High-flexibility acrylic UV adhesive and preparation process thereof

Abstract

The invention relates to a high-flexibility acrylic UV adhesive and a preparation process thereof, and relates to the technical field of adhesives. The UV-curable UV-curable coating is prepared from the following components in parts by mass: 30 to 40 parts of epoxy acrylate, 10 to 20 parts of urethane acrylate, 15 to 25 parts of modified acrylate, 5 to 10 parts of functional monomer, 1 to 2 parts of photoinitiator, 0.8 to 1.2 parts of antioxidant, 0.5 to 0.8 part of light stabilizer, 0.3 to 0.5 part of flatting agent and 0.3 to 0.5 part of defoaming agent, the modified acrylic ester is obtained by mixing polyether modified acrylic ester and heptadecaethoxy bisphenol A dimethacrylate; the functional monomer comprises lauric acid acrylate. The preparation process comprises the following steps: mixing the raw materials, heating and stirring for reaction, cooling, adding the photoinitiator under a dark condition, carrying out vacuum defoaming, filtering and discharging to obtain the high-flexibility acrylic UV adhesive. The acrylic acid UV adhesive has the effect of improving the flexibility, the adhesion property and the weather resistance of the acrylic acid UV adhesive.

Description

Technical Field

[0001] This application relates to the field of adhesive technology, and in particular to a highly flexible acrylic UV adhesive and its preparation process. Background Technology

[0002] UV adhesives, widely used in numerous industrial sectors, are becoming increasingly important as industries demand higher product performance and quality. In fields such as electronic equipment assembly, optical device manufacturing, and medical device production, UV adhesives, with their rapid curing and environmentally friendly characteristics, improve production efficiency and product quality. They enable precise bonding and sealing of components, ensuring product stability and reliability, and driving technological progress and development in these industries.

[0003] In traditional UV adhesive preparation, a common practice is to use a single type of acrylate, such as ordinary epoxy acrylate or polyurethane acrylate, as the main component. These single types of acrylates are widely available, relatively inexpensive, and easy to obtain and process. Simultaneously, by combining them with some common photoinitiators and a small amount of additives, UV adhesives can be prepared through a simple mixing process. This conventional method can meet basic bonding requirements to a certain extent and is widely used in some applications where performance requirements are not particularly stringent. In addition, some existing UV adhesives may contain general-purpose plasticizers to improve their flexibility, but the effect is often limited.

[0004] However, traditional UV adhesive preparation methods have significant drawbacks. Because they use a single type of acrylate, there is a lack of synergistic effects between different components, making it difficult to simultaneously achieve both flexibility and aging resistance. Even with the addition of plasticizers, flexibility can only be improved to a certain extent, and they may adversely affect aging resistance, leading to problems such as cracking and aging during long-term use. This makes them unsuitable for applications with high performance requirements and thus requires improvement. Summary of the Invention

[0005] To improve the flexibility of acrylic UV adhesives, this application provides a highly flexible acrylic UV adhesive and its preparation process.

[0006] The technical solution for the high-flexibility acrylic UV adhesive and its preparation process provided in this application is as follows: Firstly, this application provides a highly flexible acrylic UV adhesive, which adopts the following technical solution: A highly flexible acrylic UV adhesive comprises the following components in parts by weight: 30-40 parts of epoxy acrylate 10-20 parts of polyurethane acrylate 15-25 parts of modified acrylate 5-10 parts of functional monomers 1-2 parts of photoinitiator Antioxidant 0.8-1.2 parts Light stabilizer 0.5-0.8 parts Leveling agent 0.3-0.5 parts 0.3-0.5 parts of defoamer; The modified acrylate is obtained by mixing polyether-modified acrylate and heptadecaethoxybisphenol A dimethacrylate; The functional monomers include laurate acrylate.

[0007] Modified acrylates combine the dynamic flexibility of polyether segments with the rigidity of the bisphenol backbone to form a microphase-separated network structure with alternating soft and hard phases, endowing the material with excellent molecular chain flexibility and appropriate crosslinking density, thereby significantly improving the flexibility of the adhesive layer. Epoxy acrylates and polyurethane acrylates are compounded to construct the basic resin network. The introduction of long-chain functional monomers further reduces the crosslinking density, alleviates internal stress concentration through steric hindrance, avoids interfacial peeling failure, and improves adhesion performance. Combined with the synergistic effect of antioxidants and light stabilizers, they effectively inhibit the damage of molecular chains to photo-oxidative aging and enhance weather resistance. Leveling agents, defoamers, and other additives optimize the interfacial tension and workability of the adhesive, enabling the adhesive to effectively wet various substrates. They enhance interfacial adhesion through intermolecular forces and chemical bonds, thereby improving adhesion performance. The above components work together synergistically, through multiple mechanisms such as flexible segment synergistic winding, aging-resistant system construction, and interfacial strengthening, to improve the flexibility, adhesion, and weather resistance of acrylic UV adhesives.

[0008] Preferably, the mass ratio of the polyether-modified acrylate to heptadecaethoxybisphenol A dimethacrylate is (2.5-3.5):1.

[0009] The flexible segments of polyether-modified acrylate and the long-chain structure of heptadecaethoxybisphenol A dimethacrylate form a stable molecular-level entangled network in an appropriate ratio, effectively reducing the rigidity of the system and enhancing the mobility of molecular chain segments. This allows the adhesive layer to absorb stress through chain segment sliding under load, thereby improving flexibility. At the same time, the polar groups and steric hindrance effects of the two components work together in this ratio to improve the wettability of the adhesive to substrates such as metals, glass, and plastics, promote the formation of intermolecular forces (such as hydrogen bonds and van der Waals forces) between the adhesive layer and the substrate surface, strengthen interfacial adhesion strength, and improve adhesion performance. The stable aromatic ring structure of bisphenol A can effectively shield free radical attacks caused by ultraviolet radiation, while the hydrophobic ether bonds of the polyether chain inhibit hydrolytic aging caused by water penetration. The two work synergistically to form a dense weather-resistant protective layer on the material surface, delaying photo-oxidative degradation and yellowing, and improving the weather resistance of the UV adhesive.

[0010] Preferably, the functional monomer further includes polyethylene glycol diacrylate.

[0011] The polyether segments of polyethylene glycol diacrylate construct a dynamic cross-linked network through the flexible rotational properties of ether bonds, endowing the material with excellent deformation recovery capabilities. Meanwhile, the long alkyl side chains of laurate acrylate reduce the cross-linking density through steric hindrance, alleviating internal stress concentration. The synergistic effect of these two components forms a composite mechanism of elastic framework and stress buffer at the microscopic level, maintaining the structural stability of the material under repeated deformation while avoiding the risk of brittle fracture caused by excessive cross-linking, thus improving flexibility. The highly polar ether oxygen groups of the polyethylene glycol segments interact through hydrogen bonding... It enhances the chemical bonding force with hydrophilic substrates such as metals and glass, while the hydrophobic alkyl chains of laurate acrylate improve the wetting and penetration ability of non-polar materials such as polyolefins and rubber. This polar gradient distribution characteristic improves the adhesion performance of UV adhesives. The regular ether bond structure of polyethylene glycol chains inhibits hydrolytic aging caused by water penetration through hydrophobic interaction. At the same time, the tight arrangement of its molecular chains reduces the migration path of free radicals. Together with the alkyl chains of laurate acrylate, it forms a UV shielding layer, which effectively blocks the erosion of the main chain structure by photo-oxidation reaction and improves weather resistance.

[0012] Preferably, the mass ratio of laurate acrylate to polyethylene glycol diacrylate is 1:(0.45-0.65).

[0013] The functional monomers compounded according to the above mass ratio can effectively synergistically improve the adhesion, weather resistance and flexibility of UV adhesives.

[0014] Preferably, the raw materials for preparing the acrylic UV adhesive further include carbon nanotube-supported titanium dioxide, prepared using the following steps: Tetrabutyl titanate was prepared as a titanium dioxide precursor solution, carbon nanotube dispersion was added, benzyl alcohol was added, the reaction was heated, and then the solution was centrifuged, washed, dried, and calcined to obtain carbon nanotube-supported titanium dioxide.

[0015] Carbon nanotubes, with their high specific surface area and mechanical strength due to their one-dimensional tubular structure, form a three-dimensional through-framework through π-π conjugation, which not only improves the tear resistance of the colloid but also promotes the energy transfer efficiency of the photoinitiator through electronic conduction pathways. Titanium dioxide is grown in situ on the surface of carbon nanotubes through the hydrolysis of tetrabutyl titanate, forming an anatase crystal structure. This structure not only acts as a UV shield to block free radical chain reactions but also decomposes organic matter on the surface of the colloid under light through photocatalytic activity, delaying yellowing and mechanical degradation. Benzyl alcohol regulates the hydrolysis rate of the titanium dioxide precursor through hydroxyl coordination, causing the nanoparticles to be oriented along the carbon nanotube axis, forming a core-shell composite structure. This heterogeneous interface enhances the compatibility with the acrylate matrix through the dual effects of chemical bonding and mechanical interlocking, which not only alleviates internal stress concentration and improves flexibility but also enhances the hydrogen bonding strength with the substrate through the polar surface of titanium dioxide. The calcination process further optimizes the interfacial bonding strength between titanium dioxide crystals and carbon nanotubes, forming a stable photo-thermal synergistic protection system and improving the flexibility and weather resistance of the UV adhesive.

[0016] Preferably, the amount of titanium dioxide supported on the carbon nanotubes is 1-2 parts.

[0017] The addition of carbon nanotube-loaded titanium dioxide in the above-mentioned proportions can effectively improve the flexibility and weather resistance of UV adhesives.

[0018] Preferably, the carbon nanotube-supported titanium dioxide is modified and prepared using the following steps: Carbon nanotube-supported titanium dioxide and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane were mixed in a solvent, the pH was adjusted to acidic, the reaction was heated and stirred, and the mixture was centrifuged, washed and dried to obtain modified carbon nanotube-supported titanium dioxide.

[0019] Aminosilanes form a dense coating layer on the surface of titanium dioxide supported on carbon nanotubes through a hydrolysis-condensation reaction. The terminal amino groups undergo Michael addition reactions with the acrylate double bonds, achieving covalent bonding between the inorganic and organic phases. Simultaneously, the three-dimensional conductive network of carbon nanotubes inhibits the oxidative degradation of the resin matrix by photogenerated holes through electron transfer effects, while the flexible spacers of the long silane chains alleviate interfacial stress concentration and improve the weather resistance of the UV adhesive. The synergistic effect of these two factors enhances the flexibility, weather resistance, and adhesion properties of the UV adhesive.

[0020] Preferably, the photoinitiator comprises 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone.

[0021] Preferably, the antioxidant includes hindered phenolic antioxidants, and the light stabilizer includes triazine ultraviolet absorbers.

[0022] Secondly, this application provides a preparation process for a highly flexible acrylic UV adhesive, which adopts the following technical solution: A preparation process for a highly flexible acrylic UV adhesive includes the following steps: Epoxy acrylate, polyurethane acrylate and modified acrylate are mixed and stirred. Functional monomers, antioxidants, light stabilizers, leveling agents and defoamers are added in sequence. The mixture is heated and stirred to react. After cooling, a photoinitiator is added under light-protected conditions. After vacuum degassing, the mixture is filtered to obtain a highly flexible acrylic UV adhesive.

[0023] The acrylic UV adhesive prepared according to the above steps has good flexibility, adhesion and weather resistance, and can maintain good working performance for a long time in high-performance scenarios.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. Modified acrylates combine the dynamic flexibility of polyether segments with the rigidity of the bisphenol backbone to form a microphase-separated network structure with alternating soft and hard phases, endowing the material with excellent molecular chain flexibility and appropriate crosslinking density, thereby significantly improving the flexibility of the adhesive layer. Epoxy acrylates and polyurethane acrylates are compounded to construct the basic resin network. The introduction of long-chain functional monomers further reduces the crosslinking density, alleviates internal stress concentration through steric hindrance, avoids interfacial peeling failure, and improves adhesion performance. Combined with the synergistic effect of antioxidants and light stabilizers, they effectively inhibit the damage of molecular chains to photo-oxidative aging and enhance weather resistance. Leveling agents, defoamers, and other additives optimize the interfacial tension and workability of the adhesive, enabling the adhesive to effectively wet various substrates. They enhance interfacial adhesion through intermolecular forces and chemical bonds, thereby improving adhesion performance. The above components work together synergistically, through multiple mechanisms such as flexible segment synergistic winding, aging-resistant system construction, and interfacial strengthening, to improve the flexibility, adhesion, and weather resistance of acrylic UV adhesives.

[0025] 2. The polyether segments of polyethylene glycol diacrylate construct a dynamic cross-linked network through the flexible rotational properties of ether bonds, endowing the material with excellent deformation recovery ability. Meanwhile, the long alkyl side chains of laurate acrylate reduce the cross-linking density through steric hindrance, alleviating internal stress concentration. The synergistic effect of these two components forms a composite mechanism of elastic framework and stress buffer at the microscopic level, maintaining the structural stability of the material under repeated deformation while avoiding the risk of brittle fracture caused by excessive cross-linking, thus improving flexibility. The highly polar ether oxygen groups of the polyethylene glycol segments act through hydrogen bonds... The UV adhesive enhances the chemical bonding with hydrophilic substrates such as metals and glass, while the hydrophobic alkyl chains of laurate acrylate improve the wetting and penetration ability of non-polar materials such as polyolefins and rubber. This polar gradient distribution characteristic improves the adhesion performance of the UV adhesive. The regular ether bond structure of polyethylene glycol chain inhibits hydrolytic aging caused by water penetration through hydrophobic interaction. At the same time, the tight arrangement of its molecular chains reduces the migration path of free radicals. Together with the alkyl chains of laurate acrylate, it forms a UV shielding layer, which effectively blocks the photo-oxidation reaction from eroding the main chain structure and improves weather resistance.

[0026] 3. Carbon nanotubes, with their high specific surface area and mechanical strength due to their one-dimensional tubular structure, form a three-dimensional through-framework through π-π conjugation, which not only improves the tear resistance of the colloid but also promotes the energy transfer efficiency of the photoinitiator through electronic conduction pathways. Titanium dioxide is grown in situ on the surface of carbon nanotubes through the hydrolysis of tetrabutyl titanate, forming an anatase crystal structure. This structure not only acts as a UV shield to block free radical chain reactions but also decomposes organic matter on the surface of the colloid under light through photocatalytic activity, delaying yellowing and mechanical degradation. Benzyl alcohol regulates the hydrolysis rate of the titanium dioxide precursor through hydroxyl coordination, causing the nanoparticles to be oriented along the carbon nanotube axis, forming a core-shell composite structure. This heterogeneous interface enhances the compatibility with the acrylate matrix through the dual effects of chemical bonding and mechanical interlocking, which not only alleviates internal stress concentration and improves flexibility but also enhances the hydrogen bonding strength with the substrate through the polar surface of titanium dioxide. The calcination process further optimizes the interfacial bonding strength between titanium dioxide crystals and carbon nanotubes, forming a stable photo-thermal synergistic protection system and improving the flexibility and weather resistance of the UV adhesive. Detailed Implementation

[0027] This application discloses a highly flexible acrylic UV adhesive and its preparation process. Unless otherwise specified, all raw materials used in this application are commercially available. The following examples further illustrate this application in detail: Raw material specifications: Heptadecaethoxybisphenol A dimethacrylate (CAS No.: 41637-38-1), purchased from Guangdong Yuhe New Materials Co., Ltd.; ethyl acetate (CAS No.: 141-78-6); methyl isobutyl ketone (CAS No.: 108-10-1); epoxy acrylate (Zhanxin EB 6040); polyurethane acrylate (EBECRYL 230); polyether-modified acrylate (EB). 80. Purchased from Shanghai Zhenlishi Network Technology Co., Ltd.: Laurate acrylate (CAS No.: 2156-97-0), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (CAS No.: 75980-60-8), 1-hydroxycyclohexylphenyl ketone (CAS No.: 947-19-3), antioxidant 1010 (CAS No.: 6683-19-8), light stabilizer UV-400 (CAS No.: 153519-44-9), leveling agent BYK-358N, purchased from Foshan Pingshenghua. The following products were purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.: defoamer BYK-1790 (purchased from Shanghai Kaiyin Chemical Co., Ltd.), polyethylene glycol diacrylate (CAS No.: 26570-48-9) (purchased from Ba Shifu (Shanghai) Biomedical Technology Co., Ltd.), carbon nanotubes (item number 100252) (purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.), tetrabutyl titanate (CAS No.: 109-46-6), benzyl alcohol (CAS No.: 100-51-6), and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (CAS No.: 1760-24-3).

[0028] Example 1 Preparation of polyether-modified acrylates Polyether-modified acrylate and heptadecaethoxybisphenol A dimethacrylate were vacuum dried at 50°C for 2 hours. Under nitrogen protection, they were mixed in a solvent at a mass ratio of 2.5:1 (ethyl acetate and methyl isobutyl ketone volume ratio of 6:4), with a solid content of 40%. The mixture was stirred at 200 rpm at 50°C for 30 minutes to obtain a mixture. The mixture was then circulated 5 times using a high-shear homogenizer at a speed of 18 m / s, with each cycle lasting 30 seconds. The temperature was increased from 25°C to 60°C at a rate of 5°C / h and held for 1 hour. The mixture was stirred at 100 rpm to promote chain rearrangement. The solvent was removed by vacuum distillation to obtain the modified acrylate.

[0029] Preparation of highly flexible acrylic UV adhesive Weigh out 30 parts epoxy acrylate, 10 parts polyurethane acrylate, 15 parts modified acrylate, 5 parts functional monomer, 1 part photoinitiator, 0.8 parts antioxidant, 0.5 parts light stabilizer, 0.3 parts leveling agent, and 0.3 parts defoamer. The functional monomer is lauric acid acrylate. The photoinitiator is composed of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a mass ratio of 3:2. The antioxidant is antioxidant 1010, the light stabilizer is UV-400, the leveling agent is BYK-358N, and the defoamer is BYK-1790.

[0030] Epoxy acrylate, polyurethane acrylate and modified acrylate were mixed and stirred at 400 rpm for 20 min at 50 °C. Functional monomers, antioxidants, light stabilizers, leveling agents and defoamers were added in sequence. The mixture was heated to 60 °C and stirred at 200 rpm for 1 h. The mixture was then cooled to below 30 °C and a photoinitiator was added under light-protected conditions. After vacuum degassing at -0.08 MPa for 15 min, the mixture was filtered to obtain a highly flexible acrylic UV adhesive.

[0031] Example 2 Preparation of polyether-modified acrylates Polyether-modified acrylate and heptadecaethoxybisphenol A dimethacrylate were vacuum dried at 50°C for 2 hours. Under nitrogen protection, they were mixed in a solvent at a mass ratio of 3.5:1 (ethyl acetate and methyl isobutyl ketone volume ratio of 6:4), with a solid content of 40%. The mixture was stirred at 200 rpm at 50°C for 30 minutes to obtain a mixture. The mixture was then circulated 5 times using a high-shear homogenizer at a speed of 18 m / s, with each cycle lasting 30 seconds. The temperature was increased from 25°C to 60°C at a rate of 5°C / h and held for 1 hour. The mixture was stirred at 100 rpm to promote chain rearrangement. The solvent was removed by vacuum distillation to obtain the modified acrylate.

[0032] Preparation of highly flexible acrylic UV adhesive Weigh out 40 parts epoxy acrylate, 20 parts polyurethane acrylate, 25 parts modified acrylate, 10 parts functional monomer, 2 parts photoinitiator, 1.2 parts antioxidant, 0.8 parts light stabilizer, 0.5 parts leveling agent, and 0.5 parts defoamer. The functional monomer is lauric acid acrylate. The photoinitiator is composed of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a mass ratio of 3:2. The antioxidant is antioxidant 1010, the light stabilizer is UV-400, the leveling agent is BYK-358N, and the defoamer is BYK-1790.

[0033] Epoxy acrylate, polyurethane acrylate and modified acrylate were mixed and stirred at 400 rpm for 20 min at 50 °C. Functional monomers, antioxidants, light stabilizers, leveling agents and defoamers were added in sequence. The mixture was heated to 60 °C and stirred at 200 rpm for 1 h. The mixture was then cooled to below 30 °C and a photoinitiator was added under light-protected conditions. After vacuum degassing at -0.08 MPa for 15 min, the mixture was filtered to obtain a highly flexible acrylic UV adhesive.

[0034] Example 3 Preparation of polyether-modified acrylates Polyether-modified acrylate and heptadecaethoxybisphenol A dimethacrylate were vacuum dried at 50°C for 2 hours. Under nitrogen protection, they were mixed in a 3:1 mass ratio and added to a solvent (ethyl acetate and methyl isobutyl ketone in a 6:4 volume ratio), with a solid content of 40%. The mixture was stirred at 200 rpm at 50°C for 30 minutes to obtain a mixture. The mixture was then circulated five times using a high-shear homogenizer at 18 m / s, with each cycle lasting 30 seconds. The temperature was increased from 25°C to 60°C at a rate of 5°C / h and held for 1 hour. The mixture was stirred at 100 rpm to promote chain rearrangement. The solvent was removed by vacuum distillation to obtain the modified acrylate.

[0035] Preparation of highly flexible acrylic UV adhesive Weigh out 35 parts epoxy acrylate, 15 parts polyurethane acrylate, 20 parts modified acrylate, 7.5 parts functional monomer, 1.5 parts photoinitiator, 1 part antioxidant, 0.65 parts light stabilizer, 0.4 parts leveling agent, and 0.4 parts defoamer. The functional monomer is lauric acid acrylate. The photoinitiator is composed of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a mass ratio of 3:2. The antioxidant is antioxidant 1010, the light stabilizer is UV-400, the leveling agent is BYK-358N, and the defoamer is BYK-1790.

[0036] Epoxy acrylate, polyurethane acrylate and modified acrylate were mixed and stirred at 400 rpm for 20 min at 50 °C. Functional monomers, antioxidants, light stabilizers, leveling agents and defoamers were added in sequence. The mixture was heated to 60 °C and stirred at 200 rpm for 1 h. The mixture was then cooled to below 30 °C and a photoinitiator was added under light-protected conditions. After vacuum degassing at -0.08 MPa for 15 min, the mixture was filtered to obtain a highly flexible acrylic UV adhesive.

[0037] Example 4 Example 4 is based on Example 3. The only difference between Example 4 and Example 3 is that the mass ratio of polyether modified acrylate and heptadecaethoxybisphenol A dimethacrylate in Example 4 is 1:1.

[0038] Example 5 Example 5 is based on Example 3. The only difference between Example 5 and Example 3 is that the mass ratio of polyether modified acrylate and heptadecaethoxybisphenol A dimethacrylate in Example 5 is 5:1.

[0039] Example 6 Example 6 is based on Example 3. The only difference between Example 6 and Example 3 is that the functional monomer in Example 6 also includes polyethylene glycol diacrylate, and the mass ratio of laurate acrylate to polyethylene glycol diacrylate in the functional monomer is 1:0.45.

[0040] Preparation of highly flexible acrylic UV adhesive Weigh out 35 parts epoxy acrylate, 15 parts polyurethane acrylate, 20 parts modified acrylate, 7.5 parts functional monomer, 1.5 parts photoinitiator, 1 part antioxidant, 0.65 parts light stabilizer, 0.4 parts leveling agent, and 0.4 parts defoamer. The functional monomer is composed of lauric acid acrylate and polyethylene glycol diacrylate in a mass ratio of 1:0.45. The photoinitiator is composed of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a mass ratio of 3:2. The antioxidant is antioxidant 1010, the light stabilizer is UV-400, the leveling agent is BYK-358N, and the defoamer is BYK-1790.

[0041] Epoxy acrylate, polyurethane acrylate and modified acrylate were mixed and stirred at 400 rpm for 20 min at 50 °C. Functional monomers, antioxidants, light stabilizers, leveling agents and defoamers were added in sequence. The mixture was heated to 60 °C and stirred at 200 rpm for 1 h. The mixture was then cooled to below 30 °C and a photoinitiator was added under light-protected conditions. After vacuum degassing at -0.08 MPa for 15 min, the mixture was filtered to obtain a highly flexible acrylic UV adhesive.

[0042] Example 7 Example 7 is based on Example 3. The only difference between Example 7 and Example 3 is that the functional monomer in Example 7 also includes polyethylene glycol diacrylate, and the mass ratio of laurate acrylate to polyethylene glycol diacrylate in the functional monomer is 1:0.65.

[0043] Preparation of highly flexible acrylic UV adhesive Weigh out 35 parts epoxy acrylate, 15 parts polyurethane acrylate, 20 parts modified acrylate, 7.5 parts functional monomer, 1.5 parts photoinitiator, 1 part antioxidant, 0.65 parts light stabilizer, 0.4 parts leveling agent, and 0.4 parts defoamer. The functional monomer is composed of lauric acid acrylate and polyethylene glycol diacrylate in a mass ratio of 1:0.65. The photoinitiator is composed of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a mass ratio of 3:2. The antioxidant is antioxidant 1010, the light stabilizer is UV-400, the leveling agent is BYK-358N, and the defoamer is BYK-1790.

[0044] Epoxy acrylate, polyurethane acrylate and modified acrylate were mixed and stirred at 400 rpm for 20 min at 50 °C. Functional monomers, antioxidants, light stabilizers, leveling agents and defoamers were added in sequence. The mixture was heated to 60 °C and stirred at 200 rpm for 1 h. The mixture was then cooled to below 30 °C and a photoinitiator was added under light-protected conditions. After vacuum degassing at -0.08 MPa for 15 min, the mixture was filtered to obtain a highly flexible acrylic UV adhesive.

[0045] Example 8 Example 8 is based on Example 3. The only difference between Example 8 and Example 3 is that the functional monomer in Example 8 also includes polyethylene glycol diacrylate, and the mass ratio of laurate acrylate to polyethylene glycol diacrylate in the functional monomer is 1:0.55.

[0046] Preparation of highly flexible acrylic UV adhesive Weigh out 35 parts epoxy acrylate, 15 parts polyurethane acrylate, 20 parts modified acrylate, 7.5 parts functional monomer, 1.5 parts photoinitiator, 1 part antioxidant, 0.65 parts light stabilizer, 0.4 parts leveling agent, and 0.4 parts defoamer. The functional monomer is composed of lauric acid acrylate and polyethylene glycol diacrylate in a mass ratio of 1:0.55. The photoinitiator is composed of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a mass ratio of 3:2. The antioxidant is antioxidant 1010, the light stabilizer is UV-400, the leveling agent is BYK-358N, and the defoamer is BYK-1790.

[0047] Epoxy acrylate, polyurethane acrylate and modified acrylate were mixed and stirred at 400 rpm for 20 min at 50 °C. Functional monomers, antioxidants, light stabilizers, leveling agents and defoamers were added in sequence. The mixture was heated to 60 °C and stirred at 200 rpm for 1 h. The mixture was then cooled to below 30 °C and a photoinitiator was added under light-protected conditions. After vacuum degassing at -0.08 MPa for 15 min, the mixture was filtered to obtain a highly flexible acrylic UV adhesive.

[0048] Example 9 Example 9 is based on Example 8. The only difference between Example 9 and Example 8 is that in Example 9, the mass ratio of laurate acrylate to polyethylene glycol diacrylate in the functional monomer is 1:0.3.

[0049] Example 10 Example 10 is based on Example 8. The only difference between Example 10 and Example 8 is that in Example 10, the mass ratio of laurate acrylate to polyethylene glycol diacrylate in the functional monomer is 1:0.8.

[0050] Example 11 Example 11 is based on Example 3. The only difference between Example 11 and Example 3 is that the functional monomer in Example 11 is polyethylene glycol diacrylate.

[0051] Preparation of highly flexible acrylic UV adhesive Weigh out 35 parts epoxy acrylate, 15 parts polyurethane acrylate, 20 parts modified acrylate, 7.5 parts functional monomer, 1.5 parts photoinitiator, 1 part antioxidant, 0.65 parts light stabilizer, 0.4 parts leveling agent, and 0.4 parts defoamer. The functional monomer is polyethylene glycol diacrylate. The photoinitiator is composed of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a mass ratio of 3:2. The antioxidant is antioxidant 1010, the light stabilizer is UV-400, the leveling agent is BYK-358N, and the defoamer is BYK-1790.

[0052] Epoxy acrylate, polyurethane acrylate and modified acrylate were mixed and stirred at 400 rpm for 20 min at 50 °C. Functional monomers, antioxidants, light stabilizers, leveling agents and defoamers were added in sequence. The mixture was heated to 60 °C and stirred at 200 rpm for 1 h. The mixture was then cooled to below 30 °C and a photoinitiator was added under light-protected conditions. After vacuum degassing at -0.08 MPa for 15 min, the mixture was filtered to obtain a highly flexible acrylic UV adhesive.

[0053] Example 12 Example 12 is based on Example 3. The only difference between Example 12 and Example 3 is that the raw materials for preparing the acrylic UV adhesive in Example 12 also include 1 part of carbon nanotube-supported titanium dioxide, and it is prepared using the following steps: Carbon nanotubes were added to anhydrous ethanol and sonicated for 30 min to obtain a carbon nanotube dispersion. Tetrabutyl titanate, glacial acetic acid, and anhydrous ethanol were mixed at a mass ratio of 1:1:15 and stirred at 200 rpm for 30 min to obtain a titanium dioxide precursor solution. After adding the carbon nanotube dispersion, benzyl alcohol was added, with a mass ratio of carbon nanotubes, benzyl alcohol, and titanium dioxide precursor solution of 1:300:150. The mixture was reacted in an oil bath at 180 °C for 12 h, washed by centrifugation with ethanol and deionized water, dried under vacuum at 60 °C, and calcined at 450 °C for 2 h in an oxygen atmosphere. After cooling, carbon nanotube-loaded titanium dioxide was obtained.

[0054] Example 13 Example 13 is based on Example 12. The only difference between Example 13 and Example 12 is that Example 13 adds two copies. Titanium dioxide supported on carbon nanotubes.

[0055] Example 14 Example 14 is based on Example 12. The only difference between Example 14 and Example 12 is that 1.5 parts of carbon nanotube-supported titanium dioxide are added in Example 14.

[0056] Example 15 Example 15 is based on Example 12, the only difference between Example 15 and Example 12 is that 5 additional parts are added to Example 15. Titanium dioxide supported on carbon nanotubes.

[0057] Example 16 Example 16 is based on Example 12. The only difference between Example 16 and Example 12 is that the carbon nanotube-supported titanium dioxide in Example 16 has undergone modification treatment and is prepared using the following steps: The solvent consists of anhydrous ethanol and deionized water in a volume ratio of 4:1.

[0058] Carbon nanotube-supported titanium dioxide and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane were mixed in a solvent at a mass ratio of 1:0.02:50. The pH was adjusted to 4.5 with 0.1 mol / L hydrochloric acid, and the mixture was stirred at 200 rpm for 2 h at 80 °C. After centrifugation and washing with deionized water, the mixture was dried under vacuum at 60 °C to obtain modified carbon nanotube-supported titanium dioxide.

[0059] Comparative Example 1 Comparative Example 1 is based on Example 3. The only difference between Comparative Example 1 and Example 3 is that the modified acrylate is replaced with polyether modified acrylate in Comparative Example 1.

[0060] Preparation of highly flexible acrylic UV adhesive Weigh out 35 parts epoxy acrylate, 15 parts polyurethane acrylate, 20 parts polyether modified acrylate, 7.5 parts functional monomer, 1.5 parts photoinitiator, 1 part antioxidant, 0.65 parts light stabilizer, 0.4 parts leveling agent, and 0.4 parts defoamer. The functional monomer is lauric acid acrylate. The photoinitiator is composed of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a mass ratio of 3:2. The antioxidant is antioxidant 1010, the light stabilizer is UV-400, the leveling agent is BYK-358N, and the defoamer is BYK-1790.

[0061] Epoxy acrylate, polyurethane acrylate and polyether-modified acrylate were mixed and stirred at 400 rpm for 20 min at 50 °C. Functional monomers, antioxidants, light stabilizers, leveling agents and defoamers were added in sequence. The mixture was heated to 60 °C and stirred at 200 rpm for 1 h. The mixture was then cooled to below 30 °C and a photoinitiator was added under light-protected conditions. After vacuum degassing at -0.08 MPa for 15 min, the mixture was filtered to obtain a highly flexible acrylic UV adhesive.

[0062] Performance testing (1) Using GB / T 2791-1995 "Test Method for Peel Strength of Adhesives (Flexible Materials to Flexible Materials)" and GB / T 1865-2009 "Artificial Weathering and Artificial Radiation Exposure of Paints and Varnishes" as standards, the glass velocity was set to 100 mm / min. The samples were placed in a QUV accelerated aging test chamber with a UV-A light source (340 nm) and an irradiation intensity of 0.76 W / m². 2 After being treated with 60℃ light and 50℃ condensation cycle (8h light + 4h condensation) for 1000h, the T-peel strength of the samples before and after aging was tested and the retention rate was calculated. Three samples were prepared for each sample, and the average value was taken after measurement. The results are recorded in Table 1.

[0063] (2) Select GB / T 528-2009 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber as the standard, prepare long strip specimens (dumbbell type), stretch them at a rate of 500 mm / min until they break, calculate the elongation, prepare three samples for each specimen, take the average value after measurement, and record the results in Table 1.

[0064] Table 1. Test results of adhesion, weather resistance and flexibility of acrylic UV adhesive. As shown in Table 1, the T-peel strength of Examples 1-3 is greater than 4.6%, the strength retention rate after aging is greater than 89.6%, and the elongation at break is greater than 325%, which shows that the acrylic UV adhesive prepared in this application has good flexibility, adhesion and weather resistance.

[0065] As shown in Table 1, the only difference between Examples 4 and 5 and Example 3 is that the mass ratio of polyether-modified acrylate to heptadeceoxybisphenol A dimethacrylate in Example 4 is 1:1, while the mass ratio of polyether-modified acrylate to heptadeceoxybisphenol A dimethacrylate in Example 5 is 5:1. Compared with Example 3, the performance of Examples 4 and 5 is reduced. This is because the mass ratio of polyether-modified acrylate to heptadeceoxybisphenol A dimethacrylate disrupts the optimal ratio range, and the imbalance between the number of rigid and flexible segments leads to a decrease in the stability of the molecular chain, thus resulting in a decrease in performance.

[0066] As shown in Table 1, the only difference between Examples 6-11 and Example 3 is that: in Examples 6-8, polyethylene glycol diacrylate and lauric acid acrylate were used in a synergistic effect and were compounded in the optimal ratio, which effectively improved the flexibility, weather resistance and adhesion of the UV adhesive; Examples 9 and 10 deviated from the optimal ratio, and the performance decreased; in Example 11, lauric acid acrylate was replaced with polyethylene glycol diacrylate, and the performance decreased because the synergistic effect of the two was lacking, and the single polyethylene glycol diacrylate led to a decrease in polarity, decreased adhesion and weather resistance, and too many flexible segments led to a loose structure and excessively high elongation at break.

[0067] As shown in Table 1, the only difference between Examples 12-16 and Example 3 is that: in Examples 12-14, the addition of carbon nanotube-supported titanium dioxide within a limited dosage range can effectively strengthen the internal structure and improve performance; in Example 15, the optimal dosage range was disrupted, and excessive addition can easily lead to agglomeration and performance decline; in Example 16, the carbon nanotube-supported titanium dioxide was further modified to improve interfacial compatibility and further improve performance.

[0068] As shown in Table 1, the only difference between Comparative Example 1 and Example 3 is that the modified acrylate in Comparative Example 1 was replaced with polyether modified acrylate. Compared with Example 3, the performance of Comparative Example 1 was significantly reduced. This is because the lack of modified groups reduced the interfacial bonding force and limited the plastic deformation of the single polyether segment, thus resulting in a significant decrease in performance.

[0069] This specific embodiment is merely an explanation of this application and is not intended to limit it. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this application. The technical scope of this application is not limited to the contents of the specification but must be determined according to the scope of the claims.

Claims

1. A highly flexible acrylic UV adhesive, characterized in that: The components include the following parts by mass: 30-40 parts of epoxy acrylate 10-20 parts of polyurethane acrylate 15-25 parts of modified acrylate 5-10 parts of functional monomers 1-2 parts of photoinitiator Antioxidant 0.8-1.2 parts Light stabilizer 0.5-0.8 parts Leveling agent 0.3-0.5 parts 0.3-0.5 parts of defoamer; The modified acrylate is obtained by mixing polyether-modified acrylate and heptadecaethoxybisphenol A dimethacrylate; The functional monomers include laurate acrylate.

2. The highly flexible acrylic UV adhesive according to claim 1, characterized in that: The mass ratio of the polyether-modified acrylate to heptadecaethoxybisphenol A dimethacrylate is (2.5-3.5):

1.

3. The highly flexible acrylic UV adhesive according to claim 1, characterized in that: The functional monomers also include polyethylene glycol diacrylate.

4. The highly flexible acrylic UV adhesive according to claim 3, characterized in that: The mass ratio of lauric acid acrylate to polyethylene glycol diacrylate is 1:(0.45-0.65).

5. The highly flexible acrylic UV adhesive according to claim 1, characterized in that: The acrylic UV adhesive also includes carbon nanotube-supported titanium dioxide as a raw material, and is prepared using the following steps: Tetrabutyl titanate was prepared as a titanium dioxide precursor solution, carbon nanotube dispersion was added, benzyl alcohol was added, the reaction was heated, and then the solution was centrifuged, washed, dried, and calcined to obtain carbon nanotube-supported titanium dioxide.

6. The highly flexible acrylic UV adhesive according to claim 5, characterized in that: The amount of titanium dioxide supported on the carbon nanotubes is 1-2 parts.

7. The highly flexible acrylic UV adhesive according to claim 6, characterized in that: The carbon nanotube-supported titanium dioxide was modified and prepared using the following steps: Carbon nanotube-supported titanium dioxide and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane were mixed in a solvent, the pH was adjusted to acidic, the reaction was heated and stirred, and then centrifuged, washed and dried to obtain modified carbon nanotube-supported titanium dioxide.

8. The highly flexible acrylic UV adhesive according to claim 1, characterized in that: The photoinitiator comprises 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone.

9. The highly flexible acrylic UV adhesive according to claim 1, characterized in that: The antioxidants include hindered phenolic antioxidants, and the light stabilizers include triazine ultraviolet absorbers.

10. A process for preparing a highly flexible acrylic UV adhesive as described in any one of claims 1-9, characterized in that: Includes the following steps: Epoxy acrylate, polyurethane acrylate and modified acrylate are mixed and stirred. Functional monomers, antioxidants, light stabilizers, leveling agents and defoamers are added in sequence. The mixture is heated and stirred to react. After cooling, a photoinitiator is added under light-protected conditions. After vacuum degassing, the mixture is filtered to obtain a highly flexible acrylic UV adhesive.

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