Cation-cured optical glue and preparation method thereof
By using cationic curing optical adhesives and components such as acrylic epoxy resin oligomers, the problem of UV adhesives being difficult to cure in shadow areas has been solved, achieving complete curing in shadow areas and improving optical performance, thus ensuring the stability and imaging quality of the optical system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-27
- Publication Date
- 2026-03-13
AI Technical Summary
Existing UV adhesives are difficult to cure in the shaded areas of optical components, resulting in reduced bonding strength, affecting the stability and reliability of the optical system, and potentially causing optical performance degradation.
The optical adhesive uses cationic curing. The continuous dark reaction after UV activation ensures curing in the shadow area. The cationic system is not affected by oxygen and has a transmittance and refractive index close to that of optical glass. It uses a combination of acrylic epoxy resin oligomers, epoxy resin monomers, diluents and photoinitiators to achieve a comprehensive curing effect.
Complete curing of the shadow area was achieved, which improved the bonding strength and optical performance, ensured the stability of the optical system and the imaging quality, and avoided the degradation of optical performance caused by incomplete curing.
Smart Images
Figure SMS_1 
Figure SMS_2 
Figure SMS_3
Abstract
Description
Technical Field
[0001] This invention relates to the field of adhesive materials, and in particular to a cationic curing optical adhesive and its preparation method. Background Technology
[0002] In the field of modern optics, UV adhesives, with their advantages of rapid curing and high transparency, have become an indispensable material in the bonding and encapsulation of optical components. From the assembly of precision optical lenses to the fabrication of complex optoelectronic devices, the application of UV adhesives is ubiquitous, greatly promoting the miniaturization and high performance of optical products.
[0003] However, with the continuous advancement of optical technology, the performance requirements for UV adhesives are becoming increasingly stringent. In practical applications, some problems have gradually emerged, such as those related to shadow curing, optics, and oxygen curing. Among these, the inability to cure in shadow areas is particularly prominent. In complex optical structures, due to the shape, layout, and mutual obstruction of optical components, some adhesives are located in shadow areas where ultraviolet light cannot reach. For example, in the bonding of multi-layered optical lenses, the adhesive between the bottom and middle lenses is easily blocked by the upper lens, preventing it from receiving sufficient ultraviolet light. Similarly, in optical modules with complex support structures, the adhesive areas obstructed by the support structure face the same predicament. In these shadow areas, UV adhesives cannot undergo sufficient photopolymerization, resulting in incomplete curing. This not only reduces bond strength, making optical components prone to loosening and displacement during subsequent use, affecting the stability and reliability of the optical system, but may also lead to the deterioration of optical performance, such as stress concentration, which can cause lens deformation, affecting light transmission and focusing, and reducing image quality.
[0004] To solve this problem, the industry urgently needs to develop new types of adhesives. These adhesives must not only possess excellent basic optical properties, such as high light transmittance and a suitable refractive index to ensure minimal impact on the optical performance of optical systems, but also achieve breakthroughs in curing characteristics, overcoming the problem of incomplete or ineffective curing in shaded areas. However, reliable solutions are currently lacking. Summary of the Invention
[0005] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a cationic curable optical adhesive and its preparation method. Its sustained dark reaction after UV activation effectively ensures curing in the shadow area, while the curing of the cationic system is completely unaffected by oxygen, and its transmittance and refractive index are close to those of optical glass.
[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a cationic curable optical adhesive, comprising the following raw material components by weight: 30-60 parts of acrylic epoxy resin oligomer, 20-40 parts of epoxy resin monomer, 15-35 parts of epoxy resin diluent, 1-5 parts of first photoinitiator, and 0.1-0.5 parts of additives. The raw materials for preparing acrylic epoxy resin oligomers include, by weight: 25-60 parts of soft monomer, 20-40 parts of hard monomer, 3-30 parts of functional monomer, 7-30 parts of amide monomer, and 0.2-1 parts of second photoinitiator.
[0007] Preferably, the soft monomer is selected from at least one of butyl acrylate, octyl acrylate, isooctyl acrylate, isodecanyl acrylate, and dodecyl acrylate; The hard monomer is selected from at least one of dicyclopentenyl ethoxyacrylate, isobornyl acrylate, 2-phenoxyethyl acrylate, 3,5,5-trimethylcyclohexyl acrylate, and tricyclodecane methanol monoacrylate. Preferably, the functional monomer is selected from at least one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, acrylmorpholine, N,N-dimethylacetylacetamide, N,N-diethylacetylacetamide, glycidyl methacrylate, and 3,4-epoxycyclohexyl (meth)acrylate. The second photoinitiator is selected from at least one of 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.
[0008] Preferably, the acrylic epoxy resin oligomer is prepared by the following method: Mix the soft monomer, hard monomer, functional monomer, amide monomer, and photoinitiator, control the temperature at 20-30℃, and stir with an inert gas for 15-60 minutes. Then, irradiate with ultraviolet light at an intensity of 10-50 mw / cm². 2 The mixture is stirred and reacted for 1-5 hours to obtain the acrylic epoxy resin oligomer.
[0009] Preferably, the soft monomer is selected from a mixture of butyl acrylate and isooctyl acrylate, the hard monomer is selected from a mixture of isobornyl acrylate and 3,5,5-trimethylcyclohexyl acrylate, and the functional monomer is selected from a mixture of hydroxyethyl acrylate, acrylmorpholine and 3,4-epoxycyclohexyl methacrylate.
[0010] Preferably, the epoxy resin monomer is selected from at least one of 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester, bis(3,4-epoxycyclohexyl(methyl)) adipate, poly((2-epoxyethylene)-1,2-cyclohexanediol), and 128 bisphenol A epoxy resin.
[0011] Preferably, the epoxy resin diluent is selected from at least one of 4-vinyl-1-cyclohexene diepoxide, dipentene dioxide, and 3-ethyl-2-oxabutane methanol.
[0012] Preferably, the first photoinitiator is selected from at least one of thiohexafluoroantimony salt, iodohexafluoroantimony salt, thiohexafluorophosphate salt, iodohexafluorophosphate salt, and cumeneferrocene hexafluorophosphate.
[0013] Preferably, the additive is selected from at least one of defoamers, wetting agents, adhesion promoters, and coupling agents.
[0014] The present invention also provides a method for preparing the cationic curing optical adhesive as described above, comprising the following steps: mixing acrylic epoxy resin oligomer, epoxy resin monomer, epoxy resin diluent, first photoinitiator and additives, stirring evenly, degassing, filtering and discarding filter residue to obtain the cationic curing optical adhesive.
[0015] The beneficial effects of this invention are: This invention provides a cationic curable optical adhesive and its preparation method. The adhesive can achieve dark reaction in the shadow area after UV activation until there is no significant difference from the irradiated area. At the same time, the curing of the cationic system is completely unaffected by oxygen and can approach the transmittance and refractive index of optical glass. In this invention, by adding a self-made acrylic epoxy resin oligomer, the balance between brittleness and toughness of the epoxy resin system is significantly improved, thereby optimizing the performance of the cured product. In this invention, epoxy groups are introduced into the acrylic epoxy resin oligomer, which can react and crosslink with the monomer after curing, thus avoiding the compatibility problem of using conventional toughened two-phase structures. Detailed Implementation
[0016] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.
[0017] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.
[0018] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.
[0019] This invention provides a cationic curable optical adhesive, comprising the following raw material components by weight: 30-60 parts of acrylic epoxy resin oligomer, 20-40 parts of epoxy resin monomer, 15-35 parts of epoxy resin diluent, 1-5 parts of first photoinitiator, and 0.1-0.5 parts of additives. The raw materials for preparing acrylic epoxy resin oligomers include, by weight: 25-60 parts of soft monomer, 20-40 parts of hard monomer, 3-30 parts of functional monomer, 7-30 parts of amide monomer, and 0.2-1 parts of second photoinitiator.
[0020] The soft monomer is selected from acrylate monomers containing C4-C12 alkyl chain lengths. In a preferred embodiment, the soft monomer is selected from at least one of butyl acrylate, octyl acrylate, isooctyl acrylate, isodecanyl acrylate, and dodecyl acrylate. These monomers act as the soft segment of the main chain in the synthesized acrylic epoxy resin oligomer, providing the product with flexibility and toughness.
[0021] The hard monomer is selected from low-viscosity acrylate monomers containing benzene rings or cyclic structures. In a preferred embodiment, the hard monomer is selected from at least one of dicyclopentenyl ethoxyacrylate, isobornyl acrylate, 2-phenoxyethyl acrylate, 3,5,5-trimethylcyclohexyl acrylate, and tricyclodecane methanol monoacrylate. These low-viscosity acrylate monomers containing benzene rings or cyclic structures act as the hard segment of the main chain in the synthesized acrylic epoxy resin oligomer, providing rigidity to the product.
[0022] In a preferred embodiment, the functional monomer is selected from acrylate monomers containing special functional groups, such as at least one of the following: hydroxyl-type monomers providing strong polarity: hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, etc.; amide-type monomers: acrylomorpholine, N,N-dimethylacetylacetamide, N,N-diethylacetylacetamide; or epoxy monomers providing reactive groups, such as glycidyl methacrylate, 3,4-epoxycyclohexyl(meth)acrylate, etc.
[0023] In a preferred embodiment, the second photoinitiator is selected from at least one of 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.
[0024] In a preferred embodiment, the acrylic epoxy resin oligomer is prepared by the following method: Mix the soft monomer, hard monomer, functional monomer, amide monomer, and photoinitiator, control the temperature at 20-30℃, and stir with an inert gas for 15-60 minutes. Then, irradiate with ultraviolet light at an intensity of 10-50 mw / cm². 2 Stir and react for 1-5 hours to obtain acrylic epoxy resin oligomers.
[0025] In a preferred embodiment, the soft monomer is selected from a mixture of butyl acrylate and isooctyl acrylate, the hard monomer is selected from a mixture of isobornyl acrylate and 3,5,5-trimethylcyclohexyl acrylate, and the functional monomer is selected from a mixture of hydroxyethyl acrylate, acrylmorpholine and 3,4-epoxycyclohexyl methacrylate.
[0026] In a preferred embodiment, the epoxy resin monomer is selected from at least one of 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester, bis(3,4-epoxycyclohexyl(methyl)) adipate, poly((2-epoxyethylene)-1,2-cyclohexanediol), and 128 bisphenol A epoxy resin.
[0027] In a preferred embodiment, the epoxy resin diluent is selected from at least one of 4-vinyl-1-cyclohexene diepoxide, dipentene dioxide, and 3-ethyl-2-oxabutane methanol.
[0028] The first photoinitiator is selected from one or more of iron salts, iodonium salts, and thiodonium salts. In a preferred embodiment, the first photoinitiator is selected from at least one of thiodonium hexafluoroantimonate, iodonium hexafluoroantimonate, thiodonium hexafluorophosphate, iodonium hexafluorophosphate, and cumeneferrocene hexafluorophosphate.
[0029] In a preferred embodiment, the additive is selected from at least one of defoamers, wetting agents, adhesion promoters, and coupling agents, such as BYK 088, BYK, A530, BYK 066N, BYK DISPER 163, BYK, W980, BYK 4500, BYK 4510, A186, A187, etc.
[0030] The present invention also provides a method for preparing the above-mentioned cationic curing optical adhesive, comprising the following steps: mixing acrylic epoxy resin oligomer, epoxy resin monomer, epoxy resin diluent, first photoinitiator and additives, stirring evenly, degassing, filtering and discarding filter residue to obtain cationic curing optical adhesive.
[0031] This invention utilizes a self-made acrylic epoxy resin oligomer and optimizes its performance through a unique formulation design, achieving excellent optical properties, flexibility, and adhesion. The acrylic epoxy resin oligomer of this invention incorporates reactive functional groups, resulting in cured products with excellent uniformity.
[0032] The above is the general concept of the present invention. Based on this, detailed embodiments and comparative examples are provided below to further illustrate the present invention.
[0033] Raw material source description: Preparation example: Synthesis of acrylic epoxy resin oligomers: In a clean, yellow light environment, 10 parts by weight of butyl acrylate, 45 parts by weight of isooctyl acrylate, 10 parts by weight of isobornyl acrylate, 15 parts by weight of 3,5,5-trimethylcyclohexyl acrylate, 6 parts by weight of hydroxyethyl acrylate, 1.8 parts by weight of acryloylmorpholine, 12 parts by weight of 3,4-epoxycyclohexyl methacrylate, and 0.2 parts by weight of photoinitiator 1-hydroxycyclohexylphenyl ketone were added to a reactor vessel. Stirring was started at 150 rpm, nitrogen gas was purged for 30 minutes, and the temperature was controlled at 22℃. Then, ultraviolet light irradiation was applied at an intensity of 17 mw / cm². 2 The reaction time was 3.5 hours to obtain an acrylic epoxy resin oligomer. This oligomer was then used in Examples 1-5 and Comparative Examples 1-4.
[0034] Example 1 A cationic curable optical adhesive is prepared as follows: In a clean, low-humidity environment with yellow light, accurately weigh 40 parts by weight of acrylic epoxy resin oligomer, 30 parts by weight of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarbamate, 25 parts by weight of 3-ethyl-2-oxabutane methanol, 2 parts by weight of hexafluorophosphate thioonium salt PAG 202, 0.1 parts by weight of defoamer BYK 088, 0.2 parts by weight of accelerator BYK 4510, and 0.2 parts by weight of silane coupling agent A186. Stir at 400 rpm for 60 minutes to mix thoroughly and evenly, defoam, filter and discard to obtain the cationic curable optical adhesive.
[0035] Example 2 A cationic curable optical adhesive is prepared as follows: In a clean, low-humidity environment with yellow light, accurately weigh 60 parts by weight of acrylic epoxy resin oligomer, 30 parts by weight of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarbamate, 25 parts by weight of 3-ethyl-2-oxabutane methanol, 2 parts by weight of hexafluorophosphate thioonium salt PAG 202, 0.1 parts by weight of defoamer BYK 088, 0.2 parts by weight of accelerator BYK 4510, and 0.2 parts by weight of silane coupling agent A186. Stir at 400 rpm for 60 minutes to mix thoroughly and evenly, defoam, filter and discard to obtain the cationic curable optical adhesive.
[0036] Example 3 A cationic curable optical adhesive is prepared as follows: In a clean, low-humidity environment with yellow light, accurately weigh 50 parts by weight of acrylic epoxy resin oligomer, 30 parts by weight of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarbamate, 25 parts by weight of 3-ethyl-2-oxabutane methanol, 2 parts by weight of hexafluorophosphate thioonium salt PAG 202, 0.1 parts by weight of defoamer BYK 088, 0.2 parts by weight of accelerator BYK 4510, and 0.2 parts by weight of silane coupling agent A186. Stir at 400 rpm for 60 minutes to mix thoroughly and evenly, defoam, filter and discard to obtain the cationic curable optical adhesive.
[0037] Example 4 A cationic curable optical adhesive is prepared as follows: In a clean, low-humidity environment with yellow light, accurately weigh 50 parts by weight of acrylic epoxy resin oligomer, 20 parts by weight of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarbamate, 25 parts by weight of 3-ethyl-2-oxabutane methanol, 2 parts by weight of hexafluorophosphate thioonium salt PAG 202, 0.1 parts by weight of defoamer BYK 088, 0.2 parts by weight of accelerator BYK 4510, and 0.2 parts by weight of silane coupling agent A186. Stir at 400 rpm for 60 minutes to mix thoroughly and evenly, defoam, filter and discard to obtain the cationic curable optical adhesive.
[0038] Example 5 A cationic curable optical adhesive is prepared as follows: In a clean, low-humidity environment with yellow light, accurately weigh 50 parts by weight of acrylic epoxy resin oligomer, 40 parts by weight of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarbamate, 25 parts by weight of 3-ethyl-2-oxabutane methanol, 2 parts by weight of hexafluorophosphate thioonium salt PAG 202, 0.1 parts by weight of defoamer BYK 088, 0.2 parts by weight of accelerator BYK 4510, and 0.2 parts by weight of silane coupling agent A186. Stir at 400 rpm for 60 minutes to mix thoroughly and evenly, defoam, filter and discard to obtain the cationic curable optical adhesive.
[0039] Comparative Example 1 A cationic curable optical adhesive is prepared as follows: In a clean, low-humidity environment with yellow light, accurately weigh 20 parts by weight of acrylic epoxy resin oligomer, 30 parts by weight of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarbamate, 25 parts by weight of 3-ethyl-2-oxabutane methanol, 2 parts by weight of hexafluorophosphate thioonium salt PAG 202, 0.1 parts by weight of defoamer BYK 088, 0.2 parts by weight of accelerator BYK4510, and 0.2 parts by weight of silane coupling agent A186. Stir at 400 rpm for 60 minutes to mix thoroughly and evenly, defoam, filter and discard to obtain the cationic curable optical adhesive.
[0040] Comparative Example 2 A cationic curable optical adhesive is prepared as follows: In a clean, low-humidity environment with yellow light, accurately weigh 80 parts by weight of acrylic epoxy resin oligomer, 30 parts by weight of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarbamate, 25 parts by weight of 3-ethyl-2-oxabutane methanol, 2 parts by weight of hexafluorophosphate thioonium salt PAG 202, 0.1 parts by weight of defoamer BYK 088, 0.2 parts by weight of accelerator BYK 4510, and 0.2 parts by weight of silane coupling agent A186. Stir at 400 rpm for 60 minutes to mix thoroughly and evenly, defoam, filter and discard to obtain the cationic curable optical adhesive.
[0041] Comparative Example 3 A cationic curable optical adhesive is prepared as follows: In a clean, low-humidity environment with yellow light, accurately weigh 50 parts by weight of acrylic epoxy resin oligomer, 5 parts by weight of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarboxylate, 25 parts by weight of 3-ethyl-2-oxabutane methanol, 2 parts by weight of hexafluorophosphate thioonium salt PAG 202, 0.1 parts by weight of defoamer BYK 088, 0.2 parts by weight of accelerator BYK 4510, and 0.2 parts by weight of silane coupling agent A186. Stir at 400 rpm for 60 minutes to mix thoroughly and evenly, defoam, filter and discard to obtain the cationic curable optical adhesive.
[0042] Comparative Example 4 A cationic curable optical adhesive is prepared as follows: In a clean, low-humidity environment with yellow light, accurately weigh 50 parts by weight of acrylic epoxy resin oligomer, 60 parts by weight of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarbamate, 25 parts by weight of 3-ethyl-2-oxabutane methanol, 2 parts by weight of hexafluorophosphate thioonium salt PAG 202, 0.1 parts by weight of defoamer BYK 088, 0.2 parts by weight of accelerator BYK 4510, and 0.2 parts by weight of silane coupling agent A186. Stir at 400 rpm for 60 minutes to mix thoroughly and evenly, defoam, filter and discard to obtain the cationic curable optical adhesive.
[0043] The adhesives prepared in the examples and comparative examples were applied to substrates and cured to form adhesive films. The corresponding properties were then tested using the following standards and instruments, and the results were recorded. The adhesive curing conditions were LED irradiation at 365nm, with the irradiation energy controlled at 3000mJ / cm². 2 After curing at 25℃ for 48 hours, the film thickness was 25μm.
[0044] The test results are shown in Table 1 below: Table 1 From the above results, we can conclude that: The hardness of Comparative Example 1 is significantly higher and the elongation at break is very low. This is likely due to the low content of acrylic epoxy resin oligomers, resulting in low system toughness and excessive brittleness. The hardness of Comparative Example 2 is significantly lower and the elongation at break is higher. At the same time, the adhesion is drastically reduced. This is likely due to the excessively high content of acrylic epoxy resin oligomers, which leads to excessively high system toughness and too low number of polar bonds. The hardness of Comparative Example 3 is significantly lower and the elongation at break is higher. At the same time, the adhesion is reduced sharply. This should be due to the excessively high toughness of the system caused by the low epoxy resin monomer content, resulting in a low number of polar bonds. The hardness of Comparative Example 4 is significantly higher and the elongation at break is very low. This is likely due to the excessively high content of epoxy resin monomers, which results in low system toughness and excessive brittleness.
[0045] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.
Claims
1. A cationic curable optical adhesive, characterized in that, It includes the following raw material components by weight: 30-60 parts of acrylic epoxy resin oligomer, 20-40 parts of epoxy resin monomer, 15-35 parts of epoxy resin diluent, 1-5 parts of primary photoinitiator, and 0.1-0.5 parts of additives. The raw materials for preparing acrylic epoxy resin oligomers include, by weight: 25-60 parts of soft monomer, 20-40 parts of hard monomer, 10-30 parts of functional monomer, 7-30 parts of amide monomer, and 0.2-1 parts of second photoinitiator.
2. The cationic curable optical adhesive according to claim 1, characterized in that, The soft monomer is selected from at least one of butyl acrylate, octyl acrylate, isooctyl acrylate, isodecanyl acrylate, and dodecyl acrylate; The hard monomer is selected from at least one of dicyclopentenyl ethoxyacrylate, isobornyl acrylate, 2-phenoxyethyl acrylate, 3,5,5-trimethylcyclohexyl acrylate, and tricyclodecane methanol monoacrylate.
3. The cationic curable optical adhesive according to claim 2, characterized in that, The functional monomer is selected from at least one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, acrylmorpholine, N,N-dimethylacetylacetamide, N,N-diethylacetylacetamide, glycidyl methacrylate, and 3,4-epoxycyclohexyl (meth)acrylate. The second photoinitiator is selected from at least one of 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.
4. The cationic curable optical adhesive according to claim 3, characterized in that, The acrylic epoxy resin oligomer was prepared by the following method: Mix the soft monomer, hard monomer, functional monomer, amide monomer, and photoinitiator, control the temperature at 20-30℃, and stir with an inert gas for 15-60 minutes. Then, irradiate with ultraviolet light at an intensity of 10-50 mw / cm². 2 The mixture is stirred and reacted for 1-5 hours to obtain the acrylic epoxy resin oligomer.
5. The cationic curable optical adhesive according to claim 4, characterized in that, The soft monomer is selected from a mixture of butyl acrylate and isooctyl acrylate, the hard monomer is selected from a mixture of isobornyl acrylate and 3,5,5-trimethylcyclohexyl acrylate, and the functional monomer is selected from a mixture of hydroxyethyl acrylate, acrylmorpholine and 3,4-epoxycyclohexyl methacrylate.
6. The cationic curable optical adhesive according to claim 1, characterized in that, The epoxy resin monomer is selected from at least one of 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester, bis(3,4-epoxycyclohexyl(methyl)) adipate, poly((2-epoxyethylene)-1,2-cyclohexanediol), and 128 bisphenol A epoxy resin.
7. The cationic curable optical adhesive according to claim 1, characterized in that, The epoxy resin diluent is selected from at least one of 4-vinyl-1-cyclohexene diepoxide, dipentene dioxide, and 3-ethyl-2-oxabutane methanol.
8. The cationic curable optical adhesive according to claim 1, characterized in that, The first photoinitiator is selected from at least one of thiohexafluoroantimonate, iodohexafluoroantimonate, thiohexafluorophosphate, iodohexafluorophosphate, and cumeneferrocene hexafluorophosphate.
9. The cationic curable optical adhesive according to claim 1, characterized in that, The additives are selected from at least one of defoamers, wetting agents, adhesion promoters, and coupling agents.
10. A method for preparing a cationic curable optical adhesive as described in any one of claims 1-9, characterized in that, The process includes the following steps: mixing acrylic epoxy resin oligomer, epoxy resin monomer, epoxy resin diluent, first photoinitiator and additives, stirring evenly, degassing, filtering and discarding filter residue to obtain the cationic cured optical adhesive.