High-temperature-resistant PET net tube and preparation method thereof

Abstract

The present application relates to a kind of high-temperature-resistant PET net tube and its preparation method, belong to composite material technical field.The net tube is woven base pipe with PET base as net tube matrix, and is solidified by impregnating heat-resistant paint;The weight percentage components of heat-resistant paint are as follows: modified silicone resin 40-50%, defoaming agent 0.15-0.2%, leveling agent 0.4-0.6%, tackifier 0.8-1.2% and the balance of composite solvent;Modified silicone resin is obtained by condensation reaction of hydroxyl silicone oil and vinyl phenyl dichlorosilane, and then addition reaction with 3-mercaptopropyl triethoxysilane, the side chain triethoxysilane is chemically coupled with the surface of PET fiber, and the in-situ introduction of phenyl in molecular chain enhances the thermal stability of coupling site, and the flexibility of polysiloxane flexible main chain keeps the flexibility of coating, so that the net tube has good heat resistance, adhesion durability and flexibility.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a high-temperature resistant PET mesh tube and its preparation method. Background Technology

[0002] Braided wire harnesses are protective sheaths made of monofilaments, widely used for wire harness management and protection. PET (polyethylene terephthalate) is a preferred material for braided wire harnesses due to its well-balanced properties, including good mechanical strength, abrasion resistance, flexibility, and electrical insulation. PET monofilament braided wire harnesses offer advantages such as good flexibility, strong fit, and easy installation, allowing for tight wrapping of wire harnesses and adaptability to complex wiring paths.

[0003] However, conventional PET materials have a low glass transition temperature. In harsh environments such as engine compartments, industrial furnace perimeters, and heating equipment, PET mesh tubing is prone to structural collapse and braiding loosening due to high temperatures, resulting in its inability to tightly wrap the wire harness and loss of its harness management and protection functions. Currently, there are two main technical solutions for improving the heat resistance of PET mesh tubing: Firstly, the PET matrix material is modified, including physical filling (such as adding glass fiber, nucleating agents, etc.) and chemical crosslinking modification. Although these methods can increase the heat distortion temperature of PET materials to a certain extent, they have significant drawbacks: filling and crosslinking restrict the movement of PET molecular chains, causing the material to become hard and brittle, losing the flexibility and fit required for the mesh tube, while also increasing the difficulty of bending the mesh tube during construction, and even causing damage to the woven structure.

[0004] Secondly, a heat-resistant layer is formed on the surface of PET mesh fibers using coating technology. This method can impart heat resistance to the mesh without significantly reducing the flexibility of the PET matrix. However, a common problem with existing technologies is that the bonding force between the heat-resistant coating and the PET matrix fibers is insufficient. During the installation, bending, stretching, or other use of the mesh, or under high-temperature thermal cycling, the heat-resistant coating is prone to peeling and cracking, resulting in a sharp decline in heat resistance and a significant reduction in service life.

[0005] Therefore, how to significantly improve the heat resistance of PET mesh pipes while maintaining their good flexibility and ease of construction, and ensure that the heat resistance function remains effective under long-term use and thermal effects, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] In order to solve the technical problems mentioned in the background art, the purpose of this invention is to provide a high-temperature resistant PET mesh tube and its preparation method.

[0007] The objective of this invention can be achieved through the following technical solutions: A high-temperature resistant PET mesh tube is made by impregnating a PET-based braided base tube with a heat-resistant coating and then curing it. Specifically, the heat-resistant coating comprises the following raw materials by weight percentage: 40-50% modified silicone resin, 0.15-0.2% defoamer, 0.4-0.6% leveling agent, 0.8-1.2% tackifier, and the balance being a composite solvent.

[0008] The preparation method of high-temperature resistant PET mesh tubes includes the following three aspects: 1) Synthesis of modified organosilicon resin Synthesis 1. Synthesis of intermediate: After drying the hydroxyl silicone oil, it was mixed with anhydrous tetrahydrofuran under a dry nitrogen atmosphere. After cooling in an ice-water bath, vinylphenyl dichlorosilane was slowly added and stirred thoroughly, controlling the reaction temperature to not exceed 10°C. Then, triethylamine was added and the ice-water bath was removed, and the reaction continued for 4-6 hours. After the reaction was completed, the reaction solution was filtered to remove the triethylamine salt, and then the tetrahydrofuran was recovered by rotary evaporation under reduced pressure to obtain the intermediate.

[0009] Synthesis 2: Synthesis of modified organosilicon resin: The intermediate, 3-mercaptopropyltriethoxysilane, and anhydrous acetone were premixed under a dry nitrogen atmosphere, followed by the addition of a photoinitiator. The mixture was then heated to 40-55℃, while using a strength of 10-15 mW / cm². 2 The mixture was subjected to ultraviolet irradiation for 2-3 hours. After the reaction was completed, the acetone was recovered by rotary evaporation of the reaction solution to obtain the modified organosilicon resin.

[0010] Furthermore, in the reaction of Synthesis 1, the molar ratio of hydroxyl content of hydroxyl silicone oil to vinylphenyl dichlorosilane is 2.4-2.8:1, and the amount of triethylamine used is 1.5-2 molar equivalents of vinylphenyl dichlorosilane; vinylphenyl dichlorosilane undergoes a condensation reaction with hydroxyl silicone oil, uniformly introducing vinylphenyl structural units into the polysiloxane chain.

[0011] Preferably, the hydroxyl silicone oil is a double-ended hydroxyl silicone oil; after block condensation, it forms a linear polymer, maintaining good chain flexibility and adapting to the deformation and bonding of the mesh tube.

[0012] Preferably, the average molecular weight of the hydroxyl silicone oil is 1000-3000; by using a low molecular weight hydroxyl silicone oil as the starting material, the resulting polymer chain still maintains a low degree of polymerization and good fluidity to adapt to impregnation processing.

[0013] Furthermore, in the synthesis reaction 2, the molar ratio of the alkenyl content of the intermediate to that of 3-mercaptopropyltriethoxysilane is 1:0.8-0.9, and the amount of photoinitiator is 0.15-0.25 wt% of the total amount of both; the thiol group in the 3-mercaptopropyltriethoxysilane molecule undergoes an addition reaction with the vinyl group on the side chain of the intermediate, thereby introducing a side chain triethoxysilane structure at the block node of the intermediate molecular chain.

[0014] 2) Formulation of heat-resistant coatings The defoamer, leveling agent and composite solvent are premixed, then the modified silicone resin is slowly added and stirred at high speed until homogeneous. After that, the thickener is added, mixed and vacuum degassed to obtain a heat-resistant coating.

[0015] 3) Preparation of PET mesh tubes Process 1, Braiding Base Tube and Pretreatment: PET monofilaments are braided into tubular braids on a high-speed braiding machine, and then surface-treated by a corona treatment device.

[0016] Step 2, Dipping: Immerse the corona-treated braided base tube into the heat-resistant coating, then remove the braided base tube and drain it.

[0017] Step 3, Steam curing: The coated braided mesh tube is sent into a steam curing device and cured under saturated steam for 15-20 minutes.

[0018] Step 4, hot air drying: The cured PET mesh tube is dried with hot air at 60-80℃ to remove moisture and obtain high temperature resistant PET mesh tube.

[0019] Preferably, the coating amount of the heat-resistant coating is 15-18%; a suitable coating amount forms a uniform coating on the surface of the PET monofilament, maintaining good heat resistance and physical protection properties.

[0020] The beneficial effects of this invention are: This invention, based on the coating reinforcement technology mechanism, provides a modified organosilicon resin as a coating film-forming material, and achieves a strong bond between the coating and the PET fiber surface through a steam thermal curing process. Compared with the prior art, this invention has the following advantages: The modified silicone resin incorporates both phenyl and triethoxysilane structures at the block nodes, while the molecular chain remains predominantly a flexible polysiloxane chain. During coating curing, the triethoxysilane side chains hydrolyze and couple with the PET fiber surface (especially the numerous active hydroxyl groups formed after corona treatment). These molecular-level "tentacles" anchor the modified silicone resin molecular chain to the PET fiber surface via covalent bonds. This ensures effective adhesion of the coating to the PET fiber surface, preventing detachment under deformation and heat. Furthermore, the modified silicone resin exhibits excellent thermal stability, maintaining stability even at high temperatures. These coupling sites act like… "Positioning pins" limit excessive thermal deformation and softening of PET fibers; in addition, the phenyl structure introduced in situ at the coupling sites enhances the strength and heat resistance of the coupling sites through physical reinforcement, thereby constructing stable anchoring sites. This ensures that the coating of the present invention not only adheres firmly at high temperatures, but also that the anchoring sites themselves do not undergo thermal degradation, guaranteeing the long-term effectiveness of the heat resistance function. This in-situ introduction method avoids the problem of low flexibility when using phenyl polysiloxanes; furthermore, the modified organosilicon resin does not produce additional cross-linking effects, and the molecular chain is mainly composed of flexible polysiloxane chains, so the coating maintains good flexibility, can respond to the deformation between PET monofilaments, and is easy to adhere to the surface of the wire harness. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1: Preparation of high-temperature resistant PET mesh tubes, the specific implementation method is as follows: I. Preparation of heat-resistant coatings Synthesis 1: Dry nitrogen gas was introduced into the reactor until a stable gas flow was discharged. Hydroxy silicone oil was vacuum dried, then added with anhydrous tetrahydrofuran and stirred until homogeneous. The mixture was cooled to below 5°C using an ice-water bath. Vinylphenyl dichlorosilane was then slowly added dropwise with rapid stirring, controlling the reaction temperature to not exceed 10°C during the addition process. Triethylamine was then added, and the ice-water bath was removed, with stirring continuing for 4 hours. The hydroxyl silicone oil used was MY 2110-1000 (average molecular weight approximately 1000) type double-hydroxyl-terminated silicone oil. The molar ratio of hydroxyl content in the hydroxyl silicone oil to vinylphenyl dichlorosilane was 2.4:1, and the total mass fraction of both in the anhydrous tetrahydrofuran was 20%. The amount of triethylamine used was 1.5 molar equivalents of vinylphenyl dichlorosilane. After the reaction was complete, acetone was recovered by rotary evaporation of the reaction solution to obtain the modified organosilicon resin.

[0023] Synthesis 2: Dry nitrogen gas was introduced into the reactor until a stable gas flow was discharged. The intermediate, 3-mercaptopropyltriethoxysilane, and anhydrous acetone were added and premixed. Then, a photoinitiator (photoinitiator 1173) was added and stirred. The mixture was heated to 40°C and a 365nm ultraviolet light source with an intensity of 15mW / cm² was used. 2 The reaction was carried out under ultraviolet irradiation and stirring for 3 hours. The molar ratio of the alkenyl content of the intermediate to 3-mercaptopropyltriethoxysilane was 1:0.8, the mass fraction of both in anhydrous acetone was 45%, and the amount of photoinitiator was 0.15 wt% of the total amount of both. After the reaction was completed, the acetone was recovered by rotary evaporation of the reaction solution to obtain the modified organosilicon resin.

[0024] The raw materials are calculated by weight percentage as follows: 50% modified silicone resin, prepared by the above method; 0.15% defoamer, using BYK-065 type raw material; 0.4% leveling agent, using BYK-306 type raw material; 1.2% tackifier, using industrial grade tetraethyl orthosilicate; the balance is a composite solvent, which is a mixture of industrial grade propylene glycol methyl ether acetate and propylene glycol methyl ether in a weight ratio of 3:1.

[0025] Compound heat-resistant coating: Defoamer, leveling agent and composite solvent are added and stirred for premixing, then modified organosilicon resin is slowly added and stirred at high speed to mix evenly, then thickener is added and mixed, and then the mixture is vacuum degassed to obtain heat-resistant coating.

[0026] II. Preparation of High-Temperature Resistant PET Mesh Tubes Step 1: 0.15mm PET monofilaments are woven into tubular braids on a high-speed braiding machine and fed into a corona treatment device with a power of 5.0kW and a processing rate of 20m / min to perform corona treatment on the braided base tube.

[0027] Step 2: Immerse the corona-treated braided base tube into the heat-resistant coating for 1 minute each time. After removing it, allow the excess coating to drip off naturally. Control the amount of heat-resistant coating (i.e., the weight gain after immersion) to be 15%.

[0028] Step 3: The coated braided mesh tube is sent into the steam curing equipment. Saturated steam is introduced into the equipment and the steam curing time is controlled to be 20 minutes.

[0029] Step 4: Take out the water vapor-cured mesh tube and dry it with hot air at 60℃ for 40 minutes to remove moisture, and obtain a high temperature resistant PET mesh tube.

[0030] Example 2: Preparation of high-temperature resistant PET mesh tubes, the specific implementation method is as follows: I. Preparation of heat-resistant coatings Synthesis 1: Dry nitrogen gas was introduced into the reactor until a stable gas flow was discharged. Hydroxy silicone oil was vacuum dried, then added with anhydrous tetrahydrofuran and stirred until homogeneous. The mixture was cooled to below 5°C using an ice-water bath. Vinylphenyl dichlorosilane was then slowly added dropwise with rapid stirring, controlling the reaction temperature to not exceed 10°C during the addition process. Triethylamine was then added, and the ice-water bath was removed, with stirring continuing for 4-6 hours. The hydroxyl silicone oil used was MY 2110-2500 (average molecular weight approximately 2500) type double-hydroxyl-terminated silicone oil. The molar ratio of hydroxyl content in the hydroxyl silicone oil to vinylphenyl dichlorosilane was 2.8:1, and the total mass fraction of both in the anhydrous tetrahydrofuran was 30%. The amount of triethylamine used was 2 molar equivalents of vinylphenyl dichlorosilane. After the reaction was complete, acetone was recovered by rotary evaporation of the reaction solution to obtain the modified organosilicon resin.

[0031] Synthesis 2: Dry nitrogen gas was introduced into the reactor until a stable gas flow was discharged. The intermediate, 3-mercaptopropyltriethoxysilane, and anhydrous acetone were added and premixed. Then, a photoinitiator (photoinitiator 1173) was added and stirred. The mixture was heated to 55°C and a 365nm ultraviolet light source with an intensity of 10mW / cm² was used. 2 The reaction was carried out under ultraviolet irradiation and stirring for 2 hours. The molar ratio of the alkenyl content of the intermediate to 3-mercaptopropyltriethoxysilane was 1:0.9, the mass fraction of both in anhydrous acetone was 60%, and the amount of photoinitiator was 0.25 wt% of the total amount of both. After the reaction was completed, the acetone was recovered by rotary evaporation of the reaction solution to obtain the modified organosilicon resin.

[0032] The raw materials are calculated as follows by weight percentage: 40% modified silicone resin, prepared by the above method; 0.2% defoamer, using BYK-065 type raw material; 0.6% leveling agent, using BYK-306 type raw material; 0.8% tackifier, using industrial grade tetraethyl orthosilicate; the balance is a composite solvent, which is a mixture of industrial grade propylene glycol methyl ether acetate and propylene glycol methyl ether in a weight ratio of 3:1.

[0033] Compound heat-resistant coating: Defoamer, leveling agent and composite solvent are added and stirred for premixing, then modified organosilicon resin is slowly added and stirred at high speed to mix evenly, then thickener is added and mixed, and then the mixture is vacuum degassed to obtain heat-resistant coating.

[0034] II. Preparation of High-Temperature Resistant PET Mesh Tubes Step 1: 0.15mm PET monofilaments are woven into tubular braids on a high-speed braiding machine and fed into a corona treatment device with a power of 5.0kW and a processing rate of 20m / min to perform corona treatment on the braided base tube.

[0035] Step 2: Immerse the corona-treated braided base tube into the heat-resistant coating for 1 minute each time. After removing it, allow the excess coating to drip off naturally, and control the coating amount of the heat-resistant coating to be 18%.

[0036] Step 3: The coated braided mesh tube is sent into the steam curing equipment. Saturated steam is introduced into the equipment and the steam curing time is controlled to be 15 minutes.

[0037] Step 4: Take out the water vapor-cured mesh tube and dry it with hot air at 80℃ for 30 minutes to remove moisture, and obtain a high temperature resistant PET mesh tube.

[0038] Example 3: Preparation of high-temperature resistant PET mesh tubes, the specific implementation method is as follows: I. Preparation of heat-resistant coatings Synthesis 1: Dry nitrogen gas was introduced into the reactor until a stable gas flow was discharged. Hydroxy silicone oil was vacuum dried, then added with anhydrous tetrahydrofuran and stirred until homogeneous. The mixture was cooled to below 5°C using an ice-water bath. Vinylphenyl dichlorosilane was then slowly added dropwise with rapid stirring, controlling the reaction temperature to not exceed 10°C during the addition process. Triethylamine was then added, and the ice-water bath was removed, with stirring continuing for 4-6 hours. The hydroxyl silicone oil used was MY 2110-2000 (average molecular weight approximately 2000) type double-hydroxyl-terminated silicone oil. The molar ratio of hydroxyl content in the hydroxyl silicone oil to vinylphenyl dichlorosilane was 2.6:1, and the total mass fraction of both in the anhydrous tetrahydrofuran was 25%. The amount of triethylamine used was 1.8 molar equivalents of vinylphenyl dichlorosilane. After the reaction was complete, acetone was recovered by rotary evaporation of the reaction solution to obtain the modified organosilicon resin.

[0039] Synthesis 2: Dry nitrogen gas was introduced into the reactor until a stable gas flow was discharged. The intermediate, 3-mercaptopropyltriethoxysilane, and anhydrous acetone were added and premixed. Then, a photoinitiator (photoinitiator 1173) was added and stirred. The mixture was heated to 50°C and a 365nm ultraviolet light source with an intensity of 15mW / cm² was used. 2 The reaction was carried out under ultraviolet irradiation and stirring for 2.2 h. The molar ratio of the alkenyl content of the intermediate to 3-mercaptopropyltriethoxysilane was 1:0.8, the mass fraction of both in anhydrous acetone was 50%, and the amount of photoinitiator was 0.2 wt% of the total amount of both. After the reaction was completed, the acetone was recovered by rotary evaporation of the reaction solution to obtain the modified organosilicon resin.

[0040] The raw materials are calculated by weight percentage as follows: 42% modified silicone resin, prepared by the above method; 0.2% defoamer, using BYK-065 type raw material; 0.5% leveling agent, using BYK-306 type raw material; 1% tackifier, using industrial grade tetraethyl orthosilicate; the balance is a composite solvent, which is a mixture of industrial grade propylene glycol methyl ether acetate and propylene glycol methyl ether in a weight ratio of 3:1.

[0041] Compound heat-resistant coating: Defoamer, leveling agent and composite solvent are added and stirred for premixing, then modified organosilicon resin is slowly added and stirred at high speed to mix evenly, then thickener is added and mixed, and then the mixture is vacuum degassed to obtain heat-resistant coating.

[0042] II. Preparation of High-Temperature Resistant PET Mesh Tubes Step 1: 0.15mm PET monofilaments are woven into tubular braids on a high-speed braiding machine and fed into a corona treatment device with a power of 5.0kW and a processing rate of 20m / min to perform corona treatment on the braided base tube.

[0043] Step 2: Immerse the corona-treated braided base tube into the heat-resistant coating for 1 minute each time. After removing it, allow the excess coating to drip off naturally, and control the coating amount of the heat-resistant coating to be 17%.

[0044] Step 3: The coated braided mesh tube is sent into the steam curing equipment. Saturated steam is introduced into the equipment and the steam curing time is controlled to be 20 minutes.

[0045] Step 4: Take out the water vapor-cured mesh tube and dry it with hot air at 80℃ for 30 minutes to remove moisture, and obtain a high temperature resistant PET mesh tube.

[0046] Comparative Example 1: This comparative example is a blank control, and the braided base tube made of PET monofilaments in Example 3 is selected.

[0047] Comparative Example 2: A commercially available epoxy-modified silicone emulsion, model HA-920, was used to dip-coat the braided base tube.

[0048] Comparative Example 3: A commercially available crosslinkable silicone emulsion, model ADM2008, was used to impregnate the braided base tube.

[0049] A 200mm section of the prepared PET mesh tube was cut as a sample. The sample was installed vertically, fixed at the top, and a 200g weight was clamped at the bottom. It was heat-treated at 150℃ for 24 hours. After removal, the weight was removed and the sample was allowed to cool naturally for 6 hours. The length change rate before and after heat treatment was measured and calculated. The sample was then placed on the surface of a metal rod with a diameter 1.2 times its own. It was heat-treated at 150℃ for 24 hours. The metal rod was then removed and allowed to cool naturally for 6 hours. The diameter change rate before and after heat treatment was measured and calculated. The specific test results are shown in Table 1. Table 1

[0050] As can be seen from the test data in Table 1, the mesh tubes all underwent irreversible deformation after heat treatment. After dip coating treatment in Examples 2 and 3, the deformation was effectively suppressed. Among them, the irreversible deformation of Examples 2 and 3 was significantly lower than that of Comparative Examples. This may be because the modified silicone resin, as a film-forming material, has a molecular chain mainly composed of flexible siloxane chains, which can change with the deformation of PET monofilament fibers. Numerous molecular-level coupling anchoring sites play a limiting and fixing role, preventing excessive deformation of PET monofilaments.

[0051] The above samples were subjected to stability tests, specifically including: placing the mesh tube over the surface of a cable with a diameter 1.2 times its diameter, wrapping it 180° around a metal rod, and observing the smallest diameter (expressed as a multiple of the inner diameter of the mesh tube) of the PET monofilament coating without obvious cracks using a magnifying glass; weighing the mesh tubes and performing a reciprocating bending test, specifically: heat-treating the sample at 120℃ for 6 hours, naturally cooling for 1 hour, wrapping it around a metal rod with an inner diameter 5 times its diameter for 1 hour, repeating this cycle 50 times, blowing the mesh tube with 3 bar compressed air, weighing it again, and calculating the weight change rate after the reciprocating bending; the specific test results are shown in Table 2. Table 2

[0052] As can be seen from the test data in Table 2, the minimum bending diameter of the embodiment is 1.5-2 times the inner diameter of the mesh tube, which is significantly lower than that of the comparative example. This indicates that the surface coating of the mesh tube in the embodiment has superior flexibility, and the weight change rate under repeated bending is significantly lower than that of the comparative example. This shows that the coating peels off very little during repeated bending and can maintain its protective ability.

[0053] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0054] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A high-temperature resistant PET mesh tube, comprising a PET-based braided base tube as the mesh tube matrix, and composited by impregnation with a heat-resistant coating and curing, characterized in that, The heat-resistant coating comprises the following raw materials by weight percentage: 40-50% modified silicone resin, 0.15-0.2% defoamer, 0.4-0.6% leveling agent, 0.8-1.2% tackifier, and the balance being a composite solvent; The modified silicone resin is prepared by the following method: Synthesis 1: Under dry conditions, hydroxyl silicone oil and anhydrous tetrahydrofuran were mixed and then vinylphenyl dichlorosilane was slowly added under ice-water bath cooling. Triethylamine was then added and the ice-water bath was removed to continue the reaction for 4-6 hours. After treatment, an intermediate was prepared. Synthesis 2: Under dry conditions, the intermediate, 3-mercaptopropyltriethoxysilane, and anhydrous acetone were premixed, and then a photoinitiator was added and the mixture was heated at 40-55°C and 10-15 mW / cm². 2 After being subjected to ultraviolet irradiation for 2-3 hours, the modified organosilicon resin is prepared.

2. The high-temperature resistant PET mesh tube according to claim 1, characterized in that, The molar ratio of hydroxyl content in hydroxyl silicone oil to vinylphenyl dichlorosilane is 2.4-2.8:1, and the amount of triethylamine used is 1.5-2 molar equivalents of vinylphenyl dichlorosilane.

3. The high-temperature resistant PET mesh tube according to claim 2, characterized in that, Hydroxy silicone oil is a double-terminated hydroxyl silicone oil.

4. The high-temperature resistant PET mesh tube according to claim 3, characterized in that, The average molecular weight of hydroxyl silicone oil is 1000-3000.

5. A high-temperature resistant PET mesh tube according to claim 4, characterized in that, The alkenyl content of the intermediate and the molar ratio of 3-mercaptopropyltriethoxysilane are 1:0.8-0.9, and the amount of photoinitiator is 0.15-0.25 wt% of the total amount of both.

6. The high-temperature resistant PET mesh tube according to claim 1, characterized in that, The preparation method of heat-resistant coating is as follows: premix defoamer, leveling agent and composite solvent, then slowly add modified organosilicon resin and mix at high speed, then add tackifier, mix and vacuum degas to obtain heat-resistant coating.

7. A method for preparing a high-temperature resistant PET mesh tube according to any one of claims 1-6, characterized in that, The process includes the following steps: Process 1: PET monofilaments are woven into tubular braids on a high-speed braiding machine, and then surface-treated by a corona treatment device; Step 2: Immerse the corona-treated braided base tube in heat-resistant coating, then remove the braided base tube and drain it; Step 3: The coated braided mesh tube is sent into a steam curing equipment and cured under saturated steam for 15-20 minutes; Step 4: Dry the cured PET mesh tube with hot air at 60-80℃ to remove moisture and obtain a high-temperature resistant PET mesh tube.

8. The method for preparing a high-temperature resistant PET mesh tube according to claim 7, characterized in that, The coating weight of the heat-resistant coating is 15-18%.

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