Solid tire for automatic guided vehicle (AGV) and method for manufacturing the same

Abstract

The application discloses a solid tire for an automatic guided vehicle (AGV) and a preparation method thereof, and relates to the field of polyurethane tires. The solid tire comprises the following raw materials in parts by weight: polytetrahydrofuran ether glycol 100-110 parts, antioxidant 0.15-0.25 parts, light stabilizer 0.05-0.07 parts, hydrolysis-resistant agent 1-2 parts, diphenyl methane-4,4'-diisocyanate 20-30 parts, cross-linking modifier 1-3 parts, 1,4-butanediol 8-15 parts, dibutyltin dilaurate 0.06-0.08 parts and heat-conducting filler 10-20 parts. Through the synergistic effect of the cross-linking modifier and the heat-conducting filler of modified boron nitride, the wear resistance, mechanical properties, heat-aging resistance, oil resistance and heat-conducting performance of the solid tire are improved, and the material is endowed with excellent self-repairing performance.

Description

Technical Field

[0001] This invention relates to the field of polyurethane tire technology, specifically to a solid tire for an automated guided vehicle (AGV) and its manufacturing method. Background Technology

[0002] Automated Guided Vehicles (AGVs), as core equipment in modern logistics and intelligent manufacturing, rely heavily on tire performance for operational reliability and efficiency. Solid tires for AGVs must meet stringent requirements such as high load capacity, frequent starts and stops, long-term continuous operation, and complex terrain environments. Polyurethane, due to its excellent wear resistance, high load-bearing capacity, good elasticity, and designability, has become an ideal matrix material for AGV solid tires.

[0003] However, existing solid tire materials still have significant shortcomings in overall performance. While traditional polyurethane solid tires have good wear resistance and load-bearing capacity, the heat generated by rolling friction is difficult to dissipate quickly during long-term use, leading to a continuous increase in the internal temperature of the tire, accelerating material thermal aging, and even melting failure. When there are sharp objects such as metal shavings and glass shards on the factory floor, the tires are easily damaged, and the damage cannot be repaired, requiring frequent replacement. When in contact with industrial media such as lubricating oil and cutting fluid, they are prone to swelling and softening, leading to dimensional instability and a decline in mechanical properties. Under continuous heavy loads, the tires are prone to permanent flattening, affecting the AGV chassis height and navigation positioning accuracy.

[0004] To address the aforementioned issues, existing technologies have proposed various improvement solutions. For example, thermal conductivity and heat dissipation can be improved by physically blending thermally conductive fillers such as alumina, boron nitride, and graphene into the polyurethane matrix; chemical resistance can be improved by adding oil-resistant additives or introducing oleophobic groups. However, while these improvement solutions address individual problems, they often introduce new technical defects. Although physically blended thermally conductive fillers can improve thermal conductivity, ordinary fillers have poor interfacial compatibility with the polyurethane matrix, easily leading to agglomeration and localized stress concentration, which weakens the tensile strength and tear resistance of the material. Furthermore, the rigidity of inorganic fillers further reduces the material's resilience and toughness. While adding oil-resistant additives or oleophobic groups can improve oil resistance, they often have poor compatibility with the hard segments of polyurethane, causing microphase separation and affecting the material's mechanical uniformity and long-term stability.

[0005] Therefore, there is an urgent need to develop a solid tire for automated guided vehicles (AGVs) that can achieve a synergistic balance between thermal conductivity, resistance to compression set, chemical resistance, and overall mechanical properties. Summary of the Invention

[0006] To address the shortcomings mentioned in the background art, the present invention aims to provide a solid tire for an automated guided vehicle (AGV) and its preparation method. Through the synergistic effect of a crosslinking modifier and a thermally conductive filler modified with boron nitride, the wear resistance, mechanical properties, heat aging resistance, oil resistance, and thermal conductivity of the material are improved, and the material is endowed with excellent self-healing properties.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A solid tire for an automated guided vehicle (AGV) is characterized by comprising the following raw materials in parts by weight: 100-110 parts of polytetrahydrofuran ether diol, 0.15-0.25 parts of antioxidant, 0.05-0.07 parts of light stabilizer, 1-2 parts of anti-hydrolysis agent, 20-30 parts of diphenylmethane-4,4'-diisocyanate, 1-3 parts of crosslinking modifier, 8-15 parts of 1,4-butanediol, 0.06-0.08 parts of dibutyltin dilaurate, and 10-20 parts of thermally conductive filler;

[0009] The crosslinking modifier is prepared by oxidizing a heat-resistant precursor obtained by the thiol-olefin click reaction of haloalkyl thiols and 3-vinyl-1,4-pentadiene with hydrogen peroxide to obtain a heat-resistant intermediate, and then preparing it by nucleophilic substitution reaction of the heat-resistant intermediate with aminoethyl-disulfide-ethanol; the thermally conductive filler is prepared by Michael addition reaction of perfluorobutylethylene and silane coupling agent to obtain a modified silane coupling agent, while hexagonal boron nitride powder is exfoliated and hydroxylated, and then grafted onto boron nitride using the modified silane coupling agent.

[0010] More preferably, the antioxidant is antioxidant 1145 or antioxidant 1076.

[0011] More preferably, the light stabilizer is UV-531 or UV-P.

[0012] More preferably, the anti-hydrolysis agent is UN-025 or UN-03.

[0013] More preferably, the molecular weight of polytetrahydrofuran ether diol is 1000~2000.

[0014] More preferably, the method for preparing the crosslinking modifier includes the following steps:

[0015] S1. Add haloalkylthiols, 3-vinyl-1,4-pentadiene and deionized water to a reaction vessel and stir the reaction at room temperature for 6-10 h. After the reaction is completed, remove the solvent by rotary evaporation of the reaction solution, pour the mixture into petroleum ether, filter the precipitated solid and retain the solid, and then dry the solid to obtain the heat-resistant precursor.

[0016] S2. Add the heat-resistant precursor, hydrogen peroxide, sodium tungstate and acetonitrile to the reactor, heat to 25~30℃, stir for 6~8h and then cool to room temperature, add saturated sodium bicarbonate to adjust the pH to 7~8, extract with ethyl acetate, combine the organic phases and dry with anhydrous sodium sulfate, and obtain the heat-resistant intermediate by rotary evaporation.

[0017] S3. Add the heat-resistant intermediate, aminoethyl-disulfide-ethanol, triethylamine and N,N-dimethylformamide to the reactor and stir the reaction at 60~70℃ for 6~10h. After the reaction is completed, cool to room temperature and remove the solvent by rotary evaporation. Slowly drop the reaction solution into ice-cold deionized water to precipitate the product, and then wash it with diethyl ether after filtration to obtain the crosslinking modifier.

[0018] More preferably, in step S1, the haloalkylthiol is 2-chloroethanethiol, 3-chloro-1-propanethiol, or 3-bromo-1-propanethiol.

[0019] More preferably, in step S1, the mass ratio of haloalkylthiol to 3-vinyl-1,4-pentadiene is 0.8~2.4:0.2~0.6.

[0020] More preferably, the mass fraction of hydrogen peroxide in step S2 is 30-40%.

[0021] More preferably, the addition ratio of heat-resistant precursor, hydrogen peroxide and sodium tungstate in step S2 is 0.7~2.1g: 2~6mL: 0.15~0.45g.

[0022] More preferably, in step S3, the mass ratio of the heat-resistant intermediate, aminoethyl-disulfide-ethanol, and triethylamine is 0.7~2.1:0.6~1.8:0.5~1.5.

[0023] More preferably, the method for preparing the thermally conductive filler includes the following steps:

[0024] (1) Perfluorobutylethylene, lithium hydroxide and isopropanol are placed in a reactor, and silane coupling agent is added under nitrogen atmosphere. The mixture is stirred at room temperature for 3-4 hours. After the reaction is completed, the solvent is removed by rotary evaporation and then dried to obtain the modified silane coupling agent.

[0025] (2) Take hexagonal boron nitride powder and disperse it in a mixture of isopropanol and deionized water. Sonicate for 1-2 hours, and then use an ultrasonic cleaner to ultrasonically peel off the mixture for 10-12 hours to obtain peeled boron nitride nanosheets.

[0026] (3) Centrifuge the stripped boron nitride nanosheets at 4000-5000 rpm for 30-40 min, vacuum filter the supernatant obtained after centrifugation, and then vacuum dry at 100-110℃ for 10-12 h to obtain hydroxylated boron nitride nanoparticles.

[0027] (4) Hydroxylated boron nitride nanoparticles were added to a mixture of ethanol and deionized water and ultrasonically dispersed for 1-2 hours. Then, modified silane coupling agent was added and stirred and refluxed in an oil bath at 100-110°C for 18-24 hours to obtain thermally conductive filler.

[0028] More preferably, the silane coupling agent in step (1) is KH-550 or KH-540.

[0029] More preferably, the mass ratio of perfluorobutylethylene, lithium hydroxide and silane coupling agent in step (1) is 1~1.6:0.1~0.16:0.9~1.5.

[0030] More preferably, in step (2), the volume ratio of isopropanol to deionized water in the mixture is 1~3:1.

[0031] More preferably, the volume ratio of ethanol to deionized water in the mixture in step (4) is 2~4:1.

[0032] More preferably, the mass ratio of hexagonal boron nitride powder in step (2) to modified silane coupling agent in step (4) is 15~30:1.5~2.5.

[0033] A method for manufacturing solid tires for automated guided vehicles (AGVs) includes the following steps:

[0034] Polytetrahydrofuran ether glycol, antioxidant, light stabilizer, and anti-hydrolysis agent were added to a reactor and vacuum dried at 100-120℃ for 1.5-2 hours. After cooling to 60-65℃, diphenylmethane-4,4'-diisocyanate was added, and the temperature was raised to 70-80℃. The mixture was stirred for 2-3 hours. Then, a mixture of crosslinking modifier, 1,4-butanediol, dibutyltin dilaurate, and thermally conductive filler was added and rapidly mixed until homogeneous. Degas at 0.085 MPa for 2-3 minutes, inject into a mold preheated to 80-100℃, and hold under pressure of 5-10 MPa at 100-110℃ for 30-60 minutes. After the material has initially solidified and shaped, open the mold and remove the material. Place the demolded tire in an oven at 70-80℃ for 2-4 hours to cure, then mature at 100-110℃ for 1-2 hours, and finally place at room temperature for 5-7 days to obtain a solid tire for an automated guided vehicle (AGV).

[0035] The beneficial effects of this invention are:

[0036] The multifunctional groups in the crosslinking modifier of this invention construct a high-density three-dimensional network, forming a dual anti-deformation mechanism with the reinforcing effect of modified boron nitride. The boron nitride thermally conductive filler, modified with an amino-containing modified silane coupling agent, improves compatibility with the polyurethane matrix, achieving excellent dispersion and interfacial bonding, and efficiently transferring loads to the filler. When applied to AGV solid tires, it can significantly suppress permanent deformation and creep under heavy loads, maintain tire dimensional stability, and ensure the long-term operational reliability of automated logistics systems.

[0037] The boron nitride thermally conductive filler modified with the modified silane coupling agent of this invention forms a three-dimensional thermally conductive network within a polyurethane matrix. The amino groups chemically bond with the isocyanate groups, preventing filler agglomeration and significantly improving the thermal conductivity of the composite material. The stress relaxation provided by the crosslinking points of the crosslinking network constructed by the crosslinking modifier avoids localized stress concentration caused by filler rigidity. Simultaneously, the thermal stability imparted by the sulfone groups ensures the material's durability at high temperatures. This allows the thermally conductive pathways to rapidly transfer the heat generated by rolling friction to the tire surface for dissipation, reducing internal temperature rise and preventing material softening, accelerated aging, or even melting failure due to overheating. This greatly improves the safe operating life of the tire under continuous high-load conditions.

[0038] Furthermore, the chemical inertness of the sulfone groups in the crosslinking modifier synergistically with the hydrophobic and oleophobic properties of the modified boron nitride thermally conductive filler, giving the material excellent chemical corrosion resistance. The sulfone groups are resistant to most organic solvents, acids, alkalis, and oils; the perfluoroalkyl chains on the boron nitride surface prevent solvent and oil penetration, and the high-density crosslinking network further inhibits solvent diffusion. When applied to AGV tires in factory environments, they do not swell, soften, or experience mechanical degradation when exposed to media such as lubricating oil, cutting fluid, and cleaning agents. Even in oil-water mixed environments, the tire's size, hardness, and friction remain stable, preventing failure and ensuring long-term safe operation of equipment in complex industrial scenarios.

[0039] The disulfide bonds in the crosslinking modifier of this invention can undergo reversible breakage and recombination under stress, temperature, and catalytic conditions, endowing the polyurethane network with dynamic self-healing capabilities. The addition of modified boron nitride thermally conductive filler significantly enhances the puncture resistance and crack propagation resistance of the composite material. The amino groups in the modified silane coupling agent enable boron nitride to form a strong chemical bond with the polyurethane matrix, and the filler acts as a physical reinforcement point, effectively hindering the rapid propagation of cracks under stress. This combination of chemical self-healing and physical reinforcement allows AGV tires to withstand repeated mechanical stress changes from the outside during operation, significantly reducing equipment downtime and maintenance costs. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1 A solid tire for an automated guided vehicle (AGV) comprises the following raw materials in parts by weight: 100 parts of polytetrahydrofuran ether glycol with a molecular weight of 2000, 0.15 parts of antioxidant 1145, 0.05 parts of light stabilizer UV-531, 1 part of anti-hydrolysis agent UN-025, 20 parts of diphenylmethane-4,4'-diisocyanate, 1 part of crosslinking modifier, 8 parts of 1,4-butanediol, 0.06 parts of dibutyltin dilaurate, and 10 parts of thermally conductive filler;

[0042] The preparation method of the crosslinking modifier includes the following steps:

[0043] S1. Add 0.8g of 3-chloro-1-propanethiol, 0.2g of 3-vinyl-1,4-pentadiene and 15mL of deionized water to a reaction vessel and stir the reaction at room temperature for 6h. After the reaction is completed, remove the solvent by rotary evaporation of the reaction solution, pour the mixture into petroleum ether, filter the precipitated solid and retain the solid, and then dry the solid to obtain the heat-resistant precursor.

[0044] S2. Add 0.7g of heat-resistant precursor, 2mL of 30% hydrogen peroxide, 0.15g of sodium tungstate and 20mL of acetonitrile to the reactor, heat to 25℃, stir for 8h and then cool to room temperature. Add saturated sodium bicarbonate to adjust the pH to 7, extract with ethyl acetate, combine the organic phases and dry with anhydrous sodium sulfate. After rotary evaporation, the heat-resistant intermediate is obtained.

[0045] S3. Add 0.7g of heat-resistant intermediate, 0.6g of aminoethyl-disulfide-ethanol, 0.55g of triethylamine and 20mL of N,N-dimethylformamide to the reactor and stir the reaction at 60℃ for 10h. After the reaction is completed, cool to room temperature and remove the solvent by rotary evaporation. Slowly drop the reaction solution into ice-cold deionized water to precipitate the product, and then wash it with diethyl ether after filtration to obtain the crosslinking modifier.

[0046] The preparation method of thermally conductive filler includes the following steps:

[0047] (1) 1g of perfluorobutylethylene, 0.1g of lithium hydroxide and 25mL of isopropanol were placed in a reactor, and 0.9g of silane coupling agent KH-550 was added under a nitrogen atmosphere. The mixture was stirred at room temperature for 3h. After the reaction was completed, the solvent was removed by rotary evaporation and then dried to obtain the modified silane coupling agent.

[0048] (2) Take 15g of hexagonal boron nitride powder and disperse it in a mixture of 1500mL isopropanol and 1500mL deionized water. Sonicate for 1h to make the powder better dispersed in the isopropanol aqueous solution. Then use an ultrasonic cleaner to ultrasonically peel the mixed solution for 10h to completely peel off the boron nitride nanosheets. Centrifuge the peeled boron nitride nanosheets at 4000rpm for 40min. Vacuum filter the supernatant obtained after centrifugation. Then vacuum dry at 100℃ for 12h to obtain hydroxylated boron nitride nanoparticles.

[0049] (3) Hydroxylated boron nitride nanoparticles were added to a mixture of 1500 mL ethanol and 500 mL deionized water and ultrasonically dispersed for 1 h. Then, 1.5 g of modified silane coupling agent was added and stirred and refluxed in an oil bath at 100 °C for 18 h to obtain thermally conductive filler.

[0050] A method for manufacturing solid tires for automated guided vehicles (AGVs) includes the following steps:

[0051] 100g of polytetrahydrofuran ether diol with a molecular weight of 2000, 0.15g of antioxidant 1145, 0.05g of light stabilizer UV-531, and 1g of hydrolysis inhibitor UN-025 were added to a reactor. The mixture was vacuum dried at 110℃ for 2 hours. After cooling to 60℃, 20g of diphenylmethane-4,4'-diisocyanate was added. The temperature was raised to 70℃, and the mixture was stirred for 3 hours. Then, 1g of crosslinking modifier, 8g of 1,4-butanediol, and 0.06g of bismuth subtilis were added. The mixture of dibutyltin cinnamate and 10g of thermally conductive filler was rapidly and evenly mixed, degassed at -0.095MPa for 3min, and injected into a mold preheated to 100℃. The mixture was then held at 110℃ for 45min under a pressure of 10MPa. After the material was initially cured and shaped, the mold was opened and the tire was removed. The demolded tire was placed in a 75℃ oven for curing for 4h, then cured at 110℃ for 2h, and finally placed at room temperature for 7 days to obtain a solid tire for an automated guided vehicle (AGV).

[0052] Example 2 A solid tire for an automated guided vehicle (AGV) comprises the following raw materials in parts by weight: 110 parts of polytetrahydrofuran ether glycol with a molecular weight of 2000, 0.25 parts of antioxidant 1076, 0.07 parts of light stabilizer UV-P, 2 parts of anti-hydrolysis agent UN-03, 30 parts of diphenylmethane-4,4'-diisocyanate, 3 parts of crosslinking modifier, 15 parts of 1,4-butanediol, 0.08 parts of dibutyltin dilaurate, and 20 parts of thermally conductive filler;

[0053] The preparation method of the crosslinking modifier includes the following steps:

[0054] S1. Add 2.4g of 3-bromo-1-propanethiol, 0.6g of 3-vinyl-1,4-pentadiene and 15mL of deionized water to a reaction vessel and stir the mixture at room temperature for 10h. After the reaction is complete, remove the solvent by rotary evaporation of the reaction solution, pour the mixture into petroleum ether, filter the precipitated solid and retain the solid, and then dry the solid to obtain the heat-resistant precursor.

[0055] S2. Add 2.1g of heat-resistant precursor, 6mL of 40% hydrogen peroxide, 0.45g of sodium tungstate and 20mL of acetonitrile to the reactor, heat to 30℃, stir for 6h and then cool to room temperature. Add saturated sodium bicarbonate to adjust the pH to 7, extract with ethyl acetate, combine the organic phases and dry with anhydrous sodium sulfate. After rotary evaporation, the heat-resistant intermediate is obtained.

[0056] S3. Add 2.1g of heat-resistant intermediate, 1.8g of aminoethyl-disulfide-ethanol, 1.5g of triethylamine and 20mL of N,N-dimethylformamide to the reactor and stir the reaction at 70℃ for 10h. After the reaction is completed, cool to room temperature and remove the solvent by rotary evaporation. Slowly drop the reaction solution into ice-cold deionized water to precipitate the product, and then wash it with diethyl ether after filtration to obtain the crosslinking modifier.

[0057] The preparation method of thermally conductive filler includes the following steps:

[0058] (1) 1.6g of perfluorobutylethylene, 0.16g of lithium hydroxide and 25mL of isopropanol were placed in a reactor, and 1.5g of silane coupling agent KH-540 was added under a nitrogen atmosphere. The mixture was stirred at room temperature for 4h. After the reaction was completed, the solvent was removed by rotary evaporation and then dried to obtain the modified silane coupling agent.

[0059] (2) Take 30g of hexagonal boron nitride powder and disperse it in a mixture of 1500mL isopropanol and 1500mL deionized water. Sonicate for 2h to make the powder better dispersed in the isopropanol aqueous solution. Then use an ultrasonic cleaner to ultrasonically peel the mixed solution for 12h to completely peel off the boron nitride nanosheets. Centrifuge the peeled boron nitride nanosheets at 5000rpm for 30min. Vacuum filter the supernatant obtained after centrifugation. Then vacuum dry at 100℃ for 12h to obtain hydroxylated boron nitride nanoparticles.

[0060] (3) Hydroxylated boron nitride nanoparticles were added to a mixture of 1500 mL ethanol and 500 mL deionized water and ultrasonically dispersed for 1 h. Then, 2.5 g of modified silane coupling agent was added and stirred and refluxed in an oil bath at 110 °C for 18-24 h to obtain thermally conductive filler.

[0061] A method for manufacturing solid tires for automated guided vehicles (AGVs) includes the following steps:

[0062] 110g of polytetrahydrofuran ether diol with a molecular weight of 2000, 0.25g of antioxidant 1076, 0.07g of light stabilizer UV-P, and 2g of hydrolysis inhibitor UN-03 were added to a reactor. The mixture was vacuum dried at 120℃ for 1.5h, then cooled to 65℃. 30g of diphenylmethane-4,4-'-diisocyanate was added, and the temperature was raised to 80℃. The mixture was stirred for 3h. Then, 3g of crosslinking modifier, 15g of 1,4-butanediol, and 0.08g of bismuth subtilis were added. The mixture of dibutyltin cinnamate and 20g of thermally conductive filler was rapidly and evenly mixed, degassed at -0.085MPa for 3min, and injected into a mold preheated to 100℃. The mixture was then held at 110℃ for 60min under a pressure of 10MPa. After the material was initially cured and shaped, the mold was opened and the tire was removed. The demolded tire was placed in an 80℃ oven for curing for 4h, then aged at 110℃ for 1h, and finally placed at room temperature for 7 days to obtain a solid tire for an automated guided vehicle (AGV).

[0063] Example 3 A solid tire for an automated guided vehicle (AGV) comprises the following raw materials in parts by weight: 105 parts of polytetrahydrofuran ether diol with a molecular weight of 2000, 0.2 parts of antioxidant 1076, 0.06 parts of light stabilizer UV-531, 1.5 parts of hydrolysis resistant agent UN-025, 25 parts of diphenylmethane-4,4'-diisocyanate, 2 parts of crosslinking modifier, 11 parts of 1,4-butanediol, 0.07 parts of dibutyltin dilaurate, and 15 parts of thermally conductive filler;

[0064] The preparation method of the crosslinking modifier includes the following steps:

[0065] S1. Add 1.6g of 3-chloro-1-propanethiol, 0.4g of 3-vinyl-1,4-pentadiene and 15mL of deionized water to a reaction vessel and stir the mixture at room temperature for 8h. After the reaction is complete, remove the solvent by rotary evaporation and pour the mixture into petroleum ether. After the solid precipitates, filter the mixture and retain the solid. Then dry the solid to obtain the heat-resistant precursor.

[0066] S2. Add 1.4g of heat-resistant precursor, 4mL of 30% hydrogen peroxide, 0.3g of sodium tungstate and 20mL of acetonitrile to the reactor, heat to 25℃, stir and react for 7h, cool to room temperature, add saturated sodium bicarbonate to adjust pH to 7, extract with ethyl acetate, combine the organic phases and dry with anhydrous sodium sulfate, and obtain the heat-resistant intermediate by rotary evaporation.

[0067] S3. Add 1.4g of heat-resistant intermediate, 1.2g of aminoethyl-disulfide-ethanol, 1.0g of triethylamine and 20mL of N,N-dimethylformamide to the reactor and stir the reaction at 60℃ for 8h. After the reaction is completed, cool to room temperature and remove the solvent by rotary evaporation. Slowly drop the reaction solution into ice-cold deionized water to precipitate the product, and then wash it with diethyl ether after filtration to obtain the crosslinking modifier.

[0068] The preparation method of thermally conductive filler includes the following steps:

[0069] (1) 1.3g of perfluorobutylethylene, 0.13g of lithium hydroxide and 25mL of isopropanol were placed in a reactor, and 1.2g of silane coupling agent KH-540 was added under a nitrogen atmosphere. The mixture was stirred at room temperature for 3.5h. After the reaction was completed, the solvent was removed by rotary evaporation and then dried to obtain the modified silane coupling agent.

[0070] (2) Take 20g of hexagonal boron nitride powder and disperse it in a mixture of 1500mL isopropanol and 1500mL deionized water. Sonicate for 2h, and then use an ultrasonic cleaner to ultrasonically peel the mixture for 12h to obtain peeled boron nitride nanosheets.

[0071] (3) The exfoliated boron nitride nanosheets were centrifuged at 4500 rpm for 40 min. The supernatant obtained after centrifugation was vacuum filtered and then vacuum dried at 100℃ for 12 h to obtain hydroxylated boron nitride nanoparticles.

[0072] (4) Hydroxylated boron nitride nanoparticles were added to a mixture of 1500 mL ethanol and 500 mL deionized water and ultrasonically dispersed for 2 h. Then 2.0 g modified silane coupling agent was added and stirred and refluxed in an oil bath at 100 °C for 20 h to obtain thermally conductive filler.

[0073] A method for manufacturing solid tires for automated guided vehicles (AGVs) includes the following steps:

[0074] 105g of polytetrahydrofuran ether diol with a molecular weight of 2000, 0.2g of antioxidant 1076, 0.06g of light stabilizer UV-531, and 1.5g of hydrolysis inhibitor UN-025 were added to a reactor. The mixture was vacuum dried at 110℃ for 2 hours. After cooling to 63℃, 25g of diphenylmethane-4,4-'-diisocyanate was added. The temperature was raised to 75℃, and the mixture was stirred for 2.5 hours. Then, 2g of crosslinking modifier and 11g of... A mixture of 1,4-butanediol, 0.07g dibutyltin dilaurate, and 15g thermally conductive filler was rapidly and evenly mixed, degassed at -0.090MPa for 2 minutes, and injected into a mold preheated to 90℃. The mixture was then held at 105℃ for 45 minutes under a pressure of 8MPa. After the material had initially solidified and set, the mold was opened and the tire was removed. The demolded tire was then placed in a 75℃ oven for curing for 3 hours, followed by aging at 105℃ for 1.5 hours, and finally left at room temperature for 6 days to obtain a solid tire for an automated guided vehicle (AGV).

[0075] Comparative Example 1: A solid tire for an automated guided vehicle (AGV) comprises the following raw materials in parts by weight: 105 parts of polytetrahydrofuran ether glycol with a molecular weight of 2000, 0.2 parts of antioxidant 1076, 0.06 parts of light stabilizer UV-531, 1.5 parts of hydrolysis resistant agent UN-025, 25 parts of diphenylmethane-4,4'-diisocyanate, 11 parts of 1,4-butanediol, 0.07 parts of dibutyltin dilaurate, and 15 parts of thermally conductive filler;

[0076] A method for manufacturing solid tires for automated guided vehicles (AGVs) includes the following steps:

[0077] 105g of polytetrahydrofuran ether diol with a molecular weight of 2000, 0.2g of antioxidant 1076, 0.06g of light stabilizer UV-531, and 1.5g of hydrolysis inhibitor UN-025 were added to a reactor. The mixture was vacuum dried at 110℃ for 2 hours. After cooling to 63℃, 25g of diphenylmethane-4,4-'-diisocyanate was added. The temperature was raised to 75℃, and the mixture was stirred for 2.5 hours. Then, 11g of... A mixture of 1,4-butanediol, 0.07g dibutyltin dilaurate, and 15g thermally conductive filler was rapidly and evenly mixed, degassed at -0.090MPa for 2 minutes, and injected into a mold preheated to 90℃. The mixture was then held at 105℃ for 45 minutes under a pressure of 8MPa. After the material had initially solidified and set, the mold was opened and the tire was removed. The demolded tire was then placed in a 75℃ oven for curing for 3 hours, followed by aging at 105℃ for 1.5 hours, and finally left at room temperature for 6 days to obtain a solid tire for an automated guided vehicle (AGV).

[0078] The difference between this invention and Example 3 is that no crosslinking modifier is added, and the preparation method of the thermally conductive filler and the rest of the preparation process are the same as in Example 3.

[0079] Comparative Example 2: A solid tire for an automated guided vehicle (AGV) comprises the following raw materials in parts by weight: 105 parts of polytetrahydrofuran ether glycol with a molecular weight of 2000, 0.2 parts of antioxidant 1076, 0.06 parts of light stabilizer UV-531, 1.5 parts of hydrolysis resistant agent UN-025, 25 parts of diphenylmethane-4,4'-diisocyanate, 2 parts of crosslinking modifier, 11 parts of 1,4-butanediol, 0.07 parts of dibutyltin dilaurate, and 15 parts of filler;

[0080] The method for preparing the filler includes the following steps:

[0081] (1) Take 20g of hexagonal boron nitride powder and disperse it in a mixture of 1500mL isopropanol and 1500mL deionized water. Sonicate for 1h, and then use an ultrasonic cleaner to ultrasonically peel the mixture for 12h to obtain peeled boron nitride nanosheets.

[0082] (2) The exfoliated boron nitride nanosheets were centrifuged at 4500 rpm for 40 min. The supernatant obtained after centrifugation was vacuum filtered and then vacuum dried at 100℃ for 12 h to obtain the filler.

[0083] A method for manufacturing solid tires for automated guided vehicles (AGVs) includes the following steps:

[0084] 105g of polytetrahydrofuran ether diol with a molecular weight of 2000, 0.2g of antioxidant 1076, 0.06g of light stabilizer UV-531, and 1.5g of hydrolysis inhibitor UN-025 were added to a reactor. The mixture was vacuum dried at 110℃ for 2 hours. After cooling to 63℃, 25g of diphenylmethane-4,4-'-diisocyanate was added. The temperature was raised to 75℃, and the mixture was stirred for 2.5 hours. Then, 2g of crosslinking modifier and 11g of... A mixture of 1,4-butanediol, 0.07g dibutyltin dilaurate, and 15g filler was rapidly and uniformly mixed. The mixture was degassed at -0.090MPa for 2 minutes and then injected into a mold preheated to 90℃. The mold was then pressed at 105℃ for 45 minutes under a pressure of 8MPa. After the material was initially cured and shaped, the mold was opened and the tire was removed. The demolded tire was then placed in a 75℃ oven for curing for 3 hours, followed by aging at 105℃ for 1.5 hours, and then left at room temperature for 6 days to obtain a solid tire for an automated guided vehicle (AGV).

[0085] The difference between this invention and Example 3 is that the thermally conductive filler is replaced with the filler prepared by the above preparation method, while the preparation method of the crosslinking modifier and the rest of the preparation process are the same as in Example 3.

[0086] Comparative Example 3: A solid tire for an automated guided vehicle (AGV) comprises the following raw materials in parts by weight: 105 parts of polytetrahydrofuran ether glycol with a molecular weight of 2000, 0.2 parts of antioxidant 1076, 0.06 parts of light stabilizer UV-531, 1.5 parts of hydrolysis resistant agent UN-025, 25 parts of diphenylmethane-4,4'-diisocyanate, 11 parts of 1,4-butanediol, 0.07 parts of dibutyltin dilaurate, and 15 parts of thermally conductive filler;

[0087] The method for preparing the filler includes the following steps:

[0088] (1) Take 20g of hexagonal boron nitride powder and disperse it in a mixture of 1500mL isopropanol and 1500mL deionized water. Sonicate for 1h, and then use an ultrasonic cleaner to ultrasonically peel the mixture for 12h to obtain peeled boron nitride nanosheets.

[0089] (2) The exfoliated boron nitride nanosheets were centrifuged at 4500 rpm for 40 min. The supernatant obtained after centrifugation was vacuum filtered and then vacuum dried at 100℃ for 12 h to obtain the filler.

[0090] A method for manufacturing solid tires for automated guided vehicles (AGVs) includes the following steps:

[0091] 105g of polytetrahydrofuran ether diol with a molecular weight of 2000, 0.2g of antioxidant 1076, 0.06g of light stabilizer UV-531, and 1.5g of hydrolysis inhibitor UN-025 were added to a reactor. The mixture was vacuum dried at 110℃ for 2 hours. After cooling to 63℃, 25g of diphenylmethane-4,4-'-diisocyanate was added. The temperature was raised to 75℃, and the mixture was stirred for 2.5 hours. Then, 11g of... A mixture of 1,4-butanediol, 0.07g dibutyltin dilaurate, and 15g filler was rapidly and uniformly mixed. The mixture was degassed at -0.090MPa for 2 minutes and then injected into a mold preheated to 90℃. The mold was then pressed at 105℃ for 45 minutes under a pressure of 8MPa. After the material was initially cured and shaped, the mold was opened and the tire was removed. The demolded tire was then placed in a 75℃ oven for curing for 3 hours, followed by aging at 105℃ for 1.5 hours, and then left at room temperature for 6 days to obtain a solid tire for an automated guided vehicle (AGV).

[0092] The difference between this invention and Example 3 is that the thermally conductive filler is replaced with the filler prepared by the above preparation method, and no crosslinking modifier is added; the rest of the preparation process is the same as in Example 3.

[0093] Performance testing

[0094] The Automated Guided Vehicles (AGVs) of Examples 1-3 and Comparative Examples 1-3 were fabricated using solid tires to create tire tread samples with dimensions of 60mm × 40mm × 12mm for performance testing.

[0095] (1) Mechanical property test: The Akron abrasion of each group of samples was tested according to GB / T 1689-2014, the tear strength of each group of samples was tested according to GB / T 529-2008, the tensile strength of each group of tires was tested according to GB / T 528-2009, the resilience of each group of samples was tested according to GB / T 1681-2009, and the compression set of each group of samples after compression at 25% compression rate and 70℃ for 24h was tested according to GB / T 7759.1-2015. The mechanical property test data are shown in Table 1.

[0096] Table 1: Statistical Table of Mechanical Property Test Data

[0097]

[0098] As shown in Table 1, the Akron wear resistance, tear strength, tensile strength, resilience, and compression set of Examples 1-3 are all superior to those of Comparative Examples 1-3. Among the comparative examples, Comparative Example 3 has the worst mechanical properties. This indicates that the synergistic effect of the crosslinking modifier and the thermally conductive filler modified boron nitride significantly improves the material's wear resistance, tear resistance, tensile properties, resilience, and dimensional stability under continuous load, enabling the solid tires of automated guided vehicles (AGVs) to adapt to their high-load working scenarios.

[0099] (2) Heat resistance, oil resistance and thermal conductivity test: The tensile strength retention rate of each group of samples after aging in a hot air aging chamber at 120℃±2℃ for 14 days was tested according to GB / T 3512-2014. The thermal conductivity of each group of samples was tested at 25℃ by making the samples into circular pieces with a diameter of 30mm and a thickness of 5mm according to GB / T 10297-2015. The volume change rate of each group of samples after immersion in IRM 902 oil at 70℃ for 72h was tested according to GB / T 1690-2010. The test data of heat resistance, oil resistance and thermal conductivity are shown in Table 2.

[0100] Table 2: Statistical Table of Test Data for Heat Resistance, Oil Resistance, and Thermal Conductivity

[0101]

[0102] As shown in Table 2, the tensile strength retention rate, thermal conductivity, and volume change rate after oil immersion of Examples 1-3 after heat aging are all better than those of Comparative Examples 1-3. Among the comparative examples, Comparative Example 3 has the worst performance. This indicates that the synergistic effect of the crosslinking modifier and the modified boron nitride thermally conductive filler significantly improves the heat aging resistance, oil resistance, and thermal conductivity of the material, enabling the solid tires of the automated guided vehicle (AGV) to operate safely for a long time under complex working conditions.

[0103] (3) Self-healing performance test: The samples in Examples 1-3 and Comparative Example 2 were tested. A cut was made in the middle of the sample to a depth of 50% of the thickness. The samples were then heat-healed at 80°C for 24 hours. The tensile strength recovery rate of each group of samples after repair was tested. The self-healing performance test data are shown in Table 3.

[0104] Table 3: Statistical Table of Self-Healing Performance Test Data

[0105]

[0106] As can be seen from Table 3, the samples in Examples 1-3 and Comparative Example 2 have a high tensile strength recovery rate, which indicates that the disulfide bonds in the crosslinking modifier can endow the material with excellent self-healing properties, enabling the solid tires of the automated guided vehicle (AGV) to withstand repeated mechanical stress changes brought about by external forces during operation.

[0107] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A solid tire for an automated guided vehicle (AGV), characterized by, The raw materials include the following parts by weight: 100-110 parts of polytetrahydrofuran ether diol, 0.15-0.25 parts of antioxidant, 0.05-0.07 parts of light stabilizer, 1-2 parts of anti-hydrolysis agent, 20-30 parts of diphenylmethane-4,4'-diisocyanate, 1-3 parts of crosslinking modifier, 8-15 parts of 1,4-butanediol, 0.06-0.08 parts of dibutyltin dilaurate, and 10-20 parts of thermally conductive filler; The crosslinking modifier is prepared by oxidizing a heat-resistant precursor obtained by the thiol-olefin click reaction of haloalkyl thiols and 3-vinyl-1,4-pentadiene with hydrogen peroxide to obtain a heat-resistant intermediate, and then preparing it by nucleophilic substitution reaction of the heat-resistant intermediate with aminoethyl-disulfide-ethanol; the thermally conductive filler is prepared by Michael addition reaction of perfluorobutylethylene and silane coupling agent to obtain a modified silane coupling agent, while hexagonal boron nitride powder is exfoliated and hydroxylated, and then grafted onto boron nitride using the modified silane coupling agent.

2. The solid tire for an automatic guided vehicle (AGV) according to claim 1, characterized by, The antioxidant is antioxidant 1145 or antioxidant 1076, the light stabilizer is UV-531 or UV-P, the anti-hydrolysis agent is UN-025 or UN-03, and the molecular weight of the polytetrahydrofuran ether diol is 1000~2000.

3. The solid tire for an automatic guided vehicle (AGV) according to claim 1, characterized by The preparation method of the crosslinking modifier includes the following steps: S1. Add haloalkylthiols, 3-vinyl-1,4-pentadiene and deionized water to a reaction vessel and stir the reaction at room temperature for 6-10 h. After the reaction is completed, remove the solvent by rotary evaporation of the reaction solution, pour the mixture into petroleum ether, filter the precipitated solid and retain the solid, and then dry the solid to obtain the heat-resistant precursor. S2. Add the heat-resistant precursor, hydrogen peroxide, sodium tungstate and acetonitrile to the reactor, heat to 25~30℃, stir for 6~8h and then cool to room temperature, add saturated sodium bicarbonate to adjust the pH to 7~8, extract with ethyl acetate, combine the organic phases and dry with anhydrous sodium sulfate, and obtain the heat-resistant intermediate by rotary evaporation. S3. Add the heat-resistant intermediate, aminoethyl-disulfide-ethanol, triethylamine and N,N-dimethylformamide to the reactor and stir the reaction at 60~70℃ for 6~10h. After the reaction is completed, cool to room temperature and remove the solvent by rotary evaporation. Slowly drop the reaction solution into ice-cold deionized water to precipitate the product, and then wash it with diethyl ether after filtration to obtain the crosslinking modifier.

4. The solid tire for an automated guided vehicle (AGV) according to claim 3, characterized by In step S1, the haloalkylthiol is 2-chloroethanethiol, 3-chloro-1-propanethiol, or 3-bromo-1-propanethiol, and the mass ratio of haloalkylthiol to 3-vinyl-1,4-pentadiene is 0.8~2.4:0.2~0.

6.

5. The solid tire for an automated guided vehicle (AGV) according to claim 3, characterized by In step S2, the mass fraction of hydrogen peroxide is 30-40%, and the addition ratio of heat-resistant precursor, hydrogen peroxide and sodium tungstate is 0.7-2.1g: 2-6mL: 0.15-0.45g.

6. The solid tire for an automated guided vehicle (AGV) according to claim 3, characterized by In step S3, the mass ratio of the heat-resistant intermediate, aminoethyl-disulfide-ethanol, and triethylamine is 0.7~2.1:0.6~1.8:0.5~1.

5.

7. The solid tire for an automatic guided vehicle (AGV) according to claim 1, characterized by The preparation method of thermally conductive filler includes the following steps: (1) Perfluorobutylethylene, lithium hydroxide and isopropanol are placed in a reactor, and silane coupling agent is added under nitrogen atmosphere. The mixture is stirred at room temperature for 3-4 hours. After the reaction is completed, the solvent is removed by rotary evaporation and then dried to obtain the modified silane coupling agent. (2) Take hexagonal boron nitride powder and disperse it in a mixture of isopropanol and deionized water. Sonicate for 1-2 hours, and then use an ultrasonic cleaner to ultrasonically peel off the mixture for 10-12 hours to obtain peeled boron nitride nanosheets. (3) Centrifuge the stripped boron nitride nanosheets at 4000-5000 rpm for 30-40 min, vacuum filter the supernatant obtained after centrifugation, and then vacuum dry at 100-110℃ for 10-12 h to obtain hydroxylated boron nitride nanoparticles. (4) Hydroxylated boron nitride nanoparticles were added to a mixture of ethanol and deionized water and ultrasonically dispersed for 1-2 hours. Then, modified silane coupling agent was added and stirred and refluxed in an oil bath at 100-110°C for 18-24 hours to obtain thermally conductive filler.

8. The solid tire for an automated guided vehicle (AGV) according to claim 7, characterized by In step (1), the silane coupling agent is KH-550 or KH-540, and the mass ratio of perfluorobutylethylene, lithium hydroxide and silane coupling agent is 1~1.6:0.1~0.16:0.9~1.

5.

9. The solid tire for an automated guided vehicle (AGV) according to claim 7, characterized by In step (2), the volume ratio of isopropanol to deionized water in the mixture is 1~3:1, and in step (4), the volume ratio of ethanol to deionized water in the mixture is 2~4:1; in step (2), the mass ratio of hexagonal boron nitride powder to modified silane coupling agent in step (4) is 15~30:1.5~2.

5.

10. The method for preparing solid tires for automated guided vehicles (AGVs) according to any one of claims 1-9, characterized in that, Includes the following steps: Polytetrahydrofuran ether glycol, antioxidant, light stabilizer, and anti-hydrolysis agent were added to a reactor and vacuum dried at 100-120℃ for 1.5-2 hours. After cooling to 60-65℃, diphenylmethane-4,4'-diisocyanate was added, and the temperature was raised to 70-80℃. The mixture was stirred for 2-3 hours. Then, a mixture of crosslinking modifier, 1,4-butanediol, dibutyltin dilaurate, and thermally conductive filler was added and rapidly mixed until homogeneous. Degas at 0.085 MPa for 2-3 minutes, inject into a mold preheated to 80-100℃, and hold under pressure of 5-10 MPa at 100-110℃ for 30-60 minutes. After the material has initially solidified and shaped, open the mold and remove the material. Place the demolded tire in an oven at 70-80℃ for 2-4 hours to cure, then mature at 100-110℃ for 1-2 hours, and finally place at room temperature for 5-7 days to obtain a solid tire for an automated guided vehicle (AGV).

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