A low-temperature UV resistant adhesive for LCDs

Abstract

This invention discloses a low-temperature resistant UV adhesive for LCDs, which is made from polyether-type polyurethane acrylate, reactive diluent, low-temperature toughening agent, photoinitiator, silane coupling agent, and rheology modifier. This invention addresses the problems of current LCD UV adhesives, such as brittleness and cracking, interfacial debonding, optical performance degradation, and insufficient long-term reliability in extreme low-temperature environments. Through unique component design and synergistic effects, a novel UV adhesive is obtained that retains the original advantages of UV adhesives in terms of curing speed, bonding strength, optical transparency, and heat resistance, while maintaining good toughness, impact resistance, and interfacial bonding stability at temperatures from -40°C to even lower. It can meet the demanding application environment requirements of automotive electronics and outdoor displays in a wide temperature range (e.g., -40°C to 85°C), while maintaining good process adaptability and long-term durability.

Description

Technical Field

[0001] This invention belongs to the field of UV adhesive preparation technology, specifically relating to an ultraviolet (UV) curable adhesive with excellent low-temperature resistance for use in the manufacturing and assembly of liquid crystal display modules (LCD modules) and its preparation method. Background Technology

[0002] The manufacturing process of liquid crystal display modules involves various bonding and sealing processes, such as polarizer lamination, full lamination of the touch screen and display panel (OCA / OCR), bezel sealing, flexible circuit board (FPCB) fixing, and structural bonding between components. Ultraviolet (UV) curable adhesives are widely used in these processes due to their advantages, including fast curing speed, high production efficiency, low volatile organic compound (VOC) emissions, and high bonding precision.

[0003] With the development of display technology, the application scenarios of LCDs are constantly expanding to extreme environments, especially in automotive electronics (such as central control screens and dashboards), outdoor display devices, aerospace instruments, and mobile terminals used in high-altitude and cold regions. These applications require display modules to operate stably for extended periods in extremely low temperature environments (e.g., -30℃ to -50℃, or even lower) while maintaining reliable optical performance and mechanical integrity. Under such low-temperature conditions, conventional UV adhesives are prone to problems such as excessively high glass transition temperature (Tg) and material embrittlement due to reduced polymer chain mobility, leading to a series of failure risks: First, brittle cracking and interface debonding of the adhesive layer: Low temperatures cause a sharp increase in the adhesive modulus and a loss of toughness. When the module is subjected to assembly stress, vibration, or internal stress generated by thermal expansion and contraction, the adhesive layer is highly susceptible to brittle fracture or debonding from the interface of dissimilar materials such as glass, polycarbonate (PC), polymethyl methacrylate (PMMA), and metal, resulting in loosening, peeling, or... First, sealing failure; second, optical performance degradation: for optical applications such as full lamination, cracking or microcracks in the adhesive layer can cause light scattering, resulting in display defects such as white spots and bright lines. At the same time, the stress caused by the difference in the coefficient of thermal expansion between the adhesive layer and the substrate at low temperatures may lead to image distortion; third, long-term reliability decline: during repeated thermal cycling, the above-mentioned embrittlement effect will be accelerated and amplified. After multiple low-temperature-room-temperature cycles, the adhesive may suffer cumulative damage, and its bonding strength and sealing performance will be significantly reduced, failing to meet the reliability requirements for long-term use of the product.

[0004] Currently, common technical means to improve the low-temperature resistance of UV adhesives include adding flexible monomers (such as long-chain acrylates), using low-Tg polyurethane acrylate (PUA) resins, or incorporating physical plasticizers. However, these methods often have significant limitations when applied to LCD manufacturing, which demands stringent overall performance: First, the challenge of balancing performance: simply increasing flexibility significantly reduces the initial strength, modulus, and heat resistance of the adhesive, potentially leading to creep or softening during subsequent high-temperature processes or in high-temperature summer environments, failing to meet the requirements for use in a wide temperature range (e.g., -40℃ to 85℃); Second, interface compatibility and aging risks: physical plasticizers tend to migrate and precipitate, which may not only contaminate the liquid crystal cell or optical film layer, affecting display effects, but also cause the adhesive performance to deteriorate over time, resulting in unstable long-term low-temperature resistance; Third, curing shrinkage and internal stress: some flexible monomers or resins may increase curing volume shrinkage, exacerbating the mismatch between shrinkage and that of rigid substrates (such as glass) at low temperatures, generating greater interfacial internal stress and increasing the risk of debonding; Fourth, insufficient process adaptability: formulations adjusted to pursue low-temperature toughness may have viscosity, curing speed, and transmittance that are incompatible with the high-speed, precision LCD production line processes.

[0005] Therefore, there is an urgent need in this field to develop a new type of low-temperature resistant UV adhesive. This adhesive should significantly improve the toughness, crack resistance and interfacial bonding reliability at extreme low temperatures while maintaining the inherent high efficiency curing, high bonding strength and good optical properties of UV adhesives. At the same time, it should ensure stable performance over a wide temperature range and be able to adapt to the high standard process requirements of modern LCD manufacturing, so as to meet the growing application needs of high-end display products in harsh environments. Summary of the Invention

[0006] To address the problems of easy embrittlement and cracking, interface debonding, optical performance degradation, and insufficient long-term reliability of existing LCD UV adhesives under extreme low-temperature environments, this invention provides a novel LCD UV adhesive and its preparation method, which combines excellent low-temperature toughness, high and low temperature bonding reliability, good optical performance, and wide temperature range stability.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A low-temperature resistant UV adhesive for LCDs, based on a total mass percentage of 100%, contains the following raw materials and their respective mass percentages: Polyether-type polyurethane acrylate 30-60%, 30-50% reactive diluent Low-temperature toughening agent 5-20%, Photoinitiator 1-5%, Silane coupling agent 0.5-5%, Rheology modifier 0.1-0.5%.

[0008] Furthermore, the polyether-type polyurethane acrylate (PUA) is prepared by reacting polyether-type polyol with hexamethylene diisocyanate (HDI) and 2-hydroxyethyl acrylate (HEA) as raw materials; its glass transition temperature (Tg) is -40℃ to -50℃, and its chemical structural formula is: , Where n is an integer between 25 and 30; The polyether-type polyol is polypropylene glycol (PPG) or polytetrahydrofuran ether glycol (PTMEG), preferably with a number average molecular weight of 1000-2000.

[0009] Furthermore, the preparation of the polyether-type polyurethane acrylate includes the following steps: (1) Dehydration of polyether polyols The polyether polyol was dehydrated at 100-110℃ and under a vacuum of <0.1 MPa for 2 hours, and then cooled to 60℃ for later use. (2) Synthesis of prepolymer Under nitrogen protection, HDI and the catalyst dibutyltin dilaurate (DBTDL) were added to the dehydrated polyether polyol, and then the temperature was raised to 75±5℃ and the reaction was carried out for 2-3 hours. During this period, the NCO content was monitored by di-n-butylamine titration until it approached the theoretical value (about 5.2%), and a prepolymer with terminal NCO was obtained. (3) End-capping reaction The prepolymer obtained in step (2) was cooled to 50°C, and HEA and the polymerization inhibitor p-hydroxyanisole (MEHQ) were added. The reaction was continued at 50-60°C for 2-4 hours. The reaction was monitored by FTIR until the NCO reaction was complete (2270 cm⁻¹). -1 After the NCO characteristic peak disappears, heating is stopped, and the product is distilled under reduced pressure at 40-50 °C. Then, it is degassed under light-protected conditions to obtain a pale yellow to colorless and transparent viscous liquid product.

[0010] In step (2), the molar ratio of polyether polyol to HDI is 1:2.05, and the amount of DBTDL is 0.02~0.05% of the mass of polyether polyol used; in step (3), the molar ratio of HEA to NCO in the prepolymer is 1.05:1, and the amount of MEHQ is 0.1% of the mass of the prepolymer. Further, the reactive diluent is one or more of isobornyl acrylate, phenoxyethyl acrylate, lauryl acrylate, hydroxyethyl acrylate, cyclotrimethylolpropane methyl acetal acrylate, tripropylene glycol diacrylate, and ethoxylated bisphenol A diacrylate.

[0011] Further, the low-temperature toughening agent is one or more of the following: amino-terminated liquid nitrile rubber (ATBN, with a number average molecular weight of 3000-5000), carboxyl-terminated liquid polybutadiene rubber (CTPB, with a number average molecular weight of 3000-5000), lauryl acrylate, stearyl acrylate, octadecyl methacrylate, polyethylene glycol methyl ether methacrylate, and polypropylene glycol diacrylate.

[0012] Furthermore, the photoinitiator is one or more of α-hydroxy ketones (including 184, 1173, etc.), acylphosphine oxides (including TPO, 819), and benzoyl carboxyl esters (including MBF).

[0013] Further, the silane coupling agent is one or more of γ-glycidoxypropyltrimethoxysilane (including KH-560, A-187, 187), methacryloyloxypropyltrimethoxysilane (including KH-570, A-174, 174), and γ-aminopropyltriethoxysilane (including KH-550, A-1100).

[0014] Furthermore, the rheology modifier is a hydrophobic fumed silica, including one or more of AEROSIL R 972, R 974, and R812.

[0015] The UV adhesive is prepared by adding polyether-type polyurethane acrylate resin, low-temperature toughening agent, and 30% photoinitiator into a stirred tank under light-protected conditions. The mixture is stirred and mixed for 1-2 hours at 40-60℃ and a vacuum of -0.095MPa until the system is uniform and transparent. Then, the mixture is cooled to room temperature, and the remaining photoinitiator, reactive diluent, silane coupling agent, and rheology modifier are added. The mixture is stirred for another 0.5 hours, then discharged and filtered to obtain the final product.

[0016] The ester bonds of commonly used polyester polyols are prone to freezing at low temperatures and may hydrolyze. Compared with polyester polyols, polyether polyols have superior low-temperature toughness, flexibility, and hydrolysis resistance. This invention uses a polyether polyol (preferably PTMG) as the soft segment and proposes a special polyether polyurethane acrylate structure with extremely low rotational barriers within the ether bonds. Even in extremely low temperatures below -40°C, the molecular chain segments can still maintain their mobility, which is the fundamental reason why the resulting colloid possesses the "low-temperature resistance" property. This PUA molecular structure can be regarded as a "thermoplastic elastomer," in which the long polyether segments constitute a continuous flexible phase responsible for absorbing impact and low-temperature deformation; while the hard segments formed by isocyanate and acrylate end-capping agents aggregate to form dispersed rigid microregions that serve as physical crosslinking points, thereby maintaining elasticity and preventing brittleness at low temperatures.

[0017] Meanwhile, for LCD packaging (especially automotive display) applications, adhesives must maintain reliable performance across a wide temperature range, including extreme low temperatures (e.g., -40°C) and high temperatures (e.g., 85°C or 105°C). The PUA designed in this invention, with a Tg < -40°C, retains sufficient and moderate hard segment microregions in its molecular structure. These hard segment microregions can serve as effective physical crosslinking points at high temperatures, preventing the cured adhesive from softening during summer heat or when equipment heats up, thus avoiding the risk of creep or seal failure in bonded components.

[0018] Furthermore, PUA, as a "flexible continuous phase," can perfectly synergize with subsequently added reactive liquid rubber toughening agents (ATBN). The polarity of its polyether soft segments has good compatibility with the nitrile portion in ATBN, ensuring uniform dispersion of the toughening agent and generating an effective "sea-island" structure or interpenetrating network.

[0019] In summary, this invention, through the reaction of polyether polyols with isocyanates and hydroxy acrylates to obtain polyether polyurethane acrylates with a glass transition temperature (Tg) below -40°C, and the synergistic effect of other components, yields a novel UV adhesive that retains the original advantages of UV adhesives in terms of curing speed, bonding strength, optical transparency, and heat resistance, while maintaining good toughness, impact resistance, and interfacial adhesion stability at temperatures of -40°C and even lower. It can meet the demanding application environment requirements of automotive electronics, outdoor displays, and other applications with a wide temperature range (e.g., -40°C to 85°C), while maintaining good process adaptability and long-term durability.

[0020] The beneficial effects of this invention are as follows: (1) Excellent low-temperature toughness and crack resistance: This invention utilizes a dual synergistic toughening mechanism of low-Tg polyether polyurethane acrylate resin phase and reactive liquid rubber toughening agent at the molecular chain, enabling the resulting colloid to maintain good deformation capacity at -40 ℃. Tests show that the UV adhesive of this invention has an elongation at break greater than 8% at low temperature (-40 ℃), which is far superior to conventional UV adhesives (typically Tg>-20 ℃, completely brittle at -40 ℃).

[0021] (2) Excellent low-temperature bonding reliability: The silane coupling agent system used in this invention forms a strong chemical bond and physical entanglement layer at the interface between the adhesive layer and the substrate. This interface layer can effectively buffer the shrinkage stress caused by the difference in thermal expansion coefficient at low temperatures. Tests have shown that its shear strength retention rate of glass at -40 ℃ (compared to 25 ℃) can reach more than 75%, and no visible cracking or debonding phenomenon is observed after thermal cycling (-40 ℃ / 85 ℃, 200 times).

[0022] (3) Strong process adaptability: The formula has a moderate viscosity (3000-8000 mPa·s at 25 ℃) and rapid deep curing characteristics (using a 365 nm LED light source with a light intensity of 100 mW / cm², a 1 mm thick adhesive layer can be completely cured after 30s of irradiation), which is highly compatible with the high-efficiency dispensing, bonding and curing processes of modern LCD automated production lines.

[0023] (4) Excellent long-term stability: The toughening agents and silane coupling agents used are all reactive or bonded, with no risk of small molecule migration and precipitation, ensuring that the adhesive has stable performance and long service life during long-term low-temperature storage or cold and heat cycle aging. Attached Figure Description

[0024] Figure 1 This is a sample image of the UV adhesive prepared in Example 1 after 500 cycles of hot and cold.

[0025] Figure 2 The image shows a sample of the UV adhesive prepared for Comparative Example 2 after 500 cycles of hot and cold cycling. Detailed Implementation

[0026] A low-temperature resistant UV adhesive for LCDs, based on a total mass percentage of 100%, contains the following raw materials and their respective mass percentages: Polyether-type polyurethane acrylate 30-60%, 30-50% reactive diluent Low-temperature toughening agent 5-20%, Photoinitiator 1-5%, Silane coupling agent 0.5-5%, Rheology modifier 0.1-0.5%.

[0027] The active diluent is one or more of the following: isobornyl acrylate, phenoxyethyl acrylate, lauryl acrylate, hydroxyethyl acrylate, cyclotrimethylolpropane methyl acetal acrylate, tripropylene glycol diacrylate, and ethoxylated bisphenol A diacrylate.

[0028] The low-temperature toughening agent is one or more of the following: amino-terminated liquid nitrile rubber (ATBN, with a number average molecular weight of 3000-5000), carboxyl-terminated liquid polybutadiene rubber (CTPB, with a number average molecular weight of 3000-5000), lauryl acrylate, stearyl acrylate, octadecyl methacrylate, polyethylene glycol methyl ether methacrylate, and polypropylene glycol diacrylate.

[0029] The photoinitiator is one or more of α-hydroxy ketones (including 184, 1173, etc.), acylphosphine oxides (including TPO, 819), and benzoyl carboxyl esters (including MBF).

[0030] The silane coupling agent is one or more of γ-glycidoxypropyltrimethoxysilane (including KH-560, A-187, 187), methacryloyloxypropyltrimethoxysilane (including KH-570, A-174, 174), and γ-aminopropyltriethoxysilane (including KH-550, A-1100).

[0031] The rheology modifier is a hydrophobic fumed silica, including one or more of AEROSIL R 972, R 974, and R 812.

[0032] The preparation of the polyether-type polyurethane acrylate (PUA) includes the following steps: (1) Dehydration of polyether polyols The polyether polyol was added to a dry three-necked flask and dehydrated for 2 hours at 100-110°C and a vacuum of <0.1 MPa, and then cooled to 60°C for later use; the polyether polyol was polypropylene glycol or polytetrahydrofuran ether glycol (PTMEG). (2) Synthesis of prepolymer Under nitrogen protection, HDI was added to the dehydrated polyether polyol at a molar ratio of 1:2.05, along with 0.02-0.05% (by weight) of the polyether polyol catalyst DBTDL. The mixture was then heated to 75±5℃ and reacted for 2-3 hours. During this time, the NCO content was monitored by di-n-butylamine titration until it approached the theoretical value (approximately 5.2%), yielding a prepolymer with terminal NCOs (a suitable amount of acetone can be added to adjust the viscosity if it is too high). (3) End-capping reaction The prepolymer obtained in step (2) was cooled to 50°C, and HEA and 0.1% (by mass) of the polymerization inhibitor MEHQ were added at a molar ratio of 1:1.05. The reaction was continued at 50-60°C for 2-4 hours. The reaction was monitored by FTIR until the NCO reaction was complete (2270 cm⁻¹). -1 After the NCO characteristic peak disappears, heating is stopped, and the product is distilled under reduced pressure at 40-50 °C. Then, it is degassed under light-protected conditions to obtain a pale yellow to colorless and transparent viscous liquid product.

[0033] To make the content of this invention easier to understand, the technical solution of this invention will be further described below with reference to specific embodiments, but this invention is not limited thereto.

[0034] The polyether-type polyurethane acrylate used in the examples was prepared by reacting polytetrahydrofuran ether diol (PTMEG) with hexamethylene diisocyanate (HDI) and 2-hydroxyethyl acrylate (HEA) as raw materials. Taking the sample with n=37 in the structural formula as an example, its characterization data are as follows: ¹H NMR (400 MHz, CDCl3), δ: 6.40 (dd, 2H, =CH-), 6.12 (dd, 2H, =CH-), 5.82 (dd, 2H, =CH2), 5.10 (br s, 2H,-NH-), 4.30 (t, 4H, -CH2-OC(O)-), 4.16 (t,4H, -CH2-OC(O)-), 3.40 (t, 4H, -CH2-CH2-O), 3.38 (s, 216H, -O-CH2-), 3.20 (3,4H, -NH-CH2-), 1.58 (m, 216H, -CH2-), 1.35-1.40 (m, 8H, -CH2-); 13 C NMR (101 MHz, CDCl3), δ: 166.5 (s, CH2=CH-C(O)-O-), 156.0 (s, -NH-C(O)-O-), 132.0 (d, =CH-), 128.0 (t, =CH2), 70.5(m,-O-CH2-), 68.8 (t,-CH2-CH2-O-), 64.5 (t, -CH2-OC(O)-), 40.5 (t,-NH-CH2-), 30.2(t,-CH2-), 26.3(m, -CH2-CH2-), 25.8(t, -CH2-CH2-NH-). Example

[0035] UV adhesives were prepared according to the formulations in Table 1. Specifically, under light-protected conditions, polyurethane acrylate resin, low-temperature toughening agent, and 30% of the photoinitiator were added to a stirred tank and stirred for 1-2 hours at 40-60℃ and a vacuum of -0.095MPa to make the system uniform and transparent. After cooling to room temperature, the remaining photoinitiator, reactive diluent, silane coupling agent, and rheology modifier were added. After stirring for another 0.5 hours, the material was discharged, filtered, and the final product was obtained.

[0036] Table 1. Raw materials and their contents in different UV adhesive samples

[0037] The UV adhesive sample prepared above was injected into a polytetrafluoroethylene mold to form a standard dumbbell-shaped specimen (ASTM D638 Type V) or a circular disc with a diameter of 25 mm and a thickness of 1 mm. An LED point light source with a wavelength of 365 nm (light intensity 100 mW / cm²) was used. 2 The sample was then irradiated for 30 seconds to cure. The prepared sample was then subjected to the following performance tests.

[0038] ① Glass transition temperature (Tg) and embrittlement temperature (Tb): Dynamic thermomechanical analyzer (DMA), tensile mode, heating rate 3 ℃ / min, Tg was determined by the peak value of loss modulus, and the embrittlement trend was evaluated by the inflection point region of the storage modulus-temperature curve.

[0039] ② Shear strength: Using a universal testing machine, the test was conducted at 25℃ and -40℃ (after being kept at a constant temperature in an environmental chamber for 2 hours) at a rate of 10 mm / min, and the low-temperature strength retention rate was calculated.

[0040] ③ Thermal cycling test: Place the sample in a high and low temperature test chamber and perform 500 cycles, with each cycle consisting of -40℃ (holding for 30 min) → room temperature (15 min) → 85℃ (holding for 30 min) → room temperature (15 min). After each cycle, visually inspect and test the residual shear strength at 25℃.

[0041] The results are summarized in Table 2.

[0042] Table 2 Performance test results after different UV adhesive coatings

[0043] Figure 1 , 2 Images of UV adhesives prepared in Example 1 and Comparative Example 2 after 500 cycles of hot and cold cycling are shown. (Comparison) Figure 1 , 2 It can be observed that the UV adhesive prepared in Example 1 maintained an intact bonding interface after 500 rigorous thermal cycles, while the UV adhesive prepared in Comparative Example 2 showed obvious cracking at the edges after thermal cycles. Combined with the data in Table 2, it can be seen that the UV adhesive prepared using polyether-type polyurethane acrylate in this invention can maintain high shear strength (>13 MPa) and good toughness at -40℃, without brittle fracture, and retains more than 75% of its strength, ensuring chain segment mobility at low temperatures and long-term reliability.

[0044] The above description demonstrates that the UV adhesive prepared by this invention exhibits excellent overall performance, which is attributed to the flexible matrix composed of low-Tg polyether-type polyurethane acrylate, the toughening effect of ATBN, the interfacial strengthening effect of the silane coupling agent, and the synergistic effect of the reactive diluent formulation. This product effectively solves the problems of low-temperature embrittlement, interfacial failure, and performance imbalance in existing technologies, making it particularly suitable for harsh environments such as automotive displays and outdoor equipment.

[0045] The above embodiments provide a detailed description of the present invention, but they are merely examples and are not intended to limit the scope of the patent. Any equivalent modifications and substitutions made to the present invention based on this specification are also within the scope of the present invention and are included within the patent protection scope of the present invention.

Claims

1. A low-temperature UV-resistant adhesive for LCDs, characterized in that, Based on a total mass percentage of 100%, the raw materials used and the mass percentage of each raw material are as follows: Polyether-type polyurethane acrylate 30-60%, 30-50% reactive diluent Low-temperature toughening agent 5-20%, Photoinitiator 1-5%, Silane coupling agent 0.5-5%, Rheology modifier 0.1-0.5%; The UV adhesive can be used in a wide temperature range from -40°C to 85°C.

2. The low-temperature UV-resistant adhesive for LCDs according to claim 1, characterized in that, The polyether-type polyurethane acrylate is prepared from polyether-type polyols, HDI, and HEA as raw materials; its glass transition temperature is -40℃ to -50℃, and its chemical structural formula is: ， Where n is an integer between 25 and 30; The polyether-type polyol is polypropylene glycol or polytetrahydrofuran ether glycol.

3. The low-temperature UV-resistant adhesive for LCDs according to claim 2, characterized in that, The preparation of the polyether-type polyurethane acrylate includes the following steps: (1) Synthesis of prepolymer Under nitrogen protection, HDI and catalyst DBTDL were added to the dehydrated polyether polyol, and then the temperature was raised to 75±5℃ and the reaction was carried out for 2-3 hours to obtain a prepolymer with terminal NCO. (2) End-capping reaction The prepolymer obtained in step (1) was cooled to 50°C, HEA and polymerization inhibitor MEHQ were added, and the reaction was continued at 50-60°C for 2-4 hours until the NCO terminal reaction was complete. Heating was then stopped, and the product was degassed under reduced pressure at 40-50°C and defoamed under light-protected conditions to obtain a pale yellow to colorless transparent viscous liquid product.

4. The low-temperature UV-resistant adhesive for LCDs according to claim 3, characterized in that, In step (1), the molar ratio of polyether polyol to HDI is 1:2.05, and the amount of DBTDL used is 0.02~0.05% of the mass of the polyether polyol used; In step (2), the molar ratio of HEA to NCO in the prepolymer is 1.05:1, and the amount of MEHQ used is 0.1% of the mass of the prepolymer.

5. The low-temperature UV-resistant adhesive for LCDs according to claim 1, characterized in that, The active diluent is one or more of the following: isobornyl acrylate, phenoxyethyl acrylate, lauryl acrylate, hydroxyethyl acrylate, cyclotrimethylolpropane methyl acetal acrylate, tripropylene glycol diacrylate, and ethoxylated bisphenol A diacrylate.

6. The low-temperature UV-resistant adhesive for LCDs according to claim 1, characterized in that, The low-temperature toughening agent is one or more of the following: amino-terminated liquid nitrile rubber, carboxyl-terminated liquid polybutadiene rubber, lauryl acrylate, stearyl acrylate, octadecyl methacrylate, polyethylene glycol methyl ether methacrylate, and polypropylene glycol diacrylate.

7. The low-temperature UV-resistant adhesive for LCDs according to claim 1, characterized in that, The photoinitiator is one or more of α-hydroxy ketones, acylphosphine oxides, and benzoyl carbamates.

8. The low-temperature UV-resistant adhesive for LCDs according to claim 1, characterized in that, The silane coupling agent is one or more of γ-glycidoxypropyltrimethoxysilane, methacryloyloxypropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

9. The low-temperature UV-resistant adhesive for LCDs according to claim 1, characterized in that, The rheology modifier is hydrophobic fumed silica.

10. The low-temperature UV-resistant adhesive for LCDs according to claim 1, characterized in that, The UV adhesive is prepared by mixing polyether-type polyurethane acrylate resin, low-temperature toughening agent, and 30% photoinitiator under light-protected conditions at 40-60°C and a vacuum of -0.095MPa for 1-2 hours to make the system uniform and transparent. After cooling to room temperature, the remaining photoinitiator, reactive diluent, silane coupling agent, and rheology modifier are added, and the mixture is stirred for another 0.5 hours before being discharged.

Images