Optical-grade high-resilience acrylic pressure-sensitive adhesive as well as preparation method and application thereof

Abstract

The invention discloses an optical-grade high-resilience acrylic pressure-sensitive adhesive as well as a preparation method and application thereof. The optical-grade high-resilience acrylic pressure-sensitive adhesive is prepared from the following raw materials: an acrylic monomer, a cross-linking agent, an initiator, an antioxidant and a solvent. The acrylic monomer comprises a soft monomer and a hard monomer, the soft monomer comprises a carbon-carbon double bond, the soft monomer comprises 2-ethylhexyl acrylate and 2-ethylhexyl acrylate, and the molar ratio of the 2-ethylhexyl acrylate to the 2-ethylhexyl acrylate is (50-60): (20-30). According to the present invention, the preparation raw materials of the acrylate pressure-sensitive adhesive are designed, and through the cooperation of the components, the prepared acrylate pressure-sensitive adhesive has characteristics of good optical property, good peel strength and high resilience, and is suitable for the explosion-proof field of electronics, buildings and automobile glass.

Description

Technical Field

[0001] This invention relates to the field of adhesives, specifically to an optical-grade high-resilience acrylic pressure-sensitive adhesive, its preparation method, and its application. Background Technology

[0002] Acrylic pressure-sensitive adhesives have a wide range of applications, playing a crucial role in protective films for electronic products, automotive explosion-proof films, and glass exterior wall explosion-proof films. During the production of explosion-proof films, tension traction is required, which exerts downward pressure on the inside of the roll. Due to the thickness difference of the film at its initial position, transverse imprints are formed on the cross-section under pressure, causing deformation of the pressure-sensitive adhesive layer. Over time, these imprints become more severe, resulting in more defective products. Current pressure-sensitive adhesives possess high peel strength and initial tack, but their tensile strength and elongation at break are mismatched, leading to low resilience. This causes deformation of the adhesive layer, which cannot return to its original shape after the external force is removed, resulting in significant resource waste and delivery delays. Therefore, developing a pressure-sensitive adhesive with high resilience, well-matched mechanical properties, and high light transmittance is crucial.

[0003] Chinese invention patent CN116515428B discloses an acrylic pressure-sensitive adhesive and its preparation method. By introducing hydroxyl-terminated acrylate diols, it forms comb-like macromolecules during crosslinking with a curing agent, ensuring polymer flexibility while meeting cohesive requirements, but lacking light transmittance. Chinese invention patent application CN107057612A discloses a high-transmittance acrylic pressure-sensitive adhesive and its preparation method. It exhibits high transmittance (≥93%), no residue under normal use, strong adhesion, high peel strength, and no delamination, adhesive layer, or interface damage during use; however, its aging resistance is poor. Summary of the Invention

[0004] To develop a pressure-sensitive adhesive with high resilience, matching mechanical properties, and high light transmittance, the first aspect of this invention provides an optical-grade high-resilience acrylic pressure-sensitive adhesive, the raw materials of which include acrylic monomers, crosslinking agents, initiators, antioxidants, and solvents; the acrylic monomers include soft monomers and hard monomers, the soft monomers include carbon-carbon double bonds, the soft monomers include isooctyl acrylate and 2-ethylhexyl acrylate, and the molar ratio of isooctyl acrylate to 2-ethylhexyl acrylate is (50-60):(20-30).

[0005] In existing technologies, explosion-proof films made with pressure-sensitive adhesives require tension during production, which creates downward pressure on the roll material. The thickness difference between the top and bottom layers of the pressure-sensitive adhesive results in transverse indentations on the cross-section under pressure, causing deformation of the adhesive layer. These indentations worsen over time, increasing the defect rate of the pressure-sensitive adhesive film. This application uses isooctyl acrylate and 2-ethylhexyl acrylate as the main skeleton, employing a molar ratio of (50-60):(20-30). This achieves a balance between tensile strength and elongation at break, ensuring good resilience of the pressure-sensitive adhesive after stretching. The indentations recover after the external pressure is removed, preventing the generation of defective products.

[0006] This invention grafts different short chains onto the main molecular chain to form a multi-layered network structure, increasing the molecular weight and storage modulus of the adhesive layer. The resin gradually transforms from the rheological behavior of a viscoelastic liquid to that of a viscoelastic solid, enhancing the molecular chain entanglement. Under external force, the chain segments can more stably transmit stress and return to their original position, thus improving elasticity and resilience, thereby solving the indentation problem.

[0007] In one embodiment, the raw materials prepared by molar amount include 80-120 parts of acrylic acid monomer, 0.1-0.5 parts of crosslinking agent, 0.1-0.3 parts of initiator, 0.01-0.05 parts of antioxidant, and 100-160 parts of solvent.

[0008] In one embodiment, the molar ratio of the soft monomer to the hard monomer is (70-90):(10-30).

[0009] In one embodiment, the hard monomer includes at least one of methyl methacrylate, methyl acrylate, isobornyl methacrylate, hydroxyethyl methacrylate, and N,N-diethylacrylamide.

[0010] In one embodiment, the molar ratio of methyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate and N,N-diethylacrylamide is (5-10):(5-10):(2-6):(1-3).

[0011] In one embodiment, the crosslinking agent includes at least one of diethylene glycol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate, or urethane dimethacrylate.

[0012] In one embodiment, the crosslinking agent is diethylene glycol dimethacrylate.

[0013] In one embodiment, the crosslinking agent accounts for 0.10-0.3% of the molar proportion in the raw materials for preparing optical-grade high-resilience acrylic pressure-sensitive adhesive.

[0014] In one embodiment, the initiator is azobisisobutyronitrile (AIBN).

[0015] In one embodiment, the solvent includes at least one of toluene, ethyl acetate, or propylene glycol methyl acetate.

[0016] The azobisisobutyronitrile of this invention decomposes upon heating, generating free radicals and releasing nitrogen gas. The generated 2-cyano-2-propyl free radical acts as a primary free radical, attacking the double bonds of monomers and initiating polymerization. The primary free radical adds to isooctyl acrylate to form a new carbon-centered free radical, which initiates chain initiation. The new carbon-centered free radical continues to randomly add to other monomers, forming random copolymer chains for chain growth. Due to the different reactivity ratios between monomers, the actual sequence distribution is random copolymerization, and the sum constitutes the polymer backbone. In the later stages of polymerization, the two growing chain free radicals meet, resulting in coupling termination or disproportionation termination, achieving free radical solution copolymerization. The product of this invention is a random copolymer of acrylic acid.

[0017] This invention forms a multi-layered network structure by branching the main molecular chain with different short links, thereby increasing the molecular weight and storage modulus of the adhesive layer. The resin gradually transforms from the rheological behavior of a viscoelastic liquid to that of a viscoelastic solid. The molecular chain entanglement is enhanced, and the chain segments can more stably transmit stress and return to their original position after being subjected to external force. The elasticity and resilience are improved accordingly, thus solving the indentation problem.

[0018] A second aspect of the present invention provides a method for preparing an optical-grade high-resilience acrylic pressure-sensitive adhesive, comprising the following steps: S1 involves mixing 60-80 mol% of acrylic monomer with a solvent, then adding 60-80 mol% of initiator dropwise while stirring, and heating to carry out a prepolymerization reaction to form a prepolymer. S2 adds the remaining 20-40 mol% of acrylic monomer to the prepolymer, and simultaneously adds the remaining 20-40 mol% of initiator and crosslinking agent. The reaction is then continued by heating to obtain the pressure-sensitive adhesive precursor. After S3 is cooled, an antioxidant is added to the pressure-sensitive adhesive precursor, and the mixture is stirred to obtain an optical-grade high-resilience acrylic pressure-sensitive adhesive.

[0019] In one embodiment, S1 specifically involves mixing 70 mol% of acrylic monomer with a solvent, then adding 70 mol% of initiator dropwise while stirring, heating to carry out a prepolymerization reaction, and maintaining the temperature for 1-3 hours to form a prepolymer.

[0020] In one embodiment, the heating temperature in S1 is 65-75°C, and the reaction time is 1-3 hours.

[0021] In one implementation, the heating temperature in S2 is 85-95℃, and the reaction time is 1-3h.

[0022] In one embodiment, the acrylic pressure-sensitive adhesive requires the addition of an isocyanate curing agent, and the amount of curing agent used is 0.3-0.6% of the weight of the acrylic pressure-sensitive adhesive.

[0023] A third aspect of the present invention provides an application of an optical-grade high-resilience acrylic pressure-sensitive adhesive for the preparation of products with high light transmittance and high peel strength.

[0024] Compared with the prior art, the present invention has the following beneficial effects: (1) The optical grade high resilience acrylic pressure-sensitive adhesive of the present invention uses isooctyl acrylate and 2-ethylhexyl acrylate in a molar ratio of (50-60):(20-30) to achieve a balance between tensile strength and elongation at break, thereby achieving excellent resilience.

[0025] (2) The optical-grade high-resilience acrylic pressure-sensitive adhesive of the present invention uses methyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate and N,N-diethylacrylamide in a molar ratio of (5-10):(5-10):(2-6):(1-3) to graft rigid groups on the main chain molecule, thereby improving the rigidity of the overall structure and increasing the overall molecular weight. This results in a significant increase in the elasticity of the resin and a corresponding increase in the storage modulus. The molecular weight of the resin is also enhanced, and the chain segments can more stably transmit stress and return to their original position after being subjected to external force, thereby reducing indentation.

[0026] (3) The optical-grade high-resilience acrylic pressure-sensitive adhesive of the present invention adopts a two-stage polymerization process, introducing different long and short chains on the acrylic molecular chain at different temperatures, avoiding self-crosslinking between monomers to form small molecule resin, and continuously increasing the molecular chain length, ultimately increasing the molecular weight. It achieves accurate control of long molecular chains and molecular weight, and can stably induce multiple bipolar monomers on the long molecular chain, thereby improving the cohesive strength of the resin.

[0027] (4) The optical-grade high-resilience acrylic pressure-sensitive adhesive of the present invention forms multiple branches with hydroxyl and carboxyl groups on the long chain molecules through grafting of various acrylic monomers, forming a dense "rake" structure, thereby improving the weather resistance and adhesion of the resin.

[0028] (5) The optical-grade high-resilience acrylic pressure-sensitive adhesive of the present invention has a peel strength of 11.2-12.5 N / 25 mm, a visible light transmittance of 92.1-92.4%, a haze of 0.6-0.8%, a 180° tensile strength of 1.4-1.6 mPa, an elongation at break of 640-730%, and a resilience of 65-68%, and has excellent comprehensive performance.

[0029] (6) The optical-grade high-resilience acrylic pressure-sensitive adhesive of the present invention adopts a pure acrylic system, avoids the introduction of phenolic resin, reduces the use of colored system initiators, improves the refractive index of the resin, achieves optical-grade transparency, and realizes long-term weather resistance. Detailed Implementation

[0030] Example 1 An optical-grade high-resilience acrylic pressure-sensitive adhesive is prepared by means of raw materials including 102 parts of acrylic monomer, 0.4 parts of crosslinking agent, 0.1 parts of initiator, 0.03 parts of antioxidant and 130 parts of solvent, by molar amount.

[0031] The acrylic monomers include soft monomers and hard monomers, and the molar ratio of the soft monomers to the hard monomers is 80:20.

[0032] The soft monomers include isooctyl acrylate and 2-ethylhexyl acrylate in a molar ratio of 55:25.

[0033] The hard monomers include methyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, and N,N-diethylacrylamide in a molar ratio of 8:7:5:2.

[0034] The crosslinking agent is diethylene glycol dimethacrylate.

[0035] The initiator is azobisisobutyronitrile.

[0036] The antioxidant is Irganox 1010.

[0037] The solvent comprises toluene, propylene glycol methyl acetate and ethyl acetate in a molar ratio of 15:15:100.

[0038] A method for preparing an optical-grade high-resilience acrylic pressure-sensitive adhesive includes the following steps: S1 mixes 70 mol% acrylic monomer with solvent, then adds 70 mol% initiator dropwise and stirs at a stirring speed of 300 r / min. The mixture is then heated to 71 °C for a prepolymerization reaction for 2.5 h to form a prepolymer. S2 adds the remaining 30 mol% of acrylic monomer to the prepolymer, and simultaneously adds the remaining 30 mol% of initiator and crosslinking agent. The stirring speed is 200 r / min, and the temperature is further increased to 90℃ for 1.5 h to obtain the pressure-sensitive adhesive precursor. After S3 is cooled to 40℃, an antioxidant is added to the pressure-sensitive adhesive precursor, and the mixture is stirred at 150r / min for 1h to obtain optical-grade high-resilience acrylic pressure-sensitive adhesive.

[0039] The acrylic pressure-sensitive adhesive requires the addition of an isocyanate curing agent, with the amount of curing agent being 0.6% of the weight of the acrylic pressure-sensitive adhesive. The isocyanate is purchased from Covestro N3390.

[0040] Example 2 An optical-grade high-resilience acrylic pressure-sensitive adhesive is prepared by means of raw materials comprising 101 parts acrylic monomer, 0.4 parts crosslinking agent, 0.1 parts initiator, 0.02 parts antioxidant, and 130 parts solvent, by molar ratio. The acrylic monomer comprises soft monomer and hard monomer, wherein the molar ratio of soft monomer to hard monomer is 79:22.

[0041] The soft monomers include isooctyl acrylate and 2-ethylhexyl acrylate in a molar ratio of 52:27.

[0042] The hard monomers include methyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, and N,N-diethylacrylamide in a molar ratio of 8:7:5:2.

[0043] The acrylic pressure-sensitive adhesive requires the addition of an isocyanate curing agent, with the amount of curing agent being 0.4% of the weight of the acrylic pressure-sensitive adhesive. The isocyanate is purchased from Bayer L75.

[0044] The remaining implementation methods are the same as in Example 1.

[0045] Example 3 An optical-grade high-resilience acrylic pressure-sensitive adhesive is prepared by means of raw materials comprising 102 parts of acrylic monomer, 0.4 parts of crosslinking agent, 0.1 parts of initiator, 0.02 parts of antioxidant, and 130 parts of solvent, by molar ratio. The acrylic monomer comprises soft monomer and hard monomer, wherein the molar ratio of soft monomer to hard monomer is 80:22.

[0046] The soft monomers include isooctyl acrylate and 2-ethylhexyl acrylate in a molar ratio of 58:22.

[0047] The hard monomers include methyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, and N,N-diethylacrylamide in a molar ratio of 8:7:5:2.

[0048] The acrylic pressure-sensitive adhesive requires the addition of an isocyanate curing agent, with the amount of curing agent being 0.5% of the weight of the acrylic pressure-sensitive adhesive. The isocyanate is purchased from Wanhua HT100.

[0049] The remaining implementation methods are the same as in Example 1.

[0050] Example 4 An optical-grade high-resilience acrylic pressure-sensitive adhesive is prepared by means of 100 parts of acrylic monomer, 0.4 parts of crosslinking agent, 0.1 parts of initiator, 0.02 parts of antioxidant, and 130 parts of solvent, by molar ratio. The acrylic monomer comprises soft monomer and hard monomer, with a molar ratio of soft monomer to hard monomer of 80:20.

[0051] The soft monomers include isooctyl acrylate and 2-ethylhexyl acrylate in a molar ratio of 55:25.

[0052] The hard monomers include methyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, and N,N-diethylacrylamide in a molar ratio of 10:5:3:2.

[0053] The acrylic pressure-sensitive adhesive requires the addition of an isocyanate curing agent, with the amount of curing agent being 0.3% of the weight of the acrylic pressure-sensitive adhesive. The isocyanate was purchased from Mitsui D-101E.

[0054] The remaining implementation methods are the same as in Example 1.

[0055] Example 5 An optical-grade high-resilience acrylic pressure-sensitive adhesive, prepared by means of raw materials including 99 parts acrylic monomer, 0.4 parts crosslinking agent, 0.1 parts initiator, 0.02 parts antioxidant, and 130 parts solvent, by molar ratio. The acrylic monomer comprises soft monomer and hard monomer, wherein the molar ratio of soft monomer to hard monomer is 80:19.

[0056] The soft monomers include isooctyl acrylate and 2-ethylhexyl acrylate in a molar ratio of 55:25.

[0057] The hard monomers include methyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, and N,N-diethylacrylamide in a molar ratio of 5:10:2:2.

[0058] The acrylic pressure-sensitive adhesive requires the addition of an isocyanate curing agent, with the amount of curing agent being 0.4% of the weight of the acrylic pressure-sensitive adhesive. The isocyanate is purchased from Covestro N75.

[0059] The remaining implementation methods are the same as in Example 1.

[0060] Comparative Example 1 An optical-grade high-resilience acrylic pressure-sensitive adhesive, the specific implementation method is the same as in Example 1.

[0061] The difference lies in the preparation method of an optical-grade high-resilience acrylic pressure-sensitive adhesive, which includes the following steps: A one-stage polymerization process was adopted, in which all materials were added to the reactor, the stirring speed was 300 r / min, the temperature was raised to 71℃, and the reaction was carried out for 6 hours to obtain acrylic pressure-sensitive adhesive.

[0062] Comparative Example 2 An optical-grade high-resilience acrylic pressure-sensitive adhesive is prepared by means of raw materials including 102 parts of acrylic monomer, 0.4 parts of crosslinking agent, 0.1 parts of initiator, 0.03 parts of antioxidant, and 130 parts of solvent, by molar amount.

[0063] The acrylic monomers include soft monomers and hard monomers, and the molar ratio of the soft monomers to the hard monomers is 80:20.

[0064] The soft monomers include isooctyl acrylate and 2-ethylhexyl acrylate in a molar ratio of 60:20.

[0065] The hard monomers include methyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, and N,N-diethylacrylamide in a molar ratio of 8:7:5:2.

[0066] The remaining implementation methods are the same as in Example 1.

[0067] Comparative Example 3 An optical-grade high-resilience acrylic pressure-sensitive adhesive is prepared by means of raw materials including 102 parts of acrylic monomer, 0.4 parts of crosslinking agent, 0.1 parts of initiator, 0.03 parts of antioxidant, and 130 parts of solvent, by molar amount.

[0068] The acrylic monomers include soft monomers and hard monomers, and the molar ratio of the soft monomers to the hard monomers is 80:20.

[0069] The soft monomers include isooctyl acrylate and 2-ethylhexyl acrylate in a molar ratio of 40:40.

[0070] The hard monomers include methyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, and N,N-diethylacrylamide in a molar ratio of 8:7:5:2.

[0071] The remaining implementation methods are the same as in Example 1.

[0072] Comparative Example 4 An optical-grade high-resilience acrylic pressure-sensitive adhesive is prepared by means of raw materials including 102 parts of acrylic monomer, 0.4 parts of crosslinking agent, 0.1 parts of initiator, 0.03 parts of antioxidant, and 130 parts of solvent, by molar amount.

[0073] The acrylic monomers include soft monomers and hard monomers, and the molar ratio of the soft monomers to the hard monomers is 80:20.

[0074] The soft monomers include isooctyl acrylate and 2-ethylhexyl acrylate in a molar ratio of 55:25.

[0075] The hard monomers include isobornyl methacrylate, hydroxyethyl methacrylate, and N,N-diethylacrylamide in a molar ratio of 15:5:2.

[0076] The remaining implementation methods are the same as in Example 1.

[0077] Comparative Example 5 An optical-grade high-resilience acrylic pressure-sensitive adhesive is prepared by means of raw materials including 102 parts of acrylic monomer, 0.4 parts of crosslinking agent, 0.1 parts of initiator, 0.03 parts of antioxidant, and 130 parts of solvent, by molar amount.

[0078] The acrylic monomers include soft monomers and hard monomers, and the molar ratio of the soft monomers to the hard monomers is 80:20.

[0079] The soft monomers include isooctyl acrylate and 2-ethylhexyl acrylate in a molar ratio of 55:25.

[0080] The hard monomers include methyl methacrylate, hydroxyethyl methacrylate and N,N-diethylacrylamide in a molar ratio of 15:5:2.

[0081] The remaining implementation methods are the same as in Example 1.

[0082] Comparative Example 6 An optical-grade high-resilience acrylic pressure-sensitive adhesive is prepared by means of raw materials including 102 parts of acrylic monomer, 0.5 parts of initiator, 0.03 parts of antioxidant, and 130 parts of solvent, by molar amount.

[0083] The remaining implementation methods are the same as in Example 1.

[0084] Comparative Example 7 An optical-grade high-resilience acrylic pressure-sensitive adhesive is prepared by means of raw materials including 102 parts of acrylic monomer, 0.4 parts of crosslinking agent, 0.1 parts of initiator, 0.03 parts of antioxidant, 130 parts of solvent, and 10 parts of terpene phenolic resin.

[0085] The terpene phenolic resin was purchased from Arakawa Chemicals, Japan, and its brand name is 803L.

[0086] The remaining implementation methods are the same as in Example 1.

[0087] Performance testing 1. The acrylic pressure-sensitive adhesives prepared in the examples and comparative examples were mixed with curing agents in the corresponding proportions, and then ethyl acetate was added to adjust the solid content to 30%. A 10μm thick pressure-sensitive adhesive was coated on a 50μm PET film using a coating sampler from Kejian Instruments at a speed of 4 m / min. After passing through three ovens at 60℃-80℃-100℃, a 23μm PET release film was laminated and rolled up. The finished film sample was placed in a 50℃ oven for 48 hours to obtain the finished film. Further tests were conducted on the 180° peel strength, light transmittance, haze, and color difference after 1000 hours of UV aging.

[0088] The 180° peel strength of the finished film was tested according to GB / T 2792-2014; The transmittance and haze of the finished film were tested according to GB / T 2410-2008. The color difference value change of the finished film after 1000 hours of UV aging was tested according to GB / T 16422.3-2014. The test results are shown in Table 1.

[0089] 2. The acrylic pressure-sensitive adhesives prepared in the examples and comparative examples were mixed with curing agents according to the corresponding ratios, and ethyl acetate was added to adjust the solid content to 35%. A 200μm thick pressure-sensitive adhesive was coated onto a 50μm release film using a four-sided applicator. The film was then placed in a 60℃ oven for 5 minutes and then in a 120℃ oven for 5 minutes. Finally, a 50μm release film was attached, and the film was cured in a 50℃ oven for 48 hours to obtain a pure adhesive film. The upper and lower release films were removed during the test.

[0090] The tensile strength and elongation at break of the pure adhesive film were tested in accordance with GB / T 528-2009. The resilience of the pure rubber film was tested according to ASTM D7121. The test results are shown in Table 2.

[0091] Table 1

[0092] Table 2

[0093] By comparing Examples 1-3 with Comparative Examples 2-3, it can be seen that the present invention achieves a balance between tensile strength and elongation at break by selecting isooctyl acrylate and 2-ethylhexyl acrylate as the main raw materials for preparing acrylic pressure-sensitive adhesives and limiting the molar ratio of isooctyl acrylate and 2-ethylhexyl acrylate as acrylic pressure-sensitive adhesives within a specific range, thereby achieving excellent resilience.

[0094] As can be seen from Example 1 and Comparative Example 1, the two-stage synthesis process can carry out the reaction more fully, obtain higher molecular weight and a combination of long and short molecular chains, thereby achieving a higher resilience. As can be seen from Example 1 and Comparative Example 4, an excessively high proportion of isoborneol acrylate will lead to a decrease in tensile strength and a decrease in resilience. As can be seen from Example 1 and Comparative Example 5, an excessively high proportion of methyl methacrylate will increase the rigidity of the adhesive layer. Although the cohesive strength is improved, the flexibility and resilience are reduced. As can be seen from Example 1 and Comparative Example 6, without the participation of diethylene glycol dimethacrylate in the reaction, a sufficient number of strong molecular chains cannot be provided, resulting in a decrease in the overall tensile strength and resilience of the adhesive layer. As can be seen from Example 1 and Comparative Example 6, terpene phenolic resin can indeed improve peel strength, but its high TG point and poor aging resistance make the product unable to meet the requirements of optical grade, and its resilience is also poor.

Claims

1. An optical-grade high-resilience acrylic pressure-sensitive adhesive, characterized in that, The raw materials for preparation include acrylic monomers, crosslinking agents, initiators, antioxidants and solvents; the acrylic monomers include soft monomers and hard monomers, the soft monomers include carbon-carbon double bonds, the soft monomers include isooctyl acrylate and 2-ethylhexyl acrylate, and the molar ratio of isooctyl acrylate and 2-ethylhexyl acrylate is (50-60):(20-30).

2. The optical-grade high-resilience acrylic pressure-sensitive adhesive according to claim 1, characterized in that, The hard monomer includes at least one of methyl methacrylate, methyl acrylate, isobornyl methacrylate, hydroxyethyl methacrylate, and N,N-diethylacrylamide.

3. The optical-grade high-resilience acrylic pressure-sensitive adhesive according to claim 2, characterized in that, The molar ratio of methyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate and N,N-diethylacrylamide is (5-10):(5-10):(2-6):(1-3).

4. The optical-grade high-resilience acrylic pressure-sensitive adhesive according to claim 1, characterized in that, The crosslinking agent includes at least one of diethylene glycol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate, or carbamate dimethacrylate.

5. The optical-grade high-resilience acrylic pressure-sensitive adhesive according to claim 1, characterized in that, The crosslinking agent accounts for 0.10-0.3% of the raw materials used in the preparation of optical-grade high-resilience acrylic pressure-sensitive adhesive.

6. A method for preparing an optical-grade high-resilience acrylic pressure-sensitive adhesive according to any one of claims 1-5, characterized in that, Includes the following steps: S1 involves mixing 60-80 mol% of acrylic monomer with a solvent, then adding 60-80 mol% of initiator dropwise while stirring, and heating to carry out a prepolymerization reaction to form a prepolymer. S2 adds the remaining 20-40 mol% of acrylic monomer to the prepolymer, and simultaneously adds the remaining 20-40 mol% of initiator and crosslinking agent. The reaction is then continued by heating to obtain the pressure-sensitive adhesive precursor. After S3 is cooled, an antioxidant is added to the pressure-sensitive adhesive precursor, and the mixture is stirred to obtain an optical-grade high-resilience acrylic pressure-sensitive adhesive.

7. The method for preparing the optical-grade high-resilience acrylic pressure-sensitive adhesive according to claim 6, characterized in that, Specifically, S1 involves mixing 70 mol% of acrylic acid monomer with a solvent, then adding 70 mol% of initiator dropwise while stirring, heating to carry out a prepolymerization reaction, and maintaining the temperature for 1-3 hours to form a prepolymer.

8. The method for preparing the optical-grade high-resilience acrylic pressure-sensitive adhesive according to claim 6, characterized in that, The temperature in S1 is 65-75℃, and the reaction time is 1-3h.

9. The method for preparing the optical-grade high-resilience acrylic pressure-sensitive adhesive according to claim 6, characterized in that, The temperature in S2 is 85-95℃, and the reaction time is 1-3h.

10. An application of the optical-grade high-resilience acrylic pressure-sensitive adhesive according to any one of claims 1-5, characterized in that, It is used to prepare products with high light transmittance and high peel strength.

Images