High temperature resistant polyvinyl chloride adhesive tape and preparation method thereof

Abstract

The application discloses a high-temperature-resistant polyvinyl chloride adhesive tape and a preparation method thereof, and belongs to the technical field of polymer materials and adhesive products. The high-temperature-resistant polyvinyl chloride adhesive tape comprises the following raw materials in parts by weight: synergistically modified polyvinyl chloride, diphenyl phosphine oxide, chlorinated polyethylene, diisononyl phthalate, antimony trioxide, calcium stearate, zinc stearate, an antioxidant and a leveling agent; the synergistically modified polyvinyl chloride is obtained by introducing catechol structures on the surface of polyvinyl chloride through dopamine self-polymerization deposition, forming a dynamic borate ester structure with 3-aminobenzoic acid, and constructing a Si-O-Si network structure through hydrolytic condensation reaction of octa(3-aminopropyl)silsesquioxane and N-(beta-aminoethyl)-gamma-aminopropyl triethoxysilane. The dopamine-borate ester-silicone synergistic network structure is constructed, and the diphenyl phosphine oxide is introduced for function regulation, so that the heat resistance, mechanical properties and dimensional stability of the polyvinyl chloride adhesive tape are significantly improved.

Description

Technical Field

[0001] This invention belongs to the technical field of polymer materials and adhesive products, specifically relating to a high-temperature resistant polyvinyl chloride tape and its preparation method. Background Technology

[0002] Polyvinyl chloride (PVC) is a widely used general-purpose polymer material. Due to its low cost, good processing performance, excellent electrical insulation properties, good flame retardancy, and stable mechanical properties, it is widely used in electrical insulation tapes, wire harness covering tapes, pipe protective tapes, and industrial protective tapes. In power equipment, automotive wiring harnesses, electronic appliances, and building electrical systems, PVC tapes are typically used for conductor insulation protection, wiring fixation, and protective wrapping, requiring high levels of flexibility, heat resistance, and dimensional stability.

[0003] However, polyvinyl chloride (PVC) is a polymer with relatively low thermal stability. Its molecular structure contains a large number of polar C–Cl bonds, which easily undergo dehydrochlorination under heating conditions, leading to discoloration, degradation, and a decrease in mechanical properties. Therefore, the long-term operating temperature of traditional PVC tapes is generally only 60–80°C. In higher temperature environments, it is prone to softening, creep, decreased adhesion, and reduced insulation performance, making it difficult to meet the application requirements of automotive engine compartments, electrical equipment, and some high-temperature industrial environments.

[0004] To improve the heat resistance of PVC materials, existing technologies typically modify them by adding heat stabilizers, inorganic fillers, or heat-resistant plasticizers. For example, adding antimony trioxide, metal soap stabilizers, or inorganic fillers can improve the material's thermal stability, or introducing blends such as chlorinated polyethylene can enhance its heat resistance. However, most of these modification methods are physical blending modifications, lacking stable molecular structure support within the material. This makes them prone to phase separation or additive migration under long-term thermal stress, leading to a gradual decline in material performance. Furthermore, the addition of some inorganic fillers can reduce the material's flexibility, affecting the processing and performance of PVC tapes.

[0005] Therefore, how to construct a stable synergistic structural network in the polyvinyl chloride system through molecular structure design, thereby significantly improving the heat resistance and structural stability of PVC materials while maintaining their flexibility and processing performance, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To overcome the problems of poor heat resistance, softening, creep, and performance degradation of existing polyvinyl chloride (PVC) tapes at high temperatures, this invention aims to provide a high-temperature resistant PVC tape and its preparation method. This invention synergistically modifies PVC by constructing a dopamine-boronate-organosilicon synergistic network structure on the PVC surface, and introduces diphenylphosphine oxide as an organic small-molecule functional regulator. Simultaneously, it combines chlorinated polyethylene, diisononyl phthalate, and stabilizers to form a composite system, thereby obtaining a PVC tape material with excellent heat resistance and structural stability. This invention, by constructing a dynamic boronate structure and an organosilicon network synergistic structure combined with the heat resistance regulating effect of diphenylphosphine oxide, can significantly improve the heat resistance and high-temperature dimensional stability of the PVC tape.

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

[0008] A high-temperature resistant polyvinyl chloride (PVC) tape comprises the following raw materials in parts by weight: 70-120 parts of synergistically modified PVC; 0.5-6 parts of diphenylphosphine oxide; 5-20 parts of chlorinated polyethylene; 20-45 parts of diisononyl phthalate; 1-6 parts of antimony trioxide; 0.5-2 parts of calcium stearate; 0.5-2 parts of zinc stearate; 0.2-1 parts of antioxidant; and 0.1-1 parts of leveling agent. The synergistically modified PVC is obtained by introducing a catechol structure into PVC under dopamine self-polymerization deposition, further reacting it with 3-aminophenylboronic acid through dynamic borate ester bond interaction, and simultaneously constructing a Si-O-Si network structure through the condensation reaction of octa(3-aminopropyl)silsesquioxane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.

[0009] Optionally, the synergistically modified polyvinyl chloride comprises the following raw materials in parts by weight: 80-120 parts of polyvinyl chloride; 0.5-6 parts of dopamine; 0.3-4 parts of 3-aminophenylboronic acid; 0.5-5 parts of octa(3-aminopropyl)silsesquioxane; and 0.5-4 parts of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.

[0010] Optionally, the preparation method of synergistically modified polyvinyl chloride includes the following steps:

[0011] (1) Polyvinyl chloride is dispersed in a mixed solution of ethanol and deionized water, and then dopamine is added. The mixture is stirred under alkaline conditions to allow dopamine to self-polymerize and deposit on the surface of polyvinyl chloride, thus obtaining surface-premodified polyvinyl chloride.

[0012] (2) Add 3-aminophenylboronic acid to the surface premodified polyvinyl chloride system to react, so that 3-aminophenylboronic acid and catechol structure in the dopamine self-polymer layer can form dynamic borate bond, and obtain boronic acid dynamically modified polyvinyl chloride.

[0013] (3) Add octa(3-aminopropyl)silsesquioxane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane to the boronic acid ester dynamically modified polyvinyl chloride system and react them. After hydrolysis and condensation, an organosilicon network structure is constructed on the surface of polyvinyl chloride. After the reaction is completed, filter, wash and dry to obtain synergistically modified polyvinyl chloride.

[0014] Optionally, the reaction conditions in step (1) are: reaction temperature of 30-60℃, reaction time of 1-4h, system pH of 8-9, and stirring speed of 300-600rpm.

[0015] Optionally, the reaction conditions in step (2) are: reaction temperature of 40-70℃, reaction time of 1-3h, system pH of 7-9, and stirring speed of 300-600rpm.

[0016] Optionally, the reaction conditions in step (3) are a reaction temperature of 60-90°C, a reaction time of 2-5 h, and a stirring speed of 300-700 rpm.

[0017] Optionally, the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:(0.5-2); the leveling agent is a mixture of polyether-modified polydimethylsiloxane and polyacrylate leveling agent in a mass ratio of 1:(0.5-1.5).

[0018] Optionally, a method for preparing a high-temperature resistant polyvinyl chloride tape includes the following steps:

[0019] S1, synergistically modified polyvinyl chloride, diphenylphosphine oxide, and chlorinated polyethylene are mixed, and then diisononyl phthalate, calcium stearate, zinc stearate, antioxidant and leveling agent are added and mixed to obtain a premixed material;

[0020] S2, the premixed material is melt-blended and extruded to obtain polyvinyl chloride tape base material granules;

[0021] S3, calender the PVC tape base material particles to obtain a high-temperature resistant PVC tape base film.

[0022] Optionally, the reaction conditions for step S1 are as follows: mixing is carried out in a high-speed mixer at a mixing temperature of 85–105°C, a mixing time of 8–15 min, a heating rate of 3–5°C / min, and a stirring speed of 400–700 rpm; the reaction conditions for step S2 are as follows: melt extrusion is carried out in a twin-screw extruder at an extrusion temperature of 140–150°C in zone 1, 150–165°C in zone 2, 165–175°C in zone 3, a die head temperature of 170–180°C, and a screw speed of 100–180 rpm.

[0023] Optionally, the reaction conditions for step S3 are as follows: calendering is performed in a calender, the calendering temperature is 155-185℃, the roller linear speed is 5-15m / min, the calendering time is 3-8min, and the cooling and setting temperature is 20-40℃.

[0024] The beneficial effects of this invention are:

[0025] This invention constructs a dopamine-boronate-organosilicon synergistic network structure on the surface of polyvinyl chloride (PVC). This allows the catechol structure in the dopamine self-polymer layer to form dynamic boronate bonds with 3-aminophenylboronic acid. Simultaneously, a stable Si-O-Si three-dimensional network structure is formed through the hydrolytic condensation reaction of octa(3-aminopropyl)silsesquioxane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane. This synergistic structure enables the formation of a multi-scale dynamic cross-linking system between PVC molecular chains, significantly improving the material's thermal and structural stability. Furthermore, diphenylphosphine oxide is introduced as a small organic molecule functional regulator. Its P=O structure possesses strong polarity and thermal stability, enabling it to form stable intermolecular forces with PVC molecular chains and the dopamine structure. This further enhances the material's heat resistance and inhibits molecular chain movement under high-temperature conditions, effectively improving the high-temperature resistance, creep resistance, and dimensional stability of the PVC tape. This allows it to maintain good mechanical and insulating properties even in high-temperature environments. Attached Figure Description

[0026] The invention will now be further described with reference to the accompanying drawings.

[0027] Figure 1 A comparison of the infrared spectra of polyvinyl chloride and synergistically modified polyvinyl chloride;

[0028] Figure 2 A comparison chart of tensile strength results for samples with different mix proportions. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments. However, the present invention is not limited to the following embodiments. Equivalent adjustments made without departing from the spirit and essence of the present invention should also be considered to fall within the protection scope of the present invention.

[0030] Example 1: This example verifies that when the amount of each raw material and the reaction conditions are in a low range, the dopamine-boronate-organosilicon synergistic structure constructed in this invention can still form a stable modified layer on the surface of polyvinyl chloride, thereby obtaining a polyvinyl chloride tape material with certain heat resistance.

[0031] S1, Preparation of Synergistically Modified Polyvinyl Chloride

[0032] 80 parts of polyvinyl chloride were dispersed in a mixed solution of ethanol and deionized water in a volume ratio of 1:1 and stirred at 300 rpm at 30°C. Then, 0.5 parts of dopamine were added and the pH of the system was adjusted to 8. The reaction was carried out for 1 hour under these conditions to allow dopamine to self-polymerize and deposit on the surface of polyvinyl chloride, thus obtaining surface-premodified polyvinyl chloride.

[0033] Subsequently, 0.3 parts of 3-aminophenylboronic acid were added to the system, and the mixture was stirred at 300 rpm for 1 h at 40 °C to allow the 3-aminophenylboronic acid to form a dynamic borate ester structure with the catechol structure in the dopamine layer, thus obtaining borate-modified polyvinyl chloride. Then, 0.5 parts of octa(3-aminopropyl)silsesquioxane and 0.5 parts of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane were added, and the mixture was stirred at 300 rpm for 2 h at 60 °C to allow the silane to undergo a hydrolysis-condensation reaction and form a Si-O-Si network structure on the surface of the polyvinyl chloride. After the reaction was completed, the mixture was filtered, washed, and dried to obtain synergistically modified polyvinyl chloride.

[0034] S2, melt blending

[0035] 70 parts of synergistically modified polyvinyl chloride, 0.5 parts of diphenylphosphine oxide and 5 parts of chlorinated polyethylene were added to a high-speed mixer and mixed. Then, 20 parts of diisononyl phthalate, 1 part of antimony trioxide, 0.5 parts of calcium stearate, 0.5 parts of zinc stearate, 0.2 parts of antioxidant and 0.1 parts of leveling agent were added and stirred at 400 rpm for 8 minutes at 85°C to obtain a premixed material.

[0036] The premixed material was then added to a twin-screw extruder for melt extrusion. The extrusion temperatures were 140°C in zone 1, 150°C in zone 2, 165°C in zone 3, and 170°C at the die head. The screw speed was 100 rpm. After melt plasticization, the material was extruded and granulated to obtain polyvinyl chloride tape base material granules.

[0037] S3, Calendering

[0038] The obtained polyvinyl chloride tape base material granules were added to a calender for calendering. The calendering was carried out at 155°C with a roller linear speed of 5m / min and a calendering time of 3min. Then, the calendering was cooled and shaped at 20°C to obtain a high-temperature resistant polyvinyl chloride tape base film.

[0039] Example 2: This example verifies that when the ratio of each raw material and the reaction conditions are within a moderate range, the synergistic network structure constructed by the present invention can form a more stable structure in the polyvinyl chloride system, thereby obtaining a polyvinyl chloride tape material with better heat resistance and mechanical properties.

[0040] S1, Preparation of Synergistically Modified Polyvinyl Chloride

[0041] 100 parts of polyvinyl chloride (PVC) were dispersed in a 1:1 volume ratio of ethanol to deionized water and stirred at 450 rpm at 45°C. Then, 3 parts of dopamine were added, and the pH of the system was adjusted to 8.5. The reaction was carried out for 2.5 h under these conditions, allowing dopamine to self-polymerize and deposit on the PVC surface, resulting in surface-premodified PVC. Next, 2 parts of 3-aminophenylboronic acid were added to the system, and the reaction was carried out at 55°C with stirring at 450 rpm for 2 h, allowing it to form dynamic borate ester bonds with the catechol structure in the dopamine layer, resulting in boronic acid ester dynamically modified PVC. Then, 3 parts of octa(3-aminopropyl)silsesquioxane and 2 parts of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane were added, and the reaction was carried out at 75°C with stirring at 500 rpm for 3.5 h, allowing the silane to undergo hydrolysis and condensation to form a Si-O-Si network structure. After the reaction, the mixture was filtered, washed, and dried to obtain synergistically modified PVC.

[0042] S2, melt blending

[0043] 95 parts of co-modified polyvinyl chloride, 3 parts of diphenylphosphine oxide, and 12 parts of chlorinated polyethylene were added to a high-speed mixer and mixed. Then, 32 parts of diisononyl phthalate, 3 parts of antimony trioxide, 1 part of calcium stearate, 1 part of zinc stearate, 0.6 parts of antioxidant, and 0.5 parts of leveling agent were added. The mixture was stirred at 550 rpm for 12 minutes at 95°C to obtain a premixed material. The premixed material was then added to a twin-screw extruder for melt extrusion. The extrusion temperatures were 145°C in zone 1, 160°C in zone 2, 170°C in zone 3, and 175°C at the die head. The screw speed was 140 rpm. After melt plasticization, the material was extruded and granulated to obtain polyvinyl chloride tape base material granules. Figure 1 The infrared spectrum comparison shows that the unmodified polyvinyl chloride has a wavelength of 2925 cm⁻¹. -1 and 2850cm -1 A distinct –CH2– stretching vibration absorption peak appears at 695 cm⁻¹. -1 The presence of characteristic C–Cl absorption peaks nearby indicates that the material possesses typical polyvinyl chloride structural characteristics; the modified material exhibits a peak at 3430 cm⁻¹. -1 An absorption peak for O–H stretching vibrations appears nearby, at 1600 cm⁻¹. -1 The presence of a C=C vibrational peak in the vicinity of the aromatic ring indicates that the dopamine structure has been successfully introduced into the polyvinyl chloride system; simultaneously, at 1250 cm⁻¹... -1 The presence of B–O–C vibration peaks and a distinct Si–O–Si stretching vibration peak near 1100 cm⁻¹ indicates the successful formation of the borate ester structure and the organosilicon network structure. The modified material retains the characteristic peaks of PVC while adding a variety of functional group characteristic peaks, proving that dopamine, borate esters and organosilicon structures have been successfully introduced into the polyvinyl chloride system, achieving synergistic modification of polyvinyl chloride.

[0044] S3, Calendering

[0045] The obtained polyvinyl chloride tape base material granules were added to a calender for calendering. The calendering was carried out at 170°C with a roller linear speed of 10 m / min and a calendering time of 5 min. Then, the calendering was cooled and shaped at 30°C to obtain a high-temperature resistant polyvinyl chloride tape base film.

[0046] Example 3: This example verifies that when the dosage of each component and the reaction conditions are within a high range, the synergistic network structure constructed by the present invention can further enhance the structural stability of polyvinyl chloride materials, thereby obtaining polyvinyl chloride tape materials with better heat resistance.

[0047] S1, Preparation of Synergistically Modified Polyvinyl Chloride

[0048] 120 parts of polyvinyl chloride (PVC) were dispersed in a 1:1 volume ratio of ethanol to deionized water and stirred at 600 rpm at 60°C. Then, 6 parts of dopamine were added, and the pH of the system was adjusted to 9. The reaction was carried out for 4 hours under these conditions, allowing dopamine to self-polymerize and deposit on the PVC surface, resulting in surface-premodified PVC. Next, 4 parts of 3-aminophenylboronic acid were added to the system, and the reaction was carried out at 70°C with stirring at 600 rpm for 3 hours, allowing it to form dynamic borate ester bonds with the catechol structure in the dopamine layer, resulting in boronic acid ester dynamically modified PVC. Then, 5 parts of octa(3-aminopropyl)silsesquioxane and 4 parts of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane were added, and the reaction was carried out at 90°C with stirring at 700 rpm for 5 hours, allowing the silane to undergo hydrolysis and condensation, forming a stable Si-O-Si network structure on the PVC surface. After the reaction, the mixture was filtered, washed, and dried to obtain synergistically modified PVC.

[0049] S2, melt blending

[0050] 120 parts of co-modified polyvinyl chloride, 6 parts of diphenylphosphine oxide, and 20 parts of chlorinated polyethylene were added to a high-speed mixer and mixed. Then, 45 parts of diisononyl phthalate, 6 parts of antimony trioxide, 2 parts of calcium stearate, 2 parts of zinc stearate, 1 part of antioxidant, and 1 part of leveling agent were added. The mixture was stirred at 700 rpm for 15 minutes at 105°C to obtain a premixed material. The premixed material was then added to a twin-screw extruder for melt extrusion. The extrusion temperatures were 150°C in zone 1, 165°C in zone 2, 175°C in zone 3, and 180°C at the die head. The screw speed was 180 rpm. After melt plasticization, the material was extruded and granulated to obtain polyvinyl chloride tape base material granules.

[0051] S3, Calendering

[0052] The obtained polyvinyl chloride tape base material granules were added to a calender for calendering. The calendering was carried out at 185°C with a roller linear speed of 15m / min and a calendering time of 8min. Then, the calendering was cooled and shaped at 40°C to obtain a high-temperature resistant polyvinyl chloride tape base film.

[0053] Comparative Example 1: This comparative example aims to verify the effect of using only the dopamine-boronate dynamic structure to modify polyvinyl chloride on the heat resistance and mechanical properties of polyvinyl chloride tape.

[0054] S1, Preparation of single modified polyvinyl chloride

[0055] 100 parts of polyvinyl chloride (PVC) were dispersed in a 1:1 volume ratio of ethanol to deionized water and stirred at 450 rpm at 45°C. Then, 3 parts of dopamine were added and the pH of the system was adjusted to 8.5. The reaction was carried out for 2.5 h under these conditions, allowing dopamine to self-polymerize and deposit on the PVC surface, resulting in surface-premodified PVC. Subsequently, 2 parts of 3-aminophenylboronic acid were added to the system and stirred at 450 rpm at 55°C for 2 h, allowing it to form dynamic borate ester bonds with the catechol structure in the dopamine layer. After the reaction was completed, the mixture was filtered, washed, and dried to obtain PVC modified with a single dynamic borate ester.

[0056] S2, melt blending

[0057] 95 parts of polyvinyl chloride modified with a single dynamic borate ester, 3 parts of diphenylphosphine oxide, and 12 parts of chlorinated polyethylene were added to a high-speed mixer and mixed. Then, 32 parts of diisononyl phthalate, 3 parts of antimony trioxide, 1 part of calcium stearate, 1 part of zinc stearate, 0.6 parts of antioxidant, and 0.5 parts of leveling agent were added and stirred at 550 rpm for 12 minutes at 95°C to obtain a premixed material. The premixed material was then added to a twin-screw extruder for melt extrusion at the following temperatures: 145°C in zone 1, 160°C in zone 2, 170°C in zone 3, and 175°C at the die head. The screw speed was 140 rpm. After melt plasticization, the material was extruded and granulated to obtain polyvinyl chloride tape base material granules.

[0058] S3, Calendering

[0059] The obtained polyvinyl chloride tape base material granules were added to a calender for calendering. The calendering was carried out at 170°C with a roller linear speed of 10 m / min and a calendering time of 5 min. Then, the calendering was cooled and set at 30°C to obtain a polyvinyl chloride tape base film.

[0060] Comparative Example 2: This comparative example aims to verify the effect of using only an organosilicon network structure to modify polyvinyl chloride on the heat resistance and mechanical properties of polyvinyl chloride tape.

[0061] S1, Preparation of single modified polyvinyl chloride

[0062] 100 parts of polyvinyl chloride (PVC) were dispersed in a 1:1 volume ratio of ethanol to deionized water and stirred at 450 rpm at 45°C. Subsequently, 3 parts of octa(3-aminopropyl)silsesquioxane and 2 parts of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane were added to the system and stirred at 500 rpm at 75°C for 3.5 h. This allowed the octa(3-aminopropyl)silsesquioxane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane to undergo hydrolysis and condensation, forming a Si-O-Si network structure on the PVC surface. After the reaction was completed, the mixture was filtered, washed, and dried to obtain PVC modified with a single organosilicon network.

[0063] S2, melt blending

[0064] 95 parts of single organosilicon network modified polyvinyl chloride, 3 parts of diphenylphosphine oxide and 12 parts of chlorinated polyethylene were added to a high-speed mixer and mixed. Then, 32 parts of diisononyl phthalate, 3 parts of antimony trioxide, 1 part of calcium stearate, 1 part of zinc stearate, 0.6 parts of antioxidant and 0.5 parts of leveling agent were added and stirred at 550 rpm for 12 min at 95°C to obtain a premixed material. The premixed material was then added to a twin-screw extruder for melt extrusion. The extrusion temperatures were 145°C in zone 1, 160°C in zone 2, 170°C in zone 3, and 175°C at the die head. The screw speed was 140 rpm. After melt plasticization, the material was extruded and granulated to obtain polyvinyl chloride tape base material granules.

[0065] S3, Calendering

[0066] The obtained polyvinyl chloride tape base material granules were added to a calender for calendering. The calendering was carried out at 170°C with a roller linear speed of 10 m / min and a calendering time of 5 min. Then, the calendering was cooled and set at 30°C to obtain a polyvinyl chloride tape base film.

[0067] Comparative Example 3: This comparative example aims to verify the effect of not adding organic small molecule diphenylphosphine oxide on the heat resistance and mechanical properties of PVC tape when using synergistically modified PVC.

[0068] S1, Preparation of Synergistically Modified Polyvinyl Chloride

[0069] 100 parts of polyvinyl chloride (PVC) were dispersed in a 1:1 volume ratio of ethanol to deionized water and stirred at 450 rpm at 45°C. Then, 3 parts of dopamine were added, and the pH of the system was adjusted to 8.5. The reaction was carried out for 2.5 h under these conditions, allowing dopamine to self-polymerize and deposit on the PVC surface, resulting in surface-premodified PVC. Next, 2 parts of 3-aminophenylboronic acid were added to the system, and the reaction was carried out at 55°C with stirring at 450 rpm for 2 h, allowing it to form dynamic borate ester bonds with the catechol structure in the dopamine layer, resulting in boronic acid ester dynamically modified PVC. Then, 3 parts of octa(3-aminopropyl)silsesquioxane and 2 parts of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane were added, and the reaction was carried out at 75°C with stirring at 500 rpm for 3.5 h, allowing the silane to undergo hydrolysis and condensation to form a Si-O-Si network structure. After the reaction, the mixture was filtered, washed, and dried to obtain synergistically modified PVC.

[0070] S2, melt blending

[0071] 95 parts of co-modified polyvinyl chloride and 12 parts of chlorinated polyethylene were added to a high-speed mixer and mixed. Then, 32 parts of diisononyl phthalate, 3 parts of antimony trioxide, 1 part of calcium stearate, 1 part of zinc stearate, 0.6 parts of antioxidant, and 0.5 parts of leveling agent were added. The mixture was stirred at 550 rpm for 12 minutes at 95°C to obtain a premixed material. The premixed material was then added to a twin-screw extruder for melt extrusion. The extrusion temperatures were 145°C in zone 1, 160°C in zone 2, 170°C in zone 3, and 175°C at the die head. The screw speed was 140 rpm. After melt plasticization, the material was extruded and granulated to obtain polyvinyl chloride tape base material granules.

[0072] S3, Calendering

[0073] The obtained polyvinyl chloride tape base material granules were added to a calender for calendering. The calendering was carried out at 170°C with a roller linear speed of 10 m / min and a calendering time of 5 min. Then, the calendering was cooled and set at 30°C to obtain a polyvinyl chloride tape base film.

[0074] Performance testing:

[0075] 1. Test method for heat aging resistance

[0076] The polyvinyl chloride (PVC) tape base films prepared in the examples and comparative examples were cut into 100mm × 10mm samples with consistent thickness. The samples were placed in a forced-air constant-temperature aging chamber and subjected to heat aging treatment at 120℃ for 168 hours. After aging, the samples were removed and allowed to recover at room temperature for 2 hours. The changes in appearance were then observed, and the tensile strength was measured using an electronic universal testing machine. The tensile strength retention rate was calculated by comparing the changes in tensile strength before and after aging to evaluate the material's heat aging resistance in high-temperature environments.

[0077] 2. Tensile property test method

[0078] The polyvinyl chloride (PVC) tape base films obtained in the examples and comparative examples were cut into 100 mm × 10 mm specimens and subjected to tensile testing using an electronic universal testing machine. The clamp spacing was set to 50 mm, the tensile speed to 50 mm / min, and the tests were conducted at room temperature. The tensile strength and elongation at break of each specimen were recorded. Each group of samples was tested in parallel five times, and the average value was taken as the final test result to evaluate the mechanical properties of the material.

[0079] 3. Test method for heat resistance dimensional stability

[0080] The polyvinyl chloride tape base film obtained in the examples and comparative examples was cut into 50mm × 50mm samples. The initial length and width of the samples were recorded. The samples were then placed flat in a constant temperature oven and kept at 150°C for 30 minutes. After the samples were removed, they were cooled to a stable state at room temperature. The length and width of the samples were measured again. The thermal shrinkage rate was obtained by calculating the dimensional change rate of the samples before and after heating to evaluate the dimensional stability of the material under high temperature conditions.

[0081] 4. Electrical insulation performance test methods

[0082] The polyvinyl chloride (PVC) tape base films obtained in the examples and comparative examples were cut into 100mm × 100mm samples and placed at room temperature and 50% relative humidity for 24 hours for environmental equilibration. Then, insulation resistance testing was performed using an insulation resistance tester. The test voltage was set to 500V, and the test time was 60s. The volume resistivity of the samples was recorded. Each group of samples was tested three times, and the average value was taken as the final test result to evaluate the electrical insulation performance of the material.

[0083] Table 1 Performance Test Results

[0084]

[0085] As shown in Table 1, the high-temperature resistant PVC tapes prepared in Examples 1-3 are significantly superior to the comparative examples in terms of tensile strength and elongation at break. Figure 2Example 2 exhibited the highest tensile strength (27.3 MPa) and elongation at break (298%) among all samples, indicating that modification of polyvinyl chloride (PVC) via a dopamine-boronate-organosilicon synergistic network structure can form a more stable structural network within the material, effectively enhancing the interaction between molecular chains and improving the overall mechanical properties of the material. In contrast, Comparative Examples 1 and 2, employing only a single modification method, showed significantly lower tensile strength and elongation at break compared to the examples, demonstrating that a single modification structure is insufficient to achieve a stable synergistic reinforcement effect.

[0086] Regarding heat resistance and dimensional stability, the thermal shrinkage rates of Examples 1-3 were significantly lower than those of the comparative examples, with Example 2 exhibiting the lowest thermal shrinkage rate at only 2.6%. This indicates that by constructing a synergistic system of dopamine-boronate dynamic structure and organosilicon network structure, the movement of polyvinyl chloride molecular chains under high-temperature conditions can be effectively restricted, thereby significantly improving the dimensional stability of the material in high-temperature environments. In contrast, Comparative Examples 1 and 2, lacking the synergistic structure, showed thermal shrinkage rates of 5.6% and 5.1%, respectively, indicating that the materials are more prone to structural relaxation and dimensional changes under high-temperature conditions.

[0087] Regarding heat aging resistance, the tensile strength retention rates of Examples 1-3 were all above 90% or close to 90%, with Example 2 reaching 92.7%, demonstrating excellent heat aging resistance. This indicates that the present invention, by constructing a synergistic system of dynamic borate ester bonds and Si-O-Si network structure, can maintain the stability of the material structure under high-temperature conditions, thereby effectively slowing down the thermal degradation process of polyvinyl chloride. In contrast, the tensile strength retention rates of Comparative Examples 1 and 2 were significantly lower, indicating that a single modification method has limited effect on improving the heat resistance stability of the material.

[0088] Regarding electrical insulation properties, the volume resistivity of Examples 1-3 was significantly higher than that of the comparative example, with Example 2 reaching 3.1 × 10¹³ Ω·cm. This indicates that by introducing a synergistic modified structure and the organic small molecule diphenylphosphine oxide, the internal microstructure of the material can be further optimized, thereby improving its electrical insulation performance. Although Comparative Example 3 used synergistically modified polyvinyl chloride, its volume resistivity was still lower than that of the examples because it did not contain the organic small molecule diphenylphosphine oxide, demonstrating that this organic small molecule also plays an important role in improving the overall performance of the material.

[0089] In summary, by constructing a dopamine-boronate-organosilicon synergistic network structure and introducing diphenylphosphine oxide for synergistic regulation, the high-temperature resistant polyvinyl chloride tape prepared by this invention exhibits significant advantages in mechanical properties, heat resistance dimensional stability, heat aging resistance, and electrical insulation properties, with Example 2 showing the best overall performance.

Claims

1. A high-temperature resistant polyvinyl chloride tape, characterized in that, The raw materials include the following parts by weight: 70-120 parts of synergistically modified polyvinyl chloride; 0.5-6 parts of diphenylphosphine oxide; 5-20 parts of chlorinated polyethylene; 20-45 parts of diisononyl phthalate; 1-6 parts of antimony trioxide; 0.5-2 parts of calcium stearate; 0.5-2 parts of zinc stearate; 0.2-1 parts of antioxidant; and 0.1-1 parts of leveling agent. The synergistically modified polyvinyl chloride is obtained by introducing a catechol structure into polyvinyl chloride under the action of dopamine self-polymerization deposition, and further reacting it with 3-aminophenylboronic acid through dynamic borate ester bond interaction, while simultaneously constructing a Si-O-Si network structure through the condensation reaction of octa(3-aminopropyl)silsesquioxane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.

2. The high-temperature resistant polyvinyl chloride tape according to claim 1, characterized in that, The synergistically modified polyvinyl chloride comprises the following raw materials in parts by weight: 80-120 parts of polyvinyl chloride; 0.5-6 parts of dopamine; 0.3-4 parts of 3-aminophenylboronic acid; 0.5-5 parts of octa(3-aminopropyl)silsesquioxane; and 0.5-4 parts of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.

3. A high-temperature resistant polyvinyl chloride tape according to claim 1 or 2, characterized in that, The preparation method of the synergistically modified polyvinyl chloride includes the following steps: (1) Polyvinyl chloride was dispersed in a mixed solution of ethanol and deionized water, and then dopamine was added. The mixture was stirred and reacted under alkaline conditions to obtain surface-premodified polyvinyl chloride. (2) Add 3-aminophenylboronic acid to the surface-premodified polyvinyl chloride system to react and obtain boronic acid ester dynamically modified polyvinyl chloride; (3) Add octa(3-aminopropyl)silsesquioxane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane to the boronic acid ester dynamically modified polyvinyl chloride system and react them. After hydrolysis and condensation, an organosilicon network structure is constructed on the surface of polyvinyl chloride. After the reaction is completed, filter, wash and dry to obtain synergistically modified polyvinyl chloride.

4. The high-temperature resistant polyvinyl chloride tape according to claim 3, characterized in that, The reaction conditions for step (1) are: reaction temperature of 30-60℃, reaction time of 1-4h, system pH of 8-9, and stirring speed of 300-600rpm.

5. The high-temperature resistant polyvinyl chloride tape according to claim 3, characterized in that, The reaction conditions for step (2) are: reaction temperature of 40-70℃, reaction time of 1-3h, system pH of 7-9, and stirring speed of 300-600rpm.

6. The high-temperature resistant polyvinyl chloride tape according to claim 3, characterized in that, The reaction conditions for step (3) are a reaction temperature of 60-90℃, a reaction time of 2-5h, and a stirring speed of 300-700rpm.

7. The high-temperature resistant polyvinyl chloride tape according to claim 1, characterized in that, The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:(0.5-2); the leveling agent is a mixture of polyether-modified polydimethylsiloxane and polyacrylate leveling agent in a mass ratio of 1:(0.5-1.5).

8. A method for preparing a high-temperature resistant polyvinyl chloride tape, characterized in that, The preparation method includes the following steps: S1, synergistically modified polyvinyl chloride, diphenylphosphine oxide, and chlorinated polyethylene are mixed, and then diisononyl phthalate, calcium stearate, zinc stearate, antioxidant and leveling agent are added and mixed to obtain a premixed material; S2, the premixed material is melt-blended and extruded to obtain polyvinyl chloride tape base material granules; S3, calendering the PVC tape base material particles to obtain a high-temperature resistant PVC tape base film.

9. The method for preparing a high-temperature resistant polyvinyl chloride tape according to claim 8, characterized in that, The reaction conditions for step S1 are as follows: mixing is carried out in a high-speed mixer at a mixing temperature of 85–105°C, a mixing time of 8–15 min, a heating rate of 3–5°C / min, and a stirring speed of 400–700 rpm; the reaction conditions for step S2 are as follows: melt extrusion is carried out in a twin-screw extruder at an extrusion temperature of 140–150°C in zone 1, 150–165°C in zone 2, 165–175°C in zone 3, a die head temperature of 170–180°C, and a screw speed of 100–180 rpm.

10. The method for preparing a high-temperature resistant polyvinyl chloride tape according to claim 8, characterized in that, The reaction conditions for step S3 are as follows: calendering is performed in a calendering mill at a calendering temperature of 155–185°C, a roller linear speed of 5–15 m / min, a calendering time of 3–8 min, and a cooling and setting temperature of 20–40°C.

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