Optical optical clear adhesive (OCA) with high flexibility and high adhesion and preparation method thereof

Abstract

The invention discloses an optical optical clear adhesive (OCA) with high flexibility and high adhesion and a preparation method thereof, and belongs to the technical field of organic compound luminescence. The optical OCA with high flexibility and high adhesion is prepared from the following components in parts by weight: an acrylate prepolymer, 0.01 to 1.2 parts of a main photoinitiator, 0.05 to 0.2 part of a reactive diluent, 0.05 to 0.2 part of a coupling agent and other additives. In a raw material mixing stage, stirring parameters are accurately regulated and controlled to realize microscopic uniform dispersion; in the polymerization link, the photopolymerization stabilizes the reaction process by accurately controlling the radiation intensity and time, and the thermal polymerization optimizes the temperature curve and time length to ensure the reaction sufficiency; according to the coating process, the thickness is accurately controlled according to purposes, and the binding force of the film layer is strengthened by adopting a rolling technology. Through dispersion-reaction-molding three-dimensional cooperative regulation and control, the bottlenecks of non-uniform mixing, polymerization fluctuation, poor coating precision and the like of the traditional process are broken through, and the performance stability and the application suitability of the product are ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic compound luminescence, and particularly relates to an optical optical fiber (OCA) with high flexibility and high adhesion and a preparation method thereof. Background Art

[0002] In the current field of optical adhesive preparation, the preparation method of traditional optical OCA is usually based on acrylate polymers. The common preparation process is to simply mix acrylate monomers, photoinitiators and some additives to form an adhesive through thermal polymerization or photopolymerization. In terms of raw material selection, the types of acrylate monomers are relatively conventional, such as ordinary methyl acrylate, ethyl acrylate, etc., and photoinitiators mostly use a common single type and the dosage is relatively fixed. In terms of polymerization process, there is a lack of precise optimization of thermal polymerization temperature and time control, and photopolymerization is relatively extensive in the regulation of radiation intensity and time. In the coating and molding stage, the glue is generally simply coated on the release film, and there is a lack of precise control of the coating thickness and optimization measures for lamination with the release film.

[0003] Patent application publication number CN119286436A discloses a method for preparing a high-step-difference-filled OCA optical adhesive and tape. The method uses a blend of two acrylic resins with different molecular weights to improve the adhesive's ability to fill perforated polarizers. A silane coupling agent is added to the formula to enhance interfacial adhesion. However, high-step-difference filling relies on high-hardness resins, which may lead to a decrease in the overall flexibility of the colloid. Patent application publication number CN116790221A discloses a method for preparing a flexible, highly waterproof, and high-temperature resistant OCA optical adhesive and an OCA optical adhesive film. By blending polyurethane acrylate with polydimethylsiloxane prepolymer, the colloid is given high waterproofness, high-temperature resistance, and flexibility. A medium-temperature curing process is used to simplify the process and avoid gel problems. However, the low surface energy of polydimethylsiloxane may reduce adhesion to some substrates, which may result in insufficient interfacial bonding strength.

[0004] After consulting the existing technology, it was found that the combination of acrylate monomers used in traditional OCA cannot give the product a sufficiently low glass transition temperature (Tg). When faced with application scenarios such as folding screens that require frequent bending of materials, ordinary OCA is prone to problems such as cracking and debonding of the adhesive layer during repeated bending due to its poor flexibility, which seriously affects the service life and reliability of the product. In addition, the traditional preparation method fails to effectively enhance the interaction between adhesives and optical components of different materials (such as glass, PC, PMMA, and ITO layers, etc.) in terms of raw material selection and process control. This makes the OCA not firmly bonded to these materials in actual use, and debonding is prone to occur, reducing the stability and reliability of the optical product. Summary of the Invention

[0005] The object of the present invention is to provide an optical OCA with high flexibility and high adhesion and a preparation method thereof, so as to improve the flexibility and adhesion of the optical OCA.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] An optical OCA with high flexibility and high adhesion, comprising, by weight, an acrylate prepolymer, 0.01-1.2 parts of a primary photoinitiator, 0.05-0.2 parts of a reactive diluent, 0.05-0.2 parts of a coupling agent, and other additives;

[0008] The acrylate prepolymer comprises 55-85 parts of isooctyl acrylate, 5-15 parts of lauryl methacrylate, 8-22 parts of isobornyl acrylate, 5-15 parts of acrylonitrile, 0.02-0.2 parts of a second photoinitiator, 0.02-0.05 parts of a molecular weight regulator, and 0.01-0.1 parts of a second cross-linking agent;

[0009] The other additives include 2-4 parts of allyl succinimidyl carbonate, 1-3 parts of hexafluorobisphenol A diacrylate, 3-5 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 3-5 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 6-8 parts of other polymerizable monomers, 20-30 parts of diluent, 0.5-1 part of antioxidant and 0.5-1 part of defoaming agent.

[0010] Furthermore, the main photoinitiator is one or a combination of benzoin ether and benzophenone photoinitiators.

[0011] Furthermore, the active diluent is one or a combination of butyl acrylate, lauryl acrylate and isooctyl acrylate.

[0012] Furthermore, the coupling agent is one or a combination of γ-aminopropyltriethoxysilane, vinyltriethoxysilane and γ-(methacryloyloxy)propyltrimethoxysilane.

[0013] Acrylate prepolymer: As a foundational raw material, its composition plays a key role in the performance of OCA. In this invention, the acrylate prepolymer is composed of the following components in parts by weight: isooctyl acrylate provides good flexibility and polymerization activity; lauryl methacrylate helps adjust the polymer's glass transition temperature and flexibility; isobornyl acrylate improves the adhesive's hardness and abrasion resistance; and acrylonitrile strengthens the adhesive's bond to the adhered material. It also contains a second photoinitiator to initiate polymerization at a specific stage; a molecular weight regulator to control the polymer's molecular weight distribution; and a second crosslinker to optimize the crosslinking structure and enhance the product's overall performance. By carefully selecting these monomers and precisely controlling their ratios, the molecular structure and properties of the polymer can be effectively adjusted, addressing the lack of flexibility in traditional OCAs.

[0014] Photoinitiator: The primary photoinitiator initiates polymerization under light. Its type and dosage are selected based on the actual polymerization process and product performance requirements. Common photoinitiators include benzoin ethers and benzophenones. Compared to traditional methods that use a single, fixed dosage of photoinitiator, this method allows for flexible adjustment of the type and dosage of photoinitiator based on varying polymerization requirements, enabling more precise control of the polymerization reaction process and improving product quality and stability.

[0015] Reactive diluents: Used to adjust the viscosity of the glue and improve processing performance. Common reactive diluents include butyl acrylate and isooctyl acrylate. The appropriate amount of reactive diluent added can improve the fluidity and uniformity of the glue during the coating and molding process, helping to solve the problem of poor filling properties of traditional OCA.

[0016] Coupling agents, such as silane coupling agents like γ-aminopropyltriethoxysilane, are used to enhance the bond between adhesives and adherends of different materials. The addition of coupling agents creates a chemical bond or physical adsorption between the adhesive and adherend, significantly improving bond strength and addressing the low bond strength of traditional OCAs.

[0017] Other additives include allyl succinimidyl carbonate, which improves the product's weather resistance; hexafluorobisphenol A diacrylate, which enhances the product's chemical stability and optical properties; 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, which improves the adhesive's cross-linking structure and mechanical properties; 2,2'-bis(trifluoromethyl)diaminobiphenyl, which enhances the product's high-temperature resistance; other polymerizable monomers, which further optimize the polymer structure; diluents, which help adjust the adhesive's viscosity and fluidity; antioxidants, which prevent oxidation and aging during preparation and storage; and defoamers, which eliminate bubbles in the adhesive system to ensure product quality. The synergistic effect of these various functional additives effectively improves the product's weather resistance, optical properties, and overall stability, addressing the shortcomings of traditional OCA in terms of weather resistance and optical properties.

[0018] A method for preparing an optical OCA with high flexibility and high adhesion comprises the following steps:

[0019] S1. Raw material preparation and mixing: Add the acrylate prepolymer into the reaction vessel and stir, then slowly add the photoinitiator, reactive diluent, coupling agent and other additives to ensure that all raw materials are fully mixed;

[0020] S2. Polymerization process: transferring the uniformly mixed raw materials to an ultraviolet radiation device for radiation to initiate a polymerization reaction to form an OCA optical adhesive with preliminary properties; placing the OCA optical adhesive with preliminary properties in a reaction container for heating and reaction to generate the OCA optical adhesive;

[0021] S3. The prepared OCA optical adhesive is evenly coated on the release film through precision coating equipment. After coating, it is covered with another layer of release film and the optical adhesive layer is tightly fitted to the release film by rolling and compacted into shape to obtain an optical OCA with high flexibility and high adhesion.

[0022] Furthermore, the stirring speed is 200-500 r / min; and the stirring time is 30-60 min.

[0023] Furthermore, the ultraviolet radiation intensity is 50-100 mW / cm 2 ; Radiation time is 5-15 minutes.

[0024] Furthermore, the heating reaction is carried out by heating the temperature to 60-80° C. and reacting at this temperature for 2-4 hours.

[0025] Furthermore, the optical OCA with high flexibility and high adhesion has a thickness of 25-250 μm.

[0026] Beneficial effects of the present invention:

[0027] (1) This invention improves product performance and consistency through full-process optimization: During the raw material mixing stage, stirring parameters are precisely controlled to achieve microscopic uniform dispersion; during the polymerization process, photopolymerization stabilizes the reaction process by precisely controlling the radiation intensity and time, and thermal polymerization optimizes the temperature curve and duration to ensure the sufficiency of the reaction; the coating process precisely controls the thickness according to the application and uses roller pressing technology to strengthen the film layer bonding. Through the three-dimensional coordinated control of "dispersion-reaction-molding", the bottlenecks of traditional processes such as uneven mixing, polymerization fluctuations, and poor coating accuracy are overcome, ensuring product performance stability and application adaptability.

[0028] (2) The new OCA optical adhesive developed by the present invention systematically solves the performance shortcomings of traditional products through material innovation and process optimization. ① High flexibility: By adding ultra-low glass transition temperature and high flexibility monomers to the acrylate prepolymer, the flexibility and service life of the product are effectively improved, solving the problem of easy cracking and debonding of traditional OCA; ② High filling property: The OCA optical adhesive prepared by the present invention has high filling property, can better fill the ink layer or tiny gaps, adapt to irregular surfaces, and meet the market demand for high filling performance. ③ High adhesion: The special raw material formula design and preparation process optimization enhance the adhesion between the adhesive and optical components of different materials, greatly improve the bonding strength, effectively reduce problems such as debonding, and improve the reliability and stability of the product. ④ Excellent optical properties: Maintain high transmittance while maintaining low haze; ⑤ Good weather resistance: By adding functional additives such as allyl succinimidyl carbonate and antioxidants, the weather resistance is improved, the performance remains stable in harsh environments, it is not easy to age and yellow, and the service life is extended. It is suitable for optical applications in outdoor and complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] Figure 1 Schematic diagram of the structure of the optical OCA prepared by the present invention. DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0032] Example 1

[0033] This embodiment provides an optical OCA with high flexibility and high adhesion, which is prepared by the following steps:

[0034] S1. Raw material preparation and mixing: Add the acrylate prepolymer to the reaction vessel, turn on the stirring device, and stir at a speed of 500 r / min. Then, slowly add 0.5 parts of benzoin ether photoinitiator, 0.1 parts of butyl acrylate, 0.1 parts of γ-aminopropyltriethoxysilane and other additives in sequence. The stirring time is controlled within 60 minutes to ensure that all raw materials are fully mixed;

[0035] The acrylate prepolymer comprises 70 parts of isooctyl acrylate, 10 parts of lauryl methacrylate, 15 parts of isobornyl acrylate, 10 parts of acrylonitrile, 0.1 parts of a second photoinitiator, 0.03 parts of a molecular weight regulator, and 0.05 parts of a second cross-linking agent;

[0036] The other additives include 3 parts of allyl succinimidyl carbonate, 2 parts of hexafluorobisphenol A diacrylate, 4 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 4 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 7 parts of other polymerizable monomers, 25 parts of diluent, 0.75 parts of antioxidant and 0.75 parts of defoaming agent;

[0037] S2, polymerization process: transfer the mixed raw materials to the ultraviolet radiation equipment, and 2 Under the conditions of , irradiation for 10 minutes to initiate a polymerization reaction and form an OCA optical adhesive with preliminary properties; placing the OCA optical adhesive with preliminary properties in a reaction container, heating the reaction container to 80° C., and reacting at this temperature for 3 hours to promote the polymerization reaction of the raw materials to form the OCA optical adhesive;

[0038] S3. The prepared OCA optical adhesive is evenly coated on the release film using a precision coating device, with the coating thickness precisely controlled to be 150 μm. After coating, another layer of release film is covered and rolled to closely adhere the optical adhesive layer to the release film, and compacted to form an optical OCA with high flexibility and high adhesion.

[0039] The structure of the prepared optical OCA with high flexibility and high adhesion is as follows Figure 1 shown.

[0040] Example 2

[0041] Compared with Example 1, this embodiment differs in that the ratio of the acrylate prepolymer in S1 is changed, and the specific amount of the acrylate prepolymer is:

[0042] The acrylate prepolymer comprises 85 parts of isooctyl acrylate, 5 parts of lauryl methacrylate, 8 parts of isobornyl acrylate, 7 parts of acrylonitrile, 0.1 parts of a second photoinitiator, 0.03 parts of a molecular weight regulator, and 0.05 parts of a second cross-linking agent;

[0043] The remaining raw materials and preparation process remain the same as in Example 1.

[0044] Example 3

[0045] The difference between this embodiment and embodiment 1 is that the ratio of the acrylate prepolymer in S1 is changed, and the specific amount of the acrylate prepolymer is:

[0046] The acrylate prepolymer comprises 55 parts of isooctyl acrylate, 15 parts of lauryl methacrylate, 22 parts of isobornyl acrylate, 13 parts of acrylonitrile, 0.1 parts of a second photoinitiator, 0.03 parts of a molecular weight regulator, and 0.05 parts of a second cross-linking agent;

[0047] The remaining raw materials and preparation process remain the same as in Example 1.

[0048] Example 4

[0049] Compared with Example 1, this embodiment differs in that the amounts of the main photoinitiator, the reactive diluent, and the coupling agent in S1 are changed. The specific implementation steps of S1 are:

[0050] S1. Raw material preparation and mixing: Add the acrylate prepolymer to the reaction vessel, turn on the stirring device, and stir at a speed of 500 r / min. Then, slowly add 1 part of benzoin ether photoinitiator, 0.05 parts of butyl acrylate, 0.05 parts of γ-aminopropyltriethoxysilane and other additives in sequence. The stirring time is controlled within 60 minutes to ensure that all raw materials are fully mixed;

[0051] The remaining raw materials and preparation process remain the same as in Example 1.

[0052] Example 5

[0053] Compared with Example 1, this embodiment differs in that the amounts of the main photoinitiator, the reactive diluent, and the coupling agent in S1 are changed. The specific implementation steps of S1 are:

[0054] S1. Raw material preparation and mixing: Add the acrylate prepolymer to the reaction vessel, turn on the stirring device, and stir at a speed of 500 r / min. Then, slowly add 0.1 parts of benzoin ether photoinitiator, 0.2 parts of butyl acrylate, 0.2 parts of γ-aminopropyltriethoxysilane and other additives in sequence. The stirring time is controlled within 60 minutes to ensure that all raw materials are fully mixed;

[0055] The remaining raw materials and preparation process remain the same as in Example 1.

[0056] Example 6

[0057] The difference between this embodiment and embodiment 1 is that the amount of other additives in S1 is changed. The specific amount of other additives is:

[0058] The other additives include 4 parts of allyl succinimidyl carbonate, 3 parts of hexafluorobisphenol A diacrylate, 5 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 5 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 8 parts of other polymerizable monomers, 25 parts of diluent, 0.75 parts of antioxidant and 0.75 parts of defoaming agent;

[0059] The remaining raw materials and preparation process remain the same as in Example 1.

[0060] Example 7

[0061] Compared with Example 1, this embodiment differs in that the "benzoin ether initiator" is replaced by a "benzophenone photoinitiator". The specific implementation steps of S1 are:

[0062] S1. Raw material preparation and mixing: Add the acrylate prepolymer to the reaction vessel, turn on the stirring device, and stir at a speed of 500 r / min. Then, slowly add 0.5 parts of benzophenone photoinitiator, 0.1 parts of butyl acrylate, 0.1 parts of γ-aminopropyltriethoxysilane and other additives in sequence. The stirring time is controlled within 60 minutes to ensure that all raw materials are fully mixed;

[0063] The remaining raw materials and preparation process remain the same as in Example 1.

[0064] Example 8

[0065] Compared with Example 1, this embodiment differs in that "butyl acrylate" is replaced by "lauryl acrylate", and "γ-aminopropyltriethoxysilane" is replaced by "vinyltriethoxysilane". The specific implementation steps of S1 are:

[0066] S1. Raw material preparation and mixing: Add the acrylate prepolymer to the reaction vessel, turn on the stirring device, and stir at a speed of 500 r / min. Then, slowly add 0.5 parts of benzoin ether photoinitiator, 0.1 parts of lauryl acrylate, 0.1 parts of vinyl triethoxysilane and other additives in sequence. The stirring time is controlled within 60 minutes to ensure that all raw materials are fully mixed;

[0067] The remaining raw materials and preparation process remain the same as in Example 1.

[0068] Comparative Example 1

[0069] Compared with Example 1, this comparative example differs in that no other additives are added. The specific implementation steps of S1 are as follows:

[0070] S1. Raw material preparation and mixing: Add the acrylate prepolymer to the reaction vessel, turn on the stirring device, and stir at a speed of 500 r / min. Then, slowly add 0.5 parts of benzoin ether photoinitiator, 0.1 parts of butyl acrylate, and 0.1 parts of γ-aminopropyltriethoxysilane in sequence. The stirring time is controlled within 60 minutes to ensure that the raw materials are fully mixed.

[0071] The acrylate prepolymer comprises 70 parts of isooctyl acrylate, 10 parts of lauryl methacrylate, 15 parts of isobornyl acrylate, 10 parts of acrylonitrile, 0.1 parts of a second photoinitiator, 0.03 parts of a molecular weight regulator, and 0.05 parts of a second cross-linking agent;

[0072] The remaining raw materials and preparation process remain the same as in Example 1.

[0073] Comparative Example 2

[0074] This comparative example is different from Example 1 in that isooctyl acrylate is not added. The specific implementation steps of S1 are as follows:

[0075] S1. Raw material preparation and mixing: Add the acrylate prepolymer to the reaction vessel, turn on the stirring device, and stir at a speed of 500 r / min. Then, slowly add 0.5 parts of benzoin ether photoinitiator, 0.1 parts of butyl acrylate, 0.1 parts of γ-aminopropyltriethoxysilane and other additives in sequence. The stirring time is controlled within 60 minutes to ensure that all raw materials are fully mixed;

[0076] The acrylate prepolymer comprises 80 parts of lauryl methacrylate, 15 parts of isobornyl acrylate, 10 parts of acrylonitrile, 0.1 parts of a second photoinitiator, 0.03 parts of a molecular weight regulator, and 0.05 parts of a second cross-linking agent;

[0077] The other additives include 3 parts of allyl succinimidyl carbonate, 2 parts of hexafluorobisphenol A diacrylate, 4 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 4 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 7 parts of other polymerizable monomers, 25 parts of diluent, 0.75 parts of antioxidant and 0.75 parts of defoaming agent;

[0078] The remaining raw materials and preparation process remain the same as in Example 1.

[0079] Comparative Example 3

[0080] Compared with Example 1, this comparative example differs in that no silane coupling agent is added. The specific implementation steps of S1 are:

[0081] S1. Raw material preparation and mixing: Add the acrylate prepolymer to the reaction vessel, turn on the stirring device, and stir at a speed of 500 r / min. Then, slowly add 0.5 parts of benzoin ether photoinitiator, 0.1 parts of butyl acrylate, 0.1 parts of γ-aminopropyltriethoxysilane and other additives in sequence. The stirring time is controlled within 60 minutes to ensure that all raw materials are fully mixed;

[0082] The acrylate prepolymer comprises 70 parts of isooctyl acrylate, 10 parts of lauryl methacrylate, 15 parts of isobornyl acrylate, 10 parts of acrylonitrile, 0.1 parts of a second photoinitiator, 0.03 parts of a molecular weight regulator, and 0.05 parts of a second cross-linking agent;

[0083] The other additives include 3 parts of allyl succinimidyl carbonate, 2 parts of hexafluorobisphenol A diacrylate, 4 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 4 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 7 parts of other polymerizable monomers, 25 parts of diluent, 0.75 parts of antioxidant and 0.75 parts of defoaming agent;

[0084] The remaining raw materials and preparation process remain the same as in Example 1.

[0085] Performance testing

[0086] Post-processing and quality inspection: The formed OCA optical film is placed in an environment with a temperature of 60°C and a humidity of 60% for aging for 2 days to stabilize product performance.

[0087] Flexibility: According to GB / T1731-2020 "Determination of paint film flexibility", performance tests were carried out on Examples 1 to 8 and Comparative Examples 1 to 3. The pole pieces were wound and bent with an axial rod to observe whether the paint film had any damage such as reticulation, cracks, and peeling (no damage: excellent; slight damage: good; more damage: poor).

[0088] Adhesion: Glue the test sample to an adhesive steel plate and let it sit for 20 minutes. Tear off 10mm of the sample strip from the bottom of the steel plate upwards. Insert the bottom of the steel plate completely into the bottom of the slot of the tensile testing machine. Move the steel plate so that the sample strip and the adhesive strip overlap and align. Tighten the screws to fix the steel plate. Glue the torn 10mm strip completely overlapping the adhesive strip. Test the adhesion using a 180° peel force test speed of 300mm / min.

[0089] Light transmittance (%): The light transmittance of Examples 1 to 8 and Comparative Examples 1 to 3 was tested using a UV-vis spectrometer;

[0090] Haze (%): The haze of Examples 1 to 8 and Comparative Examples 1 to 3 was tested using a haze meter.

[0091] The results are shown in Table 1:

[0092] Table 1

[0093]

[0094]

[0095] As can be seen from Table 1, the only difference between Examples 2-8 and Example 1 is the raw material ratio and the change of the raw materials within a reasonable range. From the test results, the prepared optical OCAs all have good flexibility and adhesion, and the transmittance is greater than 99% and the haze is less than 1%.

[0096] Compared with Example 1, the main difference of Comparative Example 1 is that no other additives are added. Among the other additives, allyl succinimidyl carbonate has the effect of improving the stability of the material; compared with Example 1, the difference of Comparative Example 2 is isooctyl acrylate, and isooctyl acrylate can enhance the cohesion of the colloid and the wettability to the substrate due to its long carbon chain structure, and can significantly improve the flexibility and bending fatigue resistance of OCA, as shown by the decrease in flexibility and viscosity of Comparative Example 2; compared with Example 1, since the silane coupling agent can combine with the free radicals or functional groups of the acrylate system to achieve "molecular bridging" of the inorganic-organic interface, the long-term bonding stability of OCA is significantly improved in Comparative Example 3; compared with Example 1 and Example 8, it can be seen that isooctyl acrylate gives the colloid flexibility, but excessive plasticization may reduce the cohesive strength, and the silane coupling agent compensates for the loss of cohesive force through interfacial chemical bonding, making the OCA neither easy to crack nor easy to debond during repeated bending.

[0097] The above disclosures are only a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. An optical OCA with high flexibility and high adhesion, characterized in that: Calculated by weight, it includes acrylate prepolymer, 0.01-1.2 parts of primary photoinitiator, 0.05-0.2 parts of reactive diluent, 0.05-0.2 parts of coupling agent and other additives; The other additives include 2-4 parts of allyl succinimidyl carbonate, 1-3 parts of hexafluorobisphenol A diacrylate, 3-5 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 3-5 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 6-8 parts of other polymerizable monomers, 20-30 parts of diluent, 0.5-1 part of antioxidant and 0.5-1 part of defoaming agent.

2. The optical OCA with high flexibility and high adhesion according to claim 1, characterized in that: The acrylate prepolymer comprises, by weight, 55-85 parts of isooctyl acrylate, 5-15 parts of lauryl methacrylate, 8-22 parts of isobornyl acrylate, 5-15 parts of acrylonitrile, 0.02-0.2 parts of a second photoinitiator, 0.02-0.05 parts of a molecular weight regulator, and 0.01-0.1 parts of a second crosslinking agent.

3. The optical OCA with high flexibility and high adhesion according to claim 1, characterized in that: The main photoinitiator is one or a combination of benzoin ether and benzophenone photoinitiators.

4. The optical OCA with high flexibility and high adhesion according to claim 1, characterized in that: The active diluent is one or a combination of butyl acrylate, lauryl acrylate and isooctyl acrylate.

5. The optical OCA with high flexibility and high adhesion according to claim 1, characterized in that: The coupling agent is one or a combination of gamma-aminopropyltriethoxysilane, vinyltriethoxysilane and gamma-(methacryloyloxy)propyltrimethoxysilane.

6. A method for preparing an optical OCA with high flexibility and high adhesion according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Raw material preparation and mixing: Add the acrylate prepolymer into the reaction vessel and stir, then slowly add the photoinitiator, reactive diluent, coupling agent and other additives to ensure that all raw materials are fully mixed; S2. Polymerization process: transferring the uniformly mixed raw materials to an ultraviolet radiation device for radiation to initiate a polymerization reaction to form an OCA optical adhesive with preliminary properties; placing the OCA optical adhesive with preliminary properties in a reaction container for heating and reaction to generate the OCA optical adhesive; S3. The prepared OCA optical adhesive is evenly coated on the release film through precision coating equipment. After coating, it is covered with another layer of release film and the optical adhesive layer is tightly fitted to the release film by rolling and compacted into shape to obtain an optical OCA with high flexibility and high adhesion.

7. The method for preparing an optical OCA with high flexibility and high adhesion according to claim 6, wherein: The stirring speed is 200-500 r / min; and the stirring time is 30-60 min.

8. The method for preparing an optical OCA with high flexibility and high adhesion according to claim 6, wherein: The ultraviolet radiation intensity is 50-100 mW / cm 2 ; Radiation time is 5-15 minutes.

9. The method for preparing an optical OCA with high flexibility and high adhesion according to claim 6, wherein: The heating reaction is carried out by heating the temperature to 60-80° C. and reacting at this temperature for 2-4 hours.

10. The method for preparing an optical OCA with high flexibility and high adhesion according to claim 6, wherein: The optical OCA with high flexibility and high adhesion has a thickness of 25-250 μm.

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