Photothermal synergistically cured wide temperature range weather-resistant OCA adhesive film, preparation method and application thereof

Abstract

The application discloses a kind of photo-thermal synergic curing wide temperature range weather-resistant OCA adhesive film and preparation method and application thereof, OCA adhesive film includes PET release film and OCA glue coated on the surface of the PET release film, including the following components: hydroxyl-containing acrylate prepolymer, thio borate, metal porphyrin, long-chain compatibilizer, hydrolysis stabilizer, active diluent, photoinitiator, polymerization initiator, thermal activated crosslinking agent, tackifying resin and solvent;Hydroxyl-containing acrylate prepolymer is prepared by mixing hydroxyl acrylate monomer and lauric acid acrylate monomer;The polymerization initiator is azobisdimethylvaleronitrile, and the thermal activated crosslinking agent is benzoyl peroxide;The hydrolysis stabilizer is compounded by tetraethyl orthosilicate and silane coupling agent.The OCA adhesive film prepared by the application not only guarantees optical performance, but also realizes high bonding reliability, excellent weather resistance and long folding life of adhesive film under wide temperature range.It can be widely applied in optical adhesive technical field.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical adhesive, in particular to a light-heat synergistically cured wide-temperature-range weather-resistant OCA adhesive film and a preparation method and application thereof. BACKGROUND

[0002] With the development of display technology towards flexibility and foldability, foldable OLED screens have become the mainstream trend of terminal products such as smart phones and tablet computers due to their advantages of lightness, thinness and bendability. As a key bonding material in foldable screens, the performance of optical transparent adhesive (OCA) directly affects the optical effect, mechanical stability and service life of the display screen.

[0003] At present, a single curing method (such as only using ultraviolet curing or thermal curing) has been difficult to meet the preparation requirements of high-performance OCA adhesive films. Although ultraviolet curing has the advantages of fast curing speed and high efficiency, it has the problem of decreased bonding strength in high-temperature environments. The traditional thermal curing method may have the problems of slow curing speed and high energy consumption. At the same time, the existing technology generally uses ultraviolet absorbers to solve the yellowing problem of OCA adhesive films, but the system still yellow in high-temperature and high-humidity environments, and the weather resistance is insufficient. SUMMARY

[0004] In order to solve the problems existing in the prior art, the purpose of the present application is to provide a light-heat synergistically cured wide-temperature-range weather-resistant OCA adhesive film and a preparation method and application thereof. The prepared OCA adhesive film not only guarantees the optical performance, but also realizes high bonding reliability, excellent weather resistance and long folding life of the adhesive film in a wide temperature range.

[0005] To achieve the above-mentioned purpose, in a first aspect, an embodiment of the present application provides a light-heat synergistically cured wide-temperature-range weather-resistant OCA adhesive film, comprising a PET release film and an OCA adhesive coated on the surface of the PET release film, wherein the OCA adhesive comprises the following components by weight:

[0006] 100 parts of a hydroxyl-containing acrylate prepolymer, 0.8-1.2 parts of a thio borate, 0.2-0.4 parts of a metal porphyrin, 4-6 parts of a long-chain compatibilizer, 1.5-3.1 parts of a hydrolysis stabilizer, 2-4 parts of an active diluent, 1.0-2.0 parts of a photoinitiator, 0.3-0.9 parts of a polymerization initiator, 0.7-2.1 parts of a heat-activated crosslinking agent, 4-6 parts of an adhesion resin, and 40-50 parts of a solvent;

[0007] The hydroxyl-containing acrylate prepolymer is prepared by mixing a hydroxyl acrylate monomer and a lauryl acrylate monomer at a weight ratio of 7:3;

[0008] The polymerization initiator is azobisisobutyronitrile, and the heat-activated crosslinking agent is benzoyl peroxide;

[0009] The hydrolysis stabilizer is tetraethyl orthosilicate 1.0-2.0 parts and silane coupling agent 0.5-1.1 parts.

[0010] Preferably, a layer of the OCA adhesive is coated between the two layers of PET release film, and is subjected to ultraviolet curing at 40℃ or below, using a 365nm ultraviolet lamp at an energy of 80-120mJ / cm² to form a surface crosslinking layer; and then is subjected to segmented thermal crosslinking curing in an oven, the first stage being curing at 80-85℃ for 5-8min, and the second stage being curing at 115-120℃ for 10-15min.

[0011] Preferably, the thioborate is dimethyl methylthioborate or diethyl ethylthioborate.

[0012] Preferably, the metalloporphyrin is a porphyrin derivative in which the metal ion is or Preferably, the metalloporphyrin is a porphyrin derivative in which the metal ion is

[0013] Preferably, the long-chain compatibilizer is an acrylate compound with a carbon chain length of 8-18, including lauryl acrylate, oleic acid acrylate or stearic acid acrylate.

[0014] Preferably, the photoinitiator is 2-hydroxy-2-methylpropiophenone.

[0015] Preferably, the silane coupling agent is methacryloyloxypropyltrimethoxysilane or aminopropyltrimethoxysilane; and the reactive diluent is one of 1,6-hexanediol diacrylate, ethylene glycol diacrylate or dipropylene glycol diacrylate.

[0016] Preferably, the tackifying resin is hydrogenated rosin glyceride, and the solvent is a mixture of ethyl acetate and butanone in a weight ratio of 3:1.

[0017] The wide-temperature-range weather-resistant OCA adhesive film provided by the present application is characterized by the ingenious combination and synergistic effect of a hydroxyl-containing acrylate prepolymer, a TB-MP weather-resistant system (including a thioborate, a metalloporphyrin, a long-chain compatibilizer and a hydrolysis stabilizer) and a light-heat dual curing mechanism, thereby achieving high bonding reliability, excellent weather resistance and long folding life of the adhesive film in a wide temperature range.

[0018] The hydroxyl-containing acrylate prepolymer is the base resin of the OCA adhesive and is prepared by free radical copolymerization, and its core role is to provide the adhesive film with basic bonding properties, flexibility and reactive sites; the long-chain structure of the prepolymer matches the long-chain compatibilizer and the hydrophobic group of the thioborate in the TB-MP weather-resistant system, thereby avoiding performance degradation caused by phase separation and ensuring the uniformity of the OCA adhesive film.

[0019] The TB-MP weather-resistant system is composed of thio borate ester, metal porphyrin, long-chain compatibilizer and hydrolysis stabilizer, the thio borate ester captures peroxide, the metal porphyrin quenches free radicals, and the hydrolysis stabilizer constructs an anti-permeation barrier, so that the degradation reaction caused by light, heat and water is inhibited in a synergistic manner, an oxidation-resistant, free radical-resistant and hydrolysis-resistant composite weather-resistant system is formed, and the yellowing resistance of the OCA adhesive film in a high-temperature and high-humidity environment is significantly improved.

[0020] To realize the wide-temperature-range bonding stability, the present application adopts photo-thermal synergistic curing, and through rapid surface drying by ultraviolet light and deep layer curing by thermal crosslinking, the production efficiency and performance requirements are taken into account. The ultraviolet light cures the surface of the glue solution, prevents sticking after coating, and is suitable for industrial continuous coating. The thermal crosslinking deep layer curing solves the problem of strength reduction at high temperature caused by incomplete ultraviolet crosslinking. In the first stage, the polymeric initiator is activated at low temperature to cause slight crosslinking of the prepolymer and form a preliminary network structure. In the second stage, the thermal activation crosslinking agent releases free radicals to cause deep esterification crosslinking of the hydroxyl and acrylate groups. The thermal crosslinking curing realizes gradient crosslinking structure through double decomposition temperature, and improves the bonding stability and weather resistance.

[0021] In the second aspect, the present application provides a preparation method of the above-mentioned photo-thermal synergistic curing wide-temperature-range weather-resistant OCA adhesive film, comprising the following steps:

[0022] S1, preparation of a hydroxyl-containing acrylate prepolymer:

[0023] The hydroxyl-containing acrylate prepolymer is prepared by adding hydroxyethyl acrylate and lauryl acrylate into a reaction kettle, adding an initiator, and reacting at 60-80 DEG C for 3-4 h under nitrogen protection.

[0024] S2, preparation of a silane pre-hydrolysis solution:

[0025] The silane pre-hydrolysis solution is prepared by mixing tetraethyl orthosilicate and silane coupling agent, adding glacial acetic acid and deionized water, and stirring at room temperature until transparent.

[0026] S3, preparation of an OCA glue solution:

[0027] The OCA glue solution is prepared by adding the hydroxyl-containing acrylate prepolymer prepared in step S1, the long-chain compatibilizer, the silane pre-hydrolysis solution prepared in step S2, the thio borate ester, the metal porphyrin, the active diluent, the tackifying resin, the solvent, the photoinitiator and the thermal activation crosslinking agent in sequence according to the formula, and high-speed dispersion to obtain a uniform OCA glue solution.

[0028] S4, preparation of an OCA adhesive film:

[0029] A surface cross-linking layer is formed by coating the OCA glue solution prepared in step S3 between two layers of PET release film, and performing ultraviolet curing at 40 DEG C or below using a 365 nm ultraviolet lamp at an energy of 80-120 mJ / cm2; and then performing segmented thermal cross-linking curing in an oven, with the first stage being curing at 80-85 DEG C for 5-8 min and the second stage being curing at 115-120 DEG C for 10-15 min.

[0030] In the present application, the preparation of the hydroxyl-containing acrylate prepolymer introduces lauric acid acrylate into the side chain of the prepolymer by copolymerization, and the long-chain alkyl group can increase the flexibility of the adhesive film at low temperature, avoiding brittle fracture due to excessive rigidity when folding; at the same time, the long-chain alkyl side group of the prepolymer matches the structure of the long-chain compatibilizer and the hydrophobic group of the thioborate in the TB-MP system, and can reduce the phase separation of each component by intermolecular entanglement, ensuring the uniformity of the adhesive film.

[0031] The preparation of the silane pre-hydrolysis solution converts the hydrolysis stabilizer into a reactive form, and the partial hydrolysis of tetraethyl orthosilicate and silane coupling agent occurs under the catalysis of glacial acetic acid to generate a transparent pre-hydrolysis solution containing silanol groups, which react with the hydroxyl groups of the prepolymer and the boron-oxygen bond of the thioborate to form a hydrolysis-resistant network, blocking the penetration of water molecules and effectively improving the weather resistance of the OCA adhesive film.

[0032] In a third aspect, the present application provides the use of the above-mentioned photo-thermal synergistically cured wide-temperature-range weather-resistant OCA adhesive film in the preparation of a foldable screen.

[0033] The present application has the following beneficial effects:

[0034] The photo-thermal synergistically cured wide-temperature-range weather-resistant OCA adhesive film provided by the present application realizes high bonding reliability and excellent weather resistance of the adhesive film in a wide temperature range through the ingenious combination and synergistic effect of the hydroxyl-containing acrylate prepolymer, the TB-MP weather-resistant system (including: thioborate, metal porphyrin, long-chain compatibilizer and hydrolysis stabilizer) and the photo-thermal dual curing mechanism. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0036] The present application provides a photo-thermal synergistically cured wide-temperature-range weather-resistant OCA adhesive film, comprising a PET release film and an OCA adhesive coated on the surface of the PET release film, wherein the OCA adhesive comprises the following components by weight:

[0037] The composition includes 100 parts of hydroxyl-containing acrylate prepolymer, 0.8-1.2 parts of thioboronate, 0.2-0.4 parts of metalloporphyrin, 4-6 parts of long-chain compatibilizer, 1.5-3.1 parts of hydrolysis stabilizer, 2-4 parts of reactive diluent, 1.0-2.0 parts of photoinitiator, 0.3-0.9 parts of polymerization initiator, 0.7-2.1 parts of thermally activated crosslinking agent, 4-6 parts of tackifying resin, and 40-50 parts of solvent.

[0038] The hydroxyl-containing acrylate prepolymer is prepared by mixing hydroxyl acrylate monomer and lauric acid acrylate monomer in a weight ratio of 7:3.

[0039] The polymerization initiator is azobisisobutyronitrile, and the thermally activated crosslinking agent is benzoyl peroxide;

[0040] The hydrolysis stabilizer is a compound of 1.0-2.0 parts of tetraethyl orthosilicate and 0.5-1.1 parts of silane coupling agent.

[0041] Preferably, a layer of the OCA adhesive is applied between two PET release films, and ultraviolet light is used at a temperature below 40°C with a 365nm UV lamp and an energy of 80-120mJ / cm² to form a surface crosslinking layer; subsequently, segmented thermal crosslinking curing is performed in an oven, with the first stage being curing at 80-85°C for 5-8 minutes and the second stage being curing at 115-120°C for 10-15 minutes.

[0042] Preferably, the thioboronic ester is dimethyl methyl thioboronate or diethyl ethyl thioboronate.

[0043] Preferably, the metalloporphyrin is a metal ion. or Porphyrin derivatives.

[0044] Preferably, the long-chain compatibilizer is an acrylate compound with a carbon chain length of 8-18, including laurate acrylate, oleate acrylate, or stearate acrylate.

[0045] Preferably, the photoinitiator is 2-hydroxy-2-methylphenylacetone.

[0046] Preferably, the silane coupling agent is methacryloyloxypropyltrimethoxysilane or aminopropyltrimethoxysilane; the reactive diluent is one of 1,6-hexanediol diacrylate, ethylene glycol diacrylate or dipropylene glycol diacrylate.

[0047] Preferably, the tackifying resin is hydrogenated rosin glycerol ester, and the solvent is a mixture of ethyl acetate and butanone in a 3:1 weight ratio.

[0048] To illustrate the superior effects of the present invention, the following embodiments and comparative examples are provided.

[0049] The raw materials used in the following examples and comparative examples of the present application can be purchased from the market, and their sources are not specifically limited.

[0050] The following raw material sources are exemplary:

[0051] Hydroxyethyl acrylate, Shanghai Aladdin Bio-Chem Technology Co., Ltd., A102083;

[0052] Lauryl acrylate, Shanghai Macklin Biochemical Technology Co., Ltd., L808657;

[0053] Dimethyl methylthioboronic acid, Dow Chemical (China) Investment Co., Ltd., DOW-THB-001;

[0054] Co²+ porphyrin derivative, Shanghai Yuan Ye Biotechnology Co., Ltd., S28648;

[0055] Zn²+ porphyrin derivative, Sigma-Aldrich, Z836208;

[0056] Stearyl acrylate, Shanghai Macklin Biochemical Technology Co., Ltd., S822674;

[0057] Tetraethyl orthosilicate, National Pharmaceutical Group Chemical Reagent Co., Ltd., T2001;

[0058] Methacryloyloxypropyl trimethoxysilane, Shin-Etsu Chemical Co., Ltd., KBM-503;

[0059] Azobisisobutyronitrile, Shanghai Macklin Biochemical Technology Co., Ltd., A800974;

[0060] 1,6-hexanediol diacrylate, San Chemical Technology (Shanghai) Co., Ltd., SR238;

[0061] Hydrogenated rosin glyceride, Arakawa Chemical Industries, Ltd., KE-604;

[0062] Ethyl acetate, National Pharmaceutical Group Chemical Reagent Co., Ltd., E1002;

[0063] Butanone, National Pharmaceutical Group Chemical Reagent Co., Ltd., M1003;

[0064] 2-Hydroxy-2-methylpropiophenone, BASF (China) Co., Ltd., Irgacure 1173;

[0065] Benzoyl peroxide, Shanghai Aladdin Bio-Chem Technology Co., Ltd., B105666;

[0066] PET release film, Toray (China) Investment Co., Ltd.

[0067] Example:

[0068] Example 1

[0069] 1. Raw material formulation (by weight)

[0070] Hydroxyl-containing acrylate prepolymer 100 parts (hydroxyethyl acrylate and lauryl acrylate in a weight ratio of 7:3), dimethyl methylthioboronic acid 1.0 part, porphyrin derivative 0.3 part, acrylic acid laurate 5 parts, hydrolysis stabilizer 2.3 parts (tetraethyl orthosilicate 1.5 parts + methacryloyloxypropyl trimethoxysilane 0.8 parts), dipropylene glycol diacrylate 3 parts, 2-hydroxy-2-methylpropiophenone 1.5 parts, azobisisobutyronitrile 0.6 part, benzoyl peroxide 1.4 parts, hydrogenated rosin glyceride 5 parts, solvent 45 parts (ethyl acetate: butanone = 3:1).

[0071] 2. Preparation steps

[0072] S1: Preparation of hydroxyl-containing acrylate prepolymer: 70 parts of hydroxyethyl acrylate and 30 parts of lauryl acrylate were added to a reaction kettle, and 0.6 parts of azobisisobutyronitrile was added. Under nitrogen protection, the rotation speed was 300 rpm at 70°C, and the reaction was carried out for 3.5 hours to obtain the hydroxyl-containing acrylate prepolymer.

[0073] S2: Preparation of silane pre-hydrolysis solution: 1.5 parts of tetraethyl orthosilicate and 0.8 parts of methacryloyloxypropyl trimethoxysilane were mixed, a small amount of glacial acetic acid and deionized water were added, and magnetic stirring was carried out at room temperature for 30 minutes until it became transparent to obtain the silane pre-hydrolysis solution.

[0074] S3: Preparation of OCA glue solution: according to the formulation, the hydroxyl-containing acrylate prepolymer prepared in S1, acrylic acid laurate, the silane pre-hydrolysis solution prepared in S2, dimethyl methylthioboronic acid, porphyrin derivative, dipropylene glycol diacrylate, hydrogenated rosin glyceride, and solvent were added in sequence, and first stirred at low speed (500 rpm) for 10 minutes until the solids were completely dissolved, then 2-hydroxy-2-methylpropiophenone and benzoyl peroxide were added, the rotation speed was adjusted to 3000 rpm, and high-speed dispersion was carried out for 30 minutes to obtain a uniform OCA glue solution.

[0075] S4: Preparation of OCA glue film: a layer of OCA glue solution prepared in S3 was coated between two layers of Toray PET release film, and was subjected to ultraviolet light curing at an energy of 100 mJ / cm² using a 365 nm ultraviolet lamp below 40°C to form a surface crosslinking layer; then it was subjected to segmented thermal crosslinking curing in an oven, with the first stage being 82°C for 6 minutes and the second stage being 118°C for 12 minutes.

[0076] Example 2

[0077] 1. Raw material formulation (by weight)

[0078] Hydroxyl-containing acrylate prepolymer 100 parts (hydroxyethyl acrylate and lauryl acrylate in a weight ratio of 7:3), diethyl ethylthioborate 1.2 parts, Porphyrin derivative 0.4 parts, lauryl acrylate 6 parts, hydrolysis stabilizer 3.1 parts (tetraethyl orthosilicate 2.0 parts + aminopropyl trimethoxysilane 1.1 parts), ethylene glycol diacrylate 4 parts, 2-hydroxy-2-methylpropiophenone 2.0 parts, azobisisobutyronitrile 0.9 parts, benzoyl peroxide 2.1 parts, hydrogenated rosin glyceride 6 parts, solvent 50 parts (ethyl acetate: butanone = 3:1).

[0079] 2. Preparation steps

[0080] S1: Hydroxyl-containing acrylate prepolymer preparation: 70 parts of hydroxyethyl acrylate and 30 parts of lauryl acrylate were added to a reaction kettle, 0.9 parts of azobisisobutyronitrile was added, and the reaction was carried out at 80°C with a rotation speed of 300 rpm for 3 hours under nitrogen protection to prepare the hydroxyl-containing acrylate prepolymer.

[0081] S2: Preparation of silane pre-hydrolysis solution: 2.0 parts of tetraethyl orthosilicate and 1.1 parts of aminopropyl trimethoxysilane were mixed, a small amount of glacial acetic acid and deionized water were added, and magnetic stirring was carried out at room temperature for 30 minutes until it became transparent to prepare the silane pre-hydrolysis solution.

[0082] S3: OCA glue solution preparation: according to the formulation, the hydroxyl-containing acrylate prepolymer prepared in S1, lauryl acrylate, the silane pre-hydrolysis solution prepared in S2, diethyl ethylthioborate, porphyrin derivative, ethylene glycol diacrylate, hydrogenated rosin glyceride, and solvent were added in sequence, first low-speed stirring (500 rpm) for 10 minutes until the solids were completely dissolved, then 2-hydroxy-2-methylpropiophenone and benzoyl peroxide were added, the rotation speed was adjusted to 3000 rpm, and high-speed dispersion was carried out for 30 minutes to obtain a uniform OCA glue solution.

[0083] S4: OCA glue film preparation: a layer of OCA glue solution prepared in S3 was coated between two layers of Toray PET release film, and was subjected to ultraviolet light curing at an energy of 120 mJ / cm² using a 365 nm ultraviolet lamp below 40°C to form a surface crosslinking layer; then it was subjected to segmented thermal crosslinking curing in an oven, the first stage was 85°C for 5 minutes, and the second stage was 120°C for 10 minutes.

[0084] Example 3

[0085] 1. Raw material formulation (by weight)

[0086] Hydroxyl-containing acrylate prepolymer 100 parts (hydroxyethyl acrylate and lauryl acrylate in a weight ratio of 7:3), dimethyl methylthioboronic acid 0.8 parts, Porphyrin derivative 0.2 parts, stearyl acrylate 4 parts, hydrolysis stabilizer 1.5 parts (tetraethyl orthosilicate 1.0 part + methacryloyloxypropyl trimethoxysilane 0.5 part), 1,6-hexanediol diacrylate 2 parts, 2-hydroxy-2-methylpropiophenone 1.0 part, azobisisobutyronitrile 0.3 parts, benzoyl peroxide 0.7 parts, hydrogenated rosin glyceride 4 parts, solvent 40 parts (ethyl acetate: butanone = 3:1).

[0087] 2. Preparation step

[0088] S1: Preparation of hydroxyl-containing acrylate prepolymer: 70 parts of hydroxyethyl acrylate and 30 parts of lauryl acrylate were added to a reaction kettle, 0.3 parts of azobisisobutyronitrile was added, and the reaction was carried out at 60°C with a rotation speed of 300 rpm for 4 hours under nitrogen protection. After cooling to room temperature, the hydroxyl-containing acrylate prepolymer was prepared.

[0089] S2: Preparation of silane pre-hydrolysis solution: 1.0 parts of tetraethyl orthosilicate and 0.5 parts of methacryloyloxypropyl trimethoxysilane were mixed, a small amount of glacial acetic acid and deionized water were added, and magnetic stirring was carried out at room temperature for 30 minutes until it became transparent. The silane pre-hydrolysis solution was prepared.

[0090] S3: Preparation of OCA glue solution: the hydroxyl-containing acrylate prepolymer prepared in S1, stearyl acrylate, the silane pre-hydrolysis solution prepared in S2, dimethyl methylthioboronic acid, porphyrin derivative, 1,6-hexanediol diacrylate, hydrogenated rosin glyceride, and solvent were added in sequence according to the formula, and low-speed stirring (500 rpm) was carried out for 10 minutes until the solids were completely dissolved. Then 2-hydroxy-2-methylpropiophenone and benzoyl peroxide were added, the rotation speed was adjusted to 3000 rpm, and high-speed dispersion was carried out for 30 minutes. The uniform OCA glue solution was obtained by filtration.

[0091] S4: Preparation of OCA glue film: a layer of OCA glue solution prepared in S3 was coated between two layers of Toray PET release film, and ultraviolet light curing was carried out at 40°C or below using a 365 nm ultraviolet lamp with an energy of 80 mJ / cm² to form a surface crosslinking layer. Then, stepwise thermal crosslinking and curing were carried out in an oven, with the first stage being 80°C for 8 minutes and the second stage being 115°C for 15 minutes.

[0092] Example 4

[0093] 1. Raw material formula (by weight)

[0094] Hydroxyl-containing acrylate prepolymer 100 parts (hydroxyethyl acrylate and lauryl acrylate in a weight ratio of 7:3), dimethyl methylthioboronic acid 0.8 parts, Porphyrin derivative 0.25 parts, stearyl acrylate 5 parts, hydrolysis stabilizer 1.8 parts (tetraethyl orthosilicate 1.2 parts + aminopropyl trimethoxysilane 0.6 parts), 1,6-hexanediol diacrylate 2.5 parts, 2-hydroxy-2-methylpropiophenone 1.2 parts, azobisisobutyronitrile 0.4 parts, benzoyl peroxide 1.0 part, hydrogenated rosin glyceride 4.5 parts, solvent 42 parts (ethyl acetate: butanone = 3:1).

[0095] 2. Preparation step

[0096] S1: Preparation of hydroxyl-containing acrylate prepolymer: 70 parts of hydroxyethyl acrylate and 30 parts of lauryl acrylate were added to a reaction kettle, 0.4 parts of azobisisobutyronitrile was added, and the reaction was carried out at 65°C with a rotation speed of 300 rpm for 3.8 hours under nitrogen protection to obtain the hydroxyl-containing acrylate prepolymer.

[0097] S2: Preparation of silane pre-hydrolysis solution: 1.2 parts of tetraethyl orthosilicate and 0.6 parts of aminopropyl trimethoxysilane were mixed, a small amount of glacial acetic acid and deionized water were added, and the mixture was stirred magnetically at room temperature for 30 minutes until it became transparent to obtain the silane pre-hydrolysis solution.

[0098] S3: Preparation of OCA glue solution: the hydroxyl-containing acrylate prepolymer prepared in S1, stearyl acrylate, the silane pre-hydrolysis solution prepared in S2, ethylthioborate diethyl ester, porphyrin derivative, 1,6-hexanediol diacrylate, hydrogenated rosin glyceride, and solvent were added in sequence according to the formula, and stirred at low speed (500 rpm) for 10 minutes until the solids were completely dissolved. Then 2-hydroxy-2-methylpropiophenone and benzoyl peroxide were added, and the rotation speed was adjusted to 3000 rpm for high-speed dispersion for 30 minutes. The uniform OCA glue solution was obtained by filtration.

[0099] S4: Preparation of OCA glue film: a layer of OCA glue solution prepared in S3 was coated between two layers of Toray PET release film, and was subjected to ultraviolet curing at an energy of 90 mJ / cm² using a 365 nm ultraviolet lamp below 40°C to form a surface cross-linking layer. Then it was subjected to segmented thermal cross-linking curing in an oven, with the first stage being curing at 81°C for 7 minutes and the second stage being curing at 116°C for 13 minutes.

[0100] Example 5

[0101] 1. Raw material formula (by weight)

[0102] hydroxyl-containing acrylate prepolymer 100 parts (hydroxyethyl acrylate and lauryl acrylate in a weight ratio of 7:3), dimethyl methylthioborate 1.1 parts, Porphyrin derivative 0.35 parts, lauryl acrylate 4.5 parts, hydrolysis stabilizer 2.8 parts (tetraethyl orthosilicate 1.8 parts + methyl methacryloyloxypropyl trimethoxysilane 1.0 part), ethylene glycol diacrylate 3.5 parts, 2-hydroxy-2-methylpropiophenone 1.8 parts, azobisisobutyronitrile 0.8 parts, benzoyl peroxide 1.8 parts, hydrogenated rosin glyceride 5.5 parts, solvent 48 parts (ethyl acetate: butanone = 3:1).

[0103] 2. Preparation step

[0104] S1: Preparation of hydroxyl-containing acrylate prepolymer: 70 parts of hydroxyethyl acrylate and 30 parts of lauryl acrylate are added to a reaction kettle, and 0.8 parts of azobisisobutyronitrile is added. Under nitrogen protection, the rotation speed is 300 rpm at 75°C, and the reaction is carried out for 3.2 hours to obtain the hydroxyl-containing acrylate prepolymer.

[0105] S2: Preparation of silane pre-hydrolysis solution: 1.8 parts of tetraethyl orthosilicate and 1.0 part of methyl methacryloyloxypropyl trimethoxysilane are mixed, a small amount of glacial acetic acid and deionized water are added, and magnetic stirring is carried out at room temperature for 30 minutes until it becomes transparent to obtain the silane pre-hydrolysis solution.

[0106] S3: Preparation of OCA glue solution: the hydroxyl-containing acrylate prepolymer prepared in S1, lauryl acrylate, the silane pre-hydrolysis solution prepared in S2, methylthioboronic acid dimethyl ester, porphyrin derivative, ethylene glycol diacrylate, hydrogenated rosin glyceride, and solvent are added in sequence according to the formula, and low-speed stirring (500 rpm) is carried out for 10 minutes until the solids are completely dissolved. Then 2-hydroxy-2-methylpropiophenone and benzoyl peroxide are added, the rotation speed is adjusted to 3000 rpm, and high-speed dispersion is carried out for 30 minutes to obtain a uniform OCA glue solution.

[0107] S4: Preparation of OCA glue film: a layer of OCA glue solution prepared in S3 is coated between two layers of Toray PET release film, and ultraviolet light curing is carried out at an energy of 110 mJ / cm² using a 365 nm ultraviolet lamp below 40°C to form a surface crosslinking layer. Then, stepwise thermal crosslinking curing is carried out in an oven, with the first stage being curing at 84°C for 6 minutes and the second stage being curing at 119°C for 11 minutes.

[0108] Example 6

[0109] 1. Raw material formula (by weight)

[0110] hydroxyl-containing acrylate prepolymer 100 parts (hydroxyethyl acrylate and lauryl acrylate in a weight ratio of 7:3), ethylthioboronic acid diethyl ester 1.0 part, Porphyrin derivative 0.3 parts, oleic acid acrylate 5.5 parts, hydrolysis stabilizer 2.0 parts (tetraethyl orthosilicate 1.3 parts + aminopropyl trimethoxysilane 0.7 parts), dipropylene glycol diacrylate 3 parts, 2-hydroxy-2-methylpropiophenone 1.6 parts, azobisisobutyronitrile 0.7 parts, benzoyl peroxide 1.5 parts, hydrogenated rosin glyceride 5 parts, solvent 46 parts (ethyl acetate: butanone = 3:1).

[0111] 2. Preparation step

[0112] S1: Preparation of hydroxyl-containing acrylate prepolymer: 70 parts of hydroxyethyl acrylate and 30 parts of lauryl acrylate are added to a reaction kettle, 0.7 parts of azobisisobutyronitrile is added, and under nitrogen protection, the rotation speed is 300 rpm at 68°C, and the reaction is carried out for 3.6 hours to obtain the hydroxyl-containing acrylate prepolymer.

[0113] S2: Preparation of silane pre-hydrolysis solution: 1.3 parts of tetraethyl orthosilicate and 0.7 parts of aminopropyl trimethoxysilane are mixed, a small amount of glacial acetic acid and deionized water are added, and magnetic stirring is carried out at room temperature for 30 minutes until it becomes transparent to obtain the silane pre-hydrolysis solution.

[0114] S3: Preparation of OCA glue solution: the hydroxyl-containing acrylate prepolymer prepared in S1, oleic acid acrylate, the silane pre-hydrolysis solution prepared in S2, ethyl thio borate diethyl ester, porphyrin derivative, dipropylene glycol diacrylate, hydrogenated rosin glyceride, and solvent are added in sequence according to the formula, and low-speed stirring (500 rpm) is carried out for 10 minutes until the solids are completely dissolved, then 2-hydroxy-2-methylpropiophenone and benzoyl peroxide are added, the rotation speed is adjusted to 3000 rpm, and high-speed dispersion is carried out for 30 minutes to obtain a uniform OCA glue solution.

[0115] S4: Preparation of OCA glue film: a layer of OCA glue solution prepared in S3 is coated between two layers of Toray PET release film, and ultraviolet light curing is carried out at an energy of 105 mJ / cm² using a 365 nm ultraviolet lamp below 40°C to form a surface crosslinking layer; then, segmented thermal crosslinking curing is carried out in an oven, the first stage is curing at 83°C for 7 minutes, and the second stage is curing at 117°C for 12 minutes.

[0116] Example 7

[0117] 1. Raw material formula (by weight)

[0118] hydroxyl-containing acrylate prepolymer 100 parts (hydroxyethyl acrylate and lauryl acrylate in a weight ratio of 7:3), dimethyl methylthioboronic acid 0.85 parts, Porphyrin derivative 0.22 parts, stearyl acrylate 4.2 parts, hydrolysis stabilizer 1.6 parts (tetraethyl orthosilicate 1.1 part + methacryloyloxypropyl trimethoxysilane 0.5 part), 1,6-hexanediol diacrylate 2.2 parts, 2-hydroxy-2-methylpropiophenone 1.1 part, azobisisobutyronitrile 0.35 part, benzoyl peroxide 0.8 part, hydrogenated rosin glyceride 4.2 parts, solvent 41 parts (ethyl acetate: butanone = 3:1).

[0119] 2. Preparation step

[0120] S1: Preparation of hydroxyl-containing acrylate prepolymer: 70 parts of hydroxyethyl acrylate and 30 parts of lauryl acrylate are added to a reaction kettle, and 0.35 parts of azobisisobutyronitrile is added. Under nitrogen protection, the rotation speed is 300 rpm at 62°C, and the reaction is carried out for 3.9 hours to obtain the hydroxyl-containing acrylate prepolymer.

[0121] S2: Preparation of silane pre-hydrolysis solution: 1.1 parts of tetraethyl orthosilicate and 0.5 parts of methacryloyloxypropyl trimethoxysilane are mixed, a small amount of glacial acetic acid and deionized water are added, and magnetic stirring is carried out at room temperature for 30 minutes until it becomes transparent to obtain the silane pre-hydrolysis solution.

[0122] S3: Preparation of OCA glue solution: the hydroxyl-containing acrylate prepolymer prepared in S1, stearyl acrylate, the silane pre-hydrolysis solution prepared in S2, methylthioboronic acid dimethyl ester, porphyrin derivative, 1,6-hexanediol diacrylate, hydrogenated rosin glyceride, and solvent are added in sequence according to the formula, and low-speed stirring (500 rpm) is carried out for 10 minutes until the solids are completely dissolved. Then 2-hydroxy-2-methylpropiophenone and benzoyl peroxide are added, the rotation speed is adjusted to 3000 rpm, and high-speed dispersion is carried out for 30 minutes to obtain a uniform OCA glue solution.

[0123] S4: Preparation of OCA glue film: a layer of OCA glue solution prepared in S3 is coated between two layers of Toray PET release film, and ultraviolet light curing is carried out at 40°C or below using a 365 nm ultraviolet lamp at an energy of 85 mJ / cm² to form a surface cross-linking layer. Then, step-by-step thermal cross-linking and curing are carried out in an oven, with the first stage being 80°C for 7.5 minutes and the second stage being 115°C for 14 minutes.

[0124] Example 8

[0125] 1. Raw material formula (by weight)

[0126] hydroxyl-containing acrylate prepolymer 100 parts (hydroxyethyl acrylate and lauryl acrylate in a weight ratio of 7:3), ethylthioboronic acid diethyl ester 1.15 parts, Porphyrin derivative 0.38 parts, lauryl acrylate 5.8 parts, hydrolysis stabilizer 3.0 parts (tetraethyl orthosilicate 1.9 parts + aminopropyl trimethoxysilane 1.1 parts), ethylene glycol diacrylate 3.8 parts, 2-hydroxy-2-methylpropiophenone 1.9 parts, azobisisobutyronitrile 0.85 parts, benzoyl peroxide 2.0 parts, hydrogenated rosin glyceride 5.8 parts, solvent 49 parts (ethyl acetate: butanone = 3:1).

[0127] 2. Preparation step

[0128] S1: Preparation of hydroxyl-containing acrylate prepolymer: 70 parts of hydroxyethyl acrylate and 30 parts of lauryl acrylate are added to a reaction kettle, 0.85 parts of azobisisobutyronitrile is added, and the reaction is carried out at 78°C under nitrogen protection at a speed of 300 rpm for 3.1 hours to obtain a hydroxyl-containing acrylate prepolymer.

[0129] S2: Preparation of silane pre-hydrolysis solution: 1.9 parts of tetraethyl orthosilicate and 1.1 parts of aminopropyl trimethoxysilane are mixed, a small amount of glacial acetic acid and deionized water are added, and the mixture is stirred magnetically at room temperature for 30 minutes until it becomes transparent to obtain a silane pre-hydrolysis solution.

[0130] S3: Preparation of OCA glue solution: the hydroxyl-containing acrylate prepolymer prepared in S1, lauryl acrylate, the silane pre-hydrolysis solution prepared in S2, methylthioboronic acid dimethyl ester, porphyrin derivative, 1,6-hexanediol diacrylate, hydrogenated rosin glyceride, solvent, are added in sequence according to the formula, first stirred at low speed (500 rpm) for 10 minutes until the solids are completely dissolved, then 2-hydroxy-2-methylpropiophenone and benzoyl peroxide are added, the speed is adjusted to 3000 rpm, and high-speed dispersion is carried out for 30 minutes to obtain a uniform OCA glue solution.

[0131] S4: Preparation of OCA glue film: a layer of OCA glue solution prepared in S3 is coated between two layers of Toray PET release film, and is subjected to ultraviolet curing at an energy of 80 mJ / cm² using a 365 nm ultraviolet lamp below 40°C to form a surface crosslinking layer; then it is subjected to segmented thermal crosslinking curing in an oven, with the first stage being curing at 80°C for 8 minutes and the second stage being curing at 115°C for 15 minutes.

[0132] Comparative example:

[0133] Comparative example 1

[0134] Except that it does not contain thio borate ester, metal porphyrin, long-chain compatibilizer and hydrolysis stabilizer, the rest is the same as example 1.

[0135] Comparative example 2

[0136] Example 1 except that equal weight of commercially available UV absorber UV-531 (BASF) was used instead of thio boronate ester, metallo porphyrin, long chain compatibilizer and hydrolytic stabilizer.

[0137] Comparative Example 3

[0138] Example 1 except that equal weight of ethyl acrylate was used instead of long chain compatibilizer.

[0139] Comparative Example 4

[0140] Example 1 except that equal weight of styrene acrylate was used instead of long chain compatibilizer.

[0141] Comparative Example 5

[0142] Example 1 except that it did not contain hydrolytic stabilizer.

[0143] Comparative Example 6

[0144] Example 1 except that equal weight of ethyl orthosilicate was used instead of tetraethyl orthosilicate.

[0145] Comparative Example 7

[0146] Example 1 except that equal weight of silane coupling agent was used instead of tetraethyl orthosilicate.

[0147] Comparative Example 8

[0148] Example 1 except that equal weight of methyl mercaptopropionate was used instead of dimethyl methylthio borate.

[0149] Comparative Example 9

[0150] Example 1 except that equal weight of trimethyl borate was used instead of dimethyl methylthio borate.

[0151] Comparative Example 10

[0152] Example 1 except that dimethyl methylthio borate was 2 parts by weight.

[0153] Comparative Example 11

[0154] Example 1 except that equal weight of commercially available hydroxyl acrylate was used instead of hydroxyl acrylate containing pre-polymer.

[0155] Comparative Example 12

[0156] Example 1 except that equal weight of metal phthalocyanine was used instead of metallo porphyrin.

[0157] Comparative Example 13

[0158] Example 1 except that metallo porphyrin was 0.1 parts by weight.

[0159] Comparative Example 14

[0160] Except that the long chain compatibilizer is 2 parts by weight, the rest is the same as Example 1.

[0161] Comparative Example 15

[0162] Except that 3 parts by weight of tetraethyl orthosilicate and 1.5 parts by weight of methacryloyloxypropyltrimethoxysilane are used as the hydrolysis stabilizer, the rest is the same as Example 1.

[0163] Comparative Example 16

[0164] Except that no thermal activation crosslinking agent is added and no thermal crosslinking curing treatment is performed, the rest is the same as Example 1.

[0165] Comparative Example 17

[0166] Except that no polymerization initiator is contained, the rest is the same as Example 1.

[0167] Comparative Example 18

[0168] Except that no silane pre-hydrolysis solution preparation step is performed, the rest is the same as Example 1.

[0169] Comparative Example 19

[0170] Except that the thermal crosslinking curing process uses 90°C for 30 minutes, the rest is the same as Example 1.

[0171] Test Example

[0172] The various aspects of performance and characterization methods of the OCA adhesive film in the present application are as follows:

[0173] Yellowing index (ΔE), using a color difference meter (model: Konica Minolta CM-700d), the color difference before and after the test sample is aged at 85°C / 85%RH for 1000h is measured, and the ΔE value is calculated;

[0174] Peeling strength, according to GB / T2792-2014, using a tensile testing machine (model: Instron5967), the 180° peeling strength (unit: N / 25mm) is tested at -40°C, 25°C, and 85°C, respectively;

[0175] Interfacial bonding strength, using a compression shear testing machine (model: MTSC45.304), the OCA adhesive film and a 0.3mm thick glass substrate (simulating a flexible OLED screen) are cold-pressed and bonded under a pressure of 100kPa for 30s, and the compression shear bonding strength is tested;

[0176] Water absorption, according to GB / T1034-2008, the water absorption of the test sample after being soaked at 85°C / 85%RH for 1000h is tested;

[0177] The folding life was tested by a folding tester (model: SUGA Tester F-20) under the condition of-20℃~60℃ cycle, with a folding radius R=3mm and a folding frequency of 10 times / min, and the failure (peeling or breaking) times were recorded.

[0178] The performance data of examples 1-8 are shown in table 1.

[0179] Table 1

[0180]

[0181] The performance data of comparative examples 1-9 are shown in table 2.

[0182] Table 2

[0183]

[0184] The performance data of comparative examples 10-19 are shown in table 3.

[0185] Table 3

[0186]

[0187] From the test results in table 1, it can be seen that examples 1-8 of the present application have excellent and stable comprehensive performance. The weather resistance is outstanding: the yellowing index (ΔE) is less than 1.0, and after aging at 85℃ / 85%RH for 1000h, it still maintains low yellowing, indicating that the TB-MP weathering system in the present application formula can effectively block the oxidation and hydrolysis reaction; the wide temperature range bonding adaptability is good: the peeling strength at-40℃ is higher than 17.8N / 25mm, ensuring firm bonding in low temperature environment; the peeling strength at 85℃ is reduced to 7.9-8.4N / 25mm, realizing the effect of high temperature adhesion reduction, meeting the folding screen assembly and maintenance requirements; the interface bonding and water resistance are excellent: the interface bonding strength is high, and the water absorption is less than 0.4%, benefiting from the reaction of silanol groups formed by silane pre-hydrolysis solution and hydroxyl groups of prepolymers, and anti-hydrolysis network formed by boron-oxygen bond of thioborate; the mechanical stability is strong: the folding life is more than 140000 times, benefiting from the stable gradient structure formed by light-heat synergistic curing and the enhanced matrix toughness of long-chain compatibilizer, meeting the requirements of high-end applications in the field of folding screens.

[0188] As can be seen from the test results in Table 2, compared with the comparative examples, Example 1 of the present invention shows that: due to the absence of the TB-MP weathering system, the yellowing index (ΔE) of Comparative Example 1 is significantly increased, and severe yellowing occurs after high temperature and high humidity aging. At the same time, the water absorption rate increases, and the interfacial bonding strength and peel strength decrease. This indicates that the TB-MP weathering system based on thioboronic ester, metalloporphyrin, long-chain compatibilizer and hydrolytic stabilizer in the formulation of the present invention affects all aspects of the performance of the OCA film. Comparative Example 2 uses a commercially available UV absorber to replace the TB-MP weathering system. The yellowing inhibition effect is weaker than that of Example 1, the water absorption rate increases, and the interfacial bonding strength and peel strength decrease. This indicates that the TB-MP weathering system of the present invention plays an important role in the weather resistance of the OCA film. The data of Comparative Examples 3 and 4 show that the long-chain compatibilizer has a certain influence on the weather resistance of the OCA film. Comparative Examples 5-7 are used to verify the effect of the hydrolytic stabilizer on the performance of the OCA film. Comparative Examples 8-10 are used to verify the effect of thioboronic ester on the performance of the OCA film.

[0189] As can be seen from the test results in Table 3, compared with the comparative examples, Example 1 of the present invention shows that: Comparative Example 11 used commercially available hydroxy acrylate (C12 side group without laurate acrylate copolymer) to replace the self-made prepolymer. The matrix lacked long-chain side groups, resulting in poor compatibility with weather-resistant systems (including low-polarity thioboronate esters), which led to an increase in yellowing index (ΔE) and water absorption, resulting in a decrease in weather resistance. The low-temperature peel strength may also decrease due to increased rigidity. Comparative Example 12 used metal phthalocyanine to replace... Porphyrin derivatives and metal phthalocyanines have lower free radical quenching and crosslinking catalytic efficiency than porphyrin structures, which may lead to incomplete peroxide removal and accelerated yellowing. The density of the surface crosslinked layer may also be affected, resulting in reduced peel strength and interfacial bonding strength. Comparative Examples 13-15 were used to verify the effect of different raw material weight percentages on the performance of OCA films. Comparative Example 16 showed that the thermally activated crosslinking agent and thermal crosslinking curing have a significant impact on the mechanical properties of OCA films, such as peel strength, because photothermal synergistic curing is an important condition for ensuring peel strength. Comparative Example 17, due to the lack of a polymerization initiator, may have reduced the thermal crosslinking curing effect, leading to a decrease in the mechanical properties of the OCA film. Comparative Example 18, lacking the silane pre-hydrolysis solution preparation step, directly added tetraethyl orthosilicate and aminopropyltrimethoxysilane without forming an effective anti-hydrolysis network, resulting in a significant increase in the water absorption rate of the OCA film. Comparative Example 19, using a single temperature for thermal crosslinking curing, may lead to incomplete internal crosslinking and insufficient deep crosslinking density, thus reducing the peel strength and interfacial bonding strength of the OCA film.

[0190] From the performance test results of the above examples and comparative examples, it can be seen that the selection and combination of the raw materials of the OCA glue of each embodiment of the present application and the process parameters are matched in synergy, and the prepared OCA glue film effectively realizes the synergistic improvement of the high bonding force at room temperature, the good flexibility (high peeling force) at low temperature, the moderate adhesion (convenient for rework) at high temperature, and the extremely low yellowing and water absorption performance after hygrothermal aging.

[0191] Finally, it should be noted that the content is only used to illustrate the technical solutions of the present application, and is not a limitation on the protection scope of the present application. Simple modifications or equivalent replacements of the technical solutions of the present application made by those skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A photo-thermal synergistically cured wide temperature range weatherable OCA adhesive film, characterized in that, The OCA glue includes the following components in parts by weight: The hydroxyl-containing acrylate prepolymer 100 parts, thio borate 0.8-1.2 parts, metal porphyrin 0.2-0.4 parts, long-chain compatibilizer 4-6 parts, hydrolysis stabilizer 1.5-3.1 parts, active diluent 2-4 parts, photoinitiator 1.0-2.0 parts, polymerization initiator 0.3-0.9 parts, heat-activated crosslinking agent 0.7-2.1 parts, tackifying resin 4-6 parts, solvent 40-50 parts; The hydroxyl-containing acrylate prepolymer is prepared by mixing hydroxyl acrylate monomer and lauryl acrylate monomer in a weight ratio of 7:3; The polymerization initiator is azobisisobutyronitrile, and the heat-activated crosslinking agent is benzoyl peroxide; The hydrolysis stabilizer is a compound of tetraethyl orthosilicate 1.0-2.0 parts and silane coupling agent 0.5-1.1 parts; The long-chain compatibilizer is an acrylate compound with a carbon chain length of 8-18. 2.The OCA adhesive film according to claim 1, characterized in that, A layer of the OCA glue is coated between two layers of PET release film, and is subjected to ultraviolet curing at an energy of 80-120 mJ / cm² using a 365 nm ultraviolet lamp below 40°C to form a surface crosslinking layer; Subsequently, the OCA glue is subjected to segmented heat crosslinking curing in an oven, the first stage being curing at 80-85°C for 5-8 min and the second stage being curing at 115-120°C for 10-15 min. 3.The OCA adhesive film according to claim 1, characterized in that, The thio borate is dimethyl methylthioborate or diethyl ethylthioborate. 4.The OCA adhesive film according to claim 1, characterized in that, The metal porphyrin is a porphyrin derivative with a metal ion of Co²+ or Zn²+. 5.The OCA adhesive film according to claim 1, characterized in that, The acrylate compound with a carbon chain length of 8-18 is lauryl acrylate, oleic acid acrylate or stearic acid acrylate. 6.The OCA adhesive film according to claim 1, characterized in that, The photoinitiator is 2-hydroxy-2-methylpropiophenone. 7.The OCA adhesive film according to claim 1, characterized in that, The silane coupling agent is methacryloyloxypropyl trimethoxysilane or aminopropyl trimethoxysilane; and the active diluent is one of 1,6-hexanediol diacrylate, ethylene glycol diacrylate or dipropylene glycol diacrylate. 8.The OCA adhesive film according to claim 1, characterized in that, The tackifying resin is hydrogenated rosin glyceride, and the solvent is a mixture of ethyl acetate and butanone in a weight ratio of 3:

1.

9. A method for preparing the photo-thermal synergistically cured wide temperature range weatherable OCA adhesive film according to any one of claims 1-8, characterized in that, The method comprises the following steps: S1, preparation of a hydroxyl-containing acrylate prepolymer: The hydroxyl acrylate and lauryl acrylate are added to a reaction kettle, an initiator is added, and the mixture is reacted at 60-80°C for 3-4 h under nitrogen protection to prepare the hydroxyl-containing acrylate prepolymer; S2, preparation of a silane pre-hydrolysis solution: The tetraethyl orthosilicate and the silane coupling agent are mixed, glacial acetic acid and deionized water are added, and the mixture is stirred at room temperature until transparent to prepare the silane pre-hydrolysis solution; S3, preparation of an OCA glue solution: The hydroxyl-containing acrylate prepolymer, long-chain compatibilizer, silane pre-hydrolysis solution, thio borate, metal porphyrin, active diluent, tackifying resin, solvent, photoinitiator and heat-activated crosslinking agent prepared in steps S1-S2 are added in sequence according to the formula, and high-speed dispersion is performed to obtain a uniform OCA glue solution; S4, preparation of an OCA glue film: A layer of the OCA glue solution prepared in step S3 is coated between two layers of PET release film, and is subjected to photo-thermal curing in sequence.

10. The use of an OCA adhesive film in the preparation of a folding screen, characterized in that, The OCA adhesive film is a photo-thermal synergistically cured wide-temperature-range weather-resistant OCA adhesive film according to any one of claims 1-8. The OCA adhesive film is a photo-thermal synergistically cured wide-temperature-range weather-resistant OCA adhesive film according to any one of claims 1-8.

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