UV tackifying structural adhesive tape as well as preparation method and application thereof

Abstract

The invention discloses a UV tackifying structural adhesive tape as well as a preparation method and application thereof. The adhesive tape comprises a base material layer and a UV tackifying structural adhesive layer arranged on at least one surface of the base material layer, and the adhesive layer is prepared from the following raw materials: 70-80 parts of a polyurethane oligomer which is aromatic polyester polyurethane containing unsaturated end groups, 10-20 parts of an acryloyloxy carboxylic acid derivative, 1-5 parts of a curing agent, 1-5 parts of a curing agent, and 1-5 parts of a curing agent. The invention relates to a photoinitiator, which is prepared from the following components in parts by weight: 1-2 parts of a difunctional acrylic monomer, 0.5-0.8 part of hydroxypropyl acrylate and 0.8-1.2 parts of a photoinitiator, wherein the photoinitiator is prepared by compounding at least two photoinitiators with different absorption wavelengths. The photoinitiator is prepared from the following components in parts by weight: 1-2 parts of a difunctional acrylic monomer, 1-2 parts of a difunctional acrylic monomer, 0.5-0.8 part of hydroxypropyl acrylate and 0.8-1.2 parts of a photoinitiator, and the photoinitiator is prepared by compounding at least two photoinitiators with different absorption wavelengths. The preparation method comprises the following steps: synthesizing a polyurethane oligomer, preparing glue according to mass parts, diluting, coating a base material with the glue, drying, compounding a release film, and storing. The adhesive tape has excellent positioning-locking synergy, and is simple and convenient in preparation process and stable in storage.

Description

Technical Field

[0001] This invention belongs to the field of adhesive products technology, specifically relating to a UV-enhanced structural adhesive tape, its preparation method, and its application. Background Technology

[0002] In high-end manufacturing fields such as electronic equipment, new energy vehicles, and aerospace, it is often necessary to temporarily bond and position metals (such as aluminum plates) or high-performance polymer materials (such as polyimide PI films) before implementing permanent structural fixation. Existing technologies for UV-curable adhesives or films often emphasize post-curing strength, temperature resistance, yellowing resistance, or reworkability. However, the assembly process often requires "bonding and positioning—re-curing and locking," presenting a challenge: if the initial tack before UV irradiation is too high, it is difficult to adjust the position during bonding, and misalignment cannot be corrected; if the initial tack before UV irradiation is too low, the positioning stability is insufficient, and misalignment is likely to occur during handling or subsequent processes. Therefore, there is an urgent need to develop a new type of tape that possesses moderate initial tack before UV irradiation to achieve precise bonding and reworkability, while rapidly forming ultra-high adhesion and structural strength after UV irradiation, making it particularly suitable for reliable assembly of difficult-to-bond substrates such as aluminum plates and polyimide. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a UV-enhanced structural adhesive tape with excellent initial rework positioning effect and later structural strength, as well as its preparation method and application.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A UV-modified structural adhesive tape includes a substrate layer and a UV-modified structural adhesive layer disposed on at least one side of the substrate layer, wherein the UV-modified structural adhesive layer is prepared from the following raw materials in parts by weight: 70 to 80 parts of polyurethane oligomer, wherein the polyurethane oligomer is an aromatic polyester polyurethane containing unsaturated end groups. 10 to 20 parts of acryloyloxycarboxylic acid derivative, Acryloyloxyethyl phosphate and / or acryloyloxyethyl phosphate derivatives, 3 to 5 parts, 1 to 2 parts of bifunctional acrylic monomer, Hydroxypropyl acrylate 0.5 to 0.8 parts, The photoinitiator is 0.8 to 1.2 parts, and the photoinitiator is composed of at least two photoinitiators with different absorption wavelengths to achieve curing of different adhesive layer thicknesses.

[0005] Preferably, in the above-mentioned UV-adhesive structural adhesive tape, the aromatic polyester in the polyurethane oligomer is obtained by alkyd polymerization, wherein the alcohol is at least one of neopentyl glycol, methyl propylene glycol and methyl pentyl glycol, and the acid is terephthalic acid and / or isophthalic acid.

[0006] Preferably, the aromatic polyester in the aforementioned UV-adhesive structural adhesive tape is poly(neopentyl terephthalate) diol obtained by reacting terephthalic acid with neopentyl glycol.

[0007] Preferably, the above-mentioned UV-adhesive structural adhesive tape contains a polyurethane oligomer prepared by reacting polypentyl terephthalate diol, diisocyanate and hydroxyethyl methacrylate in a molar ratio of 4-6:5-7:2.

[0008] Preferably, in the above-mentioned UV-adhesive structural adhesive tape, the reaction includes the following steps: First, dehydrate poly(neopentyl terephthalate) diol under vacuum at 110℃~120℃ for 1.5h~2h, cool down to below 80℃, add diisocyanate, heat up to 80℃~82℃ and react for 3h~3.5h, then cool down to 70℃~72℃, add hydroxyethyl methacrylate, and react for 4.5h~5h to obtain polyurethane oligomer.

[0009] Preferably, in the aforementioned UV-cured structural adhesive tape, the diisocyanate is selected from isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), and 4,4′-dicyclohexylmethane diisocyanate (HDI). 12 One or more of MDI, diphenylmethane diisocyanate-50 (MDI-50).

[0010] Preferably, in the above-mentioned UV-adhesive structural adhesive tape, the photoinitiator is a compound of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (819) and 1-hydroxycyclohexyl-phenyl ketone (184), wherein the mass ratio of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide to 1-hydroxycyclohexyl-phenyl ketone is 2:0.8 to 1.2.

[0011] Preferably, in the aforementioned UV-adhesive structural adhesive tape, the acryloyloxycarboxylic acid derivative is one or more of β-acryloyloxypropionic acid, acryloyloxybutyric acid, methacryloyloxypropionic acid, and methacryloyloxybutyric acid.

[0012] Preferably, in the aforementioned UV-adhesive structural adhesive tape, the acryloyloxyethyl phosphate derivative is one or more of methacryloyloxyethyl phosphate, acryloyloxyethyl dimethyl phosphate, methacryloyloxyethyl dimethyl phosphate, acryloyloxyethyl phenyl phosphate, and methacryloyloxyethyl phenyl phosphate.

[0013] Preferably, in the aforementioned UV-adhesive structural adhesive tape, the difunctional acrylic monomer is one or more of ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, cyclohexanediethanol diacrylate, and cyclohexanediethanol dimethacrylate.

[0014] As a general technical concept, the present invention also provides a method for preparing the above-mentioned UV-adhesive structural adhesive tape, comprising the following steps: (1) Mix the raw materials in the above UV tack-enhancing structural adhesive tape according to the mass parts mentioned above under light-protected conditions, and dilute with organic solvent to a solid content of 30% to 50% to obtain UV tack-enhancing structural adhesive. (2) Dilute the UV-tackified structural adhesive with an organic solvent to the coating viscosity, and coat it onto the corona surface of the substrate layer under light-protected conditions; (3) The adhesive is dried in stages to remove organic solvents. A release film is then laminated onto the dried adhesive layer and stored away from light to obtain UV-enhanced structural adhesive tape.

[0015] In the preferred embodiment of the above-mentioned method for preparing UV-adhesive structural adhesive tape, the segmented drying temperature is 60℃~120℃, and the segmented drying time is 3min~5min; the organic solvent is one or more of toluene, ethyl acetate, and methyl ethyl ketone; the coating viscosity is 300 mPa·s~500 mPa·s; and the dry adhesive thickness of the UV-adhesive structural adhesive layer is 30μm~80μm.

[0016] As a general technical concept, the present invention also provides the application of the above-mentioned UV-adhesive structural adhesive tape or the UV-adhesive structural adhesive tape prepared by the above-mentioned preparation method in the bonding and fixing of metal substrates or polyimide substrates.

[0017] Compared with the prior art, the advantages of the present invention are as follows: (1) In view of the technical problem that existing UV tapes are difficult to balance “positioning” and “structural strength” during the assembly process, the present invention provides a UV-adhesive structural adhesive tape. A flexible host network is constructed using polyurethane oligomers with unsaturated end groups. This network, combined with acryloxycarboxylic acid derivatives and / or acryloxyethyl phosphate derivatives, forms a strong polar interface, giving the tape a moderate peel force of 100–200 g / 25 mm before UV irradiation, facilitating bonding, positioning, and rework. After UV irradiation, rapid cross-linking occurs, and the strong polar interaction between the acryloxycarboxylic acid derivatives and / or acryloxyethyl phosphate derivatives, building upon the host network, results in a surge in peel force and shear strength. This significantly improves adhesion to difficult-to-bond substrates, such as aluminum plates (>5000 g / 25 mm) and PI (>2000 g / 25 mm), with shear strengths both exceeding 10 MPa. This represents a dramatic performance improvement from "positionable" to "structurally locked," exhibiting excellent positioning-locking synergy and meeting the bonding requirements of engineering structures.

[0018] (2) The UV-enhanced structural adhesive tape of the present invention is made of at least two photoinitiators with different absorption wavelengths. The photoinitiator with a longer absorption wavelength can achieve deep curing, while the one with a shorter absorption wavelength promotes surface curing. This synergistically achieves curing of different adhesive layer thicknesses, taking into account both rapid surface curing and deep penetration capabilities, ensuring that the thick adhesive layer is completely cured without any unreacted residue.

[0019] (3) The UV-enhanced structural adhesive tape of the present invention uses hydroxypropyl acrylate, which has a good synergistic regulating effect on the system. The double bond participates in free radical polymerization, and the hydroxyl group provides polarity, forms hydrogen bonds, and participates in chemical reactions. It is a bridge between performance regulation and interfacial interaction, so that hydroxypropyl acrylate can work synergistically with multifunctional monomers to balance curing speed, mechanical properties and shrinkage rate, thereby better ensuring product performance.

[0020] (4) The preparation method of the UV-enhanced structural adhesive tape of the present invention is simple, stable in storage, and the tape shape is convenient for automated application. It has good stability when stored away from light and is suitable for large-scale industrial production. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the UV-enhanced structural adhesive tape of the present invention.

[0022] Figure 2 This is a schematic diagram showing the change trend of peel force of the UV-enhanced structural adhesive tape of the present invention before and after UV irradiation.

[0023] Figure 3 This is a schematic diagram of the preparation process of the UV-enhanced structural adhesive tape of the present invention. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0025] This invention discloses a UV-modified structural adhesive tape, the tape structure of which is as follows: Figure 1 As shown, it includes a substrate layer and a UV-adhesive structural adhesive layer disposed on at least one side of the substrate layer. The UV-adhesive structural adhesive layer is prepared from the following raw materials in parts by weight: 70-80 parts of polyurethane oligomer, which is an aromatic polyester polyurethane containing unsaturated end groups. 10 to 20 parts of acryloyloxycarboxylic acid derivative, Acryloyloxyethyl phosphate and / or acryloyloxyethyl phosphate derivatives, 3 to 5 parts, 1 to 2 parts of bifunctional acrylic monomer, Hydroxypropyl acrylate 0.5 to 0.8 parts, The photoinitiator is 0.8 to 1.2 parts, and the photoinitiator is a compound of at least two photoinitiators with different absorption wavelengths to achieve curing of different adhesive layer thicknesses. The specific mass parts of each component in Examples 1-9 are detailed in Table 1.

[0026] The aromatic polyester in the polyurethane oligomer is obtained by alkyd polymerization, wherein the alcohol is at least one selected from neopentyl glycol, methyl propylene glycol, and methyl pentyl glycol, and the acid is terephthalic acid and / or isophthalic acid. Preferably, terephthalic acid is reacted with neopentyl glycol to obtain poly(neopentyl terephthalate) diol.

[0027] Further preferred, the polyurethane oligomer is prepared by reacting poly(neopentyl terephthalate) diol, diisocyanate and hydroxyethyl methacrylate in a molar ratio of 4-6:5-7:2.

[0028] Further preferably, the photoinitiator is a compound of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (819) and 1-hydroxycyclohexyl-phenyl ketone (184) in a mass ratio of 2:0.8 to 1.2, preferably 2:1. The substrate layer of this invention uses a 100 μm thick PET film, and the dry adhesive thickness of the UV-adhesive structural adhesive layer is 30 μm to 80 μm, preferably 50 ± 2 μm. UV curing requires irradiation from the back of the substrate layer, meaning that the UV needs to reach a thickness of 150 μm to achieve a good curing effect. The preferred 819 has a longer absorption wavelength, enabling deep curing, while the 184 has a shorter absorption wavelength, which is beneficial for promoting surface curing. The compounding of these two effectively ensures complete curing of the thick adhesive layer.

[0029] The acryloyloxycarboxylic acid derivative is one or more of β-acryloyloxypropionic acid, acryloyloxybutyric acid, methacryloyloxypropionic acid, and methacryloyloxybutyric acid, preferably β-acryloyloxypropionic acid.

[0030] Acryloyloxyethyl phosphate and / or acryloyloxyethyl phosphate derivatives, wherein the acryloyloxyethyl phosphate derivative is one or more of methacryloyloxyethyl phosphate, acryloyloxyethyl dimethyl phosphate, methacryloyloxyethyl dimethyl phosphate, acryloyloxyethyl phenyl phosphate, and methacryloyloxyethyl phenyl phosphate. Acryloyloxyethyl phosphate is preferred.

[0031] The bifunctional acrylic monomer is one or more of ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, cyclohexanediethanol diacrylate, and cyclohexanediethanol dimethacrylate, preferably 1,4-butanediol diacrylate.

[0032] The UV-enhanced structural adhesive tape of this invention achieves bonding and positioning, followed by a sudden increase in adhesive strength and structural locking triggered by UV radiation (e.g. Figure 2 As shown in the figure, it is suitable for high-strength bonding and assembly of metal / polymer substrates.

[0033] This invention discloses a method for preparing a UV-adhesive structural adhesive tape, such as... Figure 3 As shown, it includes the following steps: (1) Synthesis of polyurethane oligomer: Poly(neopentyl terephthalate) diol (HF-8211, Zhejiang Huafeng New Materials Co., Ltd.), diisocyanate (WANNATE MDI-50, Wanhua Chemical Group Co., Ltd.) and hydroxyethyl methacrylate (HEMA) were mixed in a molar ratio of 4:5:2. First, HF-8211 was dehydrated under vacuum at 120°C for 2 hours, then cooled to below 80°C, MDI-50 was added, the temperature was slowly raised to 80°C, and the reaction was carried out at this temperature for 3 hours. Then the temperature was lowered to 70°C, HEMA was added, and the reaction was carried out at this temperature for 4 hours to obtain a polyurethane oligomer (PUA1) containing unsaturated end groups of (meth)acrylic acid, with a theoretical molecular weight of 5510.

[0034] Poly(neopentyl terephthalate) diol (HF-8211, Zhejiang Huafeng New Materials Co., Ltd.), diisocyanate (WANNATE MDI-50, Wanhua Chemical Group Co., Ltd.), and hydroxyethyl methacrylate (HEMA) were reacted in a molar ratio of 5:6:2. HF-8211 was first dehydrated under vacuum at 120°C for 2 hours, then cooled to below 80°C, MDI-50 was added, and the temperature was slowly raised to 80°C and reacted at this temperature for 3 hours. Then the temperature was lowered to 70°C, HEMA was added, and the reaction was carried out at this temperature for 4 hours to obtain a polyurethane oligomer (PUA2) containing unsaturated end groups of (meth)acrylic acid, with a theoretical molecular weight of 6760.

[0035] Poly(neopentyl terephthalate) diol (HF-8211, Zhejiang Huafeng New Materials Co., Ltd.), diisocyanate (WANNATE MDI-50, Wanhua Chemical Group Co., Ltd.), and hydroxyethyl methacrylate (HEMA) were reacted in a molar ratio of 6:7:2. HF-8211 was first dehydrated under vacuum at 120°C for 2 hours, then cooled to below 80°C, MDI-50 was added, and the temperature was slowly raised to 80°C and reacted at this temperature for 3 hours. Then the temperature was lowered to 70°C, HEMA was added, and the reaction was carried out at this temperature for 4 hours to obtain a polyurethane oligomer (PUA3) containing unsaturated (meth)acrylic acid end groups, with a theoretical molecular weight of 8010.

[0036] (2) Adhesive preparation: Weigh out the following by weight: 70-80 parts of PUA, 10-20 parts of β-acryloyloxypropionic acid (β-CEA), 3-5 parts of methacryloyloxyethyl phosphate (MAPEG), 1-2 parts of 1,4-butanediol diacrylate (BDDA), 0.5-0.8 parts of hydroxypropyl acrylate (HPA), and 0.8-1.2 parts of photoinitiator. Stir and mix evenly under a yellow light lamp, and dilute with methyl ethyl ketone to a solid content of 40% to obtain UV tackifying structural adhesive.

[0037] The photoinitiator is composed of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (819) and 1-hydroxycyclohexyl-phenyl ketone (184) in a mass ratio of 2:1.

[0038] (3) Preparation of tape: The UV tackifying structural adhesive is diluted with methyl ethyl ketone to the coating viscosity (about 500 mPa·s), coated on the corona-treated surface of a 100 μm thick PET film under yellow light, and dried through 7 drying tunnels, each 4 meters long. The tunnel temperatures are set sequentially to 80℃, 70℃, 100℃, 120℃, 120℃, 120℃, and 60℃. The coating speed is controlled at 7 m / min, and the dry adhesive thickness is controlled at 50 ± 2 μm. The release film is then laminated and the tape is wound and stored in the dark.

[0039] (4) Sample preparation and testing: The UV-enhanced structural adhesive tape is bonded to the surface of the aluminum plate or PI substrate and rolled and bonded under standard conditions; the UV irradiation is performed using a mercury lamp, and the UV energy dose can be selected from 800 to 1200 mJ / cm². (5) The performance of the UV-enhanced structural adhesive tapes prepared in each embodiment is tested. The peel force on the aluminum plate before and after UV irradiation, the peel force on the IP after UV irradiation, and the shear strength on the aluminum plate and IP after UV irradiation are measured respectively. The peel force is in accordance with GB / T 2792-2014, and the shear strength is in accordance with GB / T7124. The specific test data are shown in Table 1.

[0040] Table 1. Component dosage and product performance test data for Examples 1-9

[0041] Table 1 shows that the UV-enhanced structural adhesive tapes prepared in Examples 1-9 have a peel force of 100-200 g / 25 mm on aluminum plates before UV irradiation, which is moderate and facilitates bonding, positioning, and rework. After UV irradiation, the peel force on aluminum plates is >5000 g / 25 mm, and the shear strength is >10 MPa. After UV irradiation, the peel force on PI is >2000 g / 25 mm, and the shear strength is >10 MPa, which significantly improves the adhesion to difficult-to-bond substrates. This fully demonstrates that the UV-enhanced structural adhesive tapes prepared by the preparation method of the present invention through the compounding of specific raw materials and mass parts have excellent positioning-locking synergy and can meet the bonding requirements of engineering structures. Among them, the polyurethane oligomer synthesized by polypentyl terephthalate diol, diisocyanate and hydroxyethyl methacrylate in a molar ratio of 4-6:5-7:2 has a molecular weight between 5000 and 8500 and has good performance. The other components can meet the requirements of the present invention at both the upper and lower limits. More preferably, when the molar ratio of the three is 5:6:2, the comprehensive performance reaches the optimal level.

[0042] Comparative Example 1 A method for preparing a UV-modified structural adhesive tape is basically the same as that in Example 4, except that the molar ratio of each component used in step (1) is different. Specifically, the molar ratio of HF-8211, MDI-50 and HEMA is 3:4:2, resulting in a polyurethane oligomer (PUA4) containing unsaturated (meth)acrylic acid end groups with a theoretical molecular weight of 4260. In step (2), 75 parts of polyurethane oligomer are used. Other steps, reagents and parameters are the same as in Example 4, as detailed in Table 2.

[0043] Comparative Example 2 A method for preparing a UV-adhesive structural adhesive tape is basically the same as that in Example 5. The main difference is that in step (1), the molar ratio of each component used in the preparation of the polyurethane oligomer is different. Specifically, the molar ratio of HF-8211, MDI-50 and HEMA is 3:4:2, and a polyurethane oligomer (PUA4) containing unsaturated end groups of (meth)acrylic acid is obtained, with a theoretical molecular weight of 4260. Other steps, reagents and parameters are the same as in Example 5, as detailed in Table 2.

[0044] Comparative Example 3 A method for preparing a UV-adhesive structural adhesive tape is basically the same as that in Example 6. The main difference is that in step (1), the molar ratio of each component used in the preparation of the polyurethane oligomer is different. Specifically, the molar ratio of HF-8211, MDI-50 and HEMA is 3:4:2, and a polyurethane oligomer (PUA4) containing unsaturated end groups of (meth)acrylic acid is obtained with a theoretical molecular weight of 4260. In step (2), 75 parts of polyurethane oligomer are used. Other steps, reagents and parameters are the same as in Example 6. See Table 2 for details.

[0045] Comparative Example 4 A method for preparing a UV-adhesive structural adhesive tape is basically the same as that in Example 4, except that the molar ratio of each component used in step (1) is different. Specifically, the molar ratio of HF-8211, MDI-50 and HEMA is 7:8:2, resulting in a polyurethane oligomer (PUA5) containing unsaturated (meth)acrylic acid end groups with a theoretical molecular weight of 9060. In step (2), 75 parts of polyurethane oligomer are used, and the other steps, reagents and parameters are the same as in Example 4, as detailed in Table 2.

[0046] Comparative Example 5 A method for preparing a UV-modified structural adhesive tape is basically the same as that in Example 5, except that the molar ratio of each component used in step (1) for preparing the polyurethane oligomer is different. Specifically, the molar ratio of HF-8211, MDI-50 and HEMA is 7:8:2, resulting in a polyurethane oligomer (PUA5) containing unsaturated (meth)acrylic acid end groups with a theoretical molecular weight of 9060. Other steps, reagents and parameters are the same as in Example 5, as detailed in Table 2.

[0047] Comparative Example 6 A method for preparing a UV-adhesive structural adhesive tape is basically the same as that in Example 6, except that the molar ratio of each component used in step (1) is different. Specifically, the molar ratio of HF-8211, MDI-50 and HEMA is 7:8:2, resulting in a polyurethane oligomer (PUA5) containing unsaturated (meth)acrylic acid end groups with a theoretical molecular weight of 9060. In step (2), 75 parts of polyurethane oligomer are used, and the other steps, reagents and parameters are the same as in Example 6, as detailed in Table 2.

[0048] Comparative Example 7 A method for preparing a UV-adhesive structural adhesive tape is basically the same as that in Example 5. The main difference is that in step (2), methacryloyloxyethyl phosphate (MAPEG) is not added. Other steps, reagents and parameters are the same as in Example 5, as detailed in Table 2.

[0049] Comparative Example 8 A method for preparing a UV-adhesive structural adhesive tape is basically the same as that in Example 5. The main difference is that β-acryloyloxypropionic acid (β-CEA) is not added in step (2). Other steps, reagents and parameters are the same as in Example 5, as detailed in Table 2.

[0050] The tapes of Comparative Examples 1-8 were tested according to the detection method of the embodiment, and the specific test data are shown in Table 2.

[0051] Table 2. Component dosage and product performance test data for Comparative Examples 1-8

[0052] Table 2 shows that the molecular weight of the polyurethane oligomer needs to be controlled within a suitable range. When the molecular weight of the polyurethane oligomer is too low (below 5000) or too high (above 8500), as shown in Comparative Examples 1-6, regardless of how other components are adjusted, even when adjustments are made around the optimal performance of Example 5, the performance requirements cannot be fully met. Furthermore, Comparative Example 7, due to the absence of the essential components acryloyloxyethyl phosphate and / or acryloyloxyethyl phosphate derivatives, and Comparative Example 8, due to the absence of the essential component acryloyloxycarboxylic acid derivative, exhibits significantly reduced performance across all aspects.

[0053] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the spirit and technical essence of the invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the scope of protection of the present invention.

Claims

1. A UV-adhesive structural adhesive tape, comprising a substrate layer and a UV-adhesive structural adhesive layer disposed on at least one side of the substrate layer, characterized in that, The UV-adhesive structural adhesive layer is prepared from the following raw materials in parts by weight: 70 to 80 parts of polyurethane oligomer, wherein the polyurethane oligomer is an aromatic polyester polyurethane containing unsaturated end groups. 10 to 20 parts of acryloyloxycarboxylic acid derivative, Acryloyloxyethyl phosphate and / or acryloyloxyethyl phosphate derivatives, 3 to 5 parts, 1 to 2 parts of bifunctional acrylic monomer, Hydroxypropyl acrylate 0.5 to 0.8 parts, The photoinitiator is 0.8 to 1.2 parts, and the photoinitiator is composed of at least two photoinitiators with different absorption wavelengths to achieve curing of different adhesive layer thicknesses.

2. The UV-cured structural adhesive tape according to claim 1, characterized in that, The molecular weight of the polyurethane oligomer is 5000-8500; the aromatic polyester in the polyurethane oligomer is obtained by alkyd polymerization, wherein the alcohol is at least one of neopentyl glycol, methyl propylene glycol and methyl pentyl glycol, and the acid is terephthalic acid and / or isophthalic acid.

3. The UV-modified structural adhesive tape according to claim 2, characterized in that, The aromatic polyester is poly(neopentyl terephthalate) diol obtained by reacting terephthalic acid with neopentyl glycol.

4. The UV-modified structural adhesive tape according to claim 3, characterized in that, The polyurethane oligomer is prepared by reacting poly(neopentyl terephthalate) diol, diisocyanate and hydroxyethyl methacrylate in a molar ratio of 4-6:5-7:

2.

5. The UV-modified structural adhesive tape according to claim 4, characterized in that, The reaction includes the following steps: First, dehydrate poly(neopentyl terephthalate) diol under vacuum at 110℃~120℃ for 1.5h~2h, cool down to below 80℃, add diisocyanate, heat up to 80℃~82℃ and react for 3h~3.5h, then cool down to 70℃~72℃, add hydroxyethyl methacrylate, and react for 4.5h~5h to obtain polyurethane oligomer.

6. The UV-modified structural adhesive tape according to claim 4, characterized in that, The diisocyanate is selected from one or more of isophorone diisocyanate, hexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and diphenylmethane diisocyanate-50.

7. The UV-modified structural adhesive tape according to claim 1, characterized in that, The photoinitiator is composed of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and 1-hydroxycyclohexyl-phenyl ketone, wherein the mass ratio of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide to 1-hydroxycyclohexyl-phenyl ketone is 2:0.8 to 1.

2. The acryloyloxycarboxylic acid derivative is one or more of β-acryloyloxypropionic acid, acryloyloxybutyric acid, methacryloyloxypropionic acid, and methacryloyloxybutyric acid. The acryloyloxyethyl phosphate derivative is one or more of methacryloyloxyethyl phosphate, acryloyloxyethyl dimethyl phosphate, methacryloyloxyethyl dimethyl phosphate, and acryloyloxyethyl phenyl phosphate; The bifunctional acrylic monomer is one or more of ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, cyclohexanediethanol diacrylate, and cyclohexanediethanol dimethacrylate.

8. A method for preparing a UV-adhesive structural adhesive tape as described in any one of claims 1 to 7, characterized in that, Includes the following steps: (1) Mix the raw materials in the UV tack-enhancing structural adhesive tape according to the mass parts described in claim 1 under light-protected conditions, and dilute with an organic solvent to a solid content of 30% to 50% to obtain UV tack-enhancing structural adhesive. (2) Dilute the UV-tackified structural adhesive with an organic solvent to the coating viscosity, and coat it onto the corona surface of the substrate layer under light-protected conditions; (3) The adhesive is dried in stages to remove organic solvents. A release film is then laminated onto the dried adhesive layer and stored away from light to obtain UV-enhanced structural adhesive tape.

9. The UV-modified structural adhesive tape according to claim 8, characterized in that, The temperature of the segmented drying is 60℃~120℃, and the time of the segmented drying is 3min~5min; the organic solvent is one or more of toluene, ethyl acetate and methyl ethyl ketone; the coating viscosity is 300 mPa·s~500 mPa·s; and the dry adhesive thickness of the UV tackifying structural adhesive layer is 30μm~80μm.

10. The application of the UV-adhesive structural adhesive tape according to any one of claims 1 to 7 or the UV-adhesive structural adhesive tape prepared by the preparation method according to claim 8 or 9 in the bonding and fixing of metal substrates or polyimide substrates.

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