High wear-resistant and low-VOC PET-based tape, preparation process and application

Abstract

The present invention discloses a highly wear-resistant and low-VOC PET-based adhesive tape, a preparation process and an application thereof. By spraying a polyurethane film on a PET substrate, not only the voltage resistance and wear resistance of the adhesive tape are significantly improved, but also the problem of insufficient voltage resistance due to air gaps in traditional PET woven fabric substrates is effectively solved, and the tape can withstand voltages above 3kV without breakdown. The barrier effect of the polyurethane film allows the VOC substances in the glue to be emitted only to the inside of the wiring harness, but not to the outside, thereby preventing the VOC substances from being emitted to the outside of the wiring harness assembly or the cockpit, effectively reducing the volatilization of the VOC substances in the acrylic glue, and improving the performance of the wiring harness and the entire vehicle. In the actual application of automotive wire protection, only one winding is required to meet the protection requirements, reducing the working hours, reducing the production and inventory management costs, while improving the air quality in the vehicle, and improving the comfort and driving experience of passengers.

Description

Technical Field

[0001] The present invention relates to the technical field of compositions based on polymer compounds, and in particular to a highly wear-resistant and low-VOC PET-based adhesive tape, a preparation process and an application thereof. Background Art

[0002] Automotive wires are divided into low-voltage wires and high-voltage wires. The outer packaging materials of automotive low-voltage wires need to be wear-resistant and voltage-resistant protective materials. PET cloth-based tape is a protective material woven from PET silk threads. It is often used in the outer packaging materials of automotive low-voltage wires to provide wear-resistant protection to prevent the wires from being worn due to vibration and other reasons during the life cycle of the car; 0.10mm thick PVC tape is often used to insulate the voltage resistance of automotive low-voltage wires; and 0.30mm or even thicker PVC tape, or a combination of corrugated tubes and 0.10mm thick PVC tape, are often used to deal with both wear-resistant and voltage-resistant protection. The protection of automotive high-voltage wires usually involves putting a corrugated tube with an opening in the length direction of the side on the outside of the high-voltage wire to provide wear-resistant protection, and then wrapping PVC tape around the outside of the corrugated tube to seal the corrugated tube while providing voltage-resistant protection. The wiring harnesses at different positions of automotive parts require various tapes and other wrapping materials to protect them. The tape products in the existing technology face VOC pollution problems due to the presence of glue. VOC refers to volatile organic compounds, which mainly come from the raw materials and additives in the production process of the product. They will release a certain amount of formaldehyde, acetaldehyde, toluene and other harmful gases, causing environmental pollution and affecting health.

[0003] Cloth-based tape is a textile product. Although it can provide good wear resistance, no matter how densely it is woven, there are air gaps and it cannot meet the performance requirements of high voltage resistance. 0.10mm thick PVC can only play a role in restraining wires and withstanding voltage, and cannot provide wear protection. Although 0.30mm or even thicker PVC tape can provide both wear and voltage protection, its thickness makes it difficult for workers to wind the wire harness during production. The end of the winding also needs to be wrapped with a thin PVC tape to avoid warping. The use of corrugated tubes and 0 .10mm thick PVC tape combination is often used to deal with both wear-resistant and voltage-resistant protection; using corrugated tubes and PVC tape at the same time increases material costs and working hours. In the production process, the corrugated tube must be installed first and then the tape is wrapped. Because the corrugated tube material is hard, the flexibility of the entire wiring harness becomes poor. The wiring harness in the engine compartment of the car has many branches and the wiring harness layout is complex. The poor flexibility of the wiring harness makes it very difficult to assemble the final assembly, especially in winter. Some automobile factories heat the wiring harness at a certain temperature before performing the final assembly, but this will increase costs. With the rapid development of China's new energy technology and the continuous innovation of hybrid or electric drive technology, the space in the engine compartment is becoming more and more compact and crowded. The high-voltage wire harness on new energy vehicles needs to be protected by a higher voltage-resistant and high-wear-resistant tape to ensure the safety of the high-voltage wires during the life cycle of the car. Therefore, the protection of automotive wires urgently needs a composite functional tape that is both wear-resistant and voltage-resistant.

[0004] CN106398072A discloses an electrical tape base material and a calendering method thereof, which comprises the following components by weight: 80-110 parts of acrylic resin, 20-30 parts of low-density polyethylene, 10-20 parts of filler, 70-90 parts of plasticizer, 2-4 parts of foaming agent, 2-4 parts of potassium-zinc composite liquid stabilizer, 1-2 parts of lubricant, 3-4 parts of flame retardant and 10-20 parts of softener; the flame retardant comprises the following components by weight: 3-4 parts of perchlorocyclopentane, 1-2 parts of vinyl chloride-methyl methacrylate copolymer and 3-4 parts of platinum dichloride; the softener comprises the following components by weight: 5-8 parts of liquid paraffin, 3-4 parts of silicone oil, 1-2 parts of nano titanium dioxide and 1-2 parts of N-hydroxymethyl octadecylamide. The steps include mixing, extrusion molding, calendering molding and automatic cutting. The invention has good flame retardant effect, good environmental protection, good elasticity, strong toughness, not easy bending, easy to use, and uniform leather.

[0005] CN114605902A discloses a highly wear-resistant PU coating and its application. The purpose of the invention is to provide a PU-coated modified PET film and a tape containing the same, which have the advantages of excellent wear resistance, excellent peeling performance and low cost. The tape is a wiring harness tape, in which the PU coating and the glue layer are respectively located on the two main surfaces of the PET film, and the glue layer is obtained by coating an adhesive selected from the following group: an emulsion type polyacrylic acid adhesive, a hot melt type polyacrylate adhesive, a solvent type polyacrylate adhesive, or a combination thereof. The wiring harness tape of the invention is used for bundling, fixing and protecting the wires used in the wiring harness of the automotive industry.

[0006] The solutions reported in the above patent documents cannot solve the problems of voltage resistance, wear resistance and VOC content control at the same time. Therefore, it is urgent to prepare a PET substrate tape that has the advantages of wear resistance, voltage resistance and VOC content control. Summary of the invention

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to improve the wear resistance and voltage resistance of the PET base tape, so that the voltage resistance performance reaches above 3kV, and at the same time improve the VOC performance of the wiring harness and the whole vehicle, and effectively prevent the volatilization of harmful substances in the glue.

[0008] To achieve the above-mentioned purpose, the present invention provides a highly wear-resistant and low-VOC PET-based adhesive tape, a preparation process and an application thereof.

[0009] A method for preparing a highly wear-resistant and low-VOC PET substrate tape comprises the following steps:

[0010] (1) Gluing: applying acrylic glue on the polyurethane film of the polyurethane-PET substrate and drying the glue to obtain an acrylic glue layer;

[0011] (2) Rewinding: attaching the release film Film to the acrylic adhesive layer in step (1), then rolling it up to obtain a large mother roll, and leaving it for 24-48 hours;

[0012] (3) Rewinding: Unrolling the large mother roll, tearing off the release film, and rewinding into a small mother roll;

[0013] (4) Slitting: Slitting the small mother roll to obtain the highly wear-resistant and low-VOC PET substrate tape.

[0014] The amount of acrylic glue used in step (1) is 8-12 g / m 2 .

[0015] The drying step in step (1) is 6-stage drying, with a total drying time of 4-8 hours, and the specific temperature of each stage is as follows:

[0016] Level 1: 35-45℃;

[0017] Level 2: 65-70℃;

[0018] Level 3: 90-95°C;

[0019] Level 4: 90-95°C;

[0020] Level 5: 65-70℃;

[0021] Level 6: 35-45℃.

[0022] The polyurethane-PET substrate in step (1) is prepared by the following method:

[0023] M1. Melting polyurethane plastic particles;

[0024] M2, sprayed on PET substrate, the spraying thickness is 0.005-0.015mm;

[0025] M3. Dry at 50-70° C. for 2-4 hours to obtain the polyurethane-PET substrate with a lower layer being a PET substrate and an upper layer being a polyurethane film.

[0026] The plastic particles in step M1 are modified polyurethane plastic particles. The preparation method of the modified polyurethane plastic particles is as follows:

[0027] Microcrystalline cellulose is dispersed in anhydrous ethanol and mixed with bis(γ-triethoxysilylpropyl)tetrasulfide and acetic acid, filtered and washed to obtain modified microcrystalline cellulose, and the modified microcrystalline cellulose is mixed with polyurethane and melt-granulated to obtain the modified polyurethane plastic particles.

[0028] Preferably, the preparation method of the modified polyurethane plastic particles is as follows:

[0029] Disperse microcrystalline cellulose in anhydrous ethanol, add bis(γ-triethoxysilylpropyl)tetrasulfide and acetic acid, stir at room temperature for 2-6 hours, filter, wash the filter cake 2-3 times with anhydrous ethanol, air-dry at 50-70°C for 2-6 hours to obtain modified microcrystalline cellulose, mix the modified microcrystalline cellulose with polyurethane plastic particles, and melt granulate at 100-200°C to obtain the modified polyurethane plastic particles.

[0030] The weight ratio of the microcrystalline cellulose, anhydrous ethanol, bis(γ-triethoxysilylpropyl)tetrasulfide and acetic acid is 8-12:200-300:4-6:0.5-1.5.

[0031] The weight ratio of the modified microcrystalline cellulose and the polyurethane plastic particles is 8-12:1000-1800.

[0032] Preferably, the bis(γ-triethoxysilylpropyl)tetrasulfide can also be replaced by other sulfur-containing silanes, such as 3-thiocyanatopropyltriethoxysilane. In addition, a mixture of bis(γ-triethoxysilylpropyl)tetrasulfide and 3-thiocyanatopropyltriethoxysilane can also be used.

[0033] The present invention also provides a high wear-resistant and low-VOC PET substrate tape, which is composed of three layers of materials, namely, a PET substrate, a polyurethane film and an acrylic adhesive, and is prepared by the above method. The PET substrate is any one of a black PET substrate and an orange PET substrate.

[0034] The highly wear-resistant and low-VOC PET substrate adhesive tape of the present invention can be applied to the protection of automobile electric wires, including automobile low-voltage electric wire protection and automobile high-voltage electric wire protection.

[0035] The high wear-resistant VOC PET substrate tape in the present invention is a three-layer composite substrate composed of a PET substrate, polyurethane plastic particles, and acrylic glue, which meets the requirements of high wear resistance, voltage resistance, and low VOC emissions. The present invention selects black and orange, which are commonly used colors in the industry, for the PET substrate, and sprays a polymer material polyurethane, i.e., a polyurethane film, formed by polycondensation reaction of polyols and polyisocyanates on the PET substrate, effectively solving the problem of insufficient voltage resistance performance of traditional PET woven fabric substrates due to air gaps. The characteristics of polyurethane plastic particles are between plastic and rubber, and have the advantages of light weight, high wear resistance, low temperature resistance, aging resistance, excellent oil resistance, high tensile strength and toughness. Attaching a polyurethane film to a PET textile fabric substrate can not only improve the voltage resistance performance of the substrate, so that it can withstand a voltage of more than 3kV without breakdown, but also enhance the wear resistance of the tape, improve the wear resistance of the tape through the elasticity and wear resistance of polyurethane, absorb and disperse friction, and the wear resistance is significantly higher than that of a PET substrate tape without spraying a polyurethane film. The barrier effect of the polyurethane film also significantly reduces the volatilization of harmful substances in the acrylic glue in the tape, effectively controls the VOC content, and improves the environmental performance of the product.

[0036] The volatilization of volatile organic compounds (VOC) from the glue in the tape can cause certain harm to health, such as headaches, dizziness, nausea, vomiting and other discomfort symptoms. In the application of automobile wire protection, the volatilization of VOC may also cause odor in the car, affecting the comfort and driving experience of passengers. The acrylic glue layer and the PET substrate layer in the high wear-resistant low-VOC tape of the present invention are blocked by a polyurethane film, so that the VOC substances in the glue can only be emitted to the inside of the wire harness, and cannot be emitted to the outside, thereby preventing the emission to the outside of the wire harness assembly or the cockpit. The VOC substances in the acrylic glue are effectively prevented from being emitted, which has the effect of improving the VOC of the wire harness and the car cockpit.

[0037] According to industry practice, conventional tapes are wound with 50% of the tape width overlapped when applied, and 2 to 3 layers of overlapped winding are completed when approaching the connector. In the actual application of automotive wire protection, multi-layer winding mainly causes the tape to wear more severely, especially at the edge, affecting its durability, and the overlapping winding method has low operating efficiency, increasing working hours and production costs. The highly wear-resistant and low-VOC PET-based tape of the present invention can meet the protection needs of different automotive wire protection application scenarios by winding once, effectively reducing the working hours and reducing the number of varieties, which can effectively reduce the procurement and warehouse management costs of enterprises.

[0038] Beneficial effects of the present invention:

[0039] 1. Improve voltage resistance: By spraying the high molecular material polyurethane, i.e. polyurethane film, formed by the polycondensation reaction of polyols and polyisocyanates on the PET substrate, the problem of insufficient voltage resistance caused by air gaps in traditional PET fabric substrates is effectively solved, and the PET substrate can withstand voltages above 3kV without breakdown.

[0040] 2. Improve wear resistance: The PET base tape of the present invention is sprayed with a polyurethane film, and the elasticity and wear resistance of the polyurethane are utilized to improve the wear resistance of the tape, absorb and disperse friction. The wear resistance of the PET base tape sprayed with a polyurethane film is significantly higher than that of the PET base tape not sprayed with a polyurethane film.

[0041] 3. Controlling VOC content: The acrylic glue layer and the PET substrate layer in the high wear-resistant low-VOC tape of the present invention are separated by a polyurethane film, so that the VOC substances in the glue can only be emitted to the inside of the wire harness, but not to the outside, thereby preventing them from being emitted to the outside of the wire harness assembly or the cockpit. The VOC substances in the acrylic glue are effectively prevented from being emitted, which improves the VOC content of the wire harness and the car cockpit. The VOC content is effectively controlled, and the environmental performance of the product is improved.

[0042] 4. Reduce working hours and reduce costs: When conventional tapes are used, 50% of the tape width is overlapped and wound, and 2 to 3 layers of overlapped winding are completed when approaching the connector. In the actual application of automotive wire protection, multi-layer winding mainly causes the tape to wear more severely, especially at the edge, affecting its durability, and the overlapping winding method has low working efficiency, increasing working hours and production costs. The highly wear-resistant and low-VOC PET-based tape of the present invention can meet the protection requirements of different automotive wire protection application scenarios by winding once, effectively reducing the working hours and reducing the number of varieties, which can effectively reduce the procurement and warehouse management costs of enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the composition of the highly wear-resistant and low-VOC PET substrate tape of the present invention.

[0044] Figure 2 It is a schematic diagram of the preparation method of the high wear-resistant and low-VOC PET substrate tape of the present invention.

[0045] Figure 3 This is the polyurethane-PET substrate spraying process of the present invention.

[0046] Figure 4 It is a schematic diagram of the wiring harness winding of the present invention.

[0047] Figure 5 It is a schematic diagram of the ball-plate electrode device in Test Example 1 of the present invention.

[0048] Figure 6 It is a schematic diagram of the sample state in the wear resistance test in Test Example 2 of the present invention.

[0049] Figure 7 It is a schematic diagram of the scraping test device in Test Example 2 of the present invention. DETAILED DESCRIPTION

[0050] The parameters of the specific chemical substances used in the examples are from the following sources:

[0051] PET substrate: black PET substrate, weight 240g / m 2 The manufacturer is Changshu Haoxin Fiber Products Co., Ltd. and the product number is 23725-4.

[0052] Polyurethane plastic particles: American Lubrizol TPUESTANET 460A polyurethane is selected.

[0053] Acrylic glue: The manufacturer is Shenzhen Dekun Electronic Technology Co., Ltd., model is DK-550.

[0054] Release film Film: The base material is polyester film (PET), the manufacturer is Shanghai Ruizhi Industrial Co., Ltd., the product number is 001.

[0055] Bis(γ-triethoxysilylpropyl)tetrasulfide: CAS: 40372-72-3.

[0056] The specific temperatures of the 6-stage oven in step (1) of the following embodiments and comparative examples are as follows: stage 1: 40°C; stage 2: 70°C; stage 3: 90°C; stage 4: 95°C; stage 5: 70°C; stage 6: 40°C.

[0057] Example 1

[0058] A highly wear-resistant and low-VOC PET-based adhesive tape is composed of three layers of materials, including: a PET substrate, a polyurethane film, and an acrylic adhesive; the PET substrate is a black PET substrate. The specific structure is as follows Figure 1 shown.

[0059] Specifically, the preparation method of the highly wear-resistant and low-VOC PET substrate tape is as follows: Figure 2 As shown, the following steps are included:

[0060] (1) Gluing: melt the polyurethane plastic particles at 150° C.; spray them evenly on the PET substrate using a spray gun, with a spray thickness of 0.01 mm; dry at 60° C. for 4 hours to obtain the polyurethane-PET substrate with a PET substrate as the lower layer and a polyurethane film as the upper layer; apply 10 g / m 2 The acrylic glue is applied to the polyurethane film on the polyurethane-PET substrate, and then baked in an oven for 6 levels for 1 hour each, and the glue is dried for a total of 6 hours to obtain an acrylic glue layer; the polyurethane-PET substrate spraying process is as follows Figure 3 As shown; the acrylic glue layer and the PET substrate layer are blocked by a polyurethane film (see the wiring harness winding diagram in the accompanying drawing of the specification) Figure 4 );

[0061] (2) Rewinding: attaching a transparent release film to the acrylic adhesive layer in step (1), and then rolling it up to obtain a large mother roll, which is left for 24 hours to ensure that the glue is completely and reliably attached to the polyurethane film of the polyurethane-PET substrate;

[0062] (3) Rewinding: Unrolling the large mother roll, tearing off the release film, and rewinding into a small mother roll;

[0063] (4) Slitting: Slitting the small mother roll into tapes with a width of 25 mm to obtain the highly wear-resistant and low-VOC PET-based tape.

[0064] Comparative Example 1

[0065] A method for preparing a highly wear-resistant and low-VOC PET substrate tape comprises the following steps:

[0066] (1) Glue coating: 10g / m 2 The amount of acrylic glue is applied on the PET substrate, and then baked in a 6-stage oven for 1 hour at each stage, and the glue is dried for a total of 6 hours to obtain an acrylic glue layer;

[0067] (2) Rewinding: Attach a transparent release film to the acrylic adhesive layer in step (1), then rewind to obtain a large mother roll, and leave it for 24 hours to ensure that the glue is completely and reliably attached to the PET substrate;

[0068] (3) Rewinding: Unrolling the large mother roll, tearing off the release film, and rewinding into a small mother roll;

[0069] (4) Slitting: Slitting the small mother roll into tapes with a width of 25 mm to obtain the highly wear-resistant and low-VOC PET-based tape.

[0070] Example 2

[0071] A highly wear-resistant and low-VOC PET-based adhesive tape is composed of three layers of materials, including: a PET substrate, a polyurethane film, and an acrylic adhesive; the PET substrate is a black PET substrate. The specific structure is as follows Figure 1 shown.

[0072] Specifically, the preparation method of the highly wear-resistant and low-VOC PET substrate tape is as follows: Figure 2 As shown, the following steps are included:

[0073] (1) Gluing: melt the modified polyurethane plastic particles at 150°C; spray them evenly on the PET substrate using a spray gun, with a spray thickness of 0.01 mm; dry at 60°C for 4 hours to obtain the polyurethane-PET substrate with a PET substrate as the lower layer and a polyurethane film as the upper layer; apply 10 g / m 2 The acrylic glue is applied to the polyurethane film on the polyurethane-PET substrate, and then baked in an oven for 6 levels for 1 hour each, and the glue is dried for a total of 6 hours to obtain an acrylic glue layer; the polyurethane-PET substrate spraying process is as follows Figure 3 As shown; the acrylic glue layer and the PET substrate layer are blocked by a polyurethane film (see the wiring harness winding diagram in the accompanying drawing of the specification) Figure 4 );

[0074] (2) Rewinding: attaching a transparent release film to the acrylic adhesive layer in step (1), and then rolling it up to obtain a large mother roll, which is left for 24 hours to ensure that the glue is completely and reliably attached to the polyurethane film of the polyurethane-PET substrate;

[0075] (3) Rewinding: Unrolling the large mother roll, tearing off the release film, and rewinding into a small mother roll;

[0076] (4) Slitting: Slitting the small mother roll into tapes with a width of 25 mm to obtain the highly wear-resistant and low-VOC PET-based tape.

[0077] The preparation method of the modified polyurethane plastic particles is as follows:

[0078] 10 g of microcrystalline cellulose was mixed with 1500 g of polyurethane plastic particles, and melt-granulated at 150° C. to obtain modified polyurethane plastic particles with a particle size of 8 mm.

[0079] Example 3

[0080] A highly wear-resistant and low-VOC PET-based adhesive tape is composed of three layers of materials, including: a PET substrate, a polyurethane film, and an acrylic adhesive; the PET substrate is a black PET substrate. The specific structure is as follows Figure 1 shown.

[0081] Specifically, the preparation method of the highly wear-resistant and low-VOC PET substrate tape is as follows: Figure 2 As shown, the following steps are included:

[0082] (1) Gluing: melt the modified polyurethane plastic particles at 150°C; spray them evenly on the PET substrate using a spray gun, with a spray thickness of 0.01 mm; dry at 60°C for 4 hours to obtain the polyurethane-PET substrate with a PET substrate as the lower layer and a polyurethane film as the upper layer; apply 10 g / m 2 The acrylic glue is applied to the polyurethane film on the polyurethane-PET substrate, and then baked in an oven for 6 levels for 1 hour each, and the glue is dried for a total of 6 hours to obtain an acrylic glue layer; the polyurethane-PET substrate spraying process is as follows Figure 3 As shown; the acrylic glue layer and the PET substrate layer are blocked by a polyurethane film (see the wiring harness winding diagram in the accompanying drawing of the specification) Figure 4 );

[0083] (2) Rewinding: attaching a transparent release film to the acrylic adhesive layer in step (1), and then rolling it up to obtain a large mother roll, which is left for 24 hours to ensure that the glue is completely and reliably attached to the polyurethane film of the polyurethane-PET substrate;

[0084] (3) Rewinding: Unrolling the large mother roll, tearing off the release film, and rewinding into a small mother roll;

[0085] (4) Slitting: Slitting the small mother roll into tapes with a width of 25 mm to obtain the highly wear-resistant and low-VOC PET-based tape.

[0086] The preparation method of the modified polyurethane plastic particles is as follows:

[0087] Disperse 10 g of microcrystalline cellulose in 250 g of anhydrous ethanol, add 5 g of bis(γ-triethoxysilylpropyl)tetrasulfide and 1 g of acetic acid, stir at room temperature for 4 hours, filter, wash the filter cake twice with anhydrous ethanol, air-dry at 60°C for 4 hours to obtain modified microcrystalline cellulose, mix 10 g of modified microcrystalline cellulose with 1500 g of polyurethane plastic particles, and melt granulate at 150°C to obtain modified polyurethane plastic particles with a particle size of 8 mm.

[0088] Test Example 1

[0089] Voltage Withstand Test

[0090] Take 4 groups of 20 mm long PET substrate tape samples obtained by the preparation methods of Examples 1-3 and Comparative Example 1, and set 3 parallel samples in each group. The test procedure is based on JIS C2110 1 "Solid electrical insulating materials - Test method for breakdown strength - Part 1: Test with applied commercial frequency alternating voltage" 5 Electrodes and test pieces 5.2.1.3 Ball-plate electrode, the ball-plate electrode device schematic diagram is as follows Figure 5 As shown, the electrodes are composed of metal balls and metal plates. The upper electrode is set to a sphere with a diameter of 20 mm; the lower electrode is a circular plate with a diameter of 25 mm at the edge end, and the offset of the central axes of the upper and lower electrodes is within 1 mm.

[0091] The tape sample is placed between electrodes with a pressure of 4.9N. The voltage is raised to AC2500V, AC2800V, AC3000V, AC3200V, and AC3500V respectively to test whether the tape sample can remain undamaged for 1 minute under this voltage. If it does not break within 1 minute, it is determined that the tape sample has voltage resistance under this voltage. The test data is summarized in Table 1.

[0092] Table 1 Voltage Withstand Test Results

[0093] Example Withstand voltage strength Example 1 AC3000V Comparative Example 1 AC2500V Example 2 AC3200V Example 3 AC3500V

[0094] Microcrystalline cellulose is an inorganic compound. It is a microcrystalline powder obtained by acid hydrolysis and hydroxymethylation of cellulose. It has a large specific surface area and porosity. Since it contains a large number of hydroxyl groups on the surface, the particles will agglomerate through hydrogen bond interactions and become unevenly dispersed. The acetic acid catalyst is used to adjust the pH value and promote the dissolution of bis(γ-triethoxysilylpropyl)tetrasulfide. The silanols produced by the hydrolysis reaction will undergo a dehydration condensation reaction with the hydroxyl groups on the surface of the microcrystalline cellulose. Anhydrous ethanol is used as a solvent to disperse the microcrystalline cellulose to form a uniform dispersion, which is helpful for subsequent modifications. Bis(γ-triethoxysilylpropyl)tetrasulfide is a sulfur-containing silane containing a sulfur chain and a symmetrical bisilane structure. In Example 3, microcrystalline cellulose and polyurethane plastic particles are grafted by condensing bis(γ-triethoxysilylpropyl)tetrasulfide with microcrystalline cellulose and vulcanizing polyurethane at the same time. The modified polyurethane plastic particles obtained are compared with Example 2 in which microcrystalline cellulose and polyurethane plastic particles are directly melt-granulated. When the modified polyurethane plastic particles are used to make the polyurethane-PET substrate with a PET substrate as the lower layer and a polyurethane film as the upper layer, the adhesion of the polyurethane layer to the PET substrate is improved, and the bonding strength between the polyurethane layer and the acrylic adhesive layer is enhanced, so that the acrylic adhesive layer of the tape is more firmly combined with the PET substrate structure.

[0095] In Test Example 1, the difference between Example 1 and Comparative Example 1 is whether the polyurethane film is sprayed. The PET substrate in the PET substrate tape of Comparative Example 1 is a woven substrate. During the high voltage resistance test, breakdown will occur through the gaps, and the voltage resistance performance is lower than 3kV. The substrate after spraying the polyurethane film in Example 1 can withstand a voltage of more than 3kV, which solves the problem of low voltage resistance caused by the presence of air gaps in woven substrates, and no breakdown occurs under a voltage resistance of 3kV. In Example 2, microcrystalline cellulose is added to polyurethane for spraying into a film. The addition of microcrystalline cellulose increases the density of the substrate and improves the dielectric properties to a certain extent, helping to improve the pressure resistance of the tape; the risk of local discharge is reduced by reducing air gaps, the dielectric strength of the PET substrate is enhanced to improve stability, and the tape is less likely to break under voltage shocks through its enhanced mechanical properties. In Example 3, modified microcrystalline cellulose is added to polyurethane and sprayed into a film, wherein the Si-O-Si network structure formed by the hydrolysis of bis(γ-triethoxysilylpropyl)tetrasulfide is coated on the surface of the microcrystalline cellulose molecules as a protective layer. The prepared polyurethane-PET substrate enhances the bonding strength between the polyurethane layer and the acrylic adhesive layer, so that the acrylic adhesive layer of the tape is more firmly combined with the PET substrate structure, and the air gaps in the PET woven substrate are isolated, thereby further enhancing the dielectric strength and stability; and the breakdown of the tape is delayed by increasing the length of the discharge path, thereby maintaining its excellent voltage resistance performance.

[0096] The high wear-resistant and low-VOC PET-based tapes of Examples 1-3 are all sprayed with a polyurethane film to isolate the PET substrate from the acrylic glue, which can effectively solve the problem of low voltage resistance caused by the presence of air gaps in PET woven fabric substrates, significantly improve the voltage resistance performance of the tape, make it less likely to be broken down, and play an excellent role in protecting automotive wires.

[0097] Test Example 2

[0098] Wear resistance test

[0099] The high wear-resistant and low-VOC PET substrate tapes prepared by the preparation methods of Examples 1-3 and Comparative Example 1 were used as test samples, and were wound around a conductive metal rod in a 50% overlap winding method. The schematic diagram of the sample state during the wear resistance test is shown in FIG. Figure 6 The test steps are based on the scratch and abrasion test in 5.12 Wear Test in the international standard ISO 6722-1 2011. The schematic diagram of the scratch and abrasion test device is as follows: Figure 7 As shown, the test load is 7N, the scraping displacement is 20mm, the scraping length is 15mm, the scraping needle diameter is 0.45mm, the groove depth is 0.8mm, and the scraping needle frequency is 55 times / minute (one back and forth movement is one time). The wear resistance test results are summarized in Table 2.

[0100] Table 2 Wear resistance test results

[0101] Example Wear times Example 1 30760 Comparative Example 1 25720 Example 2 31470 Example 3 33780

[0102] Microcrystalline cellulose, with its high crystallinity and fiber structure, can provide good mechanical strength and wear resistance, and can be used as a reinforcing agent to help improve the wear resistance and durability of the tape. Polyurethane plastic particles have excellent elasticity, flexibility, wear resistance and adhesion. In the wear resistance test, Comparative Example 1 did not introduce a polyurethane film as an intermediate layer PET substrate in direct contact with the acrylic glue, resulting in an overall wear resistance number that was significantly lower than any of Examples 1-3. The introduction of the polyurethane film in Examples 1-3 enhances wear resistance and provides protection, improves the wear resistance of the tape through the elasticity and wear resistance of polyurethane, and absorbs and disperses the force during scraping. The addition of microcrystalline cellulose in Example 2 mainly plays a role in the tape in improving the internal structural strength and overall wear resistance of the substrate, thereby improving the wear resistance and durability of the tape. In Example 3, by using bis(γ-triethoxysilylpropyl)tetrasulfide to modify microcrystalline cellulose, not only the reinforcing effect of microcrystalline cellulose is maintained, but also the problem of uneven dispersion caused by the easy agglomeration of hydroxyl groups on the surface of microcrystalline cellulose is solved. Microcrystalline cellulose and polyurethane plastic particles are grafted by condensation of bis(γ-triethoxysilylpropyl)tetrasulfide with microcrystalline cellulose and vulcanization of polyurethane at the same time, and the adhesion of the polyurethane layer to the PET substrate is further improved compared with Examples 1-2, and the bonding strength between the polyurethane layer and the acrylic adhesive layer is enhanced, so that the acrylic adhesive layer of the tape is more firmly combined with the PET substrate structure. Thereby, the wear resistance of the tape is better exerted, and a more wear-resistant technical effect is provided in practical applications.

[0103] Test Example 3

[0104] VOC content test

[0105] VOC refers to volatile organic compounds, including benzene, toluene, ethylbenzene, xylene, styrene, formaldehyde, acetaldehyde, acrolein, acetone, etc. The concentration unit is milligrams per cubic meter (mg / m 3 ). Test Example 3 The high wear-resistant and low VOC PET substrate tapes prepared by the preparation methods of Examples 1-3 and Comparative Example 1 were used as test samples to test the benzene and formaldehyde contents in VOC. The test steps were based on the national standard "Guidelines for Passenger Car Interior Air Quality Evaluation". The interior benzene content was ≤0.11 mg / m 3 , Formaldehyde content ≤ 0.10mg / m 3 The VOC content is summarized in Table 3.

[0106] Table 3 VOC content test results

[0107] Example <![CDATA[Benzene content (mg / m 3 )]]> <![CDATA[Formaldehyde content (mg / m 3 )]]> Example 1 0 0 Comparative Example 1 1.0 0.8 Example 2 0 0 Example 3 0 0

[0108] In Test Example 3, the benzene and formaldehyde contents in the VOC content test of the PET substrate tapes of Examples 1-3 were both 0 mg / m 3 The reason is that the finished tape with sprayed polyurethane film has a closed isolation effect of the polyurethane film that prevents the glue layer from directly contacting the air, which can effectively prevent the harmful substances in the acrylic glue from volatilizing, and effectively improve the VOC performance of the wiring harness and the whole vehicle. In Examples 2 and 3, microcrystalline cellulose and bis(γ-triethoxysilylpropyl)tetrasulfide-modified microcrystalline cellulose were added to the closed isolation layer of the polyurethane film, respectively, which did not affect the barrier property of the polyurethane film to VOCs. In contrast, the PET substrate tape of Comparative Example 1 is not sprayed with a polyurethane film, and the PET textile substrate itself has good air permeability. The benzene and formaldehyde in the VOCs in the glue will penetrate the PET textile substrate and volatilize into the environment, and the VOC content cannot be effectively controlled and reduced.

[0109] Test Example 4

[0110] Comparative testing with existing solutions

[0111] The high wear-resistant and low-VOC PET base tape of Example 1 of the present invention and the tape of the existing method were tested for voltage resistance, wear resistance, and VOC performance improvement functions (finished wire harness and complete vehicle), and the diameter of the wire harness after wrapping, the softness of the wire harness after wrapping, and the operating efficiency were observed, wherein the existing scheme 1 is a PET textile tape, the existing scheme 2 is a thin PVC tape, the existing scheme 3 is a thick PVC tape, and the existing scheme 4 is an open corrugated tube + PVC tape. The summary is shown in Table 4.

[0112] Table 4 Comparison test with existing solutions

[0113]

[0114]

[0115] As can be seen from Table 4, the existing schemes 1-4 do not have the function of improving VOC performance due to the absence of a polypropylene film barrier layer; for the requirements of pressure resistance and wear resistance, only the tapes of the existing scheme 4 and Example 1 can reach a withstand voltage of 3kV and a wear resistance of more than 30,000 times, and have good pressure resistance and wear resistance. However, the existing scheme 4 is an open corrugated tube + PVC tape, which results in a large diameter of the wire bundle after wrapping, poor flexibility of the wire bundle after wrapping, and low operating efficiency, and it is necessary to install the corrugated tube first and then wrap the PVC tape to complete two operations. The high wear-resistant and low-VOC PET substrate tape of the present invention not only has good pressure resistance and wear resistance, but also has a small diameter of the wire bundle after wrapping, high flexibility of the wire bundle after wrapping, high operating efficiency, and can be completed with only one wrapping. Since the polyurethane film is sprayed to isolate the PET substrate from the acrylic glue, it can effectively block the pollution caused by VOC penetration, and improve VOC performance.

[0116] Embodiment 4:

[0117] The difference from Example 3 is that 5g of bis(γ-triethoxysilylpropyl)tetrasulfide is replaced by 5g of 3-thiocyanatopropyltriethoxysilane, and the other parts are the same. The wear resistance times are 32990 times.

[0118] Embodiment 5:

[0119] The difference from Example 3 is that 5g of bis(γ-triethoxysilylpropyl)tetrasulfide is replaced by 2g of 3-thiocyanatopropyltriethoxysilane and 3g of bis(γ-triethoxysilylpropyl)tetrasulfide, and the others are the same. The wear resistance times are 34820 times.

[0120] The mercapto (-SH) and silane groups of 3-thiocyanatopropyltriethoxysilane can form stable chemical bonds with the substrate surface and react with other molecules to enhance wear resistance. The polysulfide bonds (-SS-) in bis(γ-triethoxysilylpropyl)tetrasulfide improve elasticity and fatigue resistance. The combination of the two forms a complex and stable cross-linked network, which significantly improves the wear resistance of the material.

[0121] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for preparing a highly wear-resistant and low-VOC PET substrate tape, characterized in that: The following steps are involved: (1) Gluing: applying acrylic glue on the polyurethane film of the polyurethane-PET substrate and drying the glue to obtain an acrylic glue layer; (2) Rewinding: attaching the release film Film to the acrylic adhesive layer in step (1), then rolling it up to obtain a large mother roll, and leaving it for 24-48 hours; (3) Rewinding: Unrolling the large mother roll, tearing off the release film, and rewinding into a small mother roll; (4) Slitting: Slitting the small mother roll to obtain the high-wear-resistant and low-VOC PET substrate tape; The polyurethane-PET substrate in step (1) is prepared by the following method: M1. Melting polyurethane plastic particles; M2, sprayed on PET substrate, the spraying thickness is 0.005-0.015mm; M3, drying at 50-70° C. for 2-4 hours to obtain the polyurethane-PET substrate with a lower layer being a PET substrate and an upper layer being a polyurethane film; The polyurethane plastic particles in step M1 are modified polyurethane plastic particles; The preparation method of the modified polyurethane plastic particles is as follows: Dispersing microcrystalline cellulose in anhydrous ethanol, adding bis(γ-triethoxysilylpropyl)tetrasulfide and acetic acid, stirring at room temperature for 2-6 hours, filtering, washing the filter cake with anhydrous ethanol for 2-3 times, air-drying at 50-70° C. for 2-6 hours to obtain modified microcrystalline cellulose, mixing the modified microcrystalline cellulose with polyurethane plastic particles, and melt granulating at 100-200° C. to obtain the modified polyurethane plastic particles; The weight ratio of microcrystalline cellulose, anhydrous ethanol, bis(γ-triethoxysilylpropyl)tetrasulfide and acetic acid is 8-12:200-300:4-6:0.5-1.5; The weight ratio of the modified microcrystalline cellulose and the polyurethane plastic particles is 8-12:1000-1800.

2. The method for preparing the high wear-resistant and low VOC PET substrate tape according to claim 1, characterized in that: The amount of acrylic glue used in step (1) is 8-12 g / m 2 .

3. The method for preparing the high wear-resistant and low VOC PET substrate tape according to claim 1, characterized in that: The drying step in step (1) is 6-stage drying, with a total drying time of 4-8 hours, and the specific temperature of each stage is as follows: Level 1: 35-45℃; Level 2: 65-70℃; Level 3: 90-95°C; Level 4: 90-95°C; Level 5: 65-70℃; Level 6: 35-45℃.

4. A highly wear-resistant and low-VOC PET-based adhesive tape, characterized in that: The method is prepared by any one of claims 1 to 3.

5. An application of the high wear-resistant and low VOC PET-based adhesive tape as claimed in claim 4, characterized in that: It can be used in the protection of automotive wires.

6. The use of the high wear-resistant and low VOC PET-based tape as claimed in claim 5, characterized in that: The applications include automotive low-voltage wire protection and automotive high-voltage wire protection.

Images