A hot melt tire with a built-in silver wire conductive beam and a preparation method thereof

Abstract

This invention belongs to the field of materials technology, specifically relating to a thermoplastic tire with an embedded silver wire conductive bundle and its preparation method. This thermoplastic tire includes a tread compound, a belt layer, a tire body, and a bead. A polymeric reactive flame retardant is added to the tread compound, which can cross-link and polymerize with the rubber matrix, thereby increasing the cross-linking density of the rubber molecular chains. This inhibits the movement of molecular chains under high-temperature conditions, improving the high-temperature resistance of the rubber. Simultaneously, the presence of rigid rings makes the rubber molecular chains more stable, further enhancing the high-temperature resistance of the rubber. Furthermore, the polymeric reactive flame retardant contains abundant phosphorus and sulfur elements, which can act as an acid source, promoting the formation of a dense carbon layer in the tread compound during combustion, effectively preventing further combustion. Therefore, by adding the polymeric reactive flame retardant prepared according to this invention, the high-temperature resistance and flame retardant properties of the tread compound can be significantly enhanced.

Description

Technical Field

[0001] This invention belongs to the field of materials technology, specifically relating to a hot-melt tire with an embedded silver wire conductive bundle and its preparation method. Background Technology

[0002] Traditional tires generate significant heat during high-speed driving, rapid acceleration, hard braking, or cornering. As temperatures rise, the rubber material in ordinary tires is prone to thermal aging, decreased grip, and accelerated wear. To address grip reduction at high temperatures, the industry has introduced the concept of slick tires. These tires utilize a special formula to achieve a semi-molten state in the tread at a certain temperature, resulting in a higher adhesion coefficient with the road surface and significantly improving grip limits.

[0003] Currently, slick tires are widely used in various applications, including automobile tires, truck and bus tires, engineering tires, motorcycle tires, electric vehicle tires, bicycle tires, scooter tires, and ATV tires. As a new type of functional tire, the core structure of slick tires integrates conductive bundles within the tire matrix to solve the problem of static electricity accumulation caused by the insulation of traditional rubber tires, thereby improving vehicle driving safety. In existing technologies, a built-in silver wire conductive bundle is typically used as the conductive path, and a hot melt adhesive layer is used to bond and fix the conductive bundle to the tire matrix, ensuring the positional stability and electrical contact reliability of the conductive structure under dynamic loads.

[0004] However, practical applications show that the hot melt adhesive layer used in current hot melt tires still has significant performance deficiencies, mainly in terms of high-temperature resistance and flame retardancy. Firstly, under high-speed driving or heavy-load conditions, the temperature inside the tire can rise above 100°C, and even higher in some areas. Conventional hot melt adhesives have relatively low softening and thermal decomposition temperatures, making them prone to softening, flowing, or a sharp drop in bond strength at high temperatures. This can lead to displacement, detachment, or breakage of the conductive strands, causing the conductive pathways to fail and affecting static electricity discharge. Secondly, tires may encounter external fire sources or abnormal frictional heat during operation. Ordinary hot melt adhesives lack sufficient flame retardancy and are prone to ignition and spread when heated, not only reducing the tire's structural integrity but also potentially increasing the risk of fire. This problem is particularly prominent in high-safety-requirement applications such as mining and chemical transportation.

[0005] Therefore, developing a hot melt adhesive layer that combines excellent high-temperature resistance and flame retardancy, and based on this, proposing a hot melt tire with a reliable structure and feasible process and its preparation method with built-in silver wire conductive bundle, has important engineering application value and market prospects. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a hot-melt tire with an embedded silver wire conductive bundle and its preparation method.

[0007] In a first aspect, the present invention provides a method for preparing a hot-melt tire with an embedded silver wire conductive bundle, comprising the following steps: The first step is to spin silver wire into nylon or polyester filament to form a silver wire anode conductive bundle; The second step is to twist, sizing, and weave the silver wire anode conductive bundle to form a curtain fabric with the silver wire anode conductive bundle inside. The third step is to apply conductive adhesive to the surface of the curtain fabric with built-in silver wire anode conductive bundles, and then cut the coated curtain fabric with built-in silver wire anode conductive bundles into adhesive curtain fabric that meets the specifications on the cutting machine. Step 4: First, attach two layers of cord fabric to the tire forming machine. These two layers of cord fabric participate in the reverse wrapping. Then attach two layers of cord fabric with built-in silver wire anode conductive bundles. This layer of cord fabric connects the inner side of the two steel wire rings. The two layers are pasted together at an alternating angle, so that the silver wire anode conductive bundles form a through-type interlaced three-dimensional network. Step 5: Assemble the tire bead, shape the bulge and turn it inside out, then apply the conductive bead protector to the top of the steel wire bead on both sides; Step 6: Attach the tread with conductive rubber strips to the cord fabric with built-in silver wire anode conductive bundles, then apply tread rubber to the other side of the tread. After assembly, vulcanize at a temperature of 160-180℃ and then shape it to obtain a hot melt tire.

[0008] As a preferred embodiment of the present invention, the tread compound comprises the following raw materials measured in parts by weight: Solution-polymerized styrene-butadiene rubber: 75-85 parts; Butadiene rubber: 15-25 parts; High-molecular reactive flame retardant: 2.5-6.5 parts; Silica: 30-40 parts; Silane coupling agent: 3-6 parts; Chlorinated paraffin oil: 5-15 parts; Anti-aging agent: 0.5-1 part; Sulfur: 0.5-1.5 parts; The tread compound is prepared by the following method: Step A: Weigh and prepare all raw materials according to their respective weight proportions; Step B: Add all raw materials to a high-speed mixer, control the speed to 80-100 rpm, and mechanically mix until homogeneous.

[0009] As a preferred embodiment of the present invention, the preparation method of the polymer reactive flame retardant includes the following steps: Step 1: Add 1,3-monoacrylate adamantane alcohol to tetrahydrofuran, purge with nitrogen, and mix thoroughly by mechanical stirring. Then, in an ice bath environment, add phosphoric acid dichloride derivative and acid-binding agent. After the addition is complete, remove from the ice bath, turn on the heater, and raise the temperature to 50-60℃. Stir continuously at this temperature for 6-9 hours, then stop heating, allow to cool naturally, and filter. After washing and drying, the filtrate is evaporated and concentrated. The product is collected and purified by column chromatography to obtain the polymerized monomer. Step 2: Add the polymerizing monomer and toluene to the nitrogen-filled reactor. After the addition is complete, start stirring and mix evenly. Then, add 2,5-dimethylmercapto-1,4-dithiane and the initiator. Adjust the temperature to 60-80℃ and continue stirring for 12-24 hours. Then, remove the nitrogen and evaporate the solvent. The crude product is washed and vacuum dried to obtain a polymeric reactive flame retardant.

[0010] As a preferred embodiment of the present invention, in step one, the phosphoryl dichloride derivative is any one of ethyl dichlorophosphate, methyl dichlorophosphate, or benzyl dichlorophosphate.

[0011] As a preferred embodiment of the present invention, in step one, the acid-binding agent is any one of triethylamine, pyridine, or N,N-diisopropylethylamine.

[0012] As a preferred embodiment of the present invention, in step one, the molar ratio of the 1,3-monoacrylate adamantane alcohol and the phosphoryl dichloride derivative is 1:0.5.

[0013] As a preferred embodiment of the present invention, in step two, the molar ratio of the polymeric monomer to 2,5-dimethylmercapto-1,4-dithiane is 1:0.95-0.98.

[0014] As a preferred embodiment of the present invention, in step two, the initiator is azobisisobutyronitrile or azobisisoheptanenitrile.

[0015] It should be noted that in the above technical solution, 1,3-monoacrylate adamantane alcohol and phosphoryl dichloride derivatives are first used as reactants. Under the action of an acid-binding agent, the active hydroxyl groups in their structures can react with P-Cl. By controlling the ratio of the two, an adamantane derivative containing two equivalent unsaturated alkenyl substituents in its structure can be obtained, i.e., a polymer monomer. Then, under the action of an initiator, the two equivalent unsaturated alkenyl substituents in its structure can undergo a continuous and uninterrupted click reaction with the two equivalent mercapto substituents in the structure of 2,5-dimethylmercapto-1,4-dithiane, thereby obtaining a polysulfide-type polymer flame retardant with an alternating linkage structure. By controlling the amount of polymer monomer and 2,5-dimethylmercapto-1,4-dithiane added, the polymer flame retardant can be end-capped with alkenyl groups and have reactive activity, i.e., a polymer reactive flame retardant.

[0016] As a preferred embodiment of the present invention, the silane coupling agent is 3-(methacryloyloxy)propyltrimethoxysilane or 3-(methacryloyloxy)propyltriethoxysilane; the antioxidant is antioxidant 4010 or antioxidant 4010NA.

[0017] In a second aspect, the present invention provides a thermoplastic tire with an embedded silver wire conductive bundle, which is prepared by the above-described method.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention prepares a polymer reactive flame retardant as an additive for tread rubber. During vulcanization, the terminal alkenyl groups in the polymer reactive flame retardant structure can crosslink and polymerize with the rubber matrix, thereby increasing the crosslink density of the rubber molecular chain. At the same time, the adamantane rigid ring and flame retardant elements in the polymer reactive flame retardant structure are introduced into the rubber molecular chain. First, the increased crosslink density can inhibit the movement of the molecular chain under high temperature conditions, thus improving the high temperature resistance of the rubber. Meanwhile, the presence of the rigid ring can make the rubber molecular chain have better stability under high temperature conditions, thereby further enhancing the high temperature resistance of the rubber. Second, the polymer reactive flame retardant structure contains abundant phosphorus and sulfur elements, which can act as an acid source to promote the rapid formation of a dense carbon layer in the tread rubber during combustion, effectively preventing further combustion. Therefore, by adding the polymer reactive flame retardant prepared in this invention, the high temperature resistance and flame retardant properties of the tread rubber can be significantly enhanced.

[0019] (2) The present invention has a built-in three-dimensional network of silver wire anode conductive bundle, which can realize the rapid release of static electricity in the tire without accumulation, discharge or interference. It can achieve the rapid discharge of static electricity in milliseconds. Moreover, the built-in method of this application will not affect the grip of the tread rubber, and is suitable for industrial production. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 Infrared analysis results for polymeric reactive flame retardants. Detailed Implementation

[0022] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0023] Preparation Example Preparation of polymeric reactive flame retardants: Step 1: Add 0.8g of 1,3-monoacrylate adamantane alcohol to tetrahydrofuran, purge with nitrogen, and mix thoroughly by mechanical stirring. Then, in an ice bath environment, add 0.29g of ethyl dichlorophosphate and 0.1g of triethylamine. After the addition is complete, remove from the ice bath, turn on the heater, raise the temperature to 5°C, and continue stirring at this temperature for 8 hours. Stop heating, allow to cool naturally, and filter. After washing and drying, evaporate and concentrate the filtrate, collect the product, and perform column chromatography purification to obtain the polymerized monomer. Step 2: Add 1.5g of polymeric monomer and toluene to a nitrogen-filled reactor. After the addition is complete, start stirring and mix thoroughly. Then, add 0.58g of 2,5-dimethylmercapto-1,4-dithiane and 0.1g of azobisisobutyronitrile. Adjust the temperature to 70℃ and continue stirring for 18 hours. Then, remove the nitrogen gas, evaporate and remove the solvent. The crude product is washed and vacuum dried to obtain a polymeric reactive flame retardant.

[0024] Figure 1 This is the infrared analysis test pattern of the polymer reactive flame retardant, where 3041 cm⁻¹... -1 The characteristic absorption peak appearing at 2800 cm⁻¹ is attributed to the characteristic absorption peak of CH in unsaturated alkenes. -1 ~3000cm -1 The characteristic absorption peak appearing at 1740 cm⁻¹ is attributed to the CH characteristic absorption peak of saturated aliphatic chains. -1 The characteristic absorption peak appearing at 1252 cm⁻¹ is attributed to the C=O characteristic absorption peak of the ester group. -1 The characteristic absorption peak appearing at 703 cm⁻¹ belongs to the P=O characteristic absorption peak. -1 The characteristic absorption peak appearing at this point belongs to the CS characteristic absorption peak, and no obvious thiol characteristic absorption peak was observed in the path. Example

[0025] This embodiment provides a tread compound, which comprises the following raw materials measured in parts by weight: Solution-polymerized styrene-butadiene rubber: 75 parts; Butadiene rubber: 15 parts; Polymer reactive flame retardant: 2.5 parts; Silica: 30 parts; Silane coupling agent: 3 parts; Chlorinated paraffin oil: 5 parts; Anti-aging agent: 0.5 parts; Vulcanizing agent: 0.5 parts; The tread compound is prepared by the following method: Step A: Weigh and prepare all raw materials according to their respective weight proportions; Step B: Add all raw materials to a high-speed mixer, control the speed to 100 rpm, and mechanically mix until homogeneous.

[0026] The preparation method of the polymer reactive flame retardant is shown in the preparation example; the silane coupling agent is 3-(methacryloyloxy)propyltrimethoxysilane; the antioxidant is antioxidant 4010NA; the following are the same. Example

[0027] This embodiment provides a tread compound, which comprises the following raw materials measured in parts by weight: Solution-polymerized styrene-butadiene rubber: 78 parts; Butadiene rubber: 20 parts; Polymer reactive flame retardant: 6 parts; Silica: 35 parts; Silane coupling agent: 4 parts; Chlorinated paraffin oil: 10 parts; Anti-aging agent: 0.6 parts; Vulcanizing agent: 1 part; The tread compound is prepared by the following method: Step A: Weigh and prepare all raw materials according to their respective weight proportions; Step B: Add all raw materials to a high-speed mixer, control the speed to 100 rpm, and mechanically mix until homogeneous. Example

[0028] Tread compound, said tread compound comprising the following raw materials measured in parts by weight: Solution-polymerized styrene-butadiene rubber: 85 parts; Butadiene rubber: 25 parts; Polymer reactive flame retardant: 6.5 parts; Silica: 40 parts; Silane coupling agent: 6 parts; Chlorinated paraffin oil: 15 parts; Anti-aging agent: 1 part; Vulcanizing agent: 1.5 parts; The tread compound is prepared by the following method: Step A: Weigh and prepare all raw materials according to their respective weight proportions; Step B: Add all raw materials to a high-speed mixer, control the speed to 100 rpm, and mechanically mix until homogeneous.

[0029] Comparative Example 1 The difference between this comparative example and Example 2 is that the polymeric reactive flame retardant is replaced with ethyl dichlorophosphate, otherwise they are the same.

[0030] Comparative Example 2 The difference between this comparative example and Example 2 is that the polymeric reactive flame retardant is removed; otherwise, they are the same.

[0031] The tread rubber provided in the above examples and comparative examples was vulcanized at a temperature of 180°C, and rubber strip samples that met the specifications were subjected to the following performance tests: (1) According to standard GB / T 2406.2-2009, the limiting oxygen index test is carried out to evaluate the flame retardant performance of the tread rubber. Generally speaking, the higher the limiting oxygen index, the better the flame retardant performance, and vice versa. (2) Take the same mass of tread rubber samples, place them in an oven, purge with nitrogen, control the heating rate to 5℃ / min, raise the temperature from room temperature to 600℃, record the temperature corresponding to the sample losing 5% of its weight, record it as the initial decomposition temperature, evaluate the high temperature resistance of the sample. Generally speaking, the higher the initial decomposition temperature, the better the high temperature resistance, and vice versa. The performance test data above are shown in Table 1.

[0032] Table 1 Performance Test Results Example 1 31.3 281.8 Example 2 31.7 282.1 Example 3 31.6 281.9 Comparative Example 1 28.1 271.1 Comparative Example 2 19.9 271.3 As can be seen from the above, the tread compound prepared in the embodiments of the present invention has good flame retardant properties and high temperature resistance. After replacing the polymer reactive flame retardant with the conventional small molecule flame retardant ethyl dichlorophosphate, it cannot synergize with the sulfur flame retardant element, resulting in a significant reduction in the flame retardant properties of the tread compound.

[0033] A hot-melt tire with an embedded silver wire conductive bundle is prepared using the tread rubber prepared in the embodiments of the present invention. The specific preparation method includes the following steps: The first step is to spin silver wires into nylon to form a silver wire anode conductive bundle; The second step is to twist, sizing, and weave the silver wire anode conductive bundle to form a curtain fabric with the silver wire anode conductive bundle inside. The third step is to apply conductive adhesive to the surface of the curtain fabric with built-in silver wire anode conductive bundles, and then cut the coated curtain fabric with built-in silver wire anode conductive bundles into adhesive curtain fabric that meets the specifications on the cutting machine. Step 4: First, attach two layers of cord fabric to the tire forming machine. These two layers of cord fabric participate in the reverse wrapping. Then attach two layers of cord fabric with built-in silver wire anode conductive bundles. This layer of cord fabric connects the inner side of the two steel wire rings. The two layers are pasted together at an alternating angle, so that the silver wire anode conductive bundles form a through-type interlaced three-dimensional network. Step 5: Assemble the tire bead, shape the bulge and turn it inside out, then apply the conductive bead protector to the top of the steel wire bead on both sides; Step 6: Attach the tread with conductive rubber strips to the top of the cord fabric with built-in silver wire anode conductive bundles, then apply tread rubber to the other side of the tread. After assembly, vulcanize at 180°C and then shape to obtain a hot melt tire.

[0034] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention, including the best mode, and also to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A method for preparing a hot-melt tire with an embedded silver wire conductive bundle, characterized in that, Includes the following steps: The first step is to spin silver wire into nylon or polyester filament to form a silver wire anode conductive bundle; The second step is to twist, sizing, and weave the silver wire anode conductive bundle to form a curtain fabric with the silver wire anode conductive bundle inside. The third step is to apply conductive adhesive to the surface of the curtain fabric with built-in silver wire anode conductive bundles, and then cut the coated curtain fabric with built-in silver wire anode conductive bundles into adhesive curtain fabric that meets the specifications on the cutting machine. Step 4: First, attach two layers of cord fabric to the tire forming machine. These two layers of cord fabric participate in the reverse wrapping. Then attach two layers of cord fabric with built-in silver wire anode conductive bundles. This layer of cord fabric connects the inner side of the two steel wire rings. The two layers are pasted together at an alternating angle, so that the silver wire anode conductive bundles form a through-type interlaced three-dimensional network. Step 5: Assemble the tire bead, shape the bulge and turn it inside out, then apply the conductive bead protector to the top of the steel wire bead on both sides; Step 6: Attach the tread with conductive rubber strips to the cord fabric with built-in silver wire anode conductive bundles, then apply tread rubber to the other side of the tread. After assembly, vulcanize at a temperature of 160-180℃ and then shape it to obtain a hot melt tire.

2. The method for preparing a hot-melt tire with an embedded silver wire conductive bundle according to claim 1, wherein the tread rubber comprises the following raw materials measured in parts by weight: Solution-polymerized styrene-butadiene rubber: 75-85 parts; Butadiene rubber: 15-25 parts; High-molecular reactive flame retardant: 2.5-6.5 parts; Silica: 30-40 parts; Silane coupling agent: 3-6 parts; Chlorinated paraffin oil: 5-15 parts; Anti-aging agent: 0.5-1 part; Sulfur: 0.5-1.5 parts; The tread compound is prepared by the following method: Step A: Weigh and prepare all raw materials according to their respective weight proportions; Step B: Add all raw materials to a high-speed mixer, control the speed to 80-100 rpm, and mechanically mix until homogeneous.

3. A method of producing a hot melt tire according to claim 2, characterized in that, The preparation method of the polymer reactive flame retardant includes the following steps: Step 1: Add 1,3-monoacrylate adamantane alcohol to tetrahydrofuran, purge with nitrogen, and mix thoroughly by mechanical stirring. Then, in an ice bath environment, add phosphoric acid dichloride derivative and acid-binding agent. After the addition is complete, remove from the ice bath, turn on the heater, and raise the temperature to 50-60℃. Stir continuously at this temperature for 6-9 hours, then stop heating, allow to cool naturally, and filter. After washing and drying, the filtrate is evaporated and concentrated. The product is collected and purified by column chromatography to obtain the polymerized monomer. Step 2: Add the polymerizing monomer and toluene to the nitrogen-filled reactor. After the addition is complete, start stirring and mix evenly. Then, add 2,5-dimethylmercapto-1,4-dithiane and the initiator. Adjust the temperature to 60-80℃ and continue stirring for 12-24 hours. Then, remove the nitrogen and evaporate the solvent. The crude product is washed and vacuum dried to obtain a polymeric reactive flame retardant.

4. A method of producing a hot melt tire according to claim 3, characterized in that, In step one, the phosphoryl dichloride derivative is any one of ethyl dichlorophosphate, methyl dichlorophosphate, or benzyl dichlorophosphate.

5. A method of preparing a hot melt tire according to claim 3, characterized in that, In step one, the acid-binding agent is any one of triethylamine, pyridine, or N,N-diisopropylethylamine.

6. A method of preparing a hot melt tire according to claim 3, characterized in that, In step one, the molar ratio of the 1,3-monoacrylate adamantane alcohol and the phosphoryl dichloride derivative is 1:0.

5.

7. A method of preparing a hot melt tire according to claim 3, characterized in that, In step two, the molar ratio of the polymer monomer to 2,5-dimethylmercapto-1,4-dithiane is 1:0.95-0.

98.

8. A method of preparing a hot melt tire according to claim 3, characterized in that, In step two, the initiator is azobisisobutyronitrile or azobisisoheptanenitrile.

9. A method of preparing a hot melt tire according to claim 2, characterized in that, The silane coupling agent is 3-(methacryloyloxy)propyltrimethoxysilane or 3-(methacryloyloxy)propyltriethoxysilane; the antioxidant is antioxidant 4010 or antioxidant 4010NA.

10. A hot melt tire with a built-in silver wire conductive bundle, characterized in that, It is prepared by the preparation method described in any one of claims 1-9.

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