UV-curable adhesive tape for automobile wiring harness and preparation method thereof

Abstract

The present application relates to the technical field of adhesive tape, in particular to a UV curing adhesive tape for automobile wiring harness and a preparation method thereof.The UV curing adhesive tape for automobile wiring harness is obtained by coating UV curing adhesive on the adhesive coating surface of the cloth base, and then winding after UV curing.The UV curing adhesive comprises the following components by weight: 80-100 parts of acrylate copolymer, 10-30 parts of active dilution monomer, 10-30 parts of tackifying resin, 0.5-1.0 parts of antioxidant, 2-5 parts of photoinitiator, and 0.5-2 parts of adhesion promoter.The UV curing adhesive tape for automobile wiring harness prepared by the present application not only has excellent mechanical properties, but also has excellent high temperature resistance.

Description

Technical Field

[0001] This invention relates to the field of adhesive tape technology, specifically to a UV-curable adhesive tape for automotive wiring harnesses and its preparation method. Background Technology

[0002] Automotive wiring harnesses are core components for the transmission of electrical and signal signals in a vehicle. Inside the vehicle, wiring harnesses are constantly exposed to complex conditions including high temperatures, oil contamination, continuous vibration, and alternating hot and cold temperatures. Traditional wiring harness protection often relies on ordinary pressure-sensitive adhesive tapes or thermosetting tapes. These traditional solutions have significant drawbacks: ordinary pressure-sensitive tapes rely solely on physical adhesion, making them prone to peeling and delamination under high temperatures and oily conditions; while thermosetting tapes require prolonged high-temperature baking, resulting in high energy consumption, slow production cycles, and increased risk of thermal shrinkage and deformation of the wiring harness substrate, leading to a decrease in yield.

[0003] With the increasing popularity of new energy vehicles, the requirements for insulation, flame retardancy, and aging resistance of high-voltage wiring harnesses are becoming increasingly stringent. UV curing technology, as a novel green manufacturing process, relies on the irradiation of specific wavelengths of ultraviolet light to trigger a chemical reaction in the photoinitiator within the adhesive layer, enabling rapid cross-linking and molding at room temperature. Compared to traditional methods, UV curing significantly shortens the time and eliminates solvent evaporation throughout the process, greatly reducing VOC emissions and perfectly aligning with the green supply chain requirements of modern automakers.

[0004] However, traditional thermoplastic inert tackifying resins (such as rosin resin, terpene resin, petroleum resin, etc.) are mostly thermoplastic inert components that cannot participate in UV crosslinking and are only physically miscible in the adhesive, resulting in multiple defects: First, they have poor compatibility with the acrylate matrix, and are prone to phase separation after long-term use, leading to a deterioration in the mechanical properties of the adhesive layer; second, small molecules are prone to migration and precipitation at high temperatures, reducing the adhesive tape's tackiness and causing brittleness in the wire harness insulation layer; third, without chemical bond binding, the tackifying effect decreases significantly with temperature and time; at the same time, existing tapes have poor resistance to damp heat aging and are prone to embrittlement and delamination in high-temperature environments.

[0005] Therefore, we propose a UV-curable tape for automotive wiring harnesses and its preparation method. Summary of the Invention

[0006] The purpose of this invention is to provide a UV-curable tape for automotive wiring harnesses and its preparation method, so as to solve the problems raised in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a UV-curable tape for automotive wiring harnesses includes the following steps: Step S1: Under light-proof and nitrogen-protected conditions, mix the soft acrylate monomer, hard acrylate monomer, functional monomer, photocrosslinkable monomer and ethyl acetate evenly, add 1 / 3 part by weight of thermal initiator, react at 60-70℃ for 30-40 min, raise the temperature to 75-85℃, add 1 / 3 part by weight of thermal initiator, react for 30-40 min, then add the remaining part by weight of thermal initiator, and continue to react for 2-4 h to obtain the acrylate prepolymer; Step S2: Heat the acrylate prepolymer obtained in step S1 to melt, add the reactive diluent monomer, tackifying resin and antioxidant in sequence under light-protected conditions, stir evenly, cool down to 50-60℃, add photoinitiator and adhesion promoter, continue stirring for 20-30min, and after vacuum degassing, obtain UV-curable adhesive. Step S3: Apply UV-curable adhesive to the fabric substrate, cure with UV, and then roll it up to obtain UV-curable tape for automotive wiring harnesses.

[0008] Further, the UV-curable adhesive comprises the following components by weight: 80-100 parts of acrylate copolymer, 10-30 parts of reactive diluent monomer, 10-30 parts of tackifying resin, 0.5-1.0 parts of antioxidant, 2-5 parts of photoinitiator, and 0.5-2 parts of adhesion promoter.

[0009] Further, the acrylate prepolymer comprises the following components by weight: 60-80 parts of soft acrylate monomer, 10-20 parts of hard acrylate monomer, 3-8 parts of functional monomer, 0.1-0.8 parts of photocrosslinkable monomer, 0.3-1.2 parts of thermal initiator, and 80-100 parts of ethyl acetate. Furthermore, the acrylate soft monomer is one or a mixture of butyl acrylate, isooctyl acrylate, and lauryl acrylate.

[0010] Furthermore, the acrylate hard monomer is one or a mixture of methyl methacrylate, isobornyl acrylate, and styrene.

[0011] Furthermore, the functional monomer is one or more of acrylic acid, hydroxyethyl methacrylate, and glycidyl methacrylate.

[0012] Furthermore, the thermal initiator is azobisisobutyronitrile.

[0013] Furthermore, the photocrosslinkable monomer is 4-acryloyloxybenzophenone.

[0014] Furthermore, the reactive diluent monomer is composed of a long-chain alkyl acrylate and a multifunctional crosslinking monomer in a mass ratio of (3-5):1; the long-chain alkyl acrylate is dodecyl acrylate or octadecyl acrylate; the multifunctional crosslinking monomer is 1,6-hexanediol diacrylate (HDDA) or trimethylolpropane triacrylate (TMPTA).

[0015] Furthermore, the preparation method of the tackifying resin is as follows: Step A: Mix rosin acrylic acid, p-toluenesulfonic acid, hydroquinone and toluene evenly, heat to 110-120℃, the reaction solution begins to reflux, add 2-hydroxyethyl acrylate, reflux reaction for 3-5 hours, cool to room temperature to separate the layers, separate the upper solvent oil, wash and dry to obtain rosin mono-2-(acryloyloxy)ethyl acrylate. Step B: Under nitrogen protection, rosin mono-2-(acryloyloxy)ethyl acrylate, epichlorohydrin and benzyltriethylammonium chloride are mixed evenly and reacted at 100-110℃ for 2-3 hours. The temperature is then lowered to 50-55℃, sodium hydroxide and calcium hydroxide are added, and the reaction continues for 2-3 hours. After filtration, the solvent is removed under vacuum to obtain the epoxidized intermediate. Step C: Under nitrogen protection, the epoxidation intermediate and aminopropyltriethoxysilane are mixed evenly and stirred at 70-80℃ for 1-2 hours. Hydroxyl-terminated polydimethylsiloxane, tetraethyl orthosilicate and dibutyltin dilaurate are added and mixed evenly. After a room temperature alcohol condensation reaction for 12-24 hours, the tackifying resin is obtained.

[0016] Further, in step A, the mass ratio of rosin acrylate, p-toluenesulfonic acid, hydroquinone, toluene, and 2-hydroxyethyl acrylate is 1:(0.08-0.10):(0.01-0.03):(2-4):(0.62-0.65).

[0017] Further, in step B, the mass ratio of rosin mono-2-(acryloyloxy)ethyl acrylate, epichlorohydrin, benzyltriethylammonium chloride, sodium hydroxide, and calcium hydroxide is 1:(4-6):(0.02-0.04):(0.25-0.30):(0.4-0.5).

[0018] Further, in step C, the mass ratio of the epoxidation intermediate, aminopropyltriethoxysilane, hydroxyl-terminated polydimethylsiloxane, tetraethyl orthosilicate, and dibutyltin dilaurate is 1:(1-2):(5-6):(0.1-0.3):(0.02-0.04).

[0019] Furthermore, the adhesion promoter is γ-methacryloyloxypropyltrimethoxysilane.

[0020] Furthermore, the antioxidant is antioxidant 1010.

[0021] Compared with the prior art, the beneficial effects of the present invention are: This invention discloses a UV-curable tape for automotive wiring harnesses and its preparation method. The method involves a partial esterification reaction between rosin acrylic acid and 2-hydroxyethyl acrylate to obtain rosin mono-2-(acryloyloxy)ethyl acrylate (ARAE), which contains both double bonds and carboxyl groups. Next, the rosin mono-2-(acryloyloxy)ethyl acrylate is epoxidized using epichlorohydrin to obtain an epoxidized intermediate. Subsequently, the epoxy group of the epoxidized intermediate undergoes an epoxy-amino addition reaction with the primary amino group of aminopropyltriethoxysilane, introducing a triethoxysilyl group into the rosin backbone. Finally, under the catalysis of dibutyltin dilaurate, it undergoes a deethanolination condensation reaction with hydroxyl-terminated polydimethylsiloxane and tetraethyl orthosilicate to obtain an organosilicon-modified rosin tackifier.

[0022] In this solution, hydroxyl-terminated polydimethylsiloxane (PDMS) is used to chemically modify rosin esters. Organosilicon segments are covalently introduced into the rosin backbone, imparting excellent heat resistance and low surface energy to the tackifying resin. This allows the adhesive layer to maintain high cohesive strength even at high temperatures, effectively overcoming the problems of traditional rosin-based tackifying resins softening and creeping at high temperatures, leading to adhesive layer slippage and detachment at wire harness wrapping points. This significantly improves the high-temperature resistance and adhesion stability of UV-cured tapes. Simultaneously, the molecular backbone retains the photoactive double bonds of acrylate, which can participate in UV crosslinking and curing, increasing the crosslinking density and solvent resistance of the cured adhesive layer. The grafted siloxane groups improve the interfacial adhesion between the tape and the automotive wire harness substrate, thereby extending the material's service life. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Unless otherwise specified, all quantities below are by weight. It should be noted that there are no special restrictions on the manufacturers of the raw materials involved in this invention. Exemplary examples include (in this embodiment) acrylic rosin: brand AR-100; all other raw materials are commercially available.

[0025] Example 1: A method for preparing a UV-curable tape for automotive wiring harnesses, comprising the following processes: Step S1: Under light-protected and nitrogen-protected conditions, 60 parts of butyl acrylate, 10 parts of methyl methacrylate, 3 parts of acrylic acid, 0.1 parts of 4-acryloyloxybenzophenone, and 80 parts of ethyl acetate were mixed evenly. 0.1 parts of azobisisobutyronitrile were added, and the mixture was reacted at 60°C for 30 min. The temperature was then raised to 75°C, and 0.1 parts of azobisisobutyronitrile were added. The mixture was reacted for 30 min, and then another 0.1 parts of azobisisobutyronitrile were added. The reaction was continued for 2 h to obtain the acrylate prepolymer. Step S2: Heat 80 parts of the acrylate prepolymer obtained in step S1 to melt. Under light-protected conditions, add 10 parts of reactive diluent monomer, 10 parts of tackifying resin, and 0.5 parts of antioxidant 1010 in sequence. After stirring evenly, cool to 50°C, then add 2 parts of photoinitiator 1173 and 0.5 parts of γ-methacryloyloxypropyltrimethoxysilane. Continue stirring for 20 minutes. After vacuum degassing, obtain the UV-curable adhesive. The reactive diluent monomer is composed of dodecyl acrylate and 1,6-hexanediol diacrylate in a mass ratio of 3:1. Step S3: Apply UV-curable adhesive to the polyester fiber fabric substrate with an adhesive application rate of 50 g / m². 2 It was then placed under a low-pressure UV mercury lamp with a wavelength of 256 nm for 3 hours, with an energy of 65 mJ / cm². 2 The tape is wound up to obtain a UV-curable tape for automotive wiring harnesses. The preparation method of the tackifying resin is as follows: Step A: Mix 10 parts of rosin acrylic acid, 0.8 parts of p-toluenesulfonic acid, 0.1 parts of hydroquinone and 20 parts of toluene evenly, heat to 110°C, and the reaction solution begins to reflux. Add 6.2 parts of 2-hydroxyethyl acrylate, reflux for 3 hours, cool to room temperature to separate the layers, separate the upper solvent oil, and after washing and drying, obtain rosin mono-2-(acryloyloxy)ethyl acrylate. Step B: Under nitrogen protection, 10 parts of rosin mono-2-(acryloyloxy)ethyl acrylate, 40 parts of epichlorohydrin and 0.2 parts of benzyltriethylammonium chloride were mixed evenly and reacted at 100°C for 2 hours. The temperature was then lowered to 50°C, 2.5 parts of sodium hydroxide and 4 parts of calcium hydroxide were added, and the reaction was continued for 2 hours. After filtration, the solvent was removed under vacuum to obtain the epoxidized intermediate. Step C: Under nitrogen protection, 10 parts of epoxidized intermediate and 10 parts of aminopropyltriethoxysilane are mixed evenly and stirred at 70°C for 1 hour. Then, 50 parts of hydroxyl-terminated polydimethylsiloxane, 1 part of tetraethyl orthosilicate and 0.2 parts of dibutyltin dilaurate are added and mixed evenly. After room temperature alcohol condensation reaction for 12 hours, the tackifying resin is obtained.

[0026] Example 2: A method for preparing a UV-curable tape for automotive wiring harnesses, comprising the following processes: Step S1: Under light-protected and nitrogen-protected conditions, 70 parts of butyl acrylate, 15 parts of methyl methacrylate, 5 parts of acrylic acid, 0.4 parts of 4-acryloyloxybenzophenone, and 90 parts of ethyl acetate were mixed evenly. 0.3 parts of azobisisobutyronitrile were added, and the mixture was reacted at 65°C for 35 min. The temperature was then raised to 80°C, and 0.3 parts of azobisisobutyronitrile were added. The mixture was reacted for 35 min, and then another 0.3 parts of azobisisobutyronitrile were added. The reaction was continued for 3 h to obtain the acrylate prepolymer. Step S2: Heat 90 parts of the acrylate prepolymer obtained in step S1 to melt. Under light-protected conditions, add 20 parts of reactive diluent monomer, 20 parts of tackifying resin, and 0.8 parts of antioxidant 1010 in sequence. After stirring evenly, cool to 55°C, then add 3 parts of photoinitiator 1173 and 1 part of γ-methacryloyloxypropyltrimethoxysilane. Continue stirring for 25 minutes. After vacuum degassing, obtain the UV-curable adhesive. The reactive diluent monomer is composed of octadecyl acrylate and trimethylolpropane triacrylate in a mass ratio of 4:1. Step S3: Apply UV-curable adhesive to the polyester fiber fabric substrate with an adhesive application rate of 50 g / m². 2 It was then placed under a low-pressure UV mercury lamp with a wavelength of 256 nm for 3 hours, with an energy of 65 mJ / cm². 2 The tape is wound up to obtain a UV-curable tape for automotive wiring harnesses. The preparation method of the tackifying resin is as follows: Step A: Mix 20 parts of rosin acrylic acid, 1.8 parts of p-toluenesulfonic acid, 0.4 parts of hydroquinone and 60 parts of toluene evenly, heat to 115°C, and the reaction solution begins to reflux. Add 12.8 parts of 2-hydroxyethyl acrylate, reflux for 4 hours, cool to room temperature and separate into layers. Separate the upper solvent oil, wash and dry to obtain rosin mono-2-(acryloyloxy)ethyl acrylate. Step B: Under nitrogen protection, 20 parts of rosin mono-2-(acryloyloxy)ethyl acrylate, 100 parts of epichlorohydrin and 0.6 parts of benzyltriethylammonium chloride were mixed evenly and reacted at 105°C for 2.5 h. The temperature was then lowered to 52°C, 5.6 parts of sodium hydroxide and 9 parts of calcium hydroxide were added, and the reaction was continued for 2.5 h. After filtration, the solvent was removed under vacuum to obtain the epoxidized intermediate. Step C: Under nitrogen protection, 20 parts of epoxidized intermediate and 30 parts of aminopropyltriethoxysilane were mixed evenly and stirred at 75°C for 1.5 h. Then, 110 parts of hydroxyl-terminated polydimethylsiloxane, 4 parts of tetraethyl orthosilicate and 0.6 parts of dibutyltin dilaurate were added and mixed evenly. After a room temperature dealcoholization condensation reaction for 22 h, the tackifying resin was obtained.

[0027] Example 3: A method for preparing a UV-curable tape for automotive wiring harnesses, comprising the following processes: Step S1: Under light-protected and nitrogen-protected conditions, 80 parts of butyl acrylate, 20 parts of methyl methacrylate, 8 parts of acrylic acid, 0.8 parts of 4-acryloyloxybenzophenone, and 100 parts of ethyl acetate were mixed evenly. 0.4 parts of azobisisobutyronitrile were added, and the mixture was reacted at 70°C for 40 min. The temperature was then raised to 80°C, and 0.4 parts of azobisisobutyronitrile were added again. The mixture was reacted for 40 min, and then another 0.4 parts of azobisisobutyronitrile were added. The reaction was continued for 4 h to obtain the acrylate prepolymer. Step S2: Heat 100 parts of the acrylate prepolymer obtained in step S1 to melt. Under light-protected conditions, add 30 parts of reactive diluent monomer, 30 parts of tackifying resin, and 1.0 part of antioxidant 1010 in sequence. After stirring evenly, cool to 60°C, then add 5 parts of photoinitiator 1173 and 3 parts of γ-methacryloyloxypropyltrimethoxysilane. Continue stirring for 30 minutes. After vacuum degassing, obtain the UV-curable adhesive. The reactive diluent monomer is composed of octadecyl acrylate and 1,6-hexanediol diacrylate in a mass ratio of 5:1. Step S3: Apply UV-curable adhesive to the polyester fiber fabric substrate with an adhesive application rate of 50 g / m². 2 It was then placed under a low-pressure UV mercury lamp with a wavelength of 256 nm for 3 hours, with an energy of 65 mJ / cm². 2 The tape is wound up to obtain a UV-curable tape for automotive wiring harnesses. The preparation method of the tackifying resin is as follows: Step A: Mix 30 parts of rosin acrylic acid, 3 parts of p-toluenesulfonic acid, 0.9 parts of hydroquinone and 120 parts of toluene evenly, heat to 120°C, and the reaction solution begins to reflux. Add 19.5 parts of 2-hydroxyethyl acrylate, reflux for 5 hours, cool to room temperature to separate the layers, separate the upper solvent oil, and after washing and drying, obtain rosin mono-2-(acryloyloxy)ethyl acrylate. Step B: Under nitrogen protection, 30 parts of rosin mono-2-(acryloyloxy)ethyl acrylate, 180 parts of epichlorohydrin and 1.2 parts of benzyltriethylammonium chloride were mixed evenly and reacted at 110°C for 3 hours. The temperature was then lowered to 55°C, 9 parts of sodium hydroxide and 15 parts of calcium hydroxide were added, and the reaction was continued for 3 hours. After filtration, the solvent was removed under vacuum to obtain the epoxidized intermediate. Step C: Under nitrogen protection, 30 parts of epoxidation intermediate and 60 parts of aminopropyltriethoxysilane are mixed evenly and stirred at 80°C for 2 hours. Then, 180 parts of hydroxyl-terminated polydimethylsiloxane, 9 parts of tetraethyl orthosilicate and 1.2 parts of dibutyltin dilaurate are added and mixed evenly. After a room temperature dealcoholization condensation reaction for 24 hours, the tackifying resin is obtained.

[0028] Comparative Example 1: A method for preparing a UV-curable tape for automotive wiring harnesses, comprising the following processes: Step S1: Under light-protected and nitrogen-protected conditions, 70 parts of butyl acrylate, 15 parts of methyl methacrylate, 5 parts of acrylic acid, 0.4 parts of 4-acryloyloxybenzophenone, and 90 parts of ethyl acetate were mixed evenly. 0.3 parts of azobisisobutyronitrile were added, and the mixture was reacted at 65°C for 35 min. The temperature was then raised to 80°C, and 0.3 parts of azobisisobutyronitrile were added. The mixture was reacted for 35 min, and then another 0.3 parts of azobisisobutyronitrile were added. The reaction was continued for 3 h to obtain the acrylate prepolymer. Step S2: Heat 90 parts of the acrylate prepolymer obtained in step S1 to melt. Under light-protected conditions, add 20 parts of reactive diluent monomer, 20 parts of acrylic rosin, and 0.8 parts of antioxidant 1010 in sequence. After stirring evenly, cool to 55°C, then add 3 parts of photoinitiator 1173 and 1 part of γ-methacryloyloxypropyltrimethoxysilane. Continue stirring for 25 minutes. After vacuum degassing, obtain the UV-curable adhesive. The reactive diluent monomer is composed of octadecyl acrylate and trimethylolpropane triacrylate in a mass ratio of 4:1. Step S3: Apply UV-curable adhesive to the polyester fiber fabric substrate with an adhesive application rate of 50 g / m². 2 It was then placed under a low-pressure UV mercury lamp with a wavelength of 256 nm for 3 hours, with an energy of 65 mJ / cm². 2 The tape is wound up to obtain a UV-curable tape for automotive wiring harnesses. Compared with Example 2, Comparative Example 1 replaced the tackifying resin with the same mass of acrylic rosin, and the other steps were the same as in Example 2.

[0029] Comparative Example 2: A method for preparing a UV-curable tape for automotive wiring harnesses, comprising the following processes: Step S1: Under light-protected and nitrogen-protected conditions, 70 parts of butyl acrylate, 15 parts of methyl methacrylate, 5 parts of acrylic acid, 0.4 parts of 4-acryloyloxybenzophenone, and 90 parts of ethyl acetate were mixed evenly. 0.3 parts of azobisisobutyronitrile were added, and the mixture was reacted at 65°C for 35 min. The temperature was then raised to 80°C, and 0.3 parts of azobisisobutyronitrile were added. The mixture was reacted for 35 min, and then another 0.3 parts of azobisisobutyronitrile were added. The reaction was continued for 3 h to obtain the acrylate prepolymer. Step S2: Heat 90 parts of the acrylate prepolymer obtained in step S1 to melt. Under light-protected conditions, add 20 parts of reactive diluent monomer and 0.8 parts of antioxidant 1010 sequentially. After stirring evenly, cool to 55°C, then add 3 parts of photoinitiator 1173 and 1 part of γ-methacryloyloxypropyltrimethoxysilane. Continue stirring for 25 minutes. After vacuum degassing, obtain the UV-curable adhesive. The reactive diluent monomer is composed of octadecyl acrylate and trimethylolpropane triacrylate in a mass ratio of 4:1. Step S3: Apply UV-curable adhesive to the polyester fiber fabric substrate with an adhesive application rate of 50 g / m². 2It was then placed under a low-pressure UV mercury lamp with a wavelength of 256 nm for 3 hours, with an energy of 65 mJ / cm². 2 The tape is wound up to obtain a UV-curable tape for automotive wiring harnesses. Compared with Example 2, no tackifying resin was introduced in Comparative Example 2, but the other steps were the same as in Example 2.

[0030] Comparative Example 3: A method for preparing a UV-curable tape for automotive wiring harnesses, comprising the following processes: Step S1: Under light-protected and nitrogen-protected conditions, 70 parts of butyl acrylate, 15 parts of methyl methacrylate, 5 parts of acrylic acid, 0.4 parts of 4-acryloyloxybenzophenone, and 90 parts of ethyl acetate were mixed evenly. 0.3 parts of azobisisobutyronitrile were added, and the mixture was reacted at 65°C for 35 min. The temperature was then raised to 80°C, and 0.3 parts of azobisisobutyronitrile were added. The mixture was reacted for 35 min, and then another 0.3 parts of azobisisobutyronitrile were added. The reaction was continued for 3 h to obtain the acrylate prepolymer. Step S2: Heat 90 parts of the acrylate prepolymer obtained in step S1 to melt. Under light-protected conditions, add 20 parts of reactive diluent monomer, 20 parts of epoxidation intermediate, and 0.8 parts of antioxidant 1010 in sequence. After stirring evenly, cool to 55°C, then add 3 parts of photoinitiator 1173 and 1 part of γ-methacryloyloxypropyltrimethoxysilane. Continue stirring for 25 minutes. After vacuum degassing, obtain the UV-curable adhesive. The reactive diluent monomer is composed of octadecyl acrylate and trimethylolpropane triacrylate in a mass ratio of 4:1. Step S3: Apply UV-curable adhesive to the polyester fiber fabric substrate with an adhesive application rate of 50 g / m². 2 It was then placed under a low-pressure UV mercury lamp with a wavelength of 256 nm for 3 hours, with an energy of 65 mJ / cm². 2 The tape is wound up to obtain a UV-curable tape for automotive wiring harnesses. Compared with Example 2, in Comparative Example 3, the tackifying resin was replaced with the same mass of epoxide intermediate, and the other steps were the same as in Example 2.

[0031] Experiment: Samples were prepared using the UV-curable tapes for automotive wiring harnesses obtained in Examples 1-3 and Comparative Examples 1-3. The performance of each sample was tested, and the results were recorded. The samples were placed in environments of 50℃ and 150℃ and aged for 24 hours under light intensity of 2000 lux, respectively, followed by mechanical property testing. Tensile strength was measured using a tensile testing machine; peel force was tested as follows: the aged tape was adhered to the test surface of a glass plate, and the tape was peeled off at a uniform speed with a peel angle of 180° using a peel force tester, and the force required during the peeling process was recorded.

[0032] The test results are shown in Table 1.

[0033] Table 1 Performance test results of UV-cured tape for automotive wiring harnesses

[0034] Based on the data in the table above, the following conclusions can be clearly drawn: Combining Examples 1-3 and Comparative Examples 1-3, it can be seen that the UV-curable tape for automotive wiring harnesses prepared by the present invention not only has excellent mechanical properties, but also excellent high-temperature resistance.

[0035] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for preparing a UV-curable tape for automotive wiring harnesses, characterized in that: Includes the following steps: Step S1: Under light-proof and nitrogen-protected conditions, mix the soft acrylate monomer, hard acrylate monomer, functional monomer, photocrosslinkable monomer and ethyl acetate evenly, add 1 / 3 part by weight of thermal initiator, react, heat up, add 1 / 3 part by weight of thermal initiator, react, then add the remaining part by weight of thermal initiator, continue the reaction, and obtain the acrylate prepolymer. Step S2: Heat the acrylate prepolymer obtained in step S1 to melt, add the reactive diluent monomer, tackifying resin and antioxidant in sequence under light-protected conditions, stir evenly, cool down, add photoinitiator and adhesion promoter, continue to stir evenly, and after vacuum degassing, obtain UV curable adhesive. Step S3: Apply UV-curable adhesive to the fabric substrate, cure with UV, and then roll it up to obtain UV-curable tape for automotive wiring harnesses.

2. The method for preparing a UV-curable tape for automotive wiring harnesses according to claim 1, characterized in that: The preparation method of the tackifying resin is as follows: Step A: Mix rosin acrylic acid, p-toluenesulfonic acid, hydroquinone and toluene evenly, heat to 110-120℃, the reaction solution begins to reflux, add 2-hydroxyethyl acrylate, reflux reaction for 3-5 hours, cool to room temperature to separate the layers, separate the upper solvent oil, wash and dry to obtain rosin mono-2-(acryloyloxy)ethyl acrylate. Step B: Under nitrogen protection, rosin mono-2-(acryloyloxy)ethyl acrylate, epichlorohydrin and benzyltriethylammonium chloride are mixed evenly and reacted at 100-110℃ for 2-3 hours. The temperature is then lowered to 50-55℃, sodium hydroxide and calcium hydroxide are added, and the reaction continues for 2-3 hours. After filtration, the solvent is removed under vacuum to obtain the epoxidized intermediate. Step C: Under nitrogen protection, the epoxidation intermediate and aminopropyltriethoxysilane are mixed evenly and stirred at 70-80℃ for 1-2 hours. Hydroxyl-terminated polydimethylsiloxane, tetraethyl orthosilicate and dibutyltin dilaurate are added and mixed evenly. After a room temperature alcohol condensation reaction for 12-24 hours, the tackifying resin is obtained.

3. The method for preparing a UV-curable tape for automotive wiring harnesses according to claim 1, characterized in that: The acrylate prepolymer comprises the following components by weight: 60-80 parts of soft acrylate monomer, 10-20 parts of hard acrylate monomer, 3-8 parts of functional monomer, 0.1-0.8 parts of photocrosslinkable monomer, 0.3-1.2 parts of thermal initiator, and 80-100 parts of ethyl acetate.

4. The method for preparing a UV-curable tape for automotive wiring harnesses according to claim 1, characterized in that: The UV-curable adhesive comprises the following components by weight: 80-100 parts of acrylate copolymer, 10-30 parts of reactive diluent monomer, 10-30 parts of tackifying resin, 0.5-1.0 parts of antioxidant, 2-5 parts of photoinitiator, and 0.5-2 parts of adhesion promoter.

5. The method for preparing a UV-curable tape for automotive wiring harnesses according to claim 1, characterized in that: The reactive diluent monomer is composed of a long-chain alkyl acrylate and a multifunctional crosslinking monomer in a mass ratio of (3-5):1; the long-chain alkyl acrylate is dodecyl acrylate or octadecyl acrylate; the multifunctional crosslinking monomer is 1,6-hexanediol diacrylate or trimethylolpropane triacrylate.

6. The method for preparing a UV-curable tape for automotive wiring harnesses according to claim 1, characterized in that: The acrylate soft monomer is one or a mixture of butyl acrylate, isooctyl acrylate, and lauryl acrylate.

7. The method for preparing a UV-curable tape for automotive wiring harnesses according to claim 1, characterized in that: The acrylate hard monomer is one or a mixture of methyl methacrylate, isobornyl acrylate, and styrene.

8. The method for preparing a UV-curable tape for automotive wiring harnesses according to claim 1, characterized in that: The functional monomer is one or more of acrylic acid, hydroxyethyl methacrylate, and glycidyl methacrylate.

9. The method for preparing a UV-curable tape for automotive wiring harnesses according to claim 1, characterized in that: The adhesion promoter is γ-methacryloyloxypropyltrimethoxysilane.

10. A UV-curable tape for automotive wiring harnesses prepared by the preparation method according to any one of claims 1-9.

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