - aging agent, zinc oxide, stearic acid, coumarone, carbon black, zinc borate, aluminum hydroxide, glass fiber, vulcanizing agent, and accelerator in the required weight parts and mixed for 6 minutes to obtain a mixed rubber sheet. Subsequently, the mixed rubber sheet is calendered to obtain a cover rubber layer, and the cover rubber sheet is bonded to the core layer and vulcanized at 150°C ± 5 and a pressure of 10 Mpa to obtain the burn - resistant sealant. Example 2

[0031] A burn - resistant sealant includes a core layer and cover rubber layers provided on both sides of the core layer. By weight, the cover rubber layer is made of the following components: 100 parts of styrene - butadiene sealant, 1.0 part of vulcanizing agent, 2.8 parts of accelerator, 4 parts of anti - aging agent, 7 parts of zinc oxide, 2 parts of stearic acid, 10 parts of coumarone, 50 parts of N220 carbon black, 6 parts of zinc borate, 6 parts of aluminum hydroxide, and 5 parts of glass fiber. Its manufacturing process is the same as that of Example 1. Example 3

[0032] A fire-resistant sealant, comprising a core layer and covering rubber layers disposed on both sides of the core layer. By weight, the covering rubber layer is made of the following components: 100 parts of styrene-butadiene sealant, 1.0 part of vulcanizing agent, 2.8 parts of accelerator, 4 parts of antioxidant, 7 parts of zinc oxide, 2 parts of stearic acid, 15 parts of coumarone, 50 parts of N220 carbon black, 6 parts of zinc borate, 6 parts of aluminum hydroxide, and 5 parts of glass fiber. Its manufacturing process is the same as that of Example 1. Example 4

[0033] A preparation method of a high-strength reinforcing layer. When the reinforcing layer is obtained, the following treatment process can be adopted to obtain the best performance: Step 1: First, impregnate with the first bath impregnating solution, and after drying and heat treatment at 100 - 120 °C for 20 - 50 min; Step 2: Then, impregnate with the second bath dipping solution, and after drying and heat treatment at 110 - 140 °C for 30 - 100 min, prepare an impregnated canvas that can be used for high-temperature resistant rubber conveyor belts.

[0034] The components of the first bath impregnating solution are (mass fraction): 1% - 5% of water-soluble epoxy resin, 0 - 2% of blocked isocyanate, 0 - 2% of water-based curing agent for epoxy resin, and the rest is deionized water.

[0035] The second bath dipping solution includes latex and water-based adhesive, and the mixing ratio of latex to water-based adhesive is 85:15 - 60:40; preferably 70:30. The latex includes one or more of butadiene-acrylonitrile latex, natural latex, styrene-butadiene latex, carboxylated styrene-butadiene, and carboxylated nitrile butadiene latex; the water-based adhesive is an aqueous solution of phenolic resin or a mixed aqueous solution of blocked isocyanate, epoxy resin, and water-based imidazole curing agent.

[0036] Comparative Example 1: A fire-resistant sealant, comprising a core layer and covering rubber layers disposed on both sides of the core layer. By weight, the covering rubber layer is made of the following components: 100 parts of styrene-butadiene sealant, 1.0 part of vulcanizing agent, 2.8 parts of accelerator, 4 parts of antioxidant, 7 parts of zinc oxide, 2 parts of stearic acid, 50 parts of N220 carbon black, 6 parts of zinc borate, and 6 parts of aluminum hydroxide. Its manufacturing process is the same as that of Example 1.

[0037] Comparative Example 2:

[0038] A fire-resistant sealant, comprising a core layer and covering rubber layers disposed on both sides of the core layer. By weight, the covering rubber layer is made of the following components: 100 parts of styrene-butadiene sealant, 1.0 part of vulcanizing agent, 2.8 parts of accelerator, 4 parts of antioxidant, 7 parts of zinc oxide, 2 parts of stearic acid, 10 parts of coumarone, 50 parts of N220 carbon black, 6 parts of zinc borate, and 6 parts of aluminum hydroxide. Its manufacturing process is the same as that of Example 1.

[0039] Comparative Example 3:

[0040] A high-temperature resistant sealant includes a core layer and cover rubber layers provided on both sides of the core layer. By weight, the cover rubber layer is made of the following components: 100 parts of styrene-butadiene sealant, 1.0 part of vulcanizing agent, 2.8 parts of accelerator, 4 parts of antioxidant, 7 parts of zinc oxide, 2 parts of stearic acid, 10 parts of coumarone, 50 parts of N220 carbon black, and 6 parts of aluminum hydroxide. The manufacturing process is the same as that of Example 1.

[0041] The measurement method of the present invention follows the following standards: The physical and mechanical properties of the cover rubber layer of the sealant are tested according to the ASTM D412 standard to test the mechanical properties of the composite material; for the tensile test, dumbbell-shaped specimens are prepared using a 6.00 mm wide cutter, the tensile speed is 500 mm / min, and the test temperature is 25 °C; Table 1: Performance comparison of Examples 1-3 and Comparative Examples 1-3 of the present invention Performance Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Tensile strength / MPa 20.6 23.0 20.8 24.1 22.9 23.1 Elongation at break / % 660 650 636 700 701 691 <![CDATA[Wear / mm 3 > 136 131 139 144 155 150 Burning depth / mm 0.07 0.21 0.15 1.12 0.72 1.04 Burning width / mm 5 7 6 13 9 12 The high-temperature resistant test method of the sealant is carried out according to the HG / T 4732-2014 standard. The specific test method is as follows: Select an iron ball with a diameter of 30 mm, heat it fully in a muffle furnace to 800 °C, take it out and place it on the high-temperature resistant belt surface, start timing for 5 min, and compare the charring depth and width.

[0042] By comparing Examples 1-3 and Comparative Examples 1-2, it can be seen that through the synergistic effect of coumarone resin, zinc borate and aluminum hydroxide, the high-temperature resistant performance of the product is significantly improved; further adding long glass fibers further enhances the high-temperature resistant performance.

[0043] It should be noted that the above-described embodiments are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described by referring to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than limiting words. Modifications can be made to the present invention within the scope of the claims of the present invention, and the present invention can be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein. On the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A burn-resistant sealant applied in green buildings, characterized in that, It includes a core layer and cover rubber layers provided on both sides of the core layer. By weight, the cover rubber layer is made of the following components: including 80-120 parts of styrene-butadiene sealant, 0.2-1.0 part of vulcanizing agent, 0.5-3.0 parts of accelerator, 2-6 parts of antioxidant, 3-7 parts of zinc oxide, 1.0-2.5 parts of stearic acid, 5-15 parts of coumarone, 40-60 parts of carbon black, 5-10 parts of zinc borate, 5-10 parts of aluminum hydroxide, and 5-10 parts of glass fiber. After the cover rubber layer is bonded to the core layer, it is vulcanized at 140-155 °C under a pressure of 10 Mpa to 15 Mpa to obtain the burn-resistant sealant.

2. The burn-resistant sealant applied in a green building according to claim 1, characterized in that The accelerator is accelerator NS and accelerator DTDM; The vulcanizing agent is TMTD; The antioxidant is antioxidant RD, antioxidant 4020, and antioxidant MB, with a ratio of 1:2:1; The styrene-butadiene sealant is an un-oiled styrene-butadiene sealant, and the combined styrene content is 30%-35%; The carbon black is one or more of N115, N220, N550, and white carbon black; The glass fiber is long glass fiber with a size of 10-15 mm.

3. The burn-resistant sealant applied in a green building according to claim 1, characterized in that The core layer includes a reinforcing layer, and the reinforcing layer is woven from main warp yarns, binding warp yarns, and weft yarns.

4. The fire-resistant sealant applied in a green building as claimed in claim 3, characterized in that, The main warp yarn is a special yarn rope made by re-twisting multiple strands of initially twisted yarn ropes. The initially twisted yarn ropes have ultra-high molecular weight polyethylene fibers or polyarylate fibers at the center as inner core fibers, and the periphery of the inner core fibers is wrapped with outer layer fibers that play a role in improving the tensile strength and enhancing the interfacial adhesion. The outer layer fibers are wrapped around the inner core fibers in a parallel side-by-side manner or by twisting in a helical winding manner. The fiber materials of the special yarn rope include one or several of ultra-high molecular weight polyethylene fibers, polyarylate fibers, polyaramide fibers, polyimide fibers, poly(p-phenylene benzobisoxazole) fibers, and polyvinyl acetal fibers. The breaking elongation rate of the special yarn rope is between 2% and 6%, and the fineness is 500 dtex to 6000 dtex. The molecular weight of the ultra-high molecular weight polyethylene fiber is higher than 1 million. The outer layer fibers include one or several of polyarylate fibers, polyaramide fibers, polyimide fibers, poly(p-phenylene benzobisoxazole) fibers, and polyvinyl acetal fibers.

5. The burn-resistant sealant applied in a green building as claimed in claim 3, wherein The binding warp yarns include one or several of nylon 66, nylon 6, polyvinyl acetal fibers, and polyester fibers, with a fineness of 550-4000 dtex; the binding warp yarns are twisted yarns formed by combining 1-5 strands of binding warp yarns.

6. The fire-resistant sealant applied in a green building as claimed in claim 3, wherein The weft yarns include one or several of nylon 66, nylon 6, polyvinyl acetal fibers, and polyester fibers, with a fineness of 550-4000 dtex; the weft yarns are twisted yarns formed by combining 1-12 strands of weft yarns.

7. A preparation process of a high-temperature resistant sealant, which is made from the raw materials described in any one of claims 1-7, characterized in that, It includes steps: Mixing process: Styrene-butadiene sealant, anti-aging agent, zinc oxide, stearic acid, coumarone resin, zinc borate, aluminum hydroxide, glass fiber, N220 carbon black, vulcanizing agent, and accelerator are sequentially added to the internal mixer according to the weight ratio for mixing; Calendering: After mixing, the obtained mixed rubber sheet is calendered into a sheet by a three-roll calender to obtain a cover rubber layer; Vulcanization process: After the cover rubber sheet is thermally bonded to the core layer, it is vulcanized to obtain a burn-resistant sealant.

8. The preparation process of the high-temperature-resistant sealant according to claim 7, characterized in that, The mixing time in the mixing process is 5 - 15 min.

9. The preparation process of the high-temperature-resistant sealant according to claim 7, characterized in that, The thickness of the cover rubber layer in calendering is 1.2 ± 0.05 mm.

10. The preparation process of the high-temperature resistant sealant according to claim 7, characterized in that, The reinforcing layer is post-treated using the following treatment process: Step 1: First, impregnation treatment is carried out using the first bath impregnating solution, and after drying and heat treatment at 100 - 120 °C for 20 - 50 min; Step 2: Then, impregnation treatment is carried out using the second bath dipping solution, and after drying and heat treatment at 110 - 140 °C for 30 - 100 min, an impregnated canvas for a high-temperature resistant rubber conveyor belt is prepared. The components of the first bath impregnating solution are: by mass fraction, 1% - 5% water-soluble epoxy resin, 0 - 2% blocked isocyanate, 0 - 2% aqueous curing agent for epoxy resin, and the rest is deionized water. The second bath dipping solution includes latex and an aqueous adhesive, and the solid ratio of latex to aqueous adhesive is 85:15 - 60:40; the latex includes one or more of butadiene-acrylonitrile latex, natural latex, styrene-butadiene latex, carboxylated styrene-butadiene, and carboxylated nitrile butadiene latex; the aqueous adhesive is an aqueous solution of phenolic resin or a mixed aqueous solution of blocked isocyanate, epoxy resin, and aqueous imidazole curing agent.

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