Inorganic nanoparticle composite modified UV-curable acrylic pressure-sensitive adhesive and preparation method thereof

Abstract

The application discloses an inorganic nanoparticle composite modified UV curing acrylic pressure-sensitive adhesive and a preparation method thereof, and solves the problems of uneven dispersion of hollow MgF2 nanoparticles and difficulty in giving consideration to multiple performances of the pressure-sensitive adhesive. The method comprises the following steps: activating hollow MgF2 by hydrochloric acid to expose hydroxyl groups; preparing a modifier containing hydroxyl groups and side chains, and grafting the modifier on the surface of the activated particles through a condensation reaction; mixing and dispersing the modified particles, UV curing acrylic resin and a solvent, adding a photo initiator to obtain a prepolymer; coating the prepolymer into a 300-350 nm coating layer, and performing UV curing to obtain the pressure-sensitive adhesive. The application realizes uniform dispersion of the particles through "hydrochloric acid activation-polymer grafting", and the thickness of the coating layer is designed, so that the prepared pressure-sensitive adhesive has high transparency, excellent wear resistance, high temperature resistance and good adhesion, and is suitable for high-end optical devices, precision electronics and other fields.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure sensitive adhesive, in particular to an inorganic nano-particle composite modified UV-curable acrylic pressure sensitive adhesive and a preparation method thereof. BACKGROUND

[0002] The UV-curable acrylic pressure sensitive adhesive is widely used in packaging, electronics, optics and other fields due to its fast curing speed, no solvent emission and low energy consumption. However, the traditional UV-curable acrylic pressure sensitive adhesive has problems such as insufficient transparency, poor wear resistance and poor high temperature resistance, which limits its application in high-end optical devices, precision electronics and other fields with high performance requirements.

[0003] The refractive index of MgF2 is relatively low (about 1.38), and the refractive index of hollow MgF2 nanoparticles can be further reduced. By introducing hollow MgF2 nanoparticles into the pressure sensitive adhesive, it is expected to reduce the reflection and scattering of light and improve the light transmittance. At the same time, the addition of inorganic nano-particles can also enhance the mechanical properties and high temperature resistance of the pressure sensitive adhesive.

[0004] However, the surface of hollow MgF2 nanoparticles has strong polarity, and the compatibility with the organic UV-curable acrylic resin matrix is poor, which is easy to agglomerate and difficult to disperse uniformly. Not only can it not play its modification effect, but also it may cause the performance of the pressure sensitive adhesive to decline. In addition, the thickness of the pressure sensitive adhesive coating has a significant impact on its adhesion and light transmittance, and it is difficult to find a coating thickness range that takes into account good adhesion and high light transmittance in the prior art. Therefore, how to realize the uniform dispersion of hollow MgF2 nanoparticles in the pressure sensitive adhesive matrix, and combined with the design of appropriate coating thickness, to prepare a UV-curable acrylic pressure sensitive adhesive with high transparency, excellent wear resistance, high temperature resistance and good adhesion, has become a problem to be solved at present. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and provide an inorganic nano-particle composite modified UV-curable acrylic pressure sensitive adhesive and a preparation method thereof, to solve the problems of uneven dispersion of hollow MgF2 nanoparticles in the pressure sensitive adhesive, and the difficulty of the pressure sensitive adhesive to balance transparency, wear resistance, high temperature resistance and adhesion.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0007] A preparation method of an inorganic nano-particle composite modified UV-curable acrylic pressure sensitive adhesive, comprising the following steps:

[0008] S1, activation of hollow MgF2 nanoparticles: hollow MgF2 nanoparticles are added to a hydrochloric acid solution with a concentration of 0.5-2 mol / L for soaking, and then washed to neutral to obtain activated hollow MgF2 nanoparticles;

[0009] S2, Preparation of the modifier: 70-80 parts by mass of butyl acrylate, 20-30 parts by mass of hydroxyethyl acrylate, 0.7-0.9 parts by mass of azobisisobutyronitrile are added into 250-350 parts by mass of tetrahydrofuran, after oxygen removal by nitrogen blowing, 65-75℃ reaction for 5-7h; 40-60 parts by mass of methyl methacrylate and 0.4-0.6 parts by mass of azobisisobutyronitrile are added, 70-80℃ reaction for 4-6h; the reaction solution is poured into petroleum ether to precipitate, filtered, washed, and the modifier is obtained;

[0010] S3, Modified hollow MgF2 nanoparticles: 3-5 parts by mass of activated hollow MgF2 nanoparticles are added into 8-12 parts by mass of ethyl acetate, ultrasonic dispersion to form a suspension; 0.8-1.2 parts by mass of the modifier prepared in step S2 and p-toluenesulfonic acid (1%-3% of the weight of the grafted polymer) are added, nitrogen protection, 70-90℃ stirring reaction for 4-8h; centrifugation, washing, and the modified hollow MgF2 nanoparticles are obtained;

[0011] S4, Preparation of pressure-sensitive adhesive: 50-80 parts by mass of UV-curable acrylic resin, 5-15 parts by mass of modified hollow MgF2 nanoparticles, and 10-30 parts by mass of solvent are added, 1000-2000r / min high-speed stirring dispersion for 30-60min; 2-4 parts by mass of photoinitiator is added, 500-800r / min stirring for 15-30min, and the prepolymer mixture is obtained;

[0012] S5, Formation of pressure-sensitive adhesive coating: coated on the surface of the substrate, the coating thickness is controlled to be 300-350nm; UV light irradiation curing for 30-60s, and the target pressure-sensitive adhesive coating is obtained.

[0013] Activation mechanism: In step S1, 0.5-2mol / L hydrochloric acid solution can remove impurities and residual salt on the surface of hollow MgF2 nanoparticles, and at the same time, through mild etching, it can destroy part of the Mg-F bond on the surface of the particles, so that more hydroxyl groups (-OH) are exposed on the surface, forming activated particles rich in active sites, providing a chemical basis for subsequent grafting of the modifier.

[0014] The hydroxyl group-containing hydroxyethyl acrylate unit in the main chain of the modifier prepared in step S2 can condense with the hydroxyl group on the surface of the activated MgF2 under the catalysis of p-toluenesulfonic acid, forming a stable -O- covalent bond, so that the modifier is firmly grafted onto the surface of the particles; the side chain of polymethyl methacrylate (PMMA) is similar in structure to the hard monomer (such as methyl methacrylate) in the UV-curable acrylic resin, according to the principle of "like dissolves like", the interfacial tension between the inorganic particles and the organic resin matrix is greatly reduced, avoiding particle agglomeration and achieving uniform dispersion.

[0015] High transparency: the uniformly dispersed hollow MgF2 nanoparticles have low refractive index (lower than the resin matrix), which can reduce the reflection and scattering of light at the resin-particle interface; at the same time, the coating thickness of 300-350 nm is designed according to the Fresnel law, which is the minimum reflection loss of light on the surface of the coating, and avoids the decrease of light transmittance caused by multiple reflection of light in thick coating, and the double effects can significantly improve the visible light transmittance of the pressure sensitive adhesive.

[0016] Wear resistance and high temperature resistance: the inorganic hollow MgF2 nanoparticles have a rigid structure, and after uniform dispersion, they can act as a physical reinforcing phase to form a "rigid support network" in the pressure sensitive adhesive matrix, reducing the deformation and wear of the coating under external force; at the same time, the thermal stability of inorganic particles is better than that of organic resin, which can inhibit the thermal motion of resin molecular chains at high temperature, and improve the high temperature resistance of the pressure sensitive adhesive.

[0017] As a further preferred preparation method of inorganic nanoparticle composite modified UV cured acrylic pressure sensitive adhesive.

[0018] Preferably, the size of the hollow MgF2 nanoparticles is less than 100 nm.

[0019] Too large size or scattering of incident light, thereby reducing the light transmittance.

[0020] Preferably, the UV cured acrylic resin in step S4 is a copolymer of soft monomer, hard monomer and functional monomer, and the weight ratio of soft monomer: hard monomer: functional monomer is 60-80: 20-30: 5-10. The soft monomer provides viscosity and flexibility, and is selected from at least one of butyl acrylate and isooctyl acrylate; the hard monomer improves the cohesion and mechanical strength, and is selected from at least one of methyl methacrylate and styrene; the functional monomer introduces active groups and enhances the bonding force, and is selected from at least one of hydroxyethyl acrylate and acrylic acid.

[0021] Preferably, the photoinitiator in step S4 is 1-hydroxycyclohexyl phenyl ketone.

[0022] Preferably, the solvent in step S4 is ethyl acetate.

[0023] Preferably, in step S5, the substrate is a PET film.

[0024] The inorganic nanoparticle composite modified UV cured acrylic pressure sensitive adhesive prepared according to the above preparation method.

[0025] The beneficial effects of the present application compared with the prior art are:

[0026] (1) Solve the dispersion problem of hollow MgF2 nanoparticles, lay the foundation for performance improvement. Through the two-step modification strategy of "hydrochloric acid activation-polymer grafting", the compatibility of inorganic nanoparticles and organic resin is fundamentally improved. Hydrochloric acid activation can remove impurities on the particle surface and expose hydroxyl active sites, providing a chemical basis for subsequent grafting; self-made modifier greatly reduces the interfacial tension through hydroxyl condensation reaction, completely avoids particle agglomeration, realizes the uniform dispersion of hollow MgF2 in resin, and ensures that the modification effect is fully played.

[0027] (2) Achieve the synergistic consideration of high transparency and good adhesion. The present application breaks the balance problem of traditional pressure sensitive adhesive transparency and adhesion through "dispersion optimization + thickness design" double regulation: uniformly dispersed low refractive index hollow MgF2 nanoparticles can reduce the reflection and scattering of light at the resin-particle interface; the coating thickness of 300-350 nm is designed according to the Fresnel law, which can avoid insufficient adhesion of thin coating and prevent the decrease of light transmittance caused by multiple reflections in thick coating, so that the visible light transmittance of pressure sensitive adhesive is significantly improved, while the stable adhesion performance is maintained.

[0028] (3) Significantly enhance wear resistance and high temperature resistance. The synergistic effect of inorganic nanoparticles and organic matrix greatly improves the mechanical and thermal stability of pressure sensitive adhesive: uniformly dispersed hollow MgF2 nanoparticles as "rigid support phase" can effectively resist coating deformation and wear under external force; the high heat resistance of inorganic particles can inhibit the thermal motion of resin molecular chains at high temperature, thereby improving the high temperature resistance of pressure sensitive adhesive. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a scanning electron microscope photo of the pressure sensitive adhesive prepared in Example 1 applied on the substrate;

[0030] Figure 2 (a)-(b) are transmission electron microscope photos of hollow MgF2 nanoparticles and modified Example 1, respectively;

[0031] Figure 3 (a) and (b) are the scratches of 3H pencil on the coating observed under optical microscope of the coating of Example 1 and Comparative Example 2, respectively;

[0032] Figure 4 is a column chart of the peel force of the pressure sensitive adhesive prepared in Examples 1-3 and Comparative Examples 2-5 before and after 2h at 180℃;

[0033] Figure 5 is the transmittance curve of Example 1, Comparative Example 2 and PET substrate;

[0034] Figure 6 is the transmittance curve of Example 1, Example 4, Comparative Example 4 and Comparative Example 5. Detailed Implementation

[0035] To make the above-mentioned objectives, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to examples. The following content is merely illustrative and explanatory of the concept of the present invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the concept of the invention, they should all fall within the protection scope of the present invention.

[0036] The preparation method of the present invention will be described below through specific embodiments and comparative examples.

[0037] Example 1

[0038] A method for preparing an inorganic nanoparticle composite modified UV-curable acrylic pressure-sensitive adhesive includes the following steps:

[0039] S1. Activation of hollow MgF2 nanoparticles: Hollow MgF2 nanoparticles were soaked in a 0.5 mol / L hydrochloric acid solution and then washed until neutral to obtain activated hollow MgF2 nanoparticles.

[0040] S2. Preparation of the modifier: 75 parts by mass of butyl acrylate, 25 parts by mass of hydroxyethyl acrylate, and 0.8 parts by mass of azobisisobutyronitrile were added to 300 parts by mass of tetrahydrofuran. After purging with nitrogen to remove oxygen, the mixture was reacted at 70°C for 6 hours. Then, 50 parts by mass of methyl methacrylate and 0.5 parts by mass of azobisisobutyronitrile were added, and the mixture was reacted at 75°C for 5 hours. The reaction solution was poured into petroleum ether to precipitate, filtered, and washed to obtain the modifier.

[0041] S3, Modified hollow MgF2 nanoparticles: 4 parts by mass of activated hollow MgF2 nanoparticles were added to 10 parts by mass of ethyl acetate and ultrasonically dispersed to form a suspension; then 1 part by mass of the modifier prepared in step S2 and p-toluenesulfonic acid (1% of the weight of the grafted polymer) were added, and the mixture was stirred at 70°C for 4 hours under nitrogen protection; after centrifugation and washing, modified hollow MgF2 nanoparticles were obtained.

[0042] S4. Preparation of pressure-sensitive adhesive: Add 50 parts by weight of UV-curable acrylic resin, 5 parts by weight of modified hollow MgF2 nanoparticles, and 10 parts by weight of solvent, and disperse by high-speed stirring at 1000 r / min for 30 min; add 2 parts by weight of photoinitiator, and stir at 500 r / min for 15 min to obtain a prepolymer mixture.

[0043] S5. Forming of pressure-sensitive adhesive coating: Apply to the surface of the substrate, control the coating thickness to 300nm; cure by UV light for 30s to obtain the target pressure-sensitive adhesive coating.

[0044] The UV-cured acrylic resin in step S4 is a copolymer of soft monomers, hard monomers and functional monomers, and the weight ratio of soft monomers:hard monomers:functional monomers is 60:20:5. The soft monomers are butyl acrylate; the hard monomers are methyl methacrylate; and the functional monomers are hydroxyethyl acrylate. The photoinitiator in step S4 is 1-hydroxycyclohexyl phenyl ketone; and the solvent in step S4 is ethyl acetate. In step S5, the substrate is a PET film.

[0045] Example 2

[0046] A preparation method of an inorganic nanoparticle composite modified UV-cured acrylic pressure-sensitive adhesive comprises the following steps:

[0047] S1, activation of hollow MgF2 nanoparticles: hollow MgF2 nanoparticles are soaked in a 1 mol / L hydrochloric acid solution, then washed to neutral to obtain activated hollow MgF2 nanoparticles;

[0048] S2, preparation of a modifier: 70 parts by mass of butyl acrylate, 20 parts by mass of hydroxyethyl acrylate, and 0.7 parts by mass of azobisisobutyronitrile are added to 250 parts by mass of tetrahydrofuran, and after oxygen removal by nitrogen blowing, the mixture is reacted at 65°C for 5 hours; 40 parts by mass of methyl methacrylate and 0.4 parts by mass of azobisisobutyronitrile are added, and the mixture is reacted at 70°C for 4 hours; the reaction solution is precipitated in petroleum ether, filtered, and washed to obtain the modifier;

[0049] S3, modified hollow MgF2 nanoparticles: 3 parts by mass of activated hollow MgF2 nanoparticles are added to 8 parts by mass of ethyl acetate to form a suspension by ultrasonic dispersion; 0.8 parts by mass of the modifier prepared in step S2 and p-toluenesulfonic acid (an amount of 2% of the weight of the grafted polymer) are added, and the mixture is stirred and reacted at 80°C for 6 hours under nitrogen protection; the mixture is centrifuged and washed to obtain the modified hollow MgF2 nanoparticles;

[0050] S4, preparation of a pressure-sensitive adhesive: 65 parts by mass of a UV-cured acrylic resin, 10 parts by mass of modified hollow MgF2 nanoparticles, and 20 parts by mass of a solvent are added, and the mixture is dispersed at a high speed of 1500 r / min for 45 minutes; 3 parts by mass of a photoinitiator is added, and the mixture is stirred at a speed of 650 r / min for 20 minutes to obtain a prepolymer mixture;

[0051] S5, forming of a pressure-sensitive adhesive coating: the coating is applied to the surface of a substrate, and the thickness of the coating is controlled to be 320 nm; the coating is cured by UV irradiation for 45 seconds to obtain a target pressure-sensitive adhesive coating.

[0052] The UV-cured acrylic resin in step S4 is a copolymer of soft monomers, hard monomers and functional monomers, and the weight ratio of soft monomers:hard monomers:functional monomers is 70:25:8. The soft monomers are isooctyl acrylate; the hard monomers are styrene; and the functional monomers are acrylic acid. The photoinitiator in step S4 is 1-hydroxycyclohexyl phenyl ketone; the solvent in step S4 is ethyl acetate; and the substrate in step S5 is a PET film.

[0053] Example 3

[0054] A preparation method of an inorganic nanoparticle composite modified UV-cured acrylic pressure-sensitive adhesive comprises the following steps:

[0055] S1, activation of hollow MgF2 nanoparticles: hollow MgF2 nanoparticles are soaked in a 2 mol / L hydrochloric acid solution, then washed to neutral to obtain activated hollow MgF2 nanoparticles;

[0056] S2, preparation of a modifier: 80 parts by mass of butyl acrylate, 30 parts by mass of hydroxyethyl acrylate and 0.9 parts by mass of azobisisobutyronitrile are added to 350 parts by mass of tetrahydrofuran, and after oxygen removal by nitrogen blowing, 75°C reaction is carried out for 7 hours; 60 parts by mass of methyl methacrylate and 0.6 parts by mass of azobisisobutyronitrile are added, and 80°C reaction is carried out for 6 hours; the reaction solution is precipitated in petroleum ether, filtered and washed to obtain the modifier;

[0057] S3, modified hollow MgF2 nanoparticles: 5 parts by mass of activated hollow MgF2 nanoparticles are added to 12 parts by mass of ethyl acetate to form a suspension by ultrasonic dispersion; 1.2 parts by mass of the modifier prepared in step S2 and p-toluenesulfonic acid (an amount of 3% of the weight of the grafted polymer) are added, and 90°C stirring reaction is carried out for 8 hours under nitrogen protection; centrifugation and washing are carried out to obtain the modified hollow MgF2 nanoparticles;

[0058] S4, preparation of a pressure-sensitive adhesive: 80 parts by mass of a UV-cured acrylic resin, 15 parts by mass of modified hollow MgF2 nanoparticles and 30 parts by mass of a solvent are added, and 2000 r / min high-speed stirring dispersion is carried out for 60 minutes; 4 parts by mass of a photoinitiator is added, and 800 r / min stirring is carried out for 30 minutes to obtain a prepolymer mixture;

[0059] S5, forming of a pressure-sensitive adhesive coating: coating is carried out on the surface of a substrate, and the coating thickness is controlled to be 350 nm; UV light irradiation curing is carried out for 60 seconds to obtain a target pressure-sensitive adhesive coating.

[0060] In step S4, the UV-curable acrylic resin is a copolymer of soft monomers, hard monomers, and functional monomers, with a weight ratio of soft monomers:hard monomers:functional monomers = 80:30:10. The soft monomer is butyl acrylate; the hard monomer is methyl methacrylate; and the functional monomer is hydroxyethyl acrylate. The photoinitiator in step S4 is 1-hydroxycyclohexylphenyl ketone; the solvent in step S4 is ethyl acetate; and in step S5, the substrate is a PET film.

[0061] Example 4

[0062] The difference between this embodiment and Embodiment 1 is that the coating thickness in step S5 is 350 nm, while the remaining steps and parameters are the same as in Embodiment 1.

[0063] Comparative Example 1

[0064] In the preparation of the pressure-sensitive adhesive, steps S1 (activation) and S3 (modification) are omitted. Four parts by weight of untreated 80nm hollow MgF2 nanoparticles are directly added to the pressure-sensitive adhesive preparation system. The remaining steps (except for the preparation of the modifier, which is not required) and parameters are the same as in Example 1.

[0065] Comparative Example 2

[0066] No hollow MgF2 nanoparticles were added during the preparation of the pressure-sensitive adhesive, and the remaining steps and parameters were the same as in Example 1.

[0067] Comparative Example 3

[0068] The coating thickness was adjusted to 150 nm during the preparation of the pressure-sensitive adhesive, and the remaining steps and parameters were the same as in Example 1.

[0069] Comparative Example 4

[0070] The coating thickness was adjusted to 250 nm during the preparation of the pressure-sensitive adhesive, and the remaining steps and parameters were the same as in Example 1.

[0071] Comparative Example 5

[0072] The coating thickness was adjusted to 400 nm during the preparation of the pressure-sensitive adhesive, and the remaining steps and parameters were the same as in Example 1.

[0073] The pressure-sensitive adhesive prepared in Example 1 was transparent and free of turbidity; the pressure-sensitive adhesive prepared in Comparative Example 1 was milky white and turbid. This is because the particles in Example 1 were uniformly dispersed without agglomeration or precipitation, while the unmodified particles in Comparative Example 1 agglomerated, resulting in a size far exceeding the wavelength of visible light, causing severe light scattering, leading to a sharp drop in transmittance, and the pressure-sensitive adhesive appeared milky white and turbid.

[0074] Figure 1is the scanning electron microscope (SEM) photo of the pressure sensitive adhesive coating of Example 1; no obvious particle agglomeration can be seen in the coating, and the hollow MgF2 nanoparticles are uniformly distributed at the nanoscale size. This illustrates the effectiveness of the "hydrochloric acid activation-polymer grafting" modification strategy. The modifier is grafted on the particle surface through covalent bond, reduces the interfacial tension, and realizes uniform dispersion, laying a foundation for subsequent performance improvement.

[0075] Fig. is the transmission electron microscope (TEM) photo of 2(a) unmodified hollow MgF2 nanoparticles and 2(b) modified hollow MgF2 nanoparticles of Example 1; Figure 2 (a) in which no wrapping is seen on the surface of the unmodified particles, and the particle size is 20-60 nm, with clear edges; Figure 2 (b) in which the surface of the modified particles is wrapped with a uniform polymer film (modifier layer), and the particle size is slightly larger than that of the unmodified particles. This directly proves that the modifier is successfully grafted on the particle surface. Hydrochloric acid activation exposes hydroxyl groups on the particle surface, which condense with the hydroxyl groups in the modifier to form stable covalent bonds, completing the organic modification of inorganic particles and solving the compatibility problem.

[0076] Fig. is the scratch of 3(a) and 3(b) on the coating of 3H pencil hardness under optical microscope, respectively, of the coating of Example 1 and Comparative Example 2; the scratch of the coating of Example 1 is shallow and narrow; the scratch of Comparative Example 2 (without nanoparticles) is deep and wide. The hollow MgF2 nanoparticles form a "rigid support network" in the matrix, enhancing the mechanical strength of the coating and reducing deformation and wear under external force.

[0077] Figure 4 is the peel force column chart of the pressure sensitive adhesive of Example 1-3 and Comparative Example 2-5 before and after 180℃ / 2h; comparing Example 1-3 with Comparative Example 2, it can be seen that the peel force of Example 1-3 is less weakened after high temperature treatment, while that of Comparative Example 2 is greatly reduced. This is because the high heat resistance of inorganic particles inhibits the high temperature thermal motion of resin molecular chains, improving the thermal stability.

[0078] In addition, the adhesion of the coating with a thickness of 300-350 nm is close to that without adding particles, which illustrates that the coating has both adhesion and heat resistance. The adhesion area of the thin coating (150 nm) is insufficient, and its peel force is small.

[0079] Figure 5 : The transmittance curve of Example 1, Comparative Example 2 and PET substrate; it can be seen that the transmittance of Example 1 is obviously higher than that of Comparative Example 2 and PET substrate, which is because the refractive index of hollow MgF2 particles is small, which can reduce the overall refractive index of the coating, thereby improving the light transmittance of the coating. In addition, the thickness of the coating meets the Fresnel reflection law, which can cancel out the interference of light, reduce the reflected light, and increase the transmittance.

[0080] Figure 6: Example 1, Example 4, Comparative Example 4, Comparative Example 5 transmittance curve; it can be seen that the light transmittance of Example 1, Example 4 is higher than that of Comparative Example 4, Comparative Example 5. This shows that the thickness of the coating needs to meet a certain waveband range, so as to have higher light transmittance. The results show that when the coating thickness is 300-350 nm, the transmittance is higher.

[0081] In addition, when the coating thickness is low, 150 nm (Comparative Example 3), it also has higher light transmittance, but its adhesion is poor. In order to have both light transmittance and adhesion, the coating thickness is selected to be 300-350 nm.

Claims

1. A method for preparing an inorganic nanoparticle composite modified UV-curable acrylic pressure-sensitive adhesive, characterized in that, Includes the following steps: S1. Activation of hollow MgF2 nanoparticles: Hollow MgF2 nanoparticles are soaked in hydrochloric acid solution to obtain activated hollow MgF2 nanoparticles. S2. Preparation of the modifier: 70-80 parts by weight of butyl acrylate, 20-30 parts by weight of hydroxyethyl acrylate, and 0.7-0.9 parts by weight of azobisisobutyronitrile are added to 250-350 parts by weight of tetrahydrofuran, and nitrogen gas is introduced. The mixture is reacted at 65-75℃ for 5-7 hours. Then, 40-60 parts by weight of methyl methacrylate and 0.4-0.6 parts by weight of azobisisobutyronitrile are added, and the mixture is reacted at 70-80℃ for 4-6 hours. After purification, the modifier is obtained. S3, Modified hollow MgF2 nanoparticles: 3-5 parts by weight of activated hollow MgF2 nanoparticles are added to 8-12 parts by weight of ethyl acetate and ultrasonically dispersed; then 0.8-1.2 parts by weight of the modifier prepared in step S2 and p-toluenesulfonic acid are added, wherein the amount of p-toluenesulfonic acid is 1%-3% of the weight of the modifier, and the mixture is stirred at 70-90℃ for 4-8 hours under nitrogen protection. Centrifugation and washing yielded modified hollow MgF2 nanoparticles. S4. Preparation of pressure-sensitive adhesive: Add 50-80 parts by weight of UV-curable acrylic resin, 5-15 parts by weight of modified hollow MgF2 nanoparticles, and 10-30 parts by weight of solvent, and stir for 30-60 min; add 2-4 parts by weight of photoinitiator, and stir for 15-30 min to obtain a prepolymer mixture. S5. Forming of pressure-sensitive adhesive coating: The prepolymer mixture is coated on the surface of the substrate, and the coating thickness is controlled to be 300-350nm; after curing by UV light for 30-60s, the target pressure-sensitive adhesive coating is obtained.

2. The preparation method according to claim 1, characterized in that, The size of the hollow MgF2 nanoparticles described in step S1 is less than 100 nm.

3. The preparation method according to claim 1, characterized in that, The UV-curable acrylic resin in step S4 is a copolymer of soft monomers, hard monomers and functional monomers, with a weight ratio of soft monomers:hard monomers:functional monomers = 60-80:20-30:5-10; the soft monomers are selected from at least one of butyl acrylate and isooctyl acrylate; the hard monomers are selected from at least one of methyl methacrylate and styrene; and the functional monomers are selected from at least one of hydroxyethyl acrylate and acrylic acid.

4. The preparation method according to claim 1, characterized in that, The photoinitiator mentioned in step S4 is 1-hydroxycyclohexylphenyl ketone.

5. The preparation method according to claim 1, characterized in that, The solvent used in step S4 is ethyl acetate.

6. The preparation method according to claim 1, characterized in that, In step S5, the substrate is a PET film.

7. An inorganic nanoparticle composite modified UV-curable acrylic pressure-sensitive adhesive prepared by any one of the preparation methods described in claims 1-6.

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