A high peel type adhesive tape and a method for manufacturing the same

Abstract

The application relates to a high-peeling adhesive tape and a preparation method thereof, and relates to the technical field of adhesive tape preparation.The high-peeling adhesive tape comprises a substrate layer, a reinforcing layer and a pressure-sensitive adhesive layer; the substrate layer comprises high-density polyethylene and linear low-density polyethylene; the reinforcing layer comprises an acrylate emulsion; the pressure-sensitive adhesive layer comprises an acrylic emulsion, hydrogenated rosin glyceride and epsilon-caprolactone blocked isocyanate; the preparation process comprises the steps of substrate layer preparation, reinforcing layer coating, pressure-sensitive adhesive layer formation and winding and slitting; the high-peeling adhesive tape and the preparation method thereof are characterized in that high-density polyethylene and low-density polyethylene are used as the substrate to prevent low-temperature cracking; the acrylate emulsion is used as the reinforcing layer to improve the interlayer bonding force and block moisture; the pressure-sensitive adhesive layer ensures low-temperature viscosity, interfacial adhesion and adhesive layer stability, thereby ensuring the stability of the peeling strength of the adhesive tape under low-temperature and high-humidity coupling conditions.

Description

Technical Field

[0001] This invention relates to the field of tape preparation technology, and in particular to a high-peel type tape and its preparation method. Background Technology

[0002] As a key material for bonding, protection, and fixation, tape has been widely used in various fields. At the same time, with the continuous development and progress of technology, the performance requirements of tape in various industries are becoming increasingly stringent, especially requiring tape to maintain stable peel performance in extreme environments in order to ensure assembly quality and product appearance.

[0003] Currently, conventional acrylic pressure-sensitive adhesive tapes on the market generally suffer from poor environmental compatibility. During long-term storage in humid heat or low-temperature storage and transportation, the adhesive layer is prone to a decrease in cohesive strength and a reduction in interfacial adhesion, resulting in a sudden increase or decrease in peel force. This not only easily leads to residual adhesive and delamination, but may also cause phenomena such as lifting and displacement.

[0004] To address the aforementioned issues, Chinese invention patent application CN121592263A, published on March 3, 2026, proposes a process for preparing a high peel stability adhesive tape. The tape comprises a corona-treated PET polyethylene terephthalate substrate, an acrylic pressure-sensitive adhesive layer, a release layer, and an antistatic liquid coating. The acrylic pressure-sensitive adhesive layer is composed of acrylate monomers, saturated polyester resin, bisphenol F and bisphenol A epoxy resin, and amino resin. The resulting tape exhibits excellent peel stability under high temperature, humidity, and low temperature conditions.

[0005] However, further research by the inventors revealed that the above-mentioned technical solution uses a PET film substrate, combined with an acrylic pressure-sensitive adhesive system optimized with bisphenol F, bisphenol A epoxy resin and amino resin. Under low temperature and high humidity coupling environment, the epoxy crosslinking network is prone to hydrolysis and chain segment freezing, resulting in a significant decrease in the wettability of the adhesive layer and the interfacial bonding force, ultimately causing drastic fluctuations in peel force. Summary of the Invention

[0006] To address the problem of insufficient peel stability of existing high-peel tapes under low-temperature and high-humidity coupling conditions, this invention provides a high-peel tape and its preparation method.

[0007] In a first aspect, the present invention provides a high-peel type adhesive tape, which adopts the following technical solution: A high-peel type adhesive tape includes a substrate layer, a reinforcing layer, and a pressure-sensitive adhesive layer; The substrate layer comprises, by mass parts: 60-80 parts of high-density polyethylene and 20-30 parts of linear low-density polyethylene. The reinforcing layer comprises, by way of composition: acrylate emulsion; The pressure-sensitive adhesive layer comprises, by weight parts: 40-60 parts of acrylic emulsion, 18-22 parts of hydrogenated rosin glycerol ester, and 6-8 parts of ε-caprolactone-blocked isocyanate.

[0008] By adopting the above technical solution, the mechanical strength, moisture resistance and dimensional stability of high-density polyethylene are used as the supporting skeleton of the tape to resist brittle fracture in low-temperature environments and avoid peeling failure caused by substrate cracking; the flexibility and processing fluidity of low-density polyethylene improve the low-temperature toughness of the substrate layer, ensuring that the substrate layer can still maintain its integrity in low-temperature and high-humidity environments and provide a stable base.

[0009] The reinforcing layer uses an acrylic emulsion, whose polar groups in its molecular structure form weak chemical bonds with the surface of the substrate layer. At the same time, it penetrates into the tiny pores on the surface of the substrate layer, forming an "anchoring effect" that enhances the interlayer adhesion between the substrate layer and the pressure-sensitive adhesive layer, preventing interlayer delamination under low temperature and high humidity conditions. In addition, the film formed after the acrylic emulsion is cured is water-resistant, preventing external moisture from penetrating to the interface between the substrate and the pressure-sensitive adhesive, reducing the damage of moisture to the interlayer adhesion, and alleviating the problem of decreased peel strength under high humidity conditions.

[0010] The acrylic emulsion in the pressure-sensitive adhesive layer has a low glass transition temperature, maintaining good adhesion and flexibility even at low temperatures. This solves the problem of existing pressure-sensitive adhesives hardening and losing adhesion at low temperatures, leading to difficult peeling. Hydrogenated rosin glycerol ester has good compatibility with acrylic emulsion molecules, improving the initial tack and holding power of the pressure-sensitive adhesive, enhancing the interfacial bonding between the pressure-sensitive adhesive and the adhered materials, such as bare steel in oil and gas pipelines and steel structures. Its hydrophobicity also reduces moisture residue at the interface. ε-caprolactone-blocked isocyanate gradually unblocks during drying, undergoing a cross-linking reaction with the hydroxyl groups in the acrylic emulsion molecules to form a three-dimensional network structure. This improves the mechanical strength, water resistance, and low-temperature stability of the pressure-sensitive adhesive layer, preventing swelling, softening, or cracking under low-temperature and high-humidity conditions. This ensures the overall peel stability of the tape and solves the problem of large fluctuations in peel strength and easy detachment of existing tapes under low-temperature and high-humidity coupling conditions.

[0011] Optionally, the substrate layer further includes 2-6 parts of alkyl phosphate modified nano-montmorillonite, the preparation method of which is as follows: Nano-montmorillonite is dispersed in an ethanol aqueous solution, heated for pre-swelling, and then alkyl phosphate is added. The mixture is then reacted at 50–70°C and pH 4–6 for 2–4 hours for intercalation grafting. After filtration, washing, and drying, the final product is obtained.

[0012] By adopting the above technical solution, utilizing the layered structure and specific surface area of ​​nano-montmorillonite, and after modification with alkyl phosphate esters, the interlayer hydrophilicity is replaced by hydrophobic alkyl chains, improving the hydrophobicity of nano-montmorillonite. This prevents moisture from penetrating into the substrate layer under low temperature and high humidity conditions, avoiding swelling and softening of the substrate layer due to water absorption, and thus preventing interlayer delamination. At the same time, phosphate ester groups are introduced on the surface of the modified nano-montmorillonite, forming coordination bonds and van der Waals forces with polyethylene molecules in the substrate layer, enhancing the dispersibility of nano-montmorillonite in the substrate layer, avoiding agglomeration, and ensuring that nano-montmorillonite is uniformly dispersed in the polyethylene matrix, playing a rigid supporting role. This further improves the mechanical strength and low-temperature toughness of the substrate layer, reduces the risk of brittle fracture of the substrate layer at low temperatures, and provides a more stable adhesion base for the reinforcing layer and pressure-sensitive adhesive layer.

[0013] In the preparation method, after the nano-montmorillonite is pre-swelled with an ethanol aqueous solution, the interlayer spacing is expanded, which is conducive to the intercalation and grafting of alkyl phosphates. Under the conditions of 50-70℃ and pH 4-6, the phosphate groups of alkyl phosphates undergo esterification reaction with the hydroxyl groups between the nano-montmorillonite layers to achieve stable grafting. This ensures that the modified nano-montmorillonite can maintain the advantages of the layered structure and is well compatible with the polyethylene substrate.

[0014] In addition, while modified nano-montmorillonite is hydrophobic, its polar groups on the surface can form a stronger interfacial interaction with the acrylate emulsion of the reinforcing layer, further improving the adhesion between the reinforcing layer and the substrate layer and reducing interlayer delamination under low temperature and high humidity conditions.

[0015] Optionally, the substrate layer further includes 4 to 6 parts of maleic anhydride-grafted polyethylene, wherein the grafting rate of the maleic anhydride-grafted polyethylene is 1.6 to 2.0 wt%.

[0016] By adopting the above technical solution, the polyethylene backbone in the molecular structure of maleic anhydride-grafted polyethylene has good compatibility with the high and low density polyethylene in the substrate layer, ensuring uniform dispersion in the substrate layer. The strong polarity of the maleic anhydride group reacts with the phosphate ester groups and hydroxyl groups on the surface of the modified nano-montmorillonite through acid-base reactions and hydrogen bonding, further improving the dispersibility of nano-montmorillonite in the substrate layer, avoiding uneven mechanical properties of the substrate layer caused by nano-montmorillonite agglomeration, and enhancing the internal bonding force of the substrate layer, reducing cracking and swelling of the substrate layer under low temperature and high humidity conditions.

[0017] In addition, the strong polarity of maleic anhydride groups forms hydrogen bonds and chemical bonds with the hydroxyl and carboxyl groups in the acrylate emulsion of the reinforcing layer, enhancing the interfacial bonding between the reinforcing layer and the substrate layer. When the grafting rate is too low, the number of maleic anhydride groups is insufficient, which cannot fully exert the role of interfacial bonding and dispersion of nano-montmorillonite. When the grafting rate is too high, the flexibility of maleic anhydride-grafted polyethylene will decrease, which will reduce the low-temperature toughness of the substrate layer and is not conducive to the peeling stability under low-temperature conditions. Furthermore, maleic anhydride-grafted polyethylene can also enhance the surface activity of the substrate layer, making it easier for the acrylate emulsion of the reinforcing layer to spread and wet the substrate layer surface, reducing bubbles and defects during the coating process, and further ensuring the coating quality of the reinforcing layer.

[0018] Optionally, the pressure-sensitive adhesive layer further includes 0.5 to 1.5 parts of diol ether ester.

[0019] By adopting the above technical solution, the diol ether ester molecule contains ether bonds, ester bonds and hydroxyl groups simultaneously, which has good compatibility with acrylic emulsion, hydrogenated rosin glycerol ester and ε-caprolactone blocked isocyanate in the pressure-sensitive adhesive layer. This improves the fluidity and coatability of the pressure-sensitive adhesive, allows the pressure-sensitive adhesive to spread evenly on the surface of the reinforcing layer, reduces coating defects, forms a continuous and dense pressure-sensitive adhesive layer, and avoids peel strength fluctuations caused by uneven adhesive layer.

[0020] In low-temperature environments, diol ether esters lower the glass transition temperature of the pressure-sensitive adhesive layer, further enhancing its low-temperature flexibility and maintaining good adhesion. Simultaneously, the hydrophobicity of diol ether esters further improves the water resistance of the pressure-sensitive adhesive layer, preventing external moisture from penetrating to the interface between the adhesive and the adhered material, thus reducing the damage to interfacial bonding caused by moisture. Furthermore, diol ether esters can promote the deblocking and cross-linking reaction of ε-caprolactone-blocked isocyanates, enabling the pressure-sensitive adhesive layer to form a more complete three-dimensional network structure, improving its mechanical strength and aging resistance, and preventing swelling, cracking, or loss of adhesion under low-temperature and high-humidity conditions.

[0021] Optionally, the pressure-sensitive adhesive layer further includes 0.05 to 0.15 parts of iron acetylacetone.

[0022] By adopting the above technical solution, iron acetylacetone is used to promote the deblocking reaction of ε-caprolactone-blocked isocyanate, reduce the deblocking temperature, and accelerate the crosslinking reaction rate, so that the pressure-sensitive adhesive layer forms a denser and more stable three-dimensional network structure during the drying process, thereby improving the peel stability of the tape. At the same time, the metal ions in iron acetylacetone can also form weak coordination bonds with the polar groups in the pressure-sensitive adhesive molecules, further enhancing the bonding force inside the pressure-sensitive adhesive layer.

[0023] In addition, iron acetylacetone improves the interfacial bonding between the pressure-sensitive adhesive layer and the adhered material, such as bare steel and steel structures. Its metal ions interact with the hydroxyl groups and oxide layer on the surface of the adhered material to form a stronger interfacial adsorption force and increase the interfacial viscosity under low temperature and high humidity conditions.

[0024] Optionally, the acrylic emulsion is a butyl acrylate-methyl methacrylate copolymer emulsion, wherein the glass transition temperature (Tg) of the butyl acrylate-methyl methacrylate copolymer emulsion is -35℃ to -25℃.

[0025] By adopting the above technical solution, the butyl acrylate-methyl methacrylate copolymer emulsion retains the low-temperature viscosity and flexibility of butyl acrylate, while possessing the water resistance and mechanical strength of methyl methacrylate. The limited glass transition temperature ensures that the pressure-sensitive adhesive layer can maintain good flexibility and viscosity in low-temperature environments, especially under the low-temperature conditions that oil and gas pipelines may face, thus avoiding peeling failure caused by the adhesive layer hardening and becoming brittle.

[0026] Secondly, the present invention provides a method for preparing a high-peel type adhesive tape, which adopts the following technical solution: A method for preparing a high-peel type adhesive tape includes the following steps: Substrate layer preparation: High-density polyethylene and linear low-density polyethylene are mixed evenly and melt-extruded to obtain the substrate layer; Reinforcing layer coating: A reinforcing layer is coated on the surface of the substrate layer and cured at room temperature; Forming a pressure-sensitive adhesive layer: Acrylic emulsion, hydrogenated rosin glycerol ester, and ε-caprolactone-blocked isocyanate are mixed to prepare a pressure-sensitive adhesive liquid, which is then coated onto the reinforcing layer and dried to form a pressure-sensitive adhesive layer. Rewinding and slitting: Rewinding and slitting to obtain high-peel type tape.

[0027] By adopting the above technical solution, the substrate layer is prepared using a melt extrusion molding process. The materials are mixed uniformly and then melt-extruded to ensure sufficient dispersion of each component, forming a uniform and dense substrate layer. Simultaneously, melt extrusion creates a certain roughness on the substrate layer surface, improving the adhesion of the reinforcing layer coating. The reinforcing layer coating uses a room-temperature curing process, leveraging its bridging role to further enhance the bonding force between the substrate layer and the pressure-sensitive adhesive layer, while also preventing moisture penetration and ensuring peel stability. In the step of forming the pressure-sensitive adhesive layer, the components are mixed to form a pressure-sensitive adhesive solution, which is then coated onto the reinforcing layer and dried to form a pressure-sensitive adhesive layer of uniform thickness. The drying process removes solvents and moisture from the adhesive solution, improving the mechanical strength and moisture resistance of the pressure-sensitive adhesive layer. The winding and slitting steps ensure the flatness of the tape during use, further guaranteeing the stability of peel performance.

[0028] Optionally, it also includes a low-temperature curing step, which is performed after the substrate layer preparation step and before the reinforcement layer coating step; The low-temperature curing steps are as follows: curing at 25-30℃ for 8-12 hours, then at 10-15℃ for 6-10 hours, and finally at 0-5℃ for 3-5 hours.

[0029] By adopting the above technical solution, the substrate layer is first cured at 25-30℃ to slowly release the thermal stress inside the substrate layer, avoiding deformation caused by stress concentration. At the same time, the molecular chains of the substrate layer are fully extended, improving the dimensional stability of the substrate layer and thus providing a stable substrate. Subsequently, the substrate layer is cured at 10-15℃ to further release residual stress, while reducing the surface tension of the substrate layer and improving surface activity. This makes it easier for the acrylic emulsion of the reinforcing layer to spread and wet the surface of the substrate layer, enhancing the interfacial adhesion. Finally, the substrate layer is cured at 0-5℃ to adapt to the low-temperature environment, further improving low-temperature toughness and ensuring the stability of the substrate layer performance.

[0030] Optionally, in the step of forming the pressure-sensitive adhesive layer, the drying method is as follows: first, slow drying at 25-30℃ for 40-60 minutes, then drying at 60-70℃ under a vacuum environment of -0.06 to -0.08 MPa for 15-20 minutes, and finally cooling to room temperature for 10-15 minutes.

[0031] By adopting the above technical solution, the adhesive layer is first slowly dried at 25-30℃ to gradually remove solvents and moisture from the pressure-sensitive adhesive, avoiding defects such as skin formation on the adhesive layer surface and the inability of internal solvents to escape, which would lead to bubbles and pores. This ensures that the adhesive layer is continuous and dense. Subsequently, it is dried in a vacuum environment. The high temperature accelerates the evaporation of residual solvents and moisture, while the vacuum environment lowers the boiling point of the solvents. At the same time, it effectively removes micro-bubbles and residual moisture inside the adhesive layer, ensuring that the adhesive layer is fully dried and has a dense structure. At the same time, this temperature range can promote the deblocking and cross-linking reaction of ε-caprolactone-blocked isocyanate, forming a tighter three-dimensional network structure, improving the mechanical strength, water resistance, and low-temperature stability of the pressure-sensitive adhesive layer, and preventing the adhesive layer from swelling and softening under low temperature and high humidity conditions. Finally, it is cooled to room temperature to prevent the adhesive layer from cracking and becoming brittle, further improving the interlayer bonding force.

[0032] Thirdly, this invention provides an application of a high-peel type adhesive tape, employing the following technical solution: A high-peel type tape as described in the first aspect or a high-peel type tape prepared by any of the preparation methods described in the second aspect is used for covering, sealing and fixing the outer wall of bare steel, steel structure or metal equipment of oil and gas pipelines under low temperature, humid or frosty conditions.

[0033] In summary, the present invention has at least one of the following beneficial technical effects: 1. By using high-density polyethylene and low-density polyethylene, the substrate layer can maintain its integrity in low-temperature and high-humidity environments, providing a stable base. The film formed after the acrylic emulsion of the reinforcing layer is cured has water resistance, reducing the damage of moisture to the interlayer bonding force. The ε-caprolactone-blocked isocyanate in the pressure-sensitive adhesive layer undergoes a cross-linking reaction with the hydroxyl groups in the acrylic emulsion molecules to form a three-dimensional network structure, which improves the mechanical strength, water resistance and low-temperature stability of the pressure-sensitive adhesive layer.

[0034] 2. By uniformly dispersing nano-montmorillonite in the polyethylene matrix, a rigid support is provided, further enhancing the mechanical strength and low-temperature toughness of the substrate layer, reducing the risk of brittle fracture at low temperatures, and providing a more stable adhesion base for the reinforcing layer and pressure-sensitive adhesive layer; the strong polarity of the maleic anhydride groups reacts with the phosphate ester groups and hydroxyl groups on the surface of the modified nano-montmorillonite through acid-base reactions and hydrogen bonding, enhancing the internal bonding force of the substrate layer and reducing cracking and swelling of the substrate layer under low temperature and high humidity conditions.

[0035] 3. By using diol ether esters to promote the deblocking and crosslinking reaction of ε-caprolactone-blocked isocyanate, a more complete three-dimensional network structure is formed in the pressure-sensitive adhesive layer, improving the mechanical strength and aging resistance of the pressure-sensitive adhesive layer and preventing swelling, cracking, or loss of tack under low temperature and high humidity conditions; by using acetylacetone iron to promote the deblocking reaction of ε-caprolactone-blocked isocyanate, the deblocking temperature is lowered and the crosslinking reaction rate is accelerated, thereby forming a denser and more stable three-dimensional network structure, thus improving the peel stability of the tape.

[0036] 4. By adopting low-temperature curing, the low-temperature toughness is further improved, thereby ensuring the stability of the substrate layer performance; drying in a vacuum environment and high temperature accelerate the evaporation of residual solvents and moisture, effectively removing micro-bubbles and residual moisture inside the adhesive layer, ensuring that the adhesive layer is fully dried and has a dense structure; at the same time, this temperature range can promote the formation of a tighter three-dimensional network structure to prevent the adhesive layer from cracking and becoming brittle, further improving the interlayer bonding force. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to the embodiments.

[0038] Unless otherwise specified, the experimental methods used in the embodiments of this application are conventional methods, and the materials used are commercially available unless otherwise specified.

[0039] Example 1: This example discloses a high-peel type adhesive tape and its preparation method.

[0040] 1. A high-peel type adhesive tape, comprising a substrate layer, a reinforcing layer, and a pressure-sensitive adhesive layer; The substrate layer comprises, by mass parts: 60 parts high-density polyethylene and 30 parts linear low-density polyethylene. The reinforcing layer comprises, by way of composition: acrylate emulsion; The pressure-sensitive adhesive layer comprises, by mass, 40 parts of acrylic emulsion, 22 parts of hydrogenated rosin glycerol ester, and 6 parts of ε-caprolactone-blocked isocyanate; the acrylic emulsion is a butyl acrylate-methyl methacrylate copolymer emulsion, wherein the glass transition temperature Tg of the butyl acrylate-methyl methacrylate copolymer emulsion is -30℃.

[0041] 2. Preparation method of high-peel type adhesive tape The preparation method of high-peel type adhesive tape includes the following steps: Substrate layer preparation: The above-mentioned high-density polyethylene and linear low-density polyethylene were put into a high-speed mixer and mixed at 2000 r / min for 15 min. The mixed raw materials were then fed into a twin-screw extruder, and the extrusion temperature was set to 160℃ (feed section), 175℃ (melting section), 180℃ (homogenization section), and 170℃ (die head section). The film was formed through a T-die and then cooled and shaped by a cooling roller at a temperature of 25℃ and a winding tension of 3 kgf to obtain a substrate layer with a thickness of 50 μm. Reinforcing layer coating: Using an anilox roller coating method, the acrylic emulsion is evenly coated on one side of the substrate layer with a coating thickness of 10μm, and cured at 25℃ for 20min to form a reinforcing layer. Forming the pressure-sensitive adhesive layer: Acrylic emulsion, hydrogenated rosin glycerol ester, and ε-caprolactone-blocked isocyanate are added to a mixing tank and stirred at 1500 r / min at room temperature for 30 min. After mixing evenly, the mixture is allowed to stand for degassing for 25 min to obtain the pressure-sensitive adhesive solution. The substrate layer coated with the reinforcing layer is drawn into a coating machine, and the unwinding tension is controlled at 1.0 kgf. The pressure-sensitive adhesive solution is coated on the surface of the reinforcing layer, away from the substrate layer, using a doctor blade coating method, with a coating thickness of 25 μm. Then, it is sent to a drying oven and dried at 80℃ for 35 min to form the pressure-sensitive adhesive layer. Rewinding and slitting: The above-mentioned composite layer material is fed into a winding machine with a winding tension of 20 kgf to form a large roll, which yields a high-peel type tape. It can then be slitted into different width specifications as needed.

[0042] In this embodiment, ① the high-density polyethylene has a density of 0.952 g / cm³. 3 ② Linear low-density polyethylene: density 0.920 g / cm³ 3 ③ Acrylic ester emulsion: solid content 48wt%, viscosity 1000±200mPa·s; ④ Butyl acrylate-methyl methacrylate copolymer emulsion, solid content 50wt%, butyl acrylate to methyl methacrylate mass ratio 7:3; ⑤ Hydrogenated rosin glycerol ester: softening point 80℃, acid value ≤10mgKOH / g; ⑥ ε-caprolactone blocked isocyanate, blocking temperature 80℃.

[0043] The tests mainly measure the peel strength at 180°C at room temperature, the peel strength at 180°C after low-temperature and high-humidity coupling treatment, the peel force retention rate after low-temperature and high-humidity coupling treatment, and the curling rate after low-temperature and high-humidity treatment.

[0044] (1) Peel strength at 180°C at room temperature (N / 25mm): reflects the basic bonding ability of the tape under normal use conditions; the test is based on GB / T 2792-2014 "Test method for peel strength of adhesive tape"; test method: cut tape samples with a width of 25mm and a length of 200mm, pre-treat for 7 days at 23±1℃ and 50±5%RH, attach the tape to a steel plate, Ra≤0.8μm, roll it twice with a 2kg roller at a speed of 10mm / s, place it for 20min, peel it at 180° at a speed of 300mm / min, record the average force of the 50mm stable section, peel strength = average force / sample width; (2) 180° peel strength (N / 25mm) after low temperature and high humidity coupling treatment: reflects the bonding stability of the tape under extreme working conditions of low temperature and high humidity; the test conditions are based on the method of GB / T 2423.3-2016 "Environmental test - Part 2: constant temperature and humidity test"; the test method is as follows: cut tape samples with a width of 25mm and a length of 200mm, place them in a constant temperature and humidity chamber of -20±1℃ and 85±5%RH for 7 days, take them out and place them at room temperature for 30min, and then perform the 180° peel strength test. The test method is the same as (1). (3) Peel strength retention rate after low temperature and high humidity coupling (%): This indicates the degree of attenuation of the peel strength of the tape under low temperature and high humidity conditions. The higher the retention rate, the more stable the cohesive strength of the adhesive layer and the interfacial adhesion, and the stronger the resistance to hydrolysis and chain segment freezing. The calculation formula is: Peel strength retention rate = Peel strength at 180° after low temperature and high humidity coupling treatment / Peel strength at 180° at room temperature × 100%; (4) Curling rate (%) after low temperature and high humidity treatment: to evaluate the weather resistance of the tape and the interface. The more severe the curling, the worse the dimensional stability of the substrate and the weaker the interlayer bonding force. It is more likely to debond at the interface under low temperature and high humidity coupling environment. Test basis: refer to GB / T 34712-2017 "Determination of Curling of Adhesive Tape"; Test method: cut a tape sample with a width of 25mm and a length of 200mm, attach the tape to the steel plate (Ra≤0.8μm), roll it back and forth twice with a 2kg roller at a speed of 10mm / s, place it for 20min, and then place it in a constant temperature and humidity chamber of -20±1℃ and 85±5%RH for 7 days. After taking it out, place it in a room temperature environment for 30min, and measure the curling length (L1) and effective length (L0). Curling rate after low temperature and high humidity treatment = L1 / L0×100%.

[0045] Example 2: This example discloses a high-peel type adhesive tape and its preparation method.

[0046] A high-peel type adhesive tape includes a substrate layer, a reinforcing layer, and a pressure-sensitive adhesive layer; The substrate layer comprises, by mass parts: 80 parts high-density polyethylene and 20 parts linear low-density polyethylene. The reinforcing layer comprises, by way of composition: acrylate emulsion; The pressure-sensitive adhesive layer comprises, by mass, 60 parts of acrylic emulsion, 18 parts of hydrogenated rosin glycerol ester, and 8 parts of ε-caprolactone-blocked isocyanate; the acrylic emulsion is a butyl acrylate-methyl methacrylate copolymer emulsion, wherein the glass transition temperature Tg of the butyl acrylate-methyl methacrylate copolymer emulsion is -30℃. Everything else is the same as in Example 1.

[0047] Example 3: This example discloses a high-peel type adhesive tape and its preparation method.

[0048] A high-peel type adhesive tape includes a substrate layer, a reinforcing layer, and a pressure-sensitive adhesive layer; The substrate layer comprises, by mass parts: 70 parts high-density polyethylene and 25 parts linear low-density polyethylene; The reinforcing layer comprises, by way of composition: acrylate emulsion; The pressure-sensitive adhesive layer comprises, by weight, 50 parts of acrylic emulsion, 20 parts of hydrogenated rosin glycerol ester, and 7 parts of ε-caprolactone-blocked isocyanate; the acrylic emulsion is a butyl acrylate-methyl methacrylate copolymer emulsion, wherein the glass transition temperature Tg of the butyl acrylate-methyl methacrylate copolymer emulsion is -30℃. Everything else is the same as in Example 1.

[0049] The test results of the high-peel type tapes used in Examples 1-3 are shown in Table 1: Table 1. Test results of Examples 1-3 detection indicators Example 1 Example 2 Example 3 Peel strength at 180°C (N / 25mm) 18.13 17.74 17.91 Peel strength at 180° after low-temperature and high-humidity coupling treatment (N / 25mm) 16.91 16.99 17.25 Peel force retention rate after low temperature and high humidity coupling (%) 93.27 95.77 96.31 Curling rate (%) after low temperature and high humidity treatment 1.32 1.18 1.21 Based on the test data from Examples 1-3, it can be seen that Example 1 has a slightly higher peel strength at room temperature. This is attributed to the higher proportion of hydrogenated rosin glycerol ester as the tackifying resin and the lower amount of ε-caprolactone-blocked isocyanate as the crosslinking agent. This results in a lower crosslinking density and more flexible chain segments, leading to more thorough wetting and spreading of the steel plate surface at room temperature and stronger interfacial adhesion, thus resulting in superior initial adhesion performance. However, the lower crosslinking density also weakens its resistance to hydrolysis and chain segment freezing under low temperature and high humidity, resulting in the lowest peel strength retention rate among the three. Example 2 has a better peel strength retention rate, possibly due to a more balanced ratio of hydrogenated rosin glycerol ester to blocked isocyanate, a moderate crosslinking density, and less cohesive attenuation under low temperature and high humidity. Example 3 exhibits the best substrate deformation resistance, adhesive wettability, and crosslinking stability, thus showing balanced performance in room temperature peel strength, low temperature and high humidity peel strength, retention rate, and warping rate, with no obvious weaknesses. Overall, the performance differences between Examples 1-3 are small and can meet practical application requirements.

[0050] Example 4: This example discloses a high-peel type adhesive tape and its preparation method.

[0051] In this embodiment, the substrate layer further includes 4 parts of alkyl phosphate modified nano-montmorillonite; the substrate layer comprises, by mass parts: 70 parts of high-density polyethylene, 25 parts of linear low-density polyethylene, and 4 parts of alkyl phosphate modified nano-montmorillonite. The preparation method of the alkyl phosphate modified nano-montmorillonite is as follows: 100 parts of nano-montmorillonite were dispersed in 2000 parts of ethanol-water solution, with a volume ratio of ethanol to water of 1:1. The dispersion was ultrasonically dispersed for 30 min at an ultrasonic power of 300 W and a frequency of 20 kHz. Then, the mixture was heated to 40 °C for pre-swelling for 2 h. 20 parts of alkyl phosphate were added, and the pH of the system was adjusted to 5.0 with 1 mol / L hydrochloric acid. The mixture was stirred at 60 °C for 3 h for intercalation grafting. After the reaction, the mixture was vacuum filtered. The filter cake was washed three times with ethanol-water solution of 1:1 (volume ratio of 400 parts each time). The cake was then placed in a vacuum drying oven and dried at 80 °C and -0.07 MPa for 8 h. Finally, the cake was pulverized to a particle size of 100 mesh to obtain the final product. Among them, ① nano-montmorillonite, with a particle size of 50±10nm; ② alkyl phosphate, model AP-18, with a carbon chain length of C18. In the preparation method of high peel type tape, when preparing the substrate layer, high-density polyethylene, linear low-density polyethylene and alkyl phosphate modified nano-montmorillonite are put into a high-speed mixer together, the mixing time remains unchanged, and the other steps and parameters remain unchanged. Everything else is the same as in Example 3.

[0052] Example 5: This example discloses a high-peel type adhesive tape and its preparation method.

[0053] In this embodiment, the substrate layer further includes 5 parts of maleic anhydride-grafted polyethylene, wherein the grafting rate of the maleic anhydride-grafted polyethylene is 1.8 wt%. The substrate layer comprises, by weight, 70 parts of high-density polyethylene, 25 parts of linear low-density polyethylene, 4 parts of alkyl phosphate modified nano-montmorillonite, and 5 parts of maleic anhydride grafted polyethylene. In the preparation method of high peel type tape, when preparing the substrate layer, high-density polyethylene, linear low-density polyethylene, alkyl phosphate modified nano-montmorillonite, and maleic anhydride grafted polyethylene are put into a high-speed mixer together, the mixing time remains unchanged, and the other steps and parameters remain unchanged. Everything else is the same as in Example 4.

[0054] Example 6: This example discloses a high-peel type adhesive tape and its preparation method.

[0055] In this embodiment, the pressure-sensitive adhesive layer further includes 1.0 part of diol ether ester; The pressure-sensitive adhesive layer comprises, by weight, 50 parts of acrylic emulsion, 20 parts of hydrogenated rosin glycerol ester, 7 parts of ε-caprolactone-blocked isocyanate, and 1.0 part of diol ether ester; wherein the diol ether ester is of type DBE-3. In the preparation method of high peel type adhesive tape, when forming pressure sensitive adhesive layer, acrylic emulsion, hydrogenated rosin glycerol ester, ε-caprolactone blocked isocyanate and diol ether ester are added into a stirring tank, the stirring time remains unchanged, and the other steps and parameters remain unchanged. Everything else is the same as in Example 5.

[0056] The test results of the high-peel type tapes used in Examples 4-6 are shown in Table 2: Table 2 Detection results of Examples 4-6 detection indicators Example 4 Example 5 Example 6 Peel strength at 180°C (N / 25mm) 18.12 18.33 18.62 Peel strength at 180° after low-temperature and high-humidity coupling treatment (N / 25mm) 17.49 17.72 18.02 Peel force retention rate after low temperature and high humidity coupling (%) 96.52 96.67 96.78 Curling rate (%) after low temperature and high humidity treatment 0.82 0.71 0.72 By comparing Example 4 with Example 3, it can be seen that Example 4 introduces alkyl phosphate modified nano-montmorillonite into the substrate. The modified montmorillonite is dispersed in the polyethylene matrix in an intercalated structure, which improves the barrier properties and dimensional stability of the substrate and inhibits moisture absorption and warping of the substrate under low temperature and high humidity. Therefore, the warping rate is significantly reduced. At the same time, the nanofiller slightly improves the surface roughness of the substrate and enhances the bonding force with the reinforcing layer. As a result, the peel strength after low temperature and high humidity is slightly better than that of Example 3, and the overall performance is better than that of Example 3.

[0057] By comparing Example 5 with Example 4, it can be seen that Example 5 further adds maleic anhydride-grafted polyethylene to the substrate. Its polar grafting groups enhance the interfacial compatibility between the polyethylene substrate and the acrylate reinforcement layer, while improving the dispersion uniformity of modified montmorillonite in the substrate and reducing agglomeration defects. This not only improves the overall bonding strength between the adhesive layer and the substrate, resulting in a slight increase in the peel strength at room temperature, but also further reduces the warping of the substrate under low temperature and high humidity conditions, with a slight decrease in the warping rate. The peel strength retention rate is slightly improved due to the enhanced interfacial stability.

[0058] By comparing Example 6 with Example 5, it can be seen that the addition of diol ether ester to the pressure-sensitive adhesive in Example 6 improves the miscibility of acrylic emulsion, hydrogenated rosin glycerol ester and blocked isocyanate, reduces the surface tension of the adhesive, improves the coating uniformity and the density of the cured adhesive layer, reduces the water penetration channels, and thus improves the peel strength at both room temperature and low temperature and high humidity, and increases the peel strength retention rate.

[0059] Example 7: This example discloses a high-peel type adhesive tape and its preparation method.

[0060] In this embodiment, the pressure-sensitive adhesive layer further includes 0.10 parts of iron acetylacetone; The pressure-sensitive adhesive layer comprises, by weight, 50 parts acrylic emulsion, 20 parts hydrogenated rosin glycerol ester, 7 parts ε-caprolactone blocked isocyanate, 1.0 part diol ether ester, and 0.10 parts acetylacetone iron. In the preparation method of high peel type adhesive tape, when forming pressure sensitive adhesive layer, iron acetylacetone is first added to acrylic emulsion, and ultrasonicated for 10 minutes under ultrasonic power of 200W and frequency of 20kHz. Then, hydrogenated rosin glycerol ester, ε-caprolactone blocked isocyanate and diol ether ester raw materials are added. Everything else is the same as in Example 6.

[0061] Example 8: This example discloses a high-peel type adhesive tape and its preparation method.

[0062] In this embodiment, in the method for preparing high-peel adhesive tape, a low-temperature curing step is set after the substrate layer preparation step and before the reinforcement layer coating step. The specific low-temperature curing step is as follows: The prepared substrate layer was placed in a constant temperature curing oven and cured at 28℃ for 10 hours, then at 12℃ for 8 hours, and finally at 3℃ for 4 hours. After curing, it was taken out. Everything else is the same as in Example 7.

[0063] Example 9: This example discloses a high-peel type adhesive tape and its preparation method.

[0064] In this embodiment, in the preparation method of high peel type adhesive tape, when forming pressure sensitive adhesive layer, the drying method is as follows: first, slow drying at 28°C for 50 min, then drying at 65°C and -0.07MPa vacuum environment for 18 min, and finally taking it out and cooling at room temperature 22.5±2.5°C for 12 min. Everything else is the same as in Example 8.

[0065] The test results of the high-peel type tapes used in Examples 7-9 are shown in Table 3: Table 3. Test results of Examples 7-9 detection indicators Example 7 Example 8 Example 9 Peel strength at 180°C (N / 25mm) 18.71 18.82 19.08 Peel strength at 180° after low-temperature and high-humidity coupling treatment (N / 25mm) 18.21 18.44 18.72 Peel force retention rate after low temperature and high humidity coupling (%) 97.33 97.98 98.11 Curling rate (%) after low temperature and high humidity treatment 0.61 0.52 0.41 By comparing Example 7 with Example 6, it can be seen that Example 7 introduces acetylacetone iron as a crosslinking promoting catalyst to promote the crosslinking reaction between ε-caprolactone-blocked isocyanate and acrylic emulsion, forming a more uniform and dense three-dimensional crosslinking network. This effectively inhibits the freezing of adhesive segments and interface hydrolysis and debonding under low temperature and high humidity, while improving the cohesive strength of the adhesive layer. Therefore, all performance indicators are improved.

[0066] By comparing Example 8 with Example 7, it can be seen that Example 8 adds a gradient low-temperature curing process, which eliminates the internal stress after the substrate is extruded and film-forming, makes the molecular chain arrangement of the substrate more regular, reduces the tendency of thermal expansion and contraction deformation under low temperature and high humidity environment, and improves the bonding strength between the reinforcing layer and the substrate, further reducing the risk of interface debonding and lifting, thus improving the peel force retention rate and reducing the lifting rate.

[0067] By comparing Example 9 with Example 8, it can be seen that Example 9 adjusts the drying process of the pressure-sensitive adhesive to avoid problems such as bubbles and pinholes caused by rapid drying of the adhesive layer. At the same time, it promotes the complete removal of residual moisture, making the adhesive layer more fully cross-linked, with higher cohesive strength and tighter interfacial bonding. Ultimately, the peel strength at room temperature, the peel strength after low temperature and high humidity, and the peel force retention rate are all optimal, and the curling rate is reduced to the lowest level.

[0068] Comparative Example 1: This comparative example discloses a high-peel type adhesive tape and its preparation method.

[0069] In this comparative example, the substrate layer was replaced with corona-treated PET polyethylene terephthalate substrate, the substrate layer thickness was 50 μm, and the corona treatment intensity was 42 dyn / cm; all other aspects were the same as in Example 3.

[0070] Comparative Example 2: This comparative example discloses a high-peel type adhesive tape and its preparation method.

[0071] In this comparative example, the raw material components of the pressure-sensitive adhesive layer are: 40 parts butyl acrylate, 30 parts 2-ethylhexyl acrylate, 15 parts methyl methacrylate, 10 parts saturated polyester resin, 5 parts bisphenol F epoxy resin, 4 parts bisphenol A epoxy resin, 3 parts amino resin, and 100 parts ethyl acetate. In the preparation method, only the pressure-sensitive adhesive layer raw material is replaced, while the remaining steps and process parameters remain unchanged; Everything else is the same as in Example 3.

[0072] Comparative Example 3: This comparative example discloses a high-peel type adhesive tape and its preparation method.

[0073] In this comparative example, a high-peel type tape includes a corona-treated PET polyethylene terephthalate substrate with a thickness of 50 μm and a corona treatment strength of 42 dyn / cm; the pressure-sensitive adhesive layer has the following components: 40 parts butyl acrylate, 30 parts 2-ethylhexyl acrylate, 15 parts methyl methacrylate, 10 parts saturated polyester resin, 5 parts bisphenol F epoxy resin, 4 parts bisphenol A epoxy resin, 3 parts amino resin, and 100 parts ethyl acetate. In the preparation method, the substrate layer is prepared by obtaining a corona-treated PET polyethylene terephthalate substrate; the reinforcement layer is coated in the same way as in Example 3; in the step of forming the pressure-sensitive adhesive layer, ε-caprolactone, 2-ethylhexyl acrylate, methyl methacrylate, saturated polyester resin, bisphenol F epoxy resin, bisphenol A epoxy resin, amino resin, and ethyl acetate are mixed, and other preparation steps and parameters are the same as in Example 3. Everything else is the same as in Example 3.

[0074] The high-peel type adhesive tapes prepared using Comparative Examples 1-3 were tested, and the results are shown in Table 4. Table 4. Results of indicator testing for comparative examples 1-3 detection indicators Comparative Example 1 Comparative Example 2 Comparative Example 3 Peel strength at 180°C (N / 25mm) 17.82 17.63 17.51 Peel strength at 180° after low-temperature and high-humidity coupling treatment (N / 25mm) 15.23 14.92 13.82 Peel force retention rate after low temperature and high humidity coupling (%) 85.47 84.63 78.93 Curling rate (%) after low temperature and high humidity treatment 3.81 1.52 4.21 By comparing Comparative Example 1 and Example 3, it can be seen that in Comparative Example 1, the PE substrate was replaced with a corona-treated PET substrate. The modulus of the PET substrate increased and its brittleness increased at low temperatures, resulting in increased interfacial stress. This led to warping and a decrease in peel strength. Furthermore, the interfacial bonding force with the acrylate reinforcement layer was weaker than that of the PE system, which made the interface prone to detachment under low temperature and high humidity. The peel strength retention rate decreased significantly, and the substrate warping deformation was severe, resulting in a significant increase in the warping rate. Only the peel strength at room temperature was close to that of Example 3.

[0075] By comparing Comparative Example 2 and Example 3, it can be seen that Comparative Example 2 uses a traditional acrylic pressure-sensitive adhesive system containing bisphenol F / A epoxy resin and amino resin. This system will cause the adhesive chain segments to freeze in a low-temperature environment, which will reduce the interface wettability. At the same time, the residual moisture at the interface will generate stress under temperature fluctuations, resulting in a decrease in peel force. Therefore, the peel strength and peel force retention rate after low temperature and high humidity are significantly lower than those of Example 3, and the peeling rate also increases due to the deterioration of the interface stability of the adhesive layer.

[0076] By comparing Comparative Example 3 and Example 3, it can be seen that Comparative Example 3 uses both PET substrate and epoxy modified acrylic pressure-sensitive adhesive, which superimposes the dual defects of substrate moisture absorption deformation and adhesive layer hydrolysis and chain segment freezing. Under low temperature and high humidity, not only does the substrate warp severely, but the adhesive layer interface also quickly debonds and fails, resulting in a significant decrease in peel force retention rate and a significant increase in warping rate. All performance aspects are far worse than those of Example 3.

[0077] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-peel type adhesive tape, characterized in that, Includes a substrate layer, a reinforcing layer, and a pressure-sensitive adhesive layer; The substrate layer comprises, by mass parts: 60-80 parts of high-density polyethylene and 20-30 parts of linear low-density polyethylene. The reinforcing layer comprises, by way of composition: acrylate emulsion; The pressure-sensitive adhesive layer comprises, by weight parts: 40-60 parts of acrylic emulsion, 18-22 parts of hydrogenated rosin glycerol ester, and 6-8 parts of ε-caprolactone-blocked isocyanate.

2. The high-peel type adhesive tape according to claim 1, characterized in that, The substrate layer further includes 2-6 parts of alkyl phosphate modified nano-montmorillonite, and the preparation method of the alkyl phosphate modified nano-montmorillonite is as follows: Nano-montmorillonite is dispersed in an ethanol aqueous solution, heated for pre-swelling, and then alkyl phosphate is added. The mixture is then reacted at 50–70°C and pH 4–6 for 2–4 hours for intercalation grafting. After filtration, washing, and drying, the final product is obtained.

3. The high-peel type adhesive tape according to claim 2, characterized in that, The substrate layer further includes 4 to 6 parts of maleic anhydride-grafted polyethylene, wherein the grafting rate of the maleic anhydride-grafted polyethylene is 1.6 to 2.0 wt%.

4. The high-peel type adhesive tape according to claim 3, characterized in that, The pressure-sensitive adhesive layer also includes 0.5 to 1.5 parts of diol ether ester.

5. The high-peel type adhesive tape according to claim 4, characterized in that, The pressure-sensitive adhesive layer also includes 0.05 to 0.15 parts of iron acetylacetone.

6. The high-peel type adhesive tape according to any one of claims 1-5, characterized in that, The acrylic emulsion is a butyl acrylate-methyl methacrylate copolymer emulsion, wherein the glass transition temperature (Tg) of the butyl acrylate-methyl methacrylate copolymer emulsion is -35℃ to -25℃.

7. A method for preparing a high-peel type adhesive tape according to any one of claims 1-6, characterized in that, Includes the following steps: Substrate layer preparation: High-density polyethylene and linear low-density polyethylene are mixed evenly and melt-extruded to obtain the substrate layer; Reinforcing layer coating: A reinforcing layer is coated on the surface of the substrate layer and cured at room temperature; Forming a pressure-sensitive adhesive layer: Acrylic emulsion, hydrogenated rosin glycerol ester, and ε-caprolactone-blocked isocyanate are mixed to prepare a pressure-sensitive adhesive liquid, which is then coated onto the reinforcing layer and dried to form a pressure-sensitive adhesive layer. Rewinding and slitting: Rewinding and slitting to obtain high-peel type tape.

8. The method for preparing the high-peel type adhesive tape according to claim 7, characterized in that, It also includes a low-temperature curing step, which is set after the substrate layer preparation step and before the reinforcement layer coating step; The low-temperature curing process is as follows: curing at 25-30℃ for 8-12 hours, then at 10-15℃ for 6-10 hours, and finally at 0-5℃ for 3-5 hours.

9. The method for preparing the high-peel type adhesive tape according to any one of claims 8, characterized in that, In the step of forming the pressure-sensitive adhesive layer, the drying method is as follows: first, slow drying at 25-30℃ for 40-60 minutes, then drying at 60-70℃ under a vacuum environment of -0.06 to -0.08MPa for 15-20 minutes, and finally cooling to room temperature for 10-15 minutes.

10. The application of a high-peel adhesive tape according to any one of claims 1-6, or a high-peel adhesive tape prepared by any one of claims 7-9, characterized in that, The tape is used for covering, sealing, and fixing the outer walls of bare steel, steel structures, or metal equipment of oil and gas pipelines under low temperature, humid, or frosty conditions.